Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/13/14
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
930 AM MST MON AUG 11 2014
.SYNOPSIS...
MOISTURE LEVELS HAVE INCREASED OVER THE PAST COUPLE DAYS AND WILL
CONTINUE TO SWING UPWARDS AND IMPROVE CHANCES FOR MONSOON RAIN
THROUGH THE MIDDLE OF THE WEEK. THE BEST CHANCE FOR RAIN WILL BE
TUESDAY AND WEDNESDAY AS A WEATHER DISTURBANCE MOVES NORTHWARD
THROUGH THE REGION. TEMPERATURES WILL REMAIN NEAR NORMAL LEVELS WITH
THE EXCEPTION OF TUESDAY AND WEDNESDAY WHEN MOSTLY CLOUDY SKIES
SHOULD KEEP TEMPERATURES SEVERAL DEGREES COOLER. DRIER CONDITIONS
EXPECTED BEGINNING THURSDAY AS WESTERLY FLOW PUSHES BACK OVER THE
REGION.
&&
.DISCUSSION...
A COMPLEX WEATHER SCENARIO IS SHAPING UP FOR THE NEXT COUPLE OF DAYS
WITH SOMEWHAT LIMITED MOISTURE TODAY...BUT WIDESPREAD AND VERY MOIST
CONDITIONS FOR TUESDAY INTO WEDNESDAY. MORNING RAOBS FOR PHOENIX AND
TUCSON BOTH SHOW FAIRLY MOIST AND UNSTABLE PROFILES WITH SLIGHTLY
DRIER CONDITIONS FOR PHOENIX. SOUNDINGS STILL SHOW AN INVERTED-V
TYPE STRUCTURE WITH NEAR SATURATED AND CONDITIONALLY UNSTABLE
MID-LEVELS. A CLOSED LOW CENTERED OFF THE COAST OF CENTRAL
CALIFORNIA CONTINUES TO BRING BROAD UPPER DIFFLUENCE ACROSS MUCH OF
SOUTHERN CALIFORNIA AND ARIZONA WITH A WEAK UPPER JET MAX SITUATED
FROM SAN DIEGO TO LAS VEGAS. THIS JET MAX IS CURRENTLY AIDING IN
ISOLATED SHOWER ACTIVITY ACROSS RIVERSIDE COUNTY...SO HAVE UPDATED
THE FORECAST POPS TO CHANCE IN THIS AREA THROUGH LATE MORNING.
ELSEWHERE...SKIES HAVE CLEARED OUT CONSIDERABLY SINCE EARLY MORNING
WHICH WILL ALLOW FOR A FAIRLY WARM DAY WITH HIGHS PEAKING A COUPLE
DEGREES ABOVE NORMAL.
THE FORECAST FOR THIS AFTERNOON AND EVENING REMAINS FAIRLY DIFFICULT
AS HI-RES MODELS ALL TELL A DIFFERENT STORY. WITH AMPLE MOISTURE IN
PLACE AND SOMEWHAT UNSTABLE ENVIRONMENT EXPECTED BY EARLY AFTERNOON
WE WILL SEE STORMS FIRE ALONG THE MOGOLLON RIM AND OVER SOUTHEAST
ARIZONA. THE STEERING FLOW IS MORE SOUTHEASTERLY TODAY VERSUS
YESTERDAY/S EASTERLY FLOW...SO WE SHOULD EXPECT BETTER CHANCES OF
ANY SOUTHEASTERN ARIZONA ACTIVITY VENTURING INTO THE LOWER DESERTS
BY LATE THIS AFTERNOON AND EVENING. IF A STRONG ENOUGH COLD POOL IS
GENERATED BEHIND ORGANIZED STORM OUTFLOWS...THERE IS A DECENT
LIKELIHOOD OF AT LEAST ISOLATED TO SCATTERED STORM DEVELOPMENT
ACROSS THE LOWER DESERTS THIS EVENING. FLOW ALOFT IS STILL FAIRLY
WEAK...SO THE DAMAGING WIND THREAT WILL BE MINIMAL...BUT CAN/T RULE
OUT A FEW STRONG WIND GUSTS.
FOR TONIGHT...INDICATIONS ARE POINTING TOWARD A CONTINUATION OF THE
SHOWER/STORM ACTIVITY WESTWARD THROUGH SOUTHERN ARIZONA...POSSIBLY
INTO SOUTHEAST CALIFORNIA LATE TONIGHT. THIS WILL ALL DEPEND ON THE
STRENGTH AND THE PROGRESSION OF STORM OUTFLOWS GENERATED FROM
EARLIER EVENING STORMS. PLAN TO MAKE ADJUSTMENTS TO INCREASE
TONIGHT/S POPS ACROSS SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA FOR
THE AFTERNOON FORECAST PACKAGE.
&&
.PREVIOUS DISCUSSION...
LATEST RAP STREAMLINE ANALYSIS INDICATES THAT THE MID-TROPOSPHERIC
HIGH IS POSITIONED ACROSS THE FOUR CORNERS...RESULTING IN A LIGHT
SOUTHEASTERLY FLOW ACROSS MUCH OF AZ. MEANWHILE...BLENDED TPW IS
AROUND 1.4 INCHES...WHICH IS SLIGHTLY ABOVE NORMAL FOR THIS TIME OF
YEAR. MODELS REMAIN IN GOOD AGREEMENT THAT TOTAL MOISTURE WILL BE ON
THE INCREASE THROUGH MIDWEEK AS THE RIDGE SHIFTS EASTWARD AND THE
FLOW BECOMES MORE SOUTHERLY.
FOR TODAY...CONSENSUS AMONG THE CAMS SUGGESTS THAT THUNDERSTORM
ACTIVITY WILL BE FOCUSED ALONG THE MOGOLLON RIM AND IN PIMA COUNTY.
STORMS AND ASSOCIATED OUTFLOW BOUNDARIES WILL PROPAGATE
NORTHWESTWARD THIS EVENING AND INSTABILITY WILL BE HIGH ENOUGH TO
SUPPORT AT LEAST ISOLATED ACTIVITY ACROSS PORTIONS OF THE PHOENIX
METRO AREA. GIVEN THE SOUTHEASTERLY TO NORTHWESTERLY
TRAJECTORY...AREAS OF BLOWING DUST WILL BE POSSIBLE AS WELL.
A MORE DISCERNIBLE INCREASE IN THUNDERSTORMS IS ANTICIPATED TUESDAY
AND POPS WERE RAISED SUBSTANTIALLY TO AROUND 60 PERCENT FOR THE
PHOENIX AREA AND UP TO 70 PERCENT ACROSS SOUTHERN GILA COUNTY.
MODELS REMAIN CONSISTENT SHOWING A WELL-DEFINED VORT MAX LIFTING
NORTHWARD OUT OF SONORA AND INTO SOUTHERN AZ...WHICH PLACES
SOUTH-CENTRAL AZ IN A FAVORABLE POSITION FOR CONVECTION. IN ADDITION
TO THE FORCED ASCENT AHEAD OF THIS SYSTEM...LOW-LEVEL THETA-E RIDGE
WILL BE PROMINENT ACROSS MUCH OF EASTERN AZ. ALONG WITH STRONG
DOWNBURST WINDS...STORMS WILL BE CAPABLE OF PRODUCING HEAVY RAIN AND
LOCALIZED FLOODING.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT
LIFTS NORTHEASTWARD. BELOW NORMAL TEMPERATURES ARE A GOOD BET GIVEN
THE ANOMALOUSLY HIGH MOISTURE AND RESIDUAL RAIN-COOLED AIR. BEST
CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER TERRAIN
NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY FLOW
SUGGESTS THE POSSIBILITY OF BACK BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 30 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND THROUGH THE
WEEKEND AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE OF
A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SCT-BKN MID LEVEL CLOUD DECKS AOA 12K FT...AND WINDS REMAINING
GENERALLY EASTERLY THROUGH THE DAY. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS FORMING OVER HIGHER TERRAIN NORTH/EAST/SOUTH OF
TERMINALS AFTER 19Z...A FEW STORMS AFFECTING TERMINALS AFTER 00Z
TUESDAY AS SOUTHEASTERLY STEERING FLOW WILL HELP MOVE STORMS INTO
LOWER DESERTS. EXPECT LOCAL CIGS DOWN TO 8KFT WITH STORMS THAT
APPROACH TERMINALS...ALONG WITH POTENTIAL FOR VISIBILITY REDUCTIONS
DOWN TO 1SM OR LESS IN AREAS OF BLOWING DUST AND 40-45KT OUTFLOW
WINDS. STORM ACTIVITY EXPECTED TO PERSIST UNTIL AROUND 06Z TUESDAY.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCT-BKN MID LEVEL CLOUDS GENERALLY AOA 12K PERSISTING THROUGHOUT THE
DAY...WITH ISOLATED THUNDERSTORMS POSSIBLE DURING THE LATE AFTERNOON
AND EVENING...FORMING EAST-SOUTHEAST OF KNYL/YUMA. NOT OUT OF THE
QUESTION FOR OUTFLOW WINDS FROM DISTANT STORMS TO CAUSE WIND SHIFTS
AT TERMINALS LATER THIS EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
FAIRLY GOOD CHANCES FOR SHOWERS AND STORMS WEDNESDAY WILL GENERALLY
ABATE LATER IN THE WEEK AS DRIER AIR FILTERS IN THE DISTRICT. THE
BEST CHANCES FOR ACCUMULATING WETTING RAINFALL WILL BE OVER GILA
COUNTY...WITH SOME CHANCE MOISTURE LINGERS OVER HIGHER TERRAIN INTO
THE END OF THE WEEK. WITH NEAR AVERAGE TEMPERATURES...AFTERNOON
RELATIVE HUMIDITY VALUES FALLING INTO A 25-40 PERCENT RANGE
WEDNESDAY WILL DRY TOWARDS A 10-25 PERCENT RANGE BY THE WEEKEND.
OVERNIGHT RECOVERY WILL BE GOOD TO EXCELLENT. OUTSIDE OF ANY GUSTY
THUNDERSTORM WINDS...TYPICAL LIGHTER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...KUHLMAN
PREVIOUS DISCUSSION...HIRSCH
AVIATION....MEYERS
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
545 AM MST MON AUG 11 2014
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
MOISTURE LEVELS WILL CONTINUE TO SWING UPWARDS AND IMPROVE CHANCES
FOR MONSOON RAIN THROUGH THE MIDDLE OF THE WEEK. THE BEST CHANCE FOR
RAIN WILL BE TUESDAY AND WEDNESDAY AS A SURGE OF MONSOONAL MOISTURE
MOVES THROUGH THE REGION. TEMPERATURES WILL REMAIN NEAR NORMAL
LEVELS WITH THE EXCEPTION OF TUESDAY AND WEDNESDAY WHEN MOSTLY
CLOUDY SKIES SHOULD KEEP TEMPERATURES SEVERAL DEGREES COOLER. DRIER
CONDITIONS EXPECTED BEGINNING THURSDAY AS WESTERLY FLOW PUSHES BACK
OVER THE REGION.
&&
.DISCUSSION...
LATEST RAP STREAMLINE ANALYSIS INDICATES THAT THE MID-TROPOSPHERIC
HIGH IS POSITIONED ACROSS THE FOUR CORNERS...RESULTING IN A LIGHT
SOUTHEASTERLY FLOW ACROSS MUCH OF AZ. MEANWHILE...BLENDED TPW IS
AROUND 1.4 INCHES...WHICH IS SLIGHTLY ABOVE NORMAL FOR THIS TIME OF
YEAR. MODELS REMAIN IN GOOD AGREEMENT THAT TOTAL MOISTURE WILL BE ON
THE INCREASE THROUGH MIDWEEK AS THE RIDGE SHIFTS EASTWARD AND THE
FLOW BECOMES MORE SOUTHERLY.
FOR TODAY...CONSENSUS AMONG THE CAMS SUGGESTS THAT THUNDERSTORM
ACTIVITY WILL BE FOCUSED ALONG THE MOGOLLON RIM AND IN PIMA COUNTY.
STORMS AND ASSOCIATED OUTFLOW BOUNDARIES WILL PROPAGATE
NORTHWESTWARD THIS EVENING AND INSTABILITY WILL BE HIGH ENOUGH TO
SUPPORT AT LEAST ISOLATED ACTIVITY ACROSS PORTIONS OF THE PHOENIX
METRO AREA. GIVEN THE SOUTHEASTERLY TO NORTHWESTERLY
TRAJECTORY...AREAS OF BLOWING DUST WILL BE POSSIBLE AS WELL.
A MORE DISCERNIBLE INCREASE IN THUNDERSTORMS IS ANTICIPATED TUESDAY
AND POPS WERE RAISED SUBSTANTIALLY TO AROUND 60 PERCENT FOR THE
PHOENIX AREA AND UP TO 70 PERCENT ACROSS SOUTHERN GILA COUNTY.
MODELS REMAIN CONSISTENT SHOWING A WELL-DEFINED VORT MAX LIFTING
NORTHWARD OUT OF SONORA AND INTO SOUTHERN AZ...WHICH PLACES
SOUTH-CENTRAL AZ IN A FAVORABLE POSITION FOR CONVECTION. IN ADDITION
TO THE FORCED ASCENT AHEAD OF THIS SYSTEM...LOW-LEVEL THETA-E RIDGE
WILL BE PROMINENT ACROSS MUCH OF EASTERN AZ. ALONG WITH STRONG
DOWNBURST WINDS...STORMS WILL BE CAPABLE OF PRODUCING HEAVY RAIN AND
LOCALIZED FLOODING.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT
LIFTS NORTHEASTWARD. BELOW NORMAL TEMPERATURES ARE A GOOD BET GIVEN
THE ANOMALOUSLY HIGH MOISTURE AND RESIDUAL RAIN-COOLED AIR. BEST
CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER TERRAIN
NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY FLOW
SUGGESTS THE POSSIBILITY OF BACK BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 30 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND THROUGH THE
WEEKEND AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE OF
A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SCT-BKN MID LEVEL CLOUD DECKS AOA 12K FT...AND WINDS REMAINING
GENERALLY EASTERLY THROUGH THE DAY. EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS FORMING OVER HIGHER TERRAIN NORTH/EAST/SOUTH OF
TERMINALS AFTER 19Z...A FEW STORMS AFFECTING TERMINALS AFTER 00Z
TUESDAY AS SOUTHEASTERLY STEERING FLOW WILL HELP MOVE STORMS INTO
LOWER DESERTS. EXPECT LOCAL CIGS DOWN TO 8KFT WITH STORMS THAT
APPROACH TERMINALS...ALONG WITH POTENTIAL FOR VISIBILITY REDUCTIONS
DOWN TO 1SM OR LESS IN AREAS OF BLOWING DUST AND 40-45KT OUTFLOW
WINDS. STORM ACTIVITY EXPECTED TO PERSIST UNTIL AROUND 06Z TUESDAY.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCT-BKN MID LEVEL CLOUDS GENERALLY AOA 12K PERSISTING THROUGHOUT THE
DAY...WITH ISOLATED THUNDERSTORMS POSSIBLE DURING THE LATE AFTERNOON
AND EVENING...FORMING EAST-SOUTHEAST OF KNYL/YUMA. NOT OUT OF THE
QUESTION FOR OUTFLOW WINDS FROM DISTANT STORMS TO CAUSE WIND SHIFTS
AT TERMINALS LATER THIS EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
FAIRLY GOOD CHANCES FOR SHOWERS AND STORMS WEDNESDAY WILL GENERALLY
ABATE LATER IN THE WEEK AS DRIER AIR FILTERS IN THE DISTRICT. THE
BEST CHANCES FOR ACCUMULATING WETTING RAINFALL WILL BE OVER GILA
COUNTY...WITH SOME CHANCE MOISTURE LINGERS OVER HIGHER TERRAIN INTO
THE END OF THE WEEK. WITH NEAR AVERAGE TEMPERATURES...AFTERNOON
RELATIVE HUMIDITY VALUES FALLING INTO A 25-40 PERCENT RANGE
WEDNESDAY WILL DRY TOWARDS A 10-25 PERCENT RANGE BY THE WEEKEND.
OVERNIGHT RECOVERY WILL BE GOOD TO EXCELLENT. OUTSIDE OF ANY GUSTY
THUNDERSTORM WINDS...TYPICAL LIGHTER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....MEYERS
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
340 AM MST MON AUG 11 2014
.SYNOPSIS...
MOISTURE LEVELS WILL CONTINUE TO SWING UPWARDS AND IMPROVE CHANCES
FOR MONSOON RAIN THROUGH THE MIDDLE OF THE WEEK. THE BEST CHANCE FOR
RAIN WILL BE TUESDAY AND WEDNESDAY AS A SURGE OF MONSOONAL MOISTURE
MOVES THROUGH THE REGION. TEMPERATURES WILL REMAIN NEAR NORMAL
LEVELS WITH THE EXCEPTION OF TUESDAY AND WEDNESDAY WHEN MOSTLY
CLOUDY SKIES SHOULD KEEP TEMPERATURES SEVERAL DEGREES COOLER. DRIER
CONDITIONS EXPECTED BEGINNING THURSDAY AS WESTERLY FLOW PUSHES BACK
OVER THE REGION.
&&
.DISCUSSION...
LATEST RAP STREAMLINE ANALYSIS INDICATES THAT THE MID-TROPOSPHERIC
HIGH IS POSITIONED ACROSS THE FOUR CORNERS...RESULTING IN A LIGHT
SOUTHEASTERLY FLOW ACROSS MUCH OF AZ. MEANWHILE...BLENDED TPW IS
AROUND 1.4 INCHES...WHICH IS SLIGHTLY ABOVE NORMAL FOR THIS TIME OF
YEAR. MODELS REMAIN IN GOOD AGREEMENT THAT TOTAL MOISTURE WILL BE ON
THE INCREASE THROUGH MIDWEEK AS THE RIDGE SHIFTS EASTWARD AND THE
FLOW BECOMES MORE SOUTHERLY.
FOR TODAY...CONSENSUS AMONG THE CAMS SUGGESTS THAT THUNDERSTORM
ACTIVITY WILL BE FOCUSED ALONG THE MOGOLLON RIM AND IN PIMA COUNTY.
STORMS AND ASSOCIATED OUTFLOW BOUNDARIES WILL PROPAGATE
NORTHWESTWARD THIS EVENING AND INSTABILITY WILL BE HIGH ENOUGH TO
SUPPORT AT LEAST ISOLATED ACTIVITY ACROSS PORTIONS OF THE PHOENIX
METRO AREA. GIVEN THE SOUTHEASTERLY TO NORTHWESTERLY
TRAJECTORY...AREAS OF BLOWING DUST WILL BE POSSIBLE AS WELL.
A MORE DISCERNIBLE INCREASE IN THUNDERSTORMS IS ANTICIPATED TUESDAY
AND POPS WERE RAISED SUBSTANTIALLY TO AROUND 60 PERCENT FOR THE
PHOENIX AREA AND UP TO 70 PERCENT ACROSS SOUTHERN GILA COUNTY.
MODELS REMAIN CONSISTENT SHOWING A WELL-DEFINED VORT MAX LIFTING
NORTHWARD OUT OF SONORA AND INTO SOUTHERN AZ...WHICH PLACES
SOUTH-CENTRAL AZ IN A FAVORABLE POSITION FOR CONVECTION. IN ADDITION
TO THE FORCED ASCENT AHEAD OF THIS SYSTEM...LOW-LEVEL THETA-E RIDGE
WILL BE PROMINENT ACROSS MUCH OF EASTERN AZ. ALONG WITH STRONG DOWNBURST
WINDS...STORMS WILL BE CAPABLE OF PRODUCING HEAVY RAIN AND LOCALIZED
FLOODING.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT
LIFTS NORTHEASTWARD. BELOW NORMAL TEMPERATURES ARE A GOOD BET GIVEN
THE ANOMALOUSLY HIGH MOISTURE AND RESIDUAL RAIN-COOLED AIR. BEST
CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER TERRAIN
NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY FLOW
SUGGESTS THE POSSIBILITY OF BACK BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 30 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND THROUGH THE
WEEKEND AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE OF
A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
CONSIDERABLE MID LEVEL DEBRIS CLOUDS NOW MOVING INTO THE CENTRAL
DESERTS WITH CIGS AOA 10K FT EXPECTED FOR THIS EVENING INTO MONDAY
MORNING. ALSO...GUSTY EASTERLY OUTFLOW WINDS HAVE MOVED INTO THE
DESERTS AND WINDS HAVE SHIFTED TO THE EAST AT ALL TAF SITES...WITH
GUSTS TO NEAR 30MPH SEEN AT KIWA. MAY SEE WINDS AOA 15KT AT TIMES AT
BOTH KPHX AND KSDL THRU 04-05Z THEN TAPERING OFF AND REMAINING
EASTERLY THRU DAY ON MONDAY. OUTFLOWS SPURRED ISOLATED STORMS NEAR
KIWA...BUT EXPECT THESE STORMS TO DISSIPATE AND LIKELY WILL NOT
AFFECT EITHER KPHX OR KSDL. AT LEAST...CONFIDENCE LOW ATTM THAT
STORMS WILL MOVE INTO KPHX.
MAY SEE A BETTER CHANCE FOR THUNDERSTORMS TO AFFECT THE GREATER
PHOENIX AREA TAF SITES MONDAY EVENING AS ATMOSPHERE BECOMES MORE
MOIST AND UNSTABLE...AND SELY STEERING WINDS ALOFT INCREASE.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
MOSTLY CLEAR SKIES WILL PREVAIL THROUGH AT LEAST THIS EVENING...WITH
A FAIRLY DECENT CHANCE OF CIGS AOA 10K FT SPREADING INTO THE REGION
BY SUNRISE MONDAY. ALTHOUGH MUCH LOWER CONFIDENCE...OUTFLOW WINDS
FROM SWRN ARIZONA MAY CAUSE WIND SHIFTS TO A SELY DIRECTION LATER
TONIGHT.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
FAIRLY GOOD CHANCES FOR SHOWERS AND STORMS WEDNESDAY WILL GENERALLY
ABATE LATER IN THE WEEK AS DRIER AIR FILTERS IN THE DISTRICT. THE
BEST CHANCES FOR ACCUMULATING WETTING RAINFALL WILL BE OVER GILA
COUNTY...WITH SOME CHANCE MOISTURE LINGERS OVER HIGHER TERRAIN INTO
THE END OF THE WEEK. WITH NEAR AVERAGE TEMPERATURES...AFTERNOON
RELATIVE HUMIDITY VALUES FALLING INTO A 25-40 PERCENT RANGE
WEDNESDAY WILL DRY TOWARDS A 10-25 PERCENT RANGE BY THE WEEKEND.
OVERNIGHT RECOVERY WILL BE GOOD TO EXCELLENT. OUTSIDE OF ANY GUSTY
THUNDERSTORM WINDS...TYPICAL LIGHT SUMMER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....MO/CB
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
949 PM MDT TUE AUG 12 2014
.UPDATE...
ISSUED AT 947 PM MDT TUE AUG 12 2014
SHOWERS DECAYING ON TIME...HIGH CLOUDS SPREADING SLOWLY
EASTWARD...A LITTLE SLOWER THAN EARLIER FORECAST. UPDATED FOR THE
CLOUD COVER AND TO REFRESH THE WORDING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 330 PM MDT TUE AUG 12 2014
FOR TONIGHT...OVERALL THE AIRMASS WILL REMAIN DRY AND SUBSIDENT
WITH THE UPPER LEVEL RIDGE OVERHEAD. THERE WILL BE ENOUGH MOISTURE
IN THE MOUNTAINS FOR A FEW EVENING THUNDERSTORMS...BUT COVERAGE
WILL BE LIMITED AND THE DURATION SHORT LIVED. THE HRRR SHOWS VERY
LIMITED DEVELOPMENT IN AND AROUND SUMMIT AND PARK COUNTIES BUT
DRY ELSEWHERE. ON WEDNESDAY...THE RIDGE IS PROGGED TO SHIFT TO THE
EAST WITH THE FLOW ALOFT BECOMING SOUTHWESTERLY. SUBTROPICAL
MOISTURE WILL INCREASE OVER WESTERN COLORADO AHEAD OF AN
APPROACHING UPPER LEVEL DISTURBANCE FM THE DESERT SOUTHWEST. THE
COVERAGE OF TSTMS WILL INCREASE IN THE MOUNTAINS AND PRECIPITABLE
WATER VALUES ARE PROGGED TO INCREASE AS WELL. BY LATE AFTN...SOME
OF TSTMS WILL START TO SPREAD INTO THE URBAN CORRIDOR. STORM
MOTIONS IN THE HIGH COUNTRY WEDNESDAY AFTN WILL BE SSW AROUND 15
KTS. ACROSS THE URBAN CORRIDOR AND ADJACENT PLAINS...SELY WINDS
WILL INCREASE IN THE AFTN...STG ENOUGH TO INDUCE A WEAK DENVER
CYCLONE. AS A RESULT...WL GO WITH A SLGT CHC OF TSTMS IN THE
AFTERNOON. CAPES AT KDEN IN THE 350-450MB RANGE BY 00Z THURSDAY
WITH PW VALUES CLOSE TO ONE INCH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 PM MDT TUE AUG 12 2014
THE NEXT WEEK WILL SEE CONTINUED RIDGING OVER THE SOUTHWESTERN
U.S. BUT WITH A SIGNIFICANT SURGE OF MONSOONAL MOISTURE ACROSS
COLORADO FOR THE LATTER HALF OF THIS WEEK. MOUNTAIN AREAS ARE
GOING TO SEE MOST OF THE PRECIPITATION FROM THE MONSOONAL
MOISTURE...BUT THE PLAINS WILL NOT BE IMMUNE TO THE RAINFALL. THE
WESTERN SLOPE SHOULD SEE THE ARRIVAL OF THE DEEPER MOISTURE BY
WEDNESDAY AFTERNOON...BUT COMPUTER MODELS ARE SHOWING A SHORT WAVE
TROUGH MOVING THROUGH THE UPPER RIDGE ON THURSDAY WHICH IS GOING
TO ORGANIZE AND SUSTAIN MOUNTAINS CONVECTION THROUGH THE DAY AND
ONTO THE PLAINS THURSDAY EVENING. ANOTHER ROUND OF AFTERNOON
SHOWERS IS EXPECTED ON FRIDAY AS ABUNDANT MONSOONAL MOISTURE
REMAINS OVER THE STATE AND UPPER LEVEL HEIGHTS BEGIN RISING. THE
REST OF THE WEEKEND WILL CONTINUE WITH MODERATE RIDGING ALOFT AND
A CONTINUED INTRUSION OF MONSOONAL MOISTURE UNDER THE RIDGE. FLOW
ALOFT WILL BE LIGHT TO MODERATE AND OUT OF THE WEST...MAKING IT
POSSIBLE FOR STORMS TO BE SLOW-MOVING AND CAPABLE OF PRODUCING
LOCALLY HEAVY RAINS. NO CHANGE IN THE UPPER LEVEL FLOW PATTERN
EXPECTED BEFORE THE MIDDLE OF NEXT WEEK. IN FACT...THE ECMWF IS
SHOWING ANOTHER MONSOONAL SURGE ARRIVING NEXT TUESDAY. UNTIL THEN
TEMPERATURES WILL BE AROUND SEASONAL NORMALS WITH A CHANCE OF
AFTERNOON SHOWERS EACH DAY.
&&
.AVIATION...(FOR THE TAFS THROUGH 06Z WEDNESDAY EVENING)
ISSUED AT 947 PM MDT TUE AUG 12 2014
VFR THROUGH WEDNESDAY. ISOLATED THUNDERSTORMS LATE WEDNESDAY
AFTERNOON MAINLY OVER THE MOUNTAINS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GIMMESTAD
SHORT TERM...COOPER
LONG TERM...DANKERS
AVIATION...GIMMESTAD
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
938 PM MDT TUE AUG 12 2014
.UPDATE...
ISSUED AT 931 PM MDT TUE AUG 12 2014
CONVECTIVE ACTIVITY HAS DIMINISHED THIS EVENING BUT ACTIVITY
ACROSS ARIZONA WILL BE LIFTING NORTH OVERNIGHT AND SHOULD GET INTO
OUR SOUTHERN ZONES AFTER 3 AM BASED ON LATEST HRRR PROJECTIONS.
WILL BE MAKING SOME TWEAKS TO POPS FOR THE REMAINDER OF THE NIGHT
TO TRY AND WORK IN THIS EXPECTED INCREASE IN ACTIVITY...ESPECIALLY
FOR SOUTHEAST UTAH. WEDNESDAY STILL LOOKING LIKE A FAIRLY WET DAY
ACROSS THE REGION...WITH LOCALIZED HEAVY RAINFALL AND POSSIBLE
FLASH FLOODING...THUS NO CHANGES TO THE CURRENT FLASH FLOOD
WATCHES THAT GO INTO EFFECT WEDNESDAY MORNING.
&&
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 343 PM MDT TUE AUG 12 2014
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPED THIS AFTERNOON ON
THE LEADING EDGE OF THE BETTER MOISTURE. STORMS WERE SLOW MOVING
WITH RADAR INDICATING HEAVY RAIN WITH A FEW OF THE STORMS...AND A
COUPLE SMALL STREAM FLOOD ADVISORIES HAVE BEEN ISSUED.
IT SHOULD ONLY GET WETTER WED. SATELLITE IMAGES SHOWED THE MAIN
MONSOONAL MOISTURE PLUME SQUARELY OVER UT THIS AFTERNOON WITH A
SHORTWAVE TROUGH MOVING NORTH INTO AZ FROM OLD MEXICO. THE DEEPER
MOISTURE REACHES SE UT WED MORNING AND WILL SLIDE OVER THE REST
OF OUR AREA DURING THE DAY...AS THE UPPER RIDGE OVER THE CENTRAL AND
SOUTHERN ROCKIES WEAKENS AND A PACIFIC LOW MOVES INTO WA/OR/NRN CA.
THE AZ SHORTWAVE ROTATES UP AND ACROSS ERN UT/WRN CO WED AND WED
EVENING. DESPITE EXTENSIVE CLOUD COVER THAT WILL INHIBIT SURFACE
HEATING...DYNAMIC LIFT FROM THIS DISTURBANCE AND A CONDITIONALLY
UNSTABLE ATMOSPHERE SHOULD LEAD TO SCATTERED TO NUMEROUS SHOWERS AND
SCATTERED THUNDERSTORMS WED AFTERNOON INTO WED NIGHT. A POCKET OF
30-40 KTS VERTICAL WIND SHEAR (0-6KM LAYER) ACCOMPANIES THE DISTURBANCE
FOR THE POSSIBILITY OF STRONGER AND LONGER-LIVED THUNDERSTORMS. WITH
PRECIPITABLE WATER VALUES OF 1 INCH OR MORE EXPECTED...HEAVY RAIN
WILL BE POSSIBLE. THE 12Z NAM/GFS AND THE 12Z HIGH-RES NMM/ARW MODELS
SHOWED BULLS EYES OF 1+ INCH OF RAINFALL.
DECIDED TO ISSUE A FLASH FLOOD WATCH FOR OUR AREA BEGINNING IN SE UT
AND PORTIONS OF SW CO WED MORNING...AND FOR THE REST OF THE AREA
STARTING AT NOON ON WED. EXTENDED THE WATCH THROUGH WED NIGHT.
WAS QUITE LIBERAL WITH THE AREAL COVERAGE AND VALID PERIOD GIVEN
DIFFERENT MODELS GAVE SOMEWHAT DIFFERENT TIMING/TRACK/QPF.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 343 PM MDT TUE AUG 12 2014
SHOWERS AND THUNDERSTORMS WILL CONTINUE THURSDAY WITH LOCALLY
HEAVY RAINFALL POSSIBLE.
UPPER LEVEL DISTURBANCE EXITS THE AREA ON THURSDAY. THE MODELS
ARE SLIGHTLY DIFFERENT WITH TIMING AND PLACEMENT OF THE UPPER
DISTURBANCE BUT ALL ARE INDICATING IT. PRECIPITABLE WATER VALUES
REMAIN HIGH DURING THE EARLY PART OF THE DAY DECREASING THROUGH
THE AFTERNOON INTO THE EVENING. INCREASED POPS THURSDAY MORNING
AND ALSO IN THE AFTERNOON WITH A TREND OF DECREASING COVERAGE IN
THE EVENING. DEPENDING ON THE DISTURBANCE TIMING...WIDE SPREAD
HEAVY RAIN AND FLOODING ARE POSSIBLE...BUT NOT CONFIDENT ENOUGH
RIGHT NOW TO EXTEND THE WATCH THIS FAR. HIGHER CONFIDENCE THAT
WILL HAVE SHOWERS AND THUNDERSTORMS WITH SOME STORMS PRODUCING
LOCALLY HEAVY RAINFALL. TEMPERATURES WILL BE CHECKED AND REMAIN
BELOW NORMAL VALUES DUE TO THE CLOUD COVER.
A DRIER AIRMASS MOVES INTO EASTERN UTAH AND WESTERN COLORADO
STARTING FRIDAY. WINDS ALOFT WILL BECOME WESTERLY AS THE UPPER LOW
MOVES FROM THE PAC NORTHWEST TO THE NORTHERN ROCKIES. WILL HAVE TO
WATCH THE PROGRESSION OF THE LOW. IF THE LOW SLOWS DOWN THE
DEEPER MOISTURE WILL NOT MOVE OUT AS QUICKLY ON FRIDAY. THE REST
OF THE WEEKEND LOOKS MAINLY DRY WITH ONLY LINGERING SHOWERS AND
THUNDERSTORMS FORMING OVER THE HIGHEST TERRAIN.
DRY AIR AND WESTERLY FLOW ALOFT CONTINUES INTO EARLY NEXT WEEK.
WITH THE DRIER AIR MAX TEMPERATURES WILL RETURN BACK TO NORMAL TO
SLIGHTLY ABOVE NORMAL THIS WEEKEND AND INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 931 PM MDT TUE AUG 12 2014
SHOWERS AND THUNDERSTORMS WILL BE INCREASING IN AREAL COVERAGE
AFTER 09Z THIS MORNING...WHILE THEY SPREAD NORTH AND EAST ACROSS
UTAH AND WESTERN COLORADO. HEAVY RAIN AND LOCAL MVFR TO IFR CIGS
AND VSBYS CAN BE EXPECTED AFTER 12Z WITH MOUNTAIN TOPS BECOMING
OBSCURED AS SHOWERS MOVE THROUGH. THIS ACTIVITY IS EXPECTED TO
PERSIST THROUGH WEDNESDAY EVENING.
&&
.HYDROLOGY...
ISSUED AT 931 PM MDT TUE AUG 12 2014
FLASH FLOOD WATCH REMAINS IN EFFECT WEDNESDAY AND WEDNESDAY NIGHT
AS DEEP SUBTROPICAL MOISTURE ASSOCIATED WITH A MONSOONAL SURGE
SLIDES OVER THE AREA. STORMS WILL HAVE SOME MOTION WEDNESDAY...BUT
DYNAMIC INPUT AND AMPLE MOISTURE WILL STILL ALLOW FOR THE
POSSIBILITY OF HEAVY RAIN FROM THUNDERSTORMS. RAINFALL OF 1 INCH
OR MORE WILL BE POSSIBLE. LOW LYING AREAS NEAR STEEP TERRAIN AND
WILDFIRE BURN SCARS...SLOT CANYONS AND SLICK ROCK AREAS...NORMALLY
DRY CREEKS...STREAMS AND ARROYOS WILL HAVE THE HIGHEST THREAT OF
FLASH FLOODING. THE HEAVY RAIN MAY PERSIST INTO THURSDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FLASH FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE
WEDNESDAY NIGHT FOR COZ001>014-017>019-022-023.
FLASH FLOOD WATCH FROM 6 AM MDT WEDNESDAY THROUGH LATE WEDNESDAY
NIGHT FOR COZ020-021.
UT...FLASH FLOOD WATCH FROM WEDNESDAY AFTERNOON THROUGH LATE
WEDNESDAY NIGHT FOR UTZ023>025-027.
FLASH FLOOD WATCH FROM 6 AM MDT WEDNESDAY THROUGH LATE WEDNESDAY
NIGHT FOR UTZ022-028-029.
&&
$$
UPDATE...JDC
SHORT TERM...JAD
LONG TERM...AS
AVIATION...JDC
HYDROLOGY...JAD/JDC
AREA FORECAST DISCUSSION
NWS TAUNTON MA
954 PM EDT TUE AUG 12 2014
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL BRING HEAVY RAIN ON WEDNESDAY.
AREAS OF URBAN AND LOCALIZED FLASH FLOODING ARE THE MAIN THREATS
WITH A LOW PROBABILITY FOR ISOLATED SEVERE WEATHER. ISOLATED SHOWERS
MAY DEVELOP ACROSS INLAND AREAS DURING THE DAYLIGHT HOURS LATE
THIS WEEK. EXPECT GENERALLY DRY CONDITIONS INTO EARLY THIS
WEEKEND...THEN ANOTHER SHOT FOR SHOWERS MOVES THROUGH THE REGION
SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
955 PM UPDATE...
TORRENTIAL RAINFALL/FLASH FLOODING BEGINNING TO COMMENCE OVER NJ
AS LOW LEVEL JET BEGINS TO FORM AND IS ALSO COLOCATED WITH AREA
OF BEST PRES FALLS AND ALONG WARM FRONTAL BOUNDARY. THIS HAS
INITIATED EMBEDDED CONVECTION WITHIN THIS AREA. MILLVILLE NJ IN
THE SOUTHERN PART OF THE STATE RECEIVED 3.39 INCHES OF RAINFALL
FROM 7 PM TO 9 PM! NONE OF THE HI RES MODEL GUID HANDLING THIS
PARTICULARLY WELL INCLUDING THE HRRR AND RAP13. THE GLOBAL GUID
/GFS AND ECMWF/ IS BETTER BUT IS TOO SLOW IN SPINNING UP
CONVECTION. THIS AREA OF EXCESSIVE RAINFALL IS TRACKING NNE TOWARD
NYC AND SHOULD ARRIVE INTO WESTERN NEW ENGLAND INCLUDING THE
GREATER HARTFORD/SPRINGFIELD AREA AROUND OR AFTER SUNRISE.
FARTHER EASTWARD MESO ANALYSIS CONTINUES TO INDICATE DEEP LAYER OF
DRY AIR ESPECIALLY AROUND 850 MB SOUTH OF NEW ENGLAND THAT STILL
HAS TO BE ADVECTED NORTHWARD. THIS IS ALSO EVIDENT ON THE 00Z OKX
UPPER AIR SOUNDING. THUS STEADY RAINS WILL NOT ARRIVE ACROSS MUCH
OF THE REGION UNTIL AFTER 12Z. HENCE HEAVIEST RAINFALL FOR MUCH OF
THE REGION ARRIVES LATE MORNING INTO EARLY AFTERNOON WED...
POSSIBLY LINGERING AND IMPACTING THE LATE DAY COMMUTE FOR THE
GREATER BOSTON AREA. PREVIOUS FORECAST CAPTURES THESE DETAILS
NICELY SO NO MAJOR CHANGES EXPECTED WITH THIS UPDATE. EARLIER
DISCUSSION BELOW.
=====================================================================
PREVIOUS DISCUSSION...
SPOTTY SHOWERS WILL TEND TO DISSIPATE AS THEY RUN INTO UPPER
LEVEL RIDGING AND DRIER AIRMASS ACROSS THE REGION.
WE SHOULD SEE THE RAIN SHOWERS RAPIDLY INCREASE IN AREAL COVERAGE
BETWEEN 07Z AND 08Z FROM SOUTHWEST TO NORTHEAST AS MID LEVEL DRY
AIR ERODES. LOW TEMPERATURES WILL BE IN THE 60S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
***FLASH FLOOD WATCH FOR THE POTENTIAL OF URBAN AND LOCALIZED FLASH
FLOODING IS THE MAIN CONCERN WEDNESDAY***
1) HEAVY RAIN - FLASH FLOOD THREAT
A LOW LEVEL JET 4 TO 5 STANDARD DEVIATIONS ABOVE NORMAL WILL
COMBINED WITH PWATS BETWEEN 1.75 AND 2 INCHES. THAT IS A CLASSIC
SETUP FOR A SUMMER TIME HEAVY RAIN AND LOCALIZED FLASH FLOOD EVENT.
THE MAIN UNCERTAINTY IS TRYING TO LOCATE WHERE THE HEAVIEST
RAIN/FLOOD THREAT WILL SET UP. GIVEN THAT WE HAVE SOUTH TO
SOUTHEAST FLOW...EXPECT TO SEE THE NORMALLY FAVORED UPSLOPE REGIONS
ALONG THE EAST SLOPES OF THE BERKSHIRES/WORCESTER HILLS AND
MONADNOCKS PERHAPS SEE LOCALLY HIGHER AMOUNTS. THERE MAY ALSO BE A
SECONDARY AREAS ACROSS EASTERN MA/RHODE ISLAND GIVEN A BETTER CHANCE
FOR EMBEDDED THUNDERSTORMS WITH HIGHER INSTABILITY.
OVERALL...EXPECT 1 TO 3 INCHES OF RAINFALL ACROSS MOST AREAS...WITH
LOCALIZED 4 OR 5 INCH AMOUNTS NOT OUT OF THE QUESTION. FORECASTING
QPF AMOUNTS IN THE SUMMER IS NO EASY TASK GIVEN CONVECTIVE FEEDBACK
ISSUES ETC. WE ARE NOT GOING TO BE ABLE TO PINPOINT EXACTLY WHERE
THE BEST CHANCE OF FLASH FLOODING MAY SETUP...OTHER THAN A GENERAL
OVERVIEW GIVEN IN THE PREVIOUS PARAGRAPH. THE MORE IMPORTANT THEME
IS THE POTENTIAL FOR SOME LOCALES TO RECEIVE 2+ INCHES OF RAIN IN
LESS THAN 1 HOUR...LEADING TO THE POTENTIAL FOR SOME URBAN AND
LOCALIZED FLASH FLOODING. THAT IS THE REASON A FLASH FLOOD WATCH IS
IN EFFECT FOR ALL BUT THE CAPE/ISLANDS ON WEDNESDAY.
2) SEVERE WEATHER THREAT
THE BEST SHEAR AND INSTABILITY DO NOT OVERLAP ON WEDNESDAY...SO
SEVERE WEATHER POTENTIAL APPEARS LIMITED. IN ADDITION...RAIN AND
CLOUD COVER WILL LIMIT THE AMOUNT OF INSTABILITY THAT IS ABLE TO
DEVELOP. HOWEVER...THERE IS STILL A LOW PROBABILITY FOR A FEW
STRONG TO SEVERE THUNDERSTORMS ACROSS NORTHERN CT/RHODE ISLAND AND
EASTERN MA. THIS WILL BE DEPENDENT ON WHETHER OR NOT WE CAN MUSTER
ENOUGH INSTABILITY AND HOW FAR NORTH THE SURFACE WARM FRONT MAKES IT
ACROSS THE REGION. ISOLATED STRONG WIND GUSTS WOULD BE THE MAIN
CONCERN. HOWEVER...GIVEN WE WILL HAVE A WARM FRONT TRYING TO LIFT
NORTH THERE IS A LOW PROBABILITY FOR A BRIEF TORNADO IN AN AREA OF
ENHANCED LOW LEVEL HELICITY.
AS A SIDE NOTE...THE LATEST SPC SREF SIGNIFICANT TORNADO PARAMETERS
DOES NOT INDICATE ANY PROBABILITIES IN OUR REGION...WHILE OUR AREA
WAS HIGHLIGHTED DURING THE REVERE DAY. NOW THAT CERTAINLY DOES NOT
MEAN WE CAN/T SEE A BRIEF TORNADO...BUT THE SETUP DOES NOT APPEAR AS
CONDUCIVE AS A FEW WEEKS AGO.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* SPOT SHOWERS POSSIBLE ACROSS INTERIOR BOTH THURSDAY AND FRIDAY
* COLD FRONT MOVES ACROSS SUNDAY INTO SUNDAY NIGHT
* BELOW NORMAL TEMPS LATE THIS WEEK WILL TREND CLOSER TO NORMAL
BY EARLY NEXT WEEK
OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE TO SIGNAL COOLER THAN NORMAL
TEMPERATURES ACROSS THE REGION WITH AMPLIFIED NORTHERN STREAM
PATTERN IN PLACE ACROSS NORTH AMERICA. H5 CUTOFF LOW PRES/COLD POOL
SETS UP ACROSS NORTHERN NEW ENGLAND INTO QUEBEC LATE THIS WEEK INTO
THE WEEKEND. MODELS AND ENSEMBLES START TO FLATTEN OUT THIS PATTERN
LATER THIS WEEKEND...WITH UPPER LEVEL WINDS BECOMING MORE NW. WILL
START TO SEE CHANGES IN THE TIMING OF SYSTEMS ACROSS THE NORTHERN
STREAM FROM ABOUT SUNDAY ONWARD...WHICH THE LONGER RANGE OPERATIONAL
MODELS ARE NOT HANDLING WELL. GFS/EC ENSEMBLES TENDING TO LEAN
TOWARD THE LAST COUPLE OF EC OP SOLUTIONS...WHICH IS ON THE SLOWER
SIDE OF THE FORECAST GUIDANCE IN KEEPING A MORE AMPLIFIED UPPER
LEVEL PATTERN IN PLACE.
LEANED TOWARD A BLEND OF AVAILABLE GUIDANCE INTO THIS WEEKEND...
THEN TRENDED TOWARD THE GFS/EC ENSEMBLES WHICH WERE PRETTY CLOSE TO
WPC GUIDANCE.
DETAILS...
WEDNESDAY NIGHT...
EXPECT FRONTAL SYSTEM/LOW PRES TO PUSH NE INTO MAINE...WHICH WILL
PUSH THE PRECIP WITH IT. WILL SEE LEFTOVER SHOWERS/ISOLD TSTMS
UNTIL AROUND MIDNIGHT...WITH THE BEST CHANCE ACROSS CENTRAL AND
EASTERN AREAS. PRECIP WILL END FROM W-E AFTER MIDNIGHT...WITH
DRIER AND COOLER AIR WORKING IN. OVERNIGHT LOWS WILL FALL TO THE
LOWER-MID 50S ACROSS SW NH/N CENTRAL AND W MA...MAINLY OVER THE
HIGHER TERRAIN... RANGING TO THE MID 60S ACROSS THE MID AND OUTER
CAPE AND THE ISLANDS. DEWPTS WILL ALSO FALL BACK WELL
INLAND...DOWN TO THE MID 50S TOWARD DAYBREAK.
THURSDAY AND FRIDAY...
CUTOFF UPPER LOW WILL SLOWLY SPIN ACROSS NORTHERN NEW ENGLAND
INTO QUEBEC DURING THIS TIMEFRAME. WHILE SOME SURFACE SUBSIDENCE
WILL BE IN PLACE ON LIGHT W-NW WINDS...STILL CAN NOT RULE OUT A
FEW SPOTTY DIURNAL SHOWERS EACH DAY WITH THE COLD POOL ALOFT. DOES
LOOK LIKE BEST CHANCE FOR ANY ACTION WILL BE DURING
FRIDAY...THOUGH...AS THERE APPEARS TO BE A WEAK SHORT WAVE
ROTATING AROUND THE BASE OF THE UPPER TROUGH. ONLY CARRIED SLIGHT
CHANCE POPS MAINLY NEAR AND N OF ROUTE 2. DID NOT MENTION THUNDER
AT THIS TIME...BUT CAN NOT TOTALLY RULE OUT SOME LOW TOPPED
CONVECTION.
HOWEVER...DO EXPECT COMFORTABLE CONDITIONS AS DEWPTS CONTINUE TO
FALL BACK...MAINLY IN THE 50S THOUGH SOME INLAND SPOTS ACROSS S NH/N
CENTRAL AND W MA COULD SEE DEWPTS DOWN IN THE MID-UPPER 40S THU
NIGHT. DAYTIME HIGHS BOTH DAYS WILL MAINLY BE IN THE 70S...THOUGH
SOME SPOTS ON FRIDAY MAY NOT MAKE IT TO 70 ACROSS THE HIGHER TERRAIN
OF SW NH...RUNNING AROUND 5 DEGREES BELOW SEASONAL NORMS.
SATURDAY...
UPPER LEVEL CUTOFF/COLD POOL STUBBORN TO MOVE...BUT LOOKS LIKE IT
FINALLY BEGINS TO SHIFT E TOWARD THE MARITIMES LATER SAT/SAT
NIGHT...AT LEAST ON THIS MODEL SUITE. HAVE RUN WITH DRY CONDITIONS
DURING THE DAY WITH HIGHS AGAIN IN THE 70S REGIONWIDE. AS NW FLOW
TAKES OVER...MIGHT SEE A FEW SHOWERS BEGIN TO APPROACH AS WEAK
SHORT WAVE/SURFACE FRONT MOVES SE LATE SAT NIGHT. ONLY CARRIED
SLIGHT CHANCE POPS AFTER 06Z OVER SW NH.
SUNDAY...
COLD FRONT IN THE UPPER FLOW MOVES ACROSS THE REGION...BUT TIMING
IN QUESTION AS GFS AND EC AT ODDS ON HOW THE UPPER LEVEL FLOW
BREAKS DOWN ACROSS THE EASTERN U.S. THE SURFACE FEATURE DOES TEND
TO WEAKEN AS THE UPPER LEVEL SYSTEM PUSHES THROUGH. CURRENT TIMING
SUGGESTS BEST SHOT WILL OCCUR DURING MAX HEATING OF THE DAY...SO
HAVE CARRIED SCT SHOWERS. ONLY MARGINAL INSTABILITY AT BEST AS THE
FRONT CROSSES...THOUGH NOTING SOME ENHANCEMENT LATER IN THE DAY
INTO EARLY SUN NIGHT AS THE FRONT APPROACHES THE S COAST. HAVE NOT
MENTIONED THUNDER IN THE FORECAST...FOR NOW. HAVE ENDED PRECIP BY
AROUND MIDNIGHT...BUT AGAIN TIMING IN QUESTION.
MONDAY-TUESDAY...
QUITE A DIFFERENCE IN OP MODEL SOLUTIONS DURING THIS TIMEFRAME...
ALL IN THE WAY THEY HANDLE THE BREAKDOWN /OR LACK THEREOF/ OF THE
UPPER LEVEL PATTERN AND MOVEMENT OF A SHORT WAVE IN THE FLATTER H5
PATTERN AROUND THE LATE MONDAY/TUESDAY TIMEFRAME. LEANED CLOSER TO
THE EC MODEL...WHICH WAS IN FAIRLY GOOD AGREEMENT WITH THE GFS/EC
ENSEMBLES. KEPT MAINLY DRY FORECAST GOING...THOUGH DID KEEP IN
SLIGHT CHANCE POPS OVER CENTRAL AND NORTHERN AREAS DURING MONDAY
FOR NOW. TEMPS LOOK TO BE CLOSE TO SEASONAL NORMS DURING THIS
TIMEFRAME.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...TONIGHT THROUGH WEDNESDAY...
TONIGHT...MODERATE CONFIDENCE. MVFR-IFR CONDITIONS WILL MOVE
ACROSS THE REGION FROM WEST TO EAST...BUT THERE IS UNCERTAINTY ON
THE TIMING. COULD SEE LOWER CIGS INTO S COASTAL AREAS BY 03Z-05Z.
A FEW SPOT SHOWERS ARE POSSIBLE THIS EVENING...BUT THE BULK OF
THE RAIN WILL MOVE IN FROM WEST TO EAST BETWEEN 06Z AND 12Z.
WEDNESDAY...MODERATE TO HIGH CONFIDENCE. WIDESPREAD LOW END MVFR TO
IFR CIGS/VSBYS. BANDS OF HEAVY RAIN SHOWERS EXPECTED ALONG WITH
ISOLATED THUNDERSTORMS. LLWS WILL ALSO BE A CONCERN.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF THIS EVENING WITH MODERATE
CONFIDENCE AFTER MIDNIGHT.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF.
OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY...
WEDNESDAY NIGHT...HIGH CONFIDENCE. MVFR/IFR CONDITIONS IN +RA
ACROSS EASTERN MA. IMPROVING TREND FROM WEST TO EAST THROUGH THE
OVERNIGHT HOURS.
THURSDAY THROUGH SATURDAY...HIGH CONFIDENCE. VFR. LOW CHANCE FOR SEA
BREEZES ALONG THE COASTLINES MAINLY FRIDAY/SATURDAY. MAY SEE LOCAL
MVFR CONDITIONS IN SCT SHOWERS ACROSS S NH/N CENTRAL-W MA AFTER
MIDNIGHT SAT NIGHT.
SUNDAY...MODERATE CONFIDENCE. GENERALLY LOW END VFR CONDITIONS.
AREAS OF MVFR CIGS/VSBYS IN SCT SHOWERS DURING THE DAY...WHICH
SHOULD SLOWLY IMPROVE FROM W-E SUN NIGHT.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...TONIGHT AND WEDNESDAY...
TONIGHT AND WEDNESDAY...MODERATE TO HIGH CONFIDENCE. AN ANOMALOUS
SHORTWAVE FOR AUGUST STANDARDS WILL MOVE EAST FROM THE GREAT LAKES.
THIS WILL INDUCE A STRONG SOUTH TO SOUTHEAST LOW LEVEL JET LATE
TONIGHT AND WEDNESDAY. THE RESULT WILL BE SOUTHEAST SCA WIND GUSTS
OF 25 TO 30 KNOTS AND BUILDING SEAS. SCA HEADLINES ARE POSTED FOR
SOME AREAS BEGINNING LATE TONIGHT AND ALL LOCATIONS BY WEDNESDAY.
IN ADDITION...HEAVY RAIN/ISOLATED THUNDERSTORMS AND AREAS OF FOG
WILL REDUCE VISIBILITIES FOR MARINERS. ALSO...THERE REMAINS A LOW
PROBABILITY FOR A WATERSPOUT GIVEN HIGH SHEAR ON A NORTHWARD MOVING
WARM FRONT.
OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY...
WEDNESDAY NIGHT AND THURSDAY...SMALL CRAFTS IN PLACE THROUGH WED
NIGHT ON MOST WATERS BUT WINDS/SEAS WILL DIMINISH OVERNIGHT. MAY
NEED TO EXTEND INTO THU FOR THE OUTER WATERS AS SEAS MAY LINGER AT
AROUND 5-6 FT EARLY BEFORE SUBSIDING.
FRIDAY AND SATURDAY...EXPECT WINDS AND SEAS BELOW SMALL CRAFT
CRITERIA.
SUNDAY...COLD FRONT WILL APPROACH THE WATERS LATE SUN/SUN NIGHT BUT
EXPECT CONDITIONS TO REMAIN BELOW SMALL CRAFT LEVELS.
&&
.TIDES/COASTAL FLOODING...
A COASTAL FLOOD ADVISORY WAS ISSUED FOR THE EAST AND SOUTH COASTS
FOR THE WEDNESDAY HIGH TIDE CYCLE...THAT RUNS FROM LATE MORNING INTO
MID AFTERNOON. EAST TO SOUTHEAST FLOW AHEAD OF A WARM FRONT WILL
ALLOW FOR A 0.5 TO 1 FOOT STORM SURGE. THIS MAY BE ENOUGH TO
PRODUCE SOME POCKETS OF SPLASH OVER OR VERY MINOR COASTAL FLOODING
DURING THE WEDNESDAY NIGH TIDE. THE HEAVY RAIN MAY EXACERBATE THE
PROBLEM A BIT...SLOWING DOWN THE DRAINAGE AFTER THE HIGH TIDE.
OVERALL...THIS WILL BE A NUISANCE EVENT AT WORST BUT A FEW OF THE
MOST VULNERABLE SHORE ROADS COULD BE IMPACTED WITHIN AN HOUR OR TWO
OF HIGH TIDE.
&&
.EQUIPMENT...
THE KBOX RADAR IS CURRENTLY BACK IN SERVICE...BUT THE PART NEEDED TO
PERMANENTLY FIX THE RADAR WILL NOT BE IN UNTIL WEDNESDAY.
THEREFORE...ITS POSSIBLE THAT THE RADAR MAY GO DOWN AGAIN SO USE
WITH CAUTION.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH FROM 6 AM EDT WEDNESDAY THROUGH WEDNESDAY
EVENING FOR CTZ002>004.
MA...FLASH FLOOD WATCH FROM 6 AM EDT WEDNESDAY THROUGH WEDNESDAY
EVENING FOR MAZ002>021-026.
COASTAL FLOOD ADVISORY FROM 9 AM TO 4 PM EDT WEDNESDAY FOR
MAZ007-015-016-019>022-024.
NH...FLASH FLOOD WATCH FROM 6 AM EDT WEDNESDAY THROUGH WEDNESDAY
EVENING FOR NHZ011-012-015.
RI...FLASH FLOOD WATCH FROM 6 AM EDT WEDNESDAY THROUGH WEDNESDAY
EVENING FOR RIZ001>007.
COASTAL FLOOD ADVISORY FROM 9 AM TO 4 PM EDT WEDNESDAY FOR
RIZ006-007.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM WEDNESDAY TO MIDNIGHT EDT
WEDNESDAY NIGHT FOR ANZ231>234.
SMALL CRAFT ADVISORY FROM 10 AM TO 6 PM EDT WEDNESDAY FOR
ANZ230.
SMALL CRAFT ADVISORY FROM 2 AM TO 6 PM EDT WEDNESDAY FOR
ANZ236.
SMALL CRAFT ADVISORY FROM 2 AM WEDNESDAY TO 6 AM EDT THURSDAY
FOR ANZ235-237.
SMALL CRAFT ADVISORY FROM 6 AM WEDNESDAY TO 6 AM EDT THURSDAY
FOR ANZ250-251.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...FRANK/EVT
NEAR TERM...FRANK/NOCERA/EVT
SHORT TERM...FRANK
LONG TERM...EVT
AVIATION...FRANK/EVT
MARINE...FRANK/EVT
TIDES/COASTAL FLOODING...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS ALBANY NY
801 PM EDT TUE AUG 12 2014
.SYNOPSIS...
THE COMBINATION OF A LOW PRESSURE SYSTEM LOCATED NORTH OF THE GREAT
LAKES...AND A SECONDARY LOW DEVELOPING ACROSS THE NORTHERN MID
ATLANTIC STATES WILL BRING A WIDESPREAD SOAKING RAINFALL TO THE
REGION OVERNIGHT INTO EARLY WEDNESDAY. RAIN WILL TAPER TO SHOWERS
AND THUNDERSTORMS BY WEDNESDAY AFTERNOON. THE LOWS WILL THEN MOVE
INTO NORTHERN NEW ENGLAND BY LATE WEDNESDAY...BUT AN UPPER LEVEL LOW
WILL THEN LINGER ACROSS SOUTHEAST CANADA...KEEPING SOMEWHAT COOL AND
UNSETTLED CONDITIONS THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 730 PM EDT...WIDELY SCATTERED SHOWERS WERE ACROSS THE REGION
AS WINDS WERE OCCASIONALLY GUSTING TO NEAR 20KTS. THE VWP SUGGESTS
WINDS HAVE NOT INCREASED THE PAST COUPLE HOURS...EVEN THOUGH THE
UPSTREAM DRY SLOT WAS APPROACHING. PER THE LATEST GUIDANCE...SEEMS
WE WILL BE IN THE VOID OF MODERATE TO HEAVY PRECIP THIS EVENING
AND IF THE HRRR REMAINS ON COURSE...LITTLE IN THE WAY OF RAINFALL
ACCUMULATION IS EXPECTED THIS EVENING.
HOWEVER...THE LOW LEVEL JET IS FORECAST TO INCREASE AS WE WILL
CONTINUE TO WATCH TRENDS CLOSELY FOR THE BERKS AND TACONICS.
MEANWHILE...CONVECTIVE LINE UPSTREAM WILL BECOME BETTER ORGANIZED
AS UPPER SUPPORT AND SURFACE CONVERGENCE INCREASES.
THROUGH AT LEAST MIDNIGHT...MOST OF THE RAIN ACROSS THE REGION
SHOULD REMAIN INTERMITTENT...AND GENERALLY LIGHT IN INTENSITY. SO
WE WILL LOWER POPS A BIT THROUGH THIS EVENING.
AFTER MIDNIGHT...THE COMBINATION OF STRONGER ISENTROPIC LIFT...AND
OVERALL INTENSIFYING UPPER LEVEL DYNAMICS SHOULD ALLOW A STEADIER
RAIN...WITH EMBEDDED SHALLOW CONVECTIVE ELEMENTS...TO GRADUALLY
EXPAND EAST AND NORTH. HIGH RESOLUTION MODELS...ESP THE RAP13/HRRR
SUGGEST THAT THE MOST INTENSE RAINFALL MAY HOLD OFF UNTIL AFTER 4
AM...ESP FROM ALBANY N AND E. THESE MODELS ALSO SUGGEST THAT A
NARROW COLD FRONTAL RAINBAND TYPE FEATURE MAY DEVELOP AND MOVE
NORTHEAST ACROSS THE REGION...REACHING WESTERN AREAS BETWEEN 4-6
AM...THE HUDSON VALLEY REGION AROUND 6 AM...AND AREAS ACROSS
WESTERN NEW ENGLAND GENERALLY AFTER 6 AM. RAINFALL RATES WITHIN
THIS FEATURE WILL LIKELY BE IN THE 1-2 INCH RANGE. IN AREAS WHERE
THIS FEATURE SLOWS ITS FORWARD MOVEMENT...FLASH FLOODING POTENTIAL
WILL EXIST...HENCE THE CONTINUATION OF THE FLASH FLOOD WATCH FOR
MOST AREAS OUTSIDE OF THE FAR WESTERN AND SOUTHERN
ADIRONDACKS...AND ACROSS THE LAKE GEORGE/SARATOGA REGION.
WINDS WILL INCREASE LATER TONIGHT...WITH SOUTHEAST WINDS
OCCASIONALLY GUSTING INTO THE 25-35 MPH RANGE...PERHAPS EVEN
STRONGER ACROSS SOME AREAS WITHIN THE IMMEDIATE HUDSON RIVER
VALLEY...THE CENTRAL/NORTHERN TACONICS...AND ACROSS SW VT/WESTERN
MA...WHERE ENHANCED CHANNELED FLOW MAY ALLOW FOR WIND GUSTS TO
REACH 35-45 MPH AT TIMES.
TEMPS SHOULD NOT FALL TOO MUCH...GENERALLY INTO THE LOWER/MID 60S
IN MOST AREAS...AND POSSIBLY ONLY INTO THE UPPER 60S ACROSS
PORTIONS OF THE MID HUDSON VALLEY AND NW CT.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
WEDNESDAY...THE AFOREMENTIONED NARROW COLD FRONTAL RAINBAND
FEATURE SHOULD PROPAGATE NORTHEAST ACROSS THE REGION THROUGH THE
MID MORNING HOURS. THE BEST POTENTIAL FOR ITS HEAVY RAINFALL
IMPACTS...AND GUSTY WINDS WILL BE PARTICULARLY FROM THE HUDSON
RIVER AND POINTS EAST. AFTER THIS FEATURE PASSES...THE SYSTEM/S
OCCLUDED FRONTAL BOUNDARY WILL SLOWLY ADVANCE EAST ACROSS THE
REGION IN THE AFTERNOON. ADDITIONAL SHOWERS AND PERHAPS SOME
THUNDERSTORMS WILL DEVELOP ALONG OR JUST AHEAD OF THIS
BOUNDARY...POSSIBLY ENHANCING HEAVY RAINFALL. IN ADDITION...WILL
HAVE TO WATCH FOR ANY BREAKS IN THE CLOUDS THAT DEVELOP AHEAD OF
THIS BOUNDARY. IT APPEARS THAT THE BEST POTENTIAL FOR ANY LIMITED
SUNSHINE TO DEVELOP WILL BE PRIMARILY SOUTH OF INTERSTATE 90...AS
LOW CLOUDS AND RAIN COOLED LOW LEVEL AIR MAY REMAIN FAIRLY
ENTRENCHED FURTHER NORTH. IN AREAS WHERE SOME SUN CAN
DEVELOP...SOMEWHAT DEEPER CONVECTIVE ELEMENTS COULD DEVELOP...AND
POSSIBLY FORM INTO A LINE...AS THE COMBINATION OF INSTABILITY FROM
COOLING MID LEVELS...AND ADDITIONAL FORCING MOVE ACROSS THE
REGION. SHOULD THIS OCCUR...CAN NOT RULE OUT SOME STRONG/ISOLATED
SEVERE THUNDERSTORMS WITH HAIL/GUSTY WINDS. TEMPS SHOULD REACH THE
LOWER/MID 70S...ASSUMING THAT SOME SUN CAN OCCUR EITHER AHEAD
OF...OR BEHIND THE OCCLUDED FRONTAL BOUNDARY. HOWEVER...IN AREAS
WHERE LOW CLOUDS HANG TOUGH...SUCH AS ACROSS THE LAKE GEORGE
REGION AND SOUTHERN ADIRONDACKS...SOME AREAS MAY ONLY REACH THE
UPPER 60S.
WED NT-THU NT...AS THE MAIN OCCLUDED FRONT MOVES PAST...THE THREAT
FOR SHOWERS WILL GRADUALLY DIMINISH WED EVE FROM SW TO NE.
HOWEVER...THE COMBINATION OF COOL AIR ALOFT...CYCLONIC FLOW...AND
WEAK PIECES OF ENERGY POTENTIALLY ROTATING AROUND THE SOUTHERN
PERIPHERY OF THE CLOSED LOW NORTH OF THE GREAT LAKES SHOULD
PROMOTE THE CHANCES FOR SHOWERS ACROSS THE SOUTHERN
ADIRONDACKS...AND OCCASIONALLY INTO THE MOHAWK VALLEY AND LAKE
GEORGE/SARATOGA REGIONS AND SOUTHERN VT...WITH MORE LIMITED
ACTIVITY EXPECTED FURTHER SOUTH AND EAST WHERE MORE LOW LEVEL
DOWNSLOPING AND SLIGHTLY WARMER TEMPS ALOFT WILL REMAIN. SO...WILL
KEEP CHC POPS FOR NORTHERN AREAS...WITH SLIGHT CHC POPS OR LESS
FURTHER SOUTH. TEMPS WILL FALL INTO THE 50S AT NIGHT...WITH SOME
40S POSSIBLE ACROSS HIGHER ELEVATIONS. THU MAX TEMPS SHOULD REACH
70-75 IN MOST VALLEYS...BUT ONLY REACH THE 60S ACROSS MOST HIGHER
ELEVATIONS...WITH SOME OF THE HIGHEST PEAKS OF THE SOUTHERN
ADIRONDACKS POSSIBLY ONLY REACHING THE 50S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
WE BEGIN THE LONG TERM PERIOD WITH OUR CLOSED UPPER LOW OVER THE
EASTERN GREAT LAKES REGION/ST LAWRENCE VALLEY. CYCLONIC MOIST AND
COOL FLOW WILL LIKELY KEEP CLOUDS AND THE CHANCE FOR SHOWERS WITH
EVEN SOME LAKE EFFECT/ENHANCED SHOWERS DOWNWIND OF LAKE ONTARIO AS
H850 TEMPS ARE FORECAST TO DROP BACK INTO THE SINGLE DIGITS CELSIUS.
THIS UPPER LOW WILL EVENTUALLY LIFT NORTH AND EAST OF THE REGION
HEADING INTO THE WEEKEND. HOWEVER...GLOBAL MODELS CONTINUE TO
INSIST ANOTHER PV ANOMALY EMBEDDED WITHIN THE CYCLONIC FLOW REGIME
MAY BRING MORE CLOUDS AND THE CHANCE FOR SHOWERS LATER SATURDAY INTO
SUNDAY. THE RECENT TRENDS SUPPORT A LITTLE FURTHER SOUTH TRACK WITH
THIS WAVE /CLOSER TO I80/ WHICH WOULD POINT TOWARD A GRADUATED POP
FORECAST WITH LOWER VALUES NORTH OF I90 AND HIGHER VALUES TOWARD
I88/I84 CORRIDORS.
TEMPERATURES FRIDAY THROUGH SUNDAY ARE EXPECTED TO AVERAGE BELOW
NORMAL DUE TO THE CLOUD COVER AND THE CHANCE FOR SHOWERS.
THERE IS GROWING CONSENSUS THAT THIS WAVE WILL BE THE LAST IN A
SERIES OF WAVES WITHIN THIS CYCLONIC FLOW AND RISING
HEIGHTS/SUBSIDENCE SHOULD UNFOLD ACROSS THE REGION FOR EARLY NEXT
WEEK. THIS WOULD RETURN BACK THE SUNSHINE AND NEAR SEASONABLE
TEMPERATURES. HOWEVER...NEXT WAVE THAT EVOLVES OVER THE PLAINS
STATES APPROACHED THE OHIO VALLEY LATE MONDAY/MONDAY-NIGHT.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL DETERIORATE TO MVFR TOWARD LATE THIS
EVENING...THEN INTO MVFR/IFR CONDITIONS OVERNIGHT EXTENDING INTO
WEDNESDAY MORNING.
CLOUDS WILL CONTINUE TO THICKEN TONIGHT AS CEILINGS GRADUALLY
LOWERING AS OCCASIONAL LIGHT RAIN AND SPRINKLES AFFECT THE TAF
SITES. THE RAIN SHOULD BE LIGHT ENOUGH SO THAT IT CAN BE
INDICATED AS 6SM -RA OR VCSH...KEEPING CONDITIONS VFR. MORE
WIDESPREAD MVFR CONDITIONS WILL BE POSSIBLE BY MIDNIGHT... ESPECIALLY
WHERE ANY PERSISTENT SHOWERS OCCUR. STEADIER RAIN AND EVEN SOME
EMBEDDED THUNDER WILL MOVE IN OVERNIGHT...WITH ASSOCIATED MVFR/IFR
CONDITIONS. THE RAIN WILL BE HEAVY AT TIMES. AFTER ABOUT 13Z
TOMORROW MORNING...THE INTENSITY AND COVERAGE OF THE RAIN SHOULD
GRADUALLY DECREASE BUT VISIBILITIES SHOULD STILL BE MVFR WITH
CEILINGS BORDERING IFR/MVFR.
WINDS WILL BE FROM A SOUTH-SOUTHEAST DIRECTION TO AROUND 9-13 KT
THIS AFTERNOON THEN DIMINISHING THIS EVENING AND OVERNIGHT TO 10 KT
OR LESS. WINDS WILL WEAKEN AFTER SUNRISE TO 6 KT OR LESS AND SHIFT
TO THE EAST AND SOUTHEAST.
OUTLOOK...
WEDNESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
THURSDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
THE COMBINATION OF A LOW PRESSURE SYSTEM LOCATED NORTH OF THE GREAT
LAKES...AND A SECONDARY LOW DEVELOPING ACROSS THE NORTHERN MID
ATLANTIC STATES WILL BRING A WIDESPREAD SOAKING RAINFALL TO THE
REGION OVERNIGHT INTO EARLY WEDNESDAY. RAIN WILL TAPER TO SHOWERS
AND THUNDERSTORMS BY WEDNESDAY AFTERNOON. THE LOWS WILL THEN MOVE
INTO NORTHERN NEW ENGLAND BY LATE WEDNESDAY...BUT AN UPPER LEVEL LOW
WILL THEN LINGER ACROSS SOUTHEAST CANADA...KEEPING SOMEWHAT COOL AND
UNSETTLED CONDITIONS THROUGH THE END OF THE WEEK.
&&
.HYDROLOGY...
A LOW PRESSURE SYSTEM WILL BRING SHOWERS TO THE REGION
THIS EVENING...WITH A WIDESPREAD MODERATE TO HEAVY RAINFALL THEN
DEVELOPING FOR LATER TONIGHT INTO WED MORNING...BEFORE TAPERING TO
SHOWERS AND THUNDERSTORMS BY WED AFTERNOON. AT THIS TIME...IT
APPEARS THAT WIDESPREAD RAINFALL AMTS OF 1-3 INCHES ARE
LIKELY...WITH SOME EMBEDDED HIGHER AMTS OF UP TO 4 INCHES
POSSIBLE.
THE MODERATE TO HEAVY RAINFALL IS EXPECTED TO FALL OVER A LONGER
TIME PERIOD ACROSS THE WESTERN ADIRONDACKS AND LAKE GEORGE SARATOGA
REGION...WHERE ANTECEDENT SOIL MOISTURE IS A BIT LESS. THEREFORE...
AT THIS TIME...IT APPEARS THAT DESPITE THE HEAVY RAINFALL
OCCURRING...THE FACT THAT IT SHOULD FALL OVER A 24-36 HOUR PERIOD
SHOULD REDUCE FLOOD CONCERNS IN THIS REGION.
HOWEVER...SHARP...WITHIN BANK RIVER RISES WILL BE LIKELY.
FURTHER S AND E...WHERE THE FLASH FLOOD WATCH IS IN EFFECT...THE
HEAVY RAINFALL IS EXPECTED TO OCCUR IN A SHORTER TIME PERIOD...WITH
SOME INTENSE RAINFALL RATES POSSIBLE. THIS...IN COMBINATION WITH
SLIGHTLY GREATER SOIL MOISTURE FROM RECENT HEAVY RAINFALL OVER THE
PAST FEW WEEKS INTRODUCES A GREATER THREAT OF FLASH FLOODING OF LOW
LYING...POOR DRAINAGE AND URBAN AREAS...AS WELL AS POSSIBLY SOME
SMALL CREEKS. LARGER STEM RIVER FLOODING IS NOT EXPECTED AT THIS
TIME.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH FROM MIDNIGHT EDT TONIGHT THROUGH WEDNESDAY
AFTERNOON FOR CTZ001-013.
NY...FLASH FLOOD WATCH FROM MIDNIGHT EDT TONIGHT THROUGH WEDNESDAY
AFTERNOON FOR NYZ038>040-047>054-058>061-063>066-082.
MA...FLASH FLOOD WATCH FROM MIDNIGHT EDT TONIGHT THROUGH WEDNESDAY
AFTERNOON FOR MAZ001-025.
VT...FLASH FLOOD WATCH FROM MIDNIGHT EDT TONIGHT THROUGH WEDNESDAY
AFTERNOON FOR VTZ013>015.
&&
$$
SYNOPSIS...KL/GJM
NEAR TERM...KL/BGM
SHORT TERM...KL
LONG TERM...BGM
AVIATION...BGM/NAS
FIRE WEATHER...KL/GJM
HYDROLOGY...KL/GJM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1208 PM EDT MON AUG 11 2014
.SYNOPSIS...
WHILE FAIR WEATHER WITH AN AN ISOLATED SHOWER OR THUNDERSTORM IS
POSSIBLE TODAY...A SLOW MOVING AND COMPLEX LOW PRESSURE SYSTEM
WILL BRING WET WEATHER TO THE REGION TUESDAY NIGHT INTO WEDNESDAY
NIGHT. GRADUALLY IMPROVEMENT AND DRYING IS THEN EXPECTED INTO
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1205 PM UPDATE...
SPC MESO-ANALYSIS SHOWING 500 TO 1000 J/KG OF CAPE HAS DEVELOPED AT
NOON IN A WEAKLY CAPPED ENVIRONMENT. AS A RESULT...ISOLATED SHOWERS
WERE BEGINNING TO POP ACROSS THE REGION. THE HRRR MODEL SEEMS TO
HAVE GOOD HANDLE ON THIS WITH THE THREAT FOR WIDELY SCATTERED
SHOWERS CONTINUING THROUGH THE AFTERNOON. AN ISOLATED THUNDERSTORM
OR TWO IS ALSO POSSIBLE...BUT WITH WEAK WIND FIELDS NOT EXPECTING
SEVERE WEATHER. SLOW MOVEMENT MAY ALLOW FOR BRIEF HEAVY RAINFALL IN
A FEW LOCALES.
OVERALL...MUCH OF THE REGION WILL REMAIN DRY AS THIS ACTIVITY WILL
REMAIN WIDELY SCATTERED. UNDER A MIXTURE OF CLOUDS AND SUN
AFTERNOON HIGHS SHOULD MAINLY BE IN THE 80S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
TONIGHT...
WITH DAYTIME HEATING CONCLUDING...ANY BOUNDARY-LAYER LIFT AND / OR
CONVERGENCE CONCLUDES. HIGH PRESSURE RIDGE REMAINS IN CONTROL...
SINKING AIR WILL ALLOW FOR CLEAR CONDITIONS UNTIL LATE WHEN THIN-
HIGH CLOUDS BEGIN TO FILTER ACROSS THE REGION AHEAD OF THE MIDWEEK
DISTURBANCE.
S-FLOW CONTINUES ADVECTING HIGHER DEWPOINT AIR ONSHORE AND THIS
SHOULD RESULT IN A MILD NIGHT WITH LOW AROUND THE LOW-60S. COMBINED
WITH CONTINUED SINKING AIR...COULD SEE A MIX OF /OR EITHER/ PATCHY
DENSE FOG AND LOW CLOUDS AS MOISTURE POOLS BENEATH THE INVERSION.
MODELS NOT QUITE SUCCINCT ON OUTCOMES AND THERE IS A LAYER OF
UNCERTAINTY.
TUESDAY...
DEEPENING TROUGH OVER THE GREAT LAKES REGION SUBSEQUENTLY AMPLIFIES
THE DOWNSTREAM RIDGE ACROSS NEW ENGLAND AND TO THE E. THIS KEEPS
HIGH PRESSURE IN CONTROL OF THE REGIONS WEATHER MOST OF THE DAY. DRY-
SINKING AIR LINGERS AS BEEN THE CONSISTENT SIGNAL OVER THE LAST
SEVERAL DAYS WORTH OF MODEL-GUIDANCE.
THERE ARE TWO CAMPS OF FORECAST SOLUTIONS: THE ECWMF / GFS BRINGING
RAIN INTO THE CT-VALLEY REGION BY 8 PM TUESDAY...WHEREAS THE NAM /
CANADIAN / WRF KEEP THE AREA COMPLETELY DRY. AS NOTED BY THE PRIOR
FORECASTER...LOW-LEVEL-JET /LLJ/ AXIS WITHIN H925-85 REMAINS W OF
THE REGION ALONG WITH ATTENDANT LOW-LEVEL MOIST CONVERGENCE.
INCREASING ISENTROPIC MOTIONS AND DIFFLUENCE ALOFT PER ALL FORECAST
GUIDANCE AS THE RIDGE SHIFTS E IS A LIKELY CULPRIT FOR ADVECTING THE
HIGH MOISTURE CONTENT THROUGH THE LLJ EASTWARD. SUBSEQUENTLY...WILL
KEEP WITH CHANCE POPS AND MAINLY CONFINE THEM TO THE CT-RIVER VALLEY
REGION BY THE END OF THE PERIOD. FEEL THE E-SHIELD OF PRECIPITATION
WILL ERODE AGAINST THE LINGERING COLUMN OF DRIER AIR.
ANTICIPATING BRISK ONSHORE SE-FLOW CONTINUALLY INCREASING DEWPOINTS
AND HUMIDITY. WHILE SCATTERED-BROKEN CUMULUS DEVELOPS...EXPECT A TOP-
DOWN MOISTENING RESULTING IN THICKENING AND LOWERING MID- TO UPPER-
LEVEL CLOUDS TOWARDS THE LATER-HALF OF THE DAY. THIS SHOULD KEEP
CONDITIONS JUST SLIGHTLY COOLER WITH HIGHS AROUND THE LOW-80S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
OVERVIEW AND MODEL PREFERENCES...
ANOMALOUS UPPER LVL PATTERN /DEEP CUTOFF WITH CONNECTION TO BAFFIN
ISLAND CUTOFF IS EXPECTED TO SETTLE IN ACROSS THE REGION MID WEEK
INTO THE LATTER HALF OF THE WEEK. THIS FEATURES A CUTOFF LOW PRES
GRADUALLY SLIDING E OF THE GREAT LAKES WED-THU...THEN SLOWLY
FILLING AND LIFTING TO THE N FOR FRI INTO THE WEEKEND. THIS STILL
FAVORS UNSETTLED WET WX FOR TUE NIGHT INTO WED NIGHT. THE KEY IS
TIMING...IT NOW APPEARS THAT INITIALLY ECMWF MAY BE THE FAST
OUTLIER FOR TUE NIGHT...BRINGING PRECIP IN TOO FAST IN A BUILDING
RIDGE REGIME. THEREFORE...WILL LEAN ON 00Z GFS AND NAM FOR THE
START. HOWEVER...DO PREFER THE SLOWER TIMING OF PRECIP EXIT GIVEN
THE INCOMING UPPER LVL CUTOFF AND UPPER LVL JET ENERGY IN THE
ECWMF...SO WILL BE LEANING BACK ON IT FOR WED NIGHT INTO THU. FOR
THE REMAINDER OF THE FORECAST...A BLEND OF ENSEMBLES CONTINUES
PROVIDE A GOOD MIDDLE GROUND FOR THE SLOW EXIT OF THIS CUTOFF
DURING THE LATER HALF OF THE WEEK.
DETAILS...
TUE NIGHT INTO WED NIGHT...
DEEP AUGUST CUTOFF WILL BE DEVELOPING WITHIN VICINITY OF THE GREAT
LAKES. THIS WILL LEAD TO A FULL FLEDGED OCCLUSION DEVELOPING IT
AND WHAT APPEARS TO BE FAIRLY HIGH LIKELIHOOD OF TRIPLE POINT LOW
DEVELOPMENT OVER SRN NEW ENGLAND. THIS WILL LEAD TO SEVERAL
POTENTIAL IMPACTS ACROSS THE REGION LATE TUE NIGHT AND THROUGH THE
DAY ON WED AS FOLLOWS...
HEAVY RAIN AND FLASH FLOOD THREAT...
VERY HIGH PWATS APPROACHING 2.0 INCHES /ALMOST 3 STD DEVIATIONS
ABOVE NORMAL/ COMBINED WITH STRONG UPWARD MOTION WITH DEVELOPING
TRIPLE POINT LOW AND STRONG 40-50 KT SLY LLJ WILL ALL FALL IN LINE
TO LEAD TO THE POTENTIAL FOR BANDS OF HEAVY RAIN AIDED BY CONVECTIVE
PROCESSES BEGINNING LATE TUE NIGHT AND CONTINUING INTO WED
AFTERNOON. THIS MAY LEAD TO A LOCALIZED URBAN/POOR DRAINAGE AND
POSSIBLY EVEN SMALL STREAM FLASH FLOOD THREAT SHOULD TRAINING
BECOME AN ISSUE. TOTAL QPF VALUES OF 1.5 INCHES ARE POSSIBLE BUT
SOME 2-3 INCH AMOUNTS CANNOT BE RULED OUT...WITH MUCH OF THIS
POTENTIALLY FALLING OVER A SHORT STRETCH OF TIME. WILL ALSO NEED
TO MONITOR LOCATIONS WHERE TIDES EFFECT DRAINAGE CONSIDERING HIGH
SPRING TIDES WILL ACCOMPANY THIS STORM. STILL A FEW MESO-SCALE
TIMING UNCERTAINTIES WEED THROUGH...SO CONFIDENCE IS NOT HIGH
ENOUGH FOR A WATCH WITH THIS UPDATE...BUT IT WILL BE SOMETHING TO
LOOK AT FOR LATER.
SEVERE WEATHER POTENTIAL...
AS MENTIONED ABOVE THERE IS CERTAINLY ENOUGH LIFT WITHIN THE STRONG
OCCLUSION TO HELP WORK ON AVAILABLE INSTABILITY. AT THIS
POINT...DO NOTE SOME DRY AIR ENTRAINING INTO THE UPPER LVLS OF THE
COLUMN WHICH LOOK TO ENHANCE LATE WED LAPSE RATES SOMEWHAT.
ALSO...IN SPITE OF WHAT IS LIKELY TO BE A FAIR AMOUNT OF CLOUD
COVER AND ONSHORE FLOW...DO NOTE SOME CONDITIONALLY UNSTABLE
PROFILES WITH 500-1000J/KG OF CAPE. ALSO...THE 40-50 KT LLJ DOES
LEAD TO SHEAR PROFILES OF NEAR 25 KT...30 KT...AND 35-40 KT IN THE
0-1KM...0-3KM AND 0-6KM LAYERS RESPECTIVELY. SO CLEARLY A FAIRLY
PRONOUNCED LOW CAPE HIGH SHEAR ENVIRONMENT WITHIN AN AIRMASS THAT
SUPPORTS LOW LCLS OF 900MB OR POTENTIALLY LOWER. THERE IS SOME
UNCERTAINTY THOUGH MAINLY IN THE TIMING AND WHETHER THE LLJ/SHEAR
AND INSTABILITY PEAKS WILL COINCIDE AND WHEN...WHILE THIS IS
PARTIALLY A MODEL ISSUE...IT DOES APPEAR THE BEST LLJ ENERGY MAY
BE EARLY WHILE PEAK INSTABILITY IS CLOSER TO THE CLIMATOLOGICAL
NORM...LATER IN THE DAY. THIS IS IF IT DESTABILIZES AT ALL WITH
MARINE FLOW AND CLOUDS...AND THAT ANY DESTABILIZATION MAY BE MORE
ALOFT THAN AFT THE SFC. STILL WITH THIS PATTERN RESEMBLING WHAT AN
INTERNAL STUDY NOTES AS A TYPE-A PATTERN FOR NEW ENGLAND POTENTIAL
NEW ENGLAND TORNADO DEVELOPMENT...AND GIVEN ALL OF THE ABOVE
FACTORS...AN ISOLATED TORNADO SOMEWHERE IN NEW ENGLAND IS
POSSIBLE. IN ANY CASE...THE STRONG LLJ COULD PRODUCE SOME
STRONG/GUSTY WINDS IN SOME CONVECTIVE ELEMENTS WHICH WOULD HAVE TO
BE WATCHED AS WELL GIVEN THE SHEAR COULD SUPPORT SOME DISCRETE
STRUCTURES.
FINALLY...WITH ONSHORE FLOW AND DEVELOPING LOW PRES IN VICINITY OF
SRN NEW ENGLAND...COMBINING WITH HIGHER THAN NORMAL SPRING
TIDES...WILL HAVE TO MONITOR FOR SOME MINOR COASTAL FLOODING. FOR
MORE INFO...SEE THE COASTAL FLOOD SECTION BELOW.
THU INTO FRI...
UPPER LVL CUTOFF WILL BE SLIDING ACROSS NRN NEW ENGLAND...LEADING TO
A PERIOD OF CYCLONIC FLOW ACROSS THE REGION. A COUPLE OF WEAK
SHORTWAVES ARE LIKELY TO MOVE ACROSS THE AREA AND WORK ON SOME
TRAPPED LOW MOISTURE DESPITE WHAT WILL BE NEARLY STACKED W-NW
FLOW. GIVEN H5 TEMPS TOO DIP TO AROUND -14C...LOOKS LIKE SOME
DIURNAL CLOUDINESS WITH SPOT SHOWERS CAN/T BE RULED OUT ANY DAY.
H85 TEMPS WILL BE DIPPING TO POSSIBLY BELOW +10C...SO HIGHS ARE
LIKELY TO BE BELOW NORMAL UNLESS ENOUGH OF THE STILL RELATIVELY
HIGH AUGUST SUN ANGLE CAN BE REALIZED BETWEEN CLOUDY BREAKS.
NEXT WEEKEND AND EARLY NEXT WEEK... MODEL DIVERGENCE HERE...BUT A
BLEND OF ENSEMBLES AND EVEN THE OPERATIONAL ECMWF TO SOME EXTENT
FAVOR A GRADUAL IMPROVEMENT IN SENSIBLE WX THANKS TO BOTH THE FILLING
AND NORTHWARD LIFT OF THE UPPER LVL CUTOFF. THEREFORE...WILL
FEATURE A MAINLY DRY FORECAST ESPECIALLY AFTER SAT...WITH
GRADUALLY MODERATING TEMPERATURES.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...THROUGH TUESDAY.
TODAY...HIGH CONFIDENCE.
VFR. SOME SCT CU WITH CIGS 060-080 LATER IN THE DAY. OVERNIGHT...A
FEW MORE PATCHES OF FOG EXPECTED...ESPECIALLY AT TYPICALLY PRONE
AIRPORTS.
WINDS BEGIN LIGHT AND VRB...BUT THEN BEGIN TO SHIFT TOWARD THE
SE...THEN FINALLY MAINLY S BY LATE DAY. SEA BREEZES STILL LIKELY
AT THE COASTS WITH FAIRLY TYPICAL STARTING TIMES.
TUESDAY...MODERATE CONFIDENCE.
BREEZY S-WINDS. IFR-LIFR FOG AND CLOUDS IF PRESENT OVERNIGHT MAY
LINGER ALONG THE S-COAST. OTHERWISE CLOUDS LOWERING TO LOW-END
VFR. CHANCE OF SHRA LATE MAINLY ACROSS THE CT-RIVER VALLEY.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF...SEA BREEZE STARTS AGAIN
13-14Z AND MAY SHIFT SLIGHTLY TOWARD THE SE.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
TUE NIGHT INTO WED NIGHT...MODERATE CONFIDENCE.
PERIODS OF MVFR/IFR LIKELY IN RAIN AND FOG. SOME ISOLATED
THUNDERSTORMS ALSO POSSIBLE. GUSTY WINDS POSSIBLE.
THU AND FRI...MODERATE CONFIDENCE.
ALTHOUGH SOME MVFR/IFR MAY LINGER IN SCT SHOWERS AND FOG EARLY
THU...EXPECT SOME IMPROVEMENT WITH MORE VFR THU DAY AND FRIDAY DAY.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...THROUGH TUESDAY...MODERATE CONFIDENCE.
INCREASING S-WINDS REMAINING BELOW 25 KTS ALONG WITH INCREASING
CHANCES OF COASTAL FOG ESPECIALLY DURING THE OVERNIGHT PERIODS.
EXPECTING DRY-WEATHER THROUGHOUT WITH SEAS REMAINING BELOW 5-FEET.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
TUE NIGHT THROUGH WED NIGHT...MODERATE CONFIDENCE.
THERE IS AN INCREASING THREAT FOR SMALL CRAFT ADVISORIES BEGINNING
LATE TUE NIGHT AND CONTINUING INTO WED NIGHT. ALTHOUGH WINDS WILL
BE SHIFTING FROM THE SW...THEN WILL BE VRB ON WED BEFORE SHIFTING
TO THE NW...SOME WINDS AROUND 25 KT CAN/T BE RULED OUT. ALSO...
SEAS WILL BE BUILDING...WITH 5-8FT SWELLS POSSIBLE ON THE OCEAN
WATERS.
THU AND FRI...MODERATE CONFIDENCE.
LOW PRES MOVES TO THE N OF THE REGION...THIS ALLOWS STRONG NW FLOW
TO DEVELOP...WHICH MAY REACH NEAR 25 KT AT TIMES THROUGH THE DAY
THU. SWELLS MAY TAKE SOME TIME TO SUBSIDE FROM THE WED STORM.
THEREFORE...SMALL CRAFT ADVISORIES ARE LIKELY TO LINGER IN SOME FORM
THROUGH THU. BY FRI...WINDS AND SEAS SHOULD GENERALLY BE BELOW
SMALL CRAFT ADVISORY THRESHOLDS.
&&
.TIDES/COASTAL FLOODING...
WEDNESDAY...
A PERIOD OF HIGH SPRING TIDES WILL ACCOMPANY THE STRONG STORM DURING
THE DAY ON WEDNESDAY. THE ONSHORE FLOW FROM THIS STORM MAY LEAD TO
SOME MINOR COASTAL FLOODING AT MAINLY THE WEDNESDAY MID MORNING
/SOUTH COAST/ AND WEDNESDAY AFTERNOON /EAST COAST/ HIGH TIDES.
THE KEY QUESTION WILL BE THE TIMING OF A WAVE OF LOW PRES EXPECTED
TO MOVE ACROSS THE REGION...WHICH LOOKS LIKE IT MAY BE LATER IN THE
DAY THAT PREVIOUSLY THOUGHT. THIS MAY GENERATE JUST ENOUGH
ADDITIONAL SURGE. THERE IS STILL SOME UNCERTAINTY IN EXACTLY HOW
WIDESPREAD THE MINOR COASTAL FLOODING WILL BE...BUT TYPICALLY PRONE
LOCATIONS WILL BE AT HIGHEST RISK.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DOODY/SIPPRELL
NEAR TERM...FRANK
SHORT TERM...SIPPRELL
LONG TERM...DOODY
AVIATION...DOODY/SIPPRELL
MARINE...DOODY/SIPPRELL
TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
746 PM EDT TUE AUG 12 2014
.DISCUSSION...
LATEST RADAR SHOWING LINGERING BOUNDARIES COLLIDING NEAR THE
SOUTHERN TREASURE COAST AND ADDITIONAL CONVECTION IS MOVING
NORTHEAST OFF OF LAKE OKEECHOBEE. HAVE THEREFORE INCREASED POPS
SLIGHTLY TO 30 PERCENT ACROSS ST. LUCIE AND MARTIN COUNTIES.
HOWEVER FROM THE ORLANDO AREA NORTHWARD HAVE REMOVED ANY
ADDITIONAL RAIN CHANCES TONIGHT AS BOUNDARIES ARE NOT EVIDENT IN
THIS REGION AND LOCAL WRF AND HRRR GUIDANCE KEEPS THIS AREA DRY.
DESPITE SOME LINGERING MID TO HIGH CLOUDS...SKIES SHOULD
GENERALLY RANGE FROM MOSTLY CLEAR TO PARTLY CLOUDY OVERNIGHT WITH
LOWS IN THE 70S.
&&
.AVIATION...GENERALLY VFR. ISO SHRA/TSRA STILL POSSIBLE SOUTH OF
KMCO...ESPECIALLY NEAR KFPR/KSUA THIS EVENING...BUT OTHERWISE NO
ADDITIONAL RAIN CHANCES EXPECTED AFTER MIDNIGHT. ISO/SCT
CONVECTION WILL AGAIN PUSH EAST TO NORTHEAST OVER THE REGION
WEDNESDAY AFTERNOON PRODUCING TEMPO IFR/MVFR CONDS.
&&
.MARINE...RIDGE AXIS REMAINS JUST SOUTH OF THE AREA WITH S/SW
WINDS UP TO 10 TO 15 KNOTS TONIGHT. SEAS RANGING FROM 1-2 FEET
NEARSHORE UP TO 2-3 FEET OFFSHORE.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
WEITLICH/KELLY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
335 PM EDT MON AUG 11 2014
...FORECAST AREA REMAINS SPLIT BETWEEN WET CONDITIONS NORTH AND MUCH
DRIER CONDITIONS SOUTH...
.SYNOPSIS...
19Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE NEXT SIGNIFICANT
AMPLIFICATION TO THE MID/UPPER LEVEL PATTERN OVER THE EASTERN CONUS
QUICKLY EVOLVING SOUTHWARD THROUGH THE UPPER MIDWEST. AMPLIFIED
UPSTREAM RIDGING IS SEEN OVER MUCH OF THE INTER-MOUNTAIN WEST. THIS
PATTERN HAS BEEN SO PERSISTENT THIS SUMMER WITH THE WESTERN RIDGE
AND EASTERN TROUGH...AND IT DOES NOT LOOK TO BREAK ANYTIME THIS
WEEK. CLOSER TO HOME...OUR LOCAL AREA REMAINS UNDER THE INFLUENCE OF
WEAK WEST-EAST ORIENTED UPPER RIDGING. A UPPER LEVEL TUTT FEATURE IS
SEEN CLEARLY ON WV IMAGERY UNDER-CUTTING THE UPPER RIDGE...MIGRATING
WESTWARD THROUGH THE FLORIDA STRAITS AND NOW EMERGING INTO THE SE
GULF OF MEXICO. THIS FEATURE IS MOST DEFINED IN THE 400-200MB LAYER
AND IS HAVING THE EFFECT OF ENTRAINING DRIER AIR FROM THE EAST ALOFT
INTO ITS CIRCULATION AND OVER THE SOUTHERN FL PENINSULA.
AT THE SURFACE...SUBTROPICAL RIDGE AXIS REMAINS ALIGNED OVER THE FAR
SOUTHERN FL PENINSULA WITH OUR FORECAST AREA RESIDING BETWEEN
THIS AXIS AND A QUASI-STATIONARY FRONTAL BOUNDARY NEAR/JUST NORTH OF
THE I-10 CORRIDOR. THE RESULTING SYNOPTIC FLOW IS FRONT THE SW. AS
THE LOW LEVEL SW FLOW ROUNDING THE RIDGE AXIS MEETS THE MORE
WESTERLY FLOW JUST AHEAD OF THE FRONT WE HAVE SET UP A PERSISTENT
CONVERGENCE BAND ACROSS THE NE GULF OF MEXICO. THIS LOW LEVEL FOCUS
FOR ASCENT IS HELPING TO FUEL SCT/NMRS SHOWERS AND ISOLATED STORMS
MIGRATING ONSHORE FROM ROUGHLY THE I-4 CORRIDOR NORTHWARD.
&&
.SHORT TERM (REST OF THIS AFTERNOON THROUGH TUESDAY)...
NUMEROUS SHOWERS/STORMS/CLOUDS FROM TAMPA BAY NORTHWARD CONTINUE
INTO THE EARLY EVENING HOURS. WITHOUT THE DEVELOPMENT OF A
SEA-BREEZE TO DISSIPATE THE CONVERGENCE ZONE OVER THE NORTHERN
COASTAL WATERS...THE FOCUS FOR SHOWERS HAS CONTINUED ALL DAY MOVING
ASHORE. LIKELY TO CATEGORICAL POPS (70-100%) FROM THE I-4 CORRIDOR
NORTHWARD WILL REMAIN IN THE GRIDS FOR SEVERAL MORE HOURS AT
LEAST...WITH RAIN CHANCES QUICKLY DECREASING TO THE SOUTH OF
HILLSBOROUGH/POLK COUNTIES. AS EXPECTED A FEW STORMS ARE BEGINNING
TO DEVELOP OVER THE INLAND PORTIONS OF THE SOUTHERN FORECAST
AREA...HOWEVER COVERAGE SHOULD REMAIN LIMITED. CLIMO COVERAGE FOR
THESE REGIONS DURING SW FLOW IN THE SUMMER IS (40-50%). WHEN WE ADD
IN THE DRIER AIR ALOFT...APPROX 30% COVERAGE SEEMS MORE REALISTIC.
SEEING A BIG DIFFERENCE IN TEMPERATURE FROM NORTH TO SOUTH. FREQUENT
SHOWERS/COOLER OUTFLOW/CLOUDS ARE HOLDING TEMPS IN THE UPPER 70S TO
MIDDLE 80S NORTH...WHILE SOUTH OF HILLSBOROUGH/POLK COUNTIES...LOWER
90S ARE COMMON.
LIKELY TO SEE THE SHOWERS DECREASE IN COVERAGE...EVEN OVER THE
NORTHERN HALF OF THE AREA...AS WE HEAD INTO THE MID/LATE EVENING
HOURS. WILL NOT COMPLETELY REMOVE RAIN CHANCES...BUT THE CONVERGENCE
SHOULD BE AT A MINIMUM LATER THIS EVENING INTO THE FIRST HALF OF THE
OVERNIGHT.
TUESDAY...
GLOBAL GUIDANCE HAS CONTINUED TO SHOW THE SUBTROPICAL RIDGE AXIS
MIGRATING A BIT TO THE NORTH (50-75 MILES) BY TUESDAY MORNING.
WHILE THIS MAY NOT SEEM LIKE MUCH...THIS DISPLACEMENT SHOULD NUDGE
THE BEST CONVERGENCE BAND TOMORROW TO THE NORTH AS WELL. DECIDED TO
FOLLOW THIS FORECAST PHILOSOPHY AND HOLD THE BETTER RAIN CHANCES
TUESDAY A BIT MORE TO THE NORTH OF TAMPA BAY (HERNANDO/SUMTER
COUNTIES NORTHWARD). THE PATTERN SEEN TODAY OVER THE SOUTHERN ZONES
WOULD THEN BE EXPANDED NORTHWARD TO ABOUT THE I-4 CORRIDOR...WITH
ONLY SCT ACTIVITY ACROSS HILLSBOROUGH/POLK COUNTIES...AND EVEN LESS
FURTHER SOUTH. THERE IS AGREEMENT BETWEEN THE GFS/ECMWF/AND SREF
ENSEMBLES IN THIS PATTERN SO CONFIDENCE IS A BIT HIGHER THAN WITH
SOME OF THE FORECASTS DURING THE PAST COUPLE OF DAYS.
ONCE AGAIN THE MORE NUMEROUS SHOWERS AND RESULTING CLOUDS ACROSS THE
NATURE COAST SHOULD HOLD HIGH TEMPERATURES DOWN IN THE 80S FOR THE
NATURE COAST WHILE AREAS ALONG AND SOUTH OF I-4 SEE LOWER TO MIDDLE
90S.
&&
.LONG TERM (TUESDAY NIGHT-MONDAY)...
MODEL SOLUTIONS ARE IN GOOD AGREEMENT SHOWING A LONG WAVE UPPER
TROUGH OVER THE WESTERN GREAT LAKES STATES TUESDAY NIGHT AND
WEDNESDAY...DEEPENING AND CLOSING OFF AS IT SHIFTS INTO NORTHERN NEW
ENGLAND AND SOUTHERN QUEBEC BY THE END OF THE WORK WEEK. THE FEATURE
WILL THEN LIFT NORTHEASTWARD AND INTO THE CANADIAN MARITIMES OVER
THE UPCOMING WEEKEND. AT THE SURFACE...THIS WILL DRIVE A FRONTAL
BOUNDARY SOUTHWARD INTO NORTH FLORIDA WHERE IT WILL STALL OUT
THROUGH MUCH OF THE WORK WEEK BEFORE DISSIPATING OVER THE UPCOMING
WEEKEND. THIS WILL ALSO KEEP THE SURFACE HIGH PRESSURE RIDGE AXIS
SUPPRESSED ACROSS THE FLORIDA STRAIGHTS AND SOUTH FLORIDA THROUGH
THE WORK WEEK. THE RIDGE AXIS SHOULD THEN LIFT BACK NORTHWARD INTO
CENTRAL FLORIDA OVER THE UPCOMING WEEKEND AS UPPER LEVEL HEIGHTS
BEGIN TO BUILD OVER THE PENINSULA. OVERALL...EXPECT FAIRLY TYPICAL
SUMMER WEATHER UNDER SOUTHWESTERLY BOUNDARY LAYER FLOW THROUGH THE
PERIOD WITH SCATTERED SHOWERS AND THUNDERSTORMS EACH DAY. THE
SHOWERS AND STORMS WILL DEVELOP EACH NIGHT OVER THE EASTERN GULF AND
DRIFT INTO COASTAL ZONES PRIOR TO DAYBREAK. THE ACTIVITY WILL THEN
TRANSITION INLAND AND INCREASE IN COVERAGE AND INTENSITY DURING THE
AFTERNOON. TEMPERATURES ARE EXPECTED TO RUN NEAR NORMAL THROUGH THE
LONG TERM PERIOD.
&&
.AVIATION...
MAJORITY OF THE RAIN WILL REMAIN TO THE NORTH OF THE I-4 CORRIDOR
INTO THE EARLY EVENING...ALTHOUGH A BRIEF SHOWER OR 2 WILL STILL BE
POSSIBLE AT KTPA/KPIE/KLAL. LOOKING FOR A LET UP IN THE SHOWERS
ACROSS THE NORTH LATER TODAY AND WILL REMOVE SHOWER MENTION FROM THE
ALL TAFS FOR THE OVERNIGHT. ANOTHER ROUND OF SHOWERS SHOULD DEVELOP
LATE TONIGHT INTO TUESDAY MORNING OVER THE NATURE COAST WITH
KTPA/KPIE/KLAL RESIDING ON THE SOUTHERN EDGE OF THIS THREAT AREA.
WILL ADD VCSH BACK INTO THESE NORTHERN TERMINALS AFTER SUNRISE ON
TUESDAY. AWAY FROM ANY SHOWERS...VFR CONDITIONS WILL PREVAIL.
&&
.MARINE...
INTERACTION BETWEEN A FRONTAL BOUNDARY OVER NORTHERN FLORIDA AND THE
SUBTROPICAL RIDGE AXIS ACROSS SOUTHERN FLORIDA WILL KEEP WEST TO
SOUTHWEST FLOW IN PLACE FOR THE NEXT SEVERAL DAYS. THE FLOW WILL BE
A BIT STRONGER TODAY...AROUND 15 KNOTS FOR THE OFFSHORE WATERS
ADJACENT TO THE NATURE COAST. NO HEADLINES ARE EXPECTED OTHERWISE
AND SEAS WILL REMAIN 3 FEET OR LESS. SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED THIS MORNING OVER THE GULF AND NEAR SHORE WATERS...
ESPECIALLY NORTH OF TAMPA BAY. THIS ACTIVITY WILL CONTINUE
THROUGHOUT THE WEEK. MAIN HAZARDS WILL BE SCATTERED
THUNDERSTORMS...DANGEROUS LIGHTNING...AND LOCALIZED GUSTY WINDS IN
AND NEAR THUNDERSTORMS.
&&
.FIRE WEATHER...
RAIN CHANCES WILL REMAIN HIGHEST ALONG THE NATURE COAST TONIGHT AND
INTO TUESDAY. FROM TAMPA BAY SOUTHWARD...AFTERNOON SHOWERS AND
STORMS CAN BE EXPECTED FOR AREAS AWAY FROM THE IMMEDIATE COAST.
OTHERWISE...NO SIGNIFICANT FIRE WEATHER CONCERNS AS RELATIVE
HUMIDITY VALUES WILL REMAIN ABOVE CRITICAL LEVELS THROUGH THE
MIDDLE OF THE WEEK.
FOG POTENTIAL...ISOLATED POCKETS OF SHALLOW PATCHY GROUND FOG
WILL BE POSSIBLE IN OPEN FIELDS EACH MORNING...BUT SIGNIFICANT
VISIBILITY RESTRICTIONS ARE NOT ANTICIPATED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 79 91 79 92 / 30 40 30 30
FMY 77 93 77 93 / 10 20 20 20
GIF 75 94 76 94 / 30 30 10 30
SRQ 79 89 78 92 / 10 20 20 20
BKV 74 89 73 93 / 40 60 30 40
SPG 80 90 80 91 / 30 30 30 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK UNTIL 10 PM EDT THIS EVENING FOR COASTAL
CHARLOTTE-COASTAL HILLSBOROUGH-COASTAL LEE-COASTAL
MANATEE-COASTAL SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION...MROCZKA
MARINE...WYNN
FIRE WEATHER...MCKAUGHAN
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1100 AM EDT MON AUG 11 2014
...FORECAST AREA IS SPLIT BETWEEN WET CONDITIONS NORTH AND DRIER
CONDITIONS SOUTH...
.UPDATE (REST OF TODAY THROUGH TUESDAY)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE NEXT SIGNIFICANT
AMPLIFICATION TO THE MID/UPPER LEVEL PATTERN OVER THE EASTERN CONUS
QUICKLY EVOLVING SOUTHWARD THROUGH THE UPPER MIDWEST. AMPLIFIED
UPSTREAM RIDGING IS SEEN OVER MUCH OF THE INTER-MOUNTAIN WEST. THIS
PATTERN HAS BEEN SO PERSISTENT THIS SUMMER WITH THE WESTERN RIDGE
AND EASTERN TROUGH...AND IT DOES NOT LOOK TO BREAK ANYTIME THIS
WEEK. CLOSER TO HOME...OUR LOCAL AREA REMAINS UNDER THE INFLUENCE OF
WEAK WEST-EAST ORIENTED UPPER RIDGING. A UPPER LEVEL TUTT FEATURE IS
SEEN CLEARLY ON WV IMAGERY THIS MORNING UNDER-CUTTING THE UPPER
RIDGE...MIGRATING WESTWARD THROUGH THE FLORIDA STRAITS AND EMERGING
INTO THE SE GULF OF MEXICO. THIS FEATURE IS MOST DEFINED IN THE
400-200MB LAYER AND IS HAVING THE EFFECT OF ENTRAINING DRIER AIR
FROM THE EAST ALOFT INTO ITS CIRCULATION AND OVER THE SOUTHERN FL
PENINSULA.
11/12Z KTBW SOUNDING PROFILE HAS CHANGED LITTLE IN THE PAST 24
HOURS...STILL SHOWS ABOVE CLIMO PW...BUT NOT UNUSUAL VALUES FOR LATE
SUMMER. H5 TEMPS REMAIN AROUND -6C...WHICH IS FAIRLY WARM...AND
LAPSE RATES THROUGH MUCH OF THE COLUMN ARE NOT FAR FROM MOIST
ADIABATIC. HOWEVER...NO SIGNIFICANT LAYERS OF LOW THETAE ARE NOTED
TO HAVE A NEGATIVE INFLUENCE ON CONVECTIVE COLUMNS. FOR ANOTHER
DAY...CONVECTION SHOULD HAVE LITTLE TROUBLE GROWING IN THIS
ENVIRONMENT...HOWEVER STRONG UPDRAFT AND THE THREAT OF SEVERE
WEATHER IS QUITE LOW. HEADING FURTHER SOUTH TOWARD THE MIAMI KMFL
MORNING SOUNDING...WE FIND A DRIER PROFILE...ESPECIALLY IN THE
MIDDLE/UPPER LEVELS...BUT EVEN SOMEWHAT BELOW 500MB.
AT THE SURFACE...SUBTROPICAL RIDGE AXIS REMAINS ALIGNED OVER THE FAR
SOUTHERN FL PENINSULA WITH OUR FORECAST AREA RESIDING BETWEEN
THIS AXIS AND A QUASI-STATIONARY FRONTAL BOUNDARY NEAR/JUST NORTH OF
THE I-10 CORRIDOR. THE RESULTING SYNOPTIC FLOW IS FRONT THE SW. AS
THE LOW LEVEL SW FLOW ROUNDING THE RIDGE AXIS MEETS THE MORE
WESTERLY FLOW JUST AHEAD OF THE FRONT WE HAVE SET UP A CONVERGENCE
BAND ACROSS THE NE GULF OF MEXICO. THIS LOW LEVEL FOCUS FOR ASCENT
IS HELPING TO FUEL SCT/NMRS SHOWERS AND ISOLATED STORMS MIGRATING
ONSHORE FROM ROUGHLY THE I-4 CORRIDOR NORTHWARD. THE ENSEMBLE NWP
GUIDANCE SUITE HAS BEEN DOING A FAIRLY GOOD JOB WITH THIS PATTERN...
ALTHOUGH THE INITIATION OF PRECIP HAS GENERALLY BEEN ABOUT 3-4 HOURS
TOO EARLY IN THE SIMULATION THE PAST COUPLE OF MORNINGS COMPARED TO
REALITY.
REST OF TODAY AND TONIGHT...
NUMEROUS SHOWERS/STORMS/CLOUDS FROM TAMPA BAY NORTHWARD ARE LIKELY
TO PREVENT MUCH OF A SEA BREEZE ALONG THE NATURE COAST THIS
AFTERNOON. WITHOUT THE SEA-BREEZE TO DISSIPATE THE CONVERGENCE ZONE
OVER THE NORTHERN COASTAL WATERS...WE ARE LIKELY TO SEE THE SHOWERS
CONTINUE MOVING ASHORE INTO THE AFTERNOON. LIKELY POPS FROM THE I-4
CORRIDOR NORTHWARD WILL REMAIN IN THE GRIDS FOR SEVERAL MORE HOURS
AT LEAST...WITH RAIN CHANCES QUICKLY DECREASING TO THE SOUTH OF
HILLSBOROUGH/POLK COUNTIES. DO EXPECT TO SEE SOME LATER AFTERNOON
STORMS OVER THE INLAND PORTIONS OF THE SOUTHERN FORECAST
AREA...HOWEVER COVERAGE SHOULD NOT BE GREAT. CLIMO COVERAGE FOR
THESE REGIONS DURING SW FLOW IN THE SUMMER IS (40-50%). ADD IN THE
DRIER AIR ALOFT AND ~30% LOOKS MORE ACCURATE.
WILL ALSO SEE A BIG DIFFERENCE IN TEMPERATURE FROM NORTH TO SOUTH.
FREQUENT SHOWERS/COOLER OUTFLOW/CLOUDS WILL HOLD TEMPS IN THE 80S
NORTH (PERHAPS UPPER 70S FOR SOME LOCATIONS)...WHILE SOUTH OF TAMPA
BAY...LOWER TO MIDDLE 90S WILL BE COMMON).
LIKELY TO SEE THE SHOWERS DECREASE IN COVERAGE (EVEN OVER THE
NORTHERN HALF OF THE AREA AS WE HEAD LATE INTO THE DAY AND EVENING.
WILL NOT COMPLETELY REMOVE RAIN CHANCES...BUT THE CONVERGENCE SHOULD
BE AT A MINIMUM THIS EVENING INTO THE FIRST HALF OF THE OVERNIGHT.
TUESDAY...
THERE ARE SOME INDICATIONS THAT THE SUBTROPICAL RIDGE AXIS WILL
MIGRATE A BIT TO THE NORTH (50-75 MILES) BY TUESDAY MORNING. WHILE
THIS MAY NOT SEEM LIKE MUCH...THIS MIGHT ALSO DISPLACE THE
CONVERGENCE BAND TOMORROW TO THE NORTH AS WELL. THERE IS SOME
INDICATION OF THIS IN THE LATEST SREF ENSEMBLE OUTPUT. THINKING THE
AFTERNOON FORECAST PACKAGE WILL FOLLOW THIS PHILOSOPHY AND HOLD THE
BETTER RAIN CHANCES TUESDAY TO THE NORTH OF TAMPA BAY (PERHAPS
HERNANDO/SUMTER COUNTIES NORTHWARD). THE PATTERN SEEN TODAY OVER THE
SOUTHERN ZONES WOULD THEN BE EXPANDED NORTHWARD THROUGH THE I-4
CORRIDOR...WITH A MAINLY DRY MORNING FOR ALL...FOLLOWED BY SCT
INLAND DEVELOPMENT FOR THE AFTERNOON. ALL THIS WILL DEPEND ON THE
RIDGE AXIS ACTUAL MOVING NORTH AS THE CURRENT GFS AND ECMWF SHOW.
12Z GUIDANCE PACKAGE WILL BE ARRIVING SHORTLY AND WILL SEE IF THIS
NWP TREND CONTINUES BEFORE MAKING ANY FINAL DECISIONS REGARDING THE
TUESDAY FORECAST. ENJOY THE REST OF YOUR MONDAY!
&&
&&
.AVIATION...
MAIN AVIATION CONCERNS THROUGH EARLY AFTERNOON WILL BE THE NORTHERN
TERMINALS OF KTPA/KPIE/KLAL WHERE PERIOD SHOWERS/STORMS ARE EXPECTED
WITH ASSOCIATED BRIEF PERIODS OF CIG/VIS RESTRICTION IN RAIN.
FURTHER SOUTH...CHANCES FOR ANY SHOWERS AND RESTRICTIONS DECREASES
QUICKLY...AND FEEL COVERAGE WILL BE ISOLATED ENOUGH TO HAVE LEFT OUT
MENTION IN KPGD/KFMY/KRSW. LOOKING FOR A LET UP IN THE SHOWERS
ACROSS THE NORTH LATER TODAY. ANOTHER ROUND OF SHOWERS SHOULD
DEVELOP LATE TONIGHT INTO TUESDAY MORNING OVER THE NATURE COAST WITH
KTPA/KPIE/KLAL RESIDING ON THE SOUTHERN EDGE OF THIS THREAT AREA.
AWAY FROM THE RAIN ASSOCIATED WITH ANY STORMS...VFR CONDITIONS WILL
PREVAIL.
&&
.MARINE...
INTERACTION BETWEEN A FRONTAL BOUNDARY OVER NORTHERN FLORIDA AND THE
SUBTROPICAL RIDGE AXIS ACROSS SOUTHERN FLORIDA WILL KEEP WEST TO
SOUTHWEST FLOW IN PLACE FOR THE NEXT SEVERAL DAYS. THE FLOW WILL BE
A BIT STRONGER TODAY...AROUND 15 KNOTS FOR THE OFFSHORE WATERS
ADJACENT TO THE NATURE COAST. NO HEADLINES ARE EXPECTED OTHERWISE
AND SEAS WILL REMAIN 3 FEET OR LESS. SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED THIS MORNING OVER THE GULF AND NEAR SHORE
WATERS...ESPECIALLY NORTH OF TAMPA BAY. THIS ACTIVITY WILL CONTINUE
THROUGHOUT THE WEEK. MAIN HAZARDS WILL BE SCATTERED
THUNDERSTORMS...DANGEROUS LIGHTNING...AND LOCALIZED GUSTY WINDS IN
AND NEAR THUNDERSTORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 88 78 92 79 / 60 20 30 30
FMY 94 77 93 77 / 20 10 20 20
GIF 89 76 93 76 / 60 10 30 10
SRQ 91 78 91 78 / 40 20 20 20
BKV 87 75 91 73 / 70 30 40 30
SPG 88 80 91 80 / 60 20 30 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...RIP CURRENT RISK THROUGH THIS EVENING FOR COASTAL
CHARLOTTE-COASTAL HILLSBOROUGH-COASTAL LEE-COASTAL
MANATEE-COASTAL SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION...MROCZKA
MARINE...WYNN
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
601 AM EDT MON AUG 11 2014
...ANOTHER ROUND OF HEAVY RAINS AND DANGEROUS FLASH FLOODING
POSSIBLE THROUGH THIS EVENING...
.SYNOPSIS...
A WEAKENING STATIONARY FRONT WILL CONTINUE TO PRODUCE UNSETTLED
WEATHER OVER THE AREA TODAY. A COLD FRONT WILL SHIFT INTO THE
REGION MID TO LATE WEEK...BRINGING DRIER WEATHER TO THE SOUTHEAST
STATES. REMNANTS OF THE LINGERING FRONT COULD LIFT BACK NORTH
THROUGH THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES FOR THE SUNRISE UPDATE. THE 11/09Z RAP PICKED UP
ON THE HEAVY SHOWER ACTIVITY THAT IS CURRENTLY ANCHORED TO HUNTING
ISLAND. EXPECT ADDITIONAL CONVECTION TO SPREAD INLAND TOWARDS THE
CHARLESTON METRO AREA OVER THE NEXT FEW HOURS. COULD SEE AN
ENHANCED FLASH FLOOD THREAT IN THE DOWNTOWN CHARLESTON AREA BY
MID-MORNING WITH HIGH TIDE.
TODAY...ANOTHER ROUND OF HEAVY RAIN AND FLASH FLOODING WILL AFFECT
THE REGION TODAY. THE SYNOPTIC PATTERN HAS CHANGED LITTLE OVER THE
PAST FEW DAYS WITH A STATIONARY FRONT LINGERING OVER THE AREA. AT
11/07Z...THE FRONT WAS POSITIONED ROUGHLY ALONG OR JUST NORTH OF
THE SAVANNAH RIVER AND LINKED UP WITH A WAVE OF LOW PRESSURE
CENTERED WELL SOUTHEAST OF BUOY 41004. MODELS SHOW THE BOUNDARY
REMAINING NEARLY STATIONARY OVER THE AREA TODAY AND WILL SERVE AS
PRIMARY FOCUS FOR CONVECTION TO REFIRE LATER THIS MORNING THIS
AFTERNOON AS WAVES OF SHORTWAVE ENERGY TRAVERSE THE REGION. THE
HIGH RESOLUTION MODELS ARE SIMILAR IN SHOWING NUMEROUS TO
WIDESPREAD SHOWER/TSTMS DEVELOPING THIS AFTERNOON...FIRST
INITIATING OVER THE CHARLESTON TRI-COUNTY AREA LATER THIS MORNING
THEN REDEVELOPING SLOWLY SOUTH THROUGH THE LATE AFTERNOON HOURS.
POPS WILL BE INCREASED TO 70-90 PERCENT FOR ALL AREAS TODAY WITH
HIGHS RANGING FROM THE UPPER 80S/NEAR 90 NORTH TO THE LOWER 90S
SOUTH. SEE THE HYDROLOGY SECTION BELOW FOR ADDITIONAL INFORMATION
ON THE RISK FOR FLASH FLOODING THROUGH TONIGHT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...SIMILAR TO THE PAST FEW NIGHTS...CONVECTION WILL SLOWLY
DIMINISH WITH TIME WITH THE LOSS OF INSOLATION. HOWEVER...WEAK-
MODERATE INSTABILITY WILL REMAIN WHICH WILL FEED AT LEAST
ISOLATED-SCATTERED SHOWERS/TSTMS FOR MUCH OF THE NIGHT. LOWS WILL
RANGE LOWER-MID 70S INLAND TO THE MID-UPPER 70S AT THE COAST.
TUESDAY...THE PATTERN ALOFT WILL BE STEADILY TRANSITIONING...AS
STRONG SHORTWAVE ENERGY DIVES INTO THE GREAT LAKES/OHIO VALLEY
REGIONS AND SENDS AN AMPLIFYING UPPER TROUGH AXIS TOWARD THE EAST
COAST. THE SURFACE PATTERN WILL BE RATHER MUDDLED...WITH A WEAK
WAVE OF LOW PRESSURE ALONG A DIFFUSE BOUNDARY LIFTING NORTH INTO
THE MID ATLANTIC STATES DOWNSTREAM OF THE UPPER TROUGH AXIS. A
RIBBON OF DEEP MOISTURE...WHERE PRECIPITABLE WATER VALUES ARE 2
TO 2.25 INCHES...WILL REMAIN STRETCHED ACROSS THE CAROLINA AND
SOUTHEAST COASTLINE DURING THE MAJORITY OF THE DAY. CONSIDERING
THAT SYNOPTIC SCALE FORCING WILL STILL BE IN THE AREA...EXPECT
SHOWER/THUNDERSTORM COVERAGE TO ONCE AGAIN BE ABOVE SEASONAL
NORMALS. HAVE INDICATED RATHER HIGH RAIN CHANCES IN THE 50 PERCENT
RANGE GENERALLY ALONG AND INLAND OF THE SEABREEZE DURING THE
AFTERNOON HOURS...BEFORE MOISTURE DIMINISHES FROM WEST TO EAST
BEHIND THE DEPARTING LOW SYSTEM OVERNIGHT. STORM MOTIONS WILL BE
NOTABLY FASTER THAN THE PREVIOUS DAY...SUGGESTING THAT HEAVY
RAINFALL POTENTIAL AND LOCALIZED FLOODING WILL BE CONFINED TO
STORMS STALLED ALONG BOUNDARY INTERACTIONS. MID LEVEL DRY AIR EARLY
IN THE DAY AND SLIGHTLY HIGHER WIND FIELDS COULD SUPPORT AN
ISOLATED THUNDERSTORM BECOMING SEVERE AND PRODUCING DAMAGING WIND
GUSTS. ORGANIZED SEVERE WEATHER IS OTHERWISE NOT ANTICIPATED.
TEMPERATURES WILL PEAK IN THE LOWER 90S INLAND UNDER MOSTLY CLOUDY
SKIES.
WEDNESDAY...NUMERICAL MODEL FORECASTS HAVE ACCELERATED THE
APPROACH OF A COLD FRONT DEFINING THE LEADING EDGE OF DRIER HIGH
PRESSURE TO THE WEST/NORTHWEST. LATEST SOLUTIONS SUGGEST THAT THE
FRONT COULD SHIFT INTO THE FORECAST AREA BY LATE DAY...SWEPT
SOUTHEAST BY SHORTWAVE ENERGY EMBEDDED WITHIN THE LIFTING UPPER
TROUGH AXIS. HAVE MAINTAINED SOLID SHOWER/THUNDERSTORM CHANCES
WITH THE SURFACE FRONTAL TROUGH OVER THE FORECAST AREA PROVIDING
ADDITIONAL FORCING. DRIER MODELS ARE HINTING THAT BEST RAIN
COVERAGE COULD BE LIMITED TO THE COASTAL AREAS AND SOUTH OF
INTERSTATE 16 IN SOUTHEAST GEORGIA...CLOSEST TO THE LINGERING BAND
OF DEEP MOISTURE. PRECIPITABLE WATER VALUES WILL BE ON A NOTABLE
DOWNWARD TREND...THUS FLOODING CONCERNS WILL BE LESS THAN SEEN FOR
THE PAST SEVERAL DAYS. HAVE INDICATED THUNDERSTORM POTENTIAL
DIMINISHING FROM NORTHWEST TO SOUTHEAST DURING THE EVENING AND
NIGHTTIME HOURS. HIGH TEMPERATURES WILL REACH THE LOWER 90S UNDER
PARTLY CLOUDY SKIES NORTH TO MOSTLY CLOUDY SKIES SOUTH.
THURSDAY...THE COLD FRONT APPEARS STALLED ALONG THE SOUTHERN
PERIPHERY OF THE FORECAST AREA INTO THE LATE WEEK TIME
FRAME...WITH DEEP MOISTURE CONFINED ALONG AND SOUTH OF INTERSTATE
16 IN SOUTHEAST GEORGIA. A BROAD UPPER TROUGH PATTERN WILL REMAIN
ACROSS THE ENTIRE EASTERN UNITED STATES. HAVE HIGHLIGHTED FAR
SOUTHEAST GEORGIA AND THE SEABREEZE CORRIDOR FOR RAIN CHANCES
AROUND 20 TO 30 PERCENT...WHILE INDICATED ONLY ISOLATED
DEVELOPMENT ELSEWHERE. EXPECT HIGH TEMPERATURES TO BE A DEGREE OR
TWO COOLER THAN EARLIER IN THE WEEK...RANGING FROM 89 TO 92
DEGREES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
DESPITE A PROMINENT AND PERSISTENT UPPER TROUGH ACROSS THE ENTIRE
EASTERN UNITED STATES FOR MUCH OF THE EXTENDED PERIOD...CONVECTIVE
COVERAGE SHOULD RETURN TO MORE SEASONAL NORMALS THROUGH AT LEAST
SUNDAY. HAVE INDICATED SLIGHT CHANCE TO LOW CHANCE POPS EACH
AFTERNOON...FORCED MAINLY BY TYPICAL SEABREEZE CONVERGENCE AND
DIURNAL INSTABILITY. MEDIUM RANGE MODEL SOLUTIONS THEN SUGGEST A
WEST TO EAST ORIENTED BOUNDARY...PERHAPS REMNANTS OF THE LATE WEEK
COLD FRONT...WILL LIFT NORTH AND BRING UNSETTLED WEATHER BACK TO
THE SOUTHEAST STATES FOR EARLY NEXT WEEK. HIGH TEMPERATURES WILL
VARY LITTLE THROUGH THE PERIOD...GENERALLY REACHING THE LOWER 90S
AWAY FROM THE LOCALLY COOLER COASTLINE EACH DAY.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
SO FAR SUB-VFR CONDITIONS HAVE REMAINED WEST OF KCHS. WATCHING
TRENDS FOR A PSBL INCLUSION OF MVFR VSBYS/CIGS JUST BEFORE 12Z TAF
ISSUANCE. AT KSAV...LIFR CIGS HAVE RECENTLY DVLPD. THESE SHOULD
LINGER THROUGH SUNRISE BEFORE LIFTING.
ANOTHER VERY ACTIVE DAY IS EXPECTED ACROSS THE AREA WITH NUMEROUS
TO WIDESPREAD SHOWERS AND TSTMS. IMPACTS PROBABILITIES AT THE
TERMINALS LOOK HIGH AND PREVAILING MVFR TSRA CONDITIONS WILL BE
FORECASTED. LIMITED VSBYS/CIGS TO MVFR FOR NOW...ALTHOUGH TRANSIENT
PERIODS OF IFR/LIFR WILL BE POSSIBLE DURING PERIODS OF THE
HEAVIEST CONVECTIVE RAINFALL. WILL HIGHLIGHT TSTMS FROM 17-22Z AT
KCHS AND 20-02Z AT KSAV. AMENDMENTS WILL MOST CERTAINLY BE ISSUED
THROUGHOUT THE DAY AS TRENDS/TIMING BECOME MORE APPARENT.
EXTENDED AVIATION OUTLOOK...SCATTERED AND MAINLY DIURNAL SHRA/TSRA
WITH BRIEF PERIODS OF FLIGHT RESTRICTIONS ARE EXPECTED FOR TUESDAY
THROUGH THURSDAY.
&&
.MARINE...
TODAY AND TONIGHT...VARIABLE WIND FIELDS WILL REMAIN IN PLACE
THROUGH TONIGHT AS A WEAK STATIONARY WILL CONTINUE TO BISECT THE
LOCAL MARINE AREA. SEAS WILL AVERAGE 1-3 FT.
TUESDAY THROUGH FRIDAY...THE STATIONARY FRONT BECOMES DIFFUSE BY
TUESDAY AS A WEAK WAVE OF LOW PRESSURE LIFTS NORTH OF THE MARINE
ZONES. A MORE WELL-DEFINED COLD FRONT WILL APPROACH FROM THE
WEST/NORTHWEST WEDNESDAY AND SHIFT INTO THE MARINE ZONES THURSDAY
AND FRIDAY. ALTHOUGH THE PRESSURE GRADIENT COULD BRIEFLY TIGHTEN
BETWEEN THE APPROACHING FRONTAL TROUGH AND THE SUB-TROPICAL RIDGE
FAR TO THE SOUTHEAST...MARINE CONDITIONS WILL REMAIN WELL BELOW
ANY ADVISORY HEADLINES THROUGH THE PERIOD.
&&
.HYDROLOGY...
PWATS RUNNING 125-130 PERCENT OF NORMAL COUPLED WITH VERY LIGHT
STEERING WINDS IN THE 925-700 HPA LAYER WILL SUPPORT SLOW STORM
MOTIONS AGAIN TODAY. A SLIGHT VEERING WIND PROFILE NOTED ON
VARIOUS POINT FORECAST SOUNDINGS ALSO SUPPORT A POTENTIAL FOR
BACK-BUILDING AND/OR TRAINING...MAINLY ALONG MESOSCALE BOUNDARY
INTERACTIONS. GIVEN THE POTENTIAL IS THERE FOR TORRENTIAL RAINFALL
AND ADDITIONAL FLASH FLOODING...THE FLASH FLOOD WATCH WILL BE
EXTENDED UNTIL LATE THIS EVENING. HIGH RESOLUTION MODELS SHOW A
WEAK WAVE OF LOW PRESSURE FORMING ALONG THE STATIONARY FRONT LATER
THIS MORNING...WHICH WILL ENHANCE LOW-LEVEL CONVERGENCE ALONG THE
COAST AND THE ATTACHED FRONT THROUGH THIS EVENING. THEREFORE THE
HIGHEST FLOOD THREAT WILL LIKELY BE ACROSS THE COASTAL COUNTIES...
EVEN OUTSIDE OF POTENTIAL TIDAL INFLUENCES. HOWEVER...GROUNDS
REMAIN SATURATED FROM SEVERAL DAYS OF INTENSE RAINFALL AND FLASH
FLOODING IS POSSIBLE JUST ABOUT ANYWHERE TODAY ACROSS SOUTHEAST
SOUTH CAROLINA AND SOUTHEAST GEORGIA. GENERAL RAINFALL AMOUNTS OF
1-3 INCHES IS LIKELY THROUGH TONIGHT WITH ISOLATED AMOUNTS
POTENTIALLY EXCEEDING 5 INCHES.
&&
.TIDES/COASTAL FLOODING...
THIS MORNING...TIDES WILL BE VERY CLOSE TO 7.0 FT MLLW IN THE
CHARLESTON HARBOR. GIVEN ALL THE TIDAL AND FRESH WATER LOADING
THAT HAS BEEN ONGOING OVER THE PAST FEW DAYS...SUSPECT SOME PROBLEMS
WILL LIKELY OCCUR CLOSER TO 6.8 FT MLLW...ESPECIALLY IN DOWNTOWN
CHARLESTON. A COASTAL FLOOD ADVISORY WILL BE ISSUED FOR THE
ENTIRE LOWER SOUTH CAROLINA COAST FROM 7 AM UNTIL 10 AM TO COVER
THIS POTENTIAL EVENT. A PEAK TIDE LEVEL OF 6.9-7.1 FT MLLW WILL BE
FORECASTED IN THE CHARLESTON HARBOR.
TONIGHT...TIDES WILL LIKELY BREACH ADVISORY CRITERIA WITH THE
EVENING HIGH TIDE CYCLE IN THE CHARLESTON HARBOR...BUT IT COULD BE
A BIT MORE MARGINAL FOR FORT PULASKI. WILL DEFER THE NEED FOR A
COASTAL FLOOD ADVISORY FOR THE EVENING HOURS TO THE NEXT FORECAST
SHIFT.
LINGERING INFLUENCES FROM THE RECENT PROXIGEAN SPRING TIDE WILL
CONTINUE TO GENERATE ELEVATED TIDES INTO EARLY THIS WEEK. SINCE
ONLY SMALL DEPARTURES ARE NEEDED ABOVE THE PREDICTED ASTRONOMICAL
TIDE VALUES TO RESULT IN AT LEAST SHALLOW COASTAL FLOODING...THIS
WILL LIKELY BOOST TIDE LEVELS ABOVE CRITICAL THRESHOLDS THROUGH
TUESDAY. THE BEST CHANCE FOR COASTAL FLOOD ADVISORIES WOULD BE
DURING THE EVENING HIGH TIDES. SHOULD HEAVY RAIN OCCUR AROUND THE
TIMES OF THE ELEVATED HIGH TIDES...RUNOFF WILL BE INHIBITED AND
MORE SIGNIFICANT FLOODING COULD OCCUR WITHIN THE COASTAL
COMMUNITIES.
&&
.CLIMATE...
RECORD RAINFALL AMOUNTS FOR 11 AUGUST...
