Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 05/21/14
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
210 PM PDT MON MAY 19 2014
...NEW MARINE DISCUSSION...
.SYNOPSIS...
A LOW SYSTEM WILL BRING BELOW NORMAL TEMPERATURES...POSSIBLE
PRECIPITATION...ESPECIALLY MOUNTAIN AREAS...AND BREEZY WINDS THROUGH
THURSDAY. THE LOW WILL SLOWLY MOVE EAST ON FRIDAY WITH TEMPERATURES
FORECAST TO EXCEED NORMAL. A HIGH WILL BULGE IN SATURDAY FOR AN
ADDITIONAL WARMING OF TEMPERATURES INTO EARLY NEXT WEEK.
&&
.SHORT TERM (TONIGHT-THU)...
IMPACTFUL WEATHER WILL BE MINIMAL THROUGH DAY7. GUSTY NORTHWEST
WINDS WILL GENERATE GALE FORCE WINDS FOR THE OUTER COASTAL WATERS
AND A WEAK SUNDOWNER IS EXPECTED ACROSS SANTA BARBARA COUNTY
TONIGHT. HRRR HIGH RESOLUTION MODEL DATA SHOWS GUSTS 38KTS BETWEEN
GOLETA AND GAVIOTA THIS EVENING. OTHER WEATHER PROBLEM OF THE NIGHT
IS THE DEPTH OF THE MARINE LAYER AND EXTENT OF CLOUD COVER BY
TUESDAY MORNING. NAM BUFR SOUNDINGS INDICATE WELL ABOVE 5000 FEET
AND BOUNDARY LAYER HUMIDITY GOES ABOVE 90 PERCENT ACROSS MOST OF THE
AREA BY 12Z. HAVE PUSHED CLOUDS WELL INTO THE SOUTH SLOPES OF THE
MOUNTAINS AND ACROSS MOST OF SLO COUNTY WITH THE ADDITION OF DRIZZLE
TOMORROW MORNING.
LOW PRESSURE WAS DEEPENING RAPIDLY OFF THE NORTHERN CA COAST THIS
AFTERNOON AND WILL SWING INTO THE SACRAMENTO VALLEY BY 12Z
TUESDAY...THEN EASTWARD INTO NV THROUGH WEDNESDAY. A SECONDARY
DISTURBANCE WILL ROTATE AROUND THE LOW DUMBBELLING INTO ANOTHER LOW
ACROSS SOUTHERN CA ON THURSDAY. THERE IS MINIMAL MOISTURE CONTENT
WITH THIS SYSTEM BUT IT IS ALREADY GENERATING THUNDERSTORMS ACROSS
THE NORTHERN SIERRAS. AS THIS SYSTEM ROTATES SOUTH AND EAST THROUGH
THURSDAY EXPECT TO SEE TEMPERATURES SLOWLY DECREASE DUE TO VARYING
AMOUNTS OF CLOUDS AND A SLIGHT CHANCE OF RAIN SHOWERS FOCUSED ON THE
HIGHER ELEVATIONS. WE WILL NEED TO KEEP AN EYE ON THE POTENTIAL FOR
CONVECTION WEDNESDAY AND THURSDAY AFTERNOONS FORMING OVER THE
SOUTHERN SIERRAS AND ACROSS THE SAN GABRIEL MOUNTAINS. INSTABILITY
PARAMETERS ARE INDICATING 33 DEGREE K-INDEX...NEGATIVE LIFTED
INDEX...AND UP TO 500 J/KG CAPE FOR THE MOUNTAINS. IF CELLS DEVELOP
STEERING WINDS OUT OF THE NORTH-NORTHWEST COULD PUSH ACTIVITY INTO
THE LOS ANGELES COUNTY VALLEYS OR FARTHER SOUTHWARD IF THEY CAN
MAINTAIN THEIR STRENGTH.
.LONG TERM (FRI-MON)...
MODEL CONSENSUS THAT THE UPPER LOW WILL SHIFT TO THE AZ/MEXICO
BORDER ON FRIDAY AS THE TROUGH AXIS AND BULK OF ANY MOISTURE WILL BE
MAINLY EAST OF OUR AREA. LEFT A TOKEN SLIGHT CHANCE OF SHOWERS FOR
THE EASTERN SAN GABRIELS ON FRIDAY...OTHERWISE DRY WITH A WARMING
TREND. A HIGH PRESSURE RIDGE WILL BUILD INTO SOUTHWEST CA THROUGH
THE HOLIDAY WEEKEND WITH 585DM HEIGHTS BY SUNDAY. TEMPERATURES WILL
WARM BACK INTO THE 80S TO LOWER 90S ACROSS VALLEY AREAS. GFS AND GEM
MODELS THEN BRING ANOTHER LOW PRESSURE SYSTEM TO THE PACIFIC
NORTHWEST COAST ON MONDAY LOWERING HEIGHTS AND REDUCING TEMPERATURES
OVER CA. HOWEVER...THE ECM CONTINUES TO HOLD ONTO THE RIDGE THROUGH
MOST OF NEXT WEEK. FOR NOW WILL KEEP TEMPERATURES JUST AS WARM FOR
MONDAY UNTIL WE CAN GET BETTER MODEL AGREEMENT ON WHETHER THE RIDGE
WILL BREAKDOWN OR NOT EARLY NEXT WEEK.
&&
.AVIATION...19/1800Z.
LOW CONFIDENCE IN THE CLOUD FORECAST ACROSS THE ENTIRE DISTRICT.
THERE IS A POSSIBILITY THAT CLOUDS WILL HAVE LESS COVERAGE THAN
FORECAST. THERE IS ALSO A POSSIBILITY THAT CLOUD COVERAGE WILL
EXTEND WELL INTO TUESDAY AFTERNOON. ANY CEILINGS THAT DO FORM WILL
PROBABLY EXIST IN THE MVFR TO VFR CATEGORY DUE TO A VERY DEEP MARINE
LAYER EXPECTED TONIGHT.
KLAX...TIMING OF ONSET AND DURATION OF COVERAGE ARE BOTH SUSPECT
TONIGHT SO EXPECT SOME SURPRISES DUE TO LOW CONFIDENCE IN THE
FORECAST.
KBUR...TIMING OF ONSET AND DURATION OF COVERAGE ARE BOTH SUSPECT
TONIGHT SO EXPECT SOME SURPRISES DUE TO LOW CONFIDENCE IN THE
FORECAST.
&&
.MARINE...19/300 PM.
THE INNER WATERS ARE LIKELY TO EXPERIENCE SMALL CRAFT ADVISORY LEVEL
WINDS THROUGH TONIGHT THAT WILL AFFECT THE WESTERN SANTA BARBARA
CHANNEL...MAINLY WEST OF SANTA CRUZ ISLAND AND WATERS WEST OF SANTA
CATALINA ISLAND. GALE WARNINGS REMAIN FOR PZ673 AND PZ676 WHERE THE
STRONGEST WINDS WILL OCCUR THROUGH LATE TONIGHT. A SMALL CRAFT
ADVISORY ALSO REMAINS IN EFFECT FOR PZ645 AND PZ670 FOR WINDS
GUSTING TO AROUND 30 KNOTS.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...BOLDT
AVIATION/MARINE...SWEET
SYNOPSIS...SETO
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
201 PM PDT MON MAY 19 2014
.SYNOPSIS...COOLER THAN NORMAL TEMPERATURES ARE FORECAST EARLY THIS
WEEK AS AN UPPER LEVEL SYSTEM MOVES ACROSS NORTHERN CALIFORNIA. A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS EXISTS LATE THIS
AFTERNOON AND AGAIN TUESDAY AFTERNOON BUT MAINLY OVER THE REMOTE
HILLS OF THE BAY AREA AND MONTEREY BAY REGION. DRY CONDITIONS WILL
RETURN ALONG WITH A WARMING TREND FOR THE SECOND HALF OF THE WEEK
AND INTO THE HOLIDAY WEEKEND AS HIGH PRESSURE BUILDS ALONG THE
WEST COAST.
&&
.DISCUSSION...AS OF 2:01 PM PDT MONDAY...COLD CORE UPPER LOW IS
NOW LOCATED WEST OF CAPE MENDOCINO WITH SHOWERS AND T-STORMS
FIRING OVER NORTHEAST CALIFORNIA AND MOST RECENTLY AS CLOSE AS
COLUSA AND GLENN COUNTIES. FOLLOWING THE RAP MODEL THE UPPER LOW
WILL QUICKLY MAKE A BEELINE FOR THE NORTH BAY LATER THIS EVENING
AND OVERNIGHT. THEREFORE THE BEST CHANCE OF ANY SHOWER OR ISOLATED
T-STORMS WILL BE OVER THE NORTH BAY HILLS...BEST CHANCE OVER
NORTHERN SONOMA AND NAPA COUNTY HILLS.
THE LATEST SOLUTIONS BRING THE LOW INTO THE CENTRAL VALLEY BY
TUESDAY MORNING WITH SOME NW ONSHORE SHOWERS POSSIBLE ALONG THE
BIG SUR COAST EARLY TUESDAY. OTHERWISE EXPECT A PARTLY CLOUDY AND
COOL DAY ON TUESDAY WITH SOME SHOWERS AND T-STORMS POSSIBLE BY
AFTERNOON...AGAIN MOST LIKELY OVER THE HIGHER TERRAIN/REMOTE AREAS
ROUGHLY RUNNING FROM NAPA COUNTY SOUTHWARD INTO THE DIABLO RANGE
AND OVER FAR EASTERN SANTA CLARA AND SAN BENITO COUNTIES. THE
COOLER TEMPS AND HIGHER HUMIDITY WILL MITIGATE MOST FIRE WEATHER
CONCERNS. FOR MOST FOLKS THE WEATHER WILL FEATURE PARTY CLOUDY AND
SEASONABLE TEMPS.
BY WEDS THE LOW WILL EJECT INTO NEVADA WITH ISOLATED CHANCES ONLY
REMAINING OVER THE HIGHER TERRAIN OF SAN BENITO AND FAR SOUTHEAST
MONTEREY COUNTY.
HIGH PRESSURE WILL BEGIN TO NOSE OVER THE REGION THURSDAY AND INTO
THE UPCOMING WEEKEND WITH A NOTED WARMING TREND AS 850 MB TEMPS
WARM TO AROUND 21-23 CELSIUS INLAND BY SUNDAY AND MEMORIAL DAY.
&&
.AVIATION...AS OF 12:50 PM PDT MONDAY...CONDITIONS HAVE IMPROVED
FOLLOWING A BRIEF PUSH OF MVFR CONDITIONS THIS MORNING. MAINLY
CLEAR SKIES EXPECTED WITH INCREASING WEST WINDS THIS AFTERNOON AND
GUSTS OF 20 TO 30 KTS BY 00Z TUE. EXPECTING MVFR CIGS TO RETURN TO
SITES TONIGHT IN THE 06-09Z TIME FRAME AND IMPROVE IN THE 15-18Z
WINDOW. WESTERLY WINDS TO PERSIST THROUGH THE PERIOD.
VICINITY OF KSFO...VFR WITH INCREASING WEST WINDS MAY GUST TO 30
KTS AFTER 22Z. MVFR CIGS TO RETURN AFTER 06Z AND WINDS TO DIMINISH
TO AROUND 10 KTS WESTERLY. MVFR CIGS WILL LIFT 15-16Z TIME FRAME
TUE AM AND WEST WINDS PERSIST.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO. MEDIUM CONFIDENCE.
MONTEREY BAY AREA TERMINALS...SATELLITE SHOWS LOW CLOUDS HAVE
DISSIPATED IN MONTEREY BAY AREA AND WILL REMAIN WITH A VFR
FORECAST THROUGH 00Z TUE AND FORECAST RETURN TO MVFR CIGS AFTER
THAT. WESTERLY WINDS GUSTS AROUND 20 KTS THIS AFTERNOON WILL
DIMINISH OVERNIGHT. MVFR CIGS TO PERSIST THROUGH END OF PERIOD AT
KMRY.
&&
.MARINE...AS OF 03:45 AM PDT MONDAY...SURFACE HIGH PRESSURE WILL
DOMINATE THE EASTERN PACIFIC THROUGH THE FORECAST...RESULTING IN
NORTHWEST WINDS OVER THE WATERS. WINDS WILL INCREASE WEDNESDAY
INTO THE WEEKEND GENERATING STEEP FRESH SWELLS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PT ARENA TO PT REYES 10-60 NM FROM 2 AM
SCA...PT ARENA TO PT REYES 0-10 NM FROM 6 AM
SCA...PT REYES TO PIGEON PT 10-60 NM FROM 6 AM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 6 AM
SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 9 PM
SCA...SF BAY SOUTH OF THE BAY BRIDGE UNTIL 9 PM
SCA...MONTEREY BAY UNTIL 9 PM
&&
$$
PUBLIC FORECAST: RWW
AVIATION/MARINE: RILEY
VISIT US AT WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
150 PM PDT MON MAY 19 2014
.SYNOPSIS...
A LOW SYSTEM WILL BRING BELOW NORMAL TEMPERATURES...POSSIBLE
PRECIPITATION...ESPECIALLY MOUNTAIN AREAS...AND BREEZY WINDS THROUGH
THURSDAY. THE LOW WILL SLOWLY MOVE EAST ON FRIDAY WITH TEMPERATURES
FORECAST TO EXCEED NORMAL. A HIGH WILL BULGE IN SATURDAY FOR AN
ADDITIONAL WARMING OF TEMPERATURES INTO EARLY NEXT WEEK.
&&
.SHORT TERM (TONIGHT-THU)...
IMPACTFUL WEATHER WILL BE MINIMAL THROUGH DAY7. GUSTY NORTHWEST
WINDS WILL GENERATE GALE FORCE WINDS FOR THE OUTER COASTAL WATERS
AND A WEAK SUNDOWNER IS EXPECTED ACROSS SANTA BARBARA COUNTY
TONIGHT. HRRR HIGH RESOLUTION MODEL DATA SHOWS GUSTS 38KTS BETWEEN
GOLETA AND GAVIOTA THIS EVENING. OTHER WEATHER PROBLEM OF THE NIGHT
IS THE DEPTH OF THE MARINE LAYER AND EXTENT OF CLOUD COVER BY
TUESDAY MORNING. NAM BUFR SOUNDINGS INDICATE WELL ABOVE 5000 FEET
AND BOUNDARY LAYER HUMIDITY GOES ABOVE 90 PERCENT ACROSS MOST OF THE
AREA BY 12Z. HAVE PUSHED CLOUDS WELL INTO THE SOUTH SLOPES OF THE
MOUNTAINS AND ACROSS MOST OF SLO COUNTY WITH THE ADDITION OF DRIZZLE
TOMORROW MORNING.
LOW PRESSURE WAS DEEPENING RAPIDLY OFF THE NORTHERN CA COAST THIS
AFTERNOON AND WILL SWING INTO THE SACRAMENTO VALLEY BY 12Z
TUESDAY...THEN EASTWARD INTO NV THROUGH WEDNESDAY. A SECONDARY
DISTURBANCE WILL ROTATE AROUND THE LOW DUMBBELLING INTO ANOTHER LOW
ACROSS SOUTHERN CA ON THURSDAY. THERE IS MINIMAL MOISTURE CONTENT
WITH THIS SYSTEM BUT IT IS ALREADY GENERATING THUNDERSTORMS ACROSS
THE NORTHERN SIERRAS. AS THIS SYSTEM ROTATES SOUTH AND EAST THROUGH
THURSDAY EXPECT TO SEE TEMPERATURES SLOWLY DECREASE DUE TO VARYING
AMOUNTS OF CLOUDS AND A SLIGHT CHANCE OF RAIN SHOWERS FOCUSED ON THE
HIGHER ELEVATIONS. WE WILL NEED TO KEEP AN EYE ON THE POTENTIAL FOR
CONVECTION WEDNESDAY AND THURSDAY AFTERNOONS FORMING OVER THE
SOUTHERN SIERRAS AND ACROSS THE SAN GABRIEL MOUNTAINS. INSTABILITY
PARAMETERS ARE INDICATING 33 DEGREE K-INDEX...NEGATIVE LIFTED
INDEX...AND UP TO 500 J/KG CAPE FOR THE MOUNTAINS. IF CELLS DEVELOP
STEERING WINDS OUT OF THE NORTH-NORTHWEST COULD PUSH ACTIVITY INTO
THE LOS ANGELES COUNTY VALLEYS OR FARTHER SOUTHWARD IF THEY CAN
MAINTAIN THEIR STRENGTH.
.LONG TERM (FRI-MON)...
MODEL CONSENSUS THAT THE UPPER LOW WILL SHIFT TO THE AZ/MEXICO
BORDER ON FRIDAY AS THE TROUGH AXIS AND BULK OF ANY MOISTURE WILL BE
MAINLY EAST OF OUR AREA. LEFT A TOKEN SLIGHT CHANCE OF SHOWERS FOR
THE EASTERN SAN GABRIELS ON FRIDAY...OTHERWISE DRY WITH A WARMING
TREND. A HIGH PRESSURE RIDGE WILL BUILD INTO SOUTHWEST CA THROUGH
THE HOLIDAY WEEKEND WITH 585DM HEIGHTS BY SUNDAY. TEMPERATURES WILL
WARM BACK INTO THE 80S TO LOWER 90S ACROSS VALLEY AREAS. GFS AND GEM
MODELS THEN BRING ANOTHER LOW PRESSURE SYSTEM TO THE PACIFIC
NORTHWEST COAST ON MONDAY LOWERING HEIGHTS AND REDUCING TEMPERATURES
OVER CA. HOWEVER...THE ECM CONTINUES TO HOLD ONTO THE RIDGE THROUGH
MOST OF NEXT WEEK. FOR NOW WILL KEEP TEMPERATURES JUST AS WARM FOR
MONDAY UNTIL WE CAN GET BETTER MODEL AGREEMENT ON WHETHER THE RIDGE
WILL BREAKDOWN OR NOT EARLY NEXT WEEK.
&&
.AVIATION...19/1800Z.
LOW CONFIDENCE IN THE CLOUD FORECAST ACROSS THE ENTIRE DISTRICT.
THERE IS A POSSIBILITY THAT CLOUDS WILL HAVE LESS COVERAGE THAN
FORECAST. THERE IS ALSO A POSSIBILITY THAT CLOUD COVERAGE WILL
EXTEND WELL INTO TUESDAY AFTERNOON. ANY CEILINGS THAT DO FORM WILL
PROBABLY EXIST IN THE MVFR TO VFR CATEGORY DUE TO A VERY DEEP MARINE
LAYER EXPECTED TONIGHT.
KLAX...TIMING OF ONSET AND DURATION OF COVERAGE ARE BOTH SUSPECT
TONIGHT SO EXPECT SOME SURPRISES DUE TO LOW CONFIDENCE IN THE
FORECAST.
KBUR...TIMING OF ONSET AND DURATION OF COVERAGE ARE BOTH SUSPECT
TONIGHT SO EXPECT SOME SURPRISES DUE TO LOW CONFIDENCE IN THE
FORECAST.
&&
.MARINE...19/0900 AM.
SOME CHANGES WERE MADE TO THE MORNING FORECAST. THE INNER WATERS ARE
LIKELY TO EXPERIENCE SMALL CRAFT ADVISORY LEVEL WINDS THIS AFTERNOON
THAT WILL AFFECT THE WESTERN SANTA BARBARA CHANNEL...MAINLY WEST OF
SANTA CRUZ ISLAND AND WATERS WEST OF SANTA CATALINA ISLAND. GALE
WARNINGS REMAIN FOR PZ673 AND PZ676 WHERE THE STRONGEST WINDS WILL
OCCUR THROUGH LATE TONIGHT. A SMALL CRAFT ADVISORY ALSO REMAINS IN
EFFECT FOR PZ645 AND PZ670 FOR WINDS GUSTING TO AROUND 30 KNOTS.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY (SEE LAXNPWLOX).
GALE WARNING (SEE LAXMWWLOX).
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...BOLDT
AVIATION/MARINE...SWEET
SYNOPSIS...SETO
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
934 AM PDT MON MAY 19 2014
.SYNOPSIS...COOLER THAN NORMAL TEMPERATURES ARE FORECAST EARLY THIS
WEEK AS AN UPPER LEVEL SYSTEM MOVES ACROSS NORTHERN CALIFORNIA. A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS EXISTS THIS AFTERNOON
AND AGAIN TUESDAY AFTERNOON BUT MAINLY OVER THE REMOTE HILLS OF
THE BAY AREA AND MONTEREY BAY REGION. DRY CONDITIONS WILL RETURN
ALONG WITH A WARMING TREND FOR THE SECOND HALF OF THE WEEK AND
INTO THE HOLIDAY WEEKEND AS HIGH PRESSURE BUILDS ALONG THE WEST
COAST.
&&
.DISCUSSION...AS OF 9:34 AM PDT MONDAY...MADE SOME MINOR FORECAST
UPDATES THIS MORNING BUT IN GENERAL NO BIG CHANGE IN THE EVOLUTION
OF ISOLATED SHOWERS AND T-STORM CHANCES. FORECAST PROBLEM OF THE
DAY REMAINS WITH INCOMING COLD CORE LOW AND ASSOCIATED PRECIP.
SHORT TERM...THERE`S A BAND OF MID AND HIGH CLOUDS OVER THE GREATER
BAY AREA AT THIS TIME BUT IN GENERAL SKIES ARE MOSTLY CLEAR TO
PARTLY CLOUDY WITH TEMPERATURES WARMING INTO THE LOW 60S. BY THIS
AFTERNOON HIGHS WILL WARM INTO THE UPPER 60S TO MID 70S AT THE
SURFACE WHICH WILL HELP TO DESTABILIZE THINGS SOMEWHAT. THERE IS
AN UNSEASONABLY COLD UPPER LOW CURRENTLY OFF THE OREGON COAST THAT
WILL ROTATE TOWARDS CAPE MENDOCINO AND EVENTUALLY PASS OVER THE
BAY AREA AND CENTRAL CALIFORNIA. VARIOUS SHORT TERM MODELS
INCLUDING THE NAM/HRRR/RUC GENERATE SOME ISOLATED SHOWERS AND
POSSIBLE T-STORMS OVER THE FAR NORTH BAY HILLS LATER THIS
AFTERNOON AND EARLY EVENING. IT APPEARS THAT THE CORE OF THE UPPER
LOW WILL PASS OVER THE BAY AREA LATER TONIGHT WHEN SOLAR HEATING
IS LOST WHICH SHOULD KEEP NIGHT-TIME SHOWERS TO A MINIMUM. ON THE
BACKSIDE OF THE LOW THE LATEST SOLUTIONS HAVE BEEN GENERATING SOME
SPOTTY LIGHT SHOWERS ALONG THE BIG SUR COAST AND HAVE UPDATED THE
FORECAST TO REFLECT THAT.
ON TUESDAY THE LOW WILL PUSH INLAND AND PRODUCE WIDESPREAD SHOWERS
OVER THE SIERRA. BY TUESDAY AFTERNOON THERE MAY BE ENOUGH UPPER
INSTABILITY AND SOLAR HEATING TO PRODUCE AFTERNOON AND EVENING
SHOWERS/T-STORMS...WITH THE BEST CHANCE OVER THE HILLS THAT BORDER
THE CENTRAL VALLEY AS WELL AS THE LAKE/YOLO COUNTY BORDERS. GIVEN
ALL THIS TALK OF SHOWERS AND T-STORMS...NEED TO STRESS THAT MOST
URBAN AREAS WILL HAVE LITTLE CHANCE FOR PRECIP. THIS IS THE TYPE
OF EVENT THAT IS FOCUSED OVER THE HILLS AND HIGHER TERRAN.
SHOULD LIGHTNING OCCUR THE LATEST SHORT TERM FIRE DANGER HAS BEEN
LOWERED DUE TO COOLER TEMPERATURES AND HIGHER HUMIDITY SO NOT
EXPECTING AN IDEAL SET-UP FOR NUMEROUS NEW STARTS SHOULD LIGHTNING
DEVELOP. ALSO EVEN THOUGH QPF NUMBERS LOOK VERY DRY THE CORE OF
ANY CELLS SHOULD HAVE PRECIP.
THE UPPER LOW WILL MOVE INTO NEVADA BY MIDWEEK WITH HIGH PRESSURE
NOSING INTO CALIFORNIA WEDNESDAY AND THROUGH THE UPCOMING HOLIDAY
WEEKEND LEADING TO A NOTED WARMING AND DRYING TREND.
&&
.PREV DISCUSSION...AS OF 03:45 AM PDT MONDAY...GENERALLY QUIET
CONDITIONS PERSIST ACROSS THE REGION THIS MORNING IN ADVANCE OF A
MID/UPPER LEVEL STORM SYSTEM CURRENTLY OFF THE WASHINGTON/OREGON
COASTLINE. THIS SYSTEM WILL DROP SOUTH-SOUTHEASTWARD TODAY THROUGH
TUESDAY AND ADVERT A MUCH COOLER AIR MASS OVER THE REGION. DAYTIME
TEMPERATURES WILL BE RELATIVELY COOL FOR THIS TIME OF
YEAR...ESPECIALLY ACROSS INLAND AREAS.
IN ADDITION TO THE UNSEASONABLY COOL CONDITIONS...MID-LEVEL
MOISTURE WILL WRAP AROUND THE MID/UPPER LEVEL LOW AND BRING A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS TO THE REGION TODAY
THROUGH WEDNESDAY. THE BEST CHANCES FOR CONVECTION WILL BE ACROSS
THE NORTH BAY THIS AFTERNOON/EVENING AND AGAIN ON TUESDAY OVER THE
INTERIOR PORTIONS OF THE REGION. THE SYSTEM WILL THEN PUSH INLAND
ACROSS THE STATE OF NEVADA BY WEDNESDAY AND AS TEMPERATURES WARM
WEDNESDAY AFTERNOON/EVENING...CHANCES FOR CONVECTION ARE ONCE
AGAIN POSSIBLE OVER THE MOUNTAINS OF SAN BENITO COUNTY AND
INTERIOR MONTEREY COUNTY. CONFIDENCE REMAINS LOW ON THE EXACT
LOCATION AND TIMING OF ANY CONVECTION TODAY THROUGH
WEDNESDAY...HOWEVER THE POTENTIAL DOES EXIST GIVEN INCREASED
MOISTURE AND INSTABILITY WITH THE AFOREMENTIONED UPPER LEVEL
SYSTEM MOVING ACROSS CENTRAL CALIFORNIA. WITH ALL THAT SAID...MOST
LOCATIONS WILL RECEIVE LITTLE TO NO MEASURABLE RAINFALL THROUGH
MIDWEEK.
THE UPPER LEVEL LOW WILL BE SLOW TO PULL AWAY FROM THE WESTERN
STATES...HOWEVER FORECAST MODELS ARE PERSISTENT WITH BUILDING A
MID/UPPER LEVEL RIDGE ALONG THE WEST COAST FOR THE LATTER HALF OF
THE WORK WEEK. THIS WILL BRING DRY WEATHER ALONG WITH A WARMING
TREND THAT IS EXPECTED TO PERSIST THROUGH THE UPCOMING MEMORIAL
DAY WEEKEND. DAYTIME TEMPERATURES BY THE WEEKEND WILL WARM BACK
INTO THE 80S TO LOWER 90S INLAND AND UPPER 60S TO LOWER 70S ALONG
COASTAL LOCATIONS WITH CONTINUED ONSHORE WINDS.
&&
.AVIATION...AS OF 4:30 AM PDT MONDAY...PATCHY MVFR CIGS THROUGH
THE 18Z HOUR AT MOST TERMINALS...MODERATE CONFIDENCE. PATCHES OF
STRATUS FORMED OFFSHORE OVERNIGHT AND ARE CONTINUING TO EXPAND
THIS MORNING. THE HRRR AND WRF INDICATE THAT EXPANSION WILL
CONTINUE UNTIL AT LEAST THE 17Z HOUR...WITH LINGERING CLOUDS INTO
THE 18-19Z HOUR. OTHERWISE...ANOTHER VERY BREEZY WEST WIND DAY.
VICINITY OF KSFO...MVFR CIGS POSSIBLE BETWEEN 13Z AND 17Z. LOW TO
MEDIUM CONFIDENCE. ONSHORE WIND GUSTS JUST OVER 30 KT WILL BE
POSSIBLE AFTER 20Z.
KSFO BRIDGE APPROACH...APPROACH MAY BE IMPACTED WITH LOW CLOUDS AS
EARLY AS 12Z WITH DISSIPATION AS LATE AS 18Z. LOW CONFIDENCE.
MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH AT LEAST 18Z. THE
WRF AND HRRR INDICATE DISSIPATION OF LOW CLOUDS BY 19Z AROUND
KMRY. HOWEVER...THE NAM SUGGESTS AN ALL DAY EVENT. WILL CONTINUE
TO MONITOR CLOSELY.
&&
.MARINE...AS OF 03:45 AM PDT MONDAY...SURFACE HIGH PRESSURE WILL
DOMINATE THE EASTERN PACIFIC THROUGH THE FORECAST...RESULTING IN
NORTHWEST WINDS OVER THE WATERS. WINDS WILL INCREASE WEDNESDAY
INTO THE WEEKEND GENERATING STEEP FRESH SWELLS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 3 PM
SCA...SF BAY SOUTH OF THE BAY BRIDGE FROM 3 PM
SCA...MONTEREY BAY FROM 3 PM
&&
$$
PUBLIC FORECAST: RWW
AVIATION/MARINE: RILEY
VISIT US AT WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
432 AM PDT MON MAY 19 2014
.SYNOPSIS...COOLER THAN NORMAL TEMPERATURES AND UNSETTLED WEATHER
ARE EXPECTED EARLY THIS WEEK AS AN UPPER LEVEL SYSTEM MOVES
ACROSS THE REGION. SLIGHT CHANCES FOR THUNDERSTORMS EXIST TODAY
THROUGH WEDNESDAY AS THIS SYSTEM MOVES ACROSS...HOWEVER MOST
LOCATIONS WILL RECEIVE LITTLE TO NO RAINFALL. DRY CONDITIONS WILL
RETURN ALONG WITH A WARMING TREND FOR THE LATTER HALF OF THE WEEK
AS HIGH PRESSURE BUILDS ALONG THE WEST COAST.
&&
.DISCUSSION...AS OF 03:45 AM PDT MONDAY...GENERALLY QUIET
CONDITIONS PERSIST ACROSS THE REGION THIS MORNING IN ADVANCE OF A
MID/UPPER LEVEL STORM SYSTEM CURRENTLY OFF THE WASHINGTON/OREGON
COASTLINE. THIS SYSTEM WILL DROP SOUTH-SOUTHEASTWARD TODAY THROUGH
TUESDAY AND ADVECT A MUCH COOLER AIR MASS OVER THE REGION. DAYTIME
TEMPERATURES WILL BE RELATIVELY COOL FOR THIS TIME OF
YEAR...ESPECIALLY ACROSS INLAND AREAS.
IN ADDITION TO THE UNSEASONABLY COOL CONDITIONS...MID-LEVEL
MOISTURE WILL WRAP AROUND THE MID/UPPER LEVEL LOW AND BRING A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS TO THE REGION TODAY
THROUGH WEDNESDAY. THE BEST CHANCES FOR CONVECTION WILL BE ACROSS
THE NORTH BAY THIS AFTERNOON/EVENING AND AGAIN ON TUESDAY OVER THE
INTERIOR PORTIONS OF THE REGION. THE SYSTEM WILL THEN PUSH INLAND
ACROSS THE STATE OF NEVADA BY WEDNESDAY AND AS TEMPERATURES WARM
WEDNESDAY AFTERNOON/EVENING...CHANCES FOR CONVECTION ARE ONCE
AGAIN POSSIBLE OVER THE MOUNTAINS OF SAN BENITO COUNTY AND
INTERIOR MONTEREY COUNTY. CONFIDENCE REMAINS LOW ON THE EXACT
LOCATION AND TIMING OF ANY CONVECTION TODAY THROUGH
WEDNESDAY...HOWEVER THE POTENTIAL DOES EXIST GIVEN INCREASED
MOISTURE AND INSTABILITY WITH THE AFOREMENTIONED UPPER LEVEL
SYSTEM MOVING ACROSS CENTRAL CALIFORNIA. WITH ALL THAT SAID...MOST
LOCATIONS WILL RECEIVE LITTLE TO NO MEASURABLE RAINFALL THROUGH
MIDWEEK.
THE UPPER LEVEL LOW WILL BE SLOW TO PULL AWAY FROM THE WESTERN
STATES...HOWEVER FORECAST MODELS ARE PERSISTENT WITH BUILDING A
MID/UPPER LEVEL RIDGE ALONG THE WEST COAST FOR THE LATTER HALF OF
THE WORK WEEK. THIS WILL BRING DRY WEATHER ALONG WITH A WARMING
TREND THAT IS EXPECTED TO PERSIST THROUGH THE UPCOMING MEMORIAL
DAY WEEKEND. DAYTIME TEMPERATURES BY THE WEEKEND WILL WARM BACK
INTO THE 80S TO LOWER 90S INLAND AND UPPER 60S TO LOWER 70S ALONG
COASTAL LOCATIONS WITH CONTINUED ONSHORE WINDS.
&&
.AVIATION...AS OF 4:30 AM PDT MONDAY...PATCHY MVFR CIGS THROUGH
THE 18Z HOUR AT MOST TERMINALS...MODERATE CONFIDENCE. PATCHES OF
STRATUS FORMED OFFSHORE OVERNIGHT AND ARE CONTINUING TO EXPAND
THIS MORNING. THE HRRR AND WRF INDICATE THAT EXPANSION WILL
CONTINUE UNTIL AT LEAST THE 17Z HOUR...WITH LINGERING CLOUDS INTO
THE 18-19Z HOUR. OTHERWISE...ANOTHER VERY BREEZY WEST WIND DAY.
VICINITY OF KSFO...MVFR CIGS POSSIBLE BETWEEN 13Z AND 17Z. LOW TO
MEDIUM CONFIDENCE. ONSHORE WIND GUSTS JUST OVER 30 KT WILL BE
POSSIBLE AFTER 20Z.
KSFO BRIDGE APPROACH...APPROACH MAY BE IMPACTED WITH LOW CLOUDS AS
EARLY AS 12Z WITH DISSIPATION AS LATE AS 18Z. LOW CONFIDENCE.
MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH AT LEAST 18Z. THE
WRF AND HRRR INDICATE DISSIPATION OF LOW CLOUDS BY 19Z AROUND
KMRY. HOWEVER...THE NAM SUGGESTS AN ALL DAY EVENT. WILL CONTINUE
TO MONITOR CLOSELY.
&&
.MARINE...AS OF 03:45 AM PDT MONDAY...SURFACE HIGH PRESSURE WILL
DOMINATE THE EASTERN PACIFIC THROUGH THE FORECAST...RESULTING IN
NORTHWEST WINDS OVER THE WATERS. WINDS WILL INCREASE WEDNESDAY
INTO THE WEEKEND GENERATING STEEP FRESH SWELLS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 3 PM
SCA...SF BAY SOUTH OF THE BAY BRIDGE FROM 3 PM
SCA...MONTEREY BAY FROM 3 PM
&&
$$
PUBLIC FORECAST: RGASS
AVIATION/MARINE: RILEY
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AREA FORECAST DISCUSSION
NWS EUREKA CA
359 AM PDT MON MAY 19 2014
.SYNOPSIS...AN UPPER LEVEL TROUGH WILL CONTINUE TO BRING SHOWERS
TO THE REGION THROUGH TUESDAY. A FEW THUNDERSTORMS ARE POSSIBLE
MONDAY AND TUESDAY AFTERNOON OVER THE HIGHER TERRAIN. WARMER AND
DRIER CONDITIONS WILL RETURN NEXT WEEK AS HIGH PRESSURE BUILDS
BACK IN.
