Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/09/14
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
230 PM MST WED MAY 7 2014
.UPDATE...UPDATED AVIATION DISCUSSION...
&&
.SYNOPSIS...
PACIFIC LOW PRESSURE WILL CONTINUE TO MOVE THROUGH THE REGION
TODAY...BRINGING COOLER TEMPERATURES AND ANOTHER ROUND OF AFTERNOON
BREEZES. WINDS ARE NOT EXPECTED AS STRONG AS THOSE OBSERVED
TUESDAY...WITH ONLY ISOLATED GUSTS POSSIBLE IN THE AFTERNOON.
FORECAST DAYTIME HIGHS WILL FALL WELL BELOW NORMAL AT MANY DESERT
LOCATIONS THROUGH THURSDAY. DRY AND WARMER WEATHER IS ON TAP FRIDAY
AND THROUGH THE WEEKEND AS HIGH TEMPERATURES CLIMB BACK INTO THE 90S
ACROSS THE LOWER DESERTS.
&&
.DISCUSSION...
COLD FRONT FROM YESTERDAY IS NOW IN NEW MEXICO BUT A FAIRLY TIGHT
SURFACE PRESSURE GRADIENT REMAINS ACROSS THE FORECAST AREA AND THUS
SOME BREEZINESS CAN BE EXPECTED AS THE DAY PROGRESSES BUT MUCH LESS
WIND THAN YESTERDAY. MEANWHILE THE UPPER REMAINS OVER THE INTERIOR
WEST WITH 12Z PLOT DATA INDICATING THE NORTH-SOUTH ORIENTED AXIS
OVER WESTERN UTAH AND WESTERN ARIZONA WITH THE CENTER OF THE UPPER
CIRCULATION OVER WESTERN UTAH. SATELLITE IMAGERY SHOWS A FAIR AMOUNT
OF MID CLOUDS OVER NORTHERN AND EASTERN ARIZONA. SATELLITE IMAGERY
ALSO SHOWS A VORT LOBE ROUNDING THE BOTTOM OF THE TROUGH OVER
SOUTHERN ARIZONA. UVV ASSOCIATED WITH THIS FEATURE WILL BE SHIFTING
TO NEW MEXICO BY AFTERNOON. COLD AIR ALOFT WILL ALLOW FOR SOME
MEAGER CAPE...MAINLY OVER NORTHERN ARIZONA...BUT BOTH 12Z NAM AND
GFS HAVE MORE CIN THAN CAPE. A TRAILING SHORT WAVE TONIGHT WILL HAVE
EVEN LESS LIFT THAN THE ONE FOR TODAY. SO...SLIGHT CHANCES OF PRECIP
OVER SOME HIGHER TERRAIN PORTIONS OF THE FORECAST AREA WILL BE ABOUT
THE MOST WE CAN MUSTER. OTHERWISE...JUST SOME MID CLOUDS.
OTHERWISE...FORECAST TEMPS ON TRACK FOR A NICE COOL DAY TODAY.
&&
.PREVIOUS DISCUSSION ISSUED 206 AM...
SHARPLY DEFINED PACIFIC TROUGH CONTINUES TO SLOWLY CIRCULATE INTO THE
REGION...WITH THE TROUGH AXIS NEARING THE COLORADO RIVER VALLEY THIS
MORNING. NEARLY CLEAR SKIES LEFT OVER THE WHOLE CWA IN THE WAKE OF
THE VIGOROUS COLD FRONT PASSAGE TUESDAY. SOME EARLY
EVENING/OVERNIGHT LIGHT SHOWER ACTIVITY CONTINUES NEAR THE COLD CORE
OF THE TROUGH OVER SOUTHERN NEVADA AND TO A LESSER EXTENT SOUTHEAST
CALIFORNIA...WITH MOST SITES ONLY REPORTING OVERCAST SKIES AND A
HUNDREDTH OR TWO OF PRECIP ACROSS THE SOUTHERN NEVADA STATIONS.
WATER VAPOR LOOP AND POTENTIAL VORTICITY MODEL OVERLAY PLOT A POCKET
OF ENHANCED VORTICITY/SPIN COMING AROUND THE TROUGH BOTTOM AND ACROSS
THE CA/INTL BORDER THIS MORNING. THIS VORT LOBE IS PROGGED THROUGH
CENTRAL ARIZONA BY MIDDAY BEFORE QUICKLY DIFFUSING AND CLEARING EAST
THIS EVENING. MOISTURE TRANSPORT AND PWATS NOT OVERLY FAVORABLE FOR
SIGNIFICANT SHOWER ACTIVITY...WITH THE BEST PWATS OF NEAR HALF AN
INCH OVER THE COLORADO RIVER VALLEY BY MIDDAY AND NOT EXTENDING MUCH
FURTHER EAST. EVENING RUNS OF THE HI-RES HRRR AND ARW SHOW ANY SHOWER
ACTIVITY DEVELOPING ACROSS NORTHERN ARIZONA THROUGH THE DAY AS THE
TROUGH CONTINUES THROUGH THE AREA...WITH ONLY VERY SPOTTY DEVELOPMENT
SKIRTING ACROSS THE NORTHERN PORTIONS OF MARICOPA AND GILA COUNTIES
THROUGH THE AFTERNOON. SLIGHT CHANCE POPS WERE KEPT ACROSS THE HIGHER
TERRAIN TO THE NORTH/EAST OF PHOENIX...WITH MENTION DROPPING OFF
AFTER 08/03Z (8PM LOCAL) ONCE HEATING SUPPORT IS LOST WITH SUNSET.
SIGNIFICANT COOLING OBSERVED BEHIND THE COLD FRONT...AS MUCH AS 10
DEGREES FROM THE SFC UP THROUGH 400MB VIA THE KVEF 00Z RAOB AND 6-8
DEGREES FROM KFGZ...WILL KEEP TEMPERATURES TODAY AND THURSDAY WELL
BELOW SEASONAL NORMALS. LOOK FOR MID TO UPPER 70S ACROSS THE SOUTH-
CENTRAL ARIZONA DESERTS WITH SLIGHTLY WARMER VALUES ACROSS THE
WESTERN FORECAST AREA IN THE LOW 80S WEDNESDAY AND WIDESPREAD 80S
AREAWIDE FOR THURSDAY UNDER MOSTLY CLEAR SKIES.
BY FRIDAY...TROUGHING WILL HAVE MOSTLY CLEARED THE AREA WITH DRY WEST
TO NORTHWESTERLY FLOW OVERTAKING THE REGION. TEMPERATURES WILL
REBOUND BACK TOWARDS EARLY MAY NORMALS WITH LOW TO MID 90 DEGREE
READINGS IN STORE FOR THE WEEKEND. ANOTHER LOW PRESSURE SYSTEM WILL
DROP OUT OF THE PACIFIC NORTHWEST LATE SATURDAY INTO SUNDAY...BUT
CURRENT THINKING FROM WPC AND THE BETTER PERFORMING
OPERATIONAL/ENSEMBLE RUNS OF THE ECMWF KEEP THE BULK OF THE ENERGY
AND ANY PRECIPITATION WELL TO OUR NORTH THROUGH MUCH OF THE GREAT
BASIN STATES AND ONLY SKIRTING THE FAR NORTHERN PORTIONS OF ARIZONA.
COULD SEE SOME ENHANCED BREEZINESS AS SOME GRADIENT TIGHTENING IS
FORECAST...BUT VERY STRONG WINDS ARE NOT EXPECTED AT THIS TIME. 500MB
HEIGHTS AND THICKNESSES WILL SEE SOME DECREASE...WHICH WILL KEEP
DAYTIME TEMPERATURES FROM TAKING OFF TOO RAPIDLY FOR EARLY NEXT WEEK
AND STAYING CLOSER TOWARDS NORMAL READINGS IN THE LOW TO MID 90S.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
WINDS CONTINUE TO REMAIN BREEZY TO GUSTY INTO THE LATE AFTERNOON AND
EVENING HOURS...GUSTS TO 25 KTS OR SO ARE POSSIBLE. PREDOMINANTLY
FROM THE WEST-SOUTHWEST DIRECTION AND SHOULD SWING TO AN EASTERLY
HEADING BY 12Z THURSDAY MORNING. EXPECT LOWER CLOUD DECKS...8-10KT
FEET TO LINGER THROUGH THE EVENING HOURS. LINGERING DUST/HAZE SHOULD
IMPROVE AS MIXING CONTINUES...BUT MAY HANG AROUND THROUGH THE
EVENING. VISIBILITIES SHOULD NOT BE IMPACTED BY HAZE.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
ELEVATED WINDS ACROSS SOUTHEAST CALIFORNIA TAF SITES AS WEATHER
SYSTEM DEPARTS TO THE EAST WILL TAPER OFF AFTER SUNSET. HOLDING
WESTERLY DIRECTION...WINDS SHOULD REMAIN BREEZY WITH GUSTS BELOW 25
KTS. MOSTLY CLEAR SKIES WITH SOME CU DECKS 8-10 KT FT POSSIBLE
ESPECIALLY NEAR KBLH.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
DRY NORTHWEST FLOW ALOFT WILL SETTLE IN ACROSS THE AREA INTO THE
WEEKEND...ALLOWING FOR A GRADUAL WARMING TREND WITH DESERT HIGHS
CLIMBING INTO THE MID 90S BY SATURDAY. HUMIDITIES WILL BE ON THE LOW
SIDE...RANGING FROM SINGLE DIGITS TO THE LOW TEENS EACH DAY. A
WEATHER DISTURBANCE PASSING BY TO THE NORTH OVER THE WEEKEND WILL
LEAD TO LOCALLY BREEZY CONDITIONS DURING THE AFTERNOON AND EVENING
HOURS SATURDAY AND SUNDAY. EVEN HIGHER PRESSURE ALOFT WILL THEN
BUILD BACK INTO THE DESERT SOUTHWEST EARLY NEXT WEEK FOR LIGHTER
WIND...ALONG WITH WARMER AND DRIER CONDITIONS. BY NEXT TUESDAY
EXPECT THE WARMER DESERTS TO EXCEED 100 DEGREES...AND MINIMUM
HUMIDITIES TO FALL WELL BELOW 10 PERCENT OVER THE DRIER LOWER DESERT.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
PREVIOUS DISCUSSION...NOLTE
AVIATION...CDEWEY
FIRE WEATHER...CB
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
955 AM MST WED MAY 7 2014
.SYNOPSIS...
PACIFIC LOW PRESSURE WILL CONTINUE TO MOVE THROUGH THE REGION
TODAY...BRINGING COOLER TEMPERATURES AND ANOTHER ROUND OF AFTERNOON
BREEZES. WINDS ARE NOT EXPECTED AS STRONG AS THOSE OBSERVED
TUESDAY...WITH ONLY ISOLATED GUSTS POSSIBLE IN THE AFTERNOON.
FORECAST DAYTIME HIGHS WILL FALL WELL BELOW NORMAL AT MANY DESERT
LOCATIONS THROUGH THURSDAY. DRY AND WARMER WEATHER IS ON TAP FRIDAY
AND THROUGH THE WEEKEND AS HIGH TEMPERATURES CLIMB BACK INTO THE 90S
ACROSS THE LOWER DESERTS.
&&
.DISCUSSION...
COLD FRONT FROM YESTERDAY IS NOW IN NEW MEXICO BUT A FAIRLY TIGHT
SURFACE PRESSURE GRADIENT REMAINS ACROSS THE FORECAST AREA AND THUS
SOME BREEZINESS CAN BE EXPECTED AS THE DAY PROGRESSES BUT MUCH LESS
WIND THAN YESTERDAY. MEANWHILE THE UPPER REMAINS OVER THE INTERIOR
WEST WITH 12Z PLOT DATA INDICATING THE NORTH-SOUTH ORIENTED AXIS
OVER WESTERN UTAH AND WESTERN ARIZONA WITH THE CENTER OF THE UPPER
CIRCULATION OVER WESTERN UTAH. SATELLITE IMAGERY SHOWS A FAIR AMOUNT
OF MID CLOUDS OVER NORTHERN AND EASTERN ARIZONA. SATELLITE IMAGERY
ALSO SHOWS A VORT LOBE ROUNDING THE BOTTOM OF THE TROUGH OVER
SOUTHERN ARIZONA. UVV ASSOCIATED WITH THIS FEATURE WILL BE SHIFTING
TO NEW MEXICO BY AFTERNOON. COLD AIR ALOFT WILL ALLOW FOR SOME
MEAGER CAPE...MAINLY OVER NORTHERN ARIZONA...BUT BOTH 12Z NAM AND
GFS HAVE MORE CIN THAN CAPE. A TRAILING SHORT WAVE TONIGHT WILL HAVE
EVEN LESS LIFT THAN THE ONE FOR TODAY. SO...SLIGHT CHANCES OF PRECIP
OVER SOME HIGHER TERRAIN PORTIONS OF THE FORECAST AREA WILL BE ABOUT
THE MOST WE CAN MUSTER. OTHERWISE...JUST SOME MID CLOUDS.
OTHERWISE...FORECAST TEMPS ON TRACK FOR A NICE COOL DAY TODAY.
&&
.PREVIOUS DISCUSSION ISSUED 206 AM...
SHARPLY DEFINED PACIFIC TROUGH CONTINUES TO SLOWLY CIRCULATE INTO THE
REGION...WITH THE TROUGH AXIS NEARING THE COLORADO RIVER VALLEY THIS
MORNING. NEARLY CLEAR SKIES LEFT OVER THE WHOLE CWA IN THE WAKE OF
THE VIGOROUS COLD FRONT PASSAGE TUESDAY. SOME EARLY
EVENING/OVERNIGHT LIGHT SHOWER ACTIVITY CONTINUES NEAR THE COLD CORE
OF THE TROUGH OVER SOUTHERN NEVADA AND TO A LESSER EXTENT SOUTHEAST
CALIFORNIA...WITH MOST SITES ONLY REPORTING OVERCAST SKIES AND A
HUNDREDTH OR TWO OF PRECIP ACROSS THE SOUTHERN NEVADA STATIONS.
WATER VAPOR LOOP AND POTENTIAL VORTICITY MODEL OVERLAY PLOT A POCKET
OF ENHANCED VORTICITY/SPIN COMING AROUND THE TROUGH BOTTOM AND ACROSS
THE CA/INTL BORDER THIS MORNING. THIS VORT LOBE IS PROGGED THROUGH
CENTRAL ARIZONA BY MIDDAY BEFORE QUICKLY DIFFUSING AND CLEARING EAST
THIS EVENING. MOISTURE TRANSPORT AND PWATS NOT OVERLY FAVORABLE FOR
SIGNIFICANT SHOWER ACTIVITY...WITH THE BEST PWATS OF NEAR HALF AN
INCH OVER THE COLORADO RIVER VALLEY BY MIDDAY AND NOT EXTENDING MUCH
FURTHER EAST. EVENING RUNS OF THE HI-RES HRRR AND ARW SHOW ANY SHOWER
ACTIVITY DEVELOPING ACROSS NORTHERN ARIZONA THROUGH THE DAY AS THE
TROUGH CONTINUES THROUGH THE AREA...WITH ONLY VERY SPOTTY DEVELOPMENT
SKIRTING ACROSS THE NORTHERN PORTIONS OF MARICOPA AND GILA COUNTIES
THROUGH THE AFTERNOON. SLIGHT CHANCE POPS WERE KEPT ACROSS THE HIGHER
TERRAIN TO THE NORTH/EAST OF PHOENIX...WITH MENTION DROPPING OFF
AFTER 08/03Z (8PM LOCAL) ONCE HEATING SUPPORT IS LOST WITH SUNSET.
SIGNIFICANT COOLING OBSERVED BEHIND THE COLD FRONT...AS MUCH AS 10
DEGREES FROM THE SFC UP THROUGH 400MB VIA THE KVEF 00Z RAOB AND 6-8
DEGREES FROM KFGZ...WILL KEEP TEMPERATURES TODAY AND THURSDAY WELL
BELOW SEASONAL NORMALS. LOOK FOR MID TO UPPER 70S ACROSS THE SOUTH-
CENTRAL ARIZONA DESERTS WITH SLIGHTLY WARMER VALUES ACROSS THE
WESTERN FORECAST AREA IN THE LOW 80S WEDNESDAY AND WIDESPREAD 80S
AREAWIDE FOR THURSDAY UNDER MOSTLY CLEAR SKIES.
BY FRIDAY...TROUGHING WILL HAVE MOSTLY CLEARED THE AREA WITH DRY WEST
TO NORTHWESTERLY FLOW OVERTAKING THE REGION. TEMPERATURES WILL
REBOUND BACK TOWARDS EARLY MAY NORMALS WITH LOW TO MID 90 DEGREE
READINGS IN STORE FOR THE WEEKEND. ANOTHER LOW PRESSURE SYSTEM WILL
DROP OUT OF THE PACIFIC NORTHWEST LATE SATURDAY INTO SUNDAY...BUT
CURRENT THINKING FROM WPC AND THE BETTER PERFORMING
OPERATIONAL/ENSEMBLE RUNS OF THE ECMWF KEEP THE BULK OF THE ENERGY
AND ANY PRECIPITATION WELL TO OUR NORTH THROUGH MUCH OF THE GREAT
BASIN STATES AND ONLY SKIRTING THE FAR NORTHERN PORTIONS OF ARIZONA.
COULD SEE SOME ENHANCED BREEZINESS AS SOME GRADIENT TIGHTENING IS
FORECAST...BUT VERY STRONG WINDS ARE NOT EXPECTED AT THIS TIME. 500MB
HEIGHTS AND THICKNESSES WILL SEE SOME DECREASE...WHICH WILL KEEP
DAYTIME TEMPERATURES FROM TAKING OFF TOO RAPIDLY FOR EARLY NEXT WEEK
AND STAYING CLOSER TOWARDS NORMAL READINGS IN THE LOW TO MID 90S.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
UPPER LOW WILL CONTINUE TO MOVE EAST ACROSS THE AREA TODAY INTO
TONIGHT. EXPECT SCT-BKN CU/SC DECKS TO DEVELOP ACROSS THE CENTRAL
DESERTS LATER THIS MORNING...CONTINUING INTO THE AFTERNOON HOURS
WITH BASES GENLY 8-10K FEET. NO PRECIP EXPECTED AT THE TAF
SITES...ONLY ACROSS HIGHER ELEVATIONS NORTH/EAST OF PHOENIX. WINDS
TO STAY MOSTLY OUT OF THE WEST THIS MORNING...INCREASING AND
BECOMING LOCALLY GUSTY BY LATE MORNING OR EARLY AFTN. MAY SEE A FEW
GUSTS TO 25KT OR SO BY AFTN. WINDS TO TAPER OFF AFTER SUNSET...SKIES
TO BECOME MOSTLY CLEAR.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
UPPER LOW WILL CONTINUE TO MOVE EAST ACROSS THE AREA
TODAY...BRINGING LOCALLY GUSTY WEST WINDS TO THE TAF SITES ALONG
WITH FEW-SCT CUMULUS DECKS. THERE MAY BE SOME CIGS AROUND 8-10K THIS
MORNING...WITH CLOUDS THINNING BY AFTERNOON AS SUBSIDENCE MOVES INTO
AREA BEHIND A COLD FRONT. EXPECT SOME WIND GUSTS TO AT LEAST 25KT AT
TIMES AT KIPL THIS AFTERNOON...A BIT LESS WIND AT KBLH. WINDS TO
TAPER OFF AFTER SUNSET FOLLOWING LACK OF MIXING...AND SKIES TO
BECOME GENLY CLEAR.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
DRY NORTHWEST FLOW ALOFT WILL SETTLE IN ACROSS THE AREA FRIDAY INTO
THE WEEKEND...ALLOWING FOR A GRADUAL WARMING TREND WITH DESERT HIGHS
CLIMBING INTO THE MID 90S BY SATURDAY. HUMIDITIES WILL BE ON THE LOW
SIDE...RANGING FROM SINGLE DIGITS TO THE LOW TEENS EACH DAY. A
WEATHER DISTURBANCE PASSING BY TO THE NORTH OVER THE WEEKEND WILL
LEAD TO LOCALLY BREEZY CONDITIONS DURING THE AFTERNOON AND EVENING
HOURS SATURDAY AND SUNDAY. EVEN HIGHER PRESSURE ALOFT WILL THEN
BUILD BACK INTO THE DESERT SOUTHWEST EARLY NEXT WEEK FOR LIGHTER
WIND...ALONG WITH WARMER AND DRIER CONDITIONS. BY NEXT TUESDAY
EXPECT THE WARMER DESERTS TO EXCEED 100 DEGREES...AND MINIMUM
HUMIDITIES TO FALL WELL BELOW 10 PERCENT OVER THE DRIER LOWER DESERT.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
PREVIOUS DISCUSSION...NOLTE
AVIATION...CB
FIRE WEATHER...CB
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
500 AM MST WED MAY 7 2014
.UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS.
&&
.SYNOPSIS...
PACIFIC LOW PRESSURE WILL CONTINUE TO MOVE THROUGH THE REGION
TODAY...BRINGING COOLER TEMPERATURES AND ANOTHER ROUND OF AFTERNOON
BREEZES. WINDS ARE NOT EXPECTED AS STRONG AS THOSE OBSERVED
TUESDAY...WITH ONLY ISOLATED GUSTS POSSIBLE IN THE AFTERNOON.
FORECAST DAYTIME HIGHS WILL FALL WELL BELOW NORMAL AT MANY DESERT
LOCATIONS THROUGH THURSDAY. DRY AND WARMER WEATHER IS ON TAP FRIDAY
AND THROUGH THE WEEKEND AS HIGH TEMPERATURES CLIMB BACK INTO THE 90S
ACROSS THE LOWER DESERTS.
&&
.DISCUSSION...
SHARPLY DEFINED PACIFIC TROUGH CONTINUES TO SLOWLY CIRCULATE INTO THE
REGION...WITH THE TROUGH AXIS NEARING THE COLORADO RIVER VALLEY THIS
MORNING. NEARLY CLEAR SKIES LEFT OVER THE WHOLE CWA IN THE WAKE OF
THE VIGOROUS COLD FRONT PASSAGE TUESDAY. SOME EARLY
EVENING/OVERNIGHT LIGHT SHOWER ACTIVITY CONTINUES NEAR THE COLD CORE
OF THE TROUGH OVER SOUTHERN NEVADA AND TO A LESSER EXTENT SOUTHEAST
CALIFORNIA...WITH MOST SITES ONLY REPORTING OVERCAST SKIES AND A
HUNDREDTH OR TWO OF PRECIP ACROSS THE SOUTHERN NEVADA STATIONS.
WATER VAPOR LOOP AND POTENTIAL VORTICITY MODEL OVERLAY PLOT A POCKET
OF ENHANCED VORTICITY/SPIN COMING AROUND THE TROUGH BOTTOM AND ACROSS
THE CA/INTL BORDER THIS MORNING. THIS VORT LOBE IS PROGGED THROUGH
CENTRAL ARIZONA BY MIDDAY BEFORE QUICKLY DIFFUSING AND CLEARING EAST
THIS EVENING. MOISTURE TRANSPORT AND PWATS NOT OVERLY FAVORABLE FOR
SIGNIFICANT SHOWER ACTIVITY...WITH THE BEST PWATS OF NEAR HALF AN
INCH OVER THE COLORADO RIVER VALLEY BY MIDDAY AND NOT EXTENDING MUCH
FURTHER EAST. EVENING RUNS OF THE HI-RES HRRR AND ARW SHOW ANY SHOWER
ACTIVITY DEVELOPING ACROSS NORTHERN ARIZONA THROUGH THE DAY AS THE
TROUGH CONTINUES THROUGH THE AREA...WITH ONLY VERY SPOTTY DEVELOPMENT
SKIRTING ACROSS THE NORTHERN PORTIONS OF MARICOPA AND GILA COUNTIES
THROUGH THE AFTERNOON. SLIGHT CHANCE POPS WERE KEPT ACROSS THE HIGHER
TERRAIN TO THE NORTH/EAST OF PHOENIX...WITH MENTION DROPPING OFF
AFTER 08/03Z (8PM LOCAL) ONCE HEATING SUPPORT IS LOST WITH SUNSET.
SIGNIFICANT COOLING OBSERVED BEHIND THE COLD FRONT...AS MUCH AS 10
DEGREES FROM THE SFC UP THROUGH 400MB VIA THE KVEF 00Z RAOB AND 6-8
DEGREES FROM KFGZ...WILL KEEP TEMPERATURES TODAY AND THURSDAY WELL
BELOW SEASONAL NORMALS. LOOK FOR MID TO UPPER 70S ACROSS THE SOUTH-
CENTRAL ARIZONA DESERTS WITH SLIGHTLY WARMER VALUES ACROSS THE
WESTERN FORECAST AREA IN THE LOW 80S WEDNESDAY AND WIDESPREAD 80S
AREAWIDE FOR THURSDAY UNDER MOSTLY CLEAR SKIES.
BY FRIDAY...TROUGHING WILL HAVE MOSTLY CLEARED THE AREA WITH DRY WEST
TO NORTHWESTERLY FLOW OVERTAKING THE REGION. TEMPERATURES WILL
REBOUND BACK TOWARDS EARLY MAY NORMALS WITH LOW TO MID 90 DEGREE
READINGS IN STORE FOR THE WEEKEND. ANOTHER LOW PRESSURE SYSTEM WILL
DROP OUT OF THE PACIFIC NORTHWEST LATE SATURDAY INTO SUNDAY...BUT
CURRENT THINKING FROM WPC AND THE BETTER PERFORMING
OPERATIONAL/ENSEMBLE RUNS OF THE ECMWF KEEP THE BULK OF THE ENERGY
AND ANY PRECIPITATION WELL TO OUR NORTH THROUGH MUCH OF THE GREAT
BASIN STATES AND ONLY SKIRTING THE FAR NORTHERN PORTIONS OF ARIZONA.
COULD SEE SOME ENHANCED BREEZINESS AS SOME GRADIENT TIGHTENING IS
FORECAST...BUT VERY STRONG WINDS ARE NOT EXPECTED AT THIS TIME. 500MB
HEIGHTS AND THICKNESSES WILL SEE SOME DECREASE...WHICH WILL KEEP
DAYTIME TEMPERATURES FROM TAKING OFF TOO RAPIDLY FOR EARLY NEXT WEEK
AND STAYING CLOSER TOWARDS NORMAL READINGS IN THE LOW TO MID 90S.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
UPPER LOW WILL CONTINUE TO MOVE EAST ACROSS THE AREA TODAY INTO
TONIGHT. EXPECT SCT-BKN CU/SC DECKS TO DEVELOP ACROSS THE CENTRAL
DESERTS LATER THIS MORNING...CONTINUING INTO THE AFTERNOON HOURS
WITH BASES GENLY 8-10K FEET. NO PRECIP EXPECTED AT THE TAF
SITES...ONLY ACROSS HIGHER ELEVATIONS NORTH/EAST OF PHOENIX. WINDS
TO STAY MOSTLY OUT OF THE WEST THIS MORNING...INCREASING AND
BECOMING LOCALLY GUSTY BY LATE MORNING OR EARLY AFTN. MAY SEE A FEW
GUSTS TO 25KT OR SO BY AFTN. WINDS TO TAPER OFF AFTER SUNSET...SKIES
TO BECOME MOSTLY CLEAR.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
UPPER LOW WILL CONTINUE TO MOVE EAST ACROSS THE AREA
TODAY...BRINGING LOCALLY GUSTY WEST WINDS TO THE TAF SITES ALONG
WITH FEW-SCT CUMULUS DECKS. THERE MAY BE SOME CIGS AROUND 8-10K THIS
MORNING...WITH CLOUDS THINNING BY AFTERNOON AS SUBSIDENCE MOVES INTO
AREA BEHIND A COLD FRONT. EXPECT SOME WIND GUSTS TO AT LEAST 25KT AT
TIMES AT KIPL THIS AFTERNOON...A BIT LESS WIND AT KBLH. WINDS TO
TAPER OFF AFTER SUNSET FOLLOWING LACK OF MIXING...AND SKIES TO
BECOME GENLY CLEAR.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
DRY NORTHWEST FLOW ALOFT WILL SETTLE IN ACROSS THE AREA FRIDAY INTO
THE WEEKEND...ALLOWING FOR A GRADUAL WARMING TREND WITH DESERT HIGHS
CLIMBING INTO THE MID 90S BY SATURDAY. HUMIDITIES WILL BE ON THE LOW
SIDE...RANGING FROM SINGLE DIGITS TO THE LOW TEENS EACH DAY. A
WEATHER DISTURBANCE PASSING BY TO THE NORTH OVER THE WEEKEND WILL
LEAD TO LOCALLY BREEZY CONDITIONS DURING THE AFTERNOON AND EVENING
HOURS SATURDAY AND SUNDAY. EVEN HIGHER PRESSURE ALOFT WILL THEN
BUILD BACK INTO THE DESERT SOUTHWEST EARLY NEXT WEEK FOR LIGHTER
WIND...ALONG WITH WARMER AND DRIER CONDITIONS. BY NEXT TUESDAY
EXPECT THE WARMER DESERTS TO EXCEED 100 DEGREES...AND MINIMUM
HUMIDITIES TO FALL WELL BELOW 10 PERCENT OVER THE DRIER LOWER DESERT.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...NOLTE
AVIATION....CB
FIRE WEATHER...CB
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
206 AM MST WED MAY 7 2014
.SYNOPSIS...
PACIFIC LOW PRESSURE WILL CONTINUE TO MOVE THROUGH THE REGION
TODAY...BRINGING COOLER TEMPERATURES AND ANOTHER ROUND OF AFTERNOON
BREEZES. WINDS ARE NOT EXPECTED AS STRONG AS THOSE OBSERVED
TUESDAY...WITH ONLY ISOLATED GUSTS POSSIBLE IN THE AFTERNOON.
FORECAST DAYTIME HIGHS WILL FALL WELL BELOW NORMAL AT MANY DESERT
LOCATIONS THROUGH THURSDAY. DRY AND WARMER WEATHER IS ON TAP FRIDAY
AND THROUGH THE WEEKEND AS HIGH TEMPERATURES CLIMB BACK INTO THE 90S
ACROSS THE LOWER DESERTS.
&&
.DISCUSSION...
SHARPLY DEFINED PACIFIC TROUGH CONTINUES TO SLOWLY CIRCULATE INTO THE
REGION...WITH THE TROUGH AXIS NEARING THE COLORADO RIVER VALLEY THIS
MORNING. NEARLY CLEAR SKIES LEFT OVER THE WHOLE CWA IN THE WAKE OF
THE VIGOROUS COLD FRONT PASSAGE TUESDAY. SOME EARLY
EVENING/OVERNIGHT LIGHT SHOWER ACTIVITY CONTINUES NEAR THE COLD CORE
OF THE TROUGH OVER SOUTHERN NEVADA AND TO A LESSER EXTENT SOUTHEAST
CALIFORNIA...WITH MOST SITES ONLY REPORTING OVERCAST SKIES AND A
HUNDREDTH OR TWO OF PRECIP ACROSS THE SOUTHERN NEVADA STATIONS.
WATER VAPOR LOOP AND POTENTIAL VORTICITY MODEL OVERLAY PLOT A POCKET
OF ENHANCED VORTICITY/SPIN COMING AROUND THE TROUGH BOTTOM AND ACROSS
THE CA/INTL BORDER THIS MORNING. THIS VORT LOBE IS PROGGED THROUGH
CENTRAL ARIZONA BY MIDDAY BEFORE QUICKLY DIFFUSING AND CLEARING EAST
THIS EVENING. MOISTURE TRANSPORT AND PWATS NOT OVERLY FAVORABLE FOR
SIGNIFICANT SHOWER ACTIVITY...WITH THE BEST PWATS OF NEAR HALF AN
INCH OVER THE COLORADO RIVER VALLEY BY MIDDAY AND NOT EXTENDING MUCH
FURTHER EAST. EVENING RUNS OF THE HI-RES HRRR AND ARW SHOW ANY SHOWER
ACTIVITY DEVELOPING ACROSS NORTHERN ARIZONA THROUGH THE DAY AS THE
TROUGH CONTINUES THROUGH THE AREA...WITH ONLY VERY SPOTTY DEVELOPMENT
SKIRTING ACROSS THE NORTHERN PORTIONS OF MARICOPA AND GILA COUNTIES
THROUGH THE AFTERNOON. SLIGHT CHANCE POPS WERE KEPT ACROSS THE HIGHER
TERRAIN TO THE NORTH/EAST OF PHOENIX...WITH MENTION DROPPING OFF
AFTER 08/03Z (8PM LOCAL) ONCE HEATING SUPPORT IS LOST WITH SUNSET.
SIGNIFICANT COOLING OBSERVED BEHIND THE COLD FRONT...AS MUCH AS 10
DEGREES FROM THE SFC UP THROUGH 400MB VIA THE KVEF 00Z RAOB AND 6-8
DEGREES FROM KFGZ...WILL KEEP TEMPERATURES TODAY AND THURSDAY WELL
BELOW SEASONAL NORMALS. LOOK FOR MID TO UPPER 70S ACROSS THE SOUTH-
CENTRAL ARIZONA DESERTS WITH SLIGHTLY WARMER VALUES ACROSS THE
WESTERN FORECAST AREA IN THE LOW 80S WEDNESDAY AND WIDESPREAD 80S
AREAWIDE FOR THURSDAY UNDER MOSTLY CLEAR SKIES.
BY FRIDAY...TROUGHING WILL HAVE MOSTLY CLEARED THE AREA WITH DRY WEST
TO NORTHWESTERLY FLOW OVERTAKING THE REGION. TEMPERATURES WILL
REBOUND BACK TOWARDS EARLY MAY NORMALS WITH LOW TO MID 90 DEGREE
READINGS IN STORE FOR THE WEEKEND. ANOTHER LOW PRESSURE SYSTEM WILL
DROP OUT OF THE PACIFIC NORTHWEST LATE SATURDAY INTO SUNDAY...BUT
CURRENT THINKING FROM WPC AND THE BETTER PERFORMING
OPERATIONAL/ENSEMBLE RUNS OF THE ECMWF KEEP THE BULK OF THE ENERGY
AND ANY PRECIPITATION WELL TO OUR NORTH THROUGH MUCH OF THE GREAT
BASIN STATES AND ONLY SKIRTING THE FAR NORTHERN PORTIONS OF ARIZONA.
COULD SEE SOME ENHANCED BREEZINESS AS SOME GRADIENT TIGHTENING IS
FORECAST...BUT VERY STRONG WINDS ARE NOT EXPECTED AT THIS TIME. 500MB
HEIGHTS AND THICKNESSES WILL SEE SOME DECREASE...WHICH WILL KEEP
DAYTIME TEMPERATURES FROM TAKING OFF TOO RAPIDLY FOR EARLY NEXT WEEK
AND STAYING CLOSER TOWARDS NORMAL READINGS IN THE LOW TO MID 90S.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
CIRRUS DECK WILL CONTINUE TO MOVE EAST...AS UPPER LEVEL LOW MOVES
OVER THE REGION TONIGHT. MID LEVEL CLOUD DECKS MAY FORM OVERNIGHT
WITH SCT CU AROUND 9000FT POSSIBLE OVER THE AREA. GUSTY WINDS WILL
CONTINUE TO DECREASE OVERNIGHT...SETTLING IN AROUND 10KT...AND
MAINTAINING A WEST-SOUTHWEST COMPONENT DURING THE TAF PERIOD.
SUSPENDED DUST MAY ALSO CREATE SOME AREAS OF HAZE AND SLANT-WISE
VISIBILITY ISSUES AT SOME AIRFIELDS WEDNESDAY MORNING. WINDS WILL
INCREASE AGAIN WEDNESDAY AFTERNOON...WITH GUSTS UP TO 20 MPH COMMON
AFTER 19Z.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
GUSTY SOUTHWEST TO WEST WINDS...UP TO 30 KTS...WILL PERSIST ACROSS
SOUTHEAST CALIFORNIA THROUGH AT LEAST 06Z. WINDS TAPER OFF AT KBLH
BUT WILL REMAIN ELEVATED AT KIPL UNTIL AROUND 12Z WEDNESDAY MORNING.
OTHER THAN A FEW-SCT MID LEVEL CU AS UPPER LEVEL LOW MOVES OVER THE
REGION TONIGHT...EXPECT MOSTLY CLEAR SKIES OVERNIGHT. WINDS WILL
INCREASE AGAIN WEDNESDAY AFTERNOON...WITH GUSTS UP TO 25 MPH COMMON
AFTER 19Z.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
HIGH PRESSURE AND DRY NORTHWESTERLY FLOW ALOFT WILL BUILD EASTWARD
INTO THE DESERT SOUTHWEST...AND BRING DRY CONDITIONS AND A SLOW
WARMING TREND TO THE REGION THROUGH THE FORECAST PERIOD. HIGHS IN
THE 80S ON THURSDAY WILL GRADUALLY WARM INTO THE MID TO UPPER 90S BY
SUNDAY AND MONDAY. MINIMUM RH VALUES IN THE TEENS ON THURSDAY WILL
LOWER BACK INTO THE SINGLE DIGITS OVER MUCH OF THE LOWER DESERTS BY
THE WEEKEND. WINDS ARE EXPECTED TO REMAIN MOSTLY ON THE LIGHT SIDE
EACH DAY...WITH JUST SOME TYPICAL AFTERNOON GUSTINESS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...NOLTE
AVIATION....MEYERS
FIRE WEATHER...PERCHA/CB
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
510 PM PDT THU MAY 8 2014
.SYNOPSIS...A WEAK PACIFIC STORM SYSTEM WILL BRING A CHANCE OF LIGHT
RAIN TO THE SAN FRANCISCO BAY AREA AND PORTIONS OF THE CENTRAL
COAST THROUGH TONIGHT. DRY CONDITIONS WILL RETURN THIS WEEKEND WITH
A SIGNIFICANT WARMING TREND EXPECTED EARLY NEXT WEEK.
&&
.DISCUSSION...AS OF 1:20 PM PDT THURSDAY...A MID/UPPER LEVEL TROUGH
AND ASSOCIATED STORM SYSTEM CONTINUES TO APPROACH THE PACIFIC
NORTHWEST THIS AFTERNOON. THIS FEATURE CONTINUES TO ADVECT
MOISTURE INTO NORTHERN AND CENTRAL CALIFORNIA WITH LIGHT RAINFALL
ALREADY BEING REPORTED ACROSS SONOMA COUNTY. EXPECTING
PRECIPITATION TO GENERALLY REMAIN LIGHT AS THIS SYSTEM MOVES
THROUGH THE REGION TONIGHT. SOME OF THE HIGH RESOLUTION MODELS ARE
SHOWING ISOLATED LOCATIONS IN THE COASTAL MOUNTAINS OF SANTA CRUZ
AND SAN MATEO COUNTIES PICKING UP AS MUCH AS 1/4" TO 1/2" OF
RAINFALL TONIGHT. IT IS POSSIBLE THAT RAINFALL RATES INCREASE SOME
TONIGHT AS THE FRONTAL BOUNDARY AND STRONGER SHORT-WAVE MOVES
THROUGH. OVERALL...WIDESPREAD RAINFALL IS NOT EXPECTED ACROSS THE
REGION TONIGHT. IN ADDITION...AREAS AROUND THE MONTEREY
BAY...SALINAS VALLEY AND POINTS SOUTHWARD MAY SEE LITTLE TO NO
PRECIPITATION WITH THIS SYSTEM.
AS THE TROUGH EXITS THE REGION TOMORROW...NORTHWEST FLOW ALOFT
DEVELOPS AND CHANCES FOR PRECIPITATION QUICKLY DIMINISH. COOLER
TEMPERATURES WILL REMAIN IN PLACE ON FRIDAY AND SATURDAY WITH A
PERSISTENT NORTHWEST FLOW ACROSS MUCH OF THE WEST COAST.
A SLIGHT WARMING TREND WILL BEGIN LATE IN THE WEEKEND INTO EARLY
NEXT WEEK AS A RIDGE BEGINS TO BUILD ACROSS THE EASTERN PACIFIC.
THE MEDIUM RANGE MODELS THEN FOCUS ON THE MID/UPPER LEVEL RIDGE
STRENGTHENING AND SHIFTING TOWARD THE WEST COAST. BY THE MIDDLE OF
NEXT WEEK...THE STRONG RIDGE IS FORECAST TO BE STRETCHED ALONG
THE WEST COAST AND WILL LIKELY CAUSE A SIGNIFICANT WARMING TREND
AND POSSIBLE OFFSHORE FLOW AT TIMES. WHILE WE REMAIN SEVERAL DAYS
OUT...CANNOT RULE OUT TEMPERATURES REACHING INTO THE MID 80S IN
THE SAN FRANCISCO AND MONTEREY BAY AREAS WITH MID 90S INLAND. STAY
TUNED!
&&
.AVIATION...AS OF 5:10 PM PDT THURSDAY...FOR 00Z TAFS. WEAK FRONT
IS MOVING INTO THE NORTH BAY AT THIS TIME WITH SOME SPOTTY SHOWERS
ACROSS THE REGION. SOMEWHAT SURPRISINGLY WINDS HAVE TURNED SOUTHEAST
AT THE BUOYS AND SOME AIRPORTS. NONE OF THE MESOSCALE MODELS
REALLY CAPTURED THIS BUT LATEST RAP RUN DOES AND SHOWS WINDS
SWITCHING BACK TO MORE WESTERLY BY ABOUT 05-06Z THIS EVENING SO
WOULD EXPECT SOUTHERLY WINDS AT KSFO FOR THE EVENING HOURS. CIGS
LOOK TO GENERALLY STAY AROUND 2000 FEET OR HIGHER
TONIGHT...EARLIER RAIN AT UKIAH WAS ACCOMPANIED BY BKN023. THE
FRONT SHOULD BE GONE BY SUNRISE AND BRISK NW WINDS AND DRYING
SHOULD MIX CIGS OUT FAIRLY EARLY WITH STRONG NW WINDS TOMORROW
AFTERNOON POSSIBLE AT KSFO.
VICINITY OF KSFO...EXPECT SOUTHERLY WINDS TO CONTINUE THIS EVENING
AS WEAK FRONT MOVES THROUGH WITH WIND GUSTS IN EXCESS OF 15 KT.
CIGS SHOULD STAY ABOVE 2000 FEET IN GENERAL WITH POSSIBLE LIGHT
RAIN SHOWERS THIS EVENING. LOW TO MEDIUM CONFIDENCE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...FRONT IS TO THE NORTH AND LOW
CLOUDS WILL INCREASE AFTER 03Z ALONG THE COAST...THEN STAY IN
PLACE OVERNIGHT WITH SOME VICINITY SHOWERS/DRIZZLE POSSIBLE AT
KMRY. CLEARING SHOULD OCCUR BY 18Z FRIDAY WITH GUSTY NW WINDS
FRIDAY AFTERNOON. MEDIUM CONFIDENCE.
&&
.MARINE...AS OF 1:20 PM PDT THURSDAY...GENERALLY LIGHT BUT
OCCASIONALLY GUSTY NORTHWEST WINDS ARE EXPECTED TONIGHT AS A COLD
FRONT APPROACHES THE CENTRAL CALIFORNIA COAST. THIS WEAK COLD FRONT
WILL BRING A SLIGHT CHANCE OF SHOWERS TO THE COASTAL WATERS THROUGH
THIS EVENING AS IT MOVES ACROSS THE REGION. WINDS WILL BEGIN TO
INCREASE AND SEA CONDITIONS WILL DETERIORATE ONCE AGAIN FRIDAY
AFTERNOON AS THE SURFACE PRESSURE GRADIENT STRENGTHENS ALONG THE
CALIFORNIA COAST.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 9 PM
&&
$$
PUBLIC FORECAST: RGASS
AVIATION: RWW
MARINE: CW
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
901 AM PDT WED MAY 7 2014
.SYNOPSIS...A WEAK COLD FRONT WILL BRING A SLIGHT CHANCE OF LIGHT
RAIN OR DRIZZLE TO THE AREA THURSDAY AND THURSDAY NIGHT. OTHERWISE
DRY AND MILD WEATHER IS FORECAST THROUGH THE REMAINDER OF THE WEEK
AND INTO THE UPCOMING WEEKEND.
&&
.DISCUSSSION...AS OF 8:50 AM PDT WEDNESDAY...STRATO-CU STILL
REMAINS FIRMLY ENTRENCHED ALONG THE COAST FROM SAN MATEO TO PT SUR
AND INLAND THROUGH PACHECO PASS. ELSEWHERE...MOSTLY SUNNY SKIES
PREVAIL THIS MORNING. FOR THE REST OF TODAY...EXPECT THE PESKY
STRATO-CU TO SLOWLY ERODE BACK TO THE COAST. LATEST HI-RES MODELS...
LIKE THE HRRR...KEEP CLOUDS AROUND MRY BAY AND THE SAN MATEO
COAST FOR THE REST OF THE DAY. THIS SEEMS PLAUSIBLE GIVEN THE
LATEST SATELLITE IMAGERY AND CONTINUED ONSHORE FLOW. THE MORE
NOTABLE WEATHER FEATURE WILL BE THE STRONG NORTHERLY WINDS TODAY.
THE N-S GRADIENT IS FORECAST TO INCREASE AGAIN THIS
AFTERNOON...WITH VERY WINDS CONDITIONS OVER THE COASTAL WATERS AND
ALONG THE COAST.
NO UPDATE IS PLANNED AT THIS TIME. CURRENT FORECAST IS ON TRACK.
THE NEXT FORECAST CHALLENGE WILL BE LOW CONFIDENCE RAIN CHANCES ON
THURSDAY. A WEAK TROUGH IS FORECAST TO MOVE THROUGH ON THURSDAY
BRINGING A SLIGHT CHANCE OF RAIN TO THE REGION. MODEL GUIDANCE
CONTINUES TO SHOW THAT THE BEST CHANCE FOR PRECIP REMAINS OVER THE
NORTHERN HALF OF THE CWA...OR ABOUT NORTH OF MONTEREY BAY. IF RAIN
DOES FALL...AMOUNTS WILL BE LIGHT AND A ONLY A FEW HUNDREDTHS.
.PREVIOUS DISCUSSION...THE UPPER LOW ASSOCIATED WITH THE THURSDAY
SYSTEM IS FORECAST TO MOVE INTO THE PACIFIC NORTHWEST BY LATE
FRIDAY NIGHT AND THEN INTO THE NORTHERN GREAT BASIN BY SATURDAY
NIGHT. THIS COULD TIGHTEN THE SURFACE PRESSURE GRADIENTS TO RESULT
IN GUSTY NORTHERLY WINDS IN OUR HILLS ON SATURDAY NIGHT AND SUNDAY
MORNING. WARMER WEATHER IS EXPECTED BY SUNDAY AND INTO NEXT WEEK
AS DRY NORTHERLY FLOW DEVELOPS AND AN UPPER RIDGE BEGINS TO
DEVELOP NEAR THE COAST.
&&
.AVIATION...AS OF 4:20 AM PDT WEDNESDAY...MAINLY VFR CONDITIONS
WILL PREVAIL AFTER 16Z. MODERATE CONFIDENCE. ANOTHER DAY OF STRONG
WEST TO NORTHWEST WINDS ARE IN STORE FOR THE REGION THIS AFTERNOON
INTO THE EARLY EVENING HOURS. OTHERWISE...A STORM SYSTEM IS
FORECAST TO MOVE SOUTH TOWARD THE REGION EARLY THURSDAY
MORNING...BRINGING POSSIBLE MVFR CIGS AT THE VERY END OF THE
FORECAST PERIOD.
VICINITY OF KSFO...PATCHY LOW CLOUDS SURROUND THE BAY...WITH SFO ON
THE EDGE OF CLOUDS. SCT CLOUDS MAY IMPACT THE TERMINAL THROUGH THE
16Z HOUR...LOW CONFIDENCE. OTHERWISE...WEST WINDS WILL INCREASE
SIGNIFICANTLY THIS AFTERNOON...WITH WIND GUSTS TO 35 KT PROBABLE.
KSFO BRIDGE APPROACH...PATCHES OF SCT LOW CLOUDS MAY IMPACT THE
APPROACH THROUGH THE 16Z HOUR PREVENTING VISUALS.
MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH AT LEAST THE 18Z
HOUR...LOW CONFIDENCE. NUMERICAL GUIDANCE IS ALL OVER THE PLACE
WITH CLEARING TIMES...FROM 15Z TO AN ALL DAY EVENT. THE MODELS ARE
IN BETTER AGREEMENT THAT KSNS WILL SEE CLEARING BETWEEN 18Z AND
19Z...WHEREAS KMRY IS A BIT MORE PESSIMISTIC. THE HRRR AND LAMP
INDICATE AN ALL DAY EVENT...SO WENT WITH A LATER CLEARING TIME OF
19Z. AGAIN LOW CONFIDENCE.
&&
.MARINE...AS OF 08:50 AM PDT WEDNESDAY...ROUGH SEAS WITH MODERATE
TO OCCASIONALLY STRONG NORTHERLY WINDS WILL CONTINUE ACROSS THE
WATERS THROUGH THIS EVENING. A WEAK COLD FRONT WILL PASS OVER THE
WATERS LATE TONIGHT INTO THURSDAY. THIS FRONT WILL DISRUPT THE
SURFACE PRESSURE GRADIENT WHICH WILL RESULT IN DECREASING WINDS
AND IMPROVING SEA CONDITIONS. WINDS WILL INCREASE ONCE AGAIN
FRIDAY EVENING AS THE SURFACE PRESSURE GRADIENT STRENGTHENS ALONG
THE CALIFORNIA COAST.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT ARENA TO PT REYES 10-60 NM
SCA...PT REYES TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PINOS 10-60 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...ROUGH BAR ADVISORY FOR SF BAR UNTIL 3 PM
SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM
SCA...SF BAY SOUTH OF THE BAY BRIDGE FROM 1 PM
SCA...MONTEREY BAY FROM 1 PM
&&
$$
PUBLIC FORECAST: SIMS
AVIATION: RILEY
MARINE: LARRY
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
425 AM PDT WED MAY 7 2014
.SYNOPSIS...A WEAK COLD FRONT WILL BRING A SLIGHT CHANCE OF LIGHT
RAIN OR DRIZZLE TO THE AREA THURSDAY AND THURSDAY NIGHT. OTHERWISE
DRY AND MILD WEATHER IS FORECAST THROUGH THE REMAINDER OF THE WEEK
AND INTO THE UPCOMING WEEKEND.
&&
.DISCUSSSION...AS OF 3:37 AM PDT WEDNESDAY...SATELLITE IMAGERY
SHOWS MOSTLY CLEAR SKIES ACROSS THE NORTHERN PORTION OF THE
DISTRICT WITH SOME AREAS OF STRATO-CU OVER THE EAST BAY...THE SAN
FRANCISCO PENINSULA...AND AROUND THE MONTEREY BAY AND NORTHERN
MONTEREY COUNTY. THE SURFACE PRESSURE GRADIENTS ARE MODERATE TO
STRONG ONSHORE WITH 2.4 MB FROM SFO-SAC...AND STRONG NORTHERLY
WITH 5.1 MB FROM ACV TO SFO. GRADIENTS ARE FORECAST TO TIGHTEN
AGAIN THIS AFTERNOON FOR ENHANCED ONSHORE SEA BREEZES. HIGH
TEMPERATURES ARE EXPECTED TO BE SIMILAR TO THOSE ON TUESDAY WITH
60S AND 70S MOST AREAS...80S IN THE WARMEST INTERIOR SECTIONS.
ON THURSDAY A WEAK UPPER LEVEL SYSTEM WILL APPROACH THE PACIFIC
NORTHWEST AND BRING THE POSSIBILITY FOR SOME LIGHT PRECIP ACROSS
MAINLY THE NORTHERN PORTIONS OF THE DISTRICT LATE THURSDAY THROUGH
THURSDAY NIGHT. CONFIDENCE IS LOW AS THE MAIN MOISTURE FIELD IS
FORECAST TO BE WELL TO THE NORTH. IF RAIN DOES FALL...AMOUNTS WILL
ALMOST CERTAINLY BE UNDER A TENTH OF AN INCH.
THE UPPER LOW ASSOCIATED WITH THE THURSDAY SYSTEM IS FORECAST TO
MOVE INTO THE PACIFIC NORTHWEST BY LATE FRIDAY NIGHT AND THEN
INTO THE NORTHERN GREAT BASIN BY SATURDAY NIGHT. THIS COULD
TIGHTEN THE SURFACE PRESSURE GRADIENTS TO RESULT IN GUSTY
NORTHERLY WINDS IN OUR HILLS ON SATURDAY NIGHT AND SUNDAY MORNING.
WARMER WEATHER IS EXPECTED BY SUNDAY AND INTO NEXT WEEK AS DRY
NORTHERLY FLOW DEVELOPS AND AN UPPER RIDGE BEGINS TO DEVELOP NEAR
THE COAST.
&&
.AVIATION...AS OF 4:20 AM PDT WEDNESDAY...MAINLY VFR CONDITIONS
WILL PREVAIL AFTER 16Z. MODERATE CONFIDENCE. ANOTHER DAY OF STRONG
WEST TO NORTHWEST WINDS ARE IN STORE FOR THE REGION THIS AFTERNOON
INTO THE EARLY EVENING HOURS. OTHERWISE...A STORM SYSTEM IS
FORECAST TO MOVE SOUTH TOWARD THE REGION EARLY THURSDAY
MORNING...BRINGING POSSIBLE MVFR CIGS AT THE VERY END OF THE
FORECAST PERIOD.
VICINITY OF KSFO...PATCHY LOW CLOUDS SURROUND THE BAY...WITH SFO ON
THE EDGE OF CLOUDS. SCT CLOUDS MAY IMPACT THE TERMINAL THROUGH THE
16Z HOUR...LOW CONFIDENCE. OTHERWISE...WEST WINDS WILL INCREASE
SIGNIFICANTLY THIS AFTERNOON...WITH WIND GUSTS TO 35 KT PROBABLE.
KSFO BRIDGE APPROACH...PATCHES OF SCT LOW CLOUDS MAY IMPACT THE
APPROACH THROUGH THE 16Z HOUR PREVENTING VISUALS.
MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH AT LEAST THE 18Z
HOUR...LOW CONFIDENCE. NUMERICAL GUIDANCE IS ALL OVER THE PLACE
WITH CLEARING TIMES...FROM 15Z TO AN ALL DAY EVENT. THE MODELS ARE
IN BETTER AGREEMENT THAT KSNS WILL SEE CLEARING BETWEEN 18Z AND
19Z...WHEREAS KMRY IS A BIT MORE PESSIMISTIC. THE HRRR AND LAMP
INDICATE AN ALL DAY EVENT...SO WENT WITH A LATER CLEARING TIME OF
19Z. AGAIN LOW CONFIDENCE.
&&
.MARINE...AS OF 02:40 AM PDT WEDNESDAY...MODERATE TO OCCASIONALLY
STRONG WINDS WILL CONTINUE OVER THE WATERS THROUGH THIS EVENING AS
SURFACE HIGH PRESSURE DOMINATES THE EASTERN PACIFIC. WINDS WILL
SHIFT TO A WESTERLY DIRECTION ON THURSDAY MORNING AS A STORM
SYSTEM CLIPS NORTHERN CA. OTHERWISE...HIGH PRESSURE WILL ONCE
AGAIN SHIFT WINDS TO THE NORTHWEST AND CONTINUE INTO THE WEEKEND.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PT REYES 0-10 NM
SCA...PT REYES TO PIGEON PT 0-10 NM
SCA...PIGEON PT TO PT PINOS 0-10 NM
SCA...PT ARENA TO PT REYES 10-60 NM
SCA...PT REYES TO PIGEON PT 10-60 NM
SCA...PIGEON PT TO PT PINOS 10-60 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...ROUGH BAR ADVISORY FOR SF BAR UNTIL 3 PM
SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 1 PM
SCA...SF BAY SOUTH OF THE BAY BRIDGE FROM 1 PM
SCA...MONTEREY BAY FROM 1 PM
&&
$$
PUBLIC FORECAST: SIMS
AVIATION/MARINE: RILEY
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS NEW YORK NY
1103 PM EDT THU MAY 8 2014
.SYNOPSIS...
A WARM FRONT WILL SLOWLY APPROACH THROUGH FRIDAY...MOVE INTO THE
REGION FRIDAY NIGHT...THEN LIFT TO THE NORTH ON SATURDAY. A COLD
FRONT WILL PASS SATURDAY NIGHT..FOLLOWED BY HIGH PRESSURE SUNDAY
INTO MONDAY. A SERIES OF FRONTAL BOUNDARIES WILL THEN BRING
UNSETTLED WEATHER INTO THE REST OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
STILL SEEING PATCHY FOG ACROSS LONG ISLAND AND SOUTHERN CT.
STILL THINK WINDS ACROSS ERN SECTIONS WILL VEER MORE SE
OVERNIGHT...WHICH COULD LEAD TO LOCALLY DENSE FOG THERE
LATE TONIGHT.
SHOWERS AND TSTMS HAVE DEVELOPED AS EXPECTED OVER CENTRAL NY
STATE NEAR AN H8 WARM FRONT...IN RESPONSE TO MID LEVEL FORCING VIA
AN H5 VORT MAX RIDING SE FROM ATOP THE UPPER RIDGE AXIS TO THE
WEST...AND ALSO AS H8 THETA-E ADVECTION AND MOISTURE CONVERGENCE
INCREASE. THESE SHOULD EXPAND SE-WARD INTO OUR CWA...FIRST INTO
THE LOWER HUDSON VALLEY AND POSSIBLY NYC METRO JUST AFTER
MIDNIGHT...AND THEN INTO THE REST OF THE AREA LATE ESPECIALLY
ACROSS SOUTHERN CT AND LONG ISLAND PER LATEST HRRR/RAP. RAP FCST
MUCAPE UP TO 500 J/KG ALSO SUGGESTS CONTINUED POTENTIAL FOR
ELEVATED THUNDER AS THIS ACTIVITY EXPANDS SE-WARD.
TEMPS SHOULD NOT FALL MUCH BELOW THEIR CURRENT VALUES...WITH LOWS
50-55.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FOR FRIDAY...THE AXIS OF THE UPPER LEVEL RIDGE MOVES ACROSS.
PWATS DECREASE BY A FEW TENTHS OF AN INCH.
AT THE SURFACE...A LACK OF PROGRESSION WILL BE APPARENT AS THE
PARENT LOW DEEPENS A FEW MB IN TERMS OF CENTRAL PRESSURE AND WARM
FRONT MAKES LITTLE PROGRESS NORTHEASTWARD. THE FLOW AT THE SURFACE
REMAINS OUT OF THE SOUTHEAST AND INCREASES. THIS WILL MAKE FOR A
PERSISTENT INVERSION AND MOISTURE UNDERNEATH THAT WILL REMAIN.
THE MODEL QPF SHOWS THE AREA OF SHOWERS MOVING NORTHEAST OF THE
REGION BY FRIDAY AFTERNOON WITH VERY LIGHT SHOWERS REMAINING
BEHIND IT FOR THE REST OF THE DAY. THE POPS FOR THESE SHOWERS ARE
STILL MAINLY CHANCE WITH OTHERWISE FOG AND DRIZZLE AS LOW LEVEL
MOISTURE REMAINS BENEATH A PERSISTENT INVERSION.
USED A 12Z NAM/GFS BLEND FOR MAX TEMPS WITH SOME MANUAL
ADJUSTMENTS. THESE ARE A LITTLE WARMER THAN THE PREVIOUS DAY DUE
TO TEMPS ALOFT INCREASING A FEW DEGREES BUT UNCERTAINTY IS THERE.
WENT AT LEAST SEVERAL DEGREES BELOW THE GFS/NAM MOS GUIDANCE WHICH
IS TOO OPTIMISTIC IN LIFTING CEILINGS DURING THE DAY.
FOR FRIDAY NIGHT...A TRANSITION TO A MORE MERIDIONAL FLOW OCCURS
WITH THE RIDGE MOVING OFFSHORE AND UPPER LEVEL SOUTHWEST TO
NORTHEAST JET STREAK APPROACHING AHEAD OF THE UPPER LEVEL LOW IN
ONTARIO. THE SOUTHEAST FLOW AT THE SURFACE CONTINUES THROUGH THE
EVENING AND THEN BECOMES SOUTHWEST OVERNIGHT. THE WARM FRONT WILL
BE WITHIN THE REGION BY SATURDAY MORNING. HOWEVER...EVEN THOUGH
THIS MODELS ARE SHOWING THIS...THERE IS SOME HESITATION UPON
TOTALLY COUNTING IN THIS SOLUTION BECAUSE OF THE RELATIVELY COOLER
SEA SURFACE TEMPERATURES THAT MAY PROLONG THE PASSAGE OF THE WARM
FRONT...PERHAPS MORE TOWARDS SATURDAY MORNING IN LATER MODEL
RUNS. THE FORECAST HERE ESPECIALLY CONCERNING THE FRONTAL PASSAGE
IS OF LOWER CONFIDENCE WITH CHANGES POSSIBLE WITH SUBSEQUENT
FORECASTS.
IN ANY CASE...THE LOW LEVEL MOISTURE UNDERNEATH THE INVERSION WILL
REMAIN AND THE MODELS CONTINUE TO PORTRAY LITTLE QPF THROUGH THE
NIGHT WITH SOME MORE ORGANIZED SHOWER ACTIVITY MOVING IN OVERNIGHT.
THINKING THE LOW CLOUDS AND DRIZZLE WOULD PROBABLY CONTINUE GIVEN
THESE FACTORS. ALSO THE CHANCE FOR SHOWERS WILL CONTINUE.
IN ADDITION...INSTABILITY WILL INCREASE AS WELL ESPECIALLY AFTER
THE WARM FRONT MOVES THROUGH. THEREFORE...STILL HAVE ISOLATED
THUNDERSTORMS IN THE FORECAST FOR THIS TIME FRAME.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
UNSETTLED WEATHER ON TAP FOR MOST OF THE LONG TERM PERIOD.
WARM FRONT LIFTS NORTH THROUGH THE REGION AS LOW PRES PASSES WELL
NORTH OF THE REGION. SHOWERS WITH SCATTERED THUNDERSTORMS ARE LIKELY
THROUGH THE DAY...TAPERING OFF AT NIGHT AS H5 TROUGH SWINGS THROUGH
THE REGION AND THEN HIGH PRES BUILDS INTO THE REGION. INCREASING SW
FLOW BEHIND THE WARM FRONT WILL PUSH TEMPS WELL INTO THE 70S...
POSSIBLY APPROACHING 80 ACROSS THE URBANIZED AREAS OF NE NJ. TEMPS
WILL BE SLIGHTLY COOLER NEAR THE COASTS.
WITH HIGH PRES OVER THE AREA...IT APPEARS AS IF MOTHER`S DAY WILL BE
NICEST DAY OF THE LONG TERM PERIOD WITH MOSTLY SUNNY SKIES AND TEMPS
IN THE MID TO UPPER 70S...POSSIBLY AROUND 80 JUST WEST OF THE HUDSON
RIVER.
THE HIGH DEPARTS ON MONDAY...AND THEN A DEEP UPPER TROUGH DIGS INTO
THE CENTRAL U.S. AND SLOWLY TRACKS EAST DURING THE WEEK. SEVERAL
WEAK WAVES OF LOW PRES WILL DEVELOP AHEAD OF THIS TROUGH AND WILL
APPROACH THE NORTHEAST DURING THIS TIME. AS A RESULT...WILL CARRY AT
LEAST A CHANCE OF POPS FOR SHOWERS/TSTMS FROM MONDAY AFTERNOON
THROUGH FRIDAY. MODEL GUIDANCE INDICATES THE TROUGH WILL SLIDE
OFFSHORE ON FRIDAY.
A MILD AIR MASS OVERSPREADS THE REGION WITH SW FLOW AHEAD OF THE
TROUGH. HIGHS WILL GENERALLY TOP OFF IN THE MID-UPPER 70S...EXCEPT
SLIGHTLY COOLER NEAR THE COASTS...THROUGH MUCH OF THE WEEK. AS THE
TROUGH APPROACHES...HIGHS DROP INTO THE LOW-MID 70S TOWARDS THE END
OF THE WEEK.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
A WARM FRONT WILL REMAIN SW OF THE REGION THRU THE TAF PERIOD.
MAINLY IFR OR LOWER THRU THE TAF PERIOD. BR WILL REDUCE VSBY INTO
FRI MRNG. A CHC OF -SHRA TNGT...ESPECIALLY AFT 05-06Z. THREAT OF
SHOWERS DIMINISH NEAR 12-14Z. ISO TSTM ALSO POSSIBLE...BUT NOT HIGH
ENOUGH COVERAGE FOR A MENTION IN TAFS.
WINDS MOSTLY ESE UNDER 8KT OR LIGHT AND VARIABLE OVERNIGHT...SLOWLY
VEERING SE ON FRI. SPEEDS STILL MAINLY BLW 10KT.
.OUTLOOK FOR 00Z SAT THROUGH MONDAY...
.SAT...BECOMING VFR IN THE AFTN WITH WINDS SHIFTING TO THE SW. CHC
SHRA/TSTMS LATE.
.SUN...EARLY MRNG SHRA/TSTMS POSSIBLE. OTHERWISE BECOMING VFR WITH
NW FLOW.
.MON-TUE...PERIODS OF MVFR OR LOWER WITH SW FLOW.
&&
.MARINE...
A WARM FRONT WILL SLOWLY APPROACH AND REMAIN TO THE S THROUGH
FRI...AND THEN MOVE INTO AT LEAST A PORTION OF THE WATERS FRI
NIGHT. CONFIDENCE IS HIGH ON OCEAN SEAS REMAINING SUB-SCA INTO
MIDDAY SAT...BUT THEN INCREASING SW FLOW SHOULD PUSH OCEAN SEAS
TO 4-6 FT LATE SAT AFTERNOON INTO SAT NIGHT. SEAS SHOULD THEN
SUBSIDE ON SUNDAY.
PERSISTENT SOUTHERLY FLOW WILL PUSH OCEAN SEAS UP TO SCA CRITERIA
STARTING ON TUE...POSSIBLY LASTING THROUGH THE END OF THE
UPCOMING WEEK.
&&
.HYDROLOGY...
GENERALLY...NO WIDESPREAD SIGNIFICANT PRECIP OF 1/2 INCH OR MORE
IS EXPECTED THROUGH EARLY NEXT WEEK.
FOR THE SHORT TERM THROUGH FRIDAY NIGHT...OUTSIDE OF ANY ISOLATED
THUNDERSTORMS WHICH COULD RESULT IN LOCALLY HEAVY RAIN...TOTAL
RAIN AMOUNTS WILL BE UP TO AROUND A QUARTER OF AN INCH.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JM/MPS
NEAR TERM...GOODMAN/JM
SHORT TERM...GOODMAN/JM
LONG TERM...MPS
AVIATION...JC
MARINE...GOODMAN/JM/MPS
HYDROLOGY...JM/MPS
AREA FORECAST DISCUSSION
NWS ALBANY NY
752 PM EDT THU MAY 8 2014
.SYNOPSIS...
A WARM FRONT STRETCHING FROM THE THE LOWER GREAT LAKES TO THE MID
ATLANTIC STATES WILL SLOWLY SHIFT NORTHEASTWARD TONIGHT. THE WARM
FRONT WILL GRADUALLY MOVE ACROSS OUR REGION THROUGH FRIDAY...WITH
SOME RAIN SHOWERS AND POSSIBLY A THUNDERSTORM. MUCH MILDER
TEMPERATURES WILL BE USHERED IN ON SATURDAY ALONG WITH A CONTINUED
THREAT FOR SHOWERS AND THUNDERSTORMS...AS A WEAK COLD FRONT
CROSSES THE AREA.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 745 PM EDT...MID LEVEL CLOUDS/MOISTURE SPILLING
SOUTHEASTWARD OVER THE TOP OF AN UPPER LEVEL RIDGE AXIS
POSITIONED OVER THE CENTRAL GREAT LAKES. THIS MID LEVEL MOISTURE
WILL GRADUALLY OVERSPREAD THE REGION TONIGHT. THE BEST CHANCE FOR
SHOWERS THIS EVENING WILL BE ACROSS THE ADIRONDACKS...AS SOME
RADAR REFLECTIVITIES CAN BE SEEN UPSTREAM ON THE KTYX RADAR. THESE
SHOWERS ARE BEING USHERED IN BY THE NORTHWEST FLOW ALOFT. LOW
LEVELS ARE DRY ACROSS MUCH OF THE AREA...SO IT WILL TAKE TIME TO
SATURATE. THUS WILL MENTION ONLY SLIGHT CHANCE TO CHANCE POPS
THROUGH THE EVENING HOURS. AFTER MIDNIGHT...HI RES MODELS SUCH AS
THE HRRR AND LOCAL WRF INDICATING CELLULAR SHOWERS DEVELOPING AND
INCREASING IN COVERAGE ASSOCIATED WITH ELEVATED INSTABILITY. SO
WILL RAISE POPS ESPECIALLY WEST OF ALBANY AND WILL MAINTAIN
POSSIBLE ISOLATED THUNDER. ALSO...THE LOW LEVEL FLOW WILL START TO
INCREASE FROM THE SOUTH...WHICH WILL DRAW STRATUS CLOUDS NORTHWARD
LATE TONIGHT INTO FRIDAY MORNING.
INCREASING CLOUDS WILL RESULT IN A RELATIVELY MILD NIGHT...WITH
MAINLY LOWER TO MID 50S FOR LOWS EXCEPT UPPER 40S IN THE
ADIRONDACKS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
UNTIL WE CAN GET THE FRONTAL BOUNDARIES THROUGH OUR REGION WHICH
WILL NOT BE UNTIL EARLY NEXT WEEK...THERE WILL BE A CHANCE OF
SHOWERS AND THUNDERSTORMS EACH DAY. AT THIS TIME IT LOOKS LIKE THE
MOST ACTIVE DAY WILL BE SATURDAY AS MLMUCAPES RISE TO BTWN 500 AND
1000 J/KG SATURDAY AFTERNOON AS THE WARM FRONT AND THEN THE COLD
FRONT APPROACH OUR REGION. SUNDAY LOOKS TO BE THE BETTER OF THE
WEEKEND DAYS ALTHOUGH THERE STILL COULD BE A LINGERING SHOWER OR TWO.
ON FRIDAY EXPECT THE COOLER OF THE WEEKEND DAYS AS THERE WILL BE A
GOOD DEAL OF CLOUD COVER FROM LOWER LEVEL STRATUS WORKING
NORTHWARD WHILE CONVECTION UPSTREAM WILL PROVIDE SOME HIGH CLOUDS. HIGHS
ARE EXPECTED TO BE IN THE 60S. LOWS FRIDAY NIGHT WILL GENERALLY BE
IN THE 50S. HIGHS ON SATURDAY AND SUNDAY ARE EXPECTED TO GENERALLY
BE IN THE 70S WITH LOWS SATURDAY NIGHT IN THE 40S AND 50S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE LONG TERM PERIOD WILL BE CHARACTERIZED BY MILD TEMPERATURES AND
UNSETTLED WEATHER AS A SERIES OF FRONTAL BOUNDARIES LINGER ACROSS
THE REGION.
AT THE START OF THE LONG TERM PERIOD...ZONAL FLOW WILL BE LINGERING
ALOFT ACROSS THE REGION WITH AN INCREASINGLY AMPLIFIED PATTERN
UPSTREAM...AS PIECES OF PACIFIC ENERGY CARVE OUT A DEEP UPPER-LEVEL
TROUGH ACROSS THE CENTRAL PLAINS. AT THE SURFACE...WAVES OF LOW
PRESSURE EJECTING OUT OF THE ROCKIES WILL EXTEND FRONTAL BOUNDARIES
ACROSS THE GREAT LAKES REGION...AND EASTWARD INTO PORTIONS OF THE
FORECAST AREA.
THE LATEST LONG TERM GUIDANCE CONTINUES TO DEPICT SIGNIFICANT
UNCERTAINTY REGARDING HOW THE SYNOPTIC PATTERN EVOLVES FOR NEXT
WEEK. HOWEVER...THE AFOREMENTIONED FRONTAL BOUNDARIES WILL BE
LINGERING ACROSS THE REGION...AND WITH LOW-LEVEL SOUTHERLY FLOW
ADVECTING MOISTURE INTO THE REGION...WILL PROVIDE THE FOCUS FOR
PRECIPITATION. GIVEN THE INCREASINGLY AMPLIFIED PATTERN...BELIEVE A
SLOWER SOLUTION REGARDING THE EASTWARD TRACK OF THE CENTRAL PLAINS
LOW WILL EVOLVE...MEANING THAT THE FOCUS FOR CONVECTION WILL LIKELY
BE MORE OF A SCATTERED NATURE MONDAY AND TUESDAY. WITH DEWPOINTS
RISING INTO THE UPPER 50S AND EVEN LOW 60S WITH SHOWALTER VALUES
BETWEEN 0C AND -2C...ENOUGH SURFACE AND MID-LEVEL INSTABILITY SHOULD
BE IN PLACE FOR SCATTERED SHOWERS AND THUNDERSTORMS.
THE LOW PRESSURE SYSTEM SHOULD SLOWLY APPROACH FROM THE CENTRAL
PLAINS BY MIDWEEK...PROVIDING HIGHER CHANCES FOR PRECIPITATION AS A
COLD FRONT MOVES ACROSS THE REGION. HAVE GONE WITH CHANCE POPS
BEGINNING MONDAY AND CONTINUING THROUGH THE REMAINDER OF THE LONG
TERM DUE TO THE HIGH MODEL UNCERTAINTY.
HIGH TEMPERATURES THROUGHOUT THE LONG TERM PERIOD WILL GENERALLY
RANGE FROM NEAR 70 ACROSS THE HIGHER TERRAIN TO UPPER 70S IN VALLEY
LOCATIONS...WITH THE POTENTIAL TO REACH INTO THE LOW TO MID 80S IN
THE MID HUDSON VALLEY MONDAY AND TUESDAY. LOWS WILL GENERALLY RANGE
FROM LOW 50S TO LOW 60S.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
MID LEVEL CLOUDS WILL OVERSPREAD THE KALB/KGFL/KPSF TERMINALS THIS
EVENING...WITH A LOW PROBABILITY OF A FEW SHOWERS WITH THE MID
LEVEL CLOUD DECK. KPOU SHOULD REMAIN WITH LOW STRATUS IN MVFR
RANGE...ALTHOUGH SATELLITE IMAGERY AND LOCAL OBSERVATIONS INDICATE
SOME BREAKS WILL BE POSSIBLE THIS EVENING.
SHOWERS ARE EXPECTED TO INCREASE IN COVERAGE AFTER
MIDNIGHT...MAINLY SCATTERED ACROSS THE TERMINALS BUT PERHAPS
BECOMING NUMEROUS SLIGHTLY BEFORE OR TOWARDS DAYBREAK AS A WARM
FRONT APPROACHES FROM THE SOUTH. WILL INDICATE VCSH OR PREVAILING
-SHRA LATE TONIGHT THROUGH FRIDAY MORNING. CIGS ARE ALSO EXPECTED
TO DETERIORATE TO MVFR THEN POSSIBLE IFR AT KPOU/KPSF LATE TONIGHT
INTO FRIDAY MORNING...AS THE LOW LEVEL FLOW BECOME SOUTHERLY WITH
LOW STRATUS CLOUDS EXPECTED TO MIGRATE NORTHWARD FROM COASTAL AREAS.
A BREAK IN THE SHOWERS IS POSSIBLE FRIDAY AFTERNOON...AND CIGS
SHOULD RISE SOMEWHAT. HOWEVER...STILL OVC CIGS IN MVFR RANGE
EXPECTED THROUGH 00Z SATURDAY.
SURFACE WINDS WILL BE LIGHT AND VARIABLE TONIGHT...BECOMING
SOUTHEAST AROUND 5-10 KT FRIDAY MORNING.
OUTLOOK...
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
SATURDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
SUNDAY TO SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY TO TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
&&
.FIRE WEATHER...
A WARM FRONT STRETCHING FROM THE THE LOWER GREAT LAKES TO THE MID
ATLANTIC STATES WILL SLOWLY SHIFT NORTHEASTWARD THIS EVENING. THE
WARM FRONT WILL GRADUALLY MOVE ACROSS THE REGION TONIGHT THROUGH
FRIDAY WITH SOME ADDITIONAL RAIN SHOWERS AND POSSIBLY A
THUNDERSTORM. MUCH MILDER TEMPERATURES WILL BE USHERED IN ON
SATURDAY ALONG WITH A CONTINUED THREAT FOR SHOWERS AND
THUNDERSTORMS...AS A WEAK COLD FRONT CROSSES THE AREA.
RELATIVE HUMIDITIES WILL RECOVER TO BETWEEN 80 AND 100 PERCENT
TONIGHT...ONLY FALL TO 60 TO 80 PERCENT ON FRIDAY...RECOVER TO 90
TO 100 PERCENT ON FRIDAY NIGHT...AND FALL TO 45 TO 55 PERCENT ON
SATURDAY.
WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT. SOUTHEAST AT 5 TO 10
MPH ON FRIDAY. SOUTHEAST TO SOUTHWEST AT 5 TO 10 MPH ON FRIDAY
NIGHT AND SOUTHWEST AT 5 TO 10 MPH ON SATURDAY.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC PROBLEMS ARE ANTICIPATED DURING THE NEXT
FIVE DAYS.
A WARM FRONT WILL SLOWLY APPROACH OUR REGION FROM THE SOUTHERN
GREAT LAKES AND MID ATLANTIC REGION. AS THE FRONT STARTS TO LIFT
FURTHER NORTHEASTWARD...THE CHANCE FOR RAIN SHOWERS AND
THUNDERSTORMS WILL MOVE ACROSS THE ENTIRE REGION LATER TONIGHT
INTO FRIDAY. THERE WILL BE A CONTINUED THREAT FOR SHOWERS AND
SCATTERED THUNDERSTORMS INTO SATURDAY...AS A WEAK COLD FRONT
CROSSES THE REGION. BEHIND THE FRONT...DRY WEATHER WILL RETURN FOR
SUNDAY.
RAINFALL WILL BE VARIABLE ACROSS THE REGION DUE TO THE SCATTERED
NATURE OF THE SHOWERS AND THUNDERSTORMS. OVERALL...MOST LOCATIONS
LOOK TO RECEIVE BETWEEN ONE HALF INCH AND ONE INCH OF RAINFALL
THROUGH SUNDAY NIGHT...WITH THE HEAVIER AMOUNTS WHERE LOCALIZED
SCATTERED THUNDERSTORMS OCCUR.
WHILE THERE MAY BE SOME MINOR RISES ON RIVERS AND STREAMS...ALL
WATERWAYS ARE EXPECTED TO STAY WITHIN THEIR BANKS...AND NO
FLOODING IS ANTICIPATED AT THIS TIME.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...11/JPV
NEAR TERM...11/JPV
SHORT TERM...11
LONG TERM...IRL
AVIATION...JPV
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
638 PM EDT WED MAY 7 2014
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY MOVE OFFSHORE THROUGH TONIGHT. A WARM
FRONT OVER THE OHIO VALLEY AND CAROLINAS WILL SLOWLY MOVE NORTHEAST
AND PASS THROUGH THE FORECAST AREA EARLY SATURDAY. A WEAK COLD
FRONT IS FORECAST TO CROSS THE AREA LATE SATURDAY OR EARLY SUNDAY
AND THEN STALL JUST SOUTH OF THE AREA. ANOTHER WARM FRONT IS
FORECAST TO CROSS THE AREA MONDAY OR TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
445 PM ESTF UPDATED AT 630 PM: TEMPS TRIMMED SEVERAL DEGREES
FURTHER THIS EVENING. NO THUNDER THRU 06Z AND PLAYED DOWN THUNDER
IN THE WORDING TIL LATE.
BEST POTENTIAL FOR ANY THUNDER AND HEAVY RAIN SHOWERS VERY LATE
TONIGHT IS E CENTRAL AND SE PA AND S 1/2 NJ..ALONG AND S OF
KABE-KBLM. THAT IS ALSO THE 18Z GFS SOLN AND I AM THINKING THAT
HAS THE BEST CHANCE OF VERIFICATION WITH PROXIMITY TO THE UNSTABLE
AIR. IN OTHER WORDS...REDEVELOPING CONVECTIVE CLUSTERS ARE USUALLY
TOWARD THE GREATEST INSTABILITY.
DIFFERENTIAL WAA IN A NW FLOW ALOFT SITUATION WITH SHORT WAVES
ASSISTING PERIODS OF LIFT. USING SPC WRF...HRRR AND RAP TO ADJUST
POPS AND A BEST MATCH TO THE GOING REALITY THIS EVENING.
BASED ON OBSERVED TRENDS AT 830 PM WILL PROBABLY SHIFT HIGHEST
POPS IN THE 06Z-15Z TIME FRAME FURTHER SOUTH AND THE WORDING AS
POSSIBLY HEAVY SHOWERS AND ISOLATED TSTMS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
A CLOUDY/SHOWERY MORNING IS EXPECTED ACROSS THE AREA WITH A BIG
RANGE IN TEMPERATURES ACROSS THE REGION DURING THE AFTN.
HAVE ALREADY CUT POPS TO 12 PCT MOST OF THE AREA 16Z-22Z TIME
FRAME...IN OTHER WORDS...I THINK ITS A RAINFREE AFTERNOON.
HIGHS OVER MARYLANDS EASTERN SHORE MAY REACH THE MID/UPPER 70S
WHILE FURTHER N OVER NRN NJ AND THE SRN POCONOS...THE HIGHS WILL
ONLY RISE MAYBE NEAR 60. SCT TSTMS ARE POSSIBLE THU AS WELL...BUT
CAPES ARE RATHER LOW...SO WE WILL JUST KEEP WORDING SCT FOR NOW.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
A WARM FRONT WILL BE WORKING ITS WAY NORTHWARD SLOWLY THU NIGHT
INTO FRI. PRECIP CHANCES WILL OCCUR ALG THE FRONT AND END (OR
DECREASE SUBSTANTIALLY) BEHIND IT. THE GFS SEEMS ANOMALOUSLY WET
COMPARED TO THE OTHER GUID EARLY FRI AND WAS IGNORED. THE HIGHEST
PRECIP CHCS ON THRU FRI WILL BE OVER NRN AREAS WHERE THE FRONT
WILL TAKE THE LONGEST TIME TO CLEAR. FOR MANY AREAS, THE BULK OF
FRI CUD BE DRY.
FRI NIGHT LOOKS CLOUDY WITH CHC POPS AS THE AREA REMAINS IN THE WARM
SECTOR, BUT A CDFNT IS APPROACHING FROM THE W. POPS WILL CONTINUE
TO INCREASE ON SAT AS THE AFOREMENTIONED CDFNT GETS CLOSER AND
CROSSES THE REGION LATER SAT. PRECIP SHUD DECREASE DURG SAT EVE
AFTER FROPA.
HIGH PRES THEN BUILDS BACK IN FOR SAT NIGHT INTO SUN. THEN THERE
IS CONSIDERABLE MDL DISAGREEMENT FOR EARLY NEXT WEEK. THE GFS IS
QUITE A BIT FASTER WITH THE NEXT LOW/CDFNT AND ASSOCD PRECIP THAN
THE ECMWF. THE GFS HAS SOME DIURNAL PRECIP ON MON BUT A BETTER
SHOT WITH THE CDFNT ON TUE. THE ECMWF IS ESSENTIALLY DRY THRU THE
PD. THERE IS THE CHANCE OF SOME DIURNAL SHWRS MON BUT THEN NOTHING
BEFORE THE CDFNT, WHICH IS AT LEAST A DAY BEHIND THE GFS. SO, IF
THE ECMWF IS CORRECT, EARLY NEXT WEEK WOULD BE DRIER THAN THE GFS
IS INDICATING, BUT THERE IS STILL A WEEK TO SORT THINGS OUT. BY
EARLY NEXT WEEK, THE MDLS BUILD AN UPR RIDGE BACK OVER THE AREA.
TEMPS WILL GENLY BE ABV NRML ON FRI BEHIND THE WMFNT AND NR OR
PSBLY BELOW NRML AHEAD OF THE FRONT (ALSO DEPENDENT ON
CLOUDS/PRECIP). THEN MOST OF THE REST OF THE UPCOMING WEEK WILL
FEATURE ABOVE NRML TEMPS WITH HIGHS NR 80 THU THE WKND INTO ERLY
NEXT WEEK.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...BKN-OVC CIGS AOA 5000 FT WITH A MVFR CIG POSSIBLY DEVELOPING
AFTER 06Z. SCT SHOWERS...MOSTLY KABE SOUTH. THUNDER POTENTIAL IN MORE
ORGANIZED HEAVY SHOWERS LIKELY AFTER 06Z WHERE IFR CONDS MAY DEVELOP
IN SHOWERS/STRATUS...PROBABLY FOR MANY TAF SITES. LIGHT WIND.
THURSDAY...MVFR CIGS MAY BREAK TO MAINLY VFR CIGS AOA 3000 FT THU
AFTN. SHOWERS MAINLY IN THE MORNING MAYBE WITH ISOLATED TSTMS. LIGHT
WIND TRENDING NE.
OUTLOOK...
THU NIGHT...MVFR CONDITIONS AT TIMES DUE TO SHWRS AND TSTMS EARLY
(MAINLY N)...AS WELL AS LOWER CLOUDS AND FOG AS WARM FRONT MOVES
NWD THRU THE REGION. MDT CONFIDENCE.
FRI AND FRI NIGHT...PRIMARILY VFR DURING THE DAY AND SOME MVFR
CONDS AT NIGHT. MDT-HIGH CONFIDENCE.
SAT...OCCASIONAL MVFR TO BRIEFLY IFR CONDITIONS IN SCATTERED
SHOWERS AND THUNDERSTORMS. MDT CONFIDENCE
SUN-SUN NIGHT...VFR. HIGH CONFIDENCE.
MON...MAINLY VFR. PSBL AFTN SHWRS/TSTMS THAT CUD LWR VSBYS/CIGS.
LOW-MDT CONFIDENCE.
&&
.MARINE...
CONDITIONS ON THE WATERS WILL REMAIN BELOW SMALL CRAFT CRITERIA
THROUGH THURSDAY. THERE MAY BE A FEW SCT TSTMS LATE TONIGHT AND
THURSDAY. WINDS LIGHT TRENDING EASTERLY WITH TIME THRU THURSDAY.
OUTLOOK...
SUB SCA CONDS ARE EXPECTED THU NIGHT THRU FRI. FOG MAY BE THE
GREATER CONCERN, ESPECIALLY THURSDAY NIGHT. WITH A VEERING OF
WINDS TOWARD THE SOUTH, THE CONCERN MAY MOVE OUT OF OUR AREA BY
FRIDAY NIGHT.
SEAS INCREASE OVER THE WEEKEND, BUT WE ARE PLAYING IT A BIT MORE
CONSERVATIVE DUE TO SWLY FLOW...BUT THERE IS SOME SCA POTENTIAL
THERE.
A GREATER SCA POTENTIAL OCCURS EARLY NEXT WEEK IN ADVANCE OF THE
NEXT SYS, BUT THERE ARE STILL SOME TIMING ISSUES WRT TO THIS SYS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NIERENBERG
NEAR TERM...DRAG/O`HARA 638
SHORT TERM...DRAG/O`HARA 638
LONG TERM...NIERENBERG
AVIATION...DRAG/NIERENBERG/O`HARA 638
MARINE...DRAG/NIERENBERG/O`HARA 638
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
502 PM EDT WED MAY 7 2014
.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY MOVE OFFSHORE THROUGH TONIGHT. A WARM
FRONT OVER THE OHIO VALLEY AND CAROLINAS WILL SLOWLY MOVE
NORTHEAST AND PASS THROUGH THE FORECAST AREA AROUND FRIDAY. A WEAK
COLD FRONT IS FORECAST TO CROSS THE AREA LATE SATURDAY OR EARLY
SUNDAY AND THEN STALL JUST SOUTH OF THE AREA. ANOTHER WARM FRONT
IS FORECAST TO CROSS THE AREA MONDAY OR TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
630 PM ESTF SENT 445PM: TEMPS SIGNIFICANTLY COOLER THIS EVE. NO
THUNDER THRU 06Z AND PLAYED DOWN THUNDER IN THE WORDING LATE.
BEST POTENTIAL FOR ANY THUNDER AND HEAVY RAIN SHOWERS VERY LATE
TONIGHT IS E CENTRAL AND SE PA AND S 1/2 NJ..ALONG AND S OF
KABE-KBLM.
DIFFERENTIAL WAA IN A NW FLOW ALOFT SITUATION WITH SHORT WAVES
ASSISTING PERIODS OF LIFT. USING SPC WRF...HRRR AND RAP TO ADJUST
POPS AND A BEST MATCH TO THE GOING REALITY.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
THE WARM FRONT WILL BE LIFTING ACROSS THE AREA THURSDAY. A
CLOUDY/SHOWERY DAY IS EXPECTED ACROSS THE AREA WITH A BIG RANGE IN
TEMPERATURES ACROSS THE REGION. HIGHS OVER THE DELMARVA MAY REACH
THE MID/UPPER 70S WHILE FURTHER NE OVER NRN NJ AND THE SRN
POCONOS...THE HIGHS WILL ONLY RISE INTO THE LOW 60S. SCT TSTMS ARE
POSSIBLE THU AS WELL...BUT CAPES ARE RATHER LOW...SO WE WILL JUST
KEEP WORDING SCT FOR NOW.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
A WARM FRONT WILL BE WORKING ITS WAY NORTHWARD SLOWLY THU NIGHT
INTO FRI. PRECIP CHANCES WILL OCCUR ALG THE FRONT AND END (OR
DECREASE SUBSTANTIALLY) BEHIND IT. THE GFS SEEMS ANOMALOUSLY WET
COMPARED TO THE OTHER GUID EARLY FRI AND WAS IGNORED. THE HIGHEST
PRECIP CHCS ON THRU FRI WILL BE OVER NRN AREAS WHERE THE FRONT
WILL TAKE THE LONGEST TIME TO CLEAR. FOR MANY AREAS, THE BULK OF
FRI CUD BE DRY.
FRI NIGHT LOOKS CLOUDY WITH CHC POPS AS THE AREA REMAINS IN THE WARM
SECTOR, BUT A CDFNT IS APPROACHING FROM THE W. POPS WILL CONTINUE
TO INCREASE ON SAT AS THE AFOREMENTIONED CDFNT GETS CLOSER AND
CROSSES THE REGION LATER SAT. PRECIP SHUD DECREASE DURG SAT EVE
AFTER FROPA.
HIGH PRES THEN BUILDS BACK IN FOR SAT NIGHT INTO SUN. THEN THERE
IS CONSIDERABLE MDL DISAGREEMENT FOR EARLY NEXT WEEK. THE GFS IS
QUITE A BIT FASTER WITH THE NEXT LOW/CDFNT AND ASSOCD PRECIP THAN
THE ECMWF. THE GFS HAS SOME DIURNAL PRECIP ON MON BUT A BETTER
SHOT WITH THE CDFNT ON TUE. THE ECMWF IS ESSENTIALLY DRY THRU THE
PD. THERE IS THE CHANCE OF SOME DIURNAL SHWRS MON BUT THEN NOTHING
BEFORE THE CDFNT, WHICH IS AT LEAST A DAY BEHIND THE GFS. SO, IF
THE ECMWF IS CORRECT, EARLY NEXT WEEK WOULD BE DRIER THAN THE GFS
IS INDICATING, BUT THERE IS STILL A WEEK TO SORT THINGS OUT. BY
EARLY NEXT WEEK, THE MDLS BUILD AN UPR RIDGE BACK OVER THE AREA.
TEMPS WILL GENLY BE ABV NRML ON FRI BEHIND THE WMFNT AND NR OR
PSBLY BELOW NRML AHEAD OF THE FRONT (ALSO DEPENDENT ON
CLOUDS/PRECIP). THEN MOST OF THE REST OF THE UPCOMING WEEK WILL
FEATURE ABOVE NRML TEMPS WITH HIGHS NR 80 THU THE WKND INTO ERLY
NEXT WEEK.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...BKN-OVC CIGS AOA 5000 FT WITH A MVFR CIG POSSIBLY DEVELOPING
AFTER 06Z. SCT SHOWERS...MOSTLY KABE SOUTH. THUNDER POTENTIAL IN MORE
ORGANIZED HEAVY SHOWERS POSSIBLE AFTER 06Z WHERE IFR CONDS MAY
DEVELOP IN SHOWERS/STRATUS. LIGHT WIND.
THURSDAY...MVFR CIGS MAY BREAK TO MAINLY VFR CIGS AOA 3000 FT THU
AFTN. SHOWERS MAINLY IN THE MORNING MAYBE WITH ISOLATED TSTMS. LIGHT
WIND TRENDING NE.
OUTLOOK...
THU NIGHT...MVFR CONDITIONS AT TIMES DUE TO SHWRS AND TSTMS EARLY
(MAINLY N)...AS WELL AS LOWER CLOUDS AND FOG AS WARM FRONT MOVES
NWD THRU THE REGION. MDT CONFIDENCE.
FRI AND FRI NIGHT...PRIMARILY VFR DURING THE DAY AND SOME MVFR
CONDS AT NIGHT. MDT-HIGH CONFIDENCE.
SAT...OCCASIONAL MVFR TO BRIEFLY IFR CONDITIONS IN SCATTERED
SHOWERS AND THUNDERSTORMS. MDT CONFIDENCE
SUN-SUN NIGHT...VFR. HIGH CONFIDENCE.
MON...MAINLY VFR. PSBL AFTN SHWRS/TSTMS THAT CUD LWR VSBYS/CIGS.
LOW-MDT CONFIDENCE.
&&
.MARINE...
CONDITIONS ON THE WATERS WILL REMAIN BELOW SMALL CRAFT CRITERIA
THROUGH THURSDAY. THERE MAY BE A FEW SCT TSTMS LATE TONIGHT AND
THURSDAY. WINDS LIGHT TRENDING EASTERLY WITH TIME THRU THURSDAY.
OUTLOOK...
SUB SCA CONDS ARE EXPECTED THU NIGHT THRU FRI. FOG MAY BE THE
GREATER CONCERN, ESPECIALLY THURSDAY NIGHT. WITH A VEERING OF
WINDS TOWARD THE SOUTH, THE CONCERN MAY MOVE OUT OF OUR AREA BY
FRIDAY NIGHT.
SEAS INCREASE OVER THE WEEKEND, BUT WE ARE PLAYING IT A BIT MORE
CONSERVATIVE DUE TO SWLY FLOW...BUT THERE IS SOME SCA POTENTIAL
THERE.
A GREATER SCA POTENTIAL OCCURS EARLY NEXT WEEK IN ADVANCE OF THE
NEXT SYS, BUT THERE ARE STILL SOME TIMING ISSUES WRT TO THIS SYS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NIERENBERG
NEAR TERM...DRAG/O`HARA 502
SHORT TERM...O`HARA 502
LONG TERM...NIERENBERG
AVIATION...DRAG/NIERENBERG/O`HARA 502
MARINE...DRAG/NIERENBERG/O`HARA 502
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1042 AM EDT WED MAY 7 2014
.SYNOPSIS...
A HIGH PRESSURE RIDGE OVER THE FORECAST AREA WILL EASE OFFSHORE
LATER TODAY. A WARM FRONT OVER THE OHIO VALLEY AND CAROLINAS WILL
SLOWLY MOVE NORTHEAST AND PASS THROUGH THE FORECAST AREA AROUND
FRIDAY. A WEAK COLD FRONT IS FORECAST TO CROSS THE AREA LATE
SATURDAY OR EARLY SUNDAY AND THEN STALL JUST SOUTH OF THE AREA.
THIS FRONT IS THEN EXPECTED TO REVERSE COURSE AND START MOVING
NORTHWARD THROUGH OUR REGION AGAIN ON MONDAY AND TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A RIDGE OF HIGH PRESSURE ACROSS THE REGION WILL WEAKEN TODAY WHILE
A WARM FRONT MOVES NORTH/EAST FROM THE OHIO VALLEY.
AN AREA OF TSTMS ASSOC WITH A SHORT WAVE MOVING SE ACROSS WRN MD/S
CENT PA WILL CONTINUE TO MOVE SE AS PER THE RECENT HRRR WHICH HAS
A GOOD HANDLE ON IT. THESE SHOWERS WILL ARRIVE ACROSS THE DELMARVA
AREAS EARLY THIS AFTERNOON...SO POPS ACROSS THESE AREAS HAVE BEEN
INCREASED ON THE MOST RECENT ESTF.
WE USED A BLEND OF MAV/MET MOS AND MOS GUIDE FOR DAYTIME HIGHS. WITH
THE THICKENING CLOUD COVER DURING THE DAY, HIGHS ARE FORECAST TO BE
A COUPLE OF DEGREES BELOW NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
AS THE AFOREMENTIONED HIGH PRESSURE CONTINUES TO RECEDE AND SHIFT
EASTWARD OFF THE COAST, THE WARM FRONT WILL PUSH CLOSER TO THE AREA
OVERNIGHT. A COUPLE OF SHORT WAVE/VORT MAXES ARE FORECAST TO
TRAVERSE THE AREA OVERNIGHT, WHICH COMBINED WITH THE AVAILABLE
MOISTURE IS EXPECTED TO ENHANCE SHOWER ACTIVITY ACROSS THE AREA.
THERE IS NOT MUCH INSTABILITY, BUT WE WILL KEEP THE CHANCE OF
THUNDERSTORMS IN THE FORECAST FOR NOW AS THERE IS SOME WEAK ELEVATED
INSTABILITY. ALSO, TOTAL TOTALS INCH UP TO THE MID-UPPER 40S AND
K-INDEX VALUES CLIMB INTO THE MID-UPPER 20S.
WE USED A BLEND OF MAV/MET MOS AND MOS GUIDE FOR OVERNIGHT LOWS
WHICH KEEPS EVERYONE WITHIN A DEGREE OR TWO OF NORMAL.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
NEITHER DOMESTIC MODEL`S INITIALIZATION IN THE MIDWEST LOOKED THAT
GRAND AND THE GFS IS ALREADY WAY TOO HOT WITH ITS QPF FIELDS IN ITS
FIRST SIX HOURS. IF ANYTHING, THE GENERAL MODELING CONSENSUS HAS A
SOUTHWARD BIAS ON ONGOING MIDWEST CONVECTION. FORECAST CONFIDENCE IS
REDUCED BY WHAT LOOKS LIKE FEEDBACK VORT MAXES, ESPECIALLY ON THE
GFS. WHETHER REALISTIC OR NOT, A DP/DT ON THEM THU AND FRI SHOW VERY
LITTLE RUN TO RUN CONTINUITY. ADJUSTMENTS TO THE LONG TERM WILL BE A
BLEND OF NON-GFS MODELS WITH WPC GUIDANCE AND CONTINUITY. GREATEST
EMPHASIS ON POPS REMAINS EARLY THURSDAY AND SATURDAY.
WE PREFER THE MORE NORTHERN MODELING SOLUTIONS TO START OUR HIGHEST
PCPN CHANCES ON THURSDAY MORNING. AS THE MORNING AND AFTERNOON
PROGRESSES, PCPN CHANCES ARE EXPECTED TO BE LESS AS THE TRIGGERING
SHORT WAVE MOVES OFFSHORE AND FORECAST MOISTURE ABOVE 925MB
DECREASES. FORECAST UNCERTAINTY WITH THE ONSHORE FLOW IS HOW MUCH
CLEARING WILL OCCUR AS THERE WILL BE AN INVERSION. ONE WOULD THINK
THAT THE MAY SUN WILL HAVE SOME EFFECT. LEAST CONFIDENCE THOUGH IS
NORTHEAST WITH GREATEST CONFIDENCE OVER DELMARVA. WIDE RANGE IN
MAX TEMPS ACROSS OUR CWA REFLECT THIS. WE DIDN`T CHANGE THEM MUCH
FROM CONTINUITY.
ANOTHER MID LEVEL WAA SURGE (SOME FGEN AND QVEC FORCING SHOWING UP
IN THE FIELDS ALSO) IS FORECAST FOR THURSDAY NIGHT. THIS ONE HAS
MORE ELEVATED CONVECTIVE INSTABILITY THAN TONIGHT, BUT RIGHT NOW
IS NOT COUPLED WITH AN ATTENDANT SHORT WAVE. OVERALL WEAK FLOW
ALOFT AND NO PREDICTED LLJ. POPS THUS WERE KEPT BLO LIKELY LEVELS.
IN ADDITION, THE CONTINUING ONSHORE FLOW WITH DEW POINT TEMPERATURES
RISING ABOVE THE WATER TEMPERATURES INCREASES THE CHANCES FOR
MARINE FOG ADVECTING INLAND. WHILE POSSIBLE, WE MIGHT ALSO HAVE
SOME DRIZZLE WHICH WOULD MAKE FOR AN OXYMORONIC METEOROLOGICAL
PAIRING, DRIZZLE CAUSED BY THE STABLE TRAPPING OF MOISTURE BELOW
THE FRONTAL INVERSION, BUT AN UNSTABLE AIR MASS ABOVE THE
INVERSION CAPABLE OF TRIGGERING THUNDERSTORMS.
ON FRIDAY, THE WARM FRONT IS PREDICTED TO MAKE MORE NORTHWARD
PROGRESS AS THE 500MB RIDGE AXIS EASES TO THE EAST. RELATIVELY DRY
AIR ONCE AGAIN IS PREDICTED TO PASS OVER OUR CWA, SO THE PCPN
CHANCES ONCE AGAIN SHOULD DECREASE DURING THE MIDDLE OF THE DAY WITH
A SLIGHT UPTICK IN CHANCES NORTHWEST LATE IN THE DAY. WHILE ON
THURSDAY WE MIGHT BE TOO WARM WITH MAX TEMPS, FRIDAY WE MIGHT BE TOO
LOW, ESPECIALLY DELMARVA.
FRIDAY NIGHT WE INCREASE THE POPS AGAIN AS THE COLD FRONT
APPROACHES. SATURDAY POTENTIALLY COULD HAVE STRONG THUNDERSTORMS
AS THE COLD FRONT COMES CLOSER. THE FORECAST WIND FIELD (LLJ AND
JET ALF COUPLET) SURE DO LOOK BETTER AND THE EFFECTIVE PREDICTED
BULK SHEAR IS MORE ROBUST. THE LACK OF A LEE SIDE TROF FORMING
BACKING THE WINDS FURTHER TO THE SOUTH WOULD BE THE LIMITING
FACTOR TO COVERAGE. DONT BELIEVE CLOUDS OR TOO LOW TEMPS WILL BE
THE WET BLANKET. FOR NOW, WE MAINTAIN INCREASINGLY HIGHER POPS
WITH GREATEST CHANCES WEST. WE ARE DEEP IN THE SW FLOW BY
SATURDAY, SO WE ARE PRETTY CONFIDENT WE WILL REACH OUR FORECAST
MAX TEMPS.
THE LATEST ECMWF AND GFS RUNS ARE MORE OPTIMISTIC ABOUT THE COLD
FRONT CLEARING OUR CWA ON MOTHER`S DAY AND WE LOWERED POPS AND
REMOVED THE MENTION OF THUNDER. THE AIR MASS BEHIND THE COLD FRONT
IS NOT THAT MUCH COOLER, NOT MUCH OF A DROP OFF IN TEMPS. STILL
ABOVE NORMAL.
WHETHER ITS THE AFOREMENTIONED FRONT BACKING TO THE NORTH AGAIN, OR
ANOTHER FRONT APPROACHING FROM THE WEST. BOTH INCREASE OUR
CHANCES FOR SHOWERS AND THUNDERSTORMS ON MONDAY AND TUESDAY.
TEMPERATURES THOUGH STILL LOOK PRETTY, PRETTY WARM FOR THE START OF
THE WORK WEEK.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS ARE EXPECTED TO REMAIN ACROSS THE TAF SITES FOR TODAY
INTO THE EARLY PART OF THE EVENING, ALTHOUGH CLOUDS WILL BE
THICKENING AND LOWERING THROUGH THE DAY. THERE COULD BE SOME
SCATTERED SHOWERS LATE IN THE DAY, BUT THEY ARE NOT EXPECTED TO
REDUCE CIGS/VSBYS.
AS WE GO INTO LATE EVENING HOURS AND INTO THE OVERNIGHT HOURS,
CONDITIONS ARE EXPECTED TO LOWER TO MVFR, AND EVENTUALLY IFR AS AN
AREA OF SHOWERS MOVES INTO THE AREA. THERE IS A SMALL CHANCE OF
THUNDERSTORMS, BUT WE WILL KEEP THEM OUT OF THE TAFS FOR NOW SINCE
CONFIDENCE IS NOT VERY HIGH ON THEM ACTUALLY OCCURRING.
LIGHT WINDS EARLY THIS MORNING, MOSTLY FROM THE NORTHEAST, WILL
BECOME MORE SOUTHEASTERLY OR SOUTHERLY THIS AFTERNOON. WINDS WILL
SWITCH BACK TO THE SOUTHEAST THEN EAST LATER THIS EVENING AND
OVERNIGHT.
OUTLOOK...
THURSDAY AND THURSDAY NIGHT...MVFR CONDITIONS AT TIMES DUE TO
SHOWERS AND THUNDERSTORMS AS WELL AS LOWER CLOUDS AND FOG AT
NIGHT.
FRIDAY AND FRIDAY NIGHT...PRIMARILY VFR DURING THE DAY AND SOME MVFR
CONDITIONS AT NIGHT.
SATURDAY...OCCASIONALLY MVFR TO BRIEFLY IFR CONDITIONS IN SCATTERED
SHOWERS AND THUNDERSTORMS.
SUNDAY...PREDOMINATELY VFR.
&&
.MARINE...
SUB-ADVISORY CONDITIONS WILL PREVAIL ACROSS THE WATERS THROUGH TODAY
AND TONIGHT AS HIGH PRESSURE THAT HAS BEEN OVER THE AREA RECEDES AND
LIFTS TO THE NORTHEAST, ALTHOUGH WINDS MAY PERIODICALLY GUST AROUND
15-20 KNOTS.
OUTLOOK...
SUB SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED FOR THE NEXT
SEVERAL DAYS. FOG MAY BE THE GREATER CONCERN, ESPECIALLY THURSDAY
NIGHT WHEN THE SREF IS INDICATING A FOG BANK FORMING OVER OUR
ATLANTIC WATERS. WITH A VEERING OF WINDS TOWARD THE SOUTH, THE
CONCERN MAY MOVE OUT OF OUR AREA BY FRIDAY NIGHT.
WE CONTINUE TO BE MORE CONSERVATIVE THAN WAVE WATCH SEAS
WITH THE SW FLOW PRECEDING THE NEXT COLD FRONT ON THE WEEKEND AND
THE POST FRONTAL SFC WINDS ARE RELATIVELY WEAK.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...AMC/GIGI
NEAR TERM...ROBERTSON/PO
SHORT TERM...ROBERTSON
LONG TERM...GIGI
AVIATION...AMC/GIGI/ROBERTSON
MARINE...AMC/GIGI/ROBERTSON
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
209 PM EDT WED MAY 7 2014
.SYNOPSIS...
UPPER-LEVEL RIDGING AS WELL AS SURFACE HIGH PRESSURE WILL REMAIN
OVER THE REGION THROUGH FRIDAY. THE RIDGE WILL WEAKEN SATURDAY
AS A DISSIPATING FRONTAL SYSTEM MOVES INTO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE PRESSURE RIDGE EXTENDING INTO THE FORECAST AREA FROM THE
ATLANTIC WILL MAINTAIN THE DRY CONDITIONS. SATELLITE TRENDS
SUPPORT MOSTLY CLEAR SKIES. THE TEMPERATURE GUIDANCE WAS CONSISTENT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
SURFACE HIGH PRESSURE WILL CONTINUE TO RIDGE INTO THE FORECAST
AREA FROM THE ATLANTIC THROUGH FRIDAY NIGHT. ALOFT...THE MODELS
INDICATE THE RIDGE WILL SHIFT OFF THE COAST FRIDAY. THE GUIDANCE
TEMPERATURES WERE CONSISTENT...BUT THE HIGH TEMPERATURE GUIDANCE
MAY BE A LITTLE TOO COOL BASED ON RECENT VERIFICATION...DRY
CONDITIONS...AND UPPER RIDGE. IT MAY BE SLIGHTLY COOLER FRIDAY AS
SOME MID- AND HIGH-LEVEL CLOUDS MAY SPREAD INTO THE AREA IN THE
SOUTHWESTERLY FLOW.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
THE MODELS SHOW SOME MOISTURE ASSOCIATED WITH THE REMNANTS OF A
FRONT IN THE FORECAST AREA EARLY IN THE MEDIUM-RANGE PERIOD. A
COLD FRONT MAY MOVE INTO THE AREA LATE IN THE PERIOD. THE GFS...
ECMWF...AND EKD MOS HAVE BEEN TRENDING LOWER WITH THE POPS. THE
LATEST GUIDANCE HAS POPS OF 20 TO 30 PERCENT. THE PATTERN SUPPORTS
TEMPERATURES A LITTLE ABOVE NORMAL DURING THE PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
MODERATE HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THE TAF PERIOD.
HIGH PRESSURE OVER THE WESTERN ATLANTIC WILL CONTINUE CONTROL THE
WEATHER. THE AIR MASS WILL REMAIN RELATIVELY DRY WITH LITTLE IN THE
WAY OF CLOUDS. WINDS WILL BE SOUTHWEST TO WEST 5 TO 10 KNOTS WITH
OCCASIONAL GUST UP TO 18 KTS THROUGH THE AFTERNOON. LIGHT AND
VARIABLE WILL RETURN THIS EVENING AS AN INVERSION DEVELOPS.
THE NAM AND RUC MODELS INDICATED INCREASING LOW LEVEL MOISTURE FOR
THE POSSIBILITY OF FOG OR STRATUS DEVELOPMENT AT AGS AND OGB 08/09Z
THROUGH 08/12Z. THE SREF MODEL KEPT CIG/VSBY RESTRICTIONS SOUTHEAST
OF THE TAF SITES. GIVEN A DRY AIR MASS AND THE DEVELOPMENT OF A LOW
LEVEL JET FOR BOUNDARY LAYER MIXING AS WELL AS VERY LOW
CONFIDENCE...WILL NOT INCLUDE FOG OVERNIGHT.
.EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS TO AVIATION
EXPECTED THURSDAY THROUGH SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS POCATELLO ID
900 AM MDT WED MAY 7 2014
.UPDATE...PRECIPITATION CONTINUES THIS MORNING WITH SNOW LEVELS
RIGHT AROUND 5000 FEET. ACCUMULATIONS THUS FAR HAVE BEEN NO MORE
THAN A DUSTING BUT STILL EXPECTING SNOW LEVELS TO RISE THROUGH THE
DAY TODAY TO AROUND 7000 FEET. NAM AND HRRR BOTH ARE CONTINUING TO
SHOW FAVORED CONVECTION IN THE SOUTH AND EAST HIGHLANDS WITH
ISOLATED THUNDERSTORMS POSSIBLE. DEPENDING ON THE AMOUNT OF
CLEARING IN THE CENTRAL MOUNTAINS...CONVECTION IS POSSIBLE IN
THOSE AREAS AS WELL. WINDS NEAR AMERICAN FALLS RESERVOIR ARE STILL
NORTHEAST AND STRONG ENOUGH TO SUPPORT THE LAKE WIND ADVISORY THAT
IS IN EFFECT. STILL LOOKS LIKE A WIND SHIFT WILL HAPPEN EARLY
AFTERNOON IN THAT AREA SO EXPIRING THE LAKE WIND AROUND 2 PM STILL
LOOKS GOOD. ALL GRIDS STILL LOOK ON TRACK SO DID NOT MAKE ANY
CHANGES. EP
&&
.PREV DISCUSSION... /ISSUED 310 AM MDT WED MAY 7 2014/
SHORT TERM...TODAY THROUGH FRIDAY NIGHT. THE CURRENT SATELLITE
IMAGERY WAS SHOWING AN UPPER LOW ROTATING INTO SW UTAH WHILE
ASSOCIATED MOISTURE AND SHOWERS LIFTED NORTH INTO SE IDAHO. MODELS
SUGGEST THAT THE UPPER LOW WILL LIFT NNE TODAY THROUGH UTAH LEAVING
SE IDAHO UNDER A MOIST-UNSTABLE AIRMASS. AN INVERTED SURFACE LOW
EXTENDING FROM COLORADO NE INTO SE IDAHO WILL SUPPORT NORTH WINDS
THROUGHOUT THE UPPER VALLEY TODAY WHILE WEST WINDS SPREAD EAST
THROUGH THE ERN MAGIC VALLEY. TOUGH CALL TODAY ON HOW LONG AND/OR
HOW STRONG THE NORTH WINDS WILL BE ACROSS THE AMERICAN FALLS
RESERVOIR. NEARBY OBS ARE CURRENTLY SHOWING NE WINDS NEAR ADVISORY
LEVELS...THUS WILL PUSH A LAKE WIND ADV OUT THE DOOR WITH THE
MORNING PACKAGE. THE LOW PASSES EAST OVERNIGHT WITH DRIER CONDITIONS
SPREADING INTO THE REGION FROM THE WEST. A NEGATIVELY TILTED PAC
TROUGH SWINGS INTO THE NW STATES THURSDAY AFTERNOON...SPREADING EAST
ACROSS SRN IDAHO THURSDAY NIGHT/FRIDAY MORNING WITH ANOTHER ROUND OF
WIDESPREAD PRECIPITATION AND BREEZY/WINDY CONDITIONS ANTICIPATED FOR
SE IDAHO. HUSTON
LONG TERM...SATURDAY THROUGH TUESDAY. THE 7/00Z RUN OF THE GFS HAS
INCREASED THE WAVE AMPLITUDE AND OVERALL MOVED CLOSER IN LINE TO THE
ECMWF WHICH TAKES A LOW NEAR THE OREGON COAST SATURDAY MORNING AND
MOVES IT OVER UTAH BY SUNDAY MORNING. KEEPING CHANCE POPS IN THE
MOUNTAINS SATURDAY AND SATURDAY NIGHT APPEARS TO BE A GOOD MOVE AND
MAY NEED TO BE INCREASED SOME MORE. THAT LEAVES A HIGH PRESSURE
RIDGE DEVELOPING NEAR THE WEST COAST BY SUNDAY AND DECREASING
SHOWERS IN SOUTHEAST IDAHO SUNDAY EVENING. THE LATEST ECMWF IS NOT
WITHOUT CHANGES. THERE ARE TWO MINOR DISTURBANCE CROSSING NORTHERN
IDAHO...ONE MONDAY AND ANOTHER TUESDAY THAT RESULT IN A FLATTER
RIDGE AND TAKING A LITTLE EDGE OFF THE WARM UP FOR EARLY NEXT WEEK.
RS
AVIATION...FOR KBYI...KPIH AND KIDA MORE SCATTERED RAIN SHOWERS ARE
IN ORDER BETWEEN 10Z AND 19Z TODAY AS THE CIRCULATION IN NORTHWEST
UTAH MOVES EAST TO NORTHEAST. THE INSTABILITY IS NOT AS STRONG AS
YESTERDAY BUT CANT RULE OUT AN ISOLATED THUNDERSTORM IN THE CARIBOU
HIGHLANDS AND BEAR LAKE AREA THIS AFTERNOON. MVFR CEILINGS WITH THE
SHOWERS A GOOD BET. HIGH PRESSURE MOVES IN TONIGHT AND THURSDAY
PROVIDING A BREAK IN THE WEATHER UNTIL A COLD FRONT COMES THROUGH
FRIDAY MORNING. RS
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY UNTIL 2 PM MDT THIS AFTERNOON IDZ021.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1013 PM CDT THU MAY 8 2014
.DISCUSSION...
818 PM CDT
FOR EVENING UPDATE...
SHOWER/THUNDERSTORM COVERAGE AND INTENSITY PLAYING OUT AS EARLIER
DISCUSSED...WITH CONVECTION GENERALLY STRUGGLING AS IT MOVES INTO
NORTH CENTRAL IL. LOSS OF DIURNAL HEATING AND ASSOCIATED LOW-LEVEL
INSTABILITY HAS DECREASED MARGINAL SEVERE THREAT...THOUGH WILL
CONTINUE TO MONITOR CELLS MOVING OUT OF WEST-CENTRAL IL FOR ANY
STRONGER CORES THAT MIGHT STILL BE ABLE TO PRODUCE SOME SMALL HAIL
OR MARGINAL WIND GUSTS. OTHERWISE...AREA OF RAIN AND EMBEDDED
THUNDER OVER EASTERN MISSOURI IS EXPECTED TO SHIFT NORTHEAST INTO
OUR REGION AFTER MIDNIGHT IN ASSOCIATION WITH MID-LEVEL SHORT WAVE
AND INCREASING MOISTURE TRANSPORT ON 40-50 KT 850 HPA JET. REGIONAL
RADAR MOSAIC AND ORIENTATION OF MOIST PLUME OVERNIGHT SUGGESTS FOCUS
WILL BE IN OUR CENTRAL/SOUTHEASTERN CWA...THOUGH LARGER SCALE HEIGHT
FALLS AHEAD OF DEEP UPPER TROUGH LIFTING INTO THE UPPER MIDWEST AND
APPROACH OF SURFACE COLD FRONT TOWARD MORNING SHOULD BOTH WORK TO
INCREASE COVERAGE OF SHOWERS/THUNDERSTORMS OVER NORTHWESTERN CWA AS
WELL PRE-DAWN FRIDAY MORNING. EXTENT OF CLOUDINESS AND MORNING
PRECIP RAISES QUESTIONS ABOUT EXTENT OF THUNDERSTORM/SEVERE THREAT
FRIDAY AFTERNOON...THOUGH FRONT SLOWS UP IN THE AFTERNOON ACROSS
NORTHWEST IN/EAST CENTRAL IL AND INDICATES BEST CHANCES FOR
PRECIP/THUNDER FRIDAY AFTERNOON MAINLY ACROSS ABOUT THE SOUTHEAST
1/3 OF THE FA.
HAVE MADE SOME ADJUSTMENTS TO HOURLY POP/WX GRIDS TO PROVIDE A
LITTLE MORE DETAIL IN TIMING AND PLACEMENT OF EXPECTED ROUNDS OF
PRECIP THROUGH FRIDAY...WITH POPS LOWERED FROM THE WEST/NORTHWEST
BEHIND THE FRONT ON FRIDAY AND GRADIENT FROM NO POPS NORTHWEST TO
LIKELY POPS IN OUR SOUTHEAST TIGHTENED UP. HAVE ALSO FOCUSED MENTION
OF LOCALLY HEAVY RAINFALL FOR LATE TONIGHT/EARLY FRIDAY MORNING OVER
CENTRAL/SOUTHEAST COUNTIES AS INDICATED ABOVE.
UPDATED GRIDS...ZFP/LFP ALL ALREADY AVAILABLE.
RATZER
//PREV DISCUSSION...
312 PM CDT
MAIN CONCERN FOR THE AREA REMAINS THE CHANCES FOR THUNDERSTORMS.
FOR THE REMAINDER OF THE AFTERNOON AND INTO EARLY THIS
EVENING...CONDITIONS SHOULD REMAIN QUIET AS THE AREA REMAINS IN A
CAPPED WARM SECTOR. THE WARM FRONT HAS PUSHED WELL NO THE NORTH
WHILE A COLD FRONT IS WELL TO THE WEST...EXTENDING FROM DEEPENING
LOW PRESSURE OVER WRN IA/ERN NE SOUTHWEST THROUGH CNTRL KS/WRN OK.
AS LONG AS THE ENVIRONMENT OVER THE LOCAL AREA REMAINS CAPPED...THE
CHANCES FOR ANY PCPN WILL BE LIMITED. CURRENTLY...THE PRIMARY
THUNDERSTORM THREAT IS INVOF THE COLD FRONT/SFC LOW WHERE SPC HAS
ISSUED THE FIRST WATCH OF THE DAY OVER WRN IA/NWRN MN. AS SFC
TEMPERATURES RISE INTO THE UPPER 80S ANTICIPATE THAT THE CAP WILL
ERODE WITH TIME THROUGH THE LATE AFTERNOON AND EARLY EVENING HOURS.
HOWEVER...SOME DRIER AIR IS MIXING DOWN TO THE SURFACE THIS AND SFC
DEWPOINTS HAVE DROPPED INTO THE UPPER 50S...BUT EXPECT THAT
DEWPOINTS WILL REBOUND BACK INTO THE 60S THIS EVENING. SFC BASED
INSTABILITY WILL BE ON THE INCREASE WHILE THE SFC LOW TRACKS TO THE
WRN GREAT LAKES OVERNIGHT TONIGHT AND THE COLD FRONT PUSHES INTO
NWRN IL. STRONG WARM ADVECTION IN THE WARM SECTOR AND LOW LEVEL
FORCING WITH THE COLD FRONT COMBINED WITH UPPER LEVEL FORCING AS THE
REGION WILL BE UNDER THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET
STREAM...WILL PROVIDE THE FOCUS FOR THE DEVELOPMENT OF STRONG
TO...POTENTIALLY...SEVERE THUNDERSTORMS ACROSS NRN IL THROUGH THE
NIGHT. WHILE THERE MAY STILL BE A CHANCE FOR DISCRETE SUPERCELLS TO
DEVELOP AHEAD OF THE COLD FRONT...THE MORE LIKELY CONVECTIVE MODE
TONIGHT IS SHAPING UP TO BE MORE LINEAR...AS THE CONVECTIVE ACTIVITY
TO THE WEST CONSOLIDATES INTO LINES. THUS...THE MORE LIKELY SEVERE
THREAT SHOULD BE LARGE HAIL AND STRONG DAMAGING WINDS. HEAVY
RAINFALL WILL ALSO BE A CONCERN WITH THE THUNDERSTORMS TONIGHT WITH
PWATS FORECAST TO BE ARND 1.7 INCHES. HOWEVER...WITH THE FRONTAL
SYSTEM STEADILY PROGRESSIVE TO THE EAST...DO NOT ANTICIPATE
SIGNIFICANT ECHO TRAINING. SO...LOCALLY HEAVY RAINFALL MAY LEAD TO
URBAN FLOODING CONCERNS...DO NOT ANTICIPATE A WIDESPREAD FLASH FLOOD
THREAT. THE SHORT RANGE MODEL GUIDANCE IS RELATIVELY CONSISTENT ON
THE STEADY PROGRESSION OF THE COLD FRONT...CLEARING THE ERN PORTIONS
OF THE CWA BY EARLY TOMORROW AFTERNOON...THOUGH SOME LINGERING
SHOWERS ARE POSSIBLE INTO THE LATE AFTERNOON HOURS...ESPECIALLY FOR
THE NWRN INDIANA COUNTIES.
FOLLOWING THE PASSAGE OF THE COLD FRONT...A PERIOD OF RELATIVE CALM
IS EXPECTED FOR FRIDAY NIGHT AND SATURDAY AS WEAK HIGH PRESSURE
SPREADS OVER THE MIDWEST. TEMPERATURES FOR FRIDAY AND SATURDAY
SHOULD MODERATE INTO THE LOWER TO MIDDLE 70S. BRISK SWLY FLOW
PERSISTING ON FRIDAY SHOULD ALLOW THE WARMER AIR TO PENETRATE ALL
THE WAY TO THE LAKE FRONT...BUT FOR SATURDAY...A WEAK SFC PRESSURE
GRADIENT AND RELATIVELY LIGHT WINDS SHOULD ALLOW FOR A LAKE BREEZE
TO DEVELOP. WITH ANOTHER LOW DEVELOPING OVER THE CNTRL PLAINS AND
HIGH PRESSURE OVER THE SERN CONUS...SFC WINDS SHOULD BE PREVAILING
SLY TO SWLY...SO...THE LAKE BREEZE SHOULD ASSUME A NW-SE ORIENTATION
AND LIKELY ONLY MOVE INLAND FROM CHICAGO NORTHWARD. WHILE MUCH OF
THE CWA ENJOYS TEMPERATURES BACK IN THE MIDDLE 70S ON SATURDAY...THE
LAKEFRONT LOCATIONS FROM CHICAGO TO WAUKEGAN SHOULD SEE HIGHS ONLY
IN THE LOWER TO MIDDLE 60S.
THE NEXT SIGNIFICANT CHANCE FOR PCPN WILL COME BY SATURDAY EVENING
AS THE AFOREMENTIONED LOW PRESSURE SYSTEM TRACKS THROUGH THE UPPER
MIDWEST AND DRAGGING ANOTHER COLD FRONT ACROSS THE AREA. THIS
SYSTEM IS NOT LOOKING QUITE AS DYNAMIC AS THE SYSTEM EXPECTED THIS
EVENING...SO...THE CHANCES FOR MORE SEVERE WEATHER ARE LOW. A SRN
STREAM SYSTEM LIFTING OUT OF THE SRN ROCKIES BY SATURDAY NIGHT WILL
DEVELOP A WAVE ON THE SRN END OF THE FRONT. THIS WAVE IS FORECAST
TO RIPPLE ALONG THE BOUNDARY TO THE NORTHEAST...WHICH WILL HELP TO
SLOW THE OVERALL PROGRESSION OF THE SYSTEM AND A STRUNG OUT FRONTAL
SYSTEM IS EXPECTED TO EXTEND FROM THE RED RIVER VALLEY INTO THE WRN
GREAT LAKES BY SUNDAY NIGHT. WITH THE FRONT NOT EXPECTED TO PUSH
EAST OF THE AREA UNTIL TUESDAY MORNING...THERE WILL BE AN EXTENDED
CHANCE FOR SHOWERS AND THUNDERSTORMS FROM LATE SATURDAY NIGHT
THROUGH TUESDAY MORNING.
FOR THE LONGER RANGE FORECAST PERIOD...FROM TUESDAY THROUGH
THURSDAY...FOLLOWING THE PASSAGE OF THE COLD FRONT AND THE
ASSOCIATED LOW...THERE WILL STILL BE LINGERING CHANCES FOR SHOWERS
WITH A SERIES OF NRN STREAM SHORT WAVES DROPPING OUT OF CANADA RIGHT
ON THE HEELS OF THE EXITING SYSTEM. WITH SOME UNCERTAINTY TO THE
EXACT TIMING OF THIS SERIES OF SHORTWAVES...WILL CARRY AT LEAST
CHANCE POPS THROUGH THE EXTENDED PERIOD. WITH THE TRAIN OF
SHORTWAVES CARVING OUT A LONG WAVE TROUGH OVER THE GREAT LAKES AND
MIDWEST...TEMPERATURES FOR TUESDAY THROUGH THURSDAY SHOULD BE BACK
TO WELL BELOW NORMAL. HIGHS FOR TUESDAY THROUGH THURSDAY ARE
EXPECTED TO BE IN THE LOWER TO MIDDLE 60S WITH EVEN SOME UPPER 50S
POSSIBLE ALONG THE LAKEFRONT. OVERNIGHT LOWS THROUGH THE EXTENDED
PERIOD SHOULD ONLY BE IN THE 40S.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* GUSTY SOUTHERLY WINDS THIS EVENING.
* A PERIOD OR TWO OF SHRA/PSBL ISOLATED TSRA LATE THIS EVENING
THROUGH EARLY FRIDAY MORNING...WITH A CHANCE FOR ADDITIONAL
SHRA/TSRA THROUGH MID FRIDAY MORNING.
* MVFR CEILINGS FRIDAY MORNING.
RC
//DISCUSSION...UPDATED 00Z...
LOW PRESSURE IS CENTERED NEAR THE MN/IA BORDER EAST OF FSD EARLY
THIS EVENING...WITH A COLD FRONT TRAILING TO ITS SOUTH. GUSTY
SOUTH-SOUTHWEST WINDS CONTINUE AT ALL TAF SITES WHICH ARE
ENTRENCHED IN THE WARM SECTOR OF THE STORM SYSTEM. AN UPPER
DISTURBANCE IN ADVANCE OF THE SYSTEM IS RESULTING IN SCT TSRA FROM
NORTHEAST MO TO NORTHWEST/NORTH CENTRAL IL...WITH TSRA AT LEAST IN
THE VICINITY OF RFD FOR THE NEXT FEW HOURS. SCT SHRA/TSRA SHOULD
GRADUALLY DEVELOP TOWARD THE EASTERN TERMINALS LATER THIS EVENING
BUT BASED ON TRENDS HAVE PUSHED BACK TIMING A FEW HOURS. CLOSER
APPROACH OF COLD FRONT OVERNIGHT INTO EARLY FRIDAY SHOULD RESULT
IN ANOTHER ROUND OF SCT TO WIDESPREAD SHRA/TSRA. OVERALL DO NOT
HAVE HIGH CONFIDENCE IN PREVAILING TSRA AT ANY TAF SITE SO HAVE
BACKED OFF TO VICINITY MENTION BUT WILL AMEND AS NEEDED. THERE IS
UNCERTAINTY WITH IMPACT OF OVERNIGHT CONVECTION ON INSTABILITY
FRIDAY MORNING AND ALSO FOCUS SHOULD BE TRENDING MAINLY TO THE
SOUTHEAST OF THE EASTERN TERMINALS. FEEL THAT CHANCES FOR
ADDITIONAL THUNDER ARE LOW BUT NONZERO...AND HAVE COVERED
POTENTIAL WITH A VCSH MENTION.
OTHER CONCERN IS FOR A PERIOD OF MVFR CIGS FROM EARLY TO MID
MORNING FRIDAY. SUSPECT THAT GUIDANCE INDICATING LOW MVFR AND EVEN
IFR CIGS IS OVERDONE WITH LOW LEVEL MOISTURE SO HAVE MAINTAINED A
HIGH END MVFR CIG WHICH SHOULD SCATTER BY LATE MORNING. AS FRONTAL
TROUGH CROSSES THE TERMINALS...WINDS WILL VEER SOUTHWESTERLY AND
THEN WESTERLY WITH INCREASED SPEEDS/GUSTS THAT WILL LIKELY QUICKLY
DIMINISH WITH SUNSET FRIDAY EVENING AS WEAK HIGH PRESSURE SPREADS
OVER THE AREA.
RC
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH WITH WIND TRENDS.
* MEDIUM-HIGH IN SHRA OVERNIGHT...MEDIUM CONFIDENCE IN
TIMING...LOW IN VCTS/PREVAILING TSRA AT TERMINALS.
* LOW IN ADDITIONAL TSRA THROUGH MID FRIDAY MORNING.
* MEDIUM IN A PERIOD OF MVFR CIGS FRIDAY MORNING.
RC
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...DAYTIME VFR...LAKE BREEZE WIND SHIFT POSSIBLE.
SHRA/TSRA POSSIBLE OVERNIGHT.
SUNDAY...PERIODS OF SHRA/TSRA POSSIBLE. SOUTHERLY WINDS.
MONDAY...PERIODS OF SHRA/TSRA POSSIBLE. SOUTH TO SOUTHWEST WINDS.
TUESDAY AND WEDNESDAY...CHANCE SHRA.
RC
&&
.MARINE...
218 PM CDT
A WARM FRONT DRAPED ACROSS THE NORTHERN PART OF THE LAKE LATE THIS
AFTERNOON WILL SHIFT NORTH OF THE LAKE THIS EVENING...YIELDING
SOUTHERLY WINDS ACROSS THE ENTIRE LAKE. GUSTS AROUND 25 KT...AT
TIMES POSSIBLY REACHING 30 KT BRIEFLY...WILL CONTINUE ACROSS
ILLINOIS AND INDIANA NEAR SHORE AREAS THROUGH TONIGHT AND INTO
FRIDAY. STORMS LOOK LIKELY LATE TONIGHT INTO FRIDAY MORNING...A
FEW OF WHICH COULD BE GUSTY. AS THE LOW PRESSURE DRIVING THE
SOUTHERLY WINDS MOVES FROM IOWA THIS AFTERNOON THROUGH ONTARIO ON
FRIDAY IT WILL STEER A COLD FRONT OVER LAKE MICHIGAN ON FRIDAY
NIGHT. THIS FRONT WILL BE WEAKENING THOUGH AND ONLY BRIEFLY TURN
THE WINDS WEST-SOUTHWEST BEFORE TURNING BACK SOUTHERLY THIS
WEEKEND. THE NEXT AREA OF LOW PRESSURE WILL NEAR THE LAKE DURING
LATE SUNDAY INTO MONDAY.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 7 PM FRIDAY.
&&
$$
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
840 PM CDT Thu May 8 2014
.DISCUSSION...
ISSUED 835 PM CDT Thu May 8 2014
Convection continues to make slow progress over west central IL
this evening, now advancing along and just east of I-55. Had a
couple of reports of wind gusts of 50 to 60 mph with the storms
late this afternoon but those were few and far between. With the
loss of daytime heating, our instability parameters are not very
impressive across central IL this evening with CAPE values over
most of the area now down below 1000 j/kg. Short term models
suggest as low level jet increases to our southwest later this
evening, we should see more widespread rainfall across the
forecast area during the early morning hours along with mild
temperatures. Have already sent out an update to address the
storms moving into west central IL earlier this evening, but
will send out another update by 900 pm to address the current
thinking on the timing of the rain into eastern IL later this
evening.
Smith
&&
.AVIATION...
ISSUED 605 PM CDT Thu May 8 2014
Band of showers and thunderstorms will affect our western TAF
sites this evening with an overall increase in coverage later
tonight across the east which will gradually bring cigs to
MVFR category during the early morning hours. First band of
rain will stay along and west of I55 early this evening with
an increase in coverage to the east roughly after 03z. Once
the MVFR ceilings set in aftr 05z in the west and 08z in the
east, they are expected to hold over the area with rain and
isold thunder into the morning hours of Friday.
Next problem will be with the threat for redevelopment of showers
and thunderstorms along a weakening cold front tomorrow afternoon
and evening. For now will include a VCTS group for DEC and CMI and
see how the overnight precip affects coverage of rain tomorrow
afternoon. Surface winds will continue from a southerly direction
at 12 to 17 kts tonight with an occasional gust up to 25 kts at
times this evening. Winds will veer more into a southwest to west
direction at 12 to 17 kts on Friday with gusts around 25 kts,
especially in the afternoon.
Smith
&&
.PREV DISCUSSION...
ISSUED 258 PM CDT Thu May 8 2014
Temperatures warming nicely across the forecast area today, with
gusty south-southwest winds and mainly some high clouds. Mostly in
the mid 80s, although some 90 degree temperatures reported at
Champaign and Rantoul at 2 pm. Convection developing as expected
west of the Mississippi River, with one cluster over
Minnesota/Iowa along the warm front, and the second developing
over western Missouri just ahead of the cold front. Both fronts
are tied into a surface low over northeast Nebraska.
Initial forecast concerns are with thunderstorm trends through
Friday including severe threat, followed by timing of
showers/storms for much of the first half of next week.
SHORT TERM...Tonight through Friday Night:
Latest mesoscale analysis showing CAPE`s of 1000-1500 J/kg over
the forecast area, with the cap eroding along the Mississippi
River. Latest HRRR has the storms reaching the Illinois River
valley by around 6 pm and I-57 toward 9-10 pm. Areas west of I-55
most likely to see any severe weather as the instability will be
decreasing by the time the storms make it further east. Hail/wind
remains the primary concern with the storms. Secondary line of
showers/storms immediately ahead of the front will begin to move
in after midnight, but think the severe threat will be be over by
that point.
Extent of overnight convection will dictate where the severe
threat is for Friday. Areas south of I-70 would be most likely as
the front comes in and with outflows from the earlier convection
around, but additional instability would likely have to come
during the afternoon in between periods of storms. Will mention
categorical PoP`s over 80% across the southeast third of the
forecast area through the day, with not the rain not fully moving
out of the southeast CWA until closer to midnight. Further west,
will largely go dry west of I-55 during the afternoon.
LONG TERM...Saturday through Thursday:
Short period of dry weather on tap for Saturday as a narrow ridge
axis slides by, but next wave will be approaching from the Plains.
Have added some slight chance PoP`s in the afternoon west of I-55,
but main period of convection will develop Saturday night. Will
introduce likely PoP`s late Saturday night across about the
northwest 2/3 of the forecast area, lingering into Sunday across
the north as remnants of an MCS move across the area.
The forecast from Sunday night into Monday night is more of a
challenge. The GFS is much faster than the ECMWF or Canadian
models by surging a cold front through the area Monday night,
while the latter models are close to 24 hours slower. This slower
solution would keep a good part of Sunday night and Monday dry.
This appears to be tied into phasing of the long wave trough across
the Rockies Sunday night, with the GFS featuring a more
progressive wave and the ECMWF cutting off a low over the northern
Dakotas for a time early next week. Am trending the blended model
grids on the slower side, but have not completely eliminated any
PoP`s Monday/Tuesday.
Deep upper trough over the central U.S. to provide a period of
cooler weather for the middle of the week. Will see highs only in
the 60s much of the Tuesday-Thursday period.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
709 PM CDT THU MAY 8 2014
.MESOSCALE DISCUSSION...549 PM CDT
ISOLATED-SCATTERED THUNDERSTORMS DEVELOPING OVER WESTERN IL LATE
THIS AFTERNOON EXPECTED TO CONTINUE TO SPREAD INTO NORTH CENTRAL
IL EARLY THIS EVENING. THESE CELLS APPEAR TO BE FOCUSED IN A
REGION OF WEAK LOW-LEVEL MOIST CONVERGENCE ALONG LEADING EDGE OF
SLIGHTLY HIGHER (LOW 60S) SFC DEW POINT TEMPS...AND IN RESPONSE TO
45-50 KT MID-LEVEL SPEED MAX ASSOCIATED WITH A MINOR-AMPLITUDE
SHORT WAVE LIFTING ACROSS MO-EASTERN IA. RAP/SPC MESOANALYSIS
INDICATES 1000-1500 J/KG MLCAPE AND 30-40 KT OF EFFECTIVE/6 KM
BULK SHEAR SUFFICIENT FOR ORGANIZED UPDRAFTS. A FEW CELLS HAVE
BRIEFLY DEVELOPED STRONG CORES ALOFT...PARTICULARLY THE STORM
CURRENTLY NORTH OF GALESBURG WHICH EARLIER HAD 50 DBZ REFLECTIVITY
AROUND 30 KFT...BUT RELATIVELY WARM PROFILE SUGGESTS LARGE HAIL
NOT A BIG THREAT GIVEN THE LACK OF STRONG STEEP MID-LEVEL LAPSE
RATES.
FARTHER EAST INTO OUR CWA...AND EAST OF MOISTURE DISCONTINUITY...SFC
DEW POINT TEMPS FALL OFF INTO THE MID-UPPER 50S. WHILE STORMS WILL
LIKELY CONTINUE TO DEVELOP NORTHEAST IN ASSOCIATION WITH APPROACHING
SHORT WAVE...THIS SUGGESTS THAT CONVECTION MAY STRUGGLE TO MAINTAIN
INTENSITY SEEN OVER WESTERN IL THIS AFTERNOON. LOW-LEVEL LAPSE RATES
ARE RATHER STEEP ACROSS OUR CWA (WITH DCAPE 1000+ J/KG PER RAP/SPC
ANALYSIS) IN SLIGHTLY DRIER WELL-MIXED BOUNDARY LAYER...THOUGH LOW
LEVEL LAPSE RATES SHOULD TEND TO DECREASE DIURNALLY AS WE
APPROACH/PASS SUNSET. THEREFORE...IT APPEARS THAT A RATHER MARGINAL
SEVERE THREAT EXISTS MAINLY FOR THE FAR WESTERN CWA COUNTIES (AND
PERHAPS MAINLY WESTERN PARTS OF OGLE/LEE COUNTIES) INTO EARLY
EVENING MAINLY FOR DAMAGING WIND GUSTS/MARGINAL HAIL IF ANY STRONGER
STORMS DEVELOP THAT FAR EAST.
OTHERWISE...ADDITIONAL SHOWERS AND THUNDERSTORMS EXPECTED LATER
TONIGHT AS UPPER TROUGH SLOWLY APPROACHES FROM THE WEST...AND MOIST
AXIS SHIFTS EAST AHEAD OF COLD FRONT TO OUR WEST. THREAT FROM THESE
STORMS APPEARS TO BE MAINLY LOCALLY HEAVY RAINFALL WITH 1.5"+
PRECIPITABLE MOISTURE AXIS DEVELOPS EAST AND 40-50 KT SOUTHWESTERLY
LOW LEVEL JET INCREASES MOISTURE TRANSPORT INTO THE REGION.
RATZER
&&
.DISCUSSION...
312 PM CDT
MAIN CONCERN FOR THE AREA REMAINS THE CHANCES FOR THUNDERSTORMS.
FOR THE REMAINDER OF THE AFTERNOON AND INTO EARLY THIS
EVENING...CONDITIONS SHOULD REMAIN QUIET AS THE AREA REMAINS IN A
CAPPED WARM SECTOR. THE WARM FRONT HAS PUSHED WELL NO THE NORTH
WHILE A COLD FRONT IS WELL TO THE WEST...EXTENDING FROM DEEPENING
LOW PRESSURE OVER WRN IA/ERN NE SOUTHWEST THROUGH CNTRL KS/WRN OK.
AS LONG AS THE ENVIRONMENT OVER THE LOCAL AREA REMAINS CAPPED...THE
CHANCES FOR ANY PCPN WILL BE LIMITED. CURRENTLY...THE PRIMARY
THUNDERSTORM THREAT IS INVOF THE COLD FRONT/SFC LOW WHERE SPC HAS
ISSUED THE FIRST WATCH OF THE DAY OVER WRN IA/NWRN MN. AS SFC
TEMPERATURES RISE INTO THE UPPER 80S ANTICIPATE THAT THE CAP WILL
ERODE WITH TIME THROUGH THE LATE AFTERNOON AND EARLY EVENING HOURS.
HOWEVER...SOME DRIER AIR IS MIXING DOWN TO THE SURFACE THIS AND SFC
DEWPOINTS HAVE DROPPED INTO THE UPPER 50S...BUT EXPECT THAT
DEWPOINTS WILL REBOUND BACK INTO THE 60S THIS EVENING. SFC BASED
INSTABILITY WILL BE ON THE INCREASE WHILE THE SFC LOW TRACKS TO THE
WRN GREAT LAKES OVERNIGHT TONIGHT AND THE COLD FRONT PUSHES INTO
NWRN IL. STRONG WARM ADVECTION IN THE WARM SECTOR AND LOW LEVEL
FORCING WITH THE COLD FRONT COMBINED WITH UPPER LEVEL FORCING AS THE
REGION WILL BE UNDER THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET
STREAM...WILL PROVIDE THE FOCUS FOR THE DEVELOPMENT OF STRONG
TO...POTENTIALLY...SEVERE THUNDERSTORMS ACROSS NRN IL THROUGH THE
NIGHT. WHILE THERE MAY STILL BE A CHANCE FOR DISCRETE SUPERCELLS TO
DEVELOP AHEAD OF THE COLD FRONT...THE MORE LIKELY CONVECTIVE MODE
TONIGHT IS SHAPING UP TO BE MORE LINEAR...AS THE CONVECTIVE ACTIVITY
TO THE WEST CONSOLIDATES INTO LINES. THUS...THE MORE LIKELY SEVERE
THREAT SHOULD BE LARGE HAIL AND STRONG DAMAGING WINDS. HEAVY
RAINFALL WILL ALSO BE A CONCERN WITH THE THUNDERSTORMS TONIGHT WITH
PWATS FORECAST TO BE ARND 1.7 INCHES. HOWEVER...WITH THE FRONTAL
SYSTEM STEADILY PROGRESSIVE TO THE EAST...DO NOT ANTICIPATE
SIGNIFICANT ECHO TRAINING. SO...LOCALLY HEAVY RAINFALL MAY LEAD TO
URBAN FLOODING CONCERNS...DO NOT ANTICIPATE A WIDESPREAD FLASH FLOOD
THREAT. THE SHORT RANGE MODEL GUIDANCE IS RELATIVELY CONSISTENT ON
THE STEADY PROGRESSION OF THE COLD FRONT...CLEARING THE ERN PORTIONS
OF THE CWA BY EARLY TOMORROW AFTERNOON...THOUGH SOME LINGERING
SHOWERS ARE POSSIBLE INTO THE LATE AFTERNOON HOURS...ESPECIALLY FOR
THE NWRN INDIANA COUNTIES.
FOLLOWING THE PASSAGE OF THE COLD FRONT...A PERIOD OF RELATIVE CALM
IS EXPECTED FOR FRIDAY NIGHT AND SATURDAY AS WEAK HIGH PRESSURE
SPREADS OVER THE MIDWEST. TEMPERATURES FOR FRIDAY AND SATURDAY
SHOULD MODERATE INTO THE LOWER TO MIDDLE 70S. BRISK SWLY FLOW
PERSISTING ON FRIDAY SHOULD ALLOW THE WARMER AIR TO PENETRATE ALL
THE WAY TO THE LAKE FRONT...BUT FOR SATURDAY...A WEAK SFC PRESSURE
GRADIENT AND RELATIVELY LIGHT WINDS SHOULD ALLOW FOR A LAKE BREEZE
TO DEVELOP. WITH ANOTHER LOW DEVELOPING OVER THE CNTRL PLAINS AND
HIGH PRESSURE OVER THE SERN CONUS...SFC WINDS SHOULD BE PREVAILING
SLY TO SWLY...SO...THE LAKE BREEZE SHOULD ASSUME A NW-SE ORIENTATION
AND LIKELY ONLY MOVE INLAND FROM CHICAGO NORTHWARD. WHILE MUCH OF
THE CWA ENJOYS TEMPERATURES BACK IN THE MIDDLE 70S ON SATURDAY...THE
LAKEFRONT LOCATIONS FROM CHICAGO TO WAUKEGAN SHOULD SEE HIGHS ONLY
IN THE LOWER TO MIDDLE 60S.
THE NEXT SIGNIFICANT CHANCE FOR PCPN WILL COME BY SATURDAY EVENING
AS THE AFOREMENTIONED LOW PRESSURE SYSTEM TRACKS THROUGH THE UPPER
MIDWEST AND DRAGGING ANOTHER COLD FRONT ACROSS THE AREA. THIS
SYSTEM IS NOT LOOKING QUITE AS DYNAMIC AS THE SYSTEM EXPECTED THIS
EVENING...SO...THE CHANCES FOR MORE SEVERE WEATHER ARE LOW. A SRN
STREAM SYSTEM LIFTING OUT OF THE SRN ROCKIES BY SATURDAY NIGHT WILL
DEVELOP A WAVE ON THE SRN END OF THE FRONT. THIS WAVE IS FORECAST
TO RIPPLE ALONG THE BOUNDARY TO THE NORTHEAST...WHICH WILL HELP TO
SLOW THE OVERALL PROGRESSION OF THE SYSTEM AND A STRUNG OUT FRONTAL
SYSTEM IS EXPECTED TO EXTEND FROM THE RED RIVER VALLEY INTO THE WRN
GREAT LAKES BY SUNDAY NIGHT. WITH THE FRONT NOT EXPECTED TO PUSH
EAST OF THE AREA UNTIL TUESDAY MORNING...THERE WILL BE AN EXTENDED
CHANCE FOR SHOWERS AND THUNDERSTORMS FROM LATE SATURDAY NIGHT
THROUGH TUESDAY MORNING.
FOR THE LONGER RANGE FORECAST PERIOD...FROM TUESDAY THROUGH
THURSDAY...FOLLOWING THE PASSAGE OF THE COLD FRONT AND THE
ASSOCIATED LOW...THERE WILL STILL BE LINGERING CHANCES FOR SHOWERS
WITH A SERIES OF NRN STREAM SHORT WAVES DROPPING OUT OF CANADA RIGHT
ON THE HEELS OF THE EXITING SYSTEM. WITH SOME UNCERTAINTY TO THE
EXACT TIMING OF THIS SERIES OF SHORTWAVES...WILL CARRY AT LEAST
CHANCE POPS THROUGH THE EXTENDED PERIOD. WITH THE TRAIN OF
SHORTWAVES CARVING OUT A LONG WAVE TROUGH OVER THE GREAT LAKES AND
MIDWEST...TEMPERATURES FOR TUESDAY THROUGH THURSDAY SHOULD BE BACK
TO WELL BELOW NORMAL. HIGHS FOR TUESDAY THROUGH THURSDAY ARE
EXPECTED TO BE IN THE LOWER TO MIDDLE 60S WITH EVEN SOME UPPER 50S
POSSIBLE ALONG THE LAKEFRONT. OVERNIGHT LOWS THROUGH THE EXTENDED
PERIOD SHOULD ONLY BE IN THE 40S.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* GUSTY SOUTHERLY WINDS THIS EVENING.
* A PERIOD OR TWO OF SHRA/SCT TSRA LATE THIS EVENING THROUGH EARLY
FRIDAY MORNING...WITH A CHANCE FOR ADDITIONAL SHRA/TSRA THROUGH
MID FRIDAY MORNING.
* MVFR CEILINGS FRIDAY MORNING.
RC
//DISCUSSION...UPDATED 00Z...
LOW PRESSURE IS CENTERED NEAR THE MN/IA BORDER EAST OF FSD EARLY
THIS EVENING...WITH A COLD FRONT TRAILING TO ITS SOUTH. GUSTY
SOUTH-SOUTHWEST WINDS CONTINUE AT ALL TAF SITES WHICH ARE
ENTRENCHED IN THE WARM SECTOR OF THE STORM SYSTEM. AN UPPER
DISTURBANCE IN ADVANCE OF THE SYSTEM IS RESULTING IN SCT TSRA FROM
NORTHEAST MO TO NORTHWEST/NORTH CENTRAL IL...WITH TSRA AT LEAST IN
THE VICINITY OF RFD FOR THE NEXT FEW HOURS. SCT SHRA/TSRA SHOULD
GRADUALLY DEVELOP TOWARD THE EASTERN TERMINALS LATER THIS EVENING
BUT BASED ON TRENDS HAVE PUSHED BACK TIMING A FEW HOURS. CLOSER
APPROACH OF COLD FRONT OVERNIGHT INTO EARLY FRIDAY SHOULD RESULT
IN ANOTHER ROUND OF SCT TO WIDESPREAD SHRA/TSRA. OVERALL DO NOT
HAVE HIGH CONFIDENCE IN PREVAILING TSRA AT ANY TAF SITE SO HAVE
BACKED OFF TO VICINITY MENTION BUT WILL AMEND AS NEEDED. THERE IS
UNCERTAINTY WITH IMPACT OF OVERNIGHT CONVECTION ON INSTABILITY
FRIDAY MORNING AND ALSO FOCUS SHOULD BE TRENDING MAINLY TO THE
SOUTHEAST OF THE EASTERN TERMINALS. FEEL THAT CHANCES FOR
ADDITIONAL THUNDER ARE LOW BUT NONZERO...AND HAVE COVERED
POTENTIAL WITH A VCSH MENTION.
OTHER CONCERN IS FOR A PERIOD OF MVFR CIGS FROM EARLY TO MID
MORNING FRIDAY. SUSPECT THAT GUIDANCE INDICATING LOW MVFR AND EVEN
IFR CIGS IS OVERDONE WITH LOW LEVEL MOISTURE SO HAVE MAINTAINED A
HIGH END MVFR CIG WHICH SHOULD SCATTER BY LATE MORNING. AS FRONTAL
TROUGH CROSSES THE TERMINALS...WINDS WILL VEER SOUTHWESTERLY AND
THEN WESTERLY WITH INCREASED SPEEDS/GUSTS THAT WILL LIKELY QUICKLY
DIMINISH WITH SUNSET FRIDAY EVENING AS WEAK HIGH PRESSURE SPREADS
OVER THE AREA.
RC
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH WITH WIND TRENDS.
* MEDIUM-HIGH IN SHRA/VCTS OVERNIGHT...MEDIUM CONFIDENCE IN
TIMING...LOW IN PREVAILING TSRA AT TERMINALS.
* LOW IN ADDITIONAL TSRA THROUGH MID FRIDAY MORNING.
* MEDIUM-HIGH IN A PERIOD OF MVFR CIGS FRIDAY MORNING.
RC
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...DAYTIME VFR...LAKE BREEZE WIND SHIFT POSSIBLE.
SHRA/TSRA POSSIBLE OVERNIGHT.
SUNDAY...PERIODS OF SHRA/TSRA POSSIBLE. SOUTHERLY WINDS.
MONDAY...PERIODS OF SHRA/TSRA POSSIBLE. SOUTH TO SOUTHWEST WINDS.
TUESDAY AND WEDNESDAY...CHANCE SHRA.
RC
&&
.MARINE...
218 PM CDT
A WARM FRONT DRAPED ACROSS THE NORTHERN PART OF THE LAKE LATE THIS
AFTERNOON WILL SHIFT NORTH OF THE LAKE THIS EVENING...YIELDING
SOUTHERLY WINDS ACROSS THE ENTIRE LAKE. GUSTS AROUND 25 KT...AT
TIMES POSSIBLY REACHING 30 KT BRIEFLY...WILL CONTINUE ACROSS
ILLINOIS AND INDIANA NEAR SHORE AREAS THROUGH TONIGHT AND INTO
FRIDAY. STORMS LOOK LIKELY LATE TONIGHT INTO FRIDAY MORNING...A
FEW OF WHICH COULD BE GUSTY. AS THE LOW PRESSURE DRIVING THE
SOUTHERLY WINDS MOVES FROM IOWA THIS AFTERNOON THROUGH ONTARIO ON
FRIDAY IT WILL STEER A COLD FRONT OVER LAKE MICHIGAN ON FRIDAY
NIGHT. THIS FRONT WILL BE WEAKENING THOUGH AND ONLY BRIEFLY TURN
THE WINDS WEST-SOUTHWEST BEFORE TURNING BACK SOUTHERLY THIS
WEEKEND. THE NEXT AREA OF LOW PRESSURE WILL NEAR THE LAKE DURING
LATE SUNDAY INTO MONDAY.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 7 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
611 PM CDT Thu May 8 2014
.DISCUSSION...
ISSUED 258 PM CDT Thu May 8 2014
Temperatures warming nicely across the forecast area today, with
gusty south-southwest winds and mainly some high clouds. Mostly in
the mid 80s, although some 90 degree temperatures reported at
Champaign and Rantoul at 2 pm. Convection developing as expected
west of the Mississippi River, with one cluster over
Minnesota/Iowa along the warm front, and the second developing
over western Missouri just ahead of the cold front. Both fronts
are tied into a surface low over northeast Nebraska.
Initial forecast concerns are with thunderstorm trends through
Friday including severe threat, followed by timing of
showers/storms for much of the first half of next week.
SHORT TERM...Tonight through Friday Night:
Latest mesoscale analysis showing CAPE`s of 1000-1500 J/kg over
the forecast area, with the cap eroding along the Mississippi
River. Latest HRRR has the storms reaching the Illinois River
valley by around 6 pm and I-57 toward 9-10 pm. Areas west of I-55
most likely to see any severe weather as the instability will be
decreasing by the time the storms make it further east. Hail/wind
remains the primary concern with the storms. Secondary line of
showers/storms immediately ahead of the front will begin to move
in after midnight, but think the severe threat will be be over by
that point.
Extent of overnight convection will dictate where the severe
threat is for Friday. Areas south of I-70 would be most likely as
the front comes in and with outflows from the earlier convection
around, but additional instability would likely have to come
during the afternoon in between periods of storms. Will mention
categorical PoP`s over 80% across the southeast third of the
forecast area through the day, with not the rain not fully moving
out of the southeast CWA until closer to midnight. Further west,
will largely go dry west of I-55 during the afternoon.
LONG TERM...Saturday through Thursday:
Short period of dry weather on tap for Saturday as a narrow ridge
axis slides by, but next wave will be approaching from the Plains.
Have added some slight chance PoP`s in the afternoon west of I-55,
but main period of convection will develop Saturday night. Will
introduce likely PoP`s late Saturday night across about the
northwest 2/3 of the forecast area, lingering into Sunday across
the north as remnants of an MCS move across the area.
The forecast from Sunday night into Monday night is more of a
challenge. The GFS is much faster than the ECMWF or Canadian
models by surging a cold front through the area Monday night,
while the latter models are close to 24 hours slower. This slower
solution would keep a good part of Sunday night and Monday dry.
This appears to be tied into phasing of the long wave trough across
the Rockies Sunday night, with the GFS featuring a more
progressive wave and the ECMWF cutting off a low over the northern
Dakotas for a time early next week. Am trending the blended model
grids on the slower side, but have not completely eliminated any
PoP`s Monday/Tuesday.
Deep upper trough over the central U.S. to provide a period of
cooler weather for the middle of the week. Will see highs only in
the 60s much of the Tuesday-Thursday period.
Geelhart
&&
.AVIATION...
ISSUED 605 PM CDT Thu May 8 2014
Band of showers and thunderstorms will affect our western TAF
sites this evening with an overall increase in coverage later
tonight across the east which will gradually bring cigs to
MVFR category during the early morning hours. First band of
rain will stay along and west of I55 early this evening with
an increase in coverage to the east roughly after 03z. Once
the MVFR ceilings set in aftr 05z in the west and 08z in the
east, they are expected to hold over the area with rain and
isold thunder into the morning hours of Friday.
Next problem will be with the threat for redevelopment of showers
and thunderstorms along a weakening cold front tomorrow afternoon
and evening. For now will include a VCTS group for DEC and CMI and
see how the overnight precip affects coverage of rain tomorrow
afternoon. Surface winds will continue from a southerly direction
at 12 to 17 kts tonight with an occasional gust up to 25 kts at
times this evening. Winds will veer more into a southwest to west
direction at 12 to 17 kts on Friday with gusts around 25 kts,
especially in the afternoon.
Smith
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1246 AM CDT WED MAY 7 2014
.DISCUSSION...
909 PM CDT
CONVECTION DEVELOPING ACROSS THE FAR NORTH METRO PROMPTED A
SPECIAL WEATHER STATEMENT ISSUANCE. THE FORECAST WAS UPDATED TO
REFLECT SLIGHTLY HIGHER CHANCES OF THUNDER NORTH OF INTERSTATE 80
THE REST OF TONIGHT...AS WELL AS TO MAKE SOME HOURLY FORECAST
TEMPERATURE ADJUSTMENTS.
THE SURFACE STATIONARY FRONT REMAINS DRAPED WELL TO OUR SOUTH
THIS EVE WITH 00Z RAOBS AND CURRENT PROFILER ANALYSIS INDICATING A
40-45 KT SRLY LOW-LEVEL JET HAVING DEVELOPED NORTH OF THIS INTO IA
AND ACROSS NORTHERN IL. THIN ARCS OF TCU WERE NOTED ON LATE DAY
VISIBLE SATELLITE AND OBSERVATIONS HAVE INDICATED AN INCREASING
LAYER OF 8K-10K FT CIGS. THE 00Z DVN RAOB AND AREA AMDAR SOUNDINGS
WERE INDICATING A MOISTENING AROUND THAT 800-750MB LAYER...WHICH
WHEN LIFTED FROM THAT LAYER ON THE DVN SOUNDING WOULD PROVIDE OVER
1500 J/KG OF MUCAPE...THOUGH WITH STILL A MINOR CAP. AS A SUBTLE
SHORT WAVE NEAR KANSAS CITY PROGRESSES NORTHEAST AND OVERALL
MOISTURE TRANSPORT STRENGTHENS...WOULD EXPECT TO SEE THAT SLIGHT
CAPPING OVERCOME WITH ISOLATED TO SCATTERED CONVECTION DEVELOPING
ACROSS THE EASTERN IA/SOUTHERN WI REGION...AND POSSIBLY NORTHERN
IL...ESPECIALLY GIVEN CURRENT STORM WAS ALREADY ABLE TO DEVELOP.
IN ADDITION...THE TREND WITH THE HOURLY-RAN HRRR HAS BEEN TO
INCREASE COVERAGE OF SHOWERS/STORMS EARLY OVERNIGHT...WHICH GIVEN
CURRENT OBSERVATIONAL ANALYSIS MAKES SENSE. HAVE BOOSTED POPS
SOME OVER THE NORTHERN TWO TIERS OF COUNTIES BUT REMAIN IN THE
CHANCE CATEGORY.
GIVEN THE RADAR TRENDS WITH THE MCHENRY/LAKE COUNTY
STORM...HAVING SPRUNG TO 40 DBZ OVER 35K FT WITHIN THREE SCANS OF
DEVELOPING...COULD STILL SEE AN ELEVATED HAILER OR TWO ACROSS FAR
NORTHERN ILLINOIS. THE ENVIRONMENT FOR THESE REMAINS MORE
SUPPORTIVE TO THE WEST AND NORTHWEST OF THE LOCAL AREA.
THE MARINE LAYER CONTINUED TO RE-INFORCE ITSELF EARLY THIS EVE
ACROSS THE NORTH AND CENTRAL PARTS OF THE CHICAGO METRO...WITH
SOME MID 40S ALONG THE LAKE SHORE AND LOWER 50S STARTING TO REACH
SOME OUTLYING AREAS. DID ADJUST MINS DOWN BUT INDICATED SORT OF A
LEVELING OFF TREND TO THIS TEMPERATURE FALL...WITH EVEN POTENTIAL
RISING LATE GIVEN INCREASING SURFACE DEW POINTS.
LOOKING AHEAD TO WEDNESDAY...STILL SOME POSSIBILITY TO SEE
ISOLATED CONVECTION IN THE MORNING AS A WEAK SHORT WAVE
PASSES...AND THE 00Z NAM CONTINUES TO SHOW THIS SUBTLE FEATURE.
COULD ALSO BE SOME FOG DEVELOPING ACROSS FAR SOUTHERN LAKE
MICHIGAN DURING THE MORNING AS THE WARM FRONT AND HIGH DEW POINTS
BUTT UP AGAINST THE COOL LAKE. WITH THE WARM FRONT LIKELY TO
PROGRESS SLOWER OVER THE MARINE LAYER...IT COULD INDUCE THE FOG.
HAVE NOT ADDED INTO THE FORECAST AT THIS TIME BUT SOMETHING WE
WILL WATCH AS THAT WOULD POSSIBLY MOVE INTO LAKE ADJACENT AREAS OF
THE CHICAGO METRO.
MTF
//PREV DISCUSSION...
329 PM CDT
SHORT TERM...TONIGHT THROUGH FRIDAY...
PRIMARY FORECAST CONCERNS ARE WITH HOW WARM
TEMPERATURES GET TOMORROW AND THURSDAY AND ON THUNDERSTORM
POTENTIAL.
W/V IMAGERY SHOWS THE ONGOING AMPLIFICATION OF UPPER RIDGING OVER
THE MIDWEST INDUCED BY A DEEP TROUGH/CLOSED LOW OVER THE SOUTHWEST
US. AT THE SURFACE...LOW PRESSURE IS DEVELOPING OVER THE SOUTHERN
HIGH PLAINS WITH THE VERY STRONG WARM FRONT THAT HAS BEEN IN PLACE
OVER THE REGION THE PAST FEW DAYS STRETCHING ACROSS DOWNSTATE IL
AND IN. STRONG WAA ALOFT NORTH OF THE BOUNDARY HAS ALLOWED FOR
TEMPERATURES TO WARM ABOVE 70 SOUTH OF I-80...WHILE ONSHORE FLOW HAS
RESULTED IN ANOTHER COOL DAY FOR LAKESHORE AREAS.
TONIGHT...
AS THE SFC WARM FRONT INCHES NORTH...A STRONG LOW LEVEL JET WILL
DEVELOP WITH GOOD MOISTURE TRANSPORT AND CONVERGENCE FOCUSED ON THE
NOSE OF THE LLJ INTO NORTHEAST IA AND FAR SOUTHERN WI. GUIDANCE ALSO
HINTS AT A MIDLEVEL SHORTWAVE RIDING IN ON SOUTHWEST FLOW. DESPITE
SOME MODELS SUGGESTING CONTRARY...CONTINUE TO THINK THAT FOCUS FOR
CONVECTION TONIGHT WILL REMAIN MAINLY NORTH OF THE CWA...THOUGH
COULD CLIP THE FAR NORTH...WHERE GENERALLY SLIGHT POPS WERE
MAINTAINED LATE EVE THROUGH OVERNIGHT. GIVEN PRESENCE OF MODERATE
MUCAPE AND STRONG EFFECTIVE DEEP LAYER SHEAR...IF ANY STORMS DO
OCCUR OVER THE FAR NORTH...STRONGER STORMS COULD YIELD ISOLATED
SEVERE HAIL. LOW TEMPS WILL RANGE FROM MID 40S IN FAR NORTHEAST NEAR
THE LAKE TO AROUND 60 IN THE SOUTHWEST CWA.
WEDNESDAY AND WEDNESDAY NIGHT...
MAIN UNCERTAINTY IS WITH TIMING OF SFC WARM FRONT LIFTING NORTH
THROUGH CWA...THOUGH HAVE SOME CONCERN FOR ELEVATED HIGH-BASED
CONVECTION NORTH OF THE WARM FRONT DURING THE MORNING MAINLY NORTH
OF I-88. PRIMARY FOCUS SHOULD STILL BE NORTH OF THE CWA...BUT DID
ADD A SLIGHT POP FOR AREA MENTIONED ABOVE. BIG STORY TOMORROW IS THE
RAPID FLIP TO SUMMER WARMTH AS THE WARM FRONT LIFTS NORTH AS 850/925
MB TEMPS RISE TO LEVELS SUPPORTING AT LEAST LOW-MID 80S IN THE WARM
SECTOR. SOME HIGH RES GUIDANCE REALLY SLOWS THE NWD PROGRESS OF THE
FRONT TOMORROW...BUT THESE MODELS SUCH AS THE NAM ARE LIKELY
AFFECTED BY OUTFLOW FROM OVERNIGHT CONVECTION. THE IL NORTH SHORE
WILL LIKELY REMAIN QUITE COOL INTO THE AFTERNOON BUT THEN THE WARM
AIR SOUTH OF THE BOUNDARY WILL RUSH IN BY THE LATE AFTERNOON OR
EARLY EVENING...WITH TEMPS JUMPING SEVERAL DEGREES. DEWPOINTS WILL
ALSO RISE TO CLOSE TO OR AROUND 60 AS THE FRONT LIFTS NORTH...ADDING
A BIT OF A MUGGY FEEL TO THE AIRMASS. THE AREA SHOULD BE CAPPED TO
CONVECTION ON WEDNESDAY NIGHT WITH NO REAL FOCUS TO BREACH THE CAP
SO HAVE MAINTAINED A DRY FCST. OVERNIGHT TEMPS WILL BE NORMAL FOR
MID SUMMER IN THE MID AND UPPER 60S. THIS WILL PROVIDE A WARM
STARTING POINT FOR THURSDAY.
THURSDAY AND THURSDAY NIGHT...
CONTINUE TO SUSPECT AFTER EXAMINING FORECAST SOUNDINGS THAT MUCH IF
NOT ALL OF THE AREA COULD SEE A MAINLY DRY DAYTIME WITH THE WARM
SECTOR FIRMLY IN PLACE AND A STRONG CAP INDICATED. MOST OF THE
MIDLEVEL SHORTWAVE FORCING DURING DAY SHOULD AT MOST SKIRTH THE FAR
NORTHWEST CWA AND SFC COLD FRONT WILL BE WELL BACK TO THE WEST UNTIL
THE NIGHTTIME. HAVE MAINTAINED GENERAL IDEA OF GRADUALLY SPREADING
IN CHANCE POPS BUT BASED ON TRENDS TODAY...COULD FORSEE NEEDING TO
LOWER THESE. THIS IS DESPITE HIGHS AGAIN IN THE MID 80S AND
DEWPOINTS AROUND 60 SUPPORTING MODERATE MLCAPE VALUES.
MORE FAVORABLE FORCING WILL ARRIVE DURING THE EVENING AND THEN
MOISTURE CONVERGENCE ASSOCIATED WITH THE APPROACHING COLD FRONT WILL
SUPPORT HIGHER SHOWER/TSTM COVERAGE OVERNIGHT. ARGUING AGAINST
WIDESPREAD SEVERE STORMS WILL BE DIURNALLY UNFAVORABLE TIMING...BUT
ESPECIALLY WESTERN CWA COULD HAVE ENOUGH INSTABILITY STILL IN PLACE
ALONG WITH STRONG DEEP LAYER SHEAR TO SUPPORT A WIND/HAIL THREAT.
WITH FRONT REMAINING TO THE WEST THROUGH THE NIGHT...OVERNIGHT TEMPS
WILL AGAIN BE QUITE MILD IN THE MID 60S.
FRIDAY...
REMAINS OF OVERNIGHT CONVECTION SHOULD BE MOVING INTO EAST/SOUTHEAST
CWA DURING MORNING...BUT WITH COLD FRONT ONLY MAKING SLOW PROGRESS
AND AIR MASS STILL BEING WARM/MOST...WILL HAVE TO WATCH FOR
REGENERATION OF STRONGER CONVECTION IN THE SOUTHEAST DURING THE
AFTERNOON INTO THE EARLY EVENING. 850/925 MB TEMPS WILL REMAIN IN
TEENS CELSIUS THROUGH AFTN SO HIGHS SHOULD REACH THE LOWER-MID 70S.
LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...
UNLIKE WHAT WE HAVE SEEN AFTER PREVIOUS WARM SPELLS THIS SPRING...WE
DO NOT LOOK TO RETURN TO A MUCH COOLER THAN NORMAL PATTERN AFTER
THE PASSAGE OF THE LATE WEEK SYSTEM. THE JET STREAM PATTERN LOOKS
TO REMAIN MORE ZONAL...WHICH WILL SUPPORT NORMAL TO SLIGHTLY ABOVE
NORMAL TEMPS AND POSSIBLY MORESO AS PER 12Z OPERATIONAL EUROPEAN
MODEL EARLY NEXT WEEK. UNCERTAINTY INCREASES IN THE OPERATIONAL
AND ENSEMBLE MODELS...BUT IT APPEARS AFTER A PRIMARILY DRY
SATURDAY...THE PATTERN COULD BE A BIT UNSETTLED WITH PERIODIC TSRA
CHANCES. TIMING IS THE MAIN QUESTION AS THE GFS IS MUCH MORE
PROGRESSIVE WITH THE NEXT SYSTEM. AS ALLUDED TO ABOVE...THIS WILL
ALSO IMPACT HOW WARM TEMPERATURES GET EARLY NEXT WORK WEEK.
CONFIDENCE IS ALSO LOWER ON WHICH DAYS ARE MOST SYNOPTICALLY
FAVORABLE FOR ONSHORE FLOW KEEPING AT LEAST PORTIONS OF THE
LAKEFRONT MUCH COOLER THAN INLAND.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* ISOLATED TSRA EARLY THIS MORNING NORTH OF ORD.
* WARM FRONT AND ASSOCIATED WIND DIRECTIONS/SPEEDS FROM SUNRISE
THROUGH LATE AFTERNOON.
//DISCUSSION...UPDATED 06Z...
ISOLATED THUNDERSTORMS ARE STILL POSSIBLE ACROSS FAR NORTHEAST IA
AND FAR NORTHWEST IL THROUGH DAYBREAK AS AN UPPER LEVEL RIDGE
BUILDS NORTH ACROSS THE REGION. ANYTHING THAT FORMS WILL LIFT
NORTHEAST AND NOT EXPECTING ANY OF THIS ACTIVITY TO REACH THE
CHICAGO AREA TERMINALS...REMAINING NORTH OF ORD/DPA. DURATION WILL
ALSO BE RATHER SHORT AT RFD...BUT CONFIDENCE FOR TIMING IS LOW SO
MAINTAINED CURRENT 08Z-11Z TIMING. DAYLIGHT HOURS TODAY INTO
TONIGHT ARE EXPECTED TO BE DRY ACROSS THE ENTIRE AREA.
A WARM FRONT CURRENTLY EXTENDS FROM NORTHERN MISSOURI AND ACROSS
CENTRAL ILLINOIS AND WILL SLOWLY LIFT NORTH THIS MORNING AND
SHOULD REACH THE I-80 CORRIDOR BY LATE MORNING. ITS PROGRESS NORTH
COULD BE SLOWED BY THE COLDER AIR OVER LAKE MICHIGAN AND HOW FAST
IT ADVANCES NORTH FIRST TO MDW AND THEN TO ORD/DPA IS SOMEWHAT
UNCERTAIN AND MAINTAINED CURRENT TIMING FROM PREVIOUS FORECASTS.
ITS POSSIBLE THAT THIS FRONTAL BOUNDARY MAY STALL IN AND AROUND
ORD/MDW WITH SOME GUIDANCE SHOWING SOUTHERLY WINDS TURNING BACK
SOUTHEASTERLY LATE IN THE AFTERNOON. UPDATES/CHANGES TO THIS WIND
FORECAST CAN BE EXPECTED AS THE FRONT APPROACHES LATER THIS
MORNING INTO THIS AFTERNOON AND TIMING/SPEED BECOMES MORE CERTAIN.
CMS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM ANY TSRA EARLY THIS MORNING WILL REMAIN NORTH OF ORD.
* MEDIUM FOR WIND DIRECTIONS/SPEEDS THROUGH SUNRISE...THEN LOW
THIS MORNING AND THIS AFTERNOON AS WARM FRONT LIFTS NORTH. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
* THURSDAY...CHANCE OF TSRA IN THE AFTERNOON. GUSTY SOUTHERLY WINDS.
* THURSDAY NIGHT...TSRA LIKELY.
* FRIDAY...CHANCE OF TSRA. GUSTY WESTERLY WINDS.
* SATURDAY...DRY/VFR.
* SUNDAY AND MONDAY...CHANCE OF TSRA.
KJB
&&
.MARINE...
302 PM CDT
HIGH PRESSURE EXTENDS FROM HUDSON BAY TO THE MID ATLANTIC WHILE
LOW PRESSURE REMAINS NEARLY STATIONARY AND SLOWLY DEEPENS OVER THE
CENTRAL PLAINS. A WARM FRONT EXTENDING EAST FROM THE LOW...THROUGH
THE OHIO VALLEY WILL REMAIN NEARLY STATIONARY...WITH ANY NORTHWARD
PROGRESS BLOCKED BY THE HIGH. THIS WILL KEEP BRISK EASTERLY FLOW
OVER LAKE MICHIGAN UNTIL THE WARM FRONT CAN PUSH TO THE NORTH. BY
LATE WEDNESDAY MORNING...THE HIGH WILL BEGIN TO SLIDE TO THE
EAST...ALLOWING THE WARM FRONT TO SURGE NORTHWARD. THE PARENT LOW
IS EXPECTED TO TRACK TO THE NORTHEAST AND BECOME ELONGATED THROUGH
WEDNESDAY NIGHT AND INTO THURSDAY...WITH THE WARM FRONT REACHING
THE FAR NORTH END OF THE LAKE BY THURSDAY AFTERNOON...WITH WINDS
TURNING SOUTHERLY. THE WARM FRONT SHOULD FINALLY REACH THE FAR
SOUTHERN TIP OF THE LAKE BY LATE WEDNESDAY MORNING...ALLOWING FLOW
TO TURN OFFSHORE OF THE INDIANA COAST. THE FRONT SHOULD PUSH SOUTH
OF THE ILLINOIS NEARSHORE WATERS BY LATE AFTERNOON...SO WILL NOT
MAKE ANY CHANGES TO THE GOING SMALL CRAFT ADVISORY AT THIS TIME.
THE SOUTHERLY GRADIENT WILL TIGHTEN THURSDAY INTO EARLY
FRIDAY...ALLOWING SOUTHERLY WINDS TO STRENGTHEN...BUT VERY WARM
AIR OVERSPREADING THE COLD LAKE WATER SHOULD HELP LIMIT
MIXING...ESPECIALLY OVER THE OPEN WATERS. THE NEARSHORE WATERS ARE
BEGINNING TO GET A BIT WARMER...SO THERE COULD BE BETTER MIXING
THERE AND WIND SPEEDS MAY FLIRT WITH GALE FORCE...BUT FOR
NOW...FEEL THAT 30KT SOUTHERLY WINDS SHOULD BE THE PREVAILING
CONDITION FOR THURSDAY INTO EARLY FRIDAY AFTERNOON. BY LATE FRIDAY
AFTERNOON OR EARLY FRIDAY EVENING...THE LOW WILL TRACK NORTH OF
THE GREAT LAKES TO NEAR JAMES BAY. AN ASSOCIATED COLD FRONT WILL
SWEEP ACROSS THE LAKE FRIDAY AFTERNOON...TURNING WINDS TO WESTERLY
BY FRIDAY EVENING. HIGH PRESSURE WILL THEN BUILD ACROSS THE LAKE
BEGINNING FRIDAY NIGHT AND REMAINING IN PLACE INTO SUNDAY MORNING.
WHILE THE HIGH PRESSURE RESIDES OVER THE LAKE...WINDS SHOULD BE
RELATIVELY LIGHT WITH LAKE BREEZE DEVELOPMENT POSSIBLE.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 PM
WEDNESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
548 PM EDT WED MAY 7 2014
.SYNOPSIS...
ISSUED AT 547 PM EDT WED MAY 7 2014
A WARM FRONT WILL CONTINUE TO SHIFT NORTH THROUGH LOWER MICHIGAN
TONIGHT. ANY SHOWERS AND THUNDERSTORMS ARE EXPECTED TO REMAIN WELL
NORTH OF THE FRONT...WHICH SHOULD RESULT IN DRY CONDITIONS ACROSS
OUR AREA TONIGHT. LOWS OVERNIGHT WILL RANGE FROM THE MID 50S OVER
SOUTHEAST MICHIGAN AND NORTHWEST OHIO TO THE MID 60S OVER CENTRAL
INDIANA. SUNNY TO PARTLY CLOUDY SKIES SHOULD ALLOW HIGH
TEMPERATURES TO REACH WELL INTO THE MID 80S THROUGHOUT THE AREA
THURSDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 352 PM EDT WED MAY 7 2014
NEAR TERM FOCUS ON WIDELY SCT TSTMS ACROSS N ILLINOIS WITH WEAKER
SHOWERS COMING ACROSS SOUTHERN LK MI. ILLINOIS ACTIVITY WAS BEING
ENHANCED TO SOME DEGREE BY NE MOVING SHORT WAVE WHICH WILL PASS
ACROSS THE AREA INTO THIS EVENING. STEEP MID LEVEL LAPSE RATES
WERE IN PLACE ACROSS THE REGION...BUT STRONG ELEVATED MIXED LAYER
WAS PREVENTING MORE WIDESPREAD DEVELOPMENT. ACTIVITY MOVING ACROSS
THE LAKE WAS WEAKENING AS IT MOVES EAST. WARM FRONT HAS BEEN
SURGING NORTH MUCH OF THE DAY WITH SW HALF OF THE AREA NOW IN THE
UPR 70S TO LOW 80S. KIWX 88D APPEARS TO BE SHOWING THIS FEATURE
WHICH LOOKS TO BE QUASI STATIONARY ALONG ROUTE 30. WOULD EXPECT
THIS TO GET MOVING AGAIN ONCE THE SHORT WAVE PUSHES THROUGH. FOR
NOW WILL HAVE A DRY FORECAST WITH EVE SHIFT TO MONITOR TRENDS FOR
ADDITION OF ISOLATED CONVECTION UNTIL SUNSET.
LOW LEVEL MSTR WILL CONTINUE TO PUSH INTO THE REGION TONIGHT WITH A
BALMY EARLY MAY NIGHT IN STORE WITH LOWS A GOOD 10 TO 15 DEGREES
ABOVE NORMAL RANGING FROM THE MID 50S TO LOW 60S. SEVERAL OF THE
HIGH RES MODELS HAVE BEEN TRYING TO DEVELOP A STRATUS DECK ACROSS
MUCH OF THE AREA AS COOLING TAKES PLACE. WHILE SETUP CAN`T BE FULLY
DISMISSED...THINK MODELS ARE GETTING A BIT CARRIED AWAY WITH IT AT
THIS POINT. IF ON THE OTHER HAND THE FRONTAL BOUNDARY REMAINS
STALLED IN THE AREA...THEN A GREATER LIKELIHOOD OF LOW CLOUDS WOULD
EXIST. STILL HOLDING WITH MOSTLY CLEAR/PARTLY CLOUDY SKIES TONIGHT.
THURSDAY SHOULD BE WARM AND UNSTABLE AS TEMPS SOAR INTO THE LOW TO
MID 80S. SFC BASED INSTABILITY WILL EXIST...BUT LACK OF TRIGGER AND
STRONG EML STILL IN PLACE TO PRECLUDE ALL BUT SOME CU DEVELOPMENT.
&&
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 352 PM EDT WED MAY 7 2014
NORTHWARD LOW LEVEL MOISTURE TRANSPORT TO COMMENCE THURSDAY
NIGHT VIA A 50 KNOT SOUTHERLY LOW LEVEL JET. SEVERAL WEAK MID/UPPER
PERTURBATIONS WILL LIKELY TRACK INTO THE OHIO VALLEY/WESTERN GREAT
LAKES REGION DURING THIS TIME. ELEVATED MIXED LAYER WILL LIKELY
LIMIT ANY CONVECTION FOR MOST OF THE THURSDAY NIGHT PERIOD. CORFIDI
VECTORS SHOULD TEND TO BECOME MORE SOUTHWESTERLY LATE THURSDAY NIGHT
POSSIBLY FAVORING EASTWARD PROPAGATION OF IL CONVECTION INTO WESTERN
PORTIONS OF THE AREA TOWARD FRIDAY MORNING. A FAIRLY STRONG WEST TO
EAST ORIENTED MUCAPE GRADIENT SHOULD EXIST ACROSS THE REGION
HOWEVER...SO SOME QUESTION AS TO WHAT PROPAGATION MODE THIS
CONVECTION WILL TAKE. HAVE NOT MADE SIGNIFICANT CHANGES TO PREVIOUS
POP FORECAST THURSDAY NIGHT...CONFINING OVERNIGHT LIKELY POPS TO THE
FAR WEST.
PRIMARY LOW LEVEL MOISTURE TONGUE WILL ADVECT INTO THE REGION EARLY
FRIDAY...AIDED BY BROAD SYNOPTIC SCALE PRE-FRONTAL LOW LEVEL
CONFLUENCE. THIS SHOULD SUPPORT EASTWARD EXPANSION OF SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS IN THE MORNING. CONFIDENCE IN
FRIDAY AFTERNOON CONVECTIVE POTENTIAL STILL SOMEWHAT MUDDLED BY
INFLUENCES OF MORNING PRECIP. MODELS ALSO STILL EXHIBITING SOME
SIGNIFICANT DIFFERENCES IN TERMS OF TIMING NEXT PV ANOMALY TO LIFT
INTO THE GREAT LAKES REGION SOME TIME LATE FRIDAY AFTERNOON/NIGHT.
EXIT REGION OF 120 KNOT UPPER JET STREAK SHOULD ALSO ENHANCE
SYNOPTIC SCALE LIFT BY FRIDAY EVENING...SUPPORTING ADDITIONAL
CONVECTIVE DEVELOPMENT ALONG MAIN COLD FRONTAL BOUNDARY. ENHANCED
DEEP LAYER SHEAR ASSOCIATED WITH THIS POCKET OF STRONGER UPPER
FLOW...AND MORE LIKELY POSITION OF PRIMARY INSTABILITY AXIS ACROSS
WESTERN PORTIONS OF FORECAST AREA LATE FRIDAY AFTERNOON/EARLY FRIDAY
EVENING...MAY LEND TO A SMALL WINDOW OF SEVERE POTENTIAL DURING THIS
PERIOD.
AFOREMENTIONED PV ANOMALY TO BECOME MORE INFLUENCED BY UPPER
LEVEL DEFORMATION FLOW AS IT LIFTS NORTHEASTWARD ACROSS THE GREAT
LAKES/SOUTHERN ONTARIO WHICH SHOULD TEND TO SLOW EASTWARD FRONTAL
PROGRESSION LATE FRIDAY NIGHT/EARLY SATURDAY. FRONTAL CONVERGENCE
SHOULD TEND TO WEAKEN AS THIS OCCURS...SO WOULD EXPECT DIMINISHING
COVERAGE DURING THE OVERNIGHT HOURS. HAVE MAINTAINED LOW CHANCE POPS
ACROSS FAR SOUTHEAST SATURDAY DUE TO SLOWING NATURE OF
BOUNDARY...BUT GREATER CONFIDENCE IN NEXT ROUND OF PRECIP SHOULD
HOLD OFF UNTIL LATE SATURDAY NIGHT AS LOW LEVEL ISENTROPIC UPGLIDE
COMMENCES OVER THIS BOUNDARY...PARTICULARLY ACROSS WESTERN PORTIONS
OF THE AREA.
DISTURBED SOUTHWESTERLY UPPER FLOW IN ADVANCE OF NEXT MORE
SIGNIFICANT UPPER TROUGH ACROSS WESTERN CONUS WILL PROVIDE AT LEAST
CHANCE OF SHOWERS/STORMS THROUGH MUCH OF THE LATE WEEKEND THROUGH
EARLY NEXT PERIOD. HOWEVER...SOME SUBSTANTIAL MEDIUM RANGE MODEL
DIFFERENCES PERSIST REGARDING PHASING THIS WESTERN CONUS TROUGH WITH
SOUTH CENTRAL CANADIAN UPPER LOW. EC/GEM REMAIN MUCH SLOWER AND
BETTER PHASED...WHILE GFS IS MUCH MORE PROGRESSIVE AND LESS
PHASED...TAKING COLD FRONTAL BOUNDARY EAST OF THE AREA MONDAY NIGHT.
AT THIS FORECAST DISTANCE WITH LARGE DETERMINISTIC/ENSEMBLE
SPREADS...HAVE NOT STRAYED FAR FROM CONSENSUS APPROACH OF CRALLBLEND
WHICH PROVIDES COMPROMISE IN TIMING OF THESE TWO CAMPS. OF HIGHER
CONFIDENCE IS ANOTHER WARMING TREND LATE WEEKEND INTO MONDAY IN
ADVANCE OF THIS SYSTEM...WITH HIGHS FROM MID 70S TO AROUND 80
POSSIBLE AGAIN BY SUNDAY. COOLER CONDITIONS EXPECTED ACROSS PORTIONS
OF SOUTHWEST LOWER MICHIGAN WITH SWRLY LOW LEVEL COMPONENT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 144 PM EDT WED MAY 7 2014
WARM FRONT WAS CLEARING KFWA AND WILL ARRIVE AT KSBN SHORTLY
ALLOWING FOR SOUTHERLY FLOW TO SET UP. MID/HIGH CLOUDS ABOUT ALL
THAT IS AROUND FOR THE TIME BEING. WILL BE MONITORING CONVECTION
DEVELOPING ACROSS CENTRAL ILLINOIS THAT COULD DRIFT INTO THE AREA
LATER THIS AFTERNOON/EVE. SETUP NOT THE MOST FAVORABLE SO NO
MENTION IN TAFS. OTHERWISE...INCREASE IN LL MSTR WILL TAKE PLACE
TONIGHT WITH MANY OF THE HIGH RES MODELS SUGGESTING STRATUS
DEVELOPING (SOME HINTS AT EVEN IFR CIGS). NOT READY TO BUY THIS
YET WITH RUC STILL SHOWING GENERALLY CLEAR CONDITIONS SO WILL
MAINTAIN PREV FORECAST.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...FISHER/KG
SHORT TERM...FISHER
LONG TERM...MARSILI
AVIATION...FISHER
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
353 PM EDT WED MAY 7 2014
.SYNOPSIS...
ISSUED AT 152 PM EDT WED MAY 7 2014
A WARM FRONT SHIFT QUICKLY NORTH INTO LOWER MICHIGAN BY TONIGHT.
THUNDERSTORMS ARE EXPECTED TO REMAIN WELL NORTH OF THE FRONT...
WHICH SHOULD RESULT IN DRY CONDITIONS ACROSS OUR AREA TODAY AND
TONIGHT. TEMPERATURES WILL BE WARMER... WITH HIGHS TODAY IN THE
70S OVER SOUTHERN MICHIGAN AND NORTHERN PORTIONS OF NORTHWEST
OHIO... AND IN THE LOWER TO MIDDLE 80S OVER THE REST OF THE AREA.
LOWS TONIGHT WILL RANGE FROM THE MID 50S OVER SOUTHEAST MICHIGAN
AND NORTHWEST OHIO TO THE MID 60S OVER CENTRAL INDIANA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 352 PM EDT WED MAY 7 2014
NEAR TERM FOCUS ON WIDELY SCT TSTMS ACROSS N ILLINOIS WITH WEAKER
SHOWERS COMING ACROSS SOUTHERN LK MI. ILLINOIS ACTIVITY WAS BEING
ENHANCED TO SOME DEGREE BY NE MOVING SHORT WAVE WHICH WILL PASS
ACROSS THE AREA INTO THIS EVENING. STEEP MID LEVEL LAPSE RATES
WERE IN PLACE ACROSS THE REGION...BUT STRONG ELEVATED MIXED LAYER
WAS PREVENTING MORE WIDESPREAD DEVELOPMENT. ACTIVITY MOVING ACROSS
THE LAKE WAS WEAKENING AS IT MOVES EAST. WARM FRONT HAS BEEN
SURGING NORTH MUCH OF THE DAY WITH SW HALF OF THE AREA NOW IN THE
UPR 70S TO LOW 80S. KIWX 88D APPEARS TO BE SHOWING THIS FEATURE
WHICH LOOKS TO BE QUASI STATIONARY ALONG ROUTE 30. WOULD EXPECT
THIS TO GET MOVING AGAIN ONCE THE SHORT WAVE PUSHES THROUGH. FOR
NOW WILL HAVE A DRY FORECAST WITH EVE SHIFT TO MONITOR TRENDS FOR
ADDITION OF ISOLATED CONVECTION UNTIL SUNSET.
LOW LEVEL MSTR WILL CONTINUE TO PUSH INTO THE REGION TONIGHT WITH A
BALMY EARLY MAY NIGHT IN STORE WITH LOWS A GOOD 10 TO 15 DEGREES
ABOVE NORMAL RANGING FROM THE MID 50S TO LOW 60S. SEVERAL OF THE
HIGH RES MODELS HAVE BEEN TRYING TO DEVELOP A STRATUS DECK ACROSS
MUCH OF THE AREA AS COOLING TAKES PLACE. WHILE SETUP CAN`T BE FULLY
DISMISSED...THINK MODELS ARE GETTING A BIT CARRIED AWAY WITH IT AT
THIS POINT. IF ON THE OTHER HAND THE FRONTAL BOUNDARY REMAINS
STALLED IN THE AREA...THEN A GREATER LIKELIHOOD OF LOW CLOUDS WOULD
EXIST. STILL HOLDING WITH MOSTLY CLEAR/PARTLY CLOUDY SKIES TONIGHT.
THURSDAY SHOULD BE WARM AND UNSTABLE AS TEMPS SOAR INTO THE LOW TO
MID 80S. SFC BASED INSTABILITY WILL EXIST...BUT LACK OF TRIGGER AND
STRONG EML STILL IN PLACE TO PRECLUDE ALL BUT SOME CU DEVELOPMENT.
&&
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 352 PM EDT WED MAY 7 2014
NORTHWARD LOW LEVEL MOISTURE TRANSPORT TO COMMENCE THURSDAY
NIGHT VIA A 50 KNOT SOUTHERLY LOW LEVEL JET. SEVERAL WEAK MID/UPPER
PERTURBATIONS WILL LIKELY TRACK INTO THE OHIO VALLEY/WESTERN GREAT
LAKES REGION DURING THIS TIME. ELEVATED MIXED LAYER WILL LIKELY
LIMIT ANY CONVECTION FOR MOST OF THE THURSDAY NIGHT PERIOD. CORFIDI
VECTORS SHOULD TEND TO BECOME MORE SOUTHWESTERLY LATE THURSDAY NIGHT
POSSIBLY FAVORING EASTWARD PROPAGATION OF IL CONVECTION INTO WESTERN
PORTIONS OF THE AREA TOWARD FRIDAY MORNING. A FAIRLY STRONG WEST TO
EAST ORIENTED MUCAPE GRADIENT SHOULD EXIST ACROSS THE REGION
HOWEVER...SO SOME QUESTION AS TO WHAT PROPAGATION MODE THIS
CONVECTION WILL TAKE. HAVE NOT MADE SIGNIFICANT CHANGES TO PREVIOUS
POP FORECAST THURSDAY NIGHT...CONFINING OVERNIGHT LIKELY POPS TO THE
FAR WEST.
PRIMARY LOW LEVEL MOISTURE TONGUE WILL ADVECT INTO THE REGION EARLY
FRIDAY...AIDED BY BROAD SYNOPTIC SCALE PRE-FRONTAL LOW LEVEL
CONFLUENCE. THIS SHOULD SUPPORT EASTWARD EXPANSION OF SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS IN THE MORNING. CONFIDENCE IN
FRIDAY AFTERNOON CONVECTIVE POTENTIAL STILL SOMEWHAT MUDDLED BY
INFLUENCES OF MORNING PRECIP. MODELS ALSO STILL EXHIBITING SOME
SIGNIFICANT DIFFERENCES IN TERMS OF TIMING NEXT PV ANOMALY TO LIFT
INTO THE GREAT LAKES REGION SOME TIME LATE FRIDAY AFTERNOON/NIGHT.
EXIT REGION OF 120 KNOT UPPER JET STREAK SHOULD ALSO ENHANCE
SYNOPTIC SCALE LIFT BY FRIDAY EVENING...SUPPORTING ADDITIONAL
CONVECTIVE DEVELOPMENT ALONG MAIN COLD FRONTAL BOUNDARY. ENHANCED
DEEP LAYER SHEAR ASSOCIATED WITH THIS POCKET OF STRONGER UPPER
FLOW...AND MORE LIKELY POSITION OF PRIMARY INSTABILITY AXIS ACROSS
WESTERN PORTIONS OF FORECAST AREA LATE FRIDAY AFTERNOON/EARLY FRIDAY
EVENING...MAY LEND TO A SMALL WINDOW OF SEVERE POTENTIAL DURING THIS
PERIOD.
AFOREMENTIONED PV ANOMALY TO BECOME MORE INFLUENCED BY UPPER
LEVEL DEFORMATION FLOW AS IT LIFTS NORTHEASTWARD ACROSS THE GREAT
LAKES/SOUTHERN ONTARIO WHICH SHOULD TEND TO SLOW EASTWARD FRONTAL
PROGRESSION LATE FRIDAY NIGHT/EARLY SATURDAY. FRONTAL CONVERGENCE
SHOULD TEND TO WEAKEN AS THIS OCCURS...SO WOULD EXPECT DIMINISHING
COVERAGE DURING THE OVERNIGHT HOURS. HAVE MAINTAINED LOW CHANCE POPS
ACROSS FAR SOUTHEAST SATURDAY DUE TO SLOWING NATURE OF
BOUNDARY...BUT GREATER CONFIDENCE IN NEXT ROUND OF PRECIP SHOULD
HOLD OFF UNTIL LATE SATURDAY NIGHT AS LOW LEVEL ISENTROPIC UPGLIDE
COMMENCES OVER THIS BOUNDARY...PARTICULARLY ACROSS WESTERN PORTIONS
OF THE AREA.
DISTURBED SOUTHWESTERLY UPPER FLOW IN ADVANCE OF NEXT MORE
SIGNIFICANT UPPER TROUGH ACROSS WESTERN CONUS WILL PROVIDE AT LEAST
CHANCE OF SHOWERS/STORMS THROUGH MUCH OF THE LATE WEEKEND THROUGH
EARLY NEXT PERIOD. HOWEVER...SOME SUBSTANTIAL MEDIUM RANGE MODEL
DIFFERENCES PERSIST REGARDING PHASING THIS WESTERN CONUS TROUGH WITH
SOUTH CENTRAL CANADIAN UPPER LOW. EC/GEM REMAIN MUCH SLOWER AND
BETTER PHASED...WHILE GFS IS MUCH MORE PROGRESSIVE AND LESS
PHASED...TAKING COLD FRONTAL BOUNDARY EAST OF THE AREA MONDAY NIGHT.
AT THIS FORECAST DISTANCE WITH LARGE DETERMINISTIC/ENSEMBLE
SPREADS...HAVE NOT STRAYED FAR FROM CONSENSUS APPROACH OF CRALLBLEND
WHICH PROVIDES COMPROMISE IN TIMING OF THESE TWO CAMPS. OF HIGHER
CONFIDENCE IS ANOTHER WARMING TREND LATE WEEKEND INTO MONDAY IN
ADVANCE OF THIS SYSTEM...WITH HIGHS FROM MID 70S TO AROUND 80
POSSIBLE AGAIN BY SUNDAY. COOLER CONDITIONS EXPECTED ACROSS PORTIONS
OF SOUTHWEST LOWER MICHIGAN WITH SWRLY LOW LEVEL COMPONENT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 144 PM EDT WED MAY 7 2014
WARM FRONT WAS CLEARING KFWA AND WILL ARRIVE AT KSBN SHORTLY
ALLOWING FOR SOUTHERLY FLOW TO SET UP. MID/HIGH CLOUDS ABOUT ALL
THAT IS AROUND FOR THE TIME BEING. WILL BE MONITORING CONVECTION
DEVELOPING ACROSS CENTRAL ILLINOIS THAT COULD DRIFT INTO THE AREA
LATER THIS AFTERNOON/EVE. SETUP NOT THE MOST FAVORABLE SO NO
MENTION IN TAFS. OTHERWISE...INCREASE IN LL MSTR WILL TAKE PLACE
TONIGHT WITH MANY OF THE HIGH RES MODELS SUGGESTING STRATUS
DEVELOPING (SOME HINTS AT EVEN IFR CIGS). NOT READY TO BUY THIS
YET WITH RUC STILL SHOWING GENERALLY CLEAR CONDITIONS SO WILL
MAINTAIN PREV FORECAST.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...FISHER
SHORT TERM...FISHER
LONG TERM...MARSILI
AVIATION...FISHER
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
152 PM EDT WED MAY 7 2014
.SYNOPSIS...