KCHS 7.88 INCHES SET IN 1940...
KCXM 7.66 INCHES SET IN 1940...
KSAV 5.86 INCHES SET IN 1919...
&&
.EQUIPMENT...
THE CHARLESTON SC WSR-88D /KCLX/ REMAINS OUT OF SERVICE DUE TO A
SIGNIFICANT MECHANICAL FAILURE. THE CURRENT ESTIMATE HAS THE RADAR
RETURNING TO SERVICE BETWEEN AUGUST 21 AND 25.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR GAZ087-088-099>101-
114>119-137>141.
SC...FLASH FLOOD WATCH THROUGH THIS EVENING FOR SCZ040-042>045-
047>052.
COASTAL FLOOD ADVISORY UNTIL 11 AM EDT THIS MORNING FOR
SCZ048>051.
MARINE...NONE.
&&
$$
ST/WMS
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
126 AM EDT MON AUG 11 2014
.SYNOPSIS...
A NEARLY STATIONARY FRONTAL ZONE WILL REMAIN IN THE FORECAST AREA
THROUGH TUESDAY RESULTING IN NUMEROUS SHOWERS AND THUNDERSTORMS.
DRIER AIR WILL WORK INTO THE REGION MID WEEK AND LOWER RAIN
CHANCES.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
CONVERGENCE ASSOCIATED WITH THE STALLED FRONT AND HIGH MOISTURE
WILL SUPPORT A CONTINUED CHANCE OF SHOWERS AND THUNDERSTORMS
OVERNIGHT. HOWEVER...EXPECT LITTLE COVERAGE BASED ON RADAR TRENDS
AND NOCTURNAL COOLING. THE LATEST HRRR DISPLAYS JUST ISOLATED
COVERAGE.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH TUESDAY NIGHT/...
THE NAM AND GFS DISPLAY THE FRONT LINGERING IN THE FORECAST AREA
THROUGH MONDAY NIGHT. THE MODELS SHOW PRECIPITABLE WATER OVER 2
INCHES. CONVERGENCE ASSOCIATED WITH THE FRONT AND HIGH MOISTURE
SHOULD SUPPORT SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN POSSIBLE
ONCE AGAIN. THE PATTERN SUPPORTS THE HIGHER GUIDANCE MONDAY
THROUGH MONDAY NIGHT. THE NAM AND GFS INDICATE THE H85 FLOW
BECOMING MORE WESTERLY MONDAY NIGHT. CONVERGENCE MAY DIMINISH AND
WITH NOCTURNAL COOLING THE NAM AND GFS MOS APPEAR REASONABLE WITH
POPS LOWERING TO AROUND 30 PERCENT. USED THE COOLER HIGH
TEMPERATURE GUIDANCE AND WARMER LOW TEMPERATURE GUIDANCE BECAUSE
OF CLOUDINESS THROUGH THE PERIOD...WHICH HAS BEEN THE TREND.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE MODELS INDICATE THAT A FRONT WILL BE MOVING THROUGH THE CWA ON
WEDNESDAY...THEN STALLING ACROSS THE SRN PORTION OF THE CWA OR
JUST TO THE SOUTH. THIS WILL ALLOW THE CWA TO DRY OUT SOMEWHAT AS
PW VALUES DROP BELOW 1.5 INCHES. THE GFS AND ECMWF DISPLAY THE
STALLED FROM OR TROUGH TO REMAIN IN THE VICINITY OF THE FORECAST
AREA THROUGH MUCH OF THE MEDIUM-RANGE PERIOD. THE MODELS SHOW
DEEPER MOISTURE SHIFTING EAST OF THE AREA WEDNESDAY. LEANED
TOWARD AN AVERAGE OF THE GFS...ECMWF...AND EKD MOS FOR THE POP
FORECAST. THE MOS SUPPORTS TEMPERATURES NEAR CLIMATOLOGY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
HIGH CONFIDENCE FOR IFR/LIFR CONDITIONS EARLY THIS MORNING.
FRONTAL BOUNDARY STALLED IN THE CSRA WITH WEDGE CONDITIONS NORTH
OF THE BOUNDARY. WINDS NORTHEAST 5 KNOTS OR LESS OVERNIGHT.
WIDESPREAD MVFR CIGS. HIGH LOW-LEVEL MOISTURE AND NOCTURNAL
COOLING WILL RESULT IN IFR/LIFR CONDITIONS. MODELS INDICATE CIGS
LIFTING TO MVFR LATER THIS MORNING. LOW CONFIDENCE IN TIMING OF CIGS
LIFTING. AS LOW CLOUDS BEGIN TO BREAK UP LATER THIS
AFTERNOON...DIURNAL CONVECTION WILL ONCE AGAIN DEVELOP.
EXTENDED AVIATION OUTLOOK...LATE NIGHT AND MORNING MVFR TO IFR
RESTRICTIONS IN LOW CLOUDS AND/OR FOG EXPECTED...ALONG WITH HIGH
CHANCES OF MAINLY DIURNAL THUNDERSTORMS THROUGH TUESDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
958 PM CDT TUE AUG 12 2014
.DISCUSSION...
815 PM CDT
SOME SMALL ADJUSTMENTS MADE TO THE FORECAST THE REMAINDER OF
TONIGHT. THE MOST NOTABLE ONE...ESPECIALLY FOR STARGAZERS HOPING TO
CATCH THE PERSEID METEOR SHOWER...WAS TO INCREASE SKY COVER
SLIGHTLY LATE TONIGHT. AREA OF CLOSE-CELLED CLOUDS ACROSS NORTHERN
MN INTO FAR NORTHWEST WI IS PROGRESSING SOUTH ON AN ANOMALOUSLY
STRONG AND MERIDIONAL UPPER/MID LEVEL JET FOR SUMMERTIME. THE 00Z
INL SOUNDING INDICATED A SATURATED LAYER ABOUT 7000 FT THICK WITH
THIS. LOOKING AT MODEL SOLUTIONS OF MOISTURE ON CORRELATING
THICKNESSES...THEY DO BRING HIGHER MOISTURE INTO NORTHERN IL LATE
TONIGHT. THE RAP IS THE MOST BULLISH AND BELIEVE TOO MUCH AS SOME
THINNING SHOULD OCCUR. HAVE LEANED MORE TOWARD FEW TO SCATTERED
CLOUDS DRIFTING OVER AREA LATER...NAMELY AFTER 2 AM.
DEW POINTS HAVE BEEN SLOW TO FALL WITH MID TO EVEN SOME UPPER 50S
LINGERING IN NORTH CENTRAL IL...WHICH IS A BIT CONCERNING FOR LOWS
FORECAST TO REACH THE UPPER 40S-LOWER 50S. BELIEVE THE AIR MASS
SHOULD ALLOW THE DEW POINTS TO FALL SOME WITH A CONTINUED LIGHT
NORTHERLY WIND...BUT MAYBE NOT ENOUGH FOR CURRENT FORECAST LOWS.
HAVE BUMPED UP A DEGREE OR TWO IN OUTLYING AREAS AT THIS POINT
AND WILL CONTINUE TO MONITOR.
MTF
//PREV DISCUSSION...
307 PM CDT
AFTERNOON GOES VAPOR IMAGERY DEPICTS STRONG MID-LEVEL SHORT WAVE
CONTINUES TO DIG SOUTHEAST ACROSS SOUTHERN LAKE MICHIGAN/NORTHEAST
ILLINOIS AND NORTHWEST INDIANA. RAIN SHOWERS HAVE DECREASED IN
COVERAGE WITH MAINLY SOME LIGHT SPRINKLES STILL ACROSS PARTS OF COOK
LAKE AND PORTER COUNTIES. PRECIP SHOULD COME TO AN END OVER THE NEXT
COUPLE OF HOURS AS THE MID-LEVEL TROUGH AND VORT AXES MOVE SOUTHEAST
OF THE AREA...WITH RISING HEIGHTS AND SUBSIDENCE WORKING TO ERODE
CLOUD COVER FROM THE WEST/NORTHWEST INTO THIS EVENING. DECREASING
CLOUD COVER OVER THE EASTERN HALF OF THE CWA SHOULD OCCUR IN TIME
FOR METEOR SHOWER VIEWING OVERNIGHT. COOLER/DRIER AIR FILTERING INTO
THE REGION FROM THE NORTH...COMBINED WITH DECREASING WINDS TONIGHT
AS SURFACE HIGH PRESSURE DRIFTS EAST ACROSS THE PLAINS AND ALLOWS
WEAKENING OF THE GRADIENT EAST OF THE MISSISSIPPI...WILL ALLOW FOR
TEMPS TO FALL INTO THE LOWER 50S AWAY FROM THE CITY AND EVEN INTO
THE UPPER 40S IN SOME OF THE TYPICALLY COLDER SPOTS.
ON WEDNESDAY...NORTHWEST FLOW CONTINUES ALOFT WITH DEEP TROUGH OVER
EASTERN NORTH AMERICA. GUIDANCE HAS BEEN PERSISTENT IN BRINGING A
SHORT WAVE SOUTHEAST THROUGH THE WESTERN PERIPHERY OF THE EASTERN
TROUGH WITH A WEAK SURFACE REFLECTION AND COLD FRONTAL TROUGH WHICH
PUSHES SOUTH FROM WI AND ACROSS NORTHERN IL/IN DURING THE LATE
AFTERNOON AND EVENING HOURS. MOST MODELS SQUEEZE OUT SOME VERY LIGHT
SPOTTY QPF ALONG/AHEAD OF THE FRONT IN THE AFTERNOON...THOUGH IT
APPEARS THAT MODEL BOUNDARY LAYER MOISTURE IS A BIT OVERDONE WHICH
IN TURN YIELDS WEAK CAPE/MOIST LAYER THAT IS ALSO SUSPECTED TO BE
OVER-FORECAST. THUS HAVE MAINTAINED DRY FORECAST THROUGH WEDNESDAY
WITH FRONTAL PASSAGE. FRONT/TROUGH MAY "BACK-DOOR" INTO FAR
NORTHEAST IL TOWARD EVENING BRINGING A QUICK COOLING INTO THE 60S
ALONG THE LAKE MICHIGAN SHORE ESPECIALLY IN LAKE COUNTY IL.
OTHERWISE...SHOULD BE A GOOD DEAL OF SUNSHINE WITH TEMPS REBOUNDING
TO AROUND 80/LOW 80S ACROSS WESTERN CWA WEDNESDAY...AND IN THE
MID-UPPER 70S FARTHER EAST. COOL 50S (AWAY FROM THE URBAN CORE OF
CHICAGO) EXPECTED BEHIND THE FRONT WEDNESDAY NIGHT...WITH ANOTHER
PLEASANT DAY THURSDAY WITH 70S EAST TO NEAR 80 WEST AS HIGH PRESSURE
BUILDS INTO THE REGION. HIGH PRESSURE REMAINS IN CONTROL INTO FRIDAY
THOUGH THE CENTER OF THE HIGH SLIDES EAST...ALLOWING DEVELOPMENT OF
SOUTHERLY RETURN FLOW AND ASSOCIATED WARM/MOIST ADVECTION ACROSS THE
PLAINS AND MISSISSIPPI VALLEY.
THE EXTENDED FORECAST PERIOD SATURDAY-TUESDAY LOOKS TO HAVE WARMER
TEMPS...BUT ALSO PERIODIC CHANCES OF THUNDERSTORMS AS SOUTHERLY LOW
LEVEL FLOW SETS UP AND SLOW MOVING MID-LEVEL DISTURBANCE MOVES
SLOWLY WEST TO EAST ACROSS THE REGION. TIMING DIFFERENCES DO EXIST
BETWEEN THE GLOBAL RUNS BEYOND THE FRIDAY NIGHT-SATURDAY PERIOD.
GOOD AGREEMENT IN DEVELOPMENT OF SURFACE LOW AND WARM FRONT FROM
NORTHERN MO/IA BORDER EAST INTO IN/OHIO VALLEY REGION WITH PRECIP
PRODUCTION AT VARIOUS TIMES EACH DAY. WITH DETAIL DIFFERENCES
INCREASING INTO THE MONDAY/TUESDAY TIMEFRAME HAVE MAINTAINED A
BLENDED GUIDANCE APPROACH WITH CHANCE POPS AND TEMPS WARMING INTO
THE LOW/MID 80S...THEN COOLING FROM THE NORTH A BIT TUESDAY WITH
HINT OF COLD FRONTAL TROUGH PASSAGE. PROBABLY NOT A TOTAL RAIN-OUT
IN REALITY FOR THE WEEKEND...AND FORECAST WILL BE REFINED AS THE
DETAILS BECOME CLEARER OVER THE NEXT SEVERAL DAYS.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* CHANCE FOR WINDS TO TURN NELY LATE TOMORROW AFTERNOON/EARLY
EVENING. SPEED SHOULD BE LESS THAN 10KT.
KREIN
//DISCUSSION...UPDATED 00Z...
AS THE DEEP SFC LOW LIFTS THROUGH SRN ONTARIO TO CENTRAL
QUEBEC...HIGH PRESSURE IS BUILDING ACROSS THE CENTRAL AND NRN
MISSISSIPPI VALLEY AND INTO WESTERN GREAT LAKES AND UPPER MIDWEST.
THE DENSE CLOUD COVER ASSOCIATED WITH THE LOW IS MOVING OFF TO
THE EAST AND THE DIURNAL CU IS DISSIPATING WITH SUNSET. ANTICIPATE
THAT CONDITIONS SHOULD BE QUIET FOR THE REMAINDER OF THE EVENING
AND OVERNIGHT WITH MOSTLY CLEAR SKIES AND LIGHT AND VARIABLE
WINDS. A WEAK SFC TROUGH IS EXPECTED TO DROP SOUTH THROUGH
WISCONSIN TONIGHT AND INTO NRN IL TOMORROW SETTING UP LIGHT WEST
FLOW WHICH SHOULD TOP OUT AT 10KT IN THE AFTERNOON. CYCLONIC FLOW
ALOFT SHOULD AID IN INCREASING DIURNAL CU COVERAGE THROUGH THE
MORNING AND INTO THE AFTERNOON...BUT SKY COVER SHOULD REMAIN VFR.
HIGH PRESSURE BUILDING ACROSS NRN LAKE MICHIGAN LATE TOMORROW
AFTERNOON OR EARLY TOMORROW EVENING COULD SET UP A WIND SHIFT TO
NELY...BUT A WEAK GRADIENT SHOULD BE IN PLACE AND WINDS WILL BE
LESS THAN 10KT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* LOW CONFIDENCE IN A WIND SHIFT TO NELY LATE TOMORROW AFTERNOON
OR EARLY TOMORROW EVENING.
* MEDIUM TO HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR. WX NIL.
FRIDAY...VFR. WX NIL. LAKE BREEZE DEVELOPMENT POSSIBLE.
FRIDAY NIGHT THROUGH MONDAY...PERIODIC CHANCES SHRA/TSRA. OCNL
PERIODS OF MVFR CIGS/VIS POSSIBLE.
KREIN
&&
.MARINE...
252 PM CDT
WITH LOW PRESSURE JUST NORTHEAST OF THE LAKE AND A FAIRLY TIGHT
PRESSURE GRADIENT OVER THE LAKE...WINDS AND WAVES DID
INCREASE/BUILD ACROSS THE ENTIRE LAKE. BOTH BUOY AND SHIP OBS HAVE
REPORTED AROUND GALES OR SLIGHTLY HIGHER OVER THE LAST COUPLE OF
HOURS...WITH TO 30 KT WINDS BEING REPORTED ELSEWHERE. GRADIENT
OVER THE LAKE WILL BEGIN WEAKENING THIS AFTERNOON WITH SPEEDS
DIMINISHING THROUGH THE EVENING TIME FRAME. WILL CANCEL/EXPIRE THE
GALE WARNING IN PLACE THROUGH 20Z AS THE STRONGEST WINDS SHOULD BE
OVER. WILL LIKELY MAKE MENTION OF A FEW GALE FORCE GUSTS FOR THE
REMAINDER OF THE AFTERNOON IN THE GLF NORTH HALF...AS STRONGER
WINDS JUST OFF THE SURFACE COULD STILL MIX DOWN OVER THE NEXT
COUPLE OF HOURS. SCA TIMING STILL APPEARS TO BE IN GOOD SHAPE WITH
THE WINDS DIMINISHING THIS AFTERNOON...BUT WITH HIGHER WAVES STILL
LINGERING THROUGH TONIGHT AND EARLY WEDNESDAY MORNING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 4 AM WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
&&
$$
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AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
816 PM CDT TUE AUG 12 2014
.DISCUSSION...
815 PM CDT
SOME SMALL ADJUSTMENTS MADE TO THE FORECAST THE REMAINDER OF
TONIGHT. THE MOST NOTABLE ONE...ESPECIALLY FOR STARGAZERS HOPING TO
CATCH THE PERSEID METEOR SHOWER...WAS TO INCREASE SKY COVER
SLIGHTLY LATE TONIGHT. AREA OF CLOSE-CELLED CLOUDS ACROSS NORTHERN
MN INTO FAR NORTHWEST WI IS PROGRESSING SOUTH ON AN ANOMALOUSLY
STRONG AND MERIDIONAL UPPER/MID LEVEL JET FOR SUMMERTIME. THE 00Z
INL SOUNDING INDICATED A SATURATED LAYER ABOUT 7000 FT THICK WITH
THIS. LOOKING AT MODEL SOLUTIONS OF MOISTURE ON CORRELATING
THICKNESSES...THEY DO BRING HIGHER MOISTURE INTO NORTHERN IL LATE
TONIGHT. THE RAP IS THE MOST BULLISH AND BELIEVE TOO MUCH AS SOME
THINNING SHOULD OCCUR. HAVE LEANED MORE TOWARD FEW TO SCATTERED
CLOUDS DRIFTING OVER AREA LATER...NAMELY AFTER 2 AM.
DEW POINTS HAVE BEEN SLOW TO FALL WITH MID TO EVEN SOME UPPER 50S
LINGERING IN NORTH CENTRAL IL...WHICH IS A BIT CONCERNING FOR LOWS
FORECAST TO REACH THE UPPER 40S-LOWER 50S. BELIEVE THE AIR MASS
SHOULD ALLOW THE DEW POINTS TO FALL SOME WITH A CONTINUED LIGHT
NORTHERLY WIND...BUT MAYBE NOT ENOUGH FOR CURRENT FORECAST LOWS.
HAVE BUMPED UP A DEGREE OR TWO IN OUTLYING AREAS AT THIS POINT
AND WILL CONTINUE TO MONITOR.
MTF
&&
.PREV DISCUSSION...
307 PM CDT
AFTERNOON GOES VAPOR IMAGERY DEPICTS STRONG MID-LEVEL SHORT WAVE
CONTINUES TO DIG SOUTHEAST ACROSS SOUTHERN LAKE MICHIGAN/NORTHEAST
ILLINOIS AND NORTHWEST INDIANA. RAIN SHOWERS HAVE DECREASED IN
COVERAGE WITH MAINLY SOME LIGHT SPRINKLES STILL ACROSS PARTS OF COOK
LAKE AND PORTER COUNTIES. PRECIP SHOULD COME TO AN END OVER THE NEXT
COUPLE OF HOURS AS THE MID-LEVEL TROUGH AND VORT AXES MOVE SOUTHEAST
OF THE AREA...WITH RISING HEIGHTS AND SUBSIDENCE WORKING TO ERODE
CLOUD COVER FROM THE WEST/NORTHWEST INTO THIS EVENING. DECREASING
CLOUD COVER OVER THE EASTERN HALF OF THE CWA SHOULD OCCUR IN TIME
FOR METEOR SHOWER VIEWING OVERNIGHT. COOLER/DRIER AIR FILTERING INTO
THE REGION FROM THE NORTH...COMBINED WITH DECREASING WINDS TONIGHT
AS SURFACE HIGH PRESSURE DRIFTS EAST ACROSS THE PLAINS AND ALLOWS
WEAKENING OF THE GRADIENT EAST OF THE MISSISSIPPI...WILL ALLOW FOR
TEMPS TO FALL INTO THE LOWER 50S AWAY FROM THE CITY AND EVEN INTO
THE UPPER 40S IN SOME OF THE TYPICALLY COLDER SPOTS.
ON WEDNESDAY...NORTHWEST FLOW CONTINUES ALOFT WITH DEEP TROUGH OVER
EASTERN NORTH AMERICA. GUIDANCE HAS BEEN PERSISTENT IN BRINGING A
SHORT WAVE SOUTHEAST THROUGH THE WESTERN PERIPHERY OF THE EASTERN
TROUGH WITH A WEAK SURFACE REFLECTION AND COLD FRONTAL TROUGH WHICH
PUSHES SOUTH FROM WI AND ACROSS NORTHERN IL/IN DURING THE LATE
AFTERNOON AND EVENING HOURS. MOST MODELS SQUEEZE OUT SOME VERY LIGHT
SPOTTY QPF ALONG/AHEAD OF THE FRONT IN THE AFTERNOON...THOUGH IT
APPEARS THAT MODEL BOUNDARY LAYER MOISTURE IS A BIT OVERDONE WHICH
IN TURN YIELDS WEAK CAPE/MOIST LAYER THAT IS ALSO SUSPECTED TO BE
OVER-FORECAST. THUS HAVE MAINTAINED DRY FORECAST THROUGH WEDNESDAY
WITH FRONTAL PASSAGE. FRONT/TROUGH MAY "BACK-DOOR" INTO FAR
NORTHEAST IL TOWARD EVENING BRINGING A QUICK COOLING INTO THE 60S
ALONG THE LAKE MICHIGAN SHORE ESPECIALLY IN LAKE COUNTY IL.
OTHERWISE...SHOULD BE A GOOD DEAL OF SUNSHINE WITH TEMPS REBOUNDING
TO AROUND 80/LOW 80S ACROSS WESTERN CWA WEDNESDAY...AND IN THE
MID-UPPER 70S FARTHER EAST. COOL 50S (AWAY FROM THE URBAN CORE OF
CHICAGO) EXPECTED BEHIND THE FRONT WEDNESDAY NIGHT...WITH ANOTHER
PLEASANT DAY THURSDAY WITH 70S EAST TO NEAR 80 WEST AS HIGH PRESSURE
BUILDS INTO THE REGION. HIGH PRESSURE REMAINS IN CONTROL INTO FRIDAY
THOUGH THE CENTER OF THE HIGH SLIDES EAST...ALLOWING DEVELOPMENT OF
SOUTHERLY RETURN FLOW AND ASSOCIATED WARM/MOIST ADVECTION ACROSS THE
PLAINS AND MISSISSIPPI VALLEY.
THE EXTENDED FORECAST PERIOD SATURDAY-TUESDAY LOOKS TO HAVE WARMER
TEMPS...BUT ALSO PERIODIC CHANCES OF THUNDERSTORMS AS SOUTHERLY LOW
LEVEL FLOW SETS UP AND SLOW MOVING MID-LEVEL DISTURBANCE MOVES
SLOWLY WEST TO EAST ACROSS THE REGION. TIMING DIFFERENCES DO EXIST
BETWEEN THE GLOBAL RUNS BEYOND THE FRIDAY NIGHT-SATURDAY PERIOD.
GOOD AGREEMENT IN DEVELOPMENT OF SURFACE LOW AND WARM FRONT FROM
NORTHERN MO/IA BORDER EAST INTO IN/OHIO VALLEY REGION WITH PRECIP
PRODUCTION AT VARIOUS TIMES EACH DAY. WITH DETAIL DIFFERENCES
INCREASING INTO THE MONDAY/TUESDAY TIMEFRAME HAVE MAINTAINED A
BLENDED GUIDANCE APPROACH WITH CHANCE POPS AND TEMPS WARMING INTO
THE LOW/MID 80S...THEN COOLING FROM THE NORTH A BIT TUESDAY WITH
HINT OF COLD FRONTAL TROUGH PASSAGE. PROBABLY NOT A TOTAL RAIN-OUT
IN REALITY FOR THE WEEKEND...AND FORECAST WILL BE REFINED AS THE
DETAILS BECOME CLEARER OVER THE NEXT SEVERAL DAYS.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* CHANCE FOR WINDS TO TURN NELY LATE TOMORROW AFTERNOON/EARLY
EVENING. SPEED SHOULD BE LESS THAN 10KT.
KREIN
//DISCUSSION...UPDATED 00Z...
AS THE DEEP SFC LOW LIFTS THROUGH SRN ONTARIO TO CENTRAL
QUEBEC...HIGH PRESSURE IS BUILDING ACROSS THE CENTRAL AND NRN
MISSISSIPPI VALLEY AND INTO WESTERN GREAT LAKES AND UPPER MIDWEST.
THE DENSE CLOUD COVER ASSOCIATED WITH THE LOW IS MOVING OFF TO
THE EAST AND THE DIURNAL CU IS DISSIPATING WITH SUNSET. ANTICIPATE
THAT CONDITIONS SHOULD BE QUIET FOR THE REMAINDER OF THE EVENING
AND OVERNIGHT WITH MOSTLY CLEAR SKIES AND LIGHT AND VARIABLE
WINDS. A WEAK SFC TROUGH IS EXPECTED TO DROP SOUTH THROUGH
WISCONSIN TONIGHT AND INTO NRN IL TOMORROW SETTING UP LIGHT WEST
FLOW WHICH SHOULD TOP OUT AT 10KT IN THE AFTERNOON. CYCLONIC FLOW
ALOFT SHOULD AID IN INCREASING DIURNAL CU COVERAGE THROUGH THE
MORNING AND INTO THE AFTERNOON...BUT SKY COVER SHOULD REMAIN VFR.
HIGH PRESSURE BUILDING ACROSS NRN LAKE MICHIGAN LATE TOMORROW
AFTERNOON OR EARLY TOMORROW EVENING COULD SET UP A WIND SHIFT TO
NELY...BUT A WEAK GRADIENT SHOULD BE IN PLACE AND WINDS WILL BE
LESS THAN 10KT.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* LOW CONFIDENCE IN A WIND SHIFT TO NELY LATE TOMORROW AFTERNOON
OR EARLY TOMORROW EVENING.
* MEDIUM TO HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR. WX NIL.
FRIDAY...VFR. WX NIL. LAKE BREEZE DEVELOPMENT POSSIBLE.
FRIDAY NIGHT THROUGH MONDAY...PERIODIC CHANCES SHRA/TSRA. OCNL
PERIODS OF MVFR CIGS/VIS POSSIBLE.
KREIN
&&
.MARINE...
252 PM CDT
WITH LOW PRESSURE JUST NORTHEAST OF THE LAKE AND A FAIRLY TIGHT
PRESSURE GRADIENT OVER THE LAKE...WINDS AND WAVES DID
INCREASE/BUILD ACROSS THE ENTIRE LAKE. BOTH BUOY AND SHIP OBS HAVE
REPORTED AROUND GALES OR SLIGHTLY HIGHER OVER THE LAST COUPLE OF
HOURS...WITH TO 30 KT WINDS BEING REPORTED ELSEWHERE. GRADIENT
OVER THE LAKE WILL BEGIN WEAKENING THIS AFTERNOON WITH SPEEDS
DIMINISHING THROUGH THE EVENING TIME FRAME. WILL CANCEL/EXPIRE THE
GALE WARNING IN PLACE THROUGH 20Z AS THE STRONGEST WINDS SHOULD BE
OVER. WILL LIKELY MAKE MENTION OF A FEW GALE FORCE GUSTS FOR THE
REMAINDER OF THE AFTERNOON IN THE GLF NORTH HALF...AS STRONGER
WINDS JUST OFF THE SURFACE COULD STILL MIX DOWN OVER THE NEXT
COUPLE OF HOURS. SCA TIMING STILL APPEARS TO BE IN GOOD SHAPE WITH
THE WINDS DIMINISHING THIS AFTERNOON...BUT WITH HIGHER WAVES STILL
LINGERING THROUGH TONIGHT AND EARLY WEDNESDAY MORNING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 4 AM WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
527 PM CDT MON AUG 11 2014
.DISCUSSION...
257 PM CDT
NEAR TERM FORECAST FOCUS DEALS SHOWER/THUNDERSTORM COVERAGE THROUGH
THIS EVENING...AND ADDITIONAL SHOWER CHANCES THROUGH AT LEAST
TUESDAY MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA.
EARLY AFTERNOON SURFACE ANALYSIS DEPICTS TWO SEPARATE AREAS OF LOW
PRESSURE...ONE OVER CENTRAL WISCONSIN AND THE OTHER ACROSS WESTERN
OHIO. BOTH OF THESE SURFACE LOWS WERE ASSOCIATED WITH FAIRLY STOUT
MID-LEVEL SHORT WAVES WHICH WERE ALSO RESPONSIBLE FOR A LARGE AREA
OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WI ACROSS LAKE MICHIGAN
TO THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION THIS AFTERNOON. FOR
OUR LOCAL AREA...THE STRONG SHORT WAVE TROUGH SEEN IN GOES VAPOR
IMAGERY OVER MINNESOTA WILL BE THE MAIN DRIVER IN OUR WEATHER AND
PRECIP TRENDS OVER THE NEXT 18 HOURS OR SO...AS IT CONTINUES TO DIG
SOUTHEAST ACROSS NORTHERN IL THROUGH TUESDAY MORNING. ALONG WITH ITS
SURFACE REFLECTION OVER WI...A COLD FRONT EXTENDING ALONG THE
MISSISSIPPI RIVER WILL PUSH SOUTHEAST THROUGH THIS EVENING...AND
WILL BE THE FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS. WHILE SURFACE
WINDS WERE ALREADY WEST-NORTHWEST AHEAD OF THE FRONT ITSELF...THUS
REDUCING CONVERGENCE ALONG THE BOUNDARY...STEEP LOW LEVEL LAPSE
RATES AND RAP MESOANALYSIS MLCAPES OF 500-1000 J/KG SHOULD BE ENOUGH
TO SUSTAIN SHOWERS/THUNDERSTORMS AHEAD OF THE FRONT THROUGH EARLY
EVENING. IN ADDITION...A FEW SHOWERS HAD DEVELOPED ALONG THE LAKE
BREEZE FROM SOUTHEAST WI INTO NORTHEAST IL...AND THESE SHOWERS AND
ISOLATED THUNDERSTORMS MAY ALSO FESTER A BIT AHEAD OF THE FRONT. ANY
OF THE STRONGER STORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS...AND
PERHAPS SOME BRIEF GUSTY WINDS WITH STORMS ALONG THE FRONT DUE TO
THE STEEP LOW LEVEL LAPSE RATES.
THE STRONG MINNESOTA SHORT WAVE WILL AMPLIFY/DEEPEN AN UPPER TROUGH
OVER THE WESTERN LAKES TONIGHT...WITH THE SURFACE LOWS CONSOLIDATING
AND DEEPENING OVER LOWER MICHIGAN. A FEW SHOWERS MAY LINGER OVER
NORTHEASTERN PARTS OF THE CWA AND SOUTHERN LAKE MICHIGAN TUESDAY
MORNING AS THE MAIN VORT MOVES THROUGH...BEFORE SUBSIDENCE INDICATED
BY 40 METER H5 HEIGHT RISES SPREADS IN DURING THE AFTERNOON. NORTH
WINDS STRENGTHENING BEHIND THE DEEPENING LOW WILL EVENTUALLY PULL
COOLER AND DRIER AIR INTO THE REGION TUESDAY AFTERNOON/NIGHT. AFTER
TEMPS REACHING THE LOW 80S TODAY (WHERE CLOUDS DID NOT PREVENT
IT)... COOLER 70S EXPECTED FOR HIGHS TUESDAY...AND SOME LOW 50S FOR
LOWS TUESDAY NIGHT!
GUIDANCE INDICATES ANOTHER WEAKER SHORT-WAVE DROPPING SOUTHEAST
ACROSS THE WESTERN LAKES WEDNESDAY...WITH A WEAK SURFACE WAVE AND
TROUGH PUSHING SOUTH ACROSS THE REGION DURING THE AFTERNOON. SOME
MODELS ARE TRYING TO SQUEEZE OUT A LITTLE PATCHY LIGHT QPF HINTING
AT SOME SHOWERS ALONG/AHEAD OF THE TROUGH DURING THE AFTERNOON...
THOUGH MOST OF THIS IS ACROSS WI/NORTHEAST IA AND HAVE LOW ENOUGH
CONFIDENCE IN IT IMPACTING THE FORECAST AREA TO LEAVE IT OUT OF THE
FORECAST AT THIS TIME. SIMILAR POTENTIAL FOR THURSDAY AFTERNOON
FARTHER SOUTH DEPENDING UPON WHERE THE TROUGH IS BY THEN. OTHERWISE
HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY NIGHT AND THURSDAY
WITH LIGHTER WINDS AND A MODERATION IN TEMPS BACK TO THE 75-80
DEGREE RANGE THURSDAY AND AROUND 80 FRIDAY WITH ATTENDANT LAKE
BREEZES. THE HIGH THEN DRIFTS OFF TO THE EAST FRIDAY NIGHT AND
SATURDAY...WITH AN EVENTUAL RETURN OF WARM/MOIST ADVECTION FLOW INTO
THE WEEKEND AND EARLY NEXT WEEK. IN THE EXTENDED RANGE...GEM...GFS
AND ECMWF ALL BRING SOME PRECIP POTENTIAL BACK TO THE AREA BY FRIDAY
NIGHT...THOUGH THERE ARE SOME TIMING DIFFERENCES BETWEEN THE GLOBAL
GUIDANCE BY DAYS 6-7. THUS HAVE MAINTAINED BLENDED GUIDANCE APPROACH
WITH GENERALLY LOW-CHANCE POPS AND TEMPS WARMING BACK INTO THE
LOW-MID 80S THROUGH THE WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* CHANCE FOR SHRA/TSRA WITH AN UPPER LEVEL DISTURBANCE EARLY THIS
EVENING. WINDOW OF OPPORTUNITY SHOULD BE RELATIVELY SHORT.
* ANOTHER CHANCE FOR SHRA/TSRA WITH A COLD FRONT PASSAGE
OVERNIGHT.
* MVFR/IFR CIGS BEHIND THE COLD FRONT EARLY TUESDAY MORNING.
KREIN
//DISCUSSION...UPDATED 18Z...
A COMPLEX UPPER LEVEL PATTERN IS LARGELY RESPONSIBLE FOR SHAPING
THE WEATHER OVER THE AREA THROUGH THE NEXT 24-30 HRS.
MEANWHILE...AT THE SFC...A WEAK PRESSURE GRADIENT IS IN PLACE
AHEAD OF AN APPROACHING COLD FRONT...WHICH MAY HELP INDUCE A LAKE
BREEZE THIS AFTERNOON. HOWEVER...INITIALLY...HAVE DELAYED THE CIGS
IMPROVING FROM MVFR TO VFR BASED ON LATEST SATELLITE TRENDS. THE
BACK EDGE OF THE THICKER LOWER CLOUD IS SLOWING AS CU DEVELOPMENT
BEGINS TO FILL IN THE CLEAR SLOT BETWEEN THE APPROACHING COLD
FRONT FROM THE NORTHWEST AND THE EXITING MID LEVEL IMPULSE OFF TO
THE NORTHEAST. BY LATE THIS AFTERNOON...THE CLEARING SKIES AND
WEAK GRADIENT SHOULD ALLOW THE LAKE BREEZE TO FORM...TURNING WINDS
TO MORE NELY AT THE CHICAGO AREA TERMINALS. WITH A VERY MOIST
AIRMASS IN PLACE...THE LAKE BREEZE BOUNDARY SHOULD BE THE FOCUS
FOR ADDITIONAL SCT SHOWERS AND POSSIBLE AN ISOLATED THUNDERSTORM.
THE WEAK COLD FRONT IS STILL EXPECTED TO PUSH ACROSS THE AREA LATE
THIS EVENING...TURNING WINDS MORE NWLY. BY THE EARLY MORNING HOURS
TUESDAY MORNING...DRIER AIR ALOFT IS EXPECTED TO OVERSPREAD THE LOW
LEVEL MOIST AIR...LEADING TO THE POTENTIAL STRATUS LOWERING INTO
IFR LEVELS. WITH DIURNAL WARMING...CIGS SHOULD LIFT MVFR BY ARND
14Z. HIGH PRESSURE BUILDING OVER THE CENTRAL PLAINS AND A
DEEPENING SFC LOW OVER MICHIGAN AND THE CENTRAL GREAT LAKES WILL
BRING STRENGTHENING NW WINDS THROUGH THE DAY TOMORROW...GUSTING TO
20-25KT FROM LATE MORNING THROUGH LATE AFTERNOON. AS THE HIGH
SPREADS EAST ACROSS THE MIDDLE MISSISSIPPI VALLEY LATE TOMORROW
AFTERNOON AND EARLY TOMORROW EVENING...THE NWLY WINDS SHOULD LOOSE
THE GUSTINESS AND WEAKEN.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH IN SHRA CHANCES EARLY THIS EVENING...LOW IN TIMING AND
DURATION OF IMPACTS AT TERMINALS.
* MEDIUM ON TIMING OF PCPN WITH THE COLD FRONT OVERNIGHT.
* MEDIUM ON AT MVFR CIGS BEHIND THE FRONT LATE TONIGHT...LOW TO
MEDIUM ON IFR CIGS EARLY TOMORROW MORNING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. BREEZY NORTH TO NORTHWEST WINDS.
WEDNESDAY...VFR. NORTHWEST WINDS WITH POSSIBLE SHIFT TO NORTHEAST
WITH LAKE BREEZE.
THURSDAY...VFR. NORTH TO NORTHEAST WINDS.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN NORTHEAST WITH LAKE BREEZE IN
THE AFTERNOON.
SATURDAY AND SUNDAY...VFR. CHANCE TSRA. SOUTH TO SOUTHEAST WINDS.
KMD
&&
.MARINE...
403 PM CDT
THE HIGHER WINDS AND WAVES FROM EARLIER THIS MORNING HAVE SINCE
DIMINISHED/SUBSIDED TODAY AS A WEAKER SURFACE GRADIENT HAS SETTLED
IN...BETWEEN WEAKENING LOW PRESSURE WEST OF THE LAKE AND A
NORTHWARD MOVING LOW PRESSURE OVER THE OHIO VALLEY. THE GENERALLY
LIGHTER WINDS CURRENTLY OVER THE LAKE WILL OBSERVE AN INCREASING
TREND THIS EVENING INTO TONIGHT AS THE OHIO VALLEY LOW DEEPENS
WHILE LIFTING THROUGH THE EASTERN GREAT LAKES...WITH NORTHERLY TO
30 KT WINDS LIKELY BY LATE TONIGHT AND EARLY TUESDAY MORNING.
LATEST TRENDS HAVE SHOWN THAT NORTHERLY GALES WILL BE POSSIBLE
TUESDAY MORNING INTO TUESDAY AFTERNOON MAINLY FOR THE NORTHERN
HALF OF THE LAKE...INSTEAD OF THE PREVIOUSLY MENTIONED OCCASIONAL
GALE FORCE GUSTS. WITH THIS POSSIBILITY...HAVE ISSUED A GALE WATCH
FOR THE NORTH HALF THIS AFTERNOON FOR THIS PERIOD. WILL NEED TO
CONTINUE TO MONITOR LATER TRENDS FOR THIS INCREASED POSSIBILITY OF
GALES. THESE NORTHERLY WINDS WILL ALLOW WAVES TO BUILD DOWN THE
LENGTH OF THE LAKE...WITH WINDS AND WAVES HAZARDOUS FOR SMALL
CRAFT LIKELY TUESDAY INTO TUESDAY NIGHT AND WEDNESDAY MORNING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...9 AM TUESDAY TO 4 AM
WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...9 AM TUESDAY TO 10 AM
WEDNESDAY.
LM...GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...7 AM
TUESDAY TO 3 PM TUESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 4
AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 10
AM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
406 PM CDT MON AUG 11 2014
.DISCUSSION...
257 PM CDT
NEAR TERM FORECAST FOCUS DEALS SHOWER/THUNDERSTORM COVERAGE THROUGH
THIS EVENING...AND ADDITIONAL SHOWER CHANCES THROUGH AT LEAST
TUESDAY MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA.
EARLY AFTERNOON SURFACE ANALYSIS DEPICTS TWO SEPARATE AREAS OF LOW
PRESSURE...ONE OVER CENTRAL WISCONSIN AND THE OTHER ACROSS WESTERN
OHIO. BOTH OF THESE SURFACE LOWS WERE ASSOCIATED WITH FAIRLY STOUT
MID-LEVEL SHORT WAVES WHICH WERE ALSO RESPONSIBLE FOR A LARGE AREA
OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WI ACROSS LAKE MICHIGAN
TO THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION THIS AFTERNOON. FOR
OUR LOCAL AREA...THE STRONG SHORT WAVE TROUGH SEEN IN GOES VAPOR
IMAGERY OVER MINNESOTA WILL BE THE MAIN DRIVER IN OUR WEATHER AND
PRECIP TRENDS OVER THE NEXT 18 HOURS OR SO...AS IT CONTINUES TO DIG
SOUTHEAST ACROSS NORTHERN IL THROUGH TUESDAY MORNING. ALONG WITH ITS
SURFACE REFLECTION OVER WI...A COLD FRONT EXTENDING ALONG THE
MISSISSIPPI RIVER WILL PUSH SOUTHEAST THROUGH THIS EVENING...AND
WILL BE THE FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS. WHILE SURFACE
WINDS WERE ALREADY WEST-NORTHWEST AHEAD OF THE FRONT ITSELF...THUS
REDUCING CONVERGENCE ALONG THE BOUNDARY...STEEP LOW LEVEL LAPSE
RATES AND RAP MESOANALYSIS MLCAPES OF 500-1000 J/KG SHOULD BE ENOUGH
TO SUSTAIN SHOWERS/THUNDERSTORMS AHEAD OF THE FRONT THROUGH EARLY
EVENING. IN ADDITION...A FEW SHOWERS HAD DEVELOPED ALONG THE LAKE
BREEZE FROM SOUTHEAST WI INTO NORTHEAST IL...AND THESE SHOWERS AND
ISOLATED THUNDERSTORMS MAY ALSO FESTER A BIT AHEAD OF THE FRONT. ANY
OF THE STRONGER STORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS...AND
PERHAPS SOME BRIEF GUSTY WINDS WITH STORMS ALONG THE FRONT DUE TO
THE STEEP LOW LEVEL LAPSE RATES.
THE STRONG MINNESOTA SHORT WAVE WILL AMPLIFY/DEEPEN AN UPPER TROUGH
OVER THE WESTERN LAKES TONIGHT...WITH THE SURFACE LOWS CONSOLIDATING
AND DEEPENING OVER LOWER MICHIGAN. A FEW SHOWERS MAY LINGER OVER
NORTHEASTERN PARTS OF THE CWA AND SOUTHERN LAKE MICHIGAN TUESDAY
MORNING AS THE MAIN VORT MOVES THROUGH...BEFORE SUBSIDENCE INDICATED
BY 40 METER H5 HEIGHT RISES SPREADS IN DURING THE AFTERNOON. NORTH
WINDS STRENGTHENING BEHIND THE DEEPENING LOW WILL EVENTUALLY PULL
COOLER AND DRIER AIR INTO THE REGION TUESDAY AFTERNOON/NIGHT. AFTER
TEMPS REACHING THE LOW 80S TODAY (WHERE CLOUDS DID NOT PREVENT
IT)... COOLER 70S EXPECTED FOR HIGHS TUESDAY...AND SOME LOW 50S FOR
LOWS TUESDAY NIGHT!
GUIDANCE INDICATES ANOTHER WEAKER SHORT-WAVE DROPPING SOUTHEAST
ACROSS THE WESTERN LAKES WEDNESDAY...WITH A WEAK SURFACE WAVE AND
TROUGH PUSHING SOUTH ACROSS THE REGION DURING THE AFTERNOON. SOME
MODELS ARE TRYING TO SQUEEZE OUT A LITTLE PATCHY LIGHT QPF HINTING
AT SOME SHOWERS ALONG/AHEAD OF THE TROUGH DURING THE AFTERNOON...
THOUGH MOST OF THIS IS ACROSS WI/NORTHEAST IA AND HAVE LOW ENOUGH
CONFIDENCE IN IT IMPACTING THE FORECAST AREA TO LEAVE IT OUT OF THE
FORECAST AT THIS TIME. SIMILAR POTENTIAL FOR THURSDAY AFTERNOON
FARTHER SOUTH DEPENDING UPON WHERE THE TROUGH IS BY THEN. OTHERWISE
HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY NIGHT AND THURSDAY
WITH LIGHTER WINDS AND A MODERATION IN TEMPS BACK TO THE 75-80
DEGREE RANGE THURSDAY AND AROUND 80 FRIDAY WITH ATTENDANT LAKE
BREEZES. THE HIGH THEN DRIFTS OFF TO THE EAST FRIDAY NIGHT AND
SATURDAY...WITH AN EVENTUAL RETURN OF WARM/MOIST ADVECTION FLOW INTO
THE WEEKEND AND EARLY NEXT WEEK. IN THE EXTENDED RANGE...GEM...GFS
AND ECMWF ALL BRING SOME PRECIP POTENTIAL BACK TO THE AREA BY FRIDAY
NIGHT...THOUGH THERE ARE SOME TIMING DIFFERENCES BETWEEN THE GLOBAL
GUIDANCE BY DAYS 6-7. THUS HAVE MAINTAINED BLENDED GUIDANCE APPROACH
WITH GENERALLY LOW-CHANCE POPS AND TEMPS WARMING BACK INTO THE
LOW-MID 80S THROUGH THE WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SHRA/TSRA CHANCES LATE THIS AFTERNOON ALONG A LAKE BREEZE AND
THEN AN INITIAL COLD FRONT/WIND SHIFT BOUNDARY.
* SECOND AND BETTER CHANCE FOR SHRA/TSRA WITH AN UPPER LEVEL
DISTURBANCE THIS EVENING. ANOTHER CHANCE WITH A COLD FRONT
OVERNIGHT.
* MVFR/IFR CIGS BEHIND THE COLD FRONT EARLY TUESDAY MORNING.
KREIN
//DISCUSSION...UPDATED 18Z...
A COMPLEX UPPER LEVEL PATTERN IS LARGELY RESPONSIBLE FOR SHAPING
THE WEATHER OVER THE AREA THROUGH THE NEXT 24-30 HRS.
MEANWHILE...AT THE SFC...A WEAK PRESSURE GRADIENT IS IN PLACE
AHEAD OF AN APPROACHING COLD FRONT...WHICH MAY HELP INDUCE A LAKE
BREEZE THIS AFTERNOON. HOWEVER...INITIALLY...HAVE DELAYED THE CIGS
IMPROVING FROM MVFR TO VFR BASED ON LATEST SATELLITE TRENDS. THE
BACK EDGE OF THE THICKER LOWER CLOUD IS SLOWING AS CU DEVELOPMENT
BEGINS TO FILL IN THE CLEAR SLOT BETWEEN THE APPROACHING COLD
FRONT FROM THE NORTHWEST AND THE EXITING MID LEVEL IMPULSE OFF TO
THE NORTHEAST. BY LATE THIS AFTERNOON...THE CLEARING SKIES AND
WEAK GRADIENT SHOULD ALLOW THE LAKE BREEZE TO FORM...TURNING WINDS
TO MORE NELY AT THE CHICAGO AREA TERMINALS. WITH A VERY MOIST
AIRMASS IN PLACE...THE LAKE BREEZE BOUNDARY SHOULD BE THE FOCUS
FOR ADDITIONAL SCT SHOWERS AND POSSIBLE AN ISOLATED THUNDERSTORM.
THE WEAK COLD FRONT IS STILL EXPECTED TO PUSH ACROSS THE AREA LATE
THIS EVENING...TURNING WINDS MORE NWLY. BY THE EARLY MORNING HOURS
TUESDAY MORNING...DRIER AIR ALOFT IS EXPECTED TO OVERSPREAD THE LOW
LEVEL MOIST AIR...LEADING TO THE POTENTIAL STRATUS LOWERING INTO
IFR LEVELS. WITH DIURNAL WARMING...CIGS SHOULD LIFT MVFR BY ARND
14Z. HIGH PRESSURE BUILDING OVER THE CENTRAL PLAINS AND A
DEEPENING SFC LOW OVER MICHIGAN AND THE CENTRAL GREAT LAKES WILL
BRING STRENGTHENING NW WINDS THROUGH THE DAY TOMORROW...GUSTING TO
20-25KT FROM LATE MORNING THROUGH LATE AFTERNOON. AS THE HIGH
SPREADS EAST ACROSS THE MIDDLE MISSISSIPPI VALLEY LATE TOMORROW
AFTERNOON AND EARLY TOMORROW EVENING...THE NWLY WINDS SHOULD LOOSE
THE GUSTINESS AND WEAKEN.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH THAT WINDS REMAIN UNDER 10 KT TODAY.
* MEDIUM IN SHRA CHANCES LATE THIS AFTERNOON...LOW IN ANY TSRA
WITH THE LAKE BREEZE BOUNDARY...WHERE BETTER CHANCES EXIST
NORTH OF ORD.
* MEDIUM TO HIGH ON SHRA CHANCES THIS EVENING WITH UPPER LEVEL
DISTURBANCE AND MEDIUM ON TIMING OF THE COLD FRONT.
* MEDIUM ON AT MVFR CIGS BEHIND THE FRONT LATE TONIGHT...LOW TO
MEDIUM ON IFR CIGS EARLY TOMORROW MORNING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. BREEZY NORTH TO NORTHWEST WINDS.
WEDNESDAY...VFR. NORTHWEST WINDS WITH POSSIBLE SHIFT TO NORTHEAST
WITH LAKE BREEZE.
THURSDAY...VFR. NORTH TO NORTHEAST WINDS.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN NORTHEAST WITH LAKE BREEZE IN
THE AFTERNOON.
SATURDAY AND SUNDAY...VFR. CHANCE TSRA. SOUTH TO SOUTHEAST WINDS.
KMD
&&
.MARINE...
403 PM CDT
THE HIGHER WINDS AND WAVES FROM EARLIER THIS MORNING HAVE SINCE
DIMINISHED/SUBSIDED TODAY AS A WEAKER SURFACE GRADIENT HAS SETTLED
IN...BETWEEN WEAKENING LOW PRESSURE WEST OF THE LAKE AND A
NORTHWARD MOVING LOW PRESSURE OVER THE OHIO VALLEY. THE GENERALLY
LIGHTER WINDS CURRENTLY OVER THE LAKE WILL OBSERVE AN INCREASING
TREND THIS EVENING INTO TONIGHT AS THE OHIO VALLEY LOW DEEPENS
WHILE LIFTING THROUGH THE EASTERN GREAT LAKES...WITH NORTHERLY TO
30 KT WINDS LIKELY BY LATE TONIGHT AND EARLY TUESDAY MORNING.
LATEST TRENDS HAVE SHOWN THAT NORTHERLY GALES WILL BE POSSIBLE
TUESDAY MORNING INTO TUESDAY AFTERNOON MAINLY FOR THE NORTHERN
HALF OF THE LAKE...INSTEAD OF THE PREVIOUSLY MENTIONED OCCASIONAL
GALE FORCE GUSTS. WITH THIS POSSIBILITY...HAVE ISSUED A GALE WATCH
FOR THE NORTH HALF THIS AFTERNOON FOR THIS PERIOD. WILL NEED TO
CONTINUE TO MONITOR LATER TRENDS FOR THIS INCREASED POSSIBILITY OF
GALES. THESE NORTHERLY WINDS WILL ALLOW WAVES TO BUILD DOWN THE
LENGTH OF THE LAKE...WITH WINDS AND WAVES HAZARDOUS FOR SMALL
CRAFT LIKELY TUESDAY INTO TUESDAY NIGHT AND WEDNESDAY MORNING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...9 AM TUESDAY TO 4 AM
WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...9 AM TUESDAY TO 10 AM
WEDNESDAY.
LM...GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...7 AM
TUESDAY TO 3 PM TUESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 4
AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 10
AM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
313 PM CDT MON AUG 11 2014
.DISCUSSION...
257 PM CDT
NEAR TERM FORECAST FOCUS DEALS SHOWER/THUNDERSTORM COVERAGE THROUGH
THIS EVENING...AND ADDITIONAL SHOWER CHANCES THROUGH AT LEAST
TUESDAY MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA.
EARLY AFTERNOON SURFACE ANALYSIS DEPICTS TWO SEPARATE AREAS OF LOW
PRESSURE...ONE OVER CENTRAL WISCONSIN AND THE OTHER ACROSS WESTERN
OHIO. BOTH OF THESE SURFACE LOWS WERE ASSOCIATED WITH FAIRLY STOUT
MID-LEVEL SHORT WAVES WHICH WERE ALSO RESPONSIBLE FOR A LARGE AREA
OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WI ACROSS LAKE MICHIGAN
TO THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION THIS AFTERNOON. FOR
OUR LOCAL AREA...THE STRONG SHORT WAVE TROUGH SEEN IN GOES VAPOR
IMAGERY OVER MINNESOTA WILL BE THE MAIN DRIVER IN OUR WEATHER AND
PRECIP TRENDS OVER THE NEXT 18 HOURS OR SO...AS IT CONTINUES TO DIG
SOUTHEAST ACROSS NORTHERN IL THROUGH TUESDAY MORNING. ALONG WITH ITS
SURFACE REFLECTION OVER WI...A COLD FRONT EXTENDING ALONG THE
MISSISSIPPI RIVER WILL PUSH SOUTHEAST THROUGH THIS EVENING...AND
WILL BE THE FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS. WHILE SURFACE
WINDS WERE ALREADY WEST-NORTHWEST AHEAD OF THE FRONT ITSELF...THUS
REDUCING CONVERGENCE ALONG THE BOUNDARY...STEEP LOW LEVEL LAPSE
RATES AND RAP MESOANALYSIS MLCAPES OF 500-1000 J/KG SHOULD BE ENOUGH
TO SUSTAIN SHOWERS/THUNDERSTORMS AHEAD OF THE FRONT THROUGH EARLY
EVENING. IN ADDITION...A FEW SHOWERS HAD DEVELOPED ALONG THE LAKE
BREEZE FROM SOUTHEAST WI INTO NORTHEAST IL...AND THESE SHOWERS AND
ISOLATED THUNDERSTORMS MAY ALSO FESTER A BIT AHEAD OF THE FRONT. ANY
OF THE STRONGER STORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS...AND
PERHAPS SOME BRIEF GUSTY WINDS WITH STORMS ALONG THE FRONT DUE TO
THE STEEP LOW LEVEL LAPSE RATES.
THE STRONG MINNESOTA SHORT WAVE WILL AMPLIFY/DEEPEN AN UPPER TROUGH
OVER THE WESTERN LAKES TONIGHT...WITH THE SURFACE LOWS CONSOLIDATING
AND DEEPENING OVER LOWER MICHIGAN. A FEW SHOWERS MAY LINGER OVER
NORTHEASTERN PARTS OF THE CWA AND SOUTHERN LAKE MICHIGAN TUESDAY
MORNING AS THE MAIN VORT MOVES THROUGH...BEFORE SUBSIDENCE INDICATED
BY 40 METER H5 HEIGHT RISES SPREADS IN DURING THE AFTERNOON. NORTH
WINDS STRENGTHENING BEHIND THE DEEPENING LOW WILL EVENTUALLY PULL
COOLER AND DRIER AIR INTO THE REGION TUESDAY AFTERNOON/NIGHT. AFTER
TEMPS REACHING THE LOW 80S TODAY (WHERE CLOUDS DID NOT PREVENT
IT)... COOLER 70S EXPECTED FOR HIGHS TUESDAY...AND SOME LOW 50S FOR
LOWS TUESDAY NIGHT!
GUIDANCE INDICATES ANOTHER WEAKER SHORT-WAVE DROPPING SOUTHEAST
ACROSS THE WESTERN LAKES WEDNESDAY...WITH A WEAK SURFACE WAVE AND
TROUGH PUSHING SOUTH ACROSS THE REGION DURING THE AFTERNOON. SOME
MODELS ARE TRYING TO SQUEEZE OUT A LITTLE PATCHY LIGHT QPF HINTING
AT SOME SHOWERS ALONG/AHEAD OF THE TROUGH DURING THE AFTERNOON...
THOUGH MOST OF THIS IS ACROSS WI/NORTHEAST IA AND HAVE LOW ENOUGH
CONFIDENCE IN IT IMPACTING THE FORECAST AREA TO LEAVE IT OUT OF THE
FORECAST AT THIS TIME. SIMILAR POTENTIAL FOR THURSDAY AFTERNOON
FARTHER SOUTH DEPENDING UPON WHERE THE TROUGH IS BY THEN. OTHERWISE
HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY NIGHT AND THURSDAY
WITH LIGHTER WINDS AND A MODERATION IN TEMPS BACK TO THE 75-80
DEGREE RANGE THURSDAY AND AROUND 80 FRIDAY WITH ATTENDANT LAKE
BREEZES. THE HIGH THEN DRIFTS OFF TO THE EAST FRIDAY NIGHT AND
SATURDAY...WITH AN EVENTUAL RETURN OF WARM/MOIST ADVECTION FLOW INTO
THE WEEKEND AND EARLY NEXT WEEK. IN THE EXTENDED RANGE...GEM...GFS
AND ECMWF ALL BRING SOME PRECIP POTENTIAL BACK TO THE AREA BY FRIDAY
NIGHT...THOUGH THERE ARE SOME TIMING DIFFERENCES BETWEEN THE GLOBAL
GUIDANCE BY DAYS 6-7. THUS HAVE MAINTAINED BLENDED GUIDANCE APPROACH
WITH GENERALLY LOW-CHANCE POPS AND TEMPS WARMING BACK INTO THE
LOW-MID 80S THROUGH THE WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SHRA/TSRA CHANCES LATE THIS AFTERNOON ALONG A LAKE BREEZE AND
THEN AN INITIAL COLD FRONT/WIND SHIFT BOUNDARY.
* SECOND AND BETTER CHANCE FOR SHRA/TSRA WITH AN UPPER LEVEL
DISTURBANCE THIS EVENING. ANOTHER CHANCE WITH A COLD FRONT
OVERNIGHT.
* MVFR/IFR CIGS BEHIND THE COLD FRONT EARLY TUESDAY MORNING.
KREIN
//DISCUSSION...UPDATED 18Z...
A COMPLEX UPPER LEVEL PATTERN IS LARGELY RESPONSIBLE FOR SHAPING
THE WEATHER OVER THE AREA THROUGH THE NEXT 24-30 HRS.
MEANWHILE...AT THE SFC...A WEAK PRESSURE GRADIENT IS IN PLACE
AHEAD OF AN APPROACHING COLD FRONT...WHICH MAY HELP INDUCE A LAKE
BREEZE THIS AFTERNOON. HOWEVER...INITIALLY...HAVE DELAYED THE CIGS
IMPROVING FROM MVFR TO VFR BASED ON LATEST SATELLITE TRENDS. THE
BACK EDGE OF THE THICKER LOWER CLOUD IS SLOWING AS CU DEVELOPMENT
BEGINS TO FILL IN THE CLEAR SLOT BETWEEN THE APPROACHING COLD
FRONT FROM THE NORTHWEST AND THE EXITING MID LEVEL IMPULSE OFF TO
THE NORTHEAST. BY LATE THIS AFTERNOON...THE CLEARING SKIES AND
WEAK GRADIENT SHOULD ALLOW THE LAKE BREEZE TO FORM...TURNING WINDS
TO MORE NELY AT THE CHICAGO AREA TERMINALS. WITH A VERY MOIST
AIRMASS IN PLACE...THE LAKE BREEZE BOUNDARY SHOULD BE THE FOCUS
FOR ADDITIONAL SCT SHOWERS AND POSSIBLE AN ISOLATED THUNDERSTORM.
THE WEAK COLD FRONT IS STILL EXPECTED TO PUSH ACROSS THE AREA LATE
THIS EVENING...TURNING WINDS MORE NWLY. BY THE EARLY MORNING HOURS
TUESDAY MORNING...DRIER AIR ALOFT IS EXPECTED TO OVERSPREAD THE LOW
LEVEL MOIST AIR...LEADING TO THE POTENTIAL STRATUS LOWERING INTO
IFR LEVELS. WITH DIURNAL WARMING...CIGS SHOULD LIFT MVFR BY ARND
14Z. HIGH PRESSURE BUILDING OVER THE CENTRAL PLAINS AND A
DEEPENING SFC LOW OVER MICHIGAN AND THE CENTRAL GREAT LAKES WILL
BRING STRENGTHENING NW WINDS THROUGH THE DAY TOMORROW...GUSTING TO
20-25KT FROM LATE MORNING THROUGH LATE AFTERNOON. AS THE HIGH
SPREADS EAST ACROSS THE MIDDLE MISSISSIPPI VALLEY LATE TOMORROW
AFTERNOON AND EARLY TOMORROW EVENING...THE NWLY WINDS SHOULD LOOSE
THE GUSTINESS AND WEAKEN.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH THAT WINDS REMAIN UNDER 10 KT TODAY.
* MEDIUM IN SHRA CHANCES LATE THIS AFTERNOON...LOW IN ANY TSRA
WITH THE LAKE BREEZE BOUNDARY...WHERE BETTER CHANCES EXIST
NORTH OF ORD.
* MEDIUM TO HIGH ON SHRA CHANCES THIS EVENING WITH UPPER LEVEL
DISTURBANCE AND MEDIUM ON TIMING OF THE COLD FRONT.
* MEDIUM ON AT MVFR CIGS BEHIND THE FRONT LATE TONIGHT...LOW TO
MEDIUM ON IFR CIGS EARLY TOMORROW MORNING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. BREEZY NORTH TO NORTHWEST WINDS.
WEDNESDAY...VFR. NORTHWEST WINDS WITH POSSIBLE SHIFT TO NORTHEAST
WITH LAKE BREEZE.
THURSDAY...VFR. NORTH TO NORTHEAST WINDS.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN NORTHEAST WITH LAKE BREEZE IN
THE AFTERNOON.
SATURDAY AND SUNDAY...VFR. CHANCE TSRA. SOUTH TO SOUTHEAST WINDS.
KMD
&&
.MARINE...
314 AM CDT
AFTER FAIRLY QUIET CONDITIONS ON THE LAKE THROUGH EARLY
AFTERNOON...A MODEST COLD FRONT WILL MOVE OVER THE LAKE LATE TODAY
BRINGING A PERIOD OF NEAR GALE FORCE WINDS INTO TUESDAY.
LOW PRESSURE OVER THE OHIO VALLEY WILL DEEPEN AND PUSH NORTHEAST
TOWARD LAKE HURON BY DAYBREAK TUESDAY WHILE HIGH PRESSURE BUILDS
SOUTH INTO THE UPPER MIDWEST AND PLAINS STATES. AS THIS OCCURS A
COLD FRONT PASSES OVER THE LAKE BRINGING A PERIOD OF GUSTY
NORTHWEST TO NORTH WINDS. IT APPEARS THAT THE STRONGEST GRADIENT
WILL BE ON THE NORTH HALF OF THE LAKE WHERE THERE IS A BETTER
CHANCE FOR NEAR GALE FORCE....THOUGH SOLID WINDS TO 30 KT CAN BE
EXPECTED. WITH THE EXTENDED PERIOD OF NNW WINDS...WAVES WILL BUILD
ESPECIALLY ACROSS THE SOUTHERN HALF OF THE LAKE. SMALL CRAFT
ADVISORY CONDITIONS LOOK FAIRLY LIKELY FOR THE NEARSHORE WATERS...ESPECIALLY
DUE TO THE BUILDING WAVES...WITH AT LEAST A PERIOD OF 20-25 KT
POSSIBLE.
HIGH PRESSURE WILL BEGIN TO NOSE INTO THE GREAT LAKES REGION ON
WEDNESDAY AND BRING THE RETURN TO LAKE BREEZE INFLUENCE FOR THE
LATTER HALF OF THE WEEK.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 10
AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 4
AM WEDNESDAY.
GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...7 AM
TUESDAY TO 3 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
258 PM CDT MON AUG 11 2014
.DISCUSSION...
257 PM CDT
NEAR TERM FORECAST FOCUS DEALS SHOWER/THUNDERSTORM COVERAGE THROUGH
THIS EVENING...AND ADDITIONAL SHOWER CHANCES THROUGH AT LEAST
TUESDAY MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA.
EARLY AFTERNOON SURFACE ANALYSIS DEPICTS TWO SEPARATE AREAS OF LOW
PRESSURE...ONE OVER CENTRAL WISCONSIN AND THE OTHER ACROSS WESTERN
OHIO. BOTH OF THESE SURFACE LOWS WERE ASSOCIATED WITH FAIRLY STOUT
MID-LEVEL SHORT WAVES WHICH WERE ALSO RESPONSIBLE FOR A LARGE AREA
OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WI ACROSS LAKE MICHIGAN
TO THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION THIS AFTERNOON. FOR
OUR LOCAL AREA...THE STRONG SHORT WAVE TROUGH SEEN IN GOES VAPOR
IMAGERY OVER MINNESOTA WILL BE THE MAIN DRIVER IN OUR WEATHER AND
PRECIP TRENDS OVER THE NEXT 18 HOURS OR SO...AS IT CONTINUES TO DIG
SOUTHEAST ACROSS NORTHERN IL THROUGH TUESDAY MORNING. ALONG WITH ITS
SURFACE REFLECTION OVER WI...A COLD FRONT EXTENDING ALONG THE
MISSISSIPPI RIVER WILL PUSH SOUTHEAST THROUGH THIS EVENING...AND
WILL BE THE FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS. WHILE SURFACE
WINDS WERE ALREADY WEST-NORTHWEST AHEAD OF THE FRONT ITSELF...THUS
REDUCING CONVERGENCE ALONG THE BOUNDARY...STEEP LOW LEVEL LAPSE
RATES AND RAP MESOANALYSIS MLCAPES OF 500-1000 J/KG SHOULD BE ENOUGH
TO SUSTAIN SHOWERS/THUNDERSTORMS AHEAD OF THE FRONT THROUGH EARLY
EVENING. IN ADDITION...A FEW SHOWERS HAD DEVELOPED ALONG THE LAKE
BREEZE FROM SOUTHEAST WI INTO NORTHEAST IL...AND THESE SHOWERS AND
ISOLATED THUNDERSTORMS MAY ALSO FESTER A BIT AHEAD OF THE FRONT. ANY
OF THE STRONGER STORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS...AND
PERHAPS SOME BRIEF GUSTY WINDS WITH STORMS ALONG THE FRONT DUE TO
THE STEEP LOW LEVEL LAPSE RATES.
THE STRONG MINNESOTA SHORT WAVE WILL AMPLIFY/DEEPEN AN UPPER TROUGH
OVER THE WESTERN LAKES TONIGHT...WITH THE SURFACE LOWS CONSOLIDATING
AND DEEPENING OVER LOWER MICHIGAN. A FEW SHOWERS MAY LINGER OVER
NORTHEASTERN PARTS OF THE CWA AND SOUTHERN LAKE MICHIGAN TUESDAY
MORNING AS THE MAIN VORT MOVES THROUGH...BEFORE SUBSIDENCE INDICATED
BY 40 METER H5 HEIGHT RISES SPREADS IN DURING THE AFTERNOON. NORTH
WINDS STRENGTHENING BEHIND THE DEEPENING LOW WILL EVENTUALLY PULL
COOLER AND DRIER AIR INTO THE REGION TUESDAY AFTERNOON/NIGHT. AFTER
TEMPS REACHING THE LOW 80S TODAY (WHERE CLOUDS DID NOT PREVENT
IT)... COOLER 70S EXPECTED FOR HIGHS TUESDAY...AND SOME LOW 50S FOR
LOWS TUESDAY NIGHT!
GUIDANCE INDICATES ANOTHER WEAKER SHORT-WAVE DROPPING SOUTHEAST
ACROSS THE WESTERN LAKES WEDNESDAY...WITH A WEAK SURFACE WAVE AND
TROUGH PUSHING SOUTH ACROSS THE REGION DURING THE AFTERNOON. SOME
MODELS ARE TRYING TO SQUEEZE OUT A LITTLE PATCHY LIGHT QPF HINTING
AT SOME SHOWERS ALONG/AHEAD OF THE TROUGH DURING THE AFTERNOON...
THOUGH MOST OF THIS IS ACROSS WI/NORTHEAST IA AND HAVE LOW ENOUGH
CONFIDENCE IN IT IMPACTING THE FORECAST AREA TO LEAVE IT OUT OF THE
FORECAST AT THIS TIME. SIMILAR POTENTIAL FOR THURSDAY AFTERNOON
FARTHER SOUTH DEPENDING UPON WHERE THE TROUGH IS BY THEN. OTHERWISE
HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY NIGHT AND THURSDAY
WITH LIGHTER WINDS AND A MODERATION IN TEMPS BACK TO THE 75-80
DEGREE RANGE THURSDAY AND AROUND 80 FRIDAY WITH ATTENDANT LAKE
BREEZES. THE HIGH THEN DRIFTS OFF TO THE EAST FRIDAY NIGHT AND
SATURDAY...WITH AN EVENTUAL RETURN OF WARM/MOIST ADVECTION FLOW INTO
THE WEEKEND AND EARLY NEXT WEEK. IN THE EXTENDED RANGE...GEM...GFS
AND ECMWF ALL BRING SOME PRECIP POTENTIAL BACK TO THE AREA BY FRIDAY
NIGHT...THOUGH THERE ARE SOME TIMING DIFFERENCES BETWEEN THE GLOBAL
GUIDANCE BY DAYS 6-7. THUS HAVE MAINTAINED BLENDED GUIDANCE APPROACH
WITH GENERALLY LOW-CHANCE POPS AND TEMPS WARMING BACK INTO THE
LOW-MID 80S THROUGH THE WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CIGS GRADUALLY IMPROVING FROM MVFR TO VFR BY EARLY AFTERNOON.
* SHRA/TSRA CHANCES LATE THIS AFTERNOON ALONG A LAKE BREEZE AND
THEN AN INITIAL COLD FRONT/WIND SHIFT BOUNDARY.
* SECOND AND BETTER CHANCE FOR SHRA/TSRA WITH AN UPPER LEVEL
DISTURBANCE THIS EVENING. ANOTHER CHANCE WITH A COLD FRONT
OVERNIGHT.
* MVFR/IFR CIGS BEHIND THE COLD FRONT EARLY TUESDAY MORNING.
KREIN
//DISCUSSION...UPDATED 18Z...
A COMPLEX UPPER LEVEL PATTERN IS LARGELY RESPONSIBLE FOR SHAPING
THE WEATHER OVER THE AREA THROUGH THE NEXT 24-30 HRS.
MEANWHILE...AT THE SFC...A WEAK PRESSURE GRADIENT IS IN PLACE
AHEAD OF AN APPROACHING COLD FRONT...WHICH MAY HELP INDUCE A LAKE
BREEZE THIS AFTERNOON. HOWEVER...INITIALLY...HAVE DELAYED THE CIGS
IMPROVING FROM MVFR TO VFR BASED ON LATEST SATELLITE TRENDS. THE
BACK EDGE OF THE THICKER LOWER CLOUD IS SLOWING AS CU DEVELOPMENT
BEGINS TO FILL IN THE CLEAR SLOT BETWEEN THE APPROACHING COLD
FRONT FROM THE NORTHWEST AND THE EXITING MID LEVEL IMPULSE OFF TO
THE NORTHEAST. BY LATE THIS AFTERNOON...THE CLEARING SKIES AND
WEAK GRADIENT SHOULD ALLOW THE LAKE BREEZE TO FORM...TURNING WINDS
TO MORE NELY AT THE CHICAGO AREA TERMINALS. WITH A VERY MOIST
AIRMASS IN PLACE...THE LAKE BREEZE BOUNDARY SHOULD BE THE FOCUS
FOR ADDITIONAL SCT SHOWERS AND POSSIBLE AN ISOLATED THUNDERSTORM.
THE WEAK COLD FRONT IS STILL EXPECTED TO PUSH ACROSS THE AREA LATE
THIS EVENING...TURNING WINDS MORE NWLY. BY THE EARLY MORNING HOURS
TUESDAY MORNING...DRIER AIR ALOFT IS EXPECTED TO OVERSPREAD THE LOW
LEVEL MOIST AIR...LEADING TO THE POTENTIAL STRATUS LOWERING INTO
IFR LEVELS. WITH DIURNAL WARMING...CIGS SHOULD LIFT MVFR BY ARND
14Z. HIGH PRESSURE BUILDING OVER THE CENTRAL PLAINS AND A
DEEPENING SFC LOW OVER MICHIGAN AND THE CENTRAL GREAT LAKES WILL
BRING STRENGTHENING NW WINDS THROUGH THE DAY TOMORROW...GUSTING TO
20-25KT FROM LATE MORNING THROUGH LATE AFTERNOON. AS THE HIGH
SPREADS EAST ACROSS THE MIDDLE MISSISSIPPI VALLEY LATE TOMORROW
AFTERNOON AND EARLY TOMORROW EVENING...THE NWLY WINDS SHOULD LOOSE
THE GUSTINESS AND WEAKEN.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH THAT WINDS REMAIN UNDER 10 KT TODAY.
* MEDIUM ON TIMING OF CIGS LIFTING THIS AFTERNOON.
* MEDIUM IN SHRA CHANCES LATE THIS AFTERNOON...LOW IN ANY TSRA
WITH THE LAKE BREEZE BOUNDARY...WHERE BETTER CHANCES EXIST
NORTH OF ORD.
* MEDIUM TO HIGH ON SHRA CHANCES THIS EVENING WITH UPPER LEVEL
DISTURBANCE AND MEDIUM ON TIMING OF THE COLD FRONT OVERNIGHT
TONIGHT.
* MEDIUM ON AT MVFR CIGS BEHIND THE FRONT LATE TONIGHT...LOW TO
MEDIUM ON IFR CIGS EARLY TOMORROW MORNING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. BREEZY NORTH TO NORTHWEST WINDS.
WEDNESDAY...VFR. NORTHWEST WINDS WITH POSSIBLE SHIFT TO NORTHEAST
WITH LAKE BREEZE.
THURSDAY...VFR. NORTH TO NORTHEAST WINDS.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN NORTHEAST WITH LAKE BREEZE IN
THE AFTERNOON.
SATURDAY AND SUNDAY...VFR. CHANCE TSRA. SOUTH TO SOUTHEAST WINDS.
KMD
&&
.MARINE...
314 AM CDT
AFTER FAIRLY QUIET CONDITIONS ON THE LAKE THROUGH EARLY
AFTERNOON...A MODEST COLD FRONT WILL MOVE OVER THE LAKE LATE TODAY
BRINGING A PERIOD OF NEAR GALE FORCE WINDS INTO TUESDAY.
LOW PRESSURE OVER THE OHIO VALLEY WILL DEEPEN AND PUSH NORTHEAST
TOWARD LAKE HURON BY DAYBREAK TUESDAY WHILE HIGH PRESSURE BUILDS
SOUTH INTO THE UPPER MIDWEST AND PLAINS STATES. AS THIS OCCURS A
COLD FRONT PASSES OVER THE LAKE BRINGING A PERIOD OF GUSTY
NORTHWEST TO NORTH WINDS. IT APPEARS THAT THE STRONGEST GRADIENT
WILL BE ON THE NORTH HALF OF THE LAKE WHERE THERE IS A BETTER
CHANCE FOR NEAR GALE FORCE....THOUGH SOLID WINDS TO 30 KT CAN BE
EXPECTED. WITH THE EXTENDED PERIOD OF NNW WINDS...WAVES WILL BUILD
ESPECIALLY ACROSS THE SOUTHERN HALF OF THE LAKE. SMALL CRAFT
ADVISORY CONDITIONS LOOK FAIRLY LIKELY FOR THE NEARSHORE WATERS...ESPECIALLY
DUE TO THE BUILDING WAVES...WITH AT LEAST A PERIOD OF 20-25 KT
POSSIBLE.
HIGH PRESSURE WILL BEGIN TO NOSE INTO THE GREAT LAKES REGION ON
WEDNESDAY AND BRING THE RETURN TO LAKE BREEZE INFLUENCE FOR THE
LATTER HALF OF THE WEEK.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WATCH...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...7 AM
TUESDAY TO 3 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
117 PM CDT MON AUG 11 2014
.DISCUSSION...
1131 AM CDT
FOR MORNING UPDATE...
HAVE MADE SOME TWEAKS TO POPS/WX/SKY COVER THROUGH EARLY AFTERNOON
BASED ON CURRENT TRENDS.
INITIAL MID-LEVEL VORT MOVING EAST OF AREA LATE THIS MORNING
WHICH HAS ALLOWED PRECIP TO TAPER OFF TO JUST A FEW ISOLATED
SHOWERS MAINLY ACROSS THE ILLINOIS/INDIANA STATE LINE REGION AS OF
1130 AM CDT. GOES VISIBLE SATELLITE IMAGERY SHOWS AN AREA OF
CLEARING SKIES OVER MUCH OF WESTERN AND CENTRAL IL...WHICH WILL
WORK EAST ACROSS THE CWA OVER THE NEXT FEW HOURS. THIS SHOULD ALLOW
FOR SOME DESTABILIZATION WITHIN THE LOW LEVEL AIR MASS...WITH
WARMING TO AROUND 80 DEGREES WITH LOW-MID 60S SURFACE DEW POINT
TEMPS EXPECTED TO YIELD 500-1000 J/KG OF MLCAPE BY LATER THIS
AFTERNOON. SOME CONVECTIVE SHOWER/ISOLATED THUNDERSTORM
DEVELOPMENT IS EXPECTED AS SURFACE COLD FRONT MOVES INTO THE AREA
FROM SOUTHWEST WI/EASTERN IA AND ANOTHER MID-LEVEL SHORT WAVE DIGS
ACROSS THE AREA DURING THE LATE AFTERNOON AND EARLY EVENING HOURS.
WEAK DEEP LAYER BULK SHEAR...AND LOW LEVEL WEST-NORTHWEST AHEAD OF
THE SURFACE COLD FRONT SHOULD LIMIT OVERALL THUNDERSTORM INTENSITY
ALTHOUGH SLOW MOVING CELLS MAY STILL BE A THREAT TO PRODUCE SOME
LOCALLY HEAVY DOWNPOURS GIVEN PRECIPITABLE WATER VALUES STILL IN
THE 1.25-1.50 INCH RANGE. SHOWER/ISOLATED THUNDER POTENTIAL WILL
CONTINUE TONIGHT ESPECIALLY OVER NORTHEAST IL/LAKE
MICHIGAN/NORTHWEST INDIANA AS MID-LEVEL VORT MOVES SOUTHEAST
ACROSS THE REGION.
RATZER
//PREV DISCUSSION...
255 AM CDT
TODAY THROUGH TONIGHT...
IR IMAGERY INDICATES CONSIDERABLE CLOUDINESS ACROSS THE REGION EARLY
THIS MORNING. ANALYSIS INDICATES A MID-LVL WAVE SLIDING EAST
OVERHEAD THIS MORNING. THE COMBINATION OF THE UPPER LEVEL SYSTEM AND
CONSIDERABLE LLVL MOISTURE HAS ALLOWED AN AREA OF SHOWERS W/ISO
THUNDER THIS MORNING. THIS GENERALLY HAS BEEN FOCUSED ACROSS FAR
NORTHEAST IL. WITH THE PWAT VALUES HOVERING NEAR 1.7"...ANY SHOWER
ACTIVITY COULD EASILY PRODUCE BRIEF HEAVY DOWNPOURS. SOME OF THE
INSTANTANEOUS RATES HAVE HOVERED AROUND 4"/HR...FORTUNATELY THIS IS
ONLY LASTING FOR 10-15 MINS.
SPOTTY SHOWERS AND THUNDERSTORMS WILL CONTINUE THRU THIS MORNING AS
THE SHORTWAVE/TROUGH AXIS CONTINUES TO PIVOT EAST OVERHEAD. LLVL
MOISTURE CONVERGENCE WILL PERSIST...AND WITH THE HIGH DEW PTS/PWAT
VALUES...ANY SHOWERS COULD EASILY PRODUCE BRIEF HEAVY DOWNPOURS.
INSTABILITY WILL BE ELEVATED...SO HAVE HELD ONTO MENTION OF
THUNDERSTORMS. 850MB LOW WILL SLIGHTLY STRENGTHEN OVER THE OHIO
VALLEY AS IT ROTATES NORTHEAST ACROSS NORTHWEST OHIO THIS AFTN.
SFC WINDS WILL BE LIGHT TO VARIABLE TO START THE DAY...THEN BEGIN TO
SOLIDIFY FROM THE NORTHWEST. GIVEN THE CONSIDERABLE SOLAR
SHIELDING...EXPECT TEMPS TO STRUGGLE TO WARM TODAY. SO HAVE NUDGED
TEMPS DOWN A COUPLE OF DEGREES...INTO THE UPR 70S FOR THE NORTHEAST
CWFA AND ARND 80 IN OUR WESTERN FORECAST AREAS.
FOR THIS EVENING THE STRONGER TROUGH AXIS WILL BE APPROACHING THE
GREAT LAKES FROM THE NORTHWEST. LLVL MOISTURE WILL REMAIN ABUNDANT
OVER MUCH OF THE FORECAST AREA...SLOWLY PIVOTING TO THE EAST
OVERNIGHT INTO TUE MORNING. HAVE NUDGED POPS UP TOWARDS
LIKELY...MAINLY FOCUSED FOR THE NORTH/NORTHEAST CWFA. TEMPS ALOFT
WILL BE STEADILY COOLING...BUT EXPECT OVERNIGHT LOWS TO ONLY DROP
INTO THE LOW 60S TO MID 60S NEAR DOWNTOWN CHICAGO.
TUESDAY...
500MB VORT MAX WILL BE SLIDING SOUTHEAST ACROSS SOUTHEAST WISC
TOWARDS NORTHERN IN BY MIDDAY TUE. THIS IS SLIGHTLY FURTHER SOUTH
THEN PRIOR CYCLES...AND LOCAL ARW8KM SOLUTION INDICATES A FEW WEAKER
LOBES OF VORTICITY WILL ROTATE AROUND THE WESTERN PERIPHERY WITH
REINFORCING SLUGS OF PRECIP THRU MIDDAY TUE BEFORE DEPARTING TO THE
EAST AS ANTI-CYCLONIC FLOW STEADILY ERODES LLVL MOISTURE TUE EVE.
THERMAL TROUGH AT 850MB WILL SLOWLY SLIDE SOUTH ACROSS THE
REGION...GENERALLY BETWEEN 8-10 DEG C FOR MUCH OF THE FORECAST AREA.
THE STEADY NORTHERLY FLOW WILL LIKELY HOLD TEMPS IN THE LOW 70S FOR
MUCH OF THE CWFA. THE EXCEPTION COULD BE THE FAR WEST/SOUTHWEST
WHERE TEMPS COULD PUSH TO THE MID 70S. SFC RIDGING WILL WEAKEN THE
GRADIENT TUE NGT...WITH SKIES TRYING TO THIN. THIS WILL ALLOW TEMPS
TO RADIATE INTO THE LOW 50S...POSSIBLY UPR 40S IN THE MORE
TRADITIONAL COOL SPOTS TUE NGT. MEANWHILE AREAS ADJACENT TO LAKE
MICHIGAN WILL SEE TEMPS HOLD IN THE UPR 50S/LOW 60S.
WEDNESDAY THROUGH FRIDAY...
SFC RIDGE WILL BE IN CONTROL FOR MID-WEEK THRU FRI...LIKELY KEEPING
DRY AND PLEASANT CONDITIONS ACROSS THE REGION. LOCAL ARW8KM DOES
PAINT A WEAK LOBE OF VORTICITY TRYING TO SLIDE SOUTHEAST ACROSS THE
GREAT LAKES WED...HOWEVER FEEL MAINTAINING DRY CONDS IS THE MOST
PROBABLE OUTCOME FOR WED THRU FRI.
500MB VORT WILL BECOME QUASI-STATIONARY OVER SOUTHEAST ONTARIO WITH
HIGH AMPLITUDE RIDGING OVER THE CANADIAN ROCKIES KEEPING THE WESTERN
GREAT LAKES IN A NORTHWEST FLOW PATTERN.
TEMPS WILL GENERALLY BE IN THE UPR 70S...WITH A FEW SITES HITTING 80
OR ARND 80 BY THUR/FRI.
SATURDAY THROUGH SUNDAY...
ENSEMBLES HAVE CONTINUED MINIMAL SPREAD THRU SAT...HOWEVER BEYOND
THIS POINT THE SPREAD DRAMATICALLY INCREASES. ONE OF THE PROBLEMS
SOLUTIONS ARE STRUGGLING WITH IS TRYING TO WEAKEN THE DOWNSTREAM
BLOCK OF THE NORTH ATLANTIC...WHICH WILL HAVE AN IMPACT ON THE
TROUGH OVER SOUTHERN ONTARIO AND THE NORTHWEST FLOW FOR THE GREAT
LAKES. THERE IS SOME AGREEMENT THAT THE FLOW OVER THE GREAT
LAKES/UPPER MIDWEST WILL BEGIN TO FLATTEN AND TRANSITION TOWARDS A
SEMI-ZONAL PATTERN FOR THE WEEKEND...WHICH WILL BRING A SOMEWHAT
ACTIVE SETUP TO THE AREA. SO HAVE CHC POPS RETURNING LATE FRI THRU
SUN. TEMPS WILL BE SLOWLY RETURNING TO SEASONAL CONDITIONS OR IN THE
LOW 80S.
CONFIDENCE...MEDIUM.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CIGS GRADUALLY IMPROVING FROM MVFR TO VFR BY EARLY AFTERNOON.
* SHRA/TSRA CHANCES LATE THIS AFTERNOON ALONG A LAKE BREEZE AND
THEN AN INITIAL COLD FRONT/WIND SHIFT BOUNDARY.
* SECOND AND BETTER CHANCE FOR SHRA/TSRA WITH AN UPPER LEVEL
DISTURBANCE THIS EVENING. ANOTHER CHANCE WITH A COLD FRONT
OVERNIGHT.
* MVFR/IFR CIGS BEHIND THE COLD FRONT EARLY TUESDAY MORNING.
KREIN
//DISCUSSION...UPDATED 18Z...
A COMPLEX UPPER LEVEL PATTERN IS LARGELY RESPONSIBLE FOR SHAPING
THE WEATHER OVER THE AREA THROUGH THE NEXT 24-30 HRS.
MEANWHILE...AT THE SFC...A WEAK PRESSURE GRADIENT IS IN PLACE
AHEAD OF AN APPROACHING COLD FRONT...WHICH MAY HELP INDUCE A LAKE
BREEZE THIS AFTERNOON. HOWEVER...INITIALLY...HAVE DELAYED THE CIGS
IMPROVING FROM MVFR TO VFR BASED ON LATEST SATELLITE TRENDS. THE
BACK EDGE OF THE THICKER LOWER CLOUD IS SLOWING AS CU DEVELOPMENT
BEGINS TO FILL IN THE CLEAR SLOT BETWEEN THE APPROACHING COLD
FRONT FROM THE NORTHWEST AND THE EXITING MID LEVEL IMPULSE OFF TO
THE NORTHEAST. BY LATE THIS AFTERNOON...THE CLEARING SKIES AND
WEAK GRADIENT SHOULD ALLOW THE LAKE BREEZE TO FORM...TURNING WINDS
TO MORE NELY AT THE CHICAGO AREA TERMINALS. WITH A VERY MOIST
AIRMASS IN PLACE...THE LAKE BREEZE BOUNDARY SHOULD BE THE FOCUS
FOR ADDITIONAL SCT SHOWERS AND POSSIBLE AN ISOLATED THUNDERSTORM.
THE WEAK COLD FRONT IS STILL EXPECTED TO PUSH ACROSS THE AREA LATE
THIS EVENING...TURNING WINDS MORE NWLY. BY THE EARLY MORNING HOURS
TUESDAY MORNING...DRIER AIR ALOFT IS EXPECTED TO OVERSPREAD THE LOW
LEVEL MOIST AIR...LEADING TO THE POTENTIAL STRATUS LOWERING INTO
IFR LEVELS. WITH DIURNAL WARMING...CIGS SHOULD LIFT MVFR BY ARND
14Z. HIGH PRESSURE BUILDING OVER THE CENTRAL PLAINS AND A
DEEPENING SFC LOW OVER MICHIGAN AND THE CENTRAL GREAT LAKES WILL
BRING STRENGTHENING NW WINDS THROUGH THE DAY TOMORROW...GUSTING TO
20-25KT FROM LATE MORNING THROUGH LATE AFTERNOON. AS THE HIGH
SPREADS EAST ACROSS THE MIDDLE MISSISSIPPI VALLEY LATE TOMORROW
AFTERNOON AND EARLY TOMORROW EVENING...THE NWLY WINDS SHOULD LOOSE
THE GUSTINESS AND WEAKEN.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH THAT WINDS REMAIN UNDER 10 KT TODAY.
* MEDIUM ON TIMING OF CIGS LIFTING THIS AFTERNOON.
* MEDIUM IN SHRA CHANCES LATE THIS AFTERNOON...LOW IN ANY TSRA
WITH THE LAKE BREEZE BOUNDARY...WHERE BETTER CHANCES EXIST
NORTH OF ORD.
* MEDIUM TO HIGH ON SHRA CHANCES THIS EVENING WITH UPPER LEVEL
DISTURBANCE AND MEDIUM ON TIMING OF THE COLD FRONT OVERNIGHT
TONIGHT.
* MEDIUM ON AT MVFR CIGS BEHIND THE FRONT LATE TONIGHT...LOW TO
MEDIUM ON IFR CIGS EARLY TOMORROW MORNING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. BREEZY NORTH TO NORTHWEST WINDS.
WEDNESDAY...VFR. NORTHWEST WINDS WITH POSSIBLE SHIFT TO NORTHEAST
WITH LAKE BREEZE.
THURSDAY...VFR. NORTH TO NORTHEAST WINDS.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN NORTHEAST WITH LAKE BREEZE IN
THE AFTERNOON.
SATURDAY AND SUNDAY...VFR. CHANCE TSRA. SOUTH TO SOUTHEAST WINDS.
KMD
&&
.MARINE...
314 AM CDT
AFTER FAIRLY QUIET CONDITIONS ON THE LAKE THROUGH EARLY
AFTERNOON...A MODEST COLD FRONT WILL MOVE OVER THE LAKE LATE TODAY
BRINGING A PERIOD OF NEAR GALE FORCE WINDS INTO TUESDAY.
LOW PRESSURE OVER THE OHIO VALLEY WILL DEEPEN AND PUSH NORTHEAST
TOWARD LAKE HURON BY DAYBREAK TUESDAY WHILE HIGH PRESSURE BUILDS
SOUTH INTO THE UPPER MIDWEST AND PLAINS STATES. AS THIS OCCURS A
COLD FRONT PASSES OVER THE LAKE BRINGING A PERIOD OF GUSTY
NORTHWEST TO NORTH WINDS. IT APPEARS THAT THE STRONGEST GRADIENT
WILL BE ON THE NORTH HALF OF THE LAKE WHERE THERE IS A BETTER
CHANCE FOR NEAR GALE FORCE....THOUGH SOLID WINDS TO 30 KT CAN BE
EXPECTED. WITH THE EXTENDED PERIOD OF NNW WINDS...WAVES WILL BUILD
ESPECIALLY ACROSS THE SOUTHERN HALF OF THE LAKE. SMALL CRAFT
ADVISORY CONDITIONS LOOK FAIRLY LIKELY FOR THE NEARSHORE WATERS...ESPECIALLY
DUE TO THE BUILDING WAVES...WITH AT LEAST A PERIOD OF 20-25 KT
POSSIBLE.
HIGH PRESSURE WILL BEGIN TO NOSE INTO THE GREAT LAKES REGION ON
WEDNESDAY AND BRING THE RETURN TO LAKE BREEZE INFLUENCE FOR THE
LATTER HALF OF THE WEEK.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 PM MONDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 PM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 PM
MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1256 PM CDT Mon Aug 11 2014
.UPDATE...
ISSUED AT 1000 AM CDT MON AUG 11 2014
Morning surface analysis shows low pressure centered over north-
central Indiana, with bulk of associated precip well to the E/NE
of the KILX CWA over northern Indiana/southern Michigan. Further
west in Illinois, only isolated showers persist along the I-57
corridor. As low moves further away and short-wave subsidence
develops behind departing upper wave, think conditions will be
mostly dry for the balance of the morning into the early
afternoon. Cold front currently across central Iowa will push
eastward later today, perhaps enhancing precip chances by mid to
late afternoon. While front will be encountering a moist airmass
with CAPE vales projected to be around 1500J/kg, poor convergence
along the boundary and extremely weak bulk shear will keep
convective development to a minimum. Both the 12z NAM and the
latest HRRR show only widely scattered showers/thunder developing
along the front across the Illinois River Valley after 1 PM, then
spreading eastward to the I-55 corridor by 4 to 5 PM. Will
therefore only carry 20-30 PoPs today into the early evening,
before ending precip chances entirely after midnight. Made a few
adjustments to PoPs and sky cover today, but temps appear to be
right on track so far.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 314 AM CDT MON AUG 11 2014
Patchy showers, with an occasional lightning strike evident,
continue to push slowly east across west-central Illinois early this
morning. These showers are ahead of an impulse that is quite
noticeable on water vapor imagery. A more widespread area of
showers/storms lies across northeast Illinois, associated with some
low-mid level convergence and weak WAA ahead of the above mentioned
impulse. Meanwhile, a cold front extends southwest into the upper
Midwest from northern Ontario. This front is being driven by a
couple upper level waves, and will eventually clear the forecast
area to the east by this evening.
High-resolution models suggest the west-central Illinois showers
should continue east for a time, but eventually weaken. Have my
doubts that this will occur as progged, as this feature will
eventually have diurnal instability to work with. Do not expect
severe storms today given weak shear profiles (bulk shear generally
20 kts or below), but peak diurnal instability should approach 1500
j/kg over most of the forecast area. This instability and the
available forcing should be able to produce scattered thunderstorms
across most of the forecast area today. The best coverage is expected
in the east, where the forcing from the west-central Illinois wave
and peak heating will co-exist for the longest period of time.
However, can`t rule out additional development until early evening
when the surface cold front and main upper wave pass east of the
area. Lingering cloud cover, as well as shower/storm threat, should
keep high temperatures today similar to the past two, generally in
the lower 80s.
&&
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 314 AM CDT MON AUG 11 2014
Strong upper level trof will be over the Ohio river valley Tue as
surface low pressure ejects ne to along the Quebec/Ontario province
line by sunset Tuesday. A few showers could occur over ne CWA Tue
while most of central IL should be dry Tue as skies become mostly
sunny Tue afternoon. Northwest breezes to bring in cooler and less
humid air as dewpoints slip into the upper 50s and lower 60s by days
end. Highs 75-80F on Tuesday with warmest readings by Lawrenceville.
Skies clear and nw winds diminish light by overnight Tuesday night
with cooler lows in the mid 50s. Upper level trof pulling away from
IL on Wed while 1021 mb Canadian high pressure settling into the
Midwest and keeps cooler and drier air in place through Thu night.
Highs Wed mostly in the upper 70s with lows Wed night in the upper
50s. Highs Thu in the lower 80s and dewpoints easing up into the
lower 60s Thu afternoon as surface ridge drifts east across IL.
Extended models diverge late this week and the models overall have
trended slower with arrival of next weather system late this week.
Most models are now drier on Friday over central/se IL with surface
high pressure ridge drifting slowly east into IN/OH/KY. Have lowered
pops Friday with eastern IL staying dry Friday, and having 20-30%
chance by Friday afternoon over western areas. Stayed close to
AllBlend during the extended forecast this weekend into early next
week which brings chances of showers and thunderstorms across the
area Friday night and Saturday with an approaching warm front from
the southwest. Warmer and more humid air to return to IL this
weekend as dewpoints elevate into the upper 60s and lower 70s. Upper
level ridge over IL by Sunday and this appears to be the warmest day
with highs in the mid to upper 80s. Main storm track to shift north
of central IL early next week and just have slight chances of
showers and thunderstorms Sunday-Monday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1256 PM CDT MON AUG 11 2014
Cold front currently along the Mississippi River will push
eastward this afternoon. A few radar returns are beginning to
develop along the boundary, but the latest HRRR continues to
suggest this activity will remain widely scattered in nature. Have
therefore included VCSH at the terminals ending by 00z at KPIA and
by around 02z further east at KCMI. Big question will be how much
cloud cover filters into the region behind the departing front
tonight into Tuesday. 1730z satellite imagery shows a large mass
of MVFR clouds dropping southeastward across northern/central
Iowa. Based on trajectories, these clouds should spill across
central Illinois this evening. NAM forecast soundings support this
theory: however, GFS is not nearly as aggressive. Based mainly
upon current upstream obs, have decided to be pessimistic with the
aviation forecast and include MVFR ceilings across the board
between 02z and 18z. Later forecasts may be fine-tuned if cloud
cover begins to erode after sunset or takes a more northerly
track.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...BAK
LONG TERM...07
AVIATION...BARNES
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1114 AM CDT MON AUG 11 2014
.DISCUSSION...
255 AM CDT
TODAY THROUGH TONIGHT...
IR IMAGERY INDICATES CONSIDERABLE CLOUDINESS ACROSS THE REGION EARLY
THIS MORNING. ANALYSIS INDICATES A MID-LVL WAVE SLIDING EAST
OVERHEAD THIS MORNING. THE COMBINATION OF THE UPPER LEVEL SYSTEM AND
CONSIDERABLE LLVL MOISTURE HAS ALLOWED AN AREA OF SHOWERS W/ISO
THUNDER THIS MORNING. THIS GENERALLY HAS BEEN FOCUSED ACROSS FAR
NORTHEAST IL. WITH THE PWAT VALUES HOVERING NEAR 1.7"...ANY SHOWER
ACTIVITY COULD EASILY PRODUCE BRIEF HEAVY DOWNPOURS. SOME OF THE
INSTANTANEOUS RATES HAVE HOVERED AROUND 4"/HR...FORTUNATELY THIS IS
ONLY LASTING FOR 10-15 MINS.
SPOTTY SHOWERS AND THUNDERSTORMS WILL CONTINUE THRU THIS MORNING AS
THE SHORTWAVE/TROUGH AXIS CONTINUES TO PIVOT EAST OVERHEAD. LLVL
MOISTURE CONVERGENCE WILL PERSIST...AND WITH THE HIGH DEW PTS/PWAT
VALUES...ANY SHOWERS COULD EASILY PRODUCE BRIEF HEAVY DOWNPOURS.
INSTABILITY WILL BE ELEVATED...SO HAVE HELD ONTO MENTION OF
THUNDERSTORMS. 850MB LOW WILL SLIGHTLY STRENGTHEN OVER THE OHIO
VALLEY AS IT ROTATES NORTHEAST ACROSS NORTHWEST OHIO THIS AFTN.
SFC WINDS WILL BE LIGHT TO VARIABLE TO START THE DAY...THEN BEGIN TO
SOLIDIFY FROM THE NORTHWEST. GIVEN THE CONSIDERABLE SOLAR
SHIELDING...EXPECT TEMPS TO STRUGGLE TO WARM TODAY. SO HAVE NUDGED
TEMPS DOWN A COUPLE OF DEGREES...INTO THE UPR 70S FOR THE NORTHEAST
CWFA AND ARND 80 IN OUR WESTERN FORECAST AREAS.
FOR THIS EVENING THE STRONGER TROUGH AXIS WILL BE APPROACHING THE
GREAT LAKES FROM THE NORTHWEST. LLVL MOISTURE WILL REMAIN ABUNDANT
OVER MUCH OF THE FORECAST AREA...SLOWLY PIVOTING TO THE EAST
OVERNIGHT INTO TUE MORNING. HAVE NUDGED POPS UP TOWARDS
LIKELY...MAINLY FOCUSED FOR THE NORTH/NORTHEAST CWFA. TEMPS ALOFT
WILL BE STEADILY COOLING...BUT EXPECT OVERNIGHT LOWS TO ONLY DROP
INTO THE LOW 60S TO MID 60S NEAR DOWNTOWN CHICAGO.
TUESDAY...
500MB VORT MAX WILL BE SLIDING SOUTHEAST ACROSS SOUTHEAST WISC
TOWARDS NORTHERN IN BY MIDDAY TUE. THIS IS SLIGHTLY FURTHER SOUTH
THEN PRIOR CYCLES...AND LOCAL ARW8KM SOLUTION INDICATES A FEW WEAKER
LOBES OF VORTICITY WILL ROTATE AROUND THE WESTERN PERIPHERY WITH
REINFORCING SLUGS OF PRECIP THRU MIDDAY TUE BEFORE DEPARTING TO THE
EAST AS ANTI-CYCLONIC FLOW STEADILY ERODES LLVL MOISTURE TUE EVE.
THERMAL TROUGH AT 850MB WILL SLOWLY SLIDE SOUTH ACROSS THE
REGION...GENERALLY BETWEEN 8-10 DEG C FOR MUCH OF THE FORECAST AREA.
THE STEADY NORTHERLY FLOW WILL LIKELY HOLD TEMPS IN THE LOW 70S FOR
MUCH OF THE CWFA. THE EXCEPTION COULD BE THE FAR WEST/SOUTHWEST
WHERE TEMPS COULD PUSH TO THE MID 70S. SFC RIDGING WILL WEAKEN THE
GRADIENT TUE NGT...WITH SKIES TRYING TO THIN. THIS WILL ALLOW TEMPS
TO RADIATE INTO THE LOW 50S...POSSIBLY UPR 40S IN THE MORE
TRADITIONAL COOL SPOTS TUE NGT. MEANWHILE AREAS ADJACENT TO LAKE
MICHIGAN WILL SEE TEMPS HOLD IN THE UPR 50S/LOW 60S.
WEDNESDAY THROUGH FRIDAY...
SFC RIDGE WILL BE IN CONTROL FOR MID-WEEK THRU FRI...LIKELY KEEPING
DRY AND PLEASANT CONDITIONS ACROSS THE REGION. LOCAL ARW8KM DOES
PAINT A WEAK LOBE OF VORTICITY TRYING TO SLIDE SOUTHEAST ACROSS THE
GREAT LAKES WED...HOWEVER FEEL MAINTAINING DRY CONDS IS THE MOST
PROBABLE OUTCOME FOR WED THRU FRI.
500MB VORT WILL BECOME QUASI-STATIONARY OVER SOUTHEAST ONTARIO WITH
HIGH AMPLITUDE RIDGING OVER THE CANADIAN ROCKIES KEEPING THE WESTERN
GREAT LAKES IN A NORTHWEST FLOW PATTERN.
TEMPS WILL GENERALLY BE IN THE UPR 70S...WITH A FEW SITES HITTING 80
OR ARND 80 BY THUR/FRI.
SATURDAY THROUGH SUNDAY...
ENSEMBLES HAVE CONTINUED MINIMAL SPREAD THRU SAT...HOWEVER BEYOND
THIS POINT THE SPREAD DRAMATICALLY INCREASES. ONE OF THE PROBLEMS
SOLUTIONS ARE STRUGGLING WITH IS TRYING TO WEAKEN THE DOWNSTREAM
BLOCK OF THE NORTH ATLANTIC...WHICH WILL HAVE AN IMPACT ON THE
TROUGH OVER SOUTHERN ONTARIO AND THE NORTHWEST FLOW FOR THE GREAT
LAKES. THERE IS SOME AGREEMENT THAT THE FLOW OVER THE GREAT
LAKES/UPPER MIDWEST WILL BEGIN TO FLATTEN AND TRANSITION TOWARDS A
SEMI-ZONAL PATTERN FOR THE WEEKEND...WHICH WILL BRING A SOMEWHAT
ACTIVE SETUP TO THE AREA. SO HAVE CHC POPS RETURNING LATE FRI THRU
SUN. TEMPS WILL BE SLOWLY RETURNING TO SEASONAL CONDITIONS OR IN THE
LOW 80S.
CONFIDENCE...MEDIUM.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CIGS GRADUALLY LIFTING THIS MORNING
* SHRA/TSRA CHANCES LATE THIS AFTERNOON ALONG A LAKE BREEZE AND
THEN AN INITIAL COLD FRONT/WIND SHIFT BOUNDARY
* SECOND AND BETTER CHANCE FOR SHRA/TSRA WITH AN UPPER LEVEL
DISTURBANCE THIS EVENING. ANOTHER CHANCE WITH A COLD FRONT
OVERNIGHT.
* MVFR/IFR CIGS BEHIND THE COLD FRONT EARLY TUESDAY
ED F
//DISCUSSION...UPDATED 12Z...
AN UPPER LEVEL DISTURBANCE IS PASSING THROUGH THE AREA THIS
MORNING AND IS DRIVING THE MAIN AREA OF -RA/TS INTO FAR NE IL AND
INTO NW IN. NOT EXPECTING ANY FURTHER TS THIS MORNING AT THE
CHICAGO TERMINALS OTHER THAN EAST OF A LINE FROM LANSING TO
KANKAKEE. LIGHTER WINDS AND MOIST LOW LEVELS WILL MEAN A PERIOD OF
MVFR/IFR VSBYS AND OR CIGS. AN UPPER LEVEL TROUGH WILL APPROACH
FROM THE NW LATER THIS AFTERNOON. ADDITIONALLY...A LAKE BREEZE IS
EXPECTED TO FORM. BOTH OF THESE BRING THE THE POTENTIAL FOR
ADDITIONAL SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND
EVENING...AND THEN AGAIN WITH THE COLD FRONTAL PASSAGE LATE
TONIGHT. EXPECT A PERIOD OF MVFR/IFR CONDITIONS BEHIND THE FRONT
AND GUSTY NW WINDS.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH THAT WINDS REMAIN UNDER 10 KT TODAY.
* LOW TO MEDIUM ON TIMING OF CIGS LIFTING THIS MORNING.
* MEDIUM IN SHRA CHANCES LATE THIS AFTERNOON... LOW IN ANY TSRA
WITH THE LAKE BREEZE BOUNDARY... WHERE BETTER CHANCES EXIST
NORTH OF ORD.
* MEDIUM TO HIGH ON SHRA CHANCES THIS EVENING WITH UPPER LEVEL
DISTURBANCE AND MEDIUM ON TIMING OF THE COLD FRONT OVERNIGHT
TONIGHT.
* MEDIUM ON AT LEAST MVFR CIGS BEHIND THE FRONT LATE
TONIGHT...POSSIBLY LOWER.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR. BREEZY NORTH TO NORTHWEST WINDS.
WEDNESDAY...VFR. NORTHWEST WINDS WITH POSSIBLE SHIFT TO NORTHEAST
WITH LAKE BREEZE.
THURSDAY...VFR. NORTH TO NORTHEAST WINDS.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN NORTHEAST WITH LAKE BREEZE IN
THE AFTERNOON.
SATURDAY AND SUNDAY...VFR. CHANCE TSRA. SOUTH TO SOUTHEAST WINDS.
KMD
&&
.MARINE...
314 AM CDT
AFTER FAIRLY QUIET CONDITIONS ON THE LAKE THROUGH EARLY
AFTERNOON...A MODEST COLD FRONT WILL MOVE OVER THE LAKE LATE TODAY
BRINGING A PERIOD OF NEAR GALE FORCE WINDS INTO TUESDAY.
LOW PRESSURE OVER THE OHIO VALLEY WILL DEEPEN AND PUSH NORTHEAST
TOWARD LAKE HURON BY DAYBREAK TUESDAY WHILE HIGH PRESSURE BUILDS
SOUTH INTO THE UPPER MIDWEST AND PLAINS STATES. AS THIS OCCURS A
COLD FRONT PASSES OVER THE LAKE BRINGING A PERIOD OF GUSTY
NORTHWEST TO NORTH WINDS. IT APPEARS THAT THE STRONGEST GRADIENT
WILL BE ON THE NORTH HALF OF THE LAKE WHERE THERE IS A BETTER
CHANCE FOR NEAR GALE FORCE....THOUGH SOLID WINDS TO 30 KT CAN BE
EXPECTED. WITH THE EXTENDED PERIOD OF NNW WINDS...WAVES WILL BUILD
ESPECIALLY ACROSS THE SOUTHERN HALF OF THE LAKE. SMALL CRAFT
ADVISORY CONDITIONS LOOK FAIRLY LIKELY FOR THE NEARSHORE WATERS...ESPECIALLY
DUE TO THE BUILDING WAVES...WITH AT LEAST A PERIOD OF 20-25 KT
POSSIBLE.
HIGH PRESSURE WILL BEGIN TO NOSE INTO THE GREAT LAKES REGION ON
WEDNESDAY AND BRING THE RETURN TO LAKE BREEZE INFLUENCE FOR THE
LATTER HALF OF THE WEEK.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ014 UNTIL 4 PM MONDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 4 PM MONDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 PM
MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1000 AM CDT Mon Aug 11 2014
.UPDATE...
ISSUED AT 1000 AM CDT MON AUG 11 2014
Morning surface analysis shows low pressure centered over
north-central Indiana, with bulk of associated precip well to the
E/NE of the KILX CWA over northern Indiana/southern Michigan.
Further west in Illinois, only isolated showers persist along the
I-57 corridor. As low moves further away and short-wave subsidence
develops behind departing upper wave, think conditions will be
mostly dry for the balance of the morning into the early
afternoon. Cold front currently across central Iowa will push
eastward later today, perhaps enhancing precip chances by mid to
late afternoon. While front will be encountering a moist airmass
with CAPE vales projected to be around 1500J/kg, poor convergence
along the boundary and extremely weak bulk shear will keep
convective development to a minimum. Both the 12z NAM and the
latest HRRR show only widely scattered showers/thunder developing
along the front across the Illinois River Valley after 1 PM, then
spreading eastward to the I-55 corridor by 4 to 5 PM. Will
therefore only carry 20-30 PoPs today into the early evening,
before ending precip chances entirely after midnight. Made a few
adjustments to PoPs and sky cover today, but temps appear to be
right on track so far.
&&
.SHORT TERM...(This afternoon through Tuesday)
ISSUED AT 314 AM CDT MON AUG 11 2014
Patchy showers, with an occasional lightning strike evident,
continue to push slowly east across west-central Illinois early this
morning. These showers are ahead of an impulse that is quite
noticeable on water vapor imagery. A more widespread area of
showers/storms lies across northeast Illinois, associated with some
low-mid level convergence and weak WAA ahead of the above mentioned
impulse. Meanwhile, a cold front extends southwest into the upper
Midwest from northern Ontario. This front is being driven by a
couple upper level waves, and will eventually clear the forecast
area to the east by this evening.
High-resolution models suggest the west-central Illinois showers
should continue east for a time, but eventually weaken. Have my
doubts that this will occur as progged, as this feature will
eventually have diurnal instability to work with. Do not expect
severe storms today given weak shear profiles (bulk shear generally
20 kts or below), but peak diurnal instability should approach 1500
j/kg over most of the forecast area. This instability and the
available forcing should be able to produce scattered thunderstorms
across most of the forecast area today. The best coverage is expected
in the east, where the forcing from the west-central Illinois wave
and peak heating will co-exist for the longest period of time.
However, can`t rule out additional development until early evening
when the surface cold front and main upper wave pass east of the
area. Lingering cloud cover, as well as shower/storm threat, should
keep high temperatures today similar to the past two, generally in
the lower 80s.
&&
.LONG TERM...(Tuesday night through Sunday)
ISSUED AT 314 AM CDT MON AUG 11 2014
Strong upper level trof will be over the Ohio river valley Tue as
surface low pressure ejects ne to along the Quebec/Ontario province
line by sunset Tuesday. A few showers could occur over ne CWA Tue
while most of central IL should be dry Tue as skies become mostly
sunny Tue afternoon. Northwest breezes to bring in cooler and less
humid air as dewpoints slip into the upper 50s and lower 60s by days
end. Highs 75-80F on Tuesday with warmest readings by Lawrenceville.
Skies clear and nw winds diminish light by overnight Tuesday night
with cooler lows in the mid 50s. Upper level trof pulling away from
IL on Wed while 1021 mb Canadian high pressure settling into the
Midwest and keeps cooler and drier air in place through Thu night.
Highs Wed mostly in the upper 70s with lows Wed night in the upper
50s. Highs Thu in the lower 80s and dewpoints easing up into the
lower 60s Thu afternoon as surface ridge drifts east across IL.
Extended models diverge late this week and the models overall have
trended slower with arrival of next weather system late this week.
Most models are now drier on Friday over central/se IL with surface
high pressure ridge drifting slowly east into IN/OH/KY. Have lowered
pops Friday with eastern IL staying dry Friday, and having 20-30%
chance by Friday afternoon over western areas. Stayed close to
AllBlend during the extended forecast this weekend into early next
week which brings chances of showers and thunderstorms across the
area Friday night and Saturday with an approaching warm front from
the southwest. Warmer and more humid air to return to IL this
weekend as dewpoints elevate into the upper 60s and lower 70s. Upper
level ridge over IL by Sunday and this appears to be the warmest day
with highs in the mid to upper 80s. Main storm track to shift north
of central IL early next week and just have slight chances of
showers and thunderstorms Sunday-Monday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 654 AM CDT MON AUG 11 2014
MVFR/IFR conditions across the central Illinois terminals to start
the day, with scattered showers and isolated thunderstorms in the
vicinity. Covered this precipitation with a few hour tempo for
showers at all locations. Then, a break is expected in the
precipitation, with conditions improving to VFR by mid-late
morning. A few showers/storms may return by late afternoon ahead
of a weak cold front, but coverage and timing certainty is too low
to go above a VCSH mention. Rain chances will end tonight, but
cigs/vsbys are likely to return to MVFR (or lower) behind the
front overnight.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARNES
SHORT TERM...BARNES
LONG TERM...07
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
124 PM EDT MON AUG 11 2014
.SYNOPSIS...
ISSUED AT 1102 AM EDT MON AUG 11 2014
A LOW PRESSURE SYSTEM WILL MOVE THROUGH THE REGION TODAY INTO
TONIGHT AND AN UPPER LEVEL TROUGH WILL MOVE THROUGH TONIGHT INTO
TOMORROW. THESE TWO WILL CAUSE PERIODS OF SHOWERS AND
THUNDERSTORMS THROUGH TOMORROW. HIGH TEMPERATURES WILL RANGE FROM
THE MIDDLE 70S IN THE NORTH TO THE UPPER 70S NEAR THE OHIO RIVER.
LOW TEMPERATURES TONIGHT WILL RANGE FROM THE LOWER 60S IN SOUTHERN
MICHIGAN TO THE UPPER 60S ALONG THE OHIO RIVER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM EDT MON AUG 11 2014
SLOW MOVING SFC LOW ACROSS OH VALLEY WILL FINALLY BEGIN TO SHIFT NE
TODAY AS SHORTWAVE IS INGESTED INTO AMPLIFYING UPPER LEVEL TROF. AS
TROF APPROACHES...SFC LOW WILL UNDERGO STRENGTHENING AS IT MOVES
THRU CWA DURING THE DAY. EARLY MORNING SHOWERS/ISOLATED TSTORMS
CURRENTLY MOVING INTO SOUTHERN PORTIONS OF CWA WILL CONTINUE TO MOVE
NORTH ALONG SFC BOUNDARY ALTHO MAY WEAKEN AS INSTABILITY IS WANING.
ADDITIONAL DEVELOPMENT IS OCCURRING TO THE WEST ACROSS N IL MORE
CLOSELY TIED TO UPPER SYSTEM. THIS WILL CONTINUE TO EXPAND INTO THE
AREA THROUGHOUT THE MORNING AND INTO THE AFTERNOON HOURS. NORTHWARD
SURGE OF MOISTURE IN LOWER LEVELS WITH PWATS IN EXCESS OF 1.7-1.9
AND CONVERGENCE WILL AID IN THE DEVELOPMENT OF ADDITIONAL CONVECTION
WITH THE CHANCES FOR NEEDED RAINFALL LOOKING PRETTY WIDESPREAD.
THUNDER COVERAGE MAY BE SOMEWHAT LIMITED BY MARGINAL INSTABILITY
GIVEN THE FACT THAT CLOUD COVER MAY HINDER DESTABILIZATION. THIS AS
WELL AS WEAK SHEAR VALUES SHOULD KEEP THE STORMS NON-SEVERE.
REGARDLESS....RAINFALL AMOUNTS MAY EXCEED 1" IN SOME LOCATIONS GIVEN
AMPLE MOISTURE AND SLOW MOVEMENT OF STORMS. MODELS IN DECENT
AGREEMENT WITH TRACK OF SYSTEM AND LATEST HRRR RUNS ARE ACTUALLY
HANDLING CURRENT SITUATION WELL. HAVE TRIED TO INCORPORATE TIMING
AND COVERAGE INTO POP/WX GRIDS WHICH RESULTED IN SLIGHT ADJUSTMENT
TO PREVIOUS GRIDS. SHOWERS MAY LINGER INTO TONIGHT DUE TO PROXIMITY
OF UPPER TROF ROTATING THRU AREA.
HIGHS TODAY WILL BE SOME 5-10 DEGREES COOLER THAN SUNDAY...GENERALLY
IN THE UPPER 70S. OVERNIGHT LOWS WILL BE IN THE 60S.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM EDT MON AUG 11 2014
ON TUESDAY...A STRONG UPPER VORT MAX WILL BE DROPPING INTO THE
SOUTHERN GREAT LAKES REGION TO START THE DAY WITH AN ASSOCIATED
SECONDARY WEAK SFC TROUGH ACCOMPANYING THIS FORCING.
MEANWHILE...MID/UPPER LEVEL TROUGH ACROSS NORTHERN OHIO WILL BE
DEPARTING TO THE EAST WITH PERHAPS SOME CONTINUED SCATTERED RAIN
SHOWERS IN THE EARLY MORNING IN DEPARTING DEFORMATION ZONE WITH THIS
FEATURE. GIVEN THESE TWO FORCING MECHANISMS HAVE MAINTAINED LOW TO
MID CHANCE POPS IN THE MORNING...BUT LOW LEVEL DRY AIR ADVECTION
WILL DEVELOP IN THE WAKE OF THIS FEATURE FROM WEST TO EAST FROM MID
MORNING INTO THE AFTERNOON HOURS. INHERITED POP GRADIENT DIMINISHING
FROM WEST TO EAST DURING THE AFTERNOON STILL APPEARS REASONABLE
GIVEN THE ABOVE...AND WHILE WIDESPREAD MEASURABLE PRECIP IS NOT
EXPECTED BY AFTERNOON...SOME PATCHY DRIZZLE MAY DEVELOP AS DRY SLOT
LIFTS INTO THE AREA. GIVEN CAA...LOW CLOUDS...AND PRECIP HAVE
MAINTAINED HIGHS FROM PREVIOUS FORECAST IN THE 70 TO 75 DEGREE
RANGE. POTENTIAL OF THUNDER STILL APPEARS TO BE QUITE MINIMAL WITH
AXIS OF WEAK INSTABILITY SHIFTING INTO OHIO TOWARD MIDDAY.
SEVERAL SMALLER SCALE VORTS ROTATING CYCLONICALLY AROUND DEEPENING
PARENT UPPER TROUGH MAY ALLOW FOR A SLOW ENOUGH EVOLUTION OF
MID/UPPER TROUGH AXIS TO KEEP SOME ISOLD/SCT LIGHT RAIN SHOWERS
ACROSS NORTHWEST OHIO DURING THE EARLY EVENING HOURS TUESDAY...BUT
THIS SHOULD BE FOLLOWED BY A DIMINISHING CLOUD TREND DURING THE
REMAINDER OF THE OVERNIGHT. STILL SOME LOWER CONFIDENCE ON TEMPS
TUESDAY NIGHT WITH EFFECTS OF COOLER AIRMASS ADVECTING INTO THE AREA
POSSIBLY PARTIALLY OFFSET IF LOW CLOUDS HANG ON LONGER THAN
EXPECTED...AND BY MODEST LOW LEVEL HEIGHT GRADIENT.
QUIET CONDITIONS ARE THEN EXPECTED FOR THE WED-FRI TIMEFRAME WITH
SOME INDICATIONS OF ANOTHER WEAK SFC TROUGH/REINFORCING COLD FRONT
BY THE THURSDAY TIMEFRAME. STRONG SUBSIDENCE ON WEDNESDAY AND BETTER
CHANCES OF INSOLATION COULD ALLOW FOR SOME RECOVERY OF AFTERNOON
HIGHS INTO THE MID AND UPPER 70S BEFORE SLIGHTLY COOLER AIR ADVECTS
INTO THE AREA AGAIN ON THURSDAY. WILL KEEP THIS WEAK FROPA
DRY...WITH LACK OF ANY SIGNIFICANT DEEP MOISTURE.
MEDIUM RANGE MODELS HAVE LACKED CONSISTENCY WITH TREND TO A MORE
DEAMPLIFIED FLOW PATTERN BY NEXT WEEKEND...WITH PRECIP CHANCES FOR
SATURDAY NOW LOOKING A LITTLE MORE QUESTIONABLE AND PERHAPS DELAYED.
GIVEN THIS RUN TO RUN INCONSISTENCY HAVE OPTED TO MAKE NO CHANGES TO
POPS FOR SAT/SUN AT THIS TIME AND LET FUTURE SHIFTS ASSESS
POSSIBILITY OF REMOVING SAT POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 123 PM EDT MON AUG 11 2014
POTENT PV ANOMALY WORKING EWD THROUGH CNTRL IN YIELDING AN ABUNDANCE
OF SHRA/TSRA FM NW OH SWWD THROUGH CNTRL IN. HWVR BACK EDGE OF
WIDESPREAD RAIN SHIELD WILL CONT TO WORK ENE THROUGH THE REMAINDER
OF THIS AFTN AND XPC MAINLY DRY CONDS TO PREVAIL IN WAKE OF THIS SYS
AS DEEP LYRD SUBSIDENCE ENSUES.
OTRWS STG UPSTREAM SW TROUGH ACRS MN WILL DIG SEWD TONIGHT AND
BOTTOM ACRS SRN MI. MIXED MODEL SIGNALS SPELL CONSIDERABLE
UNCERTAINTY THROUGH SRN PERIPHERY OF H7-5 MID LVL TROUGH ALTHOUGH
SOME THETA-E RTN IS INDICATED AT H85 AFT MIDNIGHT TONIGHT WHICH MAY
FOSTER REDVLPMNT OF SHRA ACRS NW ZONES INCLUDING KSBN TERMINAL TWD
12Z YET NOT SOLD ENOUGH ON THE IDEA YET TO INCLUDE IN 18Z FCST. BTR
CHCS LOOK TO MATERIALIZE TWD 18Z AT KFWA W/MUCH BTR DIURNAL TIMING
INDICATED AND CLOSER PROXIMITY TO LL THETA-E RTN RIDGE AHD OF MID
LVL TROUGH AXIS. ALTHOUGH HERE TOO KEPT W/DRY FCST ATTM GIVEN LT PD
TIMING AND GENERAL HIGH SPREAD IN MODEL TIMING.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT UNTIL 4 PM CDT THIS AFTERNOON FOR INZ003.
MI...BEACH HAZARDS STATEMENT UNTIL 5 PM EDT THIS AFTERNOON FOR MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ043-
046.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...CEO
LONG TERM...MARSILI
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1106 AM EDT MON AUG 11 2014
.SYNOPSIS...
ISSUED AT 1102 AM EDT MON AUG 11 2014
A LOW PRESSURE SYSTEM WILL MOVE THROUGH THE REGION TODAY INTO
TONIGHT AND AN UPPER LEVEL TROUGH WILL MOVE THROUGH TONIGHT INTO
TOMORROW. THESE TWO WILL CAUSE PERIODS OF SHOWERS AND
THUNDERSTORMS THROUGH TOMORROW. HIGH TEMPERATURES WILL RANGE FROM
THE MIDDLE 70S IN THE NORTH TO THE UPPER 70S NEAR THE OHIO RIVER.
LOW TEMPERATURES TONIGHT WILL RANGE FROM THE LOWER 60S IN SOUTHERN
MICHIGAN TO THE UPPER 60S ALONG THE OHIO RIVER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM EDT MON AUG 11 2014
SLOW MOVING SFC LOW ACROSS OH VALLEY WILL FINALLY BEGIN TO SHIFT NE
TODAY AS SHORTWAVE IS INGESTED INTO AMPLIFYING UPPER LEVEL TROF. AS
TROF APPROACHES...SFC LOW WILL UNDERGO STRENGTHENING AS IT MOVES
THRU CWA DURING THE DAY. EARLY MORNING SHOWERS/ISOLATED TSTORMS
CURRENTLY MOVING INTO SOUTHERN PORTIONS OF CWA WILL CONTINUE TO MOVE
NORTH ALONG SFC BOUNDARY ALTHO MAY WEAKEN AS INSTABILITY IS WANING.
ADDITIONAL DEVELOPMENT IS OCCURRING TO THE WEST ACROSS N IL MORE
CLOSELY TIED TO UPPER SYSTEM. THIS WILL CONTINUE TO EXPAND INTO THE
AREA THROUGHOUT THE MORNING AND INTO THE AFTERNOON HOURS. NORTHWARD
SURGE OF MOISTURE IN LOWER LEVELS WITH PWATS IN EXCESS OF 1.7-1.9
AND CONVERGENCE WILL AID IN THE DEVELOPMENT OF ADDITIONAL CONVECTION
WITH THE CHANCES FOR NEEDED RAINFALL LOOKING PRETTY WIDESPREAD.
THUNDER COVERAGE MAY BE SOMEWHAT LIMITED BY MARGINAL INSTABILITY
GIVEN THE FACT THAT CLOUD COVER MAY HINDER DESTABILIZATION. THIS AS
WELL AS WEAK SHEAR VALUES SHOULD KEEP THE STORMS NON-SEVERE.
REGARDLESS....RAINFALL AMOUNTS MAY EXCEED 1" IN SOME LOCATIONS GIVEN
AMPLE MOISTURE AND SLOW MOVEMENT OF STORMS. MODELS IN DECENT
AGREEMENT WITH TRACK OF SYSTEM AND LATEST HRRR RUNS ARE ACTUALLY
HANDLING CURRENT SITUATION WELL. HAVE TRIED TO INCORPORATE TIMING
AND COVERAGE INTO POP/WX GRIDS WHICH RESULTED IN SLIGHT ADJUSTMENT
TO PREVIOUS GRIDS. SHOWERS MAY LINGER INTO TONIGHT DUE TO PROXIMITY
OF UPPER TROF ROTATING THRU AREA.
HIGHS TODAY WILL BE SOME 5-10 DEGREES COOLER THAN SUNDAY...GENERALLY
IN THE UPPER 70S. OVERNIGHT LOWS WILL BE IN THE 60S.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM EDT MON AUG 11 2014
ON TUESDAY...A STRONG UPPER VORT MAX WILL BE DROPPING INTO THE
SOUTHERN GREAT LAKES REGION TO START THE DAY WITH AN ASSOCIATED
SECONDARY WEAK SFC TROUGH ACCOMPANYING THIS FORCING.
MEANWHILE...MID/UPPER LEVEL TROUGH ACROSS NORTHERN OHIO WILL BE
DEPARTING TO THE EAST WITH PERHAPS SOME CONTINUED SCATTERED RAIN
SHOWERS IN THE EARLY MORNING IN DEPARTING DEFORMATION ZONE WITH THIS
FEATURE. GIVEN THESE TWO FORCING MECHANISMS HAVE MAINTAINED LOW TO
MID CHANCE POPS IN THE MORNING...BUT LOW LEVEL DRY AIR ADVECTION
WILL DEVELOP IN THE WAKE OF THIS FEATURE FROM WEST TO EAST FROM MID
MORNING INTO THE AFTERNOON HOURS. INHERITED POP GRADIENT DIMINISHING
FROM WEST TO EAST DURING THE AFTERNOON STILL APPEARS REASONABLE
GIVEN THE ABOVE...AND WHILE WIDESPREAD MEASURABLE PRECIP IS NOT
EXPECTED BY AFTERNOON...SOME PATCHY DRIZZLE MAY DEVELOP AS DRY SLOT
LIFTS INTO THE AREA. GIVEN CAA...LOW CLOUDS...AND PRECIP HAVE
MAINTAINED HIGHS FROM PREVIOUS FORECAST IN THE 70 TO 75 DEGREE
RANGE. POTENTIAL OF THUNDER STILL APPEARS TO BE QUITE MINIMAL WITH
AXIS OF WEAK INSTABILITY SHIFTING INTO OHIO TOWARD MIDDAY.
SEVERAL SMALLER SCALE VORTS ROTATING CYCLONICALLY AROUND DEEPENING
PARENT UPPER TROUGH MAY ALLOW FOR A SLOW ENOUGH EVOLUTION OF
MID/UPPER TROUGH AXIS TO KEEP SOME ISOLD/SCT LIGHT RAIN SHOWERS
ACROSS NORTHWEST OHIO DURING THE EARLY EVENING HOURS TUESDAY...BUT
THIS SHOULD BE FOLLOWED BY A DIMINISHING CLOUD TREND DURING THE
REMAINDER OF THE OVERNIGHT. STILL SOME LOWER CONFIDENCE ON TEMPS
TUESDAY NIGHT WITH EFFECTS OF COOLER AIRMASS ADVECTING INTO THE AREA
POSSIBLY PARTIALLY OFFSET IF LOW CLOUDS HANG ON LONGER THAN
EXPECTED...AND BY MODEST LOW LEVEL HEIGHT GRADIENT.
QUIET CONDITIONS ARE THEN EXPECTED FOR THE WED-FRI TIMEFRAME WITH
SOME INDICATIONS OF ANOTHER WEAK SFC TROUGH/REINFORCING COLD FRONT
BY THE THURSDAY TIMEFRAME. STRONG SUBSIDENCE ON WEDNESDAY AND BETTER
CHANCES OF INSOLATION COULD ALLOW FOR SOME RECOVERY OF AFTERNOON
HIGHS INTO THE MID AND UPPER 70S BEFORE SLIGHTLY COOLER AIR ADVECTS
INTO THE AREA AGAIN ON THURSDAY. WILL KEEP THIS WEAK FROPA
DRY...WITH LACK OF ANY SIGNIFICANT DEEP MOISTURE.
MEDIUM RANGE MODELS HAVE LACKED CONSISTENCY WITH TREND TO A MORE
DEAMPLIFIED FLOW PATTERN BY NEXT WEEKEND...WITH PRECIP CHANCES FOR
SATURDAY NOW LOOKING A LITTLE MORE QUESTIONABLE AND PERHAPS DELAYED.
GIVEN THIS RUN TO RUN INCONSISTENCY HAVE OPTED TO MAKE NO CHANGES TO
POPS FOR SAT/SUN AT THIS TIME AND LET FUTURE SHIFTS ASSESS
POSSIBILITY OF REMOVING SAT POPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 730 AM EDT MON AUG 11 2014
SFC LOW PRESSURE WILL TRACK ACROSS NORTHEAST INDIANA THIS MORNING.
CYCLONIC FLOW AROUND THIS LOW LEVEL REFLECTION HAS ALLOWED
INCREASED LOW LEVEL MOISTURE TO BUILD NORTHWARD ACROSS NORTHERN
INDIANA THIS MORNING. THE COMBINATION OF CONVERGENT FLOW AND AN
UPSTREAM SHORT WAVE WORKING INTO NORTHWEST INDIANA THIS MORNING
WILL RESULT IN WIDESPREAD RAIN TO OVERSPREAD THE AREA THIS
MORNING...WITH GREATEST COVERAGE EXPECTED TO AFFECT KSBN THROUGH
EARLY AFTERNOON. SFC OR NEAR SFC BASED INSTABILITY OF AROUND 1000
J/KG IS EXPECTED TO DEVELOP LATER THIS MORNING AND SHOULD SUPPORT
AT LEAST SCATTERED THUNDER. ONLY CHANGE OF NOTE FOR THE 12Z TAFS
WAS TO MOVE UP TIMING OF THUNDER TO LATE MORNING/EARLY
AFTERNOON...ALTHOUGH GIVEN SETUP...REALLY CANNOT RULE OUT TS ANY
TIME OVER THE NEXT 6 TO 9 HOURS AND WILL NEED TO BE MONITORED. WITH
SFC REFLECTION MOVING ACROSS THE AREA WINDS WILL BE RELATIVELY
NIGHT...EVENTUALLY FAVORING NORTH-NORTHWEST LATER THIS AFTERNOON
AS IT DEPARTS TO THE EAST. DID HOLD ONTO MVFR CONDITIONS TONIGHT
WITH MOISTURE LINGERING ACROSS THE AREA IN ADVANCE OF NEXT SHORT
WAVE...BUT MAY EVENTUALLY NEED TO ASSESS POTENTIAL FOR MORE
PESSIMISTIC CONDITIONS LATE TONIGHT IN FUTURE FORECASTS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT UNTIL 4 PM CDT THIS AFTERNOON FOR INZ003.
MI...BEACH HAZARDS STATEMENT UNTIL 5 PM EDT THIS AFTERNOON FOR MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LMZ043-
046.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...CEO
LONG TERM...MARSILI
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
749 AM EDT MON AUG 11 2014
.SYNOPSIS...