&&
.DISCUSSION...THE UPPER LOW/TROUGH IS NOW JUST OFF THE COAST OF
CENTRAL OREGON AND WILL MORPH INTO A CLOSED LOW AS IT ENTERS THE
NORTH COAST WATERS THIS AFTERNOON. AS THIS SYSTEM MOVES SOUTH
FAVORABLE SW TO SE FLOW DEVELOPS OVER THE REGION WHILE INSTABILITY
AT MID AND UPPER LEVELS INCREASES. MODELS STILL IN GOOD AGREEMENT
ON SHOWER AND POTENTIAL TSTORM ACTIVITY THIS AFTERNOON ACROSS
INTERIOR PORTIONS OF THE CWA. SURFACE BASED CAPE IS OVER 400 J/KG
IN TRINITY COUNTY AND LAPSE RATES IN THE 700 TO 500 MB LAYER ARE
AROUND 7C/KM. ALTHOUGH AT THIS TIME HRRR MODELED REFLECTIVITY IS
UNIMPRESSIVE SHOWING ONLY SOME LIGHT SHOWER RETURNS OVER THE EAST
SIDE OF THE CWA LATER THIS AFTERNOON. THE THREAT OF RAIN SHOWERS
AND THUNDERSTORMS CONTINUES INTO THIS EVENING BEFORE THE BEST
THERMODYNAMICS AND FORCING SHIFT SOUTH WITH THE UPPER LOW. AS THE
LOW TRACKS INLAND ON TUESDAY ...WRAP- AROUND MOISTURE WILL
CONTINUE THE RAIN CHANCES ACROSS THE INTERIOR. HAVE ADDED A SLIGHT
CHANCE OF THUNDERSTORMS ACROSS EASTERN PORTIONS OF TRINITY AND
MENDOCINO COUNTIES. ALTHOUGH THE FLOW PATTERN IS OUT OF THE NORTH
NORTHEAST (TYPICALLY NOT A FLOW PATTERN THAT GIVES US
THUNDERSTORMS)...A PRETTY ROBUST VORT MAX IS PROGGED TO ROTATE
AROUND THE LOW AND THROUGH THE AREA TUESDAY AFTERNOON COINCIDING
WITH A FAVORABLE JET STREAK POSITION. WITH LI VALUES DOWN TO -3C
AND STEEP MID-LEVEL LAPSE RATES...IT WAS HARD TO IGNORE...ESPECIALLY
SINCE ALL MODELS SHOW SOME SORT OF CONVECTIVE PRECIP OVER THE
REGION THROUGH TUE AFTERNOON. SHOWER AND TSTORM CHANCES DIMINISH
DURING THE EVENING HOURS AS THE LOW TRACKS FURTHER SOUTH AND EAST.
HIGH PRESSURE WILL BUILD BACK IN OVER NORTHWEST CALIFORNIA FOR THE
REMAINDER OF THE WEEK WITH DRIER AND WARMER CONDITIONS EXPECTED.
AS HEIGHTS BUILD...TEMPERATURES WILL INCREASE ACROSS THE INTERIOR
WITH HIGHS IN THE 80S TO NEAR 90 IN VALLEY LOCATIONS. STP/JT
&&
.AVIATION...MVFR CONDITIONS AND LIGHT WINDS TO CALM CONDITIONS WILL
CONTINUE AT KCEC AND KACV THROUGH THIS MORNING DUE TO REDUCED
CEILINGS AND/OR VISIBILITIES AS A WEAKENING TROUGH MOVES ACROSS THE
AREA PRODUCING A FEW LIGHT SHOWERS AT TIMES. MVFR TO VFR CONDITIONS WILL
PREVAIL AT KCEC AND KACV THIS AFTERNOON AND OVERNIGHT WITH LIGHT TO
MODERATE WINDS OCCURRING OVERNIGHT. VFR CONDITIONS AND LIGHT WINDS
WILL CONTINUE AT KUKI THE NEXT FEW DAYS. THE WINDS WILL BECOME
MODERATE AND GUSTY THIS AFTERNOON THEN LIGHT THIS EVENING AND
OVERNIGHT.
&&
.MARINE...A HIGH PRESSURE RIDGE WILL STRENGTHEN ACROSS THE REGION
TUESDAY INCREASING THE PRESSURE GRADIENT ACROSS THE WATERS. THE
WINDS AND SHORT PERIOD SEAS WILL INCREASE TUESDAY AND WEDNESDAY.
SMALL CRAFT ADVISORIES WILL BE IN EFFECT ACROSS ALL THE WATERS
TUESDAY ENDING WEDNESDAY AFTERNOON ACROSS THE NEAR SHORE WATERS AND
THURSDAY AFTERNOON ACROSS THE OUTER WATERS. WIND GUSTS NEAR GALE
FORCE WILL OCCUR AT TIMES ACROSS THE OUTER WATERS TUESDAY NIGHT AND
WEDNESDAY. THE WINDS AND SEAS WILL GRADUALLY DIMINISH THURSDAY AND
FRIDAY AS THE PRESSURE GRADIENT RELAXES ACROSS THE WATERS.
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...SMALL CRAFT ADVISORY FROM 3 AM TUESDAY TO 3 PM PDT WEDNESDAY
PZZ450-455.
SMALL CRAFT ADVISORY FROM 3 AM TUESDAY TO 3 PM PDT THURSDAY
PZZ470-475.
&&
$$
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AREA FORECAST DISCUSSION
NWS PUEBLO CO
1135 AM MDT MON MAY 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM MDT MON MAY 19 2014
CURRENTLY...LATEST SATELLITE IMAGERY AND H5 RUC ANALYSIS INDICATES
INCREASING SOUTHWEST FLOW ACROSS THE STATE...WITH SOME MID TO HIGH
LEVEL CLOUDINESS LINGERING OVER THE FAR EASTERN PLAINS. TEMPS HAVE
REMAINED SOMEWHAT MILD AS OF 4 AM...WITH READINGS IN THE 50S TO
LOWER 60S.
TODAY AND TONIGHT...SHORT RANGE MODELS CONTINUE TO AGREE ON DROPPING
THE UPPER LOW DOWN THE WEST COAST...AND INTO CA THIS AFTN AND EVE.
INCREASING SW FLOW ALOFT ACROSS THE 4 CORNERS WAS DRAWING VERY DRY
AIR UP ACROSS THE DESERT SW...AND IS EXPECTED TO PRODUCE DRY AND
VERY WARM CONDITIONS ACROSS THE CWA TODAY. MAX TEMPS TODAY ARE
FORECAST TO WARM INTO THE LOWER 90S TODAY FOR THE PLAINS...AND INTO
THE MID 70S TO AROUND 80 FOR THE HIGHER VALLEYS. W-SW WINDS AT 15-20
MPH WITH GUSTS UP TO 30 MPH SHOULD FORCE CRITICAL FIRE WX CONDITIONS
THIS AFTN AND EVE FOR THE SLV AND ALL OF THE E PLAINS...SO THE
ONGOING RED FLAG WARNING FOR TODAY LOOKS GOOD. MOORE
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 349 AM MDT MON MAY 19 2014
...CRITICAL FIRE WEATHER CONDITIONS CONTINUE FOR SOUTHERN AND
WESTERN SECTIONS THROUGH MID WEEK...THEN AN UPSWING IN PRECIPITATION
EXPECTED...
SOME SUBTLE CHANGES WITH THIS PACKAGE...ESPECIALLY WITH REGARD TO
THUNDERSTORM PROBABILITIES ON THE PLAINS ON WEDNESDAY...BUT OVERALL
PATTERN ALOFT REMAINS FAIRLY SIMILAR. UPPER LOW WILL BE DROPPING TO
THE SOUTHWEST ACROSS CA/NV ON TUESDAY WHICH WILL KEEP DRY SOUTHWEST
FLOW OVER THE REGION. SHALLOW FRONT WHICH PENETRATES INTO NORTHERN
SECTIONS OF THE SOUTHEAST PLAINS EARLY TUESDAY MORNING WILL LIFT
BACK NORTHWARD DURING THE AFTERNOON...LEAVING MAJORITY OF THE AREA
DRY AGAIN FOR TUESDAY AFTERNOON. 00Z RUN OF NAM12 SUGGESTED PIKES
PEAK REGION COULD SEE AN ISOLATED HIGH BASED THUNDERSTORM...BUT 06Z
RUNS HAVE TRENDED DRIER. OF GREATER CONCERN WILL BE THE POTENTIAL
FOR CRITICAL FIRE WEATHER CONDITIONS TO RETURN FOR THE SAN LUIS
VALLEY AND SOUTHERN SECTIONS OF THE SOUTHEAST PLAINS. WITH DEW
POINTS FALLING OFF INTO THE SINGLE DIGITS AND LOW TEENS ACROSS THE
MOUNTAINS AND SOUTHERN SECTIONS OF THE SOUTHEAST PLAINS...HITTING
CRITICAL THRESHOLDS FOR RELATIVE HUMIDITY WILL BE NO PROBLEM. WINDS
ARE THE BIGGER CHALLENGE AND DEPEND ON THE TIMING OF THE FRONT
LIFTING BACK NORTHWARD. AREA WITH GREATEST POTENTIAL TO SEE THE
GUSTY WINDS WILL BE THE SAN LUIS VALLEY...FOLLOWED BY LAS ANIMAS AND
BACA COUNTIES...SO WILL BE HOISTING A FIRE WEATHER WATCH FOR THESE
AREAS. THERE IS SOME POTENTIAL THAT EL PASO COUNTY COULD SEE GUSTY
WINDS MIX DOWN IN THE AFTERNOON...BUT WILL HOLD OFF INCLUDING THEM
FOR NOW AS FRONT MAY BE LURKING IN THIS AREA.
FRONT DROPS BACK SOUTHWARD INTO THE SOUTHEAST PLAINS TUESDAY
NIGHT...AND COULD SEE SOME STRATUS DEVELOP ACROSS PORTIONS OF THE
PLAINS TOWARDS MORNING. 00Z RUNS OF BOTH NAM AND GFS KEEP THE FRONT
IN ACROSS SOUTHEAST CO...THOUGH DO MIX OUT SOME OF THE DEW POINTS
ACROSS THE SOUTHERN I-25 CORRIDOR IN THE AFTERNOON. HOWEVER WITH
DEW POINTS REMAINING IN THE LOWER 40S TO LOWER 50S ACROSS NORTHERN
SECTIONS OF THE SOUTHEAST PLAINS...COULD SEE CAPE VALUES APPROACH
1000-1500 J/KG. 06Z NAM HAS TRENDED THE FRONT FARTHER NORTH. 0-6KM
SHEARS WILL BE RUNNING AROUND 40-50 KTS...SO IF MOISTURE CAN STAY
IN...THEN THERE WILL BE A CHANCE FOR SEVERE THUNDERSTORMS ACROSS
NORTHERN EL PASO AND KIOWA COUNTIES...AND THIS AREA IS CURRENTLY
OUTLOOKED BY SPC IN A SLIGHT RISK. WILL MAINTAIN SOME SLIGHT CHANCE
POPS FOR THESE AREAS DURING THE LATE AFTERNOON/EARLY EVENING. WILL
HAVE TO MONITOR THE WALDO CANYON BURN SCAR CLOSELY THIS DAY...BUT
HUNCH IS THAT DEW POINTS WILL MIX OUT SOME ACROSS THE HIGHER TERRAIN
OF TELLER COUNTY WHICH WILL MAKE THUNDERSTORMS A BIT TOO HIGH BASED.
BUT ONCE AGAIN...POSITION OF THE FRONT WILL MEAN EVERYTHING.
MEANWHILE...DRY SOUTHWEST FLOW WILL MIX DOWN INTO THE SAN LUIS
VALLEY ONCE AGAIN...WITH ANOTHER ROUND OF CRITICAL FIRE WEATHER
CONDITIONS POSSIBLE FOR WEDNESDAY.
CLOSED LOW WILL DROP INTO THE DESERT SOUTHWEST ON FRIDAY...AND
EXTENDED MODELS HAVE TRENDED A BIT FASTER WITH MOVING THIS SYSTEM
EASTWARD ACROSS NM OVER THE WEEKEND...WITH GFS FASTER THAN THE EC.
SOUTHERLY FLOW AHEAD OF THE SYSTEM WILL ADVECT HIGHER DEW POINTS
NORTHWARD INTO THE REGION...WHICH WILL INCREASE THUNDERSTORM CHANCES
AND THE THREAT FOR HEAVY RAINFALL ON AREA BURN SCARS THROUGH THE
REMAINDER OF THE EXTENDED. 0-6 KM SHEARS DECREASE AS THE UPPER LOW
APPROACHES OVER THE WEEKEND...AND CAPE VALUES WILL BE DEPENDENT ON
THE AMOUNT OF DEW POINT RETURN. A LOT WILL DEPEND ON THE
DETAILS...BUT IN GENERAL SHOULD SEE LESS OF A FIRE WEATHER
CONCERN...AND MORE OF A HEAVY RAIN THREAT THROUGH THE WEEKEND. -KT
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1133 AM MDT MON MAY 19 2014
VFR CONDITIONS FOR THE REGION INCLUDING THE THREE MAIN TAF SITES OF
KCOS...KPUB AND KALS FOR THE NEXT 24 HRS. GUSTY W-SW WINDS 25-35 MPH
ARE EXPECTED FROM 18Z THROUGH 03Z. IT WILL BE LESS WINDY AT THE
TAF SITES ON TUESDAY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ224-226>237.
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR COZ224-230-233-237.
&&
$$
SHORT TERM...MOORE
LONG TERM...KT
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
418 AM MDT MON MAY 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM MDT MON MAY 19 2014
CURRENTLY...LATEST SATELLITE IMAGERY AND H5 RUC ANALYSIS INDICATES
INCREASING SOUTHWEST FLOW ACROSS THE STATE...WITH SOME MID TO HIGH
LEVEL CLOUDINESS LINGERING OVER THE FAR EASTERN PLAINS. TEMPS HAVE
REMAINED SOMEWHAT MILD AS OF 4 AM...WITH READINGS IN THE 50S TO
LOWER 60S.
TODAY AND TONIGHT...SHORT RANGE MODELS CONTINUE TO AGREE ON DROPPING
THE UPPER LOW DOWN THE WEST COAST...AND INTO CA THIS AFTN AND EVE.
INCREASING SW FLOW ALOFT ACROSS THE 4 CORNERS WAS DRAWING VERY DRY
AIR UP ACROSS THE DESERT SW...AND IS EXPECTED TO PRODUCE DRY AND
VERY WARM CONDITIONS ACROSS THE CWA TODAY. MAX TEMPS TODAY ARE
FORECAST TO WARM INTO THE LOWER 90S TODAY FOR THE PLAINS...AND INTO
THE MID 70S TO AROUND 80 FOR THE HIGHER VALLEYS. W-SW WINDS AT 15-20
MPH WITH GUSTS UP TO 30 MPH SHOULD FORCE CRITICAL FIRE WX CONDITIONS
THIS AFTN AND EVE FOR THE SLV AND ALL OF THE E PLAINS...SO THE
ONGOING RED FLAG WARNING FOR TODAY LOOKS GOOD. MOORE
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 349 AM MDT MON MAY 19 2014
...CRITICAL FIRE WEATHER CONDITIONS CONTINUE FOR SOUTHERN AND
WESTERN SECTIONS THROUGH MID WEEK...THEN AN UPSWING IN PRECIPITATION
EXPECTED...
SOME SUBTLE CHANGES WITH THIS PACKAGE...ESPECIALLY WITH REGARD TO
THUNDERSTORM PROBABILITIES ON THE PLAINS ON WEDNESDAY...BUT OVERALL
PATTERN ALOFT REMAINS FAIRLY SIMILAR. UPPER LOW WILL BE DROPPING TO
THE SOUTHWEST ACROSS CA/NV ON TUESDAY WHICH WILL KEEP DRY SOUTHWEST
FLOW OVER THE REGION. SHALLOW FRONT WHICH PENETRATES INTO NORTHERN
SECTIONS OF THE SOUTHEAST PLAINS EARLY TUESDAY MORNING WILL LIFT
BACK NORTHWARD DURING THE AFTERNOON...LEAVING MAJORITY OF THE AREA
DRY AGAIN FOR TUESDAY AFTERNOON. 00Z RUN OF NAM12 SUGGESTED PIKES
PEAK REGION COULD SEE AN ISOLATED HIGH BASED THUNDERSTORM...BUT 06Z
RUNS HAVE TRENDED DRIER. OF GREATER CONCERN WILL BE THE POTENTIAL
FOR CRITICAL FIRE WEATHER CONDITIONS TO RETURN FOR THE SAN LUIS
VALLEY AND SOUTHERN SECTIONS OF THE SOUTHEAST PLAINS. WITH DEW
POINTS FALLING OFF INTO THE SINGLE DIGITS AND LOW TEENS ACROSS THE
MOUNTAINS AND SOUTHERN SECTIONS OF THE SOUTHEAST PLAINS...HITTING
CRITICAL THRESHOLDS FOR RELATIVE HUMIDITY WILL BE NO PROBLEM. WINDS
ARE THE BIGGER CHALLENGE AND DEPEND ON THE TIMING OF THE FRONT
LIFTING BACK NORTHWARD. AREA WITH GREATEST POTENTIAL TO SEE THE
GUSTY WINDS WILL BE THE SAN LUIS VALLEY...FOLLOWED BY LAS ANIMAS AND
BACA COUNTIES...SO WILL BE HOISTING A FIRE WEATHER WATCH FOR THESE
AREAS. THERE IS SOME POTENTIAL THAT EL PASO COUNTY COULD SEE GUSTY
WINDS MIX DOWN IN THE AFTERNOON...BUT WILL HOLD OFF INCLUDING THEM
FOR NOW AS FRONT MAY BE LURKING IN THIS AREA.
FRONT DROPS BACK SOUTHWARD INTO THE SOUTHEAST PLAINS TUESDAY
NIGHT...AND COULD SEE SOME STRATUS DEVELOP ACROSS PORTIONS OF THE
PLAINS TOWARDS MORNING. 00Z RUNS OF BOTH NAM AND GFS KEEP THE FRONT
IN ACROSS SOUTHEAST CO...THOUGH DO MIX OUT SOME OF THE DEW POINTS
ACROSS THE SOUTHERN I-25 CORRIDOR IN THE AFTERNOON. HOWEVER WITH
DEW POINTS REMAINING IN THE LOWER 40S TO LOWER 50S ACROSS NORTHERN
SECTIONS OF THE SOUTHEAST PLAINS...COULD SEE CAPE VALUES APPROACH
1000-1500 J/KG. 06Z NAM HAS TRENDED THE FRONT FARTHER NORTH. 0-6KM
SHEARS WILL BE RUNNING AROUND 40-50 KTS...SO IF MOISTURE CAN STAY
IN...THEN THERE WILL BE A CHANCE FOR SEVERE THUNDERSTORMS ACROSS
NORTHERN EL PASO AND KIOWA COUNTIES...AND THIS AREA IS CURRENTLY
OUTLOOKED BY SPC IN A SLIGHT RISK. WILL MAINTAIN SOME SLIGHT CHANCE
POPS FOR THESE AREAS DURING THE LATE AFTERNOON/EARLY EVENING. WILL
HAVE TO MONITOR THE WALDO CANYON BURN SCAR CLOSELY THIS DAY...BUT
HUNCH IS THAT DEW POINTS WILL MIX OUT SOME ACROSS THE HIGHER TERRAIN
OF TELLER COUNTY WHICH WILL MAKE THUNDERSTORMS A BIT TOO HIGH BASED.
BUT ONCE AGAIN...POSITION OF THE FRONT WILL MEAN EVERYTHING.
MEANWHILE...DRY SOUTHWEST FLOW WILL MIX DOWN INTO THE SAN LUIS
VALLEY ONCE AGAIN...WITH ANOTHER ROUND OF CRITICAL FIRE WEATHER
CONDITIONS POSSIBLE FOR WEDNESDAY.
CLOSED LOW WILL DROP INTO THE DESERT SOUTHWEST ON FRIDAY...AND
EXTENDED MODELS HAVE TRENDED A BIT FASTER WITH MOVING THIS SYSTEM
EASTWARD ACROSS NM OVER THE WEEKEND...WITH GFS FASTER THAN THE EC.
SOUTHERLY FLOW AHEAD OF THE SYSTEM WILL ADVECT HIGHER DEW POINTS
NORTHWARD INTO THE REGION...WHICH WILL INCREASE THUNDERSTORM CHANCES
AND THE THREAT FOR HEAVY RAINFALL ON AREA BURN SCARS THROUGH THE
REMAINDER OF THE EXTENDED. 0-6 KM SHEARS DECREASE AS THE UPPER LOW
APPROACHES OVER THE WEEKEND...AND CAPE VALUES WILL BE DEPENDENT ON
THE AMOUNT OF DEW POINT RETURN. A LOT WILL DEPEND ON THE
DETAILS...BUT IN GENERAL SHOULD SEE LESS OF A FIRE WEATHER
CONCERN...AND MORE OF A HEAVY RAIN THREAT THROUGH THE WEEKEND. -KT
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 349 AM MDT MON MAY 19 2014
VFR CONDITIONS FOR THE REGION INCLUDING THE THREE MAIN TAF SITES OF
KCOS...KPUB AND KALS FOR THE NEXT 24 HRS. GUSTY W-SW WINDS 25-30 MPH
ARE EXPECTED TO DEVELOP AFTER 16Z AND LAST THROUGH 03Z .
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 10 AM THIS MORNING TO 8 PM MDT THIS
EVENING FOR COZ224-226>237.
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR COZ224-230-233-237.
&&
$$
SHORT TERM...MOORE
LONG TERM...KT
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS ALBANY NY
620 AM EDT MON MAY 19 2014
.SYNOPSIS...
AN UPPER LEVEL LOW WILL MOVE OVER NEW ENGLAND
TODAY...WITH JUST SOME ISOLATED SHOWERS FOR MUCH OF THE REGION. HIGH
PRESSURE WILL BUILD IN FROM THE SOUTH WITH DRY WEATHER AND WARMER
TEMPERATURES ON TUESDAY. A FRONTAL SYSTEM WILL BEGIN TO APPROACH THE
REGION ON WEDNESDAY WITH SOME RAIN SHOWERS AND ISOLATED
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 620 AM EDT...AN UPPER LEVEL LOW IS SITUATED OVER NORTHERN
NEW ENGLAND. THIS SYSTEM IS EXPECTED TO SLOWLY DRIFT SOUTHEAST
DURING THE DAY TODAY.
SKIES RANGE FROM PARTLY CLOUDY OVER THE ADIRONDACKS TO CLEAR FOR
SOUTHERN AREAS. A FEW SPRINKLES OR LIGHT RAIN SHOWERS MAY BE
OCCURRING OVER THE ADIRONDACKS UNDER THE PATCHES OF MID LEVEL
CLOUDS. OTHERWISE...ADDITIONAL CLOUDS WILL BE DEVELOPING DURING
THE DAY TODAY THANKS TO COOL TEMPS ALOFT ASSOCIATED WITH THIS
FEATURE. IN ADDITION...SOME MORE ISOLATED RAIN SHOWERS WILL
OCCUR BY AFTN...ESP OVER THE CATSKILLS AND BERKSHIRES...AS SOME ENERGY
ROTATES AROUND THE BACKSIDE OF THE UPPER LOW. BOTH OUR LOCAL
HIRES WRF AND THE 3KM HRRR SHOW ISOLATED CELLULAR SHOWERS
DEVELOPING DURING DAYTIME HEATING...AND MOVING FROM NW TO SE
ACROSS THE AREA. ANY RAIN SHOWERS WILL BE RATHER BRIEF AND PRODUCE
LITTLE RAINFALL. MOST AREAS SHOULD STAY DRY FOR THE MAJORITY OF
THE DAY.
THE COOL TEMPS ALOFT WILL ALSO PROMOTE GOOD MIXING...ALLOWING FOR
A BREEZY AFTN. NW WINDS MAY GUST AS HIGH AS 20-30 MPH...ESP IN
AREAS OF CHANNELED FLOW. MAX TEMPS TODAY LOOK A TAD HIGHER THAN
YESTERDAY...WITH MID TO UPPER 60S FOR VALLEY AREAS...WITH UPPER
50S TO LOW 60S OVER THE HIGH TERRAIN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE UPPER LEVEL LOW WILL MOVE EASTWARD AND AWAY FROM THE REGION
FOR TONIGHT. THIS WILL ALLOW SOME RIDGING TO BUILD INTO THE AREA
ALOFT...WITH A SFC HIGH PRESSURE PASSING OVER THE AREA FOR
TUESDAY. AS A RESULT...DRY WEATHER IS EXPECTED TONIGHT INTO
TOMORROW WITH MILDER TEMPERATURES. MIN TEMPS TONIGHT WILL MAINLY
BE IN THE UPPER 30S TO MID 40S....WITH HIGHS TOMORROW IN THE UPPER
6OS TO MID 70S.
HIGH PRESSURE WILL SHIFT AWAY FROM THE AREA ON TUESDAY
NIGHT...ALLOWING FOR CLOUDS TO INCREASE. IN ADDITION...A SOUTHERLY
FLOW AT LOW LEVELS WILL HELP PREVENT TEMPS FROM FALLING TOO MUCH.
OVERNIGHT LOWS WILL BE IN THE 40S...WITH CONTINUED DRY CONDITIONS.
A WARM FRONT WILL START TO APPROACH THE AREA FOR WEDNESDAY INTO
WEDNESDAY NIGHT. ITS HARD TO SAY IF THIS WARM FRONT WILL MAKE IT
THROUGH OUR ENTIRE AREA...OR IF IT WILL GET HUNG UP TO OUR SOUTH.
THE MODELS ALL SHOW A PERIOD OF RAIN SHOWERS MOVING ACROSS THE
REGION BETWEEN WED AND WED NIGHT...ALTHOUGH THEY VARY ON THE EXACT
TIMING...INTENSITY...AND PLACEMENT OF HEAVIEST QPF. THE 00Z GFS IS
CERTAINLY THE WETTEST MODEL...WITH A LARGE AREA OF HEAVY RAIN
SHOWERS MOVING FROM WEST TO EAST ACROSS MUCH OF OUR AREA. THE 00Z
ECMWF SHOWS A SIMILAR IDEA...BUT NOT QUITE AS HEAVY. FOR NOW...WE
WILL GO WITH LIKELY POPS DURING THIS PERIOD. INSTABILITY APPEARS
MEAGER...SO WILL ONLY GO WITH SLIGHT CHC FOR THUNDER DURING THIS
TIME. MAX TEMPS ON WED LOOK TO REACH NEAR 70...WITH 50S FOR WED
NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
MODEL GUIDANCE IS IN GOOD AGREEMENT THAT ANOTHER UPPER LEVEL LOW
WILL MOVE SOUTHEASTWARD ACROSS THE REGION THURSDAY AND FRIDAY
BRINGING UNSETTLED AND COOL WEATHER TO THE AREA...ESPECIALLY ON
THURSDAY AS THE LOW APPROACHES.
HEIGHTS ARE EXPECTED TO RISE OVER THE HOLIDAY WEEKEND WITH HIGH
PRESSURE BUILDING IN AT THE SURFACE. HOWEVER THE REGION IS EXPECTED
TO BE UNDER CYCLONIC FLOW SATURDAY AS THE UPPER LOW MOVES
NORTHEASTWARD INTO THE CANADIAN MARITIMES...SO CAN NOT RULE OUT
SCATTERED SHOWERS ESPECIALLY WITH THE HEATING OF THE DAY. DRY
WEATHER AND SEASONABLY WARM TEMPERATURES ARE EXPECTED FOR THE REST
OF HOLIDAY WEEKEND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD...12Z/TUESDAY.
AN UPPER LEVEL LOW AND ITS ASSOCIATED COLD POOL WILL MOVE SLOWLY
SOUTHEASTWARD OVER NEW ENGLAND TODAY. AN INCREASE IN CLOUDS WILL
OCCUR ALONG WITH THE THREAT OF ISOLATED LIGHT RAIN SHOWERS DURING
THE AFTERNOON. HAVE NO MENTION OF SHOWERS IN TAFS SINCE LIKELIHOOD
IS SO LOW. CLOUD COVER WILL BE ON THE DECREASE DURING THE EVENING.
LIGHT TO CALM WINDS EARLY THIS MORNING. A NORTH TO NORTHWEST FLOW
WILL PICK AROUND SUNRISE INCREASING TO 10 TO 15 KNOTS WITH GUSTS OF
18 TO 22 KNOTS DURING THE AFTERNOON. WINDS WILL BEGIN TO DIMINISH IN
THE EVENING.
OUTLOOK...
TUE NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WED-THU: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
THU NIGHT-FRI: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
...LOW RH VALUES WITH GUSTY WINDS THIS AFTERNOON...
A NEARBY UPPER LEVEL LOW PRESSURE AREA WILL ALLOW FOR ISOLATED
RAIN SHOWERS TODAY...WITH DRY WEATHER FOR TONIGHT AND TOMORROW.
RAIN SHOWERS ARE LIKELY ON WEDNESDAY.
RH VALUES WILL FALL TO AROUND 30 PERCENT THIS AFTERNOON WITH
NORTHWEST WINDS OF 10 TO 20 MPH. THERE MAY BE A FEW HIGHER
GUSTS...ESP OVER THE HIGH TERRAIN. WINDS WILL DECREASE TO UNDER 5
MPH TONIGHT WITH RH VALUES RETURNING TO 85 TO 100 PERCENT. RH
VALUES WILL ONCE AGAIN DROP TO 25 TO 35 PERCENT TOMORROW AFTERNOON
WITH NORTHWEST WINDS AROUND 10 TO 15 MPH.
&&
.HYDROLOGY...
A RIVER FLOOD WARNING CONTINUES FOR THE MOHAWK RIVER AT UTICA.
THE RIVER STAGE IS CURRENTLY FALLING...AND IS EXPECTED TO FALL
BELOW FLOOD STAGE DURING THE DAY TODAY.
AFTER HEAVY RAINFALL FROM A FEW DAYS AGO...RIVER LEVELS ARE
CONTINUING TO RECEDE ACROSS THE REGION. SOME ISOLATED TO SCATTERED
SHOWERS ARE POSSIBLE TODAY...BUT ANY RAINFALL WILL HAVE LITTLE TO
NO EFFECT ON AREA RIVERS AND STREAMS. DRY WEATHER WILL BE IN PLACE
TOMORROW.
THE NEXT CHANCE FOR MORE WIDESPREAD SHOWERS AND THUNDERSTORMS WILL
BE WEDNESDAY INTO THURSDAY...AS A FRONTAL SYSTEM IMPACTS THE
REGION. WHILE A WIDESPREAD HEAVY RAINFALL ISN/T ANTICIPATED...WE
WILL NEED TO WATCH FOR LOCALLY HEAVY DOWNPOURS DURING THIS PERIOD.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NYZ038>041-043-
047-054-058-063-083-084.
MA...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MAZ001-025.
VT...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR VTZ013>015.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...IAA
AVIATION...IAA
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
421 AM EDT MON MAY 19 2014
.SYNOPSIS...
AN UPPER LEVEL LOW WILL MOVE OVER NEW ENGLAND
TODAY...WITH JUST SOME ISOLATED SHOWERS FOR MUCH OF THE REGION. HIGH
PRESSURE WILL BUILD IN FROM THE SOUTH WITH DRY WEATHER AND WARMER
TEMPERATURES ON TUESDAY. A FRONTAL SYSTEM WILL BEGIN TO APPROACH THE
REGION ON WEDNESDAY WITH SOME RAIN SHOWERS AND ISOLATED
THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 421 AM EDT...AN UPPER LEVEL LOW IS SITUATED OVER NORTHERN
NEW ENGLAND. THIS SYSTEM IS EXPECTED TO SLOWLY DRIFT SOUTHEAST
DURING THE DAY TODAY. ALTHOUGH SKIES ARE STARTING THE DAY RATHER
CLEAR...COOL TEMPS ALOFT ASSOCIATED WITH THIS FEATURE WILL PROMOTE
SOME CLOUDS TO DEVELOP DURING THE DAY TODAY. IN ADDITION...SOME
ISOLATED RAIN SHOWERS WILL OCCUR...ESP OVER THE CATSKILLS AND
BERKSHIRES. BOTH OUR LOCAL HIRES WRF AND THE 3KM HRRR SHOW
ISOLATED CELLULAR SHOWERS DEVELOPING DURING DAYTIME HEATING...AND
MOVING FROM NW TO SE ACROSS THE AREA. ANY RAIN SHOWERS WILL BE
RATHER BRIEF AND PRODUCE LITTLE RAINFALL. MOST AREAS SHOULD STAY
DRY FOR THE MAJORITY OF THE DAY.
THE COOL TEMPS ALOFT WILL ALSO PROMOTE GOOD MIXING...ALLOWING FOR
A BREEZY AFTN. NW WINDS MAY GUST AS HIGH AS 20-30 MPH...ESP IN
AREAS OF CHANNELED FLOW. MAX TEMPS TODAY LOOK A TAD HIGHER THAN
YESTERDAY...WITH MID TO UPPER 60S FOR VALLEY AREAS...WITH UPPER
50S TO LOW 60S OVER THE HIGH TERRAIN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE UPPER LEVEL LOW WILL MOVE EASTWARD AND AWAY FROM THE REGION
FOR TONIGHT. THIS WILL ALLOW SOME RIDGING TO BUILD INTO THE AREA
ALOFT...WITH A SFC HIGH PRESSURE PASSING OVER THE AREA FOR
TUESDAY. AS A RESULT...DRY WEATHER IS EXPECTED TONIGHT INTO
TOMORROW WITH MILDER TEMPERATURES. MIN TEMPS TONIGHT WILL MAINLY
BE IN THE UPPER 30S TO MID 40S....WITH HIGHS TOMORROW IN THE UPPER
6OS TO MID 70S.
HIGH PRESSURE WILL SHIFT AWAY FROM THE AREA ON TUESDAY
NIGHT...ALLOWING FOR CLOUDS TO INCREASE. IN ADDITION...A SOUTHERLY
FLOW AT LOW LEVELS WILL HELP PREVENT TEMPS FROM FALLING TOO MUCH.
OVERNIGHT LOWS WILL BE IN THE 40S...WITH CONTINUED DRY CONDITIONS.
A WARM FRONT WILL START TO APPROACH THE AREA FOR WEDNESDAY INTO
WEDNESDAY NIGHT. ITS HARD TO SAY IF THIS WARM FRONT WILL MAKE IT
THROUGH OUR ENTIRE AREA...OR IF IT WILL GET HUNG UP TO OUR SOUTH.
THE MODELS ALL SHOW A PERIOD OF RAIN SHOWERS MOVING ACROSS THE
REGION BETWEEN WED AND WED NIGHT...ALTHOUGH THEY VARY ON THE EXACT
TIMING...INTENSITY...AND PLACEMENT OF HEAVIEST QPF. THE 00Z GFS IS
CERTAINLY THE WETTEST MODEL...WITH A LARGE AREA OF HEAVY RAIN
SHOWERS MOVING FROM WEST TO EAST ACROSS MUCH OF OUR AREA. THE 00Z
ECMWF SHOWS A SIMILAR IDEA...BUT NOT QUITE AS HEAVY. FOR NOW...WE
WILL GO WITH LIKELY POPS DURING THIS PERIOD. INSTABILITY APPEARS
MEAGER...SO WILL ONLY GO WITH SLIGHT CHC FOR THUNDER DURING THIS
TIME. MAX TEMPS ON WED LOOK TO REACH NEAR 70...WITH 50S FOR WED
NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
MODEL GUIDANCE IS IN GOOD AGREEMENT THAT ANOTHER UPPER LEVEL LOW
WILL MOVE SOUTHEASTWARD ACROSS THE REGION THURSDAY AND FRIDAY
BRINGING UNSETTLED AND COOL WEATHER TO THE AREA...ESPECIALLY ON
THURSDAY AS THE LOW APPROACHES.
