Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 04/14/15
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
816 PM MDT MON APR 13 2015
.UPDATE...
ISSUED AT 814 PM MDT MON APR 13 2015
GUSTY SOUTHERLY WIND ON THE PLAINS THIS EVENING RESULT OF TIGHT
CROSS PLAINS PRESSURE GRADIENT. MODELS SHOW 15-25KT WIND GUSTS
EXPANDING UPWARD ACROSS THE PLAINS THROUGH THE EVENING...BUT
STRONGEST WINDS ARE LIKELY TO REMAIN OVER AND JUST NORTH OF THE
PALMER DIVIDE. FOR INSTANCE...CENTENNIAL AIRPORT/KAPA/JUST SOUTH
OF DENVER WAS GUSTING FROM THE SOUTH AT 28KTS ATTM. MOST MODELS
SHOW THESE WINDS EASING AFTER MIDNIGHT...BUT THE RAP LITTLE LET UP
IN THESE WINDS ALL NIGHT. OTHERWISE CURRENT FORECAST LOOKS ON
TRACK FOR THE REMAINDER OF THE NIGHT. ONLY MINOR ADJUSTMENTS TO
THE TEMP AND WIND GRIDS ARE NECESSARY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 106 PM MDT MON APR 13 2015
TONIGHT...THE UPPER LOW NEAR THE TEXAS PANHANDLE WL CONTINUE TO
SHIFT TO THE EAST...WITH A FLAT UPPER RIDGE AND IT RELATIVELY WEAK
WESTERLY FLOW ALOFT OVER NORTHERN COLORADO. ON TUESDAY...THE FLOW
ALOFT START TO SHIFT TO THE SOUTHWEST AND INCREASE AS A SYSTEM
MOVES INTO THE PACIFIC NORTHWEST. IN THE MOUNTAINS...THERE MAY BE
ENOUGH MID LEVEL MOISTURE BY THE AFTERNOON FOR A FEW HIGH BASED
THUNDERSTORMS TO DEVELOP. THE NAM12 FORECAST SOUNDINGS REFLECT
ENOUGH MOISTURE AND INSTBY AT THAT TIME. ACROSS THE NORTHEAST
PLAINS...IT WILL BE ANOTHER WARM AND WINDY DAY...ESPECIALLY EAST
OF INTERSTATE 25. THE MDLS INCREASE SOUTHEAST WINDS BY THE AFTN
WITH SOME GUSTS IN THE 35 TO 40 MPH RANGE. WL HOIST A RED FLAG
WARNING WARNING FOR THE PALMER DIVIDE AND NORTHEAST PLAINS FM 11
AM MDT TUESDAY MORNING TO 8 PM MDT TUESDAY EVENING. SEE THE
DISCUSSION BELOW.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 140 PM MDT MON APR 13 2015
TUESDAY NIGHT AND WEDNESDAY APPEAR AT THIS POINT TO BE FAIRLY
QUIET AHEAD OF THE MAIN WEATHER MAKER FOR THE WEEK. THE MODELS
ARE BEGINNING TO SHOW MORE CONSISTENCY AMONGST THEMSELVES AT 12Z
TODAY WITH NEARLY ALL OF THEM PREDICTING A MID-TROPOSPHERIC CLOSED
CYCLONE CENTERED NEAR THE FOUR CORNERS AREA BY 12Z THURSDAY.
AFTER THAT THERE IS A HODGEPODGE OF LOCATIONS AND MOVEMENTS OF
THE SYSTEM WITH SOME MODELS KEEPING THINGS FAR ENOUGH SOUTH OF US
TO LIMIT PRECIPITATION IN OUR CWA. THE GFS IS THE GENERAL OUTLIER
HERE KEEPING MORE OF AN ELONGATED TROUGH MOVING THROUGH FAIRLY
QUICKLY. BASED ON THE GFS ENSEMBLE DATA IT APPEARS THAT THE
OPERATIONAL GFS RUN MAY HAVE LESS OF A CHANCE OF VERIFYING AND
PROBABLY SHOULD NOT BE CONSIDERED IN THIS CYCLE. REMAINING MODELS
HAVE VARYING DEGREES OF QG ASCENT OVER OUR NECK OF THE WOODS
THURSDAY AND FRIDAY BUT THE LARGEST MAGNITUDES OF THAT PARAMETER
WOULD FAVOR HEAVIER AMOUNTS OF PRECIPITATION OVER SOUTHEAST
COLORADO. UPSLOPE FLOW IS ALSO DECENT WITH SOME CONNECTION TO THE
GULF OF MEXICO IN SOME OF THE MODELS. CONSIDERING ALL OF THIS IT
STILL SEEMS PRUDENT NOT TO JUMP INTO THE DEEP END YET AND A
CONSENSUS FORECAST STILL LOOKS PRETTY GOOD. CONSEQUENTLY THE
LATEST UPDATES TO THE GRIDS HAVE NOT CHANGED THINGS TOO
DRASTICALLY.
WEATHER IN THE LATTER PERIODS HINGE ON MOVEMENT OF THE CYCLONE
AND WITH SO MUCH STILL UP IN THE AIR HAVE JUST TRENDED A GENERAL
DRYING TREND WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES.
THERE IS A HINT OF A WEAK TROUGH SKIMMING BY ON SUNDAY SO HAVE A
BIT HIGHER POPS THEN...MAINLY IN THE MOUNTAINS.
&&
.AVIATION...(FOR THE TAFS THROUGH 06Z TUESDAY EVENING)
ISSUED AT 814 PM MDT MON APR 13 2015
GUSTY SOUTHERLY WINDS EXPECTED AT KDEN AND KAPA AT LEAST THROUGH
06Z TONIGHT. GUSTY WINDS MAY LINGER WELL BEYOND THAT AT KAPA.
SUSTAINED WINDS SPEEDS OF 10-15KTS WILL BE COMMON WITH POSSIBLE GUSTS
IN THE 20-25KT RANGE. CLOSER TO THE FOOTHILLS AT KBJC...WINDS NO
WHERE AS GUSTY/STRONG. HERE LIGHT SOUTHERLY BREEZES SHOULD PERSIST
THROUGH THE NIGHT. LASTLY PLAN FOR VFR CONDITIONS UNDER A GENERALLY
CLEAR SKY.
&&
.FIRE WEATHER...
ISSUED AT 106 PM MDT MON APR 13 2015
ANOTHER WARM AND WINDY AFTN EXPECTED ON TUESDAY. SFC WINDS EAST OF
INTERSTATE 25 WILL INCREASE AS A SE TO NW SFC PRESSURE GRADIENT
DEVELOPS IN THE AFTN. GUSTS IN THE 35 TO 40 MPH RANGE EXPECTED. IN
ADDITION...TEMPERATURES IN THE LOW TO MID 70S WL PRODUCE MIN
RELATIVE HUMIDITIES IN THE LOW/MID TEENS. IT IS MARGINAL BUT WL
HEDGE ON THE SIDE OF CAUTION AT THIS TIME A UPGRADE TO A RED FLAG
WARNING. SEE THE AFFECT FIRE WEATHER ZONES BELOW.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 11 AM TO 8 PM MDT TUESDAY FOR COZ241-242-
244>251.
&&
$$
UPDATE...BAKER
SHORT TERM...COOPER
LONG TERM...ET
AVIATION...BAKER
FIRE WEATHER...COOPER
AREA FORECAST DISCUSSION
NWS ALBANY NY
948 PM EDT MON APR 13 2015
.SYNOPSIS...
A FAST MOVING COLD FRONT WILL BRING SHOWERS TO THE AREA TONIGHT
INTO EARLY TUESDAY MORNING. DRY WEATHER WILL RETURN TUESDAY
AFTERNOON AND PERSIST THROUGH THURSDAY. OUR NEXT CHANCES FOR
SHOWERS WILL COME LATE IN THE WEEK INTO THE FIRST PART OF THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 947 PM EDT...REGIONAL MOSAIC RADAR IMAGERY CONTINUES TO
SHOW A BAND OF SHOWERS MOVING TOWARDS THE REGION. THESE SHOWERS
ARE ALONG/AHEAD OF A FAST MOVING SFC COLD FRONT AND UPPER LEVEL
SHORTWAVE MOVING ACROSS THE GREAT LAKES REGION. WITHIN THE LINE OF
SHOWERS...THERE LOOKS TO BE A FINE LINE OF ENHANCED ECHOES.
ALTHOUGH THERE HASN/T BEEN ANY LTG STRIKES NOTED ON THE NLDN
NETWORK OVER THE PAST FEW HOURS...THERE MAY BE SOME ELEVATED
CONVECTIVE ELEMENTS WITHIN THE SHOWERS. THE LATEST 3KM HRRR SHOWS
THESE ELEMENTS WEAKENING AS THEY REACH INTO OUR REGION...AS
NOCTURNAL EFFECTS CONTINUE TO OCCUR AND THE HEAVIER SHOWERS STARTS
TO OUTRUN THEIR BEST SUPPORT ALOFT. SHOWERS HAVE BEEN TRACKED SW
TO NE...SO IT WILL TAKE A LITTLE WHILE STILL FOR ACTIVITY TO REACH
OUR ENTIRE AREA. WHILE SHOWERS SHOULD REACH THE ADKS BETWEEN 10 PM
AND MIDNIGHT...IT MAY TAKE UNTIL 1 TO 3 AM TO MOVE TOWARDS THE
CAPITAL REGION...AND EVEN INTO THE LATE NIGHT HOURS TO REACH THE
MID HUDSON VALLEY...BERKSHIRES AND NW CT. TOTAL QPF WILL BE
GENERALLY A TENTH TO A QUARTER OF AN INCH...WITH HEAVIEST AMOUNTS
IN NW AREAS.
EVEN WITHOUT CONVECTIVE ELEMENTS...MAY BE SOME WIND GUSTS TONIGHT IN
THE 25 TO 40 MPH RANGE THANKS TO A STRENGTHENING PRESSURE
GRADIENT. SOUTHERLY WINDS AHEAD OF THE FRONT HAVE BEEN 10-15 KTS
WITH GUSTS ALREADY UP TO 30 KTS. WINDS LOOKS TO SWITCH TO THE WEST
LATE TONIGHT AS THE SFC BOUNDARY CROSSES THE REGION.
TEMPS HAVE BEEN HELD UP AHEAD OF THE FRONT IN THE 60S THANKS TO
THE WARM AND MOIST SOUTHERLY FLOW. THEY WILL START TO DROP LATE
TONIGHT AS THE BOUNDARY CROSSES THROUGH...WITH LOWS MAINLY IN THE
40S.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
FAIR AND DRY WEATHER IS EXPECTED TUESDAY AFTERNOON THROUGH
WEDNESDAY NIGHT AS HIGH PRESSURE DOMINATES.
THE COLD FRONT WILL MOVE OFF TO OUR SOUTH AND EAST TUESDAY AND
HIGHER PRESSURE WILL BUILD IN. THE AIRMASS WILL BE COOLER HOWEVER
THE FLOW ALOFT WILL BE ZONAL AS THE REGION IS LOCATED ON THE
SOUTHERN PERIPHERY OF THE UPPER TROUGH. TEMPERATURES ARE EXPECTED
TO REMAIN ABOVE NORMAL WITH AFTERNOON HIGHS IN THE MID 50S TO
UPPER 60S.
DESPITE A SHORT WAVE MOVING ACROSS NEW ENGLAND THROUGH THE UPPER
LEVEL TROUGH WEDNESDAY DRY WEATHER IS EXPECTED WITH RIDGING
BUILDING IN FROM THE NORTHWEST AT THE SURFACE. WITH THE PASSAGE OF
THE SHORT WAVE HEIGHTS WILL RISE ALOFT WITH RIDGING BUILDING IN.
THE SURFACE HIGH WILL MOVE SOUTHWARD AND CREST OVER REGION
OVERNIGHT WEDNESDAY INTO THURSDAY MORNING. SEASONABLY COOL
TEMPERATURES ARE EXPECTED AT NIGHT WITH ABOVE NORMAL AFTERNOON
HIGHS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
UNSETTLED WEATHER IS EXPECTED AT TIMES DURING THE EXTENDED
PERIOD...AS SEVERAL STORMS SYSTEM MOVING WITHIN THE ZONAL FLOW
IMPACT THE REGION.
THURSDAY NIGHT INTO FRIDAY...AN UPPER LEVEL DISTURBANCE WILL PASS
ACROSS THE REGION. THIS SYSTEM WILL BE FAIRLY WEAK AND THERE WON/T
BE A TON OF MOISTURE TO WORK WITH...BUT THERE IS A CHANCE FOR SOME
LIGHT RAIN SHOWERS ACROSS THE AREA...ALONG WITH PLENTY OF CLOUDS.
TEMPS LOOK SEASONABLE...WITH MINS THURSDAY NIGHT IN THE MID 30S TO
LOW 40S...AND HIGHS ON FRIDAY IN THE MID 50S TO LOW 60S.
THERE LOOKS TO BE A LULL IN THE ACTION FOR FRIDAY NIGHT INTO AT
LEAST SATURDAY MORNING...WITH SOME BREAKS IN THE CLOUDS POSSIBLE.
STILL CANNOT TOTALLY RULE OUT A SHOWER SO WILL MAINTAIN SLIGHT TO
LOW CHC POPS FOR FRIDAY NIGHT. TEMPS ON FRI NIGHT LOOK BE IN THE
UPPER 30S TO UPPER 40S.
A MUCH STRONGER FRONTAL SYSTEM WILL BE APPROACHING FOR SAT AFTN INTO
SAT NIGHT. THERE WILL BE BETTER CHANCE FOR RAIN SHOWERS WITH THIS
SYSTEM...AS THERE WILL BE A STRONGER THERMAL GRADIENT WITH THE SFC
COLD FRONT AS COMPARED TO THE PREVIOUS STORM SYSTEM. THERE ARE STILL
TIMING DIFFERENCES WITHIN THE MODELS...SO WON/T GO ANY HIGHER THAN
CHC FOR POPS SAT AFTN THROUGH SAT NIGHT UNTIL THE TIMING BECOMES
MORE CERTAIN. TEMPS ON SAT LOOK TO BE IN THE UPPER 50S TO UPPER 60S
AHEAD OF THE APPROACHING FRONTAL BOUNDARY.
SHOWERS SHOULD BE ENDING SOMETIME SAT EVENING OR NIGHT...AND THEN
COOLER AND DRIER WEATHER WILL BE IN PLACE BEHIND THE BOUNDARY FOR
SUN THROUGH SUN NIGHT. TEMPS WILL GENERALLY BE IN THE 50S TO LOW 60S
FOR HIGHS ON SUNDAY...WITH LOWS IN THE 30S FOR SUN NIGHT...AS AN
AREA OF HIGH PRESSURE LOOKS TO PASS ACROSS THE REGION.
THE NEXT STORM SYSTEM LOOKS TO IMPACT THE REGION AT SOME POINT EARLY
NEXT WEEK WITH ANOTHER SHOT OF LIGHT RAIN SHOWERS. WILL GO WITH JUST
SLIGHT TO LOW CHC POPS FOR MON/MON NIGHT...WITH TEMPS AROUND
SEASONABLE LEVELS.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
FLYING CONDITIONS WILL GENERALLY BE VFR THROUGH THE TAF PERIOD.
SOUTHERLY WINDS THIS EVENING WILL BE AROUND 10 KTS WITH SOME
HIGHER GUSTS AT TIMES. CURRENTLY...THERE IS SCT-BKN MID/HIGH
LEVEL CLOUDS...BUT LOWERS CLOUDS OF 3500-5000 FT WILL MOVE IN
ALONG WITH A FRONTAL BOUNDARY TONIGHT. THERE WILL BE SOME SHOWERS
WITH THE BOUNDARY AND WINDS WILL START TO SWITCH TO A SW DIRECTION.
A BRIEF PERIOD OF MVFR CIGS/VSBYS CANNOT BE RULED OUT WITHIN THE
SHOWERS...BUT GENERALLY VSBY SHOULD BE IN THE VFR RANGE. SHOWERS
ONLY LOOK TO LAST A FEW HOURS AT ANY ONE PARTICULAR TAF SITE. THE
VERY DRY LOW LEVELS DUE TO GOOD MIXING EARLIER TODAY WILL HELP
PREVENT CIGS FROM GETTING VERY LOW...AND SHOULD GENERALLY KEEP VFR
CONDITIONS IN PLACE.
WINDS WILL SWITCH TO A WESTERLY DIRECTION LATE TONIGHT AS THE
FRONT GOES THROUGH...AND THE THREAT FOR RAIN SHOWERS WILL END
10Z-13Z. SKIES SHOULD CLEAR OUT QUICK...WITH JUST SOME SCT-BKN
HIGH CIRRUS CLOUDS IN IT/S WAKE FOR THE DAY ON TUESDAY. WEST WINDS
WILL REACH UP TO ABOUT 10 KTS WITHIN DAYTIME MIXING ON TUESDAY.
OUTLOOK... TUE NIGHT-THU: NO OPERATIONAL IMPACT. NO SIG WX.
THU NIGHT-FRI: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRI NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SAT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
TONIGHT...A COLD FRONT WILL BRING NUMEROUS SHOWERS TO THE
REGION...WITH A TENTH TO A QUARTER OF AN INCH OF RAINFALL EXPECTED.
THE FRONT WILL MOVE OFF TO OUR SOUTH AND EAST TUESDAY ALLOWING
HIGH PRESSURE TO BUILD IN FROM THE NORTHWEST. WESTERLY WIND WILL
INCREASE TO 10 TO 20 MPH AND RELATIVE HUMIDITY VALUES ARE EXPECTED
TO FALL WITH AFTERNOON MINIMUMS IN THE LOWER 20S TO LOWER 30S.
RELATIVE HUMIDITY VALUES ARE EXPECTED TO RECOVERY TO 70 TO 90
PERCENT TUESDAY NIGHT.
WEDNESDAY AND THURSDAY WILL BE DRY WITH SEASONABLY WARM TEMPERATURES.
MINIMUMS RELATIVE HUMIDITY ARE FORECAST TO BE IN THE LOWER 20S TO
LOWER 30S WEDNESDAY AFTERNOON WITH NORTHWESTERLY WINDS. ON
THURSDAY...MINIMUMS RELATIVE HUMIDITY IN MID 20S TO MID 30S ARE
EXPECTED WITH SOUTHERLY WINDS.
OUR NEXT CHANCES FOR SHOWERS WILL COME THURSDAY NIGHT WITH
UNSETTLED WEATHER EXPECTED THROUGH THE FIRST HALF OF THE WEEKEND.
&&
.HYDROLOGY...
THE WARMER WEATHER IS PRODUCE RUNOFF FROM SNOW MELT. A FAST MOVING
COLD FRONT WILL BRING A PERIOD OF SHOWERS TO THE REGION TONIGHT
INTO TUESDAY MORNING. FORECAST QPF AMOUNTS OF A TENTH TO A QUARTER
OF AN INCH ARE EXPECTED. THERE WILL BE RISES ON SOME RIVERS AND
STREAMS. BASED ON CURRENT FORECASTS ONLY DELTA DAM ON THE MOHAWK
RIVER IS EXPECTED TO EXCEED FLOOD STAGE AND THIS IS EXPECTED TO
OCCUR TUESDAY AFTERNOON.
NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
SHOWS SNOWPACK LEFT ACROSS MAINLY THE SOUTHERN ADIRONDACKS...HIGHER
TERRAIN OF THE EASTERN CATSKILLS AND ACROSS SOUTHERN VERMONT AND
THE NORTHERN BERKSHIRES. THE HIGHEST SNOW WATER EQUIVALENT IS
ACROSS THE HIGHER TERRAIN OF THE SOUTHERN GREEN MOUNTAINS WHERE
THERE IS STILL 6 UP TO POSSIBLY 12 INCHES.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA
NEAR TERM...FRUGIS
SHORT TERM...IAA
LONG TERM...FRUGIS
AVIATION...FRUGIS
FIRE WEATHER...IAA/HWJIV
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
731 PM EDT MON APR 13 2015
.SYNOPSIS...
A FAST MOVING COLD FRONT WILL BRING SHOWERS TO THE AREA TONIGHT
INTO EARLY TUESDAY MORNING. DRY WEATHER WILL RETURN TUESDAY
AFTERNOON AND PERSIST THROUGH THURSDAY. OUR NEXT CHANCES FOR
SHOWERS WILL COME LATE IN THE WEEK INTO THE FIRST PART OF THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 731 PM EDT...FAST MOVING COLD FRONT IS CURRENTLY OVER
WESTERN NY AND HEADING EASTWARD. KBUF RADAR SHOWS A BAND OF
SHOWERS ASSOCIATED WITH THE BOUNDARY...MAKING ITS WAY EASTWARD.
CHANCES FOR SHOWERS WILL INCREASE THIS EVENING WITH LIKELY POPS
OVERSPREADING THE AREA MAINLY AFTER MIDNIGHT. THE 22Z RUN OF THE
3KM HRRR SHOWS SHOWERS REACHING WESTERN ADK/MOHAWK VALLEY BY
03Z-05Z...CAPITAL REGION/HUDSON VALLEY/SRN VT BY 05Z-07Z...AND
BERKSHIRES/NW CT BY 07Z-10Z. SHOWERS ONLY LOOK TO LAST A FEW HOURS
AT ANY ONE PARTICULAR LOCATION...WITH RAINFALL AMOUNTS OF A TENTH
TO A QUARTER OF AN INCH ARE EXPECTED. DO NOT HAVE ANY MENTION OF
THUNDERSTORM IN THE FORECAST...THAT THREAT SHOULD REMAIN TO OUR
WEST WHICH IS IN AGREE WITH THE STORM PREDICTION CENTER`S DAY 1
OUTLOOK.
AFTER SUCH MILD TEMPS TODAY AND A SOUTHERLY BREEZE IN PLACE AHEAD
OF THE FRONT...TEMPS THIS EVENING REMAIN WARM IN THE 60S TO LOW
70S. TEMPS WILL COOL AS RAIN MOVES IN...AND WINDS START TO SWITCH
TO THE WEST. MINS LATE TONIGHT WILL GENERALLY BE IN THE 40S.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
FAIR AND DRY WEATHER IS EXPECTED TUESDAY AFTERNOON THROUGH
WEDNESDAY NIGHT AS HIGH PRESSURE DOMINATES.
THE COLD FRONT WILL MOVE OFF TO OUR SOUTH AND EAST TUESDAY AND
HIGHER PRESSURE WILL BUILD IN. THE AIRMASS WILL BE COOLER HOWEVER
THE FLOW ALOFT WILL BE ZONAL AS THE REGION IS LOCATED ON THE
SOUTHERN PERIPHERY OF THE UPPER TROUGH. TEMPERATURES ARE EXPECTED
TO REMAIN ABOVE NORMAL WITH AFTERNOON HIGHS IN THE MID 50S TO
UPPER 60S.
DESPITE A SHORT WAVE MOVING ACROSS NEW ENGLAND THROUGH THE UPPER
LEVEL TROUGH WEDNESDAY DRY WEATHER IS EXPECTED WITH RIDGING
BUILDING IN FROM THE NORTHWEST AT THE SURFACE. WITH THE PASSAGE OF
THE SHORT WAVE HEIGHTS WILL RISE ALOFT WITH RIDGING BUILDING IN.
THE SURFACE HIGH WILL MOVE SOUTHWARD AND CREST OVER REGION
OVERNIGHT WEDNESDAY INTO THURSDAY MORNING. SEASONABLY COOL
TEMPERATURES ARE EXPECTED AT NIGHT WITH ABOVE NORMAL AFTERNOON
HIGHS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
UNSETTLED WEATHER IS EXPECTED AT TIMES DURING THE EXTENDED
PERIOD...AS SEVERAL STORMS SYSTEM MOVING WITHIN THE ZONAL FLOW
IMPACT THE REGION.
THURSDAY NIGHT INTO FRIDAY...AN UPPER LEVEL DISTURBANCE WILL PASS
ACROSS THE REGION. THIS SYSTEM WILL BE FAIRLY WEAK AND THERE WON/T
BE A TON OF MOISTURE TO WORK WITH...BUT THERE IS A CHANCE FOR SOME
LIGHT RAIN SHOWERS ACROSS THE AREA...ALONG WITH PLENTY OF CLOUDS.
TEMPS LOOK SEASONABLE...WITH MINS THURSDAY NIGHT IN THE MID 30S TO
LOW 40S...AND HIGHS ON FRIDAY IN THE MID 50S TO LOW 60S.
THERE LOOKS TO BE A LULL IN THE ACTION FOR FRIDAY NIGHT INTO AT
LEAST SATURDAY MORNING...WITH SOME BREAKS IN THE CLOUDS POSSIBLE.
STILL CANNOT TOTALLY RULE OUT A SHOWER SO WILL MAINTAIN SLIGHT TO
LOW CHC POPS FOR FRIDAY NIGHT. TEMPS ON FRI NIGHT LOOK BE IN THE
UPPER 30S TO UPPER 40S.
A MUCH STRONGER FRONTAL SYSTEM WILL BE APPROACHING FOR SAT AFTN INTO
SAT NIGHT. THERE WILL BE BETTER CHANCE FOR RAIN SHOWERS WITH THIS
SYSTEM...AS THERE WILL BE A STRONGER THERMAL GRADIENT WITH THE SFC
COLD FRONT AS COMPARED TO THE PREVIOUS STORM SYSTEM. THERE ARE STILL
TIMING DIFFERENCES WITHIN THE MODELS...SO WON/T GO ANY HIGHER THAN
CHC FOR POPS SAT AFTN THROUGH SAT NIGHT UNTIL THE TIMING BECOMES
MORE CERTAIN. TEMPS ON SAT LOOK TO BE IN THE UPPER 50S TO UPPER 60S
AHEAD OF THE APPROACHING FRONTAL BOUNDARY.
SHOWERS SHOULD BE ENDING SOMETIME SAT EVENING OR NIGHT...AND THEN
COOLER AND DRIER WEATHER WILL BE IN PLACE BEHIND THE BOUNDARY FOR
SUN THROUGH SUN NIGHT. TEMPS WILL GENERALLY BE IN THE 50S TO LOW 60S
FOR HIGHS ON SUNDAY...WITH LOWS IN THE 30S FOR SUN NIGHT...AS AN
AREA OF HIGH PRESSURE LOOKS TO PASS ACROSS THE REGION.
THE NEXT STORM SYSTEM LOOKS TO IMPACT THE REGION AT SOME POINT EARLY
NEXT WEEK WITH ANOTHER SHOT OF LIGHT RAIN SHOWERS. WILL GO WITH JUST
SLIGHT TO LOW CHC POPS FOR MON/MON NIGHT...WITH TEMPS AROUND
SEASONABLE LEVELS.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
FLYING CONDITIONS WILL GENERALLY BE VFR THROUGH THE TAF PERIOD.
SOUTHERLY WINDS THIS EVENING WILL BE AROUND 10 KTS WITH SOME
HIGHER GUSTS AT TIMES. CURRENTLY...THERE IS SCT-BKN MID/HIGH
LEVEL CLOUDS...BUT LOWERS CLOUDS OF 3500-5000 FT WILL MOVE IN
ALONG WITH A FRONTAL BOUNDARY TONIGHT. THERE WILL BE SOME SHOWERS
WITH THE BOUNDARY AND WINDS WILL START TO SWITCH TO A SW DIRECTION.
A BRIEF PERIOD OF MVFR CIGS/VSBYS CANNOT BE RULED OUT WITHIN THE
SHOWERS...BUT GENERALLY VSBY SHOULD BE IN THE VFR RANGE. SHOWERS
ONLY LOOK TO LAST A FEW HOURS AT ANY ONE PARTICULAR TAF SITE. THE
VERY DRY LOW LEVELS DUE TO GOOD MIXING EARLIER TODAY WILL HELP
PREVENT CIGS FROM GETTING VERY LOW...AND SHOULD GENERALLY KEEP VFR
CONDITIONS IN PLACE.
WINDS WILL SWITCH TO A WESTERLY DIRECTION LATE TONIGHT AS THE
FRONT GOES THROUGH...AND THE THREAT FOR RAIN SHOWERS WILL END
10Z-13Z. SKIES SHOULD CLEAR OUT QUICK...WITH JUST SOME SCT-BKN
HIGH CIRRUS CLOUDS IN IT/S WAKE FOR THE DAY ON TUESDAY. WEST WINDS
WILL REACH UP TO ABOUT 10 KTS WITHIN DAYTIME MIXING ON TUESDAY.
OUTLOOK... TUE NIGHT-THU: NO OPERATIONAL IMPACT. NO SIG WX.
THU NIGHT-FRI: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRI NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SAT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
TONIGHT...A COLD FRONT WILL BRING NUMEROUS SHOWERS TO THE
REGION...WITH A TENTH TO A QUARTER OF AN INCH OF RAINFALL EXPECTED.
THE FRONT WILL MOVE OFF TO OUR SOUTH AND EAST TUESDAY ALLOWING
HIGH PRESSURE TO BUILD IN FROM THE NORTHWEST. WESTERLY WIND WILL
INCREASE TO 10 TO 20 MPH AND RELATIVE HUMIDITY VALUES ARE EXPECTED
TO FALL WITH AFTERNOON MINIMUMS IN THE LOWER 20S TO LOWER 30S.
RELATIVE HUMIDITY VALUES ARE EXPECTED TO RECOVERY TO 70 TO 90
PERCENT TUESDAY NIGHT.
WEDNESDAY AND THURSDAY WILL BE DRY WITH SEASONABLY WARM TEMPERATURES.
MINIMUMS RELATIVE HUMIDITY ARE FORECAST TO BE IN THE LOWER 20S TO
LOWER 30S WEDNESDAY AFTERNOON WITH NORTHWESTERLY WINDS. ON
THURSDAY...MINIMUMS RELATIVE HUMIDITY IN MID 20S TO MID 30S ARE
EXPECTED WITH SOUTHERLY WINDS.
OUR NEXT CHANCES FOR SHOWERS WILL COME THURSDAY NIGHT WITH
UNSETTLED WEATHER EXPECTED THROUGH THE FIRST HALF OF THE WEEKEND.
&&
.HYDROLOGY...
THE WARMER WEATHER IS PRODUCE RUNOFF FROM SNOW MELT. A FAST MOVING
COLD FRONT WILL BRING A PERIOD OF SHOWERS TO THE REGION TONIGHT
INTO TUESDAY MORNING. FORECAST QPF AMOUNTS OF A TENTH TO A QUARTER
OF AN INCH ARE EXPECTED. THERE WILL BE RISES ON SOME RIVERS AND
STREAMS. BASED ON CURRENT FORECASTS ONLY DELTA DAM ON THE MOHAWK
RIVER IS EXPECTED TO EXCEED FLOOD STAGE AND THIS IS EXPECTED TO
OCCUR TUESDAY AFTERNOON.
NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
SHOWS SNOWPACK LEFT ACROSS MAINLY THE SOUTHERN ADIRONDACKS...HIGHER
TERRAIN OF THE EASTERN CATSKILLS AND ACROSS SOUTHERN VERMONT AND
THE NORTHERN BERKSHIRES. THE HIGHEST SNOW WATER EQUIVALENT IS
ACROSS THE HIGHER TERRAIN OF THE SOUTHERN GREEN MOUNTAINS WHERE
THERE IS STILL 6 UP TO POSSIBLY 12 INCHES.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/FRUGIS
SHORT TERM...IAA
LONG TERM...FRUGIS
AVIATION...FRUGIS
FIRE WEATHER...IAA/HWJIV
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1215 PM EDT SUN APR 12 2015
.SYNOPSIS...
HIGH PRESSURE OVER OUR AREA WILL GRADUALLY SHIFT OFFSHORE THIS
AFTERNOON INTO TONIGHT. A COLD FRONT WILL THEN CROSS OUR AREA
TUESDAY MORNING. HIGH PRESSURE BUILDS OVER OUR REGION AND WILL
REMAIN IN PLACE THROUGH THURSDAY, THEN ANOTHER COLD FRONT IS
EXPECTED BY NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SPRAWLING AREA OF SURFACE HIGH PRESSURE OVER OUR REGION AT
MIDDAY, WILL GRADUALLY SHIFT OFFSHORE DURING THE AFTERNOON. AS
THIS OCCURS, THE LIGHT FLOW WILL TURN SOUTHWESTERLY ACROSS THE
REGION. THE 12Z STERLING, VA RAOB SHOWS A RATHER DRY AIRMASS IN
PLACE.
WHILE PLENTY OF SUNSHINE IS EXPECTED, THERE IS A SHORT WAVE ALONG
WITH SOME WAA ONGOING IN THE CENTRAL MISSISSIPPI VALLEY. THIS
ALONG WITH AN UPPER-LEVEL JET IS ASSISTING IN SOME HIGH LEVEL
CLOUDS JUST TO OUR SOUTHWEST. SOME OF THIS SHOULD ARRIVE IN OUR
REGION AS WE GO THROUGH THE AFTERNOON.
THE DRY AIRMASS AND AMPLE SUNSHINE HAS HELPED BOOST TEMPERATURES
QUICKLY FROM THE CHILLY START, AND WE ARE EXPECTING HIGHS WELL
INTO THE 60S FOR MUCH OF THE AREA. GIVEN THE LIGHTER FLOW THOUGH
AND AMPLE BOUNDARY LAYER HEATING, A SEA/BAY BREEZE SHOULD DEVELOP
DURING THE COURSE OF THIS AFTERNOON. AS A RESULT, TEMPERATURES
WILL BE COOLER ALONG THE COAST. THE HRRR AND RAP SHOW THE SURFACE
FLOW TURNING SOUTH-SOUTHEAST THIS AFTERNOON ALONG THE COAST IN
RESPONSE.
THE HOURLY GRIDS WERE ADJUSTED BASED ON THE LATEST OBSERVATIONS,
THEN THE LAMP/LAV GUIDANCE WAS USED TO ASSIST. THIS INCLUDED
LOWERING THE DEW POINTS SOME, AND THESE LOWER DEW POINTS SHOULD
BE MAINTAINED FOR MUCH OF THE AREA WITH AMPLE BOUNDARY LAYER
HEATING DESPITE LESS MIXING. NO MAJOR CHANGES WERE MADE TO THE
HIGH TEMPERATURES ATTM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE HIGH WILL CONTINUE TO MOVE EWD AS A CDFNT IN THE
MIDWEST ADVANCES EWD. EXPECT A GENLY CLEAR NIGHT WITH A MORE SWLY
FLOW SO TEMPS WONT BE AS CHILLY AS TONIGHT. CLOUDS SHUD INCREASE A
BIT IN WRN AREAS BY DAYBREAK.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
PRIMARY FOCUS IN THE LONG TERM WILL BE ON A COLD FRONT PASSAGE
MONDAY NIGHT INTO TUESDAY MORNING, AND A MUDDLED PATTERN THURSDAY
NIGHT INTO SATURDAY.
MONDAY...FIRST THOUGH, GOOD NEWS ABOUT MONDAY, IT WILL BE
BEAUTIFUL. WARM AIR ADVECTION EXPECTED AS THE HIGH SHIFTS OFF
SHORE AND THE LOW LEVEL FLOW SHIFTS TO SOUTHWESTERLY. THEREFORE,
MANY LOCATIONS SHOULD SEE HIGHS NEAR OR ABOVE 70. THE ABOVE NORMAL
TEMPERATURES, AND SOMEWHAT LIMITED MOISTURE ADVECTION COULD LEAD
TO MARGINAL FIRE WEATHER CONDITIONS (SEE FIRE WEATHER SECTION
BELOW), BUT OTHERWISE, IT SHOULD BE A NICE SPRING DAY.
MONDAY NIGHT INTO TUESDAY...MODELS REMAIN IN RELATIVELY GOOD
AGREEMENT WITH A COLD FRONT PUSHING THROUGH LATE MONDAY NIGHT INTO
TUESDAY MORNING. THE CENTER OF THE ASSOCIATED SURFACE LOW SHOULD
WILL MOVE ACROSS THE HUDSON BAY AREA, KEEPING MOST OF THE SYNOPTIC
SCALE LIFT WELL NORTH OF US. IN ADDITION, A PERSISTENT AND DEEP WARM
MID LAYER WILL LEAD TO VERY MINIMAL INSTABILITY. THUS, MUCH OF THE
REGION HAS ONLY A BRIEF WINDOW OF OPPORTUNITY WITH ISENTROPIC LIFT
AS THE FRONT MOVES THROUGH FOR ANY SHOWERS, AND THUNDERSTORMS, AT
LEAST IN OUR AREA ARE VERY UNLIKELY.
WEDNESDAY INTO EARLY THURSDAY...THE NEXT HIGH PRESSURE SYSTEM
WILL SLOWLY PIVOT EAST OVER THE REGION, LEAVING US WITH TRANQUIL
WEATHER AND NEAR NORMAL TEMPERATURES.
THURSDAY AFTERNOON THROUGH SATURDAY...BOTH THE ECMWF AND GFS
CONTINUE TO SHOW A CUTOFF LOW DEVELOPING IN OVER THE SOUTHWESTERN
U.S. THROUGH THIS PERIOD AS THE NEXT UPPER LEVEL TROUGH CROSSES
THE COUNTRY. THE DIFFERENCE FROM YESTERDAY`S MODEL RUNS HOWEVER,
IS THAT BOTH MODELS ARE NOW EVEN SLOWER WITH THE CUTOFF LOW
(KEEPING IT GENERALLY OVER THE SOUTHERN PLAINS THROUGH THE END OF
THE WEEK), AND DO BRING A COLD FRONT THROUGH THE MID ATLANTIC
(ASSOCIATED WITH THE PROGRESSIVE NORTHERN STREAM TROUGH) NEXT
WEEKEND. THIS STILL SEEMS A BIT STRANGE OF A PATTERN FOR MID
APRIL, BUT WITH THE MODELS REMAINING CONSISTENT ON THIS SOLUTION,
FORECAST TRENDED CLOSER TO GFS AND ECMWF GUIDANCE. WHAT THIS MEANS
AS FAR AS IMPACTS FOR OUR REGION, WE COULD HAVE A PERIOD (AT THIS
POINT IT LOOKS TO BE DURING THE DAY FRIDAY) OF A HEAVY RAIN
THREAT. MODEL PRECIPITABLE WATER VALUES FOR THE 12 TO 18 HOURS
BEFORE THE COLD FRONT ARRIVES ARE WELL ABOVE NORMAL (GENERALLY
RANGING FROM 1 TO 1.3 INCHES AND THE 0 TO 6 KM MEAN WIND COULD BE
LESS THAN 20 KT AT LEAST THROUGH THE DAY FRIDAY. HOWEVER, THERE
REMAIN SEVERAL BIG QUESTION MARKS FOR THIS SYSTEM, PRIMARILY HOW
BIG OF A WINDOW WILL WE HAVE THE HIGHER PWAT VALUES BEFORE THE
COLD FRONT SWEEPS THROUGH. THEREFORE, HAVE NOT MENTIONED THIS IN
THE HWO AT THIS TIME.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THIS AFTERNOON...VFR. LIGHT/VARIABLE WINDS BECOMING SOUTHWEST 5-8
KNOTS. THE WIND SHOULD TURN MORE FROM THE SOUTH AT MAINLY KILG AND
KACY BY LATE IN THE AFTERNOON DUE TO AN INFLUENCE FROM A BAY/SEA
BREEZE.
TONIGHT...VFR. SOME HIGH CLOUDINESS SHOULD MOVE THROUGH. SOUTH-
SOUTHWEST WINDS 5 KNOTS OR LESS.
OUTLOOK...
MONDAY INTO TUESDAY...VFR CONDITIONS THROUGH THE DAY, WITH
CEILINGS LOWERING TO MVFR IN RAIN SHOWERS MONDAY NIGHT INTO
TUESDAY MORNING. VFR CONDITIONS RETURN BY TUESDAY AFTERNOON.
WEDNESDAY...VFR CONDITIONS EXPECTED.
THURSDAY...CEILINGS LOWERING TO MVFR POSSIBLE. CHANCE FOR RAIN
SHOWERS INCREASES LATE IN THE DAY.
&&
.MARINE...
NO MARINE FLAGS ARE ANTICIPATED THRU THE NR AND SHORT TERM
PDS WITH HIGH PRES OVER THE AREA THEN MOVG EWD OVER THE CSTL WATERS.
PK WIND GUSTS WILL BE IN THE 15 TO 20 KT RANGE WITH SEAS 1 TO 3 FT.
OUTLOOK...
MONDAY INTO TUESDAY...WIND GUSTS ABOVE 20 KT POSSIBLE WITH
SOUTHERLY WINDS MONDAY AFTERNOON AND EVENING. AN ABRUPT SHIFT TO
NORTHWESTERLY WINDS IS EXPECTED TUESDAY MORNING WITH A COLD FRONT.
GUSTS OF 15 TO 20 KT ARE POSSIBLE BEHIND THE FRONT.
WEDNESDAY...WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERIA.
THURSDAY...WINDS WILL BECOME EASTERLY THROUGH THE DAY AND
INCREASE. WIND GUSTS NEAR OR ABOVE 20 KT ARE POSSIBLE LATE IN THE
DAY. WITH THE WIND SPEED INCREASE, WAVE HEIGHTS MAY APPROACH 5 FT.
&&
.FIRE WEATHER...
TODAY, ANOTHER DRY DAY WITH AFTERNOON RH VALUES DROPPING BELOW 30
PERCENT FOR MUCH OF THE AREA, WHICH WILL CAUSE ADDITIONAL DRYING OF
THE FINE FUELS. HOWEVER, WIND SPEEDS ARE EXPECTED TO BE MUCH
LIGHTER, AVERAGING 5 TO 10 MPH.
FOR MONDAY, RELATIVE HUMIDITY VALUES NEAR OR BELOW 30 PERCENT ARE
EXPECTED FOR MUCH OF NJ AND SOUTHEASTERN PA. THE BIGGER QUESTION
THOUGH WILL BE WINDS. AT THIS POINT, DO NOT EXPECT THE STRONGEST
WIND GUSTS TO OCCUR UNTIL LATE AFTERNOON OR EARLY EVENING, WHEN
WE`VE ALREADY SEEN SOME RH RECOVERY. EVEN THEN WIND GUSTS WILL BE
MARGINAL UNTIL A COLD FRONT ARRIVES EARLY TUESDAY MORNING.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GORSE/JOHNSON
NEAR TERM...GORSE
SHORT TERM...NIERENBERG
LONG TERM...JOHNSON
AVIATION...GORSE/JOHNSON
MARINE...JOHNSON/NIERENBERG
FIRE WEATHER...JOHNSON/NIERENBERG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
945 AM EDT SUN APR 12 2015
.SYNOPSIS...
HIGH PRESSURE OVER OUR AREA WILL GRADUALLY SHIFT OFFSHORE THIS
AFTERNOON INTO TONIGHT. A COLD FRONT WILL THEN CROSS OUR AREA
TUESDAY MORNING. HIGH PRESSURE BUILDS OVER OUR REGION AND WILL
REMAIN IN PLACE THROUGH THURSDAY, THEN ANOTHER COLD FRONT IS
EXPECTED BY NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SPRAWLING AREA OF SURFACE HIGH PRESSURE OVER OUR REGION THIS
MORNING, WILL GRADUALLY SHIFT OFFSHORE DURING THIS AFTERNOON. AS
THIS OCCURS, THE LIGHT FLOW WILL TURN SOUTHWESTERLY ACROSS THE
REGION. THE 12Z STERLING, VA RAOB SHOWS A RATHER DRY AIRMASS IN
PLACE. THERE WAS A STRONG BUT SHALLOW INVERSION ALSO NOTED, HOWEVER
THIS HAS PRETTY MUCH QUICKLY ERODED AND THE SURFACE TEMPERATURES
HAVE REALLY JUMPED SO FAR THIS MORNING.
WHILE PLENTY OF SUNSHINE IS EXPECTED, THERE IS A SHORT WAVE ALONG
WITH SOME WAA ONGOING IN THE CENTRAL MISSISSIPPI VALLEY. THIS ALONG
WITH AN UPPER-LEVEL JET IS ASSISTING IN SOME HIGH LEVEL CLOUDS INTO
THE OHIO VALLEY. SOME OF THIS MAY ARRIVE IN OUR REGION AS WE GO
THROUGH THE AFTERNOON.
THE DRY AIRMASS AND AMPLE SUNSHINE WILL HELP BOOST TEMPERATURES WELL
INTO THE 60S FOR MUCH OF THE AREA. GIVEN THE LIGHTER FLOW THOUGH AND
AMPLE BOUNDARY LAYER HEATING, A SEA/BAY BREEZE SHOULD DEVELOP DURING
THE COURSE OF THIS AFTERNOON. AS A RESULT, TEMPERATURES WILL BE
COOLER ALONG THE COAST. THE HRRR AND RAP SHOW THE SURFACE FLOW
TURNING SOUTH-SOUTHEAST THIS AFTERNOON ALONG THE COAST IN RESPONSE.
THE HOURLY GRIDS WERE ADJUSTED BASED ON THE LATEST OBSERVATIONS,
THEN THE LAMP/LAV GUIDANCE WAS USED TO ASSIST. THIS INCLUDED SHOWING
A FASTER TEMPERATURE RISE SO FAR FOR MUCH OF THE CWA. THE DEW POINTS
SHOULD LOWER SOME WITH AMPLE BOUNDARY LAYER HEATING DESPITE LESS
MIXING TODAY. THE HRRR WAS USED TO ADJUST THE WINDS. NO MAJOR
CHANGES WERE MADE TO THE HIGH TEMPERATURES ATTM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE HIGH WILL CONTINUE TO MOVE EWD AS A CDFNT IN THE
MIDWEST ADVANCES EWD. EXPECT A GENLY CLEAR NIGHT WITH A MORE SWLY
FLOW SO TEMPS WONT BE AS CHILLY AS TONIGHT. CLOUDS SHUD INCREASE A
BIT IN WRN AREAS BY DAYBREAK.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
PRIMARY FOCUS IN THE LONG TERM WILL BE ON A COLD FRONT PASSAGE
MONDAY NIGHT INTO TUESDAY MORNING, AND A MUDDLED PATTERN THURSDAY
NIGHT INTO SATURDAY.
MONDAY...FIRST THOUGH, GOOD NEWS ABOUT MONDAY, IT WILL BE
BEAUTIFUL. WARM AIR ADVECTION EXPECTED AS THE HIGH SHIFTS OFF
SHORE AND THE LOW LEVEL FLOW SHIFTS TO SOUTHWESTERLY. THEREFORE,
MANY LOCATIONS SHOULD SEE HIGHS NEAR OR ABOVE 70. THE ABOVE NORMAL
TEMPERATURES, AND SOMEWHAT LIMITED MOISTURE ADVECTION COULD LEAD
TO MARGINAL FIRE WEATHER CONDITIONS (SEE FIRE WEATHER SECTION
BELOW), BUT OTHERWISE, IT SHOULD BE A NICE SPRING DAY.
MONDAY NIGHT INTO TUESDAY...MODELS REMAIN IN RELATIVELY GOOD
AGREEMENT WITH A COLD FRONT PUSHING THROUGH LATE MONDAY NIGHT INTO
TUESDAY MORNING. THE CENTER OF THE ASSOCIATED SURFACE LOW SHOULD
WILL MOVE ACROSS THE HUDSON BAY AREA, KEEPING MOST OF THE SYNOPTIC
SCALE LIFT WELL NORTH OF US. IN ADDITION, A PERSISTENT AND DEEP WARM
MID LAYER WILL LEAD TO VERY MINIMAL INSTABILITY. THUS, MUCH OF THE
REGION HAS ONLY A BRIEF WINDOW OF OPPORTUNITY WITH ISENTROPIC LIFT
AS THE FRONT MOVES THROUGH FOR ANY SHOWERS, AND THUNDERSTORMS, AT
LEAST IN OUR AREA ARE VERY UNLIKELY.
WEDNESDAY INTO EARLY THURSDAY...THE NEXT HIGH PRESSURE SYSTEM
WILL SLOWLY PIVOT EAST OVER THE REGION, LEAVING US WITH TRANQUIL
WEATHER AND NEAR NORMAL TEMPERATURES.
THURSDAY AFTERNOON THROUGH SATURDAY...BOTH THE ECMWF AND GFS
CONTINUE TO SHOW A CUTOFF LOW DEVELOPING IN OVER THE SOUTHWESTERN
U.S. THROUGH THIS PERIOD AS THE NEXT UPPER LEVEL TROUGH CROSSES
THE COUNTRY. THE DIFFERENCE FROM YESTERDAY`S MODEL RUNS HOWEVER,
IS THAT BOTH MODELS ARE NOW EVEN SLOWER WITH THE CUTOFF LOW
(KEEPING IT GENERALLY OVER THE SOUTHERN PLAINS THROUGH THE END OF
THE WEEK), AND DO BRING A COLD FRONT THROUGH THE MID ATLANTIC
(ASSOCIATED WITH THE PROGRESSIVE NORTHERN STREAM TROUGH) NEXT
WEEKEND. THIS STILL SEEMS A BIT STRANGE OF A PATTERN FOR MID
APRIL, BUT WITH THE MODELS REMAINING CONSISTENT ON THIS SOLUTION,
FORECAST TRENDED CLOSER TO GFS AND ECMWF GUIDANCE. WHAT THIS MEANS
AS FAR AS IMPACTS FOR OUR REGION, WE COULD HAVE A PERIOD (AT THIS
POINT IT LOOKS TO BE DURING THE DAY FRIDAY) OF A HEAVY RAIN
THREAT. MODEL PRECIPITABLE WATER VALUES FOR THE 12 TO 18 HOURS
BEFORE THE COLD FRONT ARRIVES ARE WELL ABOVE NORMAL (GENERALLY
RANGING FROM 1 TO 1.3 INCHES AND THE 0 TO 6 KM MEAN WIND COULD BE
LESS THAN 20 KT AT LEAST THROUGH THE DAY FRIDAY. HOWEVER, THERE
REMAIN SEVERAL BIG QUESTION MARKS FOR THIS SYSTEM, PRIMARILY HOW
BIG OF A WINDOW WILL WE HAVE THE HIGHER PWAT VALUES BEFORE THE
COLD FRONT SWEEPS THROUGH. THEREFORE, HAVE NOT MENTIONED THIS IN
THE HWO AT THIS TIME.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF TODAY...VFR. LIGHT/VARIABLE TO LIGHT NORTHWEST WINDS,
BECOMING WEST AND SOUTHWEST 5-8 KNOTS. THE WIND SHOULD TURN MORE
FROM THE SOUTH AT MAINLY KILG AND KACY BY LATE IN THE AFTERNOON DUE
TO AN INFLUENCE FROM A BAY/SEA BREEZE.
TONIGHT...VFR. SOME HIGH CLOUDINESS SHOULD MOVE THROUGH. SOUTH-
SOUTHWEST WINDS 5 KNOTS OR LESS.
OUTLOOK...
MONDAY INTO TUESDAY...VFR CONDITIONS THROUGH THE DAY, WITH
CEILINGS LOWERING TO MVFR IN RAIN SHOWERS MONDAY NIGHT INTO
TUESDAY MORNING. VFR CONDITIONS RETURN BY TUESDAY AFTERNOON.
WEDNESDAY...VFR CONDITIONS EXPECTED.
THURSDAY...CEILINGS LOWERING TO MVFR POSSIBLE. CHANCE FOR RAIN
SHOWERS INCREASES LATE IN THE DAY.
&&
.MARINE...
NO MARINE FLAGS ARE ANTICIPATED THRU THE NR AND SHORT TERM
PDS WITH HIGH PRES OVER THE AREA THEN MOVG EWD OVER THE CSTL WATERS.
PK WIND GUSTS WILL BE IN THE 15 TO 20 KT RANGE WITH SEAS 1 TO 3 FT.
OUTLOOK...
MONDAY INTO TUESDAY...WIND GUSTS ABOVE 20 KT POSSIBLE WITH
SOUTHERLY WINDS MONDAY AFTERNOON AND EVENING. AN ABRUPT SHIFT TO
NORTHWESTERLY WINDS IS EXPECTED TUESDAY MORNING WITH A COLD FRONT.
GUSTS OF 15 TO 20 KT ARE POSSIBLE BEHIND THE FRONT.
WEDNESDAY...WINDS AND SEAS SHOULD REMAIN BELOW SCA CRITERIA.
THURSDAY...WINDS WILL BECOME EASTERLY THROUGH THE DAY AND
INCREASE. WIND GUSTS NEAR OR ABOVE 20 KT ARE POSSIBLE LATE IN THE
DAY. WITH THE WIND SPEED INCREASE, WAVE HEIGHTS MAY APPROACH 5 FT.
&&
.FIRE WEATHER...
TODAY, ANOTHER DRY DAY WITH AFTERNOON RH VALUES DROPPING BELOW 30
PERCENT FOR MUCH OF THE AREA, WHICH WILL CAUSE ADDITIONAL DRYING OF
THE FINE FUELS. HOWEVER, WIND SPEEDS ARE EXPECTED TO BE MUCH
LIGHTER, AVERAGING NEAR 10 MPH.
FOR MONDAY, RELATIVE HUMIDITY VALUES NEAR OR BELOW 30 PERCENT ARE
EXPECTED FOR MUCH OF NJ AND SOUTHEASTERN PA. THE BIGGER QUESTION
THOUGH WILL BE WINDS. AT THIS POINT, DO NOT EXPECT THE STRONGEST
WIND GUSTS TO OCCUR UNTIL LATE AFTERNOON OR EARLY EVENING, WHEN
WE`VE ALREADY SEEN SOME RH RECOVERY. EVEN THEN WIND GUSTS WILL BE
MARGINAL UNTIL A COLD FRONT ARRIVES EARLY TUESDAY MORNING.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GORSE/JOHNSON
NEAR TERM...GORSE
SHORT TERM...NIERENBERG
LONG TERM...JOHNSON
AVIATION...GORSE/JOHNSON
MARINE...JOHNSON/NIERENBERG
FIRE WEATHER...JOHNSON/NIERENBERG
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
125 AM EDT SUN APR 12 2015
.SYNOPSIS...
A STATIONARY FRONT WILL LINGER NEAR THE SAVANNAH RIVER TONIGHT AND
SUNDAY...THEN LIFT BACK NORTH AS A WARM FRONT MONDAY AND TUESDAY.
A COLD FRONT WILL CROSS THE REGION DURING MID WEEK. A HIGH
PRESSURE WEDGE DEVELOP BEHIND THE FRONT INTO LATE IN THE
WEEK...BEFORE ANOTHER COLD FRONT IMPACTS THE AREA NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
12/04Z SURFACE ANALYSIS AND RAP INSTABILITY PROGS PLACED THE COLD
FRONT ALONG THE SAVANNAH RIVER. THE FRONT AS ESSENTIALLY BECOME
STATIONARY OVER THE PAST FEW HOURS WITH NEUTRAL PRESSURE TRENDS
NOTED UPSTREAM. THE FRONT MAY DRIFT A BIT MORE TO THE SOUTH
THROUGH SUNRISE...BUT IT WILL ESSENTIALLY REMAIN STATIONARY. HIGH
RESOLUTION MODELS SHOW ISOLATED SHOWERS AND POSSIBLY A TSTM OR TWO
DEVELOPING IN THE VICINITY OF THE FRONT PRIOR TO SUNRISE. WILL
SHOW SLIGHT CHANCE POPS FOR THE COUNTIES BORDERING THE SAVANNAH
RIVER TO ACCOUNT FOR THIS. OTHER AREAS SHOULD REMAIN
DRY...ESPECIALLY FAR NORTHERN AREAS WHERE DEWPOINTS HAVE FALLEN
INTO THE MID-UPPER 50S.
THERE ARE A LARGE RANGE OF TEMPERATURES EARLY THIS MORNING...
RANGING FROM THE UPPER 50S ACROSS UPPER PORTIONS OF DORCHESTER
AND BERKELEY COUNTIES TO AROUND 70 ACROSS INTERIOR SOUTHEAST
GEORGIA. SINCE THE FRONT WILL MOVE LITTLE OVERNIGHT...A SLIGHT
UPWARD ADJUSTMENT IS NEEDED FOR OVERNIGHT LOWS ACROSS SOUTHEAST
GEORGIA. LOWS WILL RANGE FROM THE UPPER 50S FAR NORTH... LOWER 60S
ALONG THE LOWER SOUTH CAROLINA COAST WITH MID 60S SOUTHEAST
GEORGIA.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
SUNDAY...THE COLD FRONT WILL STALL NEAR OR NOT FAR TO THE SOUTH OF
THE ALTAMAHA RIVER AS IT RUNS INTO MID LEVEL RIDGING AND BECOMES
GENERALLY PARALLEL TO THE FLOW ALOFT. AT THE SAME TIME A LARGE AND
FAIRLY DECENT HIGH PRESSURE RIDGE WILL PUSH EAST THROUGH THE
DELMARVA...WITH SOME INDICATIONS OF A WEAK AND TRANSIENT WEDGE TO
DEVELOP INLAND FROM THE CWFA. INCREASING ISENTROPIC ASCENT...MOST
NOTABLY ON THE 295K AND 300K SURFACES...OR ABOUT 3500-6000 FT WILL
DEVELOP ACROSS THE REGION. THIS WILL OCCUR SIMULTANEOUSLY IN WITH AN
INFLUX OF MARINE MOISTURE WITH AN EASTERLY SYNOPTIC FEED OFF THE
ATLANTIC. THIS WILL RESULT IN A SLIGHT CHANCE/CHANCE POPS TO THE
SOUTH OF I-16 DURING THE LATE MORNING/AFTERNOON IN CLOSER PROXIMITY
TO THE BAROCLINIC ZONE AND THE DEEPEST MOISTURE. FURTHER NORTH THERE
IS TOO MUCH LARGE SCALE SUBSIDENCE UNDERNEATH AND LESS MOISTURE THAN
FURTHER SOUTH. STILL...WITH LOW LEVEL CONVERGENCE OFF THE ATLANTIC
THERE STILL COULD BE SOME SHOWERS THAT DEVELOP INTO PARTS OF COASTAL
SC. THERMODYNAMICS AND SHEAR IS MINIMAL...SO THERE ISN/T TOO MUCH
RISK FOR THUNDER. BUT SINCE IT WAS ALREADY IN THE FORECAST WE HAVE
MAINTAINED A SLIGHT RISK FOR THE AFTERNOON OVER FAR SOUTHERN ZONES.
CLOUD COVER WILL INCREASE FROM SOUTH/SE TO NORTH/NW AND WILL PLAY A
BIG ROLE IN HOW WARM TEMPS ARE ABLE TO REACH. FOR NOW WE HAVE MID
AND UPPER 70S INLAND FROM THE COOLER BARRIER ISLAND COMMUNITIES.
WINDS WILL ALSO BECOME GUSTY ACROSS THE COASTAL COUNTIES WHERE
DECENT PINCHING WILL TRANSPIRE BETWEEN THE FRONT AND THE INLAND
WEDGE. MAX GUSTS WILL HIT 25 OR EVEN 30 MPH.
SUNDAY NIGHT...SHORT WAVE RIDGING WILL AMPLIFY OVERHEAD WHILE THE
CORE OF THE HIGH PULLS FURTHER OFFSHORE AND TO THE SOUTH OF LONG
ISLAND. BUT ITS ASSOCIATED RIDGING MAINTAINS ITS GRIP INLAND OVER
THE SE...WHILE THE STATIONARY FRONT TO THE SOUTH BEGINS TO SLIP A
LITTLE NORTHWARD. HOW QUICKLY THIS TRANSITION OCCURS WILL DETERMINE
WHEN RAIN CHANCES WILL SPREAD FURTHER NORTHWARD. ISENTROPIC UPGLIDE
WILL INCREASE FURTHER THROUGH THE NIGHT...WHILE LOW LEVEL
CONVERGENCE STRENGTHENS AND THE ONSHORE TRAJECTORIES DEEPEN FURTHER.
THIS WILL ALLOW FOR RAIN CHANCES TO GRADUALLY CLIMB...MAINLY INTO
THE SLIGHT CHANCE RANGE NORTH/NW AND THE CHANCE RANGE SOUTH/SE.
SOUNDING PROFILES ARE SUGGESTIVE OF POSSIBLE STRATUS BUILD-DOWN
THUNDERSTORM REDEVELOPMENT/ECHO TRAINING COULD PRODUCE LOCALLY
HEAVY RAINFALL...ESPECIALLY SOUTH OF I-16. THE LACK OF STRONG
INSTABILITY SHOULD LIMIT THE SEVERE POTENTIAL...ALTHOUGH LOCALIZED
BOUNDARY INTERACTIONS COULD SUPPORT AN ISOLATED PULSE SEVERE
THUNDERSTORM SOUTH OF THE FRONT UNTIL LATER THIS EVENING.
AS THE COLD FRONT CONTINUES TO ADVANCE DEEPER INTO THE FORECAST
AREA...COVERAGE OF SHOWERS/THUNDERSTORMS WILL BECOME LIMITED TO
FAR SOUTHERN COUNTIES...AND DIURNAL COOLING/STABILIZATION SHOULD
END THE THREAT FOR ADDITIONAL THUNDERSTORMS BY LATE EVENING.D-DOWN AND
THIS MIGHT LEAD TO SOME FOG CONCERNS LATE. TEMPS WILL BE SIMILAR TO
WHAT IS ANTICIPATED FOR TONIGHT...LOWS ABOUT 10F ABOVE NORMAL.
MONDAY AND MONDAY NIGHT...SHORT WAVE RIDGING ALOFT WILL SLIDE INTO
THE ATLANTIC AND SHORT WAVE ENERGY WILL EJECT EASTWARD FROM THE CUT
OFF LOW OVER THE SOUTHERN GREAT PLAINS. THIS ALLOWS FOR SOME GRADUAL
PROGRESSION TO THE SURFACE SCENARIO...FORCING THE SURFACE HIGH TO
PULL MORE EASTWARD AND ALLOWS THE FRONT TO THE SOUTH TO TRANSITION
INTO A WARM FRONT THAT LIFTS INTO AND NORTH OF THE LOCAL AREA. THERE
IS SUBTLE FORCING AS THE SHORT WAVE ARRIVES LATE MONDAY INTO MONDAY
NIGHT...ALONG WITH CONTINUED ISENTROPIC ASCENT ON SEVERAL DIFFERENT
SURFACES. ADDITIONAL FORCING WILL RESULT DUE TO THE WARM FRONT IN
SYNC WITH PWATS THAT CLIMB TO MORE THAN 1.75 INCHES...SOME 1-2
STANDARD DEVIATIONS ABOVE NORMAL. THIS WILL SUPPORT AT LEAST 30-50
POPS EVERYWHERE...ALTHOUGH ONCE WE HAVE A BETTER IDEA ON EXACT
TRENDS THESE VALUES COULD BE RAISED IN FUTURISTIC FORECASTS.
THERMODYNAMICS AND SHEAR ARE AGAIN LIMITED...SO NO MORE THAN MAINLY
DIURNAL AND ISOLATED T-STORMS ARE PRESENTLY ANTICIPATED.
CONSIDERABLE CLOUD COVER WILL HOLD THE DIURNAL RANGE OF TEMPS TO
ONLY ABOUT 10-14F...WITH ABOVE NORMAL VALUES AT NIGHT AND NEAR OR
SLIGHTLY ABOVE NORMAL DURING THE DAYTIME. STRATUS BUILD-DOWN COULD
AGAIN LEAD TO SOME FOG CONCERNS.
THUNDERSTORM REDEVELOPMENT/ECHO TRAINING COULD PRODUCE LOCALLY
HEAVY RAINFALL...ESPECIALLY SOUTH OF I-16. THE LACK OF STRONG
INSTABILITY SHOULD LIMIT THE SEVERE POTENTIAL...ALTHOUGH LOCALIZED
BOUNDARY INTERACTIONS COULD SUPPORT AN ISOLATED PULSE SEVERE
THUNDERSTORM SOUTH OF THE FRONT UNTIL LATER THIS EVENING.
AS THE COLD FRONT CONTINUES TO ADVANCE DEEPER INTO THE FORECAST
AREA...COVERAGE OF SHOWERS/THUNDERSTORMS WILL BECOME LIMITED TO
FAR SOUTHERN COUNTIES...AND DIURNAL COOLING/STABILIZATION SHOULD
END THE THREAT FOR ADDITIONAL THUNDERSTORMS BY LATE EVENING.IDE INTO
THE ATLANTIC AND SHORT WAVE ENERGY WILL EJECT EASTWARD FROM THE CUT
OFF LOW OVER THE SOUTHERN GREAT PLAINS. THIS ALLOWS FOR SOME GRADUAL
PROGRESSION TO THE SURFACE SCENARIO...FORCING THE SURFACE HIGH TO
PULL MORE EASTWARD AND ALLOWS THE FRONT TO THE SOUTH TO TRANSITION
INTO A WARM FRONT THAT LIFTS INTO AND NORTH OF THE LOCAL AREA. THERE
IS SUBTLE FORCING AS THE SHORT WAVE ARRIVES LATE MONDAY INTO MONDAY
NIGHT...ALONG WITH CONTINUED ISENTROPIC ASCENT ON SEVERAL DIFFERENT
SURFACES. ADDITIONAL FORCING WILL RESULT DUE TO THE WARM FRONT IN
SYNC WITH PWATS THAT CLIMB TO MORE THAN 1.75 INCHES...SOME 1-2
STANDARD DEVIATIONS ABOVE NORMAL. THIS WILL SUPPORT AT LEAST 30-50
POPS EVERYWHERE...ALTHOUGH ONCE WE HAVE A BETTER IDEA ON EXACT
TRENDS THESE VALUES COULD BE RAISED IN FUTURISTIC FORECASTS.
THERMODYNAMICS AND SHEAR ARE AGAIN LIMITED...SO NO MORE THAN MAINLY
DIURNAL AND ISOLATED T-STORMS ARE PRESENTLY ANTICIPATED.
CONSIDERABLE CLOUD COVER WILL HOLD THE DIURNAL RANGE OF TEMPS TO
ONLY ABOUT 10-14F...WITH ABOVE NORMAL VALUES AT NIGHT AND NEAR OR
SLIGHTLY ABOVE NORMAL DURING THE DAYTIME. STRATUS BUILD-DOWN COULD
AGAIN LEAD TO SOME FOG CONCERNS.
TUESDAY...A COLD FRONT NEAR OR JUST EAST OF THE CENTRAL AND SOUTHERN
APPALACHIANS AT THE START OF THE DAY WILL TRAVERSE SLOWLY
EASTWARD...BUT HAS IT BECOMES ORIENTED TO THE QUASI-ZONAL FLOW ALOFT
IT WILL BE A SLOW TRANSITION. EVEN SO...THE FORCING ASSOCIATED WITH
THE APPROACHING FRONT AND INDICATIONS OF A BETTER DEFINED SHORT WAVE
ALOFT WILL OCCUR IN CONJUNCTION WITH DEEP AND RICH SUB-TROPICAL
MOISTURE CHARACTERIZED BY PWATS AROUND 2 STANDARD DEVIATIONS ABOVE
MID-APRIL NORMS. THIS WILL RESULT IN SCATTERED TO NUMEROUS
SHOWERS...PERHAPS WITH SOME LOCALLY HEAVY RAINS GIVEN THE HIGH
MOISTURE CONTENT AND GOOD 850 MB MOISTURE FLUX CONVERGENCE.
THERMODYNAMICS AND SHEAR ARE AGAIN RESTRICTED DUE TO PLENTIFUL CLOUD
COVER...BUT WITH DEW POINTS WELL INTO THE 60S THERE MIGHT BE A
LITTLE BETTER LOW LEVEL INSTABILITY AND CAPE. THUS WE HAVE SLIGHT
CHANCE AND CHANCE OF THUNDERSTORMS. WARM ADVECTION AND EVEN SOME
COMPRESSIONAL HEATING OUT AHEAD OF THE FRONT WILL ALLOW FOR MAX
TEMPS TO REACH 75-80 AWAY FROM THE BEACHES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE LONG TERM PERIOD LOOKS FAIRLY UNSETTLED. A COLD FRONT WILL PUSH
EAST OFF THE COAST TUESDAY NIGHT...WITH HIGH PRESSURE BUILDING IN
FROM THE NORTHWEST IN ITS WAKE ON WEDNESDAY. THE HIGH WILL SHIFT
INTO THE ATLANTIC THURSDAY...WHILE A WEAK COASTAL TROUGH DEVELOPS.
WITH FAVORABLE MOISTURE AND ADDITIONAL FORCING FROM A SERIES OF
SHORTWAVES PROGGED TO EJECT FROM THE SOUTHWEST...SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE EACH DAY. MODELS ARE IN DISAGREEMENT
TOWARDS THE END OF THE PERIOD...HOWEVER ANOTHER COLD FRONT LOOKS TO
IMPACT THE AREA ON FRIDAY OR SATURDAY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
KCHS...VFR. CLOUDS WILL THICKEN AND LOWER THROUGH THE DAY...BUT
THERE ARE NO CONCERNS.
KSAV...WATCHING AN AREA OF MVFR CIGS AT KHXD-KNBC-KARW. THESE
CLOUDS ARE JUST BEHIND A STATIONARY FRONT...WHICH IS POSITIONED
NEAR THE TERMINAL. THINK THESE CIGS WILL REMAIN NORTH OF THE
TERMINAL THROUGH SUNRISE...BUT THIS NEEDS TO BE WATCHED. ISOLATED
SHOWERS/TSTMS ARE PROGGED TO DEVELOP PRIOR TO SUNRISE ALONG OR
JUST NORTH OF THE SAVANNAH RIVER. WILL CARRY VCSH 09-15Z FOR NOW.
SCATTERED SHOWERS/TSTMS WILL DEVELOP SOUTH OF THE FRONT TODAY...
BUT IT IS NOT ENTIRE CLEAR IF MOST OF THIS ACTIVITY WILL REMAIN
INLAND FROM THE TERMINAL. PREFER TO KEEP PRECIP OUT OF THE 06Z TAF
FOR NOW...BUT THIS WILL BE REEVALUATE WITH THE 12Z TAF CYCLE.
EXTENDED AVIATION OUTLOOK...AS A WARM FRONT APPROACHES FROM THE
SOUTH...STRATUS BUILD-DOWN IS POSSIBLE SUNDAY NIGHT INTO MONDAY
MORNING...ESPECIALLY AT KSAV. IF IT DOES OCCUR THEN SUB-VFR
WEATHER WOULD DEVELOP. OTHERWISE... FLIGHT RESTRICTIONS LIKELY AT
TIMES DURING THE EARLY AND MIDDLE PARTS OF NEXT WEEK AS SHOWERS
AND T-STORMS RETURN.
&&
.MARINE...
OVERNIGHT...A COLD FRONT WHICH HAS PASSED THROUGH AMZ330-AMZ350
WILL SLOWLY PUSH SOUTH OVERNIGHT. SOUTH OF THE FRONT...S/SE WINDS
WILL REMAIN 10 KT OR LESS. NORTH OF THE FRONT...E-NE WINDS SHOULD
GRADUALLY INCREASE...BUT SMALL CRAFT ADVISORY CONDITIONS SHOULD
HOLD OFF UNTIL AT LEAST SUNDAY MORNING.
SUNDAY...A 1030 MB HIGH PULLING EAST THROUGH THE DELMARVA WILL
EXTEND SOUTH/SW AND INLAND OVER THE SE STATES...WHILE A STATIONARY
FRONT HOLDS NOT FAR TO THE SOUTH. THIS WILL GENERATE A TIGHTENING OF
THE PRESSURE GRADIENT...ENOUGH SO THAT WE HAVE RAISED THE SMALL
CRAFT ADVISORY FLAGS FOR CHARLESTON HARBOR AND THE CHARLESTON
COUNTY WATERS OUT 20 NM. NE/EAST WINDS WILL CLIMB TO NEAR 20 KT WITH
GUSTS AROUND 25 KT...ENOUGH FOR THE ADVISORY. MEANWHILE FURTHER
SOUTH...WE/LL LIKELY BE JUST BELOW ANY ADVISORY THRESHOLDS ON THE
AMZ352-354 WATERS UNLESS THE STRONGER PINCHING IS FORCED FURTHER
SOUTH. BUT A FAVORABLE FETCH WILL PUSH SEAS UP TO 6 FT ACROSS THE
OUTER GA WATERS...AND WE HAVE A SMALL CRAFT ADVISORY THERE BEGINNING
IN THE AFTERNOON FOR THOSE CONDITIONS. ISOLATED TO SCATTERED
SHOWERS/T-STORMS WILL BE FOUND ON THE GA WATERS.
SUNDAY NIGHT...IT/LL BE A VERY SLOW TRANSITION BETWEEN THE FRONT TO
THE SOUTH ATTEMPTING TO CHANGE INTO A WARM FRONT AND LIFTING BACK
NORTH...WHILE THE BLOCKING RIDGE HOLDS IN PLACE TO THE NORTH. WITH
TIME THE GRADIENT WILL BEGIN TO SLACKEN...BUT UNTIL THEN WE STILL
HAVE THE PREVIOUS SMALL CRAFT ADVISORIES GOING INTO THE NIGHT.
ISOLATED TO SCATTERED SHOWERS AND T-STORMS WILL ALSO OVERSPREAD THE
LOCAL WATERS.
MONDAY THROUGH TUESDAY...THE SYNOPTIC PATTERN UNDERGOES GRADUAL
CHANGES...AS THE WARM FRONT LIFTS NORTH IN RESPONSE TO THE RIDGE TO
THE NORTH PULLING EAST. UPSTREAM A COLD FRONT WILL APPROACH FROM THE
WEST/NW BY LATE IN THE PERIOD. WINDS AND SEAS LOOK TO REMAIN BELOW
ANY ADVISORY THRESHOLDS AS AN EASTERLY FETCH CLOCKS AROUND TO THE
SOUTH/SW. SCATTERED CONVECTION WILL AGAIN PREVAIL THROUGH THE PERIOD.
WEDNESDAY THROUGH THURSDAY...THE AFOREMENTIONED COLD FRONT WILL
STALL OVER OR JUST SOUTH/SE OF THE MARINE COMMUNITY...AS A STRONGER
HIGH PRESSURE WEDGE DEVELOPS INLAND BEHIND THE FRONT. THE PACKING OF
THE PRESSURE GRADIENT WILL BECOME ENHANCED AND AT LEAST SMALL CRAFT
ADVISORIES WILL BE REQUIRED.
RIP CURRENTS...ALTHOUGH THE RISK LOOKS MARGINAL...GIVEN EAST/NE
WINDS OF 15-20 MPH AND GUSTY AND SWELLS OF 2-3 FT EVERY 8-9 SECONDS
WE HAVE GONE WITH OUR FIRST MODERATE RISK OF RIP CURRENTS OF THE
SEASON. BE SAFE IF AT THE BEACH...AND DON/T GO IN THE WATER IF CAN/T
SWIM.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 11 PM EDT THIS
EVENING FOR AMZ330.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 7 AM EDT
MONDAY FOR AMZ374.
SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 1 AM EDT MONDAY
FOR AMZ350.
&&
$$
ST
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1054 PM CDT Mon Apr 13 2015
.UPDATE...
ISSUED AT 825 PM CDT MON APR 13 2015
Extensive area of mid and high level cloudiness across central
through southeast Illinois as low pressure tracks well to our
south tonight. Main forecast concern will be how far north the
next batch of rain will push later tonight into Tuesday morning
as the wave passes south of our area. Latest HRRR and Rapid Refresh
models were trending a bit further north with the rain area with
areas along and south of I-70 probably seeing another round of
light rain by Tuesday morning. Will increase the POPs accordingly
over the I-70 counties after midnight. Further north, high pressure
will move across the southern Great Lakes with quite a bit of dry
air advecting south into our region overnight. Cloud cover should
keep temperatures from getting much colder than our current early
morning lows, but our far northern counties, where cloud cover will
be rather thin, may see some upper 30s by morning. Will make the
POP adjustments over our far southeast counties for late tonight
into Tuesday morning. Have already sent out some updated grids for
more cloud cover across the forecast area through Tuesday morning.
Should have the updated ZFP out soon.
&&
.SHORT TERM...(Tonight)
ISSUED AT 243 PM CDT MON APR 13 2015
19z/2pm surface analysis shows cold front departing the far SE KILX
CWA, with showers lingering along and just behind the boundary.
Based on radar timing tools and latest run of the HRRR, it appears
the showers will slip southeast of Lawrenceville by 00z. Will
therefore go with a dry forecast across the board for tonight. Band
of low clouds associated with the showers will exit the area as
well: however, plenty of high clouds will linger well behind the
front. Latest satellite imagery shows this trend quite well, with
thick cirrus seen as far northwest as central Iowa. End result will
be a high/thin overcast for much of the night, with a gradual NW to
SE clearing trend overnight. Low temperatures will range from the
upper 30s northwest of the Illinois River around Galesburg to near
50 degrees far southeast around Lawrenceville.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 243 PM CDT MON APR 13 2015
Main challenges remain with timing of precipitation chances later
this week. Latest GFS has shown a significant shift from its
previous runs in regards to the piece of energy that will be coming
onto the Pacific Northwest coast shortly, trending more toward the
ECMWF/NAM/Canadian solutions of a cutoff low over the central Rockies
by midweek. However, there are still a few differences with the
disposition of this low later in the week. Main storm track will be
along the Canadian border and upper Midwest, resulting in the low
generally meandering northeast. The GFS, which had been very
progressive later this week, is now the slowest and strongest of the
bunch, with the strong low making it as far as Arkansas by early
Sunday, while the ECMWF and Canadian models generally weaken the low
in place over west Texas/east New Mexico. That aspect results in
quite a bit of uncertainty with the PoP`s later in the weekend, but
the general model consensus is for backing down on some of the
chances in the near term.
High pressure drifting across the Midwest will keep the region dry
through much of Wednesday. Current upper low over southeast tip of
New Mexico will be shearing out, with the models bringing the
remnants into the mid-Mississippi Valley late Wednesday/early
Thursday. The ECMWF is most robust with the remaining energy and
thus have a wetter passage, while the GFS/Canadian models are
largely dry and the NAM has only small rain chances. Have focused
the rain chances mainly on Wednesday night and lowered them a bit,
as there will be a persistent east flow which will stifle the column
moistening a good part of the night. Any lingering showers should
exit early Thursday.
Heading into the weekend, most likely time frame for precipitation
would be Friday night, but confidence is still low as mentioned
earlier, and will keep the rain chances at silent 20s for now. The
differences widen by Sunday due to the much stronger GFS, which
provides a blustery/showery solution for us while the ECMWF remains
dry until Sunday evening. Did mention some 25-30% PoP`s for Sunday,
although much lower than the blended initialization would suggest.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1050 PM CDT MON APR 13 2015
VFR conditions are expected to prevail through this forecast
period. High pressure will drift across the lower Great Lakes
over the next 24 hours keeping the weather quiet for the TAF
locations. A weather disturbance passing south of the Ohio
River late tonight through Tuesday morning will keep quite a
bit of mid and high level cloud cover over most of the area
into Tuesday morning. Surface flow will be light northerly
tonight and northeast at 7 to 12 kts on Tuesday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...Barnes
LONG TERM...Geelhart
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1002 PM CDT MON APR 13 2015
.SHORT TERM...
210 PM CDT
THROUGH TUESDAY NIGHT...
SATELLITE IMAGERY THIS AFTERNOON SHOWS THE CHANNEL OF CLOUDS
STRETCHING FROM HUDSON BAY CANADA SOUTH THROUGH THE OHIO
VALLEY...WITH THE BOUNDARY STEADILY PUSHING EAST. ON THE HEELS OF
THE DEPARTING BOUNDARY IS A BROAD ANTI-CYCLONIC RIDGE...WHICH IS
POISED TO ARRIVE THIS EVENING AND PERSIST THROUGH MID-WEEK. THROUGH
THIS AFTERNOON THE LEADING EDGE OF THE SFC RIDGE WILL REMAIN OVER
THE CWFA...ALLOWING SLIGHTLY TIGHTER PRESSURE GRADIENT TO CREATE
OCCASIONALLY GUSTY WEST/NORTHWEST WINDS. TEMPS BEHIND THE FRONTAL
BOUNDARY ARE RATHER UNIFORM IN THE LOW/MID 60S WITH DEW POINTS
FALLING INTO THE LOW 30S.
HIGH PRESSURE WILL PROVIDE MINIMAL CLOUD COVER THRU TUE NGT...WITH
SEASONAL TEMPS IN THE 60S. AS THE SFC RIDGE AXIS BEGINS TO DRIFT
NORTHEAST TUE...THIS WILL ALLOW WINDS TO TURN NORTH/NORTHEAST.
LIKELY KEEPING MUCH COOLER TEMPS ALONG THE IMMEDIATE LAKESHORE.
CONFIDENCE...HIGH.
BEACHLER
&&
.LONG TERM...
210 PM CDT
WEDNESDAY THROUGH MONDAY...
A DEVELOPING 500MB TROUGH ACROSS THE FOUR-CORNERS REGION OF THE
CONUS...WILL HELP TO TRANSITION THE SEMI- ZONAL FLOW TO A SLIGHT
SOUTHWEST ORIENTATION. THE SFC RIDGE WILL BE STEADILY SLIDING
NORTHEAST WED AFTN...WITH A SLOW ARRIVAL TO RETURN FLOW MOISTURE
WED NGT. MOISTURE WILL CONTINUE TO POOL ALONG THE WESTERN
PERIPHERY OF THE DEPARTING SFC RIDGE...AS THE 500MB VORT REMAINS
PARKED ACROSS THE SOUTHWEST CONUS THUR/FRI. THIS WILL ALLOW A
SERIES OF WEAK IMPULSES TO LIFT NORTHEAST AND BRING CHANCES FOR
SHRA/TSRA. FRI INTO SAT LOOKS TO BE BETWEEN MID-LVL
WAVES...HOWEVER BY SAT A NORTHERN STREAM MID-LVL WAVE WILL BE
DIGGING SOUTHEAST ACROSS THE NORTHERN PLAINS...THIS COULD BLEND
WITH A SOUTHERN STREAM WAVE AND BRING ANOTHER ROUND OF SHRA/TSRA
TO THE REGION FOR THE UPCOMING WEEKEND. TEMPS THRU THE EXTENDED
PERIOD REMAIN SEASONAL...HOWEVER WITH THE NORTHERN STREAM BECOMING
ACTIVE...TEMPS MAY BEGIN TO COOL FOR THE UPCOMING WEEKEND.
CONFIDENCE IN TEMPERATURES...HIGH.
CONFIDENCE IN PRECIPITATION...MEDIUM.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* LIGHT WEST-NORTHWEST WINDS BECOMING NORTHEAST BY TUESDAY
MONRING...WITH A LAKE BREEZE PUSH AND WINDS NEAR 10 KT TUESDAY
AFTERNOON.
RATZER
//DISCUSSION...UPDATED 00Z...
SURFACE HIGH PRESSURE EXTENDS FROM NEBRASKA EAST ACROSS PARTS OF
CENTRAL IL/NORTHERN IN EARLY THIS EVENING. NORTH OF THE SURFACE
RIDGE AXIS...GUSTY WEST-NORTHWEST WINDS HAVE BEEN COMMON ACROSS
THE TERMINALS. GUSTS HAVE DECREASED QUICKLY IN THE PAST HOUR OR
SO...AND SHOULD CONTINUE TO DIMINISH EARLY THIS EVENING SUNSET
APPROACHES AND AS THE GRADIENT WEAKENS AS THE SURFACE HIGH
MOVES TOWARD THE AREA. WHILE EXTENSIVE HIGH CLOUD WILL BE ACROSS
ESPECIALLY THE CHICAGO TERMINALS...LOW LEVELS ARE QUITE DRY AND
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD.
WINDS WILL SHIFT TO THE NORTH-NORTHEAST BY TUESDAY MORNING AND
WILL BECOME MORE TRUE NORTHEAST DURING THE DAY AS THE HIGH LIFTS
TO THE NORTHEAST ACROSS THE GREAT LAKES. THE GRADIENT WILL BE
WEAK WITH LIGHT WINDS NEAR THE CENTER OF THE HIGH MIDDAY...THOUGH
A LAKE BREEZE PUSH WILL LIKELY DEVELOP BY EARLY-MID AFTERNOON
WHICH WILL LIKELY RESULT IN A PERIOD OF NORTHEAST OR EAST-
NORTHEAST WINDS NEAR 10 KTS FOR A TIME. LIGHT EAST-NORTHEAST WINDS
WILL CONTINUE TUESDAY EVENING.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM-HIGH CONFIDENCE IN LAKE BREEZE DETAILS TUESDAY.
* HIGH CONFIDENCE ALL OTHER ELEMENTS.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. BECOMING MVFR WEDNESDAY NIGHT WITH SHRA/TSRA.
EAST WINDS.
THURSDAY...SHRA/TSRA ENDING. MVFR POSSIBLE BUT BECOMING VFR.
LIGHT EAST WINDS.
FRIDAY...VFR. SLGT CHANCE OF SHRA FRIDAY NIGHT. LIGHT NORTHEAST
WINDS.
SATURDAY...VFR. NORTHEAST WINDS.
SUNDAY...VFR. CHANCE SHRA. EAST-SOUTHEAST WINDS.
RATZER
&&
.MARINE...
222 PM CDT
THE COLD FRONT HAS CLEARED THE LAKE EARLY THIS AFTERNOON RESULTING
IN WEST WINDS TO 25 KT. EXPECT A STEADY DECLINE IN WINDS LATE
THIS AFTERNOON AND EVENING AS HIGH PRESSURE OVER THE PLAINS WORKS
EASTWARD. THE CENTER OF HIGH PRESSURE WILL PASS OVER THE SOUTHERN
HALF OF THE LAKE ON TUESDAY. THIS WILL RESULT IN ONSHORE WINDS
ACROSS MUCH OF THE LAKE DUE TO THE LIGHT PRESSURE GRADIENT. THE
HIGH WILL SHIFT EAST ON WEDNESDAY AND MERGE WITH HIGH PRESSURE
JUST EAST OF HUDSON BAY...WHICH WILL RESULT IN A STEADIER
SOUTHEAST TO SOUTH WIND ACROSS THE LAKE. SEVERAL WEAK LOWS WILL
PASS BY TO THE NORTH OF THE LAKE THROUGH FRIDAY BEFORE A COLD
FRONT ARRIVES FRIDAY NIGHT INTO SATURDAY TURNING WINDS AROUND TO
THE NORTH.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
836 PM CDT Mon Apr 13 2015
.UPDATE...
ISSUED AT 825 PM CDT MON APR 13 2015
Extensive area of mid and high level cloudiness across central
through southeast Illinois as low pressure tracks well to our
south tonight. Main forecast concern will be how far north the
next batch of rain will push later tonight into Tuesday morning
as the wave passes south of our area. Latest HRRR and Rapid Refresh
models were trending a bit further north with the rain area with
areas along and south of I-70 probably seeing another round of
light rain by Tuesday morning. Will increase the POPs accordingly
over the I-70 counties after midnight. Further north, high pressure
will move across the southern Great Lakes with quite a bit of dry
air advecting south into our region overnight. Cloud cover should
keep temperatures from getting much colder than our current early
morning lows, but our far northern counties, where cloud cover will
be rather thin, may see some upper 30s by morning. Will make the
POP adjustments over our far southeast counties for late tonight
into Tuesday morning. Have already sent out some updated grids for
more cloud cover across the forecast area through Tuesday morning.
Should have the updated ZFP out soon.
&&
.SHORT TERM...(Tonight)
ISSUED AT 243 PM CDT MON APR 13 2015
19z/2pm surface analysis shows cold front departing the far SE KILX
CWA, with showers lingering along and just behind the boundary.
Based on radar timing tools and latest run of the HRRR, it appears
the showers will slip southeast of Lawrenceville by 00z. Will
therefore go with a dry forecast across the board for tonight. Band
of low clouds associated with the showers will exit the area as
well: however, plenty of high clouds will linger well behind the
front. Latest satellite imagery shows this trend quite well, with
thick cirrus seen as far northwest as central Iowa. End result will
be a high/thin overcast for much of the night, with a gradual NW to
SE clearing trend overnight. Low temperatures will range from the
upper 30s northwest of the Illinois River around Galesburg to near
50 degrees far southeast around Lawrenceville.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 243 PM CDT MON APR 13 2015
Main challenges remain with timing of precipitation chances later
this week. Latest GFS has shown a significant shift from its
previous runs in regards to the piece of energy that will be coming
onto the Pacific Northwest coast shortly, trending more toward the
ECMWF/NAM/Canadian solutions of a cutoff low over the central Rockies
by midweek. However, there are still a few differences with the
disposition of this low later in the week. Main storm track will be
along the Canadian border and upper Midwest, resulting in the low
generally meandering northeast. The GFS, which had been very
progressive later this week, is now the slowest and strongest of the
bunch, with the strong low making it as far as Arkansas by early
Sunday, while the ECMWF and Canadian models generally weaken the low
in place over west Texas/east New Mexico. That aspect results in
quite a bit of uncertainty with the PoP`s later in the weekend, but
the general model consensus is for backing down on some of the
chances in the near term.
High pressure drifting across the Midwest will keep the region dry
through much of Wednesday. Current upper low over southeast tip of
New Mexico will be shearing out, with the models bringing the
remnants into the mid-Mississippi Valley late Wednesday/early
Thursday. The ECMWF is most robust with the remaining energy and
thus have a wetter passage, while the GFS/Canadian models are
largely dry and the NAM has only small rain chances. Have focused
the rain chances mainly on Wednesday night and lowered them a bit,
as there will be a persistent east flow which will stifle the column
moistening a good part of the night. Any lingering showers should
exit early Thursday.
Heading into the weekend, most likely time frame for precipitation
would be Friday night, but confidence is still low as mentioned
earlier, and will keep the rain chances at silent 20s for now. The
differences widen by Sunday due to the much stronger GFS, which
provides a blustery/showery solution for us while the ECMWF remains
dry until Sunday evening. Did mention some 25-30% PoP`s for Sunday,
although much lower than the blended initialization would suggest.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 610 PM CDT MON APR 13 2015
VFR conditions are expected through this forecast period. Surface
high pressure will drift in from the west this evening bringing
light winds and a dry air mass to the region. A weather system
south of the Ohio Valley has spread a considerable amount of
cirrus north into our area early this evening and it appears it
will be with us into Tuesday morning. Surface winds will be
northerly tonight at 5 to 10 kts, and northeast at 7 to 12 kts
on Tuesday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...Barnes
LONG TERM...Geelhart
AVIATION...Smith
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1103 PM EDT MON APR 13 2015
.UPDATE...
ISSUED AT 1050 PM EDT MON APR 13 2015
2Z SPC MESOANALYSIS HAS PW VALUES ACROSS THE AREA RANGING FROM
AROUND 1.3 IN FAR SOUTHEASTERN PIKE COUNTY TO NEAR 1.6 INCHES IN
THE FAR SOUTHWEST. THIS PUTS THE WESTERN THIRD OF THE AREA AT
NEARLY 1.5 INCHES IN ADVANCE OF THE SLOW MOVING COLD FRONT.
RAINFALL RATES IN THE SHOWERS ACROSS THE WESTERN HALF OR SO OF THE
AREA HAVE PICKED UP A BIT OVER THE PAST HOUR WITH NEAR 0.02 INCHES
OVER THE PAST HOUR AT JKL. MANY OF THE KY MESONET SITES IN THE
WESTERN THIRD OF THE CWA NOW HAVE TOTALS SO FAR IN THE THIRD OF AN
INCH TO 0.45 INCH RANGE.
THE RECENT NEAR TERM MODEL GUIDANCE CONTINUES TO POINT TO THE
HIGHEST RAINFALL OVERNIGHT AND THROUGH MIDDAY ON TUESDAY GENERALLY
ALONG AND OR WEST OF A LINE FROM NEAR WILLIAMSBURG TO MANCHESTER
TO HAZARD TO INEZ. THERE IS SOME MODEL VARIABILITY FROM RUN TO RUN
OF THE HRRR AND RAP AS FAR AS AMOUNTS. THE 0Z NAM HAS THE HEAVIEST
QPF THROUGH 18Z ON TUESDAY...AND IS PROBABLY OVERDONE AT LEAST
WITH AREAL COVERAGE. HOWEVER...IT POINTS TO LOCALLY HIGHER
AMOUNTS EXCEEDING 3 INCHES NOT BEING OUT OF THE QUESTION.
ATTM...WE HAVE NUDGED THE AXIS OF THE HEAVIEST QPF A TAD FURTHER
TO THE NORTHWEST. OUR CURRENT FORECAST IS CLOSEST TO THE 01Z RAP.
UPDATE ISSUED AT 715 PM EDT MON APR 13 2015
RECENT SHORT TERM MODEL RUNS OF THE HRRR SUGGEST THE AXIS OF
HEAVIEST RAIN TONIGHT MAY BE GENERALLY ALONG AND NORTH OF A LINE
FROM WILLIAMSBURG TO LONDON TO JACKSON TO INEZ. THE 18Z NAM HAS
THE HEAVIEST RAINFALL THROUGH TOMORROW AFTERNOON WITH THE AXIS OF
THE HEAVIEST RAIN FURTHEST NORTHWEST. THE 18Z GFS IF GENERALLY THE
FURTHEST SOUTHEAST. THE HRRR RUNS CONTINUE TO BE IN THE MIDDLE OF
THESE TWO. THE 12Z ECMWF ALSO HAD THE HEAVIEST RAIN TONIGHT INTO
TUESDAY GENERALLY ALONG OR NORTHWEST OF THE LINE PREVIOUSLY
MENTIONED. THE 21Z AND 22Z RAP RUNS ARE A BIT FURTHER SOUTHEAST
COMPARED TO THE HRRR RUNS. ALTHOUGH THERE IS UNCERTAINTY...AT
THIS TIME RANGE...FEEL THE HIGHER RESOLUTION MODELS ARE LIKELY
ONTO A REAL TREND. WITH THIS IN MIND...THE QPF HAS BEEN TRENDED
SLIGHTLY TOWARD THE RECENT HRRR AND RAP RUNS WHICH SHIFTED THE
AXIS OF HEAVIER RAIN A TOUCH FURTHER WEST AND EXTENDED THIS AXIS
INTO NORTHEASTERN KY THROUGH MORGAN AND INTO ELLIOTT COUNTIES.
AS NEW MODEL RUNS ARRIVE...WE WILL CONTINUE TO EVALUATE THE
PLACEMENT OF THE AXIS OF HEAVIEST RAINFALL.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 335 PM EDT MON APR 13 2015
18Z SFC ANALYSIS SHOWS LOW PRESSURE MOVING CLOSER FROM THE
SOUTHWEST WHILE TO THE NORTH A COLD FRONT IS HEADING THIS WAY...AS
SEEN IN THE RADAR MOSAIC AND ON SATELLITE. JUST RECENTLY A FEW
SHOWERS HAVE POPPED UP OVER THE CUMBERLAND VALLEY AND ARE DRIFTING
NORTH NORTHEAST WHILE A MORE SUBSTANTIAL AREA OF RAIN IS LIFTING
NORTH OUT OF NORTHWEST AND NORTH CENTRAL TENNESSEE. FOR MUCH OF
THE DAY...THE CLOUDS STAYED MAINLY IN THE SOUTHERN PARTS OF THE
CWA ALLOWING THE MOSTLY SUNNY NORTH AND EASTERN PORTIONS TO WARM
INTO THE UPPER 70S AND LOWER 80S THIS AFTERNOON...IN CONTRAST TO
LOW AND MID 70S ATTAINED UNDER THE CLOUDS. DEWPOINTS HAVE COME UP
INTO THE LOWER AND MIDDLE 50S IN THE EAST AND NEAR 60 IN THE
WEST...WHILE WINDS HAVE BEEN SOUTH TO SOUTHWEST AT 10 TO 15 MPH.
THE MODELS ARE NOW IN PRETTY GOOD AGREEMENT ALOFT WITH THE
DYNAMIC SPLIT FLOW PATTERN IN PLACE. A DECENT TROUGH WILL MOVE
THROUGH THE GREAT LAKES IN THE NORTHERN STREAM WHILE A BROAD UPPER
LOW WILL SLIDE EAST THROUGH THE SOUTHERN PLAINS. PLENTY OF ENERGY
WILL SPREAD OVER KENTUCKY FROM THESE TWO SYSTEMS WITH THE SOUTHERN
STREAM ONE THE PRIMARY DRIVER FOR WEATHER THROUGH THE SHORT TERM.
THE NORTHERN TROUGH MOVES EAST BY TUESDAY MORNING AND A WELL
DEFINED MCV CROSSES FROM TENNESSEE INTO KENTUCKY THROUGH THE DAY
ACCOMPANIED BY SOME HEIGHT FALLS AND UPPER LEVEL DIVERGENCE. THE
BULK OF THE MID LEVEL ENERGY WILL LIFT NORTH OF THE STATE TUESDAY
NIGHT WHILE RIDGING HOLDS ON OVER THE SOUTHEAST. GIVEN THE MODEL
AGREEMENT HAVE GONE WITH A MODEL BLEND FOR THE WEATHER DETAILS...
WHILE ALSO LEANING HEAVILY ON THE HIGHER RESOLUTION NAM12 AND HRRR
GIVEN THE SMALL SCALE FEATURES THAT ARE CRITICAL TO THE FORECAST
TONIGHT INTO TUESDAY.
SENSIBLE WEATHER WILL FEATURE A RAPID INCREASE IN THE COVERAGE OF
SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND INTO THE
EVENING...OVER THE WESTERN PARTS OF THE AREA INITIALLY. BY
MIDNIGHT...THOUGH...EXPECT SHOWERS AND THUNDERSTORMS TO COVER MOST
OF THE CWA WITH AREAS OF TRAINING LIKELY SETTING UP. VERY HIGH PW
AIR WILL MOVE OVER EAST KENTUCKY TONIGHT IN CONJUNCTION WITH THE
APPROACH OF THE MCV AND COLD FRONT ADDING TO A THREAT OF EXCESSIVE
RAINS. FLASH FLOODING WILL BE POSSIBILITY FROM THIS...BUT GIVEN
THE DURATION OF THE RAINS...EXPECTED TO LAST INTO AT LEAST MIDDAY
TUESDAY...HAVE DECIDED TO GO WITH A BROADER FLOOD WATCH. THE
FRONT PRESSES FURTHER SOUTH AND THE SFC WAVE MOVES ON OUT OF THE
AREA TUESDAY AFTERNOON LEAVING BEHIND SOME LINGERING...LIGHTER...
SHOWERS ALONG WITH SIGNIFICANTLY COOLER TEMPERATURES THAN TODAY.
THE FRONT TO THE SOUTH WILL THEN START TO WORK BACK NORTH TUESDAY
NIGHT WITH INCREASING CHANCES OF SHOWERS BY DAWN WEDNESDAY.
USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS
THROUGH THE NEXT 18 TO 24 HOURS WITH THE SUPERBLEND POPULATED FOR
THESE GRIDS THEREAFTER. DID MAKE SOME MINOR...TERRAIN BASED...
ADJUSTMENTS FOR TEMPERATURES EACH NIGHT. AS FOR POPS WENT WITH THE
HIGHER MAV MOS TONIGHT AND THEN A BLEND THROUGH THE REMAINDER OF
THE SHORT TERM PORTION OF THE FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 335 PM EDT MON APR 13 2015
LONG TERM PORTION OF THE FORECAST PRESENTS AN ACTIVE PATTERN
ACROSS EASTERN KENTUCKY. CLOSED LOW WILL ESTABLISH ITSELF MUCH OF
THE PERIOD BETWEEN THE SOUTHERN PLAINS TO THE FOUR CORNERS. THIS
WILL RESULT IN SEVERAL WAVES RIDING ALONG THE FLOW FROM SW TO NW.
THESE SUBTLE WAVES WILL PRESENT CHANCES OF SHOWERS AND SOME
THUNDERSTORMS THROUGH THE MUCH OF LONG TERM PERIOD. THIS PATTERN
DOES LOOK TO BREAKDOWN BASED OF THE GFS AS WE MOVE TOWARD THE END
OF THE WEEK INTO THE WEEKEND...AS A UPPER LEVEL LONG WAVE
TROUGH/CLOSED LOW PROGRESSES EAST OUT OF THE WESTERN US DEPENDING
ON WHICH RUN YOU LOOK AT. THIS HOWEVER...IS NOT SUPPORTED BY ALL
THE LONG RANGE GUIDANCE SUCH AS THE 00Z ECMWF...00Z GEM...00Z GFS
ENSEMBLE MEAN SOLUTIONS AT THIS POINT. THESE MODELS KEEP THE
CLOSED LOW ACROSS THE WESTERN US UNTIL WE MOVE INTO EARLY NEXT
WEEK. SHOULD BE SAID THAT BOTH SETUPS WOULD KEEP THE CHANCES OF
SHOWERS AND POSSIBLY THUNDERSTORMS IN THE FORECAST FROM TIME TO
TIME THROUGH MUCH OF THE PERIOD. THE REAL QUESTION IS HOW HIGH
WILL THE CHANCES BE ON A GIVEN DAY...THEREFORE RIGHT NOW WILL LEAN
CLOSE TO THE BLENDED GUIDANCE GIVEN THE UNCERTAINTY THAT EXISTS
WITH THE OVERALL PATTERN LATE IN THE LONG TERM PERIOD. THIS COULD
ALSO HAVE IMPLICATIONS ON TEMPERATURES ESPECIALLY TOWARD THE END
OF THE LONG TERM DEPENDING ON THE PROGRESSION OF THE UPPER LEVEL
PATTERN AND POTENTIAL FOR A COLD FRONT SWINGING THROUGH. AGAIN
THINK IT WILL BE BEST TO STAY CLOSER TO THE BLEND GIVEN THE MORE
UNCERTAIN PATTERN ALOFT. AFTER RELATIVELY COOLER...NEAR TO
SLIGHTLY BELOW NORMAL TEMPS FOR WEDNESDAY AND THURSDAY TEMPS FOR
MUCH OF THE PERIOD WILL BE IN THE LOWER 70S FOR MUCH OF EASTERN
KENTUCKY FOR HIGHS REMAINDER OF LONG TERM.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 735 PM EDT MON APR 13 2015
A COLD FRONT AND ASSOCIATED CONVECTION WILL CONTINUE TO APPROACH
THE AREA THIS EVENING. ADDITIONAL CONVECTION IS EXPECTED TO
DEVELOP AND BECOME MORE WIDESPREAD ACROSS THE REGION ESPECIALLY
BY 3Z AND AFTER..WITH CEILINGS GRADUALLY LOWERING. THE CONVECTION
AND LOWERING CIGS SHOULD AFFECT LOZ...SME AND SYM FIRST...BEFORE
GRADUALLY SPREADING TO JKL AND SJS. VFR CONDITIONS WILL DROP DOWN
TO MVFR GENERALLY BETWEEN 0Z AND 6Z AT SME...LOZ AND SYM...AND
AROUND 6Z OR LATER AT JKL AND SJS. CEILINGS WILL LIKELY DROP DOWN
TO IFR BEHIND THE FRONT BETWEEN 05 AND 09Z AND LOOK TO LAST
THROUGH ABOUT 18Z FOR ALL BUT PERHAPS SYM. GENERALLY SOUTH TO
SOUTHWEST WINDS OF 5 TO 10 KT WILL CONTINUE...UNTIL SHIFTING TO
THE NORTH AND NORTHEAST BEHIND THE FRONT OVERNIGHT. NORTH TO
NORTHEAST WINDS SHOULD PERSIST DURING THE DAY ON TUESDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH TUESDAY MORNING FOR KYZ044-050>052-058>060-
068-069-079-083.
FLOOD WATCH THROUGH TUESDAY AFTERNOON FOR KYZ080-084>088-104-
106>120.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
736 PM EDT MON APR 13 2015
.UPDATE...
ISSUED AT 715 PM EDT MON APR 13 2015
RECENT SHORT TERM MODEL RUNS OF THE HRRR SUGGEST THE AXIS OF
HEAVIEST RAIN TONIGHT MAY BE GENERALLY ALONG AND NORTH OF A LINE
FROM WILLIAMSBURG TO LONDON TO JACKSON TO INEZ. THE 18Z NAM HAS
THE HEAVIEST RAINFALL THROUGH TOMORROW AFTERNOON WITH THE AXIS OF
THE HEAVIEST RAIN FURTHEST NORTHWEST. THE 18Z GFS IF GENERALLY THE
FURTHEST SOUTHEAST. THE HRRR RUNS CONTINUE TO BE IN THE MIDDLE OF
THESE TWO. THE 12Z ECMWF ALSO HAD THE HEAVIEST RAIN TONIGHT INTO
TUESDAY GENERALLY ALONG OR NORTHWEST OF THE LINE PREVIOUSLY
MENTIONED. THE 21Z AND 22Z RAP RUNS ARE A BIT FURTHER SOUTHEAST
COMPARED TO THE HRRR RUNS. ALTHOUGH THERE IS UNCERTAINTY...AT
THIS TIME RANGE...FEEL THE HIGHER RESOLUTION MODELS ARE LIKELY
ONTO A REAL TREND. WITH THIS IN MIND...THE QPF HAS BEEN TRENDED
SLIGHTLY TOWARD THE RECENT HRRR AND RAP RUNS WHICH SHIFTED THE
AXIS OF HEAVIER RAIN A TOUCH FURTHER WEST AND EXTENDED THIS AXIS
INTO NORTHEASTERN KY THROUGH MORGAN AND INTO ELLIOTT COUNTIES.
AS NEW MODEL RUNS ARRIVE...WE WILL CONTINUE TO EVALUATE THE
PLACEMENT OF THE AXIS OF HEAVIEST RAINFALL.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 335 PM EDT MON APR 13 2015
18Z SFC ANALYSIS SHOWS LOW PRESSURE MOVING CLOSER FROM THE
SOUTHWEST WHILE TO THE NORTH A COLD FRONT IS HEADING THIS WAY...AS
SEEN IN THE RADAR MOSAIC AND ON SATELLITE. JUST RECENTLY A FEW
SHOWERS HAVE POPPED UP OVER THE CUMBERLAND VALLEY AND ARE DRIFTING
NORTH NORTHEAST WHILE A MORE SUBSTANTIAL AREA OF RAIN IS LIFTING
NORTH OUT OF NORTHWEST AND NORTH CENTRAL TENNESSEE. FOR MUCH OF
THE DAY...THE CLOUDS STAYED MAINLY IN THE SOUTHERN PARTS OF THE
CWA ALLOWING THE MOSTLY SUNNY NORTH AND EASTERN PORTIONS TO WARM
INTO THE UPPER 70S AND LOWER 80S THIS AFTERNOON...IN CONTRAST TO
LOW AND MID 70S ATTAINED UNDER THE CLOUDS. DEWPOINTS HAVE COME UP
INTO THE LOWER AND MIDDLE 50S IN THE EAST AND NEAR 60 IN THE
WEST...WHILE WINDS HAVE BEEN SOUTH TO SOUTHWEST AT 10 TO 15 MPH.
THE MODELS ARE NOW IN PRETTY GOOD AGREEMENT ALOFT WITH THE
DYNAMIC SPLIT FLOW PATTERN IN PLACE. A DECENT TROUGH WILL MOVE
THROUGH THE GREAT LAKES IN THE NORTHERN STREAM WHILE A BROAD UPPER
LOW WILL SLIDE EAST THROUGH THE SOUTHERN PLAINS. PLENTY OF ENERGY
WILL SPREAD OVER KENTUCKY FROM THESE TWO SYSTEMS WITH THE SOUTHERN
STREAM ONE THE PRIMARY DRIVER FOR WEATHER THROUGH THE SHORT TERM.
THE NORTHERN TROUGH MOVES EAST BY TUESDAY MORNING AND A WELL
DEFINED MCV CROSSES FROM TENNESSEE INTO KENTUCKY THROUGH THE DAY
ACCOMPANIED BY SOME HEIGHT FALLS AND UPPER LEVEL DIVERGENCE. THE
BULK OF THE MID LEVEL ENERGY WILL LIFT NORTH OF THE STATE TUESDAY
NIGHT WHILE RIDGING HOLDS ON OVER THE SOUTHEAST. GIVEN THE MODEL
AGREEMENT HAVE GONE WITH A MODEL BLEND FOR THE WEATHER DETAILS...
WHILE ALSO LEANING HEAVILY ON THE HIGHER RESOLUTION NAM12 AND HRRR
GIVEN THE SMALL SCALE FEATURES THAT ARE CRITICAL TO THE FORECAST
TONIGHT INTO TUESDAY.
SENSIBLE WEATHER WILL FEATURE A RAPID INCREASE IN THE COVERAGE OF
SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND INTO THE
EVENING...OVER THE WESTERN PARTS OF THE AREA INITIALLY. BY
MIDNIGHT...THOUGH...EXPECT SHOWERS AND THUNDERSTORMS TO COVER MOST
OF THE CWA WITH AREAS OF TRAINING LIKELY SETTING UP. VERY HIGH PW
AIR WILL MOVE OVER EAST KENTUCKY TONIGHT IN CONJUNCTION WITH THE
APPROACH OF THE MCV AND COLD FRONT ADDING TO A THREAT OF EXCESSIVE
RAINS. FLASH FLOODING WILL BE POSSIBILITY FROM THIS...BUT GIVEN
THE DURATION OF THE RAINS...EXPECTED TO LAST INTO AT LEAST MIDDAY
TUESDAY...HAVE DECIDED TO GO WITH A BROADER FLOOD WATCH. THE
FRONT PRESSES FURTHER SOUTH AND THE SFC WAVE MOVES ON OUT OF THE
AREA TUESDAY AFTERNOON LEAVING BEHIND SOME LINGERING...LIGHTER...
SHOWERS ALONG WITH SIGNIFICANTLY COOLER TEMPERATURES THAN TODAY.
THE FRONT TO THE SOUTH WILL THEN START TO WORK BACK NORTH TUESDAY
NIGHT WITH INCREASING CHANCES OF SHOWERS BY DAWN WEDNESDAY.
USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS
THROUGH THE NEXT 18 TO 24 HOURS WITH THE SUPERBLEND POPULATED FOR
THESE GRIDS THEREAFTER. DID MAKE SOME MINOR...TERRAIN BASED...
ADJUSTMENTS FOR TEMPERATURES EACH NIGHT. AS FOR POPS WENT WITH THE
HIGHER MAV MOS TONIGHT AND THEN A BLEND THROUGH THE REMAINDER OF
THE SHORT TERM PORTION OF THE FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 335 PM EDT MON APR 13 2015
LONG TERM PORTION OF THE FORECAST PRESENTS AN ACTIVE PATTERN
ACROSS EASTERN KENTUCKY. CLOSED LOW WILL ESTABLISH ITSELF MUCH OF
THE PERIOD BETWEEN THE SOUTHERN PLAINS TO THE FOUR CORNERS. THIS
WILL RESULT IN SEVERAL WAVES RIDING ALONG THE FLOW FROM SW TO NW.
THESE SUBTLE WAVES WILL PRESENT CHANCES OF SHOWERS AND SOME
THUNDERSTORMS THROUGH THE MUCH OF LONG TERM PERIOD. THIS PATTERN
DOES LOOK TO BREAKDOWN BASED OF THE GFS AS WE MOVE TOWARD THE END
OF THE WEEK INTO THE WEEKEND...AS A UPPER LEVEL LONG WAVE
TROUGH/CLOSED LOW PROGRESSES EAST OUT OF THE WESTERN US DEPENDING
ON WHICH RUN YOU LOOK AT. THIS HOWEVER...IS NOT SUPPORTED BY ALL
THE LONG RANGE GUIDANCE SUCH AS THE 00Z ECMWF...00Z GEM...00Z GFS
ENSEMBLE MEAN SOLUTIONS AT THIS POINT. THESE MODELS KEEP THE
CLOSED LOW ACROSS THE WESTERN US UNTIL WE MOVE INTO EARLY NEXT
WEEK. SHOULD BE SAID THAT BOTH SETUPS WOULD KEEP THE CHANCES OF
SHOWERS AND POSSIBLY THUNDERSTORMS IN THE FORECAST FROM TIME TO
TIME THROUGH MUCH OF THE PERIOD. THE REAL QUESTION IS HOW HIGH
WILL THE CHANCES BE ON A GIVEN DAY...THEREFORE RIGHT NOW WILL LEAN
CLOSE TO THE BLENDED GUIDANCE GIVEN THE UNCERTAINTY THAT EXISTS
WITH THE OVERALL PATTERN LATE IN THE LONG TERM PERIOD. THIS COULD
ALSO HAVE IMPLICATIONS ON TEMPERATURES ESPECIALLY TOWARD THE END
OF THE LONG TERM DEPENDING ON THE PROGRESSION OF THE UPPER LEVEL
PATTERN AND POTENTIAL FOR A COLD FRONT SWINGING THROUGH. AGAIN
THINK IT WILL BE BEST TO STAY CLOSER TO THE BLEND GIVEN THE MORE
UNCERTAIN PATTERN ALOFT. AFTER RELATIVELY COOLER...NEAR TO
SLIGHTLY BELOW NORMAL TEMPS FOR WEDNESDAY AND THURSDAY TEMPS FOR
MUCH OF THE PERIOD WILL BE IN THE LOWER 70S FOR MUCH OF EASTERN
KENTUCKY FOR HIGHS REMAINDER OF LONG TERM.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 735 PM EDT MON APR 13 2015
A COLD FRONT AND ASSOCIATED CONVECTION WILL CONTINUE TO APPROACH
THE AREA THIS EVENING. ADDITIONAL CONVECTION IS EXPECTED TO
DEVELOP AND BECOME MORE WIDESPREAD ACROSS THE REGION ESPECIALLY
BY 3Z AND AFTER..WITH CEILINGS GRADUALLY LOWERING. THE CONVECTION
AND LOWERING CIGS SHOULD AFFECT LOZ...SME AND SYM FIRST...BEFORE
GRADUALLY SPREADING TO JKL AND SJS. VFR CONDITIONS WILL DROP DOWN
TO MVFR GENERALLY BETWEEN 0Z AND 6Z AT SME...LOZ AND SYM...AND
AROUND 6Z OR LATER AT JKL AND SJS. CEILINGS WILL LIKELY DROP DOWN
TO IFR BEHIND THE FRONT BETWEEN 05 AND 09Z AND LOOK TO LAST
THROUGH ABOUT 18Z FOR ALL BUT PERHAPS SYM. GENERALLY SOUTH TO
SOUTHWEST WINDS OF 5 TO 10 KT WILL CONTINUE...UNTIL SHIFTING TO
THE NORTH AND NORTHEAST BEHIND THE FRONT OVERNIGHT. NORTH TO
NORTHEAST WINDS SHOULD PERSIST DURING THE DAY ON TUESDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH TUESDAY MORNING FOR KYZ044-050>052-058>060-
068-069-079-083.
FLOOD WATCH FROM 11 PM EDT THIS EVENING THROUGH TUESDAY
AFTERNOON FOR KYZ080-084>088-104-106>120.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS SHREVEPORT LA
101 PM CDT SUN APR 12 2015
.AVIATION...
MVFR CIGS ARE IN PLACE ACROSS MUCH OF THE REGION ATTM...BUT AM
EXPECTING A SLOW IMPROVEMENT TO LOW VFR BY MID-AFTERNOON. A WARM
FRONT HAS SHIFTED N INTO SE OK/SW AR AS OF MIDDAY...WHICH WILL
RESULT IN DEEPENING MOISTURE LEVELS ESPECIALLY AS A SW FLOW ALOFT
PERSISTS AHEAD OF A CLOSED LOW THAT WILL ENTER SE NM/FAR W TX LATE
TONIGHT. A WEAK SHORTWAVE MAY CONTRIBUTE TO SCT SHRA DEVELOPING
LATE THIS AFTERNOON THROUGH THIS EVENING AS THIS DISTURBANCE
SHIFTS NE ACROSS THE AREA. CONFIDENCE REMAINS LOW THOUGH AND THUS
HAVE MENTIONED VCSH WITH SOME TEMPO SHRA WITH REDUCED CIGS/VSBYS.