ISSUED AT 152 PM EDT WED MAY 7 2014
A WARM FRONT SHIFT QUICKLY NORTH INTO LOWER MICHIGAN BY TONIGHT.
THUNDERSTORMS ARE EXPECTED TO REMAIN WELL NORTH OF THE FRONT...
WHICH SHOULD RESULT IN DRY CONDITIONS ACROSS OUR AREA TODAY AND
TONIGHT. TEMPERATURES WILL BE WARMER... WITH HIGHS TODAY IN THE
70S OVER SOUTHERN MICHIGAN AND NORTHERN PORTIONS OF NORTHWEST
OHIO... AND IN THE LOWER TO MIDDLE 80S OVER THE REST OF THE AREA.
LOWS TONIGHT WILL RANGE FROM THE MID 50S OVER SOUTHEAST MICHIGAN
AND NORTHWEST OHIO TO THE MID 60S OVER CENTRAL INDIANA.
&&
.UPDATE...
ISSUED AT 144 PM EDT WED MAY 7 2014
FORECAST REMAINS ON TRACK FOR THE TIME BEING WITH WARM FRONT
MAKING PROGRESS NORTH ACROSS THE AREA. OBSERVATIONS INDICATE A
LOCATIONS SOMEWHERE ALONG OR JUST NORTH OF ROUTE 30 WITH A RAPID
JUMP INTO THE 70S TO NEAR 80 SOUTH IT AND TEMPS WELL NE OF THE
BOUNDARY STILL IN THE LOWER 60S.
AS MENTIONED IN PREV UPDATE...EYES WOULD BE FOCUSED ON CENTRAL
ILLINOIS BASED ON SOME OF THE HIGH RES MODELS INDICATING POSSIBLE
WIDELY SCT CONVECTION AS MISSOURI SHORT WAVE MOVES NE. RADAR
TRENDS OVER THE LAST HALF HOUR HAVE SHOWN NEW DEVELOPMENT FROM
OVER THE KILX SITE NW...WITH THIS MOVING NNE. THIS ACTIVITY IS
WELL SOUTH OF THE WARM FRONT...BUT MAY STILL BE SOMEWHAT ELEVATED
GIVEN EML IN PLACE. REGARDLESS...ADDITIONAL MONITORING WILL BE
NEEDED ACROSS THIS AREA FOR POSSIBLE WIDELY SCT CONVECTION LATER
THIS AFTERNOON. WILL MAINTAIN DRY FORECAST FOR NOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 458 AM EDT WED MAY 7 2014
HIGH PRESSURE OVER SE CANADA WILL CONTINUE TO MOVE SLOWLY EAST
TODAY ALLOWING WARM FRONT OVER KY AND SRN IN/IL TO LIFT NORTH TO
THE MI/IN-OH BORDER. BAND OF SHOWERS/TSTMS WHICH DEVELOPED IN THE
STRONG THETA-E ADVECTION REGIME NORTH OF THIS WARM FRONT FROM WI
SEWD INTO NW OH EARLY THIS MORNING WAS MOVG SLOWLY EAST WITH SOME
BACKBUILDING. THUS, THE THREAT OF CONVECTION CONTS ACROSS THE NE
PORTION OF THE CWA EARLY THIS MORNING... BUT EXPECT IT WILL END BY
12Z SO HAVE A PRE-FIRST PERIOD IN THE ZFP TO HANDLE ONGOING
ACTIVITY. REST OF THE DAY SHOULD BE RAIN-FREE ACROSS OUR AREA AS
WARM AND RELATIVELY DRY AIRMASS EVIDENT ON ILX`S 00Z SOUNDING
OVERSPREADS OUR CWA. IR SATELLITE IMAGERY SUGGESTS CONSIDERABLE
HIGH CLOUDINESS OVER OUR AREA AND UPSTREAM ACROSS IL/MO AND INTO
THE SRN PLAINS. EXPECT PARTLY SUNNY SKIES ACROSS OUR AREA TODAY
WITH MAINLY HIGH CLOUDINESS. TEMPS SHOULD RESPOND TO THE WARM
FRONT MOVING NORTH WITH HIGHS IN THE L-M80S OVER THE AREA EXCEPT
ONLY IN THE 70S OVER SRN MI AND NRN PORTIONS OF NW OH WHICH SHOULD
REMAIN NORTH OF THE FRONT.
WARM FRONT SHOULD CONT TO LIFT SLOWLY NORTH ACROSS LWR MI TONIGHT AS
A STRONG SHRTWV LIFTS NE AHEAD OF ROCKIES TROF CAUSING STNRY SFC LOW
OVER THE CENTRAL PLAINS TO LIFT NE TO ERN SD. CONVECTION
SHOULD AGAIN BE WELL NORTH OF THE FRONT AS AIRMASS TO THE SOUTH
REMAINS RELATIVELY DRY. THUS, CONTD DRY FCST FOR TONIGHT IN OUR AREA
WITH MILD LOWS RANGING FROM THE M50S NE TO THE M60S SW.
&&
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 458 AM EDT WED MAY 7 2014
VERY WARM TEMPERATURES ON TRACK FOR THURSDAY WITH 850 MB TEMPS
APPROACHING 20C PER LATEST 12KM/NAM. RAISED HIGHS A LITTLE TO COME
IN LINE WITH THE GFS/MAV WHICH APPEARS ON TRACK WITH HIGHS
APPROACHING RECORDS IN THE UPPER 80S AT FT WAYNE. THE FRONT WILL
MOVE ACROSS THE AREA FRIDAY/FRIDAY NIGHT. THE GFS AND ECMWF HAVE
COME INTO VERY GOOD AGREEMENT WITH THE TIMING OF THE FRONT...SO HAVE
ADJUSTED RAIN/STORM CHANCES ACCORDINGLY. THE BEST CHANCE FOR SEVERE
STORMS APPEARS TO BE OVER NORTHERN INDIANA LATE FRIDAY AFTERNOON
INTO EARLY FRIDAY NIGHT AHEAD OF THE FRONT WHERE LOW LEVEL
CONVERGENCE ALONG THE FRONT COMBINED WITH THE RIGHT ENTRANCE REGION
OF THE JET MAY ALLOW SOME STORMS TO BECOME SEVERE. OTHERWISE...
TEMPERATURES WILL BE COOLING BACK TO NORMAL FOR THE REST OF THE
PERIOD. THE GFS AND ECMWF RUN TO RUN CONSISTENCY CONTINUES TO BE
POOR LATE IN THE EXTENDED PERIOD...SO TRIED TO KEEP THE ONGOING
FORECAST WITHOUT MAKING MANY CHANGES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 144 PM EDT WED MAY 7 2014
WARM FRONT WAS CLEARING KFWA AND WILL ARRIVE AT KSBN SHORTLY
ALLOWING FOR SOUTHERLY FLOW TO SET UP. MID/HIGH CLOUDS ABOUT ALL
THAT IS AROUND FOR THE TIME BEING. WILL BE MONITORING CONVECTION
DEVELOPING ACROSS CENTRAL ILLINOIS THAT COULD DRIFT INTO THE AREA
LATER THIS AFTERNOON/EVE. SETUP NOT THE MOST FAVORABLE SO NO
MENTION IN TAFS. OTHERWISE...INCREASE IN LL MSTR WILL TAKE PLACE
TONIGHT WITH MANY OF THE HIGH RES MODELS SUGGESTING STRATUS
DEVELOPING (SOME HINTS AT EVEN IFR CIGS). NOT READY TO BUY THIS
YET WITH RUC STILL SHOWING GENERALLY CLEAR CONDITIONS SO WILL
MAINTAIN PREV FORECAST.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...FISHER
SYNOPSIS...JT
SHORT TERM...JT
LONG TERM...SKIPPER
AVIATION...FISHER
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AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1007 PM CDT Thu May 8 2014
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 1007 PM CDT THU MAY 8 2014
Water vapor imagery and 00Z upper air analysis indicate an upper
level trough axis transitioning eastward across the Western High
Plains. Meanwhile, another upper level trough is pushing ashore into
the Pacific Northwest. Near the surface...a cold front extends from
northeastern Kansas southwest into western Oklahoma while high
pressure builds across the Northern Plains. Cool dry air is
filtering southward into western Kansas with surface dewpoints
falling into the 30s(F).
&&
.SHORT TERM...(This evening through Friday)
ISSUED AT 329 PM CDT THU MAY 8 2014
Chances are greatest that most of the forecast area remains dry
tonight. The front has shifted far enough east that the HRRR model
solutions appear more believable than the NAM model`s solution of a
retreating dryline returning moisture and allowing moist deep
convection. The far west central Kansas counties such as Hamilton
and Stanton could see showers and isolated thunderstorms early this
evening associated with convective development over eastern
Colorado. Of the various HiRes models, the NMM cores suggest a PV
anomaly significant enough to produce showers on the backside of the
upper jet, mainly late tonight and overnight. Instability will be
minimal however and probabilities have been kept very low for the
overnight episode. Temperatures overnight should fall into the low 50s
and seen some 40s farther west where clearing is likely by 12
UTC.
Weak westerly downslope surface winds will develop on Friday as
surface high pressure spreads eastward across southeast Kansas
during the afternoon. Other than mid level clouds, mostly sunny
conditions should prevail based on model layer RH fields. The
downslope flow will promote adiabatic warming resulting in boundary
layer warm advection. Models are strongly aligned for highs in the
mid to upper 70s with only bias corrected solutions creating warmer
highs in the low 80s in the far southwest.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 314 PM CDT THU MAY 8 2014
The medium range models continue to show a strong upper level
shortwave digging into the western states this weekend and moving
out into the plains by early next week. The ECMWF, GEM and UKMET
models have all been similar and tend to be slower and deeper with
this wave. The GFS has been more open and progressive with this wave
for several runs. However, it is showing a tendency in its
operational run...as well as some of the ensemble members...to be a
little slower and deeper.
Upper level westerly flow over the central High Plains on Friday
will gradually become more southwesterly by Saturday night as the
upper wave digs into the Intermountain West. As the upper wave
approaches on Sunday, a frontal boundary should moves southward into
western Kansas with a surface low pressure system developing along
the front. There are some model differences in the position of this
front during the day Sunday. The faster GFS has it through all of
western Kansas by later in the afternoon while the other models keep
it farther west. This will have significant impacts on daytime high
temperatures as well as where the best chance for thunderstorms will
be. Given the model tendencies, will keep the front farther west
with a fairly significant temperature gradient across southwest and
south central Kansas. The models show 60 degree dewpoints spreading
northward into the central Plains ahead of this front. We could see
an outbreak of severe storms along the front during the later
afternoon and early evening hours as stronger southwesterly flow
aloft moves into western Kansas.
Chances for showers and thunderstorms will linger into Monday as the
upper trough continues to move out into the Plains but we should be
drying out by Monday night and Tuesday as the upper wave continues
east. Temperatures in Monday-Wednesday time period will be fairly
cool given the 850 millibar temperatures in the single digits.
Temperatures should moderate through the remainder of the extended
period as upper level heights build over the western and central U.S.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
ISSUED AT 629 PM CDT THU MAY 8 2014
VFR conditions will prevail with a few high clouds. Winds will
generally be from the north around 10 knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 45 78 48 82 / 20 0 0 0
GCK 43 80 47 81 / 20 0 0 0
EHA 44 80 50 85 / 30 0 0 0
LBL 45 80 48 86 / 20 0 0 0
HYS 43 78 48 80 / 10 0 0 0
P28 50 78 53 86 / 30 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Russell
LONG TERM...Gerard
AVIATION...Hovorka_42
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1002 PM CDT Thu May 8 2014
.UPDATE...
Issued at 1002 PM CDT THU MAY 8 2014
The cold front has started moving east once again and thunderstorm
development has recommenced, likely due to increased low level
convergence and possibly a weak wave lifting north along the KS/MO
state line. Thinking is that instability has weakened from
previous convection and cooling of the boundary layer. Because of
this we have allowed the watch to expire thinking the chances for
widespread severe weather will continue to diminish as the
boundary layer cools. Latest radar data suggest there could be
some small hail with the stronger updrafts, so we`ll have to
continue monitoring storms for a little while longer.
Latest water vapor imagery continues to show another shortwave now
moving into southwest KS. This wave may help some scattered
showers and thunderstorm activity to form late tonight over east
central KS. Because of this have continued with some chance pops
mainly south of I-70.
UPDATE Issued at 634 PM CDT THU MAY 8 2014
Think the cold front will continue to make steady progress east,
however outflow from recent convection seems to have masked the
true front. The latest RAP and HRRR suggest the stronger
convection could be east of the forecast area by 01Z and have
trended the forecast in this direction. As the front makes clear
progress east, will continue to clear out counties from the watch.
Main hazard remains large hail, although available instability
only around 1000 J/kg seems to be limiting the storms ability to
maintain an updraft. Low level shear parameters do not look very
supportive for much of a tornado threat.
&&
.SHORT TERM...(Through Tonight)
Issued at 252 PM CDT THU MAY 8 2014
The main focus for the short term is on the potential for
thunderstorm development, with some strong to severe storms
possible. Water vapor imagery showed the deep mid-level trough
progressing eastward into the High Plains with a swath of dry air
stretching across the western half of Kansas and the cloud cover
gradually diminishing across eastern Kansas. The main surface low
was situated over eastern Nebraska, with a secondary low developing
over western Oklahoma near the Texas panhandle. As of 19z, the radar
and surface obs showed the cold front stretching between these
surface lows being located generally along a line from Seneca to Alma
to Council Grove. Dewpoints ahead of this boundary where still in
the low/mid 60s, with drier conditions settling in behind the
boundary as dewpoints dropped into the upper 40s to upper 50s across
north central Kansas. The cloud cover along with veering winds
behind the front have limited afternoon heating with temperatures
generally in the 70s.
At 19z, radar showed a few showers and thunderstorms beginning to
initiate along this boundary over far eastern/southeast Nebraska.
Short-range models show this development continuing to spread
southward along the boundary into northeast and eastern Kansas after
20z with more scattered storm development by the 22z-00z time frame,
progressing eastward into Missouri during the evening hours. This
region looks to be favorable for the development of strong to severe
supercell thunderstorms as there is limited convective inhibition in
place. MUCAPE is modest with upwards of 1000-2000 J/kg, and there is
decent 0-6km bulk shear of 50-60kts. With the frontal passage,
soundings show some veering of the low-level winds with 0-1km bulk
shear potentially upwards of 15-20kts, so cannot rule out the
potential for a few isolated tornadoes across far eastern Kansas.
However, the main severe threat looks to be large hail with upwards
of golfball size hail possible with the stronger storms. Could also
see some damaging winds with this activity. These thunderstorms
should initially be somewhat scattered in nature, and develop more
into a line of storms by early this evening as the cold front
progresses eastward, with this main thunderstorm activity
diminishing by mid to late evening. However, additional shower and
thunderstorm develop is possible overnight across east central
Kansas as the secondary low tracks northeastward into southeast
Kansas. Expect these storms to be elevated in nature and should exit
east of the area Friday morning.
Winds will continue to veer to the west and northwest behind the
front tonight into Friday morning, with clearing skies across much
of the northwestern half of the forecast area overnight. As a
result, expect to see a spread in low temperatures tonight ranging
from the middle 40s over north central Kansas to the middle 50s
across east central Kansas due to the lingering shower and
thunderstorm activity.
.LONG TERM...(Friday through Thursday)
Issued at 252 PM CDT THU MAY 8 2014
All indications are that the main PV anomaly/trough axis will exit
the forecast area by around 15Z on Friday with a few lingering
showers or even a thunderstorm possible through that time.
Otherwise, expect downward motion and some dry advection to bring
sunshine by afternoon. The post-frontal airmass is substantially
cooler, but expect to mix up to 850 or even 800 hPa with sunshine
and westerly winds, and still expect highs to climb into the 70s.
Nearly zonal upper flow prevails into early Saturday with the front
weakening and stalling over southern KS or northern OK. Should see
dry conditions through Friday night and much of Saturday but expect
the front to return north with warm moist advection Friday night
into Saturday morning as surface low pressure develops from eastern
Colorado into the OK panhandle. So have gone warmer with Friday
night lows, and also a bit warmer on Saturday as cloud cover should
be limited and the airmass rather warm.
By Saturday afternoon, expect a negatively tilted short wave trough
to eject across the Dakotas. This storm system will have a glancing
impact on the local forecast area, but this bit of ascent will
combine with moderate to strong instability expected by Saturday
afternoon, along with a frontal boundary that will likely be
lingering in the area or drifting back south across parts of Kansas.
Expect the cap to be erased by mid to late afternoon, and the
instability in conjunction with 30 to 50 kts of 0-6 km wind shear
should result in scattered thunderstorms developing near the front.
The most likely area seems to be near/south of I-70 at this time,
and some of these storms would likely take on supercell
characteristics with at least some potential for large hail. The
wind potential will at least partially be tied to how warm
temperatures get in the warm sector...warmer equating to greater
damaging wind potential. Tornado potential seems on the low side
given current forecast parameters given expectation for somewhat
veered low level winds...but with a nearly stationary front in play,
some small potential may exist. Expect a weak embedded short wave
trough to perhaps enhance thunderstorm coverage near and even north
of the front as the low level jet intensifies after sunset. This
could allow the hail threat to persist north of the front through
the overnight hours with elevated convection.
On Sunday, expect a deep upper trough to begin to eject into the
central Plains. The surface low is expected to deepen markedly over
the OK panhandle while the surface front should remain across the
local forecast area. One of the most significant uncertainties in
the Sunday forecast regards the location of the front. The ECMWF is
strongest/farthest north with the surface low and hence has the
front extending across north central KS. The NAM...which can be
flaky with details at the end of the forecast run...is stronger with
the cold front progression and has the boundary along the boundary
by 00Z Monday. The GFS is playing middle ground at this time.
Another area of uncertainty lies in any stabilization that may occur
with any overnight/early morning convection as we`ve seen with
recent events. Wherever the boundary is located by Sunday
afternoon, the warm sector south of the front should be
characterized by strong to extreme instability and ample deep layer
wind shear. Thunderstorms are likely to develop by mid afternoon
along the front and become supercellular and severe. Low level winds
again appear to be veered a bit but still with a fair amount of low
level shear. All told, this appears to be an elevated chance for
severe storms along and south of the frontal boundary...again
focused near/south of I-70 for highest chances. The extent of storm
severity will depend on several factors that can not currently be
resolved but given magnitude of shear and instability the potential
for widespread severe is evident.
Showers and thunderstorms are expected to linger into Monday, with
the end time depending on the speed of the upper trough which
appears to be rather slow in its eastward progression. There are
indications of lingering instability into the day on Monday in
eastern KS but severe potential is questionable and quite low at
this time. The upper low is showing a fair potential to slow and
stall invof the western Great Lakes which would keep the local area
in cool NW flow for several days with a fair amount of cloud cover.
This long term forecast is rather uncertain though as even a minor
eastward shift to the upper low would bring more frequent sunshine
and temps would be quite a bit warmer.
&&
.AVIATION...(For the 00Z TAFs through 00Z Friday Evening)
Issued at 634 PM CDT THU MAY 8 2014
With the boundary apparently east of TOP and FOR, think the
chances for convection in the terminals will continue to diminish
this evening. So the forecast anticipates VFR conditions
prevailing as northwest winds bring dryer air into the area.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Wolters
SHORT TERM...Hennecke
LONG TERM...Barjenbruch
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS TOPEKA KS
635 PM CDT Thu May 8 2014
.UPDATE...
Issued at 634 PM CDT THU MAY 8 2014
Think the cold front will continue to make steady progress east,
however outflow from recent convection seems to have masked the
true front. The latest RAP and HRRR suggest the stronger
convection could be east of the forecast area by 01Z and have
trended the forecast in this direction. As the front makes clear
progress east, will continue to clear out counties from the watch.
Main hazard remains large hail, although available instability
only around 1000 J/kg seems to be limiting the storms ability to
maintain an updraft. Low level shear parameters do not look very
supportive for much of a tornado threat.
&&
.SHORT TERM...(Through Tonight)
Issued at 252 PM CDT THU MAY 8 2014
The main focus for the short term is on the potential for
thunderstorm development, with some strong to severe storms
possible. Water vapor imagery showed the deep mid-level trough
progressing eastward into the High Plains with a swath of dry air
stretching across the western half of Kansas and the cloud cover
gradually diminishing across eastern Kansas. The main surface low
was situated over eastern Nebraska, with a secondary low developing
over western Oklahoma near the Texas panhandle. As of 19z, the radar
and surface obs showed the cold front stretching between these
surface lows being located generally along a line from Seneca to Alma
to Council Grove. Dewpoints ahead of this boundary where still in
the low/mid 60s, with drier conditions settling in behind the
boundary as dewpoints dropped into the upper 40s to upper 50s across
north central Kansas. The cloud cover along with veering winds
behind the front have limited afternoon heating with temperatures
generally in the 70s.
At 19z, radar showed a few showers and thunderstorms beginning to
initiate along this boundary over far eastern/southeast Nebraska.
Short-range models show this development continuing to spread
southward along the boundary into northeast and eastern Kansas after
20z with more scattered storm development by the 22z-00z time frame,
progressing eastward into Missouri during the evening hours. This
region looks to be favorable for the development of strong to severe
supercell thunderstorms as there is limited convective inhibition in
place. MUCAPE is modest with upwards of 1000-2000 J/kg, and there is
decent 0-6km bulk shear of 50-60kts. With the frontal passage,
soundings show some veering of the low-level winds with 0-1km bulk
shear potentially upwards of 15-20kts, so cannot rule out the
potential for a few isolated tornadoes across far eastern Kansas.
However, the main severe threat looks to be large hail with upwards
of golfball size hail possible with the stronger storms. Could also
see some damaging winds with this activity. These thunderstorms
should initially be somewhat scattered in nature, and develop more
into a line of storms by early this evening as the cold front
progresses eastward, with this main thunderstorm activity
diminishing by mid to late evening. However, additional shower and
thunderstorm develop is possible overnight across east central
Kansas as the secondary low tracks northeastward into southeast
Kansas. Expect these storms to be elevated in nature and should exit
east of the area Friday morning.
Winds will continue to veer to the west and northwest behind the
front tonight into Friday morning, with clearing skies across much
of the northwestern half of the forecast area overnight. As a
result, expect to see a spread in low temperatures tonight ranging
from the middle 40s over north central Kansas to the middle 50s
across east central Kansas due to the lingering shower and
thunderstorm activity.
.LONG TERM...(Friday through Thursday)
Issued at 252 PM CDT THU MAY 8 2014
All indications are that the main PV anomaly/trough axis will exit
the forecast area by around 15Z on Friday with a few lingering
showers or even a thunderstorm possible through that time.
Otherwise, expect downward motion and some dry advection to bring
sunshine by afternoon. The post-frontal airmass is substantially
cooler, but expect to mix up to 850 or even 800 hPa with sunshine
and westerly winds, and still expect highs to climb into the 70s.
Nearly zonal upper flow prevails into early Saturday with the front
weakening and stalling over southern KS or northern OK. Should see
dry conditions through Friday night and much of Saturday but expect
the front to return north with warm moist advection Friday night
into Saturday morning as surface low pressure develops from eastern
Colorado into the OK panhandle. So have gone warmer with Friday
night lows, and also a bit warmer on Saturday as cloud cover should
be limited and the airmass rather warm.
By Saturday afternoon, expect a negatively tilted short wave trough
to eject across the Dakotas. This storm system will have a glancing
impact on the local forecast area, but this bit of ascent will
combine with moderate to strong instability expected by Saturday
afternoon, along with a frontal boundary that will likely be
lingering in the area or drifting back south across parts of Kansas.
Expect the cap to be erased by mid to late afternoon, and the
instability in conjunction with 30 to 50 kts of 0-6 km wind shear
should result in scattered thunderstorms developing near the front.
The most likely area seems to be near/south of I-70 at this time,
and some of these storms would likely take on supercell
characteristics with at least some potential for large hail. The
wind potential will at least partially be tied to how warm
temperatures get in the warm sector...warmer equating to greater
damaging wind potential. Tornado potential seems on the low side
given current forecast parameters given expectation for somewhat
veered low level winds...but with a nearly stationary front in play,
some small potential may exist. Expect a weak embedded short wave
trough to perhaps enhance thunderstorm coverage near and even north
of the front as the low level jet intensifies after sunset. This
could allow the hail threat to persist north of the front through
the overnight hours with elevated convection.
On Sunday, expect a deep upper trough to begin to eject into the
central Plains. The surface low is expected to deepen markedly over
the OK panhandle while the surface front should remain across the
local forecast area. One of the most significant uncertainties in
the Sunday forecast regards the location of the front. The ECMWF is
strongest/farthest north with the surface low and hence has the
front extending across north central KS. The NAM...which can be
flaky with details at the end of the forecast run...is stronger with
the cold front progression and has the boundary along the boundary
by 00Z Monday. The GFS is playing middle ground at this time.
Another area of uncertainty lies in any stabilization that may occur
with any overnight/early morning convection as we`ve seen with
recent events. Wherever the boundary is located by Sunday
afternoon, the warm sector south of the front should be
characterized by strong to extreme instability and ample deep layer
wind shear. Thunderstorms are likely to develop by mid afternoon
along the front and become supercellular and severe. Low level winds
again appear to be veered a bit but still with a fair amount of low
level shear. All told, this appears to be an elevated chance for
severe storms along and south of the frontal boundary...again
focused near/south of I-70 for highest chances. The extent of storm
severity will depend on several factors that can not currently be
resolved but given magnitude of shear and instability the potential
for widespread severe is evident.
Showers and thunderstorms are expected to linger into Monday, with
the end time depending on the speed of the upper trough which
appears to be rather slow in its eastward progression. There are
indications of lingering instability into the day on Monday in
eastern KS but severe potential is questionable and quite low at
this time. The upper low is showing a fair potential to slow and
stall invof the western Great Lakes which would keep the local area
in cool NW flow for several days with a fair amount of cloud cover.
This long term forecast is rather uncertain though as even a minor
eastward shift to the upper low would bring more frequent sunshine
and temps would be quite a bit warmer.
&&
.AVIATION...(For the 00Z TAFs through 00Z Friday Evening)
Issued at 634 PM CDT THU MAY 8 2014
With the boundary apparently east of TOP and FOR, think the
chances for convection in the terminals will continue to diminish
this evening. So the forecast anticipates VFR conditions
prevailing as northwest winds bring dryer air into the area.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...Wolters
SHORT TERM...Hennecke
LONG TERM...Barjenbruch
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
630 PM CDT Thu May 8 2014
...Updated aviation section...
.SHORT TERM...(This evening through Friday)
ISSUED AT 329 PM CDT THU MAY 8 2014
Chances are greatest that most of the forecast area remains dry
tonight. The front has shifted far enough east that the HRRR model
solutions appear more believable than the NAM model`s solution of a
retreating dryline returning moisture and allowing moist deep
convection. The far west central Kansas counties such as Hamilton
and Stanton could see showers and isolated thunderstorms early this
evening associated with convective development over eastern
Colorado. Of the various HiRes models, the NMM cores suggest a PV
anomaly significant enough to produce showers on the backside of the
upper jet, mainly late tonight and overnight. Instability will be
minimal however and probabilities have been kept very low for the
overnight episode. Temperatures overnight should fall into the low 50s
and seen some 40s farther west where clearing is likely by 12
UTC.
Weak westerly downslope surface winds will develop on Friday as
surface high pressure spreads eastward across southeast Kansas
during the afternoon. Other than mid level clouds, mostly sunny
conditions should prevail based on model layer RH fields. The
downslope flow will promote adiabatic warming resulting in boundary
layer warm advection. Models are strongly aligned for highs in the
mid to upper 70s with only bias corrected solutions creating warmer
highs in the low 80s in the far southwest.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 314 PM CDT THU MAY 8 2014
The medium range models continue to show a strong upper level
shortwave digging into the western states this weekend and moving
out into the plains by early next week. The ECMWF, GEM and UKMET
models have all been similar and tend to be slower and deeper with
this wave. The GFS has been more open and progressive with this wave
for several runs. However, it is showing a tendency in its
operational run...as well as some of the ensemble members...to be a
little slower and deeper.
Upper level westerly flow over the central High Plains on Friday
will gradually become more southwesterly by Saturday night as the
upper wave digs into the Intermountain West. As the upper wave
approaches on Sunday, a frontal boundary should moves southward into
western Kansas with a surface low pressure system developing along
the front. There are some model differences in the position of this
front during the day Sunday. The faster GFS has it through all of
western Kansas by later in the afternoon while the other models keep
it farther west. This will have significant impacts on daytime high
temperatures as well as where the best chance for thunderstorms will
be. Given the model tendencies, will keep the front farther west
with a fairly significant temperature gradient across southwest and
south central Kansas. The models show 60 degree dewpoints spreading
northward into the central Plains ahead of this front. We could see
an outbreak of severe storms along the front during the later
afternoon and early evening hours as stronger southwesterly flow
aloft moves into western Kansas.
Chances for showers and thunderstorms will linger into Monday as the
upper trough continues to move out into the Plains but we should be
drying out by Monday night and Tuesday as the upper wave continues
east. Temperatures in Monday-Wednesday time period will be fairly
cool given the 850 millibar temperatures in the single digits.
Temperatures should moderate through the remainder of the extended
period as upper level heights build over the western and central U.S.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
ISSUED AT 629 PM CDT THU MAY 8 2014
VFR conditions will prevail with a few high clouds. Winds will
generally be from the north around 10 knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 45 77 48 82 / 20 0 0 0
GCK 43 78 47 81 / 20 0 0 0
EHA 44 79 50 85 / 20 0 0 0
LBL 45 80 48 86 / 10 0 0 0
HYS 43 78 48 80 / 10 10 0 0
P28 50 78 53 86 / 30 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Russell
SHORT TERM...Russell
LONG TERM...Gerard
AVIATION...Hovorka_42
AREA FORECAST DISCUSSION
NWS TOPEKA KS
515 PM CDT Wed May 7 2014
...AVIATION UPDATE...
.SHORT TERM...(This Evening through Thursday)
Issued at 304 PM CDT WED MAY 7 2014
Tonight through Thursday ...
Water vapor imagery showed the deep mid-level trough stretched
across the western U.S. with southwesterly flow aloft over the
Central Plains. At the surface, low pressure stretched across
southwest to north central Kansas with the dryline nearly bisecting
the state from north to south at 20z. With a tight pressure gradient
in place across much of the region, south-southwesterly winds were
gusting upwards of 25-35mph this afternoon, which aided in decent
WAA as well as moisture advection across eastern Kansas with
dewpoints reaching into the lower to middle 60s. It was another mild
day across the region as high temperatures rose into the upper
80s/low 90s across eastern Kansas and into the mid/upper 90s over
north central Kansas. The warmest conditions across north central
Kansas were co-located with the drier conditions as dewpoints
plunged as low as into the middle 30s, resulting in RH values
dropping into the teens. These dry conditions combined with the
breezy winds will keep very high fire danger concerns in place
through early this evening, so a Red Flag Warning remains in effect
through 8pm across portions of north central Kansas.
Visible satellite this afternoon showed a few storms popping up
across northern Texas/southern Oklahoma along the dryline. The last
few runs of the HRRR/RAP have shown good run-to-run consistency as
well as good agreement with each other regarding the current
mid-afternoon development and additional northward development of
showers and thunderstorms along this dryline this evening. This
initial thunderstorm development looks to be supported by a
mid-level shortwave, and as this wave tracks northward into the area
this evening it will help to provide enhanced lift over the region.
Model soundings show the cap eroding away this afternoon across the
central portions of the forecast area (roughly from Council Grove
northward toward Manhattan), with short-range models showing this
region being well-primed for scattered thunderstorm development,
beginning between 22z-00z. MLCAPE values in this region could be
upwards of 2000-3000 J/kg with upwards of 20-30kts of 0-6km bulk
shear. As a result, the stronger storms may be capable of producing
large hail and possibly some stronger wind gusts later this evening
as the LLJ increases over the region. This activity should diminish
overnight with the loss of diurnal heating. Southerly winds will
remain breezy overnight due to the aforementioned increasing LLJ, so
this strong southerly flow combined with increasing mid-level cloud
cover will keep low temperatures tonight mild in the middle 60s west
to upper 60s/near 70 east.
There is the potential for strong to severe thunderstorms once again
on Thursday as the mid-level trough ejects into the Central Plains,
finally pushing the cold front associated with this system eastward
across the area by Thursday night. 12z model runs have come into
better agreement with the timing of this frontal passage and the
eastward progression of the dryline through the day. Latest model
trends show any morning precipitation to be focused across far
eastern Kansas, but there are discrepancies with the coverage of
this activity. Feel that this activity should be fairly limited,
which would lead to more time for the environment to recover to
support redevelopment of thunderstorms along the dryline during the
afternoon hours. While there are still some minor discrepancies with
the exact placement of the dryline by the afternoon, thunderstorm
initiation looks to occur somewhere between Abilene and Manhattan
and between 18z-21z. The cap looks to quickly weaken during the
early/mid afternoon hours with upwards of 1500-2000 J/kg of MUCAPE and
45-55kts of 0-6km bulk shear. While there certainly looks to be
decent shear in place, it looks to be fairly unidirectional. The
main threats with the strongest storms will be large hail and
damaging winds, but cannot rule out the potential for a few isolated
tornadoes. The increasing mid-level cloud cover will limit the
daytime heating with Thursday highs likely reaching into the middle
70s to low 80s.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 304 PM CDT WED MAY 7 2014
Extended focus will be on impacts of first system Thursday night
and second system over the weekend.
Thurs Night...ongoing convection should become focused across east
central Kansas as convergence is maximized along the north side of
a secondary surface low and boundary so will keep high precip chcs across
that area. Much cooler and drier air will arrive for Friday with
highs back toward average in the lower 70s with dewpoints in the 40s.
The next longwave trough will begin to take shape across the
Rockies by Saturday with sfc low pressure forecast to develop
across southeast Colorado. Moisture advection along and north of
the developing warm front could result in SCT convection so will
leave low pops on Sat. Better chances for showers and t-storms
will arrive Saturday night into Sunday as the sfc low sags into
western OK and the associated sfc front also sags south. It would
appear that given moisture and shear that Sunday could bring a
risk for severe storms but that is dependent on details of front
position so confidence in severe risk Sunday is low at the moment.
Overall confidence in weather trends is higher by Monday so look for a
wet and colder start to the next work week with precip chcs decreasing
Monday night and ending by Tuesday. Temps next week should remain
near Average of 70 to 75.
&&
.AVIATION...(For the 00Z TAFs through 00Z Thursday Evening)
Issued at 515 PM CDT WED MAY 7 2014
Amended the TAFs to remove the TEMPO for TS at TOP and FOE. Latest
RAP and NAM show the axis of instability remaining fairly close to
the dryline with larger amounts of CIN to the east. Therefore
confidence in TS moving into the terminals is to low to keep a
tempo. MHK conversely is just east of the dryline with some
convection bubbling up to the southwest. Therefore will keep the
tempo, but have shortened the duration of the tempo based on the
latest HRRR prog of convection. Also backed off on the MVFR CIGS
for Thursday morning. Don`t see a huge increase in low level
moisture so am not sure why the NAM is saturating the boundary
layer. The RAP fails to saturate the boundary layer so am
skeptical of a CIG and will just mention a SCT deck possible at
TOP and FOE Thursday morning.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING until 8 PM CDT this evening FOR KSZ008-009-020-
021-034-035.
&&
$$
SHORT TERM...Hennecke
LONG TERM...Omitt
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS GOODLAND KS
147 PM MDT WED MAY 7 2014
.UPDATE...
ISSUED AT 1048 AM MDT WED MAY 7 2014
ISSUED A WIND ADVISORY FOR THE SOUTHERNMOST SIX COUNTIES FOR LATER
THIS AFTERNOON THROUGH EARLY EVENING. DEEP MIXING SHOULD ALLOW FOR
GUSTS TO REACH 45 MPH IN THIS AREA. STILL SOME UNCERTAINTY HOW FAR
NORTH STRONGER WINDS WILL DEVELOP BUT THE GREATEST THREAT OF
ADVISORY CRITERIA WINDS SHOULD STAY SOUTH OF INTERSTATE 70.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 225 AM MDT WED MAY 7 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW DEEPENING TROUGH
CURRENTLY CENTERED OVER THE GREAT BASIN WITH SW FLOW EXTENDING
ACROSS CENTRAL ROCKIES AND PLAINS. AT THE SURFACE LOW PRESSURE
CURRENTLY EXTENDS FROM EAST CENTRAL COLORADO ACROSS THE TRI STATE
REGION WITH A STATIONARY FRONT BISECTING THIS FEATURE GENERALLY
ALONG AND SOUTH OF INTERSTATE 70. A DRY LINE EXTENDING ACROSS CENTRAL
KS HAS BEEN BACKING UP TOWARDS THE EASTERN PART OF OUR CWA.
PARTICULARLY LOW CONFIDENCE IN FORECAST FOR TODAY AS A RESULT OF THE
LINGERING STATIONARY FRONT AND INCONSISTENCIES BETWEEN GUIDANCE ON
EVOLUTION OF SURFACE LOW AND FRONT TIMING AS UPPER TROUGH SHIFTS
EAST INTO THE PLAINS. THIS IS A REFLECTION OF MODEL DIFFERENCES ON
EVOLUTION/TRACK OF CLOSED H5/H7 LOW CENTERS ACROSS THE PLAINS
TODAY/TONIGHT. WE COULD SEE WIDE RANGING IMPACTS DEPENDING ON ALL OF
THE ABOVE MENTIONED VARIANCES ON BOTH OUR RFW...A POSSIBLE WIND
ADVISORY...AND POTENTIAL SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE
NORTHERN HALF OF OUR CWA. THERE IS SO MUCH SPREAD BETWEEN MODELS
FROM THE I-70 CORRIDOR NORTH ALL I WAS UNCOMFORTABLE DOING MORE THAN
NUDGING TOWARDS THE LATEST BLENDS/NAM TRENDS. THIS PUTS THE SE HALF
OF OUR CWA NEAR WIND ADVISORY CRITERIA...AND ANOTHER ROW OF COUNTIES
WITHIN RFW CRITERIA. REGARDING THE CURRENT RFW AND POSSIBLE WIND
ADVISORY...CONFIDENCE IS JUST TOO LOW TO MAKE HIGHLIGHT CHANGES.
BASED ON EVOLUTION OF SURFACE FEATURES WE COULD SEE THUNDERSTORM
INITIATION AND SEVERE POTENTIAL BY MIDDAY FURTHER SOUTH (I-70
CORRIDOR) BEFORE ANY PRIMARY THUNDERSTORM CHANCES TRANSITION NORTH
AND WEST. WE WILL NEED TO MONITOR AND ADJUST AS CONFIDENCE INCREASE
BASED ON REAL TIME DATA AND NEW RUNS OF SHORT RANGE GUIDANCE TO GET
A BETTER HANDLE ON SENSIBLE WEATHER OVER OUR CWA THROUGH THIS
EVENING.
AS UPPER LOW TRANSITIONS EAST A COLD FRONT EVENTUALLY WILL PUSH SOUTH
TONIGHT BEFORE STALLING ACROSS THE SOUTHERN PART OF OUR CWA. BESIDES
COMPLICATING THE TEMP FORECAST...THIS FEATURE COULD ACT AS A FOCUS FOR
ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT AS A SECONDARY SHORTWAVE
TROUGH MOVES ACROSS THE NORTHERN PLAINS BEHIND THE INITIAL UPPER
LOW. I USED A CONSENSUS BLEND OF TEMPS THROUGH FRI AND LINGERED POPS
THROUGH FRI NIGHT TO ACCOUNT FOR LIFT/MOISTURE ALONG FRONT AND
ASSOCIATE WITH WEAK TROUGH PASSAGE. WHILE TEMPS SHOULD RETURN TO
NEAR SEASONAL VALUES...IT DOES LOOK LIKE WE HAVE POTENTIAL FOR LOW
TEMPS TO DROP WELL BELOW NORMAL IN THE 30S...AND ACTUALLY WITHIN
FROST ADVISORY CRITERIA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 135 PM MDT WED MAY 7 2014
TROUGH AXIS WILL BE MOVING EAST AND OUT OF THE AREA THURSDAY NIGHT
WITH PRECIPITATION CHANCES DIMINISHING. CLEARING SKIES AND LIGHT
WEST TO NORTHWEST WINDS WILL ALLOW TEMPERATURES TO DROP INTO THE
UPPER 30S TO LOWER 40S...JUST ABOVE FROST ADVISORY CRITERIA.
WEAK SHORTWAVE TROUGH EMBEDDED IN THE ZONAL FLOW ON FRIDAY
AFTERNOON AND EVENING WILL BRING LOW CHANCES FOR RAIN
SHOWERS IN NORTHEAST COLORADO AND THE NEBRASKA BORDER AREA...BUT
WITH MUCAPE FORECAST TO BE ZERO DID NOT INCLUDE ANY MENTION OF
THUNDER. TEMPERATURES WILL BE NEAR NORMAL...WITH LOWS FRIDAY NIGHT
WELL ABOVE FROST CRITERIA.
ZONAL FLOW ALOFT CONTINUES THROUGH THE REMAINDER OF THE EXTENDED
PERIOD...WITH OCCASIONAL CHANCES FOR PRECIPITATION. BEST CHANCES
APPEAR TO BE BETWEEN SATURDAY NIGHT AND MONDAY WITH A BETTER
DEFINED SHORTWAVE TROUGH IN THE FLOW. THERE ARE SOME CONSIDERABLE
TIMING DIFFERENCES AMONG THE MODELS SO DID NOT GET TOO SPECIFIC.
THE COMBINATION OF CLOUDS AND COLD ADVECTION AT THE SURFACE WILL
RESULT IN BELOW NORMAL TEMPERATURES. MUCAPE IS NEAR ZERO OR VERY
LOW SO DO NOT HAVE ANY MENTION OF THUNDER UNTIL VERY LATE IN THE
PERIOD WHEN MODELS HINT AT SOME WEAK INSTABILITY. WET BULB ZERO
HEIGHTS SUGGEST A RAIN/SNOW MIX POSSIBLE SUNDAY AND MONDAY IN THE
HIGHER TERRAIN OF THE WESTERN FORECAST AREA...BUT NO ACCUMULATION
IS EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1142 AM MDT WED MAY 7 2014
VFR CONDITIONS ARE EXPECTED AT BOTH TERMINALS THROUGH THE PERIOD.
THE WIND FORECAST IS QUITE CHALLENGING AND MAY REQUIRE AMENDMENTS
THIS AFTERNOON. NORTHEASTERLY WINDS BEHIND A WEAK NEARLY
STATIONARY FRONT HAVE PERSISTED THROUGH THE MORNING BUT SHOULD
GRADUALLY TRANSITION TO SOUTHERLY AT GLD AS THE FRONT MOVES
NORTHWARD. WINDS COULD BECOME GUSTY THIS AFTERNOON...ESPECIALLY
AFTER 21Z LASTING INTO THE EARLY EVENING. AT KMCK WINDS ARE EXPECTED TO
REMAIN EASTERLY/NORTHEASTERLY THROUGH THE FIRST PART OF THE NIGHT.
AT BOTH TERMINALS A COLD FRONT WILL MOVE THROUGH LATE RESULTING IN
A SHIFT TO NORTHWESTERLY WINDS...WITH GUSTS 30-35 KNOTS
POSSIBLE...ESPECIALLY BY MID MORNING. THUNDERSTORMS WILL LIKELY
FORM NORTH OF THE BOUNDARY LATE THIS AFTERNOON AND EVENING. THE
GREATEST CHANCES WILL BE NORTHWEST OF BOTH TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR
KSZ013>016-027>029-041-042.
WIND ADVISORY UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR
KSZ027>029-041-042.
CO...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ253-254.
WIND ADVISORY UNTIL 9 PM MDT THIS EVENING FOR COZ092.
NE...NONE.
&&
$$
UPDATE...BRB
SHORT TERM...DR
LONG TERM...024
AVIATION...BRB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1142 AM MDT WED MAY 7 2014
.UPDATE...
ISSUED AT 1048 AM MDT WED MAY 7 2014
ISSUED A WIND ADVISORY FOR THE SOUTHERNMOST SIX COUNTIES FOR LATER
THIS AFTERNOON THROUGH EARLY EVENING. DEEP MIXING SHOULD ALLOW FOR
GUSTS TO REACH 45 MPH IN THIS AREA. STILL SOME UNCERTAINTY HOW FAR
NORTH STRONGER WINDS WILL DEVELOP BUT THE GREATEST THREAT OF
ADVISORY CRITERIA WINDS SHOULD STAY SOUTH OF INTERSTATE 70.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 225 AM MDT WED MAY 7 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW DEEPENING TROUGH
CURRENTLY CENTERED OVER THE GREAT BASIN WITH SW FLOW EXTENDING
ACROSS CENTRAL ROCKIES AND PLAINS. AT THE SURFACE LOW PRESSURE
CURRENTLY EXTENDS FROM EASTCENTRAL COLORADO ACROSS THE TRI STATE
REGION WITH A STATIONARY FRONT BISECTING THIS FEATURE GENERALLY
ALONG AND SOUTH OF INTERSTATE 70. A DRY LINE EXTENDING ACROSS CENTRAL
KS HAS BEEN BACKING UP TOWARDS THE EASTERN PART OF OUR CWA.
PARTICULARLY LOW CONFIDENCE IN FORECAST FOR TODAY AS A RESULT OF THE
LINGERING STATIONARY FRONT AND INCONSISTENCIES BETWEEN GUIDANCE ON
EVOLUTION OF SURFACE LOW AND FRONT TIMING AS UPPER TROUGH SHIFTS
EAST INTO THE PLAINS. THIS IS A REFLECTION OF MODEL DIFFERENCES ON
EVOLUTION/TRACK OF CLOSED H5/H7 LOW CENTERS ACROSS THE PLAINS
TODAY/TONIGHT. WE COULD SEE WIDE RANGING IMPACTS DEPENDING ON ALL OF
THE ABOVE MENTIONED VARIANCES ON BOTH OUR RFW...A POSSIBLE WIND
ADVISORY...AND POTENTIAL SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE
NORTHERN HALF OF OUR CWA. THERE IS SO MUCH SPREAD BETWEEN MODELS
FROM THE I-70 CORRIDOR NORTH ALL I WAS UNCOMFORTABLE DOING MORE THAN
NUDGING TOWARDS THE LATEST BLENDS/NAM TRENDS. THIS PUTS THE SE HALF
OF OUR CWA NEAR WIND ADVISORY CRITERIA...AND ANOTHER ROW OF COUNTIES
WITHIN RFW CRITERIA. REGARDING THE CURRENT RFW AND POSSIBLE WIND
ADVISORY...CONFIDENCE IS JUST TOO LOW TO MAKE HIGHLIGHT CHANGES.
BASED ON EVOLUTION OF SURFACE FEATURES WE COULD SEE THUNDERSTORM
INITIATION AND SEVERE POTENTIAL BY MIDDAY FURTHER SOUTH (I-70
CORRIDOR) BEFORE ANY PRIMARY THUNDERSTORM CHANCES TRANSITION NORTH
AND WEST. WE WILL NEED TO MONITOR AND ADJUST AS CONFIDENCE INCREASE
BASED ON REAL TIME DATA AND NEW RUNS OF SHORT RANGE GUIDANCE TO GET
A BETTER HANDLE ON SENSIBLE WEATHER OVER OUR CWA THROUGH THIS
EVENING.
AS UPPER LOW TRANSITIONS EAST A COLD FRONT EVENTUALLY WILL PUSH SOUTH
TONIGHT BEFORE STALLING ACROSS THE SOUTHERN PART OF OUR CWA. BESIDES
COMPLICATING THE TEMP FORECAST...THIS FEATURE COULD ACT AS A FOCUS FOR
ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT AS A SECONDARY SHORTWAVE
TROUGH MOVES ACROSS THE NORTHERN PLAINS BEHIND THE INITIAL UPPER
LOW. I USED A CONSENSUS BLEND OF TEMPS THROUGH FRI AND LINGERED POPS
THROUGH FRI NIGHT TO ACCOUNT FOR LIFT/MOISTURE ALONG FRONT AND
ASSOCIATE WITH WEAK TROUGH PASSAGE. WHILE TEMPS SHOULD RETURN TO
NEAR SEASONAL VALUES...IT DOES LOOK LIKE WE HAVE POTENTIAL FOR LOW
TEMPS TO DROP WELL BELOW NORMAL IN THE 30S...AND ACTUALLY WITHIN
FROST ADVISORY CRITERIA.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 215 AM MDT WED MAY 7 2014
WESTERLY ZONAL FLOW ALOFT WILL BE PRESENT ACROSS THE HIGH PLAINS
SATURDAY...WHICH WILL BRING BENIGN CONDITIONS ACROSS THE FORECAST
AREA. A POSITIVELY TILTED UPPER LEVEL TROUGH WILL BEGIN TO MOVE INTO
THE GREAT BASIN REGION AND CONTINUE TO PROGRESS INTO THE TRI STATE
AREA SATURDAY NIGHT. MODEL RUNS DIFFER AS TO THE LOCATION OF THE
ENSUING TROUGH AS WELL AS THE TIMING OF THE PASSAGE OF THE TROUGH
AXIS THROUGH THE REGION...BUT THIS WEATHER MAKING SYSTEM SHOULD
AFFECT THE AREA SOMETIME BETWEEN THE SATURDAY NIGHT TO MONDAY NIGHT
TIME FRAME. MOST MODEL FORECASTS INDICATE A SHORTWAVE RIDGE WILL
MOVE INTO THE HIGH PLAINS ONCE THE TROUGH AXIS MOVES EASTWARD ON
TUESDAY...BUT THE GEM MODEL HAS THE UPPER LEVEL LOW SYSTEM BECOMING
CUT OFF OVER THE HIGH PLAINS REGION. TENDED TO SIDE WITH THE DRY
FORECAST AS THE ECMWF...GFS AND DGEX FORECASTS INDICATE THE RIDGE.
THE MAIN CONCERN FOR THE LONG TERM FORECAST PERIOD WILL BE THE
CHANCES FOR THUNDERSTORMS SATURDAY NIGHT THROUGH MONDAY.
THUNDERSTORMS AND PRECIPITATION CHANCES MAY LINGER INTO TUESDAY IF
THE FLOW ALOFT BECOMES CUT OFF...WHICH WILL AID IN MORE
PRECIPITATION PRODUCTION. LATEST MODEL FORECASTS PLACE THE GREATEST
MID AND LOWER LEVEL JET SPEEDS AND HIGHEST AREAS OF INSTABILITY WELL
TO THE EAST OF THE FORECAST AREA FOR THE PERIOD FOR GREATEST
PRECIPITATION POTENTIAL...SO THUNDERSTORM ACTIVITY IS NOT EXPECTED
TO BECOME SEVERE.
DUE TO THE ZONAL FLOW PATTERN SATURDAY FOLLOWED BY A PUSH OF COOLER
AIR ALOFT WITH THE TROUGH PATTERN...TEMPERATURES THROUGH THE LONG
TERM PERIOD WILL BE NEAR TO SLIGHTLY BELOW NORMAL WITH HIGHS
GENERALLY IN THE MID 60S TO LOWER 70S. LOW TEMPERATURES WILL SPAN
DURING THIS PERIOD BETWEEN THE LOW TO UPPER 40S...WITH SOME SPOTS IN
EASTERN COLORADO DIPPING INTO THE UPPER 30S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1142 AM MDT WED MAY 7 2014
VFR CONDITIONS ARE EXPECTED AT BOTH TERMINALS THROUGH THE PERIOD.
THE WIND FORECAST IS QUITE CHALLENGING AND MAY REQUIRE AMENDMENTS
THIS AFTERNOON. NORTHEASTERLY WINDS BEHIND A WEAK NEARLY
STATIONARY FRONT HAVE PERSISTED THROUGH THE MORNING BUT SHOULD
GRADUALLY TRANSITION TO SOUTHERLY AT GLD AS THE FRONT MOVES
NORTHWARD. WINDS COULD BECOME GUSTY THIS AFTERNOON...ESPECIALLY
AFTER 21Z LASTING INTO THE EARLY EVENING. AT KMCK WINDS ARE EXPECTED TO
REMAIN EASTERLY/NORTHEASTERLY THROUGH THE FIRST PART OF THE NIGHT.
AT BOTH TERMINALS A COLD FRONT WILL MOVE THROUGH LATE RESULTING IN
A SHIFT TO NORTHWESTERLY WINDS...WITH GUSTS 30-35 KNOTS
POSSIBLE...ESPECIALLY BY MID MORNING. THUNDERSTORMS WILL LIKELY
FORM NORTH OF THE BOUNDARY LATE THIS AFTERNOON AND EVENING. THE
GREATEST CHANCES WILL BE NORTHWEST OF BOTH TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR
KSZ013>016-027>029-041-042.
WIND ADVISORY FROM 3 PM MDT /4 PM CDT/ THIS AFTERNOON TO 9 PM
MDT /10 PM CDT/ THIS EVENING FOR KSZ027>029-041-042.
CO...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ253-254.
WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 9 PM MDT THIS EVENING
FOR COZ092.
NE...NONE.
&&
$$
UPDATE...BRB
SHORT TERM...DR
LONG TERM...MK
AVIATION...BRB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1050 AM MDT WED MAY 7 2014
.UPDATE...
ISSUED AT 1048 AM MDT WED MAY 7 2014
ISSUED A WIND ADVISORY FOR THE SOUTHERNMOST SIX COUNTIES FOR LATER
THIS AFTERNOON THROUGH EARLY EVENING. DEEP MIXING SHOULD ALLOW FOR
GUSTS TO REACH 45 MPH IN THIS AREA. STILL SOME UNCERTAINTY HOW FAR
NORTH STRONGER WINDS WILL DEVELOP BUT THE GREATEST THREAT OF
ADVISORY CRITERIA WINDS SHOULD STAY SOUTH OF INTERSTATE 70.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 225 AM MDT WED MAY 7 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW DEEPENING TROUGH
CURRENTLY CENTERED OVER THE GREAT BASIN WITH SW FLOW EXTENDING
ACROSS CENTRAL ROCKIES AND PLAINS. AT THE SURFACE LOW PRESSURE
CURRENTLY EXTENDS FROM EASTCENTRAL COLORADO ACROSS THE TRI STATE
REGION WITH A STATIONARY FRONT BISECTING THIS FEATURE GENERALLY
ALONG AND SOUTH OF INTERSTATE 70. A DRY LINE EXTENDING ACROSS CENTRAL
KS HAS BEEN BACKING UP TOWARDS THE EASTERN PART OF OUR CWA.
PARTICULARLY LOW CONFIDENCE IN FORECAST FOR TODAY AS A RESULT OF THE
LINGERING STATIONARY FRONT AND INCONSISTENCIES BETWEEN GUIDANCE ON
EVOLUTION OF SURFACE LOW AND FRONT TIMING AS UPPER TROUGH SHIFTS
EAST INTO THE PLAINS. THIS IS A REFLECTION OF MODEL DIFFERENCES ON
EVOLUTION/TRACK OF CLOSED H5/H7 LOW CENTERS ACROSS THE PLAINS
TODAY/TONIGHT. WE COULD SEE WIDE RANGING IMPACTS DEPENDING ON ALL OF
THE ABOVE MENTIONED VARIANCES ON BOTH OUR RFW...A POSSIBLE WIND
ADVISORY...AND POTENTIAL SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE
NORTHERN HALF OF OUR CWA. THERE IS SO MUCH SPREAD BETWEEN MODELS
FROM THE I-70 CORRIDOR NORTH ALL I WAS UNCOMFORTABLE DOING MORE THAN
NUDGING TOWARDS THE LATEST BLENDS/NAM TRENDS. THIS PUTS THE SE HALF
OF OUR CWA NEAR WIND ADVISORY CRITERIA...AND ANOTHER ROW OF COUNTIES
WITHIN RFW CRITERIA. REGARDING THE CURRENT RFW AND POSSIBLE WIND
ADVISORY...CONFIDENCE IS JUST TOO LOW TO MAKE HIGHLIGHT CHANGES.
BASED ON EVOLUTION OF SURFACE FEATURES WE COULD SEE THUNDERSTORM
INITIATION AND SEVERE POTENTIAL BY MIDDAY FURTHER SOUTH (I-70
CORRIDOR) BEFORE ANY PRIMARY THUNDERSTORM CHANCES TRANSITION NORTH
AND WEST. WE WILL NEED TO MONITOR AND ADJUST AS CONFIDENCE INCREASE
BASED ON REAL TIME DATA AND NEW RUNS OF SHORT RANGE GUIDANCE TO GET
A BETTER HANDLE ON SENSIBLE WEATHER OVER OUR CWA THROUGH THIS
EVENING.
AS UPPER LOW TRANSITIONS EAST A COLD FRONT EVENTUALLY WILL PUSH SOUTH
TONIGHT BEFORE STALLING ACROSS THE SOUTHERN PART OF OUR CWA. BESIDES
COMPLICATING THE TEMP FORECAST...THIS FEATURE COULD ACT AS A FOCUS FOR
ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT AS A SECONDARY SHORTWAVE
TROUGH MOVES ACROSS THE NORTHERN PLAINS BEHIND THE INITIAL UPPER
LOW. I USED A CONSENSUS BLEND OF TEMPS THROUGH FRI AND LINGERED POPS
THROUGH FRI NIGHT TO ACCOUNT FOR LIFT/MOISTURE ALONG FRONT AND
ASSOCIATE WITH WEAK TROUGH PASSAGE. WHILE TEMPS SHOULD RETURN TO
NEAR SEASONAL VALUES...IT DOES LOOK LIKE WE HAVE POTENTIAL FOR LOW
TEMPS TO DROP WELL BELOW NORMAL IN THE 30S...AND ACTUALLY WITHIN
FROST ADVISORY CRITERIA.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 215 AM MDT WED MAY 7 2014
WESTERLY ZONAL FLOW ALOFT WILL BE PRESENT ACROSS THE HIGH PLAINS
SATURDAY...WHICH WILL BRING BENIGN CONDITIONS ACROSS THE FORECAST
AREA. A POSITIVELY TILTED UPPER LEVEL TROUGH WILL BEGIN TO MOVE INTO
THE GREAT BASIN REGION AND CONTINUE TO PROGRESS INTO THE TRI STATE
AREA SATURDAY NIGHT. MODEL RUNS DIFFER AS TO THE LOCATION OF THE
ENSUING TROUGH AS WELL AS THE TIMING OF THE PASSAGE OF THE TROUGH
AXIS THROUGH THE REGION...BUT THIS WEATHER MAKING SYSTEM SHOULD
AFFECT THE AREA SOMETIME BETWEEN THE SATURDAY NIGHT TO MONDAY NIGHT
TIME FRAME. MOST MODEL FORECASTS INDICATE A SHORTWAVE RIDGE WILL
MOVE INTO THE HIGH PLAINS ONCE THE TROUGH AXIS MOVES EASTWARD ON
TUESDAY...BUT THE GEM MODEL HAS THE UPPER LEVEL LOW SYSTEM BECOMING
CUT OFF OVER THE HIGH PLAINS REGION. TENDED TO SIDE WITH THE DRY
FORECAST AS THE ECMWF...GFS AND DGEX FORECASTS INDICATE THE RIDGE.
THE MAIN CONCERN FOR THE LONG TERM FORECAST PERIOD WILL BE THE
CHANCES FOR THUNDERSTORMS SATURDAY NIGHT THROUGH MONDAY.
THUNDERSTORMS AND PRECIPITATION CHANCES MAY LINGER INTO TUESDAY IF
THE FLOW ALOFT BECOMES CUT OFF...WHICH WILL AID IN MORE
PRECIPITATION PRODUCTION. LATEST MODEL FORECASTS PLACE THE GREATEST
MID AND LOWER LEVEL JET SPEEDS AND HIGHEST AREAS OF INSTABILITY WELL
TO THE EAST OF THE FORECAST AREA FOR THE PERIOD FOR GREATEST
PRECIPITATION POTENTIAL...SO THUNDERSTORM ACTIVITY IS NOT EXPECTED
TO BECOME SEVERE.
DUE TO THE ZONAL FLOW PATTERN SATURDAY FOLLOWED BY A PUSH OF COOLER
AIR ALOFT WITH THE TROUGH PATTERN...TEMPERATURES THROUGH THE LONG
TERM PERIOD WILL BE NEAR TO SLIGHTLY BELOW NORMAL WITH HIGHS
GENERALLY IN THE MID 60S TO LOWER 70S. LOW TEMPERATURES WILL SPAN
DURING THIS PERIOD BETWEEN THE LOW TO UPPER 40S...WITH SOME SPOTS IN
EASTERN COLORADO DIPPING INTO THE UPPER 30S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 545 AM MDT WED MAY 7 2014
EARLY IN THE TAF PERIODS LOW LEVEL MOISTURE POOLING NORTH OF
STATIONARY FRONT WILL LEAD TO VIS VARYING FROM 4-7SM OVER NW KS
AND SW NE THROUGH ABOUT 15Z. NOT CONFIDENT ENOUGH TO PUT MVFR VIS
IN TAF...SO LIMITED VIS RESTRICTION TO 6SM AS THIS LIGHT FOG IS
FAIRLY PATCHY. AS FRONT LIFTS NORTH TODAY AND SURFACE LOW DEEPENS
GUSTY SOUTH WINDS WILL DEVELOP WITH GUSTS TO 30KT AT KGLD AND
AROUND 20-25KT AT MCK. A LOT OF SPREAD ON GUIDANCE ON TIMING OF
THIS FRONT AND A POTENTIAL COLD FRONT TONIGHT. FOR NOW SHOWED
WIND SHIFT TO W-NW TONIGHT AT BOTH TERMINALS BASED ON LATEST
NAM/RAP. WITH SLOWER WARM FRONT IT LOOKS LIKE A FEW THUNDERSTORMS
COULD DEVELOP AROUND BOTH TERMINALS...HOWEVER AT THIS TIME
CONFIDENCE WAS TOO LOW IN INITIATION OR COVERAGE TO ADD MENTION TO
TAFS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING UNTIL 9 PM MDT /10 PM CDT/ THIS EVENING FOR
KSZ013>016-027>029-041-042.
WIND ADVISORY FROM 3 PM MDT /4 PM CDT/ THIS AFTERNOON TO 9 PM
MDT /10 PM CDT/ THIS EVENING FOR KSZ027>029-041-042.
CO...RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ253-254.
WIND ADVISORY FROM 3 PM THIS AFTERNOON TO 9 PM MDT THIS EVENING
FOR COZ092.
NE...NONE.
&&
$$
UPDATE...BRB
SHORT TERM...DR
LONG TERM...MK
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
545 AM MDT WED MAY 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 225 AM MDT WED MAY 7 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW DEEPENING TROUGH
CURRENTLY CENTERED OVER THE GREAT BASIN WITH SW FLOW EXTENDING
ACROSS CENTRAL ROCKIES AND PLAINS. AT THE SURFACE LOW PRESSURE
CURRENTLY EXTENDS FROM EASTCENTRAL COLORADO ACROSS THE TRI STATE
REGION WITH A STATIONARY FRONT BISECTING THIS FEATURE GENERALLY
ALONG AND SOUTH OF INTERSTATE 70. A DRY LINE EXTENDING ACROSS CENTRAL
KS HAS BEEN BACKING UP TOWARDS THE EASTERN PART OF OUR CWA.
PARTICULARLY LOW CONFIDENCE IN FORECAST FOR TODAY AS A RESULT OF THE
LINGERING STATIONARY FRONT AND INCONSISTENCIES BETWEEN GUIDANCE ON
EVOLUTION OF SURFACE LOW AND FRONT TIMING AS UPPER TROUGH SHIFTS
EAST INTO THE PLAINS. THIS IS A REFLECTION OF MODEL DIFFERENCES ON
EVOLUTION/TRACK OF CLOSED H5/H7 LOW CENTERS ACROSS THE PLAINS
TODAY/TONIGHT. WE COULD SEE WIDE RANGING IMPACTS DEPENDING ON ALL OF
THE ABOVE MENTIONED VARIANCES ON BOTH OUR RFW...A POSSIBLE WIND
ADVISORY...AND POTENTIAL SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE
NORTHERN HALF OF OUR CWA. THERE IS SO MUCH SPREAD BETWEEN MODELS
FROM THE I-70 CORRIDOR NORTH ALL I WAS UNCOMFORTABLE DOING MORE THAN
NUDGING TOWARDS THE LATEST BLENDS/NAM TRENDS. THIS PUTS THE SE HALF
OF OUR CWA NEAR WIND ADVISORY CRITERIA...AND ANOTHER ROW OF COUNTIES
WITHIN RFW CRITERIA. REGARDING THE CURRENT RFW AND POSSIBLE WIND
ADVISORY...CONFIDENCE IS JUST TOO LOW TO MAKE HIGHLIGHT CHANGES.
BASED ON EVOLUTION OF SURFACE FEATURES WE COULD SEE THUNDERSTORM
INITIATION AND SEVERE POTENTIAL BY MIDDAY FURTHER SOUTH (I-70
CORRIDOR) BEFORE ANY PRIMARY THUNDERSTORM CHANCES TRANSITION NORTH
AND WEST. WE WILL NEED TO MONITOR AND ADJUST AS CONFIDENCE INCREASE
BASED ON REAL TIME DATA AND NEW RUNS OF SHORT RANGE GUIDANCE TO GET
A BETTER HANDLE ON SENSIBLE WEATHER OVER OUR CWA THROUGH THIS
EVENING.
AS UPPER LOW TRANSITIONS EAST A COLD FRONT EVENTUALLY WILL PUSH SOUTH
TONIGHT BEFORE STALLING ACROSS THE SOUTHERN PART OF OUR CWA. BESIDES
COMPLICATING THE TEMP FORECAST...THIS FEATURE COULD ACT AS A FOCUS FOR
ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT AS A SECONDARY SHORTWAVE
TROUGH MOVES ACROSS THE NORTHERN PLAINS BEHIND THE INITIAL UPPER
LOW. I USED A CONSENSUS BLEND OF TEMPS THROUGH FRI AND LINGERED POPS
THROUGH FRI NIGHT TO ACCOUNT FOR LIFT/MOISTURE ALONG FRONT AND
ASSOCIATE WITH WEAK TROUGH PASSAGE. WHILE TEMPS SHOULD RETURN TO
NEAR SEASONAL VALUES...IT DOES LOOK LIKE WE HAVE POTENTIAL FOR LOW
TEMPS TO DROP WELL BELOW NORMAL IN THE 30S...AND ACTUALLY WITHIN
FROST ADVISORY CRITERIA.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 215 AM MDT WED MAY 7 2014
WESTERLY ZONAL FLOW ALOFT WILL BE PRESENT ACROSS THE HIGH PLAINS
SATURDAY...WHICH WILL BRING BENIGN CONDITIONS ACROSS THE FORECAST
AREA. A POSITIVELY TILTED UPPER LEVEL TROUGH WILL BEGIN TO MOVE INTO
THE GREAT BASIN REGION AND CONTINUE TO PROGRESS INTO THE TRI STATE
AREA SATURDAY NIGHT. MODEL RUNS DIFFER AS TO THE LOCATION OF THE
ENSUING TROUGH AS WELL AS THE TIMING OF THE PASSAGE OF THE TROUGH
AXIS THROUGH THE REGION...BUT THIS WEATHER MAKING SYSTEM SHOULD
AFFECT THE AREA SOMETIME BETWEEN THE SATURDAY NIGHT TO MONDAY NIGHT
TIME FRAME. MOST MODEL FORECASTS INDICATE A SHORTWAVE RIDGE WILL
MOVE INTO THE HIGH PLAINS ONCE THE TROUGH AXIS MOVES EASTWARD ON
TUESDAY...BUT THE GEM MODEL HAS THE UPPER LEVEL LOW SYSTEM BECOMING
CUT OFF OVER THE HIGH PLAINS REGION. TENDED TO SIDE WITH THE DRY
FORECAST AS THE ECMWF...GFS AND DGEX FORECASTS INDICATE THE RIDGE.
THE MAIN CONCERN FOR THE LONG TERM FORECAST PERIOD WILL BE THE
CHANCES FOR THUNDERSTORMS SATURDAY NIGHT THROUGH MONDAY.
THUNDERSTORMS AND PRECIPITATION CHANCES MAY LINGER INTO TUESDAY IF
THE FLOW ALOFT BECOMES CUT OFF...WHICH WILL AID IN MORE
PRECIPITATION PRODUCTION. LATEST MODEL FORECASTS PLACE THE GREATEST
MID AND LOWER LEVEL JET SPEEDS AND HIGHEST AREAS OF INSTABILITY WELL
TO THE EAST OF THE FORECAST AREA FOR THE PERIOD FOR GREATEST
PRECIPITATION POTENTIAL...SO THUNDERSTORM ACTIVITY IS NOT EXPECTED
TO BECOME SEVERE.
DUE TO THE ZONAL FLOW PATTERN SATURDAY FOLLOWED BY A PUSH OF COOLER
AIR ALOFT WITH THE TROUGH PATTERN...TEMPERATURES THROUGH THE LONG
TERM PERIOD WILL BE NEAR TO SLIGHTLY BELOW NORMAL WITH HIGHS
GENERALLY IN THE MID 60S TO LOWER 70S. LOW TEMPERATURES WILL SPAN
DURING THIS PERIOD BETWEEN THE LOW TO UPPER 40S...WITH SOME SPOTS IN
EASTERN COLORADO DIPPING INTO THE UPPER 30S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 545 AM MDT WED MAY 7 2014
EARLY IN THE TAF PERIODS LOW LEVEL MOISTURE POOLING NORTH OF
STATIONARY FRONT WILL LEAD TO VIS VARYING FROM 4-7SM OVER NW KS
AND SW NE THROUGH ABOUT 15Z. NOT CONFIDENT ENOUGH TO PUT MVFR VIS
IN TAF...SO LIMITED VIS RESTRICTION TO 6SM AS THIS LIGHT FOG IS
FAIRLY PATCHY. AS FRONT LIFTS NORTH TODAY AND SURFACE LOW DEEPENS
GUSTY SOUTH WINDS WILL DEVELOP WITH GUSTS TO 30KT AT KGLD AND
AROUND 20-25KT AT MCK. A LOT OF SPREAD ON GUIDANCE ON TIMING OF
THIS FRONT AND A POTENTIAL COLD FRONT TONIGHT. FOR NOW SHOWED
WIND SHIFT TO W-NW TONIGHT AT BOTH TERMINALS BASED ON LATEST
NAM/RAP. WITH SLOWER WARM FRONT IT LOOKS LIKE A FEW THUNDERSTORMS
COULD DEVELOP AROUND BOTH TERMINALS...HOWEVER AT THIS TIME
CONFIDENCE WAS TOO LOW IN INITIATION OR COVERAGE TO ADD MENTION TO
TAFS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING FROM 11 AM MDT /NOON CDT/ THIS MORNING TO 9 PM
MDT /10 PM CDT/ THIS EVENING FOR KSZ013>016-027>029-041-042.
CO...RED FLAG WARNING FROM 11 AM THIS MORNING TO 9 PM MDT THIS
EVENING FOR COZ253-254.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...MK
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
226 AM MDT WED MAY 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 225 AM MDT WED MAY 7 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW DEEPENING TROUGH
CURRENTLY CENTERED OVER THE GREAT BASIN WITH SW FLOW EXTENDING
ACROSS CENTRAL ROCKIES AND PLAINS. AT THE SURFACE LOW PRESSURE
CURRENTLY EXTENDS FROM EASTCENTRAL COLORADO ACROSS THE TRI STATE
REGION WITH A STATIONARY FRONT BISECTING THIS FEATURE GENERALLY
ALONG AND SOUTH OF INTERSTATE 70. A DRY LINE EXTENDING ACROSS CENTRAL
KS HAS BEEN BACKING UP TOWARDS THE EASTERN PART OF OUR CWA.
PARTICULARLY LOW CONFIDENCE IN FORECAST FOR TODAY AS A RESULT OF THE
LINGERING STATIONARY FRONT AND INCONSISTENCIES BETWEEN GUIDANCE ON
EVOLUTION OF SURFACE LOW AND FRONT TIMING AS UPPER TROUGH SHIFTS
EAST INTO THE PLAINS. THIS IS A REFLECTION OF MODEL DIFFERENCES ON
EVOLUTION/TRACK OF CLOSED H5/H7 LOW CENTERS ACROSS THE PLAINS
TODAY/TONIGHT. WE COULD SEE WIDE RANGING IMPACTS DEPENDING ON ALL OF
THE ABOVE MENTIONED VARIANCES ON BOTH OUR RFW...A POSSIBLE WIND
ADVISORY...AND POTENTIAL SEVERE THUNDERSTORM DEVELOPMENT ACROSS THE
NORTHERN HALF OF OUR CWA. THERE IS SO MUCH SPREAD BETWEEN MODELS
FROM THE I-70 CORRIDOR NORTH ALL I WAS UNCOMFORTABLE DOING MORE THAN
NUDGING TOWARDS THE LATEST BLENDS/NAM TRENDS. THIS PUTS THE SE HALF
OF OUR CWA NEAR WIND ADVISORY CRITERIA...AND ANOTHER ROW OF COUNTIES
WITHIN RFW CRITERIA. REGARDING THE CURRENT RFW AND POSSIBLE WIND
ADVISORY...CONFIDENCE IS JUST TOO LOW TO MAKE HIGHLIGHT CHANGES.
BASED ON EVOLUTION OF SURFACE FEATURES WE COULD SEE THUNDERSTORM
INITIATION AND SEVERE POTENTIAL BY MIDDAY FURTHER SOUTH (I-70
CORRIDOR) BEFORE ANY PRIMARY THUNDERSTORM CHANCES TRANSITION NORTH
AND WEST. WE WILL NEED TO MONITOR AND ADJUST AS CONFIDENCE INCREASE
BASED ON REAL TIME DATA AND NEW RUNS OF SHORT RANGE GUIDANCE TO GET
A BETTER HANDLE ON SENSIBLE WEATHER OVER OUR CWA THROUGH THIS
EVENING.
AS UPPER LOW TRANSITIONS EAST A COLD FRONT EVENTUALLY WILL PUSH SOUTH
TONIGHT BEFORE STALLING ACROSS THE SOUTHERN PART OF OUR CWA. BESIDES
COMPLICATING THE TEMP FORECAST...THIS FEATURE COULD ACT AS A FOCUS FOR
ADDITIONAL SHOWER/THUNDERSTORM DEVELOPMENT AS A SECONDARY SHORTWAVE
TROUGH MOVES ACROSS THE NORTHERN PLAINS BEHIND THE INITIAL UPPER
LOW. I USED A CONSENSUS BLEND OF TEMPS THROUGH FRI AND LINGERED POPS
THROUGH FRI NIGHT TO ACCOUNT FOR LIFT/MOISTURE ALONG FRONT AND
ASSOCIATE WITH WEAK TROUGH PASSAGE. WHILE TEMPS SHOULD RETURN TO
NEAR SEASONAL VALUES...IT DOES LOOK LIKE WE HAVE POTENTIAL FOR LOW
TEMPS TO DROP WELL BELOW NORMAL IN THE 30S...AND ACTUALLY WITHIN
FROST ADVISORY CRITERIA.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 215 AM MDT WED MAY 7 2014
WESTERLY ZONAL FLOW ALOFT WILL BE PRESENT ACROSS THE HIGH PLAINS
SATURDAY...WHICH WILL BRING BENIGN CONDITIONS ACROSS THE FORECAST
AREA. A POSITIVELY TILTED UPPER LEVEL TROUGH WILL BEGIN TO MOVE INTO
THE GREAT BASIN REGION AND CONTINUE TO PROGRESS INTO THE TRI STATE
AREA SATURDAY NIGHT. MODEL RUNS DIFFER AS TO THE LOCATION OF THE
ENSUING TROUGH AS WELL AS THE TIMING OF THE PASSAGE OF THE TROUGH
AXIS THROUGH THE REGION...BUT THIS WEATHER MAKING SYSTEM SHOULD
AFFECT THE AREA SOMETIME BETWEEN THE SATURDAY NIGHT TO MONDAY NIGHT
TIME FRAME. MOST MODEL FORECASTS INDICATE A SHORTWAVE RIDGE WILL
MOVE INTO THE HIGH PLAINS ONCE THE TROUGH AXIS MOVES EASTWARD ON
TUESDAY...BUT THE GEM MODEL HAS THE UPPER LEVEL LOW SYSTEM BECOMING
CUT OFF OVER THE HIGH PLAINS REGION. TENDED TO SIDE WITH THE DRY
FORECAST AS THE ECMWF...GFS AND DGEX FORECASTS INDICATE THE RIDGE.
THE MAIN CONCERN FOR THE LONG TERM FORECAST PERIOD WILL BE THE
CHANCES FOR THUNDERSTORMS SATURDAY NIGHT THROUGH MONDAY.
THUNDERSTORMS AND PRECIPITATION CHANCES MAY LINGER INTO TUESDAY IF
THE FLOW ALOFT BECOMES CUT OFF...WHICH WILL AID IN MORE
PRECIPITATION PRODUCTION. LATEST MODEL FORECASTS PLACE THE GREATEST
MID AND LOWER LEVEL JET SPEEDS AND HIGHEST AREAS OF INSTABILITY WELL
TO THE EAST OF THE FORECAST AREA FOR THE PERIOD FOR GREATEST
PRECIPITATION POTENTIAL...SO THUNDERSTORM ACTIVITY IS NOT EXPECTED
TO BECOME SEVERE.
DUE TO THE ZONAL FLOW PATTERN SATURDAY FOLLOWED BY A PUSH OF COOLER
AIR ALOFT WITH THE TROUGH PATTERN...TEMPERATURES THROUGH THE LONG
TERM PERIOD WILL BE NEAR TO SLIGHTLY BELOW NORMAL WITH HIGHS
GENERALLY IN THE MID 60S TO LOWER 70S. LOW TEMPERATURES WILL SPAN
DURING THIS PERIOD BETWEEN THE LOW TO UPPER 40S...WITH SOME SPOTS IN
EASTERN COLORADO DIPPING INTO THE UPPER 30S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1140 PM MDT TUE MAY 6 2014
VFR CONDITIONS WILL PREVAIL AT MCK AND GLD THROUGH THE TAF PERIOD.
A WARM FRONT PUSHES NORTH ACROSS THE REGION DURING THE DAY ON
WEDNESDAY AS A SURFACE LOW PRESSURE CENTER DEEPENS OVER EASTERN
COLORADO. AS THE FRONT PASSES OVER THE TAF SITES BETWEEN
19-21Z...WINDS ARE EXPECTED TO TURN SOUTH AND BECOME GUSTY DURING
THE AFTERNOON AND EVENING. THERE IS A POSSIBILITY OF PATCHY FOG
DEVELOPING NEAR MCK BETWEEN 10Z-14Z WEDNESDAY MORNING AS
TEMPERATURES COOL AND APPROACH THE DEWPOINT VALUES IN THE LOWER
50S WHICH WILL BRING THE BOUNDARY LAYER NEAR SATURATION. HAVE
INCLUDED A PREVAILING CONDITION OF 6SM WITH A LOW CLOUD LAYER AT
MCK AS A RESULT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...RED FLAG WARNING FROM 11 AM MDT /NOON CDT/ THIS MORNING TO 9 PM
MDT /10 PM CDT/ THIS EVENING FOR KSZ013>016-027>029-041-042.
CO...RED FLAG WARNING FROM 11 AM THIS MORNING TO 9 PM MDT THIS
EVENING FOR COZ253-254.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...MK
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS PADUCAH KY
845 PM CDT Thu May 8 2014
.UPDATE...
Issued at 845 PM CDT THU MAY 8 2014
A north to south oriented line of thunderstorms with trailing
stratiform rain is approaching the Mississippi River and will
continue to move north northeast into southern Illinois mainly to
the west of I-57 through the remainder of the evening. It looks
like western portions of southeast Missouri will be drying out
pretty soon, and they may have a few hours before the next round
arrives midnight or a bit later.
LAPS soundings indicate a weakening cap and the RAP has LI`s of
-2 to -3 over southern Illinois. See no reason why they will not
continue through much of southern Illinois with modest intensity
this evening. Not sure just how far east they will get, but the
RAP tries hard to confine the precipitation to Missouri and
Illinois through midnight. Of course, as the upper trough pushes
closer to the area overnight, another round of widespread showers
and thunderstorms is expected to overspread most of the area by
daybreak Friday morning.
Tried to account for the aforementioned trends in the hourly
pop/wx grids, but made few other changes with this update.
The Lake Wind Advisory died a natural death at 01Z.
UPDATE Issued at 610 PM CDT THU MAY 8 2014
UPDATE FOR AVIATION ONLY.
&&
.SHORT TERM...(Tonight through Saturday night)
Issued at 304 PM CDT THU MAY 8 2014
Focus in the short term continues to be on convective chances.
Band of convection central/sw MO into west AR will track slowly
east late this afternoon and evening. Will have best chance PoPs
west 1/2 before midnight shifting slowly east overnight. Really
not all that concerned about severe wx over our SEMO counties
at this time given marginal lapse rates modest instability.
Convective chances will shift east Friday morning. It may linger
from SW IN into the Pennyrile through early afternoon, where temps
may be held down a couple of degrees. Otherwise, the atmosphere
should have some time to recover heading west, ahead of an
approaching, stalling front. Convection should take shape in this
area and eventually focus SRN IL into SE MO late in the day in
some form or fashion then head east through the evening. Mid and
upper level winds are relatively impressive, not so much blyr-
700mb. Storms with decent mid level rotation, with steepening low
level lapse rates may yield wind and hailers, best chances
west/southwest part of the CWFA. Chances should diminish from west
to east after midnight Friday night. May see a lull Saturday, then
another chance moving in from the west overnight Saturday night,
potentially an MCS. Slightly better chances north than south.
.LONG TERM...(Sunday through Thursday)
Issued at 304 PM CDT THU MAY 8 2014
The main weather story during the long term will be a strong cold
front that will sweep across our region early next week. This front
will be accompanied by a period of rain and thunderstorms. The front
will bring a noticeable cooling of temperatures from above normal to
below normal.
As far as the daily details...
On Sunday...a reservoir of warm...moist and very unstable air will
cover a large part of the central states including our region. It is
likely that one or more convective systems will develop over the
Plains and then propagate eastward through this unstable air
mass...fed by a moderately strong low level jet. Since there is
little skill at forecasting these systems in the long range
period...the forecast will include a generic chance pop. High temps
will remain quite warm...basically in line with gfs/ecmwf mos.
On Monday...the high amplitude 500 mb trough and associated cold
front will draw closer. The genesis region of convective systems
will remain to our west. Will continue with a warm and humid
forecast along with chance pops.
There remains unusually wide divergence among the models concerning
the timing of the frontal system Monday night through Tuesday night.
Both the gfs and ecmwf have trended slower compared to this time
Wednesday. The 12z gfs takes the front across our region on Monday
night...while the ecmwf has it coming through Tuesday night. The
highest pops will be on Tuesday...mainly in the likely category
across our region. Will introduce chance pops for Wednesday based on
the slower timing of the system. However...the bulk of the precip
should be over by then.
The model 850 temps have trended cooler for Wednesday into Thursday
by several degrees. Based on model 850 mb temps from plus 1 to plus
4...highs will only be in the 60s even with plenty of sun. Forecast
temps will be trended lower for Wed into Thurs.
&&
.AVIATION...
Issued at 610 PM CDT THU MAY 8 2014
Showers were developing over SEMO and heading straight for KCGI.
Amended old taf and included mention in new set. These echoes were
intensifying and could lay down a strike or two. This convection
is expected to dissipate with the loss of daytime heating with the
main area moving into the taf sites between 5z and 8z. Also
introduced WS overnight as fcst sounding indicate a 40kt SSW flow
around 2k feet. Expect mostly MVFR cigs and vsby through most of
the valid time of the tafs after the precip moves in.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
AVIATION...KH
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
955 PM CDT THU MAY 8 2014
.DISCUSSION...
REGIONAL 88DS SHOW A LINE OF THUNDERSTORMS STRETCHING FROM THE
ARKLATEX THROUGH NERN TX TO NOT QUITE THE HILL COUNTRY. SRN END OF
THE LINE HAS BEEN SLOW TO DEVELOP THIS EVENING AS BEST DYNAMICS
PUSH NEWD WITH THE ATTENDANT DISTURBANCE ALOFT. THIS SCENARIO GOES
WELL WITH BOTH THE LATEST GFS AND HRRR RUNS WHICH KEEP THE BULK
OF THE PRECIP ACROSS NRN LA. THUS HAVE LOWERED POPS BACK TO JUST
THE CHANCE CATEGORY FOR THE REST OF THE NIGHT TO ACCOUNT. BIG
QUESTION APPEARS TO BE RAIN CHANCES OVER THE SERN ZONES AS RADARS
ARE BEGINNING TO LIGHT UP OVER THE NWRN GULF AS ACTIVITY INCREASES
WITH NEXT DISTURBANCE ROUNDING THE BASE OF THE TROF...AND THUS
HAVE NUDGED UP POPS SLIGHTLY OVER THIS AREA TO ACCOUNT.
ELSEWHERE JUST MINOR TWEAKS MADE TO INHERITED GRIDS/ZONES. UPDATE
OUT SHORTLY.
25
&&
.PREV DISCUSSION... /ISSUED 618 PM CDT THU MAY 8 2014/
AVIATION...
AREAS OF RAIN AND SHOWERS MIXED WILL CONT THRU THE EVENING HOURS.
STORMS ARE MOVING OUT OF THE DFW AREA AND INTO CNTRL TX ATTM.
CEILINGS VARYING FROM VFR TO IFR DEPENDING ON STORM LOCATION TO
THE TAF SITES. THIS TYPE OF PATTERN WILL CONTINUE INTO THE
OVERNIGHT HOURS.
PREV DISCUSSION... /ISSUED 354 PM CDT THU MAY 8 2014/
DISCUSSION...CONDITIONS ARE MOISTENING ACROSS THE REGION THIS
AFTERNOON WITH LIGHT RAIN COVERING MOST OF SE TX AND PUSHING INTO
FAR WEST LA AS AN UPPER DISTURBANCE APPROACHES FROM THE WEST.
LIGHT RAIN WITH A FEW EMBEDDED HEAVIER SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE THROUGH THE EVENING. LIFT AND MOISTURE WILL
CONTINUE TO INCREASE TONIGHT WITH SHOWERS AND STORMS REMAINING
LIKELY FOR THE NORTHERN ZONES AND SCT FOR THE SOUTHERN PORTIONS.
WITH THE AREA RECEIVING HIGH MOISTURE CONTENT AND MODEST UPPER
SUPPORT BUT LACKING ANY SURFACE BOUNDARY OR FOCUS, RAIN AND STORMS
WILL REMAIN SCT TO NUMEROUS, AND GENERALLY LESS THAN WIDESPREAD
TONIGHT INTO FRIDAY. THE BEST SUPPORT FOR RAIN WILL MOVE EAST OF
THE AREA FRIDAY INTO SATURDAY WITH SUNDAY KEEPING ONLY A SLIGHT
CHANCE AROUND.
RAIN CHANCES WILL INCREASE AGAIN MONDAY INTO TUESDAY AS A COLD
FRONT MOVES INTO AND THEN THROUGH THE REGION. DRIER AND SLIGHTLY
COOLER WEATHER WILL RETURN TO THE REGION BY THE MIDDLE OF THE
COMING WEEK.
MARINE...THE WINDS WILL DECREASE THROUGH THE EVENING AS THE
PRESSURE GRADIENT RELAXES ACROSS THE AREA. WINDS WILL REMAIN
GENERALLY SOUTH TO SOUTHEAST INTO EARLY NEXT WEEK. A COLD FRONT
MAY MOVE OFF THE COAST DURING TUESDAY VEERING THE WINDS OFFSHORE.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 72 83 70 85 71 / 30 50 30 20 10
KBPT 72 84 70 84 71 / 30 30 30 20 10
KAEX 71 85 67 87 68 / 30 60 30 20 10
KLFT 72 83 71 84 71 / 30 70 40 40 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT EXERCISE CAUTION UNTIL 1 AM CDT FRIDAY FOR THE
FOLLOWING ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH
ISLAND TX OUT 20 NM...COASTAL WATERS FROM INTRACOASTAL CITY
TO CAMERON LA OUT 20 NM...COASTAL WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM...
WATERS FROM INTRACOASTAL CITY TO CAMERON LA FROM 20 TO 60
NM...WATERS FROM CAMERON LA TO HIGH ISLAND TX FROM 20 TO 60
NM...WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL
CITY LA FROM 20 TO 60 NM.
&&
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.LAKECHARLES.GOV
WWW.TWITTER.COM/NWSLAKECHARLES
WWW.YOUTUBE.COM/NWSLAKECHARLES
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
946 PM CDT THU MAY 8 2014
.DISCUSSION...
MOSAIC RADAR ANALYSIS SHOWING A RATHER LARGE LINE OF CONVECTION
EXTENDING FROM SOUTH CENTRAL ARKANSAS THROUGH EXTREME NORTHWEST
LOUISIANA AND NORTHEAST TEXAS. THIS ACTIVITY DEVELOPING WELL AHEAD
OF THE SHORTWAVE TROUGH WHICH IS CURRENT ACROSS THE TX/OK PNHDL
INTO THE SOUTHERN AND CENTRAL PLAINS. HRRR HAS A GOOD HANDLE ON
THIS CONVECTION CONTINUING TO PUSH SOUTH AND EAST THROUGH THE
NIGHT WITH RAINFALL RATES NEAR 1.5 INCHES PER HOUR ALONG THE
LEADING EDGE OF THE CONVECTION. HAVE UPDATED THE FORECAST TO GO
WITH CATEGORICAL POPS ACROSS THE NORTHWEST HALF FOR THE REMAINDER
OF THE EVENING AND THEN ACROSS THE EASTERN HALF AFTER MIDNIGHT.
ALSO ADDED THE LOCALLY HEAVY RAINFALL MODIFIER GIVEN THE RAINFALL
RATES AND WHAT HAS ALREADY OCCURRED.
CONCERNING TEMPERATURES...OUR NORTHWEST ZONES ARE ALREADY A DEGREE
OR TWO BELOW FORECAST MINS SO LOWERED MINS BUT THESE TEMPERATURES
MAY RECOVER SLIGHTLY AFTER THE CONVECTION ENDS.
ALSO ADJUSTED SKY/WIND AND DEWPOINT GRIDS BASED ON CURRENT TRENDS.
UPDATE ALREADY SENT...13.
&&
.PREV DISCUSSION... /ISSUED 753 PM CDT THU MAY 8 2014/
AVIATION...
A LINE OF STRONG CONVECTION WILL MOVE EAST ACROSS THE FORECAST AREA
THIS EVENING AND EARLY FRIDAY MORNING. EXPECT MODERATE TO SEVERE
TURBULENCE WITH THIS ACTIVITY AS WELL AS PERIODS OF IFR CIGS AND
VSBYS DUE TO HEAVY RAINFALL. FOLLOWING THE LINE...CIGS WILL REMAIN
MOSTLY MVFR AND OCCASIONAL LIGHTER RAINFALL AND FOG WILL REDUCE
VSBYS BETWEEN 2 AND 5 MILES. CONDITIONS WILL IMPROVE AFTER 16Z
FRIDAY TO VFR MOST LOCATIONS. SURFACE WIND TO REMAIN SOUTH AROUND
10 KTS TONIGHT EXCEPT WIND GUSTS TO 40 KTS ARE POSSIBLE IN AND
AROUND THE CONVECTION. WIND ON FRIDAY SOUTH TO SOUTHWEST 10 TO 15
KTS. /14/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 68 84 67 87 68 / 80 40 20 20 20
MLU 71 82 66 86 67 / 80 50 30 20 20
DEQ 64 84 61 85 66 / 80 50 20 20 20
TXK 66 83 66 86 67 / 80 50 40 20 20
ELD 66 83 65 86 66 / 80 50 40 20 20
TYR 66 88 66 88 70 / 80 20 20 20 10
GGG 68 87 66 87 70 / 80 30 20 20 10
LFK 71 89 68 88 70 / 80 30 20 20 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
13
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
401 PM EDT WED MAY 7 2014
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL LIFT NORTH AS A WARM FRONT TONIGHT
INTO THURSDAY MORNING. HIGH PRESSURE WILL BECOME ANCHORED OFF THE
SOUTHEAST COAST THURSDAY AFTERNOON THROUGH FRIDAY...AS THE FRONTAL
BOUNDARY LINGERS ALONG THE MID ATLANTIC COAST.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
MID-AFTERNOON WX ANALYSIS FEATURES ~1024MB SFC HIGH PRESSURE OVER
ON/QC, RIDGING SOUTHEAST INTO THE NORTHEAST/MID-ATLANTIC REGION,
WITH A QUASI-STATIONARY FRONTAL BOUNDARY STILL IN PLACE FROM SE NC
BACK INTO THE CENTRAL APPALACHIANS. ALOFT, UPPER AIR ANALYSIS
SHOWS A DEEP TROUGH IN PLACE OVER THE INTERMOUNTAIN WEST, AND A
SECOND DEPARTING TROUGH OVER ATLANTIC CANADA. MID/UPPER LEVEL
RIDGE AXIS CONTINUES TO TRANSLATE EASTWARD TODAY, ORIENTED FROM
THE SOUTHEAST INTO THE OHIO VALLEY.
QUICK MOVING SHORTWAVE TROUGH PINWHEELED FROM WESTERN PA/MD ACROSS
TO THE LOWER EASTERN SHORE BY MID AFTERNOON. MUCH OF THIS ACTIVITY
HAS PUSHED OFFSHORE, BUT HAVE RETAINED SOME ISO TO SCT SHRA
WORDING FOR THE BALANCE OF THE AFTN/EARLY EVENING AS THIS AREA
REMAINS ON THE SOUTHERN PERIPHERY OF DEEPER LAYER MOISTURE AS
UPPER RIDGE EDGES NORTHEAST THROUGH TONIGHT.
OTHERWISE, EXPECT A DRY AFTN/EVENING. SW FLOW OVER THE SOUTHERN
PLAINS AND SOUTHEAST WILL SHUNT THE STATIONARY FRONT BACK TO THE
NORTH TNGT AND OVERNIGHT AS A WARM FRONT. A SECOND, MORE DEFINED
SHORTWAVE TROUGH TRACKS THROUGH THE NW FLOW TONIGHT INTO EARLY
THURSDAY. HOWEVER, AS THE UPPER RIDGE AND SFC WARM FRONT SLIP
NORTH, THE BEST POTENTIAL FOR SHOWERS/TSTMS WILL SHIFT INTO
PA/NJ/NRN DE/FAR NE MD. DID RETAIN A LOW POP GIVEN THAT THE EASTERN
SHORE AND NRN NECK WILL REMAIN CLOSE ENOUGH TO THE MID-LEVEL
FORCING TO INCLUDED A 20-30% POP BUT EXPECT MOST OF THE NIGHT TO
BE DRY EVEN OVER THESE AREAS. LEANED TOWARDS HIGHER ENVELOPE OF
MOS GUIDANCE GIVEN PERSISTENT MID LVL CLOUDINESS...AS WELL WHAT
WILL LIKELY BE AREAS OF STRATUS ACROSS THE COASTAL PLAIN OVERNIGHT
AS THE FRONT SLIPS NORTH. LOOK FOR EARLY MORNING LOWS IN THE LOWER
TO MIDDLE 60S FOR MOST...U50S TO NEAR 60 EASTERN SHORE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
CLOUDS WL GRADUALLY DECREASE FROM SW-NE THURSDAY...BUT
EXPECT CLOUDS TO LINGER FOR MUCH OF THE DAY OVER THE EASTERN
SHORE AS FRONT REMAINS SLOW TO LIFT ACROSS NORTHEAST COASTAL PLAIN
GIVEN PERSISTENT LLVL EASTERLY FLOW OFF OF THE STILL QUITE CHILLY
ATLANTIC COASTAL WATERS. MEANWHILE BEHIND THE FRONT, EXPECT
THURSDAY TO BE THE WARMEST DAY OF THE YEAR SO FAR W OF THE
BAY. EXPECT HIGHS RANGING FROM THE MID 80S TO AROUND 90. HIGHS
OVER THE EASTERN SHORE SHOULD RANGE FROM THE LOW/MID 70S ALONG THE
IMMEDIATE ATLANTIC COAST...TO THE UPPER 70S/AROUND 80 INLAND.
THE FRONT MAY ACTUALLY DROP BACK S INTO THE EASTERN SHORE AS A
BACKDOOR COLD FRONT THURSDAY NIGHT INTO EARLY FRIDAY...BEFORE
RETREATING NNE FRIDAY AFTERNOON. NAM/GFS BUFR AT SBY SOUNDINGS
SUGGEST SOME STRATUS COULD COME INLAND FROM THE OCEAN. THIS AND
THE ULTIMATE PLACEMENT OF THE FRONT WILL HAVE A LARGE INFLUENCE ON
HIGHS FRIDAY.
WITH UPPER RIDGING IN PLACE FROM THE MID-ATLANTIC WELL NORTH INTO
EASTERN CANADA, AND SURFACE HIGH ALONG/JUST OFFSHORE...EXPECT
ANOTHER VERY WARM TO HOT DAY INLAND ON SW WINDS. ALSO LOOK FOR A BIT
MORE IN THE WAY OF INSTABILITY, AS HIGH RES MODELS ARE BEGINNING
TO HOOK ON TO SOME SUBTLE LEE TROUGHING FRIDAY AFTN/EVENING. GIVEN
THAT DOWNSLOPE FLOW MAY WELL MAKE IT TOO DRY FOR WIDESPREAD OR
EVEN ORGANIZED CONVECTIVE DEVELOPMENT, WILL CAP POP AT SILENT FOR
RIGHT NOW. HOWEVER, WILL NEED TO KEEP AN EYE OUT FOR SOME
ISOLATED, DISORGANIZED CONVECTION FIRING ACROSS THE WEST ON FRIDAY
AFTN/EVENING. HIGHS WARM RIGHT BACK INTO THE 80S TO NEAR 90 WEST
OF THE BAY...WITH U70S TO LOWER 80S OVER THE EASTERN SHORE.
GOOD AGREEMENT AMONGST MODELS IN WASHING OUT NEXT COLD FRONT TO
THE WEST IN WARM/DRY QUASI-ZONAL FLOW. WILL SEE A BIT MORE IN THE
WAY OF SOME DIURNALLY DRIVEN, WIDELY SCT THUNDERSTORMS. HOWEVER,
ONCE AGAIN DYNAMICS AND INSTABILITY OVER OUR REGION APPEAR AS IF
THEY WILL BE RATHER MEAGER. HIGHS GENERALLY BACK INTO THE 80S
INLAND...70S TO NEAR 80 OVER THE EASTERN SHORE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
EARLY SUMMER PATTERN SETTING UP AS BERMUDA RIDGE HOLDS FIRM ACROSS
THE AREA THRU MID WEEK. WASHED OUT FRONTAL BOUNDARY WILL COMBINE WITH
ANY RESIDUAL CONVECTIVE BOUNDARIES SUN THRU TUES. UPSHOT WILL BE LOW
CHCS (20-30%) FOR AFTN/EVENING SHRAS/TSTMS EACH DAY. HIGHS SUN
U70S-L80S XCPT L-M70S AT THE BEACHES. HIGH MON/TUES 80-85...XCPT
75-80 CSTL AREAS. LOWS GNRLY 60-65.
MODELS DEPICT NEXT FRONTAL BOUNDARY CROSSING THE AREA WED. THIS PRBLY THE
BEST CHC FOR ANY WDSPRD PCPN AS IT APPEARS THAT SOME TROPICAL MSTR
GETS TRANSPORTED NORTH ALONG IT. KEPT POPS IN CHC CATEGORY FOR NOW
GIVEN 7 DAYS OUT. HIGHS WED 75-80.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
THE FRONTAL BOUNDARY TO THE SOUTH WILL SLOWLY MOVE BACK NORTH
STARTING TONIGHT. THE 85H FRONTAL IS MOVING NORTH OF THE AREA THIS
AFTERNOON. THIS HAD SOME SHOWERS AND THUNDERSTORMS WHICH MOVED INTO
THE DELMARVA THIS AFTERNOON. THE 85H FRONT WILL BE WELL NORTH OF THE
AREA LATER TONIGHT SO ANY SHOWERS THAT FORM ALONG IT WILL BE TO THE
NORTH OF THE AREA. THE FRONT TO THE SOUTH HAS SOME LOW LEVEL
MOISTURE WITH IT. THIS COULD BRING CIGS DOWN TO MVFR OVERNIGHT
TONIGHT AS THE BOUNDARY SLOWLY WORKS NORTH. LOOKING AT RUC AND NAM
ON BUFKIT CAN SEE CLOUDS LOWERING AFTER MIDNIGHT ACROSS ALL TAF
SITES. NOT COMPLETELY CONVINCED THE ALL THIS LOW LEVEL MOISTURE WILL
RETURN. SO WILL ONLY BRING MVFR CONDITIONS IN AFTER MIDNIGHT THROUGH
SUNRISE. POTENTIAL FOR THESE CLOUDS TO BE LOWER LATE TONIGHT AND AT
SUNRISE. AFTER SUNRISE CLOUDS RISE QUICKLY AND DISSIPATE AT ALL
SITES AS THE WARM FRONT MOVES NORTH OF THE AREA. THIS WILL ALLOW FOR
VFR CONDITIONS ON THURSDAY. EXPECT MAINLY VFR CONDITIONS THROUGH THE
WEEKEND BUT SCATTERED THUNDERSTORMS WILL DEVELOP BOTH SATURDAY AND
SUNDAY AFTERNOON WHICH COULD BE IFR CONDITIONS FOR A SHORT TIME TO
THE TAF SITES.
&&
.MARINE...
SFC PRESSURE GRADIENT BTWN THE S/W TO THE NORTH AND FRNTL BNDRY TO
THE SOUTH RESULTING IN WINDS AROUND 15 KT WITH A FEW GUSTS TO 20 KTS
OVER THE SRN MOST PART OF THE CHES BAY ATTM. THESE CNDTNS XPCTD TO
CONT THRU LATE AFTRN BEFORE DMNSHG TONIGHT. NO SCA ANTICIPATED ATTM.
WARM FRONT PROGGED TO LIFT NORTH OVER THE WATERS TONIGHT AND THU.
FLOW BECOMES S-SW AND PREVAILS THRU THE WEEKEND AS HIGH PRESSURE
ANCHORS OVER THE WRN ATLANTIC. WINDS AOB 15 KTS...SEAS 2-4 FT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...AJZ/MAM
LONG TERM...MPR
AVIATION...JAB
MARINE...SAM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
258 PM EDT WED MAY 7 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS NORTH CAROLINA TODAY.
THE FRONT LIFTS NORTH AS A WARM FRONT TONIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BECOME ANCHORED OFF THE SOUTHEAST COAST
THURSDAY AFTERNOON THROUGH FRIDAY...AS THE FRONTAL BOUNDARY LINGERS
ALONG THE MID ATLANTIC COAST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MID-MORNING WX ANALYSIS FEATURES ~1024MB SFC HIGH PRESSURE OVER
JAMES BAY NOSING SOUTH INTO THE NORTHEAST/MID-ATLANTIC REGION, WITH
A QUASI-STATIONARY FRONTAL BOUNDARY DRAPED WELL SOUTH INTO THE
CAROLINAS. ALOFT, WV/IR IMAGERY SHOWING UPPER LEVEL RIDGE
AXIS EXTENDING FROM THE SOUTHEAST INTO THE TN RVR VALLEY THIS
MORNING...WITH A DEEP TROUGH IN PLACE OVER THE INTERMOUNTAIN WEST,
AND A SECOND DEPARTING TROUGH OVER ATLANTIC CANADA.
CONTINUING TO SEE SOME CLUSTERS OF CONVECTIVE SHRAS/ISO T IN
ASSOCIATION WITH SHORTWAVE ENERGY EJECTING FROM THE TROUGH OVER
THE WEST. THIS ACTIVITY IS EXPECTED TO RIDE THE NW FLOW PATTERN
ALOFT FROM W PA INTO THE MID ATLANTIC REGION BY THIS AFTN. WHILE
DYNAMICS ARE LESS THAN FAVORABLE FOR ANY SIGNIFICANT/WIDESPREAD
TSTM DEVELOPMENT (DIMINISHING EFFECTIVE SHEAR/PERSISTENT MID-
LEVEL CAPPING/MODEST MLCAPE <500 J/KG), EXPECT SOME SCT SHRAS WL
MAKE IT ACROSS AS WEAKENING VORTMAX SWINGS ACROSS THE MASON-DIXON
LINE THROUGH THIS AFTN. LATEST HRRR SEEMS TO BE PERFORMING WELL
ALONGSIDE LATEST SAT/RADAR TRENDS, AND HV THEREFORE INSTALLED
SOME CHC/"SCT" POPS FOR EASTERN SHORE COUNTIES AND FAR NE VA
NORTHERN NECK COUNTIES, MAINLY ALONG AND NORTH OF US-360.
OTEHRWISE, EXPECT A DRY DAY FOR MOST OF THE AREA, WITH LITTLE OR
NO FOCUS FOR ADDITIONAL CONVECTIVE DEVELOPMENT.
DEVELOPING SW FLOW OVER THE SOUTHERN PLAINS AND SOUTHEAST SHOULD
ALLOW THE STATIONARY FRONT TO SHIFT BACK TO THE NORTH THIS
AFTN/TNGT AS A WARM FRONT, WITH MID-HIGH CLOUDS MOVING FROM SW-NE
THROUGH THE DAY. HOWEVER, THE FRONT SHOULD REMAIN S OF THE LOCAL
AREA THROUGH 00Z/8P EDT. HIGHS SHOULD RANGE FROM THE UPPER 60S TO
AROUND 70 OVER THE EASTERN SHORE...TO THE MID/UPPER 70S FROM
INTERIOR NE NC TO CENTRAL VA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
THE STATIONARY FRONT LIFTS NNE LATE TONIGHT INTO THURSDAY MORNING
THROUGH MOST OF THE AREA...BEFORE STALLING IN VICINITY OF THE
LOWER MD EASTERN SHORE. A SECOND, MORE DEFINED SHORTWAVE TROUGH
TRACKS THROUGH THE NW FLOW TONIGHT INTO EARLY THURSDAY. THE BEST
POTENTIAL FOR SHOWERS/TSTMS WILL BE OVER PA/NJ/NRN DE/FAR NE MD.
HOWEVER...PORTIONS OF THE LOCAL AREA (EASTERN SHORE AND NRN NECK)
ARE CLOSE ENOUGH TO THE MID-LEVEL FORCING TO INCLUDED A 20-30%
POP. THUNDER WILL BE INCLUDED BASED ON UPSTREAM
ACTIVITY...MODESTLY STEEP MID-LEVEL LAPSE RATES...AND THETA-E
RIDGING EXTENDING N FROM THE SUBTROPICAL WRN ATLANTIC. CLOUDS
SHOULD GRADUALLY DECREASE FROM SW-NE THURSDAY...BUT THE LOWER MD
EASTERN SHORE COULD REMAIN MOSTLY CLOUDY THROUGH THE DAY. THURSDAY
HAS THE POTENTIAL TO BE THE WARMEST DAY OF THE YEAR SO FAR W OF
THE BAY...WITH HIGHS RANGING FROM THE MID 80S TO AROUND 90. HIGHS
OVER THE EASTERN SHORE SHOULD RANGE FROM THE LOW/MID 70S ALONG THE
IMMEDIATE ATLANTIC COAST...TO THE UPPER 70S/AROUND 80 INLAND.
THE FRONT MAY ACTUALLY DROP BACK S INTO THE EASTERN SHORE AS A
BACKDOOR COLD FRONT THURSDAY NIGHT INTO EARLY FRIDAY...BEFORE
RETREATING NNE FRIDAY AFTERNOON. THIS WILL MAKE FOR A CHALLENGING
TEMPERATURE/SKY COVER FORECAST. NAM/GFS BUFR AT SBY SOUNDINGS SUGGEST
SOME STRATUS COULD COME INLAND FROM THE OCEAN. THIS AND THE ULTIMATE
PLACEMENT OF THE FRONT WILL HAVE A LARGE INFLUENCE ON HIGHS FRIDAY.
THE CURRENT FORECAST IS FOR HIGHS AROUND 70 ALONG THE COAST...TO
MID/UPPER 70S FOR INTERIOR PORTIONS. ELSEWHERE...EXPECT A SUNNY AND
WARM DAY WITH HIGHS IN THE MID/UPPER 80S (LOCALLY LOW 80S COASTAL SE
VA/NE NC).
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
BERMUDA HIGH PRESSURE REMAINS ANCHORED OFF THE SERN COAST THROUGH
THE WEEKEND. LATEST MODEL DATA SLOWS THE APPRCH OF NEXT FRNT ACROSS
THE MTS UNTIL SUNDAY. KEPT FRI NIGHT/SAT MORNING DRY. SCT CONVECTION
PSBL INVOF LEE TROF RESULTING IN DIURNAL POPS SAT AFTN/EVE. LOWS
FRI NIGHT L-M60S. HIGHS SAT 80-85...XCPT M-U70S COASTAL AREAS.
FRONT APPRCHS THE AREA SAT NIGHT THEN WEAKENS/WASHES OUT ACROSS THE
MID ATLNTC RGN SUNDAY. HOWEVER...MODELS NOW WANT TO KEEP THIS WEAKEN
BNDRY/TROF HANGING ARND THE RGN THROUGH ERLY NEXT WEEK. GIVEN THIS
TRIGGER...KEPT CHC SHWRS/TSTMS (20-40%...HIGHEST W OF BAY) IN FCST
THROUGH THE PRD. HIGHS EACH DAY 80-85 EXCEPT REMAINING IN THE 70S
COASTAL SECTIONS. LOWS U50S-M60S.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
THE FRONTAL BOUNDARY TO THE SOUTH WILL SLOWLY MOVE BACK NORTH
STARTING TONIGHT. THE 85H FRONTAL IS MOVING NORTH OF THE AREA THIS
AFTERNOON. THIS HAD SOME SHOWERS AND THUNDERSTORMS WHICH MOVED INTO
THE DELMARVA THIS AFTERNOON. THE 85H FRONT WILL BE WELL NORTH OF THE
AREA LATER TONIGHT SO ANY SHOWERS THAT FORM ALONG IT WILL BE TO THE
NORTH OF THE AREA. THE FRONT TO THE SOUTH HAS SOME LOW LEVEL
MOISTURE WITH IT. THIS COULD BRING CIGS DOWN TO MVFR OVERNIGHT
TONIGHT AS THE BOUNDARY SLOWLY WORKS NORTH. LOOKING AT RUC AND NAM
ON BUFKIT CAN SEE CLOUDS LOWERING AFTER MIDNIGHT ACROSS ALL TAF
SITES. NOT COMPLETELY CONVINCED THE ALL THIS LOW LEVEL MOISTURE WILL
RETURN. SO WILL ONLY BRING MVFR CONDITIONS IN AFTER MIDNIGHT THROUGH
SUNRISE. POTENTIAL FOR THESE CLOUDS TO BE LOWER LATE TONIGHT AND AT
SUNRISE. AFTER SUNRISE CLOUDS RISE QUICKLY AND DISSIPATE AT ALL
SITES AS THE WARM FRONT MOVES NORTH OF THE AREA. THIS WILL ALLOW FOR
VFR CONDITIONS ON THURSDAY. EXPECT MAINLY VFR CONDITIONS THROUGH THE
WEEKEND BUT SCATTERED THUNDERSTORMS WILL DEVELOP BOTH SATURDAY AND
SUNDAY AFTERNOON WHICH COULD BE IFR CONDITIONS FOR A SHORT TIME TO
THE TAF SITES.
&&
.MARINE...
STALLED FRONTAL BOUNDARY REMAINS DRAPED OVER THE CAROLINAS AS HIGH
PRESSURE OVER SE CANADA RIDGES SWD OVER THE WATERS. THE RESULT IS
LIGHT SELY FLOW AOB 10 KT OVER THE WATERS WITH WAVES AND SEAS
GENERALLY 1-2 FT. HIGH PRESSURE LOCATES JUST OFF THE MID-ATLANTIC
COAST THIS AFTERNOON AS THE STALLED FRONTAL BOUNDARY BEGINS TO LIFT
NWD AS A WARM FRONT. AS THIS OCCURS...A WEAK WAVE OF LOW PRESSURE
WILL LIFT ALONG THE FRONT...RESULTING IN A STRENGTHENING PRESSURE
GRADIENT OVER THE WATERS. WINDS ALOFT WILL INCREASE TO 20-25
KT...BUT COOL WATERS AND WARM TEMPS ALOFT WILL RESULT IN AN
INVERSION OVER THE WATERS...PREVENTING THE STRONGER WINDS FROM
MIXING TO THE WATER. HOWEVER...ENOUGH OF A SFC PRESSURE GRADIENT
WILL RESULT IN WINDS AROUND 15 KT OVER THE BAY LATE TODAY INTO EARLY
TONIGHT BEFORE DIMINISHING AFTER MIDNIGHT. A FEW GUSTS UP TO 18-20
KT ARE POSSIBLE...BUT SCA CONDITIONS ARE NOT ANTICIPATED. WARM FRONT
LIFTS OVER THE WATERS TONIGHT INTO THURS...WITH FLOW BECOMING S-SW
BEHIND THE FRONT. SW FLOW PREVAILS THRU THE WEEKEND AS HIGH PRESSURE
ANCHORS OVER THE WRN ATLANTIC...RESULTING IN ONGOING SUB-SCA
CONDITIONS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ/MAM
SHORT TERM...AJZ
LONG TERM...MPR
AVIATION...JAB
MARINE...SAM
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
943 AM EDT WED MAY 7 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS NORTH CAROLINA TODAY.
THE FRONT LIFTS NORTH AS A WARM FRONT TONIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BECOME ANCHORED OFF THE SOUTHEAST COAST
THURSDAY AFTERNOON THROUGH FRIDAY...AS THE FRONTAL BOUNDARY LINGERS
ALONG THE MID ATLANTIC COAST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MID-MORNING WX ANALYSIS FEATURES ~1024MB SFC HIGH PRESSURE OVER
JAMES BAY NOSING SOUTH INTO THE NORTHEAST/MID-ATLANTIC REGION, WITH
A QUASI-STATIONARY FRONTAL BOUNDARY DRAPED WELL SOUTH INTO THE
CAROLINAS. ALOFT, WV/IR IMAGERY SHOWING UPPER LEVEL RIDGE
AXIS EXTENDING FROM THE SOUTHEAST INTO THE TN RVR VALLEY THIS
MORNING...WITH A DEEP TROUGH IN PLACE OVER THE INTERMOUNTAIN WEST,
AND A SECOND DEPARTING TROUGH OVER ATLANTIC CANADA.
CONTINUING TO SEE SOME CLUSTERS OF CONVECTIVE SHRAS/ISO T IN
ASSOCIATION WITH SHORTWAVE ENERGY EJECTING FROM THE TROUGH OVER
THE WEST. THIS ACTIVITY IS EXPECTED TO RIDE THE NW FLOW PATTERN
ALOFT FROM W PA INTO THE MID ATLANTIC REGION BY THIS AFTN. WHILE
DYNAMICS ARE LESS THAN FAVORABLE FOR ANY SIGNIFICANT/WIDESPREAD
TSTM DEVELOPMENT (DIMINISHING EFFECTIVE SHEAR/PERSISTENT MID-
LEVEL CAPPING/MODEST MLCAPE <500 J/KG), EXPECT SOME SCT SHRAS WL
MAKE IT ACROSS AS WEAKENING VORTMAX SWINGS ACROSS THE MASON-DIXON
LINE THROUGH THIS AFTN. LATEST HRRR SEEMS TO BE PERFORMING WELL
ALONGSIDE LATEST SAT/RADAR TRENDS, AND HV THEREFORE INSTALLED
SOME CHC/"SCT" POPS FOR EASTERN SHORE COUNTIES AND FAR NE VA
NORTHERN NECK COUNTIES, MAINLY ALONG AND NORTH OF US-360.
OTEHRWISE, EXPECT A DRY DAY FOR MOST OF THE AREA, WITH LITTLE OR
NO FOCUS FOR ADDITIONAL CONVECTIVE DEVELOPMENT.
DEVELOPING SW FLOW OVER THE SOUTHERN PLAINS AND SOUTHEAST SHOULD
ALLOW THE STATIONARY FRONT TO SHIFT BACK TO THE NORTH THIS
AFTN/TNGT AS A WARM FRONT, WITH MID-HIGH CLOUDS MOVING FROM SW-NE
THROUGH THE DAY. HOWEVER, THE FRONT SHOULD REMAIN S OF THE LOCAL
AREA THROUGH 00Z/8P EDT. HIGHS SHOULD RANGE FROM THE UPPER 60S TO
AROUND 70 OVER THE EASTERN SHORE...TO THE MID/UPPER 70S FROM
INTERIOR NE NC TO CENTRAL VA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
THE STATIONARY FRONT LIFTS NNE LATE TONIGHT INTO THURSDAY MORNING
THROUGH MOST OF THE AREA...BEFORE STALLING IN VICINITY OF THE
LOWER MD EASTERN SHORE. A SECOND, MORE DEFINED SHORTWAVE TROUGH
TRACKS THROUGH THE NW FLOW TONIGHT INTO EARLY THURSDAY. THE BEST
POTENTIAL FOR SHOWERS/TSTMS WILL BE OVER PA/NJ/NRN DE/FAR NE MD.
HOWEVER...PORTIONS OF THE LOCAL AREA (EASTERN SHORE AND NRN NECK)
ARE CLOSE ENOUGH TO THE MID-LEVEL FORCING TO INCLUDED A 20-30%
POP. THUNDER WILL BE INCLUDED BASED ON UPSTREAM
ACTIVITY...MODESTLY STEEP MID-LEVEL LAPSE RATES...AND THETA-E
RIDGING EXTENDING N FROM THE SUBTROPICAL WRN ATLANTIC. CLOUDS
SHOULD GRADUALLY DECREASE FROM SW-NE THURSDAY...BUT THE LOWER MD
EASTERN SHORE COULD REMAIN MOSTLY CLOUDY THROUGH THE DAY. THURSDAY
HAS THE POTENTIAL TO BE THE WARMEST DAY OF THE YEAR SO FAR W OF
THE BAY...WITH HIGHS RANGING FROM THE MID 80S TO AROUND 90. HIGHS
OVER THE EASTERN SHORE SHOULD RANGE FROM THE LOW/MID 70S ALONG THE
IMMEDIATE ATLANTIC COAST...TO THE UPPER 70S/AROUND 80 INLAND.
THE FRONT MAY ACTUALLY DROP BACK S INTO THE EASTERN SHORE AS A
BACKDOOR COLD FRONT THURSDAY NIGHT INTO EARLY FRIDAY...BEFORE
RETREATING NNE FRIDAY AFTERNOON. THIS WILL MAKE FOR A CHALLENGING
TEMPERATURE/SKY COVER FORECAST. NAM/GFS BUFR AT SBY SOUNDINGS SUGGEST
SOME STRATUS COULD COME INLAND FROM THE OCEAN. THIS AND THE ULTIMATE
PLACEMENT OF THE FRONT WILL HAVE A LARGE INFLUENCE ON HIGHS FRIDAY.
THE CURRENT FORECAST IS FOR HIGHS AROUND 70 ALONG THE COAST...TO
MID/UPPER 70S FOR INTERIOR PORTIONS. ELSEWHERE...EXPECT A SUNNY AND
WARM DAY WITH HIGHS IN THE MID/UPPER 80S (LOCALLY LOW 80S COASTAL SE
VA/NE NC).
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
BERMUDA HIGH PRESSURE REMAINS ANCHORED OFF THE SERN COAST THROUGH
THE WEEKEND. LATEST MODEL DATA SLOWS THE APPRCH OF NEXT FRNT ACROSS
THE MTS UNTIL SUNDAY. KEPT FRI NIGHT/SAT MORNING DRY. SCT CONVECTION
PSBL INVOF LEE TROF RESULTING IN DIURNAL POPS SAT AFTN/EVE. LOWS
FRI NIGHT L-M60S. HIGHS SAT 80-85...XCPT M-U70S COASTAL AREAS.
FRONT APPRCHS THE AREA SAT NIGHT THEN WEAKENS/WASHES OUT ACROSS THE
MID ATLNTC RGN SUNDAY. HOWEVER...MODELS NOW WANT TO KEEP THIS WEAKEN
BNDRY/TROF HANGING ARND THE RGN THROUGH ERLY NEXT WEEK. GIVEN THIS
TRIGGER...KEPT CHC SHWRS/TSTMS (20-40%...HIGHEST W OF BAY) IN FCST
THROUGH THE PRD. HIGHS EACH DAY 80-85 EXCEPT REMAINING IN THE 70S
COASTAL SECTIONS. LOWS U50S-M60S.
&&
.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
STALLED FRONTAL BOUNDARY REMAINS DRAPED OVER THE CAROLINAS AS HIGH
PRESSURE BUILDS IN FROM THE NORTHWEST. A WEAK WAVE IN NWLY FLOW
ALOFT IS PRODUCING BKN-OVC SKIES WITH DECKS GENERALLY 6-10K FT AGL
EARLY THIS MORNING. OTHERWISE...WINDS GENERALLY CALM- LESS THAN 5
KT.
FOR TODAY...VFR CONDITIONS PREVAIL AS HIGH PRESSURE BUILDS OFFSHORE.
ADDITIONAL UPPER LEVEL WAVE WILL KEEP SCT-BKN MID LEVEL CLOUDS
AROUND...WITH SOME SCT-BKN LOWER MID-LEVEL CLOUDS (3-5K FT AGL)
OVER SE VA/NE NC. SE WINDS REMAIN GENERALLY AOB 10 KT.
FRONTAL BOUNDARY WILL BEGIN TO LIFT NWD TONIGHT AS A WARM
FRONT...WITH SOME STRATUS POSSIBLE. HOWEVER...MOISTURE RETURN WILL
BE LIMITED...SO DO NOT ANTICIPATE WIDESPREAD STRATUS.
THEREAFTER...VFR CONDITIONS ARE EXPECTED THROUGH THE END OF THE
WEEK. THERE IS A SLIGHT TO LOW END CHANCE OF SHOWERS/THUNDERSTORMS
OVER THE MD ERN SHORE...INCLUDING KSBY TONIGHT AND THURSDAY.
BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS ARE IN PLACE SUNDAY.
&&
.MARINE...
STALLED FRONTAL BOUNDARY REMAINS DRAPED OVER THE CAROLINAS AS HIGH
PRESSURE OVER SE CANADA RIDGES SWD OVER THE WATERS. THE RESULT IS
LIGHT SELY FLOW AOB 10 KT OVER THE WATERS WITH WAVES AND SEAS
GENERALLY 1-2 FT. HIGH PRESSURE LOCATES JUST OFF THE MID-ATLANTIC
COAST THIS AFTERNOON AS THE STALLED FRONTAL BOUNDARY BEGINS TO LIFT
NWD AS A WARM FRONT. AS THIS OCCURS...A WEAK WAVE OF LOW PRESSURE
WILL LIFT ALONG THE FRONT...RESULTING IN A STRENGTHENING PRESSURE
GRADIENT OVER THE WATERS. WINDS ALOFT WILL INCREASE TO 20-25
KT...BUT COOL WATERS AND WARM TEMPS ALOFT WILL RESULT IN AN
INVERSION OVER THE WATERS...PREVENTING THE STRONGER WINDS FROM
MIXING TO THE WATER. HOWEVER...ENOUGH OF A SFC PRESSURE GRADIENT
WILL RESULT IN WINDS AROUND 15 KT OVER THE BAY LATE TODAY INTO EARLY
TONIGHT BEFORE DIMINISHING AFTER MIDNIGHT. A FEW GUSTS UP TO 18-20
KT ARE POSSIBLE...BUT SCA CONDITIONS ARE NOT ANTICIPATED. WARM FRONT
LIFTS OVER THE WATERS TONIGHT INTO THURS...WITH FLOW BECOMING S-SW
BEHIND THE FRONT. SW FLOW PREVAILS THRU THE WEEKEND AS HIGH PRESSURE
ANCHORS OVER THE WRN ATLANTIC...RESULTING IN ONGOING SUB-SCA
CONDITIONS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...AJZ
NEAR TERM...AJZ/MAM
SHORT TERM...AJZ
LONG TERM...MPR
AVIATION...SAM
MARINE...SAM
AREA FORECAST DISCUSSION...CORRECTED
NWS BALTIMORE MD/WASHINGTON DC
407 AM EDT WED MAY 7 2014
.SYNOPSIS...
A STATIONARY FRONT JUST SOUTH OF THE AREA WILL RETURN NORTH AS A
WARM FRONT TODAY. HOWEVER...HIGH PRESSURE BUILDING IN FROM THE NORTH
WILL LIMIT PROGRESSION OF THE FRONT THROUGH THE AREA AND INSTEAD
AN ONSHORE FLOW WILL DEVELOP AS THE HIGH PRESSURE DRIFTS
OFFSHORE. THE FRONT MAY SAG SOUTHWARD AS A BACKDOOR COLD FRONT
THURSDAY NIGHT. HIGH PRESSURE WILL REMAIN PARKED OFF THE SOUTHEAST
COAST LATE IN THE WEEK AND THIS WEEKEND WITH SOUTHERLY RETURN FLOW
YIELDING WARM AND HUMID CONDITIONS.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 08Z...1025MB SFC HIGH SOUTH OF JAMES BAY IN QUEBEC. A
STATIONARY SFC FRONT IS CURRENTLY OVER CENTRAL VA...THOUGH IT IS
DIFFICULT TO PINPOINT FROM SFC OBS/RADAR/SATELLITE. LIGHT SHOWERS
OVER SWRN ZONES HAVE DISSIPATED FOR NOW...BUT REDEVELOPMENT IS
EXPECTED. WITH MID LEVEL LAPSE RATES AROUND 6 C/KM...ELEVATED
THUNDERSTORM DEVELOPMENT IS STILL POSSIBLE...WARRANTING AN
ISOLATED THUNDER MENTION. WILL HAVE TO WATCH THE CONVECTIVE
COMPLEX OVER MI/NWRN OH THAT WILL CONTINUE TO SHIFT SOUTHEAST IN
ELEVATED UNSTABLE AIR. SPC MESOANALYSIS HAS 500 MUCAPE EXTENDING
SOUTHEAST ACROSS THE SWRN HALF OF THE LWX CWA SO AS OF NOW THIS
WOULD SPREAD ACROSS THE CENTRAL OR SOUTHERN PORTION OF THE CWA
LATE THIS MORNING THROUGH MIDDAY. 06Z HRRR DEPICTS SOME REMNANTS
CROSSING NRN/CNTRL PARTS OF THE CWA FROM 10 AM TO 2PM. THIS WILL
ALL BE CLOSELY MONITORED WITH GRID UPDATES AS NECESSARY.
TODAY...WARM FRONT LIFTS NORTH INTO THE AREA WITH CHANCE POPS
SPREADING ACROSS THE DC METRO AREA THROUGH MIDDAY. HOWEVER...AS THE
CANADIAN SFC HIGH PRESSURE SHIFTS SSE ACROSS NJ THIS AFTERNOON...AN
ONSHORE FLOW DEVELOPS FOR THE WRN SHORE. A VORTMAX RIDES THE NWLY
FLOW AS WELL...ALLOWING CHANCE POPS ACROSS NERN MD LATE THIS
AFTERNOON AND EVENING (MAY BE EARLIER WITH ONGOING ACTIVITY ENTERING
OHIO). MAX TEMP UNCERTAINTY TODAY DUE TO TIMING QUESTION OF WARM
FRONT AND ONSHORE FLOW. MAV/MET/GMOS BLEND GAVE GREATER BALTIMORE
AROUND 70F...SLOWLY INCREASING SW FROM THERE WITH MID 70S IN SHEN
VLY AND VLYS WEST OF THERE.
SFC HIGH SETS UP SSE OF DC WITH A SLY FLOW THEN THROUGH THURSDAY.
MAINLY DRY THURSDAY WITH INCREASING TEMPS. QUESTION IS IF ONSHORE
FLOW COMPONENT CAN HANG ON. THEREFORE...LOW 70S IN FOR HARFORD
WITH LOW TO MID 80S FOR MOST OF THE REST OF THE CWA. WILL NEED TO
WATCH FOR 90F IN SOUTHEAST.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
UPPER RIDGE AXIS PROGRESSES EWD OVER THE REGION THU NGT AND FRI
MRNG. MODELS CONTINUE TO ADVERTISE HIPRES OFF THE NEW ENGLAND COAST
RIDGING SWWD INTO THE AREA THU NGT AND A BACKDOOR COLD FRONT TO PUSH
THRU NORTH-CENTRAL MD. ONSHORE FLOW ON THE COOL SIDE OF THE BOUNDARY
COULD RESULT IN DEVELOPMENT OF STRATUS AND PATCHY DRIZZLE THU NGT.
SWLY FLOW WILL STRENGTHEN ON FRI AS THE RIDGE AXIS MOVES OFFSHORE
AND AN UPSTREAM TROUGH APPROACHES FROM THE CENTRAL CONUS. THE HIGH
SUN ANGLE WILL CONTRIBUTE TO STRONG HEATING...ALLOWING ANY STRATUS
EAST OF THE BLUE RIDGE TO MIX OUT BY MIDDAY. WARM AIRMASS UNDERNEATH
THE RIDGE CHARACTERIZED BY +2SD 925 MB TEMPS WILL YIELD HIGHS IN THE
80S. DID RAISE MAX TEMPS A BIT ON FRI WITH SOME WARMER SPOTS IN
CENTRAL VA HAVING THE POTENTIAL TO REACH 90F ASSUMING FULL HEATING.
SUBSIDENCE INVERSION WEAKENS FRI AFTN AND FRI NGT IN ASSOCIATION
WITH HEIGHT FALLS AHEAD OF THE APPROACHING TROUGH WILL HELP ERODE
THE SUBSIDENCE INVERSION. MODELS SHOWING SOME POTENTIAL FOR
CONVECTIVE DEVELOPMENT OVER THE MTS DURING THE PEAK HEATING HRS IN
ASSOCIATION WITH LIFT FROM A LEADING MID-LVL SHORTWAVE ENERGY AND
SFC PRESSURE TROUGH. INTRODUCED ISO COVERAGE OF TSTMS DURING THE
AFTN AND EVE WITH SBCAPE AROUND 1000 J/KG. SHOWERS MAY SPREAD EWD
TOWARD I-95 DURING THE EVE BEFORE MOST OF THE ACTIVITY WANES
OVERNIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MID- AND UPPER-LVL FLOW WILL FLATTEN OUT THIS WEEKEND AS THE MAIN
ENERGY ASSOCIATED WITH AN UPPER TROUGH AND SFC LOW LIFTING NEWD INTO
QUEBEC. A SWLY LLVL JET AHEAD OF THE TROUGH AND ON THE BACKSIDE OF
THE BERMUDA HIGH WILL DRAW MOISTURE FROM THE GULF OF MEXICO TOWARD
THE MID-ATLANTIC REGION. SHOWERS ARE LIKELY ON SAT AS FORCING FOR
ASCENT WITH A SHORTWAVE TROUGH AND WITHIN RIGHT-ENTRANCE REGION OF
ULVL JET STREAK SPREADING INTO THE AREA. CHANCE POPS OVER THE NRN
PIEDMONT AND SRN MD INCREASE TO LIKELY N/W OF DC TO CATEGORICAL
ALONG THE ALLEGHENY FRONT. KEPT AFTN TSTM COVERAGE ISO DUE TO FCST
UNCERTAINTY WITH CLOUD COVER OVER THE AREA. MODEL SOUNDINGS FROM THE
00Z GFS SHOW A RATHER CLOUDY AND STABLE AIRMASS ON SAT WHILE THE 00Z
ECMWF DEPICTS A GREATER POTENTIAL FOR HEATING AND TSTMS.
SYNOPTIC PATTERN EXPECTED TO BECOME FAIRLY ZONAL ACROSS THE ERN HALF
OF THE CONUS SUN AND MON. ABOVE NORMAL TEMPS AND SOMEWHAT HUMID WITH
DEWPOINTS NEAR 60F) WILL CONTINUE THRU ERY NEXT WEEK WITH SLY RETURN
FLOW IN THE LLVLS. ATTEMPTED TO KEEP CHANCES FOR PRECIP LOW DURING
THIS TIME WITH A LACK OF ORGANIZED SYNOPTIC LIFT.
A COLD FRONT WILL APPROACH FROM THE WEST MIDWEEK. STILL PLENTY OF
DIFFERENCES BETWEEN TIMING OF FROPA. FCST FOLLOWS WPC GUIDANCE...
GIVING US INCREASING CHANCES FOR SHOWERS AND STORMS TUE.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
MID LEVEL CLOUDS INCREASE AS WARM FRONT APPROACHES FROM THE SOUTH.
WILL HAVE TO WATCH THUNDERSTORMS MOVING SOUTHEAST FROM CNTRL OH IN
ELEVATED UNSTABLE AIR THIS MORNING THAT WILL APPROACH SOME OF THE
TERMINALS (THOUGH THIS WILL ALSO HAVE TO BE WATCHED) EARLIER THAN
THE GUIDANCE WHICH PROGS LATE AFTERNOON/EVENING. ONSHORE FLOW
DEVELOPS TONIGHT WITH LOW CLOUDS...NEAR IFR THURSDAY MORNING
BEFORE SLY FLOW SLOWLY CLEARS THE CONDS TO VFR FOR THE REST OF
THURSDAY.
A BACKDOOR COLD FRONT SHOULD MOVE THRU BWI-MTN THU NGT AND
POTENTIALLY REACH DCA-IAD. MVFR/IFR CIGS IN STRATUS POSSIBLE THU NGT
AND FRI MRNG ON THE COLD SIDE OF THE BOUNDARY. SCT SHRA AND ISO TSTM
POSSIBLE IN THE MTS FRI AFTN/EVE. BETTER COVERAGE OF SHRA EXPECTED
SAT WITH A DISTURBANCE MOVING THRU THE TERMINALS. IFR VSBYS POSSIBLE
IN HEAVIER SHOWERS OR STORMS. S-SW WINDS MAY GUST 15-25 KT SAT AFTN.
MAINLY VFR THRU THE REMAINDER OF THE WEEKEND.
&&
.MARINE...
NELY FLOW 10 TO 15 KT OVER THE WATERS WILL BECOME ELY THIS AFTERNOON
AS HIGH PRESSURE BUILDS SOUTH TO NJ. WILL NEED TO WATCH THUNDERSTORM
COMPLEX OVER OHIO FOR MIDDAY THUNDERSTORM POTENTIAL FOR THE BAY WITH
ELEVATED INSTABILITY ACROSS THE REGION. FLOW BECOMES ELY THIS
AFTERNOON...ESELY FOR SRN MD WATERS WHICH WILL CHANNEL UP THE TIDAL
POTOMAC AND POSSIBLY THE TIDAL PATUXENT THIS EVENING. MARGINAL SCA
UP FOR LOWER AND MIDDLE TIDAL POTOMAC AS WELL AS LOWER SRN MD WATERS
STARTING THIS AFTERNOON...EXPANDING UP TO NORTH BEACH THIS EVENING.
GUST POTENTIAL IS AROUND 20 KT. FLOW BECOMES MORE LIGHT AND VARIABLE
THURSDAY AS HIGH PRESSURE MOVES SOUTHEAST OF THE AREA AND A WEAK
PRESSURE PATTERN OCCURS OVER THE MD PART OF THE BAY.
LGT SLY WINDS LATE THIS WEEK. A SCA MAY BE NEEDED FOR THE WATERS ON
SAT AS S-SWLY FLOW INCREASES AHEAD OF A TROUGH OF LOPRES.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 2 AM EDT
THURSDAY FOR ANZ533-542.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 2 AM EDT
THURSDAY FOR ANZ534-536-537-543.
&&
$$
SYNOPSIS...JRK
NEAR TERM...BAJ
SHORT TERM...JRK
LONG TERM...JRK
AVIATION...BAJ/JRK
MARINE...BAJ/JRK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
457 PM EDT WED MAY 7 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 407 PM EDT WED MAY 7 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW FAIRLY HI
AMPLITUDE RDG BLDG FM THE SE CONUS INTO THE UPR LKS DOWNSTREAM OF A
DEEP TROF IN THE ROCKIES. THERE ARE TWO CLOSED LOWS EMBEDDED IN THE
TROF. ONE LO IS CENTERED OVER SASKATCHEWAN AND THE OVER THE DESERT
SW. THE LO OVER THE DESERT SW WL HAVE THE MOST IMPACT ON UPR MI WX.
WARM FNT TO THE E OF ASSOCIATED LO PRES IN THE CENTRAL PLAINS IS
EXTENDING E THRU IOWA TOWARD THE LOWER LKS...WITH H85 FNT MOVING N
INTO SRN MN/WI. A PAIR OF ELEVATED CONVECTIVE CLUSTERS THAT MOVED
ENEWD WELL N OF THE WARM FNT IMPACTED MAINLY THE SCENTRAL COUNTIES
THIS MRNG/EARLY AFTN...BUT LINGERING DRY AIR BEST DEPICTED ON THE
12Z APX RAOB AND HIER STABILITY THAT IS PRESENT FARTHER TO THE N PER
LATEST SPC MESOANALYSIS LIMITED THE N PUSH OF THESE SHRA/TS INTO THE
CWA. ABSENCE OF DYNAMIC FORCING OTHER THAN SOME GENERAL WAD/
ISENTROPIC ASCENT UNDER BLDG UPR RDG SO FAR TO THE NE OF MAIN
FORCING MECHANISM CLOSER TO THE DESERT SW UPR LO IS RESULTING IN
MAINLY DRY WX THIS AFTN...WITH MAINLY JUST THICKER HI CLDS IMPACTING
AREAS AWAY FM THE SCENTRAL.
MAIN FCST CONCERNS THRU THU INVOLVE POPS/ELEVATED TS CHCS AND
INTENSITY TO THE N OF APRCHG SFC LO/ATTENDANT WARM FNT AS WELL AS
POTENTIAL FOR FOG DVLPMNT.
TNGT...UPR LO OVER THE DESERT SW IF FCST TO MOVE TO THE NE AND REACH
THE WCENTRAL PLAINS BY 12Z THU. AS THE SFC LO SHIFTS SLOWLY TO THE
NE AS WELL...ATTENDANT SFC WARM FNT IS FCST TO MOVE ONLY SLOWLY TO
THE N INTO SCNTRL WI...BUT THE H85 FNT IS PROGGED TO LIFT MORE
QUICKLY N THRU THE CWA. THE MOST APPRECIABLE DEEP LYR QVECTOR CNVGC/
UPR DVCG THAT IS NOW SUPPORTING MORE NMRS SHRA/SOME TS OVER THE NRN
PLAINS INTO WRN MN IS FCST TO SWING INTO THE AREA FM THE W THIS EVNG
AND IMPACT MAINLY THE NW PORTION OF THE CWA BEFORE EXITING TO THE NE
LATER. AT LEAST SCT SHRA/SOME TS WL LIKELY SHIFT FARTHER TO THE ESE
PARALLEL TO THE APRCHG H85 WARM FNT IN LINE WITH FCST CORFIDI
VECTORS AND TOWARD STEEPER H7-5 LAPSE RATES. SINCE THE CONVECTION WL
BE ELEVATED...PWAT WL BE APRCHG 200 PCT OF NORMAL AS WARMER/MOISTER
AIR WITH H85 DEWPTS UP TO 12C FOLLOWING THE WARM FNT...AND FCST
SDNGS IN THE MORE SATURATED AIRMASS SHOW THIN SKINNY CAPE...SUSPECT
HEAVY RA WL BE THE MAIN THREAT. BUT SOME HAIL MAY FALL OVER THE
STRONGER CELLS MAINLY NEAR THE SRN END OF THE SHRA AREA...WHERE FCST
SDNGS SHOW STEEPER MID LVL LAPSE RATES /ALBEIT WITH A BIT MORE OF A
CAP/ AND H85-3 WIND SHEAR IN THE ELEVATED UNSTABLE LYR IS AOA 40-50
KTS. THIS CAPPING WL BECOME MORE PRONOUNCED LATER FOLLOWING THE H85
WARM FROPA AND TEND TO DIMINISH POPS FM THE SW. AS THE LLVLS TO THE
N OF INCRSGLY SHALLOW WARM FNT INVRN MOISTEN...EXPECT SOME FOG TO
DVLP LATE...MAINLY WHERE THE EXPECTED ESE NEAR SFC FLOW UPSLOPES OFF
LK MI. BUT TENDED TO CUT BACK ON THE FOG FCST TO ACCOUNT FOR STILL
VERY DRY LLVLS. WITH INCRSG MSTR AND THE APRCH OF THE WARM FNT...
EXPECT LTL DIURNAL TEMP FALL.
THU...AS SHRTWV LIFTS TO THE NE AND INTO THE NRN PLAINS BY 00Z
FRI...SFC LO IS FCST TO MOVE INTO SW MN BY 00Z FRI...WITH SFC WARM
FNT TO THE E ARPCHG THE WI BORDER LATE. EXPECT PLENTY OF LO CLD TO
THE N OF INCRSGLY SHALLOW WARM FNTL INVRN WITH SOME FOG AS WELL IN
AREAS THAT EXPERIENCE UPSLOPE FLOW WITH THE LLVL SE WIND TO THE N OF
THE FNT. BEST CHC FOR MORE NMRS SHRA/TS WL BE IN THE MRNG OVER THE
NE HALF BEFORE CAPPING BEHIND H85 WARM FROPA/AREA OF DEEP LYR
FORCING SHIFT TO THE NE AND GIVE WAY TO LARGER SCALE QVECTOR DVGC/
STRENGTHENING OF CAPPING INVRN. PREFER THE 12Z REGIONAL CNDN MODEL
HANDLING OF THE POPS SHIFTED A BIT TO THE NE TOWARD THE LARGER SCALE
FORCING AND AWAY FM LIKELY CAP. BEST CHC FOR SOME SUNSHINE WL BE
OVER THE W IN THE AFTN WITH DOWNSLOPE SE WIND UNDER MID LVL CAPPING/
DRYING. HI TEMPS WL AT LEAST APRCH 70 IN THIS AREA. LINE OF SHRA/TS
FED BY THIS HEATING AND CLOSER APRCH OF THE LO MAY MOVE INTO THE FAR
W LATE IN THE DAY. THE CURRENT SPC OUTLOOK INDICATES FAR WRN UPR MI
IS UNDER THE SLGT RISK FOR SVR STORMS. WITH SFC-6KM BULK SHEAR
VALUES APRCHG 40-50KTS TOWARD 00Z IN THIS AREA AT THE TIME THE LINE
OF CVNCTN MIGHT BE ARRIVING LATE IN THE DAY AHEAD OF THE SHARPER
DEEP LYR QVECTOR CNVGC AND FCST MUCAPE AOA 1000J/KG...STRONGER
STORMS WL BE PSBL IF SFC BASED PARCELS CAN BREAK THRU THE CAP.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 449 PM EDT WED MAY 7 2014
MODELS ADVERTISE A FAIRLY ACTIVE SPRING WEATHER PATTERN FOR THE
UPPER GREAT LAKES REGION FROM LATE THIS WEEK INTO THE FIRST HALF OF
NEXT WEEK AS A MEAN MID-UPPER LEVEL TROUGH PERSISTS OVER THE WESTERN
HALF OF THE CONTINENT ALLOWING FOR A SERIES OF SW FLOW SHORTWAVES TO
BRING PERIODIC SHOWERS TO THE FCST AREA.
BEGINNING THU NIGHT INTO FRI...A SHORTWAVE NOW NEAR THE
AZ/MEXICO BORDER ROUNDING THE BASE OF THE WRN CONUS TROF IS EXPECTED
TO LIFT NE THROUGH THE SRN ROCKIES AND CENTRAL PLAINS TONIGHT INTO
THURSDAY. MODELS INDICATE THIS SHORTWAVE AND ITS ASSOC 3H JET MAX
WILL TRACK ACROSS WESTERN LAKE SUPERIOR THU NIGHT INTO FRI MORNING
WITH THE BEST MID-LVL Q-VECT CONVERGENCE AND UPPER DIVERGENCE
STAYING NW OF THE FCST AREA. BUT DESPITE THE LACK OF FAVORABLE
DYNAMICS OVER THE AREA...THE SHORTWAVE WILL DRIVE A WARM FRONT
TOWARD THE UPPER GREAT LAKES LATE THU AND THEN PUSH THE SFC LOW AND
ASSOC COLD FRONT INTO THE WRN PORTION OF THE CWA LATE THU NIGHT INTO
EARLY FRI INCREASING LOW-LVL CONVERGENCE. DEPENDING ON EVOLUTION OF
CONVECTION ALONG INCOMING WARM FRONT...POOLING OF LOW-LVL MOISTURE
AND SOME ELEVATED INSTABILITY TO NEAR 500 J/KG ALONG WITH BULK SHEAR
VALUES TO NEAR 40 KT COULD RESULT IN SOME STRONGER STORMS MAINLY NEAR
THE WI BDR COUNTIES THU EVENING. HOWEVER...GIVEN HOW CAPPED LOW-
LEVELS ARE FROM FCST SNDGS WOULD THINK THREAT OF SVR WOULD BE PRETTY
MINIMAL. OTHERWISE...WEAKENING INSTABILITY SHOULD RESULT IN JUST A
GENERAL THUNDERSTORM RISK LATE THU NIGHT INTO FRIDAY ALONG AND AHEAD
OF COLD FRONTAL PASSAGE.
FRI NIGHT AND SATURDAY...EXPECT DRIER CONDITIONS AS A MID-LVL
SHORTWAVE RIDGE AND ASSOC SFC RDG BUILD IN FM WEST BEHIND THE
FRIDAYS FRONTAL SYSTEM. TEMPS RIGHT ALONG LAKE SUPERIOR WILL LIKELY
BE COOL ON SATURDAY (GENERALLY IN THE 50S) IN A LIGHT NRLY FLOW BUT
FARTHER INLAND OVER THE INTERIOR WEST HALF LOWER TO MID 60S CAN BE
EXPECTED UNDER PREVALENT SUNSHINE.
SAT NIGHT...MODELS SHOW THE NEXT SW FLOW SHORTWAVE RIPPLING THROUGH
THE UPPER LAKES. WAA ASSOC WITH THIS SHORTWAVE WILL BRING ANOTHER
ROUND OF SCT SHRA TO THE AREA.
MODELS MORE UNCERTAIN ON EVOLVING PATTERN DETAILS FOR SUNDAY INTO
NEXT WED AS A PACIFIC SHORTWAVE DIGS SE...DEEPENING MID-UPR LVL TROF
OVER THE SW CONUS FOR EARLY NEXT WEEK. BOTH THE ECMWF AND GEM-NH
SHOW A MORE AMPLIFIED MID-UPR LEVEL TROF DEVELOPING OVER THE
ROCKIES/WRN PLAINS FOR EARLY NEXT WEEK ALLOWING FOR A SOUTHERLY FLOW
OF GULF MOISTURE AHEAD OF THE ASSOC FRONTAL SYSTEM TO WORK ITS WAY
NORTH INTO THE UPPER GREAT LAKES REGION. THE GFS ON THE OTHER HAND
IS LESS AMPLIFIED AND MORE PROGRESSIVE WITH THIS FRONT MOVING IT
THROUGH RATHER QUICKLY SUN NIGHT INTO EARLY MONDAY. DECIDED TO GO
ALONG MORE WITH NCEP PREFERRED SLOWER/MORE AMPLIFIED ECMWF/GEM IDEA
WHICH SHOULD YIELD MORE SHOWERS OVER THE UPPER GREAT
LAKES...ESPECIALLY MONDAY INTO MONDAY NIGHT. ALSO INCLUDED A SLIGHT
CHC FOR TSRA OVER MUCH OF THE CWA ON MON NIGHT AND FOR THE ERN
PORTION OF CWA ON TUE AS ECMWF INDICATES NEG SHOWALTER INDICES IN
WARM SECTOR AHEAD OF FRONTAL PASSAGE. MODELS SUGGEST DRIER AND
COOLER CONDITIONS TUE NIGHT INTO WED IN THE WAKE OF THE COLD FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 407 PM EDT WED MAY 7 2014
ALTHOUGH THERE WL BE PLENTY OF HI AND MID CLDS ARND INTO THIS
EVNG...PERSISTENT DRY ESE FETCH WL MAINTAIN VFR WX AT ALL 3 TAF
SITES THRU AT LEAST SUNSET. BUT THE ARRIVAL OF MORE SHRA AND
POSSIBLY A TS BY LATE EVNG AS WELL AS AN APRCHG WARM FNT/LOWERING
INVRN/INCRSGLY MOIST AIRMASS TAPPED BY THE SE FLOW...EXPECT MVFR
CONDITIONS TO DVLP LATE TNGT AT SAW AND CMX...WHERE THIS FLOW WL
UPSLOPE. DOWNSLOPE NATURE OF THE WIND AT IWD SHOULD MAINTAIN VFR
CONDITIONS THERE. SOME MARGINAL LLWS MAY IMPACT ALL 3 SITES WITH THE
STRENGTHENING/LOWERING FRONTAL INVRN...ESPECIALLY AT CMX WHERE THE
LLVL WINDS ABV THE MORE STABLE NEAR SFC LYR WL BE STRONGER. MORE
LLVL MOISTENING AHEAD OF APRCHG SFC WARM FNT WL CAUSE CIGS TO DROP
INTO THE IFR RANGE AT CMX AND SAW AND TO MVFR AT IWD ON THU MRNG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 PM EDT WED MAY 7 2014
EXPECT ENE WINDS UP TO 25 KTS TO VEER TO THE SE THRU THU AS LO PRES
IN THE PLAINS APPROACHES THE AREA. THE STRONGEST WINDS ARE MOST
LIKELY OVER THE W HALF OF LAKE SUPERIOR...WHERE THE TERRAIN WILL
FUNNEL AND ENHANCE THE WINDS. SINCE THE LOW LEVEL AIR IS DRIER THAN
EARLIER EXPECTED...TENDED TO SLOW DOWN THE ARRIVAL OF FOG AND CUT
BACK ON THE COVERAGE. BUT AS MORE HUMID AIR MOVES IN LATER IN THE
DAY AND THU NIGHT WITH A WIND SHIFT TO THE S AHEAD OF THE LO MOVING
THRU MN...THE FOG SHOULD BECOME WIDESPREAD AND PERHAPS LOCALLY DENSE.
THE LO WILL CONTINUE NE TOWARD JAMES BAY ON FRIDAY AND DRAG A
TRAILING COLD FRONT ACROSS LAKE SUPERIOR DURING THE DAY...SHIFTING
WINDS TO THE W. A HI PRES RIDGE WILL MOVE OVER THE LAKE ON FRI NIGHT
AND REMAIN INTO SATURDAY...LEADING TO LIGHT WINDS. AS THE HI SHIFTS
TO THE E AND ANOTHER DISTURBANCE APPROACHES FROM THE NW AND THEN
PASSES ON MON...THE LLVL WINDS WILL VEER TO THE SSW AHEAD OF THE
DISTURBANCE AND THEN THE TO NW FOLLOWING ITS PASSAGE EARLY MON.
&&
.HYDROLOGY...
ISSUED AT 449 PM EDT WED MAY 7 2014
WITH THE RECENT DRIER AND COOLER WEATHER...RIVER AND STREAM LEVELS
HAVE SLOWLY COME DOWN OVER THE LAST 24 HOURS...ALTHOUGH THE STURGEON
RIVER NEAR CHASSELL REMAINS CLOSE TO BANKFULL.
WET WEATHER WILL RETURN TONIGHT INTO FRIDAY. MOST OF THE
RAIN LOOKS TO FALL OVER THE STURGEON RIVER BASIN THURSDAY EVENING.
ADDING TO THIS WILL BE A FEW INCHES OF SNOW WATER EQUIVALENT SHOWN
FROM NOHRSC MODEL FROM THE TIP OF THE KEWEENAW PENINSULA THROUGH
PAINESDALE...DONKEN...AND WINONA. THIS LINES UP WELL WITH THE LATEST
SNOW DEPTHS REPORTED AT PAINESDALE AND HERMAN. WILL SEE HOW THIS
SNOW MELT /WARMER FCST TEMPS FOR THE REST OF THE WEEK/ IMPACT
DOWNSTREAM RIVERS INCLUDING THE STURGEON RIVER OF BARAGA/HOUGHTON
COUNTIES AND THE TRAP ROCK RIVER. MOST IF NOT ALL OF THE SNOW COULD
MELT BY THIS WEEKEND. SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS
WILL AFFECT THE AREA TONIGHT INTO EARLY FRIDAY. RAINFALL
AMOUNTS WILL LIKELY EXCEED A HALF OF AN INCH FOR MOST OF UPPER
MICHIGAN...AND LOCALIZED AMOUNTS OVER AN INCH SHOULD OCCUR WHERE
THUNDERSTORMS TRACK. THIS WILL KEEP THE RIVER LEVELS HIGH INTO EARLY
NEXT WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD
CONTINUE TO MONITOR RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...VOSS
AVIATION...KC
MARINE...KC
HYDROLOGY...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
408 PM EDT WED MAY 7 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 407 PM EDT WED MAY 7 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW FAIRLY HI
AMPLITUDE RDG BLDG FM THE SE CONUS INTO THE UPR LKS DOWNSTREAM OF A
DEEP TROF IN THE ROCKIES. THERE ARE TWO CLOSED LOWS EMBEDDED IN THE
TROF. ONE LO IS CENTERED OVER SASKATCHEWAN AND THE OVER THE DESERT
SW. THE LO OVER THE DESERT SW WL HAVE THE MOST IMPACT ON UPR MI WX.
WARM FNT TO THE E OF ASSOCIATED LO PRES IN THE CENTRAL PLAINS IS
EXTENDING E THRU IOWA TOWARD THE LOWER LKS...WITH H85 FNT MOVING N
INTO SRN MN/WI. A PAIR OF ELEVATED CONVECTIVE CLUSTERS THAT MOVED
ENEWD WELL N OF THE WARM FNT IMPACTED MAINLY THE SCENTRAL COUNTIES
THIS MRNG/EARLY AFTN...BUT LINGERING DRY AIR BEST DEPICTED ON THE
12Z APX RAOB AND HIER STABILITY THAT IS PRESENT FARTHER TO THE N PER
LATEST SPC MESOANALYSIS LIMITED THE N PUSH OF THESE SHRA/TS INTO THE
CWA. ABSENCE OF DYNAMIC FORCING OTHER THAN SOME GENERAL WAD/
ISENTROPIC ASCENT UNDER BLDG UPR RDG SO FAR TO THE NE OF MAIN
FORCING MECHANISM CLOSER TO THE DESERT SW UPR LO IS RESULTING IN
MAINLY DRY WX THIS AFTN...WITH MAINLY JUST THICKER HI CLDS IMPACTING
AREAS AWAY FM THE SCENTRAL.
MAIN FCST CONCERNS THRU THU INVOLVE POPS/ELEVATED TS CHCS AND
INTENSITY TO THE N OF APRCHG SFC LO/ATTENDANT WARM FNT AS WELL AS
POTENTIAL FOR FOG DVLPMNT.
TNGT...UPR LO OVER THE DESERT SW IF FCST TO MOVE TO THE NE AND REACH
THE WCENTRAL PLAINS BY 12Z THU. AS THE SFC LO SHIFTS SLOWLY TO THE
NE AS WELL...ATTENDANT SFC WARM FNT IS FCST TO MOVE ONLY SLOWLY TO
THE N INTO SCNTRL WI...BUT THE H85 FNT IS PROGGED TO LIFT MORE
QUICKLY N THRU THE CWA. THE MOST APPRECIABLE DEEP LYR QVECTOR CNVGC/
UPR DVCG THAT IS NOW SUPPORTING MORE NMRS SHRA/SOME TS OVER THE NRN
PLAINS INTO WRN MN IS FCST TO SWING INTO THE AREA FM THE W THIS EVNG
AND IMPACT MAINLY THE NW PORTION OF THE CWA BEFORE EXITING TO THE NE
LATER. AT LEAST SCT SHRA/SOME TS WL LIKELY SHIFT FARTHER TO THE ESE
PARALLEL TO THE APRCHG H85 WARM FNT IN LINE WITH FCST CORFIDI
VECTORS AND TOWARD STEEPER H7-5 LAPSE RATES. SINCE THE CONVECTION WL
BE ELEVATED...PWAT WL BE APRCHG 200 PCT OF NORMAL AS WARMER/MOISTER
AIR WITH H85 DEWPTS UP TO 12C FOLLOWING THE WARM FNT...AND FCST
SDNGS IN THE MORE SATURATED AIRMASS SHOW THIN SKINNY CAPE...SUSPECT
HEAVY RA WL BE THE MAIN THREAT. BUT SOME HAIL MAY FALL OVER THE
STRONGER CELLS MAINLY NEAR THE SRN END OF THE SHRA AREA...WHERE FCST
SDNGS SHOW STEEPER MID LVL LAPSE RATES /ALBEIT WITH A BIT MORE OF A
CAP/ AND H85-3 WIND SHEAR IN THE ELEVATED UNSTABLE LYR IS AOA 40-50
KTS. THIS CAPPING WL BECOME MORE PRONOUNCED LATER FOLLOWING THE H85
WARM FROPA AND TEND TO DIMINISH POPS FM THE SW. AS THE LLVLS TO THE
N OF INCRSGLY SHALLOW WARM FNT INVRN MOISTEN...EXPECT SOME FOG TO
DVLP LATE...MAINLY WHERE THE EXPECTED ESE NEAR SFC FLOW UPSLOPES OFF
LK MI. BUT TENDED TO CUT BACK ON THE FOG FCST TO ACCOUNT FOR STILL
VERY DRY LLVLS. WITH INCRSG MSTR AND THE APRCH OF THE WARM FNT...
EXPECT LTL DIURNAL TEMP FALL.
THU...AS SHRTWV LIFTS TO THE NE AND INTO THE NRN PLAINS BY 00Z
FRI...SFC LO IS FCST TO MOVE INTO SW MN BY 00Z FRI...WITH SFC WARM
FNT TO THE E ARPCHG THE WI BORDER LATE. EXPECT PLENTY OF LO CLD TO
THE N OF INCRSGLY SHALLOW WARM FNTL INVRN WITH SOME FOG AS WELL IN
AREAS THAT EXPERIENCE UPSLOPE FLOW WITH THE LLVL SE WIND TO THE N OF
THE FNT. BEST CHC FOR MORE NMRS SHRA/TS WL BE IN THE MRNG OVER THE
NE HALF BEFORE CAPPING BEHIND H85 WARM FROPA/AREA OF DEEP LYR
FORCING SHIFT TO THE NE AND GIVE WAY TO LARGER SCALE QVECTOR DVGC/
STRENGTHENING OF CAPPING INVRN. PREFER THE 12Z REGIONAL CNDN MODEL
HANDLING OF THE POPS SHIFTED A BIT TO THE NE TOWARD THE LARGER SCALE
FORCING AND AWAY FM LIKELY CAP. BEST CHC FOR SOME SUNSHINE WL BE
OVER THE W IN THE AFTN WITH DOWNSLOPE SE WIND UNDER MID LVL CAPPING/
DRYING. HI TEMPS WL AT LEAST APRCH 70 IN THIS AREA. LINE OF SHRA/TS
FED BY THIS HEATING AND CLOSER APRCH OF THE LO MAY MOVE INTO THE FAR
W LATE IN THE DAY. THE CURRENT SPC OUTLOOK INDICATES FAR WRN UPR MI
IS UNDER THE SLGT RISK FOR SVR STORMS. WITH SFC-6KM BULK SHEAR
VALUES APRCHG 40-50KTS TOWARD 00Z IN THIS AREA AT THE TIME THE LINE
OF CVNCTN MIGHT BE ARRIVING LATE IN THE DAY AHEAD OF THE SHARPER
DEEP LYR QVECTOR CNVGC AND FCST MUCAPE AOA 1000J/KG...STRONGER
STORMS WL BE PSBL IF SFC BASED PARCELS CAN BREAK THRU THE CAP.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 449 AM EDT WED MAY 7 2014
NAM SHOWS A 500 MB RIDGE OVER THE UPPER GREAT LAKES 12Z THU WITH A
TROUGH OVER THE ROCKIES 12Z THU AND THIS TROUGH HEADS EAST INTO THE
NORTHERN PLAINS ON THU AND INTO THE UPPER GREAT LAKES ON FRI. NAM
BRINGS IN SOME ISENTROPIC LIFT AND MOISTURE ON I290K-I305K SURFACES
ON THU WITH THE LIFT MOVING OUT OF THE AREA THU NIGHT. NAM ALSO
BRINGS IN SOME 850-500 MB Q-VECTOR CONVERGENCE ON THU THAT LASTS
INTO FRI MORNING BEFORE DEPARTING. GFS SHOWS ABOUT THE SAME THING.
BASICALLY...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST.
TRYING TO FIGURE OUT THE CONVECTION IS TOUGH AND BROADBRUSHED IT FOR
THE MOST PART WITH SCATTERED TO NUMEROUS POPS IN FOR THU. THU NIGHT
LOOKS TO BE THE BEST CHANCE FOR PCPN AS THE WARM FRONT MOVES THROUGH
AND WENT CATEGORICAL OVER THE WEST. HAVE A DRY SLOT MOVING THROUGH
ON FRIDAY WITH DIMINISHING POPS. DID NOT MAKE TOO MANY CHANGES TO
THE TEMPERATURES OVERALL. STILL LOOKS LIKE FOG IS A GOOD BET
ESPECIALLY THU NIGHT ACROSS THE AREA.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE
WESTERN U.S. WITH A TROUGH OVER THE UPPER GREAT LAKES 12Z SAT. THE
TROUGH IN THE WESTERN U.S. DIGS INTO THE ROCKIES 12Z SUN WITH A
SHORTWAVE MOVING INTO THE UPPER GREAT LAKES. THIS TROUGH DIGS
FURTHER INTO THE ROCKIES 12Z MON AND INTO THE PLAINS 12Z TUE. WHAT
THIS WILL MEAN FOR THE AREA IS THE WEATHER WILL REMAIN UNSETTLED
THROUGH THE PERIOD WITH THE ONLY DRY PERIOD LOOKING LIKE IT WILL BE
SATURDAY. OTHERWISE...THERE WILL BE SLIGHT CHANCE TO CHANCE POPS IN
FOR THE REST OF THE PERIOD. TEMPERATURES WILL REMAIN BELOW NORMAL
FOR THIS FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 407 PM EDT WED MAY 7 2014
ALTHOUGH THERE WL BE PLENTY OF HI AND MID CLDS ARND INTO THIS
EVNG...PERSISTENT DRY ESE FETCH WL MAINTAIN VFR WX AT ALL 3 TAF
SITES THRU AT LEAST SUNSET. BUT THE ARRIVAL OF MORE SHRA AND
POSSIBLY A TS BY LATE EVNG AS WELL AS AN APRCHG WARM FNT/LOWERING
INVRN/INCRSGLY MOIST AIRMASS TAPPED BY THE SE FLOW...EXPECT MVFR
CONDITIONS TO DVLP LATE TNGT AT SAW AND CMX...WHERE THIS FLOW WL
UPSLOPE. DOWNSLOPE NATURE OF THE WIND AT IWD SHOULD MAINTAIN VFR
CONDITIONS THERE. SOME MARGINAL LLWS MAY IMPACT ALL 3 SITES WITH THE
STRENGTHENING/LOWERING FRONTAL INVRN...ESPECIALLY AT CMX WHERE THE
LLVL WINDS ABV THE MORE STABLE NEAR SFC LYR WL BE STRONGER. MORE
LLVL MOISTENING AHEAD OF APRCHG SFC WARM FNT WL CAUSE CIGS TO DROP
INTO THE IFR RANGE AT CMX AND SAW AND TO MVFR AT IWD ON THU MRNG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 PM EDT WED MAY 7 2014
EXPECT ENE WINDS UP TO 25 KTS TO VEER TO THE SE THRU THU AS LO PRES
IN THE PLAINS APPROACHES THE AREA. THE STRONGEST WINDS ARE MOST
LIKELY OVER THE W HALF OF LAKE SUPERIOR...WHERE THE TERRAIN WILL
FUNNEL AND ENHANCE THE WINDS. SINCE THE LOW LEVEL AIR IS DRIER THAN
EARLIER EXPECTED...TENDED TO SLOW DOWN THE ARRIVAL OF FOG AND CUT
BACK ON THE COVERAGE. BUT AS MORE HUMID AIR MOVES IN LATER IN THE
DAY AND THU NIGHT WITH A WIND SHIFT TO THE S AHEAD OF THE LO MOVING
THRU MN...THE FOG SHOULD BECOME WIDESPREAD AND PERHAPS LOCALLY DENSE.
THE LO WILL CONTINUE NE TOWARD JAMES BAY ON FRIDAY AND DRAG A
TRAILING COLD FRONT ACROSS LAKE SUPERIOR DURING THE DAY...SHIFTING
WINDS TO THE W. A HI PRES RIDGE WILL MOVE OVER THE LAKE ON FRI NIGHT
AND REMAIN INTO SATURDAY...LEADING TO LIGHT WINDS. AS THE HI SHIFTS
TO THE E AND ANOTHER DISTURBANCE APPROACHES FROM THE NW AND THEN
PASSES ON MON...THE LLVL WINDS WILL VEER TO THE SSW AHEAD OF THE
DISTURBANCE AND THEN THE TO NW FOLLOWING ITS PASSAGE EARLY MON.
&&
.HYDROLOGY...
ISSUED AT 449 AM EDT WED MAY 7 2014
STREAMS AND RIVERS WILL CONTINUE TO EXPERIENCE HIGHER LEVELS.
LOCATIONS STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE
STURGEON RIVER IN HOUGHTON AND BARAGA COUNTIES.
WET WEATHER WILL RETURN TONIGHT THROUGH FRIDAY EVENING. MOST OF THE
RAIN LOOKS TO FALL OVER THE STURGEON RIVER BASIN THURSDAY EVENING.
ADDING TO THIS WILL BE THE FEW INCHES OF SNOW WATER EQUIVALENT BEING
SHOWN FROM NOHRSC SET UP FROM THE TIP OF THE KEWEENAW PENINSULA
THROUGH PAINESDALE...DONKEN...AND WINONA. THIS LINES UP WELL WITH
THE LATEST SNOW DEPTHS REPORTED AT PAINESDALE AND HERMAN. WILL SEE
HOW THIS SNOW MELT /GIVEN WARMER FCST TEMPS FOR THE REST OF THE
WEEK/ IMPACTS DOWNSTREAM RIVERS INCLUDING THE STURGEON RIVER OF
BARAGA/HOUGHTON COUNTIES AND THE TRAP ROCK RIVER. MOST IF NOT ALL OF
THE SNOW COULD MELT BY THIS WEEKEND. SEVERAL ROUNDS OF SHOWERS AND
THUNDERSTORMS WILL AFFECT THE AREA TONIGHT THROUGH FRIDAY NIGHT.
RAINFALL AMOUNTS WILL LIKELY EXCEED A HALF OF AN INCH FOR MOST OF
UPPER MICHIGAN...AND LOCALIZED AMOUNTS OVER AN INCH SHOULD OCCUR
WHERE THUNDERSTORMS TRACK. THIS WILL KEEP THE RIVER LEVELS HIGH INTO
EARLY NEXT WEEK. THOSE LIVING AROUND RIVERS...CREEKS...AND
STREAMS SHOULD CONTINUE TO MONITOR RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...07
AVIATION...KC
MARINE...KC
HYDROLOGY...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
416 AM EDT WED MAY 7 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 322 PM EDT TUE MAY 6 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW BLDG UPR RDG/SFC
HI PRES OVER THE UPR LKS BTWN TROF IN FAR ERN CANADA AND A PAIR OF
CLOSED LOWS IN SPLIT FLOW ACRS THE W...ONE OVER ALBERTA AND THE
OTHER DIGGING INTO THE DESERT SW. 12Z GRB/APX/MPX RAOBS INDICATE A
DRY...STABLE AIRMASS IS IN PLACE...WITH PWAT AS LO AS 0.25 INCH AT
APX. BUT THERE ARE PLENTY OF MID/HI CLDS ASSOCIATED WITH WAD/
ISENTROPIC ASCENT IN THE SW FLOW ALF BTWN THE HI OVER THE UPR LKS
AND LOWER HGTS/MSLP TO THE W ASSOCIATED WITH THE WRN TROFFING. THERE
IS A BAND OF THICKER MID LVL CLDS MOVING ENEWD THRU NE MN/WRN LK SUP
AND TOWARD THE WRN LAND CWA ASSOCIATED WITH SHARPER ISENTROPIC ASCENT
BEST SHOWN ON THE 300-305K SFCS...OR ABOUT H6-7...WELL TO THE NE OF
DVLPG SFC-H85 WARM FNT IN THE CENTRAL PLAINS. BUT ADVECTION OF DRIER
AIR IN THE LLVLS WITH STEADY ESE WINDS ON THE WRN FLANK OF THE SFC HI
IS PREVENTING ANY PCPN FM REACHING THE GROUND E OF FAR WRN LK SUP.
MAIN FCST CONCERN IN THE SHORTER TERM FOCUS ON PCPN CHCS ASSOCIATED
WITH LARGER SCALE WAD/ISENTROPIC ASCENT TO THE NE OF WARM FNT NOW IN
THE CENTRAL PLAINS.
THIS AFTN/TNGT...ALTHOUGH HI CLDS WL SPILL OVER THE ENTIRE CWA THIS
AFTN...BAND OF THICKER MID CLDS IS FCST TO IMPACT MAINLY THE NW
PORTIONS OF THE CWA THIS AFTN BEFORE SHIFTING TO THE NE AFT SUNSET.
THE LLVLS SHOULD REMAIN SUFFICIENTLY DRY TO KEEP PCPN FM REACHING THE
SFC EVEN WHERE THE CLDS ARE THICKEST. THE PERIOD FM 00Z-06Z SHOULD BE
DRY DESPITE CONSIDERABLE HI CLDS. WITH AN INCRSG H85 SW LLJ/THETA E
ADVCTN/DEEP LYR QVECTOR CNVGC TNGT...MORE NMRS SHRA/TS ARE LIKELY TO
DVLP AHEAD OF THE WARM FNT MOVING SLOWLY TO THE NE TOWARD SRN MN/WI
BY 12Z. BUT SINCE THE SHARPER DEEP LYR QVECTOR CNVGC AND UPR DVGC ARE
FCST TO REMAIN S OF UPR MI CLOSER TO THE WARM FNT...CORFIDI VECTORS
FCST TO BE WNW IN WI TO THE N OF THE H85 WARM FNT WHICH WOULD RESULT
IN MOST NMRS SHRA/TS REMAINING TO THE S AND ROBBING MSTR FOR PCPN
FARTHER N...AND DRY AIR IS FCST TO LINGER IN THE SFC-H7 LYR WITHIN
PERSISTENT ESE LLVL TRAJECTORIES...SUSPECT THE 12Z GFS IS TOO
AGGRESSIVE TO LIFT PCPN INTO MUCH OF UPR MI BY 12Z WED. WL TREND THE
FCST CLOSER TO THE DRIER 12Z NAM/REGIONAL CNDN MODELS. THIS GUIDANCE
RESTRICTS QPF TO AREAS NEAR THE WI BORDER AND BAND OF SHARPER H85
FGEN. WL FCST HIER CHC POPS OVER SRN MENOMINEE COUNTY BUT GO WITH A
DRY FCST FOR THE NE CWA.
WED...SFC WARM FNT NEAR THE SRN MN/WI BORDER AND H85 WARM FNT INTO
CENTRAL WI IS FCST TO REMAIN NEARLY STNRY THRU 00Z THU WELL TO THE NE
OF DEEP TROF LINGERING IN THE DESERT SW. WELL TO THE NE OF THIS MAIN
FORCING MECHANISM...12Z MODELS INDICATE DEEP LYR QVECTOR DVGC/SOME
UPR CNVGC WL DOMINATE THRU MUCH OF THE AFTN UNDER INCRSGLY AMPLIFIED
UPR RDG/HGT RISES TO THE N OF THE WARM FNT AND DIMINISHING DEEP LYR
QVECTOR CNVGC THAT WL SUPPORT THE MAIN AREA OF SHRA/TS TO THE S AND
SHIFT MAINLY TO THE E INTO THE LOWER LKS PARALLEL TO THE WARM FNT. SO
SUSPECT THE MORE NMRS SHRA WL EXIT THE FAR SCENTRAL EARLY IN THE DAY
AND LEAVE JUST ISOLD-SCT SHRA NEAR THE WI BORDER MOST OF THE DAY.
INCLUDED MENTION OF SOME ELEVATED TS OVER THE FAR SCENTRAL LATER IN
THE DAY TO ACCOUNT FOR AREA OF FCST LOWER SSI SHOWN BY THE MORE
STABLE GFS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 441 PM EDT TUE MAY 6 2014
WHEN...WHERE...AND HOW MUCH PRECIPITATION WILL FALL ALONG WITH THE
THUNDERSTORM POTENTIAL WILL BE THE MAIN CONCERNS IN THIS LONG TERM
PERIOD. THE SLIGHT RISK TS POTENTIAL FROM SPC IS ALONG THE WI BORDER
FOR THE WEDNESDAY NIGHT PERIOD. ANOTHER CONCERN WITH THE WARMER AIR
WILL BE FOG...WHICH IS STILL FCST TUESDAY NIGHT THROUGH
FRIDAY...PARTICULARLY ACROSS LAKE SUPERIOR AND LAKE MI.
THE 500MB LOW CURRENTLY ALONG THE ALBERTA AND SASKATCHEWAN BORDER
AND TROUGH EXTENDING ACROSS NV AND S CA THIS AFTERNOON WILL EVER SO
SLOWLY PROGRESS E...STRETCHING FROM SASKATCHEWAN THROUGH THE
4-CORNERS REGION BY 06Z THURSDAY...AS THE HIGH AMPLITUDE RIDGE
CONTINUES TO BUILD ACROSS THE UPPER GREAT LAKES /WITH THE APEX OVER
MAINLY CENTRAL AND E UPPER MI/.
WENT WITH HIGH CHANCE TO LIKELY POPS FOR THE W HALF OF UPPER MI
WEDNESDAY NIGHT...SO DESPITE THE SE WINDS...TEMPERATURES SHOULD BE
ABLE TO COOL INTO THE LOW TO MID 40S. THE WARM FRONT LOOKS TO CROSS
INTO S WI AROUND 00Z THURSDAY...WITH SEVERAL DISTURBANCES EJECTING
NE INTO THE AREA TO KEEP CHANCE TO LIKELY POPS GOING THROUGH
THURSDAY. THE WARMEST DAY OVER THE W HALF /PENDING RAIN SHOWER/
LOOKS TO BE THURSDAY AS 850MB TEMPS RISE TO A CWA AVG OF 18C.
CURRENTLY FCSTING HIGHS IN THE MID TO UPPER 60S AS THE SFC LOW
TRACKS ACROSS S MN AND EXTENDING UP THROUGH W LAKE SUPERIOR. JUST
HOW FAR N THE WARM FRONT CAN PUSH ACROSS THE REGION WILL BE A
CONCERN TS WISE. AT THIS POINT IT LOOKS LIKE THE WARM FRONT MAY HOOK
UP THROUGH SW UPPER MI AND NEAR THE WI BORDER AT 12Z
THURSDAY...BEFORE THE SFC LOW AND ASSOCIATED COLD FRONT CATCH UP TO
IT AS THE LOW SHIFTS OVER E MN/NW WI AND THE W HALF OF UPPER MI BY
06Z FRIDAY. EXPECT THE LOW TO N OF LAKE SUPERIOR ACROSS ONTARIO BY
MID DAY FRIDAY...DRAGGING THE INITIAL COLD FRONT E OF UPPER MI. THE
SECONDARY FRONT MAY BRING SOME WRAP AROUND MOISTURE INTO THE W HALF
OF THE CWA FOR THE REMAINDER OF FRIDAY...AS WINDS BECOME MORE W-NW.
850MB TEMPS SHOULD FALL TO AROUND 2C BY SATURDAY MORNING AS PW
VALUES FALL TO AROUND 0.3IN...OR 45-60 PERCENT OF NORMAL. CURRENTLY
HAVE UPPER 30S FCST FOR THE W THIRD OF THE CWA...BUT WOULD NOT BE
SURPRISED IF IT ENDS UP BEING A BIT LOWER.
CONTINUED THE TREND OF LOWERING DEW POINTS ON SATURDAY...AS DRY HIGH
PRESSURE TEMPORARILY BUILDS ACROSS THE UPPER GREAT LAKES. THE NEXT
LOW /PICKED UP MUCH BETTER CONSISTENCY WISE OFF THE 12Z GFS AND
ECMWF/ LOOKS TO BE OVER S CANADA AND MN AT 12Z SUNDAY. LOOK FOR THE
RETURN OF RAIN SHOWERS. KEPT ANY MENTION OF TS TO THE SW AT THIS
TIME. PRECIP LOOKS TO CONTINUE INTO MONDAY...AS LOW PRESSURE LINGERS
ACROSS THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 107 AM EDT WED MAY 7 2014
ALTHOUGH SFC HIGH PRES RIDGE FROM NRN ONTARIO TO THE LWR LAKES WILL
DRIFT E...DRIER E TO SE NEAR SFC FLOW EMANATING FROM THE RIDGE
SHOULD WORK TO MAINTAIN VFR CONDITIONS AT KIWD/KCMX/KSAW THRU THIS
FCST PERIOD. GRADUAL INCREASE IN MOISTURE/INSTABILITY ABOVE THE
SHALLOW DRIER AIR WILL PROBABLY LEAD TO SOME SCT SHRA LIFTING INTO
UPPER MI AT TIMES DESPITE WARM FRONT WELL S OF THE AREA. AT THIS
POINT... THERE IS NOT MUCH CONFIDENCE IN PINNING DOWN BEST TIME
PERIODS FOR PCPN. BEST CHC MAY BE AT KIWD LATER IN THE NIGHT AND
THEN AGAIN THIS EVENING...SO VCSH WAS MENTIONED THERE. LLWS WAS
INCLUDED OVERNIGHT AT KIWD/KSAW (LATEST KMQT RADAR VAD WIND PROFILE
SHOWS SE WIND AROUND 30KT AT 500FT AGL).
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 AM EDT WED MAY 7 2014
LAKE SUPERIOR WILL INCREASINGLY COME UNDER THE INFLUENCE OF AN AREA
OF LOW PRESSURE CURRENTLY FORMING OVER WESTERN KANSAS OVER THE NEXT
TWO DAYS. EXPECT GENERAL EASTERLY FLOW OVER THE LAKE THROUGH
THURSDAY...WITH A TREND MORE TO THE NORTHEAST OVER WESTERN HALF AND
THE SOUTHEAST OVER THE EAST HALF. THIS FLOW WILL MAINLY PRODUCE
WINDS UP TO 25KTS DURING THAT TIMEFRAME...WITH A FEW HIGHER GUSTS
OVER FAR WESTERN LAKE SUPERIOR THROUGH TONIGHT WHERE THERE IS
FAVORABLE FUNNELLING. AS THE LOW LIFTS ACROSS WESTERN LAKE SUPERIOR
ON THURSDAY NIGHT AND EARLY FRIDAY MORNING...WINDS OVER THE EASTERN
2/3RD WILL SHIFT TO THE SOUTH AND REMAIN UP TO 25KTS. ALTHOUGH
THERE WILL BE STRONGER WINDS ALOFT...EXPECT THE MARINE LAYER TO
KEEP THE WINDS AT THE SURFACE LOWER. THE LOW WILL CONTINUE
NORTHEAST TO JAMES BAY ON FRIDAY AND DRAG A TRAILING COLD FRONT
ACROSS LAKE SUPERIOR ON FRIDAY...SHIFTING WINDS TO THE WEST. A HIGH
PRESSURE RIDGE WILL MOVE OVER THE LAKE ON FRIDAY NIGHT AND REMAIN
INTO SATURDAY...LEADING TO LIGHT WINDS.
&&
.HYDROLOGY...
ISSUED AT 309 PM EDT TUE MAY 6 2014
STREAMS AND RIVERS WILL CONTINUE TO EXPERIENCE HIGHER LEVELS.
LOCATIONS STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE
STURGEON RIVER IN HOUGHTON AND BARAGA COUNTIES AND THE TAHQUAMENON
RIVER NEAR PARADISE.
WHILE WET WEATHER WILL RETURN LATE TONIGHT THROUGH FRIDAY
EVENING...RAINFALL SHOULD AROUND A TENTH OF AN INCH OR LESS THROUGH
THE DAY WEDNESDAY. AT THE CURRENT TIME MOST OF THE RAIN LOOKS TO
FALL OVER THE STURGEON RIVER BASIN THURSDAY EVENING. ADDING TO THIS
WILL BE THE FEW INCHES OF SNOW WATER EQUIVALENT BEING SHOWN FROM
NOHRSC SET UP FROM THE TIP OF THE KEWEENAW PENINSULA THROUGH
PAINESDALE...DONKEN...AND WINONA. THIS LINES UP WELL WITH THE LATEST
SNOW DEPTHS REPORTED AT PAINESDALE AND HERMAN. WILL SEE HOW THIS
SNOW MELT /GIVEN WARMER FCST TEMPS FOR THE REST OF THE WEEK/ IMPACTS
DOWNSTREAM RIVERS INCLUDING THE STURGEON RIVER OF BARAGA/HOUGHTON
COUNTIES AND THE TRAP ROCK RIVER. MOST IF NOT ALL OF THE SNOW COULD
MELT BY THIS WEEKEND. FLOWS WILL LIKELY INCREASE OUT OF THE PRICKETT
DAM OVER THE NEXT DAY OR TWO...WHICH WILL LEAD TO CONTINUED HIGHER
LEVELS ON THE STURGEON RIVER IN HOUGHTON/BARAGA COUNTIES. WITH THE
ALREADY HIGH LEVELS...ALSM4/CLLM4 MAY REACH FLOOD STAGE.
BACK TO THE WET WEATHER EXPECTED THROUGH FRIDAY EVENING...SEVERAL
ROUNDS OF SHOWERS AND POTENTIALLY THUNDERSTORMS WILL AFFECT THE AREA
DURING THE SECOND HALF OF THE WORK WEEK. RAINFALL AMOUNTS WILL
LIKELY EXCEED A HALF OF AN INCH FOR MOST OF UPPER MICHIGAN...AND
LOCALIZED AMOUNTS OVER AN INCH SHOULD OCCUR WHERE THUNDERSTORMS
TRACK. THIS WILL KEEP THE RIVER LEVELS HIGH INTO NEXT WEEKEND. THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO
MONITOR RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...SRF
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
112 AM EDT WED MAY 7 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 322 PM EDT TUE MAY 6 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW BLDG UPR RDG/SFC
HI PRES OVER THE UPR LKS BTWN TROF IN FAR ERN CANADA AND A PAIR OF
CLOSED LOWS IN SPLIT FLOW ACRS THE W...ONE OVER ALBERTA AND THE
OTHER DIGGING INTO THE DESERT SW. 12Z GRB/APX/MPX RAOBS INDICATE A
DRY...STABLE AIRMASS IS IN PLACE...WITH PWAT AS LO AS 0.25 INCH AT
APX. BUT THERE ARE PLENTY OF MID/HI CLDS ASSOCIATED WITH WAD/
ISENTROPIC ASCENT IN THE SW FLOW ALF BTWN THE HI OVER THE UPR LKS
AND LOWER HGTS/MSLP TO THE W ASSOCIATED WITH THE WRN TROFFING. THERE
IS A BAND OF THICKER MID LVL CLDS MOVING ENEWD THRU NE MN/WRN LK SUP
AND TOWARD THE WRN LAND CWA ASSOCIATED WITH SHARPER ISENTROPIC ASCENT
BEST SHOWN ON THE 300-305K SFCS...OR ABOUT H6-7...WELL TO THE NE OF
DVLPG SFC-H85 WARM FNT IN THE CENTRAL PLAINS. BUT ADVECTION OF DRIER
AIR IN THE LLVLS WITH STEADY ESE WINDS ON THE WRN FLANK OF THE SFC HI
IS PREVENTING ANY PCPN FM REACHING THE GROUND E OF FAR WRN LK SUP.
MAIN FCST CONCERN IN THE SHORTER TERM FOCUS ON PCPN CHCS ASSOCIATED
WITH LARGER SCALE WAD/ISENTROPIC ASCENT TO THE NE OF WARM FNT NOW IN
THE CENTRAL PLAINS.
THIS AFTN/TNGT...ALTHOUGH HI CLDS WL SPILL OVER THE ENTIRE CWA THIS
AFTN...BAND OF THICKER MID CLDS IS FCST TO IMPACT MAINLY THE NW
PORTIONS OF THE CWA THIS AFTN BEFORE SHIFTING TO THE NE AFT SUNSET.
THE LLVLS SHOULD REMAIN SUFFICIENTLY DRY TO KEEP PCPN FM REACHING THE
SFC EVEN WHERE THE CLDS ARE THICKEST. THE PERIOD FM 00Z-06Z SHOULD BE
DRY DESPITE CONSIDERABLE HI CLDS. WITH AN INCRSG H85 SW LLJ/THETA E
ADVCTN/DEEP LYR QVECTOR CNVGC TNGT...MORE NMRS SHRA/TS ARE LIKELY TO
DVLP AHEAD OF THE WARM FNT MOVING SLOWLY TO THE NE TOWARD SRN MN/WI
BY 12Z. BUT SINCE THE SHARPER DEEP LYR QVECTOR CNVGC AND UPR DVGC ARE
FCST TO REMAIN S OF UPR MI CLOSER TO THE WARM FNT...CORFIDI VECTORS
FCST TO BE WNW IN WI TO THE N OF THE H85 WARM FNT WHICH WOULD RESULT
IN MOST NMRS SHRA/TS REMAINING TO THE S AND ROBBING MSTR FOR PCPN
FARTHER N...AND DRY AIR IS FCST TO LINGER IN THE SFC-H7 LYR WITHIN
PERSISTENT ESE LLVL TRAJECTORIES...SUSPECT THE 12Z GFS IS TOO
AGGRESSIVE TO LIFT PCPN INTO MUCH OF UPR MI BY 12Z WED. WL TREND THE
FCST CLOSER TO THE DRIER 12Z NAM/REGIONAL CNDN MODELS. THIS GUIDANCE
RESTRICTS QPF TO AREAS NEAR THE WI BORDER AND BAND OF SHARPER H85
FGEN. WL FCST HIER CHC POPS OVER SRN MENOMINEE COUNTY BUT GO WITH A
DRY FCST FOR THE NE CWA.
WED...SFC WARM FNT NEAR THE SRN MN/WI BORDER AND H85 WARM FNT INTO
CENTRAL WI IS FCST TO REMAIN NEARLY STNRY THRU 00Z THU WELL TO THE NE
OF DEEP TROF LINGERING IN THE DESERT SW. WELL TO THE NE OF THIS MAIN
FORCING MECHANISM...12Z MODELS INDICATE DEEP LYR QVECTOR DVGC/SOME
UPR CNVGC WL DOMINATE THRU MUCH OF THE AFTN UNDER INCRSGLY AMPLIFIED
UPR RDG/HGT RISES TO THE N OF THE WARM FNT AND DIMINISHING DEEP LYR
QVECTOR CNVGC THAT WL SUPPORT THE MAIN AREA OF SHRA/TS TO THE S AND
SHIFT MAINLY TO THE E INTO THE LOWER LKS PARALLEL TO THE WARM FNT. SO
SUSPECT THE MORE NMRS SHRA WL EXIT THE FAR SCENTRAL EARLY IN THE DAY
AND LEAVE JUST ISOLD-SCT SHRA NEAR THE WI BORDER MOST OF THE DAY.
INCLUDED MENTION OF SOME ELEVATED TS OVER THE FAR SCENTRAL LATER IN
THE DAY TO ACCOUNT FOR AREA OF FCST LOWER SSI SHOWN BY THE MORE
STABLE GFS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 441 PM EDT TUE MAY 6 2014
WHEN...WHERE...AND HOW MUCH PRECIPITATION WILL FALL ALONG WITH THE
THUNDERSTORM POTENTIAL WILL BE THE MAIN CONCERNS IN THIS LONG TERM
PERIOD. THE SLIGHT RISK TS POTENTIAL FROM SPC IS ALONG THE WI BORDER
FOR THE WEDNESDAY NIGHT PERIOD. ANOTHER CONCERN WITH THE WARMER AIR
WILL BE FOG...WHICH IS STILL FCST TUESDAY NIGHT THROUGH
FRIDAY...PARTICULARLY ACROSS LAKE SUPERIOR AND LAKE MI.
THE 500MB LOW CURRENTLY ALONG THE ALBERTA AND SASKATCHEWAN BORDER
AND TROUGH EXTENDING ACROSS NV AND S CA THIS AFTERNOON WILL EVER SO
SLOWLY PROGRESS E...STRETCHING FROM SASKATCHEWAN THROUGH THE
4-CORNERS REGION BY 06Z THURSDAY...AS THE HIGH AMPLITUDE RIDGE
CONTINUES TO BUILD ACROSS THE UPPER GREAT LAKES /WITH THE APEX OVER
MAINLY CENTRAL AND E UPPER MI/.
WENT WITH HIGH CHANCE TO LIKELY POPS FOR THE W HALF OF UPPER MI
WEDNESDAY NIGHT...SO DESPITE THE SE WINDS...TEMPERATURES SHOULD BE
ABLE TO COOL INTO THE LOW TO MID 40S. THE WARM FRONT LOOKS TO CROSS
INTO S WI AROUND 00Z THURSDAY...WITH SEVERAL DISTURBANCES EJECTING
NE INTO THE AREA TO KEEP CHANCE TO LIKELY POPS GOING THROUGH
THURSDAY. THE WARMEST DAY OVER THE W HALF /PENDING RAIN SHOWER/
LOOKS TO BE THURSDAY AS 850MB TEMPS RISE TO A CWA AVG OF 18C.
CURRENTLY FCSTING HIGHS IN THE MID TO UPPER 60S AS THE SFC LOW
TRACKS ACROSS S MN AND EXTENDING UP THROUGH W LAKE SUPERIOR. JUST
HOW FAR N THE WARM FRONT CAN PUSH ACROSS THE REGION WILL BE A
CONCERN TS WISE. AT THIS POINT IT LOOKS LIKE THE WARM FRONT MAY HOOK
UP THROUGH SW UPPER MI AND NEAR THE WI BORDER AT 12Z
THURSDAY...BEFORE THE SFC LOW AND ASSOCIATED COLD FRONT CATCH UP TO
IT AS THE LOW SHIFTS OVER E MN/NW WI AND THE W HALF OF UPPER MI BY
06Z FRIDAY. EXPECT THE LOW TO N OF LAKE SUPERIOR ACROSS ONTARIO BY
MID DAY FRIDAY...DRAGGING THE INITIAL COLD FRONT E OF UPPER MI. THE
SECONDARY FRONT MAY BRING SOME WRAP AROUND MOISTURE INTO THE W HALF
OF THE CWA FOR THE REMAINDER OF FRIDAY...AS WINDS BECOME MORE W-NW.
850MB TEMPS SHOULD FALL TO AROUND 2C BY SATURDAY MORNING AS PW
VALUES FALL TO AROUND 0.3IN...OR 45-60 PERCENT OF NORMAL. CURRENTLY
HAVE UPPER 30S FCST FOR THE W THIRD OF THE CWA...BUT WOULD NOT BE
SURPRISED IF IT ENDS UP BEING A BIT LOWER.
CONTINUED THE TREND OF LOWERING DEW POINTS ON SATURDAY...AS DRY HIGH
PRESSURE TEMPORARILY BUILDS ACROSS THE UPPER GREAT LAKES. THE NEXT
LOW /PICKED UP MUCH BETTER CONSISTENCY WISE OFF THE 12Z GFS AND
ECMWF/ LOOKS TO BE OVER S CANADA AND MN AT 12Z SUNDAY. LOOK FOR THE
RETURN OF RAIN SHOWERS. KEPT ANY MENTION OF TS TO THE SW AT THIS
TIME. PRECIP LOOKS TO CONTINUE INTO MONDAY...AS LOW PRESSURE LINGERS
ACROSS THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 107 AM EDT WED MAY 7 2014
ALTHOUGH SFC HIGH PRES RIDGE FROM NRN ONTARIO TO THE LWR LAKES WILL
DRIFT E...DRIER E TO SE NEAR SFC FLOW EMANATING FROM THE RIDGE
SHOULD WORK TO MAINTAIN VFR CONDITIONS AT KIWD/KCMX/KSAW THRU THIS
FCST PERIOD. GRADUAL INCREASE IN MOISTURE/INSTABILITY ABOVE THE
SHALLOW DRIER AIR WILL PROBABLY LEAD TO SOME SCT SHRA LIFTING INTO
UPPER MI AT TIMES DESPITE WARM FRONT WELL S OF THE AREA. AT THIS
POINT... THERE IS NOT MUCH CONFIDENCE IN PINNING DOWN BEST TIME
PERIODS FOR PCPN. BEST CHC MAY BE AT KIWD LATER IN THE NIGHT AND
THEN AGAIN THIS EVENING...SO VCSH WAS MENTIONED THERE. LLWS WAS
INCLUDED OVERNIGHT AT KIWD/KSAW (LATEST KMQT RADAR VAD WIND PROFILE
SHOWS SE WIND AROUND 30KT AT 500FT AGL).
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 322 PM EDT TUE MAY 6 2014
AS THE PRES GRADIENT TIGHTENS OVER LAKE SUPERIOR ON THE SW FLANK OF
HI PRES RETREATING THRU ONTARIO AND IN ADVANCE OF LO PRES/ATTENDANT
WARM FRONT LIFTING NE FROM THE PLAINS...EXPECT SLOWLY VEERING NE TO
SE WINDS UP TO 15-25 KTS TO DOMINATE INTO THU. AS HIGHER DEW POINTS
ARRIVE ON WED NIGHT/THU...FOG WILL DEVELOP OVER THE COLDER/ICE
COVERED LAKE WATERS. WINDS WILL THEN VEER FROM THE SE TO THE W ON
THU NIGHT THRU SAT AS THE LOW PRES TRACKS OVER FAR WESTERN LAKE
SUPERIOR AND INTO NW ONTARIO. THE ARRIVAL OF DRIER AIR IN THE WAKE
OF THIS LOW WILL CAUSE THE FOG TO DISSIPATE FRI NIGHT. WINDS WILL
THEN SHIFT TO THE E ON SUN AS THE HI PRES TRAILING THE DEPARTING LO
MOVES TO THE E. NO GALES SEEN IN THIS FORECAST PERIOD.
&&
.HYDROLOGY...
ISSUED AT 309 PM EDT TUE MAY 6 2014
STREAMS AND RIVERS WILL CONTINUE TO EXPERIENCE HIGHER LEVELS.
LOCATIONS STILL NEAR OR ABOVE BANKFULL AT THIS TIME INCLUDE THE
STURGEON RIVER IN HOUGHTON AND BARAGA COUNTIES AND THE TAHQUAMENON
RIVER NEAR PARADISE.
WHILE WET WEATHER WILL RETURN LATE TONIGHT THROUGH FRIDAY
EVENING...RAINFALL SHOULD AROUND A TENTH OF AN INCH OR LESS THROUGH
THE DAY WEDNESDAY. AT THE CURRENT TIME MOST OF THE RAIN LOOKS TO
FALL OVER THE STURGEON RIVER BASIN THURSDAY EVENING. ADDING TO THIS
WILL BE THE FEW INCHES OF SNOW WATER EQUIVALENT BEING SHOWN FROM
NOHRSC SET UP FROM THE TIP OF THE KEWEENAW PENINSULA THROUGH
PAINESDALE...DONKEN...AND WINONA. THIS LINES UP WELL WITH THE LATEST
SNOW DEPTHS REPORTED AT PAINESDALE AND HERMAN. WILL SEE HOW THIS
SNOW MELT /GIVEN WARMER FCST TEMPS FOR THE REST OF THE WEEK/ IMPACTS
DOWNSTREAM RIVERS INCLUDING THE STURGEON RIVER OF BARAGA/HOUGHTON
COUNTIES AND THE TRAP ROCK RIVER. MOST IF NOT ALL OF THE SNOW COULD
MELT BY THIS WEEKEND. FLOWS WILL LIKELY INCREASE OUT OF THE PRICKETT
DAM OVER THE NEXT DAY OR TWO...WHICH WILL LEAD TO CONTINUED HIGHER
LEVELS ON THE STURGEON RIVER IN HOUGHTON/BARAGA COUNTIES. WITH THE
ALREADY HIGH LEVELS...ALSM4/CLLM4 MAY REACH FLOOD STAGE.