HEIGHTS ARE EXPECTED TO RISE OVER THE HOLIDAY WEEKEND WITH HIGH
PRESSURE BUILDING IN AT THE SURFACE. HOWEVER THE REGION IS EXPECTED
TO BE UNDER CYCLONIC FLOW SATURDAY AS THE UPPER LOW MOVES
NORTHEASTWARD INTO THE CANADIAN MARITIMES...SO CAN NOT RULE OUT
SCATTERED SHOWERS ESPECIALLY WITH THE HEATING OF THE DAY. DRY
WEATHER AND SEASONABLY WARM TEMPERATURES ARE EXPECTED FOR THE REST
OF HOLIDAY WEEKEND.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD...06Z/TUESDAY.
AN UPPER LEVEL LOW AND ITS ASSOCIATED COLD POOL WILL MOVE SLOWLY
SOUTHEASTWARD OVER NEW ENGLAND TODAY. AN INCREASE IN CLOUDS WILL
OCCUR ALONG WITH THE THREAT OF ISOLATED LIGHT RAIN SHOWERS DURING
THE AFTERNOON. HAVE NO MENTION OF SHOWERS IN TAFS SINCE LIKELIHOOD
IS SO LOW. CLOUD COVER WILL BE ON THE DECREASE DURING THE EVENING.
LIGHT TO CALM WINDS EARLY THIS MORNING. A NORTH TO NORTHWEST FLOW
WILL PICK AROUND SUNRISE INCREASING TO 10 TO 15 KNOTS WITH GUSTS OF
18 TO 22 KNOTS DURING THE AFTERNOON. WINDS WILL BEGIN TO DIMINISH IN
THE EVENING.
OUTLOOK...
TUE NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WED-THU: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
THU NIGHT-FRI: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
&&
.FIRE WEATHER...
...LOW RH VALUES WITH GUSTY WINDS THIS AFTERNOON...
A NEARBY UPPER LEVEL LOW PRESSURE AREA WILL ALLOW FOR ISOLATED
RAIN SHOWERS TODAY...WITH DRY WEATHER FOR TONIGHT AND TOMORROW.
RAIN SHOWERS ARE LIKELY ON WEDNESDAY.
RH VALUES WILL FALL TO AROUND 30 PERCENT THIS AFTERNOON WITH
NORTHWEST WINDS OF 10 TO 20 MPH. THERE MAY BE A FEW HIGHER
GUSTS...ESP OVER THE HIGH TERRAIN. WINDS WILL DECREASE TO UNDER 5
MPH TONIGHT WITH RH VALUES RETURNING TO 85 TO 100 PERCENT. RH
VALUES WILL ONCE AGAIN DROP TO 25 TO 35 PERCENT TOMORROW AFTERNOON
WITH NORTHWEST WINDS AROUND 10 TO 15 MPH.
&&
.HYDROLOGY...
A RIVER FLOOD WARNING CONTINUES FOR THE MOHAWK RIVER AT UTICA.
THE RIVER STAGE IS CURRENTLY FALLING...AND IS EXPECTED TO FALL
BELOW FLOOD STAGE DURING THE DAY TODAY.
AFTER HEAVY RAINFALL FROM A FEW DAYS AGO...RIVER LEVELS ARE
CONTINUING TO RECEDE ACROSS THE REGION. SOME ISOLATED TO SCATTERED
SHOWERS ARE POSSIBLE TODAY...BUT ANY RAINFALL WILL HAVE LITTLE TO
NO EFFECT ON AREA RIVERS AND STREAMS. DRY WEATHER WILL BE IN PLACE
TOMORROW.
THE NEXT CHANCE FOR MORE WIDESPREAD SHOWERS AND THUNDERSTORMS WILL
BE WEDNESDAY INTO THURSDAY...AS A FRONTAL SYSTEM IMPACTS THE
REGION. WHILE A WIDESPREAD HEAVY RAINFALL ISN/T ANTICIPATED...WE
WILL NEED TO WATCH FOR LOCALLY HEAVY DOWNPOURS DURING THIS PERIOD.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR NYZ038>041-043-
047-054-058-063-083-084.
MA...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MAZ001-025.
VT...FROST ADVISORY UNTIL 8 AM EDT THIS MORNING FOR VTZ013>015.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...IAA
AVIATION...IAA
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
215 PM EDT MON MAY 19 2014
THIS AFTERNOON THRU TONIGHT...A FEW SHOWERS/T-STORMS ARE EXPECTED
WITH WEAKENING FRONT NEAR FL/GA BORDER ALONG WITH SEA BREEZES. DRIER
AIR ALOFT KEEPING PWAT VALUES DOWN AROUND 1.0 INCH...ALONG WITH VERY
LITTLE DYNAMIC SUPPORT...LEAD ME TO KEEP POPS LOW. BEST CHANCE
APPEARS TO BE FAR SE GA AND ALONG FL/GA BORDER WITH WEAK
FRONT...WHERE ENHANCED CU CURRENTLY DEVELOPING...WENT 30 POP
THERE...20 POP ELSEWHERE ALONG/W OF EAST COAST SEABREEZE. PRECIP
CHANCES SHOULD CEASE THIS EVENING WITH LOSS OF HEATING AND AS WEAK
SHORTWAVE MOVES OFF THE EAST COAST. CLOUDS WILL CLEAR OUT. MAY SEE
SOME PATCHY LIGHT FOG...BUT KEEPING OUT OF FORECAST FOR NOW AS
THERE`S NO GUIDANCE...INCLUDING HRRR LAMP OR MOS...TO SUGGEST
POTENTIAL FOR MORE THAN PATCHY LIGHT FOG. LOW TEMPS TONIGHT SHOULD
BE IN THE UPPER 50S WELL INLAND...60 TO 65 CLOSER TO COAST AND ST.
JOHNS RIVER.
TUE THROUGH FRI...A WARMING TREND WITH DRY CONDITIONS AS STACKED
HIGH PRESSURE DOMINATES THE DEEP SOUTH. THE SURFACE HIGH PRESSURE
RIDGE AXIS WILL BUILD SOUTHWARD OVER THE AREA TUE & WED WITH LIGHT
WINDS LESS A SEA BREEZE NEAR THE COAST IN THE AFTN. SKIES WILL BE
MOSTLY CLEAR WITH SOME AFTERNOON CUMULUS INLAND. LATE NIGHT FOG
WILL BE MOST PROBABLY TUE NIGHT AFTER MIDNIGHT AS THE RIDGE
SETTLES OVER THE AREA AND TEMPS/DEW PTS FALL INTO THE MID TO UPPER
50S WITH CALM WINDS AND CLEAR SKIES.
THU & FRI THE RIDGE AXIS WILL GRADUALLY SHIFT SOUTH OVER CENTRAL
FL AS A TROUGH AXIS CARVES SOUTHWARD DOWN THE ATLANTIC COAST. LOW
LEVEL WINDS WILL THEN BECOME WNW WITH BREEZY WINDS NEAR 15-20 MPH
AT TIMES OVER SE GA THU & FRI AS THE PRESSURE GRADIENT
STRENGTHENS.
TEMPS WILL WARM ABOVE CLIMO VALUES BY THU & FRI WITH HIGHS ABOVE
90 INLAND WITH THE COAST ONLY REACHING THE UPPER 80S DUE TO
PREVAILING WESTERLY FLOW. MIN TEMPS WILL RANGE FROM THE UPPER 50S
INLAND TUE NIGHT...TO THE MID AND UPPER 60S BY THU NIGHT WITH NEAR
70 ALONG THE ATLANTIC COAST.
.LONG TERM...SAT THROUGH MON...
MEAN LAYER TROUGHING DEVELOPS DOWN THE CONUS ATLANTIC SEABOARD
THIS WEEKEND WITH MOISTURE INCREASING FROM THE NE SUNDAY IN
ADVANCE OF A BACKDOOR COLD FRONT. PRECIPITABLE WATER VALUES RISE
BACK ABOVE 1.25" SUN AS THE SURFACE TROUGH SLIDES IN FROM THE NE.
THE INCREASE IN MOISTURE...UPPER FORCING FROM THE MEAN LAYER
TROUGH OVER THE ATLANTIC COAST...AND SHALLOW FORCING FROM THE
BACKDOOR FRONT AND SEA BREEZES WILL INCREASE RAIN CHANCES INTO
ONLY THE 15-20% RANGE SUN & MON WITH A DIURNAL PATTERN IN
RAINFALL. TEMPS WILL BE A BIT COOLER DUE TO FALLING HEIGHTS WITH
HIGHS NEARING NORMAL VALUES IN THE MID TO UPPER 80S AND LOW IN THE
LOW/MID 60S INLAND TO UPPER 60S COAST.
&&
.AVIATION...VFR CONDITIONS EXPECTED NEXT 24 HRS. INCLUDED VCTS
KJAX...KVQQ...KCRG...KSSI GIVEN POTENTIAL FOR WIDELY SCATTERED TSRA
ALONG WEAKENING FRONT AND SEA BREEZE THIS AFTERNOON.
&&
.MARINE...WEAK FRONT MOVES OVER THE WATERS THIS EVENING AND
WASHES OUT...WHILE HIGH PRESSURE DEVELOPS NORTH OF THE
WATERS...SETTING UP AN ONSHORE FLOW PATTERN TONIGHT AND TUE.
THE HIGH WILL GRADUALLY SETTLE SOUTHWARD OVER THE WATERS MID WEEK.
RIP CURRENTS: A MODERATE RISK IS EXPECTED THE NEXT FEW DAYS DUE TO
AN ONSHORE FLOW AND LONG PERIOD SWELLS.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 58 85 57 90 / 10 10 0 10
SSI 64 78 63 85 / 10 10 0 10
JAX 60 82 59 88 / 10 10 0 0
SGJ 66 78 62 83 / 10 10 0 0
GNV 59 85 57 89 / 20 10 0 10
OCF 62 86 58 89 / 10 0 0 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
ENYEDI/WOLF/WALKER
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NWS PEACHTREE CITY GA
145 PM EDT MON MAY 19 2014
.PREV DISCUSSION... /ISSUED 325 AM EDT MON MAY 19 2014/
SHORT TERM /TODAY THROUGH TUESDAY/...
WEAK BOUNDARY IS SITUATED ACROSS SOUTHERN GA THIS MORNING...WHILE
HIGH PRESSURE IS CENTERED ACROSS THE MIDDLE ATLANTIC.
MAIN STORY FOR THIS MORNING IS THE FOG. DENSE FOG HAS DEVELOPED
MAINLY ACROSS AREAS THAT RECEIVED RAINFALL SUNDAY. VSBYS ARE STILL
BOUNCING AROUND A BIT...BUT DO THINK THAT THEY WILL SETTLE AROUND
1/4 OF A MILE WITHIN MOST OF THE DENSE FOG ADVISORY AREA BY SUNRISE.
THERE IS ONE AREA WHERE CONFIDENCE IS LOW THAT CRITERIA WILL BE
MET...NEAR COLUMBUS...BUT WILL KEEP THE ADVISORY IN EFFECT FOR NOW.
WITH HIGH PRESSURE SETTLING ACROSS THE CWFA ALOFT AND AT THE
SURFACE...PRECIPITATION CHANCES SHOULD BE MINIMAL. THE BEST CHANCES
OF ANY RAIN SHOULD BE ALONG AND SOUTH OF THE WEAK BOUNDARY ACROSS
SOUTHERN GA...OUTSIDE OF THE CWFA. IF THE BOUNDARY MEANDERS NORTH A
BIT INTO THE SOUTHERN CWFA...POPS MAY HAVE TO BE ADDED TO THE
FORECAST. THE NAM IS DRY AND THE GFS IS PRODUCING SOME ISOLD SHRA.
THE HRRR IS PRODUCING SOME ISOLD SHRA...BUT HAS BEEN INCONSISTENT ON
PEGGING AN AREA FOR THE AFTERNOON. SO...WILL LEAVE OUT ANY MENTION
OF POPS FOR NOW...BUT WILL KEEP AN EYE ON SUCCESSIVE RUNS OF THE
HRRR. POPS SHOULD ALSO REMAIN TOO LOW TO MENTION FOR TUESDAY.
HIGH TEMPS SHOULD REMAIN SLIGHTLY BELOW NORMAL TODAY...BUT BEGIN TO
WARM AS THE RIDGING ALOFT REALLY BEGINS TO BUILD ON TUESDAY.
NLISTEMAA
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
UPPER RIDGING DOMINATES AT THE BEGINNING OF THE EXTENDED AND THIS
WILL KEEP THE AREA DRY. BY THURSDAY THOUGH...AN UPPER LEVEL LOW
PUSHING ACROSS CANADA HELPS TO FORCE THE UPPER LEVEL PATTERN
ACROSS THE CWA INTO NORTHWEST FLOW. AS THIS OCCURS...HAVE A
BACKDOOR FRONT PUSHING TOWARDS THE CWA ON THURSDAY. HAVE GONE
AHEAD AND INTRODUCED A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
ACROSS NORTH GEORGIA ON THURSDAY...A DAY EARLIER THAN PREVIOUSLY
FORECAST. AS THIS FRONT SINKS FURTHER SOUTH ON FRIDAY...HAVE
PUSHED THE SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FURTHER
SOUTH. BY THE WEEKEND...THE BOUNDARY IS STILL AROUND...HOWEVER IT
WEAKENS. HAVE LEFT OUT THE MENTION OF PRECIP WITH THAT WITH POPS
OF ONLY 10 PERCENT.
STILL FORECASTING ABOVE NORMAL TEMPERATURES WITH HIGHS IN THE
UPPER 80S TO LOWER 90S AT THE END OF THE WEEK.
11
&&
.AVIATION...
18Z UPDATE...
CEILINGS ACROSS NORTH GA WILL SCATTER THIS AFTERNOON AND SHOULD
REMAIN VFR THROUGH THE EVENING WITH ONLY FEW/SCT 4-5KFT. SOME MVFR
VISIBILITY POSSIBLE 09Z-14Z OTHERWISE NO RESTRICTIONS. LIGHT EAST TO
SOUTHEAST WINDS OVERNIGHT BECOMING LIGHT SOUTHWEST AFTER 14Z.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM TO HIGH CONFIDENCE ON CEILINGS. HIGH CONFIDENCE ALL OTHER
ELEMENTS.
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 76 56 81 64 / 10 10 10 0
ATLANTA 76 59 82 66 / 10 10 10 0
BLAIRSVILLE 71 50 76 58 / 10 10 10 0
CARTERSVILLE 77 58 83 63 / 10 10 10 0
COLUMBUS 81 61 85 67 / 10 10 10 0
GAINESVILLE 74 55 79 64 / 10 10 10 0
MACON 79 58 83 64 / 20 10 10 0
ROME 77 58 84 62 / 10 10 10 0
PEACHTREE CITY 77 57 82 63 / 10 10 10 0
VIDALIA 79 59 83 65 / 20 10 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
722 AM EDT MON MAY 19 2014
.PREV DISCUSSION... /ISSUED 325 AM EDT MON MAY 19 2014/
SHORT TERM /TODAY THROUGH TUESDAY/...
WEAK BOUNDARY IS SITUATED ACROSS SOUTHERN GA THIS MORNING...WHILE
HIGH PRESSURE IS CENTERED ACROSS THE MIDDLE ATLANTIC.
MAIN STORY FOR THIS MORNING IS THE FOG. DENSE FOG HAS DEVELOPED
MAINLY ACROSS AREAS THAT RECEIVED RAINFALL SUNDAY. VSBYS ARE STILL
BOUNCING AROUND A BIT...BUT DO THINK THAT THEY WILL SETTLE AROUND
1/4 OF A MILE WITHIN MOST OF THE DENSE FOG ADVISORY AREA BY SUNRISE.
THERE IS ONE AREA WHERE CONFIDENCE IS LOW THAT CRITERIA WILL BE
MET...NEAR COLUMBUS...BUT WILL KEEP THE ADVISORY IN EFFECT FOR NOW.
WITH HIGH PRESSURE SETTLING ACROSS THE CWFA ALOFT AND AT THE
SURFACE...PRECIPITATION CHANCES SHOULD BE MINIMAL. THE BEST CHANCES
OF ANY RAIN SHOULD BE ALONG AND SOUTH OF THE WEAK BOUNDARY ACROSS
SOUTHERN GA...OUTSIDE OF THE CWFA. IF THE BOUNDARY MEANDERS NORTH A
BIT INTO THE SOUTHERN CWFA...POPS MAY HAVE TO BE ADDED TO THE
FORECAST. THE NAM IS DRY AND THE GFS IS PRODUCING SOME ISOLD SHRA.
THE HRRR IS PRODUCING SOME ISOLD SHRA...BUT HAS BEEN INCONSISTENT ON
PEGGING AN AREA FOR THE AFTERNOON. SO...WILL LEAVE OUT ANY MENTION
OF POPS FOR NOW...BUT WILL KEEP AN EYE ON SUCCESSIVE RUNS OF THE
HRRR. POPS SHOULD ALSO REMAIN TOO LOW TO MENTION FOR TUESDAY.
HIGH TEMPS SHOULD REMAIN SLIGHTLY BELOW NORMAL TODAY...BUT BEGIN TO
WARM AS THE RIDGING ALOFT REALLY BEGINS TO BUILD ON TUESDAY.
NLISTEMAA
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
UPPER RIDGING DOMINATES AT THE BEGINNING OF THE EXTENDED AND THIS
WILL KEEP THE AREA DRY. BY THURSDAY THOUGH...AN UPPER LEVEL LOW
PUSHING ACROSS CANADA HELPS TO FORCE THE UPPER LEVEL PATTERN
ACROSS THE CWA INTO NORTHWEST FLOW. AS THIS OCCURS...HAVE A
BACKDOOR FRONT PUSHING TOWARDS THE CWA ON THURSDAY. HAVE GONE
AHEAD AND INTRODUCED A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
ACROSS NORTH GEORGIA ON THURSDAY...A DAY EARLIER THAN PREVIOUSLY
FORECAST. AS THIS FRONT SINKS FURTHER SOUTH ON FRIDAY...HAVE
PUSHED THE SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FURTHER
SOUTH. BY THE WEEKEND...THE BOUNDARY IS STILL AROUND...HOWEVER IT
WEAKENS. HAVE LEFT OUT THE MENTION OF PRECIP WITH THAT WITH POPS
OF ONLY 10 PERCENT.
STILL FORECASTING ABOVE NORMAL TEMPERATURES WITH HIGHS IN THE
UPPER 80S TO LOWER 90S AT THE END OF THE WEEK.
11
&&
.AVIATION...
12Z UPDATE...
CIGS/VSBYS WILL IMPROVE OVER THE NEXT TWO HOURS TO VFR VALUES.
SCT CU EXPECTED FOR THE REMAINDER OF THE TAF PERIOD BETWEEN
4-5KFT. WINDS WILL BE EASTERLY EARLY THIS MORNING...THEN SWITCH TO
THE SE BY THE AFTERNOON AND THROUGH THE REMAINDER OF THE TAF
PERIOD.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON CIGS/VSBYS AND HOW FAST THEY WILL GO TO VFR
VALUES.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 76 56 81 64 / 10 10 10 0
ATLANTA 76 59 82 66 / 10 10 10 0
BLAIRSVILLE 71 50 76 58 / 10 10 10 0
CARTERSVILLE 77 58 83 63 / 10 10 10 0
COLUMBUS 81 61 85 67 / 10 10 10 0
GAINESVILLE 74 55 79 64 / 10 10 10 0
MACON 79 58 83 64 / 20 10 10 0
ROME 77 58 84 62 / 10 10 10 0
PEACHTREE CITY 77 57 82 63 / 10 10 10 0
VIDALIA 79 59 83 65 / 20 10 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR THE
FOLLOWING ZONES: BANKS...BARROW...BARTOW...BUTTS...CARROLL...
CATOOSA...CHATTOOGA...CHEROKEE...CLARKE...CLAYTON...COBB...
COWETA...DADE...DAWSON...DEKALB...DOUGLAS...FANNIN...FAYETTE...
FLOYD...FORSYTH...GILMER...GORDON...GREENE...GWINNETT...HALL...
HARALSON...HARRIS...HEARD...HENRY...JACKSON...JASPER...LAMAR...
LUMPKIN...MADISON...MERIWETHER...MONROE...MORGAN...MURRAY...
MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...OGLETHORPE...
PAULDING...PICKENS...PIKE...POLK...PUTNAM...ROCKDALE...SOUTH
FULTON...SPALDING...TALBOT...TALIAFERRO...TOWNS...TROUP...
UNION...UPSON...WALKER...WALTON...WHITE...WHITFIELD...WILKES.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
325 AM EDT MON MAY 19 2014
.SHORT TERM /TODAY THROUGH TUESDAY/...
WEAK BOUNDARY IS SITUATED ACROSS SOUTHERN GA THIS MORNING...WHILE
HIGH PRESSURE IS CENTERED ACROSS THE MIDDLE ATLANTIC.
MAIN STORY FOR THIS MORNING IS THE FOG. DENSE FOG HAS DEVELOPED
MAINLY ACROSS AREAS THAT RECEIVED RAINFALL SUNDAY. VSBYS ARE STILL
BOUNCING AROUND A BIT...BUT DO THINK THAT THEY WILL SETTLE AROUND
1/4 OF A MILE WITHIN MOST OF THE DENSE FOG ADVISORY AREA BY SUNRISE.
THERE IS ONE AREA WHERE CONFIDENCE IS LOW THAT CRITERIA WILL BE
MET...NEAR COLUMBUS...BUT WILL KEEP THE ADVISORY IN EFFECT FOR NOW.
WITH HIGH PRESSURE SETTLING ACROSS THE CWFA ALOFT AND AT THE
SURFACE...PRECIPITATION CHANCES SHOULD BE MINIMAL. THE BEST CHANCES
OF ANY RAIN SHOULD BE ALONG AND SOUTH OF THE WEAK BOUNDARY ACROSS
SOUTHERN GA...OUTSIDE OF THE CWFA. IF THE BOUNDARY MEANDERS NORTH A
BIT INTO THE SOUTHERN CWFA...POPS MAY HAVE TO BE ADDED TO THE
FORECAST. THE NAM IS DRY AND THE GFS IS PRODUCING SOME ISOLD SHRA.
THE HRRR IS PRODUCING SOME ISOLD SHRA...BUT HAS BEEN INCONSISTENT ON
PEGGING AN AREA FOR THE AFTERNOON. SO...WILL LEAVE OUT ANY MENTION
OF POPS FOR NOW...BUT WILL KEEP AN EYE ON SUCCESSIVE RUNS OF THE
HRRR. POPS SHOULD ALSO REMAIN TOO LOW TO MENTION FOR TUESDAY.
HIGH TEMPS SHOULD REMAIN SLIGHTLY BELOW NORMAL TODAY...BUT BEGIN TO
WARM AS THE RIDGING ALOFT REALLY BEGINS TO BUILD ON TUESDAY.
NLISTEMAA
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
UPPER RIDGING DOMINATES AT THE BEGINNING OF THE EXTENDED AND THIS
WILL KEEP THE AREA DRY. BY THURSDAY THOUGH...AN UPPER LEVEL LOW
PUSHING ACROSS CANADA HELPS TO FORCE THE UPPER LEVEL PATTERN
ACROSS THE CWA INTO NORTHWEST FLOW. AS THIS OCCURS...HAVE A
BACKDOOR FRONT PUSHING TOWARDS THE CWA ON THURSDAY. HAVE GONE
AHEAD AND INTRODUCED A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
ACROSS NORTH GEORGIA ON THURSDAY...A DAY EARLIER THAN PREVIOUSLY
FORECAST. AS THIS FRONT SINKS FURTHER SOUTH ON FRIDAY...HAVE
PUSHED THE SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS FURTHER
SOUTH. BY THE WEEKEND...THE BOUNDARY IS STILL AROUND...HOWEVER IT
WEAKENS. HAVE LEFT OUT THE MENTION OF PRECIP WITH THAT WITH POPS
OF ONLY 10 PERCENT.
STILL FORECASTING ABOVE NORMAL TEMPERATURES WITH HIGHS IN THE
UPPER 80S TO LOWER 90S AT THE END OF THE WEEK.
11
&&
.AVIATION...
06Z UPDATE...
DENSE FOG HAS DEVELOPED ACROSS THE NORTHERN TERMINALS EARLY THIS
MORNING. DO THINK VSBYS WILL BOUNCE FOR THE NEXT COUPLE OF
HOURS...BUT SHOULD SETTLE AROUND 1/4SM BY 8-10Z AND STAY DOWN
UNTIL AN HOUR OR SO AFTER SUNRISE WHEN CIGS SHOULD IMPROVE AND LOW
CIGS SHOULD DISSIPATE. SCT AFT CU SHOULD BE PRESENT IN THE
AFTERNOON. LIGHT EASTERLY FLOW THROUGH THE DAY...WITH SE FLOW
OVERNIGHT AND TOMORROW.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE CIGS/VSBYS. HIGH CONFIDENCE REMAINING ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 76 56 81 64 / 10 10 10 0
ATLANTA 76 59 82 66 / 10 10 10 0
BLAIRSVILLE 71 50 76 58 / 10 10 10 0
CARTERSVILLE 77 58 83 63 / 10 10 10 0
COLUMBUS 81 61 85 67 / 10 10 10 0
GAINESVILLE 74 55 79 64 / 10 10 10 0
MACON 79 58 83 64 / 10 10 10 0
ROME 77 58 84 62 / 10 10 10 0
PEACHTREE CITY 77 57 82 63 / 10 10 10 0
VIDALIA 79 59 83 65 / 10 10 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR THE
FOLLOWING ZONES: BANKS...BARROW...BARTOW...BUTTS...CARROLL...
CATOOSA...CHATTOOGA...CHEROKEE...CLARKE...CLAYTON...COBB...
COWETA...DADE...DAWSON...DEKALB...DOUGLAS...FANNIN...FAYETTE...
FLOYD...FORSYTH...GILMER...GORDON...GREENE...GWINNETT...HALL...
HARALSON...HARRIS...HEARD...HENRY...JACKSON...JASPER...LAMAR...
LUMPKIN...MADISON...MERIWETHER...MONROE...MORGAN...MURRAY...
MUSCOGEE...NEWTON...NORTH FULTON...OCONEE...OGLETHORPE...
PAULDING...PICKENS...PIKE...POLK...PUTNAM...ROCKDALE...SOUTH
FULTON...SPALDING...TALBOT...TALIAFERRO...TOWNS...TROUP...
UNION...UPSON...WALKER...WALTON...WHITE...WHITFIELD...WILKES.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....11
AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS POCATELLO ID
150 PM MDT MON MAY 19 2014
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT.
A LOW PRESSURE SYSTEM OFF THE COAST OF OREGON IS STREAMING MOISTURE
INTO THE REGION. AFTERNOON HEAT OF THE DAY VARIETY STORMS HAVE
DEVELOPED THIS AFTERNOON. THESE STORMS SHOULD LARGELY DIMINISH
DURING THE EVENING. ON TUESDAY THE LOW WILL MOVE INTO SOUTHERN
NEVADA. MOISTURE WILL CONTINUE TO STREAM INTO THE AREA AND AFTERNOON
THUNDERSTORMS WILL DEVELOP AGAIN ON TUESDAY AFTERNOON. SOME OF THIS
ACTIVITY WILL DIMINISH DURING THE EVENING. HOWEVER SOME CONVECTION
WILL PERSIST THROUGH THE NIGHT BECAUSE OF THE PROXIMITY OF THE LOW
TO THE REGION.
WEDNESDAY IS EXPECTED TO BE ANOTHER ACTIVE AFTERNOON WITH SCATTERED
SHOWERS AND THUNDERSTORMS AS THE CUTOFF LOW SPINS ALONG THE NV AND UT
BORDER. HOWEVER...EARLY THURSDAY THE LOW WILL BEGIN TO DRIFT SOUTH
AND LEAVE SE ID IN A DRIER SPLIT FLOW. EXPECT SLIGHT CHANCES FOR
SHOWERS AND THUNDERSTORMS ON THURSDAY TO REMAIN IN THE CENTRAL
MOUNTAINS AT BEST.
VALLE/EP
.LONG TERM...FRIDAY THROUGH NEXT MONDAY. NO MAJOR CHANGES IN CURRENT
FORECAST FOR THE LONG TERM. SOME DISAGREEMENT BETWEEN GFS/ECMWF OVER
UPPER PATTERN THROUGH THE WEEKEND. WHILE BOTH MODELS DEPICT A CUTOFF
LOW OVER AZ/NM...THE ECMWF DEPICTS UPPER TROUGHING IN THE NORTHERN
BRANCH OF THE SPLIT FLOW. GFS SHOWS MORE A WEST-SOUTHWESTERLY FLOW
IN THE UPPER LEVELS AND IS SHOWING MUCH DRIER CONDITIONS. MODELS
COME A LITTLE BETTER INTO PHASE MONDAY WITH DEEPENING TROUGH OFF THE
WA/OR COAST WITH GFS TIMING SLIGHTLY FASTER. HINSBERGER
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL WITH DRY AIR IN THE
LOW-LEVELS. THUNDERSTORMS REMAIN A CONCERN THIS AFTERNOON/EVENING IN
THE CENTRAL IDAHO MOUNTAINS. HRRR HINTING AT CONVECTION REACHING AS
FAR SOUTH AS KIDA THIS AFTERNOON...BUT NOT ENOUGH CERTAINTY TO
INCLUDE IN TAF. HINSBERGER
&&
.FIRE WEATHER...AN UPPER LOW ALONG THE WEST COAST WILL RESULT IN A
MOIST SOUTHWEST FLOW OVER IDAHO TODAY. SCATTERED SHOWERS AND A FEW
THUNDERSTORMS ARE EXPECTED OVER THE CENTRAL IDAHO MOUNTAINS AND
UPPER SNAKE HIGHLANDS TODAY...WITH MORE ISOLATED COVERAGE ELSEWHERE.
TEMPERATURES WILL BE COOLER AND HUMIDITY HIGHER. THE UPPER LOW MOVES
INTO THE GREAT BASIN TUESDAY...INCREASING THE COVERAGE OF SHOWERS
AND THUNDERSTORMS. THE UPPER LOW WILL REMAIN A DOMINANT FEATURE
THROUGH MUCH OF THE WEEK...WITH SHOWERS AND COOL TEMPERATURES.
HEDGES
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
113 PM CDT MON MAY 19 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CONCERN IS WITH THUNDER CHANCES TONIGHT THROUGH
WEDNESDAY EVENING AND HOW WARM TEMPERATURES GET TUESDAY AND
WEDNESDAY. THE PRIMARY FOCUS FOR CONVECTIVE POTENTIAL IS THE LATE
TUESDAY PERIOD WHEN THE BEST COMBINATION OF INSTABILITY AND DEEP
LAYER SHEAR EXISTS.
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...
A LOOK AT THE BIG PICTURE ON W/V THIS MORNING SHOWS DIGGING UPPER
TROUGH ALONG WEST COAST AND ANOTHER TROUGH NEAR EAST COAST CAUSING
DEVELOPING RIDGING OVER THE CENTRAL CONUS. A SHORT WAVE AND DECENT
LOW LEVEL JET OVER IOWA WAS CAUSING SCT SHRA ACTIVITY AND EVEN A
ROGUE LIGHTNING STRIKE. AT THE SURFACE...RELATIVELY DEEP LOW
PRESSURE IS LOCATED ACROSS THE NORTHERN HIGH PLAINS...WITH EXPANSIVE
HIGH PRESSURE ACROSS THE EASTERN OH VALLEY DOWN TO THE GULF COAST.
AS A RESULT...THERE IS ONLY A NARROW RIBBON OF MOISTURE RETURN INTO
THE IMMEDIATE LA AND TX GULF COAST.
TODAY AND TONIGHT...
AS THE IA SHORTWAVE SHIFTS EAST THIS MORNING...IT WILL ENCOUNTER AN
INCREASINGLY DRY AIR MASS OVER THE AREA SO DO NOT EXPECT PRECIP TO
REACH GROUND OVER CWA DESPITE APPEARANCE ON RADAR. CANNOT RULE OUT A
FEW ISOLATED SPRINKLES. CONTINUED WARM ADVECTION AND GUSTY SOUTHERLY WINDS
WILL ENABLE ANOTHER SEASONABLY MILD DAY BUT WARMING LIKELY TO BE
TEMPERED SOME BY CONTINUED INCREASING MID AND HIGH CLOUDS. THUS
UPPER 60S TO AROUND 70 LOOKS TO DO IT FOR HIGHS...THOUGH WIND
BACKING TO SOUTHEAST ALONG IL SHORE LIKELY TO KEEP READINGS A BIT
COOLER THERE. ANOTHER WAVE IS LIKELY TO APPROACH DURING MID-LATE
AFTERNOON AND CONTINUE TO INDICATE SLIGHT CHANCE POPS FOR NORTHERN
TIER. SIMILAR SITUATION WITH RADAR ECHOES LIKELY TO BE PRESENT
ROUGHLY I-80 AND NORTH FOR A TIME BUT VERY DRY LOW LEVELS. WENT
AHEAD AND MENTIONED ISOLATED SPRINKLES IN GRIDS. STRONG LOW LEVEL
JET AND TEMPERATURE ADVECTION THIS EVENING PLUS MINOR CONVERGENCE ON
NOSE OF JET COULD SUPPORT SOME SHRA BUT PRIMARY FOCUS CONTINUES TO
REMAIN TO THE NORTH OF CWA AND CHANCE POPS ALONG WI BORDER. WITH
STEEP MIDLEVEL LAPSE RATES ALSO BEING ADVECTED INTO AREA...ELEVATED
INSTABILITY SUPPORTS A SLIGHT CHANCE THUNDER MENTION. A MILD NIGHT
IS IN STORE DUE TO CLOUDS...SOUTHERLY FLOW AND VERY STRONG WARM
ADVECTION...WITH UPPER 50S-LOW 60S.
TUESDAY AND TUESDAY NIGHT...
A WARM FRONT FROM PLAINS LOW WILL LIFT NORTH THROUGH AREA BY THE
MORNING AND ALL CONVECTIVE ACTIVITY LOOKS TO BE WELL NORTH OF CWA BY
THAT TIME. SOME CONCERNS WITH CLOUD COVER BUT ASIDE FROM 00Z NAM12
SOLUTION...CAP FROM EML LOOKS TO HOLD STRONG UNTIL LIKELY LATER IN
THE DAY. 850 MB TEMPS IN MID TEENS CELSIUS AND H925 APPROACHING 20C
SHOULD SUPPORT HIGHS IN LOW-MID 80S...IF NOT WARMER SHOULD THERE BE
MORE SUNSHINE. CONTINUE TO HAVE CONCERNS WITH LEVEL OF MOISTURE
RETURN SHOWN BY MOST GUIDANCE AND HAVE TRENDED DEWPOINTS TOWARD
LOWER MOS BASED GUIDANCE. THUS ONLY EXPECTING MAX DEWPOINTS IN THE
LOWER 60S...WHICH WILL RESULT IN SLIGHTLY LOWER MLCAPE VALUES. BDRY
LAYER CONVERGENCE COULD INCREASE ENOUGH BY LATE AFTERNOON MAINLY IN
THE FAR NORTH FOR ISOLATED TO SCT CONVECTION INITIATION. EVENING
LOOKS TO BE MORE LIKELY TIMEFRAME FOR SCATTERED CONVECTION (LOW-MID
CHANCE POPS) DUE TO IMPROVING WEST TO EAST ORIENTED CONVERGENCE AS SLOW
MOVING COLD FRONT APPROACHES. DEEP LAYER SHEAR OF 45 TO 50 KT WOULD
SUPPORT AN ISOLATED STRONG TO SEVERE THREAT WITH WIND AND HAIL MAIN
CONCERN DUE TO VERY MEAGER LL SHEAR. SETUP STILL DOES NOT APPEAR TO
FAVOR WIDESPREAD TSTMS AND SEVERE THREAT AS FORCING IS NOT ALL THAT
STRONG AND OVERALL INSTABILITY CONCERNS. ANY TSTM COVERAGE SHOULD
DIMINISH SOME OVERNIGHT AS CAPE WANES.