CIGS SHOULD BECOME MVFR THIS EVENING...WITH IFR CIGS EXPECTED TO
DEVELOP BY/AFTER 06Z. SHOULD START TO SEE AREAS OF SHRA
DEVELOP/SPREAD ENE ACROSS E TX/SE OK BY 12Z MONDAY...QUICKLY
SHIFTING ACROSS THE REMAINDER OF THE AREA THROUGH MID TO LATE
MORNING. SHOULD START TO SEE SOME SLOW IMPROVEMENT TO CIGS ACROSS
E TX/NCNTRL LA JUST AFTER THE END OF THE 18Z TAF PERIOD...AS THE
SHRA DIMINISHES. SSE WINDS 5-10KTS WILL PERSIST THROUGH THE TAF
PERIOD. /15/
&&
.PREV DISCUSSION... /ISSUED 1057 AM CDT SUN APR 12 2015/
DISCUSSION...
CONVECTION OVER SOUTH LA/SE TX...HAS REMAINED SCATTERED AND SLOW
TO PROGRESS NWD TODAY. HAVE LOWERED POPS EVEN MORE FOR THIS
AFTN/EVE...AND EVEN REMOVING POPS FAR NORTH THIS AFTN. ALTHOUGH
DEWPOINTS ACROSS MOST OF AREA HAVE JUMPED A FEW DEGREES IN JUST
THE PAST HOUR. RUC DATA ALSO SUPPORTS MOISTENING IN LOW TO MID
LVLS...BUT DRY ABOVE 500 MB...SUGGESTING SCATTERED
COVERAGE...UNTIL THAT LAYER CONTINUES TO MOISTEN. TEMPS LOOK GOOD
ACROSS AREA SO MADE NO CHANGES THERE. /VII/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 77 66 77 64 / 30 60 60 50
MLU 77 65 78 62 / 40 60 60 50
DEQ 77 64 74 58 / 10 60 60 50
TXK 76 64 75 59 / 20 60 60 50
ELD 76 65 73 59 / 20 60 60 50
TYR 77 66 77 62 / 30 60 60 50
GGG 75 66 78 64 / 30 60 60 50
LFK 78 67 79 65 / 50 70 60 50
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1057 AM CDT SUN APR 12 2015
.DISCUSSION...
CONVECTION OVER SOUTH LA/SE TX...HAS REMAINED SCATTERED AND SLOW
TO PROGRESS NWD TODAY. HAVE LOWERED POPS EVEN MORE FOR THIS
AFTN/EVE...AND EVEN REMOVING POPS FAR NORTH THIS AFTN. ALTHOUGH
DEWPOINTS ACROSS MOST OF AREA HAVE JUMPED A FEW DEGREES IN JUST
THE PAST HOUR. RUC DATA ALSO SUPPORTS MOISTENING IN LOW TO MID
LVLS...BUT DRY ABOVE 500 MB...SUGGESTING SCATTERED
COVERAGE...UNTIL THAT LAYER CONTINUES TO MOISTEN. TEMPS LOOK GOOD
ACROSS AREA SO MADE NO CHANGES THERE./VII/.
&&
.PREV DISCUSSION... /ISSUED 709 AM CDT SUN APR 12 2015/
AVIATION...
FOR THE 12Z TAFS...EXPECT MVFR CIGS TO SPREAD NORTH ACROSS THE
FOUR STATE REGION AS WELL AS SCATTERED SHOWERS AND THUNDERSTORMS.
VISIBILITIES WILL BE LOWER IN AND AROUND THE RAIN...OCCASIONALLY
BETWEEN 2 AND 5 MILES. CONDITIONS WILL GRADUALLY LOWER TO IFR AT
MOST AIRPORTS BY 06Z AS THE RAIN CONTINUES TO SATURATE THE LOWER
LEVELS. SURFACE WIND TODAY EAST TO SOUTHEAST 5 TO 10 KTS BECOMING
MOSTLY SOUTHERLY AFTER 13/00Z. /14/
PREV DISCUSSION... /ISSUED 358 AM CDT SUN APR 12 2015/
DISCUSSION...
SELY FLOW AT THE SFC BEGINNING TO RETURN OVER THE WRN PORTIONS OF
THE REGION THIS MORNING...AS A WARM FRONT BEGINS TO LIFT NWD FROM
THE NRN GULF COAST. MEANWHILE ALOFT...FLOW CONTINUES TO BECOME
INCREASINGLY SWLY AHEAD OF A DEEP CLOSED LOW CURRENTLY CENTERED
OVER NWRN MEXICO. DISTURBANCES IN THE FLOW WILL INTERACT WITH THE
WARM FRONT TODAY AS IT LIFTS NWD...GENERATING SHWRS/TSTMS THAT
WILL SPREAD FROM S TO N. CONVECTION WILL CONTINUE AT LEAST
INTERMITTENTLY THROUGH THE FIRST HALF OF THE WORK WEEK...AS THE
UPPER LOW SLOWLY OPENS AND TRACKS ENEWD. DESPITE WET SOILS...FLASH
FLOODING THREAT LOOKS VERY MARGINAL AND SHOULD BE CONFINED TO
INDIVIDUAL ISOLD OCCURRENCES DUE TO THE FCST SCATTERED NATURE OF
THE DEEPER POCKETS OF CONVECTION. A WIDESPREAD 2-4 INCHES OF
RAINFALL IS EXPECTED THROUGH LATE WEDNESDAY...WITH THE HEAVIEST
AMOUNTS FOR OUR AREA EXPECTED OVER PARTS OF N CENTRAL LA. AS HAS
BEEN MENTIONED IN PREVIOUS DAYS...THE PRIMARY CONCERN WITH THIS
SYSTEM LOOKS TO BE THE POTENTIAL THREAT FOR FLOODING ON AREA LAKES
AND RIVERS.
THE DEPARTURE OF THIS DISTURBANCE WILL BRING A SHORT BREAK FROM
RAINFALL LATE WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING...BUT
AN EVEN DEEPER UPPER LOW WILL SWING INTO NM AND WRN TX DURING
THURSDAY/THURSDAY NIGHT...GENERATING ANOTHER WIDESPREAD ROUND OF
CONVECTION THAT DOESN`T LOOK TO END UNTIL SATURDAY NIGHT AT THE
EARLIEST. AT THIS POINT...MODELS ARE PRETTY DIVERGENT WITH REGARD
TO THE INTENSITY/STATE/SPEED OF THIS SECOND UPPER LOW...SO POPS
WILL CONTINUE TO BE HANDLED CONSERVATIVELY IN THE EXTENDED.
TEMPS THROUGHOUT THE PD LOOK TO HOVER WITHIN A COUPLE OF DEGREES
OF SEASONAL NORMALS...AS NO SIGNIFICANT SUN EXPOSURE OR CHANGE IN
AIRMASS IS EXPECTED. /12/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 77 66 77 64 / 30 60 60 50
MLU 77 65 78 62 / 40 60 60 50
DEQ 77 64 74 58 / 10 60 60 50
TXK 76 64 75 59 / 20 60 60 50
ELD 76 65 73 59 / 20 60 60 50
TYR 77 66 77 62 / 30 60 60 50
GGG 75 66 78 64 / 30 60 60 50
LFK 78 67 79 65 / 50 70 60 50
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
719 PM EDT MON APR 13 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 400 PM EDT MON APR 13 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NW ONTARIO INTO THE WRN GREAT LAKES. STRONG QVECTOR DIV IN THE WAKE
OF A DEPARTING SHRTWV AND DROPPING 600-500 MB TEMPS HAVE RESULTED IN
A NEARLY DRY ADIABATIC PROFILE AND MIXING HEIGHT TO NEAR 15K FT WITH
GUSTY WNW WINDS ACROSS THE CWA. THE HIGH SFC-600MB LAPSE RATES HAVE
SUPPORTED THE DEVELOPMENT OF SOME ISOLD LIGHT SHOWERS SHOWERS OR
SPRINKLES/VIRGA FROM NW WI INTO SRN UPPER MI. DOWNDRAFTS ASSOCIATED
WITH THE LIGHT SHOWERS MAY ENHANCED THE GUSTY WINDS AS WAS OBSERVED
AT EGV WITH GUSTS TO 45 MPH.
TONIGHT...WITH THE LOSS OF DAYTIME HEATING AND A WEAKENING PRES
GRADIENT...THE GUSTY WINDS AND ISOLD PCPN WILL DIMINISH QUICKLY.
HOWEVER...FCST BOUNDARY LAYER WINDS SHOULD BE STILL STRONG ENOUGH TO
PROVIDE SOME MIXING AND KEEP TEMPS FROM DROPPING OFF TOO FAR WITH
MIN READINGS IN THE LOW TO MID 30S.
TUE...CONFLUENT MID/UPPER LEVEL FLOW AND THE SFC RIDGE WILL BUILD
OVER THE REGION BRINGING SUNNY SKIES AND DRY CONDITIONS. MIXING TO
AROUND 5K-6K FT OR 800 MB WILL SUPPORT HIGHS FROM THE UPPER 50S EAST
TO THE MID 60S SOUTH AND WEST. DEWPOINTS DROPPING INTO THE 10F-15F
RANGE WILL RESULT IN RH VALUES AROUND 15 PCT OVER THE CNTRL AND WEST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 353 PM EDT MON APR 13 2015
DRY CONDITIONS WILL CONTINUE FOR TUESDAY NIGHT THROUGH
WEDNESDAY...WITH A RIDGE OF HIGH PRESSURE BUILDING AT AT 500MB AND
LINGERING AT THE SFC. WITH PW VALUES AROUND 0.25IN OR LESS AROUND
DAYBREAK WEDNESDAY OVER THE E THIRD OF UPPER MI...FELT REASONABLE TO
LOWER THE MIN TEMPS FOR THE TRADITIONAL COLD SPOTS WEDNESDAY
MORNING TO RIGHT AROUND 30F.
THE APEX OF THE 500MB RIDGE WILL BE OVERHEAD WEDNESDAY
AFTERNOON...AHEAD OF A BROAD TROUGH NEARING FROM S CENTRAL CANADA.
DRY WEATHER WILL CONTINUE THE HIGHER FIRE WEATHER CONCERNS FOR FAR W
AND FAR S CENTRAL UPPER MI /S OF A LINE FROM IMT TO ISQ/. THIS WILL
BE WHERE RH VALUES IN THE UPPER TEENS COMBINE WITH TEMPS AROUND 15F
ABOVE NORMAL. ON A POSITIVE NOTE...WINDS WILL BE FAIRLY LIGHT S
CENTRAL. LOOKING AT THE FCST SOUNDINGS ANYTHING ABOVE 15KTS WOULD BE
ABOVE 400MB...OR AFTER 21Z CLOSER TO THE SFC. PW VALUES OVER THE E
HALF REMAIN AROUND 0.25IN OR LESS /DRIEST OF THE NAM SOLUTION/. OVER
THE FAR W...CLOSER TO THE NEARING LOW...S WINDS COULD GUSTS NEAR 15-
20KTS DURING THE MID TO LATE AFTERNOON HOURS.
AT THE SFC...LOOK FOR AN AREA OF LOW PRESSURE STRETCHING FROM THE S
SASKATCHEWAN/MANITOBA BORDER DOWN THROUGH E CO EARLY WEDNESDAY
MORNING TO DIVIDE INTO 2 SEPARATE SYSTEMS. THE S LOW WILL SINK INTO
TX WEDNESDAY/WEDNESDAY NIGHT WHILE THE N LOW HEADS NE INTO HUDSON
BAY THURSDAY MORNING. EXPECT THE STEADY STATE SFC RIDGE ACROSS UPPER
MI TO SLOWLY WEAKEN WEDNESDAY NIGHT/THURSDAY AS A RESULT OF THE
NEARING LOW. THE BROAD S CENTRAL CANADIAN TROUGH WILL MOVE OVER THE
UPPER GREAT LAKES FOR THE LATTER HALF OF THE WORK WEEK. THURSDAY
AFTERNOON WILL BRING A COLD FRONT STRETCHING FROM THE S HUDSON BAY
LOW THROUGH N MN. IT TENDS TO WASHOUT A BIT AS IT NEARS THE AREA.
WEDNESDAY NIGHT/THURSDAY MORNING WILL HAVE S-SSW WINDS JUST ABOVE
THE SFC /900-950MB/ OF 30-35KTS. SHOULD HAVE ENOUGH OF AN INVERSION
SET UP TO KEEP THESE WINDS FROM BEING REALIZED...WITH AROUND A 5-
10KT PUFF AT THE SFC.
THE 13/00Z RUN OF THE ECMWF IS MORE AGGRESSIVE/STRONGER WITH THE COLD
FRONT...WITH SIGHT SHOWERS THURSDAY MORNING AND W-NW WINDS SLIDING
IN LATE THURSDAY AFTERNOON/EVENING WITH 850MB TEMPS FALLING TO
AROUND 2C BY 06Z FRIDAY. BY CONTRAST THE 13/12Z GFS STILL HAS S FLOW
AND 850MB TEMPS AROUND 7C...AND REMAINS DRY. EXPECT HIGH CLOUDS
SLOWLY LOWERING THROUGH THE DAY...BUT AM NOT TOO EXCITED ABOUT ANY
CHANCE OF PRECIP IN OUR MAINLY DRY PATTERN. THE DIFFERENCES BETWEEN
THE GFS AND ECMWF CONTINUE TO WIDEN AS WE MOVE THROUGH THE WEEKEND.
THE NEXT FEATURE OF INTEREST LOOKS TO BE A SHORTWAVE NEARING IN THE
NW FLOW FROM S MANITOBA/NW MN FRIDAY AFTERNOON TO LAKE
SUPERIOR/UPPER MI FRIDAY EVENING. THE GFS IS STRONGER AND DEEPER
WITH THE SYSTEM...WITH A 996MB SFC LOW NEAR JAMES BAY BY 06Z
SATURDAY...AND PUMPS UP ADDITIONAL MOISTURE FROM THE 500MB LOW
EJECTING OUT OF THE SW STATES. THE ECMWF IS HOVERING AROUND
1007MB...TRACKING THE LOW OVER E LAKE SUPERIOR AND SE ONTARIO...AND
IS RUNNING INDEPENDENT OF THE S LOW SPINNING AROUND THE 4 CORNERS
REGION.
WITHOUT A LOT OF FANFARE...THE 13/00Z ECMWF MERGES THIS 4 CORNERS
LOW BACK INTO THE NEXT WAVE SINKING ACROSS MT AND THE PLAINS STATES
ON SUNDAY. THE RESULT WOULD BE PRECIP NEARING AGAIN FOR MONDAY ON E-
SE WINDS AND 850MB TEMPS AROUND 3C. THE 12Z RUN IS A LITTLE SLOWER
AND KEEPS PRECIP OUT OF THE CWA UNTIL MONDAY AFTERNOON W.
THE GFS KEEPS THE N AND S STREAMS A BIT MORE SEPARATED. AT 12Z
SUNDAY SFC LOWS OVER SW ONTARIO AND AR SLOWLY MERGE 12Z MONDAY
ACROSS LAKE HURON. PRECIP LOOKS TO SKIP UPPER MI UNTIL -10C AIR
PUSHES IN FROM THE NW ON MONDAY. SO THE MAIN QUESTION IS...WILL OUR
NEXT CHANCE OF ANY REAL PRECIP BE FRIDAY AFTERNOON/EVENING AS THE
GFS BELIEVES...OR WILL IT HOLD OFF UNTIL EARLY NEXT WEEK LIKE THE
ECMWF. WILL LOOK AT THE ENSEMBLE FCSTS...AND A GENERAL BLEND MAY BE
THE WAY TO GO FOR WEDNESDAY NIGHT THROUGH NEXT MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 719 PM EDT MON APR 13 2015
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD AT ALL
SITES WITH QUIET WEATHER EXPECTED.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EDT MON APR 13 2015
AS THE PRES GRADIENT WEAKENS THIS EVENING...EXPECT THE GUSTY WRLY
WINDS OF 20 TO 30 KNOTS TO FALL BELOW 25 KNOTS. HIGH PRES BUILDING
OVER THE AREA LATE TONIGHT AND TUE WILL KEEP WINDS BLO 20 KNOTS.
WINDS ARE EXPECTED TO REMAIN AT OR BELOW 25 KNOTS THROUGH SATURDAY.
&&
.HYDROLOGY...
ISSUED AT 353 PM EDT MON APR 13 2015
WILL CONTINUE TO MONITOR MELTING SNOW AND RUNOFF FROM THE AVERAGE
0.25IN OF RAIN THAT FELL THIS MORNING. WHILE MOST LOCATIONS HAVE
ONLY PATCHES OF SNOW LEFT...A FEW SPOTS STILL HAVE SIGNIFICANT SNOW
/MOHAWK WITH 17IN AND MUNISING WITH 19IN/. THE FORECAST GETS A BIT
TRICKY FROM WEDNESDAY NIGHT ON...BUT UNTIL THEN NO ADDITIONAL PRECIP
IS EXPECTED.
DAY SHIFT ISSUED A HYDROLOGICAL STATEMENT /RVS/ FOR PRICKETT DAM ON
THE STURGEON RIVER...WHICH WAS AT 7.1FT AT 10AM MONDAY. FLOOD STAGE
IS 8 FT THERE.
ALONG WITH THE SURGEON RIVER OF BARAGA AND HOUGHTON COUNTIES...THE
ESCANABA RIVER WILL ALSO APPROACH BANKFULL STAGE IN SOME SPOTS MID-
WEEK...WHICH MAKES SENSE GIVEN THAT THE HEADWATERS OF THESE RIVER
HAVE THE MOST SNOW. THE MICHIGAMME RIVER ALSO HAS GREATER SNOWPACK
IN THE HEADWATERS REGION OF THE PESHEKEE RIVER...BUT IT SHOULD TAKE
LONGER FOR THAT WATER TO REACH LOWER SECTIONS OF THE RIVER MORE
PRONE TO FLOODING. STILL...NOT SEEING ANYTHING SUGGESTING MORE THAN
ACTION STAGE POSSIBLE ON THE MICHIGAMME RIVER. OVERALL...NOT
EXPECTING SIGNIFICANT FLOODING THROUGH THE WORK WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
426 PM EDT SUN APR 12 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 425 PM EDT SUN APR 12 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH
ADVANCING THROUGH THE WRN PLAINS WITH A DOWNSTREAM RIDGE FROM THE
CENTRAL GREAT LAKES TO HUDSON BAY. AT THE SFC...A FRONT EXTENDED
THROUGH NW MN AND ERN SD FROM A LOW OVER NE MANITOBA. GUSTY SRLY
WINDS TO 30-35 MPH HAVE DEVELOPED ACROSS MN/WI/UPPER MI WITH A TIGHT
PRES GRADIENT BETWEEN THE FRONT AND HIGH PRES OVER THE ERN CONUS.
TONIGHT INTO EARLY MONDAY...AS THE MID LEVEL TROUGH AND SFC FRONT
ADVANCE TOWARD THE WRN LAKES...EXPECT SHRA COVERAGE TO INCREASE
ACROSS ERN MN INTO WRN LAKE SUPERIOR BY LATE THIS EVENING. MODELS
WERE IN BETTER AGREEMENT WITH THE TIMING OF THE SYSTEM AND PCPN
THROUGH THE REGION...REFLECTING THE SLOWING TREND FROM THE LAST
SEVERAL MODEL CYCLES. WITH MODERATE TO STRONG 700-300 QVECTOR CONV
AND 800-600 MB FGEN AHEAD OF THE MID LEVEL TROUGH NMRS SHOWERS ARE
EXPECTED ACROSS UPPER MI...MAINLY FROM WEST TO EAST BETWEEN 06Z-15Z.
ALTHOUGH ONLY MARGINAL ELEVATED INSTABILITY OF A FEW HUNDRED J/KG IS
FCST...A STRONG LOW LEVEL JET OF 40-45 KNOTS BRINGING 850 MB
DEWPOINTS NEAR 8C MAY BE ENOUGH TO SUPPORT SOME ISOLD TSRA.
STRONG QVECTOR DIV AND DRYING IS EXPECTED TO SPREAD THROUGH UPPER MI
DURING THE AFTERNOON. HOWEVER...WITH DROPPING 600-500 MB TEMPS AND
RESULTING NEARLY DRY ADIABATIC PROFILE AND MIXING HEIGHT TO NEAR 15K
FT...GUSTY WINDS ARE EXPECTED TO DEVELOP. THE STRONGEST WRLY WINDS
ARE EXPECTED OVER THE TYPICALLY FAVORED HIGHER TERRAIN OF THE
KEWEENAW WHERE GUSTS TO 40-45 MPH MAY BE POSSIBLE. THE HIGH SFC-
600MB LAPSE RATES WILL SUPPORT THE POTENTIAL FOR SOME LIGHT SHOWERS
OR SPRINKLES/VIRGA DURING PEAK HEATING IN THE AFTERNOON. THE HIGH
MIXING DEPTH SHOULD ALSO DROP DEWPOINTS INTO THE TEENS WITH RH VALUES
TO NEAR 20 PCT.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 307 PM EDT SUN APR 12 2015
MON NIGHT MAY SEE A FEW RAIN SHOWERS LINGERING FROM MON...BUT WITH
THE UPPER TROUGH AND SHORTWAVE E OF THE AREA...SKIES WILL BECOME
MOSTLY CLEAR. THIS WILL ALLOW INTERIOR W TEMPS TO FALL BELOW
FREEZING.
A SFC RIDGE MOVING OVER ON TUE WILL LEAD LIGHT WINDS AND SUNNY
SKIES. SHOULD BE A VERY DRY DAY WITH MIN RH VALUES AS LOW AS THE MID
TEENS INTERIOR W HALF...AND IN AND IN THE 20S ELSEWHERE AWAY FROM
THE IMMEDIATE GREAT LAKES LAKESHORE AREAS. WIND GUSTS WILL BE IN THE
10-15MPH RANGE DURING PEAK HEATING/DRIEST CONDITIONS. HIGH TEMPS
WILL BE COOLEST OVER THE E IN THE 40S TO MID 50S DUE TO NW WINDS OFF
LAKE SUPERIOR AND WARMEST OVER THE INTERIOR WEST HALF IN THE LOW TO
MID 60S.
WED MAY BE A MORE SIGNIFICANT FIRE WEATHER DAY AS INCREASED SLY FLOW
BRINGS WARMER BUT STILL DRY AIR INTO THE REGION WITH GUSTY SLY WINDS
BETWEEN THE EXITING SFC HIGH AND AN APPROACHING SFC TROUGH. HIGHS
WILL BE IN THE MID TO UPPER 60S INTERIOR W TO THE MID 50S E DOWNWIND
OF LAKE MI. SFC GUSTS TO AROUND 20MPH ARE EXPECTED. MIN RH VALUES
WILL BE IN THE UPPER TEENS TO MID 20S OVER MUCH OF THE WEST HALF AND
INTERIOR E HALF...WITH RH VALUES IN THE 30S ALONG LAKE SUPERIOR AND
LAKE MICHIGAN. THIRD DAY IN A ROW OF LOW RH VALUES COMBINED WITH
GUSTY WINDS AND WELL ABOVE NORMAL TEMPS WILL LEAD TO INCREASED FIRE
WEATHER CONCERNS.
A WEAK SFC TROUGH STRETCHED BETWEEN A NRN STREAM SYSTEM MOVING
ACROSS CANADA AND A LOW OVER THE CENTRAL PLAINS WILL SLOWLY TRANSIT
THE AREA ON THU. MOISTURE AND FORCING WILL BOTH BE LIMITED...SO RAIN
CHANCES ARE VERY LOW AND TRENDING LOWER ON THU. TEMPS DO LOOK TO BE
A BIT COOLER WITH HIGHS IN THE 50S TO LOW 60S ON THU AND SFC RH WILL
BE HIGHER.
INCREASED UNCERTAINTY FRI INTO SUN AS MODELS CONTINUE THE IDEA OF
BRINGING A QUICK HITTING SHORTWAVE TO THE REGION FRI NIGHT AND A
DEEP TROUGH TO JUST W OF THE REGION LATE SUN. RAN CONSENSUS BLEND
FOR THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 136 PM EDT SUN APR 12 2015
VFR CONDITIONS WILL CONTINUE AT ALL THE TAF SITES AT LEAST THROUGH
THIS EVENING. LLWS WAS AGAIN AT KSAW TONIGHT AS THE CORE OF STRONGER
SW WINDS MOVES IN ABOVE THE SFC. GUSTY SSW WINDS WITH FAVORABLE
DAYTIME MIXING WILL CONTINUE INTO THIS EVENING FOR ALL SITES. SHRA
MOVING IN ALONG FRONT LATE TONIGHT SHOULD HELP LOWER CIGS DOWN TO
MVFR AT ALL SITES. RECOVERY TO VFR IS EXPECTED BY LATE MON MORNING
WITH DRYING BEHIND THE FRONT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 425 PM EDT SUN APR 12 2015
STRONG SRLY WINDS WILL CONTINUE INTO THIS EVENING. WINDSPEEDS WILL
BE VERY DEPENDENT ON MEASURING HEIGHT GIVEN THE STABLE TEMP PROFILE
AND MARINE LAYER OVER THE LAKE. GALES ARE STILL EXPECTED THROUGH
THIS EVENING OVER THE EAST FOR THE HIGHER PLATFORMS. BEHIND THE
TROUGH...EXPECT W WINDS GENERALLY IN THE 20 TO 30KT WITH SOME GALE
FORCE GUSTS POSSIBLE THROUGH MONDAY. HIGH PRESSURE WILL THEN BRING
WINDS DOWN UNDER 20 KNOTS FOR TUESDAY THROUGH FRIDAY.
&&
.HYDROLOGY...
ISSUED AT 307 PM EDT SUN APR 12 2015
LOW CHANCES FOR SIGNIFICANT RAINFALL AMOUNTS WILL HELP KEEP STREAM
LEVELS IN CHECK AS A SIGNIFICANT AMOUNT OF REMAINING SNOW PACK MELTS
OFF THIS WEEK. ENSEMBLE RIVER GUIDANCE AND RIVER FORECASTS SUGGEST
POTENTIAL FOR THE SURGEON RIVER OF BARAGA AND HOUGHTON COUNTIES AND
ESCANABA RIVER TO APPROACH BANKFULL STAGE IN SOME SPOTS MID-
WEEK...WHICH MAKES SENSE GIVEN THAT THE HEADWATERS OF THESE RIVER
HAVE THE MOST SNOW. THE MICHIGAMME RIVER ALSO HAS GREATER SNOWPACK
IN THE HEADWATERS REGION OF THE PESHEKEE RIVER...BUT IT SHOULD TAKE
LONGER FOR THAT WATER TO REACH LOWER SECTIONS OF THE RIVER MORE
PRONE TO FLOODING. STILL...NOT SEEING ANYTHING SUGGESTING MORE THAN
ACTION STAGE POSSIBLE ON THE MICHIGAMME RIVER. OVERALL...NOT
EXPECTING SIGNIFICANT FLOODING OVER THE NEXT 5-7 DAYS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 2 AM EDT MONDAY FOR LSZ266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
HYDROLOGY...TITUS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
328 PM EDT SUN APR 12 2015
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/HYDRO/MARINE
.SYNOPSIS...
ISSUED AT 305 PM EDT SUN APR 12 2015
HIGH PRESSURE OVER THE CENTRAL APPALACHIANS WILL PUSH EAST TONIGHT
ALLOWING A COLD FRONT TO APPROACH THE GREAT LAKES REGION FROM THE
WEST. AFTER A DRY EVENING...SHOWERS WILL BEGIN TO ARRIVE ACROSS
THE WESTERN GREAT LAKES AREA. THERE COULD EVEN BE A FEW
THUNDERSTORMS FOR SOUTHERN LOCATIONS. THE PRECIPITATION WILL COME
TO A END ON MONDAY. HIGH PRESSURE THEN SETTLES IN FOR THE
MIDDLE PART OF THE WEEK.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 305 PM EDT SUN APR 12 2015
MODELS ARE NOT IN AGREEMENT WITH HOW THE WEATHER WILL UNFOLD FOR
TONIGHT AND MONDAY. HRRR RUC BRINGS SHOWERS IN THIS EVENING AND
THEN SUGGESTS MOST WESTERN LOCATIONS WILL END UP WET LATER
TONIGHT AS CONVECTION TRACKS THROUGH ILLINOIS. NAM...GFS AND HIGH
RES EURO ARE GENERALLY BACKING OFF ON ANY PRECIPITATION
TONIGHT...BUT STILL SUPPORT SHOWERS FOR MONDAY MORNING. WITH SOME
ELEVATED INSTABILITY ARRIVING ACROSS SOUTHWESTERN LOWER MI...THERE
COULD BE A RUMBLE OF THUNDER AS WELL. LIFT IN THE DGZ IS STILL
SHOWN TO BE FAVORABLE FOR MEASURABLE RAIN FROM THE GFS. WILL KEEP
POPS ELEVATED FOR THIS EVENT...BUT CONFIDENCE IS SOMEWHAT LOWER.
SPC WRF WOULD KEEP THE SHOWERS GOING INTO THE AFTERNOON. THIS
TREND WILL NEED TO BE MONITORED.
SUBSIDENCE IN THE DGZ ARRIVES FOR MONDAY NIGHT INTO TUESDAY NIGHT.
THIS WILL ACT TO KEEP THE POSSIBILITY OF ANY PRECIPITATION LOW.
GIVEN THE DRY ATMOSPHERE THAT WILL BE IN PLACE...MON NIGHT AND TUE
NIGHT SHOULD BE COOL. TEMPERATURES WILL MODERATE FOR TUESDAY
DURING THE DAY GIVEN THE STRONG EXPECTED SUNSHINE WITH ABOVE NORMAL
TEMPERATURES LIKELY.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 305 PM EDT SUN APR 12 2015
THE LONG TERM PORTION OF THE FCST WILL FEATURE MILD SPRING WEATHER
ALONG WITH SOME CHCS FOR APRIL SHOWERS. WE EXPECT THAT MOST OF THE
PERIOD WILL REMAIN DRY ASIDE FROM THE WED NIGHT/THU SYSTEM. WE DO
HAVE TO INCLUDE SOME LOW CHCS FOR A FEW SHOWERS FOR A COUPLE OF
OTHER PERIODS.
ONE OF THE BEST DAYS OF THE LONG TERM WILL COME AT THE BEGINNING OF
THE PERIOD ON WED. WE WILL SEE SFC RIDGING MOVE BY TO OUR EAST AND
THE UPPER RIDGE WILL SETTLE OVERHEAD. RETURN FLOW WILL BRING MAX
TEMPS WELL INTO THE 60S ALONG WITH A GOOD DEAL OF SUNSHINE.
THE BEST CHC FOR RAIN WILL COME ON WED NIGHT/THU AS MENTIONED ABOVE.
IT APPEARS THAT WE SHOULD SEE A SHORT WAVE TROUGH LIFT NE OUT OF THE
SW. THIS WAVE WILL HAVE SOME MOISTURE FROM THE GULF OF MEXICO TO
WORK WITH AS IT MOVES TO THE NE.
WE HAVE TRENDED THE FCST DRIER FOR THE THU NIGHT/FRI TIME
FRAME....WITH LEAVING JUST A SLIGHT CHC OF LIGHT RAIN SHOWERS IN.
THE LATEST TRENDS HAVE BEEN FOR THE THU FRONT TO CLEAR THE
AREA...AND THEN THE PROGRESSIVE WRLY FLOW JUST SOUTH OF THE NRN
BRANCH OF THE JET TO SETTLE IN. THIS SETUP COMBINED WITH THE UPPER
LOW CLOSING OFF ACROSS THE DESERT SW WILL KEEP THE AREA IN BETWEEN
THE SPLIT FLOW JET STRUCTURE WITHOUT ANY KIND OF APPRECIABLE
MOISTURE FEED.
WE WILL SEE A LITTLE BIT BETTER CHC OF RAIN COME IN FOR FRI NIGHT AS
A WAVE IN THE NRN STREAM TRIES TO DROP DOWN INTO THE AREA.
CONDITIONS WILL THEN DRY OUT FOR THE MOST PART NEXT WEEKEND. THE FRI
NIGHT SYSTEM WILL REMAIN MAINLY ACROSS NRN MI WITHOUT ANY
SIGNIFICANT MOISTURE ADVECTION INTO THE AREA. THIS SHOULD ZIP BY SAT
MORNING...LEAVING COOLER AND DRY CONDITIONS FOR THE REMAINDER OF THE
PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 140 PM EDT SUN APR 12 2015
OUR MAIN FOCUS OF THE 18Z FCSTS WILL BE THE THREAT OF RAIN SHOWERS
AND ASSOCIATED LOWER CONDITIONS WITH A SYSTEM FROM THIS EVENING
THROUGH THE END OF THE PERIOD.
VFR CONDITIONS RULE THIS AFTERNOON...AND SHOULD RULE THROUGH 00Z
AND LIKELY UNTIL LATE TONIGHT. THAT SAID...WE WILL HAVE SOME MID
CLOUDS COME IN TOWARD 00Z THIS EVENING AND POSSIBLY A FEW
SPRINKLES/LIGHT SHOWERS. THESE ARE NOT EXPECTED TO AMOUNT TO
ANYTHING AND CIGS AND VSBYS SHOULD REMAIN VFR.
A MUCH MORE LIKELY CHC OF RAIN WILL COME VERY LATE TONIGHT ACROSS
THE WEST AND AFTER DAYBREAK TO THE EAST. IT WILL START OUT AS
VFR...BUT WE EXPECT CONDITIONS TO DROP INTO THE MVFR CATEGORY A
COUPLE OF HOURS AFTER THE PCPN STARTS. WE ARE EXPECTING IT TO MOVE
INTO KMKG AROUND 10Z OR SO...AND THEN SPREAD EAST BY 14Z. A FEW
HOURS OF MVFR CAN BE EXPECTED BEFORE RAIN AND CLOUDS CLEAR OUT
TOWARD THE END OF THE PERIOD AND MORE LIKELY BEYOND THIS FCST
PERIOD.
&&
.MARINE...
ISSUED AT 305 PM EDT SUN APR 12 2015
STRENGTHENING SOUTHERLY FLOW WILL SUPPORT SOME WAVES AROUND 4 FEET
LATER TONIGHT INTO MONDAY MORNING NORTH OF HOLLAND. WILL GO WITH A
SMALL CRAFT ADVISORY. HIGH PRESSURE THEN BUILDS IN FOR TUESDAY.
THIS WILL ACT TO LIMIT THE WAVE HEIGHTS.
&&
.HYDROLOGY...
ISSUED AT 305 PM EDT SUN APR 12 2015
RIVERS THAT ARE NOT ALREADY FALLING WILL REACH THEIR CREST WITHIN
THE NEXT DAY. THE ROGUE BELOW ROCKFORD FELL BELOW MINOR FLOOD STAGE
LAST NIGHT SO THE FLOOD WARNING HAS BEEN TRANSITIONED TO AN
ADVISORY. EIGHT RIVERS IN OUR AREA ARE ABOVE BANKFULL AT THIS TIME
AND A FEW WILL FALL BELOW BANKFULL OVER THE NEXT 24 HOURS. ONE TO
TWO TENTHS OF AN INCH OF RAINFALL IS EXPECTED THROUGH MONDAY
MORNING... AND THIS SHOULD HAVE VERY LITTLE TO NO NOTICEABLE IMPACT
ON RIVER LEVELS. A SIGNIFICANT RAINFALL EVENT IS NOT EXPECTED THIS
WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM 2 AM TO 4 PM EDT MONDAY FOR LMZ846>849.
&&
$$
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...NJJ
AVIATION...NJJ
HYDROLOGY...CAS
MARINE...MJS
AREA FORECAST DISCUSSION...UPDATE
NWS JACKSON MS
1015 PM CDT MON APR 13 2015
.UPDATE... A MID LEVEL CONVECTIVE REMNANT (MCV) PUSHING ACROSS THE
REGION THIS EVENING HAS PRODUCED SCATTERED TO NUMEROUS SHOWERS (AND
AN OCCASIONAL ISOLATED RUMBLE OF THUNDER) MAINLY ALONG AND NORTH OF
THE I-20 CORRIDOR IN CENTRAL MS. 00Z JAN SOUNDING REVEALS VERY LOW
LCLS/LFCS...NEARLY 1000 J/KG ML CAPE...AND HODOGRAPHS SUGGESTIVE OF
LOW LEVEL WIND SHEAR CAPABLE OF GENERATING STORM ROTATION. DESPITE
EXTREMELY FEW TRUE STORMS (AS MENTIONED) THERE HAVE BEEN SOME
SPORADIC REPORTS OF GENERALLY MINOR DAMAGE. IT IS POSSIBLE WE COULD
HAVE HAD ONE OR TWO WEAK TORNADO TOUCHDOWNS IN THE REGION BUT IT
WILL HAVE TO WAIT UNTIL AFTER DAYBREAK TOMORROW TO WORK ON DOING ANY
CONFIRMATION OF THIS.
FOR THE REMAINDER OF TONIGHT EXPECT THE RASH OF GLORIFIED SHOWERS TO
CLEAR EAST OF THE GOLDEN TRIANGLE REGION IN A FEW HOURS AS THE
ASSOCIATED MCV MOVES WELL AWAY FROM THE REGION. A WEAK COLD FRONT
WILL DROP INTO THE ARKLAMISS DELTA AND STALL BY DAYBREAK...PERHAPS
KICKING OFF A FEW MORE SHOWERS AND MAYBE EVEN AN ISOLATED STORM UP
THERE. LATEST HRRR RUNS SUGGEST ELSEWHERE SOME SHOWERS AND STORMS
COULD START BREAKING OUT IN MAINLY SOUTHWESTERN ZONES BY
DAYBREAK...BUT FOR MOST LOCATIONS A DRY REST OF THE NIGHT IS MOST
LIKELY. ALSO WORTH MENTIONING IS THE POTENTIAL FOR PATCHY DENSE FOG
GIVEN THE SATURATED STATE OF THE GROUND AND SOME TRANSIENT PROSPECT
OF RADIATIONAL COOLING IN BETWEEN LOWER CLOUD LAYERS. THIS WILL BE
MENTIONED IN THE HWO. /BB/
&&
.AVIATION...WIDESPREAD IFR TO MVFR FLIGHT CATS DUE TO COMBINATION OF
LOW CLOUDS AND FOG ARE EXPECTED TO DEVELOP ACROSS THE REGION LATE
TONIGHT AND LASTING THROUGH 9 OR 10 AM TOMORROW MORNING. THEREAFTER
FLIGHT CATS SHOULD IMPROVE TO A MIX OF VFR/MVFR (WITH MAINLY JUST
CEILINGS RESTRICTIONS) THROUGH EARLY AFTERNOON. WINDS WILL BE A
LITTLE ERRATIC CONSIDERING A BOUNDARY WILL BE DROPPING INTO THE
REGION AND STALLING...BUT ANTICIPATED NO WINDS WILL BE OVERLY
STRONG. CONDITIONS WILL BE MOSTLY DRY LATE TONIGHT BUT ANTICIPATE
SHOWERS AND STORMS TO BUILD BY MIDDAY TO EARLY AFTERNOON TOMORROW.
/BB/
&&
.PREV DISCUSSION... /ISSUED 355 PM CDT MON APR 13 2015/
DISCUSSION...TONIGHT THROUGH TUESDAY NIGHT...SHOWERS AND STORMS...
ASSOCIATED WITH A DISTURBANCE ALOFT AND AN ATTENDANT MCV...WHOSE
CENTER IS JUST CROSSING THE MISSISSIPPI RIVER INTO WEST CENTRAL
MISSISSIPPI...CONTINUES TO LIFT EAST NORTHEAST ACROSS THE CWA THIS
AFTERNOON. ALL OF THIS ACTIVITY IS ASSOCIATED WITH AN UPPER LEVEL
LOW PRESSURE SYSTEM CHURNING OVER NORTHWEST TEXAS. AS THE MCV
CONTINUES TO LIFT EAST NORTHEAST...SHOWERS...ALONG WITH A FEW
THUNDERSTORMS...ASSOCIATED WITH IT WILL SHIFT NORTHEAST ACROSS THE
AREA. POCKETS OF HEAVY DOWNPOURS ARE POSSIBLE WITH THIS CONVECTION
THIS AFTERNOON AND INTO THE EVENING...WHICH COULD RESULT IN SOME
LOCALIZED FLASH FLOODING. CURRENTLY FOR THIS AFTERNOON AND
EVENING...IT LOOKS LIKE THIS POTENTIAL WILL EXIST OVER AREAS ALONG
AND NORTH OF THE INTERSTATE 20 CORRIDOR WHERE ACTIVITY IS EITHER
FALLING OR ADVANCING INTO.
COMPUTER MODELS INDICATE ONCE THIS ONGOING ACTIVITY ACROSS THE CWA
CLEARS OUT...THERE WILL BE A LULL IN ORGANIZED ACTIVITY DURING THE
OVERNIGHT HOURS. STILL WITH THIS DEEPLY MOIST AIRMASS OVER THE
REGION...AND SUBTLE POCKETS OF ENERGY MEANDERING ABOUT...SOME
SHOWERS CAN`T BE RULED OUT THROUGH THE NIGHT. I ALSO WON`T RULE OUT
THE POTENTIAL FOR SOME HEAVY DOWN POURS WITH SHOWER ACTIVITY
OVERNIGHT AS PRECIPITABLE H2O VALUES GENERALLY HOVER BETWEEN 1.75-
2.00 INCHES.
ANOTHER BOUT OF SHOWERS AND STORMS WILL BE POSSIBLE TUESDAY INTO
TUESDAY EVENING AS YET ANOTHER DISTURBANCE IS PROGGED TO SHIFT EAST
NORTHEAST NEAR THE FORECAST AREA...WHILE A COLD FRONT TRIES TO SINK
SOUTHEAST INTO AT LEAST THE NORTHWEST PORTION OF THE CWA. THERE
STILL REMAINS SOME QUESTION TO WHETHER OR NOT THIS FEATURE WILL MAKE
IT THIS FAR SOUTH. STILL FOR THE REASONS JUST STATED ABOVE...IN
ADDITION TO DAYTIME HEATING IN THIS MOIST AND UNSTABLE AIRMASS...
SOLID RAIN CHANCES WILL EXIST ACROSS THE FORECAST AREA TUESDAY.
SOME RAIN CHANCES WILL LINGER INTO TUESDAY NIGHT...BUT AGAIN AN
OVERALL LULL IN ACTIVITY IS CURRENTLY FORECAST FOR THE TUESDAY NIGHT
PERIOD. /19/
WEDNESDAY THROUGH SUNDAY NIGHT...THE LONG TERM WILL BE
DOMINATED BY SOUTHWEST FLOW...ABUNDANT MOISTURE AND A SERIES OF
SHORT WAVES MOVING ACROSS THE AREA. ON WEDNESDAY ANOTHER SHORT WAVE
WILL MOVE ACROSS THE AREA WITH ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS. THE GFS ACTUALLY INDICATES A BREAK IN THE ACTIVITY
WEDNESDAY NIGHT INTO THURSDAY AS SHORT WAVE RIDGING MOVES ACROSS THE
AREA WITH RELATIVELY DRIER AIR BUILDING IN...BUT THIS WILL BE SHORT
LIVED AS PWATS INCREASE TO ABOVE 1.7 INCHES THURSDAY AFTERNOON AND
ANOTHER SHORT WAVE MOVES ACROSS THE AREA.
BOTH THE GFS/ECMWF ARE IN GOOD AGREEMENT OF AN UPPER LOW CUTTING
GENERALLY OVER THE FOUR CORNERS REGION IN THE SOUTHWEST CONUS WITH
SOUTHWEST FLOW CONTINUING TO PREVAIL ACROSS THE REGION INTO THE
WEEKEND. THE GLOBAL MODELS VERY ON THE TIMING OF THE SHORT WAVES
ACROSS THE AREA THURSDAY INTO SATURDAY...BUT THERE WILL CONTINUE TO
BE A RISK FOR HEAVY RAINFALL AND FLASH FLOODING. BOTH THE GFS/ECMWF
PHASE THE UPPER LOW WITH AN UPPER TROUGH AND BRINGS THIS SYSTEM
ACROSS THE AREA DURING THE SATURDAY NIGHT/SUNDAY TIME FRAME. THE
GLOBAL MODELS DO AGREE ON ONE THING IS THAT IT WILL BE VERY WET FOR
THE NEXT WEEK OR SO ACROSS THE ARKLAMISS. /15/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 67 77 63 78 / 21 67 49 61
MERIDIAN 66 78 63 78 / 34 65 59 65
VICKSBURG 65 76 63 79 / 23 63 47 58
HATTIESBURG 67 78 65 79 / 27 70 52 64
NATCHEZ 66 77 63 78 / 36 68 41 57
GREENVILLE 62 72 60 76 / 20 48 42 52
GREENWOOD 64 74 62 77 / 21 48 51 58
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BB/15/19
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
415 PM CDT Sun Apr 12 2015
.DISCUSSION...
Issued at 415 PM CDT SUN APR 12 2015
Tonight:
Morning convective system certainly stabilized an already stable
boundary layer. Airmass has been slow to recover with considerable
cloud cover overspreading the region. However, still expect a line
of convection to roll through tonight, just arriving a bit later.
Attention is turned to the west as a shortwave trough rolls into the
Northern and Central High Plains. HRRR and NAM generate scattered
convection along the NE portion of the cold front. Current visible
satellite imagery indicates cumulus along the front is becoming
agitated so expect to see convection form soon. Activity then
expected to roll eastward. Modest MLCAPEs from 1000-1500J/kg and
30kt 0-6km shear should support some strong/possibly severe storms
to our west by the time the convection moves into our CWA after 03Z
the instability should have waned and convection weakened. A few
storms could produce some sub-severe hail and gusty winds believe
the main concern revolves around locally heavy rainfall. Some areas
could pick up over an inch of rain as the line of storms move
through. All of the precipitation should have exited the eastern CWA
by 12z Monday.
Monday - Tuesday:
Fairly quiet period marked by weak surface high pressure moving in
the wake of the departed cold front. Weak return flow on Tuesday
with little day-to-day temperature change with slightly above
average readings. No discernible affect on sensible weather other
than increasing clouds.
Wednesday/Wednesday night:
The current closed upper low now over northern Mexico is expected to
weaken as it lifts north-northeast through the Central Plains and
CWA. While there should be decent moisture lifted northward with
this feature minimal instability will limit amount of thunder. Given
that the operational models have been generating a similar solution
believe 30-40 PoPs are warranted for scattered convection.
Thursday - Sunday:
Roll of the dice as to how weather will evolve from Thursday through
Sunday. Not especially fond of the blended model approach of carpet
bombing chance PoPs in every period. The medium range models drop a
deep upper trough into the Desert Southwest and then cut it off.
Models typically are challenged significantly with these features
initially. They tend to lift them out too soon and too far east. Will
be interesting to see how this system is handled going forward.
Difficult trying to time any weak impulse ejected from this system
within the downstream southwesterly flow. For now will handle this
with low chance PoPs with above average temperatures.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 1220 PM CDT SUN APR 12 2015
Will see VFR conditions initially with thinning cloud cover during
the afternoon hours. Southerly winds will remain steady, gusting to
20 kts at times prior to sunset. A cold front will push through the
area overnight, bringing with it the next chance for precipitation
and thunderstorm activity. Ceiling heights will gradually lower in
advance of the frontal boundary. Isolated thunderstorms will begin to
develop around 05Z with more prevailing activity commencing shortly
thereafter. Ceilings should remain VFR during this development,
though visibilities will diminish at times coincident with the heavier
precipitation. A dry air mass in the wake of the cold front will move
in Monday morning with lifting cloud cover through the morning and
afternoon.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...Welsh
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
124 PM CDT Sun Apr 12 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 410 AM CDT Sun Apr 12 2015
Activity over eastern KS/western MO is making very slow progress to
the east northeast as it hits the "wall" of drier air over region.
However, models continue to spread higher dewpts into western MO
this morning on nose of low level jet. This in conjunction with a
decent shortwave over central KS, a more substantial area of storms
have developed and the 05z HRRR tracks this complex east northeast
towards forecast area over the next several hours. Scattered showers
and some elevated convection to move through central and northeast
MO, west central IL through midday before diminishing. Otherwise,
main issue for today will be the temperatures. Will see decent cloud
cover today, so will trend towards the cooler guidance and kept
highs in the upper 60s far north to the mid 70s far south, where the
cloud cover may be thinner.
Byrd
.LONG TERM: (Tonight through Saturday)
Issued at 410 AM CDT Sun Apr 12 2015
Primary forecast concerns for tonight and into Monday remain focused
on how to handle the precipitation threat during this time period.
All of the 00z synoptic solutions...as well as the latest available
hi-res output...are continuing earlier trends depicting an
agonizingly slow southeast push of the showers and thunderstorms
overnight tonight. Initially the delay seems to be the result of
the residually dry low level air, but once the moisture does arrive
most of the lift is primarily focused over northwest sections of the
CWA...due to shortwave energy and (by late tonight) forcing along
cold front. Given the good agreement in the solutions I`ve tried to
"think" slow with the progression of PoPs into our southeast
counties, but over NW sections of the FA forecast will push PoPs
into the categorical range by late tonight due the plentiful
moisture in this area as well as the aforementioned lifting
mechanisms, and low level jet advecting unstable air into this area.
Can`t totally rule out a threat of some hail with the overnight
storms, but with the best instability remaining over the Plains the
Day 1 SWO depiction that keeps the primary severe weather threat
west of our CWA looks good.
Precipitation chances will be pushing southeast on Monday with the
cold front, and by afternoon it would appear the only rain threat
left in our CWA will be confined to our far southeast counties.
Placement of PoPs during the morning a bit of a question mark as
there is some uncertainly on how fast the band of showers and storms
over northwest sections of the CWA will wind down during the predawn
hours, but for now will stay fairly close to going trends which has
the northern edge of the morning rain near a KPPQ-KJEF line.
With cold front dropping south of the FA, and with surface ridge
pushing into the region in the front`s wake, dry forecast still
looks good for Monday night and into Tuesday. However, threat of
wet weather will return Tuesday night and Wednesday as remnants of
upper low meanders north-northeast from the southern Plains. For
now, have maintained chance PoPs with this system.
Overall, no big AMS changes appear to be in the offing through
midweek so temperatures should be near mid-April averages, with
temperature specifics largely driven by cloud cover.
As the remnants of the upper low lifts into the upper Midwest by
Wednesday evening, upper level low is forecast to develop over the
southern Rockies, with both the GFS and ECMWF eventually cutting
the his low off from the westerlies. In spite of the fact that the
stronger westerly flow (and dynamics) will become established
primarily north of our area, there are suggestions of weak
shortwaves ejecting from the upper low. So, will continue chance
PoPs over most of the CWA for the Thu-Sat time frame, with near
seasonal temperatures.
Truett
&&
.AVIATION: (For the 18z TAFs through 18z Monday Afternoon)
Issued at 120 PM CDT Sun Apr 12 2015
Other than the big wind gust behind this decaying complex of
showers at KCOU a few minutes ago, think things should remain
pretty tranquil untl the cold front arrives later tonight. Have a
period of showers with the front as convection that develops well
to our northwest should be decaying as it progresses south
tonight into Monday morning.
Specifics for KSTL:
VFR conditions expected as rain activity to the west continues to
decay as it moves into dry low level air. Expect a cold front to
approach St. Louis around 12Z and there is a threat of some
showers along it. Wind to veer from southeast to south and then
switch to the northwest behind the front.
CVKING
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1220 PM CDT Sun Apr 12 2015
.UPDATE...
Issued at 1210 PM CDT SUN APR 12 2015
Morning convection exiting eastern CWA faster with partial clearing
following. Strong subsidence on back edge of retreating precipitation
shield resulted in a wake low and winds gusting briefly to 45 mph
with the end of the showers. Have adjusted temperatures down but
western CWA should be able to recover close to 70. Have removed
mention of afternoon precipitation due to stabilizing effect from
morning convective complex, except for the far southeastern counties
where it should end shortly.
Next question is how soon to bring convection back into the CWA. Both
the 12z NAM and trend of HRRR suggest pre-frontal convection could form
very late this afternoon or early evening from south central into
central KS where instability will be maximized and head east. Will
assess other global models before making any significant changes to
tonight`s forecast but seems reasonable we could get a batch of
convection prior to the arrival of the cold front produced
convection. That activity could produce significant rainfall tonight.
&&
.DISCUSSION...
Issued at 335 AM CDT SUN APR 12 2015
Wave of showers and embedded storms over the Plains this morning is
associated with a 35-knot low-level jet and an elevated warm front
around 850 hPa. This activity will likely maintain or even increase
its areal coverage through the morning as the isentropic ascent that
is driving it pushes into western MO around 9 or 10 AM. Storms over
central KS have been somewhat robust early this morning with updrafts
capable of producing penny- to nickel-size hail. This activity has
developed in an area where MUCAPE values are approaching 1000 J/kg,
and this instability will be quite a bit weaker by the time storms
reach the state line. So these storms should weaken by the time they
reach our area later this morning but it wouldn`t be at all
surprising to see some pea- size hail.
Still expect another round of thunderstorms to develop later this
evening as a cold front moves in from the north. It`s looking
increasingly likely that clouds will stick around for much of the
afternoon, so temperatures may struggle to reach 70 degrees which
would keep CAPE values limited to 1500 J/kg or less. This wouldn`t
be particularly supportive of severe storms as the front moves
through after 00Z, especially with shear weakening markedly after
dark. Therefore while a severe storm or two can`t be ruled out, any
hail or damaging wind should be fairly isolated in nature and
confined mostly to far northeast KS and northwest MO in the 6 PM to
10 PM time frame. Decreasing instability after this time would
suggest storms will weaken quite a bit as they approach the I-70
corridor toward midnight. If storms are somehow able to develop ahead
of the main front around or before 00Z, then CAPE/shear profiles over
northwest MO at that time would be more supportive of severe storms.
While there have been a few indications that a pre-frontal surface
trough could do this, the most recent model runs keep storms from
developing until the main front moves through after 00Z and thus
keeping the severe threat low.
Monday and most of Tuesday will see dry weather and seasonable
temperatures followed by a wetter pattern for the remainder of the
week. Showers could return to the region as early as Tuesday evening
when a weak upper wave will drift northeast from the Gulf. More
widespread showers and perhaps thunderstorms are possible later in
the week when models have come into better agreement that a closed
upper low will drift into the area. The inherent low predictability
of such closed lows will make it difficult to pinpoint timing and
location of this precipitation for a few more days.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday Morning)
Issued at 639 AM CDT SUN APR 12 2015
Rain and embedded thunderstorms will overspread the KC area over the
next few hours and taper off by 9 or 10 AM. Highest threat for
thunderstorms through this time will be the southern half of the KC
area and points south. Thunderstorms should weaken as precipitation
spreads into central and north central MO later this morning,
becoming mainly just rain.
A break in the activity is expected for much of the afternoon,
followed by another round of thunderstorms along a cold front late
this evening. A few storms later this evening could be strong with
hail and gusty winds. Went with VC wording this period due to a bit
of uncertainty with coverage, but several indications are that this
activity should take the form of a broken line of storms.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
DISCUSSION...Hawblitzel
AVIATION...Hawblitzel
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
638 AM CDT Sun Apr 12 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 410 AM CDT Sun Apr 12 2015
Activity over eastern KS/western MO is making very slow progress to
the east northeast as it hits the "wall" of drier air over region.
However, models continue to spread higher dewpts into western MO
this morning on nose of low level jet. This in conjunction with a
decent shortwave over central KS, a more substantial area of storms
have developed and the 05z HRRR tracks this complex east northeast
towards forecast area over the next several hours. Scattered showers
and some elevated convection to move through central and northeast
MO, west central IL through midday before diminishing. Otherwise,
main issue for today will be the temperatures. Will see decent cloud
cover today, so will trend towards the cooler guidance and kept
highs in the upper 60s far north to the mid 70s far south, where the
cloud cover may be thinner.
Byrd
.LONG TERM: (Tonight through Saturday)
Issued at 410 AM CDT Sun Apr 12 2015
Primary forecast concerns for tonight and into Monday remain focused
on how to handle the precipitation threat during this time period.
All of the 00z synoptic solutions...as well as the latest available
hi-res output...are continuing earlier trends depicting an
agonizingly slow southeast push of the showers and thunderstorms
overnight tonight. Initially the delay seems to be the result of
the residually dry low level air, but once the moisture does arrive
most of the lift is primarily focused over northwest sections of the
CWA...due to shortwave energy and (by late tonight) forcing along
cold front. Given the good agreement in the solutions I`ve tried to
"think" slow with the progression of PoPs into our southeast
counties, but over NW sections of the FA forecast will push PoPs
into the categorical range by late tonight due the plentiful
moisture in this area as well as the aforementioned lifting
mechanisms, and low level jet advecting unstable air into this area.
Can`t totally rule out a threat of some hail with the overnight
storms, but with the best instability remaining over the Plains the
Day 1 SWO depiction that keeps the primary severe weather threat
west of our CWA looks good.
Precipitation chances will be pushing southeast on Monday with the
cold front, and by afternoon it would appear the only rain threat
left in our CWA will be confined to our far southeast counties.
Placement of PoPs during the morning a bit of a question mark as
there is some uncertainly on how fast the band of showers and storms
over northwest sections of the CWA will wind down during the predawn
hours, but for now will stay fairly close to going trends which has
the northern edge of the morning rain near a KPPQ-KJEF line.
With cold front dropping south of the FA, and with surface ridge
pushing into the region in the front`s wake, dry forecast still
looks good for Monday night and into Tuesday. However, threat of
wet weather will return Tuesday night and Wednesday as remnants of
upper low meanders north-northeast from the southern Plains. For
now, have maintained chance PoPs with this system.
Overall, no big AMS changes appear to be in the offing through
midweek so temperatures should be near mid-April averages, with
temperature specifics largely driven by cloud cover.
As the remnants of the upper low lifts into the upper Midwest by
Wednesday evening, upper level low is forecast to develop over the
southern Rockies, with both the GFS and ECMWF eventually cutting
the his low off from the westerlies. In spite of the fact that the
stronger westerly flow (and dynamics) will become established
primarily north of our area, there are suggestions of weak
shortwaves ejecting from the upper low. So, will continue chance
PoPs over most of the CWA for the Thu-Sat time frame, with near
seasonal temperatures.
Truett
&&
.AVIATION: (For the 12z TAFs through 12z Monday Morning)
Issued at 629 AM CDT Sun Apr 12 2015
Complex of showers and storms to slide east northeast towards
forecast area this morning. But coverage and timing hard to pin
down, so only have vcnty shower mention for KCOU and KUIN at this
time. Otherwise, vfr conditions with winds becoming south and
picking up by mid morning. Next round of more robust activity will
be ahead of cold front tonight with front moving through taf sites
between 10z and 13z Monday. Winds to veer to the northwest behind
the front.
Specifics for KSTL:
Complex of showers and storms to slide east northeast towards
forecast area this morning. But should remain north of STL.
Otherwise, vfr conditions with winds becoming south and picking up
by 16z. Next round of more robust activity will be ahead
of cold front beginning around 07z Monday with front moving through
metro area by 13z Monday. Winds to veer to the northwest behind
the front.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
411 AM CDT Sun Apr 12 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 410 AM CDT Sun Apr 12 2015
Activity over eastern KS/western MO is making very slow progress to
the east northeast as it hits the "wall" of drier air over region.
However, models continue to spread higher dewpts into western MO
this morning on nose of low level jet. This in conjunction with a
decent shortwave over central KS, a more substantial area of storms
have developed and the 05z HRRR tracks this complex east northeast
towards forecast area over the next several hours. Scattered showers
and some elevated convection to move through central and northeast
MO, west central IL through midday before diminishing. Otherwise,
main issue for today will be the temperatures. Will see decent cloud
cover today, so will trend towards the cooler guidance and kept
highs in the upper 60s far north to the mid 70s far south, where the
cloud cover may be thinner.
Byrd
.LONG TERM: (Tonight through Saturday)
Issued at 410 AM CDT Sun Apr 12 2015
Primary forecast concerns for tonight and into Monday remain focused
on how to handle the precipitation threat during this time period.
All of the 00z synoptic solutions...as well as the latest available
hi-res output...are continuing earlier trends depicting an
agonizingly slow southeast push of the showers and thunderstorms
overnight tonight. Initially the delay seems to be the result of
the residually dry low level air, but once the moisture does arrive
most of the lift is primarily focused over northwest sections of the
CWA...due to shortwave energy and (by late tonight) forcing along
cold front. Given the good agreement in the solutions I`ve tried to
"think" slow with the progression of PoPs into our southeast
counties, but over NW sections of the FA forecast will push PoPs
into the categorical range by late tonight due the plentiful
moisture in this area as well as the aforementioned lifting
mechanisms, and low level jet advecting unstable air into this area.
Can`t totally rule out a threat of some hail with the overnight
storms, but with the best instability remaining over the Plains the
Day 1 SWO depiction that keeps the primary severe weather threat
west of our CWA looks good.
Precipitation chances will be pushing southeast on Monday with the
cold front, and by afternoon it would appear the only rain threat
left in our CWA will be confined to our far southeast counties.
Placement of PoPs during the morning a bit of a question mark as
there is some uncertainly on how fast the band of showers and storms
over northwest sections of the CWA will wind down during the predawn
hours, but for now will stay fairly close to going trends which has
the northern edge of the morning rain near a KPPQ-KJEF line.
With cold front dropping south of the FA, and with surface ridge
pushing into the region in the front`s wake, dry forecast still
looks good for Monday night and into Tuesday. However, threat of
wet weather will return Tuesday night and Wednesday as remnants of
upper low meanders north-northeast from the southern Plains. For
now, have maintained chance PoPs with this system.
Overall, no big AMS changes appear to be in the offing through
midweek so temperatures should be near mid-April averages, with
temperature specifics largely driven by cloud cover.
As the remnants of the upper low lifts into the upper Midwest by
Wednesday evening, upper level low is forecast to develop over the
southern Rockies, with both the GFS and ECMWF eventually cutting
the his low off from the westerlies. In spite of the fact that the
stronger westerly flow (and dynamics) will become established
primarily north of our area, there are suggestions of weak
shortwaves ejecting from the upper low. So, will continue chance
PoPs over most of the CWA for the Thu-Sat time frame, with near
seasonal temperatures.
Truett
&&
.AVIATION: (For the 06z TAFs through 06z Sunday Night)
Issued at 1151 PM CDT Sat Apr 11 2015
VFR for at least the first 0-6 hours and probably longer at all
TAF sites except for KUIN, where scattered showers are possible
overnight and towards morning. Confidence is too low to include in
the KUIN TAF attm. Mid and high level clouds will continue to
increase through the period ahead of an approaching disturbance.
Towards the end of the 24hr TAF period and beyond, showers and
thunderstorms are possible when a cold front moves across the
region.
Specifics for KSTL: VFR for at least the first 0-6 hours and
probably longer. Mid and high level clouds will continue to
increase ahead of an approaching disturbance. Rain chances are
highest during the last 6 hours of the 30hr TAF ahead of a cold
front, although a scattered shower is possible earlier. Winds will
briefly turn southwesterly late in the TAF period ahead of the
aforementioned cold front then become northwesterly after fropa.
Kanofsky
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 73 59 71 47 / 10 70 30 10
Quincy 69 56 68 41 / 40 80 10 5
Columbia 72 57 69 44 / 40 80 10 5
Jefferson City 73 58 69 45 / 30 80 20 5
Salem 73 57 71 48 / 10 50 50 10
Farmington 73 57 69 48 / 10 50 50 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1200 AM CDT Sun Apr 12 2015
.DISCUSSION...
Issued at 418 PM CDT SAT APR 11 2015
Tonight - Sunday Night:
A fairly active period as first a weak mid level shortwave tracks
ene out of CO as isentropic lift/warm air advection from 300K-310K
surface expands/increases across KS into MO. This mostly a
reflection of the nocturnal low-level jet ramping up and veering to
the southwest. The sputtering elevated convection over southwest KS
likely in response to the aforementioned h7 shortwave and isentropic
ascent. Have patterned tonight`s PoPs from last several HRRR runs
which is faster and further east with the precipitation. Seems
reasonable as the models typically underplay how far downstream warm
advection convection can extend. Elevated instability looks rather
puny and only a few hundred J/kg so will go with isolated thunder.
Small sub-severe hail possible.
First wave of convection should lift northeast in the morning with
maybe a sputtering second area following close on its heels. How the
morning convection plays out and how much the clouds clear out will
determine the strength of the stronger convection tied to the cold
front. What is interesting is how the NAM generates pre-frontal
convection along an instability axis with progged MLCAPEs in excess
of 2000 J/kg. Since there have been at least 3 consecutive model
runs generating this convection can`t totally dismiss it. The
current forecast is constructed with the idea that pre-frontal
convection will form late afternoon or early evening across
northeast KS and northwest MO with the cold front generated
convection eventually dropping southeast and merging. So, highest
PoPs will be across the northwest 1/2 of the CWA in the evening and
then allow the squalline to steadily translate southeast. The
evening convection could contain some marginally severe hail due to
the moderate instability and 30-40kt 0-6km shear which could support
sufficient updraft strength.
Monday - Tuesday:
Looks like we`ll be in between minor shortwave ridging aloft
shifting across the Northern Plains while a closed upper low lifts
northeast from West TX. Will maintain a dry forecast although there
is some concern that increasing warm air advection and weak lift
tied to the upper low opening up as it heads our way could force us
to add PoPs in later forecasts. Otherwise, dry surface high pressure
on Monday with northeast winds should grant us highs in the 65-70
range. Tuesday should see at least increasing high clouds which will
negate any boundary layer warming so max temperatures should keep
highs in the 60s.
Wednesday - Saturday:
A very uncertain period as the medium range models bounce around
with their solutions. The left overs from the closed upper low will
linger on Wednesday so will use low end chance PoPs to handle any
scattered light convection. Instability looks poor so thunder
chances will be low.
The rest of the period will be handled using a blended model
approach. As the latest GFS is now trending closely with the last
couple of runs of the ECMWF in handling the deep upper trough
tracking through the Rockies am anticipating the next forecast or
the one thereafter going towards drier conditions. The ECMWF has
trended towards developing a cut-off low over the Southern Rockies
and this solution is looking more and more likely, which would mean
delaying PoPs and above average temperatures.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday Night)
Issued at 1200 AM CDT SUN APR 12 2015
Showers and isolated thunderstorms will continue to lift northeast
during the early morning hours, impacting all TAF sites by 07z-08z.
There may be a few brief breaks in precipitation, but periods of
showers and storms are expected through at least mid-morning Sunday.
Ceilings will likely remain VFR; however, visibilities could briefly
drop into the MVFR category in heaviest showers. Precipitation will
taper off by late morning Sunday, then will redevelop along a cold
front near or slightly after 06z.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...Laflin
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1258 AM CDT SUN APR 12 2015
.UPDATE...
ISSUED AT 619 PM CDT SAT APR 11 2015
SENT AN UPDATE TO THE FORECAST TO TRIM THUNDERSTORM CHANCES SOME
THIS EVENING AND OVERNIGHT AS MODEL DATA IS COMING INTO BETTER
AGREEMENT THAT ANY THUNDERSTORM ACTIVITY SHOULD REMAIN ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA...ROUGHLY SOUTH OF HIGHWAY 6 IN
SOUTH CENTRAL NEBRASKA. WHILE THE HRRR DOES SHOW SOME
THUNDERSTORMS MOVING A BIT FURTHER NORTH...THIS MODEL SOLUTION
APPEARS TO BE THE OUTLIER AT THE MOMENT AND PRESENTLY THERE IS
VERY LIMITED CONVECTION TO OUR WEST WHERE IT INDICATES A FAIRLY
WIDESPREAD LINE OF SHOWERS AND THUNDERSTORMS SHOULD BE
DEVELOPING...WHICH FURTHER DISCREDITS THAT SOLUTION. OTHER THAN
TRIMMING THE THUNDERSTORM CHANCES THROUGH THE EARLY MORNING HOURS
SUNDAY...NO ADDITIONAL CHANGES WERE MADE TO THE AFTERNOON FORECAST
PACKAGE.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 323 PM CDT SAT APR 11 2015
SATELLITE AND OBSERVATIONS SHOW CIRRUS AND A FEW MID LEVEL CLOUDS
MOVING INTO THE AREA FROM THE SOUTH THIS AFTERNOON. DEW POINTS HAVE
BEEN INCREASING...BUT VERY SLOWLY.
MODELS HAVE A FEW DIFFERENCES IN LOCATION OF ANY PRECIPITATION
TONIGHT. SOME OF THE SHORT TERM MODELS SHOW SOME SPOTTY TYPE
PRECIPITATION LATE THIS AFTERNOON AND INTO THE EVENING. ALL OF IT
LOOKS TO BE MORE LIKELY IN THE SOUTHERN PART OF THE FORECAST AREA.
HAVE KEPT THE LOW POP IN THE FAR SOUTHWEST FOR LATE THIS AFTERNOON.
WITH THE THUNDERSTORMS IN THE DODGE CITY AREA MOVING TOWARD THE
NORTHEAST THEY COULD GET INTO THE SOUTH BY LATE THIS AFTERNOON.
SATELLITE SHOWS A FEW CUMULUS DEVELOPING A LITTLE TO THE NORTHWEST
OF THESE THUNDERSTORMS. THE BETTER CHANCES WILL BE THIS EVENING
MAINLY ACROSS KANSAS AND NEARBY AREAS OF NEBRASKA.
THE SAME CONCERNS LINGER INTO SUNDAY MORNING. THE NAM HAS THE
PRECIPITATION MOVING OUT OF THE AREA WHILE THE GFS KEEPS IT ACROSS
THE SOUTHEAST. WILL KEEP SOME LOW POPS IN THE EAST/SOUTHEAST FOR
SUNDAY MORNING. EXPECT THAT THE PRECIPITATION WILL MOVE OUT OF THE
AREA BY MID DAY.
THE NEXT CONCERN WILL BE A COLD FRONT THAT MOVES INTO THE NORTHWEST
DURING THE MORNING HOURS. WINDS WILL TURN TO THE NORTHWEST BEHIND
THE FRONT. BY AFTERNOON THE FRONT WILL BE IN THE EASTERN PART OF THE
FORECAST AREA. MOST MODELS DEVELOP THUNDERSTORMS ALONG THE FRONT
DURING THE AFTERNOON HOURS. THE LOCATION OF THE FRONT AND WHEN THE
THUNDERSTORMS DEVELOP WILL DETERMINE HOW MUCH OF THE AREA WILL HAVE
THUNDERSTORMS. HAVE KEPT THEM MOSTLY IN THE EAST DURING THE
AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 323 PM CDT SAT APR 11 2015
THE WEEK WILL START DRY AND SEASONAL. SURFACE HIGH PRESSURE WILL
DRIFT ACROSS THE FORECAST AREA MONDAY AFTERNOON. AFTER A COOLISH
START...LIGHT WINDS...SUNSHINE AND MILD TEMPERATURES WILL MAKE
FOR A VERY NICE AFTERNOON AND EARLY EVENING. RELATIVE HUMIDITY
VALUES WILL BE VERY LOW WITH AMBIENT DRY AIR...BUT LIGHT WINDS
WILL KEEP THE NEED FOR ANY CRITICAL FIRE WEATHER CONDITION
PRODUCTS/HEADLINES AT BAY.
TUESDAY SHOULD BE ANOTHER DRY DAY...BUT FIRE WEATHER CONCERNS
START TO CREEP INTO THE FORECAST. LOOK FOR STRONG SOUTH WINDS
TEMPERATURES SLIGHTLY ABOVE NORMAL. MODELS ALWAYS TRY TO PUSH
MOISTURE RETURN IN SOUTHERLY FLOW BACK TOO QUICK EARLY IN THE
SEASON...AND BELIEVE THAT WILL BE THE CASE HERE. LOOKS LIKE A
DECENT BET CRITICAL FIRE WEATHER CONDITIONS WILL BE REACHED FOR
SOME AREAS LATE TUESDAY AFTERNOON. MAY NOT BE ALL AREAS...AND DOES
FAVOR THE ABOUT THE NORTHWEST 2/3RDS OF THE FORECAST AREA.
THE REST OF WEEK IS A REALLY CHALLENGING FORECAST AT THIS POINT
AND THE FORECAST WILL LIKELY CHANGE DAILY AS FINER DETAILS
OPEN UP A BIT. THE MAIN ISSUE IS WHETHER A CUT OFF LOW WILL
FORM/MEANDER ITS WAY THROUGH THE PLAINS OR NOT. THE ANSWER
IS STILL QUITE AN UNKNOWN. THERE ARE DIFFERENCES IN THE HANDLING OF
A SOUTHERN STREAM UPPER WAVE...FOR WHICH THE GFS IS MOST AGGRESSIVE
BRING LIGHT RAIN INTO THE REGION TUESDAY NIGHT. THE ECMWF
TENDS TO FOCUS MORE ON THE APPROACHING TROUGH FROM THE WEST BY
MIDWEEK AND DIGS THAT FEATURE. THERE ARE SOME SIMILARITIES
WITH THE EC/GFS BOTH DIGGING A CUT OFF TYPE LOW IN THE REGION BUT
THERE ARE BIG DIFFERENCES FROM THAT POINT ON. 12Z EC IS NOW HOLDING
THE LOW BACK TO THE SOUTHWEST OF NEBRASKA...WHICH MAY KEEP THE
BETTER RAIN CHANCES ACROSS KANSAS. AND THE CANADIAN MODEL JUST SLIPS
AN OPEN WAVE ACROSS THE REGION WITH VERY LITTLE ISSUE. POINT
IS...THERE IS SOME RAIN CHANCE...BUT LOTS OF UNCERTAINTY WITH THE
WEDNESDAY-FRIDAY PERIOD.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1253 AM CDT SUN APR 12 2015
THE BIGGEST QUESTION MARK WILL CENTER AROUND THE POSSIBILITY OF
LOW CLOUDS WORKING UP INTO OUR TAF SITES AS WE NEAR DAWN. SOME OF
THE MODELS HAVE BEEN HINTING AT MVFR OR EVEN IFR CEILINGS AROUND
DAWN...BUT BASED ON WHERE THE STRATUS IS NOW AM NOT VERY CONFIDENT
THAT WE WILL SEE THOSE LOWER CEILINGS. THEREFORE...WILL CONTINUE
TO CARRY VFR CEILINGS THIS MORNING...BUT WE MAY NEED TO UPDATE TO
DECREASE CEILING HEIGHTS DEPENDING ON HOW FAR NORTH THAT KANSAS
CLOUD DECK CAN MAKE IT. THERE WILL BE A WIND SHIFT THIS AFTERNOON
WITH A FRONTAL PASSAGE AND THE WIND WILL BRIEFLY PICK UP OUT OF
THE NORTH NORTHWEST BEHIND THE FRONT BEFORE DIMINISHING AROUND
SUNSET WITH THE LOSS OF DIURNAL HEATING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...ROSSI
SHORT TERM...JCB
LONG TERM...MORITZ
AVIATION...WESELY
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1019 PM EDT MON APR 13 2015
.SYNOPSIS...
A COASTAL TROUGH JUST OFF THE COAST WILL LIFT NORTHWARD OVERNIGHT.
A COLD FRONT WILL CROSS THE AREA EARLY WEDNESDAY MORNING...STALLING
TO OUR SOUTH ON THURSDAY. LOW PRESSURE MAY DEVELOP ALONG THE FRONT
THURSDAY INTO FRIDAY..LIFTING NORTH OF THE AREA SATURDAY. A COLD
FRONT WILL MOVE ACROSS THE CAROLINAS FROM THE WEST LATE SATURDAY.
HIGH PRESSURE WILL BUILD IN FROM THE WEST SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 1030 PM MONDAY...SHOWERS HAVE BECOME QUITE FRAGMENTED ACROSS
THE AREA...HOWEVER THE ENVIRONMENT REMAINS CONDUCIVE FOR NEW
SHOWERS TO DEVELOP AT ALMOST ANY TIME...ESPECIALLY ACROSS THE
CAPE FEAR AREA. FOR WILMINGTON THE STRONGEST MAGNITUDE OF WARM
ADVECTION SHOULD BE OCCURRING IN THE NEXT FEW HOURS. SMALL BUT
POSITIVE CONVECTIVE INSTABILITY IS STILL PRESENT AS WELL...WITH
KLTX RADAR SHOWING NEW CELLS DEVELOPING VERY NEAR THE RADAR SITE
IN BRUNSWICK COUNTY OVER THE PAST HALF HOUR.
IT IS TOUGH TO SAY WHICH MODEL IS PERFORMING WELL. THE HRRR IS
MAINTAINING A VERY DRY FORECAST OVERNIGHT...BUT RADAR SUMMARIES
PLUS THE OVERALL SYNOPTIC SITUATION ARGUE OTHERWISE. I WILL
MAINTAIN FAIRLY HIGH POPS (60-70 PERCENT) IN THE WILMINGTON METRO
AREA...WITH LOWER POPS (30-50 PERCENT) ELSEWHERE FOR THE OVERNIGHT
PERIOD. NO CHANGES TO TEMPERATURES. DISCUSSION FROM 730 PM
FOLLOWS...
RADAR IMAGERY SHOWS A CLUSTER OF SHOWERS ASSOCIATED WITH SE
INFLOW OFF THE ATLANTIC ACROSS THE MYRTLE BEACH AREA...SPREADING
NORTH- NORTHWESTWARD. MODELS SUGGEST THESE SHOWERS ARE BEING
SUSTAINED BY TWO FACTORS: WEAK LIFT RESULTING FROM A SURGE OF WARM
ADVECTION BELOW 800 MB...COUPLED WITH AROUND 100 J/KG OF
CONVECTIVE INSTABILITY. A LESS ORGANIZED AREA OF SHOWERS ACROSS
CENTRAL SOUTH CAROLINA APPROACHING DARLINGTON AND FLORENCE
COUNTIES IS ROOTED HIGHER UP IN THE ATMOSPHERE WHERE WIND FLOW IS
SOUTHWESTERLY. THESE ARE MAINLY THE RESULT OF WEAK ISENTROPIC LIFT
ALONG THE 305K THETA SURFACE WHICH SHOULD ABATE BY MIDNIGHT.
MODELS ARE IN PRETTY GREAT DISAGREEMENT ABOUT PRECIPITATION
COVERAGE AND INTENSITY OVERNIGHT. THE 18Z NAM PROBABLY HAS THE
BEST HANDLE ON PRECIPITATION TRIGGERS I CAN ANALYZE. I ALSO LIKE
HOW THE 18Z NAM SEEMS TO BE ONE OF THE FEW MODELS TO SEE THAT
SURFACE WINDS ARE NOT VEERING WILDLY AROUND TO THE SE AT THE
COAST. (THE 22Z RAP PROBABLY HAS THE BEST HANDLE ON WINDS
CURRENTLY)
MY IDEA...BASED PRIMARILY ON THE NAM AND THE PREVIOUS FORECASTER`S
WORK...IS THAT THE BAND OF SUBSTANTIAL SHOWER ACTIVITY NEAR MYRTLE
BEACH WILL HAVE LIMITED SUCCESS WORKING INLAND...AND WILL INSTEAD
PREFERENTIALLY SHIFT NORTHWARD ALONG THE COAST AFFECTING
WILMINGTON AND THE CAPE FEAR AREA AFTER MIDNIGHT. THE ACTIVITY
ACROSS CENTRAL SC WILL MOVE NORTHEASTWARD DROPPING SPOTTIER
RAINFALL...AND DIMINISHING IN COVERAGE BY MIDNIGHT AS LIFT ALONG
THE 305K AND 310K ISENTROPIC SURFACES DIMINISHES.
PLENTY OF CLOUDS AND DEWPOINTS RISING INTO THE 60S WILL HOLD LOWS
IN THE MID 60S FOR MOST LOCATIONS...VIRTUALLY UNCHANGED FROM THE
PREVIOUS FORECAST.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY... FORECAST SOUNDINGS SHOW A DEEP LAYER OF
SATURATION FOR MUCH OF TUESDAY. AND WHILE THE ENTIRE DAY WILL NOT BE
A WASHOUT IT IS QUITE DIFFICULT TO HAVE ANY GIVEN HOUR WITH LOW POPS
DUE TO SEVERAL SMALL SCALE PERTURBATIONS MOVING THROUGH THE FLOW.
GIVEN WIDESPREAD CLOUD COVER MODELS HAVING DIFFICULTY DISCERNING HOW
MUCH INSTABILITY DEVELOPS. REGARDLESS THERE WILL BE ENOUGH FOR
ISOLATED THUNDER BUT BREAKS OR SUFFICIENT THINNING IN CLOUDS COULD
LEAD TO ENOUGH INSTABILITY SUCH THAT SPC HAS REFERENCED NC IN SWODY2.
CHANCE FOR ACTUAL SEVERE WEATHER TOO LOW FOR EVEN A `MARGINAL`
ISOPLETH IN THE OUTLOOK. GIVEN RELATIVELY LOW LCLS/MEAGER LAPSE
RATES FAVORING FAIRLY THIN BUT TALL CAPE AND THE LACK OF ANY DRY
AIR THE MAIN `THREAT` WILL BE NON-SEVERE (20-40MPH) WET
DOWNBURSTS. THE GFS DOES SHOW SOME DRYING AND THE DEVELOPMENT OF
DCAPE BY 00Z DUE TO THE EXIT OF DAY`S STRONGEST SHORTWAVE BUT MUCH
PAST PEAK HEATING THERE MAY NOT BE SUFFICIENT LIFT REMAINING FOR
DEEP CONVECTION. COLD FRONT PUSHES THROUGH DURING THE LATTER HALF
OF TUESDAY NIGHT ENDING MOST IF NOT ALL OF THE LIGHTNING AS LOW
LEVELS STRONGLY STABILIZE UNDERNEATH INVERSION AND LIFT REMAINS
TOO WEAK TO TAP ELEVATED INSTABILITY, IF ANY. LIGHT STRATIFORM
RAIN THEN STAYS IN THE FORECAST FOR MUCH OF WEDNESDAY AS THE
SURFACE WEDGE CONTINUES TO EXPERIENCE WEAK OVERRUNNING. HIGH TEMPS
FROM TUESDAY TO WEDNESDAY WILL GO FROM ROUGHLY 5 DEGREES ABOVE
CLIMO TO ROUGHLY 5 DEGREES BELOW. GIVEN THE STRENGTH OF THE WEDGE
WOULD NOT BE SURPRISED IF WEDNESDAY HIGHS NEED TO BE LOWERED A FEW
DEGREES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...MID LEVEL RIDGING OVER THE WESTERN ATLANTIC AND
GULF OF MEXICO ALONG WITH 5H TROUGHING/CUTOFF OVER THE SOUTHWEST
CONUS WILL SPREAD DEEP MOISTURE OVER THE SOUTHEAST INTO THE START OF
NEXT WEEK. IN ADDITION TO THE DEEP MOISTURE THE SOUTHWEST FLOW ALOFT
WILL ENSURE A STEADY SERIES OF SHORTWAVES EJECTING FROM THE 5H
CUTOFF PASS OVER THE REGION. THESE WAVES MAY WORK TO ENHANCE DIURNAL
CONVECTION...DEPENDING ON THEIR TIMING. TIMING THESE FEATURES IN THE
EXTENDED IS DIFFICULT AT BEST AND GIVEN THE UNCERTAINTY WITH RESPECT
TO AVAILABLE DIURNAL INSTABILITY AS WELL AS THE LOCATION OF ANY
LINGERING CONVECTIVE BOUNDARIES DO NOT PLAN ON ANY MAJOR CHANGES TO
POP FORECAST AT THIS TIME.
TEMPERATURES THU WILL BE NEAR TO BELOW CLIMO WITH HIGH PRESSURE
RIDGING DOWN THE COAST FROM THE NORTHEAST. THE PARENT HIGH MOVES OFF
THE NEW ENGLAND COAST BY FRI...BREAKING THE RIDGE AND ALLOWING
PASSAGE OF WEAK WARM FRONT/COASTAL TROUGH. THIS WILL USHER IN A
PERIOD OF HIGHS AND LOWS ABOVE TO WELL ABOVE CLIMO BUT IS ALSO
LIKELY TO KEEP PRECIP CHANCES ELEVATED THROUGH THE WEEKEND. CUTOFF
EMERGING FROM THE SOUTHWEST THIS WEEKEND WILL HELP DRAG A COLD FRONT
ACROSS THE AREA LATE IN THE PERIOD. STILL SOME UNCERTAINTY WITH
RESPECT TO TIMING BUT GFS IS A BIT FASTER...SUN NIGHT...WHILE THE
ECMWF IS SLOWER...LATER MON.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...BAND OF SHOWERS AFFECTING THE GRAND STRAND AND
WORKING TOWARD FLO...RESULTING IN MVFR AND IFR CIGS AT TIMES THOSE
TERMINALS WHILE ILM AND LBT ARE PREDOMINANTLY VFR. ALL IN
ALL...EXPECT DETERIORATING CONDITIONS ALL TERMINALS TONIGHT WITH
MVFR OR EVEN IFR CONDITIONS AT ALL SITES...MAINLY DUE TO CIGS.
ADDITIONALLY...SHOWERS ARE POSSIBLE MUCH OF THE NIGHT...ESPECIALLY
ALONG THE COAST. AFTER DAYBREAK CONDITIONS SHOULD IMPROVE TO MVFR
OR EVEN VFR ON S TO SW WINDS INVOF 10 KT BUT SHRA AND TSRA ARE
POSSIBLE ALL TERMINALS FOR MUCH OF THE DAY WITH MVFR OR TEMPO IFR
POSSIBLE.
EXTENDED OUTLOOK...WED...A CHANCE OF MVFR IN THUNDERSTORMS.
MVFR/SHOWERS THURS THROUGH FRI. VFR SAT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM MONDAY...WIND SPEEDS NEARSHORE HAVE DIMINISHED OVER
THE PAST FEW HOURS WHILE WINDS OFFSHORE CONTINUE TO BLOW 15-20 KT
ACCORDING TO THE FRYING PAN SHOALS AND OFFSHORE WRIGHTSVILLE BEACH
(41037) BUOYS. THE COASTAL TROUGH IS TOUGH TO LOCATE BUT IS
PROBABLY 5-10 MILES OFFSHORE...AND SHOULD PUSH ACROSS OUR ENTIRE
MARINE AREA IN THE NEXT 3-5 HOURS. THIS WILL ALLOW WIND DIRECTIONS
TO VEER EAST-SOUTHEASTERLY ALL THE WAY UP TO THE BEACHES.
SHOWERS HAVE DIMINISHED OVERALL BUT THE ENVIRONMENT REMAINS
SUPPORTIVE OF NEW SHOWERS TO DEVELOP AT ANY TIME...MAINLY NORTH OF
MYRTLE BEACH ACROSS THE CAPE FEAR AREA WATERS. I AM MAINTAINING
HIGH CHANCES FOR SHOWERS IN THE FORECAST HERE. DISCUSSION FROM 730
PM FOLLOWS...
A COASTAL TROUGH IS HELPING TO KEEP WIND DIRECTIONS BACKED AROUND
TO THE EAST AND NORTHEAST ALONG THE COAST...WHILE FARTHER OFFSHORE
AT THE FRYING PAN SHOALS BUOY AND THE EDISTO BUOY WINDS HAVE
ALREADY SWUNG AROUND TO THE SOUTHEAST. THIS BOUNDARY SHOULD LIFT
NORTHWARD ALMOST LIKE A WEAK WARM FRONT TONIGHT...ALLOWING WINDS
EVEN AT THE BEACHES TO ASSUME A MORE SOUTHERLY DIRECTION BY
DAYBREAK TUESDAY.
AN AREA OF SUBSTANTIAL SHOWER ACTIVITY NEAR MYRTLE BEACH SHOULD
GRADUALLY LIFT NORTH ALONG THE COAST TONIGHT...REACHING CAPE FEAR
BY MIDNIGHT. SEAS CURRENTLY 3-5 FEET SHOULD MAINTAIN THEMSELVES
WITH A STEADY ONSHORE WIND EXPECTED TO CONTINUE.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY... SOUTH TO SOUTHWESTERLY FLOW ON TUESDAY IN A
PREFRONTAL FLOW REGIME AS BOUNDARY APPROACHES FROM THE NORTHWEST.
NEITHER WINDS NOR SEAS WILL BE PARTICULARLY STIRRED UP SO THE MAIN
THREAT TO MARINERS WILL BE THE FACT THAT SOME SHOWERS AND STORMS
COULD PRODUCE HEAVY ENOUGH RAINFALL FOR SOME VISIBILITY
RESTRICTIONS IN ADDITION TO SOME FAIRLY GUSTY (30-40KT) WINDS.
LATE NIGHT FROPA MAY CHANGE THAT HOWEVER AS A WEDGE OF HIGH
PRESSURE STARTS GETTING ESTABLISHED OVER LAND. AS THIS FEATURE
STRENGTHENS IN PART DUE TO RAIN FALLING INTO IT THE GRADIENT AND
RESULTING WIND/SEAS WILL RISE. AN ADVISORY WILL BE HOISTED AT SOME
POINT THOUGH ACTUAL ADVISORY CONDITIONS/6FT SEAS LIKELY NOT
MATERIALIZING TIL NIGHTTIME.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...PINCHED GRADIENT BETWEEN HIGH RIDGING IN FROM
THE NORTH AND COASTAL TROUGH WILL MAINTAIN NORTHEAST FLOW IN THE
20 TO 25 KT RANGE THU AND THU NIGHT. EXTENDED PERIOD OF INCREASED
NORTHEAST FLOW WILL KEEP SEAS OVER 6 FT ACROSS MUCH OF THE WATERS
AND HEADLINES ARE LIKELY TO BE CARRIED OVER FROM THE SHORT TERM
PERIOD. GRADIENT WEAKENS FRI AS THE HIGH SHIFTS EAST AS TROUGH
MOVES ONSHORE/LIFTS NORTH. AS THIS OCCURS WINDS WILL SHIFT FROM
NORTHEAST THU NIGHT TO EAST LATER FRI WITH SOUTHWEST FLOW
DEVELOPING LAT FRI NIGHT AND CONTINUING ON SAT. WEAKER GRADIENT
FRI AND SAT WILL KEEP SPEEDS GENERALLY 10 KT OR LESS WITH SEAS
DECREASING FROM 3 TO 5 FT FRI MORNING TO 2 TO 3 FT SAT AFTERNOON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...III
AVIATION...RAN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
812 PM EDT MON APR 13 2015
.SYNOPSIS...
A COASTAL TROUGH JUST OFF THE COAST WILL LIFT NORTHWARD OVERNIGHT.
A COLD FRONT WILL CROSS THE AREA EARLY WEDNESDAY MORNING...STALLING
TO OUR SOUTH ON THURSDAY. LOW PRESSURE MAY DEVELOP ALONG THE FRONT
THURSDAY INTO FRIDAY..LIFTING NORTH OF THE AREA SATURDAY. A COLD
FRONT WILL MOVE ACROSS THE CAROLINAS FROM THE WEST LATE SATURDAY.
HIGH PRESSURE WILL BUILD IN FROM THE WEST SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 730 PM MONDAY...RADAR IMAGERY SHOWS A CLUSTER OF SHOWERS
ASSOCIATED WITH SE INFLOW OFF THE ATLANTIC ACROSS THE MYRTLE BEACH
AREA...SPREADING NORTH-NORTHWESTWARD. MODELS SUGGEST THESE SHOWERS
ARE BEING SUSTAINED BY TWO FACTORS: WEAK LIFT RESULTING FROM A
SURGE OF WARM ADVECTION BELOW 800 MB...COUPLED WITH AROUND 100
J/KG OF CONVECTIVE INSTABILITY. A LESS ORGANIZED AREA OF SHOWERS
ACROSS CENTRAL SOUTH CAROLINA APPROACHING DARLINGTON AND FLORENCE
COUNTIES IS ROOTED HIGHER UP IN THE ATMOSPHERE WHERE WIND FLOW IS
SOUTHWESTERLY. THESE ARE MAINLY THE RESULT OF WEAK ISENTROPIC
LIFT ALONG THE 305K THETA SURFACE WHICH SHOULD ABATE BY MIDNIGHT.
MODELS ARE IN PRETTY GREAT DISAGREEMENT ABOUT PRECIPITATION
COVERAGE AND INTENSITY OVERNIGHT. THE 18Z NAM PROBABLY HAS THE
BEST HANDLE ON PRECIPITATION TRIGGERS I CAN ANALYZE. I ALSO LIKE
HOW THE 18Z NAM SEEMS TO BE ONE OF THE FEW MODELS TO SEE THAT
SURFACE WINDS ARE NOT VEERING WILDLY AROUND TO THE SE AT THE
COAST. (THE 22Z RAP PROBABLY HAS THE BEST HANDLE ON WINDS
CURRENTLY)
MY IDEA...BASED PRIMARILY ON THE NAM AND THE PREVIOUS FORECASTER`S
WORK...IS THAT THE BAND OF SUBSTANTIAL SHOWER ACTIVITY NEAR MYRTLE
BEACH WILL HAVE LIMITED SUCCESS WORKING INLAND...AND WILL INSTEAD
PREFERENTIALLY SHIFT NORTHWARD ALONG THE COAST AFFECTING
WILMINGTON AND THE CAPE FEAR AREA AFTER MIDNIGHT. THE ACTIVITY
ACROSS CENTRAL SC WILL MOVE NORTHEASTWARD DROPPING SPOTTIER
RAINFALL...AND DIMINISHING IN COVERAGE BY MIDNIGHT AS LIFT ALONG
THE 305K AND 310K ISENTROPIC SURFACES DIMINISHES.
PLENTY OF CLOUDS AND DEWPOINTS RISING INTO THE 60S WILL HOLD LOWS
IN THE MID 60S FOR MOST LOCATIONS...VIRTUALLY UNCHANGED FROM THE
PREVIOUS FORECAST.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY... FORECAST SOUNDINGS SHOW A DEEP LAYER OF
SATURATION FOR MUCH OF TUESDAY. AND WHILE THE ENTIRE DAY WILL NOT BE
A WASHOUT IT IS QUITE DIFFICULT TO HAVE ANY GIVEN HOUR WITH LOW POPS
DUE TO SEVERAL SMALL SCALE PERTURBATIONS MOVING THROUGH THE FLOW.
GIVEN WIDESPREAD CLOUD COVER MODELS HAVING DIFFICULTY DISCERNING HOW
MUCH INSTABILITY DEVELOPS. REGARDLESS THERE WILL BE ENOUGH FOR
ISOLATED THUNDER BUT BREAKS OR SUFFICIENT THINNING IN CLOUDS COULD
LEAD TO ENOUGH INSTABILITY SUCH THAT SPC HAS REFERENCED NC IN SWODY2.
CHANCE FOR ACTUAL SEVERE WEATHER TOO LOW FOR EVEN A `MARGINAL`
ISOPLETH IN THE OUTLOOK. GIVEN RELATIVELY LOW LCLS/MEAGER LAPSE
RATES FAVORING FAIRLY THIN BUT TALL CAPE AND THE LACK OF ANY DRY
AIR THE MAIN `THREAT` WILL BE NON-SEVERE (20-40MPH) WET
DOWNBURSTS. THE GFS DOES SHOW SOME DRYING AND THE DEVELOPMENT OF
DCAPE BY 00Z DUE TO THE EXIT OF DAY`S STRONGEST SHORTWAVE BUT MUCH
PAST PEAK HEATING THERE MAY NOT BE SUFFICIENT LIFT REMAINING FOR
DEEP CONVECTION. COLD FRONT PUSHES THROUGH DURING THE LATTER HALF
OF TUESDAY NIGHT ENDING MOST IF NOT ALL OF THE LIGHTNING AS LOW
LEVELS STRONGLY STABILIZE UNDERNEATH INVERSION AND LIFT REMAINS
TOO WEAK TO TAP ELEVATED INSTABILITY, IF ANY. LIGHT STRATIFORM
RAIN THEN STAYS IN THE FORECAST FOR MUCH OF WEDNESDAY AS THE
SURFACE WEDGE CONTINUES TO EXPERIENCE WEAK OVERRUNNING. HIGH TEMPS
FROM TUESDAY TO WEDNESDAY WILL GO FROM ROUGHLY 5 DEGREES ABOVE
CLIMO TO ROUGHLY 5 DEGREES BELOW. GIVEN THE STRENGTH OF THE WEDGE
WOULD NOT BE SURPRISED IF WEDNESDAY HIGHS NEED TO BE LOWERED A FEW
DEGREES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...MID LEVEL RIDGING OVER THE WESTERN ATLANTIC AND
GULF OF MEXICO ALONG WITH 5H TROUGHING/CUTOFF OVER THE SOUTHWEST
CONUS WILL SPREAD DEEP MOISTURE OVER THE SOUTHEAST INTO THE START OF
NEXT WEEK. IN ADDITION TO THE DEEP MOISTURE THE SOUTHWEST FLOW ALOFT
WILL ENSURE A STEADY SERIES OF SHORTWAVES EJECTING FROM THE 5H
CUTOFF PASS OVER THE REGION. THESE WAVES MAY WORK TO ENHANCE DIURNAL
CONVECTION...DEPENDING ON THEIR TIMING. TIMING THESE FEATURES IN THE
EXTENDED IS DIFFICULT AT BEST AND GIVEN THE UNCERTAINTY WITH RESPECT
TO AVAILABLE DIURNAL INSTABILITY AS WELL AS THE LOCATION OF ANY
LINGERING CONVECTIVE BOUNDARIES DO NOT PLAN ON ANY MAJOR CHANGES TO
POP FORECAST AT THIS TIME.
TEMPERATURES THU WILL BE NEAR TO BELOW CLIMO WITH HIGH PRESSURE
RIDGING DOWN THE COAST FROM THE NORTHEAST. THE PARENT HIGH MOVES OFF
THE NEW ENGLAND COAST BY FRI...BREAKING THE RIDGE AND ALLOWING
PASSAGE OF WEAK WARM FRONT/COASTAL TROUGH. THIS WILL USHER IN A
PERIOD OF HIGHS AND LOWS ABOVE TO WELL ABOVE CLIMO BUT IS ALSO
LIKELY TO KEEP PRECIP CHANCES ELEVATED THROUGH THE WEEKEND. CUTOFF
EMERGING FROM THE SOUTHWEST THIS WEEKEND WILL HELP DRAG A COLD FRONT
ACROSS THE AREA LATE IN THE PERIOD. STILL SOME UNCERTAINTY WITH
RESPECT TO TIMING BUT GFS IS A BIT FASTER...SUN NIGHT...WHILE THE
ECMWF IS SLOWER...LATER MON.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 18Z...BAND OF SHOWERS AFFECTING THE GRAND STRAND AND WORKING
TOWARD FLO...RESULTING IN MVFR AND IFR CIGS AT TIMES THOSE TERMINALS
WHILE ILM AND LBT ARE PREDOMINANTLY VFR. ALL IN ALL...EXPECT
DETERIORATING CONDITIONS ALL TERMINALS TONIGHT WITH MVFR OR EVEN IFR
CONDITIONS AT ALL SITES...MAINLY DUE TO CIGS.
ADDITIONALLY...SHOWERS ARE POSSIBLE MUCH OF THE NIGHT...ESPECIALLY
ALONG THE COAST. AFTER DAYBREAK CONDITIONS SHOULD IMPROVE TO MVFR
OR EVEN VFR ON S TO SW WINDS INVOF 10 KT BUT SHRA AND TSRA ARE
POSSIBLE ALL TERMINALS FOR MUCH OF THE DAY WITH MVFR OR TEMPO IFR
POSSIBLE.
EXTENDED OUTLOOK...WED...A CHANCE OF MVFR IN THUNDERSTORMS.
MVFR/SHOWERS THURS THROUGH FRI. VFR SAT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM MONDAY...A COASTAL TROUGH IS HELPING TO KEEP WIND
DIRECTIONS BACKED AROUND TO THE EAST AND NORTHEAST ALONG THE
COAST...WHILE FARTHER OFFSHORE AT THE FRYING PAN SHOALS BUOY AND
THE EDISTO BUOY WINDS HAVE ALREADY SWUNG AROUND TO THE SOUTHEAST.
THIS BOUNDARY SHOULD LIFT NORTHWARD ALMOST LIKE A WEAK WARM FRONT
TONIGHT...ALLOWING WINDS EVEN AT THE BEACHES TO ASSUME A MORE
SOUTHERLY DIRECTION BY DAYBREAK TUESDAY.
AN AREA OF SUBSTANTIAL SHOWER ACTIVITY NEAR MYRTLE BEACH SHOULD
GRADUALLY LIFT NORTH ALONG THE COAST TONIGHT...REACHING CAPE FEAR
BY MIDNIGHT. SEAS CURRENTLY 3-5 FEET SHOULD MAINTAIN THEMSELVES
WITH A STEADY ONSHORE WIND EXPECTED TO CONTINUE.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY... SOUTH TO SOUTHWESTERLY FLOW ON TUESDAY IN A
PREFRONTAL FLOW REGIME AS BOUNDARY APPROACHES FROM THE NORTHWEST.
NEITHER WINDS NOR SEAS WILL BE PARTICULARLY STIRRED UP SO THE MAIN
THREAT TO MARINERS WILL BE THE FACT THAT SOME SHOWERS AND STORMS
COULD PRODUCE HEAVY ENOUGH RAINFALL FOR SOME VISIBILITY
RESTRICTIONS IN ADDITION TO SOME FAIRLY GUSTY (30-40KT) WINDS.
LATE NIGHT FROPA MAY CHANGE THAT HOWEVER AS A WEDGE OF HIGH
PRESSURE STARTS GETTING ESTABLISHED OVER LAND. AS THIS FEATURE
STRENGTHENS IN PART DUE TO RAIN FALLING INTO IT THE GRADIENT AND
RESULTING WIND/SEAS WILL RISE. AN ADVISORY WILL BE HOISTED AT SOME
POINT THOUGH ACTUAL ADVISORY CONDITIONS/6FT SEAS LIKELY NOT
MATERIALIZING TIL NIGHTTIME.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...PINCHED GRADIENT BETWEEN HIGH RIDGING IN FROM
THE NORTH AND COASTAL TROUGH WILL MAINTAIN NORTHEAST FLOW IN THE
20 TO 25 KT RANGE THU AND THU NIGHT. EXTENDED PERIOD OF INCREASED
NORTHEAST FLOW WILL KEEP SEAS OVER 6 FT ACROSS MUCH OF THE WATERS
AND HEADLINES ARE LIKELY TO BE CARRIED OVER FROM THE SHORT TERM
PERIOD. GRADIENT WEAKENS FRI AS THE HIGH SHIFTS EAST AS TROUGH
MOVES ONSHORE/LIFTS NORTH. AS THIS OCCURS WINDS WILL SHIFT FROM
NORTHEAST THU NIGHT TO EAST LATER FRI WITH SOUTHWEST FLOW
DEVELOPING LAT FRI NIGHT AND CONTINUING ON SAT. WEAKER GRADIENT
FRI AND SAT WILL KEEP SPEEDS GENERALLY 10 KT OR LESS WITH SEAS
DECREASING FROM 3 TO 5 FT FRI MORNING TO 2 TO 3 FT SAT AFTERNOON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...TRA/RGZ
SHORT TERM...MBB
LONG TERM...III
AVIATION...XXXI
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
744 PM EDT MON APR 13 2015
.SYNOPSIS...
A COASTAL TROUGH JUST OFF THE COAST WILL LIFT NORTHWARD OVERNIGHT.
A COLD FRONT WILL CROSS THE AREA EARLY WEDNESDAY MORNING...STALLING
TO OUR SOUTH ON THURSDAY. LOW PRESSURE MAY DEVELOP ALONG THE FRONT
THURSDAY INTO FRIDAY..LIFTING NORTH OF THE AREA SATURDAY. A COLD
FRONT WILL MOVE ACROSS THE CAROLINAS FROM THE WEST LATE SATURDAY.
HIGH PRESSURE WILL BUILD IN FROM THE WEST SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 730 PM MONDAY...RADAR IMAGERY SHOWS A CLUSTER OF SHOWERS
ASSOCIATED WITH SE INFLOW OFF THE ATLANTIC ACROSS THE MYRTLE BEACH
AREA...SPREADING NORTH-NORTHWESTWARD. MODELS SUGGEST THESE SHOWERS
ARE BEING SUSTAINED BY TWO FACTORS: WEAK LIFT RESULTING FROM A
SURGE OF WARM ADVECTION BELOW 800 MB...COUPLED WITH AROUND 100
J/KG OF CONVECTIVE INSTABILITY. A LESS ORGANIZED AREA OF SHOWERS
ACROSS CENTRAL SOUTH CAROLINA APPROACHING DARLINGTON AND FLORENCE
COUNTIES IS ROOTED HIGHER UP IN THE ATMOSPHERE WHERE WIND FLOW IS
SOUTHWESTERLY. THESE ARE MAINLY THE RESULT OF WEAK ISENTROPIC
LIFT ALONG THE 305K THETA SURFACE WHICH SHOULD ABATE BY MIDNIGHT.
MODELS ARE IN PRETTY GREAT DISAGREEMENT ABOUT PRECIPITATION
COVERAGE AND INTENSITY OVERNIGHT. THE 18Z NAM PROBABLY HAS THE
BEST HANDLE ON PRECIPITATION TRIGGERS I CAN ANALYZE. I ALSO LIKE
HOW THE 18Z NAM SEEMS TO BE ONE OF THE FEW MODELS TO SEE THAT
SURFACE WINDS ARE NOT VEERING WILDLY AROUND TO THE SE AT THE
COAST. (THE 22Z RAP PROBABLY HAS THE BEST HANDLE ON WINDS
CURRENTLY)
MY IDEA...BASED PRIMARILY ON THE NAM AND THE PREVIOUS FORECASTER`S
WORK...IS THAT THE BAND OF SUBSTANTIAL SHOWER ACTIVITY NEAR MYRTLE
BEACH WILL HAVE LIMITED SUCCESS WORKING INLAND...AND WILL INSTEAD
PREFERENTIALLY SHIFT NORTHWARD ALONG THE COAST AFFECTING
WILMINGTON AND THE CAPE FEAR AREA AFTER MIDNIGHT. THE ACTIVITY
ACROSS CENTRAL SC WILL MOVE NORTHEASTWARD DROPPING SPOTTIER
RAINFALL...AND DIMINISHING IN COVERAGE BY MIDNIGHT AS LIFT ALONG
THE 305K AND 310K ISENTROPIC SURFACES DIMINISHES.
PLENTY OF CLOUDS AND DEWPOINTS RISING INTO THE 60S WILL HOLD LOWS
IN THE MID 60S FOR MOST LOCATIONS...VIRTUALLY UNCHANGED FROM THE
PREVIOUS FORECAST.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY... FORECAST SOUNDINGS SHOW A DEEP LAYER OF
SATURATION FOR MUCH OF TUESDAY. AND WHILE THE ENTIRE DAY WILL NOT BE
A WASHOUT IT IS QUITE DIFFICULT TO HAVE ANY GIVEN HOUR WITH LOW POPS
DUE TO SEVERAL SMALL SCALE PERTURBATIONS MOVING THROUGH THE FLOW.
GIVEN WIDESPREAD CLOUD COVER MODELS HAVING DIFFICULTY DISCERNING HOW
MUCH INSTABILITY DEVELOPS. REGARDLESS THERE WILL BE ENOUGH FOR
ISOLATED THUNDER BUT BREAKS OR SUFFICIENT THINNING IN CLOUDS COULD
LEAD TO ENOUGH INSTABILITY SUCH THAT SPC HAS REFERENCED NC IN SWODY2.
CHANCE FOR ACTUAL SEVERE WEATHER TOO LOW FOR EVEN A `MARGINAL`
ISOPLETH IN THE OUTLOOK. GIVEN RELATIVELY LOW LCLS/MEAGER LAPSE
RATES FAVORING FAIRLY THIN BUT TALL CAPE AND THE LACK OF ANY DRY
AIR THE MAIN `THREAT` WILL BE NON-SEVERE (20-40MPH) WET
DOWNBURSTS. THE GFS DOES SHOW SOME DRYING AND THE DEVELOPMENT OF
DCAPE BY 00Z DUE TO THE EXIT OF DAY`S STRONGEST SHORTWAVE BUT MUCH
PAST PEAK HEATING THERE MAY NOT BE SUFFICIENT LIFT REMAINING FOR
DEEP CONVECTION. COLD FRONT PUSHES THROUGH DURING THE LATTER HALF
OF TUESDAY NIGHT ENDING MOST IF NOT ALL OF THE LIGHTNING AS LOW
LEVELS STRONGLY STABILIZE UNDERNEATH INVERSION AND LIFT REMAINS
TOO WEAK TO TAP ELEVATED INSTABILITY, IF ANY. LIGHT STRATIFORM
RAIN THEN STAYS IN THE FORECAST FOR MUCH OF WEDNESDAY AS THE
SURFACE WEDGE CONTINUES TO EXPERIENCE WEAK OVERRUNNING. HIGH TEMPS
FROM TUESDAY TO WEDNESDAY WILL GO FROM ROUGHLY 5 DEGREES ABOVE
CLIMO TO ROUGHLY 5 DEGREES BELOW. GIVEN THE STRENGTH OF THE WEDGE
WOULD NOT BE SURPRISED IF WEDNESDAY HIGHS NEED TO BE LOWERED A FEW
DEGREES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...MID LEVEL RIDGING OVER THE WESTERN ATLANTIC AND
GULF OF MEXICO ALONG WITH 5H TROUGHING/CUTOFF OVER THE SOUTHWEST
CONUS WILL SPREAD DEEP MOISTURE OVER THE SOUTHEAST INTO THE START OF
NEXT WEEK. IN ADDITION TO THE DEEP MOISTURE THE SOUTHWEST FLOW ALOFT
WILL ENSURE A STEADY SERIES OF SHORTWAVES EJECTING FROM THE 5H
CUTOFF PASS OVER THE REGION. THESE WAVES MAY WORK TO ENHANCE DIURNAL
CONVECTION...DEPENDING ON THEIR TIMING. TIMING THESE FEATURES IN THE
EXTENDED IS DIFFICULT AT BEST AND GIVEN THE UNCERTAINTY WITH RESPECT
TO AVAILABLE DIURNAL INSTABILITY AS WELL AS THE LOCATION OF ANY
LINGERING CONVECTIVE BOUNDARIES DO NOT PLAN ON ANY MAJOR CHANGES TO
POP FORECAST AT THIS TIME.
TEMPERATURES THU WILL BE NEAR TO BELOW CLIMO WITH HIGH PRESSURE
RIDGING DOWN THE COAST FROM THE NORTHEAST. THE PARENT HIGH MOVES OFF
THE NEW ENGLAND COAST BY FRI...BREAKING THE RIDGE AND ALLOWING
PASSAGE OF WEAK WARM FRONT/COASTAL TROUGH. THIS WILL USHER IN A
PERIOD OF HIGHS AND LOWS ABOVE TO WELL ABOVE CLIMO BUT IS ALSO
LIKELY TO KEEP PRECIP CHANCES ELEVATED THROUGH THE WEEKEND. CUTOFF
EMERGING FROM THE SOUTHWEST THIS WEEKEND WILL HELP DRAG A COLD FRONT
ACROSS THE AREA LATE IN THE PERIOD. STILL SOME UNCERTAINTY WITH
RESPECT TO TIMING BUT GFS IS A BIT FASTER...SUN NIGHT...WHILE THE
ECMWF IS SLOWER...LATER MON.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...LOW VFR CIGS ARE CURRENTLY OCCURRING WITH TEMPO MVFR
CIGS KMYR/KCRE/KFLO. SEVERAL BANDS OF SHOWERS SOUTH OF KMYR ARE
MOVING ONSHORE AND DEVELOPING TOWARDS KFLO. THE AREAS OF SHOWERS
ARE LIFTING SLOWLY NORTH. THERE MODERATE TO HIGH CONFIDENCE
MVFR/SHOWERS WILL OCCUR ACROSS THE KFLO/KMYR/KCRE TERMINALS THIS
AFTERNOON. THE BEST POTENTIAL FOR TEMPO MODERATE TO HEAVY SHOWERS
AND IFR WILL BE AT KCRE/KMYR AS SEA FOG/STRATUS DEVELOPS AS THE
MARINE LAYER BECOMES SATURATED.
LOW CONFIDENCE FORECAST THIS EVENING AND OVERNIGHT. GFS TIME HEIGHTS/MOS
GUIDANCE SUGGESTS/POSSIBLY MVFR...BUT THE NAM MODEL SUGGESTS LIFR/IFR. A
WARM FRONT APPROACHING AND A LOWERING FRONTAL INVERSION SUGGESTS IFR/LIFR.
WILL KEEP TAFS AS THEY ARE AND RE-EVALUATE ON NEXT TAF PACKAGE. THE WARM
FRONT WILL MOVE S-N SHIFTING WINDS TO LIGHT SW BY MORNING. CIGS SHOULD
IMPROVE TO MVFR AFTER SUNRISE.
EXTENDED OUTLOOK...TUES AND WED...A CHANCE OF SHOWERS/IFR EARLY WITH CIGS
BECOMING MVFR WITH A CHANCE OF THUNDERSTORMS EACH DAY. MVFR/SHOWERS THURS
THROUGH FRI. VFR SAT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM MONDAY...A COASTAL TROUGH IS HELPING TO KEEP WIND
DIRECTIONS BACKED AROUND TO THE EAST AND NORTHEAST ALONG THE
COAST...WHILE FARTHER OFFSHORE AT THE FRYING PAN SHOALS BUOY AND
THE EDISTO BUOY WINDS HAVE ALREADY SWUNG AROUND TO THE SOUTHEAST.
THIS BOUNDARY SHOULD LIFT NORTHWARD ALMOST LIKE A WEAK WARM FRONT
TONIGHT...ALLOWING WINDS EVEN AT THE BEACHES TO ASSUME A MORE
SOUTHERLY DIRECTION BY DAYBREAK TUESDAY.
AN AREA OF SUBSTANTIAL SHOWER ACTIVITY NEAR MYRTLE BEACH SHOULD
GRADUALLY LIFT NORTH ALONG THE COAST TONIGHT...REACHING CAPE FEAR
BY MIDNIGHT. SEAS CURRENTLY 3-5 FEET SHOULD MAINTAIN THEMSELVES
WITH A STEADY ONSHORE WIND EXPECTED TO CONTINUE.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY... SOUTH TO SOUTHWESTERLY FLOW ON TUESDAY IN A
PREFRONTAL FLOW REGIME AS BOUNDARY APPROACHES FROM THE NORTHWEST.
NEITHER WINDS NOR SEAS WILL BE PARTICULARLY STIRRED UP SO THE MAIN
THREAT TO MARINERS WILL BE THE FACT THAT SOME SHOWERS AND STORMS
COULD PRODUCE HEAVY ENOUGH RAINFALL FOR SOME VISIBILITY
RESTRICTIONS IN ADDITION TO SOME FAIRLY GUSTY (30-40KT) WINDS.
LATE NIGHT FROPA MAY CHANGE THAT HOWEVER AS A WEDGE OF HIGH
PRESSURE STARTS GETTING ESTABLISHED OVER LAND. AS THIS FEATURE
STRENGTHENS IN PART DUE TO RAIN FALLING INTO IT THE GRADIENT AND
RESULTING WIND/SEAS WILL RISE. AN ADVISORY WILL BE HOISTED AT SOME
POINT THOUGH ACTUAL ADVISORY CONDITIONS/6FT SEAS LIKELY NOT
MATERIALIZING TIL NIGHTTIME.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...PINCHED GRADIENT BETWEEN HIGH RIDGING IN FROM
THE NORTH AND COASTAL TROUGH WILL MAINTAIN NORTHEAST FLOW IN THE
20 TO 25 KT RANGE THU AND THU NIGHT. EXTENDED PERIOD OF INCREASED
NORTHEAST FLOW WILL KEEP SEAS OVER 6 FT ACROSS MUCH OF THE WATERS
AND HEADLINES ARE LIKELY TO BE CARRIED OVER FROM THE SHORT TERM
PERIOD. GRADIENT WEAKENS FRI AS THE HIGH SHIFTS EAST AS TROUGH
MOVES ONSHORE/LIFTS NORTH. AS THIS OCCURS WINDS WILL SHIFT FROM
NORTHEAST THU NIGHT TO EAST LATER FRI WITH SOUTHWEST FLOW
DEVELOPING LAT FRI NIGHT AND CONTINUING ON SAT. WEAKER GRADIENT
FRI AND SAT WILL KEEP SPEEDS GENERALLY 10 KT OR LESS WITH SEAS
DECREASING FROM 3 TO 5 FT FRI MORNING TO 2 TO 3 FT SAT AFTERNOON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...TRA/RGZ
SHORT TERM...MBB
LONG TERM...III
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
310 PM CDT SUN APR 12 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 255 PM CDT SUN APR 12 2015
COLD FRONT ENTERING ERN FCST AREA ATTM NR A
WARROAD...BAGLEY...TO ELBOW LAKE LINE. SATELLITE SHOWS SOME BEST
CU DEVELOPMENT JUST EAST OF FCST AREA FROM NORTH OF AITKIN MN
THROUGH BRAINERD TO BENSON MN THEN INTO WATERTOWN AREA OF SD. THUS
ANY CONVECTION MAY INDEED FIRE EAST OF THE FCST AREA. WILL WAIT
AND SEE IF WORTH PULLING POPS IN FAR EASTERN FCST AREA FOR NEXT
FEW HOURS.