ISSUED AT 344 AM EDT MON AUG 11 2014
A LOW PRESSURE SYSTEM WILL SHIFT NORTHEAST ACROSS THE REGION
TODAY. THIS COMBINED WITH AN UPPER LEVEL SYSTEM WILL CAUSE PERIODS
OF SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE AREA TODAY INTO
TUESDAY. HIGH PRESSURE WILL BUILD IN BEHIND THIS SYSTEM ALLOWING
FOR DRY WEATHER WEDNESDAY INTO THE END OF THE WORK WEEK. HIGHS
TODAY WILL IN THE MID TO UPPER 70S WITH OVERNIGHT LOWS IN THE 60S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM EDT MON AUG 11 2014
SLOW MOVING SFC LOW ACROSS OH VALLEY WILL FINALLY BEGIN TO SHIFT NE
TODAY AS SHORTWAVE IS INGESTED INTO AMPLIFYING UPPER LEVEL TROF. AS
TROF APPROACHES...SFC LOW WILL UNDERGO STRENGTHENING AS IT MOVES
THRU CWA DURING THE DAY. EARLY MORNING SHOWERS/ISOLATED TSTORMS
CURRENTLY MOVING INTO SOUTHERN PORTIONS OF CWA WILL CONTINUE TO MOVE
NORTH ALONG SFC BOUNDARY ALTHO MAY WEAKEN AS INSTABILITY IS WANING.
ADDITIONAL DEVELOPMENT IS OCCURRING TO THE WEST ACROSS N IL MORE
CLOSELY TIED TO UPPER SYSTEM. THIS WILL CONTINUE TO EXPAND INTO THE
AREA THROUGHOUT THE MORNING AND INTO THE AFTERNOON HOURS. NORTHWARD
SURGE OF MOISTURE IN LOWER LEVELS WITH PWATS IN EXCESS OF 1.7-1.9
AND CONVERGENCE WILL AID IN THE DEVELOPMENT OF ADDITIONAL CONVECTION
WITH THE CHANCES FOR NEEDED RAINFALL LOOKING PRETTY WIDESPREAD.
THUNDER COVERAGE MAY BE SOMEWHAT LIMITED BY MARGINAL INSTABILITY
GIVEN THE FACT THAT CLOUD COVER MAY HINDER DESTABILIZATION. THIS AS
WELL AS WEAK SHEAR VALUES SHOULD KEEP THE STORMS NON-SEVERE.
REGARDLESS....RAINFALL AMOUNTS MAY EXCEED 1" IN SOME LOCATIONS GIVEN
AMPLE MOISTURE AND SLOW MOVEMENT OF STORMS. MODELS IN DECENT
AGREEMENT WITH TRACK OF SYSTEM AND LATEST HRRR RUNS ARE ACTUALLY
HANDLING CURRENT SITUATION WELL. HAVE TRIED TO INCORPORATE TIMING
AND COVERAGE INTO POP/WX GRIDS WHICH RESULTED IN SLIGHT ADJUSTMENT
TO PREVIOUS GRIDS. SHOWERS MAY LINGER INTO TONIGHT DUE TO PROXIMITY
OF UPPER TROF ROTATING THRU AREA.
HIGHS TODAY WILL BE SOME 5-10 DEGREES COOLER THAN SUNDAY...GENERALLY
IN THE UPPER 70S. OVERNIGHT LOWS WILL BE IN THE 60S.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM EDT MON AUG 11 2014
ON TUESDAY...A STRONG UPPER VORT MAX WILL BE DROPPING INTO THE
SOUTHERN GREAT LAKES REGION TO START THE DAY WITH AN ASSOCIATED
SECONDARY WEAK SFC TROUGH ACCOMPANYING THIS FORCING.
MEANWHILE...MID/UPPER LEVEL TROUGH ACROSS NORTHERN OHIO WILL BE
DEPARTING TO THE EAST WITH PERHAPS SOME CONTINUED SCATTERED RAIN
SHOWERS IN THE EARLY MORNING IN DEPARTING DEFORMATION ZONE WITH THIS
FEATURE. GIVEN THESE TWO FORCING MECHANISMS HAVE MAINTAINED LOW TO
MID CHANCE POPS IN THE MORNING...BUT LOW LEVEL DRY AIR ADVECTION
WILL DEVELOP IN THE WAKE OF THIS FEATURE FROM WEST TO EAST FROM MID
MORNING INTO THE AFTERNOON HOURS. INHERITED POP GRADIENT DIMINISHING
FROM WEST TO EAST DURING THE AFTERNOON STILL APPEARS REASONABLE
GIVEN THE ABOVE...AND WHILE WIDESPREAD MEASURABLE PRECIP IS NOT
EXPECTED BY AFTERNOON...SOME PATCHY DRIZZLE MAY DEVELOP AS DRY SLOT
LIFTS INTO THE AREA. GIVEN CAA...LOW CLOUDS...AND PRECIP HAVE
MAINTAINED HIGHS FROM PREVIOUS FORECAST IN THE 70 TO 75 DEGREE
RANGE. POTENTIAL OF THUNDER STILL APPEARS TO BE QUITE MINIMAL WITH
AXIS OF WEAK INSTABILITY SHIFTING INTO OHIO TOWARD MIDDAY.
SEVERAL SMALLER SCALE VORTS ROTATING CYCLONICALLY AROUND DEEPENING
PARENT UPPER TROUGH MAY ALLOW FOR A SLOW ENOUGH EVOLUTION OF
MID/UPPER TROUGH AXIS TO KEEP SOME ISOLD/SCT LIGHT RAIN SHOWERS
ACROSS NORTHWEST OHIO DURING THE EARLY EVENING HOURS TUESDAY...BUT
THIS SHOULD BE FOLLOWED BY A DIMINISHING CLOUD TREND DURING THE
REMAINDER OF THE OVERNIGHT. STILL SOME LOWER CONFIDENCE ON TEMPS
TUESDAY NIGHT WITH EFFECTS OF COOLER AIRMASS ADVECTING INTO THE AREA
POSSIBLY PARTIALLY OFFSET IF LOW CLOUDS HANG ON LONGER THAN
EXPECTED...AND BY MODEST LOW LEVEL HEIGHT GRADIENT.
QUIET CONDITIONS ARE THEN EXPECTED FOR THE WED-FRI TIMEFRAME WITH
SOME INDICATIONS OF ANOTHER WEAK SFC TROUGH/REINFORCING COLD FRONT
BY THE THURSDAY TIMEFRAME. STRONG SUBSIDENCE ON WEDNESDAY AND BETTER
CHANCES OF INSOLATION COULD ALLOW FOR SOME RECOVERY OF AFTERNOON
HIGHS INTO THE MID AND UPPER 70S BEFORE SLIGHTLY COOLER AIR ADVECTS
INTO THE AREA AGAIN ON THURSDAY. WILL KEEP THIS WEAK FROPA
DRY...WITH LACK OF ANY SIGNIFICANT DEEP MOISTURE.
MEDIUM RANGE MODELS HAVE LACKED CONSISTENCY WITH TREND TO A MORE
DEAMPLIFIED FLOW PATTERN BY NEXT WEEKEND...WITH PRECIP CHANCES FOR
SATURDAY NOW LOOKING A LITTLE MORE QUESTIONABLE AND PERHAPS DELAYED.
GIVEN THIS RUN TO RUN INCONSISTENCY HAVE OPTED TO MAKE NO CHANGES TO
POPS FOR SAT/SUN AT THIS TIME AND LET FUTURE SHIFTS ASSESS
POSSIBILITY OF REMOVING SAT POPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 730 AM EDT MON AUG 11 2014
SFC LOW PRESSURE WILL TRACK ACROSS NORTHEAST INDIANA THIS MORNING.
CYCLONIC FLOW AROUND THIS LOW LEVEL REFLECTION HAS ALLOWED
INCREASED LOW LEVEL MOISTURE TO BUILD NORTHWARD ACROSS NORTHERN
INDIANA THIS MORNING. THE COMBINATION OF CONVERGENT FLOW AND AN
UPSTREAM SHORT WAVE WORKING INTO NORTHWEST INDIANA THIS MORNING
WILL RESULT IN WIDESPREAD RAIN TO OVERSPREAD THE AREA THIS
MORNING...WITH GREATEST COVERAGE EXPECTED TO AFFECT KSBN THROUGH
EARLY AFTERNOON. SFC OR NEAR SFC BASED INSTABILITY OF AROUND 1000
J/KG IS EXPECTED TO DEVELOP LATER THIS MORNING AND SHOULD SUPPORT
AT LEAST SCATTERED THUNDER. ONLY CHANGE OF NOTE FOR THE 12Z TAFS
WAS TO MOVE UP TIMING OF THUNDER TO LATE MORNING/EARLY
AFTERNOON...ALTHOUGH GIVEN SETUP...REALLY CANNOT RULE OUT TS ANY
TIME OVER THE NEXT 6 TO 9 HOURS AND WILL NEED TO BE MONITORED. WITH
SFC REFLECTION MOVING ACROSS THE AREA WINDS WILL BE RELATIVELY
NIGHT...EVENTUALLY FAVORING NORTH-NORTHWEST LATER THIS AFTERNOON
AS IT DEPARTS TO THE EAST. DID HOLD ONTO MVFR CONDITIONS TONIGHT
WITH MOISTURE LINGERING ACROSS THE AREA IN ADVANCE OF NEXT SHORT
WAVE...BUT MAY EVENTUALLY NEED TO ASSESS POTENTIAL FOR MORE
PESSIMISTIC CONDITIONS LATE TONIGHT IN FUTURE FORECASTS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...CEO
SHORT TERM...CEO
LONG TERM...MARSILI
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
346 AM EDT MON AUG 11 2014
.SYNOPSIS...
ISSUED AT 344 AM EDT MON AUG 11 2014
A LOW PRESSURE SYSTEM WILL SHIFT NORTHEAST ACROSS THE REGION
TODAY. THIS COMBINED WITH AN UPPER LEVEL SYSTEM WILL CAUSE PERIODS
OF SHOWERS AND ISOLATED THUNDERSTORMS ACROSS THE AREA TODAY INTO
TUESDAY. HIGH PRESSURE WILL BUILD IN BEHIND THIS SYSTEM ALLOWING
FOR DRY WEATHER WEDNESDAY INTO THE END OF THE WORK WEEK. HIGHS
TODAY WILL IN THE MID TO UPPER 70S WITH OVERNIGHT LOWS IN THE 60S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 344 AM EDT MON AUG 11 2014
SLOW MOVING SFC LOW ACROSS OH VALLEY WILL FINALLY BEGIN TO SHIFT NE
TODAY AS SHORTWAVE IS INGESTED INTO AMPLIFYING UPPER LEVEL TROF. AS
TROF APPROACHES...SFC LOW WILL UNDERGO STRENGTHENING AS IT MOVES
THRU CWA DURING THE DAY. EARLY MORNING SHOWERS/ISOLATED TSTORMS
CURRENTLY MOVING INTO SOUTHERN PORTIONS OF CWA WILL CONTINUE TO MOVE
NORTH ALONG SFC BOUNDARY ALTHO MAY WEAKEN AS INSTABILITY IS WANING.
ADDITIONAL DEVELOPMENT IS OCCURRING TO THE WEST ACROSS N IL MORE
CLOSELY TIED TO UPPER SYSTEM. THIS WILL CONTINUE TO EXPAND INTO THE
AREA THROUGHOUT THE MORNING AND INTO THE AFTERNOON HOURS. NORTHWARD
SURGE OF MOISTURE IN LOWER LEVELS WITH PWATS IN EXCESS OF 1.7-1.9
AND CONVERGENCE WILL AID IN THE DEVELOPMENT OF ADDITIONAL CONVECTION
WITH THE CHANCES FOR NEEDED RAINFALL LOOKING PRETTY WIDESPREAD.
THUNDER COVERAGE MAY BE SOMEWHAT LIMITED BY MARGINAL INSTABILITY
GIVEN THE FACT THAT CLOUD COVER MAY HINDER DESTABILIZATION. THIS AS
WELL AS WEAK SHEAR VALUES SHOULD KEEP THE STORMS NON-SEVERE.
REGARDLESS....RAINFALL AMOUNTS MAY EXCEED 1" IN SOME LOCATIONS GIVEN
AMPLE MOISTURE AND SLOW MOVEMENT OF STORMS. MODELS IN DECENT
AGREEMENT WITH TRACK OF SYSTEM AND LATEST HRRR RUNS ARE ACTUALLY
HANDLING CURRENT SITUATION WELL. HAVE TRIED TO INCORPORATE TIMING
AND COVERAGE INTO POP/WX GRIDS WHICH RESULTED IN SLIGHT ADJUSTMENT
TO PREVIOUS GRIDS. SHOWERS MAY LINGER INTO TONIGHT DUE TO PROXIMITY
OF UPPER TROF ROTATING THRU AREA.
HIGHS TODAY WILL BE SOME 5-10 DEGREES COOLER THAN SUNDAY...GENERALLY
IN THE UPPER 70S. OVERNIGHT LOWS WILL BE IN THE 60S.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 344 AM EDT MON AUG 11 2014
ON TUESDAY...A STRONG UPPER VORT MAX WILL BE DROPPING INTO THE
SOUTHERN GREAT LAKES REGION TO START THE DAY WITH AN ASSOCIATED
SECONDARY WEAK SFC TROUGH ACCOMPANYING THIS FORCING.
MEANWHILE...MID/UPPER LEVEL TROUGH ACROSS NORTHERN OHIO WILL BE
DEPARTING TO THE EAST WITH PERHAPS SOME CONTINUED SCATTERED RAIN
SHOWERS IN THE EARLY MORNING IN DEPARTING DEFORMATION ZONE WITH THIS
FEATURE. GIVEN THESE TWO FORCING MECHANISMS HAVE MAINTAINED LOW TO
MID CHANCE POPS IN THE MORNING...BUT LOW LEVEL DRY AIR ADVECTION
WILL DEVELOP IN THE WAKE OF THIS FEATURE FROM WEST TO EAST FROM MID
MORNING INTO THE AFTERNOON HOURS. INHERITED POP GRADIENT DIMINISHING
FROM WEST TO EAST DURING THE AFTERNOON STILL APPEARS REASONABLE
GIVEN THE ABOVE...AND WHILE WIDESPREAD MEASURABLE PRECIP IS NOT
EXPECTED BY AFTERNOON...SOME PATCHY DRIZZLE MAY DEVELOP AS DRY SLOT
LIFTS INTO THE AREA. GIVEN CAA...LOW CLOUDS...AND PRECIP HAVE
MAINTAINED HIGHS FROM PREVIOUS FORECAST IN THE 70 TO 75 DEGREE
RANGE. POTENTIAL OF THUNDER STILL APPEARS TO BE QUITE MINIMAL WITH
AXIS OF WEAK INSTABILITY SHIFTING INTO OHIO TOWARD MIDDAY.
SEVERAL SMALLER SCALE VORTS ROTATING CYCLONICALLY AROUND DEEPENING
PARENT UPPER TROUGH MAY ALLOW FOR A SLOW ENOUGH EVOLUTION OF
MID/UPPER TROUGH AXIS TO KEEP SOME ISOLD/SCT LIGHT RAIN SHOWERS
ACROSS NORTHWEST OHIO DURING THE EARLY EVENING HOURS TUESDAY...BUT
THIS SHOULD BE FOLLOWED BY A DIMINISHING CLOUD TREND DURING THE
REMAINDER OF THE OVERNIGHT. STILL SOME LOWER CONFIDENCE ON TEMPS
TUESDAY NIGHT WITH EFFECTS OF COOLER AIRMASS ADVECTING INTO THE AREA
POSSIBLY PARTIALLY OFFSET IF LOW CLOUDS HANG ON LONGER THAN
EXPECTED...AND BY MODEST LOW LEVEL HEIGHT GRADIENT.
QUIET CONDITIONS ARE THEN EXPECTED FOR THE WED-FRI TIMEFRAME WITH
SOME INDICATIONS OF ANOTHER WEAK SFC TROUGH/REINFORCING COLD FRONT
BY THE THURSDAY TIMEFRAME. STRONG SUBSIDENCE ON WEDNESDAY AND BETTER
CHANCES OF INSOLATION COULD ALLOW FOR SOME RECOVERY OF AFTERNOON
HIGHS INTO THE MID AND UPPER 70S BEFORE SLIGHTLY COOLER AIR ADVECTS
INTO THE AREA AGAIN ON THURSDAY. WILL KEEP THIS WEAK FROPA
DRY...WITH LACK OF ANY SIGNIFICANT DEEP MOISTURE.
MEDIUM RANGE MODELS HAVE LACKED CONSISTENCY WITH TREND TO A MORE
DEAMPLIFIED FLOW PATTERN BY NEXT WEEKEND...WITH PRECIP CHANCES FOR
SATURDAY NOW LOOKING A LITTLE MORE QUESTIONABLE AND PERHAPS DELAYED.
GIVEN THIS RUN TO RUN INCONSISTENCY HAVE OPTED TO MAKE NO CHANGES TO
POPS FOR SAT/SUN AT THIS TIME AND LET FUTURE SHIFTS ASSESS
POSSIBILITY OF REMOVING SAT POPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 108 AM EDT MON AUG 11 2014
TRICKY FORECAST FOR THE TAF PERIOD AS MORE ACTIVE WEATHER NEARS
THE AREA. MVFR CONDITIONS LIKELY FOR MOST OF THE PERIOD WITH
FLUCTUATIONS POSSIBLE. WINDS WILL GENERALLY BE BELOW 10 KTS BACKING
FROM THE EAST TO NNW BY THE END OF THE PERIOD.
WEAK SFC LOW ACROSS CENTRAL IN WILL SHIFT NE TODAY AS SHORTWAVE
CURRENTLY ACROSS MISSOURI/IOWA WILL BEGIN TO PHASE WITH UPPER
LEVEL TROF THAT WILL SWING THRU THE AREA TONIGHT INTO TUES. THIS
WILL ALLOW FOR NORTHWARD SURGE OF MOISTURE AND THE RETURN OF SOME
WEAK INSTABILITY. AREA OF SHOWERS AND MVFR BR CURRENTLY ACROSS
CENTRAL IN WILL AFFECT KFWA OVER THE NEXT FEW HOURS WITH CURRENT VFR
CONDITIONS DETERIORATING TO MVFR. ANOTHER AREA OF SHOWERS POPPING
UP TO THE WEST OF SBN WILL AFFECT THE TERMINAL AFTER 9Z. MORE
ROBUST PERIOD OF SHOWERS AND ISOLATED THUNDERSTORMS POSSIBLE
DURING THE DAY AND INTO THE LATE AFTERNOON/EVENING HOURS AT BOTH
TERMINALS AS SYSTEM MOVES THRU. BRIEF PERIOD OF IFR CONDITIONS
POSSIBLE IN ANY OF THE HEAVIER SHOWERS/TSRA BUT PINPOINTING TIMING
AND LOCATION AT THIS POINT IS TOO UNCERTAIN FOR INCLUSION. THIS
WILL NEED TO BE MONITORED FOR FUTURE ISSUANCES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...CEO
SHORT TERM...CEO
LONG TERM...MARSILI
AVIATION...CEO
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
528 PM MDT TUE AUG 12 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 152 PM MDT TUE AUG 12 2014
A RIDGE WILL BE OVER THE ROCKIES TONIGHT AND A SURFACE TROUGH OVER
EASTERN COLORADO. SOME SCATTERED CUMULUS HAVE DEVELOPED OVER
EASTERN COLORADO. CURRENT RADAR WITH NO RETURNS. THE HRRR AND NAM
BOTH DO NOT INDICATE STORMS FOR THIS EVENING AND THAT SEEMS
REASONABLE BASED ON VERY DRY FORECAST SOUNDINGS OVER THE AREA.
ALSO WATER VAPOR IMAGERY SHOWING STRONG SUBSIDENCE EAST OF THE
CENTRAL ROCKIES. POPS WILL BE NIL TONIGHT AND AGAIN ON WEDNESDAY
AS SUBSIDENCE CONTINUES. LOW TEMPERATURES TONIGHT WILL BE IN THE
LOWER 60S AND MAX TEMPERATURES WEDNESDAY AROUND 90.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 152 PM MDT TUE AUG 12 2014
A DRY FORECAST CONTINUES THROUGH WEDNESDAY NIGHT AND EARLY THURSDAY
AS THE RIDGE AND SUBSIDENCE CONTINUES OVER THE HIGH PLAINS. BY
THURSDAY AFTERNOON THE RIDGE BREAKS DOWN SOME AS A SHORTWAVES
MOVES INTO THE AREA. THIS SHORTWAVE WILL CONTINUE MOVING ACROSS
THE FA THURSDAY NIGHT INTO FRIDAY MORNING. STORMS SHOULD INITIATE
ON A SURFACE TROUGH IN EASTERN COLORADO THURSDAY AFTERNOON AND
THEN SPREAD EAST ACROSS THE REST OF THE FA THURSDAY NIGHT. CHANCE
POPS LOOK GOOD FOR THIS EVENT. STORMS WILL LIKELY LINGER IN THE
EASTERN FA EARLY FRIDAY MORNING WITH SUBSIDENCE MOVING INTO THE FA
FROM WEST TO EAST. CONFIDENCE IS NOT HIGH FOR STORMS FRIDAY
AFTERNOON BUT CANNOT RULE OUT AT LEAST AN ISOLATED STORM OR TWO SO
WILL LOWER POPS TO SLIGHT CHANCE.
IN THE EXTENDED...FROM FRIDAY NIGHT THROUGH TUESDAY...A BROAD
RIDGE WILL BE OVER THE WESTERN CONUS EXTENDING INTO THE HIGH
PLAINS. NUMEROUS WEAK DISTURBANCES WILL MOVE THROUGH THE RIDGE
INTO THE HIGH PLAINS. THIS WILL PROVIDE POTENTIAL FOR STORMS EACH
AFTERNOON AND EVENING ACROSS THE FA THROUGH TUESDAY. CONSEQUENTLY, PLAN
TO HAVE AT LEAST A SLIGHT CHANCE OF STORMS EACH DAY. MAX
TEMPERATURES WILL REACH THE LOWER 90S EACH DAY. MIN TEMPERATURES
WILL BE IN THE LOWER TO MID 60S.
&&
.AVIATION...
526 PM MDT TUE AUG 12 2014
FOR THE 00Z TAFS AT KGLD AND KMCK...VFR THROUGH THE PERIOD.
EAST/SOUTHEAST WINDS AT BOTH TERMINALS UNDER 10KTS THROUGH 15Z
BEFORE INCREASING TOWARD 15KTS AFTER 15Z WEDNESDAY. ONLY SOME HIGH
CIRRUS CLOUDS EXPECTED TOWARD THE END OF THE PERIOD.
DDT
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1048 AM MDT MON AUG 11 2014
.UPDATE...
ISSUED AT 526 AM MDT MON AUG 11 2014
ADDED MENTION OF PATCHY FOG TO NORTHERN PART OF CWA BASED ON
CURRENT OBS ALONG REPUBLICAN RIVER VALLEY. CURRENTLY NOT REALLY
CONFIDENT ON EXTENT OF FOG...SO KEPT COVERAGE/MENTION IN LINE WITH
LATEST SHORT RANGE GUIDANCE/OBS WITH DISSIPATION EXPECTED BY MID
MORNING WHEN DAYTIME HEATING WILL ERODE FOG.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 254 AM MDT MON AUG 11 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW AMPLIFIED RIDGE
ACROSS INTER-MOUNTAIN WEST...WITH NW FLOW FROM CANADA...ACROSS THE
NORTHERN PLAINS INTO THE SOUTHERN MISSISSIPPI VALLEY. AT THE SURFACE
HIGH PRESSURE IS IN PLACE ACROSS THE NORTHERN AND HIGH PLAINS.
TODAY...PRECIP SIGNAL NOT PARTICULARITY STRONG WITH VERY LITTLE IN
THE WAY OF LARGE SCALE FORCING AS RIDGE IS BEGINNING TO HOLD A
STRONGER INFLUENCE OVER OUR CWA. THERE SHOULD BE ENOUGH
INSTABILITY/MOISTURE IN PLACE THIS AFTERNOON THAT AS CONVECTIVE
TEMPS ARE APPROACHED ACROSS THE SW AND WESTERN PART OF THE CWA
THIS AFTERNOON WE COULD SEE A FEW STORMS DEVELOP AND START TO
SLOWLY ADVECT EAST-SOUTHEAST. HAVE KEPT SLIGHT CHANCE POPS IN
PLACE TIED DIURNAL HEATING THIS AFTERNOON/EVENING. SEVERE WEATHER
PARAMETERS (ESPECIALLY SHEER) ARE NOT IMPRESSIVE...SO AM NOT
THINKING WE SHOULD SEE AN ELEVATED SEVERE THREAT. WITH NW FLOW AND
SIMILAR AIR MASS IN PLACE I EXPECT HIGHS TO BE SIMILAR TO SUNDAY
WITH VALUES GENERALLY AROUND THE MID 80S.
TUESDAY-WEDNESDAY...AS H5 RIDGE SHIFTS FURTHER EAST SUBSIDENCE AND
DEEP DRY WILL LIKELY LIMIT THUNDERSTORM POTENTIAL. GUIDANCE HAS
REALLY BACKED OFF ON PRECIP SIGNAL OVER OUR CWA...SO I KEPT MENTION
OF POPS OUT THROUGH WEDNESDAY AFTERNOON. TEMPERATURES SHOULD BE BACK
TO SEASONAL NORMALS IN THE UPPER 80S/AROUND 90 BY TUESDAY...WITH
EVEN WARMER TEMPS ON WED. WARMEST GUIDANCE COULD ACTUALLY SUPPORT
UPPER 90S/NEAR 100F. I DECIDED AGAINST GOING THAT WARM WITH
CONSENSUS FAVORING THE LOWER END OF GUIDANCE IN THE LOW-MID 90S.
WEDNESDAY NIGHT...WEAK FORCING ASSOCIATED WITH A VORT MAX ROUNDING
THE NORTHERN PART OF THE RIDGE COULD COMBINE WITH GOOD INSTABILITY
TO SUPPORT THUNDERSTORM DEVELOPMENT ACROSS THE NORTHERN PART OF THE
CWA...HOWEVER AIR MASS CONTINUE TO BE VERY DRY SO CONFIDENCE WAS NOT
HIGH ENOUGH TO INCLUDE HIGHER THAN SLIGHT CHANCE MENTION.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 254 AM MDT MON AUG 11 2014
AN UPPER LEVEL RIDGE AT THE START OF THE EXTENDED PERIOD WILL WEAKEN
AS A SHORTWAVE TROUGH TRANSITIONS EASTWARD THROUGH THE CENTRAL
ROCKIES. SOME TIMING DIFFERENCES EXIST IN THE MODELS WITH GFS BEING
FASTER THAN ECMWF. COVERAGE OF CONVECTION SHOULD INCREASE BY LATE
THURSDAY WITH SLIGHT TO LOW CHANCE POPS CONTINUING INTO FRIDAY AS
THE SHORTWAVE SLOWLY MOVES SOUTH. THEREAFTER UPPER LEVEL RIDGING
GRADUALLY BUILDS AGAIN PER MEDIUM RANGE CONSENSUS THOUGH WEAK
SHORTWAVES IN WESTERLY/NORTHWESTERLY FLOW NECESSITATE INCLUSION OF
SLIGHT CHANCE POPS THROUGH THE WEEKEND. TEMPERATURES SHOULD REMAIN
NEAR OR SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1047 AM MDT MON AUG 11 2014
A BAND OF CUMULUS CLOUDS DEVELOPED ACROSS SOUTHWEST NEBRASKA...SO
INCLUDED SCATTERED CLOUDS AT KMCK THROUGH THE AFTERNOON. ALTHOUGH
THE AIR MASS WILL BE UNSTABLE ENOUGH TO SUPPORT CONVECTION OVER
SOUTHWEST NEBRASKA THIS AFTERNOON...THE CHANCE IS TOO LITTLE TO
INCLUDE IN TAF. THEREFORE...VFR CONDITIONS WILL CONTINUE AT KGLD
AND KMCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...BRB
AVIATION...MENTZER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
529 AM MDT MON AUG 11 2014
.UPDATE...
ISSUED AT 526 AM MDT MON AUG 11 2014
ADDED MENTION OF PATCHY FOG TO NORTHERN PART OF CWA BASED ON
CURRENT OBS ALONG REPUBLICAN RIVER VALLEY. CURRENTLY NOT REALLY
CONFIDENT ON EXTENT OF FOG...SO KEPT COVERAGE/MENTION IN LINE WITH
LATEST SHORT RANGE GUIDANCE/OBS WITH DISSIPATION EXPECTED BY MID
MORNING WHEN DAYTIME HEATING WILL ERODE FOG.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 254 AM MDT MON AUG 11 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW AMPLIFIED RIDGE
ACROSS INTER-MOUNTAIN WEST...WITH NW FLOW FROM CANADA...ACROSS THE
NORTHERN PLAINS INTO THE SOUTHERN MISSISSIPPI VALLEY. AT THE SURFACE
HIGH PRESSURE IS IN PLACE ACROSS THE NORTHERN AND HIGH PLAINS.
TODAY...PRECIP SIGNAL NOT PARTICULARITY STRONG WITH VERY LITTLE IN
THE WAY OF LARGE SCALE FORCING AS RIDGE IS BEGINNING TO HOLD A
STRONGER INFLUENCE OVER OUR CWA. THERE SHOULD BE ENOUGH
INSTABILITY/MOISTURE IN PLACE THIS AFTERNOON THAT AS CONVECTIVE
TEMPS ARE APPROACHED ACROSS THE SW AND WESTERN PART OF THE CWA
THIS AFTERNOON WE COULD SEE A FEW STORMS DEVELOP AND START TO
SLOWLY ADVECT EAST-SOUTHEAST. HAVE KEPT SLIGHT CHANCE POPS IN
PLACE TIED DIURNAL HEATING THIS AFTERNOON/EVENING. SEVERE WEATHER
PARAMETERS (ESPECIALLY SHEER) ARE NOT IMPRESSIVE...SO AM NOT
THINKING WE SHOULD SEE AN ELEVATED SEVERE THREAT. WITH NW FLOW AND
SIMILAR AIR MASS IN PLACE I EXPECT HIGHS TO BE SIMILAR TO SUNDAY
WITH VALUES GENERALLY AROUND THE MID 80S.
TUESDAY-WEDNESDAY...AS H5 RIDGE SHIFTS FURTHER EAST SUBSIDENCE AND
DEEP DRY WILL LIKELY LIMIT THUNDERSTORM POTENTIAL. GUIDANCE HAS
REALLY BACKED OFF ON PRECIP SIGNAL OVER OUR CWA...SO I KEPT MENTION
OF POPS OUT THROUGH WEDNESDAY AFTERNOON. TEMPERATURES SHOULD BE BACK
TO SEASONAL NORMALS IN THE UPPER 80S/AROUND 90 BY TUESDAY...WITH
EVEN WARMER TEMPS ON WED. WARMEST GUIDANCE COULD ACTUALLY SUPPORT
UPPER 90S/NEAR 100F. I DECIDED AGAINST GOING THAT WARM WITH
CONSENSUS FAVORING THE LOWER END OF GUIDANCE IN THE LOW-MID 90S.
WEDNESDAY NIGHT...WEAK FORCING ASSOCIATED WITH A VORT MAX ROUNDING
THE NORTHERN PART OF THE RIDGE COULD COMBINE WITH GOOD INSTABILITY
TO SUPPORT THUNDERSTORM DEVELOPMENT ACROSS THE NORTHERN PART OF THE
CWA...HOWEVER AIR MASS CONTINUE TO BE VERY DRY SO CONFIDENCE WAS NOT
HIGH ENOUGH TO INCLUDE HIGHER THAN SLIGHT CHANCE MENTION.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 254 AM MDT MON AUG 11 2014
AN UPPER LEVEL RIDGE AT THE START OF THE EXTENDED PERIOD WILL WEAKEN
AS A SHORTWAVE TROUGH TRANSITIONS EASTWARD THROUGH THE CENTRAL
ROCKIES. SOME TIMING DIFFERENCES EXIST IN THE MODELS WITH GFS BEING
FASTER THAN ECMWF. COVERAGE OF CONVECTION SHOULD INCREASE BY LATE
THURSDAY WITH SLIGHT TO LOW CHANCE POPS CONTINUING INTO FRIDAY AS
THE SHORTWAVE SLOWLY MOVES SOUTH. THEREAFTER UPPER LEVEL RIDGING
GRADUALLY BUILDS AGAIN PER MEDIUM RANGE CONSENSUS THOUGH WEAK
SHORTWAVES IN WESTERLY/NORTHWESTERLY FLOW NECESSITATE INCLUSION OF
SLIGHT CHANCE POPS THROUGH THE WEEKEND. TEMPERATURES SHOULD REMAIN
NEAR OR SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 526 AM MDT MON AUG 11 2014
FOG HAS DEVELOPED OVER PORTIONS OF SW NEBRASKA...AND VIS BETWEEN 5
TO 7 SM WILL BE POSSIBLE AT TIME AT KMCK. I CANT COMPLETELY RULE
OUT VIS DROPPING LOWER THAN THIS...HOWEVER SHORT RANGE GUIDANCE
AND AREA OBS ARE NOT SUPPORTIVE OF LOWER CONDITIONS. VFR CONDITIONS
SHOULD PERSIST AT KGLD. WINDS WILL REMAIN LIGHT AROUND 5 KT
THROUGH THE TAF PERIOD WITH NORTHERLY WINDS EVENTUALLY SHIFTING TO
THE SOUTHEAST THIS EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...DR
SHORT TERM...DR
LONG TERM...BRB
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
255 AM MDT MON AUG 11 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 254 AM MDT MON AUG 11 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW AMPLIFIED RIDGE
ACROSS INTER-MOUNTAIN WEST...WITH NW FLOW FROM CANADA...ACROSS THE
NORTHERN PLAINS INTO THE SOUTHERN MISSISSIPPI VALLEY. AT THE SURFACE
HIGH PRESSURE IS IN PLACE ACROSS THE NORTHERN AND HIGH PLAINS.
TODAY...PRECIP SIGNAL NOT PARTICULARITY STRONG WITH VERY LITTLE IN
THE WAY OF LARGE SCALE FORCING AS RIDGE IS BEGINNING TO HOLD A
STRONGER INFLUENCE OVER OUR CWA. THERE SHOULD BE ENOUGH
INSTABILITY/MOISTURE IN PLACE THIS AFTERNOON THAT AS CONVECTIVE
TEMPS ARE APPROACHED ACROSS THE SW AND WESTERN PART OF THE CWA
THIS AFTERNOON WE COULD SEE A FEW STORMS DEVELOP AND START TO
SLOWLY ADVECT EAST-SOUTHEAST. HAVE KEPT SLIGHT CHANCE POPS IN
PLACE TIED DIURNAL HEATING THIS AFTERNOON/EVENING. SEVERE WEATHER
PARAMETERS (ESPECIALLY SHEER) ARE NOT IMPRESSIVE...SO AM NOT
THINKING WE SHOULD SEE AN ELEVATED SEVERE THREAT. WITH NW FLOW AND
SIMILAR AIR MASS IN PLACE I EXPECT HIGHS TO BE SIMILAR TO SUNDAY
WITH VALUES GENERALLY AROUND THE MID 80S.
TUESDAY-WEDNESDAY...AS H5 RIDGE SHIFTS FURTHER EAST SUBSIDENCE AND
DEEP DRY WILL LIKELY LIMIT THUNDERSTORM POTENTIAL. GUIDANCE HAS
REALLY BACKED OFF ON PRECIP SIGNAL OVER OUR CWA...SO I KEPT MENTION
OF POPS OUT THROUGH WEDNESDAY AFTERNOON. TEMPERATURES SHOULD BE BACK
TO SEASONAL NORMALS IN THE UPPER 80S/AROUND 90 BY TUESDAY...WITH
EVEN WARMER TEMPS ON WED. WARMEST GUIDANCE COULD ACTUALLY SUPPORT
UPPER 90S/NEAR 100F. I DECIDED AGAINST GOING THAT WARM WITH
CONSENSUS FAVORING THE LOWER END OF GUIDANCE IN THE LOW-MID 90S.
WEDNESDAY NIGHT...WEAK FORCING ASSOCIATED WITH A VORT MAX ROUNDING
THE NORTHERN PART OF THE RIDGE COULD COMBINE WITH GOOD INSTABILITY
TO SUPPORT THUNDERSTORM DEVELOPMENT ACROSS THE NORTHERN PART OF THE
CWA...HOWEVER AIR MASS CONTINUE TO BE VERY DRY SO CONFIDENCE WAS NOT
HIGH ENOUGH TO INCLUDE HIGHER THAN SLIGHT CHANCE MENTION.
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 254 AM MDT MON AUG 11 2014
AN UPPER LEVEL RIDGE AT THE START OF THE EXTENDED PERIOD WILL WEAKEN
AS A SHORTWAVE TROUGH TRANSITIONS EASTWARD THROUGH THE CENTRAL
ROCKIES. SOME TIMING DIFFERENCES EXIST IN THE MODELS WITH GFS BEING
FASTER THAN ECMWF. COVERAGE OF CONVECTION SHOULD INCREASE BY LATE
THURSDAY WITH SLIGHT TO LOW CHANCE POPS CONTINUING INTO FRIDAY AS
THE SHORTWAVE SLOWLY MOVES SOUTH. THEREAFTER UPPER LEVEL RIDGING
GRADUALLY BUILDS AGAIN PER MEDIUM RANGE CONSENSUS THOUGH WEAK
SHORTWAVES IN WESTERLY/NORTHWESTERLY FLOW NECESSITATE INCLUSION OF
SLIGHT CHANCE POPS THROUGH THE WEEKEND. TEMPERATURES SHOULD REMAIN
NEAR OR SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1134 PM MDT SUN AUG 10 2014
VFR CONDITIONS AND LIGHT WINDS SHOULD CONTINUE FOR THE NEXT 24
HOURS. WINDS ARE CALM ACROSS THE REGION PRESENTLY. TEMPERATURES
FELL OFF QUICKLY AND WITH DEWPOINTS IN THE LOW 60S...HAVE A LITTLE
HESITATION THAT THERE MAY BE SOME PATCHY FOG DEVELOPMENT. DID NOT
FEEL CONFIDENT ENOUGH TO PLACE IN TAF WITH HIGH CLOUDS COMING OVER
AND TEMPS RISING 1-2 DEGREES AT KGLD. MODEL GUIDANCE DOES NOT
INDICATE FOG WITH ONLY THE HRRR INDICATING VIS POSSIBLY REACHING 5
MILES. FOR THIS AFTERNOON...A FEW SHOWERS AND STORMS COULD DEVELOP
BUT MOST ACTIVITY SHOULD BE CONFINED TO COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1134 PM MDT SUN AUG 10 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 108 PM MDT SUN AUG 10 2014
UPPER FLOW WILL BE NORTHWEST TONIGHT AND MONDAY. SURFACE HIGH
PRESSURE WILL MOVE SOUTH INTO THE CENTRAL PLAINS. OTHER THAN A
SLIGHT CHANCE OF THUNDERSTORMS NEAR THE FRONT OVER WESTERN PORTIONS
OF CHEYENNE AND KIT CARSON COUNTIES IN COLORADO THIS EVENING, POPS WILL BE
NIL. THE NAM SHOWS SOME QPF OVER THE EASTERN FA MONDAY AFTERNOON
BUT FORCING IS VERY WEAK SO WILL ONLY CARRY SILENT POPS.
MIN TEMPERATURES TONIGHT WILL COOL TO AROUND 60. MAX TEMPERATURES
MONDAY WILL RISE TO THE MID 80S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 408 PM MDT SUN AUG 10 2014
UPPER RIDGE CENTERED OVER THE ROCKIES WILL SUPPRESS MOST
CONVECTION THROUGH MID WEEK. CANNOT RULE OUT AN ISOLATED TO WIDELY
SCATTERED STORM UNDER THE RIDGE AS CIN ERODES IN THE
AFTERNOON...BUT SHOULD BE CONFINED MAINLY IN EASTERN COLORADO
WHERE STORMS HAVE A BETTER CHANCE OF MIGRATING OFF THE FRONT
RANGE. BETTER CHANCES FOR PRECIPITATION RETURNS BEGINNING ON
THURSDAY THROUGH THE REMAINDER OF THE LONG TERM PERIOD AS THE
UPPER RIDGE BREAKS DOWN AND A SERIES OF DISTURBANCES MOVES
THROUGH. TEMPERATURES WILL BE NEAR TO SLIGHTLY ABOVE NORMAL
THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1134 PM MDT SUN AUG 10 2014
VFR CONDITIONS AND LIGHT WINDS SHOULD CONTINUE FOR THE NEXT 24
HOURS. WINDS ARE CALM ACROSS THE REGION PRESENTLY. TEMPERATURES
FELL OFF QUICKLY AND WITH DEWPOINTS IN THE LOW 60S...HAVE A LITTLE
HESITATION THAT THERE MAY BE SOME PATCHY FOG DEVELOPMENT. DID NOT
FEEL CONFIDENT ENOUGH TO PLACE IN TAF WITH HIGH CLOUDS COMING OVER
AND TEMPS RISING 1-2 DEGREES AT KGLD. MODEL GUIDANCE DOES NOT
INDICATE FOG WITH ONLY THE HRRR INDICATING VIS POSSIBLY REACHING 5
MILES. FOR THIS AFTERNOON...A FEW SHOWERS AND STORMS COULD DEVELOP
BUT MOST ACTIVITY SHOULD BE CONFINED TO COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...JDK
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
934 PM EDT Tue Aug 12 2014
...Forecast Update...
Issued at 930 PM EDT Tue Aug 12 2014
Updating products to remove shower wording over the northeast. Had a
few small cells move just northeast of the region, but nothing is
going on in our area at this time. Some drier air is working into
the area, but with winds dying down, we should see some sites drop
into the upper 50s. This could be low enough for a few patches of
fog to develop toward daybreak, so have that still in for all but
the Bluegrass. Up there, we should see a swath of clouds come in
from the northwest, in association with an upper trough axis
swinging through the region. Latest RUC shows the clouds there may
break up briefly after midnight, but redevelop toward daybreak. Will
lean this way and keep sky grids in the partly cloudy range through
the night.
.SHORT TERM (Now through Wednesday Night)...
Issued at 250 PM EDT Tue Aug 12 2014
A cold front has pushed through the region this afternoon. This
front along with cloud cover associated with an upper trough and the
front have kept our temps at bay in the upper 70s and lower 80s
today. Congested cu from the upper trough will continue to sweep
across our southern Indiana and extreme northern Kentucky counties
possibly causing an isld sprinkle or brief shower this evening.
However, the rest of the night looks dry with the upper trough
moving NE from the Great Lakes into southeast Canada. Drier air
will continue to advect in from the NW so don`t think fog will be a
big issue tonight. However, could see some patchy light fog in fog
prone areas of the east central KY towards morning where low levels
will remain a bit more saturated. Low temps will be in the upper
50s/lower 60s.
For Wednesday, expect a dry, cooler than normal day. Mostly sunny
skies will be the rule as sfc high pressure builds in from the
west. High temps should range from 77-82.
Wednesday night should be a decent rad cooling night under mostly
clear skies. A weak upper level impulse may approach from the north
late Wed night/Thurs morning which may create a more mixy
environment limiting fog potential. Still feel that at least patchy
fog is possible in our fog prone areas though with mostly clear
skies, good subsidence, and very light or calm winds for a good
portion of the night. Expect low temps in the mid 50s to lower 60s.
.LONG TERM (Thursday through Tuesday)...
Issued at 247 PM EDT Tue Aug 12 2014
The long term period will start out with somewhat cooler and drier
weather before a return to higher temps and scattered rain chances.
Through Sunday the upper level trough over the eastern CONUS will
slowly shift off to the northeast. This will keep us in
northwesterly flow aloft. High pressure at the surface will be
building in Thursday and slowly shift off to the east through the
weekend.
There is just a bit of uncertainty in the Thursday forecast as a
vortmax will dive through the northwesterly flow and models try to
develop very light and isolated showers. However, with the high
pressure building in and a drier airmass, will keep the forecast dry
for now. Dry weather will continue through Saturday. Highs will be
in the lower to mid 80s Thursday and Friday with a warm up to the
mid to upper 80s on Saturday. Lows will range from the upper 50s to
mid 60s.
By the end of the weekend, the models develop a stronger shortwave
in the upper level flow. this will bring a better chance for precip
Sunday into Monday. The models show a difference in timing with this
wave, so for now will keep pops in the 20-30% range. Another system
will bring a second round of precipitation Monday into Tuesday.
Temperatures will be close to seasonal normals for this time of year
with highs in the mid to upper 80s and lows in the upper 60s to
lower 70s.
&&
.AVIATION (00Z TAF Update)...
Issued at 725 PM EDT Tue Aug 12 2014
Gusty west northwest winds, in the wake of today`s cold front,
should die down soon with the setting sun. Have some stratus
approaching the northern terminals from the north as an upper trough
axis is about to swing through the region. If the thickest part of
these clouds survive into the drier air into our region, KSDF and
KLEX may briefly see high-end MVFR cigs between now and around
midnight. After that subsidence should win out and dissipate those
clouds. Looking toward early Wednesday morning, models still show
KLEX taking longer to dry out than the other sites, and with cooler
temperatures coming in, have kept in what previous forecaster had
for MVFR conditions. There is some question as to how long these
clouds will linger into Wednesday, but for now have things improving
by mid morning, with VFR conditions the rest of the period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........RJS
Short Term.....AMS
Long Term......EER
Aviation.......RJS
AREA FORECAST DISCUSSION
NWS JACKSON KY
339 PM EDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 339 PM EDT MON AUG 11 2014
CURRENT CONDITIONS ACROSS THE REGION FEATURE AN AREA OF SHOWERS AND
THUNDERSTORMS MOVING THROUGH THE AREA ALONG THE EASTERN COUNTIES
BORDERING VA. THIS ACTIVITY WAS TIED TO A POTENT UPPER LEVEL TROUGH
MOVING THROUGH. OUT WEST...THE ANOTHER PREFRONTAL TROUGH STILL NEEDS
TO SWING THROUGH THE AREA TONIGHT AND WILL DO SO AFTER 00Z TONIGHT.
ALONG AND AHEAD OF THE BOUNDARY...SOME SHOWERS AND STORMS WILL MOVE
BACK INTO EASTERN KENTUCKY THIS EVENING AND TONIGHT. THOUGH THIS WILL
NOT BE AS STRONG AS THE EARLIER AS THE CELLS EARLIER BUT...ADDITIONAL
RAINFALL MAY BE ENOUGH TO CAUSE SOME MINOR FLOODING OVER AREAS THAT
GOT RAIN EARLIER TODAY. EXPECT A LULL IN THE ACTIVITY LATER TONIGHT
AS MOST OF THE INSTABILITY WANES.
HEADING INTO TOMORROW...WITH THE COLD FRONT STILL TO PUSH
THROUGH AND WILL SWING THROUGH BY TUESDAY EVENING AND WILL ALLOW FOR
SOME THUNDERSTORM DEVELOPMENT TUESDAY AFTERNOON. WITH THE STRONGEST
SUPPORT BEING IN THE NORTH WITH THE TROUGH AXIS...THERE WILL BE A
BETTER CHANCE FOR STRONG TO POSSIBLY SEVERE THUNDERSTORM DEVELOPMENT.
MODEL SOUNDING WOULD SUGGEST TO THIS WITH AN ACTUAL DRY LAYER PUSHED
IN BEHIND THIS ANTICIPATED ACTIVITY. WILL HIGHLIGHT THIS THREAT IN
THE HWO AS WELL. MODELS HAVE BEEN AT LEAST REASONABLE WITH THIS SET
OVER THE PAST COUPLE OF DAYS AND ESPECIALLY THE NAM AND HRRR HAVE
BEEN VERIFYING REASONABLY.
FOR TUESDAY NIGHT...THE FRONT STANDS TO PUSH THE WHOLE WAY THROUGH
EASTERN KENTUCKY BY 06Z TUESDAY NIGHT. WITH SUBSIDENCE
OVERHEAD...CLEARING SKIES...AND COOLING TEMPS...DENSE FOG WILL BE AN
ISSUE COME TUESDAY NIGHT. IN FACT THE FOG COULD BE WIDE SPREAD. WILL
HIGHLIGHT THIS IN THE HWO AS WELL.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 339 PM EDT MON AUG 11 2014
THE EXTENDED FORECAST PERIOD BEGINS ON WEDNESDAY WITH A DEEP TROUGH
OVER THE EASTERN CONUS AND AN AMPLIFIED RIDGE OVER THE WESTERN CONUS.
DESPITE SOME SHIFTING IN THE UPPER LEVEL RIDGE OVER THE WEST...AN
OVERALL AMPLIFIED MERIDIONAL PATTERN WILL BE IN PLACE THROUGH THE
EXTENDED. THIS PATTERN IS A TAD BIT RARE FOR THIS TIME OF YEAR.
HOWEVER...BY THE LAST DAY OF THE EXTENDED. THE PATTERN HAS BROKEN
DOWN AS A SHORT WAVE TROUGH MOVES OVER THE RIDGE AND WEAKENS IT. THIS
WILL BRING THIS FEATURE OVER THE AREA BY THE END OF THE EXTENDED.
WITH THE GFS AND EURO SHOWING SOME DECENT AGREEMENT...LITTLE CHANGES
WERE NEEDED TO THE ALL MODEL BLEND SOLUTION.
FOR SOME DETAILS IN THE LOWER LEVELS...THE SURFACE COLD FRONT THAT
IMPACTED THE AREA INTO TUESDAY EVENING AND TUESDAY NIGHT...WILL PUSH
OFF TO THE EAST BRINGING SURFACE HIGH PRESSURE INTO THE AREA FOR
WEDNESDAY THROUGH SATURDAY KEEPING A PERIOD OF DRIER AND COOLER
WEATHER OVER EASTERN KENTUCKY. IN FACT...BEFORE TEMPERATURES MODERATE
INTO THE MID 80S ON SATURDAY...HIGH TEMPERATURES ON WEDNESDAY THROUGH
FRIDAY WILL BE 5 TO 7 DEGREES BELOW AVERAGE. IN SHORT...THE OVERALL
COOLER SUMMER CONTINUES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 128 PM EDT MON AUG 11 2014
SHOWERS AND THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL WILL BE THE
PRIMARY WEATHER ISSUE FOR THE AREA THROUGH THE TAF PERIOD AND AS
SUCH...ANY TAF SITE WITH HEAVY RAINFALL WILL DROP DOWN TO FIELD MINS
THIS AFTERNOON AND INTO THIS EVENING. HAVE SHOWN THIS IN THE TAFS.
LATER TONIGHT...WITH AREAS THAT HAVE RECEIVED RAINFALL...FOG AND LOW
CEILINGS WILL DEVELOP AND HAVE SHOWN THIS IN THE TAFS AS WELL. WINDS
WILL GENERALLY BE LIGHT EXCEPT IN AROUND THUNDERSTORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SHALLENBERGER
LONG TERM...SHALLENBERGER
AVIATION...SHALLENBERGER
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1157 PM CDT Sun Aug 10 2014
.UPDATE...
Issued at 1157 PM CDT SUN AUG 10 2014
The AVIATION section has been updated for the 06Z TAF issuance.
UPDATE Issued at 837 PM CDT SUN AUG 10 2014
Best surface based moisture and instability remains clustered
across the western edge of the WFO PAH forecast area during the
last 2-3 hours. However, there is some evidence that theta-e
convergence at the low levels is working southeast toward the
confluence of the Mississippi and Ohio Rivers in advance of a weak
surface low centered near Oregon County Missouri at 8 pm CDT.
The current convection appears to be moving from surface based to
elevated in a weak shear environment. The RAP/HRRR guidance
suggests some redevelopment during the overnight hours near the
frontal axis near the upper end of the planetary boundary layer
stretching from Southeast Missouri into southern sections of West
Kentucky. Although tempting to remove any measurable PoPs
overnight, the RAP suggests another wave rotating southeast in the
upper trough through Missouri after midnight. Surface to 850 mb
lapse rates are marginal for convection, as well as low level
(0-3km) shear. At this time, backed off wider coverage of
PoPs/Weather, but did not eliminate at all near the antecedent
frontal boundary overnight. There still seems to be some
maintenance of the multi-cellular convection this evening, so will
leave a small PoP overnight. Given the cloud cover, patchy fog, and
proximity to the old frontal boundary, raised temperatures one to two
degrees into southern sections of West Kentucky,
&&
.SHORT TERM...(Tonight through Tuesday night)
Issued at 115 PM CDT SUN AUG 10 2014
Area still convection free. However a wave moving across wcntrl MO
appears headed for the CWA. Convection with it not terribly
impressive. Accounted for it with some chance PoPs as it continues
east. Otherwise, some PVA seen in the models overnight, means
keeping chance PoPs going is warranted for showers, maybe a
rumble of thunder. Could see some fog development again tonight
given little change in surface-boundary layer conditions.
Chance PoPs will continue Monday, though will slowly shift east
with time into the afternoon and Monday night with associated weak
forcing. Inherited dry Tuesday and a consensus of the latest data
continues to support that notion for the most part. Dry, cooler
and less humid Tuesday night as high pressure continues to build in.
.LONG TERM...(Wednesday through Sunday)
Issued at 246 PM CDT SUN AUG 10 2014
High pressure over the middle Mississippi valley will keep the
region dry Wednesday into Thursday. Dry and cooler air will
remain in place with continued light north to northeast winds. As
the high moves east, winds will shift back to the south late
Thursday into Friday. Warmer air and increasing dew points can be
expected Friday and through the weekend with temperatures back to
seasonal normals over the weekend. Models are in disagreement and
overall inconsistent dealing with an upper level trof affecting
the PAH forecast area Friday and through the weekend. Models have
backed off precip chances for Friday, so removed any chances for
showers and thunderstorms. The latest ECMWF is much more
aggressive than its previous run and spreads significant precip
across our entire region Friday night into Saturday. The latest
GFS looks more like the much slower previous ECMWF run. Overall
believe chances will slowly increase through the weekend from west
to east, but due to timing uncertainties, kept pops in the chance
to slight chance categories for now.
&&
.AVIATION...
Issued at 1157 PM CDT SUN AUG 10 2014
Elevated showers and thunderstorms are likely to continue
developing over southeast Missouri for the next few hours, and then
stream eastward for much of the overnight hours. KCGI and KPAH
will likely be impacted, but it should stay south of KEVV and
KOWB. The convection may clear KCGI in time to allow some fog
development near sunrise. Elsewhere, it is hard to see anything
more than MVFR fog developing. Cannot rule out an MVFR ceiling
through midday at any terminal, but confidence is too low to
mention at this time. There is a decent signal for at least
scattered thunderstorm development late in the morning and through
much of the afternoon, mainly east of the Mississippi River.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS/DB
LONG TERM...RST
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
105 PM CDT MON AUG 11 2014
.AVIATION...
FOR THE 11/18Z TAFS...WEAK FRONTAL BOUNDARY TO CONTINUE SLOW SWRD
PROGRESS DURING THE TAF PERIOD. SCATTERED CONVECTION ALREADY SEEN
EARLY THIS AFTERNOON WITH GREATEST CONCENTRATION ACROSS THE EAST
AFFECTING THE ELD/MLU TERMINALS. FARTHER WEST...COVERAGE WILL STAY
MORE ISOLATED SO HAVE HANDLED REMAINING SITES WITH VCTS THROUGH
THIS AFTERNOON/EARLY EVENING. CONDITIONS ARE EXPECTED TO REMAIN
MOSTLY VFR WITH PERIODS OF MVFR CIGS/VSBYS POSSIBLE DURING HEAVY
DOWNPOURS. CLOUDS WILL GRADUALLY DECREASE FROM NORTH TO SOUTH
OVERNIGHT BEHIND THE FRONT WITH WINDS BECOMING MORE N/NW AND
SPEEDS LESS THAN 10 KTS OUTSIDE AREAS OF CONVECTION. /19/
&&
.PREV DISCUSSION... /ISSUED 1139 AM CDT MON AUG 11 2014/
DISCUSSION...
THE EARLY MORNING CONVECTION OVER SW AR HAS QUICKLY EXITED THE
REGION TO THE E INTO SE AR/EXTREME NE LA...WITH AN ATTENDANT
OUTFLOW BNDRY SHIFTING SE ACROSS SE UNION AND LINCOLN
PARISHES...WITH A 2ND BNDRY FARTHER TO THE SE ACROSS NE WINN/SRN
OUACHITA PARISHES. ISOLATED -SHRA HAVE DIMINISHED IN THE LAST HOUR
WITH VERY QUIET CONDITIONS IN PLACE ACROSS THE REMAINDER OF THE
REGION. THE 16Z SFC ANALYSIS INDICATED A WEAK SURFACE TROUGH
SITUATED W TO E ALONG THE I-20 CORRIDOR OF NCNTRL/NE TX/N
LA...ALTHOUGH THE SLIGHTLY DRY AIR LAGS THIS TROUGH A WAYS INTO SE
OK/NW AR. THE SHORT TERM PROGS SUGGEST THAT THIS SFC TROUGH WILL
NOT MOVE MUCH FARTHER S THIS AFTERNOON...UNLESS CONVECTIVELY
REINFORCED...GIVEN THE WEAK PRESSURE RISES TO THE N AND THE
SHALLOW NATURE OF THE FRONT. MEANWHILE...WATER VAPOR IMAGERY
DEPICTS A LONGWAVE TROUGH DIGGING SE THROUGH THE PLAINS THIS
MORNING...WITH THE UPPER TROUGH AXIS EXTENDING FROM NRN OK/SRN
MO...NE TO LAKE MI. SCT CONVECTION TO THE W JUST S OF THE RED
RIVER OF N TX THIS MORNING BEHIND THE SFC TROUGH CONTINUES TO
DIMINISH ATTM...WITH THE 06Z AND 12Z GFS NOT BULLISH AT ALL IN
CONVECTION DEVELOPING ONCE FURTHER DESTABILIZATION IS REALIZED
THIS AFTERNOON WITH ADDED HEATING. MEANWHILE...THE 12Z WRF AND
LATEST HRRR RUNS SUGGEST THAT SCT CONVECTION WILL DEVELOP AFTER 18Z
MAINLY ALONG/S OF THE I-20 CORRIDOR NEAR/S OF THE SFC
TROUGH...WHERE PW/S EXCEEDING 2.10 INCHES AND STRONG HEATING WILL
CONTRIBUTE TO STEEPER LOW LEVEL LAPSE RATES/3000+ J/KG MLCAPE.
HOWEVER...DEEP LAYER SHEAR AND FORCING SHOULD REMAIN WEAK...WITH
THE CONVECTION PRIMARILY OUTFLOW DRIVEN.
GIVEN THIS...HAVE TRIMMED BACK POPS TO CHANCE ACROSS MUCH OF E
TX/N LA...TAPERING TO SLIGHT CHANCE ACROSS EXTREME NE TX/FAR SRN
AR. HAVE DROPPED POPS FARTHER N ACROSS SE OK/NRN SECTIONS OF SW AR
GIVEN THE ABSENCE OF FRONTAL FORCING AND INTRUSION OF DEEP LEVEL DRIER
AIR. STILL CAN/T RULE OUT BRIEF HEAVY RAINFALL IN THE STRONGER
STORMS GIVEN THE HIGH PW/S AND VERY DEEP WARM LAYER INDICATED ON
THE 12Z KSHV RAOB...BUT THE LACK OF A FOCUSING MECHANISM FOR THIS
PRECLUDES MENTION IN THE FORECAST ATTM.
THE LACK OF CONVECTION/CLOUD COVER THIS MORNING HAS ALLOWED TEMPS
TO QUICKLY REACH THE UPPER 80S/LOWER 90S AS OF 16Z...THUS HAVE
BUMPED UP MAX TEMPS AREAWIDE A FEW DEGREES. HEAT INDICES MAY
BRIEFLY APPROACH HEAT ADVISORY CRITERIA THIS AFTERNOON OVER
PORTIONS OF E TX/N LA WHERE MOISTURE POOLING IS EVIDENT NEAR/S OF
THE SFC TROUGH...BUT GIVEN THE EXPECTATION OF SCT CONVECTION
FIRING THIS AFTERNOON...WILL FOREGO THE ISSUANCE OF A HEAT
ADVISORY ATTM.
THE CONVECTION SHOULD QUICKLY DIMINISH THIS EVENING AS THE BNDRY
LYR STABILIZES...AND DRIER AIR ALOFT BEGIN TO MIX S INTO THE
REGION WITH THE PASSAGE OF THE LONGWAVE TROUGH...WHICH SHOULD
EVENTUALLY REINFORCE THE SFC TROUGH S THROUGH THE AREA.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 95 75 90 69 91 / 40 20 0 10 10
MLU 93 73 90 68 89 / 50 20 10 10 10
DEQ 92 67 87 61 88 / 10 10 0 10 10
TXK 94 72 88 64 88 / 20 10 0 10 10
ELD 91 71 89 64 88 / 20 10 0 10 10
TYR 94 73 91 67 91 / 40 10 0 10 10
GGG 94 73 90 65 90 / 40 20 0 10 10
LFK 97 76 93 69 94 / 50 30 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
19
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1139 AM CDT MON AUG 11 2014
.DISCUSSION...
THE EARLY MORNING CONVECTION OVER SW AR HAS QUICKLY EXITED THE
REGION TO THE E INTO SE AR/EXTREME NE LA...WITH AN ATTENDANT
OUTFLOW BNDRY SHIFTING SE ACROSS SE UNION AND LINCOLN
PARISHES...WITH A 2ND BNDRY FARTHER TO THE SE ACROSS NE WINN/SRN
OUACHITA PARISHES. ISOLATED -SHRA HAVE DIMINISHED IN THE LAST HOUR
WITH VERY QUIET CONDITIONS IN PLACE ACROSS THE REMAINDER OF THE
REGION. THE 16Z SFC ANALYSIS INDICATED A WEAK SURFACE TROUGH
SITUATED W TO E ALONG THE I-20 CORRIDOR OF NCNTRL/NE TX/N
LA...ALTHOUGH THE SLIGHTLY DRY AIR LAGS THIS TROUGH A WAYS INTO SE
OK/NW AR. THE SHORT TERM PROGS SUGGEST THAT THIS SFC TROUGH WILL
NOT MOVE MUCH FARTHER S THIS AFTERNOON...UNLESS CONVECTIVELY
REINFORCED...GIVEN THE WEAK PRESSURE RISES TO THE N AND THE
SHALLOW NATURE OF THE FRONT. MEANWHILE...WATER VAPOR IMAGERY
DEPICTS A LONGWAVE TROUGH DIGGING SE THROUGH THE PLAINS THIS
MORNING...WITH THE UPPER TROUGH AXIS EXTENDING FROM NRN OK/SRN
MO...NE TO LAKE MI. SCT CONVECTION TO THE W JUST S OF THE RED
RIVER OF N TX THIS MORNING BEHIND THE SFC TROUGH CONTINUES TO
DIMINISH ATTM...WITH THE 06Z AND 12Z GFS NOT BULLISH AT ALL IN
CONVECTION DEVELOPING ONCE FURTHER DESTABILIZATION IS REALIZED
THIS AFTERNOON WITH ADDED HEATING. MEANWHILE...THE 12Z WRF AND
LATEST HRRR RUNS SUGGEST THAT SCT CONVECTION WILL DEVELOP AFTER 18Z
MAINLY ALONG/S OF THE I-20 CORRIDOR NEAR/S OF THE SFC
TROUGH...WHERE PW/S EXCEEDING 2.10 INCHES AND STRONG HEATING WILL
CONTRIBUTE TO STEEPER LOW LEVEL LAPSE RATES/3000+ J/KG MLCAPE.
HOWEVER...DEEP LAYER SHEAR AND FORCING SHOULD REMAIN WEAK...WITH
THE CONVECTION PRIMARILY OUTFLOW DRIVEN.
GIVEN THIS...HAVE TRIMMED BACK POPS TO CHANCE ACROSS MUCH OF E
TX/N LA...TAPERING TO SLIGHT CHANCE ACROSS EXTREME NE TX/FAR SRN
AR. HAVE DROPPED POPS FARTHER N ACROSS SE OK/NRN SECTIONS OF SW AR
GIVEN THE ABSENCE OF FRONTAL FORCING AND INTRUSION OF DEEP LEVEL DRIER
AIR. STILL CAN/T RULE OUT BRIEF HEAVY RAINFALL IN THE STRONGER
STORMS GIVEN THE HIGH PW/S AND VERY DEEP WARM LAYER INDICATED ON
THE 12Z KSHV RAOB...BUT THE LACK OF A FOCUSING MECHANISM FOR THIS
PRECLUDES MENTION IN THE FORECAST ATTM.
THE LACK OF CONVECTION/CLOUD COVER THIS MORNING HAS ALLOWED TEMPS
TO QUICKLY REACHING THE UPPER 80S/LOWER 90S AS OF 16Z...THUS HAVE
BUMPED UP MAX TEMPS AREAWIDE A FEW DEGREES. HEAT INDICES MAY
BRIEFLY APPROACH HEAT ADVISORY CRITERIA THIS AFTERNOON OVER
PORTIONS OF E TX/N LA WHERE MOISTURE POOLING IS EVIDENT NEAR/S OF
THE SFC TROUGH...BUT GIVEN THE EXPECTATION OF SCT CONVECTION
FIRING THIS AFTERNOON...WILL FOREGO THE ISSUANCE OF A HEAT
ADVISORY ATTM.
THE CONVECTION SHOULD QUICKLY DIMINISH THIS EVENING AS THE BNDRY
LYR STABILIZES...AND DRIER AIR ALOFT BEGIN TO MIX S INTO THE
REGION WITH THE PASSAGE OF THE LONGWAVE TROUGH...WHICH SHOULD
EVENTUALLY REINFORCE THE SFC TROUGH S THROUGH THE AREA.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 95 75 90 69 91 / 40 20 0 10 10
MLU 93 73 90 68 89 / 50 20 10 10 10
DEQ 92 67 87 61 88 / 10 10 0 10 10
TXK 94 72 88 64 88 / 20 10 0 10 10
ELD 91 71 89 64 88 / 20 10 0 10 10
TYR 94 73 91 67 91 / 40 10 0 10 10
GGG 94 73 90 65 90 / 40 20 0 10 10
LFK 97 76 93 69 94 / 50 30 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
730 PM EDT TUE AUG 12 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT TUE AUG 12 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW JUST
EAST OF THE SAULT RESULTING IN NNW FLOW FROM NW ONTARIO THROUGH THE
WRN GREAT LAKES. THE BACK EDGE OF THE CLOUDS ASSOCIATED WITH THE LOW
HAD MOVED TO NEAR SAW-IMT LEAVING CLEAR SKIES OVER THE WEST AND
THICK CLOUDS WITH A FEW SPRINKLES OVER THE ERN CWA. AN UPSTREAM
CLIPPER SHORTWAVE TROUGH AND COLD FRONT THAT SUPPORTED A FEW LIGHT
SHOWERS OR SPRINKLES WAS MOVING THROUGH NW ONTARIO.
TONIGHT...EXPECT THAT SOME LIGHT SHOWERS OR SPRINKLES ASSOCIATED
WITH THE NW ONTARIO SHRTWV MAY MOVE INTO WRN LAKE SUPERIOR AND
POSSIBLY WRN UPPER MI. HOWEVER...SINCE FORCING WITH THE SHRTWV IS
WEAK AND LITTLE MOISTURE/INSTABILITY IS AVAILABLE DURING THE
OVERNIGHT...NO PCPN MENTION WAS ADDED TO THE FCST.
WED...BEHIND THE COLD FRONT...NNW WINDS WILL AGAIN INCREASE WHICH
COULD SUPPORT AN INCREASE IN UPSLOPE CLOUDS OVER N CNTRL UPPER MI.
TEMPS WILL REMAIN BELOW NORMAL WITH HIGHS FROM THE MID 60S NORTH TO
THE LOWER 70S SOUTH. SWIM RISK WILL AGAIN BE HIGH AS 3 TO 5 FOOT
WAVES ARE EXPECTED INTO MARQUETTE AND ALGER COUNTIES BY AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 PM EDT TUE AUG 12 2014
MAIN FCST CONCERNS IN THE MEDIUM/LONGER RANGE WL FOCUS ON EXPECTED
BLO NORMAL TEMPS FOR WED THRU THU...WHEN DRY CNDN HI PRES IS FCST TO
DOMINATE UNDER A CONFLUENT NNW FLOW ALF. FOCUS FOR FRI/SAT WL SHIFT
TO PCPN CHCS ASSOCIATED WITH THE INTERACTION BTWN RETURNING MSTR IN
THE LLVL SW FLOW ARND THE DEPARTING HI TO THE SE AND SHRTWVS
TRACKING THRU THE GREAT LKS WITHIN THE NW FLOW FARTHER ALF. ALTHOUGH
ABV NORMAL TEMPS MAY RETURN FOR FRI INTO SAT...NO SUMMER-LIKE WARMTH
IS EXPECTED DURING THE NEXT WEEK.
WED NGT/THU...HI PRES AND DRY AIRMASS WITH PWAT BTWN 0.25-0.50 INCH
/AS LITTLE AS ABOUT 25 PCT OF NORMAL/ WL PASS OVER UPR MI UNDER NNW
FLOW ALF TO THE W OF SLOW MOVING CLOSED LO NEAR THE ONTARIO/QUEBEC
BORDER. UNDER MOCLR SKIES...EXPECT THE LOWEST MIN TEMPS ON WED NGT
OVER THE INTERIOR W...WHERE WINDS WL BE LIGHTEST FOR A LONGER TIME
AND WHERE THE RDG AXIS IS FCST TO BE AT 12Z THU. NOT OUT OF THE
QUESTION THERE COULD BE SOME 30S AT THE COLDER LOCATIONS IN THIS
AREA. WITH H85 TEMPS FCST TO PEAK BTWN 8C OVER THE E AND 12C OVER
THE W AT 00Z FRI...EXPECT HI TEMPS TO REACH THE 70S OVER THE
INTERIOR W/SCENTRAL BUT HOLD IN THE 60S OVER MUCH OF THE E WITH A
STEADY NNW SFC-H925 FLOW OFF LK SUP.
THU NGT...SFC HI PRES IS FCST TO SINK OVER INDIANA BY 12Z FRI...
WITH SFC RDG AXIS EXTENDING N THRU ERN UPR MI. THE LOWEST TEMPS WL
BE OVER THE INTERIOR E...WHERE PWAT UNDER 0.5 INCH/MOCLR SKIES/
LIGHTER WINDS UNDER THE RDG AXIS WL LINGER THRU THE NGT. SOME CLDS
ASSOCIATED WITH PWAT RISING AOA 1 INCH AT IWD BY 12Z FRI IN SW
RETURN FLOW ARND THE SFC HI WL LIMIT THE DIURNAL TEMP FALL IN THAT
AREA.
FRI THRU SAT...UPR MI IS FCST TO REMAIN UNDER NW FLOW ALF BTWN DEEP
UPR TROF OVER QUEBEC AND RDG EXTENDING THRU THE PLAINS. THE
INTERACTION BTWN SHRTWVS DIGGING SEWD THRU THIS UPR FLOW AND MORE
MSTR ADVECTED INTO THE AREA IN LLVL WSW FLOW TO THE NW OF SFC HI
FCST TO SINK INTO THE SRN MID ATLANTIC STATES WL BE THE MAIN FCST
CONCERN DURING THIS PERIOD. A GOOD NUMBER OF THE MEDIUM RANGE MODELS
GENERATE PCPN AS EARLY AS FRI...WHEN THE HIER PWAT ARND 1.5 INCHES
IS FCST TO RETURN. CONSIDERING THE RATHER DRAMATIC INCRS IN PWAT/
SOME ISENTROPIC ASCENT...ADDED CHC POPS FOR THE FRI FCST DESPITE AN
ABSENCE OF SGNFT DEEP LYR QVECTOR CNVGC WELL SE OF STRONGER SHRTWV
SLIDING THRU NW ONTARIO. A BETTER CHC OF SHOWERS/A FEW TS WL ARRIVE
ON FRI NGT AND SAT...WHEN MODEL CONSENSUS IS TRENDING TOWARD THE
PASSAGE OF THE DIGGING ONTARIO SHRTWV/ATTENDANT SFC COLD FNT AND AN
AREA OF SHARPER DEEP LYR QVECTOR CNVGC. ALTHOUGH THE GREATER CLD
COVER WL TEND TO LIMIT THE DIURNAL DIURNAL VARIATION DURING THIS
TIME...EXPECT TEMPS TO RISE ABV NORMAL DURING THIS PERIOD AS THE WSW
FLOW BRINGS A RETURN OF H85 TEMPS AS HI AS 16-17C BY SAT.
SUN THRU TUE...MOST OF THE LONGER RANGE MODELS INDICATE SFC HI PRES
WL BLD INTO THE UPR LKS ON SUN FOLLOWING SHRTWV/COLD FROPA PASSAGE
BY LATE SAT...SO CONSENSUS FCST WL SHOW A DRYING TREND AND A RETURN
OF A BIT COOLER AIR. PCPN CHCS WL RETURN EARLY NEXT WEEK AS THE UPR
FLOW IS FCST TO BECOME MORE ZONAL AND ALLOW THE PASSAGE OF ANOTHER
SHRTWV.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 729 PM EDT TUE AUG 12 2014
HIGH PRESSURE AND DRIER AIR MOVING INTO THE WESTERN U.P. WILL BRING
VFR CONDITIONS TO ALL SITES THROUGH THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 PM EDT TUE AUG 12 2014
NORTH WINDS GUSTING TO MORE THAN 25 KTS ACROSS THE EASTERN PART OF
THE LAKE WILL DIMINISH THIS EVENING AS THE PRES GRADIENT WEAKENS. A
REINFORCING COLD FRONT WILL PUSH ACROSS THE LAKE ON WEDNESDAY
ALLOWING NORTHWESTERLY WIND GUSTS OF UP TO 25 KTS WEDNESDAY
AFTERNOON. WINDS SHOULD DIMINISH BY LATE WEDNESDAY AND THEN REMAIN
BELOW 15 KTS INTO THE UPCOMING WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ005-
006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
702 PM EDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 410 PM EDT MON AUG 11 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
THE ROCKIES AND A TROUGH FROM HUDSON BAY INTO THE UPPER MS VALLEY.
AT THE SFC...A FRONT EXTENDED FROM SE LAKE SUPERIOR INTO NE WI. A
DEEPENING TROUGH WITH AN 85 KNOT 250 MB JET MOVING THROUGH WRN
WI...AND 800-600 MB FGEN SUPPORTED A LARGE ARA OF PCPN THROUGH WRN
UPPER MI. ANOTHER AREA OF SHOWERS INTO SE AND ERN UPPER MI WAS
ASSOCIATED WITH A WEAK SHRTWV TROUGH INTO NRN LAKE MI.
TONIGHT...EXPECT SHRA COVERAGE TO GRADUALLY INCREASE OVER CNTRL
UPPER MI AS THE WEAKENING FGEN FORCING SHIFTS TO THE EAST.
WITH MINIMAL/SKINNY MUCAPE AOB 400 J/KG AND NO TSRA OBSERVED TODAY...ONLY
SLIGHT CHANCE TSRA WAS RETAINED THROUGH THIS EVENING. AS THE TROUGH
CONTINUED TO DEEPEN AND LOW PRES OVER WRN LOWER MI LIFTS TO LAKE
HURON...NRLY FLOW WILL STRENGTHEN ACROSS UPPER MI. THE COMBINATION OF
THE MID LEVEL FORCING AND INCREASED ONSHORE/UPSLOPE FLOW WILL ALSO
BRING AN INCREASE IN LIGHT RAIN OR DRIZZLE INTO N CNTRL UPPER MI
OVERNIGHT.
TUE...AREAS OF LIGHT RAIN OR DRIZZLE MAY CONTINUE IN THE MORNING
THROUGH N CNTRL UPPER AND E UPPER MI AND GRADUALLY DIMINISH INTO THE
AFTERNOON AS THE DEEP MOISTURE FINALLY SLIDES TO THE EAST...PER NAM
850-700 MB RH FCST. OTHERWISE...COOLER CONDITIONS ARE EXPECTED WITH
BRISK NRLY WINDS KEEPING TEMPS IN THE 60S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 358 PM EDT MON AUG 11 2014
A 500MB LOW PRESSURE TROUGH OVER THE GREAT LAKES TUESDAY EVENING
WILL DEVELOP INTO A CUT OFF LOW OVER THE LOWER LAKES THURSDAY
MORNING...THEN LIFT INTO QUEBEC BY FRIDAY EVENING. AT THE
SURFACE...LOW PRESSURE OVER LAKE HURON WILL LIFT NORTHEASTWARD INTO
QUEBEC THROUGH WEDNESDAY EVENING. AS A RESULT...ONLY HAVE LINGERING
POPS FAR EAST CLOSEST TO THE LOW THROUGH WEDNESDAY EVENING. SOME OF
THE MODELS GENERATE PRECIPITATION WITH A SHORTWAVE THAT SWINGS
AROUND THE LOW ON WEDNESDAY AFTERNOON AND EVENING...BUT THINK THIS
MAY BE OVERDOING IT AS DRY AIR WILL START TO CREEP INTO THE AREA.
KEPT WEATHER ON WEDNESDAY DRY FOR NOW...BUT BUMPED UP SKY COVER WEST
AND ALONG THE WI BORDER AS WELL. WITH A STRONGER PRESSURE GRADIENT
ACROSS THE EASTERN PORTION OF LK SUPERIOR...HAVE ONSHORE/NORTHWEST
WINDS GUSTING 10 TO 20 MPH AND WAVE HEIGHTS AROUND 3 TO 4 FEET IN
ALGER COUNTY AND MAINLY FAR EASTERN MARQUETTE COUNTY NEAR LAKE
SUPERIOR. EXPECT A MODERATE SWIM RISK FOR DANGEROUS CURRENTS AND
WAVES IN THESE AREAS.
SURFACE HIGH PRESSURE MOVES FROM THE CANADIAN PRAIRIES/NORTHERN
PLAINS INTO THE GREAT LAKES BY THURSDAY AFTERNOON...SO HAVE KEPT A
SEASONABLY COOL BUT DRY FORECAST THROUGH THEN. AS THE CLOSED LOW
ALOFT MOVES FROM ONTARIO INTO QUEBEC ON FRIDAY UPPER LEVEL FLOW
BECOMES MORE ZONAL OVER UPPER MICHIGAN. THE SURFACE HIGH DRIFTS
SOUTHEASTWARD INTO THE OHIO VALLEY...MAKING WAY FOR A WEAK SURFACE
TROUGH TO DROP ACROSS NORTHERN LAKE SUPERIOR. WITH WEAK FORCING
ACROSS THE AREA...WOULDNT BE SURPRISED TO SEE ISOLATED
SHOWERS/TSTORMS ACROSS THE WESTERN AND NORTH CENTRAL PARTS OF THE
CWA. HAVE ADDED THEM IN ACCORDINGLY. THIS WEAK SURFACE TROUGH WILL
DRIVE ACROSS THE GREAT LAKES FRIDAY NIGHT INTO SATURDAY...SO HAVE
KEPT SLIGHT CHANCE POPS FOR THE WHOLE AREA.
A MORE POTENT 500MB SHORTWAVE ARRIVES SUNDAY NIGHT INTO
MONDAY...WITH THE ASSOCIATED SURFACE LOW PRESSURE CENTERED OVER
NORTHERN MN/NORTHWESTERN ONTARIO. ANOTHER SURFACE LOW DEVELOPS OVER
WI/IOWA AROUND THE SAME TIME AND MERGES WITH THE OTHER LOW OVER LAKE
SUPERIOR BY MONDAY EVENING. MODELS ARE IN SOMEWHAT OF A DISAGREEMENT
OVER THIS...AS USUAL WITH MERGING SYSTEMS/SHORTWAVES. HAVE KEPT
CONSENSUS CHANCE/SLIGHT CHANCE POPS FOR NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 702 PM EDT MON AUG 11 2014
MVFR CONDITIONS WILL CONTINUE AT IWD THROUGH TONIGHT BEFORE DRIER
AIR MOVES IN FOR TUE MORNING AND LEADS TO VFR CONDITIONS THROUGH THE
REST OF THE PERIOD.
RAIN ALONG WITH MOIST NORTHERLY FLOW WILL KEEP IFR CIGS GOING AT CMX
TONIGHT AND SHOULD LOWER CIGS AT SAW TO IFR/LIFR TONIGHT. KCMX
SHOULD SEE SOME IMPROVEMENT FROM IFR CONDITIONS LATER TONIGHT AS
RAIN MOVES OUT AND SHOULD BE VFR WITH DRIER AIR BY TUE AFTERNOON.
CYCLONIC UPSLOPE FLOW INTO THE NORTH CENTRAL U.P. WILL KEEP LOW CIGS
AT KSAW INTO TUESDAY AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EDT MON AUG 11 2014
A COLD FRONT WILL MOVE ACROSS THE LAKE TODAY. BEHIND THE COLD
FRONT...NORTH WINDS WILL INCREASE MON AND GUST TO MORE THAN 20 KT
MON NIGHT INTO TUE...PRODUCING WAVES UP TO 7 FT OVER THE CENTRAL AND
EASTERN LAKE. HIGH PRESSURE BUILDING INTO THE AREA BY WED NIGHT WILL
ALLOW WINDS TO ONCE AGAIN SUBSIDE TO BELOW 15 KT BY MID WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MCD
AVIATION...07
MARINE...MZ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
412 PM EDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 410 PM EDT MON AUG 11 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
THE ROCKIES AND A TROUGH FROM HUDSON BAY INTO THE UPPER MS VALLEY.
AT THE SFC...A FRONT EXTENDED FROM SE LAKE SUPERIOR INTO NE WI. A
DEEPENING TROUGH WITH AN 85 KNOT 250 MB JET MOVING THROUGH WRN
WI...AND 800-600 MB FGEN SUPPORTED A LARGE ARA OF PCPN THROUGH WRN
UPPER MI. ANOTHER AREA OF SHOWERS INTO SE AND ERN UPPER MI WAS
ASSOCIATED WITH A WEAK SHRTWV TROUGH INTO NRN LAKE MI.
TONIGHT...EXPECT SHRA COVERAGE TO GRADUALLY INCREASE OVER CNTRL
UPPER MI AS THE WEAKENING FGEN FORCING SHIFTS TO THE EAST.
WITH MINIMAL/SKINNY MUCAPE AOB 400 J/KG AND NO TSRA OBSERVED TODAY...ONLY
SLIGHT CHANCE TSRA WAS RETAINED THROUGH THIS EVENING. AS THE TROUGH
CONTINUED TO DEEPEN AND LOW PRES OVER WRN LOWER MI LIFTS TO LAKE
HURON...NRLY FLOW WILL STRENGTHEN ACROSS UPPER MI. THE COMBINATION OF
THE MID LEVEL FORCING AND INCREASED ONSHORE/UPSLOPE FLOW WILL ALSO
BRING AN INCREASE IN LIGHT RAIN OR DRIZZLE INTO N CNTRL UPPER MI
OVERNIGHT.
TUE...AREAS OF LIGHT RAIN OR DRIZZLE MAY CONTINUE IN THE MORNING
THROUGH N CNTRL UPPER AND E UPPER MI AND GRADUALLY DIMINISH INTO THE
AFTERNOON AS THE DEEP MOISTURE FINALLY SLIDES TO THE EAST...PER NAM
850-700 MB RH FCST. OTHERWISE...COOLER CONDITIONS ARE EXPECTED WITH
BRISK NRLY WINDS KEEPING TEMPS IN THE 60S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 358 PM EDT MON AUG 11 2014
A 500MB LOW PRESSURE TROUGH OVER THE GREAT LAKES TUESDAY EVENING
WILL DEVELOP INTO A CUT OFF LOW OVER THE LOWER LAKES THURSDAY
MORNING...THEN LIFT INTO QUEBEC BY FRIDAY EVENING. AT THE
SURFACE...LOW PRESSURE OVER LAKE HURON WILL LIFT NORTHEASTWARD INTO
QUEBEC THROUGH WEDNESDAY EVENING. AS A RESULT...ONLY HAVE LINGERING
POPS FAR EAST CLOSEST TO THE LOW THROUGH WEDNESDAY EVENING. SOME OF
THE MODELS GENERATE PRECIPITATION WITH A SHORTWAVE THAT SWINGS
AROUND THE LOW ON WEDNESDAY AFTERNOON AND EVENING...BUT THINK THIS
MAY BE OVERDOING IT AS DRY AIR WILL START TO CREEP INTO THE AREA.
KEPT WEATHER ON WEDNESDAY DRY FOR NOW...BUT BUMPED UP SKY COVER WEST
AND ALONG THE WI BORDER AS WELL. WITH A STRONGER PRESSURE GRADIENT
ACROSS THE EASTERN PORTION OF LK SUPERIOR...HAVE ONSHORE/NORTHWEST
WINDS GUSTING 10 TO 20 MPH AND WAVE HEIGHTS AROUND 3 TO 4 FEET IN
ALGER COUNTY AND MAINLY FAR EASTERN MARQUETTE COUNTY NEAR LAKE
SUPERIOR. EXPECT A MODERATE SWIM RISK FOR DANGEROUS CURRENTS AND
WAVES IN THESE AREAS.
SURFACE HIGH PRESSURE MOVES FROM THE CANADIAN PRAIRIES/NORTHERN
PLAINS INTO THE GREAT LAKES BY THURSDAY AFTERNOON...SO HAVE KEPT A
SEASONABLY COOL BUT DRY FORECAST THROUGH THEN. AS THE CLOSED LOW
ALOFT MOVES FROM ONTARIO INTO QUEBEC ON FRIDAY UPPER LEVEL FLOW
BECOMES MORE ZONAL OVER UPPER MICHIGAN. THE SURFACE HIGH DRIFTS
SOUTHEASTWARD INTO THE OHIO VALLEY...MAKING WAY FOR A WEAK SURFACE
TROUGH TO DROP ACROSS NORTHERN LAKE SUPERIOR. WITH WEAK FORCING
ACROSS THE AREA...WOULDNT BE SURPRISED TO SEE ISOLATED
SHOWERS/TSTORMS ACROSS THE WESTERN AND NORTH CENTRAL PARTS OF THE
CWA. HAVE ADDED THEM IN ACCORDINGLY. THIS WEAK SURFACE TROUGH WILL
DRIVE ACROSS THE GREAT LAKES FRIDAY NIGHT INTO SATURDAY...SO HAVE
KEPT SLIGHT CHANCE POPS FOR THE WHOLE AREA.
A MORE POTENT 500MB SHORTWAVE ARRIVES SUNDAY NIGHT INTO
MONDAY...WITH THE ASSOCIATED SURFACE LOW PRESSURE CENTERED OVER
NORTHERN MN/NORTHWESTERN ONTARIO. ANOTHER SURFACE LOW DEVELOPS OVER
WI/IOWA AROUND THE SAME TIME AND MERGES WITH THE OTHER LOW OVER LAKE
SUPERIOR BY MONDAY EVENING. MODELS ARE IN SOMEWHAT OF A DISAGREEMENT
OVER THIS...AS USUAL WITH MERGING SYSTEMS/SHORTWAVES. HAVE KEPT
CONSENSUS CHANCE/SLIGHT CHANCE POPS FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 146 PM EDT MON AUG 11 2014
VFR CONDITIONS WITH SOME OCCASIONAL MVFR CIGS ARE POSSIBLE AT IWD
BEHIND THE MAIN AREA OF RAIN. HOWEVER CONFIDENCE IS LOW UNTIL LATER
TONIGHT WHEN MORE SUBSTANTIAL DRYING MOVES IN AND KEEPS CIGS IN THE
VFR RANGE.
RAIN ALONG WITH MOIST NORTHERLY FLOW SPREADING FROM WEST TO EAST
THROUGH WEST/CENTRAL UPPER MICHIGAN WILL KEEP IFR CIGS GOING AT CMX INTO
THIS EVENING AND SHOULD LOWER CIGS AT SAW FROM MVFR LATE THIS
AFTERNOON TO IFR TONIGHT. KCMX SHOULD SEE SOME IMPROVEMENT FROM IFR
CONDITIONS OVERNIGHT TONIGHT. CYCLONIC UPSLOPE FLOW INTO THE NORTH
CENTRAL U.P. WILL KEEP LOW CIGS AT KSAW INTO TUESDAY MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EDT MON AUG 11 2014
A COLD FRONT WILL MOVE ACROSS THE LAKE TODAY. BEHIND THE COLD
FRONT...NORTH WINDS WILL INCREASE MON AND GUST TO MORE THAN 20 KT
MON NIGHT INTO TUE...PRODUCING WAVES UP TO 7 FT OVER THE CENTRAL AND
EASTERN LAKE. HIGH PRESSURE BUILDING INTO THE AREA BY WED NIGHT WILL
ALLOW WINDS TO ONCE AGAIN SUBSIDE TO BELOW 15 KT BY MID WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MCD
AVIATION...JLB
MARINE...MZ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
312 AM EDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 404 PM EDT SUN AUG 10 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL FROM THE
CNTRL/SRN ROCKIES TO THE PAC NW AND A TROUGH FROM WEST OF HUDSON BAY
TOWARD THE UPPER MS VALLEY. A WEAK SHRTWV OVER CNTRL MN AHEAD OF A
FRONT FROM NW ONTARIO INTO WRN MN SUPPORTED SCT/NMRS SHRA/TSRA FROM
N CNTRL MN INTO NW IA. OTHERWISE...JUST DIURNAL CU PREVAILED ACROSS
UPPER MI AS WEAK SRLY FLOW GRADUALLY INCREASED.
TONIGHT...EXPECT THE UPSTREAM MID LEVEL TROUGH TO DIG SOUTHEASTWARD
AS A 100 KNOT 250 MB JET STREAK DIVES TOWARD THE NRN PLAINS. AS
MOISTURE INCREASES AHEAD OF THE FRONT...EXPECT THE SHRA AND A FEW
TSRA TO ADVANCE STEADILY TO THE EAST WITH CHANCE POPS ACROSS THE WRN
THIRD INCREASING AFT 06Z.
MON...AS THE TROUGH CONTINUES TO DEEPEN...MID LEVEL QVECTOR CONV AND
FGEN COMBINED WITH INCREASING MOISTURE(PWAT TO 1.5 INCHES OR 150 PCT
OR NORMAL) WILL SUPPORT LIKELY POPS MOVING ACROSS THE CWA. MODELS
MUCAPE VALUES OF ONLY 100-400 J/KG WITH SKINNY CAPE PROFILES
SUGGESTS MAINLY ISOLD TSRA WILL BE POSSIBLE. AS NORTH WINDS INCREASE
BEHIND THE FRONT...TEMPS SHOULD REMAIN STEADY OR DROP OFF DURING THE
AFTERNOON...ESPECIALLY NEAR LAKE SUPERIOR.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 311 AM EDT MON AUG 11 2014
AT 12Z TUESDAY EXPECT THE SFC LOW OVER LAKE HURON...AND THE
TRIALLING 500MB TROUGH SET UP FROM UPPER MI THROUGH LOWER MI AND
LAKE HURON. UPPER MI WILL BE STUCK BETWEEN THE SFC LOW SHIFTING UP
THROUGH THE CYSB AREA BY LATE AFTERNOON...WHILE A LARGE AREA OF HIGH
PRESSURE AVERAGING 30.0 INCHES IS SET UP FROM N MANITOBA THROUGH
ARKANSAS. WITH THE INCREASED PRESSURE GRADIENT...EXPECT N-NNW WINDS
OF 10-20KTS WITH GUSTS 15-25KTS OVER THE E HALF OF UPPER MI.
SOUNDINGS INDICATE STEADY 25-30KT WINDS JUST ABOVE THE SFC THROUGH
800MB. GIVEN THE BREEZY CONDITIONS...THERE IS A POTENTIAL FOR A HIGH
SWIM RISK FOR MARQUETTE AND ESPECIALLY ALGER COUNTY.
LIGHT RAIN SHOWERS WILL LIKELY LINGER OVER N CENTRAL AND E
UPPER MI THROUGH LATE MORNING...IF NOT LONGER FAR E. RAIN MAY TAKE
THE FORM OF DRIZZLE THANKS TO THE FAVORABLE UPSLOPE CONDITIONS AND
EXPECTED LOWER CLOUDS. 850MB TEMPS AT 12Z TUESDAY WILL BE 7-10C
/COOLEST W/. LOOK FOR THE COOLEST AIR TO SHIFT OVER E UPPER MI
THROUGH THE DAY...MODERATING SLIGHTLY.
A SECONDARY SHORTWAVE DROPPING SE ACROSS UPPER MI COULD PRODUCE
ADDITIONAL CLOUDS AS WELL AS LIGHT SHOWERS/SPRINKLES OVER W AND
CENTRAL UPPER MI TUESDAY NIGHT INTO WEDNESDAY MORNING. WILL LEAVE
THE PERIOD DRY FOR NOW. WITH 850MB TEMPS STILL HOVERING AROUND 10C
ON N-NNW WINDS ON WEDNESDAY...HIGHS SHOULD TOP OUT IN THE UPPER 60S
TO MID 70S. THIS WILL BE APPROX 5F BELOW THE NORMAL VALUE FOR THIS
TIME OF THE YEAR.
THE INCREASING INFLUENCE OF THE SURFACE HIGH WILL BRING GRADUALLY
DIMINISHING WINDS AND MOSTLY CLEAR SKIES FOR WEDNESDAY AFTERNOON
THROUGH FRIDAY NIGHT. EXPECT MOST OF THE UPPER LEVEL DISTURBANCES TO
STAY TO THE E OF THE CWA THROUGH THE END OF THE WORK WEEK...WITH
ANOTHER STRETCH OF DRY WEATHER TUESDAY NIGHT THROUGH AT LEAST
SATURDAY.
LOOK FOR THE 500MB TROUGH TO CENTER ITSELF OVER AND S OF JAMES BAY
TUESDAY NIGHT THROUGH WEDNESDAY...BEFORE SLOWLY SHIFTING TO S QUEBEC
WEDNESDAY NIGHT THROUGH FRIDAY. AS A RESULT...TO NOT EXPECT ANY
SIGNIFICANT WARM UP ACROSS UPPER MI...AS NW FLOW LINGERS ALOFT
THROUGH AT LEAST THE END OF THE WORK WEEK. THE 500MB RIDGE DOES MAKE
ANOTHER APPEARANCE BY THE WEEKEND. DRY WEATHER SHOULD BE THE RULE
FOR SATURDAY. HOWEVER FOR SATURDAY NIGHT AND INTO SUNDAY...LOOK FOR
INCREASING CHANCES FOR PRECIP AS THE SURFACE RIDGE DEPARTS AND AN
UPPER LEVEL DISTURBANCE MOVES TOWARDS THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY EVENING)
ISSUED AT 130 AM EDT MON AUG 11 2014
AREAS OF RAIN AND POSSIBLY A THUNDERSTORM WILL LOWER CONDITIONS INTO
THE MVFR RANGE BY MON MORNING AT CMX AND IWD. LOWER CLOUDS BEHIND
THE FRONT SHOULD DROP CONDITIONS INTO THE IFR RANGE AT CMX/IWD MON
MORNING AND IN THE AFTERNOON AT SAW. SLOW IMPROVEMENT TO MVFR
CONDITIONS AS RAIN MOVES OUT AT CMX AND IWD MON EVENING BUT
CONTINUES TO LINGER AT SAW WHERE CONDITIONS WILL REMAIN IFR
INTO MON EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 404 PM EDT SUN AUG 10 2014
A COLD FRONT WILL MOVE ACROSS THE LAKE TONIGHT INTO MONDAY. BEHIND
THE COLD FRONT...NORTH WINDS WILL INCREASE MON AND GUST TO MORE THAN
20 KT MON NIGHT INTO TUE...PRODUCING WAVES UP TO 7 FT. HIGH PRESSURE
BUILDING INTO THE AREA BY WED NIGHT WILL ALLOW WINDS TO ONCE AGAIN
SUBSIDE TO BELOW 15 KT BY LATE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 AM EDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 404 PM EDT SUN AUG 10 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL FROM THE
CNTRL/SRN ROCKIES TO THE PAC NW AND A TROUGH FROM WEST OF HUDSON BAY
TOWARD THE UPPER MS VALLEY. A WEAK SHRTWV OVER CNTRL MN AHEAD OF A
FRONT FROM NW ONTARIO INTO WRN MN SUPPORTED SCT/NMRS SHRA/TSRA FROM
N CNTRL MN INTO NW IA. OTHERWISE...JUST DIURNAL CU PREVAILED ACROSS
UPPER MI AS WEAK SRLY FLOW GRADUALLY INCREASED.
TONIGHT...EXPECT THE UPSTREAM MID LEVEL TROUGH TO DIG SOUTHEASTWARD
AS A 100 KNOT 250 MB JET STREAK DIVES TOWARD THE NRN PLAINS. AS
MOISTURE INCREASES AHEAD OF THE FRONT...EXPECT THE SHRA AND A FEW
TSRA TO ADVANCE STEADILY TO THE EAST WITH CHANCE POPS ACROSS THE WRN
THIRD INCREASING AFT 06Z.
MON...AS THE TROUGH CONTINUES TO DEEPEN...MID LEVEL QVECTOR CONV AND
FGEN COMBINED WITH INCREASING MOISTURE(PWAT TO 1.5 INCHES OR 150 PCT
OR NORMAL) WILL SUPPORT LIKELY POPS MOVING ACROSS THE CWA. MODELS
MUCAPE VALUES OF ONLY 100-400 J/KG WITH SKINNY CAPE PROFILES
SUGGESTS MAINLY ISOLD TSRA WILL BE POSSIBLE. AS NORTH WINDS INCREASE
BEHIND THE FRONT...TEMPS SHOULD REMAIN STEADY OR DROP OFF DURING THE
AFTERNOON...ESPECIALLY NEAR LAKE SUPERIOR.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 257 PM EDT SUN AUG 10 2014
AN UPPER LEVEL TROUGH WILL BE MOVING THROUGH THE UPPER GREAT LAKES
REGION AT THE START OF THE LONG TERM PERIOD AND LEAD TO THE
DEVELOPMENT OF A WEAK LOW OVER EASTERN LOWER MICHIGAN AND LAKE
HURON ON MONDAY NIGHT. THE SLOW SHIFT OF THE UPPER TROUGH AND
SURFACE LOW EAST-NORTHEAST ON MONDAY NIGHT INTO TUESDAY WILL BRING
A GRADUAL DECREASE IN PRECIPITATION/CLOUDS FROM WEST TO EAST
MONDAY NIGHT INTO TUESDAY. WITH DEEP MOISTURE WRAPPING AROUND THE
SURFACE LOW OVER EASTERN UPPER MICHIGAN...EXPECT THE BEST
OPPORTUNITY FOR MODERATE RAINFALL (LIKELY POPS) THERE ON MONDAY
NIGHT. THE CLOUDS SHOULD REMAIN THROUGH THE DAY OVER THE EAST
(MAINLY EAST OF MUNISING/MANISTIQUE) BEFORE DIMINISHING DURING THE
EVENING HOURS AS THE DEEPER MOISTURE DEPARTS. WILL CONTINUE TO HOLD
ONTO CHANCE POPS OVER THOSE EAST AREAS IN THE MORNING AND THEN
SLOWLY END THEM THROUGH THE AFTERNOON AND EVENING HOURS.
ELSEWHERE...PRECIPITATION CHANCES WILL BE DEPENDANT ON HOW QUICKLY
THE LOW LEVEL MOISTURE DEPARTS FROM WEST TO EAST. THINK THE FAR
WESTERN CWA MAY START SEEING SOME BREAKS IN THE CLOUDS DURING THE
EVENING AND EARLY OVERNIGHT HOURS...AS DRIER AIR WRAPS INTO THE
AREA. CLOUDS WILL THEN QUICKLY DIMINISH THROUGH TUESDAY MORNING.
THE CENTRAL CWA WILL LIKELY STAY SOCKED IN WITH LOW CLOUDS THROUGH
TUESDAY MONRING HOURS...ESPECIALLY OVER THE NORTH CENTRAL...WHERE
NORTHERLY WINDS WILL AID UPSLOPE CLOUDS AND DRIZZLE/-RA BEFORE
DIMINISHING IN THE AFTERNOON. IN ADDITION TO THE LOW CLOUDS AND RAIN
SHOWERS...NORTHERLY WINDS WILL BE ON THE INCREASE THROUGH THE NIGHT
AND REMAIN GUSTY THROUGH TUESDAY...ESPECIALLY OVER THE CENTRAL AND
EASTERN CWA...WHERE WINDS WILL GUST TO THE 15-25KT RANGE. THESE
GUSTY WINDS...CLOUDY SKIES...AND TEMPERATURES IN THE 50S WILL
LEAD TO A VERY FALL LIKE START TO TUESDAY OVER PORTIONS OF THE U.P.
FINALLY FOR TUESDAY...THERE IS A POTENTIAL FOR A HIGH SWIM RISK FOR
MARQUETTE AND ESPECIALLY ALGER COUNTY AND WILL ADD A MENTION TO THE
HWO.
FOR THE REST OF THE WORK WEEK...THE UPPER LOW BRIEFLY CLOSES OFF
OVER SOUTHERN QUEBEC AND THE EASTERN GREAT LAKES ON
WEDNESDAY/THURSDAY BEFORE LIFTING NORTHEAST ON FRIDAY. THIS WILL
LEAD TO NORTHWESTERLY FLOW ALOFT AND ALLOW A SURFACE HIGH PRESSURE
RIDGE TO SLOWLY SHIFT EAST ACROSS THE CWA. A SECONDARY SHORTWAVE
DROPPING SOUTHEAST ACROSS THE CWA COULD PRODUCE SOME CLOUDS AND A
FEW SPRINKLES OVER PORTIONS OF WESTERN/CENTRAL UPPER MICHIGAN ON
TUESDAY NIGHT INTO WEDNESDAY MORNING...OTHERWISE EXPECT THE WAVES
TO STAY TO THE EAST OF THE CWA. THE INCREASING INFLUENCE OF THE
SURFACE HIGH WILL BRING GRADUALLY DIMINISHING WINDS AND MOSTLY
CLEAR SKIES FOR WEDNESDAY AFTERNOON THROUGH FRIDAY NIGHT. THE
NORTHERLY FLOW ALOFT WILL KEEP 850MB TEMPS A FEW DEGREES BELOW
NORMAL AND EXPECT THE DAYTIME HIGHS TO BE SIMILAR (ESPECIALLY NEAR
LAKE SUPERIOR). HIGHS OVER INTERIOR LOCATIONS WILL BE IN THE
70S...WHILE LOCATIONS NEAR LAKE SUPERIOR WILL BE IN THE UPPER 60S.
HEADING INTO NEXT WEEKEND...THE UPPER TROUGH THAT COMES ONSHORE OVER
THE PACIFIC NORTHWEST ON TUESDAY WILL BREAK DOWN THE UPPER RIDGE
OVER THE ROCKIES AND SHIFT EAST TOWARDS THE UPPER GREAT LAKES
REGION. LATEST TREND IN THE MODELS IS FOR A LITTLE LATER ARRIVAL
THAN SHOWN YESTERDAY...WHICH SHOULD KEEP MUCH OF SATURDAY DRY AS
THE SURFACE HIGH HOLDS ON. THE PRECIPITATION CHANCES WILL BE ON THE
INCREASE SATURDAY NIGHT AND INTO SUNDAY...AS THE SURFACE RIDGE
DEPARTS AND THE UPPER LEVEL DISTURBANCE MOVES TOWARDS THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY EVENING)
ISSUED AT 130 AM EDT MON AUG 11 2014
AREAS OF RAIN AND POSSIBLY A THUNDERSTORM WILL LOWER CONDITIONS INTO
THE MVFR RANGE BY MON MORNING AT CMX AND IWD. LOWER CLOUDS BEHIND
THE FRONT SHOULD DROP CONDITIONS INTO THE IFR RANGE AT CMX/IWD MON
MORNING AND IN THE AFTERNOON AT SAW. SLOW IMPROVEMENT TO MVFR
CONDITIONS AS RAIN MOVES OUT AT CMX AND IWD MON EVENING BUT
CONTINUES TO LINGER AT SAW WHERE CONDITIONS WILL REMAIN IFR
INTO MON EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 404 PM EDT SUN AUG 10 2014
A COLD FRONT WILL MOVE ACROSS THE LAKE TONIGHT INTO MONDAY. BEHIND
THE COLD FRONT...NORTH WINDS WILL INCREASE MON AND GUST TO MORE THAN
20 KT MON NIGHT INTO TUE...PRODUCING WAVES UP TO 7 FT. HIGH PRESSURE
BUILDING INTO THE AREA BY WED NIGHT WILL ALLOW WINDS TO ONCE AGAIN
SUBSIDE TO BELOW 15 KT BY LATE WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1205 AM CDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 244 PM CDT SUN AUG 10 2014
AN UNSETTLED WEATHER PATTERN EXISTS ACROSS CENTRAL NOAM...WITH A
STRONG WAVE ENTERING WRN HUDSON BAY. THE TROUGH ASSOCIATED WITH THIS
UPPER LOW EXTENDS SOUTH INTO NRN MO. WITHIN THIS TROUGH THERE AREA A
COUPLE OF UPPER LOWS...A WEAKENING ONE OVER CENTRAL MN THAT BROUGHT
THE HEAVY RAINS TO WRN MN LAST NIGHT WITH AN MCV DOWN OVER CENTRAL
IA. AT THE SFC...OBS SHOW A WEAK LOW OVER CENTRAL MN UNDER THE
WEAKENING UPPER LOW. AT 2 PM...THE COLD FRONT EXTENDED SOUTH FROM
THE LOW THROUGH LITCHFIELD...WINDOM...AND INTO NW IA. THE MOST
WIDESPREAD PRECIPITATION THROUGH TONIGHT IS EXPECTED NORTH OF THE
MPX AREA WITH THE CENTRAL MN UPPER LOW AND WELL SOUTH OF MN/WI WITH
THE MCV. WE HAVE SEEN AN UNCAPPED 500-1000 J/KG OF MLCAPE DEVELOP
ALONG THE FRONT...WHICH HAS PROMOTED THE DEVELOPMENT OF A BROKEN
LINE OF STORMS ACROSS MN. HRRR AND MEMBERS 1 AND 3 OF THE HOPWRF
HAVE HAD A GOOD HANDEL ON THINGS TODAY...SO FOLLOWED THOSE MODELS
FOR TRACKING SHOWERS/STORMS ACROSS THE AREA. THIS RESULTED IN
SLOWING THE EWRD PROGRESSION OF POPS INTO WI...WHICH MAKES SENSE AS
ONCE AGAIN WE HAVE SEEN DEWPS OUT EAST DROP INTO THE MID 50S...DRY
AIR OUT THERE HAS BEEN VERY HESITANT TO LEAVE INDEED. BESIDE SLOWING
THE PROGRESSION OF POPS TO THE EAST...ALSO DECREASED POPS OVER WI
OVERNIGHT...AS SHOWERS REALLY LOOK TO LOOSE THEIR DEFINITION AFTER
SUNSET...WITH BEST FORCING WITH THE UPPER LOWS GOING INTO NRN WI AND
NRN IL OVERNIGHT. ALSO RESTRICTED POPS TO JUST WRN WI FOR MONDAY AND
HELD THEM INTO THE CHANCE CATEGORY AS WELL...AS UPPER WAVE DROPPING
DOWN OUT OF CANADA TONIGHT HEADS FOR CENTRAL WI MONDAY AFTERNOON. BY
THEN...BEST MOISTURE WILL BE MAINLY EAST OF THE MPX AREA...WITH
CURRENT REDUCED POPS POSSIBLY EVEN A BIT OVERDONE FOR MONDAY
AFTERNOON.
BESIDE BABYSITTING THE PRECIP ACROSS ERN AREAS TONIGHT...WILL ALSO
HAVE TO WATCH FOR FOG DEVELOPMENT OUT IN WRN MN. WE SAW A GOOD SWATH
OF 1-4+ INCHES OF RAIN OUT THERE OVERNIGHT AND AS WE GO THROUGH THE
NIGHT TONIGHT...SKIES WILL BEGIN TO CLEAR. HOWEVER...THIS CLEARING
WILL ALSO BE ACCOMPANIED BY DECREASING DEWPOINTS AND FAIRLY
PERSISTENT LIGHT NW WINDS. LEFT FOG OUT OF GRIDS FOR NOW THINKING
THESE NW WINDS WOULD KEEP THE ATMO MIXED ENOUGH TO KEEP FOG FROM
FORMING...BUT THEY WILL BE SUSCEPTIBLE TO FOG FORMATION GIVEN THE
RECENT HEAVY RAIN.
FOR MONDAY...OTHER THAN THE THREAT FOR SOME ISO/SCT STORMS OVER WRN
WI IN THE AFTERNOON...IT WILL BE YET ANOTHER STELLAR SUMMER DAY AS
SKIES CLEAR OUT...TEMPS WARM INTO THE MID/UPPER 70S...DEWPOINTS FALL
INTO THE 50S...ALL TOPPED OFF WITH A FRESH NNW WIND THAT WILL BE
GUSTING TO BETWEEN 20 AND 25 MPH.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 244 PM CDT SUN AUG 10 2014
DRY WEATHER WILL CONTINUE THROUGH MUCH OF THE PERIOD UNTIL WARM
MOIST AIR RETURNS ACROSS THE REGION BY THE END OF THE WEEK. IN THE
MEAN TIME EXPECT LITTLE CHANGE FROM THE WEATHER EXPERIENCED OVER THE
PAST COUPLE OF WEEKS.
FROM A BROAD BRUSHED PERSPECTIVE...IN ORDER TO MAKE A CONFIDENT
FORECAST FOR WIDESPREAD PRECIPITATION ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY DURING THE WARM SEASON YOU NEED EITHER LARGE SCALE
ASCENT IN THE FORM OF UPPER LEVEL DIVERGENCE...OR MORE COMMONLY LOW
LEVEL CONVERGENCE AND MOISTURE TRANSPORT ACROSS A FRONTAL BOUNDARY
FROM THE LOW LEVEL JET. OVER THE PAST FEW WEEKS NEITHER MN NOR WI
HAVE HAD EITHER...AND AS A RESULT THE WEATHER HAS BEEN NOTICEABLY
DRY.
A 36HR LOOP OF NORTH AMERICAN WATER VAPOR IMAGERY...TOGETHER WITH
GFS 500MB HEIGHTS AND WINDS SHOWED THE ACTIVE STORM TRACK SITUATED
TO THE NORTH ACROSS CENTRAL CANADA...WHILE RECURRING AFTERNOON
CONVECTION FIRED ACROSS THE CENTRAL CONUS ON THE LEE SIDE OF THE
ROCKIES OWING TO UPSLOPE FLOW. AS THE NIGHT PROGRESSED...THE
CONVECTION DRIFTED EASTWARD ACROSS THE PLAIN STATES OF NE AND KS.
ALTHOUGH ISOLATED AREAS OF WESTERN MN DID PICK UP HEALTHY RAINFALL
TOTALS OVER THE PAST 24HRS...THE COVERAGE WAS LIMITED TO A
RELATIVELY SMALL AREA...SIMILAR TO THE ISOLATED HEAVY RAIN THAT FELL
IN WESTERN WI THE PREVIOUS WEEK.
IN THE WAKE OF A WASHED OUT FRONTAL PASSAGE...THE REMAINDER OF THE
WORK WEEK WILL BE DRY AS NORTHWEST FLOW AND SURFACE HIGH PRESSURE
PERSIST ACROSS THE REGION. ON THURSDAY ANOTHER MCS WILL TRICKLE DOWN
THE MISSOURI RIVER VALLEY AND COULD CLIP THE SOUTHWESTERN PART OF
THE CWA. BY THE TIME THE WEEKEND ROLLS AROUND...EXTENDED MODELS
CONTINUE TO SHOW A TRANSITION TO A MORE ZONAL UPPER LEVEL PATTERN
WITH LOW LEVEL MOISTURE RETURNING FROM THE SOUTH. THIS WOULD
INCREASE THE POTENTIAL FOR PRECIP ACROSS THE REGION. IF THIS MODEL
SOLUTION PANS OUT HAVE FAIRLY HIGH CONFIDENCE THAT MOST OF THE
REGION WOULD PICK UP MEASURABLE RAINFALL DURING THE SATURDAY/SUNDAY
TIMEFRAME...BUT WILL NOT GO HIGHER THAN GUIDANCE WITH PRECIP CHANCES
UNTIL WE GET CLOSER TO THE EVENT CONSIDERING THE 12Z ECMWF FOCUSES
THE PRECIP TO THE SOUTHWEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1148 PM CDT SUN AUG 10 2014
CONFIDENCE IS INCREASING FOR IFR OR MVFR CIGS/VISIBILITIES
OVERNIGHT INTO EARLY MONDAY WITH DETERIORATING TRENDS AT TAF
ISSUANCE OVER CENTRAL MN. LOW PRESSURE OVER THE MSP METRO WILL
SLOWLY PUSH EAST OVERNIGHT ALLOWING THE MOISTURE RESPONSIBLE FOR
THE DETERIORATING CONDITIONS NEAR STC TO ROTATE SOUTHEAST. A FEW
SHOWERS ARE ALSO POSSIBLE...PARTICULARLY OVER FAR EASTERN MN AND
WESTERN WI WHICH MAY HELP TO IMPROVE CONDITIONS TEMPORARILY. AXN
AND RWF ARE PROBABLY A BIT TOO FAR WEST TO EXPERIENCE MVFR
CONDITIONS ALTHOUGH THERE IS A SMALL WINDOW LATE TONIGHT AT RWF.
EAU SHOULD REMAIN VFR FOR TONIGHT...BUT COULD DETERIORATE MONDAY
MORNING AS THE LOW PASSES TO THE EAST.
KMSP...VFR AT TAF ISSUANCE TIME...BUT CONDITIONS SHOULD DETERIORATE
QUITE QUICKLY AROUND 06Z WITH QUITE A FEW STATIONS REPORTING CIGS
BETWEEN 010 AND 015 JUST TO THE NORTH. DRIER AIR WILL BEGIN TO
WORK SOUTH BETWEEN 13-14Z...WITH VFR CONDITIONS RETURNING
THEREAFTER.
/OUTLOOK FOR KMSP/
TUE...VFR. WINDS NW 5-10 KTS.
WED...VFR. WINDS W 5-10 KTS.
THU...VFR. WINDS SE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...JRB
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1159 PM CDT Sun Aug 10 2014
.MESOSCALE DISCUSSION...
Issued at 602 PM CDT SUN AUG 10 2014
Recent radar trends suggest that thunderstorms are struggling to
expand in coverage despite the presence of boundaries and an
incoming short wave trough from the northwest. The orientation and
movement to the boundaries is likely playing a role in the lack of
coverage. One boundary which extends from near Osceola to
Hartville is moving against low level shear vectors. Low level
destructive interference is likely squashing new updraft
development. A second boundary is more west/east oriented and is
seeping south from extreme northern Bourbon County into the
Osceola area. We have seen weak convection develop along this
feature as shear vectors are oriented more parallel (not
inhibiting updrafts). Another negative across central Missouri is
an overall lack of instability.
As we head into this evening, the current widely scattered
convection will tend to slowly weaken with waning instability. We
will see the continued potential for weaker convective development
as that west/east boundary and upper level wave push south and
east. Overall, we have lowered PoPs over most areas, with the
biggest adjustments to southwestern Missouri and extreme
southeastern Kansas. Any threat for strong to severe storms will
generally occur over the next hour or two and be associated with
convection moving southeast across portions of south-central
Missouri. Despite lower-end deep layer shear, one cell has shown
supercellular structures for the last couple of hours. Thus, we
will maintain a limited hail and wind threat into early this
evening.
&&
.SHORT TERM...(This Evening through Monday)
Issued at 300 PM CDT SUN AUG 10 2014
Warm and humid conditions are in place across the region this
afternoon. Starting to see an uptick in convection during the
past hour, particularly across central Missouri. This is in
response to destabilization due to daytime heating and upper level
energy rotating around an area of low pressure located near Kansas
City. Water vapor imagery and RAP initializations of mid level
vorticity indicate multiple lobes of vorticity emanating from this
upper low. As a result, we should continue to see a gradual
increase in showers and storms across much of the Missouri Ozarks
heading into this evening. The aforementioned upper low and a cold
front moving into the region from the northwest will maintain
scattered showers and storms across the region into much of
tonight. Overnight the better rain chances should begin to shift
to the southeast and east.
High PW air in place (around 1.9" according to the SPC
mesoanalysis page) will result in locally heavy rainfall with this
activity. Deep layer shear remains on the weak side, around 25-30
kt, while both surface based and mixed layer CAPE values are
nearing 3000 J/kg. This should result in a mainly multicell
convective mode with an isolated risk for wet microbursts.
The cold front will exit to the east/southeast on Monday with rain
chances ending during the morning hours.
.LONG TERM...(Monday Night through Sunday)
Issued at 300 PM CDT SUN AUG 10 2014
A nice stretch of weather is expected across the area from Monday
night through Thursday as large area of Canadian surface high
pressure dominates our weather regime. Temperatures will some 7 to
10 degrees below average with comfortable humidity levels.
Temperatures and humidity will rebound back to typical mid-August
values late this week through next weekend as the upper level
pattern flattens a bit. Upper level ridging will attempt to build
into the region from the southwest, meanwhile energy in the
northern stream will threaten to enter from the northwest. Day to
day continuity from individual medium range models have been
lacking (one run wet, the next run dry), however the consensus
suggests that the door will be open to mesoscale convective
systems (MCS) entering from the northwest. As a result, have
continued low end chance PoPs from Friday through the weekend
until finer scale details can be resolved.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday Night)
Issued at 1147 PM CDT SUN AUG 10 2014
An approaching upper level disturbance will bring increasing
clouds to the area overnight. The best case scenario is that we
will see scattered areas of MVFR ceilings and perhaps some MVFR
visibilities later tonight. However, some models continue to
indicate the potential for LIFR ceilings and fog late tonight. We
have taken a middle of the road approach at this point and gone
with strictly MVFR ceilings at Joplin and Branson. We did maintain
a TEMPO group for LIFR ceilings at Springfield due to upslope flow
along the Ozark Plateau. Isolated rain showers will also be
possible across the region, but coverage will be too limited to
include in the TAFs. Flight categories will then quickly improve
Monday morning with VFR expected by late morning.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
MESOSCALE...Schaumann
SHORT TERM...Gagan
LONG TERM...Gagan
AVIATION...Schaumann
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1253 PM CDT MON AUG 11 2014
.SYNOPSIS...
ISSUED AT 235 AM CDT MON AUG 11 2014
AT THE SURFACE...HIGH PRESSURE EXTENDED FROM SOUTHEAST
SASKATCHEWAN TO NORTHEAST COLORADO. THERE WAS A STATIONARY FRONT
ACROSS THE SOUTHERN PLAINS WITH AN EXTENSION THROUGH A WEAK
FRONT/TROUGH ON THE EASTERN PLAINS AND FOOTHILLS OF WYOMING AND
COLORADO. ANOTHER BOUNDARY OR FRONT COULD BE SEEN IN THE GOES
INFRA-RED IMAGERY WITH A NARROW BAND OF MIDDLE AND HIGH CLOUDS
ACROSS SOUTHERN SOUTH DAKOTA.
AN UPPER LEVEL DISTURBANCE ACROSS WESTERN MEXICO IS FORECAST TO
LIFT NORTH THROUGH THE SOUTHWESTERN U.S. AND AFFECT WESTERN/NCNTL
NEB WITH SCATTERED SHOWERS AND THUNDERSTORMS THURSDAY AND FRIDAY.
THE ECM IS THE WET MODEL FORECASTING AROUND 1 INCH OF RAIN ACROSS
MOST OF THE FORECAST AREA.
&&
.UPDATE...
ISSUED AT 1142 AM CDT MON AUG 11 2014
ISOLATED SHOWERS AND THUNDERSTORMS WERE ADDED INTO THE FORECAST FOR
THE WESTERN PART OF THE FORECAST AREA...GENERALLY WEST OF A LINE
FROM MERRIMAN THROUGH NORTH PLATTE. CLOUDS HAD DEVELOPED ALONG A
BOUNDARY ALOFT THIS MORNING...WHERE THE RAP SHOWS INCREASED
CONVERGENCE IN THE 850MB TO 700MB LAYER IN THE GENERAL AREA
THROUGHOUT THE AFTERNOON. MOISTURE IS FAIRLY SHALLOW AND LIMITED
SO DON/T EXPECT MORE THAN ISOLATED TO SCATTERED ACTIVITY. THE LIFT
AND MOISTURE DIMINISH BY 00Z THIS EVENING WITH THE NEW FORECAST
TRENDING TO LIMIT PRECIPITATION CHANCES BY THIS EVENING AS WELL.
UPDATE ISSUED AT 915 PM CDT MON AUG 11 2014
FORECAST WAS UPDATED FOR THIS MORNING FOR THE DISSIPATION OF FOG
ACROSS MOST AREAS. VISIBLE SATELLITE SHOWED A PATCH OF CLOUDS FROM
EAST CENTRAL LINCOLN COUNTY UP THROUGH NORTHEAST CUSTER
COUNTY...BUT BELIEVE THIS WAS LOW STRATUS RATHER THAN FOG DUE TO
OBSERVATION AT KBBW OF 300FT CEILINGS. HOWEVER AREA WEBCAMS DO
SHOW SOME LIGHT FOG /VISIBILITY AROUND 5SM OVER SOUTHWEST CUSTER
COUNTY. THIS IS LIKELY BEING OBSERVED UNDER MUCH OF THE AREA.
OTHER LOCATIONS WERE ALSO SEEING SOME HAZY CONDITIONS THIS
MORNING. ALL SHOULD MIX OUT AND DISSIPATE BY LATER THIS MORNING.
UPDATE ISSUED AT 630 AM CDT MON AUG 11 2014
SATELLITE AND METAR OBSERVATIONS INDICATE PATCHY FOG HAS FORMED
OVER CENTRAL AND PART OF SOUTHWEST NEBRASKA. WITH SIMILAR MOISTURE
AND WIND CONDITIONS AROUND THE AREA...THERE IS NO REASON TO THINK
THAT IT WILL NOT ALSO AFFECT NORTH CENTRAL AND SOUTHWEST NEBRASKA.
THEREFORE...WE HAVE UPDATED THE FORECAST TO REFLECT PATCHY FOG.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 235 AM CDT MON AUG 11 2014
WITH HIGH PRESSURE THE DOMINANT FEATURE AT THE SURFACE AND ALOFT...
LOW LEVEL FLOW WILL BECOME EAST TO SOUTHEAST BY THIS EVENING AND THE
LEE SIDE TROUGH WILL BEGIN REDEVELOPING. HOWEVER...THE FETCH DOES
NOT REACH A SIGNIFICANT MOISTURE SOURCE YET AND PRECIPITATION IS
UNLIKELY TODAY OR TONIGHT IN CENTRAL NEBRASKA...THE SANDHILLS OR THE
EASTERN PANHANDLE. TEMPERATURES ARE TODAY AND TONIGHT ARE EXPECTED
TO BE BELOW AVERAGE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 235 AM CDT MON AUG 11 2014
CANADIAN HIGH PRESSURE WILL MOVE OFF EAST TUESDAY SETTING UP
MOISTURE RETURN. BY WEDNESDAY DEW POINTS INCREASE INTO THE LOWER
60S. THERE APPEARS TO BE SUFFICIENT INSTABILITY FOR TSTM DEVELOPMENT
BY WEDNESDAY EVENING. ALL MODELS DEVELOP CONVECTION NORTH WEDNESDAY
NIGHT AND IT WOULD APPEAR TO BE DRIVEN BY WARM AIR ADVECTION
ASSOCIATED WITH AN H700MB LOW MOVING THROUGH THE ROCKIES.
THE GENESIS OF THIS H700MB LOW IS A SUBTROPICAL DISTURBANCE
CURRENTLY ACROSS WRN MEXICO. THE DISTURBANCE LIFTS NORTH THROUGH
THE SWRN U.S. ARRIVING IN WRN/NCNTL NEB THURSDAY/FRIDAY. THIS
WOULD LIKELY BE THE BEST CHANCE FOR RAIN DURING THE NEXT 7 DAYS
WITH MEAN RH 850-300MB INCREASING TO 70 TO 80 PERCENT BOTH DAYS. A
CLOSED H700MB LOW SHOULD TRACK THROUGH THE FCST AREA THURSDAY AND
SLOW UP LASTING THROUGH FRIDAY. THE ECM IS EVEN SLOWER WITH RAIN
CHANCES LASTING THROUGH SATURDAY.
THEREAFTER...AN UPPER LOW...CURRENTLY ACROSS THE GULF
ALASKA...SHOULD DROP THROUGH THE NRN ROCKIES FRIDAY AND MOVE THROUGH
THE NRN PLAINS SATURDAY. THIS WOULD DRAW PACIFIC AIR THROUGH WYOMING
AND THE NEB PANHANDLE SHUNTING MOISTURE EAST OF THE FCST AREA AS
SHOWN BY THE MODELS. THIS IS NOT ALWAYS THE CASE THOUGH. WEAK
PACIFIC COLD FRONTS CAN STALL LEAVING A BROAD AREA OF SFC LOW
PRESSURE WHICH WOULD POOL MOISTURE INCREASING RAIN CHANCES. AS SUCH
THE GFS AND ECM SHOW A DRY LINE ALONG HIGHWAY 61 WITH DEW POINTS
INCREASING TO THE MID 60S SUNDAY TO THE EAST.
THE POP FORECAST STARTS WITH ISOLATED CHANCES LATE WEDNESDAY
AFTERNOON IN THE PANHANDLE WHICH INCREASE TO NEAR 40 THURSDAY NIGHT
AND ISOLATED FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 152 PM CDT MON AUG 11 2014
HIGH PRESSURE OVER THE NORTHERN AND CENTRAL PLAINS HAS LED TO
GENERALLY QUIET WEATHER ACROSS NEBRASKA. CLOUDS HAD DEVELOPED
THROUGH THE DAY ON THE BACK SIDE OF THE SURFACE HIGH WHERE MORE
MOISTURE WAS IN PLACE. LOOKING FOR SOME ISOLATED TO SCATTERED
CONVECTION THIS AFTERNOON...BUT ACTIVITY SHOULD BE WEST OF A LINE
FROM AROUND MERRIMAN TO NORTH PLATTE. ALTHOUGH THERE IS A CHANCE
FOR SHOWERS OR STORMS AT KLBF...WITH ACTIVITY EXPECTED TO BE
ISOLATED...DIDN/T HAVE THE CONFIDENCE TO ADD ANY CONVECTIVE
CIRCUMSTANCES IN THE FORECAST AND WILL JUST MONITOR THROUGH THE
AFTERNOON. OTHERWISE...WITH HIGH PRESSURE IN CONTROL THE WEATHER
SHOULD BE QUIET WITH GENERALLY LIGHT WINDS. THERE IS A CONCERN IF
FOG WILL DEVELOP TONIGHT ON THE BACKSIDE OF THE SURFACE HIGH. THE
LOCAL AREA WILL BE IN THE FAVORED REGION...BUT DON/T HAVE THE
CONFIDENCE THAT THERE WILL BE ENOUGH BOUNDARY LAYER MOISTURE FOR
DEVELOPMENT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BROOKS
SYNOPSIS...CDC
SHORT TERM...SPRINGER
LONG TERM...CDC
AVIATION...BROOKS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1143 AM CDT MON AUG 11 2014
.SYNOPSIS...
ISSUED AT 235 AM CDT MON AUG 11 2014
AT THE SURFACE...HIGH PRESSURE EXTENDED FROM SOUTHEAST
SASKATCHEWAN TO NORTHEAST COLORADO. THERE WAS A STATIONARY FRONT
ACROSS THE SOUTHERN PLAINS WITH AN EXTENSION THROUGH A WEAK
FRONT/TROUGH ON THE EASTERN PLAINS AND FOOTHILLS OF WYOMING AND
COLORADO. ANOTHER BOUNDARY OR FRONT COULD BE SEEN IN THE GOES
INFRA-RED IMAGERY WITH A NARROW BAND OF MIDDLE AND HIGH CLOUDS
ACROSS SOUTHERN SOUTH DAKOTA.
AN UPPER LEVEL DISTURBANCE ACROSS WESTERN MEXICO IS FORECAST TO
LIFT NORTH THROUGH THE SOUTHWESTERN U.S. AND AFFECT WESTERN/NCNTL
NEB WITH SCATTERED SHOWERS AND THUNDERSTORMS THURSDAY AND FRIDAY.
THE ECM IS THE WET MODEL FORECASTING AROUND 1 INCH OF RAIN ACROSS
MOST OF THE FORECAST AREA.
&&
.UPDATE...
ISSUED AT 1142 AM CDT MON AUG 11 2014
ISOLATED SHOWERS AND THUNDERSTORMS WERE ADDED INTO THE FORECAST FOR
THE WESTERN PART OF THE FORECAST AREA...GENERALLY WEST OF A LINE
FROM MERRIMAN THROUGH NORTH PLATTE. CLOUDS HAD DEVELOPED ALONG A
BOUNDARY ALOFT THIS MORNING...WHERE THE RAP SHOWS INCREASED
CONVERGENCE IN THE 850MB TO 700MB LAYER IN THE GENERAL AREA
THROUGHOUT THE AFTERNOON. MOISTURE IS FAIRLY SHALLOW AND LIMITED
SO DON/T EXPECT MORE THAN ISOLATED TO SCATTERED ACTIVITY. THE LIFT
AND MOISTURE DIMINISH BY 00Z THIS EVENING WITH THE NEW FORECAST
TRENDING TO LIMIT PRECIPITATION CHANCES BY THIS EVENING AS WELL.
UPDATE ISSUED AT 915 PM CDT MON AUG 11 2014
FORECAST WAS UPDATED FOR THIS MORNING FOR THE DISSIPATION OF FOG
ACROSS MOST AREAS. VISIBLE SATELLITE SHOWED A PATCH OF CLOUDS FROM
EAST CENTRAL LINCOLN COUNTY UP THROUGH NORTHEAST CUSTER
COUNTY...BUT BELIEVE THIS WAS LOW STRATUS RATHER THAN FOG DUE TO
OBSERVATION AT KBBW OF 300FT CEILINGS. HOWEVER AREA WEBCAMS DO
SHOW SOME LIGHT FOG /VISIBILITY AROUND 5SM OVER SOUTHWEST CUSTER
COUNTY. THIS IS LIKELY BEING OBSERVED UNDER MUCH OF THE AREA.
OTHER LOCATIONS WERE ALSO SEEING SOME HAZY CONDITIONS THIS
MORNING. ALL SHOULD MIX OUT AND DISSIPATE BY LATER THIS MORNING.
UPDATE ISSUED AT 630 AM CDT MON AUG 11 2014
SATELLITE AND METAR OBSERVATIONS INDICATE PATCHY FOG HAS FORMED
OVER CENTRAL AND PART OF SOUTHWEST NEBRASKA. WITH SIMILAR MOISTURE
AND WIND CONDITIONS AROUND THE AREA...THERE IS NO REASON TO THINK
THAT IT WILL NOT ALSO AFFECT NORTH CENTRAL AND SOUTHWEST NEBRASKA.
THEREFORE...WE HAVE UPDATED THE FORECAST TO REFLECT PATCHY FOG.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 235 AM CDT MON AUG 11 2014
WITH HIGH PRESSURE THE DOMINANT FEATURE AT THE SURFACE AND ALOFT...
LOW LEVEL FLOW WILL BECOME EAST TO SOUTHEAST BY THIS EVENING AND THE
LEE SIDE TROUGH WILL BEGIN REDEVELOPING. HOWEVER...THE FETCH DOES
NOT REACH A SIGNIFICANT MOISTURE SOURCE YET AND PRECIPITATION IS
UNLIKELY TODAY OR TONIGHT IN CENTRAL NEBRASKA...THE SANDHILLS OR THE
EASTERN PANHANDLE. TEMPERATURES ARE TODAY AND TONIGHT ARE EXPECTED
TO BE BELOW AVERAGE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 235 AM CDT MON AUG 11 2014
CANADIAN HIGH PRESSURE WILL MOVE OFF EAST TUESDAY SETTING UP
MOISTURE RETURN. BY WEDNESDAY DEW POINTS INCREASE INTO THE LOWER
60S. THERE APPEARS TO BE SUFFICIENT INSTABILITY FOR TSTM DEVELOPMENT
BY WEDNESDAY EVENING. ALL MODELS DEVELOP CONVECTION NORTH WEDNESDAY
NIGHT AND IT WOULD APPEAR TO BE DRIVEN BY WARM AIR ADVECTION
ASSOCIATED WITH AN H700MB LOW MOVING THROUGH THE ROCKIES.
THE GENESIS OF THIS H700MB LOW IS A SUBTROPICAL DISTURBANCE
CURRENTLY ACROSS WRN MEXICO. THE DISTURBANCE LIFTS NORTH THROUGH
THE SWRN U.S. ARRIVING IN WRN/NCNTL NEB THURSDAY/FRIDAY. THIS
WOULD LIKELY BE THE BEST CHANCE FOR RAIN DURING THE NEXT 7 DAYS
WITH MEAN RH 850-300MB INCREASING TO 70 TO 80 PERCENT BOTH DAYS. A
CLOSED H700MB LOW SHOULD TRACK THROUGH THE FCST AREA THURSDAY AND
SLOW UP LASTING THROUGH FRIDAY. THE ECM IS EVEN SLOWER WITH RAIN
CHANCES LASTING THROUGH SATURDAY.
THEREAFTER...AN UPPER LOW...CURRENTLY ACROSS THE GULF
ALASKA...SHOULD DROP THROUGH THE NRN ROCKIES FRIDAY AND MOVE THROUGH
THE NRN PLAINS SATURDAY. THIS WOULD DRAW PACIFIC AIR THROUGH WYOMING
AND THE NEB PANHANDLE SHUNTING MOISTURE EAST OF THE FCST AREA AS
SHOWN BY THE MODELS. THIS IS NOT ALWAYS THE CASE THOUGH. WEAK
PACIFIC COLD FRONTS CAN STALL LEAVING A BROAD AREA OF SFC LOW
PRESSURE WHICH WOULD POOL MOISTURE INCREASING RAIN CHANCES. AS SUCH
THE GFS AND ECM SHOW A DRY LINE ALONG HIGHWAY 61 WITH DEW POINTS
INCREASING TO THE MID 60S SUNDAY TO THE EAST.