WEDNESDAY AND WEDNESDAY NIGHT...
SLOW MOVING COLD FRONT WILL CONTINUE TO SAG SOUTH. DIURNAL MINIMUM
OF INSTABILITY SHOULD RESULT IN LOW COVERAGE AT BEST OF SHRA AND
ONLY A SLIGHT TSRA THREAT FOCUSED MAINLY SOUTH OF I-80 IN THE
MORNING. A SLIGHTLY BETTER CHANCE EXISTS IN AFTERNOON OVER FAR
SOUTHERN CWA AS DEWPOINTS IN LOW-MID 60S AND TEMPERATURES WARMING
INTO THE LOWER AND MID 80S SHOULD ENABLE MORE THAN SUFFICIENT FOR
STORMS TO FORM. MAIN QUESTION IS WILL REGENERATION OF CONVECTION
BE OVER OR SOUTH OF SOUTHERN CWA. DEEP LAYER SHEAR WILL AGAIN BE
NEAR OR EVEN OVER 50 KT...SUPPORTING STORM ORGANIZATION AND SEVERE
WIND AND HAIL THREAT IN THE FAR SOUTH...WHICH SPC HAS INCLUDED IN
A DAY 3 SLIGHT RISK. TO THE NORTH OF FRONTAL BOUNDARY...AIR MASS
WILL GRADUALLY BE BECOMING LESS HUMID AS DRIER AIR FILTERS
IN...BUT WEDNESDAY LOOKS TO BE ANOTHER WARM DAY AS 850 AND 925 MB
TEMPS DO NOT COOL MUCH AT ALL FROM TUESDAY. THUS AROUND 80 OR LOW
80S APPEARS LIKELY. ALSO THINKING THAT DUE TO DECENT WEST-
NORTHWEST GRADIENT LAKE BREEZE WIND SHIFT IS NOT LIKELY TO OCCUR
UNTIL EARLY EVENING IF AT ALL FOR ILLINOIS SHORE AND PERHAPS MID
AFTERNOON ALONG INDIANA SHORE.
LONG TERM...THURSDAY THROUGH SUNDAY
A LARGE SURFACE ANTICYCLONE PARKING OVER THE GREAT LAKES WILL
DOMINATE OUR WEATHER INTO THE HOLIDAY WEEKEND. PERSISTENT ONSHORE
FLOW WILL KEEP THE LAKEFRONT COOLER UNTIL PERHAPS SUNDAY AND
TEMPERATURES INLAND WARMING FROM SEASONABLE TO A BIT ABOVE NORMAL
OVER THE WEEKEND. PRECIP CHANCES LIKELY TO REMAIN SOUTH OF THE AREA
DUE TO INFLUENCE OF THE SURFACE HIGH. ALL IN ALL...SIGNS POINT TO A
FANTASTIC MEMORIAL DAY WEEKEND FOR OUTDOOR ACTIVITIES.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* VARIABLE WINDS IN THE 160 TO 200 DEGREE RANGE LIKELY BECOMING
STEADIER 160-180 DEGREES EARLY THIS AFTERNOON. GUSTS 20-25 KT
BECOMING MORE FREQUENT...CONTINUING INTO THE EVENING.
* SLIGHT CHANCE FOR SHRA/ISOLD TSRA THIS EVENING...WITH SOME
CHANCE OVERNIGHT.
* POTENTIAL FOR LLWS OVERNIGHT WITH WINDS INCREASING TO AROUND 45
KT TOWARD 2000 FT AGL.
* SOUTH WINDS EARLY TUESDAY MORNING BECOMING SOUTHWEST BY MID
MORNING.
MDB
//DISCUSSION...UPDATED 18Z...
HIGH PRESSURE OVER EASTERN OHIO CONTINUES TO SLOWLY MOVE EASTWARD
ALLOWING THE PRESSURE GRADIENT TO SLOWLY TIGHTEN ACROSS THE
TERMINALS. ABUNDANT CLOUD COVER HAS LIKELY BEEN KEEPING GUST
FREQUENCY LOW BUT EXPECT IT TO INCREASE THROUGH THE AFTERNOON.
WIND DIRECTION DETAILS CONTINUE TO BE A CHALLENGE ACROSS THE
CHICAGO TERMINALS RANGING FROM 130 TO 230 DEGREES OVER THE LAST
HOUR OR TWO WITH MOST OBS SHOWING 160-200 DEGREES. EXPECT THAT
THIS VARIABILITY WILL DECREASE THROUGH THE EARLY AFTERNOON WITH A
STEADIER 160-180 DIRECTION TAKING OVER. GUSTS WILL CONTINUE TO
RANGE IN THE 20-25 KT RANGE THOUGH AM A LITTLE CONCERNED THAT
THERE COULD BE SOME 25+ KT GUSTS TOWARDS RFD LATE THIS AFTERNOON.
GUSTS WILL LIKELY CONTINUE INTO THE OVERNIGHT...THOUGH FREQUENCY
MAY DROP OFF. WINDS LOOK TO TURN SOUTH THEN SOUTHWEST TUESDAY
MORNING.
BAND OF WEAKENING LIGHT RAIN CONTINUES TO MOVE EAST ACROSS NE
IL/NW IN WITH ANOTHER SHORTWAVE TRACKING ACROSS EASTERN IOWA.
FOCUS FOR SHRA/TSRA IS STILL FAVORED NORTH OF THE TERMINALS THIS
AFTERNOON WITH THIS NEXT WAVE BUT THE SOUTHERN EXTENT MAY REACH
RFD SO WILL CONTINUE WITH VCSH MENTION THERE. THERE IS SOME CHANCE
AT ORD/MDW/DPA/GYY COULD SEE SOME ISOLD/SCT ACTIVITY THIS EVENING
BUT THE CHANCE IS TOO LOW TO INCLUDE IN THE TAF. ANOTHER WEAK WAVE
MAY PASS NORTH OF THE AREA OVERNIGHT BRINGING ANOTHER MINIMAL CHANCE
FOR SHRA/TSRA. FAIRLY CONFIDENT THAT THE THREAT OVERNIGHT IS LOW
BUT WILL KEEP AN EYE ON IT.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN WIND DIRECTION VARIABILITY DECREASING THIS
AFTERNOON. HIGH CONFIDENCE IN GUSTS.
* MEDIUM-HIGH CONFIDENCE THAT SHRA/TSRA CHANCE THIS EVENING IS
LOW. MEDIUM CONFIDENCE THAT THE CHANCE IS LOW OVERNIGHT.
* LOW CONFIDENCE IN LLWS POTENTIAL...MAY BE MARGINAL.
* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS TUESDAY.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...CHANCE FOR SCATTERED GUSTY TSRA.
WEDNESDAY...VFR LIKELY.
THURSDAY-SUNDAY...MAINLY VFR. EASTERLY WIND COMPONENT LIKELY MUCH
OF THIS TIME.
MTF
&&
.MARINE...
228 AM CDT
AS HIGH PRESSURE HOLDS ITS OWN ACROSS THE OHIO RIVER VALLEY TODAY
INTO THIS EVENING...THE PRESSURE GRADIENT ACROSS THE LAKE WILL
INCREASE WITH LOW PRESSURE MOVING EAST INTO THE UPPER PLAINS. THE
STRENGTHENING SOUTHERLY TO SOUTHEASTERLY FLOW WILL BE CLOSE TO SMALL
CRAFT ADVISORY CRITERIA THIS AFTERNOON AND TONIGHT ALONG THE
ILLINOIS AND INDIANA NEARSHORE ZONES. THIS INCLUDES FORECAST FOUR TO
MAYBE EVEN FIVE FOOT WAVES THIS EVE ALONG THE LAKE COUNTY IL
SHORE. HAVE OPTED TO HOLD OFF ON AN ADVISORY ISSUANCE FOR RIGHT
NOW AS THE CURRENT WIND/WAVE RANGE FORECAST IS SLIGHTLY BELOW
CRITERIA MOST OF THE TIME THIS AFTERNOON AND TONIGHT. OVER THE
OPEN WATER...THE HIGHEST WINDS LOOK TO BE TONIGHT INTO VERY EARLY
TUESDAY MORNING...WITH SOME 25-28 KT GUSTS PROBABLE OVER THE
NORTHERN TWO-THIRDS. THE LOW PRESSURE WILL MOVE TO LAKE SUPERIOR
LATE TUESDAY NIGHT AND BRING A COLD FRONT ACROSS THE LAKE AS IT
DOES SUCH. THE STRONGER FRONT WILL PASS LATE WEDNESDAY INTO
WEDNESDAY EVENING WHICH WILL TURN WINDS NORTHERLY. HIGH PRESSURE
WILL THEN PREVAIL DURING THE FRIDAY-SATURDAY TIME FRAME.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740...7 PM MONDAY TO 10 AM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1244 PM CDT Mon May 19 2014
.DISCUSSION...
ISSUED 1037 AM CDT Mon May 19 2014
Light sprinkles and showers passed over the nrn portion of the
state this morning as a high pressure ridge drifts eastward.
Slightly cooler max temp forecast holding well, and hourly grids
also looking pretty good. Mostly mid level clouds across the area
helping to keep those temps down. Not a lot of change expected for
the forecast and though grids will be freshened up this morning,
an update is mostly unnecessary. Will send updated zones for
morning language closer to noon.
&&
.AVIATION...
ISSUED 1234 PM CDT Mon May 19 2014
High pressure ridge slipping to the east today, leaving southerly
flow across Illinois. VFR through the forecast with confidence
dwindling in the pre dawn hours. BKN mid deck main cloud cover for
the remainder of the day. Some indication of increasing RH in the
lower levels resulting in a BKN045 group for this evening and
overnight. Issues with the forecast increase after midnight as the
MOS guidance and models diverge with handling of llvl moisture.
Majority of models maintain a mid deck. Just a few hint at 025
level/MVFR early. With some stratocu to the SW at this level and
sat imagery pushing that moisture east/northeast... cannot
discount. For now, starting the trend for MVFR potential with SCT
mention in for morning.
HJS
&&
.PREV DISCUSSION...
ISSUED 252 AM CDT Mon May 19 2014
SHORT TERM...Today through Wednesday
High pressure currently centered over Ohio continues to control
the weather across central Illinois early this morning: however,
WAA cloud cover and even a few light showers are poised just to
the west across Iowa. 07z/2am KDVN radar imagery shows scattered
echoes approaching the Mississippi River, with a few upstream
surface obs reporting sprinkles. This activity is pushing away
from 45-50kt LLJ positioned over the central Plains, so am not
expecting any measurable precip to reach the KILX CWA. Even still,
given upstream radar imagery and the most recent HRRR suggesting a
few showers tracking into north-central Illinois this morning,
have opted to include scattered sprinkles along/north of a
Rushville to Bloomington line. Aside from the sprinkles, skies
will be partly to mostly cloudy today as warm advection regime
overspreads the area. Due to cloud cover and a southeasterly flow,
warming trend will be tempered, with afternoon highs mainly in the
lower 70s.
Surface winds will veer to the southwest and skies will become
mostly sunny on Tuesday, allowing high temperatures to soar well
into the 80s. Meanwhile, an upper-level disturbance tracking along
the U.S./Canadian border will begin to flatten the upper ridge
over the Midwest and push a weak cold front southward toward
Illinois. Several models develop scattered convection along the
advancing front across northern Illinois Tuesday afternoon, with
the NAM being furthest south. Airmass within the warm sector will
remain capped on Tuesday, so think storms will be confined
immediately along the boundary and will stay north of the KILX
CWA.
The front will sag southward into central Illinois on Wednesday,
providing the best chance for widespread precipitation during the
entire forecast period. With dewpoints pooling in the middle to
upper 60s near the boundary, surface based CAPES are progged to
exceed 2500J/kg. In addition, decent 0-6km bulk shear values of
40 to 45kt will support the potential for a few strong to severe
storms with large hail and strong winds Wednesday afternoon and
evening. Main question will be areal coverage of storms, as
convergence along the front will not be particularly strong.
Think scattered thunderstorms will develop, so will carry 30-40
POPs across the board accordingly.
LONG TERM...Thursday through Sunday
Latest model trends continue to push the front south/southwest of
central Illinois by Thursday. WPC progs take the front into the
Deep South by Saturday, but feel this is too far south given
presence of strong upper ridging along the Gulf Coast. Adjusting
the boundary northward would place it from Missouri E/SE into the
Tennessee River Valley from Thursday through Saturday. This
position would keep most of the rain chances out of central
Illinois, except perhaps across the far S/SW CWA in closer
proximity to the front. Further north and east, high pressure will
build into the Great Lakes for the end of the week providing a dry
NE flow and slightly cooler temps in the 70s. Once the high shifts
eastward, whatever remains of the dissipating boundary will return
northward on Sunday. Potentially could see a few showers/storms as
this process occurs, but forcing will be so weak by then that a
POP is not warranted at this time. Instead, will continue with a
dry forecast for Sunday and Monday with high temperatures climbing
back into the 80s.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1108 AM CDT MON MAY 19 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CONCERN IS WITH THUNDER CHANCES TONIGHT THROUGH
WEDNESDAY EVENING AND HOW WARM TEMPERATURES GET TUESDAY AND
WEDNESDAY. THE PRIMARY FOCUS FOR CONVECTIVE POTENTIAL IS THE LATE
TUESDAY PERIOD WHEN THE BEST COMBINATION OF INSTABILITY AND DEEP
LAYER SHEAR EXISTS.
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...
A LOOK AT THE BIG PICTURE ON W/V THIS MORNING SHOWS DIGGING UPPER
TROUGH ALONG WEST COAST AND ANOTHER TROUGH NEAR EAST COAST CAUSING
DEVELOPING RIDGING OVER THE CENTRAL CONUS. A SHORT WAVE AND DECENT
LOW LEVEL JET OVER IOWA WAS CAUSING SCT SHRA ACTIVITY AND EVEN A
ROGUE LIGHTNING STRIKE. AT THE SURFACE...RELATIVELY DEEP LOW
PRESSURE IS LOCATED ACROSS THE NORTHERN HIGH PLAINS...WITH EXPANSIVE
HIGH PRESSURE ACROSS THE EASTERN OH VALLEY DOWN TO THE GULF COAST.
AS A RESULT...THERE IS ONLY A NARROW RIBBON OF MOISTURE RETURN INTO
THE IMMEDIATE LA AND TX GULF COAST.
TODAY AND TONIGHT...
AS THE IA SHORTWAVE SHIFTS EAST THIS MORNING...IT WILL ENCOUNTER AN
INCREASINGLY DRY AIR MASS OVER THE AREA SO DO NOT EXPECT PRECIP TO
REACH GROUND OVER CWA DESPITE APPEARANCE ON RADAR. CANNOT RULE OUT A
FEW ISOLATED SPRINKLES. CONTINUED WARM ADVECTION AND GUSTY SOUTHERLY WINDS
WILL ENABLE ANOTHER SEASONABLY MILD DAY BUT WARMING LIKELY TO BE
TEMPERED SOME BY CONTINUED INCREASING MID AND HIGH CLOUDS. THUS
UPPER 60S TO AROUND 70 LOOKS TO DO IT FOR HIGHS...THOUGH WIND
BACKING TO SOUTHEAST ALONG IL SHORE LIKELY TO KEEP READINGS A BIT
COOLER THERE. ANOTHER WAVE IS LIKELY TO APPROACH DURING MID-LATE
AFTERNOON AND CONTINUE TO INDICATE SLIGHT CHANCE POPS FOR NORTHERN
TIER. SIMILAR SITUATION WITH RADAR ECHOES LIKELY TO BE PRESENT
ROUGHLY I-80 AND NORTH FOR A TIME BUT VERY DRY LOW LEVELS. WENT
AHEAD AND MENTIONED ISOLATED SPRINKLES IN GRIDS. STRONG LOW LEVEL
JET AND TEMPERATURE ADVECTION THIS EVENING PLUS MINOR CONVERGENCE ON
NOSE OF JET COULD SUPPORT SOME SHRA BUT PRIMARY FOCUS CONTINUES TO
REMAIN TO THE NORTH OF CWA AND CHANCE POPS ALONG WI BORDER. WITH
STEEP MIDLEVEL LAPSE RATES ALSO BEING ADVECTED INTO AREA...ELEVATED
INSTABILITY SUPPORTS A SLIGHT CHANCE THUNDER MENTION. A MILD NIGHT
IS IN STORE DUE TO CLOUDS...SOUTHERLY FLOW AND VERY STRONG WARM
ADVECTION...WITH UPPER 50S-LOW 60S.
TUESDAY AND TUESDAY NIGHT...
A WARM FRONT FROM PLAINS LOW WILL LIFT NORTH THROUGH AREA BY THE
MORNING AND ALL CONVECTIVE ACTIVITY LOOKS TO BE WELL NORTH OF CWA BY
THAT TIME. SOME CONCERNS WITH CLOUD COVER BUT ASIDE FROM 00Z NAM12
SOLUTION...CAP FROM EML LOOKS TO HOLD STRONG UNTIL LIKELY LATER IN
THE DAY. 850 MB TEMPS IN MID TEENS CELSIUS AND H925 APPROACHING 20C
SHOULD SUPPORT HIGHS IN LOW-MID 80S...IF NOT WARMER SHOULD THERE BE
MORE SUNSHINE. CONTINUE TO HAVE CONCERNS WITH LEVEL OF MOISTURE
RETURN SHOWN BY MOST GUIDANCE AND HAVE TRENDED DEWPOINTS TOWARD
LOWER MOS BASED GUIDANCE. THUS ONLY EXPECTING MAX DEWPOINTS IN THE
LOWER 60S...WHICH WILL RESULT IN SLIGHTLY LOWER MLCAPE VALUES. BDRY
LAYER CONVERGENCE COULD INCREASE ENOUGH BY LATE AFTERNOON MAINLY IN
THE FAR NORTH FOR ISOLATED TO SCT CONVECTION INITIATION. EVENING
LOOKS TO BE MORE LIKELY TIMEFRAME FOR SCATTERED CONVECTION (LOW-MID
CHANCE POPS) DUE TO IMPROVING WEST TO EAST ORIENTED CONVERGENCE AS SLOW
MOVING COLD FRONT APPROACHES. DEEP LAYER SHEAR OF 45 TO 50 KT WOULD
SUPPORT AN ISOLATED STRONG TO SEVERE THREAT WITH WIND AND HAIL MAIN
CONCERN DUE TO VERY MEAGER LL SHEAR. SETUP STILL DOES NOT APPEAR TO
FAVOR WIDESPREAD TSTMS AND SEVERE THREAT AS FORCING IS NOT ALL THAT
STRONG AND OVERALL INSTABILITY CONCERNS. ANY TSTM COVERAGE SHOULD
DIMINISH SOME OVERNIGHT AS CAPE WANES.
WEDNESDAY AND WEDNESDAY NIGHT...
SLOW MOVING COLD FRONT WILL CONTINUE TO SAG SOUTH. DIURNAL MINIMUM
OF INSTABILITY SHOULD RESULT IN LOW COVERAGE AT BEST OF SHRA AND
ONLY A SLIGHT TSRA THREAT FOCUSED MAINLY SOUTH OF I-80 IN THE
MORNING. A SLIGHTLY BETTER CHANCE EXISTS IN AFTERNOON OVER FAR
SOUTHERN CWA AS DEWPOINTS IN LOW-MID 60S AND TEMPERATURES WARMING
INTO THE LOWER AND MID 80S SHOULD ENABLE MORE THAN SUFFICIENT FOR
STORMS TO FORM. MAIN QUESTION IS WILL REGENERATION OF CONVECTION
BE OVER OR SOUTH OF SOUTHERN CWA. DEEP LAYER SHEAR WILL AGAIN BE
NEAR OR EVEN OVER 50 KT...SUPPORTING STORM ORGANIZATION AND SEVERE
WIND AND HAIL THREAT IN THE FAR SOUTH...WHICH SPC HAS INCLUDED IN
A DAY 3 SLIGHT RISK. TO THE NORTH OF FRONTAL BOUNDARY...AIR MASS
WILL GRADUALLY BE BECOMING LESS HUMID AS DRIER AIR FILTERS
IN...BUT WEDNESDAY LOOKS TO BE ANOTHER WARM DAY AS 850 AND 925 MB
TEMPS DO NOT COOL MUCH AT ALL FROM TUESDAY. THUS AROUND 80 OR LOW
80S APPEARS LIKELY. ALSO THINKING THAT DUE TO DECENT WEST-
NORTHWEST GRADIENT LAKE BREEZE WIND SHIFT IS NOT LIKELY TO OCCUR
UNTIL EARLY EVENING IF AT ALL FOR ILLINOIS SHORE AND PERHAPS MID
AFTERNOON ALONG INDIANA SHORE.
LONG TERM...THURSDAY THROUGH SUNDAY
A LARGE SURFACE ANTICYCLONE PARKING OVER THE GREAT LAKES WILL
DOMINATE OUR WEATHER INTO THE HOLIDAY WEEKEND. PERSISTENT ONSHORE
FLOW WILL KEEP THE LAKEFRONT COOLER UNTIL PERHAPS SUNDAY AND
TEMPERATURES INLAND WARMING FROM SEASONABLE TO A BIT ABOVE NORMAL
OVER THE WEEKEND. PRECIP CHANCES LIKELY TO REMAIN SOUTH OF THE AREA
DUE TO INFLUENCE OF THE SURFACE HIGH. ALL IN ALL...SIGNS POINT TO A
FANTASTIC MEMORIAL DAY WEEKEND FOR OUTDOOR ACTIVITIES.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* VARIABLE SOUTH TO SOUTH-SOUTHWEST WINDS NEXT HOUR OR SO BECOMING
SOUTH-SOUTHEAST WHICH THEN CONTINUE THROUGH TONIGHT. GUSTS
20-25KT MORE FREQUENT BY MIDDAY CONTINUING THROUGH EARLY THIS
EVENING.
* SLIGHT CHANCE FOR LIGHT RAIN/SPRINKLES TODAY AND A SLIGHT CHANCE
FOR SHOWERS AND STORMS TONIGHT.
* POTENTIAL FOR LOW LEVEL WIND SHEAR OVERNIGHT AS WINDS INCREASE
TO 45 KT AROUND 2000 FT AGL.
MDB
//DISCUSSION...UPDATED 16Z...
BRIEF PERIOD OF VARIABLE SOUTH TO SOUTH-SOUTHWEST WINDS HAS SET UP
ACROSS NORTHEAST ILLINOIS WITH SPEEDS INCREASING TO THE 12-15 KT
RANGE WITH GUSTS AROUND 20 KT. THIS DIRECTION IS EXPECTED TO BE
TEMPORARY AND BECOME MORE SOUTH-SOUTHEAST TOWARDS 17Z...AND EVEN
THEN THERE WILL LIKELY BE SOME SOUTH TO SOUTH-SOUTHEAST
VARIABILITY. GUSTS OF 20-25 KT WILL ALSO BECOME SOMEWHAT MORE
FREQUENT...THOUGH ABUNDANCE OF CLOUD COVER MAY KEEP THE FREQUENCY
LOW.
MDB
FROM 12Z...
HIGH PRESSURE ACROSS THE OHIO RIVER VALLEY WILL BEGIN MOVING EAST
TODAY AND WITH THAT WILL COME STRONGER SOUTHERLY WINDS. THESE
SHOULD INCREASE FAIRLY QUICKLY THIS MORNING WITH GUSTS TO 20 KT
PROBABLE BY 15Z-17Z. HAVE UNDERCUT MODEL GUIDANCE SOME FOR WHAT
MAXIMUM GUSTS WOULD BE DUE TO THICKER MID-LEVEL CLOUD COVER
EXPECTED. THE WIND DIRECTION IS FAVORED TO BE SLIGHTLY EAST OF
SOUTH FOR MUCH OF TODAY AND THIS EVENING.
MOISTURE WILL INCREASE ALOFT TODAY AND THIS IS PROMOTING LIGHT
RAIN/SPRINKLES ACROSS NORTHWEST INTO CENTRAL ILLINOIS AS OF 12Z.
THIS ACTIVITY SHOULD BEGIN TO ERODE AS IT MOVES INTO DRIER AIR
OVER NORTHEAST IL. WHILE SOME SPOTTY LIGHT RAIN MAY OCCUR AT TAF
SITES TODAY...NAMELY RFD...IT WILL BE LIGHT AND VFR. THERE IS A
CHANCE FOR SHOWERS AND POSSIBLY SOME THUNDERSTORMS TONIGHT FOR
MAINLY NORTH OF THE TERMINALS...THOUGH AGAIN SOME SHOWER ACTIVITY
MAY BE CLOSE BY. LOWER CLOUDS AROUND 4000-6000FT ARE EXPECTED TO
DEVELOP LATE THIS EVENING AND PERSIST INTO TUESDAY MORNING.
A WIND SHIFT TO SOUTHWEST WILL LIKELY OCCUR SOMETIME FROM SUNRISE
TUESDAY TO THE IMMEDIATE COUPLE HOURS AFTER. WIND SPEEDS WILL
GRADUALLY DIMINISH TUESDAY WITH THE APPROACH OF A SLOW MOVING
FRONT.
MTF
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH THAT WINDS WILL MAINLY BE 150-170 DEGREES TODAY AND THIS
EVENING.
* HIGH THAT IF ANY RAIN OCCURS TODAY IT WILL BE LIGHT AND
TEMPORARY. LOW ON WHETHER ANY SHOWERS WILL OCCUR TONIGHT.
* LOW CONFIDENCE IN WHETHER LOW LEVEL WIND SHEAR WILL
DEVELOP...SURFACE WINDS MAY BE TOO STRONG.
* MEDIUM IN TIMING OF WIND SHIFT TO SOUTHWEST TUESDAY MORNING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...CHANCE FOR SCATTERED GUSTY TSRA.
WEDNESDAY...VFR LIKELY.
THURSDAY-SUNDAY...MAINLY VFR. EASTERLY WIND COMPONENT LIKELY MUCH
OF THIS TIME.
MTF
&&
.MARINE...
228 AM CDT
AS HIGH PRESSURE HOLDS ITS OWN ACROSS THE OHIO RIVER VALLEY TODAY
INTO THIS EVENING...THE PRESSURE GRADIENT ACROSS THE LAKE WILL
INCREASE WITH LOW PRESSURE MOVING EAST INTO THE UPPER PLAINS. THE
STRENGTHENING SOUTHERLY TO SOUTHEASTERLY FLOW WILL BE CLOSE TO SMALL
CRAFT ADVISORY CRITERIA THIS AFTERNOON AND TONIGHT ALONG THE
ILLINOIS AND INDIANA NEARSHORE ZONES. THIS INCLUDES FORECAST FOUR TO
MAYBE EVEN FIVE FOOT WAVES THIS EVE ALONG THE LAKE COUNTY IL
SHORE. HAVE OPTED TO HOLD OFF ON AN ADVISORY ISSUANCE FOR RIGHT
NOW AS THE CURRENT WIND/WAVE RANGE FORECAST IS SLIGHTLY BELOW
CRITERIA MOST OF THE TIME THIS AFTERNOON AND TONIGHT. OVER THE
OPEN WATER...THE HIGHEST WINDS LOOK TO BE TONIGHT INTO VERY EARLY
TUESDAY MORNING...WITH SOME 25-28 KT GUSTS PROBABLE OVER THE
NORTHERN TWO-THIRDS. THE LOW PRESSURE WILL MOVE TO LAKE SUPERIOR
LATE TUESDAY NIGHT AND BRING A COLD FRONT ACROSS THE LAKE AS IT
DOES SUCH. THE STRONGER FRONT WILL PASS LATE WEDNESDAY INTO
WEDNESDAY EVENING WHICH WILL TURN WINDS NORTHERLY. HIGH PRESSURE
WILL THEN PREVAIL DURING THE FRIDAY-SATURDAY TIME FRAME.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740...7 PM MONDAY TO 10 AM TUESDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1045 AM CDT Mon May 19 2014
.DISCUSSION...
ISSUED 1037 AM CDT Mon May 19 2014
Light sprinkles and showers passed over the nrn portion of the
state this morning as a high pressure ridge drifts eastward.
Slightly cooler max temp forecast holding well, and hourly grids
also looking pretty good. Mostly mid level clouds across the area
helping to keep those temps down. Not a lot of change expected for
the forecast and though grids will be freshened up this morning,
an update is mostly unnecessary. Will send updated zones for
morning language closer to noon.
HJS
&&
.AVIATION...
ISSUED 650 AM CDT Mon May 19 2014
Isolated light showers will affect the central IL airports except
SPI into mid morning due to warm air advection pattern. Isolated
thunderstorms should stay north of PIA this morning. VFR
conditions still expected to prevail through tonight despite the
isolated showers this morning. Like yesterday morning the patchy
shallow ground fog will stay southeast of I-70 near the Wabash
river until mid morning. Broken to overcast mid level clouds to
affect central IL today with ceilings lowering to 4-7k ft during
this evening. South to southeast winds 5-10 kts early this morning
to increase to 12-18 kts by 15Z/10 am with gusts 22-27 kts from
late this morning into this evening. Have winds veering south at
10-15 kts overnight. 1029 mb high pressure over WV and eastern Ohio
was ridging westward across IN into eastern IL. 999 mb low
pressure over western ND and central SD and eastern CO will push a
frontal boundary se into central KS/IA by 12Z/7 am Tue. Increasing
pressure gradient over central IL today to create the gusty sse
winds. Isolated to scattered convection to stay north of I-80
tonight closer to frontal boundary.
07
&&
.PREV DISCUSSION...
ISSUED 252 AM CDT Mon May 19 2014
SHORT TERM...Today through Wednesday
High pressure currently centered over Ohio continues to control
the weather across central Illinois early this morning: however,
WAA cloud cover and even a few light showers are poised just to
the west across Iowa. 07z/2am KDVN radar imagery shows scattered
echoes approaching the Mississippi River, with a few upstream
surface obs reporting sprinkles. This activity is pushing away
from 45-50kt LLJ positioned over the central Plains, so am not
expecting any measurable precip to reach the KILX CWA. Even still,
given upstream radar imagery and the most recent HRRR suggesting a
few showers tracking into north-central Illinois this morning,
have opted to include scattered sprinkles along/north of a
Rushville to Bloomington line. Aside from the sprinkles, skies
will be partly to mostly cloudy today as warm advection regime
overspreads the area. Due to cloud cover and a southeasterly flow,
warming trend will be tempered, with afternoon highs mainly in the
lower 70s.
Surface winds will veer to the southwest and skies will become
mostly sunny on Tuesday, allowing high temperatures to soar well
into the 80s. Meanwhile, an upper-level disturbance tracking along
the U.S./Canadian border will begin to flatten the upper ridge
over the Midwest and push a weak cold front southward toward
Illinois. Several models develop scattered convection along the
advancing front across northern Illinois Tuesday afternoon, with
the NAM being furthest south. Airmass within the warm sector will
remain capped on Tuesday, so think storms will be confined
immediately along the boundary and will stay north of the KILX
CWA.
The front will sag southward into central Illinois on Wednesday,
providing the best chance for widespread precipitation during the
entire forecast period. With dewpoints pooling in the middle to
upper 60s near the boundary, surface based CAPES are progged to
exceed 2500J/kg. In addition, decent 0-6km bulk shear values of
40 to 45kt will support the potential for a few strong to severe
storms with large hail and strong winds Wednesday afternoon and
evening. Main question will be areal coverage of storms, as
convergence along the front will not be particularly strong.
Think scattered thunderstorms will develop, so will carry 30-40
POPs across the board accordingly.
LONG TERM...Thursday through Sunday
Latest model trends continue to push the front south/southwest of
central Illinois by Thursday. WPC progs take the front into the
Deep South by Saturday, but feel this is too far south given
presence of strong upper ridging along the Gulf Coast. Adjusting
the boundary northward would place it from Missouri E/SE into the
Tennessee River Valley from Thursday through Saturday. This
position would keep most of the rain chances out of central
Illinois, except perhaps across the far S/SW CWA in closer
proximity to the front. Further north and east, high pressure will
build into the Great Lakes for the end of the week providing a dry
NE flow and slightly cooler temps in the 70s. Once the high shifts
eastward, whatever remains of the dissipating boundary will return
northward on Sunday. Potentially could see a few showers/storms as
this process occurs, but forcing will be so weak by then that a
POP is not warranted at this time. Instead, will continue with a
dry forecast for Sunday and Monday with high temperatures climbing
back into the 80s.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
906 AM CDT MON MAY 19 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CONCERN IS WITH THUNDER CHANCES TONIGHT THROUGH
WEDNESDAY EVENING AND HOW WARM TEMPERATURES GET TUESDAY AND
WEDNESDAY. THE PRIMARY FOCUS FOR CONVECTIVE POTENTIAL IS THE LATE
TUESDAY PERIOD WHEN THE BEST COMBINATION OF INSTABILITY AND DEEP
LAYER SHEAR EXISTS.
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...
A LOOK AT THE BIG PICTURE ON W/V THIS MORNING SHOWS DIGGING UPPER
TROUGH ALONG WEST COAST AND ANOTHER TROUGH NEAR EAST COAST CAUSING
DEVELOPING RIDGING OVER THE CENTRAL CONUS. A SHORT WAVE AND DECENT
LOW LEVEL JET OVER IOWA WAS CAUSING SCT SHRA ACTIVITY AND EVEN A
ROGUE LIGHTNING STRIKE. AT THE SURFACE...RELATIVELY DEEP LOW
PRESSURE IS LOCATED ACROSS THE NORTHERN HIGH PLAINS...WITH EXPANSIVE
HIGH PRESSURE ACROSS THE EASTERN OH VALLEY DOWN TO THE GULF COAST.
AS A RESULT...THERE IS ONLY A NARROW RIBBON OF MOISTURE RETURN INTO
THE IMMEDIATE LA AND TX GULF COAST.
TODAY AND TONIGHT...
AS THE IA SHORTWAVE SHIFTS EAST THIS MORNING...IT WILL ENCOUNTER AN
INCREASINGLY DRY AIR MASS OVER THE AREA SO DO NOT EXPECT PRECIP TO
REACH GROUND OVER CWA DESPITE APPEARANCE ON RADAR. CANNOT RULE OUT A
FEW ISOLATED SPRINKLES. CONTINUED WARM ADVECTION AND GUSTY SOUTHERLY WINDS
WILL ENABLE ANOTHER SEASONABLY MILD DAY BUT WARMING LIKELY TO BE
TEMPERED SOME BY CONTINUED INCREASING MID AND HIGH CLOUDS. THUS
UPPER 60S TO AROUND 70 LOOKS TO DO IT FOR HIGHS...THOUGH WIND
BACKING TO SOUTHEAST ALONG IL SHORE LIKELY TO KEEP READINGS A BIT
COOLER THERE. ANOTHER WAVE IS LIKELY TO APPROACH DURING MID-LATE
AFTERNOON AND CONTINUE TO INDICATE SLIGHT CHANCE POPS FOR NORTHERN
TIER. SIMILAR SITUATION WITH RADAR ECHOES LIKELY TO BE PRESENT
ROUGHLY I-80 AND NORTH FOR A TIME BUT VERY DRY LOW LEVELS. WENT
AHEAD AND MENTIONED ISOLATED SPRINKLES IN GRIDS. STRONG LOW LEVEL
JET AND TEMPERATURE ADVECTION THIS EVENING PLUS MINOR CONVERGENCE ON
NOSE OF JET COULD SUPPORT SOME SHRA BUT PRIMARY FOCUS CONTINUES TO
REMAIN TO THE NORTH OF CWA AND CHANCE POPS ALONG WI BORDER. WITH
STEEP MIDLEVEL LAPSE RATES ALSO BEING ADVECTED INTO AREA...ELEVATED
INSTABILITY SUPPORTS A SLIGHT CHANCE THUNDER MENTION. A MILD NIGHT
IS IN STORE DUE TO CLOUDS...SOUTHERLY FLOW AND VERY STRONG WARM
ADVECTION...WITH UPPER 50S-LOW 60S.