OTHERWISE SHORT WAVE TROUGH OVER SASKATCHEWAN WITH VORT MAX OVER
NW/NCNTRL ND. LEADING EDGE OF THIS SYSTEM PRODUCING A NARROW BAND
OF SHOWERS. 0.02 OCCURRED IN DEVILS LAKE. HRRR CONTINUES TO HAVE A
FEW SHOWERS MOVING EAST- NORTHEAST BUT WEAKENING A BIT. WILL
MAINTAIN ISOLD -SHRA WORDING THRU 00Z- 01Z IN NRN VALLEY.
WINDS WILL DIMINISH THIS EVENING. THE COLD AIR ALOFT ASSOC WITH
500 MB TROUGH DEVELOPING A FEW SHOWERS IN WRN ND INTO SRN SASK/NE
MONTANA. FEEL THESE ARE HEAT DRIVEN AND WILL DISSIPATE THIS EVE.
THUS FOR THE TIME BEING KEPT POPS OUT OF DVL BASIN THOUGH NAM DOES
HAVE A FEW SHOWERS PSBL INTO NE ND THIS EVE WITH THE COLD POOL
ALOFT.
COLD POOL ALOFT WILL MOVE INTO NW MN MONDAY MORNING AND OVER NORTH
CENTRAL MINNESOTA AND LAKE OF THE WOODS ONTARIO REGION MIDDAY-EARL
AFTN MONDAY. VIA DLH CHAT...WILL INCLUDE A LOW POP FOR SUN DRIVEN
SHOWERS IN LAKE OF THE WOODS-RED LAKE REGION IN THE 17Z-22Z
PERIOD. OTHERWISE SOME CUMULUS LIKELY BUT A GOOD DEAL OF SUN TOO.
QUITE WINDY ON MONDAY WITH WEST WINDS AND VERY DRY AIRMASS MOVING.
THIS CAUSES FIRE WEATHER CONCERNS WHICH ARE ADDRESSED IN FIRE
WEATHER DISCUSSION SECTION. WINDS MAY WELL BE IN ADVISORY CRITERIA
FOR A TIME ESP DVL BASIN. WILL ALLOW MID SHIFT TO SORT OUT ANY
FIRE/WIND HEADLINES. FOR THE AFTN WINDS IN THE GRIDS DID GO WITH
HIGHER MAV MOS WINDS VS MODEL SUPERBLEND.
WINDS DIMINISH QUICKLY MON EVE AS HIGH PRESSURE RIDGE STARTS TO
MOVE IN. SKIES WILL BE CLEAR MONDAY NIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 255 PM CDT SUN APR 12 2015
HIGH PRESSURE WILL MOVE EAST ON TUESDAY WITH RETURN SOUTH-
SOUTHEAST WIND FLOW SETTING UP OVER ERN ND. TEMPS WILL WARM INTO
THE MID TO UPPER 70S IN THE RRV/ERN ND AS WARMING OCCURS IN THE
SFC-850 MB LEVEL OUT AHEAD OF NEXT SYSTEM ENTERING THE HIGH
PLAINS. DEW PTS MAY BE HIGHER BUT WITH HIGHER TEMPS EXPECT A DAY
WITH LOW RH VALUES ONCE AGAIN AND LIKELY CRITICAL FIRE WX
CONDITIONS. TUES NIGHT WILL SEE LOW LEVEL JET OVER THE AREA AND A
MILD NIGHT. WEDNESDAY WILL BE DRY. MODELS HAVE SLOWED SYSTEM DOWN
AND CONTINUED WITH IDEA OF A PRETTY MOISTURE STARVED SYSTEM. ANY
PRECIP CONFINED TO JUST BEHIND THE FRONT WHICH WILL BE MORE WED NIGHT.
FOR WEDNESDAY NIGHT THROUGH SATURDAY...ZONAL UPPER FLOW PATTERN
OVER SRN CANADA WILL BRING A MINOR SHORT WAVE AND ASSOCIATED SFC
TROUGH ACROSS MAINLY NORTHERN HALF OF CWA AND SRN MB EARLY IN THE
PERIOD. THIS WILL BRING A CHANCE FOR SCT SHRA WED NIGHT. MODELS IN
DECENT AGREEMENT WITH THIS FEATURE ALTHOUGH GFS A TAD FURTHER
NORTH. NEXT WAVE WILL MOVE ACROSS SRN CANADA ON FRIDAY AND BRING A
CHANCE FOR MORE LIGHT SHOWERS ALONG INTL BORDER...HOWEVER NOT MUCH
MOISTURE AS FLUX OF PACIFIC MOISTURE REMAINS NORTH AND CONVECTION
OVER SRN US CUTS OFF ANY GULF MOISTURE. SW RIDGE DEVELOPING OVER
SASK/MB WILL AND SFC HIGH OVER NORTHERN TIER WILL KEEP FRI NIGHT
INTO SAT DRY. CONSIDERABLE DIFFERENCE ON LATITUDE OF NEXT WAVE
MOVING ACROSS SRN CANADA...WITH GFS MOVING ACROSS NORTHERN MB AND
KEEPING CWA DRY WHEREAS ECMWF BRINGS SFC LOW ALONG INTL BORDER.
ALL BLEND REPRESENTING ECMWF POSSIBILITY AND YIELDING CHANCE POPS
FOR SAT NIGHT INTO SUN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1238 PM CDT SUN APR 12 2015
SFC TROUGH HAS MOVED MOVING THROUGH THE RRV AT TIME OF TAF
ISSUANCE...WITH WINDS SHIFTING TO NW AT GFK AND SW BECMG NW AT FAR
OVER NEXT 45 MIN TO HOUR. WINDS IN THE DVL REGION EXPECTED TO BECOME
QUITE WINDY FROM WNW BY MID AFTN...SUBSIDING SOME OVERNIGHT. EXPECT
WINDS TO SHIFT TO NW AT TVF/BJI BY MID AFTN.
&&
.FIRE WEATHER...
ISSUED AT 255 PM CDT SUN APR 12 2015
NEAR CRITICAL FIRE WEATHER CONDITIONS WILL PERSIST THROUGH LATE THIS
AFTERNOON OVER PARTS OF MAINLY SE ND/S RRV AS WEST OR NORTHWEST WINDS
GUST AT TIMES UP TO 30 MPH AMIDST DRY SURFACE AIR BEHIND A COLD
FRONT. THE FIRE WEATHER CONCERNS WILL CONTINUE THROUGH THE START OF
THE WEEK. A FIRE WEATHER WATCH HAS BEEN ISSUED FOR MONDAY AFTERNOON
FOR THE ENTIRE REGION. A DEEPENING MIXED BOUNDARY LAYER UP TO NEAR
700 MB WILL HELP TRANSFER HIGHER WIND GUSTS (UP TO 40 MPH) DOWN TO
THE SURFACE...WITH SUSTAINED WINDS 20 TO 30 MPH. WITH THE AID OF THE
DEEP VERTICAL MIXING AND AN ALREADY DRY AIR MASS IN PLACE...RH
SHOULD FALL TO 20 PERCENT OR LOWER IN MANY AREAS. GIVEN THAT FUELS
REMAIN VERY DRY...THIS COMBINATION OF FACTORS MAY LEAD TO CRITICAL
FIRE WEATHER CONDITIONS ON MONDAY.
ANOTHER CRITICAL FIRE WEATHER DAY IS POSSIBLE ON TUESDAY. A SFC
PRESSURE GRADIENT WILL TIGHTEN AS LOW PRESSURE DEVELOPS OVER THE
HIGH PLAINS. THIS WILL LEAD TO BREEZY/GUSTY SOUTHERLY WINDS. WITH
WARMER TEMPS...RH MAY FALL BELOW 20 PERCENT AGAIN.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR NDZ006>008-014>016-024-026>030-038-039-049-052>054.
MN...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR MNZ001>009-013>017-022>024-027>032-040.
&&
$$
SHORT TERM...RIDDLE
LONG TERM...RIDDLE/SPEICHER
AVIATION...RIDDLE
FIRE WEATHER...MAKOWSKI
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1148 PM CDT SAT APR 11 2015
.UPDATE...
ISSUED AT 1147 PM CDT SAT APR 11 2015
LOW LEVEL MOISTURE IS EXPECTED TO MOVE NORTH TONIGHT AND
SUN...MOSTLY OVER THE MN SIDE OF THE RED RIVER. PRECIPITABLE WATER
RISES TO AROUND THREE QUARTERS OF AN INCH BY 12Z SUN. MAY PRODUCE
SOME LOWER CLOUDS..THOUGH MOSTLY VFR CATEGORY...OVER THE FAR EASTERN
ZONES SUN. TWEAKED LOW TEMPS DOWN A BIT OVER MAINLY EASTERN ND FOR
TONIGHT.
UPDATE ISSUED AT 1002 PM CDT SAT APR 11 2015
SATELLITE SHOWING MID LEVEL CLOUDS IN WESTERN ND WAS SHIFTING EAST.
TWEAKED LOW TEMPS DOWN A BIT OVER PARTS OF EASTERN ND AS TEMPS WERE
FALLING AT A GOOD CLIP THIS EVENING. NO OTHER CHANGES MADE.
UPDATE ISSUED AT 657 PM CDT SAT APR 11 2015
WILL CHECK OVER DIURNAL CURVE AND PROBABLY SLOW DOWN HOURLY TEMPS
FALLS FOR TONIGHT. ALSO WILL TWEAK WINDS. OTHERWISE NO OTHER CHANGES
AT THIS UPDATE.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 343 PM CDT SAT APR 11 2015
FORECAST CHALLENGE FOR SHORT TERM WILL BE OVERNIGHT LOWS AND
POTENTIAL FOR SOME WEAK CONVECTION SUNDAY AFTN. FOR IMMEDIATE
SHORT TERM...HI RES MODELS HAVE DONE DECENT JOB HANDLING TODAYS
HOURLY TEMPS...WITH 8 AM RUC RUN VERIFYING FAIRLY WELL WITH 3 PM
OBSERVED TEMPS. HOWEVER...THIS HAS ONLY BEEN THE CASE IN REGIONS
ACROSS THE SOUTHERN VALLEY WHERE DAYTIME MIXING HAS BEEN THE
HIGHEST. THEREFORE USING RUC AS A STARTING POINT FOR TEMPS THROUGH
03Z...BUT NEEDING TO COOL OFF THE FAR EAST AND WEST WHERE WINDS
ARE SLIGHTLY LESS. USED A FCST BLENDS FOR LOW POPS TOMORROW AFTN.
TONIGHT...A SIGNIFICANT LLJ WILL DEVELOP...WITH H850 WINDS AROUND
50 KTS OVER N CNTRL MN BY 03Z. THIS WILL KEEP TEMPS UP WELL INTO
THE EVENING FOR THE SOUTHERN VALLEY AND SOUTHEASTERN ZONES...AND
USING RUC HOURLY TEMPS FOR THESE REGIONS. OVERNIGHT LOWS IN
SOUTHERN VALLEY MAY STAY IN THE MID 50S WITH SOME MIXING
CONTINUING THROUGHOUT THE NIGHT. TOUGHER AREA TO FCST WILL BE
SOUTHEAST WHERE DAYTIME HIGHS WERE SIGNIFICANTLY COOLER HOWEVER
THE AXIS OF THE LLJ WILL SHIFT OVER THAT AREA...WHEN THE LLJ
STRENGTHENS...IN THE EARLY EVENING HOURS. ALSO POTENTIAL FOR SOME
SHOWERS/CONVECTION TO DEVELOP IN THE EAST TOWARD MORNING.
MEANWHILE BY EARLY MORNING WE WILL SEE SOME INCREASE IN SKY IN THE
NORTHWEST AS MID CLOUDS NOW OVER MT ADVECT EAST...WITH SOME SHRA
DEVELOPING OVERNIGHT IN CNTRL ND.
TOMORROW...WILL SEE MORE SHRA AND POSSIBLY TSRA DEVELOP OVER N
CNTRL MN BUT THE BEST THREAT FOR ANY HELPFUL RAINFALL AMOUNTS WILL
BE EAST OF THE CWA. APPROACHING FROM FROM THE WEST MAY PRODUCE
SOME RAINFALL SHOWERS MAINLY ALONG AND NORTH OF HWY 2...WITH SOME
COOLER TEMPS ADVECTING IN DURING THE DAY. MAX TEMPS IN THE VALLEY
AND ADJACENT COUNTIES IN MN MAY OCCUR IN THE EARLY AFTN AND REMAIN
STEADY OF FALL SLIGHTLY IN THE AFTN. COOLER AND DRIER AIRMASS
SHOULD BE IN PLACE ACROSS ENTIRE CWA BY 00Z MON.
TOMORROW NIGHT...COOLER AIRMASS WILL BRING OVERNIGHT LOWS DOWN
INTO THE 30S...WITH OVERNIGHT LOWS NEAR ZERO IN THE FAR NORTHWEST
AND AROUND LAKE OF THE WOODS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 343 PM CDT SAT APR 11 2015
MONDAY WILL BE DRY WITH DAYTIME HIGHS AROUND 60. BREEZY WESTERLY
WINDS WILL SUBSIDE OVERNIGHT...WITH STRONG SOUTHERLY WINDS
DEVELOPING TUESDAY. TUESDAY WILL SEE A RETURN OF WARM
WEATHER...WITH HIGHS IN THE 70S FOR MUCH OF THE AREA.
FOR TUESDAY NIGHT THROUGH SATURDAY...MODELS CONTINUE TO DIFFER IN
HOW MUCH SOUTHERN STREAM MOISTURE WILL GET DRAWN NORTHWARD AHEAD OF
FRONTS MOVING EASTWARD THROUGH SOUTHERN CANADA AND THE NRN TIER OF
THE U.S. 12Z ECMWF IS VERY MUCH SPLIT FLOW AND KEEPS THE SRN STREAM
MOISTURE WELL TO OUR SOUTH UNTIL SYSTEM MOVES TO OUR EAST OVER THE
GREAT LAKES REGION. 12Z GFS/GEM REMAINS A BIT WETTER WITH FRONT
MOVING THROUGH WED AFTN-EVE. WILL MAINTAIN THE CHC POPS FOR
SHOWERS. NEXT SYSTEM TO MOVE EAST WILL COME LATE SATURDAY...WHICH
WILL THE SAME MOISTURE ISSUES THAN THE MID WEEK ONE WILL HAVE. LOOK
FOR SLIGHTLY COOLER AIRMASS OVER THE AREA...BUT STILL 5-10 DEGREES
ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1147 PM CDT SAT APR 11 2015
FOG LOOP AND SURFACE OBS INDICATE MID AND HIGH CLOUDS WERE MOVING INTO
EASTERN ND. SCT CIRRUS WAS OVER NORTHWEST MN. EXPECT MOSTLY MID
LEVEL CLOUD WITH CIGS AROUND 10 TO 12 THOUSAND FT TO MOVE INTO THE
AREA FOR THE REST OF THE NIGHT. WIND SHIFT AND COLD FRONT EXPECTED
TO MOVE THROUGH THE FORECAST AREA LATE TONIGHT AND SUN. EXPECT MOSTLY
VFR CONDITIONS FOR TONIGHT AND SUN.
&&
.FIRE WEATHER...
ISSUED AT 343 PM CDT SAT APR 11 2015
GUSTY SOUTHERLY WINDS AND LOW RH WILL LEAD TO CONTINUED CRITICAL
FIRE WEATHER CONDITIONS THROUGH LATE AFTERNOON OVER MUCH OF THE
REGION. A COLD FRONT WILL SWING THROUGH ON SUNDAY...WITH WINDS
BECOMING GUSTY FROM THE WEST IN ITS WAKE. WHILE TEMPS WILL BE
SOMEWHAT COOLER ON SUNDAY...DEEP MIXING WILL RESULT IN LOW RH
VALUES...LOWEST WEST OF THE VALLEY. NEAR CRITICAL CONDITIONS ARE
POSSIBLE ESPECIALLY OVER SE ND...BUT THIS WILL DEPEND ON CLOUD AND
TEMP TRENDS. RH MAY BE SOMEWHAT HIGHER FARTHER EAST WHERE THE
FRONTAL PASSAGE WILL OCCUR LATER. FIRE WEATHER CONCERNS WILL
CONTINUE INTO THE START OF THE WEEK...WITH GUSTY WEST WINDS AND VERY
DRY AIR (RH NEAR OR UNDER 20 PERCENT) POSSIBLY LEADING TO CRITICAL
CONDITIONS FOR MONDAY. TUESDAY MAY BE ANOTHER CRITICAL OR NEAR
CRITICAL FIRE WEATHER DAY.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...HOPPES
SHORT TERM...SPEICHER
LONG TERM...RIDDLE/SPEICHER
AVIATION...HOPPES
FIRE WEATHER...MAKOWSKI
AREA FORECAST DISCUSSION
NWS MEDFORD OR
742 PM PDT MON APR 13 2015
.UPDATED FOR SNOW ACCUMULATION WORDING IN CASCADES.
.DISCUSSION...A COLD FRONT IS MOVING THROUGH THE FORECAST
AREA...DROPPING TEMPERATURES BY 10 DEGREES IN LESS THAN AN HOUR AS
IT MOVES THROUGH. FEELING A SHARP TEMPERATURE CHANGE WITH A COLD
FRONT AS IT MOVES THROUGH IS NOT THAT COMMON IN THE VALLEYS OF
SOUTHERN OREGON OR NORTHERN CALIFORNIA...BUT TONIGHT`S FRONT WILL
DROP SNOW LEVELS SIGNIFICANTLY OVERNIGHT. BASED ON CURRENT
OBSERVATIONS AND THE NAM VERIFYING PRETTY WELL...HAVE BROUGHT
SNOW LEVELS DOWN TO NEAR 2000 FEET WEST OF THE CASCADES TONIGHT.
LATEST HRRR RUNS...IN COMBINATION WITH CURRENT SATELLITE
IMAGERY...ROAD SURFACE TEMPERATURES...AND METRO ROAD SURFACE
TEMPERATURE FORECASTS...SUGGEST THAT IMPACTS FROM THIS SNOWFALL
WILL BE MINIMAL. SOME SNOW WILL LIKELY FALL OVER SEXTON PASS AND
SISKIYOU SUMMIT ON INTERSTATE 5 THIS EVENING...BUT MOST SNOWFALL
SHOULD MELT ON THE ROADS AND LOWERED VISIBILITY SHOULD BE THE MOST
SIGNIFICANT IMPACT...SO DRIVERS SHOULD BE PREPARED AND OF COURSE
SLOW DOWN DURING ANY SNOW SHOWERS.
IN THE CASCADE PASSES...TEMPERATURES ARE JUST DROPPING TO FREEZING
AT DIAMOND LAKE WITH WET ROADS PER WEBCAMS. SIMILAR TO PREVIOUS
FORECAST THOUGHTS...LATEST MODELS SUGGEST A FEW INCHES OF
ACCUMULATION POSSIBLE AT AREAS LIKE DIAMOND LAKE...AND ROADS COULD
BECOME SLIPPERY LATER TONIGHT AS ROAD TEMPERATURES COOL TO NEAR
FREEZING. TRAVELERS SHOULD USE EXTRA CAUTION IF TRAVELING IN THE
CASCADES OVERNIGHT.
ADDITIONALLY...THE FRONT HAS BROUGHT GUSTY WINDS TO THE AREA...AND
HAVE ISSUED A WIND ADVISORY THROUGH THE EVENING FOR JACKSON COUNTY
WITH GUSTS TO 45 MPH.
LAST BUT NOT LEAST...GIVEN RECENT LIGHTNING STRIKES AND THE
PROGRESSION OF THE COLD POOL ALOFT...WE THINK OVERNIGHT THUNDERSTORMS
ARE POSSIBLE FROM GRANTS PASS NORTHWEST INTO JOSEPHINE...CURRY...COOS...AND
DOUGLAS COUNTIES.
SHOWERS ARE STILL POSSIBLE TOMORROW IN A WEAKLY UNSTABLE AIR MASS.
PLEASE SEE THE PREVIOUS DISCUSSION BELOW FOR DETAILS ON A RETURN
TO TO WARMER AND DRIER CONDITIONS LATER IN THE WEEK.
&&
.AVIATION...FOR THE 14/00Z TAF CYCLE...A COLD FRONT WILL PASS
THROUGH OUR CWA THIS EVENING BRINGING RAIN SHOWERS AND MVFR CIGS
FOR THE UMPQUA BASIN AND NEAR THE COAST. LOOK FOR THE COLD FRONT
TO CREATE A WELL MIXED LAYER AND INSTABILITY NEAR THE COAST.
THEREFORE THUNDERSTORMS ARE POSSIBLE OFF THE COAST OF COOS AND
CURRY COUNTY THIS EVENING...AND INTO PARTS OF JOSEPHINE AND
DOUGLAS COUNTIES. THE COLD FRONT WILL MOVE THROUGH KLMT TONIGHT
WITH WINDS 20-25KT AND GUSTS TO 30-35 KTS. SOME UNCERTAINTY WITH
THE CLOUD DECKS TONIGHT WITH COLD SINKING AIR MOVING IN BEHIND THE
FRONT. MODELS STILL SUGGEST CIGS IN MVFR SO KEPT THIS IN MOST OF
THE TAFS THIS EVENING AND INTO TONIGHT. SPILDE/SMITH
&&
.MARINE...UPDATED 300 PM PDT MONDAY APR 13 2015...A FRONT MOVED
ONSHORE THIS AFTERNOON...AND WINDS HAVE TURNED NORTHWEST BEHIND
THE FRONT...DECREASING THIS EVENING. THUNDERSTORMS ARE POSSIBLE
OVERNIGHT. STEEP SEAS AND SHOWERS WILL CONTINUE THROUGH TUESDAY.
A THERMAL TROUGH WILL DEVELOP WEDNESDAY AND THURSDAY WITH
INCREASING NORTH WINDS AND SEAS. THERE IS THE POTENTIAL FOR GALES
SOUTH OF CAPE BLANCO. THERE WAS SOME DISAGREEMENT WITH THE MODELS
ON WINDS WEDNESDAY EVENING SO STAYED AWAY FROM A GALE WATCH FOR
WEDNESDAY EVENING. THEN MODERATE WEST TO NORTHWEST SWELL WITH VERY
LONG PERIOD WILL ALSO ENTER THE REGION THURSDAY AND THEN LOWER ON
FRIDAY. NORTH WINDS MAY LOWER BRIEFLY ON FRIDAY BEFORE
STRENGTHENING AGAIN THIS WEEKEND. /SMITH
&&
.PREV DISCUSSION... /ISSUED 522 PM PDT MON APR 13 2015/
SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT.
THE MAIN ITEMS OF INTEREST IN THE SHORT TERM ARE GUSTY WINDS
TONIGHT (STRONGEST ON THE EAST SIDE), RAIN AND SNOW WITH FALLING
SNOW LEVELS TONIGHT, A SLIGHT CHANCE OF COASTAL THUNDERSTORMS
LATE THIS EVENING INTO EARLY TUESDAY MORNING, SHOWERS AND SNOW
SHOWERS LATE TONIGHT INTO TUESDAY EVENING, AND COLD MORNING LOW
TEMPERATURES.
THERE WAS LITTLE ADJUSTMENT NEEDED TO THE FORECAST FOR TONIGHT.
A FAST MOVING COLD FRONT IS NOW REACHING THE COAST. WESTERLY
WINDS THIS AFTERNOON HAVE INCREASED TO RIGHT AROUND THE EXPECTED
STRENGTH. THE 12Z GFS MOS WIND SPEEDS WERE FORECAST TO BE SLIGHTLY
STRONGER THAN THE NAM MOS, AND ARE VERIFYING WELL AT THIS TIME
WITH WIDESPREAD REPORTS OF GUSTY, BREEZY 15 TO 25 MPH
WINDS...INCLUDING GUSTS OF 43 MPH AT SUMMER LAKE.
SNOW LEVELS WILL DROP QUICKLY FROM AROUND 6000 TO 7000 FEET THIS
AFTERNOON TO AROUND 2500 TO 3000 FEET BY THE TIME PRECIPITATION
TAPERS TO LIGHT SHOWERS LATE TONIGHT. THE BULK OF COASTAL RAIN
WILL FALL FROM NOW THROUGH THE EARLY EVENING, MAINLY AN EVENING
EVENT FOR THE WEST SIDE, AND A LATE NIGHT EVENT FOR THE EAST SIDE.
SNOWFALL OF 2 TO 5 INCHES IS EXPECTED AROUND CRATER LAKE WITH 1 TO
2 INCHES FOR MUCH OF THE CASCADES, AND GENERALLY LESS THAN AN INCH
OF SNOW ON THE EAST SIDE.
THE SLIGHT CHANCE OF COASTAL THUNDERSTORMS WILL ARISE FROM A
POST-FRONTAL SURFACE TROUGH THAT WILL HAVE ITS LANDFALL COINCIDE
WITH THE AXIS OF THE UPPER LEVEL TROUGH/COLDEST AIR ALOFT MOVING
INLAND. I MENTIONED IT IN YESTERDAY`S DISCUSSION AND IT BEARS
REPEATING THAT THE WEATHER ON TUESDAY WILL HAVE A RESEMBLANCE TO
WHAT OCCURRED ON SATURDAY. A COLD, WEAKLY UNSTABLE NORTHWEST FLOW
ALOFT WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS AND SNOW SHOWERS
THAT WILL FALL OUT OF LOW TOPPED CUMULUS CLOUDS. THE SNOW LEVEL ON
TUESDAY WILL RISE FROM AROUND 2500 FEET TO AROUND 3500 FEET WITH
AN ADDITIONAL INCH OF SNOW POSSIBLE IN THE CASCADES EXCEPT LIKELY
A BIT MORE (AROUND 2 INCHES) FOR CRATER LAKE.
VALLEY LOW CLOUDS AND PATCHY FOG ARE LIKELY TO HINDER COOLING
DURING EACH OF THE NEXT TWO NIGHTS, BUT IT WILL STILL BE QUITE
COLD ANYWAY WITH LOWS SEVERAL DEGREES BELOW NORMAL.
HIGH PRESSURE CENTERED OFFSHORE FROM CALIFORNIA WILL BUILD INTO
THE WEST COAST AND BRING A RETURN OF MOSTLY CLEAR TO CLEAR SKIES
WITH A WARMING TREND WEDNESDAY THROUGH THURSDAY.
LONG TERM...FRIDAY THROUGH MONDAY.
WARM AND DRY CONDITIONS WILL PERSIST THROUGH THE WEEKEND AS A
STRONG LONG WAVE RIDGE SETTLES JUST OFF THE WEST COAST WITH
NORTHERLY FLOW ALOFT AND LOW LEVEL OFFSHORE FLOW. A SHORT WAVE
TROUGH IS FORECAST TO MOVE ACROSS WASHINGTON AND NORTHERN OREGON
ON FRIDAY. THE MAIN EFFECT FROM THIS FEATURE IS TO PUSH HIGH
TEMPERATURES DOWN A FEW DEGREES ALTHOUGH IT WILL STILL BE ABOVE
SEASONAL NORMS. WE MAY ALSO SEE A SLIGHT INCREASE IN THE SURFACE
WESTERLY WINDS. THE GFS SHOWS SOME INSTABILITY IN TERMS OF THE
LIFTED INDEX BUT WESTERLY FLOW IS GENERALLY NOT FAVORABLE FOR
THUNDERSTORMS AND MOISTURE WILL BE VERY LIMITED.
ON SATURDAY THE LONG WAVE RIDGE REBUILDS WESTWARD TO AROUND
LONGITUDE 130W ALLOWING THE SHORT WAVE TROUGH TO DROP SOUTH ACROSS
OUR FORECAST AREA IN THE NORTH TO NORTHWEST FLOW ALOFT. THERE
SEEMS TO BE MORE INSTABILITY ACROSS OUR NORTHERN CALIFORNIA ZONE
SOUTHWARD. AT THIS POINT WE FEEL THAT THIS WOULD TRANSLATE INTO
MORE CUMULUS BUILDUPS OVER THE SISKIYOUS AND THE MARBLE MOUNTAINS
ON SATURDAY. THE RIDGE CONTINUES TO BUILD INTO THE WEST COAST
SUNDAY AND MONDAY. DURING THE PAST 10 RUNS THE GFS TREND HAS BEEN
TO FORECAST HIGHER 500 MB HEIGHT OVER THE PACIFIC NORTHWEST SO
CONFIDENCE IS HIGH THAT WE WILL SEE A WARM AND DRY TREND. HIGHS
IN THE ROGUE VALLEY ARE FORECAST TO BE IN THE LOWER 80S FROM
FRIDAY THROUGH MONDAY (WITH THE EXCEPTION OF SATURDAY DUE TO CLOUD
COVER). IF THIS SCENARIO HOLDS TRUE, THIS IS ALMOST 20 DEGREES
ABOVE SEASONAL NORMS FOR MID APRIL FOR THE ROGUE VALLEY AND ABOUT
15 DEGREES ABOVE NORMAL FOR AREAS EAST OF THE CASCADES. /FB
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 11 PM PDT THIS EVENING FOR ORZ026-620>623.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 PM PDT THIS EVENING FOR
PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT TUESDAY
FOR PZZ350-356.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT TUESDAY
FOR PZZ370-376.
$$
NSK/FJB/MAS
AREA FORECAST DISCUSSION
NWS MEDFORD OR
724 PM PDT MON APR 13 2015
.DISCUSSION...A COLD FRONT IS MOVING THROUGH THE FORECAST
AREA...DROPPING TEMPERATURES BY 10 DEGREES IN LESS THAN AN HOUR AS
IT MOVES THROUGH. FEELING A SHARP TEMPERATURE CHANGE WITH A COLD
FRONT AS IT MOVES THROUGH IS NOT THAT COMMON IN THE VALLEYS OF
SOUTHERN OREGON OR NORTHERN CALIFORNIA...BUT TONIGHT`S FRONT WILL
DROP SNOW LEVELS SIGNIFICANTLY OVERNIGHT. BASED ON CURRENT
OBSERVATIONS AND THE NAM VERIFYING PRETTY WELL...HAVE BROUGHT
SNOW LEVELS DOWN TO NEAR 2000 FEET WEST OF THE CASCADES TONIGHT.
LATEST HRRR RUNS...IN COMBINATION WITH CURRENT SATELLITE
IMAGERY...ROAD SURFACE TEMPERATURES...AND METRO ROAD SURFACE
TEMPERATURE FORECASTS...SUGGEST THAT IMPACTS FROM THIS SNOWFALL
WILL BE MINIMAL. SOME SNOW WILL LIKELY FALL OVER SEXTON PASS AND
SISKIYOU SUMMIT ON INTERSTATE 5 THIS EVENING...BUT MOST SNOWFALL
SHOULD MELT ON THE ROADS AND LOWERED VISIBILITY SHOULD BE THE MOST
SIGNIFICANT IMPACT...SO DRIVERS SHOULD BE PREPARED AND OF COURSE
SLOW DOWN DURING ANY SNOW SHOWERS.
ADDITIONALLY...THE FRONT HAS BROUGHT GUSTY WINDS TO THE AREA...AND
HAVE ISSUED A WIND ADVISORY THROUGH THE EVENING FOR JACKSON COUNTY
WITH GUSTS TO 45 MPH.
LAST BUT NOT LEAST...GIVEN RECENT LIGHTNING STRIKES AND THE
PROGRESSION OF THE COLD POOL ALOFT...WE THINK OVERNIGHT THUNDERSTORMS
ARE POSSIBLE FROM GRANTS PASS NORTHWEST INTO JOSEPHINE...CURRY...COOS...AND
DOUGLAS COUNTIES.
SHOWERS ARE STILL POSSIBLE TOMORROW IN A WEAKLY UNSTABLE AIR MASS.
PLEASE SEE THE PREVIOUS DISCUSSION BELOW FOR DETAILS ON A RETURN
TO TO WARMER AND DRIER CONDITIONS LATER IN THE WEEK.
&&
.AVIATION...FOR THE 14/00Z TAF CYCLE...A COLD FRONT WILL PASS
THROUGH OUR CWA THIS EVENING BRINGING RAIN SHOWERS AND MVFR CIGS
FOR THE UMPQUA BASIN AND NEAR THE COAST. LOOK FOR THE COLD FRONT
TO CREATE A WELL MIXED LAYER AND INSTABILITY NEAR THE COAST.
THEREFORE THUNDERSTORMS ARE POSSIBLE OFF THE COAST OF COOS AND
CURRY COUNTY THIS EVENING...AND INTO PARTS OF JOSEPHINE AND
DOUGLAS COUNTIES. THE COLD FRONT WILL MOVE THROUGH KLMT TONIGHT
WITH WINDS 20-25KT AND GUSTS TO 30-35 KTS. SOME UNCERTAINTY WITH
THE CLOUD DECKS TONIGHT WITH COLD SINKING AIR MOVING IN BEHIND THE
FRONT. MODELS STILL SUGGEST CIGS IN MVFR SO KEPT THIS IN MOST OF
THE TAFS THIS EVENING AND INTO TONIGHT. SPILDE/SMITH
&&
.MARINE...UPDATED 300 PM PDT MONDAY APR 13 2015...A FRONT MOVED
ONSHORE THIS AFTERNOON...AND WINDS HAVE TURNED NORTHWEST BEHIND
THE FRONT...DECREASING THIS EVENING. THUNDERSTORMS ARE POSSIBLE
OVERNIGHT. STEEP SEAS AND SHOWERS WILL CONTINUE THROUGH TUESDAY.
A THERMAL TROUGH WILL DEVELOP WEDNESDAY AND THURSDAY WITH
INCREASING NORTH WINDS AND SEAS. THERE IS THE POTENTIAL FOR GALES
SOUTH OF CAPE BLANCO. THERE WAS SOME DISAGREEMENT WITH THE MODELS
ON WINDS WEDNESDAY EVENING SO STAYED AWAY FROM A GALE WATCH FOR
WEDNESDAY EVENING. THEN MODERATE WEST TO NORTHWEST SWELL WITH VERY
LONG PERIOD WILL ALSO ENTER THE REGION THURSDAY AND THEN LOWER ON
FRIDAY. NORTH WINDS MAY LOWER BRIEFLY ON FRIDAY BEFORE
STRENGTHENING AGAIN THIS WEEKEND. /SMITH
&&
.PREV DISCUSSION... /ISSUED 522 PM PDT MON APR 13 2015/
SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT.
THE MAIN ITEMS OF INTEREST IN THE SHORT TERM ARE GUSTY WINDS
TONIGHT (STRONGEST ON THE EAST SIDE), RAIN AND SNOW WITH FALLING
SNOW LEVELS TONIGHT, A SLIGHT CHANCE OF COASTAL THUNDERSTORMS
LATE THIS EVENING INTO EARLY TUESDAY MORNING, SHOWERS AND SNOW
SHOWERS LATE TONIGHT INTO TUESDAY EVENING, AND COLD MORNING LOW
TEMPERATURES.
THERE WAS LITTLE ADJUSTMENT NEEDED TO THE FORECAST FOR TONIGHT.
A FAST MOVING COLD FRONT IS NOW REACHING THE COAST. WESTERLY
WINDS THIS AFTERNOON HAVE INCREASED TO RIGHT AROUND THE EXPECTED
STRENGTH. THE 12Z GFS MOS WIND SPEEDS WERE FORECAST TO BE SLIGHTLY
STRONGER THAN THE NAM MOS, AND ARE VERIFYING WELL AT THIS TIME
WITH WIDESPREAD REPORTS OF GUSTY, BREEZY 15 TO 25 MPH
WINDS...INCLUDING GUSTS OF 43 MPH AT SUMMER LAKE.
SNOW LEVELS WILL DROP QUICKLY FROM AROUND 6000 TO 7000 FEET THIS
AFTERNOON TO AROUND 2500 TO 3000 FEET BY THE TIME PRECIPITATION
TAPERS TO LIGHT SHOWERS LATE TONIGHT. THE BULK OF COASTAL RAIN
WILL FALL FROM NOW THROUGH THE EARLY EVENING, MAINLY AN EVENING
EVENT FOR THE WEST SIDE, AND A LATE NIGHT EVENT FOR THE EAST SIDE.
SNOWFALL OF 2 TO 5 INCHES IS EXPECTED AROUND CRATER LAKE WITH 1 TO
2 INCHES FOR MUCH OF THE CASCADES, AND GENERALLY LESS THAN AN INCH
OF SNOW ON THE EAST SIDE.
THE SLIGHT CHANCE OF COASTAL THUNDERSTORMS WILL ARISE FROM A
POST-FRONTAL SURFACE TROUGH THAT WILL HAVE ITS LANDFALL COINCIDE
WITH THE AXIS OF THE UPPER LEVEL TROUGH/COLDEST AIR ALOFT MOVING
INLAND. I MENTIONED IT IN YESTERDAY`S DISCUSSION AND IT BEARS
REPEATING THAT THE WEATHER ON TUESDAY WILL HAVE A RESEMBLANCE TO
WHAT OCCURRED ON SATURDAY. A COLD, WEAKLY UNSTABLE NORTHWEST FLOW
ALOFT WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS AND SNOW SHOWERS
THAT WILL FALL OUT OF LOW TOPPED CUMULUS CLOUDS. THE SNOW LEVEL ON
TUESDAY WILL RISE FROM AROUND 2500 FEET TO AROUND 3500 FEET WITH
AN ADDITIONAL INCH OF SNOW POSSIBLE IN THE CASCADES EXCEPT LIKELY
A BIT MORE (AROUND 2 INCHES) FOR CRATER LAKE.
VALLEY LOW CLOUDS AND PATCHY FOG ARE LIKELY TO HINDER COOLING
DURING EACH OF THE NEXT TWO NIGHTS, BUT IT WILL STILL BE QUITE
COLD ANYWAY WITH LOWS SEVERAL DEGREES BELOW NORMAL.
HIGH PRESSURE CENTERED OFFSHORE FROM CALIFORNIA WILL BUILD INTO
THE WEST COAST AND BRING A RETURN OF MOSTLY CLEAR TO CLEAR SKIES
WITH A WARMING TREND WEDNESDAY THROUGH THURSDAY.
LONG TERM...FRIDAY THROUGH MONDAY.
WARM AND DRY CONDITIONS WILL PERSIST THROUGH THE WEEKEND AS A
STRONG LONG WAVE RIDGE SETTLES JUST OFF THE WEST COAST WITH
NORTHERLY FLOW ALOFT AND LOW LEVEL OFFSHORE FLOW. A SHORT WAVE
TROUGH IS FORECAST TO MOVE ACROSS WASHINGTON AND NORTHERN OREGON
ON FRIDAY. THE MAIN EFFECT FROM THIS FEATURE IS TO PUSH HIGH
TEMPERATURES DOWN A FEW DEGREES ALTHOUGH IT WILL STILL BE ABOVE
SEASONAL NORMS. WE MAY ALSO SEE A SLIGHT INCREASE IN THE SURFACE
WESTERLY WINDS. THE GFS SHOWS SOME INSTABILITY IN TERMS OF THE
LIFTED INDEX BUT WESTERLY FLOW IS GENERALLY NOT FAVORABLE FOR
THUNDERSTORMS AND MOISTURE WILL BE VERY LIMITED.
ON SATURDAY THE LONG WAVE RIDGE REBUILDS WESTWARD TO AROUND
LONGITUDE 130W ALLOWING THE SHORT WAVE TROUGH TO DROP SOUTH ACROSS
OUR FORECAST AREA IN THE NORTH TO NORTHWEST FLOW ALOFT. THERE
SEEMS TO BE MORE INSTABILITY ACROSS OUR NORTHERN CALIFORNIA ZONE
SOUTHWARD. AT THIS POINT WE FEEL THAT THIS WOULD TRANSLATE INTO
MORE CUMULUS BUILDUPS OVER THE SISKIYOUS AND THE MARBLE MOUNTAINS
ON SATURDAY. THE RIDGE CONTINUES TO BUILD INTO THE WEST COAST
SUNDAY AND MONDAY. DURING THE PAST 10 RUNS THE GFS TREND HAS BEEN
TO FORECAST HIGHER 500 MB HEIGHT OVER THE PACIFIC NORTHWEST SO
CONFIDENCE IS HIGH THAT WE WILL SEE A WARM AND DRY TREND. HIGHS
IN THE ROGUE VALLEY ARE FORECAST TO BE IN THE LOWER 80S FROM
FRIDAY THROUGH MONDAY (WITH THE EXCEPTION OF SATURDAY DUE TO CLOUD
COVER). IF THIS SCENARIO HOLDS TRUE, THIS IS ALMOST 20 DEGREES
ABOVE SEASONAL NORMS FOR MID APRIL FOR THE ROGUE VALLEY AND ABOUT
15 DEGREES ABOVE NORMAL FOR AREAS EAST OF THE CASCADES. /FB
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 11 PM PDT THIS EVENING FOR ORZ026-620>623.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 PM PDT THIS EVENING FOR
PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT TUESDAY
FOR PZZ350-356.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT TUESDAY
FOR PZZ370-376.
$$
NSK/FJB/MAS
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
1021 PM EDT MON APR 13 2015
.DISCUSSION...PREVIOUS FORECAST ON TRACK FOR THE MOST PART. IT`S
BEEN A RELATIVELY DRY EVENING BUT THINGS ARE QUICKLY CHANGING.
LATEST MODEL RUNS OF THE HRRR AND RAP BOTH SHOW INCREASING MOISTURE
TRANSPORT INTO OUR AREA. MCV THAT IS CURRENTLY ACROSS WEST TN WILL
CONTINUE ADVANCING NORTHEAST THROUGH MIDDLE TN AND CENTRAL AND
EASTERN KY. FRONTAL BOUNDARY DRAPED ACROSS THE OHIO RIVER VALLEY
WILL ALSO SLOWLY MOVE SE BUT SHOULD STAY WELL NORTH OF OUR AREA.
AT THIS TIME IT LOOKS LIKE THE HEAVIEST AXIS OF PRECIP SHOULD STAY
TO OUR NW...ACROSS MIDDLE TN INTO CENTRAL/EASTERN KY AND UP THROUGH
WV WHERE MCV WILL INTERACT JUST SOUTH OF AFOREMENTIONED BOUNDARY.
HAVING SAID THAT...STILL EXPECTING SHOWER ACTIVITY TO CONTINUE TO
INCREASE ACROSS OUR AREA AS THE NIGHT PROGRESSES. OUR WESTERN AREAS
HAVE THE BEST CHANCE OF SEEING SOME OF THE HEAVIER RAINFALL...AREAS
ALONG THE CUMBERLAND PLATEAU AND POSSIBLY WISE AND LEE COUNTY VA. PWATS
VERY IMPRESSIVE THIS EVENING WITH THE SOUTHERN VALLEY NEAR MAX
VALUES FOR THIS TIME OF YEAR (1.7 INCHES) AND THE REMAINDER OF OUR
AREA NEAR THE 99TH PERCENTILE (1.4 TO 1.5 INCHES). GREATEST
COVERAGE OF PRECIP EXPECTED TO OCCUR BETWEEN 06 AND 12Z.
THE BIGGEST ADJUSTMENT MADE TO ZONES WAS TO TAKE OUT SLIGHT CHANCE
OF THUNDER FOR ALL AREAS EXCEPT THE EXTREME SOUTHERN VALLEY AND
SWNC. EVEN ACROSS THESE AREAS INSTABILITY IS LIMITED TO ONLY A FEW
HUNDRED J/KG CAPE. EVERYTHING ELSE LOOKS GOOD. MADE TWEAKS TO TEMPS
AND DEWPOINTS TO MATCH OBSERVATIONS. NEW ZONES OUT SHORTLY TO
ACCOUNT FOR REMOVAL OF THUNDER.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 66 73 56 69 / 90 80 50 60
KNOXVILLE MCGHEE TYSON AIRPORT, TN 61 73 55 68 / 90 80 40 60
OAK RIDGE, TN 64 70 54 68 / 90 80 40 60
TRI CITIES AIRPORT, TN 59 69 51 64 / 90 80 40 50
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SR
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
949 PM CDT Mon Apr 13 2015
.UPDATE...
The cold front has moved south to the I-10 corridor, masked
somewhat by convective outflow from this evening`s thunderstorms.
Winds have shifted to the northeast at 5 to 15 mph and will remain
so overnight. Dewpoints have already fallen into the 40s across
western north TX and this drier air will advect into the region
tonight, limiting the potential for additional measurable
precipitation. However, PoPs were maintained areawide given the
presence of the cold core of the upper cyclone moving slowly
across the CWA through early Tuesday. Rain chances were trimmed
back Tuesday, with most areas expected to remain dry. Expect high
temperatures in the upper 60s to lower 70s with northwest winds
around 10 mph.
The Flash Flood and Severe Thunderstorm Watches were dropped as
conditions are no longer favorable for significant convection.
Johnson
&&
.PREV DISCUSSION... /ISSUED 636 PM CDT Mon Apr 13 2015/
AVIATION...
/00Z TAFS/
Showers and thunderstorms will affect the KABI and KSJT terminals
this evening. The storms were developing along and behind a Cold
front that extended from just north of San Angelo and Brady. Winds
will shift to the north just after 00Z at KSJT and KBBD as the
front moves through. MVFR ceilings will develop a couple hours after
frontal passage. The front should move through KSOA and KJCT
around 4Z. MVFR ceilings should rise to IFR Tuesday noon over most
sites.
PREV DISCUSSION... /ISSUED 416 PM CDT Mon Apr 13 2015/
UPDATE...
Added a flash flood watch through 1 AM CDT for portions of the Big
Country...Concho Valley and Heartland until 1 AM CDT. Slow moving
thunderstorms along and north of a cold front will produce quick
heavy rainfall amounts of 1 to 3 inches...and may result in flash
flooding.
PREV DISCUSSION... /ISSUED 353 PM CDT Mon Apr 13 2015/
SHORT TERM...
(Tonight and Tuesday)
Scattered showers and thunderstorms were developing along and north
of a cold front from Mertzon to San Angelo to Brownwood at 3 PM.
SPC RAP analysis indicated SB CAPES around 1000 J/KG in this
area...which is a slight risk for severe thunderstorms this
afternoon and evening. The slight risk extends to the I-20 corridor.
While the severe threat is large hail and damaging winds are the
main threats, slow moving thunderstorms focused along the front will
also bring the potential for localized heavy rainfall and flash
flooding. If storm coverage becomes widespread, a flash flood watch
may be needed for Concho Valley to Brownwood and northward to the
I-20 corridor. With an upper low to the northwest in the South
Plains, there is also a low potential for a land spout or brief
tornado. The heavy rain and severe weather threat will diminish a
couple hours after sunset.
The front is indicated to move south to I-10 by midnight. Included a
slight chance of showers or thunderstorms for southern areas, but
severe weather threat is minimal as the front moves into more stable
air.
Keeping a slight chance of showers and thunderstorms, along and
northwest of a Sweetwater to Junction line...but most of the
moisture and instability will be southeast of West Central Texas.
LONG TERM...
(Tuesday night through next Monday)
Dry and warmer conditions are expected Wednesday, as south winds
develop. An upper low will drop southeast into the Central Rockies.
The 12Z GFS and ECMWF differ on the track of this low, and this will
have implications on our rain chances Thursday into the weekend. The
ECMWF is slower and takes the upper low south into New Mexico Friday
and Friday night, then eventually opens the low and tracks the wave
east into Oklahoma Saturday night and Sunday. The GFS has an
elongated trough extending south from the low, and has the low
dropping southeast into the Red River Valley Friday night into
Saturday.
With enough moisture return/availability indicated, we have chance
PoPs for showers and thunderstorms beginning Wednesday night in the
west, and continuing Thursday through late Saturday. A cold frontal
passage is anticipated Thursday night into Friday, but have
uncertainty on the timing with the aforementioned model differences.
Will have to monitor the forecast setup for the potential of strong
to severe storms.
The forecast looks dry Sunday into the first part of next week with
temperatures close to normal.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 50 64 50 82 62 / 40 20 10 10 20
San Angelo 52 70 52 84 62 / 20 10 10 10 20
Junction 55 73 54 84 63 / 20 20 10 10 20
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
636 PM CDT Mon Apr 13 2015
.AVIATION...
/00Z TAFS/
Showers and thunderstorms will affect the KABI and KSJT terminals
this evening. The storms were developing along and behind a Cold
front that extended from just north of San Angelo and Brady. Winds
will shift to the north just after 00Z at KSJT and KBBD as the
front moves through. MVFR ceilings will develop a couple hours after
frontal passage. The front should move through KSOA and KJCT
around 4Z. MVFR ceilings should rise to IFR Tuesday noon over most
sites.
&&
.PREV DISCUSSION... /ISSUED 416 PM CDT Mon Apr 13 2015/
UPDATE...
Added a flash flood watch through 1 AM CDT for portions of the Big
Country...Concho Valley and Heartland until 1 AM CDt. Slow moving
thunderstorms along and north of a cold front will produce quick
heavy rainfall amounts of 1 to 3 inches...and may result in flash
flooding.
PREV DISCUSSION... /ISSUED 353 PM CDT Mon Apr 13 2015/
SHORT TERM...
(Tonight and Tuesday)
Scattered showers and thunderstorms were developing along and north
of a cold front from Mertzon to San Angelo to Brownwood at 3 PM.
SPC RUC analysis indicated SB CAPES around 1000 J/KG in this
area...which is a slight risk for severe thunderstorms this
afternoon and evening. The slight risk extends to the I-20 corridor.
While the severe threat is large hail and damaging winds are the
main threats, slow moving thunderstorms focused along the front will
also bring the potential for localized heavy rainfall and flash
flooding. If storm coverage becomes widespread, a flash flood watch
may be needed for Concho Valley to Brownwood and northward to the
I-20 corridor. With an upper low to the northwest in the South
Plains, there is also a low potential for a land spout or brief
tornado. The heavy rain and severe weather threat will diminish a
couple hours after sunset.
The front is indicated to move south to I-10 by midnight. Included a
slight chance of showers or thunderstorms for southern areas, but
severe weather threat is minimal as the front moves into more stable
air.
Keeping a slight chance of showers and thunderstorms, along and
northwest of a Sweetwater to Junction line...but most of the
moisture and instability will be southeast of West Central Texas.
LONG TERM...
(Tuesday night through next Monday)
Dry and warmer conditions are expected Wednesday, as south winds
develop. An upper low will drop southeast into the Central Rockies.
The 12Z GFS and ECMWF differ on the track of this low, and this will
have implications on our rain chances Thursday into the weekend. The
ECMWF is slower and takes the upper low south into New Mexico Friday
and Friday night, then eventually opens the low and tracks the wave
east into Oklahoma Saturday night and Sunday. The GFS has an
elongated trough extending south from the low, and has the low
dropping southeast into the Red River Valley Friday night into
Saturday.
With enough moisture return/availability indicated, we have chance
PoPs for showers and thunderstorms beginning Wednesday night in the
west, and continuing Thursday through late Saturday. A cold frontal
passage is anticipated Thursday night into Friday, but have
uncertainty on the timing with the aforementioned model differences.
Will have to monitor the forecast setup for the potential of strong
to severe storms.
The forecast looks dry Sunday into the first part of next week with
temperatures close to normal.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 51 64 50 82 62 / 70 20 10 10 20
San Angelo 53 70 52 84 62 / 60 10 10 10 20
Junction 56 73 54 84 63 / 20 20 10 10 20
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH until 1 AM CDT Tuesday FOR THE FOLLOWING
ZONES: Brown...Callahan...Coke...Coleman...Concho...Fisher...
Irion...Jones...McCulloch...Nolan...Runnels...San Saba...
Shackelford...Sterling...Taylor...Tom Green.
&&
$$
99/99/04
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
412 PM CDT SUN APR 12 2015
.SHORT TERM...
(Tonight and Monday)
Band of strong thunderstorms will likely move quickly east through
West Central Texas this evening. The storms moving through the Big
Bend and western Permian Basin at 3 PM CDT. With strong lift ahead
an upper low near El Paso, the short range models, including the
Texas Tech WRF and the HRRR indicate the line of storms to move into
Crockett County 5-6 PM...along a Sweetwater to San Angelo to Sonora
line around 8 PM...and an Abilene to Junction line 9-10 PM CDT.
There is the potential for a severe thunderstorm or two, as the SPC
mesoanalysis RUC indicated between 2000-3000 J/KG over the region.
The mostly likely impact however will be wind gusts of 40 to 50 mph
along the initial line of storms. SPC Day 1 Outlook has marginal
potential for severe storms for areas south of I-20 with a slight
risk just south of West Central Texas. This looks good as GFS 0-6 KM
shear was 20-35 KTS with the highest values along the I-10 corridor.
Rain chances diminish after midnight as the storm complex moves east.
West Central is somewhat dry-slotted Monday, at least south of the
I-20 corridor as the upper low moves slowly through. A weak cold
front will push through the Big Country late morning and afternoon,
bringing the the best chances of storms to the north. There is a
marginal potential for severe storms, but potential is somewhat
limited with lower GFS SB CAPES of 500 to 1500 mainly in northern
and eastern sections.
.LONG TERM...
(Monday night through next Saturday)
An interesting weather pattern is setting up for much of the week.
An upper-level low will be located over eastern New Mexico/western
parts of the Panhandle tomorrow evening, with a cold front dropping
south through the Big Country, and a dryline extending south through
western parts of the area (roughly along a Sweetwater to Sonora
line). Showers and thunderstorms will develop north of the front, as
south to southwest flow aloft maintains good isotropic ascent.
Additionally, a few showers or thunderstorms may develop in the warm
sector south of the front and ahead of the dryline. Isolated severe
thunderstorms may develop in this area, with locally heavy rain also
possible.
As the system departs the area Tuesday into Wednesday, drier air
will move back into the region. This will be short-lived however, as
another strong shortwave trough develops across the Inter-mountain
West, resulting in dryline development across western parts of the
Panhandle and West Texas Wednesday night/Thursday. Moisture will
again build across the area, with showers and thunderstorms possible
during this time period. As this next system departs the area Friday
and Saturday, dry air will move back into the region, with sunny
skies and warm temperatures expected.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 58 77 53 70 50 / 70 50 60 20 10
San Angelo 58 84 54 73 52 / 60 20 30 10 10
Junction 60 82 55 76 53 / 60 20 20 10 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
04/Doll
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1258 PM CDT Sun Apr 12 2015
.AVIATION...
/18Z TAFS/
Band of showers and thundestorms will move in from the west this
evening as an upper low approaches. Ceilings temporarily may become
MVFR with thunderstorm activity. After the storms move east, MVFR
ceilings may again develop, mainly between 6Z and 12Z.
&&
.PREV DISCUSSION... /ISSUED 612 AM CDT Sun Apr 12 2015/
AVIATION...
/12Z TAFS/
MVFR to IFR ceilings will continue at all sites this morning, with
VFR ceilings returning by late morning or early afternoon. Showers
and thunderstorms will be possible late this afternoon and evening
at all sites, but confidence in timing and coverage remains low,
so only VCTS groups were included. Most showers and thunderstorms
should be east of the TAF sites by 06z.
PREV DISCUSSION... /ISSUED 418 AM CDT Sun Apr 12 2015/
SHORT TERM...
(Today and Tonight)
The main concern through the next 24 hours is the potential for
showers and thunderstorms as an upper level low approaches from
the west. An upper level low is currently centered across northern
Baja California and is forecast to approach far West Texas this
evening. PoPs for today were reduced across much of the area, as
most of the upper level lift associated with the low will not
overspread the area until late this afternoon and overnight.
Still, isolated to scattered showers will be possible this
afternoon, mainly across the southern and western parts of the
forecast area. Highs today will be in the upper 70s to lower 80s.
Overnight, the chance of showers and thunderstorms will increase
as the upper level approaches and upper level lift overspreads
West Central Texas. Some uncertainty remains on the extent of
precipitation overnight, with some indications that parts of the
area may get dry slotted, mainly across the northern Edwards
Plateau and possibly parts of the Concho Valley. PoPs were lowered
slightly, ranging from chance across the northern Edwards Plateau
and Concho Valley, to likely across the northern Big Country and
northwest Hill Country. Latest runs of the HRRR are optimistic in
a large area of showers and thunderstorms approaching our western
counties by late afternoon/early evening, but am reluctant to go
too high on PoPs at this time. The main threat with the convection
looks to be locally heavy rainfall and dangerous cloud to ground
lightning. Rain chances will quickly decrease from southwest to
northeast during the early morning hours Monday. Overnight lows
will be in the upper 50s to lower 60s.
LONG TERM...
(Monday through Saturday)
Forecast challenges will be rain chances mainly Monday/Monday
night, and then again later in the week.
By Monday, the upper low over the Baja Peninsula this morning will
be moving into the southeastern NM/west Texas area. At the same
time, and cold front will be moving south through the Texas
Panhandle and western Oklahoma. The combination of these two
synoptic features will result in showers and thunderstorms
developing mainly along and ahead of the cold front Monday.
Showers and thunderstorms are most likely along and north of a
Sterling City to Brownwood line in the vicinity of the cold front.
Exactly where the cold front progresses to by Monday afternoon is
still in question however. So, with the front in the area,
increasing deep layer shear, and moderate instability in place
along/ahead of the cold front, it isn`t out of the question that
some of the thunderstorms that do develop could strengthen to
severe levels Monday afternoon and evening, especially along the
cold front. Severe weather hazards would be limited mainly to
large hail and damaging winds if it occurs. PoP values go from
`likely` (60%) in the Big Country, to slight chance and chance
(20-30%) along the I-10 corridor, based on the cold front stalling
near the Sterling City/Brownwood line in the afternoon. Rain
chances continue into the evening hours, mainly for the northern
half of the CWA, with decreasing rain chances Tuesday as the upper
level low moves off to the northeast away from the area.
Southwest flow returns Tuesday night into Wednesday with generally
dry weather across the area.
The next chance for rain begins Wednesday night into Thursday as
another low drops south through the Rocky Mountains into the four
corners region, then turns east, and moves across the Texas
panhandle region into the southern plains. Have kept a slight
chance to chance in the forecast from Wednesday night through
Thursday night for this feature. However, with very dry air aloft
rotating to the east around the south side of the upper level low,
there is some concern that the best precipitation chances would be
pushed to the east of our area.
Have kept the generally dry forecast going for the area from
Friday into Saturday. However, the latest run of the ECMWF is now
stalling the upper level low near the four corners region through
this time period resulting in additional rain chances. Will have
to keep an eye on model trends concerning this change, and update
the forecast as needed.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 59 75 55 72 51 / 50 60 50 20 10
San Angelo 58 79 55 75 53 / 50 40 20 10 10
Junction 60 79 56 78 55 / 60 30 20 10 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
4
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
612 AM CDT Sun Apr 12 2015
.AVIATION...
/12Z TAFS/
MVFR to IFR ceilings will continue at all sites this morning, with
VFR ceilings returning by late morning or early afternoon. Showers
and thunderstorms will be possible late this afternoon and evening
at all sites, but confidence in timing and coverage remains low,
so only VCTS groups were included. Most showers and thunderstorms
should be east of the TAF sites by 06z.
&&
.PREV DISCUSSION... /ISSUED 418 AM CDT Sun Apr 12 2015/
SHORT TERM...
(Today and Tonight)
The main concern through the next 24 hours is the potential for
showers and thunderstorms as an upper level low approaches from
the west. An upper level low is currently centered across northern
Baja California and is forecast to approach far West Texas this
evening. PoPs for today were reduced across much of the area, as
most of the upper level lift associated with the low will not
overspread the area until late this afternoon and overnight.
Still, isolated to scattered showers will be possible this
afternoon, mainly across the southern and western parts of the
forecast area. Highs today will be in the upper 70s to lower 80s.
Overnight, the chance of showers and thunderstorms will increase
as the upper level approaches and upper level lift overspreads
West Central Texas. Some uncertainty remains on the extent of
precipitation overnight, with some indications that parts of the
area may get dry slotted, mainly across the northern Edwards
Plateau and possibly parts of the Concho Valley. PoPs were lowered
slightly, ranging from chance across the northern Edwards Plateau
and Concho Valley, to likely across the northern Big Country and
northwest Hill Country. Latest runs of the HRRR are optimistic in
a large area of showers and thunderstorms approaching our western
counties by late afternoon/early evening, but am reluctant to go
too high on PoPs at this time. The main threat with the convection
looks to be locally heavy rainfall and dangerous cloud to ground
lightning. Rain chances will quickly decrease from southwest to
northeast during the early morning hours Monday. Overnight lows
will be in the upper 50s to lower 60s.
LONG TERM...
(Monday through Saturday)
Forecast challenges will be rain chances mainly Monday/Monday
night, and then again later in the week.
By Monday, the upper low over the Baja Peninsula this morning will
be moving into the southeastern NM/west Texas area. At the same
time, and cold front will be moving south through the Texas
Panhandle and western Oklahoma. The combination of these two
synoptic features will result in showers and thunderstorms
developing mainly along and ahead of the cold front Monday.
Showers and thunderstorms are most likely along and north of a
Sterling City to Brownwood line in the vicinity of the cold front.
Exactly where the cold front progresses to by Monday afternoon is
still in question however. So, with the front in the area,
increasing deep layer shear, and moderate instability in place
along/ahead of the cold front, it isn`t out of the question that
some of the thunderstorms that do develop could strengthen to
severe levels Monday afternoon and evening, especially along the
cold front. Severe weather hazards would be limited mainly to
large hail and damaging winds if it occurs. PoP values go from
`likely` (60%) in the Big Country, to slight chance and chance
(20-30%) along the I-10 corridor, based on the cold front stalling
near the Sterling City/Brownwood line in the afternoon. Rain
chances continue into the evening hours, mainly for the northern
half of the CWA, with decreasing rain chances Tuesday as the upper
level low moves off to the northeast away from the area.
Southwest flow returns Tuesday night into Wednesday with generally
dry weather across the area.
The next chance for rain begins Wednesday night into Thursday as
another low drops south through the Rocky Mountains into the four
corners region, then turns east, and moves across the Texas
panhandle region into the southern plains. Have kept a slight
chance to chance in the forecast from Wednesday night through
Thursday night for this feature. However, with very dry air aloft
rotating to the east around the south side of the upper level low,
there is some concern that the best precipitation chances would be
pushed to the east of our area.
Have kept the generally dry forecast going for the area from
Friday into Saturday. However, the latest run of the ECMWF is now
stalling the upper level low near the four corners region through
this time period resulting in additional rain chances. Will have
to keep an eye on model trends concerning this change, and update
the forecast as needed.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 81 59 75 55 72 / 20 50 60 50 20
San Angelo 80 58 79 55 75 / 40 50 40 20 10
Junction 80 60 79 56 78 / 40 60 30 20 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/99
AREA FORECAST DISCUSSION
NWS EL PASO TX/SANTA TERESA NM
359 AM MDT SUN APR 12 2015
.SYNOPSIS...
UPPER LOW OVER NORTHWEST MEXICO WILL MOVE NORTHEAST ACROSS NORTHERN
MEXICO AND OVER THE TEXAS PANHANDLE BY MONDAY EVENING. THIS WILL
SPREAD SHOWERS AND A FEW THUNDERSTORMS TO THE BORDERLAND TODAY AND
MONDAY. THE LOW MOVES OUT LATE MONDAY NIGHT AND SHOULD END THE
WIDESPREAD SHOWERS. RESIDUAL MOISTURE AND WEAK DISTURBANCES ALOFT
WILL CONTINUE A CHANCE OF SHOWERS TUESDAY THROUGH FRIDAY...THOUGH
MOSTLY OVER THE MOUNTAINS. TEMPERATURES MOST OF THIS PERIOD WILL BE
QUITE COOL. DRIER NORTHWEST FLOW MOVES IN FOR THE WEEKEND WITH VERY
FEW CLOUDS AND TEMPERATURES BACK ABOVE NORMAL.
&&
.DISCUSSION...
UPPER LOW NOT WELL DEFINED YET AS A CIRCULATION BUT LIKELY OVER THE
NORTHERN GULF OF CALIFORNIA. SYSTEM IS BEGINNING TO ENTRAIN SUB
TROPICAL MOISTURE INTO IT AND AND PRODUCED A LARGE THICK CLOUD
SHIELD OVER THE CWA. RADAR IS SHOWING A FEW WEAK TO MODERATE SHOWERS
MOVING INTO EL PASO AND DONA ANA COUNTIES. HRRR SHOWING SOME
ISOLATED CELLS TIL ABOUT 12Z ALONG THE SOUTHERN CWA THEN MORE
WIDESPREAD RAIN STARTING AROUND 13Z OVER THE BOOTHEEL AND THEN TO
ALL THE SOUTHERN ZONES BY AROUND 18Z. RAIN SPREADING TO REST OF AREA
THROUGH TONIGHT...THOUGH BEST RAINFALL MAY REMAIN FROM ABOUT LAS
CRUCES SOUTH. SHOWERS SHOULD CONTINUE MONDAY THOUGH MAY FAVOR THE
EAST HALF OF THE CWA MORE AS UPPER LOW MOVES JUST EAST OF THE AREA.
AIRMASS WEAKLY UNSTABLE BUT WILL STILL KEEP A MENTION OF THUNDER IN
THE FORECAST. TEMPERATURES WILL COOL SIGNIFICANTLY WITH THE
EXTENSIVE CLOUD COVER AND EASTERLY SURGE ON MONDAY.
SYSTEM MOVES OUT OF THE AREA LATE MONDAY NIGHT...BUT MODELS CONTINUE
TO SHOW RESIDUAL MOISTURE PERSISTING THROUGH WEDNESDAY. WEAK UPPER
DISTURBANCES AND WEAK INSTABILITY WILL LIKELY CONTINUE A FEW SHOWERS
BUT MOSTLY OVER THE MOUNTAINS. THURSDAY LOOKS INTERESTING AS PAC
NORTHWEST UPPER LOW DROPS DOWN TO FAR WESTERN NEW MEXICO. THIS WILL
INITIALLY ALLOW SCOURING OUT OF LOW LEVEL MOISTURE. GFS SHOWS STRONG
DRYLINE TO THE RIO GRANDE THURSDAY MORNING AND EAST OF THE CWA
THURSDAY AFTERNOON. THURSDAY SHOULD BE RELATIVELY FREE OF PRECIP
THOUGH WILL HAVE TO WATCH DRYLINE BOUNDARY FOR BRIEF
SHOWERS/THUNDERSTORMS NEAR THE BOUNDARY. TEMPERATURES WILL WARM BACK
TO CLOSE TO NORMAL TUESDAY AND WEDNESDAY BUT UPPER LOW WILL DRAG
SIDE DOOR FRONT DOWN THURSDAY TO COOL BACK DOWN. SNOW LEVELS THROUGH
THIS PERIOD COULD DROP AS LOW AS 8000 FT WEDNESDAY AND PERHAPS AS
LOW AS 7500 FT THURSDAY...SO MODEST SNOW ACCUMULATIONS ARE POSSIBLE
AT THE HIGH ELEVATIONS.
UPPER LOW EVENTUALLY BRINGS WRAP AROUND MOISTURE TO AREA FRIDAY BUT
LOW LEVELS ONLY MOISTEN UP SLIGHTLY. WILL KEEP LOW POPS IN FOR THE
SACS...BEING AS THEY ARE CLOSEST TO THE UPPER LOW AND MOISTURE. LOW
FINALLY MOVES OFF FRIDAY NIGHT AND DRIER NORTHWEST FLOW ALOFT WILL
MOVE IN FOR NEXT WEEKEND. TEMPERATURES SHOULD WARM BACK ABOVE NORMAL.
&&
.AVIATION...VALID 12/12Z-13/12Z...
AN APPROACHING UPPER LEVEL STORM WILL RESULT IN LOWERING CEILINGS
THRU THE TAF PERIOD ALONG WITH OCCASIONAL RAIN SHOWERS AND BRIEF
REDUCTIONS IN VISIBILITY. VFR CONDITIONS WILL BE THE GENERAL RULE
WITH POSSIBLE BRIEF EXCURSIONS INTO MVFR CONDITIONS WITH HEAVIER
SHOWERS. INITIALLY EXPECT VCSH SCT050 BKN-OVC100 WITH BKN-OVC050
DEVELOPING FROM THE SOUTHWEST BETWEEN 16Z AND 18Z. WINDS WILL
REMAIN FROM THE SOUTHWEST THRU THE PERIOD WITH SPEEDS OCCASIONALLY
EXCEEDING 12 KNOTS ALONG WITH 5SM ASSOCIATED WITH PASSING SHRA.
&&
.FIRE WEATHER...
AN UPPER LEVEL STORM SYSTEM WILL APPROACH THE REGION FROM THE
SOUTHWEST TODAY AND WILL SLOWLY CROSS THE AREA THROUGH EARLY
TUESDAY. THIS WILL RESULT IN INCREASED CLOUD COVER AND CHANCES FOR
WETTING PRECIPITATION WITH OCCASIONAL THUNDER POSSIBLE. WHILE 20 FT
WINDS WILL BE GUSTY AT TIMES AS THE SYSTEM MOVES THROUGH...COOLER
TEMPS AND HIGHER DEW POINTS WILL RESULT IN INCREASED MIN RH VALUES.
AS A RESULT CRITICAL FIRE WEATHER THRESHOLDS ARE NOT EXPECTED FOR
SEVERAL DAYS. ANOTHER UPPER LEVEL SYSTEM WILL BEGIN TO AFFECT THE
REGION FOR THE MIDDLE TO LATER PARTS OF NEXT WEEK. AN INCREASE IN
WINDS AND TEMPS COULD CAUSE SOME FIRE WEATHER CONCERNS BRIEFLY FOR
WEDNESDAY. HOWEVER A CHANCE FOR ADDITIONAL WETTING PRECIP AND COOLER
TEMPS BEHIND A PASSING FRONT WILL ALLEVIATE ANY CONCERNS FOR THE
REST OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
EL PASO 67 51 65 49 74 / 50 60 40 20 0
SIERRA BLANCA 65 50 58 48 70 / 50 60 40 30 0
LAS CRUCES 66 50 63 47 73 / 40 50 20 10 0
ALAMOGORDO 70 51 62 46 71 / 40 80 50 30 0
CLOUDCROFT 50 39 45 35 53 / 40 90 70 40 10
TRUTH OR CONSEQUENCES 67 51 62 45 72 / 20 40 30 10 0
SILVER CITY 56 45 53 43 70 / 30 40 20 20 0
DEMING 65 49 65 46 74 / 40 40 20 10 0
LORDSBURG 64 47 66 45 75 / 40 30 20 10 0
WEST EL PASO METRO 67 53 64 52 74 / 50 50 40 20 0
DELL CITY 67 46 61 45 72 / 40 60 50 30 0
FORT HANCOCK 69 48 64 48 74 / 50 60 40 20 0
LOMA LINDA 59 50 55 48 70 / 50 60 40 30 0
FABENS 68 47 64 47 74 / 50 60 40 20 0
SANTA TERESA 67 50 63 48 74 / 50 50 20 20 0
WHITE SANDS HQ 66 55 62 50 72 / 30 60 40 20 0
JORNADA RANGE 67 49 63 42 73 / 30 50 30 20 0
HATCH 66 49 65 45 74 / 30 50 20 10 0
COLUMBUS 64 52 64 49 73 / 40 40 20 20 0
OROGRANDE 67 53 60 48 71 / 40 60 40 30 0
MAYHILL 59 44 49 39 61 / 40 80 70 40 10
MESCALERO 58 43 50 38 61 / 40 90 70 40 10
TIMBERON 57 43 50 40 61 / 50 70 60 40 10
WINSTON 58 43 57 36 69 / 20 40 20 20 10
HILLSBORO 61 46 59 43 73 / 30 40 20 20 0
SPACEPORT 68 47 63 42 73 / 30 50 30 10 0
LAKE ROBERTS 56 39 57 41 69 / 40 40 30 20 10
HURLEY 57 45 56 43 70 / 40 40 20 20 0
CLIFF 64 43 62 43 71 / 30 40 20 20 0
MULE CREEK 60 41 60 40 70 / 30 40 20 20 0
FAYWOOD 58 46 58 44 71 / 30 40 20 20 0
ANIMAS 63 49 67 47 75 / 50 30 20 10 0
HACHITA 64 48 66 45 74 / 50 30 20 10 0
ANTELOPE WELLS 61 48 64 46 74 / 60 30 20 10 0
CLOVERDALE 55 45 60 45 74 / 50 30 20 10 0
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
17 HEFNER
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
418 AM CDT Sun Apr 12 2015
.SHORT TERM...
(Today and Tonight)
The main concern through the next 24 hours is the potential for
showers and thunderstorms as an upper level low approaches from
the west. An upper level low is currently centered across northern
Baja California and is forecast to approach far West Texas this
evening. PoPs for today were reduced across much of the area, as
most of the upper level lift associated with the low will not
overspread the area until late this afternoon and overnight.
Still, isolated to scattered showers will be possible this
afternoon, mainly across the southern and western parts of the
forecast area. Highs today will be in the upper 70s to lower 80s.
Overnight, the chance of showers and thunderstorms will increase
as the upper level approaches and upper level lift overspreads
West Central Texas. Some uncertainty remains on the extent of
precipitation overnight, with some indications that parts of the
area may get dry slotted, mainly across the northern Edwards
Plateau and possibly parts of the Concho Valley. PoPs were lowered
slightly, ranging from chance across the northern Edwards Plateau
and Concho Valley, to likely across the northern Big Country and
northwest Hill Country. Latest runs of the HRRR are optimistic in
a large area of showers and thunderstorms approaching our western
counties by late afternoon/early evening, but am reluctant to go
too high on PoPs at this time. The main threat with the convection
looks to be locally heavy rainfall and dangerous cloud to ground
lightning. Rain chances will quickly decrease from southwest to
northeast during the early morning hours Monday. Overnight lows
will be in the upper 50s to lower 60s.
.LONG TERM...
(Monday through Saturday)
Forecast challenges will be rain chances mainly Monday/Monday
night, and then again later in the week.
By Monday, the upper low over the Baja Peninsula this morning will
be moving into the southeastern NM/west Texas area. At the same
time, and cold front will be moving south through the Texas
Panhandle and western Oklahoma. The combination of these two
synoptic features will result in showers and thunderstorms
developing mainly along and ahead of the cold front Monday.
Showers and thunderstorms are most likely along and north of a
Sterling City to Brownwood line in the vicinity of the cold front.
Exactly where the cold front progresses to by Monday afternoon is
still in question however. So, with the front in the area,
increasing deep layer shear, and moderate instability in place
along/ahead of the cold front, it isn`t out of the question that
some of the thunderstorms that do develop could strengthen to
severe levels Monday afternoon and evening, especially along the
cold front. Severe weather hazards would be limited mainly to
large hail and damaging winds if it occurs. PoP values go from
`likely` (60%) in the Big Country, to slight chance and chance
(20-30%) along the I-10 corridor, based on the cold front stalling
near the Sterling City/Brownwood line in the afternoon. Rain
chances continue into the evening hours, mainly for the northern
half of the CWA, with decreasing rain chances Tuesday as the upper
level low moves off to the northeast away from the area.
Southwest flow returns Tuesday night into Wednesday with generally
dry weather across the area.
The next chance for rain begins Wednesday night into Thursday as
another low drops south through the Rocky Mountains into the four
corners region, then turns east, and moves across the Texas
panhandle region into the southern plains. Have kept a slight
chance to chance in the forecast from Wednesday night through
Thursday night for this feature. However, with very dry air aloft
rotating to the east around the south side of the upper level low,
there is some concern that the best precipitation chances would be
pushed to the east of our area.
Have kept the generally dry forecast going for the area from
Friday into Saturday. However, the latest run of the ECMWF is now
stalling the upper level low near the four corners region through
this time period resulting in additional rain chances. Will have
to keep an eye on model trends concerning this change, and update
the forecast as needed.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 81 59 75 55 72 / 20 50 60 50 20
San Angelo 80 58 79 55 75 / 40 50 40 20 10
Junction 80 60 79 56 78 / 40 60 30 20 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS PORTLAND
245 AM PDT SUN APR 12 2015
.SYNOPSIS...STILL A FEW SHOWERS AROUND REGION TODAY...BUT OVERALL A
DRY PLEASANT DAY. NEXT FRONT WILL ARRIVE ON MON...WITH INCREASING
CLOUDS IN THE MORNING...AND RAIN SPREADING ACROSS REGION IN
AFTERNOON. COOL AND SHOWERY ON TUE...THEN HIGH PRES BUILDS BRINGING
MILD DRY WEATHER FOR WED THROUGH FRI.
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT...
ONSHORE FLOW CONTINUES ACROSS THE PAC NW...WITH ISOLATED SHOWERS
PUSHING ONSHORE OVER WRN WASHINGTON AND FAR NW OREGON. WEAK HIGH PRES
WILL BUILD OVER THE REGION TODAY...WITH SHOWERS THREAT DECREASING AS
DAY PROGRESSES. BEST THREAT FOR A SHOWER WILL BE OVER WRN WASHINGTON.
DRY TONIGHT UNDER WEAK HIGH PRES.
CLOUDS WILL INCREASE MON AM AS NEXT FRONT FAST APPROACHES FROM THE
WEST. ALL MODELS IN FAIRLY GOOD AGREEMENT WITH TIMING OF RAIN. LOOKS
LIKE RAIN DEVELOPING ALONG THE COAST BY MID TO LATE MON AM... AND
RAIN SPREADING FURTHER INLAND IN THE AFTERNOON. FRONT SHOULD PUSH
ONSHORE LATE MON AFTERNOON TO EARLY EVENING...THEN TO CASCADES BY
LATE MON EVENING. DECENT SHOT OF RAINFALL...BUT SINCE FRONT MOVING
FAIRLY QUICKLY MOST AREAS WILL GET 0.25 TO 0.50 INCH OF RAIN WITH BIT
HEAVIER RAINFALL IN COAST RANGE AND CASCADES.
SNOW LEVELS WILL LOWER TO JUST BELOW PASSES MON NIGHT. BUT
UNFORTUNATELY...WILL BE SHOWERY PRECIPITATION BY THEN. STILL... WITH
CURRENT RAINFALL FORECASTS AND EXPECTED SNOW LEVELS... PROBABLY ONLY
GET 2 TO 6 INCHES OF SNOW IN THE CASCADES FOR MON NIGHT...AND ANOTHER
1 TO 3 INCHES ON TUE WITH DECREASING SHOWERS. WILL NOT ISSUE ANY
ADVISORIES FOR SNOW AT THIS TIME.
.LONG TERM...WEDNESDAY THROUGH SATURDAY...500 MB RIDGING RETURNS
WEDNESDAY...BUT ITS STRENGTH WILL BE IN QUESTION. THE 12Z ECMWF AND
GFS ARE QUITE SIMILAR...WITH THE 570 DM HEIGHT CONTOUR ALONG THE
COLUMBIA RIVER. BOTH MODELS SHOW SOME WARM-FRONTAL OVER-RUNNING
PRECIP CLOSE TO THE SW WA ZONES WED...BUT DID NOT MENTION ANY PRECIP
FOR THE CWA. MODEL DIFFERENCES START TO BECOME MORE APPARENT THU. THE
GFS HAS A WEAK SHORT-WAVE APPROACHING THE COAST THU AFTERNOON... WITH
STRENGTHENING ON-SHORE LOW-LEVEL FLOW. GFS ACTUALLY BRINGS THE .01
PRECIP CONTOUR TO THE FAR N OREGON COAST. THE ECMWF HAS A STRONGER
RIDGE...BUT OPTED TO LEAVE SLIGHT CHANCE POPS IN THE SW WA ZONES FOR
NOW. FRI AND SAT ARE MORE MUDDLED. GFS BRINGS THE SHORT-WAVE THROUGH
FRI MORNING...MORE INDICATIVE OF A STRONG MARINE SURGE. THE ECMWF
HOLDS ON TO ITS RIDGE MUCH OF FRI THEN FORMING A CLOSED 500 MB LOW
OFF THE S OREGON COAST 00Z SAT. HAVE LEANED TOWARD A DRY FORECAST
FRI-SAT...BUT CONFIDENCE IN GENERAL DETAILS REMAINS ON THE LOW END.
WEISHAAR
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED TO PREVAIL TODAY THOUGH
THERE MAY BE A FEW HOURS OF PATCHY FOG OR LOW STRATUS THIS
MORNING ESPECIALLY SOUTH OF KSLE WHERE THE MOST CLEARING AND
SURFACE RIDGE HAS DEVELOPED. A FEW SHOWERS LINGERING NORTH OF KSLE
WILL DECREASE THROUGH THE DAY. THE NEXT FRONT APPROACHES THE COAST
LATE TONIGHT.
KPDX AND APPROACHES...VFR CONDITIONS CONTINUE THROUGH THE PERIOD WITH
SCT-BKN MID CLOUD DECK AND LIGHT NEAR-SURFACE WINDS.
&&
.MARINE...WINDS HAVE SLOWLY EASED OVER THE WATERS OVERNIGHT...BUT
SOME OCCASIONAL GUSTS TO AROUND 25 KT ASSOCIATED WITH SOME
LINGERING SHOWER ACTIVITY WILL REMAIN FOR THE EARLY MORNING HOURS.
ANOTHER ROUND OF SMALL CRAFT ADVISORY WINDS WILL BEGIN LATE SUN
NIGHT AND CONTINUE INTO MONDAY WITH THE NEXT FRONTAL SYSTEM THAT
WILL CROSS THE WATERS. CONFIDENCE IN THE PRECISE THE DURATION AND
TIMING OF STRONGEST WINDS REMAINS A BIT LOWER THAN NORMAL DUE TO
SOME SIGNIFICANT DIFFERENCES AMONG FORECAST MODELS...BUT EXPECT
PEAK GUSTS AROUND 25 KT.
A WEST SWELL IN THE 10 TO 12 FT RANGE WILL CONTINUE TODAY AND
SHOULD BE JUST UNDER 10 FT LATE THIS EVENING...THEN BACK UP TO
NEAR 11 FT MONDAY. A MORE SIGNIFICANT SWELL MAY ARRIVE BY THE
SECOND HALF OF NEXT WEEK WITH SEAS BUILDING IN THE 10 TO 15 FT
RANGE THU. MODELS INDICATING A FAIRLY LONG PERIOD OF 18 TO 20
SECONDS ON THU.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS TODAY THROUGH
THIS EVENING ON ALL COASTAL WATERS.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA BAR CONDITIONS
FOR TODAY.
&&
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
228 AM PDT SUN APR 12 2015
.SYNOPSIS...
A few lingering mountain snow showers today will give way to a
quiet and mild day on Monday. A cold front will pass through the
area Monday night bringing a return to unsettled weather including
breezy conditions and scattered showers. Wednesday and Thursday
will be dry and increasingly mild. Another weak cold front is
possible on or about Friday.
&&
.DISCUSSION...
Today and tonight...Flat progressive zonal flow with a somewhat
conditionally airmass remaining in place for today leaves minor
pops along the east and west edges of the forecast area and a
break in both precipitation and clouds in between courtesy of the
zonal westerly flow downsloping off the Cascades. Weak ridging
occurs tonight allowing for further drying and lowering of pops
along the edges. Cloud cover will remain rather cluttered as both
the zonal flow and the weak ridging is not enough to push the
moisture streaming through it too far away from the area. Forecast
temperatures remain slightly on the cool side of what would be
considered normal for this time of year but are slightly warmer in
comparison to those reached yesterday and last night. /Pelatti
Monday through Saturday...Good model agreement exists between the
latest GFS and EC models through Thursday. Confidence is high of a
dry and mild day on Monday...followed by another showery and windy
cold front passage Monday night and Tuesday.
This system will be the main impact issue through the rest of the
week. Models are settling on a timing solution featuring
widespread rain showers over the eastern half of the forecast area
overnight Monday as the main front pushes through. Strong
downslope off the Cascades will probably lead to an essentially
dry but windy frontal passage over the western zones. Post
frontal cooling by Tuesday morning will change residual showers
into snow showers down to valley floors in the morning and through
the day over the high terrain of the idaho Panhandle. Little or no
valley/basin accumulation is expected but the mountains of Idaho
could pick up 2 to 4 inches above 400 feet and may affect travel
across Lookout Pass with slippery conditions.
Winds will be the main issue across the basin. The gradient and
gust potential from mixing suggest solidly breezy to windy
conditions but sub-advisory criteria...much like yesterday`s
conditions. Temperatures on Tuesday will also ratchet back to
below normal in this showery and cooler air mass.
For the rest of the week things look pretty benign with decreasing
winds and a weak ridge aloft for Wednesday and Thursday as
temperatures climb back to normal or slightly above.
Friday presents the lowest confidence model dilemma...with the GFS
insisting for multiple runs on another weaker cold front
passage...this one with only marginal shower and slightly
increased wind potential...while the ECMWF features the parent wave
energy missing the area entirely by forming a split offshore and
keeping the forecast area dry and benign. The GFS is more
consistent and thus will bet on a weak frontla passage on or about
Friday...followed by another benign break period on Saturday.
/Fugazzi
&&
.AVIATION...
06Z TAFS: Lingering showers will continue over the Cascade crest
and over the higher terrain in the ID Panhandle. This will result
in mountain obscurations through tonight. Low stratus is expected
to form over the Palouse after 10Z and linger through the early
morning hours on Sunday. This will result in MVFR cigs at KPUW
with moderate confidence in the forecast. Southwest boundary layer
winds may advect this low level moisture toward the Spokane/Coeur
d`Alene corridor with MVFR cigs possible at KGEG, KSFF and KCOE,
but confidence is not as high as at KPUW. Winds will steadily
decrease through tonight into Sunday as pressure gradients weaken.
/SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 49 34 62 38 48 32 / 10 0 0 60 50 10
Coeur d`Alene 49 31 64 38 48 31 / 10 0 10 80 60 20
Pullman 49 33 64 38 46 31 / 10 0 10 80 60 30
Lewiston 56 35 73 44 54 36 / 10 0 10 80 50 40
Colville 52 31 63 39 52 31 / 10 0 10 60 50 10
Sandpoint 48 28 62 37 48 30 / 10 0 10 80 70 20
Kellogg 45 31 63 37 43 29 / 30 0 10 90 80 30
Moses Lake 56 34 64 39 55 34 / 0 0 0 10 10 10
Wenatchee 56 37 62 43 54 36 / 0 0 10 10 10 10
Omak 54 31 63 37 55 30 / 10 0 10 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
228 AM PDT SUN APR 12 2015
.SYNOPSIS...
A few lingering mountain snow showers today will give way to a
quiet and mild day on Monday. A cold front will pass through the
area Monday night bringing a return to unsettled weather including
breezy conditions and scattered showers. Wednesday and Thursday
will be dry and increasingly mild. Another weak cold front is
possible on or about Friday.
&&
.DISCUSSION...
Today and tonight...Flat progressive zonal flow with a somewhat
conditionally airmass remaining in place for today leaves minor
pops along the east and west edges of the forecast area and a
break in both precipitation and clouds in between courtesy of the
zonal westerly flow downsloping off the Cascades. Weak ridging
occurs tonight allowing for further drying and lowering of pops
along the edges. Cloud cover will remain rather cluttered as both
the zonal flow and the weak ridging is not enough to push the
moisture streaming through it too far away from the area. Forecast
temperatures remain slightly on the cool side of what would be
considered normal for this time of year but are slightly warmer in
comparison to those reached yesterday and last night. /Pelatti
Monday through Saturday...Good model agreement exists between the
latest GFS and EC models through Thursday. Confidence is high of a
dry and mild day on Monday...followed by another showery and windy
cold front passage Monday night and Tuesday.
This system will be the main impact issue through the rest of the
week. Models are settling on a timing solution featuring
widespread rain showers over the eastern half of the forecast area
overnight Monday as the main front pushes through. Strong
downslope off the Cascades will probably lead to an essentially
dry but windy frontal passage over the western zones. Post
frontal cooling by Tuesday morning will change residual showers
into snow showers down to valley floors in the morning and through
the day over the high terrain of the idaho Panhandle. Little or no
valley/basin accumulation is expected but the mountains of Idaho
could pick up 2 to 4 inches above 400 feet and may affect travel
across Lookout Pass with slippery conditions.
Winds will be the main issue across the basin. The gradient and
gust potential from mixing suggest solidly breezy to windy
conditions but sub-advisory criteria...much like yesterday`s
conditions. Temperatures on Tuesday will also ratchet back to
below normal in this showery and cooler air mass.
For the rest of the week things look pretty benign with decreasing
winds and a weak ridge aloft for Wednesday and Thursday as
temperatures climb back to normal or slightly above.
Friday presents the lowest confidence model dilemma...with the GFS
insisting for multiple runs on another weaker cold front
passage...this one with only marginal shower and slightly
increased wind potential...while the ECMWF features the parent wave
energy missing the area entirely by forming a split offshore and
keeping the forecast area dry and benign. The GFS is more
consistent and thus will bet on a weak frontla passage on or about
Friday...followed by another benign break period on Saturday.
/Fugazzi
&&
.AVIATION...
06Z TAFS: Lingering showers will continue over the Cascade crest
and over the higher terrain in the ID Panhandle. This will result
in mountain obscurations through tonight. Low stratus is expected
to form over the Palouse after 10Z and linger through the early
morning hours on Sunday. This will result in MVFR cigs at KPUW
with moderate confidence in the forecast. Southwest boundary layer
winds may advect this low level moisture toward the Spokane/Coeur
d`Alene corridor with MVFR cigs possible at KGEG, KSFF and KCOE,
but confidence is not as high as at KPUW. Winds will steadily
decrease through tonight into Sunday as pressure gradients weaken.
/SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 49 34 62 38 48 32 / 10 0 0 60 50 10
Coeur d`Alene 49 31 64 38 48 31 / 10 0 10 80 60 20
Pullman 49 33 64 38 46 31 / 10 0 10 80 60 30
Lewiston 56 35 73 44 54 36 / 10 0 10 80 50 40
Colville 52 31 63 39 52 31 / 10 0 10 60 50 10
Sandpoint 48 28 62 37 48 30 / 10 0 10 80 70 20
Kellogg 45 31 63 37 43 29 / 30 0 10 90 80 30
Moses Lake 56 34 64 39 55 34 / 0 0 0 10 10 10
Wenatchee 56 37 62 43 54 36 / 0 0 10 10 10 10
Omak 54 31 63 37 55 30 / 10 0 10 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
228 AM PDT SUN APR 12 2015
.SYNOPSIS...
A few lingering mountain snow showers today will give way to a
quiet and mild day on Monday. A cold front will pass through the
area Monday night bringing a return to unsettled weather including
breezy conditions and scattered showers. Wednesday and Thursday
will be dry and increasingly mild. Another weak cold front is
possible on or about Friday.
&&
.DISCUSSION...
Today and tonight...Flat progressive zonal flow with a somewhat
conditionally airmass remaining in place for today leaves minor
pops along the east and west edges of the forecast area and a
break in both precipitation and clouds in between courtesy of the
zonal westerly flow downsloping off the Cascades. Weak ridging
occurs tonight allowing for further drying and lowering of pops
along the edges. Cloud cover will remain rather cluttered as both
the zonal flow and the weak ridging is not enough to push the
moisture streaming through it too far away from the area. Forecast
temperatures remain slightly on the cool side of what would be
considered normal for this time of year but are slightly warmer in
comparison to those reached yesterday and last night. /Pelatti
Monday through Saturday...Good model agreement exists between the
latest GFS and EC models through Thursday. Confidence is high of a
dry and mild day on Monday...followed by another showery and windy
cold front passage Monday night and Tuesday.
This system will be the main impact issue through the rest of the
week. Models are settling on a timing solution featuring
widespread rain showers over the eastern half of the forecast area
overnight Monday as the main front pushes through. Strong
downslope off the Cascades will probably lead to an essentially
dry but windy frontal passage over the western zones. Post
frontal cooling by Tuesday morning will change residual showers
into snow showers down to valley floors in the morning and through
the day over the high terrain of the idaho Panhandle. Little or no
valley/basin accumulation is expected but the mountains of Idaho
could pick up 2 to 4 inches above 400 feet and may affect travel
across Lookout Pass with slippery conditions.
Winds will be the main issue across the basin. The gradient and
gust potential from mixing suggest solidly breezy to windy
conditions but sub-advisory criteria...much like yesterday`s
conditions. Temperatures on Tuesday will also ratchet back to
below normal in this showery and cooler air mass.
For the rest of the week things look pretty benign with decreasing
winds and a weak ridge aloft for Wednesday and Thursday as
temperatures climb back to normal or slightly above.
Friday presents the lowest confidence model dilemma...with the GFS
insisting for multiple runs on another weaker cold front
passage...this one with only marginal shower and slightly
increased wind potential...while the ECMWF features the parent wave
energy missing the area entirely by forming a split offshore and
keeping the forecast area dry and benign. The GFS is more
consistent and thus will bet on a weak frontla passage on or about
Friday...followed by another benign break period on Saturday.
/Fugazzi
&&
.AVIATION...
06Z TAFS: Lingering showers will continue over the Cascade crest
and over the higher terrain in the ID Panhandle. This will result
in mountain obscurations through tonight. Low stratus is expected
to form over the Palouse after 10Z and linger through the early
morning hours on Sunday. This will result in MVFR cigs at KPUW
with moderate confidence in the forecast. Southwest boundary layer
winds may advect this low level moisture toward the Spokane/Coeur
d`Alene corridor with MVFR cigs possible at KGEG, KSFF and KCOE,
but confidence is not as high as at KPUW. Winds will steadily
decrease through tonight into Sunday as pressure gradients weaken.
/SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 49 34 62 38 48 32 / 10 0 0 60 50 10
Coeur d`Alene 49 31 64 38 48 31 / 10 0 10 80 60 20
Pullman 49 33 64 38 46 31 / 10 0 10 80 60 30
Lewiston 56 35 73 44 54 36 / 10 0 10 80 50 40
Colville 52 31 63 39 52 31 / 10 0 10 60 50 10
Sandpoint 48 28 62 37 48 30 / 10 0 10 80 70 20
Kellogg 45 31 63 37 43 29 / 30 0 10 90 80 30
Moses Lake 56 34 64 39 55 34 / 0 0 0 10 10 10
Wenatchee 56 37 62 43 54 36 / 0 0 10 10 10 10
Omak 54 31 63 37 55 30 / 10 0 10 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
228 AM PDT SUN APR 12 2015
.SYNOPSIS...
A few lingering mountain snow showers today will give way to a
quiet and mild day on Monday. A cold front will pass through the
area Monday night bringing a return to unsettled weather including
breezy conditions and scattered showers. Wednesday and Thursday
will be dry and increasingly mild. Another weak cold front is
possible on or about Friday.
&&
.DISCUSSION...
Today and tonight...Flat progressive zonal flow with a somewhat
conditionally airmass remaining in place for today leaves minor
pops along the east and west edges of the forecast area and a
break in both precipitation and clouds in between courtesy of the
zonal westerly flow downsloping off the Cascades. Weak ridging
occurs tonight allowing for further drying and lowering of pops
along the edges. Cloud cover will remain rather cluttered as both
the zonal flow and the weak ridging is not enough to push the
moisture streaming through it too far away from the area. Forecast
temperatures remain slightly on the cool side of what would be
considered normal for this time of year but are slightly warmer in
comparison to those reached yesterday and last night. /Pelatti
Monday through Saturday...Good model agreement exists between the
latest GFS and EC models through Thursday. Confidence is high of a
dry and mild day on Monday...followed by another showery and windy
cold front passage Monday night and Tuesday.
This system will be the main impact issue through the rest of the
week. Models are settling on a timing solution featuring
widespread rain showers over the eastern half of the forecast area
overnight Monday as the main front pushes through. Strong
downslope off the Cascades will probably lead to an essentially
dry but windy frontal passage over the western zones. Post
frontal cooling by Tuesday morning will change residual showers
into snow showers down to valley floors in the morning and through
the day over the high terrain of the idaho Panhandle. Little or no
valley/basin accumulation is expected but the mountains of Idaho
could pick up 2 to 4 inches above 400 feet and may affect travel
across Lookout Pass with slippery conditions.
Winds will be the main issue across the basin. The gradient and
gust potential from mixing suggest solidly breezy to windy
conditions but sub-advisory criteria...much like yesterday`s
conditions. Temperatures on Tuesday will also ratchet back to
below normal in this showery and cooler air mass.
For the rest of the week things look pretty benign with decreasing
winds and a weak ridge aloft for Wednesday and Thursday as
temperatures climb back to normal or slightly above.
Friday presents the lowest confidence model dilemma...with the GFS
insisting for multiple runs on another weaker cold front
passage...this one with only marginal shower and slightly
increased wind potential...while the ECMWF features the parent wave
energy missing the area entirely by forming a split offshore and
keeping the forecast area dry and benign. The GFS is more
consistent and thus will bet on a weak frontla passage on or about
Friday...followed by another benign break period on Saturday.
/Fugazzi
&&
.AVIATION...
06Z TAFS: Lingering showers will continue over the Cascade crest
and over the higher terrain in the ID Panhandle. This will result
in mountain obscurations through tonight. Low stratus is expected
to form over the Palouse after 10Z and linger through the early
morning hours on Sunday. This will result in MVFR cigs at KPUW
with moderate confidence in the forecast. Southwest boundary layer
winds may advect this low level moisture toward the Spokane/Coeur
d`Alene corridor with MVFR cigs possible at KGEG, KSFF and KCOE,
but confidence is not as high as at KPUW. Winds will steadily
decrease through tonight into Sunday as pressure gradients weaken.
/SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 49 34 62 38 48 32 / 10 0 0 60 50 10
Coeur d`Alene 49 31 64 38 48 31 / 10 0 10 80 60 20
Pullman 49 33 64 38 46 31 / 10 0 10 80 60 30
Lewiston 56 35 73 44 54 36 / 10 0 10 80 50 40
Colville 52 31 63 39 52 31 / 10 0 10 60 50 10
Sandpoint 48 28 62 37 48 30 / 10 0 10 80 70 20
Kellogg 45 31 63 37 43 29 / 30 0 10 90 80 30
Moses Lake 56 34 64 39 55 34 / 0 0 0 10 10 10
Wenatchee 56 37 62 43 54 36 / 0 0 10 10 10 10
Omak 54 31 63 37 55 30 / 10 0 10 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
1049 PM PDT SAT APR 11 2015
.SYNOPSIS...
A cold front has moved through the region leaving unsettled
weather this afternoon. Widespread showers accompanied by breezy
conditions will give way to a ridge of high pressure Sunday.
Another front will approach the area Monday night bringing a
return to unsettled weather including breezy conditions and
scattered afternoon/evening showers.
&&
.DISCUSSION...
Early evening update to remove thunderstorms and to increase snow
amounts over Stevens Pass. Chances for precip were also increased
a little bit in the lower portion of the Upper Columbia Basin and
into the Palouse where a weak convergence zone is located. Not
enough instability was generated this afternoon to see much in the
way of any thunderstorm activity. There were a few lightning
strikes just north of the border of the Northern Panhandle, but
chances of seeing any thunderstorms this evening anywhere across
the Inland Northwest is minimal.
The focus for this evening will turn to the Cascade crest where a
Puget Sound Convergence zone has set up over Stevens Pass. Latest
web cams at 600 PM show snow accumulating over the pass. It looks
as if the snow accumulated rather rapidly, which is characteristic
of these convergence zones. The HRRR model seems to be handling
this rather well and shows this convergence zone strengthening
over the next few hours through at least 900 PM this evening. Any
travelers heading over Stevens Pass this evening should prepare
for heavy snow with rapid changes to visibility. Snowfall rates of
between 1-1.5 inches will easily be possible. The HRRR model does
show this convergence zone weakening by 1000 PM and possibly
shifting a little bit north of Stevens Pass. However, light snow
showers are expected to persist through tonight. We will handle
this situation with NOWCasts for now and provide updates on our
social media pages when possible. Traditional highlights are not
expected at this time as it will be a fairly localized event and
primarily only impact travel over Stevens Pass. /SVH
&&
.AVIATION...
06Z TAFS: Lingering showers will continue over the Cascade crest
and over the higher terrain in the ID Panhandle. This will result
in mountain obscurations through tonight. Low stratus is expected
to form over the Palouse after 10Z and linger through the early
morning hours on Sunday. This will result in MVFR cigs at KPUW
with moderate confidence in the forecast. Southwest boundary layer
winds may advect this low level moisture toward the Spokane/Coeur
d`Alene corridor with MVFR cigs possible at KGEG, KSFF and KCOE,
but confidence is not as high as at KPUW. Winds will steadily
decrease through tonight into Sunday as pressure gradients weaken.
/SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 32 49 36 62 37 50 / 20 10 0 0 60 50
Coeur d`Alene 31 49 33 64 36 49 / 30 10 0 10 80 60
Pullman 32 49 36 64 36 48 / 40 10 0 10 80 50
Lewiston 35 56 38 70 43 53 / 20 10 0 10 70 50
Colville 31 52 33 61 38 54 / 40 10 0 10 40 50
Sandpoint 32 48 30 60 35 49 / 50 10 0 10 80 70
Kellogg 30 45 33 63 36 44 / 50 30 0 10 90 70
Moses Lake 33 56 36 64 37 56 / 10 0 0 0 10 10
Wenatchee 35 56 40 62 40 54 / 20 0 0 10 10 10
Omak 30 54 33 61 34 55 / 10 10 0 10 20 20
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
325 PM CDT SUN APR 12 2015
.SHORT TERM...
TONIGHT...FORECAST CONFIDENCE MEDIUM.
INITIAL MORE COMPACT VORT HEADING ENE THROUGH ERN IA/NRN IL. SHOWS
UP WELL ON WATER VAPOR/RUC COMBO WITH DECENT AMOUNT OF ENHANCEMENT
ON IR IMAGERY. LOW LEVEL FLOW WILL REMAIN SOUTHERLY AHEAD OF THE
MAIN TROUGH APPROACHING FROM THE PLAINS. HRRR BRINGS LIGHT QPF INTO
THE SRN CWA THIS EVENING AND WILL HAVE SOME POPS TO ACCOUNT FOR
THIS. WAS GOING TO GO WITH HIGHER HRRR/CONSSHORT POPS BUT PER COLLAB
WITH KLOT THE LINGERING DRY AIR AND 30 DEGREE DEW POINT DEPRESSIONS
MAY HAVE A SAY IN HOW FAR NE THIS INITIAL AREA IS ABLE TO ADVANCE.
HAVE NOW GONE AHEAD AND BOOSTED POPS FURTHER IN THE SOUTHWEST CWA AS
PRECIP SPREADING IN AND KDBQ REPORTING LIGHT RAIN. HIGHER DEWS
LIKELY TO ADVECT NEWD WITH TIME. NEXT FOCUS WILL BE PRECIP WITH
PRIMARY UPPER WAVE AND LOW LEVEL TROUGH. THIS IS STILL LARGELY ON
TRACK TO SWEEP THROUGH LATER TONIGHT AND EARLY MONDAY IN THE FAR
EAST. ELEVATED CAPE IS RATHER MARGINAL BUT STILL SOME SO OPTED TO
LEAVE MENTION OF THUNDER. TEMPS TO STAY MILD OVERNIGHT WITH
SOUTHERLY FLOW AND CLOUD COVER.
MONDAY...FORECAST CONFIDENCE MEDIUM.
SYSTEM PULLS EAST EARLY MONDAY WITH MAIN STORY BEING THE DRY AND
GUSTY WESTERLY FLOW SETTING UP. 925 TEMPS SUPPORT TEMPS INTO THE
60S SO NOT MUCH CHANGE IN AIRMASS BEHIND DEPARTED TROUGH. ANY
CLOUDS ASSOCIATED WITH TROUGH SHOULD CLEAR OUT FAIRLY QUICK DURING
THE MORNING HOURS.
MONDAY NIGHT THROUGH WEDNESDAY...FORECAST CONFIDENCE HIGH.
HIGH PRESSURE OVER THE CENTRAL PLAINS ON MONDAY WILL MOVE TO SRN
WI AND NRN IL BY 12Z TUE AND REACH LOWER MI BY 00Z WED. RIDGING
ALOFT WILL ENSUE DURING THIS PERIOD AS AN UPPER TROUGH MOVES
ACROSS THE PACIFIC NW. A VERY DRY AIRMASS AND ABUNDANT SUNSHINE WILL
ALLOW TEMPS TO WARM WELL INTO THE 60S AWAY FROM THE EASTERN ONE
THIRD OF THE CWA WHERE A LAKE BREEZE IS EXPECTED.
AN INCREASING ESELY FLOW IS EXPECTED FOR WED AS HIGH PRESSURE
CONTINUES TO THE EAST AND CYCLOGENESIS ENSUES OVER SE CO. A
SHORTWAVE TROUGH WILL TRACK FROM TX TO THE MID MO RIVER VALLEY AND
MID MS RIVER VALLEY BY 00Z THU. HIGH CLOUDS FROM THE APPROACHING SHORTWAVE
TROUGH AND MORE OF AN ELY FLOW WILL SUPPORT COOLER TEMPS ON WED ESPECIALLY
OVER ERN WI VIA THE COLD LAKE.
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE
MEDIUM.
A SHORTWAVE TROUGH AND WEAK LOW PRESSURE AREA WILL MOVE ACROSS THE
OHIO RIVER VALLEY WED NT AND THU BUT WILL ALSO BE SUFFICIENTLY
CLOSE TO SRN WI TO MAINTAIN CHANCES OF LGT RAIN. AN UPPER TROUGH
WILL THEN MOVE ACROSS THE NRN GREAT LAKES FRI NT WITH A COLD
FRONTAL PASSAGE EXPECTED OVER SRN WI. LITTLE TO NO RAIN IS
EXPECTED WITH THESE FEATURES. HIGH PRESSURE TO THEN FOLLOW FOR SAT
WITH SLY FLOW AND WARM ADVECTION DEVELOPING FOR SUNDAY AS UPPER
TROUGHING APPROACHES FROM THE PLAINS. ABOVE NORMAL TEMPS TO
CONTINUE THROUGH THIS PERIOD.
&&
.AVIATION/00Z TAFS/...COUPLE DIFFERENT FEATURES TO CONTEND WITH THIS
PERIOD. ONE ARRIVES THIS EVENING. COMPACT WAVE LIFTING ENE FROM ERN
IA. HRRR SUGGESTS SOME LIGHT RAIN COMES ACROSS LATE THIS
AFTN/EVE...THEN A BREAK BEFORE PLAINS TROUGH SWINGS THROUGH LATER
TONIGHT INTO MONDAY MORNING. EXPECT SHRA/ISOLD TSRA WITH THIS
FEATURE. SOME MVFR CIGS/VSBYS LIKELY. THEN GUSTY WEST WIND REGIME
TAKES HOLD MONDAY WITH MORNING CLEARING.
&&
.MARINE...NO CHANGE TO SMALL CRAFT HEADLINE. GUSTY SOUTH/SOUTHEAST
WINDS AHEAD OF TROUGH...WITH A POTENTIAL LULL TONIGHT WITH TROUGH
PASSAGE TONIGHT...THEN WEST WINDS RAMP BACK UP ON MONDAY. HIGHEST
WAVE ACTION WILL SHIFT TOWARDS OPEN WATERS ON MONDAY WITH THE
OFFSHORE FLOW.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM CDT MONDAY FOR LMZ643>646.
&&
$$
TONIGHT/MONDAY AND AVIATION/MARINE...COLLAR
MONDAY NIGHT THROUGH SUNDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1205 PM CDT SUN APR 12 2015
.UPDATE...
ISSUED AT 444 AM CDT SUN APR 12 2015
SCATTERED SHOWERS AND EVEN A FEW LIGHTNING STRIKES HAVE DEVELOPED
ACROSS CENTRAL IA EARLY THIS MORNING AND ARE MOVING TO THE
NORTHEAST AROUND 25 KTS. LATEST HRRR HAS PICKED UP ON THESE TRENDS
AND WILL FOLLOW ITS SOLUTION FOR THE MORNING HOURS...RESULTING IN
SCATTERED SHOWERS MOVING INTO SOUTHEAST MN AND FAR WESTERN WI. SPC
MESO-ANALYSIS SHOWS NO INSTABILITY ACROSS THE AREA...BUT WITH A
FEW REPORTED LIGHTNING STRIKES...WILL ADD ISOLATED THUNDER AS
WELL. ANY ACCUMULATION WILL BE MINIMAL.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT SUN APR 12 2015
CHALLENGES INCLUDE WIND AND TEMPERATURES TODAY...FOLLOWED BY
SHOWER AND THUNDERSTORM CHANCES/TIMING THIS EVENING AND OVERNIGHT.
12.00Z GLOBAL MODEL SUITE IN GOOD AGREEMENT...BUT WILL FOLLOW
RAP/HRRR GUIDANCE FOR TIMING OF TONIGHT/S CONVECTION.
TODAY WILL BE WARM AND WINDY AHEAD OF A SURFACE TROUGH AND COLD
FRONT THAT MOVE THROUGH THE REGION LATER THIS EVENING AND OVERNIGHT.
CLEAR SKIES EARLY THIS MORNING WILL GIVE WAY TO INCREASING CLOUD
COVER THROUGH THE DAY ASSOCIATED WITH A LEADING SHORT-WAVE CURRENTLY
OVER NE/KS. SOME OF ITS SHOWER AND THUNDERSTORM ACTIVITY COULD
CLIP THE SOUTHERNMOST FORECAST AREA LATE THIS MORNING AND AFTERNOON
AS THE WAVE MOVES ACROSS NORTHERN MO/SOUTHERN IA...BUT THE REST OF
THE AREA WILL REMAIN DRY. 925 HPA TEMPERATURES RISE TO AROUND +12
CELSIUS THIS AFTERNOON...BUT CLOUD COVER SHOULD HELP LIMIT FULL
WARMING POTENTIAL WITH HIGHS IN THE MID TO UPPER 60S. HOWEVER...
TEMPERATURES INTO THE LOWER 70S ARE POSSIBLE MAINLY ACROSS SOUTHEAST
MN AND NORTHEAST IA IF MORE SUN THAN CLOUDS ARE REALIZED.
BIGGER CONCERN TODAY IS STRONG SOUTHERLY WINDS. AFTERNOON BOUNDARY
LAYER DEEPENS TO BETWEEN 800 AND 850 HPA WITH ROUGHLY 35 TO 40 KTS
TO MIX TO THE SURFACE. THIS WILL RESULT IN SUSTAINED WINDS FROM 20
TO 30 MPH WITH GUSTS UP TO 35 MPH. COULD SEE BRIEF WIND ADVISORY
CONDITIONS ACROSS WIND PRONE AREAS OF SOUTHEAST MN AND NORTHEAST
IA...BUT NOT ENOUGH CONFIDENCE AT THIS TIME TO ISSUE AN ADVISORY.
STRONG SOUTHERLY WIND WILL ADVECT MOISTURE NORTHWARD...RESULTING
IN DEW POINT TEMPERATURES RISING INTO THE 40S AND KEEPING MINIMUM
RH VALUES 40 PERCENT OR HIGHER.
COLD FRONT WILL APPROACH I-35 CORRIDOR BY 00Z TONIGHT AND THEN
SWEEP ACROSS THE UPPER MS RIVER VALLEY THIS EVENING INTO EARLY
MONDAY MORNING. STRONG WARMING IN THE 1-2 KM LAYER THIS EVENING
AHEAD OF THE FRONT WILL SQUASH ANY SURFACE BASED CONVECTION...BUT
MODEL SOUNDINGS DO SHOW 200 TO 500 J/KG OF ELEVATED SKINNY CAPE. 0
TO 6 KM BULK SHEAR INCREASES TO BETWEEN 30 AND 40 KTS LATER THIS
EVENING...BUT MOST OF THIS IS IN THE LOWEST COUPLE KILOMETERS. NOT
EXPECTING ANY SEVERE WEATHER AT THIS TIME...BUT COULD STILL SEE
SOME SMALL HAIL COMBINED WITH LIGHTNING AND BRIEF HEAVY DOWNPOURS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 352 AM CDT SUN APR 12 2015
SURFACE HIGH PRESSURE CENTER MOVES QUICKLY INTO NE/IA FOR MONDAY...
KEEPING THE FORECAST AREA WITHIN STRONGER PRESSURE GRADIENT ALONG
NORTHERN FLANK. AS A RESULT...EXPECT BREEZY NORTHWEST WIND WITH
SOME GUSTS UP TO 30 MPH. SKIES WILL BE MOSTLY SUNNY...BUT WITH
SLIGHTLY COOLER AIR MASS IN THE WAKE OF THE COLD FRONT...
AFTERNOON HIGHS WILL BE IN THE UPPER 50S TO LOWER 60S. IN
ADDITION...DRIER AIR MASS WILL ALLOW RELATIVE HUMIDITY TO DROP
INTO THE 25 TO 30 PERCENT RANGE.
DRY AND WARM CONDITIONS TO CONTINUE TUESDAY AND WEDNESDAY WITH
OCCASIONAL SOUTHERLY BREEZES AS 500 HPA RIDGE AXIS MOVES ACROSS
THE NATION/S MID-SECTION. DAILY HIGHS WILL RISE INTO THE MID TO
UPPER 60S WITH LOWS FROM THE MID 30S TO LOWER 40S.
LOW PRECIP CHANCES INCREASE WEDNESDAY NIGHT AND CONTINUE THROUGH
FRIDAY AS A COUPLE NORTHERN STREAM SHORT-WAVES MOVE ALONG THE
INTERNATIONAL BORDER. HOWEVER...WITH 500 HPA CLOSED LOW NOW
STALLING ACROSS THE SOUTHERN ROCKIES AND NOT PHASING WITH NORTHERN
SYSTEMS...NOT LOOKING AT ANY PROLONGED HEAVY RAIN. IN FACT...
INSTABILITY HAS ALL BUT DISAPPEARED...SO REMOVED ANY THUNDER
MENTION FOR THE LATTER HALF OF THE WEEK. EXPECT A RETURN TO DRY
CONDITIONS BY THE START OF NEXT WEEKEND. SEASONAL TEMPERATURES
WILL CONTINUE WITH DAILY HIGHS IN THE 60S AND LOWS IN THE UPPER
30S/LOWER 40S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1205 PM CDT SUN APR 12 2015
VFR CONDITIONS THRU THIS AFTERNOON IN SOUTHERLY FLOW AHEAD OF A COLD
FRONT DUE IN THIS EVENING. CLOUDS THIS AFTERNOON LOOKING TO BE SCT
LCL BKN 8K-10K FT...WITH SOUTH WINDS 15-23KT G26-32KT. WINDS
DIMINISH WITH SUNSET AND CLOUD DECKS LOWER AS THE FRONT APPROACHES
THIS EVENING. BAND OF SHRA/TSRA EXPECTED TO BE APPROACHING SOUTHEAST
MN AT MID EVENING...BUT WHAT LIMITED INSTABILITY THERE IS LOOKS TO
BE WANING AT THE SHRA/TSRA WOULD MOVE INTO/ACROSS THE TAF SITES.
ONLY CARRIED A VCTS FROM 04-06Z AT KRST AND REMOVED MENTION OF
TSRA/CB FROM KLSE. PERIOD OF MVFR CIGS LOOKS TO ACCOMPANY THE BAND
OF PRECIP ACROSS THE TAF SITES...WITH THIS QUICKLY IMPROVING ONCE
THE FRONT PASSES...AROUND 06Z AT KRST AND 08Z AT KLSE.
GOOD VFR/SKC THEN EXPECTED FOR LATE TONIGHT/MON MORNING AS DRY HIGH
PRESSURE BUILDS IN BEHIND THE FRONT. TIGHTER GRADIENT AGAIN MON...