BACK TO THE WET WEATHER EXPECTED THROUGH FRIDAY EVENING...SEVERAL
ROUNDS OF SHOWERS AND POTENTIALLY THUNDERSTORMS WILL AFFECT THE AREA
DURING THE SECOND HALF OF THE WORK WEEK. RAINFALL AMOUNTS WILL
LIKELY EXCEED A HALF OF AN INCH FOR MOST OF UPPER MICHIGAN...AND
LOCALIZED AMOUNTS OVER AN INCH SHOULD OCCUR WHERE THUNDERSTORMS
TRACK. THIS WILL KEEP THE RIVER LEVELS HIGH INTO NEXT WEEKEND. THOSE
LIVING AROUND RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO
MONITOR RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KC
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
146 PM CDT WED MAY 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 434 AM CDT WED MAY 7 2014
SURFACE WARM FRONT THIS MORNING WAS JUST CROSSING THE BORDER FROM MO
INTO IA AND IS ASSOCIATED WITH A 995 MB SFC LOW IN THE VICINITY OF
CO/KS/NEB. THERE ARE A COUPLE OF BANDS OF STORMS OUT THERE THIS
MORNING. ONE EXTENDS FROM CLEVELAND BACK TO GREEN BAY THAT YOU CAN
FOLLOW BACK TO SHOWERS IN THE DULUTH AREA AND ASSOCIATED WITH THE
ARRIVAL OF THE ELEVATED CAPE. AT THE NOSE OF THE LLJ AND EDGE OF THE
CAPPING INVERSION /WHERE H7 TEMPS EXCEED +9C/ YOU WILL FIND A BROKEN
LINE OF STORMS ALONG THE MN/IA. MPXWRF AND SPCWRF PRETTY MUCH NAILED
THESE STORMS...SO FOLLOWED THE TREND OF THESE MODELS FOR WORKING
HIGHER POPS SOUTH OF A MANKATO/RED WING/CHIP FALLS LINE THROUGH THE
MORNING. GIVEN THE RAPS DEPICTION OF THE LLJ VEERING MORE EASTERLY
THROUGH THE MORNING WITH LITTLE DEVELOPMENT NORTH...IT MAKES SENSE
THAT THESE STORMS WILL NOT BUILD MUCH FARTHER NORTH OF THEIR CURRENT
LATITUDE AND WILL INSTEAD HEAD MORE OR LESS DOWN I-90 INTO CENTRAL
WI WITH THE LLJ. NOT EXPECTING MUCH SEVERE POTENTIAL OUT OF
THESE...BUT WITH EFFECTIVE SHEAR UP NEAR 30 KTS AND CAPE BETWEEN
-10C AND -30C /HAIL CAPE/ UP AROUND 500 J/KG...WE WILL LIKELY
CONTINUE TO SEE THE OCCASIONAL STORM PUT OUT HAIL THAT GETS UP IN
THE 1 INCH TERRITORY OR SLIGHTLY LARGER.
BEHIND THIS MORNING ACTIVITY...H7 TEMPS WILL PUSH UP TO BETWEEN 8
AND 10C...WITH A VERY DRY PLUME OF AIR COMING IN IN THE H7-H5 LEVEL
AS WELL. THIS WILL LIKELY KEEP THE MPX AREA CAPPED AND DRY MUCH OF
THE DAY AS WE WATCH THE WARM FRONT LIFT NORTH ACROSS IOWA. BY PEAK
HEATING...THIS WARM FRONT LOOKS TO BE UP NEAR I-90. WARM SECTOR
COMING UP WITH THIS FRONT IS THE SAME AIRMASS THAT HAS SPENT THE
LAST THREE DAYS BREAKING RECORD HIGHS ACROSS TX/OK/KS...SO IT WILL
BE WARM TO SAY THE LEAST...WITH HIGHS IN THE 90S LIKELY CLEAR UP TO
THE I-80 CORRIDOR. THIS WARM FRONT STILL MAKES FOR A DIFFICULT
FORECAST AS OVERCAST CONDITIONS TO THE NORTH OF THE FRONT WILL HOLD
HIGHS BACK IN THE 50S/60S...WHILE SOUTH OF THE BOUNDARY IT WILL BE
FEELING LIKE SUMMER. CONTINUED TO FAVOR THIS FORECAST TOWARD THE
ECMWF...WHICH HAS MID 80S ALONG I-90 THAT FALL BACK TO THE UPPER
50S/LOWER 60S NORTH OF I-94. WE WILL HAVE TO WATCH THOSE TEMPS
THOUGH. THERE IS VIRTUALLY NO CLOUD COVER ACROSS IOWA RIGHT
NOW...AND IF THIS TREND CONTINUES OVER US THIS AFTERNOON...THEN
SOMETHING MUCH CLOSER TO WHAT THE RAP HAS BEEN SHOWING ALL MORNING
IS POSSIBLE...WHICH IS LOWER 90S COMING UP AS FAR NORTH AS
MANKATO/REDWOOD FALLS...WITH HIGHS CLOSER TO 80 IN THE CITIES...WITH
EVEN THE COLDER AREAS AROUND LADYSMITH PUSHING 70.
MAIN QUESTION FOR THIS EVENING/TONIGHT IS WHEN DOES THE CAP BREAK.
ONCE IT DOES...IT IS LOOKING LIKE A VERY ACTIVE NIGHT ACROSS THE MPX
CWA. THROUGH THE AFTERNOON...ANY ACTIVITY LOOKS TO REMAIN TO THE NW
OF THE CAP...WHICH WOULD KEEP THE BULK OF THE ACTIVITY TODAY OUT
FROM CENTRAL SODAK INTO NW MN. EVENTUALLY...A STRENGTHENING LLJ AND
THE APPROACH OF THE MAIN UPPER TROUGH WILL START TO ERODE THE CAP.
GENERALLY FOLLOWED THE IDEA OF THE SPCWRF AND THE NMM/ARW WITH
ACTIVITY TAKING OFF BETWEEN 2Z AND 4Z. GIVEN THE DEGREE OF
INSTABILITY EXPECTED AND EFFECTIVE SHEARS UP AROUND 50 KTS...IT IS
VERY LIKELY THAT THESE STORMS WILL BE ABLE TO PRODUCE LARGE
HAIL...SO THE DAY1 SLIGHT RISK IS MORE THAN WARRANTED. ALTHOUGH NO
CONVECTION IS CURRENTLY ANTICIPATED IN THE AFTERNOON...IF WE WERE TO
SEE SOMETHING GO IT WOULD HAVE A HIGH LIKELIHOOD OF BEING
SEVERE...WITH A TORNADO THREAT IF IT IS CLOSE TO THE WARM FRONT.
HOWEVER...THE WARM/DRY LAYER NOTED EARLIER AROUND H7 WILL MOST
LIKELY KEEP ANYTHING FROM GOING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 434 AM CDT WED MAY 7 2014
THE EXTENDED PERIOD WILL BE AN ACTIVE ONE WITH ONLY ONE DRY PERIOD
FORECAST AND THAT IS FRIDAY NIGHT. THURSDAY IS THE DAY OF
INTEREST. ALL INDICATIONS ARE FOR LOW PRESSURE OVER EASTERN
NEBRASKA THURSDAY MORNING TO SLOWLY DEEPEN WHILE MOVING INTO
SOUTHWEST MINNESOTA DURING THE AFTERNOON AND INTO CENTRAL
MINNESOTA DURING THE EVENING. CONVECTION IS ANTICIPATED TO BE
ONGOING THURSDAY MORNING ACROSS CENTRAL MN AND WEST CENTRAL WI.
THIS WILL MOVE NORTHEAST EARLY ON ALLOWING FOR THE DESTABILIZATION
TO COMMENCE. PROJECTIONS FOR THE AFTERNOON AND EVENING HOURS ARE
FOR 0-1KM SHEAR TO BE IN THE 25-35 KNOT RANGE AHEAD OF THE LOW AND
COLD FRONT WITH 0-6KM SHEAR IN THE 40-50 KNOT RANGE. EASTERN MN
AND WESTERN WI ARE ALSO IN A FAVORABLE COUPLED JET ALOFT WITH 100
KNOT RIGHT ENTRANCE REGION OVER NORTHERN MN WHILE A 100+ KNOT JET
SURGES INTO EASTERN IA DURING THE AFTERNOON. THE DIFFERENTIAL
DIVERGENCE IS QUITE STRONG BY EVENING ACROSS THE TWIN CITIES.
ALSO...VARIOUS SOLUTIONS ARE POINTING TO 0-3KM CAPE REACHING
100-150 J/KG BY LATE IN THE AFTERNOON...AGAIN CLOSE TO THE TWIN
CITIES. HENCE...A SEVERE AFTERNOON AND EVENING IS LOOKING MORE AND
MORE LIKELY WITH ALL FORMS OF SEVERE WEATHER POSSIBLE INCLUDING A
FEW TORNADOES. THE SEVERE THREAT SHOULD BE OVER BY MIDNIGHT ACROSS
WESTERN WI AS THE ATTENDANT COLD FRONT MOVES THROUGH. HIGHS ON
THURSDAY HAVE POTENTIAL TO RUN INTO THE 80S FROM THE TWIN CITIES
ON SOUTH AND SOUTHWEST. BLENDED GUIDANCE KEPT HIGHS IN THE UPPER
70S.
A FEW SHOWERS MAY LINGER OVER NORTHERN AND EASTERN AREAS OF THE FA
ON FRIDAY UNDER THE COLD UPPER TROUGH. AS MENTIONED EARLIER...FRIDAY
NIGHT IS THE ONLY DRY PERIOD AS A WEAK RIDGE OF HIGH PRESSURE
MOVES THROUGH. THE PATTERN STARTS TO BECOME MORE ACTIVE AGAIN ON
SATURDAY AS NORTHERN AND SOUTHERN STREAM ENERGY BEGIN TO
INFLUENCE THE WESTERN HALF OF THE CONUS. THIS DEVELOPS ANOTHER
WAVE OF LOW PRESSURE TO OUR SOUTHWEST WITH SHOWER CHANCES
INCREASING THROUGH THE WEEKEND AND EARLY NEXT WEEK. SOME
SIGNIFICANT DIFFERENCES EXIST BETWEEN THE GFS AND EC BY EARLY NEXT
WEEK ON THE LOCATION OF THE SURFACE LOW. THE GFS WOULD BE FLATTER
AND FURTHER EAST WITH THE LOW WHILE THE EC IS MORE ROBUST WITH
THE UPPER TROUGH AND SURFACE LOW. THIS WILL NEED TO BE WATCHED AS
WE COULD BE CLOSE TO THE WARM SECTOR ALONG WITH A SEVERE WEATHER
THREAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1257 PM CDT WED MAY 7 2014
AT LEAST A COUPLE ROUNDS OF THUNDERSTORMS ARE EXPECTED OVER THE
NEXT 24 HOURS. THE FIRST ROUND ARRIVES THIS EVENING AND SHOULD
MAINLY AFFECT EASTERN MN AND WESTERN WI BETWEEN 01Z-06Z. THE MAIN
THREAT WITH THE STORMS TONIGHT WILL BE LARGE. THE SECOND ROUND OF
STORMS IS EXPECTED LATE IN THE MORING IN WESTERN MN AND DURING THE
AFTERNOON IN EASTERN MN AND WESTERN WI. MVFR CEILINGS HAVE BEEN
SLOW TO ADVANCE NORTH TODAY...AND IT ACTUALLY LOOKS LIKE THAT MOST
OF THE 2000-3000FT CEILINGS WILL STAY IN FAR WESTERN MN.
KMSP...
NO AVIATION WEATHER CONCERNS FOR THE REMAINDER OF THE DAYLIGHT
HOURS /INCLUDING THE EVENING PUSH/. WE EXPECTED THUNDERSTORMS IN
EASTERN MN LATE THIS EVENING...BUT MOST OF THE ACTIVITY WILL OCCUR
BETWEEN 02-04Z...WITH THE PRIMARY THREAT BEING LARGE HAIL. WE ARE
MUCH LESS CONFIDENT IN HOW MUCH ACTIVITY WILL PERSIST OVERNIGHT
AND INTO THE THURSDAY MORNING COMMUTE. MOST OF THE ACTIVITY SHOULD
FOCUS ITSELF NORTH OF THE AIRPORT. THE SECOND ROUND HAS A BETTER
CHANCE AT PRODUCING SEVERE WEATHER TOMORROW AFTERNOON.
/OUTLOOK FOR KMSP/
THU NIGHT...MVFR CONDITIONS POSSIBLE WITH SHOWERS AND
THUNDERSTORMS. WINDS S BECOMING W AT 10G20KTS.
FRI...MVFR EARLY...THEN VFR. WINDS W AT 10G20KTS.
SAT...VFR. WINDS S 5-10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...CLF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
703 AM CDT WED MAY 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 434 AM CDT WED MAY 7 2014
SURFACE WARM FRONT THIS MORNING WAS JUST CROSSING THE BORDER FROM MO
INTO IA AND IS ASSOCIATED WITH A 995 MB SFC LOW IN THE VICINITY OF
CO/KS/NEB. THERE ARE A COUPLE OF BANDS OF STORMS OUT THERE THIS
MORNING. ONE EXTENDS FROM CLEVELAND BACK TO GREEN BAY THAT YOU CAN
FOLLOW BACK TO SHOWERS IN THE DULUTH AREA AND ASSOCIATED WITH THE
ARRIVAL OF THE ELEVATED CAPE. AT THE NOSE OF THE LLJ AND EDGE OF THE
CAPPING INVERSION /WHERE H7 TEMPS EXCEED +9C/ YOU WILL FIND A BROKEN
LINE OF STORMS ALONG THE MN/IA. MPXWRF AND SPCWRF PRETTY MUCH NAILED
THESE STORMS...SO FOLLOWED THE TREND OF THESE MODELS FOR WORKING
HIGHER POPS SOUTH OF A MANKATO/RED WING/CHIP FALLS LINE THROUGH THE
MORNING. GIVEN THE RAPS DEPICTION OF THE LLJ VEERING MORE EASTERLY
THROUGH THE MORNING WITH LITTLE DEVELOPMENT NORTH...IT MAKES SENSE
THAT THESE STORMS WILL NOT BUILD MUCH FARTHER NORTH OF THEIR CURRENT
LATITUDE AND WILL INSTEAD HEAD MORE OR LESS DOWN I-90 INTO CENTRAL
WI WITH THE LLJ. NOT EXPECTING MUCH SEVERE POTENTIAL OUT OF
THESE...BUT WITH EFFECTIVE SHEAR UP NEAR 30 KTS AND CAPE BETWEEN
-10C AND -30C /HAIL CAPE/ UP AROUND 500 J/KG...WE WILL LIKELY
CONTINUE TO SEE THE OCCASIONAL STORM PUT OUT HAIL THAT GETS UP IN
THE 1 INCH TERRITORY OR SLIGHTLY LARGER.
BEHIND THIS MORNING ACTIVITY...H7 TEMPS WILL PUSH UP TO BETWEEN 8
AND 10C...WITH A VERY DRY PLUME OF AIR COMING IN IN THE H7-H5 LEVEL
AS WELL. THIS WILL LIKELY KEEP THE MPX AREA CAPPED AND DRY MUCH OF
THE DAY AS WE WATCH THE WARM FRONT LIFT NORTH ACROSS IOWA. BY PEAK
HEATING...THIS WARM FRONT LOOKS TO BE UP NEAR I-90. WARM SECTOR
COMING UP WITH THIS FRONT IS THE SAME AIRMASS THAT HAS SPENT THE
LAST THREE DAYS BREAKING RECORD HIGHS ACROSS TX/OK/KS...SO IT WILL
BE WARM TO SAY THE LEAST...WITH HIGHS IN THE 90S LIKELY CLEAR UP TO
THE I-80 CORRIDOR. THIS WARM FRONT STILL MAKES FOR A DIFFICULT
FORECAST AS OVERCAST CONDITIONS TO THE NORTH OF THE FRONT WILL HOLD
HIGHS BACK IN THE 50S/60S...WHILE SOUTH OF THE BOUNDARY IT WILL BE
FEELING LIKE SUMMER. CONTINUED TO FAVOR THIS FORECAST TOWARD THE
ECMWF...WHICH HAS MID 80S ALONG I-90 THAT FALL BACK TO THE UPPER
50S/LOWER 60S NORTH OF I-94. WE WILL HAVE TO WATCH THOSE TEMPS
THOUGH. THERE IS VIRTUALLY NO CLOUD COVER ACROSS IOWA RIGHT
NOW...AND IF THIS TREND CONTINUES OVER US THIS AFTERNOON...THEN
SOMETHING MUCH CLOSER TO WHAT THE RAP HAS BEEN SHOWING ALL MORNING
IS POSSIBLE...WHICH IS LOWER 90S COMING UP AS FAR NORTH AS
MANKATO/REDWOOD FALLS...WITH HIGHS CLOSER TO 80 IN THE CITIES...WITH
EVEN THE COLDER AREAS AROUND LADYSMITH PUSHING 70.
MAIN QUESTION FOR THIS EVENING/TONIGHT IS WHEN DOES THE CAP BREAK.
ONCE IT DOES...IT IS LOOKING LIKE A VERY ACTIVE NIGHT ACROSS THE MPX
CWA. THROUGH THE AFTERNOON...ANY ACTIVITY LOOKS TO REMAIN TO THE NW
OF THE CAP...WHICH WOULD KEEP THE BULK OF THE ACTIVITY TODAY OUT
FROM CENTRAL SODAK INTO NW MN. EVENTUALLY...A STRENGTHENING LLJ AND
THE APPROACH OF THE MAIN UPPER TROUGH WILL START TO ERODE THE CAP.
GENERALLY FOLLOWED THE IDEA OF THE SPCWRF AND THE NMM/ARW WITH
ACTIVITY TAKING OFF BETWEEN 2Z AND 4Z. GIVEN THE DEGREE OF
INSTABILITY EXPECTED AND EFFECTIVE SHEARS UP AROUND 50 KTS...IT IS
VERY LIKELY THAT THESE STORMS WILL BE ABLE TO PRODUCE LARGE
HAIL...SO THE DAY1 SLIGHT RISK IS MORE THAN WARRANTED. ALTHOUGH NO
CONVECTION IS CURRENTLY ANTICIPATED IN THE AFTERNOON...IF WE WERE TO
SEE SOMETHING GO IT WOULD HAVE A HIGH LIKELIHOOD OF BEING
SEVERE...WITH A TORNADO THREAT IF IT IS CLOSE TO THE WARM FRONT.
HOWEVER...THE WARM/DRY LAYER NOTED EARLIER AROUND H7 WILL MOST
LIKELY KEEP ANYTHING FROM GOING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 434 AM CDT WED MAY 7 2014
THE EXTENDED PERIOD WILL BE AN ACTIVE ONE WITH ONLY ONE DRY PERIOD
FORECAST AND THAT IS FRIDAY NIGHT. THURSDAY IS THE DAY OF
INTEREST. ALL INDICATIONS ARE FOR LOW PRESSURE OVER EASTERN
NEBRASKA THURSDAY MORNING TO SLOWLY DEEPEN WHILE MOVING INTO
SOUTHWEST MINNESOTA DURING THE AFTERNOON AND INTO CENTRAL
MINNESOTA DURING THE EVENING. CONVECTION IS ANTICIPATED TO BE
ONGOING THURSDAY MORNING ACROSS CENTRAL MN AND WEST CENTRAL WI.
THIS WILL MOVE NORTHEAST EARLY ON ALLOWING FOR THE DESTABILIZATION
TO COMMENCE. PROJECTIONS FOR THE AFTERNOON AND EVENING HOURS ARE
FOR 0-1KM SHEAR TO BE IN THE 25-35 KNOT RANGE AHEAD OF THE LOW AND
COLD FRONT WITH 0-6KM SHEAR IN THE 40-50 KNOT RANGE. EASTERN MN
AND WESTERN WI ARE ALSO IN A FAVORABLE COUPLED JET ALOFT WITH 100
KNOT RIGHT ENTRANCE REGION OVER NORTHERN MN WHILE A 100+ KNOT JET
SURGES INTO EASTERN IA DURING THE AFTERNOON. THE DIFFERENTIAL
DIVERGENCE IS QUITE STRONG BY EVENING ACROSS THE TWIN CITIES.
ALSO...VARIOUS SOLUTIONS ARE POINTING TO 0-3KM CAPE REACHING
100-150 J/KG BY LATE IN THE AFTERNOON...AGAIN CLOSE TO THE TWIN
CITIES. HENCE...A SEVERE AFTERNOON AND EVENING IS LOOKING MORE AND
MORE LIKELY WITH ALL FORMS OF SEVERE WEATHER POSSIBLE INCLUDING A
FEW TORNADOES. THE SEVERE THREAT SHOULD BE OVER BY MIDNIGHT ACROSS
WESTERN WI AS THE ATTENDANT COLD FRONT MOVES THROUGH. HIGHS ON
THURSDAY HAVE POTENTIAL TO RUN INTO THE 80S FROM THE TWIN CITIES
ON SOUTH AND SOUTHWEST. BLENDED GUIDANCE KEPT HIGHS IN THE UPPER
70S.
A FEW SHOWERS MAY LINGER OVER NORTHERN AND EASTERN AREAS OF THE FA
ON FRIDAY UNDER THE COLD UPPER TROUGH. AS MENTIONED EARLIER...FRIDAY
NIGHT IS THE ONLY DRY PERIOD AS A WEAK RIDGE OF HIGH PRESSURE
MOVES THROUGH. THE PATTERN STARTS TO BECOME MORE ACTIVE AGAIN ON
SATURDAY AS NORTHERN AND SOUTHERN STREAM ENERGY BEGIN TO
INFLUENCE THE WESTERN HALF OF THE CONUS. THIS DEVELOPS ANOTHER
WAVE OF LOW PRESSURE TO OUR SOUTHWEST WITH SHOWER CHANCES
INCREASING THROUGH THE WEEKEND AND EARLY NEXT WEEK. SOME
SIGNIFICANT DIFFERENCES EXIST BETWEEN THE GFS AND EC BY EARLY NEXT
WEEK ON THE LOCATION OF THE SURFACE LOW. THE GFS WOULD BE FLATTER
AND FURTHER EAST WITH THE LOW WHILE THE EC IS MORE ROBUST WITH
THE UPPER TROUGH AND SURFACE LOW. THIS WILL NEED TO BE WATCHED AS
WE COULD BE CLOSE TO THE WARM SECTOR ALONG WITH A SEVERE WEATHER
THREAT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 649 AM CDT WED MAY 7 2014
BIGGEST THING TO SAY FIRST IS THE GFSLAMP WAS IGNORED IN TERMS OF
ITS CIG FORECAST. THE WARM FRONT IS MAKING ITS WAY NORTH ACROSS
IOWA...HOWEVER THERE ARE VIRTUALLY NO CLOUDS BELOW 12K FEET IN
IOWA...SO FIND IT HARD TO BELIEVE THE VERY PESSIMISTIC LAMP
FORECASTS. INSTEAD CONTINUED TO FOLLOW THE IDEA OF THE NAM...WITH
CIGS NOT REALLY LOWERING MUCH UNTIL A LOCATION GETS CLOSER TO THE
WARM FRONT. AND EVEN THEN...THE HRRR/RAP SAY WE WILL NOT SEE MUCH
IN THE WAY OF STRATUS ANYWAYS...SO CONTINUED THE TREND OF BACKING
OFF ON THE MVFR MENTION. HI-RES MODELS CONTINUE TO SHOW TSRA
DEVELOPING IN THE VCNTY OF RWF BETWEEN 00Z AND 03Z...THEN RAPIDLY
EXPANDING ACROSS THE AREA AFTER 3Z AS THE WARM FRONT LIFTS NORTH.
COULD BE SEVERAL HOURS OF SHRA/TSRA ACTIVITY FOR STC/AXN ONCE
THINGS GO. THIS IS ALSO THE PERIOD WHEN LOWER CIGS WOULD BE MOST
LIKELY...BUT EVEN THEN WE MAY STAY PREDOMINATELY VFR.
KMSP...STORMS WILL STAY WELL SOUTH OF THE FIELD THIS MORNING...AND
ATMOSPHERE WILL REMAIN CAPPED TO KEEP THE FIELD DRY UNTIL LIKELY
BETWEEN 2Z AND 4Z. CONFIDENCE HIGH IN TSRA IMPACTING THE FIELD
TONIGHT...BUT A BIT LOWER ON EXACT TIMING. DO FEEL WARM FRONT WILL
HAVE LIFTED FAR ENOUGH THOUGH BY 12Z THU THAT MSP SHOULD BE DONE
WITH THE OVERNIGHT ACTIVITY BY THEN. AS FOR CIGS...BEGINNING TO
LOSE CONFIDENCE THAT WE WILL SEE MUCH IN THE WAY OF RESTRICTIONS AT
ALL OUTSIDE OF PRECIP...SO CONTINUED TO TREND TOWARD KEEPING CIGS
HIGHER.
/OUTLOOK FOR KMSP/
THU...VFR EARLY WITH IFR/TSRA LIKELY IN THE AFTERNOON. SOME STORMS
MAY BE SEVERE. WINDS SE BECOMING S AT 10G20KTS.
FRI...MVFR EARLY...THEN VFR. WINDS W AT 10G20KTS.
SAT...VFR. WINDS S 5-10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
434 AM CDT WED MAY 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 434 AM CDT WED MAY 7 2014
SURFACE WARM FRONT THIS MORNING WAS JUST CROSSING THE BORDER FROM MO
INTO IA AND IS ASSOCIATED WITH A 995 MB SFC LOW IN THE VICINITY OF
CO/KS/NEB. THERE ARE A COUPLE OF BANDS OF STORMS OUT THERE THIS
MORNING. ONE EXTENDS FROM CLEVELAND BACK TO GREEN BAY THAT YOU CAN
FOLLOW BACK TO SHOWERS IN THE DULUTH AREA AND ASSOCIATED WITH THE
ARRIVAL OF THE ELEVATED CAPE. AT THE NOSE OF THE LLJ AND EDGE OF THE
CAPPING INVERSION /WHERE H7 TEMPS EXCEED +9C/ YOU WILL FIND A BROKEN
LINE OF STORMS ALONG THE MN/IA. MPXWRF AND SPCWRF PRETTY MUCH NAILED
THESE STORMS...SO FOLLOWED THE TREND OF THESE MODELS FOR WORKING
HIGHER POPS SOUTH OF A MANKATO/RED WING/CHIP FALLS LINE THROUGH THE
MORNING. GIVEN THE RAPS DEPICTION OF THE LLJ VEERING MORE EASTERLY
THROUGH THE MORNING WITH LITTLE DEVELOPMENT NORTH...IT MAKES SENSE
THAT THESE STORMS WILL NOT BUILD MUCH FARTHER NORTH OF THEIR CURRENT
LATITUDE AND WILL INSTEAD HEAD MORE OR LESS DOWN I-90 INTO CENTRAL
WI WITH THE LLJ. NOT EXPECTING MUCH SEVERE POTENTIAL OUT OF
THESE...BUT WITH EFFECTIVE SHEAR UP NEAR 30 KTS AND CAPE BETWEEN
-10C AND -30C /HAIL CAPE/ UP AROUND 500 J/KG...WE WILL LIKELY
CONTINUE TO SEE THE OCCASIONAL STORM PUT OUT HAIL THAT GETS UP IN
THE 1 INCH TERRITORY OR SLIGHTLY LARGER.
BEHIND THIS MORNING ACTIVITY...H7 TEMPS WILL PUSH UP TO BETWEEN 8
AND 10C...WITH A VERY DRY PLUME OF AIR COMING IN IN THE H7-H5 LEVEL
AS WELL. THIS WILL LIKELY KEEP THE MPX AREA CAPPED AND DRY MUCH OF
THE DAY AS WE WATCH THE WARM FRONT LIFT NORTH ACROSS IOWA. BY PEAK
HEATING...THIS WARM FRONT LOOKS TO BE UP NEAR I-90. WARM SECTOR
COMING UP WITH THIS FRONT IS THE SAME AIRMASS THAT HAS SPENT THE
LAST THREE DAYS BREAKING RECORD HIGHS ACROSS TX/OK/KS...SO IT WILL
BE WARM TO SAY THE LEAST...WITH HIGHS IN THE 90S LIKELY CLEAR UP TO
THE I-80 CORRIDOR. THIS WARM FRONT STILL MAKES FOR A DIFFICULT
FORECAST AS OVERCAST CONDITIONS TO THE NORTH OF THE FRONT WILL HOLD
HIGHS BACK IN THE 50S/60S...WHILE SOUTH OF THE BOUNDARY IT WILL BE
FEELING LIKE SUMMER. CONTINUED TO FAVOR THIS FORECAST TOWARD THE
ECMWF...WHICH HAS MID 80S ALONG I-90 THAT FALL BACK TO THE UPPER
50S/LOWER 60S NORTH OF I-94. WE WILL HAVE TO WATCH THOSE TEMPS
THOUGH. THERE IS VIRTUALLY NO CLOUD COVER ACROSS IOWA RIGHT
NOW...AND IF THIS TREND CONTINUES OVER US THIS AFTERNOON...THEN
SOMETHING MUCH CLOSER TO WHAT THE RAP HAS BEEN SHOWING ALL MORNING
IS POSSIBLE...WHICH IS LOWER 90S COMING UP AS FAR NORTH AS
MANKATO/REDWOOD FALLS...WITH HIGHS CLOSER TO 80 IN THE CITIES...WITH
EVEN THE COLDER AREAS AROUND LADYSMITH PUSHING 70.
MAIN QUESTION FOR THIS EVENING/TONIGHT IS WHEN DOES THE CAP BREAK.
ONCE IT DOES...IT IS LOOKING LIKE A VERY ACTIVE NIGHT ACROSS THE MPX
CWA. THROUGH THE AFTERNOON...ANY ACTIVITY LOOKS TO REMAIN TO THE NW
OF THE CAP...WHICH WOULD KEEP THE BULK OF THE ACTIVITY TODAY OUT
FROM CENTRAL SODAK INTO NW MN. EVENTUALLY...A STRENGTHENING LLJ AND
THE APPROACH OF THE MAIN UPPER TROUGH WILL START TO ERODE THE CAP.
GENERALLY FOLLOWED THE IDEA OF THE SPCWRF AND THE NMM/ARW WITH
ACTIVITY TAKING OFF BETWEEN 2Z AND 4Z. GIVEN THE DEGREE OF
INSTABILITY EXPECTED AND EFFECTIVE SHEARS UP AROUND 50 KTS...IT IS
VERY LIKELY THAT THESE STORMS WILL BE ABLE TO PRODUCE LARGE
HAIL...SO THE DAY1 SLIGHT RISK IS MORE THAN WARRANTED. ALTHOUGH NO
CONVECTION IS CURRENTLY ANTICIPATED IN THE AFTERNOON...IF WE WERE TO
SEE SOMETHING GO IT WOULD HAVE A HIGH LIKELIHOOD OF BEING
SEVERE...WITH A TORNADO THREAT IF IT IS CLOSE TO THE WARM FRONT.
HOWEVER...THE WARM/DRY LAYER NOTED EARLIER AROUND H7 WILL MOST
LIKELY KEEP ANYTHING FROM GOING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 434 AM CDT WED MAY 7 2014
THE EXTENDED PERIOD WILL BE AN ACTIVE ONE WITH ONLY ONE DRY PERIOD
FORECAST AND THAT IS FRIDAY NIGHT. THURSDAY IS THE DAY OF
INTEREST. ALL INDICATIONS ARE FOR LOW PRESSURE OVER EASTERN
NEBRASKA THURSDAY MORNING TO SLOWLY DEEPEN WHILE MOVING INTO
SOUTHWEST MINNESOTA DURING THE AFTERNOON AND INTO CENTRAL
MINNESOTA DURING THE EVENING. CONVECTION IS ANTICIPATED TO BE
ONGOING THURSDAY MORNING ACROSS CENTRAL MN AND WEST CENTRAL WI.
THIS WILL MOVE NORTHEAST EARLY ON ALLOWING FOR THE DESTABILIZATION
TO COMMENCE. PROJECTIONS FOR THE AFTERNOON AND EVENING HOURS ARE
FOR 0-1KM SHEAR TO BE IN THE 25-35 KNOT RANGE AHEAD OF THE LOW AND
COLD FRONT WITH 0-6KM SHEAR IN THE 40-50 KNOT RANGE. EASTERN MN
AND WESTERN WI ARE ALSO IN A FAVORABLE COUPLED JET ALOFT WITH 100
KNOT RIGHT ENTRANCE REGION OVER NORTHERN MN WHILE A 100+ KNOT JET
SURGES INTO EASTERN IA DURING THE AFTERNOON. THE DIFFERENTIAL
DIVERGENCE IS QUITE STRONG BY EVENING ACROSS THE TWIN CITIES.
ALSO...VARIOUS SOLUTIONS ARE POINTING TO 0-3KM CAPE REACHING
100-150 J/KG BY LATE IN THE AFTERNOON...AGAIN CLOSE TO THE TWIN
CITIES. HENCE...A SEVERE AFTERNOON AND EVENING IS LOOKING MORE AND
MORE LIKELY WITH ALL FORMS OF SEVERE WEATHER POSSIBLE INCLUDING A
FEW TORNADOES. THE SEVERE THREAT SHOULD BE OVER BY MIDNIGHT ACROSS
WESTERN WI AS THE ATTENDANT COLD FRONT MOVES THROUGH. HIGHS ON
THURSDAY HAVE POTENTIAL TO RUN INTO THE 80S FROM THE TWIN CITIES
ON SOUTH AND SOUTHWEST. BLENDED GUIDANCE KEPT HIGHS IN THE UPPER
70S.
A FEW SHOWERS MAY LINGER OVER NORTHERN AND EASTERN AREAS OF THE FA
ON FRIDAY UNDER THE COLD UPPER TROUGH. AS MENTIONED EARLIER...FRIDAY
NIGHT IS THE ONLY DRY PERIOD AS A WEAK RIDGE OF HIGH PRESSURE
MOVES THROUGH. THE PATTERN STARTS TO BECOME MORE ACTIVE AGAIN ON
SATURDAY AS NORTHERN AND SOUTHERN STREAM ENERGY BEGIN TO
INFLUENCE THE WESTERN HALF OF THE CONUS. THIS DEVELOPS ANOTHER
WAVE OF LOW PRESSURE TO OUR SOUTHWEST WITH SHOWER CHANCES
INCREASING THROUGH THE WEEKEND AND EARLY NEXT WEEK. SOME
SIGNIFICANT DIFFERENCES EXIST BETWEEN THE GFS AND EC BY EARLY NEXT
WEEK ON THE LOCATION OF THE SURFACE LOW. THE GFS WOULD BE FLATTER
AND FURTHER EAST WITH THE LOW WHILE THE EC IS MORE ROBUST WITH
THE UPPER TROUGH AND SURFACE LOW. THIS WILL NEED TO BE WATCHED AS
WE COULD BE CLOSE TO THE WARM SECTOR ALONG WITH A SEVERE WEATHER
THREAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1247 AM CDT WED MAY 7 2014
AT ABOUT 530Z...TSRA STARTED BUBBLING UP TO THE SOUTH OF
FSD...RIGHT ABOUT WHEN/WHERE THE HRRR AND MPXWRF HAD THEM
FORMING. FOLLOWED THOSE MODELS FOR TIMING WHAT SHOULD BE A LINE OF
TSRA TO NEAR THE EAU AREA BETWEEN 12Z AND 14Z. THIS ACTIVITY LOOKS
TO REMAIN SOUTH OF RWF/MSP...BUT LOOKS TO GET CLOSE ENOUGH TO
WARRANT A CONTINUED MENTION OF A VCSH. ALSO NEEDED TO SLOW DOWN THE
ARRIVAL OF ANY SHRA AS WELL AND ALSO SIGNIFICANTLY SLOWED DOWN THE
ARRIVAL OF MVFR OR LOWER CIGS. FOLLOWED THE NAM/HRRR IDEA WITH
CIGS REMAINING MORE AROUND 4K FT MUCH OF THE DAY UNTIL THE WARM
FRONT GETS CLOSER TO EACH TERMINAL...WHICH IS WHEN A SIGNIFICANT
DROP IN CIGS IS ANTICIPATED. WITH CIGS TO THE NORTH OF THE WARM
FRONT ACROSS IA STILL UP BETWEEN 5K AND 7K FT...FOUND IT HARD TO
BELIEVE THE GFSLAMP FOR HOW AGGRESSIVE IT IS WITH BRINGING IN THE
LOWER CIGS. NOT EXPECTING ANY PRECIP ON WED...BUT FAVORED THE
SPCWRF FOR HOW MORE WIDESPREAD TSRA ACTIVITY GOES DOWN AT THE END
OF THE TAF PERIOD.
KMSP...CONFIDENCE IS HIGH THAT TSRA TONIGHT/WED MORNING WILL
REMAIN SOUTH OF THE FIELD...BUT MAY BE CLOSE ENOUGH TO IMPACT ANY
DEPARTING/ARRIVING TRAFFIC. LESS CONFIDENCE IN CIG FORECAST AS THE
APPROACH OF THE WARM FRONT COINCIDING WITH PEAK HEATING MAY MAKE
IT TOUGH FOR MVFR CIGS TO DEVELOP EVEN AS EARLY AS 6Z TAF HAS IT.
CONFIDENCE MUCH HIGHER IN TSRA IMPACTING THE FIELD WED
NIGHT...THOUGH LESS CONFIDENCE ON TIMING. THE WARM FRONT LOOKS TO
SURGE NORTH AFTER 00Z...WHICH SHOULD AID IN THE RAPID EXPANSION OF
TSRA ACROSS MN. ONCE STORMS START...COULD BE A VERY LONG NIGHT FOR
SEEING ACTIVITY IN THE AREA.
/OUTLOOK FOR KMSP/
THU...VFR EARLY WITH IFR/TSRA LIKELY IN THE AFTERNOON. SOME STORMS
MAY BE SEVERE. WINDS SE BECOMING S AT 10G20KTS.
FRI...MVFR EARLY...THEN VFR. WINDS W AT 10G20KTS.
SAT...VFR. WINDS S 5-10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
105 AM CDT WED MAY 7 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 249 PM CDT TUE MAY 6 2014
A DEFUSE WARM FRONT WAS LOCATED OVER NORTHERN MISSOURI AND NORTHERN
KANSAS AT 3 PM WHICH WILL ADVANCE SLOWLY NORTHWARD TO THE I-80
CORRIDOR BY EARLY WEDNESDAY MORNING. THIS WILL NOT DO MUCH TO
GENERATE STORMS. INSTEAD...THE MAIN FORCING MECHANISM FOR STORM
DEVELOPMENT TONIGHT WILL BE STRONG WAA AT 850 MB...KICKED OFF BY A
STRENGTHENING LLJ THIS EVENING. AS THE INVERSION AT 850 CONTINUES TO
INCREASE...ELEVATED INSTABILITY WILL GROW ABOVE THIS LEVEL...BUT
CAPPING AT THIS LEVEL WILL ALSO MAKE IT MORE DIFFICULT TO GENERATE
STORMS AWAY FROM THE FORCING OF THE JET. THE BEST POTENTIAL FOR
STORMS WILL BE ACROSS SOUTHERN MINNESOTA AND PORTIONS OF SOUTHWEST
AND WEST CENTRAL WISCONSIN...MAINLY SOUTH OF A LINE FROM HUDSON TO
LADYSMITH. SYNOPTIC MODELS SEEM TO HAVE A GOOD HANDLE ON THIS IN
TERMS OF QPF PLACEMENT...BUT THE MOST RECENT RUN OF THE HOPWRF /15Z/
SHOWS STORMS INITIATING FURTHER NORTH INCLUDING THE REDWOOD
FALLS...TWIN CITIES...AND NEW RICHMOND AREAS AROUND MIDNIGHT.
THUS...ENOUGH UNCERTAINTY STILL EXISTS TO PREVENT US FROM REDUCING
POPS TOO MUCH ACROSS EASTERN MINNESOTA AND NORTHWESTERN WISCONSIN.
LIKELY OR CATEGORICAL POPS ARE STILL IN PLACE TO THE SOUTH. BROAD
ISENTROPIC LIFT ACROSS THE UPPER MIDWEST WILL BRING THE REST OF THE
AREA A SLIGHT CHANCE OF STORMS...INCLUDING WESTERN AND CENTRAL
MINNESOTA. MODEST AMOUNTS OF SHEAR WILL KEEP SEVERE WEATHER CHANCES
MARGINAL...HOWEVER A SEVERE STORM OR TWO ARE CERTAINLY POSSIBLE FROM
SOUTH CENTRAL MN TO WEST CENTRAL WI GIVEN STEEPENING MID LEVEL LAPSE
RATES.
WEDNESDAY WILL BE MOSTLY DRY. WITHOUT THE LLJ...NOT MUCH FORCING
WILL EXIST TO OVERCOME SIGNIFICANT CAPPING BETWEEN 700-800 MB. BEST
POTENTIAL FOR DEVELOPMENT WILL BE ACROSS WESTERN MN WHERE A SURFACE
LOW LIFTING NORTH MAY ERODE SOME OF THE STRONG CAPPING. THIS LOW
WILL ALSO DRAG THE WARM FRONT FROM IOWA NORTHWARD INTO FAR SOUTHERN
MINNESOTA DURING THE AFTERNOON. MODELS ARE ALL OVER THE PLACE IN
TERMS OF PLACEMENT...AND THIS WILL PLAY A BIG ROLE IN HOW WARM
LOCATIONS GET. SOUTH OF THE FRONT...LOW TO MID 80S WILL BE EASILY
ATTAINABLE WITH EVEN 90S ACROSS EASTERN NEBRASKA AND IOWA...BUT
NORTH WILL BE SOCKED IN CONSIDERABLE CLOUDS AND AN EASTERLY FLOW
KEEPING TEMPS IN THE UPPER 50S AND 60S. GEM SEEMS A BIT TOO FAR
NORTH WITH THE FRONT REACHING CENTRAL MN...WHEREAS THE GFS DOES NOT
SEEM AGGRESSIVE ENOUGH KEEPING IT ACROSS NORTHERN IOWA. SPLIT THE
DIFFERENCE FOR THE GRIDS...WHICH MATCHES BEST WITH THE NAM AND ECMWF
BRINGING 80S UP TO THE I-90 CORRIDOR.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 249 PM CDT TUE MAY 6 2014
A STRONG STORM SYSTEM IS STILL FORECAST TO IMPACT THE AREA
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. THERE REMAINS SOME
MODEL DISAGREEMENTS IN TERMS OF OVERALL TRACK AND TIMING OF THE
SFC LOW...AND THE STRENGTH OF A DRY SLOT TO AFFECT THE AREA. THEN
THE LONGER RANGE MODELS SHOW ANOTHER POTENTIAL SYSTEM MOVING
ACROSS THE AREA SAT NIGHT/SUN WITH HINTS AT ANOTHER STRONG STORM
SYSTEM FOR THE BEGINNING OF NEXT WEEK.
INTO WEDNESDAY NIGHT...THE STRENGTHENING LLJ WILL LEAD TO BETTER
CHANCES FOR STORMS NORTH OF THE WARM FRONT. WE HAVE CONTINUED TO
TREND POPS FROM AROUND 70% FOR CENTRAL MN TO JUST 30% DOWN TOWARD
I-90. MID LEVEL FLOW IS FORECAST TO INTO TO NEAR 50 KTS/MUCAPE
OVER 2000 J/KG AND MID LEVEL LAPSE RATES FROM 8-9C/KM...THERE
WILL BE AMPLE OPPORTUNITY FOR THIS ACTIVITY TO BE SEVERE...WITH
LARGE HAIL BEING THE MAIN THREAT GIVEN THE ELEVATED NATURE OF THE
ACTIVITY NORTH OF THE WAR FRONT.
FOR THURSDAY...THERE REMAINS SOME UNCERTAINTY WITH HOW THE EVENT
WILL DEVELOP. PREVIOUS CONVECTION WILL HAVE SOME AFFECT ON
OVERALL DEVELOPMENT EARLY IN THE PERIOD..AND HOW FAR NORTH THE
WARM SECTOR WILL MOVE. THE GFS AND ECMWF HAVE COME INTO SOME
AGREEMENT ON SLOWER MOVEMENT OF THE UPPER TROUGH AND THE MOVEMENT
OF THE SURFACE LOW. THERE WILL LIKELY BE SOME SCATTERED CONVECTION
OVER THE NORTHERN CWA EARLY THURSDAY. DEVELOPMENT WILL LIKELY
INITIATE EARLY INTO THE SOUTHWEST...WITH LIKELY POPS AGAIN OVER
MUCH OF THE AREA AFTER 15Z. CATEGORICAL POPS REMAIN OVER THE NORTH
AND EAST PART OF THE CWA INTO THE AFTERNOON AS WELL...AS THE
SURFACE LOW LIFTS NORTHEAST ACROSS THE CENTRAL CWA. THE GFS IS
INDICATING SOME HIGH PROBABILITIES OF TORNADO DEVELOPMENT INTO
CENTRAL AND EASTERN CWA INTO THE AFTERNOON. WE CERTAINLY HAVE
ENOUGH INSTABILITY AND FORCING/110KT 30H JET MAX NOSING INTO
EASTERN MN DURING THE AFTERNOON. THE 12Z ECMWF IS SLOWER WITH
DEVELOPMENT INTO THE AFTERNOON BUT IT DEVELOPS EVEN A LARGER AREA
OF HEAVY RAIN OVER THE CENTRAL AND EASTERN PORTIONS OF THE AREA.
AT THE MOMENT...THE SLIGHT RISK FOR MUCH OF THE AREA IS
WARRANTED....WITH HAIL AND STRONG WINDS A GOOD BET. CANT RULE OUT
THE ISOLATED TORNADO HOWEVER.
THE GFS AND ECMWF CONTINUE TO SHOW A WEAK WAVE LIFTING EAST OVER
THE AREA SATURDAY NIGHT/SUNDAY TIME FRAME. THEN THEY DIVERGE HOWEVER
...WITH THE ECMWF MUCH SLOWER WITH THE WESTERN CONUS TROUGH...AND
IT AFFECTS THIS REGION INTO EARLY NEXT WEEK. WILL HAVE TO HOLD
ONTO SOME LOW CHANCE POPS DURING THIS PERIOD BECAUSE OF MODEL
DISCREPANCIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1247 AM CDT WED MAY 7 2014
AT ABOUT 530Z...TSRA STARTED BUBBLING UP TO THE SOUTH OF
FSD...RIGHT ABOUT WHEN/WHERE THE HRRR AND MPXWRF HAD THEM
FORMING. FOLLOWED THOSE MODELS FOR TIMING WHAT SHOULD BE A LINE OF
TSRA TO NEAR THE EAU AREA BETWEEN 12Z AND 14Z. THIS ACTIVITY LOOKS
TO REMAIN SOUTH OF RWF/MSP...BUT LOOKS TO GET CLOSE ENOUGH TO
WARRANT A CONTINUED MENTION OF A VCSH. ALSO NEEDED TO SLOW DOWN THE
ARRIVAL OF ANY SHRA AS WELL AND ALSO SIGNIFICANTLY SLOWED DOWN THE
ARRIVAL OF MVFR OR LOWER CIGS. FOLLOWED THE NAM/HRRR IDEA WITH
CIGS REMAINING MORE AROUND 4K FT MUCH OF THE DAY UNTIL THE WARM
FRONT GETS CLOSER TO EACH TERMINAL...WHICH IS WHEN A SIGNIFICANT
DROP IN CIGS IS ANTICIPATED. WITH CIGS TO THE NORTH OF THE WARM
FRONT ACROSS IA STILL UP BETWEEN 5K AND 7K FT...FOUND IT HARD TO
BELIEVE THE GFSLAMP FOR HOW AGGRESSIVE IT IS WITH BRINGING IN THE
LOWER CIGS. NOT EXPECTING ANY PRECIP ON WED...BUT FAVORED THE
SPCWRF FOR HOW MORE WIDESPREAD TSRA ACTIVITY GOES DOWN AT THE END
OF THE TAF PERIOD.
KMSP...CONFIDENCE IS HIGH THAT TSRA TONIGHT/WED MORNING WILL
REMAIN SOUTH OF THE FIELD...BUT MAY BE CLOSE ENOUGH TO IMPACT ANY
DEPARTING/ARRIVING TRAFFIC. LESS CONFIDENCE IN CIG FORECAST AS THE
APPROACH OF THE WARM FRONT COINCIDING WITH PEAK HEATING MAY MAKE
IT TOUGH FOR MVFR CIGS TO DEVELOP EVEN AS EARLY AS 6Z TAF HAS IT.
CONFIDENCE MUCH HIGHER IN TSRA IMPACTING THE FIELD WED
NIGHT...THOUGH LESS CONFIDENCE ON TIMING. THE WARM FRONT LOOKS TO
SURGE NORTH AFTER 00Z...WHICH SHOULD AID IN THE RAPID EXPANSION OF
TSRA ACROSS MN. ONCE STORMS START...COULD BE A VERY LONG NIGHT FOR
SEEING ACTIVITY IN THE AREA.
/OUTLOOK FOR KMSP/
THU...VFR EARLY WITH IFR/TSRA LIKELY IN THE AFTERNOON. SOME STORMS
MAY BE SEVERE. WINDS SE BECOMING S AT 10G20KTS.
FRI...MVFR EARLY...THEN VFR. WINDS W AT 10G20KTS.
SAT...VFR. WINDS S 5-10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...BORGHOFF
LONG TERM...DWE
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
910 PM CDT THU MAY 8 2014
.UPDATE...
A FEW SHOWERS MOVING INTO THE WESTERN PART OF THE CWA CURRENTLY.
WITH A DECENT LAYER OF VERY DRY AIR IN THE MID-LEVELS...THESE SHOWERS
WILL HAVE DIFFICULTY REACHING THE GROUND THE FURTHER EAST THEY
TRAVEL. HOWEVER...MOISTURE WILL BE INCREASING FROM THE SOUTHWEST THROUGH
THE NIGHT AND SO BY MORNING A WIDESPREAD SWATH OF RAINFALL CAN BE
EXPECTED TO TAKE OVER MUCH OF THE AREA. STILL NOT EXPECTING ANY
SEVERE STORMS WITH THIS ACTIVITY. UPDATED THE POPS TO COVER THE
APPROACHING RAINFALL OVERNIGHT AND TOOK OUT THE MENTION OF THUNDER IN
MOST OF THE AREA OVERNIGHT AS WELL. /10/
&&
.AVIATION...
VFR CONDITIONS CURRENTLY PREVAIL WITH THICK MID AND HIGH LEVEL
CLOUDINESS ACROSS MOST AREAS. DEEPER AND RICHER LOW LEVEL MOISTURE
REMAINS S AND W OF AREA PER SURFACE OBS AND 00Z SOUNDINGS. EXPECT
THIS MOISTURE TO INCREASE ACROSS AREA TONIGHT...WITH DEVELOPMENT OF
STRATUS FROM THE S. HRRR RUNS SHOW VFR CONDITIONS GENERALLY HOLDING
THROUGH AT LEAST 06Z...WITH DETERIORATION TO MVFR AND POTENTIALLY IFR
THROUGH 12Z. LOWEST CIGS/VSBYS EXPECTED IN SE AREAS WHERE SOMEWHAT
WEAKER LOW LEVEL FLOW SHOULD EXIST. HIGH RESOLUTION MODELS AGREE ON
CONVECTION WORKING INTO AREA FROM WEST WITH GREATEST COVERAGE THROUGH
18Z REMAINING WEST OF I-55. WILL CARRY SOME CATEGORICAL MVFR
CIGS/VSBYS IN RA WITH VCTS THESE AREAS. /08/
&&
.PREV DISCUSSION... /ISSUED 355 PM CDT THU MAY 8 2014/
SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT...MOISTURE WILL BE ON THE
INCREASE TONIGHT FROM THE WEST AS A DISTURBANCE APPROACHES THE
REGION. SOME SHOWER AND STORM ACTIVITY LOOKS POSSIBLE AFTER MIDNIGHT
INTO EARLY FRIDAY MORNING ESPECIALLY ACROSS THE DELTA REGION.
INSTABILITY LOOKS SUFFICIENT FOR SOME STRONG STORMS TO
DEVELOP...WITH AN ISOLATED SEVERE STORM NOT OUT OF THE QUESTION.
SHOWERS AND STORMS WILL CONTINUE INTO FRIDAY AFTERNOON AND EVENING
AS ANOTHER SHORT WAVE MOVES ACROSS THE AREA. SOME STORMS COULD
PRODUCE 1-3 INCHES OF RAIN AND GUSTY WINDS OF 40-50 MPH. SOUTHERLY
FLOW CONTINUING SATURDAY WILL ALLOW FOR DECENT MOISTURE
TRANSPORT...ALLOWING FOR THE POSSIBILITY FOR MORE SHOWER AND
THUNDERSTORM ACTIVITY. SOME STRONG STORMS WILL BE POSSIBLE AS WELL.
/27/
LONG TERM...SUNDAY THROUGH MUCH OF NEXT WORK WEEK...MID TO UPPER
LEVEL FLOW SHOULD WEAKEN RATHER SUBSTANTIALLY OVER OUR REGION AS THE
WESTERLIES BEGIN TO CONSOLIDATE TOWARD A BUILDING TROUGH IN THE
WESTERN CONUS. DESPITE THIS EVOLUTION EXPECT MOIST SOUTHERLY FLOW
OFF THE GULF OF MEXICO TO CONTINUE INTO THE LOWER MISSISSIPPI VALLEY
PROVIDING ENOUGH INSTABILITY IN THE AFTERNOON TO FUEL ISOLATED
SHOWERS AND STORMS. RATHER TAME LAPSE RATES AND LACKLUSTER SHEAR
SHOULD GREATLY LIMIT THE RISK OF HAZARDOUS WEATHER THROUGH MONDAY.
MODELS STILL SHOWS SOME MINOR TIMING DIFFERENCES ASSOCIATED WITH A
DECENT COLD FRONT EXPECTED TO PUSH THROUGH FROM THE NORTHWEST ON
TUESDAY...BUT WE REMAIN CONFIDENT IT SHOULD CLEAR THE REGION TO THE
EAST BY WEDNESDAY. SHOWERS AND THUNDERSTORMS ARE EXPECTED WITH
FROPA...BUT INDICATIONS ARE THAT ACTIVITY WILL BE LARGELY ANAFRONTAL
(WHICH WILL AGAIN GREATLY LIMIT THE POTENTIAL FOR HAZARDOUS
WEATHER). TEMPERATURES WILL CONTINUE TO RUN ABOVE NORMAL UNTIL THIS
FRONT PASSES...BUT A PLEASANT TREND TOWARD AT LEAST SLIGHTLY BELOW
AVERAGE TEMPS AND DRY WEATHER IS ANTICIPATED FOR SEVERAL DAYS
FOLLOWING FRONTAL PASSAGE. /BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 68 82 65 85 / 43 75 43 35
MERIDIAN 66 82 64 85 / 24 77 62 39
VICKSBURG 68 84 67 86 / 52 62 30 32
HATTIESBURG 69 84 66 86 / 16 74 56 58
NATCHEZ 70 83 67 85 / 51 50 29 43
GREENVILLE 69 83 67 86 / 50 68 45 28
GREENWOOD 69 82 66 85 / 46 74 51 29
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
921 PM CDT Thu May 8 2014
.UPDATE:
Issued at 853 PM CDT Thu May 8 2014
A north to south area or band of showers and a few thunderstorms
was moving slowly eastward through east central and southeast MO
and west central and southwest IL. The intensity of the radar
returns have weakened over the St Louis metro area with better
rains both north and south. This precipitation was in a region of
low-mid level warm air advection ahead of a southwest flow
shortwave. This activity will eventually translate east of our
forecast area later this evening, with a break in the
precipitation expected until more showers and storms now across
northwest and west central MO and southeast KS, along and just
ahead of an approaching cold front, shifts into our forecast area
late tonight. The HRRR model also tries to bring some of the
convection now across AR northeastward into southeastern MO late
tonight. Could not rule out isolated hail and strong wind gusts
from the stronger storms late tonight. Mild temperatures should
continue tonight with slight cooling, or cooler temperatures over
the extreme northwestern portion of our forecast area behind the
cold front.
GKS
&&
.SHORT TERM: (Through Late Tonight)
Issued at 256 PM CDT Thu May 8 2014
SHRA/TSRA trends are the primary concern this evening, and are
remaining very difficult to pin down. Early on, N-S band of
showers and thunderstorms now moving into central MO will work its
way east during the remainder of the afternoon and early evening.
Have leaned heavily on the HRRR runs for trends over the next 3-6
hours, as it continues to provide superior guidance on the trends
with this area of convection. Passage of the shortwave fueling
this precip will likely cause area to diminish a bit in coverage
and intensity during the evening, but additional (and hard to
time) upstream shortwaves, as well as persistent WAA and
associated isentropic ascent, should generate additional shower
and thunderstorm activity during the late evening and overnight
hours in the warm sector. Precip threat (especially in our NW
counties) will also be driven by convection that forms along the
cold front and works its way east with time.
Truett
.LONG TERM: (Friday through Next Thursday)
Issued at 256 PM CDT Thu May 8 2014
Overnight elevated SHRA/TSRA forced by the LLJ will probably be
ongoing at daybreak on Fri, at least over part of the CWA. As the
core of the LLJ shifts northeastward into IL/IN, the greatest
moisture convergence and forcing for pcpn will also shift out of
the CWA. Consequently, there should be a decrease in precipitation
coverage or perhaps even a lull during the mid to late morning
hours on Fri. The absence of widespread precipitation combined
with some breaks in the clouds should be sufficient for afternoon
destabilization across the southeastern one-half to one-third of
the CWA. This detail matters because a trough with a vort max in
its base will be approaching from the west. Large scale ascent
from DCVA as well as lift ahead of the cold front will likely
occur in an environment with H7-H5 lapse rates of 6-7.5 deg C/km
and 40-60 kts of 0-6 km bulk shear as well as nearly
unidirectional wind profiles. These parameters are sufficient for
severe thunderstorms with hail and wind as the primary threats.
Although recent model runs all depict a solution where the cold
front moves through most of the CWA on Fri night and then stalls
in southern MO before lifting northward as a warm front on Sat,
the effective boundary might end up much farther south by Sat
morning depending on outflow boundaries from convection on Fri/Fri
night. If this occurs, then the temperature forecast for Sat may
be too warm. Shortwave ridging aloft is expected on Sat with a
compact vort max moving across southern MN, which is much farther
north than yesterday`s model runs. The H85 LLJ associated with the
vort max moving across MN could produce enough lift over the warm
front to support scattered SHRA/TSRA in MO/IL, especially if
forecast H7-H5 lapse rates of 7-8 deg C/km are realized. SHRA/TSRA
are also possible on Sat night due to moisture convergence along a
strengthening southwesterly LLJ.
A new trough develops out west over the weekend, inducing surface
cyclogenesis over the plains and eventually sending another cold
front through MO/IL early next week. Models disagree on how
quickly the trough shifts eastward into the central CONUS, leading
to disagreements on how quickly the cold front moves through the
LSX CWA. It appears that there will be a period of northwest flow
or cyclonic flow during the middle of next week depending on how
the trough evolves. Expect cooler temperatures in such a pattern
with precip chances dependent on shortwaves and moisture
availability.
Kanofsky
&&
.AVIATION: (For the 00z TAFs through 00z Friday Evening)
Issued at 601 PM CDT Thu May 8 2014
Band of showers and thunderstorms will continue to move east this
evening. The rain will be moving out of KCOU soon, but persist at
KUIN through mid evening, and will soon move into the St. Louis
metro TAF sites and persist through 04-05Z. Expect MVFR
conditions with the rain, and some of the heavier cores could
briefly produce IFR visibilities. This band will then move out and
expect a period of dry and VFR conditions before another round of
showers and scattered thunderstorms moves through the area
overnight and early Friday morning. This will coincide with an
area of low MVFR ceilings that will persist through mid-late
morning before slowly improving to VFR.
Specifics for KSTL: Showers and thunderstorms will move into the
terminal by 01Z, though scattered thunderstorms will be in the
area before then. Expect MVFR conditions with the rain. This first
area of rain will move out around 04Z, but then expect another
round of showers and scattered thunderstorms to move through the
terminal starting around 09Z. Low MVFR conditions are expected
with this second round that will persist after the rain ends. VFR
ceilings are not expected until midday. Thunderstorms are expected
to develop in the vicinity of KSTL tomorrow afternoon and then
move east of the airport by 00Z.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
754 PM CDT Thu May 8 2014
.UPDATE...
Issued at 730 PM CDT THU MAY 8 2014
Surprisingly busy evening. Shield of rain with embedded
convection has proved to be interesting, with some isolated damage
reports with brief bowing/spin up vorts in shallow convective
cells/elements. Low level 0-1km helicity actually fairly stout
over the Mo Ozarks this afternoon/evening. Overall trend of the
eastern cwfa convection is downward and expect that trend to
continue.
Deeper scattered convection is occurring ahead of a cold front over
eastern KS with the most notable updrafts w-nw-n of KCNU. Storms
having a tough time of it, but still seeing a stronger updraft or
two firing up. MLCAPE of around 1000 J/kg is occurring just ahead
of the front, but drops off quite a bit has you head east-se into
MO. 0-6km bulk shear more than adequate for storm organization
where somewhat stronger instability occurs over se KS and far
western MO later this evening. HRRR however, really not doing much
with the existing convection owing to a lack of progged overall
instability. Will watch trends, but the weakening trend of the
HRRR looks good later this evening.
Later tonight, a veering low level jet and moisture advection
should allow some additional elevated convection to develop
overnight into Friday morning ahead of the low level front with
the approach of shortwave/upper jet max.
&&
.SHORT TERM...(This Evening and Tonight)
Issued at 300 PM CDT THU MAY 8 2014
An upper level trough is currently pushing east into the central
Plains as an associated area of surface low pressure pushes
northeast across eastern Nebraska. A cold front ALSO extends south
from the low and is pushing east across central Kansas and
Oklahoma.
Convection is ongoing across the area. This activity formed over
Oklahoma overnight and continues to develop and push to the
northeast. These showers and thunderstorms will continue to track
northeast across the area this afternoon into the early evening
hours. Deep layer shear is on the weak side across the area.
Instability is starting to increase across the eastern Ozarks as
more heating was able to occur in these locations before clouds
were able to overspread the area. The overall severe potential is
on the low side with this activity, but with slightly better
instability there could be a few strong wind gusts with any bow
segments that can develop this afternoon and early this evening.
This activity will push east of the area by the early to mid
evening hours.
The clouds are clearing from west to east across eastern Kansas
into central Oklahoma behind this convection. We will have to see
how far east the clearing can make it this afternoon/early this
evening. The clearing will likely make it over to the far western
portion of the forecast area. Additional thunderstorms are
expected to develop across northeastern Oklahoma into eastern
Kansas along a cold front late this afternoon into this evening.
This activity will then track to the northeast and may clip
southeastern Kansas and far western Missouri. Deep layer wind
shear will begin to increase from west to east this evening and if
enough clearing occurs and enough instability can develop, hail in
excess of quarters will be possible with stronger storms. These storms
may congeal into a line and track east across the area. If the
line does develop winds in excess of 60mph will be possible. There
would also be a small risk for a brief tornado within this line
generally northwest of a Columbus Kansas to Osceola Missouri Line
this evening.
The cold front will then slowly sag southeast towards the area late
this evening into the overnight hours. Showers and thunderstorms
are expected to develop and ride along the front overnight. The
front will push over the far northern and western portions of the
forecast area tonight. Locally heavy rainfall will occur where the
training of storms can occur along the front. Due to the dry
antecedent conditions the overall flood risk is low with this
potential heavy rainfall.
.LONG TERM...(Friday through Thursday)
Issued at 300 PM CDT THU MAY 8 2014
An active weather pattern will continue Friday into early next
week as the a couple storm system track through the region.
Any convection that develops overnight tonight should push east of
the area by Friday morning, with clearing expected behind this
activity. The cold front will continue to track southeast through
the area on Friday. Areas southeast of the front will become
unstable. Better deep layer shear will be over the region on
Friday afternoon allowing organized updrafts. Additional
thunderstorms will develop along the front, and these storms will
have the potential to become strong a severe. The main risk will
be large hail with a few of the strongest storms capable of hail
to golf balls generally along and southeast of the Interstate 44
corridor. The front will push south of the area Friday evening
with dry conditions overnight Friday.
The front will then lift back north across the area Saturday.
Thunderstorms area expected to develop along and north of the
front as it lifts through the region. A few of these storms could
become strong to severe with large hail the main risk. South of the
front instability will increase but there will not be much in a way
of lift, and a cap will be increasing through the day as a warm
air mass in the mid level spreads over the area. So, think all in all
most of the activity will occur along and ahead of the front on
Saturday.
Another upper level system will track through the region late this
weekend into early next week. Medium range models continue to
differ on the track, timing, and strength of this system. The cold
front will sag south then sweep through the region as the upper
level trough approaches and sweeps through the region. Additional
severe storm potential will be possible, but details/evolution of
storms are lacking this far out in time.
Northwest flow aloft pattern will setup over the region behind
this system through the middle of next week behind this system.
Cooler conditions will occur across the region in this northwest
flow pattern.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 730 PM CDT THU MAY 8 2014
For the KSGF/KJLN/KBBG tafs: Expect periods of
showers/thunderstorms to be possible as a sfc front approaches the
region. Best chances for precip and lower ceilings, mvfr/possible
ifr at times, will be the 06z-15z time frame as an upper level
disturbance moves through the region. Lower ceilings should
improve after 15z with precip exiting the area and diurnal heating
allowing lower ceilings to lift.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
UPDATE...DSA
SHORT TERM...Wise
LONG TERM...Wise
AVIATION...DSA
AREA FORECAST DISCUSSION
NWS BILLINGS MT
324 PM MDT WED MAY 7 2014
.SHORT TERM...VALID FOR THU AND FRI...
AREAS OF RAIN/SNOW CONTINUE THIS AFTERNOON AS WE CONTINUE TO BE
AFFECTED BY SLOW MOVING TROF OVER THE NORTHERN/CENTRAL ROCKIES
AND DEEP UPSLOPE FLOW...THOUGH WITH DIMINISHED PCPN RATES. MID AND
UPPER LEVEL DRY SLOTTING IS IMPACTING OUR SOUTH CENTRAL AND
SOUTHEAST PARTS...SO HAVE DROPPED THE ADVISORY FOR THE BIG HORNS.
COLDER TOPS CONTINUE FOR OUR WEST...AND SOME CONVECTION IN WESTERN
WY MAY FEED INTO THE MTNS OVER THE NEXT FEW HOURS...SO WILL LET
THE WARNING FOR THE BEARTOOTH ABSAROKAS RIDE INTO THE EVENING.
COLE CREEK SNOTEL IN THE MTNS ABOVE RED LODGE HAS ALREADY PICKED
UP AT LEAST A FOOT OF SNOW SINCE YESTERDAY. OTHERWISE...ONLY
LIGHT PCPN EXPECTED INTO THIS EVENING WITH A GRADUAL TAPERING OFF
TONIGHT AS BEGIN TO PULL IN DRIER AIR FROM THE NW. SFC RIDGING IN
EASTERN MT SUPPORTS LIGHT WINDS TONIGHT...WHICH ALONG WITH THE
ABUNDANT LOW LEVEL MOISTURE IN PLACE SHOULD RESULT IN SOME FOG
TONIGHT ESPECIALLY WITH A LITTLE CLEARING FROM THE NW LATER ON.
12Z GUIDANCE NOT SHOWING MUCH BUT RECENT RAP RUNS SEEM TO BE
TRENDING TOWARD BETTER FOG POTENTIAL AFTER MIDNIGHT. HAVE ADDED
FOG TO THE FORECAST FROM 06-15Z. OTHER IMPACT TONIGHT WILL BE
FREEZING TEMPS FOR MUCH OF THE REGION...SO TAKE PRECAUTIONS IF YOU
HAVE SENSITIVE PLANTS OUTDOORS.
QUIET DAY IN STORE TOMORROW AS HEIGHTS BUILD FROM THE WEST AND WE
BEGIN TO WARM UP. ENERGY COMING OUT OF THE CENTRAL ROCKIES WILL
ALMOST ENTIRELY MISS OUR CWA TO THE SE...SO A DRY FORECAST LOOKS
GOOD FOR TOMORROW AFTER SOME EARLY MORNING FOG OR LIGHT RAIN/SNOW
SHOWERS. HIGHS THURSDAY WILL REACH THE 50S TO LOW 60S...WARMEST
WEST.
NEXT PACIFIC SHORTWAVE WILL PUSH INTO THE NORTHERN ROCKIES
FRIDAY...GIVING US A GOOD CHANCE OF SHOWERS AND A FEW
THUNDERSTORMS. LATEST MODEL TRENDS ARE A BIT FASTER WITH THIS
ENERGY SO COULD SEE SHOWERS IN OUR WEST BY MORNING...SO NOT QUITE
AS GOOD A CONVECTIVE OPPORTUNITY AS A RESULT FOR OUR WEST.
NONETHELESS WITH GOOD QG FORCING HAVE RAISED POPS FRI AND FRI
NITE. MID LEVEL TEMPS WILL COOL ENOUGH TO TURN PCPN BACK TO SNOW
FOR OUR MTNS BY FRI EVENING...WITH A BIT OF ACCUMULATION FOR THE
MTNS FRI NITE. SHOULD ALSO SEE SOME GUSTY W-NW WINDS FRI AFTN AND
EVENING PER THE FRONTAL PASSAGE AND SHOWER ACTIVITY. HIGH TEMPS ON
FRI WILL REACH THE 60S...AND PERHAPS NEAR 70 IN OUR EAST W/ LATER
FROPA.
JKL
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
MODELS ARE COMING INTO BETTER AGREEMENT IN THE EXTENDED PERIOD.
THIS COMING WEEKEND WILL BE SOMEWHAT WET...AFTER A WARMER
FRIDAY...AS A SHORTWAVE MAKES ITS WAY THROUGH SOUTHERN MONTANA.
SNOW LEVELS WILL REMAIN AROUND 6000 FT ACROSS THE REGION...SO MOST
OF THE PRECIP SHOULD BE IN THE FORM OF RAIN AT LOWER ELEVATIONS.
AT HIGHER ELEVATIONS...ADDITIONAL SNOW ACCUMULATION IS POSSIBLE.
INTO NEXT WEEK...THE REGION WILL BE UNDER THE INFLUENCE OF
NORTHWESTERLY FLOW ALOFT ON THE EASTERN SIDE OF A RIDGE. SEVERAL
SHORTWAVES WILL ATTEMPT TO RIDE THIS RIDGE INTO SOUTH CENTRAL
MONTANA. THEREFORE...HAVE KEPT POP VALUES AROUND CLIMO UNTIL
CERTAINTY BECOMES CLEARER.
TEMPS WILL REMAIN FAIRLY MILD WELL INTO NEXT WEEK WITH NO
SIGNIFICANT WARMUP IN SIGHT. THE COOLER TEMPERATURES WILL STUNT
THE MELTING OF HIGHER ELEVATION SNOWPACK ANOTHER WEEK. SINGER
&&
.AVIATION...
STILL SOME LINGERING RAIN AND SNOW SHOWERS IN AND AROUND
KBIL...KMLS...AND KSHR THIS AFTERNOON AS THE STORM SYSTEM WORKS
ITS WAY EASTWARD. MOST OF THIS ACTIVITY SHOULD WIND DOWN BY THE
EARLY EVENING HOURS. THE POTENTIAL FOR FOG WILL PRESENT
ITSELF...ESPECIALLY AT KBIL...DURING THE OVERNIGHT HOURS CAUSING
POTENTIAL VISIBILITY ISSUES. SINGER
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 030/057 040/065 043/058 038/057 040/062 042/065 043/062
51/B 04/T 55/W 43/W 33/W 22/W 44/W
LVM 025/061 037/061 036/055 035/056 035/059 038/064 039/064
51/U 16/T 55/W 43/W 33/W 32/W 22/W
HDN 032/057 033/068 039/060 034/060 037/064 039/067 040/064
51/B 03/T 64/W 53/W 33/W 22/W 44/W
MLS 033/057 035/069 043/059 037/058 038/062 041/064 042/060
31/B 02/T 55/W 52/W 23/W 23/W 44/W
4BQ 032/054 034/068 041/059 035/058 036/061 039/064 040/060
52/W 01/B 54/W 32/W 23/W 22/W 33/W
BHK 033/054 032/067 041/059 035/056 036/058 038/060 039/057
31/B 01/U 55/W 42/W 22/W 23/W 33/W
SHR 031/054 031/065 038/056 032/055 034/059 036/063 037/062
52/W 02/T 54/W 44/W 34/W 33/W 33/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER STORM WARNING IN EFFECT UNTIL MIDNIGHT MDT TONIGHT FOR
ZONE 67.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
357 PM CDT WED MAY 7 2014
.SHORT TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 352 PM CDT WED MAY 7 2014
CHANCES FOR THUNDERSTORMS TONIGHT AND THURSDAY ARE THE PRIMARY
FORECAST CONCERNS.
EARLY AFTERNOON SURFACE ANALYSIS SHOWED A FRONTAL BOUNDARY EXTENDING
FROM LOW PRESSURE IN SOUTHEAST SOUTH DAKOTA SOUTHWEST THROUGH
NORTHEAST NEBRASKA. NORTHEAST WINDS NORTHWEST OF THE FRONT WERE
KEEPING TEMPERATURES IN THE 70S THERE...WHILE GUSTY SOUTH WINDS
SOUTHEAST OF THE FRONT HAD PUSHED TEMPS WELL INTO THE 80S WITH SOME
90S ALSO SEEN/EXPECTED. IN OUR SOUTHWEST CWA...DEEPER MIXING WAS
OCCURRING...WITH WINDS BECOMING SOUTHWESTERLY WHICH WERE DRYING LOW
LEVELS AND BOOSTING TEMPERATURES. RELATIVE HUMIDITIES CLOSE TO 15
PERCENT WERE NOSING INTO JEFFERSON/SALINE COUNTIES AS OF 2 PM...AND
WILL LIKELY SPREAD EAST ACROSS RED FLAG WARNING AREA THROUGH THE
AFTERNOON. SO WILL KEEP THAT GOING INTO THE EVENING.
A COUPLE OF AREAS OF POTENTIAL CONVECTION WERE OF NOTE AT EARLY
AFTERNOON. ONE EXTENDING FROM NORTH CENTRAL NEBRASKA INTO SOUTH
DAKOTA...AND THE OTHER ACROSS CENTRAL KANSAS. CONGESTUS-LOOKING
CLOUDS WERE TRYING TO IGNITE IN NORTH CENTRAL NEBRASKA...AND CLOUD
TOP COOLING ALGORITHMS WERE SUGGESTING A SMALL CHANCE FOR THOSE
CLOUDS TO CONVECT. BUT IF THEY DO...THEY WILL MOST LIKELY RIDE NORTH-
NORTHEAST INTO SOUTH DAKOTA. SIGNIFICANT CONVECTIVE INHIBITION WAS
NOTED OVER THIS AREA...SO THERE IS A MUCH BETTER CHANCE NOTHING WILL
GO CLOSE TO OUR AREA...FOCUSING ACTIVITY MORE IN WESTERN NEBRASKA
AND THE FOOTHILLS WHERE INHIBITION IS LOW.
KANSAS POTENTIAL CONVECTION WAS BUBBLING UP UNDER INCREASING MID
LEVEL WIND FIELD AHEAD OF TROUGH APPROACHING THE SOUTHERN
ROCKIES...AND WHERE SURFACE TEMPERATURES WERE WELL INTO THE 90S.
DRYLINE WAS IN THIS AREA AS WELL...ADDING LOW LEVEL CONVERGENCE INTO
THE MIX. ALSO OF NOTE...MESOSCALE MODELS RAP AND HRRR ALONG WITH
NAM12 EVENTUALLY BUBBLE CONVECTION NORTH AND NORTHEAST OF THIS AREA
LATER THIS EVENING...AND MOVE THAT INTO EASTERN NEBRASKA AND
SOUTHWEST IOWA WHERE INTERACTION WITH SURFACE FRONT WILL ENHANCE
POTENTIAL. CINH IS LOWERING DRAMATICALLY ACROSS SOUTHEAST NEBRASKA
WHERE DEW POINTS HAD ONLY MIXED INTO THE 50S...WITH OVER 2000 J/KG
MUCAPE AVAILABLE. SO GIVEN INSTABILITY...FRONT IN THE AREA...AND A
PREPONDERANCE OF MODEL DATA FIRING CONVECTION...WILL ADD AT LEAST
SMALL POPS TO MOST OF OUR AREA THIS EVENING AND OVERNIGHT. SOME
STORMS COULD APPROACH SEVERE...WITH AT LEAST SMALL HAIL AND GUSTY
WINDS POSSIBLE.
THEN LATER TONIGHT...STORMS FIRING IN THE NEBRASKA PANHANDLE REGION
IS FORECAST TO SLOWLY SHIFT EAST-NORTHEAST OVERNIGHT...AND COULD
REACH PARTS OF NORTHEAST NEBRASKA BEFORE MORNING. OTHERWISE EXPECT
ANY MORNING STORMS TO GRADUALLY WORK EAST AND NORTHEAST OF OUR AREA
BY MID MORNING BEFORE NEXT POTENTIAL ROUND SETS UP IN THE AFTERNOON.
UPPER TROUGH/LOW IS EXPECTED TO EJECT NORTHEAST INTO THE PLAINS ON
THURSDAY...REACHING THE DAKOTAS BY LATE AFTERNOON. MEANWHILE
TRAILING SURFACE COLD FRONT WILL BE MARCHING EAST INTO EASTERN
NEBRASKA IN THE AFTERNOON. VARYING MODEL TIMING OF THIS FEATURE IS
STILL APPARENT...BUT WERE BETTER IN LINE SHOWING BEST CONVECTIVE
CHANCES NEAR AND EAST OF THE MISSOURI RIVER AT TIME OF MAX HEATING
AND INSTABILITY. EXPECT STORMS TO FIRE ALONG COLD FRONT FROM WEST
CENTRAL IOWA INTO SOUTHEAST NEBRASKA BY MID/LATE AFTERNOON WHERE
SURFACE-BASED CAPES WILL EXCEED 2000 J/KG AND CLOSE TO 50KT OF 0-6KM
BULK SHEAR WILL RESIDE. HAIL AND DAMAGING WINDS WILL CERTAINLY BE
POSSIBLE WHERE STORMS DO FIRE. STORMS WILL RACE NORTHEAST AS FRONT
PUSHES EAST...SO EXPECT MOST CONVECTION TO BE WELL EAST OF OUR AREA
BY MID EVENING. SOME LINGERING STORMS WILL BE POSSIBLE IN FAR
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA WHERE FRONT WILL BE SLOWER TO
CLEAR THOSE AREAS. SOME WRAP-AROUND SHOWERS ARE ALSO POSSIBLE IN
NORTHEAST NEBRASKA THURSDAY EVENING.
FRIDAY LOOKS DRY AND COOLER BEHIND EXITING FRONT...WITH HIGHS FROM
THE UPPER 60S TO LOWER 70S. A QUICK RETURN TO SOUTHERLY LOW LEVEL
FLOW DEVELOPS FRIDAY NIGHT AS A TRAILING UPPER WAVE INDUCES SURFACE
LOW PRESSURE IN THE HIGH PLAINS. AS WAVE TRACKS EAST ON
SATURDAY...SURFACE FRONT WILL ENTER NORTHEAST NEBRASKA IN THE
MORNING...THEN INTO NORTHERN KANSAS AND MISSOURI SATURDAY EVENING.
SHOWERS AND SOME THUNDERSTORMS WILL BE POSSIBLE WITH THIS FRONT
THROUGH THE DAY SATURDAY...WITH TEMPERATURES REMAINING GENERALLY IN
THE 70S.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 352 PM CDT WED MAY 7 2014
A STRONGER MID LEVEL TROUGH IS FORECAST TO SETTLE INTO THE ROCKIES
BY SUNDAY...THEN PROGRESS INTO THE PLAINS MONDAY AND TUESDAY OF NEXT
WEEK. TIMING DIFFERENCES ABOUND BETWEEN GFS/ECMWF AND THEIR ENSEMBLE
MEMBERS...BUT ALL POINT TO AN UNSETTLED WEATHER PATTERN AND CHANCES
FOR PRECIPITATION AT LEAST INTO MONDAY NIGHT. EXPECT MORE OF AN
OVERRUNNING-TYPE SCENARIO FOR OUR AREA AS FRONTAL BOUNDARY REMAIN TO
OUR SOUTH FOCUSING CONVECTION ACROSS KANSAS AND MISSOURI. ECMWF HAS
TRENDED TOWARD GFS SOLUTION IN THIS REGARD. SO HAVE AT LEAST CHANCE
POPS FOR RAIN/SHOWERS ACROSS A GOOD PART OF THE AREA SATURDAY NIGHT
INTO MONDAY NIGHT.
BEYOND MONDAY NIGHT...EXPECT NORTHWEST FLOW ALOFT TO RULE INTO
WEDNESDAY. A SHORTWAVE OR TWO COULD BRING ISOLATED PRECIP CHANCES
DURING THIS TIME...BUT MAIN STORY WILL BE COOLER TEMPERATURES WITH
HIGHS GENERALLY IN THE 60S.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 116 PM CDT WED MAY 7 2014
SURFACE LOW WAS LOCATED OVER EAST CENTRAL NEBRASKA AT 18Z WITH
WARM FRONT BEGINNING TO PIVOT NORTHWEST INTO NORTHEAST NEBRASKA.
THIS BOUNDARY IS EXPECTED TO REMAIN ACROSS THE AREA THROUGH
THURSDAY MORNING AS A SECONDARY SURFACE WAVE LIFTS NORTHEAST
OUT OF COLORADO TOWARDS SOUTHWEST MINNESOTA THURSDAY AFTERNOON.
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD AT BOTH KLNK AND
KOMA AS THEY REMAIN IN THE WARM SECTOR...WHILE MORE VARIABLE
CONDITIONS LIKELY AT KOFK WITH A PERIOD OF MVFR CIGS AND VSBY
03Z-12Z AS SHOWERS AND THUNDERSTORMS DEVELOP ON THE NORTH SIDE OF
THE FRONTAL BOUNDARY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING UNTIL 8 PM CDT THIS EVENING FOR NEZ050-051-
065>068-078-088>090.
IA...NONE.
&&
$$
SHORT TERM...DERGAN
LONG TERM...DERGAN
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS HASTINGS NE
353 PM CDT WED MAY 7 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 333 PM CDT WED MAY 7 2014
MAP ANALYSIS INDICATES AN UPPER TROPOSPHERIC LONGWAVE TROUGH AXIS
NEARING THE ROCKY MOUNTAIN RANGE...AND A RIDGE OVER THE EASTERN
CONUS. A CLOSED UPPER TROPOSPHERIC LOW IS ALSO NOTED EMBEDDED
WITHIN THE LONGWAVE TROUGH AXIS. ENHANCED UPPER TROPOSPHERIC JET
ENERGY EXTENDS SOUTH ALONG THE WESTERN CONUS COAST. THIS ENHANCED
FLOW THEN SPLITS INTO TWO BRANCHES...WITH ONE BRANCH EXTENDING
EAST ACROSS THE SOUTHERN CONUS...AND ANOTHER EXTENDING NORTHEAST
INTO THE PLAINS AND THEN EAST/SOUTHEAST OVER THE GREAT LAKES
REGION AND INTO THE NORTHEASTERN CONUS. UPPER TROPOSPHERIC FLOW
OVER OUR AREA MAXES OUT AT AROUND 55KTS NEAR 36000FT AGL PER 12Z
SOUNDING DATA FROM KLBF AND KOAX. WATER VAPOR IMAGERY SHOWS THE
AFOREMENTIONED LONGWAVE TROUGH AXIS AND RIDGE AXIS. WATER VAPOR
IMAGERY ALSO SHOWS INCREASED UPPER TROPOSPHERIC MOISTURE EXTENDING
FROM THE FOUR CORNERS REGION INTO THE CENTRAL HIGH PLAINS...AS
WELL AS FROM SOUTHERN TEXAS INTO THE MID-MISSISSIPPI VALLEY. AN
UPPER TROPOSPHERIC DRY INTRUSION IS NOTED MOVING FROM WEST-TEXAS
INTO THE SOUTHERN AND CENTRAL PLAINS. AT THE SURFACE AN AREA OF
LOW BAROMETRIC PRESSURE IS NOTED OVER WESTERN KANSAS AND EASTERN
COLORADO...WITH A WARM FRONT EXTENDING FROM THE LOW NORTHEASTWARD
INTO CENTRAL AND EAST-CENTRAL NEBRASKA. ANOTHER AREA OF LOW
BAROMETRIC PRESSURE IS NOTED STRENGTHENING ALONG THE LOWER
TROPOSPHERIC BAROCLINIC ZONE OVER EAST-CENTRAL NEBRASKA. A DRY
LINE IS NOTED EXTENDING SOUTH/SOUTHWEST FROM THIS SECONDARY LOW
AND AS OF 20Z WAS NOTED FROM NEAR KBIE...TO NEAR KCNK...TO NEAR
KGBD. THE RESULTANT LOWER TROPOSPHERIC WIND FIELD ACROSS OUR AREA
REMAINS FROM THE NORTH/NORTHEAST ACROSS OUR NORTH/NORTHWESTERN
CWA...WHILE LOCATIONS FARTHER SOUTH/SOUTHEAST...SOUTH OF THE WARM
FRONT AND BEHIND THE DRY LINE...HAS TURNED MORE SOUTHWESTERLY.
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL
SUGGEST THE WESTERN CONUS UPPER TROPOSPHERIC LONGWAVE TROUGH WILL
MOVE EAST...WITH THE EMBEDDED CLOSED LOW WEAKENING INTO AN OPEN
WAVE AND MOVING EAST/NORTHEAST...AS A NEGATIVELY-TILTED SHORT
WAVE...FROM THE CENTRAL HIGH PLAINS INTO PORTIONS OF THE NORTHERN
PLAINS THROUGH THE NEXT 24 HOURS. THE AREA OF LOW BAROMETRIC
PRESSURE AT THE SURFACE OVER WESTERN KANSAS IS EXPECTED TO MOVE
NORTHEAST INTO CENTRAL NEBRASKA BY 12Z THURSDAY...AND INTO
SOUTHWESTERN MINNESOTA BY 00Z FRIDAY. AS THE SURFACE LOW MOVES
INTO CENTRAL NEBRASKA...THE LOWER TROPOSPHERIC WIND FIELD ACROSS
OUR AREA SHOULD BECOME MORE SOUTH/SOUTHWESTERLY TONIGHT...BEFORE
BECOMING MORE NORTHWESTERLY DURING THE DAY THURSDAY AS AN
ASSOCIATED LOWER TROPOSPHERIC BAROCLINIC ZONE CLEARS THE AREA.
THE AFOREMENTIONED UPPER TROPOSPHERIC SHORT WAVE IS EXPECTED TO
REMAIN WEST/NORTHWEST OF OUR AREA TONIGHT INTO TOMORROW...THUS
KEEPING THE VAST MAJORITY OF RESULTANT OMEGA TO OUR NORTHWEST AS
WELL. AS A RESULT...PRECIPITATION PRODUCTION IS ALSO EXPECTED TO
REMAIN NORTHWEST OF OUR AREA THIS AFTERNOON INTO THIS EVENING...A
SOLUTION SUPPORTED BY QPF FIELDS FROM THE NAM...OPERATIONAL
GFS...EC...SREF-MEAN...AS WELL AS SIMULATED REFLECTIVITY FROM THE
HRRR...1KM WRF-ARW...1KM WRF-NMM AND 4KM WRF-NMM. THAT BEING
SAID...THERE ARE INDICATIONS FROM SOME SIMULATED REFLECTIVITY
OUTPUT THAT SOME OF THE HIGH PLAINS CONVECTION COULD BRUSH OUR FAR
WESTERN CWA BETWEEN 23Z AND 02Z. ALTHOUGH THE EVENING SHIFT WILL
WANT TO MONITOR HIGH PLAINS CONVECTION IN CASE IT TRIES TO MAKE A
PUSH EAST INTO OUR WESTERN CWA...FOR NOW WILL MAINTAIN A DRY
FORECAST THROUGH THIS EVENING.
IT ALSO WORTH MENTIONING THAT VARIOUS SETS OF GUIDANCE SUGGEST
CONVECTION COULD BE REALIZED THIS AFTERNOON INTO EARLY THIS
EVENING ALONG THE DRY LINE ADVANCING ACROSS THE REGION...BUT SINCE
THIS DRY LINE HAS ALREADY CLEARED OUR AREA ANY RESULTANT
CONVECTION SHOULD REMAIN SOUTH/SOUTHEAST OF OUR AREA...MORE INTO
KANSAS AND SOUTHEASTERN NEBRASKA.
OVERNIGHT TONIGHT...GUIDANCE SUGGESTS A ~60KT JET AXIS JUST ABOVE
THE BOUNDARY LAYER WILL DEVELOP FROM CENTRAL KANSAS INTO PORTIONS
SOUTH CENTRAL NEBRASKA. THERMAL ADVECTION ALONG THIS AXIS AND
MOISTURE CONVERGENCE NEAR THE NOSE OF THIS JET APPEAR AS THOUGH
THEY WILL BE SUFFICIENT FOR PRECIPITATION PRODUCTION ACROSS MUCH
OF THE CWA...A SOLUTION SUPPORTED BY THE NAM...OPERATIONAL GFS
...SREF-MEAN...AS WELL AS SIMULATED REFLECTIVITY FROM THE HRRR AND
1KM WRF-ARW. COVERAGE APPEARS AS THOUGH IT WILL BE SPOTTY AT BEST
AND THUS DID NOT WANT TO GO MUCH HIGHER THAN A 20% POP FOR MUCH OF
THE CWA...AND SUCH HAS BEEN PRESENTED IN THE OFFICIAL FORECAST FOR
THE MOST PART.
THE LOWER TROPOSPHERIC JET AXIS SHOULD WEAKEN TOWARDS DAYBREAK
THURSDAY AS IT MOVES OFF TO THE EAST...THUS ALLOWING FOR
DECREASING POPS ACROSS OUR AREA THURSDAY MORNING. THAT BEING
SAID...THERMAL ADVECTION AHEAD OF THE WESTERN CONUS LONGWAVE
TROUGH AXIS MAY MOVE JUST FAR ENOUGH EAST TO IMPACT EXTREME
WEST/NORTHWEST PORTIONS OF OUR CWA AND AS A RESULT...WENT AHEAD
WITH A ~20% POP ACROSS OUR WEST/NORTHWEST DURING THE DAY THURSDAY.
LOCATIONS ACROSS OUR EXTREME EAST COULD ALSO OBSERVE ISOLATED
CONVECTIVE ACTIVITY BY DURING THE AFTERNOON AS THE AFOREMENTIONED
LOWER TROPOSPHERIC BAROCLINIC ZONE CLEARS THE AREA BEHIND THE
SURFACE LOW. AS A RESULT...ALSO WENT AHEAD WITH A ~20% POP ACROSS
OUR EXTREME EAST FOR THURSDAY AFTERNOON.
FORECAST PROXIMITY SOUNDINGS FROM ACROSS OUR CWA...PER THE NAM
AND OPERATIONAL GFS...SUGGEST PARCELS ROOTED TO AROUND 800MB WILL
HAVE ~1000J/KG OF POTENTIAL ENERGY WITH MINIMAL CIN. DEEP LAYER
BULK SHEAR OF 30-40KTS IS ALSO EXPECTED OVER THE AREA TONIGHT. SO
ALTHOUGH THE THREAT FOR LARGE HAIL DOES NOT SEEM OVERLY
IMPRESSIVE...WILL CONTINUE TO MENTION THE POTENTIAL FOR A STRONG
STORM...WITH HAIL UP TO THE SIZE OF NICKELS...FOR TONIGHT IN THE
HWO. FOR TOMORROW AFTERNOON...LITTLE IF ANY POTENTIAL INSTABILITY
IS EXPECTED TO EXIST OVER OUR WEST/NORTHWESTERN CWA SO WENT AHEAD
WITH NO MENTION OF THUNDER OUT THAT WAY. ACROSS OUR EXTREME EAST
IN THE VICINITY OF THE BAROCLINIC ZONE...THE INTRUSION OF A DRIER
LOWER TROPOSPHERIC AIR MASS WILL LIKELY PREVENT POTENTIAL
INSTABILITY FROM CLIMBING MUCH ABOVE 1000J/KG...ALTHOUGH DEEP
LAYER BULK SHEAR COULD APPROACH 50KTS. WILL GO AHEAD AND MENTION
HAIL TO THE SIZE OF NICKELS ACROSS OUR EXTREME EAST IN THE HWO FOR
THURSDAY AFTERNOON AS A RESULT.
INCREASING SOUTHERLY LOWER TROPOSPHERIC FLOW...ALONG WITH
INCREASED CLOUD COVER AND POTENTIAL PRECIPITATION...SHOULD HELP
PROMOTE ANOTHER WARM NIGHT TONIGHT WITH LOWS IN THE 50S AND 60S
CURRENTLY FORECAST. A COOLER LOWER TROPOSPHERIC AIR MASS WILL WORK
INTO THE AREA BEHIND THE BAROCLINIC ZONE DURING THE DAY
THURSDAY...THUS PROMOTING A COOLER DAY FOR MOST LOCATIONS ON
THURSDAY WHEN COMPARED TO WEDNESDAY. THURSDAY HIGHS IN THE 60S AND
70S ARE CURRENTLY FORECAST FOR MOST LOCATIONS ACROSS THE AREA AS A
RESULT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 333 PM CDT WED MAY 7 2014
ALOFT: MULTI-DAY 500 MB MEANS FROM THE GFS AND EC ENSEMBLES SHOW
THAT THE LONGWAVE TROF WILL BE OVER THE WRN USA THRU MON
5/12...WITH THE RIDGE OVER THE ERN USA. THE LEAD SHORTWAVE TROF
WILL EXIT E OF THE REGION FRI...TEMPORARILY DEAMPLIFYING THE WRN
USA TROF/ERN USA RIDGE. THE LOW CURRENTLY OVER THE GULF OF AK WILL
DROP INTO THE WRN TROF SAT...RESULTING IN RE-AMPLIFICATION SUN-
MON. BY THIS TIME FRAME...THE USUAL MODEL BIASES APPEAR WITH THE
06Z/12Z GFS ON THE FAST SIDE OF THE GUIDANCE ENVELOP...AND THE
00Z/12Z GEM ON THE SLOWEST SIDE. THE LAST 3 RUNS OF THE EC DO
FAVOR THE SLOWER GEM. EVEN THE LAST 3 RUNS OF THE UKMET COINCIDE
WITH THE GEM. THAT IS GOOD NEWS FOR RAINFALL. THIS RENEWED TROF
WILL ADVANCE INTO THE PLAINS TUE AND THEN INTO THE ERN USA WED-FRI
WITH NW FLOW DEVELOPING HERE.
THE TROF MOVING INTO THE W SAT LOOKS LIKE IT WILL SEND A
SHORTWAVE TROF E INTO THE NRN PLAINS WHILE THE REST OF THE ENERGY
DROPS INTO THE INTERMOUNTAIN WEST.
SURFACE: NRN PLAINS HIGH PRES WILL SLIP S INTO THE REGION THU
NIGHT WITH THE COOL FRONT DEPARTING FURTHER TO THE S AND E. A NEW
LEE SIDE TROF WILL DEVELOP FRI...WITH AN OCCLUDED LOW ADVANCING
THRU THE NRN PLAINS FRI-SAT /ASSOCIATED WITH THE TROF MENTIONED IN
THE PREVIOUS PARAGRAPH/. THE COOL FRONT WILL MOVE THRU HERE FRI
NIGHT. THAT FRONT WILL THEN BECOME STATIONARY FROM THE SRN PLAINS
TO THE GREAT LAKES SUN AS HEIGHTS FALL IN THE W...AND CYCLOGENESIS
COMMENCES. THIS LOW WILL TRACK UP THE FRONT...ACROSS KANSAS CITY
MON MORNING...AND SHOULD BE OVER IL BY 00Z/TUE BASED ON THE 00Z EC
ENSEMBLE MEAN. EXPANSIVE HIGH PRES WILL ENVELOP THE PLAINS TUE-
WED.
AS FAR AS SENSIBLE WX...THIS MEANS TEMPS WILL AVERAGE COOLER THAN
NORMAL FRI-WED...WITH VERY HIGH POTENTIAL FOR AT LEAST 1 DAY OF
MUCH COOLER THAN NORMAL TEMPS. RIGHT NOW IT/S MON. ANOTHER VERY
GOOD ASPECT OF THIS SYSTEM IS THAT THE EXITING COOL FRONT WILL NOT
PLUNGE DEEP INTO THE S. GULF MOISTURE WILL NOT BE FAR AWAY. THE
LOW WILL ALSO BE TRACKING S OF THE FCST AREA. THIS COULD RESULT IN
BENEFICIAL/SOAKING RAIN FOR PARTS OF THE FCST AREA. THIS REALLY
ISNT MODELED YET...BUT THE PATTERN LOOKS FAVORABLE WITH THE FRONT
HAVING ANABATIC CHARACTER.
THE 16Z WPC EXTENDED FCST DISCUSSION WAS REVIEWED.
HAZARDS: TSTMS ARE POSSIBLE SAT NIGHT INTO SUN S-SE OF THE TRI-
CITIES. DOESNT CURRENTLY LOOK FAVORABLE FOR SEVERE. THERE IS A LOW
PROBABILITY THAT WE MAY NEED A WIND ADVISORY SOMETIME SUN-MON.
THE DAILY DETAILS...
FRI: CLEARING AS A SHORTWAVE RIDGE MOVES IN DURING THE AFTERNOON.
VERY NICE WITH LIGHT WINDS AND NEAR NORMAL TEMPS.
FRI NIGHT: INCREASING MID-HIGH CLOUDS AS THE NEGATIVE TILT NRN
PLAINS TROF MOVES THRU ALONG WITH THE EXIT REGION OF A 100 KT
TROPOPAUSE JET.
A SLIGHT CHANCE OF WARM ADVECTION-INDUCED SPRINKLES HAS BEEN
INTRODUCED INTO THE FCST PRIMARILY ALONG AND N OF I-80. CLOUD
BASES WILL BE NO LOWER THAN 10K FT. SO IT WILL BE TOUGH TO GET
MEASURABLE RAIN.
SAT: MORNING COOL FRONTAL PASSAGE. THE CHANCE OF MORNING
SHWRS/TSTMS WAS WITHDRAWN FROM THE FCST AND REPLACED WITH A SLIGHT
CHANCE OF SPRINKLES N AND E OF THE TRI-CITIES. THEN CLEARING AND A
LITTLE WARMER.
SAT NIGHT: A 50 KT LOW-LEVEL JET /LLJ/ WILL INDUCE STRONG
WARM/MOIST AIR ADVECTION AND FRONTOGENESIS. THIS WILL RESULT IN
MCS DEVELOPMENT BUT WITH THE LLJ VEERING THRU THE NIGHT...IT IS
LIKELY TO BE E OF THE FCST AREA.
SUN-MON: LOTS OF DETAILS LEFT TO BE DETERMINED. BELIEVE ODDS ARE
VERY HIGH OUR CURRENT HIGH TEMPS ARE WAY TOO WARM BOTH DAYS. WE
ARE BASICALLY CARRYING 60-70F. CONSENSUS OF MODEL 2M TEMPS SUGGEST
50S AND THIS LOOKS MUCH MORE REASONABLE. THIS WILL OCCUR WITH
BLUSTERY N WINDS.
THE BEST CHANCE FOR RAIN IS CURRENTLY SLATED FOR SUN NIGHT INTO
MON MORNING...BUT THIS IS ONLY AVERAGE CONFIDENCE DUE TO MODEL
DISAGREEMENT.
TUE: DRY WITH NEAR NORMAL TEMPS. NW FLOW ALOFT.
WED: NW FLOW MAY DELIVER A WEAK SHORTWAVE TROF...POSSIBLY
RESULTING IN A FEW LIGHT SHWRS OR SPRINKLES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 132 PM CDT WED MAY 7 2014
VFR CONDITIONS EXPECTED UNTIL 03Z...MVFR CONDITIONS FORECAST
03-14Z...AND THEN VFR CONDITIONS TO FINISH THE FORECAST PERIOD.
PERIODIC CLOUD COVER NEAR 4000FT AGL WILL REMAIN POSSIBLE THIS
AFTERNOON INTO TONIGHT. THE DEVELOPMENT OF A ~60KT JET AXIS JUST
ABOVE THE BOUNDARY LAYER ACROSS PORTIONS OF NORTH CENTRAL KANSAS
AND PERHAPS SOUTH CENTRAL NEBRASKA MAY RESULT IN THE DEVELOPMENT
OF STRATUS TONIGHT...WITH MULTIPLE SETS OF GUIDANCE SUGGESTING
THIS STRATUS WILL IMPACT GRI. GUIDANCE SUGGESTS A CEILING NEAR
2000FT AGL COULD RESULT AND ALTHOUGH CONFIDENCE IS NOT
PARTICULARLY HIGH REGARDING THIS STRATUS...WITH MULTIPLE SETS OF
GUIDANCE SUGGESTING SUCH CONDITIONS FELT IT PRUDENT TO INTRODUCE
MVFR CONDITIONS TO THE TAF AND LET FUTURE SHIFTS ADJUST AS
NECESSARY. THERMAL ADVECTION AND MOISTURE CONVERGENCE NEAR THE
NOSE OF THE AFOREMENTIONED JET AXIS COULD ALSO PROMOTE ISOLATED
PRECIPITATION PRODUCTION NEAR GRI TONIGHT...WITH CONVECTIVE
ACTIVITY ALSO NOT OUT OF THE QUESTION. WENT AHEAD WITH VCTS 08-14Z
AS A RESULT. INCREASED DIABATIC HEATING AND INCREASING BOUNDARY
LAYER HEIGHT AND MIXING POST-SUNRISE ON THURSDAY SHOULD DIMINISH
ANY STRATUS THAT IS REALIZED...THUS THE VFR CONDITIONS WHICH ARE
FORECAST 14Z ONWARD IN THE TAF. THE SURFACE WIND WILL REMAIN
FAIRLY LIGHT AND AT TIMES VARIABLE THIS AFTERNOON INTO
TONIGHT...BUT WILL BECOME MORE ESTABLISHED FROM THE SOUTH OR
SOUTHWEST DURING THE DAY THURSDAY. THE WEAK LOWER TROPOSPHERIC
WIND FIELD...ALONG WITH NEAR-ZERO LOWER TROPOSPHERIC DEW POINT
DEPRESSIONS...COULD ALSO RESULT IN PATCHY FOG TONIGHT AT
GRI...THUS 5SM IN BR HAS BEEN INTRODUCED INTO THE TAF 08-14Z.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR NEZ049-063-064-
074>077-083>087.
KS...RED FLAG WARNING UNTIL 9 PM CDT THIS EVENING FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...BRYANT
LONG TERM...HALBLAUB
AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1250 PM CDT WED MAY 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT WED MAY 7 2014
ISOLATED ELEVATED STRONG TO SEVERE THUNDERSTORMS ARE ONGOING THIS
MORNING. THE HRRR AND RAP REALLY ARE NOT HANDLING THE STORM TRACK AS
THESE METEOROLOGICAL CHALLENGED MODELS PREFER TO TRACK THE
ACTIVITY MORE NORTHEAST THROUGH NORTHWEST NEB VS THE WRN SANDHILLS.
THIS LIKELY A RESULT OF THE STORM(S) BECOMING ROOTED IN THE LOW
LEVEL EASTERLIES. AT ANY RATE THE CURRENT THINKING IS THE STORMS
WILL EITHER WEAKEN BEFORE 12Z OR CONTINUE TRACKING TOWARD SCNTL SD.
A BLEND OF THE NAM...RAP...ECM...SREF AND THE PREVIOUS FORECAST
SUGGESTED SCATTERED POPS THIS MORNING BECOMING LIKELY THIS
AFTERNOON. THE RAP HAS ANALYZED A CLOSED H700MB LOW OVER NORTHEAST
COLO AT 07Z WHICH LIFTS NORTHEAST THROUGH NWRN NEB THIS MORNING TO
FOLLOWED BY A SECOND AND THIRD H7 WAVES THIS AFTERNOON AND EARLY
THIS EVENING.
THIS WOULD LIKELY KEEP THE WARM SECTOR FROM KIML TO KONL AND SOUTH
DRY TODAY. THE NAM SUGGESTS SOME CONVECTION COULD DEVELOP OFF THE
FRONT RANGE THIS AFTN AND SWEEP NORTHEAST THROUGH THE SRN AND NERN
ZONES. THE THREAT OF SEVERE WEATHER IS OBVIOUS WITH BULK SHEAR 50
KTS OR GREATER AND STEEPENING LAPSE RATES WITH THE APPROACHING 4
CORNERS LOW. SPC HATCHED AN EGG OF VERY LARGE HAIL ACROSS THE WRN
SANDHILLS AND PANHANDLE. THIS IS ALONG AND NORTH OF SFC FRONT WHICH
IS EXPECTED TO LIFT THROUGH SRN AND NERN NEB LATE THIS AFTN. VERY
LARGE HAIL IS POSSIBLE WITH STORMS THIS AFTERNOON AND EVENING AND
MOST IF NOT ALL OF THIS SHOULD BE IN THE COLD AIR NORTH OF THE SFC
FRONT. THE 5 PERCENT TORNADO AND 15 PERCENT WIND PROBABILITIES WOULD
APPEAR CONDITIONALLY TIED TO STORMS FORMING ALONG THE SFC FRONT
WHICH LIFTS NORTH OF I-80 AROUND 21Z THIS AFTN AND THEN DROPS BACK
SOUTH.
SEVERE WEATHER CONTINUES THIS EVENING...PRESUMABLY ELEVATED...WITH
THE APPROACH OF THE MAIN UPPER LEVEL LOW. THE NAM AND OTHER MODELS
LIFT A DECENT SHOT OF PV15 THROUGH THE FCST AREA. MEANWHILE...LATE
SEASON ARCTIC AIR...CURRENTLY IN MONTANA DROPS THROUGH THE HIGH
PLAINS FOR A ZONE OF THUNDERSTORMS CHANGING TO WET HEAVY SNOW. THE
NAM BACKS THE ELEVATED INSTABILITY RIGHT UP AGAINST THE RAIN SNOW
LINE ACROSS SHERIDAN COUNTY AROUND 09Z. THIS MIGHT BE TOO SLOW GIVEN
THE PROXIMITY OF THE COLD AIR ACROSS MT AND THE RAIN SNOW LINE OVER
NERN WY. THE RAP CAN FIGURE THIS OUT LATER TODAY.
FOR NOW THE RAP HAS THE H700MB FREEZING LINE MOVING THROUGH SERN WY
AT 00Z THIS EVENING SO A QUICKER CHANGE TO SNOW IS POSSIBLE. THE
BEST GUESS ON SNOW AMOUNTS USES THE NAM...GEMREG...SREF AND ECM FOR
QPF WITH A 5 OT 1 RATIO FOR UP TO 4 INCHES IN NORTHERN SHERIDAN
COUNTY THROUGH 12Z THURSDAY MORNING. LOCALLY HIGHER AMOUNTS COULD
DEVELOP ESPECIALLY IF THE CHANGE OVER OCCURS AT 06Z VS THE NAM MODEL
SHOWING 09Z. THE RAP HAS BEEN THE BEST PERFORMER THIS SPRING IN RAIN
SNOW EVENTS FOLLOWED THE NAM.
A WINTER WEATHER ADVISORY IS IN PLACE FOR SHERIDAN COUNTY 09Z-15Z
TONIGHT THROUGH THURSDAY MORNING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 335 AM CDT WED MAY 7 2014
LARGE UPPER LEVEL TROUGH WILL CONTINUE TO SHIFT EAST NORTHEAST
ACROSS THE CENTRAL PLAINS ON THURSDAY...REACHING THE NORTHERN
MISSOURI VALLEY EARLY FRIDAY. IN THE WAKE OF THE UPPER TROUGH
...QUASI-ZONAL FLOW WILL PREVAIL THROUGH MUCH OF THE WEEKEND...BUT
EVENTUALLY BREAK DOWN WITH THE APPROACH OF THE NEXT APPRECIABLE
WESTERN STATES UPPER TROUGH. THE SURFACE PATTERN FAVORS A
NORTHEASTWARD ADVANCING LOW TOWARD MINNESOTA AND FINALLY INTO
SOUTHWEST ONTARIO BY EARLY FRIDAY. THIS LOW WILL DRAG A FRONT
THROUGH THE CWA LEAVING POST FRONTAL CONDITIONS INTO EARLY
FRIDAY...BUT THE LOWER TROPOSPHERIC FLOW WILL RETURN TO SOUTHERLY
AS A LEE TROUGH DEVELOPS OFF THE HIGH PLAINS FRIDAY WITH THE
APPROACH OF A WEAK NORTHERN PLAINS UPPER WAVE. THIS WAVE...AS IT/S
PREDECESSOR...WILL DRAG AN ADDITIONAL FRONT THROUGH THE CWA ON
SATURDAY. THE SATURDAY BAROCLINIC ZONE IS FORECAST TO BE
WEAK...WITH LITTLE TO NO SENSIBLE CHANGES ANTICIPATED.
FOR THURSDAY...WINTER WEATHER ADVISORY ACROSS SHERIDAN COUNTY WILL
CONTINUE UNTIL 15Z. ALL THE MEDIUM RANGE DETERMINISTIC MODELS HAVE
CONVERGED SOMEWHAT ON A SOLUTION FOR WHICH THERMAL PROFILES WOULD
SUPPORT SNOW ACROSS SHERIDAN COUNTY. THERMAL PROFILES INDICATE A
DEEP SATURATION...AT TIMES EXTENDING INTO THE DGZ...BUT WARM GROUND
TEMPERATURES AND SFC T/S NEAR OR SLIGHTLY ABOVE 0C CREATE LOW
CONFIDENCE FORECAST CONCERNING ACCUMULATIONS. SINCE A STRONG
DEFORMATION ZONE IS SHOWN TO SET UP IN THIS AREA...CO-LOCATED IN THE
TROWAL REGION OF THE SYSTEM...SNOW RATES MAY BE SUFFICIENT TO
OVERCOME THE HIGH SUN ANGLE AND WARM TEMPERATURES...BUT CONFIDENCE
IS NOT ENOUGH TO EXPIRE THE ADVISORY BEFORE 15Z.
CONSEQUENTLY...GIVEN THE STRENGTH OF THE DEFORMATION...SNOW RATES
MAY BE SUFFICIENT TO ALLOW FOR SLUSH ACCUMULATION PAST 15Z THURSDAY.
FORECAST TIMING WITH THE CURRENT WINTER WEATHER ADVISORY MAY CHANGE
WITH NEAR TERM GUIDANCE.
WITH LOW LEVEL CAA ONGOING...HIGH TEMPERATURES THURSDAY WILL BE
CHILLY...40S FOR THE NORTHWEST...POSSIBLY SOME 60S SOUTHEAST. WILL
NEED TO MONITOR CLOUDS THURSDAY NIGHT AND FRIDAY MORNING AS ANY
CLEARING WOULD LEAD TO SUB 0C LOWS...WITH THE THREAT OF A LIGHT
FREEZE. ATTM...FAVORING THE ECMWF SOLUTION WHICH IS ON SLOWER
SIDE...KEEPING SUFFICIENT CLOUDS ACROSS MUCH OF THE FORECAST AREA
TO PREVENT A WIDESPREAD FREEZE. ATTM...NORTHWEST NEBRASKA WOULD
HAVE THE HIGHEST POTENTIAL OF SEEING A DAMAGING FREEZE /TO YOUNG
PLANTS/...ESPECIALLY IF SNOW TOTALS ARE HIGHER THAN CURRENTLY
ANTICIPATED. THE ENTIRE NORTH PLATTE CWA HAS NOT REACHED THE 50
PERCENTILE FOR LAST FREEZE DATE...WE DO NOT PLAN TO FROST/FREEZE
HEADLINES ATTM.
FRIDAY...WITH RETURN FLOW DIRECTING WAA BACK INTO THE
CWA...TEMPERATURES SHOULD WARM BACK WELL INTO THE 60S...POSSIBLY
LOWER 70S FOR THE ENTIRE CWA. BUT A FAST MOVING WAVE PASSING
THROUGH THE QUASI-ZONAL FLOW MAY SPARK OFF A SHOWER OR TWO DURING
THE EVENING AND EARLY ON SATURDAY...WITH A WEAK WIND SHIFT TO
FOLLOW. AGAIN SATURDAY TEMPERATURES WON/T BE TOO FAR OFF FROM
CLIMO...GENERALLY HIGHS IN THE 60S TO LOWER 70S CAN BE EXPECTED FOR
MOST IF NOT ALL LOCATIONS. LATE WEEKEND INTO EARLY NEXT
WEEK...ANOTHER SYSTEM LOOKS TO MOVE INTO THE CENTRAL ROCKIES
SATURDAY NIGHT AND EMERGE ONTO THE PLAINS SUNDAY AND MONDAY.
WIDESPREAD PRECIPITATION WILL BE POSSIBLE...AND DESPITE DIFFERENCES
WITH THE HANDLING OF THE SYSTEM...WILL MAINTAIN 30-40 POPS LATE
WEEKEND INTO EARLY NEXT WEEK FOR MUCH OF THE CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1249 PM CDT WED MAY 7 2014
COMPLEX STORM SYSTEM TO BRING AN ARRAY OF WEATHER TO THE AREA THIS
AFTERNOON THROUGH TOMORROW MORNING. THUNDERSTORMS ARE EXPECTED TO
DEVELOP THIS AFTERNOON AND LIFT TO THE NORTHEAST ACROSS THE AREA.
THESE STORMS COULD PRODUCE SOME LARGE HAIL AND DAMAGING WINDS. DID
INCLUDE TSRA AT KLBF...HOWEVER KLBF LIKELY TO BE ON THE EAST SIDE
OF THE ACTIVITY. HIGHER CONFIDENCE KVTN WILL SEE AN IMPACT FROM
THUNDERSTORMS. THEN A COLD FRONT WILL PUSH ACROSS THE AREA WITH
MVFR CIGS...POSSIBLY IFR CIGS...BEHIND THE FRONT. WINDS INCREASE
BEHIND THE FRONT AND NORTHERN NEB...INCLUDING THE KVTN AREA...WILL
SEE RAIN SHOWERS. FAR NORTHWEST NEBRASKA COULD SEE SOME SNOW LATE
TONIGHT INTO TOMORROW MORNING. CONDITIONS IMPROVE TOMORROW
MORNING...ESPECIALLY IN THE SOUTHWEST PART OF NEBRASKA.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 AM TO 9 AM MDT THURSDAY FOR
NEZ004.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...MASEK
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
633 AM CDT WED MAY 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT WED MAY 7 2014
ISOLATED ELEVATED STRONG TO SEVERE THUNDERSTORMS ARE ONGOING THIS
MORNING. THE HRRR AND RAP REALLY ARE NOT HANDLING THE STORM TRACK AS
THESE METEOROLOGICAL CHALLENGED MODELS PREFER TO TRACK THE
ACTIVITY MORE NORTHEAST THROUGH NORTHWEST NEB VS THE WRN SANDHILLS.
THIS LIKELY A RESULT OF THE STORM(S) BECOMING ROOTED IN THE LOW
LEVEL EASTERLIES. AT ANY RATE THE CURRENT THINKING IS THE STORMS
WILL EITHER WEAKEN BEFORE 12Z OR CONTINUE TRACKING TOWARD SCNTL SD.
A BLEND OF THE NAM...RAP...ECM...SREF AND THE PREVIOUS FORECAST
SUGGESTED SCATTERED POPS THIS MORNING BECOMING LIKELY THIS
AFTERNOON. THE RAP HAS ANALYZED A CLOSED H700MB LOW OVER NORTHEAST
COLO AT 07Z WHICH LIFTS NORTHEAST THROUGH NWRN NEB THIS MORNING TO
FOLLOWED BY A SECOND AND THIRD H7 WAVES THIS AFTERNOON AND EARLY
THIS EVENING.
THIS WOULD LIKELY KEEP THE WARM SECTOR FROM KIML TO KONL AND SOUTH
DRY TODAY. THE NAM SUGGESTS SOME CONVECTION COULD DEVELOP OFF THE
FRONT RANGE THIS AFTN AND SWEEP NORTHEAST THROUGH THE SRN AND NERN
ZONES. THE THREAT OF SEVERE WEATHER IS OBVIOUS WITH BULK SHEAR 50
KTS OR GREATER AND STEEPENING LAPSE RATES WITH THE APPROACHING 4
CORNERS LOW. SPC HATCHED AN EGG OF VERY LARGE HAIL ACROSS THE WRN
SANDHILLS AND PANHANDLE. THIS IS ALONG AND NORTH OF SFC FRONT WHICH
IS EXPECTED TO LIFT THROUGH SRN AND NERN NEB LATE THIS AFTN. VERY
LARGE HAIL IS POSSIBLE WITH STORMS THIS AFTERNOON AND EVENING AND
MOST IF NOT ALL OF THIS SHOULD BE IN THE COLD AIR NORTH OF THE SFC
FRONT. THE 5 PERCENT TORNADO AND 15 PERCENT WIND PROBABILITIES WOULD
APPEAR CONDITIONALLY TIED TO STORMS FORMING ALONG THE SFC FRONT
WHICH LIFTS NORTH OF I-80 AROUND 21Z THIS AFTN AND THEN DROPS BACK
SOUTH.
SEVERE WEATHER CONTINUES THIS EVENING...PRESUMABLY ELEVATED...WITH
THE APPROACH OF THE MAIN UPPER LEVEL LOW. THE NAM AND OTHER MODELS
LIFT A DECENT SHOT OF PV15 THROUGH THE FCST AREA. MEANWHILE...LATE
SEASON ARCTIC AIR...CURRENTLY IN MONTANA DROPS THROUGH THE HIGH
PLAINS FOR A ZONE OF THUNDERSTORMS CHANGING TO WET HEAVY SNOW. THE
NAM BACKS THE ELEVATED INSTABILITY RIGHT UP AGAINST THE RAIN SNOW
LINE ACROSS SHERIDAN COUNTY AROUND 09Z. THIS MIGHT BE TOO SLOW GIVEN
THE PROXIMITY OF THE COLD AIR ACROSS MT AND THE RAIN SNOW LINE OVER
NERN WY. THE RAP CAN FIGURE THIS OUT LATER TODAY.
FOR NOW THE RAP HAS THE H700MB FREEZING LINE MOVING THROUGH SERN WY
AT 00Z THIS EVENING SO A QUICKER CHANGE TO SNOW IS POSSIBLE. THE
BEST GUESS ON SNOW AMOUNTS USES THE NAM...GEMREG...SREF AND ECM FOR
QPF WITH A 5 OT 1 RATIO FOR UP TO 4 INCHES IN NORTHERN SHERIDAN
COUNTY THROUGH 12Z THURSDAY MORING. LOCALLY HIGHER AMOUNTS COULD
DEVELOP ESPECIALLY IF THE CHANGE OVER OCCURS AT 06Z VS THE NAM MODEL
SHOWING 09Z. THE RAP HAS BEEN THE BEST PERFORMER THIS SPRING IN RAIN
SNOW EVENTS FOLLOWED THE NAM.
A WINTER WEATHER ADVISORY IS IN PLACE FOR SHERIDAN COUNTY 09Z-15Z
TONIGHT THROUGH THURSDAY MORNING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 335 AM CDT WED MAY 7 2014
LARGE UPPER LEVEL TROUGH WILL CONTINUE TO SHIFT EAST NORTHEAST
ACROSS THE CENTRAL PLAINS ON THURSDAY...REACHING THE NORTHERN
MISSOURI VALLEY EARLY FRIDAY. IN THE WAKE OF THE UPPER TROUGH
...QUASI-ZONAL FLOW WILL PREVAIL THROUGH MUCH OF THE WEEKEND...BUT
EVENTUALLY BREAK DOWN WITH THE APPROACH OF THE NEXT APPRECIABLE
WESTERN STATES UPPER TROUGH. THE SURFACE PATTERN FAVORS A
NORTHEASTWARD ADVANCING LOW TOWARD MINNESOTA AND FINALLY INTO
SOUTHWEST ONTARIO BY EARLY FRIDAY. THIS LOW WILL DRAG A FRONT
THROUGH THE CWA LEAVING POST FRONTAL CONDITIONS INTO EARLY
FRIDAY...BUT THE LOWER TROPOSPHERIC FLOW WILL RETURN TO SOUTHERLY
AS A LEE TROUGH DEVELOPS OFF THE HIGH PLAINS FRIDAY WITH THE
APPROACH OF A WEAK NORTHERN PLAINS UPPER WAVE. THIS WAVE...AS IT/S
PREDECESSOR...WILL DRAG AN ADDITIONAL FRONT THROUGH THE CWA ON
SATURDAY. THE SATURDAY BAROCLINIC ZONE IS FORECAST TO BE
WEAK...WITH LITTLE TO NO SENSIBLE CHANGES ANTICIPATED.
FOR THURSDAY...WINTER WEATHER ADVISORY ACROSS SHERIDAN COUNTY WILL
CONTINUE UNTIL 15Z. ALL THE MEDIUM RANGE DETERMINISTIC MODELS HAVE
CONVERGED SOMEWHAT ON A SOLUTION FOR WHICH THERMAL PROFILES WOULD
SUPPORT SNOW ACROSS SHERIDAN COUNTY. THERMAL PROFILES INDICATE A
DEEP SATURATION...AT TIMES EXTENDING INTO THE DGZ...BUT WARM GROUND
TEMPERATURES AND SFC T/S NEAR OR SLIGHTLY ABOVE 0C CREATE LOW
CONFIDENCE FORECAST CONCERNING ACCUMULATIONS. SINCE A STRONG
DEFORMATION ZONE IS SHOWN TO SET UP IN THIS AREA...CO-LOCATED IN THE
TROWAL REGION OF THE SYSTEM...SNOW RATES MAY BE SUFFICIENT TO
OVERCOME THE HIGH SUN ANGLE AND WARM TEMPERATURES...BUT CONFIDENCE
IS NOT ENOUGH TO EXPIRE THE ADVISORY BEFORE 15Z.
CONSEQUENTLY...GIVEN THE STRENGTH OF THE DEFORMATION...SNOW RATES
MAY BE SUFFICIENT TO ALLOW FOR SLUSH ACCUMULATION PAST 15Z THURSDAY.
FORECAST TIMING WITH THE CURRENT WINTER WEATHER ADVISORY MAY CHANGE
WITH NEAR TERM GUIDANCE.
WITH LOW LEVEL CAA ONGOING...HIGH TEMPERATURES THURSDAY WILL BE
CHILLY...40S FOR THE NORTHWEST...POSSIBLY SOME 60S SOUTHEAST. WILL
NEED TO MONITOR CLOUDS THURSDAY NIGHT AND FRIDAY MORNING AS ANY
CLEARING WOULD LEAD TO SUB 0C LOWS...WITH THE THREAT OF A LIGHT
FREEZE. ATTM...FAVORING THE ECMWF SOLUTION WHICH IS ON SLOWER
SIDE...KEEPING SUFFICIENT CLOUDS ACROSS MUCH OF THE FORECAST AREA
TO PREVENT A WIDESPREAD FREEZE. ATTM...NORTHWEST NEBRASKA WOULD
HAVE THE HIGHEST POTENTIAL OF SEEING A DAMAGING FREEZE /TO YOUNG
PLANTS/...ESPECIALLY IF SNOW TOTALS ARE HIGHER THAN CURRENTLY
ANTICIPATED. THE ENTIRE NORTH PLATTE CWA HAS NOT REACHED THE 50
PERCENTILE FOR LAST FREEZE DATE...WE DO NOT PLAN TO FROST/FREEZE
HEADLINES ATTM.
FRIDAY...WITH RETURN FLOW DIRECTING WAA BACK INTO THE
CWA...TEMPERATURES SHOULD WARM BACK WELL INTO THE 60S...POSSIBLY
LOWER 70S FOR THE ENTIRE CWA. BUT A FAST MOVING WAVE PASSING
THROUGH THE QUASI-ZONAL FLOW MAY SPARK OFF A SHOWER OR TWO DURING
THE EVENING AND EARLY ON SATURDAY...WITH A WEAK WIND SHIFT TO
FOLLOW. AGAIN SATURDAY TEMPERATURES WON/T BE TOO FAR OFF FROM
CLIMO...GENERALLY HIGHS IN THE 60S TO LOWER 70S CAN BE EXPECTED FOR
MOST IF NOT ALL LOCATIONS. LATE WEEKEND INTO EARLY NEXT
WEEK...ANOTHER SYSTEM LOOKS TO MOVE INTO THE CENTRAL ROCKIES
SATURDAY NIGHT AND EMERGE ONTO THE PLAINS SUNDAY AND MONDAY.
WIDESPREAD PRECIPITATION WILL BE POSSIBLE...AND DESPITE DIFFERENCES
WITH THE HANDLING OF THE SYSTEM...WILL MAINTAIN 30-40 POPS LATE
WEEKEND INTO EARLY NEXT WEEK FOR MUCH OF THE CWA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 632 AM CDT WED MAY 7 2014
MVFR/IFR IN SHOWERS AND SEVERE THUNDERSTORMS TODAY...MAINLY NORTH
AND WEST OF KOGA-KVTN. VFR IS GENERALLY EXPECTED ELSEWHERE.
TONIGHT THIS WEATHER SPREADS EAST TO KIML-KONL. AS THE UPPER
LOW...CURRENTLY OVER WRN UT...LIFTS THROUGH WRN NEB LATE
TONIGHT...MVFR CIGS SHOULD FILL IN SOUTH OF KVTN-KOGA. NOTE NORTH
OF THAT LINE...MVFR/IFR/LOCAL LIFR IN RAIN AND SNOW IS EXPECTED.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 AM TO 9 AM MDT THURSDAY FOR
NEZ004.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
335 AM CDT WED MAY 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT WED MAY 7 2014
ISOLATED ELEVATED STRONG TO SEVERE THUNDERSTORMS ARE ONGOING THIS
MORNING. THE HRRR AND RAP REALLY ARE NOT HANDLING THE STORM TRACK AS
THESE METEOROLOGICAL CHALLENGED MODELS PREFER TO TRACK THE
ACTIVITY MORE NORTHEAST THROUGH NORTHWEST NEB VS THE WRN SANDHILLS.
THIS LIKELY A RESULT OF THE STORM(S) BECOMING ROOTED IN THE LOW
LEVEL EASTERLIES. AT ANY RATE THE CURRENT THINKING IS THE STORMS
WILL EITHER WEAKEN BEFORE 12Z OR CONTINUE TRACKING TOWARD SCNTL SD.
A BLEND OF THE NAM...RAP...ECM...SREF AND THE PREVIOUS FORECAST
SUGGESTED SCATTERED POPS THIS MORNING BECOMING LIKELY THIS
AFTERNOON. THE RAP HAS ANALYZED A CLOSED H700MB LOW OVER NORTHEAST
COLO AT 07Z WHICH LIFTS NORTHEAST THROUGH NWRN NEB THIS MORNING TO
FOLLOWED BY A SECOND AND THIRD H7 WAVES THIS AFTERNOON AND EARLY
THIS EVENING.
THIS WOULD LIKELY KEEP THE WARM SECTOR FROM KIML TO KONL AND SOUTH
DRY TODAY. THE NAM SUGGESTS SOME CONVECTION COULD DEVELOP OFF THE
FRONT RANGE THIS AFTN AND SWEEP NORTHEAST THROUGH THE SRN AND NERN
ZONES. THE THREAT OF SEVERE WEATHER IS OBVIOUS WITH BULK SHEAR 50
KTS OR GREATER AND STEEPENING LAPSE RATES WITH THE APPROACHING 4
CORNERS LOW. SPC HATCHED AN EGG OF VERY LARGE HAIL ACROSS THE WRN
SANDHILLS AND PANHANDLE. THIS IS ALONG AND NORTH OF SFC FRONT WHICH
IS EXPECTED TO LIFT THROUGH SRN AND NERN NEB LATE THIS AFTN. VERY
LARGE HAIL IS POSSIBLE WITH STORMS THIS AFTERNOON AND EVENING AND
MOST IF NOT ALL OF THIS SHOULD BE IN THE COLD AIR NORTH OF THE SFC
FRONT. THE 5 PERCENT TORNADO AND 15 PERCENT WIND PROBABILITIES WOULD
APPEAR CONDITIONALLY TIED TO STORMS FORMING ALONG THE SFC FRONT
WHICH LIFTS NORTH OF I-80 AROUND 21Z THIS AFTN AND THEN DROPS BACK
SOUTH.
SEVERE WEATHER CONTINUES THIS EVENING...PRESUMABLY ELEVATED...WITH
THE APPROACH OF THE MAIN UPPER LEVEL LOW. THE NAM AND OTHER MODELS
LIFT A DECENT SHOT OF PV15 THROUGH THE FCST AREA. MEANWHILE...LATE
SEASON ARCTIC AIR...CURRENTLY IN MONTANA DROPS THROUGH THE HIGH
PLAINS FOR A ZONE OF THUNDERSTORMS CHANGING TO WET HEAVY SNOW. THE
NAM BACKS THE ELEVATED INSTABILITY RIGHT UP AGAINST THE RAIN SNOW
LINE ACROSS SHERIDAN COUNTY AROUND 09Z. THIS MIGHT BE TOO SLOW GIVEN
THE PROXIMITY OF THE COLD AIR ACROSS MT AND THE RAIN SNOW LINE OVER
NERN WY. THE RAP CAN FIGURE THIS OUT LATER TODAY.
FOR NOW THE RAP HAS THE H700MB FREEZING LINE MOVING THROUGH SERN WY
AT 00Z THIS EVENING SO A QUICKER CHANGE TO SNOW IS POSSIBLE. THE
BEST GUESS ON SNOW AMOUNTS USES THE NAM...GEMREG...SREF AND ECM FOR
QPF WITH A 5 OT 1 RATIO FOR UP TO 4 INCHES IN NORTHERN SHERIDAN
COUNTY THROUGH 12Z THURSDAY MORING. LOCALLY HIGHER AMOUNTS COULD
DEVELOP ESPECIALLY IF THE CHANGE OVER OCCURS AT 06Z VS THE NAM MODEL
SHOWING 09Z. THE RAP HAS BEEN THE BEST PERFORMER THIS SPRING IN RAIN
SNOW EVENTS FOLLOWED THE NAM.
A WINTER WEATHER ADVISORY IS IN PLACE FOR SHERIDAN COUNTY 09Z-15Z
TONIGHT THROUGH THURSDAY MORNING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 335 AM CDT WED MAY 7 2014
LARGE UPPER LEVEL TROUGH WILL CONTINUE TO SHIFT EAST NORTHEAST
ACROSS THE CENTRAL PLAINS ON THURSDAY...REACHING THE NORTHERN
MISSOURI VALLEY EARLY FRIDAY. IN THE WAKE OF THE UPPER TROUGH
...QUASI-ZONAL FLOW WILL PREVAIL THROUGH MUCH OF THE WEEKEND...BUT
EVENTUALLY BREAK DOWN WITH THE APPROACH OF THE NEXT APPRECIABLE
WESTERN STATES UPPER TROUGH. THE SURFACE PATTERN FAVORS A
NORTHEASTWARD ADVANCING LOW TOWARD MINNESOTA AND FINALLY INTO
SOUTHWEST ONTARIO BY EARLY FRIDAY. THIS LOW WILL DRAG A FRONT
THROUGH THE CWA LEAVING POST FRONTAL CONDITIONS INTO EARLY
FRIDAY...BUT THE LOWER TROPOSPHERIC FLOW WILL RETURN TO SOUTHERLY
AS A LEE TROUGH DEVELOPS OFF THE HIGH PLAINS FRIDAY WITH THE
APPROACH OF A WEAK NORTHERN PLAINS UPPER WAVE. THIS WAVE...AS IT/S
PREDECESSOR...WILL DRAG AN ADDITIONAL FRONT THROUGH THE CWA ON
SATURDAY. THE SATURDAY BAROCLINIC ZONE IS FORECAST TO BE
WEAK...WITH LITTLE TO NO SENSIBLE CHANGES ANTICIPATED.
FOR THURSDAY...WINTER WEATHER ADVISORY ACROSS SHERIDAN COUNTY WILL
CONTINUE UNTIL 15Z. ALL THE MEDIUM RANGE DETERMINISTIC MODELS HAVE
CONVERGED SOMEWHAT ON A SOLUTION FOR WHICH THERMAL PROFILES WOULD
SUPPORT SNOW ACROSS SHERIDAN COUNTY. THERMAL PROFILES INDICATE A
DEEP SATURATION...AT TIMES EXTENDING INTO THE DGZ...BUT WARM GROUND
TEMPERATURES AND SFC T/S NEAR OR SLIGHTLY ABOVE 0C CREATE LOW
CONFIDENCE FORECAST CONCERNING ACCUMULATIONS. SINCE A STRONG
DEFORMATION ZONE IS SHOWN TO SET UP IN THIS AREA...CO-LOCATED IN THE
TROWAL REGION OF THE SYSTEM...SNOW RATES MAY BE SUFFICIENT TO
OVERCOME THE HIGH SUN ANGLE AND WARM TEMPERATURES...BUT CONFIDENCE
IS NOT ENOUGH TO EXPIRE THE ADVISORY BEFORE 15Z.
CONSEQUENTLY...GIVEN THE STRENGTH OF THE DEFORMATION...SNOW RATES
MAY BE SUFFICIENT TO ALLOW FOR SLUSH ACCUMULATION PAST 15Z THURSDAY.
FORECAST TIMING WITH THE CURRENT WINTER WEATHER ADVISORY MAY CHANGE
WITH NEAR TERM GUIDANCE.
WITH LOW LEVEL CAA ONGOING...HIGH TEMPERATURES THURSDAY WILL BE
CHILLY...40S FOR THE NORTHWEST...POSSIBLY SOME 60S SOUTHEAST. WILL
NEED TO MONITOR CLOUDS THURSDAY NIGHT AND FRIDAY MORNING AS ANY
CLEARING WOULD LEAD TO SUB 0C LOWS...WITH THE THREAT OF A LIGHT
FREEZE. ATTM...FAVORING THE ECMWF SOLUTION WHICH IS ON SLOWER
SIDE...KEEPING SUFFICIENT CLOUDS ACROSS MUCH OF THE FORECAST AREA
TO PREVENT A WIDESPREAD FREEZE. ATTM...NORTHWEST NEBRASKA WOULD
HAVE THE HIGHEST POTENTIAL OF SEEING A DAMAGING FREEZE /TO YOUNG
PLANTS/...ESPECIALLY IF SNOW TOTALS ARE HIGHER THAN CURRENTLY
ANTICIPATED. THE ENTIRE NORTH PLATTE CWA HAS NOT REACHED THE 50
PERCENTILE FOR LAST FREEZE DATE...WE DO NOT PLAN TO FROST/FREEZE
HEADLINES ATTM.
FRIDAY...WITH RETURN FLOW DIRECTING WAA BACK INTO THE
CWA...TEMPERATURES SHOULD WARM BACK WELL INTO THE 60S...POSSIBLY
LOWER 70S FOR THE ENTIRE CWA. BUT A FAST MOVING WAVE PASSING
THROUGH THE QUASI-ZONAL FLOW MAY SPARK OFF A SHOWER OR TWO DURING
THE EVENING AND EARLY ON SATURDAY...WITH A WEAK WIND SHIFT TO
FOLLOW. AGAIN SATURDAY TEMPERATURES WON/T BE TOO FAR OFF FROM
CLIMO...GENERALLY HIGHS IN THE 60S TO LOWER 70S CAN BE EXPECTED FOR
MOST IF NOT ALL LOCATIONS. LATE WEEKEND INTO EARLY NEXT
WEEK...ANOTHER SYSTEM LOOKS TO MOVE INTO THE CENTRAL ROCKIES
SATURDAY NIGHT AND EMERGE ONTO THE PLAINS SUNDAY AND MONDAY.
WIDESPREAD PRECIPITATION WILL BE POSSIBLE...AND DESPITE DIFFERENCES
WITH THE HANDLING OF THE SYSTEM...WILL MAINTAIN 30-40 POPS LATE
WEEKEND INTO EARLY NEXT WEEK FOR MUCH OF THE CWA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1224 AM CDT WED MAY 7 2014
ISOLATED THUNDERSTORMS WILL DISSIPATE IN THE OVERNIGHT HOURS
ACROSS THE EASTERN NEBRASKA PANHANDLE AND NORTHWESTERN SANDHILLS.
ATTM THIS ACTIVITY WILL REMAIN WEST OF THE KLBF AND KVTN
TERMINALS. SKIES WILL BE MOSTLY CLOUDY OVERNIGHT WITH CIGS RANGING
FROM 15000 TO 20000 FT AGL. AT THE KLBF TERMINAL...SOME LOW CLOUDS
MAY DEVELOP OVERNIGHT TONIGHT AS LOW LEVEL MOISTURE PUSHES INTO
SOUTHERN AND CENTRAL NEBRASKA FROM THE EAST. CIGS MAY DROP TO
AROUND 1000 FT AGL AT THE KLBF TERMINAL AROUND 12Z WEDNESDAY. CIGS
WILL LIFT BY LATE MORNING WITH MOSTLY HIGH CLOUDS EXPECTED INTO
THE AFTERNOON AND EVENING HOURS. BY 22Z WEDNESDAY...THE THREAT FOR
THUNDERSTORMS WILL INCREASE ACROSS SOUTHWESTERN NEBRASKA AND
CONTINUE THROUGH LATE EVENING WEDNESDAY. AT THIS TIME...THE THREAT
WILL BE FAIRLY LOW AND WILL BE HANDLED WITH A PROB 30 GROUP. FOR
THE KVTN TERMINAL...BROKEN CIGS AROUND 15000 FT AGL WILL LOWER TO
AROUND 4000 FT AGL BY MID MORNING WEDNESDAY AND PERSIST THROUGH
06Z THURSDAY. THE THREAT FOR THUNDERSTORMS WILL INCREASE AFTER 00Z
THURSDAY. WITH SCATTERED COVERAGE EXPECTED AND SOME DOUBT AS TO
WHEN THUNDERSTORMS WILL OCCUR...WILL HANDLE THE MENTION WITH A
PROB 30 GROUP.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 AM TO 9 AM MDT THURSDAY FOR
NEZ004.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1137 PM CDT TUE MAY 6 2014
.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 305 PM CDT TUE MAY 6 2014
THE MAIN FORECAST CONCERNS IN THE SHORT TERM ARE SMALL PRECIP
CHANCES TONIGHT...FIRE WEATHER CONCERNS AND HOW WARM TEMPERATURES
WILL GET WEDNESDAY...THEN RAIN CHANCES WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT.
FIRE WEATHER FORECAST CONCERNS ARE ADDRESSED BELOW.
THIS MORNING/S UPPER AIR MAPS SHOWED A MID TROPOSPHERIC TROF OVER
THE WEST COAST WITH A RIDGE OVER THE SOUTHEAST U.S. SOUTHWEST FLOW
ALOFT WAS TRANSPORTING SOME MID LEVEL MOISTURE INTO THE REGION.
WARM...+12C H7 TEMPERATURES WERE NOTED OVER KANSAS. AT H85...THERE
WAS SOME POOLING OF HIGHER DEWPOINTS AT OAX...HOWEVER IT WAS
FAIRLY DRY AT H85 ACROSS THE PLAINS. THE SURFACE MAP AT
20Z...CONTINUED TO SHOW EAST AND SOUTHEAST FLOW WITH TEMPERATURES
IN THE 70S...HOWEVER...THE MID 80 HAD MADE IT INTO FALLS CITY.
BASED ON THE SURFACE WINDS AND TEMPERATURES...IT APPEARS THE WARM
FRONT HAD LIFTED INTO SOUTHEAST NEBRASKA AND SHOULD BE AROUND
LINCOLN.
TONIGHT AND WEDNESDAY...THE SURFACE FRONT WILL LIFT NORTH INTO
NORTHEAST NEBRASKA AS SURFACE LOW PRESSURE FORMS IN NORTHEAST
COLORADO. THE LOW LEVEL JET WILL STRENGTHEN ACROSS EASTERN KANSAS
INTO SOUTHEAST NEBRASKA AND THERE IS SOME BROAD SYNOPTIC LIFT
ALONG WITH STEEP LAPSE RATES AND WEAK FRONTOGENESIS ALONG WITH
SOME WEAK HEIGHT FALLS. THE TRAJECTORY FOR THE BEST PLACEMENT OF
PRECIPITATION IS MORE TOWARD CENTRAL IOWA INTO MINNESOTA...HOWEVER
SOMETHING ISOLATED MAY TRY TO DEVELOP IN OUR FORECAST AREA...ALONG
AND NORTH OF THE WARM FRONT. DEEP MOISTURE APPEARS TO BE A
LIMITING FACTOR AND MOST OF THE OPERATIONAL MODELS KEEP THE PRECIP
CHANCES ON THE FRINGES OF OUR FORECAST AREA OR OUT OF THE AREA.
FORECAST SOUNDINGS SHOW THAT IF SOMETHING HIGH BASED DOES
DEVELOP...THERE WOULD BE THE POTENTIAL FOR SOME GUSTY WINDS WITH
ANY ISOLATED STORMS. FOR NOW...FAR NORTHEAST NEBRASKA AND WESTERN
IOWA IS WHERE OUR ISOLATED THUNDERSTORM CHANCES ARE MENTIONED. THE
LATEST RAP IS HINTING AT SOMETHING IN SOUTHEAST NEBRASKA THIS
EVENING...SO THIS WILL NEED TO BE WATCHED.
WEDNESDAY AFTERNOON...THE VERY DRY AIR OVER PARTS OF SOUTHWEST
KANSAS ARE FORECAST TO BE DRAWN NORTHEASTWARD AHEAD OF THE FRONT.
THIS COMBINED WITH FAVORABLE MIXING AND SOUTHWEST WINDS SHOULD
RESULT IN HOTTER TEMPERATURES IN THE 80S TO LOWER 90S...RESULTING
VERY HIGH TO EXTREME FIRE DANGER CONDITIONS. IT DOES NOT LOOK LIKE
RECORDS 95/96/99 OMAHA/LINCOLN/NORFOLK... BUT COULD GET CLOSE IF
FULL HEATING IS REALIZED. AS DISCUSSED BELOW...DUE TO THE
GREENESS...THE RFW WAS LIMITED TO THE AREA THAT HAS BEEN THE
DRIEST.
WEDNESDAY NIGHT INTO THURSDAY NIGHT...THE MID LEVEL TROF CONTINUE
TO MOVE INTO THE PLAINS WITH MOISTURE RICH AIR RETURNING TO
EASTERN KANSAS AND A NARROW AREA MAKING IT INTO EASTERN NEBRASKA
AND WESTERN IOWA. DO HAVE SCATTERED SHOWERS AND THUNDERSTORMS
MENTIONED. THERE IS A SEVERE POTENTIAL WITH THESE STORMS DUE TO
THE MODERATE INSTABILITY AND FAVORABLE SHEAR PROFILES.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 PM CDT TUE MAY 6 2014
THERE ARE STILL SOME LARGE MODEL DIFFERENCES. STILL LOOKS LIKE A
CHANCE FOR THUNDERSTORMS SATURDAY AND SATURDAY NIGHT. LARGER
DIFFERENCES FOR THE REST OF THE WEEKEND INTO EARLY NEXT WEEK.
TEMPERATURES STILL LOOK TO MOSTLY BE IN THE 60S AND 70S.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1134 PM CDT TUE MAY 6 2014
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF CYCLE. ADVERTISED LOW
LEVEL MOISTURE HAS NOT PRODUCED AN MVFR CLOUD DECK SO HAVE REMOVED
ANY MENTION IN TAFS. SOME HAZY CONDITIONS CANNOT BE COMPLETELY
RULED OUT IN THE MORNING...HOWEVER CONFIDENCE IN THIS IS FAIRLY
LOW SO WILL NOT MENTION IN THE TAFS. A WARM FRONT IN THE AREA WILL
CONTINUE TO SLOWLY DRIFT NORTH. SOUTHWEST SFC WINDS WILL INCREASE
AT KLNK AND KOMA WED AFTERNOON HOWEVER MAY REMAIN FAIRLY LIGHT OUT
OF THE SOUTHEAST AT KOFK.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING FROM NOON TO 8 PM CDT WEDNESDAY FOR NEZ051-065-
066-078-088-089.
IA...NONE.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...KERN
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1143 PM MDT TUE MAY 6 2014
.AVIATION...
06Z TAF CYCLE
WINDS HAVE DIMINISHED ACROSS NORTHERN AND CENTRAL NEW
MEXICO THIS EVENING...BUT ARE EXPECTED TO STRENGTHEN AGAIN LATE
WEDNESDAY MORNING...REMAINING GUSTY THROUGH EARLY TOMORROW EVENING.
SOME SMOKE MAY BE VISIBLE NEAR AND DOWNWIND OR EAST NORTHEAST OF
THE JEMEZ MOUNTAINS WHERE PRESCRIBED BURNS HAVE BEEN ONGOING...BUT
NO PERCEIVABLE VISIBILITY REDUCTIONS ARE EXPECTED. WINDS WILL BE
STRONGEST IN CENTRAL TO EASTERN NEW MEXICO WEDNESDAY AFTERNOON
WHERE OCCASIONAL GUSTS WILL APPROACH 40 TO 45 KT.
52
&&
.PREV DISCUSSION...745 PM MDT TUE MAY 6 2014...
.UPDATE...
UPDATED FORECAST TO ISSUE A WIND ADVISORY FOR WEDNESDAY FOR MUCH
OF CENTRAL...SOUTH CENTRAL AND EASTERN NEW MEXICO. ALSO UPGRADED
THE FIRE WEATHER WATCH FOR THE MIDDLE RIO GRANDE VALLEY. TIMING OF
THE COLD FRONT WEDNESDAY AROUND MAX HEATING HERE IN THE MIDDLE RIO
GRANDE VALLEY LENDING MORE CONFIDENCE TO SEEING AT LEAST A COUPLE
HOURS OF WIND ADVISORY SPEEDS...WITH BLOWING DUST LOOKING MORE
LIKELY AS WELL. THE WIND ADVISORY EXPIRES AT 8 PM MDT WEDNESDAY...
BUT MAY NEED TO BE EXTENDED FOR SOME OF THE EAST CENTRAL AND
NORTHEAST PLAINS GIVEN THE TIMING OF THE CORE OF STRONGER WINDS
ALOFT AS THE UPPER TROUGH PULLS NE ACROSS NW NEW MEXICO AND INTO
COLORADO.
11
&&
.PREV DISCUSSION...246 PM MDT TUE MAY 6 2014...
.SYNOPSIS...
THE NEXT STORM SYSTEM APPROACHING NEW MEXICO FROM THE WEST WILL
DELIVER ANOTHER PUNCH OF SPRING WINDS AND BLOWING DUST WEDNESDAY.
WIDESPREAD DANGEROUS FIRE WEATHER CONDITIONS WILL ACCOMPANY THE WIND
AS CONDITIONS ARE EXTREMELY DRY OVER THE AREA. THE WELL ABOVE NORMAL
HIGH TEMPERATURES OVER THE PAST SEVERAL DAYS WILL COOL BACK TO BELOW
NORMAL FOR THE WEST WEDNESDAY...THEN ALL AREAS THURSDAY AND FRIDAY.
A FEW LOCATIONS ACROSS THE NORTHERN AND WESTERN HIGH TERRAIN ALSO
HAVE THE POTENTIAL FOR A COUPLE SHOWERS AND THUNDERSTORMS BOTH
DAYS. TEMPERATURES WILL REBOUND AGAIN BACK NEAR TO SLIGHTLY ABOVE
NORMAL FOR THE WEEKEND WITH WIDESPREAD BREEZY CONDITIONS EXPECTED.
&&
.DISCUSSION...
MSAS ANALYSIS SHOWED SURFACE LOW PRESSURE DEEPENED TO 994MB AT 19Z
OVER SE COLORADO AND THE 19Z RAP INDICATES THIS WILL CONTINUE TO
989MB BY 00Z. MEANWHILE UPPER LEVEL WINDS ARE INCREASING OVER THE
REGION AHEAD OF AN APPROACHING H5 UPPER LOW OVER EAST CENTRAL NV.
SURFACE OBS AT KLVS HAVE BEEN NEAR OR JUST ABOVE WIND ADVISORY A
COUPLE TIMES BUT SINCE ISOLD IN NATURE WILL NOT ISSUE HIGHLIGHTS.
MORE SIGNIFICANT WINDS WILL ARRIVE WEDNESDAY AS THE CORE OF A
40-50KT 700-500MB JET SLIDES OVER CENTRAL/EASTERN NM. WILL PASS
ALONG WIND ADVISORY HIGHLIGHTS TO OVERNIGHT CREW.
ON THE QPF SIDE OF THINGS THERE ISNT MUCH TO GET EXCITED ABOUT. WPC
PROBABILISTIC QPF VALUES FOR 0.10 OR MORE DO SHOW VALUES AROUND 30
PCT OVER SW FACING SLOPES OF THE NW MTS WEDNESDAY. GFS/NAM LIFTED
INDICES ARE NEAR -2C FOR TMRW AFTERNOON SO THUNDER POTENTIAL STILL
EXISTS. RAISED POPS INTO THE 40 AND 50 PCT RANGE BUT AMOUNTS WILL
BE VERY LIGHT. ALSO TOSSED IN DUST FOR THE NW PLATEAU. MAX TEMPS
WILL TREND COLDER OVER THE WEST THEN 5 TO 15F BLW NORMAL FOR ALL
AREAS THURSDAY. IT WILL FEEL QUITE COOL THURSDAY WITH WIDESPREAD
BREEZY CONDITIONS AND ANOTHER ROUND OF SHOWERS/ISOLD STORMS NEAR
AND EAST OF HIGH TERRAIN. AGAIN QPF WILL BE VERY LIGHT.
FLOW WILL RELAX SLIGHTLY AND BECOME MORE ZONAL WITH WARM ADVECTION
THRU THE WEEKEND. GENERALLY CLEAR SKIES ARE EXPECTED MOST AREAS WITH
THE EXCEPTION OF HIGH CLOUDS OVER THE NORTH. 700MB TEMPS WILL WARM
TO NEAR +12C WHICH IS NEAR THE 75 PERCENTILE FOR MID MAY. THAT WILL
TRANSLATE TO HIGHS 5 TO 15F ABV NORMAL AGAIN. MODEL CONSISTENCY AND
OUTLOOK FOR NEXT WEEK IS ALMOST COMICAL SO WILL LEAVE THAT FOR LATER.
GUYER
&&
.FIRE WEATHER...
WIDESPREAD RED FLAG CONDITIONS WILL CONTINUE THROUGH MID EVENING.
HAVE UPGRADED ZONES 103 AND 107 TO A RED FLAG WARNING FOR WEDNESDAY
LATE MORNING TO EARLY EVENING. WILL LEAVE ZONE 106 AS A WATCH AND
LET THE STELLAR NIGHT CREW TAKE ONE MORE LOOK.
CHANGE IN THE WEATHER IS ON THE WAY WITH COOLER TEMPERATURES AND
EVENTUALLY LESS WIND...THANKS TO A POTENT COLD FRONT TOMORROW AND
UPPER LEVEL DISTURBANCE. ONLY MODEST PRECIPITATION CHANCES ACROSS
THE NORTH IN THE WEDNESDAY THROUGH THURSDAY TIME PERIOD.
WIDESPREAD CRITICAL FIRE WEATHER CONDITIONS TO CONTINUE THROUGH
MID EVENING FOR MUCH OF NORTHERN AND CENTRAL NEW MEXICO. WINDS
TO SUBSIDE DURING THE NIGHT ASIDE FROM MODERATE BREEZES OVER THE
MOUNTAINS AND EAST SLOPES. WINDS WILL INCREASE QUICKLY WEDNESDAY
AND BE THE STRONGEST WINDS OF THE WEEK. CRITICAL FIRE WEATHER WILL
BE EASILY REACHED OVER MOST CENTRAL AND ALL EASTERN AREAS. HIGH
TEMPERATURES WILL BE LOWER EVERYWHERE...BUT STILL ABOVE NORMAL IN
THE FAR EAST. THIS WILL BE THE AREA WITH THE LOWEST RH VALUES WITH
SINGLE DIGIT READINGS FOR ABOUT 10 HOURS. HAINES VALUES TO BE HIGH
TO MODERATE. AREAS TO THE WEST ARE MORE IN THE GREY AREA AS TO HOW
TO TREAT THE CRITICAL FIRE WEATHER CONDITIONS. WHILE WINDS WILL BE
VERY STRONG AND HUMIDITIES BELOW 15 PERCENT FOR MANY HOURS...THE
TEMPERATURES WILL BE NEAR TO BELOW NORMAL IN ZONES 103 AND 107.
WITH HAINES VALUES STILL PARTLY IN THE HIGH CATEGORY IN ZONES 103
AND 10 WILL GO AHEAD AND UPGRADE THESE ZONES TO A RED FLAG WARNING
FOR WEDNESDAY. WILL LEAVE ZONE 106...MIDDLE RIO GRANDE VALLEY...AS
A WATCH. CERTAINLY WINDS AND HUMIDITIES WILL BE CRITICAL FOR SEVERAL
HOURS...BUT LOW TO MODERATE HAINES VALUES AND HIGHS SEVERAL DEGREES
BELOW NORMAL BRING A MIXED SIGNAL AS TO JUST HOW CRITICAL THIS AREA
WILL BE. AS MENTIONED ABOVE WILL LET NIGHT CREW MAKE THE CALL ON
ZONE 106. WILL NEED TO FACTOR IN HOW INCREDIBLY DRY IT HAS BEEN
LATELY AS WELL. AS FOR CHANCE OF PRECIPITATION...ONLY THE NORTHWEST
AND NORTH CENTRAL HIGHER TERRAIN COULD SEE A SHOWER OR THUNDERSTORM
WEDNESDAY.
MUCH COOLER AIR WILL CONTINUE TO POUR INTO THE STATE WEDNESDAY NIGHT
AND THURSDAY. WINDS WILL ALSO FINALLY DIMINISH FOR MOST AREAS. IT
WILL STILL BE BREEZY ACROSS THE EAST CENTRAL AREAS. A FEW RAIN AND
MOUNTAIN SNOW SHOWERS WILL BE POSSIBLE ACROSS THE WEST AND NORTH
BUT NO WETTING PRECIPITATION.
FRIDAY SHOULD BE DRY AND MILDER WITH NEAR NORMAL TEMPERATURES AND
NOT MUCH WIND.
THE WEEKEND SHOULD BE MOSTLY DRY WITH THE WARMING TREND CONTINUING
SATURDAY AND LEVELING OFF ON SUNDAY. AN APPROACHING BACK DOOR COLD
FRONT COULD TRIGGER A SHOWER IN THE NORTHEAST AND OVER THE NORTHERN
MOUNTAINS LATE SUNDAY.
THE START OF NEXT WEEK WILL BE COOLER IN THE EAST. IT WILL BE DRY
ASIDE FROM A NORTHERN MOUNTAIN SHOWER. THE EUROPEAN MODEL IS MORE
BULLISH WITH A TROUGH AND THE PRECIPITATION POTENTIAL FOR EARLY NEXT
WEEK. THEN THE GFS GOES BONKERS WITH A STRONG BACK DOOR COLD FRONT
BY THE MIDDLE OF NEXT WEEK AND SIGNIFICANT PRECIPITATION IN THE EAST
BEHIND THE FRONT. JUST WISHFUL THINKING AT THIS POINT.
CHJ
&&
.AVIATION...
18Z TAF CYCLE
STORM OVER THE GREAT BASIN TO HEAD SLOWLY EAST. NEAR SFC WINDS
STRONGER TODAY THAN MONDAY. SW WIND GUSTS OF 28-30 KTS AT
FMN...ABQ...AEG AND SAF. SW WIND GUSTS OF 35-37 KTS OTHER TAF
SITES. NO RESTRICTIONS TO VSBY DUE TO DUST IN ANY TAF FORECAST BUT
COULD BE SOME MODEST RESTRICTIONS ARE NOT ENTIRELY OUT OF THE
QUESTION...MAINLY FOR LVS...TCC AND ROW. OTHERWISE...VFR
CONDITIONS ARE FORECAST TO PERSIST. STRONG WINDS AGAIN WED OVER
THE E...LOWER SPEEDS IN THE WEST.
40
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 10 AM TO 8 PM MDT WEDNESDAY FOR THE FOLLOWING
ZONES...NMZ103-104-106>108.
WIND ADVISORY FROM NOON TO 8 PM MDT WEDNESDAY FOR THE FOLLOWING
ZONES...NMZ515-519>540.
&&
$$
AREA FORECAST DISCUSSION
NWS BISMARCK ND
710 PM CDT THU MAY 8 2014
.UPDATE...
ISSUED AT 655 PM CDT THU MAY 8 2014
AT 630 PM CDT...SATELLITE LOOPS SHOW HIGH CLOUDS SPREADING OVER
SOUTHWEST NORTH DAKOTA REPOPULATING THE CLEAR AREA. H300 CLOSED
LOW ON THE RAP MODEL SUGGESTS CIRCULATION AROUND THIS FEATURE IN
NORTHEAST WYOMING LIKELY HELPING TO SPREAD THESE HIGH CLOUDS OVER
SOUTHWEST ND. MEANWHILE...H500 LOW MIGRATING THROUGH NORTHEAST SOUTH
DAKOTA INTO SOUTHEAST NORTH DAKOTA. LIKE THE CURRENT POPS AND WILL
NOT CHANGE AT THIS TIME. MAINLY CLOUDS. MAY BE ABLE TO DROP POPS
CENTRAL AFTER 9 PM.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 339 PM CDT THU MAY 8 2014
RAINFALL ENDING THIS EVENING AND A DRY FRIDAY WILL HIGHLIGHT THE
SHORT TERM.
RAINFALL THE REMAINDER OF THE AFTERNOON IS EXPECTED TO REMAIN
ALONG AND EAST OF A LINE FROM SELFRIDGE...THROUGH BISMARCK AND
HARVEY...SLOWLY DECREASING FROM WEST TO EAST. BASED UPON THE 17-19
UTC RAP/HRRR...RAIN SHOULD FINALLY END ACROSS THE JAMES RIVER
VALLEY BY 06-07 UTC. OTHERWISE FOR TONIGHT...A WEAK SURFACE RIDGE
AXIS WILL BE IN PLACE ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
GIVEN CLEAR SKIES...LIGHT WINDS AND DEW POINTS IN THE UPPER TEENS
AND 20S...WIDESPREAD OVERNIGHT LOWS IN THE 20S ARE FORECAST OUTSIDE
OF THE JAMES RIVER VALLEY WHERE GREATER CLOUD COVER AND MOISTURE
WILL KEEP LOWS IN THE 30S. LEFT THE MENTION OF FOG OUT FOR NOW DUE
TO DECEASING LOW LEVEL MOISTURE PROFILES WITH HEIGHT AND THE
GREATER LIKELIHOOD OF FROST COMPARED TO FOG. FRIDAY WILL BE CLEAR
AND DRY WITH HIGHS IN THE 60S WITH SOUTHERLY FLOW AHEAD OF THE
SURFACE LOW ACROSS EASTERN MONTANA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 339 PM CDT THU MAY 8 2014
AN ACTIVE AND COOL WEATHER PATTERN DEVELOPS FOR THE UPCOMING
WEEKEND. UNCERTAINTY INCREASES AFTERWARDS WHEN COMPARING THE
LATEST FEW RUNS OF THE GFS AND ECMWF.
UPPER LOW/TROUGH OVER THE PACIFIC NORTHWEST DIGS ACROSS THE
WESTERN CONUS FRIDAY NIGHT INTO SATURDAY...MOVING OVER THE ROCKIES
SUNDAY. 12Z GFS IS MORE PROGRESSIVE AND MOVES THE TROUGH EAST BY
MONDAY NIGHT...WHILE THE 00Z/12Z ECMWF LINGERS THE TROUGH THROUGH
TUESDAY. NORTHWEST FLOW IS ADVERTISED BY BOTH MODELS BEHIND THE
TROUGH...LIKELY ACTIVE WITH EMBEDDED WAVES MOVING THROUGH THE
REGION.
BASICALLY HAVE CHANCES FOR PRECIPITATION THROUGH THE PERIOD ALONG
WITH CONTINUED COOL/BELOW AVERAGE TEMPERATURES. BEST CHANCES FOR
PRECIPITATION WILL BE OVER THE WEEKEND AS SFC LOW PRESSURE AND LEAD
WAVES MOVE ACROSS THE DAKOTAS. MIX OF RAIN/SNOW POSSIBLE WEST
SUNDAY MORNING AS COLDER AIR IS PULLED SOUTH FROM CANADA.
ADDITIONAL SNOW POSSIBLE EARLY NEXT WEEK IF THE EUROPEAN`S
SOLUTION IS CORRECT WITH A SLOWER EASTWARD PROGRESSION ALLOWING
FOR ANOTHER SHOT OF COLD AIR INTO THE REGION.
MODELS PORTRAY NO INDICATION OUR COOL AND WET PATTERN WILL CHANGE
THROUGH AT LEAST MID-MAY...AND POSSIBLY NOT UNTIL AFTER THE THIRD
WEEK OF MAY AT THE EARLIEST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 655 PM CDT THU MAY 8 2014
HIGH PRESSURE OVER WESTERN NORTH DAKOTA WILL MAINTAIN VFR
CONDITIONS ACROSS WESTERN NORTH DAKOTA. SURFACE LOW PRESSURE
ACROSS MINNESOTA WILL SPREAD SHOWERS AND MVFR CONDITIONS ACROSS
EASTERN NORTH DAKOTA THROUGH THE EVENING. VFR KISN-KDIK-KBIS-
KMOT. OCNL MVFR CONDITIONS IN KJMS WILL IMPROVE TO VFR AFTER 08Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...NH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
137 PM CDT WED MAY 7 2014
.UPDATE...
ISSUED AT 137 PM CDT WED MAY 7 2014
NO SIGNIFICANT CHANGES WITH THIS UPDATE OTHER THAN TO ADJUST POPS
FOR THE LATEST RADAR TRENDS THROUGH 1830 UTC...BLENDED TO THE 17
UTC RAP AND THE REMAINING 12 UTC DETERMINISTIC CONSENSUS WHICH
SUGGESTS PRECIPITATION DECREASING SIGNIFICANTLY BY 21-00 UTC AND
THROUGH THE NIGHT. DID MAINTAIN A MENTION OF SNOW ACROSS THE WEST
WITH MULTIPLE LOCATIONS AT LEAST INTERMITTENTLY CONTINUING TO
REPORT SNOW.
UPDATE ISSUED AT 1026 AM CDT WED MAY 7 2014
UPDATE TO ADD SNOW AND SLEET TO PORTIONS OF NORTHWEST AND NORTH
CENTRAL NORTH DAKOTA THIS MORNING FOR LOCATIONS IN THE MID TO
UPPER 30S AS OF 1530 UTC. THIS IS BASED UPON MULTIPLE REPORTS
BETWEEN WATFORD CITY AND WILLISTON AND THE KEENE AREAS AND DUAL POL
SIGNATURES.
UPDATE ISSUED AT 826 AM CDT WED MAY 7 2014
QUICK UPDATE TO ADJUST POPS TO THE LATEST OBSERVED TRENDS THROUGH
13 UTC...INCORPORATING THE 11 UTC RAP/HRRR THROUGH THE REMAINDER
OF THE AFTERNOON AND EARLY EVENING. ALSO DECREASED CLOUD COVER
ACROSS THE NORTHWEST WHERE LOW TO MID LEVEL DECKS ARE THINNING
WHICH SHOULD LEAD TO AT LEAST PARTLY SUNNY SKIES.
UPDATE ISSUED AT 650 AM CDT WED MAY 7 2014
CURRENT RADAR OBS/TRENDS MATCH THE ONGOING FORECAST.
FURTHERMORE...THE LATEST HRRR MATCHES THE LATEST RADAR OBS AND
FORECAST TRENDS. WILL CONTINUE TO LEAN HEAVILY ON THE HRRR FOR
HOURLY POPS THROUGH THE AFTERNOON. OTHERWISE...THE CURRENT
FORECAST IS ON TRACK WITH NO MAJOR UPDATES REQUIRED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT WED MAY 7 2014
THE LATEST WATER VAPOR CONTINUES TO SHOW A MOIST SOUTHWEST FLOW
INTO NORTH DAKOTA WITH MULTIPLE SHORTWAVES AHEAD OF A MAIN UPPER
LOW NOW ALONG THE NEVADA/UTAH BORDER. THIS LOW WILL CLOSE OFF AND
PIVOT NORTHEAST THROUGH THE SHORT TERM PERIOD...AND WILL BECOME
THE MAIN PRECIPITATION PRODUCER OVER SOUTH CENTRAL NORTH DAKOTA
LATER WEDNESDAY NIGHT. UNTIL THEN...MODEL GUIDANCE SUGGESTING
SEVERAL AREAS OF RAIN SHOWERS WILL MOVE FROM SOUTHWEST TO
NORTHEAST TODAY AND THUS FAR LOCAL/REGIONAL RADAR CONFIRMS THIS.
OVERALL POPS ARE LIKELY TO CATEGORICAL FOR WESTERN AND MOST OF
CENTRAL NORTH DAKOTA TODAY...WITH THE JAMES RIVER VALLEY SEEING
HIGHEST POPS LATER THIS AFTERNOON AND AGAIN LATE WEDNESDAY NIGHT.
CATEGORICAL POPS HAVE BEEN PAINTED ALONG/NEAR A SURFACE INVERTED
TROUGH/BAROCLINIC ZONE...WHICH CURRENTLY STRETCHES FROM SHERWOOD
TO MINOT...SOUTH TO CENTER AND INTO MOBRIDGE SOUTH DAKOTA. THIS
SURFACE TROUGH WILL SHIFT EAST DURING THE DAY REACHING THE JAMES
RIVER VALLEY LATE THIS AFTERNOON. ONCE THIS TROUGH EXITS THE JAMES
RIVER VALLEY EARLY THIS EVENING...EXPECT A BRIEF LULL IN THE
WIDESPREAD PRECIPITATION...ESSENTIALLY COVERING THE 00Z-06Z
THURSDAY TIME FRAME. HOWEVER POPS WILL ONCE AGAIN INCREASE ACROSS
THE SOUTH AND SOUTH CENTRAL TOWARD AND AFTER 06Z THURSDAY IN
RESPONSE TO THE VERTICAL MOTION FIELD AS THE CLOSED MID LEVEL LOW
APPROACHES. HAVE MAINTAINED THE TREND TO KEEP ANY MENTION OF
THUNDER SOUTH OF THE BORDER AS INSTABILITY PARAMETERS PER GFS
FOLLOW THIS TREND.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 324 AM CDT WED MAY 7 2014
AN UPPER LEVEL SHORTWAVE EMANATING FROM THE ROCKIES IS PROGGED TO
LIFT NORTH ACROSS THE CENTRAL AND NORTHERN PLAINS THURSDAY. THIS
FEATURE SHOULD GENERATE RAIN SHOWERS EXTENDING ALONG AND SOUTH OF
A LINE FROM HETTINGER TO BISMARCK TO HARVEY. HOWEVER...HIGH
PRESSURE BUILDING INTO EASTERN MONTANA SHOULD KEEP THE FORECAST
DRY FOR NORTHWESTERN NORTH DAKOTA.
A BREAK IN PRECIP CHANCES IS FORECAST FOR FRIDAY AS HIGH PRESSURE
CRESTS ACROSS THE REGION. TEMPERATURES ARE FORECAST TO GET IN THE
MID TO UPPER 60S FRIDAY.
PRECIPITATION CHANCES RETURN OVER NORTH DAKOTA SATURDAY AS A
SHORTWAVE EMANATING FROM THE PACIFIC NORTHWEST TRAVERSES THE
NORTHERN PLAINS.
THE MEDIUM RANGE MODELS DIVERGE WITH RESPECT TO THE UPPER PATTERN
OVER THE CONUS SUNDAY THROUGH THE REMAINDER OF THE PERIOD.
THEREFORE...THERE IS QUITE A BIT OF UNCERTAINTY REGARDING THE
FORECAST FOR THE FIRST HALF OF NEXT WEEK. EVEN THOUGH A PERSISTENT
UPPER LEVEL LOW OVER SASKATCHEWAN IS FORECAST TO MAINTAIN AN
UNSETTLED WEATHER REGIME OVER NORTH DAKOTA...THE MODELS HAVE BEEN
BACKING OFF ON PRECIP CHANCES/QPF AMOUNTS DUE TO DRY SLOTTING. AS
A RESULT...LOWERED POPS TO SLIGHT CHANCE/LOW-END CHANCE SUNDAY AND
MONDAY...AND REMOVED POPS FOR MOST OF THE CWA TUESDAY.
TEMPERATURES ARE STILL FORECAST TO REMAIN BELOW CLIMO VALUES THIS
WEEKEND THROUGH THE FIRST PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 137 PM CDT WED MAY 7 2014
IFR CONDITIONS AT KDIK AND KMOT IN RAIN...STRATUS AND FOG WILL
CONTINUE TO IMPROVE TO MVFR BY LATE THIS AFTERNOON. MVFR
CONDITIONS IN RAIN WILL CONTINUE AT KBIS THROUGH 20 UTC AND 22-23
UTC AT KJMS. MVFR CONDITIONS IN STRATUS ARE POSSIBLE AT KBIS/KJMS
THEREAFTER.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...KS
LONG TERM...TM
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1027 AM CDT WED MAY 7 2014
.UPDATE...
ISSUED AT 1026 AM CDT WED MAY 7 2014
UPDATE TO ADD SNOW AND SLEET TO PORTIONS OF NORTHWEST AND NORTH
CENTRAL NORTH DAKOTA THIS MORNING FOR LOCATIONS IN THE MID TO
UPPER 30S AS OF 1530 UTC. THIS IS BASED UPON MULTIPLE REPORTS
BETWEEN WATFORD CITY AND WILLISTON AND THE KEENE AREAS AND DUAL POL
SIGNATURES.
UPDATE ISSUED AT 826 AM CDT WED MAY 7 2014
QUICK UPDATE TO ADJUST POPS TO THE LATEST OBSERVED TRENDS THROUGH
13 UTC...INCORPORATING THE 11 UTC RAP/HRRR THROUGH THE REMAINDER
OF THE AFTERNOON AND EARLY EVENING. ALSO DECREASED CLOUD COVER
ACROSS THE NORTHWEST WHERE LOW TO MID LEVEL DECKS ARE THINNING
WHICH SHOULD LEAD TO AT LEAST PARTLY SUNNY SKIES.
UPDATE ISSUED AT 650 AM CDT WED MAY 7 2014
CURRENT RADAR OBS/TRENDS MATCH THE ONGOING FORECAST.
FURTHERMORE...THE LATEST HRRR MATCHES THE LATEST RADAR OBS AND
FORECAST TRENDS. WILL CONTINUE TO LEAN HEAVILY ON THE HRRR FOR
HOURLY POPS THROUGH THE AFTERNOON. OTHERWISE...THE CURRENT
FORECAST IS ON TRACK WITH NO MAJOR UPDATES REQUIRED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT WED MAY 7 2014
THE LATEST WATER VAPOR CONTINUES TO SHOW A MOIST SOUTHWEST FLOW
INTO NORTH DAKOTA WITH MULTIPLE SHORTWAVES AHEAD OF A MAIN UPPER
LOW NOW ALONG THE NEVADA/UTAH BORDER. THIS LOW WILL CLOSE OFF AND
PIVOT NORTHEAST THROUGH THE SHORT TERM PERIOD...AND WILL BECOME
THE MAIN PRECIPITATION PRODUCER OVER SOUTH CENTRAL NORTH DAKOTA
LATER WEDNESDAY NIGHT. UNTIL THEN...MODEL GUIDANCE SUGGESTING
SEVERAL AREAS OF RAIN SHOWERS WILL MOVE FROM SOUTHWEST TO
NORTHEAST TODAY AND THUS FAR LOCAL/REGIONAL RADAR CONFIRMS THIS.
OVERALL POPS ARE LIKELY TO CATEGORICAL FOR WESTERN AND MOST OF
CENTRAL NORTH DAKOTA TODAY...WITH THE JAMES RIVER VALLEY SEEING
HIGHEST POPS LATER THIS AFTERNOON AND AGAIN LATE WEDNESDAY NIGHT.
CATEGORICAL POPS HAVE BEEN PAINTED ALONG/NEAR A SURFACE INVERTED
TROUGH/BAROCLINIC ZONE...WHICH CURRENTLY STRETCHES FROM SHERWOOD
TO MINOT...SOUTH TO CENTER AND INTO MOBRIDGE SOUTH DAKOTA. THIS
SURFACE TROUGH WILL SHIFT EAST DURING THE DAY REACHING THE JAMES
RIVER VALLEY LATE THIS AFTERNOON. ONCE THIS TROUGH EXITS THE JAMES
RIVER VALLEY EARLY THIS EVENING...EXPECT A BRIEF LULL IN THE
WIDESPREAD PRECIPITATION...ESSENTIALLY COVERING THE 00Z-06Z
THURSDAY TIME FRAME. HOWEVER POPS WILL ONCE AGAIN INCREASE ACROSS
THE SOUTH AND SOUTH CENTRAL TOWARD AND AFTER 06Z THURSDAY IN
RESPONSE TO THE VERTICAL MOTION FIELD AS THE CLOSED MID LEVEL LOW
APPROACHES. HAVE MAINTAINED THE TREND TO KEEP ANY MENTION OF
THUNDER SOUTH OF THE BORDER AS INSTABILITY PARAMETERS PER GFS
FOLLOW THIS TREND.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 324 AM CDT WED MAY 7 2014
AN UPPER LEVEL SHORTWAVE EMANATING FROM THE ROCKIES IS PROGGED TO
LIFT NORTH ACROSS THE CENTRAL AND NORTHERN PLAINS THURSDAY. THIS
FEATURE SHOULD GENERATE RAIN SHOWERS EXTENDING ALONG AND SOUTH OF
A LINE FROM HETTINGER TO BISMARCK TO HARVEY. HOWEVER...HIGH
PRESSURE BUILDING INTO EASTERN MONTANA SHOULD KEEP THE FORECAST
DRY FOR NORTHWESTERN NORTH DAKOTA.
A BREAK IN PRECIP CHANCES IS FORECAST FOR FRIDAY AS HIGH PRESSURE
CRESTS ACROSS THE REGION. TEMPERATURES ARE FORECAST TO GET IN THE
MID TO UPPER 60S FRIDAY.
PRECIPITATION CHANCES RETURN OVER NORTH DAKOTA SATURDAY AS A
SHORTWAVE EMANATING FROM THE PACIFIC NORTHWEST TRAVERSES THE
NORTHERN PLAINS.
THE MEDIUM RANGE MODELS DIVERGE WITH RESPECT TO THE UPPER PATTERN
OVER THE CONUS SUNDAY THROUGH THE REMAINDER OF THE PERIOD.
THEREFORE...THERE IS QUITE A BIT OF UNCERTAINTY REGARDING THE
FORECAST FOR THE FIRST HALF OF NEXT WEEK. EVEN THOUGH A PERSISTENT
UPPER LEVEL LOW OVER SASKATCHEWAN IS FORECAST TO MAINTAIN AN
UNSETTLED WEATHER REGIME OVER NORTH DAKOTA...THE MODELS HAVE BEEN
BACKING OFF ON PRECIP CHANCES/QPF AMOUNTS DUE TO DRY SLOTTING. AS
A RESULT...LOWERED POPS TO SLIGHT CHANCE/LOW-END CHANCE SUNDAY AND
MONDAY...AND REMOVED POPS FOR MOST OF THE CWA TUESDAY.
TEMPERATURES ARE STILL FORECAST TO REMAIN BELOW CLIMO VALUES THIS
WEEKEND THROUGH THE FIRST PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY)
ISSUED AT 1026 AM CDT WED MAY 7 2014
IFR/LIFR CONDITIONS AT KDIK AND KMOT IN RAIN...STRATUS AND FOG
WILL IMPROVE TO MVFR BY AFTERNOON. MVFR CONDITIONS IN RAIN WILL
BEGIN AT KBIS BY 16 UTC...AND CONTINUE THROUGH 19-20 UTC. RAIN
WILL APPROACH KJMS BY 18 UTC AND CONTINUE THROUGH 22-23 UTC. MVFR
CONDITIONS IN STRATUS ARE POSSIBLE AT KBIS/KJMS THEREAFTER.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...KS
LONG TERM...TM
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
826 AM CDT WED MAY 7 2014
.UPDATE...
ISSUED AT 826 AM CDT WED MAY 7 2014
QUICK UPDATE TO ADJUST POPS TO THE LATEST OBSERVED TRENDS THROUGH
13 UTC...INCORPORATING THE 11 UTC RAP/HRRR THROUGH THE REMAINDER
OF THE AFTERNOON AND EARLY EVENING. ALSO DECREASED CLOUD COVER
ACROSS THE NORTHWEST WHERE LOW TO MID LEVEL DECKS ARE THINNING
WHICH SHOULD LEAD TO AT LEAST PARTLY SUNNY SKIES.
UPDATE ISSUED AT 650 AM CDT WED MAY 7 2014
CURRENT RADAR OBS/TRENDS MATCH THE ONGOING FORECAST.
FURTHERMORE...THE LATEST HRRR MATCHES THE LATEST RADAR OBS AND
FORECAST TRENDS. WILL CONTINUE TO LEAN HEAVILY ON THE HRRR FOR
HOURLY POPS THROUGH THE AFTERNOON. OTHERWISE...THE CURRENT
FORECAST IS ON TRACK WITH NO MAJOR UPDATES REQUIRED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT WED MAY 7 2014
THE LATEST WATER VAPOR CONTINUES TO SHOW A MOIST SOUTHWEST FLOW
INTO NORTH DAKOTA WITH MULTIPLE SHORTWAVES AHEAD OF A MAIN UPPER
LOW NOW ALONG THE NEVADA/UTAH BORDER. THIS LOW WILL CLOSE OFF AND
PIVOT NORTHEAST THROUGH THE SHORT TERM PERIOD...AND WILL BECOME
THE MAIN PRECIPITATION PRODUCER OVER SOUTH CENTRAL NORTH DAKOTA
LATER WEDNESDAY NIGHT. UNTIL THEN...MODEL GUIDANCE SUGGESTING
SEVERAL AREAS OF RAIN SHOWERS WILL MOVE FROM SOUTHWEST TO
NORTHEAST TODAY AND THUS FAR LOCAL/REGIONAL RADAR CONFIRMS THIS.
OVERALL POPS ARE LIKELY TO CATEGORICAL FOR WESTERN AND MOST OF
CENTRAL NORTH DAKOTA TODAY...WITH THE JAMES RIVER VALLEY SEEING
HIGHEST POPS LATER THIS AFTERNOON AND AGAIN LATE WEDNESDAY NIGHT.
CATEGORICAL POPS HAVE BEEN PAINTED ALONG/NEAR A SURFACE INVERTED
TROUGH/BAROCLINIC ZONE...WHICH CURRENTLY STRETCHES FROM SHERWOOD
TO MINOT...SOUTH TO CENTER AND INTO MOBRIDGE SOUTH DAKOTA. THIS
SURFACE TROUGH WILL SHIFT EAST DURING THE DAY REACHING THE JAMES
RIVER VALLEY LATE THIS AFTERNOON. ONCE THIS TROUGH EXITS THE JAMES
RIVER VALLEY EARLY THIS EVENING...EXPECT A BRIEF LULL IN THE
WIDESPREAD PRECIPITATION...ESSENTIALLY COVERING THE 00Z-06Z
THURSDAY TIME FRAME. HOWEVER POPS WILL ONCE AGAIN INCREASE ACROSS
THE SOUTH AND SOUTH CENTRAL TOWARD AND AFTER 06Z THURSDAY IN
RESPONSE TO THE VERTICAL MOTION FIELD AS THE CLOSED MID LEVEL LOW
APPROACHES. HAVE MAINTAINED THE TREND TO KEEP ANY MENTION OF
THUNDER SOUTH OF THE BORDER AS INSTABILITY PARAMETERS PER GFS
FOLLOW THIS TREND.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 324 AM CDT WED MAY 7 2014
AN UPPER LEVEL SHORTWAVE EMANATING FROM THE ROCKIES IS PROGGED TO
LIFT NORTH ACROSS THE CENTRAL AND NORTHERN PLAINS THURSDAY. THIS
FEATURE SHOULD GENERATE RAIN SHOWERS EXTENDING ALONG AND SOUTH OF
A LINE FROM HETTINGER TO BISMARCK TO HARVEY. HOWEVER...HIGH
PRESSURE BUILDING INTO EASTERN MONTANA SHOULD KEEP THE FORECAST
DRY FOR NORTHWESTERN NORTH DAKOTA.
A BREAK IN PRECIP CHANCES IS FORECAST FOR FRIDAY AS HIGH PRESSURE
CRESTS ACROSS THE REGION. TEMPERATURES ARE FORECAST TO GET IN THE
MID TO UPPER 60S FRIDAY.
PRECIPITATION CHANCES RETURN OVER NORTH DAKOTA SATURDAY AS A
SHORTWAVE EMANATING FROM THE PACIFIC NORTHWEST TRAVERSES THE
NORTHERN PLAINS.
THE MEDIUM RANGE MODELS DIVERGE WITH RESPECT TO THE UPPER PATTERN
OVER THE CONUS SUNDAY THROUGH THE REMAINDER OF THE PERIOD.
THEREFORE...THERE IS QUITE A BIT OF UNCERTAINTY REGARDING THE
FORECAST FOR THE FIRST HALF OF NEXT WEEK. EVEN THOUGH A PERSISTENT
UPPER LEVEL LOW OVER SASKATCHEWAN IS FORECAST TO MAINTAIN AN
UNSETTLED WEATHER REGIME OVER NORTH DAKOTA...THE MODELS HAVE BEEN
BACKING OFF ON PRECIP CHANCES/QPF AMOUNTS DUE TO DRY SLOTTING. AS
A RESULT...LOWERED POPS TO SLIGHT CHANCE/LOW-END CHANCE SUNDAY AND
MONDAY...AND REMOVED POPS FOR MOST OF THE CWA TUESDAY.
TEMPERATURES ARE STILL FORECAST TO REMAIN BELOW CLIMO VALUES THIS
WEEKEND THROUGH THE FIRST PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 826 AM CDT WED MAY 7 2014
IFR/LIFR CONDITIONS AT KDIK AND KMOT IN RAIN...STRATUS AND FOG
WILL IMPROVE TO MVFR BY AFTERNOON. MVFR CONDITIONS IN RAIN WILL
BEGIN AT KBIS BY 16 UTC...AND CONTINUE THROUGH 19-20 UTC. RAIN
WILL APPROACH KJMS BY 18 UTC AND CONTINUE THROUGH 22-23 UTC. MVFR
CONDITIONS IN STRATUS ARE POSSIBLE AT KBIS/KJMS THEREAFTER.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...KS
LONG TERM...TM
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
650 AM CDT WED MAY 7 2014
.UPDATE...
ISSUED AT 650 AM CDT WED MAY 7 2014
CURRENT RADAR OBS/TRENDS MATCH THE ONGOING FORECAST.
FURTHERMORE...THE LATEST HRRR MATCHES THE LATEST RADAR OBS AND
FORECAST TRENDS. WILL CONTINUE TO LEAN HEAVILY ON THE HRRR FOR
HOURLY POPS THROUGH THE AFTERNOON. OTHERWISE...THE CURRENT
FORECAST IS ON TRACK WITH NO MAJOR UPDATES REQUIRED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT WED MAY 7 2014
THE LATEST WATER VAPOR CONTINUES TO SHOW A MOIST SOUTHWEST FLOW
INTO NORTH DAKOTA WITH MULTIPLE SHORTWAVES AHEAD OF A MAIN UPPER
LOW NOW ALONG THE NEVADA/UTAH BORDER. THIS LOW WILL CLOSE OFF AND
PIVOT NORTHEAST THROUGH THE SHORT TERM PERIOD...AND WILL BECOME
THE MAIN PRECIPITATION PRODUCER OVER SOUTH CENTRAL NORTH DAKOTA
LATER WEDNESDAY NIGHT. UNTIL THEN...MODEL GUIDANCE SUGGESTING
SEVERAL AREAS OF RAIN SHOWERS WILL MOVE FROM SOUTHWEST TO
NORTHEAST TODAY AND THUS FAR LOCAL/REGIONAL RADAR CONFIRMS THIS.
OVERALL POPS ARE LIKELY TO CATEGORICAL FOR WESTERN AND MOST OF
CENTRAL NORTH DAKOTA TODAY...WITH THE JAMES RIVER VALLEY SEEING
HIGHEST POPS LATER THIS AFTERNOON AND AGAIN LATE WEDNESDAY NIGHT.
CATEGORICAL POPS HAVE BEEN PAINTED ALONG/NEAR A SURFACE INVERTED
TROUGH/BAROCLINIC ZONE...WHICH CURRENTLY STRETCHES FROM SHERWOOD
TO MINOT...SOUTH TO CENTER AND INTO MOBRIDGE SOUTH DAKOTA. THIS
SURFACE TROUGH WILL SHIFT EAST DURING THE DAY REACHING THE JAMES
RIVER VALLEY LATE THIS AFTERNOON. ONCE THIS TROUGH EXITS THE JAMES
RIVER VALLEY EARLY THIS EVENING...EXPECT A BRIEF LULL IN THE
WIDESPREAD PRECIPITATION...ESSENTIALLY COVERING THE 00Z-06Z
THURSDAY TIME FRAME. HOWEVER POPS WILL ONCE AGAIN INCREASE ACROSS
THE SOUTH AND SOUTH CENTRAL TOWARD AND AFTER 06Z THURSDAY IN
RESPONSE TO THE VERTICAL MOTION FIELD AS THE CLOSED MID LEVEL LOW
APPROACHES. HAVE MAINTAINED THE TREND TO KEEP ANY MENTION OF
THUNDER SOUTH OF THE BORDER AS INSTABILITY PARAMETERS PER GFS
FOLLOW THIS TREND.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 324 AM CDT WED MAY 7 2014
AN UPPER LEVEL SHORTWAVE EMANATING FROM THE ROCKIES IS PROGGED TO
LIFT NORTH ACROSS THE CENTRAL AND NORTHERN PLAINS THURSDAY. THIS
FEATURE SHOULD GENERATE RAIN SHOWERS EXTENDING ALONG AND SOUTH OF
A LINE FROM HETTINGER TO BISMARCK TO HARVEY. HOWEVER...HIGH
PRESSURE BUILDING INTO EASTERN MONTANA SHOULD KEEP THE FORECAST
DRY FOR NORTHWESTERN NORTH DAKOTA.
A BREAK IN PRECIP CHANCES IS FORECAST FOR FRIDAY AS HIGH PRESSURE
CRESTS ACROSS THE REGION. TEMPERATURES ARE FORECAST TO GET IN THE
MID TO UPPER 60S FRIDAY.
PRECIPITATION CHANCES RETURN OVER NORTH DAKOTA SATURDAY AS A
SHORTWAVE EMANATING FROM THE PACIFIC NORTHWEST TRAVERSES THE
NORTHERN PLAINS.
THE MEDIUM RANGE MODELS DIVERGE WITH RESPECT TO THE UPPER PATTERN
OVER THE CONUS SUNDAY THROUGH THE REMAINDER OF THE PERIOD.
THEREFORE...THERE IS QUITE A BIT OF UNCERTAINTY REGARDING THE
FORECAST FOR THE FIRST HALF OF NEXT WEEK. EVEN THOUGH A PERSISTENT
UPPER LEVEL LOW OVER SASKATCHEWAN IS FORECAST TO MAINTAIN AN
UNSETTLED WEATHER REGIME OVER NORTH DAKOTA...THE MODELS HAVE BEEN
BACKING OFF ON PRECIP CHANCES/QPF AMOUNTS DUE TO DRY SLOTTING. AS
A RESULT...LOWERED POPS TO SLIGHT CHANCE/LOW-END CHANCE SUNDAY AND
MONDAY...AND REMOVED POPS FOR MOST OF THE CWA TUESDAY.
TEMPERATURES ARE STILL FORECAST TO REMAIN BELOW CLIMO VALUES THIS
WEEKEND THROUGH THE FIRST PART OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 650 AM CDT WED MAY 7 2014
WIDESPREAD RAIN SHOWERS WILL CONTINUE RESULTING IN IFR CIGS AND
MVFR VSBYS AT KDIK/KMOT THROUGH EARLY WEDNESDAY EVENING. ALTHOUGH
KISN WILL BEGIN WITH BORDERLINE IFR CIGS...EXPECT PRECIPITATION TO
END WITH CIGS IMPROVING TO VFR BY 15Z WEDNESDAY. AT KBIS...CIGS
WILL DETERIORATE TO MVFR BY 16Z WEDNESDAY AND REMAIN THERE THROUGH
12Z THURSDAY. KJMS WILL REMAIN VFR THROUGH WEDNESDAY
EVENING...THEN IFR CIGS AND MVFR VSBYS TAKE CONTROL BY 09Z
THURSDAY. NORTHERLY WINDS OF 15KT TO 25KT WILL SPREAD FROM WEST TO
EAST THROUGH THE TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...KS
LONG TERM...TM
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1150 PM CDT TUE MAY 6 2014
.UPDATE...
ISSUED AT 1150 PM CDT TUE MAY 6 2014
LOCAL/REGIONAL RADARS SHOWING AN AREA OF RAIN SHOWERS IN WESTERN
SOUTH DAKOTA HEADING NORTHEAST WITH TIME. THE HRRR MODEL CAPTURES
THIS AREA THE BEST AND SHIFTS IT INTO SOUTHWEST AND SOUTH CENTRAL
NORTH DAKOTA OVERNIGHT INTO MID MORNING WEDNESDAY. HAVE USED THIS
FOR THE POPS/PRECIPITATION FORECAST. STILL APPEARS THAT THE WEST
WILL REMAIN UNDER THE HIGHEST POPS FOR THE REST OF TUESDAY NIGHT
AND A PORTION OF WEDNESDAY...BEFORE THE MAIN SURGE OF SHOWERS
SHIFTS INTO CENTRAL NORTH DAKOTA WEDNESDAY NIGHT IN TANDEM WITH
APPROACH OF A MID LEVEL CLOSED CIRCULATION. CURRENT FORECAST HAS
THE NEAR TERM HANDLED WELL AND ONLY MINOR TWEAKS TO CURRENT
POPS/WEATHER.
UPDATE ISSUED AT 950 PM CDT TUE MAY 6 2014
LATEST RADAR IMAGERY SHOWS ISOLATED SHOWERS LIFTING NORTHEAST
ACROSS CENTRAL NORTH DAKOTA. MAIN SHOWER ACTIVITY REMAINS OVER
EASTERN MONTANA...WITH ANOTHER AREA OF SHOWERS LIFTING NORTHEAST
ACROSS FAR SOUTHEAST MONTANA INTO NORTHWEST SOUTH DAKOTA. HAVE
MADE SOME POP ADJUSTMENTS...KEEPING MAINLY SLIGHT CHANCE TO CHANCE
POPS THIS EVENING...AND THEN BRINGING HIGHER POPS FROM WEST TO
EAST LATE TONIGHT. CONVECTION HAS ENDED IN THE NORTHWEST AND THINK
THE CONVECTION OVER NORTHEAST WYOMING WILL HAVE A HARD TIME
MAINTAINING ITSELF AS IT MOVES CLOSER TO NORTH DAKOTA LATE THIS
EVENING. OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST.
UPDATE ISSUED AT 617 PM CDT TUE MAY 6 2014
UPDATE MAINLY TO BRING A MENTION OF SHOWERS AND THUNDER TO THE
NORTHWEST EARLY THIS EVENING. CONVERGENCE ALONG A WEAKENING COLD
FRONT MOVING INTO THE WESTERN DAKOTAS COMBINED WITH WEAK LOW LEVEL
INSTABILITY AND MODERATE SHEAR MOVING IN FROM THE WEST HAS
RESULTED IN AN AREA OF SHOWERS AND ONE THUNDERSTORM CELL THAT IS
CURRENTLY MOVING INTO THE FAR NORTHWEST. ISSUED A NOWCAST WITH A
MENTION OF SMALL HAIL...AFFECTING SOUTHWEST DIVIDE AND NORTHWEST
WILLIAMS...INCLUDING GRENORA. BUMPED UP POPS IN THE FAR NORTHWEST
THROUGH WEST CENTRAL EARLY THIS EVENING...AND LOWERED POPS ACROSS
THE CENTRAL...WITH ONLY SOME ISOLATED SHOWER ACTIVITY FROM BOWMAN
NORTHEAST THROUGH BISMARCK TO THE CARRINGTON AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 328 PM CDT TUE MAY 6 2014
PRECIPITATION POTENTIAL WILL HIGHLIGHT THE SHORT TERM FORECAST.
THINNING CLOUD COVER ACROSS NORTHWEST AND MUCH OF SOUTH CENTRAL AND
SOUTHEAST NORTH DAKOTA MAY LEAD TO ISOLATED TO SCATTERED SHOWER
DEVELOPMENT LATE THIS AFTERNOON AND INTO THE EARLY EVENING WITH
SUFFICIENT SURFACE DESTABILIZATION. THE FAR SOUTH CENTRAL NEAR THE
SOUTH DAKOTA BORDER AND NORTHWEST NORTH DAKOTA DO HAVE THE
POTENTIAL FOR THUNDERSTORMS WHERE MID LEVEL LAPSE RATES ARE
STEEPEST. AFTER SUNSET...RAIN SHOWER ACTIVITY IS EXPECTED TO
DECREASE IN COVERAGE UNTIL THE 06-08 UTC TIME FRAME WHEN
PRECIPITATION INCREASES ACROSS THE WEST WHEN THE BROADER AREA OF
PRECIPITATION ACROSS SOUTH CENTRAL THROUGH NORTHEAST MONTANA AS OF
20 UTC PROPAGATES EAST. WIDESPREAD RAIN SHOWER ACTIVITY WILL
CONTINUE THROUGHOUT WEDNESDAY ACROSS THE CENTRAL AND
SOUTHWEST...WITH A POTENTIAL DECREASE IN RAINFALL ACTIVITY NORTHWEST
AS THE WEAKENING SURFACE HIGH PROPAGATES IN. FINALLY...DID ADD A
MENTION OF PATCHY FOG TO MOST AREAS WITH STRATUS BUILD DOWN
TONIGHT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 PM CDT TUE MAY 6 2014
A PERSISTENT UPPER LEVEL LOW OVER NORTHERN SASKATCHEWAN WILL
GENERATE AN UNSETTLED WEATHER PATTERN OVER NORTH DAKOTA THROUGH
THE EXTENDED.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...THE AFOREMENTIONED LOW
COMBINED WITH A LONGWAVE TROUGH OVER THE ROCKIES WILL CONTRIBUTE TO
PERSISTENT RAIN SHOWER CHANCES OVER WESTERN AND CENTRAL NORTH DAKOTA
WEDNESDAY NIGHT...AND IN CENTRAL AND SOUTHWESTERN NORTH DAKOTA ON
THURSDAY...AND SOUTH CENTRAL NORTH DAKOTA THURSDAY NIGHT. THE MODEL
CONSENSUS CONTINUES TO INDICATE THE HIGHEST RAINFALL AMOUNTS OVER
SOUTH CENTRAL NORTH DAKOTA...WITH AREAS ALONG AND SOUTHEAST OF A
LINE FROM SIOUX AND GRANT COUNTY TO BISMARCK/MANDAN TO CARRINGTON
RECEIVING ANYWHERE FROM 1/2 INCH TO NEARLY 1 INCH IN THIS 36-HOUR
PERIOD.
PRECIPITATION TOTALS FROM TUESDAY NIGHT THROUGH THURSDAY
NIGHT...AREAS ALONG AND SOUTHEAST OF A BOWMAN TO DICKINSON...TO
GARRISON TO RUGBY MAY EXPECT ANYWHERE FROM 1/2 INCH TO 1 1/4 INCHES
OF PRECIPITATION.
A BREAK IN PRECIP CHANCES IS FORECAST FOR FRIDAY AS A WEAK
SHORTWAVE RIDGE SNEAKS UNDER THE PERSISTENT SASKATCHEWAN LOW.
TEMPERATURES ARE EXPECTED TO REACH INTO THE 60S FRIDAY.
THE SASKATCHEWAN LOW IS THEN PROGGED TO USHER IN SHORTWAVE AFTER
SHORTWAVE OVER NORTH DAKOTA THROUGH THE REMAINDER OF THE EXTENDED.