TUESDAY AND TUESDAY NIGHT...
A WARM FRONT FROM PLAINS LOW WILL LIFT NORTH THROUGH AREA BY THE
MORNING AND ALL CONVECTIVE ACTIVITY LOOKS TO BE WELL NORTH OF CWA BY
THAT TIME. SOME CONCERNS WITH CLOUD COVER BUT ASIDE FROM 00Z NAM12
SOLUTION...CAP FROM EML LOOKS TO HOLD STRONG UNTIL LIKELY LATER IN
THE DAY. 850 MB TEMPS IN MID TEENS CELSIUS AND H925 APPROACHING 20C
SHOULD SUPPORT HIGHS IN LOW-MID 80S...IF NOT WARMER SHOULD THERE BE
MORE SUNSHINE. CONTINUE TO HAVE CONCERNS WITH LEVEL OF MOISTURE
RETURN SHOWN BY MOST GUIDANCE AND HAVE TRENDED DEWPOINTS TOWARD
LOWER MOS BASED GUIDANCE. THUS ONLY EXPECTING MAX DEWPOINTS IN THE
LOWER 60S...WHICH WILL RESULT IN SLIGHTLY LOWER MLCAPE VALUES. BDRY
LAYER CONVERGENCE COULD INCREASE ENOUGH BY LATE AFTERNOON MAINLY IN
THE FAR NORTH FOR ISOLATED TO SCT CONVECTION INITIATION. EVENING
LOOKS TO BE MORE LIKELY TIMEFRAME FOR SCATTERED CONVECTION (LOW-MID
CHANCE POPS) DUE TO IMPROVING WEST TO EAST ORIENTED CONVERGENCE AS SLOW
MOVING COLD FRONT APPROACHES. DEEP LAYER SHEAR OF 45 TO 50 KT WOULD
SUPPORT AN ISOLATED STRONG TO SEVERE THREAT WITH WIND AND HAIL MAIN
CONCERN DUE TO VERY MEAGER LL SHEAR. SETUP STILL DOES NOT APPEAR TO
FAVOR WIDESPREAD TSTMS AND SEVERE THREAT AS FORCING IS NOT ALL THAT
STRONG AND OVERALL INSTABILITY CONCERNS. ANY TSTM COVERAGE SHOULD
DIMINISH SOME OVERNIGHT AS CAPE WANES.
WEDNESDAY AND WEDNESDAY NIGHT...
SLOW MOVING COLD FRONT WILL CONTINUE TO SAG SOUTH. DIURNAL MINIMUM
OF INSTABILITY SHOULD RESULT IN LOW COVERAGE AT BEST OF SHRA AND
ONLY A SLIGHT TSRA THREAT FOCUSED MAINLY SOUTH OF I-80 IN THE
MORNING. A SLIGHTLY BETTER CHANCE EXISTS IN AFTERNOON OVER FAR
SOUTHERN CWA AS DEWPOINTS IN LOW-MID 60S AND TEMPERATURES WARMING
INTO THE LOWER AND MID 80S SHOULD ENABLE MORE THAN SUFFICIENT FOR
STORMS TO FORM. MAIN QUESTION IS WILL REGENERATION OF CONVECTION
BE OVER OR SOUTH OF SOUTHERN CWA. DEEP LAYER SHEAR WILL AGAIN BE
NEAR OR EVEN OVER 50 KT...SUPPORTING STORM ORGANIZATION AND SEVERE
WIND AND HAIL THREAT IN THE FAR SOUTH...WHICH SPC HAS INCLUDED IN
A DAY 3 SLIGHT RISK. TO THE NORTH OF FRONTAL BOUNDARY...AIR MASS
WILL GRADUALLY BE BECOMING LESS HUMID AS DRIER AIR FILTERS
IN...BUT WEDNESDAY LOOKS TO BE ANOTHER WARM DAY AS 850 AND 925 MB
TEMPS DO NOT COOL MUCH AT ALL FROM TUESDAY. THUS AROUND 80 OR LOW
80S APPEARS LIKELY. ALSO THINKING THAT DUE TO DECENT WEST-
NORTHWEST GRADIENT LAKE BREEZE WIND SHIFT IS NOT LIKELY TO OCCUR
UNTIL EARLY EVENING IF AT ALL FOR ILLINOIS SHORE AND PERHAPS MID
AFTERNOON ALONG INDIANA SHORE.
LONG TERM...THURSDAY THROUGH SUNDAY
A LARGE SURFACE ANTICYCLONE PARKING OVER THE GREAT LAKES WILL
DOMINATE OUR WEATHER INTO THE HOLIDAY WEEKEND. PERSISTENT ONSHORE
FLOW WILL KEEP THE LAKEFRONT COOLER UNTIL PERHAPS SUNDAY AND
TEMPERATURES INLAND WARMING FROM SEASONABLE TO A BIT ABOVE NORMAL
OVER THE WEEKEND. PRECIP CHANCES LIKELY TO REMAIN SOUTH OF THE AREA
DUE TO INFLUENCE OF THE SURFACE HIGH. ALL IN ALL...SIGNS POINT TO A
FANTASTIC MEMORIAL DAY WEEKEND FOR OUTDOOR ACTIVITIES.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* SOUTH TO SOUTH-SOUTHEAST WINDS THROUGH TONIGHT...AND AT TIMES
GUSTING 20-25KT BY MIDDAY CONTINUING THROUGH EARLY THIS EVENING.
* SLIGHT CHANCE FOR LIGHT RAIN/SPRINKLES TODAY AND A SLIGHT CHANCE
FOR SHOWERS AND STORMS TONIGHT.
* POTENTIAL FOR LOW LEVEL WIND SHEAR OVERNIGHT AS WINDS INCREASE
TO 45 KT AROUND 2000 FT AGL.
MDB
//DISCUSSION...UPDATED 14Z...
BAND OF LIGHT RAIN SHOWERS CONTINUES TO MOVE EASTWARD ACROSS NORTH
CENTRAL ILLINOIS NEAR RFD. THERE HAS BEEN SOME MINIMAL NEW
REGENERATION ALONG THE WESTERN PORTION OF THE BAND BUT THE EASTERN
FLANK CONTINUALLY ERODES AS IT MOVES INTO DRIER AIR. OVERALL THINK
THAT THE THREAT FOR ANY MEASURABLE RAINFALL AT ORD/MDW/DPA/GYY IS
MINIMAL THOUGH SOME SPRINKLES COULD MAKE THEIR WAY THROUGH BY
MIDDAY. SOUTH-SOUTHEAST WINDS WILL HAVE INCREASED INTO THE 8-12 KT
RANGE BUT STEADY GUSTS OVER 20 KT LOOK TO BE DELAYED A BIT LIKELY
DUE TO THE EXTENSIVE MID/HIGH CLOUD COVER. DO EXPECT THAT THERE
WILL BE AN INCREASE IN GUSTS TO 20 KT LATE THIS MORNING HOWEVER.
MDB
FROM 12Z...
HIGH PRESSURE ACROSS THE OHIO RIVER VALLEY WILL BEGIN MOVING EAST
TODAY AND WITH THAT WILL COME STRONGER SOUTHERLY WINDS. THESE
SHOULD INCREASE FAIRLY QUICKLY THIS MORNING WITH GUSTS TO 20 KT
PROBABLE BY 15Z-17Z. HAVE UNDERCUT MODEL GUIDANCE SOME FOR WHAT
MAXIMUM GUSTS WOULD BE DUE TO THICKER MID-LEVEL CLOUD COVER
EXPECTED. THE WIND DIRECTION IS FAVORED TO BE SLIGHTLY EAST OF
SOUTH FOR MUCH OF TODAY AND THIS EVENING.
MOISTURE WILL INCREASE ALOFT TODAY AND THIS IS PROMOTING LIGHT
RAIN/SPRINKLES ACROSS NORTHWEST INTO CENTRAL ILLINOIS AS OF 12Z.
THIS ACTIVITY SHOULD BEGIN TO ERODE AS IT MOVES INTO DRIER AIR
OVER NORTHEAST IL. WHILE SOME SPOTTY LIGHT RAIN MAY OCCUR AT TAF
SITES TODAY...NAMELY RFD...IT WILL BE LIGHT AND VFR. THERE IS A
CHANCE FOR SHOWERS AND POSSIBLY SOME THUNDERSTORMS TONIGHT FOR
MAINLY NORTH OF THE TERMINALS...THOUGH AGAIN SOME SHOWER ACTIVITY
MAY BE CLOSE BY. LOWER CLOUDS AROUND 4000-6000FT ARE EXPECTED TO
DEVELOP LATE THIS EVENING AND PERSIST INTO TUESDAY MORNING.
A WIND SHIFT TO SOUTHWEST WILL LIKELY OCCUR SOMETIME FROM SUNRISE
TUESDAY TO THE IMMEDIATE COUPLE HOURS AFTER. WIND SPEEDS WILL
GRADUALLY DIMINISH TUESDAY WITH THE APPROACH OF A SLOW MOVING
FRONT.
MTF
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH THAT WINDS WILL MAINLY BE 150-170 DEGREES TODAY AND THIS
EVENING.
* HIGH THAT IF ANY RAIN OCCURS TODAY IT WILL BE LIGHT AND
TEMPORARY. LOW ON WHETHER ANY SHOWERS WILL OCCUR TONIGHT.
* LOW CONFIDENCE IN WHETHER LOW LEVEL WIND SHEAR WILL
DEVELOP...SURFACE WINDS MAY BE TOO STRONG.
* MEDIUM IN TIMING OF WIND SHIFT TO SOUTHWEST TUESDAY MORNING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...CHANCE FOR SCATTERED GUSTY TSRA.
WEDNESDAY...VFR LIKELY.
THURSDAY-SUNDAY...MAINLY VFR. EASTERLY WIND COMPONENT LIKELY MUCH
OF THIS TIME.
MTF
&&
.MARINE...
228 AM CDT
AS HIGH PRESSURE HOLDS ITS OWN ACROSS THE OHIO RIVER VALLEY TODAY
INTO THIS EVENING...THE PRESSURE GRADIENT ACROSS THE LAKE WILL
INCREASE WITH LOW PRESSURE MOVING EAST INTO THE UPPER PLAINS. THE
STRENGTHENING SOUTHERLY TO SOUTHEASTERLY FLOW WILL BE CLOSE TO SMALL
CRAFT ADVISORY CRITERIA THIS AFTERNOON AND TONIGHT ALONG THE
ILLINOIS AND INDIANA NEARSHORE ZONES. THIS INCLUDES FORECAST FOUR TO
MAYBE EVEN FIVE FOOT WAVES THIS EVE ALONG THE LAKE COUNTY IL
SHORE. HAVE OPTED TO HOLD OFF ON AN ADVISORY ISSUANCE FOR RIGHT
NOW AS THE CURRENT WIND/WAVE RANGE FORECAST IS SLIGHTLY BELOW
CRITERIA MOST OF THE TIME THIS AFTERNOON AND TONIGHT. OVER THE
OPEN WATER...THE HIGHEST WINDS LOOK TO BE TONIGHT INTO VERY EARLY
TUESDAY MORNING...WITH SOME 25-28 KT GUSTS PROBABLE OVER THE
NORTHERN TWO-THIRDS. THE LOW PRESSURE WILL MOVE TO LAKE SUPERIOR
LATE TUESDAY NIGHT AND BRING A COLD FRONT ACROSS THE LAKE AS IT
DOES SUCH. THE STRONGER FRONT WILL PASS LATE WEDNESDAY INTO
WEDNESDAY EVENING WHICH WILL TURN WINDS NORTHERLY. HIGH PRESSURE
WILL THEN PREVAIL DURING THE FRIDAY-SATURDAY TIME FRAME.
MTF
&&
.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
National Weather Service Lincoln IL
652 AM CDT Mon May 19 2014
.DISCUSSION...
ISSUED 252 AM CDT Mon May 19 2014
SHORT TERM...Today through Wednesday
High pressure currently centered over Ohio continues to control
the weather across central Illinois early this morning: however,
WAA cloud cover and even a few light showers are poised just to
the west across Iowa. 07z/2am KDVN radar imagery shows scattered
echoes approaching the Mississippi River, with a few upstream
surface obs reporting sprinkles. This activity is pushing away
from 45-50kt LLJ positioned over the central Plains, so am not
expecting any measurable precip to reach the KILX CWA. Even still,
given upstream radar imagery and the most recent HRRR suggesting a
few showers tracking into north-central Illinois this morning,
have opted to include scattered sprinkles along/north of a
Rushville to Bloomington line. Aside from the sprinkles, skies
will be partly to mostly cloudy today as warm advection regime
overspreads the area. Due to cloud cover and a southeasterly flow,
warming trend will be tempered, with afternoon highs mainly in the
lower 70s.
Surface winds will veer to the southwest and skies will become
mostly sunny on Tuesday, allowing high temperatures to soar well
into the 80s. Meanwhile, an upper-level disturbance tracking along
the U.S./Canadian border will begin to flatten the upper ridge
over the Midwest and push a weak cold front southward toward
Illinois. Several models develop scattered convection along the
advancing front across northern Illinois Tuesday afternoon, with
the NAM being furthest south. Airmass within the warm sector will
remain capped on Tuesday, so think storms will be confined
immediately along the boundary and will stay north of the KILX
CWA.
The front will sag southward into central Illinois on Wednesday,
providing the best chance for widespread precipitation during the
entire forecast period. With dewpoints pooling in the middle to
upper 60s near the boundary, surface based CAPES are progged to
exceed 2500J/kg. In addition, decent 0-6km bulk shear values of
40 to 45kt will support the potential for a few strong to severe
storms with large hail and strong winds Wednesday afternoon and
evening. Main question will be areal coverage of storms, as
convergence along the front will not be particularly strong.
Think scattered thunderstorms will develop, so will carry 30-40
POPs across the board accordingly.
LONG TERM...Thursday through Sunday
Latest model trends continue to push the front south/southwest of
central Illinois by Thursday. WPC progs take the front into the
Deep South by Saturday, but feel this is too far south given
presence of strong upper ridging along the Gulf Coast. Adjusting
the boundary northward would place it from Missouri E/SE into the
Tennessee River Valley from Thursday through Saturday. This
position would keep most of the rain chances out of central
Illinois, except perhaps across the far S/SW CWA in closer
proximity to the front. Further north and east, high pressure will
build into the Great Lakes for the end of the week providing a dry
NE flow and slightly cooler temps in the 70s. Once the high shifts
eastward, whatever remains of the dissipating boundary will return
northward on Sunday. Potentially could see a few showers/storms as
this process occurs, but forcing will be so weak by then that a
POP is not warranted at this time. Instead, will continue with a
dry forecast for Sunday and Monday with high temperatures climbing
back into the 80s.
BARNES
&&
.AVIATION...
ISSUED 650 AM CDT Mon May 19 2014
Isolated light showers will affect the central IL airports except
SPI into mid morning due to warm air advection pattern. Isolated
thunderstorms should stay north of PIA this morning. VFR
conditions still expected to prevail through tonight despite the
isolated showers this morning. Like yesterday morning the patchy
shallow ground fog will stay southeast of I-70 near the Wabash
river until mid morning. Broken to overcast mid level clouds to
affect central IL today with ceilings lowering to 4-7k ft during
this evening. South to southeast winds 5-10 kts early this morning
to increase to 12-18 kts by 15Z/10 am with gusts 22-27 kts from
late this morning into this evening. Have winds veering south at
10-15 kts overnight. 1029 mb high pressure over WV and eastern Ohio
was ridging westward across IN into eastern IL. 999 mb low
pressure over western ND and central SD and eastern CO will push a
frontal boundary se into central KS/IA by 12Z/7 am Tue. Increasing
pressure gradient over central IL today to create the gusty sse
winds. Isolated to scattered convection to stay north of I-80
tonight closer to frontal boundary.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
336 AM CDT MON MAY 19 2014
.DISCUSSION...
336 AM CDT
PRIMARY FORECAST CONCERN IS WITH THUNDER CHANCES TONIGHT THROUGH
WEDNESDAY EVENING AND HOW WARM TEMPERATURES GET TUESDAY AND
WEDNESDAY. THE PRIMARY FOCUS FOR CONVECTIVE POTENTIAL IS THE LATE
TUESDAY PERIOD WHEN THE BEST COMBINATION OF INSTABILITY AND DEEP
LAYER SHEAR EXISTS.
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...
A LOOK AT THE BIG PICTURE ON W/V THIS MORNING SHOWS DIGGING UPPER
TROUGH ALONG WEST COAST AND ANOTHER TROUGH NEAR EAST COAST CAUSING
DEVELOPING RIDGING OVER THE CENTRAL CONUS. A SHORT WAVE AND DECENT
LOW LEVEL JET OVER IOWA WAS CAUSING SCT SHRA ACTIVITY AND EVEN A
ROGUE LIGHTNING STRIKE. AT THE SURFACE...RELATIVELY DEEP LOW
PRESSURE IS LOCATED ACROSS THE NORTHERN HIGH PLAINS...WITH EXPANSIVE
HIGH PRESSURE ACROSS THE EASTERN OH VALLEY DOWN TO THE GULF COAST.
AS A RESULT...THERE IS ONLY A NARROW RIBON OF MOISTURE RETURN INTO
THE IMMEDIATE LA AND TX GULF COAST.
TODAY AND TONIGHT...
AS THE IA SHORTWAVE SHIFTS EAST THIS MORNING...IT WILL ENCOUNTER AN
INCREASINGLY DRY AIR MASS OVER THE AREA SO DO NOT EXPECT PRECIP TO
REACH GROUND OVER CWA DESPITE APPEARANCE ON RADAR. CANNOT RULE OUT A
FEW ISOLATED SPRINKLES. CONTINUED WARM ADVECTION AND GUSTY SOUTHERLY WINDS
WILL ENABLE ANOTHER SEASONABLY MILD DAY BUT WARMING LIKELY TO BE
TEMPERED SOME BY CONTINUED INCREASING MID AND HIGH CLOUDS. THUS
UPPER 60S TO AROUND 70 LOOKS TO DO IT FOR HIGHS...THOUGH WIND
BACKING TO SOUTHEAST ALONG IL SHORE LIKELY TO KEEP READINGS A BIT
COOLER THERE. ANOTHER WAVE IS LIKELY TO APPROACH DURING MID-LATE
AFTERNOON AND CONTINUE TO INDICATE SLIGHT CHANCE POPS FOR NORTHERN
TIER. SIMILAR SITUATION WITH RADAR ECHOES LIKELY TO BE PRESENT
ROUGHLY I-80 AND NORTH FOR A TIME BUT VERY DRY LOW LEVELS. WENT
AHEAD AND MENTIONED ISOLATED SPRINKLES IN GRIDS. STRONG LOW LEVEL
JET AND TEMPERATURE ADVECTION THIS EVENING PLUS MINOR CONVERGENCE ON
NOSE OF JET COULD SUPPORT SOME SHRA BUT PRIMARY FOCUS CONTINUES TO
REMAIN TO THE NORTH OF CWA AND CHANCE POPS ALONG WI BORDER. WITH
STEEP MIDLEVEL LAPSE RATES ALSO BEING ADVECTED INTO AREA...ELEVATED
INSTABILITY SUPPORTS A SLIGHT CHANCE THUNDER MENTION. A MILD NIGHT
IS IN STORE DUE TO CLOUDS...SOUTHERLY FLOW AND VERY STRONG WARM
ADVECTION...WITH UPPER 50S-LOW 60S.
TUESDAY AND TUESDAY NIGHT...
A WARM FRONT FROM PLAINS LOW WILL LIFT NORTH THROUGH AREA BY THE
MORNING AND ALL CONVECTIVE ACTIVITY LOOKS TO BE WELL NORTH OF CWA BY
THAT TIME. SOME CONCERNS WITH CLOUD COVER BUT ASIDE FROM 00Z NAM12
SOLUTION...CAP FROM EML LOOKS TO HOLD STRONG UNTIL LIKELY LATER IN
THE DAY. 850 MB TEMPS IN MID TEENS CELSIUS AND H925 APPROACHING 20C
SHOULD SUPPORT HIGHS IN LOW-MID 80S...IF NOT WARMER SHOULD THERE BE
MORE SUNSHINE. CONTINUE TO HAVE CONCERNS WITH LEVEL OF MOISTURE
RETURN SHOWN BY MOST GUIDANCE AND HAVE TRENDED DEWPOINTS TOWARD
LOWER MOS BASED GUIDANCE. THUS ONLY EXPECTING MAX DEWPOINTS IN THE
LOWER 60S...WHICH WILL RESULT IN SLIGHTLY LOWER MLCAPE VALUES. BDRY
LAYER CONVERGENCE COULD INCREASE ENOUGH BY LATE AFTERNOON MAINLY IN
THE FAR NORTH FOR ISOLATED TO SCT CONVECTION INITIATION. EVENING
LOOKS TO BE MORE LIKELY TIMEFRAME FOR SCATTERED CONVECTION (LOW-MID
CHANCE POPS) DUE TO IMPROVING WEST TO EAST ORIENTED CONVERGENCE AS SLOW
MOVING COLD FRONT APPROACHES. DEEP LAYER SHEAR OF 45 TO 50 KT WOULD
SUPPORT AN ISOLATED STRONG TO SEVERE THREAT WITH WIND AND HAIL MAIN
CONCERN DUE TO VERY MEAGER LL SHEAR. SETUP STILL DOES NOT APPEAR TO
FAVOR WIDESPREAD TSTMS AND SEVERE THREAT AS FORCING IS NOT ALL THAT
STRONG AND OVERALL INSTABILITY CONCERNS. ANY TSTM COVERAGE SHOULD
DIMINISH SOME OVERNIGHT AS CAPE WANES.
WEDNESDAY AND WEDNESDAY NIGHT...
SLOW MOVING COLD FRONT WILL CONTINUE TO SAG SOUTH. DIURNAL MINIMUM
OF INSTABILITY SHOULD RESULT IN LOW COVERAGE AT BEST OF SHRA AND
ONLY A SLIGHT TSRA THREAT FOCUSED MAINLY SOUTH OF I-80 IN THE
MORNING. A SLIGHTLY BETTER CHANCE EXISTS IN AFTERNOON OVER FAR
SOUTHERN CWA AS DEWPOINTS IN LOW-MID 60S AND TEMPERATURES WARMING
INTO THE LOWER AND MID 80S SHOULD ENABLE SUFFICIENT CAPE FOR STORMS
TO FORM. MAIN QUESTION IS WILL REGENERATION BE OVER OR SOUTH OF
SOUTHERN CWA. TO THE NORTH OF BOUNDARY...AIR MASS WILL GRADUALLY BE
BECOMING LESS HUMID AS DRIER AIR FILTERS IN...BUT WEDNESDAY LOOKS TO
BE A VERY WARM DAY AS 850 AND 925 MB TEMPS DO NOT COOL MUCH AT ALL
FROM TUESDAY. THUS AROUND 80 OR LOW 80S APPEARS LIKELY. ALSO
THINKING THAT DUE TO DECENT WESTERLY GRADIENT LAKE BREEZE FLIP NOT
LIKELY TO OCCUR UNTIL EARLY EVENING FOR ILLINOIS AND PERHAPS MID
AFTERNOON ALONG IN SHORE.
LONG TERM...THURSDAY THROUGH SUNDAY
A LARGE SURFACE ANTICYCLONE PARKING OVER THE GREAT LAKES WILL
DOMINATE OUR WEATHER INTO THE HOLIDAY WEEKEND. PERSISTENT ONSHORE
FLOW WILL KEEP THE LAKEFRONT COOLER UNTIL PERHAPS SUNDAY AND
TEMPERATURES INLAND WARMING FROM SEASONABLE TO A BIT ABOVE NORMAL
OVER THE WEEKEND. PRECIP CHANCES LIKELY TO REMAIN SOUTH OF THE AREA
DUE TO INFLUENCE OF THE SURFACE HIGH. ALL IN ALL...SIGNS POINT TO A
FANTASTIC MEMORIAL DAY WEEKEND FOR OUTDOOR ACTIVITIES.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SOUTH TO SOUTH-SOUTHEAST WINDS GUSTING 20-25KT LATE THIS MORNING
THROUGH THE EVENING.
* SMALL CHANCE FOR LIGHT RAIN LATE THIS AFTERNOON AND TONIGHT.
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE ACROSS THE OHIO RIVER VALLEY WILL BEGIN MOVING EAST
TODAY AND WITH THAT WILL COME STRONGER SOUTHERLY WINDS. THESE
SHOULD INCREASE FAIRLY QUICKLY AFTER SUNRISE WITH GUSTS TO 20 KT
POSSIBLE BY MID MORNING AND LIKELY BY 16Z-17Z. WITH PRESSURE FALLS
ENVELOPING THE AREA AND DEEPER MIXING...THE WIND DIRECTION IS
FAVORED TO BE SLIGHTLY EAST OF SOUTH MORE OFTEN THAN NOT FOR MUCH
OF TODAY AND THIS EVENING. MOISTURE WILL INCREASE ALOFT THIS
MORNING AND ESPECIALLY THIS AFTERNOON. SCATTERED RADAR ECHOES ARE
LIKELY BY MID MORNING...HOWEVER THE LOW-LEVEL AIR IS ANTICIPATED
TO BE DRY ENOUGH FOR MAINLY VIRGA THROUGH MIDDAY. SOME LIGHT RAIN
IS POSSIBLE BY AFTERNOON INTO EARLY EVENING. RFD IS THE AIRPORT
SLIGHTLY MORE FAVORED TO SEE SOME OF THIS IN NORTHERN IL. THERE IS
A CHANCE FOR THUNDERSTORMS TONIGHT FOR AREAS MAINLY NORTH OF THE
TERMINALS AS WARM AND MOIST AIR CONTINUE TO ADVECT OVER THE AREA
ALOFT. LOWER BUT STILL VFR CLOUDS AROUND 4000-6000FT ARE EXPECTED
TO DEVELOP OVERNIGHT AND PERSIST INTO TUESDAY MORNING.
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH THAT WINDS WILL BE MAINLY 160-180 IN DIRECTION FROM 15Z
ONWARD.
* HIGH THAT IF ANY RAIN DOES OCCUR AT THE AIRFIELDS IT WILL BE
LIGHT AND CONDITIONS WILL REMAIN VFR.
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...CHANCE OF TSRA LATE AFTERNOON INTO THE EVENING.
WEDNESDAY THROUGH SATURDAY...PRIMARILY VFR.
MTF/IZZI
&&
.MARINE...
228 AM CDT
AS HIGH PRESSURE HOLDS ITS OWN ACROSS THE OHIO RIVER VALLEY TODAY
INTO THIS EVENING...THE PRESSURE GRADIENT ACROSS THE LAKE WILL
INCREASE WITH LOW PRESSURE MOVING EAST INTO THE UPPER PLAINS. THE
STRENGTHENING SOUTHERLY TO SOUTHEASTERLY FLOW WILL BE CLOSE TO SMALL
CRAFT ADVISORY CRITERIA THIS AFTERNOON AND TONIGHT ALONG THE
ILLINOIS AND INDIANA NEARSHORE ZONES. THIS INCLUDES FORECAST FOUR TO
MAYBE EVEN FIVE FOOT WAVES THIS EVE ALONG THE LAKE COUNTY IL
SHORE. HAVE OPTED TO HOLD OFF ON AN ADVISORY ISSUANCE FOR RIGHT
NOW AS THE CURRENT WIND/WAVE RANGE FORECAST IS SLIGHTLY BELOW
CRITERIA MOST OF THE TIME THIS AFTERNOON AND TONIGHT. OVER THE
OPEN WATER...THE HIGHEST WINDS LOOK TO BE TONIGHT INTO VERY EARLY
TUESDAY MORNING...WITH SOME 25-28 KT GUSTS PROBABLE OVER THE
NORTHERN TWO-THIRDS. THE LOW PRESSURE WILL MOVE TO LAKE SUPERIOR
LATE TUESDAY NIGHT AND BRING A COLD FRONT ACROSS THE LAKE AS IT
DOES SUCH. THE STRONGER FRONT WILL PASS LATE WEDNESDAY INTO
WEDNESDAY EVENING WHICH WILL TURN WINDS NORTHERLY. HIGH PRESSURE
WILL THEN PREVAIL DURING THE FRIDAY-SATURDAY TIME FRAME.
MTF
&&
.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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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
252 AM CDT Mon May 19 2014
.DISCUSSION...
ISSUED 252 AM CDT Mon May 19 2014
SHORT TERM...Today through Wednesday
High pressure currently centered over Ohio continues to control
the weather across central Illinois early this morning: however,
WAA cloud cover and even a few light showers are poised just to
the west across Iowa. 07z/2am KDVN radar imagery shows scattered
echoes approaching the Mississippi River, with a few upstream
surface obs reporting sprinkles. This activity is pushing away
from 45-50kt LLJ positioned over the central Plains, so am not
expecting any measurable precip to reach the KILX CWA. Even still,
given upstream radar imagery and the most recent HRRR suggesting a
few showers tracking into north-central Illinois this morning,
have opted to include scattered sprinkles along/north of a
Rushville to Bloomington line. Aside from the sprinkles, skies
will be partly to mostly cloudy today as warm advection regime
overspreads the area. Due to cloud cover and a southeasterly flow,
warming trend will be tempered, with afternoon highs mainly in the
lower 70s.
Surface winds will veer to the southwest and skies will become
mostly sunny on Tuesday, allowing high temperatures to soar well
into the 80s. Meanwhile, an upper-level disturbance tracking along
the U.S./Canadian border will begin to flatten the upper ridge
over the Midwest and push a weak cold front southward toward
Illinois. Several models develop scattered convection along the
advancing front across northern Illinois Tuesday afternoon, with
the NAM being furthest south. Airmass within the warm sector will
remain capped on Tuesday, so think storms will be confined
immediately along the boundary and will stay north of the KILX
CWA.
The front will sag southward into central Illinois on Wednesday,
providing the best chance for widespread precipitation during the
entire forecast period. With dewpoints pooling in the middle to
upper 60s near the boundary, surface based CAPES are progged to
exceed 2500J/kg. In addition, decent 0-6km bulk shear values of
40 to 45kt will support the potential for a few strong to severe
storms with large hail and strong winds Wednesday afternoon and
evening. Main question will be areal coverage of storms, as
convergence along the front will not be particularly strong.
Think scattered thunderstorms will develop, so will carry 30-40
POPs across the board accordingly.
LONG TERM...Thursday through Sunday
Latest model trends continue to push the front south/southwest of
central Illinois by Thursday. WPC progs take the front into the
Deep South by Saturday, but feel this is too far south given
presence of strong upper ridging along the Gulf Coast. Adjusting
the boundary northward would place it from Missouri E/SE into the
Tennessee River Valley from Thursday through Saturday. This
position would keep most of the rain chances out of central
Illinois, except perhaps across the far S/SW CWA in closer
proximity to the front. Further north and east, high pressure will
build into the Great Lakes for the end of the week providing a dry
NE flow and slightly cooler temps in the 70s. Once the high shifts
eastward, whatever remains of the dissipating boundary will return
northward on Sunday. Potentially could see a few showers/storms as
this process occurs, but forcing will be so weak by then that a
POP is not warranted at this time. Instead, will continue with a
dry forecast for Sunday and Monday with high temperatures climbing
back into the 80s.
Barnes
&&
.AVIATION...
ISSUED 1151 PM CDT Sun May 18 2014
VFR conditions expected through 06Z TAF valid time. Southerly flow
will increase, becoming quite gusty at times Monday, as the
pressure gradient increases ahead of a developing low pressure
system in the plains. LLWS may develop after sunset Monday
depending on the degree of surface decoupling that occurs, but
have not included it for now considering its potential arrival
only a couple hours from the end of the period. An upper level
disturbance passing near the area after daybreak Monday will
provide low to mid-level cloud cigs, but no precipitation is
anticipated.
Bak
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1027 PM EDT TUE MAY 20 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 344 PM EDT TUE MAY 20 2014
A FRONTAL SYSTEM WILL BRING CHANCES FOR THUNDERSTORMS TO CENTRAL
INDIANA STARTING LATE TONIGHT ACROSS THE NORTH AND SPREADING SOUTH
WEDNESDAY AS A COLD FRONT SINKS SOUTH THROUGH THE AREA. THE BEST
CHANCES FOR SEVERE STORMS WITH THIS SYSTEM WILL BE WEDNESDAY
AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT
THURSDAY USHERING IN DRY WEATHER WITH IT FOR THE REMAINDER OF THE
PERIOD.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 940 PM EDT TUE MAY 20 2014
SCATTERED CONVECTION HAS BEEN OCCURRING ACROSS NORTHERN ILLINOIS BACK
INTO IOWA OVER THE PAST FEW HOURS. THIS EVENING/S UPPER AIR
INDICATES RATHER WEAK DEEP LAYER SHEAR ACROSS THE AREA...ALTHOUGH
MID LEVEL LAPSE RATES ARE VERY STEEP. SO FAR...HAVEN/T SEEN ANY
INDICATION OF A CONSOLIDATING COLD POOL FROM THE CONVECTION OFF TO
THE NORTH...ALTHOUGH SHORT TERM MODEL DATA SUGGEST A POTENTIAL
OUTFLOW MOVING INTO THE NORTHERN ZONES AFTER MIDNIGHT. STILL UNCLEAR
AS TO WHETHER CONVECTION WILL BUILD SOUTH INTO THE AREA LATER
TONIGHT. 850MB FLOW INTO THE CONVECTIVE AREA IS DECENT...BUT NOT
PARTICULARLY STRONG.
WILL KEEP CHANCE POPS GOING OVER THE NORTHERN HALF OF THE AREA
TONIGHT...BUT WILL BACK OFF ON THE TIMING UNTIL AFTER MIDNIGHT.
PREVIOUS DISCUSSION FOLLOWS.