WITH BRISK/GUSTY NORTHEAST WINDS DEVELOPING AFTER 14-15Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE.......ROGERS
SHORT TERM...ROGERS
LONG TERM....ROGERS
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1011 AM CDT SUN APR 12 2015
.AVIATION/18Z TAFS/...LEAD SHORTWAVE AND WEAK MOISTURE ADVECTION
GENERATING A FEW SHRA ACROSS IA WITH STEADIER RAINS ACROSS NRN MO
CLOSER TO MAIN FORCING OF VORT CENTER. LATEST HRRR HAS BACKED OFF
FURTHER ON ANY ARRIVING PCPN UNTIL AFTER 21Z OR SO INTO FAR SRN
WI. EARLIER RUNS WERE QUICKER ON BRINGING PRECIP IN. RAP SOUNDINGS
ARE REALLY QUITE DRY SO FOR TAF PURPOSES WILL HOLD OFF AND KEEP
PCPN CONFINED TO THE OVERNIGHT PORTIONS DUE TO LINGERING INFLUENCE
OF DRY AIRMASS AND LOW LEVEL ANTICYCLONIC FEE. PRIMARY SHORTWAVE
AND DEEPER MOISTURE ADVECTION COINCIDE TONIGHT TO PRODUCE BEST
RAIN CHCS. ANY SHRA ASSOCIATED WITH THE TROUGH WILL QUICKLY
DEPART MONDAY MORNING WITH GUSTY WEST WINDS/DRYING AND NVA TAKING
HOLD.
PC
&&
.PREV DISCUSSION... /ISSUED 547 AM CDT SUN APR 12 2015/
TODAY...FORECAST CONFIDENCE MEDIUM
MODELS HAVE SLOWED TIMING OF FRONT...THOUGH STILL BRING SOME LIGHT
QPF ACROSS THE SOUTHERN CWA THIS AFTERNOON WITH FORCING FROM LEAD
SHORT WAVE. MODEL SOUNDINGS AND CROSS SECTIONS SHOW BETTER MOISTURE
OVER THE SOUTHWEST SO WILL HAVE SLIGHTLY HIGHER POPS THERE BUT STILL
CHANCE CATEGORY. WORRIED THAT DRY LAYER BELOW 6K-7K FT WILL LIMIT
AMOUNTS. MINIMAL INSTABILITY WITH LITTLE TO NO CAPE...BUT WILL HAVE
A COLLABORATIVE SLIGHT CHANCE OF THUNDER IN THE FAR SOUTHWEST WHERE
MID-LEVEL LAPSE RATES ARE A BIT STEEPER.
BREEZY BY LATE MORNING/EARLY AFTERNOON WITH MIXING UP TO 30 KNOT
WINDS. BUMPED TEMPS UP A COUPLE OF DEGREES WITH THIS DEEPER MIXING
THOUGH LITTLE CHANGE IN THE SW WHERE CLOUDS MOVE IN EARLIER AND WILL
LIMIT HIGHS.
TONIGHT...FORECAST CONFIDENCE HIGH
MAY BE A BREAK IN THE SHOWERS BETWEEN THE DEPARTING AFTERNOON SHORT
WAVE AND FORCING ALONG FRONT AND AHEAD OF MID-LEVEL TROUGH. WILL
START POPS IN THE CHANCE CATEGORY AND RAISE THEM TO CATEGORICAL IN
THE WEST BY 06Z THEN TAKE THE HIGHER POPS ACROSS THE REST OF THE CWA
OVERNIGHT WITH THE FRONT. AGAIN SOME ELEVATED INSTABILITY...CAPE
AROUND 200 J/KG...SO WILL KEEP SLIGHT CHANCE OF THUNDER. SHOWERS
BEGIN TO TAPER OFF FROM WEST TO EAST. WITH FROM NOT EXITING THE EAST
UNTIL AFTER 12Z...WILL SEE TEMPS HOLD IN THE 50S FOR LOWS...WITH
SOME UPPER 40S IN THE WEST BEHIND THE FRONT BY DAYBREAK.
MONDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE...HIGH
THE COLD FRONT WILL BE PUSHING THROUGH SOUTHERN WISCONSIN AT
DAYBREAK MONDAY MORNING...WITH A FEW SHOWERS POSSIBLE EAST AS THE
FRONT EXITS. IT SHOULD TURN DRY WITH DECREASING CLOUDS LATE
MORNING INTO THE AFTERNOON AS HIGH PRESSURE APPROACHES. WEST TO
NORTHWEST WINDS WILL BE BREEZY BEHIND THE DEPARTING FRONT.
THE HIGH WILL THEN SLIDE THROUGH TUESDAY AND WEDNESDAY...WITH
PLEASANT WEATHER EXPECTED.
TEMPS WILL REMAIN ABOVE NORMAL MOST PLACES MONDAY THROUGH
WEDNESDAY...THE WARMEST DAY FALLING ON TUESDAY. TEMPS WILL BE
COOLER NEAR THE LAKE TUE/WED UNDER ONSHORE WINDS.
WEDNESDAY NIGHT THROUGH SATURDAY...FORECAST CONFIDENCE...MEDIUM
THERE IS A CHANCE FOR SHOWERS AT TIMES WEDNESDAY NIGHT THROUGH
FRIDAY AS HIGH PRESSURE DEPARTS AND A COUPLE WAVES MOVE THROUGH.
MODELS ARE NOT IN GREAT AGREEMENT WITH THE TIMING/PLACEMENT OF
SYSTEMS DURING THIS PERIOD...SO KEPT POPS ON THE LOWER END FOR
NOW.
HIGH PRESSURE SHOULD RETURN FOR SATURDAY...BRINING MOSTLY SUNNY
SKIES TO START THE WEEKEND.
LOOKS LIKE MORE OF THE SAME WITH TEMPS FOR THE SECOND HALF OF THE
WEEK...ABOVE NORMAL WITH COOLER CONDITIONS NEAR LAKE MICHIGAN.
AVIATION/12Z TAFS/...LOOKING AT VFR CONDITIONS THROUGH THE DAY
WITH INCREASING MID CLOUDS ACROSS THE SOUTHERN FORECAST AREA AS
UPPER LEVEL WAVE MOVES THROUGH. COULD SEE A FEW LIGHT
SHOWERS/SPRINKLES WITH THIS WAVE THIS AFTERNOON. SOUTH WINDS WILL
INCREASE IN THE MID-LATE MORNING AND GUST TO 25 TO 28 KTS IN THE
WEST...AND 20 TO 25 KTS IN THE EAST.
RAIN SHOWERS WITH MVFR CIGS/VSBYS WILL MOVE WEST TO EAST ACROSS
THE AREA TONIGHT WITH A SURFACE TROUGH/COLD FRONT. COULD GET A FEW
RUMBLES OF THUNDER BUT INSTABILITY IS MINIMAL. LOOK FOR WEST WINDS
BEHIND THE FRONT MONDAY MORNING...INCREASING TO HIGHER LEVELS THAN
TODAY WIT GUSTS TO 30 KNOTS.
MARINE...WILL KEEP CURRENT TIMING OF SMALL CRAFT ADVISORY WITH
HIGHER SRLY WIND GUSTS NOT MIXING DOWN TO THE WATER UNTIL LATE
MORNING. WINDS MAY SUBSIDE FOR A TIME WITH PASSAGE OF FRONT EARLY
MONDAY MORNING BUT WILL TURN WEST AND RISE TO STRONGER LEVELS THAN
TODAY. WINDS WILL SUBSIDE BY MONDAY EVENING...AND WITH OFFSHORE
FETCH WAVES WILL BE JUST BELOW CRITERIA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM CDT MONDAY FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
MONDAY THROUGH SATURDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
558 AM CDT SUN APR 12 2015
.UPDATE...
ISSUED AT 444 AM CDT SUN APR 12 2015
SCATTERED SHOWERS AND EVEN A FEW LIGHTNING STRIKES HAVE DEVELOPED
ACROSS CENTRAL IA EARLY THIS MORNING AND ARE MOVING TO THE
NORTHEAST AROUND 25 KTS. LATEST HRRR HAS PICKED UP ON THESE TRENDS
AND WILL FOLLOW ITS SOLUTION FOR THE MORNING HOURS...RESULTING IN
SCATTERED SHOWERS MOVING INTO SOUTHEAST MN AND FAR WESTERN WI. SPC
MESOANALYSIS SHOWS NO INSTABILITY ACROSS THE AREA...BUT WITH A
FEW REPORTED LIGHTNING STRIKES...WILL ADD ISOLATED THUNDER AS
WELL. ANY ACCUMULATION WILL BE MINIMAL.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT SUN APR 12 2015
CHALLENGES INCLUDE WIND AND TEMPERATURES TODAY...FOLLOWED BY
SHOWER AND THUNDERSTORM CHANCES/TIMING THIS EVENING AND OVERNIGHT.
12.00Z GLOBAL MODEL SUITE IN GOOD AGREEMENT...BUT WILL FOLLOW
RAP/HRRR GUIDANCE FOR TIMING OF TONIGHT/S CONVECTION.
TODAY WILL BE WARM AND WINDY AHEAD OF A SURFACE TROUGH AND COLD
FRONT THAT MOVE THROUGH THE REGION LATER THIS EVENING AND OVERNIGHT.
CLEAR SKIES EARLY THIS MORNING WILL GIVE WAY TO INCREASING CLOUD
COVER THROUGH THE DAY ASSOCIATED WITH A LEADING SHORT-WAVE CURRENTLY
OVER NE/KS. SOME OF ITS SHOWER AND THUNDERSTORM ACTIVITY COULD
CLIP THE SOUTHERNMOST FORECAST AREA LATE THIS MORNING AND AFTERNOON
AS THE WAVE MOVES ACROSS NORTHERN MO/SOUTHERN IA...BUT THE REST OF
THE AREA WILL REMAIN DRY. 925 HPA TEMPERATURES RISE TO AROUND +12
CELSIUS THIS AFTERNOON...BUT CLOUD COVER SHOULD HELP LIMIT FULL
WARMING POTENTIAL WITH HIGHS IN THE MID TO UPPER 60S. HOWEVER...
TEMPERATURES INTO THE LOWER 70S ARE POSSIBLE MAINLY ACROSS SOUTHEAST
MN AND NORTHEAST IA IF MORE SUN THAN CLOUDS ARE REALIZED.
BIGGER CONCERN TODAY IS STRONG SOUTHERLY WINDS. AFTERNOON BOUNDARY
LAYER DEEPENS TO BETWEEN 800 AND 850 HPA WITH ROUGHLY 35 TO 40 KTS
TO MIX TO THE SURFACE. THIS WILL RESULT IN SUSTAINED WINDS FROM 20
TO 30 MPH WITH GUSTS UP TO 35 MPH. COULD SEE BRIEF WIND ADVISORY
CONDITIONS ACROSS WIND PRONE AREAS OF SOUTHEAST MN AND NORTHEAST
IA...BUT NOT ENOUGH CONFIDENCE AT THIS TIME TO ISSUE AN ADVISORY.
STRONG SOUTHERLY WIND WILL ADVECT MOISTURE NORTHWARD...RESULTING
IN DEW POINT TEMPERATURES RISING INTO THE 40S AND KEEPING MINIMUM
RH VALUES 40 PERCENT OR HIGHER.
COLD FRONT WILL APPROACH I-35 CORRIDOR BY 00Z TONIGHT AND THEN
SWEEP ACROSS THE UPPER MS RIVER VALLEY THIS EVENING INTO EARLY
MONDAY MORNING. STRONG WARMING IN THE 1-2 KM LAYER THIS EVENING
AHEAD OF THE FRONT WILL SQUASH ANY SURFACE BASED CONVECTION...BUT
MODEL SOUNDINGS DO SHOW 200 TO 500 J/KG OF ELEVATED SKINNY CAPE. 0
TO 6 KM BULK SHEAR INCREASES TO BETWEEN 30 AND 40 KTS LATER THIS
EVENING...BUT MOST OF THIS IS IN THE LOWEST COUPLE KILOMETERS. NOT
EXPECTING ANY SEVERE WEATHER AT THIS TIME...BUT COULD STILL SEE
SOME SMALL HAIL COMBINED WITH LIGHTNING AND BRIEF HEAVY DOWNPOURS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 352 AM CDT SUN APR 12 2015
SURFACE HIGH PRESSURE CENTER MOVES QUICKLY INTO NE/IA FOR MONDAY...
KEEPING THE FORECAST AREA WITHIN STRONGER PRESSURE GRADIENT ALONG
NORTHERN FLANK. AS A RESULT...EXPECT BREEZY NORTHWEST WIND WITH
SOME GUSTS UP TO 30 MPH. SKIES WILL BE MOSTLY SUNNY...BUT WITH
SLIGHTLY COOLER AIR MASS IN THE WAKE OF THE COLD FRONT...
AFTERNOON HIGHS WILL BE IN THE UPPER 50S TO LOWER 60S. IN
ADDITION...DRIER AIR MASS WILL ALLOW RELATIVE HUMIDITY TO DROP
INTO THE 25 TO 30 PERCENT RANGE.
DRY AND WARM CONDITIONS TO CONTINUE TUESDAY AND WEDNESDAY WITH
OCCASIONAL SOUTHERLY BREEZES AS 500 HPA RIDGE AXIS MOVES ACROSS
THE NATION/S MID-SECTION. DAILY HIGHS WILL RISE INTO THE MID TO
UPPER 60S WITH LOWS FROM THE MID 30S TO LOWER 40S.
LOW PRECIP CHANCES INCREASE WEDNESDAY NIGHT AND CONTINUE THROUGH
FRIDAY AS A COUPLE NORTHERN STREAM SHORT-WAVES MOVE ALONG THE
INTERNATIONAL BORDER. HOWEVER...WITH 500 HPA CLOSED LOW NOW
STALLING ACROSS THE SOUTHERN ROCKIES AND NOT PHASING WITH NORTHERN
SYSTEMS...NOT LOOKING AT ANY PROLONGED HEAVY RAIN. IN FACT...
INSTABILITY HAS ALL BUT DISAPPEARED...SO REMOVED ANY THUNDER
MENTION FOR THE LATTER HALF OF THE WEEK. EXPECT A RETURN TO DRY
CONDITIONS BY THE START OF NEXT WEEKEND. SEASONAL TEMPERATURES
WILL CONTINUE WITH DAILY HIGHS IN THE 60S AND LOWS IN THE UPPER
30S/LOWER 40S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 557 AM CDT SUN APR 12 2015
KEEPING AN EYE ON ACCAS/SCATTERED SHRA/ISOLD THUNDER MOVING ACROSS
NORTHEAST IA AND SOUTHEAST MN. THIS CONVECTION WAS AHEAD OF A
MID-LEVEL TROUGH AND PUSH OF MOISTURE. HAVE ADDED VCSH TO KRST
FROM TIL 14Z...BUT MAY HAVE TO EXTEND A BIT LONGER TIL THE WAVE
PUSHES EAST OF THE AREA AROUND 18Z. WILL ALSO HAVE TO WATCH KLSE
TAF FOR POSSIBLE INCLUSION OF VCSH AS WELL THIS MORNING.
OTHERWISE...MAIN CONCERN WILL BE GUSTY SOUTH WINDS AT BOTH TAF
SITES THROUGH THE DAY AHEAD OF AN APPROACHING COLD FRONT FROM THE
NORTHERN PLAINS. LOOKING AT SUSTAINED WINDS IN THE 15-25KT RANGE
WITH GUSTS 30-35KT. NEXT CONCERN WILL BE SHRA/TS ALONG AND AHEAD
OF THE COLD FRONT AS IT PUSHES INTO THE AREA THIS EVENING. VFR
CONDITIONS EXPECTED TODAY...BUT LIKELY DETERIORATING INTO MVFR
WITH SHRA/TS ACTIVITY. CONDITIONS EXPECTED TO IMPROVE EARLY MONDAY
MORNING AS THE FRONT PUSHES EAST OF THE AREA. VFR CONDITIONS
EXPECTED AFTER DAYBREAK MONDAY WITH WINDS BECOMING BREEZY FROM THE
WEST/NORTHWEST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...ROGERS
SHORT TERM...ROGERS
LONG TERM...ROGERS
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
444 AM CDT SUN APR 12 2015
.UPDATE...
ISSUED AT 444 AM CDT SUN APR 12 2015
SCATTERED SHOWERS AND EVEN A FEW LIGHTNING STRIKES HAVE DEVELOPED
ACROSS CENTRAL IA EARLY THIS MORNING AND ARE MOVING TO THE
NORTHEAST AROUND 25 KTS. LATEST HRRR HAS PICKED UP ON THESE TRENDS
AND WILL FOLLOW ITS SOLUTION FOR THE MORNING HOURS...RESULTING IN
SCATTERED SHOWERS MOVING INTO SOUTHEAST MN AND FAR WESTERN WI. SPC
MESOANALYSIS SHOWS NO INSTABILITY ACROSS THE AREA...BUT WITH A
FEW REPORTED LIGHTNING STRIKES...WILL ADD ISOLATED THUNDER AS
WELL. ANY ACCUMULATION WILL BE MINIMAL.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT SUN APR 12 2015
CHALLENGES INCLUDE WIND AND TEMPERATURES TODAY...FOLLOWED BY
SHOWER AND THUNDERSTORM CHANCES/TIMING THIS EVENING AND OVERNIGHT.
12.00Z GLOBAL MODEL SUITE IN GOOD AGREEMENT...BUT WILL FOLLOW
RAP/HRRR GUIDANCE FOR TIMING OF TONIGHT/S CONVECTION.
TODAY WILL BE WARM AND WINDY AHEAD OF A SURFACE TROUGH AND COLD
FRONT THAT MOVE THROUGH THE REGION LATER THIS EVENING AND OVERNIGHT.
CLEAR SKIES EARLY THIS MORNING WILL GIVE WAY TO INCREASING CLOUD
COVER THROUGH THE DAY ASSOCIATED WITH A LEADING SHORT-WAVE CURRENTLY
OVER NE/KS. SOME OF ITS SHOWER AND THUNDERSTORM ACTIVITY COULD
CLIP THE SOUTHERNMOST FORECAST AREA LATE THIS MORNING AND AFTERNOON
AS THE WAVE MOVES ACROSS NORTHERN MO/SOUTHERN IA...BUT THE REST OF
THE AREA WILL REMAIN DRY. 925 HPA TEMPERATURES RISE TO AROUND +12
CELSIUS THIS AFTERNOON...BUT CLOUD COVER SHOULD HELP LIMIT FULL
WARMING POTENTIAL WITH HIGHS IN THE MID TO UPPER 60S. HOWEVER...
TEMPERATURES INTO THE LOWER 70S ARE POSSIBLE MAINLY ACROSS SOUTHEAST
MN AND NORTHEAST IA IF MORE SUN THAN CLOUDS ARE REALIZED.
BIGGER CONCERN TODAY IS STRONG SOUTHERLY WINDS. AFTERNOON BOUNDARY
LAYER DEEPENS TO BETWEEN 800 AND 850 HPA WITH ROUGHLY 35 TO 40 KTS
TO MIX TO THE SURFACE. THIS WILL RESULT IN SUSTAINED WINDS FROM 20
TO 30 MPH WITH GUSTS UP TO 35 MPH. COULD SEE BRIEF WIND ADVISORY
CONDITIONS ACROSS WIND PRONE AREAS OF SOUTHEAST MN AND NORTHEAST
IA...BUT NOT ENOUGH CONFIDENCE AT THIS TIME TO ISSUE AN ADVISORY.
STRONG SOUTHERLY WIND WILL ADVECT MOISTURE NORTHWARD...RESULTING
IN DEW POINT TEMPERATURES RISING INTO THE 40S AND KEEPING MINIMUM
RH VALUES 40 PERCENT OR HIGHER.
COLD FRONT WILL APPROACH I-35 CORRIDOR BY 00Z TONIGHT AND THEN
SWEEP ACROSS THE UPPER MS RIVER VALLEY THIS EVENING INTO EARLY
MONDAY MORNING. STRONG WARMING IN THE 1-2 KM LAYER THIS EVENING
AHEAD OF THE FRONT WILL SQUASH ANY SURFACE BASED CONVECTION...BUT
MODEL SOUNDINGS DO SHOW 200 TO 500 J/KG OF ELEVATED SKINNY CAPE. 0
TO 6 KM BULK SHEAR INCREASES TO BETWEEN 30 AND 40 KTS LATER THIS
EVENING...BUT MOST OF THIS IS IN THE LOWEST COUPLE KILOMETERS. NOT
EXPECTING ANY SEVERE WEATHER AT THIS TIME...BUT COULD STILL SEE
SOME SMALL HAIL COMBINED WITH LIGHTNING AND BRIEF HEAVY DOWNPOURS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 352 AM CDT SUN APR 12 2015
SURFACE HIGH PRESSURE CENTER MOVES QUICKLY INTO NE/IA FOR MONDAY...
KEEPING THE FORECAST AREA WITHIN STRONGER PRESSURE GRADIENT ALONG
NORTHERN FLANK. AS A RESULT...EXPECT BREEZY NORTHWEST WIND WITH
SOME GUSTS UP TO 30 MPH. SKIES WILL BE MOSTLY SUNNY...BUT WITH
SLIGHTLY COOLER AIR MASS IN THE WAKE OF THE COLD FRONT...
AFTERNOON HIGHS WILL BE IN THE UPPER 50S TO LOWER 60S. IN
ADDITION...DRIER AIR MASS WILL ALLOW RELATIVE HUMIDITY TO DROP
INTO THE 25 TO 30 PERCENT RANGE.
DRY AND WARM CONDITIONS TO CONTINUE TUESDAY AND WEDNESDAY WITH
OCCASIONAL SOUTHERLY BREEZES AS 500 HPA RIDGE AXIS MOVES ACROSS
THE NATION/S MID-SECTION. DAILY HIGHS WILL RISE INTO THE MID TO
UPPER 60S WITH LOWS FROM THE MID 30S TO LOWER 40S.
LOW PRECIP CHANCES INCREASE WEDNESDAY NIGHT AND CONTINUE THROUGH
FRIDAY AS A COUPLE NORTHERN STREAM SHORT-WAVES MOVE ALONG THE
INTERNATIONAL BORDER. HOWEVER...WITH 500 HPA CLOSED LOW NOW
STALLING ACROSS THE SOUTHERN ROCKIES AND NOT PHASING WITH NORTHERN
SYSTEMS...NOT LOOKING AT ANY PROLONGED HEAVY RAIN. IN FACT...
INSTABILITY HAS ALL BUT DISAPPEARED...SO REMOVED ANY THUNDER
MENTION FOR THE LATTER HALF OF THE WEEK. EXPECT A RETURN TO DRY
CONDITIONS BY THE START OF NEXT WEEKEND. SEASONAL TEMPERATURES
WILL CONTINUE WITH DAILY HIGHS IN THE 60S AND LOWS IN THE UPPER
30S/LOWER 40S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 950 PM CDT SAT APR 11 2015
CIGS...
SKC/SCT HIGH CLOUDS EXPECTED TONIGHT INTO SUN...WITH AN
INCREASING MID DECK SAT AFTERNOON ASSOCIATED WITH AN UPPER LEVEL
SHORTWAVE TROUGH. EXPECT THESE TO BE VFR AT THIS TIME.
CIGS SHOULD LOWER INTO THE IFR/MVFR CATEGORIES AHEAD OF A COLD FRONT
AND STRONGER UPPER LEVEL DISTURBANCE SUN NIGHT - PER RH FIELDS AND
BUFKIT SOUNDINGS.
WINDS...
PRESSURE GRADIENT CONTINUES TO TIGHTEN TONIGHT AS HIGH
PRESSURE EXITS TO THE SOUTHEAST AND A COLD FRONT APPROACHES FROM THE
NORTHERN PLAINS. DIRECTION WILL BE SOUTHERLY UNTIL THE FRONT MOVES
THROUGH NEAR 06Z MON. EXPECT SUSTAINED 20KTS WITH HIGHER GUSTS AT
KRST SUNDAY.
LLWS LOOKS LIKE AN ISSUE FOR BOTH TAF SITES...WITH BUFKIT
HRRR/RAP/NAM12 SOUNDINGS ALL SUGGESTING 45-50 KTS JUST SUB 2 KFT
OVERNIGHT-EARLY SUN MORNING. TIMING APPROX 08-15Z.
WX/VSBY...
A FEW -SHRA/TS ARE POSSIBLE LATE SUN AFTERNOON AS THE FIRST
SHORTWAVE SPINS NORTHEAST ACROSS IA AND INTO SOUTHERN WI. HOWEVER...
FORECAST TRACKS WOULD KEEP THE PCPN POTENTIAL SOUTH OF THE TAF
SITES...AND WILL KEEP TAFS DRY FOR THAT PERIOD AS A RESULT.
THAT SAID...AREAS OF SHRA/TS SHOULD MOVE ACROSS KRST/KLSE SUNDAY
EVENING-NIGHT...AHEAD OF AND ALONG THE COLD FRONT. MORE -SHRA...BUT
ENOUGH ELEVATED INSTABILITY FOR SOME THUNDER CHANCES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...ROGERS
SHORT TERM...ROGERS
LONG TERM...ROGERS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
552 AM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING...FOLLOWED BY
HIGH PRESSURE BUILDING INTO THE REGION THROUGH THURSDAY...MOVING
OFFSHORE THURSDAY NIGHT. A FRONTAL SYSTEM COULD BRING SOME RAIN
FOR PARTS OF THE WEEKEND AND INTO THE FIRST PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST IS GENERALLY ON TRACK. MADE SOME MINOR ADJUSTMENTS TO
HOURLY T/TD/SKY AND POPS OVER THE NEXT 6 HOURS TO FIT BETTER WITH
CURRENT OBS AND RADAR TRENDS.
SHORTWAVE TROUGH PASSES TO THE N TODAY WITH A COLD FRONT TRACKING
ACROSS THE AREA THIS MORNING. WINDS HAVE JUST SHIFTED TO THE NW AT
KMGJ AS OF 930Z AND WILL CONTINUE TO TRACK SE REACHING NYC AROUND
12Z AND THEN ACROSS THE REST OF THE AREA THROUGH MID MORNING.
BAND OF SHOWERS ALONG AND BEHIND THE FRONT DOES NOT APPEAR TO BE
WEAKENING AS THE HRRR AND HI RES NAM HAS BEEN INDICATING...SO POPS
LOOK GOOD. THIS BAND WILL TRAVERSE THE REGION THROUGH AROUND 15Z.
DRY CONDS THEN RETURN ALTHOUGH HIGH CLOUDS WILL REMAIN OHD INTO
TONIGHT. HAVE KEPT A PTLY SUNNY FORECAST AS A RESULT ALTHOUGH THERE
IS SOME UNCERTAINTY IN THE OPACITY...AND COULD HAVE TO LOWER
CLOUDS COVER LATER TODAY...ESPECIALLY NRN ZONES. CLOSER TO THE
COAST...MOSTLY CLOUDY CONDS ARE EXPECTED WITH SHOWERS LINGERING
MAINLY OFFSHORE THROUGH THE DAY.
CAA IS VERY GRADUAL BEHIND THE FROPA...SO HIGHS ARE EXPECTED TO BE
IN THE LOWER TO MID 60S ACROSS THE LOCAL AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
A WAVE OF LOW PRES WILL DEVELOP ALONG THE FRONT LATE THIS AFTN/EVE
PASSING TO THE S TONIGHT. NO IMPACTS ARE EXPECTED FROM THIS. SKIES
WILL CLEAR TONIGHT WITH PERHAPS JUST SOME THIN CIRRUS FROM THE LOW
PASSING TO THE S. LIGHT NLY WINDS AND A MOSTLY CLEAR SKY WILL
ALLOW FOR GOOD RADIATIONAL COOLING CONDS WITH THE USUALLY COLDER
SPOTS DROPPING INTO THE 30S. THE GROWING SEASON EXPANDS TO INCLUDE
ALL OF LONG ISLAND...COASTAL CT...SRN PORTIONS OF THE LOWER HUDSON
VALLEY AND MOST OF NE NJ ON THE 15TH...ALTHOUGH DEWPOINT
DEPRESSIONS LOOK TO BE BETWEEN 15 AND 20 DEGREES. THEREFORE...NOT
EXPECTING ANY FROST DEVELOPMENT IN EASTERN LI AND SE COASTAL CT.
CANADIAN HIGH PRES BUILDS IN FOR WED WITH SUNNY SKIES AND HIGHS IN
THE MID TO UPPER 60S UNDER A NLY FLOW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL PROVIDE FAIR AND DRY CONDITIONS WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT. THE HIGH WILL BUILD OFFSHORE THURSDAY NIGHT
AND FRIDAY.
A FRONTAL BOUNDARY WILL THEN SET UP NEAR THE REGION ON FRIDAY AND
REMAIN NEAR THE REGION THROUGH THE WEEKEND. SEVERAL WAVES OF LOW
PRESSURE TRAVELING ALONG THE FRONT WILL BRING PERIODS OF UNSETTLED
WEATHER TO THE REGION THROUGH THIS TIME PERIOD. ANY PRECIPITATION
THIS WEEKEND WILL BE ON AND OFF AND WILL LIMIT POPS TO CHANCE OR
SLIGHT CHANCE. THE UNSETTLED WEATHER COULD CONTINUE INTO MONDAY.
FOR TEMPERATURES...EXPECT HIGHS TO WARM A LITTLE BIT EACH DAY
THROUGH SATURDAY WITH HIGHS IN THE 50S AND LOWER 60S ON THURSDAY...
LOWER AND MIDDLE 60S ON FRIDAY AND MIDDLE 60S TO LOWER 70S ON
SATURDAY. HIGHS FALL BACK INTO THE UPPER 50S TO MIDDLE 60S SUNDAY
AND MONDAY.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
A COLD FRONT WILL REACH KSWF JUST BEFORE DAYBREAK...THE NYC METRO
AREA BY 12Z...AND THE LONG ISLAND/CT TERMINALS FROM 13Z-15Z.
POST-FRONTAL RAIN BAND OVER ERN PA IS HOLDING TOGETHER ATTM BUT IS
FCST TO WEAKEN...AT WORST IT SHOULD BRING BRIEF MVFR CIGS TO MOST
TERMINALS AFTER PASSAGE.
LOW STRATUS HAS DEVELOPED ALONG THE COAST A LITTLE SOONER THAN
EXPECTED...IMPACTING KISP WITH IFR CIGS AS OF 08Z AND ABOUT TO DO
THE SAME AT KGON BY 09Z-10Z. STILL A CHANCE OF IMPACT AT KJFK FROM
10Z-12Z THOUGH HAVE GONE TEMPO RATHER THAN PREVAILING.
WINDS WITH FROPA IN ERN PA ARE SHIFTING MORE SHARPLY NW AND
BRIEFLY GUSTING TO 20 KT...SO HAVE INDICATED THIS IN TAF.
MEDIUM TO HIGH CONFIDENCE WIND FCST THROUGH THIS MORNING...THEN
LOW CONFIDENCE THIS AFTERNOON. BANKING ON POST-FRONTAL WINDS
BECOMING WEAK ENOUGH TO ALLOW WEAK SEA BREEZES TO DEVELOP THIS
AFTERNOON...WITH EXACT TIMING OF ONSET UNCERTAIN. IF SEA BREEZES
DO NOT DEVELOP...WOULD INSTEAD EXPECT E-NE FLOW 5-8 KT FROM MID TO
LATE AFTERNOON.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT:
HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: LOW CONFIDENCE IN WIND DIRECTION
THIS AFTERNOON.
KLGA FCSTER COMMENTS: LOW CONFIDENCE IN WIND DIRECTION
THIS AFTERNOON.
KEWR FCSTER COMMENTS: LOW CONFIDENCE IN WIND DIRECTION
THIS AFTERNOON.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: LOW CONFIDENCE IN WIND DIRECTION
THIS AFTERNOON.
KHPN FCSTER COMMENTS: LOW CONFIDENCE IN WIND DIRECTION
THIS AFTERNOON.
KISP FCSTER COMMENTS: LOW CONFIDENCE IN WIND DIRECTION
THIS AFTERNOON.
.OUTLOOK FOR 06Z WED THROUGH SAT...
.LATE TUE NIGHT-THU...VFR.
.THU NIGHT...MVFR CONDS POSSIBLE LATE AT NIGHT.
.FRI-SAT...MVFR CONDS POSSIBLE IN SHOWERS.
&&
.MARINE...
S-SW WINDS OF 15-20 KT AHEAD OF THE COLD FRONT EARLY THIS MORNING
IS EXPECTED TO BUILD SEAS TO MARGINAL SCA LEVELS ON THE OCEAN
WATERS. SEAS HAVE BEEN SLOW TO BUILD...AND MAY FALL JUST SHORT OF
5 FT...BUT DON`T HAVE HIGH ENOUGH CONFIDENCE THAT IT WON`T HAPPEN
TO TAKE IT DOWN. GUSTS SHOULD ONLY TOP OUT AROUND 20 KT DUE TO A
STRONG INVERSION OVER THE WATERS. LOW PRES PASSES S OF THE WATERS
TONIGHT WITH CANADIAN HIGH PRES BUILDING IN FOR WED. SUB-ADVSY
CONDS WILL PREVAIL THROUGH THIS TIME.
SUB SCA CONDITIONS ARE LIKELY WEDNESDAY NIGHT THROUGH FRIDAY NIGHT.
SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY TO RETURN TO THE OCEAN
WATERS THIS WEEKEND.&&
.HYDROLOGY...
LESS THAN 1/4 OF AN INCH OF BASIN AVERAGE RAINFALL IS EXPECTED
THIS MORNING. MAINLY DRY WEATHER IS EXPECTED FROM THIS AFTERNOON-
THU NIGHT. THE NEXT CHANCE FOR MEASURABLE RAIN WILL BE FRIDAY AND
INTO THE WEEKEND.
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 WEB SITE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ350-
353.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW YORK NY
436 AM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING...FOLLOWED BY
HIGH PRESSURE BUILDING INTO THE REGION THROUGH THURSDAY...MOVING
OFFSHORE THURSDAY NIGHT. A FRONTAL SYSTEM COULD BRING SOME RAIN
FOR PARTS OF THE WEEKEND AND INTO THE FIRST PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHORTWAVE TROUGH PASSES TO THE N TODAY WITH A COLD FRONT TRACKING
ACROSS THE AREA THIS MORNING. AT 07Z...COLD FRONT HAD JUST PASSED
THROUGH KMSV AND KABE WITH A BAND OF POST- FRONTAL SHOWERS JUST
BEHIND IT. THIS WILL TRAVERSE THE REGION FROM 09Z THROUGH AROUND
15Z...ALTHOUGH THE HI RES NAM AND HRRR TRENDS ARE INDICATING THE
SHOWERS BREAK UP AS THEY APPROACH NYC AND SOUTHERN CT AND THEN
REINVIGORATE S OF LONG ISLAND LATE THIS MORNING. AM HESITANT TO
LOWER POPS WITH A 50-60KT LLJ IN PLACE TO AID IN LIFT..ALTHOUGH
HAVE LOWERED QPF AMOUNTS TO 1-2 TENTHS.
HIGH CLOUDS WILL REMAIN OHD INTO TONIGHT...AND HAVE KEPT A PTLY
SUNNY FORECAST AS A RESULT. THERE IS SOME UNCERTAINTY IN THE
OPACITY OF IT...AND COULD HAVE TO LOWER CLOUDS COVER LATER
TODAY...ESPECIALLY NRN ZONES. CLOSER TO THE COAST...MOSTLY CLOUDY
CONDS ARE EXPECTED WITH SHOWERS LINGERING MAINLY OFFSHORE THROUGH
THE DAY.
CAA IS VERY GRADUAL BEHIND THE FROPA...SO HIGHS ARE EXPECTED TO BE
IN THE LOWER TO MID 60S ACROSS THE LOCAL AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
A WAVE OF LOW PRES WILL DEVELOP ALONG THE FRONT LATE THIS AFTN/EVE
PASSING TO THE S TONIGHT. NO IMPACTS ARE EXPECTED FROM THIS. SKIES
WILL CLEAR TONIGHT WITH PERHAPS JUST SOME THIN CIRRUS FROM THE LOW
PASSING TO THE S. LIGHT NLY WINDS AND A MOSTLY CLEAR SKY WILL
ALLOW FOR GOOD RADIATIONAL COOLING CONDS WITH THE USUALLY COLDER
SPOTS DROPPING INTO THE 30S. THE GROWING SEASON EXPANDS TO INCLUDE
ALL OF LONG ISLAND...COASTAL CT...SRN PORTIONS OF THE LOWER HUDSON
VALLEY AND MOST OF NE NJ ON THE 15TH...ALTHOUGH DEWPOINT
DEPRESSIONS LOOK TO BE BETWEEN 15 AND 20 DEGREES. THEREFORE...NOT
EXPECTING ANY FROST DEVELOPMENT IN EASTERN LI AND SE COASTAL CT.
CANADIAN HIGH PRES BUILDS IN FOR WED WITH SUNNY SKIES AND HIGHS IN
THE MID TO UPPER 60S UNDER A NLY FLOW.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL PROVIDE FAIR AND DRY CONDITIONS WEDNESDAY NIGHT
THROUGH THURSDAY NIGHT. THE HIGH WILL BUILD OFFSHORE THURSDAY NIGHT
AND FRIDAY.
A FRONTAL BOUNDARY WILL THEN SET UP NEAR THE REGION ON FRIDAY AND
REMAIN NEAR THE REGION THROUGH THE WEEKEND. SEVERAL WAVES OF LOW
PRESSURE TRAVELING ALONG THE FRONT WILL BRING PERIODS OF UNSETTLED
WEATHER TO THE REGION THROUGH THIS TIME PERIOD. ANY PRECIPITATION
THIS WEEKEND WILL BE ON AND OFF AND WILL LIMIT POPS TO CHANCE OR
SLIGHT CHANCE. THE UNSETTLED WEATHER COULD CONTINUE INTO MONDAY.
FOR TEMPERATURES...EXPECT HIGHS TO WARM A LITTLE BIT EACH DAY
THROUGH SATURDAY WITH HIGHS IN THE 50S AND LOWER 60S ON THURSDAY...
LOWER AND MIDDLE 60S ON FRIDAY AND MIDDLE 60S TO LOWER 70S ON
SATURDAY. HIGHS FALL BACK INTO THE UPPER 50S TO MIDDLE 60S SUNDAY
AND MONDAY.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
A COLD FRONT WILL REACH KSWF JUST BEFORE DAYBREAK...THE NYC METRO
AREA BY 12Z...AND THE LONG ISLAND/CT TERMINALS FROM 13Z-15Z.
POST-FRONTAL RAIN BAND OVER ERN PA IS HOLDING TOGETHER ATTM BUT IS
FCST TO WEAKEN...AT WORST IT SHOULD BRING BRIEF MVFR CIGS TO MOST
TERMINALS AFTER PASSAGE.
LOW STRATUS HAS DEVELOPED ALONG THE COAST A LITTLE SOONER THAN
EXPECTED...IMPACTING KISP WITH IFR CIGS AS OF 08Z AND ABOUT TO DO
THE SAME AT KGON BY 09Z-10Z. STILL A CHANCE OF IMPACT AT KJFK FROM
10Z-12Z THOUGH HAVE GONE TEMPO RATHER THAN PREVAILING.
WINDS WITH FROPA IN ERN PA ARE SHIFTING MORE SHARPLY NW AND
BRIEFLY GUSTING TO 20 KT...SO HAVE INDICATED THIS IN TAF.
MEDIUM TO HIGH CONFIDENCE WIND FCST THROUGH THIS MORNING...THEN
LOW CONFIDENCE THIS AFTERNOON. BANKING ON POST-FRONTAL WINDS
BECOMING WEAK ENOUGH TO ALLOW WEAK SEA BREEZES TO DEVELOP THIS
AFTERNOON...WITH EXACT TIMING OF ONSET UNCERTAIN. IF SEA BREEZES
DO NOT DEVELOP...WOULD INSTEAD EXPECT E-NE FLOW 5-8 KT FROM MID TO
LATE AFTERNOON.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT:
HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: LOW CONFIDENCE IN WIND DIRECTION
THIS AFTERNOON.
KLGA FCSTER COMMENTS: LOW CONFIDENCE IN WIND DIRECTION
THIS AFTERNOON.
KEWR FCSTER COMMENTS: LOW CONFIDENCE IN WIND DIRECTION
THIS AFTERNOON.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: LOW CONFIDENCE IN WIND DIRECTION
THIS AFTERNOON.
KHPN FCSTER COMMENTS: LOW CONFIDENCE IN WIND DIRECTION
THIS AFTERNOON.
KISP FCSTER COMMENTS: LOW CONFIDENCE IN WIND DIRECTION
THIS AFTERNOON.
.OUTLOOK FOR 06Z WED THROUGH SAT...
.LATE TUE NIGHT-THU...VFR.
.THU NIGHT...MVFR CONDS POSSIBLE LATE AT NIGHT.
.FRI-SAT...MVFR CONDS POSSIBLE IN SHOWERS.
&&
.MARINE...
S-SW WINDS OF 15-20 KT AHEAD OF THE COLD FRONT EARLY THIS MORNING
IS EXPECTED TO BUILD SEAS TO MARGINAL SCA LEVELS ON THE OCEAN
WATERS. SEAS HAVE BEEN SLOW TO BUILD...AND MAY FALL JUST SHORT OF
5 FT...BUT DON`T HAVE HIGH ENOUGH CONFIDENCE THAT IT WON`T HAPPEN
TO TAKE IT DOWN. GUSTS SHOULD ONLY TOP OUT AROUND 20 KT DUE TO A
STRONG INVERSION OVER THE WATERS. LOW PRES PASSES S OF THE WATERS
TONIGHT WITH CANADIAN HIGH PRES BUILDING IN FOR WED. SUB-ADVSY
CONDS WILL PREVAIL THROUGH THIS TIME.
SUB SCA CONDITIONS ARE LIKELY WEDNESDAY NIGHT THROUGH FRIDAY NIGHT.
SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY TO RETURN TO THE OCEAN
WATERS THIS WEEKEND.&&
.HYDROLOGY...
LESS THAN 1/4 OF AN INCH OF BASIN AVERAGE RAINFALL IS EXPECTED
THIS MORNING. MAINLY DRY WEATHER IS EXPECTED FROM THIS AFTERNOON-
THU NIGHT. THE NEXT CHANCE FOR MEASURABLE RAIN WILL BE FRIDAY AND
INTO THE WEEKEND.
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 WEB SITE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT THIS MORNING FOR ANZ350-
353.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBANY NY
354 AM EDT TUE APR 14 2015
.SYNOPSIS...
A FAST MOVING COLD FRONT WILL BRING SHOWERS TO THE AREA THROUGH
EARLY THIS MORNING. DRY WEATHER WILL RETURN THIS AFTERNOON AND
PERSIST THROUGH THURSDAY. OUR NEXT CHANCES FOR SHOWERS WILL COME
LATE IN THE WEEK INTO THE FIRST PART OF THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS AFTERNOON/...
AS OF 350 AM EDT...REGIONAL MOSAIC RADAR IMAGERY CONTINUES TO
SHOW A BAND OF SHOWERS MOVING THROUGH THE REGION FROM SOUTHWEST TO
NORTHEAST. THESE SHOWERS ARE ALONG/AHEAD OF A FAST MOVING SFC COLD
FRONT AND UPPER LEVEL SHORTWAVE MOVING ACROSS EASTERN NY. THERE
MAY BE SOME ELEVATED CONVECTIVE ELEMENTS WITHIN THE SHOWERS. THE
LATEST 3KM HRRR SHOWS THESE ELEMENTS WEAKENING AS THEY MOVE
THROUGH OUR REGION...AS NOCTURNAL EFFECTS CONTINUE TO OCCUR AND
THE HEAVIER SHOWERS STARTS TO OUTRUN THEIR BEST SUPPORT ALOFT.
SHOWERS HAVE BEEN TRACKED SW TO NE...SO IT WILL TAKE A LITTLE
WHILE STILL FOR ACTIVITY TO REACH OUR ENTIRE AREA. WHILE SHOWERS
HAVE ALREADY ENDED ACROSS MOST OF THE WESTERN ADIRONDACKS AND
WESTERN MOHAWK VALLEY...IT WILL TAKE SOME TIME FOR THE SHOWERS TO
COMPLETELY CLEAR OUR FA WHICH WILL NOT OCCUR UNTIL LATER THIS
MORNING. TOTAL QPF FROM THE SHOWERS WILL GENERALLY BE A TENTH TO A
QUARTER OF AN INCH...WITH ISOLATED AMOUNTS UP TO A THIRD OF AN
INCH.
FOR THIS AFTERNOON EXPECT DRY CONDITIONS WITH MOSTLY SUNNY SKIES
NORTH AND MOSTLY CLOUDY SKIES SOUTH AS THERE WILL STILL BE A
CANOPY OF CIRRUS CLOUDS IN PLACE. IT WILL STILL BE BREEZY WITH
WEST WINDS 10 TO 20 MPH WITH GUSTS UP TO 35 MPH. HIGHS TODAY WILL
GENERALLY BE IN THE 60S WITH SOME UPPER 50S ACROSS PARTS OF THE
WESTERN ADIRONDACKS...TACONICS AND BERKSHIRES.
&&
.SHORT TERM /6 PM THIS AFTERNOON THROUGH THURSDAY NIGHT/...
CLEAR AND DRY WEATHER IS EXPECTED TONIGHT THROUGH MUCH OF
THURSDAY AS A LARGE RIDGE OF HIGH PRESSURE BUILDS EAST FROM THE
GREAT LAKES REGION TONIGHT ACROSS OUR REGION ON WEDNESDAY AND OFF
THE NEW ENGLAND COAST LATE WEDNESDAY NIGHT. EXPECT LOWS TONIGHT TO
BE IN THE UPPER 20S TO MID 30S WITH HIGHS ON WEDNESDAY IN THE
UPPER 50S TO UPPER 60S. LOWS WEDNESDAY NIGHT ARE EXPECTED TO RANGE
FROM THE UPPER TEENS NORTHWEST TO LOWER 30S SOUTHEAST WITH HIGHS
ON THURSDAY IN THE LOW TO MID 60S.
CLOUDS WILL BE INCREASING ACROSS THE REGION FROM WEST TO EAST LATE
THURSDAY WITH A CHANCE OF SHOWERS THURSDAY NIGHT ACROSS THE
NORTHWEST 3/4S OF THE FA AS A LOW PRESSURE SYSTEM STARTS TO LIFT
NORTHEAST FROM THE SOUTHEAST STATES AS A STATIONARY FRONT IS
DRAPED TO THE NORTH ACROSS SOUTHERN CANADA. LOWS THURSDAY NIGHT
WILL BE IN THE MID 30S TO MID 40S. THERE IS EVEN THE POSSIBILITY
OF A LITTLE SNOW ACROSS THE WESTERN ADIRONDACKS AND SOUTHERN GREEN
MOUNTAINS WITH LITTLE OR NO ACCUMULATION.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
UNSETTLED WEATHER IS EXPECTED AT TIMES DURING THE EXTENDED
PERIOD...AS SEVERAL FAST MOVING STORM SYSTEMS EMBEDDED WITHIN THE
ZONAL FLOW IMPACT THE REGION.
FRIDAY...AN UPPER LEVEL DISTURBANCE WILL PASS ACROSS THE REGION.
THIS SYSTEM WILL BE FAIRLY WEAK AND THERE WON/T BE A TON OF MOISTURE
TO WORK WITH...BUT THERE IS A CHANCE FOR SOME LIGHT RAIN SHOWERS
ACROSS THE AREA...ALONG WITH PLENTY OF CLOUDS. TEMPS LOOK
SEASONABLE...WITH HIGHS IN THE MID 50S TO LOW 60S.
FRIDAY NIGHT...THERE MAY BE A LULL IN THE ACTION FOR FRIDAY NIGHT
INTO AT LEAST SATURDAY MORNING. HOWEVER...STILL CANNOT TOTALLY RULE
OUT A SHOWER SO WILL MAINTAIN SLIGHT CHC TO LOW CHC POPS FOR FRIDAY
NIGHT. WITH PLENTY OF LINGERING CLOUDS AROUND...LOW TEMPERATURES
SHOULD ONLY FALL INTO THE 40S FOR MOST AREAS.
SATURDAY-SATURDAY NIGHT...A MUCH STRONGER FRONTAL SYSTEM WILL BE
APPROACHING FOR SAT AFTN INTO SAT NIGHT. THERE WILL BE BETTER CHANCE
FOR RAIN SHOWERS WITH THIS SYSTEM...AS THERE WILL BE A STRONGER
THERMAL GRADIENT WITH THE SFC COLD FRONT AS COMPARED TO THE PREVIOUS
STORM SYSTEM. THERE ARE STILL TIMING DIFFERENCES WITHIN THE
MODELS...SO WON/T GO ANY HIGHER THAN CHC FOR POPS SAT AFTN THROUGH
SAT NIGHT UNTIL THE TIMING BECOMES MORE CERTAIN. TEMPS ON SAT LOOK
TO BE IN THE UPPER 50S TO UPPER 60S AHEAD OF THE APPROACHING FRONTAL
BOUNDARY...WARMEST ACROSS PORTIONS OF THE MID HUDSON VALLEY AND
SOUTHERN LITCHFIELD CO CT. SHOWERS SHOULD BE ENDING SOMETIME SAT
EVENING OR NIGHT. SAT NT/SUN AM LOWS SHOULD FALL INTO THE 30S TO
LOWER 40S.
SUNDAY-SUNDAY NIGHT...A BIT MORE UNCERTAINTY...AS THE 00Z/14 GFS AND
GEFS SUGGEST A SOUTHERN STREAM DISTURBANCE BRINGS CLOUDS AND SOME
SHOWERS TO THE REGION BY SUNDAY AFTERNOON...WHILE THE 00Z/14 ECMWF
AND GEM KEEP A TRANSIENT UPPER LEVEL RIDGE IN PLACE LONGER WITH DRY
WEATHER. SINCE PREVIOUS CYCLES OF THE GFS WERE NOT NEARLY AS
PESSIMISTIC...WILL KEEP THINGS GENERALLY DRY WITH THE EXCEPTION OF
SOME SLIGHT CHC/LOW CHC POPS FOR EXTREME SOUTHERN AREAS...MAINLY FOR
LATE IN THE DAY OR AT NIGHT. TEMPS WILL GENERALLY BE IN THE 50S TO
LOW 60S FOR HIGHS ON SUNDAY...WITH LOWS MAINLY IN THE 30S TO LOWER
40S FOR SUN NIGHT.
MON-TUE...THE NEXT STORM SYSTEM LOOKS TO IMPACT THE REGION AT SOME
POINT EARLY NEXT WEEK WITH ANOTHER SHOT OF RAIN SHOWERS. CURRENT
TIMING FAVORS BEST CHANCE FOR MON INTO EARLY MON NT...THEN POSSIBLY
TAPERING OFF BY TUE. WILL INDICATE CHC POPS FOR MON-MON NT...BEFORE
ONLY SLIGHT CHC FOR TUE. GIVEN THE CURRENT EXPECTATION FOR CLOUDS AND
SHOWERS FOR MON...WILL INDICATE SLIGHTLY BELOW NORMAL TEMPS...WITH
HIGHS MAINLY IN THE 50S AND LOWS MON NT/TUE AM IN THE 30S TO LOWER
40S. STILL COOL ON TUE...WITH HIGHS AGAIN MAINLY 55-60 IN VALLEYS
AND LOWER 50S ACROSS HIGHER ELEVATIONS.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
A COLD FRONT WILL MOVE EASTWARD ACROSS THE TAF SITES OVERNIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE WEST FOR TUESDAY.
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH AT LEAST 06Z/WED. A
BAND OF SHOWERS...MAINLY LIGHT IN INTENSITY...WILL MOVE EASTWARD
IN ASSOCIATION WITH THE COLD FRONTAL PASSAGE PRIOR TO DAYBREAK.
THE SHOWERS SHOULD BECOME MORE SPOTTY ONCE THEY REACH THE TAF
SITES. THE BEST CHANCE FOR SHOWERS SHOULD BE BETWEEN 06Z-
10Z/TUE...EXCEPT A BIT LATER...08Z-12Z/TUE AT KPSF AND KPOU. THERE
IS A SLIGHT CHANCE OF BRIEF MVFR CONDITIONS AS THE SHOWERS PASS
THROUGH...WITH THE GREATEST CHANCE AT KPSF.
OTHERWISE...ONLY HIGH CLOUDS ARE EXPECTED AT TIMES TUESDAY AND
TUESDAY NIGHT.
STRONG SOUTH WINDS WILL PERSIST AHEAD OF THE COLD FRONT...AT 10-15
KT...WITH SOME GUSTS OF 20-30 KT...STRONGEST AT KALB. WINDS WILL
SHIFT INTO THE WEST AS THE FRONT PASSES...AND MAY BRIEFLY GUST UP
TO 30 KT WITH THE INITIAL WIND SHIFT. OTHERWISE...WEST TO
NORTHWEST WINDS WILL AVERAGE 5-10 KT AROUND DAYBREAK
TUESDAY...THEN INCREASE TO 10-15 KT...WITH SOME GUSTS OF 20-25 KT
POSSIBLE AT KGFL/KALB AND KPSF. AT KPOU...WINDS SHOULD REMAIN
LIGHTER DURING TUE...AND BECOME NORTHWEST TO NORTH IN THE
AFTERNOON AT GENERALLY 5-10 KT. WINDS AT ALL TAF SITES SHOULD
REMAIN FROM THE WEST...AND DECREASE TO 5-10 KT SHORTLY AFTER
SUNSET TUESDAY.
OUTLOOK...
TUE NIGHT-THU: NO OPERATIONAL IMPACT. NO SIG WX.
THU NIGHT-FRI: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRI NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SAT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
...WEST WINDS MAY GUST AS HIGH AS 35 MPH THIS AFTERNOON
ESPECIALLY ACROSS THE HIGHER TERRAIN...
A FAST MOVING COLD FRONT WILL BRING SHOWERS TO THE AREA THROUGH
EARLY THIS MORNING. DRY WEATHER WILL RETURN THIS AFTERNOON AND
PERSIST THROUGH THURSDAY. OUR NEXT CHANCES FOR SHOWERS WILL COME
LATE IN THE WEEK INTO THE FIRST PART OF THE WEEKEND.
&&
.HYDROLOGY...
A FAST MOVING COLD FRONT WILL BRING SHOWERS TO THE AREA THROUGH
EARLY THIS MORNING. DRY WEATHER WILL RETURN THIS AFTERNOON AND
PERSIST THROUGH THURSDAY. OUR NEXT CHANCES FOR SHOWERS WILL COME
LATE IN THE WEEK INTO THE FIRST PART OF THE WEEKEND.
THERE WILL BE RISES ON SOME RIVERS AND STREAMS. BASED ON CURRENT
FORECASTS ONLY DELTA DAM ON THE MOHAWK RIVER IS EXPECTED TO EXCEED
FLOOD STAGE AND THIS IS EXPECTED TO OCCUR TUESDAY AFTERNOON.
NATIONAL OPERATIONAL HYDROLOGIC REMOTE SENSING CENTER (NOHRSC)
SHOWS SNOWPACK LEFT ACROSS MAINLY THE SOUTHERN ADIRONDACKS...HIGHER
TERRAIN OF THE EASTERN CATSKILLS AND ACROSS SOUTHERN VERMONT AND
THE NORTHERN BERKSHIRES. THE HIGHEST SNOW WATER EQUIVALENT IS
ACROSS THE HIGHER TERRAIN OF THE SOUTHERN GREEN MOUNTAINS WHERE
THERE IS STILL 6 UP TO POSSIBLY 12 INCHES.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...IAA/11
NEAR TERM...11
SHORT TERM...11
LONG TERM...FRUGIS/KL
AVIATION...FRUGIS/KL
FIRE WEATHER...11
HYDROLOGY...IAA/11
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
412 AM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTH TODAY AND TONIGHT THEN
PASS THROUGH THE AREA WEDNESDAY. A WEDGE OF HIGH PRESSURE WILL
DEVELOP BEHIND THE FRONT AND STRENGTHEN THURSDAY AS A COASTAL
TROUGH DEVELOPS OFFSHORE. THE TROUGH WILL LIFT NORTHEAST UP THE
COAST FRIDAY...BEFORE A WEAK COLD FRONT CROSSES THE REGION LATE
SATURDAY. ANOTHER STORM SYSTEM IS EXPECTED TO IMPACT THE AREA LATE
WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
WARM FRONTAL REMNANTS ARE NOW NORTH OF THE FORECAST AREA PER
14/07Z SURFACE OBSERVATIONS. THE DECAYING BOUNDARY WILL CONTINUE
TO LIFT NORTH TODAY AND DISSIPATE AS LOW PRESSURE MOVES INTO THE
SOUTHERN APPALACHIANS ALONG AN ADVANCING COLD FRONT. 14/00Z UPPER
ANALYSIS DID NOT IDENTIFY ANY SIGNIFICANT UPSTREAM IMPULSES THAT
WILL CROSS THE AREA AT PEAK HEATING...SO EXPECT A MAINLY DIURNAL
CONVECTIVE PATTERN TO PREVAIL WITH THE AREA REMAINING ALONG THE
CONVERGENT SIDE OF THE MID-LEVEL RIDGE AXIS.
THERE APPEARS TO BE TWO FAVORED AREAS FOR ENHANCED CONVECTIVE
DEVELOPMENT TODAY. THE FIRST WILL BE ACROSS THE INTERIOR
PORTIONS OF SOUTHEAST SOUTH CAROLINA...ROUGHLY IN THE WALTERBORO-
JAMESTOWN...NORTH CHARLESTON CORRIDOR WHERE LOW-LEVEL CONVERGENCE
WILL BECOME MAXIMIZED BETWEEN THE INLAND MOVING SEA BREEZE AND THE
LAKE BREEZES AROUND LAKES MARION AND MOULTRIE. THE OTHER WILL BE
THE AREA SOUTH OF I-16...ESPECIALLY NEAR THE ALTAMAHA RIVER...WHERE
SCATTERED CONVECTION ASSOCIATED WITH THE GULF COAST SEA BREEZE
MOVING NORTHEAST OFF APALACHEE BAY WILL LIKELY APPROACH LATE AND
INTERACT WITH THE ATLANTIC SEA BREEZE. IT IS HARD TO JUSTIFY POPS
ANY HIGHER THAN 40-50 PERCENT IN THESE AREAS IN THE ABSENCE OF A
SIGNIFICANT UPPER LEVEL FORCING MECHANISM...BUT LOCALLY HIGHER
POPS MAY EVENTUALLY BE NEEDED AS SHORT TERM CONVECTIVE AND SURFACE
MESOSCALE TRENDS BECOME MORE APPARENT LATER TODAY. SHOWERS/TSTMS
WILL BE MORE SPORADIC AND MAINLY DRIVEN BY AIRMASS DESTABILIZATION
FOR THE REMAINING PORTIONS OF THE FORECAST AREA. THIS JUSTIFIES
POPS OF 20-30 PERCENT. THERMODYNAMIC PROFILES ARE NOT OVERLY
IMPRESSIVE PER MODIFIED MODEL POINT SOUNDINGS SO THE RISK FOR
SEVERE TSTMS LOOK MINIMAL...ALTHOUGH GUSTY WINDS...TORRENTIAL
DOWNPOURS AND CLOUD-TO-GROUND LIGHTNING STRIKES WILL STILL POSE A
HAZARD.
EXTENSIVE CLOUD COVER THIS MORNING WILL GRADUALLY THIN WITH TIME
WITH SKIES LIKELY BECOMING PARTLY CLOUDY FOR MANY AREAS. THIS
INCREASED INSOLATION COUPLED WITH 850 HPA TEMPERATURES RISING TO
14-16C WILL SUPPORT HIGHS IN THE MID-UPPER 80S. THERE IS EVEN AN
OUTSIDE SHOT OF A FEW 90 DEGREE READINGS IN THE I-95 CORRIDOR FROM
ROUGHLY SAVANNAH SOUTH TO DARIEN...INCLUDING LUDOWICI AND
HINESVILLE. THE RAP/NAM12 AND H3R ALL SHOW READINGS 87-89 DEGREES
IN THIS AREA BEFORE THE ARRIVAL OF THE ATLANTIC SEA BREEZE AND
CONVECTION MOVING IN FROM THE SOUTHWEST.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
TONIGHT...DIURNAL SHOWER/TSTM ACTIVITY WILL GRADUALLY DIMINISH WITH
THE LOSS OF INSOLATION...ALTHOUGH IT MAY TAKE A GOOD PORTION OF
THE EVENING FOR THE ACTIVITY PROPAGATING IN AHEAD OF THE GULF
COAST SEA BREEZE TO PUSH OFF THE GEORGIA COAST. EXPECT MAINLY DRY
CONDITIONS TO PREVAIL FOR A GOOD PORTION THE NIGHT. A BACKDOOR
COLD FRONT WILL APPROACH FROM THE NORTH LATE...BUT THIS BOUNDARY
SHOULD REMAIN NORTH OF THE SANTEE RIVER THROUGH SUNRISE. THERE MAY
BE JUST ENOUGH LOW-LEVEL CONVERGENCE AHEAD OF THE FRONT TO SUPPORT
ISOLATED SHOWERS ACROSS THE CHARLESTON TRI-COUNTY AREA AFTER 4-5
AM...SO SLIGHT CHANCE POPS WILL BE DEPICTED IN THIS AREA. IT WILL
OTHERWISE BE ANOTHER WARM AND HUMID NIGHT WITH LOWS ONLY DROPPING
INTO THE UPPER 60S.
WEDNESDAY...AT DAYBREAK A BACKDOOR COLD FRONT WILL BE SLOWLY
DESCENDING SOUTH INTO THE NORTHERN PORTIONS OF THE FORECAST AREA. AS
THE FRONT SINKS FURTHER SOUTH THROUGH THE DAY...A WEDGE OF HIGH
PRESSURE WILL DEVELOP BEHIND IT. CONTINUED DEEP MOISTURE FEED FROM
THE TROPICAL PACIFIC AND GULF OF MEXICO WILL RESULT IN PWATS OF
AROUND 1.75 INCHES...OR ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL.
THIS IN COMBINATION WITH SHORTWAVE ENERGY EJECTING OUT THE SOUTHWEST
FLOW WILL RESULT IN HIGH CHANCE/LIKELY POPS. WEAK INSTABILITY MAINLY
IN SOUTHEAST GEORGIA WILL KEEP A SLIGHT CHANCE OF THUNDER MENTION IN
THE FORECAST IN THE AFTERNOON. OTHER CONVECTIVE PARAMETERS ARE
RATHER POOR SO SEVERE THREAT IS PRETTY LOW. BY SUNSET...THE FRONT
SHOULD BE LOCATED NEAR OR SOUTH OF THE ALTAMAHA. HIGH TEMPERATURES
WILL RANGE FROM THE MID 70S IN OUR NORTHERN ZONES...TO AROUND 80
SOUTH. WEDNESDAY NIGHT...THE ILL-DEFINED FRONT WILL TRANSITION INTO
A COASTAL TROUGH...ACTING TO STRENGTHEN THE INLAND HIGH PRESSURE
WEDGE. ELEVATED MOISTURE AND ENHANCED LOW LEVEL CONVERGENCE WILL
KEEP SHOWERS IN THE FORECAST OVERNIGHT. LOWS WILL BE RANGE FROM THE
UPPER 50S TO MID 60S.
THURSDAY...THE COASTAL TROUGH WILL LIKELY CLOSE OFF AS A SURFACE LOW
AND BEGIN TO MOVE NORTHEAST UP THE COAST. HIGHEST RAIN CHANCES WILL
BE IN MORNING/EARLY AFTERNOON BEFORE THE BEST MOISTURE SHIFTS NORTH
WITH THE SURFACE LOW. COOL NORTH/NORTHEAST FLOW AND OVERCAST SKIES
WILL KEEP HIGHS BELOW NORMAL...RANGING FROM THE UPPER 60S TO LOW/MID
70S. THURSDAY NIGHT...THE WEDGE WILL BEGIN TO WEAKEN AS THE LOW
CONTINUES TO LIFT NORTHEAST ALONG THE CAROLINA COAST. THERE WILL
LIKELY BE SOMEWHAT OF A BREAK IN PRECIPITATION AND FORECAST
CURRENTLY ONLY HAS SLIGHT CHANCE/CHANCE POPS. LOWS WILL BE IN THE
UPPER 50S/LOW 60S.
FRIDAY...FRIDAY WILL BE MORE OF A TRANSITIONAL DAY WITH A RATHER
WEAK/DIFFUSE PRESSURE PATTERN. DESPITE THE FORECAST AREA REMAINING
UNDER THE PERSISTENT MOISTURE FEED...RAIN CHANCES WILL BE CAPPED AT
20-30 PERCENT SINCE THERE DOES NOT SEEM TO BE MUCH FOCUS OR FORCING
CONVECTION. HIGH TEMPERATURES WILL MODERATE BACK TO NORMAL...IN THE
MID/UPPER 70S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODELS HAVE BEEN PRETTY INCONSISTENT IN THE LONG TERM PERIOD SO
FORECAST CONFIDENCE IS QUITE LOW. A WEAK COLD FRONT WILL DROP
THROUGH THE REGION LATE SATURDAY. TRANSIENT HIGH PRESSURE WILL
PREVAIL ON SUNDAY AHEAD OF THE NEXT STORM SYSTEM BREWING IN THE
MIDWEST WHICH WILL AFFECT THE FORECAST AREA EARLY NEXT WEEK.
ELEVATED MOISTURE AND A SERIES OF UPPER LEVEL DISTURBANCES WILL
KEEP RAIN CHANCES IN THE FORECAST FOR MUCH OF THE PERIOD.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
KCHS...WARM FRONT NOW NORTH OF THE TERMINAL. WATCHING FOR A PERIOD
OF LOW CLOUDS OVER THE NEXT FEW HOURS...MAINLY 09-12Z. GUIDANCE
MIXED DURING THIS TIME...BUT GENERALLY FAVORS VFR. WITH AREA
OBSERVATIONS SHOWING SOME MVFR CIGS AROUND...WILL SHOW MVFR CIGS
09-12Z WITH A TEMPO VFR DURING THAT TIME. VFR FROM SUNRISE ON.
SCATTERED SHOWERS/TSTMS WILL LIKELY DEVELOP NORTHWEST OF THE
TERMINAL THIS AFTERNOON. CONFIDENCE TO LOW TO INCLUDE A MENTION
ATTM AND WILL BE REEVALUATED WITH THE 12Z TAF CYCLE.
KSAV...IFR CIGS ARE VERY NEAR THE TERMINAL...MAINLY TO THE NORTH.
THERE IS A SOLID CHANCE THESE CIGS WILL BUILD DOWN TO IMPACT THE
TERMINALS FOR A FEW HOURS PER RAP SOUNDINGS. WILL SHOW A TEMPO
GROUP FROM 08-10Z OF IFR BKN008 TO COVER THIS. OTHERWISE...EXPECT
VFR CONDITIONS TO PREVAIL. IF IFR CIGS TO DEVELOP...THEY MAY
LINGER LONGER THAN INDICATED...BUT THIS IS AGAINST THE GUIDANCE
MEAN. A CLUSTER OF SHOWERS/TSTMS DEVELOPING ALONG THE GULF SEA
BREEZE MAY APPROACH THE TERMINAL AFTER SUNSET. LOW CONFIDENCE
SHOWERS/TSTMS WILL REACH THAT FAR WITH DIMINISHING INSTABILITY
LATE AFTERNOON BEHIND THE ATLANTIC SEA BREEZE. WILL NOT INCLUDE A
MENTION ATTM AND WILL BE REEVALUATED WITH THE 12Z TAF CYCLE.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY AT TIMES
THROUGH THE WEEK AS PERIODIC SHOWERS/TSTMS IMPACT THE TERMINALS.
&&
.MARINE...
TODAY...SOUTH TO SOUTHWEST WINDS WILL PREVAIL TODAY WITH WINDS
GENERALLY 10 KT OR LESS. A ROBUST SEA BREEZE WILL TAKE SHAPE ALONG
THE BEACHES BY EARLY AFTERNOON...WHICH WILL ENHANCE WIND FIELDS
NEAR THE BEACHES AND THE CHARLESTON HARBOR. WINDS SHOULD REACH AS
HIGH AS 15 KT IN THE CHARLESTON HARBOR FOR MID-LATE AFTERNOON AS
THE SEA BREEZE MOVES INLAND. LOWS WILL AVERAGE 2-4 FT...HIGHEST
OFFSHORE WATERS.
TONIGHT...SOUTHWEST WINDS AROUND 10 KT WILL PREVAIL AHEAD OF AN
ADVANCING COLD FRONT. SEAS WILL AVERAGE 2-3 FT.
WEDNESDAY THROUGH MONDAY...A BACKDOOR COLD FRONT WILL DESCEND SOUTH
ACROSS THE WATERS ON WEDNESDAY...WITH A WEDGE OF HIGH PRESSURE
BUILDING IN ITS WAKE. WEDNESDAY NIGHT INTO THURSDAY...A COASTAL
TROUGH WILL DEVELOP OFFSHORE ALLOWING THE INLAND WEDGE TO
STRENGTHEN. GIVEN A TIGHTENING PRESSURE GRADIENT AND DECENT PRESSURE
RISES...WINDS AND SEAS WILL BUILD. SMALL CRAFT ADVISORIES MAY BE
NEEDED FOR WEDNESDAY NIGHT INTO THURSDAY...ESPECIALLY ACROSS THE
SOUTH CAROLINA COASTAL WATERS...AS NORTHEAST WINDS GUST TO 25 KT AND
SEAS BUILD TO 4-6 FEET. IN ADDITION...THERE WILL BE AN ENHANCED RISK
OF RIP CURRENTS DURING THIS TIME. THURSDAY NIGHT...THE COASTAL
TROUGH WILL CLOSE OFF AND BEGIN TO MOVE NORTHEAST UP THE COAST
ALLOWING THE PRESSURE GRADIENT TO RELAX. TRANSIENT HIGH PRESSURE
WILL PREVAIL FRIDAY BEFORE A WEAK COLD FRONT IMPACTS THE WATERS
SATURDAY NIGHT. AT THIS TIME...WINDS/SEAS ARE EXPECTED TO REMAIN
BELOW HEADLINE CRITERIA. ANOTHER STORM SYSTEM IS EXPECTED TO AFFECT
REGION EARLY NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
A COMBINATION OF ASTRONOMICAL HIGH TIDES AND LEFTOVER NORTHEAST
WINDS/SWELL WILL RESULT IN A THREAT FOR SHALLOW COASTAL FLOODING
NEAR THE TIME OF HIGH TIDE THURSDAY AND FRIDAY EVENING...PERHAPS
EXTENDING INTO THE SATURDAY EVENING HIGH TIDE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/ECT
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1258 AM EDT TUE APR 14 2015
.SYNOPSIS...
THE REMNANTS OF A WARM FRONT WILL LIFT SLOWLY NORTH ACROSS THE
AREA TONIGHT. A COLD FRONT WILL APPROACH THE REGION TUESDAY...THEN
BACKDOOR ACROSS THE AREA LATE TUESDAY NIGHT. A WEDGE OF HIGH PRESSURE
WILL DEVELOP INTO LATE WEEK...BEFORE A WEAK COLD FRONT CROSSES THE
REGION LATE SATURDAY. HIGH PRESSURE WILL BRIEFLY RETURN SUNDAY WITH
ANOTHER STORM SYSTEM IMPACTING THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
14/04Z MESOANALYSIS PLACED WARM FRONTAL REMNANTS NORTH OF THE
FORECAST AREA--ROUGHLY KAIK-KOGB-KGGE. THIS BOUNDARY WILL CONTINUE
TO MEANDER NORTH WITH THE ENTIRE AREA EMBEDDED WITHIN A WARM/HUMID
AIRMASS. TEMPERATURES WILL FALL LITTLE OVERNIGHT...ONLY DROPPING
INTO THE UPPER 60S FOR MOST AREA. SCATTERED RAIN SHOWERS WILL
PERSIST IN THE WARM AIR ADVECTION REGIME...BUT COVERAGE SHOULD
DIMINISH THROUGH THE OVERNIGHT HOURS. ADJUSTED NEAR TERM POPS AND
TEMPERATURES TO MATCH CURRENT TRENDS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
A DEEP PLUME OF MOISTURE FROM THE GULF OF MEXICO AND THE TROPICAL
PACIFIC WILL CONTINUE TO FEED INTO THE REGION FROM THE SOUTHWEST
DURING THIS PERIOD. MEANWHILE VARIOUS UPPER LEVEL DISTURBANCES WILL
MOVE THROUGH THE AREA AND RESULT IN HIGHER RAIN CHANCES AS THEY MOVE
THROUGH.
TUESDAY...THE FORECAST AREA WILL BE LOCATED SOLIDLY IN THE WARM
SECTOR WITH SOUTH TO SOUTHWEST WINDS HELPING TO BRING MID TO UPPER
60S DEWPOINTS INTO THE AREA. PRECIPITABLE WATER VALUES NEAR 1.9
INCHES IN THE MORNING WILL DROP SOME BY THE AFTERNOON AS MID AND
UPPER LEVEL MOISTURE ASSOCIATED WITH AN UPPER LEVEL DISTURBANCE
SHIFT AWAY FROM THE AREA. DESPITE WEAK SUBSIDENCE IN THE WAKE OF
THIS DISTURBANCE...STILL EXPECT THERE TO BE A DECENT CHANCE FOR
SHOWERS AND THUNDERSTORMS...ALTHOUGH CONFIDENCE IN POPS IS QUITE LOW
WITH THE 00Z ECMWF QUITE WET AND 12Z GFS AND CANADIAN QUITE
A BIT DRIER. NEW 12Z ECMWF CAME IN DRIER...SO WOULD NOT BE SURPRISED
IF RAIN CHANCES WOULD NEED TO BE LOWERED MORE THAN THE SLIGHT
DOWNWARD TREND THAT WAS INCORPORATED WITH THIS FORECAST PACKAGE.
THERE WILL BE DECENT INSTABILITY WITH LI/S FROM -3 TO -5 AND CAPE
VALUES FROM 800 TO 1200 J/KG...BUT WEAK SINKING MOTION AND
SOMEWHAT DRIER AIR IN THE MID AND UPPER LEVELS SHOULD KEEP THE
COVERAGE OF SHOWERS AND THUNDERSTORMS LOWER THAN WHAT IT COULD BE.
A FEW OF THE THUNDERSTORMS COULD BECOME STRONG...ESPECIALLY IF THE
WARMER HIGHS OF THE MAV GUIDANCE MATERIALIZE. ANY SLOW MOVING
THUNDERSTORMS COULD PRODUCE LOCALLY HEAVY RAINFALL. MADE A BIT OF
AN UPWARD ADJUSTMENTS TO HIGHS...MAINLY LOWER TO MID 80S...BUT
STILL QUITE A BIT BELOW THE VERY WARM MAV GUIDANCE.
TUESDAY NIGHT...WIDELY SCATTERED TO SCATTERED EVENING SHOWERS AND
THUNDERSTORMS...SOME WITH HEAVY RAINFALL SHOULD DIMINISH BY LATE
EVENING. A BACKDOOR COLD FRONT COULD BE PUSHING INTO FAR NORTHERN
AREAS LATE. IT WILL BE MILD WITH LOW TEMPERATURES MAINLY IN THE
MID 60S.
WEDNESDAY...THE BACKDOOR COLD FRONT WILL PUSH THROUGH MUCH OF
THE AREA AS A WEDGE OF SURFACE HIGH PRESSURE BEGINS TO WEDGE DOWN
EAST OF THE APPALACHIAN MOUNTAINS. CONTINUED DEEP LAYERED MOISTURE
IN COMBINATION WITH ENHANCED LOW LEVEL CONVERGENCE
WILL KEEP CHANCE/LIKELY POPS IN THE FORECAST. HIGHS SHOULD RANGE
FROM THE LOWER 70S NORTHWEST TO NEAR 80 NEAR THE ALTAMAHA IN
SOUTHEAST GEORGIA.
WEDNESDAY NIGHT INTO THURSDAY...THE HIGH PRESSURE WEDGE WILL
STRENGTHEN AS A COASTAL TROUGH DEVELOPS OFFSHORE. MODELS DEPICT THE
TROUGH CLOSING OFF INTO A SURFACE LOW AND EITHER REMAINING
STATIONARY FOR A TIME OR MOVING SLOWLY NORTH/NORTHEAST UP THE
COAST ON THURSDAY. BEST THREAT FOR RAIN WILL BE OVER/NEAR COASTAL
WATERS ON THURSDAY...CLOSER TO THE AREA OF LOW PRESSURE. COOL
NORTH/NORTHEAST FLOW AND OVERCAST SKIES WILL LIMIT HIGHS TO THE
UPPER 60S NORTHWEST TO UPPER 70S SOUTH.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE WEATHER PATTERN WILL CONTINUE TO BE UNSETTLED AND COMPLEX. ON
FRIDAY...A SURFACE LOW WILL BE POSITIONED OFF THE CAROLINA COAST AND
WILL LIFT NORTHEAST THROUGH THE DAY. ON SATURDAY...A WEAK BACKDOOR
COLD FRONT WILL CROSS THROUGH THE REGION WITH HIGH PRESSURE BUILDING
IN FROM THE NORTH BEHIND IT. THE HIGH WILL BE SHORT-LIVED AS THE
NEXT LOW PRESSURE SYSTEM DEVELOPS OVER THE SOUTHERN STATES LATE IN
THE WEEKEND. THERE ARE SOME MODEL DISCREPANCIES WITH DETAILS IN THE
LONG TERM...HOWEVER FAVORABLE MOISTURE AND A SERIES OF SHORTWAVES
WILL SUPPORT CHANCES FOR SHOWERS/THUNDERSTORMS MUCH OF THE PERIOD.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
KCHS...WARM FRONT NOW NORTH OF THE TERMINAL. WATCHING FOR A PERIOD
OF LOW CLOUDS OVER THE NEXT FEW HOURS...MAINLY 09-12Z. GUIDANCE
MIXED DURING THIS TIME...BUT GENERALLY FAVORS VFR. WITH AREA
OBSERVATIONS SHOWING SOME MVFR CIGS AROUND...WILL SHOW MVFR CIGS
09-12Z WITH A TEMPO VFR DURING THAT TIME. VFR FROM SUNRISE ON.
SCATTERED SHOWERS/TSTMS WILL LIKELY DEVELOP NORTHWEST OF THE
TERMINAL THIS AFTERNOON. CONFIDENCE TO LOW TO INCLUDE A MENTION
ATTM AND WILL BE REEVALUATED WITH THE 12Z TAF CYCLE.
KSAV...IFR CIGS ARE VERY NEAR THE TERMINAL...MAINLY TO THE NORTH.
THERE IS A SOLID CHANCE THESE CIGS WILL BUILD DOWN TO IMPACT THE
TERMINALS FOR A FEW HOURS PER RAP SOUNDINGS. WILL SHOW A TEMPO
GROUP FROM 08-10Z OF IFR BKN008 TO COVER THIS. OTHERWISE...EXPECT
VFR CONDITIONS TO PREVAIL. IF IFR CIGS TO DEVELOP...THEY MAY
LINGER LONGER THAN INDICATED...BUT THIS IS AGAINST THE GUIDANCE
MEAN. A CLUSTER OF SHOWERS/TSTMS DEVELOPING ALONG THE GULF SEA
BREEZE MAY APPROACH THE TERMINAL AFTER SUNSET. LOW CONFIDENCE
SHOWERS/TSTMS WILL REACH THAT FAR WITH DIMINISHING INSTABILITY
LATE AFTERNOON BEHIND THE ATLANTIC SEA BREEZE. WILL NOT INCLUDE A
MENTION ATTM AND WILL BE REEVALUATED WITH THE 12Z TAF CYCLE.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY AT TIMES
THROUGH THE WEEK AS PERIODIC SHOWERS AND T-STORMS IMPACT THE
TERMINALS.
&&
.MARINE...
TONIGHT...CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY
THRESHOLDS AS A WARM FRONT SLOWLY LIFTS NORTH OF THE WATERS
OVERNIGHT. IN GENERAL...SOUTHERLY WINDS WILL REMAIN AT OR BELOW 15
KTS...HIGHEST AFTER MIDNIGHT. SEAS WILL RANGE BETWEEN 2-4
FT...HIGHEST IN OFFSHORE GEORGIA WATERS.
TUESDAY THROUGH SUNDAY...ON TUESDAY THE WATERS WILL BE HIGHLY
INFLUENCED BY ATLANTIC HIGH PRESSURE. A COLD FRONT IS EXPECTED TO
DESCEND SOUTH ACROSS THE WATERS LATE TUESDAY NIGHT INTO
WEDNESDAY...WITH A WEDGE OF HIGH PRESSURE DEVELOPING IN ITS WAKE. A
TIGHTENED PRESSURE GRADIENT AND SLIGHT PRESSURE RISES WILL RESULT AN
A NORTHEAST WIND SURGE LATE WEDNESDAY AND THURSDAY. SMALL CRAFT
ADVISORIES MAY EVENTUALLY BE NEEDED...ESPECIALLY FOR THE SOUTH
CAROLINA COASTAL WATERS...AS WINDS AND SEAS BUILD. IN
ADDITION...THERE LIKELY WILL BE AN ELEVATED RISK OF RIP CURRENTS
DURING DURING THE MID TO LATE WEEK TIME FRAME. ON THURSDAY...THE
INLAND WEDGE WILL STRENGTHEN AS A COASTAL TROUGH DEVELOPS AND CLOSES
OFF INTO A SURFACE LOW. THE LOW REMAINS STATIONARY FOR A TIME OR
MOVES NORTHEAST UP THE COAST THURSDAY INTO FRIDAY. SIGNIFICANT
UNCERTAINLY IN WIND DIRECTION AND SPEED DURING THIS PERIOD DUE TO
UNCERTAINTY OF SURFACE LOW POSITION...MOVEMENT AND STRENGTH. SEAS
WILL STILL REMAIN ELEVATED HOWEVER...EVEN IF THE WINDS DECREASE FOR
A TIME.
A COMBINATION OF ASTRONOMICAL HIGH TIDES AND THE LEFTOVER NORTHEAST
WINDS/SWELL...THERE IS A THREAT FOR SHALLOW COASTAL FLOODING NEAR
THE TIME OF HIGH TIDE FRIDAY EVENING...PERHAPS EXTENDING INTO THE
SATURDAY EVENING HIGH TIDE. GENERALLY MORE TRANQUIL CONDITIONS
EXPECTED THIS WEEKEND IN THE WAKE OF THE LOW PRESSURE AREA.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS POCATELLO ID
338 AM MDT TUE APR 14 2015
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT.
MODELS BEGINNING TO COME TO SOME AGREEMENT ON SYSTEM TODAY THROUGH
WEDNESDAY WHICH WILL BRING WIND AND SNOW TO SOUTHEAST IDAHO.
LATEST 06Z NAM CLOSES OFF NEGATIVE TILT 500 MILLIBAR TROF OVER
SOUTHERN IDAHO LATE TONIGHT AND MOVES IT INTO SOUTHWEST WYOMING
THROUGH WEDNESDAY MORNING. THE 00Z GFS WAS IN DECENT AGREEMENT NOW
ALSO CLOSING OFF UPPER LOW IN SOUTHERN IDAHO AND MOVING INTO
SOUTHWEST WYOMING THROUGH WEDNESDAY MORNING. THE EUROPEAN REMAINS
MUCH FURTHER SOUTH WITH THE UPPER LOW IN CENTRAL UTAH BY WEDNESDAY
MORNING AND ALSO SLOWER WITH MOVEMENT. THE INITIAL PROBLEM WILL BE
STRONG WINDS WITH THE COLD FRONT MOVING QUICKLY THROUGH EASTERN
IDAHO LATER THIS MORNING THROUGH EARLY AFTERNOON. KEPT WIND
WARNINGS AND ADVISORIES IN PLACE WITH MODELS SHOWING SOME 35 MPH
SUSTAINED WINDS IN MAGIC VALLEY AND SNAKE PLAIN AND SOUTH CENTRAL
HIGHLANDS. EXPECT SNOW TO DEVELOP BEHIND THE COLD FRONT INITIALLY
IN CENTRAL MOUNTAINS THIS MORNING THEN FOCUSED ON THE SOUTHERN AND
EASTERN HIGHLANDS AND SNAKE RIVER PLAIN OVERNIGHT TONIGHT. FOR NOW
CONTINUED WITH 1 TO 3 INCHES IN CENTRAL MOUNTAINS AND SNAKE RIVER
PLAIN WITH 4 TO 8 INCHES EXPECTED IN IDAHO WASATCH AND CARIBOU
HIGHLANDS WHERE A WINTER WEATHER ADVISORY REMAINS IN EFFECT THIS
AFTERNOON THROUGH WEDNESDAY MORNING. THE COMBINATION OF SNOW AND
WINDS WILL LIKELY PRODUCE SOME DIFFICULT DRIVING CONDITIONS THIS
AFTERNOON AND ESPECIALLY OVERNIGHT TONIGHT ONCE THE SUN SETS.
TEMPERATURES WILL TURN SHARPLY COLDER THIS AFTERNOON BEHIND THE
COLD FRONT AND REMAIN WELL BELOW NORMAL WEDNESDAY. EXPECT DRY AND
SUNNY CONDITIONS THURSDAY WITH A RETURN TO SEASONABLE
TEMPERATURES.
GK
.LONG TERM...FRIDAY THROUGH NEXT MONDAY. MODELS CONSISTENT IN
DEVELOPING UPPER RIDGING INTO PAC NW THURSDAY NIGHT AS CUTOFF LOW
DROPS TO THE FOUR CORNERS AREA. A QUICK MOVING DISTURBANCE WILL
CROSS NORTHERN IDAHO AND MONTANA SATURDAY WITH LIMITED SHOWER
ACTIVITY IN THE UPPER SNAKE HIGHLANDS. THE MAIN CHANGE TO THE
FORECAST IS SATURDAY NIGHT AND SUNDAY WHERE THE SHARP RIDGE AXIS
CLOSE TO THE COAST RESULTS IN MORE NORTHERLY FLOW ALONG THE WYOMING
BORDER AND THUS SOME RISK OF LIGHT SHOWERS IN THE EASTERN HIGHLANDS. RS
&&
.AVIATION....MOST NOTABLY FOR PIH AND IDA. KSFX RADAR VAD WINDS
SHOWS SOUTH WINDS 40-50 KTS CLOSE TO 2000 FEET OFF THE SURFACE AHEAD
OF A STRONG COLD FRONT. THE NAM12 AND HRRR MODELS HAVE THE TIGHT
SURFACE PRESSURE GRADIENT OVER MALAD AND BEAR LAKE AREA SHIFTING
EAST BY 12Z THIS MORNING. THAT WOULD FAVOR THE CURRENT THREAT OF
LLWS ENDING 1 TO 2 HOURS AHEAD OF THE CURRENT TAF TIMING. PASSAGE OF
THE FRONT AT KPIH SHOULD BE NEAR 14Z. VERY IMPRESSIVE SURFACE POST
FRONTAL PRESSURE GRADIENT TODAY. HIGH WIND WARNING IN EFFECT FROM
NOON TO 15/04Z. ALL 3 SNAKE PLAIN TAF SITES ARE INCLUDED. SNOW
LEVELS FALL TO VALLEY FLOORS OVERNIGHT WHICH BRINGS SNOW SHOWERS
WITH MVFR CEILINGS AT KIDA AND KPIH 15/04-09Z.
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM NOON TODAY TO 10 PM MDT THIS EVENING
IDZ017-021-022.
WIND ADVISORY FROM NOON TODAY TO 10 PM MDT THIS EVENING IDZ020.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON MDT
WEDNESDAY ABOVE 5500 FEET FOR THE IDZ023-025.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1239 AM CDT TUE APR 14 2015
.SHORT TERM...
210 PM CDT
THROUGH TUESDAY NIGHT...
SATELLITE IMAGERY THIS AFTERNOON SHOWS THE CHANNEL OF CLOUDS
STRETCHING FROM HUDSON BAY CANADA SOUTH THROUGH THE OHIO
VALLEY...WITH THE BOUNDARY STEADILY PUSHING EAST. ON THE HEELS OF
THE DEPARTING BOUNDARY IS A BROAD ANTI-CYCLONIC RIDGE...WHICH IS
POISED TO ARRIVE THIS EVENING AND PERSIST THROUGH MID-WEEK. THROUGH
THIS AFTERNOON THE LEADING EDGE OF THE SFC RIDGE WILL REMAIN OVER
THE CWFA...ALLOWING SLIGHTLY TIGHTER PRESSURE GRADIENT TO CREATE
OCCASIONALLY GUSTY WEST/NORTHWEST WINDS. TEMPS BEHIND THE FRONTAL
BOUNDARY ARE RATHER UNIFORM IN THE LOW/MID 60S WITH DEW POINTS
FALLING INTO THE LOW 30S.
HIGH PRESSURE WILL PROVIDE MINIMAL CLOUD COVER THRU TUE NGT...WITH
SEASONAL TEMPS IN THE 60S. AS THE SFC RIDGE AXIS BEGINS TO DRIFT
NORTHEAST TUE...THIS WILL ALLOW WINDS TO TURN NORTH/NORTHEAST.
LIKELY KEEPING MUCH COOLER TEMPS ALONG THE IMMEDIATE LAKESHORE.
CONFIDENCE...HIGH.
BEACHLER
&&
.LONG TERM...
210 PM CDT
WEDNESDAY THROUGH MONDAY...
A DEVELOPING 500MB TROUGH ACROSS THE FOUR-CORNERS REGION OF THE
CONUS...WILL HELP TO TRANSITION THE SEMI- ZONAL FLOW TO A SLIGHT
SOUTHWEST ORIENTATION. THE SFC RIDGE WILL BE STEADILY SLIDING
NORTHEAST WED AFTN...WITH A SLOW ARRIVAL TO RETURN FLOW MOISTURE
WED NGT. MOISTURE WILL CONTINUE TO POOL ALONG THE WESTERN
PERIPHERY OF THE DEPARTING SFC RIDGE...AS THE 500MB VORT REMAINS
PARKED ACROSS THE SOUTHWEST CONUS THUR/FRI. THIS WILL ALLOW A
SERIES OF WEAK IMPULSES TO LIFT NORTHEAST AND BRING CHANCES FOR
SHRA/TSRA. FRI INTO SAT LOOKS TO BE BETWEEN MID-LVL
WAVES...HOWEVER BY SAT A NORTHERN STREAM MID-LVL WAVE WILL BE
DIGGING SOUTHEAST ACROSS THE NORTHERN PLAINS...THIS COULD BLEND
WITH A SOUTHERN STREAM WAVE AND BRING ANOTHER ROUND OF SHRA/TSRA
TO THE REGION FOR THE UPCOMING WEEKEND. TEMPS THRU THE EXTENDED
PERIOD REMAIN SEASONAL...HOWEVER WITH THE NORTHERN STREAM BECOMING
ACTIVE...TEMPS MAY BEGIN TO COOL FOR THE UPCOMING WEEKEND.
CONFIDENCE IN TEMPERATURES...HIGH.
CONFIDENCE IN PRECIPITATION...MEDIUM.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LIGHT WEST-NORTHWEST WINDS BECOMING NORTHEAST BY TUESDAY
MORNING...WITH A LAKE BREEZE PUSH AND WINDS BECMG ENELY NEAR 10
KT TUESDAY AFTERNOON.
KREIN
//DISCUSSION...UPDATED 06Z...
A LARGE AREA OF HIGH PRESSURE EXTENDS FROM THE EASTERN GREAT LAKES
TO WEST TEXAS WITH LOW PRESSURE OVER HUDSON BAY AND ANOTHER LOW
OVER THE TN VALLEY. WINDS WILL CONTINUE TO DIMINISH OVERNIGHT TO
NR LGT/VRBL AS THE CENTER OF THE HIGH MOVES ACROSS NRN IL/SRN WI
TUESDAY MORNING. WINDS WILL SHIFT TO THE NORTH-NORTHEAST THROUGH
THE EARLY MORNING HOURS AND BECOME MORE TRUE NORTHEAST ARND 5-7KT
BY MID DAY AS THE HIGH LIFTS TO THE NORTHEAST ACROSS THE GREAT
LAKES. WITH A VERY WEAK GRADIENT IN PLACE...A LAKE BREEZE PUSH
WILL LIKELY DEVELOP BY EARLY-MID AFTERNOON WHICH WILL RESULT IN A
PERIOD OF NORTHEAST OR EAST-NORTHEAST WINDS NEAR 10 KTS FOR A
TIME. LIGHT EAST-NORTHEAST WINDS WILL CONTINUE TUESDAY EVENING.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH CONFIDENCE IN LAKE BREEZE DETAILS TUESDAY.
* HIGH CONFIDENCE ALL OTHER ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. BECOMING MVFR WEDNESDAY NIGHT WITH SHRA/TSRA.
EAST WINDS.
THURSDAY...SHRA/TSRA ENDING. MVFR POSSIBLE BUT BECOMING VFR.
LIGHT EAST WINDS.
FRIDAY...VFR. SLGT CHANCE OF SHRA FRIDAY NIGHT. LIGHT NORTHEAST
WINDS.
SATURDAY...VFR. NORTHEAST WINDS.
SUNDAY...VFR. CHANCE SHRA. EAST-SOUTHEAST WINDS.
RATZER
&&
.MARINE...
222 PM CDT
THE COLD FRONT HAS CLEARED THE LAKE EARLY THIS AFTERNOON RESULTING
IN WEST WINDS TO 25 KT. EXPECT A STEADY DECLINE IN WINDS LATE
THIS AFTERNOON AND EVENING AS HIGH PRESSURE OVER THE PLAINS WORKS
EASTWARD. THE CENTER OF HIGH PRESSURE WILL PASS OVER THE SOUTHERN
HALF OF THE LAKE ON TUESDAY. THIS WILL RESULT IN ONSHORE WINDS
ACROSS MUCH OF THE LAKE DUE TO THE LIGHT PRESSURE GRADIENT. THE
HIGH WILL SHIFT EAST ON WEDNESDAY AND MERGE WITH HIGH PRESSURE
JUST EAST OF HUDSON BAY...WHICH WILL RESULT IN A STEADIER
SOUTHEAST TO SOUTH WIND ACROSS THE LAKE. SEVERAL WEAK LOWS WILL
PASS BY TO THE NORTH OF THE LAKE THROUGH FRIDAY BEFORE A COLD
FRONT ARRIVES FRIDAY NIGHT INTO SATURDAY TURNING WINDS AROUND TO
THE NORTH.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1054 PM CDT Mon Apr 13 2015
.UPDATE...
ISSUED AT 825 PM CDT MON APR 13 2015
Extensive area of mid and high level cloudiness across central
through southeast Illinois as low pressure tracks well to our
south tonight. Main forecast concern will be how far north the
next batch of rain will push later tonight into Tuesday morning
as the wave passes south of our area. Latest HRRR and Rapid Refresh
models were trending a bit further north with the rain area with
areas along and south of I-70 probably seeing another round of
light rain by Tuesday morning. Will increase the POPs accordingly
over the I-70 counties after midnight. Further north, high pressure
will move across the southern Great Lakes with quite a bit of dry
air advecting south into our region overnight. Cloud cover should
keep temperatures from getting much colder than our current early
morning lows, but our far northern counties, where cloud cover will
be rather thin, may see some upper 30s by morning. Will make the
POP adjustments over our far southeast counties for late tonight
into Tuesday morning. Have already sent out some updated grids for
more cloud cover across the forecast area through Tuesday morning.
Should have the updated ZFP out soon.
&&
.SHORT TERM...(Tonight)
ISSUED AT 243 PM CDT MON APR 13 2015
19z/2pm surface analysis shows cold front departing the far SE KILX
CWA, with showers lingering along and just behind the boundary.
Based on radar timing tools and latest run of the HRRR, it appears
the showers will slip southeast of Lawrenceville by 00z. Will
therefore go with a dry forecast across the board for tonight. Band
of low clouds associated with the showers will exit the area as
well: however, plenty of high clouds will linger well behind the
front. Latest satellite imagery shows this trend quite well, with
thick cirrus seen as far northwest as central Iowa. End result will
be a high/thin overcast for much of the night, with a gradual NW to
SE clearing trend overnight. Low temperatures will range from the
upper 30s northwest of the Illinois River around Galesburg to near
50 degrees far southeast around Lawrenceville.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 243 PM CDT MON APR 13 2015
Main challenges remain with timing of precipitation chances later
this week. Latest GFS has shown a significant shift from its
previous runs in regards to the piece of energy that will be coming
onto the Pacific Northwest coast shortly, trending more toward the
ECMWF/NAM/Canadian solutions of a cutoff low over the central Rockies
by midweek. However, there are still a few differences with the
disposition of this low later in the week. Main storm track will be
along the Canadian border and upper Midwest, resulting in the low
generally meandering northeast. The GFS, which had been very
progressive later this week, is now the slowest and strongest of the
bunch, with the strong low making it as far as Arkansas by early
Sunday, while the ECMWF and Canadian models generally weaken the low
in place over west Texas/east New Mexico. That aspect results in
quite a bit of uncertainty with the PoP`s later in the weekend, but
the general model consensus is for backing down on some of the
chances in the near term.
High pressure drifting across the Midwest will keep the region dry
through much of Wednesday. Current upper low over southeast tip of
New Mexico will be shearing out, with the models bringing the
remnants into the mid-Mississippi Valley late Wednesday/early
Thursday. The ECMWF is most robust with the remaining energy and
thus have a wetter passage, while the GFS/Canadian models are
largely dry and the NAM has only small rain chances. Have focused
the rain chances mainly on Wednesday night and lowered them a bit,
as there will be a persistent east flow which will stifle the column
moistening a good part of the night. Any lingering showers should
exit early Thursday.
Heading into the weekend, most likely time frame for precipitation
would be Friday night, but confidence is still low as mentioned
earlier, and will keep the rain chances at silent 20s for now. The
differences widen by Sunday due to the much stronger GFS, which
provides a blustery/showery solution for us while the ECMWF remains
dry until Sunday evening. Did mention some 25-30% PoP`s for Sunday,
although much lower than the blended initialization would suggest.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1050 PM CDT MON APR 13 2015
VFR conditions are expected to prevail through this forecast
period. High pressure will drift across the lower Great Lakes
over the next 24 hours keeping the weather quiet for the TAF
locations. A weather disturbance passing south of the Ohio
River late tonight through Tuesday morning will keep quite a
bit of mid and high level cloud cover over most of the area
into Tuesday morning. Surface flow will be light northerly
tonight and northeast at 7 to 12 kts on Tuesday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...Barnes
LONG TERM...Geelhart
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
327 AM EDT Tue Apr 14 2015
.SHORT TERM (Now through Wednesday)...
Issued at 315 AM EDT Tue Apr 14 2015
...Flood Watch continues this morning for parts of central KY...
A solid area of rain has evolved in a WSW-ENE axis across central
KY early this morning, ahead of a pronounced shortwave in water
vapor imagery moving from AR/MS into western TN and an associated
surface low pressure system. Within this rain are numerous areas of
moderate rain. At this time, there is a distinct northern boundary
to the rain along and just south of the OH River associated with a
deformation zone. The latest few HRRR runs have shown that rain just
ahead of the shortwave may move a little farther north and be slower
to depart than previous forecasts, which the 00z NAM also hinted at.
These models are slower and farther north than the 00z GFS, which
seems reasonable. Thus, despite the current tight northern precip
edge, more showers should move back across the Louisville metro and
into at least parts of south-central IN later this morning,
continuing during much of the morning. However, the heaviest rain
should continue to fall out in an axis to the east of the shortwave.
The current Flood Watch looks good, although decent rains will fall
a county or so north of the Watch as well, but will keep the area
unchanged at this time. The overall trend should be for more bands
of showers to form east of the shortwave then rotate north and east.
This should keep highest rainfall totals in an axis from about BWG
to LEX and a row of counties or so south. Still looks like 1 to 2
inches of rain is a good bet in this axis, with locally 2+ inches
possible in a few spots. However, since rainfall is not truly
convective and since rain rates should not increase much more than
at present, widespread flash flooding is not likely. Instead,
significant ponding and some areal flooding of roads, low-lying
areas, creeks, and small streams may occur. Slightly lower rain
totals are expected over our extreme southeast south-central KY
counties. While showers will continue past the 15 UTC expiration
time of the Watch, will not change it at this time. This can be
locally extended if need be later this morning pending latest trends
and reports.
Rainfall will diminish this afternoon for most areas, but scattered
showers should continue over our east and southeast counties
overcast skies persist. Over south-central IN, some breaks in the
clouds could occur later this afternoon.
High temperatures today are tricky. Values at this time may not go
up much if any today. Matter of fact, could see readings fall a bit
as a brisk northeast wind develops along with the low clouds and
showers in parts of central KY. Will keep readings in the upper 50s
over much of east-central KY west-southwestward, with lower-mid 60s
for south-central KY, again with highest values this morning. Also,
expect lower-mid 60s in south-central IN where low clouds will scour
out and showers will end this afternoon. Lows tonight should range
from the mid 40s to lower 50s with a cloudy sky south and east, and
partly to mostly cloudy north and west.
On Wednesday, mid-level flow will begin to back again, resulting in
clouds moving back northward. There could be some scattered showers
especially across south-central KY, although there are no clear
forcing mechanics at this time. Expect highs in the mid 60s to lower
70s.
.LONG TERM (Wednesday Night through Monday)...
Issued at 325 AM EDT Tue Apr 14 2015
...Above Normal Rainfall Expected This Week...
In general terms, there is not a whole lot of change in the
guidance for the extended forecast period. The synoptic flow aloft
will be characterized by a fast northern jet flow confined to the
US/Canadian border region, while a split flow pattern will be in
place across the western US with a cut off low in the southern
stream. Multiple wave packets will eject out of the southern
stream and pass through the region in the mid-late part of the
week, bringing precipitation with the potential for heavy
rainfall. By late in the period, the cut off low over the SW US is
expected to lift out and merge with a northern stream wave which
looks to turn into a rather large gyre over the northern Great
Lakes by early next week. This would bring drier and cooler than
normal conditions to the region.
It does appear that we`ll see the first wave push through the region
on Thursday with a secondary wave coming in Friday night and early
Saturday. Combination of lift with the associated waves and plenty
of Gulf moisture will lead to widespread rainfall, some heavy, which
could result in renewed hydrologic concerns through the period.
This would be especially true across our southern half of the
forecast area...mainly south of the Parkways. The weekend does not
look to be an entire wash out, but Saturday morning will probably
remain a bit unsettled as the aforementioned wave ejects through the
region. There is a growing consensus in the data that upper level
ridging will build in during the afternoon to allow the region to
dry out a bit. Thus, will continue to run chance PoPs in the
forecast for the early part of Saturday and then allow PoPs to
decrease throughout the remainder of the day and into Sunday.
As the upper low out over the southwest US lifts out and combines
with the northern stream wave pushing through, we should see a
return of wet weather as we head into late Sunday and Monday. More
showers with some thunderstorms looks likely.
As for temperatures, have generally stuck close to the SuperBlend
consensus guidance for temperatures. This will result in daytime
highs generally in the upper 60s to the lower 70s for highs and
overnight lows in the 50s. These temperature forecasts will likely
see some sort of modulation in subsequent forecasts as the timing
issues in the upper level waves moving through the area become more
clearly defined in the coming days.
&&
.AVIATION (06Z TAF Update)...
Updated at 130 AM EDT Tue Apr 14 2015
Rain was increasing across central KY at 0530z ahead of a shortwave
trough over the lower MS Valley that was moving northeast. Ceilings
at the 3 TAF sites have been a bit variable and on the edge of
different flight categories. SDF ceiling is just between MVFR and
VFR, with BWG and LEX going from MVFR to IFR and even LIFR at times.
These same general ceiling values should hold through about 12z,
with values raising a bit thereafter, but BWG and LEX staying MVFR.
Rain will continue to spread northeast overnight and Tuesday
morning. Based on latest radar and shortwave trends, will hold onto
rain showers longer and a little farther north than previously
expected on Tuesday. Surface winds will gradually increase overnight
and especially Tuesday morning from the north-northeast at 10-15 kts
with gusts around 20 kts in response to low pressure moving east-
northeast across the TN Valley.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FLOOD WATCH until 11 AM EDT /10 AM CDT/ this morning FOR
KYZ040>043-046>049-053>057-061>067-070>078-081-082.
IN...NONE.
&&
$$
Short Term........TWF
Long Term.........MJ
Aviation..........TWF
AREA FORECAST DISCUSSION
NWS JACKSON KY
159 AM EDT TUE APR 14 2015
.UPDATE...
ISSUED AT 159 AM EDT TUE APR 14 2015
RADAR SHOWS HEAVIER SHOWERS LINING UP IN A BAND FROM RICHMOND
EAST-NORTHEAST THROUGH POWELL...MENIFEE...MORGAN AND ELLIOTT
COUNTIES. AN IFLOWS GAUGE NEAR SANDY HOOK JUST CLICKED OFF 0.52
INCHES OF RAIN IN THE PAST HOUR AND SUCH RATES WILL LIKELY
CONTINUE UNDER THIS BAND FOR SEVERAL HOURS. THIS BAND IS RIGHT
UNDERNEATH THE AXIS OF HIGHEST PWATS AND WILL NEED TO BE MONITORED
CLOSELY FOR FLOODING TO DEVELOP OVER THE NEXT FEW HOURS.
OTHERWISE...JUST PUSHED ALONG AN UPDATE TO ADD PATCHY FOG TO THE
FORECAST FOR THE REST OF THE NIGHT AND INCREASE SKY COVER AND
WINDS TODAY AND TONIGHT TO CORRESPOND WITH THE SCHEDULED AVIATION
UPDATE.
UPDATE ISSUED AT 1050 PM EDT MON APR 13 2015
2Z SPC MESOANALYSIS HAS PW VALUES ACROSS THE AREA RANGING FROM
AROUND 1.3 IN FAR SOUTHEASTERN PIKE COUNTY TO NEAR 1.6 INCHES IN
THE FAR SOUTHWEST. THIS PUTS THE WESTERN THIRD OF THE AREA AT
NEARLY 1.5 INCHES IN ADVANCE OF THE SLOW MOVING COLD FRONT.
RAINFALL RATES IN THE SHOWERS ACROSS THE WESTERN HALF OR SO OF THE
AREA HAVE PICKED UP A BIT OVER THE PAST HOUR WITH NEAR 0.02 INCHES
OVER THE PAST HOUR AT JKL. MANY OF THE KY MESONET SITES IN THE
WESTERN THIRD OF THE CWA NOW HAVE TOTALS SO FAR IN THE THIRD OF AN
INCH TO 0.45 INCH RANGE.
THE RECENT NEAR TERM MODEL GUIDANCE CONTINUES TO POINT TO THE
HIGHEST RAINFALL OVERNIGHT AND THROUGH MIDDAY ON TUESDAY GENERALLY
ALONG AND OR WEST OF A LINE FROM NEAR WILLIAMSBURG TO MANCHESTER
TO HAZARD TO INEZ. THERE IS SOME MODEL VARIABILITY FROM RUN TO RUN
OF THE HRRR AND RAP AS FAR AS AMOUNTS. THE 0Z NAM HAS THE HEAVIEST
QPF THROUGH 18Z ON TUESDAY...AND IS PROBABLY OVERDONE AT LEAST
WITH AREAL COVERAGE. HOWEVER...IT POINTS TO LOCALLY HIGHER
AMOUNTS EXCEEDING 3 INCHES NOT BEING OUT OF THE QUESTION.
ATTM...WE HAVE NUDGED THE AXIS OF THE HEAVIEST QPF A TAD FURTHER
TO THE NORTHWEST. OUR CURRENT FORECAST IS CLOSEST TO THE 01Z RAP.
UPDATE ISSUED AT 715 PM EDT MON APR 13 2015
RECENT SHORT TERM MODEL RUNS OF THE HRRR SUGGEST THE AXIS OF
HEAVIEST RAIN TONIGHT MAY BE GENERALLY ALONG AND NORTH OF A LINE
FROM WILLIAMSBURG TO LONDON TO JACKSON TO INEZ. THE 18Z NAM HAS
THE HEAVIEST RAINFALL THROUGH TOMORROW AFTERNOON WITH THE AXIS OF
THE HEAVIEST RAIN FURTHEST NORTHWEST. THE 18Z GFS IF GENERALLY THE
FURTHEST SOUTHEAST. THE HRRR RUNS CONTINUE TO BE IN THE MIDDLE OF
THESE TWO. THE 12Z ECMWF ALSO HAD THE HEAVIEST RAIN TONIGHT INTO
TUESDAY GENERALLY ALONG OR NORTHWEST OF THE LINE PREVIOUSLY
MENTIONED. THE 21Z AND 22Z RAP RUNS ARE A BIT FURTHER SOUTHEAST
COMPARED TO THE HRRR RUNS. ALTHOUGH THERE IS UNCERTAINTY...AT
THIS TIME RANGE...FEEL THE HIGHER RESOLUTION MODELS ARE LIKELY
ONTO A REAL TREND. WITH THIS IN MIND...THE QPF HAS BEEN TRENDED
SLIGHTLY TOWARD THE RECENT HRRR AND RAP RUNS WHICH SHIFTED THE
AXIS OF HEAVIER RAIN A TOUCH FURTHER WEST AND EXTENDED THIS AXIS
INTO NORTHEASTERN KY THROUGH MORGAN AND INTO ELLIOTT COUNTIES.
AS NEW MODEL RUNS ARRIVE...WE WILL CONTINUE TO EVALUATE THE
PLACEMENT OF THE AXIS OF HEAVIEST RAINFALL.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 335 PM EDT MON APR 13 2015
18Z SFC ANALYSIS SHOWS LOW PRESSURE MOVING CLOSER FROM THE
SOUTHWEST WHILE TO THE NORTH A COLD FRONT IS HEADING THIS WAY...AS
SEEN IN THE RADAR MOSAIC AND ON SATELLITE. JUST RECENTLY A FEW
SHOWERS HAVE POPPED UP OVER THE CUMBERLAND VALLEY AND ARE DRIFTING
NORTH NORTHEAST WHILE A MORE SUBSTANTIAL AREA OF RAIN IS LIFTING
NORTH OUT OF NORTHWEST AND NORTH CENTRAL TENNESSEE. FOR MUCH OF
THE DAY...THE CLOUDS STAYED MAINLY IN THE SOUTHERN PARTS OF THE
CWA ALLOWING THE MOSTLY SUNNY NORTH AND EASTERN PORTIONS TO WARM
INTO THE UPPER 70S AND LOWER 80S THIS AFTERNOON...IN CONTRAST TO
LOW AND MID 70S ATTAINED UNDER THE CLOUDS. DEWPOINTS HAVE COME UP
INTO THE LOWER AND MIDDLE 50S IN THE EAST AND NEAR 60 IN THE
WEST...WHILE WINDS HAVE BEEN SOUTH TO SOUTHWEST AT 10 TO 15 MPH.
THE MODELS ARE NOW IN PRETTY GOOD AGREEMENT ALOFT WITH THE
DYNAMIC SPLIT FLOW PATTERN IN PLACE. A DECENT TROUGH WILL MOVE
THROUGH THE GREAT LAKES IN THE NORTHERN STREAM WHILE A BROAD UPPER
LOW WILL SLIDE EAST THROUGH THE SOUTHERN PLAINS. PLENTY OF ENERGY
WILL SPREAD OVER KENTUCKY FROM THESE TWO SYSTEMS WITH THE SOUTHERN
STREAM ONE THE PRIMARY DRIVER FOR WEATHER THROUGH THE SHORT TERM.
THE NORTHERN TROUGH MOVES EAST BY TUESDAY MORNING AND A WELL
DEFINED MCV CROSSES FROM TENNESSEE INTO KENTUCKY THROUGH THE DAY
ACCOMPANIED BY SOME HEIGHT FALLS AND UPPER LEVEL DIVERGENCE. THE
BULK OF THE MID LEVEL ENERGY WILL LIFT NORTH OF THE STATE TUESDAY
NIGHT WHILE RIDGING HOLDS ON OVER THE SOUTHEAST. GIVEN THE MODEL
AGREEMENT HAVE GONE WITH A MODEL BLEND FOR THE WEATHER DETAILS...
WHILE ALSO LEANING HEAVILY ON THE HIGHER RESOLUTION NAM12 AND HRRR
GIVEN THE SMALL SCALE FEATURES THAT ARE CRITICAL TO THE FORECAST
TONIGHT INTO TUESDAY.
SENSIBLE WEATHER WILL FEATURE A RAPID INCREASE IN THE COVERAGE OF
SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND INTO THE
EVENING...OVER THE WESTERN PARTS OF THE AREA INITIALLY. BY
MIDNIGHT...THOUGH...EXPECT SHOWERS AND THUNDERSTORMS TO COVER MOST
OF THE CWA WITH AREAS OF TRAINING LIKELY SETTING UP. VERY HIGH PW
AIR WILL MOVE OVER EAST KENTUCKY TONIGHT IN CONJUNCTION WITH THE
APPROACH OF THE MCV AND COLD FRONT ADDING TO A THREAT OF EXCESSIVE
RAINS. FLASH FLOODING WILL BE POSSIBILITY FROM THIS...BUT GIVEN
THE DURATION OF THE RAINS...EXPECTED TO LAST INTO AT LEAST MIDDAY
TUESDAY...HAVE DECIDED TO GO WITH A BROADER FLOOD WATCH. THE
FRONT PRESSES FURTHER SOUTH AND THE SFC WAVE MOVES ON OUT OF THE
AREA TUESDAY AFTERNOON LEAVING BEHIND SOME LINGERING...LIGHTER...
SHOWERS ALONG WITH SIGNIFICANTLY COOLER TEMPERATURES THAN TODAY.
THE FRONT TO THE SOUTH WILL THEN START TO WORK BACK NORTH TUESDAY
NIGHT WITH INCREASING CHANCES OF SHOWERS BY DAWN WEDNESDAY.
USED THE SHORTBLEND AS A STARTING POINT FOR THE T/TD/WIND GRIDS
THROUGH THE NEXT 18 TO 24 HOURS WITH THE SUPERBLEND POPULATED FOR
THESE GRIDS THEREAFTER. DID MAKE SOME MINOR...TERRAIN BASED...
ADJUSTMENTS FOR TEMPERATURES EACH NIGHT. AS FOR POPS WENT WITH THE
HIGHER MAV MOS TONIGHT AND THEN A BLEND THROUGH THE REMAINDER OF
THE SHORT TERM PORTION OF THE FORECAST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 335 PM EDT MON APR 13 2015
LONG TERM PORTION OF THE FORECAST PRESENTS AN ACTIVE PATTERN
ACROSS EASTERN KENTUCKY. CLOSED LOW WILL ESTABLISH ITSELF MUCH OF
THE PERIOD BETWEEN THE SOUTHERN PLAINS TO THE FOUR CORNERS. THIS
WILL RESULT IN SEVERAL WAVES RIDING ALONG THE FLOW FROM SW TO NW.