THE POP FORECAST STARTS WITH ISOLATED CHANCES LATE WEDNESDAY
AFTERNOON IN THE PANHANDLE WHICH INCREASE TO NEAR 40 THURSDAY NIGHT
AND ISOLATED FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 630 AM CDT MON AUG 11 2014
LIMITED COVERAGE OF BR/FG WILL CONTINUE AFFECTING CENTRAL AND
WESTERN NEBRASKA. SINCE IT HAS ALREADY SHOWN UP AT LBF...WE WILL
INCLUDE BCFG IN THE TERMINAL FORECAST WITH VISIBILITY AT OR ABOVE
3SM AND A TEMPO TO 1SM. WITH NO CLOUDINESS ABOVE THE SURFACE...IT
SHOULD CLEAR OUT QUICKLY THIS MORNING. THEN...FOR THE REST OF THE
DAY... CEILING AND VISIBILITY WILL BE UNLIMITED. FOR
TONIGHT...THERE IS A POSSIBILITY FOR SIMILAR CONDITIONS AND FOG IS
POSSIBLE. AGAIN... THOUGH...COVERAGE WILL BE LIMITED.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BROOKS
SYNOPSIS...CDC
SHORT TERM...SPRINGER
LONG TERM...CDC
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
325 PM PDT MON AUG 11 2014
.SYNOPSIS...MONSOON MOISTURE PUSHING IN FROM THE SOUTHEAST WILL
RESULT IN INCREASED THUNDERSTORM COVERAGE THROUGH WEDNESDAY. DRIER
AIR WILL ONCE AGAIN GRADUALLY MOVE IN FROM THE SOUTHWEST STARTING
THURSDAY WITH THUNDERSTORM CHANCES CONFINED TO MOHAVE COUNTY BY
FRIDAY.
&&
.SHORT TERM...THROUGH TUESDAY NIGHT...
TAIL END OF LINE OF STORMS WHICH WAS OVER INYO/ESMERALDA COUNTY THIS
MORNING DID SHIFT EASTWARD AND DID AFFECT SRN NYE/CLARK COUNTIES
THIS AFTERNOON. THOSE STORMS NOW MOVING INTO LINCOLN COUNTY.
ACTIVITY IS GETTING GOING OVER MOHAVE COUNTY WITH
MORE STORMS SET TO ENTER MOHAVE COUNTY FROM COCONINO/YAVAPAI
COUNTIES. HRRR SUGGEST THE NORTHERN TWO-THIRDS OF MOHAVE COUNTY WILL
REMAIN THE MOST ACTIVE FOR THE NEXT 3-4 HOURS THEN SHIFTING
NORTHWARD ACROSS NORTHEAST CLARK AND LINCOLN COUNTIES THIS EVENING.
GUSTS OF 40-50 MPH...SMALL HAIL AND BRIEF HEAVY RAIN POSSIBLE WITH
STORMS.
FOR TUESDAY...MODELS MORE OR LESS IN GOOD AGREEMENT SHOWING AN
INVERTED TROUGH MOVING EAST ACROSS SOUTHERN ARIZONA TONIGHT AND INTO
SOUTHWEST ARIZONA LATE TUESDAY AFTERNOON. INVERTED TROUGH THEN
ENCOUNTERS A MORE WESTERLY FLOW AND LIFT NORTH ACROSS WESTERN
ARIZONA TUESDAY NIGHT/WEDNESDAY. DUE TO ADDITIONAL DYNAMICS DECIDED
TO ISSUE A FLASH FLOOD WATCH FOR THE NORTHWEST DESERT AND PLATEAU OF
MOHAVE COUNTY FROM 11 AM MST - 10 PM MST TUESDAY. TOMORROW WE WILL
BE LOOKING AT THE NEED OF EXTENDING THE WATCH INTO WEDNESDAY IF
MODELS STAY CONSISTENT.
.LONG TERM...WEDNESDAY THROUGH SUNDAY...THE SYNOPTIC PATTERN
FEATURES A LOW PRESSURE TROUGH OVER THE PACIFIC NW WEDNESDAY THAT IS
FORECAST TO MOVE INTO THE NORTHERN GREAT BASIN THURSDAY AND FRIDAY.
THE UPPER LEVEL FLOW BECOMES SOLIDLY WEST TO SOUTHWEST AS THE WEEK
WEARS ON. THE AFFECT OF THIS LARGE SCALE FEATURE ON SENSIBLE WEATHER
WITHIN THE FORECAST AREA IS TO BRING A DECREASING TREND IN
THUNDERSTORM COVERAGE.
WEDNESDAY HAS THE BEST POTENTIAL FOR SCATTERED THUNDERSTORMS ACROSS
A WIDER AREA INCLUDING LINCOLN, CLARK, MOHAVE AND EASTERN SAN BERN
COUNTIES. BEYOND WEDNESDAY, RAPID DRYING TAKES PLACE IF THE GFS
VERIFIES BUT COULD BE SOMEWHAT SLOWER PER THE ECMWF. MAINTAINED A
MENTION OF STORMS IN MOHAVE COUNTY BOTH THURSDAY AND FRIDAY BEFORE
DRYING THEM OUT COMPLETELY OVER THE WEEKEND. TEMPERATURES WILL
GENERALLY BE BELOW NORMAL MID TO LATE IN THE WEEK THEN BECOME
SEASONAL OVER THE WEEKEND.
&&
.AVIATION...FOR MCCARRAN...OUTFLOW WINDS FROM SURROUNDING STORMS
WILL CONTINUE TO AFFECT LAS VEGAS VALLEY TERMINALS INTO THE EVENING
HOURS. LOOKS LIKE WINDS WILL FAVOR A NORTHERLY DIRECTION FOR SEVERAL
HOURS BEFORE TRANSITION BACK TO OUR TYPICAL SOUTH/SOUTHWEST
DIRECTION WITH SPEEDS OF 7-11 KTS. CONVECTION SHOULD IMPACT MAINLY
THE BEATTY...MORMON MESA AND PEACH SPRINGS CORRIDORS THIS EVENING.
THERE WILL BE ANOTHER CHANCE OF SHOWERS OR TSTORM WITHIN THE
VICINITY OF THE TERMINAL TUESDAY...WHICH COULD BRING GUSTY AND
ERRATIC WINDS.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SCATTERED-BROKEN CLOUDS ALONG WITH ISOLATED TO
SCATTERED THUNDERSTORMS ACROSS ALL OF SOUTHEAST
CALIFORNIA...SOUTHERN NEVADA AND NORTHWEST ARIZONA THIS EVENING AND
AGAIN TUESDAY. WINDS WILL FAVOR TYPICAL DIURNAL WIND PATTERNS
THROUGH TUESDAY...EXCEPT NEAR THUNDERSTORMS.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS SHOULD REPORT INSTANCES OF
FLASH FLOODING...STRONG GUSTY WINDS...HAIL...AND BLOWING DUST TODAY
THROUGH TUESDAY.
&&
$$
SHORT TERM/AVIATION...PIERCE
LONG TERM...SALMEN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1156 PM EDT TUE AUG 12 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION OVERNIGHT WITH A PERIOD OF
SHOWERS AND THUNDERSTORMS. THEN LOW PRESSURE WILL STALL ACROSS
QUEBEC THROUGH FRIDAY AND KEEP AN UNSETTLED PATTERN ACROSS OUR
REGION WITH COOL TEMPERATURES AND SOME SHOWERS. TEMPERATURES WILL
BEGIN TO MODERATE BY THE WEEKEND AS LOW PRESSURE FINALLY MOVES
AWAY FROM THE AREA...ALTHOUGH A WEAK FRONT MAY PRODUCE A FEW
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AT 03Z A SHARP UPPER LEVEL TROUGH AXIS EXTENDS SOUTHWARD ACROSS
LAKE HURON...WITH AN ASSOCIATED COLD FRONTAL BOUNDARY JUST EAST OF THIS
ACROSS LAKE ERIE. MEANWHILE...A LINE OF SHOWERS AND THUNDERSTORMS
HAS DEVELOPED WITH A PRE-FRONTAL TROUGH WITH THESE MOVING INTO
CENTRAL NEW YORK. THE HRRR HAS THIS FEATURE WELL CAPTURED...AND
SHOULD PROVIDE GOOD GUIDANCE IN ADDITION TO RADAR TRENDS.
BEHIND THIS...THE COLD FRONT WILL CONTINUE TO MOVE EASTWARD...AND
ENTER WESTERN NEW YORK SHORTLY AFTER MIDNIGHT. THERE ARE SCATTERED
SHOWERS AND A FEW THUNDERSTORMS WITH THE COLD FRONT. MEANWHILE THE
APPROACHING UPPER AND MID LEVEL TROUGH AND ADDITIONAL VORTICITY
MAXIMA WILL ENTER THE REGION WITH AN INCREASING RISK OF SHOWERS
AGAIN. THERE WILL ALSO BE SOME LAKE ENHANCEMENT LATE TONIGHT AND
EARLY WEDNESDAY MORNING EAST OF LAKE ERIE AS LAKE INDUCED
EQUILIBRIUM LEVELS CLIMB TO AROUND 30K FEET...SUPPORTING SHOWERS
AND PERHAPS EVEN A THUNDERSTORM.
ON WEDNESDAY THE MORE PERSISTENT RAIN EAST OF LAKE ONTARIO WILL
END. SCATTERED SHOWERS ASSOCIATED WITH THE BASE OF THE MID LEVEL
TROUGH WILL CROSS THE REGION FROM WEST TO EAST DURING THE
MORNING...EXITING THE FAR WEST EARLY AND REACHING EAST OF LAKE
ONTARIO BY LATE MORNING OR MIDDAY. THERE MAY STILL BE SOME BRIEF
LAKE ENHANCEMENT FOR AN HOUR OR TWO EAST OF LAKES ERIE AND ONTARIO
NEAR THE TIME OF THE TROUGH PASSAGE. BY AFTERNOON EXPECT THE LAKE
PROCESS TO FLIP...WITH STABLE LAKE SHADOWS DEVELOPING WITH PEAK
HEATING. THIS WILL ALLOW A FEW DIURNALLY DRIVEN SHOWERS TO DEVELOP
INLAND FROM THE LAKES... MOST LIKELY ALONG A CONVERGENCE ZONE
FORECAST TO DEVELOP FROM THE NIAGARA FRONTIER TO THE NORTHERN
FINGER LAKES. EXPECT COVERAGE TO BE RELATIVELY SPARSE DURING THE
AFTERNOON.
HIGH TEMPERATURES ON WEDNESDAY WILL BE 5-8 DEGREES BELOW AVERAGE...
WITH LOW TO MID 70S AT LOWER ELEVATIONS AND UPPER 60S ACROSS HIGHER
TERRAIN.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
WE WILL BE UNDER THE INFLUENCE OF THE CLOSED UPPER LOW OVER SOUTHERN
QUEBEC THROUGH THE PERIOD. ALTHOUGH TOUGH TO PIN POINT BEST AREAS
FOR PRECIPITATION IN THIS PATTERN...THERE LOOKS TO BE AMPLE MOISTURE
AND SUFFICIENT COLD AIR ALOFT TO SUPPORT DIURNALLY DRIVEN
CONVECTION...ESPECIALLY ACROSS THE NORTH COUNTRY WHICH WILL BE
CLOSER TO THE UPPER LOW CENTER AND BETTER MOISTURE FIELD. WILD CARD
WITHIN THIS COLD CYCLONIC FLOW PATTERN WILL BE THE POTENTIAL FOR
LAKE INDUCED PRECIPITATION. ALTHOUGH THERE WILL BE SOME POTENTIAL
WEDNESDAY NIGHT/THURSDAY MORNING...THE GREATER LIKELIHOOD WILL BE
EAST/SOUTHEAST OF LAKE ONTARIO THURSDAY NIGHT INTO FRIDAY MORNING
WHEN THE COLDEST 850 MB AIR NEARING +4C SETTLES ACROSS THE REGION.
PERSISTENT DRY AIR CUTTING UNDERNEATH OF THE UPPER LOW WILL LIKELY
LIMIT THE ACTIVITY OFF LAKE ERIE.
TEMPERATURES THROUGH THE PERIOD SHOULD AVERAGE A SOLID 10 TO 15
DEGREES BELOW NORMAL WITH THURSDAY BEING THE COLDEST DAY WITH HIGHS
IN THE 60S...AND ONLY 50S OVER THE HIGHER TERRAIN.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MEDIUM RANGE MODELS SEEM TO BE A BIT MORE IN LINE WITH THE SHORTWAVE
ENERGY FORECAST TO DROP THROUGH THE GREAT LAKES REGION SATURDAY
NIGHT THROUGH SUNDAY. THIS GIVES A BIT MORE CONFIDENCE TO ADDING OR
INCREASING PRECIPITATION PROBABILITIES DURING THIS TIME FRAME.
CHANCES FOR ADDITIONAL SHOWERS PROBABLY STICKS AROUND SUNDAY NIGHT
BEFORE THE ATMOSPHERE DRIES SUFFICIENTLY. LOWER CONFIDENCE DEVELOPS
LATER IN THE PERIOD AS DIFFERENT DATA SETS SUGGESTING EITHER MID
LEVEL RIDGING...OR POSSIBLY MORE SHORTWAVE ENERGY MOVING INTO THE
REGION. CONTINUITY FORECAST WAS DRY AND WILL LEAVE IT THAT WAY AS
ECMWF SUGGESTS A DRIER SCENARIO.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
SHOWERS WITH A FEW EMBEDDED -TSRA WILL GRADUALLY MOVE EAST OF ROC
LATE THIS EVENING WITH AREAS OF MVFR/IFR. BEHIND THE AREA OF
CONVECTION...A PERIOD OF IFR CIGS APPEARS LIKELY AGAIN OVERNIGHT
ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER AND FINGER LAKES
WITH MOIST LOW LEVEL UPSLOPE FLOW. THERE MAY BE SOME FOG WHILE
SKIES CLEAR...WITH THIS MAINLY A RISK AT JHW...BUT CONDITIONS
SHOULD IMPROVE SOMEWHAT AS HIGH CLOUDS MOVE BACK IN.
ON WEDNESDAY THE LOW CIGS ACROSS THE HIGHER TERRAIN WILL IMPROVE TO
MVFR BY LATE MORNING WITH FURTHER IMPROVEMENT TO VFR BY AFTERNOON.
STEADIER RAIN EAST OF LAKE ONTARIO EARLY WITH LOCAL MVFR/IFR WILL
TAPER OFF. ANOTHER BROKEN BAND OF SHOWERS WILL MOVE INTO WESTERN NY
VERY EARLY WEDNESDAY MORNING THEN PROGRESS EAST ACROSS THE AREA
DURING THE DAY WITH A BRIEF PERIOD OF MVFR. SCATTERED SHOWERS AND
ISOLATED THUNDER WILL DEVELOP DURING THE AFTERNOON INLAND FROM THE
LAKES BUT COVERAGE SHOULD REMAIN RATHER SPARSE WITH VFR PREVAILING
IN MOST PLACES DURING THE AFTERNOON.
OUTLOOK...
THURSDAY NIGHT AND FRIDAY...VFR WITH A CHANCE OF MVFR IN SHOWERS
ESPECIALLY EAST OF THE LAKES.
SATURDAY...VFR.
SATURDAY NIGHT AND SUNDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
WINDS WILL BECOME MORE WESTERLY AND INCREASE LATE TONIGHT AND
WEDNESDAY BEHIND A COLD FRONT AND PRODUCE ANOTHER PERIOD OF SMALL
CRAFT ADVISORY CONDITIONS ON BOTH LAKES ERIE AND ONTARIO. WINDS
AND WAVES WILL DIMINISH FROM WEST TO EAST LATER WEDNESDAY NIGHT AS
THE PRESSURE GRADIENT RELAXES. WINDS MAY INCREASE AGAIN DURING THE
DAY THURSDAY WITH COLD AIR ALOFT ALLOWING FOR STEEP LAPSE RATES
AND EFFICIENT MOMENTUM TRANSFER OF STRONGER WINDS TO THE SURFACE.
CONDITIONS WILL BECOME MARGINALLY SUPPORTIVE OF WATERSPOUTS
WEDNESDAY MORNING ON LAKE ERIE...AND MORNING THROUGH EARLY AFTERNOON
ON LAKE ONTARIO. A BETTER CHANCE OF WATERSPOUTS WILL OCCUR LATE
WEDNESDAY NIGHT THROUGH FRIDAY MORNING AS THE COOLEST AIR ALOFT
CROSSES THE LOWER LAKES. WATERSPOUTS ARE MOST COMMON IN AND NEAR
BANDS OF LAKE EFFECT CLOUDS AND SHOWERS WHERE LOW LEVEL CONVERGENCE
IS MAXIMIZED.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM WEDNESDAY TO 2 AM EDT THURSDAY
FOR LEZ040-041.
SMALL CRAFT ADVISORY FROM 10 AM TO 8 PM EDT WEDNESDAY FOR
LEZ020.
SMALL CRAFT ADVISORY FROM 5 AM WEDNESDAY TO 2 AM EDT
THURSDAY FOR LOZ042-043.
SMALL CRAFT ADVISORY FROM 10 AM WEDNESDAY TO 5 AM EDT
THURSDAY FOR LOZ044-045.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...APFFEL
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
909 PM EDT TUE AUG 12 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION OVERNIGHT WITH A PERIOD OF
SHOWERS AND THUNDERSTORMS. THEN LOW PRESSURE WILL STALL ACROSS
QUEBEC THROUGH FRIDAY AND KEEP AN UNSETTLED PATTERN ACROSS OUR
REGION WITH COOL TEMPERATURES AND SOME SHOWERS. TEMPERATURES WILL
BEGIN TO MODERATE BY THE WEEKEND AS LOW PRESSURE FINALLY MOVES
AWAY FROM THE AREA...ALTHOUGH A WEAK FRONT MAY PRODUCE A FEW
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
AT 00Z A SHARP UPPER LEVEL TROUGH AXIS EXTENDS SOUTHWARD ACROSS
EASTERN MICHIGAN...WITH AN ASSOCIATED COLD FRONTAL BOUNDARY JUST
EAST OF THIS ACROSS WESTERN LAKE ERIE. MEANWHILE...A LINE OF
SHOWERS AND THUNDERSTORMS HAS DEVELOPED WITH A PRE-FRONTAL
TROUGH...WITH THESE EXTENDING ROUGHLY FROM ROCHESTER TO SALAMANCA
EARLY THIS EVENING. THE SW FLOW AHEAD OF THE UPPER LEVEL TROUGH IS
NEARLY ALIGNED WITH THESE SHOWERS...RESULTING IN A SLOW EASTWARD
PROGRESSION. HEAVY RAIN IS THE MAIN THREAT WITH THIS...AS CELLS
STREAM ALONG THIS BOUNDARY. HOWEVER...WITH THE LOSS OF DAYTIME
HEATING AND ITS MOVEMENT INTO AN AREA WHICH DID NOT GET AS MUCH
SUNSHINE TODAY THESE SHOULD BECOME MORE ELEVATED AND/OR
STRATIFORM AS THE NIGHT GOES ON. THE HRRR HAS THIS FEATURE WELL
CAPTURED...AND SHOULD PROVIDE GOOD GUIDANCE IN ADDITION TO RADAR
TRENDS. BEHIND THIS...EXPECT A PERIOD OF MAINLY DRY WEATHER TO
DEVELOP ACROSS WESTERN NEW YORK FOR AT LEAST SEVERAL HOURS.
BEHIND THIS...THE COLD FRONT WILL CONTINUE TO MOVE EASTWARD...AND
ENTER WESTERN NEW YORK SHORTLY AFTER MIDNIGHT. THERE ARE SCATTERED
SHOWERS AND A FEW THUNDERSTORMS WITH THE COLD FRONT. MEANWHILE THE
APPROACHING UPPER AND MID LEVEL TROUGH AND ADDITIONAL VORTICITY
MAXIMA WILL ENTER THE REGION WITH AN INCREASING RISK OF SHOWERS
AGAIN. THERE WILL ALSO BE SOME LAKE ENHANCEMENT LATE TONIGHT AND
EARLY WEDNESDAY MORNING EAST OF LAKE ERIE AS LAKE INDUCED
EQUILIBRIUM LEVELS CLIMB TO AROUND 30K FEET...SUPPORTING SHOWERS
AND PERHAPS EVEN A THUNDERSTORM.
ON WEDNESDAY THE MORE PERSISTENT RAIN EAST OF LAKE ONTARIO WILL
END. SCATTERED SHOWERS ASSOCIATED WITH THE BASE OF THE MID LEVEL
TROUGH WILL CROSS THE REGION FROM WEST TO EAST DURING THE
MORNING...EXITING THE FAR WEST EARLY AND REACHING EAST OF LAKE
ONTARIO BY LATE MORNING OR MIDDAY. THERE MAY STILL BE SOME BRIEF
LAKE ENHANCEMENT FOR AN HOUR OR TWO EAST OF LAKES ERIE AND ONTARIO
NEAR THE TIME OF THE TROUGH PASSAGE. BY AFTERNOON EXPECT THE LAKE
PROCESS TO FLIP...WITH STABLE LAKE SHADOWS DEVELOPING WITH PEAK
HEATING. THIS WILL ALLOW A FEW DIURNALLY DRIVEN SHOWERS TO DEVELOP
INLAND FROM THE LAKES... MOST LIKELY ALONG A CONVERGENCE ZONE
FORECAST TO DEVELOP FROM THE NIAGARA FRONTIER TO THE NORTHERN
FINGER LAKES. EXPECT COVERAGE TO BE RELATIVELY SPARSE DURING THE
AFTERNOON.
HIGH TEMPERATURES ON WEDNESDAY WILL BE 5-8 DEGREES BELOW AVERAGE...
WITH LOW TO MID 70S AT LOWER ELEVATIONS AND UPPER 60S ACROSS HIGHER
TERRAIN.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
WE WILL BE UNDER THE INFLUENCE OF THE CLOSED UPPER LOW OVER SOUTHERN
QUEBEC THROUGH THE PERIOD. ALTHOUGH TOUGH TO PIN POINT BEST AREAS
FOR PRECIPITATION IN THIS PATTERN...THERE LOOKS TO BE AMPLE MOISTURE
AND SUFFICIENT COLD AIR ALOFT TO SUPPORT DIURNALLY DRIVEN
CONVECTION...ESPECIALLY ACROSS THE NORTH COUNTRY WHICH WILL BE
CLOSER TO THE UPPER LOW CENTER AND BETTER MOISTURE FIELD. WILD CARD
WITHIN THIS COLD CYCLONIC FLOW PATTERN WILL BE THE POTENTIAL FOR
LAKE INDUCED PRECIPITATION. ALTHOUGH THERE WILL BE SOME POTENTIAL
WEDNESDAY NIGHT/THURSDAY MORNING...THE GREATER LIKELIHOOD WILL BE
EAST/SOUTHEAST OF LAKE ONTARIO THURSDAY NIGHT INTO FRIDAY MORNING
WHEN THE COLDEST 850 MB AIR NEARING +4C SETTLES ACROSS THE REGION.
PERSISTENT DRY AIR CUTTING UNDERNEATH OF THE UPPER LOW WILL LIKELY
LIMIT THE ACTIVITY OFF LAKE ERIE.
TEMPERATURES THROUGH THE PERIOD SHOULD AVERAGE A SOLID 10 TO 15
DEGREES BELOW NORMAL WITH THURSDAY BEING THE COLDEST DAY WITH HIGHS
IN THE 60S...AND ONLY 50S OVER THE HIGHER TERRAIN.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MEDIUM RANGE MODELS SEEM TO BE A BIT MORE IN LINE WITH THE SHORTWAVE
ENERGY FORECAST TO DROP THROUGH THE GREAT LAKES REGION SATURDAY
NIGHT THROUGH SUNDAY. THIS GIVES A BIT MORE CONFIDENCE TO ADDING OR
INCREASING PRECIPITATION PROBABILITIES DURING THIS TIME FRAME.
CHANCES FOR ADDITIONAL SHOWERS PROBABLY STICKS AROUND SUNDAY NIGHT
BEFORE THE ATMOSPHERE DRIES SUFFICIENTLY. LOWER CONFIDENCE DEVELOPS
LATER IN THE PERIOD AS DIFFERENT DATA SETS SUGGESTING EITHER MID
LEVEL RIDGING...OR POSSIBLY MORE SHORTWAVE ENERGY MOVING INTO THE
REGION. CONTINUITY FORECAST WAS DRY AND WILL LEAVE IT THAT WAY AS
ECMWF SUGGESTS A DRIER SCENARIO.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
SHOWERS WITH A FEW EMBEDDED -TSRA WILL GRADUALLY MOVE EAST OF ROC
THIS EVENING...EVENTUALLY REACHING ART. THIS WILL CONTINUE TO
PRODUCE AREAS OF MVFR/IFR.
BEHIND THE AREA OF CONVECTION...A PERIOD OF IFR CIGS APPEARS LIKELY
AGAIN OVERNIGHT ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER AND
FINGER LAKES WITH MOIST LOW LEVEL UPSLOPE FLOW. BOUNDARY LAYER
MIXING AND CLOUD COVER SHOULD PREVENT MUCH IN THE WAY OF
FOG...ALTHOUGH A FEW HILLTOPS MAY GET INTO LOCAL FOG IF THE STRATUS
LAYER INTERSECTS THE TERRAIN.
ON WEDNESDAY THE LOW CIGS ACROSS THE HIGHER TERRAIN WILL IMPROVE TO
MVFR BY LATE MORNING WITH FURTHER IMPROVEMENT TO VFR BY AFTERNOON.
STEADIER RAIN EAST OF LAKE ONTARIO EARLY WITH LOCAL MVFR/IFR WILL
TAPER OFF. ANOTHER BROKEN BAND OF SHOWERS WILL MOVE INTO WESTERN NY
VERY EARLY WEDNESDAY MORNING THEN PROGRESS EAST ACROSS THE AREA
DURING THE DAY WITH A BRIEF PERIOD OF MVFR. SCATTERED SHOWERS AND
ISOLATED THUNDER WILL DEVELOP DURING THE AFTERNOON INLAND FROM THE
LAKES BUT COVERAGE SHOULD REMAIN RATHER SPARSE WITH VFR PREVAILING
IN MOST PLACES DURING THE AFTERNOON.
OUTLOOK...
THURSDAY NIGHT AND FRIDAY...VFR WITH A CHANCE OF MVFR IN SHOWERS
ESPECIALLY EAST OF THE LAKES.
SATURDAY...VFR.
SATURDAY NIGHT AND SUNDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
MODERATE SOUTHERLY WINDS AT THE EAST END OF LAKE ONTARIO HAVE
DIMINISHED SOME AND WILL CONTINUE TO DO SO LATE THIS EVENING.
WINDS WILL BECOME MORE WESTERLY AND INCREASE LATE TONIGHT AND
WEDNESDAY BEHIND A COLD FRONT AND PRODUCE ANOTHER PERIOD OF SMALL
CRAFT ADVISORY CONDITIONS ON BOTH LAKES ERIE AND ONTARIO. WINDS
AND WAVES WILL DIMINISH FROM WEST TO EAST LATER WEDNESDAY NIGHT AS
THE PRESSURE GRADIENT RELAXES. WINDS MAY INCREASE AGAIN DURING THE
DAY THURSDAY WITH COLD AIR ALOFT ALLOWING FOR STEEP LAPSE RATES
AND EFFICIENT MOMENTUM TRANSFER OF STRONGER WINDS TO THE SURFACE.
CONDITIONS WILL BECOME MARGINALLY SUPPORTIVE OF WATERSPOUTS
WEDNESDAY MORNING ON LAKE ERIE...AND MORNING THROUGH EARLY AFTERNOON
ON LAKE ONTARIO. A BETTER CHANCE OF WATERSPOUTS WILL OCCUR LATE
WEDNESDAY NIGHT THROUGH FRIDAY MORNING AS THE COOLEST AIR ALOFT
CROSSES THE LOWER LAKES. WATERSPOUTS ARE MOST COMMON IN AND NEAR
BANDS OF LAKE EFFECT CLOUDS AND SHOWERS WHERE LOW LEVEL CONVERGENCE
IS MAXIMIZED.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM WEDNESDAY TO 2 AM EDT THURSDAY
FOR LEZ040-041.
SMALL CRAFT ADVISORY FROM 10 AM TO 8 PM EDT WEDNESDAY FOR
LEZ020.
SMALL CRAFT ADVISORY FROM 5 AM WEDNESDAY TO 2 AM EDT
THURSDAY FOR LOZ042-043.
SMALL CRAFT ADVISORY FROM 10 AM WEDNESDAY TO 5 AM EDT
THURSDAY FOR LOZ044-045.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...APFFEL
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
810 PM EDT TUE AUG 12 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION OVERNIGHT WITH A PERIOD OF
SHOWERS AND THUNDERSTORMS. LOW PRESSURE WILL MOVE TO QUEBEC
TONIGHT THEN STALL THROUGH FRIDAY AND KEEP AN UNSETTLED PATTERN
ACROSS OUR REGION WITH COOL TEMPERATURES AND OCCASIONAL SHOWERS.
TEMPERATURES WILL BEGIN TO MODERATE BY THE WEEKEND AS LOW PRESSURE
FINALLY MOVES AWAY FROM THE AREA...ALTHOUGH A WEAK FRONT MAY
PRODUCE A FEW WIDELY SCATTERED SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
A SHARP UPPER LEVEL TROUGH AXIS EXTENDS SOUTHWARD ACROSS EASTERN
MICHIGAN EARLY THIS EVENING...WITH AN ASSOCIATED COLD FRONTAL
BOUNDARY WHICH IS MOVING ACROSS WESTERN LAKE ERIE AT 800 PM.
MEANWHILE...A LINE OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED
WITH A PRE-FRONTAL TROUGH...WITH THESE EXTENDING ROUGHLY FROM
ROCHESTER TO SALAMANCA EARLY THIS EVENING. THE APPROACHING UPPER
LEVEL TROUGH HAS BROUGHT WINDS MORE IN LINE WITH THIS
FEATURE...RESULTING IN A SLOW EASTWARD PROGRESSION. AT THIS
POINT...HEAVY RAIN IS THE MAIN THREAT WITH THIS...AS CELLS STREAM
ALONG THIS BOUNDARY. HOWEVER...IT IS MOVING INTO AN AREA WHICH DID
NOT GET AS MUCH DAYTIME HEATING...AND SHOULD BECOME MORE ELEVATED
AND/OR STRATIFORM AS THE NIGHT GOES ON. THE HRRR HAS THIS FEATURE
WELL CAPTURED...AND SHOULD PROVIDE GOOD GUIDANCE IN ADDITION TO
RADAR TRENDS.
OTHERWISE...THERE IS A LONE THUNDERSTORM BEHIND THIS...WITH
SCATTERED SHOWERS AND THUNDERSTORMS ALONG THE COLD FRONT. BEHIND
THE EVENING LINE OF CONVECTION...EXPECT A PERIOD OF MAINLY DRY
WEATHER TO DEVELOP ACROSS WESTERN NY FOR AT LEAST SEVERAL HOURS.
BY LATE TONIGHT THE BASE OF THE MID LEVEL TROUGH AND ADDITIONAL
VORTICITY MAXIMA WILL ENTER THE REGION WITH AN INCREASING RISK OF
SHOWERS AGAIN. THERE WILL ALSO BE SOME LAKE ENHANCEMENT LATE
TONIGHT AND EARLY WEDNESDAY MORNING EAST OF LAKE ERIE AS LAKE
INDUCED EQUILIBRIUM LEVELS CLIMB TO AROUND 30K FEET...SUPPORTING
SHOWERS AND PERHAPS EVEN A THUNDERSTORM.
ON WEDNESDAY THE MORE PERSISTENT RAIN EAST OF LAKE ONTARIO WILL
END. SCATTERED SHOWERS ASSOCIATED WITH THE BASE OF THE MID LEVEL
TROUGH WILL CROSS THE REGION FROM WEST TO EAST DURING THE
MORNING...EXITING THE FAR WEST EARLY AND REACHING EAST OF LAKE
ONTARIO BY LATE MORNING OR MIDDAY. THERE MAY STILL BE SOME BRIEF
LAKE ENHANCEMENT FOR AN HOUR OR TWO EAST OF LAKES ERIE AND ONTARIO
NEAR THE TIME OF THE TROUGH PASSAGE. BY AFTERNOON EXPECT THE LAKE
PROCESS TO FLIP...WITH STABLE LAKE SHADOWS DEVELOPING WITH PEAK
HEATING. THIS WILL ALLOW A FEW DIURNALLY DRIVEN SHOWERS TO DEVELOP
INLAND FROM THE LAKES... MOST LIKELY ALONG A CONVERGENCE ZONE
FORECAST TO DEVELOP FROM THE NIAGARA FRONTIER TO THE NORTHERN
FINGER LAKES. EXPECT COVERAGE TO BE RELATIVELY SPARSE DURING THE
AFTERNOON.
HIGH TEMPERATURES ON WEDNESDAY WILL BE 5-8 DEGREES BELOW AVERAGE...
WITH LOW TO MID 70S AT LOWER ELEVATIONS AND UPPER 60S ACROSS HIGHER
TERRAIN.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
WE WILL BE UNDER THE INFLUENCE OF THE CLOSED UPPER LOW OVER SOUTHERN
QUEBEC THROUGH THE PERIOD. ALTHOUGH TOUGH TO PIN POINT BEST AREAS
FOR PRECIPITATION IN THIS PATTERN...THERE LOOKS TO BE AMPLE MOISTURE
AND SUFFICIENT COLD AIR ALOFT TO SUPPORT DIURNALLY DRIVEN
CONVECTION...ESPECIALLY ACROSS THE NORTH COUNTRY WHICH WILL BE
CLOSER TO THE UPPER LOW CENTER AND BETTER MOISTURE FIELD. WILD CARD
WITHIN THIS COLD CYCLONIC FLOW PATTERN WILL BE THE POTENTIAL FOR
LAKE INDUCED PRECIPITATION. ALTHOUGH THERE WILL BE SOME POTENTIAL
WEDNESDAY NIGHT/THURSDAY MORNING...THE GREATER LIKELIHOOD WILL BE
EAST/SOUTHEAST OF LAKE ONTARIO THURSDAY NIGHT INTO FRIDAY MORNING
WHEN THE COLDEST 850 MB AIR NEARING +4C SETTLES ACROSS THE REGION.
PERSISTENT DRY AIR CUTTING UNDERNEATH OF THE UPPER LOW WILL LIKELY
LIMIT THE ACTIVITY OFF LAKE ERIE.
TEMPERATURES THROUGH THE PERIOD SHOULD AVERAGE A SOLID 10 TO 15
DEGREES BELOW NORMAL WITH THURSDAY BEING THE COLDEST DAY WITH HIGHS
IN THE 60S...AND ONLY 50S OVER THE HIGHER TERRAIN.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
MEDIUM RANGE MODELS SEEM TO BE A BIT MORE IN LINE WITH THE SHORTWAVE
ENERGY FORECAST TO DROP THROUGH THE GREAT LAKES REGION SATURDAY
NIGHT THROUGH SUNDAY. THIS GIVES A BIT MORE CONFIDENCE TO ADDING OR
INCREASING PRECIPITATION PROBABILITIES DURING THIS TIME FRAME.
CHANCES FOR ADDITIONAL SHOWERS PROBABLY STICKS AROUND SUNDAY NIGHT
BEFORE THE ATMOSPHERE DRIES SUFFICIENTLY. LOWER CONFIDENCE DEVELOPS
LATER IN THE PERIOD AS DIFFERENT DATA SETS SUGGESTING EITHER MID
LEVEL RIDGING...OR POSSIBLY MORE SHORTWAVE ENERGY MOVING INTO THE
REGION. CONTINUITY FORECAST WAS DRY AND WILL LEAVE IT THAT WAY AS
ECMWF SUGGESTS A DRIER SCENARIO.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
A BAND OF CONVECTION EXTENDING FROM ELZ-ROC WILL GRADUALLY WEAKEN
AS IT MOVES EAST THIS EVENING. THERE ARE SOME -TSRA WITH
THIS...BUT THESE SHOULD BE SCATTERED IN NATURE THIS EVENING AS THE
AREA BECOMES LESS CONVECTIVE. THIS WILL CONTINUE TO PRODUCE AREAS
OF MVFR/IFR FROM ROC-KART.
BEHIND THE AREA OF CONVECTION...A PERIOD OF IFR CIGS APPEARS LIKELY
AGAIN OVERNIGHT ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER AND
FINGER LAKES WITH MOIST LOW LEVEL UPSLOPE FLOW. BOUNDARY LAYER
MIXING AND CLOUD COVER SHOULD PREVENT MUCH IN THE WAY OF
FOG...ALTHOUGH A FEW HILLTOPS MAY GET INTO LOCAL FOG IF THE STRATUS
LAYER INTERSECTS THE TERRAIN.
ON WEDNESDAY THE LOW CIGS ACROSS THE HIGHER TERRAIN WILL IMPROVE TO
MVFR BY LATE MORNING WITH FURTHER IMPROVEMENT TO VFR BY AFTERNOON.
STEADIER RAIN EAST OF LAKE ONTARIO EARLY WITH LOCAL MVFR/IFR WILL
TAPER OFF. ANOTHER BROKEN BAND OF SHOWERS WILL MOVE INTO WESTERN NY
VERY EARLY WEDNESDAY MORNING THEN PROGRESS EAST ACROSS THE AREA
DURING THE DAY WITH A BRIEF PERIOD OF MVFR. SCATTERED SHOWERS AND
ISOLATED THUNDER WILL DEVELOP DURING THE AFTERNOON INLAND FROM THE
LAKES BUT COVERAGE SHOULD REMAIN RATHER SPARSE WITH VFR PREVAILING
IN MOST PLACES DURING THE AFTERNOON.
OUTLOOK...
THURSDAY NIGHT AND FRIDAY...VFR WITH A CHANCE OF MVFR IN SHOWERS
ESPECIALLY EAST OF THE LAKES.
SATURDAY...VFR.
SATURDAY NIGHT AND SUNDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
MODERATE SOUTHERLY WINDS AT THE EAST END OF LAKE ONTARIO HAVE
DIMINISHED SOME AND WILL CONTINUE TO DO SO LATE THIS EVENING.
WINDS WILL BECOME MORE WESTERLY AND INCREASE LATE TONIGHT AND
WEDNESDAY BEHIND A COLD FRONT AND PRODUCE ANOTHER PERIOD OF SMALL
CRAFT ADVISORY CONDITIONS ON BOTH LAKES ERIE AND ONTARIO. WINDS
AND WAVES WILL DIMINISH FROM WEST TO EAST LATER WEDNESDAY NIGHT AS
THE PRESSURE GRADIENT RELAXES. WINDS MAY INCREASE AGAIN DURING THE
DAY THURSDAY WITH COLD AIR ALOFT ALLOWING FOR STEEP LAPSE RATES
AND EFFICIENT MOMENTUM TRANSFER OF STRONGER WINDS TO THE SURFACE.
CONDITIONS WILL BECOME MARGINALLY SUPPORTIVE OF WATERSPOUTS
WEDNESDAY MORNING ON LAKE ERIE...AND MORNING THROUGH EARLY AFTERNOON
ON LAKE ONTARIO. A BETTER CHANCE OF WATERSPOUTS WILL OCCUR LATE
WEDNESDAY NIGHT THROUGH FRIDAY MORNING AS THE COOLEST AIR ALOFT
CROSSES THE LOWER LAKES. WATERSPOUTS ARE MOST COMMON IN AND NEAR
BANDS OF LAKE EFFECT CLOUDS AND SHOWERS WHERE LOW LEVEL CONVERGENCE
IS MAXIMIZED.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM WEDNESDAY TO 2 AM EDT THURSDAY
FOR LEZ040-041.
SMALL CRAFT ADVISORY FROM 10 AM TO 8 PM EDT WEDNESDAY FOR
LEZ020.
SMALL CRAFT ADVISORY FROM 5 AM WEDNESDAY TO 2 AM EDT
THURSDAY FOR LOZ042-043.
SMALL CRAFT ADVISORY FROM 10 AM WEDNESDAY TO 5 AM EDT
THURSDAY FOR LOZ044-045.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...APFFEL
MARINE...APFFEL/HITCHCOCK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
330 PM EDT MON AUG 11 2014
.SYNOPSIS...
A COASTAL LOW OFFSHORE OF SOUTH CAROLINA AND A STALLED FRONTAL
BOUNDARY WILL BOTH LIFT SLOWLY NORTH THROUGH TUESDAY. THIS WILL
BRING THE POTENTIAL FOR ADDITIONAL RAINFALL OVER ALREADY WET
GROUND. A STRONG COLD FRONT WILL CROSS THE AREA OVERNIGHT
WEDNESDAY...BRINGING DRIER CONDITIONS AND COOLER NIGHT-TIME
TEMPERATURES INTO LATE WEEK. SEASONABLE WEATHER IS EXPECTED THIS
WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 330 PM MONDAY...CANCELED THE FLOOD WATCH WITH THE LAST
FORECAST UPDATE. WIDESPREAD SHOWERS HAVE CERTAINLY POPPED UP...BUT
THEY HAVE REMAINED VERY SHALLOW/COMPLETELY CONFINED TO AREAS BELOW
THE FREEZING LEVEL. STRONG MID LEVEL NEGATIVE VORTICITY
ADVECTION/DOWNWARD VERTICAL MOTION LIKELY TO BLAME...AND THIS WILL
NOT CHANGE UNTIL THE VORT MIN CROSSES AT 00Z. THE SHALLOWNESS OF
THE STORMS HAS LEAD TO THEM BEING STEERED BY THE NEARLY
UNIDIRECTIONAL ONSHORE FLOW AND INDIVIDUAL ELEMENTS ARE SHOWING
MOTIONS OF 8-12KT. WITH SHALLOWER AND THUS LIGHTER SHOWER ACTIVITY
AND A HIGHER STORM MOTION THAN PREV EXPECTED THE THREAT FOR
WIDESPREAD FLOODING LIKELY WON`T MATERIALIZE. ITS STILL TOUGH TO
RULE OUT ONE PROBLEM SPOT OR TWO BUT THEY WOULD BE BETTER HANDLED
WITH SHORT-FUSED ADVISORIES OR WARNINGS. MODELS ARE STRUGGLING
WITH THE MESOSCALE DETAIL BUT THE RUC SEEMS TO BE SOMEWHAT WELL
INITIALIZED. IT FAVORS PRECIP JUST NORTH OF THE STATE LINE FOR THE
NEXT FEW HOURS...DRIFTING NORTH AND WEST. SATELLITE TRENDS SHOW A
POSSIBLE MINIMUM IN ACTIVITY ALONG THE GRAND STRAND WHERE CU
FIELDS ARE LEAST DEVELOPED BUT IT`LL BE TOUGH TO HAVE A POP OF
LESS THAN 20 FOR MOST OF THE AREA IN THE VERY NEAR TERM SINCE
DAYTIME HEATING IS THE SOLE FACTOR DRIVING DEVELOPMENT.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...ONE MORE DAY OF UNSETTLED WEATHER TUE SHOULD
GIVE WAY TO MID-LEVEL DRYING AND MORE SEASONABLE TEMPS ON WED. THE
PERIOD BEGINS WITH AN UPPER TROUGH OVER THE GREAT LAKES WHICH WILL
DIG AS IT MOVES EASTWARD THROUGH WED. MEANWHILE THE STALLED FRONT
THAT HAS PLAGUED OUR REGION FOR DAYS...AND ITS ASSOCIATED SFC
LOW...WILL FINALLY LIFT NORTHWARD AS A WARM FRONT DURING THE DAY
TUE. PWATS REMAIN AROUND 2.0 INCHES ON TUE...AND ENOUGH
INSTABILITY SHOULD EXIST FOR AT LEAST SCT CONVECTION DURING THE
DAY. GIVEN OUR LOCATION UNDER THE UPPER DIVERGENT REGION OF THE
TROUGH...ANY WEAK IMPULSES ALOFT WOULD FURTHER ENHANCE OUR PRECIP
CHANCES FOR TUE. POPS WILL RAPIDLY DIMINISH AS THE DAY PROGRESSES
ON WED AS A COLD FRONT MAKES IT WAY INTO OUR CWA. ONCE THE UPPER
TROUGH AXIS CLEARS OUR AREA BY MIDDAY...DRY WESTERLY FLOW ALOFT
WILL CAUSE PWATS TO PLUMMET AS LOW AS 1.0 INCH BY 00Z THU. THIS
WILL BRING US SOME WELCOMED RELIEF FROM THE PERSISTENT CLOUD COVER
AND RAIN WE HAVE DEALT WITH LATELY.
THE WARMER AIR BEHIND THE WARM FRONT WILL LIKELY BE OFFSET BY CLOUDS
AND PRECIP TOMORROW. THEREFORE...HAVE SIDED WITH THE COOLER NAM
GUIDANCE...WHICH YIELDS HIGHS IN THE MID TO UPPER 80S ON TUE.
OVERNIGHT LOWS ON TUE WILL RANGE FROM THE LOWER 70S INLAND TO MID
70S AT THE COAST. WED WILL FEATURE A RETURN TO MORE SEASONABLE HIGHS
AS SUNSHINE FINALLY RETURNS TO THE EASTERN CAROLINAS. DRY WESTERLY
FLOW SHOULD ALLOW HIGHS TO CLIMB TO AROUND 90 INLAND AND UPPER 80S
ALONG THE COAST. COOLER AIR WILL FILTER INTO OUR CWA BEHIND THE COLD
FRONT OVERNIGHT WED...WITH LOWS FALLING INTO THE MID TO UPPER 60S
EVERYWHERE AWAY FROM THE BEACHES.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 330 PM MONDAY...PERIOD BEGINS WITH COLD FRONT STALLED OFF THE
COAST. ALOFT A 5H CUTOFF SITS OVER SOUTHEAST CANADA WITH THE
ASSOCIATED MID LEVEL TROUGH EXTENDING SOUTH OVER THE EASTERN CONUS.
THIS SETUP SHOULD PRODUCE A PERIOD OF DRY WEATHER FOR THE CAROLINAS
WITH DEEP WESTERLY FLOW ENSURING MID LEVELS REMAIN DRY INTO THE
WEEKEND. THU WILL BE THE DRIEST DAY AND IS LIKELY TO BE A DAY
WITHOUT PRECIP. PRECIPITABLE WATER VALUES ARE DOWN AROUND AN INCH
FROM A COMBINATION OF DOWNSLOPE FLOW AND MID LEVEL SUBSIDENCE.
LOW LEVEL RETURN FLOW SETS UP FRI AS SURFACE HIGH MOVES FROM THE
WESTERN GREAT LAKES THU TO THE OH VALLEY FRI. MID LEVEL WESTERLY
FLOW CONTINUES BUT THE INCREASE IN LOW LEVEL MOISTURE DUE TO THE
RETURN FLOW WILL BRING ABOUT A SLIGHT INCREASE IN PRECIP CHANCES.
GIVEN THE AMOUNT OF DRY AIR IN THE MID LEVELS AND THE MARGINAL
THERMODYNAMIC PROFILES IN FORECAST SOUNDINGS DO NOT THINK MORE THAN
A SLIGHT CHC OR SILENT POP IS WARRANTED FRI.
CUTOFF LOW AND MID LEVEL TROUGH START TO LIFT NORTHEAST SAT WHILE AT
THE SURFACE LOW LEVEL RETURN FLOW INCREASES. IN THE WAKE OF THE 5H
TROUGH MID LEVEL PATTERN FLATTENS OUT WITH WEST TO SOUTHWEST FLOW
ALOFT. INCREASED MID LEVEL MOISTURE...ESPECIALLY SUN AND MON...AND A
LITTLE PVA AHEAD OF WEAK SHORTWAVES SHOULD LEAD TO AN INCREASE IN
PRECIP COVERAGE FOR THE END OF THE PERIOD. WILL HOLD ONTO SILENT POP
SAT GIVEN WEAK FORCING AND MARGINAL VERTICAL PROFILES BUT INCREASE
TO CHC POP FOR SUN AND MON.
TEMPERATURES THROUGH THE PERIOD WILL BE NEAR CLIMO WITH HIGHS IN THE
UPPER 80S TO AROUND 90 AND LOWS IN THE LOWER 70S. GUIDANCE CONTINUES
TO KEEP THE FRONT STALLED OFF THE COAST THROUGH THE PERIOD...BUT
WITH 12Z RUNS THE FRONT IS A LITTLE FARTHER SOUTH AND THE FRONTAL
WAVES ARE LESS DEFINED SO FORECAST CONFIDENCE IS INCREASING.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...SHOWERS ARE CONTINUING TO DEVELOP THIS AFTERNOON AND ARE
INCREASING IN COVERAGE. THERE HAS BEEN LITTLE IF ANY LIGHTNING AND
ANY THUNDERSTORMS THIS AFTERNOON ARE EXPECTED TO REMAIN ISOLATED.
MOST SHOWERS THE REMAINDER OF THE DAYLIGHT HOURS SHOULD BE LIGHT.
TERMINALS WILL BE PREDOMINATELY VFR...BUT WILL INCLUDE TEMPO GROUPS
FOR MVFR CIGS/VSBYS INLAND TAFS DUE TO THE SHOWER ACTIVITY. IFR
COULD OCCUR IF CELLS WITH THE HEAVIER RAINFALL MOVE DIRECTLY OVER
A TERMINAL. BUT DUE TO THE ISOLATED COVERAGE OF HEAVY SHOWERS FEEL
THE CHANCE OF IFR WILL BE LOW.
MODELS ALL AGREE THERE WILL BE A DECREASE IN SHOWER ACTIVITY THIS
EVENING AND OVERNIGHT. IFR CONDITIONS IN FOG WILL DEVELOP AT
KFLO/KLBT AFTER MIDNIGHT...WITH TEMPO LIFR POSSIBLE 09-12Z. THE
COASTAL TERMINALS SHOULD REMAIN MVFR OR GREATER. MVFR/VFR WILL
DEVELOP BY MID-MORNING TUESDAY.
EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHRA/TSRA ALONG WITH TEMPO
MVFR CONDITIONS THROUGH TUES. IMPROVING CONDITIONS WED AS A FRONT
MOVES OFFSHORE. VFR THURS THROUGH SAT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 PM MONDAY...ONSHORE FLOW TO CONTINUE THROUGH THE PERIOD.
FRONTAL BOUNDARY STALLED WELL SOUTH OF THE AREA WILL HAVE A FLAT
WAVE TRAVERSE THE REGION LATE IN THE PERIOD. THIS WILL LEAD TO A
GRADUAL DECREASE IN WIND SPEED AND ALSO SOME SLIGHT BACKING IN THE
WIND DIRECTION. HEADING IN TO THE OVERNIGHT THE WINDS ARE A LITTLE
STRONGER OVER NRN WATERS COMPARED TO SOUTHERN ZONES AND SO HAVE
ABOUT AN OVER ALL FOOT HIGHER WAVES. WITH THE SLACKING OF THE
WINDS EXPECTED NRN WATERS WILL SEE MORE OF A DECREASE IN WAVES AND
ALL ZONES SHOULD SETTLE IN TO THE 2 TO 3 FT RANGE...STILL HIGHEST
NORTH.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM MONDAY...THE STALLED FRONT TO OUR SOUTH WILL FINALLY
LIFT BACK NORTH AS A WARM FRONT ON TUE...AS WEST WINDS BECOME
SOUTHWEST AROUND 10 KT DURING THE DAY. SEAS WILL BE IN THE 2-3 FT
RANGE...BUILDING TO 3-4 FT OVERNIGHT AS THE GRADIENT TIGHTENS AND
SOUTHWEST WINDS STRENGTHEN TO AROUND 15 KT. 3 FT SEAS WILL PREVAIL
ON WEDNESDAY WITHIN W-SW FLOW AHEAD OF AN APPROACHING COLD FRONT.
THIS FRONT WILL REACH THE COASTAL WATERS OVERNIGHT WED. WINDS WILL
VEER TO THE NORTHWEST AND THEN NORTH BEHIND THE FRONT EARLY THU...
REMAINING AOB 10 KTS. THESE OFFSHORE WINDS WILL KNOCK DOWN SEAS TO
2-3 FT BY THE END OF THE PERIOD.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 330 PM MONDAY...NORTHEAST FLOW AROUND 10 KT AT THE START OF
THE PERIOD WILL WEAKEN THU AS GRADIENT RELAXES. WINDS WILL VEER TO
EASTERLY BY THU AFTERNOON AND SOUTHEAST THU NIGHT. WEAK GRADIENT
IN PLACE THROUGH THE END OF THE PERIOD WILL KEEP SOUTHERLY WINDS
10 KT OR LESS FRI AND SAT. ONSHORE FLOW WILL DEVELOP NEAR SHORE
EACH DAY WITH THE SEA BREEZE WITH WINDS A COUPLE KT STRONGER. SEAS
2 TO 3 FT AT THE START OF THE PERIOD DROP TO AROUND 2 FT THU
AFTERNOON AND REMAIN AROUND 2 FT THROUGH SAT.
&&
.TIDES/COASTAL FLOODING...
AS OF 330 PM MONDAY...STRONG ASTRONOMICAL TIDES WITH THIS WANING
FULL MOON CYCLE WILL REQUIRE ANOTHER COASTAL FLOOD ADVISORY WITH
THIS EVENINGS HIGH TIDE FOR ALL BEACHES AND THE LOWER CAPE FEAR
RIVER SIMILAR TO THE LAST 2 EVENINGS...BUT LIKELY A FEW INCHES
LOWER ON THE PEAK WATER LEVELS. ELEVATED LEVELS WILL BE OBSERVED
ALONG THE BANKS OF THE ICW AS WELL DURING HIGH TIDE. THE LOWER
CAPE FEAR RIVER WILL EXPERIENCE MINOR COASTAL FLOODING INCLUDING
LOCALIZED SPOTS IN DOWNTOWN WILMINGTON. PREDICTED TIDE LEVELS SHOW
WE MAY NOT NEED THE ADVISORY TUESDAY NIGHT FOR THE BEACHES...BUT
THE LOWER CAPE FEAR WILL NEED AN ADVISORY FOR A FEW DAYS OF THE
NIGHT- TIME HIGH TIDE CYCLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
SCZ054-056.
NC...COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 1 AM EDT
TUESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...MBB
SHORT TERM...BJR
LONG TERM...III
AVIATION...MBB/MRR
MARINE...III/MBB/BJR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
300 PM EDT MON AUG 11 2014
.SYNOPSIS...HIGH PRESSURE WILL GRADUALLY MOVE NORTHEAST AWAY FROM
THE REGION...AS A WARM FRONT SLOWLY MOVES NORTH OVER THE CAROLINAS
THROUGH THE DAY TUESDAY. A COLD FRONT FOLLOWS QUICKLY FROM THE
NORTHWEST TUESDAY NIGHT INTO WEDNESDAY. HIGH PRESSURE MOVES OVER
MOST OF THE REGION FROM THE WEST WEDNESDAY AND WEDNESDAY NIGHT WITH
DRIER AIR FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM MONDAY...
CERTAINLY A FAIR AMOUNT OF LOW-LEVEL DRYING TOOK PLACE IN CENTRAL
NORTH CAROLINA TODAY...ENOUGH TO RESULT IN AMPLE WARMING AND MORE OF
A CONVECTIVE APPEARANCE TO PRECIPITATION IN MOST PLACES AS OPPOSED
TO STRATIFORM...WITH THE POSSIBLE EXCEPTION OF THE IMMEDIATE TRIAD
TOWARD KINT. THERE WAS LIMITED LIGHTNING WITH THE CONVECTION...
OUTSIDE OF A STRIKE OR TWO SOUTH OF KLBT. SCATTERED-TO-NUMEROUS
SHOWERS WILL CONTINUE FOR THE LATE AFTERNOON INTO THE EVENING...
WITH ENOUGH INSTABILITY MAINLY SOUTH OF U.S. 64...WHERE THE SPC
MESOANALYSIS NOTES AROUND 500J/KG...TO PROVIDE FOR A CHANCE OF A
THUNDERSTORM. DURING THE EVENING HOURS...INCREASING STABILITY TAKING
PLACE DIURNALLY ALONG WITH THE BETTER MOISTURE AXIS BEING LOCATED
CLOSER TO THE NORTHWEST PIEDMONT WILL RESULT IN HIGHER CHANCES OF
SHOWERS IN THE WESTERN PIEDMONT AND ESPECIALLY TOWARD THE IMMEDIATE
TRIAD BY THE OVERNIGHT HOURS. EAST OF U.S. 1 LATE TONIGHT...WHILE
RETAINING A SMALL CHANCE FOR PRECIPITATION...MUCH OF THE GUIDANCE
INCLUDING THE HRRR WRF SUGGESTS LITTLE TAKING PLACE. CLOUDS SHOULD
LOWER AND THE OVERALL AIR MASS MOISTEN OVERNIGHT AS THE SURFACE HIGH
STARTS TO RETREAT AND THE SURFACE FRONT TO OUR SOUTH MOVES NORTH.
OVERNIGHT LOWS AROUND 70.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 300 PM MONDAY...
AS THE SURFACE HIGH CONTINUES TO RETREAT AND SURFACE LOW PRESSURE
MOVES NORTH ALONG THE COAST...THE SURFACE WARM FRONT SHOULD SLOWLY
MOVE NORTH. THE NAM IS FARTHER EAST WITH THE SURFACE LOW COMPARED TO
THE GFS...WHICH BRINGS WEAK SURFACE LOW PRESSURE RIGHT THROUGH
CENTRAL NORTH CAROLINA. THE GFS PATTERN IS SOMEWHAT CONCERNING...
WITH LOW LCL HEIGHTS ANTICIPATED ALONG WITH MODEST INSTABILITY BY
AFTERNOON...1000J/KG FROM THE 0-1KM LEVEL. HOWEVER...ITS 0-3KM
HELICITY FORECAST IS UNDER 100M2/S2 WITH ONLY MODEST 1000-500MB
LAPSE RATES AROUND 6C/KM AND 0-3KM SHEAR IS IN THE TEENS KNOTS AT
BEST. AFTER ANY MORNING LOW CLOUDS SHOULD START TO LIFT...BUFR
SOUNDINGS SHOW ENOUGH INSTABILITY FOR CU AND GENERALLY SKINNY CAPE
FOR SCATTERED SHOWERS AND THUNDERSTORMS. AS THE WARM FRONT IS
LOCATED BY THE GFS AND THE NAM MAINLY NORTH OF U.S. 64 BY
AFTERNOON...THE FORECAST LIFT OF THE NAM AND THE GFS IS HIGHEST FROM
THE TRIANGLE NORTH AND NORTHEAST. SHOULD THERE BE A STRONG
THUNDERSTORM...IT MAY BE THERE WHERE THE POTENTIAL IS HIGHEST.
DAYTIME HIGHS TUESDAY ARE ANOTHER CHALLENGE DEPENDING ON THE DEGREE
OF CLOUD COVER AND ESPECIALLY CU IN THE AFTERNOON...BUT WILL LEAN
TOWARD THE WARMER MAV GUIDANCE THOUGH NOT GOING QUITE THAT HIGH...
HIGHS 80 TO 85 IN THE TRIAD AND MID TO UPPER 80S ELSEWHERE.
TUESDAY NIGHT THE COLD FRONT STARTS TO MOVE INTO CENTRAL NORTH
CAROLINA FROM THE NORTHWEST. BUFR SOUNDINGS FROM BOTH THE NAM AND
THE GFS ACTUALLY FORECAST BRIEF LAYER WARMING BETWEEN 700MB AND
500MB BEFORE THE NAM IN PARTICULAR FORECASTS BRIEF COOLING IN THAT
LAYER ALONG AND AHEAD OF THE COLD FRONT. USING K INDICES AS A PROXY
FOR THE ACTUAL FRONT...AS THOSE VALUES GO QUICKLY NEGATIVE BEHIND
THE FRONT...THE FRONT SHOULD MOVE THROUGH THE TRIAD AROUND 06Z
WEDNESDAY AND THROUGH THE TRIANGLE AND JUST EAST OF U.S. 1 BY 12Z.
WILL RETAIN SOME CHANCES FOR PRECIPITATION UNTIL FRONTAL PASSAGE.
OVERNIGHT LOWS IN THE MID 60S IN THE TRIAD AND WITHIN A DEGREE OR
THREE OF 70 ELSEWHERE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
A TRANQUIL WEATHER PATTERN EXPECTED IN THE LONG TERM. TEMPERATURES
WILL REMAIN NEAR OR BELOW NORMAL.
A L/W TROUGH ANCHORED BY AN UPPER LEVEL LOW OVER ONTARIO/QUEBEC WILL
EXTEND SOUTHWARD INTO THE CAROLINAS THROUGH FRIDAY. THE LEAD COLD
FRONT ASSOCIATED WITH THE TROUGH WILL EXIT OUR COASTAL PLAIN
COUNTIES WEDNESDAY MORNING. MODEL TREND HAS LEANED TOWARD A SLIGHTLY
FASTER EAST PROGRESSION. THUS HAVE TRIMMED THE BACKSIDE OF THE
SLIGHT POPS...KEEPING THE 20 PERCENT POPS CONFINED TO LOCATIONS
ALONG AND EAST OF I-95 AT 6 AM...WITH NEGLIGIBLE POPS BY 10 AM.
WESTERLY LOW LEVEL FLOW IN THE WAKE OF THE FRONT WILL AID TO
DIMINISH/DISSIPATE CLOUD COVERAGE IN THE MORNING...LEADING TO MOSTLY
SUNNY SKIES AREAWIDE BY EARLY AFTERNOON. IT SHOULD BE NOTICEABLY
LESS HUMID ACROSS MICH OF THE PIEDMONT BY EARLY-MID AFTERNOON...AND
INTO THE SANDHILLS AND COASTAL PLAIN LATE IN THE DAY. INITIAL SURGE
OF LOW LEVEL CAA WILL BE NEGATED SOMEWHAT BY DOWNSLOPE COMPONENT OF
LOW LEVEL FLOW AND MID-AUGUST SUN. MAX TEMPS IN THE MID 80S NW TO
UPPER 80S/AROUND 90 SE.
SOME DOUBT AS TO WHETHER NEAR SURFACE WINDS WILL BE ABLE TO DECOUPLE
AS A SECONDARY SFC FRONT WILL APPROACH FROM THE W-NW LATE WEDNESDAY
NIGHT-EARLY THURSDAY. IF ATMOSPHERE REMAINS WELL MIXED...MOST PLACES
SHOULD SEE MIN TEMPS NO LOWER THAN 60-65 DEGREES (NW-SE). IF WINDS
DECOUPLE...NORMALLY COLDER LOCATIONS MY DIP BELOW 60.
A CANADIAN HIGH PRESSURE SYSTEM AT THE SURFACE WILL BE CENTERED OVER
THE LOWER OH VALLEY AND TN VALLEY THURSDAY AND FRIDAY. THIS WEATHER
SYSTEM WILL MAINTAIN DRY CONDITIONS WITH TEMPS GENERALLY A FEW
DEGREES SHY OF NORMAL. THICKNESSES SUPPORT MAX TEMPS IN THE LOW-MID
80S THURSDAY...AND SOLIDLY IN THE MID 80S FRIDAY. BETTER CHANCE FOR
THE NEAR SURFACE WINDS TO DECOUPLE THURSDAY NIGHT. IF SKIES REMAIN
CLEAR...SHOULD SEE MIN TEMPS IN THE UPPER 50S-LOWER 60S. AIR MASS
MODIFICATION FRIDAY NIGHT SUGGEST MIN TEMPS IN THE LOW-MID 60S.
SURFACE HIGH PRESSURE WILL SETTLE OVERHEAD SATURDAY THEN SLOWLY
WEAKEN AS L/W TROUGH WEAKENS AND LIFTS NWD. THIS WILL ALLOW A WEAK
RETURN OF LOW LEVEL MOISTURE BY LATE SATURDAY AND MORE SO SUNDAY
INTO MONDAY. THIS WILL LEAD TO MIXTURE OF SUN/CLOUDS BUT ANY
CONVECTIVE ACTIVITY WILL BE ISOLATED AND CONFINED TO NEAR THE
SEABREEZE...AND EXITING OFF THE HIGHER TERRAIN OF WESTERN NC.
THREAT APPEARS TOO LOW TO MENTION A SLIGHT CHANCE POP ON SUNDAY BUT
ENOUGH MOISTURE/DESTABILIZATION SHOULD EXISTS BY MONDAY FOR SLIGHT
CHANCE IN VICINITY OF THE OUR SOUTHERN AND WESTERN COUNTIES.
AIR MASS WILL CONTINUE TO MODIFY WITH TEMPS RETURNING TO NEAR NORMAL
LEVELS SATURDAY THROUGH MONDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 155 PM MONDAY...
MOSTLY VFR CONDITIONS WILL OCCUR FOR THE REST OF THE AFTERNOON WITH
SCATTERED MVFR CONDITIONS IN SHOWERS...OR LOWER CLOUDS ESPECIALLY
TOWARD THE TRIAD. AN ISOLATED THUNDERSTORM IS POSSIBLE ESPECIALLY
TOWARD KFAY. OVERNIGHT...AS HIGH PRESSURE RETREATS TO THE NORTHEAST
AND A WARM FRONT STARTS TO LIFT NORTH...CEILINGS ARE ONCE AGAIN
EXPECTED TO LOWER. BY LATE TONIGHT...MANY LOCATIONS SHOULD HAVE AT
LEAST MVFR CEILINGS AND VISIBILITIES...IF NOT IFR CEILINGS. FOR THE
OVERNIGHT HOURS...THE BETTER CHANCE OF ANY PRECIPITATION SHOULD BE
TOWARD THE TRIAD AND PARTICULARLY KINT. AVIATION CONDITIONS SHOULD
LIFT THROUGH MVFR WITH VFR CONDITIONS ANTICIPATED BY THE END OF THE
18Z VALID TAF PERIOD.
TUESDAY AFTERNOON AND TUESDAY NIGHT...EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS IN CENTRAL NORTH CAROLINA AHEAD OF A COLD FRONT THAT
SHOULD MOVE INTO CENTRAL NORTH CAROLINA OVERNIGHT TUESDAY. THE COLD
FRONT SHOULD BE MOVING THROUGH THE TRIAD AROUND 06Z WEDNESDAY AND
THROUGH THE TRIANGLE AROUND 12Z...PUSHING THROUGH THE COASTAL PLAIN
EARLY WEDNESDAY MORNING. THE PASSAGE OF THIS FRONT SHOULD END THE
HIGHER PROBABILITY OF SUB-VFR CONDITIONS FOR THE REST OF THE WORK
WEEK AND INTO SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...WSS
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
156 PM EDT MON AUG 11 2014
.SYNOPSIS...HIGH PRESSURE WILL GRADUALLY MOVE NORTHEAST AWAY FROM
THE REGION...AS A WARM FRONT SLOWLY MOVES NORTH OVER THE CAROLINAS
THROUGH THE DAY TUESDAY. A COLD FRONT FOLLOWS QUICKLY FROM THE
NORTHWEST TUESDAY NIGHT INTO WEDNESDAY. HIGH PRESSURE MOVES OVER
MOST OF THE REGION FROM THE WEST WEDNESDAY AND WEDNESDAY NIGHT WITH
DRIER AIR FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1125 AM MONDAY...
THE LATEST VISIBLE IMAGERY SHOWS SOME GOOD LOW-LEVEL DRY AIR HAVING
WORKED ITS WAY ACROSS A LARGE SEGMENT OF CENTRAL NORTH CAROLINA
ESPECIALLY ALONG AND EAST OF ABOUT U.S. 1. PRECIPITATION HAS HAD A
HARD TIME MOVING EAST...AND TEMPERATURES HAVE WARMED NICELY TOWARD
KCTZ. THE RAP SEEMS TO HAVE BEEN TOO AGGRESSIVE IN MOVING THE 850MB
MOISTURE EAST AND IF THE LATEST RAP TRENDS AND VISIBLE IMAGES
CONTINUE...PEEKS OF SUN WILL BE PRESENT AT TIMES AT LEAST AS FAR
WEST AS U.S. 1. RADAR TRENDS ALSO SHOW DEEP CONVECTION DEVELOPING
ALONG THE NORTH CAROLINA SEA BREEZE SO STILL EXPECT SHOWERS TO
DEVELOP DURING THE AFTERNOON POSSIBLY MORE INSTABILITY DRIVEN AND
MOVING THEN TOWARD THE NORTHWEST IN THE LOW-LEVEL FLOW. HIGHEST
CHANCES FOR PRECIPITATION IN THE IMMEDIATE TRIAD.
TEMPERATURES REMAIN A CHALLENGE BUT THE LATEST FORECAST STILL SEEMS
TO HAVE A GOOD...BASIC HANDLE ON EXPECTED MAXIMUMS IN GENERAL.
RAISED MAXES TOWARD KCTZ AND NUDGED JUST SLIGHTLY LOWER TOWARD
KEXX...BUT LEFT THE REST INTACT FOR NOW ALTHOUGH MORE THIN SPOTS
COULD PROVIDE FOR WARMER READINGS SUCH AS TOWARD KFAY. LOWS TONIGHT
IN THE UPPER 60S AND LOWER 70S WITH RELATIVELY HIGHER CHANCES FOR
PRECIPITATION IN THE NORTHWEST PIEDMONT OVERNIGHT...LESSER TOWARD
INTERSTATE 95.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE SURFACE HIGH AIDING THE COLD AIR DAMMING AIRMASS OVER THE AREA
WILL RETREAT BY TUESDAY MORNING...AND A SOUTHWESTERLY WIND WILL
DEVELOP AHEAD OF A SHORTWAVE CROSSING THE MIDWEST AND THE ATTENDANT
COLD FRONT APPROACHING FROM THE WEST. WEAK HEIGHT FALLS AND
INCREASINGLY CONFLUENT FLOW OUT AHEAD FO THE FRONT WILL SUPPORT
SCATTERED SHOWERS AND STORMS AS PW INCREASES BACK TOWARD 2 INCHES.
DEEP LAYER SHEAR...WHILE NOT OVERLY IMPRESSIVE...IS FORECAST TO
INCREASE TOWARD 30KT AS A JET STRENGTHENS ALONG THE APPALACHIANS OUT
AHEAD OF THE UPPER TROUGH AXIS. THIS BIGGEST QUESTION WILL BE HOW
MUCH INSTABILITY DEVELOPS DUE TO WEAK LAPSE RATES AND LINGERING
STRATUS IN THE MORNING. NOT ...SREF PROBABILITIES OF MLCAPE
EXCEEDING 1000 J/KG ARE GREATEST OVER THE COASTAL PLAIN WHERE
HEATING WILL BE STRONGEST....WHICH IS DISPLACED FROM THE STRONGEST
SHEAR. THUS...WHILE CONVECTION WILL BE MORE PREVALENT THAT IT HAS
BEEN IN THE PAST FEW DAYS...THE POTENTIAL FOR SEVRE WEATHER APPEARS
LIMITED. WILL RAISE TEMPS A BIT OVER THE SOUTHEAST AND EAST WHERE
FULL HEATING SHOULD BE REALIZED (IF NOT EVERYWHERE)...WITH HIGHS
RANGING FROM THE LOWER 80S NORTHWEST TO UPPER 80S SOUTHEAST.
DRIER AIR WILL BEGIN TO FILTER IN LATE TUESDAY NIGHT...ESPECIALLY
INT HE MID-LEVELS.. AS A NORTHWEST WIND DEVELOPS BEHIND THE COLD
FRONT. WILL MAINTAIN A SLIGHT CHANCE TO CHANCER POP OVER THE EAST
OVERNIGHT WITH LOWS IN THE MID 60S TO AROUND 70.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...
DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE GUIDANCE ARE IN
RELATIVELY GOOD AGREEMENT THIS MORNING...WHOSE SOLUTIONS ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING UPPER
LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS DURING DAYS 3-7.
A PRIMARY SFC COLD FRONT...ONE ACCOMPANYING A LEAD SHORTWAVE TROUGH
FORECAST TO AMPLIFY FROM THE NORTHERN PLAINS THIS MORNING TO THE
MIDDLE ATLANTIC COAST BY EARLY WED...WILL BE NEARING THE NC COAST
WED MORNING...WHILE A SECONDARY ONE IS FORECAST TO SETTLE SSE ACROSS
CENTRAL NC WED EVE-NIGHT. DRIER AND MORE STABLE AIR AT THE SFC AND
ALOFT...THE FORMER EXACERBATED BY 10-15 KTS OF WNW DOWNSLOPE H85
FLOW...WILL RESULT IN DRY; WARM; AND NOTICEABLY BREEZY CONDITIONS
WED...WITH THE MORE APPRECIABLE LOW LEVEL CAA TRAILING THE SECONDARY
FRONT WED NIGHT. HIGHS GENERALLY IN THE MIDDLE TO UPPER 80S...WITH
GENERALLY WESTERLY WINDS OF 10-15 MPH GUSTING TO AROUND 20 MPH.
FOLLOWING CANADIAN HIGH PRESSURE AND ASSOCIATED LOW LEVEL
THICKNESSES WED NIGHT WILL BE SUPPORTIVE OF LOWS MOSTLY IN THE UPPER
50S TO LOWER 60S...WITH FURTHER COOLING POTENTIAL INTO THE LOW-MID
50S WHERE/IF DECOUPLING (SFC CALM) OCCURS...MOST LIKELY IN SHELTERED
WESTERN PIEDMONT LOCATIONS.
THU THROUGH SUN: THE LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE
MID MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A
REINFORCING COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS
THE OH AND TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC
TROUGHING IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW
ALOFT AND ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE
CENTER OF THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH THE WEEKEND. MOISTURE...AT THE SFC AND THROUGH
A DEEP LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE
DRYNESS WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND
PRECIPITABLE WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY
SLOWLY INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-
INDUCED CONVECTION...THROUGH THE WKND. H85 TEMPS IN THE 14-16C
RANGE...SHOULD SUPPORT TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW
NORMAL...COOLEST MID-LATE WEEK.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 155 PM MONDAY...
MOSTLY VFR CONDITIONS WILL OCCUR FOR THE REST OF THE AFTERNOON WITH
SCATTERED MVFR CONDITIONS IN SHOWERS...OR LOWER CLOUDS ESPECIALLY
TOWARD THE TRIAD. AN ISOLATED THUNDERSTORM IS POSSIBLE ESPECIALLY
TOWARD KFAY. OVERNIGHT...AS HIGH PRESSURE RETREATS TO THE NORTHEAST
AND A WARM FRONT STARTS TO LIFT NORTH...CEILINGS ARE ONCE AGAIN
EXPECTED TO LOWER. BY LATE TONIGHT...MANY LOCATIONS SHOULD HAVE AT
LEAST MVFR CEILINGS AND VISIBILITIES...IF NOT IFR CEILINGS. FOR THE
OVERNIGHT HOURS...THE BETTER CHANCE OF ANY PRECIPITATION SHOULD BE
TOWARD THE TRIAD AND PARTICULARLY KINT. AVIATION CONDITIONS SHOULD
LIFT THROUGH MVFR WITH VFR CONDITIONS ANTICIPATED BY THE END OF THE
18Z VALID TAF PERIOD.
TUESDAY AFTERNOON AND TUESDAY NIGHT...EXPECT SCATTERED SHOWERS AND
THUNDERSTORMS IN CENTRAL NORTH CAROLINA AHEAD OF A COLD FRONT THAT
SHOULD MOVE INTO CENTRAL NORTH CAROLINA OVERNIGHT TUESDAY. THE COLD
FRONT SHOULD BE MOVING THROUGH THE TRIAD AROUND 06Z WEDNESDAY AND
THROUGH THE TRIANGLE AROUND 12Z...PUSHING THROUGH THE COASTAL PLAIN
EARLY WEDNESDAY MORNING. THE PASSAGE OF THIS FRONT SHOULD END THE
HIGHER PROBABILITY OF SUB-VFR CONDITIONS FOR THE REST OF THE WORK
WEEK AND INTO SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF/BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1125 AM EDT MON AUG 11 2014
.SYNOPSIS...A RIDGE OF HIGH PRESSURE EXTENDING INTO CENTRAL NC FROM
THE NORTHEAST TODAY WILL WEAKEN TONIGHT...ALLOWING A STATIONARY FRONT
OVER SOUTH CAROLINA TO SLOWLY LIFT NORTH AS A WARM FRONT ON TUESDAY.
A COLD FRONT WILL THEN MOVE INTO THE AREA FROM THE NORTHWEST ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1125 AM MONDAY...
THE LATEST VISIBLE IMAGERY SHOWS SOME GOOD LOW-LEVEL DRY AIR HAVING
WORKED ITS WAY ACROSS A LARGE SEGMENT OF CENTRAL NORTH CAROLINA
ESPECIALLY ALONG AND EAST OF ABOUT U.S. 1. PRECIPITATION HAS HAD A
HARD TIME MOVING EAST...AND TEMPERATURES HAVE WARMED NICELY TOWARD
KCTZ. THE RAP SEEMS TO HAVE BEEN TOO AGGRESSIVE IN MOVING THE 850MB
MOISTURE EAST AND IF THE LATEST RAP TRENDS AND VISIBLE IMAGES
CONTINUE...PEEKS OF SUN WILL BE PRESENT AT TIMES AT LEAST AS FAR
WEST AS U.S. 1. RADAR TRENDS ALSO SHOW DEEP CONVECTION DEVELOPING
ALONG THE NORTH CAROLINA SEA BREEZE SO STILL EXPECT SHOWERS TO
DEVELOP DURING THE AFTERNOON POSSIBLY MORE INSTABILITY DRIVEN AND
MOVING THEN TOWARD THE NORTHWEST IN THE LOW-LEVEL FLOW. HIGHEST
CHANCES FOR PRECIPITATION IN THE IMMEDIATE TRIAD.
TEMPERATURES REMAIN A CHALLENGE BUT THE LATEST FORECAST STILL SEEMS
TO HAVE A GOOD...BASIC HANDLE ON EXPECTED MAXIMUMS IN GENERAL.
RAISED MAXES TOWARD KCTZ AND NUDGED JUST SLIGHTLY LOWER TOWARD
KEXX...BUT LEFT THE REST INTACT FOR NOW ALTHOUGH MORE THIN SPOTS
COULD PROVIDE FOR WARMER READINGS SUCH AS TOWARD KFAY. LOWS TONIGHT
IN THE UPPER 60S AND LOWER 70S WITH RELATIVELY HIGHER CHANCES FOR
PRECIPITATION IN THE NORTHWEST PIEDMONT OVERNIGHT...LESSER TOWARD
INTERSTATE 95.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE SURFACE HIGH AIDING THE COLD AIR DAMMING AIRMASS OVER THE AREA
WILL RETREAT BY TUESDAY MORNING...AND A SOUTHWESTERLY WIND WILL
DEVELOP AHEAD OF A SHORTWAVE CROSSING THE MIDWEST AND THE ATTENDANT
COLD FRONT APPROACHING FROM THE WEST. WEAK HEIGHT FALLS AND
INCREASINGLY CONFLUENT FLOW OUT AHEAD FO THE FRONT WILL SUPPORT
SCATTERED SHOWERS AND STORMS AS PW INCREASES BACK TOWARD 2 INCHES.
DEEP LAYER SHEAR...WHILE NOT OVERLY IMPRESSIVE...IS FORECAST TO
INCREASE TOWARD 30KT AS A JET STRENGTHENS ALONG THE APPALACHIANS OUT
AHEAD OF THE UPPER TROUGH AXIS. THIS BIGGEST QUESTION WILL BE HOW
MUCH INSTABILITY DEVELOPS DUE TO WEAK LAPSE RATES AND LINGERING
STRATUS IN THE MORNING. NOT ...SREF PROBABILITIES OF MLCAPE
EXCEEDING 1000 J/KG ARE GREATEST OVER THE COASTAL PLAIN WHERE
HEATING WILL BE STRONGEST....WHICH IS DISPLACED FROM THE STRONGEST
SHEAR. THUS...WHILE CONVECTION WILL BE MORE PREVALENT THAT IT HAS
BEEN IN THE PAST FEW DAYS...THE POTENTIAL FOR SEVRE WEATHER APPEARS
LIMITED. WILL RAISE TEMPS A BIT OVER THE SOUTHEAST AND EAST WHERE
FULL HEATING SHOULD BE REALIZED (IF NOT EVERYWHERE)...WITH HIGHS
RANGING FROM THE LOWER 80S NORTHWEST TO UPPER 80S SOUTHEAST.
DRIER AIR WILL BEGIN TO FILTER IN LATE TUESDAY NIGHT...ESPECIALLY
INT HE MID-LEVELS.. AS A NORTHWEST WIND DEVELOPS BEHIND THE COLD
FRONT. WILL MAINTAIN A SLIGHT CHANCE TO CHANCER POP OVER THE EAST
OVERNIGHT WITH LOWS IN THE MID 60S TO AROUND 70.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...
DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE GUIDANCE ARE IN
RELATIVELY GOOD AGREEMENT THIS MORNING...WHOSE SOLUTIONS ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING UPPER
LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS DURING DAYS 3-7.
A PRIMARY SFC COLD FRONT...ONE ACCOMPANYING A LEAD SHORTWAVE TROUGH
FORECAST TO AMPLIFY FROM THE NORTHERN PLAINS THIS MORNING TO THE
MIDDLE ATLANTIC COAST BY EARLY WED...WILL BE NEARING THE NC COAST
WED MORNING...WHILE A SECONDARY ONE IS FORECAST TO SETTLE SSE ACROSS
CENTRAL NC WED EVE-NIGHT. DRIER AND MORE STABLE AIR AT THE SFC AND
ALOFT...THE FORMER EXACERBATED BY 10-15 KTS OF WNW DOWNSLOPE H85
FLOW...WILL RESULT IN DRY; WARM; AND NOTICEABLY BREEZY CONDITIONS
WED...WITH THE MORE APPRECIABLE LOW LEVEL CAA TRAILING THE SECONDARY
FRONT WED NIGHT. HIGHS GENERALLY IN THE MIDDLE TO UPPER 80S...WITH
GENERALLY WESTERLY WINDS OF 10-15 MPH GUSTING TO AROUND 20 MPH.
FOLLOWING CANADIAN HIGH PRESSURE AND ASSOCIATED LOW LEVEL
THICKNESSES WED NIGHT WILL BE SUPPORTIVE OF LOWS MOSTLY IN THE UPPER
50S TO LOWER 60S...WITH FURTHER COOLING POTENTIAL INTO THE LOW-MID
50S WHERE/IF DECOUPLING (SFC CALM) OCCURS...MOST LIKELY IN SHELTERED
WESTERN PIEDMONT LOCATIONS.
THU THROUGH SUN: THE LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE
MID MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A
REINFORCING COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS
THE OH AND TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC
TROUGHING IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW
ALOFT AND ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE
CENTER OF THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH THE WEEKEND. MOISTURE...AT THE SFC AND THROUGH
A DEEP LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE
DRYNESS WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND
PRECIPITABLE WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY
SLOWLY INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-
INDUCED CONVECTION...THROUGH THE WKND. H85 TEMPS IN THE 14-16C
RANGE...SHOULD SUPPORT TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW
NORMAL...COOLEST MID-LATE WEEK.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AS OF 1125 AM MONDAY...
CLOUDS HAVE BEEN STRUGGLING TO LOWER EVEN IN THE TRIAD THIS MORNING
AS THE RAP SEEMS TO BE OVERDOING THE AMOUNT OF LOW-LEVEL REALLY
MOIST AIR. HIGHEST POTENTIAL FOR CONDITIONS THROUGH MUCH OF THE
AFTERNOON IS FOR VFR CONDITIONS WITH SCATTERED LOWER CLOUDS IN MVFR.
THE BETTER CHANCES FOR A PERIOD OF IFR CONDITIONS REMAINS TOWARD THE
TRIAD AND PARTICULARLY TOWARD KINT IN THE MORE MOIST AND MODESTLY
UPSLOPE FLOW. OUTSIDE OF THE IMMEDIATE TRIAD...SHOWERS SHOULD BECOME
SCATTERED-TO-NUMEROUS LATER THIS AFTERNOON WITH A THUNDERSTORM
POSSIBLE ESPECIALLY TOWARD KFAY. SUB-VFR CEILINGS ARE THEN LIKELY TO
RETURN TONIGHT.
OUTLOOK...LOW CEILINGS SHOULD HANG AROUND EARLY TUESDAY AND THEN
SCATTER AND LIGHT AS A SOUTHWESTERLY WIND DEVELOPS ON TUESDAY AHEAD
OF AN APPROACHING COLD FRONT. A FEW SHOWERS AND STORMS WILL BE
POSSIBLE TUESDAY AFTERNOON...WITH DRIER CONDITIONS EXPECTED BEHIND
THE FRONT ONCE IT CROSSES THE AREA ON WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...DJF/BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...DJF/BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
950 AM EDT MON AUG 11 2014
.SYNOPSIS...A RIDGE OF HIGH PRESSURE EXTENDING INTO CENTRAL NC FROM
THE NORTHEAST TODAY WILL WEAKEN TONIGHT...ALLOWING A STATIONARY FRONT
OVER SOUTH CAROLINA TO SLOWLY LIFT NORTH AS A WARM FRONT ON TUESDAY.
A COLD FRONT WILL THEN MOVE INTO THE AREA FROM THE NORTHWEST ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM MONDAY...
THE LATEST SURFACE ANALYSIS SHOWED HIGH PRESSURE CONTINUING TO
EXTEND SOUTH ACROSS THE CAROLINAS...WITH LIMITED PRESSURE RISES THIS
MORNING ALTHOUGH WITH A WEAK TROUGH NOTED IN THE HIGH OVER THE
WESTERN PIEDMONT AND FOOTHILLS COINCIDENT WITH THE LEADING EDGE OF
THE AREA OF MOSTLY LIGHT PRECIPITATION. AS THE 500MB RIDGE AXIS WAS
MOVING EAST AT 12Z...THE FLOW WAS WEAKLY DIFFLUENT ALOFT...FORECAST
BY THE RAP TO CONTINUE INTO THE AFTERNOON. THE 850MB FLOW WAS FROM
THE SOUTHEAST AND IN CONJUNCTION WITH WEAK ISENTROPIC LIFT NOTED BY
THE RAP ON THE 310K SURFACE THAT SEEMS TO INCREASE THIS MORNING TO A
MAXIMUM EARLY THIS AFTERNOON...GRADUALLY TAKING ON A SOUTHWEST-TO-
NORTHEAST ORIENTATION LATE IN THE DAY AND THIS EVENING AND
ESPECIALLY WEST OF U.S. 1 THEN. 850MB THETA-E ADVECTION GRADUALLY
EXTENDS EAST INTO THE COASTAL PLAIN DURING THE DAY THEN IS ACTUALLY
FORECAST BY THE RAP TO RETREAT WEST THIS EVENING.
RADAR TRENDS HAVE SHOWN A STEADY INCREASE IN LIGHT PRECIPITATION
JUST WEST OF THE TRIANGLE AND FAYETTEVILLE TO INCLUDE CERTAINLY THE
TRIAD...AND ANTICIPATE THIS TO CONTINUE FILLING IN SOME WITH
NUMEROUS PATCHES OF SHOWERS AND LIGHT RAIN. FOR MUCH OF THE DAY IN
MANY OF THE LOCATIONS WHERE CHANCES OF PRECIPITATION ARE HIGHER...
IT COULD BE A SITUATION OF HIGH POP AND LOW QPF. FARTHER
EAST...THERE WERE ACTUALLY BREAKS IN THE CLOUDS TOWARD KFAY AND
KCTZ...AND JUST EAST OF KIXA...ALL OF WHICH SHOULD MOSTLY FILL IN
WITH TIME. ON THE EDGES OF CENTRAL NORTH CAROLINA ESPECIALLY TO THE
EAST...THERE SHOULD BE AT LEAST A FEW GLIMPSES OF SUN WITH THE 850MB
THETA-E GRADIENT LOCATED THERE FOR THE AFTERNOON.
TEMPERATURES ARE AGAIN A CHALLENGE BUT THE LATEST FORECAST HAS A
BASIC PERSISTENCE FORECAST FROM HIGHS SUNDAY WHICH...BASED ON THE
LATEST VISIBLE SATELLITE IMAGE...SEEMS ON TRACK. TEMPERATURES SHOULD
STRUGGLE TO RISE IN THE TRIAD THOUGH SOME AREAS IN THE FAR EAST LIKE
KETC AND KCTZ MAY BE FORECAST TOO COOL. LOWS TONIGHT IN THE UPPER
60S AND LOWER 70S WITH RELATIVELY HIGHER CHANCES FOR PRECIPITATION
IN THE NORTHWEST PIEDMONT OVERNIGHT...LESSER TOWARD INTERSTATE 95.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE SURFACE HIGH AIDING THE COLD AIR DAMMING AIRMASS OVER THE AREA
WILL RETREAT BY TUESDAY MORNING...AND A SOUTHWESTERLY WIND WILL
DEVELOP AHEAD OF A SHORTWAVE CROSSING THE MIDWEST AND THE ATTENDANT
COLD FRONT APPROACHING FROM THE WEST. WEAK HEIGHT FALLS AND
INCREASINGLY CONFLUENT FLOW OUT AHEAD FO THE FRONT WILL SUPPORT
SCATTERED SHOWERS AND STORMS AS PW INCREASES BACK TOWARD 2 INCHES.
DEEP LAYER SHEAR...WHILE NOT OVERLY IMPRESSIVE...IS FORECAST TO
INCREASE TOWARD 30KT AS A JET STRENGTHENS ALONG THE APPALACHIANS OUT
AHEAD OF THE UPPER TROUGH AXIS. THIS BIGGEST QUESTION WILL BE HOW
MUCH INSTABILITY DEVELOPS DUE TO WEAK LAPSE RATES AND LINGERING
STRATUS IN THE MORNING. NOT ...SREF PROBABILITIES OF MLCAPE
EXCEEDING 1000 J/KG ARE GREATEST OVER THE COASTAL PLAIN WHERE
HEATING WILL BE STRONGEST....WHICH IS DISPLACED FROM THE STRONGEST
SHEAR. THUS...WHILE CONVECTION WILL BE MORE PREVALENT THAT IT HAS
BEEN IN THE PAST FEW DAYS...THE POTENTIAL FOR SEVRE WEATHER APPEARS
LIMITED. WILL RAISE TEMPS A BIT OVER THE SOUTHEAST AND EAST WHERE
FULL HEATING SHOULD BE REALIZED (IF NOT EVERYWHERE)...WITH HIGHS
RANGING FROM THE LOWER 80S NORTHWEST TO UPPER 80S SOUTHEAST.
DRIER AIR WILL BEGIN TO FILTER IN LATE TUESDAY NIGHT...ESPECIALLY
INT HE MID-LEVELS.. AS A NORTHWEST WIND DEVELOPS BEHIND THE COLD
FRONT. WILL MAINTAIN A SLIGHT CHANCE TO CHANCER POP OVER THE EAST
OVERNIGHT WITH LOWS IN THE MID 60S TO AROUND 70.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...
DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE GUIDANCE ARE IN
RELATIVELY GOOD AGREEMENT THIS MORNING...WHOSE SOLUTIONS ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING UPPER
LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS DURING DAYS 3-7.
A PRIMARY SFC COLD FRONT...ONE ACCOMPANYING A LEAD SHORTWAVE TROUGH
FORECAST TO AMPLIFY FROM THE NORTHERN PLAINS THIS MORNING TO THE
MIDDLE ATLANTIC COAST BY EARLY WED...WILL BE NEARING THE NC COAST
WED MORNING...WHILE A SECONDARY ONE IS FORECAST TO SETTLE SSE ACROSS
CENTRAL NC WED EVE-NIGHT. DRIER AND MORE STABLE AIR AT THE SFC AND
ALOFT...THE FORMER EXACERBATED BY 10-15 KTS OF WNW DOWNSLOPE H85
FLOW...WILL RESULT IN DRY; WARM; AND NOTICEABLY BREEZY CONDITIONS
WED...WITH THE MORE APPRECIABLE LOW LEVEL CAA TRAILING THE SECONDARY
FRONT WED NIGHT. HIGHS GENERALLY IN THE MIDDLE TO UPPER 80S...WITH
GENERALLY WESTERLY WINDS OF 10-15 MPH GUSTING TO AROUND 20 MPH.
FOLLOWING CANADIAN HIGH PRESSURE AND ASSOCIATED LOW LEVEL
THICKNESSES WED NIGHT WILL BE SUPPORTIVE OF LOWS MOSTLY IN THE UPPER
50S TO LOWER 60S...WITH FURTHER COOLING POTENTIAL INTO THE LOW-MID
50S WHERE/IF DECOUPLING (SFC CALM) OCCURS...MOST LIKELY IN SHELTERED
WESTERN PIEDMONT LOCATIONS.
THU THROUGH SUN: THE LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE
MID MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A
REINFORCING COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS
THE OH AND TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC
TROUGHING IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW
ALOFT AND ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE
CENTER OF THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH THE WEEKEND. MOISTURE...AT THE SFC AND THROUGH
A DEEP LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE
DRYNESS WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND
PRECIPITABLE WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY
SLOWLY INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-
INDUCED CONVECTION...THROUGH THE WKND. H85 TEMPS IN THE 14-16C
RANGE...SHOULD SUPPORT TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW
NORMAL...COOLEST MID-LATE WEEK.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM MONDAY...
A WEAK BUT FAIRLY DEEP SOUTHEASTERLY FLOW CONTINUES OVER CENTRAL NC
THIS MORNING. POCKETS OF LIGHT RAIN AND DRIZZLE OVER THE SOUTHERN
PIEDMONT HAVE BEEN FAIRLY LIGHT AND DRIFTING VERY SLOWLY TO THE
NORTH. PRECIP HAS BEEN EXPANDING OVER THE FOOTHILLS THIS MORNING
AND WILL SLOWLY SPREAD EAST ACROSS THE TRIAD THROUGH MIDDAY. LOW
CLOUDS WILL CONTINUE TO BE FAVORED OVER WESTERN PORTIONS OF THE
AREA...WITH MVFR CEILINGS LIKELY LOWERING TO AT LEAST IFR AT
KGSO/KINT THIS MORNING. ITS A LITTLE UNCLEAR HOW FAR EAST THE SUB-
VFR CEILINGS WILL EXPAND TO THE EAST...SO CONFIDENCE IN MVFR OR IFR
CEILINGS AT KRDU IS LOWER. HOWEVER...THE MOST RECENT RAP AND HRRR
SHOW LESS STRATUS AT KRDU...KRWI AND KFAY...WITH CEILINGS HOVERING
AT HIGH END MVFR OR ABOVE. SHOWERS WILL ALSO BE POSSIBLE IN THE
VICINITY OF KFAY BY THIS AFTERNOON. SUB-VFR CEILINGS ARE THEN LIKELY
TO RETURN TONIGHT.
OUTLOOK.... LOW CEILINGS SHOULD HANG AROUND EARLY TUESDAY AND THEN
SCATTER AND LIGHT AS A SOUTHWESTERLY WIND DEVELOPS ON TUESDAY AHEAD
OF AN APPROACHING COLD FRONT. A FEW SHOWERS AND STORMS WILL BE
POSSIBLE TUESDAY AFTERNOON...WITH DRIER CONDITIONS EXPECTED BEHIND
THE FRONT ONCE IT CROSSES THE AREA ON WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...DJF/BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
743 AM EDT MON AUG 11 2014
.SYNOPSIS...
A COASTAL LOW OFFSHORE OF SOUTH CAROLINA AND A STALLED FRONTAL
BOUNDARY WILL BOTH LIFT SLOWLY NORTH THROUGH TUESDAY. THIS WILL
BRING THE POTENTIAL FOR HEAVY RAINFALL OVER ALREADY WET GROUND. A
FLOOD WATCH IS IN EFFECT FOR THE ENTIRE AREA TODAY. A STRONG COLD
FRONT WILL CROSS THE AREA OVERNIGHT WEDNESDAY...BRINGING DRIER
CONDITIONS AND COOLER NIGHT-TIME TEMPERATURES INTO LATE WEEK.
SEASONABLE WEATHER IS EXPECTED THIS WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM MONDAY...NO SIGNIFICANT CHANGES TO FORECAST REASONING
WITH THE DAYBREAK UPDATES. SEVERAL SIGNALS REMAIN IN PLACE FOR A
POTENTIAL OF LOCALIZED BUT SIGNIFICANT FLOODING. NESDIS RELEASED A
SATELLITE PRECIPITATION ESTIMATES MESSAGE FOR THE CHS AND ILM
WARNING AREAS FOR INGREDIENTS IN PLACE FOR POSSIBLE HEAVY RAIN
LATER THIS MORNING. LATEST RADAR TRENDS SHOW CELLS TEAMING UP
OFFSHORE IN WHAT APPEARS TO BE A SHARPENING AXIS OF LOW-LEVEL
CONVERGENCE. KLTX VAD WIND PROFILE SHOWS 25 KT EAST WIND FLOW OFF
THE BALMY ATLANTIC IN THE LOWEST FEW THOUSAND FEET INDUCING AN
INFERRED AND CORRESPONDING INCREASE IN 975-925 MOISTURE TRANSPORT
VECTORS...BUT AS YET RADAR ECHOS REMAIN OVER THE OUTER WATERS. THE
PREVIOUS EARLY MORNING DISCUSSION FOLLOWS.
A FLOOD WATCH IS POSTED FOR NE SC AND SE NC DUE TO THE POTENTIAL
ONCE AGAIN FOR SCATTERED TORRENTIAL RAINS OVER SOGGY GROUND AND
EVEN STANDING WATER AREAS ACROSS OUR ZONES. SATELLITE SENSORS ARE
REGISTERING A POOL OF DEEP COLUMN MOISTURE IN EXCESS OF 2 INCH
PRECIPITABLE WATER VALUE...ACROSS MOST OF THE GULF STATES
EXTENDING NE INTO SC AND COASTAL NC. AN EDDY IN THIS POOL WILL
WELL-UP NORTHWARD AS AN UPPER RIDGE AMPLIFIES ALONG THE EASTERN
SEABOARD LATER TODAY. IT APPEARS MOISTURE MAY IN FACT DEEPEN
FURTHER BY THIS AFTERNOON AND INTO EVENING.
DISCONCERTING IS THAT PROJECTED CELL MOTION TODAY MAY NOT EXCEED
10 KT IN THE HEAVY RAIN CORES. ALSO OF CONCERN IS A COASTAL LOW
OFFSHORE OF SC PRESENTLY THAT WILL BE DRAWN SLIGHTLY NORTHWARD
TODAY. THIS FEATURE WILL SHARPEN MOISTURE TRANSPORT IN THE LOW
LEVELS OFF THE BALMY SEA AS THE SYNOPTIC GRADIENT BECOMES A BIT
MORE PINCHED. THIS SFC-850 TRANSPORT MAY ALSO INDUCE ISENTROPIC
RAINS OVER OUR NORTHERN INTERIOR ZONES LATER TODAY...AND FOR THIS
REASON THE FLOOD WATCH IS POSTED FOR ALL ILM ZONES.
COVERAGE MAY REMAIN SCATTERED SUGGESTING LOCALIZED FLOODING BUT IT
COULD BE SIGNIFICANT IF TRAINING OR QUASI-STATIONARY CELL MOTION
DEVELOPS LATER TODAY AS THE 4KM WRF AND HRRR NEAR TERM MODELS ARE
HINTING AT. ANY PARTIAL SUNSHINE TODAY WILL ONLY BOOST SURFACE
BASED CONVECTIVE ENERGY IN NEARLY A PURE TROPICAL AIR MASS.
THE CLOUDS AND ANTICIPATED RAIN WITH A FEW PEEKS OF SUNSHINE IN
SPOTS SHOULD BRING MAXIMUMS INTO THE LOW AND MIDDLE 80S TODAY.
MINIMUMS 70S TONIGHT AND MILDEST COAST ALTHOUGH ADMITTEDLY THE
CLOUDS AND POTENTIAL RAINFALL NAY BRING NON-UNIFORMITY TO LOWS
EARLY MONDAY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 330 AM MONDAY...FINALLY SOME SEASONABLE TEMPERATURES FOR THE
SHORT TERM AS A DRYING TREND COMMENCES BEGINNING WEDNESDAY.
TUESDAY IS EXPECTED TO BE THE LAST DAY OF WIDESPREAD PRECIP AND COOL
TEMPERATURES. SHARP AND STRONG 500MB TROUGH WILL BE MOVING ACROSS
THE GREAT LAKES...LEAVING LOWERED MID-LEVEL HEIGHTS BUT WITH S/SW
FLOW THROUGH THE COLUMN. THIS CREATES A SITUATION WITH PWATS
REMAINING WELL ABOVE 2 INCHES...AND AS UPPER IMPULSES ROTATE THROUGH
THE AFOREMENTIONED TROUGH...PRECIP WILL OCCUR ACROSS THE AREA.
ALTHOUGH THE STALLED BOUNDARY FROM THIS PAST WKND WILL LIKELY LIFT
NORTH DURING TUESDAY...ANY STRONG WAA BEHIND IT WILL BE TEMPERED BY
CLOUDS AND CONVECTION...SO HIGHS WILL STAY JUST BELOW
NORMAL...ALTHOUGH WARMER THAN THE PREVIOUS FEW DAYS. EXPECT HIGHS IN
THE UPPER 80S...MID 80S FAR NORTH. MOS P-NUMBERS ARE IN THE HIGH
CHC/LIKELY RANGE FOR TUESDAY...AND THIS MATCHES INHERITED WELL. THUS
WILL MAKE MINIMAL CHANGES TO POP FOR TUESDAY...BUT WILL RAMP POP
DOWN QUICKLY TUESDAY NIGHT AS MID-LEVEL DRYING BEGINS.
HOWEVER...SOME PLACES COULD ONCE AGAIN SEE PERIODS OF HEAVY RAINFALL
THE FIRST HALF OF TUESDAY. LOWS WILL FALL ONLY INTO THE MID 70S
THANKS TO CONTINUED WARM SURFACE WINDS.
WEDNESDAY LOOKS TO BE A WARM DAY...ABOVE NORMAL ACROSS THE
AREA...THANKS TO ENHANCED RETURN FLOW AHEAD OF A COLD FRONT AND DRY
WESTERLY MID-LEVEL FLOW. CHC FOR CONVECTION WEDNESDAY WILL BE QUITE
MINIMAL AS PWATS DROP BELOW 1.5 INCHES EVEN AHEAD OF THE COLD
FRONT...AND THEN TO LESS THAN 1 INCH BEHIND IT WED NIGHT. BEST
CHANCE FOR ANY SHOWERS WILL BE EARLY WEDNESDAY ALONG THE
COAST...BEFORE CLEARING OCCURS DURING THE AFTN/EVE...AND THE SUN IS
EXPECTED TO SHINE ON WEDNESDAY! TEMPS WILL WARM INTO THE LOW 90S
AWAY FROM THE BEACHES...WITH LOWS DROPPING TO A DEGREE OR TWO EITHER
SIDE OF 70.
FOR THOSE HOPING TO VIEW TO ANNUAL PERSEID METEOR SHOWER...ALTHOUGH
THE PEAK IS TUESDAY NIGHT/WEDNESDAY MORNING...THE BEST CHANCE FOR
VIEWING LOCALLY WILL BE WEDNESDAY NIGHT/THURSDAY MORNING AS THE SKY
WILL FINALLY CLEAR. VIEWERS WILL STILL NEED TO DEAL WITH A NEARLY
FULL MOON...BUT METEORS SHOULD BE VISIBLE WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 330 AM MONDAY...A PERIOD OF ACTUAL SUMMER-LIKE WEATHER
EXPECTED FOR THE END OF THE WEEK AND INTO THE WEEKEND AS WESTERLY
MID-LEVEL FLOW DEVELOPS AND PERSISTS THROUGH THE PERIOD.
COLD FRONT WILL BE OFFSHORE THURSDAY MORNING...AND WILL BECOME
STALLED OFFSHORE THROUGH THE PERIOD. ALOFT...THE CAROLINAS WILL BE
ENTRENCHED BETWEEN A DEEP UPPER LOW OVER SOUTHEAST CANADA...AND A
HIGH PRESSURE EXPANDING ACROSS THE BAHAMAS. THIS LEAVES PINCHED
MID-LEVEL FLOW FROM THE WEST THU-SAT...WHICH IS TYPICALLY A DRYING
DIRECTION LOCALLY. AT THE SURFACE...THE COLD FRONT WILL REMAIN OFF
THE COAST...WHILE HIGH PRESSURE BENEATH THE BAHAMAS RIDGE EXPANDS
WEST OVER THE ATLANTIC...DRIVING SW RETURN FLOW INTO THE AREA. THIS
SUGGESTS A FEW WARM AND SUNNY DAYS THU-SAT WITH TEMPS AROUND
SEASONABLE VALUES BOTH DURING THE DAY AND AT NIGHT. TYPICAL DIURNAL
SHOWERS/TSTMS CANNOT BE RULED OUT FRI/SAT...BUT COVERAGE WILL BE
ISOLATED AND WILL KEEP POP SILENT. BY SUNDAY THE MID-LEVEL FLOW
WEAKENS AS THE CANADIAN LOW PULLS OFF TO THE EAST...AND MORE
COVERAGE OF DIURNAL CONVECTION WILL BE POSSIBLE.
AS NOTED BY THE PREVIOUS FORECASTER...THERE IS ONE CAVEAT TO THE
EXTENDED...AND THAT INVOLVES THE RIPPLING OF THE COLD FRONT
OFFSHORE. AS WEAK IMPULSES TRAVERSE THROUGH THE LONGWAVE TROUGH
ALOFT...THEY WILL TRY TO PULL THIS FRONT BACK TOWARDS THE COAST
FRI/SAT/SUN. IF THIS OCCURS IT COULD ENHANCE PRECIP POTENTIAL LATE
IN THE WEEK AND ON THE WEEKEND...BUT ATTM WITH THE WESTERLY FLOW
EXPECTED TO BE PRETTY STRONG...WILL OPT FOR THE DRIER SOLUTION
DURING THIS PERIOD.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...EXCEPT FOR IFR CIGS AT KFLO...TERMINALS ARE VFR THIS
MORNING. SKIES ARE SCT TO CLEAR...BUT 11U-3.9U SATELLITE LOOPS
SHOW MID CLOUDS BEGINNING TO SPREAD BACK ACROSS THE TERMINALS.
ONLY ISOLATED VERY LIGHT SHOWERS ARE OCCURRING. RADAR LOOPS SHOW
SHOWERS MOVING/DEVELOPING WNW...WHILE TOPS ARE BEING BLOWN OFF TO
THE SE. WINDS ARE NE-ENE 5-10 KT...HIGHEST AT THE COASTAL
TERMINALS.
SHOWERS WILL CONTINUE TO DEVELOP TODAY WITH RAINFALL BECOMING
MORE WIDESPREAD AND MODERATE TO HEAVY AT TIMES. CONFIDENCE IS HIGH
THERE WILL BE PERIODS OF MVFR CIGS/VSBYS THROUGH THIS AFTERNOON
ASSOCIATED WITH THE SHOWER ACTIVITY. IFR COULD OCCUR IF CELLS
MOVE DIRECTLY OVER A TERMINAL. DUE TO COVERAGE FEEL THE CHANCE OF
GOOD TIMING OF IFR VSBYS WITH THE SHOWERS AT ANY SPECIFIC TERMINAL
WILL BE LOW.
MODELS ALL AGREE THERE WILL BE A DECREASE IN SHOWER ACTIVITY THIS
EVENING AND OVERNIGHT. IFR CONDITIONS IN FOG WILL DEVELOP AT
KFLO/KLBT AFTER MIDNIGHT...WITH TEMPO LIFR POSSIBLE 09-12Z. THE
COASTAL TERMINALS SHOULD REMAIN MVFR OR GREATER.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM MONDAY...A BUMPY 3-4 FEET EXPECTED TODAY AS WINDS
INCREASE DUE TO THE SLOW APPROACH OF A COASTAL LOW OFF OF SC EARLY
THIS MORNING. THIS FEATURE WILL INTERACT WITH A HIGH PRESSURE
WEDGE INLAND TODAY AND TONIGHT. A CAUTION STATEMENT CANNOT BE
RULED OUT LATER TODAY OR TONIGHT BUT RIGHT NOW IT LOOKS LIKE WE
MAY NOT NEED ONE. TSTMS AND TORRENTIAL SHOWERS ARE POSSIBLE ON THE
WATERS AND THIS WILL REDUCE VSBYS LESS THAN 1 NM AT TIMES.
MARINERS SHOULD CONSIDER GETTING A RADAR BRIEFING OR LOOK BEFORE
HEADING OUT TODAY OR TONIGHT. SEA SPECTRUM WILL BE COMPRISED OF E
WAVES 3 FEET EVERY 3-5 SECONDS...AND SE WAVES 1-1.5 FEET IN 8-10
SECOND INTERVALS. ONSHORE WINDS WILL PERSIST THROUGH DAYBREAK
TUESDAY BUT WIND SPEEDS SHOULD DROP-OFF AS THE LOW WEAKENS BUT
DOES REMAIN OVERHEAD OF THE LOCAL WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM MONDAY...TWO DISTINCT FRONTS WILL MOVE ACROSS THE
WATERS DURING THE SHORT TERM. THE FIRST...A WARM FRONT...WILL LIFT
NORTH OVER THE WATERS EARLY TUESDAY...CREATING WINDS THAT WILL
INCREASE FROM THE S/SW TO 10-15 KTS MUCH OF TUESDAY. THESE WINDS
WILL CONTINUE INTO WEDNESDAY AHEAD OF A COLD FRONT WHICH WILL CROSS
THE WATERS BY EARLY THURSDAY...TURNING WINDS TO THE NORTH AROUND 10
KTS AT THE END OF THE PERIOD. ALTHOUGH S/SW WINDS WILL BE FEATURED
THROUGH THE MAJORITY OF THE PERIOD...THE SEA SPECTRUM WILL BECOME
CONFUSED AT TIMES WITH THE WIND SHIFTS AND LACK OF SIGNIFICANT
SWELL. HIGHEST WAVES WILL BE LATE TUESDAY AND MUCH OF WEDNESDAY WHEN
THEY WILL REACH 3-4 FT. OTHERWISE...EXPECT 2-3 FT SEAS.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 330 AM MONDAY...COLD FRONT MOVING OFFSHORE AT THE START OF THE
PERIOD WILL LEAVE NORTH WINDS AROUND 10 KTS IN ITS WAKE...BECOMING
E/NE THROUGH THE AFTN. THE PRESSURE GRADIENT THEN BECOMES QUITE
DIFFUSE THROUGH THE END OF THE WEEK AS THE FRONT STALLS OFFSHORE.
THIS WILL DRIVE ONLY LIGHT AND VARIABLE WINDS MUCH OF FRIDAY. THE
OFFSHORE WINDS...FOLLOWED BY VERY LIGHT WINDS...WILL KEEP SEAS TO
LOW AMPLITUDE BOTH DAYS...1-3 FT THURSDAY AND 1-2 FT ON FRIDAY.
&&
.TIDES/COASTAL FLOODING...
AS OF 6 AM MONDAY...STRONG ASTRONOMICAL TIDES WITH THIS WANING
FULL MOON CYCLE WILL REQUIRE ANOTHER COASTAL FLOOD ADVISORY WITH
THIS EVENINGS HIGH TIDE FOR ALL BEACHES AND THE LOWER CAPE FEAR
RIVER SIMILAR TO THE LAST 2 EVENINGS...BUT LIKELY A FEW INCHES
LOWER ON THE PEAK WATER LEVELS. ELEVATED LEVELS WILL BE OBSERVED
ALONG THE BANKS OF THE ICW AS WELL DURING HIGH TIDE. THE LOWER
CAPE FEAR RIVER WILL EXPERIENCE MINOR COASTAL FLOODING INCLUDING
LOCALIZED SPOTS IN DOWNTOWN WILMINGTON. PREDICTED TIDE LEVELS SHOW
WE MAY NOT NEED THE ADVISORY TUESDAY NIGHT FOR THE BEACHES...BUT
THE LOWER CAPE FEAR WILL NEED AN ADVISORY FOR A FEW DAYS OF THE
NIGHT-TIME HIGH TIDE CYCLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH THIS EVENING FOR SCZ017-023-024-032-033-
039-053>056.
COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
SCZ054-056.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ087-096-099-105>110.
COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 1 AM EDT
TUESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MRR
MARINE...MJC/JDW
TIDES/COASTAL FLOODING...MJC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
730 AM EDT MON AUG 11 2014
.SYNOPSIS...A RIDGE OF HIGH PRESSURE EXTENDING INTO CENTRAL NC FROM
THE NORTHEAST TODAY WILL WEAKEN TONIGHT...ALLOWING A STATIONARY FRONT
OVER SOUTH CAROLINA TO SLOWLY LIFT NORTH AS A WARM FRONT ON TUESDAY.
A COLD FRONT WILL THEN MOVE INTO THE AREA FROM THE NORTHWEST ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM MONDAY...
A 1021 MB SURFACE HIGH CENTERED OVER NEW ENGLAND CONTINUES TO EXTEND
INTO THE CAROLINAS...WHILE A FRONTAL ZONE IS STATIONARY NEAR THE
SAVANNAH RIVER BASIN. A MOIST SOUTHERLY FLOW...ALBEIT LIGHT..WAS
OBSERVED THROUGH 700MB ON THE 00Z RAOBS...AND WEAK ISENTROPIC LIFT
CONTINUES TO SUPPORT SOME PATCHES OF LIGHT RAIN...MAINLY ACROSS THE
SOUTHERN PIEDMONT EARLY THIS MORNING. MOST NWP SHOWS THE FOCUS OF
ISENTROPIC LIFT SHIFTING TOWARD THE WESTER PIEDMONT THIS
MORNING...THEN OFF TO THE NORTH LATER THIS AFTERNOON/EVENING AS THE
FLOW ABOVE 925MB VEERS AROUND TO MORE SOUTHERLY AHEAD OF A SYSTEM
MOVING INTO THE MIDWEST. WINDS BELOW 925MB SHOULD REMAIN OUT OF THE
EAST AS A SECONDARY WAVE OF LOW PRESSURE MIGRATES ALONG THE THE
SURFACE FRONT..SO AT LEAST SOME WEAK WARM ADVECTION AND A CHANCE OF
RAIN WILL CONTINUE THROUGH TONIGHT. ANY APPRECIABLE INSTABILITY
WILL STAY TO OUR SOUTH WITH THE FRONTAL ZONE...THOUGH A LITTLE
BETTER HEATING OVER THE SOUTHEAST MAY ALLOW SOME PRECIP TO BECOME
MORE SHOWERY LATER THIS AFTERNOON. MODEL QPF IS HIGHEST FROM THE
SANDHILLS TO THE WESTERN PIEDMONT...GENERALLY SHOWING AROUND A
QUARTER TO A THIRD OF AN INCH IN SPOTS TODAY. AREAS TO THE
NORTHEAST OF THE TRIANGLE SHOULD SEE MUCH LESS. CONCERNING FLOOD
POTENTIAL...THERE HAVE BEEN SOME HEAVY RAINFALL TOTALS OVER THE PAST
COUPLE OF DAYS...BUT AT THIS TIME IT DOESNT APPEAR RAINFALL RATES
WOULD SUPPORT A FLASH FLOOD WATCH FOR TODAY. THAT BEING SAID...IF
SOME OF THE PRECIP BECOMES A LITTLE MORE CONVECTIVE IN NATURE ACROSS
THE SOUTHEAST CWA...THEN SOME MINOR FLOODING MAY BE POSSIBLE.
HEATING WILL AGAIN BE LIMITED OVER THE NORTHWEST PIEDMONT DUE TO
PERSISTENT...SO WILL GO WITH A TEMP RANGE SIMILAR TO THAT OBSERVED
ON SUNDAY WITH LOWER 70S NORTHWEST TO AROUND 80 IN THE EAST. LOWS
TONIGHT IN THE UPPER 60S AND LOWER 70S
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE SURFACE HIGH AIDING THE COLD AIR DAMMING AIRMASS OVER THE AREA
WILL RETREAT BY TUESDAY MORNING...AND A SOUTHWESTERLY WIND WILL
DEVELOP AHEAD OF A SHORTWAVE CROSSING THE MIDWEST AND THE ATTENDANT
COLD FRONT APPROACHING FROM THE WEST. WEAK HEIGHT FALLS AND
INCREASINGLY CONFLUENT FLOW OUT AHEAD FO THE FRONT WILL SUPPORT
SCATTERED SHOWERS AND STORMS AS PW INCREASES BACK TOWARD 2 INCHES.
DEEP LAYER SHEAR...WHILE NOT OVERLY IMPRESSIVE...IS FORECAST TO
INCREASE TOWARD 30KT AS A JET STRENGTHENS ALONG THE APPALACHIANS OUT
AHEAD OF THE UPPER TROUGH AXIS. THIS BIGGEST QUESTION WILL BE HOW
MUCH INSTABILITY DEVELOPS DUE TO WEAK LAPSE RATES AND LINGERING
STRATUS IN THE MORNING. NOT ...SREF PROBABILITIES OF MLCAPE
EXCEEDING 1000 J/KG ARE GREATEST OVER THE COASTAL PLAIN WHERE
HEATING WILL BE STRONGEST....WHICH IS DISPLACED FROM THE STRONGEST
SHEAR. THUS...WHILE CONVECTION WILL BE MORE PREVALENT THAT IT HAS
BEEN IN THE PAST FEW DAYS...THE POTENTIAL FOR SEVRE WEATHER APPEARS
LIMITED. WILL RAISE TEMPS A BIT OVER THE SOUTHEAST AND EAST WHERE
FULL HEATING SHOULD BE REALIZED (IF NOT EVERYWHERE)...WITH HIGHS
RANGING FROM THE LOWER 80S NORTHWEST TO UPPER 80S SOUTHEAST.
DRIER AIR WILL BEGIN TO FILTER IN LATE TUESDAY NIGHT...ESPECIALLY
INT HE MID-LEVELS.. AS A NORTHWEST WIND DEVELOPS BEHIND THE COLD
FRONT. WILL MAINTAIN A SLIGHT CHANCE TO CHANCER POP OVER THE EAST
OVERNIGHT WITH LOWS IN THE MID 60S TO AROUND 70.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...
DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE GUIDANCE ARE IN
RELATIVELY GOOD AGREEMENT THIS MORNING...WHOSE SOLUTIONS ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING UPPER
LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS DURING DAYS 3-7.
A PRIMARY SFC COLD FRONT...ONE ACCOMPANYING A LEAD SHORTWAVE TROUGH
FORECAST TO AMPLIFY FROM THE NORTHERN PLAINS THIS MORNING TO THE
MIDDLE ATLANTIC COAST BY EARLY WED...WILL BE NEARING THE NC COAST
WED MORNING...WHILE A SECONDARY ONE IS FORECAST TO SETTLE SSE ACROSS
CENTRAL NC WED EVE-NIGHT. DRIER AND MORE STABLE AIR AT THE SFC AND
ALOFT...THE FORMER EXACERBATED BY 10-15 KTS OF WNW DOWNSLOPE H85
FLOW...WILL RESULT IN DRY; WARM; AND NOTICEABLY BREEZY CONDITIONS
WED...WITH THE MORE APPRECIABLE LOW LEVEL CAA TRAILING THE SECONDARY
FRONT WED NIGHT. HIGHS GENERALLY IN THE MIDDLE TO UPPER 80S...WITH
GENERALLY WESTERLY WINDS OF 10-15 MPH GUSTING TO AROUND 20 MPH.
FOLLOWING CANADIAN HIGH PRESSURE AND ASSOCIATED LOW LEVEL
THICKNESSES WED NIGHT WILL BE SUPPORTIVE OF LOWS MOSTLY IN THE UPPER
50S TO LOWER 60S...WITH FURTHER COOLING POTENTIAL INTO THE LOW-MID
50S WHERE/IF DECOUPLING (SFC CALM) OCCURS...MOST LIKELY IN SHELTERED
WESTERN PIEDMONT LOCATIONS.
THU THROUGH SUN: THE LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE
MID MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A
REINFORCING COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS
THE OH AND TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC
TROUGHING IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW
ALOFT AND ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE
CENTER OF THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH THE WEEKEND. MOISTURE...AT THE SFC AND THROUGH
A DEEP LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE
DRYNESS WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND
PRECIPITABLE WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY
SLOWLY INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-
INDUCED CONVECTION...THROUGH THE WKND. H85 TEMPS IN THE 14-16C
RANGE...SHOULD SUPPORT TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW
NORMAL...COOLEST MID-LATE WEEK.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM MONDAY...
A WEAK BUT FAIRLY DEEP SOUTHEASTERLY FLOW CONTINUES OVER CENTRAL NC
THIS MORNING. POCKETS OF LIGHT RAIN AND DRIZZLE OVER THE SOUTHERN
PIEDMONT HAVE BEEN FAIRLY LIGHT AND DRIFTING VERY SLOWLY TO THE
NORTH. PRECIP HAS BEEN EXPANDING OVER THE FOOTHILLS THIS MORNING
AND WILL SLOWLY SPREAD EAST ACROSS THE TRIAD THROUGH MIDDAY. LOW
CLOUDS WILL CONTINUE TO BE FAVORED OVER WESTERN PORTIONS OF THE
AREA...WITH MVFR CEILINGS LIKELY LOWERING TO AT LEAST IFR AT
KGSO/KINT THIS MORNING. ITS A LITTLE UNCLEAR HOW FAR EAST THE SUB-
VFR CEILINGS WILL EXPAND TO THE EAST...SO CONFIDENCE IN MVFR OR IFR
CEILINGS AT KRDU IS LOWER. HOWEVER...THE MOST RECENT RAP AND HRRR
SHOW LESS STRATUS AT KRDU...KRWI AND KFAY...WITH CEILINGS HOVERING
AT HIGH END MVFR OR ABOVE. SHOWERS WILL ALSO BE POSSIBLE IN THE
VICINITY OF KFAY BY THIS AFTERNOON. SUB-VFR CEILINGS ARE THEN LIKELY
TO RETURN TONIGHT.
OUTLOOK.... LOW CEILINGS SHOULD HANG AROUND EARLY TUESDAY AND THEN
SCATTER AND LIGHT AS A SOUTHWESTERLY WIND DEVELOPS ON TUESDAY AHEAD
OF AN APPROACHING COLD FRONT. A FEW SHOWERS AND STORMS WILL BE
POSSIBLE TUESDAY AFTERNOON...WITH DRIER CONDITIONS EXPECTED BEHIND
THE FRONT ONCE IT CROSSES THE AREA ON WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
556 AM EDT MON AUG 11 2014
.SYNOPSIS...
A COASTAL LOW OFFSHORE OF SOUTH CAROLINA AND A STALLED FRONTAL
BOUNDARY WILL BOTH LIFT SLOWLY NORTH THROUGH TUESDAY. THIS WILL
BRING THE POTENTIAL FOR HEAVY RAINFALL OVER ALREADY WET GROUND. A
FLOOD WATCH IS IN EFFECT FOR THE ENTIRE AREA TODAY. A STRONG COLD
FRONT WILL CROSS THE AREA OVERNIGHT WEDNESDAY...BRINGING DRIER
CONDITIONS AND COOLER NIGHT-TIME TEMPERATURES INTO LATE WEEK.
SEASONABLE WEATHER IS EXPECTED THIS WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM MONDAY...NO SIGNIFICANT CHANGES TO FORECAST REASONING
WITH THE DAYBREAK UPDATES. SEVERAL SIGNALS REMAIN IN PLACE FOR A
POTENTIAL OF LOCALIZED BUT SIGNIFICANT FLOODING. NESDIS RELEASED A
SATELLITE PRECIPITATION ESTIMATES MESSAGE FOR THE CHS AND ILM
WARNING AREAS FOR INGREDIENTS IN PLACE FOR POSSIBLE HEAVY RAIN
LATER THIS MORNING. LATEST RADAR TRENDS SHOW CELLS TEAMING UP
OFFSHORE IN WHAT APPEARS TO BE A SHARPENING AXIS OF LOW-LEVEL
CONVERGENCE. KLTX VAD WIND PROFILE SHOWS 25 KT EAST WIND FLOW OFF
THE BALMY ATLANTIC IN THE LOWEST FEW THOUSAND FEET INDUCING AN
INFERRED AND CORRESPONDING INCREASE IN 975-925 MOISTURE TRANSPORT
VECTORS...BUT AS YET RADAR ECHOS REMAIN OVER THE OUTER WATERS. THE
PREVIOUS EARLY MORNING DISCUSSION FOLLOWS.
A FLOOD WATCH IS POSTED FOR NE SC AND SE NC DUE TO THE POTENTIAL
ONCE AGAIN FOR SCATTERED TORRENTIAL RAINS OVER SOGGY GROUND AND
EVEN STANDING WATER AREAS ACROSS OUR ZONES. SATELLITE SENSORS ARE
REGISTERING A POOL OF DEEP COLUMN MOISTURE IN EXCESS OF 2 INCH
PRECIPITABLE WATER VALUE...ACROSS MOST OF THE GULF STATES
EXTENDING NE INTO SC AND COASTAL NC. AN EDDY IN THIS POOL WILL
WELL-UP NORTHWARD AS AN UPPER RIDGE AMPLIFIES ALONG THE EASTERN
SEABOARD LATER TODAY. IT APPEARS MOISTURE MAY IN FACT DEEPEN
FURTHER BY THIS AFTERNOON AND INTO EVENING.
DISCONCERTING IS THAT PROJECTED CELL MOTION TODAY MAY NOT EXCEED
10 KT IN THE HEAVY RAIN CORES. ALSO OF CONCERN IS A COASTAL LOW
OFFSHORE OF SC PRESENTLY THAT WILL BE DRAWN SLIGHTLY NORTHWARD
TODAY. THIS FEATURE WILL SHARPEN MOISTURE TRANSPORT IN THE LOW
LEVELS OFF THE BALMY SEA AS THE SYNOPTIC GRADIENT BECOMES A BIT
MORE PINCHED. THIS SFC-850 TRANSPORT MAY ALSO INDUCE ISENTROPIC
RAINS OVER OUR NORTHERN INTERIOR ZONES LATER TODAY...AND FOR THIS
REASON THE FLOOD WATCH IS POSTED FOR ALL ILM ZONES.
COVERAGE MAY REMAIN SCATTERED SUGGESTING LOCALIZED FLOODING BUT IT
COULD BE SIGNIFICANT IF TRAINING OR QUASI-STATIONARY CELL MOTION
DEVELOPS LATER TODAY AS THE 4KM WRF AND HRRR NEAR TERM MODELS ARE
HINTING AT. ANY PARTIAL SUNSHINE TODAY WILL ONLY BOOST SURFACE
BASED CONVECTIVE ENERGY IN NEARLY A PURE TROPICAL AIR MASS.
THE CLOUDS AND ANTICIPATED RAIN WITH A FEW PEEKS OF SUNSHINE IN
SPOTS SHOULD BRING MAXIMUMS INTO THE LOW AND MIDDLE 80S TODAY.
MINIMUMS 70S TONIGHT AND MILDEST COAST ALTHOUGH ADMITTEDLY THE
CLOUDS AND POTENTIAL RAINFALL NAY BRING NON-UNIFORMITY TO LOWS
EARLY MONDAY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 330 AM MONDAY...FINALLY SOME SEASONABLE TEMPERATURES FOR THE
SHORT TERM AS A DRYING TREND COMMENCES BEGINNING WEDNESDAY.
TUESDAY IS EXPECTED TO BE THE LAST DAY OF WIDESPREAD PRECIP AND COOL
TEMPERATURES. SHARP AND STRONG 500MB TROUGH WILL BE MOVING ACROSS
THE GREAT LAKES...LEAVING LOWERED MID-LEVEL HEIGHTS BUT WITH S/SW
FLOW THROUGH THE COLUMN. THIS CREATES A SITUATION WITH PWATS
REMAINING WELL ABOVE 2 INCHES...AND AS UPPER IMPULSES ROTATE THROUGH
THE AFOREMENTIONED TROUGH...PRECIP WILL OCCUR ACROSS THE AREA.
ALTHOUGH THE STALLED BOUNDARY FROM THIS PAST WKND WILL LIKELY LIFT
NORTH DURING TUESDAY...ANY STRONG WAA BEHIND IT WILL BE TEMPERED BY
CLOUDS AND CONVECTION...SO HIGHS WILL STAY JUST BELOW
NORMAL...ALTHOUGH WARMER THAN THE PREVIOUS FEW DAYS. EXPECT HIGHS IN
THE UPPER 80S...MID 80S FAR NORTH. MOS P-NUMBERS ARE IN THE HIGH
CHC/LIKELY RANGE FOR TUESDAY...AND THIS MATCHES INHERITED WELL. THUS
WILL MAKE MINIMAL CHANGES TO POP FOR TUESDAY...BUT WILL RAMP POP
DOWN QUICKLY TUESDAY NIGHT AS MID-LEVEL DRYING BEGINS.
HOWEVER...SOME PLACES COULD ONCE AGAIN SEE PERIODS OF HEAVY RAINFALL
THE FIRST HALF OF TUESDAY. LOWS WILL FALL ONLY INTO THE MID 70S
THANKS TO CONTINUED WARM SURFACE WINDS.
WEDNESDAY LOOKS TO BE A WARM DAY...ABOVE NORMAL ACROSS THE
AREA...THANKS TO ENHANCED RETURN FLOW AHEAD OF A COLD FRONT AND DRY
WESTERLY MID-LEVEL FLOW. CHC FOR CONVECTION WEDNESDAY WILL BE QUITE
MINIMAL AS PWATS DROP BELOW 1.5 INCHES EVEN AHEAD OF THE COLD
FRONT...AND THEN TO LESS THAN 1 INCH BEHIND IT WED NIGHT. BEST
CHANCE FOR ANY SHOWERS WILL BE EARLY WEDNESDAY ALONG THE
COAST...BEFORE CLEARING OCCURS DURING THE AFTN/EVE...AND THE SUN IS
EXPECTED TO SHINE ON WEDNESDAY! TEMPS WILL WARM INTO THE LOW 90S
AWAY FROM THE BEACHES...WITH LOWS DROPPING TO A DEGREE OR TWO EITHER
SIDE OF 70.
FOR THOSE HOPING TO VIEW TO ANNUAL PERSEID METEOR SHOWER...ALTHOUGH
THE PEAK IS TUESDAY NIGHT/WEDNESDAY MORNING...THE BEST CHANCE FOR
VIEWING LOCALLY WILL BE WEDNESDAY NIGHT/THURSDAY MORNING AS THE SKY
WILL FINALLY CLEAR. VIEWERS WILL STILL NEED TO DEAL WITH A NEARLY
FULL MOON...BUT METEORS SHOULD BE VISIBLE WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 330 AM MONDAY...A PERIOD OF ACTUAL SUMMER-LIKE WEATHER
EXPECTED FOR THE END OF THE WEEK AND INTO THE WEEKEND AS WESTERLY
MID-LEVEL FLOW DEVELOPS AND PERSISTS THROUGH THE PERIOD.
COLD FRONT WILL BE OFFSHORE THURSDAY MORNING...AND WILL BECOME
STALLED OFFSHORE THROUGH THE PERIOD. ALOFT...THE CAROLINAS WILL BE
ENTRENCHED BETWEEN A DEEP UPPER LOW OVER SOUTHEAST CANADA...AND A
HIGH PRESSURE EXPANDING ACROSS THE BAHAMAS. THIS LEAVES PINCHED
MID-LEVEL FLOW FROM THE WEST THU-SAT...WHICH IS TYPICALLY A DRYING
DIRECTION LOCALLY. AT THE SURFACE...THE COLD FRONT WILL REMAIN OFF
THE COAST...WHILE HIGH PRESSURE BENEATH THE BAHAMAS RIDGE EXPANDS
WEST OVER THE ATLANTIC...DRIVING SW RETURN FLOW INTO THE AREA. THIS
SUGGESTS A FEW WARM AND SUNNY DAYS THU-SAT WITH TEMPS AROUND
SEASONABLE VALUES BOTH DURING THE DAY AND AT NIGHT. TYPICAL DIURNAL
SHOWERS/TSTMS CANNOT BE RULED OUT FRI/SAT...BUT COVERAGE WILL BE
ISOLATED AND WILL KEEP POP SILENT. BY SUNDAY THE MID-LEVEL FLOW
WEAKENS AS THE CANADIAN LOW PULLS OFF TO THE EAST...AND MORE
COVERAGE OF DIURNAL CONVECTION WILL BE POSSIBLE.
AS NOTED BY THE PREVIOUS FORECASTER...THERE IS ONE CAVEAT TO THE
EXTENDED...AND THAT INVOLVES THE RIPPLING OF THE COLD FRONT
OFFSHORE. AS WEAK IMPULSES TRAVERSE THROUGH THE LONGWAVE TROUGH
ALOFT...THEY WILL TRY TO PULL THIS FRONT BACK TOWARDS THE COAST
FRI/SAT/SUN. IF THIS OCCURS IT COULD ENHANCE PRECIP POTENTIAL LATE
IN THE WEEK AND ON THE WEEKEND...BUT ATTM WITH THE WESTERLY FLOW
EXPECTED TO BE PRETTY STRONG...WILL OPT FOR THE DRIER SOLUTION
DURING THIS PERIOD.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...PERIODS OF MVFR/IFR THROUGH EARLY MONDAY MORNING AS LOW
CIGS...AREAS OF FOG...AND ISOLATED LIGHT SHRA MOVE ACROSS PORTIONS
OF THE AREA. VFR/MVFR ANTICIPATED ON MONDAY WITH SHRA/TSRA.