SOME UNCERTAINTY STILL EXISTS WITH TONIGHT/S FORECAST CONCERNING HOW
FAR SOUTH STORMS WILL GET. SHORT TERM MODEL GUIDANCE WAS TRENDING
DRIER AND PUSHING THE POPS NORTH FOR SEVERAL RUNS THIS MORNING...BUT
LATEST RUNS OF RAP HAVE STARTED BRINGING ECHOES FURTHER SOUTH AND
VERY CLOSE TO THE NORTHERN COUNTIES. THE INFLUENCE OF THE UPPER RIDGE SHOULD
KEEP INITIAL FORMATION WELL NORTH OF THE FORECAST AREA AND EXPECT
CONDITIONS TO REMAIN DRY FOR A TIME AFTER 0Z. BY 6Z HOWEVER COULD
SEE STORMS STARTING TO APPROACH THE NORTHERN COUNTIES...AND WOULD
NOT BE OUT OF THE REALM OF POSSIBILITIES TO SEE AN MCS DEVELOP AND
RIDGE THE THETA E GRADIENT AROUND THE EDGE OF THE UPPER RIDGE WHICH
COULD BRING IT INTO THE NORTHERN/NORTHEASTERN COUNTIES. NAM SEEMS TO
FAVOR DEVELOPMENT A DECENT BIT FURTHER SOUTH THAN OTHER SOLUTIONS
AND GENERALLY DISCOUNTED IT. CONSIDERING THE UNCERTAINTY AND VARIETY
OF SOLUTIONS RIGHT NOW...THINK BEST COURSE OF ACTION IS TO INCLUDE
MID CHANCE POPS ALONG THE NORTHERN TO NORTHEASTERN BORDER AND BRING
A SLIGHT CHANCE DOWN ALONG THE EASTERN BORDER AROUND 9Z THAT RUNS
THROUGH 12Z TO ACCOUNT FOR THE LOW CHANCE OF A RIGHT TURNING MCS
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 344 PM EDT TUE MAY 20 2014
FORECAST FOCUS IS ON CHANCES FOR SEVERE STORMS WEDNESDAY. CIN DROPS
OFF DURING THE DAY ON WEDNESDAY WHILE MLCAPES CLIMB TO OVER 2000
OVER MUCH OF THE FORECAST AREA BY THE AFTERNOON. THE COLD FRONT
SHOULD GET INTO THE NORTHWESTERN COUNTIES AROUND 12-15Z AND START
SINKING SOUTH THROUGH THE AREA...BUT MOVES THROUGH VERY SLOWLY.
0-6 KM BULK SHEAR INCREASES DURING THE AFTERNOON AND...ALONG WITH
THE AFOREMENTIONED INSTABILITY AND FRONTAL FORCING...SHOULD BE
SUFFICIENT TO SUPPORT AN ORGANIZED SEVERE THREAT THAT WILL BE
MAXIMIZED DURING THE 18Z WED-3Z THU TIMEFRAME.
WITH THIS SET OF MODEL RUNS THE FRONT DOES NOT MOVE AS QUICKLY AWAY
FROM THE AREA AND THUS HELD POPS INTO EARLY THURSDAY MORNING
/STILL PRIOR TO 12Z/ IN THE SOUTH. LOOKS LIKE HIGH PRESSURE WILL
BE BUILDING IN ENOUGH TO DRY OUT ALL PRECIP BY 12Z THOUGH AND THEN
WILL KEEP THE WEATHER DRY THROUGH THE SHORT TERM.
FOR TEMPERATURES GUIDANCE WAS CLOSE AND GENERALLY USED A CONSENSUS
EXCEPT FOR WEDNESDAY WHEN FAVORED WARMER MAV NUMBERS BASED ON
CONTINUED STRONG WARM ADVECTION AHEAD OF THE COLD FRONT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 237 PM EDT TUE MAY 20 2014
HOLIDAY WEEKEND LOOKS FANTASTIC WITH WARM DRY WEATHER EXPECTED AS
SURFACE HIGH PRESSURE DRIFTS SLOWLY THROUGH THE OHIO VALLEY.
NORTHERLY FLOW AND WEAK COLD ADVECTION INITIALLY EXPECTED BUT AS
THE CENTER OF THE HIGH SHIFTS EAST OF THE REGION...RETURN FLOW AND
THE ARRIVAL OF AN UPPER RIDGE WILL ENABLE STEADILY WARMING TEMPS
WITH THE POTENTIAL FOR SOME OF THE WARMEST AIR OF THE YEAR SO FAR
TO ARRIVE MONDAY AND TUESDAY. HIGHS IN THE 70S SATURDAY WILL RISE
INTO THE MID 80S BY MONDAY AND TUESDAY WITH SOME HINTS THAT TEMPS
COULD FLIRT WITH THE UPPER 80S IN SOUTHERN COUNTIES.
INCREASING MOISTURE BY MONDAY AND TUESDAY COULD SUPPORT AN
ISOLATED CONVECTIVE THREAT BUT IN THE ABSENCE OF ANY SIGNIFICANT
FORCING UNDER THE RIDGE...BELIEVE CHANCES ARE TOO LOW TO MENTION
AT THIS TIME.
&&
.AVIATION /DISCUSSION FOR THE 210000Z KIND TAF ISSUANCE/...
ISSUED AT 1026 PM EDT TUE MAY 20 2014
0225Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.
GENERALLY LOOKS LIKE VFR CONDITIONS FOR THIS PERIOD...WITH THE
POTENTIAL FOR SOME LOWER FLIGHT CATEGORIES (MFVR) ACROSS THE NRN
SITES SUCH AS KLAF AND KIND...CLOSER TO CONVECTIVE POTENTIAL LATE
TONIGHT INTO EARLY WED.
BASED ON LATEST RADAR MOSAIC AND SHORT RANGE MODEL
GUIDANCE...HAVE BACKED OFF ON MENTIONING ANY VCTS AND CB...SAVE FOR
KIND AND KLAF. KHUF AND KBMG LIKELY TO BE FAR ENOUGH SOUTH (AND
WEST) TO LIMIT ANY IMPACTS FROM A WEAKENING THUNDERSTORM CLUSTER.
MVFR AND LOWER RESTRICTIONS WILL BE POSSIBLE WITHIN THE STORMS
LATE TONIGHT AND WEDNESDAY MORNING.
MODEL SOUNDINGS SUPPORT SOME CLEARING BY MIDDAY WEDNESDAY WITH
WINDS VEERING TO A MORE WESTERLY DIRECTION AS THE COLD FRONT
SETTLES ACROSS CENTRAL INDIANA. RENEWED CONVECTIVE DEVELOPMENT
WEDNESDAY AFTERNOON EXPECTED AFTER 18Z FOCUSED ALONG AND SOUTH OF
I-70. CONFIDENCE IS LOW THIS FAR OUT IN THE FORECAST TO INCLUDE
ANY MENTION OF SHRA OR TS AT THIS TIME. ONLY INDICATED A LOW
STRATUS DECK AROUND 4K FT FOR THE TIME BEING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP/JAS
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
940 PM EDT TUE MAY 20 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 344 PM EDT TUE MAY 20 2014
A FRONTAL SYSTEM WILL BRING CHANCES FOR THUNDERSTORMS TO CENTRAL
INDIANA STARTING LATE TONIGHT ACROSS THE NORTH AND SPREADING SOUTH
WEDNESDAY AS A COLD FRONT SINKS SOUTH THROUGH THE AREA. THE BEST
CHANCES FOR SEVERE STORMS WITH THIS SYSTEM WILL BE WEDNESDAY
AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT
THURSDAY USHERING IN DRY WEATHER WITH IT FOR THE REMAINDER OF THE
PERIOD.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 940 PM EDT TUE MAY 20 2014
SCATTERED CONVECTION HAS BEEN OCCURRING ACROSS NORTHERN ILLINOIS BACK
INTO IOWA OVER THE PAST FEW HOURS. THIS EVENING/S UPPER AIR
INDICATES RATHER WEAK DEEP LAYER SHEAR ACROSS THE AREA...ALTHOUGH
MID LEVEL LAPSE RATES ARE VERY STEEP. SO FAR...HAVEN/T SEEN ANY
INDICATION OF A CONSOLIDATING COLD POOL FROM THE CONVECTION OFF TO
THE NORTH...ALTHOUGH SHORT TERM MODEL DATA SUGGEST A POTENTIAL
OUTFLOW MOVING INTO THE NORTHERN ZONES AFTER MIDNIGHT. STILL UNCLEAR
AS TO WHETHER CONVECTION WILL BUILD SOUTH INTO THE AREA LATER
TONIGHT. 850MB FLOW INTO THE CONVECTIVE AREA IS DECENT...BUT NOT
PARTICULARLY STRONG.
WILL KEEP CHANCE POPS GOING OVER THE NORTHERN HALF OF THE AREA
TONIGHT...BUT WILL BACK OFF ON THE TIMING UNTIL AFTER MIDNIGHT.
PREVIOUS DISCUSSION FOLLOWS.
SOME UNCERTAINTY STILL EXISTS WITH TONIGHT/S FORECAST CONCERNING HOW
FAR SOUTH STORMS WILL GET. SHORT TERM MODEL GUIDANCE WAS TRENDING
DRIER AND PUSHING THE POPS NORTH FOR SEVERAL RUNS THIS MORNING...BUT
LATEST RUNS OF RAP HAVE STARTED BRINGING ECHOES FURTHER SOUTH AND
VERY CLOSE TO THE NORTHERN COUNTIES. THE INFLUENCE OF THE UPPER RIDGE SHOULD
KEEP INITIAL FORMATION WELL NORTH OF THE FORECAST AREA AND EXPECT
CONDITIONS TO REMAIN DRY FOR A TIME AFTER 0Z. BY 6Z HOWEVER COULD
SEE STORMS STARTING TO APPROACH THE NORTHERN COUNTIES...AND WOULD
NOT BE OUT OF THE REALM OF POSSIBILITIES TO SEE AN MCS DEVELOP AND
RIDGE THE THETA E GRADIENT AROUND THE EDGE OF THE UPPER RIDGE WHICH
COULD BRING IT INTO THE NORTHERN/NORTHEASTERN COUNTIES. NAM SEEMS TO
FAVOR DEVELOPMENT A DECENT BIT FURTHER SOUTH THAN OTHER SOLUTIONS
AND GENERALLY DISCOUNTED IT. CONSIDERING THE UNCERTAINTY AND VARIETY
OF SOLUTIONS RIGHT NOW...THINK BEST COURSE OF ACTION IS TO INCLUDE
MID CHANCE POPS ALONG THE NORTHERN TO NORTHEASTERN BORDER AND BRING
A SLIGHT CHANCE DOWN ALONG THE EASTERN BORDER AROUND 9Z THAT RUNS
THROUGH 12Z TO ACCOUNT FOR THE LOW CHANCE OF A RIGHT TURNING MCS
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 344 PM EDT TUE MAY 20 2014
FORECAST FOCUS IS ON CHANCES FOR SEVERE STORMS WEDNESDAY. CIN DROPS
OFF DURING THE DAY ON WEDNESDAY WHILE MLCAPES CLIMB TO OVER 2000
OVER MUCH OF THE FORECAST AREA BY THE AFTERNOON. THE COLD FRONT
SHOULD GET INTO THE NORTHWESTERN COUNTIES AROUND 12-15Z AND START
SINKING SOUTH THROUGH THE AREA...BUT MOVES THROUGH VERY SLOWLY.
0-6 KM BULK SHEAR INCREASES DURING THE AFTERNOON AND...ALONG WITH
THE AFOREMENTIONED INSTABILITY AND FRONTAL FORCING...SHOULD BE
SUFFICIENT TO SUPPORT AN ORGANIZED SEVERE THREAT THAT WILL BE
MAXIMIZED DURING THE 18Z WED-3Z THU TIMEFRAME.
WITH THIS SET OF MODEL RUNS THE FRONT DOES NOT MOVE AS QUICKLY AWAY
FROM THE AREA AND THUS HELD POPS INTO EARLY THURSDAY MORNING
/STILL PRIOR TO 12Z/ IN THE SOUTH. LOOKS LIKE HIGH PRESSURE WILL
BE BUILDING IN ENOUGH TO DRY OUT ALL PRECIP BY 12Z THOUGH AND THEN
WILL KEEP THE WEATHER DRY THROUGH THE SHORT TERM.
FOR TEMPERATURES GUIDANCE WAS CLOSE AND GENERALLY USED A CONSENSUS
EXCEPT FOR WEDNESDAY WHEN FAVORED WARMER MAV NUMBERS BASED ON
CONTINUED STRONG WARM ADVECTION AHEAD OF THE COLD FRONT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 237 PM EDT TUE MAY 20 2014
HOLIDAY WEEKEND LOOKS FANTASTIC WITH WARM DRY WEATHER EXPECTED AS
SURFACE HIGH PRESSURE DRIFTS SLOWLY THROUGH THE OHIO VALLEY.
NORTHERLY FLOW AND WEAK COLD ADVECTION INITIALLY EXPECTED BUT AS
THE CENTER OF THE HIGH SHIFTS EAST OF THE REGION...RETURN FLOW AND
THE ARRIVAL OF AN UPPER RIDGE WILL ENABLE STEADILY WARMING TEMPS
WITH THE POTENTIAL FOR SOME OF THE WARMEST AIR OF THE YEAR SO FAR
TO ARRIVE MONDAY AND TUESDAY. HIGHS IN THE 70S SATURDAY WILL RISE
INTO THE MID 80S BY MONDAY AND TUESDAY WITH SOME HINTS THAT TEMPS
COULD FLIRT WITH THE UPPER 80S IN SOUTHERN COUNTIES.
INCREASING MOISTURE BY MONDAY AND TUESDAY COULD SUPPORT AN
ISOLATED CONVECTIVE THREAT BUT IN THE ABSENCE OF ANY SIGNIFICANT
FORCING UNDER THE RIDGE...BELIEVE CHANCES ARE TOO LOW TO MENTION
AT THIS TIME.
&&
.AVIATION /DISCUSSION FOR THE 210000Z KIND TAF ISSUANCE/...
ISSUED AT 641 PM EDT TUE MAY 20 2014
GENERALLY LOOKS LIKE VFR CONDITIONS FOR THIS PERIOD...WITH THE
POTENTIAL FOR SOME LOWER FLIGHT CATEGORIES (MFVR) ACROSS THE NRN
SITES SUCH AS KLAF AND KIND...CLOSER TO CONVECTIVE POTENTIAL LATE
TONIGHT INTO EARLY WED.
BASED ON LATEST RADAR MOSAIC AND SHORT RANGE MODEL
GUIDANCE...HAVE BACKED OFF ON MENTIONING ANY VCTS AND CB...SAVE FOR
KIND AND KLAF. KHUF AND KBMG LIKELY TO BE FAR ENOUGH SOUTH (AND
WEST) TO LIMIT ANY IMPACTS FROM A WEAKENING THUNDERSTORM CLUSTER.
MVFR AND LOWER RESTRICTIONS WILL BE POSSIBLE WITHIN THE STORMS
LATE TONIGHT AND WEDNESDAY MORNING.
MODEL SOUNDINGS SUPPORT SOME CLEARING BY MIDDAY WEDNESDAY WITH
WINDS VEERING TO A MORE WESTERLY DIRECTION AS THE COLD FRONT
SETTLES ACROSS CENTRAL INDIANA. RENEWED CONVECTIVE DEVELOPMENT
WEDNESDAY AFTERNOON EXPECTED AFTER 18Z FOCUSED ALONG AND SOUTH OF
I-70. CONFIDENCE IS LOW THIS FAR OUT IN THE FORECAST TO INCLUDE
ANY MENTION OF SHRA OR TS AT THIS TIME. ONLY INDICATED A LOW
STRATUS DECK AROUND 4K FT FOR THE TIME BEING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP/JAS
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
758 PM EDT TUE MAY 20 2014
.SYNOPSIS...
ISSUED AT 343 PM EDT TUE MAY 20 2014
A COLD FRONT WILL SLOWLY SLIP SOUTH INTO THE REGION OVER THE NEXT
24 HOURS. SHOWERS AND THUNDERSTORMS ARE EXPECTED
TONIGHT...ESPECIALLY ACROSS PORTIONS OF LOWER MICHIGAN...NORTHERN
INDIANA AND NORTHWESTERN OHIO WITH SEVERE WEATHER A POSSIBILITY.
THE COLD FRONT WILL MOVE THROUGH ON WEDNESDAY WITH ADDITIONAL
CHANCES OF SHOWERS AND THUNDERSTORMS. LOWS TONIGHT WILL DROP INTO
THE 60S WITH HIGHS WEDNESDAY GENERALLY IN THE LOWER 80S...WITH
LOCALLY COOLER CONDITIONS ALONG THE LAKE.
&&
.UPDATE...
ISSUED AT 750 PM EDT TUE MAY 20 2014
CONVECTION HAS RAPIDLY DEVELOPED THIS EVENING ACROSS IN VICINITY
OF LOW LEVEL TROUGH AXIS FROM EASTERN IOWA INTO FAR SOUTHERN
WISCONSIN. A SECONDARY AREA OF WEAK PREFRONTAL CONVERGENCE HAS
ALSO LED TO A SECONDARY BROKEN LINE OF THUNDERSTORMS ACROSS
NORTHERN ILLINOIS. MODERATE INSTABILITY DEPICTED PER 23Z RAP
ANALYSIS FROM NORTHERN ILLINOIS INTO FAR NORTHERN INDIANA/SOUTHERN
LOWER MICHIGAN WITH 100 HPA MLCAPES ON THE ORDER OF 1500-2000
J/KG. AS OF 23Z...STRONGEST DEEP LAYER SHEAR RESIDES NORTH AND
WEST OF LOCAL AREA...BUT POCKET OF STRONGER UPPER LEVEL WESTERLIES
SHOULD OVERSPREAD SOUTHERN GREAT LAKES REGION OVER THE NEXT FEW
HOURS...INCREASING EFFECTIVE SHEAR ACROSS AT LEAST NORTHERN HALF
OF THE AREA. PER SPC MESODISCUSSIONS AND CONVECTIVE
OUTLOOKS...UPSCALE GROWTH STILL OF SOMEWHAT LOW CONFIDENCE GIVEN
LACK OF STRONG MID/UPPER LEVEL FORCING. HOWEVER...COMBINATION OF
MODERATE INSTABILITY AND INCREASING DEEP LAYER EFFECTIVE SHEAR
SHOULD AT LEAST SUPPORT ISOLD SEVERE RISK INTO NORTHWEST PORTIONS
OF THE AREA LATER THIS EVENING CONSIDERING ADDITIONAL OUTFLOW
INTERACTIONS WITH UPSTREAM CONVECTION. HAVE NOT MADE MANY CHANGES
TO PREVIOUS FORECAST WITH ONLY TWEAK TO SHAVE OFF POPS SOME ACROSS
SOUTHEAST HALF OF THE AREA OVER NEXT FEW HOURS. DID NOT MAKE
SUBSTANTIAL CHANGES TO POPS AFTER 03Z WITH SOME CONCERN THAT IF
UPSTREAM CONVECTION CAN CONGEAL...EASTWARD PROPAGATION WILL
ACCELERATE LATER THIS EVENING ACROSS EAST/SOUTHEAST PORTIONS OF
THE FORECAST AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 333 PM EDT TUE MAY 20 2014
...THREAT OF SEVERE WEATHER THIS EVENING...POSSIBLY INTO OVERNIGHT
HOURS...
MAIN FOCUS RESIDES ON COLD FRONT EXTENDING FROM CNTRL LK MI INTO
IOWA WHICH WILL BECOME THE TRIGGER POINT FOR THUNDERSTORMS OVER THE
NEXT COUPLE OF HOURS. CONCERNS LOOM IN EXACTLY HOW THESE STORMS WILL
EVOLVE AND DROP SE TOWARDS THE FORECAST AREA TONIGHT. SPC
MESOANALYSIS SHOWS SFC BASED CAPES 2000 TO 3000 J/KG WERE POOLING
ALONG THE FRONT WITH STEEPENING LAPSE RATES AND INCREASING SHEAR. CU
FIELD HAVE BEEN RATHER SUBDUED THUS FAR ALONG THE FRONT. HOWEVER ALL
HIGH RES MODELS SEEM TO POINT TOWARDS RAPID FORMATION OF STORMS IN
THE 21 TO 23Z TIME FRAME. INITIAL STORM MODE SHOULD BE MULTICELL
CLUSTERS/SOME SUPERCELLS WHICH WILL PRODUCE HAIL AND DAMAGING
WINDS...ALONG WITH SOME TORNADO THREAT. COLD POOL SHOULD BEGIN TO
ESTABLISH WITH CORFIDI VECTORS INDICATED A RAPID FORWARD PROPAGATION
INTO NW PARTS OF THE AREA AFTER 00Z AND OVERSPREADING AT LEAST
NORTHERN HALF THE REMAINDER OF THE EVENING. TIMING OF DAY WILL PLAY
SOMEWHAT AGAINST SEVERE POTENTIAL AS WILL FACT THAT ACTUAL COLD
FRONT WILL RESIDE WELL NW OF THE AREA UNTIL LATER TONIGHT.
HOWEVER...ALL SIGNS CONTINUE TO POINT TOWARDS INCREASING SEVERE
THREAT THIS EVENING...WARRANTING INCREASE IN POPS AND ADDITION OF
SVR WORDING. SOUTHERN EXTENT VERY QUESTIONABLE AS OUTFLOW BOUNDARIES
EVENTUALLY RACE AHEAD OF THE LINE AND ALLOW FOR POTENTIAL FOR THE
LINE TO STALL OUT WITH HRRR INDICATING SOME POTENTIAL FOR ADDITIONAL
DEVELOPMENT ACROSS ILLINOIS/IOWA MOVING IN LATER THIS EVENING. HAVE
NOT ADDED MENTION OF HVY RAIN...BUT TRAINING OF CELLS WILL BE
POSSIBLE WITH INHERENT THREAT FOR FLOODING. WILL DEFER TO EVE SHIFT
TO MONITOR TRENDS.
NO CHANGES TO FORECAST ON WEDNESDAY WITH RESIDUAL BOUNDARY FROM
OVERNIGHT CONVECTION BEING KEY IN CONVECTIVE CHANCES AS ACTUAL COLD
FRONT MOVES IN. NEW DAY2 OUTLOOK HAS SHOVED SLGT RISK A BIT FURTHER
SOUTH ACROSS MAINLY SE THIRD OF THE AREA WHICH IS REASONABLE AT THIS
STAGE. WILL DEFER TO OVERNIGHT SHIFT TO MAKE ADJUSTMENTS.
&&
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 333 PM EDT TUE MAY 20 2014
CDFNT SHOULD BE MOVG THROUGH S-SE PORTION OF CWA AT START OF THE
PERIOD WED EVE. CONVECTION WILL PRBLY HAVE MOVED OUT AHEAD OF THE
FRONT BY 00Z AND BE LOCATED S-SE OF THE CWA, BUT THERE IS A SMALL
CHC OF ACTIVITY CONTG TO DEVELOP ALONG IT, SO MAINTAINED A LOW POP
THROUGH WED EVE. COOLER/DRIER AIRMASS WILL SPREAD INTO THE AREA
BEHIND THE CDFNT BY THURSDAY. SHRTWV MOVG THROUGH THE UPR GRTLKS
TONIGHT/WED EXPECTED TO TRANSITION TO A CUT-OFF LOW OVER NERN
U.S./SE CANADA BY THU WITH ANOTHER CUT-OFF LOW LINGERING OVER THE
SWRN CONUS WHILE IN BETWEEN RIDGE OVER CENTRAL U.S. WILL PROVIDE
OUR AREA WITH FAIR WX LATE THIS WEEK. THESE SYSTEMS EXPECTED TO
MAKE SLOW E-NE PROGRESS OVER THE WEEKEND AND EARLY NEXT WEEK,
LIKELY CONTG THE DRY SPELL ACROSS OUR CWA. TEMPS THU SHOULD BE A
BIT BLO NORMAL, MODIFYING TO WELL ABOVE NORMAL OVER THE HOLIDAY
WEEKEND AS THE UPR RIDGE BUILDS INTO THE AREA. RETURN FLOW WILL
RESULT IN INCREASING LOW LEVEL MOISTURE AND SOME DEVELOPING
INSTABILITY AS SFC HIGH MOVES EAST OF THE AREA BY MONDAY, BUT
PROXIMITY OF UPR LEVEL RIDGE SUGGESTS ANY CONVECTION IN OUR AREA
WILL BE ISOLATED AT BEST, SO FOR NOW HELD OFF ADDING TO FCST.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 750 PM EDT TUE MAY 20 2014
CONVECTION HAS INCREASED OVER THE PAST FEW HOURS IN VICINITY OF
LOW LEVEL FRONT ACROSS EASTERN IOWA AND FAR NORTHERN ILLINOIS.
ADDITIONAL SCATTERED THUNDERSTORMS HAVE DEVELOPED ALONG WEAK
PREFRONTAL CONVERGENCE FEATURE TO THE SOUTH OF THE FRONT. WHILE
MID/UPPER LEVEL FORCING IS RELATIVELY WEAK...EXPECTING ADDITIONAL
SCATTERED THUNDERSTORM DEVELOPMENT...POSSIBLY AFFECTING KSBN AS
EARLY AS 0130-0200Z. HAVE INCLUDED GUSTY NORTHWEST WINDS TO 35
KNOTS WITH THE TSRA AT KSBN GIVEN FAVORABLE THERMODYNAMIC
PROFILES AND UNIDIRECTIONAL NATURE TO FLOW. WILL HOLD OFF ON
HIGHER WIND INCLUSION AT KFWA WITH SOME UNCERTAINTIES PERSISTING
INTO HOW WELL ORGANIZED CONVECTION MAINTAINS ITSELF INTO FAR
NORTHEAST INDIANA LATE EVENING/EARLY OVERNIGHT. ABUNDANT LOW
LEVEL MOISTURE AND WEAK GRADIENT MAY SUPPORT SOME MVFR CONDS EARLY
WEDNESDAY MORNING...WITH TRANSITION BACK TO VFR CONDITIONS BY MID
MORNING. SLOW MOVING NATURE OF FRONT MAY POSE ADDITIONAL
CONVECTIVE RISK WEDNESDAY...PARTICULARLY AT KFWA. HOWEVER WITH
UNCERTAINTIES AS TO HOW CONVECTION TONIGHT WILL IMPACT THE
EFFECTIVE FRONTAL POSITION...WILL HOLD OFF ON ADDITIONAL TS
INCLUSION FOR WEDNESDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...MARSILI
SYNOPSIS...MURPHY/FISHER
SHORT TERM...FISHER
LONG TERM...JT
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
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WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DES MOINES IA
626 PM CDT TUE MAY 20 2014
.SYNOPSIS...
ISSUED AT 302 PM CDT TUE MAY 20 2014
COLD FRONT ACROSS IOWA WILL MOVE SOUTH OF THE STATE BY WED MORNING
AND BECOME STATIONARY TO THE SOUTH. HIGH PRESSURE EXPECTED TO
RIDGE INTO THE NORTH CENTRAL U.S. AND SETTLE OVER THE GREAT LAKES
BY THE WEEKEND. HIGH WILL FINALLY MOVE OFF SUNDAY WITH A
DEVELOPING FRONTAL SYSTEM IN THE ROCKIES MOVING TOWARD THE AREA
SUNDAY AND MONDAY.
&&
.SHORT TERM /TONIGHT/...
ISSUED AT 302 PM CDT TUE MAY 20 2014
BRIEF WINDOW FOR SEVERE CONVECTION LATE AFTERNOON INTO
THE EARLY EVENING HOURS AS STORMS WILL BE HIGHLY DEPENDENT ON
DAYTIME HEATING. FRONT REMAINS LAID UP ACROSS CENTRAL IOWA AND IS
ORIENTED FROM SW IOWA TOWARDS WATERLOO. VERY LITTLE...IF ANY SURFACE
CONVERGENCE OVER CENTRAL IOWA...WITH SOME CONVERGENCE PRESENT ACROSS
SOUTHWEST IOWA. AS OF 19Z...CAP IS BEGINNING TO SHOW SIGNS OF
ERODING AND MUCAPE VALUES HAVE INCREASED TO 2000 J/KG ACROSS
CENTRAL TO SOUTHERN IOWA. HOWEVER...THERE IS ABSOLUTELY NO 0-1KM BULK
SHEAR PRESENT AND THE DEEP LAYER SHEAR IS MARGINAL FOR SUSTAINABLE
UPDRAFTS. DCAPE VALUES RANGE FROM 900 TO 1100 J/KG ALONG AND SOUTH
OF THE FRONT...SO DOWNBURST THREAT IS VIABLE. IF STORMS DO
DEVELOP...STILL ANTICIPATING THE MAIN THREAT TO BE LARGE HAIL AND
DAMAGING WINDS. THE 20.15Z HOPWRF KEEPS CONVECTION INITIATION IN
EASTERN IOWA...WHILE THE 20.17Z HRRR IS MORE BULLISH WITH THE
CONVECTION DEVELOPING OVER WESTERN IOWA. THE SPC 20.12Z 4KM WRF
SEEMED LIKE A DECENT BLEND BETWEEN THE TWO. REGARDLESS...AS
MENTIONED...STORMS WILL BE HIGHLY SUNSHINE DEPENDENT AND NOT
EXPECTING CONVECTION TO LAST MUCH LATER THAN 02Z...WINDOW OF SEVERE
WEATHER OPPORTUNITY WILL BE FROM 21Z TO 02Z. HAVE SEVERE MENTION FOR
LIKELY POPS DURING THE AFOREMENTIONED TIME FRAME AND WENT DRY PAST
06Z TONIGHT FOR THE ENTIRE FORECAST AREA.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 302 PM CDT TUE MAY 20 2014
HIGH PRESSURE WILL NOSE INTO IOWA ON WEDNESDAY AND DOMINATE THE
WEATHER ACROSS THE STATE THROUGH THE REST OF THE WEEK. HIGH IS
LIKELY TO BECOME ANCHORED FOR A WHILE OVER THE COLD GREAT LAKES.
TYPICAL OF THIS TIME OF THE YEAR...BUT EVEN MORE LIKELY THIS YEAR
GIVEN THE COLDER THAN NORMAL WATER TEMPS AND THE PATTERN NOT IN AN
OVERLY PROGRESSIVE STATE.
AS THE HIGH BEGINS TO MOVE OFF AND LOSE ITS INFLUENCE
THUNDERSTORMS THAT WILL BE BRUSHING THE FAR SOUTHWEST PART OF IOWA
WILL BEGIN ADVANCING EAST. MODELS HAVE COME INTO CLOSER AGREEMENT
WITH THE OVERALL PROGRESSION. UPPER LOW WILL IMPINGE ON THE UPPER
RIDGE ADVERTISED IN THE MODELS IS ACCEPTED. A MILD AND WET PERIOD
IS ON TAP LOOKING AT THE BULK OF NEXT WEEK WITH THE SLOW MOVING
UPPER SYSTEM AND A NEGATIVE PNA SETTING UP.
&&
.AVIATION...21/00Z
ISSUED AT 626 PM CDT TUE MAY 20 2014
MAIN CONCERN THIS EVENING WILL BE THE CONVECTION OVER THE THROUGH
04Z. BKN LINE OF STORMS MOVING NORTHEAST AND MAINLY NEAR KDSM...
KALO...AND IF THEY HOLD TOGETHER KOTM. OTHERWISE...MAINLY VFR
CONDITIONS EXPECTED AFT 05Z ONCE CONVECTION MOVES EAST. BY 14-15Z
WED WILL SEE WINDS PICK UP AND GUST TO 17-18KTS NORTH AREAS WITH
LIGHTER GUSTS FROM NORTH ACROSS THE SOUTH. VFR CONDITIONS EXPECTED
THROUGH END OF PERIOD FOR WED WITH MAINLY HIGH CLOUDS IF ANY
ACROSS THE REGION. WILL MONITOR KDSM FOR STRONGER STORMS THROUGH
03Z...THOUGH PRESENT THREAT REMAINS NORTH OF APT AT THIS TIME./REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MS MAY 14
SHORT TERM...PODRAZIK
LONG TERM...MS MAY 14
AVIATION...REV
AREA FORECAST DISCUSSION
NWS TOPEKA KS
622 PM CDT Tue May 20 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Wednesday)
Issued at 314 PM CDT TUE MAY 20 2014
The forecast seems to be unfolding as expected with the latest NAM
forecast soundings showing a capping inversion holding strong over
the area through the afternoon. 19Z water vapor imagery shows a
closed low over central CA with southwesterly flow aloft. There does
not appear to be much in the way of large scale forcing within the
upper flow, and low level convergence along an inverted surface
trough appears to be marginal with not much of a CU field in the
warm sector. The HRRR does try to bring convection off the higher
terrain to the west, but again shows it weakening due to the
elevated mixed layer before it reaches central KS. So expect a dry
forecast heading into Wednesday. Have trended lows tonight a couple
degrees cooler across northern KS. With the trough axis forecast to
pivot more west to east across the forecast area, winds are likely
to become light. This combined with mostly clear skies should allow
for some decent radiational cooling and lows in the lower 60s across
the northern counties. East central KS is likely to stay south of
the trough axis in the warmer air with higher dewpoints so have kept
lows in the mid to upper 60s.
For Wednesday, models are in agreement that the weak boundary will
be across the area with good moisture pooling along it. The NAM and
GFS warm the boundary layer enough so that CAPE values increase to
3000 or 3500 J/kg. They also cool mid levels some so that there is
very little or no CIN by the mid afternoon. Large scale forcing
continues to look unimpressive, but there could be enough
convergence along the boundary for some isolated storms to develop
by the late afternoon. Deep layer shear of 40 to 50 KTS also suggest
that if storms are able to form, they could become supercellular. At
this point low level shear parameters show little or no chance for
tornadoes so main risks with storms that form would be a hail and
wind. Highs Wednesday should not be quite as warm as models weaken
the thermal ridge over the area. Because of this highs are forecast
to be in the middle and upper 80s.
.LONG TERM...(Wednesday Night through Tuesday)
Issued at 314 PM CDT TUE MAY 20 2014
Somewhat above normal thunderstorm chances continue to dominate the
middle and later portions of the forecast. Have shaded chances
slightly up and down when some confidence exists in possible
evolution, but overall confidence on timing and placement of precip
not high.
Wednesday night into Thursday night still present the more dynamic
storm periods with the stationary front keeping some minor
baroclinicity. Any local afternoon storms could easily persist in
the evening hours and keep at least modest severe weather potential,
but highest coverage for overnight Wednesday night into early
Thursday still at least moderately dependent on where convection can
be the most robust and organized to the west. Models differ on
where this will be, but some indications this could be a bit farther
south than earlier anticipated. A rather warm and moist boundary
layer should keep low-level parcels rather buoyant and NAM and GFS
agree with limited CIN through Wednesday night for at least some
severe potential. Synoptic surface high to the northeast and low the
southwest should keep at lest some low-level convergence intact for
Thursday afternoon over the area as long as overnight and early day
convection does not displace the effective front elsewhere. Corfidi
vectors turn more southeast and again may be rather parallel to the
front for overnight convection to again pass through. By Friday
afternoon, more meridional low level flow takes hold for the Central
Plains and should greatly reduce convergence, again barring
MCS-dominated surface features. GFS and ECMWF are rather consistent
with an upper wave emerging from the old trough, but this appears to
be at least partially due to previous convection. Despite weakening
mid-level lapse rates, instability should continue to be at least
modest with good moisture through the column for some storm chances
into Sunday. Better dynamic forcing aloft could commence Sunday
night into Tuesday afternoon if the GFS and ECMWF are correct with
the low finally pushing through, but of course timing ejection of
cut-off lows is difficult at best. Little change in temperatures is
forecast, but again highs will be greatly impacted by any persistent
MCS that persists.
&&
.AVIATION...(For the 00Z TAFs through 00Z Wednesday Evening)
Issued at 621 PM CDT TUE MAY 20 2014
VFR conditions expected through the period. NAM suggests MVFR
stratus around sunrise at TOP/FOE , but not seeing evidence of
development to the vicinity or south at this time, will monitor.
Winds initially south become light and variable, eventually
becoming east as surface front settles just along and south of the
terminals.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...65
AVIATION...67
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
218 PM CDT Mon May 19 2014
...Updated long term discussion...
.UPDATE...
ISSUED AT 1141 AM CDT MON MAY 19 2014
Issued a wind advisory for south-central Kansas as winds are at criteria
and conditions will continue through the rest of the day until early
evening via mixing/momentum transfer/tight pg. HWO/EHWO/wind grids all
updated.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 408 AM CDT MON MAY 19 2014
The main question today is how far east the dryline will push today.