THESE SUBTLE WAVES WILL PRESENT CHANCES OF SHOWERS AND SOME
THUNDERSTORMS THROUGH THE MUCH OF LONG TERM PERIOD. THIS PATTERN
DOES LOOK TO BREAKDOWN BASED OF THE GFS AS WE MOVE TOWARD THE END
OF THE WEEK INTO THE WEEKEND...AS A UPPER LEVEL LONG WAVE
TROUGH/CLOSED LOW PROGRESSES EAST OUT OF THE WESTERN US DEPENDING
ON WHICH RUN YOU LOOK AT. THIS HOWEVER...IS NOT SUPPORTED BY ALL
THE LONG RANGE GUIDANCE SUCH AS THE 00Z ECMWF...00Z GEM...00Z GFS
ENSEMBLE MEAN SOLUTIONS AT THIS POINT. THESE MODELS KEEP THE
CLOSED LOW ACROSS THE WESTERN US UNTIL WE MOVE INTO EARLY NEXT
WEEK. SHOULD BE SAID THAT BOTH SETUPS WOULD KEEP THE CHANCES OF
SHOWERS AND POSSIBLY THUNDERSTORMS IN THE FORECAST FROM TIME TO
TIME THROUGH MUCH OF THE PERIOD. THE REAL QUESTION IS HOW HIGH
WILL THE CHANCES BE ON A GIVEN DAY...THEREFORE RIGHT NOW WILL LEAN
CLOSE TO THE BLENDED GUIDANCE GIVEN THE UNCERTAINTY THAT EXISTS
WITH THE OVERALL PATTERN LATE IN THE LONG TERM PERIOD. THIS COULD
ALSO HAVE IMPLICATIONS ON TEMPERATURES ESPECIALLY TOWARD THE END
OF THE LONG TERM DEPENDING ON THE PROGRESSION OF THE UPPER LEVEL
PATTERN AND POTENTIAL FOR A COLD FRONT SWINGING THROUGH. AGAIN
THINK IT WILL BE BEST TO STAY CLOSER TO THE BLEND GIVEN THE MORE
UNCERTAIN PATTERN ALOFT. AFTER RELATIVELY COOLER...NEAR TO
SLIGHTLY BELOW NORMAL TEMPS FOR WEDNESDAY AND THURSDAY TEMPS FOR
MUCH OF THE PERIOD WILL BE IN THE LOWER 70S FOR MUCH OF EASTERN
KENTUCKY FOR HIGHS REMAINDER OF LONG TERM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 159 AM EDT TUE APR 14 2015
FLIGHT CONDITIONS ARE HIGHLY VARIABLE ACROSS THE AREA EARLY THIS
MORNING BUT EXPECT A GENERAL DECLINE IN CONDITIONS THROUGH DAWN AS
SHOWERS CONTINUE TO FEED NORTHWARD. TAFS SHOULD TREND TOWARD IFR
AT ALL LOCATIONS BY DAWN WITH ONLY A SMALL WINDOW OF IMPROVEMENT
TO MVFR DURING THE LATE AFTERNOON BEFORE DROPPING AGAIN TO THE IFR
LEVELS BY THE END OF THE PERIOD. WINDS WILL START OUT LIGHT BUT
INCREASE DURING THE DAY FROM THE NORTH-NORTHEAST AS AN AREA OF
LOW PRESSURE TRACKS INTO THE CUMBERLAND RIVER VALLEY. THESE HIGHER
WINDS WILL SUBSIDE AGAIN AFTER DARK.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH UNTIL 11 AM EDT THIS MORNING FOR KYZ044-050>052-
058>060-068-069-079-083.
FLOOD WATCH THROUGH THIS AFTERNOON FOR KYZ080-084>088-104-
106>120.
&&
$$
UPDATE...JP/ABE
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...ABE
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
411 AM CDT TUE APR 14 2015
.SHORT TERM...
IF YOU ARE LOOKING FOR A BREAK IN THE RAIN DO NOT HOLD YOUR
BREATH. THE NEXT ROUND OF SHOWERS AND THUNDERSTORMS ARE BEGINNINGTO
DEVELOP TO THE WEST JUST OUTSIDE OF OUR FORECAST AREA. EXPECT
SHOWERS AND THUNDERSTORMS TO CONTINUE TO DEVELOP THROUGH THE
MORNING HOURS AND MOVE OVER THE FORECAST AREA. WITH PRECIPITATBLE
WATER VALUES STILL WELL ABOVE NORMAL...DEEP ONSHORE FLOW AND THE
INSTABILITY FORECAST TO BE AROUND TODAY...EXPECT SHOWERS AND
STORMS TO BE VERY EFFICIENT RAINFALL PRODUCERS. THE STORM
PREDICTION CENTER HIGHLIGHTS PORTIONS OF OUR AREA IN A MARGINAL
RISK FOR SEVERE WEATHER TODAY BUT THE MAIN ISSUE WILL BE THE HEAVY
RAINFALL...THATS NOT TO SAY THAT ONE OR TO STORMS MAY BE STRONG OR
EVEN SEVERE. THE WEATHER PREDICTION CENTER HAS SOUTHEAST LOUISIANA
AND THE MISSISSIPPI GULF COAST IN A SLIGHT RISK FOR EXCESSIVE
RAINFALL. THIS MEANS THAT HEAVY RAINFALL CAN BE EXPECTED IN THE
AREA. AN ADDITIONAL 1 TO 3 INCHES OF RAINFALL IS POSSIBLE TODAY
OVER THE AREA ESPECIALLY IF YOU GET UNDER SOME OF THESE DEEPER
THUNDERSTORMS. HAVE NOT MADE ANY ADJUSTMENTS TO THE FLASH FLOOD
WATCH THE ONLY THING IS THAT IT MIGHT NEED TO BE EXTENDED BUT WILL
ALLOW DAY SHIFT TO SEE HOW CONVECTION EVOLVES TODAY AND WHERE THE
HEAVIEST RAINFALL OCCURS. HAVE NOT MADE MANY CHANGES IN THE SHORT
TERM. 13/MH
.LONG TERM...
THIS ACTIVE WET PATTERN CONTINUES IN THE LONG RANGE. EXPECT
ANOTHER ROUND OF RAIN FOR WEDNESDAY AND THURSDAY. MODELS INDICATE
A PRETTY WET FRIDAY AS WELL...IT IS POSSIBLE THAT THE FLASH FLOOD
WATCH THATS IN PLACE TODAY COULD BE IN PLACE THROUGH FRIDAY IF YOU
TAKE MODELS AT FACE VALUE. THERE WILL BE HIGH RAIN CHANCES THROUGH
AT LEAST SATURDAY. BOTH GFS AND ECMWF SHOW THE UPPER LEVEL
TROUGH/LOW FINALLY MOVING OUT LATE THIS WEEKEND...UNTIL THEN RAIN
WILL BE IN THE FORECAST. HAVE CONTINUED THE BLENDED APPROACH FROM
LAST PACKAGE. DIURNAL TEMPERATURE TRENDS TO CONTINUE WITH NOT MUCH MORE
THAN 10-15 DEGREE SPREAD. COULD SEE A LITTLE COOLER OVERNIGHT LOWS BEGINNING
SUNDAY IN THE NORTH IF SOME DRYING WORKS IN AFTER THE UPPER LOW
PULLS OUT ON SUNDAY INTO MONDAY. 13/MH
&&
.AVIATION...
THE TAFS ARE GOING TO BE HIGHLY DEPENDENT ON CONVECTIVE
COVERAGE AND TRENDS THROUGH AT LEAST 00Z. SOME EARLY DEVELOPMENTS
ALREADY IN PROXIMITY TO KHUM AND A LARGER CLUSTER OF SHOWERS
APPROACHING KBTR...LIKELY TO BRING VARABLE CIG HEIGHTS AND VSBY THIS
MORNING THOSE LOCATIONS. HRRR MODEL BLOSSOMS PRECIPITATION OVER MUCH
OF THE AREA TO IMPACT ALL TERMINALS PRIOR TO 18Z. 24/RR
&&
.MARINE...
A PROLONGED PERIOD OF ONSHORE FLOW IS EXPECTED TO PREVAIL THROUGH
THE WEEKEND...GENERALLY AT LIGHT TO MODERATE LEVELS. A LONG FETCHED
SITUATION FROM THE YUCATAN CHANNEL GENERATES A DEEP SWELL TRAIN ON
FRIDAY THAT SHOULD BRING SEAS CLOSE TO 6 FEET IN THE OPEN
WATERS...WITH SOME 8 FOOT RANDOM WAVES IN THE OUTER WATERS THAT MAY
REQUIRE A SMALL CRAFT ADVISORY AT SOME POINT FRIDAY INTO SATURDAY.
24/RR
&&
.DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE
ACTIVATION...NONE
ACTIVITIES...FLASH FLOOD WATCH.
MONITORING HEAVY RAINFALL/FLOODING POTENTIAL.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TONIGHT RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 77 65 77 66 / 80 40 60 40
BTR 77 66 79 67 / 80 40 60 40
ASD 78 67 79 68 / 80 40 60 40
MSY 78 68 79 69 / 80 40 60 40
GPT 77 69 77 70 / 70 40 60 40
PQL 79 68 79 69 / 70 40 60 50
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR LAZ040-046>050-
056>070-072.
GM...NONE.
MS...FLASH FLOOD WATCH THROUGH THIS EVENING FOR MSZ080>082.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
203 AM EDT TUE APR 14 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 400 PM EDT MON APR 13 2015
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
NW ONTARIO INTO THE WRN GREAT LAKES. STRONG QVECTOR DIV IN THE WAKE
OF A DEPARTING SHRTWV AND DROPPING 600-500 MB TEMPS HAVE RESULTED IN
A NEARLY DRY ADIABATIC PROFILE AND MIXING HEIGHT TO NEAR 15K FT WITH
GUSTY WNW WINDS ACROSS THE CWA. THE HIGH SFC-600MB LAPSE RATES HAVE
SUPPORTED THE DEVELOPMENT OF SOME ISOLD LIGHT SHOWERS SHOWERS OR
SPRINKLES/VIRGA FROM NW WI INTO SRN UPPER MI. DOWNDRAFTS ASSOCIATED
WITH THE LIGHT SHOWERS MAY ENHANCED THE GUSTY WINDS AS WAS OBSERVED
AT EGV WITH GUSTS TO 45 MPH.
TONIGHT...WITH THE LOSS OF DAYTIME HEATING AND A WEAKENING PRES
GRADIENT...THE GUSTY WINDS AND ISOLD PCPN WILL DIMINISH QUICKLY.
HOWEVER...FCST BOUNDARY LAYER WINDS SHOULD BE STILL STRONG ENOUGH TO
PROVIDE SOME MIXING AND KEEP TEMPS FROM DROPPING OFF TOO FAR WITH
MIN READINGS IN THE LOW TO MID 30S.
TUE...CONFLUENT MID/UPPER LEVEL FLOW AND THE SFC RIDGE WILL BUILD
OVER THE REGION BRINGING SUNNY SKIES AND DRY CONDITIONS. MIXING TO
AROUND 5K-6K FT OR 800 MB WILL SUPPORT HIGHS FROM THE UPPER 50S EAST
TO THE MID 60S SOUTH AND WEST. DEWPOINTS DROPPING INTO THE 10F-15F
RANGE WILL RESULT IN RH VALUES AROUND 15 PCT OVER THE CNTRL AND WEST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 353 PM EDT MON APR 13 2015
DRY CONDITIONS WILL CONTINUE FOR TUESDAY NIGHT THROUGH
WEDNESDAY...WITH A RIDGE OF HIGH PRESSURE BUILDING AT AT 500MB AND
LINGERING AT THE SFC. WITH PW VALUES AROUND 0.25IN OR LESS AROUND
DAYBREAK WEDNESDAY OVER THE E THIRD OF UPPER MI...FELT REASONABLE TO
LOWER THE MIN TEMPS FOR THE TRADITIONAL COLD SPOTS WEDNESDAY
MORNING TO RIGHT AROUND 30F.
THE APEX OF THE 500MB RIDGE WILL BE OVERHEAD WEDNESDAY
AFTERNOON...AHEAD OF A BROAD TROUGH NEARING FROM S CENTRAL CANADA.
DRY WEATHER WILL CONTINUE THE HIGHER FIRE WEATHER CONCERNS FOR FAR W
AND FAR S CENTRAL UPPER MI /S OF A LINE FROM IMT TO ISQ/. THIS WILL
BE WHERE RH VALUES IN THE UPPER TEENS COMBINE WITH TEMPS AROUND 15F
ABOVE NORMAL. ON A POSITIVE NOTE...WINDS WILL BE FAIRLY LIGHT S
CENTRAL. LOOKING AT THE FCST SOUNDINGS ANYTHING ABOVE 15KTS WOULD BE
ABOVE 400MB...OR AFTER 21Z CLOSER TO THE SFC. PW VALUES OVER THE E
HALF REMAIN AROUND 0.25IN OR LESS /DRIEST OF THE NAM SOLUTION/. OVER
THE FAR W...CLOSER TO THE NEARING LOW...S WINDS COULD GUSTS NEAR 15-
20KTS DURING THE MID TO LATE AFTERNOON HOURS.
AT THE SFC...LOOK FOR AN AREA OF LOW PRESSURE STRETCHING FROM THE S
SASKATCHEWAN/MANITOBA BORDER DOWN THROUGH E CO EARLY WEDNESDAY
MORNING TO DIVIDE INTO 2 SEPARATE SYSTEMS. THE S LOW WILL SINK INTO
TX WEDNESDAY/WEDNESDAY NIGHT WHILE THE N LOW HEADS NE INTO HUDSON
BAY THURSDAY MORNING. EXPECT THE STEADY STATE SFC RIDGE ACROSS UPPER
MI TO SLOWLY WEAKEN WEDNESDAY NIGHT/THURSDAY AS A RESULT OF THE
NEARING LOW. THE BROAD S CENTRAL CANADIAN TROUGH WILL MOVE OVER THE
UPPER GREAT LAKES FOR THE LATTER HALF OF THE WORK WEEK. THURSDAY
AFTERNOON WILL BRING A COLD FRONT STRETCHING FROM THE S HUDSON BAY
LOW THROUGH N MN. IT TENDS TO WASHOUT A BIT AS IT NEARS THE AREA.
WEDNESDAY NIGHT/THURSDAY MORNING WILL HAVE S-SSW WINDS JUST ABOVE
THE SFC /900-950MB/ OF 30-35KTS. SHOULD HAVE ENOUGH OF AN INVERSION
SET UP TO KEEP THESE WINDS FROM BEING REALIZED...WITH AROUND A 5-
10KT PUFF AT THE SFC.
THE 13/00Z RUN OF THE ECMWF IS MORE AGGRESSIVE/STRONGER WITH THE COLD
FRONT...WITH SIGHT SHOWERS THURSDAY MORNING AND W-NW WINDS SLIDING
IN LATE THURSDAY AFTERNOON/EVENING WITH 850MB TEMPS FALLING TO
AROUND 2C BY 06Z FRIDAY. BY CONTRAST THE 13/12Z GFS STILL HAS S FLOW
AND 850MB TEMPS AROUND 7C...AND REMAINS DRY. EXPECT HIGH CLOUDS
SLOWLY LOWERING THROUGH THE DAY...BUT AM NOT TOO EXCITED ABOUT ANY
CHANCE OF PRECIP IN OUR MAINLY DRY PATTERN. THE DIFFERENCES BETWEEN
THE GFS AND ECMWF CONTINUE TO WIDEN AS WE MOVE THROUGH THE WEEKEND.
THE NEXT FEATURE OF INTEREST LOOKS TO BE A SHORTWAVE NEARING IN THE
NW FLOW FROM S MANITOBA/NW MN FRIDAY AFTERNOON TO LAKE
SUPERIOR/UPPER MI FRIDAY EVENING. THE GFS IS STRONGER AND DEEPER
WITH THE SYSTEM...WITH A 996MB SFC LOW NEAR JAMES BAY BY 06Z
SATURDAY...AND PUMPS UP ADDITIONAL MOISTURE FROM THE 500MB LOW
EJECTING OUT OF THE SW STATES. THE ECMWF IS HOVERING AROUND
1007MB...TRACKING THE LOW OVER E LAKE SUPERIOR AND SE ONTARIO...AND
IS RUNNING INDEPENDENT OF THE S LOW SPINNING AROUND THE 4 CORNERS
REGION.
WITHOUT A LOT OF FANFARE...THE 13/00Z ECMWF MERGES THIS 4 CORNERS
LOW BACK INTO THE NEXT WAVE SINKING ACROSS MT AND THE PLAINS STATES
ON SUNDAY. THE RESULT WOULD BE PRECIP NEARING AGAIN FOR MONDAY ON E-
SE WINDS AND 850MB TEMPS AROUND 3C. THE 12Z RUN IS A LITTLE SLOWER
AND KEEPS PRECIP OUT OF THE CWA UNTIL MONDAY AFTERNOON W.
THE GFS KEEPS THE N AND S STREAMS A BIT MORE SEPARATED. AT 12Z
SUNDAY SFC LOWS OVER SW ONTARIO AND AR SLOWLY MERGE 12Z MONDAY
ACROSS LAKE HURON. PRECIP LOOKS TO SKIP UPPER MI UNTIL -10C AIR
PUSHES IN FROM THE NW ON MONDAY. SO THE MAIN QUESTION IS...WILL OUR
NEXT CHANCE OF ANY REAL PRECIP BE FRIDAY AFTERNOON/EVENING AS THE
GFS BELIEVES...OR WILL IT HOLD OFF UNTIL EARLY NEXT WEEK LIKE THE
ECMWF. WILL LOOK AT THE ENSEMBLE FCSTS...AND A GENERAL BLEND MAY BE
THE WAY TO GO FOR WEDNESDAY NIGHT THROUGH NEXT MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 201 AM EDT TUE APR 14 2015
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD AT ALL
SITES WITH QUIET WEATHER EXPECTED. SAW GETS A LAKE BREEZE TO MOVE
THROUGH BY MID AFTERNOON WHICH SHOULD SWITCH THEIR WIND TO THE
NORTHEAST UNTIL SUNSET WITH LIGHT WINDS THEREAFTER.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EDT MON APR 13 2015
AS THE PRES GRADIENT WEAKENS THIS EVENING...EXPECT THE GUSTY WRLY
WINDS OF 20 TO 30 KNOTS TO FALL BELOW 25 KNOTS. HIGH PRES BUILDING
OVER THE AREA LATE TONIGHT AND TUE WILL KEEP WINDS BLO 20 KNOTS.
WINDS ARE EXPECTED TO REMAIN AT OR BELOW 25 KNOTS THROUGH SATURDAY.
&&
.HYDROLOGY...
ISSUED AT 353 PM EDT MON APR 13 2015
WILL CONTINUE TO MONITOR MELTING SNOW AND RUNOFF FROM THE AVERAGE
0.25IN OF RAIN THAT FELL THIS MORNING. WHILE MOST LOCATIONS HAVE
ONLY PATCHES OF SNOW LEFT...A FEW SPOTS STILL HAVE SIGNIFICANT SNOW
/MOHAWK WITH 17IN AND MUNISING WITH 19IN/. THE FORECAST GETS A BIT
TRICKY FROM WEDNESDAY NIGHT ON...BUT UNTIL THEN NO ADDITIONAL PRECIP
IS EXPECTED.
DAY SHIFT ISSUED A HYDROLOGICAL STATEMENT /RVS/ FOR PRICKETT DAM ON
THE STURGEON RIVER...WHICH WAS AT 7.1FT AT 10AM MONDAY. FLOOD STAGE
IS 8 FT THERE.
ALONG WITH THE SURGEON RIVER OF BARAGA AND HOUGHTON COUNTIES...THE
ESCANABA RIVER WILL ALSO APPROACH BANKFULL STAGE IN SOME SPOTS MID-
WEEK...WHICH MAKES SENSE GIVEN THAT THE HEADWATERS OF THESE RIVER
HAVE THE MOST SNOW. THE MICHIGAMME RIVER ALSO HAS GREATER SNOWPACK
IN THE HEADWATERS REGION OF THE PESHEKEE RIVER...BUT IT SHOULD TAKE
LONGER FOR THAT WATER TO REACH LOWER SECTIONS OF THE RIVER MORE
PRONE TO FLOODING. STILL...NOT SEEING ANYTHING SUGGESTING MORE THAN
ACTION STAGE POSSIBLE ON THE MICHIGAMME RIVER. OVERALL...NOT
EXPECTING SIGNIFICANT FLOODING THROUGH THE WORK WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
HYDROLOGY...KF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
433 AM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL EXIT NORTHEAST PENNSYLVANIA AND SOUTHEAST NEW
YORK EARLY THIS MORNING TAKING THE SHOWERS WITH IT. AFTER THIS
FRONT PASSES BY, HIGH PRESSURE WILL PUSH DOWN FROM CANADA WITH
FAIR WEATHER AND SEASONAL TEMPERATURES FOR THE REST OF TODAY
THROUGH THURSDAY. THE NEXT CHANCE FOR RAIN SHOWERS WILL COME ON
THURSDAY NIGHT AS A WARM FRONT APPROACHES THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADARS SHOW A BAND OF SHOWERS OF RAIN FROM ABOUT UTICA TO
BINGHAMTON AND TOWANDA AT THIS TIME AND WORKING EAST AS THE UPPER
LEVEL WAVE MOVES INTO THE EASTERN GREAT LAKES. THIS WAVE HAS
PROVIDED THE IMPETUS TO PUSH A COLD FRONT INTO NY AND PA. HI RES
MODELS CONTINUE TO INDICATE THAT THIS BAND OF SHRA WILL CONTINUE
EASTWARD AND CLEAR THE POCONOS TO WRN CATSKILLS BY AROUND 12Z AS
THE UPPER WAVE AND COLD FRONT MOVE THRU. THERE WAS NO LIGHTNING
DETECTED AND SHOWALTER INDICES WERE ABOVE 0C SO NO THUNDER
IN GRIDS. THE HRRR IS QUICKEST IN MOVING PRECIP THRU NE PA/SERN NY
WITH THE HI RES ARW AND NMM HOLDING THE PRECIP BACK A COUPLE
HOURS LONGER. THE RAP REFLECTIVITY FIELDS SHOW THAT THE PRECIP
CLEARS THESE AREAS BY 12-13Z. SO I HAVE HELD ON TO SLGHT CHC AT
12Z IN THESE AREAS. REST OF FORECAST AREA WILL BE FREE OF PRECIP
BTWN 6Z AND 12Z.
AFTER THE PRECIP PASSES BY CLOUDS WILL CLEAR FOR A TIME THIS
MORNING. BUT COLD ADVECTION AT 850 MB AND SFC DEWPOINTS STILL IN
UPPER 30S SHUD LEAD TO SCT STRATOCUMULUS FORMING FOR A TIME BEFORE
ENUF DIURNAL MIXING TAKES PLACE BY MIDDAY TO MIX OUT THESE
CLOUDS. MODEL SOUNDINGS SUGGEST THIS AS WELL. THEN BY AFTERNOON
CIRRUS IN ADVANCE OF THE UPPER LEVEL LOW OVER TEXAS WILL ADVECT
NORTHEAST INTO THE UPPER CONFLUENT ZONE ALOFT WHICH CUTS ACRS
CENTRAL NY BY 18Z-21Z. SO WE EXPECT A SHIELD OF CIRRUS FROM SRN
NY ACROSS PA THIS AFTERNOON WHICH WILL BE THICK ENUF TO SPOIL A
MOSTLY SUNNY FORECAST. THESE CLOUDS WILL PUSH SOUTHEAST OF NE
PA/SERN NY THIS EVENING AS ANOTHER NRN BRANCH UPPER LEVEL SHORT
WAVE PUSHES SOUTHEAST FROM ONTARIO. SO... WE HAVE VARYING AMNTS
OF CLOUD COVER IN THE GRIDS FOR TODAY. NO POPS WARRANTING PRECIP
EXCEPT 12Z-14Z IN OUR FAR SE AND THESE ARE IN THE SLGHT CHC CAT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
AFTER CIRRUS SHIELD PUSHES SOUTHEAST OF NE PA AND SERN NY THIS
EVENING AN UPPER LEVEL WAVE WILL PUSH SOUTHEAST INTO NRN NEW
ENGLAND LATER TONIGHT AND WEDNESDAY WITH NY AND PA BEING ON THE
SUBSDC SIDE OF THIS TROUGH WITH THE UPPER RDG AXIS OVER THE ERN
LAKES. THIS WILL SUPPORT HIGH PRESSURE TO BUILD SOUTHWARD FROM
CANADA WITH A DRIER AIR AND SEASONAL TEMPS FOR TONIGHT...WED AND
WED NGT.
BY THURSDAY THE SFC HIGH SHIFTS OFF THE NEW ENGLAND COAST AND A
SRLY FLOW OF AIR WILL DEVELOP OVER NY AND PA WITH MID TO HI CLOUDS
SPREADING FROM SW TO NE ACRS C NY AND NE PA. LOOKING AT THE
SYNOPTIC MODELS IT LOOKS LIKE ANY PRECIP WILL HOLD OFF UNTIL AFTER
00Z FRI SO THU LOOKS DRY AND MILDER WITH SRLY WINDS.
FOR THURSDAY NIGHT...THE GFS...EURO...CMC AND UKMET ALL SHOW
DECENT LOW-LEVEL THETA-E ADVECTION ARND 850 MB WHICH WILL ALLOW
FOR DESTABLIZATION AND SHRA ACVTY TO WORK INTO NY AND NRN PA FROM
W TO E OVRNGT. IT LOOKS LIKE WRN AND CNTRL NY GET INTO SOME SHRA
ACVTY BTWN 00Z AND 06Z AND NE PA AND SERN NY AFTER 6Z SO HAVE
WORKED POP TIMING TO REFLECT THIS. SHOWALTER INDICES SUGGEST THE
AMS WILL BE STABLE ENUF SO NO MENTION OF THUNDER AT THIS POINT.
QPF AMNTS APPEARS TO BE ON THE ORDER OF ABT .25 INCHES WHICH WILL
NOT CAUSE ANY HYDRO ISSUES. THE NAM IS THE ODD MODEL OUT WITH MUCH
DRIER LL AIR TO START AND NOT ENUF MOISTURE ADVTN TO LEAD TO MUCH
PRECIP. SO WENT WITH GFS/EURO/CMC AND UKMET IDEAS AND HAVE CHC
POPS SHRA THU NGT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
LONGWAVE RIDGING IS FORECAST TO BUILD ACROSS THE EASTERN U.S.
EARLY IN THE LONG TERM PERIOD BEFORE THE PATTERN BECOMES A BIT
TRICKIER LATE IN THE PERIOD AS MODEL SOLUTIONS DIVERGE
SIGNIFICANTLY INTO NEXT WEEKEND.
QUIET WEATHER EXPECTED THUR INTO FRIDAY WITH NEAR TO SLIGHTLY ABOVE
NORMAL TEMPS. THE CHANCE OF SHOWERS INCREASES SAT INTO MONDAY AS
SHORTWAVE ENERGY ROUND THE UPPER RIDGE NEXT WEEKEND. THE EXTENT OF
LOWER HEIGHTS...WHICH WOULD SUPPORT A WETTER SOLUTION...IS IN
QUESTION...WITH THE GFS SYSTEM KEEPING A STRONGER RIDGE. THE ECMWF
BRINGS AN UPPER LOW EASTWARD OUT OF THE PLAINS INTO THE REGION.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
COLD FNT HAS MVD THRU THE NY STATIONS...APRCHG AVP ATTM. GNRL MVFR
CIGS WITH THE RAIN ASSOCITED WITH THE FNT. XPCT A 3 TO 4 HR PD OF
THE LWR CONDS AS THE FNT PASSES...WITH CONDS RETURNING TO VFR AT
NY STATIONS SHRTLY...CLSR TO 12Z AT AVP. REMAINDER OF THE TAF PD
WILL FEATURE VFR CONDS UNDER A HIGH CLD DECK...ALONG WITH LGT
WINDS.
.OUTLOOK...
TUE/WED/THUR...VFR.
THU NGT-SAT...POSSIBLE RESTRICTIONS IN -SHRA.
&&
.FIRE WEATHER...
DRIER AIR BEHIND A COLD FRONTAL PASSAGE WILL LEAD TO RELATIVE
HUMIDITIES FALLING BELOW 30 PERCENT THIS AFTERNOON. WINDS LOOK TO
BE LESS THAN 20 MPH ACROSS CENTRAL NEW YORK AND NORTHEAST
PENNSYLVANIA. IN ADDITION THE RAIN SHOWERS FROM LAST NIGHT AND
EARLY THIS MORNING SHOULD KEEP FINE FUELS ABOVE 10 PERCENT MOST OF
THE DAY. THEREFORE FIRE CONDITIONS ARE NOT EXPECTED TO APPROACH RED
FLAG CONDITIONS TODAY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...
AVIATION...DGM/HEDEN
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
415 AM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL EXIT NORTHEAST PENNSYLVANIA AND SOUTHEAST NEW
TORK EARLY THIS MORNING TAKING THE SHOWERS WITH IT. AFTER THIS
FRONT PASSES BY, HIGH PRESSURE WILL PUSH DOWN FROM CANADA WITH
FAIR WEATHER AND SEASONAL TEMPERATURES FOR THE REST OF TODAY
THROUGH THURSDAY. THE NEXT CHANCE FOR RAIN SHOWERS WILL COME ON
THURSDAY NIGHT AS A WARM FRONT APPROACHES THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADARS SHOW A BAND OF SHOWERS OF RAIN FROM ABOUT UTICA TO
BINGHAMTON AND TOWANDA AT THIS TIME AND WORKING EAST AS THE UPPER
LEVEL WAVE MOVES INTO THE EASTERN GREAT LAKES. THIS WAVE HAS
PROVIDED THE IMPETUS TO PUSH A COLD FRONT INTO NY AND PA. HI RES
MODELS CONTINUE TO INDICATE THAT THIS BAND OF SHRA WILL CONTINUE
EASTWARD AND CLEAR THE POCONOS TO WRN CATSKILLS BY AROUND 12Z AS
THE UPPER WAVE AND COLD FRONT MOVE THRU. THERE WAS NO LIGHTNING
DETECTED AND SHOWALTER INDICES WERE ABOVE 0C SO NO THUNDER
IN GRIDS. THE HRRR IS QUICKEST IN MOVING PRECIP THRU NE PA/SERN NY
WITH THE HI RES ARW AND NMM HOLDING THE PRECIP BACK A COUPLE
HOURS LONGER. THE RAP REFLECTIVITY FIELDS SHOW THAT THE PRECIP
CLEARS THESE AREAS BY 12-13Z. SO I HAVE HELD ON TO SLGHT CHC AT
12Z IN THESE AREAS. REST OF FORECAST AREA WILL BE FREE OF PRECIP
BTWN 6Z AND 12Z.
AFTER THE PRECIP PASSES BY CLOUDS WILL CLEAR FOR A TIME THIS
MORNING. BUT COLD ADVECTION AT 850 MB AND SFC DEWPOINTS STILL IN
UPPER 30S SHUD LEAD TO SCT STRATOCUMULUS FORMING FOR A TIME BEFORE
ENUF DIURNAL MIXING TAKES PLACE BY MIDDAY TO MIX OUT THESE
CLOUDS. MODEL SOUNDINGS SUGGEST THIS AS WELL. THEN BY AFTERNOON
CIRRUS IN ADVANCE OF THE UPPER LEVEL LOW OVER TEXAS WILL ADVECT
NORTHEAST INTO THE UPPER CONFLUENT ZONE ALOFT WHICH CUTS ACRS
CENTRAL NY BY 18Z-21Z. SO WE EXPECT A SHIELD OF CIRRUS FROM SRN
NY ACROSS PA THIS AFTERNOON WHICH WILL BE THICK ENUF TO SPOIL A
MOSTLY SUNNY FORECAST. THESE CLOUDS WILL PUSH SOUTHEAST OF NE
PA/SERN NY THIS EVENING AS ANOTHER NRN BRANCH UPPER LEVEL SHORT
WAVE PUSHES SOUTHEAST FROM ONTARIO. SO... WE HAVE VARYING AMNTS
OF CLOUD COVER IN THE GRIDS FOR TODAY. NO POPS WARRANTING PRECIP
EXCEPT 12Z-14Z IN OUR FAR SE AND THESE ARE IN THE SLGHT CHC CAT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
AFTER CIRRUS SHIELD PUSHES SOUTHEAST OF NE PA AND SERN NY THIS
EVENING AN UPPER LEVEL WAVE WILL PUSH SOUTHEAST INTO NRN NEW
ENGLAND LATER TONIGHT AND WEDNESDAY WITH NY AND PA BEING ON THE
SUBSDC SIDE OF THIS TROUGH WITH THE UPPER RDG AXIS OVER THE ERN
LAKES. THIS WILL SUPPORT HIGH PRESSURE TO BUILD SOUTHWARD FROM
CANADA WITH A DRIER AIR AND SEASONAL TEMPS FOR TONIGHT...WED AND
WED NGT.
BY THURSDAY THE SFC HIGH SHIFTS OFF THE NEW ENGLAND COAST AND A
SRLY FLOW OF AIR WILL DEVELOP OVER NY AND PA WITH MID TO HI CLOUDS
SPREADING FROM SW TO NE ACRS C NY AND NE PA. LOOKING AT THE
SYNOPTIC MODELS IT LOOKS LIKE ANY PRECIP WILL HOLD OFF UNTIL AFTER
00Z FRI SO THU LOOKS DRY AND MILDER WITH SRLY WINDS.
FOR THURSDAY NIGHT...THE GFS...EURO...CMC AND UKMET ALL SHOW
DECENT LOW-LEVEL THETA-E ADVECTION ARND 850 MB WHICH WILL ALLOW
FOR DESTABLIZATION AND SHRA ACVTY TO WORK INTO NY AND NRN PA FROM
W TO E OVRNGT. IT LOOKS LIKE WRN AND CNTRL NY GET INTO SOME SHRA
ACVTY BTWN 00Z AND 06Z AND NE PA AND SERN NY AFTER 6Z SO HAVE
WORKED POP TIMING TO REFLECT THIS. SHOWALTER INDICES SUGGEST THE
AMS WILL BE STABLE ENUF SO NO MENTION OF THUNDER AT THIS POINT.
QPF AMNTS APPEARS TO BE ON THE ORDER OF ABT .25 INCHES WHICH WILL
NOT CAUSE ANY HYDRO ISSUES. THE NAM IS THE ODD MODEL OUT WITH MUCH
DRIER LL AIR TO START AND NOT ENUF MOISTURE ADVTN TO LEAD TO MUCH
PRECIP. SO WENT WITH GFS/EURO/CMC AND UKMET IDEAS AND HAVE CHC
POPS SHRA THU NGT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
LONGWAVE RIDGING IS FORECAST TO BUILD ACROSS THE EASTERN U.S.
EARLY IN THE LONG TERM PERIOD BEFORE THE PATTERN BECOMES A BIT
TRICKIER LATE IN THE PERIOD AS MODEL SOLUTIONS DIVERGE
SIGNIFICANTLY INTO NEXT WEEKEND.
QUIET WEATHER EXPECTED THUR INTO FRIDAY WITH NEAR TO SLIGHTLY ABOVE
NORMAL TEMPS. THE CHANCE OF SHOWERS INCREASES SAT INTO MONDAY AS
SHORTWAVE ENERGY ROUND THE UPPER RIDGE NEXT WEEKEND. THE EXTENT OF
LOWER HEIGHTS...WHICH WOULD SUPPORT A WETTER SOLUTION...IS IN
QUESTION...WITH THE GFS SYSTEM KEEPING A STRONGER RIDGE. THE ECMWF
BRINGS AN UPPER LOW EASTWARD OUT OF THE PLAINS INTO THE REGION.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
COLD FNT HAS MVD THRU THE NY STATIONS...APRCHG AVP ATTM. GNRL MVFR
CIGS WITH THE RAIN ASSOCITED WITH THE FNT. XPCT A 3 TO 4 HR PD OF
THE LWR CONDS AS THE FNT PASSES...WITH CONDS RETURNING TO VFR AT
NY STATIONS SHRTLY...CLSR TO 12Z AT AVP. REMAINDER OF THE TAF PD
WILL FEATURE VFR CONDS UNDER A HIGH CLD DECK...ALONG WITH LGT
WINDS.
.OUTLOOK...
TUE/WED/THUR...VFR.
THU NGT-SAT...POSSIBLE RESTRICTIONS IN -SHRA.
&&
.FIRE WEATHER...
DRIER AIR BEHIND COLD FRONTAL PASSAGE WILL LEAD TO RELATIVE
HUMIDITIES FALLING BELOW 30 PERCENT THIS AFTERNOON. WINDS LOOK TO
BE BREEZY BUT MARGINAL. COORDINATED WITH SURROUNDING OFFICES WHO
MADE CONTACT WITH FORESTY OFFICIALS AND NO FIRE WEATHER HEADLINES
ARE NEEDED ATTM.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...
AVIATION...DGM/HEDEN
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
246 AM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL EXIT NORTHEAST PENNSYLVANIA AND SOUTHEAST NEW
TORK EARLY THIS MORNING TAKING THE SHOWERS WITH IT. AFTER THIS
FRONT PASSES BY, HIGH PRESSURE WILL PUSH DOWN FROM CANADA WITH
FAIR WEATHER AND SEASONAL TEMPERATURES FOR THE REST OF TODAY
THROUGH THURSDAY. THE NEXT CHANCE FOR RAIN SHOWERS WILL COME ON
THURSDAY NIGHT AS A WARM FRONT APPROACHES THE REGION.
&&
.NEAR TERM /THROUGH TODAY/...
RADARS SHOW A BAND OF SHOWERS OF RAIN FROM ABOUT UTICA TO
BINGHAMTON AND TOWANDA AT THIS TIME AND WORKING EAST AS THE UPPER
LEVEL WAVE MOVES INTO THE EASTERN GREAT LAKES. THIS WAVE HAS
PROVIDED THE IMPETUS TO PUSH A COLD FRONT INTO NY AND PA. HI RES
MODELS CONTINUE TO INDICATE THAT THIS BAND OF SHRA WILL CONTINUE
EASTWARD AND CLEAR THE POCONOS TO WRN CATSKILLS BY AROUND 12Z AS
THE UPPER WAVE AND COLD FRONT MOVE THRU. THERE WAS NO LIGHTNING
DETECTED AND SHOWALTER INDICES WERE ABOVE 0C SO NO THUNDER
IN GRIDS. THE HRRR IS QUICKEST IN MOVING PRECIP THRU NE PA/SERN NY
WITH THE HI RES ARW AND NMM HOLDING THE PRECIP BACK A COUPLE
HOURS LONGER. THE RAP REFLECTIVITY FIELDS SHOW THAT THE PRECIP
CLEARS THESE AREAS BY 12-13Z. SO I HAVE HELD ON TO SLGHT CHC AT
12Z IN THESE AREAS. REST OF FORECAST AREA WILL BE FREE OF PRECIP
BTWN 6Z AND 12Z.
AFTER THE PRECIP PASSES BY CLOUDS WILL CLEAR FOR A TIME THIS
MORNING. BUT COLD ADVECTION AT 850 MB AND SFC DEWPOINTS STILL IN
UPPER 30S SHUD LEAD TO SCT STRATOCUMULUS FORMING FOR A TIME BEFORE
ENUF DIURNAL MIXING TAKES PLACE BY MIDDAY TO MIX OUT THESE
CLOUDS. MODEL SOUNDINGS SUGGEST THIS AS WELL. THEN BY AFTERNOON
CIRRUS IN ADVANCE OF THE UPPER LEVEL LOW OVER TEXAS WILL ADVECT
NORTHEAST INTO THE UPPER CONFLUENT ZONE ALOFT WHICH CUTS ACRS
CENTRAL NY BY 18Z-21Z. SO WE EXPECT A SHIELD OF CIRRUS FROM SRN
NY ACROSS PA THIS AFTERNOON WHICH WILL BE THICK ENUF TO SPOIL A
MOSTLY SUNNY FORECAST. THESE CLOUDS WILL PUSH SOUTHEAST OF NE
PA/SERN NY THIS EVENING AS ANOTHER NRN BRANCH UPPER LEVEL SHORT
WAVE PUSHES SOUTHEAST FROM ONTARIO. SO... WE HAVE VARYING AMNTS
OF CLOUD COVER IN THE GRIDS FOR TODAY. NO POPS WARRANTING PRECIP
EXCEPT 12Z-14Z IN OUR FAR SE AND THESE ARE IN THE SLGHT CHC CAT.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AFTER FROPA ON TUESDAY...ASIDE FROM SOME ISOLATED SHRA LINGERING
IN THE POCONOS/WRN CATSKILLS BTWN 12Z AND 14Z REST OF C NY AND NE
PA WILL SEE NO PRECIP AS AGAIN MODEL CONSENSUS IS DRY. LOOKING AT
850 MB TEMPS AND SFC DEWPOINTS IT DOESN/T EVEN LOOK LIKE MUCH CU
FORMS TUE EXCEPT IN NC NY WHERE COLDER AIR AT 850 MB WILL BE
PRESENT TUESDAY. MUCH OF THE AREA TUESDAY WILL BE MOSTLY SUNNY AND
COOLER.
HIGH PRESSURE BUILDS IN FOR TUESDAY NIGHT AND LASTS THROUGH WED
AND WED NGT WITH FAIR WEATHER AND MODERATING TEMPERATURES WITH
MAXES REACHING INTO CLOSE TO OR ABOVE 60F EACH DAY.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
LONGWAVE RIDGING IS FORECAST TO BUILD ACROSS THE EASTERN U.S.
EARLY IN THE LONG TERM PERIOD BEFORE THE PATTERN BECOMES A BIT
TRICKIER LATE IN THE PERIOD AS MODEL SOLUTIONS DIVERGE
SIGNIFICANTLY INTO NEXT WEEKEND.
QUIET WEATHER EXPECTED THUR INTO FRIDAY WITH NEAR TO SLIGHTLY ABOVE
NORMAL TEMPS. THE CHANCE OF SHOWERS INCREASES SAT INTO MONDAY AS
SHORTWAVE ENERGY ROUND THE UPPER RIDGE NEXT WEEKEND. THE EXTENT OF
LOWER HEIGHTS...WHICH WOULD SUPPORT A WETTER SOLUTION...IS IN
QUESTION...WITH THE GFS SYSTEM KEEPING A STRONGER RIDGE. THE ECMWF
BRINGS AN UPPER LOW EASTWARD OUT OF THE PLAINS INTO THE REGION.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
COLD FNT HAS MVD THRU THE NY STATIONS...APRCHG AVP ATTM. GNRL MVFR
CIGS WITH THE RAIN ASSOCITED WITH THE FNT. XPCT A 3 TO 4 HR PD OF
THE LWR CONDS AS THE FNT PASSES...WITH CONDS RETURNING TO VFR AT
NY STATIONS SHRTLY...CLSR TO 12Z AT AVP. REMAINDER OF THE TAF PD
WILL FEATURE VFR CONDS UNDER A HIGH CLD DECK...ALONG WITH LGT
WINDS.
.OUTLOOK...
TUE/WED/THUR...VFR.
THU NGT-SAT...POSSIBLE RESTRICTIONS IN -SHRA.
&&
.FIRE WEATHER...
DRIER AIR BEHIND TONIGHTS COLD FRONTAL PASSAGE WILL LEAD TO
RELATIVE HUMIDITIES FALLING BELOW 30 PERCENT TUESDAY AFTERNOON.
WINDS LOOK TO BE BREEZY BUT MARGINAL. COORDINATED WITH SURROUNDING
OFFICES WHO MADE CONTACT WITH FORESTY OFFICIALS AND NO FIRE
WEATHER HEADLINES ARE NEEDED ATTM.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...
LONG TERM...
AVIATION...DGM/HEDEN
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
120 AM EDT TUE APR 14 2015
.SYNOPSIS...
A COASTAL TROUGH JUST OFF THE COAST WILL LIFT NORTHWARD OVERNIGHT.
A COLD FRONT WILL CROSS THE AREA EARLY WEDNESDAY MORNING...STALLING
TO OUR SOUTH ON THURSDAY. LOW PRESSURE MAY DEVELOP ALONG THE FRONT
THURSDAY INTO FRIDAY..LIFTING NORTH OF THE AREA SATURDAY. A COLD
FRONT WILL MOVE ACROSS THE CAROLINAS FROM THE WEST LATE SATURDAY.
HIGH PRESSURE WILL BUILD IN FROM THE WEST SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 130 AM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
SHOWERS HAVE BECOME QUITE FRAGMENTED ACROSS THE AREA...HOWEVER
THE ENVIRONMENT REMAINS CONDUCIVE FOR NEW SHOWERS TO DEVELOP AT
ALMOST ANY TIME...ESPECIALLY ACROSS THE CAPE FEAR AREA. FOR
WILMINGTON THE STRONGEST MAGNITUDE OF WARM ADVECTION SHOULD BE
OCCURRING IN THE NEXT FEW HOURS. SMALL BUT POSITIVE CONVECTIVE
INSTABILITY IS STILL PRESENT AS WELL...WITH KLTX RADAR SHOWING NEW
CELLS DEVELOPING VERY NEAR THE RADAR SITE IN BRUNSWICK COUNTY OVER
THE PAST HALF HOUR.
IT IS TOUGH TO SAY WHICH MODEL IS PERFORMING WELL. THE HRRR IS
MAINTAINING A VERY DRY FORECAST OVERNIGHT...BUT RADAR SUMMARIES
PLUS THE OVERALL SYNOPTIC SITUATION ARGUE OTHERWISE. I WILL
MAINTAIN FAIRLY HIGH POPS (60-70 PERCENT) IN THE WILMINGTON METRO
AREA...WITH LOWER POPS (30-50 PERCENT) ELSEWHERE FOR THE OVERNIGHT
PERIOD. NO CHANGES TO TEMPERATURES. DISCUSSION FROM 730 PM
FOLLOWS...
RADAR IMAGERY SHOWS A CLUSTER OF SHOWERS ASSOCIATED WITH SE
INFLOW OFF THE ATLANTIC ACROSS THE MYRTLE BEACH AREA...SPREADING
NORTH- NORTHWESTWARD. MODELS SUGGEST THESE SHOWERS ARE BEING
SUSTAINED BY TWO FACTORS: WEAK LIFT RESULTING FROM A SURGE OF WARM
ADVECTION BELOW 800 MB...COUPLED WITH AROUND 100 J/KG OF
CONVECTIVE INSTABILITY. A LESS ORGANIZED AREA OF SHOWERS ACROSS
CENTRAL SOUTH CAROLINA APPROACHING DARLINGTON AND FLORENCE
COUNTIES IS ROOTED HIGHER UP IN THE ATMOSPHERE WHERE WIND FLOW IS
SOUTHWESTERLY. THESE ARE MAINLY THE RESULT OF WEAK ISENTROPIC LIFT
ALONG THE 305K THETA SURFACE WHICH SHOULD ABATE BY MIDNIGHT.
MODELS ARE IN PRETTY GREAT DISAGREEMENT ABOUT PRECIPITATION
COVERAGE AND INTENSITY OVERNIGHT. THE 18Z NAM PROBABLY HAS THE
BEST HANDLE ON PRECIPITATION TRIGGERS I CAN ANALYZE. I ALSO LIKE
HOW THE 18Z NAM SEEMS TO BE ONE OF THE FEW MODELS TO SEE THAT
SURFACE WINDS ARE NOT VEERING WILDLY AROUND TO THE SE AT THE
COAST. (THE 22Z RAP PROBABLY HAS THE BEST HANDLE ON WINDS
CURRENTLY)
MY IDEA...BASED PRIMARILY ON THE NAM AND THE PREVIOUS FORECASTER`S
WORK...IS THAT THE BAND OF SUBSTANTIAL SHOWER ACTIVITY NEAR MYRTLE
BEACH WILL HAVE LIMITED SUCCESS WORKING INLAND...AND WILL INSTEAD
PREFERENTIALLY SHIFT NORTHWARD ALONG THE COAST AFFECTING
WILMINGTON AND THE CAPE FEAR AREA AFTER MIDNIGHT. THE ACTIVITY
ACROSS CENTRAL SC WILL MOVE NORTHEASTWARD DROPPING SPOTTIER
RAINFALL...AND DIMINISHING IN COVERAGE BY MIDNIGHT AS LIFT ALONG
THE 305K AND 310K ISENTROPIC SURFACES DIMINISHES.
PLENTY OF CLOUDS AND DEWPOINTS RISING INTO THE 60S WILL HOLD LOWS
IN THE MID 60S FOR MOST LOCATIONS...VIRTUALLY UNCHANGED FROM THE
PREVIOUS FORECAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY... FORECAST SOUNDINGS SHOW A DEEP LAYER OF
SATURATION FOR MUCH OF TUESDAY. AND WHILE THE ENTIRE DAY WILL NOT BE
A WASHOUT IT IS QUITE DIFFICULT TO HAVE ANY GIVEN HOUR WITH LOW POPS
DUE TO SEVERAL SMALL SCALE PERTURBATIONS MOVING THROUGH THE FLOW.
GIVEN WIDESPREAD CLOUD COVER MODELS HAVING DIFFICULTY DISCERNING HOW
MUCH INSTABILITY DEVELOPS. REGARDLESS THERE WILL BE ENOUGH FOR
ISOLATED THUNDER BUT BREAKS OR SUFFICIENT THINNING IN CLOUDS COULD
LEAD TO ENOUGH INSTABILITY SUCH THAT SPC HAS REFERENCED NC IN SWODY2.
CHANCE FOR ACTUAL SEVERE WEATHER TOO LOW FOR EVEN A `MARGINAL`
ISOPLETH IN THE OUTLOOK. GIVEN RELATIVELY LOW LCLS/MEAGER LAPSE
RATES FAVORING FAIRLY THIN BUT TALL CAPE AND THE LACK OF ANY DRY
AIR THE MAIN `THREAT` WILL BE NON-SEVERE (20-40MPH) WET
DOWNBURSTS. THE GFS DOES SHOW SOME DRYING AND THE DEVELOPMENT OF
DCAPE BY 00Z DUE TO THE EXIT OF DAY`S STRONGEST SHORTWAVE BUT MUCH
PAST PEAK HEATING THERE MAY NOT BE SUFFICIENT LIFT REMAINING FOR
DEEP CONVECTION. COLD FRONT PUSHES THROUGH DURING THE LATTER HALF
OF TUESDAY NIGHT ENDING MOST IF NOT ALL OF THE LIGHTNING AS LOW
LEVELS STRONGLY STABILIZE UNDERNEATH INVERSION AND LIFT REMAINS
TOO WEAK TO TAP ELEVATED INSTABILITY, IF ANY. LIGHT STRATIFORM
RAIN THEN STAYS IN THE FORECAST FOR MUCH OF WEDNESDAY AS THE
SURFACE WEDGE CONTINUES TO EXPERIENCE WEAK OVERRUNNING. HIGH TEMPS
FROM TUESDAY TO WEDNESDAY WILL GO FROM ROUGHLY 5 DEGREES ABOVE
CLIMO TO ROUGHLY 5 DEGREES BELOW. GIVEN THE STRENGTH OF THE WEDGE
WOULD NOT BE SURPRISED IF WEDNESDAY HIGHS NEED TO BE LOWERED A FEW
DEGREES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...MID LEVEL RIDGING OVER THE WESTERN ATLANTIC AND
GULF OF MEXICO ALONG WITH 5H TROUGHING/CUTOFF OVER THE SOUTHWEST
CONUS WILL SPREAD DEEP MOISTURE OVER THE SOUTHEAST INTO THE START OF
NEXT WEEK. IN ADDITION TO THE DEEP MOISTURE THE SOUTHWEST FLOW ALOFT
WILL ENSURE A STEADY SERIES OF SHORTWAVES EJECTING FROM THE 5H
CUTOFF PASS OVER THE REGION. THESE WAVES MAY WORK TO ENHANCE DIURNAL
CONVECTION...DEPENDING ON THEIR TIMING. TIMING THESE FEATURES IN THE
EXTENDED IS DIFFICULT AT BEST AND GIVEN THE UNCERTAINTY WITH RESPECT
TO AVAILABLE DIURNAL INSTABILITY AS WELL AS THE LOCATION OF ANY
LINGERING CONVECTIVE BOUNDARIES DO NOT PLAN ON ANY MAJOR CHANGES TO
POP FORECAST AT THIS TIME.
TEMPERATURES THU WILL BE NEAR TO BELOW CLIMO WITH HIGH PRESSURE
RIDGING DOWN THE COAST FROM THE NORTHEAST. THE PARENT HIGH MOVES OFF
THE NEW ENGLAND COAST BY FRI...BREAKING THE RIDGE AND ALLOWING
PASSAGE OF WEAK WARM FRONT/COASTAL TROUGH. THIS WILL USHER IN A
PERIOD OF HIGHS AND LOWS ABOVE TO WELL ABOVE CLIMO BUT IS ALSO
LIKELY TO KEEP PRECIP CHANCES ELEVATED THROUGH THE WEEKEND. CUTOFF
EMERGING FROM THE SOUTHWEST THIS WEEKEND WILL HELP DRAG A COLD FRONT
ACROSS THE AREA LATE IN THE PERIOD. STILL SOME UNCERTAINTY WITH
RESPECT TO TIMING BUT GFS IS A BIT FASTER...SUN NIGHT...WHILE THE
ECMWF IS SLOWER...LATER MON.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...ALL IN ALL...EXPECT DETERIORATING CONDITIONS ALL
TERMINALS TONIGHT WITH MVFR OR EVEN IFR CONDITIONS AT ALL
SITES...MAINLY DUE TO CIGS. ADDITIONALLY...SHOWERS ARE POSSIBLE
MUCH OF THE NIGHT...ESPECIALLY ALONG THE COAST. AFTER DAYBREAK
CONDITIONS SHOULD IMPROVE TO MVFR OR EVEN VFR ON S TO SW WINDS INVOF
10 KT BUT SHRA AND TSRA ARE POSSIBLE ALL TERMINALS FOR MUCH OF THE
DAY WITH MVFR OR TEMPO IFR POSSIBLE.
EXTENDED OUTLOOK...WED...A CHANCE OF MVFR IN THUNDERSTORMS.
MVFR/SHOWERS THURS THROUGH FRI. VFR SAT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
WIND SPEEDS NEARSHORE HAVE DIMINISHED OVER THE PAST FEW HOURS
WHILE WINDS OFFSHORE CONTINUE TO BLOW 15-20 KT ACCORDING TO THE
FRYING PAN SHOALS AND OFFSHORE WRIGHTSVILLE BEACH (41037) BUOYS.
THE COASTAL TROUGH IS TOUGH TO LOCATE BUT IS PROBABLY 5-10 MILES
OFFSHORE...AND SHOULD PUSH ACROSS OUR ENTIRE MARINE AREA IN THE
NEXT 3-5 HOURS. THIS WILL ALLOW WIND DIRECTIONS TO VEER EAST-
SOUTHEASTERLY ALL THE WAY UP TO THE BEACHES.
SHOWERS HAVE DIMINISHED OVERALL BUT THE ENVIRONMENT REMAINS
SUPPORTIVE OF NEW SHOWERS TO DEVELOP AT ANY TIME...MAINLY NORTH OF
MYRTLE BEACH ACROSS THE CAPE FEAR AREA WATERS. I AM MAINTAINING
HIGH CHANCES FOR SHOWERS IN THE FORECAST HERE. DISCUSSION FROM 730
PM FOLLOWS...
A COASTAL TROUGH IS HELPING TO KEEP WIND DIRECTIONS BACKED AROUND
TO THE EAST AND NORTHEAST ALONG THE COAST...WHILE FARTHER OFFSHORE
AT THE FRYING PAN SHOALS BUOY AND THE EDISTO BUOY WINDS HAVE
ALREADY SWUNG AROUND TO THE SOUTHEAST. THIS BOUNDARY SHOULD LIFT
NORTHWARD ALMOST LIKE A WEAK WARM FRONT TONIGHT...ALLOWING WINDS
EVEN AT THE BEACHES TO ASSUME A MORE SOUTHERLY DIRECTION BY
DAYBREAK TUESDAY.
AN AREA OF SUBSTANTIAL SHOWER ACTIVITY NEAR MYRTLE BEACH SHOULD
GRADUALLY LIFT NORTH ALONG THE COAST TONIGHT...REACHING CAPE FEAR
BY MIDNIGHT. SEAS CURRENTLY 3-5 FEET SHOULD MAINTAIN THEMSELVES
WITH A STEADY ONSHORE WIND EXPECTED TO CONTINUE.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY... SOUTH TO SOUTHWESTERLY FLOW ON TUESDAY IN A
PREFRONTAL FLOW REGIME AS BOUNDARY APPROACHES FROM THE NORTHWEST.
NEITHER WINDS NOR SEAS WILL BE PARTICULARLY STIRRED UP SO THE MAIN
THREAT TO MARINERS WILL BE THE FACT THAT SOME SHOWERS AND STORMS
COULD PRODUCE HEAVY ENOUGH RAINFALL FOR SOME VISIBILITY
RESTRICTIONS IN ADDITION TO SOME FAIRLY GUSTY (30-40KT) WINDS.
LATE NIGHT FROPA MAY CHANGE THAT HOWEVER AS A WEDGE OF HIGH
PRESSURE STARTS GETTING ESTABLISHED OVER LAND. AS THIS FEATURE
STRENGTHENS IN PART DUE TO RAIN FALLING INTO IT THE GRADIENT AND
RESULTING WIND/SEAS WILL RISE. AN ADVISORY WILL BE HOISTED AT SOME
POINT THOUGH ACTUAL ADVISORY CONDITIONS/6FT SEAS LIKELY NOT
MATERIALIZING TIL NIGHTTIME.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...PINCHED GRADIENT BETWEEN HIGH RIDGING IN FROM
THE NORTH AND COASTAL TROUGH WILL MAINTAIN NORTHEAST FLOW IN THE
20 TO 25 KT RANGE THU AND THU NIGHT. EXTENDED PERIOD OF INCREASED
NORTHEAST FLOW WILL KEEP SEAS OVER 6 FT ACROSS MUCH OF THE WATERS
AND HEADLINES ARE LIKELY TO BE CARRIED OVER FROM THE SHORT TERM
PERIOD. GRADIENT WEAKENS FRI AS THE HIGH SHIFTS EAST AS TROUGH
MOVES ONSHORE/LIFTS NORTH. AS THIS OCCURS WINDS WILL SHIFT FROM
NORTHEAST THU NIGHT TO EAST LATER FRI WITH SOUTHWEST FLOW
DEVELOPING LAT FRI NIGHT AND CONTINUING ON SAT. WEAKER GRADIENT
FRI AND SAT WILL KEEP SPEEDS GENERALLY 10 KT OR LESS WITH SEAS
DECREASING FROM 3 TO 5 FT FRI MORNING TO 2 TO 3 FT SAT AFTERNOON.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...REK/TRA
SHORT TERM...MBB
LONG TERM...III
AVIATION...RAN
MARINE...REK/TRA/MBB
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1253 AM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY AND MOVE
THROUGH EASTERN NC TUESDAY EVENING. THE FRONT WILL THEN BECOME
STATIONARY OVER THE SOUTHEAST STATES FOR SEVERAL DAYS. ANOTHER
COLD FRONT WILL MOVE THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL PASS
TO THE NORTH SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1245 AM TUESDAY...STILL ONLY SPOTTY RAIN ACROSS THE
REGION...BUT LATEST RADAR SHOWS INCREASING COVERAGE SOUTHEAST OF
WILMINGTON. LATEST 3KM HRRR SPREAD MORE PRECIPITATION INTO THE
COASTAL COUNTIES AFTER ABOUT 09Z OR 10Z. ADJUSTED POPS JUST A
BIT...BUT STILL FEEL LIKELY POPS ARE A GOOD BET BY THE EARLY
MORNING HOURS. ADJUSTED TEMPERATURES AND DEWPOINTS UP A BIT NEAR
THE COAST BASED ON LATEST OBSERVATIONS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
AS OF 3 PM MON...DEEP MOISTURE IN PLACE ALONG WITH LIFT PROVIDED
BY THE APPROACHING COLD FRONT WILL RESULT IN NUMEROUS SHOWERS.
CONTINUED LIKELY POPS WITH THUNDER POSSIBLE IN THE AFTERNOON.
GUIDANCE TEMPS LOOK TOO HIGH DUE TO SHOWERS AND OVERCAST SKIES.
HIGHS WILL RANGE IN THE LOWER TO MID 70S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
AS OF 230 PM MON...UNSETTLED THRU MUCH OF THIS PD WITH POSS OF
LOCALLY HEAVY RAIN HOWEVER CONFIDENCE QUITE LOW GIVEN POOR MODEL
AGREEMENT.
TUE NIGHT...COLD FRONT WILL SAG S THRU THE REGION WITH GOOD
COVERAGE OF SHRA EXPECTED...WILL CONT LIKELY POPS ALL AREAS IN
THE EVENING THEN CST LATE. MODELS A BIT WARMER THIS RUN AND
RAISED TEMPS TO MID 50S N AND AROUND 60 S.
WED AND WED NIGHT...A BIT DRIER THIS PERIOD ESPECIALLY NORTHERN
TIER...HOWEVER MODELS ARE TRENDING A BIT WETTER S AND INLAND.
HIGH PRES WILL BUILD IN FROM THE N WED AND BEGIN TO SHIFT OFFSHORE
WED NIGHT. DRIER AIR WILL TRY TO SPREAD IN FROM THE N
WED...HOWEVER MOISTURE WILL LINGER S AND W AND WITH WEAK IMPULSES
CROSSING A LOFT WILL CONT TO HAVE THREAT OF PRECIP. INCREASED POPS
TO CHC S AND SLIGHT CHC N WED AND WED NIGHT. HIGHS WED WILL BE IN
THE 60S WITH 50S WED NIGHT.
THU THROUGH THE SUNDAY...MOISTURE WILL INCREASE AGAIN THU WITH SCT
SHRA DEVELOPING AS LOW PRES FORMS TO THE S. THE LOW WILL LINGER
NEAR THE CST THROUGH FRIDAY WITH CONT THREAT OF SHRA...AGAIN
SIGNIFICANT MODELS DIFF SO LEANED TOWARD WPC SOLUTION THRU THIS
PERIOD WITH CHC POPS. A COLD FRONT WILL APPROACH FRI NIGHT AND
CROSS LATE SAT OR SAT NIGHT SCT SHRA. CONTINUED ISOLD TSRA FRI
AFTERNOON AND AGAIN SAT AS WEAK INSTABILITY DEVELOPS OVER REGION.
SHOULD FINALLY DRY OUT SUNDAY AS FRONT PUSHES WELL OFFSHORE.
HIGHS LOWER 70S INLAND THU THEN WARMING WELL INTO THE 70S REST OF
THE PERIOD..AS USUAL FOR THIS TIME OF YEAR BEACHES WILL BE A BIT
COOLER. LOWS 50S TO LOWER 60S.
MONDAY...DEEPER MOISTURE WILL RETURN AS HIGH SLIDES OFFSHORE AND
LOW PRESSURE APPROACHES FROM THE SW. HAVE CHC POPS WITH HIGHS IN
THE LOWER 70S INLAND TO 60S CST.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 06Z WEDNESDAY/...
AS OF 1250 AM TUESDAY...VFR CONDITIONS HOLDING TOUGH AS
PRECIPITATION SLOWLY MOVING INTO OUR REGION WITH ATMOSPHERE SLOWLY
BECOMING MORE SATURATED. EXPECT MVFR CEILINGS TO DEVELOP IN THE
NEXT FEW HOURS GIVEN UPSTREAM OBSERVATIONS. SOUTHEAST WINDS WILL
VEER SOUTH TONIGHT THEN BECOME SOUTHWEST TUESDAY.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM MON...REDUCED FLIGHT CATEGORIES WILL CONTINUE TUE
NIGHT ESPECIALLY AFTER COLD FRONT SAGS S WITH GOOD INVERSION
DEVELOPING. DRIER AIR WORKS IN WED AND SHOULD SLOWLY SEE LOW
CLOUDS SCOUR OUT HOWEVER SRN TIER MAY HOLD ON TO SOME SUB VFR
CONDITIONS. SCT SHRA EXPECTED TO DEVELOP THU AND CONT INTO FRI
WITH PERIODS OF SUB VFR LIKELY FROM TIME TO TIME. COLD FRONT WILL
APPROACH SAT WITH AGAIN SCT SHRA/POSS TSRA AND BRIEF PERIODS OF
SUB VFR EXPECTED.
&&
.MARINE...
SHORT TERM /THROUGH TUESDAY/
AS OF 1255 AM TUESDAY...LITTLE CHANGE TO CURRENT MARINE FORECAST.
WINDS CURRENTLY SOUTHEAST AT 10 KNOTS...EXCEPT AROUND 15 KNOTS
OVER THE CENTRAL WATERS. SEAS ARE GENERALLY 2 TO 4 FEET IN ALL
AREAS...WITH PERHAPS A FEW 5 FOOTS OVER THE OUTER EDGES OF THE
CENTRAL WATERS. WINDS BECOMING MORE SOUTHERLY AT 10 TO 15 KNOTS ON
TUESDAY WITH SEAS 3 TO 5 FEET.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... AS OF 230 PM
MON...S TO SW WINDS 10 TO 20 KTS TUE EVENING WILL GRAD SHIFT TO N
LATE AS COLD FRONT CROSSES. NNE WINDS WILL INCREASE TO 20 TO 25
KTS WED AS HIGH BUILDS IN FROM THE N... SCA LIKELY LATER TUE NIGHT
THROUGH WED AS SEAS BUILD TO 5 TO 8 FT. THE HIGH WILL SLIDE
OFFSHORE THU WITH WEAK LOW DEVELOPING TO THE S...WINDS WILL BECOME
EAST AND CONT GUSTY MAINLY 15 TO 25 KTS WITH SEAS REMAINING
ELEVATED AT 5 TO 9 FT. WEAK LOW WILL LINGER S OF REGION FRI WITH
SSE WINDS 10 TO 15 KT AND SEAS SUBSIDING TO 4 TO 6 FEET...HIGHEST
OUTER CENTRAL/SRN WATERS. COLD FRONT WILL APPROACH FROM THE W
LATER FRI NIGHT AND SAT WITH LIGHT WINDS FRI NIGHT BECOMING SSW
WINDS 10 TO 20 KTS SAT AHEAD OF THE FRONT..SEAS MAINLY 3 TO 5 FT
SAT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...HSA
NEAR TERM...CTC
SHORT TERM...HSA
LONG TERM...RF
AVIATION...RF/CTC/DAG
MARINE...RF/CTC
AREA FORECAST DISCUSSION
NWS MEDFORD OR
1042 PM PDT MON APR 13 2015
.UPDATED AVIATION DISCUSSION.
.DISCUSSION...A COLD FRONT IS MOVING THROUGH THE FORECAST
AREA...DROPPING TEMPERATURES BY 10 DEGREES IN LESS THAN AN HOUR AS
IT MOVES THROUGH. FEELING A SHARP TEMPERATURE CHANGE WITH A COLD
FRONT AS IT MOVES THROUGH IS NOT THAT COMMON IN THE VALLEYS OF
SOUTHERN OREGON OR NORTHERN CALIFORNIA...BUT TONIGHT`S FRONT WILL
DROP SNOW LEVELS SIGNIFICANTLY OVERNIGHT. BASED ON CURRENT
OBSERVATIONS AND THE NAM VERIFYING PRETTY WELL...HAVE BROUGHT
SNOW LEVELS DOWN TO NEAR 2000 FEET WEST OF THE CASCADES TONIGHT.
LATEST HRRR RUNS...IN COMBINATION WITH CURRENT SATELLITE
IMAGERY...ROAD SURFACE TEMPERATURES...AND METRO ROAD SURFACE
TEMPERATURE FORECASTS...SUGGEST THAT IMPACTS FROM THIS SNOWFALL
WILL BE MINIMAL. SOME SNOW WILL LIKELY FALL OVER SEXTON PASS AND
SISKIYOU SUMMIT ON INTERSTATE 5 THIS EVENING...BUT MOST SNOWFALL
SHOULD MELT ON THE ROADS AND LOWERED VISIBILITY SHOULD BE THE MOST
SIGNIFICANT IMPACT...SO DRIVERS SHOULD BE PREPARED AND OF COURSE
SLOW DOWN DURING ANY SNOW SHOWERS.
IN THE CASCADE PASSES...TEMPERATURES ARE JUST DROPPING TO FREEZING
AT DIAMOND LAKE WITH WET ROADS PER WEBCAMS. SIMILAR TO PREVIOUS
FORECAST THOUGHTS...LATEST MODELS SUGGEST A FEW INCHES OF
ACCUMULATION POSSIBLE AT AREAS LIKE DIAMOND LAKE...AND ROADS COULD
BECOME SLIPPERY LATER TONIGHT AS ROAD TEMPERATURES COOL TO NEAR
FREEZING. TRAVELERS SHOULD USE EXTRA CAUTION IF TRAVELING IN THE
CASCADES OVERNIGHT.
ADDITIONALLY...THE FRONT HAS BROUGHT GUSTY WINDS TO THE AREA...AND
HAVE ISSUED A WIND ADVISORY THROUGH THE EVENING FOR JACKSON COUNTY
WITH GUSTS TO 45 MPH.
LAST BUT NOT LEAST...GIVEN RECENT LIGHTNING STRIKES AND THE
PROGRESSION OF THE COLD POOL ALOFT...WE THINK OVERNIGHT THUNDERSTORMS
ARE POSSIBLE FROM GRANTS PASS NORTHWEST INTO JOSEPHINE...CURRY...COOS...AND
DOUGLAS COUNTIES.
SHOWERS ARE STILL POSSIBLE TOMORROW IN A WEAKLY UNSTABLE AIR MASS.
PLEASE SEE THE PREVIOUS DISCUSSION BELOW FOR DETAILS ON A RETURN
TO TO WARMER AND DRIER CONDITIONS LATER IN THE WEEK.
&&
.AVIATION...FOR THE 14/06Z TAF CYCLE...AN UNSTABLE AIR MASS WILL
MAINTAIN A MIX OF MVFR AND VFR CEILINGS IN SHOWERS OVERNIGHT.
THUNDERSTORMS ARE POSSIBLE LATE TONIGHT AND INTO THE EARLY MORNING
OVER PARTS OF COOS...CURRY...DOUGLAS...AND JOSEPHINE COUNTIES...WITH
THE BEST CHANCE AT THE IMMEDIATE COAST. THERE IS SOME UNCERTAINTY
WITH THE CLOUD DECKS TONIGHT WITH COLD SINKING AIR MOVING IN BEHIND
THE FRONT. MODELS AND OBSERVATIONS SUPPORT MAINTAINING MVFR
CONDITIONS FOR MUCH OF THE FORECAST AREA...SO HAVE KEPT THIS THEME
IN THE MOST RECENT TAFS.
MOUNTAIN OBSCURATION WILL AFFECT THE ENTIRE AREA THROUGH TUESDAY
MORNING...AND FREEZING LEVELS WILL CONTINUE TO FALL THROUGH THE
NIGHT. CONDITIONS SHOULD IMPROVE TO VFR AT MOST LOCATIONS BY LATE
TUESDAY MORNING OR EARLY AFTERNOON. SK
&&
.MARINE...UPDATED 900 PM PDT MONDAY APR 13 2015...WINDS HAVE
DECREASED TONIGHT TONIGHT...WELL BEHIND A COLD FRONT THAT MOVED
THROUGH EARLIER TODAY. THUNDERSTORMS ARE POSSIBLE THROUGH TUESDAY
MORNING AND STEEP SEAS AND SHOWERS WILL CONTINUE THROUGH TUESDAY. A
THERMAL TROUGH WILL DEVELOP WEDNESDAY AND THURSDAY WITH INCREASING
NORTH WINDS AND SEAS. THERE IS THE POTENTIAL FOR GALES SOUTH OF CAPE
BLANCO. THERE WAS SOME DISAGREEMENT WITH THE MODELS ON WINDS
WEDNESDAY EVENING SO STAYED AWAY FROM A GALE WATCH FOR WEDNESDAY
EVENING. THEN MODERATE WEST TO NORTHWEST SWELL WITH VERY LONG PERIOD
WILL ALSO ENTER THE REGION THURSDAY AND THEN LOWER ON FRIDAY. NORTH
WINDS MAY LOWER BRIEFLY ON FRIDAY BEFORE STRENGTHENING AGAIN THIS
WEEKEND. SK
&&
.PREV DISCUSSION... /ISSUED 522 PM PDT MON APR 13 2015/
SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT.
THE MAIN ITEMS OF INTEREST IN THE SHORT TERM ARE GUSTY WINDS
TONIGHT (STRONGEST ON THE EAST SIDE), RAIN AND SNOW WITH FALLING
SNOW LEVELS TONIGHT, A SLIGHT CHANCE OF COASTAL THUNDERSTORMS
LATE THIS EVENING INTO EARLY TUESDAY MORNING, SHOWERS AND SNOW
SHOWERS LATE TONIGHT INTO TUESDAY EVENING, AND COLD MORNING LOW
TEMPERATURES.
THERE WAS LITTLE ADJUSTMENT NEEDED TO THE FORECAST FOR TONIGHT.
A FAST MOVING COLD FRONT IS NOW REACHING THE COAST. WESTERLY
WINDS THIS AFTERNOON HAVE INCREASED TO RIGHT AROUND THE EXPECTED
STRENGTH. THE 12Z GFS MOS WIND SPEEDS WERE FORECAST TO BE SLIGHTLY
STRONGER THAN THE NAM MOS, AND ARE VERIFYING WELL AT THIS TIME
WITH WIDESPREAD REPORTS OF GUSTY, BREEZY 15 TO 25 MPH
WINDS...INCLUDING GUSTS OF 43 MPH AT SUMMER LAKE.
SNOW LEVELS WILL DROP QUICKLY FROM AROUND 6000 TO 7000 FEET THIS
AFTERNOON TO AROUND 2500 TO 3000 FEET BY THE TIME PRECIPITATION
TAPERS TO LIGHT SHOWERS LATE TONIGHT. THE BULK OF COASTAL RAIN
WILL FALL FROM NOW THROUGH THE EARLY EVENING, MAINLY AN EVENING
EVENT FOR THE WEST SIDE, AND A LATE NIGHT EVENT FOR THE EAST SIDE.
SNOWFALL OF 2 TO 5 INCHES IS EXPECTED AROUND CRATER LAKE WITH 1 TO
2 INCHES FOR MUCH OF THE CASCADES, AND GENERALLY LESS THAN AN INCH
OF SNOW ON THE EAST SIDE.
THE SLIGHT CHANCE OF COASTAL THUNDERSTORMS WILL ARISE FROM A
POST-FRONTAL SURFACE TROUGH THAT WILL HAVE ITS LANDFALL COINCIDE
WITH THE AXIS OF THE UPPER LEVEL TROUGH/COLDEST AIR ALOFT MOVING
INLAND. I MENTIONED IT IN YESTERDAY`S DISCUSSION AND IT BEARS
REPEATING THAT THE WEATHER ON TUESDAY WILL HAVE A RESEMBLANCE TO
WHAT OCCURRED ON SATURDAY. A COLD, WEAKLY UNSTABLE NORTHWEST FLOW
ALOFT WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS AND SNOW SHOWERS
THAT WILL FALL OUT OF LOW TOPPED CUMULUS CLOUDS. THE SNOW LEVEL ON
TUESDAY WILL RISE FROM AROUND 2500 FEET TO AROUND 3500 FEET WITH
AN ADDITIONAL INCH OF SNOW POSSIBLE IN THE CASCADES EXCEPT LIKELY
A BIT MORE (AROUND 2 INCHES) FOR CRATER LAKE.
VALLEY LOW CLOUDS AND PATCHY FOG ARE LIKELY TO HINDER COOLING
DURING EACH OF THE NEXT TWO NIGHTS, BUT IT WILL STILL BE QUITE
COLD ANYWAY WITH LOWS SEVERAL DEGREES BELOW NORMAL.
HIGH PRESSURE CENTERED OFFSHORE FROM CALIFORNIA WILL BUILD INTO
THE WEST COAST AND BRING A RETURN OF MOSTLY CLEAR TO CLEAR SKIES
WITH A WARMING TREND WEDNESDAY THROUGH THURSDAY.
LONG TERM...FRIDAY THROUGH MONDAY.
WARM AND DRY CONDITIONS WILL PERSIST THROUGH THE WEEKEND AS A
STRONG LONG WAVE RIDGE SETTLES JUST OFF THE WEST COAST WITH
NORTHERLY FLOW ALOFT AND LOW LEVEL OFFSHORE FLOW. A SHORT WAVE
TROUGH IS FORECAST TO MOVE ACROSS WASHINGTON AND NORTHERN OREGON
ON FRIDAY. THE MAIN EFFECT FROM THIS FEATURE IS TO PUSH HIGH
TEMPERATURES DOWN A FEW DEGREES ALTHOUGH IT WILL STILL BE ABOVE
SEASONAL NORMS. WE MAY ALSO SEE A SLIGHT INCREASE IN THE SURFACE
WESTERLY WINDS. THE GFS SHOWS SOME INSTABILITY IN TERMS OF THE
LIFTED INDEX BUT WESTERLY FLOW IS GENERALLY NOT FAVORABLE FOR
THUNDERSTORMS AND MOISTURE WILL BE VERY LIMITED.
ON SATURDAY THE LONG WAVE RIDGE REBUILDS WESTWARD TO AROUND
LONGITUDE 130W ALLOWING THE SHORT WAVE TROUGH TO DROP SOUTH ACROSS
OUR FORECAST AREA IN THE NORTH TO NORTHWEST FLOW ALOFT. THERE
SEEMS TO BE MORE INSTABILITY ACROSS OUR NORTHERN CALIFORNIA ZONE
SOUTHWARD. AT THIS POINT WE FEEL THAT THIS WOULD TRANSLATE INTO
MORE CUMULUS BUILDUPS OVER THE SISKIYOUS AND THE MARBLE MOUNTAINS
ON SATURDAY. THE RIDGE CONTINUES TO BUILD INTO THE WEST COAST
SUNDAY AND MONDAY. DURING THE PAST 10 RUNS THE GFS TREND HAS BEEN
TO FORECAST HIGHER 500 MB HEIGHT OVER THE PACIFIC NORTHWEST SO
CONFIDENCE IS HIGH THAT WE WILL SEE A WARM AND DRY TREND. HIGHS
IN THE ROGUE VALLEY ARE FORECAST TO BE IN THE LOWER 80S FROM
FRIDAY THROUGH MONDAY (WITH THE EXCEPTION OF SATURDAY DUE TO CLOUD
COVER). IF THIS SCENARIO HOLDS TRUE, THIS IS ALMOST 20 DEGREES
ABOVE SEASONAL NORMS FOR MID APRIL FOR THE ROGUE VALLEY AND ABOUT
15 DEGREES ABOVE NORMAL FOR AREAS EAST OF THE CASCADES. /FB
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY UNTIL 11 PM PDT THIS EVENING FOR ORZ026-620>623.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 8 PM PDT THIS EVENING FOR
PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT TUESDAY
FOR PZZ350-356.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT TUESDAY
FOR PZZ370-376.
$$
NSK/FJB/MAS
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1147 PM CDT Mon Apr 13 2015
.AVIATION...
/06Z TAFS/
MVFR ceilings have already spread south into the KABI (Abilene) and
KSJT (San Angelo) terminals late this evening, and should spread
south through the remainder of the sites during the early morning
hours. With a cool and moist air mass behind a cold front, these
low clouds should persist through the morning hours on Tuesday,
before lifting to VFR for the afternoon.
&&
.PREV DISCUSSION... /ISSUED 949 PM CDT Mon Apr 13 2015/
UPDATE...
The cold front has moved south to the I-10 corridor, masked
somewhat by convective outflow from this evening`s thunderstorms.
Winds have shifted to the northeast at 5 to 15 mph and will remain
so overnight. Dewpoints have already fallen into the 40s across
western north TX and this drier air will advect into the region
tonight, limiting the potential for additional measurable
precipitation. However, PoPs were maintained areawide given the
presence of the cold core of the upper cyclone moving slowly
across the CWA through early Tuesday. Rain chances were trimmed
back Tuesday, with most areas expected to remain dry. Expect high
temperatures in the upper 60s to lower 70s with northwest winds
around 10 mph.
The Flash Flood and Severe Thunderstorm Watches were dropped as
conditions are no longer favorable for significant convection.
Johnson
PREV DISCUSSION... /ISSUED 636 PM CDT Mon Apr 13 2015/
AVIATION...
/00Z TAFS/
Showers and thunderstorms will affect the KABI and KSJT terminals
this evening. The storms were developing along and behind a Cold
front that extended from just north of San Angelo and Brady. Winds
will shift to the north just after 00Z at KSJT and KBBD as the
front moves through. MVFR ceilings will develop a couple hours after
frontal passage. The front should move through KSOA and KJCT
around 4Z. MVFR ceilings should rise to IFR Tuesday noon over most
sites.
PREV DISCUSSION... /ISSUED 416 PM CDT Mon Apr 13 2015/
UPDATE...
Added a flash flood watch through 1 AM CDT for portions of the Big
Country...Concho Valley and Heartland until 1 AM CDT. Slow moving
thunderstorms along and north of a cold front will produce quick
heavy rainfall amounts of 1 to 3 inches...and may result in flash
flooding.
PREV DISCUSSION... /ISSUED 353 PM CDT Mon Apr 13 2015/
SHORT TERM...
(Tonight and Tuesday)
Scattered showers and thunderstorms were developing along and north
of a cold front from Mertzon to San Angelo to Brownwood at 3 PM.
SPC RAP analysis indicated SB CAPES around 1000 J/KG in this
area...which is a slight risk for severe thunderstorms this
afternoon and evening. The slight risk extends to the I-20 corridor.
While the severe threat is large hail and damaging winds are the
main threats, slow moving thunderstorms focused along the front will
also bring the potential for localized heavy rainfall and flash
flooding. If storm coverage becomes widespread, a flash flood watch
may be needed for Concho Valley to Brownwood and northward to the
I-20 corridor. With an upper low to the northwest in the South
Plains, there is also a low potential for a land spout or brief
tornado. The heavy rain and severe weather threat will diminish a
couple hours after sunset.
The front is indicated to move south to I-10 by midnight. Included a
slight chance of showers or thunderstorms for southern areas, but
severe weather threat is minimal as the front moves into more stable
air.
Keeping a slight chance of showers and thunderstorms, along and
northwest of a Sweetwater to Junction line...but most of the
moisture and instability will be southeast of West Central Texas.
LONG TERM...
(Tuesday night through next Monday)
Dry and warmer conditions are expected Wednesday, as south winds
develop. An upper low will drop southeast into the Central Rockies.
The 12Z GFS and ECMWF differ on the track of this low, and this will
have implications on our rain chances Thursday into the weekend. The
ECMWF is slower and takes the upper low south into New Mexico Friday
and Friday night, then eventually opens the low and tracks the wave
east into Oklahoma Saturday night and Sunday. The GFS has an
elongated trough extending south from the low, and has the low
dropping southeast into the Red River Valley Friday night into
Saturday.
With enough moisture return/availability indicated, we have chance
PoPs for showers and thunderstorms beginning Wednesday night in the
west, and continuing Thursday through late Saturday. A cold frontal
passage is anticipated Thursday night into Friday, but have
uncertainty on the timing with the aforementioned model differences.
Will have to monitor the forecast setup for the potential of strong
to severe storms.
The forecast looks dry Sunday into the first part of next week with
temperatures close to normal.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 50 64 50 82 62 / 40 20 10 10 20
San Angelo 52 70 52 84 62 / 20 10 10 10 20
Junction 55 73 54 84 63 / 20 20 10 10 20
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
342 AM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL SLIDE SOUTHEAST INTO THE AREA TODAY BEFORE
DROPPING SOUTH INTO THE CAROLINAS TONIGHT. A WEDGE OF HIGH
PRESSURE WILL BUILD IN BEHIND THE FRONT BY WEDNESDAY...AND LINGER
OVER THE REGION INTO AT LEAST FRIDAY. ANOTHER COLD FRONT WILL MOVE
ACROSS THE AREA OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM EDT TUESDAY...
FORECAST REMAINS QUITE COMPLICATED GIVEN THE SLOW MOVING COLD FRONT TO
THE WEST AND ASSOCIATED WEAK LOW PRESSURE THAT WILL SCOOT OUT OF THE TN
VALLEY AND INTO THE REGION LATER TODAY. THIS JUST AS THE FRONT FOLDS IN
FROM THE NORTH/NW ALLOWING LOW LEVEL CONVERGENCE TO MAXIMIZE THIS
MORNING INTO LATE AFTERNOON. MODELS HAVE AGAIN TRENDED FARTHER NORTH
WITH THE MAIN BAROCLINIC ZONE WHICH HAS SHIFTED THE AXIS OF BEST UPPER
DIFFLUENCE AND CORRESPONDING LIFT FARTHER NORTH/WEST. THIS WHILE
ALLOWING LESS UPSLOPE GIVEN VEERING FLOW FROM SOUTH/SE TO MORE SW AHEAD
OF THE BOUNDARY TODAY. CONSENSUS APPEARS FOR A STRIP OF HIGHER QPF FROM
SE WEST VA EAST INTO THE VA HIGHLANDS AND POINTS EAST WITH A SHARP
GRADIENT LIKELY NEAR HIGHWAY 460 AND POINTS SOUTH WHERE WILL SEE
MORE SCATTERED COVERAGE IN COMPARISON TO THE WIDESPREAD/HEAVIER
SHRA UP NORTH. HOWEVER WHERE TO DRAW THE LINE QUITE IFFY GIVEN
LIKELY TREND OF THINGS BEING OVERALL SLOWER PER THE WAVE TRACKING
NEAR TRI THIS AFTERNOON BEFORE SHUNTING EAST/SE. THIS MAY ALLOW
MUCH MORE OF A DIFFERENTIAL HEATING ZONE OVER THE SOUTH WHERE THE
LATEST NAM HAS CAPES NEAR 1K J/KG ALONG THE VA/NC BORDER PENDING
MORE BREAKS AND SUBSEQUENT HEATING. SPEED MAX TRACKING ACROSS LATE
MAY ALSO SPARK CLUSTERS OF TSRA THAT COULD LINE UP BEFORE SPILLING
SOUTH. THUS BEEFING UP THUNDER MENTION SOUTH AND INCLUDING IN THE
HWO PER DAY1 MARGINAL OUTLOOK.
OTRW HAVE ADJUSTED POPS DOWN SOME TO INIT EARLY ON...WITH HIGHER CAT
POPS NORTH/WEST FOR MUCH OF THE DAY...AND SLOWLY INCREASING FROM NORTH
TO SOUTH AS THE FRONT SAGS SOUTH AND THE WAVE HEADS EAST SIMILAR TO THE
NAM. FORECAST QPF OF 1-3 INCHES ESPCLY NW PROMPTS THE NEED TO EXTEND
THE FLOOD WATCH INTO THE VA HIGHLANDS GIVEN LOW FFG AND PERHAPS FARTHER
EAST LATER PENDING TRENDS. LONGER PERIOD OF WARM ADVECTION BEFORE THE
FLOW TURNS NE...AND POSSIBLY SOME SUN SOUTH SUGGESTS HIGHS WARMER
THAN PREVIOUS WITH MOST IN THE 60S TO LOWER 70S...AND SOME MID OR
EVEN UPPER 70S POSSIBLE FAR SOUTH IF THINGS BREAK OPEN MORE.
WAVE HEADS EAST THIS EVENING ALLOWING THE SURFACE FRONT TO BOW THROUGH
THE REGION FROM THE NORTH BRINGING THE ONSET OF THE LOW LEVEL WEDGE
FROM NE TO SW OVERNIGHT. THIS SHOULD TAKE THE DEFORMATION TYPE ZONE OF
HEAVIER SHRA TO THE EAST BY MIDNIGHT WITH RESIDUAL LEFTOVER MOISTURE
MAKING FOR CONTINUED SPOTTY -RA ESPCLY SW WHERE WILL SEE A WEAK
INVERTED TROUGH DEVELOP UNDER THE EASTERLY FLOW. THUS AFTER MOSTLY
LIKELY POPS DURING THE EARLY EVENING WILL SHIFT TO A MORE CHANCE REGIME
FOR -RA AND EVEN SOME SPOTTY -DZ AS THE NIGHT WEARS ON GIVEN THE
DECREASING DEPTH TO THE MOISTURE OFF FORECAST RAOBS LATE. KEPT TEMPS
SIMILAR TO THE SLIGHTLY WARMER MET MOS PER EXPECTED SLOWER TRENDS WITH
THE DEVELOPING CAD.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 315 AM EDT TUESDAY...
EXPECTING THAT CONVECTION WILL DRIVE SFC COLD FRONT SOUTH OF US
BY WEDNESDAY MORNING ACROSS THE CAROLINAS. MAIN SHORTWAVE AND
ASSOCIATED LOW PRESSURE ALONG THE FRONT WILL BE OFFSHORE IN THE
ATLANTIC OCEAN. IN SITU CAD EVENT WILL BECOME WELL ESTABLISHED ON
WEDNESDAY. WITH CLOUDS AND RAIN...LOWERED HIGH TEMPERATURES FOR
WEDNESDAY. HIGHS FOR WEDNESDAY WILL BE BELOW NORMAL WITH READINGS
FROM AROUND 50 DEGREES IN THE MOUNTAINS TO NEAR 60 DEGREES IN THE
PIEDMONT. IN GENERAL...LEANED POPS TOWARDS THE NAM FOR WEDNESDAY AND
SHAPED OUR QPF TOWARDS HPC.
CLOUDY WITH AREAS OF RAIN AND FOG ARE ANTICIPATED WEDNESDAY NIGHT
INTO THURSDAY. PLACED HIGH POPS ACROSS THE SOUTH WHERE WEDGE UPGLIDE
OVERLAPS WITH SOME UPPER DIVERGENCE. LOW TEMPERATURES WEDNESDAY
NIGHT WILL RANGE FROM THE UPPER 30S IN THE MOUNTAINS TO THE LOWER
40S IN THE PIEDMONT. UNDERCUT MOS HIGH TEMPERATURES FOR THURSDAY
WITH PLENTY OF CLOUDS AND AREAS OF RAIN AND FOG UNDER CAD. HIGHS
WILL VARY FROM THE UPPER 40S IN THE NORTHWEST TO THE MID 50S IN THE
SOUTHEAST. THE CLOUDY DREARY WEATHER CONTINUES THURSDAY NIGHT INTO
FRIDAY WITH LOW TEMPERATURES GENERALLY FROM THE LOWER 40S IN THE
NORTHWEST MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 215 PM EDT MONDAY...
NORTHERN STREAM TROF OVER THE NORTHEAST AMPLIFIES WITH A SURFACE
COLD FRONT COMING THROUGH THE REGION ON SATURDAY. MEANWHILE A LOW IS
CLOSED OFF OVER THE ROCKIES ON FRIDAY.
CLOSED LOW OVER THE ROCKIES OPENS UP AND ALSO TRACKS INTO THE UPPER
MISSISSIPPI VALLEY SATURDAY AND SUNDAY...WITH A PIECE OF THIS SYSTEM
REACHING THE FORECAST AREA ON MONDAY. SURFACE HIGH PRESSURE CROSSES
THE NORTHEAST UNITED STATES SUNDAY THEN BY MONDAY...ALREADY BACK IN
YET ANOTHER WEDGE WITH DEEP SOUTHEAST UPSLOPE FLOW WITH STRONG 850
WINDS.
WILL KEEP SATURDAY NIGHT THROUGH SUNDAY NIGHT DRY. WEDGE MAY BE SLOW
TO BREAK ON FRIDAY WHICH MAY LIMIT MAXIMUM TEMPERATURES. BUT
SATURDAY AHEAD OF THE FRONT WILL BE MILDER. TEMPERATURES BEHIND THE
FRONT ON SUNDAY WILL BE AROUND NORMAL.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
AS OF 1250 AM EDT TUESDAY...
CIGS GRADUALLY LOWERING TO MVFR FROM SW TO NE TONIGHT AS MOISTURE
INCREASES AHEAD OF THE FRONT TO THE WEST AND WEAK LOW PRESSURE
TRAVERSING THROUGH THE TN VALLEY. HOWEVER ONGOING RAINFALL REMAINS
LIMITED GIVEN BEST LIFT TO THE WEST WITH ONLY A SLOW INFLUX OF
STRATUS ONGOING MAINLY VIA SOUTH/SE UPSLOPE FLOW ACROSS THE WEST.
MODELS REMAIN TOO FAST IN LOWERING CIGS/VSBYS SO GIVEN CURRENT
TRENDS WILL BACK OFF ONSET OF IFR/LIFR CONDITIONS FOR A WHILE WITH
POTENTIAL FOR KLYH TO STAY VFR TO MVFR INTO TUESDAY MORNING.
ELSEWHERE WILL LOWER TO MVFR BEFORE DAYBREAK AND THEN DROP
NORTHERN/WESTERN LOCATIONS INTO IFR AS THE FRONT DIPS SOUTH BUT
LOW CONFIDENCE IN SEEING IFR CIGS PERSIST AT KDAN WHERE EXPECT MAY
MIX OUT THIS MORNING AND THEN LOWER IN DEVELOPING SHRA LATER ON.
ONCE THE FRONT BACKDOORS SOUTH INTO THE AREA TUESDAY WILL SEE
WINDS BECOME MORE EASTERLY FROM NORTH TO SOUTH DURING THE DAY BUT
MUCH SLOWER THAN EARLIER GIVEN THE FORECAST TRACK OF THE WAVE TO
BE FARTHER NORTH. THIS MAY AGAIN LIMIT THE SHOWER COVERAGE AT
KBCB/KROA/KDAN UNTIL LATER IN THE DAY WITH A SHARP GRADIENT
BETWEEN IFR/MVFR CIGS FROM KLWB TO KLYH AND PERHAPS MVFR TO VFR
FOR A WHILE BEFORE LOWERING TUESDAY AFTERNOON AS THE FRONT/WAVE
COMBO ACROSS THE REGION. FOR NOW WILL DELAY LOWER CIGS FURTHER
DURING TUESDAY BUT BRING ALL A PERIOD OF IFR DURING THE DAY WITH A
LONGER DURATION OF CONVECTIVE POTENTIAL ACROSS THE SOUTH AT KDAN.
WAVE SHUNTS TO THE SE TUESDAY NIGHT ALLOWING A DEEPENING WEDGE TO
TAKE SHAPE WITH WIDESPREAD IFR TO MVFR IN LINGERING LIGHT
RAIN/DRIZZLE FOG INTO THE OVERNIGHT.
EXTENDED AVIATION...
WEDNESDAY INTO THURSDAY...HIGH PRESSURE BEHIND THE FRONT WILL NOSE
SOUTH ALONG THE LEE OF THE APPALACHIANS...SETTING THE SCENE FOR A
COLD AIR DAMMING SCENARIO. AFTER A POTENTIAL BRIEF DECREASE IN
PRECIPITATION LATE TUESDAY NIGHT INTO EARLY WEDNESDAY...SOUTHEAST
FLOW WILL ALLOW FOR PRECIPITATION AND MORE IFR/MVFR CONDITIONS
ACROSS THE AREA...ESPECIALLY ACROSS THE SOUTHWEST PARTS OF THE
AREA.
THURSDAY NIGHT INTO FRIDAY...MODEL GUIDANCE DIFFERS ON THE
TIMING...BUT THE GENERAL TREND WILL BE ON THAT ALLOWS THE WEDGE TO
SLOWLY GIVES WAY TO INCREASING SOUTHWEST FLOW AHEAD OF A
SHORTWAVE TROUGH PROGRESSING INTO THE GREAT LAKES REGION...BUT NOT
COMPLETELY. THIS SHOULD ALLOW FOR SOME IMPROVEMENT TO FLIGHT
CATEGORIES...BUT SCATTERED SHOWERS AND THUNDERSTORMS WILL STILL BE
AN ISSUE.
THE AFOREMENTIONED SHORTWAVE TROUGH FRONT WILL BRING A COLD FRONT
THROUGH THE AREA ON SATURDAY. LOOK FOR MORE SUB-VFR
CONDITIONS...SHOWERS AND STORMS TO IMPACT THE AREA.
&&
.HYDROLOGY...
AS OF 330 AM EDT TUESDAY...
SHOWERS REMAIN SCATTERED ACROSS THE REGION EARLY THIS MORNING WITH
THE FRONT STILL WELL TO THE NW AND LOW PRESSURE OVER THE TN
VALLEY. LATEST HRRR SHOWS A SLOW FILLING IN OF PRECIP THROUGH THE
MORNING WITH THE MOST WIDESPREAD COVERAGE ESPCLY NORTHERN HALF
FROM MIDDAY THROUGH LATE AFTERNOON.
EXPECTED RAINFALL FOR MUCH OF THE FORECAST AREA WILL BE ONE TO TWO
INCHES EARLY WEDNESDAY. HOWEVER MODELS HAVE SHIFTED THE HEAVIER
AXIS OF PROJECTED RAINFALL NORTH ACROSS PARTS OF SOUTHEAST WEST
VIRGINIA INTO THE VIRGINIA HIGHLANDS WHERE POTENTIAL FOR TWO TO
THREE INCHES LOOKS POSSIBLE. GUIDANCE VALUES FOR RAINFALL IT WOULD
TAKE TO PRODUCE FLOODING ARE BELOW TWO INCHES FOR THE MOUNTAINS
AND ONLY AROUND AN INCH ACROSS THE VIRGINIA HIGHLANDS SO THE FLOOD
WATCH HAS BEEN EXTENDED TO COVER THOSE AREAS AS WELL. LIGHT TO
MODERATE RAIN WILL CONTINUE INTO THURSDAY ALONG THE BLUE RIDGE AND
IN THE FOOTHILLS IN FAR SOUTHWEST VIRGINIA INTO NORTHWEST NORTH
CAROLINA.
AT THIS TIME...THERE IS A LOW PROBABILITY OF MINOR MAINSTEM RIVER
FLOODING THROUGH THURSDAY. AREAL FLOODING OF SMALL STREAMS AND
CREEKS IS WHAT IS MORE LIKELY IF THE EXPECTED AMOUNT OF RAINFALL
OCCURS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ007-010-011-018>020.
FLOOD WATCH THROUGH THIS EVENING FOR VAZ009-012-013-015-016.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020.
WV...FLOOD WATCH THROUGH THIS EVENING FOR WVZ042>044-507-508.
&&
$$
SYNOPSIS...DS/JH
NEAR TERM...JH
SHORT TERM...KK
LONG TERM...AMS
AVIATION...DS/JH/MBS
HYDROLOGY...JH/AMS
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY
ISSUED AT 308 AM CDT TUE APR 14 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SPLIT FLOW
ACROSS NORTH AMERICA CONSISTING OF A RIDGE OVER THE ROCKIES...A
TROUGH OVER THE SOUTHERN PLAINS...AND CONVERGING UPPER FLOW ACROSS
THE EAST. THE WESTERN GREAT LAKES RESIDES DOWNSTREAM OF THE
RIDGE...WITH STRONG SUBSIDENCE LEADING TO CLEAR CONDITIONS ACROSS
THE REGION. THE AIRMASS ITSELF IS VERY DRY WITH PWATS FALLING BELOW
A QUARTER OF AN INCH. AS THE DRY SURFACE HIGH MOVES ACROSS THE
REGION...TEMPS AND HUMIDITIES ARE THE MAIN FORECAST CONCERNS THROUGH
WEDNESDAY.
TODAY...HIGH PRESSURE WILL DRIFT ACROSS THE REGION...WHICH WILL
PROMOTE CLEAR SKIES AND LIGHT WINDS. EVEN THOUGH UPSTREAM OBS SAW
DEWPOINTS CRASH INTO THE SINGLE DIGITS OVER MINNESOTA AND NORTH
DAKOTA IN THIS AIRMASS...SHOULD NOT HAVE THE KIND OF MECHANICAL
MIXING THIS REGION SAW YESTERDAY. HOWEVER...SHOULD SEE MIXING UP TO
800-750MB...WHICH SUPPORTS DROPPING DEWPOINTS INTO THE LOW TEENS UP
NORTH. COMBINED WITH HIGHS MAINLY IN THE MID TO UPPER 60S AWAY FROM
LAKE MICHIGAN...HUMIDITIES SHOULD FALL INTO THE TEENS. ELEVATED
FIRE WEATHER CONDITIONS WILL THEREFORE CONTINUE TODAY.
TONIGHT...HIGH PRESSURE WILL REMAIN PRESENT ACROSS THE REGION.
SHOULD SEE THIN CIRRUS INVADE FROM THE SOUTH AHEAD OF A WEAK UPPER
LOW ACROSS THE PLAINS. OTHERWISE QUIET...WITH LOWS FALLING INTO THE
UPPER 30S TO LOW 40S.
WEDNESDAY...CIRRUS WILL CONTINUE TO INVADE THE REGION AND BECOME
THICKER...WHICH WILL LEAD TO FILTERED SUNSHINE. THE SURFACE HIGH
WILL MOVE TO THE EASTERN GREAT LAKES...WHICH WILL CAUSE EAST TO
SOUTHEAST WINDS TO BECOME RELATIVELY STRONGER THAN TODAYS EXPECTED
SPEEDS. THE AIRMASS WILL MOISTURE SOME...BUT STILL WENT WITH THE
LOWEST GUIDANCE...WHICH PLACES RH VALUES BETWEEN 15 TO 25 PERCENT.
NO REPRIEVE FROM ELEVATED FIRE WEATHER CONDITIONS AS A RESULT.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
ISSUED AT 308 AM CDT TUE APR 14 2015
CONTINUED WARM AND DRY CONDITIONS WILL CONTINUE INTO THE
WEEKEND...WITH ONLY A SMALL CHANCE OF SHOWERS FRIDAY INTO FRIDAY
EVENING. A MORE POTENT SYSTEM IS EXPECTED TO AFFECT THE REGION
EARLY NEXT WEEK.
FOR WEDNESDAY NIGHT...AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE
REGION. MODEL SOUNDINGS WERE BONE DRY...THUS REMOVED ANY MENTION OF
RAIN DESPITE STEEP MID LEVEL LAPSE RATES WITH THIS SYSTEM. ON
THURSDAY...MODEL SOUNDINGS STILL SHOW VERY DRY SOUNDINGS ALTHOUGH
NOT AS DRY AS TUESDAY AND WEDNESDAY SOUNDINGS. DID LOWER DEW
POINTS BY 3 TO 5 DEGREES MOST PLACES AS A STARTING POINT. WEAK
BOUNDARY EXPECTED TO MOVE ACROSS THE REGION ON FRIDAY...BRINGING
A SMALL CHANCE OF SHOWERS. MODELS DO SHOW MORE MOISTURE WITH THIS
FEATURE TO SUPPORT THE SMALL CHANCE OF SHOWERS.
HIGH PRESSURE WILL BUILD INTO THE REGION ON SATURDAY AND CONTINUE
INTO SUNDAY. VERY DRY CONDITIONS ARE EXPECTED AGAIN SATURDAY WITH
VERY LOW AFTERNOON RELATIVE HUMIDITY READINGS. ATTENTION THEN TURNS
TO UPPER LOW ACROSS THE CENTRAL UNITED STATES WILL INTERACT WITH
500MB TROUGH MOVING ACROSS SOUTHERN CANADA. THIS FEATURE SHOULD
ALLOW FOR LOW PRESSURE TO FORM AND BRING A CHANCE OF RAIN TO THE
AREA SUNDAY NIGHT AND MONDAY.
DID LOWER MIN TEMPERATURES WEDNESDAY NIGHT AND THURSDAY NIGHT...
WHILE RAISING MAX TEMPERATURES A DEGREE OR TWO ON MOST DAYS INTO
THE WEEKEND.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1044 PM CDT MON APR 13 2015
PATCHY MID LEVEL CLOUDS WILL DEPART NORTHERN WISCONSIN OVERNIGHT
OTHERWISE VFR CONDITIONS TO PREVAIL OVERNIGHT INTO TUESDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......TDH
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
418 AM MST TUE APR 14 2015
.UPDATE...UPDATED AVIATION...FIRE WEATHER...AND WWA SECTIONS...
&&
.SYNOPSIS...
THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS OVER
PORTIONS OF SOUTH-CENTRAL ARIZONA TODAY BUT WITH LITTLE IF ANY
RAINFALL. OTHERWISE EXPECT ANOTHER WARM DAY. A DRY COLD FRONT PUSHES
THROUGH SOUTHEAST CALIFORNIA AND ARIZONA TUESDAY NIGHT AND
WEDNESDAY. THIS WILL LEAD TO VERY WINDY CONDITIONS OVER SOUTHEAST
CALIFORNIA AND WESTERN ARIZONA. WINDS WILL NOT BE QUITE AS STRONG
OVER SOUTH-CENTRAL ARIZONA. THE FRONTAL PASSAGE WILL ALSO LEAD TO
MUCH COOLER TEMPERATURES...DIPPING BELOW THE NORMAL BY THURSDAY.
EXPECT A WARMING TREND FRIDAY THROUGH SUNDAY WITH LITTLE CHANGE
MONDAY.
&&
.DISCUSSION...
TODAY...ISOLATED THUNDERSTORMS MONDAY EVENING OVER SOUTHEAST ARIZONA
REFLECTED THE PRESENCE OF JUST ENOUGH MOISTURE AND
INSTABILITY...ALONG WITH A SUBTLE PERTURBATION...TO GET THUNDERSTORMS
TO FORM. THIS WILL BE THE CASE AGAIN LATER TODAY...ESPECIALLY AS
SOUTHEAST AND SOUTHERLY LOWER LEVEL WINDS PROVIDE FOR SOME MOIST
ADVECTION AS EVIDENT IN MODEL SOUNDINGS. FOR TODAY THE PERTURBATION
WILL NOT BE ASSOCIATED WITH THE UPPER LOW TO OUR EAST BUT INSTEAD A
SHORT WAVE AHEAD OF THE PACIFIC LOW PRESSURE SYSTEM ALREADY MOVING
ASHORE EARLY THIS MORNING OVER NORTHERN CALIFORNIA AND THE PACIFIC
NORTHWEST. NAM BOUNDARY LAYER CAPE IS MODEST BUT MORE WIDESPREAD FOR
LATE THIS AFTERNOON THAN IT WAS FOR YESTERDAY. HRRR HAS HAD SEVERAL
RUNS DEPICTING ISOLATED-SCATTERED CONVECTION OVER CENTRAL AND EASTERN
ARIZONA THIS AFTERNOON THOUGH IT APPEARS TO BE THE MOST AGGRESSIVE OF
THE HI-RES MODELS...ESPECIALLY COMPARED TO LOCAL WRF. LATEST SSEO
HINTS AT CONVECTION AFFECTING OUR EASTERN AREAS. SPC HAS GENERAL
THUNDER OVER THE EASTERN THIRD OF ARIZONA. GIVEN ALL THIS...ADDED A
SLIGHT CHANCE OF THUNDERSTORMS THIS AFTERNOON AND EVENING OVER OUR
PORTIONS OF PINAL AND GILA COUNTIES. ALSO ADDED A MENTION OF PATCHY
BLOWING DUST FOR OUR PORTION OF PINAL COUNTY AS THUNDERSTORMS...IF
ANY...WILL BE ABLE TO PRODUCE SOME NOTABLE OUTFLOW GIVEN INVERTED V
SOUNDINGS.
TONIGHT THROUGH THURSDAY...THE BRUNT OF THE AFOREMENTIONED PACIFIC
LOW PRESSURE SYSTEM WILL INITIALLY AFFECT AREAS WELL NORTH OF OUR
FORECAST AREA. HOWEVER...THERE WILL BE A DRY COLD FRONT THAT PUSHES
THROUGH SOUTHEAST CALIFORNIA AND ARIZONA BEGINNING TUESDAY NIGHT AND
CONTINUING WEDNESDAY. VERY STRONG NORTHERLY WINDS IN THE LOWER
LEVELS WILL BE ASSOCIATED WITH THE FRONTAL PASSAGE...MOST NOTABLY
FOR WESTERN PORTIONS OF OUR FORECAST AREA IN SOUTHEAST CALIFORNIA
AND SOUTHWEST ARIZONA. THUS A WIND ADVISORY IS IN EFFECT FOR THOSE
AREAS. AREAS OF BLOWING DUST/SAND WILL BE POSSIBLE AS WELL. VERY DRY
AIR WILL ALSO BE USHERED IN AND THE FIRE WEATHER WATCH WAS UPGRADED
TO A RED FLAG WARNING. SEE W/W/A SECTION BELOW FOR TIMING AND
AFFECTED ZONES. THE MODELS DEPICT THE UPPER TROUGH...INITIALLY
CENTERED WELL TO OUR NORTH...TRACKING SOUTHEASTWARD AND BECOMING A
CLOSED LOW OVER THE SOUTHERN ROCKIES/FOUR CORNERS AREA. THE GFS
CONTINUES TO HAVE IT CENTERED NORTHEAST OF THE ECMWF SOLUTION.
LATEST GEM IS MORE CLOSELY ALIGNED WITH ECMWF. THOSE MODELS ARE
GENERALLY SUPPORTED BY THEIR RESPECTIVE ENSEMBLE MEANS. THE ECMWF
AND GEM SOLUTIONS HAVING THE COLD CORE CLOSER TO OUR FORECAST AREA.
MEANWHILE...VORT LOBES/JET STREAKS ROTATE AROUND THE LOW.
HOWEVER...MOISTURE AVAILABILITY OVER OUR FORECAST AREA WILL BE QUITE
MEAGER SO HELD OFF ON INTRODUCING POPS. THERE WILL BE AT LEAST
LINGERING BREEZINESS...WINDY CONDITIONS WEDNESDAY NIGHT WITH ONE OF
THOSE VORT LOBES PUSHING THROUGH. BIGGEST BENEFIT OF THIS SYSTEM WILL
BE MUCH COOLER TEMPERATURES WEDNESDAY AND THURSDAY...AT LEAST A FEW
DEGREES BELOW NORMAL BY THURSDAY.
FRIDAY THROUGH MONDAY... THE LOW SLOWLY MOVES EASTWARD FRIDAY
THROUGH SUNDAY AND HEIGHTS/THICKNESSES REBOUND. ACCORDINGLY...A
WARMING TREND BEGINS FRIDAY WITH HIGHS BACK TO THE LOW 90S ON THE
LOWER ELEVATIONS BY SUNDAY. WEAK UNDERCUTTING OF THE RIDGE OVER THE
WEST EARLY NEXT WEEK KEEPS TEMPS FLAT.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CERTAINLY LOOKING AT A QUIET WEATHER DAY ACROSS SOUTHEAST CALIFORNIA
ALTHOUGH WINDS WILL PICK UP EARLY WEDNESDAY MORNING. MEANWHILE AROUND
PHOENIX WINDS WILL FOLLOW TYPICAL DIURNAL TRENDS WITH MOSTLY CLEAR
SKIES. COULD BE SOME DISTANT CU TO THE SOUTH/EAST OF
PHOENIX...POSSIBLY SOME VIRGA AND/OR ISOLATED SHOWERS AS WELL.
SHOULD NOT IMPACT THE TERMINALS DIRECTLY BUT GIVEN THE VERY DRY SUB-
CLOUD LAYER...WILL NEED TO MONITOR ANY SHOWERS FOR BLDU.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
AN AREA OF LOW PRESSURE WILL CONTINUE TO MOVE THROUGH THE FOUR
CORNERS REGION THURSDAY AND FRIDAY. HOWEVER...DRY AIR WILL REMAIN
IN PLACE INTO THE WEEKEND...AND WITH VERY LITTLE ATMOSPHERIC
MOISTURE...THERE WILL BE NO PRECIPITATION...JUST SOME PASSING HIGH
CLOUDS. WINDS WILL BE MUCH LIGHTER THROUGH FRIDAY INTO THE WEEKEND.
EXPECT FAIR/POOR OVERNIGHT RECOVERIES DURING THE PERIOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...RED FLAG WARNING FROM 5 AM TO 9 PM MST WEDNESDAY FOR AZZ131-132.
WIND ADVISORY FROM 2 AM TO 9 PM MST WEDNESDAY FOR AZZ020-021-025-
026.
CA...RED FLAG WARNING FROM 5 AM TO 9 PM PDT WEDNESDAY FOR CAZ231.
WIND ADVISORY FROM 2 AM TO 9 PM PDT WEDNESDAY FOR CAZ030>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
AVIATION...LEINS
FIRE WEATHER...LEINS/MEYERS
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
410 AM MST MON APR 13 2015
.SYNOPSIS... THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS OVER
PORTIONS OF SOUTH-CENTRAL ARIZONA TODAY BUT WITH LITTLE IF ANY
RAINFALL. OTHERWISE EXPECT ANOTHER WARM DAY. A DRY COLD FRONT PUSHES
THROUGH SOUTHEAST CALIFORNIA AND ARIZONA TUESDAY NIGHT AND
WEDNESDAY. THIS WILL LEAD TO VERY WINDY CONDITIONS OVER SOUTHEAST
CALIFORNIA AND WESTERN ARIZONA. WINDS WILL NOT BE QUITE AS STRONG
OVER SOUTH-CENTRAL ARIZONA. THE FRONTAL PASSAGE WILL ALSO LEAD TO
MUCH COOLER TEMPERATURES...DIPPING BELOW THE NORMAL BY THURSDAY.
EXPECT A WARMING TREND FRIDAY THROUGH SUNDAY WITH LITTLE CHANGE
MONDAY.
&&
.DISCUSSION...
TODAY...ISOLATED THUNDERSTORMS MONDAY EVENING OVER SOUTHEAST ARIZONA
REFLECTED THE PRESENCE OF JUST ENOUGH MOISTURE AND
INSTABILITY...ALONG WITH A SUBTLE PERTURBATION...TO GET
THUNDERSTORMS TO FORM. THIS WILL BE THE CASE AGAIN LATER
TODAY...ESPECIALLY AS SOUTHEAST AND SOUTHERLY LOWER LEVEL WINDS
PROVIDE FOR SOME MOIST ADVECTION AS EVIDENT IN MODEL SOUNDINGS. FOR
TODAY THE PERTURBATION WILL NOT BE ASSOCIATED WITH THE UPPER LOW TO
OUR EAST BUT INSTEAD A SHORT WAVE AHEAD OF THE PACIFIC LOW PRESSURE
SYSTEM ALREADY MOVING ASHORE EARLY THIS MORNING OVER NORTHERN
CALIFORNIA AND THE PACIFIC NORTHWEST. NAM BOUNDARY LAYER CAPE IS
MODEST BUT MORE WIDESPREAD FOR LATE THIS AFTERNOON THAN IT WAS FOR
YESTERDAY. HRRR HAS HAD SEVERAL RUNS DEPICTING ISOLATED-SCATTERED
CONVECTION OVER CENTRAL AND EASTERN ARIZONA THIS AFTERNOON THOUGH IT
APPEARS TO BE THE MOST AGGRESSIVE OF THE HI-RES MODELS...ESPECIALLY
COMPARED TO LOCAL WRF. LATEST SSEO HINTS AT CONVECTION AFFECTING OUR
EASTERN AREAS. SPC HAS GENERAL THUNDER OVER THE EASTERN THIRD OF
ARIZONA. GIVEN ALL THIS...ADDED A SLIGHT CHANCE OF THUNDERSTORMS
THIS AFTERNOON AND EVENING OVER OUR PORTIONS OF PINAL AND GILA
COUNTIES. ALSO ADDED A MENTION OF PATCHY BLOWING DUST FOR OUR
PORTION OF PINAL COUNTY AS THUNDERSTORMS...IF ANY...WILL BE ABLE TO
PRODUCE SOME NOTABLE OUTFLOW GIVEN INVERTED V SOUNDINGS.
TONIGHT THROUGH THURSDAY...THE BRUNT OF THE AFOREMENTIONED PACIFIC
LOW PRESSURE SYSTEM WILL INITIALLY AFFECT AREAS WELL NORTH OF OUR
FORECAST AREA. HOWEVER...THERE WILL BE A DRY COLD FRONT THAT PUSHES
THROUGH SOUTHEAST CALIFORNIA AND ARIZONA BEGINNING TUESDAY NIGHT AND
CONTINUING WEDNESDAY. VERY STRONG NORTHERLY WINDS IN THE LOWER
LEVELS WILL BE ASSOCIATED WITH THE FRONTAL PASSAGE...MOST NOTABLY
FOR WESTERN PORTIONS OF OUR FORECAST AREA IN SOUTHEAST CALIFORNIA
AND SOUTHWEST ARIZONA. THUS A WIND ADVISORY IS IN EFFECT FOR THOSE
AREAS. AREAS OF BLOWING DUST/SAND WILL BE POSSIBLE AS WELL. VERY DRY
AIR WILL ALSO BE USHERED IN AND THE FIRE WEATHER WATCH WAS UPGRADED
TO A RED FLAG WARNING. SEE W/W/A SECTION BELOW FOR TIMING AND
AFFECTED ZONES. THE MODELS DEPICT THE UPPER TROUGH...INITIALLY
CENTERED WELL TO OUR NORTH...TRACKING SOUTHEASTWARD AND BECOMING A
CLOSED LOW OVER THE SOUTHERN ROCKIES/FOUR CORNERS AREA. THE GFS
CONTINUES TO HAVE IT CENTERED NORTHEAST OF THE ECMWF SOLUTION.
LATEST GEM IS MORE CLOSELY ALIGNED WITH ECMWF. THOSE MODELS ARE
GENERALLY SUPPORTED BY THEIR RESPECTIVE ENSEMBLE MEANS. THE ECMWF
AND GEM SOLUTIONS HAVING THE COLD CORE CLOSER TO OUR FORECAST AREA.