LATEST RADAR DEPICTS A FEW LIGHT SHOWERS MOVING ABOUT THE FORECAST
AREA...BUT ARE NOT IMPACTING ANY TAF SITES ATTM. ANTICIPATE LOW CIGS
AND AREAS OF FOG TO CREATE MVFR/IFR THROUGH THE OVERNIGHT
HOURS...WITH MAINLY MVFR ALONG THE COAST WITH IFR INLAND. EXPECT
WINDS OVERNIGHT TO BE MAINLY EASTERLY AOB 10 KTS. AFTER
DAYBREAK...EXPECT SHOWERS WITH ISOLATED THUNDERSTORMS THROUGHOUT THE
DAY...CREATING MVFR CONDITIONS AT TIMES THROUGH THE END OF THE VALID
TAF PERIOD DUE TO PERIODS OF LOW CIGS AND LOW VSBYS DUE TO HEAVY
DOWNPOURS AND PATCHY FOG. WINDS WILL BE EAST-SOUTHEAST AOB 10 KTS.
TOWARDS THE END OF THE PERIOD...SHRA/TSRA WILL TAPER OFF AND WINDS
WILL BECOME LIGHT...WITH MVFR POSSIBLE.
EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHRA/TSRA ALONG WITH TEMPO
MVFR CONDITIONS THROUGH TUESDAY AS A FRONT REMAINS STALLED IN THE
AREA. IMPROVING CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6 AM MONDAY...A BUMPY 3-4 FEET EXPECTED TODAY AS WINDS
INCREASE DUE TO THE SLOW APPROACH OF A COASTAL LOW OFF OF SC EARLY
THIS MORNING. THIS FEATURE WILL INTERACT WITH A HIGH PRESSURE
WEDGE INLAND TODAY AND TONIGHT. A CAUTION STATEMENT CANNOT BE
RULED OUT LATER TODAY OR TONIGHT BUT RIGHT NOW IT LOOKS LIKE WE
MAY NOT NEED ONE. TSTMS AND TORRENTIAL SHOWERS ARE POSSIBLE ON THE
WATERS AND THIS WILL REDUCE VSBYS LESS THAN 1 NM AT TIMES.
MARINERS SHOULD CONSIDER GETTING A RADAR BRIEFING OR LOOK BEFORE
HEADING OUT TODAY OR TONIGHT. SEA SPECTRUM WILL BE COMPRISED OF E
WAVES 3 FEET EVERY 3-5 SECONDS...AND SE WAVES 1-1.5 FEET IN 8-10
SECOND INTERVALS. ONSHORE WINDS WILL PERSIST THROUGH DAYBREAK
TUESDAY BUT WIND SPEEDS SHOULD DROP-OFF AS THE LOW WEAKENS BUT
DOES REMAIN OVERHEAD OF THE LOCAL WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM MONDAY...TWO DISTINCT FRONTS WILL MOVE ACROSS THE
WATERS DURING THE SHORT TERM. THE FIRST...A WARM FRONT...WILL LIFT
NORTH OVER THE WATERS EARLY TUESDAY...CREATING WINDS THAT WILL
INCREASE FROM THE S/SW TO 10-15 KTS MUCH OF TUESDAY. THESE WINDS
WILL CONTINUE INTO WEDNESDAY AHEAD OF A COLD FRONT WHICH WILL CROSS
THE WATERS BY EARLY THURSDAY...TURNING WINDS TO THE NORTH AROUND 10
KTS AT THE END OF THE PERIOD. ALTHOUGH S/SW WINDS WILL BE FEATURED
THROUGH THE MAJORITY OF THE PERIOD...THE SEA SPECTRUM WILL BECOME
CONFUSED AT TIMES WITH THE WIND SHIFTS AND LACK OF SIGNIFICANT
SWELL. HIGHEST WAVES WILL BE LATE TUESDAY AND MUCH OF WEDNESDAY WHEN
THEY WILL REACH 3-4 FT. OTHERWISE...EXPECT 2-3 FT SEAS.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 330 AM MONDAY...COLD FRONT MOVING OFFSHORE AT THE START OF THE
PERIOD WILL LEAVE NORTH WINDS AROUND 10 KTS IN ITS WAKE...BECOMING
E/NE THROUGH THE AFTN. THE PRESSURE GRADIENT THEN BECOMES QUITE
DIFFUSE THROUGH THE END OF THE WEEK AS THE FRONT STALLS OFFSHORE.
THIS WILL DRIVE ONLY LIGHT AND VARIABLE WINDS MUCH OF FRIDAY. THE
OFFSHORE WINDS...FOLLOWED BY VERY LIGHT WINDS...WILL KEEP SEAS TO
LOW AMPLITUDE BOTH DAYS...1-3 FT THURSDAY AND 1-2 FT ON FRIDAY.
&&
.TIDES/COASTAL FLOODING...
AS OF 6 AM MONDAY...STRONG ASTRONOMICAL TIDES WITH THIS WANING
FULL MOON CYCLE WILL REQUIRE ANOTHER COASTAL FLOOD ADVISORY WITH
THIS EVENINGS HIGH TIDE FOR ALL BEACHES AND THE LOWER CAPE FEAR
RIVER SIMILAR TO THE LAST 2 EVENINGS...BUT LIKELY A FEW INCHES
LOWER ON THE PEAK WATER LEVELS. ELEVATED LEVELS WILL BE OBSERVED
ALONG THE BANKS OF THE ICW AS WELL DURING HIGH TIDE. THE LOWER
CAPE FEAR RIVER WILL EXPERIENCE MINOR COASTAL FLOODING INCLUDING
LOCALIZED SPOTS IN DOWNTOWN WILMINGTON. PREDICTED TIDE LEVELS SHOW
WE MAY NOT NEED THE ADVISORY TUESDAY NIGHT FOR THE BEACHES...BUT
THE LOWER CAPE FEAR WILL NEED AN ADVISORY FOR A FEW DAYS OF THE
NIGHT-TIME HIGH TIDE CYCLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH THIS EVENING FOR SCZ017-023-024-032-033-
039-053>056.
COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
SCZ054-056.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ087-096-099-105>110.
COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 1 AM EDT
TUESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW/MJC
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MJC/MRR
MARINE...MJC/JDW
TIDES/COASTAL FLOODING...MJC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
354 AM EDT MON AUG 11 2014
.SYNOPSIS...
A STALLED FRONT WILL WAVER NEAR THE AREA THROUGH
TUESDAY...CONTINUING THE CHANCE FOR PERIODS OF HEAVY RAINFALL IN
SHOWERS AND THUNDERSTORMS. A FLOOD WATCH IS IN EFFECT FOR THE
ENTIRE AREA TODAY. A STRONG COLD FRONT WILL CROSS THE AREA
OVERNIGHT WEDNESDAY...BRINGING DRIER CONDITIONS. SEASONABLE
WEATHER IS EXPECTED THURSDAY AND INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM MONDAY...A FLOOD WATCH IS POSTED FOR NE SC AND SE
NC DUE TO THE POTENTIAL ONCE AGAIN FOR SCATTERED TORRENTIAL RAINS
OVER SOGGY GROUND AND EVEN STANDING WATER AREAS ACROSS OUR ZONES.
SATELLITE SENSORS ARE REGISTERING A POOL OF DEEP COLUMN MOISTURE
IN EXCESS OF 2 INCH PRECIPITABLE WATER VALUE...ACROSS MOST OF THE
GULF STATES EXTENDING NE INTO SC AND COASTAL NC. AN EDDY IN THIS
POOL WILL WELL-UP NORTHWARD AS AN UPPER RIDGE AMPLIFIES ALONG THE
EASTERN SEABOARD LATER TODAY. IT APPEARS MOISTURE MAY IN FACT
DEEPEN FURTHER BY THIS AFTERNOON AND INTO EVENING.
DISCONCERTING IS THAT PROJECTED CELL MOTION TODAY MAY NOT EXCEED
10 KT IN THE HEAVY RAIN CORES. ALSO OF CONCERN IS A COASTAL LOW
OFFSHORE OF SC PRESENTLY THAT WILL BE DRAWN SLIGHTLY NORTHWARD
TODAY. THIS FEATURE WILL SHARPEN MOISTURE TRANSPORT IN THE LOW
LEVELS OFF THE BALMY SEA AS THE SYNOPTIC GRADIENT BECOMES A BIT
MORE PINCHED. THIS SFC-850 TRANSPORT MAY ALSO INDUCE ISENTROPIC
RAINS OVER OUR NORTHERN INTERIOR ZONES LATER TODAY...AND FOR THIS
REASON THE FLOOD WATCH IS POSTED FOR ALL ILM ZONES.
COVERAGE MAY REMAIN SCATTERED SUGGESTING LOCALIZED FLOODING BUT IT
COULD BE SIGNIFICANT IF TRAINING OR QUASI-STATIONARY CELL MOTION
DEVELOPS LATER TODAY AS THE 4KM WRF AND HRRR NEAR TERM MODELS ARE
HINTING AT. ANY PARTIAL SUNSHINE TODAY WILL ONLY BOOST SURFACE
BASED CONVECTIVE ENERGY IN NEARLY A PURE TROPICAL AIR MASS.
THE CLOUDS AND ANTICIPATED RAIN WITH A FEW PEEKS OF SUNSHINE IN
SPOTS SHOULD BRING MAXIMUMS INTO THE LOW AND MIDDLE 80S TODAY.
MINIMUMS 70S TONIGHT AND MILDEST COAST ALTHOUGH ADMITTEDLY THE
CLOUDS AND POTENTIAL RAINFALL NAY BRING NON-UNIFORMITY TO LOWS
EARLY MONDAY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 330 AM MONDAY...FINALLY SOME SEASONABLE TEMPERATURES FOR THE
SHORT TERM AS A DRYING TREND COMMENCES BEGINNING WEDNESDAY.
TUESDAY IS EXPECTED TO BE THE LAST DAY OF WIDESPREAD PRECIP AND COOL
TEMPERATURES. SHARP AND STRONG 500MB TROUGH WILL BE MOVING ACROSS
THE GREAT LAKES...LEAVING LOWERED MID-LEVEL HEIGHTS BUT WITH S/SW
FLOW THROUGH THE COLUMN. THIS CREATES A SITUATION WITH PWATS
REMAINING WELL ABOVE 2 INCHES...AND AS UPPER IMPULSES ROTATE THROUGH
THE AFOREMENTIONED TROUGH...PRECIP WILL OCCUR ACROSS THE AREA.
ALTHOUGH THE STALLED BOUNDARY FROM THIS PAST WKND WILL LIKELY LIFT
NORTH DURING TUESDAY...ANY STRONG WAA BEHIND IT WILL BE TEMPERED BY
CLOUDS AND CONVECTION...SO HIGHS WILL STAY JUST BELOW
NORMAL...ALTHOUGH WARMER THAN THE PREVIOUS FEW DAYS. EXPECT HIGHS IN
THE UPPER 80S...MID 80S FAR NORTH. MOS P-NUMBERS ARE IN THE HIGH
CHC/LIKELY RANGE FOR TUESDAY...AND THIS MATCHES INHERITED WELL. THUS
WILL MAKE MINIMAL CHANGES TO POP FOR TUESDAY...BUT WILL RAMP POP
DOWN QUICKLY TUESDAY NIGHT AS MID-LEVEL DRYING BEGINS.
HOWEVER...SOME PLACES COULD ONCE AGAIN SEE PERIODS OF HEAVY RAINFALL
THE FIRST HALF OF TUESDAY. LOWS WILL FALL ONLY INTO THE MID 70S
THANKS TO CONTINUED WARM SURFACE WINDS.
WEDNESDAY LOOKS TO BE A WARM DAY...ABOVE NORMAL ACROSS THE
AREA...THANKS TO ENHANCED RETURN FLOW AHEAD OF A COLD FRONT AND DRY
WESTERLY MID-LEVEL FLOW. CHC FOR CONVECTION WEDNESDAY WILL BE QUITE
MINIMAL AS PWATS DROP BELOW 1.5 INCHES EVEN AHEAD OF THE COLD
FRONT...AND THEN TO LESS THAN 1 INCH BEHIND IT WED NIGHT. BEST
CHANCE FOR ANY SHOWERS WILL BE EARLY WEDNESDAY ALONG THE
COAST...BEFORE CLEARING OCCURS DURING THE AFTN/EVE...AND THE SUN IS
EXPECTED TO SHINE ON WEDNESDAY! TEMPS WILL WARM INTO THE LOW 90S
AWAY FROM THE BEACHES...WITH LOWS DROPPING TO A DEGREE OR TWO EITHER
SIDE OF 70.
FOR THOSE HOPING TO VIEW TO ANNUAL PERSEID METEOR SHOWER...ALTHOUGH
THE PEAK IS TUESDAY NIGHT/WEDNESDAY MORNING...THE BEST CHANCE FOR
VIEWING LOCALLY WILL BE WEDNESDAY NIGHT/THURSDAY MORNING AS THE SKY
WILL FINALLY CLEAR. VIEWERS WILL STILL NEED TO DEAL WITH A NEARLY
FULL MOON...BUT METEORS SHOULD BE VISIBLE WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 330 AM MONDAY...A PERIOD OF ACTUAL SUMMER-LIKE WEATHER
EXPECTED FOR THE END OF THE WEEK AND INTO THE WEEKEND AS WESTERLY
MID-LEVEL FLOW DEVELOPS AND PERSISTS THROUGH THE PERIOD.
COLD FRONT WILL BE OFFSHORE THURSDAY MORNING...AND WILL BECOME
STALLED OFFSHORE THROUGH THE PERIOD. ALOFT...THE CAROLINAS WILL BE
ENTRENCHED BETWEEN A DEEP UPPER LOW OVER SOUTHEAST CANADA...AND A
HIGH PRESSURE EXPANDING ACROSS THE BAHAMAS. THIS LEAVES PINCHED
MID-LEVEL FLOW FROM THE WEST THU-SAT...WHICH IS TYPICALLY A DRYING
DIRECTION LOCALLY. AT THE SURFACE...THE COLD FRONT WILL REMAIN OFF
THE COAST...WHILE HIGH PRESSURE BENEATH THE BAHAMAS RIDGE EXPANDS
WEST OVER THE ATLANTIC...DRIVING SW RETURN FLOW INTO THE AREA. THIS
SUGGESTS A FEW WARM AND SUNNY DAYS THU-SAT WITH TEMPS AROUND
SEASONABLE VALUES BOTH DURING THE DAY AND AT NIGHT. TYPICAL DIURNAL
SHOWERS/TSTMS CANNOT BE RULED OUT FRI/SAT...BUT COVERAGE WILL BE
ISOLATED AND WILL KEEP POP SILENT. BY SUNDAY THE MID-LEVEL FLOW
WEAKENS AS THE CANADIAN LOW PULLS OFF TO THE EAST...AND MORE
COVERAGE OF DIURNAL CONVECTION WILL BE POSSIBLE.
AS NOTED BY THE PREVIOUS FORECASTER...THERE IS ONE CAVEAT TO THE
EXTENDED...AND THAT INVOLVES THE RIPPLING OF THE COLD FRONT
OFFSHORE. AS WEAK IMPULSES TRAVERSE THROUGH THE LONGWAVE TROUGH
ALOFT...THEY WILL TRY TO PULL THIS FRONT BACK TOWARDS THE COAST
FRI/SAT/SUN. IF THIS OCCURS IT COULD ENHANCE PRECIP POTENTIAL LATE
IN THE WEEK AND ON THE WEEKEND...BUT ATTM WITH THE WESTERLY FLOW
EXPECTED TO BE PRETTY STRONG...WILL OPT FOR THE DRIER SOLUTION
DURING THIS PERIOD.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...PERIODS OF MVFR/IFR THROUGH EARLY MONDAY MORNING AS LOW
CIGS...AREAS OF FOG...AND ISOLATED LIGHT SHRA MOVE ACROSS PORTIONS
OF THE AREA. VFR/MVFR ANTICIPATED ON MONDAY WITH SHRA/TSRA.
LATEST RADAR DEPICTS A FEW LIGHT SHOWERS MOVING ABOUT THE FORECAST
AREA...BUT ARE NOT IMPACTING ANY TAF SITES ATTM. ANTICIPATE LOW CIGS
AND AREAS OF FOG TO CREATE MVFR/IFR THROUGH THE OVERNIGHT
HOURS...WITH MAINLY MVFR ALONG THE COAST WITH IFR INLAND. EXPECT
WINDS OVERNIGHT TO BE MAINLY EASTERLY AOB 10 KTS. AFTER
DAYBREAK...EXPECT SHOWERS WITH ISOLATED THUNDERSTORMS THROUGHOUT THE
DAY...CREATING MVFR CONDITIONS AT TIMES THROUGH THE END OF THE VALID
TAF PERIOD DUE TO PERIODS OF LOW CIGS AND LOW VSBYS DUE TO HEAVY
DOWNPOURS AND PATCHY FOG. WINDS WILL BE EAST-SOUTHEAST AOB 10 KTS.
TOWARDS THE END OF THE PERIOD...SHRA/TSRA WILL TAPER OFF AND WINDS
WILL BECOME LIGHT...WITH MVFR POSSIBLE.
EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHRA/TSRA ALONG WITH TEMPO
MVFR CONDITIONS THROUGH TUESDAY AS A FRONT REMAINS STALLED IN THE
AREA. IMPROVING CONDITIONS WEDNESDAY. VFR THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM MONDAY...A BUMPY 3-4 FEET EXPECTED TODAY AS WINDS
INCREASE DUE TO THE SLOW APPROACH OF A COASTAL LOW OFF OF SC EARLY
THIS MORNING. A CAUTION STATEMENT CANNOT BE RULED OUT LATER TODAY
OR TONIGHT BUT RIGHT NOW IT LOOKS LIKE WE MAY NOT NEED ONE. TSTMS
AND TORRENTIAL SHOWERS ARE POSSIBLE ON THE WATERS AND THIS WILL
REDUCE VSBYS LESS THAN 1 NM AT TIMES. MARINERS SHOULD CONSIDER
GETTING A RADAR BRIEFING OR LOOK BEFORE HEADING OUT TODAY OR
TONIGHT. SEA SPECTRUM WILL BE COMPRISED OF E WAVES 3 FEET EVERY
3-5 SECONDS...AND SE WAVES 1-1.5 FEET IN 8-10 SECOND INTERVALS.
ONSHORE WINDS WILL PERSIST THROUGH DAYBREAK TUESDAY BUT WIND
SPEEDS SHOULD DROP-OFF AS THE LOW WEAKENS BUT DOES REMAIN OVERHEAD
OF THE LOCAL WATERS.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM MONDAY...TWO DISTINCT FRONTS WILL MOVE ACROSS THE
WATERS DURING THE SHORT TERM. THE FIRST...A WARM FRONT...WILL LIFT
NORTH OVER THE WATERS EARLY TUESDAY...CREATING WINDS THAT WILL
INCREASE FROM THE S/SW TO 10-15 KTS MUCH OF TUESDAY. THESE WINDS
WILL CONTINUE INTO WEDNESDAY AHEAD OF A COLD FRONT WHICH WILL CROSS
THE WATERS BY EARLY THURSDAY...TURNING WINDS TO THE NORTH AROUND 10
KTS AT THE END OF THE PERIOD. ALTHOUGH S/SW WINDS WILL BE FEATURED
THROUGH THE MAJORITY OF THE PERIOD...THE SEA SPECTRUM WILL BECOME
CONFUSED AT TIMES WITH THE WIND SHIFTS AND LACK OF SIGNIFICANT
SWELL. HIGHEST WAVES WILL BE LATE TUESDAY AND MUCH OF WEDNESDAY WHEN
THEY WILL REACH 3-4 FT. OTHERWISE...EXPECT 2-3 FT SEAS.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 330 AM MONDAY...COLD FRONT MOVING OFFSHORE AT THE START OF THE
PERIOD WILL LEAVE NORTH WINDS AROUND 10 KTS IN ITS WAKE...BECOMING
E/NE THROUGH THE AFTN. THE PRESSURE GRADIENT THEN BECOMES QUITE
DIFFUSE THROUGH THE END OF THE WEEK AS THE FRONT STALLS OFFSHORE.
THIS WILL DRIVE ONLY LIGHT AND VARIABLE WINDS MUCH OF FRIDAY. THE
OFFSHORE WINDS...FOLLOWED BY VERY LIGHT WINDS...WILL KEEP SEAS TO
LOW AMPLITUDE BOTH DAYS...1-3 FT THURSDAY AND 1-2 FT ON FRIDAY.
&&
.TIDES/COASTAL FLOODING...
AS OF 345 AM MONDAY...STRONG ASTRONOMICAL TIDES WITH THIS WANING
FULL MOON CYCLE WILL REQUIRE ANOTHER COASTAL FLOOD ADVISORY WITH
THIS EVENINGS HIGH TIDE FOR ALL BEACHES AND THE LOWER CAPE FEAR
RIVER SIMILAR TO THE LAST 2 EVENINGS...BUT LIKELY A FEW INCHES
LOWER ON THE PEAK WATER LEVELS. ELEVATED LEVELS WILL BE OBSERVED
ALONG THE BANKS OF THE ICW AS WELL DURING HIGH TIDE. THE LOWER
CAPE FEAR RIVER WILL EXPERIENCE MINOR COASTAL FLOODING INCLUDING
LOCALIZED SPOTS IN DOWNTOWN WILMINGTON. PREDICTED TIDE LEVELS SHOW
WE MAY NOT NEED THE ADVISORY TUESDAY NIGHT FOR THE BEACHES...BUT
THE LOWER CAPE FEAR WILL NEED AN ADVISORY FOR A FEW DAYS OF THE
NIGHT-TIME HIGH TIDE CYCLE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH THIS EVENING FOR SCZ017-023-024-032-033-
039-053>056.
COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
SCZ054-056.
NC...FLOOD WATCH THROUGH THIS EVENING FOR NCZ087-096-099-105>110.
COASTAL FLOOD ADVISORY FROM 8 PM TO 11 PM EDT THIS EVENING FOR
NCZ106-108-110.
COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 1 AM EDT
TUESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...MJC
MARINE...MJC/JDW
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 AM EDT MON AUG 11 2014
.SYNOPSIS...A RIDGE OF HIGH PRESSURE EXTENDING INTO CENTRAL NC FROM
THE NORTHEAST TODAY WILL WEAKEN TONIGHT...ALLOWING A STATIONARY FRONT
OVER SOUTH CAROLINA TO SLOWLY LIFT NORTH AS A WARM FRONT ON TUESDAY.
A COLD FRONT WILL THEN MOVE INTO THE AREA FROM THE NORTHWEST ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM MONDAY...
A 1021 MB SURFACE HIGH CENTERED OVER NEW ENGLAND CONTINUES TO EXTEND
INTO THE CAROLINAS...WHILE A FRONTAL ZONE IS STATIONARY NEAR THE
SAVANNAH RIVER BASIN. A MOIST SOUTHERLY FLOW...ALBEIT LIGHT..WAS
OBSERVED THROUGH 700MB ON THE 00Z RAOBS...AND WEAK ISENTROPIC LIFT
CONTINUES TO SUPPORT SOME PATCHES OF LIGHT RAIN...MAINLY ACROSS THE
SOUTHERN PIEDMONT EARLY THIS MORNING. MOST NWP SHOWS THE FOCUS OF
ISENTROPIC LIFT SHIFTING TOWARD THE WESTER PIEDMONT THIS
MORNING...THEN OFF TO THE NORTH LATER THIS AFTERNOON/EVENING AS THE
FLOW ABOVE 925MB VEERS AROUND TO MORE SOUTHERLY AHEAD OF A SYSTEM
MOVING INTO THE MIDWEST. WINDS BELOW 925MB SHOULD REMAIN OUT OF THE
EAST AS A SECONDARY WAVE OF LOW PRESSURE MIGRATES ALONG THE THE
SURFACE FRONT..SO AT LEAST SOME WEAK WARM ADVECTION AND A CHANCE OF
RAIN WILL CONTINUE THROUGH TONIGHT. ANY APPRECIABLE INSTABILITY
WILL STAY TO OUR SOUTH WITH THE FRONTAL ZONE...THOUGH A LITTLE
BETTER HEATING OVER THE SOUTHEAST MAY ALLOW SOME PRECIP TO BECOME
MORE SHOWERY LATER THIS AFTERNOON. MODEL QPF IS HIGHEST FROM THE
SANDHILLS TO THE WESTERN PIEDMONT...GENERALLY SHOWING AROUND A
QUARTER TO A THIRD OF AN INCH IN SPOTS TODAY. AREAS TO THE
NORTHEAST OF THE TRIANGLE SHOULD SEE MUCH LESS. CONERNING FLOOD
POTENTIAL...THERE HAVE BEEN SOME HEAVY RAINFALL TOTALS OVER THE PAST
COUPLE OF DAYS...BUT AT THIS TIME IT DOESNT APPEAR RAINFALL RATES
WOULD SUPPORT A FLASH FLOOD WATCH FOR TODAY. THAT BEING SAID...IF
SOME OF THE PRECIP BECOMES A LITTLE MORE CONVECTIVE IN NATURE ACROSS
THE SOUTHEAST CWA...THEN SOME MINOR FLOODING MAY BE POSSIBLE.
HEATING WILL AGAIN BE LIMITED OVER THE NORTHWEST PIEDMONT DUE TO
PERSISTENT...SO WILL GO WITH A TEMP RANGE SIMILAR TO THAT OBSERVED
ON SUNDAY WITH LOWER 70S NORTHWEST TO AROUND 80 IN THE EAST. LOWS
TONIGHT IN THE UPPER 60S AND LOWER 70S
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 330 AM MONDAY...
THE SURFACE HIGH AIDING THE COLD AIR DAMMING AIRMASS OVER THE AREA
WILL RETREAT BY TUESDAY MORNING...AND A SOUTHWESTERLY WIND WILL
DEVELOP AHEAD OF A SHORTWAVE CROSSING THE MIDWEST AND THE ATTENDANT
COLD FRONT APPROACHING FROM THE WEST. WEAK HEIGHT FALLS AND
INCREASINGLY CONFLUENT FLOW OUT AHEAD FO THE FRONT WILL SUPPORT
SCATTERED SHOWERS AND STORMS AS PW INCREASES BACK TOWARD 2 INCHES.
DEEP LAYER SHEAR...WHILE NOT OVERLY IMPRESSIVE...IS FORECAST TO
INCREASE TOWARD 30KT AS A JET STRENGTHENS ALONG THE APPALACHIANS OUT
AHEAD OF THE UPPER TROUGH AXIS. THIS BIGGEST QUESTION WILL BE HOW
MUCH INSTABILITY DEVELOPS DUE TO WEAK LAPSE RATES AND LINGERING
STRATUS IN THE MORNING. NOT ...SREF PROBABILITIES OF MLCAPE
EXCEEDING 1000 J/KG ARE GREATEST OVER THE COASTAL PLAIN WHERE
HEATING WILL BE STRONGEST....WHICH IS DISPLACED FROM THE STRONGEST
SHEAR. THUS...WHILE CONVECTION WILL BE MORE PREVALENT THAT IT HAS
BEEN IN THE PAST FEW DAYS...THE POTENTIAL FOR SEVRE WEATHER APPEARS
LIMITED. WILL RAISE TEMPS A BIT OVER THE SOUTHEAST AND EAST WHERE
FULL HEATING SHOULD BE REALIZED (IF NOT EVERYWHERE)...WITH HIGHS
RANGING FROM THE LOWER 80S NORTHWEST TO UPPER 80S SOUTHEAST.
DRIER AIR WILL BEGIN TO FILTER IN LATE TUESDAY NIGHT...ESPECIALLY
INT HE MID-LEVELS.. AS A NORTHWEST WIND DEVELOPS BEHIND THE COLD
FRONT. WILL MAINTAIN A SLIGHT CHANCE TO CHANCER POP OVER THE EAST
OVERNIGHT WITH LOWS IN THE MID 60S TO AROUND 70.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...
DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE GUIDANCE ARE IN
RELATIVELY GOOD AGREEMENT THIS MORNING...WHOSE SOLUTIONS ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING UPPER
LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS DURING DAYS 3-7.
A PRIMARY SFC COLD FRONT...ONE ACCOMPANYING A LEAD SHORTWAVE TROUGH
FORECAST TO AMPLIFY FROM THE NORTHERN PLAINS THIS MORNING TO THE
MIDDLE ATLANTIC COAST BY EARLY WED...WILL BE NEARING THE NC COAST
WED MORNING...WHILE A SECONDARY ONE IS FORECAST TO SETTLE SSE ACROSS
CENTRAL NC WED EVE-NIGHT. DRIER AND MORE STABLE AIR AT THE SFC AND
ALOFT...THE FORMER EXACERBATED BY 10-15 KTS OF WNW DOWNSLOPE H85
FLOW...WILL RESULT IN DRY; WARM; AND NOTICEABLY BREEZY CONDITIONS
WED...WITH THE MORE APPRECIABLE LOW LEVEL CAA TRAILING THE SECONDARY
FRONT WED NIGHT. HIGHS GENERALLY IN THE MIDDLE TO UPPER 80S...WITH
GENERALLY WESTERLY WINDS OF 10-15 MPH GUSTING TO AROUND 20 MPH.
FOLLOWING CANADIAN HIGH PRESSURE AND ASSOCIATED LOW LEVEL
THICKNESSES WED NIGHT WILL BE SUPPORTIVE OF LOWS MOSTLY IN THE UPPER
50S TO LOWER 60S...WITH FURTHER COOLING POTENTIAL INTO THE LOW-MID
50S WHERE/IF DECOUPLING (SFC CALM) OCCURS...MOST LIKELY IN SHELTERED
WESTERN PIEDMONT LOCATIONS.
THU THROUGH SUN: THE LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE
MID MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A
REINFORCING COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS
THE OH AND TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC
TROUGHING IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW
ALOFT AND ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE
CENTER OF THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH THE WEEKEND. MOISTURE...AT THE SFC AND THROUGH
A DEEP LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE
DRYNESS WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND
PRECIPITABLE WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY
SLOWLY INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-
INDUCED CONVECTION...THROUGH THE WKND. H85 TEMPS IN THE 14-16C
RANGE...SHOULD SUPPORT TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW
NORMAL...COOLEST MID-LATE WEEK.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 150 AM MONDAY...
A WEAK BUT FAIRLY DEEP SOUTHEASTERLY FLOW CONTINUES OVER CENTRAL NC
THIS MORNING. POCKETS OF LIGHT RAIN AND DRIZZLE OVER THE SOUTHERN
PIEDMONT HAVE BEEN FAIRLY LIGHT AND DRIFTING VERY SLOWLY TO THE
NORTH. A BRIEF PERIOD OF LIGHT RAIN IS POSSIBLE AT KFAY THROUGH 08Z
OR 09Z...WHILE THE FOCUS FOR RAIN OR DRIZZLE SHOULD SHIFT TOWARD
KINT/KGSO BY 12Z. LOW CLOUDS WILL CONTINUE TO BE FAVORED OVER
WESTERN PORTIONS OF THE AREA...WITH MVFR CEILINGS LIKELY LOWERING TO
AT LEAST IFR AT KGSO/KINT THIS MORNING. ITS A LITTLE UNCLEAR HOW
FAR EAST THE SUB-VFR CEILINGS WILL EXPAND TO THE EAST...SO
CONFIDENCE IN MVFR OR IFR CEILINGS AT KRDU IS LOWER. HOWEVER...THE
MOST RECENT RAP AND HRRR SHOW LESS STRATUS AT KRDU...KRWI AND
KFAY...WITH CEILINGS HOVERING AT HIGH END MVFR OR ABOVE. SUB-VFR
CEILINGS ARE THEN LIKELY TO RETURN TONIGHT.
OUTLOOK.... LOW CEILINGS SHOULD HANG AROUND EARLY TUESDAY AND THEN
SCATTER AND LIGHT AS A SOUTHWESTERLY WIND DEVELOPS ON TUESDAY AHEAD
OF AN APPROACHING COLD FRONT. A FEW SHOWERS AND STORMS WILL BE
POSSIBLE TUESDAY AFTERNOON...WITH DRIER CONDITIONS EXPECTED BEHIND
THE FRONT ONCE IT CROSSES THE AREA ON WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
310 AM EDT MON AUG 11 2014
.SYNOPSIS...A RIDGE OF HIGH PRESSURE EXTENDING INTO CENTRAL NC FROM
THE NORTHEAST TODAY WILL WEAKEN TONIGHT...ALLOWING A STATIONARY FRONT
OVER SOUTH CAROLINA TO SLOWLY LIFT NORTH AS A WARM FRONT ON TUESDAY.
A COLD FRONT WILL THEN MOVE INTO THE AREA FROM THE NORTHWEST ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM MONDAY...
A 1021 MB SURFACE HIGH CENTERED OVER NEW ENGLAND CONTINUES TO EXTEND
INTO THE CAROLINAS...WHILE A FRONTAL ZONE IS STATIONARY NEAR THE
SAVANNAH RIVER BASIN. A MOIST SOUTHERLY FLOW...ALBEIT LIGHT..WAS
OBSERVED THROUGH 700MB ON THE 00Z RAOBS...AND WEAK ISENTROPIC LIFT
CONTINUES TO SUPPORT SOME PATCHES OF LIGHT RAIN...MAINLY ACROSS THE
SOUTHERN PIEDMONT EARLY THIS MORNING. MOST NWP SHOWS THE FOCUS OF
ISENTROPIC LIFT SHIFTING TOWARD THE WESTER PIEDMONT THIS
MORNING...THEN OFF TO THE NORTH LATER THIS AFTERNOON/EVENING AS THE
FLOW ABOVE 925MB VEERS AROUND TO MORE SOUTHERLY AHEAD OF A SYSTEM
MOVING INTO THE MIDWEST. WINDS BELOW 925MB SHOULD REMAIN OUT OF THE
EAST AS A SECONDARY WAVE OF LOW PRESSURE MIGRATES ALONG THE THE
SURFACE FRONT..SO AT LEAST SOME WEAK WARM ADVECTION AND A CHANCE OF
RAIN WILL CONTINUE THROUGH TONIGHT. ANY APPRECIABLE INSTABILITY
WILL STAY TO OUR SOUTH WITH THE FRONTAL ZONE...THOUGH A LITTLE
BETTER HEATING OVER THE SOUTHEAST MAY ALLOW SOME PRECIP TO BECOME
MORE SHOWERY LATER THIS AFTERNOON. MODEL QPF IS HIGHEST FROM THE
SANDHILLS TO THE WESTERN PIEDMONT...GENERALLY SHOWING AROUND A
QUARTER TO A THIRD OF AN INCH IN SPOTS TODAY. AREAS TO THE
NORTHEAST OF THE TRIANGLE SHOULD SEE MUCH LESS. CONERNING FLOOD
POTENTIAL...THERE HAVE BEEN SOME HEAVY RAINFALL TOTALS OVER THE PAST
COUPLE OF DAYS...BUT AT THIS TIME IT DOESNT APPEAR RAINFALL RATES
WOULD SUPPORT A FLASH FLOOD WATCH FOR TODAY. THAT BEING SAID...IF
SOME OF THE PRECIP BECOMES A LITTLE MORE CONVECTIVE IN NATURE ACROSS
THE SOUTHEAST CWA...THEN SOME MINOR FLOODING MAY BE POSSIBLE.
HEATING WILL AGAIN BE LIMITED OVER THE NORTHWEST PIEDMONT DUE TO
PERSISTENT...SO WILL GO WITH A TEMP RANGE SIMILAR TO THAT OBSERVED
ON SUNDAY WITH LOWER 70S NORTHWEST TO AROUND 80 IN THE EAST. LOWS
TONIGHT IN THE UPPER 60S AND LOWER 70S
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 300 PM SUNDAY...
THE GFS FORECASTS CONTINUED...GRADUAL 850MB THETA-E ADVECTION EAST
ACROSS THE REST OF CENTRAL NORTH CAROLINA...AND AS THE RIDGE AXIS
ALOFT MOVES EAST...WEAKLY DIFFLUENT FLOW ALOFT OCCURS INTO MONDAY
NIGHT. OVERALL LIFT IS NOT VERY STRONG...BUT SOME IS FORECAST MONDAY
AND INTO MONDAY EVENING BEFORE THE MODEST LIFT IS FORECAST TO WEAKEN
OVERNIGHT MONDAY. DECENT MEAN MOISTURE IS IN PLACE OVER THE AREA...
AND THE MOISTURE ADVECTION AND THE WEAK DIFFLUENT FLOW ALONG WITH A
SHORTWAVE OR TWO FORECAST TO MOVE THROUGH CENTRAL NORTH CAROLINA IN
THE MID-LEVELS MONDAY AFTERNOON AND AGAIN MONDAY NIGHT ALL RESULT IN
THE LIKELIHOOD OF SHOWERS IN MOST PLACES WEST OF INTERSTATE 95
MONDAY AND MONDAY EVENING FOLLOWED BY JUST A CHANCE OF RAIN
OVERNIGHT MONDAY AS THE GUIDANCE SUGGESTS AN INCREASE IN SUBSIDENCE
AND LOWER CHANCES. ANTICIPATING AMPLE CLOUD COVER...HAVE FORECAST
HIGHS FOR MOST LOCATIONS A SOLID CATEGORY BELOW THE COOLER MET MOS
GUIDANCE...THOUGH IT WILL BE NOTED THAT THE HIGHS FORECAST FOR
MONDAY...ESPECIALLY IN THE NORTHWEST PIEDMONT ACROSS THE NORTHERN
COASTAL PLAIN...ARE ACTUALLY A CATEGORY HIGHER THAN THE BIAS
CORRECTED MOS GUIDANCE TEMPERATURES. GIVEN THE COOLER
TEMPERATURES... THE CURRENT THINKING IS THAT INSTABILITY AND LIFT
SHOULD PRECLUDE THUNDER...ALTHOUGH IF TEMPERATURES SOMEHOW DO GET
CLOSE TO THE WARMER MOS GUIDANCE VALUES...A THUNDERSTORM OR TWO WILL
BE POSSIBLE. WITH THE SURFACE FRONT ANTICIPATED TO START MOVING
NORTH AS SURFACE HIGH PRESSURE RETREATS...OVERNIGHT LOWS THROUGHOUT
CENTRAL NORTH CAROLINA SHOULD BE WITHIN A DEGREE OR TWO OF 70.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...
TUESDAY AND TUESDAY NIGHT: AN UPPER LEVEL LOW WILL TRAVERSE THE
GREAT LAKES ON TUESDAY AND INTO WEDNESDAY...PUSHING THE UPPER LEVEL
RIDGE EAST AND OFF THE MID-ATLANTIC COAST. ALSO...THE SURFACE
LOW/SHORTWAVE WILL MOVE NE THROUGH THE CENTRAL GREAT LAKES AND INTO
CANADA WITH THE ATTENDANT COLD FRONT APPROACHING NC FROM THE WEST.
MEANWHILE...A SECONDARY LOW WILL DEVELOP ALONG THE SE U.S. COAST
EARLY TUESDAY INCREASING SOUTHWESTERLY FLOW...TEMPERATURE...AND
MOISTURE INTO MUCH OF THE STATE. THOUGH THERE IS STILL A BIT OF
UNCERTAINTY REGARDING THE WEDGE AND HOW LONG IT WILL LINGER...IT
APPEARS THAT THE COLD FRONT WILL MOVE THROUGH MUCH OF THE AREA
TUESDAY NIGHT...WITH SKIES BECOMING LESS CLOUDY AND DRY CONDITIONS
EXPECTED BEHIND IT. FOR NOW WILL KEEP THE CHANCE FOR SHOWERS AND
STORMS ACROSS THE AREA THROUGH MIDNIGHT WEDNESDAY...DECREASING
THEREAFTER. CONVECTIVE PARAMETERS ARE NOT TERRIBLY IMPRESSIVE...
CAPE OF ROUGHLY 500-1000 J/KG (HIGHEST IN THE SE) AND BULK SHEAR IN
THE 20-30 KT RANGE (BEST ACROSS THE NORTH). PW`S WILL CONTINUE TO BE
IN THE 1.5-2 INCH RANGE TUESDAY...DECREASING SIGNIFICANTLY BEHIND
THE FRONT TUESDAY NIGHT. THAT BEING SAID...CANNOT RULE OUT STRONG
STORMS ON TUESDAY...MAINLY IN THE EAST...BUT FOR NOW EXPECT THE MAIN
THREAT TO BE STORMS WITH HEAVY RAIN AHEAD OF THE FRONT. HIGHS MAINLY
IN THE LOW TO MID 80S. OVERNIGHT LOWS WILL DEPEND ON THE PROGRESSION
OF THE FRONT...BUT FOR NOW EXPECT MID 60S NW TO LOW 70S SE.
WEDNESDAY THROUGH SUNDAY: MODELS STILL SUGGEST THE FRONT WILL STALL
ACROSS CENTRAL NC ON WEDNESDAY...WITH LOWER TEMPS AND FEWER CLOUDS
ACROSS THE NW...HIGHS IN THE LOW TO MID 80S. THE FRONT SHOULD MAKE
ITS WAY THROUGH THE AREA WEDNESDAY NIGHT...RESULTING IN LOWS IN THE
UPPER 50S NW TO MID 60S SE. THE UPPER LEVEL LOW WILL REMAIN OVER SE
CANADA/NEW ENGLAND THROUGH THE WEEKEND...WITH THE TROUGH OVER THE
ATLANTIC COAST AND WEST/NORTHWEST FLOW OVER NC. A SURFACE LOW IS
EXPECTED TO LINGER ALONG THE SE ATLANTIC COAST THROUGH SUNDAY...
WITH HIGH PRESSURE TO THE NORTH RIDGING INTO THE AREA. WILL KEEP THE
FORECAST DRY THROUGH SUNDAY...ALTHOUGH IF RAIN SHOULD DEVELOP...
EXPECT IT TO BE MAINLY ALONG THE CAROLINA COAST WHERE IT BECOMES
INCREASINGLY POSSIBLE TOWARD THE END OF THE WEEKEND. HIGHS WILL BE
IN THE LOW TO MID 80S THROUGH THE WEEKEND...WITH LOWS GRADUALLY
INCREASING INTO THE MID TO UPPER 60S BY SATURDAY NIGHT.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 150 AM MONDAY...
A WEAK BUT FAIRLY DEEP SOUTHEASTERLY FLOW CONTINUES OVER CENTRAL NC
THIS MORNING. POCKETS OF LIGHT RAIN AND DRIZZLE OVER THE SOUTHERN
PIEDMONT HAVE BEEN FAIRLY LIGHT AND DRIFTING VERY SLOWLY TO THE
NORTH. A BRIEF PERIOD OF LIGHT RAIN IS POSSIBLE AT KFAY THROUGH 08Z
OR 09Z...WHILE THE FOCUS FOR RAIN OR DRIZZLE SHOULD SHIFT TOWARD
KINT/KGSO BY 12Z. LOW CLOUDS WILL CONTINUE TO BE FAVORED OVER
WESTERN PORTIONS OF THE AREA...WITH MVFR CEILINGS LIKELY LOWERING TO
AT LEAST IFR AT KGSO/KINT THIS MORNING. ITS A LITTLE UNCLEAR HOW
FAR EAST THE SUB-VFR CEILINGS WILL EXPAND TO THE EAST...SO
CONFIDENCE IN MVFR OR IFR CEILINGS AT KRDU IS LOWER. HOWEVER...THE
MOST RECENT RAP AND HRRR SHOW LESS STRATUS AT KRDU...KRWI AND
KFAY...WITH CEILINGS HOVERING AT HIGH END MVFR OR ABOVE. SUB-VFR
CEILINGS ARE THEN LIKELY TO RETURN TONIGHT.
OUTLOOK.... LOW CEILINGS SHOULD HANG AROUND EARLY TUESDAY AND THEN
SCATTER AND LIGHT AS A SOUTHWESTERLY WIND DEVELOPS ON TUESDAY AHEAD
OF AN APPROACHING COLD FRONT. A FEW SHOWERS AND STORMS WILL BE
POSSIBLE TUESDAY AFTERNOON...WITH DRIER CONDITIONS EXPECTED BEHIND
THE FRONT ONCE IT CROSSES THE AREA ON WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...DJF
LONG TERM...KCP
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
150 AM EDT MON AUG 11 2014
.SYNOPSIS...A RIDGE OF HIGH PRESSURE EXTENDING INTO CENTRAL NC FROM
THE NORTHEAST TODAY WILL WEAKEN TONIGHT...ALLOWING A STATIONARY FRONT
OVER SOUTH CAROLINA TO SLOWLY LIFT NORTH AS A WARM FRONT ON TUESDAY.
A COLD FRONT WILL THEN MOVE INTO THE AREA FROM THE NORTHWEST ON
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 955 PM SUNDAY...
SURFACE HIGH PRESSURE CONTINUES TO EXTEND SOUTHWESTWARD FROM THE MID-
ATLANTIC COAST INTO CENTRAL NC THIS EVENING... WITH A STATIONARY
FRONT LOCATED ACROSS SC AND GA. MOIST S TO SE FLOW ATOP THE COOL
STABLE LAYER IS HELPING TO SUPPORT SOME LIGHT TO AT TIME MODERATE
SHOWERS/RAIN ACROSS THE SANDHILLS AND WESTERN PIEDMONT. THE LATEST
HRRR SHOWS THIS ACTIVITY CONTINUING TO LIFT NORTH/NORTHWESTWARD...
AND GENERALLY TO THE NORTH AND WEST OF CENTRAL NC BY 06/07Z. STILL
THINK THAT WE WILL SEE SOME PATCHES OF LIGHT RAIN AND/OR DRIZZLE
OVERNIGHT THOUGH... ESPECIALLY ACROSS THE WESTERN HALF OF THE AREA.
CHANCES OF RAIN AND/OR DRIZZLE SHOULD BE THE LEAST ACROSS OUR
NORTHEAST CLOSER TO THE LOW LEVEL ANTICYCLONE... WHERE BOTH THE GFS
AND NAM WERE SHOWING SOME DRIER AIR AT 850 MB WORKING INTO OUR
NORTHEAST. LOW TEMPS TONIGHT ARE EXPECTED TO RANGE FROM THE MID 60S
NE TO AROUND 70 SOUTH AND SOUTHWEST.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 300 PM SUNDAY...
THE GFS FORECASTS CONTINUED...GRADUAL 850MB THETA-E ADVECTION EAST
ACROSS THE REST OF CENTRAL NORTH CAROLINA...AND AS THE RIDGE AXIS
ALOFT MOVES EAST...WEAKLY DIFFLUENT FLOW ALOFT OCCURS INTO MONDAY
NIGHT. OVERALL LIFT IS NOT VERY STRONG...BUT SOME IS FORECAST MONDAY
AND INTO MONDAY EVENING BEFORE THE MODEST LIFT IS FORECAST TO WEAKEN
OVERNIGHT MONDAY. DECENT MEAN MOISTURE IS IN PLACE OVER THE AREA...
AND THE MOISTURE ADVECTION AND THE WEAK DIFFLUENT FLOW ALONG WITH A
SHORTWAVE OR TWO FORECAST TO MOVE THROUGH CENTRAL NORTH CAROLINA IN
THE MID-LEVELS MONDAY AFTERNOON AND AGAIN MONDAY NIGHT ALL RESULT IN
THE LIKELIHOOD OF SHOWERS IN MOST PLACES WEST OF INTERSTATE 95
MONDAY AND MONDAY EVENING FOLLOWED BY JUST A CHANCE OF RAIN
OVERNIGHT MONDAY AS THE GUIDANCE SUGGESTS AN INCREASE IN SUBSIDENCE
AND LOWER CHANCES. ANTICIPATING AMPLE CLOUD COVER...HAVE FORECAST
HIGHS FOR MOST LOCATIONS A SOLID CATEGORY BELOW THE COOLER MET MOS
GUIDANCE...THOUGH IT WILL BE NOTED THAT THE HIGHS FORECAST FOR
MONDAY...ESPECIALLY IN THE NORTHWEST PIEDMONT ACROSS THE NORTHERN
COASTAL PLAIN...ARE ACTUALLY A CATEGORY HIGHER THAN THE BIAS
CORRECTED MOS GUIDANCE TEMPERATURES. GIVEN THE COOLER
TEMPERATURES... THE CURRENT THINKING IS THAT INSTABILITY AND LIFT
SHOULD PRECLUDE THUNDER...ALTHOUGH IF TEMPERATURES SOMEHOW DO GET
CLOSE TO THE WARMER MOS GUIDANCE VALUES...A THUNDERSTORM OR TWO WILL
BE POSSIBLE. WITH THE SURFACE FRONT ANTICIPATED TO START MOVING
NORTH AS SURFACE HIGH PRESSURE RETREATS...OVERNIGHT LOWS THROUGHOUT
CENTRAL NORTH CAROLINA SHOULD BE WITHIN A DEGREE OR TWO OF 70.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...
TUESDAY AND TUESDAY NIGHT: AN UPPER LEVEL LOW WILL TRAVERSE THE
GREAT LAKES ON TUESDAY AND INTO WEDNESDAY...PUSHING THE UPPER LEVEL
RIDGE EAST AND OFF THE MID-ATLANTIC COAST. ALSO...THE SURFACE
LOW/SHORTWAVE WILL MOVE NE THROUGH THE CENTRAL GREAT LAKES AND INTO
CANADA WITH THE ATTENDANT COLD FRONT APPROACHING NC FROM THE WEST.
MEANWHILE...A SECONDARY LOW WILL DEVELOP ALONG THE SE U.S. COAST
EARLY TUESDAY INCREASING SOUTHWESTERLY FLOW...TEMPERATURE...AND
MOISTURE INTO MUCH OF THE STATE. THOUGH THERE IS STILL A BIT OF
UNCERTAINTY REGARDING THE WEDGE AND HOW LONG IT WILL LINGER...IT
APPEARS THAT THE COLD FRONT WILL MOVE THROUGH MUCH OF THE AREA
TUESDAY NIGHT...WITH SKIES BECOMING LESS CLOUDY AND DRY CONDITIONS
EXPECTED BEHIND IT. FOR NOW WILL KEEP THE CHANCE FOR SHOWERS AND
STORMS ACROSS THE AREA THROUGH MIDNIGHT WEDNESDAY...DECREASING
THEREAFTER. CONVECTIVE PARAMETERS ARE NOT TERRIBLY IMPRESSIVE...
CAPE OF ROUGHLY 500-1000 J/KG (HIGHEST IN THE SE) AND BULK SHEAR IN
THE 20-30 KT RANGE (BEST ACROSS THE NORTH). PW`S WILL CONTINUE TO BE
IN THE 1.5-2 INCH RANGE TUESDAY...DECREASING SIGNIFICANTLY BEHIND
THE FRONT TUESDAY NIGHT. THAT BEING SAID...CANNOT RULE OUT STRONG
STORMS ON TUESDAY...MAINLY IN THE EAST...BUT FOR NOW EXPECT THE MAIN
THREAT TO BE STORMS WITH HEAVY RAIN AHEAD OF THE FRONT. HIGHS MAINLY
IN THE LOW TO MID 80S. OVERNIGHT LOWS WILL DEPEND ON THE PROGRESSION
OF THE FRONT...BUT FOR NOW EXPECT MID 60S NW TO LOW 70S SE.
WEDNESDAY THROUGH SUNDAY: MODELS STILL SUGGEST THE FRONT WILL STALL
ACROSS CENTRAL NC ON WEDNESDAY...WITH LOWER TEMPS AND FEWER CLOUDS
ACROSS THE NW...HIGHS IN THE LOW TO MID 80S. THE FRONT SHOULD MAKE
ITS WAY THROUGH THE AREA WEDNESDAY NIGHT...RESULTING IN LOWS IN THE
UPPER 50S NW TO MID 60S SE. THE UPPER LEVEL LOW WILL REMAIN OVER SE
CANADA/NEW ENGLAND THROUGH THE WEEKEND...WITH THE TROUGH OVER THE
ATLANTIC COAST AND WEST/NORTHWEST FLOW OVER NC. A SURFACE LOW IS
EXPECTED TO LINGER ALONG THE SE ATLANTIC COAST THROUGH SUNDAY...
WITH HIGH PRESSURE TO THE NORTH RIDGING INTO THE AREA. WILL KEEP THE
FORECAST DRY THROUGH SUNDAY...ALTHOUGH IF RAIN SHOULD DEVELOP...
EXPECT IT TO BE MAINLY ALONG THE CAROLINA COAST WHERE IT BECOMES
INCREASINGLY POSSIBLE TOWARD THE END OF THE WEEKEND. HIGHS WILL BE
IN THE LOW TO MID 80S THROUGH THE WEEKEND...WITH LOWS GRADUALLY
INCREASING INTO THE MID TO UPPER 60S BY SATURDAY NIGHT.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 150 AM MONDAY...
A WEAK BUT FAIRLY DEEP SOUTHEASTERLY FLOW CONTINUES OVER CENTRAL NC
THIS MORNING. POCKETS OF LIGHT RAIN AND DRIZZLE OVER THE SOUTHERN
PIEDMONT HAVE BEEN FAIRLY LIGHT AND DRIFTING VERY SLOWLY TO THE
NORTH. A BRIEF PERIOD OF LIGHT RAIN IS POSSIBLE AT KFAY THROUGH 08Z
OR 09Z...WHILE THE FOCUS FOR RAIN OR DRIZZLE SHOULD SHIFT TOWARD
KINT/KGSO BY 12Z. LOW CLOUDS WILL CONTINUE TO BE FAVORED OVER
WESTERN PORTIONS OF THE AREA...WITH MVFR CEILINGS LIKELY LOWERING TO
AT LEAST IFR AT KGSO/KINT THIS MORNING. ITS A LITTLE UNCLEAR HOW
FAR EAST THE SUB-VFR CEILINGS WILL EXPAND TO THE EAST...SO
CONFIDENCE IN MVFR OR IFR CEILINGS AT KRDU IS LOWER. HOWEVER...THE
MOST RECENT RAP AND HRRR SHOW LESS STRATUS AT KRDU...KRWI AND
KFAY...WITH CEILINGS HOVERING AT HIGH END MVFR OR ABOVE. SUB-VFR
CEILINGS ARE THEN LIKELY TO RETURN TONIGHT.
OUTLOOK.... LOW CEILINGS SHOULD HANG AROUND EARLY TUESDAY AND THEN
SCATTER AND LIGHT AS A SOUTHWESTERLY WIND DEVELOPS ON TUESDAY AHEAD
OF AN APPROACHING COLD FRONT. A FEW SHOWERS AND STORMS WILL BE
POSSIBLE TUESDAY AFTERNOON...WITH DRIER CONDITIONS EXPECTED BEHIND
THE FRONT ONCE IT CROSSES THE AREA ON WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BSD
SHORT TERM...DJF
LONG TERM...KCP
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1211 PM EDT MON AUG 11 2014
.SYNOPSIS...
LOW PRESSURE ACROSS EAST-CENTRAL INDIANA WILL DRIFT NORTHWARD
REACHING LAKE HURON BY TUESDAY MORNING. THIS WILL TAKE A WARM
FRONT NORTH ACROSS THE AREA TODAY AND A COLD FRONT TUESDAY. THE
LOW PRESSURE SYSTEM WILL CONTINUE TO MOVE SLOWLY NORTHEAST AND
EXTEND A TROUGH SOUTHWEST ACROSS THE REGION WEDNESDAY NIGHT INTO
THURSDAY. HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION FOR THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS AND THUNDERSTORMS WORKING NORTH INTO THE AREA WITH
ADDITIONAL SHOWERS/THUNDERSTORMS DEVELOPING OVERHEAD TODAY.
OVER THE NEXT COUPLE OF DAYS A BROAD UPPER TROUGH WILL ENCOMPASS
THE EASTERN GREAT LAKES AND NEW ENGLAND. LOW PRESSURE ACROSS EAST
CENTRAL INDIANA WILL MOVE NORTH TOWARD LAKE HURON TODAY. MOISTURE
LEVELS ARE HIGH AND RAINFALL RATES COULD POTENTIALLY BE WILL BE AS
WELL. PRECIPITABLE WATER VALUES WILL NEAR 2 INCHES BY THIS
AFTERNOON. AREA IN A SLIGHT RISK FOR EXCESSIVE RAINFALL.
SEVERE WEATHER THREAT IS POSSIBLE WITH THE WARM FRONT AS HODOGRAPHS
ANTICIPATE SOME SHEAR IS POSSIBLE ALONG THE FRONTAL BOUNDARY.
THEREFORE...IT IS POSSIBLE FOR A FEW STORMS TO BECOME SEVERE LATER
TODAY.
GUIDANCE IS REALLY STRUGGLING WITH TEMPERATURES OVER THE LAST FEW
RUNS WITH NO CONSISTENCY SO WILL BE LEANING TOWARD CURRENT FORECAST
WITH A SLIGHT TWEAK UPWARD A FEW DEGREES TO ACCOUNT FOR A SLIGHTLY
LATER ARRIVAL OF THE PRECIPITATION...ESPECIALLY IN THE EAST.
NO CHANGES MADE WITH THIS MIDDAY UPDATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DEEP DIGGING UPPER LEVEL TROUGH DIVES INTO THE EASTERN UNITED STATES
TONIGHT AND THIS HELPS TO ENHANCE THE DEEPENING SURFACE LOW PRESSURE
SYSTEM. THE WARM FRONT WILL HAVE LIFTED NORTH OF THE AREA BY THIS
TIME PLACING THE AREA IN THE WARM SECTOR. GUIDANCE SUGGESTS THE
DEEPER MOISTURE WILL BEGIN TO LIFT OUT TO THE EAST DURING THE DAY
TUESDAY WELL AHEAD OF THE COLD FRONT. THIS COULD VERY WELL REDUCE
OUR CHANCES FOR PRECIPITATION DURING THE DAY TUESDAY UNTIL THE COLD
FRONT ARRIVES LATER IN THE DAY. POTENTIAL EXISTS WE COULD SEE SOME
SEVERE WEATHER WITH THE COLD FRONT. BUT THAT REMAINS TO BE SEEN AND
DEPENDS ON HOW MUCH SUN WE GET AND HOW UNSTABLE IT GETS.
COLD FRONT SWEEPS EAST TUESDAY EVENING BUT A TROUGH AXIS LINGERS
BACK SOUTHWEST FROM THE LOW PRESSURE SYSTEM INTO WEDNESDAY. THIS
FEATURE WILL LIKELY SPAWN A FEW SHOWERS AND THUNDERSTORMS ACROSS THE
AREA AS WELL. SO WILL KEEP A MENTION OF PRECIPITATION GOING AT THIS
TIME.
SURFACE LOW PRESSURE AND ASSOCIATED TROUGH AXIS WILL LIFT OUT TO THE
NORTHEAST AND THIS WILL BEGIN THE TRANSITION FOR HIGH PRESSURE TO
BEGIN TO BUILD INTO THE REGION THURSDAY INTO THURSDAY NIGHT.
TEMPERATURES ARE DEFINITELY GOING TO BE TRICKY OVER THE NEXT FEW
DAYS DUE TO EXPECTED RAINFALL...CLOUD COVER...AND ADVECTION CHANGES
WITH THE FRONTAL BOUNDARIES IN PLACE. THIS PERIOD COULD TURN OUT TO
BE A BIG HIT OR A BIG BUST IN THE TEMPERATURE DEPARTMENT...
ESPECIALLY THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE BE OVER THE AREA ON FRIDAY AND THEN IT WILL START
DRIFTING SOUTH OVER THE WEEKEND. AT THIS TIME KEPT THE FORECAST DRY.
THE GFS MODEL WAS HINTING AT SOME QPF BRUSHING THE EXTREME NORTHERN
PORTION OF THE FORECAST AREA OVER THE WEEKEND. THIS IS ASSOCIATED
WITH A WEAK BOUNDARY WHICH WILL BE OVER THE CENTRAL LAKES. THE ECMWF
DOES NOT HAVE THIS FEATURE. WILL MONITOR UPCOMING MODEL RUNS FOR ANY
NEW TRENDS. TEMPERATURES WILL BE NEAR NORMAL.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE WILL BE BUILDING TOWARD THE AREA TODAY. SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO MOVE THROUGH THE FORECAST AREA. THE
TIMING IT TOUGH AT THE TAF SITES. IFR CONDITIONS IN MOST OF THE
THUNDERSTORMS...OTHERWISE MVFR. THE HRRR MODEL IS DOING A GOOD JOB
WITH THE TIMING. AT THIS TIME BASED ON THE PATH OF THE LOW KEPT
THE BEST CHANCE OF THUNDER FOR TODAY WEST OF CLE. KEPT SHOWERS AND
MVFR CONDITIONS CONTINUING TONIGHT AS THE LOW AND ASSOCIATED COLD
FRONT MOVES SLOWLY THROUGH THE AREA.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
TUESDAY ACROSS THE ENTIRE FORECAST AREA AND POSSIBLY INTO
WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
THE EASTERLY FLOW WILL BECOME SOUTHERLY TODAY AS A LOW MOVES ACROSS
WESTERN LAKE ERIE TONIGHT AND A COLD FRONT MOVES THROUGH LATE
TONIGHT INTO TUESDAY. SOME OF THE THUNDERSTORMS LATER TODAY THROUGH
TUESDAY COULD BE STRONG ENOUGH TO WARRANT THE NEED FOR SPECIAL
MARINE WARNINGS. THIS IS A SLOW MOVING SYSTEM SO THE WINDS BEHIND
THE FRONT WILL NOT GET STRONG UNTIL LATE TUESDAY NIGHT INTO
WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED THEN. CONDITIONS
WEDNESDAY INTO THURSDAY WILL BE MARGINAL FOR SOME COLD AIR
WATERSPOUTS. IT LOOKS MARGINAL AT THIS TIME...NO MENTION IN THE
GRIDS/FORECASTS.
HIGH PRESSURE WILL BE BUILDING OVER THE LAKE THURSDAY AND THE HIGH
WILL START DRIFTING SOUTH OF THE LAKE OVER THE WEEKEND. FOR THE MOST
PART THE WINDS SHOULD BE LIGHT ENOUGH NOT TO PROMPT THE NEED FOR A
SMALL CRAFT ADVISORY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY/OUDEMAN
NEAR TERM...LOMBARDY/OUDEMAN
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
928 AM EDT MON AUG 11 2014
.SYNOPSIS...
LOW PRESSURE ACROSS EAST-CENTRAL INDIANA WILL DRIFT NORTHWARD
REACHING LAKE HURON BY TUESDAY MORNING. THIS WILL TAKE A WARM
FRONT NORTH ACROSS THE AREA TODAY AND A COLD FRONT TUESDAY. THE
LOW PRESSURE SYSTEM WILL CONTINUE TO MOVE SLOWLY NORTHEAST AND
EXTEND A TROUGH SOUTHWEST ACROSS THE REGION WEDNESDAY NIGHT INTO
THURSDAY. HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION FOR THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS AND THUNDERSTORMS WORKING NORTH INTO THE AREA WITH
ADDITIONAL SHOWERS/THUNDERSTORMS DEVELOPING OVERHEAD TODAY.
OVER THE NEXT COUPLE OF DAYS A BROACH UPPER TROUGH WILL ENCOMPASS
THE EASTERN GREAT LAKES AND NEW ENGLAND. LOW PRESSURE ACROSS EAST
CENTRAL INDIANA WILL MOVE NORTH TOWARD LAKE HURON TODAY. MOISTURE
LEVELS ARE HIGH AND RAINFALL RATES COULD POTENTIALLY BE WILL BE AS
WELL. PRECIPITABLE WATER VALUES WILL NEAR 2 INCHES BY THIS
AFTERNOON. AREA IN A SLIGHT RISK FOR EXCESSIVE RAINFALL.
SEVERE WEATHER THREAT IS POSSIBLE WITH THE WARM FRONT AS HODOGRAPHS
ANTICIPATE SOME SHEAR IS POSSIBLE ALONG THE FRONTAL BOUNDARY.
THEREFORE...IT IS POSSIBLE FOR A FEW STORMS TO BECOME SEVERE LATER
TODAY.
GUIDANCE IS REALLY STRUGGLING WITH TEMPERATURES OVER THE LAST FEW
RUNS WITH NO CONSISTENCY SO WILL BE LEANING TOWARD CURRENT FORECAST
WITH A SLIGHT TWEAK UPWARD A FEW DEGREES TO ACCOUNT FOR A SLIGHTLY
LATER ARRIVAL OF THE PRECIPITATION...ESPECIALLY IN THE EAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DEEP DIGGING UPPER LEVEL TROUGH DIVES INTO THE EASTERN UNITED STATES
TONIGHT AND THIS HELPS TO ENHANCE THE DEEPENING SURFACE LOW PRESSURE
SYSTEM. THE WARM FRONT WILL HAVE LIFTED NORTH OF THE AREA BY THIS
TIME PLACING THE AREA IN THE WARM SECTOR. GUIDANCE SUGGESTS THE
DEEPER MOISTURE WILL BEGIN TO LIFT OUT TO THE EAST DURING THE DAY
TUESDAY WELL AHEAD OF THE COLD FRONT. THIS COULD VERY WELL REDUCE
OUR CHANCES FOR PRECIPITATION DURING THE DAY TUESDAY UNTIL THE COLD
FRONT ARRIVES LATER IN THE DAY. POTENTIAL EXISTS WE COULD SEE SOME
SEVERE WEATHER WITH THE COLD FRONT. BUT THAT REMAINS TO BE SEEN AND
DEPENDS ON HOW MUCH SUN WE GET AND HOW UNSTABLE IT GETS.
COLD FRONT SWEEPS EAST TUESDAY EVENING BUT A TROUGH AXIS LINGERS
BACK SOUTHWEST FROM THE LOW PRESSURE SYSTEM INTO WEDNESDAY. THIS
FEATURE WILL LIKELY SPAWN A FEW SHOWERS AND THUNDERSTORMS ACROSS THE
AREA AS WELL. SO WILL KEEP A MENTION OF PRECIPITATION GOING AT THIS
TIME.
SURFACE LOW PRESSURE AND ASSOCIATED TROUGH AXIS WILL LIFT OUT TO THE
NORTHEAST AND THIS WILL BEGIN THE TRANSITION FOR HIGH PRESSURE TO
BEGIN TO BUILD INTO THE REGION THURSDAY INTO THURSDAY NIGHT.
TEMPERATURES ARE DEFINITELY GOING TO BE TRICKY OVER THE NEXT FEW
DAYS DUE TO EXPECTED RAINFALL...CLOUD COVER...AND ADVECTION CHANGES
WITH THE FRONTAL BOUNDARIES IN PLACE. THIS PERIOD COULD TURN OUT TO
BE A BIG HIT OR A BIG BUST IN THE TEMPERATURE DEPARTMENT...
ESPECIALLY THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE BE OVER THE AREA ON FRIDAY AND THEN IT WILL START
DRIFTING SOUTH OVER THE WEEKEND. AT THIS TIME KEPT THE FORECAST DRY.
THE GFS MODEL WAS HINTING AT SOME QPF BRUSHING THE EXTREME NORTHERN
PORTION OF THE FORECAST AREA OVER THE WEEKEND. THIS IS ASSOCIATED
WITH A WEAK BOUNDARY WHICH WILL BE OVER THE CENTRAL LAKES. THE ECMWF
DOES NOT HAVE THIS FEATURE. WILL MONITOR UPCOMING MODEL RUNS FOR ANY
NEW TRENDS. TEMPERATURES WILL BE NEAR NORMAL.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE WILL BE BUILDING TOWARD THE AREA TODAY. SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO MOVE THROUGH THE FORECAST AREA. THE
TIMING IT TOUGH AT THE TAF SITES. IFR CONDITIONS IN MOST OF THE
THUNDERSTORMS...OTHERWISE MVFR. THE HRRR MODEL IS DOING A GOOD JOB
WITH THE TIMING. AT THIS TIME BASED ON THE PATH OF THE LOW KEPT
THE BEST CHANCE OF THUNDER FOR TODAY WEST OF CLE. KEPT SHOWERS AND
MVFR CONDITIONS CONTINUING TONIGHT AS THE LOW AND ASSOCIATED COLD
FRONT MOVES SLOWLY THROUGH THE AREA.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
TUESDAY ACROSS THE ENTIRE FORECAST AREA AND POSSIBLY INTO
WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
THE EASTERLY FLOW WILL BECOME SOUTHERLY TODAY AS A LOW MOVES ACROSS
WESTERN LAKE ERIE TONIGHT AND A COLD FRONT MOVES THROUGH LATE
TONIGHT INTO TUESDAY. SOME OF THE THUNDERSTORMS LATER TODAY THROUGH
TUESDAY COULD BE STRONG ENOUGH TO WARRANT THE NEED FOR SPECIAL
MARINE WARNINGS. THIS IS A SLOW MOVING SYSTEM SO THE WINDS BEHIND
THE FRONT WILL NOT GET STRONG UNTIL LATE TUESDAY NIGHT INTO
WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED THEN. CONDITIONS
WEDNESDAY INTO THURSDAY WILL BE MARGINAL FOR SOME COLD AIR
WATERSPOUTS. IT LOOKS MARGINAL AT THIS TIME...NO MENTION IN THE
GRIDS/FORECASTS.
HIGH PRESSURE WILL BE BUILDING OVER THE LAKE THURSDAY AND THE HIGH
WILL START DRIFTING SOUTH OF THE LAKE OVER THE WEEKEND. FOR THE MOST
PART THE WINDS SHOULD BE LIGHT ENOUGH NOT TO PROMPT THE NEED FOR A
SMALL CRAFT ADVISORY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY/OUDEMAN
NEAR TERM...LOMBARDY/OUDEMAN
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
736 AM EDT MON AUG 11 2014
.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTH INTO THE CENTRAL GREAT LAKES BY TUESDAY
MORNING. A WARM FRONT FROM THE LOW WILL MOVE NORTH OF THE AREA
TUESDAY MORNING FOLLOWED BY A COLD FRONT TUESDAY EVENING. THE LOW
PRESSURE SYSTEM IS EXPECTED TO MOVE SLOWLY NORTHEAST AND EXTEND A
TROUGH OF LOW PRESSURE SOUTHWEST ACROSS THE REGION WEDNESDAY NIGHT
INTO THURSDAY. HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION FOR
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS AND THUNDERSTORMS ARE BEGINNING TO DEVELOP RIGHT ON
SCHEDULE. WILL CONTINUE TO SEE A GRADUAL EXPANSION OF THE
PRECIPITATION THROUGH THE DAY. MADE A MINOR UPDATE TO CURRENT
HOURLY TEMPERATURES. OTHERWISE...NO MAJOR CHANGES EXPECTED WITH
THIS UPDATE.
PREVIOUS DISCUSSION...
UPPER LEVEL PATTERN TRENDING MORE TOWARD A WINTER LIKE PATTERN
VERSUS A SUMMER PATTERN. DEEP DIGGING UPPER LEVEL TROUGH WILL DIVE
SOUTHEAST INTO THE REGION BEGINNING TODAY. THIS WILL SET THE STAGE
FOR CYCLOGENESIS TO OCCUR OVER INDIANA TODAY. THE LOW WILL DEEPEN
AND MOVE SLOWLY NORTH BY THIS EVENING.
COPIOUS AMOUNTS OF MOISTURE WILL STREAM NORTH OUT OF THE GULF OF
MEXICO TODAY MAKING FOR A VERY MOIST SOUNDING. LATEST SOUNDINGS FROM
00Z INDICATE DEEP MOISTURE ALREADY STREAMING INTO THE CINCINNATI
AREA. SOUNDINGS TO THE NORTH ARE VERY DRY AND HENCE PRECIPITATION IS
HAVING A HARD TIME MAKING PROGRESS TO THE NORTH. THE DEEP MOISTURE
WILL ADVANCE NORTH FAIRLY QUICKLY THIS MORNING. LATEST HRRR MODEL
SHOWS PRECIPITATION BLOSSOMING FAIRLY QUICKLY THIS MORNING ACROSS
THE WEST IN RESPONSE TO THE ADVANCING DEEP MOISTURE.
DUE TO THE VERY MOIST ENVIRONMENT EXPECTED TO BE IN PLACE LATER
TODAY AND THE VIGOROUS UPPER LEVEL POSITIVE VORTICITY MAXIMUM ALONG
WITH THE INTERACTION WITH THE WARM FRONT...EXPECTING POTENTIAL FOR
HEAVY RAINERS. PRECIPITABLE WATER VALUES ACROSS SOUTHERN OHIO ARE
ALREADY IN THE NEIGHBORHOOD OF 1.75 INCH. PRECIPITABLE WATER VALUES
SURGE TO JUST OVER 2 INCHES THIS AFTERNOON. FLOW WILL NOT BE
ESPECIALLY LIGHT ALOFT AND THEREFORE NOT EXPECTING VERY SLOW MOVING
CELLS. HOWEVER...LATEST EXCESSIVE PRECIPITATION OUTLOOK HAS OUR AREA
IN A SLIGHT RISK FOR EXCESSIVE RAINFALL.
SEVERE WEATHER THREAT IS POSSIBLE WITH THE WARM FRONT AS HODOGRAPHS
ANTICIPATE SOME SHEAR IS POSSIBLE ALONG THE FRONTAL BOUNDARY.
THEREFORE...IT IS POSSIBLE FOR A FEW STORMS TO BECOME SEVERE LATER
TODAY.
GUIDANCE IS REALLY STRUGGLING WITH TEMPERATURES OVER THE LAST FEW
RUNS WITH NO CONSISTENCY SO WILL BE LEANING TOWARD CURRENT FORECAST
WITH A SLIGHT TWEAK UPWARD A FEW DEGREES TO ACCOUNT FOR A SLIGHTLY
LATER ARRIVAL OF THE PRECIPITATION...ESPECIALLY IN THE EAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DEEP DIGGING UPPER LEVEL TROUGH DIVES INTO THE EASTERN UNITED STATES
TONIGHT AND THIS HELPS TO ENHANCE THE DEEPENING SURFACE LOW PRESSURE
SYSTEM. THE WARM FRONT WILL HAVE LIFTED NORTH OF THE AREA BY THIS
TIME PLACING THE AREA IN THE WARM SECTOR. GUIDANCE SUGGESTS THE
DEEPER MOISTURE WILL BEGIN TO LIFT OUT TO THE EAST DURING THE DAY
TUESDAY WELL AHEAD OF THE COLD FRONT. THIS COULD VERY WELL REDUCE
OUR CHANCES FOR PRECIPITATION DURING THE DAY TUESDAY UNTIL THE COLD
FRONT ARRIVES LATER IN THE DAY. POTENTIAL EXISTS WE COULD SEE SOME
SEVERE WEATHER WITH THE COLD FRONT. BUT THAT REMAINS TO BE SEEN AND
DEPENDS ON HOW MUCH SUN WE GET AND HOW UNSTABLE IT GETS.
COLD FRONT SWEEPS EAST TUESDAY EVENING BUT A TROUGH AXIS LINGERS
BACK SOUTHWEST FROM THE LOW PRESSURE SYSTEM INTO WEDNESDAY. THIS
FEATURE WILL LIKELY SPAWN A FEW SHOWERS AND THUNDERSTORMS ACROSS THE
AREA AS WELL. SO WILL KEEP A MENTION OF PRECIPITATION GOING AT THIS
TIME.
SURFACE LOW PRESSURE AND ASSOCIATED TROUGH AXIS WILL LIFT OUT TO THE
NORTHEAST AND THIS WILL BEGIN THE TRANSITION FOR HIGH PRESSURE TO
BEGIN TO BUILD INTO THE REGION THURSDAY INTO THURSDAY NIGHT.
TEMPERATURES ARE DEFINITELY GOING TO BE TRICKY OVER THE NEXT FEW
DAYS DUE TO EXPECTED RAINFALL...CLOUD COVER...AND ADVECTION CHANGES
WITH THE FRONTAL BOUNDARIES IN PLACE. THIS PERIOD COULD TURN OUT TO
BE A BIG HIT OR A BIG BUST IN THE TEMPERATURE DEPARTMENT...
ESPECIALLY THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE BE OVER THE AREA ON FRIDAY AND THEN IT WILL START
DRIFTING SOUTH OVER THE WEEKEND. AT THIS TIME KEPT THE FORECAST DRY.
THE GFS MODEL WAS HINTING AT SOME QPF BRUSHING THE EXTREME NORTHERN
PORTION OF THE FORECAST AREA OVER THE WEEKEND. THIS IS ASSOCIATED
WITH A WEAK BOUNDARY WHICH WILL BE OVER THE CENTRAL LAKES. THE ECMWF
DOES NOT HAVE THIS FEATURE. WILL MONITOR UPCOMING MODEL RUNS FOR ANY
NEW TRENDS. TEMPERATURES WILL BE NEAR NORMAL.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE WILL BE BUILDING TOWARD THE AREA TODAY. SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO MOVE THROUGH THE FORECAST AREA. THE
TIMING IT TOUGH AT THE TAF SITES. IFR CONDITIONS IN MOST OF THE
THUNDERSTORMS...OTHERWISE MVFR. THE HRRR MODEL IS DOING A GOOD JOB
WITH THE TIMING. AT THIS TIME BASED ON THE PATH OF THE LOW KEPT
THE BEST CHANCE OF THUNDER FOR TODAY WEST OF CLE. KEPT SHOWERS AND
MVFR CONDITIONS CONTINUING TONIGHT AS THE LOW AND ASSOCIATED COLD
FRONT MOVES SLOWLY THROUGH THE AREA.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
TUESDAY ACROSS THE ENTIRE FORECAST AREA AND POSSIBLY INTO
WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
THE EASTERLY FLOW WILL BECOME SOUTHERLY TODAY AS A LOW MOVES ACROSS
WESTERN LAKE ERIE TONIGHT AND A COLD FRONT MOVES THROUGH LATE
TONIGHT INTO TUESDAY. SOME OF THE THUNDERSTORMS LATER TODAY THROUGH
TUESDAY COULD BE STRONG ENOUGH TO WARRANT THE NEED FOR SPECIAL
MARINE WARNINGS. THIS IS A SLOW MOVING SYSTEM SO THE WINDS BEHIND
THE FRONT WILL NOT GET STRONG UNTIL LATE TUESDAY NIGHT INTO
WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED THEN. CONDITIONS
WEDNESDAY INTO THURSDAY WILL BE MARGINAL FOR SOME COLD AIR
WATERSPOUTS. IT LOOKS MARGINAL AT THIS TIME...NO MENTION IN THE
GRIDS/FORECASTS.
HIGH PRESSURE WILL BE BUILDING OVER THE LAKE THURSDAY AND THE HIGH
WILL START DRIFTING SOUTH OF THE LAKE OVER THE WEEKEND. FOR THE MOST
PART THE WINDS SHOULD BE LIGHT ENOUGH NOT TO PROMPT THE NEED FOR A
SMALL CRAFT ADVISORY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
622 AM EDT MON AUG 11 2014
.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTH INTO THE CENTRAL GREAT LAKES BY TUESDAY
MORNING. A WARM FRONT FROM THE LOW WILL MOVE NORTH OF THE AREA
TUESDAY MORNING FOLLOWED BY A COLD FRONT TUESDAY EVENING. THE LOW
PRESSURE SYSTEM IS EXPECTED TO MOVE SLOWLY NORTHEAST AND EXTEND A
TROUGH OF LOW PRESSURE SOUTHWEST ACROSS THE REGION WEDNESDAY NIGHT
INTO THURSDAY. HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION FOR
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS AND THUNDERSTORMS ARE BEGINNING TO DEVELOP RIGHT ON
SCHEDULE. WILL CONTINUE TO SEE A GRADUAL EXPANSION OF THE
PRECIPITATION THROUGH THE DAY. MADE A MINOR UPDATE TO CURRENT
HOURLY TEMPERATURES. OTHERWISE...NO MAJOR CHANGES EXPECTED WITH
THIS UPDATE.
PREVIOUS DISCUSSION...
UPPER LEVEL PATTERN TRENDING MORE TOWARD A WINTER LIKE PATTERN
VERSUS A SUMMER PATTERN. DEEP DIGGING UPPER LEVEL TROUGH WILL DIVE
SOUTHEAST INTO THE REGION BEGINNING TODAY. THIS WILL SET THE STAGE
FOR CYCLOGENESIS TO OCCUR OVER INDIANA TODAY. THE LOW WILL DEEPEN
AND MOVE SLOWLY NORTH BY THIS EVENING.
COPIOUS AMOUNTS OF MOISTURE WILL STREAM NORTH OUT OF THE GULF OF
MEXICO TODAY MAKING FOR A VERY MOIST SOUNDING. LATEST SOUNDINGS FROM
00Z INDICATE DEEP MOISTURE ALREADY STREAMING INTO THE CINCINNATI
AREA. SOUNDINGS TO THE NORTH ARE VERY DRY AND HENCE PRECIPITATION IS
HAVING A HARD TIME MAKING PROGRESS TO THE NORTH. THE DEEP MOISTURE
WILL ADVANCE NORTH FAIRLY QUICKLY THIS MORNING. LATEST HRRR MODEL
SHOWS PRECIPITATION BLOSSOMING FAIRLY QUICKLY THIS MORNING ACROSS
THE WEST IN RESPONSE TO THE ADVANCING DEEP MOISTURE.
DUE TO THE VERY MOIST ENVIRONMENT EXPECTED TO BE IN PLACE LATER
TODAY AND THE VIGOROUS UPPER LEVEL POSITIVE VORTICITY MAXIMUM ALONG
WITH THE INTERACTION WITH THE WARM FRONT...EXPECTING POTENTIAL FOR
HEAVY RAINERS. PRECIPITABLE WATER VALUES ACROSS SOUTHERN OHIO ARE
ALREADY IN THE NEIGHBORHOOD OF 1.75 INCH. PRECIPITABLE WATER VALUES
SURGE TO JUST OVER 2 INCHES THIS AFTERNOON. FLOW WILL NOT BE
ESPECIALLY LIGHT ALOFT AND THEREFORE NOT EXPECTING VERY SLOW MOVING
CELLS. HOWEVER...LATEST EXCESSIVE PRECIPITATION OUTLOOK HAS OUR AREA
IN A SLIGHT RISK FOR EXCESSIVE RAINFALL.
SEVERE WEATHER THREAT IS POSSIBLE WITH THE WARM FRONT AS HODOGRAPHS
ANTICIPATE SOME SHEAR IS POSSIBLE ALONG THE FRONTAL BOUNDARY.
THEREFORE...IT IS POSSIBLE FOR A FEW STORMS TO BECOME SEVERE LATER
TODAY.
GUIDANCE IS REALLY STRUGGLING WITH TEMPERATURES OVER THE LAST FEW
RUNS WITH NO CONSISTENCY SO WILL BE LEANING TOWARD CURRENT FORECAST
WITH A SLIGHT TWEAK UPWARD A FEW DEGREES TO ACCOUNT FOR A SLIGHTLY
LATER ARRIVAL OF THE PRECIPITATION...ESPECIALLY IN THE EAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DEEP DIGGING UPPER LEVEL TROUGH DIVES INTO THE EASTERN UNITED STATES
TONIGHT AND THIS HELPS TO ENHANCE THE DEEPENING SURFACE LOW PRESSURE
SYSTEM. THE WARM FRONT WILL HAVE LIFTED NORTH OF THE AREA BY THIS
TIME PLACING THE AREA IN THE WARM SECTOR. GUIDANCE SUGGESTS THE
DEEPER MOISTURE WILL BEGIN TO LIFT OUT TO THE EAST DURING THE DAY
TUESDAY WELL AHEAD OF THE COLD FRONT. THIS COULD VERY WELL REDUCE
OUR CHANCES FOR PRECIPITATION DURING THE DAY TUESDAY UNTIL THE COLD
FRONT ARRIVES LATER IN THE DAY. POTENTIAL EXISTS WE COULD SEE SOME
SEVERE WEATHER WITH THE COLD FRONT. BUT THAT REMAINS TO BE SEEN AND
DEPENDS ON HOW MUCH SUN WE GET AND HOW UNSTABLE IT GETS.
COLD FRONT SWEEPS EAST TUESDAY EVENING BUT A TROUGH AXIS LINGERS
BACK SOUTHWEST FROM THE LOW PRESSURE SYSTEM INTO WEDNESDAY. THIS
FEATURE WILL LIKELY SPAWN A FEW SHOWERS AND THUNDERSTORMS ACROSS THE
AREA AS WELL. SO WILL KEEP A MENTION OF PRECIPITATION GOING AT THIS
TIME.
SURFACE LOW PRESSURE AND ASSOCIATED TROUGH AXIS WILL LIFT OUT TO THE
NORTHEAST AND THIS WILL BEGIN THE TRANSITION FOR HIGH PRESSURE TO
BEGIN TO BUILD INTO THE REGION THURSDAY INTO THURSDAY NIGHT.
TEMPERATURES ARE DEFINITELY GOING TO BE TRICKY OVER THE NEXT FEW
DAYS DUE TO EXPECTED RAINFALL...CLOUD COVER...AND ADVECTION CHANGES
WITH THE FRONTAL BOUNDARIES IN PLACE. THIS PERIOD COULD TURN OUT TO
BE A BIG HIT OR A BIG BUST IN THE TEMPERATURE DEPARTMENT...
ESPECIALLY THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE BE OVER THE AREA ON FRIDAY AND THEN IT WILL START
DRIFTING SOUTH OVER THE WEEKEND. AT THIS TIME KEPT THE FORECAST DRY.
THE GFS MODEL WAS HINTING AT SOME QPF BRUSHING THE EXTREME NORTHERN
PORTION OF THE FORECAST AREA OVER THE WEEKEND. THIS IS ASSOCIATED
WITH A WEAK BOUNDARY WHICH WILL BE OVER THE CENTRAL LAKES. THE ECMWF
DOES NOT HAVE THIS FEATURE. WILL MONITOR UPCOMING MODEL RUNS FOR ANY
NEW TRENDS. TEMPERATURES WILL BE NEAR NORMAL.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE WILL BE BUILDING TOWARD THE AREA. SHOWERS AND SOME
THUNDERSTORMS WILL BE ON THE INCREASE THIS MORNING. WENT CLOSE TO
THE HRRR MODEL WITH THE TIMING. CONDITIONS WILL DETERIORATE TO MVFR
CEILINGS AND IFR CONDITIONS WILL OCCUR IN THE HEAVIEST
SHOWERS/THUNDERSTORMS. AT THIS TIME BASED ON THE PATH OF THE LOW
KEPT THE BEST CHANCE OF THUNDER FOR TODAY WEST OF CLE. KEPT
SHOWERS AND MVFR CONDITIONS CONTINUING TONIGHT AS THE LOW AND
ASSOCIATED COLD FRONT MOVES SLOWLY THROUGH THE AREA.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
TUESDAY ACROSS THE ENTIRE FORECAST AREA AND POSSIBLY INTO
WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
THE EASTERLY FLOW WILL BECOME SOUTHERLY TODAY AS A LOW MOVES ACROSS
WESTERN LAKE ERIE TONIGHT AND A COLD FRONT MOVES THROUGH LATE
TONIGHT INTO TUESDAY. SOME OF THE THUNDERSTORMS LATER TODAY THROUGH
TUESDAY COULD BE STRONG ENOUGH TO WARRANT THE NEED FOR SPECIAL
MARINE WARNINGS. THIS IS A SLOW MOVING SYSTEM SO THE WINDS BEHIND
THE FRONT WILL NOT GET STRONG UNTIL LATE TUESDAY NIGHT INTO
WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED THEN. CONDITIONS
WEDNESDAY INTO THURSDAY WILL BE MARGINAL FOR SOME COLD AIR
WATERSPOUTS. IT LOOKS MARGINAL AT THIS TIME...NO MENTION IN THE
GRIDS/FORECASTS.
HIGH PRESSURE WILL BE BUILDING OVER THE LAKE THURSDAY AND THE HIGH
WILL START DRIFTING SOUTH OF THE LAKE OVER THE WEEKEND. FOR THE MOST
PART THE WINDS SHOULD BE LIGHT ENOUGH NOT TO PROMPT THE NEED FOR A
SMALL CRAFT ADVISORY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
400 AM EDT MON AUG 11 2014
.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTH INTO THE CENTRAL GREAT LAKES BY TUESDAY
MORNING. A WARM FRONT FROM THE LOW WILL MOVE NORTH OF THE AREA
TUESDAY MORNING FOLLOWED BY A COLD FRONT TUESDAY EVENING. THE LOW
PRESSURE SYSTEM IS EXPECTED TO MOVE SLOWLY NORTHEAST AND EXTEND A
TROUGH OF LOW PRESSURE SOUTHWEST ACROSS THE REGION WEDNESDAY NIGHT
INTO THURSDAY. HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION FOR
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL PATTERN TRENDING MORE TOWARD A WINTER LIKE PATTERN
VERSUS A SUMMER PATTERN. DEEP DIGGING UPPER LEVEL TROUGH WILL DIVE
SOUTHEAST INTO THE REGION BEGINNING TODAY. THIS WILL SET THE STAGE
FOR CYCLOGENESIS TO OCCUR OVER INDIANA TODAY. THE LOW WILL DEEPEN
AND MOVE SLOWLY NORTH BY THIS EVENING.
COPIOUS AMOUNTS OF MOISTURE WILL STREAM NORTH OUT OF THE GULF OF
MEXICO TODAY MAKING FOR A VERY MOIST SOUNDING. LATEST SOUNDINGS FROM
00Z INDICATE DEEP MOISTURE ALREADY STREAMING INTO THE CINCINNATI
AREA. SOUNDINGS TO THE NORTH ARE VERY DRY AND HENCE PRECIPITATION IS
HAVING A HARD TIME MAKING PROGRESS TO THE NORTH. THE DEEP MOISTURE
WILL ADVANCE NORTH FAIRLY QUICKLY THIS MORNING. LATEST HRRR MODEL
SHOWS PRECIPITATION BLOSSOMING FAIRLY QUICKLY THIS MORNING ACROSS
THE WEST IN RESPONSE TO THE ADVANCING DEEP MOISTURE.
DUE TO THE VERY MOIST ENVIRONMENT EXPECTED TO BE IN PLACE LATER
TODAY AND THE VIGOROUS UPPER LEVEL POSITIVE VORTICITY MAXIMUM ALONG
WITH THE INTERACTION WITH THE WARM FRONT...EXPECTING POTENTIAL FOR
HEAVY RAINERS. PRECIPITABLE WATER VALUES ACROSS SOUTHERN OHIO ARE
ALREADY IN THE NEIGHBORHOOD OF 1.75 INCH. PRECIPITABLE WATER VALUES
SURGE TO JUST OVER 2 INCHES THIS AFTERNOON. FLOW WILL NOT BE
ESPECIALLY LIGHT ALOFT AND THEREFORE NOT EXPECTING VERY SLOW MOVING
CELLS. HOWEVER...LATEST EXCESSIVE PRECIPITATION OUTLOOK HAS OUR AREA
IN A SLIGHT RISK FOR EXCESSIVE RAINFALL.
SEVERE WEATHER THREAT IS POSSIBLE WITH THE WARM FRONT AS HODOGRAPHS
ANTICIPATE SOME SHEAR IS POSSIBLE ALONG THE FRONTAL BOUNDARY.
THEREFORE...IT IS POSSIBLE FOR A FEW STORMS TO BECOME SEVERE LATER
TODAY.
GUIDANCE IS REALLY STRUGGLING WITH TEMPERATURES OVER THE LAST FEW
RUNS WITH NO CONSISTENCY SO WILL BE LEANING TOWARD CURRENT FORECAST
WITH A SLIGHT TWEAK UPWARD A FEW DEGREES TO ACCOUNT FOR A SLIGHTLY
LATER ARRIVAL OF THE PRECIPITATION...ESPECIALLY IN THE EAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DEEP DIGGING UPPER LEVEL TROUGH DIVES INTO THE EASTERN UNITED STATES
TONIGHT AND THIS HELPS TO ENHANCE THE DEEPENING SURFACE LOW PRESSURE
SYSTEM. THE WARM FRONT WILL HAVE LIFTED NORTH OF THE AREA BY THIS
TIME PLACING THE AREA IN THE WARM SECTOR. GUIDANCE SUGGESTS THE
DEEPER MOISTURE WILL BEGIN TO LIFT OUT TO THE EAST DURING THE DAY
TUESDAY WELL AHEAD OF THE COLD FRONT. THIS COULD VERY WELL REDUCE
OUR CHANCES FOR PRECIPITATION DURING THE DAY TUESDAY UNTIL THE COLD
FRONT ARRIVES LATER IN THE DAY. POTENTIAL EXISTS WE COULD SEE SOME
SEVERE WEATHER WITH THE COLD FRONT. BUT THAT REMAINS TO BE SEEN AND
DEPENDS ON HOW MUCH SUN WE GET AND HOW UNSTABLE IT GETS.
COLD FRONT SWEEPS EAST TUESDAY EVENING BUT A TROUGH AXIS LINGERS
BACK SOUTHWEST FROM THE LOW PRESSURE SYSTEM INTO WEDNESDAY. THIS
FEATURE WILL LIKELY SPAWN A FEW SHOWERS AND THUNDERSTORMS ACROSS THE
AREA AS WELL. SO WILL KEEP A MENTION OF PRECIPITATION GOING AT THIS
TIME.
SURFACE LOW PRESSURE AND ASSOCIATED TROUGH AXIS WILL LIFT OUT TO THE
NORTHEAST AND THIS WILL BEGIN THE TRANSITION FOR HIGH PRESSURE TO
BEGIN TO BUILD INTO THE REGION THURSDAY INTO THURSDAY NIGHT.
TEMPERATURES ARE DEFINITELY GOING TO BE TRICKY OVER THE NEXT FEW
DAYS DUE TO EXPECTED RAINFALL...CLOUD COVER...AND ADVECTION CHANGES
WITH THE FRONTAL BOUNDARIES IN PLACE. THIS PERIOD COULD TURN OUT TO
BE A BIG HIT OR A BIG BUST IN THE TEMPERATURE DEPARTMENT...
ESPECIALLY THIS TIME OF YEAR.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE BE OVER THE AREA ON FRIDAY AND THEN IT WILL START
DRIFTING SOUTH OVER THE WEEKEND. AT THIS TIME KEPT THE FORECAST DRY.
THE GFS MODEL WAS HINTING AT SOME QPF BRUSHING THE EXTREME NORTHERN
PORTION OF THE FORECAST AREA OVER THE WEEKEND. THIS IS ASSOCIATED
WITH A WEAK BOUNDARY WHICH WILL BE OVER THE CENTRAL LAKES. THE ECMWF
DOES NOT HAVE THIS FEATURE. WILL MONITOR UPCOMING MODEL RUNS FOR ANY
NEW TRENDS. TEMPERATURES WILL BE NEAR NORMAL.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE WILL BE BUILDING TOWARD THE AREA. SHOWERS AND SOME
THUNDERSTORMS WILL BE ON THE INCREASE THIS MORNING. WENT CLOSE TO
THE HRRR MODEL WITH THE TIMING. CONDITIONS WILL DETERIORATE TO MVFR
CEILINGS AND IFR CONDITIONS WILL OCCUR IN THE HEAVIEST
SHOWERS/THUNDERSTORMS. AT THIS TIME BASED ON THE PATH OF THE LOW
KEPT THE BEST CHANCE OF THUNDER FOR TODAY WEST OF CLE. KEPT
SHOWERS AND MVFR CONDITIONS CONTINUING TONIGHT AS THE LOW AND
ASSOCIATED COLD FRONT MOVES SLOWLY THROUGH THE AREA.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
TUESDAY ACROSS THE ENTIRE FORECAST AREA AND POSSIBLY INTO
WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
THE EASTERLY FLOW WILL BECOME SOUTHERLY TODAY AS A LOW MOVES ACROSS
WESTERN LAKE ERIE TONIGHT AND A COLD FRONT MOVES THROUGH LATE
TONIGHT INTO TUESDAY. SOME OF THE THUNDERSTORMS LATER TODAY THROUGH
TUESDAY COULD BE STRONG ENOUGH TO WARRANT THE NEED FOR SPECIAL
MARINE WARNINGS. THIS IS A SLOW MOVING SYSTEM SO THE WINDS BEHIND
THE FRONT WILL NOT GET STRONG UNTIL LATE TUESDAY NIGHT INTO
WEDNESDAY. A SMALL CRAFT ADVISORY MAY BE NEEDED THEN. CONDITIONS
WEDNESDAY INTO THURSDAY WILL BE MARGINAL FOR SOME COLD AIR
WATERSPOUTS. IT LOOKS MARGINAL AT THIS TIME...NO MENTION IN THE
GRIDS/FORECASTS.
HIGH PRESSURE WILL BE BUILDING OVER THE LAKE THURSDAY AND THE HIGH
WILL START DRIFTING SOUTH OF THE LAKE OVER THE WEEKEND. FOR THE MOST
PART THE WINDS SHOULD BE LIGHT ENOUGH NOT TO PROMPT THE NEED FOR A
SMALL CRAFT ADVISORY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
203 AM EDT MON AUG 11 2014
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE EASTERN GREAT LAKES WILL MOVE OFF
THE EAST COAST TONIGHT. A WEAK AREA OF LOW PRESSURE AND WARM FRONT
OVER THE LOWER OHIO VALLEY WILL DRIFT NORTHEAST TO THE LOWER GREAT
LAKES BY MONDAY NIGHT. A COLD FRONT FROM THE UPPER MIDWEST WILL
DROP ACROSS THE AREA ON TUESDAY AND HIGH PRESSURE WILL BEGIN TO
BUILD OVER THE REGION ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CLOUD COVER WILL INCREASE OVERNIGHT AS THE UPPER LEVEL TROUGH
DEEPENS TO OUR WEST AND SURFACE LOW PRESSURE BECOMES MORE
CONSOLIDATED OVER INDIANA. SHOWERS AND THUNDERSTORMS HAVE BEEN INCREASING
ACROSS SW OHIO WITH A FEW STRAY STORMS DEVELOPING AS FAR NORTH AS
THE BOUNDARY IN THE VICINITY OF I-70. THE TREND OVER THE NEXT FEW
HOURS SHOULD BE FOR STORMS TO DECREASE AS DIURNAL HEATING
WANES...WITH AN UPTICK EXPECTED IN WESTERN/CENTRAL OHIO AFTER
07-08Z WHEN THE WINDS BELOW 700MB VEER TO MORE SOUTHERLY AND
MOISTURE ADVECTION REALLY INCREASES. THE 00Z ILN SOUNDING THIS
EVENING WAS MOISTENING UP WITH PW VALUE ALREADY UP TO 1.79 INCHES.
WE WILL SEE SHOWER INITIATION MAINLY SOUTH OF A LINE FROM BOWLING
GREEN TO MANSFIELD BEFORE 12Z...CONTINUING TO SPREAD NORTH AND
EAST DURING THE MORNING. RAISED POPS ACROSS OUR SW COUNTIES TO
ABOUT 50 PERCENT FOR THE OVERNIGHT PERIOD...AND SPED TIMING OF
PRECIP UP FOR MONDAY FOR ALL BUT EXTREME NE OH/NW PA. 00Z/11 NAM
HAS COME IN AND SUPPORTS BOTH THE HIGHER POPS IN THE SW TONIGHT
AND FASTER TREND ON MONDAY.
PREVIOUS DISCUSSION...
SKIES ARE PARTLY CLOUDY AND WILL REMAIN THAT WAY THROUGH
THE EVENING. SURFACE MOISTURE HAS ALREADY BEGUN TO INCREASE AND
DEW POINTS ARE INTO THE MIDDLE 60S MOST AREAS. THE THREAT FOR
PRECIP WILL BEGIN TO INCREASE IN THE SOUTH AND SOUTHWEST LATE
TONIGHT AS A WARM FRONT APPROACHES. WILL KEEP CHANCE POPS THROUGH
12Z AS IN THE PREVIOUS FORECAST PACKAGE. GIVEN THE CURRENT
DEW POINTS GUIDANCE TEMPS MAY BE A TAD COOL FOR TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
WET WEATHER IS EXPECTED DURING THE PERIOD. MUCH OF THE AREA HAS
GOTTEN DRY SO RAIN IN MANY AREAS WILL BE BENEFICIAL AND WELCOMED.
THE GUIDANCE COMING IN SHOWS PRECIP BLOSSOMING ACROSS NW OH
TOMORROW MORNING. THE PRECIP THREAT WILL REACH THE I-77 CORRIDOR
BY MIDDAY AND ALL BUT NW PA SHOULD BE WET BY LATE AFTERNOON. WILL
BUMP PRECIP CHANCES UP TO CATEGORICAL MUCH OF THE AREA ON MONDAY
AND IN THE EAST ON MONDAY NIGHT. IT DOESN`T APPEAR THAT SEVERE
WEATHER WILL BE AN ISSUE TOMORROW GIVEN A LACK OF SHEAR AND STRONG
LOW LEVEL FORCING. WILL HOWEVER HAVE TO BE CONCERNED ABOUT LOCALLY
HEAVY RAINFALL FROM TRAINING STORMS GIVEN THE WEAK STEERING FLOW
ALOFT. PRECIPITABLE WATER VALUES WILL APPROACH TWO INCHES BY LATE
MONDAY EVENING SO HAVE GONE AHEAD AND ADDED THE MENTION OF HEAVY
RAIN TO THE FORECAST. REALISTICALLY...MOST OF THE AREA SHOULD SEE
AN INCH OR MORE OF RAINFALL BY TUESDAY EVENING. THE PRECIP MAY DIMINISH
LATE MONDAY NIGHT BUT A COLD FRONT MOVING THROUGH ON TUESDAY
SHOULD KICK OFF ANOTHER ROUND OF STORMS. BEST CHANCES WILL BE IN
THE EAST. SOME DRIER AND COOLER AIR MOVING IN ALOFT WILL RESULT IN
BETTER INSTABILITY AND SHEAR BUT ANY SEVERE WEATHER THAT FORMS
SHOULD BE ISOLATED IN COVERAGE. THE WEST WILL DRY OUT ON TUESDAY
NIGHT BUT INSTABILITY SHOWERS AND STORMS WILL BE POSSIBLE IN THE
EAST THROUGH WEDNESDAY. HIGH PRESSURE WILL THEN WIN OUT FOR GOOD.
HAVE USED A BLEND OF GUIDANCE TEMPS DURING THE PERIOD. TOMORROW
WILL BE RATHER MUGGY BUT THE REMAINDER OF THE PERIOD WILL SEE
BELOW NORMAL READINGS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
UPPER LEVEL LOW WILL REMAIN OVER MUCH OF THE REGION THROUGH THE
FORECAST PERIOD. A FEW WEAK WAVES WILL ROTATE THROUGH THE TROF
DURING THE EXTENDED PERIOD. THE GFS HINTS AT WEAK SYSTEM MOVING
ACROSS THE FORECAST AREA ON THURSDAY. MODELS ARE INDICATING VERY
LIMITED MOISTURE WITH WHAT APPEARS TO BE A WEAK BACK DOOR COLD
FRONT. I WILL NOT MENTION PRECIPITATION WITH THE SYSTEM AT THIS
TIME. A RETURN FLOW WILL ESTABLISH ITSELF LATE NEXT WEEK AND A WARM
FRONT WILL MOVE NORTHWARD. THIS SYSTEM COULD BRING SOME SCATTERED
SHOWERS AND THUNDERSTORMS LATE SATURDAY OR SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE WILL BE BUILDING TOWARD THE AREA. SHOWERS AND SOME
THUNDERSTORMS WILL BE ON THE INCREASE THIS MORNING. WENT CLOSE TO
THE HRRR MODEL WITH THE TIMING. CONDITIONS WILL DETERIORATE TO MVFR
CEILINGS AND IFR CONDITIONS WILL OCCUR IN THE HEAVIEST
SHOWERS/THUNDERSTORMS. AT THIS TIME BASED ON THE PATH OF THE LOW
KEPT THE BEST CHANCE OF THUNDER FOR TODAY WEST OF CLE. KEPT
SHOWERS AND MVFR CONDITIONS CONTINUING TONIGHT AS THE LOW AND
ASSOCIATED COLD FRONT MOVES SLOWLY THROUGH THE AREA.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
TUESDAY ACROSS THE ENTIRE FORECAST AREA AND POSSIBLY INTO
WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
EASTERLY FLOW OVERNIGHT WILL BECOME SOUTHEAST TOWARDS MONDAY
MORNING. AS A SURFACE LOW PRESSURE SYSTEMS DEVELOPS TO THE WEST
OF THE LAKE ON MONDAY EVENING...THE SOUTHEAST FLOW WILL INCREASE. A
COLD FRONT WILL SWEEP ACROSS THE LAKE ON TUESDAY BRINGING A WEST TO
NORTHWEST FLOW THROUGH MID WEEK. WINDS OVERNIGHT MAY INCREASE TO
NEAR 20 KNOTS AND WAVES MAY INCREASE TO NEAR 4 FEET OVER THE WESTERN
BASIN. MY INITIAL THINKING IS THAT CONDITIONS WILL REMAIN BELOW
SMALL CRAFT. THE DURATION OF THE STRONGER EASTERLY WINDS ARE ONLY A
FEW HOURS BEFORE IT BECOMES MORE SOUTHEAST. THIS SHOULD NOT ALLOW
THE WAVES TO BUILD ABOVE SMALL CRAFT ADVISORY CONDITIONS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...KEC/KUBINA
SHORT TERM...KUBINA
LONG TERM...GARNET
AVIATION...KIELTYKA
MARINE...GARNET
AREA FORECAST DISCUSSION...UPDATED
NWS PENDLETON OR
1035 PM PDT SUN AUG 10 2014
UPDATED AVIATION DISCUSSION
.UPDATE...THUNDERSTORMS HAVE DEVELOPED IN THE SOUTHERN FRINGE OF
THE FORECAST AREA THIS EVENING WITH THE BULK OF THE ACTIVITY IN
DESCHUTES COUNTY SOUTH OF BEND. THUNDERSTORMS HAVE NOT BEEN
PARTICULARLY STRONG AND APPEAR TO BE WEAKENING AS SUNDOWN
APPROACHES. HOWEVER, THE LATEST RUN OF THE HRRR MODEL SHOWS
ANOTHER BAND OF THUNDERSTORMS ARRIVING IN DESCHUTES COUNTY FROM
THE SOUTH AROUND MIDNIGHT. THUNDERSTORMS ARE SHOWN MOVING AS FAR
NORTH AS NORTHERN JEFFERSON COUNTY A COUPLE OF HOURS LATER SO HAVE
EXPANDED THE AREA OF ISOLATED THUNDERSTORMS OVERNIGHT FURTHER
NORTH. HAVE ALSO ADJUSTED SKY COVER TO MATCH CURRENT TRENDS AND
THE POSSIBLE THUNDERSTORMS LATER TONIGHT. FORECAST IS OTHERWISE IN
GOOD SHAPE. UPDATE WILL BE OUT SHORTLY. PERRY
&&
.AVIATION...06Z TAFS...AN UPPER LEVEL LOW WILL REMAIN OFF THE
CENTRAL CALIFORNIA COAST FOR THE NEXT 24 HOURS. THIS WILL SEND
MOISTURE INTO OUR AREA AND ADD TO THE INSTABILITY DUE TO DAYTIME
HEATING. THUNDERSTORMS ARE WINDING DOWN FOR TONIGHT THOUGH AN
ISOLATED STORM OR TWO REMAINS POSSIBLE AT KRDM AND KBDN AND HAVE
VCTS THROUGH 08Z AT THOSE SITES. BKN-OVC CEILINGS ABOVE 7000 FEET
AGL WILL CONTINUE THERE FOR A FEW HOURS BEFORE PARTIALLY CLEARING
OUT. THE REST OF THE AREA WILL BE CLEAR OVERNIGHT. THUNDERSTORMS
WILL BEGIN DEVELOPING IN CENTRAL OREGON AFTER 20Z AND WILL SPREAD
NORTH ACROSS THE REGION BY 00Z. ALL TAF SITES HAVE VCTS AFTER
20Z-22Z DEPENDING ON THE SITE. STORMS WILL BE HIGH BASED AND DO NOT
EXPECT CEILINGS TO DROP BELOW 7000 FEET AGL. SURFACE WINDS WILL
REMAIN BELOW 12 KTS FOR THE NEXT 24 HOURS EXCEPT AROUND
THUNDERSTORMS. THUNDERSTORMS MAY HAVE GUSTY WINDS TO 40 KTS. PERRY
&&
.PREV DISC... /ISSUED 337 PM PDT SUN AUG 10 2014/
SHORT TERM...TONIGHT THROUGH WEDNESDAY. CUMULUS STARTING TO
FORM OVER THE HIGHER TERRAIN OF CENTRAL AND NORTHEAST OREGON EARLY
THIS AFTERNOON. IF THE TREND CONTINUES SHOULD SEE ISOLATED SHOWERS
AND THUNDERSTORMS DEVELOP LATE AFTERNOON INTO THE EVENING. THIS IS
IN RESPONSE TO A LARGE UPPER LOW JUST OFF THE CALIFORNIA COAST AND
INCREASING INSTABILITY. 18Z NAM INDICATES SOME ACTIVITY COULD
CONTINUE OVERNIGHT FOR CENTRAL OREGON. NORTH OF THIS AREA SKIES
SHOULD REMAIN MOSTLY CLEAR THROUGH THE EVENING AND TONIGHT. THE
UPPER LOW REMAINS NEARLY STATIONARY ALONG THE CALIFORNIA COAST
MONDAY HOWEVER THE UPPER LEVEL FLOW BECOMES MORE SOUTHERLY OVER OUR
FORECAST AREA. THIS SHOULD ALLOW CONVECTION TO MOVE NORTHWARD DURING
THE DAY AND INTO MONDAY NIGHT. MORE ENHANCEMENT FROM THE JET COULD
PRODUCE SOME STRONGER STORMS TOMORROW AS WELL. THE LOW WEAKENS A BIT
AND MOVES NORTHEAST ACROSS THE REGION TUESDAY AND SHOULD BRING MORE
WIDESPREAD SHOWERS AND THUNDERSTORMS. ON WEDNESDAY ANOTHER UPPER LOW
MOVES ACROSS THE PACIFIC NORTHWEST WITH ADDITIONAL SHOWERS AND
STORMS. AS FOR TEMPERATURES MONDAY WILL BE HOT WITH 90S TO NEAR 100.
COOLER TUESDAY WITH 80S TO LOWER 90S. EVEN COOLER WEDNESDAY WITH 70S
AND 80S. 94
LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY NIGHT...A CLOSED UPPER
LEVEL LOW IS PROGGED TO SLOWLY MOVE EAST ACROSS THE AREA WEDNESDAY
NIGHT AND BE MAINLY OUT OF THE AREA BY EARLY SATURDAY MORNING. THIS
WILL RESULT IN A MUCH WETTER PERIOD DURING THE EXTENDED RANGE WITH A
CHANCE OF SHOWERS AND THUNDERSTORMS WEDNESDAY NIGHT THROUGH THURSDAY
NIGHT. GIVEN THE POTENTIAL PROJECTED PRECIPITATION WITH THE SYSTEM
AS IT PASSES THROUGH...THERE IS GOING TO BE SOME FLASH FLOOD
CONCERNS OVER THE NUMEROUS BURN SCARS WITHIN THE CWA IF ANY STORMS
DEVELOP AND TRANSITION OVER THOSE AREAS. THIS WILL NEED TO BE
MONITORED AS THE EVENT APPROACHES. WRAP AROUND MOISTURE MAY LINGER
BEHIND THE SYSTEM TO BRING SOME SHOWERS TO THE NORTHERN BLUE AND
WALLOWA MOUNTAINS EARLY FRIDAY MORNING BEFORE MOISTURE CLEARS OUT OF
THE AREA BY SATURDAY MORNING. A BRIEF SHORTWAVE RIDGE NUDGES INTO
THE AREA SATURDAY AND SUNDAY FOR A BRIEF DRYING TREND BEFORE MORE
MOISTURE AHEAD OF A POTENTIAL SHORTWAVE TROUGH ENCROACHES SUNDAY
EVENING. HIGH TEMPERATURES DURING THE PERIOD WILL BE IN THE MID 70S
TO MID 80S EXCEPT MID 60S TO MID 70S MOUNTAINS ON WEDNESDAY WITH
TEMPERATURES WARMING BACK UP INTO THE MID 70S TO UPPER 80S BY SUNDAY
AFTERNOON. BIEDA
FIRE WX...A LOW PRESSURE SYSTEM OFF THE COAST OF NORTHERN
CALIFORNIA WILL CONTINUE TO BRING MOISTURE FURTHER NORTH INTO THE
REGION EACH DAY. THIS WILL LEAD TO INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS. A RED FLAG WARNING FOR CENTRAL OREGON AND THE
SOUTHERN BLUE AND STRAWBERRY MOUNTAINS IS IN EFFECT STARTING THIS
AFTERNOON AND RUNNING THROUGH TUESDAY EVENING. THE CHANCE OF
THUNDERSTORMS WILL SPREAD NORTH AND EASTWARD ON MONDAY. THEREFORE A
RED FLAG WARNING HAS BEEN ISSUED STARTING MONDAY LATE MORNING AND
RUNNING THROUGH TUESDAY EVENING FOR THE EAST SLOPES OF THE OREGON
AND WASHINGTON CASCADES AND NORTHEAST OREGON MOUNTAINS. A FIRE
WEATHER WATCH REMAINS FOR THE COLUMBIA BASIN FOR THE POTENTIAL OF
THUNDERSTORMS MONDAY EVENING THROUGH TUESDAY. THESE THUNDERSTORMS
WILL START OUT WITH LITTLE TO NO RAINFALL. EXPECT PRECIPITATION
CHANCES TO INCREASE MONDAY AND TUESDAY. A TROUGH OF LOW PRESSURE
WILL MOVE INTO THE REGION TUESDAY INTO WEDNESDAY...WITH BREEZY WINDS
EXPECTED IN THE CASCADE GAPS TUESDAY AND WEDNESDAY AFTERNOONS. THE
POTENTIAL FOR THUNDERSTORMS WILL CONTINUE THROUGH THE MIDWEEK AS THE
TROUGH SLOWLY MOVES THROUGH THE REGION. DMH
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 64 99 70 88 / 0 10 20 30
ALW 66 100 72 90 / 0 10 20 30
PSC 62 102 69 92 / 0 10 20 30
YKM 60 99 71 87 / 0 10 20 30
HRI 60 100 68 91 / 0 10 20 30
ELN 59 99 67 88 / 0 10 20 30
RDM 57 93 61 85 / 20 30 30 40
LGD 57 94 61 86 / 10 30 30 40
GCD 59 95 60 86 / 20 30 30 40
DLS 63 100 70 87 / 0 20 30 30
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING FROM 11 AM MONDAY TO 11 PM PDT TUESDAY ORZ041.
RED FLAG WARNING UNTIL 11 PM PDT TUESDAY ORZ506-509-511.
RED FLAG WARNING FROM 11 AM MONDAY TO 11 PM PDT TUESDAY
ORZ049-050-502-503-507.
FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING
ORZ041-044-503-507-508-510.
RED FLAG WARNING UNTIL 11 PM PDT TUESDAY ORZ505-510.
WA...RED FLAG WARNING FROM 11 AM MONDAY TO 11 PM PDT TUESDAY
WAZ024-520-521.
RED FLAG WARNING FROM 11 AM MONDAY TO 11 PM PDT TUESDAY WAZ030.
FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY EVENING
WAZ024-026>029-521.
&&
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
83/98/83/84
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
739 PM EDT TUE AUG 12 2014
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE AREA TONIGHT. GENERALLY
DRIER AND COOLER CONDITIONS CAN BE EXPECTED FOR THE SECOND HALF OF
THE WEEK. A WARMING TREND WILL SET IN FOR EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
SLOW MOVING FRONTAL ZONE NUDGED INTO MY WESTERN COUNTIES EARLY
THIS EVENING...AND GIVEN STABLE STRATIFICATION FROM A DAY`S WORTH
OF CLOUD COVER AND SHOWERS...ACTIVITY WEAKENED AS IT CROSSED THE
ALLEGHENY CREST. STILL SOME LOCALLY HEAVY RAIN TO CONTEND WITH AND
WE`RE WATCHING CLOSELY FOR AREAS OF TRAINING. EARLIER HRRR HAD
INDICATED HOURLY AMOUNTS IN EXCESS OF 2" AS A POSSIBILITY FROM
PORTIONS OF THE WEST CENTRAL MOUNTAINS EASTWARD INTO CENTRE
COUNTY...BUT MOST RECENT RUN HAS BACKED OFF.
MOST GUIDANCE PROJECTS THE LAST OF THE HEAVIER SHOWERS/STORMS TO
BE PUSHING OFF TO THE E/NE OF THE CWA BY 06Z. SOME WRAP
AROUND/UPSLOPE SHOWERS WILL COME BACK INTO THE NWRN THIRD OF THE
CWA LATER TONIGHT AND LINGER INTO THE MORNING. BUT DRIER AIR AND
GOOD WESTERLY FLOW WILL HELP TO DRY THINGS UP WELL.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
THE MAIN COLD FRONT WILL BE EAST OF THE AREA BY SUNRISE...WITH
THE TRIPLE POINT.
STILL SOME SHOWERS AND STORMS POSSIBLE UNTIL EARLY AFT...UNTIL
THE SECONDARY FRONT MOVES EAST OF THE AREA.
MUCH OF THE AFTERNOON SHOULD BE DRY AND NOT REAL COLD.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
NOT A LOT OF CHANGE FROM YESTERDAY.
THE DEEP UPPER LVL LOW WILL LIKELY BE SLOW TO MOVE OUT BASED
ON 00Z EC LAST NIGHT...TREND THIS SUMMER...AND EXPERIENCE
JET MAX ROTATION AROUND THE UPPER LVL LOW WILL RESULT IN
A CHC OF SHOWERS FOR THU. STILL A CHC FOR FRIDAY...BUT LESS
OF A CHC.
DID KEEP SOME CHC POPS IN FOR SUNDAY...AS 00Z EC SHOWS UPPER
LVL TROUGH DEEPENING MORE. GFS IS FLATTER AND WETTER. ALSO
DECENT WARM ADVECTION.
DID GO DRY SUNDAY NIGHT INTO MONDAY.
SOME CHC OF SHOWERS AND STORMS ON TUE...AS WARM ADVECTION
SETS IN.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
TRACKING SEVERAL AREAS OF CONVECTION THIS EVENING THAT WILL AFFECT
MOST OF THE TAF SITES WITH LOW CIGS AND THUNDERSTORMS THROUGH THE
EVENING HOURS. RESIDUAL MOISTURE AND CYCLONIC FLOW SHOULD KEEP
IFR CIGS OVER MUCH OF THE AREA OVERNIGHT. ALSO KEPT A MENTION OF
SHRA/DZ IN THE WEST. DOWNSLOPE SHOULD HELP EAT UP THE CLOUDS IN
THE SERN HALF TO TWO- THIRDS WED MORNING. BUT JST/BFD WILL STILL
HAVE SCT SHRA FOR MOST OF THE TAF CYCLE.
OUTLOOK...
THU...AFTN SHRA NW. OTHERWISE VFR.
FRI-SUN...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE/MARTIN
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...MARTIN
LONG TERM...MARTIN
AVIATION...ROSS/DANGELO
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
212 AM EDT MON AUG 11 2014
.SYNOPSIS...
A WEAK STATIONARY FRONT WILL REMAIN JUST SOUTH OF OUR REGION THROUGH
MONDAY NIGHT. A SERIES OF LOW PRESSURE CENTERS WILL MOVE EAST ALONG
THE FRONT...MAINTAINING ELEVATED CHANCES OF SHOWERS AND
THUNDERSTORMS UNTIL THEN. A COLD FRONT WILL THEN CROSS THE AREA ON
TUESDAY WITH DRIER AIR MOVING OVER THE AREA IN ITS WAKE.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 145 AM EDT...HIGH PRESSURE CONTINUES TO RIDGE DOWN THE EAST
COAST...THOUGH THE UPPER FLOW IS BECOMING LESS CONFLUENT ABOVE IT
THANKS TO THE TROUGH MOVING INTO THE GREAT LAKES. IT SHOULD WEAKEN
AND MOVE OFFSHORE TODAY. HOWEVER THE INCUMBENT WEDGE IS UNLIKELY TO
GO ANYWHERE THIS MORNING EVEN AS THE HIGH LOSES ITS GRIP ON OUR
REGION. WEAK UPGLIDE WILL CONTINUE BUT THAT APPEARS TO BE BARELY
CAPABLE OF PRODUCING ANYTHING MORE THAN DRIZZLE. THE RAIN BEING
REPORTED BY A HANDFUL OF OBS SITES ATTM SEEMS TO BE FORCED BY
UPSLOPE. VAD WINDS FROM KGSP/KCLT INDICATE LIGHT SELY FLOW IN THE
FEW THSD FT ABOVE THE ELY FLOW WITHIN THE WEDGE. OVERNIGHT POP
TRENDS FOCUS MOSTLY IN THE NC BLUE RIDGE AREA. THE HRRR AND 00Z
HIRES NCEP WRF RUNS BACK UP THE UPSLOPE CONCEPT...ALLOWING CONTINUED
SHOWER DEVELOPMENT IN THAT AREA.
WITH THE ISENTROPIC LIFT BEING UNIMPRESSIVE AND WITH DRYING
OCCURRING ALOFT...THE LOW STRATUS WILL BEGIN TO LIFT ONCE INSOLATION
GETS UNDERWAY...BUT SKIES WILL REMAIN NEARLY OVERCAST OVER MOST OF
THE CWFA TODAY. THIS IS PARTICULARLY TRUE OF THE NW NC PIEDMONT
WHERE THE WEDGE IS PROGGED TO REMAIN STRONGEST. POPS WILL INCREASE
WITH THE HEATING...THE INSTABILITY LOOKING MUCH MORE CAPABLE OF
DRIVING PRECIP THAN THE LINGERING UPGLIDE. THUNDER CHANCES DO RETURN
FOR MOST OF THE AREA BY LATE AFTN...PER CONSENSUS OF GFS/NAM
PRODUCING NEAR 1000 J/KG OF CAPE. SHEAR WILL BE SUFFICIENT TO ALLOW
LOOSE ORGANIZATION INTO CLUSTERS IF TSRA DO BREAK OUT...BUT SEVERE
THREAT IS QUITE LOW. PWATS REMAIN NEAR 2 INCHES SO LOCALLY HEAVY
RAIN IS OF SOME CONCERN HOWEVER.
MORE DETAILS TO COME WITH FULL PACKAGE DISCUSSION AT 330 AM.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
AS OF 245 PM SATURDAY...EARLY TUESDAY...A MID LEVEL TROF IS EXPECTED
TO AMPLIFY WEST OF THE FORECAST AREA. THE GFS INDICATES THAT TWO S/W
WILL RIPPLE ACROSS THE REGION BY 18Z TUESDAY. H85 WINDS WILL REMAIN
WSW DURING THE MORNING...THEN VEER FROM THE WEST DURING THE
AFTERNOON. I WILL FORECAST 30 TO 40 POPS DURING THE PASSAGE OF THE
MORNING S/W. 30 TO 40 POPS MAY VERIFY WELL DURING THE AFTERNOON AS
CAPES POOL ABOVE 1000 J/KG AHEAD OF A COLD FRONT. USING A BLEND OF
PREFERRED MOS...I WILL FORECAST HIGHS OF 80 WITHIN THE MTN VALLEYS
TO MID TO UPPER 80S EAST OF I-85. TUESDAY NIGHT...THE COLD FRONT
WILL SLIDE ACROSS THE CWA...ENDING ANY MENTIONABLE POPS. DRY HIGH
PRESSURE WILL BUILD OVER THE REGION THROUGH THE DAY. I WILL FORECAST
SINGLE DIGIT POPS AND LOWER AFTERNOON HUMIDITY. HIGH TEMPERATURES
WILL LIKELY RANGE VERY CLOSE TO TUES VALUES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 2 PM SUNDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON
THURSDAY WITH BROAD UPPER TROFFING CENTERED TO OUR NORTH AND UPPER
RIDGING OVER THE EASTERN ROCKIES. THE LONG RANGE MODELS INDICATE
THAT THE TROF WILL BEGIN TO LIFT OVER THE WEEKEND AND BY NEW DAY 7
ON SUNDAY...THE UPPER PATTERN WILL HAVE FLATTENED OUT OVER THE SE
REGION.
AT THE SFC...DRY HIGH PRESSURE IS EXPECTED TO BE SPREADING OVER THE
CAROLINAS BY THE START OF THE PERIOD. AN AREA OF NEAR SFC
CONVERGENCE WILL LIKELY SETUP JUST TO OUR SOUTH EARLY IN THE PERIOD
BUT IS EXPECTED TO REMAIN SOUTH OF THE CWFA. ITS LOOKING LIKE THE
BERMUDA HIGH WILL BEGIN TO STRENGTHEN AGAIN BY THE END OF THE PERIOD
AND WE WILL RETURN TO A MORE TYPICAL SLY FLOW REGIME BEYOND DAY 7.
NO OTHER SIGNIFICANT PATTERN CHANGES ARE EXPECTED THRU THE MEDIUM RANGE.
AS FOR THE SENSIBLE FCST...WE SHOULD BE MOSTLY DRY FOR
THURS...FRI...AND SAT WITH ONLY SOME BRIEF SLIGHT CHANCE POPS FOR
THE HIGHER TERRAIN FRI AND SAT AFTERNOON/EVENING. WITH THE RETURN OF
MORE MOIST SLY FLOW EXPECTED BY SUN...POPS WILL INCREASE TO A MORE
TYPICAL SLIGHT CHANCE TO SOLID CHANCE PATTERN TYPICAL OF LATE
SUMMERTIME. TEMPS WERE NOT CHANGED MUCH WITH VALUES GRADUALLY
WARMING THRU THE PERIOD BUT LIKELY REMAINING JUST BELOW CLIMATOLOGY
FOR MID AUGUST.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AT KCLT...IN CONTINUING WEAK WEDGE REGIME...IFR CIGS ARE A NEAR
CERTAINTY UNTIL A FEW HRS AFTER SUNRISE. PERIODS OF DRIZZLE AND A
FEW SHOWERS WILL BE NEARBY EARLY THIS AM. SAID PRECIP COULD CAUSE
IFR VSBY AT TIMES. THE CONTINUALLY WEAKENING WEDGE AND INSOLATION
SHOULD PERMIT CIGS TO LIFT TO MVFR BY MIDDAY...BUT THOSE CIGS WILL
LAST INTO TONIGHT. SUFFICIENT INSTABILITY SHOULD BE REALIZED TO
ALLOW A FEW TSRA TO FORM THIS AFTN...EACH OF WHICH WILL BE CAPABLE
OF TORRENTIAL RAIN. EASTERLY WINDS WILL PREVAIL...MAINLY BEING SOUTH
OF EAST AFTER DAYBREAK.
ELSEWHERE...MORE OR LESS AS AT KCLT THOUGH WITH MOST OF THE PRECIP
OCCURRING NEAR THE NC BLUE RIDGE. KHKY WILL BE MOST IMPACTED WITH
VSBY RESTRICTIONS. IFR CIGS WILL LAST OVERNIGHT WITH PATCHY MVFR TO
IFR FOG ALSO LIKELY...AS WELL AS THE PATCHY DRIZZLE. THE WEAKENING
INFLUENCE OF THE WEDGE MEANS PRECIP CHANCES TODAY WILL BECOME MORE A
FUNCTION OF INSTABILITY AND UPSLOPING...BUT THE BEST OVERALL CHANCE
IS OVER NC WHERE ALL THREE ARE A FACTOR TO SOME DEGREE. VCSH/VCTS
USED SPARINGLY WITH PROB30S ASSIGNED DURING THE PEAK CHANCE PERIODS.
WITHIN THE WEDGE...KHKY WILL SEE MAINLY NE WINDS TODAY WITH THE
OTHER SITES PREVAILING SELY. ANY CIGS AT SUNSET WILL LIKELY PERSIST
THRU 06Z.
OUTLOOK...SOME RESTRICTIONS ARE LIKELY WITHIN LOW CLOUDS AND OCNL
SHOWERS THROUGH AT LEAST MONDAY EVENING AND PERHAPS INTO TUESDAY
WHEN A COLD FRONT WILL PASS THROUGH. DRIER AND VFR CONDITIONS SHOULD
RETURN IN ITS WAKE AND CONTINUE THROUGH LATE WEEK.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT MED 76% MED 75% HIGH 87% MED 79%
KGSP MED 79% HIGH 83% HIGH 84% HIGH 96%
KAVL HIGH 86% HIGH 80% HIGH 89% HIGH 81%
KHKY HIGH 82% HIGH 88% HIGH 87% MED 79%
KGMU HIGH 80% HIGH 84% HIGH 84% HIGH 96%
KAND MED 70% MED 75% MED 67% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...WIMBERLEY
SHORT TERM...NED
LONG TERM...JPT
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
1003 AM EDT MON AUG 11 2014
.DISCUSSION...
JUST ISOLATED SHOWERS OVER THE NORTHERN HALF OF THE AREA
NOW...EXPECTING AFTERNOON HEATING TO GET ISOLATED CONVECTION
GOING...AND WILL SEE HOW WELL THE SMALL COMPLEX OVER SRN KY HOLDS
TOGETHER FOR THS AFTERNOON. HRRR SUGGEST MORE CONVECTION IN THE
WESTERN AREAS IN THE EARLY AFTERNOON. FORECAST LOOKS ON TRACK...SO
NO UPDATE TO THE ZONE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 86 71 88 66 / 50 60 40 20
KNOXVILLE MCGHEE TYSON AIRPORT, TN 84 71 86 65 / 60 50 50 20
OAK RIDGE, TN 83 70 86 64 / 60 60 40 20
TRI CITIES AIRPORT, TN 81 66 83 61 / 60 70 60 40
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
GM
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1129 PM CDT SUN AUG 10 2014
.UPDATE...AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 859 PM CDT SUN AUG 10 2014/
DISCUSSION...00Z UPPER AIR ANALYSIS THIS EVENING PLACES A 500 MB
MID LEVEL TROUGH AXIS LOCATED ACROSS THE UPPER MIDWEST AND
PORTIONS OF MISSOURI AND EAST KANSAS. REGIONAL WSR-88D RADAR
TRENDS INDICATE INCREASED COVERAGE OF SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS PORTIONS OF SOUTH CENTRAL/SOUTHEAST MISSOURI
AND NORTH CENTRAL ARKANSAS THIS EVENING IN RESPONSE TO THIS MID
LEVEL SHORTWAVE TROUGH. LATEST MESOANALYSIS YIELDS SURFACE BASED CAPE
VALUES AROUND BETWEEN 2000-2500 J/KG...SURFACE BASED LI/S AROUND
-6. LATEST SHORT TERM TRENDS INCLUDING THE 11/00Z HRRR RUN
INDICATE A POTENTIAL FOR UPSTREAM SHOWERS AND THUNDERSTORMS TO
MOVE INTO PORTIONS OF NORTHEAST ARKANSAS AND THE MISSOURI
BOOTHEEL IN THE NEXT FEW HOURS AND SPREAD ACROSS THE REMAINDER OF
THE MID SOUTH OVERNIGHT. WILL MAKE ADJUSTMENTS TO RAIN CHANCES TO
ACCOUNT FOR SHORT TERM CONVECTIVE TRENDS AND ADJUST ANY OTHER
ELEMENTS AS NEEDED.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
PREV DISCUSSION... /ISSUED 624 PM CDT SUN AUG 10 2014/
UPDATE...AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 316 PM CDT SUN AUG 10 2014/
A STATIONARY FRONT CURRENTLY STRETCHES ACROSS SOUTHERN MISSOURI
THIS AFTERNOON. THIS FRONT WILL SLIDE INTO THE MIDSOUTH ON MONDAY
AS A COLD FRONT. SHOWERS AND THUNDERSTORMS ARE BEGINNING TO FIRE
ALONG THE FRONT. THESE SHOWERS AND THUNDERSTORMS MAY DEVELOP INTO
A LINE LATER THIS EVENING. THE LINE MAY BEGIN TO PUSHING INTO
NORTHEAST ARKANSAS LATE TONIGHT INTO THE EARLY MORNING HOURS.
MEANWHILE...EXPECT DIURNAL SHOWERS AND THUNDERSTORMS THAT ARE CURRENTLY
OCCURRING NEAR THE TENNESSEE RIVER AND ACROSS NORTHWEST
MISSISSIPPI TO DIE OUT DURING THE EARLY EVENING HOURS. ANOTHER
HUMID NIGHT IS EXPECTED ACROSS THE MIDSOUTH. LOWS WILL BE IN THE
LOWER TO MID 70S.
EXPECT SOME LINGERING CONVECTION MONDAY MORNING ACROSS NORTHEAST
ARKANSAS...THE MISSOURI BOOTHEEL AND WEST TENNESSEE FROM IS LEFT
OF LINE THAT MOVES IN DURING THE OVERNIGHT HOURS AHEAD OF THE
APPROACHING COLD FRONT. REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS
WILL OCCUR ALONG THE COLD FRONT MONDAY AFTERNOON. SOME STORMS MAY
BECOME SEVERE PRODUCING LARGE HAIL...DAMAGING WINDS...AND FLASH
FLOODING. HIGHS WILL BE IN THE UPPER 80S TO LOWER 90S.
THE COLD FRONT WILL CONTINUE TO PUSH SOUTHWARD MONDAY NIGHT.