DUE TO TIMING/INTENSITY UNCERTAINTIES...BROADBRUSHED CHANCE POPS
OVER THE FORECAST AREA SATURDAY THROUGH TUESDAY. TEMPERATURES WILL
LIKELY REMAIN BELOW NORMAL...MAINLY HIGHS IN THE 50S...WITH THE
UNSETTLED WEATHER PATTERN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1150 PM CDT TUE MAY 6 2014
AN AREA OF IFR CIGS WILL EXPAND ACROSS THE WEST THROUGH 12Z
IMPACTING KISN/KDIK. IN COMBINATION WITH THE LOWERING CIGS WEST WILL
BE AN AREA OF RAIN SHOWERS MOVING NORTHEAST FROM WESTERN SOUTH
DAKOTA. THIS WILL SLIDE INTO KDIK AND KBIS BEFORE 12Z WEDNESDAY.
LIGHT RAIN SHOWERS WILL CONTINUE AT KISN AS MOISTURE IS REPLENISHED
IN EASTERN MONTANA AND MOVING NORTHEAST WITH TIME. IFR CIGS AND MVFR
VSBYS CAN BE EXPECTED AT KMOT/KDIK FROM AROUND 12Z TUESDAY THROUGH
06Z WEDNESDAY. MVFR CIGS ARE FORECAST FOR KBIS. KJMS WILL REMAIN VFR
UNTIL 03Z WEDNESDAY...AS THE BULK OF THE STEADY RAIN SHOWERS ARRIVE
AFTER 06Z THURSDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...AYD
LONG TERM...JV
AVIATION...KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
652 AM EDT WED MAY 7 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH THROUGH THE OHIO VALLEY
TODAY...ALLOWING FOR TEMPERATURES WELL ABOVE NORMAL TODAY AND
THURSDAY. SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE AREA ON
FRIDAY AND SATURDAY...AS A COLD FRONT SLOWLY MOVES EAST THROUGH THE
REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A RATHER HEALTHY BAND OF CONVECTION HAS DEVELOPED IN SOUTHERN
MICHIGAN AND NORTHWESTERN OHIO...ALONG AN AXIS GENERALLY PARALLEL
TO (BUT A COUPLE HUNDRED MILES REMOVED FROM) THE SURFACE WARM
FRONT. OBVIOUSLY ELEVATED IN NATURE...THIS CONVECTION IS ON A
TRAJECTORY TO MISS THE ILN FORECAST AREA ENTIRELY. JUST A SLIGHT
CHANCE OF A SHOWER HAS BEEN KEPT IN THE FAR NORTHERN/NORTHEASTERN
ILN COUNTIES FOR A FEW HOURS.
RIDGING IS ALREADY BUILDING INTO THE FORECAST AREA...WITH 925MB
TEMPERATURES ALREADY BEGINNING TO RISE. THE ACTUAL SURFACE WARM
FRONT WILL CROSS THE CWA FROM SOUTH TO NORTH BETWEEN EARLY THIS
MORNING AND AROUND 18Z...SHIFTING FLOW TO THE SOUTHWEST THROUGH
THE COLUMN...SETTING UP A FAVORABLE WARM ADVECTION PATTERN. ALL
SIGNS POINT TO A WELL MIXED BOUNDARY LAYER TODAY...WHICH SHOULD
ALLOW FOR A SIGNIFICANT WARMING IN TEMPERATURES TO THE LOWER TO
MID 80S...AS WELL AS WIND GUSTS INTO THE 20-30 MPH RANGE.
RECORD HIGHS FOR TODAY (MAY 7) APPEAR TO BE SAFE.
CMH: 87 / 1936
DAY: 87 / 1926 AND 1897
CVG: 89 / 1940
ONLY THE RAP (WITH ITS OVER-MIXED BOUNDARY LAYER TENDENCIES) HAD
VALUES ANYWHERE NEAR THOSE NUMBERS. THIS FORECAST WILL STAY A FEW
DEGREES BELOW THE RAP...BUT ON THE HIGHER SIDE OF THE REST OF THE
GUIDANCE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
CONTINUED SOUTHWESTERLY FLOW WILL LEAD TO MILD CONDITIONS
TONIGHT...BEFORE ANOTHER VERY WARM DAY IS EXPECTED ON THURSDAY.
THE OVERALL WEATHER PATTERN WILL BE CHANGING VERY LITTLE...WITH
MID-LEVEL RIDGING OVER THE OHIO VALLEY (EXTENDING FROM THE
SOUTHEASTERN STATES). ANOTHER WELL-MIXED DAY WITH APPRECIABLE
AMOUNTS OF SUN WILL LEAD TO SIMILAR TEMPERATURES TO
WEDNESDAY...PERHAPS EVEN A FEW DEGREES WARMER. RECORD HIGHS FOR
ALL THREE CLIMATE SITES ARE 89 DEGREES FOR MAY 8...AND
AGAIN AS ON WEDNESDAY...THESE LOOK TO BE SAFE.
GOING INTO FRIDAY...A BROAD UPPER TROUGH WILL BE MOVING
NORTHEAST FROM THE PLAINS INTO CANADA...WITH A SURFACE LOW
FORECAST TO RIDE ALONG THE TROUGH THROUGH MINNESOTA AND INTO
NORTHERN ONTARIO. A COLD FRONT WILL EXTEND FROM SOUTH OF THIS LOW
AND WILL MOVE INTO THE OHIO VALLEY ON FRIDAY. WITH THE LOW SO FAR
AWAY FROM THE REGION...AND THE MID-LEVEL FLOW FAILING TO BECOME
PARTICULARLY SHARP...THERE IS LITTLE IMPETUS FOR THE FRONT TO
MAINTAIN ITS STRENGTH AS IT LUMBERS EASTWARD. THIS SETS UP
FORECAST WITH SPECIFICS THAT REMAIN RATHER UNCERTAIN...WITH
CONCERNS OF TIMING AND FORCING STRENGTH PRECLUDING ANY HIGHER THAN
70-PERCENT POPS DURING THE SPAN FROM FRIDAY THROUGH SATURDAY (EVEN
THOUGH IT IS VERY LIKELY THAT THE ENTIRE CWA WILL GET SOME RAIN
OUT OF THIS SYSTEM). THE FIRST WAVE AHEAD OF THE FRONT (MOVING
INTO THE ILN CWA ON FRIDAY MORNING) APPEARS TO FALL APART AS IT
GETS TOO FAR AHEAD OF THE SURFACE TROUGH...AND THE BIGGEST
QUESTION WITH THE SECOND WAVE IS THE TIMING (WITH A FEW MODELS NOW
SHOWING THIS MORE AS A FRIDAY NIGHT ISSUE THAN A SATURDAY ONE).
WITH QUESTIONABLE LOW-LEVEL MOISTURE ON FRIDAY (LIMITING
INSTABILITY)...AND THE WEAK FORCING AND SLOW FRONTAL MOTION ALSO
FACTORED IN...THE THREAT FOR STRONG STORMS APPEARS RATHER LOW. THE
PLACEMENT OF THE SECOND WAVE WILL END UP DETERMINING IF ANY CHANCE
FOR HEAVY OR PROLONGED RAIN MIGHT LEAD TO A POSSIBILITY OF
FLOODING...BUT THIS ALSO APPEARS TO BE A LOW-END THREAT.
TEMPERATURES WILL ALSO BE HELD DOWN BY THE OCCASIONAL RAIN AND
PERSISTENT CLOUD COVER...WITH A GRADIENT FROM THE MID 70S (NW CWA)
TO NEAR 80 (SE CWA) ON FRIDAY...THEN NEAR 70 DEGREES EXPECTED ON
SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
MODEL SOLUTIONS DIVERGE THEREAFTER. ELECTED TO GO CLOSER TO THE
ECMWF WHICH...AFTER AN INTERLUDE OF SOMEWHAT DRIER CONDITIONS ON
SUNDAY AND MONDAY...BRINGS THE NEXT COLD FRONT CONTAINING A CHANCE
OF THUNDERSTORMS ON TUESDAY.
EXPECT HIGH TEMPERATURES PRIMARILY IN THE 70S. THE EXCEPTION MAY BE
ON MONDAY...WHEN WARM ADVECTION MAY PUSH READINGS INTO THE LOWER
80S.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
A MID LEVEL RIDGE WILL BUILD NORTH INTO THE SOUTHERN GREAT LAKES
TODAY. AS THIS OCCURS...A WARM FRONT WILL LIFT NORTH ACROSS THE
REGION THIS MORNING.
FOR THIS AFTERNOON...REGION WILL BE LOCATED IN THE WARM SECTOR.
DAYTIME MIXING WILL RESULT IN SOUTHERLY WINDS IN THE 10 TO 15 KNOT
RANGE WITH GUSTS GENERALLY IN THE 20 TO 25 KNOT RANGE. MAINLY HIGH
LEVEL CLOUDS WILL THIN SOME BY AFTERNOON.
FOR TONIGHT...MID LEVEL RIDGE WILL REMAIN IN PLACE WITH MOSTLY
CLEAR SKIES EXPECTED.
OUTLOOK...THUNDERSTORMS POSSIBLE FRIDAY INTO SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
418 AM EDT WED MAY 7 2014
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH THROUGH THE OHIO VALLEY
TODAY...ALLOWING FOR TEMPERATURES WELL ABOVE NORMAL TODAY AND
THURSDAY. SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE AREA ON
FRIDAY AND SATURDAY...AS A COLD FRONT SLOWLY MOVES EAST THROUGH THE
REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A RATHER HEALTHY BAND OF CONVECTION HAS DEVELOPED IN SOUTHERN
MICHIGAN AND NORTHWESTERN OHIO...ALONG AN AXIS GENERALLY PARALLEL
TO (BUT A COUPLE HUNDRED MILES REMOVED FROM) THE SURFACE WARM
FRONT. OBVIOUSLY ELEVATED IN NATURE...THIS CONVECTION IS ON A
TRAJECTORY TO MISS THE ILN FORECAST AREA ENTIRELY. JUST A SLIGHT
CHANCE OF A SHOWER HAS BEEN KEPT IN THE FAR NORTHERN/NORTHEASTERN
ILN COUNTIES FOR A FEW HOURS.
RIDGING IS ALREADY BUILDING INTO THE FORECAST AREA...WITH 925MB
TEMPERATURES ALREADY BEGINNING TO RISE. THE ACTUAL SURFACE WARM
FRONT WILL CROSS THE CWA FROM SOUTH TO NORTH BETWEEN EARLY THIS
MORNING AND AROUND 18Z...SHIFTING FLOW TO THE SOUTHWEST THROUGH
THE COLUMN...SETTING UP A FAVORABLE WARM ADVECTION PATTERN. ALL
SIGNS POINT TO A WELL MIXED BOUNDARY LAYER TODAY...WHICH SHOULD
ALLOW FOR A SIGNIFICANT WARMING IN TEMPERATURES TO THE LOWER TO
MID 80S...AS WELL AS WIND GUSTS INTO THE 20-30 MPH RANGE.
RECORD HIGHS FOR TODAY (MAY 7) APPEAR TO BE SAFE.
CMH: 87 / 1936
DAY: 87 / 1926 AND 1897
CVG: 89 / 1940
ONLY THE RAP (WITH ITS OVER-MIXED BOUNDARY LAYER TENDENCIES) HAD
VALUES ANYWHERE NEAR THOSE NUMBERS. THIS FORECAST WILL STAY A FEW
DEGREES BELOW THE RAP...BUT ON THE HIGHER SIDE OF THE REST OF THE
GUIDANCE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
CONTINUED SOUTHWESTERLY FLOW WILL LEAD TO MILD CONDITIONS
TONIGHT...BEFORE ANOTHER VERY WARM DAY IS EXPECTED ON THURSDAY.
THE OVERALL WEATHER PATTERN WILL BE CHANGING VERY LITTLE...WITH
MID-LEVEL RIDGING OVER THE OHIO VALLEY (EXTENDING FROM THE
SOUTHEASTERN STATES). ANOTHER WELL-MIXED DAY WITH APPRECIABLE
AMOUNTS OF SUN WILL LEAD TO SIMILAR TEMPERATURES TO
WEDNESDAY...PERHAPS EVEN A FEW DEGREES WARMER. RECORD HIGHS FOR
ALL THREE CLIMATE SITES ARE 89 DEGREES FOR MAY 8...AND
AGAIN AS ON WEDNESDAY...THESE LOOK TO BE SAFE.
GOING INTO FRIDAY...A BROAD UPPER TROUGH WILL BE MOVING
NORTHEAST FROM THE PLAINS INTO CANADA...WITH A SURFACE LOW
FORECAST TO RIDE ALONG THE TROUGH THROUGH MINNESOTA AND INTO
NORTHERN ONTARIO. A COLD FRONT WILL EXTEND FROM SOUTH OF THIS LOW
AND WILL MOVE INTO THE OHIO VALLEY ON FRIDAY. WITH THE LOW SO FAR
AWAY FROM THE REGION...AND THE MID-LEVEL FLOW FAILING TO BECOME
PARTICULARLY SHARP...THERE IS LITTLE IMPETUS FOR THE FRONT TO
MAINTAIN ITS STRENGTH AS IT LUMBERS EASTWARD. THIS SETS UP
FORECAST WITH SPECIFICS THAT REMAIN RATHER UNCERTAIN...WITH
CONCERNS OF TIMING AND FORCING STRENGTH PRECLUDING ANY HIGHER THAN
70-PERCENT POPS DURING THE SPAN FROM FRIDAY THROUGH SATURDAY (EVEN
THOUGH IT IS VERY LIKELY THAT THE ENTIRE CWA WILL GET SOME RAIN
OUT OF THIS SYSTEM). THE FIRST WAVE AHEAD OF THE FRONT (MOVING
INTO THE ILN CWA ON FRIDAY MORNING) APPEARS TO FALL APART AS IT
GETS TOO FAR AHEAD OF THE SURFACE TROUGH...AND THE BIGGEST
QUESTION WITH THE SECOND WAVE IS THE TIMING (WITH A FEW MODELS NOW
SHOWING THIS MORE AS A FRIDAY NIGHT ISSUE THAN A SATURDAY ONE).
WITH QUESTIONABLE LOW-LEVEL MOISTURE ON FRIDAY (LIMITING
INSTABILITY)...AND THE WEAK FORCING AND SLOW FRONTAL MOTION ALSO
FACTORED IN...THE THREAT FOR STRONG STORMS APPEARS RATHER LOW. THE
PLACEMENT OF THE SECOND WAVE WILL END UP DETERMINING IF ANY CHANCE
FOR HEAVY OR PROLONGED RAIN MIGHT LEAD TO A POSSIBILITY OF
FLOODING...BUT THIS ALSO APPEARS TO BE A LOW-END THREAT.
TEMPERATURES WILL ALSO BE HELD DOWN BY THE OCCASIONAL RAIN AND
PERSISTENT CLOUD COVER...WITH A GRADIENT FROM THE MID 70S (NW CWA)
TO NEAR 80 (SE CWA) ON FRIDAY...THEN NEAR 70 DEGREES EXPECTED ON
SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
MODEL SOLUTIONS DIVERGE THEREAFTER. ELECTED TO GO CLOSER TO THE
ECMWF WHICH...AFTER AN INTERLUDE OF SOMEWHAT DRIER CONDITIONS ON
SUNDAY AND MONDAY...BRINGS THE NEXT COLD FRONT CONTAINING A CHANCE
OF THUNDERSTORMS ON TUESDAY.
EXPECT HIGH TEMPERATURES PRIMARILY IN THE 70S. THE EXCEPTION MAY BE
ON MONDAY...WHEN WARM ADVECTION MAY PUSH READINGS INTO THE LOWER
80S.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
A MID LEVEL RIDGE WILL BUILD NORTH INTO THE SOUTHERN GREAT LAKES
TODAY. AS THIS OCCURS...A WARM FRONT WILL LIFT NORTH ACROSS THE
REGION THIS MORNING. THERE MAY BE ENOUGH LIFT/ASCENT AHEAD OF THE
FRONT FOR AN ISOLATED SHOWER/THUNDERSTORM NEAR THE KCMH/KLCK
TERMINALS. GIVEN THE LOW PROBABILITY...THE TAFS WILL BE KEPT DRY.
FOR THIS AFTERNOON...REGION WILL BE LOCATED IN THE WARM SECTOR.
DAYTIME MIXING WILL RESULT IN SOUTHERLY WINDS IN THE 10 TO 15 KNOT
RANGE WITH GUSTS GENERALLY IN THE 20 TO 25 KNOT RANGE. MAINLY HIGH
LEVEL CLOUDS WILL THIN SOME BY AFTERNOON.
FOR TONIGHT...MID LEVEL RIDGE WILL REMAIN IN PLACE WITH MOSTLY
CLEAR SKIES EXPECTED.
OUTLOOK...THUNDERSTORMS POSSIBLE FRIDAY INTO SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...CONIGLIO
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1033 PM CDT THU MAY 8 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 441 PM CDT THU MAY 8 2014
CURRENT SURFACE ANALYSIS INDICATING THE SURFACE LOW PRESSURE CENTER
LOCATED OVER NORTHEASTERN NEBRASKA INTO NORTHWESTERN IOWA...WITH A
WARM FRONT EXTENDING EASTWARD TO JUST SOUTH OF WORTHINGTON AND
JACKSON MINNESOTA. EARLIER ROUND OF CONVECTION STABILIZED THE
ATMOSPHERE A BIT...BUT WITH BREAKS IN THE CLOUD COVER THROUGH THE
AFTERNOON...INSTABILITY HAS RECOVERED INTO THE RANGE OF 1000 TO 2000
J/KG PER SPC MISANALYSED. BOTH THE RAP13 AND HRRR MODELS INDICATE
THUNDERSTORM REDEVELOPMENT POSSIBLE ACROSS NORTHWEST IOWA OVER THE
NEXT COUPLE OF HOURS...AND WITH VERY STRONG SHEAR ACROSS THE AREA
WOULD EXPECT SOME OF THESE STORMS BECOMING SEVERE WITH VERY LARGE
HAIL...DAMAGING WINDS...AND EVEN AN ISOLATED TORNADO IN THE VICINITY
OF THE FRONTAL BOUNDARY. AS THE LOW PRESSURE MOVES TO NORTH AND
EAST...ANY SEVERE CONVECTION WILL WIND DOWN PRETTY QUICKLY AFTER 00Z
WITH MAINLY SOME WRAP AROUND SHOWERS ACROSS OUR NORTH OVERNIGHT.
WITH COOLER AIR FILTERING IN BEHIND THE SYSTEM...LOWS LOOK TO DROP
DOWN INTO THE MID 30S FAR WEST TO MID 40S IN THE FAR EAST.
OTHER THAN SOME MORNING SHOWERS IN OUR NORTHEAST...THE REMAINDER OF
FRIDAY SHOULD BE DECENT WITH DECREASING CLOUDS AND HIGHS IN THE 60S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 441 PM CDT THU MAY 8 2014
FOR SURE ONE OF THE MOST QUIET PERIODS IN THE FORECAST SHOULD BE
FRIDAY EVENING. WEAK RIDGE WILL SHIFT EASTWARD DURING THE EVENING...
WITH MID LEVEL WARM AIR ADVECTION INCREASING AS WAVE PUSHES INTO
THE WESTERN HIGH PLAINS BY LATE NIGHT. INSTABILITY IS PRETTY
MEAGER...AND WILL HAVE TO WORK INTO A FAIRLY DRIER ATMOSPHERE
TO START. WILL KEEP COVERAGE ISOLATED TO PERHAPS SCATTERED
AFTER 06Z...WITH BEST CHANCES SNEAKING IN LATE. THE FOCUS FOR
PRECIPITATION WILL BECOME SOMEWHAT BETTER HEADING THROUGH THE
DAY AND HEADING NORTHEASTWARD ON SATURDAY...PERHAPS PEAKING MIDDAY
OR EARLY AFTERNOON IN THE FAR EAST/NORTHEAST. ENOUGH STEEPENING
OF THE MID LEVEL LAPSE RATES AS DRIER AIR ALOFT WORKS TO THE SOUTH
OF MID LEVEL WAVE TO THE NORTH TO WARRANT A SOMEWHAT BETTER
MENTION OF THUNDER.
WAVE LIFTS PAST FAIRLY QUICKLY SHEARING NORTHEAST ON SATURDAY
EVENING WITH PERHAPS A LITTLE LINGERING SHOWER/THUNDER ACTIVITY
IN THE EASTERN CWA...WITH COLD FRONT PUSHING ACROSS THE CWA.
SHOULD GET A DECENT DRY PUSH ACROSS THE CWA DURING THE EVENING
WITH A FAIRLY SUBSIDENT QUADRANT OF UPPER WAVE INTO CWA. START TO
GET A DRASTIC DIVERGENCE IN MODEL SOLUTIONS AS EARLY AS SATURDAY
NIGHT AND SUNDAY. HEADING INTO THE EXTENDED PORTION OF THE
FORECAST FOR MONDAY THROUGH THURSDAY...HAVE SIDED TOWARD MORE
AMPLIFIED AND SLOWER SOLUTION TO START WHICH MEANS HANGING BACK
BETTER CHANCE FOR RAINFALL ON MONDAY...ESPECIALLY THE SOUTHEAST
HALF. SUCH A DEEPER SYSTEM PER ENSEMBLE HINTS AND ECMWF LOOKS
MORE FAVORED WITH LONG WAVE PATTERN SETTING UP AND THIS WILL START
TO REBUILD THE RIDGE ACROSS THE NORTHERN PLAINS BY LATE WEEKEND.
THIS SHOULD ENHANCE THE LIFT ACROSS STALLING LOWER TO MID LEVEL
BOUNDARY. MAIN TROUGH LIFTING NORTHEAST THROUGH THE WESTERN AND
NORTHERN PLAINS SHOULD PRODUCE ANOTHER PULSE OF MID LEVEL LIFT
ACROSS THE LOW LEVEL ON SUNDAY NIGHT INTO MONDAY. COOLER AND DRYING
FOR MONDAY NIGHT THROUGH TUESDAY NIGHT...AND THEN SOME ORIENTATION
OF TROUGHINESS AGAIN BY WEDNESDAY INTO THURSDAY...BUT NOT ENOUGH
AGREEMENT TO TRULY DEFINE A MORE CERTAIN THREAT FOR RAINFALL. DOES
APPEAR THAT A PERIOD OF COOLER THAN NORMAL READINGS WILL BE IN
PLACE AFTER SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1030 PM CDT THU MAY 8 2014
IFR TO LOW END MVFR CEILINGS TO PERSIST THROUGH MUCH OF THE NIGHT
BUT TOWARDS SUNRISE AND SHORTLY AFTER THE CEILINGS ARE EXPECTED TO
DISSIPATE GIVING WAY TO VFR CONDITIONS ON FRIDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...CHAPMAN
AVIATION...08
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
627 PM CDT THU MAY 8 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 441 PM CDT THU MAY 8 2014
CURRENT SURFACE ANALYSIS INDICATING THE SURFACE LOW PRESSURE CENTER
LOCATED OVER NORTHEASTERN NEBRASKA INTO NORTHWESTERN IOWA...WITH A
WARM FRONT EXTENDING EASTWARD TO JUST SOUTH OF WORTHINGTON AND
JACKSON MINNESOTA. EARLIER ROUND OF CONVECTION STABILIZED THE
ATMOSPHERE A BIT...BUT WITH BREAKS IN THE CLOUD COVER THROUGH THE
AFTERNOON...INSTABILITY HAS RECOVERED INTO THE RANGE OF 1000 TO 2000
J/KG PER SPC MISANALYSED. BOTH THE RAP13 AND HRRR MODELS INDICATE
THUNDERSTORM REDEVELOPMENT POSSIBLE ACROSS NORTHWEST IOWA OVER THE
NEXT COUPLE OF HOURS...AND WITH VERY STRONG SHEAR ACROSS THE AREA
WOULD EXPECT SOME OF THESE STORMS BECOMING SEVERE WITH VERY LARGE
HAIL...DAMAGING WINDS...AND EVEN AN ISOLATED TORNADO IN THE VICINITY
OF THE FRONTAL BOUNDARY. AS THE LOW PRESSURE MOVES TO NORTH AND
EAST...ANY SEVERE CONVECTION WILL WIND DOWN PRETTY QUICKLY AFTER 00Z
WITH MAINLY SOME WRAP AROUND SHOWERS ACROSS OUR NORTH OVERNIGHT.
WITH COOLER AIR FILTERING IN BEHIND THE SYSTEM...LOWS LOOK TO DROP
DOWN INTO THE MID 30S FAR WEST TO MID 40S IN THE FAR EAST.
OTHER THAN SOME MORNING SHOWERS IN OUR NORTHEAST...THE REMAINDER OF
FRIDAY SHOULD BE DECENT WITH DECREASING CLOUDS AND HIGHS IN THE 60S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 441 PM CDT THU MAY 8 2014
FOR SURE ONE OF THE MOST QUIET PERIODS IN THE FORECAST SHOULD BE
FRIDAY EVENING. WEAK RIDGE WILL SHIFT EASTWARD DURING THE EVENING...
WITH MID LEVEL WARM AIR ADVECTION INCREASING AS WAVE PUSHES INTO
THE WESTERN HIGH PLAINS BY LATE NIGHT. INSTABILITY IS PRETTY
MEAGER...AND WILL HAVE TO WORK INTO A FAIRLY DRIER ATMOSPHERE
TO START. WILL KEEP COVERAGE ISOLATED TO PERHAPS SCATTERED
AFTER 06Z...WITH BEST CHANCES SNEAKING IN LATE. THE FOCUS FOR
PRECIPITATION WILL BECOME SOMEWHAT BETTER HEADING THROUGH THE
DAY AND HEADING NORTHEASTWARD ON SATURDAY...PERHAPS PEAKING MIDDAY
OR EARLY AFTERNOON IN THE FAR EAST/NORTHEAST. ENOUGH STEEPENING
OF THE MID LEVEL LAPSE RATES AS DRIER AIR ALOFT WORKS TO THE SOUTH
OF MID LEVEL WAVE TO THE NORTH TO WARRANT A SOMEWHAT BETTER
MENTION OF THUNDER.
WAVE LIFTS PAST FAIRLY QUICKLY SHEARING NORTHEAST ON SATURDAY
EVENING WITH PERHAPS A LITTLE LINGERING SHOWER/THUNDER ACTIVITY
IN THE EASTERN CWA...WITH COLD FRONT PUSHING ACROSS THE CWA.
SHOULD GET A DECENT DRY PUSH ACROSS THE CWA DURING THE EVENING
WITH A FAIRLY SUBSIDENT QUADRANT OF UPPER WAVE INTO CWA. START TO
GET A DRASTIC DIVERGENCE IN MODEL SOLUTIONS AS EARLY AS SATURDAY
NIGHT AND SUNDAY. HEADING INTO THE EXTENDED PORTION OF THE
FORECAST FOR MONDAY THROUGH THURSDAY...HAVE SIDED TOWARD MORE
AMPLIFIED AND SLOWER SOLUTION TO START WHICH MEANS HANGING BACK
BETTER CHANCE FOR RAINFALL ON MONDAY...ESPECIALLY THE SOUTHEAST
HALF. SUCH A DEEPER SYSTEM PER ENSEMBLE HINTS AND ECMWF LOOKS
MORE FAVORED WITH LONG WAVE PATTERN SETTING UP AND THIS WILL START
TO REBUILD THE RIDGE ACROSS THE NORTHERN PLAINS BY LATE WEEKEND.
THIS SHOULD ENHANCE THE LIFT ACROSS STALLING LOWER TO MID LEVEL
BOUNDARY. MAIN TROUGH LIFTING NORTHEAST THROUGH THE WESTERN AND
NORTHERN PLAINS SHOULD PRODUCE ANOTHER PULSE OF MID LEVEL LIFT
ACROSS THE LOW LEVEL ON SUNDAY NIGHT INTO MONDAY. COOLER AND DRYING
FOR MONDAY NIGHT THROUGH TUESDAY NIGHT...AND THEN SOME ORIENTATION
OF TROUGHINESS AGAIN BY WEDNESDAY INTO THURSDAY...BUT NOT ENOUGH
AGREEMENT TO TRULY DEFINE A MORE CERTAIN THREAT FOR RAINFALL. DOES
APPEAR THAT A PERIOD OF COOLER THAN NORMAL READINGS WILL BE IN
PLACE AFTER SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 627 PM CDT THU MAY 8 2014
STORMS WILL MOVE EAST OF THE EXTREME EASTERN PART OF THE FORECAST
AREA BY 03Z. OTHERWISE WIDESPREAD LOW CLOUDS WEST OF SYSTEM WILL
BRING CEILINGS 1-2K FEET TONIGHT WITH AREAS OF CEILINGS BELOW 1K
FEET. A FEW AREAS OF VISIBILITY 3-5SM AND LOCALLY 1-3SM IN LIGHT
RAIN AND FOG THROUGH 06Z MAINLY NORTH OF INTERSTATE 90. CLEARING
TO VFR WITH UNLIMITED CEILINGS WILL TAKE PLACE FROM WEST TO EAST
09Z-18Z...THIS CLEARING WILL REACH WRN MN AND WRN IA 12Z-15Z. VFR
WILL THEN CONTINUE THROUGH 10/00Z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...CHAPMAN
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
339 PM CDT WED MAY 7 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 311 PM CDT WED MAY 7 2014
CURRENT SURFACE ANALYSIS SHOWING A SURFACE TROUGH AXIS LOCATED
THROUGH NORTHWESTERN IOWA WITH A WARM FRONT EXTENDING EASTWARD
ACROSS THAT AREA. HAVE SEEN SOME SCATTERED CONVECTION DEVELOP
THROUGH THE NORTHERN JAMES RIVER VALLEY ALONG THE EDGE OF A STRONG
CAP LOCATED ACROSS MOST OF THE REST OF THE CWA PER SPC
MESOANALYSIS...WITH THIS CONVECTION TRENDING OFF TO THE NORTHEAST AT
THIS TIME. THE RAP13 HAS HANDLED CONVECTIVE TRENDS FAIRLY WELL
THROUGH THE DAY...WITH THE HRRR LESS SO...AND THE RAP AS WELL AS A
COUPLE HI RES MODELS INDICATING ADDITIONAL CONVECTIVE DEVELOPMENT
SOMEWHERE IN THE VICINITY OF THE IOWA GREAT LAKES/PORTIONS OF
SOUTHWESTERN MINNESOTA IN THE LATE AFTERNOON/EARLY EVENING...IF THE
CAP CAN BE BROKEN. SOUNDINGS WOULD SUGGEST THIS TO BE A POSSIBILITY
BY LATE AFTERNOON AS A WEAK MID LEVEL WAVE TRACKS THROUGH THE
REGION. IF THIS WERE TO OCCUR...PRESENT INSTABILITY AND EFFECTIVE
SHEAR VALUES RUNNING AROUND 40 KTS WOULD INDICATE THAT SEVERE STORMS
WOULD BE POSSIBLE WITH LARGE HAIL BEING THE MAIN THREAT.
OTHERWISE...THE FOCUS FOR ADDITIONAL CONVECTION OVERNIGHT MAY BE
CLOSER TO THE MID LEVEL FRONT ORIENTED FROM SOUTH CENTRAL SOUTH
DAKOTA THEN CURVING NORTHWARD INTO NORTHEASTERN SOUTH DAKOTA.
OTHERWISE...SHORTER TERM MODELS ALSO HINTING CONVECTION DEVELOPING
THROUGH SOUTHERN NEBRASKA...POSSIBLY WORKING NORTHWARD INTO PORTIONS
OF OUR SOUTHERN CWA LATE TONIGHT...THOUGH MUCH UNCERTAINTY ON THIS
SCENARIO WITH MODEL DIFFERENCES. THERE WILL BE A WIDE RANGE OF
TEMPERATURES ACROSS THE AREA TONIGHT...WITH COOL UPPER 40S IN OUR
FAR WEST ON THE BACKSIDE OF THE LOW PRESSURE...WHILE DROPPING ONLY
INTO THE LOWER 60S THROUGH NORTHWESTERN IOWA WHICH WILL REMAIN IN
THE WARM SECTOR OF THE SYSTEM.
MODELS IN FAIRLY DECENT AGREEMENT ON THE SURFACE LOW PULLING INTO
SOUTHWESTERN MINNESOTA BY THURSDAY EVENING...THOUGH DIFFERING ON
STRENGTH AND DURATION OF THE DRY SLOT ACROSS OUR AREA. THE NAM/GEM
ARE MORE AGGRESSIVE WITH THIS FEATURE...KEEPING OUR EAST FAIRLY DRY
THROUGH MUCH OF THE DAY...THROUGH THE GFS/ECMWF OFFER A WETTER
SOLUTION. IN ANY EVENT...BETTER CHANCES OF PRECIPITATION WILL EXIST
ACROSS THE NORTH AND WEST IN THE COOLER/DEEPER SATURATED LAYER.
THERE AGAIN WILL BE A WIDE RANGE IN TEMPERATURES ACROSS THE
AREA...WITH PLACES IN THE WARM SECTOR OUT AHEAD OF THE LOW CLIMBING
INTO THE 70S TO NEAR 80...WHILE BACK TO THE WEST HIGHS WILL ONLY
MAKE IT INTO THE 50S. AS FAR AS SEVERE WEATHER...IT WILL PROBABLY
COME DOWN TO TIMING...AS THE INSTABILITY WANES PRETTY QUICKLY FROM
WEST TO EAST THROUGH THE DAY AS THE LOW MOVES EASTWARD...THOUGH IF
IT WERE TO OCCUR IT WOULD PROBABLY BE IN OUR FAR EAST DURING THE
AFTERNOON AT MAXIMUM HEATING.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 311 PM CDT WED MAY 7 2014
WAVE EXITS RAPIDLY TO THE NORTHEAST THURSDAY NIGHT MAINLY LEAVING
RESIDUAL CHANCES FOR RAINFALL. THE ATMOSPHERE STABILIZES QUICKLY...
AND THE BEST CHANCE FOR MEASURABLE RAIN WILL BE ALONG AND BEHIND
THE WIND SHIFT/COLD FRONT WHERE THE MOISTURE IS DEEPER IN THE
STABLE AIR. LOOKING FURTHER TO THE SOUTHEAST...NORTHWEST IA IS
MORE IN THE SHALLOW MOISTURE/DRY SLOT AREA SO NOT REAL KEEN ON
PRECIP CHANCES IN THAT LOCATION AT THIS TIME. FRIDAY WILL BE A
PLEASANT DAY...ALBEIT RATHER BREEZY EAST OF THE JAMES RIVER VALLEY.
BUT A WELL MIXED ATMOSPHERE SHOULD GIVE HIGHS WELL INTO THE 60S.
IF WE MIX A BIT HIGHER...WE MAY NEED TO TACK ON A COUPLE OF
DEGREES MORE TO THESE READINGS.
FRIDAY NIGHT IS HIGHLIGHTED BY A STRONG SURGE OF THETAE ADVECTION
WHICH IS BASICALLY HARMLESS AS THE ATMOSPHERE REMAINS MOISTURE
STARVED BELOW ABOUT 600MB. THERE MAY BE A FEW STORMS MOVING INTO
SOUTH CENTRAL SD BY LATE TONIGHT...BUT OTHER LOCATIONS WILL REMAIN
DRY WITH LOWS WELL INTO THE 40S. THE THETAE ADVECTION IS IN
ADVANCE OF THE NEXT SHORT WAVE PASSAGE ON SATURDAY. BOTH THE NAM
AND GFS SHOW THE CRUX OF THE WAVE MOVING THROUGH OUR SOUTHERN AND
EASTERN ZONES PER THE UPPER QG FORCING. LOW LEVEL MOISTURE DOES
APPEAR TO PICK UP AHEAD OF THE SURFACE WIND SHIFT...SO 50 POPS
WERE PLACED EAST OF I 29. ELEVATED INSTABILITY ALSO LOOKS RATHER
ABUNDANT AT THIS TIME...SO JUST OPTED TO GO PURE THUNDERSTORMS FOR
NOW FOR THE AFTERNOON HOURS GENERALLY ALONG AND EAST OF I 29. FOR
HIGHS...SATURDAY LOOKS LIKE ANOTHER BREEZY AND WELL MIXED DAY AND
WITH A WARM LOWER ATMOSPHERE...WE ARE LOOKING AT UPPER 60S IN
HURON TO MID 70S AT SIOUX CITY AND STORM LAKE.
IN THE EXTENDED...THERE IS STILL QUITE A BIT OF DISCREPANCY
BETWEEN THE VARIOUS DETERMINISTIC SOLUTIONS. THEREFORE BLENDED THE
SOLUTIONS. THE ECMWF CONTINUES TO BE THE SOLUTION WHICH IS THE
MOST BULLISH WITH REGARDS TO RAINFALL IN THE SUNDAY THROUGH MONDAY
NIGHT TIME FRAME. BUT ADMITTEDLY IT IS DIFFICULT TO TELL BECAUSE
EACH MODEL HAS BEEN VERY CONSISTENT WITH THEIR RESPECTIVE OUTPUTS.
MORE CERTAIN IS THAT TEMPERATURES WILL BE WELL BELOW NORMAL
THROUGH THE MIDDLE OF NEXT WEEK WITH BREEZY CONDITIONS LIKELY
EARLY IN THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1211 PM CDT WED MAY 7 2014
LOW CONFIDENCE IS CONVECTIVE CHANCES THROUGH THE TAF PERIOD WITH
MODEL DIFFERENCES...THOUGH MAY SEE SCATTERED THUNDERSTORMS
DEVELOP IN SOUTHWESTERN MINNESOTA LATE THIS AFTERNOON...THEN
THROUGH CENTRAL SOUTH DAKOTA TONIGHT INTO TOMORROW MORNING.
FARTHER TO THE SOUTH AND EAST...DRY SLOT MAY RULE AND DID NOT
INCLUDE CONVECTION AT KFSD AND KSUX...THOUGH CANNOT RULE IT OUT.
DOES LOOK LIKE CEILINGS WILL LOWER LATER TONIGHT INTO THE
MVFR/UPPER IFR RANGE OVER PORTIONS OF THE AREA.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...MJ
AVIATION...JM
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
104 PM CDT WED MAY 7 2014
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
MADE A FEW CHANGES TO THE FORECAST THIS MORNING...MAINLY TO
DECREASE POP THROUGH THIS AFTERNOON. AN UPPER LEVEL SHORT WAVE
JUST OFF TO THE WEST OF ABERDEEN WILL CONTINUE TO PUSH
NORTHEASTWARD INTO NORTH DAKOTA. THIS SYSTEM IS PRODUCING LIGHT
SHOWERS ACROSS NORTH CENTRAL SOUTH DAKOTA. BETTER LLM AND SHEAR
FURTHER EAST IS RESULTING IN MARGINALLY STRONG STORMS WITH RADAR
SHOWING SOME SMALL HAIL POSSIBLE. THESE STORMS SHOULD CONTINUE
PUSHING INTO SE NORTH DAKOTA WITHIN THE NEXT FEW HOURS. THERE IS A
GOOD POSSIBILITY FOR DRY CONDITIONS THROUGH THIS AFTERNOON BEFORE
THE NEXT UPPER LEVEL SHORT WAVE MOVES INTO THE REGION FROM THE
SOUTHWEST.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...THROUGH FRIDAY
WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY CONTINUES BOTH SOUTH
AND WEST OF THE CWA THANKS TO SOUTHWEST FLOW ALOFT WITH WEAK
EMBEDDED WAVES. THE 06Z HRRR BRINGS CONVECTIVE REMNANTS INTO THE
WESTERN CWA THROUGH THE MORNING HOURS...BUT HAVE ALREADY SEEN
SIMILAR ATTEMPTS BY SHOWERS TO CROSS INTO THE FORECAST AREA...ONLY
TO WASH OUT...SO FORECASTER CONFIDENCE CONTINUES TO REMAIN LOW
EVEN IN THE NEAR TERM.
MODELS DO HAVE A BETTER DEFINED WAVE MOVING UP FROM THE SOUTH
TODAY. BEST ISENTROPIC FORCING WILL SET UP JUST NORTH OF A KMBG
TO KPHP LINE. INSTABILITY PEAKS JUST SOUTH OF A WARM FRONT FOR THE
EASTERN CWA THIS AFTERNOON AS WELL. LOOKING AT NAM/RAP
PROFILES...SURFACE BASED CONVECTION APPEARS UNLIKELY AS THE FRONT
IS SOUTH OF THE CWA...AND GUIDANCE HAS A DIFFICULT TIME WARMING
ENOUGH TO OVERCOME THE INVERSION. STEEP LAPSE RATES ABOVE THE
INVERSION WITH STRONG SOUTHWEST MID LEVEL FLOW WILL SUPPORT A HAIL
THREAT IF ANY STORMS DO DEVELOP.
OVERNIGHT...A COUPLED JET STRUCTURE WILL SUPPORT AN AREA OF RAIN
THAT WILL LIFT OUT OF THE NEBRASKA PANHANDLE THROUGH
WESTERN/CENTRAL SOUTH DAKOTA. MOST OF THE GUIDANCE TAKES THIS
FEATURE NORTHEAST BETWEEN KPIR AND KMBG...THOUGH SREF GUIDANCE IS
A TAD FARTHER WEST. SREF PROBABILITIES SUGGEST FAIRLY HIGH QPF
POTENTIAL WITH THIS FEATURE...WHICH IS SUPPORTED WITHIN MOST
GUIDANCE. THE GFS IS PEGGED AT NEARLY 30 MICROBARS OF LIFT BY 12Z
THURSDAY. TROWAL WRAP AROUND LIGHT RAIN WILL CONTINUE THROUGH THE
DAY...BUT WE WILL SEE ISENTROPIC DOWNGLIDE BY LATE
AFTERNOON/EVENING HELPING TO DRY US OUT FOR FRIDAY.
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY
THE EXTENDED PERIOD CONTINUES THE ACTIVE PATTERN WITH A COUPLE OF
SYSTEMS MOVING THROUGH. THE FIRST WEAKER WAVE MOVES OFF THE
ROCKIES FRIDAY NIGHT AND INTO EASTERN SD SATURDAY BRINGING SOME
SHOWERS AND TSTORMS.
THERE WILL LIKELY BE A BRIEF BREAK IN PRECIP SAT MORNING BEFORE A
MORE WELL DEVELOPED SFC LOW ENTERS THE CENTRAL PLAINS SAT NIGHT.
AT THE SAME TIME AN UPPER LOW WILL DROP DOWN INTO ND. WHILE THE
MODELS AGREE ON THE SFC SYNOPTIC PATTERN...THERE IS SOME
DISCREPANCY AT JUST WHEN THE UPPER TROF WILL BEGIN TO AFFECT THE
NORTHERN PLAINS. THIS WILL INFLUENCE AREAL COVERAGE OF PRECIP
DURING ANY GIVEN PERIOD FROM SAT NIGHT THROUGH TUESDAY. THE ECMWF
KEEPS THE PRECIP ONLY OVER THE FAR SOUTHERN CWA WHILE THE GFS HAS
THE ENERGY FROM THE UPPER LOW DIGGING A LITTLE FARTHER SOUTH ON
SUNDAY. KEPT ALLBLEND POPS FOR NOW OVER THE WEEKEND BUT A DRIER
SOLUTION IS POSSIBLE.
TEMPERATURES WILL TREND DOWN THROUGH THE PERIOD WITH THE COOLEST
TEMPS OCCURRING WHEN THE LONGWAVE TROUGH MOVES OVER THE PLAINS.
TEMPS WILL BE AROUND 10 DEGREES COOLER THAN AVERAGE BY THE LATTER
HALF OF THE EXTENDED.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
REGIONAL SATL AND RADAR ANALYSIS SHOWS LAST OF THE MORNING SHOWERS
AND TSTORMS EXITING THE AREA TO THE NORTH AND NORTHEAST AND SOME
BINOVC OR CLR SKIES DEVELOPING ACROSS CENTRAL AND NERN SD. VFR
CONDITIONS EXPECTED AT ALL TERMINALS INTO THE AFTN. KEPT VCTS FOR
LATER THIS AFTN AT ATY AS EAST CENTRAL SD STANDS THE BEST CHC TO
SEE TSTORMS DEVELOP. PUSHED RAIN CHANCES BACK FARTHER INTO THE
EVENING FOR ABR AS LATEST GUIDANCE SUGGESTS AREA OF PCPN MOVING
IN AFTER SUNSET AND LATE TONIGHT. HELD ONTO RAIN CHANCES FOR PIR
AND MBG EARLY THIS EVENING WITH BEST SHOT OF RAIN LATE AS WELL.
RAIN IS EXPECTED TO CONTINUE FOR ALL TAF SITES DURING THE MRNG HRS
THURSDAY WITH MVFR CIGS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...SD
SHORT TERM...CONNELLY
LONG TERM...WISE
AVIATION...VIPOND
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1058 AM CDT WED MAY 7 2014
.UPDATE...
MADE A FEW CHANGES TO THE FORECAST THIS MORNING...MAINLY TO
DECREASE POP THROUGH THIS AFTERNOON. AN UPPER LEVEL SHORT WAVE
JUST OFF TO THE WEST OF ABERDEEN WILL CONTINUE TO PUSH
NORTHEASTWARD INTO NORTH DAKOTA. THIS SYSTEM IS PRODUCING LIGHT
SHOWERS ACROSS NORTH CENTRAL SOUTH DAKOTA. BETTER LLM AND SHEAR
FURTHER EAST IS RESULTING IN MARGINALLY STRONG STORMS WITH RADAR
SHOWING SOME SMALL HAIL POSSIBLE. THESE STORMS SHOULD CONTINUE
PUSHING INTO SE NORTH DAKOTA WITHIN THE NEXT FEW HOURS. THERE IS A
GOOD POSSIBILITY FOR DRY CONDITIONS THROUGH THIS AFTERNOON BEFORE
THE NEXT UPPER LEVEL SHORT WAVE MOVES INTO THE REGION FROM THE
SOUTHWEST.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...THROUGH FRIDAY
WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY CONTINUES BOTH SOUTH
AND WEST OF THE CWA THANKS TO SOUTHWEST FLOW ALOFT WITH WEAK
EMBEDDED WAVES. THE 06Z HRRR BRINGS CONVECTIVE REMNANTS INTO THE
WESTERN CWA THROUGH THE MORNING HOURS...BUT HAVE ALREADY SEEN
SIMILAR ATTEMPTS BY SHOWERS TO CROSS INTO THE FORECAST AREA...ONLY
TO WASH OUT...SO FORECASTER CONFIDENCE CONTINUES TO REMAIN LOW
EVEN IN THE NEAR TERM.
MODELS DO HAVE A BETTER DEFINED WAVE MOVING UP FROM THE SOUTH
TODAY. BEST ISENTROPIC FORCING WILL SET UP JUST NORTH OF A KMBG
TO KPHP LINE. INSTABILITY PEAKS JUST SOUTH OF A WARM FRONT FOR THE
EASTERN CWA THIS AFTERNOON AS WELL. LOOKING AT NAM/RAP
PROFILES...SURFACE BASED CONVECTION APPEARS UNLIKELY AS THE FRONT
IS SOUTH OF THE CWA...AND GUIDANCE HAS A DIFFICULT TIME WARMING
ENOUGH TO OVERCOME THE INVERSION. STEEP LAPSE RATES ABOVE THE
INVERSION WITH STRONG SOUTHWEST MID LEVEL FLOW WILL SUPPORT A HAIL
THREAT IF ANY STORMS DO DEVELOP.
OVERNIGHT...A COUPLED JET STRUCTURE WILL SUPPORT AN AREA OF RAIN
THAT WILL LIFT OUT OF THE NEBRASKA PANHANDLE THROUGH
WESTERN/CENTRAL SOUTH DAKOTA. MOST OF THE GUIDANCE TAKES THIS
FEATURE NORTHEAST BETWEEN KPIR AND KMBG...THOUGH SREF GUIDANCE IS
A TAD FARTHER WEST. SREF PROBABILITIES SUGGEST FAIRLY HIGH QPF
POTENTIAL WITH THIS FEATURE...WHICH IS SUPPORTED WITHIN MOST
GUIDANCE. THE GFS IS PEGGED AT NEARLY 30 MICROBARS OF LIFT BY 12Z
THURSDAY. TROWAL WRAP AROUND LIGHT RAIN WILL CONTINUE THROUGH THE
DAY...BUT WE WILL SEE ISENTROPIC DOWNGLIDE BY LATE
AFTERNOON/EVENING HELPING TO DRY US OUT FOR FRIDAY.
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY
THE EXTENDED PERIOD CONTINUES THE ACTIVE PATTERN WITH A COUPLE OF
SYSTEMS MOVING THROUGH. THE FIRST WEAKER WAVE MOVES OFF THE
ROCKIES FRIDAY NIGHT AND INTO EASTERN SD SATURDAY BRINGING SOME
SHOWERS AND TSTORMS.
THERE WILL LIKELY BE A BRIEF BREAK IN PRECIP SAT MORNING BEFORE A
MORE WELL DEVELOPED SFC LOW ENTERS THE CENTRAL PLAINS SAT NIGHT.
AT THE SAME TIME AN UPPER LOW WILL DROP DOWN INTO ND. WHILE THE
MODELS AGREE ON THE SFC SYNOPTIC PATTERN...THERE IS SOME
DISCREPANCY AT JUST WHEN THE UPPER TROF WILL BEGIN TO AFFECT THE
NORTHERN PLAINS. THIS WILL INFLUENCE AREAL COVERAGE OF PRECIP
DURING ANY GIVEN PERIOD FROM SAT NIGHT THROUGH TUESDAY. THE ECMWF
KEEPS THE PRECIP ONLY OVER THE FAR SOUTHERN CWA WHILE THE GFS HAS
THE ENERGY FROM THE UPPER LOW DIGGING A LITTLE FARTHER SOUTH ON
SUNDAY. KEPT ALLBLEND POPS FOR NOW OVER THE WEEKEND BUT A DRIER
SOLUTION IS POSSIBLE.
TEMPERATURES WILL TREND DOWN THROUGH THE PERIOD WITH THE COOLEST
TEMPS OCCURRING WHEN THE LONGWAVE TROUGH MOVES OVER THE PLAINS.
TEMPS WILL BE AROUND 10 DEGREES COOLER THAN AVERAGE BY THE LATTER
HALF OF THE EXTENDED.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED THROUGH EARLY AFTERNOON. SHOWERS AND
THUNDERSTORMS WILL SPREAD EASTWARD DURING THE LATE AFTERNOON AND
EVENING. THE MOST LIKELY LOCATION TO SEE THUNDERSTORM ACTIVITY
WILL BE ACROSS THE SOUTHERN AND FAR EASTERN CWA...POSSIBLY
AFFECTING KPIR AND KATY FROM 21Z. CIGS WILL FALL INTO THE MVFR
CATEGORY BY LATE AFTERNOON...THEN INTO THE IFR CATEGORY BEHIND THE
LOW OVERNIGHT. LOWER VSBYS WILL BE POSSIBLE WITH THE PRECIPITATION
AS WELL.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...SD
SHORT TERM...CONNELLY
LONG TERM...WISE
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
656 AM CDT WED MAY 7 2014
.UPDATE...
KNOCKED BACK EASTERN PROGRESSION OF POPS THIS MORNING AS
LITTLE IF ANYTHING IS MAKING IT EAST OF THE MISSOURI RIVER ON
RADAR. ALSO TOOK OUT MENTION OF THUNDER THIS MORNING. BEST
CHANCES FOR TSTORM DEVELOPMENT APPEAR TO BE 20Z INTO THIS EVENING.
SEE UPDATED AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...THROUGH FRIDAY
WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY CONTINUES BOTH SOUTH
AND WEST OF THE CWA THANKS TO SOUTHWEST FLOW ALOFT WITH WEAK
EMBEDDED WAVES. THE 06Z HRRR BRINGS CONVECTIVE REMNANTS INTO THE
WESTERN CWA THROUGH THE MORNING HOURS...BUT HAVE ALREADY SEEN
SIMILAR ATTEMPTS BY SHOWERS TO CROSS INTO THE FORECAST AREA...ONLY
TO WASH OUT...SO FORECASTER CONFIDENCE CONTINUES TO REMAIN LOW
EVEN IN THE NEAR TERM.
MODELS DO HAVE A BETTER DEFINED WAVE MOVING UP FROM THE SOUTH
TODAY. BEST ISENTROPIC FORCING WILL SET UP JUST NORTH OF A KMBG
TO KPHP LINE. INSTABILITY PEAKS JUST SOUTH OF A WARM FRONT FOR THE
EASTERN CWA THIS AFTERNOON AS WELL. LOOKING AT NAM/RAP
PROFILES...SURFACE BASED CONVECTION APPEARS UNLIKELY AS THE FRONT
IS SOUTH OF THE CWA...AND GUIDANCE HAS A DIFFICULT TIME WARMING
ENOUGH TO OVERCOME THE INVERSION. STEEP LAPSE RATES ABOVE THE
INVERSION WITH STRONG SOUTHWEST MID LEVEL FLOW WILL SUPPORT A HAIL
THREAT IF ANY STORMS DO DEVELOP.
OVERNIGHT...A COUPLED JET STRUCTURE WILL SUPPORT AN AREA OF RAIN
THAT WILL LIFT OUT OF THE NEBRASKA PANHANDLE THROUGH
WESTERN/CENTRAL SOUTH DAKOTA. MOST OF THE GUIDANCE TAKES THIS
FEATURE NORTHEAST BETWEEN KPIR AND KMBG...THOUGH SREF GUIDANCE IS
A TAD FARTHER WEST. SREF PROBABILITIES SUGGEST FAIRLY HIGH QPF
POTENTIAL WITH THIS FEATURE...WHICH IS SUPPORTED WITHIN MOST
GUIDANCE. THE GFS IS PEGGED AT NEARLY 30 MICROBARS OF LIFT BY 12Z
THURSDAY. TROWAL WRAP AROUND LIGHT RAIN WILL CONTINUE THROUGH THE
DAY...BUT WE WILL SEE ISENTROPIC DOWNGLIDE BY LATE
AFTERNOON/EVENING HELPING TO DRY US OUT FOR FRIDAY.
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY
THE EXTENDED PERIOD CONTINUES THE ACTIVE PATTERN WITH A COUPLE OF
SYSTEMS MOVING THROUGH. THE FIRST WEAKER WAVE MOVES OFF THE
ROCKIES FRIDAY NIGHT AND INTO EASTERN SD SATURDAY BRINGING SOME
SHOWERS AND TSTORMS.
THERE WILL LIKELY BE A BRIEF BREAK IN PRECIP SAT MORNING BEFORE A
MORE WELL DEVELOPED SFC LOW ENTERS THE CENTRAL PLAINS SAT NIGHT.
AT THE SAME TIME AN UPPER LOW WILL DROP DOWN INTO ND. WHILE THE
MODELS AGREE ON THE SFC SYNOPTIC PATTERN...THERE IS SOME
DISCREPANCY AT JUST WHEN THE UPPER TROF WILL BEGIN TO AFFECT THE
NORTHERN PLAINS. THIS WILL INFLUENCE AREAL COVERAGE OF PRECIP
DURING ANY GIVEN PERIOD FROM SAT NIGHT THROUGH TUESDAY. THE ECMWF
KEEPS THE PRECIP ONLY OVER THE FAR SOUTHERN CWA WHILE THE GFS HAS
THE ENERGY FROM THE UPPER LOW DIGGING A LITTLE FARTHER SOUTH ON
SUNDAY. KEPT ALLBLEND POPS FOR NOW OVER THE WEEKEND BUT A DRIER
SOLUTION IS POSSIBLE.
TEMPERATURES WILL TREND DOWN THROUGH THE PERIOD WITH THE COOLEST
TEMPS OCCURRING WHEN THE LONGWAVE TROUGH MOVES OVER THE PLAINS.
TEMPS WILL BE AROUND 10 DEGREES COOLER THAN AVERAGE BY THE LATTER
HALF OF THE EXTENDED.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED THROUGH EARLY AFTERNOON. SHOWERS AND
THUNDERSTORMS WILL SPREAD EASTWARD DURING THE LATE AFTERNOON AND
EVENING. THE MOST LIKELY LOCATION TO SEE THUNDERSTORM ACTIVITY
WILL BE ACROSS THE SOUTHERN AND FAR EASTERN CWA...POSSIBLY
AFFECTING KPIR AND KATY FROM 21Z. CIGS WILL FALL INTO THE MVFR
CATEGORY BY LATE AFTERNOON...THEN INTO THE IFR CATEGORY BEHIND THE
LOW OVERNIGHT. LOWER VSBYS WILL BE POSSIBLE WITH THE PRECIPITATION
AS WELL.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...CONNELLY
LONG TERM...WISE
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
342 AM CDT WED MAY 7 2014
.SHORT TERM...THROUGH FRIDAY
WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY CONTINUES BOTH SOUTH
AND WEST OF THE CWA THANKS TO SOUTHWEST FLOW ALOFT WITH WEAK
EMBEDDED WAVES. THE 06Z HRRR BRINGS CONVECTIVE REMNANTS INTO THE
WESTERN CWA THROUGH THE MORNING HOURS...BUT HAVE ALREADY SEEN
SIMILAR ATTEMPTS BY SHOWERS TO CROSS INTO THE FORECAST AREA...ONLY
TO WASH OUT...SO FORECASTER CONFIDENCE CONTINUES TO REMAIN LOW
EVEN IN THE NEAR TERM.
MODELS DO HAVE A BETTER DEFINED WAVE MOVING UP FROM THE SOUTH
TODAY. BEST ISENTROPIC FORCING WILL SET UP JUST NORTH OF A KMBG
TO KPHP LINE. INSTABILITY PEAKS JUST SOUTH OF A WARM FRONT FOR THE
EASTERN CWA THIS AFTERNOON AS WELL. LOOKING AT NAM/RAP
PROFILES...SURFACE BASED CONVECTION APPEARS UNLIKELY AS THE FRONT
IS SOUTH OF THE CWA...AND GUIDANCE HAS A DIFFICULT TIME WARMING
ENOUGH TO OVERCOME THE INVERSION. STEEP LAPSE RATES ABOVE THE
INVERSION WITH STRONG SOUTHWEST MID LEVEL FLOW WILL SUPPORT A HAIL
THREAT IF ANY STORMS DO DEVELOP.
OVERNIGHT...A COUPLED JET STRUCTURE WILL SUPPORT AN AREA OF RAIN
THAT WILL LIFT OUT OF THE NEBRASKA PANHANDLE THROUGH
WESTERN/CENTRAL SOUTH DAKOTA. MOST OF THE GUIDANCE TAKES THIS
FEATURE NORTHEAST BETWEEN KPIR AND KMBG...THOUGH SREF GUIDANCE IS
A TAD FARTHER WEST. SREF PROBABILITIES SUGGEST FAIRLY HIGH QPF
POTENTIAL WITH THIS FEATURE...WHICH IS SUPPORTED WITHIN MOST
GUIDANCE. THE GFS IS PEGGED AT NEARLY 30 MICROBARS OF LIFT BY 12Z
THURSDAY. TROWAL WRAP AROUND LIGHT RAIN WILL CONTINUE THROUGH THE
DAY...BUT WE WILL SEE ISENTROPIC DOWNGLIDE BY LATE
AFTERNOON/EVENING HELPING TO DRY US OUT FOR FRIDAY.
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY
THE EXTENDED PERIOD CONTINUES THE ACTIVE PATTERN WITH A COUPLE OF
SYSTEMS MOVING THROUGH. THE FIRST WEAKER WAVE MOVES OFF THE
ROCKIES FRIDAY NIGHT AND INTO EASTERN SD SATURDAY BRINGING SOME
SHOWERS AND TSTORMS.
THERE WILL LIKELY BE A BRIEF BREAK IN PRECIP SAT MORNING BEFORE A
MORE WELL DEVELOPED SFC LOW ENTERS THE CENTRAL PLAINS SAT NIGHT.
AT THE SAME TIME AN UPPER LOW WILL DROP DOWN INTO ND. WHILE THE
MODELS AGREE ON THE SFC SYNOPTIC PATTERN...THERE IS SOME
DISCREPANCY AT JUST WHEN THE UPPER TROF WILL BEGIN TO AFFECT THE
NORTHERN PLAINS. THIS WILL INFLUENCE AREAL COVERAGE OF PRECIP
DURING ANY GIVEN PERIOD FROM SAT NIGHT THROUGH TUESDAY. THE ECMWF
KEEPS THE PRECIP ONLY OVER THE FAR SOUTHERN CWA WHILE THE GFS HAS
THE ENERGY FROM THE UPPER LOW DIGGING A LITTLE FARTHER SOUTH ON
SUNDAY. KEPT ALLBLEND POPS FOR NOW OVER THE WEEKEND BUT A DRIER
SOLUTION IS POSSIBLE.
TEMPERATURES WILL TREND DOWN THROUGH THE PERIOD WITH THE COOLEST
TEMPS OCCURRING WHEN THE LONGWAVE TROUGH MOVES OVER THE PLAINS.
TEMPS WILL BE AROUND 10 DEGREES COOLER THAN AVERAGE BY THE LATTER
HALF OF THE EXTENDED.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL PREVAIL ACROSS THE AREA THROUGH THE OVERNIGHT
HOURS. SHOWER AND THUNDERSTORMS WILL OVERSPREAD THE WESTERN CWA
DURING THE LATE MORNING AND EARLY AFTERNOON HOURS...THEN WILL
SPREAD EASTWARD DURING THE LATE AFTERNOON AND EVENING. THE MOST
LIKELY LOCATION TO SEE THUNDERSTORMS ACTIVITY WILL BE ACROSS THE
SOUTHERN AND FAR EASTERN CWA...POSSIBLY AFFECTING KPIR AND KATY.
CIGS WILL FALL INTO THE MVFR CATEGORY BY MIDDAY...THEN INTO THE
VFR CATEGORY DURING THE LATE AFTERNOON HOURS. MVFR VSBYS WILL BE
POSSIBLE WITH THE PRECIPITATION AS WELL.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...CONNELLY
LONG TERM...WISE
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
323 PM CDT WED MAY 7 2014
.SHORT TERM (TONIGHT THROUGH ...COMPLEX AND DIFFICULT FORECAST
THROUGH THE SHORT TERM REGARDING POPS. WEAK UPPER LEVEL DISTURBANCE
AND SUBTROPICAL PLUME OF MOISTURE FROM THE PACIFIC HAS GENERATED
WEAK RETURNS ON THE RADAR TODAY ACROSS THE CWA. SPRINKLES AND
LIGHT RAIN HAVE REACHED THE GROUND IN ISOLATED LOCATIONS...BUT A
DRY 900-650MB LAYER HAS RESULTED IN MOSTLY VIRGA THUS FAR. MODELS
VARY WIDELY TONIGHT INTO THURSDAY MORNING WITH PRECIP PLACEMENT...
AND THE POORLY SAMPLED PACIFIC PLUME OF MOISTURE AND EMBEDDED
DISTURBANCES UPSTREAM ACROSS MEXICO ARE NOT HELPING. GENERALLY
MODELS DO SHOW THE AFOREMENTIONED DRY LAYER MOISTENING FROM WEST
TO EAST OVERNIGHT THROUGH MIDDAY THURSDAY...ALONG WITH 850MB
THETA-E RIDGE AXIS WEST OF THE RIO GRANDE MOVING EAST ON THURSDAY.
PWATS BY MIDDAY THURSDAY ARE AROUND 1.8-2 INCHES ACROSS THE CWA.
GFS AND HRRR INDICATING ELEVATED CONVECTION MOVING NORTHEAST OUT
OF MEXICO INTO THE WESTERN CWA LATER THIS EVENING AND OVERNIGHT...
ALONG WITH 4KM TEXAS TECH WRF. ECMWF EVEN MORE BULLISH WITH QPF
AMOUNTS AND FARTHER EAST INTO THE COASTAL BEND AND EASTERN BRUSH
COUNTRY. HOWEVER...NAM12 WELL NORTHWEST OF THE AREA WITH QPF AND
HI RES NMM/ARW KEYING IN ON AREAS SOUTH OF THE CWA. BASED ON
SATELLITE TRENDS UPSTREAM IN MEXICO HAVE SIDED TOWARDS LOW END
CHANCE POPS FOR NOW ACROSS THE WESTERN HALF OF THE CWA TONIGHT...
WITH THE FEELING THAT MID LEVEL DISTURBANCE IN THE SOUTHWEST FLOW
ALOFT AND MOISTENING OF THE DRY LAYER OUT WEST WILL ALLOW FOR
ELEVATED PRECIP TO REACH THE GROUND.
DURING THE DAY ON THURSDAY...AGAIN MODELS ARE GENERALLY CONSISTENT
WITH PLACEMENT OF MOISTURE AXIS MOVING WEST INTO CENTRAL AND
EVENTUALLY AREAS OF THE CWA. GOOD CHANCES FOR SURFACE BASED
CONVECTION TO DEVELOP THE BRUSH COUNTRY AND INLAND AREAS OF THE
COASTAL BEND DURING THE DAY ON THURSDAY...AS CAP ERODES AND MID
LEVEL DISTURBANCE CONTINUES EAST ACROSS THE CWA. BETTER JET
DYNAMICS MAY REMAIN JUST NORTH AND NORTHWEST OF THE CWA.
HOWEVER...THERE IS SUFFICIENT DEEP LAYER SHEAR IN PLACE AND IF ANY
SIGNIFICANT BREAKS IN CLOUD COVER OCCUR ACROSS THE CENTRAL AND
WESTERN CWA THERE COULD BE A FEW STRONGER STORMS. CONVECTION COULD
LINGER INTO THURSDAY NIGHT ACROSS THE COASTAL BEND AND VICTORIA
CROSSROADS. OVERALL THROUGH...CONFIDENCE IN THE ENTIRE SHORT TERM
FORECAST IS LOW GIVEN AFOREMENTIONED REASONS.
&&
.LONG-TERM (FRIDAY THROUGH WEDNESDAY)...NOT A WHOLE LOT OF MODEL
CONSENSUS IN THE EXTENDED PERIOD...AND DIFFICULT TO FIND A CLEAR
MODEL WINNER SO CONFIDENCE IN THIS PACKAGE IS SOMEWHAT LOWER THAN
TYPICAL. GENERAL IDEA IS FOR AN UPPER DISTURBANCE TO TRIGGER
SCATTERED PRECIPITATION FRIDAY...THEN TAPERING FRIDAY NIGHT AND
SATURDAY.
AFTER RIDGING BUILDS IN FOR SUNDAY...A STRONGER WAVE LOOKS
TO FORCE A COLD FRONT THROUGH THE REGION. GFS IS MORE THAN 12 HOURS
FASTER WITH THE FRONTAL PASSAGE THAN THE ECMWF. BASED ON PROJECTED
UPPER AIR PATTERN HAVE SLIGHTLY MORE FAITH IN THE ECMWF SOLUTION AT
THIS TIME. TEMPERATURES FROM MONDAY THROUGH WEDNESDAY WILL BE HIGHLY
DEPENDENT ON TIMING OF THE FRONT AND OF SURFACE HIGH PRESSURE THAT
BUILDS IN BEHIND THE FRONT. GFS AS USUAL IS VERY AGGRESSIVE WITH
COOL AIR BEHIND THE FRONT...SO FORECAST PACKAGE IS SOMEWHAT WARMER
AND CLOUDIER THAN WHAT NUMERICAL GUIDANCE WOULD SUGGEST. BY
WEDNESDAY SUBSIDENT HIGH PRESSURE IS WELL ESTABLISHED WITH DRIER
OFFSHORE FLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 75 86 73 87 73 / 20 50 30 40 30
VICTORIA 73 84 73 86 70 / 20 50 30 40 30
LAREDO 77 94 75 97 76 / 40 30 20 30 20
ALICE 74 89 73 90 72 / 30 50 30 40 30
ROCKPORT 74 80 73 86 73 / 20 30 30 40 30
COTULLA 74 92 72 93 71 / 40 50 20 30 20
KINGSVILLE 74 88 74 89 73 / 20 50 30 30 20
NAVY CORPUS 74 82 74 84 74 / 20 40 30 30 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
JR/76...SHORT TERM
JV/71...LONG TERM
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1133 PM CDT Tue May 6 2014
.UPDATE...
Increased overnight lows and introduced a slight chance of
thunderstorms along the I-10 corridor and northeast into the
Mason...Brady and San Saba.
&&
.DISCUSSION...
Extensive mid/upper clouds associated with the subtropical jet
and isolated thunderstorms in southwest Texas were moving
northeast across the region. Updated to increase lows into the
upper 60s to around 70. Also introduced a slight chance of
thunderstorms over areas south and east of the Concho Valley. The
main threat from storms will be strong gusty winds and deadly
lightning.
&&
.AVIATION...
/06Z TAFS/
MVFR stratus developing in the Hill Country was likely be delayed
by extensive mid/upper cloudiness over the region. However it
should eventually reach the I-10 corridor and areas around Brady around
9Z. Stratus deck may make it to San Angelo, though confidence is
not high, so kept it as a scattered layer. Isolated dry line
thunderstorm activity possible late Wednesday afternoon and
evening, but best chance of storms will be after 06Z/Thursday, so
left thunder out of this TAF issuance.
&&
.PREV DISCUSSION... /ISSUED 633 PM CDT TUE MAY 6 2014/
AVIATION...
/00Z TAFS/
Stratus with MVFR CIGS returns along the I-10 corridor around 9Z and
spreads northward. A few patches of stratus may affect KSJT, but
most should stay south. Winds will increase mid morning and further
increase late afternoon as lee trough strengthens. Isolated dry line
thunderstorm possible late Wednesday afternoon, but coverage too low
to put TAFS.
PREV DISCUSSION... /ISSUED 357 PM CDT TUE MAY 6 2014/
SHORT TERM...
(Tonight and Wednesday)
Expect hot and dry weather this afternoon and a chance of
thunderstorms Wednesday afternoon. A dryline was located along a
Fredrick, OK to Abilene to Sonora line at 20Z. Latest SPC
mesoanaylsis indicates weak instability(MLCAPES 500 to 1000 J/KG)
ahead of the dryline over the eastern part of our area. The
remaining convective inhibition or low level inversion may be
erased for isolated storms to develop mainly after 22Z across the
northern Heartland and eastern Big Country. the HRRR convective
allowing model has been showing isolated storms developing the
past several hourly runs. High LCLs and an inverted-v sounding
profiles favor strong gusty winds and hail with the stronger
storms. Also, storms will produce dangerous cloud to ground
lightning. Any storms that do develop will exit the area or
quickly dissipate by 02Z. The rest of tonight will see low level
southerly flow and low level moisture returning. The dryline will
retreat to just west of our area by 12Z Wednesday. Lows tonight
will be in the 60s to around 70.
For Wednesday, the morning looks quiet with low clouds across
much of the area. Low clouds will break up across much of the area
by early afternoon. Aloft, a strong upper level trough will be
located over the southern Rockies. A dryline will move slowly east
to along a Haskell to San Angelo line by late in the afternoon.
Low level convergence along the dryline and increasing large scale
ascent from approaching trough will cause isolated to scattered
thunderstorms to develop across much of West Central Texas mainly
after 20Z. The combination of some instability(MLCAPES of 1500 to
2000 J/KG) and 0-6KM bulk shear of 45 to 50 knots, will result in
some storms being severe. The main threats will be large hail,
damaging winds and dangerous cloud to ground lightning. Highs will
be 90 to 95.
LONG TERM...
(Wednesday night through next Tuesday)
By Wednesday night, the large upper level trough currently near
Las Vegas will be moving east through the desert southwest toward
west Texas. This feature will bring synoptic scale upward motion
with it into west and west central Texas from Wednesday evening
into Thursday.
Have generally bumped PoPs up again with this forecast, as we get
closer to the event, and become more confident in thunderstorms
taking place. In addition, have added the mention of severe
thunderstorms to the forecast for Wednesday evening, carrying over
the mention from the afternoon. With 0-6km bulk shear values of
40-55 knots, and SFC and mixed layer CAPE values ranging from near
1000 J/kg to as high as 1500 J/kg, there will be enough
instability, and storm organization carried over into the evening
hours for the threat of severe weather to be possible. As with the
previous period, the main concerns will be large hail and damaging
winds. As the event evolves overnight, the instability will wane,
and thus have the mention of severe weather in the forecast only
through 06Z. In addition to the severe weather possibility, some
of the thunderstorms will contain heavy rainfall, and localized
flooding will be possible, mainly in urban areas.
On Thursday, we will likely continue to see a broken line of
showers with embedded thunderstorms for the eastern half of the
area, especially during the morning hours as steering flow remain
southwest, making the exit of precipitation a little slow.
Severe weather concern will be limited with this mainly morning
activity.
One more weak shortwave will move through the area Friday
afternoon and evening, possibly providing one more shot at
precipitation for southeastern areas Friday afternoon and night.
Expect temperatures to continue to be above normal through the
forecast period. Thursday and Friday will be the cooler days
averaging mainly in the upper 80s to lower 90s. Temperatures will
quickly warm back into the mid 90s for the weekend.
Have not made any significant changes beyond the end of this week
as there is still a lot of uncertainty associated with the
forecast for early next week. The GFS is much more progressive and
weaker with an upper level system, sending a cold front into the
area Sunday night whereas the ECMWF is slower and stronger, and
waits until Monday evening to send a cold front into the area.
FIRE WEATHER...
Critical fire weather conditions are expected this afternoon and
early evening, generally west of a Haskell to Bronte line. A Red
Flag Warning is in effect until 9 PM across the western Big
Country and Northern Concho Valley due to RH values of 7 to 12
percent and southwest winds around 20 mph. Also, ERC values are at
record levels across this area. An increase in low level moisture
late tonight should result in RH values recovering to 60 to 80
percent across much of West Central Texas. Elevated fire weather
conditions are expected Wednesday afternoon west of a Haskell to
Ozona line due to RH values of 15 to 25 percent and wind speeds of
15 mph. Thunderstorms will bring potential wetting rains across
mainly northern and eastern areas Wednesday night and Thursday.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 69 94 67 87 61 / 5 30 50 30 10
San Angelo 71 94 68 91 57 / 5 20 40 20 10
Junction 71 91 70 87 66 / 10 20 50 40 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
04/24
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
359 PM EDT WED MAY 7 2014
.SYNOPSIS...
A WEAK FRONTAL BOUNDARY ACROSS SOUTHWEST VIRGINIA INTO WESTERN
NORTH CAROLINA TONIGHT WILL RETURN NORTHWARD THURSDAY AS HIGH
PRESSURE ALOFT BUILDS ACROSS THE REGION. VERY WARM CONDITIONS
THURSDAY AND FRIDAY UNDER THE UPPER RIDGE WILL GIVE WAY TO SHOWERS
AND THUNDERSTORMS OVER THE WEEKEND AS AN UPPER TROUGH APPROACHES
THE REGION FROM THE WEST.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 350 PM EDT WEDNESDAY...
REGIONAL WSR-88D IMAGES SHOWED DISSIPATING COMPLEX OF SHOWERS AND
THUNDERSTORMS NORTH OF OUR REGION MOVING EAST ACROSS NORTHERN VA TO
THE ATLANTIC COAST. SATELLITE PICTURE INDICATED HIGH CLOUDS PUSHING
SOUTH ACROSS THE REGION WITH CU FIELDS MAINLY ACROSS THE MOUNTAINS.
FRONTAL BOUNDARY REMAINS ACROSS OUR REGION THIS AFTERNOON INTO
TONIGHT. CAP IS STILL HOLDING DESPITE THE SOLAR HEATING...BUT IT IS
WEAKENING. HRRR GENERATE A FEW SHOWERS ACROSS THE SOUTHWEST HIGH
TERRAIN BUT KEPT MOST OF THE STORMS NORTH OF OUR AREA. THE NAM AND
GFS GENERATE SOME STORMS ACROSS THE NORTH THIS AFTERNOON INTO THIS
EVENING. THUS..ALLOWED FOR JUST A FEW SHOWERS THIS EVENING IN THE
HIGHER TERRAIN. UPPER RIDGE IS BUILDING INTO THE REGION FROM THE
WEST...AND BAROCLINIC ZONE NORTHWARD TONIGHT. WITH LOW LEVEL
MOISTURE AND LIGHT WINDS ELECTED TO ADD THE MENTION OF FOG
OVERNIGHT. WENT WITH LOW TEMPERATURES CLOSE TO THE ADJMAVBC WITH
READINGS FROM THE LOWER 50S IN THE NORTH TO THE LOWER 60S ACROSS THE
RIDGES.
THURSDAY WILL BE A VERY WARM DAY AS AN UPPER LEVEL RIDGE PASSES
ACROSS THE APPALACHIAN CHAIN. THE COMBINATION OF VERY WARM AIR
BUILDING IN FROM THE SOUTHWEST...COMBINED WITH ABUNDANT SUNSHINE AND
DOWNSLOPE WIND FLOW WILL ALLOW AFTERNOON TEMPERATURES TO TOP IN THE
LOWER 90S IN THE PIEDMONT...WHILE THE MOUNTAINS CAN EXPECT MID 80S
TO UPPER 70S...WITH COOLER TEMPERATURES AT HIGHER ELEVATIONS. A
STRONG LAYER OF STABLE AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL
HINDER SHOWERS AND THUNDERSTORMS DEVELOPMENT. HIGH TEMPERATURE
RECORDS IN THE MOUNTAINS ARE IN JEOPARDY THURSDAY REFER TO CLIMATE
SECTION.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 330 PM EDT WEDNESDAY...
RIDGE OVERHEAD THU NIGHT WILL GET PUSHED EAST BY TROUGH DIGGING
ACROSS THE MIDDLE OF THE COUNTRY WITH ASSOCIATED SHORTWAVES PUSHING
INTO THE OHIO VALLEY FRIDAY. FRONTAL BOUNDARY WORKING TOWARD THE
OHIO VALLEY FRIDAY WILL BE BRINGING INCREASED MOISTURE INTO THE
MOUNTAINS. THINK ENOUGH CONVERGENCE AND UPPER SUPPORT FOR SHOWERS
AND THUNDERSTORMS TO BE ISOLATED TO SCATTERED. ANOTHER WARM DAY WITH
HIGHS IN THE 80S.
FRI NIGHT-SAT...FRONT SLOWS DOWN AS IT BECOMES MORE PARALLEL TO
UPPER FLOW WHICH BECOMES MORE ZONAL. SHOWERS AND STORMS EDGE CLOSER
AND BY SATURDAY MORNING THE WRN CWA SHOULD SEE A GOOD THREAT FOR
SHOWERS. DO NOT EXPECT TO SEE A SVR THREAT GIVEN TIMING AND BEST
UPPER SUPPORT STAYS NORTH OVER THE GREAT LAKES.
SATURDAY WILL BE COOLER WITH CLOUD COVER AND SCATTERED
SHOWERS/ISOLATED STORMS WITH 70S WEST TO AROUND 80 EAST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 PM EDT WEDNESDAY...
OPERATIONAL RUNS OF THE GFS/ECMWF CONTINUE TO DIFFER ON THE PATTERN
NEXT WEEK...WITH THE ECWMF ENSEMBLES OVERALL PRETTY CONSISTENT. THE
UPPER PATTERN GOES FROM A SOUTHEAST RIDGE TO SOUTHWEST FLOW ALOFT
WITH 5H TROUGH DIGGING THRU THE CENTRAL PART OF THE COUNTRY MONDAY
AND BECOMING NEGATIVELY TILTED BY MIDWEEK. MAIN FRONT TO MOVE ACROSS
OUR REGION WEDNESDAY.
FOR THIS FORECAST ENOUGH CONVERGENCE WITH LEE TROUGH...UPPER
DIVERGENCE WITH SHORTWAVE OVER THE GULF COAST TO KEEP CHANCE POPS IN
SUNDAY. WILL SEE DIURNAL TYPE CYCLE FOR POPS INTO MONDAY WITH SFC
HIGH SITUATED OFF THE SE COAST WITH WARM/STATIONARY FRONTAL BOUNDARY
LINGERING OVER NOVA/NORTHERN WV. HUMIDITY EXPECTED TO BE ELEVATED AS
WELL.
AS WE HEAD TOWARD TUE-WED FRONTAL BOUNDARY AND UPPER LEVEL FORCING
WILL CLOSE IN WITH BETTER THREAT OF SHOWERS AND STORMS.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
AS OF 135 PM EDT WEDNESDAY...
MVFR SCT TO BKN CLOUDS EXPECTED THIS AFTERNOON INTO TONIGHT.
MORNING LOW CLOUDS ERODING ACROSS NORTH CAROLINA. CU FIELDS
DEVELOPING ACROSS THE MOUNTAINS THIS AFTERNOON. AN ISOLATED
SHOWER OR THUNDERSTORM IS POSSIBLE ESPECIALLY ACROSS THE HIGHEST
TERRAIN ALONG THE SOUTHERN BLUE RIDGE THIS AFTERNOON INTO TONIGHT.
HIGH CLOUDS WILL PUSH SOUTH ACROSS NORTHEAST PORTION OF CWA FROM
THUNDERSTORMS TO OUR NORTH THIS AFTERNOON INTO THIS EVENING.
AS WEDGE CONTINUES TO ERODE OVERNIGHT...EXPECT RETURN TO VFR
CONDITIONS ALL AREAS...ALTHOUGH SOME MVFR BR MAY DEVELOP LATE
NIGHT/EARLY THU MORNING AT LWB/LYH/BCB.
THIS AFTERNOON WINDS SHOULD GENERALLY BE ESE-SE MOST SITES AT
SPEEDS OF 5-8KTS...BECOMING CALM/VRB03KT AROUND 00Z THU...THEN SW
AFTER 12Z THU.
ON THURSDAY...THE FRONT LIFTS TO THE NORTH WITH WARMER AIR ALOFT
PUTTING A CAP ON ANY CONVECTION UNDER VFR CU FIELDS.
MEDIUM TO HIGH CONFIDENCE IN CEILINGS AND VISIBILITIES. HIGH
CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD.
EXTENDED AVIATION DISCUSSION...
BY LATE FRIDAY A COLD FRONT WILL APPROACH FROM THE
WEST...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE
MOUNTAINS DURING THE EVENING. BETTER CHANCE FOR SUB-VFR AT TIMES
SAT AFTERNOON/EVENING WITH THE FRONT SLOWLY MOVING EAST AND DEEPER
MOISTURE IN PLACE. BOUNDARY MAY WASH OUT UPON CROSSING THE AREA BY
SUNDAY WITH MAINLY VFR CONDITIONS EXPECTED OUTSIDE OF OCNL MVFR IN
SCATTERED AFTERNOON/EVENING SHRA.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS IN THE MOUNTAINS ARE IN JEOPARDY
THURSDAY. MAY GET CLOSE IN THE EAST.
CURRENT RECORDS FOR MAY 8TH...
ROANOKE......94/1940
LYNCHBURG....94/1940
DANVILLE.....92/1986
BLACKSBURG...85/2000
BLUEFIELD....84/2004
LEWISBURG....82/2000
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KK/RAB
NEAR TERM...KK
SHORT TERM...WP
LONG TERM...WP
AVIATION...KK/RAB
CLIMATE...PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
142 PM EDT WED MAY 7 2014
.SYNOPSIS...
HIGH PRESSURE ALONG THE EAST COAST WILL KEEP A RELATIVELY
COOL AIRMASS ACROSS MUCH OF THE REGION TODAY. A WEAK FRONTAL
BOUNDARY ACROSS SOUTHWEST VIRGINIA INTO WESTERN NORTH CAROLINA
WILL RETURN NORTHWARD THURSDAY AS HIGH PRESSURE ALOFT BUILDS
ACROSS THE REGION. VERY WARM CONDITIONS THURSDAY AND FRIDAY UNDER
THE UPPER RIDGE WILL GIVE WAY TO SHOWERS AND THUNDERSTORMS OVER
THE WEEKEND AS AN UPPER TROUGH APPROACHES THE REGION FROM THE
WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM EDT WEDNESDAY...
REGIONAL WSR-88D LOOP SHOWED MAIN COMPLEX OF THUNDERSTORMS
NORTH OF OUR REGION ACROSS NORTHERN VA AND WESTERN MD. THIS IS
WHERE THE BEST INSTABILITY IS LOCATED NORTH OF FRONTAL BOUNDARY.
SATELLITE IMAGES SHOWED LOW CLOUDS ERODING ACROSS OUR CWA.
DECREASED CLOUD COVER FOR THIS AFTERNOON AND INCREASED
TEMPERATURES AND HIGH TEMPERATURES FOR THIS AFTERNOON. HAVE A GOOD
AFTERNOON.
AS OF 943 AM EDT WEDNESDAY...
SATELLITE LOOP SHOWED THAT LOW LEVEL CLOUDS MIXING OUT THIS
MORNING...WITH THE RICHES CLOUDS ACROSS SOUTHERN PORTIONS OF CWA.
ADJUSTED CLOUD COVER FOR THIS MORNING INTO THIS AFTERNOON WITH
LATEST TRENDS. LOOKS LIKE THE NAM AND GFS ARE OVERDONE WITH
CONVECTION THIS AFTERNOON FOR CWA. PREFER THE HRRR WITH STORMS
STAYING TO THE NORTH OF OUR AREA. MATCHES UP NICELY WITH SWODY1
GENERAL THUNDERSTORM OUTLOOK FOR TODAY. THIS SEEM REASONABLE WITH
UPPER RIDGE BUILDING INTO THE REGION FROM THE WEST...AND
BAROCLINIC ZONE NORTHWARD TODAY. CAPPED ALOFT WAS QUITE HEALTHY
ESPECIALLY ACROSS SOUTHERN PORTIONS OF CWA. WITH PATCHY
CLOUDINESS...AND COOL WEDGE WILL HOLD WITH FORECAST HIGH
TEMPERATURES FOR THIS AFTERNOON. MAY NEED TO RAISE HIGHS DEPENDING
ON CLOUD COVER LATE THIS MORNING INTO THIS AFTERNOON. ONLY MINOR
ADJUSTMENTS IN TEMPERATURES AND DEW POINTS IN ISC GRIDS. MORE
CHANGES LATER....
AS OF 420 AM EDT WEDNESDAY...
QUASI-STATIONARY FRONT OF THE PAST SEVERAL DAYS MOVED BACK WEST
AGAIN TUESDAY EVENING...AND EARLY THIS MORNING WAS LOCATED FROM
NEAR LWB-BLF-TNB. AS EXPECTED LOW CLOUDS ARE DEVELOPING EAST OF
THE FRONT...ESPECIALLY IN UPSLOPE AREAS ALONG THE BLUE RIDGE FROM
SIF-ROA-LYH. FAIRLY FAVORABLE WEDGE PATTERN WITH BUILDING RIDGE
ALOFT AND SFC HIGH PRESSURE ANCHORED FROM QUEBEC SOUTHEASTWARD TO
OFF THE DELMARVA PENINSULA. THUS...EXPECT MUCH OF THE CWA TO
REMAIN MOSTLY CLOUDY AND RELATIVELY COOL TODAY WITH EASTERLY
MARITIME FLOW. MOST AREAS WILL SEE HIGHS IN THE UPPER 60S TO LOWER
70S EAST OF THE ALLEGHANY FRONT...MID 70S ACROSS THE NC
COUNTIES...APPROACHING 80 IN FAR SW VA/SOUTHERN WV...WHICH WILL
EITHER REMAIN WEST OF THE WEDGE BOUNDARY OR MOVE BACK INTO THE
WARM SECTOR DURING THE AFTERNOON.
WITH RESPECT TO CONVECTION...THE CHANCE FOR SUCH IN OUR CWA IS
DECREASING. WITH UPPER RIDGE BUILDING INTO THE REGION FROM THE
WEST...BAROCLINIC ZONE WILL BE PUSHED NORTHWARD...AND TODAY SHOULD
RESIDE FROM NORTHERN WV INTO NORTHERN VA. WITH WARMING TEMPS ALOFT
AND A COOL STABLE LAYER AT THE SFC...EXPECT LITTLE IF ANY
CONVECTION. IN THE FAR SW WHERE IT WILL BE MORE
UNSTABLE IT WILL BE CAPPED ALOFT...SO NOTHING EXPECTED THERE
EITHER. HOWEVER...A FEW SHOWERS OR SPRINKLES CANNOT BE TOTALLY
RULED OUT...ESPECIALLY THROUGH MID-DAY...BETWEEN THE BLUE RIDGE
AND THE ALLEGHANY FRONT ALONG-NORTH OF I-64...SUCH AS WE HAVE SEEN
FROM TIME-TO-TIME OVERNIGHT. WITH ALL OF THESE FACTORS IN
MIND...HAVE OPTED NOT TO MENTION TSRA FOR THE NEAR TERM. MODEL
INSTABILITY IS GROSSLY OVER ESTIMATED AND MY THINKING IS
CONSISTENT WITH SPCS LACK OF EVEN A GENERAL THUNDER AREA FOR OUR
CWA TODAY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM EDT WEDNESDAY...
THURSDAY IS SHAPING UP TO BE DRY AND VERY WARM AS AN UPPER LEVEL
RIDGE PASSES ACROSS THE APPALACHIAN CHAIN. THE COMBINATION OF VERY
WARM AIR BUILDING IN FROM THE SOUTHWEST...COMBINED WITH ABUNDANT
SUNSHINE AND GENERAL DOWNSLOPE WIND FLOW WILL ALLOW AFTERNOON
TEMPERATURES TO TOP OUT JUST ABOVE 90 IN A FEW AREAS ACROSS THE
SOUTHSIDE...WHILE THE MOUNTAINS CAN EXPECT MID 80S TO UPPER
70S...WITH COOLER TEMPERATURES AT HIGHER ELEVATIONS. A STRONG LAYER
OF STABLE AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL KEEP SHOWERS
AND THUNDERSTORMS AT BAY. SOUTHWESTERLY FLOW WILL ALSO RESULT IN
WARM OVERNIGHT LOWS...WITH MID 50S TO LOW 60S EXPECTED AREAWIDE.
UPPER RIDGING WILL SHIFT EAST ON FRIDAY...RESULTING IN SLIGHTLY MORE
INSTABILITY...PARTICULARLY DURING LATE AFTERNOON AND EARLY EVENING.
CONTINUED SOUTHWESTERLY FLOW WILL RESULT IN ANOTHER WARM DAY.
HOWEVER...WITH INCREASING CLOUD COVER AHEAD OF ANOTHER APPROACHING
FRONT...EXPECT FRIDAY AFTERNOON HIGHS TO BE SLIGHTLY COOLER THAN
THOSE ON THURSDAY. STILL...WILL BE LOOKING AT 80S FOR A MAJORITY OF
THE FORECAST REGION. EXPECT A FEW SHOWERS AND THUNDERSTORMS TO
DEVELOP ACROSS THE MOUNTAINS WITH MAXIMUM DAYTIME HEATING.
INSTABILITY APPEARS TO BE LIMITED...AND WITH ONLY VERY WEAK UPPER
LEVEL DISTURBANCES EXPECTED...CONVECTION SHOULD REMAIN SPOTTY AND
DISORGANIZED.
LONG RANGE MODELS APPEAR IN BETTER AGREEMENT THIS MORNING THAT UPPER
LEVEL RIDGING ACROSS THE EAST WILL GIVE WAY TO A MORE ZONAL WEST TO
EAST FLOW ON SATURDAY MORNING. THE ZONAL FLOW WILL CAUSE THE
APPROACHING COLD FRONT TO LOSE ITS COLD AIR PUSH...FORCING IT TO
STALL WEST OF OUR AREA. MINOR UPPER LEVEL DISTURBANCES WILL PASS
ACROSS THE REGION THROUGH THE DAY...RESULTING IN ROUNDS OF SHOWER
AND SOME THUNDERSTORM ACTIVITY...WITH THE BRUNT OF THE RAINFALL
OCCURRING ACROSS THE MOUNTAINS. REGARDLESS...INSTABILITY APPEARS TO
BE MARGINAL...AND THE POTENTIAL FOR STRONG THUNDERSTORMS WILL BE
REMOTE. INCREASED CLOUD COVER AND SPOTTY RAINFALL WILL MAKE FOR
COOLER AFTERNOON TEMPERATURES...WITH HIGHS REACHING INTO THE 70S
MOST LOCATIONS...POSSIBLY TOUCHING 80 AROUND DANVILLE.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 PM EDT TUESDAY...
VARIABILITY IN THE MODELS LEADS TO A LOW CONFIDENCE FORECAST FOR
SUNDAY THROUGH TUESDAY. THE GFS FAVORS A MORE ZONAL FLOW ALOFT NEXT
WEEK VS. A MORE AMPLIFIED ECMWF SOLUTION.
FOR SUNDAY...THE GFS INDICATES A LOW AMPLITUDE RIDGE BUILDING IN
FROM THE WEST...WITH ANOTHER FRONT COMING THROUGH ABOUT TUESDAY
EVENING. THE ECMWF IS MORE AMPLIFIED WITH THE RIDGING...CAUSING THE
SURFACE FRONT TO GET CAUGHT UNDERNEATH THE RIDGE AND HOLD WEST OF
OUR AREA. THIS RESULTS IN A WETTER SOLUTION OVERALL FOR THE LONG
TERM PERIOD.
SINCE THE CURRENT PATTERN FAVORS A MORE AMPLIFIED SOLUTION WILL
ENTERTAIN A FORECAST CLOSER TO THE ECMWF. AS SUCH TRENDED THE
FORECAST CLOUDIER AND COOLER TO START THE WEEK...TEMPERATURES MONDAY
AND TUESDAY WILL BE CLOSER TO NORMAL ALONG WITH A CHANCE OF SHOWERS.
BY MID WEEK...FLOW ALOFT SHOULD BECOME SOUTHWEST WITH ANOTHER WARM
SURGE PRIOR TO ANY FRONTAL PASSAGE IN THE LATE TUESDAY...THURSDAY
TIME FRAME.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 135 PM EDT WEDNESDAY...
MVFR SCT TO BKN CLOUDS EXPECTED THIS AFTERNOON INTO TONIGHT.
MORNING LOW CLOUDS ERODING ACROSS NORTH CAROLINA. CU FIELDS
DEVELOPING ACROSS THE MOUNTAINS THIS AFTERNOON. AN ISOLATED
SHOWER OR THUNDERSTORM IS POSSIBLE ESPECIALLY ACROSS THE HIGHEST
TERRAIN ALONG THE SOUTHERN BLUE RIDGE THIS AFTERNOON INTO TONIGHT.
HIGH CLOUDS WILL PUSH SOUTH ACROSS NORTHEAST PORTION OF CWA FROM
THUNDERSTORMS TO OUR NORTH THIS AFTERNOON INTO THIS EVENING.
AS WEDGE CONTINUES TO ERODE OVERNIGHT...EXPECT RETURN TO VFR
CONDITIONS ALL AREAS...ALTHOUGH SOME MVFR BR MAY DEVELOP LATE
NIGHT/EARLY THU MORNING AT LWB/LYH/BCB.
THIS AFTERNOON WINDS SHOULD GENERALLY BE ESE-SE MOST SITES AT
SPEEDS OF 5-8KTS...BECOMING CALM/VRB03KT AROUND 00Z THU...THEN SW
AFTER 12Z THU.
ON THURSDAY...THE FRONT LIFTS TO THE NORTH WITH WARMER AIR ALOFT
PUTTING A CAP ON ANY CONVECTION UNDER VFR CU FIELDS.
MEDIUM TO HIGH CONFIDENCE IN CEILINGS AND VISIBILITIES. HIGH
CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD.
EXTENDED AVIATION DISCUSSION...
BY LATE FRIDAY A COLD FRONT WILL APPROACH FROM THE
WEST...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS TO THE
MOUNTAINS DURING THE EVENING. BETTER CHANCE FOR SUB-VFR AT TIMES
SAT AFTERNOON/EVENING WITH THE FRONT SLOWLY MOVING EAST AND DEEPER
MOISTURE IN PLACE. BOUNDARY MAY WASH OUT UPON CROSSING THE AREA BY
SUNDAY WITH MAINLY VFR CONDITIONS EXPECTED OUTSIDE OF OCNL MVFR IN
SCATTERED AFTERNOON/EVENING SHRA.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS IN THE MOUNTAINS ARE IN JEOPARDY
THURSDAY. MAY GET CLOSE IN THE EAST.
CURRENT RECORDS FOR MAY 8TH...
ROANOKE......94/1940
LYNCHBURG....94/1940
DANVILLE.....92/1986
BLACKSBURG...85/2000
BLUEFIELD....84/2004
LEWISBURG....82/2000
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB
NEAR TERM...KK/RAB
SHORT TERM...NF
LONG TERM...NF/PM
AVIATION...KK/RAB
CLIMATE...PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1132 AM EDT WED MAY 7 2014
.SYNOPSIS...
HIGH PRESSURE ALONG THE EAST COAST WILL KEEP A RELATIVELY
COOL AIRMASS ACROSS MUCH OF THE REGION TODAY. A WEAK FRONTAL
BOUNDARY ACROSS SOUTHWEST VIRGINIA INTO WESTERN NORTH CAROLINA
WILL RETURN NORTHWARD THURSDAY AS HIGH PRESSURE ALOFT BUILDS
ACROSS THE REGION. VERY WARM CONDITIONS THURSDAY AND FRIDAY UNDER
THE UPPER RIDGE WILL GIVE WAY TO SHOWERS AND THUNDERSTORMS OVER
THE WEEKEND AS AN UPPER TROUGH APPROACHES THE REGION FROM THE
WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 AM EDT WEDNESDAY...
REGIONAL WSR-88D LOOP SHOWED MAIN COMPLEX OF THUNDERSTORMS
NORTH OF OUR REGION ACROSS NORTHERN VA AND WESTERN MD. THIS IS
WHERE THE BEST INSTABILITY IS LOCATED NORTH OF FRONTAL BOUNDARY.
SATELLITE IMAGES SHOWED LOW CLOUDS ERODING ACROSS OUR CWA.
DECREASED CLOUD COVER FOR THIS AFTERNOON AND INCREASED
TEMPERATURES AND HIGH TEMPERATURES FOR THIS AFTERNOON. HAVE A GOOD
AFTERNOON.
AS OF 943 AM EDT WEDNESDAY...
SATELLITE LOOP SHOWED THAT LOW LEVEL CLOUDS MIXING OUT THIS
MORNING...WITH THE RICHES CLOUDS ACROSS SOUTHERN PORTIONS OF CWA.
ADJUSTED CLOUD COVER FOR THIS MORNING INTO THIS AFTERNOON WITH
LATEST TRENDS. LOOKS LIKE THE NAM AND GFS ARE OVERDONE WITH
CONVECTION THIS AFTERNOON FOR CWA. PREFER THE HRRR WITH STORMS
STAYING TO THE NORTH OF OUR AREA. MATCHES UP NICELY WITH SWODY1
GENERAL THUNDERSTORM OUTLOOK FOR TODAY. THIS SEEM REASONABLE WITH
UPPER RIDGE BUILDING INTO THE REGION FROM THE WEST...AND
BAROCLINIC ZONE NORTHWARD TODAY. CAPPED ALOFT WAS QUITE HEALTHY
ESPECIALLY ACROSS SOUTHERN PORTIONS OF CWA. WITH PATCHY
CLOUDINESS...AND COOL WEDGE WILL HOLD WITH FORECAST HIGH
TEMPERATURES FOR THIS AFTERNOON. MAY NEED TO RAISE HIGHS DEPENDING
ON CLOUD COVER LATE THIS MORNING INTO THIS AFTERNOON. ONLY MINOR
ADJUSTMENTS IN TEMPERATURES AND DEW POINTS IN ISC GRIDS. MORE
CHANGES LATER....
AS OF 420 AM EDT WEDNESDAY...
QUASI-STATIONARY FRONT OF THE PAST SEVERAL DAYS MOVED BACK WEST
AGAIN TUESDAY EVENING...AND EARLY THIS MORNING WAS LOCATED FROM
NEAR LWB-BLF-TNB. AS EXPECTED LOW CLOUDS ARE DEVELOPING EAST OF
THE FRONT...ESPECIALLY IN UPSLOPE AREAS ALONG THE BLUE RIDGE FROM
SIF-ROA-LYH. FAIRLY FAVORABLE WEDGE PATTERN WITH BUILDING RIDGE
ALOFT AND SFC HIGH PRESSURE ANCHORED FROM QUEBEC SOUTHEASTWARD TO
OFF THE DELMARVA PENINSULA. THUS...EXPECT MUCH OF THE CWA TO
REMAIN MOSTLY CLOUDY AND RELATIVELY COOL TODAY WITH EASTERLY
MARITIME FLOW. MOST AREAS WILL SEE HIGHS IN THE UPPER 60S TO LOWER
70S EAST OF THE ALLEGHANY FRONT...MID 70S ACROSS THE NC
COUNTIES...APPROACHING 80 IN FAR SW VA/SOUTHERN WV...WHICH WILL
EITHER REMAIN WEST OF THE WEDGE BOUNDARY OR MOVE BACK INTO THE
WARM SECTOR DURING THE AFTERNOON.
WITH RESPECT TO CONVECTION...THE CHANCE FOR SUCH IN OUR CWA IS
DECREASING. WITH UPPER RIDGE BUILDING INTO THE REGION FROM THE
WEST...BAROCLINIC ZONE WILL BE PUSHED NORTHWARD...AND TODAY SHOULD
RESIDE FROM NORTHERN WV INTO NORTHERN VA. WITH WARMING TEMPS ALOFT
AND A COOL STABLE LAYER AT THE SFC...EXPECT LITTLE IF ANY
CONVECTION. IN THE FAR SW WHERE IT WILL BE MORE
UNSTABLE IT WILL BE CAPPED ALOFT...SO NOTHING EXPECTED THERE
EITHER. HOWEVER...A FEW SHOWERS OR SPRINKLES CANNOT BE TOTALLY
RULED OUT...ESPECIALLY THROUGH MID-DAY...BETWEEN THE BLUE RIDGE
AND THE ALLEGHANY FRONT ALONG-NORTH OF I-64...SUCH AS WE HAVE SEEN
FROM TIME-TO-TIME OVERNIGHT. WITH ALL OF THESE FACTORS IN
MIND...HAVE OPTED NOT TO MENTION TSRA FOR THE NEAR TERM. MODEL
INSTABILITY IS GROSSLY OVER ESTIMATED AND MY THINKING IS
CONSISTENT WITH SPCS LACK OF EVEN A GENERAL THUNDER AREA FOR OUR
CWA TODAY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM EDT WEDNESDAY...
THURSDAY IS SHAPING UP TO BE DRY AND VERY WARM AS AN UPPER LEVEL
RIDGE PASSES ACROSS THE APPALACHIAN CHAIN. THE COMBINATION OF VERY
WARM AIR BUILDING IN FROM THE SOUTHWEST...COMBINED WITH ABUNDANT
SUNSHINE AND GENERAL DOWNSLOPE WIND FLOW WILL ALLOW AFTERNOON
TEMPERATURES TO TOP OUT JUST ABOVE 90 IN A FEW AREAS ACROSS THE
SOUTHSIDE...WHILE THE MOUNTAINS CAN EXPECT MID 80S TO UPPER
70S...WITH COOLER TEMPERATURES AT HIGHER ELEVATIONS. A STRONG LAYER
OF STABLE AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL KEEP SHOWERS
AND THUNDERSTORMS AT BAY. SOUTHWESTERLY FLOW WILL ALSO RESULT IN
WARM OVERNIGHT LOWS...WITH MID 50S TO LOW 60S EXPECTED AREAWIDE.
UPPER RIDGING WILL SHIFT EAST ON FRIDAY...RESULTING IN SLIGHTLY MORE
INSTABILITY...PARTICULARLY DURING LATE AFTERNOON AND EARLY EVENING.
CONTINUED SOUTHWESTERLY FLOW WILL RESULT IN ANOTHER WARM DAY.
HOWEVER...WITH INCREASING CLOUD COVER AHEAD OF ANOTHER APPROACHING
FRONT...EXPECT FRIDAY AFTERNOON HIGHS TO BE SLIGHTLY COOLER THAN
THOSE ON THURSDAY. STILL...WILL BE LOOKING AT 80S FOR A MAJORITY OF
THE FORECAST REGION. EXPECT A FEW SHOWERS AND THUNDERSTORMS TO
DEVELOP ACROSS THE MOUNTAINS WITH MAXIMUM DAYTIME HEATING.
INSTABILITY APPEARS TO BE LIMITED...AND WITH ONLY VERY WEAK UPPER
LEVEL DISTURBANCES EXPECTED...CONVECTION SHOULD REMAIN SPOTTY AND
DISORGANIZED.
LONG RANGE MODELS APPEAR IN BETTER AGREEMENT THIS MORNING THAT UPPER
LEVEL RIDGING ACROSS THE EAST WILL GIVE WAY TO A MORE ZONAL WEST TO
EAST FLOW ON SATURDAY MORNING. THE ZONAL FLOW WILL CAUSE THE
APPROACHING COLD FRONT TO LOSE ITS COLD AIR PUSH...FORCING IT TO
STALL WEST OF OUR AREA. MINOR UPPER LEVEL DISTURBANCES WILL PASS
ACROSS THE REGION THROUGH THE DAY...RESULTING IN ROUNDS OF SHOWER
AND SOME THUNDERSTORM ACTIVITY...WITH THE BRUNT OF THE RAINFALL
OCCURRING ACROSS THE MOUNTAINS. REGARDLESS...INSTABILITY APPEARS TO
BE MARGINAL...AND THE POTENTIAL FOR STRONG THUNDERSTORMS WILL BE
REMOTE. INCREASED CLOUD COVER AND SPOTTY RAINFALL WILL MAKE FOR
COOLER AFTERNOON TEMPERATURES...WITH HIGHS REACHING INTO THE 70S
MOST LOCATIONS...POSSIBLY TOUCHING 80 AROUND DANVILLE.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 PM EDT TUESDAY...
VARIABILITY IN THE MODELS LEADS TO A LOW CONFIDENCE FORECAST FOR
SUNDAY THROUGH TUESDAY. THE GFS FAVORS A MORE ZONAL FLOW ALOFT NEXT
WEEK VS. A MORE AMPLIFIED ECMWF SOLUTION.
FOR SUNDAY...THE GFS INDICATES A LOW AMPLITUDE RIDGE BUILDING IN
FROM THE WEST...WITH ANOTHER FRONT COMING THROUGH ABOUT TUESDAY
EVENING. THE ECMWF IS MORE AMPLIFIED WITH THE RIDGING...CAUSING THE
SURFACE FRONT TO GET CAUGHT UNDERNEATH THE RIDGE AND HOLD WEST OF
OUR AREA. THIS RESULTS IN A WETTER SOLUTION OVERALL FOR THE LONG
TERM PERIOD.
SINCE THE CURRENT PATTERN FAVORS A MORE AMPLIFIED SOLUTION WILL
ENTERTAIN A FORECAST CLOSER TO THE ECMWF. AS SUCH TRENDED THE
FORECAST CLOUDIER AND COOLER TO START THE WEEK...TEMPERATURES MONDAY
AND TUESDAY WILL BE CLOSER TO NORMAL ALONG WITH A CHANCE OF SHOWERS.
BY MID WEEK...FLOW ALOFT SHOULD BECOME SOUTHWEST WITH ANOTHER WARM
SURGE PRIOR TO ANY FRONTAL PASSAGE IN THE LATE TUESDAY...THURSDAY
TIME FRAME.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
AS OF 745 AM EDT WEDNESDAY...
LOW CLOUDS DEVELOPED AS EXPECTED...MAINLY EAST OF THE ALLEGHANY
FRONT. UNCERTAINTY REMAINS CONCERNING DURATION OF LOW CLOUDS AND
ASSOCIATED MVFR TO IFR CIGS AND MVFR VSBYS. BACK DOOR FRONT
SHIFTED BACK TO THE WEST AFTER SUNSET TUESDAY...AND NOW APPEARS
TO BE BACK INTO FAR SW VA NEAR MKJ. E-ENE WINDS EVIDENT ACROSS
MOST OF THE CWA. ALL MODELS POINT TOWARD THE COOLER...EASTERLY
MARITIME FLOW DOMINATING MUCH OF THE DAYTIME TODAY AS OPPOSED TO
YESTERDAY. THIS WILL OCCUR AS FAIRLY TYPICAL WEDGE SUPPORTING
PATTERN OF UPPER RIDGE BUILDING OVER SFC WEDGE/COLD AIR DAMMING.
CIGS IN LOW CLOUD AREAS GENERALLY IN THE 015-040 RANGE...SO A
VARIETY OF MVFR TO VFR. SOME IFR CIGS NOTED ACROSS NORTH CENTRAL
NC. LOWEST CIGS RIGHT ALONG UPSLOPE AREAS OF BLUE RIDGE...WITH
AREAS FURTHER EAST...E.G. LYH/DAN...SEEING MOSTLY VFR CIGS.
AMENDMENTS/ADJUSTMENTS WILL LIKELY CONTINUE THROUGH THE MORNING.
BY AFTERNOON...EXPECT GRADUAL IMPROVEMENT OF CIGS...WITH MOSTLY
VFR CONDITIONS WEST OF THE ALLEGHANY FRONT. MID-CLOUD DECK WILL
LIFT NORTH THROUGH THE DAY WITH THE WARM FRONT. VSBYS SHOULD
REMAIN MOSTLY VFR FROM THIS POINT THROUGH THE DAY. AS WEDGE
CONTINUES TO ERODE OVERNIGHT...EXPECT RETURN TO VFR CONDITIONS ALL
AREAS...ALTHOUGH SOME MVFR BR MAY DEVELOP LATE NIGHT/EARLY THU
MORNING AT LWB/LYH/BCB.
WINDS TODAY SHOULD GENERALLY BE ESE-SE MOST SITES AT SPEEDS OF
5-8KTS...BECOMING CALM/VRB03KT AROUND 00Z THU...THEN SW AFTER 12Z
THU.
LOW TO MEDIUM CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD.
MEDIUM CONFIDENCE IN VSBYS THROUGH 15Z...THEN HIGH CONFIDENCE IN
VFR VSBYS.
HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD.
EXTENDED AVIATION DISCUSSION...
THURSDAY...THE FRONT LIFTS TO THE NORTH WITH WARMER AIR ALOFT
PUTTING A CAP ON ANY CONVECTION UNDER VFR CU FIELDS. BY LATE
FRIDAY A COLD FRONT WILL APPROACH FROM THE WEST...BRINGING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS DURING THE
EVENING. BETTER CHANCE FOR SUB-VFR AT TIMES SAT AFTERNOON/EVENING
WITH THE FRONT SLOWLY MOVING EAST AND DEEPER MOISTURE IN PLACE.
BOUNDARY MAY WASH OUT UPON CROSSING THE AREA BY SUNDAY WITH MAINLY
VFR CONDITIONS EXPECTED OUTSIDE OF OCNL MVFR IN SCATTERED
AFTERNOON/EVENING SHRA.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS IN THE MOUNTAINS ARE IN JEOPARDY
THURSDAY. MAY GET CLOSE IN THE EAST.
CURRENT RECORDS FOR MAY 8TH...
ROANOKE......94/1940
LYNCHBURG....94/1940
DANVILLE.....92/1986
BLACKSBURG...85/2000
BLUEFIELD....84/2004
LEWISBURG....82/2000
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB/KK
NEAR TERM...KK/RAB
SHORT TERM...NF
LONG TERM...NF/PM
AVIATION...JH/RAB
CLIMATE...PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
944 AM EDT WED MAY 7 2014
.SYNOPSIS...
HIGH PRESSURE ALONG THE EAST COAST WILL KEEP A RELATIVELY
COOL...CLOUDY AIR MASS ACROSS MUCH OF THE REGION TODAY. A WEAK
FRONTAL BOUNDARY ACROSS SOUTHWEST VIRGINIA INTO WESTERN NORTH
CAROLINA WILL RETURN NORTHWARD THURSDAY AS HIGH PRESSURE ALOFT
BUILDS ACROSS THE REGION. VERY WARM CONDITIONS THURSDAY AND FRIDAY
UNDER THE UPPER RIDGE WILL GIVE WAY TO SHOWERS AND THUNDERSTORMS
OVER THE WEEKEND AS AN UPPER TROUGH APPROACHES THE REGION FROM THE
WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 943 AM EDT WEDNESDAY...
SATELLITE LOOP SHOWED THAT LOW LEVEL CLOUDS MIXING OUT THIS
MORNING...WITH THE RICHES CLOUDS ACROSS SOUTHERN PORTIONS OF CWA.
ADJUSTED CLOUD COVER FOR THIS MORNING INTO THIS AFTERNOON WITH
LATEST TRENDS. LOOKS LIKE THE NAM AND GFS ARE OVERDONE WITH
CONVECTION THIS AFTERNOON FOR CWA. PREFER THE HRRR WITH STORMS
STAYING TO THE NORTH OF OUR AREA. MATCHES UP NICELY WITH SWODY1
GENERAL THUNDERSTORM OUTLOOK FOR TODAY. THIS SEEM REASONABLE WITH
UPPER RIDGE BUILDING INTO THE REGION FROM THE WEST...AND
BAROCLINIC ZONE NORTHWARD TODAY. CAPPED ALOFT WAS QUITE HEALTHY
ESPECIALLY ACROSS SOUTHERN PORTIONS OF CWA. WITH PATCHY
CLOUDINESS...AND COOL WEDGE WILL HOLD WITH FORECAST HIGH
TEMPERATURES FOR THIS AFTERNOON. MAY NEED TO RAISE HIGHS DEPENDING
ON CLOUD COVER LATE THIS MORNING INTO THIS AFTERNOON. ONLY MINOR
ADJUSTMENTS IN TEMPERATURES AND DEW POINTS IN ISC GRIDS. MORE
CHANGES LATER....
AS OF 420 AM EDT WEDNESDAY...
QUASI-STATIONARY FRONT OF THE PAST SEVERAL DAYS MOVED BACK WEST
AGAIN TUESDAY EVENING...AND EARLY THIS MORNING WAS LOCATED FROM
NEAR LWB-BLF-TNB. AS EXPECTED LOW CLOUDS ARE DEVELOPING EAST OF
THE FRONT...ESPECIALLY IN UPSLOPE AREAS ALONG THE BLUE RIDGE FROM
SIF-ROA-LYH. FAIRLY FAVORABLE WEDGE PATTERN WITH BUILDING RIDGE
ALOFT AND SFC HIGH PRESSURE ANCHORED FROM QUEBEC SOUTHEASTWARD TO
OFF THE DELMARVA PENINSULA. THUS...EXPECT MUCH OF THE CWA TO
REMAIN MOSTLY CLOUDY AND RELATIVELY COOL TODAY WITH EASTERLY
MARITIME FLOW. MOST AREAS WILL SEE HIGHS IN THE UPPER 60S TO LOWER
70S EAST OF THE ALLEGHANY FRONT...MID 70S ACROSS THE NC
COUNTIES...APPROACHING 80 IN FAR SW VA/SOUTHERN WV...WHICH WILL
EITHER REMAIN WEST OF THE WEDGE BOUNDARY OR MOVE BACK INTO THE
WARM SECTOR DURING THE AFTERNOON.
WITH RESPECT TO CONVECTION...THE CHANCE FOR SUCH IN OUR CWA IS
DECREASING. WITH UPPER RIDGE BUILDING INTO THE REGION FROM THE
WEST...BAROCLINIC ZONE WILL BE PUSHED NORTHWARD...AND TODAY SHOULD
RESIDE FROM NORTHERN WV INTO NORTHERN VA. WITH WARMING TEMPS ALOFT
AND A COOL STABLE LAYER AT THE SFC...EXPECT LITTLE IF ANY
CONVECTION. IN THE FAR SW WHERE IT WILL BE MORE
UNSTABLE IT WILL BE CAPPED ALOFT...SO NOTHING EXPECTED THERE
EITHER. HOWEVER...A FEW SHOWERS OR SPRINKLES CANNOT BE TOTALLY
RULED OUT...ESPECIALLY THROUGH MID-DAY...BETWEEN THE BLUE RIDGE
AND THE ALLEGHANY FRONT ALONG-NORTH OF I-64...SUCH AS WE HAVE SEEN
FROM TIME-TO-TIME OVERNIGHT. WITH ALL OF THESE FACTORS IN
MIND...HAVE OPTED NOT TO MENTION TSRA FOR THE NEAR TERM. MODEL
INSTABILITY IS GROSSLY OVER ESTIMATED AND MY THINKING IS
CONSISTENT WITH SPCS LACK OF EVEN A GENERAL THUNDER AREA FOR OUR
CWA TODAY.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 330 AM EDT WEDNESDAY...
THURSDAY IS SHAPING UP TO BE DRY AND VERY WARM AS AN UPPER LEVEL
RIDGE PASSES ACROSS THE APPALACHIAN CHAIN. THE COMBINATION OF VERY
WARM AIR BUILDING IN FROM THE SOUTHWEST...COMBINED WITH ABUNDANT
SUNSHINE AND GENERAL DOWNSLOPE WIND FLOW WILL ALLOW AFTERNOON
TEMPERATURES TO TOP OUT JUST ABOVE 90 IN A FEW AREAS ACROSS THE
SOUTHSIDE...WHILE THE MOUNTAINS CAN EXPECT MID 80S TO UPPER
70S...WITH COOLER TEMPERATURES AT HIGHER ELEVATIONS. A STRONG LAYER
OF STABLE AIR IN THE MID LEVELS OF THE ATMOSPHERE WILL KEEP SHOWERS
AND THUNDERSTORMS AT BAY. SOUTHWESTERLY FLOW WILL ALSO RESULT IN
WARM OVERNIGHT LOWS...WITH MID 50S TO LOW 60S EXPECTED AREAWIDE.
UPPER RIDGING WILL SHIFT EAST ON FRIDAY...RESULTING IN SLIGHTLY MORE
INSTABILITY...PARTICULARLY DURING LATE AFTERNOON AND EARLY EVENING.
CONTINUED SOUTHWESTERLY FLOW WILL RESULT IN ANOTHER WARM DAY.
HOWEVER...WITH INCREASING CLOUD COVER AHEAD OF ANOTHER APPROACHING
FRONT...EXPECT FRIDAY AFTERNOON HIGHS TO BE SLIGHTLY COOLER THAN
THOSE ON THURSDAY. STILL...WILL BE LOOKING AT 80S FOR A MAJORITY OF
THE FORECAST REGION. EXPECT A FEW SHOWERS AND THUNDERSTORMS TO
DEVELOP ACROSS THE MOUNTAINS WITH MAXIMUM DAYTIME HEATING.
INSTABILITY APPEARS TO BE LIMITED...AND WITH ONLY VERY WEAK UPPER
LEVEL DISTURBANCES EXPECTED...CONVECTION SHOULD REMAIN SPOTTY AND
DISORGANIZED.
LONG RANGE MODELS APPEAR IN BETTER AGREEMENT THIS MORNING THAT UPPER
LEVEL RIDGING ACROSS THE EAST WILL GIVE WAY TO A MORE ZONAL WEST TO
EAST FLOW ON SATURDAY MORNING. THE ZONAL FLOW WILL CAUSE THE
APPROACHING COLD FRONT TO LOSE ITS COLD AIR PUSH...FORCING IT TO
STALL WEST OF OUR AREA. MINOR UPPER LEVEL DISTURBANCES WILL PASS
ACROSS THE REGION THROUGH THE DAY...RESULTING IN ROUNDS OF SHOWER
AND SOME THUNDERSTORM ACTIVITY...WITH THE BRUNT OF THE RAINFALL
OCCURRING ACROSS THE MOUNTAINS. REGARDLESS...INSTABILITY APPEARS TO
BE MARGINAL...AND THE POTENTIAL FOR STRONG THUNDERSTORMS WILL BE
REMOTE. INCREASED CLOUD COVER AND SPOTTY RAINFALL WILL MAKE FOR
COOLER AFTERNOON TEMPERATURES...WITH HIGHS REACHING INTO THE 70S
MOST LOCATIONS...POSSIBLY TOUCHING 80 AROUND DANVILLE.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 PM EDT TUESDAY...
VARIABILITY IN THE MODELS LEADS TO A LOW CONFIDENCE FORECAST FOR
SUNDAY THROUGH TUESDAY. THE GFS FAVORS A MORE ZONAL FLOW ALOFT NEXT
WEEK VS. A MORE AMPLIFIED ECMWF SOLUTION.
FOR SUNDAY...THE GFS INDICATES A LOW AMPLITUDE RIDGE BUILDING IN
FROM THE WEST...WITH ANOTHER FRONT COMING THROUGH ABOUT TUESDAY
EVENING. THE ECMWF IS MORE AMPLIFIED WITH THE RIDGING...CAUSING THE
SURFACE FRONT TO GET CAUGHT UNDERNEATH THE RIDGE AND HOLD WEST OF
OUR AREA. THIS RESULTS IN A WETTER SOLUTION OVERALL FOR THE LONG
TERM PERIOD.
SINCE THE CURRENT PATTERN FAVORS A MORE AMPLIFIED SOLUTION WILL
ENTERTAIN A FORECAST CLOSER TO THE ECMWF. AS SUCH TRENDED THE
FORECAST CLOUDIER AND COOLER TO START THE WEEK...TEMPERATURES MONDAY
AND TUESDAY WILL BE CLOSER TO NORMAL ALONG WITH A CHANCE OF SHOWERS.
BY MID WEEK...FLOW ALOFT SHOULD BECOME SOUTHWEST WITH ANOTHER WARM
SURGE PRIOR TO ANY FRONTAL PASSAGE IN THE LATE TUESDAY...THURSDAY
TIME FRAME.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AS OF 745 AM EDT WEDNESDAY...
LOW CLOUDS DEVELOPED AS EXPECTED...MAINLY EAST OF THE ALLEGHANY
FRONT. UNCERTAINTY REMAINS CONCERNING DURATION OF LOW CLOUDS AND
ASSOCIATED MVFR TO IFR CIGS AND MVFR VSBYS. BACK DOOR FRONT
SHIFTED BACK TO THE WEST AFTER SUNSET TUESDAY...AND NOW APPEARS
TO BE BACK INTO FAR SW VA NEAR MKJ. E-ENE WINDS EVIDENT ACROSS
MOST OF THE CWA. ALL MODELS POINT TOWARD THE COOLER...EASTERLY
MARITIME FLOW DOMINATING MUCH OF THE DAYTIME TODAY AS OPPOSED TO
YESTERDAY. THIS WILL OCCUR AS FAIRLY TYPICAL WEDGE SUPPORTING
PATTERN OF UPPER RIDGE BUILDING OVER SFC WEDGE/COLD AIR DAMMING.
CIGS IN LOW CLOUD AREAS GENERALLY IN THE 015-040 RANGE...SO A
VARIETY OF MVFR TO VFR. SOME IFR CIGS NOTED ACROSS NORTH CENTRAL
NC. LOWEST CIGS RIGHT ALONG UPSLOPE AREAS OF BLUE RIDGE...WITH
AREAS FURTHER EAST...E.G. LYH/DAN...SEEING MOSTLY VFR CIGS.
AMENDMENTS/ADJUSTMENTS WILL LIKELY CONTINUE THROUGH THE MORNING.
BY AFTERNOON...EXPECT GRADUAL IMPROVEMENT OF CIGS...WITH MOSTLY
VFR CONDITIONS WEST OF THE ALLEGHANY FRONT. MID-CLOUD DECK WILL
LIFT NORTH THROUGH THE DAY WITH THE WARM FRONT. VSBYS SHOULD
REMAIN MOSTLY VFR FROM THIS POINT THROUGH THE DAY. AS WEDGE
CONTINUES TO ERODE OVERNIGHT...EXPECT RETURN TO VFR CONDITIONS ALL
AREAS...ALTHOUGH SOME MVFR BR MAY DEVELOP LATE NIGHT/EARLY THU
MORNING AT LWB/LYH/BCB.
WINDS TODAY SHOULD GENERALLY BE ESE-SE MOST SITES AT SPEEDS OF
5-8KTS...BECOMING CALM/VRB03KT AROUND 00Z THU...THEN SW AFTER 12Z
THU.
LOW TO MEDIUM CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD.
MEDIUM CONFIDENCE IN VSBYS THROUGH 15Z...THEN HIGH CONFIDENCE IN
VFR VSBYS.
HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD.
EXTENDED AVIATION DISCUSSION...
THURSDAY...THE FRONT LIFTS TO THE NORTH WITH WARMER AIR ALOFT
PUTTING A CAP ON ANY CONVECTION UNDER VFR CU FIELDS. BY LATE
FRIDAY A COLD FRONT WILL APPROACH FROM THE WEST...BRINGING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS DURING THE
EVENING. BETTER CHANCE FOR SUB-VFR AT TIMES SAT AFTERNOON/EVENING
WITH THE FRONT SLOWLY MOVING EAST AND DEEPER MOISTURE IN PLACE.
BOUNDARY MAY WASH OUT UPON CROSSING THE AREA BY SUNDAY WITH MAINLY
VFR CONDITIONS EXPECTED OUTSIDE OF OCNL MVFR IN SCATTERED
AFTERNOON/EVENING SHRA.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS IN THE MOUNTAINS ARE IN JEOPARDY
THURSDAY. MAY GET CLOSE IN THE EAST.
CURRENT RECORDS FOR MAY 8TH...
ROANOKE......94/1940
LYNCHBURG....94/1940
DANVILLE.....92/1986
BLACKSBURG...85/2000
BLUEFIELD....84/2004
LEWISBURG....82/2000
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB
NEAR TERM...KK/RAB
SHORT TERM...NF
LONG TERM...NF/PM
AVIATION...JH/RAB
CLIMATE...PM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
210 AM EDT WED MAY 7 2014
.SYNOPSIS...
A FRONT WILL REMAIN STALLED ACROSS OUR REGION TONIGHT THROUGH
WEDNESDAY. AN UPPER RIDGE WILL BUILD OVER THE REGION THURSDAY...
RESULTING IN WARMER AND DRIER CONDITIONS. HIGH PRESSURE WILL GIVE
WAY TO A SLOW MOVING FRONTAL SYSTEM LATE FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 900 PM EDT TUESDAY...
EVENING RNK SOUNDING SHOWING QUITE A BIT OF LOW LEVEL INSTABILITY
WITH CAPES NEAR 2K BEING CAPPED ALOFT VIA A DECENT INVERSION JUST
ABOVE 7H. HOWEVER LOW LEVELS REMAIN DRY WITH BETTER SURFACE
COOLING ONGOING AS THE EASTERLY FLOW HAS NOW FLOPPED BACK TO AS
FAR WEST AS THE BLUE RIDGE. IN ADDITION...SUPPORT ALOFT LACKING
ATTM TO ERODE THE CAP ...WHILE THE SURFACE BOUNDARY REMAINS TO THE
SW WHERE THE AIR REMAINS ARID ON THE WEST SIDE OF THE FRONT OVER
THE NW NC RIDGES. THUS LITTLE TO TRIGGER CONVECTION THERE.
HOWEVER DEWPOINTS LOOK TO SLOWLY RECOVER NORTHWARD EAST OF THE
BLUE RIDGE OVERNIGHT WITH A WEAK IMPULSE SLIDING ACROSS LATE IN
THE NW FLOW ALOFT. MODELS REMAIN OVERDONE WITH CONVECTION BUT
APPEARS A WINDOW POSSIBLE DURING THE NEXT FEW HOURS INTO THE EARLY
MORNING HOURS OVER THE FAR NORTH TO SEE A FEW BANDS OF SHRA/TSRA
WITH THIS FAINT FEATURE. GIVEN CURRENT LACK OF COVERAGE BASICALLY
REMOVED POPS EARLY THIS EVENING...AND CUT BACK TO MOSTLY ISOLATED
TO CHANCE COVERAGE NORTH OF HIGHWAY 460 DURING THE OVERNIGHT.
OTRW EXPECT LOW CLOUDS TO FILL BACK IN ESPCLY EAST AS THE WEDGE
DEEPENS AGAIN WITH MAINLY CLEAR SKIES OVER THE WEST/SW. SOME
PATCHY FOG ALSO POSSIBLE OUT EAST AND IN THE VALLEYS BUT QUITE
SPOTTY. ADJUSTED LOWS DOWN SOME BLUE RIDGE EAST PER EASTERLY FLOW
AND BUMPED UP WEST GIVEN SLOW TO FALL READINGS AND MORE OF A LIGHT
WEST WIND THROUGH DAYBREAK.
UPDATE AS OF 630 PM EDT TUESDAY...
EARLY UPDATE TO REMOVE GOING POPS ACROSS THE REGION INTO THIS
EVENING GIVEN LOW LEVEL DRY AIR IN PLACE PER OBS/MSAS AND LACK OF
MUCH CONVERGENCE OR SHRA. STILL POTENTIAL FOR ISOLATED COVERAGE TO
BREAK THE CAP ALOFT SEEN OFF EARLIER SOUNDINGS BUT CURRENT CLOUD
FIELDS AND LATEST MODELS SUGGEST MAY BE LATER WHEN A WEAK IMPULSE
ALOFT RIDES IN FROM THE NW. OTRW STILL SEEING QUITE A SPREAD IN
TEMPS FROM THE WEDGING IN THE NE TO THE VERY WARM TEMPS OVER THE
SW WHERE THE AIR IS VERY DRY PER HUMIDITY LEVELS BELOW 20 PERCENT.
WILL LEAVE IN CURRENT CHANCE POPS AFTER SUNSET WHEN MAY SEE
MOISTURE POOL ALONG THE BLUE RIDGE OTRW RUNNING DRY OVER THE NEXT
COUPLE OF HOURS PER THE LATEST HRRR.
PREVIOUS DISCUSSION AS OF 330 PM EDT TUESDAY...
FRONTAL BOUNDARY REMAINS ACROSS REGION THROUGH TONIGHT. SHORTWAVE
COMES OVER UPPER RIDGE INTO THE FORECAST AREA LATE TONIGHT. DESPITE
SOLAR HEATING...STRONG CAP THIS AFTERNOON HINDERING CONVECTION
DEVELOPMENT. WEAK DPVA ASSOCIATED WITH SHORTWAVE MAY BE ABLE TO
OVERCOME THE HEALTHY CAP. LIKE YESTERDAY...SWODY1 ADDED THE MENTION
OF A SEE TEXT FOR ISOLATED SEVERE THUNDERSTORMS WITH A HAIL AND WIND
THREAT FOR VIRGINIA. MODIFIED FCST SOUNDINGS SUGGEST RELATIVELY COLD
AIR ALOFT AND GOOD LAPSE RATES FOR THIS AFTERNOON INTO TONIGHT. RNK
WRFARW DEVELOPS SOME CONVECTION THIS AFTERNOON ACROSS THE NORTH TO
NORTHEAST CORNER OF CWA AND DROP SOUTHEAST. HRRR SHOWED SOME
ISOLATED CONVECTION ACROSS THE NORTH THIS EVENING INTO TONIGHT. GFS
AND ECMWF STILL SHOWING SCATTERED CONVECTION ACROSS THE NORTH WITH
WAA TONIGHT. WILL KEEP ISOLATED TO SCATTERED CONVECTION IN FOR THIS
EVENING INTO TONIGHT ACROSS THE NORTH. BUT...HAVE CONCERNS THAT CAP
MAY HOLD AND LIMITED CONVECTION. PLAYED LOW TEMPERATURES CLOSE TO
ADJMAVBC WITH READINGS FROM LOWER 50S IN THE NORTHERN MOUNTAINS TO
THE UPPER 50S IN THE PIEDMONT. THE H8 WARN FRONT LIFTS NORTH ON
WEDNESDAY. BEST LIFT AND INSTABILITY IS ACROSS THE NORTH FOR
WEDNESDAY. GOOD LAPSE RATE AND ELEVATED INSTABILITY SUPPORT MENTION
OF SHOWERS AND ISOLATED ACROSS THE NORTH. FLOW BECOME SOUTHERLY IN
THE SOUTH ON WEDNESDAY AND CAP IS EVEN STRONGER...ELECTED TO KEEP
MENTION OF STORMS OUT OF SOUTHERN PORTIONS OF FA. HIGH TEMPERATURES
ON WEDNESDAY CHALLENGING FOR THE NORTHEASTERN THIRD OF THE CWA WITH
CLOUDS AND POTENTIAL CONVECTION. HIGH TEMPERATURES ON WEDNESDAY WILL
VARY FROM AROUND 70 IN THE NORTH TO THE LOWER TO MID 80S IN THE FAR
SOUTHWEST AND ALONG THE FOOTHILLS OF THE SOUTHERN BLUE RIDGE
MOUNTAINS.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
AS OF 330 PM EDT TUESDAY...
TEMPERATURES WELL ABOVE NORMAL TO FINISH OFF THE WORK WEEK.
HIGH AMPLITUDE UPPER LEVEL FLOW WILL SUBJECT FORECAST AREA TO A
SURGE OF VERY WARM AIR THURSDAY AND FRIDAY. AN UPPER LEVEL RIDGE OF
HIGH PRESSURE IS EXPECTED TO AMPLIFY INTO THE 582 TO 588 DM RANGE
OVER THE EASTERN CONUS...AXIS RUNNING NORTH-SOUTH FROM ONTARIO
CANADA TO FLORIDA. THE GREATEST AMPLITUDE IS EXPECTED THURSDAY...
THEN BREAKING DOWN FRIDAY AS A MID CONUS TROF MOVES EAST.
850 MB TEMPS THURSDAY ARE PROGGED NEAR 18 DEG C. THIS ALONE WILL
PROMOTE TEMPERATURES WELL INTO THE 80S. AN ADDED BOOST WILL OCCUR
FROM ADIABATIC WARMING...WESTERLY WINDS RESULTING IN COMPRESSIONAL
HEATING AS THE AIR PASSES OVER AND DOWN THE MTNS. THE NET EFFECT
WILL BE TEMPERATURES WHICH WILL TEST THE 90 DEGREE MARK ON THE
EAST SIDE OF THE MOUNTAINS THURSDAY...AND TO A LESSER DEGREE
FRIDAY AS THE WINDS BACK MORE TOWARD THE SOUTHWEST AHEAD OF THE
APPROACHING MID CONUS TROUGH.
STRONG SUBSIDENCE THURSDAY WILL SQUELCH ANY CHANCE OF SHOWER
ACTIVITY YIELDING A MOSTLY SUNNY DAY. AS THE SUBSIDENCE WEAKENS
FRIDAY...SHOULD SEE A BIT MORE CUMULUS...BUT THINK ANY THREAT OF
SHOWER OR STORM ACTIVITY WILL HOLD OFF UNTIL LATE UNLESS AN OUTFLOW
BOUNDARY MOVES EAST OF THE MAIN MID CONUS FRONT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 330 PM EDT TUESDAY...
VARIABILITY IN THE MODELS LEADS TO A LOW CONFIDENCE FORECAST...
ESPECIALLY NEXT WEEK. SATURDAY IS THE ONLY DAY WHERE THE MODELS
REMOTELY LOOK SIMILAR...THEN THEY DIVERGE RESULTING IN DIFFERING
SOLUTIONS FOR SUNDAY THROUGH TUESDAY. THE GFS IS PROGRESSIVE AND
AND FAVORS ZONAL FLOW ALOFT NEXT WEEK VS. THE MORE AMPLIFIED ECMWF.
FOR SATURDAY BOTH MODELS BRING SURGE OF MOISTURE INTO THE AREA AHEAD
OF APPROACHING SURFACE FRONT. THIS RESULTS IN LIKELIHOOD OF SHOWERS
AND POSSIBLE THUNDERSTORMS...ESP ACROSS THE MOUNTAINS. THE GFS THEN
PUSHES THE FRONT THROUGH THE AREA QUICKLY WITH ANOTHER FRONT COMING
THROUGH ABOUT TUESDAY. THE ECMWF SLOWS SATURDAYS FRONT WITH
TROUGHING LINGERING THROUGH THE WEEKEND...FOLLOWED BY HIGHER
AMPLITUDE RIDGING ALOFT EARLY NEXT WEEK WITH THE SURFACE FRONT
GETTING CAUGHT UNDERNEATH THE RIDGE. THIS RESULTS IN A WETTER
SOLUTION THIS WEEKEND FOLLOWED BY A DAY OR TWO OF EASTERLY LOW LEVEL
FLOW MONDAY AND TUESDAY UNTIL WE MIX OUT THE MIDDLE OF NEXT WEEK.
SINCE THE CURRENT PATTERN FAVORS A MORE AMPLIFIED SOLUTION WILL
ENTERTAIN A FORECAST CLOSER TO THE ECMWF. AS SUCH TRENDED THE
FORECAST CLOUDIER AND COOLER TO START THE WEEK...TEMPERATURES MONDAY
AND TUESDAY CLOSER TO NORMAL ALONG WITH A CHANCE OF SHOWERS. BY MID
WEEK...FLOW ALOFT SHOULD BECOME SOUTHWEST WITH ANOTHER WARM SURGE
PRIOR TO ANY FRONTAL PASSAGE IN THE WEDNESDAY...THURSDAY TIME FRAME.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 150 AM EDT WEDNESDAY...
CONSIDERABLE UNCERTAINTY AT THIS POINT REGARDING THE
DEVELOPMENT...TIMING...AND DURATION OF LOW CLOUDS AND ASSOCIATED
MVFR TO IFR CIGS AND MVFR VSBYS. BACK DOOR FRONT SHIFTED BACK TO
THE WEST AFTER SUNSET...AND NOW APPEARS TO BE BACK INTO FAR SW VA
NEAR MKJ. E-ENE WINDS EVIDENT ACROSS MOST OF THE CWA...OR CALM
BCB/LWB. ALL MODELS POINT TOWARD THE COOLER...EASTERLY MARITIME
FLOW DOMINATING MUCH OF THE DAYTIME TODAY AS OPPOSED TO YESTERDAY.
THIS WILL OCCUR AS FAIRLY TYPICAL WEDGE SUPPORTING PATTERN OF
UPPER RIDGE BUILDING OVER SFC WEDGE/COLD AIR DAMMING. AS OF
NOW...THERE IS LITTLE TO NO EVIDENCE OF LOW CLOUDS ACROSS THE
PIEDMONT OR COASTAL PLAIN...BUT WATCHING POTENTIAL DEVELOPMENT OF
LOW CLOUDS ALONG THE BLUE RIDGE IN 11-3.9UM SATELLITE...WITH
SCT036 JUST NOW APPEARING IN ROA MTR. OTHER PATCHES OF LOW CLOUDS
BEGINNING TO APPEAR NEAR LYH. AMENDMENTS/ADJUSTMENTS LIKELY AS LOW
CLOUD DEVELOPMENT BECOMES MORE APPARENT. MEANWHILE...EXTENSIVE MID
CLOUDS IN THE 080-090 RANGE WILL CONTINUE TO SPREAD ACROSS THE
REGION FROM NW-SE IN NW FLOW ALOFT THROUGH THE MORNING HOURS.
THEN...THIS BAND OF CLOUDS WILL BEGIN TO LIFT NORTHWARD TOWARD
MD/PA AS UPPER RIDGE AMPLIFIES. ONCE THE CLOUD COVER
DEVELOPS...MANY QUESTIONS ALSO ARISE AS TO THE DURATION OF
SUCH...WITH MOST MODEL GUIDANCE SUGGESTING IT WILL REMAIN IN PLACE
THROUGH LATE MORNING/EARLY AFTERNOON AT LEAST. THIS SEEMS TO BE A
GOOD COMPROMISE AT THIS POINT...AS SYNOPTIC PATTERN COULD SUPPORT
SUCH CLOUDS REMAINING IN PLACE MOST OF THE DAY EAST OF THE BLUE
RIDGE. SOME POTENTIAL FOR MVFR VSBYS IN BR LATE NIGHT/EARLY
MORNING HOURS...BUT OVERALL POTENTIAL FOR SUCH APPEARS LESS THAN
YESTERDAY WITH STRATUS LOOKING MORE LIKELY TODAY. THIS IS
SUPPORTED BY BUFKIT SOUNDINGS AS WELL.
WINDS TODAY SHOULD GENERALLY BE ESE-SE MOST SITES AT SPEEDS OF
5-8KTS...BECOMING CALM/VRB03KT AROUND 00Z THU.
LOW CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD.
MEDIUM CONFIDENCE IN VSBYS THROUGH 15Z...THEN HIGH CONFIDENCE IN
VFR VSBYS.
HIGH CONFIDENCE IN WIND DIR/SPD THROUGH THE TAF VALID PERIOD.
EXTENDED AVIATION DISCUSSION...
THURSDAY...THE FRONT LIFTS TO THE NORTH WITH WARMER AIR ALOFT
PUTTING A CAP ON ANY CONVECTION UNDER VFR CU FIELDS. BY LATE
FRIDAY A COLD FRONT WILL APPROACH FROM THE WEST...BRINGING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE MOUNTAINS DURING THE
EVENING. BETTER CHANCE FOR SUB-VFR AT TIMES SAT AFTERNOON/EVENING
WITH THE FRONT SLOWLY MOVING EAST AND DEEPER MOISTURE IN PLACE.
BOUNDARY MAY WASH OUT UPON CROSSING THE AREA BY SUNDAY WITH MAINLY
VFR CONDITIONS EXPECTED OUTSIDE OF OCNL MVFR IN SCATTERED
AFTERNOON/EVENING SHRA.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS IN THE MOUNTAINS ARE IN JEOPARDY
THURSDAY. MAY GET CLOSE IN THE EAST.
CURRENT RECORDS FOR MAY 8TH...
ROANOKE......94/1940
LYNCHBURG....94/1940
DANVILLE.....92/1986
BLACKSBURG...85/2000
BLUEFIELD....84/2004
LEWISBURG....82/2000
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KK
NEAR TERM...JH/KK
SHORT TERM...PM
LONG TERM...PM
AVIATION...JH/RAB
CLIMATE...PM
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
1037 PM CDT THU MAY 8 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
AND NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 1018 PM CDT THU MAY 8 2014
ASIDE FROM A FEW STRONG CELLS MOVG UP THE LAKESHORE...STORMS
HAVE BEEN FAIRLY TAME THIS EVG. THERE ARE STILL A FEW SMALL
CLUSTERS OF TSTMS OVER FAR EASTERN MN AND FAR NE IA...BUT NO
WATCHES OR WARNINGS ARE IN EFFECT FOR UPSTREAM COUNTIES. INSTAB
CONTINUES TO WANE...WITH MUCAPE ONLY 200-600 J/KG...BUT WITH
STRONG SHEAR...A WARM FRONT OVER CENTRAL WI...AN APPROACHING COLD
FRONT AND UPPER TROF...AND A STRONG JET OVERHEAD...CANNOT RULE OUT
AN ISOLD SVR TSTM OVERNIGHT. OVERALL THREAT APPEARS TO BE QUITE
LOW.
HAVE ADJUSTED POPS LOWER TO ACCOUNT FOR THE CURRENT LULL IN
PCPN OVER C/EC WI...AND GIVEN UPSTREAM COVERAGE...POPS MAY ALSO
BE TOO HIGH FOR THE OVERNIGHT PERIOD. MODELS STILL SUPPORT AN
INCREASE IN COVERAGE OVER EASTERN WI AFTER MIDNIGHT...SO DON`T
WANT TO LOWER POPS TOO MUCH RIGHT NOW.
UPDATE
ISSUED AT 711 PM CDT THU MAY 8 2014
CERTAINLY NOT GIVING UP ON THE SEVERE POTENTIAL...BUT CURRENT
INDICATIONS SUGGEST THAT A WIDESPREAD EVENT IS NOT LIKELY.
MSAS SFC ANALYSIS SHOWED THAT THE WARM FRONT WAS SITUATED FROM
WEST CENTRAL WI TO AROUND WISCONSIN RAPIDS...OSHKOSH AND
SHEBOYGAN. WIDESPREAD SHOWERS AND TSTMS WERE OCCURRING OVER
THE NW HALF OF WI...AND WERE COMPETING FOR THE MARGINAL
INSTABILITY (MUCAPE 400-800 J/KG) THAT WAS SITUATED ACROSS THE
AREA. TSTMS WERE ALSO BATTLING SOME LINGERING SURFACE-BASED
CONVECTIVE INHIBITION. SHEAR IS QUITE STRONG...WITH 0-6 KM
BULK SHEAR OF 40-50 KTS...AND 0-3 KM SRH OF 200-400...SO
WILL NEED TO MONITOR ANY CELLS THAT BECOME ISOLATED FROM THE
ONGOING CLUSTERS. HAVE SEEN SOME INTERESTING STORM MORPHOLOGY...
INCLUDING A RECENT CELL SPLIT OVER WC WI...AND RESULTING RIGHT-
MOVING SUPERCELL CURRENTLY MOVG THROUGH NW JACKSON COUNTY.
DESPITE A LARGE NUMBERS OF ONGOING STORMS OVER MN/IA AND WSTRN
WI...THERE ARE RELATIVELY FEW WARNINGS CURRENTLY IN EFFECT.
CURRENT INDICATIONS SUGGEST THAT A WIDESPREAD SVR EVENT IS NOT
LIKELY...BUT LOCAL SUPERCELLS OR SHORT LINE SEGMENTS MAY POSE AN
ISOLD SVR THREAT...LARGE HAIL AND DAMAGING WINDS...THROUGH THE
NIGHT.
&&
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 330 PM CDT THU MAY 8 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
CENTERED OVER EASTERN NEBRASKA AND A WARM FRONT SNAKING ITS WAY
FROM JUST SOUTH OF MINNEAPOLIS TO VOLK FIELD TO WEST BEND
WISCONSIN. OCCASIONAL LIGHT SHOWERS CONTINUE TO REDEVELOP OVER THE
WARM FRONT...WHICH HAVE BEEN MAINLY IMPACTING CENTRAL TO NORTHEAST
WISCONSIN. BUT WITH THE FORWARD MOTION OF FRONT AT A SNAILS
PACE...INSTABILITY HAS BEEN SLOW TO DEVELOP THIS AFTERNOON.
ADDITIONAL LIGHT SHOWERS ASSOCIATED WITH A WEAK SHORTWAVE ARE ALSO
MOVING NORTHEAST OVER SOUTHERN WISCONSIN AND WILL MOVE INTO THE
FOX VALLEY OVER THE NEXT HOUR OR TWO. THIS WAVE WAS PRODUCING
THUNDERSTORMS OVER IOWA EARLIER BUT THOSE HAVE SINCE WEAKENED. THE
MAIN SHOW HOWEVER...IS OCCURRING OVER MINNESOTA AND NORTHERN IOWA
WHERE STRONG TO SEVERE THUNDERSTORMS ARE OCCURRING ALONG AN UPPER
LEVEL FRONT. AS THIS FRONT MOVES EAST...CHANCES OF SEVERE WEATHER
ARE THE MAIN FORECAST CONCERN.
TONIGHT...LOW PRESSURE WILL BE TRAVELING FROM SOUTHWEST MINNESOTA
TO THE WESTERN TIP OF LAKE SUPERIOR. POTENTIAL WILL REMAIN FOR THE
WARM FRONT TO BOW NORTHWARD ACROSS CENTRAL AND NORTH-CENTRAL
WISCONSIN THIS EVENING DUE STRENGTHENING SOUTHERLY FLOW AHEAD OF THE
LOW. HOW FAR NORTH IS STILL QUESTIONABLE GIVEN THE SCATTERED SHOWER
ACTIVITY...CLOUD COVER...AND EASTERLY FLOW. SHORTWAVE OVER EASTERN
IOWA WILL BE LIFTING NE ACROSS THE FORECAST AREA LATE THIS AFTERNOON
INTO THE EVENING AT PEAK HEATING. THINKING SCT SHOWERS AND ISOLD
TSTORMS WILL CONTINUE TO BE GENERATED FROM THIS WAVE...THAT COULD
HELP TO KEEP THE WARM FRONT FARTHER SOUTH THAN MODELS DEPICT. IF ANY
STORMS DEVELOP...40-50KTS OF BULK SHEAR WILL SUPPORT A CHANCE OF
LARGE HAIL AND DAMAGING WINDS...TO A LESSER EXTENT.. THEN ATTENTION
WILL TURN TO SEVERE THUNDERSTORMS WHICH ARE EXPECTED TO DEVELOP
LATER THIS AFTERNOON OVER MINNESOTA AND IOWA. THE LATEST SHORT
RANGE GUIDANCE SHOWS THIS CONVECTION...IN THE FORM OF LINE
SEGMENTS...MOVING INTO CENTRAL AND NORTH-CENTRAL WISCONSIN BY
MID-EVENING. CONVERGENCE ALONG THE UPPER LEVEL TROUGH AND UPPER
CONVERGENCE WILL PROVIDE DECENT FORCING FOR STORMS TO SUSTAIN
THEMSELVES. RATHER DIFFICULT TO GET GAUGE ON INSTABILITY SINCE
PROGGED SOUNDINGS ARE EITHER CONTAMINATED WITH CONVECTION OR NOT
REPRESENTATIVE OF THE CURRENT ENVIRONMENT. BUT ELEVATED CAPES ARE
GENERALLY AROUND 1K J/KG AND THATS A DECENT PLACE TO START. STEEP
MID-LEVEL LAPSE RATES AROUND 7 C/KM AND BULK SHEARS IN THE 35-40 KT
RANGE WILL SUPPORT A LARGE HAIL AND DAMAGING WIND THREAT. CHANCES
OF SEVERE THUNDERSTORMS LOOK BETTER OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN AS INSTABILITY DIMINISHES TO THE EAST. THE STORMS SHOULD
EXIT LATE OVERNIGHT...BUT ADDITIONAL SPOTTY SHOWERS AND STORMS COULD
STILL POP UP ALONG THE TRAILING SURFACE COLD FRONT. TEMPS WILL BE
WARM TONIGHT AND RANGE MAINLY FROM THE MID 50S TO LOW 60S.
FRIDAY...THE SURFACE COLD FRONT WILL EXIT EASTERN WISCONSIN BY
MID-MORNING...AND COULD SEE A PERIOD OF CLEARING OCCUR RIGHT BEHIND
THE FRONT AND BENEATH THE DRY SLOT. THEN SHOULD SEE WRAP AROUND
MOISTURE PUSH EAST ACROSS CENTRAL AND NORTH-CENTRAL WISCONSIN
THROUGH THE REST OF THE DAY. PROGGED SOUNDINGS SHOW A STRONG
INVERSION AT ABOUT 750MB...SO TONED BACK THE CHANCE OF SHOWERS OVER
CENTRAL AND NORTH-CENTRAL WISCONSIN SOME. AIR BEHIND THE FRONT IS
NOT ALL THAT COLD...AND KEPT TEMPERATURES RANGING FROM THE LOW 60S
WEST TO NEAR 70 NORTHEAST.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 330 PM CDT THU MAY 8 2014
LARGE SCALE MEAN FLOW IS EXPECTED TO BRIEFLY DEAMPLIFY THIS
WEEKEND BEFORE RE-AMPLIFYING EARLY NEXT WEEK AS UPR RIDGING OCCURS
OVER THE WEST COAST AND AN EWD MOVING LONGWAVE TROF SHIFTS FROM
THE CNTRL CONUS TO E-CNTRL NORTH AMERICA. PCPN CHCS TO BE
ASSOCIATED FIRST WITH A WEAK IMPULSE EJECTED NE FROM THE MEAN UPR
TROF DURING THE LATTER PART OF THE WEEKEND AND THEN EARLY NEXT
WEEK WITIH THE APPROACH OF THE UPR TROF AND THE MAIN SFC CYCLONE/
CDFNT. TEMPS ARE FCST TO GO FROM SLIGHTLY ABOVE NORMAL EARLY...TO
BELOW NORMAL BY MID-WEEK AS THE MEAN FLOW TURNS NW.
ANY LINGERING LIGHT SHWRS OVER NRN WI SHOULD GRADUALLY COME TO AN
END FRI EVENING AS THE SHORTWAVE TROF CONTS TO TRACK NE INTO SRN
ONTARIO. OTHERWISE...THE MDLS INDICATE A WEAK SFC RDG/RISING UPR
HEIGHTS WORKING EAST TOWARD THE WRN GREAT LAKES DURING THE OVRNGT
HOURS. DECREASING CLOUDS WITH DIMINISHING WINDS COULD SEND TEMPS
DOWN INTO THE 35-40 DEG RANGE NORTH...LWR TO MID 40S SOUTH.
SFC RDG MOVES ACROSS NE WI SAT MORNING AND BE TO OUR EAST BY SAT
AFTERNOON. MEANWHILE TO OUR WEST...A PIECE OF SHORTWAVE ENERGY IS
PROGGED TO EJECT EWD FROM THE DEVELOPING WRN CONUS UPR TROF AND
ALREADY BY PUSHING INTO THE UPR MS VALLEY BY 00Z SUNDAY. CLOUDS
SHOULD ALREADY BEGIN TO INCREASE INTO CNTRL WI SAT AFTERNOON...
BUT WL KEEP PCPN OUT OF THE FCST FOR NOW. MAX TEMPS TO REMAIN A
LITTLE ABOVE NORMAL AS WINDS ATTEMPT TO BACK TO THE SOUTH ONCE
AGAIN AHEAD OF THE APPROACHING SHORTWAVE TROF.
THIS SHORTWAVE TROF TO THEN RACE ACROSS WI SAT NGT...THEREBY
BRINGING A CHC OF SHWRS TO THE ENTIRE FCST AREA. INSTABILITY LOOKS
MARGINAL RIGHT NOW AND MAY GENERATE AN ISOLATED TSTM OR TWO ACROSS
CNTRL/E-CNTRL WI. PLENTY OF CLOUDS/PCPN IN THE VCNTY WL HOLD MIN
TEMPS IN THE MID TO UPR 40S NORTH...UPR 40S TO LWR 50 SOUTH. THERE
MAY NOW BE A BRIEF BREAK IN THE PCPN CHCS SUNDAY MORNING AS ONCE
SHORTWAVE TROF DEPARTS AND THE NEXT SHORTWAVE TROF APPROACHES
SUNDAY AFTERNOON. MAY TRY TO SHOW THIS IN THE GRIDS BETTER AND
FOCUS THE CHC POPS MORE IN THE AFTERNOON PERIOD. ONE MORE DAY WITH
ABOVE NORMAL TEMPS AS READINGS REACH THE MID TO UPR 60S (COOLER
NEAR LAKE MI).
BY THE START OF THE WORK WEEK...THE LONGWAVE TROF IS WELL-
ESTABLISHED OVER THE ROCKIES WITH A DOWNSTREAM UPR RDG OVER
E-CNTRL NORTH AMERICA. PREVAILING SW WINDS WL BRING GULF MOISTURE
INTO WI ON MON AND LIFT BOTH A SFC LOW AND WRMFNT NORTH INTO WI
MON AFTERNOON. FOLLOWED CLOSER TO THE ECMWF MDL HERE AS THE GFS
APPEARS TO EJECT THE MAIN UPR TROF TOO QUICKLY INTO THE PLAINS.
ANOTHER ROUND OF SHWRS/ISOLATED TSTMS FOR NE WI ON MON WITH MAX
TEMPS CLOSER TO NORMAL.
A STRONG UPR JET MAX ROUNDS THE BASE OF THE LONGWAVE TROF BY MON
EVENING AND RACES NEWD THRU THE MIDWEST TO THE UPR MS VALLEY/WRN
GREAT LAKES MON NGT. SHWRS/ISOLATED TSTMS TO CONT MON NGT AS THE
CDFNT PUSHES INTO THE REGION. BY TUE...THE UPR TROF DOES MOVE INTO
THE PLAINS...BUT THE WRN GREAT LAKES TO BE UNDER THE INFLUENCE OF
A DRY SLOT...THUS TUE COULD END UP DRY. MAX TEMPS ON TUE TO AGAIN
BE CLOSE TO NORMAL.
PCPN CHCS TO THEN INCREASE ONCE AGAIN MID-WEEK AS THE UPR TROF
SHIFTS EAST AND SETTLES OVER THE GREAT LAKES. A SERIES OF
SHORTWAVES MOVING THRU THE NOW NW FLOW ALOFT WL BRING UNSETTLED
WEATHER TO NE WI ON WED AND THU. TEMPS WL DROP TO BELOW NORMAL
LEVELS AND WL HAVE TO WATCH N-CNTRL WI WED NGT FOR THE POTENTIAL
OF A RAIN/SNOW MIX AS TEMPS FALL INTO THE MID 30S.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1018 PM CDT THU MAY 8 2014
A WARM FRONT WILL LIFT NORTH ACROSS WISCONSIN TONIGHT...FOLLOWED
BY A COLD FRONTAL PASSAGE FRIDAY MORNING. SCT-NMRS SHRA/TSTM WILL
CONTINUE TO DEVELOP IN ASSOCIATION WITH THESE FRONTAL BOUNDARIES.
INSTABILITY IS FAIRLY WEAK...SO THE THREAT OF WIDESPREAD SVR TSTMS
IS LOW. MVFR CONDITIONS ARE EXPECTED TO ACCOMPANY ANY TSTM
ACTIVITY. THE SHRA/TSRA SHOULD EXIT THE REGION LATE TONIGHT OR
EARLY FRIDAY MORNING. MVFR CIGS WILL MOVE INTO NC/C WI IN THE
WAKE OF THE COLD FRONT ON FRIDAY...AND SHOULD LINGER FOR MOST OF
THE DAY...AND POSSIBLY INTO THE EVENING. SCT SHOWERS ARE ALSO
EXPECTED OVER NC/C WI DURING THE AFTERNOON/EARLY EVG.
LLWS IS EXPECTED TO END IN EASTERN WI EARLY FRIDAY MORNING. GUSTY
SW-W WINDS WILL DEVELOP BEHIND THE FRONT BY MID TO LATE FRIDAY
MORNING.
&&
.MARINE...
ISSUED AT 1030 PM CDT THU MAY 8 2014
WEB CAMS SHOWED AN INCREASE IN MARINE FOG THIS EVENING...ESPECIALLY
TOWARD NORTHPORT. INCREASED THE FOG WORDING IN THE GRIDS/NSH...BUT
HELD OFF ON ANY ADVISORIES.
&&
.HYDROLOGY...
ISSUED AT 330 PM CDT THU MAY 8 2014
THE ABUNDANT MOISTURE FLOWING NWD INTO THE AREA IS STARTING TO
LEAD TO AN INCREASED RISK OF HEAVY RAINS/FLOODING. AT LEAST WE NOW
HAVE THE CREST OF THE SNOWMELT WATER THROUGH THE RIVERS...SO
CAPACITY FOR RUNOFF FROM RAINS IS GREATER THAN A COUPLE WEEKS AGO.
IT/S HARD TO PINPOINT A SPECIFIC RGN OF THE FCST AREA WITH THE
GREATEST RISK OF FLOODING...BUT MOST LIKELY COULD OCCUR OVER EAST-
CENTRAL WISCONSIN LATER TONIGHT AS STORMS BECOME PARALLEL TO THE
MEAN FLOW.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......KIECKBUSCH
MARINE.........KIECKBUSCH
HYDROLOGY......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1021 PM CDT THU MAY 8 2014
.UPDATE...
ISSUED AT 1021 PM CDT THU MAY 8 2014
ONE LAST BATCH OF SHOWERS AND THUNDERSTORMS ARE MOVING ACROSS
SOUTHEAST MINNESOTA AND NORTHEAST IOWA. 0-3KM/MLCAPE HAS BEEN
DROPPING OVER THE PAST FEW HOURS AND EXPECT THAT TREND TO CONTINUE
THROUGH THE REST OF THE NIGHT. BASED ON 09.01Z RAP ANALYSIS...IT
ALSO APPEARS THAT THESE STORMS ARE OCCURRING IN A RELATIVE MINIMUM
OF 0-6KM SHEAR AS WELL. THUS...EXPECT THAT STORMS SHOULD REMAIN
SUB-SEVERE FROM HERE ON OUT THROUGH THE REST OF TONIGHT.
TEMPERATURES WILL REMAIN MILD IN THE UPPER 60S UNTIL THE COLD
FRONT PUSHES THROUGH TOWARD DAYBREAK WITH CONVECTION NOT EXPECTED
ALONG THIS FRONT.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 241 PM CDT THU MAY 8 2014
MAIN FORECAST CONCERNS THIS PERIOD...SHRA/TSRA/SEVERE CHANCES THRU
THIS EVENING...LINGERING -SHRA CHANCES FRI...TEMPERATURES.
18Z DATA ANALYSIS HAD A 1000MB LOW OVER NORTHEAST NEB WITH A TROUGH
NORTHEAST INTO NORTHWEST WI AND WARM FRONT ARCING EAST ACROSS
NORTHERN IA INTO SOUTHERN WI. WARM FRONT CONTINUES TO SEPARATE TO
DISTINCT AIRMASSES...70S WITH DEW POINTS IN THE 60S SOUTH OF THE
WARM FRONT...60S WITH DEW POINTS IN THE 50S. SB CAPE SOUTH OF THE
FRONT IN THE 1500-2500 J/KG RANGE...ELEVATED 500-1000 J/KG NORTH OF
THE WARM FRONT. AREA WSR-88D/S SHOWING CONVECTION DEVELOPING/
EXPANDING ACROSS THE SOUTH HALF OF IA...WITH/AHEAD OF SHORTWAVE
ENERGY LIFTING UP THE EAST SIDE OF THE MID LEVEL LONG WAVE TROUGH.
08.12Z MODELS GENERALLY INITIALIZED WELL. GFS AGAIN ABOUT 5F HIGH
WITH SFC DEW POINTS IN THE MOISTURE PLUME COMING NORTH THRU THE
MID MS VALLEY. SOLUTIONS CONVERGING ON A TIGHT COMPROMISE
CONSENSUS OF THE EARLIER RUNS AS THE TROUGHING/ENERGY OVER THE
ROCKIES/PLAINS LIFTS NORTHEAST THRU THE UPPER MIDWEST TONIGHT
THRU FRI NIGHT. STILL SOME LOWER LEVEL DETAIL DIFFERENCES ON
CONVECTION EVOLUTION THRU THIS EVENING...BUT AFTER THAT SOLUTIONS
QUITE SIMILAR FOR LATER TONIGHT THRU FRI NIGHT AS COOLER/DRIER AIR
SPREADS IN BEHIND THE PASSING LOW/COLD FRONT. FCST CONFIDENCE
GENERALLY GOOD FOR TONIGHT THRU FRI NIGHT.
FOR THE SHORT TERM...AS OF EARLY THIS AFTERNOON...CONVECTIVE SCENARIO
FOR LATER THIS AFTERNOON/THIS EVENING REMAINS IN QUESTION. MAIN FOCUS
FOR TSRA DEVELOPMENT REMAINS WESTERN IA/SOUTHWEST MN...NEAR THE SFC
LOW/TROUGH/FRONTS AND CLOSER TO THE STRONGER SHORTWAVE LIFTING
TOWARD EASTERN SD. SHRA/TSRA DEVELOPING/SPREADING NORTH ACROSS
IA...ALONG WITH THE CLOUD COVER CONSUMING/LIMITING CAPE EARLY THIS
AFTERNOON AND MUDDYING THE TSRA/SEVERE EVOLUTION FOR LATER THIS
AFTERNOON/EVENING. LOWER LEVEL CONVERGENCE/FORCING WOULD POINT TO A
LINE OF STRONG/SEVERE TSRA DEVELOPING IN WESTERN IA/SOUTHWEST MN
THEN LIFTING NORTHEAST ACROSS MN/IA/WI IN THE 21Z-04Z TIME-FRAME.
STRONGEST 0-6KM BULK SHEAR OF 30-60KTS IS OVER THE WEST PORTIONS OF
THE FCST AREA THIS AFTERNOON AND NORTHWEST PORTIONS OF THE FCST AREA
THIS EVENING. SWODY1 SEEMS TO HAVE THE THREATS/RISKS LAYED OUT
WELL...BASED ON CONVECTION LIFTING NORTH ACROSS IA NOT INTERFERING
TOO MUCH. WILL STAY THE COURSE WITH HIGHEST SHRA/TSRA CHANCES LATER
THIS AFTERNOON/EVENING WITH WHAT SHOULD BE A LINE OF CONVECTION
MOVING EAST/NORTHEAST ACROSS THE FCST AREA WITH/AHEAD OF THE SFC-
850MB TROUGH/COLD FRONT. SEE SWODY1 FOR MORE DETAILS ON THE SEVERE
THREATS THRU THIS EVENING.
925-850MB COLD ADVECTION/DRYING SPREAD RATHER QUICKLY ACROSS THE
FCST AREA LATE THIS EVENING/OVERNIGHT AS THE SFC-850MB LOW LIFTS
INTO NORTHEAST MN. PW VALUES OF 1 TO 1.5 INCHES AT 00Z FRI ARE HALF
THAT BY 12Z FRI. THIS AND PASSAGE OF THE SFC-850MB TROUGH/FRONT
SWEEP THE BULK OF THE SHRA/TSRA EAST AND OUT OF THE FCST AREA BY 12Z
FRI. ONLY SOME SMALL LINGERING -SHRA CHANCES IN THE EAST/NORTH ENDS
OF THE FCST AREA BY 12Z FRI. A SECONDARY SHORTWAVE TO LIFT ACROSS
THE AREA FRI AFTERNOON ALONG WITH SOME 850-700MB WRAP-AROUND/
DEFORMATION BAND MOISTURE. DEEPEST OF THIS MOISTURE ACROSS THE NORTH
END OF THE FCST AREA...WITH STEEP LOW LEVEL LAPSE RATES AND WEAK
INSTABILITY TO ABOUT 750MB. CONTINUED THE SMALL -SHRA CHANCES ACROSS
MAINLY THE NORTHEAST 1/3 OF THE FCST AREA THRU FRI AFTERNOON...WHICH
BLENDS WELL WITH NEIGHBORING GRIDS. LOSS OF DIURNAL HEATING AND
PASSING OF THE SECOND SHORTWAVE QUICKLY PUTS AN END TO THIS AND LEFT
FRI NIGHT DRY AS HIGH PRESSURE AND SHORTWAVE RIDGING ALOFT BUILD
INTO THE REGION. A COOLER PERIOD TONIGHT THRU FRI NIGHT AS A COOL
925MB AIRMASS SETTLES OVER THE REGION. WINDS/CLOUDS TO KEEP LOWS
TONIGHT ABOVE NORMAL. BELOW NORMAL HIGHS FRI UNDER THE COOL 925MB
AIRMASS. BELOW NORMAL LOWS FRI NIGHT UNDER MOSTLY CLEAR SKIES/LIGHT
WINDS. USED THE MODEL/ENSEMBLE CONSENSUS LOWS/HIGHS FOR TONIGHT THRU
FRI NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 241 PM CDT THU MAY 8 2014
MAIN FORECAST CONCERNS FOR SAT THRU SUN NIGHT...SHRA/TSRA CHANCES
THRU THE PERIOD AS MORE TROUGHING/SHORTWAVES TAKE AIM AT THE UPPER
MIDWEST.
DECENT AGREEMENT AMONG THE 08.12Z MODELS CONTINUES SAT AS THE NEXT
STRONGER SHORTWAVE TRACKS INTO MN BY LATE IN THE DAY. IMPROVING
CONSENSUS FOR RISING HGTS/SHORTWAVE RIDGING TO BUILD ACROSS THE
UPPER MIDWEST LATER SAT/SAT NIGHT...AHEAD OF THE NEXT STRONG/LONG
WAVE TROUGH TO DIG INTO THE WESTERN CONUS. TREND CONTINUES STRONGER
WITH THIS NEXT TROUGHING INTO THE ROCKIES SAT NIGHT/SUN THEN
EJECTING INTO THE WESTERN PLAINS SUN NIGHT. SHORTWAVE RIDGE AXIS
THAT BUILDS OVER THE REGION SAT NIGHT QUICKLY MOVES EAST SUN...WITH
THE REGION ALREADY UNDER THE INFLUENCE OF SOUTHWEST FLOW ALOFT AHEAD
OF THE NEXT TROUGH FOR SUN AFTERNOON/NIGHT. WITH RUN-TO-RUN
CONSISTENCY AND THE IMPROVING CONSENSUS...SAT THRU SUN NIGHT FCST
CONFIDENCE IS AVERAGE TO GOOD.
BREAK BETWEEN SYSTEMS FRI NIGHT INTO SAT IS BRIEF. THE NEXT
SHORTWAVE INTO MN LATER SAT QUICKLY SPREADS INCREASING LOWER LEVEL
THERMO-DYNAMIC FORCING/LIFT AND INCREASING MOISTURE/THETA-E
CONVERGENCE INTO THE FCST AREA THRU THE DAY ON SAT. INITIAL
MOISTURE/LIFT GOES INTO SATURATION SAT MORNING...WITH INCREASING
SHRA CHANCES INTO SAT AFTERNOON/EVENING AS THE DEEPEST MOISTURE/
STRONGER OF THE LIFT MOVES ACROSS. CARRIED HIGHEST RAIN CHANCES
LATER SAT AFTERNOON/EVENING...THE LOWER LATER SAT NIGHT BEHIND THE
SFC-850MB TROUGH AXIS. INDICATIONS FOR 250 TO AS MUCH AS 1K J/KG MU
CAPE INTO THE AREA AT 00Z SUN SO CONTINUED TSRA MENTION FOR MUCH OF
THE FCST AREA SAT AFTERNOON/EVENING. NEXT BREAK BETWEEN SYSTEMS IS
ALSO RATHER BRIEF LATER SAT NIGHT/SUN MORNING. WITH THE PROGRESSIVE
AND ACTIVE FLOW...THE UPPER MIDWEST IS BACK UNDER SOUTHWEST FLOW
ALOFT SUN AFTERNOON/NIGHT...AHEAD OF STRONG MID LEVEL TROUGHING
SWINGING THRU THE CENTRAL/SOUTHERN ROCKIES. INCREASING MOISTURE/
LIFT/INSTABILITY QUICKLY SPREAD BACK INTO THE FCST AREA FOR SUN
AFTERNOON/NIGHT. PW VALUES IN THE 1 INCH PLUS RANGE BY 00Z MON...
AHEAD OF THE NEXT STRONGER SHORTWAVE AND SFC-850MB LOW LIFTING
NORTHEAST TOWARD/INTO THE UPPER MIDWEST SUN NIGHT. RAISED SHRA/TSRA
CHANCES INTO THE 35-55 PERCENT RANGE SUN AFTERNOON AND 55-70 PERCENT
RANGE SUN NIGHT. SOME LOCALLY HEAVY RAINS POSSIBLE SUN NIGHT...
DEPENDING ON WHERE THE SFC LOW TRACKS/SFC BOUNDARIES SET UP. DUE TO
SOME UNCERTAINTIES WITH WHAT WOULD BE TIMING OF SHRA/TSRA IN/AROUND
THE AREA AND CLOUD COVER...USED THE MODEL/ENSEMBLE CONSENSUS HIGHS/
LOWS FOR SAT THRU SUN NIGHT.
FOR MONDAY THROUGH THURSDAY.../DAYS 4 TO 7/...
MAIN FORECAST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES/RAIN AMOUNTS
MON/MON NIGHT...SHRA CHANCES/COOLER TEMPS TUE-THU.
MEDIUM RANGE MODEL RUNS OF 08.00Z AND 08.12Z ALL SHOW THE SCENARIO
OF STRONG TROUGHING MOVING INTO THE CENTRAL CONUS MON. GFS REMAINS
FASTER THAN ECMWF/CAN-GEM. GOOD CONSENSUS FOR THE STRONG TROUGHING
TO THEN VERY SLOWLY MOVE INTO/ACROSS THE MID/UPPER MS VALLEY TUE
THRU THU...WITH CAN-GEM THE SLOWER/STRONGER OUTLIER BY WED. OVERALL
TREND IS SLOWING AND STRONGER WITH THE MID CONUS TROUGHING NEXT
WEEK. EVEN WITH SOME DIFFERENCES AMONG THE MODELS FOR MON-THU THE
SENSIBLE WEATHER OUTCOMES ARE MORE SIMILAR THAN ONE WOULD USUALLY
EXPECT. DAY 4-7 FCST CONFIDENCE IS AVERAGE WITH RAIN CHANCES THRU
THE PERIOD BUT GOOD FOR BELOW NORMAL TEMPS FOR TUE-THU.
EVEN WITH THE DIFFERENCES ON PROGRESSION OF THE LONG-WAVE TROUGH
ON MON...GOOD CONSENSUS FOR A STRONG PIECE OF ENERGY TO BE LIFTING
NORTHEAST ACROSS THE UPPER MIDWEST MON/MON NIGHT. RATHER STRONG
SFC LOW PROGGED TO ACCOMPANY THIS SHORTWAVE NORTHEAST ACROSS THE
REGION MON. WITH PW VALUES OF AN INCH OR MORE...SHRA/TSRA CHANCES
IN THE 40-65 PERCENT RANGE MON/MON NIGHT LOOK GOOD. POTENTIAL FOR
1 TO 2 INCHES OF RAIN FROM LATER SUN NIGHT THRU MON NIGHT. COLDER
AIR POURS IN FOR TUE THRU THU AS THE THE NORTHERN STREAM PORTION
OF THE MID LEVEL TROUGH SETTLES INTO THE UPPER MIDWEST. 850MB
TEMPS FALL TO A FEW DEGREES EITHER SIDE OF 0C FOR MUCH OF TUE-
THU...SOME 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL. AFTER MORE
NORMAL EARLY MAY TEMPS THROUGH THE WEEKEND...TEMPS FOR TUE-THU
TREND AROUND 10F BELOW NORMAL. WITH THIS COLD CORE OF AIR ALOFT...
STEEP LOW-MID LEVEL LAPSE RATE AND SHORTWAVES ROTATING THRU THE
TROUGH WITH ROUNDS OF INCREASED MOISTURE/FORCING...SMALL -SHRA
CHANCES MUCH OF THE TUE-THU PERIOD REASONABLE FOR NOW. GIVEN THE
TIMING/DETAIL UNCERTAINTIES...DID NOT STRAY MUCH FROM THE MODEL/
ENSEMBLE CONSENSUS HIGHS/LOWS AND RAIN CHANCES FOR DAYS 4-7.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 606 PM CDT THU MAY 8 2014
SCATTERED THUNDERSTORMS ARE DEVELOPING ACROSS PORTIONS OF IOWA
INTO SOUTHERN MINNESOTA AND WESTERN WISCONSIN THIS EVENING.
GENERAL TREND WILL BE FOR AN INCREASE IN COVERAGE UNTIL MID
EVENING...BUT NOT COMPLETELY CLEAR UNTIL FRONTAL PASSAGE AFTER
MIDNIGHT. OUTSIDE OF STORMS...MAINLY MID LEVEL CLOUDS WITH SOME
HAZE BEING REPORTED. BRIEF PERIODS OF IFR CONDITIONS LIKELY WITH
ANY STORM MOVING OVER TAF SITE. THREAT FOR STRONGER TO SEVERE
STORMS WILL BE EARLY ON...THEN SHOULD WANE AS THE EVENING
PROGRESSES. AS SURFACE LOW LIFTS TO THE NORTHEAST...AND IN THE
WAKE OF THE COLD FRONTAL PASSAGE...WRAP AROUND MVFR DECK SLATED
TO COME INTO THE TAF SITES EARLY FRIDAY MORNING. THIS SHOULD PERSIST
FOR THE REMAINDER OF THE PERIOD. GUSTY WEST TO NORTHWEST WINDS UP
TO 25 KTS WILL DEVELOP BY LATE FRIDAY MORNING INTO THE AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 241 PM CDT THU MAY 8 2014
FLOODING CONTINUES ALONG THE MISSISSIPPI RIVER...WITH LOCATIONS
CRESTING BETWEEN GENOA AND LANSING. SHOWERS AND THUNDERSTORMS TODAY
WILL PRODUCE ANYWHERE FROM A HALF INCH TO ONE INCH OF RAIN. THIS
WILL LIKELY SLOW THE FALL FOR LOCATIONS NORTH OF MCGREGOR...AND MAY
INCREASE CRESTS SLIGHTLY SOUTH OF MCGREGOR.
POTENTIAL FOR 1 TO 2 INCHES OF RAINFALL FROM LATE SUN NIGHT THRU
MON EVENING. THIS COULD HAVE ADDITIONAL IMPACTS AND PRODUCE
ADDITIONAL RISES ON AREA RIVERS ALREADY RUNNING HIGH FROM THE
ABOVE AND MUCH ABOVE NORMAL RAINS OF APRIL.
CHECK OUT THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...ZT
HYDROLOGY....RRS
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
937 PM CDT THU MAY 8 2014
.UPDATE...
DYNAMICS DO BECOME MORE FAVORABLE FOR SHOWER/THUNDERSTORM
DEVELOPMENT LATE TONIGHT. UPPER DIVERGENCE INCREASES AS 250 MB JET
MAX OF 100 KNOTS MOVES ACROSS SOUTHERN WISCONSIN. ONE 700 MB JET
MAX OF 45 KNOTS HAS ALREADY LIFTED NORTH INTO NORTHEAST
WISCONSIN...BUT A SECOND 50 KNOT 850/700 MB JET MAX LIFTS OUT OF
ILLINOIS LATE TONIGHT REACHING LOWER MICHIGAN AROUND SUNRISE.
700 MB UPWARD MOTION INCREASES AROUND MIDNIGHT BEFORE MOVING OFF
TO THE EAST BY SUNRISE. ZERO TO 1 KM CAPE OF AROUND 600 JOULES/KG
OVER SOUTH CENTRAL WISCONSIN MOVES INTO THE SOUTHEAST DURING THE
EARLY MORNING HOURS AND WEAKENS A BIT. 00Z NAM AND LATEST HRRR
ALSO INCREASE THE PRECIPITATION.
THEREFORE SHOWERS/THUNDERSTORMS STILL LIKELY. RAP SOUNDINGS
SATURATE SO CAPE LESSENS. STILL CANT RULE OUT A THUNDERSTORM
BRIEFLY REACHING SEVERE CRITERIA.
&&
.AVIATION/06Z TAFS/...
VFR CONDITIONS EXPECTED THIS EVENING. SOME IFR VSBYS POSSIBLE NEAR
LAKE MICHIGAN...MAINLY NORTH OF MILWAUKEE.
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE INTO THE MIDNIGHT
HOUR. THEN EXPECT THE SHOWERS AND SCATTERED THUNDERSTORMS TO
INCREASE IN COVERAGE. MVFR VISIBILITIES AND SOME MVFR CIGS ARE
EXPECTED...WITH GUSTY WINDS AND SMALL HAIL POSSIBLE IN THE
STRONGEST STORMS.
COLD FRONT MOVES EAST THROUGH THE AREA BETWEEN FRIDAY MORNING.
SOUTHWEST WINDS WILL SHIFT TO THE WEST SOUTHWEST...WITH GUSTS TO
20 KNOTS BY FRIDAY AFTERNOON. VFR CONDITIONS EXPECTED.
&&
.PREV DISCUSSION... /ISSUED 335 PM CDT THU MAY 8 2014/
TONIGHT AND FRIDAY...FORECAST CONFIDENCE - MEDIUM.
STREAM OF MIDDLE TO HIGH CLOUDS CONTINUES TO FEED INTO PORTIONS OF
SOUTHERN WISCONSIN FROM THE SOUTHWEST. THERE ARE SOME BREAKS
DEVELOPING ACROSS PORTIONS OF FAR SOUTH CENTRAL AND SOUTHEAST
WISCONSIN. NOT SURE IF THE REST OF THE AREA WILL SEE THESE CLOUDS
MOVE OUT...WHICH WILL LIMIT THE HIGHS AND SUBSEQUENT CAPE VALUES.
WARM AIR ADVECTION IN THE 850 MB TO 700 MB LAYER CONTINUES TO
GENERATE SEVERAL AREAS OF LIGHT SHOWERS ACROSS THE AREA. THESE
SHOULD LINGER AS THEY SHIFT NORTHEASTWARD WITHIN THE WARM AIR
ADVECTION REGIME.
MAIN ISSUE WILL BE TIMING OF CONVECTION INTO TONIGHT...AND SEVERE
STORM CHANCES. MESOSCALE MODELS ARE SHOWING A GENERAL TREND TOWARD
CLUSTERS OF SHOWERS AND STORMS MOVING EAST NORTHEAST THROUGH THE
AREA MAINLY THIS EVENING...LINGERING INTO THE OVERNIGHT HOURS.
HOWEVER...THE CONVECTION CONTINUES TO NOT LOOK VERY ROBUST...AND
EVEN APPEARS TO WEAKEN AS IT MOVES THROUGH THE AREA THIS EVENING.
THE COLD FRONT DOES NOT MOVE THROUGH UNTIL LATER TONIGHT INTO FRIDAY
MORNING. MAIN 500 MB SHORTWAVE TROUGH REMAINS NORTHWEST OF THE
AREA...BUT SEVERAL EMBEDDED VORTICITY MAXIMA SHIFT NORTHEAST THROUGH
THE AREA. 850 MB LOW LEVEL JET ALSO INCREASES TONIGHT ACROSS THE
AREA. THUS...STILL EXPECTING ROUND OF SHOWERS AND STORMS THIS
EVENING INTO THE OVERNIGHT HOURS.
20Z SPC DAY 1 OUTLOOK STILL HAS A SLIGHT RISK FOR SEVERE STORMS
ACROSS THE AREA. THE BEST SHOT WILL BE IN THE WESTERN COUNTIES THIS
EVENING...AS STORMS MOVE INTO THE AREA FROM THE WEST. STORMS MAY
WEAKEN BY THE TIME THEY MAKE IT INTO THE EASTERN PORTIONS OF THE
AREA. STILL...ENOUGH MEAN LAYER CAPE AND DEEP LAYER SHEAR TO SUPPORT
SOME SEVERE STORMS IN THE WESTERN COUNTIES. CIPS ANALOGS AND CWASP
VALUES STILL SUPPORTIVE AS WELL.
FRIDAY NIGHT AND SATURDAY...FORECAST CONFIDENCE - MEDIUM.
WEAK SHORT WAVE RIDGING SHOULD RESULT IN A QUIET NIGHT FRIDAY NIGHT
UNDER CLEAR TO PARTLY CLOUDY SKIES. ON SATURDAY...SHORT TERM MODEL
CONCENSUS ON SHORT WAVE LOW PRESSURE TROUGH TO MOVE EWD ACROSS THE
NORTHERN PLAINS TOWARD WI. HOWEVER DIFFERENCES EXIST IN STRENGTH AND
TIMING OF THIS FEATURE. 12Z NAM MUCH MORE AGGRESSIVE WITH MOISTURE
RETURN AND STRONGER FORCING WHILE GFS AND ECMWF IN REASONABLE
AGREEMENT FOR SLOWER...WEAKER SOLUTION. NAM HAS DEVELOPING LOW
LEVEL JET PIVOTING INTO SRN WI BY 00Z/SUNDAY WHILE ALL OTHER SHORT
TERM GUIDANCE MUCH WEAKER AND FARTHER WEST WITH LLJ AXIS. HENCE
LEANING MORE TOWARD GFS SOLUTION FOR SATURDAY AFTN WITH LESS CHANCE
FOR -SHRA AND LIGHT WINDS TURNING ONSHORE RESULTING IN COOLER AFTN
LAKESHORE TEMPS.
SATURDAY NIGHT AND SUNDAY...FORECAST CONFIDENCE - MEDIUM.
WEAKENING LOW LEVEL JET DOES EVENTUALLY PIVOT EWD ACROSS WI SAT
NIGHT IN ASSOCIATION WITH SHORT WAVE TROUGH MOVING THROUGH THE UPPER
MIDWEST TOWARD LAKE SUPERIOR. BEST CHANCE FOR -SHRA FROM THIS
FEATURE LOOKS TO BE SAT NIGHT. INCREASING LOW TO MID-LEVEL SOUTH
WINDS AHEAD OF SHARPENING UPSTREAM TROUGH WILL BEGIN TO SHIFT
BAROCLINIC ZONE AND WARM FRONT BACK TO THE NORTH LATER SUNDAY INTO
SUNDAY NIGHT. HENCE KEPT SLIGHTLY HIGHER CHANCE POPS FOR THE AFTN
AS THIS FEATURE BEGINS TO SHIFT NWD.
SUNDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE - MEDIUM.
AN UNSETTLED PERIOD LOOKS TO BE SHAPING UP FOR THE FIRST HALF OF THE
EXTENDED PERIOD...THROUGH TUESDAY. INCREASING SOUTH WINDS WILL HELP
WARM FRONT PUSH BACK NORTHWARD INTO SOUTHERN WISCONSIN SUN NIGHT AND
MONDAY. AMPLIFYING UPSTREAM LONG WAVE TROUGH SPREADING INTO THE
CENTRAL CONUS SUNDAY AND MONDAY WILL BE RESPONSIBLE FOR THE SHIFTING
WARM FRONT AND INCREASING SOUTH WINDS.
AS LONG WAVE TROUGH WEAKENS ON MONDAY...PIECE OF MID-LEVEL ENERGY
MOVES NORTHEAST THROUGH THE UPPER MIDWEST AROUND MON NIGHT. LOW
PRESSURE ASSOCIATED WITH UPPER LEVEL SHORT WAVE MOVES ACROSS
WISCONSIN DURING THIS TIME....DRAGGING COLD FRONT THROUGH MONDAY
NIGHT. IFFY ON SEVERE WEATHER RISK...WITH BEST CHANCE IN THE WEST
MON EVE.
ALL EXTENDED GUIDANCE HANGS ON TO UPPER LEVEL TROF LINGERING OVER
UPPER MIDWEST THROUGH MIDDLE OF NEXT WEEK...WHICH WILL KEEP THE
CHANCE FOR LIGHTER SHOWERY PRECIPITATION CONTINUING THROUGH MID-
WEEK. DAYTIME TEMPERATURES FOR THIS PERIOD LOOK TO FALL TO BELOW
SEASONAL NORMAL EARLY NEXT WEEK.
AVIATION/00Z TAFS/...VFR CONDITIONS EXPECTED INTO THE EARLY EVENING
HOURS AT TAF SITES. ON AND OFF GUSTY SOUTH SOUTHWEST WINDS SHOULD
LINGER INTO THE EARLY EVENING.
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE INTO EARLY EVENING.
BEST SHOT FOR STORMS WILL BE IN THE 02Z TO 08Z FRIDAY PERIOD AT
MADISON...AND 03Z TO 11Z FRIDAY PERIOD AT THE EASTERN SITES. MVFR
VISIBILITIES ARE EXPECTED...WITH GUSTY WINDS AND HAIL POSSIBLE IN
THE STRONGEST STORMS.
COLD FRONT MOVES EAST THROUGH THE AREA BETWEEN 09Z AND 16Z FRIDAY.
SOUTHWEST WINDS WILL SHIFT TO THE WEST SOUTHWEST...WITH GUSTS TO 20
KNOTS BY FRIDAY AFTERNOON. SKIES SHOULD BECOME PARTLY TO MOSTLY
SUNNY BY AFTERNOON AS WELL.
MARINE...WEST SOUTHWEST WINDS MAY GUST TO 22 KNOTS AT TIMES
FRIDAY...BEHIND THE DEPARTING COLD FRONT. A SMALL CRAFT ADVISORY MAY
BE NEEDED FOR FRIDAY.
AREAS OF FOG SHOULD LINGER INTO EARLY THIS EVENING NORTH OF PORT
WASHINGTON...UNTIL WARM FRONT MOVES NORTH OF THE AREA. DENSE FOG IS
POSSIBLE...BUT NOT CONFIDENT ENOUGH TO ISSUE A DENSE FOG ADVISORY.
INCREASING SOUTH SOUTHWEST WINDS SHOULD ALLOW THE FOG TO MIX OUT BY
TONIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...HENTZ
TONIGHT/FRIDAY AND AVIATION/MARINE...WOOD
FRIDAY NIGHT THROUGH THURSDAY...MBK
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
728 PM CDT THU MAY 8 2014
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 711 PM CDT THU MAY 8 2014
CERTAINLY NOT GIVING UP ON THE SEVERE POTENTIAL...BUT CURRENT
INDICATIONS SUGGEST THAT A WIDESPREAD EVENT IS NOT LIKELY.
MSAS SFC ANALYSIS SHOWED THAT THE WARM FRONT WAS SITUATED FROM
WEST CENTRAL WI TO AROUND WISCONSIN RAPIDS...OSHKOSH AND
SHEBOYGAN. WIDESPREAD SHOWERS AND TSTMS WERE OCCURRING OVER
THE NW HALF OF WI...AND WERE COMPETING FOR THE MARGINAL
INSTABILITY (MUCAPE 400-800 J/KG) THAT WAS SITUATED ACROSS THE
AREA. TSTMS WERE ALSO BATTLING SOME LINGERING SURFACE-BASED
CONVECTIVE INHIBITION. SHEAR IS QUITE STRONG...WITH 0-6 KM
BULK SHEAR OF 40-50 KTS...AND 0-3 KM SRH OF 200-400...SO
WILL NEED TO MONITOR ANY CELLS THAT BECOME ISOLATED FROM THE
ONGOING CLUSTERS. HAVE SEEN SOME INTERESTING STORM MORPHOLOGY...
INCLUDING A RECENT CELL SPLIT OVER WC WI...AND RESULTING RIGHT-
MOVING SUPERCELL CURRENTLY MOVG THROUGH NW JACKSON COUNTY.
DESPITE A LARGE NUMBERS OF ONGOING STORMS OVER MN/IA AND WSTRN
WI...THERE ARE RELATIVELY FEW WARNINGS CURRENTLY IN EFFECT.
CURRENT INDICATIONS SUGGEST THAT A WIDESPREAD SVR EVENT IS NOT
LIKELY...BUT LOCAL SUPERCELLS OR SHORT LINE SEGMENTS MAY POSE AN
ISOLD SVR THREAT...LARGE HAIL AND DAMAGING WINDS...THROUGH THE
NIGHT.
&&
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 330 PM CDT THU MAY 8 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
CENTERED OVER EASTERN NEBRASKA AND A WARM FRONT SNAKING ITS WAY
FROM JUST SOUTH OF MINNEAPOLIS TO VOLK FIELD TO WEST BEND
WISCONSIN. OCCASIONAL LIGHT SHOWERS CONTINUE TO REDEVELOP OVER THE
WARM FRONT...WHICH HAVE BEEN MAINLY IMPACTING CENTRAL TO NORTHEAST
WISCONSIN. BUT WITH THE FORWARD MOTION OF FRONT AT A SNAILS
PACE...INSTABILITY HAS BEEN SLOW TO DEVELOP THIS AFTERNOON.
ADDITIONAL LIGHT SHOWERS ASSOCIATED WITH A WEAK SHORTWAVE ARE ALSO
MOVING NORTHEAST OVER SOUTHERN WISCONSIN AND WILL MOVE INTO THE
FOX VALLEY OVER THE NEXT HOUR OR TWO. THIS WAVE WAS PRODUCING
THUNDERSTORMS OVER IOWA EARLIER BUT THOSE HAVE SINCE WEAKENED. THE
MAIN SHOW HOWEVER...IS OCCURRING OVER MINNESOTA AND NORTHERN IOWA
WHERE STRONG TO SEVERE THUNDERSTORMS ARE OCCURRING ALONG AN UPPER
LEVEL FRONT. AS THIS FRONT MOVES EAST...CHANCES OF SEVERE WEATHER
ARE THE MAIN FORECAST CONCERN.
TONIGHT...LOW PRESSURE WILL BE TRAVELING FROM SOUTHWEST MINNESOTA
TO THE WESTERN TIP OF LAKE SUPERIOR. POTENTIAL WILL REMAIN FOR THE
WARM FRONT TO BOW NORTHWARD ACROSS CENTRAL AND NORTH-CENTRAL
WISCONSIN THIS EVENING DUE STRENGTHENING SOUTHERLY FLOW AHEAD OF THE
LOW. HOW FAR NORTH IS STILL QUESTIONABLE GIVEN THE SCATTERED SHOWER
ACTIVITY...CLOUD COVER...AND EASTERLY FLOW. SHORTWAVE OVER EASTERN
IOWA WILL BE LIFTING NE ACROSS THE FORECAST AREA LATE THIS AFTERNOON
INTO THE EVENING AT PEAK HEATING. THINKING SCT SHOWERS AND ISOLD
TSTORMS WILL CONTINUE TO BE GENERATED FROM THIS WAVE...THAT COULD
HELP TO KEEP THE WARM FRONT FARTHER SOUTH THAN MODELS DEPICT. IF ANY
STORMS DEVELOP...40-50KTS OF BULK SHEAR WILL SUPPORT A CHANCE OF
LARGE HAIL AND DAMAGING WINDS...TO A LESSER EXTENT.. THEN ATTENTION
WILL TURN TO SEVERE THUNDERSTORMS WHICH ARE EXPECTED TO DEVELOP
LATER THIS AFTERNOON OVER MINNESOTA AND IOWA. THE LATEST SHORT
RANGE GUIDANCE SHOWS THIS CONVECTION...IN THE FORM OF LINE
SEGMENTS...MOVING INTO CENTRAL AND NORTH-CENTRAL WISCONSIN BY
MID-EVENING. CONVERGENCE ALONG THE UPPER LEVEL TROUGH AND UPPER
CONVERGENCE WILL PROVIDE DECENT FORCING FOR STORMS TO SUSTAIN
THEMSELVES. RATHER DIFFICULT TO GET GAUGE ON INSTABILITY SINCE
PROGGED SOUNDINGS ARE EITHER CONTAMINATED WITH CONVECTION OR NOT
REPRESENTATIVE OF THE CURRENT ENVIRONMENT. BUT ELEVATED CAPES ARE
GENERALLY AROUND 1K J/KG AND THATS A DECENT PLACE TO START. STEEP
MID-LEVEL LAPSE RATES AROUND 7 C/KM AND BULK SHEARS IN THE 35-40 KT
RANGE WILL SUPPORT A LARGE HAIL AND DAMAGING WIND THREAT. CHANCES
OF SEVERE THUNDERSTORMS LOOK BETTER OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN AS INSTABILITY DIMINISHES TO THE EAST. THE STORMS SHOULD
EXIT LATE OVERNIGHT...BUT ADDITIONAL SPOTTY SHOWERS AND STORMS COULD
STILL POP UP ALONG THE TRAILING SURFACE COLD FRONT. TEMPS WILL BE
WARM TONIGHT AND RANGE MAINLY FROM THE MID 50S TO LOW 60S.
FRIDAY...THE SURFACE COLD FRONT WILL EXIT EASTERN WISCONSIN BY
MID-MORNING...AND COULD SEE A PERIOD OF CLEARING OCCUR RIGHT BEHIND
THE FRONT AND BENEATH THE DRY SLOT. THEN SHOULD SEE WRAP AROUND
MOISTURE PUSH EAST ACROSS CENTRAL AND NORTH-CENTRAL WISCONSIN
THROUGH THE REST OF THE DAY. PROGGED SOUNDINGS SHOW A STRONG
INVERSION AT ABOUT 750MB...SO TONED BACK THE CHANCE OF SHOWERS OVER
CENTRAL AND NORTH-CENTRAL WISCONSIN SOME. AIR BEHIND THE FRONT IS
NOT ALL THAT COLD...AND KEPT TEMPERATURES RANGING FROM THE LOW 60S
WEST TO NEAR 70 NORTHEAST.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 330 PM CDT THU MAY 8 2014
LARGE SCALE MEAN FLOW IS EXPECTED TO BRIEFLY DEAMPLIFY THIS
WEEKEND BEFORE RE-AMPLIFYING EARLY NEXT WEEK AS UPR RIDGING OCCURS
OVER THE WEST COAST AND AN EWD MOVING LONGWAVE TROF SHIFTS FROM
THE CNTRL CONUS TO E-CNTRL NORTH AMERICA. PCPN CHCS TO BE
ASSOCIATED FIRST WITH A WEAK IMPULSE EJECTED NE FROM THE MEAN UPR
TROF DURING THE LATTER PART OF THE WEEKEND AND THEN EARLY NEXT
WEEK WITIH THE APPROACH OF THE UPR TROF AND THE MAIN SFC CYCLONE/
CDFNT. TEMPS ARE FCST TO GO FROM SLIGHTLY ABOVE NORMAL EARLY...TO
BELOW NORMAL BY MID-WEEK AS THE MEAN FLOW TURNS NW.
ANY LINGERING LIGHT SHWRS OVER NRN WI SHOULD GRADUALLY COME TO AN
END FRI EVENING AS THE SHORTWAVE TROF CONTS TO TRACK NE INTO SRN
ONTARIO. OTHERWISE...THE MDLS INDICATE A WEAK SFC RDG/RISING UPR
HEIGHTS WORKING EAST TOWARD THE WRN GREAT LAKES DURING THE OVRNGT
HOURS. DECREASING CLOUDS WITH DIMINISHING WINDS COULD SEND TEMPS
DOWN INTO THE 35-40 DEG RANGE NORTH...LWR TO MID 40S SOUTH.
SFC RDG MOVES ACROSS NE WI SAT MORNING AND BE TO OUR EAST BY SAT
AFTERNOON. MEANWHILE TO OUR WEST...A PIECE OF SHORTWAVE ENERGY IS
PROGGED TO EJECT EWD FROM THE DEVELOPING WRN CONUS UPR TROF AND
ALREADY BY PUSHING INTO THE UPR MS VALLEY BY 00Z SUNDAY. CLOUDS
SHOULD ALREADY BEGIN TO INCREASE INTO CNTRL WI SAT AFTERNOON...
BUT WL KEEP PCPN OUT OF THE FCST FOR NOW. MAX TEMPS TO REMAIN A
LITTLE ABOVE NORMAL AS WINDS ATTEMPT TO BACK TO THE SOUTH ONCE
AGAIN AHEAD OF THE APPROACHING SHORTWAVE TROF.