MEANWHILE...VORT LOBES/JET STREAKS ROTATE AROUND THE LOW.
HOWEVER...MOISTURE AVAILABILITY OVER OUR FORECAST AREA WILL BE QUITE
MEAGER SO HELD OFF ON INTRODUCING POPS. THERE WILL BE AT LEAST
LINGERING BREEZINESS...WINDY CONDITIONS WEDNESDAY NIGHT WITH ONE OF
THOSE VORT LOBES PUSHING THROUGH. BIGGEST BENEFIT OF THIS SYSTEM WILL
BE MUCH COOLER TEMPERATURES WEDNESDAY AND THURSDAY...AT LEAST A FEW
DEGREES BELOW NORMAL BY THURSDAY.
FRIDAY THROUGH MONDAY... THE LOW SLOWLY MOVES EASTWARD FRIDAY
THROUGH SUNDAY AND HEIGHTS/THICKNESSES REBOUND. ACCORDINGLY...A
WARMING TREND BEGINS FRIDAY WITH HIGHS BACK TO THE LOW 90S ON THE
LOWER ELEVATIONS BY SUNDAY. WEAK UNDERCUTTING OF THE RIDGE OVER THE
WEST EARLY NEXT WEEK KEEPS TEMPS FLAT.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
NO SIGNIFICANT AVIATION CONCERNS THROUGH TUESDAY AFTERNOON UNDER
MOSTLY CLEAR SKIES. SFC WINDS WILL FOLLOW TYPICAL DIURNAL PATTERNS
THROUGH TUESDAY MORNING...BECOMING MORE GUSTY FROM THE SOUTH AND
WEST TUESDAY AFTERNOON. OCCASIONAL GUSTS IN A 20 TO 25 KT RANGE WILL
BE COMMON LATER TUESDAY AFTERNOON.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
AN AREA OF LOW PRESSURE WILL CONTINUE TO MOVE THROUGH THE FOUR
CORNERS REGION THURSDAY AND FRIDAY. HOWEVER...DRY AIR WILL REMAIN
IN PLACE INTO THE WEEKEND...AND WITH VERY LITTLE ATMOSPHERIC
MOISTURE...THERE WILL BE NO PRECIPITATION...JUST SOME PASSING HIGH
CLOUDS. WINDS WILL BE MUCH LIGHTER THROUGH FRIDAY INTO THE WEEKEND.
EXPECT FAIR/POOR OVERNIGHT RECOVERIES DURING THE PERIOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...RED FLAG WARNING FROM 5 AM TO 11 PM MST WEDNESDAY FOR
AZZ131-132.
WIND ADVISORY FROM 2 AM TO 9 PM MST WEDNESDAY FOR AZZ020-021-
025-026.
CA...RED FLAG WARNING FROM 5 AM TO 11 PM PDT WEDNESDAY FOR CAZ231.
WIND ADVISORY FROM 2 AM TO 9 PM PDT WEDNESDAY FOR CAZ030>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
AVIATION....MO
FIRE WEATHER...MEYERS
AREA FORECAST DISCUSSION
NWS TUCSON AZ
300 AM MST TUE APR 14 2015
.SYNOPSIS...A FEW SHOWERS AND THUNDERSTORMS POSSIBLE AGAIN THIS
AFTERNOON. A STRONGER STORM SYSTEM DIGGING TOWARD THE REGION FROM
THE NORTHWEST WILL BRING STRONG GUSTY WINDS WEDNESDAY AND THURSDAY
ALONG WITH A SHOT OF MUCH COOLER AIR. UNSEASONABLY COLD OVERNIGHT
LOWS IN SOME LOCATIONS ARE POSSIBLE LATE IN THE WEEK.
&&
.DISCUSSION...WE CONTINUE TO HANG ON TO A REASONABLE AMOUNT OF
MOISTURE FOR A PERIOD IN BETWEEN SYSTEMS...WITH SURFACE DEW POINTS
IN THE 30S AND 40S ALONG WITH PRECIPITABLE WATER VALUES AROUND .5 TO
.7 INCHES. SHORT RANGE HIGH RESOLUTION MODELS SUCH AS THE HRRR AGAIN
SPRINKLE CONVECTION AROUND SOUTHEAST AND SOUTH CENTRAL ARIZONA THIS
AFTERNOON. A PARTICULAR FOCUS IS SETTING UP ASSOCIATED WITH A MID
LEVEL INFLECTION THROUGH CENTRAL PIMA COUNTY THIS AFTERNOON...SO WE
HAVE ADDED ISOLATED THUNDERSTORMS TO SOME AREAS WEST OF TUCSON AS
WELL.
STILL ON TRACK FOR A SIGNIFICANT SPLIT OF ENERGY FROM THE NORTHWEST
INTO THE FOUR CORNERS REGION OVER THE NEXT 48 HOURS. THIS WILL BRING
STRONG GUSTY WINDS ACROSS THE ENTIRE AREA WEDNESDAY WITH VERY DRY
AIR BEHIND AN ASSOCIATED COLD FRONT SWEEPING DOWN FROM THE NORTH
DURING THE DAY WEDNESDAY. THE RAPIDLY DRYING CONDITIONS AROUND MID
DAY THROUGH THE AFTERNOON AND EVENING IS LEADING US TO ISSUE A RED
FLAG WARNING FOR WEDNESDAY IN ASSOCIATION WITH FIRE WEATHER
HEADLINES ISSUED BY PSR. PLEASE SEE THE FIRE WEATHER DISCUSSION
BELOW FOR ADDITIONAL DETAILS.
THE LOW WILL THEN SAG INTO NORTHEAST ARIZONA AND NORTHWEST NEW
MEXICO THURSDAY...HOWEVER A DRY INLAND TRAJECTORY ON THIS SYSTEM
WILL SEE LIMITED MOISTURE FOR OUR AREA. VERY COOL AIR HOWEVER...WITH
TEMPERATURES AT LEAST 10 DEGREES BELOW CLIMATOLOGY THURSDAY.
UNSEASONABLY COOL OVERNIGHT LOWS THURSDAY NIGHT AND FRIDAY
NIGHT...WITH LATE SEASON FREEZING TEMPERATURES POSSIBLE IN COLDER
EASTERN VALLEY LOCATIONS INCLUDING SULPHUR SPRINGS VALLEY IN COCHISE
COUNTY. A DEFINITE CONCERN FOR AGRICULTURE IN SOUTHEAST ARIZONA.
&&
.AVIATION...VALID THRU 15/12Z.
SURFACE WINDS GENERALLY LESS THAN 12 KTS THIS MORNING UNDER MOSTLY
CLEAR SKIES. ISOLATED -SHRA/-TSRA POSSIBLE THIS AFTERNOON. WLY WINDS
8-12 KTS DURING THE DAY WITH SCT CLOUDS AOA 15K FT AGL. GUSTY ERRATIC
OUTFLOWS AT TIMES ASSOCIATED CONVECTION. NORMAL DIURNAL WIND TRENDS
RETURNING OVERNIGHT. A STRONG SYSTEM DIGGING DOWN FROM THE NORTH
WILL BRING WINDY CONDITIONS TO THE AREA WEDNESDAY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...BECOMING PARTLY CLOUDY WITH ISOLATED SHOWERS AND
THUNDERSTORMS AROUND THE AREA TODAY. STRONG GUSTY OUTFLOWS POSSIBLE
WITH SOME STORMS.
A DEVELOPING LOW PRESSURE SYSTEM IS EXPECTED TO DROP OUT OF THE
PACIFIC NW TONIGHT AND THEN MOVE OVER NORTHEAST ARIZONA LATE
WEDNESDAY INTO THURSDAY MORNING. THIS SYSTEM IS EXPECTED TO SPREAD
STRONG WINDS AND DRY AIR ACROSS THE AREA WEDNESDAY INTO THURSDAY AS
WELL AS MUCH COOLER TEMPERATURES THURSDAY. STRONG AND GUSTY WESTERLY
WINDS WEDNESDAY WITH FALLING RH VALUES THROUGH THE DAY ARE EXPECTED
TO CAUSE CRITICAL FIRE WEATHER CONDITIONS BY WEDNESDAY AFTERNOON
ACROSS MOST OF SOUTHEAST ARIZONA. A RED FLAG WARNING HAS BEEN ISSUED
FOR MOST OF SOUTHEAST ARIZONA FROM LATE WEDNESDAY MORNING INTO
WEDNESDAY EVENING.
THE DRY AIR WILL BE IN PLACE ON THURSDAY BUT THE WINDS WILL BE
SLIGHTLY WEAKER. WE WILL CONTINUE TO EVALUATE THURSDAY FOR ANY
POSSIBLE FIRE WEATHER CONCERNS. WINDS WILL DIMINISH SOMEWHAT BY
FRIDAY AFTERNOON INTO THE COMING WEEKEND WITH DRY CONDITIONS ACROSS
THE AREA.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...RED FLAG WARNING WEDNESDAY FROM
11 AM UNTIL 8 PM FOR MUCH OF SOUTHEAST ARIZONA INCLUDING FIRE
WEATHER ZONES AZZ150-151...NORTHERN PORTIONS OF 152....AND
SOUTHERN PORTIONS OF 153.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
MEYER/RASMUSSEN
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
726 AM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTH TODAY AND TONIGHT THEN
PASS THROUGH THE AREA WEDNESDAY. A WEDGE OF HIGH PRESSURE WILL
DEVELOP BEHIND THE FRONT AND STRENGTHEN THURSDAY AS A COASTAL
TROUGH DEVELOPS OFFSHORE. THE TROUGH WILL LIFT NORTHEAST UP THE
COAST FRIDAY...BEFORE A WEAK COLD FRONT CROSSES THE REGION LATE
SATURDAY. ANOTHER STORM SYSTEM IS EXPECTED TO IMPACT THE AREA LATE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE FORECAST PHILOSOPHY HAS CHANGED LITTLE FROM EARLIER THIS
MORNING. THE LATEST H3R AND RAP STILL SUPPORT GULF COAST SEA
BREEZE CONVECTION MOVING IN LATE...BUT DEGREE OF COVERAGE REMAINS
IN QUESTION. OPTED NOT TO MAKE ANY CHANGES TO THE GOING FORECAST
FOR NOW. MADE MINOR CHANGES TO SHORT TERM GRIDS FOR THE SUNRISE
UPDATE.
WARM FRONTAL REMNANTS ARE NOW NORTH OF THE FORECAST AREA PER
14/07Z SURFACE OBSERVATIONS. THE DECAYING BOUNDARY WILL CONTINUE
TO LIFT NORTH TODAY AND DISSIPATE AS LOW PRESSURE MOVES INTO THE
SOUTHERN APPALACHIANS ALONG AN ADVANCING COLD FRONT. 14/00Z UPPER
ANALYSIS DID NOT IDENTIFY ANY SIGNIFICANT UPSTREAM IMPULSES THAT
WILL CROSS THE AREA AT PEAK HEATING...SO EXPECT A MAINLY DIURNAL
CONVECTIVE PATTERN TO PREVAIL WITH THE AREA REMAINING ALONG THE
CONVERGENT SIDE OF THE MID-LEVEL RIDGE AXIS.
THERE APPEARS TO BE TWO FAVORED AREAS FOR ENHANCED CONVECTIVE
DEVELOPMENT TODAY. THE FIRST WILL BE ACROSS THE INTERIOR
PORTIONS OF SOUTHEAST SOUTH CAROLINA...ROUGHLY IN THE WALTERBORO-
JAMESTOWN...NORTH CHARLESTON CORRIDOR WHERE LOW-LEVEL CONVERGENCE
WILL BECOME MAXIMIZED BETWEEN THE INLAND MOVING SEA BREEZE AND THE
LAKE BREEZES AROUND LAKES MARION AND MOULTRIE. THE OTHER WILL BE
THE AREA SOUTH OF I-16...ESPECIALLY NEAR THE ALTAMAHA RIVER...WHERE
SCATTERED CONVECTION ASSOCIATED WITH THE GULF COAST SEA BREEZE
MOVING NORTHEAST OFF APALACHEE BAY WILL LIKELY APPROACH LATE AND
INTERACT WITH THE ATLANTIC SEA BREEZE. IT IS HARD TO JUSTIFY POPS
ANY HIGHER THAN 40-50 PERCENT IN THESE AREAS IN THE ABSENCE OF A
SIGNIFICANT UPPER LEVEL FORCING MECHANISM...BUT LOCALLY HIGHER
POPS MAY EVENTUALLY BE NEEDED AS SHORT TERM CONVECTIVE AND SURFACE
MESOSCALE TRENDS BECOME MORE APPARENT LATER TODAY. SHOWERS/TSTMS
WILL BE MORE SPORADIC AND MAINLY DRIVEN BY AIRMASS DESTABILIZATION
FOR THE REMAINING PORTIONS OF THE FORECAST AREA. THIS JUSTIFIES
POPS OF 20-30 PERCENT. THERMODYNAMIC PROFILES ARE NOT OVERLY
IMPRESSIVE PER MODIFIED MODEL POINT SOUNDINGS SO THE RISK FOR
SEVERE TSTMS LOOK MINIMAL...ALTHOUGH GUSTY WINDS...TORRENTIAL
DOWNPOURS AND CLOUD-TO-GROUND LIGHTNING STRIKES WILL STILL POSE A
HAZARD.
EXTENSIVE CLOUD COVER THIS MORNING WILL GRADUALLY THIN WITH TIME
WITH SKIES LIKELY BECOMING PARTLY CLOUDY FOR MANY AREAS. THIS
INCREASED INSOLATION COUPLED WITH 850 HPA TEMPERATURES RISING TO
14-16C WILL SUPPORT HIGHS IN THE MID-UPPER 80S. THERE IS EVEN AN
OUTSIDE SHOT OF A FEW 90 DEGREE READINGS IN THE I-95 CORRIDOR FROM
ROUGHLY SAVANNAH SOUTH TO DARIEN...INCLUDING LUDOWICI AND
HINESVILLE. THE RAP/NAM12 AND H3R ALL SHOW READINGS 87-89 DEGREES
IN THIS AREA BEFORE THE ARRIVAL OF THE ATLANTIC SEA BREEZE AND
CONVECTION MOVING IN FROM THE SOUTHWEST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...DIURNAL SHOWER/TSTM ACTIVITY WILL GRADUALLY DIMINISH WITH
THE LOSS OF INSOLATION...ALTHOUGH IT MAY TAKE A GOOD PORTION OF
THE EVENING FOR THE ACTIVITY PROPAGATING IN AHEAD OF THE GULF
COAST SEA BREEZE TO PUSH OFF THE GEORGIA COAST. EXPECT MAINLY DRY
CONDITIONS TO PREVAIL FOR A GOOD PORTION THE NIGHT. A BACKDOOR
COLD FRONT WILL APPROACH FROM THE NORTH LATE...BUT THIS BOUNDARY
SHOULD REMAIN NORTH OF THE SANTEE RIVER THROUGH SUNRISE. THERE MAY
BE JUST ENOUGH LOW-LEVEL CONVERGENCE AHEAD OF THE FRONT TO SUPPORT
ISOLATED SHOWERS ACROSS THE CHARLESTON TRI-COUNTY AREA AFTER 4-5
AM...SO SLIGHT CHANCE POPS WILL BE DEPICTED IN THIS AREA. IT WILL
OTHERWISE BE ANOTHER WARM AND HUMID NIGHT WITH LOWS ONLY DROPPING
INTO THE UPPER 60S.
WEDNESDAY...AT DAYBREAK A BACKDOOR COLD FRONT WILL BE SLOWLY
DESCENDING SOUTH INTO THE NORTHERN PORTIONS OF THE FORECAST AREA. AS
THE FRONT SINKS FURTHER SOUTH THROUGH THE DAY...A WEDGE OF HIGH
PRESSURE WILL DEVELOP BEHIND IT. CONTINUED DEEP MOISTURE FEED FROM
THE TROPICAL PACIFIC AND GULF OF MEXICO WILL RESULT IN PWATS OF
AROUND 1.75 INCHES...OR ABOUT 2 STANDARD DEVIATIONS ABOVE NORMAL.
THIS IN COMBINATION WITH SHORTWAVE ENERGY EJECTING OUT THE SOUTHWEST
FLOW WILL RESULT IN HIGH CHANCE/LIKELY POPS. WEAK INSTABILITY MAINLY
IN SOUTHEAST GEORGIA WILL KEEP A SLIGHT CHANCE OF THUNDER MENTION IN
THE FORECAST IN THE AFTERNOON. OTHER CONVECTIVE PARAMETERS ARE
RATHER POOR SO SEVERE THREAT IS PRETTY LOW. BY SUNSET...THE FRONT
SHOULD BE LOCATED NEAR OR SOUTH OF THE ALTAMAHA. HIGH TEMPERATURES
WILL RANGE FROM THE MID 70S IN OUR NORTHERN ZONES...TO AROUND 80
SOUTH. WEDNESDAY NIGHT...THE ILL-DEFINED FRONT WILL TRANSITION INTO
A COASTAL TROUGH...ACTING TO STRENGTHEN THE INLAND HIGH PRESSURE
WEDGE. ELEVATED MOISTURE AND ENHANCED LOW LEVEL CONVERGENCE WILL
KEEP SHOWERS IN THE FORECAST OVERNIGHT. LOWS WILL BE RANGE FROM THE
UPPER 50S TO MID 60S.
THURSDAY...THE COASTAL TROUGH WILL LIKELY CLOSE OFF AS A SURFACE LOW
AND BEGIN TO MOVE NORTHEAST UP THE COAST. HIGHEST RAIN CHANCES WILL
BE IN MORNING/EARLY AFTERNOON BEFORE THE BEST MOISTURE SHIFTS NORTH
WITH THE SURFACE LOW. COOL NORTH/NORTHEAST FLOW AND OVERCAST SKIES
WILL KEEP HIGHS BELOW NORMAL...RANGING FROM THE UPPER 60S TO LOW/MID
70S. THURSDAY NIGHT...THE WEDGE WILL BEGIN TO WEAKEN AS THE LOW
CONTINUES TO LIFT NORTHEAST ALONG THE CAROLINA COAST. THERE WILL
LIKELY BE SOMEWHAT OF A BREAK IN PRECIPITATION AND FORECAST
CURRENTLY ONLY HAS SLIGHT CHANCE/CHANCE POPS. LOWS WILL BE IN THE
UPPER 50S/LOW 60S.
FRIDAY...FRIDAY WILL BE MORE OF A TRANSITIONAL DAY WITH A RATHER
WEAK/DIFFUSE PRESSURE PATTERN. DESPITE THE FORECAST AREA REMAINING
UNDER THE PERSISTENT MOISTURE FEED...RAIN CHANCES WILL BE CAPPED AT
20-30 PERCENT SINCE THERE DOES NOT SEEM TO BE MUCH FOCUS OR FORCING
CONVECTION. HIGH TEMPERATURES WILL MODERATE BACK TO NORMAL...IN THE
MID/UPPER 70S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODELS HAVE BEEN PRETTY INCONSISTENT IN THE LONG TERM PERIOD SO
FORECAST CONFIDENCE IS QUITE LOW. A WEAK COLD FRONT WILL DROP
THROUGH THE REGION LATE SATURDAY. TRANSIENT HIGH PRESSURE WILL
PREVAIL ON SUNDAY AHEAD OF THE NEXT STORM SYSTEM BREWING IN THE
MIDWEST WHICH WILL AFFECT THE FORECAST AREA EARLY NEXT WEEK.
ELEVATED MOISTURE AND A SERIES OF UPPER LEVEL DISTURBANCES WILL
KEEP RAIN CHANCES IN THE FORECAST FOR MUCH OF THE PERIOD.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
LOW CLOUDS AT KCHS ARE POISED TO MIX OUT 12-13Z. VFR DOMINATING
KCHS/KSAV FOR MUCH OF THE DAY. SHOWERS/TSTMS COULD IMPACT THE
TERMINAL AT ANY TIME TODAY...BUT CELLS LOOK TRANSIENT ENOUGH THAT
ANY IMPACTS WILL BE BRIEF. COULD SEE A MORE ORGANIZED TSTM CLUSTER
APPROACH KSAV LATE AFTERNOON/SUNSET AS THE GULF SEA BREEZE
APPROACHES FROM THE SOUTHWEST. CONFIDENCE IN TIMING IS TOO LOW TO
INCLUDE A MENTION JUST YET. MVFR CIGS ARE POSSIBLE JUST BEFORE
SUNRISE WEDNESDAY AT KCHS AS A COLD FRONT APPROACHES FROM THE
NORTH.
EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS LIKELY AT TIMES
THROUGH THE WEEK AS PERIODIC SHOWERS/TSTMS IMPACT THE TERMINALS.
&&
.MARINE...
TODAY...SOUTH TO SOUTHWEST WINDS WILL PREVAIL TODAY WITH WINDS
GENERALLY 10 KT OR LESS. A ROBUST SEA BREEZE WILL TAKE SHAPE ALONG
THE BEACHES BY EARLY AFTERNOON...WHICH WILL ENHANCE WIND FIELDS
NEAR THE BEACHES AND THE CHARLESTON HARBOR. WINDS SHOULD REACH AS
HIGH AS 15 KT IN THE CHARLESTON HARBOR FOR MID-LATE AFTERNOON AS
THE SEA BREEZE MOVES INLAND. LOWS WILL AVERAGE 2-4 FT...HIGHEST
OFFSHORE WATERS.
TONIGHT...SOUTHWEST WINDS AROUND 10 KT WILL PREVAIL AHEAD OF AN
ADVANCING COLD FRONT. SEAS WILL AVERAGE 2-3 FT.
WEDNESDAY THROUGH MONDAY...A BACKDOOR COLD FRONT WILL DESCEND SOUTH
ACROSS THE WATERS ON WEDNESDAY...WITH A WEDGE OF HIGH PRESSURE
BUILDING IN ITS WAKE. WEDNESDAY NIGHT INTO THURSDAY...A COASTAL
TROUGH WILL DEVELOP OFFSHORE ALLOWING THE INLAND WEDGE TO
STRENGTHEN. GIVEN A TIGHTENING PRESSURE GRADIENT AND DECENT PRESSURE
RISES...WINDS AND SEAS WILL BUILD. SMALL CRAFT ADVISORIES MAY BE
NEEDED FOR WEDNESDAY NIGHT INTO THURSDAY...ESPECIALLY ACROSS THE
SOUTH CAROLINA COASTAL WATERS...AS NORTHEAST WINDS GUST TO 25 KT AND
SEAS BUILD TO 4-6 FEET. IN ADDITION...THERE WILL BE AN ENHANCED RISK
OF RIP CURRENTS DURING THIS TIME. THURSDAY NIGHT...THE COASTAL
TROUGH WILL CLOSE OFF AND BEGIN TO MOVE NORTHEAST UP THE COAST
ALLOWING THE PRESSURE GRADIENT TO RELAX. TRANSIENT HIGH PRESSURE
WILL PREVAIL FRIDAY BEFORE A WEAK COLD FRONT IMPACTS THE WATERS
SATURDAY NIGHT. AT THIS TIME...WINDS/SEAS ARE EXPECTED TO REMAIN
BELOW HEADLINE CRITERIA. ANOTHER STORM SYSTEM IS EXPECTED TO AFFECT
REGION EARLY NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
A COMBINATION OF ASTRONOMICAL HIGH TIDES AND LEFTOVER NORTHEAST
WINDS/SWELL WILL RESULT IN A THREAT FOR SHALLOW COASTAL FLOODING
NEAR THE TIME OF HIGH TIDE THURSDAY AND FRIDAY EVENING...PERHAPS
EXTENDING INTO THE SATURDAY EVENING HIGH TIDE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/ECT
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1037 AM EDT Tue Apr 14 2015
...Forecast Update...
Issued at 1035 AM EDT Tue Apr 14 2015
Band continues over southern Indiana, but also still have some light
to moderate rains over Kentucky. Pattern resembles a setup that
would generate a lot of snow in the winter, but fortunately we are
20-30 degrees warmer! Despite the lifting of the shortwave, into
Indiana now, we still have quite a bit of low-level lift to deal
with for a few more hours, so have raised pops some more into the
afternoon hours.
As for the Flood Watch, will let that expire at 15Z as planned.
Already have upgraded to areal flood warnings in most of the watch
locations, so no more need for a double product. Will update the
zones at 15Z to remove that headline.
Issued at 930 AM EDT Tue Apr 14 2015
Heaviest band of precip has lifted north into southern Indiana, but
continue with moderate rains over our east and southeast counties.
Areal flood warnings are out with several reports of water over
roads coming in for those areas. We should not have such a problem
over the north, but will keep watch over the next hour or two until
the shortwave noted on water vapor imagery kicks out of here and the
forcing for these rains dies down.
Issued at 650 AM EDT Tue Apr 14 2015
Just a quick update on latest trends. Widespread rain continues at
this time over most of central KY as the mid-level shortwave heads
northeast across western TN at this time. Pockets of moderate to
heavy rain are occurring throughout the region. This could cause
significant ponding of water on some roads and low-lying areas, and
some creeks could possibly overflow. However, have received no
reports of flooding at this time.
06z models and latest HRRR reflecting radar trends well. The sharp
northern edge of the rain along and south of the OH River has
relaxed some and spread a bit farther north as expected. A few
heavier rain elements are now showing up near Evansville and just
northeast of Louisville. The heaviest steadiest rains will remain
within the Flood Watch area, but showers will spread northeast
across much of south-central IN over the next hour or two.
Otherwise, forecast is on track with just some tweaks to hourly POPs
to match latest trends.
.SHORT TERM (Now through Wednesday)...
Issued at 315 AM EDT Tue Apr 14 2015
...Flood Watch continues this morning for parts of central KY...
A solid area of rain has evolved in a WSW-ENE axis across central
KY early this morning, ahead of a pronounced shortwave in water
vapor imagery moving from AR/MS into western TN and an associated
surface low pressure system. Within this rain are numerous areas of
moderate rain. At this time, there is a distinct northern boundary
to the rain along and just south of the OH River associated with a
deformation zone. The latest few HRRR runs have shown that rain just
ahead of the shortwave may move a little farther north and be slower
to depart than previous forecasts, which the 00z NAM also hinted at.
These models are slower and farther north than the 00z GFS, which
seems reasonable. Thus, despite the current tight northern precip
edge, more showers should move back across the Louisville metro and
into at least parts of south-central IN later this morning,
continuing during much of the morning. However, the heaviest rain
should continue to fall out in an axis to the east of the shortwave.
The current Flood Watch looks good, although decent rains will fall
a county or so north of the Watch as well, but will keep the area
unchanged at this time. The overall trend should be for more bands
of showers to form east of the shortwave then rotate north and east.
This should keep highest rainfall totals in an axis from about BWG
to LEX and a row of counties or so south. Still looks like 1 to 2
inches of rain is a good bet in this axis, with locally 2+ inches
possible in a few spots. However, since rainfall is not truly
convective and since rain rates should not increase much more than
at present, widespread flash flooding is not likely. Instead,
significant ponding and some areal flooding of roads, low-lying
areas, creeks, and small streams may occur. Slightly lower rain
totals are expected over our extreme southeast south-central KY
counties. While showers will continue past the 15 UTC expiration
time of the Watch, will not change it at this time. This can be
locally extended if need be later this morning pending latest trends
and reports.
Rainfall will diminish this afternoon for most areas, but scattered
showers should continue over our east and southeast counties
overcast skies persist. Over south-central IN, some breaks in the
clouds could occur later this afternoon.
High temperatures today are tricky. Values at this time may not go
up much if any today. Matter of fact, could see readings fall a bit
as a brisk northeast wind develops along with the low clouds and
showers in parts of central KY. Will keep readings in the upper 50s
over much of east-central KY west-southwestward, with lower-mid 60s
for south-central KY, again with highest values this morning. Also,
expect lower-mid 60s in south-central IN where low clouds will scour
out and showers will end this afternoon. Lows tonight should range
from the mid 40s to lower 50s with a cloudy sky south and east, and
partly to mostly cloudy north and west.
On Wednesday, mid-level flow will begin to back again, resulting in
clouds moving back northward. There could be some scattered showers
especially across south-central KY, although there are no clear
forcing mechanics at this time. Expect highs in the mid 60s to lower
70s.
.LONG TERM (Wednesday Night through Monday)...
Issued at 325 AM EDT Tue Apr 14 2015
...Above Normal Rainfall Expected This Week...
In general terms, there is not a whole lot of change in the guidance
for the extended forecast period. The synoptic flow aloft will be
characterized by a fast northern jet flow confined to the
US/Canadian border region, while a split flow pattern will be in
place across the western US with a cut off low in the southern
stream. Multiple wave packets will eject out of the southern stream
and pass through the region in the mid-late part of the week,
bringing precipitation with the potential for heavy rainfall. By
late in the period, the cut off low over the SW US is expected to
lift out and merge with a northern stream wave which looks to turn
into a rather large gyre over the northern Great Lakes by early next
week. This would bring drier and cooler than normal conditions to
the region.
It does appear that we`ll see the first wave push through the region
on Thursday with a secondary wave coming in Friday night and early
Saturday. Combination of lift with the associated waves and plenty
of Gulf moisture will lead to widespread rainfall, some heavy, which
could result in renewed hydrologic concerns through the period.
This would be especially true across our southern half of the
forecast area...mainly south of the Parkways. The weekend does not
look to be an entire wash out, but Saturday morning will probably
remain a bit unsettled as the aforementioned wave ejects through the
region. There is a growing consensus in the data that upper level
ridging will build in during the afternoon to allow the region to
dry out a bit. Thus, will continue to run chance PoPs in the
forecast for the early part of Saturday and then allow PoPs to
decrease throughout the remainder of the day and into Sunday.
As the upper low out over the southwest US lifts out and combines
with the northern stream wave pushing through, we should see a
return of wet weather as we head into late Sunday and Monday. More
showers with some thunderstorms looks likely.
As for temperatures, have generally stuck close to the SuperBlend
consensus guidance for temperatures. This will result in daytime
highs generally in the upper 60s to the lower 70s for highs and
overnight lows in the 50s. These temperature forecasts will likely
see some sort of modulation in subsequent forecasts as the timing
issues in the upper level waves moving through the area become more
clearly defined in the coming days.
&&
.AVIATION (12Z TAF Update)...
Updated at 645 AM EDT Tue Apr 14 2015
Widespread rain continues this morning, affecting BWG the most with
some IFR ceilings from time to time and reduced visibility in
moderate to heavy rain. LEX ceiling continues to change between IFR
and MVFR, but MVFR should be the prevailing category for much of the
rest of the morning. Expect SDF ceiling to mostly stay VFR, but
can`t rule out MVFR at times this morning.
These conditions will continue for the morning hours with improving
conditions this afternoon at SDF and LEX. However, it is unclear
whether clouds will lift enough for VFR conditions at BWG this
afternoon and tonight. Will keep MVFR as low clouds below 3 kft
should remain. Also, could see at least MVFR visibilities due to fog
early Wednesday morning at BWG.
Expect surface winds from the north-northeast at 10-15 kts with
gusts around or above 20 kts at times this morning into early
afternoon in response to low pressure moving east-northeast across
the TN Valley.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FLOOD WATCH until 11 AM EDT /10 AM CDT/ this morning FOR
KYZ040>043-046>049-053>057-061>067-070>078-081-082.
IN...NONE.
&&
$$
Updates........RJS/TWF
Short Term.....TWF
Long Term......MJ
Aviation.......TWF
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
934 AM EDT Tue Apr 14 2015
...Forecast Update...
Issued at 930 AM EDT Tue Apr 14 2015
Heaviest band of precip has lifted north into southern Indiana, but
continue with moderate rains over our east and southeast counties.
Areal flood warnings are out with several reports of water over
roads coming in for those areas. We should not have such a problem
over the north, but will keep watch over the next hour or two until
the shortwave noted on water vapor imagery kicks out of here and the
forcing for these rains dies down.
Issued at 650 AM EDT Tue Apr 14 2015
Just a quick update on latest trends. Widespread rain continues at
this time over most of central KY as the mid-level shortwave heads
northeast across western TN at this time. Pockets of moderate to
heavy rain are occurring throughout the region. This could cause
significant ponding of water on some roads and low-lying areas, and
some creeks could possibly overflow. However, have received no
reports of flooding at this time.
06z models and latest HRRR reflecting radar trends well. The sharp
northern edge of the rain along and south of the OH River has
relaxed some and spread a bit farther north as expected. A few
heavier rain elements are now showing up near Evansville and just
northeast of Louisville. The heaviest steadiest rains will remain
within the Flood Watch area, but showers will spread northeast
across much of south-central IN over the next hour or two.
Otherwise, forecast is on track with just some tweaks to hourly POPs
to match latest trends.
.SHORT TERM (Now through Wednesday)...
Issued at 315 AM EDT Tue Apr 14 2015
...Flood Watch continues this morning for parts of central KY...
A solid area of rain has evolved in a WSW-ENE axis across central
KY early this morning, ahead of a pronounced shortwave in water
vapor imagery moving from AR/MS into western TN and an associated
surface low pressure system. Within this rain are numerous areas of
moderate rain. At this time, there is a distinct northern boundary
to the rain along and just south of the OH River associated with a
deformation zone. The latest few HRRR runs have shown that rain just
ahead of the shortwave may move a little farther north and be slower
to depart than previous forecasts, which the 00z NAM also hinted at.
These models are slower and farther north than the 00z GFS, which
seems reasonable. Thus, despite the current tight northern precip
edge, more showers should move back across the Louisville metro and
into at least parts of south-central IN later this morning,
continuing during much of the morning. However, the heaviest rain
should continue to fall out in an axis to the east of the shortwave.
The current Flood Watch looks good, although decent rains will fall
a county or so north of the Watch as well, but will keep the area
unchanged at this time. The overall trend should be for more bands
of showers to form east of the shortwave then rotate north and east.
This should keep highest rainfall totals in an axis from about BWG
to LEX and a row of counties or so south. Still looks like 1 to 2
inches of rain is a good bet in this axis, with locally 2+ inches
possible in a few spots. However, since rainfall is not truly
convective and since rain rates should not increase much more than
at present, widespread flash flooding is not likely. Instead,
significant ponding and some areal flooding of roads, low-lying
areas, creeks, and small streams may occur. Slightly lower rain
totals are expected over our extreme southeast south-central KY
counties. While showers will continue past the 15 UTC expiration
time of the Watch, will not change it at this time. This can be
locally extended if need be later this morning pending latest trends
and reports.
Rainfall will diminish this afternoon for most areas, but scattered
showers should continue over our east and southeast counties
overcast skies persist. Over south-central IN, some breaks in the
clouds could occur later this afternoon.
High temperatures today are tricky. Values at this time may not go
up much if any today. Matter of fact, could see readings fall a bit
as a brisk northeast wind develops along with the low clouds and
showers in parts of central KY. Will keep readings in the upper 50s
over much of east-central KY west-southwestward, with lower-mid 60s
for south-central KY, again with highest values this morning. Also,
expect lower-mid 60s in south-central IN where low clouds will scour
out and showers will end this afternoon. Lows tonight should range
from the mid 40s to lower 50s with a cloudy sky south and east, and
partly to mostly cloudy north and west.
On Wednesday, mid-level flow will begin to back again, resulting in
clouds moving back northward. There could be some scattered showers
especially across south-central KY, although there are no clear
forcing mechanics at this time. Expect highs in the mid 60s to lower
70s.
.LONG TERM (Wednesday Night through Monday)...
Issued at 325 AM EDT Tue Apr 14 2015
...Above Normal Rainfall Expected This Week...
In general terms, there is not a whole lot of change in the guidance
for the extended forecast period. The synoptic flow aloft will be
characterized by a fast northern jet flow confined to the
US/Canadian border region, while a split flow pattern will be in
place across the western US with a cut off low in the southern
stream. Multiple wave packets will eject out of the southern stream
and pass through the region in the mid-late part of the week,
bringing precipitation with the potential for heavy rainfall. By
late in the period, the cut off low over the SW US is expected to
lift out and merge with a northern stream wave which looks to turn
into a rather large gyre over the northern Great Lakes by early next
week. This would bring drier and cooler than normal conditions to
the region.
It does appear that we`ll see the first wave push through the region
on Thursday with a secondary wave coming in Friday night and early
Saturday. Combination of lift with the associated waves and plenty
of Gulf moisture will lead to widespread rainfall, some heavy, which
could result in renewed hydrologic concerns through the period.
This would be especially true across our southern half of the
forecast area...mainly south of the Parkways. The weekend does not
look to be an entire wash out, but Saturday morning will probably
remain a bit unsettled as the aforementioned wave ejects through the
region. There is a growing consensus in the data that upper level
ridging will build in during the afternoon to allow the region to
dry out a bit. Thus, will continue to run chance PoPs in the
forecast for the early part of Saturday and then allow PoPs to
decrease throughout the remainder of the day and into Sunday.
As the upper low out over the southwest US lifts out and combines
with the northern stream wave pushing through, we should see a
return of wet weather as we head into late Sunday and Monday. More
showers with some thunderstorms looks likely.
As for temperatures, have generally stuck close to the SuperBlend
consensus guidance for temperatures. This will result in daytime
highs generally in the upper 60s to the lower 70s for highs and
overnight lows in the 50s. These temperature forecasts will likely
see some sort of modulation in subsequent forecasts as the timing
issues in the upper level waves moving through the area become more
clearly defined in the coming days.
&&
.AVIATION (12Z TAF Update)...
Updated at 645 AM EDT Tue Apr 14 2015
Widespread rain continues this morning, affecting BWG the most with
some IFR ceilings from time to time and reduced visibility in
moderate to heavy rain. LEX ceiling continues to change between IFR
and MVFR, but MVFR should be the prevailing category for much of the
rest of the morning. Expect SDF ceiling to mostly stay VFR, but
can`t rule out MVFR at times this morning.
These conditions will continue for the morning hours with improving
conditions this afternoon at SDF and LEX. However, it is unclear
whether clouds will lift enough for VFR conditions at BWG this
afternoon and tonight. Will keep MVFR as low clouds below 3 kft
should remain. Also, could see at least MVFR visibilities due to fog
early Wednesday morning at BWG.
Expect surface winds from the north-northeast at 10-15 kts with
gusts around or above 20 kts at times this morning into early
afternoon in response to low pressure moving east-northeast across
the TN Valley.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FLOOD WATCH until 11 AM EDT /10 AM CDT/ this morning FOR
KYZ040>043-046>049-053>057-061>067-070>078-081-082.
IN...NONE.
&&
$$
Updates........RJS/TWF
Short Term.....TWF
Long Term......MJ
Aviation.......TWF
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
656 AM EDT Tue Apr 14 2015
...Updated Forecast and Aviation Discussions...
...Forecast Update...
Issued at 650 AM EDT Tue Apr 14 2015
Just a quick update on latest trends. Widespread rain continues at
this time over most of central KY as the mid-level shortwave heads
northeast across western TN at this time. Pockets of moderate to
heavy rain are occurring throughout the region. This could cause
significant ponding of water on some roads and low-lying areas, and
some creeks could possibly overflow. However, have received no
reports of flooding at this time.
06z models and latest HRRR reflecting radar trends well. The sharp
northern edge of the rain along and south of the OH River has
relaxed some and spread a bit farther north as expected. A few
heavier rain elements are now showing up near Evansville and just
northeast of Louisville. The heaviest steadiest rains will remain
within the Flood Watch area, but showers will spread northeast
across much of south-central IN over the next hour or two.
Otherwise, forecast is on track with just some tweaks to hourly POPs
to match latest trends.
.SHORT TERM (Now through Wednesday)...
Issued at 315 AM EDT Tue Apr 14 2015
...Flood Watch continues this morning for parts of central KY...
A solid area of rain has evolved in a WSW-ENE axis across central
KY early this morning, ahead of a pronounced shortwave in water
vapor imagery moving from AR/MS into western TN and an associated
surface low pressure system. Within this rain are numerous areas of
moderate rain. At this time, there is a distinct northern boundary
to the rain along and just south of the OH River associated with a
deformation zone. The latest few HRRR runs have shown that rain just
ahead of the shortwave may move a little farther north and be slower
to depart than previous forecasts, which the 00z NAM also hinted at.
These models are slower and farther north than the 00z GFS, which
seems reasonable. Thus, despite the current tight northern precip
edge, more showers should move back across the Louisville metro and
into at least parts of south-central IN later this morning,
continuing during much of the morning. However, the heaviest rain
should continue to fall out in an axis to the east of the shortwave.
The current Flood Watch looks good, although decent rains will fall
a county or so north of the Watch as well, but will keep the area
unchanged at this time. The overall trend should be for more bands
of showers to form east of the shortwave then rotate north and east.
This should keep highest rainfall totals in an axis from about BWG
to LEX and a row of counties or so south. Still looks like 1 to 2
inches of rain is a good bet in this axis, with locally 2+ inches
possible in a few spots. However, since rainfall is not truly
convective and since rain rates should not increase much more than
at present, widespread flash flooding is not likely. Instead,
significant ponding and some areal flooding of roads, low-lying
areas, creeks, and small streams may occur. Slightly lower rain
totals are expected over our extreme southeast south-central KY
counties. While showers will continue past the 15 UTC expiration
time of the Watch, will not change it at this time. This can be
locally extended if need be later this morning pending latest trends
and reports.
Rainfall will diminish this afternoon for most areas, but scattered
showers should continue over our east and southeast counties
overcast skies persist. Over south-central IN, some breaks in the
clouds could occur later this afternoon.
High temperatures today are tricky. Values at this time may not go
up much if any today. Matter of fact, could see readings fall a bit
as a brisk northeast wind develops along with the low clouds and
showers in parts of central KY. Will keep readings in the upper 50s
over much of east-central KY west-southwestward, with lower-mid 60s
for south-central KY, again with highest values this morning. Also,
expect lower-mid 60s in south-central IN where low clouds will scour
out and showers will end this afternoon. Lows tonight should range
from the mid 40s to lower 50s with a cloudy sky south and east, and
partly to mostly cloudy north and west.
On Wednesday, mid-level flow will begin to back again, resulting in
clouds moving back northward. There could be some scattered showers
especially across south-central KY, although there are no clear
forcing mechanics at this time. Expect highs in the mid 60s to lower
70s.
.LONG TERM (Wednesday Night through Monday)...
Issued at 325 AM EDT Tue Apr 14 2015
...Above Normal Rainfall Expected This Week...
In general terms, there is not a whole lot of change in the
guidance for the extended forecast period. The synoptic flow aloft
will be characterized by a fast northern jet flow confined to the
US/Canadian border region, while a split flow pattern will be in
place across the western US with a cut off low in the southern
stream. Multiple wave packets will eject out of the southern
stream and pass through the region in the mid-late part of the
week, bringing precipitation with the potential for heavy
rainfall. By late in the period, the cut off low over the SW US is
expected to lift out and merge with a northern stream wave which
looks to turn into a rather large gyre over the northern Great
Lakes by early next week. This would bring drier and cooler than
normal conditions to the region.
It does appear that we`ll see the first wave push through the region
on Thursday with a secondary wave coming in Friday night and early
Saturday. Combination of lift with the associated waves and plenty
of Gulf moisture will lead to widespread rainfall, some heavy, which
could result in renewed hydrologic concerns through the period.
This would be especially true across our southern half of the
forecast area...mainly south of the Parkways. The weekend does not
look to be an entire wash out, but Saturday morning will probably
remain a bit unsettled as the aforementioned wave ejects through the
region. There is a growing consensus in the data that upper level
ridging will build in during the afternoon to allow the region to
dry out a bit. Thus, will continue to run chance PoPs in the
forecast for the early part of Saturday and then allow PoPs to
decrease throughout the remainder of the day and into Sunday.
As the upper low out over the southwest US lifts out and combines
with the northern stream wave pushing through, we should see a
return of wet weather as we head into late Sunday and Monday. More
showers with some thunderstorms looks likely.
As for temperatures, have generally stuck close to the SuperBlend
consensus guidance for temperatures. This will result in daytime
highs generally in the upper 60s to the lower 70s for highs and
overnight lows in the 50s. These temperature forecasts will likely
see some sort of modulation in subsequent forecasts as the timing
issues in the upper level waves moving through the area become more
clearly defined in the coming days.
&&
.AVIATION (12Z TAF Update)...
Updated at 645 AM EDT Tue Apr 14 2015
Widespread rain continues this morning, affecting BWG the most with
some IFR ceilings from time to time and reduced visibility in
moderate to heavy rain. LEX ceiling continues to change between IFR
and MVFR, but MVFR should be the prevailing category for much of the
rest of the morning. Expect SDF ceiling to mostly stay VFR, but
can`t rule out MVFR at times this morning.
These conditions will continue for the morning hours with improving
conditions this afternoon at SDF and LEX. However, it is unclear
whether clouds will lift enough for VFR conditions at BWG this
afternoon and tonight. Will keep MVFR as low clouds below 3 kft
should remain. Also, could see at least MVFR visibilities due to fog
early Wednesday morning at BWG.
Expect surface winds from the north-northeast at 10-15 kts with
gusts around or above 20 kts at times this morning into early
afternoon in response to low pressure moving east-northeast across
the TN Valley.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FLOOD WATCH until 11 AM EDT /10 AM CDT/ this morning FOR
KYZ040>043-046>049-053>057-061>067-070>078-081-082.
IN...NONE.
&&
$$
Update.........TWF
Short Term.....TWF
Long Term......MJ
Aviation.......TWF
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
800 AM CDT TUE APR 14 2015
...SOUNDING DISCUSSION...
AS HAS BEEN THE CASE WITH THE AIRMASS THIS WEEK... THE SOUNDING
THIS MORNING DEPICTS ANOTHER VERY MOIST AND UNSTABLE AIRMASS. CAPE
IS HIGH WITH MIXED LAYER AT 3000 J/KG AND MID LEVEL LAPSE RATES
ARE STEEP AT 6.5 C/KM. NOT MUCH SHEAR THOUGH WITH SOUTHWESTERLY
WINDS THROUGHOUT THE PROFILE. THE LOW LEVEL ENVIRONMENT IS
SATURATED TO 925 MB. PW IS 1.88 INCHES... WHICH LIKE YESTERDAY IS
ANOTHER RECORD MAX FOR TODAY IN THE SPC DAILY CLIMATOLOGY. STORMS
TODAY ARE AGAIN VERY EFFICIENT RAIN MAKERS.
KRAUTMANN
&&
.PREV DISCUSSION... /ISSUED 411 AM CDT TUE APR 14 2015/
SHORT TERM...
IF YOU ARE LOOKING FOR A BREAK IN THE RAIN DO NOT HOLD YOUR
BREATH. THE NEXT ROUND OF SHOWERS AND THUNDERSTORMS ARE BEGINNINGTO
DEVELOP TO THE WEST JUST OUTSIDE OF OUR FORECAST AREA. EXPECT
SHOWERS AND THUNDERSTORMS TO CONTINUE TO DEVELOP THROUGH THE
MORNING HOURS AND MOVE OVER THE FORECAST AREA. WITH PRECIPITATBLE
WATER VALUES STILL WELL ABOVE NORMAL...DEEP ONSHORE FLOW AND THE
INSTABILITY FORECAST TO BE AROUND TODAY...EXPECT SHOWERS AND
STORMS TO BE VERY EFFICIENT RAINFALL PRODUCERS. THE STORM
PREDICTION CENTER HIGHLIGHTS PORTIONS OF OUR AREA IN A MARGINAL
RISK FOR SEVERE WEATHER TODAY BUT THE MAIN ISSUE WILL BE THE HEAVY
RAINFALL...THATS NOT TO SAY THAT ONE OR TO STORMS MAY BE STRONG OR
EVEN SEVERE. THE WEATHER PREDICTION CENTER HAS SOUTHEAST LOUISIANA
AND THE MISSISSIPPI GULF COAST IN A SLIGHT RISK FOR EXCESSIVE
RAINFALL. THIS MEANS THAT HEAVY RAINFALL CAN BE EXPECTED IN THE
AREA. AN ADDITIONAL 1 TO 3 INCHES OF RAINFALL IS POSSIBLE TODAY
OVER THE AREA ESPECIALLY IF YOU GET UNDER SOME OF THESE DEEPER
THUNDERSTORMS. HAVE NOT MADE ANY ADJUSTMENTS TO THE FLASH FLOOD
WATCH THE ONLY THING IS THAT IT MIGHT NEED TO BE EXTENDED BUT WILL
ALLOW DAY SHIFT TO SEE HOW CONVECTION EVOLVES TODAY AND WHERE THE
HEAVIEST RAINFALL OCCURS. HAVE NOT MADE MANY CHANGES IN THE SHORT
TERM. 13/MH
LONG TERM...
THIS ACTIVE WET PATTERN CONTINUES IN THE LONG RANGE. EXPECT
ANOTHER ROUND OF RAIN FOR WEDNESDAY AND THURSDAY. MODELS INDICATE
A PRETTY WET FRIDAY AS WELL...IT IS POSSIBLE THAT THE FLASH FLOOD
WATCH THATS IN PLACE TODAY COULD BE IN PLACE THROUGH FRIDAY IF YOU
TAKE MODELS AT FACE VALUE. THERE WILL BE HIGH RAIN CHANCES THROUGH
AT LEAST SATURDAY. BOTH GFS AND ECMWF SHOW THE UPPER LEVEL
TROUGH/LOW FINALLY MOVING OUT LATE THIS WEEKEND...UNTIL THEN RAIN
WILL BE IN THE FORECAST. HAVE CONTINUED THE BLENDED APPROACH FROM
LAST PACKAGE. DIURNAL TEMPERATURE TRENDS TO CONTINUE WITH NOT MUCH MORE
THAN 10-15 DEGREE SPREAD. COULD SEE A LITTLE COOLER OVERNIGHT LOWS BEGINNING
SUNDAY IN THE NORTH IF SOME DRYING WORKS IN AFTER THE UPPER LOW
PULLS OUT ON SUNDAY INTO MONDAY. 13/MH
AVIATION...
THE TAFS ARE GOING TO BE HIGHLY DEPENDENT ON CONVECTIVE
COVERAGE AND TRENDS THROUGH AT LEAST 00Z. SOME EARLY DEVELOPMENTS
ALREADY IN PROXIMITY TO KHUM AND A LARGER CLUSTER OF SHOWERS
APPROACHING KBTR...LIKELY TO BRING VARABLE CIG HEIGHTS AND VSBY THIS
MORNING THOSE LOCATIONS. HRRR MODEL BLOSSOMS PRECIPITATION OVER MUCH
OF THE AREA TO IMPACT ALL TERMINALS PRIOR TO 18Z. 24/RR
MARINE...
A PROLONGED PERIOD OF ONSHORE FLOW IS EXPECTED TO PREVAIL THROUGH
THE WEEKEND...GENERALLY AT LIGHT TO MODERATE LEVELS. A LONG FETCHED
SITUATION FROM THE YUCATAN CHANNEL GENERATES A DEEP SWELL TRAIN ON
FRIDAY THAT SHOULD BRING SEAS CLOSE TO 6 FEET IN THE OPEN
WATERS...WITH SOME 8 FOOT RANDOM WAVES IN THE OUTER WATERS THAT MAY
REQUIRE A SMALL CRAFT ADVISORY AT SOME POINT FRIDAY INTO SATURDAY.
24/RR
DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE
ACTIVATION...NONE
ACTIVITIES...FLASH FLOOD WATCH.
MONITORING HEAVY RAINFALL/FLOODING POTENTIAL.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TONIGHT RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 77 65 77 66 / 80 40 60 40
BTR 77 66 79 67 / 80 40 60 40
ASD 78 67 79 68 / 80 40 60 40
MSY 78 68 79 69 / 80 40 60 40
GPT 77 69 77 70 / 70 40 60 40
PQL 79 68 79 69 / 70 40 60 50
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR LAZ040-046>050-
056>070-072.
GM...NONE.
MS...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR MSZ080>082.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
ISSUED BY NATIONAL WEATHER SERVICE FLAGSTAFF AZ
305 AM PDT TUE APR 14 2015
.SYNOPSIS...STRONG WINDS WILL CONTINUE TO SPREAD ACROSS THE ENTIRE
REGION TODAY AND WEDNESDAY. GUSTY NORTH WINDS WILL PERSIST DOWN
THE COLORADO RIVER MUCH OF THE WEEK. COOLER TEMPERATURES ARE
EXPECTED FOR THE MIDDLE OF THE WEEK FOLLOWED BY A REBOUND TO ABOVE
NORMAL TEMPERATURES OVER THE WEEKEND.
&&
.SHORT TERM...THROUGH WEDNESDAY AFTERNOON.
STRONG SHORTWAVE TROUGH WHICH WILL BE RESPONSIBLE FOR WIDESPREAD
WINDY CONDITIONS TODAY IS CURRENTLY MOVING ACROSS THE PACIFIC
NORTHWEST WITH ITS SOUTHERN EDGE DRAGGING ACROSS THE NORTHERN GREAT
BASIN BY LATER THIS MORNING. SO FAR WINDS ACROSS MOST OF OUR
OBSERVATION SITES IN THE SIERRA AND OWENS VALLEY HAVENT BEEN REAL
IMPRESSIVE BUT THE LATEST HRRR RUNS DO PICK UP THE WIND INTENSITY
CONSIDERABLY LATER THIS MORNING. STRONGEST WINDS LOOK TO ARRIVE
BETWEEN 9AM AND NOON AHEAD OF A STRONG COLD FRONT FOR THE SIERRA AND
OWENS VALLEY. AS THIS FRONT PASSES THROUGH LATER THIS MORNING WINDS
WILL SHIFT AROUND TO THE NORTHWEST AND REMAIN QUITE GUSTY FOR THE
REMAINDER OF THE AFTERNOON.
ELSEWHERE STRONG WINDS WILL OVERSPREAD MUCH OF NYE AND ESMERALDA
COUNTIES BEHIND THE COLD FRONT AND WILL BE QUITE STRONG. HIGH WIND
WARNINGS LOOK GOOD FOR THESE AREAS AND WE WILL NEED TO KEEP AN EYE
ON LINCOLN COUNTY AS WELL WHERE THE HRRR HAS PRETTY WIDESPREAD 25 TO
35 MPH SUSTAINED WINDS. AREAS OF BLOWING DUST WILL BE LIKELY WITH
ALL THIS WIND AS WELL. THIS FRONT WILL CONTINUE TO PROGRESS SOUTH
THROUGH THE AFTERNOON...REACHING THE LAS VEGAS VALLEY BY AROUND 5PM
AND OUR SOUTHERN ZONES BY 11PM. VERY STRONG WINDS CAN BE EXPECTED
IMMEDIATELY BEHIND THE FRONT BEFORE SLOWLY WEAKENING OVERNIGHT BUT
REMAINING GUSTY. STRONG WINDS WILL PERSIST ALL NIGHT AND CONTINUE
INTO WEDNESDAY FOR LOCATIONS ALONG THE COLORADO RIVER.
CURRENT WARNING AND ADVISORY PRODUCTS LOOK GOOD AND HAVE NOT MADE
ANY FURTHER ADJUSTMENTS TO THEM.
.LONG TERM...THURSDAY THROUGH SUNDAY.
CLOSED UPPER LOW WILL CONTINUE TO SPIN OVER THE FOUR CORNERS
THURSDAY INTO FRIDAY WITH HIGH PRESSURE SLOWLY BUILDING IN FROM THE
WEST. THIS WILL LEAVE OUR REGION UNDER A PERSISTENT NORTHERLY FLOW
WITH GUSTY WINDS PERSISTING ESPECIALLY DOWN THE COLORADO RIVER. THE
WINDS WILL EASE A BIT OVER THE WEEKEND AS THE LOW DRIFTS EAST AND
HIGH PRESSURE TRIES TO BUILD BACK INTO THE AREA. THIS WILL RESULT IN
A WARMING TREND THROUGH THE WEEKEND WITH TEMPERATURES RETURNING TO
ABOVE NORMAL LEVELS.
MEANWHILE A WEAK LOW PRESSURE TROUGH MAY DEVELOP OVER NORTHERN
CALIFORNIA AND DRIFT SOUTHWARD WHICH COULD RESULT IN JUST ENOUGH
MOISTURE AND INSTABILITY TO SPARK OFF A FEW CUMULUS BUILD UPS AND
ISOLATED SHOWERS OR THUNDERSTORMS ACROSS THE SIERRA. IVE ADDED A
SLIGHT CHANCE OF THUNDER TO THOSE AREAS SATURDAY THROUGH MONDAY.
OTHERWISE DRY CONDITIONS LOOK TO CONTINUE THROUGH EARLY NEXT WEEK.
&&
.AVIATION...FOR MCCARRAN...SOUTHWEST WINDS ARE EXPECTED TO INCREASE
DURING THE MORNING HOURS AS A COLD FRONT APPROACHES THE AREA. WINDS
WILL GENERALLY BE 10 TO 15 KTS WITH OCCASIONAL GUSTS TO AROUND 25
KTS AND THEN INCREASE TO AROUND 15 TO 20 KNOTS WITH GUSTS
APPROACHING 30 TO 35 KTS AFTER 18Z. AREAS OF BLOWING DUST ARE
POSSIBLE AROUND THE AIRPORT WITH VISIBILITY DROPPING AS LOW AS 5SM
AT TIMES. A COLD FRONT IS EXPECTED TO PUSH THROUGH THE VEGAS VALLEY
AROUND 00Z THIS EVENING WITH WINDS SHIFTING TO THE NORTHWEST. WIND
SPEEDS ARE STILL EXPECTED TO REMAIN IN THE 15-20 KT RANGE WITH GUSTS
UP TO 30KTS. WINDS WILL GRADUALLY DECREASE DURING THE OVERNIGHT
HORUS. MINIMAL CLOUD COVER IS EXPECTED.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SOUTHWEST WINDS ARE EXPECTED TO INCREASE ACROSS THE
REGION AHEAD OF A COLD FRONT THAT WILL MOVE THROUGH THE REGION
TODAY. WINDS AHEAD OF THE COLD FRONT ARE EXPECTED TO BE IN THE 15-20
KT RANGE WITH GUSTS BETWEEN 30-35 KTS. SOME LOCATIONS MAY SEE GUSTS
EXCEEDING 40KTS. THIS WILL CAUSE AREAS OF BLOWING DUST WHICH COULD
REDUCE VISIBILITY DOWN TO 3-5SM...MAINLY BETWEEN 17-23Z. THIS FRONT
IS FORECAST TO MOVE THROUGH NORTHERN INYO AND ESMERALDA COUNTIES
AROUND 18Z AND THEN PROGRESS SOUTH DURING THE AFTERNOON. THE FRONT
IS EXPECTED TO REACH SOUTHERN NEVADA AROUND 00Z AND CONTINUE TO MOVE
SOUTH EARLY THIS EVENING. WINDS BEHIND THE FRONT WILL TURN NORTHWEST
WITH WIND SPEEDS AROUND 15-20 KTS AND GUSTS BETWEEN 30-35 KTS WHILE
GRADUALLY DECREASING OVERNIGHT. A FEW SHOWERS WILL BE POSSIBLE OVER
CENTRAL NYE AND NORTHERN LINCOLN COUNTIES THIS AFTERNOON...OTHERWISE
MINIMAL CLOUD COVER IS EXPECTED.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED
TODAY. ANY SIGNIFICANT WEATHER SHOULD BE REPORTED ACCORDING TO
STANDARD OPERATING PROCEDURES.
&&
$$
OUTLER
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1106 AM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL EXIT NORTHEAST PENNSYLVANIA AND SOUTHEAST NEW
YORK EARLY THIS MORNING TAKING THE SHOWERS WITH IT. AFTER THIS
FRONT PASSES BY, HIGH PRESSURE WILL PUSH DOWN FROM CANADA WITH
FAIR WEATHER AND SEASONAL TEMPERATURES FOR THE REST OF TODAY
THROUGH THURSDAY. THE NEXT CHANCE FOR RAIN SHOWERS WILL COME ON
THURSDAY NIGHT AS A WARM FRONT APPROACHES THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED AT 11 AM... HIGH CLOUDS ARE STREAMING NORTHEAST ACROSS PA
AND SOUTHERN NY LATE THIS MORNING NORTH OF A STALLED FRONTAL
BOUNDARY OVER THE MID-ATLANTIC. THESE CLOUDS WILL PERSIST ACROSS
MUCH OF THE AREA SOUTH OF THE THRUWAY TODAY AND WILL ACT TO KEEP
TEMPERATURES DOWN SLIGHTLY OVER THE PREVIOUS FORECAST. HAVE
LOWERED MAX TEMPS BY A FEW DEGREES ESPECIALLY IN PA WHERE CLOUDS
WILL BE THICKEST. HIGHS SHOULD STILL REACH NEAR TO JUST ABOVE 60
IN MOST OF NORTHEAST PA AND SOUTHERN NY... WITH MID 60S IN SUNNIER
AREAS UP NEAR THE THRUWAY. PREVIOUS DISCUSSION IS BELOW.
RADARS SHOW A BAND OF SHOWERS OF RAIN FROM ABOUT UTICA TO
BINGHAMTON AND TOWANDA AT THIS TIME AND WORKING EAST AS THE UPPER
LEVEL WAVE MOVES INTO THE EASTERN GREAT LAKES. THIS WAVE HAS
PROVIDED THE IMPETUS TO PUSH A COLD FRONT INTO NY AND PA. HI RES
MODELS CONTINUE TO INDICATE THAT THIS BAND OF SHRA WILL CONTINUE
EASTWARD AND CLEAR THE POCONOS TO WRN CATSKILLS BY AROUND 12Z AS
THE UPPER WAVE AND COLD FRONT MOVE THRU. THERE WAS NO LIGHTNING
DETECTED AND SHOWALTER INDICES WERE ABOVE 0C SO NO THUNDER
IN GRIDS. THE HRRR IS QUICKEST IN MOVING PRECIP THRU NE PA/SERN NY
WITH THE HI RES ARW AND NMM HOLDING THE PRECIP BACK A COUPLE
HOURS LONGER. THE RAP REFLECTIVITY FIELDS SHOW THAT THE PRECIP
CLEARS THESE AREAS BY 12-13Z. SO I HAVE HELD ON TO SLGHT CHC AT
12Z IN THESE AREAS. REST OF FORECAST AREA WILL BE FREE OF PRECIP
BTWN 6Z AND 12Z.
AFTER THE PRECIP PASSES BY CLOUDS WILL CLEAR FOR A TIME THIS
MORNING. BUT COLD ADVECTION AT 850 MB AND SFC DEWPOINTS STILL IN
UPPER 30S SHUD LEAD TO SCT STRATOCUMULUS FORMING FOR A TIME BEFORE
ENUF DIURNAL MIXING TAKES PLACE BY MIDDAY TO MIX OUT THESE
CLOUDS. MODEL SOUNDINGS SUGGEST THIS AS WELL. THEN BY AFTERNOON
CIRRUS IN ADVANCE OF THE UPPER LEVEL LOW OVER TEXAS WILL ADVECT
NORTHEAST INTO THE UPPER CONFLUENT ZONE ALOFT WHICH CUTS ACRS
CENTRAL NY BY 18Z-21Z. SO WE EXPECT A SHIELD OF CIRRUS FROM SRN
NY ACROSS PA THIS AFTERNOON WHICH WILL BE THICK ENUF TO SPOIL A
MOSTLY SUNNY FORECAST. THESE CLOUDS WILL PUSH SOUTHEAST OF NE
PA/SERN NY THIS EVENING AS ANOTHER NRN BRANCH UPPER LEVEL SHORT
WAVE PUSHES SOUTHEAST FROM ONTARIO. SO... WE HAVE VARYING AMNTS
OF CLOUD COVER IN THE GRIDS FOR TODAY. NO POPS WARRANTING PRECIP
EXCEPT 12Z-14Z IN OUR FAR SE AND THESE ARE IN THE SLGHT CHC CAT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
AFTER CIRRUS SHIELD PUSHES SOUTHEAST OF NE PA AND SERN NY THIS
EVENING AN UPPER LEVEL WAVE WILL PUSH SOUTHEAST INTO NRN NEW
ENGLAND LATER TONIGHT AND WEDNESDAY WITH NY AND PA BEING ON THE
SUBSDC SIDE OF THIS TROUGH WITH THE UPPER RDG AXIS OVER THE ERN
LAKES. THIS WILL SUPPORT HIGH PRESSURE TO BUILD SOUTHWARD FROM
CANADA WITH A DRIER AIR AND SEASONAL TEMPS FOR TONIGHT...WED AND
WED NGT.
BY THURSDAY THE SFC HIGH SHIFTS OFF THE NEW ENGLAND COAST AND A
SRLY FLOW OF AIR WILL DEVELOP OVER NY AND PA WITH MID TO HI CLOUDS
SPREADING FROM SW TO NE ACRS C NY AND NE PA. LOOKING AT THE
SYNOPTIC MODELS IT LOOKS LIKE ANY PRECIP WILL HOLD OFF UNTIL AFTER
00Z FRI SO THU LOOKS DRY AND MILDER WITH SRLY WINDS.
FOR THURSDAY NIGHT...THE GFS...EURO...CMC AND UKMET ALL SHOW
DECENT LOW-LEVEL THETA-E ADVECTION ARND 850 MB WHICH WILL ALLOW
FOR DESTABLIZATION AND SHRA ACVTY TO WORK INTO NY AND NRN PA FROM
W TO E OVRNGT. IT LOOKS LIKE WRN AND CNTRL NY GET INTO SOME SHRA
ACVTY BTWN 00Z AND 06Z AND NE PA AND SERN NY AFTER 6Z SO HAVE
WORKED POP TIMING TO REFLECT THIS. SHOWALTER INDICES SUGGEST THE
AMS WILL BE STABLE ENUF SO NO MENTION OF THUNDER AT THIS POINT.
QPF AMNTS APPEARS TO BE ON THE ORDER OF ABT .25 INCHES WHICH WILL
NOT CAUSE ANY HYDRO ISSUES. THE NAM IS THE ODD MODEL OUT WITH MUCH
DRIER LL AIR TO START AND NOT ENUF MOISTURE ADVTN TO LEAD TO MUCH
PRECIP. SO WENT WITH GFS/EURO/CMC AND UKMET IDEAS AND HAVE CHC
POPS SHRA THU NGT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
LONGWAVE RIDGING IS FORECAST TO BUILD ACROSS THE EASTERN U.S.
EARLY IN THE LONG TERM PERIOD BEFORE THE PATTERN BECOMES A BIT
TRICKIER LATE IN THE PERIOD AS MODEL SOLUTIONS DIVERGE
SIGNIFICANTLY INTO NEXT WEEKEND.
QUIET WEATHER EXPECTED THUR INTO FRIDAY WITH NEAR TO SLIGHTLY ABOVE
NORMAL TEMPS. THE CHANCE OF SHOWERS INCREASES SAT INTO MONDAY AS
SHORTWAVE ENERGY ROUND THE UPPER RIDGE NEXT WEEKEND. THE EXTENT OF
LOWER HEIGHTS...WHICH WOULD SUPPORT A WETTER SOLUTION...IS IN
QUESTION...WITH THE GFS SYSTEM KEEPING A STRONGER RIDGE. THE ECMWF
BRINGS AN UPPER LOW EASTWARD OUT OF THE PLAINS INTO THE REGION.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
MUCH DRIER LL AIR BHD THE COLD FNT AND ASSOCIATED PCPN THIS MRNG
RESULTING IN VFR CONDS ALL STATIONS. XCPTN IS SOME GND FOG AT ELM
BRINGING IFR VSBYS...WHICH SHD LIFT OFF QUICKLY. XPCT VFR CONDS
THRU THE TAF PD AS A SFC HIPRES BLDS INTO THE REGION. WV MVG THRU
THE OH VLY WILL KEEP HI CLDS OVER THE AREA HWVR.
.OUTLOOK...
WED/THUR...VFR.
THU NGT-SAT...POSSIBLE RESTRICTIONS IN -SHRA.
&&
.FIRE WEATHER...
DRIER AIR BEHIND A COLD FRONTAL PASSAGE WILL LEAD TO RELATIVE
HUMIDITIES FALLING BELOW 30 PERCENT THIS AFTERNOON. WINDS LOOK TO
BE LESS THAN 20 MPH ACROSS CENTRAL NEW YORK AND NORTHEAST
PENNSYLVANIA. IN ADDITION THE RAIN SHOWERS FROM LAST NIGHT AND
EARLY THIS MORNING SHOULD KEEP FINE FUELS ABOVE 10 PERCENT MOST OF
THE DAY. THEREFORE FIRE CONDITIONS ARE NOT EXPECTED TO APPROACH RED
FLAG CONDITIONS TODAY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN/MSE
SHORT TERM...DJN
LONG TERM...
AVIATION...DGM
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
630 AM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL EXIT NORTHEAST PENNSYLVANIA AND SOUTHEAST NEW
YORK EARLY THIS MORNING TAKING THE SHOWERS WITH IT. AFTER THIS
FRONT PASSES BY, HIGH PRESSURE WILL PUSH DOWN FROM CANADA WITH
FAIR WEATHER AND SEASONAL TEMPERATURES FOR THE REST OF TODAY
THROUGH THURSDAY. THE NEXT CHANCE FOR RAIN SHOWERS WILL COME ON
THURSDAY NIGHT AS A WARM FRONT APPROACHES THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADARS SHOW A BAND OF SHOWERS OF RAIN FROM ABOUT UTICA TO
BINGHAMTON AND TOWANDA AT THIS TIME AND WORKING EAST AS THE UPPER
LEVEL WAVE MOVES INTO THE EASTERN GREAT LAKES. THIS WAVE HAS
PROVIDED THE IMPETUS TO PUSH A COLD FRONT INTO NY AND PA. HI RES
MODELS CONTINUE TO INDICATE THAT THIS BAND OF SHRA WILL CONTINUE
EASTWARD AND CLEAR THE POCONOS TO WRN CATSKILLS BY AROUND 12Z AS
THE UPPER WAVE AND COLD FRONT MOVE THRU. THERE WAS NO LIGHTNING
DETECTED AND SHOWALTER INDICES WERE ABOVE 0C SO NO THUNDER
IN GRIDS. THE HRRR IS QUICKEST IN MOVING PRECIP THRU NE PA/SERN NY
WITH THE HI RES ARW AND NMM HOLDING THE PRECIP BACK A COUPLE
HOURS LONGER. THE RAP REFLECTIVITY FIELDS SHOW THAT THE PRECIP
CLEARS THESE AREAS BY 12-13Z. SO I HAVE HELD ON TO SLGHT CHC AT
12Z IN THESE AREAS. REST OF FORECAST AREA WILL BE FREE OF PRECIP
BTWN 6Z AND 12Z.
AFTER THE PRECIP PASSES BY CLOUDS WILL CLEAR FOR A TIME THIS
MORNING. BUT COLD ADVECTION AT 850 MB AND SFC DEWPOINTS STILL IN
UPPER 30S SHUD LEAD TO SCT STRATOCUMULUS FORMING FOR A TIME BEFORE
ENUF DIURNAL MIXING TAKES PLACE BY MIDDAY TO MIX OUT THESE
CLOUDS. MODEL SOUNDINGS SUGGEST THIS AS WELL. THEN BY AFTERNOON
CIRRUS IN ADVANCE OF THE UPPER LEVEL LOW OVER TEXAS WILL ADVECT
NORTHEAST INTO THE UPPER CONFLUENT ZONE ALOFT WHICH CUTS ACRS
CENTRAL NY BY 18Z-21Z. SO WE EXPECT A SHIELD OF CIRRUS FROM SRN
NY ACROSS PA THIS AFTERNOON WHICH WILL BE THICK ENUF TO SPOIL A
MOSTLY SUNNY FORECAST. THESE CLOUDS WILL PUSH SOUTHEAST OF NE
PA/SERN NY THIS EVENING AS ANOTHER NRN BRANCH UPPER LEVEL SHORT
WAVE PUSHES SOUTHEAST FROM ONTARIO. SO... WE HAVE VARYING AMNTS
OF CLOUD COVER IN THE GRIDS FOR TODAY. NO POPS WARRANTING PRECIP
EXCEPT 12Z-14Z IN OUR FAR SE AND THESE ARE IN THE SLGHT CHC CAT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
AFTER CIRRUS SHIELD PUSHES SOUTHEAST OF NE PA AND SERN NY THIS
EVENING AN UPPER LEVEL WAVE WILL PUSH SOUTHEAST INTO NRN NEW
ENGLAND LATER TONIGHT AND WEDNESDAY WITH NY AND PA BEING ON THE
SUBSDC SIDE OF THIS TROUGH WITH THE UPPER RDG AXIS OVER THE ERN
LAKES. THIS WILL SUPPORT HIGH PRESSURE TO BUILD SOUTHWARD FROM
CANADA WITH A DRIER AIR AND SEASONAL TEMPS FOR TONIGHT...WED AND
WED NGT.
BY THURSDAY THE SFC HIGH SHIFTS OFF THE NEW ENGLAND COAST AND A
SRLY FLOW OF AIR WILL DEVELOP OVER NY AND PA WITH MID TO HI CLOUDS
SPREADING FROM SW TO NE ACRS C NY AND NE PA. LOOKING AT THE
SYNOPTIC MODELS IT LOOKS LIKE ANY PRECIP WILL HOLD OFF UNTIL AFTER
00Z FRI SO THU LOOKS DRY AND MILDER WITH SRLY WINDS.
FOR THURSDAY NIGHT...THE GFS...EURO...CMC AND UKMET ALL SHOW
DECENT LOW-LEVEL THETA-E ADVECTION ARND 850 MB WHICH WILL ALLOW
FOR DESTABLIZATION AND SHRA ACVTY TO WORK INTO NY AND NRN PA FROM
W TO E OVRNGT. IT LOOKS LIKE WRN AND CNTRL NY GET INTO SOME SHRA
ACVTY BTWN 00Z AND 06Z AND NE PA AND SERN NY AFTER 6Z SO HAVE
WORKED POP TIMING TO REFLECT THIS. SHOWALTER INDICES SUGGEST THE
AMS WILL BE STABLE ENUF SO NO MENTION OF THUNDER AT THIS POINT.
QPF AMNTS APPEARS TO BE ON THE ORDER OF ABT .25 INCHES WHICH WILL
NOT CAUSE ANY HYDRO ISSUES. THE NAM IS THE ODD MODEL OUT WITH MUCH
DRIER LL AIR TO START AND NOT ENUF MOISTURE ADVTN TO LEAD TO MUCH
PRECIP. SO WENT WITH GFS/EURO/CMC AND UKMET IDEAS AND HAVE CHC
POPS SHRA THU NGT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
LONGWAVE RIDGING IS FORECAST TO BUILD ACROSS THE EASTERN U.S.
EARLY IN THE LONG TERM PERIOD BEFORE THE PATTERN BECOMES A BIT
TRICKIER LATE IN THE PERIOD AS MODEL SOLUTIONS DIVERGE
SIGNIFICANTLY INTO NEXT WEEKEND.
QUIET WEATHER EXPECTED THUR INTO FRIDAY WITH NEAR TO SLIGHTLY ABOVE
NORMAL TEMPS. THE CHANCE OF SHOWERS INCREASES SAT INTO MONDAY AS
SHORTWAVE ENERGY ROUND THE UPPER RIDGE NEXT WEEKEND. THE EXTENT OF
LOWER HEIGHTS...WHICH WOULD SUPPORT A WETTER SOLUTION...IS IN
QUESTION...WITH THE GFS SYSTEM KEEPING A STRONGER RIDGE. THE ECMWF
BRINGS AN UPPER LOW EASTWARD OUT OF THE PLAINS INTO THE REGION.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
MUCH DRIER LL AIR BHD THE COLD FNT AND ASSOCIATED PCPN THIS MRNG
RESULTING IN VFR CONDS ALL STATIONS. XCPTN IS SOME GND FOG AT ELM
BRINGING IFR VSBYS...WHICH SHD LIFT OFF QUICKLY. XPCT VFR CONDS
THRU THE TAF PD AS A SFC HIPRES BLDS INTO THE REGION. WV MVG THRU
THE OH VLY WILL KEEP HI CLDS OVER THE AREA HWVR.
.OUTLOOK...
WED/THUR...VFR.
THU NGT-SAT...POSSIBLE RESTRICTIONS IN -SHRA.
&&
.FIRE WEATHER...
DRIER AIR BEHIND A COLD FRONTAL PASSAGE WILL LEAD TO RELATIVE
HUMIDITIES FALLING BELOW 30 PERCENT THIS AFTERNOON. WINDS LOOK TO
BE LESS THAN 20 MPH ACROSS CENTRAL NEW YORK AND NORTHEAST
PENNSYLVANIA. IN ADDITION THE RAIN SHOWERS FROM LAST NIGHT AND
EARLY THIS MORNING SHOULD KEEP FINE FUELS ABOVE 10 PERCENT MOST OF
THE DAY. THEREFORE FIRE CONDITIONS ARE NOT EXPECTED TO APPROACH RED
FLAG CONDITIONS TODAY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...
AVIATION...DGM
FIRE WEATHER...DJN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1130 AM EDT TUE APR 14 2015
.SYNOPSIS...
UNSETTLED CONDITIONS WILL PERSIST TODAY AS A SERIES OF WEAK
DISTURBANCES MOVE ACROSS. A COLD FRONT WILL CROSS THE AREA EARLY
WEDNESDAY MORNING...STALLING TO OUR SOUTH ON THURSDAY. LOW
PRESSURE MAY DEVELOP ALONG THE FRONT THURSDAY INTO FRIDAY..LIFTING
NORTH OF THE AREA SATURDAY. A COLD FRONT WILL MOVE ACROSS THE
CAROLINAS FROM THE WEST LATE SATURDAY. HIGH PRESSURE WILL BUILD IN
FROM THE WEST SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...ENTRENCHED IN WARM AND MOIST AIR MASS
TODAY AS COLD FRONT MAKES ITS WAY SOUTH INTO NORTH CAROLINA.
DEWPOINTS IN THE MID 60S TODAY AND TEMPS IN THE MID 70S WITH
EXTENSIVE CLOUD COVER THIS MORNING...BUT SHOULD RISE A FEW MORE
DEGREES TO BRING TEMPS AROUND 80 MOST PLACES. MAY SEE SOME BRIEF
BREAKS IN CLOUDS THIS AFTERNOON WHICH WILL HELP PROPEL TEMPS UP A
LITTLE FURTHER. DEEP MOISTURE THROUGH THIS AFTERNOON WITH PCP
WATER VALUES UP CLOSE TO 2 INCHES AND SOUNDING PARAMETERS ALL
POINTING TO POTENTIAL FOR TSTMS. THE PRIMARY FOCUS WOULD BE
FURTHER NW INTO CENTRAL CAROLINAS AS WAVE OF LOW PRESSURE MOVES UP
THROUGH THE TENNESSEE VALLEY TOWARD THE NORTHEAST. A SHORTWAVE
MOVING THROUGH WILL ALSO HELP TO ENHANCE ANY CONVECTION THROUGH
THIS AFTERNOON.
FOR OUR LOCAL AREA...MODELS SHOW DRIER AIR MAKING ITS WAY UP INTO
THE AREA AS WINDS SHIFT TO A MORE SW-W THROUGH THIS AFTERNOON.
GFS SHOWS A DROP IN PCP WATER DOWN TO 1.5 INCHES BY THIS EVENING.
HRRR SHOWS SHOWERS AROUND THIS MORNING MOVING OFF TO THE NORTHEAST
LEAVING ONLY ISOLATED SHWRS OVER LOCAL AREA. IF SUN BREAKS OUT AT
ALL...IT WILL ACT TO DESTABILIZE THE ATMOSPHERE FURTHER AND COULD
PRODUCE SOME DIFFERENTIAL HEATING BUT OVERALL CLOUD COVER WILL
LIMIT SEA BREEZE STRENGTH THROUGH THIS AFTERNOON. POTENTIAL WILL
EXIST ESPECIALLY THROUGH THIS AFTERNOON TO SEE SOME ISOLATED
STRONGER STORMS. SPC HAS NORTHWEST PORTIONS OF FORECAST AREA IN
MARGINAL RISK WITH STRONGER WIND THREAT...BUT MAIN THREAT AREA
SHOULD REMAIN FARTHER TO THE NORTH AND WEST.
COLD FRONT WILL DROP SOUTH THROUGH TONIGHT WITH WINDS SHIFTING
AROUND FURTHER BECOMING NORTH BEHIND FRONT. SHOULD SEE ANOTHER
POTENTIAL FOR INCREASED SHOWER ACTIVITY AS COLD FRONT MOVES
THROUGH AREA OVERNIGHT. COOLER AIR WILL MAKE ITS WAY IN BEHIND
FRONT WHICH SHOULD BE SOUTH OF AREA BY MORNING. TEMPS MAY DROP
BELOW 60 BY DAYBREAK.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM TUESDAY...FORECAST REMAINS ONE OF LOWER CONFIDENCE AS A
MOISTURE LADEN SOUTHWEST FLOW CONTINUES AT THE MID LEVELS THROUGH
THE PERIOD. AT THE SURFACE A BACKDOOR FRONT WILL PUSH ACROSS THE
AREA DURING THE MORNING HOURS WEDNESDAY. SEVERAL WEAK SHORTWAVES
WILL MOVE THROUGH THE FLOW AND MODELS HAVE BEEN HAVING DIFFICULTY
WITH THE TIMING AND PLACEMENT OF THESE FEATURES. IT SEEMS TO
CHANGE DRAMATICALLY FROM CYCLE TO CYCLE. PRUDENCE CALLS FOR
KEEPING POPS IN THE FORECAST THROUGHOUT WITH AT LEAST SOME
VARIATION IN VALUES. THE LATEST BEST FORCING APPEARS TO OCCUR
THURSDAY AND I HAVE ELEVATED TO LIKELY IN SOME AREAS WITH HIGH
CHANCE ELSEWHERE. AIRMASS IN THE WAKE OF THE FRONT IS COOLER AND
HIGHS WILL BE CONFINED TO THE 60S BOTH DAYS AND OVERNIGHT LOWS IN
THE 50S SHOWING LITTLE DIURNAL RANGE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 330 AM TUESDAY...500MB PATTERN WILL FEATURE THE CLOSED LOW
ACROSS THE SOUTHWEST FINALLY GETTING KICKED OUT AND WEAKENING AS
IT MOVES TO THE EAST. IN FACT THE TROUGH WEAKENS SO MUCH A
SOUTHWEST FLOW WILL CONTINUE UNABATED THROUGH THE PERIOD. THIS
ALLOWS A BAROCLINIC ZONE TO REMAIN DRAPED ACROSS THE SOUTHEAST.
THIS SCENARIO IS BASED PRIMARILY ON THE GFS SOLUTIONS. THE ECMWF
PAINTS A DIFFERENT SCENARIO WITH THE LOW HOLDING BACK WITH THE
PERSISTENT WET SOUTHWEST PERSISTING. FOR THIS REASON I AM HOLDING
ON TO SLIGHT CHANCE POPS FOR SUNDAY WITH CHANCE EITHER SIDE OF
THIS. HIGHS WILL GENERALLY BE 75-80 DEGREES WITH LOWS IN THE LOWER
TO MIDDLE 60S.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
AS OF 12Z...QUITE A BIT OF UNCERTAINTY WITH RESPECT TO TIMING OF THE
CONVECTION TODAY...SAFE TO SAY THERE WILL BE A LOT OF
CONVECTION...ESPECIALLY NEAR THE COAST THIS MORNING. THE HRRR HAS A
REASONABLE HANDLE ON THINGS WITH CONVECTION NEAR THE COAST THIS
MORNING...FOLLOWED BY WIDESPREAD CONVECTION CWA WIDE THIS AFTERNOON.
ALL OF THIS ACTIVITY IS COURTESY OF LOW PRESSURE CENTERED WEST OF
THE REGION WITH SPOKES OF VORTICITY ROTATING EAST OF THE LOW. THE
LAST VORT WILL MOVE NORTHEAST AND OUT OF THE REGION LATE THIS
AFTERNOON...FOLLOWED BY CLEARING SKIES. TONIGHT...STRATUS WILL AGAIN
SET UP...WITH WINDS SHIFTING TO THE NORTH LATE IN THE FORECAST
PERIOD AS A BACK DOOR FRONT DROPS IN.
EXTENDED OUTLOOK...WED...A CHANCE OF MVFR IN THUNDERSTORMS.
MVFR/SHOWERS THURS THROUGH FRI. VFR SAT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...SOUTH TO SW WINDS WILL CONTINUE TODAY
AND TONIGHT IN ADVANCE OF A SLOW MOVING COLD FRONT. WINDS WILL
CONTINUE IN THE GENERAL 10 TO 15 KT RANGE...WITH SEAS RANGING FROM
3 TO 5 FT MOST PLACES. HIGHEST PORTION OF THE SEA HEIGHT RANGE
WILL BE OVER OUR NC WATERS...WITH SEAS CLOSER TO 3 FT FURTHER
SOUTH.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM TUESDAY...A NORTHEAST FLOW WILL BE IN THE INITIAL STAGES
EARLY WEDNESDAY AS A WEDGE PATTERN DEVELOPS. SPEEDS INCREASE FROM
AROUND TEN KNOTS EARLY TO A RANGE OF 20-15 KNOTS BY LATE IN THE
EVENING. THEY REMAIN IN THIS RANGE UNTIL LATER THURSDAY AFTERNOON WHEN
THEY BEGIN THEIR STEADY DECLINE TO TEN KNOTS OR LESS BY FRIDAY
MORNING. WITH THE STRONGER WINDS...SEAS WILL WORK UP TO SMALL
CRAFT CRITERIA BY WEDNESDAY EVENING AND REMAIN SO UNTIL LATE
THURSDAY AFTERNOON.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 330 AM TUESDAY...A RELATIVELY LIGHT FLOW IS EXPECTED FROM THE
EAST/SOUTHEAST FRIDAY ON THE ORDER OF 10-15 KNOTS. THE FLOW WILL
VEER TO SOUTHWEST SATURDAY AND PICK UP STEAM A BIT AS A COLD FRONT
MOVES CLOSER FROM THE WEST. NOT A LOT OF CONFIDENCE IN THIS FORECAST
HOWEVER AS MODELS HAVE BEEN STRUGGLING WITH THE FEATURES. SEAS WILL
BE 1-3 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...RGZ
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL
MARINE...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
643 AM EDT TUE APR 14 2015
.SYNOPSIS...
UNSETTLED CONDITIONS WILL PERSIST TODAY AS A SERIES OF WEAK
DISTURBANCES MOVE ACROSS. A COLD FRONT WILL CROSS THE AREA EARLY
WEDNESDAY MORNING...STALLING TO OUR SOUTH ON THURSDAY. LOW
PRESSURE MAY DEVELOP ALONG THE FRONT THURSDAY INTO FRIDAY..LIFTING
NORTH OF THE AREA SATURDAY. A COLD FRONT WILL MOVE ACROSS THE
CAROLINAS FROM THE WEST LATE SATURDAY. HIGH PRESSURE WILL BUILD IN
FROM THE WEST SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
UNSEASONABLE WARMTH TODAY AND TONIGHT AS SOUTHERLY FLOW CONTINUES
IN ADVANCE OF A SLOW- MOVING COLD FRONT. EXTENSIVE CLOUDINESS AND
THE GOOD LIKELIHOOD OF SHOWERS WITH ISOLATED THUNDERSTORMS WILL
ALSO MARK THE NEAR TERM AS A DEEP MOISTURE-TAP OFF THE GULF OF
MEXICO AND SOUTH ATLANTIC CONTINUES. MODEL SOUNDINGS SHOW AMPLE
MOISTURE WITH P/W VALUES VARYING BETWEEN 1.5 AND 2.0 INCHES TODAY
AND TONIGHT...WITH DEWPOINTS WELL UP IN THE 60S DURING THE DAYTIME
AND EVENING HOURS.
AN APPROACHING UPPER DISTURBANCE WILL ENHANCE PRECIP CHANCES DURING
THE DAYLIGHT HOURS...BUT TIMING OF THIS FEATURE AMONGST VARIOUS
GUIDANCE IS VARIABLE AND MAKES IT HARD TO PIN DOWN WHEN THE BEST
CHANCES FOR CONVECTION TO OCCUR. FOR THE OVERNIGHT HOURS GUIDANCE IS
IN AGREEMENT ON A DRY SLOT MOVING THROUGH IN ASSOCIATION WITH THE
IMPENDING COLD FRONT. A CONSENSUS OF GUIDANCE HAS THE FRONT
BISECTING THE CWA FROM ROUGHLY EAST TO WEST BY DAYBREAK ON WEDNESDAY.
TEMPERATURES WILL BE WELL ABOVE NORMAL TODAY...WITH HIGHS IN THE
LOWER TO MID 80S AND LOWS IN THE 60S.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM TUESDAY...FORECAST REMAINS ONE OF LOWER CONFIDENCE AS A
MOISTURE LADEN SOUTHWEST FLOW CONTINUES AT THE MID LEVELS THROUGH
THE PERIOD. AT THE SURFACE A BACKDOOR FRONT WILL PUSH ACROSS THE
AREA DURING THE MORNING HOURS WEDNESDAY. SEVERAL WEAK SHORTWAVES
WILL MOVE THROUGH THE FLOW AND MODELS HAVE BEEN HAVING DIFFICULTY
WITH THE TIMING AND PLACEMENT OF THESE FEATURES. IT SEEMS TO
CHANGE DRAMATICALLY FROM CYCLE TO CYCLE. PRUDENCE CALLS FOR
KEEPING POPS IN THE FORECAST THROUGHOUT WITH AT LEAST SOME
VARIATION IN VALUES. THE LATEST BEST FORCING APPEARS TO OCCUR
THURSDAY AND I HAVE ELEVATED TO LIKELY IN SOME AREAS WITH HIGH
CHANCE ELSEWHERE. AIRMASS IN THE WAKE OF THE FRONT IS COOLER AND
HIGHS WILL BE CONFINED TO THE 60S BOTH DAYS AND OVERNIGHT LOWS IN
THE 50S SHOWING LITTLE DIURNAL RANGE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 330 AM TUESDAY...500MB PATTERN WILL FEATURE THE CLOSED LOW
ACROSS THE SOUTHWEST FINALLY GETTING KICKED OUT AND WEAKENING AS
IT MOVES TO THE EAST. IN FACT THE TROUGH WEAKENS SO MUCH A
SOUTHWEST FLOW WILL CONTINUE UNABATED THROUGH THE PERIOD. THIS
ALLOWS A BAROCLINIC ZONE TO REMAIN DRAPED ACROSS THE SOUTHEAST.
THIS SCENARIO IS BASED PRIMARILY ON THE GFS SOLUTIONS. THE ECMWF
PAINTS A DIFFERENT SCENARIO WITH THE LOW HOLDING BACK WITH THE
PERSISTENT WET SOUTHWEST PERSISTING. FOR THIS REASON I AM HOLDING
ON TO SLIGHT CHANCE POPS FOR SUNDAY WITH CHANCE EITHER SIDE OF
THIS. HIGHS WILL GENERALLY BE 75-80 DEGREES WITH LOWS IN THE LOWER
TO MIDDLE 60S.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 12Z...QUITE A BIT OF UNCERTAINTY WITH RESPECT TO TIMING OF THE
CONVECTION TODAY...SAFE TO SAY THERE WILL BE A LOT OF
CONVECTION...ESPECIALLY NEAR THE COAST THIS MORNING. THE HRRR HAS A
REASONABLE HANDLE ON THINGS WITH CONVECTION NEAR THE COAST THIS
MORNING...FOLLOWED BY WIDESPREAD CONVECTION CWA WIDE THIS AFTERNOON.
ALL OF THIS ACTIVITY IS COURTESY OF LOW PRESSURE CENTERED WEST OF
THE REGION WITH SPOKES OF VORTICITY ROTATING EAST OF THE LOW. THE
LAST VORT WILL MOVE NORTHEAST AND OUT OF THE REGION LATE THIS
AFTERNOON...FOLLOWED BY CLEARING SKIES. TONIGHT...STRATUS WILL AGAIN
SET UP...WITH WINDS SHIFTING TO THE NORTH LATE IN THE FORECAST
PERIOD AS A BACK DOOR FRONT DROPS IN.
EXTENDED OUTLOOK...WED...A CHANCE OF MVFR IN THUNDERSTORMS.
MVFR/SHOWERS THURS THROUGH FRI. VFR SAT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:
SOUTH TO SW WINDS WILL CONTINUE TODAY AND TONIGHT IN ADVANCE OF A
SLOW MOVING COLD FRONT. WINDS WILL CONTINUE IN THE GENERAL 10 TO
15 KT RANGE...WITH SEAS RANGING FROM 3 TO 5 FT MOST PLACES.
HIGHEST PORTION OF THE SEA HEIGHT RANGE WILL BE OVER OUR NC
WATERS...WITH SEAS CLOSER TO 3 FT FURTHER SOUTH.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM TUESDAY...A NORTHEAST FLOW WILL BE IN THE INITIAL STAGES
EARLY WEDNESDAY AS A WEDGE PATTERN DEVELOPS. SPEEDS INCREASE FROM
AROUND TEN KNOTS EARLY TO A RANGE OF 20-15 KNOTS BY LATE IN THE
EVENING. THEY REMAIN IN THIS RANGE UNTIL LATER THURSDAY AFTERNOON WHEN
THEY BEGIN THEIR STEADY DECLINE TO TEN KNOTS OR LESS BY FRIDAY
MORNING. WITH THE STRONGER WINDS...SEAS WILL WORK UP TO SMALL
CRAFT CRITERIA BY WEDNESDAY EVENING AND REMAIN SO UNTIL LATE
THURSDAY AFTERNOON.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 330 AM TUESDAY...A RELATIVELY LIGHT FLOW IS EXPECTED FROM THE
EAST/SOUTHEAST FRIDAY ON THE ORDER OF 10-15 KNOTS. THE FLOW WILL
VEER TO SOUTHWEST SATURDAY AND PICK UP STEAM A BIT AS A COLD FRONT
MOVES CLOSER FROM THE WEST. NOT A LOT OF CONFIDENCE IN THIS FORECAST
HOWEVER AS MODELS HAVE BEEN STRUGGLING WITH THE FEATURES. SEAS WILL
BE 1-3 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...REK
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL
MARINE...SHK
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
619 AM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND MOVE
OFFSHORE LATE TONIGHT. THE FRONT WILL THEN BECOME STATIONARY OVER
THE SOUTHEAST STATES FOR SEVERAL DAYS. ANOTHER COLD FRONT WILL
MOVE THROUGH FRIDAY NIGHT. HIGH PRESSURE WILL PASS TO THE NORTH
SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 615 AM TUESDAY...PRECIPITATION HAS BEEN VERY SLOW TO IMPACT
MOST OF OUR CWA WITH JUST A FEW LIGHT SHOWERS OR SPRINKLES ALONG
THE COAST THUS FAR. HEAVY RAINFALL LOOKS TO REMAIN OFFSHORE THIS
MORNING. LATEST 3KM HRRR HAS A DECENT HANDLE ON PRECIP PLACEMENT
AND SHOWS ACTIVITY RAMPING UP IN THE AFTERNOON. THE GFS/ECMWF DO
NOT SHOW THE PRONOUNCED DRY SLOT FROM EARLIER AND HAVE THUS UPPED
POPS BACK TO LIKELY STARTING AROUND NOON INTO LATE IN THE DAY.
HAVE GONE A FEW DEGREES BELOW GUIDANCE MAX TEMPERATURES TODAY
GIVEN THE CLOUD COVER AND PRECIPITATION...WITH HIGHS IN THE
MID/UPPER 70S INLAND AND UPPER 60S/LOWER 70S BEACHES. SPC HAS
PORTIONS OF THE AREA IN A MARGINAL THREAT FOR SEVERE WEATHER. MOST
OF THE INSTABILITY WILL BE OFFSHORE THIS MORNING...WITH MOST
INDICES INLAND THIS AFTERNOON...BUT GIVEN THE CLOUD
COVER/PRECIPITATION...DO NOT EXPECT MUCH OF A SEVERE THREAT TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
AS OF 340 AM TUESDAY...DIFFICULT TO TIME VARIOUS WAVES OF LOW
PRESSURE AND MID-LEVEL ENERGY MOVING THROUGH THE FAST SOUTHWEST
FLOW ALOFT. THINK RAIN WILL INCREASE IN INTENSITY AND COVERAGE
AGAIN FROM THE EARLY EVENING THROUGH ABOUT MIDNIGHT...THEN
COVERAGE WANES A BIT OVERNIGHT. THIS IS INDICATED IN POPS GOING
FROM LIKELY EARLY TO HIGH CHANCE LATE TONIGHT. GOOD AGREEMENT IN
GUIDANCE SHOWING MINIMUM TEMPS TONIGHT UPPER 50S TO LOWER 60S.
COLD FRONT CROSSES THE AREA AND MOVES OFFSHORE BETWEEN ROUGHLY 06Z
AND 09Z...ENDING THE THREAT OF ANY ELEVATED CONVECTION.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AN ACTIVE SOUTHERN JET STREAM AND INFLOW OF DEEP GULF MOISTURE WILL
LEAD TO UNSETTLED WEATHER THRU MUCH OF THIS FORECAST PERIOD WITH
POSSIBLE LOCALLY HEAVY RAIN AT TIMES. HOWEVER CONFIDENCE VERY LOW IN
FORECAST SPECIFICS ESPECIALLY AT LONGER RANGES GIVEN POOR MODEL
AGREEMENT AND LACK OF RUN TO RUN MODEL CONSISTENCY.
WED AND WED NIGHT...POSSIBLY DRIER THIS PERIOD ESPECIALLY NORTHERN
TIER...HOWEVER MODELS ARE TRENDING A BIT WETTER S AND INLAND. HIGH
PRES WILL BUILD IN FROM THE N WED AND BEGIN TO SHIFT OFFSHORE WED
NIGHT. DRIER AIR WILL TRY TO SPREAD IN FROM THE N WED...HOWEVER
MOISTURE WILL LINGER S AND W AND WITH WEAK IMPULSES CROSSING ALOFT
WILL CONT TO HAVE THREAT OF PRECIP WITH CHANCE POPS TO SOUTH AND
SLIGHT CHANCE NORTH WED AND WED NIGHT. COOL HIGHS WED IN THE 60S
WITH 50S WED NIGHT.
THU THROUGH SUNDAY...MOISTURE WILL INCREASE AGAIN THU WITH SCT SHRA
DEVELOPING AS LOW PRES FORMS TO THE S. THE LOW WILL LINGER NEAR THE
CST THROUGH FRIDAY WITH CONT THREAT OF SHRA...AGAIN SIGNIFICANT
MODELS DIFFERENCES SO MAINTAINED FORECAST CONTINUITY FOR NOW. A COLD
FRONT WILL APPROACH FRI NIGHT AND CROSS LATE SAT OR SAT NIGHT WITH
SCT SHRA. CONTINUED ISOLD TSRA FRI AFTERNOON AND AGAIN SAT AS WEAK
INSTABILITY DEVELOPS OVER REGION. LONGER RANGE MODELS NOW TRYING TO
PUSH DEEP MOISTURE BACK INTO THE FORECAST AREA ON SUNDAY BUT WILL
KEEP JUST SLIGHT CHANCE POPS AWAITING BETTER MODEL CONSISTENCY.
HIGHS ONLY IN THE 60S IN COOL NE FLOW THURSDAY THEN WARMING INTO THE
70S/NEAR SEASONAL NORMS THRU THE REST OF THE PERIOD...AS USUAL FOR
THIS TIME OF YEAR BEACHES WILL BE A BIT COOLER. LOWS 50S TO LOWER
60S.
MODELS BEGINNING TO TREND DRIER MONDAY AS DEEPER MOISTURE SHIFTS
OFFSHORE BUT WILL CONTINUE WITH LOW CHANCE POPS AHEAD OF POSSIBLE
COLD FRONTAL PASSAGE. HIGHS IN THE LOWER/MID 70S INLAND TO 60S
CST.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 12Z WEDNESDAY/...
AS OF 630 AM TUESDAY...DIFFICULT AVIATION FORECAST IN TERM OF
TIMING WAVES OF PRECIPITATION AND LOWER CLOUDS. ALL TAF SITES
CURRENTLY AT MVFR AND WILL NOW KEEP THEM IN THAT RANGE THROUGH
MOST OF THE DAY AS STEADIER RAINFALL ARRIVES BY THE AFTERNOON.
CEILINGS GO UP A BIT AROUND 00Z...BUT ALL GUIDANCE SHOWS
WIDESPREAD IFR BEHIND COLD FRONT AS NORTHEAST WINDS DEVELOP WITH
PLENTIFUL LOW-LEVEL MOISTURE.
LONG TERM /WEDNESDAY THROUGH SATURDAY/...
REDUCED FLIGHT CATEGORIES MAY CONTINUE EARLY WED BEFORE DRIER AIR
WORKS IN AND SHOULD SLOWLY SEE LOW CLOUDS SCOUR OUT HOWEVER SRN TIER
MAY HOLD ON TO SOME SUB VFR CONDITIONS. SCT SHRA EXPECTED TO DEVELOP
THU AND CONT INTO FRI WITH PERIODS OF SUB VFR LIKELY FROM TIME TO
TIME. COLD FRONT WILL APPROACH SAT WITH AGAIN SCT SHRA/POSS TSRA AND
BRIEF PERIODS OF SUB VFR EXPECTED.
&&
.MARINE...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 620 AM TUESDAY...SE/S WINDS ACROSS THE COASTAL WATERS AT 10
KNOTS OR LESS...EXCEPT SOME GUSTS INTO THE MID/UPPER TEENS AT
DIAMOND BUOY. SEAS RUNNING 3 TO 4 FEET WITH 5 FEET AT DIAMOND. NO
BIG CHANGES TO THE CURRENT MARINE FORECAST AS WINDS BECOME MORE
SOUTHWEST AND INCREASE TO A SOLID 15 TO 20 KNOTS OVER THE
CENTRAL WATERS LATER TODAY AND TONIGHT AS LOCAL NWPS/SWAN BUILDS
SEAS TO 3 TO 5 FEET OVER ALL COASTAL WATERS...ESPECIALLY BEHIND
THE FRONT EARLY WEDNESDAY MORNING.
LONG TERM /WEDNESDAY THROUGH SATURDAY/...
NNE WINDS WILL INCREASE TO 20 TO 25 KTS WED AS HIGH BUILDS IN FROM
THE N... SCA LIKELY LATER TUE NIGHT THROUGH WED AS SEAS BUILD TO 5
TO 8 FT. THE HIGH WILL SLIDE OFFSHORE THU WITH WEAK LOW DEVELOPING
TO THE S...WINDS WILL BECOME EAST AND CONT GUSTY MAINLY 15 TO 25 KTS
WITH SEAS REMAINING ELEVATED AT 6 TO 9 FT. LOW PRES MOVES UP THE
COAST FRIDAY. MODELS DIFFER ON TRACK AND INTENSITY BUT A CONCENSUS
FORECAST WOULD SUGGEST THE LOW MOVING NE OFF THE NC COAST WITH SLOW
DEEPENING. THIS SOLUTION WOULD MAINTAIN MODERATE E/NE WINDS AND ONLY
SLOWLY SUBSIDING SEAS THRU THE END OF THE WEEK. WINDS BECOME NW
BEHIND THE EXITING LOW FRIDAY NIGHT AND SATURDAY WITH CONTINUED
SLOWLY FALLING SEA HEIGHTS TO BELOW SMALL CRAFT ADVISORY LEVELS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM WEDNESDAY TO 9 AM EDT SATURDAY
FOR AMZ150-152-154.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...BTC
AVIATION...BTC/CTC
MARINE...BTC/CTC
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
913 AM EDT TUE APR 14 2015
.SYNOPSIS...
HIGH PRESSURE IN THE GREAT LAKES AND LOW PRESSURE IN THE TENNESSEE
VALLEY WILL HAVE A COOL AIRMASS OVER THE OHIO VALLEY WITH RAIN ENDING
OVER THE SOUTHERN OHIO VALLEY THIS MORNING. THE HIGH WILL CONTINUE
TO PUSH DRIER AND SOMEWHAT COOL AIR TO THE REGION THROUGH
WEDNESDAY. A SURFACE TROUGH WILL NOSE NORTHEAST INTO OHIO ON
THURSDAY AND BRING AN INCREASED THREAT FOR MORE SHOWERS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SURFACE LOW PRESSURE SYSTEM OVER THE CENTRAL TENNESSEE VALLEY
WILL PUSH OFF TO THE EAST THROUGH THIS AFTERNOON. WIDESPREAD RAIN
ASSOCIATED WITH THIS CONTINUES TO AFFECT PRIMARILY AREAS TO OUR
SOUTH...BUT THERE HAS BEEN AN EVER SO SLIGHT NORTHWARD PUSH TO
THE PCPN SHIELD IN THE LAST FEW HOURS. THE LATEST RAP SEEMS TO
HAVE THE BEST HANDLE ON THE SITUATION AND IS HANGING ON TO A WEAK
850-700 MB DEFORMATION AXIS ACROSS OUR SOUTHERN AREAS THROUGH
EARLY AFTERNOON. BASED ON THIS AND RADAR TRENDS...WILL NUDGE UP
POPS ACROSS OUR FAR SOUTH THROUGH THE REST OF THE MORNING. AS THE
LOW BEGINS TO PUSH OFF TO THE EAST...PCPN SHOULD TAPER OFF
THROUGH THIS AFTERNOON. EXPECT COOLEST TEMPS TODAY ACROSS OUR FAR
SOUTH DUE TO THE CLOUDS AND PCPN WITH HIGHS. GENERALLY EXPECT HIGHS
IN THE LOW TO MID 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
NORTHEAST WIND WILL CONTINUE TO BRING IN DRIER AIR TO THE OHIO
VALLEY ALONG WITH A GENERALLY MUTED AND STAGNANT TEMPERATURE
CHANGE OVER THE NEXT FEW DAYS. READINGS SHOULD TOP OUT IN THE MID
60S WED AND THURS AND WARM TO THE UPPER 60S FRIDAY. OVERNIGHT LOWS
WILL DIP TO THE LOW AND MID 40S TONIGHT AND SLOWLY RISE TO THE
LOWER 50S THURSDAY NIGHT.
AN INVERTED TROUGH WILL NOSE NORTHEAST INTO OHIO WED NIGHT AND SEE
INCREASED SHOWER ACTIVITY WITH IT. MODELS ARE DISJOINTED IN THE
AREAL COVERAGE OF QPF THURSDAY AND OVERNIGHT...AND THE INVERTED
TROUGH TYPICALLY IS NOT ENOUGH ON ITS OWN TO BRING WIDESPREAD
SHOWERS. H5 RIDGE IN PLACE WEDNESDAY WILL BREAK DOWN AND MOVE EAST
THURSDAY WITH A LOBE OF VORTICITY IN A VERY WEAK S/W PASSING OVER
THE REGION AT 0Z FRI. H5 FLOW IS GENERALLY ZONAL WESTERLY BEYOND
THIS PERIOD.
ADJUSTED WEATHER TO REMOVE THUNDER THROUGH SATURDAY AS NO FOCUS
FOR DEEP CONVECTION APPEARS TO PRESENT ITSELF IN THE FORECAST
THROUGH THIS TIME. AN ISOLATED RUMBLE CAN`T BE RULED OUT BUT THE
DAY1-3 OUTLOOK DID NOT INCLUDE THE REGION IN GENERAL THUNDER SO I
EXTENDED THIS IDEA INTO DAY 4.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
MODEL SOLN DIFFERENCES DEVELOP WITH GFS KEEPING THE AREA WET AND
PHASING THE FLOWS. MEANWHILE...ECMWF/CMC/DGEX KEEP A SPLIT FLOW.
WILL FOLLOW THIS SPLIT FLOW SOLN WITH INITIAL WAVE PASSING TO THE
EAST BUT ANOTHER NRN S/W PASSING THRU LATE FRIDAY NIGHT. THIS WILL
KEEP A CHANCE OF PCPN INTO LATE FRIDAY NIGHT/EARLY SATURDAY TIME
FRAME.
WILL THEN ALLOW FOR A DRY PERIOD LATER SATURDAY AND SUNDAY WITH MID
LEVEL RIDGE BUILDING INTO THE GREAT LAKES/OHIO VALLEY. TEMPERATURES
TO STAY ABOVE NORMAL WITH HIGHS NEXT WEEKEND FROM THE LOWER 60S FAR
N TO NEAR 70 FAR SOUTH.
ANOTHER CHANCE FOR SHOWERS/THUNDERSTORMS RETURNS LATE SUNDAY
NIGHT/MONDAY AS THE NEXT S/W AND ASSOCIATED SFC LOW ARE EXPECTED TO
EJECT NE INTO THE OHIO VALLEY.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
CDFNT AND PCPN HAS PUSHED SOUTH OF THE TAFS LEAVING VFR
CONDITIONS. AFT 12Z...LOW PRESSURE WILL RIPPLE ALONG STALLED
FRONTAL BOUNDARY IN KY/TN. 00Z MODELS ARE SPREADING SOME LIGHT PCPN
PRECIPITATION N INTO THE SRN TAFS. WILL COVER THIS AT THE CVG/LUK
TAFS WITH A VCSH BETWEEN 15-21Z.
PRESSURE GRADIENT WILL TIGHTEN WITH PASSAGE OF THE LOW. WINDS WILL
GUST UP INTO THE LOWER 20 KNOTS BETWEEN 15Z AND 23Z.
OUTLOOK...SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE AT TIMES FROM
WEDNESDAY NIGHT THROUGH FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...JGL
SHORT TERM...FRANKS
LONG TERM...AR
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
703 AM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL SLIDE SOUTHEAST INTO THE AREA TODAY BEFORE
DROPPING SOUTH INTO THE CAROLINAS TONIGHT. A WEDGE OF HIGH
PRESSURE WILL BUILD IN BEHIND THE FRONT BY WEDNESDAY...AND LINGER
OVER THE REGION INTO AT LEAST FRIDAY. ANOTHER COLD FRONT WILL MOVE
ACROSS THE AREA OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM EDT TUESDAY...
FORECAST REMAINS QUITE COMPLICATED GIVEN THE SLOW MOVING COLD FRONT TO
THE WEST AND ASSOCIATED WEAK LOW PRESSURE THAT WILL SCOOT OUT OF THE TN
VALLEY AND INTO THE REGION LATER TODAY. THIS JUST AS THE FRONT FOLDS IN
FROM THE NORTH/NW ALLOWING LOW LEVEL CONVERGENCE TO MAXIMIZE THIS
MORNING INTO LATE AFTERNOON. MODELS HAVE AGAIN TRENDED FARTHER NORTH
WITH THE MAIN BAROCLINIC ZONE WHICH HAS SHIFTED THE AXIS OF BEST UPPER
DIFFLUENCE AND CORRESPONDING LIFT FARTHER NORTH/WEST. THIS WHILE
ALLOWING LESS UPSLOPE GIVEN VEERING FLOW FROM SOUTH/SE TO MORE SW AHEAD
OF THE BOUNDARY TODAY. CONSENSUS APPEARS FOR A STRIP OF HIGHER QPF FROM
SE WEST VA EAST INTO THE VA HIGHLANDS AND POINTS EAST WITH A SHARP
GRADIENT LIKELY NEAR HIGHWAY 460 AND POINTS SOUTH WHERE WILL SEE
MORE SCATTERED COVERAGE IN COMPARISON TO THE WIDESPREAD/HEAVIER
SHRA UP NORTH. HOWEVER WHERE TO DRAW THE LINE QUITE IFFY GIVEN
LIKELY TREND OF THINGS BEING OVERALL SLOWER PER THE WAVE TRACKING
NEAR BRISTOL THIS AFTERNOON BEFORE SHUNTING EAST/SE. THIS MAY
ALLOW MUCH MORE OF A DIFFERENTIAL HEATING ZONE OVER THE SOUTH
WHERE THE LATEST NAM HAS CAPES NEAR 1K J/KG ALONG THE VA/NC BORDER
PENDING MORE BREAKS AND SUBSEQUENT HEATING. SPEED MAX TRACKING
ACROSS LATE MAY ALSO SPARK CLUSTERS OF TSRA THAT COULD LINE UP
BEFORE SPILLING SOUTH. THUS BEEFING UP THUNDER MENTION SOUTH AND
INCLUDING IN THE HWO PER DAY1 MARGINAL OUTLOOK.
OTRW HAVE ADJUSTED POPS DOWN SOME TO INIT EARLY ON...WITH HIGHER CAT
POPS NORTH/WEST FOR MUCH OF THE DAY...AND SLOWLY INCREASING FROM NORTH
TO SOUTH AS THE FRONT SAGS SOUTH AND THE WAVE HEADS EAST SIMILAR TO THE
NAM. FORECAST QPF OF 1-3 INCHES ESPCLY NW PROMPTS THE NEED TO EXTEND
THE FLOOD WATCH INTO THE VA HIGHLANDS GIVEN LOW FFG AND PERHAPS FARTHER
EAST LATER PENDING TRENDS. LONGER PERIOD OF WARM ADVECTION BEFORE THE
FLOW TURNS NE...AND POSSIBLY SOME SUN SOUTH SUGGESTS HIGHS WARMER
THAN PREVIOUS WITH MOST IN THE 60S TO LOWER 70S...AND SOME MID OR
EVEN UPPER 70S POSSIBLE FAR SOUTH IF THINGS BREAK OPEN MORE.
WAVE HEADS EAST THIS EVENING ALLOWING THE SURFACE FRONT TO BOW THROUGH
THE REGION FROM THE NORTH BRINGING THE ONSET OF THE LOW LEVEL WEDGE
FROM NE TO SW OVERNIGHT. THIS SHOULD TAKE THE DEFORMATION TYPE ZONE OF
HEAVIER SHRA TO THE EAST BY MIDNIGHT WITH RESIDUAL LEFTOVER MOISTURE
MAKING FOR CONTINUED SPOTTY -RA ESPCLY SW WHERE WILL SEE A WEAK
INVERTED TROUGH DEVELOP UNDER THE EASTERLY FLOW. THUS AFTER MOSTLY
LIKELY POPS DURING THE EARLY EVENING WILL SHIFT TO A MORE CHANCE REGIME
FOR -RA AND EVEN SOME SPOTTY -DZ AS THE NIGHT WEARS ON GIVEN THE
DECREASING DEPTH TO THE MOISTURE OFF FORECAST RAOBS LATE. KEPT TEMPS
SIMILAR TO THE SLIGHTLY WARMER MET MOS PER EXPECTED SLOWER TRENDS WITH
THE DEVELOPING CAD.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 315 AM EDT TUESDAY...
EXPECTING THAT CONVECTION WILL DRIVE SFC COLD FRONT SOUTH OF US
BY WEDNESDAY MORNING ACROSS THE CAROLINAS. MAIN SHORTWAVE AND
ASSOCIATED LOW PRESSURE ALONG THE FRONT WILL BE OFFSHORE IN THE
ATLANTIC OCEAN. IN SITU CAD EVENT WILL BECOME WELL ESTABLISHED ON
WEDNESDAY. WITH CLOUDS AND RAIN...LOWERED HIGH TEMPERATURES FOR
WEDNESDAY. HIGHS FOR WEDNESDAY WILL BE BELOW NORMAL WITH READINGS
FROM AROUND 50 DEGREES IN THE MOUNTAINS TO NEAR 60 DEGREES IN THE
PIEDMONT. IN GENERAL...LEANED POPS TOWARDS THE NAM FOR WEDNESDAY AND
SHAPED OUR QPF TOWARDS HPC.
CLOUDY WITH AREAS OF RAIN AND FOG ARE ANTICIPATED WEDNESDAY NIGHT
INTO THURSDAY. PLACED HIGH POPS ACROSS THE SOUTH WHERE WEDGE UPGLIDE
OVERLAPS WITH SOME UPPER DIVERGENCE. LOW TEMPERATURES WEDNESDAY
NIGHT WILL RANGE FROM THE UPPER 30S IN THE MOUNTAINS TO THE LOWER
40S IN THE PIEDMONT. UNDERCUT MOS HIGH TEMPERATURES FOR THURSDAY
WITH PLENTY OF CLOUDS AND AREAS OF RAIN AND FOG UNDER CAD. HIGHS
WILL VARY FROM THE UPPER 40S IN THE NORTHWEST TO THE MID 50S IN THE
SOUTHEAST. THE CLOUDY DREARY WEATHER CONTINUES THURSDAY NIGHT INTO
FRIDAY WITH LOW TEMPERATURES GENERALLY FROM THE LOWER 40S IN THE
NORTHWEST MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 215 PM EDT MONDAY...