LINGERING CHANCES FOR SHOWERS AND THUNDERSTORMS WILL OCCUR MAINLY
ACROSS WEST TENNESSEE NEAR THE MISSISSIPPI BORDER INTO NORTH
MISSISSIPPI. COOLER AND DRIER AIR MAY BEGIN TO FILTER INTO THE
MISSOURI BOOTHEEL...NORTHEAST ARKANSAS...AND NORTHWEST TENNESSEE
DURING THE EARLY MORNING HOURS.
TUESDAY THROUGH FRIDAY WILL BE BEAUTIFUL ACROSS THE MIDSOUTH. SFC
HIGH PRESSURE WILL MOVE INTO THE AREA FROM THE UPPER MIDWEST. EXPECT
COOLER TEMPERATURES WITH LOW HUMIDITY AND PLENTY OF SUNSHINE.
HIGHS WILL BE IN THE 80S WITH LOWS IN THE MID 50S TO MID 60S.
PATTERN BECOMES UNSETTLED ONCE AGAIN BY NEXT WEEKEND AS SFC HIGH
SHIFTS EAST. WEAK NORTHWEST FLOW ALOFT WILL ALLOW A COUPLE OF
DISTURBANCES TO MOVE THROUGH THE REGION SETTING OFF ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS. HUMIDITY WILL ALSO RETURN TO
THE AREA.
KRM
&&
.AVIATION...06Z TAF CYCLE
NO THUNDERSTORMS ARE EXPECTED AT ANY TAF SITE FOR THE NEXT SEVERAL
HOURS. EXPECT MAINLY VFR CONDITIONS THROUGH THE PERIOD ALTHOUGH
SOME MVFR CIGS AND VIS ARE POSSIBLE LATE TONIGHT/EARLY TOMORROW.
AN UPPER LEVEL DISTURBANCE AND COLD FRONT WILL APPROACH THE
REGION LATER TONIGHT AND MONDAY MORNING. AS A RESULT EXPECT
SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP THOUGH TIMING IS A
PROBLEM SO OPTED TO CONTINUE VCTS FOR NOW STARTING LATER TONIGHT.
EXPECT SOME LIGHT FOG AT KMKL AND KTUP LATER TONIGHT. WINDS WILL BE
GENERALLY LIGHT FROM THE SW/WSW.
STORMS SHOULD COME TO AN END DURING THE EARLY TO MIDDLE PART OF THE
AFTERNOON AT JBR....MEM...THEN MKL AS THE FRONT PASSES. WINDS WILL
SHIFT FROM THE NORTHWEST. UNLESS THE FRONT STALLS...IT SHOULD
MOVE THROUGH TUP AFTER SUNSET.
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
SEE FORECAST DISCUSSION FOR MORNING UPDATE.
DISCUSSION...
THE NEXT COLD FRONT THAT IS FORECASTED TO MOVE INTO THE AREA THIS
EVENING IS CURRENTLY LOCATED IN NORTH TEXAS AND WILL CONTINUE TO
SLOWLY MOVE SOUTHWARDS THIS AFTERNOON. A HAND ANALYSIS OF 12Z
MAPS AT 850 AND 700MB THIS MORNING REVEALS TWO BOUNDARIES NEAR
KCLL WITH THE BEST MOISTURE JUST EAST OF THE AREA. AT 250MB A WEAK
UPPER LEVEL LOW WAS ANALYZED JUST SOUTH OF THE AREA WHICH IS
HELPING TO PROVIDE DIFFLUENT WINDS IN NORTHERN TEXAS THIS MORNING.
THE LOW IS FORECASTED TO CONTINUE TO PUSH SOUTH THIS AFTERNOON
ALLOWING THE UPPER LEVEL DIFFLUENCE ALSO TO SAG SOUTHWARDS. HIGH
RES HRRR AND RAP HAVE INITIALIZED THE BEST THIS MORNING AND FIRE
CONVECTION IN TWO AREAS. THE FIRST BEING A SEA BREEZE PUSHING
INLAND AND ALONG A COLD FRONT THAT IS PUSHING SOUTHWARDS. IT
SHOULD BE NOTED THE HRRR AND RAP FIRE WIDESPREAD CONVECTION IN OUR
NORTHERN ZONES THIS AFTERNOON. WAS TEMPTED TO GO LIKELY FOR POPS
BUT HAVE HELD OFF FOR NOW. FORECAST FOR THIS AFTERNOON REVEAL
PWATS NEAR 2.00" WITH K INDEX VALUES AROUND 40. FORECAST SOUNDINGS
ALSO SHOW AN INVERTED V THIS AFTERNOON. THIS COULD LEAD TO SOME
GUSTY WINDS IN STRONGER STORMS. IF CONVECTION GETS MORE WIDESPREAD
THIS AFTERNOON THIS WILL ALSO HOLD DOWN HIGH TEMPERATURES. FOR NOW
HAVE ONLY MADE MINOR TWEAKS TO GRIDS. 23
PREV DISCUSSION... /ISSUED 357 AM CDT MON AUG 11 2014/
DISCUSSION...
COOL FRONT SITUATED IN S OKLAHOMA EARLY THIS MORNING SHOULD MAKE
GRADUAL SWD PROGRESS & CLOSER TO N PARTS OF SE TX LATER THIS
EVENING. WITH AID OF DAYTIME HEATING EXPECT SHRA/TSTM COVERAGE
ALONG THE FRONT TO INCREASE THIS AFTN AND APPROACH N PARTS OF THE
CWA LATER IN THE DAY. FURTHER SOUTH & TOWARD THE COAST...ANTICIPATE
ISO/SCT PRECIP DEVELOPMENT ALONG THE SEABREEZE SIMILAR TO PAST
COUPLE DAYS.
THINGS GET INTERESTING THIS EVENING AND OVERNIGHT. REALLY NEED TO
KEEP AN EYE ON REGION BETWEEN THE SEABREEZE (OR REMNANTS OF) AND
THE CONVECTION DRIFTING IN FROM THE NORTH. SHOULD THESE EVENTUALLY
COLLIDE/MERGE...AND SEVERAL MODELS SUGGEST IT`S QUITE POSSIBLE...THREAT
OF LOCALIZED HEAVY RAINFALL REALLY INCREASES. GOES SOUNDER DATA SHOWING
PW`S AROUND 2.2" ACROSS THE REGION WHICH IS ABOUT 2 STANDARD DEVIATIONS
ABOVE NORMAL. WITH FAIRLY WEAK STEERING FLOW IN PLACE...LOCALIZED
BOUNDARY COLLISIONS WILL ENHANCE LIFT AND THREAT OF STORMS GOING
NEARLY STATIONARY INCREASES. ATTM HIGHER THREAT OF THIS OCCURRING
WILL PROBABLY BE SOMEWHERE ROUGHLY BETWEEN I-10 AND SOMERVILLE-
TRINITY LINE BETWEEN 7PM-MIDNIGHT.
FRONT AND ASSOCIATED PRECIP SHOULD MAKE GRADUAL SOUTHWARD
PROGRESS OVERNIGHT AND TOWARD THE COAST TUE. EXACTLY WHERE IT ENDS
UP IS IN QUESTION, BUT MAJORITY OF 00Z RUNS WITH EXCEPTION OF
NAM12 ACTUALLY PUSH IT *BRIEFLY* OFFSHORE LATE TUE NIGHT & WED
MORNING. SCT CONVECTION WILL REMAIN POSSIBLE ALONG/S OF THE FRONT.
LOWERED POPS ACROSS MOST AREAS NORTH OF I-10 TUESDAY AND INTO
MIDWEEK AS A CONSIDERABLY DRIER AIRMASS MOVES INTO THE REGION.
ANYONE UP FOR DEWPOINTS IN THE 50S/60S & HUMIDITIES 30-40%? HOW
ABOUT A FEW LOWS IN THE UPPER 60S IN THE NORTH HALF? LOOKING MORE
AND MORE LIKE A DECENT POSSIBILITY INTO MIDWEEK.
A GRADUAL RETURN BACK TO AUGUST REALITY EXPECTED DURING THE 2ND
HALF OF THE WEEK AND INTO THE WEEKEND AS THE FRONT WASHES OUT. ONSHORE
WINDS RESUME AS LEE SIDE PRESSURES FALL. MOISTURE LEVELS INCREASE
AGAIN WITH TYPICAL ISO SEABREEZE PRECIP. 47
MARINE...
LIGHT ONSHORE WINDS TODAY SHOULD BECOME MORE VARIABLE TUES/WEDS AS A
WEAK SFC FRONT SAGS INTO THE REGION. THIS BOUNDARY IS FCST TO SLOWLY
MAKE ITS WAY TO THE UPPER TX COASTLINE LATE MON/EARLY TUES...BUT NOT
EXPECTED TO MOVE INTO THE NEARSHORE WATERS AT THIS TIME. THE PROXIM-
ITY OF THIS SYSTEM SHOULD GENERATE PERIODS OF SHRAS/TSRAS FROM EARLY
TUES THROUGH WEDS. THIS BOUNDARY IS PROGGED TO WASH OUT THURS...WITH
THE NEXT STORM SYSTEM MOVING INTO THE STATE AND DEEPENING AROUND THE
SAME TIME. THIS SHOULD PRODUCE STRENGTHENING ONSHORE WINDS BY FRI...
AND ON INTO THE WEEKEND. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 95 74 96 70 96 / 50 50 10 10 10
HOUSTON (IAH) 95 75 94 73 95 / 30 50 30 20 20
GALVESTON (GLS) 93 81 89 80 92 / 20 50 40 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...23
AVIATION/MARINE...42
SEE FORECAST DISCUSSION FOR MORNING UPDATE.
&&
.DISCUSSION...
THE NEXT COLD FRONT THAT IS FORECASTED TO MOVE INTO THE AREA THIS
EVENING IS CURRENTLY LOCATED IN NORTH TEXAS AND WILL CONTINUE TO
SLOWLY MOVE SOUTHWARDS THIS AFTERNOON. A HAND ANALYSIS OF 12Z
MAPS AT 850 AND 700MB THIS MORNING REVEALS TWO BOUNDARIES NEAR
KCLL WITH THE BEST MOISTURE JUST EAST OF THE AREA. AT 250MB A WEAK
UPPER LEVEL LOW WAS ANALYZED JUST SOUTH OF THE AREA WHICH IS
HELPING TO PROVIDE DIFFLUENT WINDS IN NORTHERN TEXAS THIS MORNING.
THE LOW IS FORECASTED TO CONTINUE TO PUSH SOUTH THIS AFTERNOON
ALLOWING THE UPPER LEVEL DIFFLUENCE ALSO TO SAG SOUTHWARDS. HIGH
RES HRRR AND RAP HAVE INITIALIZED THE BEST THIS MORNING AND FIRE
CONVECTION IN TWO AREAS. THE FIRST BEING A SEA BREEZE PUSHING
INLAND AND ALONG A COLD FRONT THAT IS PUSHING SOUTHWARDS. IT
SHOULD BE NOTED THE HRRR AND RAP FIRE WIDESPREAD CONVECTION IN OUR
NORTHERN ZONES THIS AFTERNOON. WAS TEMPTED TO GO LIKELY FOR POPS
BUT HAVE HELD OFF FOR NOW. FORECAST FOR THIS AFTERNOON REVEAL
PWATS NEAR 2.00" WITH K INDEX VALUES AROUND 40. FORECAST SOUNDINGS
ALSO SHOW AN INVERTED V THIS AFTERNOON. THIS COULD LEAD TO SOME
GUSTY WINDS IN STRONGER STORMS. IF CONVECTION GETS MORE WIDESPREAD
THIS AFTERNOON THIS WILL ALSO HOLD DOWN HIGH TEMPERATURES. FOR NOW
HAVE ONLY MADE MINOR TWEAKS TO GRIDS. 23
&&
.PREV DISCUSSION... /ISSUED 357 AM CDT MON AUG 11 2014/
DISCUSSION...
COOL FRONT SITUATED IN S OKLAHOMA EARLY THIS MORNING SHOULD MAKE
GRADUAL SWD PROGRESS & CLOSER TO N PARTS OF SE TX LATER THIS
EVENING. WITH AID OF DAYTIME HEATING EXPECT SHRA/TSTM COVERAGE
ALONG THE FRONT TO INCREASE THIS AFTN AND APPROACH N PARTS OF THE
CWA LATER IN THE DAY. FURTHER SOUTH & TOWARD THE COAST...ANTICIPATE
ISO/SCT PRECIP DEVELOPMENT ALONG THE SEABREEZE SIMILAR TO PAST
COUPLE DAYS.
THINGS GET INTERESTING THIS EVENING AND OVERNIGHT. REALLY NEED TO
KEEP AN EYE ON REGION BETWEEN THE SEABREEZE (OR REMNANTS OF) AND
THE CONVECTION DRIFTING IN FROM THE NORTH. SHOULD THESE EVENTUALLY
COLLIDE/MERGE...AND SEVERAL MODELS SUGGEST IT`S QUITE POSSIBLE...THREAT
OF LOCALIZED HEAVY RAINFALL REALLY INCREASES. GOES SOUNDER DATA SHOWING
PW`S AROUND 2.2" ACROSS THE REGION WHICH IS ABOUT 2 STANDARD DEVIATIONS
ABOVE NORMAL. WITH FAIRLY WEAK STEERING FLOW IN PLACE...LOCALIZED
BOUNDARY COLLISIONS WILL ENHANCE LIFT AND THREAT OF STORMS GOING
NEARLY STATIONARY INCREASES. ATTM HIGHER THREAT OF THIS OCCURRING
WILL PROBABLY BE SOMEWHERE ROUGHLY BETWEEN I-10 AND SOMERVILLE-
TRINITY LINE BETWEEN 7PM-MIDNIGHT.
FRONT AND ASSOCIATED PRECIP SHOULD MAKE GRADUAL SOUTHWARD
PROGRESS OVERNIGHT AND TOWARD THE COAST TUE. EXACTLY WHERE IT ENDS
UP IS IN QUESTION, BUT MAJORITY OF 00Z RUNS WITH EXCEPTION OF
NAM12 ACTUALLY PUSH IT *BRIEFLY* OFFSHORE LATE TUE NIGHT & WED
MORNING. SCT CONVECTION WILL REMAIN POSSIBLE ALONG/S OF THE FRONT.
LOWERED POPS ACROSS MOST AREAS NORTH OF I-10 TUESDAY AND INTO
MIDWEEK AS A CONSIDERABLY DRIER AIRMASS MOVES INTO THE REGION.
ANYONE UP FOR DEWPOINTS IN THE 50S/60S & HUMIDITIES 30-40%? HOW
ABOUT A FEW LOWS IN THE UPPER 60S IN THE NORTH HALF? LOOKING MORE
AND MORE LIKE A DECENT POSSIBILITY INTO MIDWEEK.
A GRADUAL RETURN BACK TO AUGUST REALITY EXPECTED DURING THE 2ND
HALF OF THE WEEK AND INTO THE WEEKEND AS THE FRONT WASHES OUT. ONSHORE
WINDS RESUME AS LEE SIDE PRESSURES FALL. MOISTURE LEVELS INCREASE
AGAIN WITH TYPICAL ISO SEABREEZE PRECIP. 47
MARINE...
LIGHT ONSHORE WINDS TODAY SHOULD BECOME MORE VARIABLE TUES/WEDS AS A
WEAK SFC FRONT SAGS INTO THE REGION. THIS BOUNDARY IS FCST TO SLOWLY
MAKE ITS WAY TO THE UPPER TX COASTLINE LATE MON/EARLY TUES...BUT NOT
EXPECTED TO MOVE INTO THE NEARSHORE WATERS AT THIS TIME. THE PROXIM-
ITY OF THIS SYSTEM SHOULD GENERATE PERIODS OF SHRAS/TSRAS FROM EARLY
TUES THROUGH WEDS. THIS BOUNDARY IS PROGGED TO WASH OUT THURS...WITH
THE NEXT STORM SYSTEM MOVING INTO THE STATE AND DEEPENING AROUND THE
SAME TIME. THIS SHOULD PRODUCE STRENGTHENING ONSHORE WINDS BY FRI...
AND ON INTO THE WEEKEND. 41
AVIATION...
NO REAL CHANGE FROM THE FCST OF PERSISTENCE WITH THE 12Z SET OF TAFS
THROUGH THIS AFTN. STILL EXPECTING A SOMEWHAT ACTIVE SEABREEZE AS WE
REMAIN IN A FAIRLY TROPICAL AIRMASS. CHANGES EXPECTED TO COME DURING
THE OVERNIGHT/EARLY TUES MORNING TIME FRAME AS A WEAK FRONTAL BOUND-
ARY MOVES INTO THE REGION FROM THE NORTH. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 95 74 96 70 96 / 50 50 10 10 10
HOUSTON (IAH) 95 75 94 73 95 / 30 50 30 20 20
GALVESTON (GLS) 93 81 89 80 92 / 20 50 40 30 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...23
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
355 PM CDT MON AUG 11 2014
.SHORT TERM...
TONIGHT...FORECAST CONFIDENCE MEDIUM.
THUNDERSTORMS DEVELOPED ALONG THE LAKE BREEZE CONVERGENCE OVER
EASTERN WI EARLY THIS AFTERNOON. THIS AREA OF STORMS ARE EXPANDING
BUT NOT MOVING...SO EXPECT AN INCH OF RAIN THERE THROUGH LATE
AFTERNOON.
MEANWHILE...VORTICITY ADVECTION WITHIN AN UPPER LEVEL TROUGH IS
DROPPING SOUTHEAST THROUGH WI THIS AFTERNOON. THE UPPER TROUGH WILL
CLOSE OFF AND STALL OVER SOUTHERN WI THIS EVENING. IT IS TAKING A
WHILE FOR CONVECTION TO DEVELOP ALONG THE COLD FRONT/ LEADING EDGE
OF VORT MAX/ OVER SOUTH CENTRAL WI...BUT THERE IS FINALLY A BROKEN
LINE DEVELOPING AT 230 PM NEAR MADISON AND THE DELLS THIS AFTERNOON.
I AM EXPECTING THIS LINE TO FILL AS IT GETS EAST OF MADISON AND
ESPECIALLY IN SOUTHEAST WI WHEN IT INTERACTS WITH THE LAKE BREEZE
BOUNDARY. THE HRRR MODEL SEEMS TO HAVE A GOOD HANDLE ON THIS.
PRECIPITABLE WATER VALUES ARE FAIRLY HIGH AROUND 1.5 INCHES. THE
UPPER LEVEL FLOW IS WEAK. THE SHEAR IS WEAK AND THERE IS 500 TO 1000
J/KG OF SURFACE BASED...TALL/SKINNY CAPE. THIS MEANS THE
THUNDERSTORMS WILL BE PULSY AND EFFICIENT RAIN PRODUCERS. WE CANNOT
RULE OUT SMALL HAIL WITH THE STRONGER STORMS...BUT THIS WILL BE THE
MINORITY. THE MAIN THREAT THIS AFTERNOON WILL BE PERIODS OF HEAVY
RAIN WHICH COULD CAUSE SOME URBAN FLOODING.
AFTER THE MAIN LINE OF STORMS MOVES THROUGH WITH THE
FRONT...CLEARING THE LAKESHORE AROUND 2-3Z...EXPECT ADDITIONAL
SHOWERS TO SPREAD BACK IN ACROSS SOUTH CENTRAL AND SOUTHEAST WI
DURING THE REST OF THE OVERNIGHT. THESE WILL BE ASSOCIATED WITH THE
UPPER TROUGH CLOSING OFF OVER THE WESTERN GREAT LAKES AND THE MAIN
VORTICITY MAX MOVING THROUGH SOUTHERN WI. THIS IS ALSO COINCIDENT
WITH UPPER DIVERGENCE IN THE LEFT EXIT REGION OF AN UPPER JET.
EXPECTING LOW CLOUDS TO SPREAD INTO SOUTHERN WI OVERNIGHT AS THE
RAIN SHOWERS RE-DEVELOP WITH THE UPPER LOW. THIS WILL KEEP TEMPS
WARMER...SO MIN TEMPS WILL BE AROUND 60 FOR MOST AREAS.
TUESDAY...FORECAST CONFIDENCE MEDIUM.
THE UPPER TROUGH DOES NOT SHIFT EAST UNTIL LATER TUESDAY MORNING.
LINGERED SMALL CHANCE OF RAIN SHOWERS OVER SOUTHEAST WI THROUGH
MIDDAY. THE CLOUDS WILL LINGER LONGER IN THE EAST AS WELL...SO KEPT
MAX TEMPS IN THE LOWER 70S THERE...AND MID 70S INLAND.
THE DRY AIR WILL GRADUALLY WORK ITS WAY INTO SOUTHERN WI MIDDAY
TUESDAY. THE MODELS ARE NOT IN AGREEMENT ABOUT EXACTLY WHEN THIS
WILL HAPPEN.
EXPECTING GUSTY NORTH-NORTHWEST WINDS TUESDAY MORNING AS THE SURFACE
PRESSURE GRADIENT INCREASES AS LOW PRESSURE STRENGTHENS OVER LOWER
MICHIGAN.
TUESDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE HIGH.
A LARGE POLAR TROUGH WILL RESIDE OVER FAR ERN ONTARIO AND WRN
QUEBEC CANADA THROUGH THURSDAY WITH NWLY FLOW ALOFT OVER WI. VERY
WEAK VORTICITY MAXIMUMS WILL LIKELY MOVE ACROSS THE AREA AND THE
MODELS DO DEPICT A VERY WEAK SFC TROUGH TO SHIFT SOUTH THROUGH THE
AREA WED AND WED NT. WEAK LOW LEVEL WARM ADVECTION IS EXPECTED
AHEAD OF THE TROUGH BUT THE COMBINATION OF A FAIRLY DRY AIRMASS
AND LITTLE TO NO LIFT SUPPORTS A DRY FCST. SCT-BKN MID LEVEL
CLOUDS ARE LIKELY WED AND WED NT BUT STILL ENOUGH SUNSHINE FOR
TEMPS TO WARM TO SEASONAL NORMALS ON WED. HIGH PRESSURE TO THEN
SETTLE OVER THE WRN GREAT LAKES FOR THU. DRY ENELY WINDS WILL
PREVAIL WITH PLEASANT TEMPS AND HUMIDITY.
.LONG TERM...
FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM.
HIGH PRESSURE WILL MOVE EWD ON FRI WITH LGT SLY WINDS DEVELOPING.
HEAT AND HUMIDITY WILL INCREASE THROUGH THE WEEKEND INTO EARLY
NEXT WEEK AS A SHORTWAVE TROUGH AND SFC LOW APPROACHES. SLIGHT
CHANCES OF TSTORMS ARE FORECAST FOR THE WEEKEND WITH BETTER
CHANCES OF TSTORMS BY MONDAY.
&&
.AVIATION/00Z TAFS/...
A LINE OF SHOWERS AND THUNDERSTORMS IS DEVELOPING ALONG A COLD FRONT
IN SOUTH CENTRAL WISCONSIN AND WILL CONTINUE TO FILL IN AND EXPAND
AS IT TRACKS EASTWARD THROUGH SOUTHERN WI LATER THIS AFTERNOON INTO
THE EVENING. EXPECT MVFR CIGS/VSBYS WITH SHOWERS AND STORMS...WITH
SOME IFR VSBYS IN HEAVIER DOWNPOURS.
SHOWERS ARE EXPECTED TO RE-DEVELOP THIS EVENING AND LINGER THROUGH
TUESDAY MORNING AS THE SURFACE TROUGH/FRONT STALLS OVER SOUTHEAST
WI. THERE IS STILL UNCERTAINTY ABOUT HOW WIDESPREAD AND HOW FAR WEST
THESE WILL BE. EXPECT IFR STRATUS BEHIND COLD FRONT LATE TONIGHT AND
TUE MORNING AS WELL. LOOK FOR GUSTY NNW WINDS TUESDAY MORNING.
&&
.MARINE...
INCREASING NORTHERLY WINDS IN THE WAKE OF A COLD FRONT EARLY TUESDAY
MORNING WILL BUILD HIGH WAVES ON TUESDAY. A SMALL CRAFT ADVISORY
WAS ISSUED WITH THE 930 AM NSH UPDATE.
&&
.BEACHES...
A MODERATE TO HIGH SWIM RISK IS EXPECTED ON TUESDAY. GUSTY NORTHERLY
WINDS WILL BUILD HIGH WAVES DURING THE DAY TUESDAY. HIGHEST WAVES
WILL BE TOWARD THE OPEN WATERS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 7 AM TO 9 PM CDT TUESDAY FOR
LMZ644>646.
SMALL CRAFT ADVISORY FROM 4 AM TO 9 PM CDT TUESDAY FOR LMZ643.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...MRC
TUESDAY NIGHT THROUGH MONDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
234 PM CDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 233 PM CDT MON AUG 11 2014
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING SHORTWAVE TROUGH
SPINNING ACROSS NORTHEAST MINNESOTA AND NORTHWEST WISCONSIN. THE
11.12Z GFS/NAM AND 11.15Z RAP INDICATE DECENT FORCING IN ASSOCIATION
WITH SHORTWAVE TROUGH. THIS IS PRODUCING SHOWERS AND ISOLATED
THUNDERSTORMS MAINLY ACROSS EASTERN MINNESOTA AND MUCH OF
WISCONSIN PER LATEST MOSAIC RADAR.
MAIN CONCERNS TONIGHT ARE DIMINISHING TRENDS OF PRECIPITATION AND
LOW CLOUDS ACROSS THE FORECAST AREA. THE 11.12Z GFS/NAM INITIALIZE
SHORTWAVE TROUGH AND MOISTURE FIELDS WELL PER THE LATEST
VISIBLE/WATER VAPOR SATELLITE IMAGERY. THE 11.12Z GFS/NAM SHOW THE
FORCING TO EXIT THE FORECAST AREA AROUND 06Z TUESDAY AND ASSOCIATED
MOISTURE WITH SHORTWAVE TROUGH BY 12Z TUESDAY. HAVE TRENDED
PRECIPITATION CHANCES AND SKY COVER FOR THIS.
SURFACE RIDGE OVER THE DAKOTAS WILL BUILD INTO MINNESOTA AND
WESTERN WISCONSIN TUESDAY. SUBSIDENCE UNDERNEATH SURFACE HIGH WILL
ALLOW FOR DRY WEATHER CONDITIONS AND BELOW NORMAL TEMPERATURES
ACROSS THE FORECAST AREA.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 233 PM CDT MON AUG 11 2014
WITH SURFACE RIDGE OVERHEAD ACROSS FORECAST AREA...THE 11.12Z
NAM/GFS ARE INDICATING AN INVERSION TO DEVELOP AFTER 06Z WEDNESDAY
PER BUFKIT SOUNDINGS. DUE TO WINDS AROUND 5 KNOTS THROUGH 1500
FEET. EXPECT THE FORMATION OF FOG OVER CENTRAL WISCONSIN AND IN
RIVER VALLEYS WEDNESDAY MORNING.
WEDNESDAY...FORECAST AREA REMAINS UNDER NORTHWEST FLOW ALOFT. THE
11.12Z GFS/NAM SHOW WEAK IMPULSE EMBEDDED IN THE NORTHWEST FLOW
ALOFT TO MOVE OVER PARTS OF THE FORECAST AREA. BUFKIT SOUNDINGS FROM
THE 11.12Z GFS/NAM INDICATE STEEP LOW LEVEL LAPSE RATES AND SOME
INSTABILITY ALOFT DURING THE DAY ACROSS CENTRAL WISCONSIN. THE
11.12Z NAM MORE ROBUST WITH THE INSTABILITY AND LOW LEVEL LAPSE
RATES THAN THE GFS. CANNOT RULE OUT AN ISOLATED SHOWER OR
THUNDERSTORM ACROSS CENTRAL WISCONSIN WEDNESDAY AFTERNOON. FOR
NOW...WILL CONTINUE WITH MENTION OF SPRINKLES OVER THIS AREA.
THE COMBINATION OF THE MAIN AXIS OF ISENTROPIC LIFT WEST OF FORECAST
AREA AND SHORTWAVE RIDGING BUILDING INTO THE REGION THURSDAY...WILL
PROVIDE DRY WEATHER CONDITIONS ACROSS THE AREA. HAVE REMOVED SMALL
PRECIPITATION CHANCES OVER THE WESTERN FORECAST AREA.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES THURSDAY NIGHT INTO
MONDAY. THE 11.12Z GFS/GEM/ECMWF ARE IN GOOD AGREEMENT BREAKING DOWN
UPPER LEVEL TROUGH OVER THE EASTERN UNITED STATES THIS WEEKEND AND
DEVELOP WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED
STATES. BIGGEST DIFFERENCE BETWEEN THE MODELS IS TIMING AND
PLACEMENT OF SHORTWAVE TROUGHS EMBEDDED IN THE WEST TO EAST ZONAL
FLOW SATURDAY INTO MONDAY. THE 11.12Z GFS/ECMWF INDICATE DECENT
MOISTURE TRANSPORT AND CONVERGENCE WITH SHORTWAVE TROUGH PUSHING
INTO THE UPPER MIDWEST AND GREAT LAKES REGION SUNDAY INTO MONDAY.
DEPENDING ON TIMING/PLACEMENT OF SURFACE FEATURES/SHORTWAVE
TROUGH...PRECIPITATION CHANCES LOOK REASONABLE ACROSS MUCH OF THE
FORECAST AREA SATURDAY INTO MONDAY. HOWEVER...CONFIDENCE IS LOW ON
THE EXACT TIMING AND PLACEMENT OF THE SURFACE FEATURES/SHORTWAVE
TROUGHS TRACKING INTO THE UPPER MIDWEST AND GREAT LAKES REGION
DURING THIS PERIOD. TEMPERATURES FRIDAY INTO EARLY NEXT WEEK WILL
BE NEAR OR SLIGHTLY BELOW NORMAL ACROSS FORECAST AREA...WITH HIGHS
GENERALLY AROUND 80 DEGREES INTO THE LOWER TO MIDDLE 80S
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1231 PM CDT MON AUG 11 2014
LOW PRESSURE TRACKING OVER THE REGION THIS AFTERNOON WILL BRING A
FEW SHOWERS AND MVFR CONDITIONS TO THE AREA. THE SHOWERS WILL STAY
EAST OF KRST...IMPACTING KLSE THROUGH THE EARLY TO MID AFTERNOON
HOURS. THE CLOUDS WILL BE SLOW TO CLEAR LATE THIS AFTERNOON INTO
THIS EVENING AS HIGH PRESSURE GRADUALLY BUILDS IN FROM THE WEST.
PLAN ON MVFR CEILINGS LINGERING AT THE TAF SITES INTO THIS EVENING
WITH CLOUD BASES OF 1500 TO 2500 FT. THE CLOUDS WILL EVENTUALLY
CLEAR LATE THIS EVENING INTO THE OVERNIGHT HOURS. LOOK FOR THE
CLEARING TO MOVE INTO KRST AFTER 01Z THEN INTO KLSE AROUND 07Z. A
TIGHT GRADIENT OVER THE AREA BETWEEN THE LOW AND THE HIGH WILL
KEEP WINDS UP THROUGH THE NIGHT PROMOTING MIXING AND KEEPING
VALLEY FOG FROM FORMING AT KLSE. WINDS WILL INCREASE AGAIN
TOMORROW MORNING AS MIXING INCREASES. PLAN ON WIND SPEEDS OF 13 TO
15 KTS WITH GUSTS AROUND 22 KTS POSSIBLE. ALSO...SCATTERED CUMULUS
LOOK TO DEVELOP TOMORROW MORNING WITH CLOUD BASES IN THE 2-3 KFT
RANGE. THESE BASES SHOULD GRADUALLY RISE LATE IN THE MORNING INTO
THE AFTERNOON HOURS AS DEEPER MIXING OCCURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1137 AM CDT MON AUG 11 2014
.UPDATE...
SUNSHINE OVER SOUTH CENTRAL WI WILL HELP BUILD SOME CAPE TO SUPPORT
THUNDERSTORMS THIS AFTERNOON ALONG A SURFACE TROUGH/COLD FRONT. KEPT
LIKELY POPS IN THE FORECAST UPDATE AND WILL CONTINUE TO REFINE THE
TIMING BASED ON THE HRRR AND RAP MODELS. THE FORECAST SOUNDINGS HAVE
A LITTLE DRIER PROFILE THAN PREVIOUS RUNS...WHICH WOULD MEAN PULSE-
TYPE THUNDERSTORMS RATHER THAN WIDESPREAD HEAVY RAIN. HOPEFULLY THE
STORMS WILL MOVE SLOW ENOUGH TO GIVE EVERYONE SOME MUCH-NEEDED RAIN.
AREAS WEST OF MADISON WILL END UP WITH THE LEAST AMOUNT OF RAIN.
THE SHOWERS AND THUNDERSTORMS ALONG THE FRONT WILL MARCH ALONG AT A
STEADY PACE THIS AFTERNOON WITH A FRONT AND BACK EDGE. THEN PERIODS
OF RAIN WILL ENSUE OVERNIGHT AS THE SURFACE AND UPPER TROUGH STALLS
OVER SOUTHEAST WI. I WILL WAIT FOR THE 12Z MESO MODELS TO COME IN
BEFORE MAKING A DECISION ABOUT HOW FAR WEST TO EXPAND THE
CHANCE/LIKELY POPS FOR THE OVERNIGHT/TUE MORNING PERIOD.
SUNSHINE IN WESTERN FORECAST AREA IS LEADING TO HIGHER TEMPS THAN
FORECAST...SO BUMPED UP THE MAX TEMPS A BIT.
&&
.AVIATION/18Z TAFS/...
A LINE OF SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG A COLD FRONT
IN SOUTHWEST WISCONSIN AND TRACK EASTWARD THROUGH SOUTHERN WI LATER
THIS AFTERNOON INTO THE EVENING. EXPECT MVFR CIGS/VSBYS WITH SHOWERS
AND STORMS...WITH SOME IFR VSBYS IN HEAVIER DOWNPOURS.
SHOWERS ARE EXPECTED TO RE-DEVELOP THIS EVENING AND LINGER THROUGH
TUESDAY MORNING AS THE SURFACE TROUGH/FRONT STALLS OVER SOUTHEAST
WI. THERE IS STILL UNCERTAINTY ABOUT HOW WIDESPREAD THESE WILL BE.
EXPECT SOME IFR STRATUS BEHIND COLD FRONT LATE TONIGHT AND TUE
MORNING AS WELL.
&&
.MARINE...
INCREASING NORTHERLY WINDS IN THE WAKE OF A COLD FRONT EARLY TUESDAY
MORNING WILL BUILD HIGH WAVES ON TUESDAY. A SMALL CRAFT ADVISORY
WAS ISSUED WITH THE 930 AM NSH UPDATE.
&&
.PREV DISCUSSION... /ISSUED 451 AM CDT MON AUG 11 2014/
TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM.
RADAR ESTIMATES AND RAIN GAGE DATA INDICATE 0.75 INCH TO 1.2 INCH
HAVE FALLEN OVER SE WISCONSIN WITH SHOWERS AND A FEW THUNDERSTORMS
THAT FORMED AHEAD OF SHORT WAVE THAT IS PUSHING EAST THROUGH NRN IL.
THIS AREA IS MOVING EAST WITH WAVE...BUT LINGERING SURFACE
TROUGHINESS WILL KEEP ENOUGH CONVERGENCE OVER AREA FOR SCATTERED
SHOWERS THROUGH MID-MORNING OVER THE FAR SE CORNER...THOUGH
POTENTIAL FOR HEAVY DOWNPOURS HAS ENDED FOR THE TIME BEING.
NOT MUCH CURRENTLY HAPPENING UPSTREAM AHEAD OF MAIN SHORT WAVE
TROUGH AND COLD FRONT...BUT MODELS ALL SHOW DEVELOPMENT WITH GROWING
INSTABILITY WITH DIURNAL HEATING AND INCREASING Q-VECTOR CONVERGENCE
AND FRONTOGENETIC RESPONSE TO SHORT WAVE AND FRONT. 0-6KM SHEAR
REMAINS WEAK SO LITTLE CHANCE FOR STRONG SUSTAINED UPDRAFTS NEEDED
FOR SEVERE...BUT SUFFICIENT CAPE AND PWS OF 1.5 TO 1.8 INCHES FOR
SOME DECENT DOWNPOURS. WILL NOT ISSUE A FLASH FLOOD WATCH AS DRY
CONDITIONS AND STORM MOTION IS SUFFICIENT TO PRECLUDE WIDESPREAD
FLOODING...THOUGH CLOSE MONITORING WILL BE NEEDED FOR POSSIBLE
LOCALIZED URBAN AND SMALL STREAM PROBLEMS.
MAIN PUSH OF PRECIPITATION MOVES EAST TOWARD CONSOLIDATING SURFACE
LOW OVER LOWER MICHIGAN...BUT LINGERING CYCLONIC FLOW AND MID-UPPER
FORCING KEEPS CHANCE POPS IN THE FAR EAST INTO TUESDAY MORNING.
TUESDAY - CONFIDENCE...MEDIUM
MID LEVEL TROUGH AXIS WILL BE ON THE WAY OUT OF SOUTHEAST WI
EARLY IN THE DAY. HOWEVER CYCLONIC FLOW LINGERS AND MODELS SHOW A
FAIRLY STRONG LOW WITH POTENTIAL FOR MORE WRAPAROUND THAN WAS
SUGGESTED IN PRIOR RUNS. MODELS SHOW PRECIP IN THE EASTERN CWA SO
HAVE PUT SOME MORNING POPS IN TO ACCOUNT FOR THIS POTENTIAL. LOW
LEVEL THERMAL TROUGH AND BREEZY CONDITIONS CAN BE EXPECTED WITH
THIS COOLER AIRMASS SETTLING IN. LOW LEVEL RH PROGS SUGGEST SOME
CLEARING AS THE DAY WEARS ON THOUGH POTENTIAL FOR CLOUD COVER TO
LINGER LONGER PER THE NAM GIVEN SOME CYCLONIC FLOW AND THERMAL
TROUGH.
WEDNESDAY THROUGH FRIDAY - CONFIDENCE...MEDIUM
ALL IN ALL THIS IS SHAPING UP TO BE A DRY PERIOD WITH HIGH
PRESSURE IN CONTROL. THE PROGS HAVE BEEN HINTING AT SOME LIGHT
PRECIP WEDNESDAY WITH A WEAK FRONT TRYING TO DROP INTO THE AREA.
THE SOUNDINGS LOOK CAPPED OFF WITH RESPECT TO A FAVORABLE PARCEL
TRAJECTORY...WHILE THE SUPERBLEND POPS ARE IN THE SINGLE DIGITS.
WILL STICK WITH THE DRY FORECAST FOR NOW BUT EURO AND GFS ARE
HINTING AT SOME SPOTTY LIGHT PRECIP. DEBATED ON ADDING SPRINKLES
BUT DECIDED TO LEAVE OUT.SO QUICK SHOT OF A RENEWED THERMAL TROUGH
THURSDAY WITH 925 TEMPS RETURNING TO NEAR 20C BY FRIDAY. GFS DOES
SHOW SOME LIGHT WAA QPF FRIDAY BUT IT LOOKS TOO QUICK AND IS SET
UP AS AN OUTLIER AT THIS POINT. WILL LEAN WITH THE CONSENSUS OF
THE GEM AND ECMWF WITH HIGH PRESSURE IN CONTROL.
SATURDAY AND SUNDAY - CONFIDENCE...LOW
ECMWF CONTINUES TO BE THE DRIEST SOLUTION WITH MORE PRONOUNCED
MID LEVEL RIDGING BUILDING UP BEFORE SHORTWAVE ENERGY ARRIVES
SUNDAY. MEANWHILE THE GFS AND TO A LESSER EXTENT THE GEM...SHOW A
FLATTER RIDGE WITH STILL SOME TIMING AND STRENGTH ISSUES. THE GFS
HAS BEEN CONSISTENTLY TRYING TO HAVE THE WETTER REGIME KICKING IN
SOONER WHILE THE ECMWF HAS BEEN CONSISTENTLY DRY. HOPEFULLY SOME
CONSENSUS COMES SOON BUT STILL A WAYS OFF. A LITTLE BETTER
AGREEMENT FOR PRECIP COME SUNDAY BUT STILL VARYING SOLUTIONS ON
DETAILS AND STRENGTH OF APPROACHING UPPER SUPPORT. FOR NOW WILL
RIDE WITH THE ALLBLEND POPS GIVEN THE DIVERGING MODEL SOLUTIONS.
AVIATION/12Z TAFS/...
SOME LIMITED AREAS OF IFR/LIFR CIGS IN THE FAR SOUTHEAST BEHIND
INITIAL ROUND OF SHOWERS AND THUNDERSTORMS. OTHERWISE EXPECT VFR
CONDITIONS THROUGH THE REST OF THE MORNING. LOOKING FOR AREA OF
UPSTREAM SHOWERS AND THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT TO
BECOME MORE WIDESPREAD...MOVING INTO WESTERN FORECAST AREA LATE
THIS MORNING/EARLY AFTERNOON AND REACHING THE EASTERN TAF SITES
MID-AFTERNOON. EXPECT MVFR CIGS/VSBYS WITH SHOWERS AND
STORMS...WITH SOME IFR VSBYS IN HEAVIER DOWNPOURS. SOME IFR
STRATUS ALONG AND JUST BEHIND COLD FRONT...BUT WILL KEEP POST-
FRONTAL CIGS AT MVFR LEVELS FOR NOW.
MARINE...INCREASING NORTH WINDS AS LOW PRESSURE CONSOLIDATES AND
DEEPENS OVER LOWER MICHIGAN WILL BUILD HIGH WAVES ON TUESDAY. A
SMALL CRAFT ADVISORY WILL BE LIKELY AS WAVE HEIGHTS UP TO 5 FEET
ARE EXPECTED WITH THE FAVORABLE FETCH.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 7 AM TO 9 PM CDT TUESDAY FOR
LMZ644>646.
SMALL CRAFT ADVISORY FROM 4 AM TO 9 PM CDT TUESDAY FOR LMZ643.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...REM
TUESDAY THROUGH SUNDAY...COLLAR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1207 AM CDT MON AUG 11 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 233 PM CDT SUN AUG 10 2014
MAIN SHORT TERM CONCERN IS ON PRECIPITATION CHANCES.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO BRITISH COLUMBIA AND OVER
THE EASTERN GREAT LAKES...WHILE TROUGHING WAS DROPPING SOUTH THROUGH
SOUTH CENTRAL CANADA. TWO OTHER SHORTWAVE TROUGHS WERE EVIDENT OVER
NORTHERN MN AND SOUTHERN IOWA. BOTH OF THESE SHORTWAVE TROUGHS WERE
PRODUCING SHOWERS AND SOME THUNDERSTORMS...BUT SO FAR THEY HAVE
STAYED WEST OF THE FORECAST AREA. THIS IS DUE TO HIGH PRESSURE
REMAINING IN PLACE OVER THE GREAT LAKES...PROVIDING A FLOW OF DRY
AIR INTO THE REGION. GOES PRECIPITABLE WATER IMAGERY DEPICTED THE
DIFFERENCE IN MOISTURE WELL...RANGING FROM 1-1.25 INCHES OVER THE
FORECAST AREA TO 1.5-1.75 INCHES FROM NORTH CENTRAL MN INTO WESTERN
IOWA AND MISSOURI. THE DRIER AIRMASS OVER THE FORECAST AREA HAS LED
TO A MOSTLY SUNNY DAY...AMD WITH 850MB TEMPS OF 12-14C ON 12Z
RAOBS...TEMPERATURES HAVE CLIMBED INTO THE UPPER 70S/LOW 80S. IN THE
SEA LEVEL PRESSURE FIELD...MAIN ITEM TO NOTE IS A COLD FRONT
TRACKING ACROSS WESTERN MN AHEAD OF THE SOUTH CENTRAL CANADA UPPER
TROUGH. ANOTHER SIGNIFICANT DRY AIRMASS WAS COMING IN BEHIND IT WITH
PRECIPITABLE WATER VALUES OF 0.5-0.75 INCHES ACROSS NORTH DAKOTA.
OVER THE NEXT 24 HOURS...THE TROUGHING OVER SOUTH CENTRAL CANADA IS
PROGGED TO DROP THROUGH THE FORECAST AREA. AS THE TROUGHING
APPROACHES...THE STREAM OF HIGHER PRECIPITABLE WATER VALUES JUST OFF
TO OUR WEST WILL MOVE INTO THE FORECAST AREA...BRINGING THE
POTENTIAL FOR PRECIPITATION. HOWEVER...FORCING MECHANISMS FOR
PRECIPITATION ARE A BIT PROBLEMATIC. FOR TONIGHT...THAT SHORTWAVE
TROUGH OVER NORTHERN MN IS PROGGED TO PROGRESS TOWARDS LAKE
SUPERIOR...WHILE THE SHORTWAVE TROUGH OVER IOWA HEADS DOWN INTO
MISSOURI AND SOUTHERN ILLINOIS. THUS...THESE SHORTWAVES SPLIT AROUND
THE REGION. MODEL QPF PROGS REFLECT THIS WELL. PERHAPS SOME SHOWERS
TRAILING SOUTH OF THE NORTHERN MN SHORTWAVE...AIDED BY DAYTIME
HEATING...WILL MAKE IT INTO NORTHWEST SECTIONS OF THE FORECAST AREA.
THIS IS EVIDENT ON CURRENT RADAR IMAGERY. THUS...HAVE MAINTAINED
SOME LOW PRECIPITATION CHANCES.
HEADING INTO MONDAY...PRECIPITATION CHANCES LOOK A LITTLE
BETTER...PRIMARILY ACROSS WISCONSIN AS THE MAIN TROUGHING COMES
THROUGH AT PEAK HEATING. ITS INTERESTING TO NOTE THAT THE SURFACE
COLD FRONT SHOULD COME THROUGH TONIGHT...BUT THE MOISTURE REALLY
DOESNT GET SCOURED OUT UNTIL THE MAIN TROUGHING MOVES IN. WITH
GOOD MODEL AGREEMENT FOR SHOWERS AND STORMS TO FIRE ACROSS
WISCONSIN IN THE LATE MORNING AND AFTERNOON...HAVE KEPT
PRECIPITATION CHANCES UP IN THE 60-70 RANGE. ONE THING WE WILL
HAVE TO WATCH IS SOME OF THE 12Z HIRES MODELS...ARW/NMM/SPCWRF-
NMM...SUGGEST PRECIPITATION COULD INITIATE JUST EAST OF THE
FORECAST AREA AND STAY TO THE EAST. WEST OF THE MS RIVER...CLOUDS
THAT MOVE IN TONIGHT ARE LIKELY TO CLEAR AS THE LOWER PRECIPITABLE
WATER VALUES ADVECT IN.
NOT ANTICIPATING ANYTHING SEVERE WITH THE STORMS ON MONDAY. ALTHOUGH
EQUILIBRIUM LEVELS ARE UP NEAR 30000 FT...CAPE PROFILE OVERALL IS
QUITE SKINNY. 0-6KM SHEAR IS LESS THAN 25 KT AND WARM CLOUD DEPTHS
ARE AROUND 3500 M. IF ANYTHING...WE WILL HAVE A COUPLE OF HEAVY RAIN
PRODUCERS.
INCREASING CLOUDS AND HIGHER PRECIPITABLE WATER TONIGHT SHOULD
RESULT IN A WARMER NIGHT TONIGHT. COOLEST SPOT LIKELY TO BE IN
CENTRAL WI WHERE CLOUDS/MOISTURE ARRIVE LAST. CLOUDS WILL BE A BIT
OF AN ISSUE ON MONDAY FROM WARMING...BUT ENOUGH SUN SHOULD FILTER
THROUGH PLUS CLEARING WEST OF MS RIVER LATER IN THE DAY TO ALLOW FOR
HIGHS IN THE 70S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 233 PM CDT SUN AUG 10 2014
STRONG DRYING AND SUBSIDENCE ARE ON TRACK TO COME INTO THE FORECAST
AREA MONDAY EVENING...PUSHING ANY LINGERING PRECIPITATION QUICKLY
OFF TO THE EAST AND CAUSING SKIES TO CLEAR OUT. PRECIPITABLE WATER
VALUES FALLING TO 0.5-0.75 INCHES BY 12Z TUESDAY WOULD BE FAVORABLE
FOR A GOOD RADIATIONAL COOLING NIGHT...BUT A PERSISTENT NORTHWEST
BREEZE SHOULD HELP A BIT FROM ALLOWING TEMPERATURES TO COMPLETELY
TANK.
TUESDAY THROUGH WEDNESDAY FEATURES GRADUALLY RISING 500MB HEIGHTS AS
UPPER TROUGHING DEVELOPS OVER THE PACIFIC NORTHWEST...PUSHING THE
UPPER RIDGING THERE EASTWARD AND THE NEW TROUGHING OVER THE FORECAST
AREA EASTWARD. SUBSIDENCE FROM THESE RISING 500MB HEIGHTS SHOULD
HELP TO KEEP THE FORECAST AREA DRY. HOWEVER...LATE WEDNESDAY...BOTH
THE 10.12Z GFS AND NAM DEPICT SOME LIGHT QPF MOSTLY NORTH OF I-90.
10.12Z ECMWF HAS SOME ISOLATED LIGHT QPF...MOSTLY NORTH OF I-90.
10.12Z CANADIAN ALSO DEPICTS SOME LIGHT QPF BUT SOUTH OF I-90. THIS
QPF IS A RESULT OF A WARM ADVECTION PATTERN DEVELOPING...WITH
ISENTROPIC LIFT/800-700MB MOISTURE TRANSPORT INITIATING PRECIPITABLE
BELOW THE 500MB SUBSIDENCE. CONCERNED THE GFS/NAM MAY BE OVERLY
WET...ESPECIALLY THE GFS...BUT WITH THE SIGNAL THERE HAVE INCLUDED A
MENTION OF SPRINKLES ALONG/NORTH OF I-90. TEMPERATURES TUESDAY
SHOULD BOUNCE WELL INTO THE 70S...FOLLOWED BY GOOD RADIATIONAL
COOLING AT NIGHT AS A SURFACE RIDGE SETTLES IN. COULD SEE SOME
VALLEY/RADIATIONAL FOG EARLY WEDNESDAY MORNING AS WELL. SLIGHTLY
WARMER 850MB TEMPS ON WEDNESDAY COMBINED WITH MORNING SUN SHOULD
HELP GIVE A COUPLE DEGREE BOOST TO HIGHS COMPARED TO TUESDAY.
IN THE EXTENDED RANGE...GOOD MODEL AGREEMENT EXISTS OF THE PACIFIC
NORTHWEST TROUGH LIFTING OUT AND TRACKING EAST...ALLOWING THE UPPER
RIDGE DOWNSTREAM EVENTUALLY TO MOVE OVER THE FORECAST AREA FOR THE
WEEKEND. THIS 500MB FLOW PATTERN SUGGESTS PERSISTENT WARM ADVECTION.
09.12Z/10.00Z ECMWF AND 10.12Z GFS IN FACT SUGGEST A BRIEF SURGE OF
HEAT TO COME INTO THE AREA ON SUNDAY. HOWEVER...THE NEW 10.12Z HAS
COMPLETELY WENT AWAY FROM THIS...DUE TO A SHORTWAVE TROUGH DIGGING
SOUTH THROUGH THE PLAINS WHICH BLOCKS THE HEAT FROM ARRIVING ON
SUNDAY. MOST DAYS WE SHOULD SEE HIGHS IN THE UPPER 70S TO PERHAPS AT
MOST MID 80S. ON THE PRECIPITATION SIDE OF THINGS...ITS POSSIBLE
THAT MID-LEVEL SHOWER/SPRINKLE STUFF FROM WEDNESDAY AFTERNOON
PERSISTS THROUGH FRIDAY. THE LOCATION LOOKS TO SHIFT TO MOSTLY WEST
OF THE MS RIVER AND MAY HAVE A FEW MORE SHOWERS WITH IT.
THEREFORE...DO HAVE SOME 20-30 PERCENT CHANCES. FRIDAY NIGHT THROUGH
THE WEEKEND IS NOW UP IN THE AIR AFTER THE 10.12Z ECMWF CAME IN.
PREVIOUSLY IT APPEARED A BETTER SHOT FOR SHOWERS AND STORMS WOULD
COME FRIDAY NIGHT AND SATURDAY AHEAD OF THE HEAT SURGE...AND AGAIN
LATE SUNDAY AS THE PACIFIC NORTHWEST TROUGH APPROACHED. HOWEVER...
THE NEW ECMWF HAS THE ENTIRE REGION UNDER HIGH PRESSURE AND DRY
CONDITIONS. HAVE SPLIT THE DIFFERENCE FOR NOW WHICH RESULTS IN 20-40
PERCENT CHANCES...MAYBE A 50 THERE ON SUNDAY. IF THE ECMWF IS RIGHT
WITH THIS SHORTWAVE DIVING THROUGH THE PLAINS...THE WEEKEND WILL
NEED TO BE DRIED OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1207 AM CDT MON AUG 11 2014
SHORT WAVE ENERGY MOVING INTO ONTARIO PROVIDENCE WILL DRIVE SURFACE
COLD FRONT ACROSS AREA TODAY. TIMING FOR ANY INSTABILITY ALONG FRONT
WILL NOT FAVOR MUCH IN THE WAY OF RAIN THREATS AT EITHER TAF SITE SO
MAIN FOCUS IS POST-FRONTAL MVFR CEILINGS THAT WILL ADVECT IN LATER
TODAY. WILL HOLD THOSE IN A FEW HOURS ALONG WITH INCREASING WINDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...SHEA/WELVAERT
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1124 PM CDT SUN AUG 10 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 228 PM CDT SUN AUG 10 2014
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE
HIGH PRESSURE STRETCHING FROM THE WESTERN GREAT LAKES TO NORTHEAST
NORTH AMERICA WHILE A COLD FRONT IS DROPPING SOUTHEAST OVER THE
NORTHERN GREAT PLAINS. A WEAK AREA OF LOW PRESSURE IS SPINNING OVER
CENTRAL MINNESOTA AHEAD OF THE FRONT...AND COMBINED WITH WEAK
SHORTWAVE ENERGY...IS PRODUCING SHOWERS FROM JUST WEST OF DULUTH TO
SOUTHWEST MINNESOTA. OTHER SPOTTIER SHOWERS ARE POPPING UP IN THE
MOISTURE RETURN OVER SOUTHERN AND CENTRAL LAKE MICHIGAN. MOST OF
THE MESO MODELS KEEP THESE LIGHT SPOTTY SHOWERS OR SPRINKLES
OFFSHORE OVER THE LAKE. BUT AS THE FRONT MOVES INTO THE REGION LATE
TONIGHT AND MONDAY...TIMING OF SHOWERS AND THUNDERSTORMS IS THE MAIN
FORECAST CONCERN.
TONIGHT...A SHORTWAVE TROUGH DROPPING SOUTHEAST OUT OF SOUTH-CENTRAL
CANADA WILL PUSH A COOL FRONT INTO NORTHWEST WISCONSIN LATE. AHEAD
OF THIS FRONT...LOW AND MID-LEVEL WINDS WILL SWING TO THE SOUTH AND
ADVECT MOISTURE FROM ILLINOIS AND INDIANA. A FEW SHOWERS FROM THIS
MOISTURE ARE PROJECTED TO REMAIN OVER THE LAKE. AMPLE CLOUD COVER
SHOULD ALSO ARRIVE WITH THE FRONT AS A WEAK AREA OF LOW PRESSURE
MOVES INTO CENTRAL WISCONSIN LATE. PROGGED SOUNDINGS INDICATE A
MID-LEVEL DRY WEDGE OVER CENTRAL AND NORTH-CENTRAL WISCONSIN ERODING
LATE TONIGHT WHEN A MID-LEVEL THETAE AXIS MOVES INTO THAT PART OF
THE STATE. WILL RAMP UP PRECIP CHANCES AFTER 09Z WHEN THE COLUMN
BECOMES MORE SATURATED AND FORCING MARGINALLY INCREASES.
OTHERWISE...SLOWED DOWN THE CHANCE OF PRECIP THIS EVENING DUE TO THE
PRESENCE OF DRY AIR. LOW TEMPS SHOULD BE SEVERAL DEGREES WARMER DUE
TO THE INCREASING CLOUD COVER...AND WENT WITH TEMPS RANGING FROM
THE UPPER 50S NORTH OT LOWER 60S SOUTH.
MONDAY...THE SHORTWAVE AND COLD FRONT WILL GRADUALLY MOVE ACROSS
WISCONSIN. WITH DAYTIME HEATING...THE SREF INCREASES PRECIP CHANCES
DRAMATICALLY IN THE 15Z-18Z PERIOD OVER CENTRAL AND NORTH-CENTRAL
WISCONSIN...AND THEN SPREAD THE HIGHER PRECIP CHANCES INTO NORTHEAST
WISCONSIN AFTER MIDDAY. THIS LOOKS REASONABLE. TOUGH TO GET AN
ESTIMATE ON POTENTIAL INSTABILITY SINCE PROGGED SOUNDINGS LOOK
CONVECTIVELY MODIFIED...BUT A ROUGH ESTIMATE IS BETWEEN 500-1000
J/KG OF ML CAPE. BUT 0-6KM BULK SHEARS ARE ONLY AROUND 25 KTS AND
THINK FORCING IS TOO WEAK TO GENERATE MUCH OF A SEVERE THREAT. A
FEW STORMS COULD PRODUCE GUSTY WINDS TO 40-50 MPH AND SMALL HAIL.
MOSTLY CLOUDY AND MORE HUMID WITH HIGHS NEAR 70 NORTH TO AROUND 80
SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 228 PM CDT SUN AUG 10 2014
RATHER STABLE MEAN LONGWAVE PATTERN FOR MOST OF THE EXTENDED WITH
NOTABLE TROUGHS SITUATED ON BOTH COASTS AND RIDGE OVER THE
INTER-MOUNTAIN WEST EXTENDING INTO CANADA. THE WESTERN GREAT LAKES
WILL REMAIN UNDER THE INFLUENCE OF SURFACE HIGH PRESSURE BENEATH
NORTHWESTERLY FLOW ALOFT. PATTERN OFFERS LITTLE OPPORTUNITY FOR
SUBSTANTIAL RAINFALL FOR MOST OF THE WORK WEEK. SEASONABLY WARM
TEMPERATURES WITH COMFORTABLE DAYTIME HUMIDITIES...AND COOL NIGHTS
WILL BE THE RULE.
EARLY IN THE EXTENDED...DEEPENING UPPER TROUGH OVER THE GREAT
LAKES REGION MONDAY NIGHT WILL CONTINUE TO SWING EAST DURING THE
DAY ON TUESDAY. IN GENERAL...THE MODELS IN FAIRLY GOOD AGREEMENT
ON OVERALL TIMING OF BACK EDGE OF BROKEN BAND OF SHOWERS AND
ISOLATED THUNDERSTORMS MONDAY EVENING. USING A BLENDED MODEL QPF
SUGGESTS THAT PRECIPITATION SHOULD BE EAST OF THE FORECAST AREA BY
06Z TUESDAY.
IN THE WAKE OF THE DEPARTING SURFACE LOW SITUATED NEAR LAKE HURON
TUESDAY MORNING...EXPECT FAIRLY DECENT NORTHERLY BOUNDARY LAYER
FLOW TO PERSIST AT LEAST FOR THE FIRST HALF OF THE DAY OVER THE
FORECAST AREA. GRADIENT SHOULD RELAX DURING THE AFTERNOON WITH
DIMINISHING WIND AND CLEARING SKIES. WITH THE CLOUDY START...COLD
ADVECTION...AND CORE OF COOLEST 850 TEMPS IN THE 8 TO 10 DEGREE
CELSIUS RANGE OVER THE AREA...DAYTIME HIGHS WILL BE THE COOLEST OF
THE WEEK...MAINLY IN THE LOW TO MID 70S.
DAYTIME HIGHS SHOULD MODERATE QUICKLY WEDNESDAY WITH READINGS
AROUND NORMAL FOR MIDDLE OF AUGUST. WEAK COLD FRONT DROPPING SOUTH
DURING THE DAY ON WEDNESDAY MAY BRING A FEW MORE CLOUDS AND
PERHAPS A SPRINKLE SOMETIME DURING THE DAY. DO NOT EXPECT MUCH
MORE THAN THAT GIVEN PALTRY MOISTURE AND FORCING.
HIGH PRESSURE REMAINS IN CONTROL THURSDAY AND FRIDAY WITH NEAR
NORMAL TEMPERATURES.
LATEST GUIDANCE WOULD ALSO SUGGEST SATURDAY WILL REMAIN DRY WITH
HINTS OF A CONFLUENT UPPER-LEVEL FLOW AND SURFACE RIDGE AXIS
PERSISTING OVER THE AREA.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1123 PM CDT SUN AUG 10 2014
VFR MID TO HIGH LEVEL CLOUDS AHEAD OF A WEAK COLD
FRONT WILL CONTINUE TO THICKEN OVERNIGHT. SCATTERED SHOWERS WITH
AREAS OF MVFR CIGS WILL SPREAD OVER THE NORTHWEST HALF OF THE
STATE LATE OVERNIGHT...AND THEN OVER THE REST OF THE AREA ON
MONDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ESB
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1125 AM MDT MON AUG 11 2014
.UPDATE...
ISSUED AT 935 AM MDT MON AUG 11 2014
NO MAJOR WEATHER CONCERNS TODAY AS A HIGH AMPLITUDE UPPER-LEVEL
RIDGE CONTINUES TO BUILD INTO THE AREA. LINGERING MOISTURE ALOFT
WILL AID IN AT LEAST ISOLATED COVERAGE OF SHOWERS AND TSTMS OVER
THE MOUNTAINS...BUT OTHERWISE SOUTHEAST WYOMING SHOULD REMAIN ON
THE DRY SIDE. THE ONLY CHANGE TO THE INHERITED GRIDS CONCERNS PCPN
CHANCES OVER THE PANHANDLE. WATER VAPOR SATELLITE SHOWS CONTINUED
NORTHWEST FLOW ALOFT ON THE EAST SIDE OF THE RIDGE...ATOP A WEAK
SFC MOISTURE BOUNDARY ANALYZED FROM NORTH TO SOUTH ACROSS THE HIGH
PLAINS. GOOD LLVL MOISTURE WITH DEW POINTS AROUND 60F SUGGESTS POTENTIAL
FOR ISOLATED CONVECTION. ADDED SLIGHT CHANCE POPS FOR THOSE ZONES
AS THIS SETUP IS VERY SIMILAR TO YESTERDAY. HRRR COMPOSITE RADAR
REFLECTIVITY ALSO HINTS AT THIS. WILL NEED TO WATCH FOR A STRONGER
STORM OR TWO AS THE LATEST SPC MESOANALYSIS INDICATES AROUND
1000-1500 J/KG CAPES AS OF 15Z. COVERAGE SHOULD BE MINIMAL. ALL
OTHER ASPECTS OF THE FCST ARE IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 415 AM MDT MON AUG 11 2014
A HIGH AMPLITUDE UPPER RIDGE WILL REMAIN OVER THE WESTERN CONUS TO
START THE WEEK...AND WILL SHIFT EAST TOWARD THE HIGH PLAINS BY
WEDNESDAY. CURRENT WATER VAPOR IMAGERY SHOWS A DRY DEFORMATION ZONE
OVER WYOMING WITH JUST A FEW MID/HIGH CLOUDS PASSING THRU OUR
NORTHERN ZONES ON THE WESTERN EDGE OF A STRONGER JET DIVING INTO THE
NORTHERN PLAINS AND UPPER MIDWEST. PERSISTENT SURFACE HIGH
PRESSURE OVER THE CENTRAL PLAINS WILL MAINTAIN EAST-SOUTHEASTERLY
UPSLOPE FLOW ACROSS THE HIGH PLAINS OF WYOMING AND WESTERN
NEBRASKA TODAY. SOME OF THE MID LEVEL MOISTURE ASSOCIATED WITH THE
UPPER JET WILL REMAIN OVER THE REGION...AND COMBINED WITH THE
UPSLOPE FLOW...COULD SEE A FEW T-STORMS DEVELOP OVER THE MOUNTAINS
OF SOUTHEAST WYOMING THIS AFTERNOON. ANY STORMS THAT DO DEVELOP
WILL REMAIN WEAK AND WILL LIKELY PRODUCE VERY LITTLE RAINFALL AS
LI`S WILL BE ROUGHLY MINUS 1 UNDER WEAK WINDS ALOFT.
THE UPPER RIDGE AXIS WILL SHIFT EAST OVER THE ROCKIES FOR TUESDAY
WITH SOME WEAK MID LEVEL ENERGY AND MOISTURE MOVING UP FROM THE
SOUTHWEST TOWARD THE CWA. CONVECTION LOOKS TO REMAIN CONFINED TO THE
MOUNTAINS AND NEARBY VALLEYS AS THIS AREA WILL BE CLOSER TO THE
MOISTURE AND ENERGY...ALTHOUGH COVERAGE LOOKS TO REMAIN QUITE
ISOLATED STILL. TEMPS WILL TREND UPWARD AS THE UPPER RIDGE AXIS
SHIFTS OVERHEAD...WITH 700MB TEMPS INCREASING TO BE 12 TO 16C BY
TUESDAY AFTERNOON.
A STRONGER SHORTWAVE WILL APPROACH THE CWA FROM THE SOUTHWEST ON
WEDNESDAY AFTERNOON AND WILL DRAG WITH IT A DEEPER FETCH OF
SUBTROPICAL MOISTURE. THE LEE SIDE PRESSURE TROUGH WILL DEEPEN IN
ADVANCE OF THIS WAVE...IN ADDITION TO A SECOND WAVE MOVING THRU
MONTANA. CONVERGENCE WITHIN THE SFC TROUGH WILL BRING A BETTER
CHANCE FOR SHOWERS AND STORMS TO THE EASTERN PLAINS OF WYOMING AND
NEBRASKA WEDNESDAY AFTERNOON...WHILE GENERAL OROGRAPHIC CONVECTION
LOOKS A GOOD BET WITH SUPPORT FROM THE SHORTWAVE FEATURE. PWATS
WILL INCREASE TO ROUGHLY ONE INCH OR HIGHER BY WEDNESDAY
AFTERNOON...SO THIS ACTIVITY COULD PRODUCE MODERATE TO LOCALLY HEAVY
RAIN AT TIMES THROUGH THE AFTERNOON. WINDS AT THE JET LEVEL WILL
INCREASE TO BE 30-40 KT...BUT WILL STILL BE WEAK AT 500 MB AND
BELOW SO TO POTENTIAL FOR STORMS TO BECOME ORGANIZED LOOKS TO BE
MINIMAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 415 AM MDT MON AUG 11 2014
STARTING OFF WEDNESDAY NIGHT...MONSOONAL MOISTURE STILL OVER THE
AREA WHICH WILL INTERACT WITH A SHORTWAVE MOVING THROUGH THE UPPER
LEVEL RIDGE. BOTH THE GFS AND ECMWF PRETTY SIMILAR WITH SHOWERS
OVER THE SOUTHERN CWFA. SOME DIFFERENCES BETWEEN THE TWO FOR
THURSDAY.
LATEST ECMWF SHOWS SOME ENERGY COMING OFF THE CLOSED LOW OVER THE
PACIFIC NW FURTHER WEST THAN THE GFS FOR THURSDAY AFTERNOON. AS A
RESULT...MORE WIDESPREAD SHOWERS AND QPF ARE OVER THE WESTERN HALF
OF THE CWFA COMPARED TO THE GFS SOLUTION. PWATS OVER RAWLINS
APPROACHING 1 INCH WITH FORECAST STORM MOTIONS UNDER 5KT. OVER
HERE BY CHEYENNE...FORECAST PWATS 1.2 INCHES AND BY SIDNEY...1.5
INCHES. SHOULD BE VERY EFFICIENT RAIN PRODUCERS FOR THURSDAY
AFTERNOON. CONTINUED CHANCE POPS FOR MOST OF THE CWFA WITH BEST
CHANCES IN THE MOUNTAINS.
BIGGER DIFFERENCES FOR FRIDAY. GFS HAS US DRY FOR FRIDAY AFTERNOON
WHILE THE ECMWF BRINGS ANOTHER PIECE OF ENERGY OFF THAT CLOSED LOW
INTO THE AREA. IF THE ECMWF COMES TRUE...WE WILL BE LOOKING AT
HEAVY RAINFALL ONCE AGAIN FRIDAY AFTERNOON AND EVENING. KEPT SOME
LOW CHANCE POPS IN THE FORECAST FOR THIS TIME FRAME.
CLOSED LOW FINALLY MOVES THROUGH NORTHERN MONTANA FOR SATURDAY AND
WE WILL SEE THE RETURN OF DRY WEATHER TO WYOMING. COULD START TO
GET BREEZY SATURDAY AS GFS 700MB WINDS HIT 20KT SATURDAY
AFTERNOON AND 25KT SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1120 AM MDT MON AUG 11 2014
A UPPER LEVEL RIDGE WILL LIMIT AFTERNOON CONVECTION TO THE HIGHER
TERRAIN OF SOUTHEAST WY. MOISTURE CONVERGENCE ALONG A NW-SE BOUNDARY
ACROSS NORTHWEST NE MAY TRIGGER ISOLATED TSTORMS BETWEEN 20Z AND
01Z IN AND AROUND CDR AND AIA. HAVE INSERTED VCTS AT THESE AERODROMES
FOR THIS POSSIBILITY. EXPECT SKIES TO BECOME CLEAR AFTER SUNSET.
WINDS WILL BE VARIABLE 10 KT OR LESS DURING THE NEXT 24 HRS.
&&
.FIRE WEATHER...
ISSUED AT 415 AM MDT MON AUG 11 2014
MOSTLY DRY CONDITIONS WILL PREVAIL THROUGH TUESDAY WITH ONLY A FEW
T-STORMS EXPECTED IN THE AFTERNOON FOR THE MOUNTAINS OF SOUTHEAST
WYOMING. THESE STORMS WILL BE WEAK AND SHOULD PRODUCE VERY LITTLE
RAINFALL. MINIMUM RELATIVE HUMIDITIES WILL DROP TO NEAR CRITICAL
VALUES OVER NORTHERN AND WESTERN PORTIONS OF CARBON COUNTY MONDAY
AND TUESDAY AFTERNOONS...HOWEVER WINDS IN THIS AREA WILL FOR THE
MOST PART AVERAGE 10 MPH OR LESS. THE EXCEPTION WILL BE IN THE
VICINITY OF SHOWERS AND THUNDERSTORMS WHERE WINDS WILL BE
VARIABLE AND GUSTY. INCREASING MONSOONAL MOISTURE AND STRONGER
UPPER LEVEL DISTURBANCES WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS WEDNESDAY AND THURSDAY. SHOWER COVERAGE DECREASES
LATE IN THE WEEK AS THE UPPER RIDGE BUILDS OVER THE DISTRICTS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...HAMMER
SHORT TERM...RJM
LONG TERM...CLAYCOMB
AVIATION...JAMSKI
FIRE WEATHER...RJM
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
940 AM MDT MON AUG 11 2014
.UPDATE...
ISSUED AT 935 AM MDT MON AUG 11 2014
NO MAJOR WEATHER CONCERNS TODAY AS A HIGH AMPLITUDE UPPER-LEVEL
RIDGE CONTINUES TO BUILD INTO THE AREA. LINGERING MOISTURE ALOFT
WILL AID IN AT LEAST ISOLATED COVERAGE OF SHOWERS AND TSTMS OVER
THE MOUNTAINS...BUT OTHERWISE SOUTHEAST WYOMING SHOULD REMAIN ON
THE DRY SIDE. THE ONLY CHANGE TO THE INHERITED GRIDS CONCERNS PCPN
CHANCES OVER THE PANHANDLE. WATER VAPOR SATELLITE SHOWS CONTINUED
NORTHWEST FLOW ALOFT ON THE EAST SIDE OF THE RIDGE...ATOP A WEAK
SFC MOISTURE BOUNDARY ANALYZED FROM NORTH TO SOUTH ACROSS THE HIGH
PLAINS. GOOD LLVL MOISTURE WITH DEWPOINTS AROUND 60F SUGGESTS PTNL
FOR ISOLATED CONVECTION. ADDED SLIGHT CHANCE POPS FOR THOSE ZONES
AS THIS SETUP IS VERY SIMILAR TO YESTERDAY. HRRR COMPOSITE RADAR
REFLECTIVITY ALSO HINTS AT THIS. WILL NEED TO WATCH FOR A STRONGER
STORM OR TWO AS THE LATEST SPC MESOANALYSIS INDICATES AROUND
1000-1500 J/KG CAPES AS OF 15Z. COVERAGE SHOULD BE MINIMAL. ALL
OTHER ASPECTS OF THE FCST ARE IN GOOD SHAPE.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 415 AM MDT MON AUG 11 2014
A HIGH AMPLITUDE UPPER RIDGE WILL REMAIN OVER THE WESTERN CONUS TO
START THE WEEK...AND WILL SHIFT EAST TOWARD THE HIGH PLAINS BY
WEDNESDAY. CURRENT WATER VAPOR IMAGERY SHOWS A DRY DEFORMATION ZONE
OVER WYOMING WITH JUST A FEW MID/HIGH CLOUDS PASSING THRU OUR
NORTHERN ZONES ON THE WESTERN EDGE OF A STRONGER JET DIVING INTO THE
NORTHERN PLAINS AND UPPER MIDWEST. PERSISTENT SURFACE HIGH
PRESSURE OVER THE CENTRAL PLAINS WILL MAINTAIN EAST-SOUTHEASTERLY
UPSLOPE FLOW ACROSS THE HIGH PLAINS OF WYOMING AND WESTERN
NEBRASKA TODAY. SOME OF THE MIDLEVEL MOISTURE ASSOCIATED WITH THE
UPPER JET WILL REMAIN OVER THE REGION...AND COMBINED WITH THE
UPSLOPE FLOW...COULD SEE A FEW T-STORMS DEVELOP OVER THE MOUNTAINS
OF SOUTHEAST WYOMING THIS AFTERNOON. ANY STORMS THAT DO DEVELOP
WILL REMAIN WEAK AND WILL LIKELY PRODUCE VERY LITTLE RAINFALL AS
LI`S WILL BE ROUGHLY MINUS 1 UNDER WEAK WINDS ALOFT.
THE UPPER RIDGE AXIS WILL SHIFT EAST OVER THE ROCKIES FOR TUESDAY
WITH SOME WEAK MIDLEVEL ENERGY AND MOISTURE MOVING UP FROM THE
SOUTHWEST TOWARD THE CWA. CONVECTION LOOKS TO REMAIN CONFINED TO THE
MOUNTAINS AND NEARBY VALLEYS AS THIS AREA WILL BE CLOSER TO THE
MOISTURE AND ENERGY...ALTHOUGH COVERAGE LOOKS TO REMAIN QUITE
ISOLATED STILL. TEMPS WILL TREND UPWARD AS THE UPPER RIDGE AXIS
SHIFTS OVERHEAD...WITH 700MB TEMPS INCREASING TO BE 12 TO 16C BY
TUESDAY AFTERNOON.
A STRONGER SHORTWAVE WILL APPROACH THE CWA FROM THE SOUTHWEST ON
WEDNESDAY AFTERNOON AND WILL DRAG WITH IT A DEEPER FETCH OF
SUBTROPICAL MOISTURE. THE LEESIDE PRESSURE TROUGH WILL DEEPEN IN
ADVANCE OF THIS WAVE...IN ADDITION TO A SECOND WAVE MOVING THRU
MONTANA. CONVERGENCE WITHIN THE SFC TROUGH WILL BRING A BETTER
CHANCE FOR SHOWERS AND STORMS TO THE EASTERN PLAINS OF WYOMING AND
NEBRASKA WEDNESDAY AFTERNOON...WHILE GENERAL OROGRAPHIC CONVECTION
LOOKS A GOOD BET WITH SUPPORT FROM THE SHORTWAVE FEATURE. PWATS
WILL INCREASE TO ROUGHLY ONE INCH OR HIGHER BY WEDNESDAY
AFTERNOON...SO THIS ACTIVITY COULD PRODUCE MODERATE TO LOCALLY HEAVY
RAIN AT TIMES THROUGH THE AFTERNOON. WINDS AT THE JET LEVEL WILL
INCREASE TO BE 30-40 KTS...BUT WILL STILL BE WEAK AT 500 MB AND
BELOW SO TO POTENTIAL FOR STORMS TO BECOME ORGANIZED LOOKS TO BE
MINIMAL.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 415 AM MDT MON AUG 11 2014
STARTING OFF WEDNESDAY NIGHT...MONSOONAL MOISTURE STILL OVER THE
AREA WHICH WILL INTERACT WITH A SHORTWAVE MOVING THROUGH THE UPPER
LEVEL RIDGE. BOTH THE GFS AND ECMWF PRETTY SIMILAR WITH SHOWERS
OVER THE SOUTHERN CWFA. SOME DIFFERENCES BETWEEN THE TWO FOR
THURSDAY.
LATEST ECMWF SHOWS SOME ENERGY COMING OFF THE CLOSED LOW OVER THE
PACNW FURTHER WEST THAN THE GFS FOR THURSDAY AFTERNOON. AS A
RESULT...MORE WIDESPREAD SHOWERS AND QPF ARE OVER THE WESTERN HALF
OF THE CWFA COMPARED TO THE GFS SOLUTION. PWATS OVER RAWLINS
APPROACHING 1 INCH WITH FORECAST STORM MOTIONS UNDER 5KTS. OVER
HERE BY CHEYENNE...FORECAST PWATS 1.2 INCHES AND BY SIDNEY...1.5
INCHES. SHOULD BE VERY EFFICIENT RAIN PRODUCERS FOR THURSDAY
AFTERNOON. CONTINUED CHANCE POPS FOR MOST OF THE CWFA WITH BEST
CHANCES IN THE MOUNTAINS.
BIGGER DIFFERENCES FOR FRIDAY. GFS HAS US DRY FOR FRIDAY AFTERNOON
WHILE THE ECMWF BRINGS ANOTHER PIECE OF ENERGY OFF THAT CLOSED LOW
INTO THE AREA. IF THE ECMWF COMES TRUE...WE WILL BE LOOKING AT
HEAVY RAINFALL ONCE AGAIN FRIDAY AFTERNOON AND EVENING. KEPT SOME
LOW CHANCE POPS IN THE FORECAST FOR THIS TIME FRAME.
CLOSED LOW FINALLY MOVES THROUGH NORTHERN MONTANA FOR SATURDAY AND
WE WILL SEE THE RETURN OF DRY WEATHER TO WYOMING. COULD START TO
GET BREEZY SATURDAY AS GFS 700MB WINDS HIT 20KTS SATURDAY
AFTERNOON AND 25KTS SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 428 AM MDT MON AUG 11 2014
VFR CONDITIONS EXPECTED AT ALL SOUTHEAST WYOMING AND NEBRASKA
PANHANDLE AIRPORTS TODAY AS HIGH PRESSURE REMAINS OVER COLORADO.
COULD SEE ISOLATED TO WIDELY SCATTERED AFTERN AND EARLY EVENING
THUNDERSTORMS OVER THE MOUNTAINS TODAY...BUT THAT CHANCE IS SMALL.
&&
.FIRE WEATHER...
ISSUED AT 415 AM MDT MON AUG 11 2014
MOSTLY DRY CONDITIONS WILL PREVAIL THROUGH TUESDAY WITH ONLY A FEW
T-STORMS EXPECTED IN THE AFTERNOON FOR THE MOUNTAINS OF SOUTHEAST
WYOMING. THESE STORMS WILL BE WEAK AND SHOULD PRODUCE VERY LITTLE
RAINFALL. MINIMUM RELATIVE HUMIDITIES WILL DROP TO NEAR CRITICAL
VALUES OVER NORTHERN AND WESTERN PORTIONS OF CARBON COUNTY MONDAY
AND TUESDAY AFTERNOONS...HOWEVER WINDS IN THIS AREA WILL FOR THE
MOST PART AVERAGE 10 MPH OR LESS. THE EXCEPTION WILL BE IN THE
VICINITY OF SHOWERS AND THUNDERSTORMS WHERE WINDS WILL BE
VARIABLE AND GUSTY. INCREASING MONSOONAL MOISTURE AND STRONGER
UPPER LEVEL DISTURBANCES WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS WEDNESDAY AND THURSDAY. SHOWER COVERAGE DECREASES
LATE IN THE WEEK AS THE UPPER RIDGE BUILDS OVER THE DISTRICTS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...HAMMER
SHORT TERM...RJM
LONG TERM...CLAYCOMB
AVIATION...CLAYCOMB
FIRE WEATHER...RJM
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
351 AM MDT WED AUG 13 2014
CORRECTED FOR FORMATTING ERRORS
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
EVERYTHING COMING TOGETHER AS EXPECTED WITH MONSOONAL MOISTURE
CONTINUING TO STREAM INTO THE AREA. OBSERVED PWATS IN GRAND
JUNCTION YESTERDAY EVENING REACHED 1.04 INCHES SO PLENTY OF
MOISTURE FOR ANY DISTURBANCES TO WORK WITH. EVEN AT THIS EARLY
HOUR...RADAR IS PICKING UP ON SOME LIGHT RETURNS WHICH NAM AND
HRRR ARE ALSO HIGHLIGHTING. HRRR ALSO SHOWING SOME CONVECTION
FIRING IN A FEW HOURS OVER DURANGO MUCH LIKE YESTERDAY MORNING SO
WILL BE INTERESTING TO SEE IF THIS PANS OUT.
ALL MODELS CONTINUE TO SHOW PLENTY OF PRECIP FOR OUR AREA TODAY
AS UPPER LEVEL SUPPORT IS MINIMAL AT BEST. ONE FLY IN THE OINTMENT
THOUGH IS A VERY WEAK JET STREAK THAT`S FORECAST TO MOVE OVER THE
UT/CO BORDER TODAY PRODUCING SOME FAIRLY NOTICEABLE DIVERGENCE
ALOFT. THE JET STREAK IS REALLY QUITE UNIMPRESSIVE...HOWEVER...A
SIMILAR JET STREAK MOVED OVERHEAD LAST WEEK BRINGING PLENTY OF
FLASH FLOODING AND STORMS TO THE REGION FOR THOSE THAT REMEMBER.
ON THE FLIP SIDE OF THAT...CLOUD COVER MAY INHIBIT STRONGER
CONVECTION TODAY DESPITE ANY UPPER LEVEL SUPPORT. LOOKING
UPSTREAM...SALT LAKE CITY HAD A GANGBUSTERS DAY YESTERDAY WITH
HEAVY RAIN AND STRONG WINDS BEING COMMON. GOING TO FOLLOW THAT LEAD
AND EXPECT THUNDERSTORMS AND SHOWERS TODAY WITH HEAVY
RAIN...STRONG WINDS EXCEEDING 45 MPH...AND HAIL. OBVIOUSLY...THE
FLASH FLOOD WATCH REMAINS IN PLACE. SPEAKING OF...EXTENDED THE WATCH
THROUGH EARLY FRIDAY MORNING AS BOTH THE GFS AND NAM CONTINUE TO
FORM A STRONG SHORTWAVE THAT WILL MOVE OVERHEAD WEDNESDAY NIGHT
INTO THURSDAY. SOME DIFFERENCES IN TIMING AND STRENGTH REMAIN BUT
THINK IT BETTER TO GET WORD OUT NOW.
PLUME OF HEAVY RAIN AND EMBEDDED THUNDERSTORMS ASSOCIATED WITH
THE ELONGATED H5 VORT MAX WILL CONTINUE TO TRACK EAST THROUGH
WESTERN COLORADO TONIGHT AND THURSDAY MORNING. 0-6 KM BULK SHEAR
OF 20-35 KTS IS STILL FORECAST SUGGESTING ORGANIZED MULTICELLS
WITH FLASH FLOODING STILL BEING THE MOST LIKELY IMPACT. STRONG
DOWNDRAFTS AND HAIL ALSO REMAIN POSSIBLE WITH THESE STORMS. THE WEAK
40KT JET ALOFT IS ALSO EXPECTED TO CONTINUE TO PROVIDE SUPPORT FOR
STORM TOP DIVERGENCE THROUGHOUT THE NIGHT. PRECIPITABLE WATER
VALUES WILL TOP OUT AROUND 1.25 INCHES TONIGHT BEFORE DRYING OUT
SLIGHTLY THURSDAY AFTERNOON BEHIND THE DISTURBANCE IN WESTERLY
FLOW. EXPECT A WET THURSDAY MORNING ACROSS MUCH OF WESTERN
COLORADO AS THE BULK OF THE MOISTURE CONTINUES TO TREK EAST. WEAK
RIDGING WILL MOVE INTO THE REGION BEHIND THE DISTURBANCE
PASSAGE...BUT CAPE VALUES THURSDAY AFTERNOON IN EASTERN UTAH
SUGGEST A BATCH OF CONVECTION INITIATING BEHIND THE MAIN AREA OF
RAIN AS SKIES CLEAR THROUGHOUT THE DAY. SEEMS PLAUSIBLE DUE TO
STEEP LAPSE RATES AND PLENTY OF MOISTURE STILL ACCESSIBLE FOR
QUICKLY DEVELOPING THUNDERSTORMS WITH THE BIGGEST THREAT STILL
BEING HEAVY RAIN.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
THURSDAY NIGHT SHOULD BE PRETTY QUIET AS HIGH PRESSURE RETURNS
OVER THE REGION. MOISTURE STUCK UNDER THE RIDGE WILL HELP TO
INITIATE OROGRAPHIC SHOWERS AND THUNDERSTORMS AGAIN ON FRIDAY
AFTERNOON BUT OF AN ISOLATED NATURE.
CONVECTION WILL DIE DOWN QUICKLY NEAR SUNSET FRIDAY EVENING AS
ZONAL FLOW SETS UP OVER THE AREA. HIGH PRESSURE ALSO GETS SET TO
REBUILD INTO THE DESERT SW. AS ANTICYCLONIC FLOW SETS UP OVER THE
CWA...NO MOISTURE IS EXPECTED TO INTRUDE INTO THE AREA ALLOWING
GARDEN VARIETY STORMS TO FIRE EACH AFTN/EVENING. THIS CONTINUES
THROUGH TUESDAY AS MOST AREAS WILL SEE SOME CU BUILD UP EACH AFTN
OVER HIGHER TERRAIN. VALLEYS SHOULD STAY DRY WITH NORMAL
TEMPERATURES EXPECTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 334 AM MDT WED AUG 13 2014
THUNDERSTORMS AND RAINSHOWERS WILL INCREASE TODAY FROM THE SOUTH
AND WEST. HEAVY RAIN...GUSTY OUTFLOW WINDS EXCEEDING 40 MPH AT
TIMES...AND HAIL ARE POSSIBLE THIS AFTERNOON. MVFR TO IFR CIGS/VIS
WILL OCCUR UNDER THE STRONGEST CELLS THAT FORM. ALL AERODROMES
UNDER THE GUN TODAY AND THIS IS REFLECTED IN TAFS WITH MEDIUM TO
HIGH CONFIDENCE FOR SHOWERS AND STORMS. THESE CONDITIONS WILL
CONTINUE FOR THE NEXT 24 HOURS THOUGH INTENSITY SHOULD DECREASE
SOMEWHAT AFTER 03Z.
&&
.HYDROLOGY...
ISSUED AT 334 AM MDT WED AUG 13 2014
FLASH FLOOD WATCH REMAINS IN EFFECT AND HAS BEEN EXTENDED THROUGH
06Z FRIDAY AS DEEP SUBTROPICAL MOISTURE ASSOCIATED WITH THE MONSOONAL
SURGE SLIDES OVER THE AREA. STORMS WILL HAVE SOME MOTION
TODAY BUT EVEN SO...DYNAMIC INPUT AND AMPLE MOISTURE WILL CAUSE
HEAVY RAIN FROM THUNDERSTORMS. RAINFALL OF 1 INCH OR MORE WILL BE
POSSIBLE. LOW LYING AREAS NEAR STEEP TERRAIN AND WILDFIRE BURN
SCARS...SLOT CANYONS AND SLICK ROCK AREAS...NORMALLY DRY
CREEKS...STREAMS AND ARROYOS HAVE THE HIGHEST THREAT OF FLASH
FLOODING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THURSDAY EVENING
FOR COZ001>014-017>019-022-023.
FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR COZ020-021.
UT...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THURSDAY EVENING
FOR UTZ023>025-027.
FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR UTZ022-028-029.
&&
$$
SHORT TERM...TGR/JAM
LONG TERM...JAM/TGR
AVIATION...TGR
HYDROLOGY...TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
349 AM MDT WED AUG 13 2014
CORRECTED FOR FORMATTING ERROR
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
EVERYTHING COMING TOGETHER AS EXPECTED WITH MONSOONAL MOISTURE
CONTINUING TO STREAM INTO THE AREA. OBSERVED PWATS IN GRAND
JUNCTION YESTERDAY EVENING REACHED 1.04 INCHES SO PLENTY OF
MOISTURE FOR ANY DISTURBANCES TO WORK WITH. EVEN AT THIS EARLY
HOUR...RADAR IS PICKING UP ON SOME LIGHT RETURNS WHICH NAM AND
HRRR ARE ALSO HIGHLIGHTING. HRRR ALSO SHOWING SOME CONVECTION
FIRING IN A FEW HOURS OVER DURANGO MUCH LIKE YESTERDAY MORNING SO
WILL BE INTERESTING TO SEE IF THIS PANS OUT.
ALL MODELS CONTINUE TO SHOW PLENTY OF PRECIP FOR OUR AREA TODAY
AS UPPER LEVEL SUPPORT IS MINIMAL AT BEST. ONE FLY IN THE OINTMENT
THOUGH IS A VERY WEAK JET STREAK THAT`S FORECAST TO MOVE OVER THE
UT/CO BORDER TODAY PRODUCING SOME FAIRLY NOTICEABLE DIVERGENCE
ALOFT. THE JET STREAK IS REALLY QUITE UNIMPRESSIVE...HOWEVER...A
SIMILAR JET STREAK MOVED OVERHEAD LAST WEEK BRINGING PLENTY OF
FLASH FLOODING AND STORMS TO THE REGION FOR THOSE THAT REMEMBER.
ON THE FLIP SIDE OF THAT...CLOUD COVER MAY INHIBIT STRONGER
CONVECTION TODAY DESPITE ANY UPPER LEVEL SUPPORT. LOOKING
UPSTREAM...SALT LAKE CITY HAD A GANGBUSTERS DAY YESTERDAY WITH
HEAVY RAIN AND STRONG WINDS BEING COMMON. GOING TO FOLLOW THAT LEAD
AND EXPECT THUNDERSTORMS AND SHOWERS TODAY WITH HEAVY
RAIN...STRONG WINDS EXCEEDING 45 MPH...AND HAIL. OBVIOUSLY...THE
FLASH FLOOD WATCH REMAINS IN PLACE. SPEAKING OF...EXTENDED THE WATCH
THROUGH EARLY FRIDAY MORNING AS BOTH THE GFS AND NAM CONTINUE TO
FORM A STRONG SHORTWAVE THAT WILL MOVE OVERHEAD WEDNESDAY NIGHT
INTO THURSDAY. SOME DIFFERENCES IN TIMING AND STRENGTH REMAIN BUT
THINK IT BETTER TO GET WORD OUT NOW.
PLUME OF HEAVY RAIN AND EMBEDDED THUNDERSTORMS ASSOCIATED WITH
THE ELONGATED H5 VORT MAX WILL CONTINUE TO TRACK EAST THROUGH
WESTERN COLORADO TONIGHT AND THURSDAY MORNING. 0-6 KM BULK SHEAR
OF 20-35 KTS IS STILL FORECAST SUGGESTING ORGANIZED MULTICELLS
WITH FLASH FLOODING STILL BEING THE MOST LIKELY IMPACT. STRONG
DOWNDRAFTS AND HAIL ALSO REMAIN POSSIBLE WITH THESE STORMS. THE WEAK
40KT JET ALOFT IS ALSO EXPECTED TO CONTINUE TO PROVIDE SUPPORT FOR
STORM TOP DIVERGENCE THROUGHOUT THE NIGHT. PRECIPITABLE WATER
VALUES WILL TOP OUT AROUND 1.25 INCHES TONIGHT BEFORE DRYING OUT
SLIGHTLY THURSDAY AFTERNOON BEHIND THE DISTURBANCE IN WESTERLY
FLOW. EXPECT A WET THURSDAY MORNING ACROSS MUCH OF WESTERN
COLORADO AS THE BULK OF THE MOISTURE CONTINUES TO TREK EAST. WEAK
RIDGING WILL MOVE INTO THE REGION BEHIND THE DISTURBANCE
PASSAGE...BUT CAPE VALUES THURSDAY AFTERNOON IN EASTERN UTAH
SUGGEST A BATCH OF CONVECTION INITIATING BEHIND THE MAIN AREA OF
RAIN AS SKIES CLEAR THROUGHOUT THE DAY. SEEMS PLAUSIBLE DUE TO
STEEP LAPSE RATES AND PLENTY OF MOISTURE STILL ACCESSIBLE FOR
QUICKLY DEVELOPING THUNDERSTORMS WITH THE BIGGEST THREAT STILL
BEING HEAVY RAIN.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
THURSDAY NIGHT SHOULD BE PRETTY QUIET AS HIGH PRESSURE RETURNS
OVER THE REGION. MOISTURE STUCK UNDER THE RIDGE WILL HELP TO
INITIATE OROGRAPHIC SHOWERS AND THUNDERSTORMS AGAIN ON FRIDAY
AFTERNOON BUT OF AN ISOLATED NATURE.
CONVECTION WILL DIE DOWN QUICKLY NEAR SUNSET FRIDAY EVENING AS
ZONAL FLOW SETS UP OVER THE AREA. HIGH PRESSURE ALSO GETS SET TO
REBUILD INTO THE DESERT SW. AS ANTICYCLONIC FLOW SETS UP OVER THE
CWA...NO MOISTURE IS EXPECTED TO INTRUDE INTO THE AREA ALLOWING
GARDEN VARIETY STORMS TO FIRE EACH AFTN/EVENING. THIS CONTINUES
THROUGH TUESDAY AS MOST AREAS WILL SEE SOME CU BUILD UP EACH AFTN
OVER HIGHER TERRAIN. VALLEYS SHOULD STAY DRY WITH NORMAL
TEMPERATURES EXPECTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 334 AM MDT WED AUG 13 2014
THUNDERSTORMS AND RAINSHOWERS WILL INCREASE TODAY FROM THE SOUTH
AND WEST. HEAVY RAIN...GUSTY OUTFLOW WINDS EXCEEDING 40 MPH AT
TIMES...AND HAIL ARE POSSIBLE THIS AFTERNOON. MVFR TO IFR CIGS/VIS
WILL OCCUR UNDER THE STRONGEST CELLS THAT FORM. ALL AERODROMES
UNDER THE GUN TODAY AND THIS IS REFLECTED IN TAFS WITH MEDIUM TO
HIGH CONFIDENCE FOR SHOWERS AND STORMS. THESE CONDITIONS WILL
CONTINUE FOR THE NEXT 24 HOURS THOUGH INTENSITY SHOULD DECREASE
SOMEWHAT AFTER 03Z.
&&
.HYDROLOGY...
ISSUED AT 334 AM MDT WED AUG 13 2014
FLASH FLOOD WATCH REMAINS IN EFFECT AND HAS BEEN EXTENDED THROUGH
06Z FRIDAY AS DEEP SUBTROPICAL MOISTURE ASSOCIATED WITH THE MONSOONAL
SURGE SLIDES OVER THE AREA. STORMS WILL HAVE SOME MOTION
TODAY BUT EVEN SO...DYNAMIC INPUT AND AMPLE MOISTURE WILL CAUSE
HEAVY RAIN FROM THUNDERSTORMS. RAINFALL OF 1 INCH OR MORE WILL BE
POSSIBLE. LOW LYING AREAS NEAR STEEP TERRAIN AND WILDFIRE BURN
SCARS...SLOT CANYONS AND SLICK ROCK AREAS...NORMALLY DRY
CREEKS...STREAMS AND ARROYOS HAVE THE HIGHEST THREAT OF FLASH
FLOODING.
&&
.HYDROLOGY...
ISSUED AT 334 AM MDT WED AUG 13 2014
FLASH FLOOD WATCH REMAINS IN EFFECT AND HAS BEEN EXTENDED THROUGH
06Z FRIDAY AS DEEP SUBTROPICAL MOISTURE ASSOCIATED WITH THE MONSOONAL
SURGE SLIDES OVER THE AREA. STORMS WILL HAVE SOME MOTION
TODAY BUT EVEN SO...DYNAMIC INPUT AND AMPLE MOISTURE WILL CAUSE
HEAVY RAIN FROM THUNDERSTORMS. RAINFALL OF 1 INCH OR MORE WILL BE
POSSIBLE. LOW LYING AREAS NEAR STEEP TERRAIN AND WILDFIRE BURN
SCARS...SLOT CANYONS AND SLICK ROCK AREAS...NORMALLY DRY
CREEKS...STREAMS AND ARROYOS HAVE THE HIGHEST THREAT OF FLASH
FLOODING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THURSDAY EVENING
FOR COZ001>014-017>019-022-023.
FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR COZ020-021.
UT...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THURSDAY EVENING
FOR UTZ023>025-027.
FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR UTZ022-028-029.
&&
$$
SHORT TERM...TGR/JAM
LONG TERM...JAM/TGR
AVIATION...TGR
HYDROLOGY...TGJT
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
334 AM MDT WED AUG 13 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
EVERYTHING COMING TOGETHER AS EXPECTED WITH MONSOONAL MOISTURE
CONTINUING TO STREAM INTO THE AREA. OBSERVED PWATS IN GRAND
JUNCTION YESTERDAY EVENING REACHED 1.04 INCHES SO PLENTY OF
MOISTURE FOR ANY DISTURBANCES TO WORK WITH. EVEN AT THIS EARLY
HOUR...RADAR IS PICKING UP ON SOME LIGHT RETURNS WHICH NAM AND
HRRR ARE ALSO HIGHLIGHTING. HRRR ALSO SHOWING SOME CONVECTION
FIRING IN A FEW HOURS OVER DURANGO MUCH LIKE YESTERDAY MORNING SO
WILL BE INTERESTING TO SEE IF THIS PANS OUT.
ALL MODELS CONTINUE TO SHOW PLENTY OF PRECIP FOR OUR AREA TODAY
AS UPPER LEVEL SUPPORT IS MINIMAL AT BEST. ONE FLY IN THE OINTMENT
THOUGH IS A VERY WEAK JET STREAK THAT`S FORECAST TO MOVE OVER THE
UT/CO BORDER TODAY PRODUCING SOME FAIRLY NOTICEABLE DIVERGENCE
ALOFT. THE JET STREAK IS REALLY QUITE UNIMPRESSIVE...HOWEVER...A
SIMILAR JET STREAK MOVED OVERHEAD LAST WEEK BRINGING PLENTY OF
FLASH FLOODING AND STORMS TO THE REGION FOR THOSE THAT REMEMBER.
ON THE FLIP SIDE OF THAT...CLOUD COVER MAY INHIBIT STRONGER
CONVECTION TODAY DESPITE ANY UPPER LEVEL SUPPORT. LOOKING
UPSTREAM...SALT LAKE CITY HAD A GANGBUSTERS DAY YESTERDAY WITH
HEAVY RAIN AND STRONG WINDS BEING COMMON. GOING TO FOLLOW THAT LEAD
AND EXPECT THUNDERSTORMS AND SHOWERS TODAY WITH HEAVY
RAIN...STRONG WINDS EXCEEDING 45 MPH...AND HAIL. OBVIOUSLY...THE
FLASH FLOOD WATCH REMAINS IN PLACE. SPEAKING OF...EXTENDED THE WATCH
THROUGH EARLY FRIDAY MORNING AS BOTH THE GFS AND NAM CONTINUE TO
FORM A STRONG SHORTWAVE THAT WILL MOVE OVERHEAD WEDNESDAY NIGHT
INTO THURSDAY. SOME DIFFERENCES IN TIMING AND STRENGTH REMAIN BUT
THINK IT BETTER TO GET WORD OUT NOW.
PLUME OF HEAVY RAIN AND EMBEDDED THUNDERSTORMS ASSOCIATED WITH
THE ELONGATED H5 VORT MAX WILL CONTINUE TO TRACK EAST THROUGH
WESTERN COLORADO TONIGHT AND THURSDAY MORNING. 0-6 KM BULK SHEAR
OF 20-35 KTS IS STILL FORECAST SUGGESTING ORGANIZED MULTICELLS
WITH FLASH FLOODING STILL BEING THE MOST LIKELY IMPACT. STRONG
DOWNDRAFTS AND HAIL ALSO REMAIN POSSIBLE WITH THESE STORMS. THE WEAK
40KT JET ALOFT IS ALSO EXPECTED TO CONTINUE TO PROVIDE SUPPORT FOR
STORM TOP DIVERGENCE THROUGHOUT THE NIGHT. PRECIPITABLE WATER
VALUES WILL TOP OUT AROUND 1.25 INCHES TONIGHT BEFORE DRYING OUT
SLIGHTLY THURSDAY AFTERNOON BEHIND THE DISTURBANCE IN WESTERLY
FLOW. EXPECT A WET THURSDAY MORNING ACROSS MUCH OF WESTERN
COLORADO AS THE BULK OF THE MOISTURE CONTINUES TO TREK EAST. WEAK
RIDGING WILL MOVE INTO THE REGION BEHIND THE DISTURBANCE
PASSAGE...BUT CAPE VALUES THURSDAY AFTERNOON IN EASTERN UTAH
SUGGEST A BATCH OF CONVECTION INITIATING BEHIND THE MAIN AREA OF
RAIN AS SKIES CLEAR THROUGHOUT THE DAY. SEEMS PLAUSIBLE DUE TO
STEEP LAPSE RATES AND PLENTY OF MOISTURE STILL ACCESSIBLE FOR
QUICKLY DEVELOPING THUNDERSTORMS WITH THE BIGGEST THREAT STILL
BEING HEAVY RAIN.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
THURSDAY NIGHT SHOULD BE PRETTY QUIET AS HIGH PRESSURE RETURNS
OVER THE REGION. MOISTURE STUCK UNDER THE RIDGE WILL HELP TO
INITIATE OROGRAPHIC SHOWERS AND THUNDERSTORMS AGAIN ON FRIDAY
AFTERNOON BUT OF AN ISOLATED NATURE.
CONVECTION WILL DIE DOWN QUICKLY NEAR SUNSET FRIDAY EVENING AS
ZONAL FLOW SETS UP OVER THE AREA. HIGH PRESSURE ALSO GETS SET TO
REBUILD INTO THE DESERT SW. AS ANTICYCLONIC FLOW SETS UP OVER THE
CWA...NO MOISTURE IS EXPECTED TO INTRUDE INTO THE AREA ALLOWING
GARDEN VARIETY STORMS TO FIRE EACH AFTN/EVENING. THIS CONTINUES
THROUGH TUESDAY AS MOST AREAS WILL SEE SOME CU BUILD UP EACH AFTN
OVER HIGHER TERRAIN. VALLEYS SHOULD STAY DRY WITH NORMAL
TEMPERATURES EXPECTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 334 AM MDT WED AUG 13 2014
THUNDERSTORMS AND RAINSHOWERS WILL INCREASE TODAY FROM THE SOUTH
AND WEST. HEAVY RAIN...GUSTY OUTFLOW WINDS EXCEEDING 40 MPH AT
TIMES...AND HAIL ARE POSSIBLE THIS AFTERNOON. MVFR TO IFR CIGS/VIS
WILL OCCUR UNDER THE STRONGEST CELLS THAT FORM. ALL AERODROMES
UNDER THE GUN TODAY AND THIS IS REFLECTED IN TAFS WITH MEDIUM TO
HIGH CONFIDENCE FOR SHOWERS AND STORMS. THESE CONDITIONS WILL
CONTINUE FOR THE NEXT 24 HOURS THOUGH INTENSITY SHOULD DECREASE
SOMEWHAT AFTER 03Z.
.HYDROLOGY...
ISSUED AT 334 AM MDT WED AUG 13 2014
FLASH FLOOD WATCH REMAINS IN EFFECT AND HAS BEEN EXTENDED THROUGH
06Z FRIDAY AS DEEP SUBTROPICAL MOISTURE ASSOCIATED WITH THE MONSOONAL
SURGE SLIDES OVER THE AREA. STORMS WILL HAVE SOME MOTION
TODAY BUT EVEN SO...DYNAMIC INPUT AND AMPLE MOISTURE WILL CAUSE
HEAVY RAIN FROM THUNDERSTORMS. RAINFALL OF 1 INCH OR MORE WILL BE
POSSIBLE. LOW LYING AREAS NEAR STEEP TERRAIN AND WILDFIRE BURN
SCARS...SLOT CANYONS AND SLICK ROCK AREAS...NORMALLY DRY
CREEKS...STREAMS AND ARROYOS HAVE THE HIGHEST THREAT OF FLASH
FLOODING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THURSDAY EVENING
FOR COZ001>014-017>019-022-023.
FLASH FLOOD WATCH FROM 6 AM MDT THIS MORNING THROUGH THURSDAY
EVENING FOR COZ020-021.
UT...FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THURSDAY EVENING
FOR UTZ023>025-027.
FLASH FLOOD WATCH FROM 6 AM MDT THIS MORNING THROUGH THURSDAY
EVENING FOR UTZ022-028-029.
&&
$$
SHORT TERM...TGR/JAM
LONG TERM...JAM/TGR
AVIATION...TGR
HYDROLOGY...TGJT
AREA FORECAST DISCUSSION
NWS TAUNTON MA
310 AM EDT WED AUG 13 2014
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL BRING HEAVY RAIN ON WEDNESDAY.
AREAS OF URBAN AND LOCALIZED FLASH FLOODING ARE THE MAIN THREATS
WITH A LOW PROBABILITY FOR ISOLATED SEVERE WEATHER. ISOLATED SHOWERS
MAY DEVELOP ACROSS INLAND AREAS DURING THE DAYLIGHT HOURS LATE
THIS WEEK. EXPECT GENERALLY DRY CONDITIONS INTO EARLY THIS
WEEKEND...THEN ANOTHER SHOT FOR SHOWERS MOVES THROUGH THE REGION
SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
130 AM UPDATE...
LATEST MESOSCALE GUIDANCE INCLUDING THE HRRR AND RAP13 STRUGGLING
TO SIMULATE HEAVY RAIN ACROSS COASTAL NJ/NYC AND LONG ISLAND. 00Z
GFS APPEARS TO BE HANDLING THE ACTIVITY BEST. THE GFS PROPROGATES
THIS AREA OF HEAVY RAIN NORTHEAST INTO CT/RI AND SOUTH OF THE MASS
PIKE BY 12Z. THIS SEEMS REASONABLE AS LOW LEVEL JET BEGINS TO
INTENSIFY DURING THIS TIME SOUTH OF NEW ENGLAND. ONE AREA OF
CONCERN IS THE LACK OF RAIN/SHOWERS DOWNSTREAM OF THIS ACTIVITY
ACROSS PA INTO NY STATE. CONVECTION ACROSS COASTAL NJ/NYC AND LONG
ISLAND MAY BE PRECLUDING INSTABILITY AND MOISTURE FROM BEING
ADVECTED NORTHWARD. WILL HAVE TO WATCH HOW THIS EVOLVES AND SEE
HOW 00Z ECMWF AND OTHER GUID SIMULATE THIS CONVECTION. OTHERWISE
NO WHOLESALE CHANGES TO PREVIOUS FORECAST. EARLIER DISCUSSION
BELOW.
================================================================
TORRENTIAL RAINFALL/FLASH FLOODING BEGINNING TO COMMENCE OVER NJ
AS LOW LEVEL JET BEGINS TO FORM AND IS ALSO COLOCATED WITH AREA
OF BEST PRES FALLS AND ALONG WARM FRONTAL BOUNDARY. THIS HAS
INITIATED EMBEDDED CONVECTION WITHIN THIS AREA. MILLVILLE NJ IN
THE SOUTHERN PART OF THE STATE RECEIVED 3.39 INCHES OF RAINFALL
FROM 7 PM TO 9 PM! NONE OF THE HI RES MODEL GUID HANDLING THIS
PARTICULARLY WELL INCLUDING THE HRRR AND RAP13. THE GLOBAL GUID
/GFS AND ECMWF/ IS BETTER BUT IS TOO SLOW IN SPINNING UP
CONVECTION. THIS AREA OF EXCESSIVE RAINFALL IS TRACKING NNE TOWARD
NYC AND SHOULD ARRIVE INTO WESTERN NEW ENGLAND INCLUDING THE
GREATER HARTFORD/SPRINGFIELD AREA AROUND OR AFTER SUNRISE.
FARTHER EASTWARD MESO ANALYSIS CONTINUES TO INDICATE DEEP LAYER OF
DRY AIR ESPECIALLY AROUND 850 MB SOUTH OF NEW ENGLAND THAT STILL
HAS TO BE ADVECTED NORTHWARD. THIS IS ALSO EVIDENT ON THE 00Z OKX
UPPER AIR SOUNDING. THUS STEADY RAINS WILL NOT ARRIVE ACROSS MUCH
OF THE REGION UNTIL AFTER 12Z. HENCE HEAVIEST RAINFALL FOR MUCH OF
THE REGION ARRIVES LATE MORNING INTO EARLY AFTERNOON WED...
POSSIBLY LINGERING AND IMPACTING THE LATE DAY COMMUTE FOR THE
GREATER BOSTON AREA. PREVIOUS FORECAST CAPTURES THESE DETAILS
NICELY SO NO MAJOR CHANGES EXPECTED WITH THIS UPDATE. EARLIER
DISCUSSION BELOW.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
***FLASH FLOOD WATCH FOR THE POTENTIAL OF URBAN AND LOCALIZED FLASH
FLOODING IS THE MAIN CONCERN WEDNESDAY***
1) HEAVY RAIN - FLASH FLOOD THREAT
A LOW LEVEL JET 4 TO 5 STANDARD DEVIATIONS ABOVE NORMAL WILL
COMBINED WITH PWATS BETWEEN 1.75 AND 2 INCHES. THAT IS A CLASSIC
SETUP FOR A SUMMER TIME HEAVY RAIN AND LOCALIZED FLASH FLOOD EVENT.
THE MAIN UNCERTAINTY IS TRYING TO LOCATE WHERE THE HEAVIEST
RAIN/FLOOD THREAT WILL SET UP. GIVEN THAT WE HAVE SOUTH TO
SOUTHEAST FLOW...EXPECT TO SEE THE NORMALLY FAVORED UPSLOPE REGIONS
ALONG THE EAST SLOPES OF THE BERKSHIRES/WORCESTER HILLS AND
MONADNOCKS PERHAPS SEE LOCALLY HIGHER AMOUNTS. THERE MAY ALSO BE A
SECONDARY AREAS ACROSS EASTERN MA/RHODE ISLAND GIVEN A BETTER CHANCE
FOR EMBEDDED THUNDERSTORMS WITH HIGHER INSTABILITY.
OVERALL...EXPECT 1 TO 3 INCHES OF RAINFALL ACROSS MOST AREAS...WITH
LOCALIZED 4 OR 5 INCH AMOUNTS NOT OUT OF THE QUESTION. FORECASTING
QPF AMOUNTS IN THE SUMMER IS NO EASY TASK GIVEN CONVECTIVE FEEDBACK
ISSUES ETC. WE ARE NOT GOING TO BE ABLE TO PINPOINT EXACTLY WHERE
THE BEST CHANCE OF FLASH FLOODING MAY SETUP...OTHER THAN A GENERAL
OVERVIEW GIVEN IN THE PREVIOUS PARAGRAPH. THE MORE IMPORTANT THEME
IS THE POTENTIAL FOR SOME LOCALES TO RECEIVE 2+ INCHES OF RAIN IN
LESS THAN 1 HOUR...LEADING TO THE POTENTIAL FOR SOME URBAN AND
LOCALIZED FLASH FLOODING. THAT IS THE REASON A FLASH FLOOD WATCH IS
IN EFFECT FOR ALL BUT THE CAPE/ISLANDS ON WEDNESDAY.
2) SEVERE WEATHER THREAT
THE BEST SHEAR AND INSTABILITY DO NOT OVERLAP ON WEDNESDAY...SO
SEVERE WEATHER POTENTIAL APPEARS LIMITED. IN ADDITION...RAIN AND
CLOUD COVER WILL LIMIT THE AMOUNT OF INSTABILITY THAT IS ABLE TO
DEVELOP. HOWEVER...THERE IS STILL A LOW PROBABILITY FOR A FEW
STRONG TO SEVERE THUNDERSTORMS ACROSS NORTHERN CT/RHODE ISLAND AND
EASTERN MA. THIS WILL BE DEPENDENT ON WHETHER OR NOT WE CAN MUSTER
ENOUGH INSTABILITY AND HOW FAR NORTH THE SURFACE WARM FRONT MAKES IT
ACROSS THE REGION. ISOLATED STRONG WIND GUSTS WOULD BE THE MAIN
CONCERN. HOWEVER...GIVEN WE WILL HAVE A WARM FRONT TRYING TO LIFT
NORTH THERE IS A LOW PROBABILITY FOR A BRIEF TORNADO IN AN AREA OF
ENHANCED LOW LEVEL HELICITY.
AS A SIDE NOTE...THE LATEST SPC SREF SIGNIFICANT TORNADO PARAMETERS
DOES NOT INDICATE ANY PROBABILITIES IN OUR REGION...WHILE OUR AREA
WAS HIGHLIGHTED DURING THE REVERE DAY. NOW THAT CERTAINLY DOES NOT
MEAN WE CAN/T SEE A BRIEF TORNADO...BUT THE SETUP DOES NOT APPEAR AS
CONDUCIVE AS A FEW WEEKS AGO.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* SPOT SHOWERS POSSIBLE ACROSS INTERIOR ON FRIDAY
* COLD FRONT MOVES ACROSS SUNDAY INTO SUNDAY NIGHT
* BELOW NORMAL TEMPS LATE THIS WEEK WILL TREND CLOSER TO NORMAL BY
EARLY NEXT WEEK
MODELS AND CONFIDENCE...
OVERALL SYNOPTIC GUIDANCE IS IN AGREEMENT FOR THIS TIMEFRAME UNTIL
THE END OF THE PERIOD WHERE MODELS DIVERGE. MODELS IN DECENT
AGREEMENT WITH DEEP TROUGHING OVER THE NORTHEAST CENTERED BY A
SOUTHERN QUEBEC UPPER LOW. THIS CUTOFF LOW WILL REMAIN OVER THE
REGION UNTIL LIFTING NORTHEASTWARD OVER THE WEEKEND. ANTICIPATE A
SERIES OF WEAK SHORTWAVES TO ROTATE THROUGH THE REGION DURING THIS
TIMEFRAME. THERE IS SUBTLE DIFFERENCES IN TIMING BETWEEN THE GFS/EC
AS WELL AS MESO SCALE DIFFERENCES.
BY SUNDAY MODEL GUIDANCE BEGINS TO DIVERGE AS OPERATIONAL GUIDANCE
IS STRUGGLING TO HANDLE THE BREAKDOWN OF THE MORE ZONAL FLOW
OCCURRING OVER THE WEEKEND. REGARDLESS THEY BOTH SHOW SHORTWAVE
MOVING THROUGH ALLOWING FOR A WEAK COLD FRONT ON SUNDAY. HOWEVER BY
EARLY NEXT WEEK HAVE LOW CONFIDENCE ON THE FORECAST BECAUSE OF THE
AMOUNT OF SPREAD. OVERALL TRENDED FORECAST TOWARDS ENSEMBLES AND
PREV FORECAST.
MODERATE CONFIDENCE IN OVERALL FORECAST WITH LOW CONFIDENCE ON EXACT
TIMING OF ANY PRECIP DURING THIS TIMEFRAME. INCREASING CONFIDENCE IN
WARMING TREND FOR NEXT WEEK PER ENSEMBLE TRENDS.
DETAILS...
THURSDAY INTO FRIDAY...
SURFACE LOW PRESSURE SYSTEM WILL MOVE TOWARDS THE MARITIMES ON
THURSDAY LEADING TO A GOOD AMOUNT OF SUBSTANCE IN ITS WAKE. ALTHOUGH
THERE IS A COLD POOL ALOFT...ANTICIPATE A QUIET DAY AS MOISTURE IS
VERY LIMITED. ALTHOUGH CANNOT RULE OUT A FEW DIURNAL CU. EXPECT A
PLEASANT DAY WITH LOW HUMIDITY AND TEMPS BELOW AVERAGE DUE TO THE
COOLER TEMPS ALOFT.
DUE TO DIFFERENCE IN SHORTWAVE TIMING THERE IS LOW CONFIDENCE ON
PRECIP TIMING FOR THURSDAY NIGHT INTO FRIDAY. CUT OFF LOW WILL STILL
BE IN THE VICINITY WITH -12C TEMPS AT 500MB ALOFT. MOISTURE ALOFT
DOES INCREASE ON FRIDAY...HOWEVER THE STRONGER COLD POOL -16C IS
TO THE NORTH OF THE REGION. THEREFORE BELIEVE THAT LOCATIONS NORTH
OF ROUTE 2 HAS THE BEST SHOT OF SEEING A FEW ISOLATED STORMS. BEST
TIMING IS IN THE AFTERNOON AS DIURNAL HEATING WILL STEEPENING THE
LAPSE RATES AND LEAD TO ANOTHER RISK OF LOW TOP CONVECTION. PWAT
VALUES WILL BE AROUND AN INCH SO DO NOT EXPECT FLOODING BEING AN
ISSUE.
THE WEEKEND...
UPPER LEVEL LOW AND COLD POOL ALOFT MOVES NORTHWARD OUT OF THE
REGION LEADING TO A MORE TRANSITION PERIOD FOR THE REGION. AS
HEIGHTS ARE BUILDING APPEARS THAT SATURDAY WILL TREND TO MORE DRY
WEATHER. HOWEVER A NORTHERN STREAM SHORTWAVE AND COLD FRONT COULD
BRING THE NEXT CHANCE OF CONVECTIVE ACTIVITY ON SUNDAY. THERE ARE
MODELS DIFFERENCES ON THE TIMING OF THIS NORTHERN STREAM
SYSTEM...THEREFORE TRENDED TOWARDS A BLEND OF THE GUIDANCE AND WPC.
BELIEVE CONVECTION WILL BE MORE ON THE SUNDAY TIMEFRAME WITH RIDGING
SURFACE/ALOFT APPEARS TO BUILD IN ON MONDAY AND INTO TUESDAY WITH
WARMING TEMPERATURES.
NEXT WEEK...
QUITE A DIFFERENCE IN MODEL SOLUTIONS DURING THIS TIMEFRAME...AS
MENTIONED ABOVE. OVERALL KEPT MAINLY DRY FORECAST GOING HOWEVER
THERE ARE HINTS FOR ANOTHER SYSTEM MOVING THROUGH NEXT WEDNESDAY.
TEMPS LOOK TO BE CLOSE TO SEASONAL OR PERHAPS SLIGHTLY ABOVE DURING
THIS TIMEFRAME.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...TODAY AND TONIGHT...
CIGS MAINLY BASED ON GFS AND ITS MAVMOS. WHILE VSBYS AN EVEN BLEND
OF NAM AND GFS.
THRU 12Z...HEAVY RAIN OVER COASTAL NJ-NYC AND LONG ISLAND AT 06Z
WILL TRACK NORTHEAST INTO CT/RI AND SOUTH OF THE MASS PIKE BY 12Z.
HOURLY RAINFALL RATES OF 1-2" WILL BE POSSIBLE IN THE HEAVIER
CONVECTION. SOUTHEAST WINDS WILL INCREASE TO 15-25 KT. CIGS AND
VSBYS TRENDING TOWARD IFR/MVFR TOWARD 12Z. LLWS ENTERING CT AS
STRONG SOUTHEAST LOW LEVEL JET APPROACHES FROM LONG ISLAND.
AFTER 12Z...HEAVY RAIN CONTINUES TO OVERSPREAD ALL OF CT/RI AND MA
BY LATE MORNING/EARLY AFTERNOON. LOW RISK OF STRONG TSTMS ACROSS
CT/RI AND SOUTHEAST MA 18Z-00Z FROM WEST TO EAST. GUSTY SE WINDS
OF 15-25 KT BEGIN TO RELAX AND SHIFT TO THE SW TOWARD 00Z.
WIDESPREAD IFR/MVFR IN NUMEROUS SHOWERS WITH EMBEDDED HEAVY
DOWNPOURS. LLWS AS STRONG LOW LEVEL SOUTHEAST JET MOVES ACROSS THE
AREA.
TONIGHT...IMPROVING TREND FROM IFR/MVFR TO VFR WITH TIME FROM WEST
TO EAST. RAIN EXITS EASTERN MA DURING THE EARLY EVENING WITH DRY
CONDITIONS ELSEWHERE. SOUTHEAST WINDS SHIFT TO SOUTHWEST.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. LOWER CONFIDENCE ON
HOW FAR NORTH POTENTIAL TSTMS WILL TRAVERSE THIS AFTERNOON AND
EARLY EVENING. TSTMS MOST LIKELY REMAIN SOUTH OF THE TERMINAL
AIRSPACE.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. LOW RISK OF A FEW
STRONG TSTMS EXITING THE NY HUDSON VALLEY INTO CT AFTER 18Z.
STRONG WINDS MAY CONCERN. OTHERWISE HEAVY RAIN MUCH OF TODAY WITH
SOME IMPROVEMENT LATER THIS AFTERNOON.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY THROUGH SATURDAY...HIGH CONFIDENCE. VFR. POSSIBLE SEA
BREEZES ALONG THE COASTLINES.
SUNDAY...MODERATE CONFIDENCE. MVFR DUE TO SHOWERS AND ISO THUNDER.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...TONIGHT AND WEDNESDAY...
TONIGHT AND WEDNESDAY...MODERATE TO HIGH CONFIDENCE. AN ANOMALOUS
SHORTWAVE FOR AUGUST STANDARDS WILL MOVE EAST FROM THE GREAT LAKES.
THIS WILL INDUCE A STRONG SOUTH TO SOUTHEAST LOW LEVEL JET LATE
TONIGHT AND WEDNESDAY. THE RESULT WILL BE SOUTHEAST SCA WIND GUSTS
OF 25 TO 30 KNOTS AND BUILDING SEAS. SCA HEADLINES ARE POSTED FOR
SOME AREAS BEGINNING LATE TONIGHT AND ALL LOCATIONS BY WEDNESDAY.
IN ADDITION...HEAVY RAIN/ISOLATED THUNDERSTORMS AND AREAS OF FOG
WILL REDUCE VISIBILITIES FOR MARINERS. ALSO...THERE REMAINS A LOW
PROBABILITY FOR A WATERSPOUT GIVEN HIGH SHEAR ON A NORTHWARD MOVING
WARM FRONT.
OUTLOOK...THURSDAY THROUGH SUNDAY...HIGH CONFIDENCE.
THURSDAY...WINDS AND SEAS START TO DIMINISH AS LOW PRESSURE MOVES
AWAY FROM THE WATERS. SMALL CRAFT ADVISORIES MAY STILL BE NECESSARY
DURING THIS TIME FOR LINGERING SEAS.
FRIDAY AND SATURDAY...QUIET BOATING WEATHER EXPECTED AS HIGH
PRESSURE STARTS TO BUILD OVER THE WATERS.
SUNDAY...COLD FRONT WILL PASS ACROSS THE WATERS. SEAS WILL INCREASE
BUT SHOULD REMAIN BELOW 5FT.
&&
.TIDES/COASTAL FLOODING...
A COASTAL FLOOD ADVISORY WAS ISSUED FOR THE EAST AND SOUTH COASTS
FOR THE WEDNESDAY HIGH TIDE CYCLE...THAT RUNS FROM LATE MORNING INTO
MID AFTERNOON. EAST TO SOUTHEAST FLOW AHEAD OF A WARM FRONT WILL
ALLOW FOR A 0.5 TO 1 FOOT STORM SURGE. THIS MAY BE ENOUGH TO
PRODUCE SOME POCKETS OF SPLASH OVER OR VERY MINOR COASTAL FLOODING
DURING THE WEDNESDAY NIGH TIDE. THE HEAVY RAIN MAY EXACERBATE THE
PROBLEM A BIT...SLOWING DOWN THE DRAINAGE AFTER THE HIGH TIDE.
OVERALL...THIS WILL BE A NUISANCE EVENT AT WORST BUT A FEW OF THE
MOST VULNERABLE SHORE ROADS COULD BE IMPACTED WITHIN AN HOUR OR TWO
OF HIGH TIDE.
&&
.EQUIPMENT...
THE KBOX RADAR IS CURRENTLY BACK IN SERVICE...BUT THE PART NEEDED TO
PERMANENTLY FIX THE RADAR WILL NOT BE IN UNTIL WEDNESDAY.
THEREFORE...ITS POSSIBLE THAT THE RADAR MAY GO DOWN AGAIN SO USE
WITH CAUTION.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH THROUGH THIS EVENING FOR CTZ002>004.
MA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR MAZ002>021-026.
COASTAL FLOOD ADVISORY FROM 9 AM THIS MORNING TO 4 PM EDT THIS
AFTERNOON FOR MAZ007-015-016-019>022-024.
NH...FLASH FLOOD WATCH THROUGH THIS EVENING FOR NHZ011-012-015.
RI...FLASH FLOOD WATCH THROUGH THIS EVENING FOR RIZ001>007.
COASTAL FLOOD ADVISORY FROM 9 AM THIS MORNING TO 4 PM EDT THIS
AFTERNOON FOR RIZ006-007.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ231>234.
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EDT THIS
EVENING FOR ANZ230.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ236.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ235-237-
254>256.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ250-251.
&&
$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...NOCERA
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...NOCERA/DUNTEN
MARINE...FRANK/DUNTEN
TIDES/COASTAL FLOODING...STAFF
EQUIPMENT...FRANK
AREA FORECAST DISCUSSION
NWS TAUNTON MA
148 AM EDT WED AUG 13 2014
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL BRING HEAVY RAIN ON WEDNESDAY.
AREAS OF URBAN AND LOCALIZED FLASH FLOODING ARE THE MAIN THREATS
WITH A LOW PROBABILITY FOR ISOLATED SEVERE WEATHER. ISOLATED SHOWERS
MAY DEVELOP ACROSS INLAND AREAS DURING THE DAYLIGHT HOURS LATE
THIS WEEK. EXPECT GENERALLY DRY CONDITIONS INTO EARLY THIS
WEEKEND...THEN ANOTHER SHOT FOR SHOWERS MOVES THROUGH THE REGION
SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
130 AM UPDATE...
LATEST MESOSCALE GUIDANCE INCLUDING THE HRRR AND RAP13 STRUGGLING
TO SIMULATE HEAVY RAIN ACROSS COASTAL NJ/NYC AND LONG ISLAND. 00Z
GFS APPEARS TO BE HANDLING THE ACTIVITY BEST. THE GFS PROPROGATES
THIS AREA OF HEAVY RAIN NORTHEAST INTO CT/RI AND SOUTH OF THE MASS
PIKE BY 12Z. THIS SEEMS REASONABLE AS LOW LEVEL JET BEGINS TO
INTENSIFY DURING THIS TIME SOUTH OF NEW ENGLAND. ONE AREA OF
CONCERN IS THE LACK OF RAIN/SHOWERS DOWNSTREAM OF THIS ACTIVITY
ACROSS PA INTO NY STATE. CONVECTION ACROSS COASTAL NJ/NYC AND LONG
ISLAND MAY BE PRECLUDING INSTABILITY AND MOISTURE FROM BEING
ADVECTED NORTHWARD. WILL HAVE TO WATCH HOW THIS EVOLVES AND SEE
HOW 00Z ECMWF AND OTHER GUID SIMULATE THIS CONVECTION. OTHERWISE
NO WHOLESALE CHANGES TO PREVIOUS FORECAST. EARLIER DISCUSSION
BELOW.
================================================================
TORRENTIAL RAINFALL/FLASH FLOODING BEGINNING TO COMMENCE OVER NJ
AS LOW LEVEL JET BEGINS TO FORM AND IS ALSO COLOCATED WITH AREA
OF BEST PRES FALLS AND ALONG WARM FRONTAL BOUNDARY. THIS HAS
INITIATED EMBEDDED CONVECTION WITHIN THIS AREA. MILLVILLE NJ IN
THE SOUTHERN PART OF THE STATE RECEIVED 3.39 INCHES OF RAINFALL
FROM 7 PM TO 9 PM! NONE OF THE HI RES MODEL GUID HANDLING THIS
PARTICULARLY WELL INCLUDING THE HRRR AND RAP13. THE GLOBAL GUID
/GFS AND ECMWF/ IS BETTER BUT IS TOO SLOW IN SPINNING UP
CONVECTION. THIS AREA OF EXCESSIVE RAINFALL IS TRACKING NNE TOWARD
NYC AND SHOULD ARRIVE INTO WESTERN NEW ENGLAND INCLUDING THE
GREATER HARTFORD/SPRINGFIELD AREA AROUND OR AFTER SUNRISE.
FARTHER EASTWARD MESO ANALYSIS CONTINUES TO INDICATE DEEP LAYER OF
DRY AIR ESPECIALLY AROUND 850 MB SOUTH OF NEW ENGLAND THAT STILL
HAS TO BE ADVECTED NORTHWARD. THIS IS ALSO EVIDENT ON THE 00Z OKX
UPPER AIR SOUNDING. THUS STEADY RAINS WILL NOT ARRIVE ACROSS MUCH
OF THE REGION UNTIL AFTER 12Z. HENCE HEAVIEST RAINFALL FOR MUCH OF
THE REGION ARRIVES LATE MORNING INTO EARLY AFTERNOON WED...
POSSIBLY LINGERING AND IMPACTING THE LATE DAY COMMUTE FOR THE
GREATER BOSTON AREA. PREVIOUS FORECAST CAPTURES THESE DETAILS
NICELY SO NO MAJOR CHANGES EXPECTED WITH THIS UPDATE. EARLIER
DISCUSSION BELOW.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
***FLASH FLOOD WATCH FOR THE POTENTIAL OF URBAN AND LOCALIZED FLASH
FLOODING IS THE MAIN CONCERN WEDNESDAY***
1) HEAVY RAIN - FLASH FLOOD THREAT
A LOW LEVEL JET 4 TO 5 STANDARD DEVIATIONS ABOVE NORMAL WILL
COMBINED WITH PWATS BETWEEN 1.75 AND 2 INCHES. THAT IS A CLASSIC
SETUP FOR A SUMMER TIME HEAVY RAIN AND LOCALIZED FLASH FLOOD EVENT.
THE MAIN UNCERTAINTY IS TRYING TO LOCATE WHERE THE HEAVIEST
RAIN/FLOOD THREAT WILL SET UP. GIVEN THAT WE HAVE SOUTH TO
SOUTHEAST FLOW...EXPECT TO SEE THE NORMALLY FAVORED UPSLOPE REGIONS
ALONG THE EAST SLOPES OF THE BERKSHIRES/WORCESTER HILLS AND
MONADNOCKS PERHAPS SEE LOCALLY HIGHER AMOUNTS. THERE MAY ALSO BE A
SECONDARY AREAS ACROSS EASTERN MA/RHODE ISLAND GIVEN A BETTER CHANCE
FOR EMBEDDED THUNDERSTORMS WITH HIGHER INSTABILITY.
OVERALL...EXPECT 1 TO 3 INCHES OF RAINFALL ACROSS MOST AREAS...WITH
LOCALIZED 4 OR 5 INCH AMOUNTS NOT OUT OF THE QUESTION. FORECASTING
QPF AMOUNTS IN THE SUMMER IS NO EASY TASK GIVEN CONVECTIVE FEEDBACK
ISSUES ETC. WE ARE NOT GOING TO BE ABLE TO PINPOINT EXACTLY WHERE
THE BEST CHANCE OF FLASH FLOODING MAY SETUP...OTHER THAN A GENERAL
OVERVIEW GIVEN IN THE PREVIOUS PARAGRAPH. THE MORE IMPORTANT THEME
IS THE POTENTIAL FOR SOME LOCALES TO RECEIVE 2+ INCHES OF RAIN IN
LESS THAN 1 HOUR...LEADING TO THE POTENTIAL FOR SOME URBAN AND
LOCALIZED FLASH FLOODING. THAT IS THE REASON A FLASH FLOOD WATCH IS
IN EFFECT FOR ALL BUT THE CAPE/ISLANDS ON WEDNESDAY.
2) SEVERE WEATHER THREAT
THE BEST SHEAR AND INSTABILITY DO NOT OVERLAP ON WEDNESDAY...SO
SEVERE WEATHER POTENTIAL APPEARS LIMITED. IN ADDITION...RAIN AND
CLOUD COVER WILL LIMIT THE AMOUNT OF INSTABILITY THAT IS ABLE TO
DEVELOP. HOWEVER...THERE IS STILL A LOW PROBABILITY FOR A FEW
STRONG TO SEVERE THUNDERSTORMS ACROSS NORTHERN CT/RHODE ISLAND AND
EASTERN MA. THIS WILL BE DEPENDENT ON WHETHER OR NOT WE CAN MUSTER
ENOUGH INSTABILITY AND HOW FAR NORTH THE SURFACE WARM FRONT MAKES IT
ACROSS THE REGION. ISOLATED STRONG WIND GUSTS WOULD BE THE MAIN
CONCERN. HOWEVER...GIVEN WE WILL HAVE A WARM FRONT TRYING TO LIFT
NORTH THERE IS A LOW PROBABILITY FOR A BRIEF TORNADO IN AN AREA OF
ENHANCED LOW LEVEL HELICITY.