THIS SHORTWAVE TROF TO THEN RACE ACROSS WI SAT NGT...THEREBY
BRINGING A CHC OF SHWRS TO THE ENTIRE FCST AREA. INSTABILITY LOOKS
MARGINAL RIGHT NOW AND MAY GENERATE AN ISOLATED TSTM OR TWO ACROSS
CNTRL/E-CNTRL WI. PLENTY OF CLOUDS/PCPN IN THE VCNTY WL HOLD MIN
TEMPS IN THE MID TO UPR 40S NORTH...UPR 40S TO LWR 50 SOUTH. THERE
MAY NOW BE A BRIEF BREAK IN THE PCPN CHCS SUNDAY MORNING AS ONCE
SHORTWAVE TROF DEPARTS AND THE NEXT SHORTWAVE TROF APPROACHES
SUNDAY AFTERNOON. MAY TRY TO SHOW THIS IN THE GRIDS BETTER AND
FOCUS THE CHC POPS MORE IN THE AFTERNOON PERIOD. ONE MORE DAY WITH
ABOVE NORMAL TEMPS AS READINGS REACH THE MID TO UPR 60S (COOLER
NEAR LAKE MI).
BY THE START OF THE WORK WEEK...THE LONGWAVE TROF IS WELL-
ESTABLISHED OVER THE ROCKIES WITH A DOWNSTREAM UPR RDG OVER
E-CNTRL NORTH AMERICA. PREVAILING SW WINDS WL BRING GULF MOISTURE
INTO WI ON MON AND LIFT BOTH A SFC LOW AND WRMFNT NORTH INTO WI
MON AFTERNOON. FOLLOWED CLOSER TO THE ECMWF MDL HERE AS THE GFS
APPEARS TO EJECT THE MAIN UPR TROF TOO QUICKLY INTO THE PLAINS.
ANOTHER ROUND OF SHWRS/ISOLATED TSTMS FOR NE WI ON MON WITH MAX
TEMPS CLOSER TO NORMAL.
A STRONG UPR JET MAX ROUNDS THE BASE OF THE LONGWAVE TROF BY MON
EVENING AND RACES NEWD THRU THE MIDWEST TO THE UPR MS VALLEY/WRN
GREAT LAKES MON NGT. SHWRS/ISOLATED TSTMS TO CONT MON NGT AS THE
CDFNT PUSHES INTO THE REGION. BY TUE...THE UPR TROF DOES MOVE INTO
THE PLAINS...BUT THE WRN GREAT LAKES TO BE UNDER THE INFLUENCE OF
A DRY SLOT...THUS TUE COULD END UP DRY. MAX TEMPS ON TUE TO AGAIN
BE CLOSE TO NORMAL.
PCPN CHCS TO THEN INCREASE ONCE AGAIN MID-WEEK AS THE UPR TROF
SHIFTS EAST AND SETTLES OVER THE GREAT LAKES. A SERIES OF
SHORTWAVES MOVING THRU THE NOW NW FLOW ALOFT WL BRING UNSETTLED
WEATHER TO NE WI ON WED AND THU. TEMPS WL DROP TO BELOW NORMAL
LEVELS AND WL HAVE TO WATCH N-CNTRL WI WED NGT FOR THE POTENTIAL
OF A RAIN/SNOW MIX AS TEMPS FALL INTO THE MID 30S.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 625 PM CDT THU MAY 8 2014
A WARM FRONT WILL LIFT NORTH ACROSS WISCONSIN TONIGHT...FOLLOWED
BY A COLD FRONTAL PASSAGE FRIDAY MORNING. PERIODS OF SHOWERS AND
TSTMS WILL DEVELOP IN ASSOCIATION WITH THESE FRONTAL BOUNDARIES.
THE THREAT OF WIDESPREAD SVR TSTMS SEEMS LIMITED DUE TO A LACK OF
STRONG INSTABILITY...BUT ISOLD SVR TSTMS WILL BE POSSIBLE. MVFR
CONDITIONS ARE EXPECTED WITH THE TSTM ACTIVITY. THE SHRA/TSRA
SHOULD EXIT THE REGION LATE TONIGHT OR EARLY FRIDAY MORNING. MVFR
CIGS WILL LIKELY AFFECT MUCH OF NC/C WI ON FRIDAY...ALONG WITH SCT
SHOWERS DURING THE AFTERNOON.
LLWS IS EXPECTED THIS EVENING INTO THE EARLY OVERNIGHT HOURS...
ESPECIALLY C/NE/EC WI. GUSTY SW-W WINDS WILL DEVELOP BEHIND THE
FRONT BY MID TO LATE FRIDAY MORNING.
&&
.MARINE...
ISSUED AT 330 PM CDT THU MAY 8 2014
FOG HAS BEEN SLOW TO FORM SO FAR TODAY DESPITE WARMER AND MORE
MOIST AIR INVADING THE REGION. WILL JUST KEEP A PATCHY MENTION IN
THE FORECAST UNTIL A MORE CERTAIN TREND IS OBSERVED.
&&
.HYDROLOGY...
ISSUED AT 330 PM CDT THU MAY 8 2014
THE ABUNDANT MOISTURE FLOWING NWD INTO THE AREA IS STARTING TO
LEAD TO AN INCREASED RISK OF HEAVY RAINS/FLOODING. AT LEAST WE NOW
HAVE THE CREST OF THE SNOWMELT WATER THROUGH THE RIVERS...SO
CAPACITY FOR RUNOFF FROM RAINS IS GREATER THAN A COUPLE WEEKS AGO.
IT/S HARD TO PINPOINT A SPECIFIC RGN OF THE FCST AREA WITH THE
GREATEST RISK OF FLOODING...BUT MOST LIKELY COULD OCCUR OVER EAST-
CENTRAL WISCONSIN LATER TONIGHT AS STORMS BECOME PARALLEL TO THE
MEAN FLOW.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......KIECKBUSCH
MARINE.........MPC
HYDROLOGY......MPC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
635 PM CDT THU MAY 8 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 330 PM CDT THU MAY 8 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW PRESSURE
CENTERED OVER EASTERN NEBRASKA AND A WARM FRONT SNAKING ITS WAY
FROM JUST SOUTH OF MINNEAPOLIS TO VOLK FIELD TO WEST BEND
WISCONSIN. OCCASIONAL LIGHT SHOWERS CONTINUE TO REDEVELOP OVER THE
WARM FRONT...WHICH HAVE BEEN MAINLY IMPACTING CENTRAL TO NORTHEAST
WISCONSIN. BUT WITH THE FORWARD MOTION OF FRONT AT A SNAILS
PACE...INSTABILITY HAS BEEN SLOW TO DEVELOP THIS AFTERNOON.
ADDITIONAL LIGHT SHOWERS ASSOCIATED WITH A WEAK SHORTWAVE ARE ALSO
MOVING NORTHEAST OVER SOUTHERN WISCONSIN AND WILL MOVE INTO THE
FOX VALLEY OVER THE NEXT HOUR OR TWO. THIS WAVE WAS PRODUCING
THUNDERSTORMS OVER IOWA EARLIER BUT THOSE HAVE SINCE WEAKENED. THE
MAIN SHOW HOWEVER...IS OCCURRING OVER MINNESOTA AND NORTHERN IOWA
WHERE STRONG TO SEVERE THUNDERSTORMS ARE OCCURRING ALONG AN UPPER
LEVEL FRONT. AS THIS FRONT MOVES EAST...CHANCES OF SEVERE WEATHER
ARE THE MAIN FORECAST CONCERN.
TONIGHT...LOW PRESSURE WILL BE TRAVELING FROM SOUTHWEST MINNESOTA
TO THE WESTERN TIP OF LAKE SUPERIOR. POTENTIAL WILL REMAIN FOR THE
WARM FRONT TO BOW NORTHWARD ACROSS CENTRAL AND NORTH-CENTRAL
WISCONSIN THIS EVENING DUE STRENGTHENING SOUTHERLY FLOW AHEAD OF THE
LOW. HOW FAR NORTH IS STILL QUESTIONABLE GIVEN THE SCATTERED SHOWER
ACTIVITY...CLOUD COVER...AND EASTERLY FLOW. SHORTWAVE OVER EASTERN
IOWA WILL BE LIFTING NE ACROSS THE FORECAST AREA LATE THIS AFTERNOON
INTO THE EVENING AT PEAK HEATING. THINKING SCT SHOWERS AND ISOLD
TSTORMS WILL CONTINUE TO BE GENERATED FROM THIS WAVE...THAT COULD
HELP TO KEEP THE WARM FRONT FARTHER SOUTH THAN MODELS DEPICT. IF ANY
STORMS DEVELOP...40-50KTS OF BULK SHEAR WILL SUPPORT A CHANCE OF
LARGE HAIL AND DAMAGING WINDS...TO A LESSER EXTENT.. THEN ATTENTION
WILL TURN TO SEVERE THUNDERSTORMS WHICH ARE EXPECTED TO DEVELOP
LATER THIS AFTERNOON OVER MINNESOTA AND IOWA. THE LATEST SHORT
RANGE GUIDANCE SHOWS THIS CONVECTION...IN THE FORM OF LINE
SEGMENTS...MOVING INTO CENTRAL AND NORTH-CENTRAL WISCONSIN BY
MID-EVENING. CONVERGENCE ALONG THE UPPER LEVEL TROUGH AND UPPER
CONVERGENCE WILL PROVIDE DECENT FORCING FOR STORMS TO SUSTAIN
THEMSELVES. RATHER DIFFICULT TO GET GAUGE ON INSTABILITY SINCE
PROGGED SOUNDINGS ARE EITHER CONTAMINATED WITH CONVECTION OR NOT
REPRESENTATIVE OF THE CURRENT ENVIRONMENT. BUT ELEVATED CAPES ARE
GENERALLY AROUND 1K J/KG AND THATS A DECENT PLACE TO START. STEEP
MID-LEVEL LAPSE RATES AROUND 7 C/KM AND BULK SHEARS IN THE 35-40 KT
RANGE WILL SUPPORT A LARGE HAIL AND DAMAGING WIND THREAT. CHANCES
OF SEVERE THUNDERSTORMS LOOK BETTER OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN AS INSTABILITY DIMINISHES TO THE EAST. THE STORMS SHOULD
EXIT LATE OVERNIGHT...BUT ADDITIONAL SPOTTY SHOWERS AND STORMS COULD
STILL POP UP ALONG THE TRAILING SURFACE COLD FRONT. TEMPS WILL BE
WARM TONIGHT AND RANGE MAINLY FROM THE MID 50S TO LOW 60S.
FRIDAY...THE SURFACE COLD FRONT WILL EXIT EASTERN WISCONSIN BY
MID-MORNING...AND COULD SEE A PERIOD OF CLEARING OCCUR RIGHT BEHIND
THE FRONT AND BENEATH THE DRY SLOT. THEN SHOULD SEE WRAP AROUND
MOISTURE PUSH EAST ACROSS CENTRAL AND NORTH-CENTRAL WISCONSIN
THROUGH THE REST OF THE DAY. PROGGED SOUNDINGS SHOW A STRONG
INVERSION AT ABOUT 750MB...SO TONED BACK THE CHANCE OF SHOWERS OVER
CENTRAL AND NORTH-CENTRAL WISCONSIN SOME. AIR BEHIND THE FRONT IS
NOT ALL THAT COLD...AND KEPT TEMPERATURES RANGING FROM THE LOW 60S
WEST TO NEAR 70 NORTHEAST.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 330 PM CDT THU MAY 8 2014
LARGE SCALE MEAN FLOW IS EXPECTED TO BRIEFLY DEAMPLIFY THIS
WEEKEND BEFORE RE-AMPLIFYING EARLY NEXT WEEK AS UPR RIDGING OCCURS
OVER THE WEST COAST AND AN EWD MOVING LONGWAVE TROF SHIFTS FROM
THE CNTRL CONUS TO E-CNTRL NORTH AMERICA. PCPN CHCS TO BE
ASSOCIATED FIRST WITH A WEAK IMPULSE EJECTED NE FROM THE MEAN UPR
TROF DURING THE LATTER PART OF THE WEEKEND AND THEN EARLY NEXT
WEEK WITIH THE APPROACH OF THE UPR TROF AND THE MAIN SFC CYCLONE/
CDFNT. TEMPS ARE FCST TO GO FROM SLIGHTLY ABOVE NORMAL EARLY...TO
BELOW NORMAL BY MID-WEEK AS THE MEAN FLOW TURNS NW.
ANY LINGERING LIGHT SHWRS OVER NRN WI SHOULD GRADUALLY COME TO AN
END FRI EVENING AS THE SHORTWAVE TROF CONTS TO TRACK NE INTO SRN
ONTARIO. OTHERWISE...THE MDLS INDICATE A WEAK SFC RDG/RISING UPR
HEIGHTS WORKING EAST TOWARD THE WRN GREAT LAKES DURING THE OVRNGT
HOURS. DECREASING CLOUDS WITH DIMINISHING WINDS COULD SEND TEMPS
DOWN INTO THE 35-40 DEG RANGE NORTH...LWR TO MID 40S SOUTH.
SFC RDG MOVES ACROSS NE WI SAT MORNING AND BE TO OUR EAST BY SAT
AFTERNOON. MEANWHILE TO OUR WEST...A PIECE OF SHORTWAVE ENERGY IS
PROGGED TO EJECT EWD FROM THE DEVELOPING WRN CONUS UPR TROF AND
ALREADY BY PUSHING INTO THE UPR MS VALLEY BY 00Z SUNDAY. CLOUDS
SHOULD ALREADY BEGIN TO INCREASE INTO CNTRL WI SAT AFTERNOON...
BUT WL KEEP PCPN OUT OF THE FCST FOR NOW. MAX TEMPS TO REMAIN A
LITTLE ABOVE NORMAL AS WINDS ATTEMPT TO BACK TO THE SOUTH ONCE
AGAIN AHEAD OF THE APPROACHING SHORTWAVE TROF.
THIS SHORTWAVE TROF TO THEN RACE ACROSS WI SAT NGT...THEREBY
BRINGING A CHC OF SHWRS TO THE ENTIRE FCST AREA. INSTABILITY LOOKS
MARGINAL RIGHT NOW AND MAY GENERATE AN ISOLATED TSTM OR TWO ACROSS
CNTRL/E-CNTRL WI. PLENTY OF CLOUDS/PCPN IN THE VCNTY WL HOLD MIN
TEMPS IN THE MID TO UPR 40S NORTH...UPR 40S TO LWR 50 SOUTH. THERE
MAY NOW BE A BRIEF BREAK IN THE PCPN CHCS SUNDAY MORNING AS ONCE
SHORTWAVE TROF DEPARTS AND THE NEXT SHORTWAVE TROF APPROACHES
SUNDAY AFTERNOON. MAY TRY TO SHOW THIS IN THE GRIDS BETTER AND
FOCUS THE CHC POPS MORE IN THE AFTERNOON PERIOD. ONE MORE DAY WITH
ABOVE NORMAL TEMPS AS READINGS REACH THE MID TO UPR 60S (COOLER
NEAR LAKE MI).
BY THE START OF THE WORK WEEK...THE LONGWAVE TROF IS WELL-
ESTABLISHED OVER THE ROCKIES WITH A DOWNSTREAM UPR RDG OVER
E-CNTRL NORTH AMERICA. PREVAILING SW WINDS WL BRING GULF MOISTURE
INTO WI ON MON AND LIFT BOTH A SFC LOW AND WRMFNT NORTH INTO WI
MON AFTERNOON. FOLLOWED CLOSER TO THE ECMWF MDL HERE AS THE GFS
APPEARS TO EJECT THE MAIN UPR TROF TOO QUICKLY INTO THE PLAINS.
ANOTHER ROUND OF SHWRS/ISOLATED TSTMS FOR NE WI ON MON WITH MAX
TEMPS CLOSER TO NORMAL.
A STRONG UPR JET MAX ROUNDS THE BASE OF THE LONGWAVE TROF BY MON
EVENING AND RACES NEWD THRU THE MIDWEST TO THE UPR MS VALLEY/WRN
GREAT LAKES MON NGT. SHWRS/ISOLATED TSTMS TO CONT MON NGT AS THE
CDFNT PUSHES INTO THE REGION. BY TUE...THE UPR TROF DOES MOVE INTO
THE PLAINS...BUT THE WRN GREAT LAKES TO BE UNDER THE INFLUENCE OF
A DRY SLOT...THUS TUE COULD END UP DRY. MAX TEMPS ON TUE TO AGAIN
BE CLOSE TO NORMAL.
PCPN CHCS TO THEN INCREASE ONCE AGAIN MID-WEEK AS THE UPR TROF
SHIFTS EAST AND SETTLES OVER THE GREAT LAKES. A SERIES OF
SHORTWAVES MOVING THRU THE NOW NW FLOW ALOFT WL BRING UNSETTLED
WEATHER TO NE WI ON WED AND THU. TEMPS WL DROP TO BELOW NORMAL
LEVELS AND WL HAVE TO WATCH N-CNTRL WI WED NGT FOR THE POTENTIAL
OF A RAIN/SNOW MIX AS TEMPS FALL INTO THE MID 30S.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 625 PM CDT THU MAY 8 2014
A WARM FRONT WILL LIFT NORTH ACROSS WISCONSIN TONIGHT...FOLLOWED
BY A COLD FRONTAL PASSAGE FRIDAY MORNING. PERIODS OF SHOWERS AND
TSTMS WILL DEVELOP IN ASSOCIATION WITH THESE FRONTAL BOUNDARIES.
THE THREAT OF WIDESPREAD SVR TSTMS SEEMS LIMITED DUE TO A LACK OF
STRONG INSTABILITY...BUT ISOLD SVR TSTMS WILL BE POSSIBLE. MVFR
CONDITIONS ARE EXPECTED WITH THE TSTM ACTIVITY. THE SHRA/TSRA
SHOULD EXIT THE REGION LATE TONIGHT OR EARLY FRIDAY MORNING. MVFR
CIGS WILL LIKELY AFFECT MUCH OF NC/C WI ON FRIDAY...ALONG WITH SCT
SHOWERS DURING THE AFTERNOON.
LLWS IS EXPECTED THIS EVENING INTO THE EARLY OVERNIGHT HOURS...
ESPECIALLY C/NE/EC WI. GUSTY SW-W WINDS WILL DEVELOP BEHIND THE
FRONT BY MID TO LATE FRIDAY MORNING.
&&
.MARINE...
ISSUED AT 330 PM CDT THU MAY 8 2014
FOG HAS BEEN SLOW TO FORM SO FAR TODAY DESPITE WARMER AND MORE
MOIST AIR INVADING THE REGION. WILL JUST KEEP A PATCHY MENTION IN
THE FORECAST UNTIL A MORE CERTAIN TREND IS OBSERVED.
&&
.HYDROLOGY...
ISSUED AT 330 PM CDT THU MAY 8 2014
THE ABUNDANT MOISTURE FLOWING NWD INTO THE AREA IS STARTING TO
LEAD TO AN INCREASED RISK OF HEAVY RAINS/FLOODING. AT LEAST WE NOW
HAVE THE CREST OF THE SNOWMELT WATER THROUGH THE RIVERS...SO
CAPACITY FOR RUNOFF FROM RAINS IS GREATER THAN A COUPLE WEEKS AGO.
IT/S HARD TO PINPOINT A SPECIFIC RGN OF THE FCST AREA WITH THE
GREATEST RISK OF FLOODING...BUT MOST LIKELY COULD OCCUR OVER EAST-
CENTRAL WISCONSIN LATER TONIGHT AS STORMS BECOME PARALLEL TO THE
MEAN FLOW.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......KIECKBUSCH
MARINE.........MPC
HYDROLOGY......MPC
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 253 PM CDT WED MAY 7 2014
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW LOW
PRESSURE OVER THE KANSAS/NEBRASKA BORDER WITH A WARM FRONT EXTENDING
EAST FROM NORTHERN IOWA ACROSS NORTHERN ILLINOIS TO THE CENTRAL
APPALACHIANS. NORTH OF THIS WARM FRONT...A SHORTWAVE TURNED MCV IS
EXITING THE STATE OVER NORTHERN LAKE MICHIGAN. WAKE LOW WINDS HAVE
SUBSIDED BEHIND THIS MCV...BUT SCATTERED CONVECTION CONTINUES TO
REDEVELOP FROM WAUSAU TO MANITOWOC IN A REGION OF MID-LEVEL FGEN AND
MOISTURE CONVERGENCE ALONG AN 850MB WARM FRONT. THINK THIS
CONVECTION WILL LIFT NORTHEAST AND WEAKEN FOR THE REST OF THIS
AFTERNOON WHICH SHOULD LEAD TO A PERIOD OF RELATIVELY QUIET
CONDITIONS INTO THIS EVENING. LOOKING UPSTREAM...CONVECTION IS
DEVELOPING OVER THE EASTERN DAKOTAS AND WESTERN MINNESOTA ALONG AN
INVERTED TROUGH. TOUGH TO PICK OUT ANY NOTABLE SHORTWAVES IN THE
SOUTHWEST FLOW ALOFT OVER THE PLAINS TO KEY ON FOR PRECIP TONIGHT.
WITH BROAD WARM AND MOIST ADVECTION CONTINUE OVER THE NEXT 24
HOURS...THUNDERSTORM AND SEVERE WEATHER CHANCES ARE THE MAIN
FORECAST CONCERNS.
TONIGHT...AS LOW PRESSURE MOVES INTO THE CENTRAL GREAT PLAINS...AN
850MB WARM FRONT WILL BE LIFTING NORTHWARD ACROSS CENTRAL AND
NORTHERN WISCONSIN DURING THE EVENING. THOUGH A PERIOD OF
SUBSIDENCE MAY STILL BE ONGOING BEHIND THE MCV THAT IS EXITING
NORTHEAST WISCONSIN CURRENTLY...ASCENT OVER THIS WARM FRONT ON THE
EDGE OF THE ELEVATED MIXED LAYER SHOULD EVENTUALLY LEAD TO A
RE-DEVELOPMENT OF SHOWERS AND THUNDERSTORMS OVER FAR NORTHERN
WISCONSIN AND THE UPPER PENINSULA. WITH NO DISCERNIBLE SHORTWAVES
UPSTREAM...TIMING OF RE-DEVELOPMENT IS TOUGH TO GET A HANDLE ON...SO
KEPT PROBABILITIES IN THE CHANCE RANGE THIS EVENING...AND INCREASED
THEM TO LIKELY OVERNIGHT. DUE TO STEEP MID-LEVEL LAPSE RATES IN THE
7-8 C/KM RANGE...ELEVATED CAPES UPWARDS OF 1100 J/KG...AND 0-6 KM
BULK SHEARS OF 30-35 KTS...TOUGH TO RULE OUT A MINOR SEVERE THREAT.
LARGE HAIL WILL BE THE MAIN THREAT AND DAMAGING WINDS TO A LESSER
EXTENT.
THURSDAY...LOW PRESSURE WILL LIFT NORTHEAST TOWARDS SOUTH-CENTRAL
MINNESOTA. AT THE SAME TIME...A SURFACE WARM FRONT WILL BE SHIFTING
NORTHWARD ACROSS THE STATE. HOW QUICKLY THAT WARM FRONT MOVES NORTH
IS A BIG QUESTION MARK AS ITS FORWARD PROGRESS WILL LIKELY BE
IMPEDED BY MORNING CONVECTION AND CLOUD COVER. IF CLOUDS AND
RAINFALL CONTINUE INTO THE AFTERNOON...HAVE A TOUGH TIME SEEING THIS WARM
FRONT REACHING THE UPPER PENINSULA BORDER BY 00Z FRI. THE 12Z ECMWF
SHOWS THIS WARM FRONT ONLY REACHING THE ROUTE 29 CORRIDOR BY THIS
TIME SO THIS SCENARIO IS NOT OUT OF REALM OF POSSIBILITY. WILL SHOW
LIKELY POPS OVER N-C WISCONSIN DURING THE MORNING AND A CHANCE
EVERYWHERE ELSE AS ISENTROPIC ASCENT CONTINUES. CENTRAL WISCONSIN
AND THE FOX VALLEY HAVE THE BEST CHANCE OF CLEARING THE WARM FRONT
DURING THE AFTERNOON WHERE TEMPS HAVE POTENTIAL TO REACH INTO THE
UPPER 70S TO LOWER 80S. WITH SURFACE DEWPOINTS RISING INTO THE
LOWER 60S...ML CAPES WILL RANGE FROM 1500-2000 J/KG OVER CENTRAL
WISCONSIN AND THE SOUTHERN FOX VALLEY. 0-6KM BULK SHEAR WILL BE
MORE THAN SUFFICIENT FOR THE POSSIBILITY OF DISCRETE CELLS AND WILL
HAVE FORCING VIA ISENTROPIC/MOISTURE ADVECTION. LARGE SCALE FORCING
WILL STILL BE A CONSIDERABLE DISTANCE TO THE WEST...SO SEVERE
WEATHER CHANCES MAY GET DELAYED INTO THE EVENING...BUT CANNOT RULE
OUT A FEW SEVERE THUNDERSTORMS TOMORROW AFTERNOON. THE MAIN THREATS
WILL BE DAMAGING WINDS AND LARGE HAIL. NO SIGNIFICANT CHANGES TO
TEMPS.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 253 PM CDT WED MAY 7 2014
LOW AMPLITUDE/SLIGHTLY AMPLIFIED MEAN FLOW TO GRADUALLY TRANSITION
TO A WEST COAST UPR RDG/E-CNTRL NOAM UPR TROF PATTERN NEXT WEEK.
THE MAIN FEATURE OF INTEREST WL BE THE PROGRESSIVE EWD MOVEMENT OF
A LONGWAVE TROF ACROSS THE CNTRL CONUS EARLY NEXT WEEK. THIS
PATTERN SHIFT TO BRING A SW FLOW ALOFT TO NE WI WHICH TRANSLATES
TO NEAR NORMAL TEMPS...BUT ALSO A WET PATTERN WITH SEVERAL ROUNDS
OF PCPN.
SFC LOW CONTS TO SLOWLY TRACK NE ACROSS MN THU NGT WHILE THE CDFNT
PUSHES INTO WRN WI DURING THE OVRNGT HOURS. PERSISTENT SW WINDS
AHEAD OF THE CDFNT/SHORTWAVE TROF WL CONT TO GET PUMPED INTO WI
WITH INDIVIDUAL MID-LEVEL SHORTWAVES LIFTING NE INTO THE GREAT
LAKES. ENUF SHEAR IS EVIDENT TO SUPPORT ORGANIZED/ROTATING
STORMS...THUS A POTENTIAL OF SEVERE STORMS PERSISTS THU NGT. THE
HIGHEST PROBABILITY OF SEVERE LOOKS TO BE TO OUR WEST NEAR THE
TRACK OF THE SFC LOW...HOWEVER LARGE HAIL AND/OR DAMAGING WINDS
ARE POSSIBLE ACROSS THE ENTIRE FCST AREA. MIN TEMPS TO ACTUALLY
HAVE SUMMER FEEL TO THEM WITH DEW POINTS HOLDING IN THE 50S THRU
THE NGT. LOOK FOR READINGS TO ONLY DROP INTO THE LWR TO MID 50S
AROUND DOOR COUNTY TO THE LWR 60S ACROSS E-CNTRL WI.
THE CDFNT DRIVES THRU CNTRL WI FRI MORNING/ERN WI EARLY TO MID FRI
AFTERNOON AND WL NEED TO CARRY POPS UNTIL THIS FNT CLEARS THE
AREA. EVEN BEHIND THE FNT...CANNOT RULE OUT ADDITIONAL SHWR
ACTIVITY AS THE SHORTWAVE TROF/EMBEDDED SHORTWAVE MOVE THRU WI.
HAVE CONTINUED THE LOW-END POPS ACROSS THE ENTIRE FCST AREA THRU
THE AFTERNOON HOURS. WARMEST TEMPS ON FRI TO BE OVER ERN WI PRIOR
TO THE COLD FRONTAL PASSAGE WITH READINGS IN THE UPR 60S.
WEAKENING SHORTWAVE TROF IS FCST TO LIFT NE INTO ONTARIO FRI NGT...
BUT MAY STILL BE CLOSE ENUF TO NE WI TO WARRANT A SMALL POP OVER
NRN SECTIONS OF THE FCST AREA FRI EVENING. OTHERWISE...A WEAK RDG
OF HI PRES WL BUILD TOWARD THE WRN GREAT LAKES LATER FRI NGT AND
BRING CLEARING SKIES AND COOLER CONDITIONS TO THE REGION. MIN
TEMPS TO RANGE FROM THE UPR 30S TO LWR 40S NORTH TO THE LWR TO MID
40S SOUTH. THIS SFC RDG QUICKLY MOVES ACROSS WI ON SAT WITH CLOUDS
ALREADY BEGINNING TO INCREASE AHEAD OF A SHORTWAVE TROF PUSHING
TOWARD THE UPR MS VALLEY. HAVE KEPT ANY PCPN OUT OF THE FCST AREA
FOR NOW AND KEPT MAX TEMPS MAINLY IN THE 65-70 DEG RANGE (COOLER
NEAR LAKE MI).
UNSETTLED WEATHER EXPECTED FOR THE FIRST HALF OF NEXT WEEK AS AN
UPR TROF SLOWLY WORKS ACROSS THE CNTRL CONUS. SW FLOW ALOFT WL
BRING GULF MOISTURE INTO THE WRN GREAT LAKES WITH CHC POPS
NECESSARY FROM SAT NGT THRU MON NGT. THE PASSAGE OF A CDFNT MON
NGT FOLLOWED BY A DRY SLOT ON TUE COULD BRING A BREAK IN THE PCPN
BEFORE THE UPR TROF ARRIVES AND BRINGS CHC POPS BACK INTO THE
FCST. TEMPS WL COOL A BIT EARLY NEXT WEEK WITH READINGS
SLIGHTLY BELOW NORMAL.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1150 AM CDT WED MAY 7 2014
A STRONG WARM FRONT WILL BE LIFTING NORTHWARD ACROSS THE WESTERN
GREAT LAKES AND INTO CENTRAL WISCONSIN BY THE END OF THE TAF
PERIOD. NORTH OF THE WARM FRONT...PERIODS OF SHOWERS AND
THUNDERSTORMS ARE LIKELY...BUT TIMING THESE PERIODS REMAINS VERY
DIFFICULT. THE ROUND MOVING ACROSS NORTHEAST WISCONSIN CURRENTLY
WILL EXIT OVER THE NEXT HOUR OR TWO...THEN COULD SEE A SEVERAL HOUR
BREAK INTO EARLY THIS EVENING. TOUGH TO RULE OUT A POP UP
STORM...BUT COVERAGE IS EXPECTED TO BE ISOLATED UNTIL THE EVENING.
THEN THE FOCUS WILL LOOK TOWARD FAR NORTHERN WISCONSIN TONIGHT...BUT
STORMS COULD TURN SOUTHEAST INTO CENTRAL PARTS OF THE STATE TOO.
REDEVELOPMENT OF THUNDERSTORMS IS POSSIBLE BY MID TO LATE EVENING.
ANOTHER ROUND OF STORMS COULD ALSO ARRIVE TOMORROW MORNING. WITH
THE APPROACHING WARM FRONT...EXPECT CIGS AND VSBYS TO FALL TONIGHT
INTO THURSDAY MORNING.
&&
.MARINE...
ISSUED AT 253 PM CDT WED MAY 7 2014
FOG IS POSSIBLE LATE TONIGHT INTO TOMORROW AS WARM AND HUMID AIR
INVADES FROM THE SOUTH.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......MPC
MARINE.........MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1245 PM CDT WED MAY 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 425 AM CDT WED MAY 7 2014
AT 3 AM...WATCHING 2 AREAS OF CONVECTION. THE FIRST IS LOCATED
OVER EAST CENTRAL WISCONSIN. MEANWHILE THE OTHER ONE IS LOCATED
BETWEEN SIOUX FALLS SOUTH DAKOTA AND FAIRMONT MINNESOTA. BOTH OF
THESE ARE LOCATED ON THE EASTERN EDGE STRONG 700 MB MOISTURE
CONVERGENT AREA. IN ADDITION...THEY ARE LOCATED ONE THE NORTHERN
PERIPHERY OF 1000 J/KG MOST UNSTABLE CAPE. THE ARW...NMM...HOP WRF
AND SPC WRF SUGGEST THAT THE LATTER AREA OF CONVECTION WILL MOVE
EAST ALONG THE INTERSTATE 90 CORRIDOR THIS MORNING. EARLIER IN THE
NIGHT THE HRRR SUGGESTED A SIMILAR SCENARIO...BUT WITH ITS LATEST
RUN IT HAS BACKED AWAY FROM THIS SOLUTION. HOWEVER THIS SCENARIO
DOES NOT MAKE A LOT OF SENSE...SO BACKED AWAY FROM FOLLOWING IT.
TRENDED THE PRECIPITATION FORECAST FOR TODAY TOWARD A BLEND OF
ARW...NMM...HOP WRF AND SPC WRF. HOWEVER I AM A BIT CONCERNED
THAT AS IT MOVES EAST THAT THE NOCTURNAL JET WILL WEAKEN AND THAT
THE CONVECTION COULD DISSIPATE BEFORE IT GETS INTO OUR AREA.
IF THE CONVECTION DOES HAPPEN TO GET INTO OUR AREA...THE SPC RAP
SUGGESTS THAT EFFECTIVE SHEAR WILL INCREASE OVER 40 KNOTS THROUGH
07.14Z. THIS COULD RESULT IN THE DEVELOPMEMT OF SOME ELEVATED
SUPER CELLS. WE WILL HAVE TO MONITOR THIS OVER THE NEXT COUPLE OF
HOURS.
FOR LATER THIS MORNING AND AFTERNOON...MANY OF THE MESO MODELS AND
AND NAM SUGGEST THAT THE AREA WILL REMAIN DRY. THIS IS A RESULT OF
AN ELEVATED MIXED LAYER BEING BROUGHT ISENTROPICALLY OFF OF THE
SOUTHERN PLAINS. THIS LAYER FORMS A STRONG 800 TO 600 MB CAP
ACROSS THE FORECAST AREA. MEANWHILE THE GFS CONTINUES TO TRY AND
DEVELOP STRATIFORM PRECIPITATION BELOW THE CAP. THIS LOOKS VERY
UNLIKELY BECAUSE ITS SATURATED THE AIR MASS BELOW 800 MB TOO MUCH.
DUE TO THIS...STAYED WITH A DRY FORECAST FOR THE TIME PERIOD.
TONIGHT...MANY OF DETERMINISTIC RUNS ARE GENERATING PRECIPITATION
ACROSS MUCH OF THE FORECAST AREA. HOWEVER BUFKIT SOUNDINGS
CONTINUE TO SHOW A FAIRLY STRONG CAP ALONG AND SOUTH OF INTERSTATE
94. THIS IS GOOD AGREEMENT WITH WHAT SHOWS UP IN THE ARW AND SPC
WRF. DUE TO THIS...WENT WITH MUCH LOWER POPS THAN WHAT NORMALLY
WOULD BE EXPECTED SOUTH OF INTERSTATE 94. IF THUNDERSTORMS DID
DEVELOP...IT LOOKS TO BE SO HIGH /BASES OF 2 TO 3 KM/ THAT YOUR
SHEAR IS GREATLY DECREASED TO LESS 25 KNOTS...SO THERE WILL NOT BE
SUPERCELLS. HOWEVER THE CAPE PROFILE IS MUCH FATTER THAN THIS
MORNING AND THIS COULD POTENTIALLY RESULT IN SOME LARGE HAIL.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 425 AM CDT WED MAY 7 2014
ON THURSDAY AND THURSDAY NIGHT...THE 07.00Z MODELS CONTINUE TO
SHOW THAT A PLUME OF SUBTROPICAL MOISTURE WILL SURGE NORTHWARD
AHEAD OF THE LONG WAVE TROUGH. EMBEDDED WAVES IN THIS FLOW WILL
RESULT IN SHOWERS AND THUNDERSTORMS WHICH WILL USE UP MUCH OF THE
CAPE PRIOR TO THE ARRIVAL OF A MUCH MORE FAVORABLE SHEAR PROFILE.
DUE TO THIS...STILL THINKING THAT THE BEST SEVERE WEATHER THREAT
WILL REMAIN WEST OF INTERSTATE 35. WITH THIS PLUME NOT ARRIVING
UNTIL MID MORNING...LOWERED THE PRECIPITATION PROBABILITIES
BETWEEN 08.12Z AND 08.15Z.
FROM SATURDAY NIGHT THROUGH TUESDAY...A SERIES OF SHORT WAVE
TROUGHS WILL EJECTED OUT OF THE LONG WAVE OVER THE WESTERN UNITED
STATES. THIS WILL BRING ROUND OF SHOWERS AND THUNDERSTORMS INTO
THE AREA. WITH STILL SOME TIMING DIFFERENCES AND SUBTLE
DIFFERENCES IN THE MODELS...STAYED WITH THE MODEL CONSENSUS.
TOWARD THE MIDDLE OF NEXT WEEK...IT LOOKS LIKE THERE WILL BE A
PATTERN SHIFT AS THE UPPER LEVEL FLOW BECOMES NORTHWEST AND WEST
ACROSS THE EASTERN UNITED STATES. LOOKS LIKE HIGHS MAY RANGE FROM
THE UPPER 40S TO MID 50S...AND LOWS WILL RANGE FROM THE MID 30S TO
MID 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1245 PM CDT WED MAY 7 2014
IN THE WAKE OF MORNING STORMS...COOL STABLE EASTERLY FLOW HAS
ANCHORED THE WARM FRONT WELL TO THE SOUTH ACROSS CENTRAL IOWA. IN
THE PAST COUPLE HOURS...THERE HAS BEEN A SLOW PUSH TO THE NORTH
BUT NOT EXPECTING THE FRONT TO MAKE IT TO THE TAF SITES UNTIL THE
SURFACE LOW BEGINS TO LIFT MORE TO THE NORTH THIS EVENING. FOR
THE OVERNIGHT PERIOD...SOME INDICATIONS THAT STORMS COULD FIRE UP
ACROSS SOUTHWEST MINNESOTA INTO CENTRAL MINNESOTA. UNCERTAINTY
REMAINS WHETHER KRST WILL BE IMPACTED...BUT FOR NOW INCLUDED A
VCTS GROUP. THIS ACTIVITY SHOULD LIFT AWAY FROM THE AREA BY
SUNRISE. AFTER 12Z THURSDAY...INCREASING MOISTURE AND LIFT
ASSOCIATED WITH THE STRONGER SURFACE LOW AND COLD FRONT TO THE
WEST WILL LEAD TO WIDESPREAD SHOWERS AND
THUNDERSTORMS...ESPECIALLY CLOSER TO 18Z. THIS IS WHEN THE MOST
IMPACTS TO THE TERMINALS COULD BE EXPERIENCED.
&&
.HYDROLOGY...
ISSUED AT 425 AM CDT WED MAY 7 2014
FLOODING CONTINUES ALONG THE MAIN STEM OF THE MISSISSIPPI
RIVER...WITH LOCATIONS CRESTING FROM NORTH MCGREGOR. SHOWERS AND
THUNDERSTORMS ON THURSDAY AND THURSDAY NIGHT WILL PRODUCE ANYWHERE
FROM A HALF INCH TO ONE INCH. THIS WILL LIKELY SLOW THE FALL FOR
LOCATIONS NORTH OF MCGREGOR...AND MAY INCREASE CRESTS SLIGHTLY
SOUTH OF MCGREGOR.
CHECK OUT THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM....BOYNE
AVIATION.....ZT
HYDROLOGY....BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
655 AM CDT WED MAY 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 425 AM CDT WED MAY 7 2014
AT 3 AM...WATCHING 2 AREAS OF CONVECTION. THE FIRST IS LOCATED
OVER EAST CENTRAL WISCONSIN. MEANWHILE THE OTHER ONE IS LOCATED
BETWEEN SIOUX FALLS SOUTH DAKOTA AND FAIRMONT MINNESOTA. BOTH OF
THESE ARE LOCATED ON THE EASTERN EDGE STRONG 700 MB MOISTURE
CONVERGENT AREA. IN ADDITION...THEY ARE LOCATED ONE THE NORTHERN
PERIPHERY OF 1000 J/KG MOST UNSTABLE CAPE. THE ARW...NMM...HOP WRF
AND SPC WRF SUGGEST THAT THE LATTER AREA OF CONVECTION WILL MOVE
EAST ALONG THE INTERSTATE 90 CORRIDOR THIS MORNING. EARLIER IN THE
NIGHT THE HRRR SUGGESTED A SIMILAR SCENARIO...BUT WITH ITS LATEST
RUN IT HAS BACKED AWAY FROM THIS SOLUTION. HOWEVER THIS SCENARIO
DOES NOT MAKE A LOT OF SENSE...SO BACKED AWAY FROM FOLLOWING IT.
TRENDED THE PRECIPITATION FORECAST FOR TODAY TOWARD A BLEND OF
ARW...NMM...HOP WRF AND SPC WRF. HOWEVER I AM A BIT CONCERNED
THAT AS IT MOVES EAST THAT THE NOCTURNAL JET WILL WEAKEN AND THAT
THE CONVECTION COULD DISSIPATE BEFORE IT GETS INTO OUR AREA.
IF THE CONVECTION DOES HAPPEN TO GET INTO OUR AREA...THE SPC RAP
SUGGESTS THAT EFFECTIVE SHEAR WILL INCREASE OVER 40 KNOTS THROUGH
07.14Z. THIS COULD RESULT IN THE DEVELOPMEMT OF SOME ELEVATED
SUPER CELLS. WE WILL HAVE TO MONITOR THIS OVER THE NEXT COUPLE OF
HOURS.
FOR LATER THIS MORNING AND AFTERNOON...MANY OF THE MESO MODELS AND
AND NAM SUGGEST THAT THE AREA WILL REMAIN DRY. THIS IS A RESULT OF
AN ELEVATED MIXED LAYER BEING BROUGHT ISENTROPICALLY OFF OF THE
SOUTHERN PLAINS. THIS LAYER FORMS A STRONG 800 TO 600 MB CAP
ACROSS THE FORECAST AREA. MEANWHILE THE GFS CONTINUES TO TRY AND
DEVELOP STRATIFORM PRECIPITATION BELOW THE CAP. THIS LOOKS VERY
UNLIKELY BECAUSE ITS SATURATED THE AIR MASS BELOW 800 MB TOO MUCH.
DUE TO THIS...STAYED WITH A DRY FORECAST FOR THE TIME PERIOD.
TONIGHT...MANY OF DETERMINISTIC RUNS ARE GENERATING PRECIPITATION
ACROSS MUCH OF THE FORECAST AREA. HOWEVER BUFKIT SOUNDINGS
CONTINUE TO SHOW A FAIRLY STRONG CAP ALONG AND SOUTH OF INTERSTATE
94. THIS IS GOOD AGREEMENT WITH WHAT SHOWS UP IN THE ARW AND SPC
WRF. DUE TO THIS...WENT WITH MUCH LOWER POPS THAN WHAT NORMALLY
WOULD BE EXPECTED SOUTH OF INTERSTATE 94. IF THUNDERSTORMS DID
DEVELOP...IT LOOKS TO BE SO HIGH /BASES OF 2 TO 3 KM/ THAT YOUR
SHEAR IS GREATLY DECREASED TO LESS 25 KNOTS...SO THERE WILL NOT BE
SUPERCELLS. HOWEVER THE CAPE PROFILE IS MUCH FATTER THAN THIS
MORNING AND THIS COULD POTENTIALLY RESULT IN SOME LARGE HAIL.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 425 AM CDT WED MAY 7 2014
ON THURSDAY AND THURSDAY NIGHT...THE 07.00Z MODELS CONTINUE TO
SHOW THAT A PLUME OF SUBTROPICAL MOISTURE WILL SURGE NORTHWARD
AHEAD OF THE LONG WAVE TROUGH. EMBEDDED WAVES IN THIS FLOW WILL
RESULT IN SHOWERS AND THUNDERSTORMS WHICH WILL USE UP MUCH OF THE
CAPE PRIOR TO THE ARRIVAL OF A MUCH MORE FAVORABLE SHEAR PROFILE.
DUE TO THIS...STILL THINKING THAT THE BEST SEVERE WEATHER THREAT
WILL REMAIN WEST OF INTERSTATE 35. WITH THIS PLUME NOT ARRIVING
UNTIL MID MORNING...LOWERED THE PRECIPITATION PROBABILITIES
BETWEEN 08.12Z AND 08.15Z.
FROM SATURDAY NIGHT THROUGH TUESDAY...A SERIES OF SHORT WAVE
TROUGHS WILL EJECTED OUT OF THE LONG WAVE OVER THE WESTERN UNITED
STATES. THIS WILL BRING ROUND OF SHOWERS AND THUNDERSTORMS INTO
THE AREA. WITH STILL SOME TIMING DIFFERENCES AND SUBTLE
DIFFERENCES IN THE MODELS...STAYED WITH THE MODEL CONSENSUS.
TOWARD THE MIDDLE OF NEXT WEEK...IT LOOKS LIKE THERE WILL BE A
PATTERN SHIFT AS THE UPPER LEVEL FLOW BECOMES NORTHWEST AND WEST
ACROSS THE EASTERN UNITED STATES. LOOKS LIKE HIGHS MAY RANGE FROM
THE UPPER 40S TO MID 50S...AND LOWS WILL RANGE FROM THE MID 30S TO
MID 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 655 AM CDT WED MAY 7 2014
THROUGH 07.1330Z STRONG TO SEVERE THUNDERSTORMS WILL AFFECT KRST.
THE MAIN THREAT WITH THESE THUNDERSTORMS WILL BE LARGE HAIL.
WITH THE WEAKENING OF THE LOW LEVEL JET...EXPECT THE SHOWERS AND
THUNDERSTORMS ALONG AND NORTH OF INTERSTATE 90 TO DISSIPATE
BY 07.15Z. WHILE BOTH THE GFS AND NAM SOUNDINGS SUGGEST MVFR
CEILINGS THROUGH TONIGHT. THE RAP SOUNDINGS SHOW THAT CEILINGS
WILL REMAIN VFR. LOOKING AT CEILINGS AROUND THE REGION...THE RAP
IS VERIFYING THE BEST...SO TRENDED THE TAFS THAT WAY.
FOR TONIGHT...THE MESO MODELS SUGGEST THAT ADDITIONAL SHOWERS AND
THUNDERSTORMS WILL FIRE WELL NORTH OF THE TAF SITES...THUS...
WENT DRY WITH VFR CEILINGS.
&&
.HYDROLOGY...
ISSUED AT 425 AM CDT WED MAY 7 2014
FLOODING CONTINUES ALONG THE MAIN STEM OF THE MISSISSIPPI
RIVER...WITH LOCATIONS CRESTING FROM NORTH MCGREGOR. SHOWERS AND
THUNDERSTORMS ON THURSDAY AND THURSDAY NIGHT WILL PRODUCE ANYWHERE
FROM A HALF INCH TO ONE INCH. THIS WILL LIKELY SLOW THE FALL FOR
LOCATIONS NORTH OF MCGREGOR...AND MAY INCREASE CRESTS SLIGHTLY
SOUTH OF MCGREGOR.
CHECK OUT THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...BOYNE
HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
425 AM CDT WED MAY 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 425 AM CDT WED MAY 7 2014
AT 3 AM...WATCHING 2 AREAS OF CONVECTION. THE FIRST IS LOCATED
OVER EAST CENTRAL WISCONSIN. MEANWHILE THE OTHER ONE IS LOCATED
BETWEEN SIOUX FALLS SOUTH DAKOTA AND FAIRMONT MINNESOTA. BOTH OF
THESE ARE LOCATED ON THE EASTERN EDGE STRONG 700 MB MOISTURE
CONVERGENT AREA. IN ADDITION...THEY ARE LOCATED ONE THE NORTHERN
PERIPHERY OF 1000 J/KG MOST UNSTABLE CAPE. THE ARW...NMM...HOP WRF
AND SPC WRF SUGGEST THAT THE LATTER AREA OF CONVECTION WILL MOVE
EAST ALONG THE INTERSTATE 90 CORRIDOR THIS MORNING. EARLIER IN THE
NIGHT THE HRRR SUGGESTED A SIMILAR SCENARIO...BUT WITH ITS LATEST
RUN IT HAS BACKED AWAY FROM THIS SOLUTION. HOWEVER THIS SCENARIO
DOES NOT MAKE A LOT OF SENSE...SO BACKED AWAY FROM FOLLOWING IT.
TRENDED THE PRECIPITATION FORECAST FOR TODAY TOWARD A BLEND OF
ARW...NMM...HOP WRF AND SPC WRF. HOWEVER I AM A BIT CONCERNED
THAT AS IT MOVES EAST THAT THE NOCTURNAL JET WILL WEAKEN AND THAT
THE CONVECTION COULD DISSIPATE BEFORE IT GETS INTO OUR AREA.
IF THE CONVECTION DOES HAPPEN TO GET INTO OUR AREA...THE SPC RAP
SUGGESTS THAT EFFECTIVE SHEAR WILL INCREASE OVER 40 KNOTS THROUGH
07.14Z. THIS COULD RESULT IN THE DEVELOPMEMT OF SOME ELEVATED
SUPER CELLS. WE WILL HAVE TO MONITOR THIS OVER THE NEXT COUPLE OF
HOURS.
FOR LATER THIS MORNING AND AFTERNOON...MANY OF THE MESO MODELS AND
AND NAM SUGGEST THAT THE AREA WILL REMAIN DRY. THIS IS A RESULT OF
AN ELEVATED MIXED LAYER BEING BROUGHT ISENTROPICALLY OFF OF THE
SOUTHERN PLAINS. THIS LAYER FORMS A STRONG 800 TO 600 MB CAP
ACROSS THE FORECAST AREA. MEANWHILE THE GFS CONTINUES TO TRY AND
DEVELOP STRATIFORM PRECIPITATION BELOW THE CAP. THIS LOOKS VERY
UNLIKELY BECAUSE ITS SATURATED THE AIR MASS BELOW 800 MB TOO MUCH.
DUE TO THIS...STAYED WITH A DRY FORECAST FOR THE TIME PERIOD.
TONIGHT...MANY OF DETERMINISTIC RUNS ARE GENERATING PRECIPITATION
ACROSS MUCH OF THE FORECAST AREA. HOWEVER BUFKIT SOUNDINGS
CONTINUE TO SHOW A FAIRLY STRONG CAP ALONG AND SOUTH OF INTERSTATE
94. THIS IS GOOD AGREEMENT WITH WHAT SHOWS UP IN THE ARW AND SPC
WRF. DUE TO THIS...WENT WITH MUCH LOWER POPS THAN WHAT NORMALLY
WOULD BE EXPECTED SOUTH OF INTERSTATE 94. IF THUNDERSTORMS DID
DEVELOP...IT LOOKS TO BE SO HIGH /BASES OF 2 TO 3 KM/ THAT YOUR
SHEAR IS GREATLY DECREASED TO LESS 25 KNOTS...SO THERE WILL NOT BE
SUPERCELLS. HOWEVER THE CAPE PROFILE IS MUCH FATTER THAN THIS
MORNING AND THIS COULD POTENTIALLY RESULT IN SOME LARGE HAIL.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 425 AM CDT WED MAY 7 2014
ON THURSDAY AND THURSDAY NIGHT...THE 07.00Z MODELS CONTINUE TO
SHOW THAT A PLUME OF SUBTROPICAL MOISTURE WILL SURGE NORTHWARD
AHEAD OF THE LONG WAVE TROUGH. EMBEDDED WAVES IN THIS FLOW WILL
RESULT IN SHOWERS AND THUNDERSTORMS WHICH WILL USE UP MUCH OF THE
CAPE PRIOR TO THE ARRIVAL OF A MUCH MORE FAVORABLE SHEAR PROFILE.
DUE TO THIS...STILL THINKING THAT THE BEST SEVERE WEATHER THREAT
WILL REMAIN WEST OF INTERSTATE 35. WITH THIS PLUME NOT ARRIVING
UNTIL MID MORNING...LOWERED THE PRECIPITATION PROBABILITIES
BETWEEN 08.12Z AND 08.15Z.
FROM SATURDAY NIGHT THROUGH TUESDAY...A SERIES OF SHORT WAVE
TROUGHS WILL EJECTED OUT OF THE LONG WAVE OVER THE WESTERN UNITED
STATES. THIS WILL BRING ROUND OF SHOWERS AND THUNDERSTORMS INTO
THE AREA. WITH STILL SOME TIMING DIFFERENCES AND SUBTLE
DIFFERENCES IN THE MODELS...STAYED WITH THE MODEL CONSENSUS.
TOWARD THE MIDDLE OF NEXT WEEK...IT LOOKS LIKE THERE WILL BE A
PATTERN SHIFT AS THE UPPER LEVEL FLOW BECOMES NORTHWEST AND WEST
ACROSS THE EASTERN UNITED STATES. LOOKS LIKE HIGHS MAY RANGE FROM
THE UPPER 40S TO MID 50S...AND LOWS WILL RANGE FROM THE MID 30S TO
MID 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1141 PM CDT TUE MAY 6 2014
SAW ONE BAND OF SHRA/TS DEVELOP EAST OF KLSE EARLIER THIS
EVENING...BUT THAT HAS SINCE MOVED INTO EAST CENTRAL WI. FAIRLY
QUIET AT THE MOMENT UPSTREAM PER RADAR MOSAIC AND SURFACE
OBSERVATION IN ADVANCE OF A WARM FRONT LIFTING NORTHWARD OUT OF
THE CENTRAL PLAINS. MODELS PUSHING THE WARM FRONTAL BOUNDARY INTO
THE AREA WEDNESDAY...TO ALONG I-94 BY WEDNESDAY EVENING. A FEW OF
THE MODELS STILL DEVELOPING SHRA/TS ACTIVITY OVERNIGHT WITH SURGE
OF MOISTURE/LIFT OUT AHEAD OF THE FRONT...BUT STILL A FAIR AMOUNT
OF UNCERTAINTY THOUGH BETWEEN THE MODELS ON COVERAGE OF THIS
SHRA/TS ACTIVITY AND WHETHER KLSE/KRST WILL BE AFFECTED. WILL
MAINTAIN VCSH/VCTS IN THE TAFS IN THE 06-13Z TIMEFRAME.
OTHERWISE...VFR CONDITIONS EXPECTED. BACKED OFF ON MVFR
STRATOCUMULUS IN THE MORNING DUE TO LACK OF WIDESPREAD
PRECIPITATION AND BOUNDARY LAYER MOISTENING. PLAN ON VFR
CONDITIONS THROUGH THE REST OF THE PERIOD AS WELL WITH ANY
CONVECTION ASSOCIATED WITH THE WARM FRONT EXPECTED TO REMAIN NORTH
OF THE KRST/KLSE TAF SITES.
&&
.HYDROLOGY...
ISSUED AT 425 AM CDT WED MAY 7 2014
FLOODING CONTINUES ALONG THE MAIN STEM OF THE MISSISSIPPI
RIVER...WITH LOCATIONS CRESTING FROM NORTH MCGREGOR. SHOWERS AND
THUNDERSTORMS ON THURSDAY AND THURSDAY NIGHT WILL PRODUCE ANYWHERE
FROM A HALF INCH TO ONE INCH. THIS WILL LIKELY SLOW THE FALL FOR
LOCATIONS NORTH OF MCGREGOR...AND MAY INCREASE CRESTS SLIGHTLY
SOUTH OF MCGREGOR.
CHECK OUT THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...DAS
HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
858 PM MDT THU MAY 8 2014
.UPDATE...
ISSUED AT 833 PM MDT THU MAY 8 2014
LATEST RADAR LOOP WAS SHOWING SHOWERS CONTINUING TO FLARE UP
ACROSS EXTREME SOUTHEAST WYOMING MAINLY ALONG AND EAST OF THE
LARAMIE RANGE DUE TO A COOL DOME ALOFT AND UPSLOPE FLOW PROMOTING
THE INSTABILITY. THE MODELS ARE CONTINUING TO ADVERTISE THIS DOME
OF COOL AIR SHIFTING EAST OVERNIGHT WHICH SHOULD ALLOW FOR MORE
SUBSIDENCE TO MOVE INTO SOUTHEAST WYOMING. HOWEVER...I AM A LITTLE
LEARY ABOUT YANKING THE POPS COMPLETELY UNTIL 3AM...SINCE WE DO
HAVE SOMEWHAT OF AN UPSLOPE COMPONENT. THE OTHER CONCERN WE HAVE
TONIGHT IS THE FOG POTENTIAL WHERE THE SNOWFALL TOOK PLACE LAST
NIGHT. SNOW/CLOUD DISCRIMINATOR PRODUCT FROM CIRA IS SHOWING THE
BULK OF THE SNOW OCCURRED IN THE NORTHERN PANHANDLE WHICH LOOKS
TO BE THE MOST FAVORABLE REGION FOR FOG DEVELOPING OVERNIGHT. THIS
AREA IS ALSO BEGIN TO CLEAR OUT WITH SOME PATCHY FOG BEGINNING TO
SHOW UP IN DAWES AND BOX BUTTE COUNTIES. HRRR ALSO SHOWS GOOD
INDICATIONS OF THIS FOG PERSISTING THROUGH THE NIGHT. WE MAY ALSO
HAVE TO WATCH THIS AREA FOR POTENTIAL FOG ADVISORY.
OTHERWISE...CURRENT FORECAST APPEARS TO BE ON TRACK.
UPDATE ISSUED AT 415 PM MDT THU MAY 8 2014
SENDING OUT A QUICK UPDATE TO INCREASE PRECIPITATION CHANCES
ACROSS ALBANY...LARAMIE AND KIMBALL COUNTIES AS A BATCH OF RAIN
AND EMBEDDED THUNDER MOVES EAST THROUGH THAT REGION. THE BULK OF
THE CONVECTION SHOULD END AFTER SUNSET.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 330 PM MDT THU MAY 8 2014
SNOW HAS COME TO AN END ACROSS THE NORTHERN NE PANHANDLE THIS AFTN
AS AN INTENSE SFC LOW AND ASSOCIATED MID LEVEL TROWAL HAVE EXITED THE
AREA TO THE NORTHEAST. ONLY CONCERN IN THE NEAR TERM WILL BE THE
POTENTIAL FOR CONVECTIVE ACTIVITY THROUGH THIS EVE. CLEARING SKIES ON THE
BACK SIDE OF THE SYSTEM HAVE ALLOWED TEMPS TO WARM NICELY...INTO THE
MIDDLE TO UPPER 40S ACROSS MUCH OF SOUTHEAST WY. MID LEVELS ARE QUITE
COLD WITH LAPS SOUNDINGS SHOWING H5 TEMPS TO -20C...SO A GREAT SETUP
FOR INSTABILITY RAIN SHOWERS. LATEST RADAR LOOP SHOWS THIS ACTIVITY
CONFINED TO THE I80 CORRIDOR...AND BELIEVE THIS TREND WILL CONTINUE
THROUGH THE EARLY EVE AS MESOSCALE MODELS SHOW LIFTED INDICES AROUND
ZERO HERE. WE HAVE SEEN SOME LIGHTNING STRIKES ALONG THE CO BORDER
IN THE PAST FEW HOURS...BUT MODEST CONVECTIVE INSTABILITY PROFILES
SUGGEST MOST OF THIS ACTIVITY WILL BE OF THE SHOWER VARIETY. LARGE
SCALE SUBSIDENCE WILL BUILD INTO THE AREA BY LATE EVE BENEATH WEAK
SHORTWAVE RIDGING...ENDING THE THREAT FOR SHOWERS AND STORMS. NEXT
CHANCE FOR CONVECTION WILL BE FRI AFTN AHEAD OF THE NEXT WEAK MID LEVEL
SHORTWAVE EMBEDDED WITHIN ZONAL FLOW ALOFT. WENT AHEAD AND ADDED ISO
THUNDER TO THE GRIDS AS THE LATEST GFS IS SHOWING 500 TO 750 J/KG OF
SBCAPE. NAM BUFKIT SOUNDINGS SHOW SOME WEAK ELEVATED INSTABILITY AS
WELL. NO CONCERNS FOR SEVERE WEATHER THOUGH. DESPITE SOME HIGH LEVEL
CLOUD COVER LIKELY MOVING OVERHEAD WITH INCREASING 700-300 MILLIBAR
MOISTURE...DOWNSLOPE WARMING SHOULD AID IN WIDESPREAD 60S FOR HIGHS
EAST OF THE LARAMIE RANGE. MOST OF THE SNOW IN THE PANHANDLE SHOULD
BE MELTED BY THEN...SO EXPECT A MINIMAL IMPACT TO TEMPS.
ATTENTION THEN SHIFTS TO THE POTENTIAL FOR YET ANOTHER MAJOR STORM
FOR THE WEEKEND. MODELS ARE IN GREAT AGREEMENT SHOWING A VIGOROUS
UPPER-LEVEL TROUGH DIGGING INTO THE GREAT BASIN ON SAT. MOIST SOUTH
WEST FLOW ALOFT AND A FEW DISTURBANCES EMANATING FROM THE PARENT
TROUGH SUGGESTS ANOTHER GOOD CHANCE FOR SHOWERS AND STORMS...THOUGH
WESTERLY LOW LEVEL FLOW SUGGESTS THE BULK OF THIS ACTIVITY WILL BE
ALONG AND WEST OF THE LARAMIE RANGE. LIMITED MOISTURE SHOULD KEEP
SEVERE WEATHER AT BAY THIS TIME AROUND...THOUGH SHEAR PROFILES
WILL BE RATHER STRONG. GFS...NAM...AND ECMWF ALL SHOW A STRONG SFC
COLD FRONT BLASTING SOUTH ACROSS THE CWA LATE SAT NIGHT. NORTH TO
NORTH EAST SFC UPSLOPE FLOW AND LARGE SCALE VERTICAL ASCENT WILL
ALMOST CERTAINLY FAVOR PCPN DEVELOPMENT...BUT THE BIG QUESTION NOW
IS EXACTLY WHERE. THE GFS IS STILL THE OUTLIER WITH HEAVY PCPN
BANDING FROM NORTH CENTRAL CO INTO THE SOUTHERN PANHANDLE...WHILE
THE ECMWF AND GEM ARE MUCH FURTHER NORTH WITH THE FRONTOGENESIS
BAND AND WOULD AFFECT A LARGER PART OF OUR CWA. REGARDLESS...H7
TEMPS FALL TO BETWEEN -8C AND -12C IN THE POST FROPA AIR MASS WITH
1000-500 MB THICKNESSES RANGING FROM 540 TO 549 DM FROM NORTHWEST
TO SOUTHEAST AT 12Z SUN. THIS WOULD SUPPORT SNOW... AND A LOT OF
IT IF MODELED QPF VALUES ARE ANYTHING CLOSE TO WHAT ACTUALLY
TRANSPIRES. IT IS A LITTLE UNSETTLING THAT THE ECMWF HAS BEEN
CONSISTENT OVER THE LAST COUPLE OF RUNS WITH THE PLACEMENT OF THE
HEAVIEST SNOW. IT WAS ALSO THE FIRST TO LOCK ON TO THIS PARTICULAR
STORM EVOLUTION. IT IS MUCH TOO EARLY FOR ANY SORT OF
HEADLINE...BUT CONFIDENCE IS HIGH THAT A PORTION OF OUR CWA WILL
SEE SIGNIFICANT WINTER WEATHER. WENT AHEAD AND ISSUED A SPECIAL
WEATHER STATEMENT HIGHLIGHTING THE POTENTIAL STORM FOR PUBLIC
AWARENESS.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM MDT THU MAY 8 2014
FORECAST CHALLENGES EARLY IN THE EXTENDED PERIOD WILL FOCUS ON THE
SPRING STORM SYSTEM MOVING ACROSS THE CENTRAL ROCKIES AND PLAINS.
THERE ARE TIMING...STRENGTH AND POSITION DIFFERENCES WITH EMERGENCE
OF THE UPPER LOW FROM THE CENTRAL GREAT BASIN SUNDAY. THE GFS IS
TRENDING SLIGHTLY FASTER AND NORTH OF THE ECMWF. AT 12Z SUNDAY...GFS
PROGS THE 554DM LOW OVER EAST CENTRAL UT...WHILE THE ECMWF/S 550DM
LOW IS SITUATED IN SOUTHWEST UT. THE PRIMARY SURFACE LOW SHOWN BY
THE GFS AT THE SAME TIME IS OVER FAR SOUTHWEST CO AND THE ECMWF/S
LOW IS ALONG THE AZ/UT BORDER. BY 00Z MONDAY...GFS 559DM LOW IS
OVER FAR WESTERN CO AND THE ECWMF 554DM LOW IS OVER SOUTH CENTRAL
UT. THE SURFACE LOW REDEVELOPS AND INTENSIFIES OVER THE NORTHERN
TX PANHANDLE IN THE GFS...AND SOUTHWEST CORNER OF KS IN THE ECMWF.
THE 1000-500MB THICKNESS GRADIENT RAPIDLY TIGHTENS AND INTENSE
LOW/MID LEVEL ASCENT DEVELOPS. COLD AIR AT LOW LEVELS WILL BE
ADVECTED SOUTH INTO THE STORM SYSTEM ALONG THE EASTERN SLOPES OF
THE ROCKIES...LOWERING SNOW LEVELS SIGNIFICANTLY. PLENTY OF
MOISTURE WRAPPING INTO THE LOW...MID LEVEL QG FORCING AND LOW
LEVEL UPSLOPE WILL RESULT IN SIGNIFICANT PRECIPITATION....WITH
SNOW LEVELS POSSIBLY DROPPING AS LOW AS 4500 FT. A CONSENSUS OF
THE GFS AND ECMWF QPF FROM 00Z SUNDAY THROUGH 12Z MONDAY INDICATES
BETWEEN 1.5 AND 2.5 INCHES OF LIQUID PRECIPITATION. CONSENSUS MODEL
SNOW ACCUMULATIONS PROJECT BETWEEN 12 AND 20 INCHES FOR THE MOUNTAINS...
4 TO 10 INCHES LOWER ELEVATIONS ALONG AND SOUTH OF I-80...AND 1 TO 4
INCHES NORTH OF I-80. STILL PLENTY OF UNCERTAINTY WITH THIS STORM
AND WILL CONTINUE TO EVALUATE TRENDS AS THE STRENGTH AND TRACK OF
THE STORM SYSTEM CAN CHANGE FROM ONE MODEL RUN TO THE NEXT.
IT WILL BE MUCH COLDER SUNDAY AS 700MB TEMPERATURES FALL TO -5C TO
-10C. HIGH TEMPERATURES SUNDAY WILL RANGE FROM THE 20S MOUNTAINS TO
THE 40S OVER THE PLAINS. THESE TEMPERATURES MAY BE NEED TO BE LOWERED
WITH LATER FORECASTS. GUSTY NORTHEAST WINDS OF 20 TO 30 MPH WILL ADD
TO THE CHILL.
IF YOU BELIEVE THE GFS...SNOW WILL BEGIN TO TAPER OFF FROM WEST
TO EAST MONDAY MORNING. THE ECMWF KEEPS THE UPPER TROUGH AXIS ALONG
THE FRONT RANGE WHICH WOULD PROLONG THE PRECIPITATION INTO MONDAY
NIGHT. NORTHWEST FLOW ALOFT WILL PREVAIL TUESDAY THROUGH THURSDAY.
THERE ARE INDICATIONS THAT IT WILL NOT BE DRY STABLE FLOW AS THERE
WILL BE SOME MINOR DISTURBANCES WHICH MAY GENERATE SHOWERY EPISODES.
TEMPERATURES MODERATE TOWARD SEASONAL NORMALS BY THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY AFTERNOON)
ISSUED AT 653 PM MDT THU MAY 8 2014
RAIN SHOWERS WITH A FEW EMBEDDED TSTORMS REMAIN A THREAT FOR
WESTERN AND SOUTHERN PORTIONS OF WYOMING THIS EVENING THROUGH
ROUGHLY 03Z. AREAS OF FOG/STRATUS LOOK TO DEVELOP MAINLY IN THE
NORTHERN NEBRASKA PANHANDLE AND NORTH PLATTE RIVER VALLEY OVERNIGHT.
IN PARTICULAR...MVFR TO IFR CIGS AND VSBYS ARE EXPECTED AT KCDR
AND KAIA...WITH SOME POTENTIAL TO REACH KBFF. CONDITIONS IN THESE
LOCATIONS WILL IMPROVE SHORTLY AFTER SUNRISE. ELSEWHERE...VFR
CONDITIONS WILL PREVAIL. WINDS WILL DIMINISH TONIGHT...BUT WILL
INCREASE LATE IN THE MORNING AND REMAIN GUSTY THROUGH FRIDAY
AFTERNOON. WEST TO SOUTHWEST WINDS GUSTING 25 TO 35 KTS ARE
EXPECTED ALONG AND WEST OF THE LARAMIE RANGE...WITH 20 TO 25 KTS
FURTHER EAST.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MDT THU MAY 8 2014
NO FIRE WEATHER CONCERNS. MILD CONDITIONS ARE EXPECTED FOR FRIDAY
AND SATURDAY...BUT WINDS AND RELATIVE HUMIDITY VALUES ARE EXPECTED
TO REMAIN WELL OUTSIDE OF CRITICAL THRESHOLDS. ANOTHER SPRING STORM
WILL AFFECT THE AREA SUNDAY AND MONDAY...BRINGING COOLER TEMPERATURES
AND WIDESPREAD RAIN AND SNOW.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...REC
SHORT TERM...HAMMER
LONG TERM...JAMSKI
AVIATION...RJM
FIRE WEATHER...HAMMER
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
631 AM MDT WED MAY 7 2014
.UPDATE...
ISSUED AT 602 AM MDT WED MAY 7 2014
WILL ADD SOME FOG TO THE FORECAST GRIDS THROUGH MID MORNING. FOG
HAS FORMED MAINLY ALONG THE LEADING EDGE OF A COLD FRONT THIS
MORNING...GENERALLY FROM LARAMIE TO CHEYENNE TO KIMBALL. SOME
LOCALLY DENSE FOR IS POSSIBLE. THE FOG SHOULD LIFT INTO A STRATUS
DECK BY MID MORNING.
ALSO OF NOTE IS THE 06Z MODEL RUNS. BOTH THE NAM AND GFS PUSH THE
SURFACE COLD FRONT ABOUT 30 TO 40 MILES FARTHER SOUTH THAN THE 00Z
RUNS. THE IMPLICATIONS OF THIS ARE MANY. FIRST...THIS WILL SHIFT
THE SEVERE THREAT SLIGHTLY SOUTHWARD...AND WILL GREATLY REDUCE THE
THREAT FOR TORNADIC ACTIVITY IN THE CWA THIS AFTERNOON. WILL STILL
HAVE TO KEEP AN EYE ON THE LOCATION OF THE SURFACE FRONT THIS
AFTERNOON...BUT LOOKS LIKE THE MAIN TORNADO THREAT WILL BE JUST
SOUTH OF THE NEBRASKA BORDER. THE OTHER IMPACT WILL BE ON SNOW
AMOUNTS. A DEEPER COLD BOUNDARY LAYER IS MORE FAVORABLE FOR RAIN
CHANGING TO SNOW TONIGHT. IT MAY BE JUST COLD ENOUGH GIVEN HIGH
PRECIPITATION RATES FOR A GOOD DEAL OF SNOW ACCUMULATIONS...WITH
SNOW ADVISORIES AND WINTER STORM WARNINGS A MUCH GREATER
LIKELIHOOD TONIGHT INTO THURSDAY MORNING. MODELS ARE ALSO SLOWER WITH
THE DEPARTURE OF THIS SYSTEM WITH COULD ALSO INCREASE SNOW
ACCUMULATIONS. LATEST OBSERVATIONS ACROSS NORTHEAST WYOMING
SHOWING TEMPERATURES IN THE LOWER TO MIDDLE 30S...SO THE 06Z MODEL
RUNS MAY BE ON TO SOMETHING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 445 AM MDT WED MAY 7 2014
WOW...LOTS OF WEATHER CONCERNS TODAY...FROM RIVER FLOODING TO
FLASH FLOODING...TO SEVERE THUNDERSTORMS WITH TORNADOES POSSIBLE...
TO THE POTENTIAL FOR HEAVY SNOW TONIGHT. THIS MORNING WILL BE
RELATIVELY QUIET WITH SHOWERS DEVELOPING AS AN UPPER LEVEL SYSTEM
APPROACHES AND COULD SEE A FEW THUNDERSTORMS BY LATER THIS
MORNING. THE MAIN CHANCES FOR THUNDERSTORMS WILL HOLD OFF UNTIL
THIS AFTERNOON. THERE IS A HIGH PROBABILITY FOR SOME OF THESE
THUNDERSTORMS TO BECOME SEVERE...MAINLY OVER FAR SOUTHEAST WYOMING
AND INTO NEBRASKA PANHANDLE. OF COURSE ALL THIS IS PREDICATED ON
THE EXACT TRACK OF THE UPPER LEVEL LOW.
AT THIS TIME IT APPEARS THERE WILL BE SUFFICIENT UPPER LEVEL
FORCING AND MID LEVEL INSTABILITY FOR SEVERE THUNDERSTORMS. INTO
THE SOUTHERN NEBRASKA PANHANDLE...MODELS SHOWING MOST UNSTABLE
CAPE VALUES 2000 J/KG ALONG AND JUST NORTH OF A STALLED
FRONTAL BOUNDARY. ALSO LOOKING AT 50 TO 60 KTS OF BULK SHEAR WHICH
IS MORE THAN ENOUGH FOR ROTATING SUPERCELL THUNDERSTORMS. ASSUMING
THE FRONT IS LOCATED NEAR THE INTERSTATE 80 CORRIDOR...SHOULD SEE
STORMS FIRE NEAR THE BOUNDARY AND THEN LIFT NORTHWARD UNDER STRONG
SOUTHERN MIDLEVEL WINDS. NOT 100 PERCENT CONFIDENT ON THE EXACT
LOCATION OF THE FRONT...BUT IT SHOULD BE BETWEEN INTERSTATE 80 AND
THE COLORADO BORDER. THERE IS THE POSSIBILITY FOR TORNADIC ACTIVITY
ALONG THIS FRONTAL BOUNDARY FROM ABOUT MID AFTERNOON INTO EARLY
EVENING. AIR TEMPERATURES WILL BE RATHER COOL...BUT THAT WILL NOT
NECESSARILY PRECLUDE TORNADO DEVELOPMENT. STRONG LOW LEVEL SHEAR
AND LIFTED CONDENSATION LEVELS ONLY A FEW THOUSAND FEET AGL ARE
FAVORABLE FOR TORNADIC DEVELOPMENT. THE TORNADO THREAT WILL BE
CONFINED TO AREAS ALONG AND NEAR THE BOUNDARY...MAINLY BETWEEN
PINE BLUFF TO KIMBALL TO SIDNEY. ALSO WORTH MENTIONING THE THE
POTENTIAL FOR VERY LARGE HAIL. THE STORM PREDICATION CENTER HAS
HATCHED HAIL FOR STONES UP TO 2 INCHES IN DIAMETER. THIS SEEMS VERY
REASONABLE GIVEN MIDLEVEL CAPE VALUES AND SHEAR PARAMETERS. SHOULD
CAPE VALUES END UP BEING MUCH HIGHER...BASEBALL OR LARGER HAIL
WOULD COME INTO PLAY. ANOTHER THING TO CONSIDER IS FREEZING LEVELS
ARE LOW...SO FALLING HAIL WILL NOT SEE MUCH MELTING. FOR FLASH
FLOOD POTENTIAL IN THE SOUTHERN NEBRASKA PANHANDLE LATER TODAY...
SEE THE HYDROLOGY DISCUSSION BELOW.
LATER TONIGHT THE ATTENTION TURNS TO THE POTENTIAL FOR SNOW...AND
POSSIBILITY HEAVY SNOW. CONFIDENCE NOT HIGH WITH THE CURRENT SNOW
FORECAST AS THERE AREA MORE VARIABLES AT PLAY WITH THIS SPRING
STORM SYSTEM. WHERE AND HOW MUCH SNOW FALLS WILL BE LARGELY
DEPENDENT ONLY A FEW DEGREES DIFFERENCE IN ACTUALLY AIR
TEMPERATURES...AND DEPENDENT ON PRECIPITATION RATES. MODELS HAVE
TRENDED SLIGHTLY COLDER...WHICH MAKES THE POTENTIAL FOR HEAVY SNOW
A GREATER POSSIBILITY...EVEN INTO THE PLAINS IN THE NEBRASKA
PANHANDLE. MODELS SHOWING A PERIOD OF MODERATE RAIN ON THE
BACKSIDE OF THE AREA OF LOW PRESSURE. THIS PRECIPITATION COULD
EASILY WETBULB DOWN TO THE POINT WHERE SNOW ACCUMULATES AS RATES
OF AN INCH OR MORE PER HOUR. THE WARM GROUND WILL INITIALLY MELT
MUCH OF THE SNOW...BUT WITH SEVERAL HOURS OF HIGH SNOW
RATES...SOME PLACE CERTAINLY COULD PUSH SNOW ADVISORY LEVELS...AND
NOT DISCOUNTING WARNING CRITERIA BEING REACHED AT A FEW LOCATIONS.
GIVEN LARGE UNCERTAINTY AND WITH THE THREAT FOR SEVERE WEATHER
INTO EARLY THIS EVENING...DID NOT ISSUE ANY HEADLINES. WILL HAVE
TO SEE WHAT WHAT THE 12 MODEL RUNS SHOW...BUT VERY WELL MAY NEED
WINTER WEATHER HEADLINES AT SOME POINT.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 330 AM MDT WED MAY 7 2014
UNSETTLED WEATHER CONTINUES IN THE LONG TERM WITH A PRETTY GOOD
WINTER SYSTEM POSSIBLE SUNDAY INTO MONDAY.
STARTING OFF ON FRIDAY...FAST MOVING SHORTWAVE MOVES THROUGH
NORTHERN PORTIONS OF WYOMING WITH SHOWERS CONTINUING OVER OUR
WESTERN MOUNTAINS. TEMPERATURES LOOK WARM ENOUGH FOR MAINLY RAIN
SHOWERS. WILL NEED TO WATCH THIS FRIDAY AS THE RAIN COULD
EXACERBATE SNOW MELT OVER THE SNOWY AND SIERRA MADRE RANGES.
BY SATURDAY AFTERNOON...A PRETTY STRONG PACIFIC LOW PRESSURE
SYSTEM LOOKS TO MOVE INTO SOUTHERN IDAHO. A FRONTAL BOUNDARY
BEGINS TO SAG SOUTH INTO CENTRAL WYOMING LATE SATURDAY NIGHT AND
ENDS UP DOWN NEAR THE COLORADO/WYOMING BORDER BY SUNDAY MORNING.
PRETTY COLD 700MB TEMPERATURES BEHIND THE FRONT...GFS SHOWING -6
TO -8C 700MB TEMPERATURES ACROSS MOST OF SOUTHEAST WYOMING SUNDAY
MORNING. UPPER SHORTWAVE SUNDAY MORNING TRACKS INTO NORTHERN UTAH
AND ACROSS NORTHERN COLORADO DURING THE DAY SUNDAY. NEW ECMWF VERY
SIMILAR TO THE GFS ON THE TRACK OF THIS SHORTWAVE...IT IS EVEN
COLDER THAN THE GFS THOUGH WITH 700MB TEMPERATURES OF -8 TO -10C
BY SUNDAY AFTERNOON. WENT MUCH COLDER THAN GUIDANCE ON
TEMPERATURES SUNDAY AND BOOSTED POPS OVER GUIDANCE AS WELL.
PROBABLY NOT COLD ENOUGH THOUGH AND LATER SHIFTS WILL NEED TO
LOWER EVEN MORE.
THIS SYSTEM FINALLY PUSHES SOUTHEAST SUNDAY NIGHT INTO MONDAY.
LOOKS LIKE A PRETTY COLD MORNING MONDAY WITH LOWS IN THE 20S FOR
MANY LOCATIONS. SHOULD START TO SEE A REBOUND IN TEMPERATURE
THOUGH MONDAY AFTERNOON AS 700MB TEMPERATURES CLIMB TO ABOVE
FREEZING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 627 AM MDT WED MAY 7 2014
WIDESPREAD LOW CLOUDS AND FOG THIS MORNING THROUGH AT LEAST 16-17Z
TIME FRAME BEFORE CLOUDS BEGIN TO BREAK UP. LATEST HRRR FORECAST
DOING VERY WELL ON THIS STRATUS AND FOG AND GENERALLY FOLLOWED ITS
GUIDANCE. CONVECTION STILL LOOKS TO BE A GOOD POSSIBILITY THIS
AFTERNOON AND EARLY EVENING. THEN TONIGHT...WITH COLDER
TEMPERATURES...WE SHOULD SEE RAIN TURN OVER TO SNOW WITH IFR/LIFR
RETURNING.
&&
.FIRE WEATHER...
ISSUED AT 408 AM MDT WED MAY 7 2014
NO FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK. VERY WET LATER
TODAY THROUGH TONIGHT. RAIN AND SNOW FOR MUCH OF THE AREA. COULD
SEE SNOW ACCUMULATIONS IN SOME PLACES. DRIER FOR FRIDAY AND
SATURDAY WITH A FEW SHOWERS HERE OR THERE...THEN ANOTHER LARGE
STORM SYSTEM POSSIBLE SATURDAY NIGHT AND SUNDAY WITH SNOW
POSSIBLE ESPECIALLY OVER SOUTHEAST WYOMING.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH LATE TONIGHT FOR
WYZ119.
NE...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH LATE TONIGHT FOR
NEZ020-021-054-055.
&&
$$
UPDATE...SML
SHORT TERM...SML
LONG TERM...CLAYCOMB
AVIATION...CLAYCOMB
FIRE WEATHER...SML
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1110 PM MDT TUE MAY 6 2014
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY NIGHT)
ISSUED AT 320 PM MDT TUE MAY 6 2014
HIGH CLOUD COVER LIMITED SFC HEATING OVER MUCH OF THE PLAINS THROUGH
MIDDAY...HOWEVER MUCH BETTER CLEARING IS NOW SEEN OVER THE CWA.
DEWPOINTS ACROSS THE PLAINS ARE LARGELY IN THE 40S SO THERE IS
DECENT LLVL MOISTURE. WOULD BE MOST CONCERNED ABOUT STRONG TO
MARGINALLY SEVERE STORMS IN CONVERSE COUNTY. THE RUC INDICATES
AROUND 1000 J/KG OF SFC BASED CAPE THROUGH THE EARLY EVENING ALONG
WITH GOOD DEEP LAYER SHEAR OF 50 KTS. THE HRRR MODELS HAS ALSO BEEN
CONSISTENT AT SHOWING A DISCRETE CELL JUST TO THE NORTH OF CONVERSE
COUNTY. NOT AS MUCH INSTABILITY (AROUND 500 J/KG OF CAPE) IS FCSTED
OVER THE WESTERN NEBRASKA PANHANDLE...SO NOT AS CONCERNED ABOUT
STRONG STORMS OUT THERE. ANY STORMS THAT DO DEVELOP SHOULD WEAKEN
BY LATE EVENING. ONE MORE MILD NIGHT ACROSS THE CWA AHEAD OF THE
UPPER TROUGH THAT IS LOCATED OVER UTAH. SFC LOW STRENGTHENS OVER
NORTHEASTERN COLORADO BY LATE WED MORNING WITH NORTHEAST WINDS
DEVELOPING ACROSS THE PLAINS.
WEATHER CONCERN FROM LATE MORNING WED THROUGH THE AFTN WILL BE ON
THE SEVERE THREAT OVER THE EXTREME SOUTHEASTERN PART OF THE CWA. SPC
HAS A SLIGHT RISK OVER THE SOUTHERN HALF OF THE PANHANDLE. CAPE
VALUES INCREASE TO AROUND 1000 J/KG BY 18Z ALONG INTERSTATE 80 IN
THE SOUTHERN PANHANDLE. 0-3 KM HELICITY IS CLOSE TO 300 ALONG 0-6
KM SHEAR VALUES OF 55 KTS. THINKING THAT HAIL WILL BE THE PRIMARY
THREAT...BUT CAN NOT RULE OUT A WEAK TORNADO WITH THE GOOD LLVL
SHEAR. THE WINDOW FOR SVR WEATHER SHOULD NOT EXTEND MUCH LATER THAN
THE EARLY AFTN HOWEVER...AS WINDS BECOME NORTHERLY BY LATE AFTN AND
INSTABILITY IS ON THE DECREASE BEHIND THE FRONT.
THE MODELS HAVE BEEN CONSISTENT WITH THE TRACK OF THE UPPER LEVEL
SYSTEM. IT PUSHES INTO NORTHEASTERN COLORADO ON WED EVENING AND
THEN BEGINS TO CLOSE OFF OVER SOUTHWESTERN NEBRASKA BY LATE WED
NIGHT. A TROWAL IS SHOWN PUSHING INTO THE WESTERN NEBRASKA
PANHANDLE BETWEEN 00-12Z THURS. EXCELLENT DEEP LAYER UPWARD MOTION
IS DEPICTED LATE WED AFTN AND INTO THE EVENING OVER THE PLAINS OF
SOUTHEAST WY...WHICH THEN SHIFTS INTO THE NEBRASKA PANHANDLE AFTER
06Z. THUS...STILL EXPECTING A WIDESPREAD HEAVY QPF EVENT FOR MUCH
OF THE PLAINS. HPC HAS THE PANHANDLE IN A SLIGHT RISK FOR EXCEEDING
FLASH FLOOD GUIDANCE. MUCH OF THE PRECIP WILL FALL AS RAIN OVER THE
PLAINS...HOWEVER A TRANSITION TO SNOW COULD OCCUR AFTER AROUND 09Z
FOR ELEVATIONS ABOVE 5000 FT OR SO. THE GFS HAS BEEN CONSISTENTLY
THE WARMEST IN THE POST FRONTAL AIRMASS AS IT KEEPS SFC WET BULB
TEMPS ABOVE 37F TO THE EAST OF THE LARAMIE RANGE THROUGH WED
NIGHT...WHEREAS THE NAM IS CLOSE TO FREEZING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 320 PM MDT TUE MAY 6 2014
MEDIUM RANGE MODEL GUIDANCE IS IN EXCELLENT AGREEMENT WITH A POTENT
UPPER-LEVEL SHORTWAVE AND ASSOCIATED SFC LOW EJECTING NORTHEAST INTO
THE CENTRAL PLAINS EARLY IN THE PERIOD. BOTH THE GFS AND NAM SHOW A
DISTINCT TROWAL FEATURE ON THE BACK SIDE OF THE LOW OVER THE WESTERN
PANHANDLE. THIS COMBINED WITH GOOD QG ASCENT WILL MOST LIKELY YIELD
A CONTINUATION OF MODERATE TO HEAVY PCPN FROM THE PANHANDLE INTO
EAST CENTRAL WY BETWEEN 12-18Z THU. WITH 700-850 TEMPS BETWEEN 0 AND
-5 C...WOULD EXPECT RAIN TO AT LEAST MIX WITH SNOW ESPECIALLY OVER
THE HIGHER TERRAIN NEAR THE PINE RIDGE. NOT THINKING RATES WILL BE
HIGH ENOUGH FOR SIGNIFICANT ACCUMULATIONS...BUT STILL CANNOT RULE
OUT A FEW INCHES OF SNOW OVER OUR NORTHERN ZONES IN THE DEEPER COLD
AIR. BEST FORCING AND MOISTURE SHIFTS NORTH AND EAST OF THE CWA BY
EARLY AFTN...WITH PCPN CHANCES DIMINISHING THEREAFTER.
QUASI-ZONAL FLOW ALOFT RETURNS TO THE AREA ON FRI AND SAT WITH A FEW
NUISANCE DISTURBANCES EMBEDDED WITHIN. DESPITE SOME MODEST COOLING
ALOFT FROM TIME TO TIME...WESTERLY DOWNSLOPE FLOW WILL GIVE WAY TO
SEASONABLE TEMPS IN THE LOW TO MID 60S OVER THE PLAINS. COULD SEE A
FEW SHOWERS OR RUMBLES OF THUNDER EACH AFTERNOON OVER MUCH OF THE
AREA. GFS CAPES ARE GENERALLY LESS THAN 100 J/KG...BUT WITH STEEP
MID LEVEL LAPSE RATES IN EXCESS OF 8.5 DEG C/KM...A STRAY LIGHTNING
STRIKE CAN NEVER BE RULED OUT.
BIG QUESTIONS COME INTO PLAY FOR THE SECOND HALF OF THE WEEKEND AND
INTO EARLY NEXT WEEK. THE ECMWF REMAINS CONSISTENT WITH A CLOSED LOW
AND TROUGH DIGGING INTO THE FOUR CORNERS WITH SFC CYCLOGENESIS OVER
THE PLAINS OF EASTERN CO. LATEST GEM SHOWS A VERY SIMILAR FEATURE...
SO THIS WILL BEAR WATCHING. 12Z GFS TELLS A DIFFERENT TALE...WITH A
VERY PROGRESSIVE AND POSITIVELY TILTED OPEN WAVE MOVING QUICKLY
ACROSS THE PLAINS. MADE VERY FEW CHANGES TO THE PREVIOUS FCST GIVEN
THESE DIFFERENCES...BUT POTENTIAL EXISTS FOR ANOTHER MAJOR STORM
LATE IN THE PERIOD IF THE ECMWF WERE TO VERIFY. SNOW WOULD AGAIN BE
A GOOD POSSIBILITY AS H7 TEMPS PLUNGE AS LOW AS -10C. REGARDLESS OF
WHICH MODEL IS CORRECT...COOLER AND BREEZY CONDITIONS SEEM TO BE A
GOOD BET LATE IN THE WEEKEND. TRIMMED A FEW DEGREES OFF FCST HIGHS
ON SUN AFTN AS WIDESPREAD CLOUD COVER AND COLD AIR ALOFT DO NOT LEND
CREDENCE TO HIGHS NEAR 60F.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 1108 PM MDT TUE MAY 6 2014
THE MAIN CONCERN WITH TAF ISSUANCE IS THE POTENTIAL FOR
THUNDERSTORMS ALONG WITH IFR/MVFR CEILINGS DEVELOPING OVER THE
PANHANDLE OVERNIGHT. THUNDERSTORMS WILL GENERALLY BE ISOLATED IN
NATURE UNTIL 3AM OVER THE SOUTHERN AND CENTRAL PANHANDLE WITH
ANOTHER CHANCE OF STRONG TO SEVERE TSTORMS ON WEDNESDAY EAST OF
THE LARAMIE RANGE. OTHERWISE...LOW CIGS AND NEAR IFR CONDITIONS
WILL BEGIN TO DEVELOP AROUND 08Z ACROSS THE NEBRASKA PANHANDLE
DUE TO MOIST UPSLOPE FLOW...AND MAY PUSH INTO FAR SOUTHEAST
WYOMING. PATCHY FOG IS ALSO POSSIBLE EARLY WEDNESDAY MORNING.
&&
.FIRE WEATHER...
ISSUED AT 320 PM MDT TUE MAY 6 2014
VERY DRY CONDITIONS EXIST TO THE WEST OF THE LARAMIE RANGE THIS
AFTERNOON WITH RELATIVE HUMIDITY VALUES AT 10-15 PERCENT. SOUTHWEST
WINDS ARE ALSO GUSTING TO 30 MPH. HOWEVER...FUELS ARE NOT
SUPPORTIVE OF FIRE GROWTH WITH THE GREENUP IN PROGRESS. A STORM
SYSTEM WILL MOVE ACROSS THE REGION ON WEDNESDAY AND WEDNESDAY NIGHT
WITH AN EXCELLENT CHANCE OF WETTING PRECIPITATION...ESPECIALLY ALONG
AND EAST OF THE LARAMIE RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...HAMMER
AVIATION...CLAYCOMB
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
858 PM PDT THU MAY 8 2014
.SYNOPSIS...A WEAK PACIFIC STORM SYSTEM WILL BRING AREAS OF LIGHT
RAIN TO THE SAN FRANCISCO BAY AREA AND PORTIONS OF THE CENTRAL
COAST THROUGH TONIGHT...WITH A FEW LIGHT SHOWERS POSSIBLY
PERSISTING IN NORTHERN MONTEREY COUNTY INTO FRIDAY MORNING. DRY
CONDITIONS WILL RETURN THIS WEEKEND ALONG WITH BRISK NORTHWEST
WINDS AND NEAR NORMAL TEMPERATURES. A SIGNIFICANT WARMING TREND
IS FORECAST EARLY NEXT WEEK AS AN UPPER LEVEL RIDGE BUILDS ALONG
THE WEST COAST AND WINDS TURN OFFSHORE.
&&
.DISCUSSION...AS OF 8:55 PM PDT THURSDAY...A WEAK AND DISSIPATING
FRONTAL BOUNDARY HAS BEEN PUSHING INTO OUR AREA SINCE LATE
AFTERNOON. LIGHT RAIN HAS BEEN REPORTED THROUGHOUT THE NORTH
BAY...BUT RAIN REPORTS SOUTH OF THE GOLDEN GATE HAVE BEEN MUCH
LESS COMMON. RAINFALL AMOUNTS HAVE MOSTLY BEEN LESS THAN A TENTH
OF AN INCH...ALTHOUGH ISOLATED PORTIONS OF THE NORTH BAY HAVE
PICKED UP BETWEEN A QUARTER AND A HALF INCH. EXPECT RAINFALL TO
TAPER OFF IN THE NORTH BAY THROUGH THE REMAINDER OF THE
EVENING. AREAS OF SPRINKLES OR LIGHT RAIN MAY CONTINUE SOUTH OF
THE GOLDEN GATE THROUGH THE REMAINDER OF THE NIGHT AS THE WEAK
FRONTAL BOUNDARY PUSHES TO THE SOUTHEAST.
THE 00Z NAM CONTINUES TO DROP LIGHT PRECIP ACROSS NORTHWEST
MONTEREY COUNTY INTO FRIDAY MORNING. THIS SEEMS REASONABLE
GIVEN THE MOIST NORTHWEST FLOW THAT IS FORECAST TO PERSIST INTO
TOMORROW MORNING. A RECENT FORECAST UPDATE INCLUDED ADDING A
SLIGHT CHANCE OF SHOWERS TO NORTHWEST MONTEREY COUNTY THROUGH LATE
FRIDAY MORNING. DRY CONDITIONS ARE EXPECTED TO RETURN TO THE
ENTIRE AREA BY FRIDAY AFTERNOON AS INCREASING NORTHWESTERLY FLOW
ADVECTS A DRIER AIRMASS INTO THE REGION. NORTHWEST WINDS WILL
GUSTS LOCALLY AS HIGH AS 35 MPH ALONG THE IMMEDIATE COAST BY LATE
TOMORROW AFTERNOON. BRISK NORTHWEST WINDS WILL THEN CONTINUE FOR
COASTAL AREAS INTO SATURDAY AND SATURDAY EVENING AS A STRONG
SURFACE HIGH BUILDS OFF THE NORTHERN CALIFORNIA COAST. TEMPERATURES
TOMORROW AND SATURDAY WILL BE NEAR NORMAL TO SLIGHTLY BELOW
NORMAL.
ON SATURDAY NIGHT THE SURFACE HIGH OFFSHORE IS FORECAST TO BUILD
INLAND TO OUR NORTH AND EAST...CAUSING WINDS TO VEER TO THE NORTH
AND INCREASE IN THE HILLS BY LATE SATURDAY NIGHT. THIS WILL BRING
A MUCH DRIER AIRMASS INTO THE REGION AND BEGIN TO INCREASE FIRE
WEATHER CONCERNS. WINDS WILL REMAIN LOCALLY STRONG AND GUSTY IN
THE HILLS THROUGH SUNDAY MORNING AND THEN GRADUALLY SUBSIDE SUNDAY
AFTERNOON AND EVENING. IN ADDITION TO OFFSHORE NORTHERLY FLOW ON
SUNDAY...THE AIRMASS ALOFT WILL START TO WARM AS AN UPPER RIDGE
BEGINS TO BUILD JUST OFFSHORE. THE RESULT WILL BE A SHARP RISE IN
TEMPERATURES ON SUNDAY. HIGHS WILL BE ABOUT TEN DEGREES WARMER ON
SUNDAY COMPARED TO SATURDAY...AND AS MUCH AS 15 DEGREES WARMER AT
THE COAST. SUNDAY WILL DEFINITELY BE THE BETTER BEACH DAY THIS WEEKEND.
THE WARMING TREND THAT WILL BEGIN ON SUNDAY WILL CONTINUE THROUGH
THE FIRST HALF OF NEXT WEEK AS LIGHT OFFSHORE FLOW PERSISTS AND THE
UPPER RIDGE CONTINUES TO STRENGTHEN NEAR THE WEST COAST. 850 MB
TEMPERATURES ARE FORECAST TO CLIMB TO 23-24 DEG C OVER PORTIONS OF
OUR AREA BY THE MIDDLE OF NEXT WEEK. THIS MEANS THE AIRMASS OVER
OUR AREA WILL BE AT LEAST A FEW DEGREES C WARMER THAN IT WAS
DURING OUR LAST HEAT EVENT AT THE END OF APRIL AND FIRST FEW DAYS
OF MAY. THUS...EXPECT INLAND TEMPERATURES TO CLIMB INTO THE 90S BY
TUESDAY AND WEDNESDAY WITH A FEW OF THE WARMER INLAND LOCATIONS
EXPECTED TO REACH THE CENTURY MARK BY MIDWEEK. LIGHT OFFSHORE FLOW
WILL MEAN COASTAL AREAS WILL BE VERY WARM AS WELL...BUT JUST HOW
WARM DEPENDS ON THE STRENGTH AND PERSISTENCE OF OFFSHORE FLOW WHICH
IS A BIT DIFFICULT TO PREDICT THIS FAR IN ADVANCE. THE POTENTIAL
CERTAINLY EXISTS FOR SOME 90S IN COASTAL AREAS BY MIDWEEK.
&&
.AVIATION...AS OF 5:10 PM PDT THURSDAY...FOR 00Z TAFS. WEAK FRONT
IS MOVING INTO THE NORTH BAY AT THIS TIME WITH SOME SPOTTY SHOWERS
ACROSS THE REGION. SOMEWHAT SURPRISINGLY WINDS HAVE TURNED SOUTHEAST
AT THE BUOYS AND SOME AIRPORTS. NONE OF THE MESOSCALE MODELS
REALLY CAPTURED THIS BUT LATEST RAP RUN DOES AND SHOWS WINDS
SWITCHING BACK TO MORE WESTERLY BY ABOUT 05-06Z THIS EVENING SO
WOULD EXPECT SOUTHERLY WINDS AT KSFO FOR THE EVENING HOURS. CIGS
LOOK TO GENERALLY STAY AROUND 2000 FEET OR HIGHER
TONIGHT...EARLIER RAIN AT UKIAH WAS ACCOMPANIED BY BKN023. THE
FRONT SHOULD BE GONE BY SUNRISE AND BRISK NW WINDS AND DRYING
SHOULD MIX CIGS OUT FAIRLY EARLY WITH STRONG NW WINDS TOMORROW
AFTERNOON POSSIBLE AT KSFO.
VICINITY OF KSFO...EXPECT SOUTHERLY WINDS TO CONTINUE THIS EVENING
AS WEAK FRONT MOVES THROUGH WITH WIND GUSTS IN EXCESS OF 15 KT.
CIGS SHOULD STAY ABOVE 2000 FEET IN GENERAL WITH POSSIBLE LIGHT
RAIN SHOWERS THIS EVENING. LOW TO MEDIUM CONFIDENCE.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...FRONT IS TO THE NORTH AND LOW
CLOUDS WILL INCREASE AFTER 03Z ALONG THE COAST...THEN STAY IN
PLACE OVERNIGHT WITH SOME VICINITY SHOWERS/DRIZZLE POSSIBLE AT
KMRY. CLEARING SHOULD OCCUR BY 18Z FRIDAY WITH GUSTY NW WINDS
FRIDAY AFTERNOON. MEDIUM CONFIDENCE.
&&
.MARINE...AS OF 1:20 PM PDT THURSDAY...GENERALLY LIGHT BUT
OCCASIONALLY GUSTY NORTHWEST WINDS ARE EXPECTED TONIGHT AS A COLD
FRONT APPROACHES THE CENTRAL CALIFORNIA COAST. THIS WEAK COLD FRONT
WILL BRING A SLIGHT CHANCE OF SHOWERS TO THE COASTAL WATERS THROUGH
THIS EVENING AS IT MOVES ACROSS THE REGION. WINDS WILL BEGIN TO
INCREASE AND SEA CONDITIONS WILL DETERIORATE ONCE AGAIN FRIDAY
AFTERNOON AS THE SURFACE PRESSURE GRADIENT STRENGTHENS ALONG THE
CALIFORNIA COAST.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.NONE
&&
$$
PUBLIC FORECAST: DYKEMA
AVIATION: RWW
MARINE: CW
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1247 AM CDT FRI MAY 9 2014
.DISCUSSION...
818 PM CDT
FOR EVENING UPDATE...
SHOWER/THUNDERSTORM COVERAGE AND INTENSITY PLAYING OUT AS EARLIER
DISCUSSED...WITH CONVECTION GENERALLY STRUGGLING AS IT MOVES INTO
NORTH CENTRAL IL. LOSS OF DIURNAL HEATING AND ASSOCIATED LOW-LEVEL
INSTABILITY HAS DECREASED MARGINAL SEVERE THREAT...THOUGH WILL
CONTINUE TO MONITOR CELLS MOVING OUT OF WEST-CENTRAL IL FOR ANY
STRONGER CORES THAT MIGHT STILL BE ABLE TO PRODUCE SOME SMALL HAIL
OR MARGINAL WIND GUSTS. OTHERWISE...AREA OF RAIN AND EMBEDDED
THUNDER OVER EASTERN MISSOURI IS EXPECTED TO SHIFT NORTHEAST INTO
OUR REGION AFTER MIDNIGHT IN ASSOCIATION WITH MID-LEVEL SHORT WAVE
AND INCREASING MOISTURE TRANSPORT ON 40-50 KT 850 HPA JET. REGIONAL
RADAR MOSAIC AND ORIENTATION OF MOIST PLUME OVERNIGHT SUGGESTS FOCUS
WILL BE IN OUR CENTRAL/SOUTHEASTERN CWA...THOUGH LARGER SCALE HEIGHT
FALLS AHEAD OF DEEP UPPER TROUGH LIFTING INTO THE UPPER MIDWEST AND
APPROACH OF SURFACE COLD FRONT TOWARD MORNING SHOULD BOTH WORK TO
INCREASE COVERAGE OF SHOWERS/THUNDERSTORMS OVER NORTHWESTERN CWA AS
WELL PRE-DAWN FRIDAY MORNING. EXTENT OF CLOUDINESS AND MORNING
PRECIP RAISES QUESTIONS ABOUT EXTENT OF THUNDERSTORM/SEVERE THREAT
FRIDAY AFTERNOON...THOUGH FRONT SLOWS UP IN THE AFTERNOON ACROSS
NORTHWEST IN/EAST CENTRAL IL AND INDICATES BEST CHANCES FOR
PRECIP/THUNDER FRIDAY AFTERNOON MAINLY ACROSS ABOUT THE SOUTHEAST
1/3 OF THE FA.
HAVE MADE SOME ADJUSTMENTS TO HOURLY POP/WX GRIDS TO PROVIDE A
LITTLE MORE DETAIL IN TIMING AND PLACEMENT OF EXPECTED ROUNDS OF
PRECIP THROUGH FRIDAY...WITH POPS LOWERED FROM THE WEST/NORTHWEST
BEHIND THE FRONT ON FRIDAY AND GRADIENT FROM NO POPS NORTHWEST TO
LIKELY POPS IN OUR SOUTHEAST TIGHTENED UP. HAVE ALSO FOCUSED MENTION
OF LOCALLY HEAVY RAINFALL FOR LATE TONIGHT/EARLY FRIDAY MORNING OVER
CENTRAL/SOUTHEAST COUNTIES AS INDICATED ABOVE.
UPDATED GRIDS...ZFP/LFP ALL ALREADY AVAILABLE.
RATZER
//PREV DISCUSSION...
312 PM CDT
MAIN CONCERN FOR THE AREA REMAINS THE CHANCES FOR THUNDERSTORMS.
FOR THE REMAINDER OF THE AFTERNOON AND INTO EARLY THIS
EVENING...CONDITIONS SHOULD REMAIN QUIET AS THE AREA REMAINS IN A
CAPPED WARM SECTOR. THE WARM FRONT HAS PUSHED WELL NO THE NORTH
WHILE A COLD FRONT IS WELL TO THE WEST...EXTENDING FROM DEEPENING
LOW PRESSURE OVER WRN IA/ERN NE SOUTHWEST THROUGH CNTRL KS/WRN OK.
AS LONG AS THE ENVIRONMENT OVER THE LOCAL AREA REMAINS CAPPED...THE
CHANCES FOR ANY PCPN WILL BE LIMITED. CURRENTLY...THE PRIMARY
THUNDERSTORM THREAT IS INVOF THE COLD FRONT/SFC LOW WHERE SPC HAS
ISSUED THE FIRST WATCH OF THE DAY OVER WRN IA/NWRN MN. AS SFC
TEMPERATURES RISE INTO THE UPPER 80S ANTICIPATE THAT THE CAP WILL
ERODE WITH TIME THROUGH THE LATE AFTERNOON AND EARLY EVENING HOURS.
HOWEVER...SOME DRIER AIR IS MIXING DOWN TO THE SURFACE THIS AND SFC
DEWPOINTS HAVE DROPPED INTO THE UPPER 50S...BUT EXPECT THAT
DEWPOINTS WILL REBOUND BACK INTO THE 60S THIS EVENING. SFC BASED
INSTABILITY WILL BE ON THE INCREASE WHILE THE SFC LOW TRACKS TO THE
WRN GREAT LAKES OVERNIGHT TONIGHT AND THE COLD FRONT PUSHES INTO
NWRN IL. STRONG WARM ADVECTION IN THE WARM SECTOR AND LOW LEVEL
FORCING WITH THE COLD FRONT COMBINED WITH UPPER LEVEL FORCING AS THE
REGION WILL BE UNDER THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET
STREAM...WILL PROVIDE THE FOCUS FOR THE DEVELOPMENT OF STRONG
TO...POTENTIALLY...SEVERE THUNDERSTORMS ACROSS NRN IL THROUGH THE
NIGHT. WHILE THERE MAY STILL BE A CHANCE FOR DISCRETE SUPERCELLS TO
DEVELOP AHEAD OF THE COLD FRONT...THE MORE LIKELY CONVECTIVE MODE
TONIGHT IS SHAPING UP TO BE MORE LINEAR...AS THE CONVECTIVE ACTIVITY
TO THE WEST CONSOLIDATES INTO LINES. THUS...THE MORE LIKELY SEVERE
THREAT SHOULD BE LARGE HAIL AND STRONG DAMAGING WINDS. HEAVY
RAINFALL WILL ALSO BE A CONCERN WITH THE THUNDERSTORMS TONIGHT WITH
PWATS FORECAST TO BE ARND 1.7 INCHES. HOWEVER...WITH THE FRONTAL
SYSTEM STEADILY PROGRESSIVE TO THE EAST...DO NOT ANTICIPATE
SIGNIFICANT ECHO TRAINING. SO...LOCALLY HEAVY RAINFALL MAY LEAD TO
URBAN FLOODING CONCERNS...DO NOT ANTICIPATE A WIDESPREAD FLASH FLOOD
THREAT. THE SHORT RANGE MODEL GUIDANCE IS RELATIVELY CONSISTENT ON
THE STEADY PROGRESSION OF THE COLD FRONT...CLEARING THE ERN PORTIONS
OF THE CWA BY EARLY TOMORROW AFTERNOON...THOUGH SOME LINGERING
SHOWERS ARE POSSIBLE INTO THE LATE AFTERNOON HOURS...ESPECIALLY FOR
THE NWRN INDIANA COUNTIES.
FOLLOWING THE PASSAGE OF THE COLD FRONT...A PERIOD OF RELATIVE CALM
IS EXPECTED FOR FRIDAY NIGHT AND SATURDAY AS WEAK HIGH PRESSURE
SPREADS OVER THE MIDWEST. TEMPERATURES FOR FRIDAY AND SATURDAY
SHOULD MODERATE INTO THE LOWER TO MIDDLE 70S. BRISK SWLY FLOW
PERSISTING ON FRIDAY SHOULD ALLOW THE WARMER AIR TO PENETRATE ALL
THE WAY TO THE LAKE FRONT...BUT FOR SATURDAY...A WEAK SFC PRESSURE
GRADIENT AND RELATIVELY LIGHT WINDS SHOULD ALLOW FOR A LAKE BREEZE
TO DEVELOP. WITH ANOTHER LOW DEVELOPING OVER THE CNTRL PLAINS AND
HIGH PRESSURE OVER THE SERN CONUS...SFC WINDS SHOULD BE PREVAILING
SLY TO SWLY...SO...THE LAKE BREEZE SHOULD ASSUME A NW-SE ORIENTATION
AND LIKELY ONLY MOVE INLAND FROM CHICAGO NORTHWARD. WHILE MUCH OF
THE CWA ENJOYS TEMPERATURES BACK IN THE MIDDLE 70S ON SATURDAY...THE
LAKEFRONT LOCATIONS FROM CHICAGO TO WAUKEGAN SHOULD SEE HIGHS ONLY
IN THE LOWER TO MIDDLE 60S.
THE NEXT SIGNIFICANT CHANCE FOR PCPN WILL COME BY SATURDAY EVENING
AS THE AFOREMENTIONED LOW PRESSURE SYSTEM TRACKS THROUGH THE UPPER
MIDWEST AND DRAGGING ANOTHER COLD FRONT ACROSS THE AREA. THIS
SYSTEM IS NOT LOOKING QUITE AS DYNAMIC AS THE SYSTEM EXPECTED THIS
EVENING...SO...THE CHANCES FOR MORE SEVERE WEATHER ARE LOW. A SRN
STREAM SYSTEM LIFTING OUT OF THE SRN ROCKIES BY SATURDAY NIGHT WILL
DEVELOP A WAVE ON THE SRN END OF THE FRONT. THIS WAVE IS FORECAST
TO RIPPLE ALONG THE BOUNDARY TO THE NORTHEAST...WHICH WILL HELP TO
SLOW THE OVERALL PROGRESSION OF THE SYSTEM AND A STRUNG OUT FRONTAL
SYSTEM IS EXPECTED TO EXTEND FROM THE RED RIVER VALLEY INTO THE WRN
GREAT LAKES BY SUNDAY NIGHT. WITH THE FRONT NOT EXPECTED TO PUSH
EAST OF THE AREA UNTIL TUESDAY MORNING...THERE WILL BE AN EXTENDED
CHANCE FOR SHOWERS AND THUNDERSTORMS FROM LATE SATURDAY NIGHT
THROUGH TUESDAY MORNING.
FOR THE LONGER RANGE FORECAST PERIOD...FROM TUESDAY THROUGH
THURSDAY...FOLLOWING THE PASSAGE OF THE COLD FRONT AND THE
ASSOCIATED LOW...THERE WILL STILL BE LINGERING CHANCES FOR SHOWERS
WITH A SERIES OF NRN STREAM SHORT WAVES DROPPING OUT OF CANADA RIGHT
ON THE HEELS OF THE EXITING SYSTEM. WITH SOME UNCERTAINTY TO THE
EXACT TIMING OF THIS SERIES OF SHORTWAVES...WILL CARRY AT LEAST
CHANCE POPS THROUGH THE EXTENDED PERIOD. WITH THE TRAIN OF
SHORTWAVES CARVING OUT A LONG WAVE TROUGH OVER THE GREAT LAKES AND
MIDWEST...TEMPERATURES FOR TUESDAY THROUGH THURSDAY SHOULD BE BACK
TO WELL BELOW NORMAL. HIGHS FOR TUESDAY THROUGH THURSDAY ARE
EXPECTED TO BE IN THE LOWER TO MIDDLE 60S WITH EVEN SOME UPPER 50S
POSSIBLE ALONG THE LAKEFRONT. OVERNIGHT LOWS THROUGH THE EXTENDED
PERIOD SHOULD ONLY BE IN THE 40S.
KREIN
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PERIODS OF SHRA THROUGH THE REST OF THE NIGHT...WITH TSRA ALSO
POSSIBLE AT TIMES. LOW VIS DOWN UNDER 3 SM POSSIBLE IN THE
HEAVIEST SHOWERS.
* GUSTY SOUTHWESTERLY WINDS TODAY.
KJB
//DISCUSSION...UPDATED 06Z...
THE MAIN FORECAST CONCERN IS THE THREAT FOR CONVECTIVE ACTIVITY AT
ACROSS THE EASTERN TERMINALS THROUGH AROUND DAY BREAK.
SHOWERS CONTINUE TO DEVELOP ACROSS CENTRAL ILLINOIS AS MOISTURE
CONTINUES TO STREAM NORTHWARD AHEAD OF LOW PRESSURE ACROSS MN. THESE
DEVELOPING SHOWERS ARE EXPECTED TO TREK NORTHEASTERLY...AND WILL
IMPACT...MAINLY THE EASTERN TERMINALS ACROSS MUCH OF NORTHEASTERN
ILLINOIS AND NORTHWESTERN INDIANA OVER THE NEXT SEVERAL HOURS THIS
MORNING. THIS ACTIVITY WILL RESULT IN SHORT PERIODS OF LOW MVFR TO
IFR VISIBILITIES IN HEAVY RAIN AND I WOULD NOT BE SURPRISED TO HAVE
SOME THUNDERSTORMS MOVE OVER OR NEAR THE TERMINALS.
THINGS SHOULD QUIET DOWN AROUND OR SHORTLY AFTER DAY BREAK
TODAY...WITH THE MAIN THREAT FOR CONVECTION SHIFTING EAST OF THE
TERMINALS DURING THE DAY. WINDS WILL REMAIN GUSTY OUT OF THE
SOUTHWEST...WITH GUSTS LIKELY UP AROUND 25 KT THROUGH MUCH OF THE
DAY. A COOL FRONT WILL SHIFT ACROSS THE AREA BY LATE AFTERNOON/EARLY
EVENING...WITH WINDS EXPECTED TO BECOME MORE WESTERLY AND ABATE BY
EVENING.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH WITH WIND TRENDS.
* HIGH IN SHRA OVERNIGHT...LOW IN VCTS/PREVAILING TSRA AT
TERMINALS.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...DAYTIME VFR...LAKE BREEZE WIND SHIFT POSSIBLE.
SHRA/TSRA POSSIBLE OVERNIGHT.
SUNDAY...PERIODS OF SHRA/TSRA POSSIBLE. SOUTHERLY WINDS.
MONDAY...PERIODS OF SHRA/TSRA POSSIBLE. SOUTH TO SOUTHWEST WINDS.
TUESDAY AND WEDNESDAY...CHANCE SHRA.
RC
&&
.MARINE...
218 PM CDT
A WARM FRONT DRAPED ACROSS THE NORTHERN PART OF THE LAKE LATE THIS
AFTERNOON WILL SHIFT NORTH OF THE LAKE THIS EVENING...YIELDING
SOUTHERLY WINDS ACROSS THE ENTIRE LAKE. GUSTS AROUND 25 KT...AT
TIMES POSSIBLY REACHING 30 KT BRIEFLY...WILL CONTINUE ACROSS
ILLINOIS AND INDIANA NEAR SHORE AREAS THROUGH TONIGHT AND INTO
FRIDAY. STORMS LOOK LIKELY LATE TONIGHT INTO FRIDAY MORNING...A
FEW OF WHICH COULD BE GUSTY. AS THE LOW PRESSURE DRIVING THE
SOUTHERLY WINDS MOVES FROM IOWA THIS AFTERNOON THROUGH ONTARIO ON
FRIDAY IT WILL STEER A COLD FRONT OVER LAKE MICHIGAN ON FRIDAY
NIGHT. THIS FRONT WILL BE WEAKENING THOUGH AND ONLY BRIEFLY TURN
THE WINDS WEST-SOUTHWEST BEFORE TURNING BACK SOUTHERLY THIS
WEEKEND. THE NEXT AREA OF LOW PRESSURE WILL NEAR THE LAKE DURING
LATE SUNDAY INTO MONDAY.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 7 PM FRIDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1106 PM CDT Thu May 8 2014
.DISCUSSION...
ISSUED 835 PM CDT Thu May 8 2014
Convection continues to make slow progress over west central IL
this evening, now advancing along and just east of I-55. Had a
couple of reports of wind gusts of 50 to 60 mph with the storms
late this afternoon but those were few and far between. With the
loss of daytime heating, our instability parameters are not very
impressive across central IL this evening with CAPE values over
most of the area now down below 1000 j/kg. Short term models
suggest as low level jet increases to our southwest later this
evening, we should see more widespread rainfall across the
forecast area during the early morning hours along with mild
temperatures. Have already sent out an update to address the
storms moving into west central IL earlier this evening, but
will send out another update by 900 pm to address the current
thinking on the timing of the rain into eastern IL later this
evening.
Smith
&&
.AVIATION...
ISSUED 1103 PM CDT Thu May 8 2014
Main forecast concern includes coverage of showers and storms
across the forecast area during the early morning hours and
the affects on cigs as the latest model data continues to
suggest cigs deteriorating to MVFR during the early morning
hours.
Another band of rain and storms was pushing NNE across southern
IL late this evening and it appears the bulk of that area of rain
should stay south of our TAF sites. Meanwhile, additional showers
and storms should increasing in coverage over the next several
hours which should help to bring cigs down to MVFR over most of
the area. Still looks as if cigs will drop to between 1500-2500
feet aftr 08z acrs most of the area, with locally lower cigs for a
brief time if any of our TAF sites are affected by a heavier
shower or storm. The MVFR cigs should gradually give way to VFR
cigs by late morning as a cold front shifts across our area. Storm
redevelopment is expected tomorrow afternoon but it still appears
that will be east and south of the TAF sites.
Surface winds will remain out of a southerly direction at 12 to
17 kts overnight with some higher gusts possible in and near any
thunderstorms. Winds will veer more into the southwest and then
west during the afternoon with speeds in the 15 to 20 kt range
with gusts up to 30 kts possible in the afternoon, especially if
we can get some sunshine to break through. VFR conditions are
expected across the entire forecast area tomorrow evening thru
06z.
Smith
&&
.PREV DISCUSSION...
ISSUED 258 PM CDT Thu May 8 2014
Temperatures warming nicely across the forecast area today, with
gusty south-southwest winds and mainly some high clouds. Mostly in
the mid 80s, although some 90 degree temperatures reported at
Champaign and Rantoul at 2 pm. Convection developing as expected
west of the Mississippi River, with one cluster over
Minnesota/Iowa along the warm front, and the second developing
over western Missouri just ahead of the cold front. Both fronts
are tied into a surface low over northeast Nebraska.
Initial forecast concerns are with thunderstorm trends through
Friday including severe threat, followed by timing of
showers/storms for much of the first half of next week.
SHORT TERM...Tonight through Friday Night:
Latest mesoscale analysis showing CAPE`s of 1000-1500 J/kg over
the forecast area, with the cap eroding along the Mississippi
River. Latest HRRR has the storms reaching the Illinois River
valley by around 6 pm and I-57 toward 9-10 pm. Areas west of I-55
most likely to see any severe weather as the instability will be
decreasing by the time the storms make it further east. Hail/wind
remains the primary concern with the storms. Secondary line of
showers/storms immediately ahead of the front will begin to move
in after midnight, but think the severe threat will be be over by
that point.
Extent of overnight convection will dictate where the severe
threat is for Friday. Areas south of I-70 would be most likely as
the front comes in and with outflows from the earlier convection
around, but additional instability would likely have to come
during the afternoon in between periods of storms. Will mention
categorical PoP`s over 80% across the southeast third of the
forecast area through the day, with not the rain not fully moving
out of the southeast CWA until closer to midnight. Further west,
will largely go dry west of I-55 during the afternoon.
LONG TERM...Saturday through Thursday:
Short period of dry weather on tap for Saturday as a narrow ridge
axis slides by, but next wave will be approaching from the Plains.
Have added some slight chance PoP`s in the afternoon west of I-55,
but main period of convection will develop Saturday night. Will
introduce likely PoP`s late Saturday night across about the
northwest 2/3 of the forecast area, lingering into Sunday across
the north as remnants of an MCS move across the area.
The forecast from Sunday night into Monday night is more of a
challenge. The GFS is much faster than the ECMWF or Canadian
models by surging a cold front through the area Monday night,
while the latter models are close to 24 hours slower. This slower
solution would keep a good part of Sunday night and Monday dry.
This appears to be tied into phasing of the long wave trough across
the Rockies Sunday night, with the GFS featuring a more
progressive wave and the ECMWF cutting off a low over the northern
Dakotas for a time early next week. Am trending the blended model
grids on the slower side, but have not completely eliminated any
PoP`s Monday/Tuesday.
Deep upper trough over the central U.S. to provide a period of
cooler weather for the middle of the week. Will see highs only in
the 60s much of the Tuesday-Thursday period.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
302 AM MDT FRI MAY 9 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 258 AM MDT FRI MAY 9 2014
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS
CONFLUENT FLOW ENTERING ROCKIES OVER PLAINS ON BACK SIDE OF
DEPARTING TROUGH...WITH WEAK SHORTWAVE ENERGY UPSTREAM NEAR DIFLUENT
FLOW OVER GREAT BASIN. AT THE SURFACE HIGH PRESSURE IS IN PLACE OVER
OUR CWA WITH STATIONARY FRONT ALONG FRONT RANGING AND COLD FRONT OVER
OK/TX PANHANDLES. RADAR SHOWS SOME VIRGA AND VERY LIGHT SPRINKLES
LINGERING AS A SHORTWAVE IS EJECTING ACROSS THE SOUTHERLY PLAINS.
WITH SUBSIDENCE BUILDING IN FROM THE NORTH THIS ACTIVITY LIKELY WONT
LAST LONG. TEMPS HAVE DROPPED INTO THE MID 30S ACROSS THE WEST...AND
WE COULD SEE A FEW LOW TEMPS AROUND FREEZING BY SUNRISE.
A WEAK SHORTWAVE TROUGH WILL PASS NORTH OF THE CWA THIS AFTERNOON
AND EVENING AND MAY COMBINE WITH AFTERNOON/EVENING INSTABILITY TO
PRODUCE A FEW THUNDERSTORMS OVER NE COLORADO. VERY DRY LOW LEVELS
WOULD LIMIT PRECIP REACHING THE SURFACE. DECIDED TO KEEP SMALL AREA
OF OUR NW CWA WITH ISO THUNDER AROUND 00Z AND OTHERWISE LIMITED
PRECIP MENTION TO SPRINKLES. SEASONAL TEMPS SHOULD RETURN AS SOUTHERLY
FLOW REDEVELOPS TODAY...WITH HIGHS IN THE 70S AND OVERNIGHT LOWS
TONIGHT IN THE LOW-MID 40S (MAYBE A FEW SPOTS A LITTLE COLDER WEST).
SATURDAY-SUNDAY NIGHT...COMPLICATED FORECAST AS THE NEXT STRONG
UPPER TROUGH IS EXPECTED TO IMPACT THE CENTRAL ROCKIES AND PLAINS.
SOUTHWESTERLY FLOW DEVELOPS ACROSS THE ROCKIES WHICH WOULD
INITIALLY LIMIT ANY SHOWER/THUNDERSTORM CHANCES TO THE NW
SATURDAY. HOWEVER BY SATURDAY NIGHT THE MAIN TROUGH BEGINS TO SLIDE
EAST ALLOWING GOOD MOISTURE AND LIFT OT BUILD OVER THE CWA. BEST
PRECIP CHANCES ACROSS THE CWA STILL LOOKS TO BE ON SUN/SUN NIGHT AND
MODELS SHOW REASONABLE AGREEMENT ON MEASURABLE PRECIP SO I BUMP
POPS INTO 60-70 RANGE FOR THOSE PERIODS. A LITTLE LESS CONFIDENT ON
AREA OF BEST PRECIP...THOUGH PARTS OF THE REGION (ESPECIALLY WEST)
COULD SEE DECENT LIQUID ACCUMULATION WITH THIS EVENT (0.15-0.75").
REGARDING WEATHER TYPE...VERY LIMITED INSTABILITY THROUGH MOST OF THE
EVENT...SO ONLY KEPT THUNDER MENTION SATURDAY AFTERNOON/EVENING.
TEMP PROFILES AND WBZ HEIGHTS WOULD INDICATE A RAIN/SNOW MIX OR A
COMPLETE CHANGEOVER ACROSS THE WESTERN HALF OF THE CWA SUNDAY NIGHT.
WARM GROUND TEMPS MAY LIMIT ANY SNOW ACCUMULATION (ASSUMING LIGHTER
RATES). IN ADDITION TO WARM GROUND TEMPS...CONFIDENCE OF CHANGEOVER
TIMING IS LOW SO I LEFT ACCUMULATION MENTION OUT OF FORECAST. I DID
INCLUDE RAIN/SNOW MENTION AND A BRIEF PERIOD OF ALL SNOW AROUND
SUNRISE EARLY MONDAY MORNING. WILL NEED TO WATCH HOW THIS SYSTEM
EVOLVES TO ZERO IN ON THESE DETAILS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 258 AM MDT FRI MAY 9 2014
MODELS ARE STILL IN DISAGREEMENT WITH THE POSITION AND PROGRESSION
OF THE UPPER LEVEL TROUGH IN THE EXTENDED. GFS STILL MOVES IT
FURTHER EAST MORE QUICKLY THAN THE ECMWF. HOWEVER...THE TROUGH WILL
CONTINUE TO INFLUENCE THE CWA ON MONDAY. TEMPERATURES MONDAY MORNING
APPEAR COLD ENOUGH FOR LIGHT SNOW TO CONTINUE OVER EASTERN COLORADO
WITH A RAIN SNOW MIX IN NORTHWEST KANSAS IN COUNTIES BORDERING
EASTERN COLORADO. TEMPERATURES SHOULD WARM ENOUGH BY 15Z FOR ALL
PRECIPITATION TO BE RAIN...WITH THE CHANCE FOR RAIN CONTINUING
MONDAY AFTERNOON. MONDAY WILL REMAIN BREEZY AS THE TIGHT PRESSURE
GRADIENT STAYS OVER THE CWA UNTIL MONDAY NIGHT WHEN IT RELAXES AND
SURFACE HIGH PRESSURE SETTLES IN OVER COLORADO. TUESDAY THROUGH
WEDNESDAY SHOULD REMAIN DRY AS THE UPPER LEVEL RIDGE OVER THE
WESTERN UNITED STATES BECOMES MORE INFLUENTIAL IN THE HIGH PLAINS.
BY THURSDAY...A SHORTWAVE TROUGH WILL ROTATE AROUND THE UPPER TROUGH
OVER THE GREAT LAKES REGION SENDING A WEAK COLD FRONT THROUGH THE
CWA. SHOWERS AND THUNDERSTORMS COULD DEVELOP AHEAD OF THE
FRONT...SINCE THE GFS DOES HAVE A FEW HUNDRED J/KG OF CAPE OVER
EASTERN COLORADO. AS PREVIOUSLY MENTIONED...THE MODELS ARE HAVING A
HARD TIME COMING TO A CONSENSUS FOR ANY DAY IN THE EXTENDED...SO AM
TRYING TO GET AWAY FROM GETTING TOO DETAILED FOR THUNDERSTORM
POTENTIAL IN DAY 7.
WELL BELOW AVERAGE TEMPERATURES CAN BE EXPECTED TO START OFF THE
EXTENDED PERIOD WITH HIGHS ON MONDAY IN THE LOW TO UPPER 50S. LOWS
MONDAY NIGHT WILL BE IN THE LOW 30S TO LOW 40S WITH HIGHS ON TUESDAY
IN THE LOW TO MID 60S. SLIGHTLY BELOW TO NEAR NORMAL TEMPERATURES
WILL TAKE OVER THROUGH THE REST OF THE EXTENDED WITH HIGHS IN THE
MID 60S TO LOW 70S ON WEDNESDAY AND THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1111 PM MDT THU MAY 8 2014
VFR CONDITIONS WILL PREVAIL AT MCK AND GLD THROUGH THE TAF PERIOD.
LIGHT NORTH TO NORTHWEST WINDS WILL TURN SOUTHWEST BY MORNING WITH
SOME LIGHT GUSTINESS DURING THE AFTERNOON AS THE LEE SURFACE
TROUGH DEEPENS ALONG THE FRONT RANGE.
&&
.FIRE WEATHER...
ISSUED AT 243 AM MDT FRI MAY 9 2014
WITH WARMER TEMPS AND LOWER TD MIXING TO THE SURFACE
WE COULD SEE RH VALUES WITHIN RFW CRITERIA ACROSS THE SOUTHERN PART
OF OUR FORECAST AREA BOTH TODAY AND SATURDAY AFTERNOON/EARLY EVENING
PERIODS. TODAY WINDS WILL BE WELL BELOW CRITERIA WITH WEAK GRADIENT
IN PLACE...SO NO RFW PRODUCT ANTICIPATED. SW PRESSURE GRADIENT BEGINS
TO INCREASE SATURDAY AHEAD OF DEEPENING UPPER LOW...THOUGH EVOLUTION
OF SURFACE LOW AND FRONT POSITION WILL BE CRITICAL FOR WHERE WINDS
WITHIN RFW CRITERIA WILL CROSS WITH LOW RH. NOT ENOUGH CONFIDENCE AT
THIS POINT TO ISSUE A FIRE WEATHER WATCH FOR SATURDAY...BUT WE WILL
PROBABLY NEED TO MONITOR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...ALW
AVIATION...LOCKHART
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1202 AM CDT Fri May 9 2014
...UPDATE TO AVIATION...
.SYNOPSIS...
ISSUED AT 1007 PM CDT THU MAY 8 2014
Water vapor imagery and 00Z upper air analysis indicate an upper
level trough axis transitioning eastward across the Western High
Plains. Meanwhile, another upper level trough is pushing ashore into
the Pacific Northwest. Near the surface...a cold front extends from
northeastern Kansas southwest into western Oklahoma while high
pressure builds across the Northern Plains. Cool dry air is
filtering southward into western Kansas with surface dewpoints
falling into the 30s(F).
&&
.SHORT TERM...(This evening through Friday)
ISSUED AT 329 PM CDT THU MAY 8 2014
Chances are greatest that most of the forecast area remains dry
tonight. The front has shifted far enough east that the HRRR model
solutions appear more believable than the NAM model`s solution of a
retreating dryline returning moisture and allowing moist deep
convection. The far west central Kansas counties such as Hamilton
and Stanton could see showers and isolated thunderstorms early this
evening associated with convective development over eastern
Colorado. Of the various HiRes models, the NMM cores suggest a PV
anomaly significant enough to produce showers on the backside of the
upper jet, mainly late tonight and overnight. Instability will be
minimal however and probabilities have been kept very low for the
overnight episode. Temperatures overnight should fall into the low 50s
and seen some 40s farther west where clearing is likely by 12
UTC.
Weak westerly downslope surface winds will develop on Friday as
surface high pressure spreads eastward across southeast Kansas
during the afternoon. Other than mid level clouds, mostly sunny
conditions should prevail based on model layer RH fields. The
downslope flow will promote adiabatic warming resulting in boundary
layer warm advection. Models are strongly aligned for highs in the
mid to upper 70s with only bias corrected solutions creating warmer
highs in the low 80s in the far southwest.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 314 PM CDT THU MAY 8 2014
The medium range models continue to show a strong upper level
shortwave digging into the western states this weekend and moving
out into the plains by early next week. The ECMWF, GEM and UKMET
models have all been similar and tend to be slower and deeper with
this wave. The GFS has been more open and progressive with this wave
for several runs. However, it is showing a tendency in its
operational run...as well as some of the ensemble members...to be a
little slower and deeper.
Upper level westerly flow over the central High Plains on Friday
will gradually become more southwesterly by Saturday night as the
upper wave digs into the Intermountain West. As the upper wave
approaches on Sunday, a frontal boundary should moves southward into
western Kansas with a surface low pressure system developing along
the front. There are some model differences in the position of this
front during the day Sunday. The faster GFS has it through all of
western Kansas by later in the afternoon while the other models keep
it farther west. This will have significant impacts on daytime high
temperatures as well as where the best chance for thunderstorms will
be. Given the model tendencies, will keep the front farther west
with a fairly significant temperature gradient across southwest and
south central Kansas. The models show 60 degree dewpoints spreading
northward into the central Plains ahead of this front. We could see
an outbreak of severe storms along the front during the later
afternoon and early evening hours as stronger southwesterly flow
aloft moves into western Kansas.
Chances for showers and thunderstorms will linger into Monday as the
upper trough continues to move out into the Plains but we should be
drying out by Monday night and Tuesday as the upper wave continues
east. Temperatures in Monday-Wednesday time period will be fairly
cool given the 850 millibar temperatures in the single digits.
Temperatures should moderate through the remainder of the extended
period as upper level heights build over the western and central U.S.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1200 AM CDT FRI MAY 9 2014
VFR conditions will prevail at all TAF sites through early Friday
evening. As for winds, surface high pressure in the Northern Plains
will sink southward into western Kansas overnight resulting in light
and variable winds across the area. A lee side trough of low
pressure will develop across eastern Colorado early Friday morning
turning winds southwesterly 10 to 20kt by mid day Friday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 48 82 55 81 / 0 0 10 20
GCK 47 81 50 72 / 0 0 10 10
EHA 50 85 50 77 / 0 0 0 10
LBL 48 86 52 80 / 0 0 10 10
HYS 48 80 52 69 / 0 0 10 20
P28 53 86 61 88 / 0 10 10 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJohnson
SHORT TERM...Russell
LONG TERM...Gerard
AVIATION...JJohnson
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1141 PM CDT Thu May 8 2014
...AVIATION UPDATE...
.UPDATE...
Issued at 1002 PM CDT THU MAY 8 2014
The cold front has started moving east once again and thunderstorm
development has recommenced, likely due to increased low level
convergence and possibly a weak wave lifting north along the KS/MO
state line. Thinking is that instability has weakened from
previous convection and cooling of the boundary layer. Because of
this we have allowed the watch to expire thinking the chances for
widespread severe weather will continue to diminish as the
boundary layer cools. Latest radar data suggest there could be
some small hail with the stronger updrafts, so we`ll have to
continue monitoring storms for a little while longer.
Latest water vapor imagery continues to show another shortwave now
moving into southwest KS. This wave may help some scattered
showers and thunderstorm activity to form late tonight over east
central KS. Because of this have continued with some chance pops
mainly south of I-70.
UPDATE Issued at 634 PM CDT THU MAY 8 2014
Think the cold front will continue to make steady progress east,
however outflow from recent convection seems to have masked the
true front. The latest RAP and HRRR suggest the stronger
convection could be east of the forecast area by 01Z and have
trended the forecast in this direction. As the front makes clear
progress east, will continue to clear out counties from the watch.
Main hazard remains large hail, although available instability
only around 1000 J/kg seems to be limiting the storms ability to
maintain an updraft. Low level shear parameters do not look very
supportive for much of a tornado threat.
&&
.SHORT TERM...(Through Tonight)
Issued at 252 PM CDT THU MAY 8 2014
The main focus for the short term is on the potential for
thunderstorm development, with some strong to severe storms
possible. Water vapor imagery showed the deep mid-level trough
progressing eastward into the High Plains with a swath of dry air
stretching across the western half of Kansas and the cloud cover
gradually diminishing across eastern Kansas. The main surface low
was situated over eastern Nebraska, with a secondary low developing
over western Oklahoma near the Texas panhandle. As of 19z, the radar
and surface obs showed the cold front stretching between these
surface lows being located generally along a line from Seneca to Alma
to Council Grove. Dewpoints ahead of this boundary where still in
the low/mid 60s, with drier conditions settling in behind the
boundary as dewpoints dropped into the upper 40s to upper 50s across
north central Kansas. The cloud cover along with veering winds
behind the front have limited afternoon heating with temperatures
generally in the 70s.
At 19z, radar showed a few showers and thunderstorms beginning to
initiate along this boundary over far eastern/southeast Nebraska.
Short-range models show this development continuing to spread
southward along the boundary into northeast and eastern Kansas after
20z with more scattered storm development by the 22z-00z time frame,
progressing eastward into Missouri during the evening hours. This
region looks to be favorable for the development of strong to severe
supercell thunderstorms as there is limited convective inhibition in
place. MUCAPE is modest with upwards of 1000-2000 J/kg, and there is
decent 0-6km bulk shear of 50-60kts. With the frontal passage,
soundings show some veering of the low-level winds with 0-1km bulk
shear potentially upwards of 15-20kts, so cannot rule out the
potential for a few isolated tornadoes across far eastern Kansas.
However, the main severe threat looks to be large hail with upwards
of golfball size hail possible with the stronger storms. Could also
see some damaging winds with this activity. These thunderstorms
should initially be somewhat scattered in nature, and develop more
into a line of storms by early this evening as the cold front
progresses eastward, with this main thunderstorm activity
diminishing by mid to late evening. However, additional shower and
thunderstorm develop is possible overnight across east central
Kansas as the secondary low tracks northeastward into southeast
Kansas. Expect these storms to be elevated in nature and should exit
east of the area Friday morning.
Winds will continue to veer to the west and northwest behind the
front tonight into Friday morning, with clearing skies across much
of the northwestern half of the forecast area overnight. As a
result, expect to see a spread in low temperatures tonight ranging
from the middle 40s over north central Kansas to the middle 50s
across east central Kansas due to the lingering shower and
thunderstorm activity.
.LONG TERM...(Friday through Thursday)
Issued at 252 PM CDT THU MAY 8 2014
All indications are that the main PV anomaly/trough axis will exit
the forecast area by around 15Z on Friday with a few lingering
showers or even a thunderstorm possible through that time.
Otherwise, expect downward motion and some dry advection to bring
sunshine by afternoon. The post-frontal airmass is substantially
cooler, but expect to mix up to 850 or even 800 hPa with sunshine
and westerly winds, and still expect highs to climb into the 70s.
Nearly zonal upper flow prevails into early Saturday with the front
weakening and stalling over southern KS or northern OK. Should see
dry conditions through Friday night and much of Saturday but expect
the front to return north with warm moist advection Friday night
into Saturday morning as surface low pressure develops from eastern
Colorado into the OK panhandle. So have gone warmer with Friday
night lows, and also a bit warmer on Saturday as cloud cover should
be limited and the airmass rather warm.
By Saturday afternoon, expect a negatively tilted short wave trough
to eject across the Dakotas. This storm system will have a glancing
impact on the local forecast area, but this bit of ascent will
combine with moderate to strong instability expected by Saturday
afternoon, along with a frontal boundary that will likely be
lingering in the area or drifting back south across parts of Kansas.
Expect the cap to be erased by mid to late afternoon, and the
instability in conjunction with 30 to 50 kts of 0-6 km wind shear
should result in scattered thunderstorms developing near the front.
The most likely area seems to be near/south of I-70 at this time,
and some of these storms would likely take on supercell
characteristics with at least some potential for large hail. The
wind potential will at least partially be tied to how warm
temperatures get in the warm sector...warmer equating to greater
damaging wind potential. Tornado potential seems on the low side
given current forecast parameters given expectation for somewhat
veered low level winds...but with a nearly stationary front in play,
some small potential may exist. Expect a weak embedded short wave
trough to perhaps enhance thunderstorm coverage near and even north
of the front as the low level jet intensifies after sunset. This
could allow the hail threat to persist north of the front through
the overnight hours with elevated convection.
On Sunday, expect a deep upper trough to begin to eject into the
central Plains. The surface low is expected to deepen markedly over
the OK panhandle while the surface front should remain across the
local forecast area. One of the most significant uncertainties in
the Sunday forecast regards the location of the front. The ECMWF is
strongest/farthest north with the surface low and hence has the
front extending across north central KS. The NAM...which can be
flaky with details at the end of the forecast run...is stronger with
the cold front progression and has the boundary along the boundary
by 00Z Monday. The GFS is playing middle ground at this time.
Another area of uncertainty lies in any stabilization that may occur
with any overnight/early morning convection as we`ve seen with
recent events. Wherever the boundary is located by Sunday
afternoon, the warm sector south of the front should be
characterized by strong to extreme instability and ample deep layer
wind shear. Thunderstorms are likely to develop by mid afternoon
along the front and become supercellular and severe. Low level winds
again appear to be veered a bit but still with a fair amount of low
level shear. All told, this appears to be an elevated chance for
severe storms along and south of the frontal boundary...again
focused near/south of I-70 for highest chances. The extent of storm
severity will depend on several factors that can not currently be
resolved but given magnitude of shear and instability the potential
for widespread severe is evident.
Showers and thunderstorms are expected to linger into Monday, with
the end time depending on the speed of the upper trough which
appears to be rather slow in its eastward progression. There are
indications of lingering instability into the day on Monday in
eastern KS but severe potential is questionable and quite low at
this time. The upper low is showing a fair potential to slow and
stall invof the western Great Lakes which would keep the local area
in cool NW flow for several days with a fair amount of cloud cover.
This long term forecast is rather uncertain though as even a minor
eastward shift to the upper low would bring more frequent sunshine
and temps would be quite a bit warmer.
&&
.AVIATION...(For the 06Z TAFs through 06Z Friday Night)
Issued at 1141 PM CDT THU MAY 8 2014
With dryer air moving in behind the front, VFR conditions should
prevail. There is still a wave to the west that should move across
the area bringing some mid level clouds overhead through sunrise.
There could also be some -RA but most guidance is keeping any QPF
south of the terminals so will not mention any precip at this
time.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...Wolters
SHORT TERM...Hennecke
LONG TERM...Barjenbruch
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS JACKSON KY
205 AM EDT FRI MAY 9 2014
.UPDATE...
ISSUED AT 205 AM EDT FRI MAY 9 2014
GRIDS AND FORECAST ARE IN FINE SHAPE EARLY THIS MORNING. ONLY MADE
SOME MINOR TWEAKS TO MATCH UP WITH HOURLY TRENDS. LOOKING OVER LATEST
FORECAST SOUNDINGS FOR THIS AFTERNOON...AND THINGS DO NOT LOOK REAL
IMPRESSIVE. BELIEVE MODELS...NAM/GFS ARE OVERDOING SFC MOISTURE AGAIN
AND CONSEQUENTLY SFC BASED INSTABILITY. INTERESTINGLY...GFS MODEL
GUIDANCE IS ADVERTISING ONLY A 20-30 PERCENT CHANGE OF THUNDER. NAM
MET MOS IS HIGHER...BUT ONLY DUE TO THE TYPICALLY HIGHER BIAS IN SFC
DEW POINTS AND IS STILL ONLY SHOWING A 40 PERCENT CHANCE OF THUNDER.
APPEARS THE DRIER RAP MAY HAVE A SLIGHTLY BETTER HANDLE ON THINGS.
IN ADDITION...SOUNDINGS HAVE THAT FAMILIAR INVERTED V PROFILE
TYPICALLY SEEN IN THE WESTERN CONUS. MAY DECIDE TO CUT BACK ON
PROBABILITY OF THUNDER WITH NEXT UPDATE...FROM LIKELY TO CHANCE.
HOWEVER...WITH DRIER LOWER LEVELS THIS ALSO MEANS THAT ANY SHOWERS
THAT DEVELOP WILL TEND TO BE HIGH BASED AND PRODUCE GUSTY WINDS DUE
TO THE ADDITIVE MOMENTUM OF EVAPORATIVE COOLING. BUT WILL
EVALUATE/COLLABORATE WITH NEIGHBORS BEFORE MAKING ANY FINAL
DECISIONS.
UPDATE ISSUED AT 1055 PM EDT THU MAY 8 2014
DID A QUICK UPDATE TO FINE TUNE THE SKY COVER WEST TO EAST OVERNIGHT.
ALSO TWEAKED THE T/TD GRIDS THROUGH THE EARLY OVERNIGHT BASED ON THE
LATEST OBS AND TRENDS. UPDATES HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
UPDATE ISSUED AT 730 PM EDT THU MAY 8 2014
23Z SFC ANALYSIS SHOWS WEAK HIGH PRESSURE HOLDING ON OVER THE
SOUTHEAST PART OF THE NATION WHILE EAST KENTUCKY REMAINS IN THE BROAD
WARM SECTOR OF A LARGE HIGH PLAINS LOW. WARM MID LEVEL TEMPERATURES
CONTINUE TO CAP THE AREA PREVENTING ANY CONVECTION AND LIMITING THE
LOWER CLOUDS TODAY. THIS HELPED SEND TEMPERATURES INTO RECORD AND
NEAR RECORD TERRITORY AGAIN THIS AFTERNOON. SOME HIGH CLOUDS ARE NOW
STARTING TO THICKEN UP OVER THE REGION IN RESPONSE TO THE PLAINS
SYSTEM/S COLD FRONT MOVING EAST. DO NOT EXPECT THESE CLOUDS TO
COMPLETELY COVER THE AREA BEFORE MUCH LATER TONIGHT...BUT THEY WILL
STILL LIKELY IMPACT THE NATURE OF THE PERSISTENT RIDGE AND VALLEY
TEMPERATURE SPLITS THAT WE HAVE BEEN SEEING THE PAST SEVERAL NIGHTS.
WILL STILL FORECAST ONE...PARTICULARLY IN THE EAST...BUT TEMPER IT
FOR MOST OF THE AREA AND FORECAST THE BEST AND FASTEST TEMPERATURE
DECLINES EARLIER IN THE NIGHT. HAVE UPDATED THE GRIDS WITH THESE
THOUGHTS IN MIND...AS WELL AS INCORPORATING THE LATEST OBS AND TRENDS
FOR THE NEAR TERM. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 250 PM EDT THU MAY 8 2014
THE MODELS ACTUALLY HAVE QUITE A BIT OF DIFFERENCE IN THE TIMING OF
THIS NEXT SYSTEM APPROACHING THE AREA TOMORROW. BY 8 PM ON FRIDAY...A
COLD FRONT WILL EXTEND ACROSS WESTERN MICHIGAN TO SOUTHEASTERN
MISSOURI AND THE INTO THE TEXAS MIDLANDS. THERE WILL BE SHOWERS AND
THUNDERSTORMS FIRING UP AHEAD OF THIS SYSTEM ON FRIDAY. THIS IS WHERE
THE MODELS DIVERGE AS TO THE EXTENT AND TIMING OF THE PREFRONTAL
STORMS IN THE WARM SECTOR. THE TIME OF ARRIVAL FOR THE LEADING EDGE IN
THE MODELS VARY FROM 5 PM FRIDAY TO 10 PM ON FRIDAY. THE MODEL
CONSENSUS WOULD FAVOR THE LATER ARRIVAL TIME. THE BEST CHANCE FOR
WIDESPREAD SHOWERS AND THUNDERSTORMS WILL BE LATE FRIDAY NIGHT AND
INTO SATURDAY. THE FRONT SHOULD BE MOVING INTO EASTERN KENTUCKY ON
SATURDAY MORNING. THE THREAT OF ANY SEVERE THUNDERSTORMS WITH THE
SYSTEM IS VERY LOW AND ONLY GARDEN VARIETY STORMS ARE EXPECTED WITH
THIS SYSTEM.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 334 PM EDT THU MAY 8 2014
THE MODELS WERE NOT IN THE BEST OF AGREEMENT THIS GO ROUND...SO THE
EXTENDED PORTION OF THE FORECAST MADE WITH LOW CONFIDENCE. THE
OVERALL PATTERN SUGGESTS A THAT INITIALLY A FAIRLY WELL DEFINED COLD
FRONT WILL MOVE SLOWLY ACROSS THE AREA SATURDAY AND SATURDAY NIGHT.
WITH AMPLE MOISTURE AND INSTABILITY IN PLACE...THE START OF THE
PERIOD DOES LOOK FAIRLY GOOD IN TERMS OF THE VARIOUS MODEL SOLUTIONS
AND THEIR AGREEMENT THERE. THEREFORE...DECIDED TO CONTINUE WITH THE
LIKELY PRECIPITATION PROBABILITIES TO END THE WEEKEND ACROSS THE
AREA. AFTER THAT...HOWEVER...THE MODELS GO QUITE A BIT OUT OF
AGREEMENT. THE GFS IS MUCH FASTER THAN THE ECMWF WITH THE PROGRESSION
OF A LARGE SCALE UPPER TROUGH THROUGHOUT THE WORK WEEK...AND A SERIES
OF FRONTAL BOUNDARIES THAT ARE PROGGED TO AFFECT THE AREA. WITH THE
AMOUNT OF UNCERTAINTY WE ARE SEEING...IT SEEMED PLAUSIBLE TO ADJUST
THE LATEST MODEL DATA INGEST VERY LITTLE AND KEEP IN LINE WITH OUR
NEIGHBORS. IT LOOKS LIKE ISENTROPIC LIFT ASSOCIATED WITH A WARM FRONT
WILL BE THE CULPRIT FOR PRECIPITATION THROUGHOUT THE PERIOD WHEN A
COLD FRONT LOOMS TO OUR WEST IN THE WARM SECTOR OF AN APPROACHING
AREA OF LOW PRESSURE. AT THIS TIME...THE FORECAST WILL CALL FOR
PERIODS OF SHOWERS AND THUNDERSTORMS THROUGHOUT THE WEEK...WITH SOME
BREAKS FROM THE PRECIP HERE AND THERE AS THE WARM MIGRATES NORTH OF
THE OHIO RIVER. TEMPERATURES DURING THE PERIOD SHOULD BE QUITE
WARM...WITH DAILY HIGHS IN THE 70S AND 80S THROUGH TUESDAY. COOLER
TEMPERATURES COULD BE ON TAP TO END THE WEEK...IF A SECOND AREA OF
LOW PRESSURE IN FACT DOES IMPACT THE AREA. TEMPERATURES NEXT
WEDNESDAY AND THURSDAY MAY ONLY MAKE IT INTO THE 60S ACROSS THE BOARD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 205 AM EDT FRI MAY 9 2014
LOOKING AT VFR CONDITIONS THROUGH THE ENTIRE FORECAST PERIOD. MAIN
CHALLENGE TO THE AVIATION FORECAST WILL BE THE POTENTIAL FOR
THUNDERSTORMS LATER TODAY. THINGS DO NOT LOOK REAL IMPRESSIVE BASED
ON LATEST FORECAST SOUNDINGS. BELIEVE MODELS...NAM/GFS ARE OVERDOING
SFC MOISTURE AGAIN AND CONSEQUENTLY SFC BASED INSTABILITY. SOUNDINGS
ALSO HAVE THE FAMILIAR INVERTED V PROFILE TYPICALLY SEEN IN THE
WESTERN CONUS. THOUGHTS ARE THAT WE MAY CUT BACK ON PROBABILITY OF
THUNDER...FROM LIKELY TO CHANCE. HOWEVER...WITH DIRER LOWER LEVELS
THIS ALSO MEANS THAT ANY SHOWERS THAT DEVELOP WILL TEND TO BE HIGH
BASED AND PRODUCE GUSTY WINDS DUE TO THE ADDITIVE MOMENTUM OF
EVAPORATIVE COOLING OF RAINFALL. LIGHT AND VARIABLE WILL INCREASE
FROM THE SOUTH...SOUTHWEST AT 10 TO 15 KTS BY MIDDAY FRIDAY. A FEW
GUSTS TO 20 KTS WILL BE POSSIBLE LATE IN THE DAY FRIDAY. AGAIN...
WINDS COULD BE QUITE VARIABLE AND GUSTY AROUND ANY SHOWERS AND
THUNDERSTORMS THAT MAY DEVELOP.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...JJ
LONG TERM...AR
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1122 PM CDT Thu May 8 2014
.UPDATE...
Issued at 1122 PM CDT THU MAY 8 2014
Update for 6z aviation only.
UPDATE Issued at 845 PM CDT THU MAY 8 2014
A north to south oriented line of thunderstorms with trailing
stratiform rain is approaching the Mississippi River and will
continue to move north northeast into southern Illinois mainly to
the west of I-57 through the remainder of the evening. It looks
like western portions of southeast Missouri will be drying out
pretty soon, and they may have a few hours before the next round
arrives midnight or a bit later.
LAPS soundings indicate a weakening cap and the RAP has LI`s of
-2 to -3 over southern Illinois. See no reason why they will not
continue through much of southern Illinois with modest intensity
this evening. Not sure just how far east they will get, but the
RAP tries hard to confine the precipitation to Missouri and
Illinois through midnight. Of course, as the upper trough pushes
closer to the area overnight, another round of widespread showers
and thunderstorms is expected to overspread most of the area by
daybreak Friday morning.
Tried to account for the aforementioned trends in the hourly
pop/wx grids, but made few other changes with this update.
The Lake Wind Advisory died a natural death at 01Z.
UPDATE Issued at 610 PM CDT THU MAY 8 2014
UPDATE FOR AVIATION ONLY.
&&
.SHORT TERM...(Tonight through Saturday night)
Issued at 304 PM CDT THU MAY 8 2014
Focus in the short term continues to be on convective chances.
Band of convection central/sw MO into west AR will track slowly
east late this afternoon and evening. Will have best chance PoPs
west 1/2 before midnight shifting slowly east overnight. Really
not all that concerned about severe wx over our SEMO counties
at this time given marginal lapse rates modest instability.
Convective chances will shift east Friday morning. It may linger
from SW IN into the Pennyrile through early afternoon, where temps
may be held down a couple of degrees. Otherwise, the atmosphere
should have some time to recover heading west, ahead of an
approaching, stalling front. Convection should take shape in this
area and eventually focus SRN IL into SE MO late in the day in
some form or fashion then head east through the evening. Mid and
upper level winds are relatively impressive, not so much blyr-
700mb. Storms with decent mid level rotation, with steepening low
level lapse rates may yield wind and hailers, best chances
west/southwest part of the CWFA. Chances should diminish from west
to east after midnight Friday night. May see a lull Saturday, then
another chance moving in from the west overnight Saturday night,
potentially an MCS. Slightly better chances north than south.
.LONG TERM...(Sunday through Thursday)
Issued at 304 PM CDT THU MAY 8 2014
The main weather story during the long term will be a strong cold
front that will sweep across our region early next week. This front
will be accompanied by a period of rain and thunderstorms. The front
will bring a noticeable cooling of temperatures from above normal to
below normal.
As far as the daily details...
On Sunday...a reservoir of warm...moist and very unstable air will
cover a large part of the central states including our region. It is
likely that one or more convective systems will develop over the
Plains and then propagate eastward through this unstable air
mass...fed by a moderately strong low level jet. Since there is
little skill at forecasting these systems in the long range
period...the forecast will include a generic chance pop. High temps
will remain quite warm...basically in line with gfs/ecmwf mos.
On Monday...the high amplitude 500 mb trough and associated cold
front will draw closer. The genesis region of convective systems
will remain to our west. Will continue with a warm and humid
forecast along with chance pops.
There remains unusually wide divergence among the models concerning
the timing of the frontal system Monday night through Tuesday night.
Both the gfs and ecmwf have trended slower compared to this time
Wednesday. The 12z gfs takes the front across our region on Monday
night...while the ecmwf has it coming through Tuesday night. The
highest pops will be on Tuesday...mainly in the likely category
across our region. Will introduce chance pops for Wednesday based on
the slower timing of the system. However...the bulk of the precip
should be over by then.
The model 850 temps have trended cooler for Wednesday into Thursday
by several degrees. Based on model 850 mb temps from plus 1 to plus
4...highs will only be in the 60s even with plenty of sun. Forecast
temps will be trended lower for Wed into Thurs.
&&
.AVIATION...
Issued at 1122 PM CDT THU MAY 8 2014
Kcgi is expected to break out of the precip between 6z and 9z.
After that rain will start to move in again. However raised cigs
prevailing and tempo in light of the vfr cigs in tsra earlier.
Slowly bring them into MVFR territory between 9z and 18z. Then
only a prob group after that. Also maintained LLWS overnight as
fcst sounding indicate 40kt at 2k feet.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...KH
AVIATION...KH
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1153 PM CDT THU MAY 8 2014
.AVIATION...
A LINE OF STRONG CONVECTION WILL CONTINUE TO MOVE EAST ACROSS
PORTIONS THE FORECAST AREA EARLY THIS MORNING. EXPECT MODERATE TO
ISOLATED SEVERE TURBULENCE WITH THIS ACTIVITY AS WELL AS PERIODS
OF IFR CIGS AND VSBYS DUE TO HEAVY RAINFALL. FOLLOWING THE
LINE...CIGS MAY CLEAR BRIEFLY ACROSS EAST TEXAS INTO SOUTHEAST
OKLAHOMA AND SOUTHWEST ARKANSAS. HOWEVER...AFTER 09Z...EXPECT IFR
FLIGHT CONDITIONS TO RETURN IN SOME LOCATIONS DUE TO FOG AND/OR
LOW CIGS. ACROSS LOUISIANA...CIGS WILL REMAIN MOSTLY MVFR WITH
OCCASIONAL VSBYS BETWEEN 2 AND 5 MILES IN RAIN AND FOG. CONDITIONS
WILL IMPROVE BETWEEN 15Z AND 17Z FRIDAY TO VFR MOST LOCATIONS.
EXCEPT FOR WEST TO NORTHWEST WIND GUST TO AROUND 25 KTS IN AND
AROUND CONVECTION...SURFACE WIND TO REMAIN SOUTH 5 TO 10 KTS
TONIGHT. AFTER 14Z FRIDAY...EXPECT SOUTH TO SOUTHWEST WIND 10 TO
15 KTS. /14/
&&
.PREV DISCUSSION... /ISSUED 946 PM CDT THU MAY 8 2014/
DISCUSSION...
MOSAIC RADAR ANALYSIS SHOWING A RATHER LARGE LINE OF CONVECTION
EXTENDING FROM SOUTH CENTRAL ARKANSAS THROUGH EXTREME NORTHWEST
LOUISIANA AND NORTHEAST TEXAS. THIS ACTIVITY DEVELOPING WELL AHEAD
OF THE SHORTWAVE TROUGH WHICH IS CURRENT ACROSS THE TX/OK PNHDL
INTO THE SOUTHERN AND CENTRAL PLAINS. HRRR HAS A GOOD HANDLE ON
THIS CONVECTION CONTINUING TO PUSH SOUTH AND EAST THROUGH THE
NIGHT WITH RAINFALL RATES NEAR 1.5 INCHES PER HOUR ALONG THE
LEADING EDGE OF THE CONVECTION. HAVE UPDATED THE FORECAST TO GO
WITH CATEGORICAL POPS ACROSS THE NORTHWEST HALF FOR THE REMAINDER
OF THE EVENING AND THEN ACROSS THE EASTERN HALF AFTER MIDNIGHT.
ALSO ADDED THE LOCALLY HEAVY RAINFALL MODIFIER GIVEN THE RAINFALL
RATES AND WHAT HAS ALREADY OCCURRED.
CONCERNING TEMPERATURES...OUR NORTHWEST ZONES ARE ALREADY A DEGREE
OR TWO BELOW FORECAST MINS SO LOWERED MINS BUT THESE TEMPERATURES
MAY RECOVER SLIGHTLY AFTER THE CONVECTION ENDS.
ALSO ADJUSTED SKY/WIND AND DEWPOINT GRIDS BASED ON CURRENT TRENDS.
UPDATE ALREADY SENT...13.
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 68 84 67 87 68 / 80 40 20 20 20
MLU 71 82 66 86 67 / 80 50 30 20 20
DEQ 64 84 61 85 66 / 80 50 20 20 20
TXK 66 83 66 86 67 / 80 50 40 20 20
ELD 66 83 65 86 66 / 80 50 40 20 20
TYR 66 88 66 88 70 / 80 20 20 20 10
GGG 68 87 66 87 70 / 80 30 20 20 10
LFK 71 89 68 88 70 / 80 30 20 20 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
501 AM EDT FRI MAY 9 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 444 AM EDT FRI MAY 9 2014
THE UPPER TROUGH THAT HAS BEEN CONTROLLING OUR WEATHER FOR THE LAST
COUPLE OF DAYS IS CURRENTLY MOVING NORTHEAST THROUGH THE CENTRAL
PLAINS. MOISTURE LADEN AIR STREAMING NORTHEAST AHEAD OF THIS TROUGH
CAN BE SEEN ON WV IMAGERY EARLY THIS MORNING...WHICH IS HELPING TO
FUEL SHOWERS AND ISOLATED THUNDERSTORMS FROM WESTERN LAKE SUPERIOR
THROUGH PORTIONS OF UPPER MICHIGAN...AND SOUTHEAST TO EASTERN
WISCONSIN. AT THE SURFACE...A 998MB LOW IS LOCATED JUST SOUTHWEST OF
DULUTH AND A WARM FRONT STRETCHES EAST ALONG THE U.P. AND
WISCONSIN BORDER. SHORTWAVES EMBEDDED WITHIN THE WARM MOIST
SOUTHWESTERLY FLOW CONTINUES TO PRODUCE AREAS OF THUNDERSTORMS OVER
THE WESTERN HALF OF THE GREAT LAKES REGION AND EXPECT THAT TO
CONTINUE FOR AREAS WITHIN THE WARM/MOIST AIRMASS.
AS THE LOW LIFTS NORTHEAST TODAY...THE COLD FRONT (CURRENTLY
STRETCHING SOUTH FROM SOUTHEAST MINNESOTA THROUGH NORTHERN
MISSOURI) WILL SWEEP NORTHEAST ACROSS THE UPPER GREAT LAKES REGION.
WITH THE SHOWER/THUNDERSTORM COVERAGE STARTING TO BECOME MORE
SCATTERED/ISOLATED...WILL FOLLOW THAT IDEA FOR POPS AHEAD OF THE
COLD FRONT. ALREADY STARTING TO SEE THE AFFECT OF THE DRYING ALOFT
OVER NORTHWEST WISCONSIN AND EXPECT THE LAST AREAS OF SHOWERS FOR
THIS MORNING TO PUSH THROUGH WESTERN UPPER MICHIGAN OVER THE NEXT
COUPLE OF HOURS. AS THAT DRYING SHIFTS EAST THIS MORNING...WILL
DIMINISH POPS FROM WEST TO EAST DURING THE MORNING HOURS. WITH
THERE STILL BEING SOME ISOLATED THUNDER ON THE BACK EDGE OF THE
PRECIPITATION (EVEN THOUGH RAP ANALYSIS OF MUCAPE AND MID-LEVEL
LAPSE RATE VALUES ARE VERY WEAK)...HAVE EXTENDED THE SLIGHT
CHANCE OF THUNDER A LITTLE LONGER OVER THE EAST THIS MORNING TO
COINCIDE WITH THE AXIS OF MOISTURE AND LATEST THUNDER
AREAS.
BEHIND THE COLD FRONT...MAY SEE A FEW PEAKS OF SUNSHINE OVER THE
CENTRAL/EAST (WHERE FOG ISN/T OCCURRING) AS THIS MID LEVEL DRY SLOT
MOVES THROUGH AND BEFORE THE NEXT WAVE OF LOW LEVEL MOISTURE AND
PRECIPITATION (CURRENTLY IN THE EASTERN DAKOTAS AND WESTERN
MINNESOTA) MOVES OVER THE AREA. WILL CONTINUE THE IDEA SHOWN IN THE
PREVIOUS FORECAST OF ISOLATED TO SCATTERED SHOWERS MOVING OVER THE
WEST OR NORTHWEST HALF OF THE CWA LATER THIS AFTERNOON AND
CONTINUING THROUGH A GOOD PORTION OF THE NIGHT TONIGHT (ESPECIALLY
THE KEWEENAW TONIGHT). QPF AMOUNTS WILL BE MUCH LIGHTER THAN SEEN
OVER THE LAST COUPLE DAYS AND MAINLY BETWEEN A TRACE AND A COUPLE
TENTHS. IN ADDITION...IT WILL BECOME BREEZY BEHIND THE COLD
FRONT...WITH BUFKIT SOUNDINGS INDICATING GUSTS AROUND 25KTS OVER
MUCH MUCH OF UPPER MICHIGAN TODAY. WITH THE COLD AIR ADVECTION IN
PLACE THROUGH MUCH OF TONIGHT...THOSE GUSTS WILL LIKELY KEEP UP AS
WINDS SHIFT TO THE WEST THROUGH THE NIGHT. WHILE THE KEWEENAW MAY BE
PROTECTED SLIGHTLY TODAY...THE WINDS SHOULD REALLY KICK IN TONIGHT
AS IT IS CLOSEST TO THE TIGHTEST PRESSURE GRADIENT WITH THE
DEPARTING LOW AND RESULTING STRONGER WINDS JUST ABOVE THE SURFACE.
EXPECT THERE TO BE A PERIOD THIS EVENING AND INTO THE EARLY
OVERNIGHT HOURS WHERE GUSTS IN THE KEWEENAW WILL BE BETWEEN
30-35KTS.
FINALLY FOR TEMPERATURES...VALUES THIS MORNING HAVE BEEN CONSISTENT
IN THE 50S OVER THE INTERIOR LOCATIONS...ALTHOUGH LOCATIONS NEAR
THE COOLING OF THE GREAT LAKES HAVE BEEN BOUNCING UP AND DOWN
DEPENDING ON THE WIND DIRECTION. WITH THE WARM START AND THE WARM
FRONT PUSHING NORTHEAST THROUGH MUCH OF UPPER MICHIGAN
TODAY...SHOULD SEE TEMPERATURES RISE INTO THE MID-UPPER 60S OVER
THE CENTRAL/EASTERN CWA AND WHERE SOME SUNSHINE OCCURS WILL
PROBABLY SEE SOME SITES HITTING THE 70 DEGREE MARK. COLDER AIR
ARRIVING BEHIND THE COLD FRONT WILL LEAD TO FALLING TEMPS OVER THE
WEST IN THE AFTERNOON AND THE REST OF THE AREA TOWARDS EVENING. THE
CLOUD COVER TONIGHT WILL KEEP TEMPS A LITTLE ABOVE NORMAL AND HAVE
LOWS IN THE LOWER 40S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 459 AM EDT FRI MAY 9 2014
PATTERN EVOLUTION DURING THE LONG TERM WILL BRING A RETURN OF A
BUILDING RIDGE ALONG/NEAR THE W COAST OF NAMERICA THIS WEEKEND THRU
THE FIRST HALF OF NEXT WEEK (POSITIVE ANOMALIES REACH THEIR MAX
WED). THIS WILL FORCE A FAIRLY DEEP TROF FOR MID MAY TO AMPLIFY
SOUTHWARD INTO THE CNTRL CONUS DURING THE EARLY PART OF NEXT WEEK
WITH SLOW EASTWARD PROGRESSION THEREAFTER. THE BUILDING RIDGE WILL
FORCE THE UPPER LOW/ENERGY NOW IN THE GULF OF ALASKA TO DIVE SE
TOWARD THE SRN ROCKIES. AS THE ENERGY THEN LIFTS NE...ANOTHER ACTIVE
LOW PRES SYSTEM WILL MOVE NE INTO THE UPPER MISSISSIPPI VALLEY ON A
TRACK SIMILAR TO THE SYSTEM CURRENTLY AFFECTING THE MISSISSIPPI
VALLEY/WRN GREAT LAKES. SO...AFTER A PERIOD OF DRY WEATHER EARLY IN
THE WEEKEND...POTENTIAL OF SHRA WILL RETURN...PERHAPS AS EARLY AS
LATE SAT NIGHT/SUN MORNING. DECENT PCPN AMOUNTS MAY THEN BE IN THE
OFFING FOR MON/MON NIGHT AS LOW PRES LIFTS INTO THE UPPER
MISSISSIPPI VALLEY. ONCE THE UPPER TROF REACHES THE WRN GREAT
LAKES...THERE MAY BE A DAY OR 2 OF LIGHT SHOWERY PCPN AT TIMES IN
THE MID WEEK PERIOD (PERHAPS EVEN A LITTLE SNOW MIXED IN). AS FOR
TEMPS...READINGS OVER THE WEEKEND SHOULD BE CLOSE TO NORMAL...
THOUGH IT WILL OBVIOUSLY BE COOL WHERE WINDS ARE ONSHORE NEAR THE
GREAT LAKES. TEMPS WILL BEGIN TO TAKE A DOWNWARD TURN MON/TUE WITH
THE EARLY WEEK LOW PRES SYSTEM...AND TEMPS WED/THU WILL LIKELY BE
QUITE CHILLY/WELL BLO NORMAL FOR MID MAY AS UPPER TROF DRIFTS ACROSS
THE AREA (850MB TEMPS FALL TO PERHAPS AS LOW AS -4 TO -6C). FARTHER
DOWN THE ROAD...PATTERN WILL PROBABALY CONTINUE TO LEAN TOWARD
MAINTAINING OVERALL BLO NORMAL TEMPS OUT TO 10-14 DAYS.
BEGINNING SAT...LOW CLOUDS AND POSSIBLY SOME -SHRA/SPRINKLES/-DZ
WILL LINGER EARLY OVER THE E. OTHERWISE...EXPECT ABUNDANT SUNSHINE
OVER THE W TO SPREAD TO THE ERN FCST AREA BY AFTN AS FCST SOUNDINGS
SHOW A DEEP DRY AIR MASS SPREADING OVER THE AREA. DRY AIR MASS WILL
ALLOW FOR DEEP MIXING. MIXING UPWARDS OF 750MB ON FCST SOUNDINGS
YIELDS MAX TEMPS INTO THE MID TO PERHAPS UPPER 60S IN THE INTERIOR.
TEMPS WILL BE COOLEST ALONG LAKE SUPERIOR IN LOCATIONS WHERE
WESTERLY WINDS HAVE AN OVERLAKE COMPONENT. LAKE BREEZE MAY DEVELOP
NEAR LAKE MICHIGAN IN THE LATTER PART OF THE AFTN. WITH THE DEEP DRY
AIR MASS...RH WILL LIKELY TUMBLE TO AS LOW AS AROUND 20PCT IN THE
INTERIOR...IN PARTICULAR TOWARD THE WI BORDER.
OUT AHEAD OF THE MAIN SYSTEM DIVING TOWARD THE SRN ROCKIES...A LEAD
SHORTWAVE WILL SHIFT FROM THE WRN PLAINS SAT MORNING TO THE UPPER
LAKES SUN MORNING. GIVEN THAT THE SHORTWAVE WILL BE HEADING INTO THE
LARGE SCALE BUILDING UPPER RIDGE DOWNSTREAM OF THE MAIN TROF
AMPLIFYING OVER THE ROCKIES...PCPN ASSOCIATED WITH SHORTWAVE WILL
LIKELY BE DIMINISHING AS IT MOVES INTO THE UPPER LAKES. ANTECEDENT
VERY DRY AIR MASS WILL FURTHER AID THE DIMINISHING OF PCPN SPREADING
INTO THE AREA LATE SAT NIGHT/SUN MORNING. QUESTION WILL BE HOW FAST
DOES THE PCPN DECAY. AT THIS POINT...IT APPEARS THE GFS IS MUCH TOO
AGGRESSIVE WITH WIDESPREAD PCPN IT MOVES ACROSS THE FCST AREA WITH
AS MUCH AS 0.25-0.40 INCHES OVER ROUGHLY THE NW HALF OF UPPER MI.
OTHER GUIDANCE IS DRIER WITH PCPN DRYING UP AS IT MOVES INTO/ACROSS
THE THE FCST AREA. THE NAM IN PARTICULAR HAS ALMOST NO PCPN REACHING
UPPER MI. WILL FAVOR THE DRIER SOLUTIONS GIVEN BUILDING UPPER RIDGE
AND ANTECEDENT DRY AIR MASS. ONLY CHC POPS WILL BE UTILIZED LATE SAT
NIGHT THRU SUN MORNING WITH POPS LOWEST OVER THE NE. CLOUD
COVER/PCPN WILL HAVE AN IMPACT ON HIGH TEMPS SUN. IN FAVORING THE
DRIER SOLUTIONS...WILL ALSO LEAN TOWARD THE WARMER GUIDANCE FOR
HIGHS SUN. AWAY FROM LAKE MODERATION...TEMPS SHOULD REACH WELL INTO
THE 60S TO NEAR 70F.
MAIN SHORTWAVE MOVES OUT ACROSS THE SRN PLAINS MON MORNING AND LIFTS
INTO THE UPPER MISSISSIPPI VALLEY MON NIGHT/TUE ALONG WITH
ASSOCIATED SFC LOW PRES. THERE IS CONSIDERABLE MODEL SPREAD ON
TIMING SYSTEM WITH SOME HINTS OF A SLOWER TREND DEVELOPING. THE
UKMET IS SLOWEST...SHOWING LOW PRES ONLY IN WCNTRL WI AT 00Z WED.
NEXT IS THE GEM...SWINGING FROPA THRU UPPER MI TUE AFTN-TUE NIGHT.
THE ECMWF BRINGS FRONT THRU MON NIGHT/TUE MORNING WHILE THE GFS IS
QUICKEST...PUSHING FRONT ACROSS THE AREA MON EVENING. CONSENSUS OF
RECENT RUNS WILL BE UTILIZED GIVEN SPREAD. AT THIS TIME...BEST
CHANCE OF SHRA SOME TSRA APPEARS TO BE MON/MON NIGHT...BUT IF SLOWER
TREND GAINS MOMENTUM...TIMING WILL NEED TO BE PUSHED BACK A BIT.
AS UPPER TROF DRIFTS ACROSS THE WRN LAKES WED/THU...THERMAL TROF
WITH 850MB TEMPS IN THE -2 TO -6C RANGE WILL YIELD ABUNDANT CLOUD
COVER...ESPECIALLY DURING THE DAYLIGHT HRS. HIGH SUN ANGLE (ONLY 5
1/2 WEEKS TO THE SUMMER SOLSTICE DURING THE MIDDLE OF NEXT WEEK)
WILL PROBABLY SUPPORT AT LEAST SCT -SHRA ACTIVITY...PEAKING IN THE
AFTN HRS. GIVEN THE COLD TEMPS IN THE COLUMN...MAY SEE SOME
GRAUPLE...AND PERHAPS EVEN SOME SNOWFLAKES IF PCPN LINGERS INTO THE
NIGHT. IF WED OR THU ENDS UP MAINLY CLOUDY WITH NMRS -SRHA...HIGH
TEMPS MAY STRUGGLE TO GET INTO THE 50S INLAND WHILE DAYTIME TEMPS
MAY HOLD TO THE MID 30S TO MID 40S NEAR LAKE SUPERIOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 128 AM EDT FRI MAY 9 2014
SHOWERS AND SCT TSRA WILL LIFT TO THE NE THROUGH UPPER MICHIGAN
OVERNIGHT. AS A RESULT...LOW LEVEL MOISTENING FROM THE RAIN AND S TO
SE FLOW WILL KEEP OR DROP CIGS INTO THE IFR/LIFR RANGE TONIGHT.
CONDITIONS WILL IMPROVE FRI MORNING AS WINDS BECOME SW AND GREATER
DRYING/MIXING MOVES IN. A BRIEF PERIOD OF VFR CONDITIONS MAY DEVELOP
BY AFTERNOON BUT LOWER MVFR CIGS ARE EXPECTED TO REDEVELOP OVER THE
WEST AS ADDITIONAL MOISTURE WRAPS AROUND THE DEPARTING LOW PRESSURE
SYSTEM.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 422 AM EDT FRI MAY 9 2014
A LOW PRESSURE SYSTEM NEAR DULUTH EARLY THIS MORNING WILL SLIDE
NORTHEAST INTO ONTARIO TODAY. AS THIS OCCURS...WINDS WILL SHIFT
AROUND TO THE SOUTHWESTERLY DIRECTION TODAY AND THEN TO THE WEST
TONIGHT. EXPECT THE WINDS TO INCREASE FROM WEST TO EAST TODAY AND
GENERALLY TO 25KTS TONIGHT...ALTHOUGH THERE COULD BE SOME GUSTS
TO 30KTS OVER THE CENTRAL LAKE. THESE STRONGER WINDS...COMBINED WITH
GRADUALLY DRYING LOWER LEVELS SHOULD LEAD TO A DIMINISHMENT OF THE
DENSE FOG OVER LAKE SUPERIOR FROM SOUTHWEST TO NORTHEAST TODAY.
OPTED TO EXTENDED THE DENSE FOG ADVISORY FOR LAKE SUPERIOR INTO THE
AFTERNOON HOURS TO BETTER MATCH UP WITH THE INCREASING WINDS AND
DRIER AIR. A HIGH PRESSURE RIDGE WILL THEN SLIDE OVER THE AREA ON
SATURDAY AND LEAD TO WINDS FALLING BELOW 15KTS SATURDAY NIGHT. THESE
LIGHT WINDS WILL REMAIN THROUGH SUNDAY EVENING. A LOW PRESSURE
SYSTEM MOVING TOWARDS THE UPPER GREAT LAKES REGION FROM THE CENTRAL
PLAINS ON SUNDAY NIGHT WILL LEAD TO INCREASING EASTERLY WINDS (TO
25KTS BY MONDAY EVENING). THEN AS THE LOW SHIFTS NORTHEAST INTO
ONTARIO ON TUESDAY...WINDS WILL SHIFT TO THE SOUTHWEST AND STAY
BELOW 20KTS.
&&
.HYDROLOGY...
ISSUED AT 456 AM EDT FRI MAY 9 2014
THE RAIN SHOWERS AND THUNDERSTORMS PRODUCING HEAVY RAIN HAVE
NEARLY DEPARTED UPPER MICHIGAN EARLY THIS MORNING. BUT THEY HAVE
LEFT RISING RIVER LEVELS IN THEIR WAKE...ESPECIALLY OVER WESTERN
UPPER MICHIGAN WHERE THE HEAVIEST RAIN HAS FALLEN. THE KEWEENAW
PENINSULA HAS SEEN AROUND 0.75 INCHES OVERNIGHT IN ADDITION TO THE
INCH OF RAIN THAT FELL LAST NIGHT. THIS AS LED TO ANOTHER RISE OF
THE TRAP ROCK RIVER OVER THE LAST COUPLE OF HOURS. IT HAS LEVELED
OUT SOMEWHAT OVER THE LAST HOUR...BUT WITH A COUPLE HOURS LEFT
OF RAIN AND SNOW MELT CONTINUING WOULD EXPECT A LITTLE MORE RISE
THIS MORNING. IT DID BRIEFLY REACH 10.15FT...WHICH PUTS THE CURRENT
CREST AT THE 4TH HIGHEST ON RECORD.
WARM TEMPERATURES TODAY WILL CONTINUE THE MELTING FROM A FEW INCHES
OF SNOW WATER EQUIVALENT SHOWN FROM NOHRSC MODEL FROM THE
TIP OF THE KEWEENAW PENINSULA THROUGH PAINESDALE...DONKEN...AND
WINONA. THIS LINES UP WELL WITH THE LATEST SNOW DEPTHS REPORTED AT
PAINESDALE AND HERMAN. WILL SEE HOW THIS SNOW MELT /WARMER FCST
TEMPS FOR THE REST OF THIS WEEK/ IMPACT DOWNSTREAM RIVERS INCLUDING
THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES AND THE TRAP ROCK
RIVER. MOST IF NOT ALL OF THE SNOW COULD MELT BY THIS
WEEKEND...BUT IT WILL KEEP THE RIVER LEVELS HIGH INTO EARLY NEXT
WEEK. IN ADDITION...WIDESPREAD RAIN IS EXPECTED AGAIN ON
MONDAY AND THE CURRENT FORECAST CALLS FOR AROUND A HALF AN INCH
OF ACCUMULATION. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS
SHOULD CONTINUE TO MONITOR RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 5 PM EDT /4 PM CDT/ THIS AFTERNOON FOR
LSZ162-240>251-263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...JLB
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
457 AM EDT FRI MAY 9 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 444 AM EDT FRI MAY 9 2014
THE UPPER TROUGH THAT HAS BEEN CONTROLLING OUR WEATHER FOR THE LAST
COUPLE OF DAYS IS CURRENTLY MOVING NORTHEAST THROUGH THE CENTRAL
PLAINS. MOISTURE LADEN AIR STREAMING NORTHEAST AHEAD OF THIS TROUGH
CAN BE SEEN ON WV IMAGERY EARLY THIS MORNING...WHICH IS HELPING TO
FUEL SHOWERS AND ISOLATED THUNDERSTORMS FROM WESTERN LAKE SUPERIOR
THROUGH PORTIONS OF UPPER MICHIGAN...AND SOUTHEAST TO EASTERN
WISCONSIN. AT THE SURFACE...A 998MB LOW IS LOCATED JUST SOUTHWEST OF
DULUTH AND A WARM FRONT STRETCHES EAST ALONG THE U.P. AND
WISCONSIN BORDER. SHORTWAVES EMBEDDED WITHIN THE WARM MOIST
SOUTHWESTERLY FLOW CONTINUES TO PRODUCE AREAS OF THUNDERSTORMS OVER
THE WESTERN HALF OF THE GREAT LAKES REGION AND EXPECT THAT TO
CONTINUE FOR AREAS WITHIN THE WARM/MOIST AIRMASS.
AS THE LOW LIFTS NORTHEAST TODAY...THE COLD FRONT (CURRENTLY
STRETCHING SOUTH FROM SOUTHEAST MINNESOTA THROUGH NORTHERN
MISSOURI) WILL SWEEP NORTHEAST ACROSS THE UPPER GREAT LAKES REGION.
WITH THE SHOWER/THUNDERSTORM COVERAGE STARTING TO BECOME MORE
SCATTERED/ISOLATED...WILL FOLLOW THAT IDEA FOR POPS AHEAD OF THE
COLD FRONT. ALREADY STARTING TO SEE THE AFFECT OF THE DRYING ALOFT
OVER NORTHWEST WISCONSIN AND EXPECT THE LAST AREAS OF SHOWERS FOR
THIS MORNING TO PUSH THROUGH WESTERN UPPER MICHIGAN OVER THE NEXT
COUPLE OF HOURS. AS THAT DRYING SHIFTS EAST THIS MORNING...WILL
DIMINISH POPS FROM WEST TO EAST DURING THE MORNING HOURS. WITH
THERE STILL BEING SOME ISOLATED THUNDER ON THE BACK EDGE OF THE
PRECIPITATION (EVEN THOUGH RAP ANALYSIS OF MUCAPE AND MID-LEVEL
LAPSE RATE VALUES ARE VERY WEAK)...HAVE EXTENDED THE SLIGHT
CHANCE OF THUNDER A LITTLE LONGER OVER THE EAST THIS MORNING TO
COINCIDE WITH THE AXIS OF MOISTURE AND LATEST THUNDER
AREAS.
BEHIND THE COLD FRONT...MAY SEE A FEW PEAKS OF SUNSHINE OVER THE
CENTRAL/EAST (WHERE FOG ISN/T OCCURRING) AS THIS MID LEVEL DRY SLOT
MOVES THROUGH AND BEFORE THE NEXT WAVE OF LOW LEVEL MOISTURE AND
PRECIPITATION (CURRENTLY IN THE EASTERN DAKOTAS AND WESTERN
MINNESOTA) MOVES OVER THE AREA. WILL CONTINUE THE IDEA SHOWN IN THE
PREVIOUS FORECAST OF ISOLATED TO SCATTERED SHOWERS MOVING OVER THE
WEST OR NORTHWEST HALF OF THE CWA LATER THIS AFTERNOON AND
CONTINUING THROUGH A GOOD PORTION OF THE NIGHT TONIGHT (ESPECIALLY
THE KEWEENAW TONIGHT). QPF AMOUNTS WILL BE MUCH LIGHTER THAN SEEN
OVER THE LAST COUPLE DAYS AND MAINLY BETWEEN A TRACE AND A COUPLE
TENTHS. IN ADDITION...IT WILL BECOME BREEZY BEHIND THE COLD
FRONT...WITH BUFKIT SOUNDINGS INDICATING GUSTS AROUND 25KTS OVER
MUCH MUCH OF UPPER MICHIGAN TODAY. WITH THE COLD AIR ADVECTION IN
PLACE THROUGH MUCH OF TONIGHT...THOSE GUSTS WILL LIKELY KEEP UP AS
WINDS SHIFT TO THE WEST THROUGH THE NIGHT. WHILE THE KEWEENAW MAY BE
PROTECTED SLIGHTLY TODAY...THE WINDS SHOULD REALLY KICK IN TONIGHT
AS IT IS CLOSEST TO THE TIGHTEST PRESSURE GRADIENT WITH THE
DEPARTING LOW AND RESULTING STRONGER WINDS JUST ABOVE THE SURFACE.
EXPECT THERE TO BE A PERIOD THIS EVENING AND INTO THE EARLY
OVERNIGHT HOURS WHERE GUSTS IN THE KEWEENAW WILL BE BETWEEN
30-35KTS.
FINALLY FOR TEMPERATURES...VALUES THIS MORNING HAVE BEEN CONSISTENT
IN THE 50S OVER THE INTERIOR LOCATIONS...ALTHOUGH LOCATIONS NEAR
THE COOLING OF THE GREAT LAKES HAVE BEEN BOUNCING UP AND DOWN
DEPENDING ON THE WIND DIRECTION. WITH THE WARM START AND THE WARM
FRONT PUSHING NORTHEAST THROUGH MUCH OF UPPER MICHIGAN
TODAY...SHOULD SEE TEMPERATURES RISE INTO THE MID-UPPER 60S OVER
THE CENTRAL/EASTERN CWA AND WHERE SOME SUNSHINE OCCURS WILL
PROBABLY SEE SOME SITES HITTING THE 70 DEGREE MARK. COLDER AIR
ARRIVING BEHIND THE COLD FRONT WILL LEAD TO FALLING TEMPS OVER THE
WEST IN THE AFTERNOON AND THE REST OF THE AREA TOWARDS EVENING. THE
CLOUD COVER TONIGHT WILL KEEP TEMPS A LITTLE ABOVE NORMAL AND HAVE
LOWS IN THE LOWER 40S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 431 PM EDT THU MAY 8 2014
A SOMEWHAT PROGRESSIVE PATTERN IN THE LONG TERM WILL KEEP THE
OVERALL PERIOD DAMP WITH TEMPS AROUND AVERAGE THIS WEEKEND AND
SLIGHTLY BELOW AVERAGE NEXT WEEK.
A WEAK BLOCKING SETUP OVER THE CENTRAL CONUS TODAY WILL BEGIN
BREAKING DOWN OVERNIGHT AS A STRONG SHORTWAVE TROUGH EJECTS
NORTHEASTWARD OUT OF THE CENTRAL PLAINS. THIS TROUGH WILL PUSH
EASTWARD INTO A SHARP RIDGE EXTENDING NORTHWARD OVER HUDSON BAY.
DEEP TROUGHING DEVELOPING OVER THE GULF OF ALASKA TODAY WILL THEN
TRACK TO THE SOUTHERN ROCKIES BY SUNDAY NIGHT AND SETUP A PATTERN
FAIRLY SIMILAR TO THE PAST COUPLE DAYS...WITH DEEP TROUGHING OVER
CENTRAL NORTH AMERICA AND A RIDGE BUILDING ACROSS THE EASTERN CONUS.
THE TROUGH WILL SHIFT NORTHEASTWARD EARLY NEXT WEEK...WITH BROAD
TROUGHING DEVELOPING OVER THE GREAT LAKES REGION BY MID-WEEK.
FRIDAY NIGHT...THE TROUGH AXIS APPROACHING THE AREA TODAY WILL CROSS
OVER THE CWA BETWEEN 15 AND 21Z FRIDAY. HOWEVER...A REINFORCING
TROUGH ROTATING AROUND A CLOSED MID-LEVEL LOW OVER NORTHERN
SASKATCHEWAN WILL TRACK IN BEHIND THIS LEADING TROUGH AXIS AND
CONTINUE CHANCES FOR PRECIP THROUGH MUCH OF FRIDAY NIGHT. MOISTURE
AVAILABILITY LESSENS BY THIS TIME...SO DO NOT EXPECT ANYTHING MORE
THAN SOME SCATTERED LIGHT SHOWERS SHIFTING FROM WEST TO EAST FRIDAY
NIGHT.
SATURDAY LOOKS TO BE THE ONLY TRUE DRY DAY IN THE EXTENDED FORECAST
WITH A WEAK MID-LEVEL RIDGE BUILDING ACROSS THE UPPER MS VALLEY. A
PUSH OF 0 TO 2C H8 TEMPS BEHIND FRIDAYS SYSTEM WILL LEAD TO A COOLER
DAY THAN FRIDAY...BUT SUBSTANTIAL DRY AIR THROUGH THE COLUMN WILL
RESULT IN MOSTLY SUNNY SKIES WITH SOME AFTERNOON CUMULUS AWAY FROM
THE GREAT LAKES. HIGHS SHOULD MAKE IT TO THE LOW 60S INLAND...BUT
STRUGGLE TO REACH 50 VERY NEAR SHORELINE LOCATIONS DOWNWIND OF LAKE
SUPERIOR WITH WESTERLY FLOW. AS FOR FIRE WX CONCERNS...TEMPS WILL BE
AT OR SLIGHTLY ABOVE AVERAGE WITH MIN RH VALUES IN THE MID 20S TO
LOW 30S ACROSS MUCH OF THE INTERIOR...AND WINDS GUSTING TO AROUND
20MPH.
SATURDAY NIGHT AND SUNDAY...A DECAYING TROUGH AXIS ENTERING THE
RIDGE OVER A WEAK SFC WARM FRONT TRACKING IN FROM THE SW WILL YIELD
SOME SCATTERED RAIN SHOWERS ACROSS MAINLY THE WESTERN AND CENTRAL
CWA. THIS WILL KEEP SKIES MOSTLY CLOUDY THROUGH SUNDAY. THE FRONT
LOOKS TO STALL ALONG LAKE SUPERIOR...SO QUITE A CONTRAST IN TEMPS
WILL BE POSSIBLE AS THE KEWEENAW AND EASTERN CWA REMAIN IN THE UPPER
40S TO MID 50S IN SE FLOW WHILE THE INTERIOR WEST SEES TEMPS IN THE
MID TO UPPER 60S UNDER WITH SW FLOW.
SUNDAY NIGHT THROUGH TUESDAY...THE DEVELOPING TROUGH ACROSS THE
PLAINS WILL BEGIN SHIFTING EASTWARD ACROSS THE MID AND UPPER MS
VALLEY SUNDAY NIGHT. THIS WILL BRING SCATTERED TO NUMEROUS SHOWERS
AND SOME EMBEDDED THUNDERSTORMS ACROSS THE AREA. HOWEVER...TIMING
AND OVERALL COVERAGE IS STILL IN QUESTION AS THE GFS IS SOMEWHAT
MORE PROGRESSIVE WITH THE TROUGH COMPARED TO THE ECMWF AND THE GEM.
WITH THAT SAID...THE BEST CHANCE FOR INCREASED COVERAGE AND HEAVIER
SHOWERS/STORMS SHOULD BE MONDAY AFTERNOON THROUGH TUESDAY.
WEDNESDAY AND THURSDAY...PERSISTENT CYCLONIC FLOW WILL CONTINUE OVER
THE REGION AS THE TROUGH STALLS OVER HUDSON BAY AND NORTHERN
ONTARIO. WITH N TO NW FLOW...CLOUD COVER...AND H8 TEMPS OF -4 TO
-8C...TEMPS WILL STRUGGLE TO GET OUT OF THE 40S ACROSS THE NORTH
HALF AND THE LOW 50S FOR THE SOUTH HALF.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 128 AM EDT FRI MAY 9 2014
SHOWERS AND SCT TSRA WILL LIFT TO THE NE THROUGH UPPER MICHIGAN
OVERNIGHT. AS A RESULT...LOW LEVEL MOISTENING FROM THE RAIN AND S TO
SE FLOW WILL KEEP OR DROP CIGS INTO THE IFR/LIFR RANGE TONIGHT.
CONDITIONS WILL IMPROVE FRI MORNING AS WINDS BECOME SW AND GREATER
DRYING/MIXING MOVES IN. A BRIEF PERIOD OF VFR CONDITIONS MAY DEVELOP
BY AFTERNOON BUT LOWER MVFR CIGS ARE EXPECTED TO REDEVELOP OVER THE
WEST AS ADDITIONAL MOISTURE WRAPS AROUND THE DEPARTING LOW PRESSURE
SYSTEM.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 422 AM EDT FRI MAY 9 2014
A LOW PRESSURE SYSTEM NEAR DULUTH EARLY THIS MORNING WILL SLIDE
NORTHEAST INTO ONTARIO TODAY. AS THIS OCCURS...WINDS WILL SHIFT
AROUND TO THE SOUTHWESTERLY DIRECTION TODAY AND THEN TO THE WEST
TONIGHT. EXPECT THE WINDS TO INCREASE FROM WEST TO EAST TODAY AND
GENERALLY TO 25KTS TONIGHT...ALTHOUGH THERE COULD BE SOME GUSTS
TO 30KTS OVER THE CENTRAL LAKE. THESE STRONGER WINDS...COMBINED WITH
GRADUALLY DRYING LOWER LEVELS SHOULD LEAD TO A DIMINISHMENT OF THE
DENSE FOG OVER LAKE SUPERIOR FROM SOUTHWEST TO NORTHEAST TODAY.
OPTED TO EXTENDED THE DENSE FOG ADVISORY FOR LAKE SUPERIOR INTO THE
AFTERNOON HOURS TO BETTER MATCH UP WITH THE INCREASING WINDS AND
DRIER AIR. A HIGH PRESSURE RIDGE WILL THEN SLIDE OVER THE AREA ON
SATURDAY AND LEAD TO WINDS FALLING BELOW 15KTS SATURDAY NIGHT. THESE
LIGHT WINDS WILL REMAIN THROUGH SUNDAY EVENING. A LOW PRESSURE
SYSTEM MOVING TOWARDS THE UPPER GREAT LAKES REGION FROM THE CENTRAL
PLAINS ON SUNDAY NIGHT WILL LEAD TO INCREASING EASTERLY WINDS (TO
25KTS BY MONDAY EVENING). THEN AS THE LOW SHIFTS NORTHEAST INTO
ONTARIO ON TUESDAY...WINDS WILL SHIFT TO THE SOUTHWEST AND STAY
BELOW 20KTS.
&&
.HYDROLOGY...
ISSUED AT 456 AM EDT FRI MAY 9 2014
THE RAIN SHOWERS AND THUNDERSTORMS PRODUCING HEAVY RAIN HAVE
NEARLY DEPARTED UPPER MICHIGAN EARLY THIS MORNING. BUT THEY HAVE
LEFT RISING RIVER LEVELS IN THEIR WAKE...ESPECIALLY OVER WESTERN
UPPER MICHIGAN WHERE THE HEAVIEST RAIN HAS FALLEN. THE KEWEENAW
PENINSULA HAS SEEN AROUND 0.75 INCHES OVERNIGHT IN ADDITION TO THE
INCH OF RAIN THAT FELL LAST NIGHT. THIS AS LED TO ANOTHER RISE OF
THE TRAP ROCK RIVER OVER THE LAST COUPLE OF HOURS. IT HAS LEVELED
OUT SOMEWHAT OVER THE LAST HOUR...BUT WITH A COUPLE HOURS LEFT
OF RAIN AND SNOW MELT CONTINUING WOULD EXPECT A LITTLE MORE RISE
THIS MORNING. IT DID BRIEFLY REACH 10.15FT...WHICH PUTS THE CURRENT
CREST AT THE 4TH HIGHEST ON RECORD.
WARM TEMPERATURES TODAY WILL CONTINUE THE MELTING FROM A FEW INCHES
OF SNOW WATER EQUIVALENT SHOWN FROM NOHRSC MODEL FROM THE
TIP OF THE KEWEENAW PENINSULA THROUGH PAINESDALE...DONKEN...AND
WINONA. THIS LINES UP WELL WITH THE LATEST SNOW DEPTHS REPORTED AT
PAINESDALE AND HERMAN. WILL SEE HOW THIS SNOW MELT /WARMER FCST
TEMPS FOR THE REST OF THIS WEEK/ IMPACT DOWNSTREAM RIVERS INCLUDING
THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES AND THE TRAP ROCK
RIVER. MOST IF NOT ALL OF THE SNOW COULD MELT BY THIS
WEEKEND...BUT IT WILL KEEP THE RIVER LEVELS HIGH INTO EARLY NEXT
WEEK. IN ADDITION...WIDESPREAD RAIN IS EXPECTED AGAIN ON
MONDAY AND THE CURRENT FORECAST CALLS FOR AROUND A HALF AN INCH
OF ACCUMULATION. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS
SHOULD CONTINUE TO MONITOR RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 5 PM EDT /4 PM CDT/ THIS AFTERNOON FOR
LSZ162-240>251-263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KLUBER
AVIATION...JLB
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
445 AM EDT FRI MAY 9 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 444 AM EDT FRI MAY 9 2014
THE UPPER TROUGH THAT HAS BEEN CONTROLLING OUR WEATHER FOR THE LAST
COUPLE OF DAYS IS CURRENTLY MOVING NORTHEAST THROUGH THE CENTRAL
PLAINS. MOISTURE LADEN AIR STREAMING NORTHEAST AHEAD OF THIS TROUGH
CAN BE SEEN ON WV IMAGERY EARLY THIS MORNING...WHICH IS HELPING TO
FUEL SHOWERS AND ISOLATED THUNDERSTORMS FROM WESTERN LAKE SUPERIOR
THROUGH PORTIONS OF UPPER MICHIGAN...AND SOUTHEAST TO EASTERN
WISCONSIN. AT THE SURFACE...A 998MB LOW IS LOCATED JUST SOUTHWEST OF
DULUTH AND A WARM FRONT STRETCHES EAST ALONG THE U.P. AND
WISCONSIN BORDER. SHORTWAVES EMBEDDED WITHIN THE WARM MOIST
SOUTHWESTERLY FLOW CONTINUES TO PRODUCE AREAS OF THUNDERSTORMS OVER
THE WESTERN HALF OF THE GREAT LAKES REGION AND EXPECT THAT TO
CONTINUE FOR AREAS WITHIN THE WARM/MOIST AIRMASS.