NORTHERN STREAM TROF OVER THE NORTHEAST AMPLIFIES WITH A SURFACE
COLD FRONT COMING THROUGH THE REGION ON SATURDAY. MEANWHILE A LOW IS
CLOSED OFF OVER THE ROCKIES ON FRIDAY.
CLOSED LOW OVER THE ROCKIES OPENS UP AND ALSO TRACKS INTO THE UPPER
MISSISSIPPI VALLEY SATURDAY AND SUNDAY...WITH A PIECE OF THIS SYSTEM
REACHING THE FORECAST AREA ON MONDAY. SURFACE HIGH PRESSURE CROSSES
THE NORTHEAST UNITED STATES SUNDAY THEN BY MONDAY...ALREADY BACK IN
YET ANOTHER WEDGE WITH DEEP SOUTHEAST UPSLOPE FLOW WITH STRONG 850
WINDS.
WILL KEEP SATURDAY NIGHT THROUGH SUNDAY NIGHT DRY. WEDGE MAY BE SLOW
TO BREAK ON FRIDAY WHICH MAY LIMIT MAXIMUM TEMPERATURES. BUT
SATURDAY AHEAD OF THE FRONT WILL BE MILDER. TEMPERATURES BEHIND THE
FRONT ON SUNDAY WILL BE AROUND NORMAL.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 640 AM EDT TUESDAY...
CIGS LOWERING THROUGH MVFR EARLY THIS MORNING AS MOISTURE
INCREASES AHEAD OF THE FRONT TO THE WEST AND WEAK LOW PRESSURE
TRAVERSING THROUGH THE TN VALLEY. HOWEVER ONGOING RAINFALL REMAINS
LIMITED GIVEN BEST LIFT TO THE WEST WITH ONLY A SLOW INFLUX OF
STRATUS ONGOING MAINLY VIA SOUTH/SE UPSLOPE FLOW ACROSS THE WEST.
MODELS REMAIN TOO FAST IN LOWERING CIGS/VSBYS SO GIVEN CURRENT
TRENDS WILL BACK OFF ONSET OF IFR/LIFR CONDITIONS FOR A WHILE WITH
POTENTIAL FOR MOST LOCATIONS TO STAY AT LEAST MVFR THROUGH MIDDAY.
OTRW WILL KEEP THE GOING EARLIER TREND IN HOLDING MOST SPOTS MVFR
INTO EARLY AFTERNOON WITH OCNL MVFR VSBYS AT TIMES ESPCLY
KLWB/KBLF THIS MORNING...AND ELSEWHERE THIS AFTERNOON AS THE
FRONT DIPS SOUTH AND RAINFALL BECOMES MORE WIDESPREAD.
ONCE THE FRONT BACKDOORS SOUTH INTO THE AREA THIS AFTERNOON WILL
SEE WINDS BECOME MORE EASTERLY FROM NORTH TO SOUTH DURING THE DAY
BUT MUCH SLOWER THAN EARLIER GIVEN THE FORECAST TRACK OF THE WAVE
TO BE FARTHER NORTH. THIS MAY AGAIN LIMIT THE SHOWER COVERAGE AT
KBCB/KROA/KDAN UNTIL LATER IN THE DAY WITH A SHARP GRADIENT
BETWEEN IFR/MVFR CIGS FROM KLWB/KLYH AND POINTS SOUTH WITH PERHAPS
MVFR TO VFR FOR A WHILE AROUND KDAN BEFORE LOWERING THIS AFTERNOON
AS THE FRONT/WAVE COMBO ACROSS THE REGION. FOR NOW WILL DELAY
LOWER CIGS FURTHER SOUTH THIS AFTERNOON BUT BRING ALL A PERIOD OF
IFR DURING THE AFTERNOON WITH A LONGER DURATION OF CONVECTIVE
POTENTIAL ACROSS THE SOUTH AT KDAN.
WAVE SHUNTS TO THE SE TONIGHT ALLOWING A DEEPENING WEDGE TO TAKE
SHAPE WITH WIDESPREAD IFR TO MVFR IN LINGERING LIGHT RAIN/DRIZZLE
AND FOG INTO THE OVERNIGHT.
EXTENDED AVIATION...
WEDNESDAY INTO THURSDAY...HIGH PRESSURE BEHIND THE FRONT WILL NOSE
SOUTH ALONG THE LEE OF THE APPALACHIANS...SETTING THE SCENE FOR A
COLD AIR DAMMING SCENARIO. AFTER A POTENTIAL BRIEF DECREASE IN
PRECIPITATION LATE TUESDAY NIGHT INTO EARLY WEDNESDAY...SOUTHEAST
FLOW WILL ALLOW FOR PRECIPITATION AND MORE IFR/MVFR CONDITIONS
ACROSS THE AREA...ESPECIALLY ACROSS THE SOUTHWEST PARTS OF THE
AREA.
THURSDAY NIGHT INTO FRIDAY...MODEL GUIDANCE DIFFERS ON THE
TIMING...BUT THE GENERAL TREND WILL BE ON THAT ALLOWS THE WEDGE TO
SLOWLY GIVES WAY TO INCREASING SOUTHWEST FLOW AHEAD OF A
SHORTWAVE TROUGH PROGRESSING INTO THE GREAT LAKES REGION...BUT NOT
COMPLETELY. THIS SHOULD ALLOW FOR SOME IMPROVEMENT TO FLIGHT
CATEGORIES...BUT SCATTERED SHOWERS AND THUNDERSTORMS WILL STILL BE
AN ISSUE.
THE AFOREMENTIONED SHORTWAVE TROUGH FRONT WILL BRING A COLD FRONT
THROUGH THE AREA ON SATURDAY. LOOK FOR MORE SUB-VFR
CONDITIONS...SHOWERS AND STORMS TO IMPACT THE AREA.
&&
.HYDROLOGY...
AS OF 330 AM EDT TUESDAY...
SHOWERS REMAIN SCATTERED ACROSS THE REGION EARLY THIS MORNING WITH
THE FRONT STILL WELL TO THE NW AND LOW PRESSURE OVER THE TN
VALLEY. LATEST HRRR SHOWS A SLOW FILLING IN OF PRECIP THROUGH THE
MORNING WITH THE MOST WIDESPREAD COVERAGE ESPCLY NORTHERN HALF
FROM MIDDAY THROUGH LATE AFTERNOON.
EXPECTED RAINFALL FOR MUCH OF THE FORECAST AREA WILL BE ONE TO TWO
INCHES EARLY WEDNESDAY. HOWEVER MODELS HAVE SHIFTED THE HEAVIER
AXIS OF PROJECTED RAINFALL NORTH ACROSS PARTS OF SOUTHEAST WEST
VIRGINIA INTO THE VIRGINIA HIGHLANDS WHERE POTENTIAL FOR TWO TO
THREE INCHES LOOKS POSSIBLE. GUIDANCE VALUES FOR RAINFALL IT WOULD
TAKE TO PRODUCE FLOODING ARE BELOW TWO INCHES FOR THE MOUNTAINS
AND ONLY AROUND AN INCH ACROSS THE VIRGINIA HIGHLANDS SO THE FLOOD
WATCH HAS BEEN EXTENDED TO COVER THOSE AREAS AS WELL. LIGHT TO
MODERATE RAIN WILL CONTINUE INTO THURSDAY ALONG THE BLUE RIDGE AND
IN THE FOOTHILLS IN FAR SOUTHWEST VIRGINIA INTO NORTHWEST NORTH
CAROLINA.
AT THIS TIME...THERE IS A LOW PROBABILITY OF MINOR MAINSTEM RIVER
FLOODING THROUGH THURSDAY. AREAL FLOODING OF SMALL STREAMS AND
CREEKS IS WHAT IS MORE LIKELY IF THE EXPECTED AMOUNT OF RAINFALL
OCCURS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH THROUGH THIS EVENING FOR VAZ007-010-011-018>020.
FLOOD WATCH THROUGH THIS EVENING FOR VAZ009-012-013-015-016.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ001>003-018>020.
WV...FLOOD WATCH THROUGH THIS EVENING FOR WVZ042>044-507-508.
&&
$$
SYNOPSIS...DS/JH
NEAR TERM...JH
SHORT TERM...KK
LONG TERM...AMS
AVIATION...DS/JH/MBS
HYDROLOGY...AMS/JH
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
940 AM CDT TUE APR 14 2015
.UPDATE...
AREA OF HIGH PRESSURE WILL STAY IN CONTROL OVER THE REGION TODAY.
CLEAR SKIES AND LIGHT WINDS WILL PERSIST THROUGHOUT THE DAY. DEW
POINTS LOOK TO DROP INTO THE LOWER 20S AND UPPER TEENS AS THE
BOUNDARY LAYER LOOKS TO MIX UP TO NEAR THE 800MB LEVEL ACCORDING
TO RAP MODEL BUFKIT SOUNDINGS. THE 14Z RACINE OBS SHOW AN 8KT
NORTHEAST WIND...INDICATING THE LAKE MI SEA BREEZE HAS ALREADY
ACTIVATED. TEMPS WILL BE COOLER ALONG THE LAKE SHORE THAN FURTHER
INLAND DUE TO THE SEA BREEZE.
&&
.AVIATION/18Z TAFS/...
VFR CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD. HIGH CIRRUS
CLOUDS WILL STICK AROUND FOR THE MORNING AND AFTN HOURS ALONG WITH
LIGHT WINDS. AN 8KT NORTHEAST WIND WAS REPORTED AT RACINE AT
14Z...SO THE LAKE BREEZE HAS ALREADY ACTIVATED. THESE ON-SHORE
WINDS COULD APPEAR IN ENW AND MKE WITHIN THE NEXT FEW HOURS.
&&
.PREV DISCUSSION... /ISSUED 329 AM CDT TUE APR 14 2015/
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
DEEP RIDGING WILL BRING QUIET WEATHER ACROSS THE AREA. THE CENTER OF
THE SURFACE HIGH PRESSURE WILL SLIDE ACROSS SOUTHERN WISCONSIN
TODAY. SO LIGHT WINDS AND FULL SUNSHINE EXPECTED. EASTERLY WINDS
WILL KICK IN BY LAKE MICHIGAN...SO MUCH COOLER NEAR THE LAKE VS
INLAND AREAS. SOUNDINGS SHOW GOOD MIXING UP TO 850MB SO DEWPOINTS
SHOULD TANK INTO THE TEENS TO LOWER 20S MOST PLACES...EXCEPT NEAR
THE LAKE.
THE DRY DEWPOINTS SHOULD ALLOW FOR SOME DECENT RADIATIONAL COOLING
TONIGHT...THOUGH AS THE RIDGE SLIDES EAST OF US BY EVENING...THE
RETURN FLOW WILL TEMPER SOME OF THAT.
WEDNESDAY THROUGH THURSDAY NIGHT...FORECAST CONFIDENCE HIGH.
SURFACE HIGH PRESSURE WILL DOMINATE THIS PERIOD AND BRING QUIET AND
MILD WEATHER TO SOUTHERN WI. IT WILL BE WARM INLAND WITH HIGHS IN
THE UPPER 60S... BUT A STEADY EAST WIND OFF THE LAKE WILL KEEP
LAKESHORE TEMPS IN THE 50S.
A MID LEVEL SHORTWAVE WILL BRING SOME CLOUDS TO THE AREA WED NIGHT
INTO THU MORNING. THERE COULD BE A FEW SPRINKLES WITH THIS FEATURE
BUT OVERALL A DRY FORECAST.
LONG TERM...
FRIDAY THROUGH MONDAY... FORECAST CONFIDENCE MEDIUM.
IT IS VERY TYPICAL FOR VARIOUS MODELS TO HANDLE CLOSED UPPER LOWS IN
DIFFERENT WAYS. A CLOSED UPPER LOW OVER THE FOUR CORNERS REGION WILL
EJECT INTO THE PLAINS LATER IN THE WEEK AND EVENTUALLY GET ABSORBED
INTO AN UPPER TROUGH SWINGING THROUGH THE UPPER MIDWEST AND GREAT
LAKES EARLY NEXT WEEK.
A SHORTWAVE TROUGH TRACKING ACROSS SOUTHERN ONTARIO COULD BRING SOME
LIGHT RAIN TO PORTIONS OF SOUTHERN WI ALONG A SURFACE TROUGH FRI
AFTERNOON AND EVENING. ONLY A SLIGHT CHANCE IN THE FCST SINCE MOST
MODELS KEEP US DRY. THE GFS IS THE WET MODEL FOR THE WEEKEND...
SINCE IT EJECTS THAT CLOSED UPPER LOW INTO THE MIDWEST EARLIER
THAN THE ECWMF AND CANADIAN MODELS. THE ECWMF AND CANADIAN MODELS
ARE DELAYED UNTIL SUNDAY NIGHT/MONDAY. WENT WITH A CONSENSUS OF
MODELS FOR PRECIP CHANCES FOR THIS PERIOD.
TEMPERATURES WILL BE COOLER FOR THE FIRST HALF OF NEXT WEEK IN THE
WAKE OF THE UPPER TROUGH WITH HIGHS IN THE 50S.
AVIATION/12Z TAFS/...
VFR CONDITIONS THROUGH THE TAF PERIOD. WINDS LESS THAN 10KTS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...JTS
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
WEDNESDAY THROUGH MONDAY...MRC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
528 AM CDT TUE APR 14 2015
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY
ISSUED AT 308 AM CDT TUE APR 14 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SPLIT FLOW
ACROSS NORTH AMERICA CONSISTING OF A RIDGE OVER THE ROCKIES...A
TROUGH OVER THE SOUTHERN PLAINS...AND CONVERGING UPPER FLOW ACROSS
THE EAST. THE WESTERN GREAT LAKES RESIDES DOWNSTREAM OF THE
RIDGE...WITH STRONG SUBSIDENCE LEADING TO CLEAR CONDITIONS ACROSS
THE REGION. THE AIRMASS ITSELF IS VERY DRY WITH PWATS FALLING BELOW
A QUARTER OF AN INCH. AS THE DRY SURFACE HIGH MOVES ACROSS THE
REGION...TEMPS AND HUMIDITIES ARE THE MAIN FORECAST CONCERNS THROUGH
WEDNESDAY.
TODAY...HIGH PRESSURE WILL DRIFT ACROSS THE REGION...WHICH WILL
PROMOTE CLEAR SKIES AND LIGHT WINDS. EVEN THOUGH UPSTREAM OBS SAW
DEWPOINTS CRASH INTO THE SINGLE DIGITS OVER MINNESOTA AND NORTH
DAKOTA IN THIS AIRMASS...SHOULD NOT HAVE THE KIND OF MECHANICAL
MIXING THIS REGION SAW YESTERDAY. HOWEVER...SHOULD SEE MIXING UP TO
800-750MB...WHICH SUPPORTS DROPPING DEWPOINTS INTO THE LOW TEENS UP
NORTH. COMBINED WITH HIGHS MAINLY IN THE MID TO UPPER 60S AWAY FROM
LAKE MICHIGAN...HUMIDITIES SHOULD FALL INTO THE TEENS. ELEVATED
FIRE WEATHER CONDITIONS WILL THEREFORE CONTINUE TODAY.
TONIGHT...HIGH PRESSURE WILL REMAIN PRESENT ACROSS THE REGION.
SHOULD SEE THIN CIRRUS INVADE FROM THE SOUTH AHEAD OF A WEAK UPPER
LOW ACROSS THE PLAINS. OTHERWISE QUIET...WITH LOWS FALLING INTO THE
UPPER 30S TO LOW 40S.
WEDNESDAY...CIRRUS WILL CONTINUE TO INVADE THE REGION AND BECOME
THICKER...WHICH WILL LEAD TO FILTERED SUNSHINE. THE SURFACE HIGH
WILL MOVE TO THE EASTERN GREAT LAKES...WHICH WILL CAUSE EAST TO
SOUTHEAST WINDS TO BECOME RELATIVELY STRONGER THAN TODAYS EXPECTED
SPEEDS. THE AIRMASS WILL MOISTURE SOME...BUT STILL WENT WITH THE
LOWEST GUIDANCE...WHICH PLACES RH VALUES BETWEEN 15 TO 25 PERCENT.
NO REPRIEVE FROM ELEVATED FIRE WEATHER CONDITIONS AS A RESULT.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
ISSUED AT 308 AM CDT TUE APR 14 2015
CONTINUED WARM AND DRY CONDITIONS WILL CONTINUE INTO THE
WEEKEND...WITH ONLY A SMALL CHANCE OF SHOWERS FRIDAY INTO FRIDAY
EVENING. A MORE POTENT SYSTEM IS EXPECTED TO AFFECT THE REGION
EARLY NEXT WEEK.
FOR WEDNESDAY NIGHT...AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE
REGION. MODEL SOUNDINGS WERE BONE DRY...THUS REMOVED ANY MENTION OF
RAIN DESPITE STEEP MID LEVEL LAPSE RATES WITH THIS SYSTEM. ON
THURSDAY...MODEL SOUNDINGS STILL SHOW VERY DRY SOUNDINGS ALTHOUGH
NOT AS DRY AS TUESDAY AND WEDNESDAY SOUNDINGS. DID LOWER DEW
POINTS BY 3 TO 5 DEGREES MOST PLACES AS A STARTING POINT. WEAK
BOUNDARY EXPECTED TO MOVE ACROSS THE REGION ON FRIDAY...BRINGING
A SMALL CHANCE OF SHOWERS. MODELS DO SHOW MORE MOISTURE WITH THIS
FEATURE TO SUPPORT THE SMALL CHANCE OF SHOWERS.
HIGH PRESSURE WILL BUILD INTO THE REGION ON SATURDAY AND CONTINUE
INTO SUNDAY. VERY DRY CONDITIONS ARE EXPECTED AGAIN SATURDAY WITH
VERY LOW AFTERNOON RELATIVE HUMIDITY READINGS. ATTENTION THEN TURNS
TO UPPER LOW ACROSS THE CENTRAL UNITED STATES WILL INTERACT WITH
500MB TROUGH MOVING ACROSS SOUTHERN CANADA. THIS FEATURE SHOULD
ALLOW FOR LOW PRESSURE TO FORM AND BRING A CHANCE OF RAIN TO THE
AREA SUNDAY NIGHT AND MONDAY.
DID LOWER MIN TEMPERATURES WEDNESDAY NIGHT AND THURSDAY NIGHT...
WHILE RAISING MAX TEMPERATURES A DEGREE OR TWO ON MOST DAYS INTO
THE WEEKEND.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 527 AM CDT TUE APR 14 2015
GOOD FLYING WEATHER WILL BE PRESENT THROUGH WEDNESDAY NIGHT THANKS
TO A VERY DRY HIGH PRESSURE SYSTEM MOVING ACROSS THE REGION.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
152 PM MST TUE APR 14 2015
.SYNOPSIS...A DRY COLD FRONT WILL PUSH SOUTHWARD THROUGH SOUTHEAST
CALIFORNIA AND ARIZONA TONIGHT AND WEDNESDAY. THIS WILL LEAD TO VERY
WINDY CONDITIONS OVER SOUTHEAST CALIFORNIA AND WESTERN ARIZONA. WINDS
WILL NOT BE QUITE AS STRONG OVER SOUTH-CENTRAL ARIZONA. THE FRONTAL
PASSAGE WILL ALSO LEAD TO MUCH COOLER TEMPERATURES...DIPPING BELOW
THE NORMAL BY THURSDAY. EXPECT A WARMING TREND FRIDAY THROUGH SUNDAY
WITH LITTLE CHANGE MONDAY.
&&
.DISCUSSION...WELL-DEFINED TROUGH ACROSS THE GREAT BASIN CONTINUES TO
TRANSLATE EASTWARD TODAY. STRONG WINDS HAVE ALREADY BEEN A MAJOR
IMPACT WITH THIS SYSTEM...PARTICULARLY IN THE SALT LAKE CITY AREA.
THIS PORTENDS A WINDY DAY TOMORROW ACROSS THE DESERT SOUTHWEST. UNTIL
THEN...PRE-FRONTAL REGIME WILL CONTINUE WITH WELL ABOVE NORMAL
TEMPERATURES.
RESIDUAL MOISTURE BELOW 600 MB IS APPARENT ACROSS SE AZ IN THE WAKE
OF THE TROUGH ACROSS NM WHILE MODEL DEPICTIONS OF THIS MOISTURE HAVE
VARIED CONSIDERABLY. EARLIER RUNS OF THE HRRR HAD SUGGESTED THE
POTENTIAL FOR CONVECTION ACROSS CENTRAL ARIZONA BUT THE LATEST RUNS
HAVE CORRECTLY TRENDED EASTWARD THIS AFTERNOON. LATEST SATELLITE
SHOWS CU DEVELOPING ACROSS EASTERN PIMA COUNTY AND POPS WERE LOWERED
ACROSS PINAL COUNTY FOR THIS AFTERNOON. FOCUS FOR THIS AFTERNOON REMAINS
ACROSS THE HIGHER ELEVATIONS OF SOUTHERN AND EASTERN AZ...WHERE
THUNDERSTORMS HAVE DEVELOPED ACROSS THE WHITE MOUNTAINS.
HOWEVER...STRONGEST FORCING FOR ASCENT IS STRONGER OFF TO THE WEST
CLOSER TO THE APPROACHING TROUGH AND ANY ACTIVITY THAT DOES DEVELOP
WILL ONLY BE ISOLATED IN COVERAGE. OTHERWISE...EXPECT MAINLY CLEAR
SKIES OVERNIGHT WITH A CONTINUATION OF THE ABOVE NORMAL TEMPERATURES.
&&
.PREVIOUS DISCUSSION... TONIGHT THROUGH THURSDAY...THE BRUNT OF THE
AFOREMENTIONED PACIFIC LOW PRESSURE SYSTEM WILL INITIALLY AFFECT
AREAS WELL NORTH OF OUR FORECAST AREA. HOWEVER...THERE WILL BE A DRY
COLD FRONT THAT PUSHES THROUGH SOUTHEAST CALIFORNIA AND ARIZONA
BEGINNING TONIGHT AND CONTINUING WEDNESDAY. VERY STRONG NORTHERLY
WINDS IN THE LOWER LEVELS WILL BE ASSOCIATED WITH THE FRONTAL
PASSAGE...MOST NOTABLY FOR WESTERN PORTIONS OF OUR FORECAST AREA IN
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA. THUS A WIND ADVISORY IS
IN EFFECT FOR THOSE AREAS. AREAS OF BLOWING DUST/SAND WILL BE
POSSIBLE AS WELL. VERY DRY AIR WILL ALSO BE USHERED IN AND THE FIRE
WEATHER WATCH WAS UPGRADED TO A RED FLAG WARNING. SEE W/W/A SECTION
BELOW FOR TIMING AND AFFECTED ZONES. THE MODELS DEPICT THE UPPER
TROUGH...INITIALLY CENTERED WELL TO OUR NORTH...TRACKING
SOUTHEASTWARD AND BECOMING A CLOSED LOW OVER THE SOUTHERN
ROCKIES/FOUR CORNERS AREA. THE GFS CONTINUES TO HAVE IT CENTERED
NORTHEAST OF THE ECMWF SOLUTION. LATEST GEM IS MORE CLOSELY ALIGNED
WITH ECMWF. THOSE MODELS ARE GENERALLY SUPPORTED BY THEIR RESPECTIVE
ENSEMBLE MEANS. THE ECMWF AND GEM SOLUTIONS HAVING THE COLD CORE
CLOSER TO OUR FORECAST AREA. MEANWHILE...VORT LOBES/JET STREAKS
ROTATE AROUND THE LOW. HOWEVER...MOISTURE AVAILABILITY OVER OUR
FORECAST AREA WILL BE QUITE MEAGER SO HELD OFF ON INTRODUCING POPS.
THERE WILL BE AT LEAST LINGERING BREEZINESS...WINDY CONDITIONS
WEDNESDAY NIGHT WITH ONE OF THOSE VORT LOBES PUSHING THROUGH. BIGGEST
BENEFIT OF THIS SYSTEM WILL BE MUCH COOLER TEMPERATURES WEDNESDAY AND
THURSDAY...AT LEAST A FEW DEGREES BELOW NORMAL BY THURSDAY.
FRIDAY THROUGH MONDAY... THE LOW SLOWLY MOVES EASTWARD FRIDAY
THROUGH SUNDAY AND HEIGHTS/THICKNESSES REBOUND. ACCORDINGLY...A
WARMING TREND BEGINS FRIDAY WITH HIGHS BACK TO THE LOW 90S ON THE
LOWER ELEVATIONS BY SUNDAY. WEAK UNDERCUTTING OF THE RIDGE OVER THE
WEST EARLY NEXT WEEK KEEPS TEMPS FLAT.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SURFACE WINDS WILL PICK UP OVERNIGHT ACROSS SOUTHEAST CALIFORNIA AND
ALONG THE LOWER COLORADO RIVER VALLEY WITH THE APPROACH OF A STRONG
UPPER LEVEL LOW...WITH NORTHERLY WIND GUSTS OF 25-30KT POSSIBLE AT
TIMES EARLY WEDNESDAY MORNING NEAR KBLH AND KIPL. STRONGEST WINDS
AND GUSTS UP TO 40KT EXPECTED TO OCCUR AFTER 12Z WEDNESDAY MORNING
AND CONTINUE THROUGH THE DAY...THE STRONGER WIND FIELD EXPANDING
EAST ACROSS SOUTH-CENTRAL ARIZONA...WESTERLY WIND GUSTS UP TO 30KT
POSSIBLE NEAR KPHX/KIWA/KSDL WEDNESDAY AFTERNOON. LOCALIZED BLOWING
DUST COULD LIMIT VISIBILITY AT TIMES AT TAF SITES...BUT CONFIDENCE
IN TIMING AND LOCATION WILL KEEP MENTION OUT OF ALL TAFS AT THIS
TIME.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...HIGH PRESSURE WILL BUILD BACK OVER THE
DESERT SOUTHWEST...WITH SUBSTANTIALLY DRIER AIR ENTRENCHED ACROSS THE
REGION. THIS PATTERN WILL KEEP TEMPERATURES WARM...AND SURFACE
CONDITIONS DRY. ANTICIPATE LIGHT WINDS THROUGH THE PERIOD...DAYTIME
HUMIDITY VALUES IN THE SINGLE DIGITS...WITH WIDESPREAD POOR TO FAIR
OVERNIGHT RECOVERY IN MANY AREAS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...RED FLAG WARNING FROM 5 AM TO 9 PM MST WEDNESDAY FOR AZZ131>133.
WIND ADVISORY FROM 2 AM TO 9 PM MST WEDNESDAY FOR AZZ020-021-025-
026.
CA...RED FLAG WARNING FROM 5 AM TO 9 PM PDT WEDNESDAY FOR CAZ231.
WIND ADVISORY FROM 2 AM TO 9 PM PDT WEDNESDAY FOR CAZ030>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...AJ
AVIATION....MEYERS
FIRE WEATHER...MEYERS
AREA FORECAST DISCUSSION
NWS TUCSON AZ
1006 AM MST TUE APR 14 2015
.SYNOPSIS...A FEW SHOWERS AND THUNDERSTORMS POSSIBLE AGAIN THIS
AFTERNOON. A STRONGER STORM SYSTEM DIGGING TOWARD THE REGION FROM
THE NORTHWEST WILL BRING STRONG GUSTY WINDS WEDNESDAY AND THURSDAY
ALONG WITH A SHOT OF MUCH COOLER AIR. UNSEASONABLY COLD OVERNIGHT
LOWS IN SOME LOCATIONS ARE POSSIBLE LATE IN THE WEEK.
&&
.DISCUSSION...STILL LOOKING AT SOME RESIDUAL MOISTURE ACROSS THE
AREA. MODELS SUGGEST A FEW SHOWERS OR THUNDERSTORMS POSSIBLE THIS
AFTERNOON MAINLY IN THE MOUNTAINS. OTHERWISE...MOSTLY CLEAR. CURRENT
FORECAST LOOKED ON TRACK SO NO UPDATES NECESSARY THIS MORNING.
PLEASE REFER TO THE ADDITIONAL SECTIONS ABOUT THE UPCOMING WEATHER
CHANGES THIS WEEK.
&&
.AVIATION...VALID THRU 15/18Z.
SURFACE WINDS GENERALLY LESS THAN 12 KTS THIS MORNING UNDER MOSTLY
CLEAR SKIES. ISOLATED -SHRA/-TSRA POSSIBLE THIS AFTERNOON. WLY WINDS
8-12 KTS DURING THE DAY WITH SCT CLOUDS AOA 15K FT AGL. GUSTY ERRATIC
OUTFLOWS AT TIMES ASSOCIATED CONVECTION. NORMAL DIURNAL WIND TRENDS
RETURNING OVERNIGHT. A STRONG SYSTEM DIGGING DOWN FROM THE NORTH
WILL BRING WINDY CONDITIONS TO THE AREA WEDNESDAY. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...BECOMING PARTLY CLOUDY WITH ISOLATED SHOWERS AND
THUNDERSTORMS AROUND THE AREA TODAY. STRONG GUSTY OUTFLOWS POSSIBLE
WITH SOME STORMS.
A DEVELOPING LOW PRESSURE SYSTEM IS EXPECTED TO DROP OUT OF THE
PACIFIC NW TONIGHT AND THEN MOVE OVER NORTHEAST ARIZONA LATE
WEDNESDAY INTO THURSDAY MORNING. THIS SYSTEM IS EXPECTED TO SPREAD
STRONG WINDS AND DRY AIR ACROSS THE AREA WEDNESDAY INTO THURSDAY AS
WELL AS MUCH COOLER TEMPERATURES THURSDAY. STRONG AND GUSTY WESTERLY
WINDS WEDNESDAY WITH FALLING RH VALUES THROUGH THE DAY ARE EXPECTED
TO CAUSE CRITICAL FIRE WEATHER CONDITIONS BY WEDNESDAY AFTERNOON
ACROSS MOST OF SOUTHEAST ARIZONA. A RED FLAG WARNING HAS BEEN ISSUED
FOR MOST OF SOUTHEAST ARIZONA FROM LATE WEDNESDAY MORNING INTO
WEDNESDAY EVENING.
THE DRY AIR WILL BE IN PLACE ON THURSDAY BUT THE WINDS WILL BE
SLIGHTLY WEAKER. WE WILL CONTINUE TO EVALUATE THURSDAY FOR ANY
POSSIBLE FIRE WEATHER CONCERNS. WINDS WILL DIMINISH SOMEWHAT BY
FRIDAY AFTERNOON INTO THE COMING WEEKEND WITH DRY CONDITIONS ACROSS
THE AREA.
&&
.PREV DISCUSSION...WE CONTINUE TO HANG ON TO A REASONABLE AMOUNT OF
MOISTURE FOR A PERIOD IN BETWEEN SYSTEMS...WITH SURFACE DEW POINTS
IN THE 30S AND 40S ALONG WITH PRECIPITABLE WATER VALUES AROUND .5 TO
.7 INCHES. SHORT RANGE HIGH RESOLUTION MODELS SUCH AS THE HRRR AGAIN
SPRINKLE CONVECTION AROUND SOUTHEAST AND SOUTH CENTRAL ARIZONA THIS
AFTERNOON. A PARTICULAR FOCUS IS SETTING UP ASSOCIATED WITH A MID
LEVEL INFLECTION THROUGH CENTRAL PIMA COUNTY THIS AFTERNOON...SO WE
HAVE ADDED ISOLATED THUNDERSTORMS TO SOME AREAS WEST OF TUCSON AS
WELL.
STILL ON TRACK FOR A SIGNIFICANT SPLIT OF ENERGY FROM THE NORTHWEST
INTO THE FOUR CORNERS REGION OVER THE NEXT 48 HOURS. THIS WILL BRING
STRONG GUSTY WINDS ACROSS THE ENTIRE AREA WEDNESDAY WITH VERY DRY
AIR BEHIND AN ASSOCIATED COLD FRONT SWEEPING DOWN FROM THE NORTH
DURING THE DAY WEDNESDAY. THE RAPIDLY DRYING CONDITIONS AROUND MID
DAY THROUGH THE AFTERNOON AND EVENING IS LEADING US TO ISSUE A RED
FLAG WARNING FOR WEDNESDAY IN ASSOCIATION WITH FIRE WEATHER
HEADLINES ISSUED BY PSR. PLEASE SEE THE FIRE WEATHER DISCUSSION
BELOW FOR ADDITIONAL DETAILS.
THE LOW WILL THEN SAG INTO NORTHEAST ARIZONA AND NORTHWEST NEW
MEXICO THURSDAY...HOWEVER A DRY INLAND TRAJECTORY ON THIS SYSTEM
WILL SEE LIMITED MOISTURE FOR OUR AREA. VERY COOL AIR HOWEVER...WITH
TEMPERATURES AT LEAST 10 DEGREES BELOW CLIMATOLOGY THURSDAY.
UNSEASONABLY COOL OVERNIGHT LOWS THURSDAY NIGHT AND FRIDAY
NIGHT...WITH LATE SEASON FREEZING TEMPERATURES POSSIBLE IN COLDER
EASTERN VALLEY LOCATIONS INCLUDING SULPHUR SPRINGS VALLEY IN COCHISE
COUNTY. A DEFINITE CONCERN FOR AGRICULTURE IN SOUTHEAST ARIZONA.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...RED FLAG WARNING WEDNESDAY FROM
11 AM UNTIL 8 PM FOR MUCH OF SOUTHEAST ARIZONA INCLUDING FIRE
WEATHER ZONES AZZ150-151...NORTHERN PORTIONS OF 152....AND
SOUTHERN PORTIONS OF 153.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
935 AM MST TUE APR 14 2015
.SYNOPSIS... THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS OVER
PORTIONS OF SOUTH-CENTRAL ARIZONA TODAY BUT WITH LITTLE IF ANY
RAINFALL. OTHERWISE EXPECT ANOTHER WARM DAY. A DRY COLD FRONT PUSHES
THROUGH SOUTHEAST CALIFORNIA AND ARIZONA TUESDAY NIGHT AND
WEDNESDAY. THIS WILL LEAD TO VERY WINDY CONDITIONS OVER SOUTHEAST
CALIFORNIA AND WESTERN ARIZONA. WINDS WILL NOT BE QUITE AS STRONG
OVER SOUTH-CENTRAL ARIZONA. THE FRONTAL PASSAGE WILL ALSO LEAD TO
MUCH COOLER TEMPERATURES...DIPPING BELOW THE NORMAL BY THURSDAY.
EXPECT A WARMING TREND FRIDAY THROUGH SUNDAY WITH LITTLE CHANGE
MONDAY.
&&
.DISCUSSION... LATEST RAP STREAMLINE ANALYSIS SHOWS A LARGE TROUGH
TRANSLATING EASTWARD THROUGH THE GREAT BASIN TOWARDS UT. AHEAD OF
THIS TROUGH...SKIES ARE SUNNY ACROSS THE DESERT SOUTHWEST AND
ANOTHER DAY OF ABOVE AVERAGE TEMPERATURES IS EXPECTED.
MEANWHILE...LATEST TWC SOUNDING INDICATES THAT RICHER MOISTURE
RESIDES BELOW 600 MB IN THE WAKE OF THE TROUGH ACROSS NM. SOME OF
THE WRF-BASED GUIDANCE HAS PICKED UP ON THIS MOISTURE AND SUGGESTS
THAT ISOLATED CONVECTION WILL DEVELOP THIS AFTERNOON. CU IS ALREADY
FORMING ACROSS THE WHITE MOUNTAINS AND THE GENERAL CONSENSUS AMONGST
THE HI-RES GUIDANCE IS THAT THE THREAT OF SHOWERS AND THUNDERSTORMS
WILL BE CONFINED TO SE AZ. POPS WERE LOWERED FOR PINAL COUNTY FOR
THIS AFTERNOON. NEVERTHELESS...THE CHANCE FOR PRECIPITATION IS NON-
ZERO BUT LESS THAN 10 PERCENT.
&&
.PREVIOUS DISCUSSION... TONIGHT THROUGH THURSDAY...THE BRUNT OF THE
AFOREMENTIONED PACIFIC LOW PRESSURE SYSTEM WILL INITIALLY AFFECT
AREAS WELL NORTH OF OUR FORECAST AREA. HOWEVER...THERE WILL BE A DRY
COLD FRONT THAT PUSHES THROUGH SOUTHEAST CALIFORNIA AND ARIZONA
BEGINNING TUESDAY NIGHT AND CONTINUING WEDNESDAY. VERY STRONG
NORTHERLY WINDS IN THE LOWER LEVELS WILL BE ASSOCIATED WITH THE
FRONTAL PASSAGE...MOST NOTABLY FOR WESTERN PORTIONS OF OUR FORECAST
AREA IN SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA. THUS A WIND
ADVISORY IS IN EFFECT FOR THOSE AREAS. AREAS OF BLOWING DUST/SAND
WILL BE POSSIBLE AS WELL. VERY DRY AIR WILL ALSO BE USHERED IN AND
THE FIRE WEATHER WATCH WAS UPGRADED TO A RED FLAG WARNING. SEE W/W/A
SECTION BELOW FOR TIMING AND AFFECTED ZONES. THE MODELS DEPICT THE
UPPER TROUGH...INITIALLY CENTERED WELL TO OUR NORTH...TRACKING
SOUTHEASTWARD AND BECOMING A CLOSED LOW OVER THE SOUTHERN
ROCKIES/FOUR CORNERS AREA. THE GFS CONTINUES TO HAVE IT CENTERED
NORTHEAST OF THE ECMWF SOLUTION. LATEST GEM IS MORE CLOSELY ALIGNED
WITH ECMWF. THOSE MODELS ARE GENERALLY SUPPORTED BY THEIR RESPECTIVE
ENSEMBLE MEANS. THE ECMWF AND GEM SOLUTIONS HAVING THE COLD CORE
CLOSER TO OUR FORECAST AREA. MEANWHILE...VORT LOBES/JET STREAKS
ROTATE AROUND THE LOW. HOWEVER...MOISTURE AVAILABILITY OVER OUR
FORECAST AREA WILL BE QUITE MEAGER SO HELD OFF ON INTRODUCING POPS.
THERE WILL BE AT LEAST LINGERING BREEZINESS...WINDY CONDITIONS
WEDNESDAY NIGHT WITH ONE OF THOSE VORT LOBES PUSHING THROUGH.
BIGGEST BENEFIT OF THIS SYSTEM WILL BE MUCH COOLER TEMPERATURES
WEDNESDAY AND THURSDAY...AT LEAST A FEW DEGREES BELOW NORMAL BY
THURSDAY.
FRIDAY THROUGH MONDAY... THE LOW SLOWLY MOVES EASTWARD FRIDAY
THROUGH SUNDAY AND HEIGHTS/THICKNESSES REBOUND. ACCORDINGLY...A
WARMING TREND BEGINS FRIDAY WITH HIGHS BACK TO THE LOW 90S ON THE
LOWER ELEVATIONS BY SUNDAY. WEAK UNDERCUTTING OF THE RIDGE OVER THE
WEST EARLY NEXT WEEK KEEPS TEMPS FLAT.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CERTAINLY LOOKING AT A QUIET WEATHER DAY ACROSS SOUTHEAST CALIFORNIA
ALTHOUGH WINDS WILL PICK UP EARLY WEDNESDAY MORNING. MEANWHILE AROUND
PHOENIX WINDS WILL FOLLOW TYPICAL DIURNAL TRENDS WITH MOSTLY CLEAR
SKIES. COULD BE SOME DISTANT CU TO THE SOUTH/EAST OF
PHOENIX...POSSIBLY SOME VIRGA AND/OR ISOLATED SHOWERS AS WELL.
SHOULD NOT IMPACT THE TERMINALS DIRECTLY BUT GIVEN THE VERY DRY SUB-
CLOUD LAYER...WILL NEED TO MONITOR ANY SHOWERS FOR BLDU.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
AN AREA OF LOW PRESSURE WILL CONTINUE TO MOVE THROUGH THE FOUR
CORNERS REGION THURSDAY AND FRIDAY. HOWEVER...DRY AIR WILL REMAIN
IN PLACE INTO THE WEEKEND...AND WITH VERY LITTLE ATMOSPHERIC
MOISTURE...THERE WILL BE NO PRECIPITATION...JUST SOME PASSING HIGH
CLOUDS. WINDS WILL BE MUCH LIGHTER THROUGH FRIDAY INTO THE WEEKEND.
EXPECT FAIR/POOR OVERNIGHT RECOVERIES DURING THE PERIOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...RED FLAG WARNING FROM 5 AM TO 9 PM MST WEDNESDAY FOR AZZ131-132.
WIND ADVISORY FROM 2 AM TO 9 PM MST WEDNESDAY FOR AZZ020-021-025-
026.
CA...RED FLAG WARNING FROM 5 AM TO 9 PM PDT WEDNESDAY FOR CAZ231.
WIND ADVISORY FROM 2 AM TO 9 PM PDT WEDNESDAY FOR CAZ030>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...AJ
AVIATION...LEINS
FIRE WEATHER...LEINS/MEYERS
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
ISSUED BY NATIONAL WEATHER SERVICE SALT LAKE CITY UT
452 PM MDT TUE APR 14 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 411 PM MDT TUE APR 14 2015
THE APPROACHING UPPER TROUGH IS CURRENTLY CENTERED OVER EASTERN
NEVADA PER LATEST WATER VAPOR IMAGERY AND RAP ANALYSIS WITH
ASSOCIATED COLD FRONT HAVING ALREADY CROSSED THE NORTHWESTERN
QUADRANT OF UTAH. THE FRONT IS EXPECTED TO REACH NORTHEAST AND
EAST-CENTRAL UTAH BY 00Z...THEN CROSS INTO WESTERN COLORADO DURING
THE EVENING HOURS. STRONG WINDS HAVE MATERIALIZED OVER THE
FORECAST AREA...ESPECIALLY UTAH AND NORTHWEST COLORADO ZONES WITH
MANY REPORTS OF GUSTS OVER 40 MPH. WINDS SHOULD CONTINUE TO
INCREASE THROUGH THE REMAINDER OF THE AFTERNOON AND INTO THE
EVENING HOURS...REMAINING GUSTY ON BOTH SIDES OF THE COLD FRONT.
GOING WIND HIGHLIGHTS LOOK GOOD AND WILL CONTINUE THROUGH LATE
TONIGHT.
SOME CUMULUS BLOWUPS ARE CURRENTLY SEEN ON SATELLITE ALTHOUGH NOT
MUCH IN THE WAY OF SHOWERS ARE EVIDENT AS OF YET. SOME PREFRONTAL
SHOWERS ARE STILL POSSIBLE THROUGH THIS EVENING BUT EXPECT
PRECIPITATION TO FILL IN MORE BEHIND THE FRONT. SNOW LEVELS WILL
LOWER QUICKLY WITH HIGHER VALLEYS STARTING TO SEE A THREAT OF
SNOW LATE TONIGHT.
HOWEVER...THE TROUGH IS EXPECTED TO PINCH OFF INTO A CLOSED LOW
TONIGHT WHICH WILL SLOW ITS EASTWARD PROGRESSION AND WEAKEN THE
FRONT AS IT CONTINUES THROUGH THE EASTERN PORTIONS OF THE FORECAST
AREA. AS SUCH...PRECIPITATION AMOUNTS/RATES ARE NOT EXPECTED TO BE
VERY SIGNIFICANT. THE LOW CENTER WILL REMAIN NEAR THE
UTAH/COLORADO BORDER TOMORROW BEFORE SETTLING OVER THE FOUR
CORNERS AREA BY TOMORROW NIGHT. THIS WILL KEEP UNSETTLED WEATHER
OVER THE AREA TOMORROW.
WITH MUCH COLDER AIR FILTERING BEHIND THE FRONT...EXPECT MAX
TEMPERATURES TOMORROW 25-30 DEGREES COOLER ACROSS MANY AREAS. THIS
COOLER AIR WILL ALSO BRING A POTENTIAL FOR FREEZING TEMPERATURES
TOMORROW NIGHT. A FREEZE WATCH REMAINS IN EFFECT AS A RESULT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 411 PM MDT TUE APR 14 2015
THE OPERATIONAL GFS IS MORE PROGRESSIVE THAN THE ECMWF/GEM
SOLUTION REGARDING THE CLOSED LOW...WITH CONSIDERABLE SPREAD AMONG
THE GFS ENSEMBLES. HAVE SIDED MORE IN LINE WITH THE EC/GEM WHICH
KEEPS THE LOW IN THE VICINITY OF THE FOUR CORNERS THROUGH FRIDAY.
ALTHOUGH THE AIRMASS GRADUALLY TRENDS WARMER DURING THIS
TIME...MOIST AND SOMEWHAT UNSTABLE CONDITIONS WILL KEEP A THREAT
OF SHOWERS ACROSS THE AREA...MOSTLY ACROSS THE HIGHER TERRAIN.
PRECIPITATION IS NOT EXPECTED TO BE VERY HEAVY DUE TO
EAST/NORTHEAST FLOW BUT LONG DURATION OF THE EVENT COULD LEAD TO
SEVERAL INCHES LOCALLY. MOUNTAINS FARTHER SOUTH SUCH AS THE SAN
JUANS WILL BE CLOSER TO THE LOW AND RESULTING WEAKER FLOW COULD
ALLOW FOR BETTER ACCUMULATIONS.
THE LOW WILL FINALLY EXIT THE AREA OVER THE WEEKEND AND YIELD TO A
SLIGHTLY CYCLONIC NORTHWEST FLOW ALOFT. A GRADUAL WARMING TREND
WILL TAKE PLACE DURING THIS TIME AND INTO THE EARLY PART OF NEXT
WEEK. HOWEVER...MODELS CONTINUE TO GENERATE A FEW SHOWERS OVER
THE HIGH TERRAIN WITH WEAK RIPPLES EMBEDDED IN THE FLOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 411 PM MDT TUE APR 14 2015
WEST TO SOUTHWEST WINDS HAVE INCREASED THIS AFTERNOON AHEAD OF AN
APPROACHING COLD FRONT...WITH GUSTS OF 25-35 KTS WIDESPREAD ACROSS
THE FORECAST AREA. SOME ADDITIONAL INCREASE IN WINDS IS EXPECTED
DURING THE EARLY EVENING BEFORE THE FRONT PASSES THROUGH DURING
THE VERY LATE EVENING/EARLY MORNING HOURS. THE FRONT WILL CAUSE
WINDS TO ABRUPTLY SHIFT TO THE NORTH/NORTHWEST...WITH STRONG GUSTS
CONTINUING FOR A FEW HOURS BEHIND THE FRONT.
PRECIPITATION BEHIND THE FRONT IS EXPECTED TO BE SCATTERED IN
NATURE...BECOMING ALL SNOW AT HIGHER ELEVATIONS. PERIODS OF IFR
CONDITIONS CANNOT BE RULED OUT WITH ANY SHOWERS THAT MOVE OVER THE
TAF SITES.
&&
.FIRE WEATHER...
ISSUED AT 411 PM MDT TUE APR 14 2015
A RED FLAG WARNING HAS BEEN ISSUED THROUGH 9PM
FOR ALL WESTERN COLORADO ZONES BELOW 8000 FEET.
A STRONG COLD FRONT WILL APPROACH THE AREA OVERNIGHT INTO WEDNESDAY
MORNING. THIS WILL CONTINUE TO BRING STRONG WINDS TO MUCH OF THE
AREA...WITH WIND GUSTS UP TO 65 MPH POSSIBLE. THIS COLD FRONT WILL
REACH NORTHEASTERN UTAH LATER THIS EVENING...ARRIVING ACROSS SOUTH
CENTRAL COLORADO BY WEDNESDAY MORNING. EXPECT A SUBSTANTIAL DROP IN
TEMPERATURES WILL THIS FRONT ALONG WITH ISOLATED TO WIDELY SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS THE HIGHER TERRAIN. COOLER AND
UNSETTLED WEATHER REMAIN IN PLACE THROUGH THE END OF THE WEEK.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WIND ADVISORY UNTIL 3 AM MDT WEDNESDAY FOR COZ002-003-006>008-
011-020-021.
HIGH WIND WARNING UNTIL 3 AM MDT WEDNESDAY FOR COZ001-006.
FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY MORNING
FOR COZ001-006-011.
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR COZ200>203-205-
207-290-292.
UT...WIND ADVISORY UNTIL 3 AM MDT WEDNESDAY FOR UTZ023-025-028.
HIGH WIND WARNING UNTIL 3 AM MDT WEDNESDAY FOR UTZ022-024-027-
029.
FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY MORNING
FOR UTZ022-024-027-029.
&&
$$
SHORT TERM...LC
LONG TERM...LC
AVIATION...MT
FIRE WEATHER...CK
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1236 PM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL TRACK ACROSS THE REGION TODAY, WITH A WAVE OF LOW
PRESSURE PASSING BY TO OUR SOUTH ALONG THE DEPARTING BOUNDARY LATE
TODAY AND TONIGHT. AN AREA OF HIGH PRESSURE WILL THEN BUILD ACROSS
THE NORTHEAST AND MID ATLANTIC STATES THROUGH MIDWEEK. THIS HIGH
PRESSURE IS FORECAST TO MOVE OFFSHORE BY FRIDAY, ALLOWING UNSETTLED
WEATHER TO RETURN FOR THE END OF THE WEEK AND THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
12:30 PM UPDATE: MAXIMUM TEMPERATURES WERE TAPPED DOWN BY A DEGREE
OR SO TO ACCOUNT FOR THE STUBBORN CLOUD COVER OVER THE ENTIRE
FORECAST AREA. POPS HAVE ALSO BEEN REDUCED NORTH AND WEST OF THE
I-95 CORRIDOR WHERE RAIN HAS ENDED. THE HRRR CONTINUES TO INDICATE
A SLIGHT NORTHWARD MOVEMENT OF PRECIPITATION THIS AFTERNOON...BUT
THIS WAS DISCOUNTED IN FAVOR THE NAM AND GFS.
A COLD FRONT IS STILL EXPECTED TO SLOWLY SAG SOUTH THROUGH THE
DAY. A LOW PRESSURE SYSTEM IS EXPECTED TO DEVELOP ON THE FRONT,
BUT THIS SHOULD OCCUR ONCE IT IS SOUTH OF OUR REGION. THIS WILL
CONTINUE TO ENHANCE PRECIP OVER THE FAR SOUTHEASTERN PORTIONS OF
THE REGION THROUGH MID AFTERNOON. MODEL SOUNDINGS, ESPECIALLY THE
NAM, ARE SHOWING MODEST ELEVATED INSTABILITY OVER DELMARVA AND
EXTREME SOUTHERN NJ (UP TO 100 J/KG CAPE VALUES). THIS IS NOT
SURPRISING GIVEN THE LATER ARRIVAL OF THE FRONT. STILL, AS
SATURATED AS THE ENTIRE COLUMN WILL BE, AND AS ELEVATED AS THE
INSTABILITY WILL BE, THUNDERSTORMS SEEM VERY UNLIKELY, SO WILL
CONTINUE TO LEAVE OUT OF THE FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
PRECIP COULD LINGER THROUGH THE EARLY EVENING HOURS
ACROSS SOUTHERN DELMARVA, BUT OTHERWISE, SHOULD SEE DRY CONDITIONS
ACROSS MUCH OF THE REGION. ABOUT THE ONLY SIGNIFICANT CHANGE TO THE
FORECAST WAS TO INCREASE SKY COVER IN ANTICIPATION OF THICK CIRRUS
DEVELOPMENT AS THE UPPER LEVEL JET SLIDES EAST.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A QUIETER TREND IS EXPECTED AT THE BEGINNING OF THIS PERIOD AS
SURFACE HIGH PRESSURE CENTERED OVER SOUTHEASTERN CANADA WILL BE
BUILDING DOWN ACROSS THE NORTHEAST TO MID ATLANTIC STATES THROUGH
WEDNESDAY AND THURSDAY. WITH THE HIGH PRESSURE CENTERED TO OUR NORTH
THROUGH WEDNESDAY, AMPLE SUN WITH SLIGHTLY ABOVE AVERAGE
TEMPERATURES AND MODEST NORTHERLY WINDS ARE EXPECTED. MAXIMUM
TEMPERATURES ARE ANTICIPATED TO REACH THE MIDDLE TO UPPER 60S ACROSS
MOST OF THE REGION, WITH SOMEWHAT COOLER UPPER 50S TO NEAR 60 DEGREE
READINGS INTO THE POCONOS AND ALONG THE COASTS OF NEW JERSEY AND
DELAWARE. WHILE GENERALLY QUIET CONDITIONS ARE EXPECTED TO CONTINUE
INTO THURSDAY, THE CENTER OF THE SURFACE HIGH PRESSURE IS PROGGED TO
BE PASSING OFF THE COAST OF THE NORTHEAST STATES, AND THIS WILL
ALLOW FOR MORE OF AN EASTERLY SURFACE FLOW TO SET-UP ACROSS OUR
REGION, BRINGING A RETURN TO MORE CLOUDS AND DAYTIME TEMPERATURES
NEAR TO SLIGHTLY BELOW MID-APRIL AVERAGES. MAX TEMPS FOR THURSDAY
SHOULD BE MORE IN THE UPPER 50S TO LOWER 60S ACROSS THE REGION, WITH
COOLER LOW/MID 50S POSSIBLE INTO THE POCONOS AND ALONG THE COAST.
FROM HERE, A MORE UNSETTLED PATTERN IS EXPECTED TO CLOSE OUT THE
WEEK AND EXTEND THROUGH THE WEEKEND AND POSSIBLY MONDAY. WITH THE
PREVIOUSLY MENTIONED HIGH PRESSURE EAST AND OFFSHORE, A SHORTWAVE
UPPER-LEVEL TROUGH IS PROGGED TO PASS OVER THE REGION FRIDAY,
BRINGING SCATTERED RAIN SHOWERS. INTO THE WEEKEND AND MONDAY, THERE
CONTINUES TO BE A RATHER LARGE SPREAD OF MODEL SOLUTIONS REGARDING
THE TIMING, EVOLUTION, AND TRACK OF POSSIBLE LOW PRESSURE AND ITS
ASSOCIATED FRONTAL BOUNDARIES DEVELOPING AND MOVING IN A SPLIT FLOW
PATTERN. THIS LEADS TO GREATER UNCERTAINTY IN THE TIMING AND AMOUNT
OF PRECIPITATION THAT COULD AFFECT OUR FORECAST AREA OVER THE
WEEKEND AND INTO MONDAY. THEREFORE, WE MAINLY TOOK A BLEND OF WPC
GUIDANCE WITH CONTINUITY FOR THIS TIMEFRAME, WITH MAINLY CHANCE POPS
IN PLACE DURING THIS TIMEFRAME. FOR COMPARISON SAKE, THE LATEST
ECMWF WOULD HAVE A RELATIVELY DRY WEEKEND, WITH THE MAIN
PRECIPITATION EVENT GOING INTO MONDAY. MEANWHILE, THE GFS HAS DONE A
BIT OF A FLIP-FLOP, WITH SUNDAY INTO MONDAY NOW BEING THE WETTER
PERIOD AND SATURDAY BEING RELATIVELY DRY. AS WE GET CLOSER IN TIME
TO THE UPCOMING WEEKEND, MODEL RUNS WILL HOPEFULLY SHOW MORE
CONSISTENCY AND RESOLVE THE TIMING AND AMOUNT OF POTENTIAL PRECIP TO
AFFECT OUR AREA IN THE SPLIT FLOW PATTERN.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE,
KRDG, KILG, KMIV, KACY AND SURROUNDING AREAS.
THE COLD FRONT HAS NOW MOVED THROUGH ALL TAF SITES EXCEPT ACY AND
MIV, WITH VFR CONDITIONS RETURNING BEHIND THE FRONT. KMIV AND
KACY COULD SEE A FEW HOURS OF IFR CONDITIONS, AND SHRA LINGERING
FOR MUCH OF THE AFTERNOON. CONDITIONS SHOULD IMPROVE TO VFR
BETWEEN 18 AND 00Z, AND REMAIN VFR FOR THE REST OF THE TAF PERIOD.
OUTLOOK...
WEDNESDAY...VFR CONDITIONS ARE EXPECTED WITH NORTHERLY WINDS.
THURSDAY...CONTINUED VFR, WITH EASTERLY TO SOUTHEAST WINDS.
THURSDAY NIGHT AND FRIDAY...CONDITIONS LOWERING TO MVFR WITH
SCATTERED RAIN SHOWERS.
SATURDAY...SUB-VFR POSSIBLE IN ISOLATED/SCATTERED SHOWERS. LOW
CONFIDENCE.
&&
.MARINE...
SOUTHERLY WINDS WILL SHIFT ABRUPTLY TO NORTHWESTERLY WITH THE
ARRIVAL OF A COLD FRONT LATER TODAY. WIND GUSTS NEAR OR ABOVE 20KT
ARE POSSIBLE THROUGH THE EVENING AND OVERNIGHT HOURS. FOR THE
COASTAL WATERS FROM FENWICK ISLAND UP TO ATLANTIC CITY, SCA
CONDITIONS ARE LIKELY BEGINNING LATE TONIGHT. WAVES WILL SUBSEQUENTLY
INCREASE WITH THE WIND SPEED INCREASE.
OUTLOOK...
WEDNESDAY...WIND GUSTS TO AROUND 20 KNOTS AND SEAS AROUND 5 FEET ARE
EXPECTED TO CONTINUE FOR OUR SOUTHERN COASTAL WATERS FROM GREAT EGG
INLET SOUTH TO FENWICK ISLAND DE, AND A SMALL CRAFT ADVISORY LASTS
INTO EARLY AFTERNOON. OTHERWISE, WINDS AND SEAS ARE FORECAST TO BE
SUB-ADVISORY FOR THE REST OF THE COASTAL WATERS AND DELAWARE BAY.
THURSDAY...SUB-ADVISORY CONDITIONS ARE EXPECTED.
FRIDAY AND SATURDAY...MORE UNCERTAINTY EXISTS DURING THIS PERIOD,
BUT SEAS AT OR ABOVE 5 FT ARE POSSIBLE FOR THE COASTAL WATERS,
ESPECIALLY ON SATURDAY.
&&
.FIRE WEATHER...
FOR TODAY...LOCATIONS NORTH AND WEST OF THE FALL LINE,
INCLUDING LEHIGH VALLEY, NORTHWEST NJ, AND THE POCONOS, COULD SEE
MINIMUM AFTERNOON RELATIVE HUMIDITY VALUES NEAR 30 PERCENT. HOWEVER,
WITH WETTING RAINS EXPECTED THIS MORNING, AND WINDS GENERALLY LESS
THAN 10 MPH, NO FIRE WEATHER CONCERNS ARE ANTICIPATED AT THIS TIME.
FOR WEDNESDAY...WHILE RELATIVE HUMIDITY VALUES WILL LIKELY DROP INTO
THE 20S ACROSS MUCH OF THE AREA, WINDS ARE NOT EXPECTED TO
FREQUENTLY GUST ABOVE 20 MPH. IN ADDITION, MUCH OF THE REGION IS
EXPECTED TO RECEIVE WETTING RAINS DURING TUESDAY AND TUESDAY NIGHT,
WHICH SHOULD HELP TO MOISTEN THE FINE FUELS.
&&
.HYDROLOGY...
ACROSS DELMARVA AND SOUTHERN NEW JERSEY, GENERALLY ALONG AND
SOUTHEAST OF THE I95 CORRIDOR, STILL WATCHING FOR HEAVY RAIN
POTENTIAL FROM MID MORNING THROUGH LATE THIS AFTERNOON, ALTHOUGH
TIMING IS HIGHLY DEPENDENT ON HOW QUICKLY AND HOW FAR THE FRONT WILL
SLIDE SOUTH. NEAR THE FRONT, RELATIVELY HIGH MEAN RH, PWATS WELL
ABOVE NORMAL, AND A DEEP WARM CLOUD LAYER WILL ENHANCE THE HEAVY
RAIN THREAT. THE ONLY QUESTION IS HOW LONG THE THREAT WILL LAST. SO
FOR NOW, WILL KEEP THE SAME WORDING IN THE HWO.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM TO 2 PM EDT WEDNESDAY FOR
ANZ453>455.
&&
$$
SYNOPSIS...KLINE
NEAR TERM...GAINES/JOHNSON
SHORT TERM...JOHNSON
LONG TERM...KLINE
AVIATION...JOHNSON/KLINE
MARINE...JOHNSON/KLINE
FIRE WEATHER...
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS POCATELLO ID
1020 AM MDT TUE APR 14 2015
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT. THE MORNING NAM AND
ASSOCIATED HI-RES MODELS WERE SHOWING THE DEVELOPMENT OF A SNAKE
RIVER CONVERGENCE EVENT FROM POCATELLO TO IDAHO FALLS TONIGHT. THUS
UPDATED GOING FORECAST TO INCREASE SNOWFALL AND PRECIP POTENTIAL
ALONG AND EAST OF THE I-15 CORRIDOR AND ISSUED A WINTER WEATHER
ADVISORY. SEE PREVIOUS DISCUSSION BELOW. HUSTON
MODELS BEGINNING TO COME TO SOME AGREEMENT ON SYSTEM TODAY THROUGH
WEDNESDAY WHICH WILL BRING WIND AND SNOW TO SOUTHEAST IDAHO.
LATEST 06Z NAM CLOSES OFF NEGATIVE TILT 500 MILLIBAR TROF OVER
SOUTHERN IDAHO LATE TONIGHT AND MOVES IT INTO SOUTHWEST WYOMING
THROUGH WEDNESDAY MORNING. THE 00Z GFS WAS IN DECENT AGREEMENT NOW
ALSO CLOSING OFF UPPER LOW IN SOUTHERN IDAHO AND MOVING INTO
SOUTHWEST WYOMING THROUGH WEDNESDAY MORNING. THE EUROPEAN REMAINS
MUCH FURTHER SOUTH WITH THE UPPER LOW IN CENTRAL UTAH BY WEDNESDAY
MORNING AND ALSO SLOWER WITH MOVEMENT. THE INITIAL PROBLEM WILL BE
STRONG WINDS WITH THE COLD FRONT MOVING QUICKLY THROUGH EASTERN
IDAHO LATER THIS MORNING THROUGH EARLY AFTERNOON. KEPT WIND
WARNINGS AND ADVISORIES IN PLACE WITH MODELS SHOWING SOME 35 MPH
SUSTAINED WINDS IN MAGIC VALLEY AND SNAKE PLAIN AND SOUTH CENTRAL
HIGHLANDS. EXPECT SNOW TO DEVELOP BEHIND THE COLD FRONT INITIALLY
IN CENTRAL MOUNTAINS THIS MORNING THEN FOCUSED ON THE SOUTHERN AND
EASTERN HIGHLANDS AND SNAKE RIVER PLAIN OVERNIGHT TONIGHT. FOR NOW
CONTINUED WITH 1 TO 3 INCHES IN CENTRAL MOUNTAINS AND SNAKE RIVER
PLAIN WITH 4 TO 8 INCHES EXPECTED IN IDAHO WASATCH AND CARIBOU
HIGHLANDS WHERE A WINTER WEATHER ADVISORY REMAINS IN EFFECT THIS
AFTERNOON THROUGH WEDNESDAY MORNING. THE COMBINATION OF SNOW AND
WINDS WILL LIKELY PRODUCE SOME DIFFICULT DRIVING CONDITIONS THIS
AFTERNOON AND ESPECIALLY OVERNIGHT TONIGHT ONCE THE SUN SETS.
TEMPERATURES WILL TURN SHARPLY COLDER THIS AFTERNOON BEHIND THE
COLD FRONT AND REMAIN WELL BELOW NORMAL WEDNESDAY. EXPECT DRY AND
SUNNY CONDITIONS THURSDAY WITH A RETURN TO SEASONABLE TEMPERATURES.
GK
.LONG TERM...FRIDAY THROUGH NEXT MONDAY. MODELS CONSISTENT IN
DEVELOPING UPPER RIDGING INTO PAC NW THURSDAY NIGHT AS CUTOFF LOW
DROPS TO THE FOUR CORNERS AREA. A QUICK MOVING DISTURBANCE WILL
CROSS NORTHERN IDAHO AND MONTANA SATURDAY WITH LIMITED SHOWER
ACTIVITY IN THE UPPER SNAKE HIGHLANDS. THE MAIN CHANGE TO THE
FORECAST IS SATURDAY NIGHT AND SUNDAY WHERE THE SHARP RIDGE AXIS
CLOSE TO THE COAST RESULTS IN MORE NORTHERLY FLOW ALONG THE WYOMING
BORDER AND THUS SOME RISK OF LIGHT SHOWERS IN THE EASTERN HIGHLANDS.
RS
&&
.AVIATION....MOST NOTABLY FOR PIH AND IDA. KSFX RADAR VAD WINDS
SHOWS SOUTH WINDS 40-50 KTS CLOSE TO 2000 FEET OFF THE SURFACE AHEAD
OF A STRONG COLD FRONT. THE NAM12 AND HRRR MODELS HAVE THE TIGHT
SURFACE PRESSURE GRADIENT OVER MALAD AND BEAR LAKE AREA SHIFTING
EAST BY 12Z THIS MORNING. THAT WOULD FAVOR THE CURRENT THREAT OF
LLWS ENDING 1 TO 2 HOURS AHEAD OF THE CURRENT TAF TIMING. PASSAGE OF
THE FRONT AT KPIH SHOULD BE NEAR 14Z. VERY IMPRESSIVE SURFACE POST
FRONTAL PRESSURE GRADIENT TODAY. HIGH WIND WARNING IN EFFECT FROM
NOON TO 15/04Z. ALL 3 SNAKE PLAIN TAF SITES ARE INCLUDED. SNOW
LEVELS FALL TO VALLEY FLOORS OVERNIGHT WHICH BRINGS SNOW SHOWERS
WITH MVFR CEILINGS AT KIDA AND KPIH 15/04-09Z.
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING FROM NOON TODAY TO 10 PM MDT THIS EVENING
IDZ017-021-022.
WIND ADVISORY FROM NOON TODAY TO 10 PM MDT THIS EVENING IDZ020.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON MDT
WEDNESDAY ABOVE 5500 FEET FOR THE IDZ023-025.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 4 AM WEDNESDAY
MORNING IDZ020-021.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
345 PM EDT TUE APR 14 2015
.UPDATE...
ISSUED AT 345 PM EDT TUE APR 14 2015
GIVEN THAT MUCH OF THE RAIN HAS SUBSIDED ACROSS THE REGION WE HAVE
DROPPED THE FLOOD WATCH FOR THE REGION. ONGOING FLOODING WILL BE
COVERED BY FLOOD WARNINGS AND ADVISORIES.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM EDT TUE APR 14 2015
SURFACE ANALYSIS SHOWS A BROADER AREA OF SURFACE LOW PRESSURE
CENTERED JUST TO THE SOUTH ACROSS EASTERN TENNESSEE THIS
AFTERNOON. THIS ALONG WITH A FRONTAL BOUNDARY HAS BEEN THE FOCAL
POINT OF LIFT FOR THE RAINFALL THAT HAS OCCURRED TODAY. LATEST
WSR- 88D RADAR AT 3 PM DOES INDICATE THAT MUCH OF OF THE HEAVIER
RAINFALL HAS WANED THIS AFTERNOON. THIS AREA OF LOW PRESSURE IS
EXPECTED TO PROGRESS EAST INTO THE CAROLINAS AS WE MOVE TONIGHT
ALONG WITH THE RAINFALL.
THE QUESTION THAT REMAINS FOR OVERNIGHT HOURS IS WHAT WILL HAPPEN
WITH YET ANOTHER UPPER LEVEL WAVE TRACKING NORTHEAST OUT OF THE
LOWER MISSISSIPPI RIVER VALLEY. SOME OF THE MESOSCALE MODELS SUCH
AS THE HRRR AND RAP WOULD SUGGEST WE WILL GET AT LEAST CLIPPED BY
THIS AREA OF RAIN ASSOCIATED WITH THE WAVE. RIGHT NOW WE ARE
CARRYING SLIGHT TO CHANCE POPS WITH HIGHER POPS ACROSS SOUTHEAST
KENTUCKY. THESE POPS COULD NEED TO BE HIGHER LATE EVENING INTO THE
OVERNIGHT DEPENDING ON THE PROPAGATION OF THIS WAVE OF ENERGY.
UNDER THIS GENERAL SOUTHWEST FLOW ALOFT WILL BRING YET ANOTHER
UPPER LEVEL SHORTWAVE AS WE MOVE INTO LATER WEDNESDAY INTO
WEDNESDAY NIGHT. THIS WILL BRING ANOTHER ROUND INCREASED ROUND OF
SHOWERS FROM SOUTHWEST TO NORTHEAST OVERNIGHT WEDNESDAY AS THIS
WAVE TRACKS NORTHEAST AND DIFFLUENCE ALOFT IN PLACE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 335 PM EDT TUE APR 14 2015
THE UPPER LEVEL PATTERN SHOWS NORTHERN STREAM FLOW SITUATED ALONG
THE CANADIAN/US BORDER THROUGH THE EXTENDED PERIOD...WHILE THE
EASTERN US IS DOMINATED BY RIDGING AND THE WESTERN US IS DOMINATED
BY A SPLIT FLOW WITH A CUT OFF LOW IN THE SOUTHERN STREAM. A SERIES
OF DISTURBANCES WILL EJECT OUT OF THE SOUTHERN STREAM AND PASS
THROUGH THE TN AND OH VALLEYS DURING THE LATTER HALF OF THE WORK
WEEK...BRINGING PRECIPITATION...POSSIBLY HEAVY AT TIMES.
SUNDAY...THE CUT OFF LOW IS PROGGED TO LIFT OUT OF THE SRN STREAM
AND MERGE WITH A NORTHERN STREAM UL TROUGH WHICH ENDS UP TURNING
INTO A LARGE ROBUST SYSTEM. THIS SYSTEM IS PROGGED TO SPREAD
PRECIPITATION OVER THE NORTHERN PLAINS/UPPER MISSISSIPPI VALLEY
SOUTHWARD ACROSS OUR REGION AND INTO THE SOUTHEASTERN US FROM
SUNDAY AFTERNOON THROUGH LATE MONDAY NIGHT. THE UL PATTERN IS
THEN DOMINATED BY THE UL TROUGH WHICH SLOWLY MOVES ALONG THE
US/CANADIAN BORDER...NORTH OF THE GREAT LAKES...THROUGH THE END
OF THE EXTENDED PERIOD. THIS WILL ALLOW FOR TEMPERATURES TO DROP
BACK DOWN TO SEASONABLE LEVELS NEXT TUES/WED AND POSSIBLY BRING A
SHORT BREAK TO THE WET WEATHER.
AT THE SFC...THE UL DISTURBANCES WILL BRING CONTINUED CHANCES FOR
RAIN THURSDAY THROUGH LATE MONDAY. THERE MAY BE MOMENTARY BREAKS
IN THE RAIN ON SATURDAY BUT OVERALL THIS WILL BE ANOTHER WET
PERIOD WITH ABOVE AVERAGE RAINFALL. SOUTHERLY FLOW WILL ALSO
PERSIST...USHERING IN WARM MOIST AIR...WHICH ENHANCES THE RAIN
POTENTIAL THROUGH THE PERIOD. MODEL SOUNDINGS SHOW PW VALUES
FLUCTUATE BETWEEN 1.0" AND 1.4" DURING THIS PERIOD...WHICH IS WELL
ABOVE THE 2 STANDARD DEVIATIONS ABOVE NORMAL. BY LATE MONDAY/EARLY
TUESDAY...THE UL TROUGH SHOULD FINALLY PUSH EAST...PROVIDING
ANOTHER BREAK IN RAINFALL BY TUESDAY AFTERNOON.
THERE ARE SUBSTANTIAL DIFFERENCES BETWEEN THE GFS AND
ECMWF...ESPECIALLY DURING THE WEEKEND PERIOD AND BEYOND. SO HAVE
STUCK CLOSE TO THE CR SUPERBLEND FOR THE MAJORITY OF THE EXTENDED
PERIOD. ALSO KEPT SLIGHT CHANCE FOR THUNDER THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 146 PM EDT TUE APR 14 2015
STILL SOME AREAS OF LIGHT TO MODERATE RAIN MOVING ACROSS PORTIONS
OF EASTERN KENTUCKY THIS AFTERNOON. THE COVERAGE HAS DROPPED OFF
AS WE HAVE MOVE THROUGH THE DAY. UPSTREAM OBS WOULD SUGGEST A
REPRIEVE IN THE IFR CEILINGS THIS AFTERNOON...HOWEVER IT DOES
LOOK LIKE WE WILL SEE A DECREASE BACK TO IFR AS WE MOVE INTO THE
EVENING AND OVERNIGHT. THERE WILL BE A BIT OF A GRADIENT AS THE
LOW PRESSURE PASSES TO NEAR THE TN BORDER. THIS WILL ALLOW FOR
SOME GUSTY WINDS WHICH ARE ALREADY BEING SEEN AT SYM THIS HOUR.
THESE WIND WILL SUBSIDE AS WE MOVE INTO THE EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...DJ
LONG TERM...JVM
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
336 PM EDT TUE APR 14 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM EDT TUE APR 14 2015
SURFACE ANALYSIS SHOWS A BROADER AREA OF SURFACE LOW PRESSURE
CENTERED JUST TO THE SOUTH ACROSS EASTERN TENNESSEE THIS
AFTERNOON. THIS ALONG WITH A FRONTAL BOUNDARY HAS BEEN THE FOCAL
POINT OF LIFT FOR THE RAINFALL THAT HAS OCCURRED TODAY. LATEST
WSR- 88D RADAR AT 3 PM DOES INDICATE THAT MUCH OF OF THE HEAVIER
RAINFALL HAS WANED THIS AFTERNOON. THIS AREA OF LOW PRESSURE IS
EXPECTED TO PROGRESS EAST INTO THE CAROLINAS AS WE MOVE TONIGHT
ALONG WITH THE RAINFALL.
THE QUESTION THAT REMAINS FOR OVERNIGHT HOURS IS WHAT WILL HAPPEN
WITH YET ANOTHER UPPER LEVEL WAVE TRACKING NORTHEAST OUT OF THE
LOWER MISSISSIPPI RIVER VALLEY. SOME OF THE MESOSCALE MODELS SUCH
AS THE HRRR AND RAP WOULD SUGGEST WE WILL GET AT LEAST CLIPPED BY
THIS AREA OF RAIN ASSOCIATED WITH THE WAVE. RIGHT NOW WE ARE
CARRYING SLIGHT TO CHANCE POPS WITH HIGHER POPS ACROSS SOUTHEAST
KENTUCKY. THESE POPS COULD NEED TO BE HIGHER LATE EVENING INTO THE
OVERNIGHT DEPENDING ON THE PROPAGATION OF THIS WAVE OF ENERGY.
UNDER THIS GENERAL SOUTHWEST FLOW ALOFT WILL BRING YET ANOTHER
UPPER LEVEL SHORTWAVE AS WE MOVE INTO LATER WEDNESDAY INTO
WEDNESDAY NIGHT. THIS WILL BRING ANOTHER ROUND INCREASED ROUND OF
SHOWERS FROM SOUTHWEST TO NORTHEAST OVERNIGHT WEDNESDAY AS THIS
WAVE TRACKS NORTHEAST AND DIFFLUENCE ALOFT IN PLACE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 335 PM EDT TUE APR 14 2015
THE UPPER LEVEL PATTERN SHOWS NORTHERN STREAM FLOW SITUATED ALONG
THE CANADIAN/US BORDER THROUGH THE EXTENDED PERIOD...WHILE THE
EASTERN US IS DOMINATED BY RIDGING AND THE WESTERN US IS DOMINATED
BY A SPLIT FLOW WITH A CUT OFF LOW IN THE SOUTHERN STREAM. A SERIES
OF DISTURBANCES WILL EJECT OUT OF THE SOUTHERN STREAM AND PASS
THROUGH THE TN AND OH VALLEYS DURING THE LATTER HALF OF THE WORK
WEEK...BRINGING PRECIPITATION...POSSIBLY HEAVY AT TIMES.
SUNDAY...THE CUT OFF LOW IS PROGGED TO LIFT OUT OF THE SRN STREAM
AND MERGE WITH A NORTHERN STREAM UL TROUGH WHICH ENDS UP TURNING
INTO A LARGE ROBUST SYSTEM. THIS SYSTEM IS PROGGED TO SPREAD
PRECIPITATION OVER THE NORTHERN PLAINS/UPPER MISSISSIPPI VALLEY
SOUTHWARD ACROSS OUR REGION AND INTO THE SOUTHEASTERN US FROM
SUNDAY AFTERNOON THROUGH LATE MONDAY NIGHT. THE UL PATTERN IS
THEN DOMINATED BY THE UL TROUGH WHICH SLOWLY MOVES ALONG THE
US/CANADIAN BORDER...NORTH OF THE GREAT LAKES...THROUGH THE END
OF THE EXTENDED PERIOD. THIS WILL ALLOW FOR TEMPERATURES TO DROP
BACK DOWN TO SEASONABLE LEVELS NEXT TUES/WED AND POSSIBLY BRING A
SHORT BREAK TO THE WET WEATHER.
AT THE SFC...THE UL DISTURBANCES WILL BRING CONTINUED CHANCES FOR
RAIN THURSDAY THROUGH LATE MONDAY. THERE MAY BE MOMENTARY BREAKS
IN THE RAIN ON SATURDAY BUT OVERALL THIS WILL BE ANOTHER WET
PERIOD WITH ABOVE AVERAGE RAINFALL. SOUTHERLY FLOW WILL ALSO
PERSIST...USHERING IN WARM MOIST AIR...WHICH ENHANCES THE RAIN
POTENTIAL THROUGH THE PERIOD. MODEL SOUNDINGS SHOW PW VALUES
FLUCTUATE BETWEEN 1.0" AND 1.4" DURING THIS PERIOD...WHICH IS WELL
ABOVE THE 2 STANDARD DEVIATIONS ABOVE NORMAL. BY LATE MONDAY/EARLY
TUESDAY...THE UL TROUGH SHOULD FINALLY PUSH EAST...PROVIDING
ANOTHER BREAK IN RAINFALL BY TUESDAY AFTERNOON.
THERE ARE SUBSTANTIAL DIFFERENCES BETWEEN THE GFS AND
ECMWF...ESPECIALLY DURING THE WEEKEND PERIOD AND BEYOND. SO HAVE
STUCK CLOSE TO THE CR SUPERBLEND FOR THE MAJORITY OF THE EXTENDED
PERIOD. ALSO KEPT SLIGHT CHANCE FOR THUNDER THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 146 PM EDT TUE APR 14 2015
STILL SOME AREAS OF LIGHT TO MODERATE RAIN MOVING ACROSS PORTIONS
OF EASTERN KENTUCKY THIS AFTERNOON. THE COVERAGE HAS DROPPED OFF
AS WE HAVE MOVE THROUGH THE DAY. UPSTREAM OBS WOULD SUGGEST A
REPRIEVE IN THE IFR CEILINGS THIS AFTERNOON...HOWEVER IT DOES
LOOK LIKE WE WILL SEE A DECREASE BACK TO IFR AS WE MOVE INTO THE
EVENING AND OVERNIGHT. THERE WILL BE A BIT OF A GRADIENT AS THE
LOW PRESSURE PASSES TO NEAR THE TN BORDER. THIS WILL ALLOW FOR
SOME GUSTY WINDS WHICH ARE ALREADY BEING SEEN AT SYM THIS HOUR.
THESE WIND WILL SUBSIDE AS WE MOVE INTO THE EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH UNTIL 5 PM EDT THIS AFTERNOON FOR KYZ080-084>088-104-
106>120.
&&
$$
SHORT TERM...DJ
LONG TERM...JVM
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1250 PM EDT Tue Apr 14 2015
...Updated Aviation Discussion...
...Forecast Update...
Issued at 1035 AM EDT Tue Apr 14 2015
Band continues over southern Indiana, but also still have some light
to moderate rains over Kentucky. Pattern resembles a setup that
would generate a lot of snow in the winter, but fortunately we are
20-30 degrees warmer! Despite the lifting of the shortwave, into
Indiana now, we still have quite a bit of low-level lift to deal
with for a few more hours, so have raised pops some more into the
afternoon hours.
As for the Flood Watch, will let that expire at 15Z as planned.
Already have upgraded to areal flood warnings in most of the watch
locations, so no more need for a double product. Will update the
zones at 15Z to remove that headline.
Issued at 930 AM EDT Tue Apr 14 2015
Heaviest band of precip has lifted north into southern Indiana, but
continue with moderate rains over our east and southeast counties.
Areal flood warnings are out with several reports of water over
roads coming in for those areas. We should not have such a problem
over the north, but will keep watch over the next hour or two until
the shortwave noted on water vapor imagery kicks out of here and the
forcing for these rains dies down.
Issued at 650 AM EDT Tue Apr 14 2015
Just a quick update on latest trends. Widespread rain continues at
this time over most of central KY as the mid-level shortwave heads
northeast across western TN at this time. Pockets of moderate to
heavy rain are occurring throughout the region. This could cause
significant ponding of water on some roads and low-lying areas, and
some creeks could possibly overflow. However, have received no
reports of flooding at this time.
06z models and latest HRRR reflecting radar trends well. The sharp
northern edge of the rain along and south of the OH River has
relaxed some and spread a bit farther north as expected. A few
heavier rain elements are now showing up near Evansville and just
northeast of Louisville. The heaviest steadiest rains will remain
within the Flood Watch area, but showers will spread northeast
across much of south-central IN over the next hour or two.
Otherwise, forecast is on track with just some tweaks to hourly POPs
to match latest trends.
.SHORT TERM (Now through Wednesday)...
Issued at 315 AM EDT Tue Apr 14 2015
...Flood Watch continues this morning for parts of central KY...
A solid area of rain has evolved in a WSW-ENE axis across central
KY early this morning, ahead of a pronounced shortwave in water
vapor imagery moving from AR/MS into western TN and an associated
surface low pressure system. Within this rain are numerous areas of
moderate rain. At this time, there is a distinct northern boundary
to the rain along and just south of the OH River associated with a
deformation zone. The latest few HRRR runs have shown that rain just
ahead of the shortwave may move a little farther north and be slower
to depart than previous forecasts, which the 00z NAM also hinted at.
These models are slower and farther north than the 00z GFS, which
seems reasonable. Thus, despite the current tight northern precip
edge, more showers should move back across the Louisville metro and
into at least parts of south-central IN later this morning,
continuing during much of the morning. However, the heaviest rain
should continue to fall out in an axis to the east of the shortwave.
The current Flood Watch looks good, although decent rains will fall
a county or so north of the Watch as well, but will keep the area
unchanged at this time. The overall trend should be for more bands
of showers to form east of the shortwave then rotate north and east.
This should keep highest rainfall totals in an axis from about BWG
to LEX and a row of counties or so south. Still looks like 1 to 2
inches of rain is a good bet in this axis, with locally 2+ inches
possible in a few spots. However, since rainfall is not truly
convective and since rain rates should not increase much more than
at present, widespread flash flooding is not likely. Instead,
significant ponding and some areal flooding of roads, low-lying
areas, creeks, and small streams may occur. Slightly lower rain
totals are expected over our extreme southeast south-central KY
counties. While showers will continue past the 15 UTC expiration
time of the Watch, will not change it at this time. This can be
locally extended if need be later this morning pending latest trends
and reports.
Rainfall will diminish this afternoon for most areas, but scattered
showers should continue over our east and southeast counties
overcast skies persist. Over south-central IN, some breaks in the
clouds could occur later this afternoon.
High temperatures today are tricky. Values at this time may not go
up much if any today. Matter of fact, could see readings fall a bit
as a brisk northeast wind develops along with the low clouds and
showers in parts of central KY. Will keep readings in the upper 50s
over much of east-central KY west-southwestward, with lower-mid 60s
for south-central KY, again with highest values this morning. Also,
expect lower-mid 60s in south-central IN where low clouds will scour
out and showers will end this afternoon. Lows tonight should range
from the mid 40s to lower 50s with a cloudy sky south and east, and
partly to mostly cloudy north and west.
On Wednesday, mid-level flow will begin to back again, resulting in
clouds moving back northward. There could be some scattered showers
especially across south-central KY, although there are no clear
forcing mechanics at this time. Expect highs in the mid 60s to lower
70s.
.LONG TERM (Wednesday Night through Monday)...
Issued at 325 AM EDT Tue Apr 14 2015
...Above Normal Rainfall Expected This Week...
In general terms, there is not a whole lot of change in the guidance
for the extended forecast period. The synoptic flow aloft will be
characterized by a fast northern jet flow confined to the
US/Canadian border region, while a split flow pattern will be in
place across the western US with a cut off low in the southern
stream. Multiple wave packets will eject out of the southern stream
and pass through the region in the mid-late part of the week,
bringing precipitation with the potential for heavy rainfall. By
late in the period, the cut off low over the SW US is expected to
lift out and merge with a northern stream wave which looks to turn
into a rather large gyre over the northern Great Lakes by early next
week. This would bring drier and cooler than normal conditions to
the region.
It does appear that we`ll see the first wave push through the region
on Thursday with a secondary wave coming in Friday night and early
Saturday. Combination of lift with the associated waves and plenty
of Gulf moisture will lead to widespread rainfall, some heavy, which
could result in renewed hydrologic concerns through the period.
This would be especially true across our southern half of the
forecast area...mainly south of the Parkways. The weekend does not
look to be an entire wash out, but Saturday morning will probably
remain a bit unsettled as the aforementioned wave ejects through the
region. There is a growing consensus in the data that upper level
ridging will build in during the afternoon to allow the region to
dry out a bit. Thus, will continue to run chance PoPs in the
forecast for the early part of Saturday and then allow PoPs to
decrease throughout the remainder of the day and into Sunday.
As the upper low out over the southwest US lifts out and combines
with the northern stream wave pushing through, we should see a
return of wet weather as we head into late Sunday and Monday. More
showers with some thunderstorms looks likely.
As for temperatures, have generally stuck close to the SuperBlend
consensus guidance for temperatures. This will result in daytime
highs generally in the upper 60s to the lower 70s for highs and
overnight lows in the 50s. These temperature forecasts will likely
see some sort of modulation in subsequent forecasts as the timing
issues in the upper level waves moving through the area become more
clearly defined in the coming days.
&&
.AVIATION (18Z TAF Update)...
Updated at 1245 PM EDT Tue Apr 14 2015
Conditions slowly improving at area sites, as upper forcing for this
morning`s rains lifts quickly northeast. Enough moisture fell though
over south central KY to keep the forecast pessimistic for KBWG.
KSDF/KLEX are looking better in current obs, so just have a few more
hours of light rain. High pressure will move across the Great Lakes
this afternoon and tonight, keeping a general northeasterly winds
this period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Updates........RJS/TWF
Short Term.....TWF
Long Term......MJ
Aviation.......RJS
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
316 PM CDT Tue Apr 14 2015
.DISCUSSION...
Issued at 316 PM CDT TUE APR 14 2015
A slow moving upper-level low is meandering northeast through Kansas
based on latest satellite and radar imagery. This is resulting in
isolated to scattered showers over southern Missouri to
slowly lift northward. This trend will continue tonight and arranged
PoPs to build north from late this afternoon through the overnight.
Chances still look rather low and have kept PoPs below 30% through
the night and into the day Wednesday. Short-range higher resolution
models, like the WRF-ARW and NMM as well as the RUC and HRRR all show
relatively spotty shower activity through the night. But overall,
isolated to scattered showers are expected to build northward tonight
and then shift east through the day tomorrow as the upper-level low
opens up and moves away to the east.
The focus will then shift to the large upper-level trough building
into the Intermountain West. First, there is considerable
uncertainty with how this system will evolve and this is mainly due
to the potential for it to cut off and get stuck between the polar
jet to the north and the subtropical jet to the south. This is the
scenario the ECMWF and the GEM depict. However, GFS is not as strong
with the cutting off and as a result pushes east quicker. That said,
it looks like this system will remain to our west through at least
the end of the week, and possibly into the early part of next week,
allowing for southerly low-level flow to build moisture northward.
This means we`ll see the chances for showers and thunderstorms
through much, if not all of, the extended portion of the forecast.
It doesn`t look like we`ll see any widespread precipitation on any
given day, rather isolated to scattered showers and storms.
Additionally, the threat of severe weather looks low for our area as
there never really seems to be aligning of instability with
stronger shear.
Regarding temperatures, with increased cloud coverage/ precipitation
potential for each day, highs look to be fairly close to normal with
temperatures in the upper 60s to lower 70s. Later in the period, as
the upper low is expected to be closer to the region, temperatures
may top out in the mid to upper 60s. The normal high for the Kansas
City area through this period is in the upper 60s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1159 AM CDT TUE APR 14 2015
VFR conditions will prevail through the afternoon hours as surface
high pressure exits the area. Overnight, building cloud cover and
light precipitation will develop ahead of a closed low to the
southwest. This will linger through the remainder of the forecast
period as the low center slowly moves north. Ceilings may become MVFR
at times as this system works its way through the area. Winds will
generally stay out of the southeast between 5-8 kts.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...CDB
AVIATION...Welsh
AREA FORECAST DISCUSSION
NWS BILLINGS MT
313 PM MDT TUE APR 14 2015
.SHORT TERM...VALID FOR WED AND THU...
THE NEXT 24 HOURS WILL HAVE UNSEASONABLE WARMTH...CRITICAL FIRE
WEATHER CONDITIONS...A LOW-END CHANCE OF A THUNDERSTORM...WINDS
GUSTING OVER 50 MPH...AND FINALLY SNOW. SPRINGTIME AT ITS BEST.
AS OF 3 PM MDT...DEEPENING MIXING IS YIELDING RED FLAG CONDITIONS
ACROSS MUCH OF THE AREA AND THIS WILL CONTINUE INTO THIS EVENING.
THE MUCH-ADVERTISED STRONG COLD FRONT IS GAINING STEAM AND HAS
JUST PASSED BOZEMAN. MULTI-RUN HRRR SIMULATIONS AND OTHER 12 UTC
HIGH-RESOLUTION AND EVEN GLOBAL MODEL GUIDANCE SUGGESTS THE FRONT
WILL PASS THROUGH LIVINGSTON BY LATE AFTERNOON...BILLINGS BETWEEN
6 AND 8 PM MDT...SHERIDAN AND MILES CITY BETWEEN 9 PM AND 11 PM
MDT...AND FINALLY BAKER AND EKALAKA BETWEEN 1 AM AND 3 AM MDT. WE
EXPECT STRONG POST-FRONTAL NORTHWEST WINDS BEHIND THE FRONT GIVEN
STRONG LOW-LEVEL COLD AIR ADVECTION AND PRESSURE RISES. THE SNAP-
EFFECT SEEN IN MODELED 850-MB ISOTHERMS WITH A FRONTAL PASSAGE IS
OFTEN A GOOD SIGNATURE OF 40+ MPH GUSTS AND GIVEN THE STRENGTH OF
THE ISOTHERM PACKING IN THIS SCENARIO GUSTS SHOULD BE QUITE A BIT
HIGHER THAN THAT. HRRR WIND GUST SIMULATIONS KEEP SPEEDS UNDER 60
MPH SO WE HAVE REFRAINED FROM ISSUING A HIGH WIND WARNING AT THIS
JUNCTURE...BUT WE HAVE GUSTS TO 55 MPH IN OUR FORECAST AND WE ARE
EXPECTING THIS TO BE A DRAMATIC CHANGE WITH POTENTIAL IMPACTS TO
CONSTRUCTION SITES AND OTHER SPRING PROJECTS. THUS...WE WILL BE
MESSAGING THE STRONG WINDS TO THE PUBLIC AND OUR PARTNERS AND IF
LATER TRENDS SUGGEST EVEN STRONGER WINDS WE MIGHT STILL NEED TO
ISSUE A HIGH WIND WARNING OVER PARTS OF THE AREA FOR THE EVENING.
THE BOUNDARY LAYER IS TOO DRY TO SUPPORT MUCH BUOYANCY DESPITE
ITS STEEP LAPSE RATES...SO WE ARE EXPECTING ALL OF THE RAIN AND
SNOW TO BE POST-FRONTAL. SHOWERS WILL FILL IN BEHIND THE FRONT AS
FORCING FOR ASCENT INCREASES ALOFT AND A THUNDERSTORM IS POSSIBLE
AS WELL THIS EVENING GIVEN STEEP MID-LEVEL LAPSE RATES...BUT WE
FEEL THE PROBABILITY OF MORE THAN A SHORT-LIVED STORM IS RATHER
LOW. CONVECTIVE OUTFLOW COULD ALSO ENHANCE WINDS...EVEN IF IT IS
MAINLY IN THE FORM OF NON-THUNDER-SHOWERS...BUT GUIDANCE SUGGESTS
THERE WILL BE A LAG BEHIND THE LOW-LEVEL FRONTAL SURGE AND SHOWER
DEVELOPMENT /WHICH IS REASONABLE GIVEN THE ANTECEDENT DRY AIR
MASS/. THUS...OUTFLOW MAY NOT HAVE MUCH ADDITIONAL IMPACT ON
INCREASING WINDS THAN IF SHOWERS FORMED RIGHT ON THE FRONT. WE
WILL WATCH RADAR TRENDS TO SEE IF THEY DO MANAGE TO FORM CLOSE TO
THE SURFACE FRONTAL SURGE THOUGH...WHICH COULD TIP THE SCALES TO A
MORE BONAFIDE HIGH WIND EVENT.
REGARDLESS...SHOWERS WILL LIKELY FILL IN OVER SOUTH CENTRAL MT AND
NORTH CENTRAL WY OVERNIGHT AND LINGER INTO WEDNESDAY AND WE STILL
EXPECT A QUICK CHANGE-OVER TO SNOW. A FEW INCHES OF WET SNOW WILL
LIKELY ACCUMULATE IN AND NEAR THE FOOTHILLS AND SO WE HAVE WINTER
WEATHER ADVISORIES IN PLACE THERE. WE ALSO ADDED A WINTER WEATHER
ADVISORY INTO SOUTHERN BIG HORN AND SHERIDAN COUNTIES SINCE THOSE
AREAS WILL LIKELY RECEIVE SOME UPSLOPE ENHANCEMENT TO SNOWFALL. WE
AGAIN LEANED TOWARD THE SOMEWHAT DRIER SIDE OF MODEL OUTPUT TODAY.
HOWEVER...THERE IS ENOUGH CONSISTENCY IN EVEN THE DRIER AND LIKELY
MORE REALISTIC MODEL SOLUTIONS FOR US TO EXPECT SOME ACCUMULATIONS
OF WET SNOW OVER PARTS OF THE AREA. ROADS COULD HAVE SOME IMPACTS
LATE TONIGHT AND WEDNESDAY MORNING WHERE IT SNOWS THE HARDEST OVER
THE FOOTHILLS TOO...BUT OTHER SPOTS AWAY FROM THE FOOTHILLS WHERE
PRECIPITATION INTENSITY IS LIKELY TO BE LESS WILL LIKELY ONLY GET
SNOWFALL ON GRASSY SURFACES. THAT WOULD INCLUDE BILLINGS...WHERE
WE HAVE 1 TO MAYBE 2 INCHES OF SNOW IN THE OFFICIAL FORECAST WITH
THE IDEA THAT ROADS WILL ONLY BE WET EVEN IF IT DOES SNOW AS
FORECAST.
FINALLY...WE COMPLETELY SET ASIDE THE 12 UTC GFS SOLUTION HEADING
INTO WEDNESDAY AND THURSDAY SINCE IT IS A DISTINCT OUTLIER FROM
ALL OTHER MODEL OUTPUT IN CLOSING OFF A SEPARATE...NORTHERN-STREAM
CLOSED MID- AND UPPER-LEVEL LOW IN NORTHEAST WY AND NORTHWEST SD
BY WEDNESDAY EVENING. THAT SIMULATION ACTUALLY YIELDS VERY HEAVY
AND WET SNOW OVER SOUTHEASTERN MT...BUT AGAIN WE HAVE DISCOUNTED
THAT POSSIBILITY FOR NOW SINCE IT HAS NO SUPPORT IN OTHER MODEL
GUIDANCE. SOUTHEASTERN MT MAY WELL GET SOME LIGHT RAIN OR SNOW AS
SHOWN EVEN IN THE PREFERRED 12 UTC NAM AND ECMWF SOLUTIONS...BUT
WE DON/T FORESEE A WARNING-LEVEL EVENT IN THAT AREA LIKE THE GFS
WOULD HAVE US BELIEVE. SCHULTZ
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
MODELS ARE NOT IN THE BEST AGREEMENT FRIDAY AS THEY ARE STILL
TRYING TO RESOLVE DIFFERENCES FROM THE WEDNESDAY/THURSDAY STORM
SYSTEM MOVING OUT OF THE CENTRAL AND NORTHERN ROCKIES. BUT IN
GENERAL...CONDITIONS LOOK TO BE DRY BUT DIFFERENCES IN THE UPPER
LEVEL FLOW ARE RESULTING IN AFTERNOON TEMPERATURE DISCREPANCIES.
AS A RESULT...WILL TAKE A BLEND OF THE MODELS KEEPING READINGS IN
THE LOWER TO MIDDLE 60S FOR NOW.
SATURDAY INTO SUNDAY...LEE-SIDE TROUGHING SETS UP FRIDAY NIGHT
CONTINUING INTO SATURDAY AHEAD OF ANOTHER COLD FRONT THAT WILL
SWEEP ACROSS THE FORECAST AREA DURING THE AFTERNOON. SATURDAY
LOOKS TO BE THE WARMEST DAY IN THE EXTENDED DUE TO PRE-FRONTAL
WARMING. EXPECT GUSTY NORTHWEST WINDS TO USHER IN BEHIND THE FRONT
SATURDAY NIGHT INTO SUNDAY. THE FRONT WILL BRING A QUICK SHOT OF
SHOWERS WITH THE HIGHEST CHANCES ALONG THE BEARTOOTH/ABSAROKA
FOOTHILLS SOUTHEAST TO THE BIG HORN FOOTHILLS...AS WELL AS FAVORED
UPSLOPE AREAS OF SOUTHERN BIG HORN COUNTY EAST AND SOUTH INTO
POWDER RIVER AND SHERIDAN COUNTIES.
SUNDAY INTO EARLY NEXT WEEK...A LARGE UPPER LOW OVER THE HUDSON
BAY AREA WILL RESULT IN A CYCLONIC FLOW ACROSS THE EASTERN HALF
OF MONTANA. THIS WILL BRING THE POSSIBILITY OF REINFORCING COLD
FRONTS SOUTH OUT OF CANADA ACROSS THE FORECAST AREA ESPECIALLY
EAST TOWARD THE DAKOTA BORDERS. OVERALL...AFTER SUNDAY...SHOWER
CHANCES WILL BE MINIMAL WITH TEMPERATURES AROUND NORMAL FOR THIS
TIME OF YEAR. HOOLEY
&&
.AVIATION...
A STRONG COLD FRONT WILL MOVE ACROSS THE FORECAST AREA THIS
EVENING INTO THE EARLY MORNING HOURS LATE TONIGHT. THE FRONT IS
EXPECTED TO MOVE THROUGH KLVM AROUND 22Z...KBIL AROUND 01Z...KMLS
AROUND 05Z AND FAR SOUTHEAST MONTANA BY 09Z. ISOLATED SHOWERS
ALONG WITH THE POSSIBILITY OF A THUNDERSTORM CAN BE EXPECTED ALONG
THE FRONT. EXPECT SOUTHWEST TO WEST WIND GUSTS AROUND 50 MPH ALONG
THE FRONT AS WELL. THE PRECIPITATION WILL CHANGE TO ALL SNOW LATE
TONIGHT RESULTING IN LOWERING CEILINGS AND VISIBILITIES OF
MVFR/IFR BY 12Z WEDNESDAY MAINLY ALONG AND WEST OF A KSHR-KBIL
LINE. SURFACE WINDS WILL BECOME NORTHWEST 35-45 KTS BEHIND THE
FRONT. THE MOUNTAINS WILL BE OBSCURED THROUGHOUT THE NIGHT. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
WED THU FRI SAT SUN MON TUE
-----------------------------------------------------------
BIL 036/046 031/059 036/064 041/067 039/057 035/060 039/063
86/W 10/U 00/U 02/W 22/W 21/B 12/W
LVM 032/045 025/058 034/065 038/064 034/055 032/059 036/061
95/W 00/U 00/U 02/W 23/W 21/B 12/W
HDN 036/046 030/060 035/066 037/070 036/059 033/061 035/063
88/W 20/B 00/U 01/B 32/W 21/B 12/W
MLS 042/049 032/061 036/067 040/070 037/058 033/059 035/057
47/W 30/U 00/U 01/U 23/W 11/B 11/B
4BQ 039/044 032/055 032/065 037/070 036/057 032/058 034/059
38/W 51/B 00/U 01/U 33/W 11/B 11/B
BHK 041/051 033/059 033/065 036/069 035/056 031/056 032/053
26/W 41/B 00/U 01/U 33/W 11/B 11/B
SHR 035/038 029/054 031/061 035/067 034/054 031/057 034/060
79/J 51/B 00/U 01/B 43/W 22/W 22/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...RED FLAG WARNING IN EFFECT UNTIL 10 PM MDT THIS EVENING BELOW
6000 FEET FOR ZONES 28-34-39>41-56-63>68.
RED FLAG WARNING IN EFFECT UNTIL 10 PM MDT THIS EVENING FOR
ZONES 29>33-35>38-42-57-58.
WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO
MIDNIGHT MDT WEDNESDAY NIGHT FOR ZONE 38.
WINTER WEATHER ADVISORY IN EFFECT FROM 9 PM THIS EVENING TO 6
PM MDT WEDNESDAY FOR ZONES 40-56-64>66.
WY...RED FLAG WARNING IN EFFECT UNTIL 10 PM MDT THIS EVENING FOR
ZONES 98-99.
WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO
MIDNIGHT MDT WEDNESDAY NIGHT FOR ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1026 AM PDT TUE APR 14 2015
.SYNOPSIS...A COLD FRONT WILL PRESS SOUTH ACROSS THE AREA THROUGH
THIS EVENING RESULTING IN GUSTY WINDS AND AREAS OF BLOWING DUST.
GUSTY NORTH WINDS WILL PERSIST DOWN THE COLORADO RIVER MUCH OF THE
WEEK. COOLER TEMPERATURES ARE EXPECTED FOR THE MIDDLE OF THE WEEK
FOLLOWED BY A REBOUND TO ABOVE NORMAL TEMPERATURES OVER THE WEEKEND.
&&
.UPDATE...GREETINGS FROM AWIPS II AT NWS LAS VEGAS AS WE ARE NOW
BACK UP AND RUNNING ON OUR NEW COMPUTER SYSTEM. PLEASE BARE WITH US
OVER THE NEXT FEW DAYS AS WE CONTINUE TO ADJUST TO OUR NEW SYSTEM WE
USE TO COMPOSE FORECASTS AND WARNINGS AS THERE STILL MAY BE A FEW
GLITCHES WE WORK OUT.
NOW SHIFTING FROM ROBOT TO METEOROLOGY MODE, A SURFACE COLD FRONT
WAS LOCATED FROM NEAR SANDBURG TO INDEPENDENCE TO TONOPAH TO WESTERN
WHITE PINE COUNTY. SURFACE OBSERVATIONS HAVE SHOWN A NICE WIND SHIFT
WITH THE FRONT TO THE NORTH EXCEPT IN THE OWENS VALLEY WHERE MORE OF
A WESTERLY SHIFT WAS NOTED AND THE FRONT`S LOCATION IS MORE ILL-
DEFINED. BLOWING DUST WAS REPORTED AT BOTH TONOPAH AND ELY AND THE
TIKABOO PEAK WEBCAM ALSO SHOWED THIS. BLOWING DUST WILL CONTINUE
BEHIND THE FRONT FOR SEVERAL HOURS WITH A SLOW IMPROVEMENT IN
VISIBILITY ESPECIALLY IN ANY AREAS WHERE THICKER AMOUNTS OF DUST GET
LOFTED.
THE LATEST HRRR MODEL BRINGS THE FRONT INTO THE LAS VEGAS VALLEY
LATE THIS AFTERNOON INTO EARLY THIS EVENING AROUND RUSH HOUR WHICH
WILL MAKE FOR A STRONG HEADWIND ESPECIALLY ON HIGHWAY 95 INTO THE
NORTHWEST PART OF THE VALLEY AS THE WIND SHIFT NORTHWEST. THE FRONT
WILL PRESS SOUTH EARLY THIS EVENING WITH GUSTY NORTH WINDS LINGERING
ACROSS THE AREA INTO WEDNESDAY WHICH SUPPORT THE WIND ADVISORIES
STILL IN EFFECT.
OVERALL, THE CURRENT FORECAST WAS ADJUSTED TO BRING UP SKY COVER
OVER NORTHEAST CLARK AND NORTHERN MOHAVE COUNTY FOR THE BAND OF
ENHANCED CIRRUS THAT HAS DEVELOPED AND WAS MOVING EAST. ELSEWHERE,
THINGS LOOK OK AND NO OTHER CHANGES WERE MADE TO THE GRIDS.
&&
.AVIATION...FOR MCCARRAN...SOUTHWEST WINDS WILL CONTINUE AHEAD OF A
COLD FRONT THROUGH THIS AFTERNOON WITH SUSTAINED WINDS OF 20-30 KTS
GUSTS OF 35-40 KTS. THE FRONT IS EXPECTED TO CROSS THE LAS VEGAS
VALLEY BETWEEN 23Z TODAY AND 03Z WEDNESDAY SHIFTING WINDS TO THE
NORTHWEST. WINDS WILL REMAIN NORTHWEST THROUGH TONIGHT AND GRADUALLY
DECREASE TO 15-25 KTS. STRONG WINDS ALOFT WILL CREATE THE POTENTIAL
FOR MECHANICAL TURBULENCE. FEW-SCT CLOUDS AOA 20K FEET AT TIMES.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...A COLD FRONT WILL PRESS SOUTH ACROSS THE AREA THIS
AFTERNOON INTO THIS EVENING. WINDS WILL SHIFT FROM THE SOUTHWEST TO
THE NORTHWEST TO NORTH WITH THE FRONT WHICH SHOULD PASS THROUGH THE
LAS VEGAS VALLEY BETWEEN 23Z TODAY AND 03Z WEDNESDAY AND KEED
BETWEEN 03Z AND 05Z WEDNESDAY. GUSTS OF 30-40 KTS WITH LOCAL GUSTS
TO 50 KTS ARE EXPECTED JUST AHEAD OF AND BEHIND THE FRONT. BLDU IS
POSSIBLE ESPECIALLY DOWNWIND OF ANY DRY LAKE BEDS WITH VSBY REDUCED
TO MVFR OR LOWER. WINDS WILL GRADUALLY DECREASE OVERNIGHT TO 12-25
KTS. A FEW SHOWERS WILL BE POSSIBLE OVER CENTRAL NYE AND NORTHERN
LINCOLN COUNTIES THIS AFTERNOON INTO EARLY THIS EVENING WITH CIGS AS
LOW AS 6K-8K FEET NEAR ANY SHOWERS. &&
.FIRE WEATHER...DUE TO THE COMBINATION OF GUSTY WINDS AND LOW
RELATIVE HUMIDITY, RED FLAG WARNINGS ARE IN EFFECT FOR CALIFORNIA
ZONE 226 AND ARIZONA ZONE 102 AS FUELS OR ANTECEDENT CONDITIONS IN
THESE ZONES COULD CREATE THE POTENTIAL FOR RAPID WILDFIRE GROWTH.
ALTHOUGH ACROSS THE REMAINDER OF THE AREA GUSTY WINDS AND LOW
RELATIVE HUMIDITY WILL MEET CRITICAL CONDITIONS, FUELS ARE NOT YET
CONSIDERED READY SO NO HEADLINES ARE IN EFFECT.
&&
.PREVIOUS DISCUSSION...
ISSUED AT 305 AM PDT TUE APR 14 2015
ISSUED BY NATIONAL WEATHER SERVICE FLAGSTAFF AZ
.SHORT TERM...THROUGH WEDNESDAY AFTERNOON.
STRONG WINDS WILL PERSIST ALL NIGHT AND CONTINUE INTO WEDNESDAY FOR
LOCATIONS ALONG THE COLORADO RIVER.
.LONG TERM...THURSDAY THROUGH SUNDAY.
CLOSED UPPER LOW WILL CONTINUE TO SPIN OVER THE FOUR CORNERS
THURSDAY INTO FRIDAY WITH HIGH PRESSURE SLOWLY BUILDING IN FROM THE
WEST. THIS WILL LEAVE OUR REGION UNDER A PERSISTENT NORTHERLY FLOW
WITH GUSTY WINDS PERSISTING ESPECIALLY DOWN THE COLORADO RIVER. THE
WINDS WILL EASE A BIT OVER THE WEEKEND AS THE LOW DRIFTS EAST AND
HIGH PRESSURE TRIES TO BUILD BACK INTO THE AREA. THIS WILL RESULT IN
A WARMING TREND THROUGH THE WEEKEND WITH TEMPERATURES RETURNING TO
ABOVE NORMAL LEVELS.
MEANWHILE A WEAK LOW PRESSURE TROUGH MAY DEVELOP OVER NORTHERN
CALIFORNIA AND DRIFT SOUTHWARD WHICH COULD RESULT IN JUST ENOUGH
MOISTURE AND INSTABILITY TO SPARK OFF A FEW CUMULUS BUILD UPS AND
ISOLATED SHOWERS OR THUNDERSTORMS ACROSS THE SIERRA. I`VE ADDED A
SLIGHT CHANCE OF THUNDER TO THOSE AREAS SATURDAY THROUGH MONDAY.
OTHERWISE DRY CONDITIONS LOOK TO CONTINUE THROUGH EARLY NEXT WEEK.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS SHOULD REPORT ANY REPORTS
OF STRONG WINDS EITHER WITH RESPECT TO GUSTS OR DAMAGE AS WELL AS
BLOWING DUST ALONG WITH ANY ESTIMATES OF VISIBILITY THROUGH
WEDNESDAY.
&&
$$
UPDATE/AVIATION/FIRE WEATHER...STACHELSKI
PREVIOUS...OUTLER
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
141 PM EDT TUE APR 14 2015
.SYNOPSIS...
HIGH PRESSURE WILL PUSH DOWN FROM CANADA WITH FAIR WEATHER AND
SEASONAL TEMPERATURES FOR THIS AFTERNOON THROUGH THURSDAY. THE
NEXT CHANCE FOR RAIN SHOWERS WILL COME ON THURSDAY NIGHT AS A WARM
FRONT APPROACHES THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED AT 11 AM... HIGH CLOUDS ARE STREAMING NORTHEAST ACROSS PA
AND SOUTHERN NY LATE THIS MORNING NORTH OF A STALLED FRONTAL
BOUNDARY OVER THE MID-ATLANTIC. THESE CLOUDS WILL PERSIST ACROSS
MUCH OF THE AREA SOUTH OF THE THRUWAY TODAY AND WILL ACT TO KEEP
TEMPERATURES DOWN SLIGHTLY OVER THE PREVIOUS FORECAST. HAVE
LOWERED MAX TEMPS BY A FEW DEGREES ESPECIALLY IN PA WHERE CLOUDS
WILL BE THICKEST. HIGHS SHOULD STILL REACH NEAR TO JUST ABOVE 60
IN MOST OF NORTHEAST PA AND SOUTHERN NY... WITH MID 60S IN SUNNIER
AREAS UP NEAR THE THRUWAY. PREVIOUS DISCUSSION IS BELOW.
RADARS SHOW A BAND OF SHOWERS OF RAIN FROM ABOUT UTICA TO
BINGHAMTON AND TOWANDA AT THIS TIME AND WORKING EAST AS THE UPPER
LEVEL WAVE MOVES INTO THE EASTERN GREAT LAKES. THIS WAVE HAS
PROVIDED THE IMPETUS TO PUSH A COLD FRONT INTO NY AND PA. HI RES
MODELS CONTINUE TO INDICATE THAT THIS BAND OF SHRA WILL CONTINUE
EASTWARD AND CLEAR THE POCONOS TO WRN CATSKILLS BY AROUND 12Z AS
THE UPPER WAVE AND COLD FRONT MOVE THRU. THERE WAS NO LIGHTNING
DETECTED AND SHOWALTER INDICES WERE ABOVE 0C SO NO THUNDER
IN GRIDS. THE HRRR IS QUICKEST IN MOVING PRECIP THRU NE PA/SERN NY
WITH THE HI RES ARW AND NMM HOLDING THE PRECIP BACK A COUPLE
HOURS LONGER. THE RAP REFLECTIVITY FIELDS SHOW THAT THE PRECIP
CLEARS THESE AREAS BY 12-13Z. SO I HAVE HELD ON TO SLGHT CHC AT
12Z IN THESE AREAS. REST OF FORECAST AREA WILL BE FREE OF PRECIP
BTWN 6Z AND 12Z.
AFTER THE PRECIP PASSES BY CLOUDS WILL CLEAR FOR A TIME THIS
MORNING. BUT COLD ADVECTION AT 850 MB AND SFC DEWPOINTS STILL IN
UPPER 30S SHUD LEAD TO SCT STRATOCUMULUS FORMING FOR A TIME BEFORE
ENUF DIURNAL MIXING TAKES PLACE BY MIDDAY TO MIX OUT THESE
CLOUDS. MODEL SOUNDINGS SUGGEST THIS AS WELL. THEN BY AFTERNOON
CIRRUS IN ADVANCE OF THE UPPER LEVEL LOW OVER TEXAS WILL ADVECT
NORTHEAST INTO THE UPPER CONFLUENT ZONE ALOFT WHICH CUTS ACRS
CENTRAL NY BY 18Z-21Z. SO WE EXPECT A SHIELD OF CIRRUS FROM SRN
NY ACROSS PA THIS AFTERNOON WHICH WILL BE THICK ENUF TO SPOIL A
MOSTLY SUNNY FORECAST. THESE CLOUDS WILL PUSH SOUTHEAST OF NE
PA/SERN NY THIS EVENING AS ANOTHER NRN BRANCH UPPER LEVEL SHORT
WAVE PUSHES SOUTHEAST FROM ONTARIO. SO... WE HAVE VARYING AMNTS
OF CLOUD COVER IN THE GRIDS FOR TODAY. NO POPS WARRANTING PRECIP
EXCEPT 12Z-14Z IN OUR FAR SE AND THESE ARE IN THE SLGHT CHC CAT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
AFTER CIRRUS SHIELD PUSHES SOUTHEAST OF NE PA AND SERN NY THIS
EVENING AN UPPER LEVEL WAVE WILL PUSH SOUTHEAST INTO NRN NEW
ENGLAND LATER TONIGHT AND WEDNESDAY WITH NY AND PA BEING ON THE
SUBSDC SIDE OF THIS TROUGH WITH THE UPPER RDG AXIS OVER THE ERN
LAKES. THIS WILL SUPPORT HIGH PRESSURE TO BUILD SOUTHWARD FROM
CANADA WITH A DRIER AIR AND SEASONAL TEMPS FOR TONIGHT...WED AND
WED NGT.
BY THURSDAY THE SFC HIGH SHIFTS OFF THE NEW ENGLAND COAST AND A
SRLY FLOW OF AIR WILL DEVELOP OVER NY AND PA WITH MID TO HI CLOUDS
SPREADING FROM SW TO NE ACRS C NY AND NE PA. LOOKING AT THE
SYNOPTIC MODELS IT LOOKS LIKE ANY PRECIP WILL HOLD OFF UNTIL AFTER
00Z FRI SO THU LOOKS DRY AND MILDER WITH SRLY WINDS.
FOR THURSDAY NIGHT...THE GFS...EURO...CMC AND UKMET ALL SHOW
DECENT LOW-LEVEL THETA-E ADVECTION ARND 850 MB WHICH WILL ALLOW
FOR DESTABLIZATION AND SHRA ACVTY TO WORK INTO NY AND NRN PA FROM
W TO E OVRNGT. IT LOOKS LIKE WRN AND CNTRL NY GET INTO SOME SHRA
ACVTY BTWN 00Z AND 06Z AND NE PA AND SERN NY AFTER 6Z SO HAVE
WORKED POP TIMING TO REFLECT THIS. SHOWALTER INDICES SUGGEST THE
AMS WILL BE STABLE ENUF SO NO MENTION OF THUNDER AT THIS POINT.