AS A SIDE NOTE...THE LATEST SPC SREF SIGNIFICANT TORNADO PARAMETERS
DOES NOT INDICATE ANY PROBABILITIES IN OUR REGION...WHILE OUR AREA
WAS HIGHLIGHTED DURING THE REVERE DAY. NOW THAT CERTAINLY DOES NOT
MEAN WE CAN/T SEE A BRIEF TORNADO...BUT THE SETUP DOES NOT APPEAR AS
CONDUCIVE AS A FEW WEEKS AGO.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* SPOT SHOWERS POSSIBLE ACROSS INTERIOR BOTH THURSDAY AND FRIDAY
* COLD FRONT MOVES ACROSS SUNDAY INTO SUNDAY NIGHT
* BELOW NORMAL TEMPS LATE THIS WEEK WILL TREND CLOSER TO NORMAL
BY EARLY NEXT WEEK
OVERVIEW AND MODEL PREFERENCES...
MEDIUM RANGE MODELS CONTINUE TO SIGNAL COOLER THAN NORMAL
TEMPERATURES ACROSS THE REGION WITH AMPLIFIED NORTHERN STREAM
PATTERN IN PLACE ACROSS NORTH AMERICA. H5 CUTOFF LOW PRES/COLD POOL
SETS UP ACROSS NORTHERN NEW ENGLAND INTO QUEBEC LATE THIS WEEK INTO
THE WEEKEND. MODELS AND ENSEMBLES START TO FLATTEN OUT THIS PATTERN
LATER THIS WEEKEND...WITH UPPER LEVEL WINDS BECOMING MORE NW. WILL
START TO SEE CHANGES IN THE TIMING OF SYSTEMS ACROSS THE NORTHERN
STREAM FROM ABOUT SUNDAY ONWARD...WHICH THE LONGER RANGE OPERATIONAL
MODELS ARE NOT HANDLING WELL. GFS/EC ENSEMBLES TENDING TO LEAN
TOWARD THE LAST COUPLE OF EC OP SOLUTIONS...WHICH IS ON THE SLOWER
SIDE OF THE FORECAST GUIDANCE IN KEEPING A MORE AMPLIFIED UPPER
LEVEL PATTERN IN PLACE.
LEANED TOWARD A BLEND OF AVAILABLE GUIDANCE INTO THIS WEEKEND...
THEN TRENDED TOWARD THE GFS/EC ENSEMBLES WHICH WERE PRETTY CLOSE TO
WPC GUIDANCE.
DETAILS...
WEDNESDAY NIGHT...
EXPECT FRONTAL SYSTEM/LOW PRES TO PUSH NE INTO MAINE...WHICH WILL
PUSH THE PRECIP WITH IT. WILL SEE LEFTOVER SHOWERS/ISOLD TSTMS
UNTIL AROUND MIDNIGHT...WITH THE BEST CHANCE ACROSS CENTRAL AND
EASTERN AREAS. PRECIP WILL END FROM W-E AFTER MIDNIGHT...WITH
DRIER AND COOLER AIR WORKING IN. OVERNIGHT LOWS WILL FALL TO THE
LOWER-MID 50S ACROSS SW NH/N CENTRAL AND W MA...MAINLY OVER THE
HIGHER TERRAIN... RANGING TO THE MID 60S ACROSS THE MID AND OUTER
CAPE AND THE ISLANDS. DEWPTS WILL ALSO FALL BACK WELL
INLAND...DOWN TO THE MID 50S TOWARD DAYBREAK.
THURSDAY AND FRIDAY...
CUTOFF UPPER LOW WILL SLOWLY SPIN ACROSS NORTHERN NEW ENGLAND
INTO QUEBEC DURING THIS TIMEFRAME. WHILE SOME SURFACE SUBSIDENCE
WILL BE IN PLACE ON LIGHT W-NW WINDS...STILL CAN NOT RULE OUT A
FEW SPOTTY DIURNAL SHOWERS EACH DAY WITH THE COLD POOL ALOFT. DOES
LOOK LIKE BEST CHANCE FOR ANY ACTION WILL BE DURING
FRIDAY...THOUGH...AS THERE APPEARS TO BE A WEAK SHORT WAVE
ROTATING AROUND THE BASE OF THE UPPER TROUGH. ONLY CARRIED SLIGHT
CHANCE POPS MAINLY NEAR AND N OF ROUTE 2. DID NOT MENTION THUNDER
AT THIS TIME...BUT CAN NOT TOTALLY RULE OUT SOME LOW TOPPED
CONVECTION.
HOWEVER...DO EXPECT COMFORTABLE CONDITIONS AS DEWPTS CONTINUE TO
FALL BACK...MAINLY IN THE 50S THOUGH SOME INLAND SPOTS ACROSS S NH/N
CENTRAL AND W MA COULD SEE DEWPTS DOWN IN THE MID-UPPER 40S THU
NIGHT. DAYTIME HIGHS BOTH DAYS WILL MAINLY BE IN THE 70S...THOUGH
SOME SPOTS ON FRIDAY MAY NOT MAKE IT TO 70 ACROSS THE HIGHER TERRAIN
OF SW NH...RUNNING AROUND 5 DEGREES BELOW SEASONAL NORMS.
SATURDAY...
UPPER LEVEL CUTOFF/COLD POOL STUBBORN TO MOVE...BUT LOOKS LIKE IT
FINALLY BEGINS TO SHIFT E TOWARD THE MARITIMES LATER SAT/SAT
NIGHT...AT LEAST ON THIS MODEL SUITE. HAVE RUN WITH DRY CONDITIONS
DURING THE DAY WITH HIGHS AGAIN IN THE 70S REGIONWIDE. AS NW FLOW
TAKES OVER...MIGHT SEE A FEW SHOWERS BEGIN TO APPROACH AS WEAK
SHORT WAVE/SURFACE FRONT MOVES SE LATE SAT NIGHT. ONLY CARRIED
SLIGHT CHANCE POPS AFTER 06Z OVER SW NH.
SUNDAY...
COLD FRONT IN THE UPPER FLOW MOVES ACROSS THE REGION...BUT TIMING
IN QUESTION AS GFS AND EC AT ODDS ON HOW THE UPPER LEVEL FLOW
BREAKS DOWN ACROSS THE EASTERN U.S. THE SURFACE FEATURE DOES TEND
TO WEAKEN AS THE UPPER LEVEL SYSTEM PUSHES THROUGH. CURRENT TIMING
SUGGESTS BEST SHOT WILL OCCUR DURING MAX HEATING OF THE DAY...SO
HAVE CARRIED SCT SHOWERS. ONLY MARGINAL INSTABILITY AT BEST AS THE
FRONT CROSSES...THOUGH NOTING SOME ENHANCEMENT LATER IN THE DAY
INTO EARLY SUN NIGHT AS THE FRONT APPROACHES THE S COAST. HAVE NOT
MENTIONED THUNDER IN THE FORECAST...FOR NOW. HAVE ENDED PRECIP BY
AROUND MIDNIGHT...BUT AGAIN TIMING IN QUESTION.
MONDAY-TUESDAY...
QUITE A DIFFERENCE IN OP MODEL SOLUTIONS DURING THIS TIMEFRAME...
ALL IN THE WAY THEY HANDLE THE BREAKDOWN /OR LACK THEREOF/ OF THE
UPPER LEVEL PATTERN AND MOVEMENT OF A SHORT WAVE IN THE FLATTER H5
PATTERN AROUND THE LATE MONDAY/TUESDAY TIMEFRAME. LEANED CLOSER TO
THE EC MODEL...WHICH WAS IN FAIRLY GOOD AGREEMENT WITH THE GFS/EC
ENSEMBLES. KEPT MAINLY DRY FORECAST GOING...THOUGH DID KEEP IN
SLIGHT CHANCE POPS OVER CENTRAL AND NORTHERN AREAS DURING MONDAY
FOR NOW. TEMPS LOOK TO BE CLOSE TO SEASONAL NORMS DURING THIS
TIMEFRAME.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...TODAY AND TONIGHT...
CIGS MAINLY BASED ON GFS AND ITS MAVMOS. WHILE VSBYS AN EVEN BLEND
OF NAM AND GFS.
THRU 12Z...HEAVY RAIN OVER COASTAL NJ-NYC AND LONG ISLAND AT 06Z
WILL TRACK NORTHEAST INTO CT/RI AND SOUTH OF THE MASS PIKE BY 12Z.
HOURLY RAINFALL RATES OF 1-2" WILL BE POSSIBLE IN THE HEAVIER
CONVECTION. SOUTHEAST WINDS WILL INCREASE TO 15-25 KT. CIGS AND
VSBYS TRENDING TOWARD IFR/MVFR TOWARD 12Z. LLWS ENTERING CT AS
STRONG SOUTHEAST LOW LEVEL JET APPROACHES FROM LONG ISLAND.
AFTER 12Z...HEAVY RAIN CONTINUES TO OVERSPREAD ALL OF CT/RI AND MA
BY LATE MORNING/EARLY AFTERNOON. LOW RISK OF STRONG TSTMS ACROSS
CT/RI AND SOUTHEAST MA 18Z-00Z FROM WEST TO EAST. GUSTY SE WINDS
OF 15-25 KT BEGIN TO RELAX AND SHIFT TO THE SW TOWARD 00Z.
WIDESPREAD IFR/MVFR IN NUMEROUS SHOWERS WITH EMBEDDED HEAVY
DOWNPOURS. LLWS AS STRONG LOW LEVEL SOUTHEAST JET MOVES ACROSS THE
AREA.
TONIGHT...IMPROVING TREND FROM IFR/MVFR TO VFR WITH TIME FROM WEST
TO EAST. RAIN EXITS EASTERN MA DURING THE EARLY EVENING WITH DRY
CONDITIONS ELSEWHERE. SOUTHEAST WINDS SHIFT TO SOUTHWEST.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. LOWER CONFIDENCE ON
HOW FAR NORTH POTENTIAL TSTMS WILL TRAVERSE THIS AFTERNOON AND
EARLY EVENING. TSTMS MOST LIKELY REMAIN SOUTH OF THE TERMINAL
AIRSPACE.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. LOW RISK OF A FEW
STRONG TSTMS EXITING THE NY HUDSON VALLEY INTO CT AFTER 18Z.
STRONG WINDS MAY CONCERN. OTHERWISE HEAVY RAIN MUCH OF TODAY WITH
SOME IMPROVEMENT LATER THIS AFTERNOON.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY THROUGH SATURDAY...HIGH CONFIDENCE. VFR. LOW CHANCE FOR SEA
BREEZES ALONG THE COASTLINES MAINLY FRIDAY/SATURDAY. MAY SEE LOCAL
MVFR CONDITIONS IN SCT SHOWERS ACROSS S NH/N CENTRAL-W MA AFTER
MIDNIGHT SAT NIGHT.
SUNDAY...MODERATE CONFIDENCE. GENERALLY LOW END VFR CONDITIONS.
AREAS OF MVFR CIGS/VSBYS IN SCT SHOWERS DURING THE DAY...WHICH
SHOULD SLOWLY IMPROVE FROM W-E SUN NIGHT.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM...TONIGHT AND WEDNESDAY...
TONIGHT AND WEDNESDAY...MODERATE TO HIGH CONFIDENCE. AN ANOMALOUS
SHORTWAVE FOR AUGUST STANDARDS WILL MOVE EAST FROM THE GREAT LAKES.
THIS WILL INDUCE A STRONG SOUTH TO SOUTHEAST LOW LEVEL JET LATE
TONIGHT AND WEDNESDAY. THE RESULT WILL BE SOUTHEAST SCA WIND GUSTS
OF 25 TO 30 KNOTS AND BUILDING SEAS. SCA HEADLINES ARE POSTED FOR
SOME AREAS BEGINNING LATE TONIGHT AND ALL LOCATIONS BY WEDNESDAY.
IN ADDITION...HEAVY RAIN/ISOLATED THUNDERSTORMS AND AREAS OF FOG
WILL REDUCE VISIBILITIES FOR MARINERS. ALSO...THERE REMAINS A LOW
PROBABILITY FOR A WATERSPOUT GIVEN HIGH SHEAR ON A NORTHWARD MOVING
WARM FRONT.
OUTLOOK...WEDNESDAY NIGHT THROUGH SUNDAY...
WEDNESDAY NIGHT AND THURSDAY...SMALL CRAFTS IN PLACE THROUGH WED
NIGHT ON MOST WATERS BUT WINDS/SEAS WILL DIMINISH OVERNIGHT. MAY
NEED TO EXTEND INTO THU FOR THE OUTER WATERS AS SEAS MAY LINGER AT
AROUND 5-6 FT EARLY BEFORE SUBSIDING.
FRIDAY AND SATURDAY...EXPECT WINDS AND SEAS BELOW SMALL CRAFT
CRITERIA.
SUNDAY...COLD FRONT WILL APPROACH THE WATERS LATE SUN/SUN NIGHT BUT
EXPECT CONDITIONS TO REMAIN BELOW SMALL CRAFT LEVELS.
&&
.TIDES/COASTAL FLOODING...
A COASTAL FLOOD ADVISORY WAS ISSUED FOR THE EAST AND SOUTH COASTS
FOR THE WEDNESDAY HIGH TIDE CYCLE...THAT RUNS FROM LATE MORNING INTO
MID AFTERNOON. EAST TO SOUTHEAST FLOW AHEAD OF A WARM FRONT WILL
ALLOW FOR A 0.5 TO 1 FOOT STORM SURGE. THIS MAY BE ENOUGH TO
PRODUCE SOME POCKETS OF SPLASH OVER OR VERY MINOR COASTAL FLOODING
DURING THE WEDNESDAY NIGH TIDE. THE HEAVY RAIN MAY EXACERBATE THE
PROBLEM A BIT...SLOWING DOWN THE DRAINAGE AFTER THE HIGH TIDE.
OVERALL...THIS WILL BE A NUISANCE EVENT AT WORST BUT A FEW OF THE
MOST VULNERABLE SHORE ROADS COULD BE IMPACTED WITHIN AN HOUR OR TWO
OF HIGH TIDE.
&&
.EQUIPMENT...
THE KBOX RADAR IS CURRENTLY BACK IN SERVICE...BUT THE PART NEEDED TO
PERMANENTLY FIX THE RADAR WILL NOT BE IN UNTIL WEDNESDAY.
THEREFORE...ITS POSSIBLE THAT THE RADAR MAY GO DOWN AGAIN SO USE
WITH CAUTION.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...FLASH FLOOD WATCH FROM 6 AM EDT THIS MORNING THROUGH THIS
EVENING FOR CTZ002>004.
MA...FLASH FLOOD WATCH FROM 6 AM EDT THIS MORNING THROUGH THIS
EVENING FOR MAZ002>021-026.
COASTAL FLOOD ADVISORY FROM 9 AM THIS MORNING TO 4 PM EDT THIS
AFTERNOON FOR MAZ007-015-016-019>022-024.
NH...FLASH FLOOD WATCH FROM 6 AM EDT THIS MORNING THROUGH THIS
EVENING FOR NHZ011-012-015.
RI...FLASH FLOOD WATCH FROM 6 AM EDT THIS MORNING THROUGH THIS
EVENING FOR RIZ001>007.
COASTAL FLOOD ADVISORY FROM 9 AM THIS MORNING TO 4 PM EDT THIS
AFTERNOON FOR RIZ006-007.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ231>234.
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EDT THIS
EVENING FOR ANZ230.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ236.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 AM EDT
THURSDAY FOR ANZ250-251.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...FRANK/EVT
NEAR TERM...NOCERA/EVT
SHORT TERM...FRANK
LONG TERM...EVT
AVIATION...NOCERA/EVT
MARINE...FRANK/EVT
TIDES/COASTAL FLOODING...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
403 AM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* WIND SHIFT TO NORTHEAST WEDNESDAY EVENING.
BMD
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE IS CENTERED ACROSS THE MID MISSOURI VALLEY THIS
EVENING WITH LIGHT FLOW AND VFR CONDITIONS EXPECTED THROUGH THE
OVERNIGHT HOURS. WINDS WILL GENERALLY BE OUT OF THE WEST TO
NORTHWEST THROUGH EARLY TO MID AFTERNOON TOMORROW...THEN A WEAK
TROUGH DROPPING ACROSS THE REGION WILL BACK THE WINDS MORE
PREDOMINATELY TO THE WEST...POSSIBLY SOUTHWEST FOR A PERIOD IN THE
AFTERNOON...BEFORE SHIFTING TO THE NORTHEAST WEDNESDAY EVENING
BEHIND THE TROUGH/LAKE BREEZE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM IN WIND SHIFT TIMING.
* HIGH IN REMAINING FORECAST ELEMENTS.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR. WX NIL.
FRIDAY...VFR. WX NIL. LAKE BREEZE DEVELOPMENT POSSIBLE.
FRIDAY NIGHT THROUGH MONDAY...PERIODIC CHANCES SHRA/TSRA. OCNL
PERIODS OF MVFR CIGS/VIS POSSIBLE.
KREIN
&&
.MARINE...
300 AM CDT
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS LAKE MICHIGAN AS WINDS
AND WAVES DIMINISH BEHIND THE DEPARTING LOW SYSTEM CURRENTLY MOVING
ACROSS THE EASTERN LAKES. A SECONDARY TROUGH WILL WORK ITS WAY SOUTH
ACROSS LAKE MICHIGAN TODAY WITH WINDS PICKING UP SLIGHTLY OUT OF THE
NORTH...ESPECIALLY ACROSS THE NORTH HALF OF THE LAKE WHERE WIND
SPEEDS WILL INCREASE BACK INTO THE 15 TO 25 KT RANGE. HIGH PRESSURE
WILL MOVE ACROSS THE LAKE LATE THURSDAY INTO FRIDAY WITH WINDS THEN
TURNING BACK TO THE SOUTHWEST/SOUTH FRIDAY AND SATURDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
&&
$$
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
336 AM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WIND SHIFT TO NORTHEAST WEDNESDAY EVENING.
BMD
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE IS CENTERED ACROSS THE MID MISSOURI VALLEY THIS
EVENING WITH LIGHT FLOW AND VFR CONDITIONS EXPECTED THROUGH THE
OVERNIGHT HOURS. WINDS WILL GENERALLY BE OUT OF THE WEST TO
NORTHWEST THROUGH EARLY TO MID AFTERNOON TOMORROW...THEN A WEAK
TROUGH DROPPING ACROSS THE REGION WILL BACK THE WINDS MORE
PREDOMINATELY TO THE WEST...POSSIBLY SOUTHWEST FOR A PERIOD IN THE
AFTERNOON...BEFORE SHIFTING TO THE NORTHEAST WEDNESDAY EVENING
BEHIND THE TROUGH/LAKE BREEZE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN WIND SHIFT TIMING.
* HIGH IN REMAINING FORECAST ELEMENTS.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR. WX NIL.
FRIDAY...VFR. WX NIL. LAKE BREEZE DEVELOPMENT POSSIBLE.
FRIDAY NIGHT THROUGH MONDAY...PERIODIC CHANCES SHRA/TSRA. OCNL
PERIODS OF MVFR CIGS/VIS POSSIBLE.
KREIN
&&
.MARINE...
300 AM CDT
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS LAKE MICHIGAN AS WINDS
AND WAVES DIMINISH BEHIND THE DEPARTING LOW SYSTEM CURRENTLY MOVING
ACROSS THE EASTERN LAKES. A SECONDARY TROUGH WILL WORK ITS WAY SOUTH
ACROSS LAKE MICHIGAN TODAY WITH WINDS PICKING UP SLIGHTLY OUT OF THE
NORTH...ESPECIALLY ACROSS THE NORTH HALF OF THE LAKE WHERE WIND
SPEEDS WILL INCREASE BACK INTO THE 15 TO 25 KT RANGE. HIGH PRESSURE
WILL MOVE ACROSS THE LAKE LATE THURSDAY INTO FRIDAY WITH WINDS THEN
TURNING BACK TO THE SOUTHWEST/SOUTH FRIDAY AND SATURDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 4 AM WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
300 AM CDT WED AUG 13 2014
.DISCUSSION...
815 PM CDT
SOME SMALL ADJUSTMENTS MADE TO THE FORECAST THE REMAINDER OF
TONIGHT. THE MOST NOTABLE ONE...ESPECIALLY FOR STARGAZERS HOPING TO
CATCH THE PERSEID METEOR SHOWER...WAS TO INCREASE SKY COVER
SLIGHTLY LATE TONIGHT. AREA OF CLOSE-CELLED CLOUDS ACROSS NORTHERN
MN INTO FAR NORTHWEST WI IS PROGRESSING SOUTH ON AN ANOMALOUSLY
STRONG AND MERIDIONAL UPPER/MID LEVEL JET FOR SUMMERTIME. THE 00Z
INL SOUNDING INDICATED A SATURATED LAYER ABOUT 7000 FT THICK WITH
THIS. LOOKING AT MODEL SOLUTIONS OF MOISTURE ON CORRELATING
THICKNESSES...THEY DO BRING HIGHER MOISTURE INTO NORTHERN IL LATE
TONIGHT. THE RAP IS THE MOST BULLISH AND BELIEVE TOO MUCH AS SOME
THINNING SHOULD OCCUR. HAVE LEANED MORE TOWARD FEW TO SCATTERED
CLOUDS DRIFTING OVER AREA LATER...NAMELY AFTER 2 AM.
DEW POINTS HAVE BEEN SLOW TO FALL WITH MID TO EVEN SOME UPPER 50S
LINGERING IN NORTH CENTRAL IL...WHICH IS A BIT CONCERNING FOR LOWS
FORECAST TO REACH THE UPPER 40S-LOWER 50S. BELIEVE THE AIR MASS
SHOULD ALLOW THE DEW POINTS TO FALL SOME WITH A CONTINUED LIGHT
NORTHERLY WIND...BUT MAYBE NOT ENOUGH FOR CURRENT FORECAST LOWS.
HAVE BUMPED UP A DEGREE OR TWO IN OUTLYING AREAS AT THIS POINT
AND WILL CONTINUE TO MONITOR.
MTF
//PREV DISCUSSION...
307 PM CDT
AFTERNOON GOES VAPOR IMAGERY DEPICTS STRONG MID-LEVEL SHORT WAVE
CONTINUES TO DIG SOUTHEAST ACROSS SOUTHERN LAKE MICHIGAN/NORTHEAST
ILLINOIS AND NORTHWEST INDIANA. RAIN SHOWERS HAVE DECREASED IN
COVERAGE WITH MAINLY SOME LIGHT SPRINKLES STILL ACROSS PARTS OF COOK
LAKE AND PORTER COUNTIES. PRECIP SHOULD COME TO AN END OVER THE NEXT
COUPLE OF HOURS AS THE MID-LEVEL TROUGH AND VORT AXES MOVE SOUTHEAST
OF THE AREA...WITH RISING HEIGHTS AND SUBSIDENCE WORKING TO ERODE
CLOUD COVER FROM THE WEST/NORTHWEST INTO THIS EVENING. DECREASING
CLOUD COVER OVER THE EASTERN HALF OF THE CWA SHOULD OCCUR IN TIME
FOR METEOR SHOWER VIEWING OVERNIGHT. COOLER/DRIER AIR FILTERING INTO
THE REGION FROM THE NORTH...COMBINED WITH DECREASING WINDS TONIGHT
AS SURFACE HIGH PRESSURE DRIFTS EAST ACROSS THE PLAINS AND ALLOWS
WEAKENING OF THE GRADIENT EAST OF THE MISSISSIPPI...WILL ALLOW FOR
TEMPS TO FALL INTO THE LOWER 50S AWAY FROM THE CITY AND EVEN INTO
THE UPPER 40S IN SOME OF THE TYPICALLY COLDER SPOTS.
ON WEDNESDAY...NORTHWEST FLOW CONTINUES ALOFT WITH DEEP TROUGH OVER
EASTERN NORTH AMERICA. GUIDANCE HAS BEEN PERSISTENT IN BRINGING A
SHORT WAVE SOUTHEAST THROUGH THE WESTERN PERIPHERY OF THE EASTERN
TROUGH WITH A WEAK SURFACE REFLECTION AND COLD FRONTAL TROUGH WHICH
PUSHES SOUTH FROM WI AND ACROSS NORTHERN IL/IN DURING THE LATE
AFTERNOON AND EVENING HOURS. MOST MODELS SQUEEZE OUT SOME VERY LIGHT
SPOTTY QPF ALONG/AHEAD OF THE FRONT IN THE AFTERNOON...THOUGH IT
APPEARS THAT MODEL BOUNDARY LAYER MOISTURE IS A BIT OVERDONE WHICH
IN TURN YIELDS WEAK CAPE/MOIST LAYER THAT IS ALSO SUSPECTED TO BE
OVER-FORECAST. THUS HAVE MAINTAINED DRY FORECAST THROUGH WEDNESDAY
WITH FRONTAL PASSAGE. FRONT/TROUGH MAY "BACK-DOOR" INTO FAR
NORTHEAST IL TOWARD EVENING BRINGING A QUICK COOLING INTO THE 60S
ALONG THE LAKE MICHIGAN SHORE ESPECIALLY IN LAKE COUNTY IL.
OTHERWISE...SHOULD BE A GOOD DEAL OF SUNSHINE WITH TEMPS REBOUNDING
TO AROUND 80/LOW 80S ACROSS WESTERN CWA WEDNESDAY...AND IN THE
MID-UPPER 70S FARTHER EAST. COOL 50S (AWAY FROM THE URBAN CORE OF
CHICAGO) EXPECTED BEHIND THE FRONT WEDNESDAY NIGHT...WITH ANOTHER
PLEASANT DAY THURSDAY WITH 70S EAST TO NEAR 80 WEST AS HIGH PRESSURE
BUILDS INTO THE REGION. HIGH PRESSURE REMAINS IN CONTROL INTO FRIDAY
THOUGH THE CENTER OF THE HIGH SLIDES EAST...ALLOWING DEVELOPMENT OF
SOUTHERLY RETURN FLOW AND ASSOCIATED WARM/MOIST ADVECTION ACROSS THE
PLAINS AND MISSISSIPPI VALLEY.
THE EXTENDED FORECAST PERIOD SATURDAY-TUESDAY LOOKS TO HAVE WARMER
TEMPS...BUT ALSO PERIODIC CHANCES OF THUNDERSTORMS AS SOUTHERLY LOW
LEVEL FLOW SETS UP AND SLOW MOVING MID-LEVEL DISTURBANCE MOVES
SLOWLY WEST TO EAST ACROSS THE REGION. TIMING DIFFERENCES DO EXIST
BETWEEN THE GLOBAL RUNS BEYOND THE FRIDAY NIGHT-SATURDAY PERIOD.
GOOD AGREEMENT IN DEVELOPMENT OF SURFACE LOW AND WARM FRONT FROM
NORTHERN MO/IA BORDER EAST INTO IN/OHIO VALLEY REGION WITH PRECIP
PRODUCTION AT VARIOUS TIMES EACH DAY. WITH DETAIL DIFFERENCES
INCREASING INTO THE MONDAY/TUESDAY TIMEFRAME HAVE MAINTAINED A
BLENDED GUIDANCE APPROACH WITH CHANCE POPS AND TEMPS WARMING INTO
THE LOW/MID 80S...THEN COOLING FROM THE NORTH A BIT TUESDAY WITH
HINT OF COLD FRONTAL TROUGH PASSAGE. PROBABLY NOT A TOTAL RAIN-OUT
IN REALITY FOR THE WEEKEND...AND FORECAST WILL BE REFINED AS THE
DETAILS BECOME CLEARER OVER THE NEXT SEVERAL DAYS.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WIND SHIFT TO NORTHEAST WEDNESDAY EVENING.
BMD
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE IS CENTERED ACROSS THE MID MISSOURI VALLEY THIS
EVENING WITH LIGHT FLOW AND VFR CONDITIONS EXPECTED THROUGH THE
OVERNIGHT HOURS. WINDS WILL GENERALLY BE OUT OF THE WEST TO
NORTHWEST THROUGH EARLY TO MID AFTERNOON TOMORROW...THEN A WEAK
TROUGH DROPPING ACROSS THE REGION WILL BACK THE WINDS MORE
PREDOMINATELY TO THE WEST...POSSIBLY SOUTHWEST FOR A PERIOD IN THE
AFTERNOON...BEFORE SHIFTING TO THE NORTHEAST WEDNESDAY EVENING
BEHIND THE TROUGH/LAKE BREEZE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN WIND SHIFT TIMING.
* HIGH IN REMAINING FORECAST ELEMENTS.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR. WX NIL.
FRIDAY...VFR. WX NIL. LAKE BREEZE DEVELOPMENT POSSIBLE.
FRIDAY NIGHT THROUGH MONDAY...PERIODIC CHANCES SHRA/TSRA. OCNL
PERIODS OF MVFR CIGS/VIS POSSIBLE.
KREIN
&&
.MARINE...
300 AM CDT
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS LAKE MICHIGAN AS WINDS
AND WAVES DIMINISH BEHIND THE DEPARTING LOW SYSTEM CURRENTLY MOVING
ACROSS THE EASTERN LAKES. A SECONDARY TROUGH WILL WORK ITS WAY SOUTH
ACROSS LAKE MICHIGAN TODAY WITH WINDS PICKING UP SLIGHTLY OUT OF THE
NORTH...ESPECIALLY ACROSS THE NORTH HALF OF THE LAKE WHERE WIND
SPEEDS WILL INCREASE BACK INTO THE 15 TO 25 KT RANGE. HIGH PRESSURE
WILL MOVE ACROSS THE LAKE LATE THURSDAY INTO FRIDAY WITH WINDS THEN
TURNING BACK TO THE SOUTHWEST/SOUTH FRIDAY AND SATURDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 4 AM WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1232 AM CDT WED AUG 13 2014
.DISCUSSION...
815 PM CDT
SOME SMALL ADJUSTMENTS MADE TO THE FORECAST THE REMAINDER OF
TONIGHT. THE MOST NOTABLE ONE...ESPECIALLY FOR STARGAZERS HOPING TO
CATCH THE PERSEID METEOR SHOWER...WAS TO INCREASE SKY COVER
SLIGHTLY LATE TONIGHT. AREA OF CLOSE-CELLED CLOUDS ACROSS NORTHERN
MN INTO FAR NORTHWEST WI IS PROGRESSING SOUTH ON AN ANOMALOUSLY
STRONG AND MERIDIONAL UPPER/MID LEVEL JET FOR SUMMERTIME. THE 00Z
INL SOUNDING INDICATED A SATURATED LAYER ABOUT 7000 FT THICK WITH
THIS. LOOKING AT MODEL SOLUTIONS OF MOISTURE ON CORRELATING
THICKNESSES...THEY DO BRING HIGHER MOISTURE INTO NORTHERN IL LATE
TONIGHT. THE RAP IS THE MOST BULLISH AND BELIEVE TOO MUCH AS SOME
THINNING SHOULD OCCUR. HAVE LEANED MORE TOWARD FEW TO SCATTERED
CLOUDS DRIFTING OVER AREA LATER...NAMELY AFTER 2 AM.
DEW POINTS HAVE BEEN SLOW TO FALL WITH MID TO EVEN SOME UPPER 50S
LINGERING IN NORTH CENTRAL IL...WHICH IS A BIT CONCERNING FOR LOWS
FORECAST TO REACH THE UPPER 40S-LOWER 50S. BELIEVE THE AIR MASS
SHOULD ALLOW THE DEW POINTS TO FALL SOME WITH A CONTINUED LIGHT
NORTHERLY WIND...BUT MAYBE NOT ENOUGH FOR CURRENT FORECAST LOWS.
HAVE BUMPED UP A DEGREE OR TWO IN OUTLYING AREAS AT THIS POINT
AND WILL CONTINUE TO MONITOR.
MTF
//PREV DISCUSSION...
307 PM CDT
AFTERNOON GOES VAPOR IMAGERY DEPICTS STRONG MID-LEVEL SHORT WAVE
CONTINUES TO DIG SOUTHEAST ACROSS SOUTHERN LAKE MICHIGAN/NORTHEAST
ILLINOIS AND NORTHWEST INDIANA. RAIN SHOWERS HAVE DECREASED IN
COVERAGE WITH MAINLY SOME LIGHT SPRINKLES STILL ACROSS PARTS OF COOK
LAKE AND PORTER COUNTIES. PRECIP SHOULD COME TO AN END OVER THE NEXT
COUPLE OF HOURS AS THE MID-LEVEL TROUGH AND VORT AXES MOVE SOUTHEAST
OF THE AREA...WITH RISING HEIGHTS AND SUBSIDENCE WORKING TO ERODE
CLOUD COVER FROM THE WEST/NORTHWEST INTO THIS EVENING. DECREASING
CLOUD COVER OVER THE EASTERN HALF OF THE CWA SHOULD OCCUR IN TIME
FOR METEOR SHOWER VIEWING OVERNIGHT. COOLER/DRIER AIR FILTERING INTO
THE REGION FROM THE NORTH...COMBINED WITH DECREASING WINDS TONIGHT
AS SURFACE HIGH PRESSURE DRIFTS EAST ACROSS THE PLAINS AND ALLOWS
WEAKENING OF THE GRADIENT EAST OF THE MISSISSIPPI...WILL ALLOW FOR
TEMPS TO FALL INTO THE LOWER 50S AWAY FROM THE CITY AND EVEN INTO
THE UPPER 40S IN SOME OF THE TYPICALLY COLDER SPOTS.
ON WEDNESDAY...NORTHWEST FLOW CONTINUES ALOFT WITH DEEP TROUGH OVER
EASTERN NORTH AMERICA. GUIDANCE HAS BEEN PERSISTENT IN BRINGING A
SHORT WAVE SOUTHEAST THROUGH THE WESTERN PERIPHERY OF THE EASTERN
TROUGH WITH A WEAK SURFACE REFLECTION AND COLD FRONTAL TROUGH WHICH
PUSHES SOUTH FROM WI AND ACROSS NORTHERN IL/IN DURING THE LATE
AFTERNOON AND EVENING HOURS. MOST MODELS SQUEEZE OUT SOME VERY LIGHT
SPOTTY QPF ALONG/AHEAD OF THE FRONT IN THE AFTERNOON...THOUGH IT
APPEARS THAT MODEL BOUNDARY LAYER MOISTURE IS A BIT OVERDONE WHICH
IN TURN YIELDS WEAK CAPE/MOIST LAYER THAT IS ALSO SUSPECTED TO BE
OVER-FORECAST. THUS HAVE MAINTAINED DRY FORECAST THROUGH WEDNESDAY
WITH FRONTAL PASSAGE. FRONT/TROUGH MAY "BACK-DOOR" INTO FAR
NORTHEAST IL TOWARD EVENING BRINGING A QUICK COOLING INTO THE 60S
ALONG THE LAKE MICHIGAN SHORE ESPECIALLY IN LAKE COUNTY IL.
OTHERWISE...SHOULD BE A GOOD DEAL OF SUNSHINE WITH TEMPS REBOUNDING
TO AROUND 80/LOW 80S ACROSS WESTERN CWA WEDNESDAY...AND IN THE
MID-UPPER 70S FARTHER EAST. COOL 50S (AWAY FROM THE URBAN CORE OF
CHICAGO) EXPECTED BEHIND THE FRONT WEDNESDAY NIGHT...WITH ANOTHER
PLEASANT DAY THURSDAY WITH 70S EAST TO NEAR 80 WEST AS HIGH PRESSURE
BUILDS INTO THE REGION. HIGH PRESSURE REMAINS IN CONTROL INTO FRIDAY
THOUGH THE CENTER OF THE HIGH SLIDES EAST...ALLOWING DEVELOPMENT OF
SOUTHERLY RETURN FLOW AND ASSOCIATED WARM/MOIST ADVECTION ACROSS THE
PLAINS AND MISSISSIPPI VALLEY.
THE EXTENDED FORECAST PERIOD SATURDAY-TUESDAY LOOKS TO HAVE WARMER
TEMPS...BUT ALSO PERIODIC CHANCES OF THUNDERSTORMS AS SOUTHERLY LOW
LEVEL FLOW SETS UP AND SLOW MOVING MID-LEVEL DISTURBANCE MOVES
SLOWLY WEST TO EAST ACROSS THE REGION. TIMING DIFFERENCES DO EXIST
BETWEEN THE GLOBAL RUNS BEYOND THE FRIDAY NIGHT-SATURDAY PERIOD.
GOOD AGREEMENT IN DEVELOPMENT OF SURFACE LOW AND WARM FRONT FROM
NORTHERN MO/IA BORDER EAST INTO IN/OHIO VALLEY REGION WITH PRECIP
PRODUCTION AT VARIOUS TIMES EACH DAY. WITH DETAIL DIFFERENCES
INCREASING INTO THE MONDAY/TUESDAY TIMEFRAME HAVE MAINTAINED A
BLENDED GUIDANCE APPROACH WITH CHANCE POPS AND TEMPS WARMING INTO
THE LOW/MID 80S...THEN COOLING FROM THE NORTH A BIT TUESDAY WITH
HINT OF COLD FRONTAL TROUGH PASSAGE. PROBABLY NOT A TOTAL RAIN-OUT
IN REALITY FOR THE WEEKEND...AND FORECAST WILL BE REFINED AS THE
DETAILS BECOME CLEARER OVER THE NEXT SEVERAL DAYS.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WIND SHIFT TO NORTHEAST WEDNESDAY EVENING.
BMD
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE IS CENTERED ACROSS THE MID MISSOURI VALLEY THIS
EVENING WITH LIGHT FLOW AND VFR CONDITIONS EXPECTED THROUGH THE
OVERNIGHT HOURS. WINDS WILL GENERALLY BE OUT OF THE WEST TO
NORTHWEST THROUGH EARLY TO MID AFTERNOON TOMORROW...THEN A WEAK
TROUGH DROPPING ACROSS THE REGION WILL BACK THE WINDS MORE
PREDOMINATELY TO THE WEST...POSSIBLY SOUTHWEST FOR A PERIOD IN THE
AFTERNOON...BEFORE SHIFTING TO THE NORTHEAST WEDNESDAY EVENING
BEHIND THE TROUGH/LAKE BREEZE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN WIND SHIFT TIMING.
* HIGH IN REMAINING FORECAST ELEMENTS.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR. WX NIL.
FRIDAY...VFR. WX NIL. LAKE BREEZE DEVELOPMENT POSSIBLE.
FRIDAY NIGHT THROUGH MONDAY...PERIODIC CHANCES SHRA/TSRA. OCNL
PERIODS OF MVFR CIGS/VIS POSSIBLE.
KREIN
&&
.MARINE...
252 PM CDT
WITH LOW PRESSURE JUST NORTHEAST OF THE LAKE AND A FAIRLY TIGHT
PRESSURE GRADIENT OVER THE LAKE...WINDS AND WAVES DID
INCREASE/BUILD ACROSS THE ENTIRE LAKE. BOTH BUOY AND SHIP OBS HAVE
REPORTED AROUND GALES OR SLIGHTLY HIGHER OVER THE LAST COUPLE OF
HOURS...WITH TO 30 KT WINDS BEING REPORTED ELSEWHERE. GRADIENT
OVER THE LAKE WILL BEGIN WEAKENING THIS AFTERNOON WITH SPEEDS
DIMINISHING THROUGH THE EVENING TIME FRAME. WILL CANCEL/EXPIRE THE
GALE WARNING IN PLACE THROUGH 20Z AS THE STRONGEST WINDS SHOULD BE
OVER. WILL LIKELY MAKE MENTION OF A FEW GALE FORCE GUSTS FOR THE
REMAINDER OF THE AFTERNOON IN THE GLF NORTH HALF...AS STRONGER
WINDS JUST OFF THE SURFACE COULD STILL MIX DOWN OVER THE NEXT
COUPLE OF HOURS. SCA TIMING STILL APPEARS TO BE IN GOOD SHAPE WITH
THE WINDS DIMINISHING THIS AFTERNOON...BUT WITH HIGHER WAVES STILL
LINGERING THROUGH TONIGHT AND EARLY WEDNESDAY MORNING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 4 AM WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS GOODLAND KS
226 AM MDT WED AUG 13 2014
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 225 AM MDT WED AUG 13 2014
LATEST WV IMAGERY AND RAP ANALYSIS SHOW AMPLIFIED 594 DM RIDGE
CENTERED OVER THE SOUTHERN PLAINS EXTENDING NORTH ACROSS THE CENTRAL
PLAINS/CENTRAL ROCKIES INTO SOUTHERN CANADA. AT THE SURFACE THE LEE
TROUGH IS DEEPENING OVER EASTERN COLORADO WITH HIGH PRESSURE
BEGINNING TO SHIFT TOWARD EASTERN KANSAS.
TODAY-THURSDAY NIGHT...ANOTHER VERY WARM AND DRY DAY IS EXPECTED
TODAY AS H5 RIDGE CONTINUE TO DOMINATE PATTERN OVER THE CWA...AND
MAIN STORM TRACK REMAINS WELL OUTSIDE OUR AREA OF CONCERN. BY MIDDAY
THURSDAY THE NORTHERN EXTENT OF THE RIDGE WILL BEGIN TO FLATTEN IN
RESPONSE TO A SHORTWAVE TROUGH MOVING OUT OF THE FOUR CORNERS REGION
AND INTO THE NORTHERN PLAINS. WHILE INSTABILITY INCREASES...SOUNDING
SHOW HIGH TD DEPRESSIONS BELOW 500MB THROUGH AT LEAST EARLY THURSDAY
AFTERNOON...WHICH COULD LIMIT PRECIPITATION REACHING THE GROUND IN
ALL BUT THE STRONGEST UPDRAFTS UNTIL MID AFTERNOON. BETTER
LIFT/INSTABILITY SHOULD SUPPORT BETTER THUNDERSTORM COVERAGE BY LATE
THURSDAY AFTERNOON AND ESPECIALLY THURSDAY NIGHT...AND MODELS SHOW A
GOOD PRECIP SIGNAL DURING THESE PERIODS. I KEPT SLIGHT CHANCE POPS
IN PLACE MIDDAY THURSDAY...THOUGH CONFIDENCE WASNT HIGH FOR
INITIATION THAT EARLY AND TRENDED POPS UP BY THE EVENING OVERNIGHT
HOURS. BY THURSDAY NIGHT BETTER CAPE PROFILES AND INCREASING PWATS
WOULD SUPPORT THE POSSIBILITY OF LOCALIZED HEAVY RAIN...HOWEVER
THREAT IS UNCERTAIN AT THIS RANGE ESPECIALLY WITH BETTER STORM
MOTIONS. SHEER WILL BE DECENT...HOWEVER CAPE IS MARGINAL...SO
ELEVATED SEVERE THREAT IS UNCERTAIN.
FRIDAY-FRIDAY NIGHT...RIDGE REMAINS IN PLACE OVER THE SOUTHERN
PLAINS WITH NORTHWEST FLOW ALLOWING WEAK MID LEVEL VORTICITY TO
ROTATE THROUGH THE NORTHERN PLAINS. AS PRECIP COMES TO AN END WITH
DEPARTING SHORTWAVE ONLY WEAK FORCING WILL BE IN PLACE. MODERATE
INSTABILITY WILL BUILD BACK OVER THE CWA WITH DAYTIME HEATING...AND
THERE CONTINUES TO BE A WEAK PRECIP SIGNAL BETWEEN THE GFS AND
ECMWF...SO WHILE CONFIDENCE IS NOT HIGH WE WILL SEE MUCH
THUNDERSTORM ACTIVITY SLIGHT CHANCE POPS STILL SEEM REASONABLE FOR
NOW.
REGARDING TEMPS...GUIDANCE CONTINUES TO SHOW GOOD WAA ALONG EASTERN
SIDE OF LEE TROUGH THROUGH THURSDAY. LOW TO MID 90S FOR MOST
LOCATIONS TODAY AND THURSDAY SEEM REASONABLE...THOUGH INCREASING
CLOUD COVER COULD LIMIT WARMING SOME ON THURSDAY. FRIDAY TEMPS COULD
BE A BIT COOLER BEHIND TROUGH AND BUILDING NW FLOW...HOWEVER
GUIDANCE CONTINUES TO SHOW DECENT RECOVERY OF TEMPS ALOFT WITH LEE
TROUGH QUICKLY BUILDING BACK OVER EASTERN COLORADO. I USED CONSENSUS
FOR FRIDAY AS A BEST GUESS WHICH FAVORS SEASONAL TEMPS AROUND 90F.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 225 AM MDT WED AUG 13 2014
AN UPPER LEVEL RIDGE WILL BE POSITIONED OVER THE SOUTHWEST PORTION
OF THE CONUS WITH WESTERLY/NORTHWESTERLY FLOW ALOFT ACROSS THE
CENTRAL HIGH PLAINS. MEDIUM RANGE GUIDANCE DISPLAYS SOME FAIRLY
SIGNIFICANT DIFFERENCES WITH TIMING AND AMPLITUDE OF THE A SHORTWAVE
TROUGH THAT WILL PASS THROUGH ON MONDAY. THE GFS IS THE MOST
AMPLIFIED AND HAS THE STRONGEST FORCING BUT SEVERAL GFS ENSEMBLE
MEMBERS DISPLAY LESS AMPLITUDE SIMILAR TO THE DETERMINISTIC ECMWF.
THIS LEADS TO UNCERTAINTY WITH REGARDS TO AMOUNT OF CONVECTION.
ASIDE FROM THIS SHORTWAVE THE PATTERN REMAINS FAIRLY BENIGN WITH
NEAR OR SLIGHTLY ABOVE NORMAL TEMPERATURES THROUGH THE ENTIRE
PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1100 PM MDT TUE AUG 12 2014
VFR EXPECTED FOR BOTH KGLD AND KMCK. WINDS FROM TAF ISSUANCE
THROUGH 18Z FROM THE EAST/SOUTHEAST AROUND 10KTS. FROM 19Z THROUGH
THE REST OF THE TAF PERIOD GUSTS OF 15-20KTS EXPECTED. NO
PRECIPITATION EXPECTED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1100 PM MDT TUE AUG 12 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 152 PM MDT TUE AUG 12 2014
A RIDGE WILL BE OVER THE ROCKIES TONIGHT AND A SURFACE TROUGH OVER
EASTERN COLORADO. SOME SCATTERED CUMULUS HAVE DEVELOPED OVER
EASTERN COLORADO. CURRENT RADAR WITH NO RETURNS. THE HRRR AND NAM
BOTH DO NOT INDICATE STORMS FOR THIS EVENING AND THAT SEEMS
REASONABLE BASED ON VERY DRY FORECAST SOUNDINGS OVER THE AREA.
ALSO WATER VAPOR IMAGERY SHOWING STRONG SUBSIDENCE EAST OF THE
CENTRAL ROCKIES. POPS WILL BE NIL TONIGHT AND AGAIN ON WEDNESDAY
AS SUBSIDENCE CONTINUES. LOW TEMPERATURES TONIGHT WILL BE IN THE
LOWER 60S AND MAX TEMPERATURES WEDNESDAY AROUND 90.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 152 PM MDT TUE AUG 12 2014
A DRY FORECAST CONTINUES THROUGH WEDNESDAY NIGHT AND EARLY THURSDAY
AS THE RIDGE AND SUBSIDENCE CONTINUES OVER THE HIGH PLAINS. BY
THURSDAY AFTERNOON THE RIDGE BREAKS DOWN SOME AS A SHORTWAVES
MOVES INTO THE AREA. THIS SHORTWAVE WILL CONTINUE MOVING ACROSS
THE FA THURSDAY NIGHT INTO FRIDAY MORNING. STORMS SHOULD INITIATE
ON A SURFACE TROUGH IN EASTERN COLORADO THURSDAY AFTERNOON AND
THEN SPREAD EAST ACROSS THE REST OF THE FA THURSDAY NIGHT. CHANCE
POPS LOOK GOOD FOR THIS EVENT. STORMS WILL LIKELY LINGER IN THE
EASTERN FA EARLY FRIDAY MORNING WITH SUBSIDENCE MOVING INTO THE FA
FROM WEST TO EAST. CONFIDENCE IS NOT HIGH FOR STORMS FRIDAY
AFTERNOON BUT CANNOT RULE OUT AT LEAST AN ISOLATED STORM OR TWO SO
WILL LOWER POPS TO SLIGHT CHANCE.
IN THE EXTENDED...FROM FRIDAY NIGHT THROUGH TUESDAY...A BROAD
RIDGE WILL BE OVER THE WESTERN CONUS EXTENDING INTO THE HIGH
PLAINS. NUMEROUS WEAK DISTURBANCES WILL MOVE THROUGH THE RIDGE
INTO THE HIGH PLAINS. THIS WILL PROVIDE POTENTIAL FOR STORMS EACH
AFTERNOON AND EVENING ACROSS THE FA THROUGH TUESDAY. CONSEQUENTLY, PLAN
TO HAVE AT LEAST A SLIGHT CHANCE OF STORMS EACH DAY. MAX
TEMPERATURES WILL REACH THE LOWER 90S EACH DAY. MIN TEMPERATURES
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1100 PM MDT TUE AUG 12 2014
VFR EXPECTED FOR BOTH KGLD AND KMCK. WINDS FROM TAF ISSUANCE
THROUGH 18Z FROM THE EAST/SOUTHEAST AROUND 10KTS. FROM 19Z THROUGH
THE REST OF THE TAF PERIOD GUSTS OF 15-20KTS EXPECTED. NO
PRECIPITATION EXPECTED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
AVIATION...99
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1251 AM EDT Wed Aug 13 2014
...Updated Aviation Discussion...
...Forecast Update...
Issued at 930 PM EDT Tue Aug 12 2014
Updating products to remove shower wording over the northeast. Had a
few small cells move just northeast of the region, but nothing is
going on in our area at this time. Some drier air is working into
the area, but with winds dying down, we should see some sites drop
into the upper 50s. This could be low enough for a few patches of
fog to develop toward daybreak, so have that still in for all but
the Bluegrass. Up there, we should see a swath of clouds come in
from the northwest, in association with an upper trough axis
swinging through the region. Latest RUC shows the clouds there may
break up briefly after midnight, but redevelop toward daybreak. Will
lean this way and keep sky grids in the partly cloudy range through
the night.
.SHORT TERM (Now through Sunday)...
Issued at 250 PM EDT Tue Aug 12 2014
A cold front has pushed through the region this afternoon. This
front along with cloud cover associated with an upper trough and the
front have kept our temps at bay in the upper 70s and lower 80s
today. Congested cu from the upper trough will continue to sweep
across our southern Indiana and extreme northern Kentucky counties
possibly causing an isld sprinkle or brief shower this evening.
However, the rest of the night looks dry with the upper trough
moving NE from the Great Lakes into southeast Canada. Drier air
will continue to advect in from the NW so don`t think fog will be a
big issue tonight. However, could see some patchy light fog in fog
prone areas of the east central KY towards morning where low levels
will remain a bit more saturated. Low temps will be in the upper
50s/lower 60s.
For Wednesday, expect a dry, cooler than normal day. Mostly sunny
skies will be the rule as sfc high pressure builds in from the
west. High temps should range from 77-82.
Wednesday night should be a decent rad cooling night under mostly
clear skies. A weak upper level impulse may approach from the north
late Wed night/Thurs morning which may create a more mixy
environment limiting fog potential. Still feel that at least patchy
fog is possible in our fog prone areas though with mostly clear
skies, good subsidence, and very light or calm winds for a good
portion of the night. Expect low temps in the mid 50s to lower 60s.
.LONG TERM (Sunday night through Friday)...
Issued at 247 PM EDT Tue Aug 12 2014
The long term period will start out with somewhat cooler and drier
weather before a return to higher temps and scattered rain chances.
Through Sunday the upper level trough over the eastern CONUS will
slowly shift off to the northeast. This will keep us in
northwesterly flow aloft. High pressure at the surface will be
building in Thursday and slowly shift off to the east through the
weekend.
There is just a bit of uncertainty in the Thursday forecast as a
vortmax will dive through the northwesterly flow and models try to
develop very light and isolated showers. However, with the high
pressure building in and a drier airmass, will keep the forecast dry
for now. Dry weather will continue through Saturday. Highs will be
in the lower to mid 80s Thursday and Friday with a warm up to the
mid to upper 80s on Saturday. Lows will range from the upper 50s to
mid 60s.
By the end of the weekend, the models develop a stronger shortwave
in the upper level flow. this will bring a better chance for precip
Sunday into Monday. The models show a difference in timing with this
wave, so for now will keep pops in the 20-30% range. Another system
will bring a second round of precipitation Monday into Tuesday.
Temperatures will be close to seasonal normals for this time of year
with highs in the mid to upper 80s and lows in the upper 60s to
lower 70s.
&&
.AVIATION (06Z TAF Update)...
Issued at 1249 AM EDT Wed Aug 13 2014
Cold pool strato-cu shield over Indiana made some minor inroads into
Kentucky earlier in the evening, but recently has been eroding as
the cyclonic curvature in the low-level winds has been lost. SDF and
BWG should stay clear through the night. LEX is closer to the edge,
but this looks more like Ohio`s stratus event, which actually opens
the door for potential fog formation. Current temp is just 2 degrees
away from crossing over the afternoon dewpoint, and should cool
another few degrees. However, good drying has occurred in the past
several hours, and low-level wind fields remain a bit mixy.
Therefore will lean on the GFS LAMP guidance and go with a few hrs
of MVFR visibilities around daybreak, but will not carry any low
ceilings.
VFR across the board by midday with NW winds just under 10 kt. Do
expect a cu field but it should remain scattered. With high pressure
better entrenched by sundown, expect to go clear and calm in the
evening.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........RJS
Short Term.....AMS
Long Term......EER
Aviation.......RAS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
432 AM EDT WED AUG 13 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT TUE AUG 12 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW JUST
EAST OF THE SAULT RESULTING IN NNW FLOW FROM NW ONTARIO THROUGH THE
WRN GREAT LAKES. THE BACK EDGE OF THE CLOUDS ASSOCIATED WITH THE LOW
HAD MOVED TO NEAR SAW-IMT LEAVING CLEAR SKIES OVER THE WEST AND
THICK CLOUDS WITH A FEW SPRINKLES OVER THE ERN CWA. AN UPSTREAM
CLIPPER SHORTWAVE TROUGH AND COLD FRONT THAT SUPPORTED A FEW LIGHT
SHOWERS OR SPRINKLES WAS MOVING THROUGH NW ONTARIO.
TONIGHT...EXPECT THAT SOME LIGHT SHOWERS OR SPRINKLES ASSOCIATED
WITH THE NW ONTARIO SHRTWV MAY MOVE INTO WRN LAKE SUPERIOR AND
POSSIBLY WRN UPPER MI. HOWEVER...SINCE FORCING WITH THE SHRTWV IS
WEAK AND LITTLE MOISTURE/INSTABILITY IS AVAILABLE DURING THE
OVERNIGHT...NO PCPN MENTION WAS ADDED TO THE FCST.
WED...BEHIND THE COLD FRONT...NNW WINDS WILL AGAIN INCREASE WHICH
COULD SUPPORT AN INCREASE IN UPSLOPE CLOUDS OVER N CNTRL UPPER MI.
TEMPS WILL REMAIN BELOW NORMAL WITH HIGHS FROM THE MID 60S NORTH TO
THE LOWER 70S SOUTH. SWIM RISK WILL AGAIN BE HIGH AS 3 TO 5 FOOT
WAVES ARE EXPECTED INTO MARQUETTE AND ALGER COUNTIES BY AFTERNOON.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 335 AM EDT WED AUG 13 2014
THE UPPER LOW CURRENTLY JUST E OF THE CWA WILL DEEPEN WHILE MOVING
INTO SERN QUEBEC BY 12Z THU...AND WILL REMAIN NEARLY STATIONARY
THROUGH AT LEAST FRI /MODELS DISAGREE ON LOCATION AFTER FRIDAY/.
MEANWHILE...THE WELL DEFINED UPPER RIDGE CURRENTLY OVER THE ROCKIES
AND INTO WRN CANADA WILL SHIFT SLIGHTLY E BY THU MORNING...WITH A
PORTION OF THAT RIDGE EXTENDING FROM THE NRN PLAINS TO HUDSON BAY.
BETWEEN THESE TWO SYSTEMS...A SFC RIDGE WILL BE IN PLACE THU AND THU
NIGHT. NO PRECIP IS EXPECTED THU AND THU NIGHT. IT DOES LOOK LIKE WE
WILL MIX INTO A VERY DRY AIRMASS ON THU /1000-500MB RH AROUND 20
PERCENT/...WHICH WILL ALLOW MIN RH VALUES NEAR 30 PERCENT OVER ERN
UPPER MI AND IN THE LOW TO MID 30 PERCENT RANGE ELSEWHERE. WINDS
WILL BE GUSTY OVER THE ERN CWA...WITH GUSTS TO 20KTS OVER ERN UPPER
MI IN THE AFTERNOON. FIRE WX WILL BE MORE OF A CONCERN OVER ERN
UPPER MI.
PRECIP CHANCES INCREASE FRI INTO SAT AS A SHORTWAVE TROUGH MOVES
OVER THE AREA THROUGH THE WEAKENING UPPER RIDGE FRI AND A STRONG
SHORTWAVE TROUGH AND SFC COLD FRONT MOVE THROUGH LATE FRI NIGHT INTO
SAT. WITH MOISTURE INCREASING DURING THIS TIME AND BETTER FORCING
WITH THE SECOND FEATURE...HAVE GREATEST POPS THEN.
UNCERTAINTY INCREASES THROUGH THE REST OF THE FORECAST PERIOD...BUT
MODELS DO HINT THAT HIGH PRESSURE WILL BE IN CONTROL SUN INTO
MON...LEAVING THE AREA DRY. PRECIP MAY TRY TO MAKE A REAPPEARANCE
LATE MON INTO TUE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1205 AM EDT WED AUG 13 2014
HIGH PRESSURE AND DRIER AIR MOVING INTO THE WESTERN U.P. WILL BRING
VFR CONDITIONS TO ALL SITES THROUGH THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 433 AM EDT WED AUG 13 2014
LAKE SUPERIOR WILL REMAIN STUCK BETWEEN EXITING LOW PRESSURE OVER S
QUEBEC AND A NEARING HIGH FROM W ONTARIO...WHICH WILL HELP KEEP
N-NNW WINDS NEAR 25KTS GOING OVER MAINLY THE E HALF OF LAKE
SUPERIOR. EXPECT THE HIGH TO SETTLE ACROSS THE UPPER GREAT LAKES
TONIGHT THROUGH FRIDAY. NW GUSTS NEAR 20KTS WILL STILL BE POSSIBLE
OVER FAR E LAKE SUPERIOR THURSDAY. AN ELONGATED TROUGH STRETCHING
FROM ND THROUGH ONTARIO AND CENTRAL QUEBEC FRIDAY AFTERNOON WILL
SINK ACROSS LAKE SUPERIOR FRIDAY NIGHT INTO SATURDAY. BEHING THE
TROUGH...HIGH PRESSURE OVER S CENTRAL CANADA SATURDAY WILL THEN
SLIDE ACROSS ONTARIO AND LAKE SUPERIOR FOR SUNDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT FROM 8 AM EDT THIS MORNING THROUGH THIS
EVENING FOR MIZ005-006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
335 AM EDT WED AUG 13 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT TUE AUG 12 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW JUST
EAST OF THE SAULT RESULTING IN NNW FLOW FROM NW ONTARIO THROUGH THE
WRN GREAT LAKES. THE BACK EDGE OF THE CLOUDS ASSOCIATED WITH THE LOW
HAD MOVED TO NEAR SAW-IMT LEAVING CLEAR SKIES OVER THE WEST AND
THICK CLOUDS WITH A FEW SPRINKLES OVER THE ERN CWA. AN UPSTREAM
CLIPPER SHORTWAVE TROUGH AND COLD FRONT THAT SUPPORTED A FEW LIGHT
SHOWERS OR SPRINKLES WAS MOVING THROUGH NW ONTARIO.
TONIGHT...EXPECT THAT SOME LIGHT SHOWERS OR SPRINKLES ASSOCIATED
WITH THE NW ONTARIO SHRTWV MAY MOVE INTO WRN LAKE SUPERIOR AND
POSSIBLY WRN UPPER MI. HOWEVER...SINCE FORCING WITH THE SHRTWV IS
WEAK AND LITTLE MOISTURE/INSTABILITY IS AVAILABLE DURING THE
OVERNIGHT...NO PCPN MENTION WAS ADDED TO THE FCST.
WED...BEHIND THE COLD FRONT...NNW WINDS WILL AGAIN INCREASE WHICH
COULD SUPPORT AN INCREASE IN UPSLOPE CLOUDS OVER N CNTRL UPPER MI.
TEMPS WILL REMAIN BELOW NORMAL WITH HIGHS FROM THE MID 60S NORTH TO
THE LOWER 70S SOUTH. SWIM RISK WILL AGAIN BE HIGH AS 3 TO 5 FOOT
WAVES ARE EXPECTED INTO MARQUETTE AND ALGER COUNTIES BY AFTERNOON.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 335 AM EDT WED AUG 13 2014
THE UPPER LOW CURRENTLY JUST E OF THE CWA WILL DEEPEN WHILE MOVING
INTO SERN QUEBEC BY 12Z THU...AND WILL REMAIN NEARLY STATIONARY
THROUGH AT LEAST FRI /MODELS DISAGREE ON LOCATION AFTER FRIDAY/.
MEANWHILE...THE WELL DEFINED UPPER RIDGE CURRENTLY OVER THE ROCKIES
AND INTO WRN CANADA WILL SHIFT SLIGHTLY E BY THU MORNING...WITH A
PORTION OF THAT RIDGE EXTENDING FROM THE NRN PLAINS TO HUDSON BAY.
BETWEEN THESE TWO SYSTEMS...A SFC RIDGE WILL BE IN PLACE THU AND THU
NIGHT. NO PRECIP IS EXPECTED THU AND THU NIGHT. IT DOES LOOK LIKE WE
WILL MIX INTO A VERY DRY AIRMASS ON THU /1000-500MB RH AROUND 20
PERCENT/...WHICH WILL ALLOW MIN RH VALUES NEAR 30 PERCENT OVER ERN
UPPER MI AND IN THE LOW TO MID 30 PERCENT RANGE ELSEWHERE. WINDS
WILL BE GUSTY OVER THE ERN CWA...WITH GUSTS TO 20KTS OVER ERN UPPER
MI IN THE AFTERNOON. FIRE WX WILL BE MORE OF A CONCERN OVER ERN
UPPER MI.
PRECIP CHANCES INCREASE FRI INTO SAT AS A SHORTWAVE TROUGH MOVES
OVER THE AREA THROUGH THE WEAKENING UPPER RIDGE FRI AND A STRONG
SHORTWAVE TROUGH AND SFC COLD FRONT MOVE THROUGH LATE FRI NIGHT INTO
SAT. WITH MOISTURE INCREASING DURING THIS TIME AND BETTER FORCING
WITH THE SECOND FEATURE...HAVE GREATEST POPS THEN.
UNCERTAINTY INCREASES THROUGH THE REST OF THE FORECAST PERIOD...BUT
MODELS DO HINT THAT HIGH PRESSURE WILL BE IN CONTROL SUN INTO
MON...LEAVING THE AREA DRY. PRECIP MAY TRY TO MAKE A REAPPEARANCE
LATE MON INTO TUE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1205 AM EDT WED AUG 13 2014
HIGH PRESSURE AND DRIER AIR MOVING INTO THE WESTERN U.P. WILL BRING
VFR CONDITIONS TO ALL SITES THROUGH THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 PM EDT TUE AUG 12 2014
NORTH WINDS GUSTING TO MORE THAN 25 KTS ACROSS THE EASTERN PART OF
THE LAKE WILL DIMINISH THIS EVENING AS THE PRES GRADIENT WEAKENS. A
REINFORCING COLD FRONT WILL PUSH ACROSS THE LAKE ON WEDNESDAY
ALLOWING NORTHWESTERLY WIND GUSTS OF UP TO 25 KTS WEDNESDAY
AFTERNOON. WINDS SHOULD DIMINISH BY LATE WEDNESDAY AND THEN REMAIN
BELOW 15 KTS INTO THE UPCOMING WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT FROM 8 AM EDT THIS MORNING THROUGH THIS
EVENING FOR MIZ005-006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1205 AM EDT WED AUG 13 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT TUE AUG 12 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW JUST
EAST OF THE SAULT RESULTING IN NNW FLOW FROM NW ONTARIO THROUGH THE
WRN GREAT LAKES. THE BACK EDGE OF THE CLOUDS ASSOCIATED WITH THE LOW
HAD MOVED TO NEAR SAW-IMT LEAVING CLEAR SKIES OVER THE WEST AND
THICK CLOUDS WITH A FEW SPRINKLES OVER THE ERN CWA. AN UPSTREAM
CLIPPER SHORTWAVE TROUGH AND COLD FRONT THAT SUPPORTED A FEW LIGHT
SHOWERS OR SPRINKLES WAS MOVING THROUGH NW ONTARIO.
TONIGHT...EXPECT THAT SOME LIGHT SHOWERS OR SPRINKLES ASSOCIATED
WITH THE NW ONTARIO SHRTWV MAY MOVE INTO WRN LAKE SUPERIOR AND
POSSIBLY WRN UPPER MI. HOWEVER...SINCE FORCING WITH THE SHRTWV IS
WEAK AND LITTLE MOISTURE/INSTABILITY IS AVAILABLE DURING THE
OVERNIGHT...NO PCPN MENTION WAS ADDED TO THE FCST.
WED...BEHIND THE COLD FRONT...NNW WINDS WILL AGAIN INCREASE WHICH
COULD SUPPORT AN INCREASE IN UPSLOPE CLOUDS OVER N CNTRL UPPER MI.
TEMPS WILL REMAIN BELOW NORMAL WITH HIGHS FROM THE MID 60S NORTH TO
THE LOWER 70S SOUTH. SWIM RISK WILL AGAIN BE HIGH AS 3 TO 5 FOOT
WAVES ARE EXPECTED INTO MARQUETTE AND ALGER COUNTIES BY AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 PM EDT TUE AUG 12 2014
MAIN FCST CONCERNS IN THE MEDIUM/LONGER RANGE WL FOCUS ON EXPECTED
BLO NORMAL TEMPS FOR WED THRU THU...WHEN DRY CNDN HI PRES IS FCST TO
DOMINATE UNDER A CONFLUENT NNW FLOW ALF. FOCUS FOR FRI/SAT WL SHIFT
TO PCPN CHCS ASSOCIATED WITH THE INTERACTION BTWN RETURNING MSTR IN
THE LLVL SW FLOW ARND THE DEPARTING HI TO THE SE AND SHRTWVS
TRACKING THRU THE GREAT LKS WITHIN THE NW FLOW FARTHER ALF. ALTHOUGH
ABV NORMAL TEMPS MAY RETURN FOR FRI INTO SAT...NO SUMMER-LIKE WARMTH
IS EXPECTED DURING THE NEXT WEEK.
WED NGT/THU...HI PRES AND DRY AIRMASS WITH PWAT BTWN 0.25-0.50 INCH
/AS LITTLE AS ABOUT 25 PCT OF NORMAL/ WL PASS OVER UPR MI UNDER NNW
FLOW ALF TO THE W OF SLOW MOVING CLOSED LO NEAR THE ONTARIO/QUEBEC
BORDER. UNDER MOCLR SKIES...EXPECT THE LOWEST MIN TEMPS ON WED NGT
OVER THE INTERIOR W...WHERE WINDS WL BE LIGHTEST FOR A LONGER TIME
AND WHERE THE RDG AXIS IS FCST TO BE AT 12Z THU. NOT OUT OF THE
QUESTION THERE COULD BE SOME 30S AT THE COLDER LOCATIONS IN THIS
AREA. WITH H85 TEMPS FCST TO PEAK BTWN 8C OVER THE E AND 12C OVER
THE W AT 00Z FRI...EXPECT HI TEMPS TO REACH THE 70S OVER THE
INTERIOR W/SCENTRAL BUT HOLD IN THE 60S OVER MUCH OF THE E WITH A
STEADY NNW SFC-H925 FLOW OFF LK SUP.
THU NGT...SFC HI PRES IS FCST TO SINK OVER INDIANA BY 12Z FRI...
WITH SFC RDG AXIS EXTENDING N THRU ERN UPR MI. THE LOWEST TEMPS WL
BE OVER THE INTERIOR E...WHERE PWAT UNDER 0.5 INCH/MOCLR SKIES/
LIGHTER WINDS UNDER THE RDG AXIS WL LINGER THRU THE NGT. SOME CLDS
ASSOCIATED WITH PWAT RISING AOA 1 INCH AT IWD BY 12Z FRI IN SW
RETURN FLOW ARND THE SFC HI WL LIMIT THE DIURNAL TEMP FALL IN THAT
AREA.
FRI THRU SAT...UPR MI IS FCST TO REMAIN UNDER NW FLOW ALF BTWN DEEP
UPR TROF OVER QUEBEC AND RDG EXTENDING THRU THE PLAINS. THE
INTERACTION BTWN SHRTWVS DIGGING SEWD THRU THIS UPR FLOW AND MORE
MSTR ADVECTED INTO THE AREA IN LLVL WSW FLOW TO THE NW OF SFC HI
FCST TO SINK INTO THE SRN MID ATLANTIC STATES WL BE THE MAIN FCST
CONCERN DURING THIS PERIOD. A GOOD NUMBER OF THE MEDIUM RANGE MODELS
GENERATE PCPN AS EARLY AS FRI...WHEN THE HIER PWAT ARND 1.5 INCHES
IS FCST TO RETURN. CONSIDERING THE RATHER DRAMATIC INCRS IN PWAT/
SOME ISENTROPIC ASCENT...ADDED CHC POPS FOR THE FRI FCST DESPITE AN
ABSENCE OF SGNFT DEEP LYR QVECTOR CNVGC WELL SE OF STRONGER SHRTWV
SLIDING THRU NW ONTARIO. A BETTER CHC OF SHOWERS/A FEW TS WL ARRIVE
ON FRI NGT AND SAT...WHEN MODEL CONSENSUS IS TRENDING TOWARD THE
PASSAGE OF THE DIGGING ONTARIO SHRTWV/ATTENDANT SFC COLD FNT AND AN
AREA OF SHARPER DEEP LYR QVECTOR CNVGC. ALTHOUGH THE GREATER CLD
COVER WL TEND TO LIMIT THE DIURNAL DIURNAL VARIATION DURING THIS
TIME...EXPECT TEMPS TO RISE ABV NORMAL DURING THIS PERIOD AS THE WSW
FLOW BRINGS A RETURN OF H85 TEMPS AS HI AS 16-17C BY SAT.
SUN THRU TUE...MOST OF THE LONGER RANGE MODELS INDICATE SFC HI PRES
WL BLD INTO THE UPR LKS ON SUN FOLLOWING SHRTWV/COLD FROPA PASSAGE
BY LATE SAT...SO CONSENSUS FCST WL SHOW A DRYING TREND AND A RETURN
OF A BIT COOLER AIR. PCPN CHCS WL RETURN EARLY NEXT WEEK AS THE UPR
FLOW IS FCST TO BECOME MORE ZONAL AND ALLOW THE PASSAGE OF ANOTHER
SHRTWV.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1205 AM EDT WED AUG 13 2014
HIGH PRESSURE AND DRIER AIR MOVING INTO THE WESTERN U.P. WILL BRING
VFR CONDITIONS TO ALL SITES THROUGH THE FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 PM EDT TUE AUG 12 2014
NORTH WINDS GUSTING TO MORE THAN 25 KTS ACROSS THE EASTERN PART OF
THE LAKE WILL DIMINISH THIS EVENING AS THE PRES GRADIENT WEAKENS. A
REINFORCING COLD FRONT WILL PUSH ACROSS THE LAKE ON WEDNESDAY
ALLOWING NORTHWESTERLY WIND GUSTS OF UP TO 25 KTS WEDNESDAY
AFTERNOON. WINDS SHOULD DIMINISH BY LATE WEDNESDAY AND THEN REMAIN
BELOW 15 KTS INTO THE UPCOMING WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS BILLINGS MT
325 AM MDT WED AUG 13 2014
.SHORT TERM...VALID FOR TDY AND THU...
UPPER LEVEL RIDGE THAT HAS BEEN IN PLACE FOR THE LAST SEVERAL DAYS
WILL GIVE WAY TO A SHORTWAVE TROUGH...BRINGING WITH IT SOME
POTENTIAL FOR SENSIBLE WEATHER FOR SOUTHEASTERN MONTANA.
DURING THE OVERNIGHT HOURS...THE HRRR MODEL DID A FAIRLY GOOD JOB
OF DEPICTING CONVECTION IN WESTERN MONTANA. AFTER CLOSER LOOK AT
THE LAST FEW RUNS...DECIDED TO ADD A SLIGHT CHANCE OF AN ISOLATED
SHOWER IN THE CENTRAL ZONES...INCLUDING AREAS IN AND AROUND
BILLINGS AROUND 1800 UTC.
AMOUNT OF CLOUD COVER IS GOING TO BE AN ISSUE TODAY WITH RESPECT
TO HIGH TEMPS...AS THE TIMING OF THE ARRIVAL OF ADDITIONAL
MONSOONAL MOISTURE MAY KEEP THE SKIES CLOUDIER THAN INITIALLY
THOUGHT IN PREVIOUS FORECAST PERIODS...PRECLUDING THE FULL
POTENTIAL FOR MAXING OUT. AT 200 AM...IT WAS STILL 74 DEGREES AT
KBIL AND 72 AT KMLS. SO...KEPT WITH GOING FORECAST FOR THE MID 90S
FOR TODAY...ALTHOUGH COULD EASILY SEE KBIL OR KMLS APPROACH THE
CENTURY MARK IF THE CLOUDS CLEAR OUT.
IN PATTERNS LIKE THIS...ITS ALWAYS A GOOD IDEA TO KEEP A WATCH ON
THE POTENTIAL FOR FIRE STARTS DUE TO DRY THUNDERSTORMS. SPC
FIRE OUTLOOK PLACES CENTRAL MONTANA UNDER AN ISOLATED DRY
THUNDERSTORM RISK FOR WEDNESDAY...MAINLY DUE TO THE HOT AND DRY
NATURE OF THE PAST SEVERAL DAYS. WITH AN ISOLATED THREAT OF
THUNDERSTORMS...POTENTIAL LIGHTNING STRIKES COULD IGNITE SOME
STARTS...SIMILAR TO WHAT WAS SEEN ON TUESDAY. EITHER WAY IT BEARS
WATCHING.
THURSDAY SHOULD NOT BE QUITE AS WARM AS TUESDAY AND WEDNESDAY...AS
THE REGION CONTINUES TO BE UNDER GENERAL TROUGHINESS. BEST
DIVERGENCE PROGGED TO REMAIN TO THE NORTH AND WEST OF THE BYZ
CWA...BUT KEPT POP CHANCES FROM 40 TO 50 IN FAR WESTERN ZONES FOR
AN ISOLATED THUNDERSTORM TO FORM. NEITHER INSTABILITY OR SHEAR IS
THAT GREAT...SO ANY STORMS THAT FORM SHOULD NOT BE SEVERE IN
NATURE. SINGER
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
THE CHANCE OF SHOWERS AND THUNDERSTORMS CONTINUES TO LOOK ELEVATED
FRI AND SAT /ESPECIALLY IN SOUTHEASTERN MT/ AS THE UPPER-LEVEL LOW
CURRENTLY OVER THE PACIFIC NORTHWEST FILLS AND MIGRATES NORTHEAST.
THE 00 UTC GUIDANCE CONTINUES TO WAVER A BIT ON THE DETAILS OF THE
DEAMPLIFYING WAVE...BUT OFFERS ENOUGH AGREEMENT FOR US TO CONTINUE
ADVERTISING CHANCE-STYLE POPS EVERYWHERE FRI AND OVER SOUTHEASTERN
MT ON SAT. GIVEN THE TRENDS IN THE GFS AND ECMWF...IT APPEARS THAT
1/ A MONSOONAL MOISTURE PUSH THAT GETS PULLED NORTHWARD IN ADVANCE
OF THE UPPER-LEVEL LOW MAY ENHANCE PRECIPITATION OVER SOUTHEASTERN
MT ON FRI...AND 2/ SHEAR AND INSTABILITY COULD SUPPORT SOME SEVERE
THUNDERSTORM RISK IN SOUTHEASTERN MT ON SAT IF STORMS FIRE THERE.
BY LATER IN THE WEEKEND AND INTO NEXT WEEK...IT APPEARS THE LARGE-
SCALE FLOW FROM THE PACIFIC OCEAN INTO WESTERN NORTH AMERICA COULD
RESHUFFLE WITH A PERSISTENT 500-MB LOW ACROSS THE ALEUTIAN ISLANDS
PERHAPS GETTING REPLACED BY MEAN RIDGING. THE INTERIM EFFECT LOOKS
TO BE ZONAL FLOW ALOFT OVER THE LOCAL REGION WITH DIURNALLY-DRIVEN
LOW-END CONVECTIVE CHANCES AND SEASONABLY WARM TEMPERATURES DURING
THE SUN THROUGH TUE PERIOD...AT LEAST. HOWEVER...IF THE FULL-SCALE
RESHUFFLING TAKES PLACE AS THE 00 UTC GFS AND ECMWF SIMULATED...IT
IS VERY POSSIBLE THAT MEAN TROUGHING COULD BECOME ESTABLISHED OVER
THE NORTHERN ROCKIES OR NORTHERN PLAINS BY LATE NEXT WEEK AND THUS
LEAD TO COOLER AND POTENTIALLY WETTER CONDITIONS. THE JURY IS VERY
FAR FROM OUT ON THAT THOUGH AS PREDICTABILITY IS LOW REGARDING ANY
CHANGE LIKE THAT...MUCH LESS AT THIS TIME OF THE YEAR WHEN THERMAL
IMBALANCE AND DYNAMIC FORCING IN THE NORTHERN HEMISPHERE TYPICALLY
IS AT AN OVERALL MINIMUM. SCHULTZ
&&
.AVIATION...
ISOLATED TO WIDELY SCATTERED SHOWERS AND STORMS ARE EXPECTED TODAY
AND TONIGHT. LOCAL MVFR CONDITIONS...GUSTY WINDS AND SOME MOUNTAIN
OBSCURATIONS ARE POSSIBLE WITH THAT ACTIVITY...BUT THE PROBABILITY
OF IMPACT AT ANY ONE LOCATION IS NOT THAT HIGH. VFR CONDITIONS ARE
OTHERWISE EXPECTED OVER SOUTHERN MT AND NORTH CENTRAL WY. SCHULTZ
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 095 065/092 063/090 062/088 061/088 061/088 061/090
2/T 23/T 43/T 32/T 22/T 22/T 22/T
LVM 092 057/090 054/088 053/087 052/088 052/088 053/089
4/T 45/T 54/T 42/T 22/T 22/T 22/T
HDN 097 063/095 063/091 060/090 058/090 058/090 058/092
3/T 23/T 43/T 32/T 22/T 22/T 22/T
MLS 097 066/096 066/089 064/090 061/089 061/090 061/091
2/T 22/T 44/T 44/T 42/T 22/T 22/T
4BQ 097 064/094 064/088 063/089 060/089 059/090 059/090
3/T 22/T 44/T 43/T 32/T 22/T 22/T
BHK 094 062/093 061/087 059/087 056/086 056/087 055/087
2/T 22/T 34/T 44/T 42/T 22/T 22/T
SHR 094 059/089 058/089 057/089 054/088 054/088 054/089
3/T 33/T 43/T 32/T 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
330 AM EDT WED AUG 13 2014
.SYNOPSIS...
A COLD FRONT WILL SLOWLY PUSH OFFSHORE TODAY. HIGH PRESSURE WILL BUILD
INTO THE REGION THURSDAY. A WEAK FRONT WILL APPROACH THU NIGHT AND
LINGER ACROSS THE AREA FRIDAY. HIGH PRESSURE WILL SHIFT OFF THE
COAST SATURDAY AND REMAIN THERE WITH A TROUGH DEVELOPING INLAND
THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 330 AM WED...AN AREA OF CONVECTION EARLY THIS MORNING HAS
WEAKENED AS IT MOVED EAST TOWARDS THE EASTERN FA. TEMPORARY
SUBSIDENCE MAY BE LIMITING CONVECTION...ALONG WITH THE LACK OF A
TRIGGERING MECHANISM. NEVERTHELESS...THE ATMOSPHERE REMAINS
UNSTABLE WITH A WARM SW FLOW PER RAP SOUNDINGS AND KMHX VWP. HAVE
LEFT IN ISO MENTION OF THUNDER REST OF THE OVERNIGHT INTO WED AM.
POSITIVELY TILTED UPR TROUGH LOCATED ACROSS THE OHIO VALLEY THIS
MORNING PER H20 VAPOR IMAGERY WILL SWING THROUGH EASTERN NC THIS
AFTERNOON. THIS WILL PROVIDE DECENT UPR FORCING AND DEEP LAYER
SHEAR ACROSS THE EASTERN FA...AND SHOULD THERE BE ENOUGH MOISTURE
AVAILABILITY... COULD SPUR THUNDERSTORM DEVELOPMENT MAINLY EAST OF
HWY 17 THIS AFTERNOON. THE KEY FACTOR WILL BE MOISTURE
AVAILABILITY IN THE MID LEVELS...AS GFS/ECM KEEP THE AREA DRY.
NAM/SREF SOUNDINGS HOWEVER ARE MORE AGGRESSIVE WITH
INSTABILITY/MOISTURE...AND ON PAR WITH NSSL WRF IN CONVECTIVE
DEVELOPMENT NEAR THE COAST AFT 16Z. ANY BACKING OF WINDS AHEAD OF
SLOW MOVING COLD FRONT MOVING THROUGH WOULD ENHANCE THE SFC BASED
INSTABILITY AND WITH 30-35 KT OF SHEAR IN PLACE...COULD GENERATE
AN ISO STRONG/SEVERE THUNDERSTORM THREAT. DUE TO THE
UNCERTAINTY...WILL CAP POPS IN THE LOW CHANCE/SCT RANGE FAR EASTERN
AREAS...WITH NO POPS ACROSS THE COASTAL PLAIN COUNTIES.
&&
.SHORT TERM /TONIGHT/...
AS OF 330 AM WED...ANY PRECIP WILL QUICKLY WANE AND SHIFT OFFSHORE
BY EVENING AS DRY AIR IS USHERED IN BEHIND FRONTAL PASSAGE. SFC
DEWPOINTS WILL DROP TO THE LOWER/MIDDLE 60S AND COMBINED WITH
LIGHT/CALM WINDS AND CLEARING SKIES...ALLOW TEMPS TO DROP
COMFORTABLY INTO THE 60S AREA WIDE...WITH LOW 70S IMMEDIATE COAST.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 315 AM WED...WEAK SFC HIGH PRES BUILDS INTO THE REGION THURS
WITH CYCLONIC FLOW CONTINUING ALOFT WITH AN UPPER LOW SLOWLY
PUSHING EAST ACROSS QUEBEC. A VERY DRY AIRMASS WILL BE IN PLACE FOR
AUGUST WITH PWATS BELOW 1"...AROUND 2 SD BELOW NORMAL...AND EXPECT
DRY CONDITIONS TO PREVAIL WITH COMFORTABLE TEMPS IN THE 80S WITH
DEWPOINTS IN THE LOWER 60S.
A SHORTWAVE MOVES THROUGH THE FLOW ALOFT LATE IN THE WEEK WITH A
WEAK TROF/BACKDOOR FRONT MOVING INTO THE REGION FRI. PWATS INCREASE
TO AROUND 1-1.25" WITH SHORTWAVE ENERGY AND FRONTAL CONVERGENCE
PROVIDING SUPPORT FOR ISOL TSTMS THROUGH PEAK HEATING. THE TROF
LINGERS ACROSS THE AREA THROUGH SATURDAY BEFORE DISSIPATING WITH
THE PIEDMONT TROF DEVELOPING INLAND AND HIGH PRESSURE CENTERED WELL
OFFSHORE PRODUCING DEEP SOUTHERLY FLOW ACROSS THE AREA. EXPECT
ISOLATED...MAINLY DIURNALLY DRIVEN CONVECTION ALONG THE SEABREEZE OR
INLAND TROUGH TO PERSIST SAT AND SUN.
MODELS DIVERGE IN THE TIMING AND STRENGTH OF A SHORTWAVE MOVING
THROUGH THE UPPER TROUGH ACROSS THE EAST COAST SUN NIGHT INTO MON.
THE GFS IS FASTER/STRONGER BRINGING INCREASING SUPPORT FOR SHOWERS
AND THUNDERSTORMS ACROSS THE REGION EARLY NEXT WEEK...HOWEVER TREND
IS TO FAVOR THE SLOWER AND WEAKER SOLUTION OF THE ECENS. FOLLOWED
CLOSELY TO WPC GUIDANCE EARLY NEXT WEEK CONTINUING THE TYPICAL
DIURNALLY DRIVEN CONVECTION.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 330 AM WED...MAINLY VFR CONDITIONS THROUGH THE PERIOD. COULD
SEE SOME MVFR MAINLY DUE TO LOWERED VSBYS THROUGH SUNRISE THIS AM
AS WINDS REMAIN LIGHT AND LOW LEVEL MOISTURE IS ON THE HIGH SIDE.
ANY LIGHT FOG BURNS OFF AFTER SUNRISE WITH FEW OR SCT STRATO CU
THROUGH THE DAY. WINDS WILL BE GENERALLY W TO WNW TODAY BEHIND A
COLD FRONTAL PASSAGE. WINDS DROP TO CALM TONIGHT WITH CLEAR SKIES.
ONLY A SMALL CHANCE FOR LIGHT FOG TONIGHT AS DRY AIR FILTERS INTO
THE REGION.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM WED...VFR CONDITIONS EXPECTED TO DOMINATE THROUGH MUCH
OF THE LONG TERM. HIGH PRES BUILDS ACROSS THE AREA THURS BRINGING
DRY CONDITIONS...THEN WILL SEE MOISTURE GRADUALLY INCREASE THROUGH
THE REST OF THE LONG TERM WITH ISOL...MAINLY DIURNALLY DRIVEN...
CONVECTION EACH AFTERNOON ALONG THE INLAND TROUGH OR SEABREEZE.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 330 AM WED...WINDS ARE SW TO W EARLY THIS MORNING IN THE
10-15 KT RANGE...THOUGH GUSTING AT TIMES TO 20 KT. SEAS RANGE FROM
2 TO 4 FT. THE W TO SW FLOW WILL CONTINUE IN THIS RANGE THROUGH
THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. COULD SEE SOME
SEAS TOPPING OUT AT 5 FT ACROSS SOUTHERN/CENTRAL WATERS TODAY. THE
WINDS TURN NW TO EVENTUALLY NORTH LATE TONIGHT BEHIND THE COLD
FRONT...THOUGH WILL GENERALLY REMAIN IN THE 10-15 KT RANGE.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM WED...LIGHT AND VARIABLE WINDS THURS WITH HIGH PRES
ACROSS THE AREA WHILE SEAS SUBSIDING THROUGH THE DAY. THE HIGH
SLIDES OFFSHORE DURING THE LATTER HALF OF THE WEEK WITH WINDS
VEERING TO SLY MAINLY 10 KT OR LESS AND SEAS GENERALLY 1 TO 3 FT.
WINDS MAY BECOME VARIABLE NORTHERN WATERS FRI WITH A BACKDOOR FRONT
POTENTIALLY MOVING INTO THE AREA FOR A BRIEF PERIOD...STILL SOME
DIFFERENCES AMONG THE MODELS JUST HOW FAR THE FRONT WILL PUSH INTO
THE REGION. WINDS RETURN TO SOUTHERLY BY FRIDAY NIGHT AND REMAIN
LIGHT...MAINLY BELOW 15 KT INTO SAT NIGHT. DISCOUNTING THE GFS AND
SUBSEQUENTLY WAVEWATCH III SAT NIGHT AND SUN AS IT IS ANOMALOUSLY
FAST AND STRONG BRINGING A ROBUST SHORTWAVE TROUGH AND ATTENDANT LOW
PRES SYSTEM ACROSS THE MID ATLANTIC...SUBSEQUENTLY BRINGING SW WINDS
TO 20-25 KT AND SEAS AS HIGH AS 5-8 FT ACROSS THE EASTERN NC WATERS
ON SUN. INSTEAD USED A BLEND OF THE ECMWF AND WPC GUIDANCE BRINGING
SW WINDS AROUND 10-15 KT AND KEEPING SEAS AROUND 2-4 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TL
NEAR TERM...TL
SHORT TERM...TL
LONG TERM...SK
AVIATION...SK/TL
MARINE...SK/TL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
434 AM EDT WED AUG 13 2014
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST AND WELL AWAY FROM THE
AREA TODAY. A TROUGH EXTENDING SOUTHWEST FROM THE LOW WILL MOVE
SOUTHEAST OF THE REGION TODAY AS YET ANOTHER TROUGH SWINGS THROUGH
THIS EVENING. MUCH COOLER TEMPERATURES WILL PREVAIL TODAY THROUGH
FRIDAY MORNING. HIGH PRESSURE WILL GRADUALLY BUILD SOUTHEAST ACROSS
THE OHIO VALLEY BY FRIDAY MORNING AND TO THE EAST COAST BY SATURDAY
MORNING. A WARM UP IS IN STORE FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LINE OF SHOWERS CONTINUES TO BREAK UP ALONG THE LAKE SHORE AS IT
MOVES INLAND FROM JUST SOUTH OF CUYAHOGA COUNTY NORTHEAST TO ERIE
AND CRAWFORD COUNTIES IN PENNSYLVANIA. THIS ACTIVITY IS IN
ASSOCIATION WITH THE FIRST OF TWO TROUGHS MOVING THROUGH THE REGION.
LATEST HRRR MODEL SHOWS PRECIPITATION GRADUALLY ENDING THROUGH THE
DAY AND THEN DRYING OUT LATER THIS EVENING OVER THE EASTERN PORTIONS
OF THE FORECAST AREA. WITH UPPER LEVEL LOW IN PLACE...CANT RULE OUT
CHANCE FOR A SHOWER OR TWO...ESPECIALLY THIS MORNING.
TEMPERATURES WILL BE COOLER TODAY ACROSS THE FORECAST AREA. WITH
CLOUDS AND POSSIBLE SHOWERS PRESENT IN THE EAST...HIGHS MAY NOT GET
OUT OF THE 60S. WE SHOULD START TO RETURN BACK TO SOME SUNSHINE
TODAY IN THE WEST AND THIS WILL ALLOW FOR SOME HEATING TO TAKE PLACE
AND RECOVER TEMPERATURES BACK TO THE 70S FOR HIGHS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
UPPER LEVEL PATTERN DESCRIPTION OF THE DAY...UGLY. HOW ELSE CAN ONE
DESCRIBE THE APPEARANCE OF A MEGA UPPER LEVEL LOW PRESSURE SYSTEM
THAT WILL DOMINATE THE EASTERN UNITED STATES OVER THE NEXT 24 TO 36
HOURS. DEEP UPPER LEVEL LOW WILL KEEP LOW PRESSURE AT THE SURFACE
PRESENT THROUGH TONIGHT. THIS WILL KEEP THE CYCLONIC FLOW AND A
RETURN OF A SECONDARY TROUGH INTO THE AREA TODAY. THE LOW WILL PULL
OUT TO THE NORTHEAST AND ALLOW SURFACE HIGH PRESSURE TO BUILD
SOUTHEAST INTO THE OHIO VALLEY REGION. THE COMBINATION OF THE
CYCLONIC FLOW FROM THE NORTHWEST AND THE HIGH TO THE WEST WILL KEEP
COLD AIR ADVECTION GOING THROUGH FRIDAY AT LEAST. SOME RECOVERY WILL
BEGIN TO TAKE PLACE ON SATURDAY AS THE SURFACE HIGH SHIFTS TO THE
EAST COAST ALLOWING FOR SOME RETURN SOUTHWESTERLY FLOW.
EVENTUALLY...ANOTHER SHOT OF MOISTURE COULD STREAM INTO THE AREA
SATURDAY INTO SATURDAY NIGHT AND BRING ANOTHER CHANCE FOR SOME
SHOWERS. THE MOISTURE IS IN RESPONSE TO A FAST MOVING UPPER LEVEL
TROUGH AND SURFACE LOW PRESSURE SYSTEM. FURTHER WARMING WILL TAKE
PLACE SATURDAY AND SATURDAY NIGHT IN THE WARM AIR ADVECTION.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
THE PERSISTENT TROUGH OVER THE GREAT LAKES IS PROGGED TO FLATTEN
OUT EARLY NEXT WEEK AS THE UPPER LOW OVER THE NORTHEAST SLOWLY LIFTS
OUT. MOST OF THE MODELS BRING ONE LAST SHORT WAVE ACROSS THE GREAT
LAKES EARLY SUNDAY AND WILL KEEP SHOWERS IN THE FORECAST FOR SUNDAY.
THE TIMING IS UNCERTAIN THOUGH AND THE SYSTEM COULD BE THROUGH EARLY
ON SUNDAY AND THE DAY MAY BE SALVAGEABLE.
MOST OF THE MODELS AND ENSEMBLES BUILD THE SURFACE HIGH ACROSS THE
LOWER GREAT LAKES BY MONDAY. THE OPERATIONAL ECWMF IS THE HOLD
OUT...KEEPING THE SURFACE FRONT NEARBY. WILL GO WITH THE CONSENSUS
AND TRY TO DRY THINGS OUT ON MONDAY. THE FRONT MAY TRY TO COME BACK
AS A WARM FRONT BY TUESDAY AND WILL BRING THE SHOWERS BACK INTO THE
FORECAST TUESDAY AND ESPECIALLY TUESDAY NIGHT.
LOWERED THE FORECAST TEMPERATURES BACK DOWN TO NORMAL OR A COUPLE OF
DEGREES BELOW NORMAL FOR SUNDAY AND MONDAY. STARTED TRENDING TEMPS
BACK UP A FEW DEGREES ON TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
THE TROUGH AND SHOWERS WILL MOVE SOUTHEAST OF THE AREA THIS
MORNING. AREAS OF IFR CEILINGS WILL CONTINUE THROUGH MID MORNING AS
THE BOUNDARY LAYER IS VERY MOIST. THE LOW CEILINGS WILL GRADUALLY
RISE TODAY WITH DAY TIME HEATING TO VFR CEILINGS 040-050 THIS
AFTERNOON. SKIES SHOULD CLEAR THIS EVENING EXCEPT FOR EXTREME
NORTHEAST OH AND NORTHWEST PA. THE WEST NORTHWEST WIND WILL BE A
BIT GUSTY THIS AFTERNOON.
OUTLOOK...NON VFR POSSIBLE IN SHOWERS/THUNDERSTORMS SATURDAY
EVENING INTO SUNDAY.
&&
.MARINE...
THE FORECAST IS TRICKY WITH REGARD TO THE SMALL CRAFT ADVISORY.
NORTHWEST WINDS HAVE PICKED UP ON THE LAKE AND THE SMALL CRAFT
ADVISORY WILL BE NEEDED INTO THE AFTERNOON. THERE WILL LIKELY BE A
DIMINISHING OF THE WINDS...ESPECIALLY ON THE WEST HALF OF THE LAKE
THIS AFTERNOON AND EVENING. IT WILL TAKE A WHILE FOR THE LAKE TO
SETTLE DOWN...THEN THE NEXT TROUGH IS DUE TONIGHT AND WINDS WILL
PICK BACK UP FROM THE NORTHWEST AND NORTH. WOULD RATHER NOT TAKE
DOWN THE SMALL CRAFT ADVISORY FOR A FEW HOURS LATE THIS AFTERNOON
AND EARLY THIS EVENING ON THE WEST HALF OF THE LAKE JUST TO REISSUE
IT AGAIN THIS EVENING SO WILL JUST KEEP IT GOING. WATERSPOUTS ARE
POSSIBLE ESPECIALLY TONIGHT (WED NIGHT) INTO THURSDAY MORNING AS THE
COLDEST AIR ALOFT PASSES OVER THE LAKE.
WINDS WILL VEER MORE FROM THE SOUTHWEST ON FRIDAY AHEAD OF THE NEXT
WEAK FRONT. NOT VERY CONFIDENT ON HOW STRONG THE SOUTHWEST WINDS MAY
GET BUT IT MAY REMAIN BRISK AND CHOPPY ON THE EAST HALF OF THE LAKE
GOING INTO THE WEEKEND.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THURSDAY FOR LEZ145>149.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THURSDAY FOR LEZ142>144.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KOSARIK
AVIATION...KOSARIK
MARINE...KOSARIK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
337 AM EDT WED AUG 13 2014
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO MOVE NORTHEAST AND WELL AWAY FROM THE
AREA TODAY. A TROUGH EXTENDING SOUTHWEST FROM THE LOW WILL MOVE
SOUTHEAST OF THE REGION TODAY AS YET ANOTHER TROUGH SWINGS THROUGH
THIS EVENING. MUCH COOLER TEMPERATURES WILL PREVAIL TODAY THROUGH
FRIDAY MORNING. HIGH PRESSURE WILL GRADUALLY BUILD SOUTHEAST ACROSS
THE OHIO VALLEY BY FRIDAY MORNING AND TO THE EAST COAST BY SATURDAY
MORNING. A WARM UP IS IN STORE FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LINE OF SHOWERS CONTINUES TO BREAK UP ALONG THE LAKE SHORE AS IT
MOVES INLAND FROM JUST SOUTH OF CUYAHOGA COUNTY NORTHEAST TO ERIE
AND CRAWFORD COUNTIES IN PENNSYLVANIA. THIS ACTIVITY IS IN
ASSOCIATION WITH THE FIRST OF TWO TROUGHS MOVING THROUGH THE REGION.
LATEST HRRR MODEL SHOWS PRECIPITATION GRADUALLY ENDING THROUGH THE
DAY AND THEN DRYING OUT LATER THIS EVENING OVER THE EASTERN PORTIONS
OF THE FORECAST AREA. WITH UPPER LEVEL LOW IN PLACE...CANT RULE OUT
CHANCE FOR A SHOWER OR TWO...ESPECIALLY THIS MORNING.
TEMPERATURES WILL BE COOLER TODAY ACROSS THE FORECAST AREA. WITH
CLOUDS AND POSSIBLE SHOWERS PRESENT IN THE EAST...HIGHS MAY NOT GET
OUT OF THE 60S. WE SHOULD START TO RETURN BACK TO SOME SUNSHINE
TODAY IN THE WEST AND THIS WILL ALLOW FOR SOME HEATING TO TAKE PLACE
AND RECOVER TEMPERATURES BACK TO THE 70S FOR HIGHS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
UPPER LEVEL PATTERN DESCRIPTION OF THE DAY...UGLY. HOW ELSE CAN ONE
DESCRIBE THE APPEARANCE OF A MEGA UPPER LEVEL LOW PRESSURE SYSTEM
THAT WILL DOMINATE THE EASTERN UNITED STATES OVER THE NEXT 24 TO 36
HOURS. DEEP UPPER LEVEL LOW WILL KEEP LOW PRESSURE AT THE SURFACE
PRESENT THROUGH TONIGHT. THIS WILL KEEP THE CYCLONIC FLOW AND A
RETURN OF A SECONDARY TROUGH INTO THE AREA TODAY. THE LOW WILL PULL
OUT TO THE NORTHEAST AND ALLOW SURFACE HIGH PRESSURE TO BUILD
SOUTHEAST INTO THE OHIO VALLEY REGION. THE COMBINATION OF THE
CYCLONIC FLOW FROM THE NORTHWEST AND THE HIGH TO THE WEST WILL KEEP
COLD AIR ADVECTION GOING THROUGH FRIDAY AT LEAST. SOME RECOVERY WILL
BEGIN TO TAKE PLACE ON SATURDAY AS THE SURFACE HIGH SHIFTS TO THE
EAST COAST ALLOWING FOR SOME RETURN SOUTHWESTERLY FLOW.
EVENTUALLY...ANOTHER SHOT OF MOISTURE COULD STREAM INTO THE AREA
SATURDAY INTO SATURDAY NIGHT AND BRING ANOTHER CHANCE FOR SOME
SHOWERS. THE MOISTURE IS IN RESPONSE TO A FAST MOVING UPPER LEVEL
TROUGH AND SURFACE LOW PRESSURE SYSTEM. FURTHER WARMING WILL TAKE
PLACE SATURDAY AND SATURDAY NIGHT IN THE WARM AIR ADVECTION.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
THE PERSISTENT TROUGH OVER THE GREAT LAKES IS PROGGED TO FLATTEN
OUT EARLY NEXT WEEK AS THE UPPER LOW OVER THE NORTHEAST SLOWLY LIFTS
OUT. MOST OF THE MODELS BRING ONE LAST SHORT WAVE ACROSS THE GREAT
LAKES EARLY SUNDAY AND WILL KEEP SHOWERS IN THE FORECAST FOR SUNDAY.
THE TIMING IS UNCERTAIN THOUGH AND THE SYSTEM COULD BE THROUGH EARLY
ON SUNDAY AND THE DAY MAY BE SALVAGEABLE.
MOST OF THE MODELS AND ENSEMBLES BUILD THE SURFACE HIGH ACROSS THE
LOWER GREAT LAKES BY MONDAY. THE OPERATIONAL ECWMF IS THE HOLD
OUT...KEEPING THE SURFACE FRONT NEARBY. WILL GO WITH THE CONSENSUS
AND TRY TO DRY THINGS OUT ON MONDAY. THE FRONT MAY TRY TO COME BACK
AS A WARM FRONT BY TUESDAY AND WILL BRING THE SHOWERS BACK INTO THE
FORECAST TUESDAY AND ESPECIALLY TUESDAY NIGHT.
LOWERED THE FORECAST TEMPERATURES BACK DOWN TO NORMAL OR A COUPLE OF
DEGREES BELOW NORMAL FOR SUNDAY AND MONDAY. STARTED TRENDING TEMPS
BACK UP A FEW DEGREES ON TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
THE TROUGH AND SHOWERS WILL MOVE SOUTHEAST OF THE AREA THIS
MORNING. AREAS OF IFR CEILINGS WILL CONTINUE THROUGH MID MORNING AS
THE BOUNDARY LAYER IS VERY MOIST. THE LOW CEILINGS WILL GRADUALLY
RISE TODAY WITH DAY TIME HEATING TO VFR CEILINGS 040-050 THIS
AFTERNOON. SKIES SHOULD CLEAR THIS EVENING EXCEPT FOR EXTREME
NORTHEAST OH AND NORTHWEST PA. THE WEST NORTHWEST WIND WILL BE A
BIT GUSTY THIS AFTERNOON.
OUTLOOK...NON VFR POSSIBLE IN SHOWERS/THUNDERSTORMS SATURDAY
EVENING INTO SUNDAY.
&&
.MARINE...
THE FORECAST IS TRICKY WITH REGARD TO THE SMALL CRAFT ADVISORY.
NORTHWEST WINDS HAVE PICKED UP ON THE LAKE AND THE SMALL CRAFT
ADVISORY WILL BE NEEDED INTO THE AFTERNOON. THERE WILL LIKELY BE A
DIMINISHING OF THE WINDS...ESPECIALLY ON THE WEST HALF OF THE LAKE
THIS AFTERNOON AND EVENING. IT WILL TAKE A WHILE FOR THE LAKE TO
SETTLE DOWN...THEN THE NEXT TROUGH IS DUE TONIGHT AND WINDS WILL
PICK BACK UP FROM THE NORTHWEST AND NORTH. WOULD RATHER NOT TAKE
DOWN THE SMALL CRAFT ADVISORY FOR A FEW HOURS LATE THIS AFTERNOON
AND EARLY THIS EVENING ON THE WEST HALF OF THE LAKE JUST TO REISSUE
IT AGAIN THIS EVENING SO WILL JUST KEEP IT GOING. WATERSPOUTS ARE
POSSIBLE ESPECIALLY TONIGHT (WED NIGHT) INTO THURSDAY MORNING AS THE
COLDEST AIR ALOFT PASSES OVER THE LAKE.
WINDS WILL VEER MORE FROM THE SOUTHWEST ON FRIDAY AHEAD OF THE NEXT
WEAK FRONT. NOT VERY CONFIDENT ON HOW STRONG THE SOUTHWEST WINDS MAY
GET BUT IT MAY REMAIN BRISK AND CHOPPY ON THE EAST HALF OF THE LAKE
GOING INTO THE WEEKEND.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
LEZ142>149.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KOSARIK
AVIATION...KOSARIK
MARINE...KOSARIK
FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 156 AM CDT WED AUG 13 2014
RELATIVELY QUIET PERIOD. MAIN CONCERN IS WEAK BACK DOOR COLD FRONT
THAT WILL SLIDE ACROSS AREA DURING FIRST PART OF DAY. 13/00Z
NAM/GFS/ECMWF AND 13/03Z HRRR ALL INDICATE PRECIP WILL FORM SOUTH
OF FORECAST AREA THIS AFTERNOON ASSOC WITH BETTER INSTABILITY. AT
THAT POINT FRONT WILL BE ALONG OR SOUTH OF SOUTHERN BORDER OF FORECAST
AREA. NE WINDS MAY PICK UP FOR A BRIEF TIME BEHIND FRONT LATE
AFTERNOON INTO EARLY EVENING...THEN SFC HIGH PRESSURE MOVES SOUTH FROM
HUDSON BAY PROVIDING COOL NIGHT AND MILD THURSDAY. TEMPS TONIGHT
WILL PROBABLY TOUCH THE 30S IN FAR NORTHERN BOGS.
TEMP AND WIND FORECAST A BLEND OF PREVIOUS FORECAST WITH BEST
PERFORMING MODEL GUIDANCE.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 156 AM CDT WED AUG 13 2014
NORTHWEST FLOW ALOFT DUE TO UPPER LOW ACROSS EASTERN CANADA WILL
BECOME MORE ZONAL BY THE WEEKEND. UPPER PATTERN SUCH THAT MODELS
ARE HAVING A HARD TIME WITH FEATURES AND WHEN AND WHERE BEST
CHANCES OF RAIN WOULD OCCUR. TEMPERATURES DURING THE PERIOD SHOULD
BE AT OR SLIGHTLY ABOVE NORMAL FOR MID AUGUST.
MODELS CONTINUE TO DIFFER IF PRECIPITATION WOULD BREAK OUT ON THE
BACKSIDE OF THE HIGH DUE TO 850MB WARM ADVECTION. LEANING TOWARD
SHOWERS AND STORMS BREAKING OUT WEST OF THE AREA THURSDAY NIGHT...
THUS LEFT THIS PERIOD DRY. WILL CONTINUE THE CHANCES FOR SHOWERS
AND STORMS FRIDAY AS BOUNDARY PUSHES NORTH. A CONTINUED CHANCE FOR
SHOWERS AND STORMS WILL CONTINUE FRIDAY NIGHT AND SATURDAY. UPPER
FLOW STILL NORTHWEST AT THIS POINT...THUS EXPECT BOUNDARY TO PUSH
SOUTH OF THE AREA SATURDAY NIGHT AND SUNDAY. HAVE REMOVED RAIN
CHANCES ACROSS THE NORTH SATURDAY NIGHT AND SUNDAY AS HIGH PRESSURE
BUILDS INTO THE AREA. ALMOST TEMPTED TO REMOVE RAIN CHANCES ACROSS
THE SOUTH...BUT CONFIDENCE WAS LOWER IN CASE BOUNDARY SHOULD LINGER
ACROSS THE AREA. BEYOND SUNDAY...LOW CONFIDENCE IN THE DETAILS OF
ANY WEATHER MAKER AND WHEN THE BEST CHANCES FOR SHOWERS AND STORMS
COULD OCCUR. DID NOT MAKE ANY SIGNIFICANT CHANGES BEYOND SUNDAY.
ONLY ADJUSTMENTS TO MAX/MIN TEMPERATURE GRIDS WAS TO ADD A DEGREE
OR TWO AT NIGHT AT THE TYPICALLY WARMER LOCATIONS...AND DROPPED A
DEGREE OR TWO IN THE TYPICAL COOLER SPOTS AT NIGHT.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 156 AM CDT TUE AUG 12 2014
VFR CONDITIONS EXPECTED ACROSS FORECAST AREA THROUGH LATE EVENING.
WINDS WILL SWITCH TO NORTHEAST LATER THIS AFTERNOON BEHIND BACK
DOOR COLD FRONT. GUSTS NEAR 20 KTS POSSIBLE ALONG LAKE MICHIGAN
FOR A TIME LATE THIS AFTERNOON AND EARLY EVENING.
PATCHY GROUND FOG EXPECTED BETWEEN 08Z-12Z THURSDAY AM.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....JKL
LONG TERM......ECKBERG
AVIATION.......JKL
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
526 AM PDT WED AUG 13 2014
.UPDATE...
WE JUST SENT A QUICK UPDATE TO THE FORECAST TO ACCOUNT FOR MORE
WIDESPREAD COVERAGE OF THE MARINE STRATUS DECKS...PUSHING INTO THE
INLAND EMPIRE ATTM. HAVE ALSO INCREASED COVERAGE FOR TONIGHT AND
THURSDAY MORNING AS WE EXPECT A VERY SIMILAR PATTERN. NO OTHER
CHANGES AT THIS TIME.
.SYNOPSIS...
A MOIST AND UNSTABLE ATMOSPHERE WILL PERSIST TODAY ALONG WITH
AFTERNOON SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE FOR THE
MOUNTAINS AND DESERTS. SOUTHWEST FLOW ALOFT SHOULD BRING DRY
WEATHER TO THE REGION THURSDAY THROUGH EARLY NEXT WEEK.
TEMPERATURES WILL BE MOSTLY NEAR SEASONAL NORMALS THROUGH EARLY
NEXT WEEK...AND NIGHT AND MORNING LOW CLOUDS WILL CONTINUE ALONG
THE COAST AND THE NEARBY VALLEYS.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
NOCTURNAL CONVECTION HAS PERSISTED OVERNIGHT ACROSS SOUTHEAST
CALIFORNIA AND OVER THE LAST COUPLE HOURS HAS BLOSSOMED SOUTHWEST
INTO THE EASTERN PORTIONS OF SAN DIEGO AND RIVERSIDE
COUNTIES...WHERE A MOIST ATMOSPHERE RESIDES AND CONSIDERABLE
INSTABILITY. THIS ACTIVITY WILL DIMINISH TOWARDS DAYBREAK AS THE
UPPER LOW QUICKLY SHIFTS NORTH.
THE LATEST HIGH RESOLUTION MODELS THEN SUGGEST DIURNALLY DRIVEN
CONVECTION WILL FIRE UP LATER THIS AFTERNOON WITH THE HRRR MODEL
INDICATING A POCKET OF CAPE VALUES APPROACHING 4000 J/KG OVER
EASTERN SAN DIEGO COUNTY. MODEL SOUNDINGS INDICATE PWAT VALUES
PERSISTING OR INCREASING SLIGHTLY TO NEARLY 2.0 INCHES IN THIS
REGION. FORCING WILL BE WEAK TO NON- EXISTENT AS THE SYNOPTIC
SCALE TROUGH EXITS TO NORTHERN ARIZONA...HOWEVER RESIDUAL OUTFLOW
BOUNDARIES AND TERRAIN FEATURES WILL HELP TO KICK THE CONVECTION
OFF AGAIN THIS AFTERNOON. WITH EXCESSIVE DEEP MOISTURE PERSISTING
HAVE ISSUED A FLASH FLOOD WATCH FOR THE EASTERN MOUNTAINS AND
DESERTS AND THE COACHELLA VALLEY WHERE ANY STRONGER...SLOW MOVING
THUNDERSTORMS COULD DROP HEAVY RAINFALL OF ONE INCH PER HOUR OR
HIGHER THIS AFTERNOON. THE THREAT FOR FLASH FLOODING WILL QUICKLY
DIMINISH AFTER 5 PM. BROAD SW FLOW ENSUES TONIGHT WHICH SHOULD
SHUNT THE MOISTURE AWAY FROM OUR REGION...WITH POPS DWINDLING.
BROAD UPPER LEVEL HIGH PRESSURE CENTERED OVER ARIZONA WILL BE THE
MAIN SYNOPTIC WEATHER FEATURE FROM FRIDAY THROUGH EARLY NEXT WEEK.
THIS WILL ALLOW A STRONGER MARINE LAYER TO DEVELOP AND BRING
A STRONG DIURNAL SPREAD OF LOW CLOUDS INTO THE COASTAL VALLEYS
AND INTO THE WESTERN INLAND EMPIRE. THE BROAD HIGH PRESSURE IS NOT
EXPECTED TO BE PARTICULARLY STRONG...SO INLAND TEMPERATURES WILL
NOT EXCEED NORMAL VALUES.
&&
.AVIATION...
130930Z...SCATTERED THUNDERSTORMS IN LOWER DESERTS AND DESERT SLOPES
OF MOUNTAINS THROUGH AROUND 12Z...TAPERING OFF AFTER SUNRISE. BASES
AROUND 5000-7000 FEET MSL UNDER THESE STORMS WITH TOPS TO 25000
FEET. GUSTY ERRATIC WINDS AND BRIEFLY REDUCED VIS IN RAINFALL IN AND
AROUND TSTORMS. LOW CLOUDS WILL CONTINUE MOVING INLAND THIS MORNING
APPROACHING KONT BY SUNRISE. BASES WILL BE AROUND 1500 FEET MSL WITH
TOPS TO 2500 FEET. LOCAL VIS 3-5SM ALONG INLAND EXTENT OF CLOUDS.
SCATTER OUT WILL BE AROUND 17-18Z. SOME TSTORMS THIS AFTERNOON IN
MOUNTAINS AND DESERTS. TSTORMS IN CB CLOUD BASES AROUND 8000 FEET
MSL WITH TOPS UP TO 35000 FEET. THEN MOSTLY CLEAR AFTER 01Z THIS
EVE. LOW CLOUDS WILL RETURN TO COASTAL AIRPORTS BETWEEN 00-04Z AND
MAY REACH KONT BY 11Z THURSDAY. BASES WILL BE AROUND 1500 FEET MSL.
&&
.MARINE...
200 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH SUNDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR THE COACHELLA
VALLEY...RIVERSIDE COUNTY MOUNTAINS...SAN DIEGO COUNTY
DESERTS...SAN DIEGO COUNTY MOUNTAINS.
PZ...NONE.
&&
$$
PUBLIC...BROTHERTON
AVIATION/MARINE...MM
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
340 AM PDT WED AUG 13 2014
.SYNOPSIS...
A MOIST AND UNSTABLE ATMOSPHERE WILL PERSIST TODAY ALONG WITH
AFTERNOON SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE FOR THE
MOUNTAINS AND DESERTS. SOUTHWEST FLOW ALOFT SHOULD BRING DRY
WEATHER TO THE REGION THURSDAY THROUGH EARLY NEXT WEEK.
TEMPERATURES WILL BE MOSTLY NEAR SEASONAL NORMALS THROUGH EARLY
NEXT WEEK...AND NIGHT AND MORNING LOW CLOUDS WILL CONTINUE ALONG
THE COAST AND THE NEARBY VALLEYS.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
NOCTURNAL CONVECTION HAS PERSISTED OVERNIGHT ACROSS SOUTHEAST
CALIFORNIA AND OVER THE LAST COUPLE HOURS HAS BLOSSOMED SOUTHWEST
INTO THE EASTERN PORTIONS OF SAN DIEGO AND RIVERSIDE
COUNTIES...WHERE A MOIST ATMOSPHERE RESIDES AND CONSIDERABLE
INSTABILITY. THIS ACTIVITY WILL DIMINISH TOWARDS DAYBREAK AS THE
UPPER LOW QUICKLY SHIFTS NORTH.
THE LATEST HIGH RESOLUTION MODELS THEN SUGGEST DIURNALLY DRIVEN
CONVECTION WILL FIRE UP LATER THIS AFTERNOON WITH THE HRRR MODEL
INDICATING A POCKET OF CAPE VALUES APPROACHING 4000 J/KG OVER
EASTERN SAN DIEGO COUNTY. MODEL SOUNDINGS INDICATE PWAT VALUES
PERSISTING OR INCREASING SLIGHTLY TO NEARLY 2.0 INCHES IN THIS
REGION. FORCING WILL BE WEAK TO NON- EXISTENT AS THE SYNOPTIC
SCALE TROUGH EXITS TO NORTHERN ARIZONA...HOWEVER RESIDUAL OUTFLOW
BOUNDARIES AND TERRAIN FEATURES WILL HELP TO KICK THE CONVECTION
OFF AGAIN THIS AFTERNOON. WITH EXCESSIVE DEEP MOISTURE PERSISTING
HAVE ISSUED A FLASH FLOOD WATCH FOR THE EASTERN MOUNTAINS AND
DESERTS AND THE COACHELLA VALLEY WHERE ANY STRONGER...SLOW MOVING
THUNDERSTORMS COULD DROP HEAVY RAINFALL OF ONE INCH PER HOUR OR
HIGHER THIS AFTERNOON. THE THREAT FOR FLASH FLOODING WILL QUICKLY
DIMINISH AFTER 5 PM. BROAD SW FLOW ENSUES TONIGHT WHICH SHOULD
SHUNT THE MOISTURE AWAY FROM OUR REGION...WITH POPS DWINDLING.
BROAD UPPER LEVEL HIGH PRESSURE CENTERED OVER ARIZONA WILL BE THE
MAIN SYNOPTIC WEATHER FEATURE FROM FRIDAY THROUGH EARLY NEXT WEEK.
THIS WILL ALLOW A STRONGER MARINE LAYER TO DEVELOP AND BRING
A STRONG DIURNAL SPREAD OF LOW CLOUDS INTO THE COASTAL VALLEYS
AND INTO THE WESTERN INLAND EMPIRE. THE BROAD HIGH PRESSURE IS NOT
EXPECTED TO BE PARTICULARLY STRONG...SO INLAND TEMPERATURES WILL
NOT EXCEED NORMAL VALUES.
&&
.AVIATION...
130930Z...SCATTERED THUNDERSTORMS IN LOWER DESERTS AND DESERT SLOPES
OF MOUNTAINS THROUGH AROUND 12Z...TAPERING OFF AFTER SUNRISE. BASES
AROUND 5000-7000 FEET MSL UNDER THESE STORMS WITH TOPS TO 25000
FEET. GUSTY ERRATIC WINDS AND BRIEFLY REDUCED VIS IN RAINFALL IN AND
AROUND TSTORMS. LOW CLOUDS WILL CONTINUE MOVING INLAND THIS MORNING
APPROACHING KONT BY SUNRISE. BASES WILL BE AROUND 1500 FEET MSL WITH
TOPS TO 2500 FEET. LOCAL VIS 3-5SM ALONG INLAND EXTENT OF CLOUDS.
SCATTER OUT WILL BE AROUND 17-18Z. SOME TSTORMS THIS AFTERNOON IN
MOUNTAINS AND DESERTS. TSTORMS IN CB CLOUD BASES AROUND 8000 FEET
MSL WITH TOPS UP TO 35000 FEET. THEN MOSTLY CLEAR AFTER 01Z THIS
EVE. LOW CLOUDS WILL RETURN TO COASTAL AIRPORTS BETWEEN 00-04Z AND
MAY REACH KONT BY 11Z THURSDAY. BASES WILL BE AROUND 1500 FEET MSL.
&&
.MARINE...
200 AM...NO HAZARDOUS MARINE WEATHER IS EXPECTED THROUGH SUNDAY.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR THE COACHELLA
VALLEY...RIVERSIDE COUNTY MOUNTAINS...SAN DIEGO COUNTY
DESERTS...SAN DIEGO COUNTY MOUNTAINS.
PZ...NONE.
&&
$$
PUBLIC...BROTHERTON
AVIATION/MARINE...MM
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1025 AM EDT WED AUG 13 2014
.DISCUSSION...
CURRENT-THIS AFTERNOON...THE MORNING SOUNDINGS FROM TAMPA AND CAPE
CANAVERAL INDICATED PRECIPITABLE WATER VALUES AT 1.87 INCHES AND
1.66 INCHES RESPECTIVELY. LOOK OUTSIDE SHOWED CUMULUS JUST STARTING
TO FORM IN THE MOIST SOUTHWEST FLOW. THE 915MHZ VERTICAL WIND
PROFILER(S) AT KENNEDY SPACE CENTER WERE DETECTING SOUTHWEST WINDS
10 TO 15 MPH FROM JUST OFF THE SURFACE/FIRST SAMPLING POINT TO
APPROX. 10000 FEET. RUC UPPER AIR/500MB CHART SHOWED TROUGHING
EXTENDING FROM THE GREAT LAKES TO THE NORTHEAST GULF OF MEXICO.
RECENT SURFACE ANALYSIS SHOWED THAT THE SURFACE RIDGE WAS STILL
BEING SUPPRESSED TO THE SOUTH OVER THE NORTH/CENTRAL BAHAMA
ISLANDS...SOUTHERN FLORIDA AND INTO THE SOUTHEAST GULF OF MEXICO.
THE DEEP SOUTHWEST FLOW WILL ADVECT THE MORE MOIST EASTERN GULF OF
MEXICO AIR INTO EAST CENTRAL FLORIDA THROUGHOUT THE DAY. ISOLATED
MORNING SHOWERS AND STORMS OVER THE EASTERN GULF WILL WORK THEIR WAY
INTO THE WESTERN COUNTIES...LAKE AND WESTERN PORTIONS OF
VOLUSIA...ORANGE...SEMINOLE...OKEECHOBEE COUNTIES LATE MORNING AND
EARLY AFTERNOON. DAYTIME HEATING DESTABILIZING THE MOIST AIR MASS
WILL LEAD TO INCREASING COVERAGE...SCATTERED 40 TO 50 PERCENT...OF
SHOWERS AND STORMS MID TO LATE AFTERNOON. MORNING SOUNDING 500MB
TEMPERATURES AT TAMPA AND CAPE CANAVERAL WERE AT -5C AND -6C
DEGREES. AFTERNOON STORMS LOOK TO BE HEAVY RAIN MAKERS BUT THE
FASTER 850-500MB STEERING WIND AT AROUND 15 MPH SUGGESTS THAT
ACCUMULATIONS MAY NOT BE AS MUCH AS IT COULD BE DUE TO FASTER STORM
MOTION. THE EAST COAST SEA BREEZE WILL STRUGGLE TO MAKE IT MUCH PAST
THE INDIAN RIVER LAGOON/U.S. 1 ALONG THE COAST FROM FORT PIERCE
NORTH. LIGHTER WIND AND MORE SOUTHERLY SOUTH OF FORT PIERCE COULD
ALLOW A SOUTH TO SOUTHEAST WIND TO DEVELOP AND PUSH TO THE
INTERSTATE 95 AND FLORIDA TURNPIKE AREA SOUTH OF FORT PIERCE.
PREVIOUS ZONES DISCUSSION
TODAY-TONIGHT...IN THE BATTLE BETWEEN THE EVER PERSISTENT AND
SUPPRESSED ATLANTIC RIDGE AXIS ACROSS SOUTH FLORIDA AND THE EAST
COAST TROUGH...IT APPEARS THAT THE RIDGE WILL BE THE WINNER FOR
TODAY.
THE UPPER LEVEL SHORTWAVE THE DROVE THE WEAK FRONTAL BOUNDARY INTO
THE SOUTHEAST WILL LIFT OUT TO THE NE LATER TODAY...TAKING WITH IT
THE SURFACE LOW AND FURTHER WEAKENING THE FRONTAL ZONE ACROSS FAR N
FLORIDA. MODELS ARE SHOWING MID LEVEL HEIGHT RISES OF A FEW
DECAMETER AND SURFACE PRESSURES UP A FEW MILLIBARS FROM YESTERDAY.
WHILE NOT VERY SIGNIFICANT IN TERMS OF ABSOLUTE NUMBERS...IT WILL
SHIFT THE FLOW A LITTLE MORE SOUTH-SOUTHWEST RATHER THAN THE MORE
RECENT WEST-SOUTHWEST. THIS WILL INITIALLY BETTER TAP INTO THE DRIER
AIR MID LEVEL AIR TO OUR SOUTH...THOUGH NOT QUITE TO THE EXTENT OF
THE 10-20% RHS PRESENT OVER THE NW BAHAMAS. HOWEVER BEHIND THIS
INITIAL DRY AIR PUSH...THERE LOOKS TO BE A POCKET OF HIGHER MOISTURE
ROUNDING THE RIDGE OUT OF THE SE GULF INTO THE PENINSULA INTO THE
AFTERNOON.
THIS ALL LOOKS TO TRANSLATE TO A MORE TYPICAL EARLY-MID AFTERNOON
START OF SHOWERS AND STORMS...MUCH LATER THAN THE PAST FEW
DAYS...AND COVERAGE IN THE 30-40 PERCENT RANGE ACROSS THE REGION.
MESOSCALE MODELS ARE SHOWING BETTER COVERAGE AROUND THE LAKE
OKEECHOBEE/TREASURE COAST REGION THIS AFTERNOON...LIKELY INITIATED
FROM THE CURRENT BAND MOVING INTO THE SW FLORIDA COAST. EAST COAST
SEA BREEZE LOOKS MORE LIKELY...ESPECIALLY SOUTH OF SEBASTIAN
INLET...WITH BETTER INLAND PENETRATION THAN THE PAST FEW DAYS.
HOWEVER STEERING FLOW WILL REMAIN OUT OF THE SOUTHWEST AND THE WEST
COAST SEA BREEZE WILL REMAIN THE DOMINANT CONVECTIVE INITIATOR
UNTIL VARIOUS OUTFLOW AND LAKE BREEZES GET GOING. SHOWERS AND STORMS
WILL LINGER THROUGH THE EVENING HOURS BEFORE PUSHING OFFSHORE.
DUE TO EXPECTED LATER START TO CONVECTION IN MOST LOCATIONS...HIGH
TEMPS WILL LIKELY BE CLOSER TO MOS GUIDANCE THAN PREVIOUS DAYS IN
THE LOW-MID 90S AREA-WIDE.
THU...THE DEEPER PRE-FRONTAL MOISTURE AHEAD OF THE FRONTAL BOUNDARY
ACROSS S GA AND FL PANHANDLE SHOULD BEGIN TO MOVE TOWARD E CENTRAL
FL FROM THE GULF BY THU AFTN. NAM AND GFS PROG PWATS OVER TWO INCHES
WITH FAIRLY DEEP SW FLOW AND A MID LVL IMPULSE PROGGED TO MOVE
ACROSS THE NRN PENINSULA IN THE AFTERNOON. WILL KEEP POPS RUNNING
ABOUT 10 PCT HIGHER THAN THE GFS AND CLOSER TO THE NAM GUIDANCE IN
THE 50-60 PCT RANGE. SHOWERS/STORMS SHOULD DEVELOP ON THE WEST SIDE
OF THE PENINSULA BY LATE MORNING INTO MID DAY AND TRACK EASTWARD
ACROSS E CENTRAL FL THROUGH THE AFTERNOON HOURS. THE EAST COAST SEA
BREEZE WILL BE PINNED NEAR THE COAST ACROSS VOLUSIA COUNTY AND WILL
MOVE ONLY SLOWLY INLAND SOUTH OF THE CAPE IN THE AFTERNOON. HIGHS
MAINLY IN THE LOWER 90S.
FRI...THE SFC RIDGE AXIS WILL REMAIN NEAR THE KEYS WITH LOW LVL FLOW
FROM THE WSW IN THE MORNING BECOMING SW IN THE AFTERNOON AND
SLIGHTLY WEAKER THAN THU. WITH DEEP MOISTURE AND THE EAST COAST SEA
BREEZE DEVELOPING ALONG THE COAST AND PUSHING INLAND SHOULD SEE
ANOTHER ROUND OF HEALTHY COVERAGE OF AFTERNOON SHOWERS AND LIGHTNING
STORMS ACROSS E CENTRAL FL DURING THE AFTERNOON HOURS. MID LEVEL
TEMPS COOL ABOUT A DEG AT H5 TO -7 TO -8 DEGS C WHICH SHOULD LEAD TO
THE POSSIBILITY OF A FEW STRONGER STORMS WITH BOUNDARY COLLISIONS.
WILL HAVE POPS IN THE LIKELY RANGE AROUND 60 PCT WITH HIGHS IN THE
LOWER 90S.
SAT-WED...ON SAT THE LOW LVL RIDGE WILL BEGIN TO LIFT NORTH TWD S FL
WITH ONE MORE DAY OF LOW LVL S/SW FLOW WITH CONTINUED HIGH MOISTURE
LEVELS MAINLY ACROSS NRN PORTIONS OF E CENTRAL FL. WILL CARRY POPS
IN THE 40-50 PCT RANGE WITH SCATTERED AFTERNOON STORMS EXPECTED. THE
SFC RIDGE WILL LIFT NORTHWARD TOWARD CENTRAL FL SUNDAY INTO MONDAY
WITH RAIN CHANCES DECREASING TO 30-40 PCT WITH HIGHEST COVERAGE
ACROSS NRN SECTIONS EACH AFTERNOON. 00Z GFS INDICATES AN EASTERLY
WAVE WILL ROUND THE LOW LVL RIDGE AXIS TUE AND WED AND BRING
ENHANCED MOISTURE LEVELS ONCE AGAIN TO THE AREA. THE 00Z ECMWF IS
SLOWER WITH THE EASTERLY WAVE AND DOES NOT REACH THE AREA BY THE
MIDDLE OF NEXT WEEK. WITH MODEL UNCERTAINTY WILL KEEP MID RANGE
SCATTERED POPS IN THE EXTENDED FOR NEXT TUE/WED. HIGHS AROUND 90/LWR
90S COAST AND LWR-MID 90S INTERIOR. LOWS IN THE 70S THROUGH THE
EXTENDED PERIOD.
&&
.AVIATION...
PREVAILING VFR THROUGH 16Z AS CU DEVELOPS. TEMPO MVFR CEILINGS
18Z-02Z IN/VC SCATTERED STORMS AND SHOWERS. VFR AFTER 14/04Z.
LOCAL MVFR/IFR VISIBILITIES IN/NEAR HEAVIER SHOWERS FROM KDED-KOBE
EAST.
PREVIOUS AVIATION DISCUSSION
PREVAILING VFR THROUGH 14Z WITH OCCASIONAL MVFR CIGS IN CU AFTER
DAYBREAK. ISOLD SHRA/TSRA DEVELOPING ACROSS REGION AFTER 14Z
BECOMING SCT AFTER 17Z AS WEST COAST SEA BREEZE MOVES THROUGH
REGION. GUSTS 35KTS POSSIBLE IN STRONGER STORMS. BEST COVERAGE
LIKELY TOWARDS KMLB-KSUA COAST WITH SEA/LAKE BREEZE COLLISION. EAST
COAST SEA BREEZE DEVELOPMENT EXPECTED KFPR/KSUA AFTER 18Z...MORE
UNCERTAIN AT KMLB AND KVRB WHICH ARE LIKELY TO SEE AT LEAST S WINDS.
&&
.MARINE...
CURRENT-THIS AFTERNOON...THE NOAA BUOYS AND CMAN BUOYS AT PORT
CANAVERAL AND SEBASTIAN INLET WERE RECORDING SOUTHWEST WINDS 7 TO 14
KNOTS AT 10AM. THE THREE NEARSHORE BUOYS WERE RECORDING 1 FOOT SEAS
OUT TO 20NM.
SEA BREEZE COMPONENT VERO BEACH FORT PIERCE INLET SOUTH MID TO LATE
AFTERNOON OTHERWISE SOUTHWEST WIND 10 TO 15 KNOTS BEYOND A FEW MILES
OF SHORE AND AROUND 10 KNOTS JUST OFF THE COAST.
PREVIOUS MARINE DISCUSSION
TODAY-TONIGHT...SLIGHT NORTHWARD SHIFT IN RIDGE AXIS ALONG WITH
WEAKENING OF FRONTAL BOUNDARY WILL KEEP THE GRADIENT LOOSER WITH
PREVAILING WINDS MORE SOUTH-SOUTHWEST AROUND 10KTS...OCCASIONALLY UP
TO 15 KNOTS OFFSHORE. EAST COAST SEA BREEZE EXPECTED SOUTH OF
SEBASTIAN INLET...BRINGING WINDS S-SE NEAR THE COAST IN THE
AFTERNOON. SEAS CONTINUE AROUND 1-2FT WITH UP TO 3 FT WELL OFFSHORE.
SEAS REMAIN CHOPPY WITH DOMINANT PERIODS REMAIN MIXED BETWEEN 8-9SEC
AND 3-4SEC. SHORTER PERIODS EXPECTED TO DOMINATE EARLY BECOMING
LONGER INTO THIS EVENING.
OFFSHORE MOVING STORMS THIS AFTERNOON AND EVENING WITH GUSTY WINDS
IN EXCESS OF 35 KNOTS WILL REMAIN THE PRIMARY BOATING THREAT.
S/SW WINDS TO 10-15 KNOTS INTO THE WEEKEND WITH OFFSHORE MOVING
STORMS EACH AFTERNOON THU-SAT. LOWER COVERAGE OF STORMS IS EXPECTED
SUNDAY AND MONDAY. SEAS 2 FT NEAR THE COAST AND UP TO 3-4 FT WELL
OFFSHORE TOWARD THE WEEKEND.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...WIMMER
IMPACT WX...CRISTALDI
PUBLIC SV...GLITTO
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
953 AM EDT WED AUG 13 2014
.UPDATE...STALLED FRONTAL BOUNDARY OVER SOUTHERN GEORGIA IN
CONCERT WITH MOIST AIRMASS AND MID LEVEL VORT FORECAST TO TRACK
FROM THE GULF OF MEXICO TO ADJACENT AND PARALLEL TO THE ST MARY`S
RIVER. THE HIGH RESOLUTION ARW AND HRRR SHOW BEST CONVERGENCE AND
NUMEROUS SHOWERS/TSTMS ALONG THE ST MARY`S RIVER THROUGH THE LATE
MORNING AND EARLY AFTERNOON WITH THE REMAINDER OF THE FORECAST
AREA FILLING IN THIS MID TO LATE AFTERNOON WITH SCATTERED SHOWERS.