AS THE LOW LIFTS NORTHEAST TODAY...THE COLD FRONT (CURRENTLY
STRETCHING SOUTH FROM SOUTHEAST MINNESOTA THROUGH NORTHERN
MISSOURI) WILL SWEEP NORTHEAST ACROSS THE UPPER GREAT LAKES REGION.
WITH THE SHOWER/THUNDERSTORM COVERAGE STARTING TO BECOME MORE
SCATTERED/ISOLATED...WILL FOLLOW THAT IDEA FOR POPS AHEAD OF THE
COLD FRONT. ALREADY STARTING TO SEE THE AFFECT OF THE DRYING ALOFT
OVER NORTHWEST WISCONSIN AND EXPECT THE LAST AREAS OF SHOWERS FOR
THIS MORNING TO PUSH THROUGH WESTERN UPPER MICHIGAN OVER THE NEXT
COUPLE OF HOURS. AS THAT DRYING SHIFTS EAST THIS MORNING...WILL
DIMINISH POPS FROM WEST TO EAST DURING THE MORNING HOURS. WITH
THERE STILL BEING SOME ISOLATED THUNDER ON THE BACK EDGE OF THE
PRECIPITATION (EVEN THOUGH RAP ANALYSIS OF MUCAPE AND MID-LEVEL
LAPSE RATE VALUES ARE VERY WEAK)...HAVE EXTENDED THE SLIGHT
CHANCE OF THUNDER A LITTLE LONGER OVER THE EAST THIS MORNING TO
COINCIDE WITH THE AXIS OF MOISTURE AND LATEST THUNDER
AREAS.
BEHIND THE COLD FRONT...MAY SEE A FEW PEAKS OF SUNSHINE OVER THE
CENTRAL/EAST (WHERE FOG ISN/T OCCURRING) AS THIS MID LEVEL DRY SLOT
MOVES THROUGH AND BEFORE THE NEXT WAVE OF LOW LEVEL MOISTURE AND
PRECIPITATION (CURRENTLY IN THE EASTERN DAKOTAS AND WESTERN
MINNESOTA) MOVES OVER THE AREA. WILL CONTINUE THE IDEA SHOWN IN THE
PREVIOUS FORECAST OF ISOLATED TO SCATTERED SHOWERS MOVING OVER THE
WEST OR NORTHWEST HALF OF THE CWA LATER THIS AFTERNOON AND
CONTINUING THROUGH A GOOD PORTION OF THE NIGHT TONIGHT (ESPECIALLY
THE KEWEENAW TONIGHT). QPF AMOUNTS WILL BE MUCH LIGHTER THAN SEEN
OVER THE LAST COUPLE DAYS AND MAINLY BETWEEN A TRACE AND A COUPLE
TENTHS. IN ADDITION...IT WILL BECOME BREEZY BEHIND THE COLD
FRONT...WITH BUFKIT SOUNDINGS INDICATING GUSTS AROUND 25KTS OVER
MUCH MUCH OF UPPER MICHIGAN TODAY. WITH THE COLD AIR ADVECTION IN
PLACE THROUGH MUCH OF TONIGHT...THOSE GUSTS WILL LIKELY KEEP UP AS
WINDS SHIFT TO THE WEST THROUGH THE NIGHT. WHILE THE KEWEENAW MAY BE
PROTECTED SLIGHTLY TODAY...THE WINDS SHOULD REALLY KICK IN TONIGHT
AS IT IS CLOSEST TO THE TIGHTEST PRESSURE GRADIENT WITH THE
DEPARTING LOW AND RESULTING STRONGER WINDS JUST ABOVE THE SURFACE.
EXPECT THERE TO BE A PERIOD THIS EVENING AND INTO THE EARLY
OVERNIGHT HOURS WHERE GUSTS IN THE KEWEENAW WILL BE BETWEEN
30-35KTS.
FINALLY FOR TEMPERATURES...VALUES THIS MORNING HAVE BEEN CONSISTENT
IN THE 50S OVER THE INTERIOR LOCATIONS...ALTHOUGH LOCATIONS NEAR
THE COOLING OF THE GREAT LAKES HAVE BEEN BOUNCING UP AND DOWN
DEPENDING ON THE WIND DIRECTION. WITH THE WARM START AND THE WARM
FRONT PUSHING NORTHEAST THROUGH MUCH OF UPPER MICHIGAN
TODAY...SHOULD SEE TEMPERATURES RISE INTO THE MID-UPPER 60S OVER
THE CENTRAL/EASTERN CWA AND WHERE SOME SUNSHINE OCCURS WILL
PROBABLY SEE SOME SITES HITTING THE 70 DEGREE MARK. COLDER AIR
ARRIVING BEHIND THE COLD FRONT WILL LEAD TO FALLING TEMPS OVER THE
WEST IN THE AFTERNOON AND THE REST OF THE AREA TOWARDS EVENING. THE
CLOUD COVER TONIGHT WILL KEEP TEMPS A LITTLE ABOVE NORMAL AND HAVE
LOWS IN THE LOWER 40S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 431 PM EDT THU MAY 8 2014
A SOMEWHAT PROGRESSIVE PATTERN IN THE LONG TERM WILL KEEP THE
OVERALL PERIOD DAMP WITH TEMPS AROUND AVERAGE THIS WEEKEND AND
SLIGHTLY BELOW AVERAGE NEXT WEEK.
A WEAK BLOCKING SETUP OVER THE CENTRAL CONUS TODAY WILL BEGIN
BREAKING DOWN OVERNIGHT AS A STRONG SHORTWAVE TROUGH EJECTS
NORTHEASTWARD OUT OF THE CENTRAL PLAINS. THIS TROUGH WILL PUSH
EASTWARD INTO A SHARP RIDGE EXTENDING NORTHWARD OVER HUDSON BAY.
DEEP TROUGHING DEVELOPING OVER THE GULF OF ALASKA TODAY WILL THEN
TRACK TO THE SOUTHERN ROCKIES BY SUNDAY NIGHT AND SETUP A PATTERN
FAIRLY SIMILAR TO THE PAST COUPLE DAYS...WITH DEEP TROUGHING OVER
CENTRAL NORTH AMERICA AND A RIDGE BUILDING ACROSS THE EASTERN CONUS.
THE TROUGH WILL SHIFT NORTHEASTWARD EARLY NEXT WEEK...WITH BROAD
TROUGHING DEVELOPING OVER THE GREAT LAKES REGION BY MID-WEEK.
FRIDAY NIGHT...THE TROUGH AXIS APPROACHING THE AREA TODAY WILL CROSS
OVER THE CWA BETWEEN 15 AND 21Z FRIDAY. HOWEVER...A REINFORCING
TROUGH ROTATING AROUND A CLOSED MID-LEVEL LOW OVER NORTHERN
SASKATCHEWAN WILL TRACK IN BEHIND THIS LEADING TROUGH AXIS AND
CONTINUE CHANCES FOR PRECIP THROUGH MUCH OF FRIDAY NIGHT. MOISTURE
AVAILABILITY LESSENS BY THIS TIME...SO DO NOT EXPECT ANYTHING MORE
THAN SOME SCATTERED LIGHT SHOWERS SHIFTING FROM WEST TO EAST FRIDAY
NIGHT.
SATURDAY LOOKS TO BE THE ONLY TRUE DRY DAY IN THE EXTENDED FORECAST
WITH A WEAK MID-LEVEL RIDGE BUILDING ACROSS THE UPPER MS VALLEY. A
PUSH OF 0 TO 2C H8 TEMPS BEHIND FRIDAYS SYSTEM WILL LEAD TO A COOLER
DAY THAN FRIDAY...BUT SUBSTANTIAL DRY AIR THROUGH THE COLUMN WILL
RESULT IN MOSTLY SUNNY SKIES WITH SOME AFTERNOON CUMULUS AWAY FROM
THE GREAT LAKES. HIGHS SHOULD MAKE IT TO THE LOW 60S INLAND...BUT
STRUGGLE TO REACH 50 VERY NEAR SHORELINE LOCATIONS DOWNWIND OF LAKE
SUPERIOR WITH WESTERLY FLOW. AS FOR FIRE WX CONCERNS...TEMPS WILL BE
AT OR SLIGHTLY ABOVE AVERAGE WITH MIN RH VALUES IN THE MID 20S TO
LOW 30S ACROSS MUCH OF THE INTERIOR...AND WINDS GUSTING TO AROUND
20MPH.
SATURDAY NIGHT AND SUNDAY...A DECAYING TROUGH AXIS ENTERING THE
RIDGE OVER A WEAK SFC WARM FRONT TRACKING IN FROM THE SW WILL YIELD
SOME SCATTERED RAIN SHOWERS ACROSS MAINLY THE WESTERN AND CENTRAL
CWA. THIS WILL KEEP SKIES MOSTLY CLOUDY THROUGH SUNDAY. THE FRONT
LOOKS TO STALL ALONG LAKE SUPERIOR...SO QUITE A CONTRAST IN TEMPS
WILL BE POSSIBLE AS THE KEWEENAW AND EASTERN CWA REMAIN IN THE UPPER
40S TO MID 50S IN SE FLOW WHILE THE INTERIOR WEST SEES TEMPS IN THE
MID TO UPPER 60S UNDER WITH SW FLOW.
SUNDAY NIGHT THROUGH TUESDAY...THE DEVELOPING TROUGH ACROSS THE
PLAINS WILL BEGIN SHIFTING EASTWARD ACROSS THE MID AND UPPER MS
VALLEY SUNDAY NIGHT. THIS WILL BRING SCATTERED TO NUMEROUS SHOWERS
AND SOME EMBEDDED THUNDERSTORMS ACROSS THE AREA. HOWEVER...TIMING
AND OVERALL COVERAGE IS STILL IN QUESTION AS THE GFS IS SOMEWHAT
MORE PROGRESSIVE WITH THE TROUGH COMPARED TO THE ECMWF AND THE GEM.
WITH THAT SAID...THE BEST CHANCE FOR INCREASED COVERAGE AND HEAVIER
SHOWERS/STORMS SHOULD BE MONDAY AFTERNOON THROUGH TUESDAY.
WEDNESDAY AND THURSDAY...PERSISTENT CYCLONIC FLOW WILL CONTINUE OVER
THE REGION AS THE TROUGH STALLS OVER HUDSON BAY AND NORTHERN
ONTARIO. WITH N TO NW FLOW...CLOUD COVER...AND H8 TEMPS OF -4 TO
-8C...TEMPS WILL STRUGGLE TO GET OUT OF THE 40S ACROSS THE NORTH
HALF AND THE LOW 50S FOR THE SOUTH HALF.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 128 AM EDT FRI MAY 9 2014
SHOWERS AND SCT TSRA WILL LIFT TO THE NE THROUGH UPPER MICHIGAN
OVERNIGHT. AS A RESULT...LOW LEVEL MOISTENING FROM THE RAIN AND S TO
SE FLOW WILL KEEP OR DROP CIGS INTO THE IFR/LIFR RANGE TONIGHT.
CONDITIONS WILL IMPROVE FRI MORNING AS WINDS BECOME SW AND GREATER
DRYING/MIXING MOVES IN. A BRIEF PERIOD OF VFR CONDITIONS MAY DEVELOP
BY AFTERNOON BUT LOWER MVFR CIGS ARE EXPECTED TO REDEVELOP OVER THE
WEST AS ADDITIONAL MOISTURE WRAPS AROUND THE DEPARTING LOW PRESSURE
SYSTEM.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 422 AM EDT FRI MAY 9 2014
A LOW PRESSURE SYSTEM NEAR DULUTH EARLY THIS MORNING WILL SLIDE
NORTHEAST INTO ONTARIO TODAY. AS THIS OCCURS...WINDS WILL SHIFT
AROUND TO THE SOUTHWESTERLY DIRECTION TODAY AND THEN TO THE WEST
TONIGHT. EXPECT THE WINDS TO INCREASE FROM WEST TO EAST TODAY AND
GENERALLY TO 25KTS TONIGHT...ALTHOUGH THERE COULD BE SOME GUSTS
TO 30KTS OVER THE CENTRAL LAKE. THESE STRONGER WINDS...COMBINED WITH
GRADUALLY DRYING LOWER LEVELS SHOULD LEAD TO A DIMINISHMENT OF THE
DENSE FOG OVER LAKE SUPERIOR FROM SOUTHWEST TO NORTHEAST TODAY.
OPTED TO EXTENDED THE DENSE FOG ADVISORY FOR LAKE SUPERIOR INTO THE
AFTERNOON HOURS TO BETTER MATCH UP WITH THE INCREASING WINDS AND
DRIER AIR. A HIGH PRESSURE RIDGE WILL THEN SLIDE OVER THE AREA ON
SATURDAY AND LEAD TO WINDS FALLING BELOW 15KTS SATURDAY NIGHT. THESE
LIGHT WINDS WILL REMAIN THROUGH SUNDAY EVENING. A LOW PRESSURE
SYSTEM MOVING TOWARDS THE UPPER GREAT LAKES REGION FROM THE CENTRAL
PLAINS ON SUNDAY NIGHT WILL LEAD TO INCREASING EASTERLY WINDS (TO
25KTS BY MONDAY EVENING). THEN AS THE LOW SHIFTS NORTHEAST INTO
ONTARIO ON TUESDAY...WINDS WILL SHIFT TO THE SOUTHWEST AND STAY
BELOW 20KTS.
&&
.HYDROLOGY...
ISSUED AT 431 PM EDT THU MAY 8 2014
WET WEATHER WILL RETURN INTO FRIDAY NIGHT...THEN RETURN AGAIN BY
EARLY NEXT WEEK. MOST OF THE RAIN LOOKS TO FALL OVER THE STURGEON
RIVER BASIN THIS EVENING. ADDING TO THIS WILL BE SOME MELTING FROM A
FEW INCHES OF SNOW WATER EQUIVALENT SHOWN FROM NOHRSC MODEL FROM THE
TIP OF THE KEWEENAW PENINSULA THROUGH PAINESDALE...DONKEN...AND
WINONA. THIS LINES UP WELL WITH THE LATEST SNOW DEPTHS REPORTED AT
PAINESDALE AND HERMAN. WILL SEE HOW THIS SNOW MELT /WARMER FCST
TEMPS FOR THE REST OF THIS WEEK/ IMPACT DOWNSTREAM RIVERS INCLUDING
THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES AND THE TRAP ROCK
RIVER. MOST IF NOT ALL OF THE SNOW COULD MELT BY THIS WEEKEND.
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS WILL AFFECT THE AREA
INTO EARLY FRIDAY. RAINFALL AMOUNTS WILL LIKELY EXCEED A HALF OF AN
INCH FOR MUCH OF WESTERN UPPER MICHIGAN...AND LOCALIZED AMOUNTS OVER
AN INCH SHOULD OCCUR WHERE THUNDERSTORMS TRACK. THIS WILL KEEP THE
RIVER LEVELS HIGH INTO EARLY NEXT WEEK. THOSE LIVING AROUND
RIVERS...CREEKS...AND STREAMS SHOULD CONTINUE TO MONITOR RIVER
LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 5 PM EDT /4 PM CDT/ THIS AFTERNOON FOR
LSZ162-240>251-263>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KLUBER
AVIATION...JLB
MARINE...SRF
HYDROLOGY...KLUBER
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
340 AM CDT FRI MAY 9 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT FRI MAY 9 2014
RAP ANALYZED SURFACE LOW JUST SOUTH OF DULUTH EARLY THIS MORNING.
AREAS WEST OF THE METRO HAVE SEEN THE WINDS TURN WESTERLY AND PICK
UP IN INTENSITY. COLD AIR ADVECTION IS ONGOING IN THESE AREAS...AND
WILL CONTINUE TO SPREAD ACROSS THE REMAINDER OF THE FORECAST AREA
TODAY. THE SURFACE LOW WILL SLOWLY CONTINUE NORTHEASTWARD...AS THE
WESTERLY WINDS TAKE MUCH OF THE DAY TO SPREAD ACROSS WEST CENTRAL
WISCONSIN. ABUNDANT LOW LEVEL MOISTURE WILL ALLOW FOR LOW LCL
HEIGHTS WHICH IS CURRENTLY NOTICEABLE IN THE OBSERVATIONS BEHIND THE
COLD FRONT WHERE CEILINGS UNDER 1K FEET ARE PRESENT. RAP AND NAM
MODEL SOUNDINGS INDICATE THIS MOISTURE STICKING AROUND FOR MUCH OF
THE DAY...SO TRENDED TOWARD A MORE PESSIMISTIC SKY COVER FORECAST
AND HENCE LOWERED MAX TEMPERATURES TODAY BY A FEW DEGREES ACROSS THE
FA. MAX TEMPS WILL BE ABOUT 10 DEGREES BELOW SEASONAL NORMALS FOR
THIS TIME OF YEAR. IN ADDITION...WRAP AROUND LIGHT RAIN SHOWERS ARE
EXPECTED TO MOVE ACROSS THE NORTHERN PORTION OF THE CWA AS THEY
CYCLONIC CIRCULATION ALOFT REMAINS BETTER TOWARD THE NORTH /AS WELL
AS AT LEAST SOME FGEN AND FN VECTOR CONVERGENCE/. SKIES WILL BEGIN
CLEARING LATE THIS AFTERNOON AND MOSTLY CLEAR SKIES ARE EXPECTED
OVERNIGHT...EXCEPT CLOUDS WILL QUICKLY BEGIN FILLING IN FROM THE
SOUTHWEST EARLY SATURDAY MORNING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 340 AM CDT FRI MAY 9 2014
AN UNSETTLED PERIOD REMAINS FORECAST FOR MUCH OF THE LONGER TERM
AS NORTHERN AND SOUTHERN STREAM ENERGY EVENTUALLY PHASE OVER THE
CENTER OF THE COUNTRY AROUND THE MIDDLE OF NEXT WEEK. THIS PROCESS
OCCURS THE FASTEST WITH THE GFS WHILE DP/DT SHOWS THAT THE SLOWER
ECMWF IS BECOMING EVEN SLOWER WITH TIME.
ON SATURDAY...A WAVE MOVING IN FROM THE CENTRAL PLAINS WILL BRING
THICKENING CLOUDINESS AND SHOWERS BACK ACROSS THE FA FROM SW TO NE
DURING THE DAY. A BRIEF BREAK IN THE PRECIPITATION IS EXPECTED
SATURDAY NIGHT BEFORE A MORE POTENT WAVE BEGINS TO TAKE SHAPE OVER
THE CENTRAL PLAINS ON SUNDAY. THIS WAVE IS BEING DRIVEN BY THE
SOUTHERN STREAM ENERGY. USING THE SLOWER ECWMF...THE LOW IN THE
PLAINS TAKES UNTIL MONDAY EVENING TO ARRIVE IN SE MN. THIS PLACES
MUCH OF THE FA IN LOW LEVEL THETA-E ADVECTION FROM SUNDAY THROUGH
MONDAY...WITH SOUTHERN MN BEARING THE BRUNT OF IT. HENCE...LIKELY
POPS STREAM BACK IN ON SUNDAY FROM THE SOUTHWEST AND PERSIST THROUGH
MONDAY. WIDESPREAD HALF INCH TO ONE INCH RAINFALL IS LIKELY DURING
THIS PERIOD WITH SOME TWO INCH AMOUNTS OVER SOUTHERN MN. THERE WILL
CERTAINLY BE THE THREAT FOR SOME THUNDERSTORMS...ESPECIALLY ON
MONDAY FROM THE TWIN CITIES ON EAST AND SOUTH. STRICTLY USING THE
ECMWF TIMING WOULD INDICATE A WINDOW OF OPPORTUNITY FOR STRONG TO
SEVERE STORMS MONDAY AFTERNOON/EVENING TO THE SOUTH AND EAST OF
THE TWIN CITIES.
THE SHOWERS WILL BEGIN TO TAPER OFF MONDAY NIGHT AS THE LOW
PRESSURE SYSTEM MOVES NORTHEAST OF THE FA. INSTABILITY SHOWERS ARE
POSSIBLE MAINLY FROM CENTRAL MINNESOTA ON NORTHWARD ON TUESDAY.
SCATTERED SHOWERS ARE BACK FOR MUCH OF THE FA WEDNESDAY AND
THURSDAY AS THE UPPER TROUGH COMES TOGETHER FROM THE UPPER
MISSISSIPPI VALLEY TO THE GULF COAST. HIGH TEMPERATURES WILL BE
CLOSE TO NORMAL THIS WEEKEND...BUT THEN RETREAT TO SOME 10 TO 15
DEGREES BELOW NORMAL FOR THE MIDDLE TO END OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1248 AM CDT FRI MAY 9 2014
ALL THUNDERSTORM ACTIVITY HAS EXITED THE FORECAST AREA...WITH THE
CONCERN TURNING TO THE IFR AND LIFR CI GS BEING OBSERVED ACROSS
PARTS OF WESTERN AND CENTRAL MINNESOTA AT THIS TIME. THE RAP
ANALYZED CENTER OF THE SURFACE LOW IS ADVANCING NORTHWARD AND IS
NOW POSITIONED OVER THE NORTH METRO. WIDESPREAD FOG HAS DEVELOPED
ACROSS THE REGION WHICH WAS ADDED AT MOST TAF SITES. OVERALL
CHANGES FROM THE PREVIOUS FORECAST INCLUDE A MUCH MORE PESSIMISTIC
COG FORECAST THROUGH THE OVERNIGHT AND THE DAY. LATEST RUNS OF
BOTH THE RAP AND NAM INDICATE SOLID VERY LOW LEVEL MOISTURE ACROSS
THE BOARD ON MODEL SOUNDINGS...AND LASTING LONGER THAN PREVIOUSLY
FORECAST. MOST SITES WILL SEE AT LEAST IFR CI GS THROUGH THE
OVERNIGHT...THEN MVFR OR LOWER THROUGH MOST OF THE DAY. WITH THE
LOW BEING IN THE CENTER OF THE FORECAST AREA...WIND DIRECTION IS
COMPLETELY RELATIVE TO EACH SITES LOCATION RELATIVE THE TO COUNTER
CLOCKWISE CIRCULATION AT THIS TIME...BUT ALL SITES WILL GRADUALLY
SWITCH TO A WESTERLY WIND. WINDS WILL BE STRONG TOMORROW...WITH
GUSTS OVER 20 KNOTS LIKELY. SKIES BEGIN TO CLEAR FRIDAY NIGHT.
KMSP...STARTING THE PERIOD ON THE EDGE OF THE IFR CIGS...AND FOG
HAS ALREADY DEVELOPED AT THE TERMINAL. IFR WILL SET IN THROUGH THE
OVERNIGHT HOURS AND GRADUALLY LIFT DURING THE MORNING. MVFR OR
LOWER CIGS ARE EXPECTED INTO THE AFTERNOON. WINDS WILL SHIFT
SOUTHERLY VERY SOON...THEN TURN WESTERLY.
/OUTLOOK FOR KMSP/
SAT...VFR. CHC -TSRA. WINDS SSE 10KTS.
SUN...MVFR POSSIBLE. LIKELY -SHRA. WINDS SW TO NW 10-15 KTS.
MON...MVFR POSSIBLE. LIKELY -SHRA. WINDS NW 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...SPD
LONG TERM...RAH
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
101 AM CDT FRI MAY 9 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 400 PM CDT THU MAY 8 2014
WIDESPREAD THUNDERSTORMS ONGOING ACROSS THE FORECAST AREA. THE
CURRENT LINE OF STORMS IS THE FIRST OF TWO LINES EXPECTED OVER THE
NEXT SEVERAL HOURS. WIND AND HAIL WILL CONTINUE TO BE A THREAT AND
THE SECOND LINE WILL ALSO HAVE A TORNADO POTENTIAL...ESPECIALLY FOR
STORMS THAT REMAIN NEAR THE WARM FRONT IN SOUTHERN MN.
THERE HAS BEEN MODERATE INCREASES IN SBCAPE AND MLCAPE ALONG AND
SOUTH OF THE I-90 CORRIDOR IN FAR SOUTHERN MN OVER THE PAST 2-3
HOURS WITH THE 1000-1500 J/KG NOW BEING OBSERVED. NORTH OF THE WARM
FRONT THERE REMAINS A SEVERE WIND AND HAIL THREAT. THE WIND THREAT
WAS SOMEWHAT UNEXPECTED DUE TO THE LACK OF SURFACE ROOTED
STORMS...BUT THE FORCING AND INSTABILITY ABOVE THE SURFACE BASED CIN
IS OBVIOUSLY ENOUGH TO OVERCOME AND WE ARE GETTING WINDS OF 40-70
MPH DOWN TO THE SURFACE WITH THE MORE ORGANIZED LINES AND BOWING
SEGMENTS. THIS THREAT SHOULD CONTINUE INTO THE EARLY EVENING FOR
WEST CENTRAL WI ESPECIALLY FOR CONVECTIVE LINES THAT ARE
PERPENDICULAR TO SOUTHWEST TO NORTHEAST ORIENTATED DEEP LAYER SHEAR
VECTORS. DRYING IN THE WATER VAPOR NOW ENTERING FAR SOUTHWEST MN AND
WILL BE THE TRIGGER FOR A SECOND ROUND OF STORMS WITH THE POTENTIAL
FOR HAIL...WINDS AND EVEN TORNADOES ACROSS SOUTHERN MN. THE STRONG
DYNAMIC FORCING WILL CONTINUE TO LIFT THE WARM FRONT...BUT SURFACE
HEATING HAS BEEN LIMITED BY CONVECTIVE DEBRIS AND CLOUD COVER.
NONETHELESS...THE SECOND LINE OF STORMS WILL HAVE HIGHER END
POTENTIAL AND THE ENVIRONMENT IN SOUTH CENTRAL MN WILL SUPPORT
SUPERCELLS BETWEEN 5 PM AND 8 PM. WRAP AROUND SHOWERS WILL BE
POSSIBLE LATE TONIGHT AND EARLY FRIDAY AS THE UPPER LOW SLOWLY MOVES
NORTHEAST OF THE FORECAST AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 400 PM CDT THU MAY 8 2014
THE LONGER TERM CONTINUES TO POSE SIGNIFICANT TIMING AND OVERALL
DEVELOPMENT ISSUES WITH THE WESTERN/CENTRAL CONUS TROUGH DURING THE
PERIOD.
INITIALLY THE GFS AND ECMWF ARE IN FAIR AGREEMENT WITH THE SHORT
WAVE TROUGH MOVING THROUGH SATURDAY INTO SUNDAY. STILL CONSTITUTES
HIGHER CHANCE POPS AT THE MOMENT. AFTER THAT...THE LONGER TERM
MODELS DIVERGE ON TIMING AND DEVELOPMENT OF THE TROUGH OVER THE AREA
INTO NEXT WEEK. THE ECMWF IS MORE AMPLIFIED WITH THE SYSTEM...WITH
NORTHERN AND SOUTHERN STREAMS GRADUALLY MERGING AND LIFTING A FAIRLY
SIGNIFICANT TROUGH/SURFACE LOW NORTHEAST TOWARD THE GREAT LAKES BY
MIDWEEK. THIS COULD INCLUDE THE THREAT OF STRONG/SEVERE STORMS AS
WELL. WILL HAVE TO CONTINUE TO MONITOR MODEL TRENDS WITH THIS
SYSTEM. BOTH MODELS TREND COLDER AIR FILTERING INTO THE NORTHERN
CONUS AS THE TROUGH DIGS SOUTH AND EAST. HIGHS WILL ONLY BE IN THE
50S AND LOWS WILL BE DROPPING INTO THE MIDDLE 30S WHICH WILL
CONTINUE THE THREAT FOR FROST FROM WEDNESDAY INTO THE FOLLOWING
WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1248 AM CDT FRI MAY 9 2014
ALL THUNDERSTORM ACTIVITY HAS EXITED THE FORECAST AREA...WITH THE
CONCERN TURNING TO THE IFR AND LIFR CIGS BEING OBSERVED ACROSS
PARTS OF WESTERN AND CENTRAL MINNESOTA AT THIS TIME. THE RAP
ANALYZED CENTER OF THE SURFACE LOW IS ADVANCING NORTHWARD AND IS
NOW POSITIONED OVER THE NORTH METRO. WIDESPREAD FOG HAS DEVELOPED
ACROSS THE REGION WHICH WAS ADDED AT MOST TAF SITES. OVERALL
CHANGES FROM THE PREVIOUS FORECAST INCLUDE A MUCH MORE PESSIMISTIC
CIG FORECAST THROUGH THE OVERNIGHT AND THE DAY. LATEST RUNS OF
BOTH THE RAP AND NAM INDICATE SOLID VERY LOW LEVEL MOISTURE ACROSS
THE BOARD ON MODEL SOUNDINGS...AND LASTING LONGER THAN PREVIOUSLY
FORECAST. MOST SITES WILL SEE AT LEAST IFR CIGS THROUGH THE
OVERNIGHT...THEN MVFR OR LOWER THROUGH MOST OF THE DAY. WITH THE
LOW BEING IN THE CENTER OF THE FORECAST AREA...WIND DIRECTION IS
COMPLETELY RELATIVE TO EACH SITES LOCATION RELATIVE THE TO COUNTER
CLOCKWISE CIRCULATION AT THIS TIME...BUT ALL SITES WILL GRADUALLY
SWITCH TO A WESTERLY WIND. WINDS WILL BE STRONG TOMORROW...WITH
GUSTS OVER 20 KNOTS LIKELY. SKIES BEGIN TO CLEAR FRIDAY NIGHT.
KMSP...STARTING THE PERIOD ON THE EDGE OF THE IFR CIGS...AND FOG
HAS ALREADY DEVELOPED AT THE TERMINAL. IFR WILL SET IN THROUGH THE
OVERNIGHT HOURS AND GRADUALLY LIFT DURING THE MORNING. MVFR OR
LOWER CIGS ARE EXPECTED INTO THE AFTERNOON. WINDS WILL SHIFT
SOUTHERLY VERY SOON...THEN TURN WESTERLY.
/OUTLOOK FOR KMSP/
SAT...VFR. CHC -TSRA. WINDS SSE 10KTS.
SUN...MVFR POSSIBLE. LIKELY -SHRA. WINDS SW TO NW 10-15 KTS.
MON...MVFR POSSIBLE. LIKELY -SHRA. WINDS NW 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...DWE
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1207 AM CDT Fri May 9 2014
.UPDATE...
Issued at 730 PM CDT THU MAY 8 2014
Surprisingly busy evening. Shield of rain with embedded
convection has proved to be interesting, with some isolated damage
reports with brief bowing/spin up vorts in shallow convective
cells/elements. Low level 0-1km helicity actually fairly stout
over the Mo Ozarks this afternoon/evening. Overall trend of the
eastern cwfa convection is downward and expect that trend to
continue.
Deeper scattered convection is occurring ahead of a cold front over
eastern KS with the most notable updrafts w-nw-n of KCNU. Storms
having a tough time of it, but still seeing a stronger updraft or
two firing up. MLCAPE of around 1000 J/kg is occurring just ahead
of the front, but drops off quite a bit has you head east-se into
MO. 0-6km bulk shear more than adequate for storm organization
where somewhat stronger instability occurs over se KS and far
western MO later this evening. HRRR however, really not doing much
with the existing convection owing to a lack of progged overall
instability. Will watch trends, but the weakening trend of the
HRRR looks good later this evening.
Later tonight, a veering low level jet and moisture advection
should allow some additional elevated convection to develop
overnight into Friday morning ahead of the low level front with
the approach of shortwave/upper jet max.
&&
.SHORT TERM...(This Evening and Tonight)
Issued at 300 PM CDT THU MAY 8 2014
An upper level trough is currently pushing east into the central
Plains as an associated area of surface low pressure pushes
northeast across eastern Nebraska. A cold front ALSO extends south
from the low and is pushing east across central Kansas and
Oklahoma.
Convection is ongoing across the area. This activity formed over
Oklahoma overnight and continues to develop and push to the
northeast. These showers and thunderstorms will continue to track
northeast across the area this afternoon into the early evening
hours. Deep layer shear is on the weak side across the area.
Instability is starting to increase across the eastern Ozarks as
more heating was able to occur in these locations before clouds
were able to overspread the area. The overall severe potential is
on the low side with this activity, but with slightly better
instability there could be a few strong wind gusts with any bow
segments that can develop this afternoon and early this evening.
This activity will push east of the area by the early to mid
evening hours.
The clouds are clearing from west to east across eastern Kansas
into central Oklahoma behind this convection. We will have to see
how far east the clearing can make it this afternoon/early this
evening. The clearing will likely make it over to the far western
portion of the forecast area. Additional thunderstorms are
expected to develop across northeastern Oklahoma into eastern
Kansas along a cold front late this afternoon into this evening.
This activity will then track to the northeast and may clip
southeastern Kansas and far western Missouri. Deep layer wind
shear will begin to increase from west to east this evening and if
enough clearing occurs and enough instability can develop, hail in
excess of quarters will be possible with stronger storms. These storms
may congeal into a line and track east across the area. If the
line does develop winds in excess of 60mph will be possible. There
would also be a small risk for a brief tornado within this line
generally northwest of a Columbus Kansas to Osceola Missouri Line
this evening.
The cold front will then slowly sag southeast towards the area late
this evening into the overnight hours. Showers and thunderstorms
are expected to develop and ride along the front overnight. The
front will push over the far northern and western portions of the
forecast area tonight. Locally heavy rainfall will occur where the
training of storms can occur along the front. Due to the dry
antecedent conditions the overall flood risk is low with this
potential heavy rainfall.
.LONG TERM...(Friday through Thursday)
Issued at 300 PM CDT THU MAY 8 2014
An active weather pattern will continue Friday into early next
week as the a couple storm system track through the region.
Any convection that develops overnight tonight should push east of
the area by Friday morning, with clearing expected behind this
activity. The cold front will continue to track southeast through
the area on Friday. Areas southeast of the front will become
unstable. Better deep layer shear will be over the region on
Friday afternoon allowing organized updrafts. Additional
thunderstorms will develop along the front, and these storms will
have the potential to become strong a severe. The main risk will
be large hail with a few of the strongest storms capable of hail
to golf balls generally along and southeast of the Interstate 44
corridor. The front will push south of the area Friday evening
with dry conditions overnight Friday.
The front will then lift back north across the area Saturday.
Thunderstorms area expected to develop along and north of the
front as it lifts through the region. A few of these storms could
become strong to severe with large hail the main risk. South of the
front instability will increase but there will not be much in a way
of lift, and a cap will be increasing through the day as a warm
air mass in the mid level spreads over the area. So, think all in all
most of the activity will occur along and ahead of the front on
Saturday.
Another upper level system will track through the region late this
weekend into early next week. Medium range models continue to
differ on the track, timing, and strength of this system. The cold
front will sag south then sweep through the region as the upper
level trough approaches and sweeps through the region. Additional
severe storm potential will be possible, but details/evolution of
storms are lacking this far out in time.
Northwest flow aloft pattern will setup over the region behind
this system through the middle of next week behind this system.
Cooler conditions will occur across the region in this northwest
flow pattern.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1158 PM CDT THU MAY 8 2014
Scattered showers and thunderstorm will be possible for the
regions terminals through 10z as a cold front moves very slowly to
the east across Kansas. Ceilings will become MVFR across the area
during the overnight hours with slowly improving flight conditions
during the day on Friday.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
UPDATE...DSA
SHORT TERM...Wise
LONG TERM...Wise
AVIATION...Hatch
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1148 PM CDT Thu May 8 2014
.UPDATE:
Issued at 853 PM CDT Thu May 8 2014
A north to south area or band of showers and a few thunderstorms
was moving slowly eastward through east central and southeast MO
and west central and southwest IL. The intensity of the radar
returns have weakened over the St Louis metro area with better
rains both north and south. This precipitation was in a region of
low-mid level warm air advection ahead of a southwest flow
shortwave. This activity will eventually translate east of our
forecast area later this evening, with a break in the
precipitation expected until more showers and storms now across
northwest and west central MO and southeast KS, along and just
ahead of an approaching cold front, shifts into our forecast area
late tonight. The HRRR model also tries to bring some of the
convection now across AR northeastward into southeastern MO late
tonight. Could not rule out isolated hail and strong wind gusts
from the stronger storms late tonight. Mild temperatures should
continue tonight with slight cooling, or cooler temperatures over
the extreme northwestern portion of our forecast area behind the
cold front.
GKS
&&
.SHORT TERM: (Through Late Tonight)
Issued at 256 PM CDT Thu May 8 2014
SHRA/TSRA trends are the primary concern this evening, and are
remaining very difficult to pin down. Early on, N-S band of
showers and thunderstorms now moving into central MO will work its
way east during the remainder of the afternoon and early evening.
Have leaned heavily on the HRRR runs for trends over the next 3-6
hours, as it continues to provide superior guidance on the trends
with this area of convection. Passage of the shortwave fueling
this precip will likely cause area to diminish a bit in coverage
and intensity during the evening, but additional (and hard to
time) upstream shortwaves, as well as persistent WAA and
associated isentropic ascent, should generate additional shower
and thunderstorm activity during the late evening and overnight
hours in the warm sector. Precip threat (especially in our NW
counties) will also be driven by convection that forms along the
cold front and works its way east with time.
Truett
.LONG TERM: (Friday through Next Thursday)
Issued at 256 PM CDT Thu May 8 2014
Overnight elevated SHRA/TSRA forced by the LLJ will probably be
ongoing at daybreak on Fri, at least over part of the CWA. As the
core of the LLJ shifts northeastward into IL/IN, the greatest
moisture convergence and forcing for pcpn will also shift out of
the CWA. Consequently, there should be a decrease in precipitation
coverage or perhaps even a lull during the mid to late morning
hours on Fri. The absence of widespread precipitation combined
with some breaks in the clouds should be sufficient for afternoon
destabilization across the southeastern one-half to one-third of
the CWA. This detail matters because a trough with a vort max in
its base will be approaching from the west. Large scale ascent
from DCVA as well as lift ahead of the cold front will likely
occur in an environment with H7-H5 lapse rates of 6-7.5 deg C/km
and 40-60 kts of 0-6 km bulk shear as well as nearly
unidirectional wind profiles. These parameters are sufficient for
severe thunderstorms with hail and wind as the primary threats.
Although recent model runs all depict a solution where the cold
front moves through most of the CWA on Fri night and then stalls
in southern MO before lifting northward as a warm front on Sat,
the effective boundary might end up much farther south by Sat
morning depending on outflow boundaries from convection on Fri/Fri
night. If this occurs, then the temperature forecast for Sat may
be too warm. Shortwave ridging aloft is expected on Sat with a
compact vort max moving across southern MN, which is much farther
north than yesterday`s model runs. The H85 LLJ associated with the
vort max moving across MN could produce enough lift over the warm
front to support scattered SHRA/TSRA in MO/IL, especially if
forecast H7-H5 lapse rates of 7-8 deg C/km are realized. SHRA/TSRA
are also possible on Sat night due to moisture convergence along a
strengthening southwesterly LLJ.
A new trough develops out west over the weekend, inducing surface
cyclogenesis over the plains and eventually sending another cold
front through MO/IL early next week. Models disagree on how
quickly the trough shifts eastward into the central CONUS, leading
to disagreements on how quickly the cold front moves through the
LSX CWA. It appears that there will be a period of northwest flow
or cyclonic flow during the middle of next week depending on how
the trough evolves. Expect cooler temperatures in such a pattern
with precip chances dependent on shortwaves and moisture
availability.
Kanofsky
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1148 PM CDT Thu May 8 2014
Showers have moved out of all of the terminals at the moment, but
there are additional showers and scattered thunderstorms over
western and southern Missouri that are moving toward them. Will
continue with the same timing, though have narrowed the window as
I do not think the rain will last more than 2-3 hours. There are
MVFR ceilings currently at KIRK, and low MVFR ceilings over
southeast Kansas and northeast Oklahoma which I expect to
eventually spread into the terminals later tonight. These ceilings
will eventually dissipate by mid-late morning on Friday. Still
expect a broken line of storms to develop over east central
Missouri around 21Z on Friday afternoon that will move east into
Illinois by 00Z Friday evening. This is reflected by going TAF.
Specifics for KSTL: Showers and scattered thunderstorms currently over
southern and western Missouri will move into the terminal between
09-12Z. Expect this activity to have MVFR conditions associated
with it that will last past when the rain is over. Conditions will
improve by late morning. A broken line of thunderstorms will
develop in the vicinity of KSTL around 21Z on Friday and then move
east into Illinois thereafter.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BISMARCK ND
102 AM CDT FRI MAY 9 2014
.UPDATE...
ISSUED AT 1259 AM CDT FRI MAY 9 2014
TRIMMED POPS SLIGHTLY ACROSS THE SOUTHEAST AS RADAR RETURNS ARE
DIMINISHING QUICKLY IN THE AREA. OTHERWISE CURRENT FORECAST LOOKS
TO BE ON TRACK.
UPDATE ISSUED AT 948 PM CDT THU MAY 8 2014
RAIN EXITING THE CENTRAL SECTION OF THE STATE AND NOW PRIMARILY
IN THE JAMES RIVER VALLEY. TRIMMED POPS CENTRAL. OTHERWISE SO FAR
CURRENT FORECAST LOOKS GOOD.
UPDATE ISSUED AT 655 PM CDT THU MAY 8 2014
AT 630 PM CDT...SATELLITE LOOPS SHOW HIGH CLOUDS SPREADING OVER
SOUTHWEST NORTH DAKOTA REPOPULATING THE CLEAR AREA. H300 CLOSED
LOW ON THE RAP MODEL SUGGESTS CIRCULATION AROUND THIS FEATURE IN
NORTHEAST WYOMING LIKELY HELPING TO SPREAD THESE HIGH CLOUDS OVER
SOUTHWEST ND. MEANWHILE...H500 LOW MIGRATING THROUGH NORTHEAST SOUTH
DAKOTA INTO SOUTHEAST NORTH DAKOTA. LIKE THE CURRENT POPS AND WILL
NOT CHANGE AT THIS TIME. MAINLY CLOUDS. MAY BE ABLE TO DROP POPS
CENTRAL AFTER 9 PM.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 339 PM CDT THU MAY 8 2014
RAINFALL ENDING THIS EVENING AND A DRY FRIDAY WILL HIGHLIGHT THE
SHORT TERM.
RAINFALL THE REMAINDER OF THE AFTERNOON IS EXPECTED TO REMAIN
ALONG AND EAST OF A LINE FROM SELFRIDGE...THROUGH BISMARCK AND
HARVEY...SLOWLY DECREASING FROM WEST TO EAST. BASED UPON THE 17-19
UTC RAP/HRRR...RAIN SHOULD FINALLY END ACROSS THE JAMES RIVER
VALLEY BY 06-07 UTC. OTHERWISE FOR TONIGHT...A WEAK SURFACE RIDGE
AXIS WILL BE IN PLACE ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
GIVEN CLEAR SKIES...LIGHT WINDS AND DEW POINTS IN THE UPPER TEENS
AND 20S...WIDESPREAD OVERNIGHT LOWS IN THE 20S ARE FORECAST OUTSIDE
OF THE JAMES RIVER VALLEY WHERE GREATER CLOUD COVER AND MOISTURE
WILL KEEP LOWS IN THE 30S. LEFT THE MENTION OF FOG OUT FOR NOW DUE
TO DECEASING LOW LEVEL MOISTURE PROFILES WITH HEIGHT AND THE
GREATER LIKELIHOOD OF FROST COMPARED TO FOG. FRIDAY WILL BE CLEAR
AND DRY WITH HIGHS IN THE 60S WITH SOUTHERLY FLOW AHEAD OF THE
SURFACE LOW ACROSS EASTERN MONTANA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 339 PM CDT THU MAY 8 2014
AN ACTIVE AND COOL WEATHER PATTERN DEVELOPS FOR THE UPCOMING
WEEKEND. UNCERTAINTY INCREASES AFTERWARDS WHEN COMPARING THE
LATEST FEW RUNS OF THE GFS AND ECMWF.
UPPER LOW/TROUGH OVER THE PACIFIC NORTHWEST DIGS ACROSS THE
WESTERN CONUS FRIDAY NIGHT INTO SATURDAY...MOVING OVER THE ROCKIES
SUNDAY. 12Z GFS IS MORE PROGRESSIVE AND MOVES THE TROUGH EAST BY
MONDAY NIGHT...WHILE THE 00Z/12Z ECMWF LINGERS THE TROUGH THROUGH
TUESDAY. NORTHWEST FLOW IS ADVERTISED BY BOTH MODELS BEHIND THE
TROUGH...LIKELY ACTIVE WITH EMBEDDED WAVES MOVING THROUGH THE
REGION.
BASICALLY HAVE CHANCES FOR PRECIPITATION THROUGH THE PERIOD ALONG
WITH CONTINUED COOL/BELOW AVERAGE TEMPERATURES. BEST CHANCES FOR
PRECIPITATION WILL BE OVER THE WEEKEND AS SFC LOW PRESSURE AND LEAD
WAVES MOVE ACROSS THE DAKOTAS. MIX OF RAIN/SNOW POSSIBLE WEST
SUNDAY MORNING AS COLDER AIR IS PULLED SOUTH FROM CANADA.
ADDITIONAL SNOW POSSIBLE EARLY NEXT WEEK IF THE EUROPEAN`S
SOLUTION IS CORRECT WITH A SLOWER EASTWARD PROGRESSION ALLOWING
FOR ANOTHER SHOT OF COLD AIR INTO THE REGION.
MODELS PORTRAY NO INDICATION OUR COOL AND WET PATTERN WILL CHANGE
THROUGH AT LEAST MID-MAY...AND POSSIBLY NOT UNTIL AFTER THE THIRD
WEEK OF MAY AT THE EARLIEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1259 AM CDT FRI MAY 9 2014
VFR CONDITIONS EXPECTED ACROSS ALL TERMINALS THROUGH THE 06 UTC TAF
PERIOD. MID CLOUD DECK WILL MOVE EAST OF KJMS AROUND 12 UTC
TONIGHT. WINDS WILL MAINLY BE LIGHT AND VARIABLE TONIGHT...EXCEPT
AT KJMS...AND GRADUALLY BECOME SOUTHERLY THROUGH THE DAY FRIDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MM
SHORT TERM...AYD
LONG TERM...NH
AVIATION...MM
AREA FORECAST DISCUSSION
NWS TULSA OK
1156 PM CDT THU MAY 8 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
MVFR CEILINGS WILL BE PREVALENT OVERNIGHT INTO FRIDAY
MORNING...WITH SOME IFR CEILINGS POSSIBLE AT TIMES...ESPECIALLY AT
KMLC. SCATTERED SHOWERS AND THUNDERSTORMS IN NORTHEAST OKLAHOMA
WILL BE MOST LIKELY TO AFFECT KBVO FOR THE FIRST FEW HOURS OF THE
FORECAST PERIOD. CONDITIONS WILL BECOME VFR AT ALL SITES BY FRIDAY
AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 858 PM CDT THU MAY 8 2014/
DISCUSSION...
DRYLINE/FRONTAL STORMS BEGINNING TO PUSH EASTWARD INTO WESTERN
OSAGE COUNTY AT THIS TIME. BOTH THE HRRR AND THE LOCAL WRF
INDICATE ADDITIONAL DEVELOPMENT POTENTIAL PRIMARILY ALONG THE
KANSAS BORDER OVERNIGHT. SOME SEVERE THREAT WILL EXIST...BUT
LIMITED INSTABILITY FARTHER EAST WILL START TO LIMIT THE OVERALL
THREAT SOMEWHAT AS THE NIGHT GOES ON. TRENDS ON THE AFOREMENTIONED
STORMS ALREADY SHOWING THIS TO SOME EXTENT. OVER SOUTHEAST
OKLAHOMA AND WESTERN ARKANSAS...ONGOING PRECIP WILL CONTINUE TO
SHIFT EAST OF THE AREA...WITH PRECIP CHANCES DECREASING ESPECIALLY
AFTER MIDNIGHT. THIS WILL ALSO DIMINISH ANY FLOOD THREAT THAT
EXISTS. ADDITIONAL TWEAKS TO POP GRIDS WILL LIKELY BE
FORTHCOMING...ESPECIALLY FOR POST 06Z TIME FRAME. TEMPERATURE
WISE...WITH CLOUDS REMAINING THROUGH MOST OF THE
NIGHT...LOWS WILL REMAIN RELATIVELY WARM...IN THE 60S FOR MOST OF
THE AREA.
PREV DISCUSSION... /ISSUED 638 PM CDT THU MAY 8 2014/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
CEILINGS WILL BECOME MVFR AT ALL LOCATIONS OVERNIGHT. AN ISOLATED
SHOWER OR THUNDERSTORM WILL BE POSSIBLE...ESPECIALLY AT THE
NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS SITES...BUT THE CHANCES
ARE TOO LOW TO INCLUDE IN THE TAFS. CONDITIONS WILL IMPROVE TO VFR
BY FRIDAY AFTERNOON AND WINDS WILL BECOME LIGHT AS A WEAK FRONTAL
BOUNDARY ACROSS THE AREA BEGINS TO WASH OUT.
PREV DISCUSSION... /ISSUED 302 PM CDT THU MAY 8 2014/
DISCUSSION...
A LARGE AREA OF RAINFALL WITH EMBEDDED THUNDERSTORMS CONTINUES TO
MOVE EASTWARD ACROSS THE CWA THIS AFTERNOON AHEAD OF AN UPPER TROUGH
TRAVERSING THE SOUTHERN PLAINS. THE PRECIPITATION IS ENDING FROM
WEST TO EAST ACROSS MUCH OF NORTHEAST OKLAHOMA WITH SOME CLEARING
BEHIND THAT. THE DRYLINE REMAINS TO OUR WEST AND A COLD FRONT REMAINS TO
OUR NORTH. THIS SCENARIO SHOULD BE CONDUCIVE FOR STORMS TO REDEVELOP
LATE THIS AFTERNOON AND EVENING IN NORTHEAST OKLAHOMA AND POSSIBLY
INTO NORTHWEST ARKANSAS.
AFTER TONIGHT... THUNDERSTORM CHANCES WILL EASE BACK FOR A COUPLE OF
DAYS AS UPPER FLOW BRIEFLY BECOMES ZONAL. ANOTHER UPPER TROUGH
DEVELOPING TO OUR WEST WILL MOVE ACROSS THE AREA SUNDAY INTO MONDAY.
A COLD FRONT ACCOMPANYING THIS SYSTEM WILL SWEEP ACROSS THE CWA
BEGINNING EARLY MONDAY MORNING. THUNDERSTORM CHANCES WILL INCREASE
ALONG AND AHEAD OF THE FRONT. SEVERE STORMS MAY BE POSSIBLE EVEN
THOUGH THE TIMING OF FRONTAL PASSAGE IS DISADVANTAGEOUS.
FOR THE REMAINDER OF NEXT WEEK... MILD CONDITIONS WILL PREVAIL.
PRECIPITATION CHANCES WILL BE MINIMAL WITH TEMPERATURES SLIGHTLY
BELOW SEASONAL AVERAGES.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...05
AREA FORECAST DISCUSSION
NWS TULSA OK
858 PM CDT THU MAY 8 2014
.DISCUSSION...
DRYLINE/FRONTAL STORMS BEGINNING TO PUSH EASTWARD INTO WESTERN
OSAGE COUNTY AT THIS TIME. BOTH THE HRRR AND THE LOCAL WRF
INDICATE ADDITIONAL DEVELOPMENT POTENTIAL PRIMARILY ALONG THE
KANSAS BORDER OVERNIGHT. SOME SEVERE THREAT WILL EXIST...BUT
LIMITED INSTABILITY FARTHER EAST WILL START TO LIMIT THE OVERALL
THREAT SOMEWHAT AS THE NIGHT GOES ON. TRENDS ON THE AFOREMENTIONED
STORMS ALREADY SHOWING THIS TO SOME EXTENT. OVER SOUTHEAST
OKLAHOMA AND WESTERN ARKANSAS...ONGOING PRECIP WILL CONTINUE TO
SHIFT EAST OF THE AREA...WITH PRECIP CHANCES DECREASING ESPECIALLY
AFTER MIDNIGHT. THIS WILL ALSO DIMINISH ANY FLOOD THREAT THAT
EXISTS. ADDITIONAL TWEAKS TO POP GRIDS WILL LIKELY BE
FORTHCOMING...ESPECIALLY FOR POST 06Z TIME FRAME. TEMPERATURE
WISE...WITH CLOUDS REMAINING THROUGH MOST OF THE
NIGHT...LOWS WILL REMAIN RELATIVELY WARM...IN THE 60S FOR MOST OF
THE AREA.
&&
.PREV DISCUSSION... /ISSUED 638 PM CDT THU MAY 8 2014/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
CEILINGS WILL BECOME MVFR AT ALL LOCATIONS OVERNIGHT. AN ISOLATED
SHOWER OR THUNDERSTORM WILL BE POSSIBLE...ESPECIALLY AT THE
NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS SITES...BUT THE CHANCES
ARE TOO LOW TO INCLUDE IN THE TAFS. CONDITIONS WILL IMPROVE TO VFR
BY FRIDAY AFTERNOON AND WINDS WILL BECOME LIGHT AS A WEAK FRONTAL
BOUNDARY ACROSS THE AREA BEGINS TO WASH OUT.
PREV DISCUSSION... /ISSUED 302 PM CDT THU MAY 8 2014/
DISCUSSION...
A LARGE AREA OF RAINFALL WITH EMBEDDED THUNDERSTORMS CONTINUES TO
MOVE EASTWARD ACROSS THE CWA THIS AFTERNOON AHEAD OF AN UPPER TROUGH
TRAVERSING THE SOUTHERN PLAINS. THE PRECIPITATION IS ENDING FROM
WEST TO EAST ACROSS MUCH OF NORTHEAST OKLAHOMA WITH SOME CLEARING
BEHIND THAT. THE DRYLINE REMAINS TO OUR WEST AND A COLD FRONT REMAINS TO
OUR NORTH. THIS SCENARIO SHOULD BE CONDUCIVE FOR STORMS TO REDEVELOP
LATE THIS AFTERNOON AND EVENING IN NORTHEAST OKLAHOMA AND POSSIBLY
INTO NORTHWEST ARKANSAS.
AFTER TONIGHT... THUNDERSTORM CHANCES WILL EASE BACK FOR A COUPLE OF
DAYS AS UPPER FLOW BRIEFLY BECOMES ZONAL. ANOTHER UPPER TROUGH
DEVELOPING TO OUR WEST WILL MOVE ACROSS THE AREA SUNDAY INTO MONDAY.
A COLD FRONT ACCOMPANYING THIS SYSTEM WILL SWEEP ACROSS THE CWA
BEGINNING EARLY MONDAY MORNING. THUNDERSTORM CHANCES WILL INCREASE
ALONG AND AHEAD OF THE FRONT. SEVERE STORMS MAY BE POSSIBLE EVEN
THOUGH THE TIMING OF FRONTAL PASSAGE IS DISADVANTAGEOUS.
FOR THE REMAINDER OF NEXT WEEK... MILD CONDITIONS WILL PREVAIL.
PRECIPITATION CHANCES WILL BE MINIMAL WITH TEMPERATURES SLIGHTLY
BELOW SEASONAL AVERAGES.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...22
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
333 AM CDT FRI MAY 9 2014
.DISCUSSION...
AT 06Z...THERE WAS A WEAK AREA OF LOW PRESSURE OVER CENTRAL
OKLAHOMA AND ANOTHER WEAK AREA OF LOW PRESSURE NORTH OF DEL RIO.
SFC DEW PTS REMAIN IN THE LOWER 70S. RADAR IS A LITTLE MORE ACTIVE
THAN THE PAST FEW NIGHTS WITH A LINE OF STORMS DEVELOPING ACROSS
EXTREME SE TX FROM KBPT TO KGLS AND A SMALL CLUSTER NEAR KGRK.
WATER VAPOR IMAGERY SHOWS A WELL DEFINED S/WV IN EASTERN NEW
MEXICO AND THIS FEATURE WAS MOVING EAST AND WILL SERVE AS A
CATALYST FOR SHRA/TSRA OVER PARTS OF CENTRAL AND EASTERN TEXAS
TODAY. THE DISTURBANCE WILL APPROACH SE TX THIS AFTN AND FEEL IT
WILL TRIGGER TSRA OVER MAINLY THE WESTERN HALF OF THE CWA. NAM 12
SOUNDING FOR KCLL ARE VERY UNSTABLE WITH PWATS INCREASING FROM
1.38 THIS MORNING TO 1.79 THIS AFTN. CAPE VALUES EXCEED 3000 J/KG
AND LI`S DROP TO -9. SPC HAS OUTLOOKED THE WESTERN HALF OF SE TX
IN SLIGHT RISK AND SEE NO REASON TO DISAGREE. THE NAM...GFS AND
ECMWF ALL SHOW A SPEED MAX APPROACHING THIS AFTERNOON SO IT LOOKS
LIKE ALL THE INGREDIENTS ARE IN PLACE FOR SOME SEVERE WEATHER OVER
THE WESTERN ZONES. TOWARD THE HOUSTON AREA AND THE COAST...CAPPING
LOOKS TO REMAIN AN ISSUE AND PWATS ACTUALLY DROP THIS AFTN. WILL
MAINTAIN LOW END CHANCE POPS BUT SOUNDINGS LOOK MUCH LESS
FAVORABLE. THINGS SHOULD SETTLE DOWN QUICKLY TONIGHT WITH THE
LOSS OF HEATING. FWIW...THE HRRR INITIALIZED BEST THIS MORNING AND
HAVE LEANED TOWARD THIS SOLUTION FOR THE SHORT TERM.
VERY WARM AND HUMID CONDITIONS ARE EXPECTED OVER THE WEEKEND.
CAN`T RULE OUT ISOLATED SHOWERS WITH HEATING EACH DAY. PWATS
REMAIN AROUND 1.5-1.6 INCHES SO WILL MENTION A SLIGHT CHANCE OF
SHRAS EACH DAY.
THINGS BECOME A LITTLE MORE MUDDLED MON-WED. A DEEP UPPER LEVEL
TROUGH AND SURFACE COLD FRONT WILL APPROACH THE STATE ON MONDAY.
MODELS ARE IN GOOD AGREEMENT THROUGH MONDAY 12Z BUT DIVERGE
SIGNIFICANTLY THEREAFTER. GFS IS ABOUT 24-30 HOURS FASTER THAN THE
ECMWF. THE CANADIAN SUPPORTS THE SLOWER ECMWF. NOT REALLY SURE
HOW THINGS WILL EVENTUALLY TRANSPIRE THIS FAR OUT SO HAVE STARTED
POPS ON MONDAY AND WILL CARRY POPS THROUGH WEDNESDAY. AT THE
CURRENT TIME...FEEL TUESDAY WILL BE THE BEST DAY FOR RAIN CHANCES
BUT THAT IS SUBJECT TO CHANGE. HAVE RAISED RAIN CHANCES ON TUESDAY
TO 50 PERCENT. CONSIDERABLY COOLER AND DRIER CONDITIONS WILL
DEVELOP IN THE WAKE OF THE FRONT FOR THE SECOND HALF OF NEXT WEEK
WITH MIN TEMPS POSSIBLY FALLING BACK INTO THE 50S. 43
&&
.MARINE...
ONSHORE WINDS ARE EXPECTED THROUGH THE WEEKEND. WIND SPEEDS WILL BE
HIGH ENOUGH THIS MORNING FOR CAUTION CONDITIONS. MODERATE TO STRONG
ONSHORE WINDS ARE THEN EXPECTED TO DEVELOP SUNDAY NIGHT AS LOW
PRESSURE DEVELOPS OVER THE PLAINS. THE MODELS THEN DIFFERED ON THE
PASSAGE OF A COLD FRONT THROUGH SE TX AND OFF THE COAST. LIKED THE
SLOWER ECMWF.
40
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 86 69 88 71 88 / 50 30 10 10 10
HOUSTON (IAH) 86 71 87 73 87 / 30 20 20 10 20
GALVESTON (GLS) 81 73 82 73 82 / 30 20 20 10 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 5 AM CDT EARLY THIS
MORNING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CDT THU MAY 8 2014
.UPDATE...
ISSUED AT 1021 PM CDT THU MAY 8 2014
ONE LAST BATCH OF SHOWERS AND THUNDERSTORMS ARE MOVING ACROSS
SOUTHEAST MINNESOTA AND NORTHEAST IOWA. 0-3KM/MLCAPE HAS BEEN
DROPPING OVER THE PAST FEW HOURS AND EXPECT THAT TREND TO CONTINUE
THROUGH THE REST OF THE NIGHT. BASED ON 09.01Z RAP ANALYSIS...IT
ALSO APPEARS THAT THESE STORMS ARE OCCURRING IN A RELATIVE MINIMUM
OF 0-6KM SHEAR AS WELL. THUS...EXPECT THAT STORMS SHOULD REMAIN
SUB-SEVERE FROM HERE ON OUT THROUGH THE REST OF TONIGHT.
TEMPERATURES WILL REMAIN MILD IN THE UPPER 60S UNTIL THE COLD
FRONT PUSHES THROUGH TOWARD DAYBREAK WITH CONVECTION NOT EXPECTED
ALONG THIS FRONT.
&&
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 241 PM CDT THU MAY 8 2014
MAIN FORECAST CONCERNS THIS PERIOD...SHRA/TSRA/SEVERE CHANCES THRU
THIS EVENING...LINGERING -SHRA CHANCES FRI...TEMPERATURES.
18Z DATA ANALYSIS HAD A 1000MB LOW OVER NORTHEAST NEB WITH A TROUGH
NORTHEAST INTO NORTHWEST WI AND WARM FRONT ARCING EAST ACROSS
NORTHERN IA INTO SOUTHERN WI. WARM FRONT CONTINUES TO SEPARATE TO
DISTINCT AIRMASSES...70S WITH DEW POINTS IN THE 60S SOUTH OF THE
WARM FRONT...60S WITH DEW POINTS IN THE 50S. SB CAPE SOUTH OF THE
FRONT IN THE 1500-2500 J/KG RANGE...ELEVATED 500-1000 J/KG NORTH OF
THE WARM FRONT. AREA WSR-88D/S SHOWING CONVECTION DEVELOPING/
EXPANDING ACROSS THE SOUTH HALF OF IA...WITH/AHEAD OF SHORTWAVE
ENERGY LIFTING UP THE EAST SIDE OF THE MID LEVEL LONG WAVE TROUGH.
08.12Z MODELS GENERALLY INITIALIZED WELL. GFS AGAIN ABOUT 5F HIGH
WITH SFC DEW POINTS IN THE MOISTURE PLUME COMING NORTH THRU THE
MID MS VALLEY. SOLUTIONS CONVERGING ON A TIGHT COMPROMISE
CONSENSUS OF THE EARLIER RUNS AS THE TROUGHING/ENERGY OVER THE
ROCKIES/PLAINS LIFTS NORTHEAST THRU THE UPPER MIDWEST TONIGHT
THRU FRI NIGHT. STILL SOME LOWER LEVEL DETAIL DIFFERENCES ON
CONVECTION EVOLUTION THRU THIS EVENING...BUT AFTER THAT SOLUTIONS
QUITE SIMILAR FOR LATER TONIGHT THRU FRI NIGHT AS COOLER/DRIER AIR
SPREADS IN BEHIND THE PASSING LOW/COLD FRONT. FCST CONFIDENCE
GENERALLY GOOD FOR TONIGHT THRU FRI NIGHT.
FOR THE SHORT TERM...AS OF EARLY THIS AFTERNOON...CONVECTIVE SCENARIO
FOR LATER THIS AFTERNOON/THIS EVENING REMAINS IN QUESTION. MAIN FOCUS
FOR TSRA DEVELOPMENT REMAINS WESTERN IA/SOUTHWEST MN...NEAR THE SFC
LOW/TROUGH/FRONTS AND CLOSER TO THE STRONGER SHORTWAVE LIFTING
TOWARD EASTERN SD. SHRA/TSRA DEVELOPING/SPREADING NORTH ACROSS
IA...ALONG WITH THE CLOUD COVER CONSUMING/LIMITING CAPE EARLY THIS
AFTERNOON AND MUDDYING THE TSRA/SEVERE EVOLUTION FOR LATER THIS
AFTERNOON/EVENING. LOWER LEVEL CONVERGENCE/FORCING WOULD POINT TO A
LINE OF STRONG/SEVERE TSRA DEVELOPING IN WESTERN IA/SOUTHWEST MN
THEN LIFTING NORTHEAST ACROSS MN/IA/WI IN THE 21Z-04Z TIME-FRAME.
STRONGEST 0-6KM BULK SHEAR OF 30-60KTS IS OVER THE WEST PORTIONS OF
THE FCST AREA THIS AFTERNOON AND NORTHWEST PORTIONS OF THE FCST AREA
THIS EVENING. SWODY1 SEEMS TO HAVE THE THREATS/RISKS LAYED OUT
WELL...BASED ON CONVECTION LIFTING NORTH ACROSS IA NOT INTERFERING
TOO MUCH. WILL STAY THE COURSE WITH HIGHEST SHRA/TSRA CHANCES LATER
THIS AFTERNOON/EVENING WITH WHAT SHOULD BE A LINE OF CONVECTION
MOVING EAST/NORTHEAST ACROSS THE FCST AREA WITH/AHEAD OF THE SFC-
850MB TROUGH/COLD FRONT. SEE SWODY1 FOR MORE DETAILS ON THE SEVERE
THREATS THRU THIS EVENING.
925-850MB COLD ADVECTION/DRYING SPREAD RATHER QUICKLY ACROSS THE
FCST AREA LATE THIS EVENING/OVERNIGHT AS THE SFC-850MB LOW LIFTS
INTO NORTHEAST MN. PW VALUES OF 1 TO 1.5 INCHES AT 00Z FRI ARE HALF
THAT BY 12Z FRI. THIS AND PASSAGE OF THE SFC-850MB TROUGH/FRONT
SWEEP THE BULK OF THE SHRA/TSRA EAST AND OUT OF THE FCST AREA BY 12Z
FRI. ONLY SOME SMALL LINGERING -SHRA CHANCES IN THE EAST/NORTH ENDS
OF THE FCST AREA BY 12Z FRI. A SECONDARY SHORTWAVE TO LIFT ACROSS
THE AREA FRI AFTERNOON ALONG WITH SOME 850-700MB WRAP-AROUND/
DEFORMATION BAND MOISTURE. DEEPEST OF THIS MOISTURE ACROSS THE NORTH
END OF THE FCST AREA...WITH STEEP LOW LEVEL LAPSE RATES AND WEAK
INSTABILITY TO ABOUT 750MB. CONTINUED THE SMALL -SHRA CHANCES ACROSS
MAINLY THE NORTHEAST 1/3 OF THE FCST AREA THRU FRI AFTERNOON...WHICH
BLENDS WELL WITH NEIGHBORING GRIDS. LOSS OF DIURNAL HEATING AND
PASSING OF THE SECOND SHORTWAVE QUICKLY PUTS AN END TO THIS AND LEFT
FRI NIGHT DRY AS HIGH PRESSURE AND SHORTWAVE RIDGING ALOFT BUILD
INTO THE REGION. A COOLER PERIOD TONIGHT THRU FRI NIGHT AS A COOL
925MB AIRMASS SETTLES OVER THE REGION. WINDS/CLOUDS TO KEEP LOWS
TONIGHT ABOVE NORMAL. BELOW NORMAL HIGHS FRI UNDER THE COOL 925MB
AIRMASS. BELOW NORMAL LOWS FRI NIGHT UNDER MOSTLY CLEAR SKIES/LIGHT
WINDS. USED THE MODEL/ENSEMBLE CONSENSUS LOWS/HIGHS FOR TONIGHT THRU
FRI NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 241 PM CDT THU MAY 8 2014
MAIN FORECAST CONCERNS FOR SAT THRU SUN NIGHT...SHRA/TSRA CHANCES
THRU THE PERIOD AS MORE TROUGHING/SHORTWAVES TAKE AIM AT THE UPPER
MIDWEST.
DECENT AGREEMENT AMONG THE 08.12Z MODELS CONTINUES SAT AS THE NEXT
STRONGER SHORTWAVE TRACKS INTO MN BY LATE IN THE DAY. IMPROVING
CONSENSUS FOR RISING HGTS/SHORTWAVE RIDGING TO BUILD ACROSS THE
UPPER MIDWEST LATER SAT/SAT NIGHT...AHEAD OF THE NEXT STRONG/LONG
WAVE TROUGH TO DIG INTO THE WESTERN CONUS. TREND CONTINUES STRONGER
WITH THIS NEXT TROUGHING INTO THE ROCKIES SAT NIGHT/SUN THEN
EJECTING INTO THE WESTERN PLAINS SUN NIGHT. SHORTWAVE RIDGE AXIS
THAT BUILDS OVER THE REGION SAT NIGHT QUICKLY MOVES EAST SUN...WITH
THE REGION ALREADY UNDER THE INFLUENCE OF SOUTHWEST FLOW ALOFT AHEAD
OF THE NEXT TROUGH FOR SUN AFTERNOON/NIGHT. WITH RUN-TO-RUN
CONSISTENCY AND THE IMPROVING CONSENSUS...SAT THRU SUN NIGHT FCST
CONFIDENCE IS AVERAGE TO GOOD.
BREAK BETWEEN SYSTEMS FRI NIGHT INTO SAT IS BRIEF. THE NEXT
SHORTWAVE INTO MN LATER SAT QUICKLY SPREADS INCREASING LOWER LEVEL
THERMO-DYNAMIC FORCING/LIFT AND INCREASING MOISTURE/THETA-E
CONVERGENCE INTO THE FCST AREA THRU THE DAY ON SAT. INITIAL
MOISTURE/LIFT GOES INTO SATURATION SAT MORNING...WITH INCREASING
SHRA CHANCES INTO SAT AFTERNOON/EVENING AS THE DEEPEST MOISTURE/
STRONGER OF THE LIFT MOVES ACROSS. CARRIED HIGHEST RAIN CHANCES
LATER SAT AFTERNOON/EVENING...THE LOWER LATER SAT NIGHT BEHIND THE
SFC-850MB TROUGH AXIS. INDICATIONS FOR 250 TO AS MUCH AS 1K J/KG MU
CAPE INTO THE AREA AT 00Z SUN SO CONTINUED TSRA MENTION FOR MUCH OF
THE FCST AREA SAT AFTERNOON/EVENING. NEXT BREAK BETWEEN SYSTEMS IS
ALSO RATHER BRIEF LATER SAT NIGHT/SUN MORNING. WITH THE PROGRESSIVE
AND ACTIVE FLOW...THE UPPER MIDWEST IS BACK UNDER SOUTHWEST FLOW
ALOFT SUN AFTERNOON/NIGHT...AHEAD OF STRONG MID LEVEL TROUGHING
SWINGING THRU THE CENTRAL/SOUTHERN ROCKIES. INCREASING MOISTURE/
LIFT/INSTABILITY QUICKLY SPREAD BACK INTO THE FCST AREA FOR SUN
AFTERNOON/NIGHT. PW VALUES IN THE 1 INCH PLUS RANGE BY 00Z MON...
AHEAD OF THE NEXT STRONGER SHORTWAVE AND SFC-850MB LOW LIFTING
NORTHEAST TOWARD/INTO THE UPPER MIDWEST SUN NIGHT. RAISED SHRA/TSRA
CHANCES INTO THE 35-55 PERCENT RANGE SUN AFTERNOON AND 55-70 PERCENT
RANGE SUN NIGHT. SOME LOCALLY HEAVY RAINS POSSIBLE SUN NIGHT...
DEPENDING ON WHERE THE SFC LOW TRACKS/SFC BOUNDARIES SET UP. DUE TO
SOME UNCERTAINTIES WITH WHAT WOULD BE TIMING OF SHRA/TSRA IN/AROUND
THE AREA AND CLOUD COVER...USED THE MODEL/ENSEMBLE CONSENSUS HIGHS/
LOWS FOR SAT THRU SUN NIGHT.
FOR MONDAY THROUGH THURSDAY.../DAYS 4 TO 7/...
MAIN FORECAST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES/RAIN AMOUNTS
MON/MON NIGHT...SHRA CHANCES/COOLER TEMPS TUE-THU.
MEDIUM RANGE MODEL RUNS OF 08.00Z AND 08.12Z ALL SHOW THE SCENARIO
OF STRONG TROUGHING MOVING INTO THE CENTRAL CONUS MON. GFS REMAINS
FASTER THAN ECMWF/CAN-GEM. GOOD CONSENSUS FOR THE STRONG TROUGHING
TO THEN VERY SLOWLY MOVE INTO/ACROSS THE MID/UPPER MS VALLEY TUE
THRU THU...WITH CAN-GEM THE SLOWER/STRONGER OUTLIER BY WED. OVERALL
TREND IS SLOWING AND STRONGER WITH THE MID CONUS TROUGHING NEXT
WEEK. EVEN WITH SOME DIFFERENCES AMONG THE MODELS FOR MON-THU THE
SENSIBLE WEATHER OUTCOMES ARE MORE SIMILAR THAN ONE WOULD USUALLY
EXPECT. DAY 4-7 FCST CONFIDENCE IS AVERAGE WITH RAIN CHANCES THRU
THE PERIOD BUT GOOD FOR BELOW NORMAL TEMPS FOR TUE-THU.
EVEN WITH THE DIFFERENCES ON PROGRESSION OF THE LONG-WAVE TROUGH
ON MON...GOOD CONSENSUS FOR A STRONG PIECE OF ENERGY TO BE LIFTING
NORTHEAST ACROSS THE UPPER MIDWEST MON/MON NIGHT. RATHER STRONG
SFC LOW PROGGED TO ACCOMPANY THIS SHORTWAVE NORTHEAST ACROSS THE
REGION MON. WITH PW VALUES OF AN INCH OR MORE...SHRA/TSRA CHANCES
IN THE 40-65 PERCENT RANGE MON/MON NIGHT LOOK GOOD. POTENTIAL FOR
1 TO 2 INCHES OF RAIN FROM LATER SUN NIGHT THRU MON NIGHT. COLDER
AIR POURS IN FOR TUE THRU THU AS THE THE NORTHERN STREAM PORTION
OF THE MID LEVEL TROUGH SETTLES INTO THE UPPER MIDWEST. 850MB
TEMPS FALL TO A FEW DEGREES EITHER SIDE OF 0C FOR MUCH OF TUE-
THU...SOME 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL. AFTER MORE
NORMAL EARLY MAY TEMPS THROUGH THE WEEKEND...TEMPS FOR TUE-THU
TREND AROUND 10F BELOW NORMAL. WITH THIS COLD CORE OF AIR ALOFT...
STEEP LOW-MID LEVEL LAPSE RATE AND SHORTWAVES ROTATING THRU THE
TROUGH WITH ROUNDS OF INCREASED MOISTURE/FORCING...SMALL -SHRA
CHANCES MUCH OF THE TUE-THU PERIOD REASONABLE FOR NOW. GIVEN THE
TIMING/DETAIL UNCERTAINTIES...DID NOT STRAY MUCH FROM THE MODEL/
ENSEMBLE CONSENSUS HIGHS/LOWS AND RAIN CHANCES FOR DAYS 4-7.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1140 PM CDT THU MAY 8 2014
WITH MOST OF THE RAIN AND STORMS HAVING MOVED OFF TO THE
EAST...THE MAIN FOCUS IS ON THE IFR CEILINGS LINGERING BEHIND THE
COLD FRONT/SURFACE LOW. THIS COLD FRONT WILL MOVE THROUGH SHORTLY
AFTER MIDNIGHT WITH WINDS COMING AROUND TO THE SOUTHWEST TO WEST.
AS THEY DO...THE IFR DECK THAT IS CURRENTLY IN WESTERN MINNESOTA
WILL MOVE EAST OVERNIGHT AND SIT OVER RST/LSE THROUGH MUCH OF THE
MORNING. FORECAST SOUNDINGS SHOW SOME MIXING OCCURRING BY EARLY
AFTERNOON AS DRIER AIR MOVES IN.
&&
.HYDROLOGY...
ISSUED AT 241 PM CDT THU MAY 8 2014
FLOODING CONTINUES ALONG THE MISSISSIPPI RIVER...WITH LOCATIONS
CRESTING BETWEEN GENOA AND LANSING. SHOWERS AND THUNDERSTORMS TODAY
WILL PRODUCE ANYWHERE FROM A HALF INCH TO ONE INCH OF RAIN. THIS
WILL LIKELY SLOW THE FALL FOR LOCATIONS NORTH OF MCGREGOR...AND MAY
INCREASE CRESTS SLIGHTLY SOUTH OF MCGREGOR.
POTENTIAL FOR 1 TO 2 INCHES OF RAINFALL FROM LATE SUN NIGHT THRU
MON EVENING. THIS COULD HAVE ADDITIONAL IMPACTS AND PRODUCE
ADDITIONAL RISES ON AREA RIVERS ALREADY RUNNING HIGH FROM THE
ABOVE AND MUCH ABOVE NORMAL RAINS OF APRIL.
CHECK OUT THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...HALBACH
HYDROLOGY....RRS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1137 PM MDT THU MAY 8 2014
.UPDATE...
ISSUED AT 833 PM MDT THU MAY 8 2014
LATEST RADAR LOOP WAS SHOWING SHOWERS CONTINUING TO FLARE UP
ACROSS EXTREME SOUTHEAST WYOMING MAINLY ALONG AND EAST OF THE
LARAMIE RANGE DUE TO A COOL DOME ALOFT AND UPSLOPE FLOW PROMOTING
THE INSTABILITY. THE MODELS ARE CONTINUING TO ADVERTISE THIS DOME
OF COOL AIR SHIFTING EAST OVERNIGHT WHICH SHOULD ALLOW FOR MORE
SUBSIDENCE TO MOVE INTO SOUTHEAST WYOMING. HOWEVER...I AM A LITTLE
LEARY ABOUT YANKING THE POPS COMPLETELY UNTIL 3AM...SINCE WE DO
HAVE SOMEWHAT OF AN UPSLOPE COMPONENT. THE OTHER CONCERN WE HAVE
TONIGHT IS THE FOG POTENTIAL WHERE THE SNOWFALL TOOK PLACE LAST
NIGHT. SNOW/CLOUD DISCRIMINATOR PRODUCT FROM CIRA IS SHOWING THE
BULK OF THE SNOW OCCURRED IN THE NORTHERN PANHANDLE WHICH LOOKS
TO BE THE MOST FAVORABLE REGION FOR FOG DEVELOPING OVERNIGHT. THIS
AREA IS ALSO BEGIN TO CLEAR OUT WITH SOME PATCHY FOG BEGINNING TO
SHOW UP IN DAWES AND BOX BUTTE COUNTIES. HRRR ALSO SHOWS GOOD
INDICATIONS OF THIS FOG PERSISTING THROUGH THE NIGHT. WE MAY ALSO
HAVE TO WATCH THIS AREA FOR POTENTIAL FOG ADVISORY.
OTHERWISE...CURRENT FORECAST APPEARS TO BE ON TRACK.
UPDATE ISSUED AT 415 PM MDT THU MAY 8 2014
SENDING OUT A QUICK UPDATE TO INCREASE PRECIPITATION CHANCES
ACROSS ALBANY...LARAMIE AND KIMBALL COUNTIES AS A BATCH OF RAIN
AND EMBEDDED THUNDER MOVES EAST THROUGH THAT REGION. THE BULK OF
THE CONVECTION SHOULD END AFTER SUNSET.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 330 PM MDT THU MAY 8 2014
SNOW HAS COME TO AN END ACROSS THE NORTHERN NE PANHANDLE THIS AFTN
AS AN INTENSE SFC LOW AND ASSOCIATED MID LEVEL TROWAL HAVE EXITED THE
AREA TO THE NORTHEAST. ONLY CONCERN IN THE NEAR TERM WILL BE THE
POTENTIAL FOR CONVECTIVE ACTIVITY THROUGH THIS EVE. CLEARING SKIES ON THE
BACK SIDE OF THE SYSTEM HAVE ALLOWED TEMPS TO WARM NICELY...INTO THE
MIDDLE TO UPPER 40S ACROSS MUCH OF SOUTHEAST WY. MID LEVELS ARE QUITE
COLD WITH LAPS SOUNDINGS SHOWING H5 TEMPS TO -20C...SO A GREAT SETUP
FOR INSTABILITY RAIN SHOWERS. LATEST RADAR LOOP SHOWS THIS ACTIVITY
CONFINED TO THE I80 CORRIDOR...AND BELIEVE THIS TREND WILL CONTINUE
THROUGH THE EARLY EVE AS MESOSCALE MODELS SHOW LIFTED INDICES AROUND
ZERO HERE. WE HAVE SEEN SOME LIGHTNING STRIKES ALONG THE CO BORDER
IN THE PAST FEW HOURS...BUT MODEST CONVECTIVE INSTABILITY PROFILES
SUGGEST MOST OF THIS ACTIVITY WILL BE OF THE SHOWER VARIETY. LARGE
SCALE SUBSIDENCE WILL BUILD INTO THE AREA BY LATE EVE BENEATH WEAK
SHORTWAVE RIDGING...ENDING THE THREAT FOR SHOWERS AND STORMS. NEXT
CHANCE FOR CONVECTION WILL BE FRI AFTN AHEAD OF THE NEXT WEAK MID LEVEL
SHORTWAVE EMBEDDED WITHIN ZONAL FLOW ALOFT. WENT AHEAD AND ADDED ISO
THUNDER TO THE GRIDS AS THE LATEST GFS IS SHOWING 500 TO 750 J/KG OF
SBCAPE. NAM BUFKIT SOUNDINGS SHOW SOME WEAK ELEVATED INSTABILITY AS
WELL. NO CONCERNS FOR SEVERE WEATHER THOUGH. DESPITE SOME HIGH LEVEL
CLOUD COVER LIKELY MOVING OVERHEAD WITH INCREASING 700-300 MILLIBAR
MOISTURE...DOWNSLOPE WARMING SHOULD AID IN WIDESPREAD 60S FOR HIGHS
EAST OF THE LARAMIE RANGE. MOST OF THE SNOW IN THE PANHANDLE SHOULD
BE MELTED BY THEN...SO EXPECT A MINIMAL IMPACT TO TEMPS.
ATTENTION THEN SHIFTS TO THE POTENTIAL FOR YET ANOTHER MAJOR STORM
FOR THE WEEKEND. MODELS ARE IN GREAT AGREEMENT SHOWING A VIGOROUS
UPPER-LEVEL TROUGH DIGGING INTO THE GREAT BASIN ON SAT. MOIST SOUTH
WEST FLOW ALOFT AND A FEW DISTURBANCES EMANATING FROM THE PARENT
TROUGH SUGGESTS ANOTHER GOOD CHANCE FOR SHOWERS AND STORMS...THOUGH
WESTERLY LOW LEVEL FLOW SUGGESTS THE BULK OF THIS ACTIVITY WILL BE
ALONG AND WEST OF THE LARAMIE RANGE. LIMITED MOISTURE SHOULD KEEP
SEVERE WEATHER AT BAY THIS TIME AROUND...THOUGH SHEAR PROFILES
WILL BE RATHER STRONG. GFS...NAM...AND ECMWF ALL SHOW A STRONG SFC
COLD FRONT BLASTING SOUTH ACROSS THE CWA LATE SAT NIGHT. NORTH TO
NORTH EAST SFC UPSLOPE FLOW AND LARGE SCALE VERTICAL ASCENT WILL
ALMOST CERTAINLY FAVOR PCPN DEVELOPMENT...BUT THE BIG QUESTION NOW
IS EXACTLY WHERE. THE GFS IS STILL THE OUTLIER WITH HEAVY PCPN
BANDING FROM NORTH CENTRAL CO INTO THE SOUTHERN PANHANDLE...WHILE
THE ECMWF AND GEM ARE MUCH FURTHER NORTH WITH THE FRONTOGENESIS
BAND AND WOULD AFFECT A LARGER PART OF OUR CWA. REGARDLESS...H7
TEMPS FALL TO BETWEEN -8C AND -12C IN THE POST FROPA AIR MASS WITH
1000-500 MB THICKNESSES RANGING FROM 540 TO 549 DM FROM NORTHWEST
TO SOUTHEAST AT 12Z SUN. THIS WOULD SUPPORT SNOW... AND A LOT OF
IT IF MODELED QPF VALUES ARE ANYTHING CLOSE TO WHAT ACTUALLY
TRANSPIRES. IT IS A LITTLE UNSETTLING THAT THE ECMWF HAS BEEN
CONSISTENT OVER THE LAST COUPLE OF RUNS WITH THE PLACEMENT OF THE
HEAVIEST SNOW. IT WAS ALSO THE FIRST TO LOCK ON TO THIS PARTICULAR
STORM EVOLUTION. IT IS MUCH TOO EARLY FOR ANY SORT OF
HEADLINE...BUT CONFIDENCE IS HIGH THAT A PORTION OF OUR CWA WILL
SEE SIGNIFICANT WINTER WEATHER. WENT AHEAD AND ISSUED A SPECIAL
WEATHER STATEMENT HIGHLIGHTING THE POTENTIAL STORM FOR PUBLIC
AWARENESS.
.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 330 PM MDT THU MAY 8 2014
FORECAST CHALLENGES EARLY IN THE EXTENDED PERIOD WILL FOCUS ON THE
SPRING STORM SYSTEM MOVING ACROSS THE CENTRAL ROCKIES AND PLAINS.
THERE ARE TIMING...STRENGTH AND POSITION DIFFERENCES WITH EMERGENCE
OF THE UPPER LOW FROM THE CENTRAL GREAT BASIN SUNDAY. THE GFS IS
TRENDING SLIGHTLY FASTER AND NORTH OF THE ECMWF. AT 12Z SUNDAY...GFS
PROGS THE 554DM LOW OVER EAST CENTRAL UT...WHILE THE ECMWF/S 550DM
LOW IS SITUATED IN SOUTHWEST UT. THE PRIMARY SURFACE LOW SHOWN BY
THE GFS AT THE SAME TIME IS OVER FAR SOUTHWEST CO AND THE ECMWF/S
LOW IS ALONG THE AZ/UT BORDER. BY 00Z MONDAY...GFS 559DM LOW IS
OVER FAR WESTERN CO AND THE ECWMF 554DM LOW IS OVER SOUTH CENTRAL
UT. THE SURFACE LOW REDEVELOPS AND INTENSIFIES OVER THE NORTHERN
TX PANHANDLE IN THE GFS...AND SOUTHWEST CORNER OF KS IN THE ECMWF.
THE 1000-500MB THICKNESS GRADIENT RAPIDLY TIGHTENS AND INTENSE
LOW/MID LEVEL ASCENT DEVELOPS. COLD AIR AT LOW LEVELS WILL BE
ADVECTED SOUTH INTO THE STORM SYSTEM ALONG THE EASTERN SLOPES OF
THE ROCKIES...LOWERING SNOW LEVELS SIGNIFICANTLY. PLENTY OF
MOISTURE WRAPPING INTO THE LOW...MID LEVEL QG FORCING AND LOW
LEVEL UPSLOPE WILL RESULT IN SIGNIFICANT PRECIPITATION....WITH
SNOW LEVELS POSSIBLY DROPPING AS LOW AS 4500 FT. A CONSENSUS OF
THE GFS AND ECMWF QPF FROM 00Z SUNDAY THROUGH 12Z MONDAY INDICATES
BETWEEN 1.5 AND 2.5 INCHES OF LIQUID PRECIPITATION. CONSENSUS MODEL
SNOW ACCUMULATIONS PROJECT BETWEEN 12 AND 20 INCHES FOR THE MOUNTAINS...
4 TO 10 INCHES LOWER ELEVATIONS ALONG AND SOUTH OF I-80...AND 1 TO 4
INCHES NORTH OF I-80. STILL PLENTY OF UNCERTAINTY WITH THIS STORM
AND WILL CONTINUE TO EVALUATE TRENDS AS THE STRENGTH AND TRACK OF
THE STORM SYSTEM CAN CHANGE FROM ONE MODEL RUN TO THE NEXT.
IT WILL BE MUCH COLDER SUNDAY AS 700MB TEMPERATURES FALL TO -5C TO
-10C. HIGH TEMPERATURES SUNDAY WILL RANGE FROM THE 20S MOUNTAINS TO
THE 40S OVER THE PLAINS. THESE TEMPERATURES MAY BE NEED TO BE LOWERED
WITH LATER FORECASTS. GUSTY NORTHEAST WINDS OF 20 TO 30 MPH WILL ADD
TO THE CHILL.
IF YOU BELIEVE THE GFS...SNOW WILL BEGIN TO TAPER OFF FROM WEST
TO EAST MONDAY MORNING. THE ECMWF KEEPS THE UPPER TROUGH AXIS ALONG
THE FRONT RANGE WHICH WOULD PROLONG THE PRECIPITATION INTO MONDAY
NIGHT. NORTHWEST FLOW ALOFT WILL PREVAIL TUESDAY THROUGH THURSDAY.
THERE ARE INDICATIONS THAT IT WILL NOT BE DRY STABLE FLOW AS THERE
WILL BE SOME MINOR DISTURBANCES WHICH MAY GENERATE SHOWERY EPISODES.
TEMPERATURES MODERATE TOWARD SEASONAL NORMALS BY THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY EVENING)
ISSUED AT 1115 PM MDT THU MAY 8 2014
MAINLY VFR ACROSS THE AREA TONIGHT BUT SOME LOCAL LOW CLOUDS AND
FOG WILL PRODUCE IFR. AFTER SUNRISE FOG AND LOW CLOUDS WILL
DISSIPATE. WINDS WILL MAINLY BE ON THE LIGHT SIDE TONIGHT THROUGH
FRIDAY. SCATTERED SHOWERS AND ISOLATED WEAK THUNDERSTORMS WEST OF
THE LARAMIE RANGE FRIDAY AFTERNOON WITH ISOLATED SHOWERS AND
THUNDERSTORMS TO THE EAST OF THE LARAMIE RANGE.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MDT THU MAY 8 2014
NO FIRE WEATHER CONCERNS. MILD CONDITIONS ARE EXPECTED FOR FRIDAY
AND SATURDAY...BUT WINDS AND RELATIVE HUMIDITY VALUES ARE EXPECTED
TO REMAIN WELL OUTSIDE OF CRITICAL THRESHOLDS. ANOTHER SPRING STORM
WILL AFFECT THE AREA SUNDAY AND MONDAY...BRINGING COOLER TEMPERATURES
AND WIDESPREAD RAIN AND SNOW.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...REC
SHORT TERM...HAMMER
LONG TERM...JAMSKI
AVIATION...SML
FIRE WEATHER...HAMMER
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1123 AM EDT Fri May 9 2014
.Near Term [This Afternoon Through Tonight]...
There is higher than normal uncertainty in the forecast from late
this afternoon into tonight. Model guidance continues to indicate
an area of heavy rainfall somewhere along the northern Gulf coast
in that time period - with a sharp cutoff on the eastern extent.
In other words, the models all generally agree that there will be
a considerable gradient in rainfall somewhere in the vicinity of
the western border of our forecast area. However, there is some
variation in the exact placement of this gradient on the order of
about 50-70 miles which makes a huge difference in impacts for our
area. In general, global models have kept much of the rain west of
our area through 12Z Saturday while a fair number of 4km WRF runs
push the heavy rain into far western parts of our area (generally
along and west of a PAM-DHN line).
Models seem to be struggling to initialize a well-defined outflow
boundary and other mesoscale features across western Alabama and
Mississippi. When compared with recent objective analysis, the
models seem to be placing these features a bit too far west. This
argues that the surface and boundary layer foci for additional
convective development this afternoon will be situated a bit
closer to our local area. However, the large scale forcing
mechanisms - including the LLJ and favored RFQ of the upper level
jet streak - continue to be further west closer to what the
models are portraying. Therefore, there is some uncertainty as to
how to correct for the misplacement of these mesoscale features in
the models, as large scale forcing mechanisms seem to be modeled
fairly well. It may not be a simple linear adjustment (shifting
the model QPF east 50 miles or so), given the lagging UVV aloft.
The 14Z RAP analysis suggested that the boundary layer behind the
outflow boundary over much of MS and W AL had been convectively
overturned with MUCAPE less than 250 j/kg. Therefore, it seems
that most of the new convective development would be focused in
the warm, moist air mass just ahead of the outflow boundary this
afternoon - or just west of our area. There is some evidence of
this happening already on radar mosaics. This may put heavy rain
and thunderstorms in a better position to push into our area
tonight. However, given the high level of uncertainty, and only a
handful of convection-allowing models showing high QPF in our
area, we have opted not to issue a Flash Flood Watch at this time.
We did bump up PoPs and QPF in the far western parts of our
forecast area with this update, and will re-evaluate a watch this
afternoon after new model guidance arrives.
&&
.Hydrology...
The only rivers that remain above flood stage at this time are the
Choctawhatchee River at Bruce and several sites along the Suwannee
River and stages are falling at all these locations. There is a
chance of some heavy rainfall tonight and early Saturday in the
far western part of our area - mainly in the Choctawhatchee
drainage basin (which includes some smaller streams and rivers).
There remains considerable uncertainty as to whether this will
occur, but given high soil moisture levels it would not take much
rainfall to create flooding problems in those areas.
The most up-to-date river forecast information can always be found
on our AHPS page (below).
http:/water.weather.gov/ahps2/index.php?wfo=tae
&&
.Prev Discussion [304 AM EDT]...
.Short Term [Saturday Through Sunday]...
The upper ridge will be temporarily shunted southeast of the area
from tonight through Saturday with heights building once again on
Sunday as another upstream trough amplifies across the Rockies.
The surface high will remain in place across the region. The ridge
will keep any synoptic scale systems from approaching the area.
However, increasing moisture and instability will contribute to a
gradual upward trend in PoPs into Saturday. After that, the deep
layer ridging will re-assert itself with PoPs lowering, at least
across our western zones. Rainfall totals are not expected to be
high enough for any flooding concerns. Increased clouds and
showers will keep daytime temps a bit lower than recent days with
somewhat hotter temps returning for Sunday. Min temps will remain
in the 60s.
.Long Term [Sunday Night Through Friday]...
While no systems of any real significance are expected to impact our
CWA until perhaps the very end of the period as the next deepening
upper level trough approaches from the west, there are still some
discrepancies yet to be resolved in the Global models for the
beginning of the period. If the GFS is correct, the next shortwave
will swing rapidly through the region by this Saturday night with
generally fair and warm weather for the bulk of the period as zonal
flow gradually transitions into upper level ridging. The ECMWF, on
the other hand, keeps conditions a bit more unsettled on Sunday and
Monday, as it attempts to cutoff a weak upper level low over the
northern Gulf coast. However, should this even occur, it will do so
under rising heights, so while this may make for a somewhat
unsettled end to the upcoming weekend, only sct showers and storms
would likely be the end result, and certainly not significant enough
to cancel outdoor plans.
.Aviation...
[Through 06Z Saturday] MVFR restrictions in a fog/ceiling mix may
be possible briefly this morning at ECP, TLH, and VLD. Otherwise,
VFR will prevail today under a scattered to broken mid and high
level clouds deck. Southerly winds may be gusty at times to around
20 knots.
.Marine...
High pressure will continue to ridge from the Atlantic westward
across the Gulf Coast states through the period. This will maintain
onshore winds across the waters, primarily out of the southeast.
Wind speeds are expected to remain below headline criteria. A front
will approach from the northwest on Tuesday.
.Fire Weather...
Moisture and rain chances will be increasing over the next few days
and hazardous fire weather conditions are not anticipated.
Dispersions will likely be rather high this afternoon.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 89 66 87 63 89 / 0 10 20 10 20
Panama City 84 70 81 69 84 / 10 50 30 20 20
Dothan 89 66 84 65 89 / 10 30 40 20 30
Albany 90 67 85 64 90 / 0 20 40 20 30
Valdosta 93 66 89 63 92 / 0 10 20 10 30
Cross City 90 66 87 64 88 / 0 10 10 10 30
Apalachicola 82 69 81 68 82 / 0 30 20 10 20
&&
.TAE Watches/Warnings/Advisories...
FL...High Rip Current Risk through this evening for Coastal Bay-
Coastal Franklin-South Walton.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...WOOL
LONG TERM...GOULD
AVIATION...HARRIGAN
MARINE...WOOL
FIRE WEATHER...HARRIGAN
HYDROLOGY...LAMERS
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
910 AM EDT FRI MAY 9 2014
.UPDATE (REST OF TODAY AND TONIGHT)...
13Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUES TO SHOW AN AMPLIFIED
UPPER LEVEL PATTERN IN PLACE ACROSS THE CONUS. LONGWAVE TROUGHING
SITS OVER THE CENTRAL PLAINS WITH A POTENT SHORTWAVE IMPULSE
PIVOTING NORTHWARD OVER THE UPPER MS VALLEY/WESTERN GREAT LAKES. THE
DOWNSTREAM FLOW THEN RIDGES UP OVER THE EASTERN SEABOARD EXTENDING
FROM THE EASTERN GULF/FLORIDA PENINSULA TO QUEBEC. THIS RIDGE WILL
REMAIN PARKED OVER OUR LOCAL AREA FOR ONE MORE DAY PROVIDING WARM
AND MOSTLY DRY CONDITIONS. WV IMAGERY SHOWS A BIT MORE UPPER LEVEL
MOISTURE HAS WORKED OVERHEAD COMPARED TO PREVIOUS DAYS...AND THIS
WILL COME IN THE FORM OF PERIODIC CIRRUS. THIS HIGH LEVEL MOISTURE
IS SHOWN ON THE 12Z KTBW SOUNDING ABOVE 400MB...HOWEVER BELOW THIS
LEVEL...THE SUPPRESSION FROM THE UPPER RIDGE CONTINUES TO SUPPLY US
WITH A DRY COLUMN THROUGH A MAJORITY OF THE TROP. A STRONG
SUBSIDENCE INVERSION IS ALSO SEEN IN THE SOUNDING PROFILE AROUND
900MB. THERE ARE ACTUALLY SOME DECENT LAPSE RATES IN THE LOWER
LEVELS ABOVE THIS INVERSION...HOWEVER THE DEPTH OF THE DRY AIR AND
THE OVERALL SUPPRESSION SHOULD KEEP ANY SEA-BREEZE SHOWERS VERY
LIMITED.
AT THE SURFACE...RIDGE OF HIGH PRESSURE CENTERED OVER THE WESTERN
ATLANTIC CONTINUES TO RIDGE BACK TO THE WEST WITH AN AXIS NEAR THE
I-10 CORRIDOR. OUR POSITION TO THE SOUTH OF THIS RIDGE AXIS IS
PROVIDING A LIGHT SOUTHEAST FLOW TO THE REGION.
REST OF TODAY...
MOSTLY SUNNY SKIES TO START THE MORNING OFF AT MOST LOCATIONS. THE
NEAR 100% INSOLATION WILL ALLOW TEMPERATURES TO WARM QUICKLY INTO
THE 80S...ON THEIR WAY TO AFTERNOON HIGHS IN THE UPPER 80S TO LOWER
90S ACROSS THE INTERIOR AND LOWER/MIDDLE 80S CLOSER TO THE COAST.
WILL SEE ENOUGH TERRESTRIAL HEATING TO FORCE A SEA-BREEZE THIS
AFTERNOON...HOWEVER THE SOUTHEAST FLOW JUST ABOVE THE SURFACE IS 15+
KNOTS PER MODEL AND CONFIRMED BY KTBW SOUNDING. THIS FLOW WOULD BE
ENOUGH TO PIN ANY SEA-BREEZE TO THE COAST (OR EVEN KEEP IT JUST
OFFSHORE). HOWEVER...NAM/LOCAL HIRES WRFARW GUIDANCE BOTH SHOWING
THIS FLOW RELAXING SOMEWHAT FOR THE AFTERNOON...SO WILL SHOW THE
SEA-BREEZE MAKING SOME INLAND PROGRESS...IT JUST MAY BE LATER
ARRIVING THAN DURING PREVIOUS DAYS.
THE OPPOSING FLOW WILL ADD SOME LOW LEVEL CONVERGENCE/FOCUS ALONG
THIS SEA-BREEZE BOUNDARY. CAN NOT RULE OUT A FEW ISOLATED/BRIEF
SHOWERS AFTER 3-4PM...HOWEVER...WITH THE RIDGE ALOFT...UPDRAFTS ARE
GOING TO STRUGGLE ABOVE 10-12KT...AND ANY CUMULUS TOWERS WILL BE
FIGHTING SIGNIFICANT DRY AIR INTRUSION. FOR NOW WILL LEAVE MENTION
OF SHOWERS OUT OF THE FORECAST AS RAIN CHANCES ARE REALLY 10% OR
LESS FOR ANY PARTICULAR SPOT. HOWEVER...WILL NOT BE SURPRISED TO SEE
A SHOWER OR 2 POP UP ON RADAR LATER TODAY. LIKELY TO DISAPPEAR FROM
RADAR AS QUICKLY AS THEY APPEAR THOUGH.
TONIGHT...
SHORTWAVE ENERGY RIDING NORTHWARD FROM THE WESTERN GULF OF MEXICO TO
THE FLORIDA PANHANDLE/GEORGIA VICINITY WILL DE-AMPLIFY THE UPPER
RIDGE AND BEGIN TO SHIFT ITS AXIS SOUTH AND SOUTHEAST. BY MORNING
THE UPPER RIDGE AXIS WILL BE DOWN OVER SOUTH FLORIDA. THE SURFACE
RIDGE WILL REMAIN IN PLACE WITH A LIGHT SOUTHEAST FLOW OVER THE
AREA. THIS FLOW LOOKS TO REMAIN STRONG ENOUGH (ESPECIALLY JUST ABOVE
THE SURFACE) TO SUPPRESS ANY SIGNIFICANT FOG DEVELOPMENT. THIS IS
SHOWN IN THE SREF VISIBILITY PROBS OVERNIGHT WHICH ARE UNDER 10% FOR
VIS < 3 MILES. A MILD NIGHT UPCOMING WITH LOWS GENERALLY IN THE
UPPER 60S TO LOWER 70S. SHOULD GET DOWN INTO THE MIDDLE 60S FOR
INLAND LEVY COUNTY. NORMALLY WARMER SPOTS ALONG THE COAST SUCH AS
ST PETE WILL HOLD IN THE MIDDLE 70S. HAVE A GREAT FRIDAY EVERYONE!
&&
.MID TERM (SATURDAY-SUNDAY)...
HIGH PRESSURE WILL REMAIN THE DOMINANT WEATHER FEATURE THROUGH THE
PERIOD. THE EAST/WEST COAST SEA BREEZES SHOULD BE ENOUGH TO SPARK
ISOLATED TO WIDELY SCATTERED SHOWERS AND THUNDERSTORMS EACH
AFTERNOON...SO WILL INCLUDE SLIGHT CHANCE/LOW CHANCE POPS IN THE
FORECAST IN MOST LOCATIONS. HIGH TEMPERATURES WILL GENERALLY TOP OUT
IN THE UPPER 80S TO LOWER 90S BOTH DAYS...WITH LOWS SATURDAY NIGHT
RANGING FROM THE MID TO UPPER 60S ACROSS THE INTERIOR COOL SPOTS TO
THE LOWER 70S ALONG THE COAST.
&&
.LONG TERM (SUNDAY NIGHT-FRIDAY)...
MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT THROUGH EARLY NEXT
WEEK...WITH SOLUTIONS THEN DEVIATING WITH RESPECT TO THE HANDLING
OF AN EASTERLY WAVE DURING THE MIDDLE TO LATTER PORTION OF NEXT
WEEK. WILL FOLLOW A BLENDED APPROACH TO THE FORECAST GIVEN THE
UNCERTAINTY...AND THIS WILL RESULT IN CHANCES FOR MAINLY
AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE
LONG TERM PERIOD. AT THIS POINT...IT APPEARS THAT THE HIGHEST
PROBABILITIES FOR RAINFALL WILL FALL IN THE WEDNESDAY/THURSDAY
TIME FRAME WHEN THE DEEPEST MOISTURE WILL BE IN PLACE.
TEMPERATURES ARE EXPECTED TO RUN CLOSE TO NORMAL THROUGH THE LONG
TERM PERIODS.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH THE REST OF THE DAY AND EVENING.
EXPECT A FEW-SCT CU FIELD TO DEVELOP DURING THE AFTERNOON WITH BASES
BETWEEN 4-6KFT. SOUTHEAST FLOW OVERNIGHT LOOKS TO REMAIN ELEVATED
ENOUGH TO PREVENT MUCH IN THE WAY OF FOG DEVELOPMENT. NOT OUT OF THE
QUESTION TO SEE A BRIEF MVFR PERIOD AT KLAL OR KPGD TOWARD SUNRISE
ON SATURDAY...HOWEVER AT THIS TIME CONFIDENCE OF REDUCED
VISIBILITIES AT EITHER TERMINAL ARE LOW ENOUGH TO KEEP MENTION OUT
OF THE TAFS.
&&
.MARINE...
BREEZY CONDITIONS OVER THE COASTAL WATERS WILL SETTLE DOWN LATER
THIS MORNING WITH WINDS TURNING ONSHORE NEAR THE COAST DURING THE
EARLY TO MID AFTERNOON. WINDS WILL SHIFT BACK TO THE SOUTHEAST
OVERNIGHT AND BECOME BREEZY ONCE AGAIN...HOWEVER AT THIS TIME IT
DOES NOT APPEAR AS THROUGH CAUTIONARY LEVEL WINDS OF 15-20 KNOTS
WILL BE REACHED. THIS CONTINUED PATTERN OF ONSHORE AFTERNOON WINDS
AND OFFSHORE SLIGHTLY STRONGER FLOW AT NIGHT AND DURING THE EARLY
MORNING HOURS WILL CONTINUE THROUGH THE UPCOMING WEEKEND AS HIGH
PRESSURE REMAINS PARKED TO THE NORTH OF THE FORECAST WATERS.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY WILL BRIEFLY APPROACH CRITICAL LEVELS DURING THE
MID/LATE AFTERNOON AWAY FROM THE COAST. IN ADDITION...EFFICIENT
TRANSPORT WINDS AND GOOD DIURNAL MIXING WILL RESULT IN HIGH
DISPERSION INDICES THIS AFTERNOON AWAY FROM THE COAST AS WELL. LOW
LEVEL MOISTURE WILL INCREASE FURTHER INTO THE WEEKEND PREVENTING
RELATIVE HUMIDITY FROM REACHING CRITICAL LEVELS EITHER SATURDAY OR
SUNDAY. THERE WILL BE BETTER CHANCES FOR A FEW AFTERNOON STORMS
ALONG THE SEA-BREEZE THIS WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 90 72 88 73 / 0 0 10 0
FMY 92 70 91 71 / 0 0 20 10
GIF 90 70 90 71 / 0 0 20 20
SRQ 87 70 87 71 / 0 0 10 10
BKV 91 65 89 66 / 10 10 10 10
SPG 89 74 88 74 / 0 0 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION/MARINE/FIRE WEATHER...MROCZKA
MID TERM/LONG TERM...JELSEMA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1012 AM EDT FRI MAY 9 2014
.SYNOPSIS...
HIGH PRESSURE RIDGING INTO THE FORECAST AREA FROM THE ATLANTIC
WILL WEAKEN SATURDAY AS A DISSIPATING FRONTAL SYSTEM MOVES INTO
THE AREA. HIGH PRESSURE REGAINS CONTROL FOR THE BEGINNING OF NEXT
WEEK. ANOTHER FRONT IS EXPECTED TO AFFECT THE REGION LATE NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...THE SURFACE RIDGE WILL CONTINUE TO EXTEND INTO THE
FORECAST AREA FROM THE ATLANTIC. THE LOWER LEVELS SHOULD REMAIN
RELATIVELY DRY. SATELLITE TRENDS SHOW CONSIDERABLE MID AND UPPER
CLOUDINESS MOVING INTO THE AREA IN THE SOUTHWEST FLOW AHEAD OF THE
TROUGH. A WEAK MID-LEVEL SHORTWAVE TROUGH...A LITTLE LOW- LEVEL
CONVERGENCE ASSOCIATED WITH A WEAK LEE-SIDE TROUGH PLUS HEATING
COULD POSSIBLY SUPPORT THUNDERSTORMS LATE...BUT THE CHANCE IS VERY
LOW BECAUSE OF SHALLOW MOISTURE AND WEAK FORCING. THE LATEST HRRR
INDICATES JUST ISOLATED SHOWERS LATE IN THE DAY. THE FORECAST
APPEARS ON TRACK WITH POPS LESS THAN 20 PERCENT. IT SHOULD BE A
LITTLE COOLER THAN PREVIOUS DAYS BECAUSE OF CLOUDINESS.
HOWEVER...IT WILL LIKELY NOT BE NOTICEABLE BECAUSE OF A SLIGHT
INCREASE IN HUMIDITY.
TONIGHT...THE MODELS INDICATE AN INCREASE IN MOISTURE...BUT THE
DEEPER MOISTURE REMAINS WEST OF THE AREA. THERE MAY BE AN INCREASE
IN INSTABILITY ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH.
HOWEVER...MOISTURE SHOULD REMAIN LIMITED AND ANY CONVERGENCE
ASSOCIATED WITH A LEE-SIDE TROUGH SHOULD BE WEAK. THE SHOWER OR
THUNDERSTORM CHANCE IS LOW. THE NAM AND GFS MOS HAVE POPS LESS
THAN 20 PERCENT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
THE MODELS INDICATE AN INCREASE IN MOISTURE SATURDAY ASSOCIATED
WITH THE REMNANTS OF A COLD FRONT. PRECIPITABLE WATER IS FORECAST
TO INCREASE TO AROUND 1.5 INCHES WITH WEAK LIFT AHEAD OF THE BROAD
UPPER-LEVEL TROUGH. THERE SHOULD ALSO BE LITTLE LOW-LEVEL
CONVERGENCE ASSOCIATED WITH A WEAK LEE-SIDE TROUGH. KEPT CHANCE
POPS SATURDAY. THE GUIDANCE CONSENSUS SUPPORTS POPS AROUND 30 PERCENT.
THUNDERSTORMS MAY LINGER SATURDAY EVENING ASSOCIATED WITH CONVERGENCE
INTO THE WEAK LEE-SIDE TROUGH AND BAND OF MOISTURE FROM THE
REMNANTS OF THE FRONT PLUS HEATING. THE MODELS ARE CONSISTENT
SHIFTING DIMINISHING MOISTURE EAST SATURDAY NIGHT WITH H5 HEIGHTS
BUILDING. THE MODELS SHOW THE RIDGE REMAINING DOMINATE THROUGH
SUNDAY NIGHT WITH LITTLE MOISTURE. THE NAM AND GFS MOS SUPPORT
POPS LESS THAN 20 PERCENT LATE SATURDAY NIGHT THROUGH SUNDAY
NIGHT. USED THE WARMER TEMPERATURE GUIDANCE BECAUSE OF RECENT
VERIFICATION...UPPER RIDGING...AND THE DRY ENVIRONMENTAL CONDITIONS.
THE LOW TEMPERATURE GUIDANCE WAS CLOSE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE GFS AND ECMWF DISPLAY A MAINLY DRY PATTERN MONDAY AND TUESDAY.
THE UPPER LEVEL RIDGE CONTINUES ACROSS THE REGION THROUGH TUESDAY
WHILE SURFACE HIGH PRESSURE OVER THE WESTERN ATLANTIC RIDGES INTO
THE SOUTHEASTERN STATES. THE GFS...ECMWF...AND EKD MOS INDICATE
POPS OF 20 PERCENT OR LESS. A COLD FRONT THURSDAY MAY BRING AN
INCREASED CHANCE OF THUNDERSTORMS. BOTH THE GFS AND ECMWF DISPLAY
AN OFFSHORE LOW OR TROUGH WHICH WOULD LIMIT CONVERGENCE IN THE
FORECAST AREA. THE GFS...ECMWF AND EKD MOS HAVE POPS OF 20 TO 40
PERCENT WEDNESDAY AND THURSDAY. TEMPERATURES SHOULD BE ABOVE
NORMAL IN THE UPPER 80S AND LOWER 90S SUNDAY THROUGH
WEDNESDAY...THEN NEAR NORMAL THURSDAY. SHOULD SEE OVERNIGHT LOWS
IN THE LOW TO MID 60S.
&&
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
HIGH-LEVEL CLOUDS WILL CONTINUE TO STREAM ACROSS THE TAF SITES
THROUGH THE PERIOD IN THE SOUTHWEST FLOW ALOFT. CONVERGENCE
ASSOCIATED WITH A WEAK LEE-SIDE TROUGH PLUS MID-LEVEL SHORTWAVE
TROUGH COULD HELP SUPPORT THUNDERSTORMS BUT THE CHANCE IS VERY LOW
BECAUSE OF SHALLOW MOISTURE AND WEAK FORCING. THE HRRR INDICATES
JUST ISOLATED COVERAGE LATE THIS AFTERNOON AND THE CHANCE IS MUCH
TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME. THE
NAM BUFKIT MOMENTUM TRANSFER TOOL...GFS LAMP...AND KCAE 88D VAD
WIND PROFILE INDICATE WIND GUSTS 20 TO 25 KNOTS THIS AFTERNOON.
THE HIGH CLOUDINESS SHOULD LIMIT MIXING SOMEWHAT SO FORECASTED
GUSTS NEAR THE LOWER END OF THE RANGE. CLOUDINESS AND MIXING
SHOULD LIMIT FOG DURING THE EARLY MORNING HOURS SATURDAY. THE GFS
AND NAM MOS INDICATE VFR OR MVFR CONDITIONS WITH MVFR FOG CONFINED
TO THE RIVER-VALLEY TERMINALS OF AGS AND OGB.
.EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
Area Forecast Discussion
National Weather Service Lincoln IL
926 AM CDT Fri May 9 2014
.DISCUSSION...
ISSUED 926 AM CDT Fri May 9 2014
Overnight convection has lifted northeastward out of the area,
leaving behind only a few scattered showers along/east of the I-57
corridor this morning. Cold front is currently approaching the
Illinois River. Ahead of the boundary, southwesterly winds
continue with 14z/9am temps in the upper 60s/lower 70s. Meanwhile
behind the front, W/NW winds have dropped the temp into the upper
50s around Galesburg. Front will only make slow progress eastward
today, with additional convection likely developing ahead of it
during the afternoon hours. NAM and HRRR both suggest scattered
thunderstorms will develop in the instability axis along/south of
I-70 by mid to late afternoon. In the meantime, relatively stable
airmass in the wake of the earlier convection should keep things
quiet through early afternoon. Have updated the forecast to
significantly reduce POPs this morning. Will only mention isolated
to scattered showers east of the Illinois River through midday,
then will increase POPs to likely for showers/thunder across the
SE KILX CWA this afternoon.
Barnes
&&
.AVIATION...
ISSUED 656 AM CDT Fri May 9 2014
The slow moving cold front will finally push across the terminal
sites today. MVFR clouds between 1500-2500 FT will become more
widespread during the first 3 to 5 hours of the TAFs, as low
clouds develop near the front. A break in the rain should
eventually work its way from west to east behind the front. The
front should pass PIA to SPI by 16z, then reach CMI to DEC by 21z.
The MVFR cigs should gradually give way to VFR cigs behind the
front this afternoon. Storm redevelopment is expected later this
afternoon ahead of the front, but the majority of those storms
should be southeast of the TAF sites. DEC and CMI could get
clipped as the line of storms develops after 20z, so a VCTS was
left in the TAFS from 20z to 01z.
Surface winds will remain out of a southerly direction at 12 to
17 kts early this morning with gusts to 25kt or higher at times
in and near any thunderstorms. Winds will veer more into the
southwest and then west this afternoon with speeds in the 15 to 20 kt
range with gusts up to 30 kts possible, especially if we can get
some sunshine to break through. VFR conditions are expected across
the entire forecast area this evening thru 12z.
Shimon
&&
.PREV DISCUSSION...
ISSUED 312 AM CDT Fri May 9 2014
SHORT TERM...Today through Sunday
Surface map at 06z indicated 999 mb low pressure near KMSP with a
cold front trailing south through central IA and MO then down into
central OK where a weaker 1007 mb low resided. South flow off the
Gulf continued to pump in low to mid 60s dewpoints to central/SE
IL. Aloft, W/V imagery showed a strong warm conveyor belt overhead
which has produced rounds of thunderstorms mainly over eastern IL
for the past few hours. Another shortwave just entering SW MO was
sparking new thunderstorm development and this is expected to
shift northeast across the area through mid-morning as the cold
front moves into the western CWA. Short range models including
HRRR and SPC 4km WRF suggest this activity will push east of the
area by 18z while the cold front gradually tracks ESE across the
CWA. It appears convective debris will clear out by early
afternoon allowing upper 70s temps and mid 60s dewpoints to set up
across the eastern CWA ahead of the front. This would suggest CAPE
values around 2k J/kg with 40 kts 0-6km bulk shear overhead.
Questions remain if new convection will fire along the front as
low level convergence becomes less favorable. Any storms that
develop could become severe with damaging wind gusts and hail
given low wet-bulb zero heights near 9k ft. Radar simulations show
most favored areas would be near or south of I-70 in a 21z-02z
window.
Any lingering activity will shift east of the region overnight as
brief surface ridging moves overhead. This to provide dry and
seasonably warm weather Saturday with highs in the upper 70s/lower
80s. The pattern turns active again Saturday night as warm
advection precip ahead of the next Plains low develops in MO then
lifts northeast across the CWA. Rising heights and another round
of southerly flow ahead of this low should send another strong
warm front north of the area Saturday night or Sunday with more
associated precip chances. With the front now expected north by
Sunday afternoon and with 850 mb temps rising into the mid teens
have boosted highs to the low/mid 80s. Mixed signals if the
warm sector will be dry/capped and as a result chance pops
continue through Sunday night.
LONG TERM...Monday through Thursday
00z model suite still has some major timing differences with a strong
cold frontal passage Monday evening/night. EC continues to be most
consistent and slowest solution. Depending on timing, severe
weather will be a threat given dynamics with this system. Trends
continue to show a major pattern change behind this cold front, as
a deep upper level trough sets up over the central U.S. This will
bring well below normal temps to the region as 850 mb readings are
shown in the low single digits Tue-Thu, suggesting highs mainly
in the 60s as lows in the 40s. With cold air and deep cyclonic
flow overhead, diurnal heating may lead to scattered instability
showers Tue-Thu.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1020 AM EDT FRI MAY 9 2014
.SYNOPSIS...
ISSUED AT 358 AM EDT FRI MAY 9 2014
A LOW PRESSURE SYSTEM WILL MOVE NORTHEAST ACROSS THE UPPER GREAT
LAKES TODAY AND ACROSS ONTARIO TONIGHT. A COLD FRONT TRAILING
SOUTH FROM THE LOW WILL MOVE ACROSS OUR AREA THIS AFTERNOON AND
TONIGHT. OCCASIONAL SHOWERS AND THUNDERSTORMS ARE EXPECTED AHEAD
OF THE COLD FRONT TODAY WITH SCATTERED STORMS POSSIBLY LINGERING
INTO THIS EVENING. HIGHS TODAY WILL BE IN THE MID 70S WITH LOWS
TONIGHT RANGING FROM THE UPPER 40S OVER SOUTHWEST MICHIGAN AND
NORTHWEST INDIANA... TO THE UPPER 50S OVER NORTHWEST OHIO.
&&
.UPDATE...
ISSUED AT 1020 AM EDT FRI MAY 9 2014
LINE OF SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS CURRENTLY
APPROACHING THE AREA...ASSOCIATED WITH A WEAK VORT MAX JUST AHEAD OF
THE MAIN SURFACE COLD FRONT. SPC/RAP MESOANALYSIS SHOWS ALMOST NO
INSTABILITY ACROSS NORTHERN INDIANA...EXPLAINING THE LACK OF RECENT
LIGHTNING. EXPECT THIS WILL CONTINUE TO BE THE CASE THROUGH THE
MORNING WITH OVERCAST SKIES AND SOME LIGHT SHOWERS CONTINUING AHEAD
OF THE MAIN LINE. LATEST RAP13 AND HRRR SHOW ONLY A FEW HUNDRED J/KG
OF SBCAPE THROUGH THE EARLY AFTERNOON. SEVERE WEATHER POTENTIAL WITH
THIS ACTIVITY IS VERY LOW BUT A FEW WIND GUSTS AROUND 40MPH AND SOME
SMALL HAIL WILL BE POSSIBLE GIVEN 850MB WINDS OF 40-50 KNOTS AND
RELATIVELY COLD TEMPS ALOFT/LOW FREEZING LEVELS. HI-RES GUIDANCE
INDICATES THE POTENTIAL FOR A SLIGHT RECOVERY IN OUR WEST AND
SOUTHWEST COUNTIES LATER THIS AFTERNOON WITH MIDLEVEL DRY AIR BEHIND
THE INITIAL SHORTWAVE POSSIBLY ALLOWING FOR A FEW PEAKS OF
SUN...SIMILAR TO CURRENT VIS IMAGERY OVER ILLINOIS. WINDOW OF
OPPORTUNITY FOR SEVERE WEATHER WILL BE SMALL THOUGH AND FORECAST
SBCAPES ARE STILL ONLY AROUND 1000 J/KG...LIMITING UPDRAFT STRENGTH.
WILL BE DIFFICULT TO ADEQUATELY DESTABILIZE AFTER THIS MORNING RAIN.
ONCE AGAIN...STRAIGHT LINE WINDS AND SMALL HAIL WOULD BE THE MAIN
THREATS WITH THE BEST CHANCES PROBABLY IN THE 4-8PM TIMEFRAME BUT
THE SEVERE WEATHER THREAT REMAINS HIGHLY CONDITIONAL AT THIS POINT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM EDT FRI MAY 9 2014
UPR TROF OVER THE PLAINS WILL LIFT NE ACROSS THE GRTLKS AND
DEAMPLIFY TODAY-TNGT. LEAD SHRTWV WILL MOVE ACROSS OUR AREA THIS
MORNING ACCOMPANIED BY A LOW LEVEL THETA-E PLUME/WK INSTABILITY
RESULTING IN WIDESPREAD SHOWERS/TSTMS. MID LEVELS SHOULD DRY OUT IN
WAKE OF THIS LEAD WAVE THIS AFTN... ALLOWING FOR DECREASING
CLOUDINESS AND DESTABILIZATION AS LOW LEVELS REMAIN MOIST AHEAD OF
SFC CDFNT AND APCHG MAIN TROF. NAM SUGGESTS INSTABILITY WILL REACH
AROUND 1500J/KG OVER NRN INDIANA AND SRN MI THIS AFTN WITH 0-6KM
MAINLY UNIDIRECTIONAL SHEAR INCREASING TO AROUND 50KT. THOUGH
FORCING APPEARS FAIRLY WK THIS AFTN AS MOISTURE CONVERGENCE ALONG
CDFNT MINIMAL AND UPR TROF DEAMPLIFING... MODERATE INSTABILITY...
STRONG SHEAR... AND DRY MID LEVELS SUGGEST A POTENTIAL FOR SVR
TSTMS WITH DAMAGING WINDS AND LARGE HAIL... MAINLY ACROSS NRN
INDIANA IF DESTABILIZATION OCCURS AS FCST AND FORCING IS
SUFFICIENT FOR CONVECTION TO DEVELOP DURING PEAK HEATING. CURRENT
TEMPS NEAR PREVIOUS FCST HIGHS FOR TODAY... BUT TEMPS SHOULD RISE
LITTLE THIS MORNING WITH WIDESPREAD SHOWERS MOVG THROUGH AND
CONSIDERABLY COOLER ALOFT THAN YDAY... SO EXPECT HIGHS TODAY
GENERALLY IN THE M70S.
WKNG CDFNT WILL MOVE ACROSS THE AREA TONIGHT PRBLY ACCOMPANIED BY
SCT SHOWERS/TSTMS THIS EVE... WITH CONVECTION DIMINISHING AND MOVG
EAST OVERNIGHT. WK HIGH PRESSURE WILL BUILD INTO THE AREA OVERNIGHT
ALLOWING FOR CLEARING SKIES. SOME PATCHY FOG PSBL ACROSS WRN
PORTIONS OF THE AREA BUT HELD OFF ADDING AT THIS JUNCTURE. TEMPS
WILL BE CONSIDERABLY COOLER WITH LOWS RANGING FROM THE U40S NW TO
THE U50S SE.
&&
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 348 AM EDT FRI MAY 9 2014
LARGE SCALE SUBSIDENCE/DRYING WILL SUPPORT A DRY/COOLER SATURDAY AS
A WEAK AREA OF HIGH PRESSURE BUILDS IN BEHIND FRIDAY NIGHT`S FRONTAL
BOUNDARY. STRENGTHENING SOUTHWEST FLOW IN ADVANCE OF LONGWAVE TROUGH
AMPLIFICATION INTO THE WESTERN US SUNDAY AND HIGH PLAINS EARLY NEXT
WEEK WILL ALLOW GULF MOISTURE TO ADVECT WELL NORTH INTO THE GREAT
LAKES REGION DURING THIS TIME. LOW LEVEL THETA-E GRADIENT/WARM FRONT
IN ADVANCE OF THIS SYSTEM ON LLJ NOSE MAY BRING SOME MAINLY ELEVATED
CONVECTION TO THE AREA (FROM SW TO NE) LATER SATURDAY NIGHT THROUGH
SUNDAY NIGHT...WITH POPS KEPT IN THE LOW/MID CHC RANGE GIVEN THE
ABSENCE OF ANY WELL-DEFINED MID/UPPER LEVEL FORCING.
00Z GUIDANCE CONTINUED THE TREND TOWARD THE SLOWER ECMWF SOLUTION
REGARDING EASTWARD PROGRESSION OF THE UPPER TROUGH NEXT WEEK AS
SYSTEM EVENTUALLY PHASES WITH A CANADIAN PRAIRIES UPPER LOW. THIS
MAY LEAVE THE IWX CWA COMPLETELY IN THE WARM SECTOR BY MONDAY-MONDAY
NIGHT...ALTHOUGH CANNOT RULE OUT PCPN GIVEN MOIST AIRMASS/WEAK
CAPPING AND POTENTIAL FOR WEAK CONVECTIVELY ENHANCED/INDUCED
SHORTWAVES TO LIFT NORTHEAST INTO THE AREA WITHIN SOUTHWEST FLOW.
SHOWER/STORM CHANCES INCREASE AGAIN BY TUESDAY-TUESDAY NIGHT AS
HEIGHT FALLS OVERSPREAD PRE-FRONTAL TROUGH OR COLD FRONT. HELD CLOSE
TO PREV FCST (MID CHC POPS) BUT DID TREND TEMPS UP CLOSER TO WARMER
ECM/MEX MOS AND HPC GUIDANCE MONDAY-TUESDAY. COOLER WX RETURNS
WEDNESDAY INTO THURSDAY IN WAKE OF FRONT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 616 AM EDT FRI MAY 9 2014
SHOWERS WITH SOME EMBEDDED TSTMS EXPECTED TO MOVE ACROSS NRN INDIANA
TODAY. CONDITIONS SHOULD MAINLY BE VFR BUT OCNL MVFR LIKELY DURING
HEAVIER CONVECTION. DRIER AIR IN MID LEVELS WILL SPREAD INTO THE
AREA THIS AFTN RESULTING IN DECREASING CLOUDINESS. TSTMS STILL PSBL
UNTIL WKNG CDFNT MOVES THROUGH THE AREA THIS EVE BUT WITH MAGNITUDE
OF DESTABILIZATION THIS AFTN QUESTIONABLE AND RATHER WK FORCING...
CONTD TO LEAVE TAFS DRY FOR LATE AFTN/EVE. ALTHOUGH LLJ WILL LIFT
NORTH OF THE AREA THIS MORNING... SW WINDS WILL CONT GUSTY AT TIMES
THROUGH THE DAY AS DIURNAL MIXING INCREASES. SOME POTENTIAL FOR BR
DEVELOPMENT OVERNIGHT AS WINDS DIMINISH... ESPECIALLY AT SBN WHERE
POST FRONTAL STRATO CU SHOULD CLEAR OUT LATE... BUT MOISTURE VERY
SHALLOW ON FCST SOUNDINGS SO LEFT MENTION OUT OF TAFS ATTM.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR LMZ043-
046.
&&
$$
UPDATE...AGD
SYNOPSIS...JT
SHORT TERM...JT
LONG TERM...STEINWEDEL
AVIATION...JT
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
513 AM MDT FRI MAY 9 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 258 AM MDT FRI MAY 9 2014
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS
CONFLUENT FLOW ENTERING ROCKIES OVER PLAINS ON BACK SIDE OF
DEPARTING TROUGH...WITH WEAK SHORTWAVE ENERGY UPSTREAM NEAR DIFLUENT
FLOW OVER GREAT BASIN. AT THE SURFACE HIGH PRESSURE IS IN PLACE OVER
OUR CWA WITH STATIONARY FRONT ALONG FRONT RANGING AND COLD FRONT OVER
OK/TX PANHANDLES. RADAR SHOWS SOME VIRGA AND VERY LIGHT SPRINKLES
LINGERING AS A SHORTWAVE IS EJECTING ACROSS THE SOUTHERLY PLAINS.
WITH SUBSIDENCE BUILDING IN FROM THE NORTH THIS ACTIVITY LIKELY WONT
LAST LONG. TEMPS HAVE DROPPED INTO THE MID 30S ACROSS THE WEST...AND
WE COULD SEE A FEW LOW TEMPS AROUND FREEZING BY SUNRISE.
A WEAK SHORTWAVE TROUGH WILL PASS NORTH OF THE CWA THIS AFTERNOON
AND EVENING AND MAY COMBINE WITH AFTERNOON/EVENING INSTABILITY TO
PRODUCE A FEW THUNDERSTORMS OVER NE COLORADO. VERY DRY LOW LEVELS
WOULD LIMIT PRECIP REACHING THE SURFACE. DECIDED TO KEEP SMALL AREA
OF OUR NW CWA WITH ISO THUNDER AROUND 00Z AND OTHERWISE LIMITED
PRECIP MENTION TO SPRINKLES. SEASONAL TEMPS SHOULD RETURN AS SOUTHERLY
FLOW REDEVELOPS TODAY...WITH HIGHS IN THE 70S AND OVERNIGHT LOWS
TONIGHT IN THE LOW-MID 40S (MAYBE A FEW SPOTS A LITTLE COLDER WEST).
SATURDAY-SUNDAY NIGHT...COMPLICATED FORECAST AS THE NEXT STRONG
UPPER TROUGH IS EXPECTED TO IMPACT THE CENTRAL ROCKIES AND PLAINS.
SOUTHWESTERLY FLOW DEVELOPS ACROSS THE ROCKIES WHICH WOULD
INITIALLY LIMIT ANY SHOWER/THUNDERSTORM CHANCES TO THE NW
SATURDAY. HOWEVER BY SATURDAY NIGHT THE MAIN TROUGH BEGINS TO SLIDE
EAST ALLOWING GOOD MOISTURE AND LIFT OT BUILD OVER THE CWA. BEST
PRECIP CHANCES ACROSS THE CWA STILL LOOKS TO BE ON SUN/SUN NIGHT AND
MODELS SHOW REASONABLE AGREEMENT ON MEASURABLE PRECIP SO I BUMP
POPS INTO 60-70 RANGE FOR THOSE PERIODS. A LITTLE LESS CONFIDENT ON
AREA OF BEST PRECIP...THOUGH PARTS OF THE REGION (ESPECIALLY WEST)
COULD SEE DECENT LIQUID ACCUMULATION WITH THIS EVENT (0.15-0.75").
REGARDING WEATHER TYPE...VERY LIMITED INSTABILITY THROUGH MOST OF THE
EVENT...SO ONLY KEPT THUNDER MENTION SATURDAY AFTERNOON/EVENING.
TEMP PROFILES AND WBZ HEIGHTS WOULD INDICATE A RAIN/SNOW MIX OR A
COMPLETE CHANGEOVER ACROSS THE WESTERN HALF OF THE CWA SUNDAY NIGHT.
WARM GROUND TEMPS MAY LIMIT ANY SNOW ACCUMULATION (ASSUMING LIGHTER
RATES). IN ADDITION TO WARM GROUND TEMPS...CONFIDENCE OF CHANGEOVER
TIMING IS LOW SO I LEFT ACCUMULATION MENTION OUT OF FORECAST. I DID
INCLUDE RAIN/SNOW MENTION AND A BRIEF PERIOD OF ALL SNOW AROUND
SUNRISE EARLY MONDAY MORNING. WILL NEED TO WATCH HOW THIS SYSTEM
EVOLVES TO ZERO IN ON THESE DETAILS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 258 AM MDT FRI MAY 9 2014
MODELS ARE STILL IN DISAGREEMENT WITH THE POSITION AND PROGRESSION
OF THE UPPER LEVEL TROUGH IN THE EXTENDED. GFS STILL MOVES IT
FURTHER EAST MORE QUICKLY THAN THE ECMWF. HOWEVER...THE TROUGH WILL
CONTINUE TO INFLUENCE THE CWA ON MONDAY. TEMPERATURES MONDAY MORNING
APPEAR COLD ENOUGH FOR LIGHT SNOW TO CONTINUE OVER EASTERN COLORADO
WITH A RAIN SNOW MIX IN NORTHWEST KANSAS IN COUNTIES BORDERING
EASTERN COLORADO. TEMPERATURES SHOULD WARM ENOUGH BY 15Z FOR ALL
PRECIPITATION TO BE RAIN...WITH THE CHANCE FOR RAIN CONTINUING
MONDAY AFTERNOON. MONDAY WILL REMAIN BREEZY AS THE TIGHT PRESSURE
GRADIENT STAYS OVER THE CWA UNTIL MONDAY NIGHT WHEN IT RELAXES AND
SURFACE HIGH PRESSURE SETTLES IN OVER COLORADO. TUESDAY THROUGH
WEDNESDAY SHOULD REMAIN DRY AS THE UPPER LEVEL RIDGE OVER THE
WESTERN UNITED STATES BECOMES MORE INFLUENTIAL IN THE HIGH PLAINS.
BY THURSDAY...A SHORTWAVE TROUGH WILL ROTATE AROUND THE UPPER TROUGH
OVER THE GREAT LAKES REGION SENDING A WEAK COLD FRONT THROUGH THE
CWA. SHOWERS AND THUNDERSTORMS COULD DEVELOP AHEAD OF THE
FRONT...SINCE THE GFS DOES HAVE A FEW HUNDRED J/KG OF CAPE OVER
EASTERN COLORADO. AS PREVIOUSLY MENTIONED...THE MODELS ARE HAVING A
HARD TIME COMING TO A CONSENSUS FOR ANY DAY IN THE EXTENDED...SO AM
TRYING TO GET AWAY FROM GETTING TOO DETAILED FOR THUNDERSTORM
POTENTIAL IN DAY 7.
WELL BELOW AVERAGE TEMPERATURES CAN BE EXPECTED TO START OFF THE
EXTENDED PERIOD WITH HIGHS ON MONDAY IN THE LOW TO UPPER 50S. LOWS
MONDAY NIGHT WILL BE IN THE LOW 30S TO LOW 40S WITH HIGHS ON TUESDAY
IN THE LOW TO MID 60S. SLIGHTLY BELOW TO NEAR NORMAL TEMPERATURES
WILL TAKE OVER THROUGH THE REST OF THE EXTENDED WITH HIGHS IN THE
MID 60S TO LOW 70S ON WEDNESDAY AND THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 512 AM MDT FRI MAY 9 2014
VFR CONDITIONS WILL PREVAIL AT BOTH KGLD AND KMCK TERMINALS
THROUGH THE TAF PERIOD. SW WINDS WILL INCREASE SLIGHTLY TO BE
AROUND 12-15KT DURING THE DAYTIME PERIOD. AFTER SUNSET LIGHT AND
VARIABLE WINDS ARE THEN EXPECTED UNTIL WINDS SHIFT TO THE WEST AND
INCREASE BACK TO THE 10-15KT RANGE BEHIND A QUICK MOVING FRONT.
A FEW THUNDERSTORMS MAY DEVELOP THIS AFTERNOON AND
EVENING AS A WEAK DISTURBANCE MOVES THROUGH THE REGION...HOWEVER
ANY THUNDERSTORM ACTIVITY SHOULD REMAIN WELL NORTHWEST OF BOTH
TERMINALS. THERE COULD STILL BE VIRGA OR EVEN A FEW LIGHT SHOWERS
AT BOTH TERMINALS...HOWEVER CONFIDENCE IS TOO LOW TO INCLUDE VCSH
DURING THIS TAF UPDATE.
&&
.FIRE WEATHER...
ISSUED AT 243 AM MDT FRI MAY 9 2014
WITH WARMER TEMPS AND LOWER TD MIXING TO THE SURFACE
WE COULD SEE RH VALUES WITHIN RFW CRITERIA ACROSS THE SOUTHERN PART
OF OUR FORECAST AREA BOTH TODAY AND SATURDAY AFTERNOON/EARLY EVENING
PERIODS. TODAY WINDS WILL BE WELL BELOW CRITERIA WITH WEAK GRADIENT
IN PLACE...SO NO RFW PRODUCT ANTICIPATED. SW PRESSURE GRADIENT BEGINS
TO INCREASE SATURDAY AHEAD OF DEEPENING UPPER LOW...THOUGH EVOLUTION
OF SURFACE LOW AND FRONT POSITION WILL BE CRITICAL FOR WHERE WINDS
WITHIN RFW CRITERIA WILL CROSS WITH LOW RH. NOT ENOUGH CONFIDENCE AT
THIS POINT TO ISSUE A FIRE WEATHER WATCH FOR SATURDAY...BUT WE WILL
PROBABLY NEED TO MONITOR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...ALW
AVIATION...DR
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1153 AM EDT Fri May 9 2014
...Forecast Update...
Issued at 1145 AM EDT Fri May 9 2014
Band of showers continues to progress northeast over central KY at
this time. There has not been any thunderstorms in this area so far,
although latest Doppler radar is now showing increasing reflectivity
values over parts of central KY, some expect isolated/scattered
embedded cells early this afternoon as the rain continues pushing
east. The rain will exit our eastern forecast area by 19z or so.
After the rain ends, dry weather should prevail for a few hours this
afternoon over central KY and south-central IN given the absence of
enough forcing and initial instability.
In the wake of this rain, clouds should thin with some breaks of
sun, which should allow temperatures to reach near/around 80 in our
western forecast area. Low-level warming combined with increasing
mid-level lapse rates will increase instability over the lower OH
Valley this afternoon as shown nicely by latest model soundings.
Already, scattered cells are developing in central MO near frontal
zone, although these should move northeast later today and initially
not affect our area. Nevertheless, with increasing instability and
potential diurnal heating boundaries, at least scattered convection
should also develop later this afternoon just to out west and move
into central KY and southern IN late this afternoon/evening.
No major changes to tonight`s forecast at this time.
Issued at 915 AM EDT Fri May 9 2014
An elongated axis of showers with a couple embedded bands of
moderate to heavy rain and possibly an embedded elevated thunder-
storm is moving northeast quickly this morning over west-central KY,
now moving through our western forecast area. 06z model runs along
with latest high-resolution HRRR model show that this axis should
move steadily but coherently through our forecast area for the rest
of this morning into early afternoon, before exiting to our east.
Thus, have raised rainfall probabilities across our entire area.
After this rain passes by, precip will end and then the question
arises about what will happen later this afternoon. Still looks like
some diurnal heating will commence with the atmosphere becoming more
unstable. Models show that scattered convection could develop to our
west this afternoon and then move east into our area later this
afternoon and tonight. This scenario still seems reasonable,
although am not able to pin things down more specifically at this
time yet. Will continue to monitor trends through the day. No
change to temperatures for today at this time. Will evaluate this
later this morning into early afternoon.
Issued at 640 AM EDT Fri May 9 2014
Did a quick update to back off PoPs a bit in the east this morning,
but also increase PoPs slightly across our west and northwestern
areas. Based on latest radar trends, expect a band of showers to
affect portions of southern Indiana and Kentucky west of I-65 this
morning. Expect this activity to diminish in intensity and coverage
as it heads into a slightly drier and more stable airmass. Also
backed off coverage this afternoon a bit given that overall model
solutions are trending a bit drier. Likely PoPs appear to be too
aggressive at this time and have backed them off into the scattered
category. Also bumped temperatures in the west up slightly based on
the assumption of lesser precipitation.
.SHORT TERM (Now through Saturday)...
Issued at 315 AM EDT Fri May 9 2014
In the near term, partly to mostly cloudy skies will be the rule
across southern Indiana and central Kentucky this morning. Early
morning IR imagery shows plenty of high level cloudiness streaming
in from the west. Area radars are rather quiet across central KY
but there are some returns back over southeastern Missouri that are
heading eastward. We expect dry conditions for the remainder of the
early morning hours. Temperatures remain quite mild with readings
generally in the upper 60s to the lower 70s. Some of our cooler
spots appear to have decoupled a bit and are seeing temperatures
down into the upper 50s to around 60. We expect temperatures to
slowly drop a few more degrees before rebounding towards sunrise.
For Today, local and national high resolution modeling suggest area
of convection across southeastern Missouri and northeastern Arkansas
will grow upscale early this morning in response to a moderate
low-level jet axis impinging northeastward into lower Mississippi
Valley. This convection will work eastward during the morning hours
and weaken a bit as it heads into central Kentucky. Persistent
cloud cover and the remnants of this convective activity will likely
keep instability down to marginal levels across the region. That is
not to say that some areas may see stronger convection develop this
afternoon. As the morning convection heads off to the east, we may
see a few breaks develop which could lead to the development of
pockets of higher instability during the afternoon. The best
chances of this occurring would be out across the western areas.
Overall, we still do not believe today will be a total washout.
Though areas that do receive rain could get a nice soaking as the
showers and storms move through the region. Highs today look to
range from the middle to upper 70s in the west with upper 70s to
lower 80s in the east.
As we move into the evening hours, the higher resolution models do
show a secondary line of storms forming along the frontal boundary
approaching from the northwest. These storms probably will fire
along a line from Indianapolis to St. Louis early this evening and
then spread eastward into our region during the overnight period.
Depending on how fast the early morning activity clears the region
will be a determining factor in how strong the evening/overnight
convection will be. With the line expected to come through at the
time of minimum heating, we are not overly impressed with severe
potential. Strong storms are certainly possible with damaging winds
and hail being the primary threats. The activity should clear our
region by early Saturday morning with temperatures only cooling into
the mid-upper 60s.
For Saturday, skies will likely start off mostly cloudy and then
begin to clear from the west towards the east. While the upper flow
takes on more of zonal pattern, there is difficulty in determining
any real triggers for convection. Isolated-scattered convection
will be possible with the highest concentration out toward the
eastern portions of the forecast area. Though, by and large most
areas will probably see mainly dry conditions. Highs for Saturday
will be largely dependent on cloud cover during the afternoon. The
multi-model consensus suggests highs in the upper 70s to near 80 in
the west with mainly mid-upper 70s in the east.
.LONG TERM (Saturday Night through Thursday)...
Issued at 319 PM EDT Thu May 8 2014
As previously advertised, the Ohio Valley will be entering into an
active pattern with showers and thunderstorms in the forecast for
nearly every day in this period. Synoptically, Saturday will undergo
a transition to more zonal at the 500mb level as the disturbance
that brings rain to the region Friday night moves off toward the
east. The forecast challenge for Saturday is how quickly the storms
exit the forecast area as the deterministic models are struggling to
come into better agreement. The trend has been just a bit slower, as
evident from comparing previous runs with the 12Z runs. The NAM has
been the quickest and conversely, the GFS messy and the slowest. The
09Z SREF seems to be the better compromise and have leaned toward it
to show a general partial clearing from west to east throughout the
day.
Through the remainder of the weekend, much of Saturday night should
be dry before the atmosphere recharges ahead of the next system.
We`ll remain under southerly flow with high pressure centered over
the Atlantic, allowing for GoMex moisture to pool into the region.
Under this warm , moist air advection regime, Sunday`s forecast is
also a bit tricky as we could see some sporadic storms firing up,
especially with diurnal heating throughout the day. There is no
obvious signal for which portions of the forecast area will see
better rain chances than others given this type of setup so have
broad brushed low-end chance PoPs throughout. After the sun sets on
Sunday, should see a wane in storm coverage with the loss of the
aforementioned heating. Something to watch for, however, is that the
12Z NAM is hinting at a mesoscale convective system to build across
eastern KS/central MO and race off into the Great Lakes region late
Saturday night through Sunday. This is in response to a surface low
that develops just behind it. The NAM is depicting the eastern
portion of this system to break off and jet across central KY before
dying out as it loses its forcing mechanism. We`ll have to see how
this evolves as we approach that time frame.
As if the models haven`t been struggling enough, true temporal
divergence becomes evident early next week as an amplified pattern
sets up: troughing across the Plains and ridging over the East
Coast. The GFS has been consistently fast with the ECMWF much
slower. Have attempted to blend and compromise between the two,
coming to the uncertain conclusion that Tuesday looks to be the best
chance for active weather across the area. One thing the models do
agree on is the pattern change coming by the middle to end of next
week.
Given the unsettled nature of the upcoming pattern, temperature
forecasts will be difficult to nail down with certainty, with clouds
potentially wrecking havoc on the highs/lows. However, taking into
consideration the type of airmasses we`ll be under, along with climo
for this time of year, the warmest days of the long-term period will
be Sunday and Monday, with Saturday and Tuesday being slightly
cooler, and Wednesday onward dropping well below normal. This
forecast update will show highs in the upper 70s on Saturday as
clouds and precip exit; highs in the lower 80s Sunday - Monday under
southerly flow/WAA; Tuesday in the mid to upper 70s with stormy
conditions; and 60s Wednesday - Thursday. Look for lows to respond
accordingly with 60s Saturday night - Monday night and flirting with
the 50 degree mark Tuesday night - Wednesday night.
&&
.AVIATION (12Z TAF Update)...
Issued at 635 AM EDT Fri May 9 2014
A surface cold front will push eastward toward the region today.
Abundant high cloud cover will continue to advect eastward across
the terminals today producing high ceilings. Scattered showers over
western KY will continue to move east and may affect KSDF and KBWG
by mid to late morning. Stronger aviation concern that will emerge
this morning will be the increase in southwesterly winds at the
terminals. We expect winds to pick up around 09/14Z or so with
sustained winds of 12-16kts and gusts up to 20kts. Scattered
convection is expected to further develop this afternoon and evening
as the frontal boundary gets closer to the region. VFR conditions
are expected to prevail at the terminals, but some temporary MVFR
cigs within passing convection will be possible. Overall convective
coverage should diminish toward sunset, but a secondary line of
convection may develop out to the west and affect the terminals
after 10/02Z.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........TWF
Short Term.....MJ
Long Term......BJS
Aviation.......MJ
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
926 AM EDT Fri May 9 2014
...Forecast Update...
Issued at 915 AM EDT Fri May 9 2014
An elongated axis of showers with a couple embedded bands of
moderate to heavy rain and possibly an embedded elevated thunder-
storm is moving northeast quickly this morning over west-central KY,
now moving through our western forecast area. 06z model runs along
with latest high-resolution HRRR model show that this axis should
move steadily but coherently through our forecast area for the rest
of this morning into early afternoon, before exiting to our east.
Thus, have raised rainfall probabilities across our entire area.
After this rain passes by, precip will end and then the question
arises about what will happen later this afternoon. Still looks like
some diurnal heating will commence with the atmosphere becoming more
unstable. Models show that scattered convection could develop to our
west this afternoon and then move east into our area later this
afternoon and tonight. This scenario still seems reasonable,
although am not able to pin things down more specifically at this
time yet. Will continue to monitor trends through the day. No
change to temperatures for today at this time. Will evaluate this
later this morning into early afternoon.
Issued at 640 AM EDT Fri May 9 2014
Did a quick update to back off PoPs a bit in the east this morning,
but also increase PoPs slightly across our west and northwestern
areas. Based on latest radar trends, expect a band of showers to
affect portions of southern Indiana and Kentucky west of I-65 this
morning. Expect this activity to diminish in intensity and coverage
as it heads into a slightly drier and more stable airmass. Also
backed off coverage this afternoon a bit given that overall model
solutions are trending a bit drier. Likely PoPs appear to be too
aggressive at this time and have backed them off into the scattered
category. Also bumped temperatures in the west up slightly based on
the assumption of lesser precipitation.
.SHORT TERM (Now through Saturday)...
Issued at 315 AM EDT Fri May 9 2014
In the near term, partly to mostly cloudy skies will be the rule
across southern Indiana and central Kentucky this morning. Early
morning IR imagery shows plenty of high level cloudiness streaming
in from the west. Area radars are rather quiet across central KY
but there are some returns back over southeastern Missouri that are
heading eastward. We expect dry conditions for the remainder of the
early morning hours. Temperatures remain quite mild with readings
generally in the upper 60s to the lower 70s. Some of our cooler
spots appear to have decoupled a bit and are seeing temperatures
down into the upper 50s to around 60. We expect temperatures to
slowly drop a few more degrees before rebounding towards sunrise.
For Today, local and national high resolution modeling suggest area
of convection across southeastern Missouri and northeastern Arkansas
will grow upscale early this morning in response to a moderate
low-level jet axis impinging northeastward into lower Mississippi
Valley. This convection will work eastward during the morning hours
and weaken a bit as it heads into central Kentucky. Persistent
cloud cover and the remnants of this convective activity will likely
keep instability down to marginal levels across the region. That is
not to say that some areas may see stronger convection develop this
afternoon. As the morning convection heads off to the east, we may
see a few breaks develop which could lead to the development of
pockets of higher instability during the afternoon. The best
chances of this occurring would be out across the western areas.
Overall, we still do not believe today will be a total washout.
Though areas that do receive rain could get a nice soaking as the
showers and storms move through the region. Highs today look to
range from the middle to upper 70s in the west with upper 70s to
lower 80s in the east.
As we move into the evening hours, the higher resolution models do
show a secondary line of storms forming along the frontal boundary
approaching from the northwest. These storms probably will fire
along a line from Indianapolis to St. Louis early this evening and
then spread eastward into our region during the overnight period.
Depending on how fast the early morning activity clears the region
will be a determining factor in how strong the evening/overnight
convection will be. With the line expected to come through at the
time of minimum heating, we are not overly impressed with severe
potential. Strong storms are certainly possible with damaging winds
and hail being the primary threats. The activity should clear our
region by early Saturday morning with temperatures only cooling into
the mid-upper 60s.
For Saturday, skies will likely start off mostly cloudy and then
begin to clear from the west towards the east. While the upper flow
takes on more of zonal pattern, there is difficulty in determining
any real triggers for convection. Isolated-scattered convection
will be possible with the highest concentration out toward the
eastern portions of the forecast area. Though, by and large most
areas will probably see mainly dry conditions. Highs for Saturday
will be largely dependent on cloud cover during the afternoon. The
multi-model consensus suggests highs in the upper 70s to near 80 in
the west with mainly mid-upper 70s in the east.
.LONG TERM (Saturday Night through Thursday)...
Issued at 319 PM EDT Thu May 8 2014
As previously advertised, the Ohio Valley will be entering into an
active pattern with showers and thunderstorms in the forecast for
nearly every day in this period. Synoptically, Saturday will undergo
a transition to more zonal at the 500mb level as the disturbance
that brings rain to the region Friday night moves off toward the
east. The forecast challenge for Saturday is how quickly the storms
exit the forecast area as the deterministic models are struggling to
come into better agreement. The trend has been just a bit slower, as
evident from comparing previous runs with the 12Z runs. The NAM has
been the quickest and conversely, the GFS messy and the slowest. The
09Z SREF seems to be the better compromise and have leaned toward it
to show a general partial clearing from west to east throughout the
day.
Through the remainder of the weekend, much of Saturday night should
be dry before the atmosphere recharges ahead of the next system.
We`ll remain under southerly flow with high pressure centered over
the Atlantic, allowing for GoMex moisture to pool into the region.
Under this warm , moist air advection regime, Sunday`s forecast is
also a bit tricky as we could see some sporadic storms firing up,
especially with diurnal heating throughout the day. There is no
obvious signal for which portions of the forecast area will see
better rain chances than others given this type of setup so have
broad brushed low-end chance PoPs throughout. After the sun sets on
Sunday, should see a wane in storm coverage with the loss of the
aforementioned heating. Something to watch for, however, is that the
12Z NAM is hinting at a mesoscale convective system to build across
eastern KS/central MO and race off into the Great Lakes region late
Saturday night through Sunday. This is in response to a surface low
that develops just behind it. The NAM is depicting the eastern
portion of this system to break off and jet across central KY before
dying out as it loses its forcing mechanism. We`ll have to see how
this evolves as we approach that time frame.
As if the models haven`t been struggling enough, true temporal
divergence becomes evident early next week as an amplified pattern
sets up: troughing across the Plains and ridging over the East
Coast. The GFS has been consistently fast with the ECMWF much
slower. Have attempted to blend and compromise between the two,
coming to the uncertain conclusion that Tuesday looks to be the best
chance for active weather across the area. One thing the models do
agree on is the pattern change coming by the middle to end of next
week.
Given the unsettled nature of the upcoming pattern, temperature
forecasts will be difficult to nail down with certainty, with clouds
potentially wrecking havoc on the highs/lows. However, taking into
consideration the type of airmasses we`ll be under, along with climo
for this time of year, the warmest days of the long-term period will
be Sunday and Monday, with Saturday and Tuesday being slightly
cooler, and Wednesday onward dropping well below normal. This
forecast update will show highs in the upper 70s on Saturday as
clouds and precip exit; highs in the lower 80s Sunday - Monday under
southerly flow/WAA; Tuesday in the mid to upper 70s with stormy
conditions; and 60s Wednesday - Thursday. Look for lows to respond
accordingly with 60s Saturday night - Monday night and flirting with
the 50 degree mark Tuesday night - Wednesday night.
&&
.AVIATION (12Z TAF Update)...
Issued at 635 AM EDT Fri May 9 2014
A surface cold front will push eastward toward the region today.
Abundant high cloud cover will continue to advect eastward across
the terminals today producing high ceilings. Scattered showers over
western KY will continue to move east and may affect KSDF and KBWG
by mid to late morning. Stronger aviation concern that will emerge
this morning will be the increase in southwesterly winds at the
terminals. We expect winds to pick up around 09/14Z or so with
sustained winds of 12-16kts and gusts up to 20kts. Scattered
convection is expected to further develop this afternoon and evening
as the frontal boundary gets closer to the region. VFR conditions
are expected to prevail at the terminals, but some temporary MVFR
cigs within passing convection will be possible. Overall convective
coverage should diminish toward sunset, but a secondary line of
convection may develop out to the west and affect the terminals
after 10/02Z.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........TWF/MJ
Short Term.....MJ
Long Term......BJS
Aviation.......MJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
754 AM EDT FRI MAY 9 2014
.UPDATE...
ISSUED AT 709 AM EDT FRI MAY 9 2014
UPDATED GRIDS FOR LATEST TRENDS...MAINLY IN RADAR RETURNS. SEEING
AN OCCASIONAL 35 TO 45 DBZ ECHO WITHIN A BAND MOVING UP FROM THE
SOUTHWEST. AT THAT STRENGTH EXPECT THERE SHOULD BE SOME LIGHT
RAINFALL REACHING THE GROUND. MORE ISOLD CELLS ARE APPEARING FURTHER
SOUTHWEST BUT MOVING NORTHEASTWARD AT A QUICK PACE. HRRR HAS A GOOD
HANDLE ON THIS. BOTTOM LINE...BROUGHT POPS IN A BIT QUICKER THROUGH
THE DAY. OTHERWISE, NO MAJOR CHANGES TO THE FORECAST ATTM.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 339 AM EDT FRI MAY 9 2014
FORECASTING THUNDER REMAINS A CHALLENGE AS THE LATEST RUN OF THE RAP
HAS INCREASED SFC DEW POINTS CONSIDERABLY FROM JUST A FEW HOURS
EARLIER FOR THIS AFTERNOON. STILL CAN NOT HELP BUT TO BELIEVE MODELS
ARE OVER DOING MOISTURE BASED ON RECENT HISTORY IF NOTHING ELSE. EVEN
THE NAM...WITH ITS TYPICALLY OVERDONE SFC DEW POINTS IS ADVERTISING
NOTHING MORE THAN SCATTERED THUNDER. IN ADDITION...LATEST RUN OF THE
HRRR SUGGEST THE STRONGEST CONVECTION WILL REMAIN SOUTH OF OUR AREA
IN TN. HAVE DECIDED TO GO WITH JUST A CHANCE OF THUNDER FOR TODAY.
WITH RELATIVELY DRIER BOUNDARY LAYER STILL EXPECT ANY SHOWERS AND/OR
THUNDERSTORMS THAT DEVELOP WILL TEND TO BE HIGH BASED AND PRODUCE
GUSTY WINDS.
THE THREAT OF UNSETTLED WEATHER CONTINUES THROUGH THE REMAINDER OF
THE SHORT TERM. HAVE NOTICED WITH THE LATEST MODEL RUNS THAT THE
FRONTAL BOUNDARY BECOMES MORE DIFFUSE WITH TIME...EVEN TO THE POINT
OF POSSIBLY WASHING OUT SOMEWHERE OVER THE REGION BY SATURDAY. WITH
REMNANTS OF THE BOUNDARY IN THE AREA...AND BETTER SURFACE MOISTURE TO
WORK WITH TONIGHT AND SATURDAY WILL GENERALLY MAINTAIN INHERITED POPS
THROUGH THE PERIOD. OTHERWISE...NUDGED TEMPS TOWARDS LATEST BLEND OF
MODEL/GUIDANCE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 339 AM EDT FRI MAY 9 2014
A VERY UNCERTAIN LONG TERM PERIOD SETTING UP THROUGH NEXT WEEK.
STRONG MID TO UPPER LEVEL RIDGING WILL REMAIN ANCHORED OVER THE
EASTERN US THROUGH TUESDAY. HOWEVER...MODELS ARE SHOWING SOME SUBTLE
WAVES PUSHING THROUGH THE RIDGE AXIS AT TIMES. FEEL THESE WAVES MAY
BE OVER PRONOUNCED IN THE MODELS GIVEN THE IMPRESSIVE HEIGHTS OVER
THE AREA. HOWEVER...GIVEN THE WARMTH...AND SLIGHTLY BETTER SFC
MOISTURE INTO EARLY THIS WEEK...IT IS POSSIBLE WE COULD SEE A SHOWER
OR THUNDERSTORM EACH AFTERNOON OR EARLY EVENING. CERTAINLY DOESN`T
LOOK LIKE A WASH OUT BY ANY MEANS...BUT THE SMALL THREAT IS THERE.
IT APPEARS THE BETTER CHANCES FOR SHOWERS AND STORMS WILL COME
MIDWEEK AS A STRONG COLD FRONT MARCHES EAST ACROSS THE AREA. MODELS
REMAIN IN STARK CONTRAST WITH REGARDS TO TIMING THIS FEATURE ACROSS
THE AREA...SO HAVE GONE WITH A PERIOD OF HIGHER POPS FROM TUESDAY
NIGHT THROUGH WEDNESDAY EVENING. MOST LIKELY THE PERIOD OF UNSETTLED
WEATHER WILL BE MUCH MORE NARROW THAN THIS WINDOW. IT DOES APPEAR
THE WEATHER SHOULD TURN COOL AND DRIER BY THURSDAY...BUT AN UPPER
LEVEL TROUGH MAY BRING SOME UNSETTLED WEATHER BACK TO THE AREA BY
WEEKS END. GIVEN THE UNCERTAINTY WITH PRECIPITATION CHANCES THIS
WEEK...HAVE GONE WITH ASSUMPTION...MOST DAYS WILL FEATURE DRY
WEATHER AND THUS...WARMER TEMPERATURES...AT LEAST THROUGH TUESDAY.
BY WEDNESDAY...TEMPERATURES WILL START TO TAKE A STEP
DOWNWARDS...AND CERTAINLY BY WEDNESDAY WITH HIGHS LIKELY BACK INTO
THE 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 754 AM EDT FRI MAY 9 2014
IN GENERAL EXPECTING VFR CONDITIONS THROUGH THE ENTIRE FORECAST
PERIOD.
RADAR SHOWING SOME ISOLATED SHOWERS ALREADY ENTERING THE AREA THIS
MORNING. MORE SCATTERED SHOWERS TO THE SOUTHWEST...AND A LARGER BAND
OF RAIN WHICH WILL BE MOVING INTO THE AREA AS THE DAY PROGRESSES.
FORECAST SOUNDINGS NOT THE MOST FAVORABLE FOR THUNDER TODAY WITH
RELATIVELY DRY LOWER LEVELS AND MOSTLY CLOUDY SKIES HELPING TO KEEP
TEMPERATURES...SURFACE BASED INSTABILITY DOWN A BIT. BUT CAN NOT
RULE OUT THUNDER ALTOGETHER. FOR NOW PLAYED DOWN THUNDER IN THE TAFS
UNTIL TONIGHT WHERE SOUNDINGS LOOK MORE UNSTABLE GOING INTO SATURDAY
MORNING DUE TO A SURFACE FRONTAL BOUNDARY MAKING AN HONEST PUSH
TOWARDS OUR AREA AND AS MOISTURE INCREASES AT THE SURFACE AHEAD OF
THIS SYSTEM. FOR NOW IT APPEARS THIS FRONT WILL STALL AND WASH OUT
SOMETIME SATURDAY.
WINDS WILL GENERALLY INCREASE FROM THE SOUTH...SOUTHWEST AT 10-15 KTS
THROUGH THE DAY WITH AN OCCASIONAL HIGHER GUST. HOWEVER...WITH
RELATIVELY DRIER LOW LEVELS WINDS COULD BE VARIABLE AND GUSTY AROUND
ANY SHOWERS AND THUNDERSTORMS THAT DO DEVELOP. GUSTY WIND THREAT
ASSOCIATED WITH SHOWERS AND ANY THUNDERSOTRMS WILL ABATE AS RAINFALL
MOISTENS UP THE LOWER LEVELS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...RAY
LONG TERM...KAS
AVIATION...RAY
AREA FORECAST DISCUSSION
NWS JACKSON KY
709 AM EDT FRI MAY 9 2014
.UPDATE...
ISSUED AT 709 AM EDT FRI MAY 9 2014
UPDATED GRIDS FOR LATEST TRENDS...MAINLY IN RADAR RETURNS. SEEING
AN OCCASIONAL 35 TO 45 DBZ ECHO WITHIN A BAND MOVING UP FROM THE
SOUTHWEST. AT THAT STRENGTH EXPECT THERE SHOULD BE SOME LIGHT
RAINFALL REACHING THE GROUND. MORE ISOLD CELLS ARE APPEARING FURTHER
SOUTHWEST BUT MOVING NORTHEASTWARD AT A QUICK PACE. HRRR HAS A GOOD
HANDLE ON THIS. BOTTOM LINE...BROUGHT POPS IN A BIT QUICKER THROUGH
THE DAY. OTHERWISE, NO MAJOR CHANGES TO THE FORECAST ATTM.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 339 AM EDT FRI MAY 9 2014
FORECASTING THUNDER REMAINS A CHALLENGE AS THE LATEST RUN OF THE RAP
HAS INCREASED SFC DEW POINTS CONSIDERABLY FROM JUST A FEW HOURS
EARLIER FOR THIS AFTERNOON. STILL CAN NOT HELP BUT TO BELIEVE MODELS
ARE OVER DOING MOISTURE BASED ON RECENT HISTORY IF NOTHING ELSE. EVEN
THE NAM...WITH ITS TYPICALLY OVERDONE SFC DEW POINTS IS ADVERTISING
NOTHING MORE THAN SCATTERED THUNDER. IN ADDITION...LATEST RUN OF THE
HRRR SUGGEST THE STRONGEST CONVECTION WILL REMAIN SOUTH OF OUR AREA
IN TN. HAVE DECIDED TO GO WITH JUST A CHANCE OF THUNDER FOR TODAY.
WITH RELATIVELY DRIER BOUNDARY LAYER STILL EXPECT ANY SHOWERS AND/OR
THUNDERSTORMS THAT DEVELOP WILL TEND TO BE HIGH BASED AND PRODUCE
GUSTY WINDS.
THE THREAT OF UNSETTLED WEATHER CONTINUES THROUGH THE REMAINDER OF
THE SHORT TERM. HAVE NOTICED WITH THE LATEST MODEL RUNS THAT THE
FRONTAL BOUNDARY BECOMES MORE DIFFUSE WITH TIME...EVEN TO THE POINT
OF POSSIBLY WASHING OUT SOMEWHERE OVER THE REGION BY SATURDAY. WITH
REMNANTS OF THE BOUNDARY IN THE AREA...AND BETTER SURFACE MOISTURE TO
WORK WITH TONIGHT AND SATURDAY WILL GENERALLY MAINTAIN INHERITED POPS
THROUGH THE PERIOD. OTHERWISE...NUDGED TEMPS TOWARDS LATEST BLEND OF
MODEL/GUIDANCE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 339 AM EDT FRI MAY 9 2014
A VERY UNCERTAIN LONG TERM PERIOD SETTING UP THROUGH NEXT WEEK.
STRONG MID TO UPPER LEVEL RIDGING WILL REMAIN ANCHORED OVER THE
EASTERN US THROUGH TUESDAY. HOWEVER...MODELS ARE SHOWING SOME SUBTLE
WAVES PUSHING THROUGH THE RIDGE AXIS AT TIMES. FEEL THESE WAVES MAY
BE OVER PRONOUNCED IN THE MODELS GIVEN THE IMPRESSIVE HEIGHTS OVER
THE AREA. HOWEVER...GIVEN THE WARMTH...AND SLIGHTLY BETTER SFC
MOISTURE INTO EARLY THIS WEEK...IT IS POSSIBLE WE COULD SEE A SHOWER
OR THUNDERSTORM EACH AFTERNOON OR EARLY EVENING. CERTAINLY DOESN`T
LOOK LIKE A WASH OUT BY ANY MEANS...BUT THE SMALL THREAT IS THERE.
IT APPEARS THE BETTER CHANCES FOR SHOWERS AND STORMS WILL COME
MIDWEEK AS A STRONG COLD FRONT MARCHES EAST ACROSS THE AREA. MODELS
REMAIN IN STARK CONTRAST WITH REGARDS TO TIMING THIS FEATURE ACROSS
THE AREA...SO HAVE GONE WITH A PERIOD OF HIGHER POPS FROM TUESDAY
NIGHT THROUGH WEDNESDAY EVENING. MOST LIKELY THE PERIOD OF UNSETTLED
WEATHER WILL BE MUCH MORE NARROW THAN THIS WINDOW. IT DOES APPEAR
THE WEATHER SHOULD TURN COOL AND DRIER BY THURSDAY...BUT AN UPPER
LEVEL TROUGH MAY BRING SOME UNSETTLED WEATHER BACK TO THE AREA BY
WEEKS END. GIVEN THE UNCERTAINTY WITH PRECIPITATION CHANCES THIS
WEEK...HAVE GONE WITH ASSUMPTION...MOST DAYS WILL FEATURE DRY
WEATHER AND THUS...WARMER TEMPERATURES...AT LEAST THROUGH TUESDAY.
BY WEDNESDAY...TEMPERATURES WILL START TO TAKE A STEP
DOWNWARDS...AND CERTAINLY BY WEDNESDAY WITH HIGHS LIKELY BACK INTO
THE 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 205 AM EDT FRI MAY 9 2014
LOOKING AT VFR CONDITIONS THROUGH THE ENTIRE FORECAST PERIOD. MAIN
CHALLENGE TO THE AVIATION FORECAST WILL BE THE POTENTIAL FOR
THUNDERSTORMS LATER TODAY. THINGS DO NOT LOOK REAL IMPRESSIVE BASED
ON LATEST FORECAST SOUNDINGS. BELIEVE MODELS...NAM/GFS ARE OVERDOING
SFC MOISTURE AGAIN AND CONSEQUENTLY SFC BASED INSTABILITY. SOUNDINGS
ALSO HAVE THE FAMILIAR INVERTED V PROFILE TYPICALLY SEEN IN THE
WESTERN CONUS. THOUGHTS ARE THAT WE MAY CUT BACK ON PROBABILITY OF
THUNDER...FROM LIKELY TO CHANCE. HOWEVER...WITH DIRER LOWER LEVELS
THIS ALSO MEANS THAT ANY SHOWERS THAT DEVELOP WILL TEND TO BE HIGH
BASED AND PRODUCE GUSTY WINDS DUE TO THE ADDITIVE MOMENTUM OF
EVAPORATIVE COOLING OF RAINFALL. LIGHT AND VARIABLE WILL INCREASE
FROM THE SOUTH...SOUTHWEST AT 10 TO 15 KTS BY MIDDAY FRIDAY. A FEW
GUSTS TO 20 KTS WILL BE POSSIBLE LATE IN THE DAY FRIDAY. AGAIN...
WINDS COULD BE QUITE VARIABLE AND GUSTY AROUND ANY SHOWERS AND
THUNDERSTORMS THAT MAY DEVELOP.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...RAY
SHORT TERM...RAY
LONG TERM...KAS
AVIATION...RAY
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1035 AM CDT FRI MAY 9 2014
.UPDATE...
ISSUED AT CDT FRI MAY 9 2014
THE FOCUS FOR THIS UPDATE WAS THE DENSE FOG OVER WESTERN LAKE
SUPERIOR AND AREAS ALONG THE NORTH AND SOUTH SHORE...AS WELL AS
THE RAIN SHOWERS FOR TODAY AND THIS EVENING.
THE MODELS ARE SUGGESTING THE FOG WILL LINGER ALONG THE NORTH
SHORE LONGEST...PROBABLY TILL MID AFTERNOON...SO I EXTENDED THE
DENSE FOG ADVISORY FOR THE NORTH SHORE UNTIL 3 PM. THE HRRR SEEMED
TO BE DOING FAIRLY WELL WITH THE CURRENT COVERAGE OF DENSE
FOG...SO I LEANED ON THE HRRR FOR THE AFTERNOON FORECAST. THE FOG
NEAR THE TWIN PORTS SHOULD BEGIN TO LIFT VERY LATE THIS
MORNING...SO I ONLY EXTENDED THAT PART OF THE ADVISORY TILL NOON.
THE NORTHWEST WINDS DEVELOPING BEHIND THE PASSING LOW PRESSURE
SYSTEM WILL ALSO BE HELPING TO DISSIPATE THE FOG.
WE MAY HAVE HAD PCPN ENDING TOO QUICKLY...AND DID NOT HAVE HIGH
ENOUGH PCPN CHANCES ACROSS THE NORTHERN FORECAST AREA. THE MODELS
ARE IN GOOD AGREEMENT WITH THE PCPN LINGERING LONGER THAN THE
PREVIOUS FORECAST...SO I DELAYED ITS DISSIPATION AND/OR EXIT FROM
THE FORECAST AREA THROUGH THIS EVENING.
UPDATE ISSUED AT 620 AM CDT FRI MAY 9 2014
UPDATED FOR AVIATION DISCUSSION.
&&
.SYNOPSIS...
ISSUED AT 354 AM CDT FRI MAY 9 2014
SURFACE LOW CURRENTLY JUST NORTHEAST OF KSTL IS GRADUALLY MOVING
NORTHEAST...WITH SOME FAIRLY STRONG PRESSURE FALLS AND AN INVERTED
TROUGH OVER THE ARROWHEAD THIS MORNING. EXTENDING FROM CENTRAL
WISCONSIN UP OVER WESTERN UPPER MICHIGAN AND LAKE SUPERIOR IS A BAND
OF SHOWERS AND THUNDERSTORMS THAT MOVED OVER THE FORECAST AREA
OVERNIGHT. OVER WESTERN MINNESOTA...EASTERN NORTH AND SOUTH DAKOTA
IS AN AREA OF RAIN SHOWERS IN THE WRAP AROUND PORTION OF THE
STORM...ACCOMPANIED BY A NICE PV ANOMALY INDICATIVE OF A TROWAL.
THE SURFACE WARM FRONT EXTENDS EAST FROM THE SURFACE LOW ALONG THE
DEWPOINT DISCONTINUITY OVER NORTHERN WISCONSIN AND INTO UPPER
MICHIGAN. THE COLD FRONT EXTENDS SOUTH FROM THE LOW...AND IS
PLOWING EAST ACROSS IOWA AND MISSOURI. IN THE CONVERGENT AREA AHEAD
OF THE SURFACE LOW WHERE WINDS ARE LIGHT AND DEWPOINT DEPRESSIONS
ARE LOW...AREAS OF FOG HAVE DEVELOPED. IT SEEMS MOST WIDESPREAD
WHERE SOME OF THE COOLER MARINE LAYER HAS SLOPPED ASHORE IN THE
LIGHT NORTHEAST FLOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT FRI MAY 9 2014
THE SURFACE LOW WILL CONTINUE TO MOVE NORTHEAST TODAY...EXITING
TO CENTRAL ONTARIO BY 18Z TODAY. THE AREAS OF DENSE FOG MENTIONED
ABOVE HAVE BEEN PERSISTENT MOST OF THE NIGHT AHEAD OF THE
LOW...AND HAVE DECIDED TO ISSUE A DENSE FOG FOR THE NORTH SHORE
AND AREAS AROUND THE HEAD OF THE LAKE UNTIL MID MORNING. AS THE
SURFACE LOW MOVES ACROSS THE AREA THE WIND DIRECTION WILL TURN
AROUND TO THE NORTHWEST...SOME DRIER AIR WILL BEGIN TO WORK INTO
THE AREA EVEN IF TEMPERATURES DONT CHANGE MUCH...SO EXPECT THE FOG
TO DISSIPATE BY MID MORNING.
THE SHOWERS THIS MORNING OVER THE FAR NORTHEASTERN CWA SHOULD MOVE OFF
TO THE EAST...LEAVING THAT PART OF THE FORECAST AREA MOSTLY DRY.
THE AREA OF SHOWERS ASSOCIATED WITH THE TROWAL ARE GOING TO SWEEP
ACROSS THE FORECAST AREA TODAY AND EARLY THIS EVENING...MAINLY
OVER NORTHERN MINNESOTA. AM FAIRLY CONFIDENT IN THIS AREA OF
PRECIPITATION...SO HAVE RAISED POPS SOMEWHAT AND REFINED TIMING
SOMEWHAT. UNDER THIS AREA OF SHOWERS TEMPERATURES ARE GOING TO
ONLY GET INTO THE UPPER 40S TO AROUND 50...WITH HIGHS IN THE MID
TO UPPER 50S MOST OTHER LOCATIONS. TEMPERATURES EARLY THIS MORNING
ARE IN THE UPPER 50S TO LOWER 60S OVER PORTIONS OF NORTHWEST
WISCONSIN WHERE THEY ARE IN THE WARM SECTOR. EXPECT THAT THEY ARE
AT OR NEAR THEIR HIGHS FOR TODAY...AND WILL ONLY REMAIN STEADY OR
SLOWLY FALL THE REST OF THE DAY. TONIGHT THE SHOWERS WILL STILL BE
AFFECTING THE ARROWHEAD REGION IN THE EVENING...BUT A THERE WILL
BE A GRADUAL CLEARING TREND SETTING UP FROM SOUTHWEST TO NORTHEAST
AS THE STORM GRADUALLY MOVES OFF TO THE NORTHEAST TONIGHT. EXPECT
TEMPERATURES TO FALL OFF INTO THE MID 30S MOST LOCATIONS...AS I
EXPECT CLEARING TO OCCUR FOR NEARLY THE WHOLE CWA BY EARLY
MORNING. WINDS WILL DROP OFF ENOUGH FOR RADIATIONAL COOLING TO BE
FAIRLY SIGNIFICANT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 354 AM CDT FRI MAY 9 2014
A NARROW RIDGE OF HIGH PRESSURE ALOFT AND AT THE SURFACE WILL BUILD
IN SAT MORNING WITH DRY CONDITIONS AND MOSTLY SUNNY SKIES THROUGH
MOST OF THE DAY. A WEAK UPPER S/W AND ASSOCIATED SFC TROUGH WILL
LIFT E/NEWD FROM THE DAKOTAS INTO MN AND WRN LAKE SUPERIOR LATER IN
THE DAY SATURDAY AND ESPECIALLY SAT NIGHT. THIS SYSTEM WILL PRODUCE
ANOTHER ROUND OF WIDESPREAD RAIN SHOWERS AND A FEW WEAK
THUNDERSTORMS. THE SFC BOUNDARY WILL STALL OUT AS IT LIFTS NWD INTO
NRN MN AND AWAIT THE NEXT SURGE OF WARM MOIST AIR LATE IN THE
WEEKEND...ALONG WITH THE NEXT LOW PRESSURE SYSTEM EXPECTED TO TRACK
SW TO NE OVER THE UPPER MIDWEST MON INTO TUE MORNING. THIS SYSTEM
WILL ONCE AGAIN BE LOADED WITH MOISTURE AND ALSO DRAW UP A SLIGHTLY
UNSTABLE AIR MASS TO PRODUCE ISOLATED THUNDERSTORMS AND THE
POTENTIAL FOR LOCALLY HEAVY RAINFALL. AS THE SFC LOW APPROACHES FROM
THE SW...PRESSURE FALLS WILL INDUCE A STRONG NE FLOW OFF LAKE
SUPERIOR AND COMBINE WITH FAIRLY STRONG WAA IN THE MID/LOW LVLS TO
PRODUCE ANOTHER PERIOD OF COOL/CLOUDY/FOGGY CONDITIONS AROUND THE
PERIPHERY OF THE LAKE. THE PRESENCE OF THIS COOL/STABLE NEAR-SFC
LAYER WILL KEEP ANY STORMS ELEVATED THAT TRACK TO THE
NORTH...KEEPING THE THREAT OF STRONG/SEVERE WX ON THE LOW SIDE. AN
UNSEASONABLY COLD AIR MASS WILL ADVECT IN ON THE BACK SIDE OF THIS
SYSTEM AS IT DEPARTS TO THE EAST LATE TUE AND WED. THE AIR PUSHING
IN FROM THE NW COULD BE COLD ENOUGH TO ALLOW FOR A FEW LIGHT SNOW
SHOWERS TO MIX IN LATE TUE NIGHT...AND AGAIN LATE WED NIGHT. 850MB
TEMPS WILL BE ROUGHLY -5 TO -10 DEG C. YES IT IS ALMOST THE MIDDLE
OF MAY. WILL SEE SLIGHT IMPROVEMENT INTO THURSDAY AS HIGH PRESSURE
GRADUALLY BUILDS IN ACROSS THE MIDWEST. HOWEVER IT WILL NOT BE UNTIL
THE WEEKEND UNTIL TEMPS REACH BACK TO NEAR NORMAL.
TEMPERATURES THIS WEEKEND WILL BE AT OR SLIGHTLY ABOVE NORMAL WITH
LIGHT AND VARIABLE WINDS. SATURDAY WILL LIKELY BE THE MOST PLEASANT
DAY WITH DRY CONDITIONS EXPECTED. THE TEMP TREND WILL BEGIN A
DOWNWARD SLIDE MON THROUGH WED WITH HIGHS IN THE 40S AND 50S AND
OVERNIGHT LOWS IN THE 30S. A GRADUAL WARMING TREND WILL NOT BE FELT
UNTIL THE LATTER HALF OF THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 620 AM CDT FRI MAY 9 2014
LIFR CIGS AND VSBYS WILL PERSIST THIS MORNING WITH GRADUAL
IMPROVEMENT THROUGH THE AFTERNOON AS THE LOW PRESSURE SYSTEM LIFTS
NEWD ACROSS THE NORTHLAND. WILL SEE A BAND OF RAIN SHOWERS ON THE
BACK SIDE OF THIS SYSTEM ROTATE EWD THROUGH THE REGION THIS
MORNING AND INTO THE AFTERNOON...TAPERING OFF WEST TO EAST. CIGS
WILL LIFT TO MVFR AND EVENTUALLY VFR THIS AFTERNOON...WITH
CLEARING SKIES W-E EXPECTED THIS EVENING AND TONIGHT. WINDS
ROTATING AROUND THE SFC LOW TODAY WILL BE GUSTY...UP TO 15 TO 25
KNOTS. WINDS WILL DIMINISH TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 51 37 63 48 / 60 40 10 60
INL 50 34 67 44 / 80 40 0 50
BRD 55 36 64 46 / 70 10 40 50
HYR 57 38 67 47 / 70 30 10 50
ASX 56 38 64 45 / 40 40 0 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR MNZ037.
DENSE FOG ADVISORY UNTIL 3 PM CDT THIS AFTERNOON FOR MNZ020-021.
WI...DENSE FOG ADVISORY UNTIL NOON CDT TODAY FOR WIZ001.
LS...SMALL CRAFT ADVISORY UNTIL 4 AM CDT SATURDAY FOR LSZ143>147.
DENSE FOG ADVISORY UNTIL 11 AM CDT THIS MORNING FOR LSZ144-145.
DENSE FOG ADVISORY UNTIL 1 PM CDT THIS AFTERNOON FOR LSZ142-143.
DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ140-141.
&&
$$
UPDATE...GROCHOCINSKI
SYNOPSIS...LE
SHORT TERM...LE
LONG TERM...BJT
AVIATION...BJT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
600 AM CDT FRI MAY 9 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT FRI MAY 9 2014
RAP ANALYZED SURFACE LOW JUST SOUTH OF DULUTH EARLY THIS MORNING.
AREAS WEST OF THE METRO HAVE SEEN THE WINDS TURN WESTERLY AND PICK
UP IN INTENSITY. COLD AIR ADVECTION IS ONGOING IN THESE AREAS...AND
WILL CONTINUE TO SPREAD ACROSS THE REMAINDER OF THE FORECAST AREA
TODAY. THE SURFACE LOW WILL SLOWLY CONTINUE NORTHEASTWARD...AS THE
WESTERLY WINDS TAKE MUCH OF THE DAY TO SPREAD ACROSS WEST CENTRAL
WISCONSIN. ABUNDANT LOW LEVEL MOISTURE WILL ALLOW FOR LOW LCL
HEIGHTS WHICH IS CURRENTLY NOTICEABLE IN THE OBSERVATIONS BEHIND THE
COLD FRONT WHERE CEILINGS UNDER 1K FEET ARE PRESENT. RAP AND NAM
MODEL SOUNDINGS INDICATE THIS MOISTURE STICKING AROUND FOR MUCH OF
THE DAY...SO TRENDED TOWARD A MORE PESSIMISTIC SKY COVER FORECAST
AND HENCE LOWERED MAX TEMPERATURES TODAY BY A FEW DEGREES ACROSS THE
FA. MAX TEMPS WILL BE ABOUT 10 DEGREES BELOW SEASONAL NORMALS FOR
THIS TIME OF YEAR. IN ADDITION...WRAP AROUND LIGHT RAIN SHOWERS ARE
EXPECTED TO MOVE ACROSS THE NORTHERN PORTION OF THE CWA AS THEY
CYCLONIC CIRCULATION ALOFT REMAINS BETTER TOWARD THE NORTH /AS WELL
AS AT LEAST SOME FGEN AND FN VECTOR CONVERGENCE/. SKIES WILL BEGIN
CLEARING LATE THIS AFTERNOON AND MOSTLY CLEAR SKIES ARE EXPECTED
OVERNIGHT...EXCEPT CLOUDS WILL QUICKLY BEGIN FILLING IN FROM THE
SOUTHWEST EARLY SATURDAY MORNING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 340 AM CDT FRI MAY 9 2014
AN UNSETTLED PERIOD REMAINS FORECAST FOR MUCH OF THE LONGER TERM
AS NORTHERN AND SOUTHERN STREAM ENERGY EVENTUALLY PHASE OVER THE
CENTER OF THE COUNTRY AROUND THE MIDDLE OF NEXT WEEK. THIS PROCESS
OCCURS THE FASTEST WITH THE GFS WHILE DP/DT SHOWS THAT THE SLOWER
ECMWF IS BECOMING EVEN SLOWER WITH TIME.
ON SATURDAY...A WAVE MOVING IN FROM THE CENTRAL PLAINS WILL BRING
THICKENING CLOUDINESS AND SHOWERS BACK ACROSS THE FA FROM SW TO NE
DURING THE DAY. A BRIEF BREAK IN THE PRECIPITATION IS EXPECTED
SATURDAY NIGHT BEFORE A MORE POTENT WAVE BEGINS TO TAKE SHAPE OVER
THE CENTRAL PLAINS ON SUNDAY. THIS WAVE IS BEING DRIVEN BY THE
SOUTHERN STREAM ENERGY. USING THE SLOWER ECWMF...THE LOW IN THE
PLAINS TAKES UNTIL MONDAY EVENING TO ARRIVE IN SE MN. THIS PLACES
MUCH OF THE FA IN LOW LEVEL THETA-E ADVECTION FROM SUNDAY THROUGH
MONDAY...WITH SOUTHERN MN BEARING THE BRUNT OF IT. HENCE...LIKELY
POPS STREAM BACK IN ON SUNDAY FROM THE SOUTHWEST AND PERSIST THROUGH
MONDAY. WIDESPREAD HALF INCH TO ONE INCH RAINFALL IS LIKELY DURING
THIS PERIOD WITH SOME TWO INCH AMOUNTS OVER SOUTHERN MN. THERE WILL
CERTAINLY BE THE THREAT FOR SOME THUNDERSTORMS...ESPECIALLY ON
MONDAY FROM THE TWIN CITIES ON EAST AND SOUTH. STRICTLY USING THE
ECMWF TIMING WOULD INDICATE A WINDOW OF OPPORTUNITY FOR STRONG TO
SEVERE STORMS MONDAY AFTERNOON/EVENING TO THE SOUTH AND EAST OF
THE TWIN CITIES.
THE SHOWERS WILL BEGIN TO TAPER OFF MONDAY NIGHT AS THE LOW
PRESSURE SYSTEM MOVES NORTHEAST OF THE FA. INSTABILITY SHOWERS ARE
POSSIBLE MAINLY FROM CENTRAL MINNESOTA ON NORTHWARD ON TUESDAY.
SCATTERED SHOWERS ARE BACK FOR MUCH OF THE FA WEDNESDAY AND
THURSDAY AS THE UPPER TROUGH COMES TOGETHER FROM THE UPPER
MISSISSIPPI VALLEY TO THE GULF COAST. HIGH TEMPERATURES WILL BE
CLOSE TO NORMAL THIS WEEKEND...BUT THEN RETREAT TO SOME 10 TO 15
DEGREES BELOW NORMAL FOR THE MIDDLE TO END OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 547 AM CDT FRI MAY 9 2014
LOW PRESSURE CENTER LIFTING NORTHEAST TOWARD LAKE
SUPERIOR...LEAVING A SOLID LOW STRATUS DECK ACROSS MINNESOTA AND
WESTERN WISCONSIN. MODELS HAVE BECOME MORE PESSIMISTIC OVER THE
LAST 2 RUNS IN HANDLING THIS MOISTURE...AND CLOSELY FOLLOWED
UPDATED GUIDANCE TO HOLD CIGS IN THE IFR/MVFR RANGE FOR MOST OF
TODAY...WITH PERIODS OF LIFR POSSIBLE. THERE HAS BEEN SOME PATCHY
FOG THROUGH THE OVERNIGHT HOURS...WHICH HAS BEEN HARD TO PIN DOWN
BECAUSE IT IS WIDELY SCATTERED. THE CEILINGS HAVE BEEN BOUNCING A
BIT...ESPECIALLY AT EASTERN SITES. BOTH RAP AND NAM STILL INDICATE
LOW CIGS WITH GRADUAL LIFTING. SCATTERED SHOWERS WILL ROTATE
THROUGH THE NORTHERN HALF OF THE CWA. WINDS WILL REMAIN WESTERLY
AND CONTINUE GUSTING TODAY. SKIES WILL CLEAR OUT TONIGHT...AND
WINDS WILL BECOME LIGHT AND VARIABLE FOR A TIME.
KMSP...IFR CIGS WITH POSSIBLY LIFR AT TIMES WILL CONTINUE THIS
MORNING. IT LOOKS LIKE THE SCATTERED SHOWERS WILL SIDE SWIPE THE
TERMINAL...SO MAY STAY COMPLETELY DRY...BUT DID FEEL INCLINED TO
INCLUDE A MENTION OF LIGHT PRECIPITATION TODAY.
/OUTLOOK FOR KMSP/
SAT...VFR. CHC -TSRA. WINDS SSE 10KTS.
SUN...MVFR POSSIBLE. LIKELY -SHRA. WINDS SW TO NW 10-15 KTS.
MON...MVFR POSSIBLE. LIKELY -SHRA. WINDS NW 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...SPD
LONG TERM...RAH
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS TULSA OK
1026 AM CDT FRI MAY 9 2014
...UPDATE...
.DISCUSSION...
A COLD FRONT WAS POSITIONED NEAR A LINE FROM GROVE TO JUST SOUTH
OF TULSA TO NEAR OKEMAH LATE THIS MORNING. BEHIND THE
FRONT...NORTHERLY WINDS AND PARTLY CLOUDY SKIES WERE BEING
OBSERVED. AHEAD OF THE FRONT...LOW CEILINGS WERE COMMON ACROSS THE
MAJORITY OF EASTERN OKLAHOMA AND NORTHWEST ARKANSAS. ALSO SOME
PATCHY AREAS OF LIGHT DRIZZLE HAVE BEEN REPORTED WITHIN THE LOW
CLOUDS THIS MORNING. A CHANCE OF A SHOWER AND OR A THUNDERSTORM
WILL ALSO BE POSSIBLE...MAINLY ACROSS FAR NORTHWEST ARKANSAS
THROUGH THE MORNING HOURS AHEAD OF THE FRONT.
THE COLD FRONT WILL CONTINUE ITS EASTWARD MOVEMENT INTO THE
AFTERNOON HOURS AND IS EXPECTED TO STALL ACROSS SOUTHEAST OKLAHOMA
INTO NORTHWEST ARKANSAS FOR THE LATE AFTERNOON/EVENING HOURS.
SKIES SHOULD CONTINUE TO SCATTER OUT BEHIND THE FRONT AND BECOME
PARTLY CLOUDY AHEAD OF THE FRONT...ALLOWING TEMPS TO GET INTO THE
70S TO LOW 80 FROM NORTH TO SOUTH. DIURNAL HEATING AND INSTABILITY
AHEAD OF THE FRONT WILL ALLOW FOR AT LEAST A SLIGHT CHANCE OF
THUNDERSTORMS THROUGH THE EVENING HOURS. THOUGH...LATEST HRRR AND
LOCAL IN-HOUSE MODEL RUNS ARE DEVELOPING ACTIVITY JUST TO THE EAST
OF THE CWA THIS AFTERNOON. ANY THUNDERSTORMS THAT DEVELOP WILL
HAVE THE POTENTIAL TO BECOME STRONG TO SEVERE...WITH LARGE
HAIL/STRONG WINDS BEING THE MAIN HAZARDS. FOR MORNING
UPDATE...WILL CONTINUE THE SLIGHT CHANCE OF THUNDERSTORMS ACROSS
THE EAST THIS AFTERNOON AND WILL ADD PATCHY DRIZZLE THROUGH THE
LATE MORNING HOURS AHEAD OF THE FRONT. HAVE ALSO TWEAKED SKY GRIDS
AND WILL MONITOR TEMPS THROUGH THE AFTERNOON FOR ANY ADDITIONAL
UPDATES.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 77 62 90 72 / 10 10 20 20
FSM 81 63 87 69 / 20 10 30 20
MLC 81 64 86 71 / 10 10 20 10
BVO 76 58 90 68 / 10 10 30 20
FYV 76 58 83 67 / 20 10 30 20
BYV 76 58 83 67 / 30 10 30 30
MKO 78 61 88 70 / 10 10 20 20
MIO 75 58 87 69 / 30 10 30 30
F10 78 63 88 70 / 10 10 20 20
HHW 84 65 86 70 / 10 20 20 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...20
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1028 AM CDT FRI MAY 9 2014
.DISCUSSION...
RADAR COMPOSITES THIS MORNING SHOWING SHOWERS AND THUNDERSTORMS
PRETTY MUCH SURROUNDING THE FORECAST AREA...WITH CLUSTERS TO THE
NORTHEAST AND SOUTHWEST...AND SOME STRONG TO SEVERE CELLS OFF TO
THE WEST OF SAN ANTONIO. MORNING SOUNDINGS AND MODEL FORECAST
SOUNDING SUGGEST CURRENTLY WEAKLY CAPPED ATMOSPHERE SHOULD BECOME
UNSTABLE THIS AFTERNOON...ASSUMING CLOUD COVER ERODES AS EXPECTED AND
TEMPS RISE INTO THE MID 80S. SHOULD THAT MATERIALIZE...LOOKING AT
CAPE VALUES ABOVE 3000 J PER KG...ESPECIALLY NW ZONES. SHEAR
PROFILES SHOW ZERO TO 6 KM VALUES IN THE 20 TO 30 KNOT RANGE. WITH
MODERATE INSTABILITY AND SHEAR...AND DRIER AIR ALOFT...EXPECT
MULTICELLS LIKELY THE DOMINANT CONVECTIVE MODE...WITH SOME
POTENTIAL FOR ISOLATED DOWNBURST WINDS AND HAIL BEING THE MAIN
THREATS. LOW LEVEL SHEAR NOT VERY STRONG...SO TORNADOES NOT
LIKELY.
&&
.MARINE...
SE WINDS OF 10-15 KNOTS TODAY. TROPICAL TAP OF MOISTURE FROM THE
PACIFIC IS DRAPED OVER MEXICO AND THE COASTAL WATERS. THE NORTHERN
PERIPHERY OF THE MOISTURE MAY EXTEND OVER THE BAYS. THIS ABUNDANT
MOISTURE AND NOISY SW-WSW FLOW ALOFT SHOULD KEEP THE MARINE
ENVIRONMENT ACTIVE WITH SHOWERS AND THUNDERSTORMS TODAY...ESPECIALLY
IF ANY BREAKS FORM.
45
&&
.AVIATION...
CIGS GRADUALLY RISING WITH MOSTLY MVFR (1500-2000FT) AT 15Z THOUGH
CLL/UTS WERE VFR CIGS BUT STILL HAVE SOME HAZE. EXPECT THAT ACROSS
THE AREA WE WILL CONTINUE TO SEE CIGS RISE AND BREAKS DEVELOP SO BKN
TO SCT VFR CIGS CAN BE EXPECTED FOR HOU/IAH NORTHWARD BY 19Z...IF
NOT SOONER. GIVEN THE POOR MODEL CONSENSUS AND POOR INITIALIZATION
OF CONVECTION TO THE WEST ANY TIMING FOR ONSET OF SHRA/TSRA IN THE
SETX TERMINALS IS LOW CONFIDENCE. THOUGH THE ENVIRONMENT IS RIPE
THIS AFTERNOON PERHAPS PEAK HEATING AND THE ARRIVAL OF S/W NEAR DRT
MAY BE ENOUGH TO OVERCOME THE SMALL CAP THIS AFTERNOON. ANY THAT DO
FORM SHOULD BE CAPABLE OF STRONG GUSTY WINDS AND POSSIBLY AND CAN`T
RULE OUT SOME SMALL HAIL THOUGH THAT MAY BE CONFINED TO AREAS WEST
OF A BYY-CLL LINE.
45
.PREV DISCUSSION... /ISSUED 638 AM CDT FRI MAY 9 2014/
DISCUSSION...
SEE THE 12Z AVIATION DISCUSSION BELOW.
40
AVIATION...
IFR TO MVFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE MORNING.
THE MODELS ARE INDICATING POSSIBLE VFR DURING THE MID OR LATE
AFTERNOON PERIOD. BEST CHANCES FOR SHOWERS OR THUNDERSTORMS WILL
BE AT KCLL AND KUTS. HOWEVER...GIVEN THE MOISTURE CHANNEL OVER THE
GULF...THERE IS A SLIGHT CHANCE OF SHOWERS FROM KHOU TO THE COAST
THROUGH 15Z. MAY AMEND IF MORE SHOWERS THAN EXPECTED DEVELOP.
THIS EVENING...MODEL SOUNDINGS INDICATE MVFR TO IFR CONDTIONS WILL
DEVELOP.
40
PREV DISCUSSION... /ISSUED 333 AM CDT FRI MAY 9 2014/
DISCUSSION...
AT 06Z...THERE WAS A WEAK AREA OF LOW PRESSURE OVER CENTRAL
OKLAHOMA AND ANOTHER WEAK AREA OF LOW PRESSURE NORTH OF DEL RIO.
SFC DEW PTS REMAIN IN THE LOWER 70S. RADAR IS A LITTLE MORE ACTIVE
THAN THE PAST FEW NIGHTS WITH A LINE OF STORMS DEVELOPING ACROSS
EXTREME SE TX FROM KBPT TO KGLS AND A SMALL CLUSTER NEAR KGRK.