QPF AMNTS APPEARS TO BE ON THE ORDER OF ABT .25 INCHES WHICH WILL
NOT CAUSE ANY HYDRO ISSUES. THE NAM IS THE ODD MODEL OUT WITH MUCH
DRIER LL AIR TO START AND NOT ENUF MOISTURE ADVTN TO LEAD TO MUCH
PRECIP. SO WENT WITH GFS/EURO/CMC AND UKMET IDEAS AND HAVE CHC
POPS SHRA THU NGT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
LONGWAVE RIDGING IS FORECAST TO BUILD ACROSS THE EASTERN U.S.
EARLY IN THE LONG TERM PERIOD BEFORE THE PATTERN BECOMES A BIT
TRICKIER LATE IN THE PERIOD AS MODEL SOLUTIONS DIVERGE
SIGNIFICANTLY INTO NEXT WEEKEND.
QUIET WEATHER EXPECTED THUR INTO FRIDAY WITH NEAR TO SLIGHTLY ABOVE
NORMAL TEMPS. THE CHANCE OF SHOWERS INCREASES SAT INTO MONDAY AS
SHORTWAVE ENERGY ROUND THE UPPER RIDGE NEXT WEEKEND. THE EXTENT OF
LOWER HEIGHTS...WHICH WOULD SUPPORT A WETTER SOLUTION...IS IN
QUESTION...WITH THE GFS SYSTEM KEEPING A STRONGER RIDGE. THE ECMWF
BRINGS AN UPPER LOW EASTWARD OUT OF THE PLAINS INTO THE REGION.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THURSDAY... WITH THE POSSIBLE
EXCEPTION OF SPOTTY LIGHT FOG IN THE RIVER VALLEYS WEDNESDAY
MORNING. WINDS WILL BE LIGHT AND VARIABLE TONIGHT... THEN
NORTHWEST AT 5 TO 15 KTS WEDNESDAY... BECOMING LIGHT AND VARIABLE
AGAIN WEDNESDAY NIGHT INTO THURSDAY.
.OUTLOOK...
WED/THUR...VFR.
THU NGT-SAT...POSSIBLE RESTRICTIONS IN -SHRA.
&&
.FIRE WEATHER...
DRIER AIR BEHIND A COLD FRONTAL PASSAGE WILL LEAD TO RELATIVE
HUMIDITIES FALLING BELOW 30 PERCENT THIS AFTERNOON. WINDS LOOK TO
BE LESS THAN 20 MPH ACROSS CENTRAL NEW YORK AND NORTHEAST
PENNSYLVANIA. IN ADDITION THE RAIN SHOWERS FROM LAST NIGHT AND
EARLY THIS MORNING SHOULD KEEP FINE FUELS ABOVE 10 PERCENT MOST OF
THE DAY. THEREFORE FIRE CONDITIONS ARE NOT EXPECTED TO APPROACH RED
FLAG CONDITIONS TODAY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MSE
NEAR TERM...DJN/MSE
SHORT TERM...DJN
LONG TERM...
AVIATION...DGM/MSE
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
138 PM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL EXIT NORTHEAST PENNSYLVANIA AND SOUTHEAST NEW
YORK EARLY THIS MORNING TAKING THE SHOWERS WITH IT. AFTER THIS
FRONT PASSES BY, HIGH PRESSURE WILL PUSH DOWN FROM CANADA WITH
FAIR WEATHER AND SEASONAL TEMPERATURES FOR THE REST OF TODAY
THROUGH THURSDAY. THE NEXT CHANCE FOR RAIN SHOWERS WILL COME ON
THURSDAY NIGHT AS A WARM FRONT APPROACHES THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED AT 11 AM... HIGH CLOUDS ARE STREAMING NORTHEAST ACROSS PA
AND SOUTHERN NY LATE THIS MORNING NORTH OF A STALLED FRONTAL
BOUNDARY OVER THE MID-ATLANTIC. THESE CLOUDS WILL PERSIST ACROSS
MUCH OF THE AREA SOUTH OF THE THRUWAY TODAY AND WILL ACT TO KEEP
TEMPERATURES DOWN SLIGHTLY OVER THE PREVIOUS FORECAST. HAVE
LOWERED MAX TEMPS BY A FEW DEGREES ESPECIALLY IN PA WHERE CLOUDS
WILL BE THICKEST. HIGHS SHOULD STILL REACH NEAR TO JUST ABOVE 60
IN MOST OF NORTHEAST PA AND SOUTHERN NY... WITH MID 60S IN SUNNIER
AREAS UP NEAR THE THRUWAY. PREVIOUS DISCUSSION IS BELOW.
RADARS SHOW A BAND OF SHOWERS OF RAIN FROM ABOUT UTICA TO
BINGHAMTON AND TOWANDA AT THIS TIME AND WORKING EAST AS THE UPPER
LEVEL WAVE MOVES INTO THE EASTERN GREAT LAKES. THIS WAVE HAS
PROVIDED THE IMPETUS TO PUSH A COLD FRONT INTO NY AND PA. HI RES
MODELS CONTINUE TO INDICATE THAT THIS BAND OF SHRA WILL CONTINUE
EASTWARD AND CLEAR THE POCONOS TO WRN CATSKILLS BY AROUND 12Z AS
THE UPPER WAVE AND COLD FRONT MOVE THRU. THERE WAS NO LIGHTNING
DETECTED AND SHOWALTER INDICES WERE ABOVE 0C SO NO THUNDER
IN GRIDS. THE HRRR IS QUICKEST IN MOVING PRECIP THRU NE PA/SERN NY
WITH THE HI RES ARW AND NMM HOLDING THE PRECIP BACK A COUPLE
HOURS LONGER. THE RAP REFLECTIVITY FIELDS SHOW THAT THE PRECIP
CLEARS THESE AREAS BY 12-13Z. SO I HAVE HELD ON TO SLGHT CHC AT
12Z IN THESE AREAS. REST OF FORECAST AREA WILL BE FREE OF PRECIP
BTWN 6Z AND 12Z.
AFTER THE PRECIP PASSES BY CLOUDS WILL CLEAR FOR A TIME THIS
MORNING. BUT COLD ADVECTION AT 850 MB AND SFC DEWPOINTS STILL IN
UPPER 30S SHUD LEAD TO SCT STRATOCUMULUS FORMING FOR A TIME BEFORE
ENUF DIURNAL MIXING TAKES PLACE BY MIDDAY TO MIX OUT THESE
CLOUDS. MODEL SOUNDINGS SUGGEST THIS AS WELL. THEN BY AFTERNOON
CIRRUS IN ADVANCE OF THE UPPER LEVEL LOW OVER TEXAS WILL ADVECT
NORTHEAST INTO THE UPPER CONFLUENT ZONE ALOFT WHICH CUTS ACRS
CENTRAL NY BY 18Z-21Z. SO WE EXPECT A SHIELD OF CIRRUS FROM SRN
NY ACROSS PA THIS AFTERNOON WHICH WILL BE THICK ENUF TO SPOIL A
MOSTLY SUNNY FORECAST. THESE CLOUDS WILL PUSH SOUTHEAST OF NE
PA/SERN NY THIS EVENING AS ANOTHER NRN BRANCH UPPER LEVEL SHORT
WAVE PUSHES SOUTHEAST FROM ONTARIO. SO... WE HAVE VARYING AMNTS
OF CLOUD COVER IN THE GRIDS FOR TODAY. NO POPS WARRANTING PRECIP
EXCEPT 12Z-14Z IN OUR FAR SE AND THESE ARE IN THE SLGHT CHC CAT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
AFTER CIRRUS SHIELD PUSHES SOUTHEAST OF NE PA AND SERN NY THIS
EVENING AN UPPER LEVEL WAVE WILL PUSH SOUTHEAST INTO NRN NEW
ENGLAND LATER TONIGHT AND WEDNESDAY WITH NY AND PA BEING ON THE
SUBSDC SIDE OF THIS TROUGH WITH THE UPPER RDG AXIS OVER THE ERN
LAKES. THIS WILL SUPPORT HIGH PRESSURE TO BUILD SOUTHWARD FROM
CANADA WITH A DRIER AIR AND SEASONAL TEMPS FOR TONIGHT...WED AND
WED NGT.
BY THURSDAY THE SFC HIGH SHIFTS OFF THE NEW ENGLAND COAST AND A
SRLY FLOW OF AIR WILL DEVELOP OVER NY AND PA WITH MID TO HI CLOUDS
SPREADING FROM SW TO NE ACRS C NY AND NE PA. LOOKING AT THE
SYNOPTIC MODELS IT LOOKS LIKE ANY PRECIP WILL HOLD OFF UNTIL AFTER
00Z FRI SO THU LOOKS DRY AND MILDER WITH SRLY WINDS.
FOR THURSDAY NIGHT...THE GFS...EURO...CMC AND UKMET ALL SHOW
DECENT LOW-LEVEL THETA-E ADVECTION ARND 850 MB WHICH WILL ALLOW
FOR DESTABLIZATION AND SHRA ACVTY TO WORK INTO NY AND NRN PA FROM
W TO E OVRNGT. IT LOOKS LIKE WRN AND CNTRL NY GET INTO SOME SHRA
ACVTY BTWN 00Z AND 06Z AND NE PA AND SERN NY AFTER 6Z SO HAVE
WORKED POP TIMING TO REFLECT THIS. SHOWALTER INDICES SUGGEST THE
AMS WILL BE STABLE ENUF SO NO MENTION OF THUNDER AT THIS POINT.
QPF AMNTS APPEARS TO BE ON THE ORDER OF ABT .25 INCHES WHICH WILL
NOT CAUSE ANY HYDRO ISSUES. THE NAM IS THE ODD MODEL OUT WITH MUCH
DRIER LL AIR TO START AND NOT ENUF MOISTURE ADVTN TO LEAD TO MUCH
PRECIP. SO WENT WITH GFS/EURO/CMC AND UKMET IDEAS AND HAVE CHC
POPS SHRA THU NGT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
LONGWAVE RIDGING IS FORECAST TO BUILD ACROSS THE EASTERN U.S.
EARLY IN THE LONG TERM PERIOD BEFORE THE PATTERN BECOMES A BIT
TRICKIER LATE IN THE PERIOD AS MODEL SOLUTIONS DIVERGE
SIGNIFICANTLY INTO NEXT WEEKEND.
QUIET WEATHER EXPECTED THUR INTO FRIDAY WITH NEAR TO SLIGHTLY ABOVE
NORMAL TEMPS. THE CHANCE OF SHOWERS INCREASES SAT INTO MONDAY AS
SHORTWAVE ENERGY ROUND THE UPPER RIDGE NEXT WEEKEND. THE EXTENT OF
LOWER HEIGHTS...WHICH WOULD SUPPORT A WETTER SOLUTION...IS IN
QUESTION...WITH THE GFS SYSTEM KEEPING A STRONGER RIDGE. THE ECMWF
BRINGS AN UPPER LOW EASTWARD OUT OF THE PLAINS INTO THE REGION.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THURSDAY... WITH THE POSSIBLE
EXCEPTION OF SPOTTY LIGHT FOG IN THE RIVER VALLEYS WEDNESDAY
MORNING. WINDS WILL BE LIGHT AND VARIABLE TONIGHT... THEN
NORTHWEST AT 5 TO 15 KTS WEDNESDAY... BECOMING LIGHT AND VARIABLE
AGAIN WEDNESDAY NIGHT INTO THURSDAY.
.OUTLOOK...
WED/THUR...VFR.
THU NGT-SAT...POSSIBLE RESTRICTIONS IN -SHRA.
&&
.FIRE WEATHER...
DRIER AIR BEHIND A COLD FRONTAL PASSAGE WILL LEAD TO RELATIVE
HUMIDITIES FALLING BELOW 30 PERCENT THIS AFTERNOON. WINDS LOOK TO
BE LESS THAN 20 MPH ACROSS CENTRAL NEW YORK AND NORTHEAST
PENNSYLVANIA. IN ADDITION THE RAIN SHOWERS FROM LAST NIGHT AND
EARLY THIS MORNING SHOULD KEEP FINE FUELS ABOVE 10 PERCENT MOST OF
THE DAY. THEREFORE FIRE CONDITIONS ARE NOT EXPECTED TO APPROACH RED
FLAG CONDITIONS TODAY.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN/MSE
SHORT TERM...DJN
LONG TERM...
AVIATION...DGM/MSE
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
320 PM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL SAG SOUTH AND MOVE ACROSS THE AREA LATE TONIGHT
AND WEDNESDAY MORNING. A WEDGE OF HIGH PRESSURE...PUSHING IN FROM
THE NORTH...WILL KEEP THE WEATHER UNSETTLED WEDNESDAY. LOW PRESSURE
IS EXPECTED TO MOVE UP THE SOUTHEAST COAST THURSDAY INTO FRIDAY...
KEEPING SHOWERS IN THE FORECAST. IT WILL BE WARM AND UNSETTLED
DURING THE WEEKEND AND INTO EARLY NEXT WEEK. A COLD FRONT MAY MOVE
ACROSS THE AREA ON TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM TUESDAY...ENTRENCHED IN WARM AND MOIST AIR MASS
AHEAD OF A COLD FRONT WHICH WILL DROP SOUTH THROUGH NORTH CAROLINA
THROUGH TONIGHT. DEWPOINTS IN THE MID 60S TO AROUND 70 THIS
AFTERNOON AND TEMPS BETWEEN 75 TO 80 MOST PLACES AWAY FROM THE
COAST. MAY SEE SOME SKIES BRIGHTEN THIS AFTERNOON WHICH COULD HELP
PROPEL TEMPS UP A LITTLE FURTHER. DEEP MOISTURE THROUGH THIS
AFTERNOON WITH PCP WATER VALUES UP CLOSE TO 2 INCHES AND SOUNDING
PARAMETERS ALL POINTING TO POTENTIAL FOR TSTMS. THE PRIMARY FOCUS
WOULD BE FURTHER NW INTO CENTRAL CAROLINAS AS WAVE OF LOW PRESSURE
MOVES UP THROUGH THE TENNESSEE VALLEY TOWARD THE NORTHEAST...BUT A
SHORTWAVE MOVING THROUGH WILL BE THE MAIN DRIVER TO ENHANCE ANY
CONVECTION OVER OUR LOCAL FORECAST AREA THROUGH EARLY THIS EVE.
HRRR AND NAM SHOWING CONVECTION PICKING UP BETWEEN 19Z AND 00Z
MOVING ACROSS FROM SOUTHWEST TO NORTHEAST. WINDS WILL BEGIN TO
VEER THROUGH THE LOW LEVELS AND MAY SEE GREATER WIND SHEAR WITH
ANY STORMS THAT DEVELOP THROUGH LATE THIS AFTERNOON. POTENTIAL
WILL EXIST ESPECIALLY THROUGH LATE THIS AFTN TO SEE SOME ISOLATED
STRONGER STORMS. SPC HAS NORTHWEST PORTIONS OF FORECAST AREA IN
MARGINAL RISK WITH STRONGER WIND THREAT...BUT MAIN THREAT AREA
SHOULD REMAIN FARTHER TO THE NORTH AND WEST.
ONCE THIS SHORTWAVE RIDES OFF TO THE NORTHEAST THIS
EVENING...SUBSIDENCE AND DRIER AIR WILL MAKE ITS WAY INTO THE AREA
ON THE BACK END. WINDS SHIFT TO A MORE WESTERLY DIRECTION THROUGH
THE LOW LEVELS AS COLD FRONT DROPS SOUTH AFTER MIDNIGHT. GFS
SHOWS A DROP IN PCP WATER DOWN TO 1.5 INCHES BY THIS EVENING. HRRR
SHOWS SHOWERS MOVING OFF TO THE NORTHEAST LEAVING ONLY ISOLATED
SHWRS OVER LOCAL AREA UNTIL COLD FRONT REACHES THE AREA LATER IN
THE NIGHT.
COLD FRONT WILL DROP SOUTH THROUGH TONIGHT WITH WINDS SHIFTING
AROUND FURTHER...BECOMING NORTH BEHIND FRONT. SHOULD SEE ANOTHER
POTENTIAL FOR INCREASED SHOWER ACTIVITY AS COLD FRONT MOVES
THROUGH AREA OVERNIGHT...ESPECIALLY BETWEEN 3 AM AND DAYBREAK.
COOLER AIR WILL MAKE ITS WAY IN BEHIND FRONT WHICH SHOULD BE
RUNNING WEST TO EAST ACROSS SOUTH CAROLINA BY MORNING. TEMPS
SHOULD DROP BELOW 60 BY DAYBREAK OVER MOST OF AREA.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...COMPLICATED FORECAST WITH MANY MOVING
PARTS AND GIVEN THE VARIOUS MODEL SOLUTIONS...IT DOES MAKE IT
DIFFICULT TO BE OVERLY CONFIDENT AS TO WHEN TO INCLUDE THE HIGHEST
POPS. HIGHLY CONFIDENT RAINFALL WILL OCCUR AT ALL LOCATIONS AT
SOME POINT DURING THIS PERIOD. A COLD FRONT WILL BE SAGGING
SOUTHWARD THROUGH THE FORECAST AREA WED MORNING WITH A SHORT-LIVED
WEDGE OF HIGH PRESSURE BUILDING SOUTHWARD INTO THE FORECAST WED
AFTERNOON AND NIGHT. WEAK ISENTROPIC UPGLIDE WILL DEVELOP IN THE
WAKE OF THE FRONT AND SO WILL KEEP A PESSIMISTIC FORECAST WITH
MAINLY CLOUDY SKIES AND LIKELY POPS.
SEVERAL WEAK SHORTWAVES WILL MOVE THROUGH THE FLOW...BUT AGAIN THE
TIMING AND POSITIONAL DISCREPANCIES PERSIST. FINALLY...LOW
PRESSURE IS EXPECTED TO DEVELOP TO OUR SOUTH AND MOVE SLOWLY UP
THE COAST...PERHAPS MAKING ITS CLOSEST APPROACH THU NIGHT AND
FRI. ASSOCIATED LIFT SHOULD BE HIGHEST ON THE COAST DURING THIS
TIME...BUT WITH DEEP MOISTURE RETURNING...WILL KEEP THE POPS HIGH
THROUGHOUT.
CLOUD COVER WILL SHRINK THE DIURNAL RANGE WITH HIGH TEMPS
REMAINING NEAR OR SLIGHTLY BELOW NORMAL AND LOW TEMPS REMAINING
ABOVE NORMAL.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...DEEP MID-LEVEL CLOSED LOW ACROSS TX/NM
WILL LIFT SLOWLY NE WHILE OPENING THROUGH THE PERIOD. GUIDANCE
DIFFERS SIGNIFICANTLY WITHIN THE MEDIUM RANGE IN THE EVOLUTION OF
THIS FEATURE...AS THE GFS DIGS IT QUITE DEEP TOWARDS THE GOM AND
BRINGS A POTENT VORT IMPULSE AND ASSOCIATED COLD FRONT ACROSS THE
CAROLINAS SUNDAY...WHILE THE ECMWF KEEP THE FEATURE DEFLECTED WELL
TO THE NORTH AND THUS CREATES NO NOTICEABLE AIR MASS CHANGE DURING
THE PERIOD. HESITATE TO MAKE ANY SIGNIFICANT CHANGES TO THE
EXTENDED WHICH WERE BASED PRIMARILY ON THE GFS...BUT WITH A STRONG
RIDGE IN PLACE ACROSS THE SOUTHEAST LATE IN THE WEEK...WILL BLEND
SOME SUPPORT TO THE ECM SOLUTION. THIS PRODUCES SEASONABLE TO
ABOVE SEASONABLE TEMPERATURES THROUGH THE EXTENDED...ALONG WITH A
CHANCE FOR RAINFALL EACH DAY AS A REMNANT FRONT WAVERS IN THE
VICINITY ACTING AS A FOCUS FOR SHOWERS WITHIN DEEP SW FLOW. BEST
CHANCE FOR RAINFALL WILL BE THE FIRST HALF OF THE PERIOD
HOWEVER...THANKS TO A WEAK WAVE OF LOW PRESSURE OFFSHORE FRIDAY
WITH A RENEWED PUSH OF THE STALLED BOUNDARY BEHIND IT. A DRYING
TREND LOOKS TO DEVELOP EARLY NEXT WEEK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...STILL NOT VERY CONFIDENT ABOUT CONVECTION THIS
AFTERNOON. WILL LEAN ON THE HRRR MODEL THAT SHOWS A PRETTY DECENT
BAND OF CONVECTION SETTING UP BETWEEN FLO AND THE MYRTLES BY 20Z.
THIS ACTIVITY IS COURTESY OF LOW PRESSURE CENTERED WEST OF THE
REGION WITH SPOKES OF VORTICITY ROTATING EAST OF THE LOW. THE LAST
VORT WILL MOVE NORTHEAST AND OUT OF THE REGION LATE THIS
AFTERNOON...FOLLOWED BY CLEARING SKIES.
TONIGHT...STRATUS WILL AGAIN SET UP...WITH WINDS SHIFTING TO THE
NORTH LATE IN THE FORECAST PERIOD AS A BACK DOOR FRONT DROPS IN.
THERE WILL LIKELY BE SOME PRECIP ALONG AND BEHIND THE
FRONT...PROBABLY MORE DRIZZLE THAN RAIN.
EXTENDED OUTLOOK...PREDOMINATELY IFR CONDITIONS ARE EXPECTED WED
AFTERNOON THROUGH THURSDAY WITH A WEDGE. IMPROVING CONDITIONS FRI.
DETERIORATING CONDITIONS AGAIN SATURDAY AFTERNOON THROUGH SUNDAY
WITH A COLD FRONT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM TUESDAY...SOUTH TO SW WINDS WILL CONTINUE THROUGH
MOST OF TONIGHT IN ADVANCE OF COLD FRONT DROPPING DOWN FROM THE
NORTH. AS THE FRONT DRAWS CLOSER...THE WINDS WILL PICK UP SLIGHTLY
AS THEY VEER FURTHER TO THE SOUTHWEST AND EVENTUALLY AROUND TO THE
NORTH BEHIND THE FRONT. LOOKS LIKE THE COLD FRONT WILL RUN WEST TO
EAST ACROSS SOUTH CAROLINA BISECTING LOCAL WATERS BY DAYBREAK.
WINDS WILL CONTINUE IN THE GENERAL 10 TO 15 KT RANGE...WITH SEAS
RANGING FROM 2 TO 4 FT MOST PLACES WITH A SLIGHT RISE OVERNIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...A NE SURGE WILL GET UNDERWAY IN THE WAKE OF
A SOUTHWARD SAGGING COLD FRONT WEDNESDAY MORNING. HIGH PRESSURE
WILL BUILD SOUTHWARD LATE WED NIGHT INTO THU. AS LOW PRESSURE
DEVELOPS TO OUR SOUTH AND MOVES UP THE COAST...THE PRESSURE
GRADIENT WILL TIGHTEN...ESPECIALLY WED NIGHT INTO THU AND THIS IS
WHEN I WILL FORECAST THE STRONGEST WINDS AND HIGHEST SEAS...UP TO
20 TO 25 KT AND 5 TO 8 FT SEAS. I EXPECT A PERIOD OF SMALL CRAFT
ADVISORY CONDITIONS WILL DEVELOP BY WED EVE AND THEN PERSIST INTO
THU WITH SEAS PERHAPS NOT SUBSIDING BELOW ADVISORY CRITERIA UNTIL
THU NIGHT...PERHAPS NOT UNTIL FRI MORNING ACROSS THE NORTHERN
WATERS.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...WEAK LOW PRESSURE WILL BE NEARLY DIRECTLY
OVERHEAD FRIDAY MORNING...WITH MOST OF THE STRONG WINDS/TIGHT
GRADIENT NORTH OF THE REGION TO START THE PERIOD. WINDS TURN TO AN
OFFSHORE COMPONENT MUCH OF FRIDAY INTO SATURDAY BEHIND THIS LOW
PRESSURE...BEFORE BERMUDA TYPE RIDGE BECOMES THE DOMINANT FEATURE
ONCE AGAIN WITH SW FLOW PERSISTING THROUGH SATURDAY...BEFORE
QUICKLY BECOMING NE AS A COLD FRONT DROPS BACK ACROSS THE WATERS
SUNDAY. SPEEDS WILL BE AROUND 10 KTS OR LESS REGARDLESS OF
DIRECTION. WAVE HEIGHTS WILL BE HIGHEST FRIDAY MORNING AS RESIDUAL
WIND WAVE/SWELL FROM FRIDAY SLOWLY FALLS ACROSS THE WATERS...AND
3-5 FT SEAS WILL BE COMMON THE FIRST HALF OF FRIDAY. SEAS WILL
THEN FALL TO 2-4 FT SATURDAY AND SUNDAY...ALTHOUGH THE PRIMARY
WAVE WILL FOLLOW THE WINDS THROUGH THE WKND.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...RJD
LONG TERM...JDW
AVIATION...RGZ/DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
214 PM EDT TUE APR 14 2015
.SYNOPSIS...
UNSETTLED CONDITIONS WILL PERSIST TODAY AS A SERIES OF WEAK
DISTURBANCES MOVE ACROSS. A COLD FRONT WILL CROSS THE AREA EARLY
WEDNESDAY MORNING...STALLING TO OUR SOUTH ON THURSDAY. LOW
PRESSURE MAY DEVELOP ALONG THE FRONT THURSDAY INTO FRIDAY..LIFTING
NORTH OF THE AREA SATURDAY. A COLD FRONT WILL MOVE ACROSS THE
CAROLINAS FROM THE WEST LATE SATURDAY. HIGH PRESSURE WILL BUILD IN
FROM THE WEST SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM TUESDAY...ENTRENCHED IN WARM AND MOIST AIR MASS
AHEAD OF A COLD FRONT WHICH WILL DROP SOUTH THROUGH NORTH CAROLINA
THROUGH TONIGHT. DEWPOINTS IN THE MID 60S TO AROUND 70 THIS
AFTERNOON AND TEMPS BETWEEN 75 TO 80 MOST PLACES AWAY FROM THE
COAST. MAY SEE SOME SKIES BRIGHTEN THIS AFTERNOON WHICH COULD HELP
PROPEL TEMPS UP A LITTLE FURTHER. DEEP MOISTURE THROUGH THIS
AFTERNOON WITH PCP WATER VALUES UP CLOSE TO 2 INCHES AND SOUNDING
PARAMETERS ALL POINTING TO POTENTIAL FOR TSTMS. THE PRIMARY FOCUS
WOULD BE FURTHER NW INTO CENTRAL CAROLINAS AS WAVE OF LOW PRESSURE
MOVES UP THROUGH THE TENNESSEE VALLEY TOWARD THE NORTHEAST...BUT A
SHORTWAVE MOVING THROUGH WILL BE THE MAIN DRIVER TO ENHANCE ANY
CONVECTION OVER OUR LOCAL FORECAST AREA THROUGH EARLY THIS EVE.
HRRR AND NAM SHOWING CONVECTION PICKING UP BETWEEN 19Z AND 00Z
MOVING ACROSS FROM SOUTHWEST TO NORTHEAST. WINDS WILL BEGIN TO
VEER THROUGH THE LOW LEVELS AND MAY SEE GREATER WIND SHEAR WITH
ANY STORMS THAT DEVELOP THROUGH LATE THIS AFTERNOON. POTENTIAL
WILL EXIST ESPECIALLY THROUGH LATE THIS AFTN TO SEE SOME ISOLATED
STRONGER STORMS. SPC HAS NORTHWEST PORTIONS OF FORECAST AREA IN
MARGINAL RISK WITH STRONGER WIND THREAT...BUT MAIN THREAT AREA
SHOULD REMAIN FARTHER TO THE NORTH AND WEST.
ONCE THIS SHORTWAVE RIDES OFF TO THE NORTHEAST THIS
EVENING...SUBSIDENCE AND DRIER AIR WILL MAKE ITS WAY INTO THE AREA
ON THE BACK END. WINDS SHIFT TO A MORE WESTERLY DIRECTION THROUGH
THE LOW LEVELS AS COLD FRONT DROPS SOUTH AFTER MIDNIGHT. GFS
SHOWS A DROP IN PCP WATER DOWN TO 1.5 INCHES BY THIS EVENING. HRRR
SHOWS SHOWERS MOVING OFF TO THE NORTHEAST LEAVING ONLY ISOLATED
SHWRS OVER LOCAL AREA UNTIL COLD FRONT REACHES THE AREA LATER IN
THE NIGHT.
COLD FRONT WILL DROP SOUTH THROUGH TONIGHT WITH WINDS SHIFTING
AROUND FURTHER...BECOMING NORTH BEHIND FRONT. SHOULD SEE ANOTHER
POTENTIAL FOR INCREASED SHOWER ACTIVITY AS COLD FRONT MOVES
THROUGH AREA OVERNIGHT...ESPECIALLY BETWEEN 3 AM AND DAYBREAK.
COOLER AIR WILL MAKE ITS WAY IN BEHIND FRONT WHICH SHOULD BE RUNNING
WEST TO EAST ACROSS SOUTH CAROLINA BY MORNING. DEWPOINT TEMPS SHOULD
DROP BELOW 60 BY DAYBREAK OVER MOST OF AREA WHILE TEMPS WILL BE
MAKING THERE WAY DOWN THROUGH THE 60S.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM TUESDAY...FORECAST REMAINS ONE OF LOWER CONFIDENCE AS A
MOISTURE LADEN SOUTHWEST FLOW CONTINUES AT THE MID LEVELS THROUGH
THE PERIOD. AT THE SURFACE A BACKDOOR FRONT WILL PUSH ACROSS THE
AREA DURING THE MORNING HOURS WEDNESDAY. SEVERAL WEAK SHORTWAVES
WILL MOVE THROUGH THE FLOW AND MODELS HAVE BEEN HAVING DIFFICULTY
WITH THE TIMING AND PLACEMENT OF THESE FEATURES. IT SEEMS TO
CHANGE DRAMATICALLY FROM CYCLE TO CYCLE. PRUDENCE CALLS FOR
KEEPING POPS IN THE FORECAST THROUGHOUT WITH AT LEAST SOME
VARIATION IN VALUES. THE LATEST BEST FORCING APPEARS TO OCCUR
THURSDAY AND I HAVE ELEVATED TO LIKELY IN SOME AREAS WITH HIGH
CHANCE ELSEWHERE. AIRMASS IN THE WAKE OF THE FRONT IS COOLER AND
HIGHS WILL BE CONFINED TO THE 60S BOTH DAYS AND OVERNIGHT LOWS IN
THE 50S SHOWING LITTLE DIURNAL RANGE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 330 AM TUESDAY...500MB PATTERN WILL FEATURE THE CLOSED LOW
ACROSS THE SOUTHWEST FINALLY GETTING KICKED OUT AND WEAKENING AS
IT MOVES TO THE EAST. IN FACT THE TROUGH WEAKENS SO MUCH A
SOUTHWEST FLOW WILL CONTINUE UNABATED THROUGH THE PERIOD. THIS
ALLOWS A BAROCLINIC ZONE TO REMAIN DRAPED ACROSS THE SOUTHEAST.
THIS SCENARIO IS BASED PRIMARILY ON THE GFS SOLUTIONS. THE ECMWF
PAINTS A DIFFERENT SCENARIO WITH THE LOW HOLDING BACK WITH THE
PERSISTENT WET SOUTHWEST PERSISTING. FOR THIS REASON I AM HOLDING
ON TO SLIGHT CHANCE POPS FOR SUNDAY WITH CHANCE EITHER SIDE OF
THIS. HIGHS WILL GENERALLY BE 75-80 DEGREES WITH LOWS IN THE LOWER
TO MIDDLE 60S.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...STILL NOT VERY CONFIDENT ABOUT CONVECTION THIS
AFTERNOON. WILL LEAN ON THE HRRR MODEL THAT SHOWS A PRETTY DECENT
BAND OF CONVECTION SETTING UP BETWEEN FLO AND THE MYRTLES BY 20Z.
THIS ACTIVITY IS COURTESY OF LOW PRESSURE CENTERED WEST OF THE
REGION WITH SPOKES OF VORTICITY ROTATING EAST OF THE LOW. THE LAST
VORT WILL MOVE NORTHEAST AND OUT OF THE REGION LATE THIS
AFTERNOON...FOLLOWED BY CLEARING SKIES.
TONIGHT...STRATUS WILL AGAIN SET UP...WITH WINDS SHIFTING TO THE
NORTH LATE IN THE FORECAST PERIOD AS A BACK DOOR FRONT DROPS IN.
THERE WILL LIKELY BE SOME PRECIP ALONG AND BEHIND THE
FRONT...PROBABLY MORE DRIZZLE THAN RAIN.
EXTENDED OUTLOOK...PREDOMINATELY IFR CONDITIONS ARE EXPECTED WED
AFTERNOON THROUGH THURSDAY WITH A WEDGE. IMPROVING CONDITIONS FRI.
DETERIORATING CONDITIONS AGAIN SATURDAY AFTERNOON THROUGH SUNDAY
WITH A COLD FRONT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 200 AM TUESDAY...SOUTH TO SW WINDS WILL CONTINUE THROUGH
MOST OF TONIGHT IN ADVANCE OF COLD FRONT DROPPING DOWN FROM THE
NORTH. AS THE FRONT DRAWS CLOSER...THE WINDS WILL PICK UP
SLIGHTLY AS THEY VEER FURTHER TO THE SOUTHWEST AND EVENTUALLY
AROUND TO THE NORTH BEHIND THE FRONT. LOOKS LIKE THE COLD FRONT
WILL RUN WEST TO EAST ACROSS SOUTH CAROLINA BISECTING LOCAL WATERS
BY DAYBREAK. WINDS WILL CONTINUE IN THE GENERAL 10 TO 15 KT
RANGE...WITH SEAS RANGING FROM 2 TO 4 FT MOST PLACES WITH A SLIGHT
RISE OVERNIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM TUESDAY...A NORTHEAST FLOW WILL BE IN THE INITIAL
STAGES EARLY WEDNESDAY AS A WEDGE PATTERN DEVELOPS. SPEEDS INCREASE
FROM AROUND TEN KNOTS EARLY TO A RANGE OF 20-15 KNOTS BY LATE IN THE
EVENING. THEY REMAIN IN THIS RANGE UNTIL LATER THURSDAY AFTERNOON
WHEN THEY BEGIN THEIR STEADY DECLINE TO TEN KNOTS OR LESS BY FRIDAY
MORNING. WITH THE STRONGER WINDS...SEAS WILL WORK UP TO SMALL CRAFT
CRITERIA BY WEDNESDAY EVENING AND REMAIN SO UNTIL LATE THURSDAY
AFTERNOON.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 330 AM TUESDAY...A RELATIVELY LIGHT FLOW IS EXPECTED FROM THE
EAST/SOUTHEAST FRIDAY ON THE ORDER OF 10-15 KNOTS. THE FLOW WILL
VEER TO SOUTHWEST SATURDAY AND PICK UP STEAM A BIT AS A COLD FRONT
MOVES CLOSER FROM THE WEST. NOT A LOT OF CONFIDENCE IN THIS FORECAST
HOWEVER AS MODELS HAVE BEEN STRUGGLING WITH THE FEATURES. SEAS WILL
BE 1-3 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RGZ
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
552 PM EDT TUE APR 14 2015
.SYNOPSIS...
HIGH PRESSURE TRACKS NORTH OF THE AREA LATE TONIGHT INTO WEDNESDAY.
LOW PRESSURE TRACKS SOUTH OF THE AREA THURSDAY...AND ANOTHER ON
SATURDAY. A COLD FRONT MAY ARRIVE SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
6 PM UPDATE...REMOVED THUNDER FROM SOUTHERN ZONES. ALSO...UPDATED
THE DEW POINTS...AS MUCH DRIER AIR IS MOVING INTO NORTHERN ZONES
QUICKER THAN FORECAST. OTHERWISE...NO CHANGES WERE NECESSARY.
PREVIOUS DISCUSSION FOLLOWS...
LOOKING AT A DECREASE IN COVERAGE OF THE SHOWERS THROUGH THE
REMAINDER OF THIS AFTERNOON AND EVENING AS THE SURFACE LOW FINALLY
PASSES TO THROUGH THE SOUTHERN ZONES AND TOWARDS THE MID ATLANTIC
COAST. AS WE DRY OUT FROM THE RAINFALL LAST NIGHT AND TODAY...WE
WILL NOT BE ABLE TO USHER IN A DRY AIRMASS FOR THE ENTIRETY OF
THE CWA...WITH LOW LEVEL MOISTURE LINGERING IN THE COAL FIELDS
AND SOUTHERN MOUNTAINS. HIGH PRESSURE WILL BUILD IN FOR THE
NORTHERN ZONES...BUT AN INVERTED SURFACE TROUGH WILL ASSIST WITH
THE LOW LEVEL MOISTURE RETENTION. WILL ALSO KEEP LOW END POPS IN
THESE AREAS AS WELL. NO THUNDER EXPECTED THROUGH THE FORECAST.
FOLLOWED THE HRRR FOR THE DEVELOPMENT OF THE POPS THROUGH 00Z
WEDNESDAY. NORTHWESTERN ZONES WILL SEE SOME CLEARING TONIGHT.
IN THE UPPER LEVELS...GETTING A BRIEF REPRIEVE WITH MODEST RIDGING
TONIGHT INTO WEDNESDAY BEFORE THE NEXT ROUND OF EMBEDDED VORTICITY
MAXIMA IN THE 500MB FLOW ARRIVES IN THE TUG FORK VALLEY.
NORTHERN HALF OF THE CWA WILL LIKELY BE WARMER THAN THE SOUTHERN
HALF GIVEN THE CLEARER CONDITIONS ON WEDNESDAY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
MODELS HAVE A MEAN UPPER TROUGH CONTINUING OVER THE WEST CENTRAL
PORTION OF THE NATION...WITH RATHER WEAK SOUTHWEST FLOW ALOFT
EXTENDING ACROSS THE OHIO AND TENNESSEE VALLEYS. THERE WILL BE WEAK
UPPER IMPULSES IN THIS SOUTHWEST FLOW ALOFT...BUT IT APPEARS MOST
MODELS FOCUS ON ONE THAT COMES ACROSS THURSDAY INTO THURSDAY NIGHT.
ALTHOUGH HIGH PRESSURE CENTERED OVER THE MID ATLANTIC STATES WILL BE
THE DOMINANT FEATURE AT THE SURFACE...THIS UPPER FEATURE APPEARS TO
HAVE ENOUGH DYNAMICS AND MOISTURE TO SQUEEZE OUT A HIGH POP AND LOW
QPF FORECAST THURSDAY AND EARLY THURSDAY NIGHT. OTHERWISE...HAVE TO
KEEP AT LEAST SLIGHT POPS IN MOST OF THE PERIOD...GIVEN THE
UNCERTAINTY OF OTHER IMPULSES ALOFT. THERE WILL BE LOTS OF CLOUDS
OUTSIDE OF ANY SHOWERS...ESPECIALLY THURSDAY...BUT LITTLE THUNDER
WITH MARGINAL MODEL INSTABILITY AT BEST. TEMPERATURES WILL BE
MODERATE WITH HIGHS THURSDAY IN THE MID 60S UNDER CLOUDS AND
SHOWERS...AND IN THE LOWER 70S FRIDAY WITH LESS SHOWERS AND PERHAPS
SOME SUNSHINE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
SRN STREAM DOMINATES THE CWA EARLY ON...WITH A WEAK WAVE MOVING
THROUGH LATE FRI NT INTO SAT. A NRN STREAM S/W TROUGH MAY STILL DIG
FAR ENOUGH S TO DRIVE A COLD FRONT AT LEAST INTO THE AREA LATE SAT.
THIS MAY BRING A BRIEF INTERLUDE OF DRY TO ONLY SCHC POPS AT LEAST
ACROSS THE N SAT NT INTO SUN.
SRN STREAM UPPER LOW LIFTS OUT OF THE DEEP S LATER SUN INTO MON AND
CROSSES THE CWA WITH ANOTHER ROUND OF PRECIPITATION. NRN STREAM
TROUGH AMPLIFICATION OVER THE CENTRAL AND ERN CONUS BEGINS EARLY
NEXT WEEK. MODELS ACTUALLY SHOW PHASING WITH THE SRN STREAM UPPER
LEVEL LOW ONCE THAT FEATURE IS PASSED THE AREA. THIS LEADS TO A
MILLER B TYPE SFC EVOLUTION WHICH BRINGS THE COLD FRONT ASSOCIATED
WITH THE FADING PRIMARY LOW THROUGH THE AREA SUN NT INTO MON. THIS
WOULD BE FOLLOWED BY DRYING DAY 7 NT.
TEMPERATURES A BIT HIGHER EARLY ON BUT OTHERWISE CLOSE TO PREVIOUS
WITH NO MAJOR DEVIATIONS FROM WPC INCLUDING THE NEW DAY 7.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
EXPECTING A SLOW DECREASE/SCATTERING OF THE SHOWERS ACROSS THE
AREA THROUGH THE EVENING AND INTO TONIGHT. SOUTHERN AND MOUNTAIN
TERMINALS WILL REMAIN SOCKED INTO THE LOWER MVFR CEILINGS/IFR
CEILINGS AT BKW WITHOUT ANY APPRECIABLE CHANGE OF AIRMASS IN THESE
LOCATIONS. SHOWERS WILL BE POSSIBLE THROUGH THE DURATION IN THE
SOUTHERN TERMINALS...BUT NOT HIGH ENOUGH CHANCE TO REQUIRE WEATHER
IN THE PREVAILING CONDITIONS. NORTHEASTERLY WINDS WILL ALSO BE A
PLAYER IN THE LOW CEILINGS IN THIS FORECAST.
EXPECT THE VISIBILITIES TO COME BACK TO VFR ONCE THE SHOWERS
END WITH WINDS IN THE 5-10KT RANGE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING OF SHOWERS ENDING MAY VARY. CEILINGS
COULD LIFT SOONER THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03
CRW CONSISTENCY H H H H L H H L L L L H
HTS CONSISTENCY H M M M M M M M M M M M
BKW CONSISTENCY H H H H H H M M M M M M
EKN CONSISTENCY M M M M M M H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY M M M M M M H H H H H H
AFTER 00Z THURSDAY...
IFR CONDITIONS POSSIBLE IN SHOWERS AND POSSIBLE THUNDERSTORMS AT
VARIOUS TIMES THRU THE WEEK.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR WVZ005-013-015-016-
018-024>030-033>040-046-047.
OH...NONE.
KY...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR KYZ105.
VA...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR VAZ003-004.
&&
$$
SYNOPSIS...TRM/JMV/26
NEAR TERM...SL/26
SHORT TERM...JMV
LONG TERM...TRM
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
347 PM EDT TUE APR 14 2015
.SYNOPSIS...
HIGH PRESSURE TRACKS NORTH OF THE AREA LATE TONIGHT INTO WEDNESDAY.
LOW PRESSURE TRACKS SOUTH OF THE AREA THURSDAY...AND ANOTHER ON
SATURDAY. A COLD FRONT MAY ARRIVE SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
LOOKING AT A DECREASE IN COVERAGE OF THE SHOWERS THROUGH THE
REMAINDER OF THIS AFTERNOON AND EVENING AS THE SURFACE LOW FINALLY
PASSES TO THROUGH THE SOUTHERN ZONES AND TOWARDS THE MID ATLANTIC
COAST. AS WE DRY OUT FROM THE RAINFALL LAST NIGHT AND TODAY...WE
WILL NOT BE ABLE TO USHER IN A DRY AIRMASS FOR THE ENTIRETY OF
THE CWA...WITH LOW LEVEL MOISTURE LINGERING IN THE COAL FIELDS
AND SOUTHERN MOUNTAINS. HIGH PRESSURE WILL BUILD IN FOR THE
NORTHERN ZONES...BUT AN INVERTED SURFACE TROUGH WILL ASSIST WITH
THE LOW LEVEL MOISTURE RETENTION. WILL ALSO KEEP LOW END POPS IN
THESE AREAS AS WELL. NO THUNDER EXPECTED THROUGH THE FORECAST.
FOLLOWED THE HRRR FOR THE DEVELOPMENT OF THE POPS THROUGH 00Z
WEDNESDAY. NORTHWESTERN ZONES WILL SEE SOME CLEARING TONIGHT.
IN THE UPPER LEVELS...GETTING A BRIEF REPRIEVE WITH MODEST RIDGING
TONIGHT INTO WEDNESDAY BEFORE THE NEXT ROUND OF EMBEDDED VORTICITY
MAXIMA IN THE 500MB FLOW ARRIVES IN THE TUG FORK VALLEY.
NORTHERN HALF OF THE CWA WILL LIKELY BE WARMER THAN THE SOUTHERN
HALF GIVEN THE CLEARER CONDITIONS ON WEDNESDAY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
MODELS HAVE A MEAN UPPER TROUGH CONTINUING OVER THE WEST CENTRAL
PORTION OF THE NATION...WITH RATHER WEAK SOUTHWEST FLOW ALOFT
EXTENDING ACROSS THE OHIO AND TENNESSEE VALLEYS. THERE WILL BE WEAK
UPPER IMPULSES IN THIS SOUTHWEST FLOW ALOFT...BUT IT APPEARS MOST
MODELS FOCUS ON ONE THAT COMES ACROSS THURSDAY INTO THURSDAY NIGHT.
ALTHOUGH HIGH PRESSURE CENTERED OVER THE MID ATLANTIC STATES WILL BE
THE DOMINANT FEATURE AT THE SURFACE...THIS UPPER FEATURE APPEARS TO
HAVE ENOUGH DYNAMICS AND MOISTURE TO SQUEEZE OUT A HIGH POP AND LOW
QPF FORECAST THURSDAY AND EARLY THURSDAY NIGHT. OTHERWISE...HAVE TO
KEEP AT LEAST SLIGHT POPS IN MOST OF THE PERIOD...GIVEN THE
UNCERTAINTY OF OTHER IMPULSES ALOFT. THERE WILL BE LOTS OF CLOUDS
OUTSIDE OF ANY SHOWERS...ESPECIALLY THURSDAY...BUT LITTLE THUNDER
WITH MARGINAL MODEL INSTABILITY AT BEST. TEMPERATURES WILL BE
MODERATE WITH HIGHS THURSDAY IN THE MID 60S UNDER CLOUDS AND
SHOWERS...AND IN THE LOWER 70S FRIDAY WITH LESS SHOWERS AND PERHAPS
SOME SUNSHINE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
SRN STREAM DOMINATES THE CWA EARLY ON...WITH A WEAK WAVE MOVING
THROUGH LATE FRI NT INTO SAT. A NRN STREAM S/W TROUGH MAY STILL DIG
FAR ENOUGH S TO DRIVE A COLD FRONT AT LEAST INTO THE AREA LATE SAT.
THIS MAY BRING A BRIEF INTERLUDE OF DRY TO ONLY SCHC POPS AT LEAST
ACROSS THE N SAT NT INTO SUN.
SRN STREAM UPPER LOW LIFTS OUT OF THE DEEP S LATER SUN INTO MON AND
CROSSES THE CWA WITH ANOTHER ROUND OF PRECIPITATION. NRN STREAM
TROUGH AMPLIFICATION OVER THE CENTRAL AND ERN CONUS BEGINS EARLY
NEXT WEEK. MODELS ACTUALLY SHOW PHASING WITH THE SRN STREAM UPPER
LEVEL LOW ONCE THAT FEATURE IS PASSED THE AREA. THIS LEADS TO A
MILLER B TYPE SFC EVOLUTION WHICH BRINGS THE COLD FRONT ASSOCIATED
WITH THE FADING PRIMARY LOW THROUGH THE AREA SUN NT INTO MON. THIS
WOULD BE FOLLOWED BY DRYING DAY 7 NT.
TEMPERATURES A BIT HIGHER EARLY ON BUT OTHERWISE CLOSE TO PREVIOUS
WITH NO MAJOR DEVIATIONS FROM WPC INCLUDING THE NEW DAY 7.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
EXPECTING A SLOW DECREASE/SCATTERING OF THE SHOWERS ACROSS THE
AREA THROUGH THE EVENING AND INTO TONIGHT. SOUTHERN AND MOUNTAIN
TERMINALS WILL REMAIN SOCKED INTO THE LOWER MVFR CEILINGS/IFR
CEILINGS AT BKW WITHOUT ANY APPRECIABLE CHANGE OF AIRMASS IN THESE
LOCATIONS. SHOWERS WILL BE POSSIBLE THROUGH THE DURATION IN THE
SOUTHERN TERMINALS...BUT NOT HIGH ENOUGH CHANCE TO REQUIRE WEATHER
IN THE PREVAILING CONDITIONS. NORTHEASTERLY WINDS WILL ALSO BE A
PLAYER IN THE LOW CEILINGS IN THIS FORECAST.
EXPECT THE VISIBILITIES TO COME BACK TO VFR ONCE THE SHOWERS
END WITH WINDS IN THE 5-10KT RANGE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING OF SHOWERS ENDING MAY VARY. CEILINGS
COULD LIFT SOONER THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H L H H L L L
HTS CONSISTENCY H H H H H H M M M M M M
BKW CONSISTENCY H H H H H H H H M M M M
EKN CONSISTENCY M M M M M M M M H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY M M M M M M M M H H H H
AFTER 18Z WEDNESDAY...
IFR CONDITIONS POSSIBLE IN SHOWERS AND POSSIBLE THUNDERSTORMS AT
VARIOUS TIMES THRU THE WEEK.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR WVZ005-013-015-016-
018-024>030-033>040-046-047.
OH...NONE.
KY...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR KYZ105.
VA...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR VAZ003-004.
&&
$$
SYNOPSIS...TRM/JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...TRM
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
248 PM EDT TUE APR 14 2015
.SYNOPSIS...
LOW PRESSURE PASSES TO THE SOUTH. HIGH PRESSURE TRACKS NORTH OF
THE AREA LATE TONIGHT AND INTO WEDNESDAY. WEAK DISTURBANCES KEEP
THE WEATHER UNSETTLED THROUGH LATE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
LOOKING AT A DECREASE IN COVERAGE OF THE SHOWERS THROUGH THE
REMAINDER OF THIS AFTERNOON AND EVENING AS THE SURFACE LOW FINALLY
PASSES TO THROUGH THE SOUTHERN ZONES AND TOWARDS THE MID ATLANTIC
COAST. AS WE DRY OUT FROM THE RAINFALL LAST NIGHT AND TODAY...WE
WILL NOT BE ABLE TO USHER IN A DRY AIRMASS FOR THE ENTIRETY OF
THE CWA...WITH LOW LEVEL MOISTURE LINGERING IN THE COAL FIELDS
AND SOUTHERN MOUNTAINS. HIGH PRESSURE WILL BUILD IN FOR THE
NORTHERN ZONES...BUT AN INVERTED SURFACE TROUGH WILL ASSIST WITH
THE LOW LEVEL MOISTURE RETENTION. WILL ALSO KEEP LOW END POPS IN
THESE AREAS AS WELL. NO THUNDER EXPECTED THROUGH THE FORECAST.
FOLLOWED THE HRRR FOR THE DEVELOPMENT OF THE POPS THROUGH 00Z
WEDNESDAY. NORTHWESTERN ZONES WILL SEE SOME CLEARING TONIGHT.
IN THE UPPER LEVELS...GETTING A BRIEF REPRIEVE WITH MODEST RIDGING
TONIGHT INTO WEDNESDAY BEFORE THE NEXT ROUND OF EMBEDDED VORTICITY
MAXIMA IN THE 500MB FLOW ARRIVES IN THE TUG FORK VALLEY.
NORTHERN HALF OF THE CWA WILL LIKELY BE WARMER THAN THE SOUTHERN
HALF GIVEN THE CLEARER CONDITIONS ON WEDNESDAY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
MODELS HAVE A MEAN UPPER TROUGH CONTINUING OVER THE WEST CENTRAL
PORTION OF THE NATION...WITH RATHER WEAK SOUTHWEST FLOW ALOFT
EXTENDING ACROSS THE OHIO AND TENNESSEE VALLEYS. THERE WILL BE WEAK
UPPER IMPULSES IN THIS SOUTHWEST FLOW ALOFT...BUT IT APPEARS MOST
MODELS FOCUS ON ONE THAT COMES ACROSS THURSDAY INTO THURSDAY NIGHT.
ALTHOUGH HIGH PRESSURE CENTERED OVER THE MID ATLANTIC STATES WILL BE
THE DOMINANT FEATURE AT THE SURFACE...THIS UPPER FEATURE APPEARS TO
HAVE ENOUGH DYNAMICS AND MOISTURE TO SQUEEZE OUT A HIGH POP AND LOW
QPF FORECAST THURSDAY AND EARLY THURSDAY NIGHT. OTHERWISE...HAVE TO
KEEP AT LEAST SLIGHT POPS IN MOST OF THE PERIOD...GIVEN THE
UNCERTAINTY OF OTHER IMPULSES ALOFT. THERE WILL BE LOTS OF CLOUDS
OUTSIDE OF ANY SHOWERS...ESPECIALLY THURSDAY...BUT LITTLE THUNDER
WITH MARGINAL MODEL INSTABILITY AT BEST. TEMPERATURES WILL BE
MODERATE WITH HIGHS THURSDAY IN THE MID 60S UNDER CLOUDS AND
SHOWERS...AND IN THE LOWER 70S FRIDAY WITH LESS SHOWERS AND PERHAPS
SOME SUNSHINE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
PERIOD BEGINS WITH THE AREA DOMINATED BY A WEAK SOUTHERN STREAM
JET...WITH THE ELEPHANT IN THE ROOM BEING THE NORTHERN JET...WHICH
SUPPOSEDLY WORKS ITS WAY FARTHER AND FARTHER S...AS MEAN L/W
TROUGHINESS SETS UP OVER THE CENTRAL AND EASTERN CONUS.
AT THE SFC...SRLY FLOW OUT OF THE GULF BRINGS INCREASING MOISTURE
NWD INTO THE AREA THU NT INTO SAT...BEFORE A COLD FRONT INTERCEPTS
THIS FLOW LATE SAT OR SAT NT. THE SWD PENETRATION OF THIS FRONT
DEPENDS UPON THE DEGREE OF INTRUSION OF THE ASSOCIATED NRN STREAM
S/W TROUGH INTO THE CONUS...AS A SRN STREAM CLOSED OFF LOW BEGINS
MOVING NEWD OUT OF THE DEEP S. THIS IS WHERE MODELS BEGIN TO
DIVERGE CONSIDERABLY...MAKING FOR A RATHER UNCERTAIN FCST. ROLLED
WITH SCHC ACROSS MUCH OF THE AREA SAT NT AND SUN...THESE ARE THE
LOWEST POPS IN THE FCST.
EITHER WAY...THE NRN STREAM LIFTS OUT SUN...ALLOWING THE THE SRN
STREAM UPPER LOW TO APPROACH...AND THEN MOVE ON THROUGH SUN NT.
THIS BRINGS UNSETTLED WEATHER BACK INTO THE AREA. NRN STREAM FLOW
TROUGH AMPLIFICATION OVER THE CENTRAL AND ERN CONUS BEGINS EARLY
NEXT WEEK. MODELS ACTUALLY SHOW PHASING WITH THE SRN STREAM UPPER
LEVEL LOW ONCE THAT FEATURE IS PASSED THE AREA. THIS SHOULD LEAD TO
CONTINUED UNSETTLED WEATHER THROUGH DAY 7 NT...AND...EVENTUALLY...A
TREND TOWARD COOLER WEATHER AS WELL.
NOT MUCH TEMPERATURE CHANGES IN A PATTERN FRAUGHT WITH UNCERTAINTY
AS TO THE TIMING OF CLOUDS AND PRECIPITATION. THE FCST IS ALSO
CLOSE TO WPC...AND BIAS CORRECTED ECMWF EXCEPT THE WEEKEND...WHEN
ITS DRY COOL SOLN IS THE ODD ONE OUT.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
EXPECTING A SLOW DECREASE/SCATTERING OF THE SHOWERS ACROSS THE
AREA THROUGH THE EVENING AND INTO TONIGHT. SOUTHERN AND MOUNTAIN
TERMINALS WILL REMAIN SOCKED INTO THE LOWER MVFR CEILINGS/IFR
CEILINGS AT BKW WITHOUT ANY APPRECIABLE CHANGE OF AIRMASS IN THESE
LOCATIONS. SHOWERS WILL BE POSSIBLE THROUGH THE DURATION IN THE
SOUTHERN TERMINALS...BUT NOT HIGH ENOUGH CHANCE TO REQUIRE WEATHER
IN THE PREVAILING CONDITIONS. NORTHEASTERLY WINDS WILL ALSO BE A
PLAYER IN THE LOW CEILINGS IN THIS FORECAST.
EXPECT THE VISIBILITIES TO COME BACK TO VFR ONCE THE SHOWERS
END WITH WINDS IN THE 5-10KT RANGE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING OF SHOWERS ENDING MAY VARY. CEILINGS
COULD LIFT SOONER THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H L H H L L L
HTS CONSISTENCY H H H H H H M M M M M M
BKW CONSISTENCY H H H H H H H H M M M M
EKN CONSISTENCY M M M M M M M M H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY M M M M M M M M H H H H
AFTER 18Z WEDNESDAY...
IFR CONDITIONS POSSIBLE IN SHOWERS AND POSSIBLE THUNDERSTORMS AT
VARIOUS TIMES THRU THE WEEK.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR WVZ005-013-015-016-
018-024>030-033>040-046-047.
OH...NONE.
KY...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR KYZ105.
VA...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR VAZ003-004.
&&
$$
SYNOPSIS...JMV/26
NEAR TERM...26
SHORT TERM...JMV
LONG TERM...TRM
AVIATION...26
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
223 PM EDT TUE APR 14 2015
.SYNOPSIS...
LOW PRESSURE PASSES TO THE SOUTH. HIGH PRESSURE TRACKS NORTH OF
THE AREA LATE TONIGHT AND INTO WEDNESDAY. WEAK DISTURBANCES KEEP
THE WEATHER UNSETTLED THROUGH LATE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
LOOKING AT A DECREASE IN COVERAGE OF THE SHOWERS THROUGH THE
REMAINDER OF THIS AFTERNOON AND EVENING AS THE SURFACE LOW FINALLY
PASSES TO THROUGH THE SOUTHERN ZONES AND TOWARDS THE MID ATLANTIC
COAST. AS WE DRY OUT FROM THE RAINFALL LAST NIGHT AND TODAY...WE
WILL NOT BE ABLE TO USHER IN A DRY AIRMASS FOR THE ENTIRETY OF
THE CWA...WITH LOW LEVEL MOISTURE LINGERING IN THE COAL FIELDS
AND SOUTHERN MOUNTAINS. HIGH PRESSURE WILL BUILD IN FOR THE
NORTHERN ZONES...BUT AN INVERTED SURFACE TROUGH WILL ASSIST WITH
THE LOW LEVEL MOISTURE RETENTION. WILL ALSO KEEP LOW END POPS IN
THESE AREAS AS WELL. NO THUNDER EXPECTED THROUGH THE FORECAST.
FOLLOWED THE HRRR FOR THE DEVELOPMENT OF THE POPS THROUGH 00Z
WEDNESDAY. NORTHWESTERN ZONES WILL SEE SOME CLEARING TONIGHT.
IN THE UPPER LEVELS...GETTING A BRIEF REPRIEVE WITH MODEST RIDGING
TONIGHT INTO WEDNESDAY BEFORE THE NEXT ROUND OF EMBEDDED VORTICITY
MAXIMA IN THE 500MB FLOW ARRIVES IN THE TUG FORK VALLEY.
NORTHERN HALF OF THE CWA WILL LIKELY BE WARMER THAN THE SOUTHERN
HALF GIVEN THE CLEARER CONDITIONS ON WEDNESDAY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
HIGH PRESSURE STAYS IN CONTROL KEEPING MOST OF THE AREA DRY FOR
WEDNESDAY. THE EXCEPTION WILL BE THE EXTREME SOUTHERN SECTIONS OF
WV...SOUTHWEST VA...AND NORTHEAST OH WHERE MODELS INDICATE WINDS
WILL SHIFT FROM THE SOUTH BRINGING MOISTURE BACK TO THE
AREA...ALONG WITH PASSING MID LEVEL WEAK SHORT WAVES. THE NAM AND
CMC SHOW THIS MOISTURE IN THEIR QPF FIELDS ON THESE AREAS.
THEREFORE...KEPT CHANCE POPS TO ACCOUNT FOR RAIN SHOWERS. ALMOST
NO INSTABILITY IS NOTED...SO KEPT THUNDER OUT OF THE FORECAST.
A SERIES OF MID LEVEL WAVES WILL CONTINUE TO PASS...AS SEEN ON
WEAK VORTICITY MAXES...UNDER A MID LEVEL RIDGE WEDNESDAY NIGHT
AND THURSDAY. AS MOISTURE INCREASES UNDER SOUTH SOUTHEASTERLY
FLOW...SO THE POPS ACROSS THE AREA UP TO 50 PERCENT BY THURSDAY.
FORECAST BECOMES TRICKY AS THE INFLUENCE OF THESE MID LEVEL SHORT
WAVES WILL HAVE OVER THE AREA THROUGH THURSDAY NIGHT. THEREFORE...KEPT
CHANCE POPS THROUGH THURSDAY NIGHT.
WENT CLOSER TO THE ALL BLEND NUMBERS FOR TEMPERATURES THROUGH THE
PERIOD.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
PERIOD BEGINS WITH THE AREA DOMINATED BY A WEAK SOUTHERN STREAM
JET...WITH THE ELEPHANT IN THE ROOM BEING THE NORTHERN JET...WHICH
SUPPOSEDLY WORKS ITS WAY FARTHER AND FARTHER S...AS MEAN L/W
TROUGHINESS SETS UP OVER THE CENTRAL AND EASTERN CONUS.
AT THE SFC...SRLY FLOW OUT OF THE GULF BRINGS INCREASING MOISTURE
NWD INTO THE AREA THU NT INTO SAT...BEFORE A COLD FRONT INTERCEPTS
THIS FLOW LATE SAT OR SAT NT. THE SWD PENETRATION OF THIS FRONT
DEPENDS UPON THE DEGREE OF INTRUSION OF THE ASSOCIATED NRN STREAM
S/W TROUGH INTO THE CONUS...AS A SRN STREAM CLOSED OFF LOW BEGINS
MOVING NEWD OUT OF THE DEEP S. THIS IS WHERE MODELS BEGIN TO
DIVERGE CONSIDERABLY...MAKING FOR A RATHER UNCERTAIN FCST. ROLLED
WITH SCHC ACROSS MUCH OF THE AREA SAT NT AND SUN...THESE ARE THE
LOWEST POPS IN THE FCST.
EITHER WAY...THE NRN STREAM LIFTS OUT SUN...ALLOWING THE THE SRN
STREAM UPPER LOW TO APPROACH...AND THEN MOVE ON THROUGH SUN NT.
THIS BRINGS UNSETTLED WEATHER BACK INTO THE AREA. NRN STREAM FLOW
TROUGH AMPLIFICATION OVER THE CENTRAL AND ERN CONUS BEGINS EARLY
NEXT WEEK. MODELS ACTUALLY SHOW PHASING WITH THE SRN STREAM UPPER
LEVEL LOW ONCE THAT FEATURE IS PASSED THE AREA. THIS SHOULD LEAD TO
CONTINUED UNSETTLED WEATHER THROUGH DAY 7 NT...AND...EVENTUALLY...A
TREND TOWARD COOLER WEATHER AS WELL.
NOT MUCH TEMPERATURE CHANGES IN A PATTERN FRAUGHT WITH UNCERTAINTY
AS TO THE TIMING OF CLOUDS AND PRECIPITATION. THE FCST IS ALSO
CLOSE TO WPC...AND BIAS CORRECTED ECMWF EXCEPT THE WEEKEND...WHEN
ITS DRY COOL SOLN IS THE ODD ONE OUT.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
EXPECTING A SLOW DECREASE/SCATTERING OF THE SHOWERS ACROSS THE
AREA THROUGH THE EVENING AND INTO TONIGHT. SOUTHERN AND MOUNTAIN
TERMINALS WILL REMAIN SOCKED INTO THE LOWER MVFR CEILINGS/IFR
CEILINGS AT BKW WITHOUT ANY APPRECIABLE CHANGE OF AIRMASS IN THESE
LOCATIONS. SHOWERS WILL BE POSSIBLE THROUGH THE DURATION IN THE
SOUTHERN TERMINALS...BUT NOT HIGH ENOUGH CHANCE TO REQUIRE WEATHER
IN THE PREVAILING CONDITIONS. NORTHEASTERLY WINDS WILL ALSO BE A
PLAYER IN THE LOW CEILINGS IN THIS FORECAST.
EXPECT THE VISIBILITIES TO COME BACK TO VFR ONCE THE SHOWERS
END WITH WINDS IN THE 5-10KT RANGE.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z WEDNESDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING OF SHOWERS ENDING MAY VARY. CEILINGS
COULD LIFT SOONER THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H L H H L L L
HTS CONSISTENCY H H H H H H M M M M M M
BKW CONSISTENCY H H H H H H H H M M M M
EKN CONSISTENCY M M M M M M M M H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY M M M M M M M M H H H H
AFTER 18Z WEDNESDAY...
IFR CONDITIONS POSSIBLE IN SHOWERS AND POSSIBLE THUNDERSTORMS AT
VARIOUS TIMES THRU THE WEEK.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR WVZ005-013-015-016-
018-024>030-033>040-046-047.
FLOOD WATCH UNTIL 3 PM EDT THIS AFTERNOON FOR WVZ006>008-014.
OH...FLOOD WATCH UNTIL 3 PM EDT THIS AFTERNOON FOR OHZ085>087.
KY...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR KYZ105.
FLOOD WATCH UNTIL 3 PM EDT THIS AFTERNOON FOR KYZ101>103.
VA...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR VAZ003-004.
&&
$$
SYNOPSIS...ARJ/26
NEAR TERM...26
SHORT TERM...ARJ
LONG TERM...TRM
AVIATION...26
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
156 PM EDT TUE APR 14 2015
.SYNOPSIS...
HIGH PRESSURE IN THE GREAT LAKES AND LOW PRESSURE IN THE TENNESSEE
VALLEY WILL HAVE A COOL AIRMASS OVER THE OHIO VALLEY WITH RAIN ENDING
OVER THE SOUTHERN OHIO VALLEY THIS MORNING. THE HIGH WILL CONTINUE
TO PUSH DRIER AND SOMEWHAT COOL AIR TO THE REGION THROUGH
WEDNESDAY. A SURFACE TROUGH WILL NOSE NORTHEAST INTO OHIO ON
THURSDAY AND BRING AN INCREASED THREAT FOR MORE SHOWERS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SURFACE LOW PRESSURE SYSTEM OVER THE CENTRAL TENNESSEE VALLEY
WILL PUSH OFF TO THE EAST THROUGH THIS AFTERNOON. WIDESPREAD RAIN
ASSOCIATED WITH THIS CONTINUES TO AFFECT PRIMARILY AREAS TO OUR
SOUTH...BUT THERE HAS BEEN AN EVER SO SLIGHT NORTHWARD PUSH TO
THE PCPN SHIELD IN THE LAST FEW HOURS. THE LATEST RAP SEEMS TO
HAVE THE BEST HANDLE ON THE SITUATION AND IS HANGING ON TO A WEAK
850-700 MB DEFORMATION AXIS ACROSS OUR SOUTHERN AREAS THROUGH
EARLY AFTERNOON. BASED ON THIS AND RADAR TRENDS...WILL NUDGE UP
POPS ACROSS OUR FAR SOUTH THROUGH THE REST OF THE MORNING. AS THE
LOW BEGINS TO PUSH OFF TO THE EAST...PCPN SHOULD TAPER OFF
THROUGH THIS AFTERNOON. EXPECT COOLEST TEMPS TODAY ACROSS OUR FAR
SOUTH DUE TO THE CLOUDS AND PCPN WITH HIGHS. GENERALLY EXPECT HIGHS
IN THE LOW TO MID 60S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
NORTHEAST WIND WILL CONTINUE TO BRING IN DRIER AIR TO THE OHIO
VALLEY ALONG WITH A GENERALLY MUTED AND STAGNANT TEMPERATURE
CHANGE OVER THE NEXT FEW DAYS. READINGS SHOULD TOP OUT IN THE MID
60S WED AND THURS AND WARM TO THE UPPER 60S FRIDAY. OVERNIGHT LOWS
WILL DIP TO THE LOW AND MID 40S TONIGHT AND SLOWLY RISE TO THE
LOWER 50S THURSDAY NIGHT.
AN INVERTED TROUGH WILL NOSE NORTHEAST INTO OHIO WED NIGHT AND SEE
INCREASED SHOWER ACTIVITY WITH IT. MODELS ARE DISJOINTED IN THE
AREAL COVERAGE OF QPF THURSDAY AND OVERNIGHT...AND THE INVERTED
TROUGH TYPICALLY IS NOT ENOUGH ON ITS OWN TO BRING WIDESPREAD
SHOWERS. H5 RIDGE IN PLACE WEDNESDAY WILL BREAK DOWN AND MOVE EAST
THURSDAY WITH A LOBE OF VORTICITY IN A VERY WEAK S/W PASSING OVER
THE REGION AT 0Z FRI. H5 FLOW IS GENERALLY ZONAL WESTERLY BEYOND
THIS PERIOD.
ADJUSTED WEATHER TO REMOVE THUNDER THROUGH SATURDAY AS NO FOCUS
FOR DEEP CONVECTION APPEARS TO PRESENT ITSELF IN THE FORECAST
THROUGH THIS TIME. AN ISOLATED RUMBLE CAN`T BE RULED OUT BUT THE
DAY1-3 OUTLOOK DID NOT INCLUDE THE REGION IN GENERAL THUNDER SO I
EXTENDED THIS IDEA INTO DAY 4.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
MODEL SOLN DIFFERENCES DEVELOP WITH GFS KEEPING THE AREA WET AND
PHASING THE FLOWS. MEANWHILE...ECMWF/CMC/DGEX KEEP A SPLIT FLOW.
WILL FOLLOW THIS SPLIT FLOW SOLN WITH INITIAL WAVE PASSING TO THE
EAST BUT ANOTHER NRN S/W PASSING THRU LATE FRIDAY NIGHT. THIS WILL
KEEP A CHANCE OF PCPN INTO LATE FRIDAY NIGHT/EARLY SATURDAY TIME
FRAME.
WILL THEN ALLOW FOR A DRY PERIOD LATER SATURDAY AND SUNDAY WITH MID
LEVEL RIDGE BUILDING INTO THE GREAT LAKES/OHIO VALLEY. TEMPERATURES
TO STAY ABOVE NORMAL WITH HIGHS NEXT WEEKEND FROM THE LOWER 60S FAR
N TO NEAR 70 FAR SOUTH.
ANOTHER CHANCE FOR SHOWERS/THUNDERSTORMS RETURNS LATE SUNDAY
NIGHT/MONDAY AS THE NEXT S/W AND ASSOCIATED SFC LOW ARE EXPECTED TO
EJECT NE INTO THE OHIO VALLEY.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
A SURFACE LOW PRESSURE SYSTEM OVER THE TENNESSEE VALLEY WILL
CONTINUE TO SHIFT OFF TO THE EAST THROUGH EARLY EVENING. PCPN
ASSOCIATED WITH THIS HAS GENERALLY REMAINED SOUTH OF KCVG/KLUK
BUT SUPPOSE THEY COULD STILL SEE A FEW SPRINKLES OVER THE NEXT
HOUR OR SO. OTHERWISE...ANY PCPN THREAT FOR THEM SHOULD CUT OFF
THROUGH MID AFTERNOON AS DRYING BEGINS WORKING IN FROM THE WEST.
RIDGING WILL THEN BUILD INTO THE AREA TONIGHT INTO WEDNESDAY WITH
PRIMARILY JUST SOME MID AND HIGH LEVEL CLOUDINESS EXPECTED. WE WILL
START TO GET INTO SOME DEVELOPING ISENTROPIC LIFT LATER IN THE
DAY ON WEDNESDAY AND THIS WILL LIKELY LEAD TO A LOWERING VFR DECK
TOWARD THE END OF THE KCVG TAF PERIOD.
OUTLOOK...SHOWERS AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE AT
TIMES FROM WEDNESDAY NIGHT THROUGH FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...JGL
SHORT TERM...FRANKS
LONG TERM...AR
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS NORMAN OK
1233 PM CDT TUE APR 14 2015
.UPDATE...
18Z TAFS... MVFR/VFR CEILINGS THIS TAF PERIOD. A FEW MODELS
SUGGEST IFR CONDITIONS LATE TONIGHT/EARLY WED BUT FOR NOW HAVE
LEFT AT HIGHER CEILINGS. DRIZZLE/LIGHT RAIN WILL AFFECT A FEW OF
THE TAF SITES THIS AFTN BUT STORM SYSTEM IS SLOWLY MOVING ACROSS
THE AREA CAUSE PRECIP TO SLOWLY END. WINDS WILL GENERALLY BE
SHIFTING TOWARDS THE SE THROUGH THE TAF PERIOD.
&&
.PREV DISCUSSION... /ISSUED 1112 AM CDT TUE APR 14 2015/
UPDATE...
ADJUSTED RAIN CHANCES THIS AFTERNOON TO LOWER THEM IN
WESTERN OKLAHOMA AND INCREASE THEM EAST OF I-40. ALSO...ADJUSTED
HIGHS UPWARDS IN NORTHWEST OKLAHOMA AND DOWNWARDS SOUTHEAST OF
I-44. DECREASED CLOUD COVER THIS AFTERNOON IN WESTERN OKLAHOMA.
DISCUSSION...
LIGHT RAIN WILL SLOWLY DECREASE IN COVERAGE THIS AFTERNOON AS
THE MID/UPPER LOW DEPARTS THE AREA.
LATEST RADARS INDICATED AREAS OF LIGHT RAIN/SPRINKLES MAINLY EAST
OF A CHEROKEE TO ALTUS TO CROWELL LINE. TWO AREAS OF HIGHER
COVERAGE EXISTED FROM NEAR PAULS VALLEY TO MCALESTER AND ANOTHER
AREA WAS EAST OF ENID TO PERRY TO JUST SOUTH OF PONCA CITY.
ADJUSTED RAIN CHANCES TO ACCOUNT FOR THESE AREAS. ADDITIONAL
RAINFALL TODAY MAY BE UP TO ONE HALF INCH IN THESE LOCATIONS.
STILL BELIEVE LIGHT RAIN COVERAGE WILL DECREASE THIS AFTERNOON IN
AGREEMENT WITH THE LATEST HRRR RUNS. THUS TWEAKED RAIN CHANCES
ACCORDINGLY. ADDITIONAL RAINFALL WILL ONLY BE A FEW HUNDREDTHS IN
MANY LOCATIONS. BELIEVE RAIN HAS ENDED WEST OF A CHEROKEE TO ALTUS
LINE.
CLOUD COVER AND RAIN WILL KEEP TEMPERATURES DOWN TODAY...
ESPECIALLY SOUTHEAST OF I-44 WHERE MOISTURE IS DEEPEST...SO
LOWERED TEMPERATURES. ON THE OTHER HAND...SOME CLEARING IS ALREADY
OCCURRING IN WESTERN OKLAHOMA...SO TEMPERATURES WERE INCREASED
THERE.
PRODUCTS HAVE BEEN UPDATED.
MBS
PREV DISCUSSION... /ISSUED 425 AM CDT TUE APR 14 2015/
DISCUSSION...
UPPER LOW OVER SOUTHWEST OKLAHOMA CONTINUES TO WADDLE SLOWLY
NORTHEAST. EXPECT SHOWERS TO PERSIST IN THE AREA AS THIS SYSTEM
MOVES NORTHEAST. A BREAK IN THE PRECIPITATION CHANCES OCCURS
TOMORROW AS THIS SYSTEM MOVES OUT BEFORE THE NEXT SYSTEM
APPROACHES FROM THE CENTRAL ROCKIES AND PRECIP CHANCES INCREASE
FROM THE WEST WEDNESDAY NIGHT AND PERSIST INTO THE WEEKEND DUE TO
THE SLOW MOVEMENT OF THIS SYSTEM OVER THE PLAINS. IT WILL BE A WET
PATTERN IN GENERAL FOR A FEW DAYS... BUT THE SPECIFIC DAY-TO-DAY
POPS AND GEOGRAPHY ARE A STILL SOMEWHAT UNCERTAIN AND WILL DEPEND
ON THE PATH AND SPEED OF THIS SYSTEM.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 59 49 73 56 / 70 30 10 20
HOBART OK 62 44 76 56 / 60 10 10 30
WICHITA FALLS TX 60 48 78 58 / 30 10 10 20
GAGE OK 68 43 75 51 / 10 10 10 30
PONCA CITY OK 62 47 71 54 / 70 30 10 20
DURANT OK 59 53 74 57 / 40 30 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
17/25
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1112 AM CDT TUE APR 14 2015
.UPDATE...
ADJUSTED RAIN CHANCES THIS AFTERNOON TO LOWER THEM IN
WESTERN OKLAHOMA AND INCREASE THEM EAST OF I-40. ALSO...ADJUSTED
HIGHS UPWARDS IN NORTHWEST OKLAHOMA AND DOWNWARDS SOUTHEAST OF
I-44. DECREASED CLOUD COVER THIS AFTERNOON IN WESTERN OKLAHOMA.
&&
.DISCUSSION...
LIGHT RAIN WILL SLOWLY DECREASE IN COVERAGE THIS AFTERNOON AS
THE MID/UPPER LOW DEPARTS THE AREA.
LATEST RADARS INDICATED AREAS OF LIGHT RAIN/SPRINKLES MAINLY EAST
OF A CHEROKEE TO ALTUS TO CROWELL LINE. TWO AREAS OF HIGHER
COVERAGE EXISTED FROM NEAR PAULS VALLEY TO MCALESTER AND ANOTHER
AREA WAS EAST OF ENID TO PERRY TO JUST SOUTH OF PONCA CITY.
ADJUSTED RAIN CHANCES TO ACCOUNT FOR THESE AREAS. ADDITIONAL
RAINFALL TODAY MAY BE UP TO ONE HALF INCH IN THESE LOCATIONS.
STILL BELIEVE LIGHT RAIN COVERAGE WILL DECREASE THIS AFTERNOON IN
AGREEMENT WITH THE LATEST HRRR RUNS. THUS TWEAKED RAIN CHANCES
ACCORDINGLY. ADDITIONAL RAINFALL WILL ONLY BE A FEW HUNDREDTHS IN
MANY LOCATIONS. BELIEVE RAIN HAS ENDED WEST OF A CHEROKEE TO ALTUS
LINE.
CLOUD COVER AND RAIN WILL KEEP TEMPERATURES DOWN TODAY...
ESPECIALLY SOUTHEAST OF I-44 WHERE MOISTURE IS DEEPEST...SO
LOWERED TEMPERATURES. ON THE OTHER HAND...SOME CLEARING IS ALREADY
OCCURRING IN WESTERN OKLAHOMA...SO TEMPERATURES WERE INCREASED
THERE.
PRODUCTS HAVE BEEN UPDATED.
MBS
&&
.PREV DISCUSSION... /ISSUED 425 AM CDT TUE APR 14 2015/
DISCUSSION...
UPPER LOW OVER SOUTHWEST OKLAHOMA CONTINUES TO WADDLE SLOWLY
NORTHEAST. EXPECT SHOWERS TO PERSIST IN THE AREA AS THIS SYSTEM
MOVES NORTHEAST. A BREAK IN THE PRECIPITATION CHANCES OCCURS
TOMORROW AS THIS SYSTEM MOVES OUT BEFORE THE NEXT SYSTEM
APPROACHES FROM THE CENTRAL ROCKIES AND PRECIP CHANCES INCREASE
FROM THE WEST WEDNESDAY NIGHT AND PERSIST INTO THE WEEKEND DUE TO
THE SLOW MOVEMENT OF THIS SYSTEM OVER THE PLAINS. IT WILL BE A WET
PATTERN IN GENERAL FOR A FEW DAYS... BUT THE SPECIFIC DAY-TO-DAY
POPS AND GEOGRAPHY ARE A STILL SOMEWHAT UNCERTAIN AND WILL DEPEND
ON THE PATH AND SPEED OF THIS SYSTEM.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 59 49 73 56 / 70 30 10 20
HOBART OK 62 44 76 56 / 60 10 10 30
WICHITA FALLS TX 60 48 78 58 / 30 10 10 20
GAGE OK 68 43 75 51 / 10 10 10 30
PONCA CITY OK 62 47 71 54 / 70 30 10 20
DURANT OK 59 53 74 57 / 40 30 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
17/25
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
126 PM CDT TUE APR 14 2015
.UPDATE...
18Z TAF DISCUSSION.
&&
.AVIATION...
CURRENT VFR/MVFR CIGS TO BECOME IFR/MVFR LATE THIS
AFTERNOON/EVENING THEN LIFR/IFR OVERNIGHT AS NEXT WAVE OF -SHRA
SPREADS INTO THE MID STATE. EXPECT -SHRA TO REACH AIRPORTS AROUND
15/03-04Z PER HRRR WITH MVFR VIS. NORTH WINDS ANTICIPATED AT
CKV/BNA THROUGH THE TAF PERIOD...WHILE CURRENT SOUTHWEST WINDS AT
CSV BECOME NORTHWEST THEN NORTH AFTER FROPA AT 14/19Z.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 1017 AM CDT TUE APR 14 2015/
UPDATE...
MAIN AREA OF RAIN HAS PUSHED NORTH OF THE MID STATE INTO THE KENTUCKY
AT THIS HOUR WILL A FEW TRAILING SHOWERS DOWN INTO MIDDLE TENNESSEE
GENERALLY EAST OF INTERSTATE 65. 1015 MBAR SURFACE LOW CENTERED
BETWEEN NASHVILLE AND CROSSVILLE AT 14Z WITH FRONTAL BOUNDARY DRAPED
DOW THROUGH NORTHEAST MISSISSIPPI INTO ANOTHER LOW IN NORTHEAST
LOUISIANA. A LITTLE COOLER TEMPS FAR NORTHERN MIDDLE TENNESSEE
NORTHWARD. MODELS TAKE SURFACE LOW IN EASTERN MIDDLE TENNESSEE
TO THE EAST AND OFF THE PLATEAU THIS AFTERNOON. LOOKS LIKE THE
SURFACE BOUNDARY WILL REMAIN CLOSE TO OUR AREA NEXT 24 HOURS WITH
ANOTHER ORGANIZED ROUND OF RAIN COMING LATER TONIGHT AND ON
WEDNESDAY...ALTHOUGH MODELS TRY AND HOLD BULK OF THAT RAIN JUST TO
OUR SOUTH AND SHUNT IT OFF TOWARDS NORTH GEORGIA DURING THE DAY ON
WEDNESDAY...RAIN DOES LOOK LIKELY ON WEDNESDAY.
WATER VAPOR DOES SHOW SOME DRYING WORKING INTO THE AREA WHILE LAST
SEVERAL LAPS SOUNDINGS HAVE TRENDED TOWARDS DRYING ABOVE 700
MBARS. IF THIS TREND CONTINUES WE COULD SEE A FEW PEAKS OF SUN
BY AFTERNOON. HIGHS TODAY IN THE MID AND UPPER 60S NORTHWEST HALF
WITH LOWER 70S SOUTHEAST.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
344 PM CDT TUE APR 14 2015
.SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...THE UPPER LOW HAS
LIFTED NEWD OVER THE SRN PLAINS (WATER VAPOR IMAGERY/STREAMLINE
DATA) LATE THIS AFTN...DECREASING SYNOPTIC SCALE LIFT OVER THE
CWA/MSA. LATEST MSAS SUGGEST A WEAK BOUNDARY SW-NE ACRS THE CWA.
LATEST LAPS ANALYSIS DEPICTS MAX CAPE VALUES NEAR 1000 J/KG OVER
PORTIONS OF THE ERN CWA. EARLIER RAP OUTPUT SUGGESTED MAX CAPE
VALUES AROUND 1500 J/KG THIS EVENING. ANTICIPATE AT LEAST ISOLD
CONVECTION THIS EVENING/EARLY TNGT OVER THE CWA OWING TO LIMITED
INSTABILITY/SFC FORCING. SREF PROBABILITIES SUGGEST AT LEAST
PATCHY FOG OVER PORTIONS OF THE CWA DRG THE 09-14Z WEDNESDAY
PERIOD. WEDNESDAY...THE GFS PROG THE LFQ OF AN UPPER JET STREAK
ENTERING THE CWA BY THE AFTN. EARLIER NAM DETERMINISTIC OUTPUT
DEPICTED 2000-3500 J/KG CAPE VALUES OVER THE CWA FOR THE AFTN
HOURS. ANTICIPATE ISOD/SCT CONVECTION OVER THE CWA/MSA OWING TO
INSTABILITY/WEAKENING SFC BOUNDARY/UPPER FORCING (HOWEVER MSTR
MAY BECOME A LIMITING FACTOR OVR THE NERN CWA AS PWAT VALUES MAY
FALL TO NEAR NORMAL DRG THE AFTN.) SOME STORMS MAY BECOME STG DRG
THE AFTN/EARLY EVENING. WEDNESDAY NIGHT...THE GFS DETERMINISTIC
MAINTAIN JET DYNAMICS OVER THE CWA WHICH MAY CONTRIBUTE TO
ADDITIONAL AT LEAST ISOLD CONVECTION.
&&
.LONG TERM (THURSDAY THROUGH TUESDAY)...ACTIVE WEATHER IS EXPECTED
EARLY IN THE PERIOD AS A VERY STRONG SUBTROPICAL JET REMAINS FOCUSED
ACRS THE AREA AND MSTR/INSTABILITY RETURN. BOTH THE GFS/EURO DEPICT
50+ MID LVL SPEED MAX IMPINGING ON THE AREA THU AFTN WITH STRONG
UPPER SUPPORT IN THE FRONT LEFT QUAD OF THE UPPER JET. MSTR RETURN
LOOKS ROBUST WITH 70+ DEWPOINTS SPREADING BACK OVER THE REGION. SO
THE SVR POTNL WILL HINGE ON TOUGH TO PREDICT MESOSCALE DETAILS
CONCERNING DEGREE OF INSOLATION AND ANY LINGERING BOUNDARIES ACRS
THE RGN. AT A MINIMUM THE SYNOPTIC SETUP IS SUPPORTIVE OF SEVERE
POTENTIAL AND CONDITIONALLY COULD SUPPORT A HIGHER END EVENT.
ENOUGH SHEAR LOOKS TO BE IN PLACE SO THAT ALL MODES OF SVR WX ARE
PSBL HWVR DAMAGING WINDS/HAIL FROM MULTICELL CLUSTERS/BOWS LOOKS
MOST LIKELY. FRIDAY LOOKS POTENTIALLY ACTIVE AS WELL BUT AGAIN THE
EVOLUTION OF EARLIER CONVECTION WILL HAVE A HUGE IMPACT ON HOW
THINGS UNFOLD. AS FAR AS EXCESSIVE RAINS GO...VERY HEAVY PCPN
OVERNIGHT...4-6 INCHES IN SPOTS...HAS INCREASED OUR FLOOD THREAT
QUITE A BIT. DEEP CONVECTION COULD QUICKLY LEAD TO ADDITIONAL
FLOODING THU AND ESPLY FRI WHEN PWATS APPRCH 2 INCHES ON THE LATEST
MODELS. WILL ISSUE SPS TO ADDRESS SVR/+RA THREATS DURING THE LATE
WEEK PERIOD.
WILL LEAN TWRD SLOWER FROPA DEPICTED BY THE EURO AND KEEP POPS GOING
THRU MOST OF THE WEEKEND. AGAIN SOME POTENTIAL REMAINS FOR STRONG
STORMS AND HEAVY RAINS ON SAT. DRIER AIR SHOULD WIN OUT BY SUNDAY
AS UPPER LOW FINALLY PULLS EAST. NO MAJOR CHANGES TO PREV TEMP
FCSTS WERE MADE - GENERALLY LEANED TWRD THE COOLER HPC NUMBERS VS
THE WARMER MEX WITH THE CLOUD/PCPN.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 67 81 70 80 71 / 30 30 20 50 40
VICTORIA 63 81 67 78 68 / 30 30 20 60 40
LAREDO 63 85 69 86 70 / 20 20 20 40 30
ALICE 65 84 68 83 70 / 30 30 20 50 40
ROCKPORT 68 78 70 76 71 / 30 30 20 60 40
COTULLA 62 84 67 82 68 / 20 20 20 40 30
KINGSVILLE 66 84 69 82 71 / 30 30 20 40 30
NAVY CORPUS 68 78 70 77 71 / 30 30 20 50 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
WC/87...SHORT TERM
TJ/70...LONG TERM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
414 PM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL PUSH SOUTHEAST THROUGH THE AREA THIS EVENING. A
STRONG WEDGE OF HIGH PRESSURE WILL COVER THE REGION WEDNESDAY
THROUGH FRIDAY. ANOTHER COLD FRONT CROSS THE AREA OVER THE
WEEKEND.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AS OF 400 PM EDT TUESDAY...
MSAS ANALYSIS SHOWERS SURFACE LOW IN EXTREME SOUTHWEST VIRGINIA
ALONG A FRONT FROM SOUTHERN MARYLAND TO NORTHERN LOUISIANA.
SOUTH OF THIS BOUNDARY LIFTED INDEX VALUES WERE DOWN TO -4 WITH
CAPES IN THAT AIR MASS UP TO 1600 J/KG. THE FRONT WILL MOVE SOUTH
AS THE LOW MOVES EAST. SHORT RANGE MODELS HAD THE FRONT SOUTH OF
THE FORECAST AREA BY 02Z/10PM. HAVE SHOWERS WITH ISOLATED THUNDER
IN THE FORECAST UNTIL THE FRONT CLEARS THE SOUTHERN COUNTIES. IN
THE STABLE AIR NORTH OF THE FRONT...COVERAGE OF LIGHT RAIN WILL BE
DIMINISHING BUT UPSLOPE WILL CONTINUE WITH WIDESPREAD LOW
CLOUDS...FOG AND DRIZZLE. TEMPERATURES WILL DROP MORE NORTH OF THE
FRONT OVERNIGHT. GUIDANCE SUGGESTED THAT AS THE WEDGE CONTINUES TO
DEVELOP ON WEDNESDAY....TEMPERATURES WILL BE STEADY OR SLOWLY FALL
DURING THE DAY. USED A NON DIURNAL TEMPERATURE TREND FOR
WEDNESDAY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
AS OF 230 PM EDT TUESDAY...
AN AREA OF HIGH PRESSURE WILL WEDGE DOWN THE EAST COAST LATE
WEDNESDAY AND WILL LIKELY REMAIN IN THE REGION THROUGH THE PERIOD.
RAIN CHANCES INCREASE WEDNESDAY NIGHT AS OVERRUNNING MOISTURE IS
PUSHED OVER THE WEDGE FROM A DISTURBANCE TRACKING OVER THE OHIO
VALLEY AND ITS ASSOCIATED WARM FRONT MOVING NORTH OVER THE SOUTH-
CENTRAL APPALACHIANS. MODELS ARE DISPLAYING A SURFACE REFLECTIONS
OFF THE SOUTHEAST COAST...WHICH WILL LIKELY GENERATE CONVECTION
OFFSHORE AND LIMIT RAINFALL AMOUNTS OVER THE IMMEDIATE AREA
THURSDAY. SURFACE HIGH DRIFTS OFF THE NORTHEAST COAST WHILE THE
COASTAL REFLECTION INTENSIFIES INTO A SURFACE LOW. THE PRESSURE
GRADIENT BETWEEN THESE TWO FEATURES WILL BRING A STRONG FETCH OF
ATLANTIC MOISTURE TOWARDS THE SOUTH-CENTRAL APPALACHIANS. THE
LATEST 12Z MODELS HAVE THIS FETCH DIRECTED AT THE SOUTHWEST
VIRGINIA BLUE RIDGE. THIS MODEL FETCH OF MOISTURE WILL NEED TO BE
WATCHED ESPECIALLY IF WE REMAIN IN A WET WEATHER PATTERN THROUGH
MOST OF THE WEEK. ON FRIDAY...THE COASTAL LOW WILL KEEP CONVECTION
OFFSHORE WHILE WEAK HIGH PRESSURE DRIFTS OVER THE REGION. WEDGE
INFLUENCE LOOK TO REMAIN WITH GRAY CONDITIONS PERSISTING INTO
FRIDAY NIGHT. NOT RULING OUT ANY SUN BUT WITH A WEDGE...EASTERLY
FLOW AND MOSTLY CLOUDY SKIES...TEMPERATURES WILL BE ON THE COOL
SIDE THURSDAY AND FRIDAY.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 245 PM EDT TUESDAY...
A COLD FRONT IS EXPECTED TO STALL ACROSS THE OHIO VALLEY ON SATURDAY
WITH A POSSIBLE CLOSED LOW HOVERING OVER THE OZARKS. THERE WILL
REMAIN A GOOD FLOW OF MOISTURE INTO THE REGION FROM THE GULF THROUGH
THE WEEKEND TO KEEP HIGH CHANCE TO LIKELY POPS. THE MAIN QUESTION
REGARDING RAIN IS TIMING. HIGH PRESSURE DRIFTS OVER THE REGION EARLY
NEXT WEEK TO BRING AN END TO THE RAIN. WITH MORE CLOUDS AND RAIN IN
THE FORECAST...TEMPERATURES WILL BE COOL BUT NOT TO FAR REMOVED FROM
NORMAL.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
AS OF 145 PM EDT TUESDAY...
LOW PRESSURE WAS OVER NORTHEAST TENNESSEE ALONG A COLD FRONT THAT
EXTENDED INTO THE DELMARVA. THE FRONT WILL MOVE SOUTH THIS
AFTERNOON AND EVENING AS THE LOW MOVES EAST. THIS WILL BRING THE
WINDS AROUND TO THE NORTHEAST TO NORTH. SOME WIND GUST UP TO 25
KNOTS ARE POSSIBLE BEFORE 00Z/8PM.
A LARGE AREA OF LIGHT TO MODERATE RAIN WITH MVFR VISIBILITIES AND
IFR CEILINGS ASSOCIATED WITH THE LOW WILL ALSO MOVE EAST. BASED
ON RADAR TRENDS AND HRRR GUIDANCE...THE BACK EDGE OF THE RAIN WILL
MOVER NORTHEAST OF THE FORECAST AREA BY 23Z/7PM. AS WEDGE BUILDS
INTO THE REGION...CEILINGS WILL REMAIN MAINLY IFR TO LIFR WITH
EAST TO NORTHEAST UPSLOPE WINDS. HIGH CONFIDENCE THAT THERE WILL
BE LITTLE IMPROVEMENT THROUGH 12Z/8AM. AREAS OF FOG AND DRIZZLE
ARE LIKELY. AFTER SUNRISE...CEILINGS AND FOG MAY LIFT TO MVFR
LEVELS.
EXTENDED AVIATION...
THE WEDGE REMAINS IN PLACE THROUGH AT LEAST FRIDAY MORNING.
EXPECTING A PROLONGED PERIOD OF IFR TO MVFR CEILINGS.
ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE THE WEDGE BREAKS.
ON SATURDAY THE FRONT COMES THROUGH SHOWERS AND THUNDERSTORMS.
EXPECTING OCCASIONAL PERIODS OF MVFR CONDITIONS UNTIL THE FRONT
PASSES.
SUNDAY A DRIER AIR MASS WILL PUSH INTO THE REGION ALONG WITH HIGH
PRESSURE BEHIND THE FRONT. THIS IS A SLOWER TIMING THAN THE PAST
FEW RUNS OF THE MODELS. ONCE THIS DRIER AIR ARRIVES...CONDITIONS
SHOULD IMPROVE BACK TO VFR.
&&
.HYDROLOGY...
AS OF 410 PM EDT TUESDAY...
THE SOUTHWEST EDGE OF THE MODERATE PRECIPITATION HAD BEEN MOVING
NORTHEAST THROUGH THE FORECAST AREA IN ASSOCIATION WITH THE SHORT
WAVE OVER SOUTHWEST VIRGINIA AT 20Z/4PM. EXPECT THE SURFACE LOW
ALONG THE FRONT AND THE BOUNDARY TO CLEAR THE FORECAST AREA BY
10PM. THE AIR MASS SOUTH OF THE FRONT LATE THIS AFTERNOON AND
EVENING WILL BE JUST UNSTABLE ENOUGH TO SUPPORT ISOLATED
THUNDERSTORMS WHICH WILL MEAN HIGHER RAINFALL RATES. ONCE THE
FRONT AND SHORT WAVE CLEAR THE AREA...EXPECTED RAINFALL AMOUNTS
WILL DROP.
NO CHANGES TO THE WATCH ARE PLANNED AT THIS TIME.
A NEW FORECAST HAS BEEN ISSUED BY OHIO RIVER FORECAST CENTER FOR
THE GREENBRIER RIVER. THIS LATEST FORECAST BRINGS THE GREENBRIER
RIVER AT ALDERSON INTO ACTION STAGE LATE THIS EVENING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR VAZ007-010-011-
018>020.
FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ009-012-013-015-
016.
NC...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001>003-018>020.
WV...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR WVZ042>044-507-508.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...RCS
AVIATION...AMS/JH
HYDROLOGY...AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
205 PM EDT TUE APR 14 2015
.SYNOPSIS...
A COLD FRONT WILL SLIDE SOUTHEAST INTO THE AREA TODAY BEFORE
DROPPING SOUTH INTO THE CAROLINAS TONIGHT. A WEDGE OF HIGH
PRESSURE WILL BUILD IN BEHIND THE FRONT BY WEDNESDAY...AND LINGER
OVER THE REGION INTO AT LEAST FRIDAY. ANOTHER COLD FRONT WILL MOVE
ACROSS THE AREA OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 AM EDT TUESDAY...
FORECAST REMAINS QUITE COMPLICATED GIVEN THE SLOW MOVING COLD FRONT TO
THE WEST AND ASSOCIATED WEAK LOW PRESSURE THAT WILL SCOOT OUT OF THE TN
VALLEY AND INTO THE REGION LATER TODAY. THIS JUST AS THE FRONT FOLDS IN
FROM THE NORTH/NW ALLOWING LOW LEVEL CONVERGENCE TO MAXIMIZE THIS
MORNING INTO LATE AFTERNOON. MODELS HAVE AGAIN TRENDED FARTHER NORTH
WITH THE MAIN BAROCLINIC ZONE WHICH HAS SHIFTED THE AXIS OF BEST UPPER
DIFFLUENCE AND CORRESPONDING LIFT FARTHER NORTH/WEST. THIS WHILE
ALLOWING LESS UPSLOPE GIVEN VEERING FLOW FROM SOUTH/SE TO MORE SW AHEAD
OF THE BOUNDARY TODAY. CONSENSUS APPEARS FOR A STRIP OF HIGHER QPF FROM
SE WEST VA EAST INTO THE VA HIGHLANDS AND POINTS EAST WITH A SHARP
GRADIENT LIKELY NEAR HIGHWAY 460 AND POINTS SOUTH WHERE WILL SEE
MORE SCATTERED COVERAGE IN COMPARISON TO THE WIDESPREAD/HEAVIER
SHRA UP NORTH. HOWEVER WHERE TO DRAW THE LINE QUITE IFFY GIVEN
LIKELY TREND OF THINGS BEING OVERALL SLOWER PER THE WAVE TRACKING
NEAR BRISTOL THIS AFTERNOON BEFORE SHUNTING EAST/SE. THIS MAY
ALLOW MUCH MORE OF A DIFFERENTIAL HEATING ZONE OVER THE SOUTH
WHERE THE LATEST NAM HAS CAPES NEAR 1K J/KG ALONG THE VA/NC BORDER
PENDING MORE BREAKS AND SUBSEQUENT HEATING. SPEED MAX TRACKING
ACROSS LATE MAY ALSO SPARK CLUSTERS OF TSRA THAT COULD LINE UP
BEFORE SPILLING SOUTH. THUS BEEFING UP THUNDER MENTION SOUTH AND
INCLUDING IN THE HWO PER DAY1 MARGINAL OUTLOOK.
OTRW HAVE ADJUSTED POPS DOWN SOME TO INIT EARLY ON...WITH HIGHER CAT
POPS NORTH/WEST FOR MUCH OF THE DAY...AND SLOWLY INCREASING FROM NORTH
TO SOUTH AS THE FRONT SAGS SOUTH AND THE WAVE HEADS EAST SIMILAR TO THE
NAM. FORECAST QPF OF 1-3 INCHES ESPCLY NW PROMPTS THE NEED TO EXTEND
THE FLOOD WATCH INTO THE VA HIGHLANDS GIVEN LOW FFG AND PERHAPS FARTHER
EAST LATER PENDING TRENDS. LONGER PERIOD OF WARM ADVECTION BEFORE THE
FLOW TURNS NE...AND POSSIBLY SOME SUN SOUTH SUGGESTS HIGHS WARMER
THAN PREVIOUS WITH MOST IN THE 60S TO LOWER 70S...AND SOME MID OR
EVEN UPPER 70S POSSIBLE FAR SOUTH IF THINGS BREAK OPEN MORE.
WAVE HEADS EAST THIS EVENING ALLOWING THE SURFACE FRONT TO BOW THROUGH
THE REGION FROM THE NORTH BRINGING THE ONSET OF THE LOW LEVEL WEDGE
FROM NE TO SW OVERNIGHT. THIS SHOULD TAKE THE DEFORMATION TYPE ZONE OF
HEAVIER SHRA TO THE EAST BY MIDNIGHT WITH RESIDUAL LEFTOVER MOISTURE
MAKING FOR CONTINUED SPOTTY -RA ESPCLY SW WHERE WILL SEE A WEAK
INVERTED TROUGH DEVELOP UNDER THE EASTERLY FLOW. THUS AFTER MOSTLY
LIKELY POPS DURING THE EARLY EVENING WILL SHIFT TO A MORE CHANCE REGIME
FOR -RA AND EVEN SOME SPOTTY -DZ AS THE NIGHT WEARS ON GIVEN THE
DECREASING DEPTH TO THE MOISTURE OFF FORECAST RAOBS LATE. KEPT TEMPS
SIMILAR TO THE SLIGHTLY WARMER MET MOS PER EXPECTED SLOWER TRENDS WITH
THE DEVELOPING CAD.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 315 AM EDT TUESDAY...
EXPECTING THAT CONVECTION WILL DRIVE SFC COLD FRONT SOUTH OF US
BY WEDNESDAY MORNING ACROSS THE CAROLINAS. MAIN SHORTWAVE AND
ASSOCIATED LOW PRESSURE ALONG THE FRONT WILL BE OFFSHORE IN THE
ATLANTIC OCEAN. IN SITU CAD EVENT WILL BECOME WELL ESTABLISHED ON
WEDNESDAY. WITH CLOUDS AND RAIN...LOWERED HIGH TEMPERATURES FOR
WEDNESDAY. HIGHS FOR WEDNESDAY WILL BE BELOW NORMAL WITH READINGS
FROM AROUND 50 DEGREES IN THE MOUNTAINS TO NEAR 60 DEGREES IN THE
PIEDMONT. IN GENERAL...LEANED POPS TOWARDS THE NAM FOR WEDNESDAY AND
SHAPED OUR QPF TOWARDS HPC.
CLOUDY WITH AREAS OF RAIN AND FOG ARE ANTICIPATED WEDNESDAY NIGHT
INTO THURSDAY. PLACED HIGH POPS ACROSS THE SOUTH WHERE WEDGE UPGLIDE
OVERLAPS WITH SOME UPPER DIVERGENCE. LOW TEMPERATURES WEDNESDAY
NIGHT WILL RANGE FROM THE UPPER 30S IN THE MOUNTAINS TO THE LOWER
40S IN THE PIEDMONT. UNDERCUT MOS HIGH TEMPERATURES FOR THURSDAY
WITH PLENTY OF CLOUDS AND AREAS OF RAIN AND FOG UNDER CAD. HIGHS
WILL VARY FROM THE UPPER 40S IN THE NORTHWEST TO THE MID 50S IN THE
SOUTHEAST. THE CLOUDY DREARY WEATHER CONTINUES THURSDAY NIGHT INTO
FRIDAY WITH LOW TEMPERATURES GENERALLY FROM THE LOWER 40S IN THE
NORTHWEST MOUNTAINS TO THE LOWER 50S IN THE PIEDMONT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 215 PM EDT MONDAY...
NORTHERN STREAM TROF OVER THE NORTHEAST AMPLIFIES WITH A SURFACE
COLD FRONT COMING THROUGH THE REGION ON SATURDAY. MEANWHILE A LOW IS
CLOSED OFF OVER THE ROCKIES ON FRIDAY.
CLOSED LOW OVER THE ROCKIES OPENS UP AND ALSO TRACKS INTO THE UPPER
MISSISSIPPI VALLEY SATURDAY AND SUNDAY...WITH A PIECE OF THIS SYSTEM
REACHING THE FORECAST AREA ON MONDAY. SURFACE HIGH PRESSURE CROSSES
THE NORTHEAST UNITED STATES SUNDAY THEN BY MONDAY...ALREADY BACK IN
YET ANOTHER WEDGE WITH DEEP SOUTHEAST UPSLOPE FLOW WITH STRONG 850
WINDS.
WILL KEEP SATURDAY NIGHT THROUGH SUNDAY NIGHT DRY. WEDGE MAY BE SLOW
TO BREAK ON FRIDAY WHICH MAY LIMIT MAXIMUM TEMPERATURES. BUT
SATURDAY AHEAD OF THE FRONT WILL BE MILDER. TEMPERATURES BEHIND THE
FRONT ON SUNDAY WILL BE AROUND NORMAL.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 145 PM EDT TUESDAY...
LOW PRESSURE WAS OVER NORTHEAST TENNESSEE ALONG A COLD FRONT THAT
EXTENDED INTO THE DELMARVA. THE FRONT WILL MOVE SOUTH THIS
AFTERNOON AND EVENING AS THE LOW MOVES EAST. THIS WILL BRING THE
WINDS AROUND TO THE NORTHEAST TO NORTH. SOME WIND GUST UP TO 25
KNOTS ARE POSSIBLE BEFORE 00Z/8PM.
A LARGE AREA OF LIGHT TO MODERATE RAIN WITH MVFR VISIBILITIES AND
IFR CEILINGS ASSOCIATED WITH THE LOW WILL ALSO MOVE EAST. BASED
ON RADAR TRENDS AND HRRR GUIDANCE...THE BACK EDGE OF THE RAIN WILL
MOVER NORTHEAST OF THE FORECAST AREA BY 23Z/7PM. AS WEDGE BUILDS
INTO THE REGION...CEILINGS WILL REMAIN MAINLY IFR TO LIFR WITH
EAST TO NORTHEAST UPSLOPE WINDS. HIGH CONFIDENCE THAT THERE WILL
BE LITTLE IMPROVEMENT THROUGH 12Z/8AM. AREAS OF FOG AND DRIZZLE
ARE LIKELY. AFTER SUNRISE...CEILINGS AND FOG MAY LIFT TO MVFR
LEVELS.
EXTENDED AVIATION...
THE WEDGE REMAINS IN PLACE THROUGH AT LEAST FRIDAY MORNING.
EXPECTING A PROLONGED PERIOD OF IFR TO MVFR CEILINGS.
ON FRIDAY...LOW LEVEL FLOW TURNS TO THE SOUTHWEST IN ADVANCE OF A
COLD FRONT. ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE IN THE AFTERNOON...ESPECIALLY ONCE THE WEDGE BREAKS.
ON SATURDAY THE FRONT COMES THROUGH SHOWERS AND THUNDERSTORMS.
EXPECTING OCCASIONAL PERIODS OF MVFR CONDITIONS UNTIL THE FRONT
PASSES.
SUNDAY A DRIER AIR MASS WILL PUSH INTO THE REGION ALONG WITH HIGH
PRESSURE BEHIND THE FRONT. THIS IS A SLOWER TIMING THAN THE PAST
FEW RUNS OF THE MODELS. ONCE THIS DRIER AIR ARRIVES...CONDITIONS
SHOULD IMPROVE BACK TO VFR.
&&
.HYDROLOGY...
AS OF 330 AM EDT TUESDAY...
SHOWERS REMAIN SCATTERED ACROSS THE REGION EARLY THIS MORNING WITH
THE FRONT STILL WELL TO THE NW AND LOW PRESSURE OVER THE TN
VALLEY. LATEST HRRR SHOWS A SLOW FILLING IN OF PRECIP THROUGH THE
MORNING WITH THE MOST WIDESPREAD COVERAGE ESPCLY NORTHERN HALF
FROM MIDDAY THROUGH LATE AFTERNOON.
EXPECTED RAINFALL FOR MUCH OF THE FORECAST AREA WILL BE ONE TO TWO
INCHES EARLY WEDNESDAY. HOWEVER MODELS HAVE SHIFTED THE HEAVIER
AXIS OF PROJECTED RAINFALL NORTH ACROSS PARTS OF SOUTHEAST WEST
VIRGINIA INTO THE VIRGINIA HIGHLANDS WHERE POTENTIAL FOR TWO TO
THREE INCHES LOOKS POSSIBLE. GUIDANCE VALUES FOR RAINFALL IT WOULD
TAKE TO PRODUCE FLOODING ARE BELOW TWO INCHES FOR THE MOUNTAINS
AND ONLY AROUND AN INCH ACROSS THE VIRGINIA HIGHLANDS SO THE FLOOD
WATCH HAS BEEN EXTENDED TO COVER THOSE AREAS AS WELL. LIGHT TO
MODERATE RAIN WILL CONTINUE INTO THURSDAY ALONG THE BLUE RIDGE AND
IN THE FOOTHILLS IN FAR SOUTHWEST VIRGINIA INTO NORTHWEST NORTH
CAROLINA.
AT THIS TIME...THERE IS A LOW PROBABILITY OF MINOR MAINSTEM RIVER
FLOODING THROUGH THURSDAY. AREAL FLOODING OF SMALL STREAMS AND
CREEKS IS WHAT IS MORE LIKELY IF THE EXPECTED AMOUNT OF RAINFALL
OCCURS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR VAZ007-010-011-
018>020.
FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ009-012-013-015-
016.
NC...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ001>003-018>020.
WV...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR WVZ042>044-507-508.
&&
$$
SYNOPSIS...DS/JH
NEAR TERM...JH
SHORT TERM...KK
LONG TERM...AMS
AVIATION...AMS/JH
HYDROLOGY...AMS/JH
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1231 PM CDT TUE APR 14 2015
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY
ISSUED AT 308 AM CDT TUE APR 14 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SPLIT FLOW
ACROSS NORTH AMERICA CONSISTING OF A RIDGE OVER THE ROCKIES...A
TROUGH OVER THE SOUTHERN PLAINS...AND CONVERGING UPPER FLOW ACROSS
THE EAST. THE WESTERN GREAT LAKES RESIDES DOWNSTREAM OF THE
RIDGE...WITH STRONG SUBSIDENCE LEADING TO CLEAR CONDITIONS ACROSS
THE REGION. THE AIRMASS ITSELF IS VERY DRY WITH PWATS FALLING BELOW
A QUARTER OF AN INCH. AS THE DRY SURFACE HIGH MOVES ACROSS THE
REGION...TEMPS AND HUMIDITIES ARE THE MAIN FORECAST CONCERNS THROUGH
WEDNESDAY.
TODAY...HIGH PRESSURE WILL DRIFT ACROSS THE REGION...WHICH WILL
PROMOTE CLEAR SKIES AND LIGHT WINDS. EVEN THOUGH UPSTREAM OBS SAW
DEWPOINTS CRASH INTO THE SINGLE DIGITS OVER MINNESOTA AND NORTH
DAKOTA IN THIS AIRMASS...SHOULD NOT HAVE THE KIND OF MECHANICAL
MIXING THIS REGION SAW YESTERDAY. HOWEVER...SHOULD SEE MIXING UP TO
800-750MB...WHICH SUPPORTS DROPPING DEWPOINTS INTO THE LOW TEENS UP
NORTH. COMBINED WITH HIGHS MAINLY IN THE MID TO UPPER 60S AWAY FROM
LAKE MICHIGAN...HUMIDITIES SHOULD FALL INTO THE TEENS. ELEVATED
FIRE WEATHER CONDITIONS WILL THEREFORE CONTINUE TODAY.
TONIGHT...HIGH PRESSURE WILL REMAIN PRESENT ACROSS THE REGION.
SHOULD SEE THIN CIRRUS INVADE FROM THE SOUTH AHEAD OF A WEAK UPPER
LOW ACROSS THE PLAINS. OTHERWISE QUIET...WITH LOWS FALLING INTO THE
UPPER 30S TO LOW 40S.
WEDNESDAY...CIRRUS WILL CONTINUE TO INVADE THE REGION AND BECOME
THICKER...WHICH WILL LEAD TO FILTERED SUNSHINE. THE SURFACE HIGH
WILL MOVE TO THE EASTERN GREAT LAKES...WHICH WILL CAUSE EAST TO
SOUTHEAST WINDS TO BECOME RELATIVELY STRONGER THAN TODAYS EXPECTED
SPEEDS. THE AIRMASS WILL MOISTURE SOME...BUT STILL WENT WITH THE
LOWEST GUIDANCE...WHICH PLACES RH VALUES BETWEEN 15 TO 25 PERCENT.
NO REPRIEVE FROM ELEVATED FIRE WEATHER CONDITIONS AS A RESULT.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
ISSUED AT 308 AM CDT TUE APR 14 2015
CONTINUED WARM AND DRY CONDITIONS WILL CONTINUE INTO THE
WEEKEND...WITH ONLY A SMALL CHANCE OF SHOWERS FRIDAY INTO FRIDAY
EVENING. A MORE POTENT SYSTEM IS EXPECTED TO AFFECT THE REGION
EARLY NEXT WEEK.
FOR WEDNESDAY NIGHT...AN UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE
REGION. MODEL SOUNDINGS WERE BONE DRY...THUS REMOVED ANY MENTION OF
RAIN DESPITE STEEP MID LEVEL LAPSE RATES WITH THIS SYSTEM. ON
THURSDAY...MODEL SOUNDINGS STILL SHOW VERY DRY SOUNDINGS ALTHOUGH
NOT AS DRY AS TUESDAY AND WEDNESDAY SOUNDINGS. DID LOWER DEW
POINTS BY 3 TO 5 DEGREES MOST PLACES AS A STARTING POINT. WEAK
BOUNDARY EXPECTED TO MOVE ACROSS THE REGION ON FRIDAY...BRINGING
A SMALL CHANCE OF SHOWERS. MODELS DO SHOW MORE MOISTURE WITH THIS
FEATURE TO SUPPORT THE SMALL CHANCE OF SHOWERS.
HIGH PRESSURE WILL BUILD INTO THE REGION ON SATURDAY AND CONTINUE
INTO SUNDAY. VERY DRY CONDITIONS ARE EXPECTED AGAIN SATURDAY WITH
VERY LOW AFTERNOON RELATIVE HUMIDITY READINGS. ATTENTION THEN TURNS
TO UPPER LOW ACROSS THE CENTRAL UNITED STATES WILL INTERACT WITH
500MB TROUGH MOVING ACROSS SOUTHERN CANADA. THIS FEATURE SHOULD
ALLOW FOR LOW PRESSURE TO FORM AND BRING A CHANCE OF RAIN TO THE
AREA SUNDAY NIGHT AND MONDAY.
DID LOWER MIN TEMPERATURES WEDNESDAY NIGHT AND THURSDAY NIGHT...
WHILE RAISING MAX TEMPERATURES A DEGREE OR TWO ON MOST DAYS INTO
THE WEEKEND.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1230 PM CDT TUE APR 14 2015
EXCELLENT FLYING CONDITIONS EXPECTED OVER THE NEXT 24 HOURS AS
HI PRES MOVES THRU THE GREAT LAKES. WEST WINDS AT 5 TO 10 KTS THIS
AFTERNOON WL GO LGT/VRBL TNGT AND THEN BACK TO THE SE AT AROUND 10
KTS ON WED. VFR CONDITIONS TO PREVAIL WITH ONLY HI CLOUDS
STREAMING OVERHEAD.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......AK