CLAY...PUTMAN...FLAGER AND ST. JOHNS COUNTIES MAY HAVE MORE
SPOTTY TSTM COVERAGE THIS AFTERNOON WITH WITH SUPPRESSED ATLANTIC
RIDGE AXIS ACROSS SOUTH FLORIDA. BEST AREAL COVERAGE...THIS
AFTERNOON IS FORECAST TO SOUTH THE ST MARY`S RIVER BUT NORTH OF
LINE FROM CROSS CITY TO ALACHUA TO GREEN COVE SPRINGS TO PONTE
VEDRA.
&&
.AVIATION...
STALLED FRONTAL BOUNDARY CONTINUE TO RESIDE OVER SOUTHERN GA THIS
MORNING AS A RESULT A MOIST SOUTHWEST FLOW WILL CONTINUE THIS TAF
PERIOD. AN INCREASE OF SHOWERS AND THUNDERSTORMS IS ANTICIPATED
THIS AFTERNOON. MOIST ATMOSPHERE IS IN PLACE ACROSS THE REGION.
THE STEERING FLOW IS OUT OF THE SOUTHWEST AT ABOUT 20 KNOTS. WITH
SOME TRAINING POSSIBLE...SOME STORMS MAY PRODUCE A BRIEF PERIOD OF
HEAVY DOWNPOURS RESULTING IN REDUCED VISIBILITIES. SHOWERS AND
THUNDERSTORMS WILL BEGIN TO DECREASE IN AREAL COVERAGE AFTER 00Z
THEN WANING EVEN FURTHER AS THE EVENING PROGRESSES.
&&
.MARINE...
SW FLOW WILL PREVAIL THROUGH THE WEEKEND. WIND SPEEDS OUTSIDE OF
SCATTERED TO NUMEROUS STORMS WILL GENERALLY REMAIN 15 KNOTS OR
LESS...WITH NOCTURNAL WIND SURGES OFFSHORE APPROACHING CAUTION
LEVELS AT TIMES.
RIP CURRENTS: LOW RISK THROUGH THURSDAY WITH OFFSHORE FLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 93 74 93 74 / 50 30 40 30
SSI 89 77 88 76 / 60 50 60 50
JAX 91 76 92 74 / 70 50 60 60
SGJ 90 75 91 75 / 60 50 60 60
GNV 89 74 90 73 / 70 40 60 60
OCF 91 74 90 73 / 50 40 60 60
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
CORDERO/CORDERO/WALSH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1057 AM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LAKE BREEZE WITH WINDS BECOMING NE ARND 11 KT IN THE MID AFTN.
JEE
//DISCUSSION...UPDATED 12Z...
HIGH PRESSURE IS CENTERED WEST OF THE TERMINALS TODAY WHICH WILL
RESULT IN MODEST WNW/NW FLOW THROUGH THE FIRST HALF OF THE DAY. A
WEAK SURFACE TROUGH IS LOCATED OVER WISCONSIN AND WILL DROP SOUTH
ACROSS THE TERMINALS TODAY WITH WINDS FRESHENING UP SLIGHTLY THIS
AFTERNOON. FORECAST SOUNDINGS SHOW WINDS AT THE TOP OF THE MIXED
LAYER NEAR 20 KT...BUT INCREASING CLOUD COVER TODAY SHOULD HELP KEEP
GUSTS IN CHECK...THOUGH DID BUMP SUSTAINED SPEEDS UP SLIGHTLY. AS
THE SURFACE TROUGH MOVES SOUTH ACROSS THE TERMINALS THIS
AFTERNOON/EVENING IT WILL LIKELY COME IN THE FORM OF AN ENHANCED
LAKE BREEZE WHICH WILL SHIFT WINDS TO THE NORTHEAST. THERE MAY BE A
SHORT WINDOW OF 11-13KT WINDS FOR AN HOUR OR TWO BEHIND THE BOUNDARY
BEFORE WINDS SETTLE BACK DOWN BELOW 10 KT THROUGH THE REMAINDER OF
THE FORECAST PERIOD. VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN A LAKE BREEZE...HIGH CONFIDENCE IN TIMING
AND WIND SPEEDS ARND 11 KT.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH FRIDAY...VFR.
FRIDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR BUT WITH PERIODIC
CHANCES FOR TSRA.
BMD
&&
.MARINE...
300 AM CDT
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS LAKE MICHIGAN AS WINDS
AND WAVES DIMINISH BEHIND THE DEPARTING LOW SYSTEM CURRENTLY MOVING
ACROSS THE EASTERN LAKES. A SECONDARY TROUGH WILL WORK ITS WAY SOUTH
ACROSS LAKE MICHIGAN TODAY WITH WINDS PICKING UP SLIGHTLY OUT OF THE
NORTH...ESPECIALLY ACROSS THE NORTH HALF OF THE LAKE WHERE WIND
SPEEDS WILL INCREASE BACK INTO THE 15 TO 25 KT RANGE. HIGH PRESSURE
WILL MOVE ACROSS THE LAKE LATE THURSDAY INTO FRIDAY WITH WINDS THEN
TURNING BACK TO THE SOUTHWEST/SOUTH FRIDAY AND SATURDAY.
BMD
&&
.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:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
906 AM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* LAKE BREEZE WITH WINDS BECOMING NE ARND 11 KT IN THE MID AFTN.
JEE
//DISCUSSION...UPDATED 12Z...
HIGH PRESSURE IS CENTERED WEST OF THE TERMINALS TODAY WHICH WILL
RESULT IN MODEST WNW/NW FLOW THROUGH THE FIRST HALF OF THE DAY. A
WEAK SURFACE TROUGH IS LOCATED OVER WISCONSIN AND WILL DROP SOUTH
ACROSS THE TERMINALS TODAY WITH WINDS FRESHENING UP SLIGHTLY THIS
AFTERNOON. FORECAST SOUNDINGS SHOW WINDS AT THE TOP OF THE MIXED
LAYER NEAR 20 KT...BUT INCREASING CLOUD COVER TODAY SHOULD HELP KEEP
GUSTS IN CHECK...THOUGH DID BUMP SUSTAINED SPEEDS UP SLIGHTLY. AS
THE SURFACE TROUGH MOVES SOUTH ACROSS THE TERMINALS THIS
AFTERNOON/EVENING IT WILL LIKELY COME IN THE FORM OF AN ENHANCED
LAKE BREEZE WHICH WILL SHIFT WINDS TO THE NORTHEAST. THERE MAY BE A
SHORT WINDOW OF 11-13KT WINDS FOR AN HOUR OR TWO BEHIND THE BOUNDARY
BEFORE WINDS SETTLE BACK DOWN BELOW 10 KT THROUGH THE REMAINDER OF
THE FORECAST PERIOD. VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE IN LAKE BREEZE...MEDIUM-HIGH CONFIDENCE IN
TIMING...MAY BE AN HOUR EARLIER THAN CURRENTLY FORECAST.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH FRIDAY...VFR.
FRIDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR BUT WITH PERIODIC
CHANCES FOR TSRA.
BMD
&&
.MARINE...
300 AM CDT
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS LAKE MICHIGAN AS WINDS
AND WAVES DIMINISH BEHIND THE DEPARTING LOW SYSTEM CURRENTLY MOVING
ACROSS THE EASTERN LAKES. A SECONDARY TROUGH WILL WORK ITS WAY SOUTH
ACROSS LAKE MICHIGAN TODAY WITH WINDS PICKING UP SLIGHTLY OUT OF THE
NORTH...ESPECIALLY ACROSS THE NORTH HALF OF THE LAKE WHERE WIND
SPEEDS WILL INCREASE BACK INTO THE 15 TO 25 KT RANGE. HIGH PRESSURE
WILL MOVE ACROSS THE LAKE LATE THURSDAY INTO FRIDAY WITH WINDS THEN
TURNING BACK TO THE SOUTHWEST/SOUTH FRIDAY AND SATURDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
617 AM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* WIND SHIFT TO NORTHEAST THIS AFTERNOON/EVENING.
BMD
//DISCUSSION...UPDATED 12Z...
HIGH PRESSURE IS CENTERED WEST OF THE TERMINALS TODAY WHICH WILL
RESULT IN MODEST WNW/NW FLOW THROUGH THE FIRST HALF OF THE DAY. A
WEAK SURFACE TROUGH IS LOCATED OVER WISCONSIN AND WILL DROP SOUTH
ACROSS THE TERMINALS TODAY WITH WINDS FRESHENING UP SLIGHTLY THIS
AFTERNOON. FORECAST SOUNDINGS SHOW WINDS AT THE TOP OF THE MIXED
LAYER NEAR 20 KT...BUT INCREASING CLOUD COVER TODAY SHOULD HELP KEEP
GUSTS IN CHECK...THOUGH DID BUMP SUSTAINED SPEEDS UP SLIGHTLY. AS
THE SURFACE TROUGH MOVES SOUTH ACROSS THE TERMINALS THIS
AFTERNOON/EVENING IT WILL LIKELY COME IN THE FORM OF AN ENHANCED
LAKE BREEZE WHICH WILL SHIFT WINDS TO THE NORTHEAST. THERE MAY BE A
SHORT WINDOW OF 11-13KT WINDS FOR AN HOUR OR TWO BEHIND THE BOUNDARY
BEFORE WINDS SETTLE BACK DOWN BELOW 10 KT THROUGH THE REMAINDER OF
THE FORECAST PERIOD. VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM-HIGH IN LAKE BREEZE TIMING TO WITHIN AN HOUR OR TWO.
* MEDIUM IN WIND SPEED TODAY.
* HIGH CONFIDENCE IN VFR.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH FRIDAY...VFR.
FRIDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR BUT WITH PERIODIC
CHANCES FOR TSRA.
BMD
&&
.MARINE...
300 AM CDT
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS LAKE MICHIGAN AS WINDS
AND WAVES DIMINISH BEHIND THE DEPARTING LOW SYSTEM CURRENTLY MOVING
ACROSS THE EASTERN LAKES. A SECONDARY TROUGH WILL WORK ITS WAY SOUTH
ACROSS LAKE MICHIGAN TODAY WITH WINDS PICKING UP SLIGHTLY OUT OF THE
NORTH...ESPECIALLY ACROSS THE NORTH HALF OF THE LAKE WHERE WIND
SPEEDS WILL INCREASE BACK INTO THE 15 TO 25 KT RANGE. HIGH PRESSURE
WILL MOVE ACROSS THE LAKE LATE THURSDAY INTO FRIDAY WITH WINDS THEN
TURNING BACK TO THE SOUTHWEST/SOUTH FRIDAY AND SATURDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 10 AM
WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS GOODLAND KS
510 AM MDT WED AUG 13 2014
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 225 AM MDT WED AUG 13 2014
LATEST WV IMAGERY AND RAP ANALYSIS SHOW AMPLIFIED 594 DM RIDGE
CENTERED OVER THE SOUTHERN PLAINS EXTENDING NORTH ACROSS THE CENTRAL
PLAINS/CENTRAL ROCKIES INTO SOUTHERN CANADA. AT THE SURFACE THE LEE
TROUGH IS DEEPENING OVER EASTERN COLORADO WITH HIGH PRESSURE
BEGINNING TO SHIFT TOWARD EASTERN KANSAS.
TODAY-THURSDAY NIGHT...ANOTHER VERY WARM AND DRY DAY IS EXPECTED
TODAY AS H5 RIDGE CONTINUE TO DOMINATE PATTERN OVER THE CWA...AND
MAIN STORM TRACK REMAINS WELL OUTSIDE OUR AREA OF CONCERN. BY MIDDAY
THURSDAY THE NORTHERN EXTENT OF THE RIDGE WILL BEGIN TO FLATTEN IN
RESPONSE TO A SHORTWAVE TROUGH MOVING OUT OF THE FOUR CORNERS REGION
AND INTO THE NORTHERN PLAINS. WHILE INSTABILITY INCREASES...SOUNDING
SHOW HIGH TD DEPRESSIONS BELOW 500MB THROUGH AT LEAST EARLY THURSDAY
AFTERNOON...WHICH COULD LIMIT PRECIPITATION REACHING THE GROUND IN
ALL BUT THE STRONGEST UPDRAFTS UNTIL MID AFTERNOON. BETTER
LIFT/INSTABILITY SHOULD SUPPORT BETTER THUNDERSTORM COVERAGE BY LATE
THURSDAY AFTERNOON AND ESPECIALLY THURSDAY NIGHT...AND MODELS SHOW A
GOOD PRECIP SIGNAL DURING THESE PERIODS. I KEPT SLIGHT CHANCE POPS
IN PLACE MIDDAY THURSDAY...THOUGH CONFIDENCE WASNT HIGH FOR
INITIATION THAT EARLY AND TRENDED POPS UP BY THE EVENING OVERNIGHT
HOURS. BY THURSDAY NIGHT BETTER CAPE PROFILES AND INCREASING PWATS
WOULD SUPPORT THE POSSIBILITY OF LOCALIZED HEAVY RAIN...HOWEVER
THREAT IS UNCERTAIN AT THIS RANGE ESPECIALLY WITH BETTER STORM
MOTIONS. SHEER WILL BE DECENT...HOWEVER CAPE IS MARGINAL...SO
ELEVATED SEVERE THREAT IS UNCERTAIN.
FRIDAY-FRIDAY NIGHT...RIDGE REMAINS IN PLACE OVER THE SOUTHERN
PLAINS WITH NORTHWEST FLOW ALLOWING WEAK MID LEVEL VORTICITY TO
ROTATE THROUGH THE NORTHERN PLAINS. AS PRECIP COMES TO AN END WITH
DEPARTING SHORTWAVE ONLY WEAK FORCING WILL BE IN PLACE. MODERATE
INSTABILITY WILL BUILD BACK OVER THE CWA WITH DAYTIME HEATING...AND
THERE CONTINUES TO BE A WEAK PRECIP SIGNAL BETWEEN THE GFS AND
ECMWF...SO WHILE CONFIDENCE IS NOT HIGH WE WILL SEE MUCH
THUNDERSTORM ACTIVITY SLIGHT CHANCE POPS STILL SEEM REASONABLE FOR
NOW.
REGARDING TEMPS...GUIDANCE CONTINUES TO SHOW GOOD WAA ALONG EASTERN
SIDE OF LEE TROUGH THROUGH THURSDAY. LOW TO MID 90S FOR MOST
LOCATIONS TODAY AND THURSDAY SEEM REASONABLE...THOUGH INCREASING
CLOUD COVER COULD LIMIT WARMING SOME ON THURSDAY. FRIDAY TEMPS COULD
BE A BIT COOLER BEHIND TROUGH AND BUILDING NW FLOW...HOWEVER
GUIDANCE CONTINUES TO SHOW DECENT RECOVERY OF TEMPS ALOFT WITH LEE
TROUGH QUICKLY BUILDING BACK OVER EASTERN COLORADO. I USED CONSENSUS
FOR FRIDAY AS A BEST GUESS WHICH FAVORS SEASONAL TEMPS AROUND 90F.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 225 AM MDT WED AUG 13 2014
AN UPPER LEVEL RIDGE WILL BE POSITIONED OVER THE SOUTHWEST PORTION
OF THE CONUS WITH WESTERLY/NORTHWESTERLY FLOW ALOFT ACROSS THE
CENTRAL HIGH PLAINS. MEDIUM RANGE GUIDANCE DISPLAYS SOME FAIRLY
SIGNIFICANT DIFFERENCES WITH TIMING AND AMPLITUDE OF THE A SHORTWAVE
TROUGH THAT WILL PASS THROUGH ON MONDAY. THE GFS IS THE MOST
AMPLIFIED AND HAS THE STRONGEST FORCING BUT SEVERAL GFS ENSEMBLE
MEMBERS DISPLAY LESS AMPLITUDE SIMILAR TO THE DETERMINISTIC ECMWF.
THIS LEADS TO UNCERTAINTY WITH REGARDS TO AMOUNT OF CONVECTION.
ASIDE FROM THIS SHORTWAVE THE PATTERN REMAINS FAIRLY BENIGN WITH
NEAR OR SLIGHTLY ABOVE NORMAL TEMPERATURES THROUGH THE ENTIRE
PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 510 AM MDT WED AUG 13 2014
VFR CONDITIONS WILL CONTINUE AT BOTH KGLD AND KMCK THROUGH THE
TAF PERIOD. SOUTHEASTERLY WINDS WILL INCREASE DURING THE DAY WITH
GUSTS 18-22KT. THESE GUSTS WILL DIMINISH AFTER SUNSET.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...DR
AREA FORECAST DISCUSSION
NWS BILLINGS MT
841 AM MDT WED AUG 13 2014
.UPDATE...
ISOLATED SHOWERS CONTINUE TO DEVELOP ACROSS PARTS OF THE CWA THIS
MORNING IN RESPONSE TO SHORTWAVE LIFTING OUT OF NORTHWEST WY. HAVE
ADJUSTED MORNING POPS TO ACCOUNT FOR THIS ACTIVITY...WHICH EXTENDS
FROM NEAR BILLINGS AND HARLOWTON OVER TO MILES CITY. SHORTWAVE
WILL PUSH SLOWLY TO THE NORTHEAST AND SHOULD BE A FOCUS FOR
THUNDERSTORM DEVELOPMENT IN OUR EASTERN ZONES THIS AFTN. LATEST
SSEO/SREF HIGHLIGHT AREAS FROM MILES CITY TO BROADUS EASTWARD FOR
CONVECTION LATER TODAY. THOUGH SHEAR MAGNITUDE IS GENERALLY
WEAK...FAVORABLE DIRECTIONAL SHEAR AND CAPES OF 1000-1500 J/KG
COULD SUPPORT SOME STRONGER STORMS WITH SMALL HAIL AND HEAVY
RAIN. HAVE RAISED POPS TO SCATTERED IN THIS AREA. ELSEWHERE...WEAK
ENERGY FROM THE GREAT BASIN WILL PRODUCE ANOTHER ROUND OF
RELATIVELY HIGH-BASED CONVECTION IN OUR WEST THIS AFTN AND
EVENING...WITH GUSTY WINDS AGAIN BEING THE MAIN THREAT...BUT
OVERALL STRONGER FORCING ASSOCIATED WITH PACIFIC NW LOW WILL
REMAIN TO OUR WEST. OUR CENTRAL PARTS INCLUDING BILLINGS WILL BE
LEAST FAVORED FOR STORMS TODAY SO WILL KEEP POPS AT ISOLATED.
TEMPS WILL BE ABOVE NORMAL BUT SHOULD NOT BE QUITE AS WARM AS
TUESDAY...WHEN 100F WAS REACHED AT OUR OFFICE ON THE WEST END OF
BILLINGS.
JKL
&&
.SHORT TERM...VALID FOR TDY AND THU...
UPPER LEVEL RIDGE THAT HAS BEEN IN PLACE FOR THE LAST SEVERAL DAYS
WILL GIVE WAY TO A SHORTWAVE TROUGH...BRINGING WITH IT SOME
POTENTIAL FOR SENSIBLE WEATHER FOR SOUTHEASTERN MONTANA.
DURING THE OVERNIGHT HOURS...THE HRRR MODEL DID A FAIRLY GOOD JOB
OF DEPICTING CONVECTION IN WESTERN MONTANA. AFTER CLOSER LOOK AT
THE LAST FEW RUNS...DECIDED TO ADD A SLIGHT CHANCE OF AN ISOLATED
SHOWER IN THE CENTRAL ZONES...INCLUDING AREAS IN AND AROUND
BILLINGS AROUND 1800 UTC.
AMOUNT OF CLOUD COVER IS GOING TO BE AN ISSUE TODAY WITH RESPECT
TO HIGH TEMPS...AS THE TIMING OF THE ARRIVAL OF ADDITIONAL
MONSOONAL MOISTURE MAY KEEP THE SKIES CLOUDIER THAN INITIALLY
THOUGHT IN PREVIOUS FORECAST PERIODS...PRECLUDING THE FULL
POTENTIAL FOR MAXING OUT. AT 200 AM...IT WAS STILL 74 DEGREES AT
KBIL AND 72 AT KMLS. SO...KEPT WITH GOING FORECAST FOR THE MID 90S
FOR TODAY...ALTHOUGH COULD EASILY SEE KBIL OR KMLS APPROACH THE
CENTURY MARK IF THE CLOUDS CLEAR OUT.
IN PATTERNS LIKE THIS...ITS ALWAYS A GOOD IDEA TO KEEP A WATCH ON
THE POTENTIAL FOR FIRE STARTS DUE TO DRY THUNDERSTORMS. SPC
FIRE OUTLOOK PLACES CENTRAL MONTANA UNDER AN ISOLATED DRY
THUNDERSTORM RISK FOR WEDNESDAY...MAINLY DUE TO THE HOT AND DRY
NATURE OF THE PAST SEVERAL DAYS. WITH AN ISOLATED THREAT OF
THUNDERSTORMS...POTENTIAL LIGHTNING STRIKES COULD IGNITE SOME
STARTS...SIMILAR TO WHAT WAS SEEN ON TUESDAY. EITHER WAY IT BEARS
WATCHING.
THURSDAY SHOULD NOT BE QUITE AS WARM AS TUESDAY AND WEDNESDAY...AS
THE REGION CONTINUES TO BE UNDER GENERAL TROUGHINESS. BEST
DIVERGENCE PROGGED TO REMAIN TO THE NORTH AND WEST OF THE BYZ
CWA...BUT KEPT POP CHANCES FROM 40 TO 50 IN FAR WESTERN ZONES FOR
AN ISOLATED THUNDERSTORM TO FORM. NEITHER INSTABILITY OR SHEAR IS
THAT GREAT...SO ANY STORMS THAT FORM SHOULD NOT BE SEVERE IN
NATURE. SINGER
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
THE CHANCE OF SHOWERS AND THUNDERSTORMS CONTINUES TO LOOK ELEVATED
FRI AND SAT /ESPECIALLY IN SOUTHEASTERN MT/ AS THE UPPER-LEVEL LOW
CURRENTLY OVER THE PACIFIC NORTHWEST FILLS AND MIGRATES NORTHEAST.
THE 00 UTC GUIDANCE CONTINUES TO WAVER A BIT ON THE DETAILS OF THE
DEAMPLIFYING WAVE...BUT OFFERS ENOUGH AGREEMENT FOR US TO CONTINUE
ADVERTISING CHANCE-STYLE POPS EVERYWHERE FRI AND OVER SOUTHEASTERN
MT ON SAT. GIVEN THE TRENDS IN THE GFS AND ECMWF...IT APPEARS THAT
1/ A MONSOONAL MOISTURE PUSH THAT GETS PULLED NORTHWARD IN ADVANCE
OF THE UPPER-LEVEL LOW MAY ENHANCE PRECIPITATION OVER SOUTHEASTERN
MT ON FRI...AND 2/ SHEAR AND INSTABILITY COULD SUPPORT SOME SEVERE
THUNDERSTORM RISK IN SOUTHEASTERN MT ON SAT IF STORMS FIRE THERE.
BY LATER IN THE WEEKEND AND INTO NEXT WEEK...IT APPEARS THE LARGE-
SCALE FLOW FROM THE PACIFIC OCEAN INTO WESTERN NORTH AMERICA COULD
RESHUFFLE WITH A PERSISTENT 500-MB LOW ACROSS THE ALEUTIAN ISLANDS
PERHAPS GETTING REPLACED BY MEAN RIDGING. THE INTERIM EFFECT LOOKS
TO BE ZONAL FLOW ALOFT OVER THE LOCAL REGION WITH DIURNALLY-DRIVEN
LOW-END CONVECTIVE CHANCES AND SEASONABLY WARM TEMPERATURES DURING
THE SUN THROUGH TUE PERIOD...AT LEAST. HOWEVER...IF THE FULL-SCALE
RESHUFFLING TAKES PLACE AS THE 00 UTC GFS AND ECMWF SIMULATED...IT
IS VERY POSSIBLE THAT MEAN TROUGHING COULD BECOME ESTABLISHED OVER
THE NORTHERN ROCKIES OR NORTHERN PLAINS BY LATE NEXT WEEK AND THUS
LEAD TO COOLER AND POTENTIALLY WETTER CONDITIONS. THE JURY IS VERY
FAR FROM OUT ON THAT THOUGH AS PREDICTABILITY IS LOW REGARDING ANY
CHANGE LIKE THAT...MUCH LESS AT THIS TIME OF THE YEAR WHEN THERMAL
IMBALANCE AND DYNAMIC FORCING IN THE NORTHERN HEMISPHERE TYPICALLY
IS AT AN OVERALL MINIMUM. SCHULTZ
&&
.AVIATION...
ISOLATED TO WIDELY SCATTERED SHOWERS AND STORMS ARE EXPECTED
TODAY AND TONIGHT. LOCAL MVFR CONDITIONS...GUSTY WINDS AND SOME
MOUNTAIN OBSCURATIONS ARE POSSIBLE WITH THAT ACTIVITY...BUT THE
PROBABILITY OF IMPACT AT ANY ONE LOCATION IS NOT THAT HIGH. VFR
CONDITIONS ARE OTHERWISE EXPECTED OVER SOUTHERN MT AND NORTH
CENTRAL WY. SCHULTZ
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 095 065/092 063/090 062/088 061/088 061/088 061/090
2/T 23/T 43/T 32/T 22/T 22/T 22/T
LVM 092 057/090 054/088 053/087 052/088 052/088 053/089
3/T 45/T 54/T 42/T 22/T 22/T 22/T
HDN 097 063/095 063/091 060/090 058/090 058/090 058/092
2/T 23/T 43/T 32/T 22/T 22/T 22/T
MLS 097 066/096 066/089 064/090 061/089 061/090 061/091
3/T 22/T 44/T 44/T 42/T 22/T 22/T
4BQ 096 064/094 064/088 063/089 060/089 059/090 059/090
3/T 22/T 44/T 43/T 32/T 22/T 22/T
BHK 094 062/093 061/087 059/087 056/086 056/087 055/087
3/T 32/T 34/T 44/T 42/T 22/T 22/T
SHR 094 059/089 058/089 057/089 054/088 054/088 054/089
2/T 23/T 43/T 32/T 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
733 AM EDT WED AUG 13 2014
.SYNOPSIS...
A COLD FRONT WILL SLOWLY PUSH OFFSHORE TODAY. HIGH PRESSURE WILL BUILD
INTO THE REGION THURSDAY. A WEAK FRONT WILL APPROACH THU NIGHT AND
LINGER ACROSS THE AREA FRIDAY. HIGH PRESSURE WILL SHIFT OFF THE
COAST SATURDAY AND REMAIN THERE WITH A TROUGH DEVELOPING INLAND
THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 733 AM WED...THE ATMOSPHERE REMAINS UNSTABLE WITH A WARM SW
FLOW PER RAP SOUNDINGS AND KMHX VWP...THOUGH LACK OF TRIGGERING
MECHANISM PROHIBITING CONVECTION THIS MORNING. CONDITIONS WARM AND
MUGGY WITH LOW/MID 70S INLAND TO UPR 70S ON THE COAST. PATCHY FOG
AND LOW STRATUS WILL BURN OFF SHORTLY.
POSITIVELY TILTED UPR TROUGH LOCATED ACROSS THE SPINE OF THE
SOUTHERN AND CENTRAL APPALACHIANS THIS MORNING PER H20 VAPOR
IMAGERY WILL SWING THROUGH EASTERN NC THIS AFTERNOON. THIS WILL
PROVIDE DECENT UPR FORCING AND DEEP LAYER SHEAR ACROSS THE EASTERN
FA...AND SHOULD THERE BE ENOUGH MOISTURE AVAILABILITY... COULD
SPUR THUNDERSTORM DEVELOPMENT MAINLY EAST OF HWY 17 THIS
AFTERNOON. THE KEY FACTOR WILL BE MOISTURE AVAILABILITY IN THE MID
LEVELS...WITH GFS/ECM KEEPING THE AREA DRY. NAM/SREF SOUNDINGS
HOWEVER ARE MORE AGGRESSIVE WITH INSTABILITY/MOISTURE...AND ON PAR
WITH NSSL WRF IN CONVECTIVE DEVELOPMENT NEAR THE COAST AFT 16Z.
ANY BACKING OF WINDS AHEAD OF SLOW MOVING COLD FRONT MOVING
THROUGH WOULD ENHANCE THE SFC BASED INSTABILITY AND WITH 30-35 KT
OF SHEAR IN PLACE...COULD GENERATE AN ISO STRONG/SEVERE
THUNDERSTORM. DUE TO THE UNCERTAINTY...WILL CAP POPS IN THE LOW
CHANCE/SCT RANGE FAR EASTERN AREAS...WITH NO POPS ACROSS THE
COASTAL PLAIN COUNTIES.
&&
.SHORT TERM /TONIGHT/...
AS OF 330 AM WED...ANY PRECIP WILL QUICKLY WANE AND SHIFT OFFSHORE
BY EVENING AS DRY AIR IS USHERED IN BEHIND FRONTAL PASSAGE. SFC
DEWPOINTS WILL DROP TO THE LOWER/MIDDLE 60S AND COMBINED WITH
LIGHT/CALM WINDS AND CLEARING SKIES...ALLOW TEMPS TO DROP
COMFORTABLY INTO THE 60S AREA WIDE...WITH LOW 70S IMMEDIATE COAST.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 315 AM WED...WEAK SFC HIGH PRES BUILDS INTO THE REGION THURS
WITH CYCLONIC FLOW CONTINUING ALOFT WITH AN UPPER LOW SLOWLY
PUSHING EAST ACROSS QUEBEC. A VERY DRY AIRMASS WILL BE IN PLACE FOR
AUGUST WITH PWATS BELOW 1"...AROUND 2 SD BELOW NORMAL...AND EXPECT
DRY CONDITIONS TO PREVAIL WITH COMFORTABLE TEMPS IN THE 80S WITH
DEWPOINTS IN THE LOWER 60S.
A SHORTWAVE MOVES THROUGH THE FLOW ALOFT LATE IN THE WEEK WITH A
WEAK TROF/BACKDOOR FRONT MOVING INTO THE REGION FRI. PWATS INCREASE
TO AROUND 1-1.25" WITH SHORTWAVE ENERGY AND FRONTAL CONVERGENCE
PROVIDING SUPPORT FOR ISOL TSTMS THROUGH PEAK HEATING. THE TROF
LINGERS ACROSS THE AREA THROUGH SATURDAY BEFORE DISSIPATING WITH
THE PIEDMONT TROF DEVELOPING INLAND AND HIGH PRESSURE CENTERED WELL
OFFSHORE PRODUCING DEEP SOUTHERLY FLOW ACROSS THE AREA. EXPECT
ISOLATED...MAINLY DIURNALLY DRIVEN CONVECTION ALONG THE SEABREEZE OR
INLAND TROUGH TO PERSIST SAT AND SUN.
MODELS DIVERGE IN THE TIMING AND STRENGTH OF A SHORTWAVE MOVING
THROUGH THE UPPER TROUGH ACROSS THE EAST COAST SUN NIGHT INTO MON.
THE GFS IS FASTER/STRONGER BRINGING INCREASING SUPPORT FOR SHOWERS
AND THUNDERSTORMS ACROSS THE REGION EARLY NEXT WEEK...HOWEVER TREND
IS TO FAVOR THE SLOWER AND WEAKER SOLUTION OF THE ECENS. FOLLOWED
CLOSELY TO WPC GUIDANCE EARLY NEXT WEEK CONTINUING THE TYPICAL
DIURNALLY DRIVEN CONVECTION.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 733 AM WED...MAINLY VFR CONDITIONS THROUGH THE PERIOD. WINDS
WILL BE GENERALLY W TO WNW TODAY BEHIND A COLD FRONTAL PASSAGE.
WINDS DROP TO CALM TONIGHT WITH CLEAR SKIES. ONLY A SMALL CHANCE
FOR LIGHT FOG TONIGHT AS DRY AIR FILTERS INTO THE REGION.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM WED...VFR CONDITIONS EXPECTED TO DOMINATE THROUGH MUCH
OF THE LONG TERM. HIGH PRES BUILDS ACROSS THE AREA THURS BRINGING
DRY CONDITIONS...THEN WILL SEE MOISTURE GRADUALLY INCREASE THROUGH
THE REST OF THE LONG TERM WITH ISOL...MAINLY DIURNALLY DRIVEN...
CONVECTION EACH AFTERNOON ALONG THE INLAND TROUGH OR SEABREEZE.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 330 AM WED...WINDS ARE SW TO W EARLY THIS MORNING IN THE
10-15 KT RANGE...THOUGH GUSTING AT TIMES TO 20 KT. SEAS RANGE FROM
2 TO 4 FT. THE W TO SW FLOW WILL CONTINUE IN THIS RANGE THROUGH
THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. COULD SEE SOME
SEAS TOPPING OUT AT 5 FT ACROSS SOUTHERN/CENTRAL WATERS TODAY. THE
WINDS TURN NW TO EVENTUALLY NORTH LATE TONIGHT BEHIND THE COLD
FRONT...THOUGH WILL GENERALLY REMAIN IN THE 10-15 KT RANGE.
LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 315 AM WED...LIGHT AND VARIABLE WINDS THURS WITH HIGH PRES
ACROSS THE AREA WHILE SEAS SUBSIDING THROUGH THE DAY. THE HIGH
SLIDES OFFSHORE DURING THE LATTER HALF OF THE WEEK WITH WINDS
VEERING TO SLY MAINLY 10 KT OR LESS AND SEAS GENERALLY 1 TO 3 FT.
WINDS MAY BECOME VARIABLE NORTHERN WATERS FRI WITH A BACKDOOR FRONT
POTENTIALLY MOVING INTO THE AREA FOR A BRIEF PERIOD...STILL SOME
DIFFERENCES AMONG THE MODELS JUST HOW FAR THE FRONT WILL PUSH INTO
THE REGION. WINDS RETURN TO SOUTHERLY BY FRIDAY NIGHT AND REMAIN
LIGHT...MAINLY BELOW 15 KT INTO SAT NIGHT. DISCOUNTING THE GFS AND
SUBSEQUENTLY WAVEWATCH III SAT NIGHT AND SUN AS IT IS ANOMALOUSLY
FAST AND STRONG BRINGING A ROBUST SHORTWAVE TROUGH AND ATTENDANT LOW
PRES SYSTEM ACROSS THE MID ATLANTIC...SUBSEQUENTLY BRINGING SW WINDS
TO 20-25 KT AND SEAS AS HIGH AS 5-8 FT ACROSS THE EASTERN NC WATERS
ON SUN. INSTEAD USED A BLEND OF THE ECMWF AND WPC GUIDANCE BRINGING
SW WINDS AROUND 10-15 KT AND KEEPING SEAS AROUND 2-4 FT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TL
NEAR TERM...TL
SHORT TERM...TL
LONG TERM...SK
AVIATION...SK/TL
MARINE...SK/TL
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1034 AM CDT WED AUG 13 2014
.AVIATION/18Z TAFS/...CONTINUED VFR THIS PERIOD. SURFACE FRONT
WILL MOVE THROUGH SRN WI THIS AFTN AND EXIT TO THE SOUTH THIS
EVENING...SO WINDS WILL SHIFT NW-N-NE IN FAIRLY SHORT ORDER. SCT-
BKN MID CLOUDS SHIFTING SOUTH OF TAF SITES...THOUGH SOME CU
DEVELOPMENT POSSIBLE PER CU RULE. RAP SOUNDINGS SHOW PLENTY OF DRY
AIR WITHIN THE COLUMN WITH PARCEL TRAJ GETTING CAPPED OFF AROUND
10K FEET. HIGH PRESSURE SETTLES IN AND DOMINATES TONIGHT INTO
THURSDAY WITH VERY DRY AND STABLE AIRMASS.
PC
&&
.PREV DISCUSSION... /ISSUED 319 AM CDT WED AUG 13 2014/
TODAY...FORECAST CONFIDENCE IS HIGH.
A WEAK COLD FRONT WILL BE DROPPING SOUTH THROUGH THE STATE
TODAY...REACHING SOUTHERN WISCONSIN AT PEAK HEATING. THE
ATMOSPHERE IS PRETTY DRY...BUT THE FRONT DOES BRING WITH IT SOME
HIGHER SURFACE DEW POINTS. IN THE MID LEVELS...A SHORT WAVE TROF
WILL BE DROPPING SOUTH THROUGH THE BACK SIDE OF THE PARENT UPPER
LOW NORTHEAST OF THE GREAT LAKES. THIS BRINGS AN INCREASE IN THE
CYCLONIC FLOW ALOFT AT THE SAME TIME THE FRONT IS MOVING THROUGH.
THE COLD FRONT SHOULD GET SOME ENHANCEMENT BOTH IN TEMP CONTRAST
AND LOW LEVEL CONVERGENCE FROM INCREASING NORTHEAST WINDS ON THE
BACK SIDE OF THE COLD FRONT. THE NAM IS THE MOST AGGRESSIVE WITH
THE POTENTIAL INSTABILITY...WHILE THE GFS SHOWS A RATHER STRONG
ELEVATED WARM LAYER...CAPPING THINGS OFF. MANY OF THE MODELS ARE
KICKING OUT SOME VERY LIGHT AND SPLOTCHY QPF THIS AFTERNOON.
THEREFORE WILL INTRODUCE SOME SLIGHT CHANCES TO THE AREA AFTER
18Z. THIS SHOULD ALL BE SOUTH OF THE BORDER BY EVENING.
TONIGHT...FORECAST CONFIDENCE IS HIGH.
COOL...DRY AIR IN THE WAKE OF THE FRONT WILL BRING CLEAR SKIES TO
THE AREA TONIGHT. SOME RIVER FOG POSSIBLE.
SHORT TERM...THURSDAY THROUGH FRIDAY NIGHT...FORECAST CONFIDENCE
IS MEDIUM.
MODELS SHOWING 500 MB TROUGH SLOWLY MOVING WELL EAST OF THE
REGION DURING THIS PERIOD...WITH NORTHWEST FLOW LINGERING ACROSS
THE AREA. HIGH PRESSURE AT THE SURFACE SLIDES SOUTHEAST ACROSS
THE REGION THURSDAY...THEN SOUTHEAST OF THE AREA THURSDAY NIGHT
AND FRIDAY. THE HIGH WILL BRING QUIET WEATHER AND PLEASANT
TEMPERATURES FOR THURSDAY.
MODELS THEN SHOW WARM AIR ADVECTION IN THE LOW LEVELS OCCURRING
ACROSS THE REGION THURSDAY NIGHT INTO FRIDAY. THIS WILL BRING
WARMER AND MORE MOIST AIR INTO THE REGION. NAM/ECMWF MODELS ARE
ABOUT 12 HOURS SLOWER THAN GFS/CANADIAN MODELS WITH TIMING OF LOW
PRESSURE MOVING EAST FROM THE NORTH CENTRAL PLAINS STATES FRIDAY
INTO FRIDAY NIGHT. THEY ALL KEEP MAIN 500 MB SHORTWAVE TROUGH TO
THE SOUTHWEST OF THE AREA. MODELS ALSO DIFFER WITH PLACEMENT OF
850 MB LOW LEVEL JET AXIS AND NOSE FRIDAY NIGHT. FOR NOW...WILL
CONTINUE WITH CHANCE POPS FOR FRIDAY AFTERNOON INTO FRIDAY NIGHT.
LONG TERM...SATURDAY THROUGH TUESDAY...FORECAST CONFIDENCE IS
MEDIUM.
ECMWF/GFS CONTINUE TO DIFFER WITH TIMING AND PLACEMENT OF FEATURES
DURING THIS PERIOD. GFS IS ABOUT 24 HOURS QUICKER THAN ECMWF WITH
LOW PRESSURE AND 500 MB SHORTWAVE TROUGH MOVING TO THE SOUTH OF
THE AREA SATURDAY INTO SUNDAY. THEY ALSO DIFFER WITH THE FOLLOWING
SYSTEM FOR MONDAY INTO TUESDAY.
FOR NOW...WILL USE CONSENSUS BLEND OF MODELS FOR POPS AND
TEMPERATURES IN THIS PERIOD. MEAN LAYER AND ELEVATED CAPE IS
QUESTIONABLE IN THE SATURDAY NIGHT INTO SUNDAY NIGHT PERIOD...SO
WENT WITH JUST SLIGHT CHANCES FOR THUNDER IN THIS PERIOD. WARM
AND HUMID CONDITIONS SHOULD OCCUR DURING THIS TIME.
AVIATION/12Z TAFS/...
LOOK FOR VFR CONDITIONS THROUGH THE TAF PERIOD. THERE IS A WEAK
COLD FRONT DROPPING SOUTH THROUGH THE AREA THIS AFTERNOON AND IT
MAY TRIGGER SOME ISOLATED SHOWERS WITHIN A FAIRLY DRY ATMOSPHERE.
WINDS WILL SHIFT TO THE NORTH THEN NORTHEAST IN THE WAKE OF THE
FRONT. THOSE WINDS MAY GUST TO AROUND 20KTS BRIEFLY IN THE WAKE OF
THE FRONT IN THE MILWAUKEE AND KENOSHA AREAS AROUND 21Z TO 22Z
THIS AFTERNOON. THOSE WINDS WILL QUICKLY SETTLE DOWN WITH LIGHT
WINDS EXPECTED AFTER SUNSET.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...DAVIS
THURSDAY THROUGH TUESDAY...WOOD
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
554 AM CDT WED AUG 13 2014
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 156 AM CDT WED AUG 13 2014
RELATIVELY QUIET PERIOD. MAIN CONCERN IS WEAK BACK DOOR COLD FRONT
THAT WILL SLIDE ACROSS AREA DURING FIRST PART OF DAY. 13/00Z
NAM/GFS/ECMWF AND 13/03Z HRRR ALL INDICATE PRECIP WILL FORM SOUTH
OF FORECAST AREA THIS AFTERNOON ASSOC WITH BETTER INSTABILITY. AT
THAT POINT FRONT WILL BE ALONG OR SOUTH OF SOUTHERN BORDER OF FORECAST
AREA. NE WINDS MAY PICK UP FOR A BRIEF TIME BEHIND FRONT LATE
AFTERNOON INTO EARLY EVENING...THEN SFC HIGH PRESSURE MOVES SOUTH FROM
HUDSON BAY PROVIDING COOL NIGHT AND MILD THURSDAY. TEMPS TONIGHT
WILL PROBABLY TOUCH THE 30S IN FAR NORTHERN BOGS.
TEMP AND WIND FORECAST A BLEND OF PREVIOUS FORECAST WITH BEST
PERFORMING MODEL GUIDANCE.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 156 AM CDT WED AUG 13 2014
NORTHWEST FLOW ALOFT DUE TO UPPER LOW ACROSS EASTERN CANADA WILL
BECOME MORE ZONAL BY THE WEEKEND. UPPER PATTERN SUCH THAT MODELS
ARE HAVING A HARD TIME WITH FEATURES AND WHEN AND WHERE BEST
CHANCES OF RAIN WOULD OCCUR. TEMPERATURES DURING THE PERIOD SHOULD
BE AT OR SLIGHTLY ABOVE NORMAL FOR MID AUGUST.
MODELS CONTINUE TO DIFFER IF PRECIPITATION WOULD BREAK OUT ON THE
BACKSIDE OF THE HIGH DUE TO 850MB WARM ADVECTION. LEANING TOWARD
SHOWERS AND STORMS BREAKING OUT WEST OF THE AREA THURSDAY NIGHT...
THUS LEFT THIS PERIOD DRY. WILL CONTINUE THE CHANCES FOR SHOWERS
AND STORMS FRIDAY AS BOUNDARY PUSHES NORTH. A CONTINUED CHANCE FOR
SHOWERS AND STORMS WILL CONTINUE FRIDAY NIGHT AND SATURDAY. UPPER
FLOW STILL NORTHWEST AT THIS POINT...THUS EXPECT BOUNDARY TO PUSH
SOUTH OF THE AREA SATURDAY NIGHT AND SUNDAY. HAVE REMOVED RAIN
CHANCES ACROSS THE NORTH SATURDAY NIGHT AND SUNDAY AS HIGH PRESSURE
BUILDS INTO THE AREA. ALMOST TEMPTED TO REMOVE RAIN CHANCES ACROSS
THE SOUTH...BUT CONFIDENCE WAS LOWER IN CASE BOUNDARY SHOULD LINGER
ACROSS THE AREA. BEYOND SUNDAY...LOW CONFIDENCE IN THE DETAILS OF
ANY WEATHER MAKER AND WHEN THE BEST CHANCES FOR SHOWERS AND STORMS
COULD OCCUR. DID NOT MAKE ANY SIGNIFICANT CHANGES BEYOND SUNDAY.
ONLY ADJUSTMENTS TO MAX/MIN TEMPERATURE GRIDS WAS TO ADD A DEGREE
OR TWO AT NIGHT AT THE TYPICALLY WARMER LOCATIONS...AND DROPPED A
DEGREE OR TWO IN THE TYPICAL COOLER SPOTS AT NIGHT.
&&
.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 554 AM CDT WED AUG 13 2014
LOCAL IFR CIGS ACROSS NORTH-CENTRAL WI AIRPORTS ASSOCIATED WITH
AREA OF STRATUS. STRATUS WILL LIFT/DISSIPATE BY 9 AM. VFR CONDITIONS
ELSEWHERE. WINDS WILL SWITCH TO NORTHEAST LATER THIS AFTERNOON
BEHIND BACK DOOR COLD FRONT. GUSTS NEAR 20 KTS POSSIBLE ALONG LAKE
MICHIGAN/DOOR COUNTY FOR A TIME LATE THIS AFTERNOON AND EARLY
EVENING.
PATCHY GROUND FOG EXPECTED BETWEEN 08Z-12Z THURSDAY AM.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....JKL
LONG TERM......ECKBERG
AVIATION.......JKL
AREA FORECAST DISCUSSION
NWS TUCSON AZ
910 AM MST WED AUG 13 2014
.SYNOPSIS...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THROUGH
THIS EVENING. SOME STORMS WILL GENERATE LOCALLY HEAVY RAIN AND
STRONG GUSTY WINDS. A DOWNWARD MOISTURE TREND AND WEAKER FLOW WILL
LEAD TO LESS THUNDERSTORM ACTIVITY FRIDAY AND SATURDAY.
&&
.DISCUSSION...IR/VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
INDICATE PARTLY CLOUDY SKIES TO MOSTLY CLOUDY SKIES ACROSS SE AZ AT
THIS TIME. DEWPOINTS AT LOWER ELEVATIONS VALID 16Z WERE IN THE
60S F...AND THESE TEMPS WERE GENERALLY 2-5 DEGS F HIGHER VERSUS 24
HOURS AGO. SURFACE TEMPS VALID 16Z WERE ABOUT 5-10 DEGS F COOLER
VERSUS THIS TIME TUE. 13/12Z KTWC SOUNDING TOTAL PRECIP WATER WAS
1.74 INCHES...AND THIS VALUE REMAINED ALMOST TWO STANDARD DEVIATIONS
ABOVE NORMAL. HAVE NOTED THAT THE STEERING FLOW FOR SHOWERS/TSTMS
HAS VEERED TO A MORE SWLY COMPONENT VERSUS 24 HOURS AGO. 13/12Z
UPPER AIR PLOTS INDICATED 587 DM LOW PRESSURE CENTERED OVER NWRN
AZ...RIDGE AXIS EXTENDED FROM WEST TEXAS NWD INTO THE NRN CONUS
PLAINS...AND A TROUGH WAS OVER THE PACIFIC NW. LIGHT SLY/SWLY FLOW
PREVAILED OVER SE AZ.
ABUNDANT MOISTURE WILL CONTINUE ACROSS SE AZ THRU TONIGHT AS THE
WEAK UPPER LEVEL LOW PRESSURE SYSTEM THAT ENHANCED SHOWER/TSTM
ACTIVITY TUE MOVES FROM NWRN AZ INTO WRN COLORADO. HOWEVER...HAVE
NOTED ANOTHER WEAK CYCLONIC CIRCULATION SYSTEM VIA WATER VAPOR
IMAGERY OVER NRN SONORA. DESPITE A GENERAL FLOW REGIME THAT WOULD
TEND TO SUPPRESS CONVECTIVE ACTIVITY TO SOME DEGREE...THIS WEAK
SONORAN SYSTEM IN COMBINATION WITH THE AMPLE MOISTURE SHOULD PROVIDE
SCATTERED TO NUMEROUS SHOWERS/TSTMS INTO THIS EVENING. THE 13/14Z
RUC HRRR AND 13/12Z UNIV OF AZ WRF-NAM SOLUTIONS SUPPORT THIS
SCENARIO.
THE MAIN IMPACT AGAIN TODAY WILL BE HEAVY RAIN WITH THE POTENTIAL
FOR FLASH FLOODING TO OCCUR. HOWEVER...LESS COVERAGE OF HEAVY
RAINFALL IS ANTICIPATED INTO THIS EVENING VERSUS TUE. SHOWERS/TSTMS
SHOULD WEAKEN IN INTENSITY AND LESSEN IN COVERAGE LATE THIS EVENING.
A SLIGHT CHANCE OF SHOWERS/TSTMS EXISTS MAINLY FROM TUCSON EWD LATE
TONIGHT INTO EARLY THUR MORNING.
THE INHERITED OFFICIAL FORECAST IS IN GREAT SHAPE AND NO UPDATES ARE
PLANNED AT THIS TIME. PLEASE REFER TO THE ADDITIONAL SECTIONS FOR
FURTHER DETAIL.
&&
.AVIATION...VALID THRU 14/18Z.
SCATTERED TO NUMEROUS -TSRA/-SHRA FROM LATE THIS MORNING INTO THIS
EVENING AS ABUNDANT MOISTURE CONTINUES ACROSS SOUTHEAST ARIZONA.
MVFR VISIBILITIES AND BRIEF WIND GUSTS MAINLY AROUND 40-45 KTS WILL
OCCUR WITH THE STRONGER TSRA. EXPECT THE COVERAGE OF -TSRA/-SHRA TO
DECREASE AFTER 14/04Z WITH ISOLATED -TSRA/-SHRA EAST OF KTUS LATE
TONIGHT INTO THURSDAY MORNING. OTHERWISE...CLOUD DECKS WILL MAINLY
BE AT 5-10K FT AGL AND SURFACE WIND WILL GENERALLY BE LESS THAN 10
KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...PLENTY OF MOISTURE WITH SCATTERED SHOWERS AND
THUNDERSTORMS TODAY AND THURSDAY. SOME DRYING WITH LESS THUNDERSTORM
COVERAGE OVER THE WEEKEND.
&&
.PREV DISCUSSION...STILL ENOUGH MOISTURE FOR AN AVERAGE THUNDERSTORM
DAY THURSDAY...HOWEVER WE START TO PICK UP A BRIEF WESTERLY
COMPONENT TO OUR FLOW AS THE RIDGE STARTS TO REORIENT INTO A LOWER
LATITUDE PARTIAL BLOCKING POSITION. WE SHOULD START TO LOSE THIS
LONG AND DEEP MOISTURE FETCH AT THAT POINT. THIS SHOULD THEN LEAD
INTO OUR DOWNTURN FRIDAY INTO THE WEEKEND EVEN AS THE RIDGE SHIFTS A
LITTLE FURTHER NORTH IN RESPONSE TO THE NORTHERN BASIN LOW LIFTING
TOWARD THE NORTHERN PLAINS. OUR BEST CHANCE OF THUNDERSTORMS WILL BE
TRIMMED BACK TO MAINLY NEAR THE INTERNATIONAL BORDER AND FAR EASTERN
AREAS. SOME RESPITE FROM THIS LATE SUNDAY OR MONDAY WITH THE RIDGE
AXIS TEMPORARILY TRANSITIONING INTO A HIGHER AMPLITUDE JUST EAST OF
US. THAT SHOULD OPEN US BACK UP FOR A DAY OR TWO OF BETTER MOISTURE.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
FRANCIS
PREVIOUS DISCUSSION...MEYER
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1034 AM MDT WED AUG 13 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
EVERYTHING COMING TOGETHER AS EXPECTED WITH MONSOONAL MOISTURE
CONTINUING TO STREAM INTO THE AREA. OBSERVED PWATS IN GRAND
JUNCTION YESTERDAY EVENING REACHED 1.04 INCHES SO PLENTY OF
MOISTURE FOR ANY DISTURBANCES TO WORK WITH. EVEN AT THIS EARLY
HOUR...RADAR IS PICKING UP ON SOME LIGHT RETURNS WHICH NAM AND
HRRR ARE ALSO HIGHLIGHTING. HRRR ALSO SHOWING SOME CONVECTION
FIRING IN A FEW HOURS OVER DURANGO MUCH LIKE YESTERDAY MORNING SO
WILL BE INTERESTING TO SEE IF THIS PANS OUT.
ALL MODELS CONTINUE TO SHOW PLENTY OF PRECIP FOR OUR AREA TODAY
AS UPPER LEVEL SUPPORT IS MINIMAL AT BEST. ONE FLY IN THE OINTMENT
THOUGH IS A VERY WEAK JET STREAK THAT`S FORECAST TO MOVE OVER THE
UT/CO BORDER TODAY PRODUCING SOME FAIRLY NOTICEABLE DIVERGENCE
ALOFT. THE JET STREAK IS REALLY QUITE UNIMPRESSIVE...HOWEVER...A
SIMILAR JET STREAK MOVED OVERHEAD LAST WEEK BRINGING PLENTY OF
FLASH FLOODING AND STORMS TO THE REGION FOR THOSE THAT REMEMBER.
ON THE FLIP SIDE OF THAT...CLOUD COVER MAY INHIBIT STRONGER
CONVECTION TODAY DESPITE ANY UPPER LEVEL SUPPORT. LOOKING
UPSTREAM...SALT LAKE CITY HAD A GANGBUSTERS DAY YESTERDAY WITH
HEAVY RAIN AND STRONG WINDS BEING COMMON. GOING TO FOLLOW THAT LEAD
AND EXPECT THUNDERSTORMS AND SHOWERS TODAY WITH HEAVY
RAIN...STRONG WINDS EXCEEDING 45 MPH...AND HAIL. OBVIOUSLY...THE
FLASH FLOOD WATCH REMAINS IN PLACE. SPEAKING OF...EXTENDED THE WATCH
THROUGH EARLY FRIDAY MORNING AS BOTH THE GFS AND NAM CONTINUE TO
FORM A STRONG SHORTWAVE THAT WILL MOVE OVERHEAD WEDNESDAY NIGHT
INTO THURSDAY. SOME DIFFERENCES IN TIMING AND STRENGTH REMAIN BUT
THINK IT BETTER TO GET WORD OUT NOW.
PLUME OF HEAVY RAIN AND EMBEDDED THUNDERSTORMS ASSOCIATED WITH
THE ELONGATED H5 VORT MAX WILL CONTINUE TO TRACK EAST THROUGH
WESTERN COLORADO TONIGHT AND THURSDAY MORNING. 0-6 KM BULK SHEAR
OF 20-35 KTS IS STILL FORECAST SUGGESTING ORGANIZED MULTICELLS
WITH FLASH FLOODING STILL BEING THE MOST LIKELY IMPACT. STRONG
DOWNDRAFTS AND HAIL ALSO REMAIN POSSIBLE WITH THESE STORMS. THE WEAK
40KT JET ALOFT IS ALSO EXPECTED TO CONTINUE TO PROVIDE SUPPORT FOR
STORM TOP DIVERGENCE THROUGHOUT THE NIGHT. PRECIPITABLE WATER
VALUES WILL TOP OUT AROUND 1.25 INCHES TONIGHT BEFORE DRYING OUT
SLIGHTLY THURSDAY AFTERNOON BEHIND THE DISTURBANCE IN WESTERLY
FLOW. EXPECT A WET THURSDAY MORNING ACROSS MUCH OF WESTERN
COLORADO AS THE BULK OF THE MOISTURE CONTINUES TO TREK EAST. WEAK
RIDGING WILL MOVE INTO THE REGION BEHIND THE DISTURBANCE
PASSAGE...BUT CAPE VALUES THURSDAY AFTERNOON IN EASTERN UTAH
SUGGEST A BATCH OF CONVECTION INITIATING BEHIND THE MAIN AREA OF
RAIN AS SKIES CLEAR THROUGHOUT THE DAY. SEEMS PLAUSIBLE DUE TO
STEEP LAPSE RATES AND PLENTY OF MOISTURE STILL ACCESSIBLE FOR
QUICKLY DEVELOPING THUNDERSTORMS WITH THE BIGGEST THREAT STILL
BEING HEAVY RAIN.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 334 AM MDT WED AUG 13 2014
THURSDAY NIGHT SHOULD BE PRETTY QUIET AS HIGH PRESSURE RETURNS
OVER THE REGION. MOISTURE STUCK UNDER THE RIDGE WILL HELP TO
INITIATE OROGRAPHIC SHOWERS AND THUNDERSTORMS AGAIN ON FRIDAY
AFTERNOON BUT OF AN ISOLATED NATURE.
CONVECTION WILL DIE DOWN QUICKLY NEAR SUNSET FRIDAY EVENING AS
ZONAL FLOW SETS UP OVER THE AREA. HIGH PRESSURE ALSO GETS SET TO
REBUILD INTO THE DESERT SW. AS ANTICYCLONIC FLOW SETS UP OVER THE
CWA...NO MOISTURE IS EXPECTED TO INTRUDE INTO THE AREA ALLOWING
GARDEN VARIETY STORMS TO FIRE EACH AFTN/EVENING. THIS CONTINUES
THROUGH TUESDAY AS MOST AREAS WILL SEE SOME CU BUILD UP EACH AFTN
OVER HIGHER TERRAIN. VALLEYS SHOULD STAY DRY WITH NORMAL
TEMPERATURES EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1034 AM MDT WED AUG 13 2014
SHOWERS AND THUNDERSTORMS WILL INCREASE THROUGH THIS AFTERNOON...
ESPECIALLY OVER THE SOUTH AND WEST. HEAVY RAIN...GUSTY OUTFLOW
WINDS EXCEEDING 40 MPH...AND HAIL WILL BE POSSIBLE. MVFR TO IFR
CIGS/VIS WILL OCCUR UNDER THE STRONGEST CELLS THAT FORM...AND MAY
AT TIMES IMPACT TAF SITES AND OTHER AREA AIRPORTS. THESE
CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS THOUGH INTENSITY
SHOULD DECREASE SOMEWHAT AFTER 04Z.
&&
.HYDROLOGY...
ISSUED AT 334 AM MDT WED AUG 13 2014
FLASH FLOOD WATCH REMAINS IN EFFECT AND HAS BEEN EXTENDED THROUGH
06Z FRIDAY AS DEEP SUBTROPICAL MOISTURE ASSOCIATED WITH THE MONSOONAL
SURGE SLIDES OVER THE AREA. STORMS WILL HAVE SOME MOTION
TODAY BUT EVEN SO...DYNAMIC INPUT AND AMPLE MOISTURE WILL CAUSE
HEAVY RAIN FROM THUNDERSTORMS. RAINFALL OF 1 INCH OR MORE WILL BE
POSSIBLE. LOW LYING AREAS NEAR STEEP TERRAIN AND WILDFIRE BURN
SCARS...SLOT CANYONS AND SLICK ROCK AREAS...NORMALLY DRY
CREEKS...STREAMS AND ARROYOS HAVE THE HIGHEST THREAT OF FLASH
FLOODING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR COZ001>014-
017>019-022-023.
FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR COZ020-021.
UT...FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR UTZ023>025-027.
FLASH FLOOD WATCH THROUGH THURSDAY EVENING FOR UTZ022-028-029.
&&
$$
SHORT TERM...TGR/JAM
LONG TERM...JAM/TGR
AVIATION...EH
HYDROLOGY...TGJT
AREA FORECAST DISCUSSION
NWS ALBANY NY
149 PM EDT WED AUG 13 2014
.SYNOPSIS...
AS AN OCCLUDED FRONT CROSSES THE AREA THIS AFTERNOON...THERE WILL BE
SOME LINGERING RAIN SHOWERS. MOST OF THE SHOWERS WILL TAPER OFF BY
THIS EVENING...ALTHOUGH AN UPPER LEVEL LOW WILL REMAIN ACROSS
SOUTHEAST CANADA...KEEPING SOMEWHAT COOL AND UNSETTLED CONDITIONS
THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 149 PM EDT...AN OCCLUDED FRONT IS CURRENTLY WORKING ACROSS
THE REGION...WITH A TRIPLE POINT LOW JUST SOUTHEAST OF THE REGION
OVER CONNECTICUT.
THE MAJORITY OF THE STEADY MODERATE-HEAVY RAIN IS NOW EAST OF OUR
AREA ACROSS CENTRAL NEW ENGLAND. SOME LINGERING RAIN SHOWERS
REMAIN OVER OUR AREA DUE TO OCCLUDED FRONT AND UPPER TROUGH AXIS...BUT
MOST OF THESE ARE RATHER LIGHT...WITH A FEW MODERATE BURSTS.
BECAUSE THE HEAVIEST RAINFALL SHOULD BE EAST OF OUR AREA...AND IR
SATELLITE IMAGERY SHOWS THE COLDEST/TALLEST CLOUD TOPS NOW
NORTH/EAST OF OUR AREA...WE HAVE CANCELLED THE FLASH FLOOD WATCH
FOR OUR ENTIRE AREA. WHILE RAIN SHOWERS WILL CONTINUE...RAIN RATES
WILL BE LOW ENOUGH TO PREVENT ANY FLASH FLOODING FROM OCCURRING.
THE LATEST 15Z 3KM HRRR SEEMS TO SHOW THIS IDEA AS WELL...HAVING
THE STRONGEST MODEL PREDICTED RADAR ECHOS EAST OF OUR AREA...AND
JUST LIGHT CELLULAR SHOWERS OVER OUR AREA THROUGH THE AFTN. WILL
INCLUDE A SLIGHT CHC FOR THUNDER IN CASE THERE IS A RUMBLE OR TWO
AROUND...BUT LIMITED INSTABILITY WILL PREVENT ANY STRONG/SEVERE
STORMS FROM OCCURRING.
STILL EXPECT MAX TEMPS TO REACH THE LOWER/MID 70S BY LATE
AFTERNOON IN MOST VALLEY AREAS...WITH POSSIBLY SOME UPPER 70S
ACROSS THE MID HUDSON VALLEY. MAX TEMPS SHOULD HOLD IN THE
LOWER/MID 60S ACROSS MUCH OF THE SOUTHERN ADIRONDACKS...AND SOME
HIGHER ELEVATIONS ACROSS WESTERN NEW ENGLAND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT-THU NT...AS THE MAIN OCCLUDED FRONT MOVES PAST...THE THREAT
FOR SHOWERS WILL GRADUALLY DIMINISH THIS EVENING FROM SW TO NE.
HOWEVER...THE COMBINATION OF COOL AIR ALOFT...CYCLONIC FLOW...AND
WEAK PIECES OF ENERGY POTENTIALLY ROTATING AROUND THE SOUTHERN
PERIPHERY OF THE CLOSED LOW NORTH OF THE GREAT LAKES SHOULD PROMOTE
THE CHANCES FOR SHOWERS ACROSS THE SOUTHERN ADIRONDACKS...AND
OCCASIONALLY INTO THE MOHAWK VALLEY AND LAKE GEORGE/SARATOGA REGIONS
AND SOUTHERN VT...WITH MORE LIMITED ACTIVITY EXPECTED FURTHER SOUTH
AND EAST WHERE MORE LOW LEVEL DOWNSLOPING AND SLIGHTLY WARMER TEMPS
ALOFT WILL REMAIN. SO...WILL KEEP CHC POPS FOR NORTHERN AREAS...WITH
SLIGHT CHC POPS OR LESS FURTHER SOUTH. TEMPS WILL FALL INTO THE
UPPER 40S TO MID 50S TONIGHT. THU MAX TEMPS SHOULD REACH 70-75 IN
MOST VALLEYS...BUT ONLY REACH THE 60S ACROSS MOST HIGHER ELEVATION
AREAS. LOWS THURSDAY NIGHT WILL BE IN THE MID 40S TO MID 50S.
ON FRIDAY THE COLD POOL WILL PERSIST WITH A GOOD CHANCE FOR SHOWERS
OVER THE ADIRONDACKS...WITH SLIGHT CHANCE OR LESS ELSEWHERE. HIGHS
WILL BE IN THE 60S OVER THE HIGHER ELEVATIONS...AND 70 TO 75 IN THE
VALLEYS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE PERIOD STARTS OUT FRIDAY NIGHT WITH AN UPPER LEVEL CLOSED LOW
LIFTING NORTHWARD THROUGH QUEBEC...AS CYCLONIC FLOW REGIME BECOMES
MORE NEUTRAL ACROSS OUR REGION. STILL RELATIVELY FAST FLOW ALOFT
INTO SATURDAY...WITH A POSSIBLE DISTURBANCE QUICKLY APPROACHING FROM
THE GREAT LAKES. MOST OF THE DAY LOOKS DRY WITH INCREASING AFTERNOON
CLOUDS. WILL INCREASE POPS ACROSS THE REGION SATURDAY NIGHT INTO
SUNDAY...AS A SHORT WAVE TROUGH MOVES THROUGH. WILL ONLY MENTION
SLIGHT CHANCE OF THUNDER ON SUNDAY...AS FORECAST INSTABILITY LOOKS
RATHER LIMITED. TEMPERATURES CONTINUE BELOW NORMAL THROUGH THE
WEEKEND.
A NORTHWEST FLOW REGIME LOOKS TO SET UP IN WAKE OF SUNDAY/S TROUGH
PASSAGE...WITH A RIDGE BUILDING UPSTREAM OVER THE GREAT LAKES. THIS
PATTERN SHOULD KEEP OUR REGION DRY MONDAY AND TUESDAY. TEMPERATURES
SHOULD MODERATE BACK TO NORMAL WITH INCREASING SUNSHINE. ANOTHER
UPPER LEVEL LOW ADVANCING EASTWARD ACROSS THE MIDWEST AND OHIO
VALLEY BRINGS THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS FOR THE
MID WEEK PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
GENERALLY MVFR TO IFR CONDITIONS...ESP FOR CIGS...WILL PREVAIL
THROUGH AROUND 20Z-22Z/WED. THEREAFTER...CONDITIONS SHOULD GRADUALLY
IMPROVE TO VFR.
AREAS OF SHOWERS/DRIZZLE WILL MIGRATE ACROSS THE TAF SITES AT TIMES
THROUGH LATE AFTERNOON...AS A LOW PRESSURE SYSTEM TRACKS EAST OF THE
REGION ACROSS NEW ENGLAND.
WINDS WILL BECOME NORTH TO NORTHEAST EARLY THIS AFTERNOON AT 5-10
KT...WITH SOME GUSTS OF 15-20 KT POSSIBLE AT KPSF. WINDS WILL THEN
BACK INTO THE WEST/NORTHWEST AT 5-10 KT LATER THIS AFTERNOON INTO
TONIGHT...THEN MAY BACK SLIGHTLY INTO THE WEST BY MID MORNING ON THU
AT 8-12 KT...WITH SOME GUSTS OF 15-20 POSSIBLE TOWARD OR AFTER
18Z/THU.
OUTLOOK...
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
FRIDAY TO SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
SUNDAY NIGHT TO MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
WET FLAG CONDITIONS ACROSS THE REGION THROUGH TODAY...
THE COMBINATION OF A LOW PRESSURE SYSTEM LOCATED NORTH OF THE GREAT
LAKES...AND A SECONDARY LOW DEVELOPING ALONG THE NEW JERSEY
COAST...WILL BRING A WIDESPREAD SOAKING RAINFALL TO THE REGION
THROUGH EARLY AFTERNOON. RAIN WILL TAPER TO SHOWERS AND SCATTERED
THUNDERSTORMS DURING THIS AFTERNOON. THE LOW WILL MOVE INTO NORTHERN
NEW ENGLAND BY THIS EVENING...BUT AN UPPER LEVEL LOW WILL LINGER
ACROSS SOUTHEAST CANADA...KEEPING SOMEWHAT COOL AND UNSETTLED
CONDITIONS THROUGH THE END OF THE WEEK.
RAIN...HEAVY AT TIMES...WILL FALL ACROSS THE REGION THROUGH AROUND
MIDDAY AS A BAND OF RAIN ASSOCIATED WITH A FRONTAL BOUNDARY CROSSES
THE REGION FROM WEST TO EAST. TOTAL RAINFALL AMOUNTS ASSOCIATED WITH
THIS BAND OF RAIN MAY REACH ONE TO TWO INCHES.
&&
.HYDROLOGY...
RAIN...HEAVY AT TIMES...WILL FALL ACROSS THE REGION THROUGH AROUND
MIDDAY AS A BAND OF RAIN ASSOCIATED WITH A FRONTAL BOUNDARY CROSSES
THE REGION FROM WEST TO EAST. TOTAL RAINFALL AMOUNTS ASSOCIATED WITH
THIS BAND OF RAIN MAY REACH ONE TO TWO INCHES AND CAUSE LOCALIZED
URBAN AND SMALL STREAM FLOODING. HOWEVER...AN AREA OF TORRENTIAL
RAIN WITH RAINFALL RATES OF ONE TO TWO INCHES PER HOUR THAT WAS OVER
LONG ISLAND AS OF 400 AM...WILL LIKELY PASS TO THE SOUTH AND EAST OF
THE FLASH FLOOD WATCH AREA THIS MORNING. AS A RESULT...THE THREAT OF
FLASH FLOODING WILL BE REDUCED IF THIS AREA OF TORRENTIAL RAIN
REMAINS TO THE SOUTH AND EAST OF THE FORECAST AREA. WAS NOT
CONFIDENT ENOUGH EARLY THIS MORNING TO DROP ANY PORTION OF THE FLASH
FLOOD WATCH AREA...BUT IF THE CURRENT RADAR TRENDS CONTINUE...THEN
PORTIONS OR ALL OF THE FLASH FLOOD WATCH MAY NEED TO BE CANCELLED
EARLY. THE ONLY OTHER FLOODING THREAT THAT WILL NEED TO BE MONITORED
IS THE POTENTIAL FOR ADDITIONAL CONVECTION WITH HIGH RAINFALL RATES
TO FORM THIS AFTERNOON ALONG AND BEHIND THE FRONTAL BOUNDARY.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/GJM
NEAR TERM...FRUGIS/KL/GJM
SHORT TERM...GJM
LONG TERM...JPV
AVIATION...KL
FIRE WEATHER...GJM
HYDROLOGY...GJM
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
302 PM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE WITH WINDS BECOMING NE AT 11 KT ARND 21Z...THEN
DIMINISHING TO 8 KT BY 22Z.
JEE
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE OVER THE PLAINS IS SLOWLY BUILDING EAST WHILE A WEAK
SURFACE TROUGH SWINGS THROUGH NE IL THIS AFTN. KEEPING THE TAFS
DRY DESPITE THE MODELS TRYING TO SQUEEZE OUT A LITTLE PRECIP. A
LAKE BREEZE IS EXPECTED AND STILL THINKING IT WILL TURN WINDS NE
ARND 11 KT AT ORD AND MDW AT 21Z. WINDS WILL BE NNE AT GYY. WINDS
WILL DIMINISH TO ARND 5 KT BY EARLY EVENING. EASTERLY WINDS WILL
SLOWLY PUSH WEST REACHING RFD THIS EVENING BUT THEY WILL BE ARND
5 KT. SKIES REMAIN VFR AND WINDS REMAIN LIGHT BTWN NORTH AND EAST
THROUGH THE REST OF THE PERIOD.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH FRIDAY...VFR.
FRIDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR BUT WITH PERIODIC
CHANCES FOR TSRA.
BMD
&&
.MARINE...
146 PM CDT
COLD FRONT WAS PUSHING SOUTH ACROSS SOUTHERN LAKE MICHIGAN THIS
AFTERNOON...AND SHOULD CLEAR THE SOUTH END THIS EVENING. MODEST
NORTH WINDS BEHIND THE FRONT WITH GUSTS 20-25 KT ON THE NORTHERN
QUARTER OR SO AT THIS TIME...IN TIGHTER GRADIENT IN THE WAKE OF LOW
PRESSURE MOVING AWAY OVER SOUTHWESTERN QUEBEC. WINDS ARE EXPECTED TO
DIMINISH TONIGHT HOWEVER...AS SURFACE HIGH PRESSURE RIDGE WEST OF
THE MISSISSIPPI MOVES EAST. QUIET MARINE WEATHER WILL BE THE RULE
THURSDAY INTO FRIDAY AS THE RIDGE MOVES ACROSS THE LAKE...AND LIGHT
SOUTH-SOUTHWEST RETURN FLOW SETS UP WEST OF THE RIDGE AXIS.
AREA OF LOW PRESSURE IS FORECAST TO DEVELOP ACROSS THE MID-MISSOURI
VALLEY FRIDAY INTO FRIDAY NIGHT...AND WILL LIFT NORTHEAST TOWARD THE
NORTHERN/WESTERN GREAT LAKES REGION THROUGH SATURDAY. SEVERAL DETAIL
DIFFERENCES EXIST IN VARIOUS MODEL SOLUTIONS OF THE TRACK OF THIS
LOW HOWEVER...RESULTING IN LOWER CONFIDENCE IN DETAILS OF THE WIND
FORECAST OVER THE WEEKEND. OVERALL HOWEVER...IT APPEARS THAT A
PERIOD OF SOUTH-SOUTHWEST WINDS WILL DEVELOP FRIDAY-FRIDAY NIGHT...
WITH WINDS EVENTUALLY BECOMING NORTHERLY SUNDAY ONWARD. SOME
POTENTIAL FOR WINDS AS HIGH AS 20-25 KT DURING THESE PERIODS...
THOUGH AGAIN LOWER CONFIDENCE IN THOSE SPEEDS GIVEN MODEL
DIFFERENCES WITH HANDLING OF THE LOW.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
148 PM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE BREEZE WITH WINDS BECOMING NE ARND 11 KT IN THE MID AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE OVER THE PLAINS IS SLOWLY BUILDING EAST WHILE A WEAK
SURFACE TROUGH SWINGS THROUGH NE IL THIS AFTN. KEEPING THE TAFS
DRY DESPITE THE MODELS TRYING TO SQUEEZE OUT A LITTLE PRECIP. A
LAKE BREEZE IS EXPECTED AND STILL THINKING IT WILL TURN WINDS NE
ARND 11 KT AT ORD AND MDW AT 21Z. WINDS WILL BE NNE AT GYY. WINDS
WILL DIMINISH TO ARND 5 KT BY EARLY EVENING. EASTERLY WINDS WILL
SLOWLY PUSH WEST REACHING RFD THIS EVENING BUT THEY WILL BE ARND
5 KT. SKIES REMAIN VFR AND WINDS REMAIN LIGHT BTWN NORTH AND EAST
THROUGH THE REST OF THE PERIOD.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH FRIDAY...VFR.
FRIDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR BUT WITH PERIODIC
CHANCES FOR TSRA.
BMD
&&
.MARINE...
146 PM CDT
COLD FRONT WAS PUSHING SOUTH ACROSS SOUTHERN LAKE MICHIGAN THIS
AFTERNOON...AND SHOULD CLEAR THE SOUTH END THIS EVENING. MODEST
NORTH WINDS BEHIND THE FRONT WITH GUSTS 20-25 KT ON THE NORTHERN
QUARTER OR SO AT THIS TIME...IN TIGHTER GRADIENT IN THE WAKE OF LOW
PRESSURE MOVING AWAY OVER SOUTHWESTERN QUEBEC. WINDS ARE EXPECTED TO
DIMINISH TONIGHT HOWEVER...AS SURFACE HIGH PRESSURE RIDGE WEST OF
THE MISSISSIPPI MOVES EAST. QUIET MARINE WEATHER WILL BE THE RULE
THURSDAY INTO FRIDAY AS THE RIDGE MOVES ACROSS THE LAKE...AND LIGHT
SOUTH-SOUTHWEST RETURN FLOW SETS UP WEST OF THE RIDGE AXIS.
AREA OF LOW PRESSURE IS FORECAST TO DEVELOP ACROSS THE MID-MISSOURI
VALLEY FRIDAY INTO FRIDAY NIGHT...AND WILL LIFT NORTHEAST TOWARD THE
NORTHERN/WESTERN GREAT LAKES REGION THROUGH SATURDAY. SEVERAL DETAIL
DIFFERENCES EXIST IN VARIOUS MODEL SOLUTIONS OF THE TRACK OF THIS
LOW HOWEVER...RESULTING IN LOWER CONFIDENCE IN DETAILS OF THE WIND
FORECAST OVER THE WEEKEND. OVERALL HOWEVER...IT APPEARS THAT A
PERIOD OF SOUTH-SOUTHWEST WINDS WILL DEVELOP FRIDAY-FRIDAY NIGHT...
WITH WINDS EVENTUALLY BECOMING NORTHERLY SUNDAY ONWARD. SOME
POTENTIAL FOR WINDS AS HIGH AS 20-25 KT DURING THESE PERIODS...
THOUGH AGAIN LOWER CONFIDENCE IN THOSE SPEEDS GIVEN MODEL
DIFFERENCES WITH HANDLING OF THE LOW.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1228 PM CDT WED AUG 13 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CHALLENGES THIS MORNING INCLUDE THE BACK DOOR FRONT
COMING IN OFF THE LAKE LATER THIS AFTERNOON OR EARLY THIS EVENING
AND ASSOCIATED PRECIP CHANCES...FOLLOWED BY PRECIP CHANCES WITH
TRICKY SYSTEM THIS WEEKEND.
SURFACE ANALYSIS EARLY THIS MORNING SHOWS A TYPICAL WEAK SUMMER COLD
FRONT EXTENDING FROM FAR NORTHERN LOWER MICHIGAN WEST INTO NORTHERN
WISCONSIN WHERE IT BECOMES PRETTY ILL DEFINED. THE FRONT WILL SAG
SOUTHWARD TODAY...BUT SHOULD BE AIDED BY AND ACCELERATE SOUTHWARD
DOWN LAKE MICHIGAN THIS AFTERNOON AND EVENING. WHILE THE LAKE HAS
WARMED...AIR TEMPS IN THE MARINE LAYER OVER THE LAKE ARE IN THE LOW
TO MID 60S SO CONTRASTED WITH THE 80 DEGREE TEMPS OVER LAND SHOULD
PROVIDE A DECENT PUSH OF COLDER AIR AS THE COLD FRONT BECOMES
ENHANCED BY THE LAKE. HAVE LEANED SLIGHTLY TOWARD THE FASTER
SOLUTIONS OFFERED UP BY THE RAP AND 06Z NAM WHICH SUGGEST WE COULD
SEE FALLING TEMPS INTO FAR NE IL BY 21Z...SPREADING ACROSS THE METRO
AREA BY 00Z WITH THE MOST DRAMATIC COOLING (10F+ DROP) NEAR THE LAKE
WITH LESS OF A DROP EXPECTED INLAND. MANY MODELS DO BREAK OUT LIGHT
QPF...LIKELY PARTIALLY ASSOCIATED WITH THIS LAKE ENHANCED FRONT THIS
AFTERNOON...BUT FORECAST SOUNDINGS FROM THE MODELS THAT SHOW QPF ALL
SHOW THERMODYNAMIC PROFILES THAT ARE EXCEPTIONALLY UNFAVORABLE FOR
PRECIPITATION WITH INVERSION/ISOTHERMAL LAYER BETWEEN 700-600MB WITH
DRY AIR ABOVE THAT. GIVEN THE LACK OF LARGE SCALE FORCING AND
UNFAVORABLE THERMODYNAMICS HAVE ONLY INTRODUCED SLIGHT CHANCE POPS
FOR LIGHT SHOWERS THIS AFTERNOON OVER FAR NE IL WHERE MET GUIDANCE
HAS POPS OVER 40 PERCENT.
WEATHER LOOKS QUIET THURSDAY AND MUCH OF FRIDAY WITH HIGH PRESSURE
TRACKING ACROSS THE REGION...ALLOWING FOR LAKE BREEZE AND SLIGHTLY
BELOW AVERAGE TEMPS THURSDAY FOLLOWED BY LESS (IF ANY) LAKE COOLING
FRIDAY WITH MODERATING TEMPS ON DEVELOPING SOUTHERLY WINDS.
VIGOROUS SHORTWAVE OVER DESSERT SOUTHWEST WILL RIDE THE SUBTROPICAL
JET AROUND THE PERIPHERY OF THE UPPER RIDGE AND EMERGE OUT ONTO THE
HIGH PLAINS THURSDAY NIGHT INTO FRIDAY. GFS PHASES THIS WAVE WITH
DEPARTING NORTHERN STREAM SHORTWAVE AND IS MUCH MORE PROGRESSIVE
WITH THE MOVEMENT OF THIS FEATURE ACROSS THE REGION. THE NAM AND
ECMWF KEEP THIS SHORTWAVE SEPARATE FROM THE NORTHERN STREAM AND
RESULT IN A MUCH SLOWER MEANDERING OF THIS FEATURE INTO THE AREA
THIS WEEKEND WITH GRADUALLY INCREASING CHANCES FOR AT LEAST
SCATTERED SHOWERS/STORMS. THE PROGRESSIVE GFS WOULD SUGGEST A WET
SATURDAY AND DRY SUNDAY...WHILE ECMWF HAS A MORE PROLONGED PERIOD OF
AT LEAST POTENTIAL SHOWER/TSTM ACTIVITY THROUGH THE WEEKEND INTO
EARLY NEXT WEEK. SUSPECT ECMWF SOLUTION WILL BE CLOSER TO WHAT
EVENTUALLY BECOMES REALITY...BUT CONFIDENCE IS LOW AND NECESSITATES
SEVERAL DAYS WITH CHANCES OF SHOWERS AND TSTMS OVER THE WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES AND HUMIDITY SHOULD CREEP UP BACK TO
MORE SEASONABLE LEVELS THIS WEEKEND INTO EARLY NEXT WEEK AS UPPER
TROUGH OVER THE GREAT LAKES THIS MORNING LIFTS OUT AND PATTERN
DEAMPLIFIES.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE BREEZE WITH WINDS BECOMING NE ARND 11 KT IN THE MID AFTN.
JEE
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE OVER THE PLAINS IS SLOWLY BUILDING EAST WHILE A WEAK
SURFACE TROUGH SWINGS THROUGH NE IL THIS AFTN. KEEPING THE TAFS
DRY DESPITE THE MODELS TRYING TO SQUEEZE OUT A LITTLE PRECIP. A
LAKE BREEZE IS EXPECTED AND STILL THINKING IT WILL TURN WINDS NE
ARND 11 KT AT ORD AND MDW AT 21Z. WINDS WILL BE NNE AT GYY. WINDS
WILL DIMINISH TO ARND 5 KT BY EARLY EVENING. EASTERLY WINDS WILL
SLOWLY PUSH WEST REACHING RFD THIS EVENING BUT THEY WILL BE ARND
5 KT. SKIES REMAIN VFR AND WINDS REMAIN LIGHT BTWN NORTH AND EAST
THROUGH THE REST OF THE PERIOD.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
JEE
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT THROUGH FRIDAY...VFR.
FRIDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR BUT WITH PERIODIC
CHANCES FOR TSRA.
BMD
&&
.MARINE...
300 AM CDT
CONDITIONS CONTINUE TO SLOWLY IMPROVE ACROSS LAKE MICHIGAN AS WINDS
AND WAVES DIMINISH BEHIND THE DEPARTING LOW SYSTEM CURRENTLY MOVING
ACROSS THE EASTERN LAKES. A SECONDARY TROUGH WILL WORK ITS WAY SOUTH
ACROSS LAKE MICHIGAN TODAY WITH WINDS PICKING UP SLIGHTLY OUT OF THE
NORTH...ESPECIALLY ACROSS THE NORTH HALF OF THE LAKE WHERE WIND
SPEEDS WILL INCREASE BACK INTO THE 15 TO 25 KT RANGE. HIGH PRESSURE
WILL MOVE ACROSS THE LAKE LATE THURSDAY INTO FRIDAY WITH WINDS THEN
TURNING BACK TO THE SOUTHWEST/SOUTH FRIDAY AND SATURDAY.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
1126 AM MDT WED AUG 13 2014
.SHORT TERM...(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 225 AM MDT WED AUG 13 2014
LATEST WV IMAGERY AND RAP ANALYSIS SHOW AMPLIFIED 594 DM RIDGE
CENTERED OVER THE SOUTHERN PLAINS EXTENDING NORTH ACROSS THE CENTRAL
PLAINS/CENTRAL ROCKIES INTO SOUTHERN CANADA. AT THE SURFACE THE LEE
TROUGH IS DEEPENING OVER EASTERN COLORADO WITH HIGH PRESSURE
BEGINNING TO SHIFT TOWARD EASTERN KANSAS.
TODAY-THURSDAY NIGHT...ANOTHER VERY WARM AND DRY DAY IS EXPECTED
TODAY AS H5 RIDGE CONTINUE TO DOMINATE PATTERN OVER THE CWA...AND
MAIN STORM TRACK REMAINS WELL OUTSIDE OUR AREA OF CONCERN. BY MIDDAY
THURSDAY THE NORTHERN EXTENT OF THE RIDGE WILL BEGIN TO FLATTEN IN
RESPONSE TO A SHORTWAVE TROUGH MOVING OUT OF THE FOUR CORNERS REGION
AND INTO THE NORTHERN PLAINS. WHILE INSTABILITY INCREASES...SOUNDING
SHOW HIGH TD DEPRESSIONS BELOW 500MB THROUGH AT LEAST EARLY THURSDAY
AFTERNOON...WHICH COULD LIMIT PRECIPITATION REACHING THE GROUND IN
ALL BUT THE STRONGEST UPDRAFTS UNTIL MID AFTERNOON. BETTER
LIFT/INSTABILITY SHOULD SUPPORT BETTER THUNDERSTORM COVERAGE BY LATE
THURSDAY AFTERNOON AND ESPECIALLY THURSDAY NIGHT...AND MODELS SHOW A
GOOD PRECIP SIGNAL DURING THESE PERIODS. I KEPT SLIGHT CHANCE POPS
IN PLACE MIDDAY THURSDAY...THOUGH CONFIDENCE WASNT HIGH FOR
INITIATION THAT EARLY AND TRENDED POPS UP BY THE EVENING OVERNIGHT
HOURS. BY THURSDAY NIGHT BETTER CAPE PROFILES AND INCREASING PWATS
WOULD SUPPORT THE POSSIBILITY OF LOCALIZED HEAVY RAIN...HOWEVER
THREAT IS UNCERTAIN AT THIS RANGE ESPECIALLY WITH BETTER STORM
MOTIONS. SHEER WILL BE DECENT...HOWEVER CAPE IS MARGINAL...SO
ELEVATED SEVERE THREAT IS UNCERTAIN.
FRIDAY-FRIDAY NIGHT...RIDGE REMAINS IN PLACE OVER THE SOUTHERN
PLAINS WITH NORTHWEST FLOW ALLOWING WEAK MID LEVEL VORTICITY TO
ROTATE THROUGH THE NORTHERN PLAINS. AS PRECIP COMES TO AN END WITH
DEPARTING SHORTWAVE ONLY WEAK FORCING WILL BE IN PLACE. MODERATE
INSTABILITY WILL BUILD BACK OVER THE CWA WITH DAYTIME HEATING...AND
THERE CONTINUES TO BE A WEAK PRECIP SIGNAL BETWEEN THE GFS AND
ECMWF...SO WHILE CONFIDENCE IS NOT HIGH WE WILL SEE MUCH
THUNDERSTORM ACTIVITY SLIGHT CHANCE POPS STILL SEEM REASONABLE FOR
NOW.
REGARDING TEMPS...GUIDANCE CONTINUES TO SHOW GOOD WAA ALONG EASTERN
SIDE OF LEE TROUGH THROUGH THURSDAY. LOW TO MID 90S FOR MOST
LOCATIONS TODAY AND THURSDAY SEEM REASONABLE...THOUGH INCREASING
CLOUD COVER COULD LIMIT WARMING SOME ON THURSDAY. FRIDAY TEMPS COULD
BE A BIT COOLER BEHIND TROUGH AND BUILDING NW FLOW...HOWEVER
GUIDANCE CONTINUES TO SHOW DECENT RECOVERY OF TEMPS ALOFT WITH LEE
TROUGH QUICKLY BUILDING BACK OVER EASTERN COLORADO. I USED CONSENSUS
FOR FRIDAY AS A BEST GUESS WHICH FAVORS SEASONAL TEMPS AROUND 90F.
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 225 AM MDT WED AUG 13 2014
AN UPPER LEVEL RIDGE WILL BE POSITIONED OVER THE SOUTHWEST PORTION
OF THE CONUS WITH WESTERLY/NORTHWESTERLY FLOW ALOFT ACROSS THE
CENTRAL HIGH PLAINS. MEDIUM RANGE GUIDANCE DISPLAYS SOME FAIRLY
SIGNIFICANT DIFFERENCES WITH TIMING AND AMPLITUDE OF THE A SHORTWAVE
TROUGH THAT WILL PASS THROUGH ON MONDAY. THE GFS IS THE MOST
AMPLIFIED AND HAS THE STRONGEST FORCING BUT SEVERAL GFS ENSEMBLE
MEMBERS DISPLAY LESS AMPLITUDE SIMILAR TO THE DETERMINISTIC ECMWF.
THIS LEADS TO UNCERTAINTY WITH REGARDS TO AMOUNT OF CONVECTION.
ASIDE FROM THIS SHORTWAVE THE PATTERN REMAINS FAIRLY BENIGN WITH
NEAR OR SLIGHTLY ABOVE NORMAL TEMPERATURES THROUGH THE ENTIRE
PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1123 AM MDT WED AUG 13 2014
VFR EXPECTED AT BOTH KGLD AND KMCK THROUGH THE TAF PERIOD. HIGH
PRESSURE ALOFT WILL SUPPRESS THUNDERSTORM CHANCES TODAY. LOW
PRESSURE AT THE SURFACE IN EASTERN COLORADO WILL RESULT IN BREEZY
SOUTHEASTERLY WINDS THROUGH SUNSET TONIGHT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...024
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
438 PM EDT WED AUG 13 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 331 PM EDT WED AUG 13 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NNW FLOW ALF OVER
THE UPR LKS BETWEEN SHARP UPR TROF CENTERED NEAR JAMES BAY AND AN
UPR RDG OVER THE WRN PLAINS. THERE IS A SHRTWV EMBEDDED IN THIS FLOW
THAT IS DIVING THRU ERN LK SUP...BUT THE MID LVLS ARE SUFFICIENTLY
DRY/STABLE OVER THE UPR LKS PER THE 12Z INL/YPL RAOBS THAT THERE
HAVE BEEN NO SHOWERS. BUT THESE RAOBS ALL SHOW A GOOD DEAL OF LLVL
MSTR. WITH THE ONSET OF DAYTIME HEATING...A GOOD DEAL OF LO CLD
DVLPD...ESPECIALLY OVER THE W AND NCENTRAL WHERE THE SFC-H925 NLY
FLOW UPSLOPES OFF LK SUP. THE STEADY/GUSTY N WIND IS CAUSING HIER
WAVES/DANGEROUS SWIMMING CONDITIONS IN THE LK SUP BEACHES E OF THE
KEWEENAW. CLOSER TO HI PRES OVER FAR NW ONTARIO WHERE THE LLVL
AIRMASS IS MUCH DRIER AS SHOWN ON THE 12Z CHURCHILL MANITOBA
RAOB...THERE ARE FEWER CLDS AND WINDS ARE LGT.
MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD TRENDS THIS AFTN AND
THEN TEMPS TNGT AND THU AS THE DRY HI PRES IN ONTARIO WL DOMINATE.
LATE THIS AFTN/TNGT...UNDER CONFLUENT NW FLOW ALF/DEEP LYR QVECTOR
DVGC...SFC HI PRES OVER FAR NW ONTARIO IS PROGGED TO SINK OVER WRN
LK SUP BY 12Z THU. WITH LOSS OF DAYTIME HEATING AND LLVL DRY ADVCTN
IN THE LLVL NLY FLOW AHEAD OF THE SFC HI PRES...EXPECT ANY LINGERING
CLDS TO DISSIPATE THIS EVNG AND GIVE TO MOCLR SKIES OVERNGT. THE
ARRIVAL OF DRIER AIR FM THE N...WITH PWAT SINKING AS LO AS 0.33 INCH
OR 30-35 PCT OF NORMAL...FAVORS A LARGE DIURNAL DROP OF TEMP...
ESPECIALLY OVER THE W WHERE THE WINDS WL BE LIGHTER CLOSER TO THE
INCOMING SFC RDG AXIS. WL MAINTAIN FCST LO TEMPS IN THE 30S AT THE
COLDER INTERIOR LOCATIONS IN THIS AREA. STEADY N WIND OVER THE E
UNDER THE SHARPER PRES GRADIENT BTWN THE RDG AND LO PRES OVER QUEBEC
WL TEND TO RESTRICT THE DIURNAL TEMP DROP THERE.
THU...SFC HI PRES AXIS IS FCST TO SHIFT FM NCENTRAL UPR MI THRU LK
MI. WITH CORE OF DRY AIR OVHD...EXPECT NOTHING MORE THAN SOME
DIURNAL CU OVER THE INTERIOR. H85 TEMPS ARE FCST TO PEAK BTWN ABOUT
8C OVER THE E TO 12C OVER THE W. MIXING TO H8 ON FCST SDNGS
INDICATES MAX TEMPS WL PEAK NEAR 75 OVER THE INTERIOR W AND
SCENTRAL. WITH A STEADY NW WIND OFF LK SUP OVER THE E THAT WL
MAINTAIN HIER WAVES/SWIM RISK...TEMPS WL HAVE A HARD TIME RISING
OVER 70 EXCEPT CLOSER TO LK MI. AFTN MIXING WL CAUSE MIN RH TO
BOTTOM OUT AS LO AS 30-35 PCT OVER MUCH OF THE INTERIOR. DESPITE THE
SOMEWHAT COOLER TEMPS OVER THE E...STRONGER WINDS WL AGGRAVATE FIRE
WX CONDITIONS THERE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 436 PM EDT WED AUG 13 2014
THU NIGHT...WITH THE SFC RIDGE OVER THE AREA...EXPECT GOOD
RADIATIONAL COOLING CONDITIONS UNTIL LATE OVER THE WEST WHEN
MOISTURE BEGINS TO INCREASE. THE LOWER MINS...INTO THE LOWER 40S
INLAND...SHOULD PREVAIL ACROSS THE EAST WHERE PWAT VALUES REMAIN
BELOW 0.5 INCH.
FRI...WSW LOW LEVEL FLOW AND MOISTURE ADVECTION INCREASE AS THE HIGH
SHIFTS TOWARD THE OHIO VALLEY. EVEN THROUGH MLCAPE VALUES MAY CLIMB
INTO THE 400-800 J/KG RANGE AND PWAT RISES TO 1.5 INCHES OVER THE
WEST...THE MODELS SUGGEST THAT THE MAIN FORCING FOR ANY SHRA/TSRA WILL
REMAIN TO THE WEST AS A SHRTWV MOVES FROM SE FROM THE DAKOTAS.
SLIGHT OR LOWER END CHANCE POPS WERE STILL INCLUDED OVER THE WEST
GIVEN THE INSTABILITY AND POTENTIAL FOR EITHER A WEAK SHRTWV OR BAND
OF 300-310K ISENTROPIC LIFT TO SET OFF SOME SCT/ISOLD SHRA/TSRA.
FRI NIGHT INTO SAT...EXPECT A GREATER CHANCE FOR PCPN AS MODELS WERE
IN GOOD AGREEMENT IN BRINGING A SHORTWAVE TROUGH WITH MODERATE
700-300 MB QVECTOR CONV AND AN ASSOCIATED COLD FRONT THROUGH THE NRN
GREAT LAKES. BY SAT AFTERNOON IN THE WAKE OF THE FRONT...PCPN
CHANCES SHOULD DIMINISH ACROSS THE NORTH WITH COOLER MORE STABLE AIR
MOVING IN ON LOW LEVEL NRLY FLOW.
SUN-WED...MAINLY DRY WEATHER THROUGH MON IS EXPECTED WITH MID LEVEL
RIDGING AND A SFC RIDGE DOMINATING. THE GFS/GEM/ECMWF SUGGEST THAT A
SLOW MOVING SHRTWV AND SFC TROUGH WILL MOVE INTO THE WRN LAKES FROM
TUE INTO WED. ALTHOUGH CONFIDENCE IS LOW WITH THE POSITION/STRENGTH
OF THIS FEATURE...MDLS CONSENSUS OF INCREASING POPS AND TSRA
POTENTIAL SEEMS REASONABLE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 121 PM EDT WED AUG 13 2014
AS DRY HI PRES BUILDS INTO THE UPR LKS...ANY LINGERING LO CLDS/MVFR
CIGS WL DISSIPATE AND GIVE WAY TO VFR CONDITIONS BY 20Z AT ALL 3 TAF
SITES. GUSTY N WINDS THIS AFTN WL DIMINISH THIS EVNG WITH THE LOSS OF
DAYTIME HEATING AND AS THE PRES GRADIENT WEAKENS WITH THE CLOSER
APRCH OF THE SFC HI.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 331 PM EDT WED AUG 13 2014
UNDER A SHARP PRES GRADIENT BETWEEN HI PRES SINKING SOUTH THRU FAR
WESTERN ONTARIO AND SLOW MOVING LO PRES IN WESTERN QUEBEC...EXPECT N
TO NW WINDS AS HI AS 20-25 KTS OVER THE E HALF OF LAKE SUPERIOR THRU
THU. AS THE ONTARIO HI MOVES OVER THE UPPER LAKES LATER ON THU...
EXPECT WINDS TO DIMINISH UNDER 15 KTS BY FRI. THESE LIGHTER WINDS
WILL PERSIST INTO SAT...BUT THE SHARPENING PRES GRADIENT BEHIND A
COLD FRONTAL PASSAGE WILL CAUSE N-NE WINDS TO INCREASE UP TO 20 KTS
ON SAT NIGHT INTO SUN. AS THE HI PRES TRAILING THE FRONT SLIDES TO
THE SE EARLY NEXT WEEK...WINDS WILL SHIFT TO THE SSE UP TO 20 KTS ON
MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ005-
006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLB
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
331 PM EDT WED AUG 13 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 331 PM EDT WED AUG 13 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NNW FLOW ALF OVER
THE UPR LKS BETWEEN SHARP UPR TROF CENTERED NEAR JAMES BAY AND AN
UPR RDG OVER THE WRN PLAINS. THERE IS A SHRTWV EMBEDDED IN THIS FLOW
THAT IS DIVING THRU ERN LK SUP...BUT THE MID LVLS ARE SUFFICIENTLY
DRY/STABLE OVER THE UPR LKS PER THE 12Z INL/YPL RAOBS THAT THERE
HAVE BEEN NO SHOWERS. BUT THESE RAOBS ALL SHOW A GOOD DEAL OF LLVL
MSTR. WITH THE ONSET OF DAYTIME HEATING...A GOOD DEAL OF LO CLD
DVLPD...ESPECIALLY OVER THE W AND NCENTRAL WHERE THE SFC-H925 NLY
FLOW UPSLOPES OFF LK SUP. THE STEADY/GUSTY N WIND IS CAUSING HIER
WAVES/DANGEROUS SWIMMING CONDITIONS IN THE LK SUP BEACHES E OF THE
KEWEENAW. CLOSER TO HI PRES OVER FAR NW ONTARIO WHERE THE LLVL
AIRMASS IS MUCH DRIER AS SHOWN ON THE 12Z CHURCHILL MANITOBA
RAOB...THERE ARE FEWER CLDS AND WINDS ARE LGT.
MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD TRENDS THIS AFTN AND
THEN TEMPS TNGT AND THU AS THE DRY HI PRES IN ONTARIO WL DOMINATE.
LATE THIS AFTN/TNGT...UNDER CONFLUENT NW FLOW ALF/DEEP LYR QVECTOR
DVGC...SFC HI PRES OVER FAR NW ONTARIO IS PROGGED TO SINK OVER WRN
LK SUP BY 12Z THU. WITH LOSS OF DAYTIME HEATING AND LLVL DRY ADVCTN
IN THE LLVL NLY FLOW AHEAD OF THE SFC HI PRES...EXPECT ANY LINGERING
CLDS TO DISSIPATE THIS EVNG AND GIVE TO MOCLR SKIES OVERNGT. THE
ARRIVAL OF DRIER AIR FM THE N...WITH PWAT SINKING AS LO AS 0.33 INCH
OR 30-35 PCT OF NORMAL...FAVORS A LARGE DIURNAL DROP OF TEMP...
ESPECIALLY OVER THE W WHERE THE WINDS WL BE LIGHTER CLOSER TO THE
INCOMING SFC RDG AXIS. WL MAINTAIN FCST LO TEMPS IN THE 30S AT THE
COLDER INTERIOR LOCATIONS IN THIS AREA. STEADY N WIND OVER THE E
UNDER THE SHARPER PRES GRADIENT BTWN THE RDG AND LO PRES OVER QUEBEC
WL TEND TO RESTRICT THE DIURNAL TEMP DROP THERE.
THU...SFC HI PRES AXIS IS FCST TO SHIFT FM NCENTRAL UPR MI THRU LK
MI. WITH CORE OF DRY AIR OVHD...EXPECT NOTHING MORE THAN SOME
DIURNAL CU OVER THE INTERIOR. H85 TEMPS ARE FCST TO PEAK BTWN ABOUT
8C OVER THE E TO 12C OVER THE W. MIXING TO H8 ON FCST SDNGS
INDICATES MAX TEMPS WL PEAK NEAR 75 OVER THE INTERIOR W AND
SCENTRAL. WITH A STEADY NW WIND OFF LK SUP OVER THE E THAT WL
MAINTAIN HIER WAVES/SWIM RISK...TEMPS WL HAVE A HARD TIME RISING
OVER 70 EXCEPT CLOSER TO LK MI. AFTN MIXING WL CAUSE MIN RH TO
BOTTOM OUT AS LO AS 30-35 PCT OVER MUCH OF THE INTERIOR. DESPITE THE
SOMEWHAT COOLER TEMPS OVER THE E...STRONGER WINDS WL AGGRAVATE FIRE
WX CONDITIONS THERE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 335 AM EDT WED AUG 13 2014
THE UPPER LOW CURRENTLY JUST E OF THE CWA WILL DEEPEN WHILE MOVING
INTO SERN QUEBEC BY 12Z THU...AND WILL REMAIN NEARLY STATIONARY
THROUGH AT LEAST FRI /MODELS DISAGREE ON LOCATION AFTER FRIDAY/.
MEANWHILE...THE WELL DEFINED UPPER RIDGE CURRENTLY OVER THE ROCKIES
AND INTO WRN CANADA WILL SHIFT SLIGHTLY E BY THU MORNING...WITH A
PORTION OF THAT RIDGE EXTENDING FROM THE NRN PLAINS TO HUDSON BAY.
BETWEEN THESE TWO SYSTEMS...A SFC RIDGE WILL BE IN PLACE THU AND THU
NIGHT. NO PRECIP IS EXPECTED THU AND THU NIGHT. IT DOES LOOK LIKE WE
WILL MIX INTO A VERY DRY AIRMASS ON THU /1000-500MB RH AROUND 20
PERCENT/...WHICH WILL ALLOW MIN RH VALUES NEAR 30 PERCENT OVER ERN
UPPER MI AND IN THE LOW TO MID 30 PERCENT RANGE ELSEWHERE. WINDS
WILL BE GUSTY OVER THE ERN CWA...WITH GUSTS TO 20KTS OVER ERN UPPER
MI IN THE AFTERNOON. FIRE WX WILL BE MORE OF A CONCERN OVER ERN
UPPER MI.
PRECIP CHANCES INCREASE FRI INTO SAT AS A SHORTWAVE TROUGH MOVES
OVER THE AREA THROUGH THE WEAKENING UPPER RIDGE FRI AND A STRONG
SHORTWAVE TROUGH AND SFC COLD FRONT MOVE THROUGH LATE FRI NIGHT INTO
SAT. WITH MOISTURE INCREASING DURING THIS TIME AND BETTER FORCING
WITH THE SECOND FEATURE...HAVE GREATEST POPS THEN.
UNCERTAINTY INCREASES THROUGH THE REST OF THE FORECAST PERIOD...BUT
MODELS DO HINT THAT HIGH PRESSURE WILL BE IN CONTROL SUN INTO
MON...LEAVING THE AREA DRY. PRECIP MAY TRY TO MAKE A REAPPEARANCE
LATE MON INTO TUE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 121 PM EDT WED AUG 13 2014
AS DRY HI PRES BUILDS INTO THE UPR LKS...ANY LINGERING LO CLDS/MVFR
CIGS WL DISSIPATE AND GIVE WAY TO VFR CONDITIONS BY 20Z AT ALL 3 TAF
SITES. GUSTY N WINDS THIS AFTN WL DIMINISH THIS EVNG WITH THE LOSS OF
DAYTIME HEATING AND AS THE PRES GRADIENT WEAKENS WITH THE CLOSER
APRCH OF THE SFC HI.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 331 PM EDT WED AUG 13 2014
UNDER A SHARP PRES GRADIENT BETWEEN HI PRES SINKING SOUTH THRU FAR
WESTERN ONTARIO AND SLOW MOVING LO PRES IN WESTERN QUEBEC...EXPECT N
TO NW WINDS AS HI AS 20-25 KTS OVER THE E HALF OF LAKE SUPERIOR THRU
THU. AS THE ONTARIO HI MOVES OVER THE UPPER LAKES LATER ON THU...
EXPECT WINDS TO DIMINISH UNDER 15 KTS BY FRI. THESE LIGHTER WINDS
WILL PERSIST INTO SAT...BUT THE SHARPENING PRES GRADIENT BEHIND A
COLD FRONTAL PASSAGE WILL CAUSE N-NE WINDS TO INCREASE UP TO 20 KTS
ON SAT NIGHT INTO SUN. AS THE HI PRES TRAILING THE FRONT SLIDES TO
THE SE EARLY NEXT WEEK...WINDS WILL SHIFT TO THE SSE UP TO 20 KTS ON
MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ005-
006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS BILLINGS MT
237 PM MDT WED AUG 13 2014
.SHORT TERM...VALID FOR THU AND FRI...
FAIRLY ACTIVE WEATHER COMING IN THE SHORT TERM PERIOD.
MID LEVEL SHORTWAVE IS ROUNDING THE RIDGE AND MOVING INTO EASTERN
MT THIS AFTN. SHOWERS WITHOUT TSTMS HAVE BEEN DEVELOPING FROM
ROSEBUD INTO CUSTER AND POWDER RIVER COUNTIES FOR THE PAST COUPLE
HOURS. LATEST ANALYSIS SUGGESTS 1500-2500 J/KG OF SBCAPE NEAR THE
DAKOTAS BORDER...WITH DIMINISHING CIN...SO WOULD ANTICIPATE SOME
STRONGER CELLS TO POP UP OVER THE NEXT FEW HOURS AS ASCENT REACHES
OUR FAR EAST. BULK SHEAR REMAINS 25 KTS OR LESS SO DO NOT SEE A
SIGNIFICANT SEVERE THREAT...THOUGH WILL HAVE TO WATCH ANY STRONGER
CELLS FOR SMALL HAIL AND HEAVY RAIN THROUGH MAYBE 02Z OR SO. HRRR
HAS CONSISTENTLY SHOWN CELLS DEVELOPING IN FALLON/CARTER COUNTIES
BY 22-23Z.
NEXT FEATURE OF INTEREST IS MONSOONAL ENERGY LIFTING THROUGH THE
FOUR CORNERS AREA EMBEDDED IN A VERY MOIST SOUTHERLY FLOW ALOFT.
PACIFIC NW LOW IS MOVING VERY SLOWLY...SO TRAJECTORY OF MONSOON
WAVE TAKES IT INTO OUR CWA BY EARLY TOMORROW...RATHER THAN BEING
DEFLECTED TO THE EAST. HRRR RUNS HAVE ALSO BEEN CONSISTENT WITH
SHOWING A LARGE AREA OF SHOWERS APPROACHING OUR AREA FROM THE
SOUTH LATER TONIGHT. GIVEN THE FORCING AND MOISTURE ANTICIPATED
WITH THIS WEAK MONSOON ENERGY...HAVE RAISED POPS ACROSS OUR SOUTH
AND SOUTHEAST BEGINNING EARLY TOMORROW MORNING AND LASTING THROUGH
THE EVENING IN OUR SOUTHEAST...AS ALL MODELS SHOW A MID LEVEL
CIRCULATION MOVING SLOWLY THROUGH SOUTHEAST MT. MAIN IMPACT WITH
THIS SYSTEM WILL BE PCPN AND NOT SEVERE WX...AS SHOWERS ARE
EXPECTED TO BEGIN EARLY IN THE DAY AND SFC TEMPS WILL BE COOLER.
THERE WILL BE SOME LIGHTNING BUT DO NOT SEE A LARGE AMOUNT FOR THE
SAME REASONS. WILL KEEP LALS AT 3 FOR TOMORROW. IT COULD ACTUALLY
BE A BENEFICIAL DAY AS FAR AS FIRE WEATHER GOES.
FURTHER WEST...PACIFIC NW LOW WILL MOVE SLOWLY EAST BUT WILL STILL
BE OVER WA/OR TOMORROW AFTN. STRONGER UPPER DIFFLUENCE WILL BE
WEST OF US...AND TO OUR WEST WILL BE WHERE THE RISK OF STRONGER
STORMS WILL BE...BUT SHOULD BE ENOUGH MOISTURE AND INSTABILITY
FOR SCATTERED AFTN AND EVENING TSTMS EVEN AS MONSOON LOW BEGINS
TO SHIFT EAST.
LATEST MODEL TRENDS SUGGEST PACIFIC LOW WILL DRIFT SLIGHTLY NORTH
BY FRIDAY...SOMEWHERE NEAR EASTERN WA/NORTHERN ID BY LATE IN THE
DAY. AS A RESULT WE WILL BEGIN TO TAP INTO DRIER AIR FROM THE
NORTHERN GREAT BASIN...GFS SHOWS PWATS NEAR A HALF INCH IN PARK
COUNTY...AND STRONGER JET SUPPORT WILL EXIST IN NORTH CENTRAL MT.
WILL KEEP POPS AT SCATTERED BUT HAVE TAPERED THEM SLIGHTLY...IE
COVERAGE SHOULD BE LESS THAN ON THURSDAY. ALSO...MONSOONAL LOW
SHOULD BE IN THE DAKOTAS BY FRIDAY BUT MAY BE CLOSE ENOUGH TO
BRING WRAP AROUND SHOWERS/TSTMS TO OUR EAST. SOME MODEL
UNCERTAINTY IN THIS REGARD.
AS FOR TEMPERATURES...INCREASED CHANCES OF PCPN AND CLOUD COVER
WILL GIVE US A COOLER DAY TOMORROW...WITH HIGHS MAINLY IN THE 80S
TO LOWER 90S. IF SHOWERS PERSIST LONG ENOUGH SOME PARTS OF OUR
SOUTH OR SOUTHEAST MAY STRUGGLE TO GET OUT OF THE 70S. THESE AREAS
WILL REBOUND WITH THE DRIER AIR ON FRIDAY.
JKL
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
THE UPPER LOW IN THE PACIFIC NORTHWEST WILL BEGIN ITS MOVE TO THE
NORTHEAST ACROSS THE MONTANA/CANADA BORDER SATURDAY INTO SUNDAY.
ASSOCIATED SURFACE TROUGH WILL DEVELOP ACROSS EASTERN MT ON
SATURDAY WITH LOW LEVEL SOUTHEAST FLOW AHEAD OF IT. LOOKS LIKE
GOOD SHEAR AND INSTABILITY FOR THE BEST CHANCE FOR STORMS IN THIS
AREA OF SOUTHEAST MT FOR SATURDAY WITH ISOLATED POTENTIAL
ELSEWHERE. UPPER LEVEL CYCLONIC FLOW REMAINS FOR SUNDAY AS THE
SYSTEM MAKES ONLY SLOW PROGRESS EAST...SO CANT RULE OUT SOME
INSTABILTIY SHOWERS/STORMS PERSISTING. A DRIER NORTHWEST FLOW IS
EXPECTED TO DOMINATE FROM MONDAY INTO THE MIDDLE OF NEXT WEEK.
LOOKS LIKE MOST AREAS SHOULD REMAIN DRY...OUTSIDE OF SOME ISOLATED
ACTIVITY IN THE MOUNTAINS. TEMPERATURES EXPECTED TO BE NEAR
SEASONAL LEVELS FOR MUCH OF THE PERIOD. FRIEDERS
&&
.AVIATION...
ISOLATED THUNDERSTORMS ARE EXPECTED ACROSS THE REGION THIS
EVENING. LOCAL MVFR CONDITIONS...GUSTY WINDS AND SOME MOUNTAIN
OBSCURATIONS ARE POSSIBLE. CLOUD COVER WILL INCREASE OVERNIGHT
WITH THE POTENTIAL FOR MORE WIDESPREAD SHOWERS MOVING IN BEGINNING
THURSDAY MORNING AND CONTINUING THROUGH THE DAY. FRIEDERS
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 065/087 063/089 062/088 061/088 061/088 061/090 061/085
24/T 43/T 32/T 22/T 21/B 11/U 11/B
LVM 056/088 054/088 053/087 052/088 052/088 053/089 053/087
45/T 54/T 42/T 22/T 22/T 21/B 22/T
HDN 061/088 060/091 059/090 058/090 058/090 058/092 058/088
25/T 43/T 32/T 22/T 21/B 11/U 11/B
MLS 065/092 064/089 064/090 061/089 061/090 061/091 062/088
23/T 44/T 44/T 42/T 21/B 11/B 11/B
4BQ 064/086 064/088 063/089 060/089 059/090 059/090 060/089
26/T 64/T 43/T 32/T 21/B 11/B 11/B
BHK 060/091 061/086 060/087 056/086 056/087 055/087 057/085
34/T 44/T 45/T 43/T 21/B 11/B 22/T
SHR 059/084 057/089 056/089 054/088 054/088 054/089 055/087
26/T 43/T 32/T 22/T 21/B 11/U 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
305 PM PDT WED AUG 13 2014
.SYNOPSIS...DRIER AIR MOVING IN FROM THE WEST WILL LIMIT
THUNDERSTORM COVERAGE MAINLY TO MOHAVE COUNTY THURSDAY AND FRIDAY.
DRY WEATHER AND NEAR NORMAL TEMPERATURES WILL OCCUR THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK.
&&
.DISCUSSION...SATELLITE SHOWING SOME HIGHER TOPPED CONVECTION
ACROSS THE MOUNTAINS OF SOUTHERN CLARK COUNTY/NORTHEAST SAN
BERNARDINO COUNTY. THE STRONGEST STORMS ALONG WITH ANY LIGHTNING
HAVE BEEN OVER FAR NORTHERN LINCOLN COUNTY.
TRIMMED BACK ON POPS SIGNIFICANTLY THIS EVENING BASED ON SATELLITE
AND HRRR DATA LEAVING A SLIGHT CHANCE IN MAINLY FOR LINCOLN/MOHAVE
AND SOUTHERN CLARK COUNTIES.
DRYING WILL CONTINUE THROUGH THURSDAY AND FRIDAY. MOS GUIDANCE
SURFACE DEWPOINTS FOR LAS VEGAS ARE TO FALL FROM OUR CURRENT 60 INTO
THE 40S THURSDAY AND 30S FRIDAY. THIS DRYING WILL LIMIT ANY
THUNDERSTORM THREAT TO FAR EASTERN LINCOLN/MOHAVE COUNTIES TOMORROW.
ON FRIDAY THE ONLY AREA WILL BE FAR EASTERN MOHAVE COUNTY. THE
FORECAST LOOKS TO STAY DRY THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
AS WE LOOSE THE MOISTURE, DAYTIME HIGHS WILL WARM BACK CLOSER TO
NORMAL FROM SATURDAY ONWARD.
&&
.AVIATION...FOR MCCARRAN...CUMULUS WHICH HAS DEVELOPED AROUND THE
SURROUNDING MTNS WILL DISSIPATE THIS EVENING LEAVING SKIES MOSTLY
CLEAR OVERNIGHT. ENOUGH MOISTURE WILL REMAIN IN PLACE FOR CUMULUS
DEVELOPMENT OVER THE MOUNTAINS THURSDAY AFTERNOON. WINDS SHOULD
CONTINUE TO FAVOR AN EAST-SOUTHEAST DIRECTION AT LESS THAN 10 KTS
INTO EARLY EVENING BEFORE SETTLING IN SOUTHERLY OVERNIGHT AND
THURSDAY
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SCATTERED CLOUDS THIS EVENING AND AGAIN THURSDAY WITH A
SLIGHT CHANCE OF THUNDERSTORMS OVER LINCOLN/MOHAVE COUNTIES.
WINDS WILL FAVOR TYPICAL DIURNAL WIND PATTERNS THROUGH THURSDAY
EXCEPT NEAR THUNDERSTORMS THIS AFTERNOON.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION SHOULD NOT BE
REQUIRED THURSDAY THROUGH THE WEEKEND.
&&
$$
PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
247 PM MDT WED AUG 13 2014
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 247 PM MDT WED AUG 13 2014
UPPER RIDGING ACROSS THE CENTRAL CONUS CONTINUES WITH AN UPPER LOW
OVER THE PACIFIC NW. DEEP SWRLY FLOW HAS DEVELOPED ACROSS THE DESERT
SW INTO THE GREAT BASIN AND CNTRL ROCKIES...WITH INCREASING
MONSOONAL MOISTURE OVER MUCH OF THE WRN CONUS. A SERIES OF UPPER
WAVES ARE CROSS WY/ERN MT ATTM...WITH A MUCH STRONGER WAVE OVER
AZ/UT. STORMS HAVE ALREADY FIRED AHEAD OF THE FIRST WAVE NOW
CROSSING THE WRN/CNTRL CWA. RAP MODEL IS SHOWING 3000 J/KG
MLCAPE...BUT WITH A CAP IN PLACE...CONVECTION HAS BEEN LIMITED TO
HIGHER TERRAIN OF THE BLKHLS. HRRR SHOWS MORE STORMS DEVELOPING OVER
THE NEXT HOUR OR TWO ACROSS NE WY AND PUSHING EAST THROUGH THE EVNG
HOURS. MOST OF THE STORM ACTIVITY WOULD BE EAST OF THE CWA BY 06Z
WITH LINGERING SHOWERS POSSIBLE. WEAK SHEAR WILL KEEP STORMS FROM
REACHING SEVERE...THOUGH WITH STRONG INSTABILITY CANT RULE OUT A
STORM OR TWO PRODUCING SMALL HAIL AND GUSTY WINDS LIKE THE STORM
OVER THE NORTHERN BLACK HILLS LIKELY DID EARLIER THIS AFTERNOON.
STRONG WAVE OVER THE SWRN CONUS WILL SLIDE NE TONIGHT...THEN CROSS
THE CWA LATE THURSDAY. MONSOONAL FLOW WILL RESULT IN INCREASINGLY
MOIST PROFILES THROUGH THE DAY THURSDAY WITH PWATS FORECAST TO BE
180 PERCENT OF NORMAL OR MORE. WIND PROFILES SUGGEST STORMS WILL BE
SLOW MOVING WITH MEAN STORM MOTION UNDER 10KT. STORMS WILL CONTINUE
THROUGH THURSDAY NIGHT AS THE SYSTEM SLOWLY MOVES E/NE INTO ND/CNTRL
SD. WITH THE HEAVY RAINS THAT MANY AREAS HAVE RECEIVED IN THE LAST
WEEK...THINK THERE WILL BE A POTENTIAL FOR FLASH FLOODING THURSDAY
AFTERNOON AND THROUGH THURSDAY NIGHT. HAVE ISSUED A FLASH FLOOD
WATCH FOR THIS TIME PERIOD.
&&
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 247 PM MDT WED AUG 13 2014
SEVERAL SHORTWAVES WILL AFFECT THE FORECAST AREA FROM FRIDAY INTO
EARLY NEXT WEEK...BRINGING AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS
TO PARTS OF THE FORECAST AREA NEARLY EVERY DAY. ON FRIDAY...A SLOW
MOVING SHORTWAVE HAS THE POTENTIAL TO CREATE LOCALLY HEAVY
RAINFALL GIVEN WEAK 850-300MB STEERING FLOW AND MODELED GREATER THAN
150 PERCENT PRECIPITABLE WATER AMOUNTS. TEMPERATURES THROUGH THE
PERIOD WILL BE WITHIN 5 DEGREES OF THE AVERAGE FOR THIS TIME OF YEAR.
&&
.AVIATION...FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 247 PM MDT WED AUG 13 2014
AN UPPER LEVEL DISTURBANCE WILL CREATE ISOLATED/SCATTERED TSRA THIS
AFTN OVER NORTHEASTERN WY AND THE BLKHLS... WITH THE THUNDERSTORMS
SLOWLY SPREADING EAST THROUGH TONIGHT. VFR CONDITIONS WILL PREVAIL
OUTSIDE OF ANY PRECIPITATION.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY
NIGHT FOR SDZ001-002-012>014-024>032-041>044-072>074.
WY...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY
NIGHT FOR WYZ054>058-071.
&&
$$
SHORT TERM...13
LONG TERM...10
AVIATION...10
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
254 PM CDT WED AUG 13 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 254 PM CDT WED AUG 13 2014
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL TROUGH OVER
EASTERN UNITED STATES. WEAK SHORTWAVE ON THE BACKSIDE OF THE TROUGH
PUSHING SOUTH INTO THE GREAT LAKES PRODUCING CUMULUS CLOUDS ACROSS
THE UPPER GREAT LAKES REGION PER LATEST VISIBLE SATELLITE IMAGERY.
LATEST 19Z SURFACE ANALYSIS INDICATES WEAK COLD FRONT EXTENDING FROM
MICHIGAN INTO WESTERN WISCONSIN AND SURFACE RIDGE OVER ONTARIO AND
SASKATCHEWAN CANADA.
MAIN FORECAST CONCERNS TONIGHT IS FOG POTENTIAL IN RIVER VALLEYS
AND THE FAVORED AREAS IN CENTRAL WISCONSIN.
SURFACE RIDGE OVER SOUTHERN CANADA BUILDS INTO THE FORECAST AREA
TONIGHT. THIS WILL PROVIDE MOSTLY CLEAR SKIES AND CALM WINDS. THE
LATEST 13.12Z GFS/NAM AND 13.15Z RAP BUFKIT SOUNDINGS SHOW AN
INVERSION TO DEVELOP AFTER 06Z AND WINDS ABOVE THE SURFACE TO BE 10
TO 20 KNOTS. IN ADDITION...WITH A DRIER AIRMASS ADVECTING IN AND
NORTHERLY WIND COMPONENT OVERHEAD AND NEAR THE SURFACE. FOG
FORMATION WILL BE HARD TO DEVELOP IN RIVER VALLEYS AND FAVORED AREAS
IN CENTRAL WISCONSIN. HAVE REMOVED PATCHY FOG IN THESE AREAS FOR
TONIGHT.
SURFACE RIDGE WILL REMAIN IN CONTROL OF THE AREA THURSDAY AND
PRODUCE MOSTLY SUNNY SKIES AND DRY WEATHER CONDITIONS ACROSS THE
FORECAST AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 254 PM CDT WED AUG 13 2014
UPPER LEVEL CLOSED LOW OVER THE PACIFIC NORTHWEST EJECTS OUT A PIECE
OF ENERGY INTO THE UPPER MIDWEST AND FLATTENS UPPER LEVEL RIDGE
FRIDAY INTO SATURDAY. THE DPROG/DT OF THE 13.12Z GFS/NAM INDICATES
THIS PIECE OF ENERGY MOVING INTO THE REGION SLIGHTLY FASTER. THE
13.12Z ECMWF IS SLOWER WITH THE PROGRESSION OF THE SHORTWAVE TROUGH
INTO THE UPPER MIDWEST. THE 13.12Z MODELS SHOW INCREASING
LIFT/FORCING AND MOISTURE INTO THE WESTERN HALF OF THE FORECAST AREA
AFTER 18Z FRIDAY. THE 13.12Z GFS/NAM BUFKIT SOUNDINGS SHOW DRY
AIRMASS ALOFT OVER THE FORECAST AREA DURING THE DAY FRIDAY. THIS
COULD INHIBIT PRECIPITATION MOVING INTO THE AREA. FOR NOW...KEPT
SMALL PRECIPITATION CHANCES ACROSS THE FORECAST AREA.
LIFT/FORCING AND MOISTURE INCREASES ACROSS MUCH OF THE FORECAST AREA
AFTER 00Z SATURDAY AND CONTINUES THROUGH MUCH OF THE DAY
SATURDAY...ESPECIALLY OVER THE SOUTHERN HALF OF THE FORECAST AREA.
HAVE INCREASED PRECIPITATION CHANCES ACROSS THIS PART OF THE
FORECAST AREA.
AT THIS TIME...SEVERE WEATHER THREATS LOOKS LOW...AS THE 13.12Z
GFS/NAM BUILD MINIMAL SURFACE BASED CAPE AND BUILD ELEVATED CAPE
OVER THE FORECAST AREA.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES SATURDAY NIGHT INTO
MIDDLE OF NEXT WEEK. THE 13.12Z GFS/ECMWF/GEM CONTINUE TO DEVELOP
WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED STATES
SATURDAY NIGHT INTO MONDAY. THE 13.12Z GFS/ECMWF/GEM DIFFER
SIGNIFICANTLY ON TIMING AND PLACEMENT OF SHORTWAVE TROUGHS/SURFACE
FEATURES THROUGH MUCH OF THE TIME PERIOD...WHERE THE 13.12Z GFS IS
MORE PROGRESSIVE AND FARTHER SOUTH WITH SHORTWAVE TROUGH/SURFACE
FEATURES SUNDAY INTO MONDAY THAN THE 13.12Z GEM/ECMWF. BASED ON
THE DIFFERENCES IN TIMING AND PLACEMENT WITH SHORTWAVE ENERGY
THROUGH THIS TIME PERIOD...CONFIDENCE IN FORECAST REMAINS LOW AND
WILL KEEP PRECIPITATION CHANCES THROUGH EARLY OF NEXT WEEK. THE
UNSETTLED WEATHER PATTERN WILL CONTINUE INTO MIDDLE OF NEXT
WEEK...AS THE 13.12Z GFS/ECMWF ARE HINTING AT WEST TO
SOUTHWESTERLY FLOW ALOFT TO DEVELOP OVER THE ROCKY MOUNTAINS AND
CENTRAL UNITED STATES. THE 13.12Z GFS/ECMWF INDICATE AN IMPULSE TO
EJECT OUT INTO THE CENTRAL UNITED STATES WEDNESDAY. HOWEVER...WITH
TIMING AND PLACEMENT ISSUES IN ASSOCIATION WITH THE SHORTWAVE
TROUGH/SURFACE FEATURES...REGION COULD SEE A BREAK IN
PRECIPITATION CHANCES WEDNESDAY. TEMPERATURES THROUGH MUCH OF THE
PERIOD WILL BE NEAR NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1224 PM CDT WED AUG 13 2014
SURFACE ANALYSIS INDICATES A WEAK COLD FRONT WAS SLIDING SOUTH
ACROSS CENTRAL MINNESOTA AND WISCONSIN. A FEW CLOUDS WERE
DEVELOPING AHEAD OF THIS FRONT...BUT EXPECT THE FRONT TO MOVE
THROUGH BOTH TAF SITES BY OR NEAR 18Z AND ANY VFR CEILINGS THAT
DEVELOP SHOULD THEN BE TO THE SOUTH. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT WITH CLEAR SKIES EXPECTED OVERNIGHT. THE WINDS
WILL BECOME LIGHT OVERNIGHT BUT THE 13.12Z NAM BUFKIT SOUNDINGS
SUGGESTS THERE IS LITTLE POTENTIAL FOR VALLEY FOG TO FORM.
TEMP/DEW POINT SPREADS ARE EXPECTED TO REMAIN AROUND 5F WITH THE
POTENTIAL FOR A DEEP LAYER OF 10 TO 20 KNOTS WINDS JUST ABOVE THE
SURFACE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...04
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1259 PM CDT WED AUG 13 2014
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY...TONIGHT...AND THURSDAY
ISSUED AT 156 AM CDT WED AUG 13 2014
RELATIVELY QUIET PERIOD. MAIN CONCERN IS WEAK BACK DOOR COLD FRONT
THAT WILL SLIDE ACROSS AREA DURING FIRST PART OF DAY. 13/00Z
NAM/GFS/ECMWF AND 13/03Z HRRR ALL INDICATE PRECIP WILL FORM SOUTH
OF FORECAST AREA THIS AFTERNOON ASSOC WITH BETTER INSTABILITY. AT
THAT POINT FRONT WILL BE ALONG OR SOUTH OF SOUTHERN BORDER OF FORECAST
AREA. NE WINDS MAY PICK UP FOR A BRIEF TIME BEHIND FRONT LATE
AFTERNOON INTO EARLY EVENING...THEN SFC HIGH PRESSURE MOVES SOUTH FROM
HUDSON BAY PROVIDING COOL NIGHT AND MILD THURSDAY. TEMPS TONIGHT
WILL PROBABLY TOUCH THE 30S IN FAR NORTHERN BOGS.
TEMP AND WIND FORECAST A BLEND OF PREVIOUS FORECAST WITH BEST
PERFORMING MODEL GUIDANCE.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY
ISSUED AT 156 AM CDT WED AUG 13 2014
NORTHWEST FLOW ALOFT DUE TO UPPER LOW ACROSS EASTERN CANADA WILL
BECOME MORE ZONAL BY THE WEEKEND. UPPER PATTERN SUCH THAT MODELS
ARE HAVING A HARD TIME WITH FEATURES AND WHEN AND WHERE BEST
CHANCES OF RAIN WOULD OCCUR. TEMPERATURES DURING THE PERIOD SHOULD
BE AT OR SLIGHTLY ABOVE NORMAL FOR MID AUGUST.
MODELS CONTINUE TO DIFFER IF PRECIPITATION WOULD BREAK OUT ON THE
BACKSIDE OF THE HIGH DUE TO 850MB WARM ADVECTION. LEANING TOWARD
SHOWERS AND STORMS BREAKING OUT WEST OF THE AREA THURSDAY NIGHT...
THUS LEFT THIS PERIOD DRY. WILL CONTINUE THE CHANCES FOR SHOWERS
AND STORMS FRIDAY AS BOUNDARY PUSHES NORTH. A CONTINUED CHANCE FOR
SHOWERS AND STORMS WILL CONTINUE FRIDAY NIGHT AND SATURDAY. UPPER
FLOW STILL NORTHWEST AT THIS POINT...THUS EXPECT BOUNDARY TO PUSH
SOUTH OF THE AREA SATURDAY NIGHT AND SUNDAY. HAVE REMOVED RAIN
CHANCES ACROSS THE NORTH SATURDAY NIGHT AND SUNDAY AS HIGH PRESSURE
BUILDS INTO THE AREA. ALMOST TEMPTED TO REMOVE RAIN CHANCES ACROSS
THE SOUTH...BUT CONFIDENCE WAS LOWER IN CASE BOUNDARY SHOULD LINGER
ACROSS THE AREA. BEYOND SUNDAY...LOW CONFIDENCE IN THE DETAILS OF
ANY WEATHER MAKER AND WHEN THE BEST CHANCES FOR SHOWERS AND STORMS
COULD OCCUR. DID NOT MAKE ANY SIGNIFICANT CHANGES BEYOND SUNDAY.
ONLY ADJUSTMENTS TO MAX/MIN TEMPERATURE GRIDS WAS TO ADD A DEGREE
OR TWO AT NIGHT AT THE TYPICALLY WARMER LOCATIONS...AND DROPPED A
DEGREE OR TWO IN THE TYPICAL COOLER SPOTS AT NIGHT.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1258 PM CDT WED AUG 13 2014
A SURFACE COLD FRONT WAS SOUTH OF THE FORECAST AREA BY 17Z AND
HIGH PRESSURE WAS STARTING TO BUILD IN BEHIND IT. THERE WAS QUITE
A BIT OF CUMULUS BEHIND THE FRONT BUT CIGS WERE MAINLY VFR...WITH
ISOLATED MVFR IN CENTRAL WISCONSIN. AS THE HIGH BUILDS IN WINDS
WILL SHIFT TO NORTH-NORTHEAST LATE THIS AFTERNOON IN THE KGRB AND
KATW AREAS SO HAVE SOME HIGHER SPEEDS AND GUSTS AT KGRB DUE TO
TRAJECTORY OVER THE WATERS OF GREEN BAY. CLOUDS SHOULD DISSIPATE
AROUND OR SHORTLY AFTER SUNSET AND WINDS IN EASTERN WISCONSIN
SHOULD BACK A BIT. WIND SPEEDS WILL BE LIGHT DURING THE OVERNIGHT
HOURS...AND WITH GENERALLY CLEAR SKIES...TEMPERATURES SHOULD DROP
RATHER QUICKLY. 12Z MOS GUIDANCE AGAIN SHOWED UNRESTRICTED VSBYS
TONIGHT BUT MAV DEW POINT DEPRESSIONS WERE ZERO TO 2F AT TIMES SO
HAVE A MENTION OF FOG...ESPECIALLY AT KAUW...KCWA...AND KRHI. WINDS
ON THURSDAY MORNING SHOULD BE LIGHT AND CLEAR SKIES ARE EXPECTED
ONCE ANY FOG DISSIPATES.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....JKL
LONG TERM......ECKBERG
AVIATION.......MG