The latest NAM12 and near-term hourly RAP model are both very
aggressive in pushing the dryline all the way into central and
south-central KS by late afternoon. This would push the 100-degree
isotherm a bit farther northeast than previously forecast. We now
have 100 degree forecast for Dodge City, Kinsley, Greensburg, Pratt
and 102 at Ashland and Coldwater. Dewpoints will crash into the
teens and even single digits (degF) late this afternoon. Winds west
of the dryline will be in the 20 to 25 knot range, but the lack of a
significant height gradient in the 850-700mb layer will preclude the
need for a wind advisory, despite the very deep mixing. The dryline
will retreat back west at sundown with a marked increase in surface
dewpoints back into the low to mid 50s as far west as Highway 283.
Meanwhile, a weak cold front push into west central Kansas late
tonight with a weak surface low pushing into central Kansas by
daybreak Tuesday.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 212 PM CDT MON MAY 19 2014
The NAM and GFS were in decent agreement with a west to east
surface front extending across southwest Kansas Tuesday night.
North of this front a moist upslope flow will be present roughly
from highway 96 northward, however 700mb temperatures above this
level are forecast to range from 10C to 12C. Given the warm mid
level temperatures the chance for early evening convection of this
boundary appears small between 00z and 06z Wednesday.
On Wednesday A 0-2.5km thta-e ridge axis is forecast to extend
from western Kansas to near Denver. This moist upslope flow
across western Kansas will once again be present under a +10c
700mb temperature, however low level forcing and mid level
instability will improve during the afternoon as the surface
boundary near the Oklahoma border moves north. By mid afternoon
there will be a chance for scattered thunderstorms, especially
north of this surface boundary and near the 0-2.5km thta-e ridge
axis. The chance for convection will then continue and expand in
area coverage during the overnight hours as an upper level
disturbance crosses the Central High Plains. 00z Thursday Cape
values are forecast to be in excess of 2000 j/kg and 0-6km shear
greater than 40knots. Any storm which does develop will be capable
coming severe. With preciptable water values forecast between 1
and 1.5 inches across north central Kansas Wednesday night periods
of heavy rainfall will be possible. In addition baseball size hail
and strong gusty winds can be expected from some of the stronger
thunderstorms. A few tornadoes can not be ruled out near the
surface boundary that is current forecast to be located in west
central and northwest Kansas late Wednesday and early Wednesday night.
For late week into the weekend period...models remain in good
agreement with a closed low crossing California and becoming
nearly stationary over the desert southwest late week. As this
upper level system becomes nearly stationary over the desert
southwest late week, a series of upper level disturbance are
forecast to eject northward across New Mexico into Central High
Plains. Across western Kansas late week and early this weekend a
surface boundary is forecast to drift north and south but
generally remain somewhere between the Oklahoma border and
northwest Kansas. South of this surface boundary a dryline will
extend of this boundary and these two features will be the focus
for precipitation. Given the uncertainty of the exact location of
each of these surface features along with timing issue between the
models of any disturbance crossing the Central High Plains will
stay close to the latest CRExtendFcst_Init for precipitation
chances from Thursday through Sunday. The better opportunity for
widespread precipitation each day late week and over the weekend
period will be north of this surface boundary where upslope flow
and 950mb to 850mb moisture axis will be located. At this time
based on the latest 12z model runs this area is currently forecast
to be located in/near southwest Kansas late Thursday through
Friday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1200 PM CDT MON MAY 19 2014
VFR conditions expected through TAF PD. Strongest winds will be east
of the terminals. Still, SW winds of 15-25 kt can be expected for KGCK/KDDC/KHYS.
S/SE 10-15 kt winds expected tonight as dryline retreats. Weak fropa in
the morning with winds veering WNW-NNW.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 58 94 60 90 / 0 10 10 10
GCK 56 91 58 88 / 0 10 10 20
EHA 56 94 57 89 / 0 0 10 20
LBL 54 96 58 90 / 0 0 10 10
HYS 59 88 61 88 / 0 10 10 20
P28 66 99 66 96 / 0 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING until 9 PM CDT /8 PM MDT/ this evening FOR
KSZ043>046-061>065-074>080-084>089.
WIND ADVISORY until 8 PM CDT this evening FOR KSZ066-081-089-090.
&&
$$
UPDATE...Sugden
SHORT TERM...Umscheid
LONG TERM...Burgert
AVIATION...Sugden
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1200 PM CDT Mon May 19 2014
...Update to aviation...
.SYNOPSIS...
ISSUED AT 1017 AM CDT MON MAY 19 2014
The 19.12Z 250-hPa map showed a 100 kt westerly jet streak located near
KREV. Downstream, 50 kt of flow prevailed across Kansas. At 500-hPa,
a trough was located across the Pacific Northwest/far NE Pacific. Downstream,
ridging prevailed across the Great Plains and into the Midwest. At the
lower levels (H7/H85), warm air advection continued across KDDC with
the EML fully sampled. Ideal downslope southwesterly winds and a temp
at 18C give the clue of a hot day potential across SW Kansas. At the
surface, a low pressure perturbation was located across SE Colorado
with an associated dryline across western Kansas. Another frontal boundary
was located across western Nebraska.
&&
.UPDATE...
ISSUED AT 1141 AM CDT MON MAY 19 2014
Issued a wind advisory for south-central Kansas as winds are at criteria
and conditions will continue through the rest of the day until early
evening via mixing/momentum transfer/tight pg. HWO/EHWO/wind grids all
updated.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 408 AM CDT MON MAY 19 2014
The main question today is how far east the dryline will push today.
The latest NAM12 and near-term hourly RAP model are both very
aggressive in pushing the dryline all the way into central and
south-central KS by late afternoon. This would push the 100-degree
isotherm a bit farther northeast than previously forecast. We now
have 100 degree forecast for Dodge City, Kinsley, Greensburg, Pratt
and 102 at Ashland and Coldwater. Dewpoints will crash into the
teens and even single digits (degF) late this afternoon. Winds west
of the dryline will be in the 20 to 25 knot range, but the lack of a
significant height gradient in the 850-700mb layer will preclude the
need for a wind advisory, despite the very deep mixing. The dryline
will retreat back west at sundown with a marked increase in surface
dewpoints back into the low to mid 50s as far west as Highway 283.
Meanwhile, a weak cold front push into west central Kansas late
tonight with a weak surface low pushing into central Kansas by
daybreak Tuesday.
.LONG TERM...(Tuesday through Sunday)
ISSUED AT 339 AM CDT MON MAY 19 2014
During the extended period, an upper level low is progged to spin
around the desert southwest Tuesday through Thursday then slowly
shift eastward across the Four Corners Region Friday into Saturday.
This low then moves into the Central High Plains Sunday into Monday.
Meanwhile, an upper level ridge will be positioned across the Plains
Tuesday through Friday shifting eastward into the Mississippi Valley
this weekend. Mid levels of the atmosphere increase in moisture
Tuesday afternoon through Friday becoming nearly saturated by this
weekend as the aforementioned upper level low approaches.
Towards the surface, a weak a stationary boundary will bisect the
CWA Tuesday with a dryline positioned south of this feature across
far western Kansas. Southerly winds will be felt ahead of the
dryline and continue to draw more humid air north in the lower
levels. Westerly winds will be observed across far southwestern
Kansas behind the dryline with northerly winds observed north of the
stationary boundary. Elevated fire weather conditions are likely
west of dryline with mostly clear skies anticipated throughout the
day. A slight increase in clouds will be possible across northern
Kansas Tuesday evening into Tuesday night as a weak disturbance
moves through that area. However, no precipitation is expected at
this time. Partly cloudy skies will be observed elsewhere Tuesday
night. Highs Tuesday are forecasted to range from the upper 80s
north of the stationary boundary to upper 90s across the KS/OK
border. Lows Tuesday night are expected to range from the mid 50s
across west central Kansas to upper 60s across south central Kansas.
The dryline retreats west into eastern Colorado Wednesday with a
surface boundary sliding slightly farther south. A slight chance of
thunderstorms will be possible across far western Kansas and north
of this boundary Wednesday afternoon into Wednesday night, otherwise
expected partly cloudy skies. Winds will generally be from an
easterly direction through the day shifting to the southeast
Wednesday night. Highs Wednesday are expected to range from the mid
to upper 80s north of the boundary to mid 90s across south central
Kansas.
The better opportunity for widespread thunderstorms will be from
Thursday through Sunday, especially along and north of a surface
boundary that is suggested to extend from eastern Colorado into
western Kansas. Confidence of where exactly this boundary will
be found is not high and tweaks to the forecast will be needed over
the next couple of days. Nevertheless, moist upslope flow will be
present north of this boundary with an 850mb theta-e ridge axis.
Highs Thursday will be in the mid to upper 80s with highs in the low
to mid 80s Friday through Sunday. Lows Thursday night through Sunday
night will generally be around 60 degrees.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1200 PM CDT MON MAY 19 2014
VFR conditions expected through TAF PD. Strongest winds will be east
of the terminals. Still, SW winds of 15-25 kt can be expected for KGCK/KDDC/KHYS.
S/SE 10-15 kt winds expected tonight as dryline retreats. Weak fropa in
the morning with winds veering WNW-NNW.
&&
.FIRE WEATHER...
ISSUED AT 408 AM CDT MON MAY 19 2014
Critical fire weather conditions will be widespread across west
central and southwest Kansas as a dryline mixes east. West of the
dryline, dewpoints will fall into upper single digits to mid teens,
and with temperatures rising through the mid to upper 90s, this will
lead to extremely low relative humidity down to as low as 4 to 6
percent for a few hours late this afternoon/early this evening. Wind
speeds will average around 20 knots during the afternoon hours as
well from the west-southwest.
Another critical fire weather day is expected Tuesday, but farther
south most likely into the Texas and Oklahoma Panhandles. For now we
will keep far southwest Kansas out of a Fire Weather Watch as it
appears the frontal boundary will stay far enough south for a long
enough portion of the day Tuesday before it lifts back as a warm
front.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 100 58 94 60 / 0 0 10 10
GCK 98 56 91 58 / 0 0 10 10
EHA 97 56 94 57 / 0 0 0 10
LBL 100 54 96 58 / 0 0 0 10
HYS 98 59 88 61 / 0 0 10 10
P28 99 66 99 66 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING until 9 PM CDT /8 PM MDT/ this evening FOR
KSZ043>046-061>065-074>080-084>089.
WIND ADVISORY until 8 PM CDT this evening FOR KSZ066-081-089-090.
&&
$$
UPDATE...Sugden
SYNOPSIS...Sugden
SHORT TERM...Umscheid
LONG TERM...Hovorka_42
AVIATION...Sugden
FIRE WEATHER...Umscheid
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1145 AM CDT Mon May 19 2014
...Update for winds...
.UPDATE...
ISSUED AT 1141 AM CDT MON MAY 19 2014
Issued a wind advisory for south-central Kansas as winds are at criteria
and conditions will continue through the rest of the day until early
evening via mixing/momentum transfer/tight pg. HWO/EHWO/wind grids all
updated.
&&
.SYNOPSIS...
ISSUED AT 1017 AM CDT MON MAY 19 2014
The 19.12Z 250-hPa map showed a 100 kt westerly jet streak located near
KREV. Downstream, 50 kt of flow prevailed across Kansas. At 500-hPa,
a trough was located across the Pacific Northwest/far NE Pacific. Downstream,
ridging prevailed across the Great Plains and into the Midwest. At the
lower levels (H7/H85), warm air advection continued across KDDC with
the EML fully sampled. Ideal downslope southwesterly winds and a temp
at 18C give the clue of a hot day potential across SW Kansas. At the
surface, a low pressure perturbation was located across SE Colorado
with an associated dryline across western Kansas. Another frontal boundary
was located across western Nebraska.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 408 AM CDT MON MAY 19 2014
The main question today is how far east the dryline will push today.
The latest NAM12 and near-term hourly RAP model are both very
aggressive in pushing the dryline all the way into central and
south-central KS by late afternoon. This would push the 100-degree
isotherm a bit farther northeast than previously forecast. We now
have 100 degree forecast for Dodge City, Kinsley, Greensburg, Pratt
and 102 at Ashland and Coldwater. Dewpoints will crash into the
teens and even single digits (degF) late this afternoon. Winds west
of the dryline will be in the 20 to 25 knot range, but the lack of a
significant height gradient in the 850-700mb layer will preclude the
need for a wind advisory, despite the very deep mixing. The dryline
will retreat back west at sundown with a marked increase in surface
dewpoints back into the low to mid 50s as far west as Highway 283.
Meanwhile, a weak cold front push into west central Kansas late
tonight with a weak surface low pushing into central Kansas by
daybreak Tuesday.
.LONG TERM...(Tuesday through Sunday)
ISSUED AT 339 AM CDT MON MAY 19 2014
During the extended period, an upper level low is progged to spin
around the desert southwest Tuesday through Thursday then slowly
shift eastward across the Four Corners Region Friday into Saturday.
This low then moves into the Central High Plains Sunday into Monday.
Meanwhile, an upper level ridge will be positioned across the Plains
Tuesday through Friday shifting eastward into the Mississippi Valley
this weekend. Mid levels of the atmosphere increase in moisture
Tuesday afternoon through Friday becoming nearly saturated by this
weekend as the aforementioned upper level low approaches.
Towards the surface, a weak a stationary boundary will bisect the
CWA Tuesday with a dryline positioned south of this feature across
far western Kansas. Southerly winds will be felt ahead of the
dryline and continue to draw more humid air north in the lower
levels. Westerly winds will be observed across far southwestern
Kansas behind the dryline with northerly winds observed north of the
stationary boundary. Elevated fire weather conditions are likely
west of dryline with mostly clear skies anticipated throughout the
day. A slight increase in clouds will be possible across northern
Kansas Tuesday evening into Tuesday night as a weak disturbance
moves through that area. However, no precipitation is expected at
this time. Partly cloudy skies will be observed elsewhere Tuesday
night. Highs Tuesday are forecasted to range from the upper 80s
north of the stationary boundary to upper 90s across the KS/OK
border. Lows Tuesday night are expected to range from the mid 50s
across west central Kansas to upper 60s across south central Kansas.
The dryline retreats west into eastern Colorado Wednesday with a
surface boundary sliding slightly farther south. A slight chance of
thunderstorms will be possible across far western Kansas and north
of this boundary Wednesday afternoon into Wednesday night, otherwise
expected partly cloudy skies. Winds will generally be from an
easterly direction through the day shifting to the southeast
Wednesday night. Highs Wednesday are expected to range from the mid
to upper 80s north of the boundary to mid 90s across south central
Kansas.
The better opportunity for widespread thunderstorms will be from
Thursday through Sunday, especially along and north of a surface
boundary that is suggested to extend from eastern Colorado into
western Kansas. Confidence of where exactly this boundary will
be found is not high and tweaks to the forecast will be needed over
the next couple of days. Nevertheless, moist upslope flow will be
present north of this boundary with an 850mb theta-e ridge axis.
Highs Thursday will be in the mid to upper 80s with highs in the low
to mid 80s Friday through Sunday. Lows Thursday night through Sunday
night will generally be around 60 degrees.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 614 AM CDT MON MAY 19 2014
VFR conditions will prevail across the TAF sites with only a few
high clouds this morning. Southeast winds at 15 to 20 knots this
morning will shift to the southwest by late morning with gusts
around 30 knots.
&&
.FIRE WEATHER...
ISSUED AT 408 AM CDT MON MAY 19 2014
Critical fire weather conditions will be widespread across west
central and southwest Kansas as a dryline mixes east. West of the
dryline, dewpoints will fall into upper single digits to mid teens,
and with temperatures rising through the mid to upper 90s, this will
lead to extremely low relative humidity down to as low as 4 to 6
percent for a few hours late this afternoon/early this evening. Wind
speeds will average around 20 knots during the afternoon hours as
well from the west-southwest.
Another critical fire weather day is expected Tuesday, but farther
south most likely into the Texas and Oklahoma Panhandles. For now we
will keep far southwest Kansas out of a Fire Weather Watch as it
appears the frontal boundary will stay far enough south for a long
enough portion of the day Tuesday before it lifts back as a warm
front.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 100 58 94 60 / 0 0 10 10
GCK 98 56 91 58 / 0 0 10 10
EHA 97 56 94 57 / 0 0 0 10
LBL 100 54 96 58 / 0 0 0 10
HYS 98 59 88 61 / 0 0 10 10
P28 99 66 99 66 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING until 9 PM CDT /8 PM MDT/ this evening FOR
KSZ043>046-061>065-074>080-084>089.
WIND ADVISORY until 8 PM CDT this evening FOR KSZ066-081-089-090.
&&
$$
UPDATE...Sugden
SYNOPSIS...Sugden
SHORT TERM...Umscheid
LONG TERM...Hovorka_42
AVIATION...Hovorka_42
FIRE WEATHER...Umscheid
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1017 AM CDT Mon May 19 2014
...Update to synopsis...
.SYNOPSIS...
ISSUED AT 1017 AM CDT MON MAY 19 2014
The 19.12Z 250-hPa map showed a 100 kt westerly jet streak located near
KREV. Downstream, 50 kt of flow prevailed across Kansas. At 500-hPa,
a trough was located across the Pacific Northwest/far NE Pacific. Downstream,
ridging prevailed across the Great Plains and into the Midwest. At the
lower levels (H7/H85), warm air advection continued across KDDC with
the EML fully sampled. Ideal downslope southwesterly winds and a temp
at 18C give the clue of a hot day potential across SW Kansas. At the
surface, a low pressure perturbation was located across SE Colorado
with an associated dryline across western Kansas. Another frontal boundary
was located across western Nebraska.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 408 AM CDT MON MAY 19 2014
The main question today is how far east the dryline will push today.
The latest NAM12 and near-term hourly RAP model are both very
aggressive in pushing the dryline all the way into central and
south-central KS by late afternoon. This would push the 100-degree
isotherm a bit farther northeast than previously forecast. We now
have 100 degree forecast for Dodge City, Kinsley, Greensburg, Pratt
and 102 at Ashland and Coldwater. Dewpoints will crash into the
teens and even single digits (degF) late this afternoon. Winds west
of the dryline will be in the 20 to 25 knot range, but the lack of a
significant height gradient in the 850-700mb layer will preclude the
need for a wind advisory, despite the very deep mixing. The dryline
will retreat back west at sundown with a marked increase in surface
dewpoints back into the low to mid 50s as far west as Highway 283.
Meanwhile, a weak cold front push into west central Kansas late
tonight with a weak surface low pushing into central Kansas by
daybreak Tuesday.
.LONG TERM...(Tuesday through Sunday)
ISSUED AT 339 AM CDT MON MAY 19 2014
During the extended period, an upper level low is progged to spin
around the desert southwest Tuesday through Thursday then slowly
shift eastward across the Four Corners Region Friday into Saturday.
This low then moves into the Central High Plains Sunday into Monday.
Meanwhile, an upper level ridge will be positioned across the Plains
Tuesday through Friday shifting eastward into the Mississippi Valley
this weekend. Mid levels of the atmosphere increase in moisture
Tuesday afternoon through Friday becoming nearly saturated by this
weekend as the aforementioned upper level low approaches.
Towards the surface, a weak a stationary boundary will bisect the
CWA Tuesday with a dryline positioned south of this feature across
far western Kansas. Southerly winds will be felt ahead of the
dryline and continue to draw more humid air north in the lower
levels. Westerly winds will be observed across far southwestern
Kansas behind the dryline with northerly winds observed north of the
stationary boundary. Elevated fire weather conditions are likely
west of dryline with mostly clear skies anticipated throughout the
day. A slight increase in clouds will be possible across northern
Kansas Tuesday evening into Tuesday night as a weak disturbance
moves through that area. However, no precipitation is expected at
this time. Partly cloudy skies will be observed elsewhere Tuesday
night. Highs Tuesday are forecasted to range from the upper 80s
north of the stationary boundary to upper 90s across the KS/OK
border. Lows Tuesday night are expected to range from the mid 50s
across west central Kansas to upper 60s across south central Kansas.
The dryline retreats west into eastern Colorado Wednesday with a
surface boundary sliding slightly farther south. A slight chance of
thunderstorms will be possible across far western Kansas and north
of this boundary Wednesday afternoon into Wednesday night, otherwise
expected partly cloudy skies. Winds will generally be from an
easterly direction through the day shifting to the southeast
Wednesday night. Highs Wednesday are expected to range from the mid
to upper 80s north of the boundary to mid 90s across south central
Kansas.
The better opportunity for widespread thunderstorms will be from
Thursday through Sunday, especially along and north of a surface
boundary that is suggested to extend from eastern Colorado into
western Kansas. Confidence of where exactly this boundary will
be found is not high and tweaks to the forecast will be needed over
the next couple of days. Nevertheless, moist upslope flow will be
present north of this boundary with an 850mb theta-e ridge axis.
Highs Thursday will be in the mid to upper 80s with highs in the low
to mid 80s Friday through Sunday. Lows Thursday night through Sunday
night will generally be around 60 degrees.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 614 AM CDT MON MAY 19 2014
VFR conditions will prevail across the TAF sites with only a few
high clouds this morning. Southeast winds at 15 to 20 knots this
morning will shift to the southwest by late morning with gusts
around 30 knots.
&&
.FIRE WEATHER...
ISSUED AT 408 AM CDT MON MAY 19 2014
Critical fire weather conditions will be widespread across west
central and southwest Kansas as a dryline mixes east. West of the
dryline, dewpoints will fall into upper single digits to mid teens,
and with temperatures rising through the mid to upper 90s, this will
lead to extremely low relative humidity down to as low as 4 to 6
percent for a few hours late this afternoon/early this evening. Wind
speeds will average around 20 knots during the afternoon hours as
well from the west-southwest.
Another critical fire weather day is expected Tuesday, but farther
south most likely into the Texas and Oklahoma Panhandles. For now we
will keep far southwest Kansas out of a Fire Weather Watch as it
appears the frontal boundary will stay far enough south for a long
enough portion of the day Tuesday before it lifts back as a warm
front.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 100 58 94 60 / 0 0 10 10
GCK 98 56 91 58 / 0 0 10 10
EHA 97 56 94 57 / 0 0 0 10
LBL 100 54 96 58 / 0 0 0 10
HYS 98 59 88 61 / 0 0 10 10
P28 99 66 99 66 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING until 9 PM CDT /8 PM MDT/ this evening FOR
KSZ043>046-061>065-074>080-084>089.
&&
$$
SYNOPSIS...Sugden
SHORT TERM...Umscheid
LONG TERM...Hovorka_42
AVIATION...Hovorka_42
FIRE WEATHER...Umscheid
AREA FORECAST DISCUSSION
NWS WICHITA KS
659 AM CDT MON MAY 19 2014
...UPDATED FOR 12Z AVIATION DISCUSSION...
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 307 AM CDT MON MAY 19 2014
EXPECT ANOTHER WINDY AFTERNOON...AS A LEE SURFACE LOW TRYS TO
DEVELOP OVER SW KS...WITH A TIGHTENING GRADIENT AHEAD OF THIS LOW
PRESSURE AREA ACROSS MOST OF CENTRAL KS. THIS WILL LEAD TO WIND
GUSTS TO AROUND 40 MPH FOR AREAS WEST OF INTERSTATE 135. LOOKS LIKE
A BORDER LINE SHOT WHEN IT COMES TO WINDS REACHING WIND ADVISORY. SO
WILL HOLD OFF ON ANY HEADLINES FOR NOW.
SOUTHERLY WINDS WILL ALSO LEAD TO THE WARMUP CONTINUING OVER THE
AREA THIS AFTERNOON...WITH AFTERNOON HIGHS CLIMBING INTO THE LOWER
90S IN CENTRAL KS AND THE 80S ELSEWHERE AS 850H TEMPS CLIMB INTO THE
MIDDLE 20S CELSIUS.
TUE-WED: WARM ADVECTION AND LOW LEVEL MOISTURE ADVECTION LOOKS TO
CONTINUE ON TUE INTO WED AS MID-UPPER FLOW BEGINS TO TRANSITION TO
MORE OF A SW FLOW PATTERN WITH A VERY WARM AIRMASS EXPECTED TO
MOVE INTO SW KS. AS THIS WARM AIR PUSHES NORTH...A FRONTAL
BOUNDARY ASSOCIATED WITH A NORTHERN PLAINS SYSTEM WILL DROP SOUTH
INTO NRN KS AND BECOME STATIONARY. COMPRESSIONAL HEATING SOUTH OF
THE BOUNDARY AND A WELL MIXED AIRMASS ACROSS SOUTH CENTRAL KS WILL
LEAD TO SURFACE TEMPS SOARING INTO THE MIDDLE 90S ON TUE. THE
NAM/WRF EVEN SUGGESTS TEMPS POSSIBLY NEAR 100...BUT CONSENSUS
MODEL BLENDS SUGGEST MIDDLE 90S. WITH THIS BOUNDARY STALLING OVER
NORTHERN KS...LOW LEVEL MOISTURE WILL POOL ALONG THE BOUNDARY WITH
INSTABILITY INCREASING...BUT CONVERGENCE DOESNT LOOK STRONG ENOUGH
TO OVERCOME A WARM ELEVATED MIXED LAYER...WHICH WILL KEEP ANY
CONVECTIVE CHANCES CAPPED FOR TUE AFTERNOON INTO TUE NIGHT.
SURFACE BOUNDARY WILL DROP A LITTLE FURTHER SOUTH...ALONG INTERSTATE
70...ON WED WITH A WARM AIRMASS AGAIN EXPECTED ACROSS SRN KS. THINK
SURFACE TEMPS WILL BE A LITTLE COOLER ON WED...IN THE LOW 90S...AS A
LITTLE MORE CLOUDINESS IS EXPECTED WITH THE BOUNDARY A LITTLE
FURTHER SOUTH THAN ON TUE. TEMPS ALOFT WILL BE SLIGHTLY COOLER ON
LATE WED AFTERNOON/EVENING...ESPECIALLY OVER CEN KS. WITH THE
BOUNDARY IN THE AREA. THINK THIS WILL LEAD TO A CHANCE OF SHOWERS
AND THUNDERSTORMS DEVELOPING OVER CENTRAL KS FOR WED EVENING AS THE
ELEVATED MIXED LAYER ERODES. SO WILL GO WITH A CHANCE POP FOR THIS
POSSIBILITY. STRONG TO SEVERE STORMS LOOK POSSIBLE GIVEN BULK SHEAR
OF 40-50 KTS AND THE GFS SHOWING MLCAPE VALUES OF 2500-3000 J/KG.
COULD ACTUALLY SEE CONVECTION INCREASE OVER CENTRAL KS DURING THE
OVERNIGHT HOURS WED NIGHT...AS LOW LEVEL JET INCREASES...ALONG THE
ELEVATED 850-700H BAROCLINIC ZONE. POSSIBLY FORMING AN EASTWARD
MOVING MESOSCALE CONVECTIVE SYSTEM. HOW FAR SOUTH WILL THIS
OVERNIGHT CONVECTION GET IS THE BIG QUESTION...AS PREVAILING
MOVEMENT WILL BE MAINLY EAST-SOUTHEAST.
KETCHAM
.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 307 AM CDT MON MAY 19 2014
SURFACE BOUNDARY WILL LIFT BACK TO THE NORTH SOME ON THU INTO
FRI...WITH MOST OF THE FORECAST AREA FIRMLY IN THE WARM MOIST
SECTOR. THIS WILL PUSH THE MAIN SYNOPTIC BOUNDARY FURTHER NORTH NEAR
THE KS/NE BORDER FOR THU AFTERNOON/NIGHT. AS THIS BOUNDARY PUSHES
NORTH...COOLER AIR ALOFT WILL ALSO PUSH INTO THE PLAINS...WHICH WILL
LEAD TO AN UNCAPPED ENVIRONMENT FOR THUNDERSTORMS DURING THE
AFTERNOON/EVENING HOURS FOR BOTH THU AND FRI...ESPECIALLY ACROSS
CENTRAL AND SOUTH CENTRAL KS.
THE OFF AND ON SHOWER AND THUNDERSTORM CHANCE LOOKS TO CONTINUE INTO
THE WEEKEND...AS A SLOW MOVING UPPER LEVEL LOW OVER THE SRN ROCKIES
MAKES SLOW PROGRESS TOWARDS THE PLAINS...WITH WEAK IMPULSES ROTATING
NORTH INTO PLAINS. THIS WILL LEAD TO CONVECTION IN THE WEAKLY CAPPED
ENVIRONMENT.
NOT EXPECTING MUCH SEVERE WEATHER WITH THE THU-SUN CONVECTION
CHANCES...AS BULK SHEAR WILL BE RELATIVELY WEAK FOR LATE
SPRING...BUT THE UNSTABLE AIRMASS COULD LEAD TO STRONG STORMS AND A
FEW SEVERE STORMS DURING MAX AFTERNOON HEATING.
THIS CERTAINLY LOOKS LIKE A MORE PROMISING SHOWER/STORM CHANCE FOR
MOST OF THE AREA THAN HAS BEEN WITNESSED THUS FAR THIS SPRING.
KETCHAM
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 658 AM CDT MON MAY 19 2014
WIND AND WIND GUSTS WILL BE THE MAIN FORECAST CONCERNS DURING
THE TAF CYCLE. WINDS ALREADY SUSTAINED AROUND 20 KTS WITH
SPORADIC GUSTS 30 TO 35 KTS. NARRE PROBABILITY OF WIND GUST
SUPPORT WIND GUSTS GREATER THAN 20KTS BUT LESS THAN 40KTS...WHICH
IS IN LINE WITH DETERMINISTIC FORECAST GUIDANCE. AXIS OF STRONGER
LOOKS TO BE ALONG RIDGE OF FLINT HILLS...THUS KICT AND KCNU LIKELY
WILL EXPERIENCE THE STRONGER WINDS. GRADIENT BEGINS TO SLACKEN
AFTER 00 UTC/20...SO TONED WIND AND GUSTS DOWN FOR THIS EVENING.
LOWER CONFIDENCE ON IMPACT OF STRATUS THAT IS APPARENT ON SATELLITE
THIS MORNING...ALONG AN AXIS FROM KFSM THROUGH KTUL AND KBVO TO
KEMP. RUC APPEARS TO HAVE A GOOD HANDLE ON ORIENTATION OF NARROW
BAND OF MVFR CIGS...WITH A GOOD PROBABILITY THAT KCNU MAY EXPERIENCE
A BRIEF PERIOD OF MVFR CIGS AROUND 1500 AGL THIS MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 90 65 96 66 / 10 10 10 10
HUTCHINSON 92 63 95 63 / 10 10 10 10
NEWTON 89 63 94 65 / 10 10 10 10
ELDORADO 87 64 92 66 / 10 10 10 10
WINFIELD-KWLD 88 65 94 68 / 10 0 10 10
RUSSELL 95 58 89 62 / 10 10 10 10
GREAT BEND 96 59 90 62 / 10 10 10 10
SALINA 91 62 92 65 / 10 10 10 10
MCPHERSON 91 61 93 62 / 10 10 10 10
COFFEYVILLE 83 65 88 70 / 10 10 10 10
CHANUTE 82 65 88 69 / 10 10 10 10
IOLA 82 65 88 70 / 10 10 10 10
PARSONS-KPPF 83 66 88 70 / 10 10 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
617 AM CDT Mon May 19 2014
...Updated aviation section...
.SHORT TERM...(Today and tonight)
ISSUED AT 408 AM CDT MON MAY 19 2014
The main question today is how far east the dryline will push today.
The latest NAM12 and near-term hourly RAP model are both very
aggressive in pushing the dryline all the way into central and
south-central KS by late afternoon. This would push the 100-degree
isotherm a bit farther northeast than previously forecast. We now
have 100 degree forecast for Dodge City, Kinsley, Greensburg, Pratt
and 102 at Ashland and Coldwater. Dewpoints will crash into the
teens and even single digits (degF) late this afternoon. Winds west
of the dryline will be in the 20 to 25 knot range, but the lack of a
significant height gradient in the 850-700mb layer will preclude the
need for a wind advisory, despite the very deep mixing. The dryline
will retreat back west at sundown with a marked increase in surface
dewpoints back into the low to mid 50s as far west as Highway 283.
Meanwhile, a weak cold front push into west central Kansas late
tonight with a weak surface low pushing into central Kansas by
daybreak Tuesday.
.LONG TERM...(Tuesday through Sunday)
ISSUED AT 339 AM CDT MON MAY 19 2014
During the extended period, an upper level low is progged to spin
around the desert southwest Tuesday through Thursday then slowly
shift eastward across the Four Corners Region Friday into Saturday.
This low then moves into the Central High Plains Sunday into Monday.
Meanwhile, an upper level ridge will be positioned across the Plains
Tuesday through Friday shifting eastward into the Mississippi Valley
this weekend. Mid levels of the atmosphere increase in moisture
Tuesday afternoon through Friday becoming nearly saturated by this
weekend as the aforementioned upper level low approaches.
Towards the surface, a weak a stationary boundary will bisect the
CWA Tuesday with a dryline positioned south of this feature across
far western Kansas. Southerly winds will be felt ahead of the
dryline and continue to draw more humid air north in the lower
levels. Westerly winds will be observed across far southwestern
Kansas behind the dryline with northerly winds observed north of the
stationary boundary. Elevated fire weather conditions are likely
west of dryline with mostly clear skies anticipated throughout the
day. A slight increase in clouds will be possible across northern
Kansas Tuesday evening into Tuesday night as a weak disturbance
moves through that area. However, no precipitation is expected at
this time. Partly cloudy skies will be observed elsewhere Tuesday
night. Highs Tuesday are forecasted to range from the upper 80s
north of the stationary boundary to upper 90s across the KS/OK
border. Lows Tuesday night are expected to range from the mid 50s
across west central Kansas to upper 60s across south central Kansas.
The dryline retreats west into eastern Colorado Wednesday with a
surface boundary sliding slightly farther south. A slight chance of
thunderstorms will be possible across far western Kansas and north
of this boundary Wednesday afternoon into Wednesday night, otherwise
expected partly cloudy skies. Winds will generally be from an
easterly direction through the day shifting to the southeast
Wednesday night. Highs Wednesday are expected to range from the mid
to upper 80s north of the boundary to mid 90s across south central
Kansas.
The better opportunity for widespread thunderstorms will be from
Thursday through Sunday, especially along and north of a surface
boundary that is suggested to extend from eastern Colorado into
western Kansas. Confidence of where exactly this boundary will
be found is not high and tweaks to the forecast will be needed over
the next couple of days. Nevertheless, moist upslope flow will be
present north of this boundary with an 850mb theta-e ridge axis.
Highs Thursday will be in the mid to upper 80s with highs in the low
to mid 80s Friday through Sunday. Lows Thursday night through Sunday
night will generally be around 60 degrees.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 614 AM CDT MON MAY 19 2014
VFR conditions will prevail across the TAF sites with only a few
high clouds this morning. Southeast winds at 15 to 20 knots this
morning will shift to the southwest by late morning with gusts
around 30 knots.
&&
.FIRE WEATHER...
ISSUED AT 408 AM CDT MON MAY 19 2014
Critical fire weather conditions will be widespread across west
central and southwest Kansas as a dryline mixes east. West of the
dryline, dewpoints will fall into upper single digits to mid teens,
and with temperatures rising through the mid to upper 90s, this will
lead to extremely low relative humidity down to as low as 4 to 6
percent for a few hours late this afternoon/early this evening. Wind
speeds will average around 20 knots during the afternoon hours as
well from the west-southwest.