WATER VAPOR IMAGERY SHOWS A WELL DEFINED S/WV IN EASTERN NEW
MEXICO AND THIS FEATURE WAS MOVING EAST AND WILL SERVE AS A
CATALYST FOR SHRA/TSRA OVER PARTS OF CENTRAL AND EASTERN TEXAS
TODAY. THE DISTURBANCE WILL APPROACH SE TX THIS AFTN AND FEEL IT
WILL TRIGGER TSRA OVER MAINLY THE WESTERN HALF OF THE CWA. NAM 12
SOUNDING FOR KCLL ARE VERY UNSTABLE WITH PWATS INCREASING FROM
1.38 THIS MORNING TO 1.79 THIS AFTN. CAPE VALUES EXCEED 3000 J/KG
AND LI`S DROP TO -9. SPC HAS OUTLOOKED THE WESTERN HALF OF SE TX
IN SLIGHT RISK AND SEE NO REASON TO DISAGREE. THE NAM...GFS AND
ECMWF ALL SHOW A SPEED MAX APPROACHING THIS AFTERNOON SO IT LOOKS
LIKE ALL THE INGREDIENTS ARE IN PLACE FOR SOME SEVERE WEATHER OVER
THE WESTERN ZONES. TOWARD THE HOUSTON AREA AND THE COAST...CAPPING
LOOKS TO REMAIN AN ISSUE AND PWATS ACTUALLY DROP THIS AFTN. WILL
MAINTAIN LOW END CHANCE POPS BUT SOUNDINGS LOOK MUCH LESS
FAVORABLE. THINGS SHOULD SETTLE DOWN QUICKLY TONIGHT WITH THE
LOSS OF HEATING. FWIW...THE HRRR INITIALIZED BEST THIS MORNING AND
HAVE LEANED TOWARD THIS SOLUTION FOR THE SHORT TERM.
VERY WARM AND HUMID CONDITIONS ARE EXPECTED OVER THE WEEKEND.
CAN`T RULE OUT ISOLATED SHOWERS WITH HEATING EACH DAY. PWATS
REMAIN AROUND 1.5-1.6 INCHES SO WILL MENTION A SLIGHT CHANCE OF
SHRAS EACH DAY.
THINGS BECOME A LITTLE MORE MUDDLED MON-WED. A DEEP UPPER LEVEL
TROUGH AND SURFACE COLD FRONT WILL APPROACH THE STATE ON MONDAY.
MODELS ARE IN GOOD AGREEMENT THROUGH MONDAY 12Z BUT DIVERGE
SIGNIFICANTLY THEREAFTER. GFS IS ABOUT 24-30 HOURS FASTER THAN THE
ECMWF. THE CANADIAN SUPPORTS THE SLOWER ECMWF. NOT REALLY SURE
HOW THINGS WILL EVENTUALLY TRANSPIRE THIS FAR OUT SO HAVE STARTED
POPS ON MONDAY AND WILL CARRY POPS THROUGH WEDNESDAY. AT THE
CURRENT TIME...FEEL TUESDAY WILL BE THE BEST DAY FOR RAIN CHANCES
BUT THAT IS SUBJECT TO CHANGE. HAVE RAISED RAIN CHANCES ON TUESDAY
TO 50 PERCENT. CONSIDERABLY COOLER AND DRIER CONDITIONS WILL
DEVELOP IN THE WAKE OF THE FRONT FOR THE SECOND HALF OF NEXT WEEK
WITH MIN TEMPS POSSIBLY FALLING BACK INTO THE 50S. 43
MARINE...
ONSHORE WINDS ARE EXPECTED THROUGH THE WEEKEND. WIND SPEEDS WILL BE
HIGH ENOUGH THIS MORNING FOR CAUTION CONDITIONS. MODERATE TO STRONG
ONSHORE WINDS ARE THEN EXPECTED TO DEVELOP SUNDAY NIGHT AS LOW
PRESSURE DEVELOPS OVER THE PLAINS. THE MODELS THEN DIFFERED ON THE
PASSAGE OF A COLD FRONT THROUGH SE TX AND OFF THE COAST. LIKED THE
SLOWER ECMWF.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 86 69 88 71 88 / 30 30 10 10 10
HOUSTON (IAH) 86 71 87 73 87 / 40 20 20 10 20
GALVESTON (GLS) 81 73 82 73 82 / 40 20 20 10 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...46
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
638 AM CDT FRI MAY 9 2014
.DISCUSSION...
SEE THE 12Z AVIATION DISCUSSION BELOW.
40
&&
.AVIATION...
IFR TO MVFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE MORNING.
THE MODELS ARE INDICATING POSSIBLE VFR DURING THE MID OR LATE
AFTERNOON PERIOD. BEST CHANCES FOR SHOWERS OR THUNDERSTORMS WILL
BE AT KCLL AND KUTS. HOWEVER...GIVEN THE MOISTURE CHANNEL OVER THE
GULF...THERE IS A SLIGHT CHANCE OF SHOWERS FROM KHOU TO THE COAST
THROUGH 15Z. MAY AMEND IF MORE SHOWERS THAN EXPECTED DEVELOP.
THIS EVENING...MODEL SOUNDINGS INDICATE MVFR TO IFR CONDTIONS WILL
DEVELOP.
40
&&
.PREV DISCUSSION... /ISSUED 333 AM CDT FRI MAY 9 2014/
DISCUSSION...
AT 06Z...THERE WAS A WEAK AREA OF LOW PRESSURE OVER CENTRAL
OKLAHOMA AND ANOTHER WEAK AREA OF LOW PRESSURE NORTH OF DEL RIO.
SFC DEW PTS REMAIN IN THE LOWER 70S. RADAR IS A LITTLE MORE ACTIVE
THAN THE PAST FEW NIGHTS WITH A LINE OF STORMS DEVELOPING ACROSS
EXTREME SE TX FROM KBPT TO KGLS AND A SMALL CLUSTER NEAR KGRK.
WATER VAPOR IMAGERY SHOWS A WELL DEFINED S/WV IN EASTERN NEW
MEXICO AND THIS FEATURE WAS MOVING EAST AND WILL SERVE AS A
CATALYST FOR SHRA/TSRA OVER PARTS OF CENTRAL AND EASTERN TEXAS
TODAY. THE DISTURBANCE WILL APPROACH SE TX THIS AFTN AND FEEL IT
WILL TRIGGER TSRA OVER MAINLY THE WESTERN HALF OF THE CWA. NAM 12
SOUNDING FOR KCLL ARE VERY UNSTABLE WITH PWATS INCREASING FROM
1.38 THIS MORNING TO 1.79 THIS AFTN. CAPE VALUES EXCEED 3000 J/KG
AND LI`S DROP TO -9. SPC HAS OUTLOOKED THE WESTERN HALF OF SE TX
IN SLIGHT RISK AND SEE NO REASON TO DISAGREE. THE NAM...GFS AND
ECMWF ALL SHOW A SPEED MAX APPROACHING THIS AFTERNOON SO IT LOOKS
LIKE ALL THE INGREDIENTS ARE IN PLACE FOR SOME SEVERE WEATHER OVER
THE WESTERN ZONES. TOWARD THE HOUSTON AREA AND THE COAST...CAPPING
LOOKS TO REMAIN AN ISSUE AND PWATS ACTUALLY DROP THIS AFTN. WILL
MAINTAIN LOW END CHANCE POPS BUT SOUNDINGS LOOK MUCH LESS
FAVORABLE. THINGS SHOULD SETTLE DOWN QUICKLY TONIGHT WITH THE
LOSS OF HEATING. FWIW...THE HRRR INITIALIZED BEST THIS MORNING AND
HAVE LEANED TOWARD THIS SOLUTION FOR THE SHORT TERM.
VERY WARM AND HUMID CONDITIONS ARE EXPECTED OVER THE WEEKEND.
CAN`T RULE OUT ISOLATED SHOWERS WITH HEATING EACH DAY. PWATS
REMAIN AROUND 1.5-1.6 INCHES SO WILL MENTION A SLIGHT CHANCE OF
SHRAS EACH DAY.
THINGS BECOME A LITTLE MORE MUDDLED MON-WED. A DEEP UPPER LEVEL
TROUGH AND SURFACE COLD FRONT WILL APPROACH THE STATE ON MONDAY.
MODELS ARE IN GOOD AGREEMENT THROUGH MONDAY 12Z BUT DIVERGE
SIGNIFICANTLY THEREAFTER. GFS IS ABOUT 24-30 HOURS FASTER THAN THE
ECMWF. THE CANADIAN SUPPORTS THE SLOWER ECMWF. NOT REALLY SURE
HOW THINGS WILL EVENTUALLY TRANSPIRE THIS FAR OUT SO HAVE STARTED
POPS ON MONDAY AND WILL CARRY POPS THROUGH WEDNESDAY. AT THE
CURRENT TIME...FEEL TUESDAY WILL BE THE BEST DAY FOR RAIN CHANCES
BUT THAT IS SUBJECT TO CHANGE. HAVE RAISED RAIN CHANCES ON TUESDAY
TO 50 PERCENT. CONSIDERABLY COOLER AND DRIER CONDITIONS WILL
DEVELOP IN THE WAKE OF THE FRONT FOR THE SECOND HALF OF NEXT WEEK
WITH MIN TEMPS POSSIBLY FALLING BACK INTO THE 50S. 43
MARINE...
ONSHORE WINDS ARE EXPECTED THROUGH THE WEEKEND. WIND SPEEDS WILL BE
HIGH ENOUGH THIS MORNING FOR CAUTION CONDITIONS. MODERATE TO STRONG
ONSHORE WINDS ARE THEN EXPECTED TO DEVELOP SUNDAY NIGHT AS LOW
PRESSURE DEVELOPS OVER THE PLAINS. THE MODELS THEN DIFFERED ON THE
PASSAGE OF A COLD FRONT THROUGH SE TX AND OFF THE COAST. LIKED THE
SLOWER ECMWF.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 86 69 88 71 88 / 50 30 10 10 10
HOUSTON (IAH) 86 71 87 73 87 / 30 20 20 10 20
GALVESTON (GLS) 81 73 82 73 82 / 30 20 20 10 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS TAUNTON MA
509 PM EDT FRI MAY 9 2014
.SYNOPSIS...
A WARM FRONT WILL APPROACH TONIGHT BRINGING A PERIOD OF SCATTERED
SHOWERS BEFORE IT LIFTS INTO NORTHERN NEW ENGLAND SATURDAY. BEHIND
THE FRONT A WARMER AND MORE HUMID AIRMASS OVERSPREADS THE REGION
SATURDAY. A COLD FRONT WILL MOVE ACROSS THE AREA LATE SATURDAY
NIGHT INTO EARLY SUNDAY MORNING...YIELDING A ROUND OF SCATTERED
SHOWERS. HIGH PRESSURE BUILDS IN FOR MOTHERS DAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
345 PM UPDATE...
WARM FRONT ACROSS WESTERN PA AND NY WILL APPROACH THE REGION LATER
TONIGHT. BEFORE THEN COOL PREFRONTAL AIRMASS REMAINS OVER SOUTHERN
NEW ENGLAND AS ONSHORE FLOW MAINTAINS COOL MOIST SHALLOW AIRMASS.
WATER VAPOR IMAGERY ALONG WITH MODEL CROSS SECTIONS AND TIME
SECTIONS REVEAL MID LEVEL DRY AIR OVERSPREAD THE REGION AS WELL.
THIS COMBINED WITH MOIST SHALLOW ONSHORE FLOW IS RESULTING IN
AREAS OF DRIZZLE AND FOG ESPECIALLY IN THE CT RVR VLY AND THE
HIGHER TERRAIN /UPSLOPE FLOW/. THIS WILL BECOME MORE WIDESPREAD
THIS EVENING ESPECIALLY WITH SUNSET. THUS NO APPRECIABLE RAINFALL
THIS EVENING. NOT A WASHOUT JUST SPOTTY LIGHT RAIN/DRIZZLE. LAST
SEVERAL RUNS OF THE HRRR SUPPORT THIS THINKING AS WELL.
LATER TONIGHT WARM FRONT ENTERS THE REGION WITH RAIN BECOMING
MORE WIDESPREAD AS MODELS INDICATE MODEST ISENTROPIC LIFT/UPGLIDE
ACROSS THE REGION 06-12Z. MARGINAL INSTABILITY ALOFT TO SUPPORT A
VERY LOW RISK OF AN ISOLATED TSTM WITH LOCALLY BRIEF HEAVY
DOWNPOUR TOWARD SUNRISE. HOWEVER MUCH OF THE ACTIVITY SHOULD BE ON
THE LIGHT SIDE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
SATURDAY...WARM FRONT LIFTS NORTH OF THE REGION BY MID TO LATE
MORNING WITH WARM SECTOR OVERSPREADING SOUTHERN NEW ENGLAND.
DEFINITELY A BIT OF A SUMMER-ISH FEEL TO THE AIRMASS TOMORROW WITH
MAY SUNSHINE LIFTING TEMPS INTO THE 70S AND DEW PTS IN THE L60S.
AS FOR INSTABILITY DETERMINISTIC AND ENSEMBLE GUIDANCE SUGGEST
ONLY 200-500 J/KG OF MU AND MEAN CAPE TOMORROW AFTERNOON. NOT MUCH
OF A TRIGGER TOMORROW AFTERNOON AS MID LEVEL TROUGH REMAINS WELL
TO THE WEST ALONG WITH ATTENDING COLD FRONT. THUS THINKING AREAL
COVERAGE OF ANY SHOWERS WILL BE ISOLATED TO WIDELY SCATTERED.
GIVEN MU CAPES ARE ONLY 500J/KG OR LESS ALONG WITH MARGINAL WIND
FIELDS ALOFT...ANY TSTMS SHOULD BE ISOLATED AND NON SEVERE. GIVEN
THE HIGHER PWAT AIRMASS CAN`T RULE OUT A BRIEF HEAVY DOWNPOUR.
OTHERWISE A TYPICAL LATE WARM SPRING AFTERNOON WITH ISOLATED-
WIDELY SCATTERED SHOWERS. ANY MORNING FOG WILL BURN OFF BY MIDDAY.
SATURDAY NIGHT...SHOWERS MAY BECOME MORE WIDESPREAD AS COLD FRONT
APPROACHES ALONG WITH POSSIBLE SURFACE WAVE ON THE FRONT. THIS
WOULD RESULT IN SHOWERS MOST NUMEROUS ALONG THE SOUTH COAST. LOW
RISK OF AN ISOLATED TSTM WITH HEAVY RAINFALL. IMPROVING CONDITIONS
TOWARD 12Z SUN FROM WEST TO EAST. GIVEN POST FRONTAL AIRMASS
DOESNT ARRIVE UNTIL SUNDAY IT WILL BE A MILD NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...
* DRY...WARM WEATHER FOR MOTHERS DAY AND MONDAY
* BACKDOOR COLD FRONT MOVES INLAND MONDAY NIGHT INTO TUESDAY WITH
SCATTERED SHOWERS
* NEAR TO BELOW NORMAL TEMPS WITH SPOTTY SHOWERS WEDNESDAY
THROUGH FRIDAY
MODEL CONFIDENCE AND PREFERENCES...
NOTING THAT THE 06Z AND 12Z GFS OP RUNS ALONG WITH 12Z GGEM HAVE
COME ON BOARD WITH THE LAST SEVERAL RUNS OF THE ECMWF WITH MAJOR
CHANGES IN THE UPPER LEVEL LONG WAVE PATTERN EARLY NEXT WEEK. NOW
EXPECTING A BUILDING RIDGE ACROSS THE EASTERN U.S. WITH DEEPENING
TROUGH OVER THE CENTRAL U.S. EARLY NEXT WEEK. AS THE RIDGE BUILDS
ALOFT...SURFACE RIDGING ALSO BUILDS ACROSS QUEBEC AND LABRADOR
THEN SHIFTS DOWN THE ATLC COAST...CAUSING A BACKDOOR COLD FRONT
TO CROSS THE REGION FROM NE TO SW AROUND THE LATE MON NIGHT OR TUE
TIMEFRAME. THE FRONT WILL TEND TO STALL MAINLY ACROSS
EASTERN/CENTRAL NY STATE INTO N NJ. SO...WILL LIKELY SEE NEAR OR
BELOW NORMAL TEMPS IN THE MID TO LATTER PORTIONS OF NEXT WEEK WITH
MARITIME AIR OFF THE COLD OCEAN /SEA SURFACE TEMPS IN THE UPPER
40S/. TIMING OF MIGRATION OF THE UPPER TROUGH EASTWARD OUT OF THE
GREAT LAKES AND OHIO VALLEY LATE NEXT WEEK LENDS TO LOWER
CONFIDENCE WITH THE APPROACH OF SURFACE COLD FRONT AS IT BUMPS INTO
THE HIGH AMPLITUDE SURFACE AND UPPER RIDGES.
USED A BLEND OF MOST MODEL GUIDANCE FOR THIS PACKAGE...INCLUDING
WPC GUIDANCE WHICH ALSO INCORPORATED ENSEMBLE MEANS.
DETAILS...
SUNDAY...
WILL SEE A DRY AND MILD SPRING DAY FOR MOTHERS DAY AS WEAK HIGH
PRES RIDGE CROSSES THE REGION. WILL BE A BREEZY DAY WITH W WINDS
GUSTING UP TO 20-25 MPH...HIGHEST WELL INLAND. EXPECT HIGHS MAINLY
IN THE 70S...EXCEPT A BIT COOLER ALONG THE IMMEDIATE COAST. CLOUDS
WILL START TO INCREASE ACROSS N CT/W MA AFTER MIDNIGHT.
MONDAY...
ISENTROPIC LIFT MOVES IN ACROSS THE REGION AS WARM FRONT BEGINS TO
APPROACH. HOWEVER...AS RIDGING BUILDS TO THE W...THIS FRONT HANGS
UP ACROSS THE REGION. EXPECT SOME SCT SHOWERS TO MOVE ACROSS MON
AFTERNOON/NIGHT. ALSO NOTING SOME ELEVATED CONVECTION POSSIBLE
ALONG WITH LIFTED INDICES DROPPING AT OR BELOW ZERO AS THE DAY
PROGRESSES. HAVE ALSO MENTIONED ISOLD THUNDER. COULD BE A RATHER
MILD DAY WITH SOME READINGS POSSIBLY CLOSE TO 80 WELL
INLAND...BUT UNCERTAIN OF THIS DUE TO STALLING FRONT ACROSS THE
REGION. CURRENT MODELS SUGGEST THAT HIGH PRES WILL BEGIN TO SURGE
DOWN FROM MAINE LATE MON NIGHT...SO STALLED FRONT COULD BEGIN TO
SHIFT S-SW. SOMETHING TO MONITOR.
TUESDAY...
MODELS HAVE COME IN LINE IN PUSHING BACKDOOR FRONT ACROSS THE
REGION...FROM NE-SW DURING THE DAY. WILL STILL SEE SOME SCT
SHOWERS BUT SHOULD PUSH FROM E TO W DURING THE AFTERNOON. MAY
STILL SEE SOME ISOLD THUNDER ACROSS N CT/RI THROUGH ABOUT
MIDDAY...THEN WILL PUSH OFF THE S COAST. E-NE WINDS WILL BE GUSTY
ALONG THE E COAST...POSSIBLY UP TO AROUND 25 MPH DURING TUE
AFTERNOON/EVENING. TEMPS WILL RANGE FROM THE UPPER 50S TO MID 60S
ALONG THE E COAST TO THE LOWER-MID 70S ACROSS THE CT VALLEY. WILL
BE CHILLY TUE NIGHT WITH LOWS MAINLY IN THE MID-UPPER 40S WITH
SOME LOWER 50S IN THE LOWER CT VALLEY.
WEDNESDAY THROUGH FRIDAY...
LARGE H5 RIDGING BUILDS ACROSS THE EASTERN U.S. WHILE TROUGH DIGS
ACROSS CENTRAL AREAS. THIS WILL SLOW SURFACE SYSTEMS DOWN AS FRONT
STALLS ACROSS EASTERN NY STATE INTO N NJ. EXPECT SLIGHT CHANCE TO
LOW CHANCE POPS TO LINGER ACROSS CT VALLEY AND E SLOPES OF THE
BERKSHIRES INTO WED NIGHT...THEN MAY START TO SHIFT E AS UPPER
TROUGH/SURFACE COLD FRONT MAY START TO APPROACH THOUGH TIMING IS
IN QUESTION. EXPECT HIGHS EACH DAY TO RUN CLOSE TO OR UP TO 5
DEGS BELOW SEASONAL NORMS.
MODELS DO DIVERGE ON HOW IT RESOLVES THEIR TIMING OF THE UPPER
TROUGH INTO THE EASTERN U.S...POSSIBLY NOT UNTIL NEXT WEEKEND.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH FRIDAY NIGHT/...LOW CONFIDENCE.
THRU 00Z...LOW CONFIDENCE FORECAST AS TIMING OF IFR CONDITIONS
IMPROVING TO MVFR STILL SOMEWHAT UNCERTAIN. WHERE IFR EXISTS NOW
THINK WE WILL SEE SOME BRIEF IMPROVEMENT TO MVFR AFTER 21Z AS
WINDS SHIFT FROM NE TO SE. ELSEWHERE MVFR SHOULD PREVAIL. AS FOR
THE CT RVR VLY MARGINAL IFR/MVFR WILL CONTINUE. PATCHY FOG AND
DRIZZLE POSSIBLE ALL TERMINALS. ALTHOUGH HEAVY RAIN/THUNDER NOT
EXPECTED.
AFTER 00Z...MVFR WILL TREND TO IFR AS THE NIGHT PROGRESSES.
PATCHY FOG AND DRIZZLE POSSIBLE ALL TERMINALS. BETTER CHANCE OF
WIDESPREAD RAIN TOWARD MORNING. VERY LOW RISK OF ISOLATED THUNDER
TOWARD 12Z.
SATURDAY...ANY LEFTOVER IFR IN THE MORNING WILL LIFT TO MVFR OR
EVEN VFR TOWARD MIDDAY AND ESPECIALLY DURING THE AFTERNOON.
ISOLATED-SCATTERED SHOWERS EARLY ACROSS EASTERN MA AND RI. THEN
ANOTHER ROUND OF ISOLATED-SCATTERED SHOWERS DURING THE AFTERNOON
WITH A VERY LOW RISK OF AN ISOLATED TSTM.
SAT NIGHT...SHOWERS SHOULD BECOME MORE NUMEROUS ESPECIALLY ALONG
THE SOUTH COAST. SOME HEAVY RAIN POSSIBLE. AS FOR CIGS/VSBYS ANY
EARLY VFR CONDITIONS QUICKLY LOWER TO MVFR AND EVENTUALLY IFR
OVERNIGHT FROM WEST TO EAST.
KBOS TERMINAL...LOW CONFIDENCE. IFR SHOULD LIMIT BRIEFLY TO MVFR
AFTER 21Z AS WINDS SHIFT FROM NE TO SE AND THEN S. MVFR LOWERS TO
IFR LATER TONIGHT AS SHOWERS BECOME MORE NUMEROUS TOWARD 12Z SAT.
THEN CONDITIONS IMPROVE TO MVFR AND EVENTUALLY VFR SAT AFTERNOON.
ISOLATED-SCATTERED AFTERNOON SHOWERS.
KBDL TERMINAL...LOW CONFIDENCE. IFR CONDITIONS IN THE CT RVR VLY
SHOULD LIFT TO MVFR BRIEFLY THIS EVENING BEFORE LOWERING AGAIN
LATER TONIGHT AS SHOWERS BECOME MORE NUMEROUS.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY...HIGH CONFIDENCE. VFR CONDITIONS. W WIND GUSTS UP TO 20-25
KT POSSIBLE. PATCHY FOG POSSIBLE ALONG IMMEDIATE S COAST LATE SUN
NIGHT WITH LOCAL MVFR-IFR VSBYS.
MONDAY...MODERATE CONFIDENCE.
VFR CONDITIONS TO START. MAY SEE SCT SHOWERS/ISOLD TSTMS DURING
MONDAY AFTERNOON/NIGHT WITH LOCAL MVFR-IFR CIGS/VSBYS. PATCHY FOG
LATE MON NIGHT WITH MVFR-IFR VSBYS MAINLY ALONG S COAST.
TUESDAY...LOW TO MODERATE CONFIDENCE...MAINLY FOR TIMING.
BACK DOOR COLD FRONT WILL SHIFT FROM NE TO SW DURING TUE. WINDS
SHIFT FROM LIGHT W TO E-NE FROM E MA WESTWARD. GUSTS UP TO 20-25
KT MAINLY ALONG E COAST. WILL SEE VFR CONDITIONS...BUT MAY SEE
LOWER CLOUDS WITH POCKETS OF FOG AND DRIZZLE ACROSS E MA DURING
TUE AFTERNOON/NIGHT. MVFR-IFR CONDITIONS POSSIBLE. LEFTOVER SCT
SHOWERS/ISOLD THUNDER INTO TUE EVENING...THEN SHIFTS W.
WEDNESDAY...LOW TO MODERATE CONFIDENCE.
WIDELY SCT SHOWERS LINGER ACROSS CT VALLEY TO E SLOPES OF
BERKSHIRES WED...WHILE POCKETS OF MVFR-IFR CIGS/VSBYS POSSIBLY
LINGER ACROSS E COASTAL AREAS WITH ONSHORE WINDS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...MODERATE CONFIDENCE.
TONIGHT...NE/SE WINDS BECOME SSW LATER TONIGHT. PATCHY FOG AND
DRIZZLE MAY LOWER VSBY 1-3 MILES WITH A LOW RISK OF DENSE FOG
SOUTH COASTAL WATERS. SHOWERS BECOME MORE WIDESPREAD TOWARD
DAYBREAK.
SATURDAY...WARM FRONT LIFTS NORTH OF THE REGION WITH WINDS
BECOMING SSW 15-20 KT WITH A FEW GUSTS APPROACHING 25 KT NEAR
SHORE. NO SMALL CRAFT ADVISORY AT THE MOMENT AS DURATION AND
FREQUENCY OF 25 KT REMAINS SOMEWHAT UNCERTAIN. ISOLATED-WIDELY
SCATTERED SHOWERS. VERY LOW RISK OF ISOLATED TSTM NEAR SHORE. ANY
MORNING FOG SHOULD BURN OFF BY EARLY AFTERNOON.
SAT NIGHT...COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS
BECOMING MORE WIDESPREAD. VSBY SHOULD BE GOOD GIVEN SW WINDS.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
MODERATE CONFIDENCE THROUGH PERIOD.
SUNDAY...
HIGH PRES RIDGE BUILDS ACROSS THE WATERS. EXPECT W WINDS 15 KT OR
LESS INTO SUN NIGHT. MAY SEE W GUSTS CLOSE TO 25 KT ON NEARSHORE
WATERS DURING THE AFTERNOON. SEAS SHOULD REMAIN BELOW 5 FT. VSBY
RESTRICTIONS LATE SUN NIGHT POSSIBLE ALONG IMMEDIATE S COASTAL
WATERS.
MONDAY...
FRONT APPROACHES THE WATERS BUT STALLS. S-SW WINDS REMAIN AT 15 KT
OR LESS...THEN DIMINISH INTO MON NIGHT AS BACKDOOR FRONT
APPROACHES. NOTING WIND SHIFT TO N OVER THE EASTERN OUTER WATERS
AFTER MIDNIGHT. COULD SEE SCT SHOWERS/ISOLD THUNDER MON
AFTERNOON/NIGHT WITH FRONT IN VICINITY.
TUESDAY-WEDNESDAY...
BACKDOOR FRONT MOVES SW ACROSS THE WATERS TUE. WINDS SHIFT TO
NE...GUSTING UP TO AROUND 20 KT ON THE OPEN WATERS BEGINNING TUE
AFTERNOON THROUGH WED. EXPECT E-NE SWELLS TO BUILD TO AROUND 5 FT
ON THE OUTER WATERS. SCT SHOWERS/ISOLD THUNDER STILL POSSIBLE INTO
TUE EVENING BUT WILL SHIFT SW AS FRONT PASSES TUE NIGHT.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NOCERA/EVT
NEAR TERM...NOCERA
SHORT TERM...EVT
LONG TERM...EVT
AVIATION...NOCERA/EVT
MARINE...NOCERA/EVT
AREA FORECAST DISCUSSION
NWS TAUNTON MA
348 PM EDT FRI MAY 9 2014
.SYNOPSIS...
A WARM FRONT WILL APPROACH TONIGHT BRINGING A PERIOD OF SCATTERED
SHOWERS BEFORE IT LIFTS INTO NORTHERN NEW ENGLAND SATURDAY. BEHIND
THE FRONT A WARMER AND MORE HUMID AIRMASS OVERSPREADS THE REGION
SATURDAY. A COLD FRONT WILL MOVE ACROSS THE AREA LATE SATURDAY
NIGHT INTO EARLY SUNDAY MORNING...YIELDING A ROUND OF SCATTERED
SHOWERS. HIGH PRESSURE BUILDS IN FOR MOTHERS DAY. MILD TEMPERATURES
AND UNSETTLED WEATHER ARE ANTICIPATED FOR MOST OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
345 PM UPDATE...
WARM FRONT ACROSS WESTERN PA AND NY WILL APPROACH THE REGION LATER
TONIGHT. BEFORE THEN COOL PREFRONTAL AIRMASS REMAINS OVER SOUTHERN
NEW ENGLAND AS ONSHORE FLOW MAINTAINS COOL MOIST SHALLOW AIRMASS.
WATER VAPOR IMAGERY ALONG WITH MODEL CROSS SECTIONS AND TIME
SECTIONS REVEAL MID LEVEL DRY AIR OVERSPREAD THE REGION AS WELL.
THIS COMBINED WITH MOIST SHALLOW ONSHORE FLOW IS RESULTING IN
AREAS OF DRIZZLE AND FOG ESPECIALLY IN THE CT RVR VLY AND THE
HIGHER TERRAIN /UPSLOPE FLOW/. THIS WILL BECOME MORE WIDESPREAD
THIS EVENING ESPECIALLY WITH SUNSET. THUS NO APPRECIABLE RAINFALL
THIS EVENING. NOT A WASHOUT JUST SPOTTY LIGHT RAIN/DRIZZLE. LAST
SEVERAL RUNS OF THE HRRR SUPPORT THIS THINKING AS WELL.
LATER TONIGHT WARM FRONT ENTERS THE REGION WITH RAIN BECOMING
MORE WIDESPREAD AS MODELS INDICATE MODEST ISENTROPIC LIFT/UPGLIDE
ACROSS THE REGION 06-12Z. MARINGAL INSTABILITY ALOFT TO SUPPORT A
VERY LOW RISK OF AN ISOLATED TSTM WITH LOCALLY BRIEF HEAVY
DOWNPOUR TOWARD SUNRISE. HOWEVER MUCH OF THE ACTIVITY SHOULD BE ON
THE LIGHT SIDE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
SATURDAY...WARM FRONT LIFTS NORTH OF THE REGION BY MID TO LATE
MORNING WITH WARM SECTOR OVERSPREADING SOUTHERN NEW ENGLAND.
DEFINITELY A BIT OF A SUMMER-ISH FEEL TO THE AIRMASS TOMORROW WITH
MAY SUNSHINE LIFTING TEMPS INTO THE 70S AND DEW PTS IN THE L60S.
AS FOR INSTABILITY DETERMINISTIC AND ENSEMBLE GUIDANCE SUGGEST
ONLY 200-500 J/KG OF MU AND MEAN CAPE TOMORROW AFTERNOON. NOT MUCH
OF A TRIGGER TOMORROW AFTERNOON AS MID LEVEL TROUGH REMAINS WELL
TO THE WEST ALONG WITH ATTENDING COLD FRONT. THUS THINKING AREAL
COVERAGE OF ANY SHOWERS WILL BE ISOLATED TO WIDELY SCATTERED.
GIVEN MU CAPES ARE ONLY 500J/KG OR LESS ALONG WITH MARGINAL WIND
FIELDS ALOFT...ANY TSTMS SHOULD BE ISOLATED AND NON SEVERE. GIVEN
THE HIGHER PWAT AIRMASS CAN`T RULE OUT A BRIEF HEAVY DOWNPOUR.
OTHERWISE A TYPICAL LATE WARM SPRING AFTERNOON WITH ISOLATED-
WIDELY SCATTERED SHOWERS. ANY MORNING FOG WILL BURN OFF BY MIDDAY.
SATURDAY NIGHT...SHOWERS MAY BECOME MORE WIDESPREAD AS COLD FRONT
APPROACHES ALONG WITH POSSIBLE SURFACE WAVE ON THE FRONT. THIS
WOULD RESULT IN SHOWERS MOST NUMEROUS ALONG THE SOUTH COAST. LOW
RISK OF AN ISOLATED TSTM WITH HEAVY RAINFALL. IMPROVING CONDITIONS
TOWARD 12Z SUN FROM WEST TO EAST. GIVEN POST FRONTAL AIRMASS
DOESNT ARRIVE UNTIL SUNDAY IT WILL BE A MILD NIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...
* DRY...WARM WEATHER FOR MOTHERS DAY
* AVERAGE TEMPERATURES AND UNSETTLED WEATHER FOR THE WORK WEEK
MODELS AND CONFIDENCE...
00Z GUIDANCE AGREES THAT A ROCKIES/PLAINS TROUGH WILL BROADEN AS IT
MOVES EWD WITH TIME... YIELDING A MEAN TROUGH COVERING MUCH OF THE
ERN HALF OF THE CONUS/CANADA BY LATE NEXT WEEK. HOWEVER
SIGNIFICANT DIFFERENCES EXIST FOR SOME DETAILS WITHIN THIS
EVOLUTION...CAUSING A LOW CONFIDENCE FORECAST. THE MOST PRONOUNCED
IS A FASTER ADVANCE OF THE INITIAL TROUGH IN RECENT GFS/GEFS RUNS
WITH TRENDS AND OTHER MODELS GENERALLY SUPPORTING SLOWER TIMING.
THEREFORE TRENDED TOWARDS PREVIOUS FORECAST AND WPC. OVERALL HAVE
A MEDIUM CONFIDENCE THAT POP-UP SHOWERS AND ISO THUNDERSTORMS WILL
OCCUR ON MONDAY...BUT A LOW CONFIDENCE BEYOND THAT.
DETAILS...
SUNDAY...
COLD FRONT WILL CROSS THE REGION OVERNIGHT SATURDAY INTO SUNDAY
MORNING. A FEW SCT SHOWERS AND MAYBE AN ISO TSTORM ARE POSSIBLE
ALONG THE FRONT. COLD FRONT SHOULD BE OFFSHORE BY 12Z SUNDAY
ALLOWING FOR SURFACE HIGH PRESSURE TO BUILD IN TO THE AREA FOR
MOTHERS DAY. SUBSIDENCE WILL FILTER IN WITH THE HIGH PRESSURE
ALLOWING FOR DRY WEATHER. FORECAST SOUNDINGS SUGGEST MIXING CLOSE TO
850MB TEMPS WHICH WILL YIELD TO GUSTS NEAR 20-25 MPH. TEMPS COULD
REACH THE UPPER 70S TO LOW 80S AWAY FROM THE COASTS AS 850 MB
TEMPS STAY ABOUT 8C BEHIND THE FRONT. SUNDAY IS THE PICK OF THE
WEEK.
MONDAY AND TUESDAY...
WARM...MOIST AIRMASS IN PLACE ACROSS THE REGION FOR MONDAY AND
TUESDAY. GUIDANCE IS SHOWING A WARM FRONT TRYING TO APPROACH THE
REGION WHICH COULD SPARK SOME SCATTERED SHOWERS AND ISO
THUNDERSTORMS DURING DIURNAL HEATING...ESP ON MONDAY. SURFACE
CAPE VALUES WILL REACH NEAR 1000 J/KG AND WITH SHOWALTERS DROPPING
BELOW 0 HAVE INSERTED THE MENTION FOR THUNDER.
THE EC AND GFS BEGIN TO DIVERGE AT THIS POINT AS THE EC DROPS A BACK
DOOR COLD FRONT ACROSS NEW ENGLAND ON TUESDAY. THE GFS ALSO HINTS AT
THIS BUT IS NOT AS STRONG AS THE EC. BETWEEN THESE 2 FORECAST
GUIDANCE...THERE IS A 20F SURFACE HIGH TEMP DIFFERENCE FOR TUESDAY.
THE CANADIAN AND A FEW MEMBERS OF THE GEFS ALSO DISPLAYS THIS
BACK DOOR FRONT PUSHING ALL THE WAY THROUGH THE AREA...AS WELL AS
WPC. BECAUSE OF THIS TREND HAVE BEGUN CUTTING TEMPS FOR TUESDAY
AND DISPLAYING THE POSSIBILITY OF THE BACK DOOR FRONT. ALTHOUGH IT
MAY BE COOLER THEN FORECASTED...RIGHT NOW JUST SETTLING ON A
TREND.
WEDNESDAY AND BEYOND...
BY WEDNESDAY...A DEEP UPPER TROUGH THAT HAS DUG ACROSS THE CENTRAL
CONUS HAS MOVED EASTWARD OVER THE MIDWEST. THIS TROUGH WILL CONTINUE
TO SLOWLY TRACK EASTWARD DURING THE REST OF THE WEEK. EXPECT SEVERAL
WEAK WAVES TO DEVELOP AHEAD OF THIS TROUGH AND WILL APPROACH THE
AREA DURING THIS TIMEFRAME. AS A RESULT...HAVE CONTINUED TO
MENTION THE POSSIBILITY OF A CHANCE OF POPS FOR SHOWERS/TSTMS FROM
WEDNESDAY THROUGH FRIDAY. MODEL GUIDANCE INDICATES THE TROUGH WILL
SLIDE OFFSHORE BY EITHER FRIDAY OR SATURDAY.
A MILD AIR MASS OVERSPREADS THE REGION WITH SW FLOW AHEAD OF THE
TROUGH. HIGHS WILL GENERALLY TOP OFF IN THE UPPER 60S TO LOW 70S
WITH COOLER CONDITIONS ALONG THE COAST...ESP THE SOUTH COAST DUE TO
SOUTHERLY FLOW.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH FRIDAY NIGHT/...LOW CONFIDENCE.
THRU 00Z...LOW CONFIDENCE FORECAST AS TIMING OF IFR CONDITIONS
IMPROVING TO MVFR STILL SOMEWHAT UNCERTAIN. WHERE IFR EXISTS NOW THINK
WE WILL SEE SOME BRIEF IMPROVEMENT TO MVFR AFTER 21Z AS WINDS
SHIFT FROM NE TO SE. ELSEWHERE MVFR SHOULD PREVAIL. AS FOR THE CT
RVR VLY MARGINAL IFR/MVFR WILL CONTINUE. PATCHY FOG AND DRIZZLE
POSSIBLE ALL TERMINALS. ALTHOUGH HEAVY RAIN/THUNDER NOT EXPECTED.
AFTER 00Z...MVFR WILL TREND TO IFR AS THE NIGHT PROGRESSES. PATCHY
FOG AND DRIZZLE POSSIBLE ALL TERMINALS. BETTER CHANCE OF
WIDESPREAD RAIN TOWARD MORNING. VERY LOW RISK OF ISOLATED
THUNDER TOWARD 12Z.
SATURDAY...ANY LEFTOVER IFR IN THE MORNING WILL LIFT TO MVFR OR
EVEN VFR TOWARD MIDDAY AND ESPECIALLY DURING THE AFTERNOON.
ISOLATED-SCATTERED SHOWERS EARLY ACROSS EASTERN MA AND RI. THEN
ANOTHER ROUND OF ISOLATED-SCATTERED SHOWERS DURING THE AFTERNOON
WITH A VERY LOW RISK OF AN ISOLATED TSTM.
SAT NIGHT...SHOWERS SHOULD BECOME MORE NUMEROUS ESPECIALLY ALONG
THE SOUTH COAST. SOME HEAVY RAIN POSSIBLE. AS FOR CIGS/VSBYS ANY
EARLY VFR CONDITIONS QUICKLY LOWER TO MVFR AND EVENTUALLY IFR
OVERNIGHT FROM WEST TO EAST.
KBOS TERMINAL...LOW CONFIDENCE. IFR SHOULD LIMIT BRIEFLY TO MVFR
AFTER 21Z AS WINDS SHIFT FROM NE TO SE AND THEN S. MVFR LOWERS TO
IFR LATER TONIGHT AS SHOWERS BECOME MORE NUMEROUS TOWARD 12Z SAT.
THEN CONDITIONS IMPROVE TO MVFR AND EVENTUALLY VFR SAT AFTERNOON.
ISOLATED-SCATTERED AFTERNOON SHOWERS.
KBDL TERMINAL...LOW CONFIDENCE. IFR CONDITIONS IN THE CT RVR VLY
SHOULD LIFT TO MVFR BRIEFLY THIS EVENING BEFORE LOWERING AGAIN
LATER TONIGHT AS SHOWERS BECOME MORE NUMEROUS.
OUTLOOK...SUNDAY THROUGH TUESDAY...
SUNDAY...MODERATE CONFIDENCE. COLD FRONTAL PASSAGE WILL ALLOW FOR
SCT SHOWERS AND POSSIBLE MVFR CIGS AND VSBYS. THERE IS A LOW PROB
OF A TSRA...WITH OVER THE CAPE AND ISLANDS HAVING THE BEST SHOT
DURING THIS TIMEFRAME. OTHERWISE IMPROVING CONDITIONS FROM WEST TO
EAST ON SUNDAY. GUSTY WINDS UP TO 25 KTS POSSIBLE.
MONDAY-TUESDAY...MODERATE CONFIDENCE.
VFR CONDITIONS TO START. MAY SEE POP-UP SHOWERS AND THUNDERSTORMS
DURING THE DAY DROPPING VSBYS AND CIGS. POSSIBLE BACK DOOR COLD
FRONT ON TUESDAY SWITCHING THE WESTERLY WINDS TO THE EAST ALLOWING
FOR FOG AND DRIZZLE TO ROLL IN.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY NIGHT/...MODERATE CONFIDENCE.
TONIGHT...NE/SE WINDS BECOME SSW LATER TONIGHT. PATCHY FOG AND
DRIZZLE MAY LOWER VSBY 1-3 MILES WITH A LOW RISK OF DENSE FOG
SOUTH COASTAL WATERS. SHOWERS BECOME MORE WIDESPREAD TOWARD
DAYBREAK.
SATURDAY...WARM FRONT LIFTS NORTH OF THE REGION WITH WINDS
BECOMING SSW 15-20 KT WITH A FEW GUSTS APPROACHING 25 KT NEAR
SHORE. NO SMALL CRAFT ADVISORY AT THE MOMENT AS DURATION AND
FREQUENCY OF 25 KT REMAINS SOMEWHAT UNCERTAIN. ISOLATED-WIDELY
SCATTERED SHOWERS. VERY LOW RISK OF ISOLATED TSTM NEAR SHORE. ANY
MORNING FOG SHOULD BURN OFF BY EARLY AFTERNOON.
SAT NIGHT...COLD FRONT APPROACHES FROM THE WEST WITH SHOWERS
BECOMING MORE WIDESPREAD. VSBY SHOULD BE GOOD GIVEN SW WINDS.
OUTLOOK...SUNDAY THROUGH TUESDAY...
MODERATE CONFIDENCE THROUGH PERIOD.
SUNDAY...COLD FRONT WILL PUSH OVER THE WATERS BY SUNDAY MORNING
ALLOW FOR SCT SHOWERS AND SOME ISO THUNDER. SEAS WILL REMAIN AT OR
NEAR 5 FT. SCA MAY STILL BE NEEDED ESP ACROSS NEAR SHORE WATERS ON
SUNDAY AS THE LAND MAY GUST UP TO 25KTS.
MONDAY-TUESDAY...
WARM FRONT WILL APPROACH FROM THE SOUTH ALLOWING FOR SCT SHOWERS
AND ISO THUNDER. BEST CHANCES ARE IN THE BAY AND HARBORS.
OTHERWISE WESTERLY WINDS WILL SHIFT TO THE EAST ON TUESDAY AS BACK
DOOR COLD FRONT MOVES ACROSS THE WATERS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NOCERA
NEAR TERM...NOCERA
SHORT TERM...NOCERA
LONG TERM...DUNTEN
AVIATION...NOCERA/DUNTEN
MARINE...NOCERA/DUNTEN
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
250 PM EDT FRI MAY 9 2014
.SYNOPSIS...
18Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUES TO SHOW AN AMPLIFIED
UPPER LEVEL PATTERN IN PLACE ACROSS THE CONUS. LONGWAVE TROUGHING
SITS OVER THE CENTRAL PLAINS WITH A POTENT SHORTWAVE IMPULSE
PIVOTING NORTHWARD OVER THE UPPER MS VALLEY/WESTERN GREAT LAKES. THE
DOWNSTREAM FLOW THEN RIDGES UP OVER THE EASTERN SEABOARD EXTENDING
FROM THE EASTERN GULF/FLORIDA PENINSULA TO QUEBEC. WV IMAGERY SHOWS
A BIT MORE UPPER LEVEL MOISTURE HAS WORKED OVERHEAD COMPARED TO
PREVIOUS DAYS...AND THIS WILL COME IN THE FORM OF PERIODIC CIRRUS.
THIS HIGH LEVEL MOISTURE IS SHOWN ON THE 12Z KTBW SOUNDING ABOVE
400MB...HOWEVER BELOW THIS LEVEL...THE SUPPRESSION FROM THE UPPER
RIDGE CONTINUES TO SUPPLY US WITH A DRY COLUMN THROUGH A MAJORITY OF
THE TROP.
AT THE SURFACE...RIDGE OF HIGH PRESSURE CENTERED OVER THE WESTERN
ATLANTIC CONTINUES TO RIDGE BACK TO THE WEST WITH AN AXIS NEAR THE
I-10 CORRIDOR. OUR POSITION TO THE SOUTH OF THIS RIDGE AXIS IS
PROVIDING A LIGHT SOUTHEAST SYNOPTIC FLOW TO THE REGION.
HOWEVER...AT THE COAST WINDS HAVE SHIFTED ONSHORE WITH THE
DEVELOPMENT OF THE AFTERNOON SEA-BREEZE. TEMPERATURES ARE IN THE
UPPER 80S TO LOWER 90S ACROSS THE INTERIOR AND IN THE LOWER TO
MIDDLE 80S AT THE BEACHES. EARLY SHALLOW CU FIELD THAT WAS TRYING TO
DEVELOP HAS NOW ESSENTIALLY DISSIPATED AS THE BOUNDARY LAYER HAS
MIXED UP INTO THE SIGNIFICANTLY DRIER AIR ALOFT. EXPECT MOSTLY SUNNY
SKIES TO NOW PREVAIL FOR THE REMAINDER OF THE DAYLIGHT HOURS.
.SHORT TERM (TONIGHT THROUGH SATURDAY)...
TONIGHT...
SHORTWAVE ENERGY RIDING NORTHWARD FROM THE WESTERN GULF OF MEXICO TO
THE FLORIDA PANHANDLE/GEORGIA VICINITY WILL DE-AMPLIFY THE UPPER
RIDGE AND BEGIN TO SHIFT ITS AXIS SOUTH AND SOUTHEAST. BY MORNING
THE UPPER RIDGE AXIS WILL BE DOWN OVER SOUTH FLORIDA. THE SURFACE
RIDGE WILL REMAIN IN PLACE WITH A LIGHT SOUTHEAST FLOW OVER THE
AREA. THIS FLOW LOOKS TO REMAIN STRONG ENOUGH (ESPECIALLY JUST ABOVE
THE SURFACE) TO SUPPRESS ANY SIGNIFICANT FOG DEVELOPMENT. THIS IS
SHOWN IN THE SREF VISIBILITY PROBS OVERNIGHT WHICH ARE UNDER 10% FOR
VIS < 3 MILES. A MILD NIGHT UPCOMING WITH LOWS GENERALLY IN THE
UPPER 60S TO LOWER 70S. SHOULD GET DOWN INTO THE MIDDLE 60S FOR
INLAND LEVY COUNTY. NORMALLY WARMER SPOTS ALONG THE COAST SUCH AS ST
PETE WILL HOLD IN THE MIDDLE 70S.
SATURDAY...
A DECENT DAY IN TERMS OF SENSIBLE WEATHER ON TAP TO START OUT THE
WEEKEND. UPPER RIDGE AXIS WILL HAVE SHIFTED SOUTH OF THE AREA...SO A
LITTLE LESS SYNOPTIC SUPPRESSION AND HENCE THE COLUMN WILL BE ABLE
TO BEGIN MOISTENING THROUGH A GREATER DEPTH. SATURDAY LOOKS TO HAVE
A MIX OF SUN AND CLOUDS IN THE MORNING DUE TO PASSING HIGHER LEVEL
CIRRUS...AND THEN DUE TO A SCT-BKN CUMULUS FIELD DEVELOPING IN THE
LATE MORNING AND AFTERNOON. OVERALL THE COLUMN IS STILL FAIRLY
HOSTILE TO DEEP CONVECTION DUE TO ENTRAINMENT OF DRY
AIR...HOWEVER...NOT QUITE AS HOSTILE AS TODAY AND THE PAST COUPLE OF
DAYS. THEREFORE...AS THE SEA-BREEZE MOVES INLAND...THE LOW LEVEL
FOCUS WILL HAVE A SLIGHTLY BETTER CHANCE OF KICKING OFF A FEW WIDELY
SCT SHOWERS DURING THE MIDDLE TO LATE AFTERNOON. MOST OF THE HIRES
CONVECTION ALLOWING GUIDANCE ARE SHOWING A LEAST THIS ISOLATED
SHOWER VARIETY...BUT WITH BRIEF LIFE CYCLES DUE TO THE STILL FAIRLY
DRY AIR ALOFT. GRIDS/FORECAST WILL SHOW A 20-30% CHANCE OF THESE
LATE DAY SHOWERS...GENERALLY OVER THE INTERIOR...INLAND FROM THE
I-75 CORRIDOR. TEMPERATURES SHOULD BE SIMILAR WITH WIDESPREAD UPPER
80S INLAND AND LOWER TO MIDDLE 80S AT THE BEACHES. ENJOY THE WEEKEND
EVERYONE!
&&
.MID TERM (SUNDAY)...
HIGH PRESSURE WILL REMAIN THE DOMINANT WEATHER FEATURE FOR THE
SECOND HALF OF THE WEEKEND. THE EAST/WEST COAST SEA BREEZES
SHOULD BE ENOUGH TO SPARK ISOLATED TO WIDELY SCATTERED SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON...SO WILL INCLUDE SLIGHT
CHANCE/LOW CHANCE POPS IN THE FORECAST FOR MOST LOCATIONS. HIGH
TEMPERATURES WILL GENERALLY TOP OUT IN THE UPPER 80S TO LOWER
90S...WITH LOWS RANGING FROM THE MID TO UPPER 60S ACROSS THE
INTERIOR COOL SPOTS TO THE LOWER 70S ALONG THE COAST.
&&
.LONG TERM (SUNDAY NIGHT-FRIDAY)...
MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT THROUGH EARLY NEXT
WEEK...WITH SOLUTIONS THEN DEVIATING WITH RESPECT TO THE HANDLING
OF AN EASTERLY WAVE DURING THE MIDDLE TO LATTER PORTION OF NEXT
WEEK. WILL FOLLOW A BLENDED APPROACH TO THE FORECAST GIVEN THE
UNCERTAINTY...AND THIS WILL RESULT IN CHANCES FOR MAINLY
AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE
LONG TERM PERIOD. AT THIS POINT...IT APPEARS THAT THE HIGHEST
PROBABILITIES FOR RAINFALL WILL FALL IN THE WEDNESDAY/THURSDAY
TIME FRAME WHEN THE DEEPEST MOISTURE WILL BE IN PLACE.
TEMPERATURES ARE EXPECTED TO RUN CLOSE TO NORMAL THROUGH THE LONG
TERM PERIODS.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH THE REST OF THE AFTERNOON AND
EVENING. SOUTHEAST FLOW OVERNIGHT LOOKS TO REMAIN ELEVATED ENOUGH TO
PREVENT MUCH IN THE WAY OF FOG DEVELOPMENT. NOT OUT OF THE QUESTION
TO SEE A BRIEF MVFR PERIOD AT KLAL OR KPGD TOWARD SUNRISE ON
SATURDAY...HOWEVER AT THIS TIME CONFIDENCE OF REDUCED VISIBILITIES
AT EITHER TERMINAL ARE LOW ENOUGH TO KEEP MENTION OUT OF THE TAFS.
&&
.MARINE...
WINDS WILL SHIFT BACK TO THE SOUTHEAST OVERNIGHT AND BECOME
BREEZY ONCE AGAIN...HOWEVER AT THIS TIME IT DOES NOT APPEAR AS
THROUGH CAUTIONARY LEVEL WINDS OF 15-20 KNOTS WILL BE REACHED FOR
THE MAJORITY OF THE FORECAST WATERS. WILL INCLUDE A MENTION OF
EXERCISE CAUTION FOR ONLY THE WATERS OFF CHARLOTTE AND LEE COUNTIES
WHERE THE BEST SETUP FOR THE NOCTURNAL WIND SURGE WILL EXIST. THIS
CONTINUED PATTERN OF ONSHORE AFTERNOON WINDS AND OFFSHORE SLIGHTLY
STRONGER FLOW AT NIGHT AND DURING THE EARLY MORNING HOURS WILL
CONTINUE THROUGH THE UPCOMING WEEKEND AS HIGH PRESSURE REMAINS
PARKED TO THE NORTH OF THE FORECAST WATERS.
&&
.FIRE WEATHER...
LOW LEVEL MOISTURE WILL INCREASE FURTHER INTO THE WEEKEND
PREVENTING RELATIVE HUMIDITY FROM REACHING CRITICAL LEVELS EITHER
SATURDAY OR SUNDAY. THERE WILL BE BETTER CHANCES FOR A FEW AFTERNOON
STORMS ALONG THE SEA-BREEZE THIS WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 73 89 73 89 / 0 10 0 20
FMY 72 91 71 91 / 0 10 10 20
GIF 70 90 71 91 / 0 30 20 20
SRQ 71 89 71 88 / 0 10 10 10
BKV 67 90 66 90 / 10 10 10 20
SPG 74 88 74 88 / 0 10 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WEATHER...MROCZKA
MID TERM/LONG TERM...JELSEMA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
605 PM EDT FRI MAY 9 2014
.SYNOPSIS...
HIGH PRESSURE RIDGING INTO THE FORECAST AREA FROM THE ATLANTIC
WILL WEAKEN SATURDAY AS A DISSIPATING FRONTAL SYSTEM MOVES INTO
THE AREA. HIGH PRESSURE REGAINS CONTROL FOR THE BEGINNING OF NEXT
WEEK. ANOTHER FRONT IS EXPECTED TO AFFECT THE REGION LATE NEXT
WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
HEADING INTO THIS EVENING...THE SURFACE RIDGE WILL CONTINUE TO
EXTEND INTO THE FORECAST AREA FROM THE ATLANTIC. SATELLITE TRENDS
SHOW CONSIDERABLE MID AND UPPER CLOUDINESS MOVING ACROSS THE
REGION EARLY THIS EVENING. A WEAK MID-LEVEL SHORTWAVE TROUGH...A
LITTLE LOW-LEVEL CONVERGENCE ASSOCIATED WITH A WEAK LEE-SIDE
TROUGH PLUS DAYTIME HEATING HAS PRODUCED A FEW LIGHT SHOWERS
ACROSS THE WRN MIDLANDS/NRN CSRA. MAIN AREA OF
SHOWERS/THUNDERSTORMS REMAIN WELL WEST OF THE AREA CLOSER TO THE
COLD FRONT ACROSS WESTERN NC INTO NRN GA. WILL CONTINUE WITH A
MENTION OF A SLIGHT CHANCE OF A SHOWER/ISO THUNDER THROUGH THE
EVENING HOURS.
OVERNIGHT...THE MODELS INDICATE AN INCREASE IN MOISTURE...BUT THE
DEEPER MOISTURE REMAINS WEST OF THE AREA. THERE MAY BE AN INCREASE
IN INSTABILITY ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH.
HOWEVER...MOISTURE SHOULD REMAIN LIMITED AND ANY CONVERGENCE
ASSOCIATED WITH A LEE-SIDE TROUGH SHOULD BE WEAK. THE SHOWER OR
THUNDERSTORM CHANCE IS LOW. THE NAM AND GFS MOS HAVE POPS LESS
THAN 20 PERCENT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
THE MODELS INDICATE MOISTURE SATURDAY ASSOCIATED WITH THE
REMNANTS OF A COLD FRONT. PRECIPITABLE WATER IS FORECAST TO
INCREASE TO AROUND 1.5 INCHES WITH WEAK LIFT AHEAD OF THE BROAD
UPPER-LEVEL TROUGH. THERE SHOULD ALSO BE LITTLE LOW-LEVEL
CONVERGENCE ASSOCIATED WITH A WEAK LEE-SIDE TROUGH. KEPT CHANCE
POPS SATURDAY. THE GUIDANCE CONSENSUS SUPPORTS POPS AROUND 30
PERCENT.
THUNDERSTORMS MAY LINGER SATURDAY EVENING ASSOCIATED WITH CONVERGENCE
INTO THE WEAK LEE-SIDE TROUGH AND BAND OF MOISTURE FROM THE
REMNANTS OF THE FRONT PLUS HEATING. THE MODELS ARE CONSISTENT
SHIFTING DIMINISHING MOISTURE EAST SATURDAY NIGHT WITH H5 HEIGHTS
BUILDING. THE MODELS SHOW THE RIDGE REMAINING DOMINATE THROUGH
SUNDAY NIGHT WITH LITTLE MOISTURE. THE NAM AND GFS MOS SUPPORT
POPS LESS THAN 20 PERCENT LATE SATURDAY NIGHT THROUGH SUNDAY
NIGHT. USED THE WARMER TEMPERATURE GUIDANCE BECAUSE OF RECENT
VERIFICATION...UPPER RIDGING...AND THE DRY ENVIRONMENTAL CONDITIONS.
THE LOW TEMPERATURE GUIDANCE WAS CLOSE.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
MODELS ARE IN RELATIVELY GOOD AGREEMENT EARLY IN THE PERIOD BUT
THEN BEGIN TO DIFFER LATER IN THE WEEK. THE GFS MOVES THE UPPER
LEVEL TROF AND SFC CDFNT OUT EARLIER WHILE THE ECMWF IS SLOWER BY
24HRS. AS A RESULT CHANCES OF RAIN AND TEMPS ARE DIFFERENT. HAVE
TAKEN AN AVERAGE OF THE MOS GUIDANCE FOR EACH MODEL DAYS 5 THRU 7.
MODELS DO KEEP IT DRY EARLY IN THE WEEK THEN THE NEXT CHANCE OF
PRECIP WILL BE LATE IN THE PERIOD WHICH IS WHERE THE TIMING ISSUES
COME IN. MAX TEMPERATURES WILL BE AROUND 90 MONDAY AND TUESDAY
WITH UPPER 80S WEDNESDAY COOLING INTO THE UPPER 70S TO LOWER 80S
THURSDAY AND FRIDAY. OVERNIGHT LOWS WILL BE IN THE 60S MONDAY
THROUGH THURSDAY AND IN THE 50S FRIDAY.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
HIGH-LEVEL CLOUDS WILL CONTINUE TO STREAM ACROSS THE TAF SITES
THROUGH THE PERIOD IN THE SOUTHWEST FLOW ALOFT. CONVERGENCE
ASSOCIATED WITH A WEAK LEE-SIDE TROUGH PLUS MID-LEVEL SHORTWAVE
TROUGH COULD HELP SUPPORT THUNDERSTORMS BUT THE CHANCE IS LOW
BECAUSE OF SHALLOW MOISTURE AND WEAK FORCING. THE HRRR INDICATES
JUST ISOLATED COVERAGE LATE THIS AFTERNOON AND THE CHANCE IS MUCH
TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME. MIXING
HAS RESULTED IN WIND GUSTS AROUND 20 KNOTS THIS AFTERNOON.
DIMINISHED MIXING BEGINNING AROUND SUNSET SHOULD RESULT IN LESS
WIND. CLOUDINESS AND A LITTLE MIXING SHOULD LIMIT FOG DURING THE
EARLY MORNING HOURS SATURDAY. THE GFS AND NAM MOS INDICATE VFR
CONDITIONS.
.EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
THROUGH TUESDAY.
&&
.CLIMATE...
TODAY MARKS THE 5TH DAY IN A ROW OF 90 DEGREES OR HIGHER AT BOTH
AUGUSTA BUSH FIELD AND COLUMBIA METRO. THIS IS NOT A RECORD. AT
AUGUSTA...THE RECORD FOR THE MONTH OF MAY IS 13 CONSECUTIVE DAYS
IN 1998 AND 1965. AT COLUMBIA...THE RECORD FOR THE MONTH OF MAY
IS 13 CONSECUTIVE DAYS IN 1962. TEMPERATURES ARE EXPECTED TO NOT
REACH 90 DEGREES SATURDAY WITH AFTERNOON HIGHS IN THE MID/UPPER
80S EXPECTED.
AGS...
5TH...92
6TH...91
7TH...91
8TH...91
9TH...90
CAE...
5TH...95 TIED THE RECORD HIGH OF 95 SET IN 2012 AND 1955
6TH...93
7TH...94
8TH...95
9TH...93
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
77
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
315 PM EDT FRI MAY 9 2014
SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
MOIST SW FLOW ALOFT HAS MOVED OVER THE FORECAST AREA WITH THE
DEEPEST MOISTURE OVER N AND PORTIONS OF CENTRAL GA WITH AN UPPER
SHORT WAVE IN THE FLOW. GFS AND NAM ARE INCONSISTENT WITH HOW FAR
SE TO TAKE THE DEEP MOISTURE WITH THE GFS MUCH MORE AGGRESSIVE
MOVING THE MOISTURE TO THE SE. HI-RES REFLECTIVITY FORECASTS FROM
THE WRF AND HRRR WEAKEN THE LINE OF SHOWERS AND STORMS OVER NW GA
EARLY THIS EVENING AND WITH ONLY WEAK INSTABILITY OVER N GA...THIS
SEEMS REASONABLE. THUNDERSTORM CHANCES EXPECTED TO DIMINISH FIRST
BUT THE SHOWER CHANCES MAY NOT BE FAR BEHIND. KEPT POPS IN THE
LIKELY CATEGORY OVER N GA ALL NIGHT AND THIS MAY BE OVERDONE. ALSO
AM HARD PRESSED TO INCLUDE POPS TOO FAR SE AS THE BEST MOISTURE AND
DYNAMICS DO NOT GET THAT FAR BUT ANY DEVELOPMENT WILL NEED TO BE
WATCHED THIS AFTERNOON AND OVERNIGHT.
GUIDANCE NOT BIG ON POPS SATURDAY INTO SATURDAY NIGHT WITH THE UPPER
FLOW BECOMING MORE ZONAL. WITH MOISTURE AND SOME INSTABILITY
EXPECTED...A FLAIR-UP OF SCATTERED SHOWERS AND THUNDERSTORMS SEEMS
REASONABLE FOR MUCH OF THE FORECAST AREA SATURDAY INTO SATURDAY
NIGHT.
FORECAST LOW TEMPERATURES RUNNING 5-8 DEGREES ABOVE NORMAL TONIGHT
AND SATURDAY NIGHT. FORECAST HIGH TEMPERATURES RUNNING 2-4 DEGREES
ABOVE NORMAL ON SATURDAY.
BDL
.LONG TERM /SUNDAY THROUGH FRIDAY/...
NOT MUCH CHANGE NEEDED AT THIS TIME TO THE FORECAST FOR THE
EXTENDED AS WE STILL LOOK FOR THE NEXT SIGNIFICANT SYSTEM TO
AFFECT THE AREA BY MID WEEK NEXT WEEK. THIS FAR OUT...CURRENT
GRIDS HAVE A GOOD HANDLE ON THIS AND NO CHANGES ARE PLANNED. FOR
THE INITIAL PORTION OF THE EXTENDED...PLAN TO INCREASE POPS THE
FIRST HALF OF SATURDAY NIGHT AS RESIDUAL CONVECTION LOOKS TO HANG
ON AFTER SUNSET.
DEESE
&&
.PREV DISCUSSION... /ISSUED 131 PM EDT FRI MAY 9 2014/
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
ECMWF AND GFS CONTINUE TO SHOW HIGH PRESSURE BUILDING FROM THE
EAST ON SUNDAY AND MONDAY AS A LONG-WAVE TROUGH DEEPENS OVER THE
WESTERN THIRD OF THE COUNTRY. DESPITE THE INCREASED RIDGING...
MODELS SHOW 800-1500 J/KG OF SBCAPE DURING MAX HEATING EACH DAY...
WARRANTING A SLIGHT CHANCE OF THUNDERSTORMS EACH AFTERNOON...
ESPECIALLY ACROSS NORTH GA WHERE OROGRAPHIC LIFT MAY ENHANCE
DEVELOPMENT. OTHERWISE... THE NEXT BEST CHANCE FOR WIDESPREAD
SHOWERS AND THUNDERSTORMS CONTINUES TO BE TUESDAY THROUGH POSSIBLY
EARLY THURSDAY AS THE AFOREMENTIONED LONG-WAVE TROUGH KICKS
EASTWARD AND DRAGS A COLD FRONT ACROSS THE STATE SOMETIME MID
WEEK. THERE IS SOME TIMING DIFFERENCES BETWEEN THE MODELS... WITH
THE FASTER GFS PUSHING THE COLD FRONT INTO NW GA TUESDAY NIGHT AND
CLEARING THE FORECAST AREA BY WEDNESDAY EVENING. THE SLOWER ECMWF
SHOWS THE FRONT ENTERING NW GA WEDNESDAY AFTERNOON...THEN CLEARING
THE FORECAST AREA SOMETIME THURSDAY MORNING. PREFERRING THE MORE
CONSISTENT GFS... WILL CONTINUE TO SHOW THE GREATER POPS AND
THUNDERSTORM CHANCES ON WEDNESDAY. HOWEVER... DID ADD A SLIGHT
CHANCE OF SHOWERS EARLY ON THURSDAY AS CLEARING MAY BE SLOW.
ALTHOUGH THE GREATER UPPER SUPPORT APPEARS TO LIFT ACROSS THE OHIO
VALLEY REGION... THIS SYSTEM STILL HAS A POTENTIAL TO PRODUCE A
FEW STRONG STORMS AHEAD OF THE FRONT... AS BOTH MODELS SHOW
800-1200 J/KG OF CAPE AHEAD OF THE FRONT BY WEDNESDAY AFTERNOON...
WITH THE FASTER GFS SUGGESTING CENTRAL GA WOULD HAVE THE GREATER
STORM THREAT... WHILE THE SLOWER ECMWF WOULD BE FOCUSED MORE ON
NORTH GA ON WEDNESDAY. WITH SUCH UNCERTAINTY ON TIMING AND
STRENGTH... ALL INTEREST ARE ENCOURAGED TO CLOSELY MONITOR LATER
FORECAST CONCERNING THIS SYSTEM.
39
AVIATION...
18Z UPDATE...
MOST VFR CONDITIONS WITH SOME MVFR CEILINGS. LOW CONFIDENCE FOR
CEILINGS...VSBYS AND WEATHER THROUGH THE PERIOD. THINKING IS MOST
SHOWERS AND STORMS WILL BE N AND W OF ATL INTO TONIGHT. SURFACE WINDS
SSW AROUND 10 KTS WITH OCCASIONAL GUSTS TO 20 KTS...DIMINISHING
EARLY EVENING.
//ATL CONFIDENCE...18Z UPDATE...
LOW CONFIDENCE CEILINGS...VSBYS AND WEATHER.
MEDIUM-HIGH CONFIDENCE WINDS.
BDL
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 64 83 61 86 / 20 50 40 20
ATLANTA 64 82 65 84 / 40 40 30 20
BLAIRSVILLE 59 75 58 80 / 60 60 40 20
CARTERSVILLE 62 82 61 86 / 60 40 40 20
COLUMBUS 65 85 65 88 / 20 40 20 20
GAINESVILLE 63 79 62 84 / 50 50 40 20
MACON 64 85 63 88 / 10 30 20 20
ROME 63 81 61 87 / 60 40 40 20
PEACHTREE CITY 62 83 61 85 / 30 40 20 20
VIDALIA 67 86 67 89 / 10 20 20 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BDL
LONG TERM....DEESE
AVIATION...BDL
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
243 PM EDT FRI MAY 9 2014
.SYNOPSIS...
HIGH PRESSURE RIDGING INTO THE FORECAST AREA FROM THE ATLANTIC
WILL WEAKEN SATURDAY AS A DISSIPATING FRONTAL SYSTEM MOVES INTO
THE AREA. HIGH PRESSURE REGAINS CONTROL FOR THE BEGINNING OF NEXT
WEEK. ANOTHER FRONT IS EXPECTED TO AFFECT THE REGION LATE NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...THE SURFACE RIDGE WILL CONTINUE TO EXTEND INTO THE
FORECAST AREA FROM THE ATLANTIC. THE LOWER LEVELS SHOULD REMAIN
RELATIVELY DRY. SATELLITE TRENDS SHOW CONSIDERABLE MID AND UPPER
CLOUDINESS MOVING INTO THE AREA IN THE SOUTHWEST FLOW AHEAD OF THE
TROUGH. A WEAK MID-LEVEL SHORTWAVE TROUGH...A LITTLE LOW-LEVEL
CONVERGENCE ASSOCIATED WITH A WEAK LEE-SIDE TROUGH PLUS HEATING
WILL HELP SUPPORT A FEW THUNDERSTORMS MAINLY IN THE WEST PART
CLOSER TO THE DEEPER MOISTURE. STILL...WITH JUST SHALLOW MOISTURE
AND WEAK FORCING IN THE FORECAST AREA BELIEVE COVERAGE WILL REMAIN
ISOLATED. THE LATEST HRRR INDICATES JUST ISOLATED SHOWERS OR THUNDERSTORMS.
TONIGHT...THE MODELS INDICATE AN INCREASE IN MOISTURE...BUT THE
DEEPER MOISTURE REMAINS WEST OF THE AREA. THERE MAY BE AN INCREASE
IN INSTABILITY ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH.
HOWEVER...MOISTURE SHOULD REMAIN LIMITED AND ANY CONVERGENCE
ASSOCIATED WITH A LEE-SIDE TROUGH SHOULD BE WEAK. THE SHOWER OR
THUNDERSTORM CHANCE IS LOW. THE NAM AND GFS MOS HAVE POPS LESS
THAN 20 PERCENT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
THE MODELS INDICATE MOISTURE SATURDAY ASSOCIATED WITH THE
REMNANTS OF A COLD FRONT. PRECIPITABLE WATER IS FORECAST TO
INCREASE TO AROUND 1.5 INCHES WITH WEAK LIFT AHEAD OF THE BROAD
UPPER-LEVEL TROUGH. THERE SHOULD ALSO BE LITTLE LOW-LEVEL
CONVERGENCE ASSOCIATED WITH A WEAK LEE-SIDE TROUGH. KEPT CHANCE
POPS SATURDAY. THE GUIDANCE CONSENSUS SUPPORTS POPS AROUND 30
PERCENT.
THUNDERSTORMS MAY LINGER SATURDAY EVENING ASSOCIATED WITH CONVERGENCE
INTO THE WEAK LEE-SIDE TROUGH AND BAND OF MOISTURE FROM THE
REMNANTS OF THE FRONT PLUS HEATING. THE MODELS ARE CONSISTENT
SHIFTING DIMINISHING MOISTURE EAST SATURDAY NIGHT WITH H5 HEIGHTS
BUILDING. THE MODELS SHOW THE RIDGE REMAINING DOMINATE THROUGH
SUNDAY NIGHT WITH LITTLE MOISTURE. THE NAM AND GFS MOS SUPPORT
POPS LESS THAN 20 PERCENT LATE SATURDAY NIGHT THROUGH SUNDAY
NIGHT. USED THE WARMER TEMPERATURE GUIDANCE BECAUSE OF RECENT
VERIFICATION...UPPER RIDGING...AND THE DRY ENVIRONMENTAL CONDITIONS.
THE LOW TEMPERATURE GUIDANCE WAS CLOSE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
MODELS ARE IN RELATIVELY GOOD AGREEMENT EARLY IN THE PERIOD BUT
THEN BEGIN TO DIFFER LATER IN THE WEEK. THE GFS MOVES THE UPPER
LEVEL TROF AND SFC CDFNT OUT EARLIER WHILE THE ECMWF IS SLOWER BY
24HRS. AS A RESULT CHANCES OF RAIN AND TEMPS ARE DIFFERENT. HAVE
TAKEN AN AVERAGE OF THE MOS GUIDANCE FOR EACH MODEL DAYS 5 THRU 7.
MODELS DO KEEP IT DRY EARLY IN THE WEEK THEN THE NEXT CHANCE OF
PRECIP WILL BE LATE IN THE PERIOD WHICH IS WHERE THE TIMING ISSUES
COME IN. MAX TEMPERATURES WILL BE AROUND 90 MONDAY AND TUESDAY
WITH UPPER 80S WEDNESDAY COOLING INTO THE UPPER 70S TO LOWER 80S
THURSDAY AND FRIDAY. OVERNIGHT LOWS WILL BE IN THE 60S MONDAY
THROUGH THURSDAY AND IN THE 50S FRIDAY.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
HIGH-LEVEL CLOUDS WILL CONTINUE TO STREAM ACROSS THE TAF SITES
THROUGH THE PERIOD IN THE SOUTHWEST FLOW ALOFT. CONVERGENCE
ASSOCIATED WITH A WEAK LEE-SIDE TROUGH PLUS MID-LEVEL SHORTWAVE
TROUGH COULD HELP SUPPORT THUNDERSTORMS BUT THE CHANCE IS LOW
BECAUSE OF SHALLOW MOISTURE AND WEAK FORCING. THE HRRR INDICATES
JUST ISOLATED COVERAGE LATE THIS AFTERNOON AND THE CHANCE IS MUCH
TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME. MIXING
HAS RESULTED IN WIND GUSTS AROUND 20 KNOTS THIS AFTERNOON.
DIMINISHED MIXING BEGINNING AROUND SUNSET SHOULD RESULT IN LESS
WIND. CLOUDINESS AND A LITTLE MIXING SHOULD LIMIT FOG DURING THE
EARLY MORNING HOURS SATURDAY. THE GFS AND NAM MOS INDICATE VFR
CONDITIONS.
.EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
200 PM EDT FRI MAY 9 2014
.SYNOPSIS...
HIGH PRESSURE RIDGING INTO THE FORECAST AREA FROM THE ATLANTIC
WILL WEAKEN SATURDAY AS A DISSIPATING FRONTAL SYSTEM MOVES INTO
THE AREA. HIGH PRESSURE REGAINS CONTROL FOR THE BEGINNING OF NEXT
WEEK. ANOTHER FRONT IS EXPECTED TO AFFECT THE REGION LATE NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...THE SURFACE RIDGE WILL CONTINUE TO EXTEND INTO THE
FORECAST AREA FROM THE ATLANTIC. THE LOWER LEVELS SHOULD REMAIN
RELATIVELY DRY. SATELLITE TRENDS SHOW CONSIDERABLE MID AND UPPER
CLOUDINESS MOVING INTO THE AREA IN THE SOUTHWEST FLOW AHEAD OF THE
TROUGH. A WEAK MID-LEVEL SHORTWAVE TROUGH...A LITTLE LOW-LEVEL
CONVERGENCE ASSOCIATED WITH A WEAK LEE-SIDE TROUGH PLUS HEATING
COULD POSSIBLY SUPPORT THUNDERSTORMS LATE...BUT THE CHANCE IS VERY
LOW BECAUSE OF SHALLOW MOISTURE AND WEAK FORCING. THE LATEST HRRR
INDICATES JUST ISOLATED SHOWERS LATE IN THE DAY. THE FORECAST
APPEARS ON TRACK WITH POPS LESS THAN 20 PERCENT. IT SHOULD BE A
LITTLE COOLER THAN PREVIOUS DAYS BECAUSE OF CLOUDINESS.
HOWEVER...IT WILL LIKELY NOT BE NOTICEABLE BECAUSE OF A SLIGHT
INCREASE IN HUMIDITY.
TONIGHT...THE MODELS INDICATE AN INCREASE IN MOISTURE...BUT THE
DEEPER MOISTURE REMAINS WEST OF THE AREA. THERE MAY BE AN INCREASE
IN INSTABILITY ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH.
HOWEVER...MOISTURE SHOULD REMAIN LIMITED AND ANY CONVERGENCE
ASSOCIATED WITH A LEE-SIDE TROUGH SHOULD BE WEAK. THE SHOWER OR
THUNDERSTORM CHANCE IS LOW. THE NAM AND GFS MOS HAVE POPS LESS
THAN 20 PERCENT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
THE MODELS INDICATE MOISTURE SATURDAY ASSOCIATED WITH THE
REMNANTS OF A COLD FRONT. PRECIPITABLE WATER IS FORECAST TO
INCREASE TO AROUND 1.5 INCHES WITH WEAK LIFT AHEAD OF THE BROAD
UPPER-LEVEL TROUGH. THERE SHOULD ALSO BE LITTLE LOW-LEVEL
CONVERGENCE ASSOCIATED WITH A WEAK LEE-SIDE TROUGH. KEPT CHANCE
POPS SATURDAY. THE GUIDANCE CONSENSUS SUPPORTS POPS AROUND 30
PERCENT.
THUNDERSTORMS MAY LINGER SATURDAY EVENING ASSOCIATED WITH CONVERGENCE
INTO THE WEAK LEE-SIDE TROUGH AND BAND OF MOISTURE FROM THE
REMNANTS OF THE FRONT PLUS HEATING. THE MODELS ARE CONSISTENT
SHIFTING DIMINISHING MOISTURE EAST SATURDAY NIGHT WITH H5 HEIGHTS
BUILDING. THE MODELS SHOW THE RIDGE REMAINING DOMINATE THROUGH
SUNDAY NIGHT WITH LITTLE MOISTURE. THE NAM AND GFS MOS SUPPORT
POPS LESS THAN 20 PERCENT LATE SATURDAY NIGHT THROUGH SUNDAY
NIGHT. USED THE WARMER TEMPERATURE GUIDANCE BECAUSE OF RECENT
VERIFICATION...UPPER RIDGING...AND THE DRY ENVIRONMENTAL CONDITIONS.
THE LOW TEMPERATURE GUIDANCE WAS CLOSE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
MODELS ARE IN RELATIVELY GOOD AGREEMENT EARLY IN THE PERIOD BUT
THEN BEGIN TO DIFFER LATER IN THE WEEK. THE GFS MOVES THE UPPER
LEVEL TROF AND SFC CDFNT OUT EARLIER WHILE THE ECMWF IS SLOWER BY
24HRS. AS A RESULT CHANCES OF RAIN AND TEMPS ARE DIFFERENT. HAVE
TAKEN AN AVERAGE OF THE MOS GUIDANCE FOR EACH MODEL DAYS 5 THRU 7.
MODELS DO KEEP IT DRY EARLY IN THE WEEK THEN THE NEXT CHANCE OF
PRECIP WILL BE LATE IN THE PERIOD WHICH IS WHERE THE TIMING ISSUES
COME IN. MAX TEMPERATURES WILL BE AROUND 90 MONDAY AND TUESDAY
WITH UPPER 80S WEDNESDAY COOLING INTO THE UPPER 70S TO LOWER 80S
THURSDAY AND FRIDAY. OVERNIGHT LOWS WILL BE IN THE 60S MONDAY
THROUGH THURSDAY AND IN THE 50S FRIDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
HIGH-LEVEL CLOUDS WILL CONTINUE TO STREAM ACROSS THE TAF SITES
THROUGH THE PERIOD IN THE SOUTHWEST FLOW ALOFT. CONVERGENCE
ASSOCIATED WITH A WEAK LEE-SIDE TROUGH PLUS MID-LEVEL SHORTWAVE
TROUGH COULD HELP SUPPORT THUNDERSTORMS BUT THE CHANCE IS VERY LOW
BECAUSE OF SHALLOW MOISTURE AND WEAK FORCING. THE HRRR INDICATES
JUST ISOLATED COVERAGE LATE THIS AFTERNOON AND THE CHANCE IS MUCH
TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME. THE
NAM BUFKIT MOMENTUM TRANSFER TOOL...GFS LAMP...AND KCAE 88D VAD
WIND PROFILE INDICATE WIND GUSTS 20 TO 25 KNOTS THIS AFTERNOON.
THE HIGH CLOUDINESS SHOULD LIMIT MIXING SOMEWHAT SO FORECASTED
GUSTS NEAR THE LOWER END OF THE RANGE. CLOUDINESS AND MIXING
SHOULD LIMIT FOG DURING THE EARLY MORNING HOURS SATURDAY. THE GFS
AND NAM MOS INDICATE VFR CONDITIONS.
.EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
105 PM EDT FRI MAY 9 2014
.SYNOPSIS...
HIGH PRESSURE RIDGING INTO THE FORECAST AREA FROM THE ATLANTIC
WILL WEAKEN SATURDAY AS A DISSIPATING FRONTAL SYSTEM MOVES INTO
THE AREA. HIGH PRESSURE REGAINS CONTROL FOR THE BEGINNING OF NEXT
WEEK. ANOTHER FRONT IS EXPECTED TO AFFECT THE REGION LATE NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...THE SURFACE RIDGE WILL CONTINUE TO EXTEND INTO THE
FORECAST AREA FROM THE ATLANTIC. THE LOWER LEVELS SHOULD REMAIN
RELATIVELY DRY. SATELLITE TRENDS SHOW CONSIDERABLE MID AND UPPER
CLOUDINESS MOVING INTO THE AREA IN THE SOUTHWEST FLOW AHEAD OF THE
TROUGH. A WEAK MID-LEVEL SHORTWAVE TROUGH...A LITTLE LOW- LEVEL
CONVERGENCE ASSOCIATED WITH A WEAK LEE-SIDE TROUGH PLUS HEATING
COULD POSSIBLY SUPPORT THUNDERSTORMS LATE...BUT THE CHANCE IS VERY
LOW BECAUSE OF SHALLOW MOISTURE AND WEAK FORCING. THE LATEST HRRR
INDICATES JUST ISOLATED SHOWERS LATE IN THE DAY. THE FORECAST
APPEARS ON TRACK WITH POPS LESS THAN 20 PERCENT. IT SHOULD BE A
LITTLE COOLER THAN PREVIOUS DAYS BECAUSE OF CLOUDINESS.
HOWEVER...IT WILL LIKELY NOT BE NOTICEABLE BECAUSE OF A SLIGHT
INCREASE IN HUMIDITY.
TONIGHT...THE MODELS INDICATE AN INCREASE IN MOISTURE...BUT THE
DEEPER MOISTURE REMAINS WEST OF THE AREA. THERE MAY BE AN INCREASE
IN INSTABILITY ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH.
HOWEVER...MOISTURE SHOULD REMAIN LIMITED AND ANY CONVERGENCE
ASSOCIATED WITH A LEE-SIDE TROUGH SHOULD BE WEAK. THE SHOWER OR
THUNDERSTORM CHANCE IS LOW. THE NAM AND GFS MOS HAVE POPS LESS
THAN 20 PERCENT.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
THE MODELS INDICATE AN INCREASE IN MOISTURE SATURDAY ASSOCIATED
WITH THE REMNANTS OF A COLD FRONT. PRECIPITABLE WATER IS FORECAST
TO INCREASE TO AROUND 1.5 INCHES WITH WEAK LIFT AHEAD OF THE BROAD
UPPER-LEVEL TROUGH. THERE SHOULD ALSO BE LITTLE LOW-LEVEL
CONVERGENCE ASSOCIATED WITH A WEAK LEE-SIDE TROUGH. KEPT CHANCE
POPS SATURDAY. THE GUIDANCE CONSENSUS SUPPORTS POPS AROUND 30 PERCENT.
THUNDERSTORMS MAY LINGER SATURDAY EVENING ASSOCIATED WITH CONVERGENCE
INTO THE WEAK LEE-SIDE TROUGH AND BAND OF MOISTURE FROM THE
REMNANTS OF THE FRONT PLUS HEATING. THE MODELS ARE CONSISTENT
SHIFTING DIMINISHING MOISTURE EAST SATURDAY NIGHT WITH H5 HEIGHTS
BUILDING. THE MODELS SHOW THE RIDGE REMAINING DOMINATE THROUGH
SUNDAY NIGHT WITH LITTLE MOISTURE. THE NAM AND GFS MOS SUPPORT
POPS LESS THAN 20 PERCENT LATE SATURDAY NIGHT THROUGH SUNDAY
NIGHT. USED THE WARMER TEMPERATURE GUIDANCE BECAUSE OF RECENT
VERIFICATION...UPPER RIDGING...AND THE DRY ENVIRONMENTAL CONDITIONS.
THE LOW TEMPERATURE GUIDANCE WAS CLOSE.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/... MODELS ARE IN RELATIVELY GOOD
AGREEMENT EARLY IN THE PERIOD BUT THEN BEGIN TO DIFFER LATER IN
THE WEEK. THE GFS MOVES THE UPPER LEVEL TROF AND SFC CDFNT OUT
EARLIER WHILE THE ECMWF IS SLOWER BY 24HRS. AS A RESULT CHANCES OF
RAIN AND TEMPS ARE DIFFERENT. HAVE TAKEN AN AVERAGE OF THE MOS
GUIDANCE FOR EACH MODEL DAYS 5 THRU 7. MODELS DO KEEP IT DRY EARLY
IN THE WEEK THEN THE NEXT CHANCE OF PRECIP WILL BE LATE IN THE
PERIOD WHICH IS WERE THE TIMING ISSUES COME IN. MAX TEMPERATURES
BE AROUND 90 MONDAY AND TUESDAY WITH UPPER 80S WEDNESDAY COOLING
INTO THE UPPER 70S TO LOWER 80S THURSDAY AND FRIDAY. OVERNIGHT
LOWS WILL BE IN THE 60S MONDAY THROUGH THURSDAY AND IN THE 50S
FRIDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
HIGH-LEVEL CLOUDS WILL CONTINUE TO STREAM ACROSS THE TAF SITES
THROUGH THE PERIOD IN THE SOUTHWEST FLOW ALOFT. CONVERGENCE
ASSOCIATED WITH A WEAK LEE-SIDE TROUGH PLUS MID-LEVEL SHORTWAVE
TROUGH COULD HELP SUPPORT THUNDERSTORMS BUT THE CHANCE IS VERY LOW
BECAUSE OF SHALLOW MOISTURE AND WEAK FORCING. THE HRRR INDICATES
JUST ISOLATED COVERAGE LATE THIS AFTERNOON AND THE CHANCE IS MUCH
TOO LOW TO INCLUDE IN THE TERMINAL FORECASTS AT THIS TIME. THE
NAM BUFKIT MOMENTUM TRANSFER TOOL...GFS LAMP...AND KCAE 88D VAD
WIND PROFILE INDICATE WIND GUSTS 20 TO 25 KNOTS THIS AFTERNOON.
THE HIGH CLOUDINESS SHOULD LIMIT MIXING SOMEWHAT SO FORECASTED
GUSTS NEAR THE LOWER END OF THE RANGE. CLOUDINESS AND MIXING
SHOULD LIMIT FOG DURING THE EARLY MORNING HOURS SATURDAY. THE GFS
AND NAM MOS INDICATE VFR OR MVFR CONDITIONS WITH MVFR FOG CONFINED
TO THE RIVER-VALLEY TERMINALS OF AGS AND OGB.
.EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
202 PM CDT FRI MAY 9 2014
.DISCUSSION...
1125 AM CDT
WE CONTINUE TO MONITOR SCATTERED CONVECTION MAINLY ALONG AND EAST
OF INTERSTATE 57 GOING INTO AFTERNOON WITH A SLIGHT RISK FOR
SEVERE STORMS. NO MAJOR CHANGES MADE TO AFTERNOON TEMPERATURES OR
STORM CHANCES...WITH SOME SUBTLE ADJUSTMENTS TO HOURLY TRENDS AND
SPATIAL COVERAGE.
MAIN SWATH OF MORNING PRECIPITATION ON THE LOW-LEVEL JET HAS
SHIFTED EAST OF THE AREA. THE SURFACE COLD FRONT AND ASSOCIATED
WESTERLY WIND SHIFT AND DRY ADVECTION IS LOCATED FROM NEAR
WAUKEGAN TO JUST WEST OF PONTIAC AS OF 1115 AM. SOME SCATTERING OF
CLOUDS IN ADVANCE OF THIS ALONG WITH CONTINUED WARM/MOIST
ADVECTION AHEAD OF THE FRONT HAS LED TO DESTABILIZATION AHEAD OF
THE FRONT WITHIN A MOISTURE-RICH WARM SECTOR. SCATTERED CONVECTION
FROM THE SOUTH CHICAGO METRO TO KANKAKEE LOOKS SUPPORTED BY
INCREASING LOW-LEVEL CONVERGENCE...WHICH SHOULD CONTINUE WITH THE
BOUNDARY ADVANCING THIS AFTERNOON. AN UPSTREAM SHORT WAVE IN
EASTERN MO AND BROADER FORCING FOR ASCENT WITH UPPER JET SUPPORT
WOULD FAVOR INCREASING SHEAR AND A POTENTIAL INTENSIFICATION IN
THE SCATTERED CONVECTION AFTER 1 PM OR SO...INCLUDING THE
POSSIBILITY OF A FEW SEVERE STORMS IN THE SOUTHEAST FORECAST AREA
CONCURRENT WITH THE SPC SLIGHT RISK.
EARLIER CONVECTION THIS MORNING HAD PRODUCED SOME 40-52 MPH GUSTS
ACROSS FAR NORTHWEST INDIANA AND ANY AFTERNOON CONVECTION COULD
ALSO BE SPORADICALLY GUSTY. COOLING MID-LEVEL TEMPS AND STRONGER
UPDRAFTS MAY SUPPORT SOME MARGINALLY SEVERE HAIL WITH THE
STRONGEST STORMS AS WELL.
MTF
//PREV DISCUSSION...
335 AM CDT
MULTIPLE FORECAST CONCERNS THIS GO AROUND INCLUDING PRECIP CHANCES
TODAY...CONVECTIVE POTENTIAL LATER IN THE WEEKEND...MAGNITUDE OF
WARM UP AHEAD OF SYSTEM LATER THIS WEEKEND/EARLY NEXT WEEK...AND
THEN TRANSITION TOWARD UNSEASONABLY COOL/UNSETTLED WEATHER NEXT
WEEK.
COLD FRONT IS APPROACHING THE MISSISSIPPI RIVER EARLY THIS MORNING
WITH SOUTHERLY WINDS PUMPING WARM AND RATHER HUMID AIR NORTH INTO
THE AREA. NUMEROUS SUBTLE SHORTWAVES CONTINUE MOVE NE ACROSS THE
REGION RESULTING IN WAVES OF SHOWERS/T-STORMS. ONE WAVE IS MOVING
EAST OF THE AREA AT 08Z...HOWEVER SHORT RANGE GUIDANCE HAS BEEN
PRETTY INSISTENT THAT ANOTHER SHORTWAVE OVER MISSOURI WILL RESULT IN
AN INCREASE IN PRECIP THE NEXT SEVERAL HOURS...MOVING INTO THE
SOUTHEAST HALF TO TWO THIRDS OF THE CWA EARLY THIS MORNING.
EXTENSIVE CIRRUS MAKES SEEING THIS WAVE ON GOES IMAGERY
IMPOSSIBLE...BUT RECENT UPTICK IN SHOWERS OVER MISSOURI LENDS SOME
CREDENCE TO THE MODEL GUIDANCE AND PLAN TO CARRY HIGH POPS FOR EARLY
THIS MORNING. INSTABILITY IS FAIRLY WEAK SO NOT EXPECTING MUCH MORE
THAN JUST AN ISOLATED THUNDERSTORM OR TWO WITH MAINLY JUST SHOWERS
EARLY THIS MORNING.
COLD FRONT WILL SWEEP ACROSS THE AREA LATER THIS MORNING INTO THE
AFTERNOON USHERING IN A MUCH DRIER AIR MASS...THOUGH THE COLDER AIR
LAGS SOME BEHIND THE FRONT. THE RESULT SHOULD BE BECOMING MOSTLY
SUNNY WITH DRY WESTERLY WINDS LIKELY ALLOWING TEMPS TO HEAT UP
NICELY WELL INTO THE 70S. THERE REMAINS A CHANCE THAT THE FRONT MAY
NOT HAVE CLEARED OUR SE COUNTIES BY THE TIME CONVECTION REDEVELOPS
THIS AFTERNOON...SO HAVE MAINTAINED SOME CHANCE POPS THIS AFTERNOON
FAR SOUTHEAST CWA. ONCE FRONT MOVES EAST CONVECTIVE THREAT ENDS SE
CWA THIS AFTERNOON WITH DRY AND MILD WEATHER EXPECTED TONIGHT INTO
SATURDAY. WHILE PRESSURE GRADIENT WILL SUPPORT WEST WINDS SATURDAY
AFTERNOON...AM CONCERNED THAT GRADIENT WILL BE WEAK ENOUGH TO ALLOW
A WEAK AFTERNOON LAKE BREEZE TO DEVELOP AND CAUSING TEMPS NEAR THE
LAKE TO FALL OFF SOME IN THE AFTERNOON.
ANOTHER FAIRLY STRONG SHORTWAVE IS PROGGED TO PASS TO OUR NORTHWEST
SATURDAY NIGHT WITH STRENGTHENING WARM AIR ADVECTION REGIME SETTING
THE STAGE FOR SHOWERS/THUNDERSTORMS TO DEVELOP AGAIN SATURDAY NIGHT.
WILL LIKELY SEE SOME BREAK IN THE CONVECTION SUNDAY...WITH MUCH OF
THE DAY POTENTIALLY ENDING UP DRY AND WARM AS WE END UP BETWEEN
SYSTEMS. SYNOPTIC WARM FRONT IS PROGGED TO BE NORTH OF THE
AREA...BUT POTENTIAL EXISTS FOR NOCTURNAL CONVECTION SAT NIGHT TO
AUGMENT THE FRONTAL POSITION AND THAT RAISES SOME UNCERTAINTIES WITH
REGARDS TO TEMPS...ESPECIALLY ALONG THE LAKE BREEZE PRONE LAKE SIDE
AREAS.
NEXT STRONG SHORTWAVE IS EXPECTED TO EMERGE OUT ONTO THE CENTRAL
PLAINS LATER SUNDAY WITH CYCLOGENESIS TO OUR WEST SUNDAY NIGHT
LIKELY TO RESULT IN A SHARPENING SECONDARY WARM FRONT DEVELOPING TO
OUR SOUTH. SHOWERS/THUNDERSTORMS LOOK TO BE A GOOD BET IN THE WAA
REGIME SUNDAY NIGHT WITH SUFFICIENT SHEAR/INSTABILITY LIKELY TO BE
PRESENT TO SUPPORT SOME SEVERE POTENTIAL SUNDAY NIGHT. WARM FRONT
LIKELY TO MAKE IT NORTH OF THE CWA MONDAY...BUT TIMING DIFFERENCES
DO EXISTS BETWEEN THE GFS AND ECMWF. LEANING TOWARD THE SLOWER
TIMING OF THE ECMWF/GEM WHICH WOULD SUPPORT ANOTHER VERY WARM AND
HUMID DAY MONDAY WITH MOSTLY DRY CONDITIONS BEFORE A STRONG COLD
FRONT ARRIVES MONDAY NIGHT WITH INCREASING THREAT OF
SHOWERS/THUNDERSTORMS. SYNOPTICALLY FAVORABLE PATTERN EXISTS FOR
POTENTIALLY RESPECTABLE SEVERE WEATHER EPISODE MONDAY WITH TIMING OF
THE SYSTEM DICTATING WHETHER THE GREATEST SEVERE THREAT WILL BE HERE
OR TO OUR WEST. TOO SOON TO SAY FOR SURE...BUT MONDAY AND MONDAY
NIGHT WARRANT CLOSE ATTENTION WITH LATER FORECASTS.
BIG COLD UPPER LOW/TROUGH WILL SET UP SHOP OVER THE AREA TUESDAY
THROUGH THURSDAY. VERY COLD AIR ALOFT WITH THIS UPPER LOW //-26C AT
500MB// SHOULD SUPPORT DIURNAL SCATTERED SHOWER AND POSSIBLY ISOLD
T-STORM DEVELOPMENT. WHILE MUCH OF THE TIME WILL BE DRY TUES-THURS
THERE COULD VERY WELL BE SOME SCTD (MAINLY DIURNAL) CONVECTION
AROUND EACH DAY WHICH NECESSITATES MAINTAINING CHANCE POPS.
UNSEASONABLY COOL TEMPERATURES ARE EXPECTED WITH HIGHS STRUGGLING TO
REACH 60 BY WED AND THURSDAY.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* WESTERLY WINDS GUSTING TO AROUND 30 KT AT TIMES THIS AFTERNOON.
* POSSIBLE LAKE BREEZE SATURDAY AFTERNOON SHIFTING WINDS EASTERLY.
//DISCUSSION...UPDATED 18Z...
STRONG LOW PRESSURE ACROSS LAKE SUPERIOR CONTINUES TO MOVE
NORTHEAST WITH AN EXTENDING COLD FRONT HAVING PASSED THE NORTHERN
ILLINOIS AIRPORTS. THIS HAS TURNED WINDS MORE WEST-NORTHWEST.
SCATTERING OF CLOUDS BEHIND THE FRONT SHOULD MOVE ACROSS ALL TAF
SITES THIS AFTERNOON. WITH MORE EFFICIENT MIXING IN THIS
REGION...GUSTS TO AROUND 30 KT HAVE BEEN OBSERVED AND SHOULD
CONTINUE THIS AFTERNOON. SCATTERED STORMS ALONG THE FRONT WILL
REMAIN SOUTH OF THE TAF SITES...ALTHOUGH COULD GRAZE ACROSS THE
SOUTHERN TRACON AREA EARLY THIS AFTERNOON. AS THE SURFACE RIDGE
PASSES OVER THE REGION LATE TONIGHT INTO EARLY SATURDAY
MORNING...WIND SPEEDS WILL DIMINISH. THIS WILL AT LEAST ALLOW A
LAKE BREEZE TO DEVELOP. AS SOUTHWEST WINDS KICK IN BEHIND THE
FRONT IT SHOULD SLOW THE SPREAD OF THE LAKE BREEZE TO ORD AND MDW.
THERE IS STILL ANTICIPATED A SYNOPTIC SHIFT TOWARD SOUTH OR
SOUTHEAST-EAST LATE IN THE DAY/EARLY IN THE EVE EVEN IF THE LAKE
BREEZE DOES NOT ARRIVE.
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH IN WINDS THROUGH SATURDAY MORNING.
* LOW ON WHETHER WINDS TURN EASTERLY DURING SATURDAY AFTERNOON.
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SHRA/TSRA POSSIBLE.
SUNDAY...PERIODS OF SHRA/TSRA POSSIBLE.
MONDAY...PERIODS OF SHRA/TSRA POSSIBLE.
TUESDAY THROUGH THURSDAY...CHANCE SHRA.
MTF/KJB
&&
.MARINE...
201 PM CDT
AS LOW PRESSURE AND AN ASSOCIATED COLD FRONT MOVE EAST NORTHEAST
ACROSS THE REGION...SOUTH TO SOUTHWEST WINDS PERSIST OVER THE
LAKE. A FAIRLY TIGHT PRESSURE GRADIENT IS ALLOWING FOR A 15 TO 25
KT WIND WITH OCCASIONAL GUSTS TO 30 KT ACROSS THE LAKE. ALTHOUGH
SPEEDS WILL DIMINISH ACROSS THE SOUTHERN HALF OF THE LAKE AND
ILLINOIS/INDIANA NEARSHORES THIS EVENING AND OVERNIGHT...SPEEDS
WILL STAY CLOSER TO THE 30 KT RANGE TONIGHT FOR THE NORTHERN HALF
OF THE LAKE WHERE A SURFACE TROUGH AND TIGHTER PRESSURE GRADIENT
WILL SWING THROUGH. EXPECT THE DIMINISHING TREND TO OCCUR OVER THE
NORTHERN HALF OF THE LAKE ON SATURDAY AS APPROACHING SURFACE RIDGE
OF HIGH PRESSURE PROVIDES MORE OF A RELAXED SURFACE PATTERN ACROSS
THE LAKE.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 7 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
1259 PM CDT Fri May 9 2014
.DISCUSSION...
ISSUED 926 AM CDT Fri May 9 2014
Overnight convection has lifted northeastward out of the area,
leaving behind only a few scattered showers along/east of the I-57
corridor this morning. Cold front is currently approaching the
Illinois River. Ahead of the boundary, southwesterly winds
continue with 14z/9am temps in the upper 60s/lower 70s. Meanwhile
behind the front, W/NW winds have dropped the temp into the upper
50s around Galesburg. Front will only make slow progress eastward
today, with additional convection likely developing ahead of it
during the afternoon hours. NAM and HRRR both suggest scattered
thunderstorms will develop in the instability axis along/south of
I-70 by mid to late afternoon. In the meantime, relatively stable
airmass in the wake of the earlier convection should keep things
quiet through early afternoon. Have updated the forecast to
significantly reduce POPs this morning. Will only mention isolated
to scattered showers east of the Illinois River through midday,
then will increase POPs to likely for showers/thunder across the
SE KILX CWA this afternoon.
Barnes
&&
.AVIATION...
ISSUED 1259 PM CDT Fri May 9 2014
VFR conditions will prevail through the entire 18z TAF period. A
cold front currently just east of I-55 will push slowly eastward
this afternoon, with scattered thunderstorms developing along and
ahead of it. 1730z visible satellite imagery shows a fine line of
enhanced CU well ahead of the front that could eventually develop
into a broken line of convection over the next hour or two. This
line is already east of all terminals except KCMI, so have opted to
leave thunder mention out of the forecast at all sites at this
time. Better focus for widespread convection will remain well
south toward the I-70 corridor. Diurnal cloud cover will dissipate
by this evening, with mostly clear skies expected overnight into
Saturday morning. Winds will initially be gusty from the W/SW this
afternoon, then will diminish to less than 10kt tonight.
Barnes
&&
.PREV DISCUSSION...
ISSUED 312 AM CDT Fri May 9 2014
SHORT TERM...Today through Sunday
Surface map at 06z indicated 999 mb low pressure near KMSP with a
cold front trailing south through central IA and MO then down into
central OK where a weaker 1007 mb low resided. South flow off the
Gulf continued to pump in low to mid 60s dewpoints to central/SE
IL. Aloft, W/V imagery showed a strong warm conveyor belt overhead
which has produced rounds of thunderstorms mainly over eastern IL
for the past few hours. Another shortwave just entering SW MO was
sparking new thunderstorm development and this is expected to
shift northeast across the area through mid-morning as the cold
front moves into the western CWA. Short range models including
HRRR and SPC 4km WRF suggest this activity will push east of the
area by 18z while the cold front gradually tracks ESE across the
CWA. It appears convective debris will clear out by early
afternoon allowing upper 70s temps and mid 60s dewpoints to set up
across the eastern CWA ahead of the front. This would suggest CAPE
values around 2k J/kg with 40 kts 0-6km bulk shear overhead.
Questions remain if new convection will fire along the front as
low level convergence becomes less favorable. Any storms that
develop could become severe with damaging wind gusts and hail
given low wet-bulb zero heights near 9k ft. Radar simulations show
most favored areas would be near or south of I-70 in a 21z-02z
window.
Any lingering activity will shift east of the region overnight as
brief surface ridging moves overhead. This to provide dry and
seasonably warm weather Saturday with highs in the upper 70s/lower
80s. The pattern turns active again Saturday night as warm
advection precip ahead of the next Plains low develops in MO then
lifts northeast across the CWA. Rising heights and another round
of southerly flow ahead of this low should send another strong
warm front north of the area Saturday night or Sunday with more
associated precip chances. With the front now expected north by
Sunday afternoon and with 850 mb temps rising into the mid teens
have boosted highs to the low/mid 80s. Mixed signals if the
warm sector will be dry/capped and as a result chance pops
continue through Sunday night.
LONG TERM...Monday through Thursday
00z model suite still has some major timing differences with a strong
cold frontal passage Monday evening/night. EC continues to be most
consistent and slowest solution. Depending on timing, severe
weather will be a threat given dynamics with this system. Trends
continue to show a major pattern change behind this cold front, as
a deep upper level trough sets up over the central U.S. This will
bring well below normal temps to the region as 850 mb readings are
shown in the low single digits Tue-Thu, suggesting highs mainly
in the 60s as lows in the 40s. With cold air and deep cyclonic
flow overhead, diurnal heating may lead to scattered instability
showers Tue-Thu.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1135 AM CDT FRI MAY 9 2014
.DISCUSSION...
1125 AM CDT
WE CONTINUE TO MONITOR SCATTERED CONVECTION MAINLY ALONG AND EAST
OF INTERSTATE 57 GOING INTO AFTERNOON WITH A SLIGHT RISK FOR
SEVERE STORMS. NO MAJOR CHANGES MADE TO AFTERNOON TEMPERATURES OR
STORM CHANCES...WITH SOME SUBTLE ADJUSTMENTS TO HOURLY TRENDS AND
SPATIAL COVERAGE.
MAIN SWATH OF MORNING PRECIPITATION ON THE LOW-LEVEL JET HAS
SHIFTED EAST OF THE AREA. THE SURFACE COLD FRONT AND ASSOCIATED
WESTERLY WIND SHIFT AND DRY ADVECTION IS LOCATED FROM NEAR
WAUKEGAN TO JUST WEST OF PONTIAC AS OF 1115 AM. SOME SCATTERING OF
CLOUDS IN ADVANCE OF THIS ALONG WITH CONTINUED WARM/MOIST
ADVECTION AHEAD OF THE FRONT HAS LED TO DESTABILIZATION AHEAD OF
THE FRONT WITHIN A MOISTURE-RICH WARM SECTOR. SCATTERED CONVECTION
FROM THE SOUTH CHICAGO METRO TO KANKAKEE LOOKS SUPPORTED BY
INCREASING LOW-LEVEL CONVERGENCE...WHICH SHOULD CONTINUE WITH THE
BOUNDARY ADVANCING THIS AFTERNOON. AN UPSTREAM SHORT WAVE IN
EASTERN MO AND BROADER FORCING FOR ASCENT WITH UPPER JET SUPPORT
WOULD FAVOR INCREASING SHEAR AND A POTENTIAL INTENSIFICATION IN
THE SCATTERED CONVECTION AFTER 1 PM OR SO...INCLUDING THE
POSSIBILITY OF A FEW SEVERE STORMS IN THE SOUTHEAST FORECAST AREA
CONCURRENT WITH THE SPC SLIGHT RISK.
EARLIER CONVECTION THIS MORNING HAD PRODUCED SOME 40-52 MPH GUSTS
ACROSS FAR NORTHWEST INDIANA AND ANY AFTERNOON CONVECTION COULD
ALSO BE SPORADICALLY GUSTY. COOLING MID-LEVEL TEMPS AND STRONGER
UPDRAFTS MAY SUPPORT SOME MARGINALLY SEVERE HAIL WITH THE
STRONGEST STORMS AS WELL.
MTF
&&
.PREV DISCUSSION...
335 AM CDT
MULTIPLE FORECAST CONCERNS THIS GO AROUND INCLUDING PRECIP CHANCES
TODAY...CONVECTIVE POTENTIAL LATER IN THE WEEKEND...MAGNITUDE OF
WARM UP AHEAD OF SYSTEM LATER THIS WEEKEND/EARLY NEXT WEEK...AND
THEN TRANSITION TOWARD UNSEASONABLY COOL/UNSETTLED WEATHER NEXT
WEEK.
COLD FRONT IS APPROACHING THE MISSISSIPPI RIVER EARLY THIS MORNING
WITH SOUTHERLY WINDS PUMPING WARM AND RATHER HUMID AIR NORTH INTO
THE AREA. NUMEROUS SUBTLE SHORTWAVES CONTINUE MOVE NE ACROSS THE
REGION RESULTING IN WAVES OF SHOWERS/T-STORMS. ONE WAVE IS MOVING
EAST OF THE AREA AT 08Z...HOWEVER SHORT RANGE GUIDANCE HAS BEEN
PRETTY INSISTENT THAT ANOTHER SHORTWAVE OVER MISSOURI WILL RESULT IN
AN INCREASE IN PRECIP THE NEXT SEVERAL HOURS...MOVING INTO THE
SOUTHEAST HALF TO TWO THIRDS OF THE CWA EARLY THIS MORNING.
EXTENSIVE CIRRUS MAKES SEEING THIS WAVE ON GOES IMAGERY
IMPOSSIBLE...BUT RECENT UPTICK IN SHOWERS OVER MISSOURI LENDS SOME
CREDENCE TO THE MODEL GUIDANCE AND PLAN TO CARRY HIGH POPS FOR EARLY
THIS MORNING. INSTABILITY IS FAIRLY WEAK SO NOT EXPECTING MUCH MORE
THAN JUST AN ISOLATED THUNDERSTORM OR TWO WITH MAINLY JUST SHOWERS
EARLY THIS MORNING.
COLD FRONT WILL SWEEP ACROSS THE AREA LATER THIS MORNING INTO THE
AFTERNOON USHERING IN A MUCH DRIER AIR MASS...THOUGH THE COLDER AIR
LAGS SOME BEHIND THE FRONT. THE RESULT SHOULD BE BECOMING MOSTLY
SUNNY WITH DRY WESTERLY WINDS LIKELY ALLOWING TEMPS TO HEAT UP
NICELY WELL INTO THE 70S. THERE REMAINS A CHANCE THAT THE FRONT MAY
NOT HAVE CLEARED OUR SE COUNTIES BY THE TIME CONVECTION REDEVELOPS
THIS AFTERNOON...SO HAVE MAINTAINED SOME CHANCE POPS THIS AFTERNOON
FAR SOUTHEAST CWA. ONCE FRONT MOVES EAST CONVECTIVE THREAT ENDS SE
CWA THIS AFTERNOON WITH DRY AND MILD WEATHER EXPECTED TONIGHT INTO
SATURDAY. WHILE PRESSURE GRADIENT WILL SUPPORT WEST WINDS SATURDAY
AFTERNOON...AM CONCERNED THAT GRADIENT WILL BE WEAK ENOUGH TO ALLOW
A WEAK AFTERNOON LAKE BREEZE TO DEVELOP AND CAUSING TEMPS NEAR THE
LAKE TO FALL OFF SOME IN THE AFTERNOON.
ANOTHER FAIRLY STRONG SHORTWAVE IS PROGGED TO PASS TO OUR NORTHWEST
SATURDAY NIGHT WITH STRENGTHENING WARM AIR ADVECTION REGIME SETTING
THE STAGE FOR SHOWERS/THUNDERSTORMS TO DEVELOP AGAIN SATURDAY NIGHT.
WILL LIKELY SEE SOME BREAK IN THE CONVECTION SUNDAY...WITH MUCH OF
THE DAY POTENTIALLY ENDING UP DRY AND WARM AS WE END UP BETWEEN
SYSTEMS. SYNOPTIC WARM FRONT IS PROGGED TO BE NORTH OF THE
AREA...BUT POTENTIAL EXISTS FOR NOCTURNAL CONVECTION SAT NIGHT TO
AUGMENT THE FRONTAL POSITION AND THAT RAISES SOME UNCERTAINTIES WITH
REGARDS TO TEMPS...ESPECIALLY ALONG THE LAKE BREEZE PRONE LAKE SIDE
AREAS.
NEXT STRONG SHORTWAVE IS EXPECTED TO EMERGE OUT ONTO THE CENTRAL
PLAINS LATER SUNDAY WITH CYCLOGENESIS TO OUR WEST SUNDAY NIGHT
LIKELY TO RESULT IN A SHARPENING SECONDARY WARM FRONT DEVELOPING TO
OUR SOUTH. SHOWERS/THUNDERSTORMS LOOK TO BE A GOOD BET IN THE WAA
REGIME SUNDAY NIGHT WITH SUFFICIENT SHEAR/INSTABILITY LIKELY TO BE
PRESENT TO SUPPORT SOME SEVERE POTENTIAL SUNDAY NIGHT. WARM FRONT
LIKELY TO MAKE IT NORTH OF THE CWA MONDAY...BUT TIMING DIFFERENCES
DO EXISTS BETWEEN THE GFS AND ECMWF. LEANING TOWARD THE SLOWER
TIMING OF THE ECMWF/GEM WHICH WOULD SUPPORT ANOTHER VERY WARM AND
HUMID DAY MONDAY WITH MOSTLY DRY CONDITIONS BEFORE A STRONG COLD
FRONT ARRIVES MONDAY NIGHT WITH INCREASING THREAT OF
SHOWERS/THUNDERSTORMS. SYNOPTICALLY FAVORABLE PATTERN EXISTS FOR
POTENTIALLY RESPECTABLE SEVERE WEATHER EPISODE MONDAY WITH TIMING OF
THE SYSTEM DICTATING WHETHER THE GREATEST SEVERE THREAT WILL BE HERE
OR TO OUR WEST. TOO SOON TO SAY FOR SURE...BUT MONDAY AND MONDAY
NIGHT WARRANT CLOSE ATTENTION WITH LATER FORECASTS.
BIG COLD UPPER LOW/TROUGH WILL SET UP SHOP OVER THE AREA TUESDAY
THROUGH THURSDAY. VERY COLD AIR ALOFT WITH THIS UPPER LOW //-26C AT
500MB// SHOULD SUPPORT DIURNAL SCATTERED SHOWER AND POSSIBLY ISOLD
T-STORM DEVELOPMENT. WHILE MUCH OF THE TIME WILL BE DRY TUES-THURS
THERE COULD VERY WELL BE SOME SCTD (MAINLY DIURNAL) CONVECTION
AROUND EACH DAY WHICH NECESSITATES MAINTAINING CHANCE POPS.
UNSEASONABLY COOL TEMPERATURES ARE EXPECTED WITH HIGHS STRUGGLING TO
REACH 60 BY WED AND THURSDAY.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* NEARBY SHRA TO MDW THROUGH 1730Z OR SO...WITH SCATTERED CONVECTION
IN THE SOUTHERN TRACON AREA.
* MVFR CIGS DISSIPATING BY EARLY THIS AFTERNOON.
* GUSTY SOUTHWESTERLY WINDS THIS AFTERNOON.
MTF/KJB
//DISCUSSION...UPDATED 16Z...
COLD FRONT IS MOVING EAST ACROSS NORTHERN IL ALTHOUGH SLOWING LATE
THIS MORNING. SCATTERED SHRA/TSRA ARE DEVELOPING AHEAD OF THIS
FROM JUST SOUTH OF MDW TO NEAR PNT. THESE ARE FAVORED TO
REGENERATE THROUGH MID AFTERNOON BEFORE PUSHING EAST. THESE ARE
HIGHLY LIKELY TO REMAIN SOUTH OF ORD BUT MDW IT MAY BE CLOSE FOR A
FEW HOURS.
//PREV DISCUSSION...UPDATED 12Z...
THE THREAT FOR THUNDERSTORMS IS QUICKLY ENDING ACROSS THE AREA.
HOWEVER...PERIODS OF SHOWERS WILL CONTINUE FOR A COUPLE MORE HOURS
THIS MORNING...BEFORE ENDING. THE INCREASE IN LOWER LEVEL MOISTURE
HAS ALSO LEAD TO SOME LOWER MVFR TO EVEN SOME IFR CIGS ACROSS
PORTIONS OF THE AREA THIS MORNING. THESE LOWER CIGS ARE EXPECTED
TO BE FAIRLY SHORT LIVED...WITH IMPROVEMENT TO VFR CONDITIONS
EXPECTED BY MID TO LATE MORNING.
THE WINDS WILL REMAIN GUSTY OUT OF THE SOUTH-SOUTHWEST...WITH GUSTS
LIKELY UP AROUND 25 KT THROUGH MUCH OF THE DAY. A COOL FRONT WILL
SHIFT ACROSS THE AREA BY LATE AFTERNOON/EARLY EVENING...WITH WINDS
EXPECTED TO BECOME MORE WESTERLY AND ABATE BY EVENING.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH THAT SHRA/TSRA WILL BE SOUTH OF MDW BY 19Z.
* HIGH WITH WIND TRENDS.
* MEDIUM WITH TIMING OF CIGS LIFTING TO VFR.
MTF/KJB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...SHRA/TSRA POSSIBLE.
SUNDAY...PERIODS OF SHRA/TSRA POSSIBLE.
MONDAY...PERIODS OF SHRA/TSRA POSSIBLE.
TUESDAY THROUGH THURSDAY...CHANCE SHRA.
KJB
&&
.MARINE...
223 AM CDT
LOW PRESSURE WILL SHIFT NORTHEASTWARD ACROSS THE LAKE SUPERIOR
TODAY. THIS WILL RESULT IN ANOTHER DAY OF GUSTY SOUTH-SOUTHWESTERLY
WINDS UP AROUND 25 KT ACROSS THE LAKE. A RIDGE OF HIGH PRESSURE WILL
BUILD EASTWARD FROM THE MIDWEST TO LAKE MICHIGAN BY SATURDAY...WITH
LIGHTER WINDS EXPECTED TO ACCOMPANY THIS RIDGE OF HIGH PRESSURE.
ANOTHER AREA OF LOW PRESSURE IS FORECAST TO LIFT NORTHEASTWARD
ACROSS THE UPPER MIDWEST EARLY NEXT WEEK...AND THIS LOOKS TO RESULT IN
ANOTHER ACTIVE PERIOD OF WEATHER OVER THE A LAKE INTO THE MIDDLE OF
NEXT WEEK. THIS COULD INCLUDE A PERIOD OF STRONGER SOUTHERLY WINDS
AND MORE SHOWERS AND THUNDERSTORMS.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 7 PM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
926 AM CDT Fri May 9 2014
.DISCUSSION...
ISSUED 926 AM CDT Fri May 9 2014
Overnight convection has lifted northeastward out of the area,
leaving behind only a few scattered showers along/east of the I-57
corridor this morning. Cold front is currently approaching the
Illinois River. Ahead of the boundary, southwesterly winds
continue with 14z/9am temps in the upper 60s/lower 70s. Meanwhile
behind the front, W/NW winds have dropped the temp into the upper
50s around Galesburg. Front will only make slow progress eastward
today, with additional convection likely developing ahead of it
during the afternoon hours. NAM and HRRR both suggest scattered
thunderstorms will develop in the instability axis along/south of
I-70 by mid to late afternoon. In the meantime, relatively stable
airmass in the wake of the earlier convection should keep things
quiet through early afternoon. Have updated the forecast to
significantly reduce POPs this morning. Will only mention isolated
to scattered showers east of the Illinois River through midday,
then will increase POPs to likely for showers/thunder across the
SE KILX CWA this afternoon.
Barnes
&&
.AVIATION...
ISSUED 656 AM CDT Fri May 9 2014
The slow moving cold front will finally push across the terminal
sites today. MVFR clouds between 1500-2500 FT will become more
widespread during the first 3 to 5 hours of the TAFs, as low
clouds develop near the front. A break in the rain should
eventually work its way from west to east behind the front. The
front should pass PIA to SPI by 16z, then reach CMI to DEC by 21z.
The MVFR cigs should gradually give way to VFR cigs behind the
front this afternoon. Storm redevelopment is expected later this
afternoon ahead of the front, but the majority of those storms
should be southeast of the TAF sites. DEC and CMI could get
clipped as the line of storms develops after 20z, so a VCTS was
left in the TAFS from 20z to 01z.
Surface winds will remain out of a southerly direction at 12 to
17 kts early this morning with gusts to 25kt or higher at times
in and near any thunderstorms. Winds will veer more into the
southwest and then west this afternoon with speeds in the 15 to 20 kt
range with gusts up to 30 kts possible, especially if we can get
some sunshine to break through. VFR conditions are expected across
the entire forecast area this evening thru 12z.
Shimon
&&
.PREV DISCUSSION...
ISSUED 312 AM CDT Fri May 9 2014
SHORT TERM...Today through Sunday
Surface map at 06z indicated 999 mb low pressure near KMSP with a
cold front trailing south through central IA and MO then down into
central OK where a weaker 1007 mb low resided. South flow off the
Gulf continued to pump in low to mid 60s dewpoints to central/SE
IL. Aloft, W/V imagery showed a strong warm conveyor belt overhead
which has produced rounds of thunderstorms mainly over eastern IL
for the past few hours. Another shortwave just entering SW MO was
sparking new thunderstorm development and this is expected to
shift northeast across the area through mid-morning as the cold
front moves into the western CWA. Short range models including
HRRR and SPC 4km WRF suggest this activity will push east of the
area by 18z while the cold front gradually tracks ESE across the
CWA. It appears convective debris will clear out by early
afternoon allowing upper 70s temps and mid 60s dewpoints to set up
across the eastern CWA ahead of the front. This would suggest CAPE
values around 2k J/kg with 40 kts 0-6km bulk shear overhead.
Questions remain if new convection will fire along the front as
low level convergence becomes less favorable. Any storms that
develop could become severe with damaging wind gusts and hail
given low wet-bulb zero heights near 9k ft. Radar simulations show
most favored areas would be near or south of I-70 in a 21z-02z
window.
Any lingering activity will shift east of the region overnight as
brief surface ridging moves overhead. This to provide dry and
seasonably warm weather Saturday with highs in the upper 70s/lower
80s. The pattern turns active again Saturday night as warm
advection precip ahead of the next Plains low develops in MO then
lifts northeast across the CWA. Rising heights and another round
of southerly flow ahead of this low should send another strong
warm front north of the area Saturday night or Sunday with more
associated precip chances. With the front now expected north by
Sunday afternoon and with 850 mb temps rising into the mid teens
have boosted highs to the low/mid 80s. Mixed signals if the
warm sector will be dry/capped and as a result chance pops
continue through Sunday night.
LONG TERM...Monday through Thursday
00z model suite still has some major timing differences with a strong
cold frontal passage Monday evening/night. EC continues to be most
consistent and slowest solution. Depending on timing, severe
weather will be a threat given dynamics with this system. Trends
continue to show a major pattern change behind this cold front, as
a deep upper level trough sets up over the central U.S. This will
bring well below normal temps to the region as 850 mb readings are
shown in the low single digits Tue-Thu, suggesting highs mainly
in the 60s as lows in the 40s. With cold air and deep cyclonic
flow overhead, diurnal heating may lead to scattered instability
showers Tue-Thu.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
136 PM EDT FRI MAY 9 2014
.SYNOPSIS...
ISSUED AT 358 AM EDT FRI MAY 9 2014
A LOW PRESSURE SYSTEM WILL MOVE NORTHEAST ACROSS THE UPPER GREAT
LAKES TODAY AND ACROSS ONTARIO TONIGHT. A COLD FRONT TRAILING
SOUTH FROM THE LOW WILL MOVE ACROSS OUR AREA THIS AFTERNOON AND
TONIGHT. OCCASIONAL SHOWERS AND THUNDERSTORMS ARE EXPECTED AHEAD
OF THE COLD FRONT TODAY WITH SCATTERED STORMS POSSIBLY LINGERING
INTO THIS EVENING. HIGHS TODAY WILL BE IN THE MID 70S WITH LOWS
TONIGHT RANGING FROM THE UPPER 40S OVER SOUTHWEST MICHIGAN AND
NORTHWEST INDIANA... TO THE UPPER 50S OVER NORTHWEST OHIO.
&&
.UPDATE...
ISSUED AT 1020 AM EDT FRI MAY 9 2014
LINE OF SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS CURRENTLY
APPROACHING THE AREA...ASSOCIATED WITH A WEAK VORT MAX JUST AHEAD OF
THE MAIN SURFACE COLD FRONT. SPC/RAP MESOANALYSIS SHOWS ALMOST NO
INSTABILITY ACROSS NORTHERN INDIANA...EXPLAINING THE LACK OF RECENT
LIGHTNING. EXPECT THIS WILL CONTINUE TO BE THE CASE THROUGH THE
MORNING WITH OVERCAST SKIES AND SOME LIGHT SHOWERS CONTINUING AHEAD
OF THE MAIN LINE. LATEST RAP13 AND HRRR SHOW ONLY A FEW HUNDRED J/KG
OF SBCAPE THROUGH THE EARLY AFTERNOON. SEVERE WEATHER POTENTIAL WITH
THIS ACTIVITY IS VERY LOW BUT A FEW WIND GUSTS AROUND 40MPH AND SOME
SMALL HAIL WILL BE POSSIBLE GIVEN 850MB WINDS OF 40-50 KNOTS AND
RELATIVELY COLD TEMPS ALOFT/LOW FREEZING LEVELS. HI-RES GUIDANCE
INDICATES THE POTENTIAL FOR A SLIGHT RECOVERY IN OUR WEST AND
SOUTHWEST COUNTIES LATER THIS AFTERNOON WITH MIDLEVEL DRY AIR BEHIND
THE INITIAL SHORTWAVE POSSIBLY ALLOWING FOR A FEW PEAKS OF
SUN...SIMILAR TO CURRENT VIS IMAGERY OVER ILLINOIS. WINDOW OF
OPPORTUNITY FOR SEVERE WEATHER WILL BE SMALL THOUGH AND FORECAST
SBCAPES ARE STILL ONLY AROUND 1000 J/KG...LIMITING UPDRAFT STRENGTH.
WILL BE DIFFICULT TO ADEQUATELY DESTABILIZE AFTER THIS MORNING RAIN.
ONCE AGAIN...STRAIGHT LINE WINDS AND SMALL HAIL WOULD BE THE MAIN
THREATS WITH THE BEST CHANCES PROBABLY IN THE 4-8PM TIMEFRAME BUT
THE SEVERE WEATHER THREAT REMAINS HIGHLY CONDITIONAL AT THIS POINT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM EDT FRI MAY 9 2014
UPR TROF OVER THE PLAINS WILL LIFT NE ACROSS THE GRTLKS AND
DEAMPLIFY TODAY-TNGT. LEAD SHRTWV WILL MOVE ACROSS OUR AREA THIS
MORNING ACCOMPANIED BY A LOW LEVEL THETA-E PLUME/WK INSTABILITY
RESULTING IN WIDESPREAD SHOWERS/TSTMS. MID LEVELS SHOULD DRY OUT IN
WAKE OF THIS LEAD WAVE THIS AFTN... ALLOWING FOR DECREASING
CLOUDINESS AND DESTABILIZATION AS LOW LEVELS REMAIN MOIST AHEAD OF
SFC CDFNT AND APCHG MAIN TROF. NAM SUGGESTS INSTABILITY WILL REACH
AROUND 1500J/KG OVER NRN INDIANA AND SRN MI THIS AFTN WITH 0-6KM
MAINLY UNIDIRECTIONAL SHEAR INCREASING TO AROUND 50KT. THOUGH
FORCING APPEARS FAIRLY WK THIS AFTN AS MOISTURE CONVERGENCE ALONG
CDFNT MINIMAL AND UPR TROF DEAMPLIFING... MODERATE INSTABILITY...
STRONG SHEAR... AND DRY MID LEVELS SUGGEST A POTENTIAL FOR SVR
TSTMS WITH DAMAGING WINDS AND LARGE HAIL... MAINLY ACROSS NRN
INDIANA IF DESTABILIZATION OCCURS AS FCST AND FORCING IS
SUFFICIENT FOR CONVECTION TO DEVELOP DURING PEAK HEATING. CURRENT
TEMPS NEAR PREVIOUS FCST HIGHS FOR TODAY... BUT TEMPS SHOULD RISE
LITTLE THIS MORNING WITH WIDESPREAD SHOWERS MOVG THROUGH AND
CONSIDERABLY COOLER ALOFT THAN YDAY... SO EXPECT HIGHS TODAY
GENERALLY IN THE M70S.
WKNG CDFNT WILL MOVE ACROSS THE AREA TONIGHT PRBLY ACCOMPANIED BY
SCT SHOWERS/TSTMS THIS EVE... WITH CONVECTION DIMINISHING AND MOVG
EAST OVERNIGHT. WK HIGH PRESSURE WILL BUILD INTO THE AREA OVERNIGHT
ALLOWING FOR CLEARING SKIES. SOME PATCHY FOG PSBL ACROSS WRN
PORTIONS OF THE AREA BUT HELD OFF ADDING AT THIS JUNCTURE. TEMPS
WILL BE CONSIDERABLY COOLER WITH LOWS RANGING FROM THE U40S NW TO
THE U50S SE.
&&
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 348 AM EDT FRI MAY 9 2014
LARGE SCALE SUBSIDENCE/DRYING WILL SUPPORT A DRY/COOLER SATURDAY AS
A WEAK AREA OF HIGH PRESSURE BUILDS IN BEHIND FRIDAY NIGHT`S FRONTAL
BOUNDARY. STRENGTHENING SOUTHWEST FLOW IN ADVANCE OF LONGWAVE TROUGH
AMPLIFICATION INTO THE WESTERN US SUNDAY AND HIGH PLAINS EARLY NEXT
WEEK WILL ALLOW GULF MOISTURE TO ADVECT WELL NORTH INTO THE GREAT
LAKES REGION DURING THIS TIME. LOW LEVEL THETA-E GRADIENT/WARM FRONT
IN ADVANCE OF THIS SYSTEM ON LLJ NOSE MAY BRING SOME MAINLY ELEVATED
CONVECTION TO THE AREA (FROM SW TO NE) LATER SATURDAY NIGHT THROUGH
SUNDAY NIGHT...WITH POPS KEPT IN THE LOW/MID CHC RANGE GIVEN THE
ABSENCE OF ANY WELL-DEFINED MID/UPPER LEVEL FORCING.
00Z GUIDANCE CONTINUED THE TREND TOWARD THE SLOWER ECMWF SOLUTION
REGARDING EASTWARD PROGRESSION OF THE UPPER TROUGH NEXT WEEK AS
SYSTEM EVENTUALLY PHASES WITH A CANADIAN PRAIRIES UPPER LOW. THIS
MAY LEAVE THE IWX CWA COMPLETELY IN THE WARM SECTOR BY MONDAY-MONDAY
NIGHT...ALTHOUGH CANNOT RULE OUT PCPN GIVEN MOIST AIRMASS/WEAK
CAPPING AND POTENTIAL FOR WEAK CONVECTIVELY ENHANCED/INDUCED
SHORTWAVES TO LIFT NORTHEAST INTO THE AREA WITHIN SOUTHWEST FLOW.
SHOWER/STORM CHANCES INCREASE AGAIN BY TUESDAY-TUESDAY NIGHT AS
HEIGHT FALLS OVERSPREAD PRE-FRONTAL TROUGH OR COLD FRONT. HELD CLOSE
TO PREV FCST (MID CHC POPS) BUT DID TREND TEMPS UP CLOSER TO WARMER
ECM/MEX MOS AND HPC GUIDANCE MONDAY-TUESDAY. COOLER WX RETURNS
WEDNESDAY INTO THURSDAY IN WAKE OF FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 136 PM EDT FRI MAY 9 2014
SURFACE COLD FRONT EXTENDING FROM LOW PRESSURE OVER THE NORTHERN
GREAT LAKES IS SLOWLY APPROACHING THE AREA. WEAK LOW LEVEL
CONVERGENCE IN A SUFFICIENTLY MOIST ENVIRONMENT IS SUPPORTING A
FEW SHOWERS ACROSS THE AREA. INSTABILITY HAS BEEN LIMITED BY
MORNING PRECIPITATION AND MOSTLY CLOUDY SKIES THOUGH.
THUNDERSTORMS WILL THEREFORE REMAIN ISOLATED THROUGH THE EVENING.
THERE IS STILL A CHANCE FOR A THUNDERSTORMS TO IMPACT EITHER KSBN
OR KFWA BUT THE PROBABILITY IS TOO LOW AND TIMING IS TOO UNCERTAIN
FOR INCLUSION IN THE TAF. PERIODS OF MVFR CEILINGS WILL BE
POSSIBLE UNTIL FRONT CLEARS THE AREA LATER TONIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR LMZ043-
046.
&&
$$
UPDATE...AGD
SYNOPSIS...JT
SHORT TERM...JT
LONG TERM...STEINWEDEL
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
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AREA FORECAST DISCUSSION
NWS DODGE CITY KS
401 PM CDT Fri May 9 2014
...Updated Longterm section...
.SHORT TERM...(This evening through Saturday)
ISSUED AT 313 PM CDT FRI MAY 9 2014
The upper level jet is progged to continue moving east this
afternoon with western Kansas coming under the left exit region of
upper jet this evening. Model soundings from the NAM and RUC13 show
fairly deep mixing with some small elevated CAPE developing along
the Colorado border by late this afternoon. The last few runs of the
HRRR have been consistent in showing isolated showers developing
along the Colorado border and moving into west central and southwest
Kansas for a few hours this evening. Will add this to the grids for
this evening.
As the weak shortwave moves over late tonight, another weak surge of
high pressure will push into southwest Kansas late tonight and early
Saturday. Overnight lows will drop into the mid 40s over west
central Kansas where dewpoints will be lower and winds could go
light for a few hours around sunrise. Low temperatures in south
central Kansas may only drop into the mid 50s where dewpoints are
higher.
During the day Saturday, mid level flow over the central Plains
gradually becomes southwesterly with time as an upper level
shortwave trough digs into the western states. This will result in
surface cyclogenesis over southeast Colorado during the afternoon.
Areas of southwest Kansas along the Oklahoma border should see high
temperatures rising into the upper 80s to near 90 degrees with
southerly winds increasing during the day. This could result in
critical fire weather conditions over far southwest Kansas in the
afternoon.
.LONG TERM...(Saturday night through Friday)
ISSUED AT 349 PM CDT FRI MAY 9 2014
The first issue during this period will be Saturday night. Rich
gulf moisture is not too far southeast, meaning it`s as close as
extreme southeast Oklahoma and north Texas. With the vigorous jet
and upper level anomaly digging into the Rockies, the surface
response will be rapidly falling pressure in the lee of the
Rockies. The surface low should deepen in southeast Colorado.
Boundary layer winds will become east to southeast and the
aforementioned rich moisture will begin stream northwest towards
my forecast area. Warm frontogenesis will take place and this will
advance rapidly north by Saturday night. I see a small opportunity
of elevated and nocturnal convection developing along the nose of
the moisture surge across my far southeast area after dark
Saturday night. Confidence is not high though.
Sunday will be the "warm" day in advance of a strong surge of cold
air that will be sweeping into the plains as the digging system
into the Rockies lifts out into the plains. There should be a
rather tight gradient of temperatures across my area and will
adjust the grids accordingly. With the rich gulf moisture, strong
uvv and surface convergence along the front the chance for
thunderstorms will be high late Sunday and Sunday evening. Behind
the front there should be continued lift and with strong cold air advection there
should be low stratus and at least drizzle, if not light rain.
Monday should be a rather raw day with clouds, blustery winds and
some precipitation. My forecast highs may be a little optimistic
but the trend is to definitely cooler temperatures.
Beyond Monday, the flow will be northwest flow aloft with perhaps
another minor wave sliding southeast which might promote showers
about mid week. Overall temperatures will be below normal seasonal
normals.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1220 PM CDT FRI MAY 9 2014
VFR conditions will prevail through this TAF period as high level
moisture will bring a scattered to broken cirrus clouds over the
central High Plains this afternoon and tonight. Southerly winds at
10 to 15 knots this afternoon will diminish tonight and become
light and variable.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 48 85 57 81 / 0 0 10 20
GCK 46 83 51 77 / 10 0 10 10
EHA 47 88 47 78 / 10 0 0 10
LBL 48 89 52 82 / 10 0 10 10
HYS 47 82 56 77 / 0 0 10 10
P28 54 89 68 91 / 0 10 20 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Gerard
LONG TERM...Hutton
AVIATION...Gerard
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
314 PM CDT Fri May 9 2014
...Updated synopsis and short term discussion...
.SYNOPSIS...
ISSUED AT 313 PM CDT FRI MAY 9 2014
This mornings upper air analysis showed a shortwave trough moving
east through the upper Midwest while another shortwave was moving
into the Big Bend region of Texas with more subtle shortwave energy
moving through the central Rockies. Higher up, a 300 millibar jet
was nosing into the Intermountain West. At the surface, a weak low
pressure trough extended south along the eastern slopes of the
Rockies.
&&
.SHORT TERM...(This evening through Saturday)
ISSUED AT 313 PM CDT FRI MAY 9 2014
The upper level jet is progged to continue moving east this
afternoon with western Kansas coming under the left exit region of
upper jet this evening. Model soundings from the NAM and RUC13 show
fairly deep mixing with some small elevated CAPE developing along
the Colorado border by late this afternoon. The last few runs of the
HRRR have been consistent in showing isolated showers developing
along the Colorado border and moving into west central and southwest
Kansas for a few hours this evening. Will add this to the grids for
this evening.
As the weak shortwave moves over late tonight, another weak surge of
high pressure will push into southwest Kansas late tonight and early
Saturday. Overnight lows will drop into the mid 40s over west
central Kansas where dewpoints will be lower and winds could go
light for a few hours around sunrise. Low temperatures in south
central Kansas may only drop into the mid 50s where dewpoints are
higher.
During the day Saturday, mid level flow over the central Plains
gradually becomes southwesterly with time as an upper level
shortwave trough digs into the western states. This will result in
surface cyclogenesis over southeast Colorado during the afternoon.
Areas of southwest Kansas along the Oklahoma border should see high
temperatures rising into the upper 80s to near 90 degrees with
southerly winds increasing during the day. This could result in
critical fire weather conditions over far southwest Kansas in the
afternoon.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 221 AM CDT FRI MAY 9 2014
Models this morning remain in decent agreement with moving an
upper low, which was located off the coast of British Columbia
near 140W at 00z Friday, into the four corners region by early
Sunday. As this next system moves into the southwest United States
early this weekend a trough of low pressure at the surface will
deepen along the lee of the Rockies and temperatures in the 850mb
to 700mb layer will warm. Given the mixing potential suggested by
the latest model soundings, and the 850mb to 700mb temperatures at
00z Sunday the previous forecast still looks on track with highs
in the 80s despite a cold front moving into southwest Kansas late
Saturday. Precipitation chance still appear to be more favorable
north of the interstate 70 corridor given the warm mid level
temperatures forecast over southwestern Kansas Saturday afternoon,
frontal boundary location, where the better forcing from the 850mb
warm air advection, and upper level jet dynamics will be located.
Precipitation chances will increase across western Kansas late
this weekend as the upper level low/trough approaches the Central
High Plains and the elevated mix layer begins to move east. By
Sunday night 850mb to 700mb moisture and frontogenesis will begin
to improve across far western Kansas/eastern Colorado as difluent
flow improves across eastern Colorado and western Kansas near the
nose of an upper level jet that will be ejecting from the base of
the upper level trough. As precipitation chances improves to our
west/northwest...scattered late day convection will be possible
across south central Kansas. This area will be along and east of a
dryline where afternoon CAPE values increase to greater than 2000
j/kg. 0-6km shear and instability suggests severe thunderstorms
will be possible in this area late day. Will therefore include a
mention in the HWO concerning severe potential in south central
Kansas late Sunday.
Afternoon thunderstorms in south central Kansas are forecast to
move east during the evening and the area of thunderstorms
associated with the mid level baroclinic zone begins to spread
into north central and portion of southwest Kansas. Will continue
to favor the higher chances of precipitation Sunday night as this
mid level baroclinic zone spreads east across the western Kansas.
Precipitation chances will taper off as the mid level baroclinic
zone moves east into central Kansas late Monday, however a few
isolated/widely scattered showers/thunderstorms still looks
possible through late day across north central and portions of
west central Kansas given the mid level lapse rates under the
500mb thermal trough. Based on expected cloud cover and 850mb
temperature trends will stay close to the previous forecast for
highs on Monday which were slightly cooler than the latest
guidance.
Monday night into Tuesday as surface high will cross western
Kansas. Based on decreasing wind and clear skies will continue to
favor temperatures cooler guidance for lows Monday night. Tuesday
will be warmer than Monday based on the 850mb temperatures at 00z
Wednesday. Highs on Tuesday will are currently expected to range
from the mid 60s to around 70 degrees.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1220 PM CDT FRI MAY 9 2014
VFR conditions will prevail through this TAF period as high level
moisture will bring a scattered to broken cirrus clouds over the
central High Plains this afternoon and tonight. Southerly winds at
10 to 15 knots this afternoon will diminish tonight and become
light and variable.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 48 82 55 81 / 0 0 10 10
GCK 47 81 50 72 / 0 0 10 10
EHA 50 85 50 77 / 0 0 0 10
LBL 48 86 52 80 / 0 0 10 10
HYS 48 80 52 69 / 0 0 10 20
P28 53 86 61 88 / 0 10 10 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Gerard
SHORT TERM...Gerard
LONG TERM...Burgert
AVIATION...Gerard
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1116 AM MDT FRI MAY 9 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 258 AM MDT FRI MAY 9 2014
EARLY MORNING WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOWS
CONFLUENT FLOW ENTERING ROCKIES OVER PLAINS ON BACK SIDE OF
DEPARTING TROUGH...WITH WEAK SHORTWAVE ENERGY UPSTREAM NEAR DIFLUENT
FLOW OVER GREAT BASIN. AT THE SURFACE HIGH PRESSURE IS IN PLACE OVER
OUR CWA WITH STATIONARY FRONT ALONG FRONT RANGING AND COLD FRONT OVER
OK/TX PANHANDLES. RADAR SHOWS SOME VIRGA AND VERY LIGHT SPRINKLES
LINGERING AS A SHORTWAVE IS EJECTING ACROSS THE SOUTHERLY PLAINS.
WITH SUBSIDENCE BUILDING IN FROM THE NORTH THIS ACTIVITY LIKELY WONT
LAST LONG. TEMPS HAVE DROPPED INTO THE MID 30S ACROSS THE WEST...AND
WE COULD SEE A FEW LOW TEMPS AROUND FREEZING BY SUNRISE.
A WEAK SHORTWAVE TROUGH WILL PASS NORTH OF THE CWA THIS AFTERNOON
AND EVENING AND MAY COMBINE WITH AFTERNOON/EVENING INSTABILITY TO
PRODUCE A FEW THUNDERSTORMS OVER NE COLORADO. VERY DRY LOW LEVELS
WOULD LIMIT PRECIP REACHING THE SURFACE. DECIDED TO KEEP SMALL AREA
OF OUR NW CWA WITH ISO THUNDER AROUND 00Z AND OTHERWISE LIMITED
PRECIP MENTION TO SPRINKLES. SEASONAL TEMPS SHOULD RETURN AS SOUTHERLY
FLOW REDEVELOPS TODAY...WITH HIGHS IN THE 70S AND OVERNIGHT LOWS
TONIGHT IN THE LOW-MID 40S (MAYBE A FEW SPOTS A LITTLE COLDER WEST).
SATURDAY-SUNDAY NIGHT...COMPLICATED FORECAST AS THE NEXT STRONG
UPPER TROUGH IS EXPECTED TO IMPACT THE CENTRAL ROCKIES AND PLAINS.
SOUTHWESTERLY FLOW DEVELOPS ACROSS THE ROCKIES WHICH WOULD
INITIALLY LIMIT ANY SHOWER/THUNDERSTORM CHANCES TO THE NW
SATURDAY. HOWEVER BY SATURDAY NIGHT THE MAIN TROUGH BEGINS TO SLIDE
EAST ALLOWING GOOD MOISTURE AND LIFT OT BUILD OVER THE CWA. BEST
PRECIP CHANCES ACROSS THE CWA STILL LOOKS TO BE ON SUN/SUN NIGHT AND
MODELS SHOW REASONABLE AGREEMENT ON MEASURABLE PRECIP SO I BUMP
POPS INTO 60-70 RANGE FOR THOSE PERIODS. A LITTLE LESS CONFIDENT ON
AREA OF BEST PRECIP...THOUGH PARTS OF THE REGION (ESPECIALLY WEST)
COULD SEE DECENT LIQUID ACCUMULATION WITH THIS EVENT (0.15-0.75").
REGARDING WEATHER TYPE...VERY LIMITED INSTABILITY THROUGH MOST OF THE
EVENT...SO ONLY KEPT THUNDER MENTION SATURDAY AFTERNOON/EVENING.
TEMP PROFILES AND WBZ HEIGHTS WOULD INDICATE A RAIN/SNOW MIX OR A
COMPLETE CHANGEOVER ACROSS THE WESTERN HALF OF THE CWA SUNDAY NIGHT.
WARM GROUND TEMPS MAY LIMIT ANY SNOW ACCUMULATION (ASSUMING LIGHTER
RATES). IN ADDITION TO WARM GROUND TEMPS...CONFIDENCE OF CHANGEOVER
TIMING IS LOW SO I LEFT ACCUMULATION MENTION OUT OF FORECAST. I DID
INCLUDE RAIN/SNOW MENTION AND A BRIEF PERIOD OF ALL SNOW AROUND
SUNRISE EARLY MONDAY MORNING. WILL NEED TO WATCH HOW THIS SYSTEM
EVOLVES TO ZERO IN ON THESE DETAILS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 258 AM MDT FRI MAY 9 2014
MODELS ARE STILL IN DISAGREEMENT WITH THE POSITION AND PROGRESSION
OF THE UPPER LEVEL TROUGH IN THE EXTENDED. GFS STILL MOVES IT
FURTHER EAST MORE QUICKLY THAN THE ECMWF. HOWEVER...THE TROUGH WILL
CONTINUE TO INFLUENCE THE CWA ON MONDAY. TEMPERATURES MONDAY MORNING
APPEAR COLD ENOUGH FOR LIGHT SNOW TO CONTINUE OVER EASTERN COLORADO
WITH A RAIN SNOW MIX IN NORTHWEST KANSAS IN COUNTIES BORDERING
EASTERN COLORADO. TEMPERATURES SHOULD WARM ENOUGH BY 15Z FOR ALL
PRECIPITATION TO BE RAIN...WITH THE CHANCE FOR RAIN CONTINUING
MONDAY AFTERNOON. MONDAY WILL REMAIN BREEZY AS THE TIGHT PRESSURE
GRADIENT STAYS OVER THE CWA UNTIL MONDAY NIGHT WHEN IT RELAXES AND
SURFACE HIGH PRESSURE SETTLES IN OVER COLORADO. TUESDAY THROUGH
WEDNESDAY SHOULD REMAIN DRY AS THE UPPER LEVEL RIDGE OVER THE
WESTERN UNITED STATES BECOMES MORE INFLUENTIAL IN THE HIGH PLAINS.
BY THURSDAY...A SHORTWAVE TROUGH WILL ROTATE AROUND THE UPPER TROUGH
OVER THE GREAT LAKES REGION SENDING A WEAK COLD FRONT THROUGH THE
CWA. SHOWERS AND THUNDERSTORMS COULD DEVELOP AHEAD OF THE
FRONT...SINCE THE GFS DOES HAVE A FEW HUNDRED J/KG OF CAPE OVER
EASTERN COLORADO. AS PREVIOUSLY MENTIONED...THE MODELS ARE HAVING A
HARD TIME COMING TO A CONSENSUS FOR ANY DAY IN THE EXTENDED...SO AM
TRYING TO GET AWAY FROM GETTING TOO DETAILED FOR THUNDERSTORM
POTENTIAL IN DAY 7.
WELL BELOW AVERAGE TEMPERATURES CAN BE EXPECTED TO START OFF THE
EXTENDED PERIOD WITH HIGHS ON MONDAY IN THE LOW TO UPPER 50S. LOWS
MONDAY NIGHT WILL BE IN THE LOW 30S TO LOW 40S WITH HIGHS ON TUESDAY
IN THE LOW TO MID 60S. SLIGHTLY BELOW TO NEAR NORMAL TEMPERATURES
WILL TAKE OVER THROUGH THE REST OF THE EXTENDED WITH HIGHS IN THE
MID 60S TO LOW 70S ON WEDNESDAY AND THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1112 AM MDT FRI MAY 9 2014
VFR EXPECTED THROUGH THE PERIOD AT BOTH KGLD AND KMCK. A FEW
SCATTERED HIGH BASED CU WILL FORM THROUGH THE AFTERNOON AS
CONVECTIVE TEMPERATURES ARE REACHED. HOWEVER SUB CLOUD LAYERS ARE
BONE DRY AND END RESULT WILL ONLY BE VIRGA OR A FEW
SPRINKLES...DISSIPATING AFTER SUNSET. OTHERWISE...A COLD FRONTAL
PASSAGE AROUND SUNRISE SATURDAY MORNING WILL SHIFT SURFACE WINDS
TO NORTHWEST AND THEY WILL BE BREEZY THROUGH SATURDAY MORNING.
&&
.FIRE WEATHER...
ISSUED AT 243 AM MDT FRI MAY 9 2014
WITH WARMER TEMPS AND LOWER TD MIXING TO THE SURFACE WE COULD SEE
RH VALUES WITHIN RFW CRITERIA ACROSS THE SOUTHERN PART OF OUR
FORECAST AREA BOTH TODAY AND SATURDAY AFTERNOON/EARLY EVENING
PERIODS. TODAY WINDS WILL BE WELL BELOW CRITERIA WITH WEAK
GRADIENT IN PLACE...SO NO RFW PRODUCT ANTICIPATED. SW PRESSURE
GRADIENT BEGINS TO INCREASE SATURDAY AHEAD OF DEEPENING UPPER
LOW...THOUGH EVOLUTION OF SURFACE LOW AND FRONT POSITION WILL BE
CRITICAL FOR WHERE WINDS WITHIN RFW CRITERIA WILL CROSS WITH LOW
RH. NOT ENOUGH CONFIDENCE AT THIS POINT TO ISSUE A FIRE WEATHER
WATCH FOR SATURDAY...BUT WE WILL PROBABLY NEED TO MONITOR.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...ALW
AVIATION...024
FIRE WEATHER...DR
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
514 PM EDT Fri May 9 2014
...Updated Aviation Discussion...
.SHORT TERM (Now through Saturday Night)...
Issued at 305 PM EDT Fri May 9 2014
In the near term, rainfall from this morning continues to move NE
but is still hanging in there over east-central KY. The rain will
exit our forecast area in the next 1-2 hrs. Otherwise, conditions
are dry with ample cloud cover over the rest of the region, with
some cumulus clouds now starting to emerge with modest diurnal
warming and decent low-level moisture. Nevertheless, the atmosphere
remains relatively stable at this time, as evidenced by current SPC
mesoanalysis. Thus, expect mainly rain free weather for the next few
hours over central KY and south-central IN as temperatures top out
thru the 70s to around 80 west.
Meanwhile, convection continues to slowly develop along and ahead of
a low-level frontal boundary and confluent zone from southwest IL
into south-central MO. Latest SPC mesoanalysis shows an axis of -4
to -6 surface-based LI values and around 1000 J/kg CAPE in this
axis. All short-range models and the latest HRRR and SPC SREF
suggest this convection will continue to develop and expand E-NE
late this afternoon and evening. Model soundings in our area show
lapse rates increasing late this afternoon and evening, especially
aloft resulting in a more conducive environment in time to develop
and maintain convection within. As a result, will ramp up POPs this
evening, first over south-central IN and northwest KY, then eastward
later tonight.
The best chances for severe storms are to our west in the area of
the current SPC severe thunderstorm watch, enhanced by good
instability and deep-layer speed shear (with a strong upper jet
advancing eastward). As the storms move east later tonight, they may
have a tendency to become slightly elevated with modest nocturnal
cooling over our area. Nevertheless, the boundary layer may stay
adequately mixed to allow some downward momentum transport from the
strongest cells to produce isolated strong or damaging winds, mainly
along and west of the I-65 corridor. After the storms move through,
can`t totally rule out additional scattered showers and isolated
thunderstorms well after midnight and into Saturday morning as a
mid-level shortwave approaches.
During the day Saturday, the shortwave will pass through our area.
This could continue the chance for scattered showers and storms over
eastern and southern forecast area in the morning, but should
effectively clear things out later in the day. As a result, much of
the afternoon should be precipitation free with temperatures rising
through the 70s. If enough sunshine occurs in the afternoon, could
see around 80 or lower 80s in western half of forecast area.
Air mass will begin to destabilize again Saturday afternoon in the
wake of the morning showers, but forcing should be quite limited
in the wake of the morning shortwave. Therefore, expect only
isolated cell redevelopment by late afternoon mainly over western
and northern areas of forecast area. This activity could become a
little more prevalent, especially northern half of forecast area,
Saturday night if a model weak signal of another approaching
shortwave proves correct.
.LONG TERM (Sunday through Friday)...
Issued at 250 PM EDT Fri May 9 2014
The long term period will be fairly active with multiple chances for
showers and thunderstorms. In addition, a big shift in the upper air
pattern will bring much cooler temperatures by the end of the next
work week.
For Sunday through Monday ridging will be building aloft. At the
surface, high pressure will be centered off the east coast.
Southerly winds on the back side of this high pressure will usher in
warm and moist air to the lower Ohio Valley. Temperatures on Sunday
will warm into the lower to mid 80s. Soundings show surface based
instability developing during the afternoon and little to no cap
across the area. However, with the lack of a trigger, storms look to
remain scattered in nature and should mostly dissipate during the
evening hours. For Monday soundings show more of a cap in place, so
rain chances look to be less than Sunday. However, isolated to
scattered showers and storms will still be possible. Highs will be
in the mid 80s.
A cold front will approach and move through the area during the
Tuesday through Wednesday time frame. There is still quite a bit of
discrepancy in the timing of this frontal passage. Thus, have gone
with pops over a wider time frame than is expected with the frontal
passage to account for uncertainty. For now, it looks like
Tuesday/Tuesday night will be the best chance for showers and
storms. However, if slower solutions pan out, chances will linger
into Wednesday.
The timing issue with the front will also have quite an impact on
temperatures mid week as a trough will move in behind this system.
This will usher in cooler air for the end of the week. Highs
Thursday and Friday will be in the lower to mid 60s with lows in the
upper 40s. There may be a slight chance of rain toward the end of
the long term as a weak disturbance moves through the flow aloft,
but timing with these is usually fairly questionable this far out.
&&
.AVIATION (21Z TAF Update)...
Issued at 515 PM EDT Fri May 9 2014
Updated SDF TAF to better time t-storms through the TAF site.
23Z-1Z would be the best time for SDF to see moderate t-storms
causing flight restrictions. Instability and dynamics are lacking
this far east from the current convective line near the IL/IN
border so storms are expected to decrease in intensity as they
move closer to the I-65 corridor.
Issued at 130 PM EDT Fri May 9 2014
Area of showers and isolated thunderstorms continues to progress
east over east-central KY at this time. Conditions are currently VFR
at LEX, but could briefly go MVFR around 1800-1830z with an area of
moderate-to-heavy rain approaching. Otherwise, conditions will
remain VFR at LEX, as well as SDF and BWG this afternoon in the wake
of the rain. Winds this afternoon will remain gusty up to 20 kts
from the S-SW then stay more steady from 5-12 kts tonight.
Then, attention turns to developing thunderstorms over MO near a
frontal boundary. Air mass ahead of these storms will destabilize
resulting in additional development this afternoon. Scattered to
numerous storms could then move into central KY, including SDF and
BWG this evening in the 00-06z time frame. With this in mind, have
indicated a TEMPO group for a few hours for thunderstorms and MVFR
conditions to try to narrow down the best expected time of
occurrence. The expected convection should also reach LEX later
tonight, although probably in a weakening state. Thereafter,
coverage should wane, but can`t rule out isolated or scattered
showers and storms the rest of the night, so have kept VCTS and VCSH
in at all TAFs. On Saturday, could be isolated or scattered showers
around in the morning, with scattered diurnal storms again possible
in vicinity of SDF from 18-00z.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Short Term........TWF
Long Term.........EER
Aviation..........TWF/AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
315 PM EDT Fri May 9 2014
.SHORT TERM (Now through Saturday Night)...
Issued at 305 PM EDT Fri May 9 2014
In the near term, rainfall from this morning continues to move NE
but is still hanging in there over east-central KY. The rain will
exit our forecast area in the next 1-2 hrs. Otherwise, conditions
are dry with ample cloud cover over the rest of the region, with
some cumulus clouds now starting to emerge with modest diurnal
warming and decent low-level moisture. Nevertheless, the atmosphere
remains relatively stable at this time, as evidenced by current SPC
mesoanalysis. Thus, expect mainly rain free weather for the next few
hours over central KY and south-central IN as temperatures top out
thru the 70s to around 80 west.
Meanwhile, convection continues to slowly develop along and ahead of
a low-level frontal boundary and confluent zone from southwest IL
into south-central MO. Latest SPC mesoanalysis shows an axis of -4
to -6 surface-based LI values and around 1000 J/kg CAPE in this
axis. All short-range models and the latest HRRR and SPC SREF
suggest this convection will continue to develop and expand E-NE
late this afternoon and evening. Model soundings in our area show
lapse rates increasing late this afternoon and evening, especially
aloft resulting in a more conducive environment in time to develop
and maintain convection within. As a result, will ramp up POPs this
evening, first over south-central IN and northwest KY, then eastward
later tonight.
The best chances for severe storms are to our west in the area of
the current SPC severe thunderstorm watch, enhanced by good
instability and deep-layer speed shear (with a strong upper jet
advancing eastward). As the storms move east later tonight, they may
have a tendency to become slightly elevated with modest nocturnal
cooling over our area. Nevertheless, the boundary layer may stay
adequately mixed to allow some downward momentum transport from the
strongest cells to produce isolated strong or damaging winds, mainly
along and west of the I-65 corridor. After the storms move through,
can`t totally rule out additional scattered showers and isolated
thunderstorms well after midnight and into Saturday morning as a
mid-level shortwave approaches.
During the day Saturday, the shortwave will pass through our area.
This could continue the chance for scattered showers and storms over
eastern and southern forecast area in the morning, but should
effectively clear things out later in the day. As a result, much of
the afternoon should be precipitation free with temperatures rising
through the 70s. If enough sunshine occurs in the afternoon, could
see around 80 or lower 80s in western half of forecast area.
Air mass will begin to destabilize again Saturday afternoon in the
wake of the morning showers, but forcing should be quite limited
in the wake of the morning shortwave. Therefore, expect only
isolated cell redevelopment by late afternoon mainly over western
and northern areas of forecast area. This activity could become a
little more prevalent, especially northern half of forecast area,
Saturday night if a model weak signal of another approaching
shortwave proves correct.
.LONG TERM (Sunday through Friday)...
Issued at 250 PM EDT Fri May 9 2014
The long term period will be fairly active with multiple chances for
showers and thunderstorms. In addition, a big shift in the upper air
pattern will bring much cooler temperatures by the end of the next
work week.
For Sunday through Monday ridging will be building aloft. At the
surface, high pressure will be centered off the east coast.
Southerly winds on the back side of this high pressure will usher in
warm and moist air to the lower Ohio Valley. Temperatures on Sunday
will warm into the lower to mid 80s. Soundings show surface based
instability developing during the afternoon and little to no cap
across the area. However, with the lack of a trigger, storms look to
remain scattered in nature and should mostly dissipate during the
evening hours. For Monday soundings show more of a cap in place, so
rain chances look to be less than Sunday. However, isolated to
scattered showers and storms will still be possible. Highs will be
in the mid 80s.
A cold front will approach and move through the area during the
Tuesday through Wednesday time frame. There is still quite a bit of
discrepancy in the timing of this frontal passage. Thus, have gone
with pops over a wider time frame than is expected with the frontal
passage to account for uncertainty. For now, it looks like
Tuesday/Tuesday night will be the best chance for showers and
storms. However, if slower solutions pan out, chances will linger
into Wednesday.
The timing issue with the front will also have quite an impact on
temperatures mid week as a trough will move in behind this system.
This will usher in cooler air for the end of the week. Highs
Thursday and Friday will be in the lower to mid 60s with lows in the
upper 40s. There may be a slight chance of rain toward the end of
the long term as a weak disturbance moves through the flow aloft,
but timing with these is usually fairly questionable this far out.
&&
.AVIATION (18Z TAF Update)...
Issued at 130 PM EDT Fri May 9 2014
Area of showers and isolated thunderstorms continues to progress
east over east-central KY at this time. Conditions are currently VFR
at LEX, but could briefly go MVFR around 1800-1830z with an area of
moderate-to-heavy rain approaching. Otherwise, conditions will
remain VFR at LEX, as well as SDF and BWG this afternoon in the wake
of the rain. Winds this afternoon will remain gusty up to 20 kts
from the S-SW then stay more steady from 5-12 kts tonight.
Then, attention turns to developing thunderstorms over MO near a
frontal boundary. Air mass ahead of these storms will destabilize
resulting in additional development this afternoon. Scattered to
numerous storms could then move into central KY, including SDF and
BWG this evening in the 00-06z time frame. With this in mind, have
indicated a TEMPO group for a few hours for thunderstorms and MVFR
conditions to try to narrow down the best expected time of
occurrence. The expected convection should also reach LEX later
tonight, although probably in a weakening state. Thereafter,
coverage should wane, but can`t rule out isolated or scattered
showers and storms the rest of the night, so have kept VCTS and VCSH
in at all TAFs. On Saturday, could be isolated or scattered showers
around in the morning, with scattered diurnal storms again possible
in vicinity of SDF from 18-00z.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Short Term........TWF
Long Term.........EER
Aviation..........TWF
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
145 PM EDT Fri May 9 2014
...Updated Aviation Discussion...
...Forecast Update...
Issued at 1145 AM EDT Fri May 9 2014
Band of showers continues to progress northeast over central KY at
this time. There has not been any thunderstorms in this area so far,
although latest Doppler radar is now showing increasing reflectivity
values over parts of central KY, some expect isolated/scattered
embedded cells early this afternoon as the rain continues pushing
east. The rain will exit our eastern forecast area by 19z or so.
After the rain ends, dry weather should prevail for a few hours this
afternoon over central KY and south-central IN given the absence of
enough forcing and initial instability.
In the wake of this rain, clouds should thin with some breaks of
sun, which should allow temperatures to reach near/around 80 in our
western forecast area. Low-level warming combined with increasing
mid-level lapse rates will increase instability over the lower OH
Valley this afternoon as shown nicely by latest model soundings.
Already, scattered cells are developing in central MO near frontal
zone, although these should move northeast later today and initially
not affect our area. Nevertheless, with increasing instability and
potential diurnal heating boundaries, at least scattered convection
should also develop later this afternoon just to out west and move
into central KY and southern IN late this afternoon/evening.
No major changes to tonight`s forecast at this time.
Issued at 915 AM EDT Fri May 9 2014
An elongated axis of showers with a couple embedded bands of
moderate to heavy rain and possibly an embedded elevated thunder-
storm is moving northeast quickly this morning over west-central KY,
now moving through our western forecast area. 06z model runs along
with latest high-resolution HRRR model show that this axis should
move steadily but coherently through our forecast area for the rest
of this morning into early afternoon, before exiting to our east.
Thus, have raised rainfall probabilities across our entire area.
After this rain passes by, precip will end and then the question
arises about what will happen later this afternoon. Still looks like
some diurnal heating will commence with the atmosphere becoming more
unstable. Models show that scattered convection could develop to our
west this afternoon and then move east into our area later this
afternoon and tonight. This scenario still seems reasonable,
although am not able to pin things down more specifically at this
time yet. Will continue to monitor trends through the day. No
change to temperatures for today at this time. Will evaluate this
later this morning into early afternoon.
Issued at 640 AM EDT Fri May 9 2014
Did a quick update to back off PoPs a bit in the east this morning,
but also increase PoPs slightly across our west and northwestern
areas. Based on latest radar trends, expect a band of showers to
affect portions of southern Indiana and Kentucky west of I-65 this
morning. Expect this activity to diminish in intensity and coverage
as it heads into a slightly drier and more stable airmass. Also
backed off coverage this afternoon a bit given that overall model
solutions are trending a bit drier. Likely PoPs appear to be too
aggressive at this time and have backed them off into the scattered
category. Also bumped temperatures in the west up slightly based on
the assumption of lesser precipitation.
.SHORT TERM (Now through Saturday)...
Issued at 315 AM EDT Fri May 9 2014
In the near term, partly to mostly cloudy skies will be the rule
across southern Indiana and central Kentucky this morning. Early
morning IR imagery shows plenty of high level cloudiness streaming
in from the west. Area radars are rather quiet across central KY
but there are some returns back over southeastern Missouri that are
heading eastward. We expect dry conditions for the remainder of the
early morning hours. Temperatures remain quite mild with readings
generally in the upper 60s to the lower 70s. Some of our cooler
spots appear to have decoupled a bit and are seeing temperatures
down into the upper 50s to around 60. We expect temperatures to
slowly drop a few more degrees before rebounding towards sunrise.
For Today, local and national high resolution modeling suggest area
of convection across southeastern Missouri and northeastern Arkansas
will grow upscale early this morning in response to a moderate
low-level jet axis impinging northeastward into lower Mississippi
Valley. This convection will work eastward during the morning hours
and weaken a bit as it heads into central Kentucky. Persistent
cloud cover and the remnants of this convective activity will likely
keep instability down to marginal levels across the region. That is
not to say that some areas may see stronger convection develop this
afternoon. As the morning convection heads off to the east, we may
see a few breaks develop which could lead to the development of
pockets of higher instability during the afternoon. The best
chances of this occurring would be out across the western areas.
Overall, we still do not believe today will be a total washout.
Though areas that do receive rain could get a nice soaking as the
showers and storms move through the region. Highs today look to
range from the middle to upper 70s in the west with upper 70s to
lower 80s in the east.
As we move into the evening hours, the higher resolution models do
show a secondary line of storms forming along the frontal boundary
approaching from the northwest. These storms probably will fire
along a line from Indianapolis to St. Louis early this evening and
then spread eastward into our region during the overnight period.
Depending on how fast the early morning activity clears the region
will be a determining factor in how strong the evening/overnight
convection will be. With the line expected to come through at the
time of minimum heating, we are not overly impressed with severe
potential. Strong storms are certainly possible with damaging winds
and hail being the primary threats. The activity should clear our
region by early Saturday morning with temperatures only cooling into
the mid-upper 60s.
For Saturday, skies will likely start off mostly cloudy and then
begin to clear from the west towards the east. While the upper flow
takes on more of zonal pattern, there is difficulty in determining
any real triggers for convection. Isolated-scattered convection
will be possible with the highest concentration out toward the
eastern portions of the forecast area. Though, by and large most
areas will probably see mainly dry conditions. Highs for Saturday
will be largely dependent on cloud cover during the afternoon. The
multi-model consensus suggests highs in the upper 70s to near 80 in
the west with mainly mid-upper 70s in the east.
.LONG TERM (Saturday Night through Thursday)...
Issued at 319 PM EDT Thu May 8 2014
As previously advertised, the Ohio Valley will be entering into an
active pattern with showers and thunderstorms in the forecast for
nearly every day in this period. Synoptically, Saturday will undergo
a transition to more zonal at the 500mb level as the disturbance
that brings rain to the region Friday night moves off toward the
east. The forecast challenge for Saturday is how quickly the storms
exit the forecast area as the deterministic models are struggling to
come into better agreement. The trend has been just a bit slower, as
evident from comparing previous runs with the 12Z runs. The NAM has
been the quickest and conversely, the GFS messy and the slowest. The
09Z SREF seems to be the better compromise and have leaned toward it
to show a general partial clearing from west to east throughout the
day.
Through the remainder of the weekend, much of Saturday night should
be dry before the atmosphere recharges ahead of the next system.
We`ll remain under southerly flow with high pressure centered over
the Atlantic, allowing for GoMex moisture to pool into the region.
Under this warm , moist air advection regime, Sunday`s forecast is
also a bit tricky as we could see some sporadic storms firing up,
especially with diurnal heating throughout the day. There is no
obvious signal for which portions of the forecast area will see
better rain chances than others given this type of setup so have
broad brushed low-end chance PoPs throughout. After the sun sets on
Sunday, should see a wane in storm coverage with the loss of the
aforementioned heating. Something to watch for, however, is that the
12Z NAM is hinting at a mesoscale convective system to build across
eastern KS/central MO and race off into the Great Lakes region late
Saturday night through Sunday. This is in response to a surface low
that develops just behind it. The NAM is depicting the eastern
portion of this system to break off and jet across central KY before
dying out as it loses its forcing mechanism. We`ll have to see how
this evolves as we approach that time frame.
As if the models haven`t been struggling enough, true temporal
divergence becomes evident early next week as an amplified pattern
sets up: troughing across the Plains and ridging over the East
Coast. The GFS has been consistently fast with the ECMWF much
slower. Have attempted to blend and compromise between the two,
coming to the uncertain conclusion that Tuesday looks to be the best
chance for active weather across the area. One thing the models do
agree on is the pattern change coming by the middle to end of next
week.
Given the unsettled nature of the upcoming pattern, temperature
forecasts will be difficult to nail down with certainty, with clouds
potentially wrecking havoc on the highs/lows. However, taking into
consideration the type of airmasses we`ll be under, along with climo
for this time of year, the warmest days of the long-term period will
be Sunday and Monday, with Saturday and Tuesday being slightly
cooler, and Wednesday onward dropping well below normal. This
forecast update will show highs in the upper 70s on Saturday as
clouds and precip exit; highs in the lower 80s Sunday - Monday under
southerly flow/WAA; Tuesday in the mid to upper 70s with stormy
conditions; and 60s Wednesday - Thursday. Look for lows to respond
accordingly with 60s Saturday night - Monday night and flirting with
the 50 degree mark Tuesday night - Wednesday night.
&&
.AVIATION (18Z TAF Update)...
Issued at 130 PM EDT Fri May 9 2014
Area of showers and isolated thunderstorms continues to progress
east over east-central KY at this time. Conditions are currently VFR
at LEX, but could briefly go MVFR around 1800-1830z with an area of
moderate-to-heavy rain approaching. Otherwise, conditions will
remain VFR at LEX, as well as SDF and BWG this afternoon in the wake
of the rain. Winds this afternoon will remain gusty up to 20 kts
from the S-SW then stay more steady from 5-12 kts tonight.
Then, attention turns to developing thunderstorms over MO near a
frontal boundary. Air mass ahead of these storms will destabilize
resulting in additional development this afternoon. Scattered to
numerous storms could then move into central KY, including SDF and
BWG this evening in the 00-06z time frame. With this in mind, have
indicated a TEMPO group for a few hours for thunderstorms and MVFR
conditions to try to narrow down the best expected time of
occurrence. The expected convection should also reach LEX later
tonight, although probably in a weakening state. Thereafter,
coverage should wane, but can`t rule out isolated or scattered
showers and storms the rest of the night, so have kept VCTS and VCSH
in at all TAFs. On Saturday, could be isolated or scattered showers
around in the morning, with scattered diurnal storms again possible
in vicinity of SDF from 18-00z.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........TWF
Short Term.....MJ
Long Term......BJS
Aviation.......TWF
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1118 AM CDT Fri May 9 2014
.MESOSCALE DISCUSSION...
Issued at 1117 AM CDT FRI MAY 9 2014
The explicit convection producing guidance, 3km HRRR, as well as
the 13km RUC is doing a fairly decent job of depicting the
departing and new convective activity in Missouri as of 16z
Friday. WFO LSX noted that pea (1/4") hail was reported near
Steelville MO in the axis of 600+ CAPE. This axis should continue
to translate eastward and increase to between 1000-1500 J/KG per
the 13km RUC between 17z-20z. Mid-level winds are a little
stronger than forecast between 700mb-500 mb which may accelerate
the timing and cooling aloft with the storms as they move through
Southeast Missouri and Southern Illinois. If the convection can
tap the stronger mid-level shear enough to enhance updrafts,
larger than dime/quarter size hail may be a real possibility. The
GOES Sounder Water Vapor difference channels 7.0 micron (sensitive
near 700 mb) and 7.4 micron (sensitive near 850 mb) suggesting a
sharp drying aloft moving from Oklahoma into Southwest MO ast of
1447z today. This may sharpen updraft with sharper lapse rates aloft as
storms move near the Carter to Perry County MO county western
borders, into Perry and Jackson IL county later this afternoon.
Upper level support has been forecast to be more persistent over
Southern IL...mainly between Interstate 64 corridor and Route 13,
so would not be surprised to see more robust updrafts, producing
severe hail and damaging wind gusts in that area for a more
prolonged period. Still could see some good storms in Southeast
Missouri as well as the afternoon progresses.
As we get into late evening, between 10 pm-11 pm CDT...could see
flow transition into a more repeating shower or thunderstorm
concern...with training of echoes fore more overnight persistent
rain along and mainly south of the Ohio River, but including
Southwest Indiana and the delta region of Southeast Missouri, just
north of the Bootheel.
&&
.UPDATE...
Issued at 1117 AM CDT FRI MAY 9 2014
Interim morning update to reflect marked changes in PoP, weather,
sky cover, and temperature/dewpoint to reflect recharging of
atmosphere between early morning MCS and new convective activity
on central and southern Missouri.
&&
.SHORT TERM...(Today through Sunday night)
Issued at 234 AM CDT FRI MAY 9 2014
With the approach of a frontal system and attendant H5 trough,
shower and thunderstorm activity will increase from west to east
across the region today. With the flow aloft nearly parallel to the
front combined with surface high pressure firmly planted over the
southeast US, the front will have difficulty making it too far east
over the next 18 to 24 hours.
Latest guidance shows the front moving into the western sections of
our CWA this afternoon, becoming quasi-stationary over the northern
sections by Saturday morning, then lifting back to the north as a
warm front on Saturday. With the front forecast to be in the
vicinity, precipitation chances are greatest today and tonight.
There is a slight risk of a few storms becoming severe this
afternoon with large hail and damaging winds being the main hazards.
Precipitation forecast confidence rather low Saturday, Saturday
night, and Sunday as our area will be in the warm sector and mid
level temperatures not that impressive. Low level forcing will be
negligible but ripples of mid level energy will continue to track
across left-over deep moisture, and models not in the best agreement
on where the moisture will be.
Sunday night as the next weather system takes shape over the plains,
the flow aloft turns more southwest forcing the ridging over the
southeast to build northwest into our neck of the woods. This should
limit any precipitation chances to the far northwestern and western
sections of our CWA.
Temperatures will stay at or above normal through the period.
.LONG TERM...(Monday through Thursday night)
Issued at 234 AM CDT FRI MAY 9 2014
To start out the long term period, we will be watching the evolution
of an upper trough that will be positioned in the Rockies on Monday.
As this feature slowly moves east, a sfc frontal boundary will be
making its way toward the region. It is looking more and more that
Monday might end up being dry as we wait for the incoming front.
Best chances late in the day will be in parts of southeast MO and
southern IL. There continues to be timing issues between the GFS and
ECMWF, with the GFS continuing to be the faster model but looking
back on previous runs, both models have slowed down a bit with
timing. The ECMWF seems to keep a much stronger upper high in place
over the southeastern states which slows down the progression of the
aforementioned upper trough.
The 12Z ECMWF barely has the front into the area by 12Z Tuesday,
with precip knocking on our western door, while the 00Z GFS is
showing a pretty stormy Monday night period going into Tuesday. The
00Z ECMWF is a bit faster but still not as fast as the GFS. The
front continues to move east during the day on Tuesday and plan on
keeping likely pops right now as there seems to be good consistency
for that day so far. When to exit the precipitation though, will be
another story. The 00Z GFS moves the activity out of the area
Tuesday night while the slower ECMWF takes until Wednesday morning
to dry us out. Plus, the 00Z ECMWF indicates another wave of
precipitation coincident with the main upper trough as it moves
through Tuesday night into early Wednesday.
These timing issues also play a big role in determining
temperatures. The faster GFS is indicating that the colder air will
filter in as early as Tuesday, making for a much cooler day than the
slower ECMWF would suggest. Wednesday`s temps though will be a bit
easier since we should have the colder air mass into the area by
then. With 850 mb temps in the single digits, we will definitely
feel like fall has returned briefly, as we struggle to get out of
the 60s in some places. Looking at some of the CIPS analog guidance,
there is even more confidence that highs in the 60s appear likely
with this colder air mass coming in. Highs in Thursday will be even
more of a challenge since the GFS turns winds around to southerly,
which warms us up, but the ECMWF maintains a colder northwest
wind.
&&
.AVIATION...
Issued at 642 AM CDT FRI MAY 9 2014
At KCGI/KPAH MVFR cigs/vsbys possible between 20-02Z in TSRA...
otherwise VFR. At KEVV/KOWB MVFR cigs/vsbys in TSRA between
12-16Z, then again between 23-04Z...otherwise VFR. Southerly winds
aob 10 knots early should increase to 10-12 knots with gusts up
to 18-20 knotsafter 15Z, then drop back to aob 10 knots after 00Z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
MESOSCALE...Smith
UPDATE...Smith
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
116 PM CDT FRI MAY 9 2014
.AVIATION...
AFTER A MORNING OF IFR CEILINGS AND VCTS ACROSS SEVERAL TERMINALS...
CEILING`S HAVE LIFTED AND OUR SCATTERED OUT ACROSS SOME TERMINALS
EARLY THIS AFTERNOON. STILL DEALING WITH MVFR CONDITIONS HOWEVER
AT THE ELD/LFK AND SHV TERMINALS. THIS SHOULD BE TEMPORARY WITH
CEILING`S LIKELY CLIMBING ABOVE 3KFT OVER THE NEXT HOUR OR SO.
CONVECTION FOR THE MOST PART HAS MOVED SOUTH AND EAST OF OUR
TERMINALS BUT LEFT MENTION OF VCTS AT THE LFK/MLU TERMINALS
THROUGH THE AFTERNOON. HRRR SHOWING REDEVELOPMENT ACROSS THE
REGION LATER THIS AFTERNOON...AND FOR THAT REASON...HAVE
REINTRODUCED VCTS AT SEVERAL TERMINAL LOCATIONS THROUGH THE
EVENING.
BY LATE EVENING/OVERNIGHT...MOS CEILING CATEGORIES SUPPORT A
RETURN OF MVFR/IFR CEILINGS AREAWIDE WITH SOME 3-5SM VISIBILITIES.
KEPT THIS RUNNING THROUGH AT LEAST MID MORNING ON SATURDAY WITH
IFR CEILINGS LIKELY NOT LIFTING UNTIL AFTER 15Z ON SATURDAY.
13
&&
.PREV DISCUSSION... /ISSUED 1126 AM CDT FRI MAY 9 2014/
DISCUSSION...
ONGOING CONVECTION MAINLY SOUTH OF I-20 LATE THIS MORNING WITH
SOME IMPRESSIVE RAINFALL RATES/TOTALS ACROSS PARTS OF DEEP E
TX...PROMPTING A FLASH FLOOD WARNING FOR THIS AREA. ELSEWHERE
ALONG AND SOUTH OF I-20...JUST SPOTTY SHWRS AND A FEW TSTMS NOTED
ON RADAR WITH CLOUDS TRYING TO ERODE OVER PORTIONS OF NE TX WITH A
COLD FRONTAL BNDRY JUST TO OUR WEST. THIS BNDRY IS EXPECTED TO
WEAKEN AND TRACK JUST NORTH OF OUR REGION THIS AFTERNOON WITH A
FEW UPPER LEVEL DISTURBANCES TRANSITIONING EWRD WITH THE FRONT.
THEREFORE...ADDITIONAL CONVECTION IS EXPECTED TO DEVELOP LATER
THIS AFTERNOON WITH SOME STRONG TO POSSIBLY ISOLD SEVERE TSTMS.
THE THREATS WITH ANY OF THESE TSTMS WILL BE LIMITED TO DAMAGING
WINDS AND HAIL AS INDICATED BY THE DAY 1 SPC CONVECTIVE OUTLOOK.
AS FAR AS CHANGES TO THE FORECAST...DID MAKE UPWARD ADJUSTMENTS TO
POPS MAINLY ALONG AND SOUTH OF I-20 WHERE MORNING CONVECTION IS
CONCENTRATED. ALSO LOWERED FORECAST HIGHS JUST A BIT CONSIDERING
THE ABUNDANT CLOUD COVER AND CONVECTION...ALTHOUGH WOULD NOT BE
SURPRISED TO SEE A FEW AREAS SQUEAK OUT MID OR EVEN UPPER 80S
WHERE CLOUDS BREAK EARLIER AND CONVECTION IS KEPT AT BAY. NEW QPF
NUMBERS HAVE ALSO BEEN LOADED INTO THE GRIDS. UPDATED PRODUCTS
HAVE ALREADY BEEN SENT. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 68 87 70 86 71 / 20 20 20 20 20
MLU 67 87 69 86 69 / 30 20 20 20 20
DEQ 64 86 67 84 70 / 20 20 20 20 20
TXK 67 86 68 85 68 / 20 20 20 20 20
ELD 66 86 68 85 68 / 30 20 20 20 20
TYR 68 87 70 86 71 / 20 20 10 20 20
GGG 67 88 69 86 71 / 20 20 10 20 20
LFK 69 88 71 87 72 / 20 20 10 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
13
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
400 PM EDT FRI MAY 9 2014
.SHORT TERM...THIS EVENING AND TONIGHT
CLOUDS AND SHALLOW EARLY AFTERNOON CONVECTION HAVE RESULTED IN A
RATHER NEBULOUS PICTURE FOR THUNDERSTORM POTENTIAL THIS EVENING.
ABUNDANT MID AND HIGH CLOUDS HAVE LIMITED BOUNDARY LAYER RECOVERY IN
THE WAKE OF THE PASSING CONVECTION, ALTHOUGH MID 70S TEMPS AND
DEWPOINTS AROUND 60 ARE MAKING A RENEWED PUSH INTO SOUTHWEST LOWER
MICHIGAN DURING THE MID AFTN AND CLOUD OPACITY IS DECREASING.
MESOANALYSIS SHOWS MUCAPES AT A RATHER MODEST 500 J/KG OVER WESTERN
LOWER FOR NOW...BUT THE 12Z NAM AND RECENT RUNS OF THE RUC SUGGEST A
RECOVERY TO 1000 J/KG CAPE BY AROUND 22Z IN ADVANCE OF THE
APPROACHING COLD FRONT. THE OVERZEALOUS HANDLING OF QPF BY TODAY`S
NWP MAKES THE PROGGED RECOVERY ALL THE MORE IMPRESSIVE. HOWEVER, IN
AND AN ATTEMPT TO ADDRESS UNCERTAINTIES REGARDING BOTH THE MID-LEVEL
AND LOW-LEVEL THERMODYNAMIC ENVIRONMENT RESULTING FROM BOTH POOR
MODEL PERFORMANCE AND EARLY CONVECTION, A SPECIAL SOUNDING WAS
LAUNCHED AT APPROXIMATELY 1930Z. THE DATA WILL BECOME AVAILABLE
SHORTLY AFTER ISSUANCE OF THE AFTERNOON PACKAGE. FINALLY, ALTHOUGH
ANY CONVECTION THAT BUBBLES UP IN ADVANCE OF THE FRONT MAY BEGIN TO
LOOSE FOOTING IN THE BOUNDARY LAYER AROUND 00Z...STEEPENING
MID-LEVEL LAPSE RATES WILL MAINTAIN RESPECTABLE MID-LEVEL
INSTABILITY WELL INTO THE EVENING HOURS AND MAY EVEN ALLOW A HAIL
THREAT TO DEVELOP IN ADDITION TO WIND AS UPDRAFTS ARE ALLOWED TO
DEEPEN. WIDESPREAD SEVERE WEATHER IS NOT EXPECTED...PARTICULARLY
GIVEN PARALLEL NATURE OF THE MEAN FLOW TO THE INITIATING
BOUNDARY...BUT AT LEAST A MARGINAL THREAT WILL EXIST DEPENDING ON
THE BEHAVIOR OF INDIVIDUAL CELLS. WILL MAINTAIN CHANCE POPS
THROUGH THE EVENING HOURS AND MENTION A RISK OF AT LEAST ISOLATED
WIND/HAIL THREATS DEVELOPING OVER THE NEXT SEVERAL HOURS IN THE HWO.
THE GREATEST THREAT WILL BE FOCUSED FURTHER SOUTH AND WEST WHERE
INSTABILITY WILL BE MAXIMIZED.
&&
.LONG TERM...
DIFFERENTIAL HEIGHT RISES BEHIND THE DEPARTING SHARP MIDLEVEL
TROUGH AXIS WILL LEAD TO A SURFACE RIDGE ACROSS SOUTHEASTERN
MICHIGAN ON SATURDAY. DRYING SIGNAL IN THE 925-850MB LAYER SUPPORTS
THE FORECAST SOUNDINGS OF LCL HEIGHTS EVENTUALLY REACHING A VERY
HIGH 6000 FT AGL. THE ENVIRONMENT FAVORABEL FOR DEEP TURBULUENT
MIXING WILL EVENTUALLY ALLOW BREEZY WESTERLIES TO DEVELOPM DURING
THE LATE AFTERNOON. SURFACE WIND GUSTS ARE EXPECTED TO REACH 25 TO
30 KNOTS. FORECASTED SOUNDINGS FOR SATURDAY ARE NOW QUITE A BIT
DIFFERENT WITH ANY EXPECTED MIDLEVEL LAPSE RATES. IN FACT...POCKET
OF STEEP MIDLEVEL LAPSE RATES IS NOWHERE TO BE SEEN...SUGGESTING
THAT EVEN A SCATTERED CU FIELD WILL BE DIFFICULT. HIGHS SATURDAY
WILL BE COOLER...READING REACHING THE UPPER 60S FOR MANY AREAS...72
OR 73 DEGREES FOR THE HIGHER SURFACE PRESSURE/LOWER TERRAIN
LOCATIONS ACROSS THE EXTREME SOUTHEAST.
THE INBOUND LONGWAVE RIDGE WILL BE VERY PROGRESSIVE DURING THE
LATTER HALF OF THE WEEKEND...AMPLIFYING AS WELL. PRECEDING MID TO
UPPER LEVEL TROPSOPHERIC DEFORMATION IS PROGGED TO BE VERY GOOD
WHICH WILL AID IN THE RAPID DEVELOPMENT OF A WARM FRONT BY SUNDAY.
EARLY PART OF THE DAY IS EXPECTED TO BE QUIET WITH VERY DRY AIR IN
RESIDENCE DURING THE MORNING. WIND TRAJECTORIES WILL EVENTUALLY VEER
SOUTHWESTERLY WHICH WILL ALLOW WARMTH AND INSTABILITY TO INCREASE
FOR THE AFTERNOON. THE SUNDAY PERIOD HAS BEEN A NOISY ONE WITHIN THE
MODELS SO CONFIDENCE IS NOT OVERLY HIGH...ESPECIALLY WITH REGARDS TO
TIMING. HOWEVER...ENOUGH UPPER LEVEL FORCING APPEARS TO BE COMING
TOGETHER SUPPORTIVE OF A MID CHANCE POP IN THUNDERSTORMS FOR THE
SOUTHERN HALF OF THE CWA. THE LATE AFTERNOON PUSH WITH WARMTH WILL
ALLOW TEMPERATURES TO REACH THE MID 70S FOR MANY LOCATIONS.
MONDAY WILL BEGIN A PERIOD OF ACTIVE WEATHER FOR THE EXTENDED AS A
WARM FRONT LIFTS NORTH INTO THE TRI CITIES AREA. AGAIN...WARM AND
MOIST AIR WILL ADVECT NORTH VIA A 40KT H85 JET. THIS WILL BRING PWAT
VALUES OVER 1.5 INCHES. WILL CONTINUE TO TREND UPWARD WITH POPS 50
TO 60 PERCENT. THE COLD FRONT WILL SWING THROUGH ON TUESDAY AND
CONTINUE THE HIGH POP EVENT. BOTH DAYS POSE THE THREAT FOR THUNDER
AS LI/S WILL BE NEGATIVE. MUCH LIKE THE PAST 2 DAYS HERE...MONDAY IN
THE WARM SECTOR WILL REMAIN CAPPED BUT WITH CAPE WELL OVER 2500
J/KG. TUESDAY WILL HAVE MORE POTENTIAL WITH THE STRONGER
FORCING...BUT LOWER CAPE VALUES. CHANCE POPS WILL ALSO BE IN THE
FORECAST WEDNESDAY AS REMNANT MOISTURE FROM THE SLOW CHURNING LOW
PRESSURE REMAINS PROXIMAL TO THE AREA. THIS WILL BE ALONG WITH A
GENERAL THUNDER THREAT. THE REST OF THE PERIOD STILL LOOKS TO REMAIN
COOL WITH TEMPS BELOW CLIMO.
&&
.MARINE...
A STRONGLY STABLE PROFILE OVER THE GREAT LAKES WILL KEEP WIND GUSTS
MAINLY UNDER 30 KNOTS. THE COLD FRONT WILL TRACK ACROSS LAKE HURON
THIS EVENING AND WILL BE MARKED BY A VEERING OF THE WIND TO THE
SOUTHWEST. THE POST FRONTAL COLD AIR ADVECTION IN THE WAKE OF THE
FRONT WILL NOT BE SIGNIFICANT ENOUGH TO OVERCOME THE STRONG OVER
LAKE STABILITY. THUS WINDS WILL REMAIN MAINLY UNDER 25 KNOTS ON
SATURDAY. WINDS WILL QUICKLY DIMINISH SATURDAY NIGHT AS SFC HIGH
PRESSURE MOVES OVER THE LAKES. A WARM FRONT WILL SLOWLY LIFT ACROSS
THE REGION SUN NIGHT THROUGH MONDAY NIGHT. THE CONTINUED STRONG
STABILITY WILL KEEP WINDS AND WAVES IN CHECK. HOWEVER...THERE WILL
BE A GOOD CHANCE FOR THUNDERSTORMS THROUGH THE PERIOD.
&&
.AVIATION...ISSUED 1251 PM EDT FRI MAY 9 2014
//DISCUSSION...
SHODDY COVERAGE OF PRECIPITATION ACROSS THE LOWER PENINSULA THIS
MORNING WILL SUPPORT AN INCREASED RISK OF INSTABILITY CAPABLE OF
SUPPORTING ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT THIS
AFTERNOON. INITIAL BAND OF SHOWERS LIFTING ACROSS SOUTHEAST MICHIGAN
AROUND 17Z WILL EXIT THE AREA SHORTLY AND WILL BE FOLLOWED BY A LULL
PRIMARILY CONSISTING OF VFR...OCCASIONAL LIGHT RAINFALL...AND
POCKETS OF LOW VFR CEILING. REDEVELOPMENT IS EXPECTED MID-AFTERNOON
WITH AN INCREASED RISK OF SOME STORMS BECOMING STRONG TO SEVERE.
GUSTY SOUTH-SOUTHWEST FLOW WILL PERSIST THROUGH THE EVENING BEFORE
VEERING TO A MORE WESTERLY DIRECTION IN THE WAKE OF THE COLD FRONT
AFTER 00Z.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE IN CEILINGS BELOW 5KFT
* MEDIUM CONFIDENCE THAT TSTORMS WILL IMPACT KDTW
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...JVC
LONG TERM....CB/MM
MARINE.......CB
AVIATION.....JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
346 PM EDT FRI MAY 9 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 444 AM EDT FRI MAY 9 2014
THE UPPER TROUGH THAT HAS BEEN CONTROLLING OUR WEATHER FOR THE LAST
COUPLE OF DAYS IS CURRENTLY MOVING NORTHEAST THROUGH THE CENTRAL
PLAINS. MOISTURE LADEN AIR STREAMING NORTHEAST AHEAD OF THIS TROUGH
CAN BE SEEN ON WV IMAGERY EARLY THIS MORNING...WHICH IS HELPING TO
FUEL SHOWERS AND ISOLATED THUNDERSTORMS FROM WESTERN LAKE SUPERIOR
THROUGH PORTIONS OF UPPER MICHIGAN...AND SOUTHEAST TO EASTERN
WISCONSIN. AT THE SURFACE...A 998MB LOW IS LOCATED JUST SOUTHWEST OF
DULUTH AND A WARM FRONT STRETCHES EAST ALONG THE U.P. AND
WISCONSIN BORDER. SHORTWAVES EMBEDDED WITHIN THE WARM MOIST
SOUTHWESTERLY FLOW CONTINUES TO PRODUCE AREAS OF THUNDERSTORMS OVER
THE WESTERN HALF OF THE GREAT LAKES REGION AND EXPECT THAT TO
CONTINUE FOR AREAS WITHIN THE WARM/MOIST AIRMASS.
AS THE LOW LIFTS NORTHEAST TODAY...THE COLD FRONT (CURRENTLY
STRETCHING SOUTH FROM SOUTHEAST MINNESOTA THROUGH NORTHERN
MISSOURI) WILL SWEEP NORTHEAST ACROSS THE UPPER GREAT LAKES REGION.
WITH THE SHOWER/THUNDERSTORM COVERAGE STARTING TO BECOME MORE
SCATTERED/ISOLATED...WILL FOLLOW THAT IDEA FOR POPS AHEAD OF THE
COLD FRONT. ALREADY STARTING TO SEE THE AFFECT OF THE DRYING ALOFT
OVER NORTHWEST WISCONSIN AND EXPECT THE LAST AREAS OF SHOWERS FOR
THIS MORNING TO PUSH THROUGH WESTERN UPPER MICHIGAN OVER THE NEXT
COUPLE OF HOURS. AS THAT DRYING SHIFTS EAST THIS MORNING...WILL
DIMINISH POPS FROM WEST TO EAST DURING THE MORNING HOURS. WITH
THERE STILL BEING SOME ISOLATED THUNDER ON THE BACK EDGE OF THE
PRECIPITATION (EVEN THOUGH RAP ANALYSIS OF MUCAPE AND MID-LEVEL
LAPSE RATE VALUES ARE VERY WEAK)...HAVE EXTENDED THE SLIGHT
CHANCE OF THUNDER A LITTLE LONGER OVER THE EAST THIS MORNING TO
COINCIDE WITH THE AXIS OF MOISTURE AND LATEST THUNDER
AREAS.
BEHIND THE COLD FRONT...MAY SEE A FEW PEAKS OF SUNSHINE OVER THE
CENTRAL/EAST (WHERE FOG ISN/T OCCURRING) AS THIS MID LEVEL DRY SLOT
MOVES THROUGH AND BEFORE THE NEXT WAVE OF LOW LEVEL MOISTURE AND
PRECIPITATION (CURRENTLY IN THE EASTERN DAKOTAS AND WESTERN
MINNESOTA) MOVES OVER THE AREA. WILL CONTINUE THE IDEA SHOWN IN THE
PREVIOUS FORECAST OF ISOLATED TO SCATTERED SHOWERS MOVING OVER THE
WEST OR NORTHWEST HALF OF THE CWA LATER THIS AFTERNOON AND
CONTINUING THROUGH A GOOD PORTION OF THE NIGHT TONIGHT (ESPECIALLY
THE KEWEENAW TONIGHT). QPF AMOUNTS WILL BE MUCH LIGHTER THAN SEEN
OVER THE LAST COUPLE DAYS AND MAINLY BETWEEN A TRACE AND A COUPLE
TENTHS. IN ADDITION...IT WILL BECOME BREEZY BEHIND THE COLD
FRONT...WITH BUFKIT SOUNDINGS INDICATING GUSTS AROUND 25KTS OVER
MUCH MUCH OF UPPER MICHIGAN TODAY. WITH THE COLD AIR ADVECTION IN
PLACE THROUGH MUCH OF TONIGHT...THOSE GUSTS WILL LIKELY KEEP UP AS
WINDS SHIFT TO THE WEST THROUGH THE NIGHT. WHILE THE KEWEENAW MAY BE
PROTECTED SLIGHTLY TODAY...THE WINDS SHOULD REALLY KICK IN TONIGHT
AS IT IS CLOSEST TO THE TIGHTEST PRESSURE GRADIENT WITH THE
DEPARTING LOW AND RESULTING STRONGER WINDS JUST ABOVE THE SURFACE.
EXPECT THERE TO BE A PERIOD THIS EVENING AND INTO THE EARLY
OVERNIGHT HOURS WHERE GUSTS IN THE KEWEENAW WILL BE BETWEEN
30-35KTS.
FINALLY FOR TEMPERATURES...VALUES THIS MORNING HAVE BEEN CONSISTENT
IN THE 50S OVER THE INTERIOR LOCATIONS...ALTHOUGH LOCATIONS NEAR
THE COOLING OF THE GREAT LAKES HAVE BEEN BOUNCING UP AND DOWN
DEPENDING ON THE WIND DIRECTION. WITH THE WARM START AND THE WARM
FRONT PUSHING NORTHEAST THROUGH MUCH OF UPPER MICHIGAN
TODAY...SHOULD SEE TEMPERATURES RISE INTO THE MID-UPPER 60S OVER
THE CENTRAL/EASTERN CWA AND WHERE SOME SUNSHINE OCCURS WILL
PROBABLY SEE SOME SITES HITTING THE 70 DEGREE MARK. COLDER AIR
ARRIVING BEHIND THE COLD FRONT WILL LEAD TO FALLING TEMPS OVER THE
WEST IN THE AFTERNOON AND THE REST OF THE AREA TOWARDS EVENING. THE
CLOUD COVER TONIGHT WILL KEEP TEMPS A LITTLE ABOVE NORMAL AND HAVE
LOWS IN THE LOWER 40S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 343 PM EDT FRI MAY 9 2014
MAIN FCST CONCERNS FOR LATER IN THE WEEKEND INVOLVE POPS ASSOCIATED
WITH SHRTWV FCST TO LIFT INTO THE UPR LKS SAT NGT INTO SUN OUT OF A
DEEPENING TROF OVER THE W. A MORE IMPORTANT/WETTER LO PRES IS LIKELY
TO IMPACT THE AREA ON MON INTO TUE WITH INCRSG SW FLOW ALF BTWN THE
DEEPENING UPR TROF IN THE PLAINS AND BLDG UPR RDG OVER THE SE CONUS.
SAT NGT/SUN...SHRTWV EJECTING OUT OF A DEEPENING UPR TROF OVER THE W
IS FCST TO BE MOVING THRU SW MN AT 00Z SUN INTO THE UPR LKS BY 12Z
SUN. BUT SINCE AN UPR RDG AXIS IS FCST TO SHARPEN OVER UPR MI TO THE
NW OF BLDG MEAN RDG OVER THE SE CONUS AND ON SW FLANK OF MORE
PERSISTENT TROFFING OVER SE CANADA THAT WL MAINTAIN A SOURCE OF LLVL
DRY AIR...SUSPECT SHRA ASSOCIATED WITH THE SHRTWV APRCHG FM THE SW
WL DIMINISH WITH TIME AND TOWARDS THE NE. IN FACT...BULK OF MODELS
SHOW DIMINISHING DEEP LYR QVECTOR CNVGC/MID LVL RH AS THE SHRTWV
MOVES THRU UPR MI. MAINTAINED FLAVOR OF GOING FCST SHOWING ARRIVAL
OF CHC POPS FM THE SW ON SAT NGT BUT THEN DIMINISHING AS SHOWER
AREA MOVES TO THE NE ON SUN.
SUN NGT...AS STRONGER SHRTWV BEGINS TO EJECT OUT OF DEEPENING UPR
TROF MOVING SLOWLY THRU THE ROCKIES...SFC LO PRES IS FCST TO
ORGANIZE IN THE CENTRAL PLAINS TO THE SW OF SFC HI PRES EXTENDING FM
FAR NW ONTARIO INTO THE UPR LKS. ALTHOUGH THE EVNG MAY BE DRY
ESPECIALLY OVER THE N HALF OF THE CWA CLOSER TO DRY LLVL NE
TRAJECTORIES OUT OF THE HI IN ONTARIO...MOST OF THE MODELS SHOW HIER
MID LVL RH/SOME PCPN ARRIVING FM THE SW THRU THE NGT WITH SOME
ISENTROPIC ASCENT N OF H85 WARM FNT FCST TO REACH SRN WI BY 12Z MON.
WL MAINTAIN HI CHC/LIKELY POPS NEAR THE WI BORDER LATE AT NGT...
WITH DCRSG POPS TO THE N TOWARD THE DRIER AIR. TENDED TO SHARPEN THE
GRADIENT OF THE POPS ON THE NRN EDGE OF THE PCPN SHIELD TO REFLECT
THE IMPACT OF THIS DRY AIR.
MON THRU TUE...SHRTWV EJECTING OUT OF HI AMPLITUDE UPR TROF SHIFTING
SLOWLY EWD INTO THE PLAINS WL CAUSE SFC LO IN THE CENTRAL PLAINS AT
12Z MON TO LIFT NNEWD AND THRU MN ON TUE. MODELS APPEAR TO BE
MAINTAINING TREND TOWARD A SLOWER...FARTHER W TRACK FOR THE SFC
LO...NOT SURPRISING CONSIDERING THE HI AMPLITUDE PLAINS TROF/ERN RDG
PATTERN TAKING SHAPE. SINCE THE SFC LO IS TRENDING TO MOVE SLOWER TO
THE NE AND THE UPR RDG IS STILL BLDG INTO THE GREAT LKS ON MON...
SUSPECT WDSPRD WAD RA WL BE SLOWER TO MOVE N THRU THE CWA TO THE N
OF WARM FNT HUNG UP TO THE S. WHEN THE SFC LO FINALLY SHIFTS TO THE
N ON MON NGT/TUE...MORE WDPSRD SHRA/EVEN SOME TS ARE LIKELY TO MOVE
N WITH H85 WARM FROPA/H85 TEMPS RISING TO 14C OVER THE SE CWA. ANY
TS WL BE ELEVATED AS LONGER RANGE MODELS SHOW SFC WARM FNT REMAINING
TO THE S WITH TRIPLE PT LO SHIFTING THRU NW LOWER MI TO THE SE OF
OCCLUDED LO MOVING THRU MN. WITH PWAT FCST TO REACH 1.25-1.50 INCH/
UP TO 225 PCT OF NORMAL...HEAVY RA MAY FALL DURING THIS EVENT AND
CAUSE RIVER LVLS TO RISE AGAIN. DRIER AIR ALF WL MOVE IN FM THE WSW
ON TUE FOLLOWING OCCLUDED FROPA AND DIMINISH THE POPS.
EXTENDED...AS SLOW MOVING UPR TROF SWINGS INTO THE GREAT LKS ON WED
INTO FRI...A VERY COOL AIRMASS WITH H85 TEMPS AS LO AS -5C WL IMPACT
UPR MI WX. WITH THE PASSAGE OF SEVERAL SHRTWVS AND A MOIST CYC
FLOW...SOME -SHRA...MIXED WITH SOME SN...WL BE PSBL. SO MAINTAINED
LO CHC POPS SHOWN BY THE MODEL CONSENSUS. PCPN DURING THE DAY SHOULD
SHIFT TO MAINLY OVER THE INTERIOR AS THE COOLER LKS WL ACT AS A
STABILIZING IFNLUENCE. BLO NORMAL TEMPS WL BE THE RULE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 139 PM EDT FRI MAY 9 2014
LOW PRESSURE TRACKING JUST NE OF UPPER MI WILL BRING A COLD FRONT
WEST TO EAST ACROSS ALL SITES THIS AFTERNOON AND EVENING. ABUNDANT
LOW-LEVEL MOISTURE AND UPSLOPE FLOW SHOULD RESULT IN IFR CIGS AT CMX
AND IWD OVERNIGHT ALONG WITH -SHRA. DOWNSLOPE FLOW WILL LIMIT SAW TO
MVFR CIGS. EXPECT ALL SITES TO BECOME VFR WITH CLEAR SKIES BY SAT
MORNING AS DRY AIR PUSHES ACROSS THE AREA. DECENT MIXING AND
STRONGER WINDS ALOFT WILL BRING GUSTY WINDS TO ALL SITES INTO
SAT...ESPECIALLY FOR CMX...WHERE GUSTS OVER 30KTS WILL BE POSSIBLE
LATE THIS EVENING THROUGH THE OVERNIGHT HOURS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 422 AM EDT FRI MAY 9 2014
A LOW PRESSURE SYSTEM NEAR DULUTH EARLY THIS MORNING WILL SLIDE
NORTHEAST INTO ONTARIO TODAY. AS THIS OCCURS...WINDS WILL SHIFT
AROUND TO THE SOUTHWESTERLY DIRECTION TODAY AND THEN TO THE WEST
TONIGHT. EXPECT THE WINDS TO INCREASE FROM WEST TO EAST TODAY AND
GENERALLY TO 25KTS TONIGHT...ALTHOUGH THERE COULD BE SOME GUSTS
TO 30KTS OVER THE CENTRAL LAKE. THESE STRONGER WINDS...COMBINED WITH
GRADUALLY DRYING LOWER LEVELS SHOULD LEAD TO A DIMINISHMENT OF THE
DENSE FOG OVER LAKE SUPERIOR FROM SOUTHWEST TO NORTHEAST TODAY.
OPTED TO EXTENDED THE DENSE FOG ADVISORY FOR LAKE SUPERIOR INTO THE
AFTERNOON HOURS TO BETTER MATCH UP WITH THE INCREASING WINDS AND
DRIER AIR. A HIGH PRESSURE RIDGE WILL THEN SLIDE OVER THE AREA ON
SATURDAY AND LEAD TO WINDS FALLING BELOW 15KTS SATURDAY NIGHT. THESE
LIGHT WINDS WILL REMAIN THROUGH SUNDAY EVENING. A LOW PRESSURE
SYSTEM MOVING TOWARDS THE UPPER GREAT LAKES REGION FROM THE CENTRAL
PLAINS ON SUNDAY NIGHT WILL LEAD TO INCREASING EASTERLY WINDS (TO
25KTS BY MONDAY EVENING). THEN AS THE LOW SHIFTS NORTHEAST INTO
ONTARIO ON TUESDAY...WINDS WILL SHIFT TO THE SOUTHWEST AND STAY
BELOW 20KTS.
&&
.HYDROLOGY...
ISSUED AT 343 PM EDT FRI MAY 9 2014
RUNOFF FROM RECENT HEAVY RAIN...THAT REACHED UP TO AN INCH OR TWO AT
SOME PLACES OVER NW UPR MI THE PAST FEW DAYS...AND MELTING OF THE
LINGERING SNOW PACK OVER THE HIER TERRAIN ACCELERATED BY THE ARRIVAL
OF WARMER...RATHER HUMID AIR /SFC DEWPTS IN THE 50S/ HAVE CAUSED
AREA RIVER LEVELS TO RISE AGAIN...ESPECIALLY OVER THE W HALF OF UPR
MI. THE TRAP ROCK RIVER IN HOUGHTON COUNTY ROSE ABOVE FLOOD STAGE
EARLY THIS MRNG TO THE HIEST LEVEL ON RECORD /10.8 FT/...AND THE
STURGEON RIVER AT ALSTON AND CHASSELL ARE ALSO ABOVE BANKFULL.
FORTUNATELY...ONLY SOME SCATTERED LIGHT SHOWERS ARE IN THE FORECAST
FOR TONIGHT AND SAT NIGHT INTO SUN...WITH A DRY DAY FOR MOST ON SAT.
SINCE THE TRAP ROCK IS A NOTORIOUSLY FAST RESPONDING STREAM...THIS
RIVER HAS ALREADY FALLEN BELOW FLOOD STAGE AS THE SHORTER TERM HEAVY
RAIN RUNOFF HAS ALREADY FLOWED THROUGH THAT BODY OF WATER. BUT
ADDITIONAL RUNOFF FROM PAST RAIN AND THE MELT DOWN OF THE REST OF
THE SNOW PACK WILL ALLOW SLOWER RESPONDING RIVERS TO CONTINUE RISING
INTO THE WEEKEND. THE ADVISORIES FOR THE STURGEON RIVER AT ALSTON
AND CHASSELL ARE IN EFFECT INTO SUN. OVERALL...STREAMS AND RIVERS
WILL REMAIN HI INTO NEXT WEEK...WITH ADDITIONAL HEAVY RA POSSIBLE ON
MON INTO TUE. THOSE LIVING NEAR RIVERS...CREEKS...AND STREAMS SHOULD
CONTINUE TO MONITOR RIVER LEVELS IN CASE ADDITIONAL FLOOD WARNINGS
OR ADVISORIES ARE NECESSARY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 5 PM EDT /4 PM CDT/ THIS AFTERNOON FOR
LSZ162-240>251-263>267.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LMZ248-250.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...KLUBER
MARINE...SRF
HYDROLOGY...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
140 PM EDT FRI MAY 9 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 444 AM EDT FRI MAY 9 2014
THE UPPER TROUGH THAT HAS BEEN CONTROLLING OUR WEATHER FOR THE LAST
COUPLE OF DAYS IS CURRENTLY MOVING NORTHEAST THROUGH THE CENTRAL
PLAINS. MOISTURE LADEN AIR STREAMING NORTHEAST AHEAD OF THIS TROUGH
CAN BE SEEN ON WV IMAGERY EARLY THIS MORNING...WHICH IS HELPING TO
FUEL SHOWERS AND ISOLATED THUNDERSTORMS FROM WESTERN LAKE SUPERIOR
THROUGH PORTIONS OF UPPER MICHIGAN...AND SOUTHEAST TO EASTERN
WISCONSIN. AT THE SURFACE...A 998MB LOW IS LOCATED JUST SOUTHWEST OF
DULUTH AND A WARM FRONT STRETCHES EAST ALONG THE U.P. AND
WISCONSIN BORDER. SHORTWAVES EMBEDDED WITHIN THE WARM MOIST
SOUTHWESTERLY FLOW CONTINUES TO PRODUCE AREAS OF THUNDERSTORMS OVER
THE WESTERN HALF OF THE GREAT LAKES REGION AND EXPECT THAT TO
CONTINUE FOR AREAS WITHIN THE WARM/MOIST AIRMASS.
AS THE LOW LIFTS NORTHEAST TODAY...THE COLD FRONT (CURRENTLY
STRETCHING SOUTH FROM SOUTHEAST MINNESOTA THROUGH NORTHERN
MISSOURI) WILL SWEEP NORTHEAST ACROSS THE UPPER GREAT LAKES REGION.
WITH THE SHOWER/THUNDERSTORM COVERAGE STARTING TO BECOME MORE
SCATTERED/ISOLATED...WILL FOLLOW THAT IDEA FOR POPS AHEAD OF THE
COLD FRONT. ALREADY STARTING TO SEE THE AFFECT OF THE DRYING ALOFT
OVER NORTHWEST WISCONSIN AND EXPECT THE LAST AREAS OF SHOWERS FOR
THIS MORNING TO PUSH THROUGH WESTERN UPPER MICHIGAN OVER THE NEXT
COUPLE OF HOURS. AS THAT DRYING SHIFTS EAST THIS MORNING...WILL
DIMINISH POPS FROM WEST TO EAST DURING THE MORNING HOURS. WITH
THERE STILL BEING SOME ISOLATED THUNDER ON THE BACK EDGE OF THE
PRECIPITATION (EVEN THOUGH RAP ANALYSIS OF MUCAPE AND MID-LEVEL
LAPSE RATE VALUES ARE VERY WEAK)...HAVE EXTENDED THE SLIGHT
CHANCE OF THUNDER A LITTLE LONGER OVER THE EAST THIS MORNING TO
COINCIDE WITH THE AXIS OF MOISTURE AND LATEST THUNDER
AREAS.
BEHIND THE COLD FRONT...MAY SEE A FEW PEAKS OF SUNSHINE OVER THE
CENTRAL/EAST (WHERE FOG ISN/T OCCURRING) AS THIS MID LEVEL DRY SLOT
MOVES THROUGH AND BEFORE THE NEXT WAVE OF LOW LEVEL MOISTURE AND
PRECIPITATION (CURRENTLY IN THE EASTERN DAKOTAS AND WESTERN
MINNESOTA) MOVES OVER THE AREA. WILL CONTINUE THE IDEA SHOWN IN THE
PREVIOUS FORECAST OF ISOLATED TO SCATTERED SHOWERS MOVING OVER THE
WEST OR NORTHWEST HALF OF THE CWA LATER THIS AFTERNOON AND
CONTINUING THROUGH A GOOD PORTION OF THE NIGHT TONIGHT (ESPECIALLY
THE KEWEENAW TONIGHT). QPF AMOUNTS WILL BE MUCH LIGHTER THAN SEEN
OVER THE LAST COUPLE DAYS AND MAINLY BETWEEN A TRACE AND A COUPLE
TENTHS. IN ADDITION...IT WILL BECOME BREEZY BEHIND THE COLD
FRONT...WITH BUFKIT SOUNDINGS INDICATING GUSTS AROUND 25KTS OVER
MUCH MUCH OF UPPER MICHIGAN TODAY. WITH THE COLD AIR ADVECTION IN
PLACE THROUGH MUCH OF TONIGHT...THOSE GUSTS WILL LIKELY KEEP UP AS
WINDS SHIFT TO THE WEST THROUGH THE NIGHT. WHILE THE KEWEENAW MAY BE
PROTECTED SLIGHTLY TODAY...THE WINDS SHOULD REALLY KICK IN TONIGHT
AS IT IS CLOSEST TO THE TIGHTEST PRESSURE GRADIENT WITH THE
DEPARTING LOW AND RESULTING STRONGER WINDS JUST ABOVE THE SURFACE.
EXPECT THERE TO BE A PERIOD THIS EVENING AND INTO THE EARLY
OVERNIGHT HOURS WHERE GUSTS IN THE KEWEENAW WILL BE BETWEEN
30-35KTS.
FINALLY FOR TEMPERATURES...VALUES THIS MORNING HAVE BEEN CONSISTENT
IN THE 50S OVER THE INTERIOR LOCATIONS...ALTHOUGH LOCATIONS NEAR
THE COOLING OF THE GREAT LAKES HAVE BEEN BOUNCING UP AND DOWN
DEPENDING ON THE WIND DIRECTION. WITH THE WARM START AND THE WARM
FRONT PUSHING NORTHEAST THROUGH MUCH OF UPPER MICHIGAN
TODAY...SHOULD SEE TEMPERATURES RISE INTO THE MID-UPPER 60S OVER
THE CENTRAL/EASTERN CWA AND WHERE SOME SUNSHINE OCCURS WILL
PROBABLY SEE SOME SITES HITTING THE 70 DEGREE MARK. COLDER AIR
ARRIVING BEHIND THE COLD FRONT WILL LEAD TO FALLING TEMPS OVER THE
WEST IN THE AFTERNOON AND THE REST OF THE AREA TOWARDS EVENING. THE
CLOUD COVER TONIGHT WILL KEEP TEMPS A LITTLE ABOVE NORMAL AND HAVE
LOWS IN THE LOWER 40S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 459 AM EDT FRI MAY 9 2014
PATTERN EVOLUTION DURING THE LONG TERM WILL BRING A RETURN OF A
BUILDING RIDGE ALONG/NEAR THE W COAST OF NAMERICA THIS WEEKEND THRU
THE FIRST HALF OF NEXT WEEK (POSITIVE ANOMALIES REACH THEIR MAX
WED). THIS WILL FORCE A FAIRLY DEEP TROF FOR MID MAY TO AMPLIFY
SOUTHWARD INTO THE CNTRL CONUS DURING THE EARLY PART OF NEXT WEEK
WITH SLOW EASTWARD PROGRESSION THEREAFTER. THE BUILDING RIDGE WILL
FORCE THE UPPER LOW/ENERGY NOW IN THE GULF OF ALASKA TO DIVE SE
TOWARD THE SRN ROCKIES. AS THE ENERGY THEN LIFTS NE...ANOTHER ACTIVE
LOW PRES SYSTEM WILL MOVE NE INTO THE UPPER MISSISSIPPI VALLEY ON A
TRACK SIMILAR TO THE SYSTEM CURRENTLY AFFECTING THE MISSISSIPPI
VALLEY/WRN GREAT LAKES. SO...AFTER A PERIOD OF DRY WEATHER EARLY IN
THE WEEKEND...POTENTIAL OF SHRA WILL RETURN...PERHAPS AS EARLY AS
LATE SAT NIGHT/SUN MORNING. DECENT PCPN AMOUNTS MAY THEN BE IN THE
OFFING FOR MON/MON NIGHT AS LOW PRES LIFTS INTO THE UPPER
MISSISSIPPI VALLEY. ONCE THE UPPER TROF REACHES THE WRN GREAT
LAKES...THERE MAY BE A DAY OR 2 OF LIGHT SHOWERY PCPN AT TIMES IN
THE MID WEEK PERIOD (PERHAPS EVEN A LITTLE SNOW MIXED IN). AS FOR
TEMPS...READINGS OVER THE WEEKEND SHOULD BE CLOSE TO NORMAL...
THOUGH IT WILL OBVIOUSLY BE COOL WHERE WINDS ARE ONSHORE NEAR THE
GREAT LAKES. TEMPS WILL BEGIN TO TAKE A DOWNWARD TURN MON/TUE WITH
THE EARLY WEEK LOW PRES SYSTEM...AND TEMPS WED/THU WILL LIKELY BE
QUITE CHILLY/WELL BLO NORMAL FOR MID MAY AS UPPER TROF DRIFTS ACROSS
THE AREA (850MB TEMPS FALL TO PERHAPS AS LOW AS -4 TO -6C). FARTHER
DOWN THE ROAD...PATTERN WILL PROBABALY CONTINUE TO LEAN TOWARD
MAINTAINING OVERALL BLO NORMAL TEMPS OUT TO 10-14 DAYS.
BEGINNING SAT...LOW CLOUDS AND POSSIBLY SOME -SHRA/SPRINKLES/-DZ
WILL LINGER EARLY OVER THE E. OTHERWISE...EXPECT ABUNDANT SUNSHINE
OVER THE W TO SPREAD TO THE ERN FCST AREA BY AFTN AS FCST SOUNDINGS
SHOW A DEEP DRY AIR MASS SPREADING OVER THE AREA. DRY AIR MASS WILL
ALLOW FOR DEEP MIXING. MIXING UPWARDS OF 750MB ON FCST SOUNDINGS
YIELDS MAX TEMPS INTO THE MID TO PERHAPS UPPER 60S IN THE INTERIOR.
TEMPS WILL BE COOLEST ALONG LAKE SUPERIOR IN LOCATIONS WHERE
WESTERLY WINDS HAVE AN OVERLAKE COMPONENT. LAKE BREEZE MAY DEVELOP
NEAR LAKE MICHIGAN IN THE LATTER PART OF THE AFTN. WITH THE DEEP DRY
AIR MASS...RH WILL LIKELY TUMBLE TO AS LOW AS AROUND 20PCT IN THE
INTERIOR...IN PARTICULAR TOWARD THE WI BORDER.
OUT AHEAD OF THE MAIN SYSTEM DIVING TOWARD THE SRN ROCKIES...A LEAD
SHORTWAVE WILL SHIFT FROM THE WRN PLAINS SAT MORNING TO THE UPPER
LAKES SUN MORNING. GIVEN THAT THE SHORTWAVE WILL BE HEADING INTO THE
LARGE SCALE BUILDING UPPER RIDGE DOWNSTREAM OF THE MAIN TROF
AMPLIFYING OVER THE ROCKIES...PCPN ASSOCIATED WITH SHORTWAVE WILL
LIKELY BE DIMINISHING AS IT MOVES INTO THE UPPER LAKES. ANTECEDENT
VERY DRY AIR MASS WILL FURTHER AID THE DIMINISHING OF PCPN SPREADING
INTO THE AREA LATE SAT NIGHT/SUN MORNING. QUESTION WILL BE HOW FAST
DOES THE PCPN DECAY. AT THIS POINT...IT APPEARS THE GFS IS MUCH TOO
AGGRESSIVE WITH WIDESPREAD PCPN IT MOVES ACROSS THE FCST AREA WITH
AS MUCH AS 0.25-0.40 INCHES OVER ROUGHLY THE NW HALF OF UPPER MI.
OTHER GUIDANCE IS DRIER WITH PCPN DRYING UP AS IT MOVES INTO/ACROSS
THE THE FCST AREA. THE NAM IN PARTICULAR HAS ALMOST NO PCPN REACHING
UPPER MI. WILL FAVOR THE DRIER SOLUTIONS GIVEN BUILDING UPPER RIDGE
AND ANTECEDENT DRY AIR MASS. ONLY CHC POPS WILL BE UTILIZED LATE SAT
NIGHT THRU SUN MORNING WITH POPS LOWEST OVER THE NE. CLOUD
COVER/PCPN WILL HAVE AN IMPACT ON HIGH TEMPS SUN. IN FAVORING THE
DRIER SOLUTIONS...WILL ALSO LEAN TOWARD THE WARMER GUIDANCE FOR
HIGHS SUN. AWAY FROM LAKE MODERATION...TEMPS SHOULD REACH WELL INTO
THE 60S TO NEAR 70F.
MAIN SHORTWAVE MOVES OUT ACROSS THE SRN PLAINS MON MORNING AND LIFTS
INTO THE UPPER MISSISSIPPI VALLEY MON NIGHT/TUE ALONG WITH
ASSOCIATED SFC LOW PRES. THERE IS CONSIDERABLE MODEL SPREAD ON
TIMING SYSTEM WITH SOME HINTS OF A SLOWER TREND DEVELOPING. THE
UKMET IS SLOWEST...SHOWING LOW PRES ONLY IN WCNTRL WI AT 00Z WED.
NEXT IS THE GEM...SWINGING FROPA THRU UPPER MI TUE AFTN-TUE NIGHT.
THE ECMWF BRINGS FRONT THRU MON NIGHT/TUE MORNING WHILE THE GFS IS
QUICKEST...PUSHING FRONT ACROSS THE AREA MON EVENING. CONSENSUS OF
RECENT RUNS WILL BE UTILIZED GIVEN SPREAD. AT THIS TIME...BEST
CHANCE OF SHRA SOME TSRA APPEARS TO BE MON/MON NIGHT...BUT IF SLOWER
TREND GAINS MOMENTUM...TIMING WILL NEED TO BE PUSHED BACK A BIT.
AS UPPER TROF DRIFTS ACROSS THE WRN LAKES WED/THU...THERMAL TROF
WITH 850MB TEMPS IN THE -2 TO -6C RANGE WILL YIELD ABUNDANT CLOUD
COVER...ESPECIALLY DURING THE DAYLIGHT HRS. HIGH SUN ANGLE (ONLY 5
1/2 WEEKS TO THE SUMMER SOLSTICE DURING THE MIDDLE OF NEXT WEEK)
WILL PROBABLY SUPPORT AT LEAST SCT -SHRA ACTIVITY...PEAKING IN THE
AFTN HRS. GIVEN THE COLD TEMPS IN THE COLUMN...MAY SEE SOME
GRAUPLE...AND PERHAPS EVEN SOME SNOWFLAKES IF PCPN LINGERS INTO THE
NIGHT. IF WED OR THU ENDS UP MAINLY CLOUDY WITH NMRS -SRHA...HIGH
TEMPS MAY STRUGGLE TO GET INTO THE 50S INLAND WHILE DAYTIME TEMPS
MAY HOLD TO THE MID 30S TO MID 40S NEAR LAKE SUPERIOR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 139 PM EDT FRI MAY 9 2014
LOW PRESSURE TRACKING JUST NE OF UPPER MI WILL BRING A COLD FRONT
WEST TO EAST ACROSS ALL SITES THIS AFTERNOON AND EVENING. ABUNDANT
LOW-LEVEL MOISTURE AND UPSLOPE FLOW SHOULD RESULT IN IFR CIGS AT CMX
AND IWD OVERNIGHT ALONG WITH -SHRA. DOWNSLOPE FLOW WILL LIMIT SAW TO
MVFR CIGS. EXPECT ALL SITES TO BECOME VFR WITH CLEAR SKIES BY SAT
MORNING AS DRY AIR PUSHES ACROSS THE AREA. DECENT MIXING AND
STRONGER WINDS ALOFT WILL BRING GUSTY WINDS TO ALL SITES INTO
SAT...ESPECIALLY FOR CMX...WHERE GUSTS OVER 30KTS WILL BE POSSIBLE
LATE THIS EVENING THROUGH THE OVERNIGHT HOURS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 422 AM EDT FRI MAY 9 2014
A LOW PRESSURE SYSTEM NEAR DULUTH EARLY THIS MORNING WILL SLIDE
NORTHEAST INTO ONTARIO TODAY. AS THIS OCCURS...WINDS WILL SHIFT
AROUND TO THE SOUTHWESTERLY DIRECTION TODAY AND THEN TO THE WEST
TONIGHT. EXPECT THE WINDS TO INCREASE FROM WEST TO EAST TODAY AND
GENERALLY TO 25KTS TONIGHT...ALTHOUGH THERE COULD BE SOME GUSTS
TO 30KTS OVER THE CENTRAL LAKE. THESE STRONGER WINDS...COMBINED WITH
GRADUALLY DRYING LOWER LEVELS SHOULD LEAD TO A DIMINISHMENT OF THE
DENSE FOG OVER LAKE SUPERIOR FROM SOUTHWEST TO NORTHEAST TODAY.
OPTED TO EXTENDED THE DENSE FOG ADVISORY FOR LAKE SUPERIOR INTO THE
AFTERNOON HOURS TO BETTER MATCH UP WITH THE INCREASING WINDS AND
DRIER AIR. A HIGH PRESSURE RIDGE WILL THEN SLIDE OVER THE AREA ON
SATURDAY AND LEAD TO WINDS FALLING BELOW 15KTS SATURDAY NIGHT. THESE
LIGHT WINDS WILL REMAIN THROUGH SUNDAY EVENING. A LOW PRESSURE
SYSTEM MOVING TOWARDS THE UPPER GREAT LAKES REGION FROM THE CENTRAL
PLAINS ON SUNDAY NIGHT WILL LEAD TO INCREASING EASTERLY WINDS (TO
25KTS BY MONDAY EVENING). THEN AS THE LOW SHIFTS NORTHEAST INTO
ONTARIO ON TUESDAY...WINDS WILL SHIFT TO THE SOUTHWEST AND STAY
BELOW 20KTS.
&&
.HYDROLOGY...
ISSUED AT 456 AM EDT FRI MAY 9 2014
THE RAIN SHOWERS AND THUNDERSTORMS PRODUCING HEAVY RAIN HAVE
NEARLY DEPARTED UPPER MICHIGAN EARLY THIS MORNING. BUT THEY HAVE
LEFT RISING RIVER LEVELS IN THEIR WAKE...ESPECIALLY OVER WESTERN
UPPER MICHIGAN WHERE THE HEAVIEST RAIN HAS FALLEN. THE KEWEENAW
PENINSULA HAS SEEN AROUND 0.75 INCHES OVERNIGHT IN ADDITION TO THE
INCH OF RAIN THAT FELL LAST NIGHT. THIS AS LED TO ANOTHER RISE OF
THE TRAP ROCK RIVER OVER THE LAST COUPLE OF HOURS. IT HAS LEVELED
OUT SOMEWHAT OVER THE LAST HOUR...BUT WITH A COUPLE HOURS LEFT
OF RAIN AND SNOW MELT CONTINUING WOULD EXPECT A LITTLE MORE RISE
THIS MORNING. IT DID BRIEFLY REACH 10.15FT...WHICH PUTS THE CURRENT
CREST AT THE 4TH HIGHEST ON RECORD.
WARM TEMPERATURES TODAY WILL CONTINUE THE MELTING FROM A FEW INCHES
OF SNOW WATER EQUIVALENT SHOWN FROM NOHRSC MODEL FROM THE
TIP OF THE KEWEENAW PENINSULA THROUGH PAINESDALE...DONKEN...AND
WINONA. THIS LINES UP WELL WITH THE LATEST SNOW DEPTHS REPORTED AT
PAINESDALE AND HERMAN. WILL SEE HOW THIS SNOW MELT /WARMER FCST
TEMPS FOR THE REST OF THIS WEEK/ IMPACT DOWNSTREAM RIVERS INCLUDING
THE STURGEON RIVER OF BARAGA/HOUGHTON COUNTIES AND THE TRAP ROCK
RIVER. MOST IF NOT ALL OF THE SNOW COULD MELT BY THIS
WEEKEND...BUT IT WILL KEEP THE RIVER LEVELS HIGH INTO EARLY NEXT
WEEK. IN ADDITION...WIDESPREAD RAIN IS EXPECTED AGAIN ON
MONDAY AND THE CURRENT FORECAST CALLS FOR AROUND A HALF AN INCH
OF ACCUMULATION. THOSE LIVING AROUND RIVERS...CREEKS...AND STREAMS
SHOULD CONTINUE TO MONITOR RIVER LEVELS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 5 PM EDT /4 PM CDT/ THIS AFTERNOON FOR
LSZ162-240>251-263>267.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 6 PM EDT THIS EVENING FOR LMZ248-250.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...KLUBER
MARINE...SRF
HYDROLOGY...SRF
AREA FORECAST DISCUSSION
NWS DULUTH MN
1248 PM CDT FRI MAY 9 2014
.UPDATE...
ISSUED AT CDT FRI MAY 9 2014
THE FOCUS FOR THIS UPDATE WAS THE DENSE FOG OVER WESTERN LAKE
SUPERIOR AND AREAS ALONG THE NORTH AND SOUTH SHORE...AS WELL AS
THE RAIN SHOWERS FOR TODAY AND THIS EVENING.
THE MODELS ARE SUGGESTING THE FOG WILL LINGER ALONG THE NORTH
SHORE LONGEST...PROBABLY TILL MID AFTERNOON...SO I EXTENDED THE
DENSE FOG ADVISORY FOR THE NORTH SHORE UNTIL 3 PM. THE HRRR SEEMED
TO BE DOING FAIRLY WELL WITH THE CURRENT COVERAGE OF DENSE
FOG...SO I LEANED ON THE HRRR FOR THE AFTERNOON FORECAST. THE FOG
NEAR THE TWIN PORTS SHOULD BEGIN TO LIFT VERY LATE THIS
MORNING...SO I ONLY EXTENDED THAT PART OF THE ADVISORY TILL NOON.
THE NORTHWEST WINDS DEVELOPING BEHIND THE PASSING LOW PRESSURE
SYSTEM WILL ALSO BE HELPING TO DISSIPATE THE FOG.
WE MAY HAVE HAD PCPN ENDING TOO QUICKLY...AND DID NOT HAVE HIGH
ENOUGH PCPN CHANCES ACROSS THE NORTHERN FORECAST AREA. THE MODELS
ARE IN GOOD AGREEMENT WITH THE PCPN LINGERING LONGER THAN THE
PREVIOUS FORECAST...SO I DELAYED ITS DISSIPATION AND/OR EXIT FROM
THE FORECAST AREA THROUGH THIS EVENING.
UPDATE ISSUED AT 620 AM CDT FRI MAY 9 2014
UPDATED FOR AVIATION DISCUSSION.
&&
.SYNOPSIS...
ISSUED AT 354 AM CDT FRI MAY 9 2014
SURFACE LOW CURRENTLY JUST NORTHEAST OF KSTL IS GRADUALLY MOVING
NORTHEAST...WITH SOME FAIRLY STRONG PRESSURE FALLS AND AN INVERTED
TROUGH OVER THE ARROWHEAD THIS MORNING. EXTENDING FROM CENTRAL
WISCONSIN UP OVER WESTERN UPPER MICHIGAN AND LAKE SUPERIOR IS A BAND
OF SHOWERS AND THUNDERSTORMS THAT MOVED OVER THE FORECAST AREA
OVERNIGHT. OVER WESTERN MINNESOTA...EASTERN NORTH AND SOUTH DAKOTA
IS AN AREA OF RAIN SHOWERS IN THE WRAP AROUND PORTION OF THE
STORM...ACCOMPANIED BY A NICE PV ANOMALY INDICATIVE OF A TROWAL.
THE SURFACE WARM FRONT EXTENDS EAST FROM THE SURFACE LOW ALONG THE
DEWPOINT DISCONTINUITY OVER NORTHERN WISCONSIN AND INTO UPPER
MICHIGAN. THE COLD FRONT EXTENDS SOUTH FROM THE LOW...AND IS
PLOWING EAST ACROSS IOWA AND MISSOURI. IN THE CONVERGENT AREA AHEAD
OF THE SURFACE LOW WHERE WINDS ARE LIGHT AND DEWPOINT DEPRESSIONS
ARE LOW...AREAS OF FOG HAVE DEVELOPED. IT SEEMS MOST WIDESPREAD
WHERE SOME OF THE COOLER MARINE LAYER HAS SLOPPED ASHORE IN THE
LIGHT NORTHEAST FLOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT FRI MAY 9 2014
THE SURFACE LOW WILL CONTINUE TO MOVE NORTHEAST TODAY...EXITING
TO CENTRAL ONTARIO BY 18Z TODAY. THE AREAS OF DENSE FOG MENTIONED
ABOVE HAVE BEEN PERSISTENT MOST OF THE NIGHT AHEAD OF THE
LOW...AND HAVE DECIDED TO ISSUE A DENSE FOG FOR THE NORTH SHORE
AND AREAS AROUND THE HEAD OF THE LAKE UNTIL MID MORNING. AS THE
SURFACE LOW MOVES ACROSS THE AREA THE WIND DIRECTION WILL TURN
AROUND TO THE NORTHWEST...SOME DRIER AIR WILL BEGIN TO WORK INTO
THE AREA EVEN IF TEMPERATURES DONT CHANGE MUCH...SO EXPECT THE FOG
TO DISSIPATE BY MID MORNING.
THE SHOWERS THIS MORNING OVER THE FAR NORTHEASTERN CWA SHOULD MOVE OFF
TO THE EAST...LEAVING THAT PART OF THE FORECAST AREA MOSTLY DRY.
THE AREA OF SHOWERS ASSOCIATED WITH THE TROWAL ARE GOING TO SWEEP
ACROSS THE FORECAST AREA TODAY AND EARLY THIS EVENING...MAINLY
OVER NORTHERN MINNESOTA. AM FAIRLY CONFIDENT IN THIS AREA OF
PRECIPITATION...SO HAVE RAISED POPS SOMEWHAT AND REFINED TIMING
SOMEWHAT. UNDER THIS AREA OF SHOWERS TEMPERATURES ARE GOING TO
ONLY GET INTO THE UPPER 40S TO AROUND 50...WITH HIGHS IN THE MID
TO UPPER 50S MOST OTHER LOCATIONS. TEMPERATURES EARLY THIS MORNING
ARE IN THE UPPER 50S TO LOWER 60S OVER PORTIONS OF NORTHWEST
WISCONSIN WHERE THEY ARE IN THE WARM SECTOR. EXPECT THAT THEY ARE
AT OR NEAR THEIR HIGHS FOR TODAY...AND WILL ONLY REMAIN STEADY OR
SLOWLY FALL THE REST OF THE DAY. TONIGHT THE SHOWERS WILL STILL BE
AFFECTING THE ARROWHEAD REGION IN THE EVENING...BUT A THERE WILL
BE A GRADUAL CLEARING TREND SETTING UP FROM SOUTHWEST TO NORTHEAST
AS THE STORM GRADUALLY MOVES OFF TO THE NORTHEAST TONIGHT. EXPECT
TEMPERATURES TO FALL OFF INTO THE MID 30S MOST LOCATIONS...AS I
EXPECT CLEARING TO OCCUR FOR NEARLY THE WHOLE CWA BY EARLY
MORNING. WINDS WILL DROP OFF ENOUGH FOR RADIATIONAL COOLING TO BE
FAIRLY SIGNIFICANT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 354 AM CDT FRI MAY 9 2014
A NARROW RIDGE OF HIGH PRESSURE ALOFT AND AT THE SURFACE WILL BUILD
IN SAT MORNING WITH DRY CONDITIONS AND MOSTLY SUNNY SKIES THROUGH
MOST OF THE DAY. A WEAK UPPER S/W AND ASSOCIATED SFC TROUGH WILL
LIFT E/NEWD FROM THE DAKOTAS INTO MN AND WRN LAKE SUPERIOR LATER IN
THE DAY SATURDAY AND ESPECIALLY SAT NIGHT. THIS SYSTEM WILL PRODUCE
ANOTHER ROUND OF WIDESPREAD RAIN SHOWERS AND A FEW WEAK
THUNDERSTORMS. THE SFC BOUNDARY WILL STALL OUT AS IT LIFTS NWD INTO
NRN MN AND AWAIT THE NEXT SURGE OF WARM MOIST AIR LATE IN THE
WEEKEND...ALONG WITH THE NEXT LOW PRESSURE SYSTEM EXPECTED TO TRACK
SW TO NE OVER THE UPPER MIDWEST MON INTO TUE MORNING. THIS SYSTEM
WILL ONCE AGAIN BE LOADED WITH MOISTURE AND ALSO DRAW UP A SLIGHTLY
UNSTABLE AIR MASS TO PRODUCE ISOLATED THUNDERSTORMS AND THE
POTENTIAL FOR LOCALLY HEAVY RAINFALL. AS THE SFC LOW APPROACHES FROM
THE SW...PRESSURE FALLS WILL INDUCE A STRONG NE FLOW OFF LAKE
SUPERIOR AND COMBINE WITH FAIRLY STRONG WAA IN THE MID/LOW LVLS TO
PRODUCE ANOTHER PERIOD OF COOL/CLOUDY/FOGGY CONDITIONS AROUND THE
PERIPHERY OF THE LAKE. THE PRESENCE OF THIS COOL/STABLE NEAR-SFC
LAYER WILL KEEP ANY STORMS ELEVATED THAT TRACK TO THE
NORTH...KEEPING THE THREAT OF STRONG/SEVERE WX ON THE LOW SIDE. AN
UNSEASONABLY COLD AIR MASS WILL ADVECT IN ON THE BACK SIDE OF THIS
SYSTEM AS IT DEPARTS TO THE EAST LATE TUE AND WED. THE AIR PUSHING
IN FROM THE NW COULD BE COLD ENOUGH TO ALLOW FOR A FEW LIGHT SNOW
SHOWERS TO MIX IN LATE TUE NIGHT...AND AGAIN LATE WED NIGHT. 850MB
TEMPS WILL BE ROUGHLY -5 TO -10 DEG C. YES IT IS ALMOST THE MIDDLE
OF MAY. WILL SEE SLIGHT IMPROVEMENT INTO THURSDAY AS HIGH PRESSURE
GRADUALLY BUILDS IN ACROSS THE MIDWEST. HOWEVER IT WILL NOT BE UNTIL
THE WEEKEND UNTIL TEMPS REACH BACK TO NEAR NORMAL.
TEMPERATURES THIS WEEKEND WILL BE AT OR SLIGHTLY ABOVE NORMAL WITH
LIGHT AND VARIABLE WINDS. SATURDAY WILL LIKELY BE THE MOST PLEASANT
DAY WITH DRY CONDITIONS EXPECTED. THE TEMP TREND WILL BEGIN A
DOWNWARD SLIDE MON THROUGH WED WITH HIGHS IN THE 40S AND 50S AND
OVERNIGHT LOWS IN THE 30S. A GRADUAL WARMING TREND WILL NOT BE FELT
UNTIL THE LATTER HALF OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1248 PM CDT FRI MAY 9 2014
A MIX OF IFR/LOW END MVFR CONDITIONS COVERED THE NORTHLAND THIS
AFTERNOON. AREAS OF LIGHT RAIN OR DRIZZLE WERE ALSO OCCURRING. THE
AREA OF LOW PRESSURE THAT HAS IMPACTED THE REGION FOR THE PAST
COUPLE DAYS WILL CONTINUE TO MOVE OFF...AND CONDITIONS WILL
GRADUALLY IMPROVE FROM WEST TO EAST. CEILINGS WILL CLEAR FROM WEST
TO EAST LATE THIS AFTERNOON INTO THE LATE EVENING HOURS. GUSTY
WEST TO NORTHWEST WINDS WILL DEVELOP...THEN DIMINISH THIS EVENING
AS THE GRADIENT WEAKENS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 51 38 63 48 / 60 40 10 60
INL 50 34 67 44 / 80 40 0 50
BRD 55 36 64 46 / 70 10 40 50
HYR 57 38 67 47 / 70 30 10 60
ASX 59 38 64 45 / 40 40 0 60
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 3 PM CDT THIS AFTERNOON FOR MNZ020-021.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 AM CDT SATURDAY FOR LSZ143>147.
DENSE FOG ADVISORY UNTIL 4 PM CDT THIS AFTERNOON FOR LSZ140-141.
&&
$$
UPDATE...GROCHOCINSKI
SYNOPSIS...LE
SHORT TERM...LE
LONG TERM...BJT
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1215 PM CDT FRI MAY 9 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT FRI MAY 9 2014
RAP ANALYZED SURFACE LOW JUST SOUTH OF DULUTH EARLY THIS MORNING.
AREAS WEST OF THE METRO HAVE SEEN THE WINDS TURN WESTERLY AND PICK
UP IN INTENSITY. COLD AIR ADVECTION IS ONGOING IN THESE AREAS...AND
WILL CONTINUE TO SPREAD ACROSS THE REMAINDER OF THE FORECAST AREA
TODAY. THE SURFACE LOW WILL SLOWLY CONTINUE NORTHEASTWARD...AS THE
WESTERLY WINDS TAKE MUCH OF THE DAY TO SPREAD ACROSS WEST CENTRAL
WISCONSIN. ABUNDANT LOW LEVEL MOISTURE WILL ALLOW FOR LOW LCL
HEIGHTS WHICH IS CURRENTLY NOTICEABLE IN THE OBSERVATIONS BEHIND THE
COLD FRONT WHERE CEILINGS UNDER 1K FEET ARE PRESENT. RAP AND NAM
MODEL SOUNDINGS INDICATE THIS MOISTURE STICKING AROUND FOR MUCH OF
THE DAY...SO TRENDED TOWARD A MORE PESSIMISTIC SKY COVER FORECAST
AND HENCE LOWERED MAX TEMPERATURES TODAY BY A FEW DEGREES ACROSS THE
FA. MAX TEMPS WILL BE ABOUT 10 DEGREES BELOW SEASONAL NORMALS FOR
THIS TIME OF YEAR. IN ADDITION...WRAP AROUND LIGHT RAIN SHOWERS ARE
EXPECTED TO MOVE ACROSS THE NORTHERN PORTION OF THE CWA AS THEY
CYCLONIC CIRCULATION ALOFT REMAINS BETTER TOWARD THE NORTH /AS WELL
AS AT LEAST SOME FGEN AND FN VECTOR CONVERGENCE/. SKIES WILL BEGIN
CLEARING LATE THIS AFTERNOON AND MOSTLY CLEAR SKIES ARE EXPECTED
OVERNIGHT...EXCEPT CLOUDS WILL QUICKLY BEGIN FILLING IN FROM THE
SOUTHWEST EARLY SATURDAY MORNING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 340 AM CDT FRI MAY 9 2014
AN UNSETTLED PERIOD REMAINS FORECAST FOR MUCH OF THE LONGER TERM
AS NORTHERN AND SOUTHERN STREAM ENERGY EVENTUALLY PHASE OVER THE
CENTER OF THE COUNTRY AROUND THE MIDDLE OF NEXT WEEK. THIS PROCESS
OCCURS THE FASTEST WITH THE GFS WHILE DP/DT SHOWS THAT THE SLOWER
ECMWF IS BECOMING EVEN SLOWER WITH TIME.
ON SATURDAY...A WAVE MOVING IN FROM THE CENTRAL PLAINS WILL BRING
THICKENING CLOUDINESS AND SHOWERS BACK ACROSS THE FA FROM SW TO NE
DURING THE DAY. A BRIEF BREAK IN THE PRECIPITATION IS EXPECTED
SATURDAY NIGHT BEFORE A MORE POTENT WAVE BEGINS TO TAKE SHAPE OVER
THE CENTRAL PLAINS ON SUNDAY. THIS WAVE IS BEING DRIVEN BY THE
SOUTHERN STREAM ENERGY. USING THE SLOWER ECWMF...THE LOW IN THE
PLAINS TAKES UNTIL MONDAY EVENING TO ARRIVE IN SE MN. THIS PLACES
MUCH OF THE FA IN LOW LEVEL THETA-E ADVECTION FROM SUNDAY THROUGH
MONDAY...WITH SOUTHERN MN BEARING THE BRUNT OF IT. HENCE...LIKELY
POPS STREAM BACK IN ON SUNDAY FROM THE SOUTHWEST AND PERSIST THROUGH
MONDAY. WIDESPREAD HALF INCH TO ONE INCH RAINFALL IS LIKELY DURING
THIS PERIOD WITH SOME TWO INCH AMOUNTS OVER SOUTHERN MN. THERE WILL
CERTAINLY BE THE THREAT FOR SOME THUNDERSTORMS...ESPECIALLY ON
MONDAY FROM THE TWIN CITIES ON EAST AND SOUTH. STRICTLY USING THE
ECMWF TIMING WOULD INDICATE A WINDOW OF OPPORTUNITY FOR STRONG TO
SEVERE STORMS MONDAY AFTERNOON/EVENING TO THE SOUTH AND EAST OF
THE TWIN CITIES.
THE SHOWERS WILL BEGIN TO TAPER OFF MONDAY NIGHT AS THE LOW
PRESSURE SYSTEM MOVES NORTHEAST OF THE FA. INSTABILITY SHOWERS ARE
POSSIBLE MAINLY FROM CENTRAL MINNESOTA ON NORTHWARD ON TUESDAY.
SCATTERED SHOWERS ARE BACK FOR MUCH OF THE FA WEDNESDAY AND
THURSDAY AS THE UPPER TROUGH COMES TOGETHER FROM THE UPPER
MISSISSIPPI VALLEY TO THE GULF COAST. HIGH TEMPERATURES WILL BE
CLOSE TO NORMAL THIS WEEKEND...BUT THEN RETREAT TO SOME 10 TO 15
DEGREES BELOW NORMAL FOR THE MIDDLE TO END OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1204 PM CDT FRI MAY 9 2014
MVFR CIGS REMAIN OVER PARTS MUCH OF THE CENTRAL AND EAST INTO THE
AFTERNOON. GRADUALLY BECOMING VFR AND SKC FROM WEST TO EAST AS THE
UPPER TROUGH MOVES EAST. SOME CHANCE OF -SHRA OVER THE NORTHEAST
CWA INTO THE AFTERNOON AS WELL. EXPECT WEST TO NORTHWEST WINDS
13-17KTS WITH GUSTS TO 25-29KTS OVER THE AREA INTO THE
AFTERNOON...BEFORE DIMINISHING FROM WEST TO EAST BY EVENING.
LIGHTER WINDS OVERNIGHT AS SURFACE HIGH MOVES THROUGH....BECOMING
SOUTHEAST INTO SATURDAY AND INCREASING AHEAD OF NEXT TROUGH. SHOULD
SEE SOME MID/HIGH LEVEL CLOUDS INCREASE AGAIN OVER THE WESTERN
AREA LATER TONIGHT AND SATURDAY MORNING...BUT REMAINING VFR. COULD
SEE SOME -SHRA MOVE IN TOWARDS KRWF 15Z-18Z BUT CONFIDENCE IS LOW
ON HOW FAST MOISTURE WILL RETURN AND SATURATE. KEPT IT DRY FOR
NOW.
KMSP...CIGS LIFTING TO MVFR LATE AFTERNOON. CLEARING BY EARLY
EVENING AS UPPER TROUGH EXITS EAST. SURFACE HIGH MOVES OVER THE
AREA TONIGHT WITH LIGHT WINDS BECOMING SOUTHEAST AND INCREASING
SATURDAY MORNING. MID/HIGH LEVEL CLOUDS SPREAD EAST SATURDAY
MORNING WITH SOME CHANCE OF -SHRA IN THE AFTERNOON. LEFT IT AS
VCSH FOR NOW...AS SOUTHEAST FLOW WILL BE DRY INITIALLY.
/OUTLOOK FOR KMSP/
SAT NITE...VFR. CHC -SHRA/-TSRA. WINDS SSE 10KTS.
SUN...MVFR POSSIBLE. LIKELY -SHRA. WINDS SW TO NW 10-15 KTS.
MON...MVFR POSSIBLE. LIKELY -SHRA. WINDS NW 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...SPD
LONG TERM...RAH
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS HASTINGS NE
554 PM CDT FRI MAY 9 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 252 PM CDT FRI MAY 9 2014
MAIN FORECAST CONCERNS WILL BE CHANCE FOR SPRINKLES AND LATE TONIGHT
AND INTO SATURDAY MORNING AND TEMPERATURES THROUGH THE PERIOD.
A WEAK SURFACE HIGH PRESSURE SYSTEM IS DRIFTING THROUGH THE CENTRAL
PLAINS TODAY. THIS HAS KEPT SKIES MOSTLY CLEAR AND WINDS FAIRLY
LIGHT AND VARIABLE.
THE SURFACE HIGH IS EXPECTED TO SLIDE TO THE SOUTHEAST LATE THIS
AFTERNOON AND THIS EVENING. WINDS WILL CONTINUE TO TURN TO THE
SOUTHWEST OR WEST THROUGH THE EVENING HOURS. AN UPPER LEVEL WAVE
WILL MOVE INTO THE AREA TONIGHT. SO FAR THE LOWER LAYERS ARE FAIRLY
DRY...BUT BOTH THE GFS AND NAM BRING IN SOME SPOTTY PRECIPITATION
TONIGHT AND THE HRRR AND WRF ALSO HINT AS SOMETHING VERY SPOTTY
ACROSS THE AREA. WITH THE DRY LOWER LEVELS HAVE KEPT A FEW SPRINKLES
MAINLY IN THE NORTHERN PART OF THE FORECAST AREA BECAUSE CONFIDENCE
IS LOW THERE WOULD BE ANYTHING MEASURABLE. A WEAK COLD FRONT WILL
MOVE INTO THE AREA LATE TONIGHT...MOVING THROUGH THE AREA SATURDAY
MORNING. FOR A FEW HOURS BEHIND THE FRONT THERE WILL BE A LITTLE
BREEZIER CONDITIONS...BUT BEFORE MID AFTERNOON THE WINDS START TO
DIMINISH A LITTLE. EVEN BEHIND THE COLD FRONT THE TEMPERATURES ON
SATURDAY WILL BE FAIRLY WARM.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 252 PM CDT FRI MAY 9 2014
GUIDANCE FROM THE NAM...OPERATIONAL GFS AND EC ALL SUGGEST QUASI-
ZONAL UPPER TROPOSPHERIC FLOW WILL EXIST ACROSS MUCH OF THE CONUS AT
00Z SUNDAY...ALTHOUGH A STRENGTHENING UPPER TROPOSPHERIC SHORT WAVE
OVER THE SOUTHWESTERN CONUS WILL BEGIN TURNING THE FLOW OVER OUR
AREA MORE SOUTHWESTERLY BY 12Z SUNDAY. EVENTUALLY AN UPPER
TROPOSPHERIC LONGWAVE TROUGH AXIS IS EXPECTED TO DEVELOP FROM SOUTH
CENTRAL CANADA INTO THE SOUTHWESTERN CONUS BY 00Z MONDAY...WITH THE
TROUGH AXIS EXPECTED TO MOVE EAST ACROSS ACROSS OUR AREA MONDAY
NIGHT INTO TUESDAY...RESULTING IN NORTHWESTERLY UPPER TROPOSPHERIC
FLOW OVER OUR AREA TUESDAY NIGHT ONWARD. AT THE SURFACE AN AREA OF
LOW BAROMETRIC PRESSURE IS EXPECTED ACROSS WESTERN KANSAS AND
EASTERN COLORADO AT 00Z SUNDAY. THIS SURFACE LOW IS EXPECTED TO MOVE
NORTHEAST...LIKELY NEARING NORTHEAST KANSAS BY 00Z MONDAY AND THE
UPPER MISSISSIPPI VALLEY BY 00Z TUESDAY. SO ALTHOUGH THE LOWER
TROPOSPHERIC FLOW ACROSS OUR AREA WILL START THE LONG TERM FORECAST
PERIOD FROM THE EAST/SOUTHEAST...A TRANSITION TO THE NORTHEAST IS
EXPECTED ACROSS MUCH OF THE AREA DURING THE DAY SUNDAY...AND TO
THE NORTHWEST SUNDAY NIGHT THROUGH MUCH OF THE REST OF THE LONG
TERM FORECAST PERIOD.
THE NAM...OPERATIONAL GFS AND EC ALL SUGGEST A 50-60KT JET STREAK
JUST ABOVE THE BOUNDARY LAYER WILL PROMOTE ENOUGH THERMAL ADVECTION
FOR PRECIPITATION PRODUCTION ACROSS MUCH OF THE CWA SATURDAY NIGHT
...ESPECIALLY ACROSS EASTERN PORTIONS OF THE CWA WHERE THERMAL
ADVECTION...AS WELL AS MOISTURE CONVERGENCE...WILL BE ENHANCED.
GIVEN THIS...WENT AHEAD WITH 20-70% POPS ACROSS MUCH OF THE CWA
SATURDAY NIGHT...WITH THE HIGHEST POPS RELEGATED ACROSS OUR EAST. AT
THIS TIME ANY CONVECTION THAT IS REALIZED SATURDAY NIGHT IS EXPECTED
TO REMAIN WEAK.
ANY OVERNIGHT CONVECTION SHOULD DEPART TO THE EAST/NORTHEAST BY
DAYBREAK SUNDAY AS THE LOWER TROPOSPHERIC JET STREAK ALSO SHIFTS TO
THE EAST. THIS MAY ALLOW FOR A BREAK IN PRECIPITATION AT SOME POINT
SUNDAY MORNING...BUT POPS STILL REMAIN INTACT FOR THE ENTIRE CWA ON
SUNDAY AS THERMAL ADVECTION AHEAD OF THE APPROACHING UPPER
TROPOSPHERIC TROUGH INCREASES. AS THE AFOREMENTIONED SURFACE LOW
MOVES INTO NORTHEASTERN KANSAS SUNDAY AFTERNOON AND EVENING...AN
ASSOCIATED LOWER TROPOSPHERIC BAROCLINIC ZONE IS EXPECTED TO BACK
NORTHWEST AS A WARM FRONT...PERHAPS PUSHING INTO OUR EXTREME
EAST/SOUTHEASTERN CWA. LOWER TROPOSPHERIC CONVERGENCE AND RESULTANT
LIFT ALONG THIS BAROCLINIC ZONE...ALONG WITH INCREASING SYNOPTIC-
SCALE OMEGA DUE TO INCREASING UPPER TROPOSPHERIC THERMAL ADVECTION
AHEAD OF THE APPROACHING TROUGH...APPEARS AS THOUGH THEY WILL BE
SUFFICIENT FOR CONVECTIVE INITIATION SUNDAY AFTERNOON AND EVENING.
SOME OF THIS CONVECTION COULD CERTAINLY BE REALIZED OVER OUR
EAST/SOUTHEAST SUNDAY AFTERNOON AND EVENING. THE BAROCLINIC ZONE
SHOULD QUICKLY DEPART OUR AREA TO THE EAST/SOUTHEAST SUNDAY EVENING
AS THE SURFACE LOW MOVES NORTHEAST...THUS ALLOWING A MUCH COOLER AND
DRIER LOWER TROPOSPHERIC AIR MASS INTO THE AREA. THIS WILL RESULT IN
RAPIDLY DECREASING POTENTIAL INSTABILITY THUS ELIMINATING ANY CHANCE
OF DEEP CONVECTION ACROSS OUR AREA. THAT BEING SAID...CONTINUED
THERMAL ADVECTION AHEAD OF THE APPROACHING TROUGH APPEARS IT WILL
STILL BE SUFFICIENT FOR PRECIPITATION PRODUCTION HEADING INTO THE
REMAINDER OF SUNDAY NIGHT AND EVEN MONDAY. AS A RESULT...POPS REMAIN
INTACT ACROSS MUCH OF THE CWA SUNDAY NIGHT INTO MONDAY. BY MONDAY
NIGHT...UPPER TROPOSPHERIC THERMAL ADVECTION SHOULD DIMINISH AS THE
TROUGH AXIS BEGINS CLEARING THE AREA. DRY CONDITIONS ARE CURRENTLY
FORECAST MONDAY NIGHT THROUGH WEDNESDAY AS A RESULT. WEDNESDAY NIGHT
INTO THURSDAY...THERE ARE INDICATIONS FROM THE OPERATIONAL GFS...AND
TO A LESSER EXTENT THE NAM...OF A WEAK UPPER TROPOSPHERIC
PERTURBATION MOVING ACROSS THE REGION AND PERHAPS PROVIDING A PERIOD
OF LIGHT PRECIPITATION. CONFIDENCE REGARDING THIS FEATURE IS NOT
HIGH...BUT ALLBLEND PRESENTED A ~20% POP TO OUR NORTH/NORTHEAST
WEDNESDAY NIGHT INTO THURSDAY AND OPTED TO KEEP THIS POP AS IS.
GUIDANCE SUGGESTS DEW POINT READINGS WELL INTO THE 60S WILL
INFILTRATE MUCH OF EASTERN KANSAS SUNDAY AFTERNOON ON THE WARM SIDE
OF THE BAROCLINIC ZONE. THE MOISTURE CONTENT OF THE LOWER
TROPOSPHERIC AIR MASS IS NOT EXPECTED TO BE NEARLY AS ROBUST FARTHER
NORTHWEST INTO OUR AREA...BUT AGAIN IF THE BAROCLINIC ZONE CAN SNEAK
INTO OUR EAST/SOUTHEAST SUNDAY AFTERNOON AND EVENING...THEN
POTENTIAL INSTABILITY VALUES COULD CERTAINLY CLIMB INTO THE 1000-
2000J/KG RANGE. DEEP LAYER BULK SHEAR VALUES ON THE ORDER OF ~50KTS
ARE ALSO FORECAST ACROSS OUR EAST/SOUTHEAST SUNDAY AFTERNOON AND
EVENING. SO...ALTHOUGH IT APPEARS THE BULK OF THE SEVERE WEATHER
SHOULD REMAIN SOUTH AND EAST OF OUR CWA...IT STILL APPEARS THERE
WILL BE A BRIEF WINDOW OF OPPORTUNITY FOR STRONG THUNDERSTORM
ACTIVITY ACROSS PORTIONS OF OUR CWA...GENERALLY ALONG AND SOUTHEAST
OF A LINE FROM ALMA TO YORK. A THREAT FOR SEVERE WEATHER WILL RESIDE
FARTHER SOUTHEAST...GENERALLY ALONG AND SOUTHEAST OF A LINE FROM
BELOIT TO HEBRON. WILL GO AHEAD AND MENTION THESE THREATS IN THE HWO
FOR SUNDAY.
GUIDANCE ALSO SUGGESTS LOWER TROPOSPHERIC PRESSURE RISES POST-FROPA
COULD PROVIDE A STRONG LOWER TROPOSPHERIC WIND FIELD ACROSS
NORTHWESTERN PORTIONS OF THE CWA SUNDAY AFTERNOON INTO SUNDAY
EVENING. GUIDANCE SUGGESTS A SUSTAINED WIND OF 25-30KTS WITH LOCALLY
HIGHER GUSTS WILL BE REALIZED AND AS A RESULT...WILL MENTION SUCH
CONDITIONS IN THE HWO.
A COOLER LOWER TROPOSPHERIC AIR MASS WILL INFILTRATE THE AREA
FOLLOWING THE PASSAGE OF THE BAROCLINIC ZONE SUNDAY...WITH HIGHS
GENERALLY IN THE 50 ON MONDAY AND IN THE 60S TUESDAY THROUGH FRIDAY.
OVERNIGHT LOWS IN THE 40S ARE FORECAST FOR THE MOST PART THROUGH THE
LONG TERM FORECAST PERIOD.
&&
.AVIATION...(FOR THE 00Z KGRI TAF THROUGH 00Z SATURDAY EVENING)
ISSUED AT 545 PM CDT FRI MAY 9 2014
WIND SHOULD QUICKLY DIMINISH BY THE TIME OF THE BEGINNING OF THE
FORECAST. ONLY HIGH LEVEL CIRRUS IS EXPECTED. HOWEVER...THERE IS A
VERY OUTSIDE SHOT AT A RANDOM THUNDERSHOWER DEVELOPING AROUND
12Z...BUT THIS WOULD BE A BIT MORE LIKELY FARTHER TO THE EAST.
MODELS INDICATE A POTENTIAL BRUSH WITH LOW-LEVEL WIND SHEAR ISSUES
NEAR 06Z...BUT THIS APPEARS TO BE JUST LOW ENOUGH NOT TO INCLUDE
IN THIS FORECAST. WIND SPEED WILL ONCE AGAIN KICK UP BY AFTERNOON
SATURDAY WITH INCREASED LOW-LEVEL LAPSE RATES.
&&
.FIRE WEATHER...
ISSUED AT 252 PM CDT FRI MAY 9 2014
RELATIVE HUMIDITY LEVELS ARE EXPECTED TO DROP BELOW 25 PERCENT FOR
NORTH CENTRAL KANSAS AND FAR SOUTHERN SOUTH CENTRAL NEBRASKA FOR
SATURDAY AFTERNOON. DURING THE MORNING THE WINDS WILL BE WEST OR
NORTHWEST AT 15 TO 20 MPH WITH GUSTS TO AROUND 25 MPH...BUT BY
AFTERNOON...WHEN THE RELATIVE HUMIDITY WILL BE THE LOWEST...THE
WINDS WILL HAVE DIMINISHED TO 10 TO 15 MPH WITH GUSTS TO 20 MPH.
EXPECT THERE TO ONLY BE A SMALL TIME FRAME WHERE NEAR CRITICAL FIRE
DANGER IS EVEN CLOSE. WILL LEAVE IT OUT OF THE HWO AT THIS TIME.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BRYANT
AVIATION...HEINLEIN
FIRE WEATHER...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
320 PM CDT FRI MAY 9 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 252 PM CDT FRI MAY 9 2014
MAIN FORECAST CONCERNS WILL BE CHANCE FOR SPRINKLES AND LATE TONIGHT
AND INTO SATURDAY MORNING AND TEMPERATURES THROUGH THE PERIOD.
A WEAK SURFACE HIGH PRESSURE SYSTEM IS DRIFTING THROUGH THE CENTRAL
PLAINS TODAY. THIS HAS KEPT SKIES MOSTLY CLEAR AND WINDS FAIRLY
LIGHT AND VARIABLE.
THE SURFACE HIGH IS EXPECTED TO SLIDE TO THE SOUTHEAST LATE THIS
AFTERNOON AND THIS EVENING. WINDS WILL CONTINUE TO TURN TO THE
SOUTHWEST OR WEST THROUGH THE EVENING HOURS. AN UPPER LEVEL WAVE
WILL MOVE INTO THE AREA TONIGHT. SO FAR THE LOWER LAYERS ARE FAIRLY
DRY...BUT BOTH THE GFS AND NAM BRING IN SOME SPOTTY PRECIPITATION
TONIGHT AND THE HRRR AND WRF ALSO HINT AS SOMETHING VERY SPOTTY
ACROSS THE AREA. WITH THE DRY LOWER LEVELS HAVE KEPT A FEW SPRINKLES
MAINLY IN THE NORTHERN PART OF THE FORECAST AREA BECAUSE CONFIDENCE
IS LOW THERE WOULD BE ANYTHING MEASURABLE. A WEAK COLD FRONT WILL
MOVE INTO THE AREA LATE TONIGHT...MOVING THROUGH THE AREA SATURDAY
MORNING. FOR A FEW HOURS BEHIND THE FRONT THERE WILL BE A LITTLE
BREEZIER CONDITIONS...BUT BEFORE MID AFTERNOON THE WINDS START TO
DIMINISH A LITTLE. EVEN BEHIND THE COLD FRONT THE TEMPERATURES ON
SATURDAY WILL BE FAIRLY WARM.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 252 PM CDT FRI MAY 9 2014
GUIDANCE FROM THE NAM...OPERATIONAL GFS AND EC ALL SUGGEST QUASI-
ZONAL UPPER TROPOSPHERIC FLOW WILL EXIST ACROSS MUCH OF THE CONUS AT
00Z SUNDAY...ALTHOUGH A STRENGTHENING UPPER TROPOSPHERIC SHORT WAVE
OVER THE SOUTHWESTERN CONUS WILL BEGIN TURNING THE FLOW OVER OUR
AREA MORE SOUTHWESTERLY BY 12Z SUNDAY. EVENTUALLY AN UPPER
TROPOSPHERIC LONGWAVE TROUGH AXIS IS EXPECTED TO DEVELOP FROM SOUTH
CENTRAL CANADA INTO THE SOUTHWESTERN CONUS BY 00Z MONDAY...WITH THE
TROUGH AXIS EXPECTED TO MOVE EAST ACROSS ACROSS OUR AREA MONDAY
NIGHT INTO TUESDAY...RESULTING IN NORTHWESTERLY UPPER TROPOSPHERIC
FLOW OVER OUR AREA TUESDAY NIGHT ONWARD. AT THE SURFACE AN AREA OF
LOW BAROMETRIC PRESSURE IS EXPECTED ACROSS WESTERN KANSAS AND
EASTERN COLORADO AT 00Z SUNDAY. THIS SURFACE LOW IS EXPECTED TO MOVE
NORTHEAST...LIKELY NEARING NORTHEAST KANSAS BY 00Z MONDAY AND THE
UPPER MISSISSIPPI VALLEY BY 00Z TUESDAY. SO ALTHOUGH THE LOWER
TROPOSPHERIC FLOW ACROSS OUR AREA WILL START THE LONG TERM FORECAST
PERIOD FROM THE EAST/SOUTHEAST...A TRANSITION TO THE NORTHEAST IS
EXPECTED ACROSS MUCH OF THE AREA DURING THE DAY SUNDAY...AND TO
THE NORTHWEST SUNDAY NIGHT THROUGH MUCH OF THE REST OF THE LONG
TERM FORECAST PERIOD.
THE NAM...OPERATIONAL GFS AND EC ALL SUGGEST A 50-60KT JET STREAK
JUST ABOVE THE BOUNDARY LAYER WILL PROMOTE ENOUGH THERMAL ADVECTION
FOR PRECIPITATION PRODUCTION ACROSS MUCH OF THE CWA SATURDAY NIGHT
...ESPECIALLY ACROSS EASTERN PORTIONS OF THE CWA WHERE THERMAL
ADVECTION...AS WELL AS MOISTURE CONVERGENCE...WILL BE ENHANCED.
GIVEN THIS...WENT AHEAD WITH 20-70% POPS ACROSS MUCH OF THE CWA
SATURDAY NIGHT...WITH THE HIGHEST POPS RELEGATED ACROSS OUR EAST. AT
THIS TIME ANY CONVECTION THAT IS REALIZED SATURDAY NIGHT IS EXPECTED
TO REMAIN WEAK.
ANY OVERNIGHT CONVECTION SHOULD DEPART TO THE EAST/NORTHEAST BY
DAYBREAK SUNDAY AS THE LOWER TROPOSPHERIC JET STREAK ALSO SHIFTS TO
THE EAST. THIS MAY ALLOW FOR A BREAK IN PRECIPITATION AT SOME POINT
SUNDAY MORNING...BUT POPS STILL REMAIN INTACT FOR THE ENTIRE CWA ON
SUNDAY AS THERMAL ADVECTION AHEAD OF THE APPROACHING UPPER
TROPOSPHERIC TROUGH INCREASES. AS THE AFOREMENTIONED SURFACE LOW
MOVES INTO NORTHEASTERN KANSAS SUNDAY AFTERNOON AND EVENING...AN
ASSOCIATED LOWER TROPOSPHERIC BAROCLINIC ZONE IS EXPECTED TO BACK
NORTHWEST AS A WARM FRONT...PERHAPS PUSHING INTO OUR EXTREME
EAST/SOUTHEASTERN CWA. LOWER TROPOSPHERIC CONVERGENCE AND RESULTANT
LIFT ALONG THIS BAROCLINIC ZONE...ALONG WITH INCREASING SYNOPTIC-
SCALE OMEGA DUE TO INCREASING UPPER TROPOSPHERIC THERMAL ADVECTION
AHEAD OF THE APPROACHING TROUGH...APPEARS AS THOUGH THEY WILL BE
SUFFICIENT FOR CONVECTIVE INITIATION SUNDAY AFTERNOON AND EVENING.
SOME OF THIS CONVECTION COULD CERTAINLY BE REALIZED OVER OUR
EAST/SOUTHEAST SUNDAY AFTERNOON AND EVENING. THE BAROCLINIC ZONE
SHOULD QUICKLY DEPART OUR AREA TO THE EAST/SOUTHEAST SUNDAY EVENING
AS THE SURFACE LOW MOVES NORTHEAST...THUS ALLOWING A MUCH COOLER AND
DRIER LOWER TROPOSPHERIC AIR MASS INTO THE AREA. THIS WILL RESULT IN
RAPIDLY DECREASING POTENTIAL INSTABILITY THUS ELIMINATING ANY CHANCE
OF DEEP CONVECTION ACROSS OUR AREA. THAT BEING SAID...CONTINUED
THERMAL ADVECTION AHEAD OF THE APPROACHING TROUGH APPEARS IT WILL
STILL BE SUFFICIENT FOR PRECIPITATION PRODUCTION HEADING INTO THE
REMAINDER OF SUNDAY NIGHT AND EVEN MONDAY. AS A RESULT...POPS REMAIN
INTACT ACROSS MUCH OF THE CWA SUNDAY NIGHT INTO MONDAY. BY MONDAY
NIGHT...UPPER TROPOSPHERIC THERMAL ADVECTION SHOULD DIMINISH AS THE
TROUGH AXIS BEGINS CLEARING THE AREA. DRY CONDITIONS ARE CURRENTLY
FORECAST MONDAY NIGHT THROUGH WEDNESDAY AS A RESULT. WEDNESDAY NIGHT
INTO THURSDAY...THERE ARE INDICATIONS FROM THE OPERATIONAL GFS...AND
TO A LESSER EXTENT THE NAM...OF A WEAK UPPER TROPOSPHERIC
PERTURBATION MOVING ACROSS THE REGION AND PERHAPS PROVIDING A PERIOD
OF LIGHT PRECIPITATION. CONFIDENCE REGARDING THIS FEATURE IS NOT
HIGH...BUT ALLBLEND PRESENTED A ~20% POP TO OUR NORTH/NORTHEAST
WEDNESDAY NIGHT INTO THURSDAY AND OPTED TO KEEP THIS POP AS IS.
GUIDANCE SUGGESTS DEW POINT READINGS WELL INTO THE 60S WILL
INFILTRATE MUCH OF EASTERN KANSAS SUNDAY AFTERNOON ON THE WARM SIDE
OF THE BAROCLINIC ZONE. THE MOISTURE CONTENT OF THE LOWER
TROPOSPHERIC AIR MASS IS NOT EXPECTED TO BE NEARLY AS ROBUST FARTHER
NORTHWEST INTO OUR AREA...BUT AGAIN IF THE BAROCLINIC ZONE CAN SNEAK
INTO OUR EAST/SOUTHEAST SUNDAY AFTERNOON AND EVENING...THEN
POTENTIAL INSTABILITY VALUES COULD CERTAINLY CLIMB INTO THE 1000-
2000J/KG RANGE. DEEP LAYER BULK SHEAR VALUES ON THE ORDER OF ~50KTS
ARE ALSO FORECAST ACROSS OUR EAST/SOUTHEAST SUNDAY AFTERNOON AND
EVENING. SO...ALTHOUGH IT APPEARS THE BULK OF THE SEVERE WEATHER
SHOULD REMAIN SOUTH AND EAST OF OUR CWA...IT STILL APPEARS THERE
WILL BE A BRIEF WINDOW OF OPPORTUNITY FOR STRONG THUNDERSTORM
ACTIVITY ACROSS PORTIONS OF OUR CWA...GENERALLY ALONG AND SOUTHEAST
OF A LINE FROM ALMA TO YORK. A THREAT FOR SEVERE WEATHER WILL RESIDE
FARTHER SOUTHEAST...GENERALLY ALONG AND SOUTHEAST OF A LINE FROM
BELOIT TO HEBRON. WILL GO AHEAD AND MENTION THESE THREATS IN THE HWO
FOR SUNDAY.
GUIDANCE ALSO SUGGESTS LOWER TROPOSPHERIC PRESSURE RISES POST-FROPA
COULD PROVIDE A STRONG LOWER TROPOSPHERIC WIND FIELD ACROSS
NORTHWESTERN PORTIONS OF THE CWA SUNDAY AFTERNOON INTO SUNDAY
EVENING. GUIDANCE SUGGESTS A SUSTAINED WIND OF 25-30KTS WITH LOCALLY
HIGHER GUSTS WILL BE REALIZED AND AS A RESULT...WILL MENTION SUCH
CONDITIONS IN THE HWO.
A COOLER LOWER TROPOSPHERIC AIR MASS WILL INFILTRATE THE AREA
FOLLOWING THE PASSAGE OF THE BAROCLINIC ZONE SUNDAY...WITH HIGHS
GENERALLY IN THE 50 ON MONDAY AND IN THE 60S TUESDAY THROUGH FRIDAY.
OVERNIGHT LOWS IN THE 40S ARE FORECAST FOR THE MOST PART THROUGH THE
LONG TERM FORECAST PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1215 PM CDT FRI MAY 9 2014
A FEW MID LEVEL CLOUDS WILL MOVE THROUGH THE KGRI TERMINAL AREA
THIS AFTERNOON. FURTHER WEST THERE ARE SOME MID AND HIGH LEVEL
CLOUDS THAT WILL MOVE INTO THE AREA THIS EVENING.
&&
.FIRE WEATHER...
ISSUED AT 252 PM CDT FRI MAY 9 2014
RELATIVE HUMIDITY LEVELS ARE EXPECTED TO DROP BELOW 25 PERCENT FOR
NORTH CENTRAL KANSAS AND FAR SOUTHERN SOUTH CENTRAL NEBRASKA FOR
SATURDAY AFTERNOON. DURING THE MORNING THE WINDS WILL BE WEST OR
NORTHWEST AT 15 TO 20 MPH WITH GUSTS TO AROUND 25 MPH...BUT BY
AFTERNOON...WHEN THE RELATIVE HUMIDITY WILL BE THE LOWEST...THE
WINDS WILL HAVE DIMINISHED TO 10 TO 15 MPH WITH GUSTS TO 20 MPH.
EXPECT THERE TO ONLY BE A SMALL TIME FRAME WHERE NEAR CRITICAL FIRE
DANGER IS EVEN CLOSE. WILL LEAVE IT OUT OF THE HWO AT THIS TIME.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BRYANT
AVIATION...JCB
FIRE WEATHER...JCB
AREA FORECAST DISCUSSION
NWS ELKO NV
1012 AM PDT FRI MAY 9 2014
.SYNOPSIS...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE
EXPECTED ACROSS NORTHERN NEVADA TODAY. ANOTHER STORM SYSTEM WILL
BRING SHOWERS AND THUNDERSTORMS TO NORTHERN AND CENTRAL NEVADA
SATURDAY. SOME LIGHT SNOW ACCUMULATIONS WILL BE POSSIBLE ABOVE
6000 FT. WARM TEMPERATURES AND NICE WEATHER IS EXPECTED NEXT WEEK.
&&
.UPDATE...ALTHOUGH INSTABILITY IS RATHER WEAK...MID LEVEL LAPSE
RATES WILL STEEPEN THIS AFTERNOON. THIS COMBINED WITH A STRONG
~110 KNOT JET NOSING INTO NORTHERN NEVADA WILL PRODUCE SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS. HRRR SUPPORTS THIS SOLUTION
AND PROVIDES CONFIDENCE IN THIS FORECAST. ANY SHOWER/ISOLATED
STORM COULD PRODUCE SMALL HAIL...BRIEF HEAVY RAIN...AND GUSTY
WINDS. ACTIVITY WILL DIMINISH AFTER SUNSET.
&&
.PREV DISCUSSION... /ISSUED AT 509 AM /
SYNOPSIS...INTERMITTENT SHOWERS ARE EXPECTED AS ANOTHER LOW
PRESSURE SYSTEM APPROACHES. A STRONG COLD FRONT WILL MOVE THROUGH
THE STATE ON SATURDAY TO BRING THUNDERSTORMS ALONG WITH MORE RAIN
AND SNOW. LOW PRESSURE WILL BE EAST OF THE STATE ON MOTHERS
DAY...HOWEVER LINGERING SHOWERS AND A BRISK NORTH WIND MAY
INTERFERE WITH OUTDOOR PLANS. HIGH PRESSURE WILL BRING DRIER AND
WARMER CONDITIONS TO START THE WORK WEEK.
UPDATE...ADDED ISOLATED THUNDERSTORMS ACROSS NORTHERN ELKO COUNTY
FOR THIS MORNING. A FEW LIGHTNING STRIKES HAVE ALREADY OCCURRED
AND SEEM TO BE ASSOCIATED WITH THE LEFT FRONT QUAD OF A 100 KT
JET CORE MOVING OVER THE NORTHEAST PART OF THE STATE. THE NOSE OF
THIS JET FEATURE WILL PULL TO THE NORTH THIS MORNING.
PREV DISCUSSION... /ISSUED AT 312 AM /
SYNOPSIS...INTERMITTENT SHOWERS ARE EXPECTED AS ANOTHER LOW
PRESSURE SYSTEM APPROACHES. A STRONG COLD FRONT WILL MOVE THROUGH
THE STATE ON SATURDAY TO BRING THUNDERSTORMS ALONG WITH MORE RAIN
AND SNOW. LOW PRESSURE WILL BE EAST OF THE STATE ON MOTHERS
DAY...HOWEVER LINGERING SHOWERS AND A BRISK NORTH WIND MAY
INTERFERE WITH OUTDOOR PLANS. HIGH PRESSURE WILL BRING DRIER AND
WARMER CONDITIONS TO START THE WORK WEEK.
SHORT TERM...TODAY THROUGH SUNDAY. THE MODELS ARE IN VERY GOOD
AGREEMENT THROUGH SUNDAY. A ZONAL FLOW ALOFT IS SPREADING MOISTURE
ACROSS NORTHERN NEVADA AND KEEPING TEMPERATURES ELEVATED...RANGING
FROM THE MID 40S TO AROUND 50 DEGREES AS OF 1 AM PDT. THIS QUASI-
ZONAL FLOW AHEAD OF ANOTHER LOW PRESSURE SYSTEM WILL KEEP
UNSETTLED WEATHER GOING ACROSS PRIMARILY NORTHERN NEVADA THROUGH
TONIGHT. A RAPIDLY MOVING LOW PRESSURE SYSTEM WILL DROP SOUTH FROM
WASHINGTON STATE SATURDAY MORNING TO RE-CENTER OVER NORTHERN
NEVADA BY LATE SATURDAY NIGHT. THE SPEED OF THIS SYSTEM WILL
TRIGGER A STRONG COLD FRONT TO DEVELOP OVER THE GREAT BASIN EARLY
SATURDAY MORNING AND THUNDERSTORM ACTIVITY IS LIKELY TO BEGIN
EARLY AS WELL. SNOW LEVELS WILL DROP QUICKLY TO VALLEY FLOORS
SATURDAY ALONG THE DEVELOPING COLD FRONT. PASSES ALONG INTERSTATE 80
COULD RECEIVE A QUICK 2 INCH SNOW DEPOSIT. HOWEVER COMING OFF OF A
NIGHT WITH ABOVE-FREEZING TEMPERATURES IN MANY AREAS...ELEVATED
ROAD TEMPERATURES SHOULD BLUNT THE IMPACT. GUSTY WESTERLY WINDS
WILL BE INCREASING SATURDAY ASSOCIATED WITH THE FRONT HOWEVER
WIDESPREAD WIND ADVISORY CRITERIA IS NOT EXPECTED. SHOWERS WILL CONTINUE
ACROSS EASTERN NEVADA THROUGH SUNDAY EVENING AS THIS LOW PRESSURE
SYSTEM...LIKE THE LAST...SLOWLY EXITS THE GREAT BASIN. MOUNTAINS
OVER SOUTHEAST WHITE PINE COUNTY COULD SEE SEVERAL INCHES OF NEW
SNOW SATURDAY THROUGH SUNDAY. STRONG NORTHERLY WINDS ARE EXPECTED
ON MOTHERS DAY BEHIND THE EXITING LOW AS WELL. AT THIS
TIME...AREAS SOUTH OF HIGHWAY 50 ARE MODELED TO BE PRONE TO WIND
GUSTS TO AROUND 50 MPH.
HIGH TEMPERATURES WILL RANGE FROM THE MID 50S TO THE MID 60S
TODAY...AND ABOUT 10 DEGREES COOLER SATURDAY...REBOUNDING ON
SUNDAY. LOW TEMPERATURES WILL GENERALLY FALL INTO THE 30S
TONIGHT...AND INTO THE 20S IN MANY LOCATIONS SATURDAY NIGHT BEHIND
THE COLD FRONT.
LONG TERM...SUNDAY NIGHT THROUGH NEXT FRIDAY. THE SYNOPTIC PATTERN
WILL TRANSITION FROM BROAD CYCLONIC FLOW TO HIGH AMPLITUDE RIDGING
OVER THE WESTERN US. BY 12Z MONDAY...THE GFS HAS THE 570 DAM
BISECTING THE SILVER STATE FROM MCDERMITT TO TONOPAH...AND THE ECMWF
HAS THE 570 DAM NORTH OF MONTELLO AT 12Z ON MONDAY. FAST FORWARD 48
HRS...THE RIDGE BUILDS AND THE 582 DAM WILL SURGE INTO NORTHERN NV.
WITH WIDESPREAD SUBSIDENCE ON DECK...EXPECTING A WARMING AND DRYING
TREND. THE NCEP RMOP IS WELL INTO CONFIDENT TERRITORY WITH THE
RIDGE...AND EXPECTING POSITIVE HEIGHT ANOMALIES THE ENTIRE FORECAST
PERIOD. HIGH CONFIDENCE FORECAST. THE RETURN INTERVAL ON THE NAEFS
FOR TEMPS IS PINGING INTO A 30 YEAR EVENT ACROSS THE WEST...WITH A 5
TO 10 YEAR EVENT FOR SLP OVER THE LKN CWA. EXPECT AFTERNOON TEMPS IN
THE 70S ACROSS MOST POPULAR DESTINATIONS IN NE NV...WHILE MORE
REMOTE LOCALES AT SLIGHTLY LOWER ELEVATIONS SUCH AS GABBS AND THE
BLACK ROCK DESERT CAN EXPECT AFTERNOON TEMPERATURES IN THE 80S.
AVIATION...THE RADAR FOR NORTHEASTERN NV INDICATES ISOLATED TO
SCATTERED SHOWERS NORTH OF KWMC AND KEKO. BEST CHANCE OF
PRECIPITATION WILL BE AT KEKO THIS MORNING. GENERALLY EXPECTING CIGS
BETWEEN 050 AND 100...ALONG WITH OBSCURED MT TOPS. SLIGHT CHANCE FOR
PRECIP AT KELY...KEPT VCSH IN THE TAF AT KELY...NO PRECIP EXPECTED AT
KTPH FOR THE ENSUING 24 HR PERIOD.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
94/99
AREA FORECAST DISCUSSION
NWS BISMARCK ND
256 PM CDT FRI MAY 9 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 255 PM CDT FRI MAY 9 2014
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE
PRECIPITATION CHANCES TONIGHT AND SATURDAY. ECMWF HAS BEEN THE
MOST CONSISTENT OF THE DETERMINISTIC MODELS AND WILL USE FOR
PRECIPITATION DETAILS.
CURRENTLY...SUNNY SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA
WITH INCREASING CLOUDS MOVING FROM CENTRAL INTO EASTERN MONTANA.
TEMPERATURES ARE RANGING FROM THE MID 50S TO LOWER 60S ACROSS THE
STATE.
FOR TONIGHT...MODELS HAVE BEEN TRENDING A LITTLE SLOWER WITH THE
INITIAL PRECIPITATION MOVING INTO WESTERN NORTH DAKOTA TONIGHT AND
HAVE ADJUSTED POPS ACCORDINGLY. IN ADDITION...WITH THE SLOWER
MOVEMENT...LATEST 17 UTC HRRR AND 18 UTC RAP ARE INDICATING BEST
MOISTURE AND INSTABILITY NOT MAKING IT INTO WESTERN NORTH DAKOTA
UNTIL AROUND MIDNIGHT...OR AFTER. BY THIS TIME THINK THE
POSSIBILITY OF CONVECTION WILL BE MINIMAL SO WILL LEAVE OUT THE
MENTION OF THUNDER.
SATURDAY...A SPLIT UPPER LEVEL TROUGH TAKES SHAPE OVER THE WESTERN
U.S. WITH LEAD SHORTWAVE ENERGY FROM THE SOUTHERN WAVE EJECTING
INTO THE DAKOTAS. WITH AN ASSOCIATED SURFACE LOW LIFTING FROM
SOUTH DAKOTA INTO CENTRAL NORTH DAKOTA. PRECIPITATION CHANCES
WILL SPREAD SOUTHWEST TO NORTHEAST ACROSS THE CWA DURING THE DAY.
THERE MAY BE A BRIEF OPPORTUNITY FOR CONVECTION NEAR THE SURFACE
LOW AND ON THE BACK EDGE OF PRECIPITATION SHIELD IN THE SOUTH CENTRAL
SATURDAY AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 255 PM CDT FRI MAY 9 2014
AN ACTIVE AND COOL WEATHER PATTERN WILL BE THE MAIN STORY THROUGH
THE LONG TERM FORECAST PERIOD.
UPPER LOW/TROUGH OVER THE PACIFIC NORTHWEST DIGS ACROSS THE
WESTERN CONUS INTO SATURDAY...MOVING OVER THE ROCKIES SUNDAY. 12Z
MODELS HAVE COME INTO MUCH BETTER AGREEMENT WITH THE TROUGH
LINGERING ACROSS THE NORTHERN PLAINS INTO TUESDAY...FOLLOWED BY AN
ACTIVE NORTHWEST FLOW PATTERN FOR THE REST OF THE WORK WEEK.
WILL MAINTAIN CHANCES FOR PRECIPITATION THROUGH MUCH OF THE
PERIOD ALONG WITH CONTINUED COOL/BELOW AVERAGE TEMPERATURES.
FOR SATURDAY NIGHT-SUNDAY...EMBEDDED UPPER LEVEL LOW LIFTS SLOWLY
NORTH ACROSS THE DAKOTAS...PUTTING BEST PRECIP CHANCES NORTH AND
WRAP AROUND MOISTURE WEST. MIX OF RAIN/SNOW POSSIBLE WEST SUNDAY
MORNING AS COLDER AIR IS PULLED SOUTH FROM CANADA. SHOWERS
CONTINUE EAST AND NORTH DURING THE DAY SUNDAY ALONG WITH
INCREASING NORTHWESTERLY WINDS FROM WEST TO EAST BEHIND A SFC LOW.
SUBSIDENCE ACROSS THE WESTERN HALF OF THE STATE SUNDAY NIGHT
SHOULD DRY THINGS OUT WITH LINGERING MOISTURE EAST ALONG THE UPPER
TROUGH. WITH THE TROUGH SLOW TO MOVE EAST...DIURNALLY DRIVEN
SHOWERS WILL BE POSSIBLE BOTH MONDAY AND TUESDAY. MAY BE COLD
ENOUGH DURING THE OVERNIGHT/MORNING PERIODS FOR A RAIN/SNOW MIX
SOME LOCATIONS.
NORTHWEST FLOW WED-FRI WITH POSSIBLE EMBEDDED WAVES AND THE UPPER
JET ALOFT CONTINUING THE THREAT FOR PRECIPITATION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 255 PM CDT FRI MAY 9 2014
HIGH PRESSURE OVER CENTRAL NORTH DAKOTA WILL MOVE EAST AS LOW
PRESSURE MOVES THROUGH EASTERN MONTANA. CLEAR SKIES TO START THE
TAF PERIOD. POSSIBLE A FEW CUMULUS CLOUDS DURING THE AFTERNOON
WITH INCREASING HIGH LEVEL CLOUDINESS WEST BY LATE AFTERNOON.
CLOUDS WILL INCREASE WITH LOWERING CEILINGS FROM WEST TO EAST
TONIGHT AND SATURDAY. SHOWERS WILL BECOME LIKELY AT KDIK SATURDAY
MORNING AND HAVE ADDED SHRA WITH A LOW VFR CEILING BEGINNING AT 15
UTC. INCREASING SHOWER CHANCES AT KISN AND KBIS BY THE END OF THE
TAF PERIOD BUT WILL LEAVE OUT OF THE TAF FOR NOW...WITH BETTER
CHANCES AFTER 18 UTC.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...TWH
LONG TERM...NH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
448 PM EDT FRI MAY 9 2014
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL BRING A CHANCE OF SHOWERS AND
THUNDERSTORMS TONIGHT INTO SATURDAY. A DISTURBANCE BEHIND THE
FRONT WILL PROVIDE A CHANCE FOR MORE THUNDERSTORMS ON SUNDAY.
UNSETTLED WEATHER WILL CONTINUE INTO THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
SCATTERED SHOWERS CONTINUE TO AFFECT PORTIONS OF THE FA THIS AFTN.
THE BEST COVERAGE IS ACROSS THE SE COUNTIES ATTM. HRRR MODEL RUNS
HAVE BEEN HANDLING THE CONVECTION BEST THIS AFTN AND LEANED
TOWARDS ITS SOLUTION FOR THE EVENING INTO OVERNIGHT HOURS. EXPECT
SCATTERED CONVECTION TO CONTINUE TO PERCOLATE ACROSS THE NW
COUNTIES WHILE THE PCPN IN THE SE LIFTS NE ACROSS THE LOWER SCIOTO
VALLEY INTO THE HOCKING HILLS BEFORE PULLING E. THEN CONVECTION
OUT OVER THE LOWER OHIO VALLEY WILL BEGIN TO WORK IN TOWARDS
MIDNIGHT. COVERAGE SHOULD BE BEST ACROSS THE SOUTH...BUT CANT KEEP
THE N DRY. SFC BASED INSTABILITY WILL BEGIN TO WEAKEN WITH
SUNSET...SO EXPECT THE STRENGTH OF THE STORMS TO BE WEAKENING
ALSO. FEEL THE THREAT OF SEVERE WEATHER TONIGHT IS PRETTY LOW.
THE CDFNT WILL WORK INTO THE NW PORTION OF THE FA LATE TONIGHT
BRINGING AN END TO THE PCPN CHANCES THERE.
CLOUD COVER AND PCPN WILL HELP KEEP TEMPERATURES UP TONIGHT. THE
MAJORITY OF THE FA WILL SEE LOWS IN THE LOWER 60S...THE EXCEPTION
BEING THE EXTREME NW COUNTIES WHERE UPPER 50S ARE FORECAST BEHIND
THE FRONT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
THE MODELS HAVE FLIP-FLOPPED FROM YESTERDAYS PROGRESSIVE
CDFNT...BACK TO A SLOWER MORE SLUGGISH SOLUTION. H5 ENERGY
EJECTING OUT IN A BROAD SW FLOW WILL INTERACT THE CDFNT AND LOW
LEVEL MOISTURE TO PRODUCE SHOWERS AND THUNDERSTORMS SATURDAY. BEST
COVERAGE WILL BE IN THE S AND E AHEAD OF THE FRONT.
THE FRONT SAGS SOUTH THE OHIO RIVER SATURDAY AFTERNOON INTO
SATURDAY NIGHT...ALLOWING SLIGHTLY DRIER AIR TO FILTER IN. A
MOSTLY ZONAL H5 FLOW WILL ALLOW MORE UPPER LEVEL ENERGY TO RACE
ACROSS THE FA SUNDAY. WHILE THIS IS HAPPENING THE FRONT WILL LIFT
ACROSS THE FA AS A WARM FRONT. THIS MEANS ANOTHER CHANCE OF
SCATTERED CONVECTION ON SUNDAY.
ABOVE NORMAL TEMPERATURES ARE EXPECTED OVER THE WEEKEND. HIGHS ON
SATURDAY ARE FORECAST TO BE IN THE MID 70S...WITH UPPER 70S TO
LOWER 80S ON SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
RIDGE OF HIGH PRESSURE IN THE WAKE OF A WARM FRONT FROM SUNDAY NIGHT
WILL BUILD IN WITH INCREASING MOISTURE TO THE OHIO VALLEY THROUGH
WEDNESDAY. ON WEDNESDAY...A COLD FRONT WILL BE CROSSING THE REGION
EARLY...WITH SIGNIFICANTLY COOLER TEMPERATURES FOUND BEHIND IT ON
THIS DAY AND THURSDAY.
NATIONAL MODELLERS WERE LEANING TOWARDS THE SLOWER AND LESS
AMPLIFIED ECMWF ENSEMBLE SOLUTION BUT STILL HAD THE COLD FRONT
THROUGH WESTERN OHIO BY 12Z WED. THE HIGH TEMPS WED DID NOT AGREE
WITH THEIR SFC PROGS AND I COULD NOT COME IN LINE WITH THE 80 DEG AT
CMH NOTED FROM ECMWF. TOOK YESTERDAYS FORECAST AND BLENDED WITH THE
GFS/ECMWF...LEANING HEAVILY ON PREVIOUS COLDER FORECAST. THURSDAY
SHOULD BE THE COLDEST DAY IN THE FORECAST WITH HIGHS IN THE LOW TO
MID 60S. EVEN WITH A CONTINUED COLD ADVECTION PATTERN ON
FRIDAY...READINGS SHOULD BE AT LEAST A FEW DEGREES WARMER. OVERNIGHT
LOWS IN THE 60S MONDAY WILL DROP TO THE 50S TUESDAY AND ROUND OUT
THE WEEK IN 40S.
THE HIGHEST CHANCE FOR SHOWERS WILL OCCUR WITH THE FROPA TUES AND
EARLY WED. I DID NOT INCLUDE THUNDER MONDAY NIGHT THINKING THAT THE
WARM SECTOR SHOWERS WOULD BE VERY SPOTTY AND OCCUR UNDERNEATH THE
UPPER RIDGE. ONCE THE THUNDER THREAT PASSED ON WEDNESDAY IN THE WAKE
OF THE FRONT...SHOWERS WOULD BE POSSIBLE IN THE COLD POOL THURSDAY
AND TO A LESSER EXTENT FRIDAY...BOTH DUE TO THE DAYTIME SUN HITTING
A COOL AND MOIST COLUMN.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
OBSERVATIONS INDICATE THAT AN MVFR DECK HAS DEVELOPED WEST OF THE
AREA. THIS MAY WORK EAST AND TEMPORARILY IMPACT ALL BUT THE
COLUMBUS TERMINALS EARLY IN THE TAF PERIOD. SOUTH WINDS WILL GUST
UP TO 25 KT INTO THE EVENING. THERE WILL BE A CHANCE OF
THUNDERSTORMS AFTER 0Z. HAVE A ATTEMPTED TO KEEP A NARROW WINDOW
OF VCTS WHEN PROBABILITY IS HIGHEST. APPEARS THAT PERIODIC SHOWERS
COULD OCCUR WELL INTO THE NIGHT AFFECTING PRIMARILY KCVG/KLUK UP
TO KILN. BUT UNCERTAINTY IN COVERAGE/TIMING PRECLUDES ANYTHING
MORE THAN VCSH AT THIS TIME. MODERATE CONFIDENCE THAT CEILINGS
WILL LOWER TO MVFR AREA WIDE TOWARDS 12Z. BUT DO NOT EXPECT THIS
TO LAST LONG WITH IMPROVEMENT BACK TO VFR LATE IN THE TAF PERIOD.
OUTLOOK...THUNDERSTORMS POSSIBLE SUNDAY AND AGAIN ON TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO/SITES
NEAR TERM...SITES
SHORT TERM...SITES
LONG TERM...FRANKS
AVIATION...
AREA FORECAST DISCUSSION
NWS TULSA OK
1246 PM CDT FRI MAY 9 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
A COLD FRONT LOCATED OVER EAST CENTRAL OKLAHOMA TO FAR NORTHWEST
ARKANSAS EARLY THIS AFTERNOON IS EXPECTED TO STALL OVER SOUTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS MID/LATE AFTERNOON. THIS SHOULD
KEEP MVFR CLOUD CEILINGS AHEAD/EAST OF THE FRONT AND MOSTLY CLEAR
TO PARTLY CLOUDY VFR LEVEL CLOUDS BEHIND/WEST OF THE FRONT THROUGH
THE EVENING HOURS. ALSO ALONG AND EAST OF THE FRONT...A CHANCE OF
THUNDERSTORMS WILL BE POSSIBLE THROUGH THE EVENING...THOUGH WITH
LIMITED COVERAGE WILL KEEP MENTION OUT OF THE NORTHWEST ARKANSAS
TAF SITES. THE FRONT SHOULD BEGIN TO LIFT NORTHWARD
OVERNIGHT...SHIFTING WINDS BACK OUT OF THE SOUTH TO SOUTHEAST
WITH VFR CEILINGS. DURING THE MORNING HOURS SATURDAY...AREAS OF
FOG AND IFR/MVFR CEILINGS COULD BE POSSIBLE...WITH GREATER CHANCES
ACROSS NORTHWEST ARKANSAS.
&&
.PREV DISCUSSION... /ISSUED 1026 AM CDT FRI MAY 9 2014/
..UPDATE...
DISCUSSION...
A COLD FRONT WAS POSITIONED NEAR A LINE FROM GROVE TO JUST SOUTH
OF TULSA TO NEAR OKEMAH LATE THIS MORNING. BEHIND THE
FRONT...NORTHERLY WINDS AND PARTLY CLOUDY SKIES WERE BEING
OBSERVED. AHEAD OF THE FRONT...LOW CEILINGS WERE COMMON ACROSS THE
MAJORITY OF EASTERN OKLAHOMA AND NORTHWEST ARKANSAS. ALSO SOME
PATCHY AREAS OF LIGHT DRIZZLE HAVE BEEN REPORTED WITHIN THE LOW
CLOUDS THIS MORNING. A CHANCE OF A SHOWER AND OR A THUNDERSTORM
WILL ALSO BE POSSIBLE...MAINLY ACROSS FAR NORTHWEST ARKANSAS
THROUGH THE MORNING HOURS AHEAD OF THE FRONT.
THE COLD FRONT WILL CONTINUE ITS EASTWARD MOVEMENT INTO THE
AFTERNOON HOURS AND IS EXPECTED TO STALL ACROSS SOUTHEAST OKLAHOMA
INTO NORTHWEST ARKANSAS FOR THE LATE AFTERNOON/EVENING HOURS.
SKIES SHOULD CONTINUE TO SCATTER OUT BEHIND THE FRONT AND BECOME
PARTLY CLOUDY AHEAD OF THE FRONT...ALLOWING TEMPS TO GET INTO THE
70S TO LOW 80 FROM NORTH TO SOUTH. DIURNAL HEATING AND INSTABILITY
AHEAD OF THE FRONT WILL ALLOW FOR AT LEAST A SLIGHT CHANCE OF
THUNDERSTORMS THROUGH THE EVENING HOURS. THOUGH...LATEST HRRR AND
LOCAL IN-HOUSE MODEL RUNS ARE DEVELOPING ACTIVITY JUST TO THE EAST
OF THE CWA THIS AFTERNOON. ANY THUNDERSTORMS THAT DEVELOP WILL
HAVE THE POTENTIAL TO BECOME STRONG TO SEVERE...WITH LARGE
HAIL/STRONG WINDS BEING THE MAIN HAZARDS. FOR MORNING
UPDATE...WILL CONTINUE THE SLIGHT CHANCE OF THUNDERSTORMS ACROSS
THE EAST THIS AFTERNOON AND WILL ADD PATCHY DRIZZLE THROUGH THE
LATE MORNING HOURS AHEAD OF THE FRONT. HAVE ALSO TWEAKED SKY GRIDS
AND WILL MONITOR TEMPS THROUGH THE AFTERNOON FOR ANY ADDITIONAL
UPDATES.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 62 90 72 86 / 10 20 30 10
FSM 64 87 68 86 / 20 10 20 10
MLC 65 86 71 84 / 0 10 10 10
BVO 58 90 70 87 / 10 20 30 10
FYV 58 83 67 83 / 10 20 20 10
BYV 59 84 67 84 / 10 20 20 10
MKO 62 88 69 86 / 0 10 20 10
MIO 58 88 70 87 / 10 20 30 10
F10 63 89 70 85 / 0 10 20 10
HHW 65 87 69 85 / 20 10 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...20
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
540 PM EDT FRI MAY 9 2014
.SYNOPSIS...
A SURFACE WARM FRONT EXTENDING FROM THE FINGER LAKES REGION OF
NEW YORK SOUTH THROUGH THE SUSQUEHANNA VALLEY WILL DRIFT TO THE
NORTHEAST OF THE REGION TONIGHT. BEHIND THE FRONT IN THE WARM
SECTOR...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL
OCCUR OVER THE WESTERN HALF OF THE STATE LATE THIS AFTERNOON.
MORE NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS WILL DRIFT EAST
ACROSS PENNSYLVANIA TONIGHT AND SATURDAY...AS A COLD FRONT SLIDES
EAST FROM THE OHIO VALLEY. WARM...AND GENERALLY DRY WEATHER WILL
OCCUR ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
SCT SHRA AND A FEW TSRA DEVELOPING ACROSS THE WESTERN HALF OF PA
EARLY THIS EVENING AHEAD OF SHORTWAVE LIFTING OUT OF THE OHIO
VALLEY. DESPITE FAIRLY IMPRESSIVE SHEAR...THE CAPE AND ASSOC SVR
THREAT SHOULD REMAIN LOW. MORE NUMEROUS SHOWERS/TSTMS EXPECTED TO
WORK EASTWARD INTO PA LATER THIS EVENING...AS FORCING INCREASES
AHEAD OF SHORTWAVE. LATEST NAM/RAP OUTPUT SUGGEST THE BEST CHC OF
RAIN WILL WORK WEST TO EAST ACROSS CENTRAL PA BTWN 02Z-08Z.
BLEND OF LATEST ENSEMBLE AND OPER MDLS SUPPORT AVERAGE QPF THRU
12Z RANGING FROM ALMOST A HALF INCH ACROSS THE NW MTNS TO A TENTH
OF AN INCH OVR THE LOWER SUSQ VALLEY. OF COURSE...GIVEN POSITIVE
PWAT ANOMALIES IN THE 2-3SD RANGE...EXPECT LOCALLY HIGHER AMTS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
COLD FRONT PUSHES ACROSS THE STATE ON SAT...WITH NUMEROUS SHOWERS
AND ISO TSTMS CONTINUING THROUGH MAINLY FIRST HALF OF THE DAY
AHEAD OF IT. TOTAL QPF AMOUNTS TONIGHT INTO SAT WILL BE 0.25-0.50.
LATE DAY SAT INTO SUN THE RIDGE BUILDS BACK INTO PA...WITH MILD
WEATHER CONTINUING.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
SHRA/TSRA AND HIGHER PWATS SHUNTED EAST OF THE REGION SAT NIGHT
AS THE COLD FRONT PASSES. SUNDAY LOOKS LIKE A PRETTY NICE
DAY...WITH SKIES BECOMING PARTLY TO MOSTLY SUNNY.
UPPER-LEVEL RIDGE ESTABLISHES ITSELF EARLY NEXT WEEK...PROVIDING
INCREASING WARMTH AND HUMIDITY ACROSS CENTRAL PA. AN AFTN
SHRA/TSRA IS POSSIBLE MONDAY...WITH A BETTER CHC TUESDAY AS THE
NEXT FRONTAL SYSTEM NEARS.
WED AND THU LOOK UNSETTLED...WITH A GOOD CHC OF SHRA/TSRA AS A
SLOW-MOVING FRONT CROSSES THE REGION. THE 12Z ECMWF DEVELOPS A
WAVE OF LOW PRES ON THE FRONT...SLOWING THE FRONTAL PASSAGE UNTIL
SOMETIME FRIDAY. THEREFORE...HELD ONTO SOME POPS INTO FRIDAY DUE
TO THE UNCERTAINTY.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
TAFS ADJUSTED FOR CONVECTION. STORMS TO THE SW OF UNV MOVING
NE...WHILE STORMS NEAR BFD MOVING MORE TO THE EAST...AND THIS
SET HAVE A HISTORY OF GUSTY WINDS.
EARLIER DISCUSSION BELOW.
CIG RESTRICTIONS HAVE FINALLY ABATED ACROSS THE LOWER SUSQ AS
FORMERLY STABLE LOW LEVELS BEGIN TO MIX JUST AHEAD OF A SLOWLY
APPROACHING WARM FRONT...BUT MVFR VSBYS IN HAZE WILL REMAIN
THROUGH THE AFTERNOON.
ON THE OTHER SIDE OF THE FRONT IN THE WARM SECTOR...VFR CONDS
WILL PREVAIL OVER THE WRN/CNTRL AIRSPACE INTO LATE EVENING/EARLY
SAT MORNING. HRRR MODEL DATA INDICATE ISOLD-SCT SHWRS/TSTMS
DEVELOPING OVER THE WRN 1/3 OF THE AIRSPACE BY MID AFTERNOON...AND
RADAR BEGINNING TO CONFIRM THAT THINKING...WITH A MORE PERSISTENT
LINE OF CONVECTION MOVING ACROSS E OHIO. ADDED VCTS TO KBFD TAF
AFTER 21Z...BUT CONFIDENCE IN TERMINAL IMPACTS INCLUDING TIMING
IS LOW ELSEWHERE AND CONTINUED THE VCSH TO CONVEY POTENTIAL UNTIL
STORMS BECOME MORE IMMINENT AT SPECIFIC TERMINALS LATE THIS AFT
AND EARLY THIS EVE.
HIGHER PROBS FOR PRE-FRONTAL SHWRS/ISO TSTMS TONIGHT WITH
MARGINAL RESTRICTIONS AGAIN DEVELOPING...ESP WRN 1/3. WIDESPREAD
RAIN SHOWERS/ISO TSTMS REMAIN POSS THROUGH FIRST HALF OF SAT
BEFORE TAPERING OFF FROM THE NW.
.OUTLOOK...
SAT...SCT-NMRS SHRA/TSTMS THUNDERSTORMS WITH OCNL MVFR CIGS AND
VSBYS ALONG/AHEAD OF A SLOW MOVING COLD FRONT.
SUN...BCMG VFR.
SUN NGT-TUE...VFR/MVFR WITH CHC SHRA/TSRA.
WED...RAIN AND RESTRICTIONS LIKELY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT/RXR
NEAR TERM...FITZGERALD/RXR
SHORT TERM...RXR
LONG TERM...EVANEGO
AVIATION...MARTIN/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
521 PM EDT FRI MAY 9 2014
.SYNOPSIS...
A SURFACE WARM FRONT EXTENDING FROM THE FINGER LAKES REGION OF NEW
YORK SOUTH THROUGH THE SUSQUEHANNA VALLEY WILL DRIFT TO THE
NORTHEAST OF THE REGION TONIGHT. BEHIND THE FRONT IN THE WARM
SECTOR...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL
OCCUR OVER THE WESTERN HALF OF THE STATE LATE THIS AFTERNOON.
MORE NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS WILL DRIFT EAST
ACROSS PENNSYLVANIA TONIGHT AND SATURDAY...AS A COLD FRONT SLIDES
EAST FROM THE OHIO VALLEY. WARM...AND GENERALLY DRY WEATHER WILL
OCCUR ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
SCT SHRA AND A FEW TSRA DEVELOPING ACROSS THE WESTERN HALF OF PA
EARLY THIS EVENING AHEAD OF SHORTWAVE LIFTING OUT OF THE OHIO
VALLEY. DESPITE FAIRLY IMPRESSIVE SHEAR...THE CAPE AND ASSOC SVR
THREAT SHOULD REMAIN LOW. MORE NUMEROUS SHOWERS/TSTMS EXPECTED TO
WORK EASTWARD INTO PA LATER THIS EVENING...AS FORCING INCREASES
AHEAD OF SHORTWAVE. LATEST NAM/RAP OUTPUT SUGGEST THE BEST CHC OF
RAIN WILL WORK WEST TO EAST ACROSS CENTRAL PA BTWN 02Z-08Z.
BLEND OF LATEST ENSEMBLE AND OPER MDLS SUPPORT AVERAGE QPF THRU
12Z RANGING FROM ALMOST A HALF INCH ACROSS THE NW MTNS TO A TENTH
OF AN INCH OVR THE LOWER SUSQ VALLEY. OF COURSE...GIVEN POSITIVE
PWAT ANOMALIES IN THE 2-3SD RANGE...EXPECT LOCALLY HIGHER AMTS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
COLD FRONT PUSHES ACROSS THE STATE ON SAT...WITH NUMEROUS SHOWERS
AND ISO TSTMS CONTINUING THROUGH MAINLY FIRST HALF OF THE DAY
AHEAD OF IT. TOTAL QPF AMOUNTS TONIGHT INTO SAT WILL BE 0.25-0.50.
LATE DAY SAT INTO SUN THE RIDGE BUILDS BACK INTO PA...WITH MILD
WEATHER CONTINUING.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
SHRA/TSRA AND HIGHER PWATS SHUNTED EAST OF THE REGION SAT NIGHT
AS THE COLD FRONT PASSES. SUNDAY LOOKS LIKE A PRETTY NICE
DAY...WITH SKIES BECOMING PARTLY TO MOSTLY SUNNY.
UPPER-LEVEL RIDGE ESTABLISHES ITSELF EARLY NEXT WEEK...PROVIDING
INCREASING WARMTH AND HUMIDITY ACROSS CENTRAL PA. AN AFTN
SHRA/TSRA IS POSSIBLE MONDAY...WITH A BETTER CHC TUESDAY AS THE
NEXT FRONTAL SYSTEM NEARS.
WED AND THU LOOK UNSETTLED...WITH A GOOD CHC OF SHRA/TSRA AS A
SLOW-MOVING FRONT CROSSES THE REGION. THE 12Z ECMWF DEVELOPS A
WAVE OF LOW PRES ON THE FRONT...SLOWING THE FRONTAL PASSAGE UNTIL
SOMETIME FRIDAY. THEREFORE...HELD ONTO SOME POPS INTO FRIDAY DUE
TO THE UNCERTAINTY.
&&
.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
CIG RESTRICTIONS HAVE FINALLY ABATED ACROSS THE LOWER SUSQ AS
FORMERLY STABLE LOW LEVELS BEGIN TO MIX JUST AHEAD OF A SLOWLY
APPROACHING WARM FRONT...BUT MVFR VSBYS IN HAZE WILL REMAIN
THROUGH THE AFTERNOON.
ON THE OTHER SIDE OF THE FRONT IN THE WARM SECTOR...VFR CONDS
WILL PREVAIL OVER THE WRN/CNTRL AIRSPACE INTO LATE EVENING/EARLY
SAT MORNING. HRRR MODEL DATA INDICATE ISOLD-SCT SHWRS/TSTMS
DEVELOPING OVER THE WRN 1/3 OF THE AIRSPACE BY MID AFTERNOON...AND
RADAR BEGINNING TO CONFIRM THAT THINKING...WITH A MORE PERSISTENT
LINE OF CONVECTION MOVING ACROSS E OHIO. ADDED VCTS TO KBFD TAF
AFTER 21Z...BUT CONFIDENCE IN TERMINAL IMPACTS INCLUDING TIMING
IS LOW ELSEWHERE AND CONTINUED THE VCSH TO CONVEY POTENTIAL UNTIL
STORMS BECOME MORE IMMINENT AT SPECIFIC TERMINALS LATE THIS AFT
AND EARLY THIS EVE.
HIGHER PROBS FOR PRE-FRONTAL SHWRS/ISO TSTMS TONIGHT WITH
MARGINAL RESTRICTIONS AGAIN DEVELOPING...ESP WRN 1/3. WIDESPREAD
RAIN SHOWERS/ISO TSTMS REMAIN POSS THROUGH FIRST HALF OF SAT
BEFORE TAPERING OFF FROM THE NW.
.OUTLOOK...
SAT...SCT-NMRS SHRA/TSTMS THUNDERSTORMS WITH OCNL MVFR CIGS AND
VSBYS ALONG/AHEAD OF A SLOW MOVING COLD FRONT.
SUN...BCMG VFR.
SUN NGT-TUE...VFR/MVFR WITH CHC SHRA/TSRA.
WED...RAIN AND RESTRICTIONS LIKELY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT/RXR
NEAR TERM...FITZGERALD/RXR
SHORT TERM...RXR
LONG TERM...EVANEGO
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
339 PM EDT FRI MAY 9 2014
.SYNOPSIS...
A SURFACE WARM FRONT EXTENDING FROM THE FINGER LAKES REGION OF NEW
YORK SOUTH THROUGH THE SUSQUEHANNA VALLEY WILL DRIFT TO THE
NORTHEAST OF THE REGION TONIGHT. BEHIND THE FRONT IN THE WARM
SECTOR...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL
OCCUR OVER THE WESTERN HALF OF THE STATE LATE THIS AFTERNOON.
MORE NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS WILL DRIFT EAST
ACROSS PENNSYLVANIA TONIGHT AND SATURDAY...AS A COLD FRONT SLIDES
EAST FROM THE OHIO VALLEY. WARM...AND GENERALLY DRY WEATHER WILL
OCCUR ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LOW CLOUDS ACROSS LOWER SUSQ FINALLY HAVE BROKEN THIS MID
AFTERNOON JUST AHEAD OF A SLOWLY APPROACHING WARM FRONT.
BEHIND THE FRONT IN THE WARM SECTOR...ISO SHOWERS/TSTMS DEVELOPING
ACROSS W PA AS FORCING/LIFT BEGIN TO INCREASE AHEAD OF SLOWLY
APPROACHING COLD FRONT. MORE NUMEROUS SHOWERS/TSTMS OVER
OHIO...AND THESE WILL WORK EASTWARD INTO PA BY EARLY EVENING. IN
ADDITION...PRECIP SHIELD WILL FILL IN OVERNIGHT AS INCREASING
SOUTHWESTERLY LLJ SHIFTS EASTWARD.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
COLD FRONT PUSHES ACROSS THE STATE ON SAT...WITH NUMEROUS SHOWERS
AND ISO TSTMS CONTINUING THROUGH MAINLY FIRST HALF OF THE DAY
AHEAD OF IT. TOTAL QPF AMOUNTS TONIGHT INTO SAT WILL BE 0.25-0.50.
LATE DAY SAT INTO SUN THE RIDGE BUILDS BACK INTO PA...WITH MILD
WEATHER CONTINUING.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
SHRA/TSRA AND HIGHER PWATS SHUNTED EAST OF THE REGION SAT NIGHT
AS THE COLD FRONT PASSES. SUNDAY LOOKS LIKE A PRETTY NICE
DAY...WITH SKIES BECOMING PARTLY TO MOSTLY SUNNY.
UPPER-LEVEL RIDGE ESTABLISHES ITSELF EARLY NEXT WEEK...PROVIDING
INCREASING WARMTH AND HUMIDITY ACROSS CENTRAL PA. AN AFTN
SHRA/TSRA IS POSSIBLE MONDAY...WITH A BETTER CHC TUESDAY AS THE
NEXT FRONTAL SYSTEM NEARS.
WED AND THU LOOK UNSETTLED...WITH A GOOD CHC OF SHRA/TSRA AS A
SLOW-MOVING FRONT CROSSES THE REGION. THE 12Z ECMWF DEVELOPS A
WAVE OF LOW PRES ON THE FRONT...SLOWING THE FRONTAL PASSAGE UNTIL
SOMETIME FRIDAY. THEREFORE...HELD ONTO SOME POPS INTO FRIDAY DUE
TO THE UNCERTAINTY.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
CIG RESTRICTIONS HAVE FINALLY ABATED ACROSS THE LOWER SUSQ AS
FORMERLY STABLE LOW LEVELS BEGIN TO MIX JUST AHEAD OF A SLOWLY
APPROACHING WARM FRONT...BUT MVFR VSBYS IN HAZE WILL REMAIN
THROUGH THE AFTERNOON.
ON THE OTHER SIDE OF THE FRONT IN THE WARM SECTOR...VFR CONDS
WILL PREVAIL OVER THE WRN/CNTRL AIRSPACE INTO LATE EVENING/EARLY
SAT MORNING. HRRR MODEL DATA INDICATE ISOLD-SCT SHWRS/TSTMS
DEVELOPING OVER THE WRN 1/3 OF THE AIRSPACE BY MID AFTERNOON...AND
RADAR BEGINNING TO CONFIRM THAT THINKING...WITH A MORE PERSISTENT
LINE OF CONVECTION MOVING ACROSS E OHIO. ADDED VCTS TO KBFD TAF
AFTER 21Z...BUT CONFIDENCE IN TERMINAL IMPACTS INCLUDING TIMING
IS LOW ELSEWHERE AND CONTINUED THE VCSH TO CONVEY POTENTIAL UNTIL
STORMS BECOME MORE IMMINENT AT SPECIFIC TERMINALS LATE THIS AFT
AND EARLY THIS EVE.
HIGHER PROBS FOR PRE-FRONTAL SHWRS/ISO TSTMS TONIGHT WITH
MARGINAL RESTRICTIONS AGAIN DEVELOPING...ESP WRN 1/3. WIDESPREAD
RAIN SHOWERS/ISO TSTMS REMAIN POSS THROUGH FIRST HALF OF SAT
BEFORE TAPERING OFF FROM THE NW.
.OUTLOOK...
SAT...SCT-NMRS SHRA/TSTMS THUNDERSTORMS WITH OCNL MVFR CIGS AND
VSBYS ALONG/AHEAD OF A SLOW MOVING COLD FRONT.
SUN...BCMG VFR.
SUN NGT-TUE...VFR/MVFR WITH CHC SHRA/TSRA.
WED...RAIN AND RESTRICTIONS LIKELY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT/RXR
NEAR TERM...RXR
SHORT TERM...RXR
LONG TERM...EVANEGO
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
330 PM EDT FRI MAY 9 2014
.SYNOPSIS...
A SURFACE WARM FRONT EXTENDING FROM THE FINGER LAKES REGION OF NEW
YORK SOUTH THROUGH THE SUSQUEHANNA VALLEY WILL DRIFT TO THE
NORTHEAST OF THE REGION TONIGHT. BEHIND THE FRONT IN THE WARM
SECTOR...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL
OCCUR OVER THE WESTERN HALF OF THE STATE LATE THIS AFTERNOON.
MORE NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS WILL DRIFT EAST
ACROSS PENNSYLVANIA TONIGHT AND SATURDAY...AS A COLD FRONT SLIDES
EAST FROM THE OHIO VALLEY. WARM...AND GENERALLY DRY WEATHER WILL
OCCUR ON SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LOW CLOUDS ACROSS LOWER SUSQ FINALLY HAVE BROKEN THIS MID
AFTERNOON JUST AHEAD OF A SLOWLY APPROACHING WARM FRONT.
BEHIND THE FRONT IN THE WARM SECTOR...ISO SHOWERS/TSTMS DEVELOPING
ACROSS W PA AS FORCING/LIFT BEGIN TO INCREASE AHEAD OF SLOWLY
APPROACHING COLD FRONT. MORE NUMEROUS SHOWERS/TSTMS OVER
OHIO...AND THESE WILL WORK EASTWARD INTO PA BY EARLY EVENING. IN
ADDITION...PRECIP SHIELD WILL FILL IN OVERNIGHT AS INCREASING
SOUTHWESTERLY LLJ SHIFTS EASTWARD.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
COLD FRONT PUSHES ACROSS THE STATE ON SAT...WITH NUMEROUS SHOWERS
AND ISO TSTMS CONTINUING THROUGH MAINLY FIRST HALF OF THE DAY
AHEAD OF IT. TOTAL QPF AMOUNTS TONIGHT INTO SAT WILL BE 0.25-0.50.
LATE DAY SAT INTO SUN THE RIDGE BUILDS BACK INTO PA...WITH MILD
WEATHER CONTINUING.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
SFC COLD FRONT WILL PUSH SOUTH OF THE STATE BY LATE SAT
NIGHT...WITH A DRY SUNDAY LIKELY FOR MOST OF CENTRAL PA IN IT/S
WAKE. GIVEN THE NW FLOW...ALONG WITH RESIDUAL MOISTURE...THERE IS
A SLIGHT CHANCE FOR UPSLOPE SHOWERS IN THE NW MTNS. TEMPERATURES
WILL DROP IN THE WAKE OF THE COLD FRONT ON SATURDAY...WITH HIGHS
CLOSER TO NORMAL.
HOWEVER TEMPERATURES WILL REBOUND TO THE MID 70S BY SUNDAY...AND
INTO THE 80S AS A BNDRY SHOULD COME CHARGING BACK AS A WARM FRONT
ON MONDAY. DEEP SOUTHERLY FLOW DEVELOPS AHEAD OF DIGGING TROF OVR
THE PLAINS. SCT CONVECTION IS LIKELY TO ACCOMPANY PASSAGE OF
WFRONT MONDAY. PASSAGE OF RIDGE AXIS AND ANOMALOUS TEMPS ALOFT
COULD SUPPRESS CONVECTION TUESDAY AND RESULT IN A VERY WARM DAY
WITH HIGHS WELL INTO THE 80S GIVEN 12Z EC ENS MEAN 8H TEMPS ARND
16C.
THE GFS ENSEMBLES SHOW SIGNIFICANT TIMING DIFFERENCES WITH REGARD
TO PASSAGE OF THE NEXT DEEP TROF AND ASSOCIATED SLOW- MOVING COLD
FRONT DURING THE MIDDLE OF NEXT WEEK. HOWEVER...EC ENSEMBLE AND
GEFS SUPPORT A SLOWER SOLUTION THAN THE OPERATIONAL GFS...IMPLYING
A GOOD CHANCE OF WET WEATHER BY WED. THIS DEEP TROUGH SHOULD
DICTATE THE PATTERN LATE NEXT WEEK.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
CIG RESTRICTIONS HAVE FINALLY ABATED ACROSS THE LOWER SUSQ AS
FORMERLY STABLE LOW LEVELS BEGIN TO MIX JUST AHEAD OF A SLOWLY
APPROACHING WARM FRONT...BUT MVFR VSBYS IN HAZE WILL REMAIN
THROUGH THE AFTERNOON.
ON THE OTHER SIDE OF THE FRONT IN THE WARM SECTOR...VFR CONDS
WILL PREVAIL OVER THE WRN/CNTRL AIRSPACE INTO LATE EVENING/EARLY
SAT MORNING. HRRR MODEL DATA INDICATE ISOLD-SCT SHWRS/TSTMS
DEVELOPING OVER THE WRN 1/3 OF THE AIRSPACE BY MID AFTERNOON...AND
RADAR BEGINNING TO CONFIRM THAT THINKING...WITH A MORE PERSISTENT
LINE OF CONVECTION MOVING ACROSS E OHIO. ADDED VCTS TO KBFD TAF
AFTER 21Z...BUT CONFIDENCE IN TERMINAL IMPACTS INCLUDING TIMING
IS LOW ELSEWHERE AND CONTINUED THE VCSH TO CONVEY POTENTIAL UNTIL
STORMS BECOME MORE IMMINENT AT SPECIFIC TERMINALS LATE THIS AFT
AND EARLY THIS EVE.
HIGHER PROBS FOR PRE-FRONTAL SHWRS/ISO TSTMS TONIGHT WITH
MARGINAL RESTRICTIONS AGAIN DEVELOPING...ESP WRN 1/3. WIDESPREAD
RAIN SHOWERS/ISO TSTMS REMAIN POSS THROUGH FIRST HALF OF SAT
BEFORE TAPERING OFF FROM THE NW.
.OUTLOOK...
SAT...SCT-NMRS SHRA/TSTMS THUNDERSTORMS WITH OCNL MVFR CIGS AND
VSBYS ALONG/AHEAD OF A SLOW MOVING COLD FRONT.
SUN...BCMG VFR.
SUN NGT-TUE...VFR/MVFR WITH CHC SHRA/TSRA.
WED...RAIN AND RESTRICTIONS LIKELY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LAMBERT/RXR
NEAR TERM...RXR
SHORT TERM...RXR
LONG TERM...FITZGERALD/LAMBERT
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
655 PM EDT FRI MAY 9 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL BE MOVING TOWARD THE CENTRAL APPALACHIANS
SATURDAY...ORIENTING ITSELF WEST TO EAST ACROSS THE OHIO VALLEY TO
MID ATLANTIC SUNDAY. RIDGE BUILDS SUNDAY INTO MONDAY SENDING THIS
FRONT NORTH. A STRONGER COLD FRONT ARRIVES IN THE WEDNESDAY TIME
FRAME...SLOWING DOWN AS IT MOVES EAST OF THE APPALACHIANS INTO
LATE WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 645 PM EDT FRIDAY...
COVERAGE OF SHOWERS HAD FILLED IN OVER MUCH OF THE FORECAST AREA
THIS EVENING. HAVE INCREASED PROBABILITY OF SHOWERS BASED ON RADARTRENDS.
LIGHTNING ACTIVITY HAS BEEN CONFINED TO JUST SOUTH OF THE COUNTY
WARNING AREA...BUT ISOLATED THUNDERSTORMS ARE STILL
POSSIBLE...ESPECIALLY SOUTH AND EAST OF DANVILLE.
SHORTWAVE ENERGY ACROSS TN PER LATEST RAP MODEL SHOULD HEAD NE INTO
THE CENTRAL APPALACHIANS BY DUSK WITH INCREASED THREAT OF SHOWERS
AND STORMS IN THE WESTERN CWA. INSTABILITY IN THE EAST IS HIGHER PER
MORE SUN EARLIER RAISING SBCAPES TO 500-1000 J/KG...WITH DCAPES OVER
1000 J/KG GIVEN DRIER AIR IN THE LOW LVLS. SOME OF THE SHOWERS OR
STORMS COULD PRODUCE GUSTY WINDS BUT OVERALL WIND ENERGY IS WEAK
COMPARED TO THE WRN OHIO VALLEY.
THE THREAT OF SHOWERS WILL DIMINISH AFTER MIDNIGHT THOUGH ENOUGH LOW
LVL CONVERGENCE WITH SW FLOW ALOFT AND APPROACHING FRONT INTO THE
OHIO VALLEY TO KEEP SOME CHANCE IN OVER THE MTNS OVERNIGHT.
MODELS SHOWING SHORTWAVE PUSHING NE ACROSS CENTRAL NC OVERNIGHT
WHICH COULD PRODUCE A SHOWER OR TWO OUT EAST. THE BETTER THREAT
ARRIVES ACROSS THE REGION SATURDAY AND ESPECIALLY CLOSER TO THE
FRONT AND UPPER SUPPORT PUSHING ACROSS THE OHIO VALLEY INTO MID
ATLANTIC. KEPT POPS IN THE LIKELY RANGE MAINLY WEST OF I-81 IN
VIRGINIA...AND ACROSS THE NC MTNS TO LOWER CHANCES IN THE PIEDMONT.
WITH PLENTY OF CLOUDS TONIGHT....AND HUMIDITY INCREASING...TEMPS
SHOULD DROP INTO THE MID TO UPPER 50S MOUNTAINS TO LOWER TO MID 60S
EAST.
SATURDAY WILL BE COOLER WITH PLENTY OF CLOUD COVER. SOME SUNSHINE
COULD BREAK OUT ACROSS THE EAST IN THE AFTERNOON. OVERALL LOOKING AT
HIGHS FROM THE LOWER 70S MOUNTAINS TO NEAR 80 EAST.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 200 PM EDT FRIDAY...
WEAK BOUNDARY SETTLES NEAR THE REGION SATURDAY...WITH UPPER LEVEL
DISTURBANCES/JET STREAK ADDING TO LIFT. MOST OF THE SHOWERS AND
STORMS WILL BE DIURNAL IN NATURE AND ENDING SATURDAY NIGHT.
SUMMERLIKE PATTERN CONTINUES THROUGH THE WEEKEND WITH LESS COVERAGE
ON SUNDAY...BUT STILL LATE DAY STORMS IN THE WEST WITH SURFACE
CONVERGENCE ALONG THE MOUNTAINS. EVEN LESS OF A CHANCE ON MONDAY AS
RIDGE BUILDS AND HEIGHTS RISE SLIGHTLY...WASHING OUT OR PUSHING
NORTH WHATEVER BOUNDARY REMAINS FROM THE WEEKEND. MAX T WILL BE
HIGHLY DEPENDENT ON WHAT SITES GET HIT WITH STORMS...BUT H85 TEMPS
WILL RISE BACK FROM 16-18C SUNDAY AND MONDAY...AFTER SOMEWHAT COOLER
VALUES ON SATURDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 200 PM EDT FRIDAY...
PHASED FULL LATITUDE TROUGH DEVELOPING ALONG THE CONTINENTAL DIVIDE
ON MONDAY...WILL MOVE EAST AND LOOKS TO BE FORMIDABLE ENOUGH TO
DISLODGE THE STRONG UPPER RIDGE AND CHANGE THE PATTERN THROUGH THE
MIDDLE ATLANTIC AND SOUTHEAST. WEDNESDAY NIGHT LOOKS TO BE THE BEST
TIMEFRAME FOR THE STRONG COLD FRONT ASSOCIATED WITH THIS TROUGH TO
CROSS OUR REGION...WITH MORE WIDESPREAD STORMS LATE WED AND WED
NIGHT. WITH THE UPPER RIDGE NEARLY CLOSED OFF OVERHEAD ON
TUESDAY...CHCS OF STORMS MAY BE THE SMALLEST THAT DAY...ALTHOUGH
STILL CAN`T RULE OUT ISOLATED THUNDERSTORMS ANCHORED TO THE HIGHEST
PEAKS...ESPECIALLY WESTERN GREENBRIER. H85 TEMPS MAY FALL TO 5C
ACROSS THE REGION BY LATE WEEK BEHIND THE FRONT...WHICH WILL BE
QUITE AN IMPRESSIVE COOL DOWN CONSIDERING THE STRING OF 80F HIGHS
EXPECTED THIS WEEKEND AND MUCH OF THE UPCOMING WEEK. THE AIRMASS IS
SO COLD ALOFT THAT THERE MAY BE SOME INSTABILITY SHOWERS IN THE
AFTERNOON LATE WEEK OR NEXT WEEKEND...WITH THE MODELS TYPICALLY POOR
AT PREDICTING QPF THIS MANY DAYS AWAY IN THIS SETUP.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 140 PM EDT FRIDAY...
WILL EXPERIENCE VFR CONDITIONS THROUGH THE AFTERNOON INTO THE
EVENING. ISOLATED TO SCATTERED SHOWERS ALONG WITH A THUNDERSTORM
COULD IMPACT BCB/BLF/LWB THIS AFTERNOON INTO ROANOKE LATE
AFTERNOON. CONFIDENCE NOT HIGH ENOUGH FOR PREDOMINANT THUNDER...AS
INSTABILITY AND COVERAGE NOT ALL THAT HIGH.
ISSUE TONIGHT WILL BE THE COVERAGE OF RAIN SHOWERS AND EFFECT ON
CIGS AND VSBYS. ATTM...MODELS AND FORECAST SOUNDINGS SUGGEST
LIMITED THREAT OF SUB VFR CIGS/VSBYS THOUGH MOISTENING OF THE
AIRMASS MAY FAVOR SOME FOG IN THE VALLEYS AROUND BCB/LWB/DAN. WILL
LEAVE OUT FOR NOW. SHOULD BE A LULL IN PRECIP OVERNIGHT.
FRONT APPEARS TO BE STAYING NORTHWEST OF US INTO SATURDAY AS UPPER
LEVELS ENERGY SHEARS OUT TO THE NORTHEAST. WILL SEE SCATTERED
TO NUMEROUS COVERAGE ACROSS BY LATE SAT MORNING INTO THE AFTERNOON
MAINLY WEST OF THE BLUE RIDGE.
GUSTY SW WINDS THIS AFTERNOON TAPER OFF THIS EVENING THEN KICK UP
AGAIN LATE SAT MORNING...GENERALLY GUSTS AROUND 15-25 KNOTS.
LIKELIHOOD FOR SUB-VFR AT TIMES SATURDAY AFTERNOON WITH SHRA/TSRA
AHEAD OF THE FRONT MOVING SLOWLY EAST AND DEEPER MOISTURE IN
PLACE. BOUNDARY MAY WASH OUT UPON CROSSING THE AREA OR STALL JUST
OFF TO THE WEST BY SUNDAY WITH MAINLY VFR CONDITIONS EXPECTED
OUTSIDE OF OCNL MVFR IN MAINLY ISOLATED MOUNTAIN SHOWERS AS
LEFTOVER MOISTURE APPEARS QUITE SHALLOW. RIDGE OFFSHORE
STRENGTHENS AGAIN ON MONDAY AHEAD OF ANOTHER FRONT TO THE WEST
WITH MAINLY VFR EXCLUDING PERHAPS BRIEF MVFR IN A LATE DAY SHRA
ESPCLY MOUNTAINS. THIS COLD FRONT APPROACHES FROM THE WEST TUESDAY
WITH MOISTURE INCREASING AND CIGS LOWERING TOWARD MVFR LEVELS
ESPCLY LATER IN THE DAY WHEN A FEW BANDS OF SHOWERS APPEAR
POSSIBLE.
&&
.CLIMATE...
HERE ARE THE RECORDS FOR MAY 9TH AND OBSERVED HIGHS THROUGH 5PM.
STATION RECORD/YEAR OBSERVED HIGH
ROA 92/1963 88
LYH 94/1936 88
DAN 94/1963 89
BCB 85/1966 81
BLF 84/2005 84 **TIED FOR MAY 9TH**
LWB 82/2000 80
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB/WP
NEAR TERM...AMS/WP
SHORT TERM...KM
LONG TERM...KM
AVIATION...RAB/WP
CLIMATE...WP/AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
334 PM EDT FRI MAY 9 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL BE MOVING TOWARD THE CENTRAL APPALACHIANS
SATURDAY...ORIENTING ITSELF WEST TO EAST ACROSS THE OHIO VALLEY TO
MID ATLANTIC SUNDAY. RIDGE BUILDS SUNDAY INTO MONDAY SENDING THIS
FRONT NORTH. A STRONGER COLD FRONT ARRIVES IN THE WEDNESDAY TIME
FRAME...SLOWING DOWN AS IT MOVES EAST OF THE APPALACHIANS INTO
LATE WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 315 PM EDT FRIDAY...
A FEW SHOWERS AND STORMS POPPING UP AS FORECASTED BY THE HIGH-RES
MODELS ACROSS THE NC MTNS INTO THE NEW RIVER VALLEY OF VA AND SE WV.
ANOTHER NARROW PATCH ALSO OCCURRING FROM INT-WEST OF CLT.
SHORTWAVE ENERGY ACROSS TN PER LATEST RAP MODEL SHOULD HEAD NE INTO
THE CENTRAL APPALACHIANS BY DUSK WITH INCREASED THREAT OF SHOWERS
AND STORMS IN THE WESTERN CWA. INSTABILITY IN THE EAST IS HIGHER PER
MORE SUN EARLIER RAISING SBCAPES TO 500-1000 J/KG...WITH DCAPES OVER
1000 J/KG GIVEN DRIER AIR IN THE LOW LVLS. SOME OF THE SHOWERS OR
STORMS COULD PRODUCE GUSTY WINDS BUT OVERALL WIND ENERGY IS WEAK
COMPARED TO FURTHER ACROSS THE WRN OHIO VALLEY.
THE THREAT OF SHOWERS WILL DIMINISH AFTER MIDNIGHT THOUGH ENOUGH LOW
LVL CONVERGENCE WITH SW FLOW ALOFT AND APPROACHING FRONT INTO THE
OHIO VALLEY TO KEEP SOME CHANCE IN OVER THE MTNS OVERNIGHT.
MODELS SHOWING SHORTWAVE PUSHING NE ACROSS CENTRAL NC OVERNIGHT
WHICH COULD PRODUCE A SHOWER OR TWO OUT EAST. THE BETTER THREAT
ARRIVES ACROSS THE REGION SATURDAY AND ESPECIALLY CLOSER TO THE
FRONT AND UPPER SUPPORT PUSHING ACROSS THE OHIO VALLEY INTO MID
ATLANTIC. KEPT POPS IN THE LIKELY RANGE MAINLY WEST OF I-81 IN
VIRGINIA...AND ACROSS THE NC MTNS TO LOWER CHANCES IN THE PIEDMONT.
WITH PLENTY OF CLOUDS TONIGHT....AND HUMIDITY INCREASING...TEMPS
SHOULD DROP INTO THE MID TO UPPER 50S MOUNTAINS TO LOWER TO MID 60S
EAST.
SATURDAY WILL BE COOLER WITH PLENTY OF CLOUD COVER. SOME SUNSHINE
COULD BREAK OUT ACROSS THE EAST IN THE AFTERNOON. OVERALL LOOKING AT
HIGHS FROM THE LOWER 70S MOUNTAINS TO NEAR 80 EAST.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 200 PM EDT FRIDAY...
WEAK BOUNDARY SETTLES NEAR THE REGION SATURDAY...WITH UPPER LEVEL
DISTURBANCES/JET STREAK ADDING TO LIFT. MOST OF THE SHOWERS AND
STORMS WILL BE DIURNAL IN NATURE AND ENDING SATURDAY NIGHT.
SUMMERLIKE PATTERN CONTINUES THROUGH THE WEEKEND WITH LESS COVERAGE
ON SUNDAY...BUT STILL LATE DAY STORMS IN THE WEST WITH SURFACE
CONVERGENCE ALONG THE MOUNTAINS. EVEN LESS OF A CHANCE ON MONDAY AS
RIDGE BUILDS AND HEIGHTS RISE SLIGHTLY...WASHING OUT OR PUSHING
NORTH WHATEVER BOUNDARY REMAINS FROM THE WEEKEND. MAX T WILL BE
HIGHLY DEPENDENT ON WHAT SITES GET HIT WITH STORMS...BUT H85 TEMPS
WILL RISE BACK FROM 16-18C SUNDAY AND MONDAY...AFTER SOMEWHAT COOLER
VALUES ON SATURDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 200 PM EDT FRIDAY...
PHASED FULL LATITUDE TROUGH DEVELOPING ALONG THE CONTINENTAL DIVIDE
ON MONDAY...WILL MOVE EAST AND LOOKS TO BE FORMIDABLE ENOUGH TO
DISLODGE THE STRONG UPPER RIDGE AND CHANGE THE PATTERN THROUGH THE
MIDDLE ATLANTIC AND SOUTHEAST. WEDNESDAY NIGHT LOOKS TO BE THE BEST
TIMEFRAME FOR THE STRONG COLD FRONT ASSOCIATED WITH THIS TROUGH TO
CROSS OUR REGION...WITH MORE WIDESPREAD STORMS LATE WED AND WED
NIGHT. WITH THE UPPER RIDGE NEARLY CLOSED OFF OVERHEAD ON
TUESDAY...CHCS OF STORMS MAY BE THE SMALLEST THAT DAY...ALTHOUGH
STILL CAN`T RULE OUT ISOLATED THUNDERSTORMS ANCHORED TO THE HIGHEST
PEAKS...ESPECIALLY WESTERN GREENBRIER. H85 TEMPS MAY FALL TO 5C
ACROSS THE REGION BY LATE WEEK BEHIND THE FRONT...WHICH WILL BE
QUITE AN IMPRESSIVE COOL DOWN CONSIDERING THE STRING OF 80F HIGHS
EXPECTED THIS WEEKEND AND MUCH OF THE UPCOMING WEEK. THE AIRMASS IS
SO COLD ALOFT THAT THERE MAY BE SOME INSTABILITY SHOWERS IN THE
AFTERNOON LATE WEEK OR NEXT WEEKEND...WITH THE MODELS TYPICALLY POOR
AT PREDICTING QPF THIS MANY DAYS AWAY IN THIS SETUP.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AS OF 140 PM EDT FRIDAY...
WILL EXPERIENCE VFR CONDITIONS THROUGH THE AFTERNOON INTO THE
EVENING. ISOLATED TO SCATTERED SHOWERS ALONG WITH A THUNDERSTORM
COULD IMPACT BCB/BLF/LWB THIS AFTERNOON INTO ROANOKE LATE
AFTERNOON. CONFIDENCE NOT HIGH ENOUGH FOR PREDOMINANT THUNDER...AS
INSTABILITY AND COVERAGE NOT ALL THAT HIGH.
ISSUE TONIGHT WILL BE THE COVERAGE OF RAIN SHOWERS AND EFFECT ON
CIGS AND VSBYS. ATTM...MODELS AND FORECAST SOUNDINGS SUGGEST
LIMITED THREAT OF SUB VFR CIGS/VSBYS THOUGH MOISTENING OF THE
AIRMASS MAY FAVOR SOME FOG IN THE VALLEYS AROUND BCB/LWB/DAN. WILL
LEAVE OUT FOR NOW. SHOULD BE A LULL IN PRECIP OVERNIGHT.
FRONT APPEARS TO BE STAYING NORTHWEST OF US INTO SATURDAY AS UPPER
LEVELS ENERGY SHEARS OUT TO THE NORTHEAST. WILL SEE SCATTERED
TO NUMEROUS COVERAGE ACROSS BY LATE SAT MORNING INTO THE AFTERNOON
MAINLY WEST OF THE BLUE RIDGE.
GUSTY SW WINDS THIS AFTERNOON TAPER OFF THIS EVENING THEN KICK UP
AGAIN LATE SAT MORNING...GENERALLY GUSTS AROUND 15-25 KNOTS.
LIKELIHOOD FOR SUB-VFR AT TIMES SATURDAY AFTERNOON WITH SHRA/TSRA
AHEAD OF THE FRONT MOVING SLOWLY EAST AND DEEPER MOISTURE IN
PLACE. BOUNDARY MAY WASH OUT UPON CROSSING THE AREA OR STALL JUST
OFF TO THE WEST BY SUNDAY WITH MAINLY VFR CONDITIONS EXPECTED
OUTSIDE OF OCNL MVFR IN MAINLY ISOLATED MOUNTAIN SHOWERS AS
LEFTOVER MOISTURE APPEARS QUITE SHALLOW. RIDGE OFFSHORE
STRENGTHENS AGAIN ON MONDAY AHEAD OF ANOTHER FRONT TO THE WEST
WITH MAINLY VFR EXCLUDING PERHAPS BRIEF MVFR IN A LATE DAY SHRA
ESPCLY MOUNTAINS. THIS COLD FRONT APPROACHES FROM THE WEST TUESDAY
WITH MOISTURE INCREASING AND CIGS LOWERING TOWARD MVFR LEVELS
ESPCLY LATER IN THE DAY WHEN A FEW BANDS OF SHOWERS APPEAR
POSSIBLE.
&&
.CLIMATE...
ANOTHER VERY WARM DAY ALREADY. CLOUDS AND SHOWERS MAY LIMIT TEMPS
FROM RISING MUCH MORE IN THE WEST BUT STILL POSSIBILITY EXISTS FOR
RECORD HIGHS AT BLF/BCB/LWB. HERE ARE THE RECORDS FOR MAY 9TH AND
CURRENT FORECAST HIGHS.
STATION CURRENT RECORD/YEAR FORECAST HIGH
ROA 92/1963 87
LYH 94/1936 88
DAN 94/1963 90
BCB 85/1966 84
BLF 84/2005 84
LWB 82/2000 83
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB/WP
NEAR TERM...WP
SHORT TERM...KM
LONG TERM...KM
AVIATION...RAB/WP
CLIMATE...WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
148 PM EDT FRI MAY 9 2014
.SYNOPSIS...
HIGH PRESSURE NOW OVER THE SOUTHEAST COAST WILL PUMP MOISTURE UP
OUR WAY THIS AFTERNOON IN ADVANCE OF A FRONT. THIS SYSTEM HEADS
OUT BY SATURDAY NIGHT WITH ANOTHER UPPER HIGH MOVING IN FOR SUNDAY
AND MONDAY. A STRONG FRONT ARRIVES IN THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 1220 PM EDT FRIDAY...
CU FIELD INCREASING OVER THE AREA...WITH SOME VERTICAL EXTENT TO
SOME. LATEST RUC MESOANLYSIS PER SPC PAGE SHOWING SBCAPES ABOVE
500 J/KG OVER THE SOUTHEAST BUT REMAINING LOWER IN THE MOUNTAINS.
HIGH-RES MODELS SHOW SHOWERS DEVELOPING ACROSS THE SRN BLUE RIDGE
INTO THE WV MTNS THROUGH MID AFTERNOON WITH BETTER COVERAGE OVER
THE MOUNTAINS AFTER 4-5 PM AS MID LEVEL VORT MOVES FROM TN TO THE
CENTRAL APPALACHIANS. WILL KEEP POPS IN THE CHANCE RANGE...HIGHER
IN THE FAR WEST. EXPECTING LESS THREAT IN THE EAST ALTHOUGH GIVEN
WARMER TEMPS...ISOLATED THUNDERSTORMS ARE POSSIBLE AFTER 4 PM.
RAISED HIGHS...MAINLY EAST OF THE BLUE RIDGE AS MORE SUNSHINE
OCCURRING AND TEMPS WERE ALREADY RUNNING ABOUT 3-6 DEGREES WARMER
THAN FORECAST AT NOON. SO LOOKING AT AROUND 90 SOUTHSIDE VA/NW NC
PIEDMONT. RECORDS ARE POSSIBLE MAINLY THE MOUNTAINS. SEE CLIMATE
SECTION BELOW. AS THE SHOWERS AND STORMS FORM...EXPECT TEMPS TO
COOL SOME.
PREVIOUS VALID DISCUSSION...
FOCUS THROUGH THE NEAR TERM WILL BE ON INCREASING CHANCES FOR
CONVECTION INTO SATURDAY ASSOCIATED WITH AN APPROACHING COLD
FRONT AND UPPER TROUGH. THE UPPER TROUGH...THE SAME ONE THAT HAS
ASSOCIATED WITH MORE WIDESPREAD SEVERE THUNDERSTORMS IN THE
MIDWEST/SOUTHERN PLAINS...WILL SHIFT NORTHEASTWARD TOWARD THE
GREAT LAKES AND WEAKEN/SHEAR OUT CONSIDERABLY AS IT APPROACHES THE
MID-ATLANTIC AND THE UPPER RIDGE IN PLACE ALONG THE EAST COAST.
THE BROOKS-CRAVEN SIGNIFICANT SVR PARAMETER...SUGGESTS THAT THE
THREAT FOR THUNDERSTORMS LATE THIS AFTERNOON/EVENING IS MARGINAL
AT BEST...WITH MOST VALUES 5000 OR LESS.
AS THE UPPER TROUGH MOVES ACROSS THE REGION OVERNIGHT/EARLY SAT
AND THE LOW-LEVEL AIR MASS CONTINUES TO MOISTEN...EXPECT SCATTERED
SHOWERS TO CONTINUE OVERNIGHT/EARLY SAT...ESPECIALLY WEST OF THE
BLUE RIDGE WHERE THE BEST FORCING WILL REMAIN. SATURDAY...THE
ENTIRE CWA REMAINS UNDER AN INCREASINGLY MOIST/MARGINALLY UNSTABLE
AIR MASS WITH CONSIDERABLE CONVECTIVE DEBRIS IN PLACE. THE MAIN
UPPER SUPPORT HAS PASSED BY TO THE NORTH...BUT BROAD WSW
FLOW/TROUGHING REMAINS IN PLACE ACROSS MUCH OF THE U.S. WEAK
SUBTLE IMPULSES EMBEDDED WITHIN THE UPPER FLOW WILL IMPINGE ON THE
MORE UNSTABLE/MOIST ATMOSPHERE...PWS NEAR 1.5 BY SAT
AFTERNOON...AND LIKELY RESULT IN BETTER COVERAGE/POTENTIAL FOR
SHRA/TSRA AS COMPARED TO TODAY...EVEN WITH BETTER FORCING IN PLACE
TODAY. ALMOST SOMEWHAT OF A TYPICAL SUMMER PATTERN...ALBEIT WITH
BETTER DYNAMICS/FLOW ALOFT THAN WOULD BE SEEN ON A TYPICAL SUMMER
PULSE THUNDERSTORM DAY. THUS...HAVE OPTED FOR HIGH CHC/LIKELY POPS
FOR SHRA/TSRA SAT AFTERNOON MUCH OF THE CWA...WITH THE BEST
CHANCES WEST OF THE BLUE RIDGE FURTHEST AWAY FROM THE UPPER
RIDGE.
QPF SHOULD NOT BE AN ISSUE THROUGH THE NEAR TERM...WITH AMOUNTS
NEAR 1/2 INCH WEST TO LESS THAN 1/4 INCH FAR SOUTHEAST. ANY
FLOODING ISSUES SHOULD BE CONFINED TO NEXT WEEK AFTER SEVERAL DAYS
OF SHRA/TSRA HAVE IMPACTED THE REGION...NOT WITH THIS FIRST ROUND.
TEMPS WILL REMAIN QUITE WARM TODAY...ESPECIALLY IN THE EAST. MIN
TEMPS TONIGHT SHOULD REMAIN VERY MILD...FROM THE UPPER 50S
WEST/WETTER AREAS TO THE MID 60S SOUTHEAST PARTS OF THE PIEDMONT.
EVEN MORE CLOUDS AND BETTER SHRA CHANCES SHOULD YIELD MAX TEMPS
SAT MOSTLY IN THE 70S...WITH 60S POSSIBLE IN THE MOUNTAINS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 345 AM EDT FRIDAY...
SHOWER AND THUNDERSTORM ACTIVITY WILL GRADUALLY DIMINISH SATURDAY
EVENING AS THE UPPER LEVEL DISTURBANCE TRIGGERING THE CONVECTION
EARLIER IN THE DAY PUSHES TOWARD THE COAST...ALLOWING WINDS TO SHIFT
NORTHWESTERLY AND DOWNSLOPE. OVERNIGHT TEMPERATURES WILL BE SLIGHTLY
COOLER COMPARED TO THE NIGHT BEFORE...BUT WILL STILL HOLD IN THE 50S
FOR MOST LOCATIONS.
UPPER LEVEL RIDGING WILL BECOME INCREASINGLY AMPLIFIED ALONG THE
ATLANTIC COAST SUNDAY AS A DEEP UPPER TROUGH DIGS ACROSS THE
INTERMOUNTAIN WEST. THE BUILDING RIDGE WILL CAUSE THE NORTHWESTERLY
WINDS TO RETURN SOUTHWESTERLY EARLY IN THE DAY..RESUMING THE FLOW OF
MOIST HUMID AIR INTO THE MID ATLANTIC. REGARDLESS...INSTABILITY WILL
BE MORE LIMITED ON SUNDAY COMPARED TO SATURDAY...AND WHILE A FEW
SHOWERS AND THUNDERSTORMS ARE EXPECTED...BELIEVE THEY WILL BE SPOTTY
AND DISORGANIZED IN NATURE...AND WILL DIMINISH QUICKLY TOWARD
SUNSET. OTHERWISE...PARTLY CLOUDY SKIES WILL ALLOW ENOUGH SUNSHINE
TO REACH THE SURFACE TO PUSH AFTERNOON TEMPERATURES INTO THE MID 80S
EAST OF THE BLUE RIDGE...WHILE UPPER 70S TO LOW 80S CAN BE EXPECTED
FOR THE MOUNTAINS. SUNDAY NIGHT WILL BE MILD AND SOMEWHAT
MUGGY...WITH PATCHY FOG LIKELY ACROSS THE REGION. LOWS WILL RANGE
FROM THE UPPER 50S TO THE LOW 60S FOR MOST LOCATIONS.
THE DEEP UPPER TROUGH AND ITS ASSOCIATED COLD FRONT WILL SHIFT EAST
ON MONDAY TO PASS OVER THE PLAINS. RIDGING WILL STILL MAINTAIN ITS
INFLUENCE ALONG THE APPALACHIAN CHAIN...BUT MAY SEE A LITTLE MORE
INSTABILITY AS AFTERNOON TEMPERATURES CLIMB TO THE LOW 80S WEST AND
THE UPPER 80S EAST. MODELS ARE NOT INDICATING ANY SIGNIFICANT
DISTURBANCES PASSING ACROSS THE AREA...AND BELIEVE ANY SHOWER AND
THUNDERSTORM ACTIVITY WILL AGAIN BE SPOTTY AND DISORGANIZED. EXPECT
OVERNIGHT LOWS IN THE UPPER 50S TO THE MID 60S...WITH MORE PATCHY
FOG POSSIBLE...ESPECIALLY IN AREAS THAT EXPERIENCE RAINFALL.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 145 PM EDT THURSDAY
WHILE LONG RANGE MODELS ARE STILL SHOWING SOME TIMING DIFFERENCES...
THE OVERALL TREND IS TO KEEP THE APPROACHING COLD FRONT MOVING
SLOWER INTO MIDWEEK. THIS WILL KEEP OUR AREA IN THE WARM SECTOR
LONGER...WITH INCREASED CHANCES OF SHOWERS AND STORMS TUESDAY AND
WEDNESDAY. WEDNESDAY STILL LOOKS TO BE THE WETTER OF THE TWO DAYS AS
FRONT REACHES THE CWA. MODELS/WPC SHOW FRONT EDGING EAST TO THE
PIEDMONT THURSDAY WITH BEST THREAT FOR CONVECTION IN THE PIEDMONT.
TEMPERATURES BY MIDWEEK SHOULD START TO LOWER BUT STILL LOOKING
HUMID UNTIL FRONT REACHES THE COAST BY THURSDAY NIGHT AND FRIDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 140 PM EDT FRIDAY...
WILL EXPERIENCE VFR CONDITIONS THROUGH THE AFTERNOON INTO THE
EVENING. ISOLATED TO SCATTERED SHOWERS ALONG WITH A THUNDERSTORM
COULD IMPACT BCB/BLF/LWB THIS AFTERNOON INTO ROANOKE LATE
AFTERNOON. CONFIDENCE NOT HIGH ENOUGH FOR PREDOMINANT THUNDER...AS
INSTABILITY AND COVERAGE NOT ALL THAT HIGH.
ISSUE TONIGHT WILL BE THE COVERAGE OF RAIN SHOWERS AND EFFECT ON
CIGS AND VSBYS. ATTM...MODELS AND FORECAST SOUNDINGS SUGGEST
LIMITED THREAT OF SUB VFR CIGS/VSBYS THOUGH MOISTENING OF THE
AIRMASS MAY FAVOR SOME FOG IN THE VALLEYS AROUND BCB/LWB/DAN. WILL
LEAVE OUT FOR NOW. SHOULD BE A LULL IN PRECIP OVERNIGHT.
FRONT APPEARS TO BE STAYING NORTHWEST OF US INTO SATURDAY AS UPPER
LEVELS ENERGY SHEARS OUT TO THE NORTHEAST. WILL SEE SCATTERED
TO NUMEROUS COVERAGE ACROSS BY LATE SAT MORNING INTO THE AFTERNOON
MAINLY WEST OF THE BLUE RIDGE.
GUSTY SW WINDS THIS AFTERNOON TAPER OFF THIS EVENING THEN KICK UP
AGAIN LATE SAT MORNING...GENERALLY GUSTS AROUND 15-25 KNOTS.
LIKELIHOOD FOR SUB-VFR AT TIMES SATURDAY AFTERNOON WITH SHRA/TSRA
AHEAD OF THE FRONT MOVING SLOWLY EAST AND DEEPER MOISTURE IN
PLACE. BOUNDARY MAY WASH OUT UPON CROSSING THE AREA OR STALL JUST
OFF TO THE WEST BY SUNDAY WITH MAINLY VFR CONDITIONS EXPECTED
OUTSIDE OF OCNL MVFR IN MAINLY ISOLATED MOUNTAIN SHOWERS AS
LEFTOVER MOISTURE APPEARS QUITE SHALLOW. RIDGE OFFSHORE
STRENGTHENS AGAIN ON MONDAY AHEAD OF ANOTHER FRONT TO THE WEST
WITH MAINLY VFR EXCLUDING PERHAPS BRIEF MVFR IN A LATE DAY SHRA
ESPCLY MOUNTAINS. THIS COLD FRONT APPROACHES FROM THE WEST TUESDAY
WITH MOISTURE INCREASING AND CIGS LOWERING TOWARD MVFR LEVELS
ESPCLY LATER IN THE DAY WHEN A FEW BANDS OF SHOWERS APPEAR
POSSIBLE.
&&
.CLIMATE...
ANOTHER VERY WARM DAY ALREADY. CLOUDS AND SHOWERS MAY LIMIT TEMPS
FROM RISING MUCH MORE IN THE WEST BUT STILL POSSIBILITY EXISTS FOR
RECORD HIGHS AT BLF/BCB/LWB. HERE ARE THE RECORDS FOR MAY 9TH AND
CURRENT FORECAST HIGHS.
STATION CURRENT RECORD/YEAR FORECAST HIGH
ROA 92/1963 87
LYH 94/1936 88
DAN 94/1963 90
BCB 85/1966 84
BLF 84/2005 84
LWB 82/2000 83
&&
.EQUIPMENT...
BLACKSBURG RADAR NOW WORKING AS AC UNIT FIXED. MORE WORK ON THE
RADAR IS PLANNED MONDAY NEXT WEEK WEATHER PERMITTING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB/WP
NEAR TERM...RAB/WP
SHORT TERM...NF
LONG TERM...NF/WP
AVIATION...RAB/WP
CLIMATE...WP
EQUIPMENT...WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1245 PM EDT FRI MAY 9 2014
.SYNOPSIS...
HIGH PRESSURE NOW OVER THE SOUTHEAST COAST WILL PUMP MOISTURE UP
OUR WAY THIS AFTERNOON IN ADVANCE OF A FRONT. THIS SYSTEM HEADS
OUT BY SATURDAY NIGHT WITH ANOTHER UPPER HIGH MOVING IN FOR SUNDAY
AND MONDAY. A STRONG FRONT ARRIVES IN THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 1220 PM EDT FRIDAY...
CU FIELD INCREASING OVER THE AREA...WITH SOME VERTICAL EXTENT TO
SOME. LATEST RUC MESOANLYSIS PER SPC PAGE SHOWING SBCAPES ABOVE
500 J/KG OVER THE SOUTHEAST BUT REMAINING LOWER IN THE MOUNTAINS.
HIGH-RES MODELS SHOW SHOWERS DEVELOPING ACROSS THE SRN BLUE RIDGE
INTO THE WV MTNS THROUGH MID AFTERNOON WITH BETTER COVERAGE OVER
THE MOUNTAINS AFTER 4-5 PM AS MID LEVEL VORT MOVES FROM TN TO THE
CENTRAL APPALACHIANS. WILL KEEP POPS IN THE CHANCE RANGE...HIGHER
IN THE FAR WEST. EXPECTING LESS THREAT IN THE EAST ALTHOUGH GIVEN
WARMER TEMPS...ISOLATED THUNDERSTORMS ARE POSSIBLE AFTER 4 PM.
RAISED HIGHS...MAINLY EAST OF THE BLUE RIDGE AS MORE SUNSHINE
OCCURRING AND TEMPS WERE ALREADY RUNNING ABOUT 3-6 DEGREES WARMER
THAN FORECAST AT NOON. SO LOOKING AT AROUND 90 SOUTHSIDE VA/NW NC
PIEDMONT. RECORDS ARE POSSIBLE MAINLY THE MOUNTAINS. SEE CLIMATE
SECTION BELOW. AS THE SHOWERS AND STORMS FORM...EXPECT TEMPS TO
COOL SOME.
PREVIOUS VALID DISCUSSION...
FOCUS THROUGH THE NEAR TERM WILL BE ON INCREASING CHANCES FOR
CONVECTION INTO SATURDAY ASSOCIATED WITH AN APPROACHING COLD
FRONT AND UPPER TROUGH. THE UPPER TROUGH...THE SAME ONE THAT HAS
ASSOCIATED WITH MORE WIDESPREAD SEVERE THUNDERSTORMS IN THE
MIDWEST/SOUTHERN PLAINS...WILL SHIFT NORTHEASTWARD TOWARD THE
GREAT LAKES AND WEAKEN/SHEAR OUT CONSIDERABLY AS IT APPROACHES THE
MID-ATLANTIC AND THE UPPER RIDGE IN PLACE ALONG THE EAST COAST.
THE BROOKS-CRAVEN SIGNIFICANT SVR PARAMETER...SUGGESTS THAT THE
THREAT FOR THUNDERSTORMS LATE THIS AFTERNOON/EVENING IS MARGINAL
AT BEST...WITH MOST VALUES 5000 OR LESS.
AS THE UPPER TROUGH MOVES ACROSS THE REGION OVERNIGHT/EARLY SAT
AND THE LOW-LEVEL AIR MASS CONTINUES TO MOISTEN...EXPECT SCATTERED
SHOWERS TO CONTINUE OVERNIGHT/EARLY SAT...ESPECIALLY WEST OF THE
BLUE RIDGE WHERE THE BEST FORCING WILL REMAIN. SATURDAY...THE
ENTIRE CWA REMAINS UNDER AN INCREASINGLY MOIST/MARGINALLY UNSTABLE
AIR MASS WITH CONSIDERABLE CONVECTIVE DEBRIS IN PLACE. THE MAIN
UPPER SUPPORT HAS PASSED BY TO THE NORTH...BUT BROAD WSW
FLOW/TROUGHING REMAINS IN PLACE ACROSS MUCH OF THE U.S. WEAK
SUBTLE IMPULSES EMBEDDED WITHIN THE UPPER FLOW WILL IMPINGE ON THE
MORE UNSTABLE/MOIST ATMOSPHERE...PWS NEAR 1.5 BY SAT
AFTERNOON...AND LIKELY RESULT IN BETTER COVERAGE/POTENTIAL FOR
SHRA/TSRA AS COMPARED TO TODAY...EVEN WITH BETTER FORCING IN PLACE
TODAY. ALMOST SOMEWHAT OF A TYPICAL SUMMER PATTERN...ALBEIT WITH
BETTER DYNAMICS/FLOW ALOFT THAN WOULD BE SEEN ON A TYPICAL SUMMER
PULSE THUNDERSTORM DAY. THUS...HAVE OPTED FOR HIGH CHC/LIKELY POPS
FOR SHRA/TSRA SAT AFTERNOON MUCH OF THE CWA...WITH THE BEST
CHANCES WEST OF THE BLUE RIDGE FURTHEST AWAY FROM THE UPPER
RIDGE.
QPF SHOULD NOT BE AN ISSUE THROUGH THE NEAR TERM...WITH AMOUNTS
NEAR 1/2 INCH WEST TO LESS THAN 1/4 INCH FAR SOUTHEAST. ANY
FLOODING ISSUES SHOULD BE CONFINED TO NEXT WEEK AFTER SEVERAL DAYS
OF SHRA/TSRA HAVE IMPACTED THE REGION...NOT WITH THIS FIRST ROUND.
TEMPS WILL REMAIN QUITE WARM TODAY...ESPECIALLY IN THE EAST. MIN
TEMPS TONIGHT SHOULD REMAIN VERY MILD...FROM THE UPPER 50S
WEST/WETTER AREAS TO THE MID 60S SOUTHEAST PARTS OF THE PIEDMONT.
EVEN MORE CLOUDS AND BETTER SHRA CHANCES SHOULD YIELD MAX TEMPS
SAT MOSTLY IN THE 70S...WITH 60S POSSIBLE IN THE MOUNTAINS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 345 AM EDT FRIDAY...
SHOWER AND THUNDERSTORM ACTIVITY WILL GRADUALLY DIMINISH SATURDAY
EVENING AS THE UPPER LEVEL DISTURBANCE TRIGGERING THE CONVECTION
EARLIER IN THE DAY PUSHES TOWARD THE COAST...ALLOWING WINDS TO SHIFT
NORTHWESTERLY AND DOWNSLOPE. OVERNIGHT TEMPERATURES WILL BE SLIGHTLY
COOLER COMPARED TO THE NIGHT BEFORE...BUT WILL STILL HOLD IN THE 50S
FOR MOST LOCATIONS.
UPPER LEVEL RIDGING WILL BECOME INCREASINGLY AMPLIFIED ALONG THE
ATLANTIC COAST SUNDAY AS A DEEP UPPER TROUGH DIGS ACROSS THE
INTERMOUNTAIN WEST. THE BUILDING RIDGE WILL CAUSE THE NORTHWESTERLY
WINDS TO RETURN SOUTHWESTERLY EARLY IN THE DAY..RESUMING THE FLOW OF
MOIST HUMID AIR INTO THE MID ATLANTIC. REGARDLESS...INSTABILITY WILL
BE MORE LIMITED ON SUNDAY COMPARED TO SATURDAY...AND WHILE A FEW
SHOWERS AND THUNDERSTORMS ARE EXPECTED...BELIEVE THEY WILL BE SPOTTY
AND DISORGANIZED IN NATURE...AND WILL DIMINISH QUICKLY TOWARD
SUNSET. OTHERWISE...PARTLY CLOUDY SKIES WILL ALLOW ENOUGH SUNSHINE
TO REACH THE SURFACE TO PUSH AFTERNOON TEMPERATURES INTO THE MID 80S
EAST OF THE BLUE RIDGE...WHILE UPPER 70S TO LOW 80S CAN BE EXPECTED
FOR THE MOUNTAINS. SUNDAY NIGHT WILL BE MILD AND SOMEWHAT
MUGGY...WITH PATCHY FOG LIKELY ACROSS THE REGION. LOWS WILL RANGE
FROM THE UPPER 50S TO THE LOW 60S FOR MOST LOCATIONS.
THE DEEP UPPER TROUGH AND ITS ASSOCIATED COLD FRONT WILL SHIFT EAST
ON MONDAY TO PASS OVER THE PLAINS. RIDGING WILL STILL MAINTAIN ITS
INFLUENCE ALONG THE APPALACHIAN CHAIN...BUT MAY SEE A LITTLE MORE
INSTABILITY AS AFTERNOON TEMPERATURES CLIMB TO THE LOW 80S WEST AND
THE UPPER 80S EAST. MODELS ARE NOT INDICATING ANY SIGNIFICANT
DISTURBANCES PASSING ACROSS THE AREA...AND BELIEVE ANY SHOWER AND
THUNDERSTORM ACTIVITY WILL AGAIN BE SPOTTY AND DISORGANIZED. EXPECT
OVERNIGHT LOWS IN THE UPPER 50S TO THE MID 60S...WITH MORE PATCHY
FOG POSSIBLE...ESPECIALLY IN AREAS THAT EXPERIENCE RAINFALL.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 145 PM EDT THURSDAY
WHILE LONG RANGE MODELS ARE STILL SHOWING SOME TIMING DIFFERENCES...
THE OVERALL TREND IS TO KEEP THE APPROACHING COLD FRONT MOVING
SLOWER INTO MIDWEEK. THIS WILL KEEP OUR AREA IN THE WARM SECTOR
LONGER...WITH INCREASED CHANCES OF SHOWERS AND STORMS TUESDAY AND
WEDNESDAY. WEDNESDAY STILL LOOKS TO BE THE WETTER OF THE TWO DAYS AS
FRONT REACHES THE CWA. MODELS/WPC SHOW FRONT EDGING EAST TO THE
PIEDMONT THURSDAY WITH BEST THREAT FOR CONVECTION IN THE PIEDMONT.
TEMPERATURES BY MIDWEEK SHOULD START TO LOWER BUT STILL LOOKING
HUMID UNTIL FRONT REACHES THE COAST BY THURSDAY NIGHT AND FRIDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 740 AM EDT FRIDAY...
VFR CIGS/VSBYS EXPECTED THROUGH THE TAF VALID PERIOD...DESPITE AN
APPROACHING WEATHER SYSTEM. HOWEVER...BKN-OVC HIGH-MID CLOUDS
WILL OVERSPREAD THE REGION THROUGHOUT THE DAY IN ADVANCE OF THE
CENTRAL U.S. UPPER TROUGH. SW SFC WINDS WILL BEGIN TO BRING GULF
MOISTURE INTO THE REGION BY MID DAY/EARLY AFTERNOON...WHICH SHOULD
BE REALIZED IN SCT HIGH BASED 050-060 CU...ESPECIALLY WEST OF THE
BLUE RIDGE AND MOST NOTABLY IN EASTERN WV. DRY SFC AIR WILL BE
SLOW TO MODIFY...SO NOT EXPECTING ANY CIGS BELOW 045 THROUGH 12Z
SAT...BUT WILL NEED TO WATCH EASTERN WV AREAS AS -SHRA LATE
TODAY/TONIGHT COULD POTENTIALLY RESULT IN LOWER CIGS...POSSIBLY
MVFR. MODELS SLIGHTLY FASTER ON ARRIVAL OF FRONTAL PCPN IN THE
WESTERN PARTS OF THE CWA LATE THIS AFTERNOON/EVENING...SO HAVE
INTRODUCED VCSH/-SHRA 20Z BLF/LWB TO AROUND 00Z ROA. PCPN WILL
LIKELY HAVE A HARD TIME SPREADING EAST OF THE BLUE RIDGE AS UPPER
SUPPORT WANES AND SHIFTS NORTH OF THE REGION IN SHEARING UPPER
TROUGH. THUS...HAVE NOT INTRODUCED PCPN YET FOR DAN AND ONLY
TEMPO P6SM -RA FOR LYH. INTRODUCED SOME MVFR IN -SHRA BR
BLF/LWB...BUT CONFIDENCE IN THIS IS LOW UNTIL LOWER LEVELS OF THE
ATMOSPHERE SATURATE. SHOULD SEE BETTER CHANCE FOR SHRA/TSRA ALL
AREAS...INCLUDING DAN/LYH/ROA SAT AFT 16Z. WINDS...LIGHT SW OR
CALM THROUGH 14Z...THEN SW ALL SITES AFT 14Z 8-12KTS WITH GUSTS TO
20-22KTS BLF/BCB/ROA/DAN FROM LATE MORNING THROUGH LATE AFTERNOON.
WINDS WILL DIMINISH TO 7KTS OR LESS AFT 00Z.
HIGH CONFIDENCE IN VFR CIGS/VSBYS THROUGH 20Z...THEN MEDIUM
CONFIDENCE IN CIGS/VSBYS...ESPECIALLY WEST OF THE BLUE RIDGE.
HIGH CONFIDENCE IN WIND DIR...MEDIUM TO HIGH CONFIDENCE IN WIND
SPD THROUGH THE TAF VALID PERIOD.
LOW CONFIDENCE IN ANY THUNDERSTORM POTENTIAL BLF/LWB/BCB LATE IN
THE DAY OR EARLY EVENING.
EXTENDED AVIATION DISCUSSION...
CONTINUED LIKELIHOOD FOR SUB-VFR AT TIMES SATURDAY WITH SHRA/TSRA
AHEAD OF THE FRONT MOVING SLOWLY EAST AND DEEPER MOISTURE IN
PLACE. BOUNDARY MAY WASH OUT UPON CROSSING THE AREA OR STALL JUST
OFF TO THE WEST BY SUNDAY WITH MAINLY VFR CONDITIONS EXPECTED
OUTSIDE OF OCNL MVFR IN MAINLY ISOLATED MOUNTAIN SHOWERS AS
LEFTOVER MOISTURE APPEARS QUITE SHALLOW. RIDGE OFFSHORE
STRENGTHENS AGAIN ON MONDAY AHEAD OF ANOTHER FRONT TO THE WEST
WITH MAINLY VFR EXCLUDING PERHAPS BRIEF MVFR IN A LATE DAY SHRA
ESPCLY MOUNTAINS. THIS COLD FRONT APPROACHES FROM THE WEST TUESDAY
WITH MOISTURE INCREASING AND CIGS LOWERING TOWARD MVFR LEVELS
ESPCLY LATER IN THE DAY WHEN A FEW BANDS OF SHOWERS APPEAR
POSSIBLE.
&&
.CLIMATE...
ANOTHER VERY WARM DAY ALREADY. CLOUDS AND SHOWERS MAY LIMIT TEMPS
FROM RISING MUCH MORE IN THE WEST BUT STILL POSSIBILITY EXISTS FOR
RECORD HIGHS AT BLF/BCB/LWB. HERE ARE THE RECORDS FOR MAY 9TH AND
CURRENT FORECAST HIGHS.
STATION CURRENT RECORD/YEAR FORECAST HIGH
ROA 92/1963 87
LYH 94/1936 88
DAN 94/1963 90
BCB 85/1966 84
BLF 84/2005 84
LWB 82/2000 83
&&
.EQUIPMENT...
BLACKSBURG RADAR NOW WORKING AS AC UNIT FIXED. MORE WORK ON THE
RADAR IS PLANNED MONDAY NEXT WEEK WEATHER PERMITTING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB/WP
NEAR TERM...RAB/WP
SHORT TERM...NF
LONG TERM...NF/WP
AVIATION...JH/RAB
CLIMATE...WP
EQUIPMENT...WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
302 PM CDT FRI MAY 9 2014
.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 302 PM CDT FRI MAY 9 2014
MAIN FORECAST CONCERNS THIS PERIOD...RETURNING SHRA/TSRA CHANCES SAT
AFTERNOON/NIGHT...TEMPERATURES THRU THE PERIOD.
DATA ANALYSIS AT 18Z HAD A BROAD AREA OF LOW PRESSURE CENTERED JUST
NORTHWEST OF LK SUPERIOR AND LIFTING RATHER QUICKLY NORTHEAST INTO
ONT. PRESSURE GRADIENT AROUND THE LOW REMAINED ACROSS MUCH OF MN/WI/
IA WITH BRISK SOUTHWEST TO NORTHWEST WINDS OF 15-25 MPH COMMON.
THESE WINDS USHERING IN COOLER AIR COMBINED WITH 925-850MB MOISTURE/
STRATUS CLOUDS WRAPPED AROUND BEHIND THE LOW MAKING FOR A MUCH
COOLER/GRAYER DAY THAN THURSDAY WAS ACROSS MOST OF THE REGION. -SHRA
WITH THE WRAP AROUND MOISTURE LIMITED TO THE NORTH HALF OF MN WHERE
THE MOISTURE WAS DEEPER TO ABOUT 700MB.
MODEL RUNS OF 09.12Z INITIALIZED WELL AND OFFER QUITE SIMILAR
SOLUTIONS FOR TONIGHT THRU SAT NIGHT AS ONE SHORTWAVE TROUGH EXITS
AND THE NEXT ONE QUICKLY MOVES IN/ACROSS THE UPPER MIDWEST LATE
SAT/SAT NIGHT. TREND IS A BIT STRONGER WITH THIS NEXT SHORTWAVE AS
IT MOVES INTO WESTERN SD/NEB BY 12Z SAT...THEN TOWARD A COMPROMISE
OF THE EARLIER RUNS AS IT MOVES INTO WESTERN MN BY 00Z SUN. BY 12Z
SUN TREND IS FOR MORE SHORTWAVE RIDGING OVER MN/IA/WI BEHIND THIS
DEPARTING WAVE...AND AHEAD OF STRONGER TROUGHING DIGGING INTO THE
CENTRAL/SOUTHERN ROCKIES. WITH THE TIGHTER CONSENSUS...SHORT-TERM
FCST CONFIDENCE IS GOOD THIS CYCLE.
IN THE SHORT TERM THE SFC-850MB LOW WILL LIFT RATHER QUICKLY TO NEAR
JAMES BAY BY 06Z WITH THE SFC RIDGE AXIS APPROACHING THE MS RIVER.
LOWER LEVEL RH PROGS DOING A DECENT JOB ON THE WRAP AROUND STRATUS
CLOUDS AT 18Z. WOULD EXPECT THESE CLOUDS TO CLEAR THE FCST AREA
RATHER QUICKLY THRU THE LATE AFTERNOON/EARLY EVENING WITH THE SFC-
850MB LOW EXITING AND APPROACH OF THE LOWER LEVEL RIDGE AXIS.
HOWEVER ONE FINAL PIECE OF SHORTWAVE ENERGY OVER NORTHWEST MN TO
ROTATE ACROSS NORTHERN WI THIS EVENING LOOKS TO DELAY THAT A BIT
ESPECIALLY OVER THE NORTHEAST END OF THE FCST AREA. A PERIOD OF
CLEAR SKIES/LIGHT WINDS EXPECTED LATER TONIGHT AS THE SFC-700MB
RIDGE AXIS MOVES BY. GIVEN THIS...THE COOL/GRAY DAY AND THE RECENT
RAINS...WILL HAVE TO WATCH FOR PATCHY FOG DEVELOPMENT LATE TONIGHT.
FOCUS SAT SHIFTS BACK TO THE WEST AND NEXT APPROACHING SHORTWAVE.
LOWER LEVEL WARM ADVECTION/MOISTURE TRANSPORT ALREADY ARRIVE SAT
MORNING...WITH THE 925-850MB WARM ADVECTION OUTPACING THE ARRIVAL OF
THE INCREASING MOISTURE IN THOSE LAYERS. SOME 700MB MOISTURE ARRIVES
EARLIER...BUT LITTLE IN THE WAY OF LIFT THRU 700MB SEEN UNTIL SAT
AFTERNOON. WILL LEAVE SAT MORNING DRY AND CONTINUED TO SPREAD THE
RAIN CHANCES INTO/ACROSS THE FCST AREA SAT AFTERNOON. STRONGER OF
THE LOW LEVEL FORCING/DEEPEST OF THE MOISTURE...PW VALUES AROUND
0.75 INCH...SPREADS ACROSS THE AREA SAT EVENING WITH THE MID LEVEL
TROUGH AXIS. CARRIED HIGHEST SHRA/TSRA CHANCES OF 40-60 PERCENT SAT
EVENING...TAPERING DOWN AFTER MIDNIGHT AS THE 925-500MB TROUGH AXIS
PASSES AND MOISTURE/LIFT DECREASE. MODEL SOUNDINGS SHOWING SKINNY
CAPE PROFILES OF 100-500 J/KG BETWEEN ROUGHLY 700-350MB SAT
AFTERNOON/EVENING...DIMINISHING LATE SAT NIGHT. INCLUDED TSRA
CHANCES SAT AFTERNOON/NIGHT. USED A BLEND OF THE NUMERICAL GUIDANCE
LOWS/HIGHS FOR TONIGHT THRU SAT NIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 302 PM CDT FRI MAY 9 2014
MAIN FORECAST CONCERNS FOR SUN THRU MON NIGHT...SHRA/TSRA CHANCES
MUCH OF THE PERIOD AND RAIN AMOUNTS.
09.12Z MODELS IN GOOD AGREEMENT AS STRONG TROUGHING/SHORTWAVE ENERGY
MOVES THRU THE ROCKIES SUN THEN BEGINS TO EJECT INTO THE CENTRAL/
SOUTHERN PLAINS SUN NIGHT. TREND IS TOWARD SLOWER/STRONGER OF THE
EARLIER MODELS WITH THIS TROUGH SUN/SUN NIGHT. TREND MON/MON NIGHT
AS THE TROUGH MOVES INTO THE CENTRAL CONUS IS TOWARD A COMPROMISE OF
THE EARLIER RUNS WITH ECMWF SPEEDING UP AND GFS SLOWING DOWN. CAN-
GEM REMAINS A SLOW LOOKING OUTLIER WITH THE TROUGH AT 12Z TUE. THE
TIGHTENING ECMWF/GFS CONSENSUS FOR SUN-MON NIGHT LEADS TO AVERAGE TO
GOOD CONFIDENCE IN THIS FCST PERIOD.
BREAK FROM THE SHRA/TSRA CHANCES BEHIND THE SAT/SAT NIGHT SYSTEM
CONTINUES TO LOOK BRIEF. 925-700MB WARM ADVECTION/ISENTROPIC LIFT
AND MOISTURE TRANSPORT...AHEAD OF THE NEXT CO/KS LEE LOW IN RESPONSE
TO THE STRONG TROUGHING COMING THRU THE ROCKIES...ALREADY SPREADS
NORTHEAST INTO THE UPPER MIDWEST SUN MORNING. NAM WITH MORE
SHORTWAVE ENERGY RIPPLING OUT OF THE WESTERN TROUGH AND INTO THE
REGION SUN AND FLATTER/FASTER 850-500MB FLOW. NAM THUS STREAMS THE
MOISTURE/LIFT NORTHEAST MORE QUICKLY AND SPREADS PRECIP ACROSS THE
FCST AREA ALREADY SUN MORNING. INITIALLY QUITE A BIT OF DRY AIR
BETWEEN 800-600MB TO OVERCOME BEFORE PRECIP CHANCES WOULD INCREASE
WITH NAM LOOKING TOO FAST WITH MOISTURE/PRECIP INTO THE AREA. SIDED
WITH THE SLOWER GFS/ECMWF/CAN-GEM CONSENSUS AND ONLY SPREAD 20-40
PERCENT SHRA/TSRA CHANCES INTO THE SOUTH HALF OF THE FCST AREA SUN
MORNING. BY SUN AFTERNOON ALL MODELS SPREAD 1 TO 1.5 INCHES OF PW
INTO THE AREA...WITH MORE SATURATION IN THE 925-700MB LAYER AND
INCREASING LIFT/DIVERGENCE ALOFT AHEAD OF THE MID LEVEL TROUGH.
RATHER DEEP LAYERED WEAK TO MDT LIFT SPREADS ACROSS THE AREA SUN
NIGHT MON AS THE MID LEVEL TROUGH EJECTS INTO THE PLAINS AND THE SFC-
850MB LOW LIFTS TOWARD/INTO THE UPPER MIDWEST. THIS WITH THE 1 TO
1.5 INCH PW VALUES. RAISED PRECIP CHANCES MON TO 70-80 PERCENT SUN
NIGHT AND AROUND 70 PERCENT MON. CARRIED 50-70 PERCENT RAIN CHANCES
YET MON NIGHT WITH THE SLOWING TREND AND SIGNAL FOR THE SFC THRU MID
LEVEL TROUGH TO STILL BE OVER OR WEST OF THE AREA...AT LEAST THRU
THE EVENING. MODEL SOUNDINGS AS MUCH AS 250-1K J/KG MUCAPE OVER THE
SUN/MON AFTERNOONS...BUT AGAIN LIKE SAT GENERALLY A SKINNY CAPE
PROFILE. GIVEN THE HIGH PW VALUES AND BROAD/DEEP FORCING/LIFT...
CARRIED TSRA CHANCES FROM SUN AFTERNOON THRU MON NIGHT. BLEND OF THE
NUMERICAL GUIDANCE FOR HIGHS/LOWS SUN THRU MON NIGHT LOOKS GOOD.
THE DURATION OF THE FORCING/LIFT AND HIGH PW VALUES RAISE THE
CONCERN FOR MORE WIDESPREAD MDT TO HEAVY RAINS OF 1 TO 2 INCHES FROM
SUN NIGHT INTO MON NIGHT. THIS BEARS WATCHING AS FAR AS HYDROLOGY
CONCERNS AND MANY RIVERS IN THE AREA ALREADY RUNNING HIGH. STILL
PLENTY OF MODEL DETAIL DIFFERENCES AS FAR AS THE HEAVY RAIN
POTENTIAL. WILL HOLD OFF ON AN ESF FOR NOW BUT PASS ALONG THOUGHTS
THE THE MIDNIGHT CREW.
FOR TUESDAY THROUGH FRIDAY.../DAYS 4 TO 7/...
MAIN CONCERNS THIS PERIOD...PERIODIC SHRA CHANCES AND BELOW/MUCH
BELOW NORMAL TEMPERATURES.
09.00Z AND 09.12Z MEDIUM RANGE MODELS CONTINUE TO SLOWLY COME
INTO BETTER AGREEMENT AS A DEEP MID LEVEL TROUGH/LOW DRIFTS SLOW
EAST ACROSS CENTRAL NOAM IN THE TUE-FRI PERIOD. GFS REMAINS A BIT
FASTER THAN THE OTHERS WHILE CAN-GEM IS THE SLOWER OF THE LOT.
ECMWF/ENSEMBLE MEANS OFFER A COMPROMISE ON THE PROGRESSIVENESS OF
THE TROUGH TUE-THU. OVERALL CONSENSUS CONTINUES TO TREND TOWARD A
SLOWER/STRONGER TROUGH/MID LEVEL LOW THAN THE EARLIER 08.00Z/
09.00Z RUNS. DAY 4-7 FCST CONFIDENCE AVERAGE THIS CYCLE.
GOOD CONSENSUS TUE FOR THE SFC-850MB LOW/TROUGH FROM SUN/MON TO BE
LIFTING NORTH/EAST OF THE FCST AREA...WITH THE UPPER MIDWEST
DOMINATED BY LOW LEVEL COLD ADVECTION/MUCH COLDER 925-850MB AIR.
GFS/ECMWF HAVE 850MB TEMPS IN THE +3C TO 0C RANGE BY 00Z WED. THIS
AHEAD OF THE 500MB TROUGH AXIS...AS THE TROUGH DEEPENS INTO THE
NORTH-CENTRAL CONUS. FAVORING THE CONSENSUS...THE TROUGH AXIS SHIFTS
EAST AND IS OVER MN/IA/WI WED/THU...WITH 850MB TEMPS OVER THE FCST
AREA BOTTOMING OUT IN THE -2C TO -5C RANGE AT 12Z THU. THE MID LEVEL
TROUGH AXIS SHIFTS EAST OF THE REGION FRI...LEAVING THE UPPER
MIDWEST UNDER ACTIVE/UNSETTLED NORTHWEST FLOW ALOFT. NUMEROUS
DIFFICULT TO TIME SHORTWAVES PROGGED TO ROTATE AROUND/THRU THE DEEP
MID LEVEL TROUGH OR NORTHWEST FLOW OVER THE REGION IN THE TUE-FRI
PERIOD. THIS WITH THE MUCH COLDER THAN NORMAL 850-700MB AIRMASS...
STEEP SFC-700MB LAPSE RATES AND MODEST 850-700MB MOISTURE OVER THE
AREA. THUS EACH OF THESE SHORTWAVES WOULD BE CAPABLE OF PRODUCING
SCT -SHRA ACROSS THE AREA. UNTIL A BETTER SHORTWAVE TIMING CONSENSUS
IS REACHED...SMALL -SHRA CHANCE MUCH OF THE TUE-FRI PERIOD
REASONABLE FOR NOW. 850MB TEMPS MUCH OF THE PERIOD LOOKING TO BE IN
THE 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL RANGE...WITH TUE-FRI
HIGHS/LOWS AROUND 10F BELOW NORMAL. IF LIGHT WINDS/MOSTLY CLEAR
SKIES WOULD PREVAIL FOR THE OVERNIGHT HOURS...SOME FROST WOULD BE
POSSIBLE...ESPECIALLY WED/THU/FRI MORNINGS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1213 PM CDT FRI MAY 9 2014
LOOKING AT THE 09.15Z RAP AND 09.12Z NAM LOW LEVEL RH INDICATES THE
LOW CLOUDS OVER THE AREA SHOULD REMAIN IN PLACE THROUGH THE
AFTERNOON. EXPECT TO SEE THE CEILINGS SLOWLY IMPROVE TO ALMOST VFR
BY LATE AFTERNOON AND THEN THE MOISTURE SHOULD QUICKLY DISSIPATE
EARLY THIS EVENING ALLOWING THE CLOUDS TO SCATTER OUT. THE GUSTY
WINDS WILL ALSO SETTLE DOWN EARLY THIS EVENING AS THE LOW LEVEL
INVERSION DEVELOPS. HIGH PRESSURE WILL BRIEFLY BE OVER THE AREA
TONIGHT FOR CLEAR SKIES AND LIGHT WINDS WITH THE DIRECTION COMING
AROUND TO THE SOUTH AS THE RIDGE AXIS GOES BY. ANOTHER SHORT WAVE
TROUGH WILL BE APPROACHING FROM THE SOUTHWEST SATURDAY. THE NAM
SUGGESTS MID LEVEL MOISTURE AND A HIGH VFR CEILING COULD DEVELOP
ALREADY BY 18Z SATURDAY WHILE THE 09.12Z GFS IS A LITTLE SLOWER TO
BRING THIS MOISTURE IN. FOR NOW...WILL JUST SHOW A SCATTERED MID
LEVEL DECK BUT THE NEXT FORECAST WILL HAVE TO SHOW A CEILING AND MAY
HAVE TO INTRODUCE SOME VICINITY SHOWERS FOR SATURDAY AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 302 PM CDT FRI MAY 9 2014
MINOR FLOODING CONTINUES ALONG PORTIONS OF THE MS RIVER FROM WABASHA
MN TO GUTTENBERG IA. SAT THRU MON NIGHT WILL BRING AT LEAST 2 MORE
ROUNDS OF RAIN. RAIN AMOUNTS LATER SAT AND SAT NIGHT LOOK TO MOSTLY
BE 1/4 INCH OR LESS. AMOUNTS OF AN INCH OR 2 APPEAR POSSIBLE DURING
THE SUN NIGHT/MON PERIOD. THESE RAINS COULD HAVE ADDITIONAL IMPACTS
ON BOTH TRIBUTARIES AND THE MS RIVER...SLOWING THE RATES OF FALL OR
PRODUCE ADDITIONAL RISES.
CHECK THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....04
HYDROLOGY....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1213 PM CDT FRI MAY 9 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 250 AM CDT FRI MAY 9 2014
BULK OF SHOWERS/STORMS HAVE SHIFTED NORTH/EAST EARLY THIS
MORNING...WITH THE LOW LEVEL JET/MOISTURE TRANSPORT FEEDING THE PCPN
NOSING TOWARD THE EASTERN GREAT LAKES.
LOW PRESSURE SYSTEM/COLD FRONT THAT HELPED TRIGGER THE RAINFALL WILL
CONTINUE TO TRACK NORTHEAST THIS MORNING...WITH THE BOUNDARY RUNNING
NORTH-SOUTH ACROSS EASTERN WI BY THIS AFTERNOON. MOISTURE WRAPPED
AROUND THE LOW...COUPLED WITH COLDER AIR A LOFT/FAVORABLE LAPSE
RATES...COULD RESULT IN SHOWERS ACROSS NORTHERN WI THIS AFTERNOON.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 250 AM CDT FRI MAY 9 2014
UNSETTLED WEATHER PATTERN WILL RESULT IN PERIODS OF SHOWERS AND
THUNDERSTORMS FROM SATURDAY NIGHT INTO MONDAY.
UPPER LEVEL SHORTWAVE TROUGH SLATED TO LIFT NORTHEAST OUT OF THE
CENTRAL PLAINS AND ACROSS THE REGION SAT NIGHT. WEAK 850-700 MB WARM
ADVECTION WITH THE SHORTWAVE...WITH THE NOSE OF THE 850 MB MOISTURE
TRANSPORT POINT LEADING IT ACROSS THE AREA. INSTABILITY WEAK...BUT
ENOUGH TO AID IN SHOWER/STORM DEVELOPMENT. TRACK/PLACEMENT OF THE
WEATHER FEATURES FAVORS MN INTO NORTHERN WI FOR THE HIGH RAIN
CHANCES.
BROAD...LONGWAVE UPPER LEVEL TROUGH STARTS TO MOVE OUT OF THE
ROCKIES SUNDAY...WITH BIT OF ENERGY SPINNING OUT OF THE TROUGH
TOWARD THE GREAT LAKES. NAM/GFS RUN A SFC BOUNDARY FROM A LOW OVER
THE SOUTHERN PLAINS...NORTHWARD INTO THE UPPER MISSISSIPPI RIVER
VALLEY. STRONG SURGE OF LOW LEVEL MOISTURE RUNS ALONG/AHEAD OF
THIS...WITH A 40 KT LOW LEVEL JET NOSING IT INTO SOUTHERN WI BY 00Z
MON. THE BULK OF THE INSTABILITY IS EXPECTED TO STAY SOUTH OF THE
LOCAL FORECAST AREA...BUT 0-6 KM SHEAR OF ABOUT 40 KTS FOR SUNDAY
NIGHT. THERE WILL BE A SEVERE THREAT TO THE SOUTH...BUT THIS COULD
CREEP INTO NORTHEAST IA/SOUTHWEST WI. A SMALL ADJUSTMENT IN
PLACEMENT OF THE FRONT/TIMING COULD EXPAND THAT THREAT FURTHER - ITS
A PERIOD OF WATCH.
ROUNDS OF SHOWERS/STORMS WILL CONTINUE INTO MONDAY AS THE SFC LOW
TRACKS INTO THE REGION AND ANOTHER SHORTWAVE SLIDES OUT OF THE MEAN
UPPER LEVEL TROUGH. MID LEVEL DRY PUNCH BEHIND THE SFC LOW MOVES IN
MONDAY NIGHT...AND SHOULD SEE AN END TO THE RAIN CHANCES UNTIL WED.
FOR WEDNESDAY...THE AXIS OF THE UPPER LEVEL TROUGH PUSHES OVER THE
UPPER MISSISSIPPI RIVER VALLEY...WHILE MODELS HINT THAT A SFC TROUGH
WILL HANG WELL WEST/SOUTH OF THE DEPARTING SFC LOW. ABOUT 500 J/KG
OF MUCAPE VIA THE GFS TO PLAY WITH...AND THE EC/GFS BOTH GENERATE
SOME PCPN. ANOTHER PIECE OF ENERGY PROGGED TO STREAK DOWN THE
BACKSIDE OF THE TROUGH ON THU...WITH A FEW MORE SHOWERS POSSIBLE.
LITTLE/IF ANY INSTABILITY INDICATED AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1213 PM CDT FRI MAY 9 2014
LOOKING AT THE 09.15Z RAP AND 09.12Z NAM LOW LEVEL RH INDICATES
THE LOW CLOUDS OVER THE AREA SHOULD REMAIN IN PLACE THROUGH THE
AFTERNOON. EXPECT TO SEE THE CEILINGS SLOWLY IMPROVE TO ALMOST VFR
BY LATE AFTERNOON AND THEN THE MOISTURE SHOULD QUICKLY DISSIPATE
EARLY THIS EVENING ALLOWING THE CLOUDS TO SCATTER OUT. THE GUSTY
WINDS WILL ALSO SETTLE DOWN EARLY THIS EVENING AS THE LOW LEVEL
INVERSION DEVELOPS. HIGH PRESSURE WILL BRIEFLY BE OVER THE AREA
TONIGHT FOR CLEAR SKIES AND LIGHT WINDS WITH THE DIRECTION COMING
AROUND TO THE SOUTH AS THE RIDGE AXIS GOES BY. ANOTHER SHORT WAVE
TROUGH WILL BE APPROACHING FROM THE SOUTHWEST SATURDAY. THE NAM
SUGGESTS MID LEVEL MOISTURE AND A HIGH VFR CEILING COULD DEVELOP
ALREADY BY 18Z SATURDAY WHILE THE 09.12Z GFS IS A LITTLE SLOWER TO
BRING THIS MOISTURE IN. FOR NOW...WILL JUST SHOW A SCATTERED MID
LEVEL DECK BUT THE NEXT FORECAST WILL HAVE TO SHOW A CEILING AND
MAY HAVE TO INTRODUCE SOME VICINITY SHOWERS FOR SATURDAY
AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 250 AM CDT FRI MAY 9 2014
WATER CONTINUES HIGH ALONG THE MISSISSIPPI RIVER...WITH A FEW
LOCATIONS STILL IN OR NEAR FLOOD. IN ADDITION TO THE RAINFALL OF
YESTERDAY...SATURDAY THROUGH MONDAY WILL BRING A FEW MORE ROUNDS OF
RAIN. AMOUNTS COULD EXCEED AN INCH. THIS COULD HAVE ADDITIONAL
IMPACTS...SLOWING RATES OF FALL...OR PRODUCE ADDITIONAL RISES.
CHECK THE LATEST HYDROLOGIC STATEMENTS FOR THE DETAILS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
HYDROLOGY....RIECK