Another critical fire weather day is expected Tuesday, but farther
south most likely into the Texas and Oklahoma Panhandles. For now we
will keep far southwest Kansas out of a Fire Weather Watch as it
appears the frontal boundary will stay far enough south for a long
enough portion of the day Tuesday before it lifts back as a warm
front.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 100 58 94 60 / 0 0 10 10
GCK 98 56 91 58 / 0 0 10 10
EHA 97 56 94 57 / 0 0 0 10
LBL 100 54 96 58 / 0 0 0 10
HYS 98 59 88 61 / 0 0 10 10
P28 99 66 99 66 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING from Noon CDT /11 AM MDT/ today to 9 PM CDT /8
PM MDT/ this evening FOR KSZ043>046-061>065-074>080-084>089.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Hovorka_42
AVIATION...Hovorka_42
FIRE WEATHER...Umscheid
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
409 AM CDT Mon May 19 2014
...Updated short term and fire weather sections...
.SHORT TERM...(Today and tonight)
ISSUED AT 408 AM CDT MON MAY 19 2014
The main question today is how far east the dryline will push today.
The latest NAM12 and near-term hourly RAP model are both very
aggressive in pushing the dryline all the way into central and
south-central KS by late afternoon. This would push the 100-degree
isotherm a bit farther northeast than previously forecast. We now
have 100 degree forecast for Dodge City, Kinsley, Greensburg, Pratt
and 102 at Ashland and Coldwater. Dewpoints will crash into the
teens and even single digits (degF) late this afternoon. Winds west
of the dryline will be in the 20 to 25 knot range, but the lack of a
significant height gradient in the 850-700mb layer will preclude the
need for a wind advisory, despite the very deep mixing. The dryline
will retreat back west at sundown with a marked increase in surface
dewpoints back into the low to mid 50s as far west as Highway 283.
Meanwhile, a weak cold front push into west central Kansas late
tonight with a weak surface low pushing into central Kansas by
daybreak Tuesday.
.LONG TERM...(Tuesday through Sunday)
ISSUED AT 339 AM CDT MON MAY 19 2014
During the extended period, an upper level low is progged to spin
around the desert southwest Tuesday through Thursday then slowly
shift eastward across the Four Corners Region Friday into Saturday.
This low then moves into the Central High Plains Sunday into Monday.
Meanwhile, an upper level ridge will be positioned across the Plains
Tuesday through Friday shifting eastward into the Mississippi Valley
this weekend. Mid levels of the atmosphere increase in moisture
Tuesday afternoon through Friday becoming nearly saturated by this
weekend as the aforementioned upper level low approaches.
Towards the surface, a weak a stationary boundary will bisect the
CWA Tuesday with a dryline positioned south of this feature across
far western Kansas. Southerly winds will be felt ahead of the
dryline and continue to draw more humid air north in the lower
levels. Westerly winds will be observed across far southwestern
Kansas behind the dryline with northerly winds observed north of the
stationary boundary. Elevated fire weather conditions are likely
west of dryline with mostly clear skies anticipated throughout the
day. A slight increase in clouds will be possible across northern
Kansas Tuesday evening into Tuesday night as a weak disturbance
moves through that area. However, no precipitation is expected at
this time. Partly cloudy skies will be observed elsewhere Tuesday
night. Highs Tuesday are forecasted to range from the upper 80s
north of the stationary boundary to upper 90s across the KS/OK
border. Lows Tuesday night are expected to range from the mid 50s
across west central Kansas to upper 60s across south central Kansas.
The dryline retreats west into eastern Colorado Wednesday with a
surface boundary sliding slightly farther south. A slight chance of
thunderstorms will be possible across far western Kansas and north
of this boundary Wednesday afternoon into Wednesday night, otherwise
expected partly cloudy skies. Winds will generally be from an
easterly direction through the day shifting to the southeast
Wednesday night. Highs Wednesday are expected to range from the mid
to upper 80s north of the boundary to mid 90s across south central
Kansas.
The better opportunity for widespread thunderstorms will be from
Thursday through Sunday, especially along and north of a surface
boundary that is suggested to extend from eastern Colorado into
western Kansas. Confidence of where exactly this boundary will
be found is not high and tweaks to the forecast will be needed over
the next couple of days. Nevertheless, moist upslope flow will be
present north of this boundary with an 850mb theta-e ridge axis.
Highs Thursday will be in the mid to upper 80s with highs in the low
to mid 80s Friday through Sunday. Lows Thursday night through Sunday
night will generally be around 60 degrees.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1232 AM CDT MON MAY 19 2014
Flight category of VFR is forecast through tonight amidst a hot
and dry airmass. Winds will remain out of the south and fairly
strong through mid-morning...then shifting to the southwest or
even west-southwest 20 to 25 knots with higher gusts. After
sunset, winds will decrease quite a bit but remain out of the south.
&&
.FIRE WEATHER...
ISSUED AT 408 AM CDT MON MAY 19 2014
Critical fire weather conditions will be widespread across west
central and southwest Kansas as a dryline mixes east. West of the
dryline, dewpoints will fall into upper single digits to mid teens,
and with temperatures rising through the mid to upper 90s, this will
lead to extremely low relative humidity down to as low as 4 to 6
percent for a few hours late this afternoon/early this evening. Wind
speeds will average around 20 knots during the afternoon hours as
well from the west-southwest.
Another critical fire weather day is expected Tuesday, but farther
south most likely into the Texas and Oklahoma Panhandles. For now we
will keep far southwest Kansas out of a Fire Weather Watch as it
appears the frontal boundary will stay far enough south for a long
enough portion of the day Tuesday before it lifts back as a warm
front.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 100 58 94 60 / 0 0 10 10
GCK 98 56 91 58 / 0 0 10 10
EHA 97 56 94 57 / 0 0 0 10
LBL 100 54 96 58 / 0 0 0 10
HYS 98 59 88 61 / 0 0 10 10
P28 99 66 99 66 / 0 0 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING from Noon CDT /11 AM MDT/ today to 9 PM CDT /8
PM MDT/ this evening FOR KSZ043>046-061>065-074>080-084>089.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Hovorka_42
AVIATION...Umscheid
FIRE WEATHER...Umscheid
AREA FORECAST DISCUSSION
NWS TOPEKA KS
346 AM CDT Mon May 19 2014
.SHORT TERM...(Today and Tonight)
Issued at 345 AM CDT MON MAY 19 2014
Water vapor imagery early this morning showed the broad mid-level
ridge centered over the central U.S. with several embedded
shortwaves along the northern edge of the ridge axis. One of the
stronger shortwaves was noted across northern Nebraska in which
thunderstorms developed through the overnight hours. Another shortwave
was seen moving across western Kansas, which contributed to a stream
of mid-level clouds spreading eastward into central Kansas. The
low-level jet was ramping up overnight across western and central
Kansas with 850mb winds upwards of 65kts. However, this 850mb jet
was advecting drier air into the region as an elevated mixed layer
was still noted in model soundings. With this EML in place, it will
make it difficult to develop any elevated thunderstorms, despite the
presence of some increasing isentropic lift. Model soundings
continue to show the potential for a stratus deck to develop for a
few hours this morning as a shallow saturation layer develops up to
about 900mb-850mb. Could possibly get a few light showers or
sprinkles to develop from this shallow saturation layer, however the
lift in this layer looks to be pretty weak. As more dry air gets
advected into the region through the morning hours, that will
continue to limit the potential for scattered precipitation
development. A few short-range models show the potential for some
isolated precipitation to develop across far northeast Kansas, so
have kept the mention of just slight chance PoPs in through 14z with
dry conditions expected for the remainder of the day through
tonight. Temperatures this morning were much warmer than the last
few nights as the combination of increasing mid-level cloud cover
and increasing southeasterly surface winds gusting upwards of
20-30mph helped keep temperatures in the 60s.
Model soundings show the cloud cover clearing out late this morning
into this afternoon with breezy southerly winds from the tight
pressure gradient in place over the region. Expect gusts upwards of
25-35mph this afternoon, which will result in decent warm air
advection into the region. Models show a nose of warmer air
stretching from southwest Kansas into north central Kansas this
afternoon, with high temperatures today likely ranging from the
low/mid 80s over eastern Kansas to the upper 80s/low 90s across
north central Kansas. While surface winds should diminish some this
evening, still expect gusts upwards of 15-25mph overnight. With the
continuation of this warm air advection into the evening hours,
expect mild conditions tonight with lows once again in the 60s.
.LONG TERM...(Tuesday through Sunday)
Issued at 345 AM CDT MON MAY 19 2014
Tuesday through Wednesday, a short wave trough will move east
along the US/Canada border. A cold front associated with this
trough will stall out across Kansas by Tuesday and appears likely
to remain in the region for several days through the coming
weekend. While there will be a front in the region, and warm temps
along with increasing low level moisture will lend plenty of
instability, it appears that the atmosphere will remain capped to
any convective development through Tuesday and much of Wednesday.
Expect some 90s on Tuesday near and immediately south of the front
with upper 80s elsewhere. Wed morning lows will be in the mid to
upper 60s with upper 80s to around 90 expected again on Wednesday.
By late Wednesday afternoon, we get the first indications that the
cap will weaken with the continued influx of low level moisture
and approach of a weak short wave disturbance. Forecast soundings
suggest moderate to strong instability and 40+ kts of 0-6 km
shear across the forecast area with the surface frontal boundary
located somewhere across the forecast area. Expect isolated to
scattered storms to develop near the front by late afternoon/early
evening. While widespread severe weather does not seem likely, this
setup seems to lend a fair chance for storms to become severe
should they develop, and will need to monitor closely as it`s
plausible that a few well organized supercells could develop.
On Wednesday night, there seems to be a favorable setup for an
organized MCS to develop out of afternoon High Plains convection.
Any MCS would likely track near and just north of the surface
front, likely taking it across some part of the local forecast
area. With instability seemingly still in place and potentially
favorable wind fields aloft, could see an organized damaging wind
threat materialize. Will have to see how the details sort out, but
the potential seems to be there.
Thursday will be another day of thunderstorm chances, with
moderate instability forecast, the surface front remaining
somewhere in Kansas, and deep layer shear slightly weaker but
still possibly supporting storm organization. Wed night storms
will likely play a large role in Thursday`s weather, and thus
confidence in any specific convective outcome is fairly low.
Thursday night through Sunday will remain unsettled with with
gradually increasing deep moisture and continued thunderstorm
chances. Expect instability, as a whole, to decrease slightly into
the weekend while deep layer shear decreases dramatically. So,
while thunderstorms remain in the forecast, the severe weather
potential seems to decrease quite a bit. Should also note that
while there are precip chances every day, do not believe that
every location will see precip every day. The potential is there
at any given time but do not expect long term rain outs.
Temperatures through this period should generally have highs
around 80 with lows in the 60s.
&&
.AVIATION...(For the 06Z TAFs through 06Z Monday Night)
Issued at 1144 PM CDT SUN MAY 18 2014
VFR conditions are expected through the next few hours. Low level
moisture return overnight still appears to try and advance
northward therefore have kept the mention of MVFR cigs. With a
strong low level jet the boundary layer should remain mixed enough
to prevent IFR conditions, but it can not be ruled out. There is
still a slight chance of an isolated shower or thunderstorm around
sunrise as the high res models continue to advertised this
possibility. Latest RAP soundings do show an area of saturation
and uncapped lift above the EML.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Hennecke
LONG TERM...Barjenbruch
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1148 PM CDT Sun May 18 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Monday)
Issued at 259 PM CDT SUN MAY 18 2014
19Z water vapor imagery shows an upper trough from the Hudson bay
down along the mid Atlantic seaboard with a shortwave over the mid MS
river valley. A closed low was spinning off the Pacific northwest
coast causing a low amplitude ridge to propagate east across the
Rockies and into the plains. Surface obs show a trough of low
pressure in the lee of the Rockies deepening with higher dewpoints
across the southern plains poised to move north.
For tonight and Monday, models continue to show a strong warm air
advection pattern setting up as the low level jet increases. While
low level moisture is likely to increase with the southerly winds,
models continue to show a stout elevated mixed layer (EML) advecting
in from the southwest. This dry and warm air (700MB temps around
+12C) is expected to form a capping inversion by Monday and the
latest RAP and NAM solutions have this warm air moving in as soon as
this evening. So am still not that optimistic on precip chances
overnight as the low level jet advects dryer air northeast. The RAP
and HRRR have started to show convection coming off the higher
terrain out west, but it falls apart as it runs into the EML. The
GFS is the only solution with any meaningful QPF and the forecast
soundings do not really support elevated convection as it too
advects in the EML and no real instability above the inversion.
There may be an isolated shower along the leading edge of the EML as
decent isentropic upglide provides some lift, so have continued with
some slight chance POPs for the early morning hours. By late in the
morning, the EML should be over much of the area with no real large
scale forcing to break the cap. Therefore expect Monday to remain
dry for the most part. Think the main sensible weather overnight
will be some low stratus advecting north with the moisture return.
The increasing pressure gradient should keep the boundary layer
mixed overnight so fog development appears to have a low probability
of occurring. The breezy winds and increasing low level moisture
should keep lows in the upper 50s to around 60 tonight. Good warm air
advection and afternoon sunshine should help push highs into the mid
80s to around 90.
.LONG TERM...(Monday Night through Sunday)
Issued at 259 PM CDT SUN MAY 18 2014
Medium and longer range periods looking similar to other recent
model runs. Elevated mixed layer should remain in control and keep
convection in check into the mid week periods despite a modest cold
front sinking south. Location of the low level thermal axis is
somewhat in question, but will likely poke most strongly northeast
into southwestern portions of the area Tuesday and back off the to
the southwest Wednesday with low level flow more backed, with highs
into the 90s along it. As the surface high works its way east toward
the Great Lakes, low level moisture will pool along the boundary and
low level jet pick up in intensity Wednesday night. This presents
the first notable chance for precipitation mainly in northern
Kansas. Northwest flow over the eastern CONUS brings the surface
high southeast and with help of convection, helps bring the old
front farther south into Kansas. The EML should weaken and moisten
as models are fairly consistent with precipitation becoming more
widespread in the southern High Plains and local mid level parcels
being sourced from this area. The boundary`s presence and much more
limited convective inhibition will keep precipitation chances
through much of the late week and into the weekend with temperatures
modifying back toward normal. Boundary could be rather weak to
non-existent by the weekend but models are fairly consistent with
the southwest cut-off low topping the Rockies by this time. The
Wednesday night storms could present the highest severe weather
potential when shear profiles are at least moderate, but weakening
flow should keep anything more than pulse severe storms in check for
the bulk the forecast with areas of heavier rains possible from
slow-moving convection in an atmosphere with above normal
precipitable water.
&&
.AVIATION...(For the 06Z TAFs through 06Z Monday Night)
Issued at 1144 PM CDT SUN MAY 18 2014
VFR conditions are expected through the next few hours. Low level
moisture return overnight still appears to try and advance
northward therefore have kept the mention of MVFR cigs. With a
strong low level jet the boundary layer should remain mixed enough
to prevent IFR conditions, but it can not be ruled out. There is
still a slight chance of an isolated shower or thunderstorm around
sunrise as the high res models continue to advertised this
possibility. Latest RAP soundings do show an area of saturation
and uncapped lift above the EML.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...65
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1248 AM EDT MON MAY 19 2014
.SYNOPSIS...
A STATIONARY FRONT WILL REMAIN JUST EAST OF THE AREA INTO MONDAY
WHILE AN UPPER LOW PRESSURE SYSTEM DRIFTS SLOWLY SE THROUGH EARLY
WEEK. WEAK SURFACE HIGH PRESSURE WILL GRADUALLY BUILD INTO THE
REGION TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1245 AM UPDATE...THE PREVIOUS FORECAST IS PRETTY MUCH ON TRACK.
WIDESPREAD SHOWERS ARE FALLING ACROSS THE FORECAST AREA AS THE
REGION REMAINS UNDER THE INFLUENCE OF A TROUGH BOTH AT THE SURFACE
AND ALOFT. EXPECT THIS TO CONTINUE THROUGH THE EARLY MORNING
HOURS. OTHER THAN SOME MINOR TWEAKS TO POPS, WINDS, AND TEMPS
ACCORDING TO CURRENT TRENDS, NO OTHER CHANGES WERE NEEDED WITH
THIS UPDATE.
PREVIOUS DISCUSSION... THE PRIMARY WEATHER CONCERN IN THE NEAR
TERM CONTINUES TO BE THE BOUNDARY THAT IS GENERALLY QUASI
STATIONARY ALONG THE CANADIAN BORDER. THIS BOUNDARY IS CONTINUING
TO BE INFLUENCED BY THE BLOCKING HIGH OFF TO THE EAST. THE WSR-88D
INDICATES AREA OF SHOWERS FROM PORTIONS OF NE AROOSTOOK TO EASTERN
PORTIONS OF PENOBSCOT TO WASHINGTON COUNTIES. THE HRRR GUIDANCE
HAS HAD A GREAT HANDLE ON THE PRECIP TODAY AND THIS GUIDANCE
INDICATES THAT THE PRECIP WILL CONTINUE TO FILL IN THIS AFTERNOON
AND EVENING. THIS FRONTAL BOUNDARY AND UPPER LEVEL JET ENERGY WILL
CONTINUE TO BE THE PRIMARY LIFTING MECHANISMS. THE BEST CHANCES OF
SHOWERS WILL CONTINUE TO BE ACROSS EASTERN PORTIONS OF THE REGION
IN ASSOCIATION WITH THE BOUNDARY. THIS LOW PRESSURE SYSTEM WILL
CONTINUE TO STAY QUASI-STATIONARY ACROSS REGION INTO MONDAY. THIS
COUPLED WITH WITH THE UPPER LEVEL LOW MOVING SOUTH INTO THE GULF
OF MAINE WILL KEEP THE PATTERN UNSETTLED INTO MONDAY.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
THE UPPER LEVEL LOW WILL START THIS PERIOD OFF THE NEW ENGLAND
COAST WITH AN INVERTED TROUGH REMAINING OVER THE FORECAST AREA. A
VORT MAX ASSOCIATED WITH A LOBE ROTATING AROUND THE UPPER LOW IS
EXPECTED TO CROSS THE AREA MONDAY NIGHT. THIS WILL CAUSE SHOWERS.
THE SHOWERS WILL GRADUALLY WEAKEN AND MOVE SOUTH LATER IN THE
NIGHT AS THE UPPER LOW SHIFTS SOUTHWARD. FOR TUESDAY...THE
INVERTED TROUGH WILL BE GONE AND THE SURFACE FLOW WILL SHIFT FROM
NE TO N DURING THE DAY. THIS MEANS COOL TEMPERATURES UNDER MOSTLY
CLOUDY SKIES AND A FEW LIGHT SHOWERS. TRANSITORY SURFACE AND UPPER
RIDGING BUILDS TUESDAY NIGHT INTO WEDNESDAY. THE RIDGING IS
EXPECTED TO END THE LIGHT SHOWERS TUESDAY NIGHT. HOWEVER...CLOUD
COVER CONTINUES INTO WEDNESDAY AS MOIST LOW LEVELS PERSIST. AS THE
UPPER RIDGE CROSSES MIDDAY WEDNESDAY...DAYTIME HEATING AND A
CYCLONIC FLOW MAY SPUR ANOTHER ROUND OF A FEW LIGHT AFTERNOON
SHOWERS. HIGHS DURING THE PERIOD WILL BE IN THE LOW 60S AND LOWS
WILL BE IN THE UPPER 40S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE UPPER RIDGE WILL PROCEED EASTWARD WEDNESDAY NIGHT AND AN UPPER
LEVEL LOW IS PROGGED TO ARRIVE THURSDAY WITH ANOTHER ROUND OF
SHOWERS. THE GUIDANCE DIVERGES ON THURSDAY ON THE TRACK AND
EVOLUTION OF THIS UPPER LEVEL CUT OFF. WILL LEAN TOWARDS THE ECMWF
HANDLING OF THE SYSTEM WHICH BRINGS CLOUDY AND SHOWERY WEATHER
FROM THURSDAY AFTERNOON INTO SATURDAY. HIGHS WILL CONTINUE IN THE
LOWER 60S AND LOWS IN THE UPPER 40S THROUGH THIS PERIOD.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR WITH AREAS OF MVFR NORTH OF KHUL WILL DETERIORATE
TO SOLID MVFR AND POSSIBLY IFR OVERNIGHT IN LOWER STRATUS AND
PATCHY FOG. IFR AT KBGR AND KBHB WITH SLOW IMPROVEMENT TO
MVFR MON PM.
SHORT TERM: MOIST LOW LEVELS AND RAIN SHOWERS ARE EXPECTED THROUGH
MUCH OF THE PERIOD. THIS WILL RESULT IN DIURNALLY DRIVEN
CONDITIONS VARYING FROM PREVAILING IFR OR MVFR AT NIGHT INTO THE
MORNING. CEILINGS WILL GENERALLY IMPROVE TO VFR IN THE AFTERNOONS IN
LINE WITH CLIMATOLOGY.
&&
.MARINE...
NEAR TERM: NO HEADLINES EXPECTED THROUGH MONDAY. SEAS ARE RUNNING
AROUND 4 FT AT THE EASTERN MAINE SHELF AS OF 9 PM...AND IS MOSTLY
THE RESULT OF RESIDUAL LONG PERIOD SWELL. THE VSBY WILL BE REDUCED
TO 1/2 NM OR LESS AT TIMES TONIGHT AND MONDAY MORNING IN FOG.
SHORT TERM: FOG WILL BE THE PRIMARY FORECAST CHALLENGE THROUGH THE
PERIOD. LIGHT WINDS AND A SOUTHERLY SWELL AROUND 2 TO 3 FEET WILL
OCCUR THROUGH THE PERIOD.
&&
.CLIMATE...
FOR THE 2ND DAY IN A ROW A RECORD WARM LOW TEMPERATURE RECORD WAS
BROKEN AT CARIBOU. THE LOW YESTERDAY OF 55 DEGREES WAS THE WARMEST
LOW TEMP EVER OBSERVED ON MAY 17TH. THE OLD RECORD OF 54F WAS SET
IN 1989.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/JORDAN
SHORT TERM...MCW
LONG TERM...MCW
AVIATION...HASTINGS/JORDAN/MCW
MARINE...HASTINGS/JORDAN/MCW
CLIMATE...CB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
915 PM EDT TUE MAY 20 2014
.UPDATE...
COMPOSITE SURFACE BOUNDARY EXTENDING FROM TORONTO THROUGH CHICAGO
INTO IOWA HAS IGNITED A FAIR AMOUNT OF DISCRETE CONVECTION THIS
EVENING. THE ACTIVITY OVER LOWER MICHIGAN HAS BEEN RESTRICTED TO A
SINGLE CELL RESPONSE CURRENTLY MOVING THROUGH OAKLAND AND MACOMB
COUNTIES. THE RESPONSE HAS BEEN FAR MORE IMPRESSIVE OVER NORTHERN
ILLINOIS ALONG THE PERIPHERY OF MUCH GREATER QUALITY INSTABILITY
/COMPARE KDVN AND KDTX RAOB/. AS THE BOUNDARY CONTINUES TO SETTLE
SOUTH SLOWLY DURING THE LATE EVENING HOURS...UPSTREAM CONVECTION
WILL ADVANCE IN A NARROW CORRIDOR OF MODERATE INSTABILITY AHEAD
OF THE BOUNDARY. STORMS HAVE YET TO GEL INTO AN ORGANIZED COMPLEX
AND WILL REQUIRE A LITTLE MORE SIMMER TIME TO FORM A COMMON COLD
POOL. MOREOVER...LATEST RADAR TRENDS SUGGEST PREFERENTIAL
DEVELOPMENT FAVORING A SOUTHWARD DRIFT. EXPECTING ANY ORGANIZATION
TO FAVOR A MOTION THAT KEEPS THE MOST ROBUST ACTIVITY ACROSS
NORTHERN INDIANA AND NORTHWEST OHIO DURING THE OVERNIGHT HOURS.
REGARDLESS...PLENTY OF INSTABILITY TO SUPPORT SOME SEMBLANCE OF
ELEVATED NOCTURNAL CONVECTION ACROSS METRO DETROIT SOUTH TO THE
BORDER. HOWEVER...GREATEST POTENTIAL FOR SEVERE IS BECOMING
BETTER ESTABLISHED SOUTH OF THE BORDER /SEE LATEST SPC SWOMCD/.
&&
.AVIATION...ISSUED 729 PM EDT TUE MAY 20 2014
//DISCUSSION...
A COUPLE ISOLATED SHOWERS AND THUNDERSTORMS HAVE BEGUN TO SPROUT IN
THE VICINITY OF FLINT. THIS ACTIVITY WILL REMAIN LIMITED IN COVERAGE
AND WILL ONLY AFFECT FLINT AND PONTIAC DURING THE FIRST HOUR OR TWO
OF THE FORECAST. MEANWHILE...THUNDERSTORMS ARE CURRENTLY DEVELOPING
AND EXPANDING IN COVERAGE UPSTREAM ACROSS NORTHERN ILLINOIS AND
EASTERN IOWA. CURRENT INDICATIONS ARE THAT THIS ACTIVITY WILL
CONTINUE DEVELOP AND SPREAD EASTWARD OVER THE COURSE OF THE EVENING
HOURS - ARRIVING OVER SOUTHEAST MICHIGAN AFTER MIDNIGHT. FELT
PRUDENT TO INTRODUCE CHANCES FOR THUNDER ACROSS THE DETROIT REGIONAL
TERMINALS VIA A TEMPO GROUP. ORGANIZATIONAL CHARACTERISTICS OF THE
THUNDERSTORM EVOLUTION ARE STILL UNCERTAIN...SO WILL NOT OFFER TOO
MUCH DETAIL WITH THIS OFFERING. BEHIND TONIGHTS ACTIVITY...
ADDITIONAL SHOWERS AND MODESTLY LOW CEILINGS WILL SPREAD ACROSS THE
REGION AS AN AREA OF LOW PRESSURE WORKS ACROSS LOWER MICHIGAN ON
WEDNESDAY. STILL SOME OPPORTUNITY FOR THUNDERSTORM DEVELOPMENT ON
WEDNESDAY IF ENOUGH ISOLATION BECOMES AVAILABLE.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE FOR THUNDERSTORMS BETWEEN 04-07Z TONIGHT.
* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET AFTER 04Z TONIGHT
THROUGH MUCH OF WEDNESDAY.
&&
.PREV DISCUSSION...ISSUED 345 PM EDT TUE MAY 20 2014
SHORT TERM... THROUGH TONIGHT
SHORT TERM CONCERNS STILL REVOLVE AROUND CONVECTIVE TRENDS AND
POTENTIAL FOR SEVERE WEATHER. FIRST...FOR THE REMAINDER OF THIS
AFTERNOON INTO THE EVENING. FAST ZONAL UPPER LEVEL FLOW IS OVER THE
UPPER MIDWEST BETWEEN A RIDGE OVER THE SOUTHERN PLAINS AND A TROUGH
OVER SOUTHERN MANITOBA/SOUTHWESTERN ONTARIO. 18Z SURFACE ANALYSIS
SHOWED A WARM FRONT ARCING SE INTO MICHIGAN FROM ROUGHLY NORTH OF
MUSKEGEON TO LAPEER AND THEN SOUTH TO AROUND MONROE. THE
NORTH/EASTWARD PROGRESS OF THE FRONT IS BEING HINDERED BY FLOW OFF
THE COOLER LAKES. TEMPS CONTINUE TO WARM INTO THE LOW/MID 70S SOUTH
OF THE FRONT WITH DESPOINTS IN THE LOW 50S TO NEAR 60. SOME CUMULUS
IS DEVELOPING OVER SOUTHWESTERN LOWER IN THE LEE OF LAKE
MICHIGAN...BUT SO FAR IT IS SHALLOW. MIDLEVEL LAPSE RATES ARE FAIRLY
MEAGER BUT SHOULD INCREASE INTO THE EVENING. SOME MODEST SURFACE
BASED INSTABLITY MAY DEVELOP AS WE GET LATER INTO THE AFTERNOON AND
EVENING. DEEP LAYER SHEAR OF 35-50KT IS FAVORABLE FOR ORGANIZED
CONVECTION SHOULD ANYTHING DEVELOP...BUT THE LACK OF CLEAR FORCING
MECHANISMS AND GREATER INSTABILITY WILL KEEP POPS IN THE LOW CHANCE
RANGE THROUGH 00Z.
ANOTHER THREAT IS EXPECTED TO DEVELOP AFTER 04Z...BUT IT
IS FAR FROM CERTAIN. DISCRETE CELLS ARE EXPECTED TO DEVELOP OVER
NORTHERN ILLINOIS LATE THIS AFTERNOON. THESE STORMS MAY EVOLVE INTO
ONE OR MORE FORWARD-PROPAGATING QUICK-MOVING MCS...WHICH COULD BE
LONG-LIVED DUE TO CONTINUED STRONG DEEP-LAYER SHEAR AND APPRECIABLE
INSTABILITY. THIS SCENARIO IS SUPPORTED BY THE 16Z HRRR AND THE 12Z
NMM. THESE COMPLEXES WOULD PREFERENTIALLY MOVE TOWARD THE RESERVOIR
OF GREATER INSTABILITY...WHICH IS BETTER TO OUR SOUTH WHERE THE
GREATER MIDLEVEL LAPSE RATES WILL RESIDE. STILL...THE THREAT IS GOOD
ENOUGH TO INCLUDE A SLIGHT CHANCE OF SEVERE WEATHER FROM M-59 SOUTH
/WITH THE BEST CHANCES NEAR THE OHIO BORDER/ FROM AROUND 04-10Z.
DAMAGING WIND WOULD BE THE MAIN THREAT...WITH LARGE HAIL AND AN
ISOLATED TORNADO SECONDARY. HEAVY RAIN IS ALSO POSSIBLE AS PWATS
INCREASE TO 1.3-1.5 INCHES.
LONG TERM...
LARGE UPPER LEVEL LOW SLOWLY WORKING THROUGH ONTARIO
TOMORROW...DROPPING SOUTHEAST INTO NEW ENGLAND THURSDAY NIGHT INTO
FRIDAY WILL DELIVER A RESPECTABLE SHOT OF COOL AIR TO SOUTHEAST
MICHIGAN THURSDAY INTO FRIDAY...BEFORE TEMPERATURES QUICKLY MODERATE
OVER THE WEEKEND AS AMPLIFIED UPPER LEVEL RIDGE BUILDS INTO THE
GREAT LAKES REGION...LIKELY LEADING TO EVEN WARMER TEMPERATURES (80+
DEGREES) EARLY NEXT WEEK.
AS FAR AS TOMORROW GOES...THE FORECAST WILL BE IMPACTED WITH WHAT
OCCURS OVERNIGHT...AS POTENTIAL DEPARTING MCV MAY CAST
SHADOW/SUBSIDENCE WAKE THROUGH A GOOD PORTION OF THE DAY.
OTHERWISE...DO HAVE SHORTWAVE TROUGH AXIS EXTENDING FROM THE
PREVIOUS MENTIONED UPPER LEVEL LOW OVER ONTARIO...WHICH WILL CAUSE
SURFACE COLD FRONT TO SWING THROUGH DURING THE PEAK DIURNAL CYCLE.
STRONG WESTERLY JET (65 KNOTS AT 500 MB) CORE WILL BRING AN
INCREASED RISK OF DAMAGING WINDS IF THUNDERSTORMS ARE ABLE TO
DEVELOP DURING THE AFTERNOON HOURS. THE PROBLEM IS WE CAN NOT FULLY
COUNT ON A MORNING CAP/LULL...AND STORMS COULD EASILY DEVELOP
EARLIER IN THE DAY. DURING THE AFTERNOON HOURS...THE INCREASING
MIXING DEPTHS WE ACCELERATE THE WESTERLY DRYING OUT
PROCESS...LEADING TO QUESTIONS WITH THE AREAL COVERAGE OF THE
POTENTIAL STORMS DEVELOPING ALONG THE COLD FRONT...AS MAX
INSTABILITY LOOKS TO BE OVER THE NORTHERN OHIO VALLEY. WITH THAT
SAID...IT LOOKS FAIRLY LIKELY SOMETIME DURING THE 12 HOUR
WINDOW...NUMEROUS SHOWERS AND THUNDERSTORMS WILL OCCUR...AND
UNFORTUNATELY WILL CARRY GENERIC HIGH SCATTERED/LOW LIKELY POPS
THROUGH THE DAY...AS TONIGHT`S EVOLUTION WILL BE A ONE OF THE KEYS
FOR TOMORROWS WEATHER.
STRONG NORTHWEST FLOW WEDNESDAY NIGHT INTO THURSDAY...WITH 850 MB
TEMPS FALLING INTO THE MID SINGLE NUMBERS. THE CYCLONIC/COLD
ADVECTION AND STEEP LOW LEVEL LAPSE RATES SHOULD BE SUFFICIENT TO
GENERATE PLENTY OF CLOUDS DURING THE DAYTIME HOURS OF
THURSDAY...LIKELY CAPPING MAXES IN THE UPPER 60S TO AROUND 70
DEGREES. ANOTHER PIECE OF ENERGY ROTATING SOUTH THROUGH THE CENTRAL
GREAT LAKES ON FRIDAY SHOULD MAINTAIN THE COOLER TEMPERATURES AND
CONSIDERABLE CLOUDS DURING THE DAYTIME HOURS...AND EVEN SUFFICIENT
DIURNAL INSTABILITY/CAPES/CLOUD DEPTHS (4-12 KFT) TO POSSIBLY
PRODUCE ISOLATED LIGHT SHOWERS.
12Z EURO IS IN DECENT AGREEMENT WITH THE CANADIAN/GFS IN BUILDING
UPPER LEVEL RIDGE OVER THE CENTRAL GREAT LAKES ON
MONDAY...SUPPORTING HIGHS IN EXCESS OF 80 DEGREE WITH INCREASING
SOUTHWEST FLOW AND 850 MB TEMPS WARMING INTO THE MID TEENS INTO
TUESDAY.
MARINE...
INCREASED SOUTHEAST FLOW OVER OUTER SAGINAW BAY AND THE ADJACENT
NEARSHORE WATERS DUE TO THUNDERSTORMS TRACKING THROUGH THE AREA WILL
DIMINISH AS WARM FRONT WEAKENS TONIGHT. A STRONG COLD FRONT WILL
SWING THROUGH THE CENTRAL GREAT LAKES TOMORROW AFTERNOON...WITH
BRISK NORTHWEST WINDS FOLLOWING FOR WEDNESDAY NIGHT AND THURSDAY.
ANY THUNDERSTORMS WHICH DEVELOP TONIGHT THROUGH TOMORROW MAY BE
STRONG TO SEVERE. COOLER AND MORE STABLE AIRMASS WILL FILTER INTO
THE REGION THURSDAY AND FRIDAY...BUT ISOLATED SHOWERS ARE STILL
POSSIBLE. A LARGE UPPER LEVEL RIDGE BUILDING INTO THE GREAT LAKES
REGION OVER THE WEEKEND WILL LEAD TO WARMUP TEMPERATURES AND LIGHT
WINDS.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......MANN
AVIATION.....MANN
SHORT TERM...DT
LONG TERM....SF
MARINE.......SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
729 PM EDT TUE MAY 20 2014
.AVIATION...
//DISCUSSION...
A COUPLE ISOLATED SHOWERS AND THUNDERSTORMS HAVE BEGUN TO SPROUT IN
THE VICINITY OF FLINT. THIS ACTIVITY WILL REMAIN LIMITED IN COVERAGE
AND WILL ONLY AFFECT FLINT AND PONTIAC DURING THE FIRST HOUR OR TWO
OF THE FORECAST. MEANWHILE...THUNDERSTORMS ARE CURRENTLY DEVELOPING
AND EXPANDING IN COVERAGE UPSTREAM ACROSS NORTHERN ILLINOIS AND
EASTERN IOWA. CURRENT INDICATIONS ARE THAT THIS ACTIVITY WILL
CONTINUE DEVELOP AND SPREAD EASTWARD OVER THE COURSE OF THE EVENING
HOURS - ARRIVING OVER SOUTHEAST MICHIGAN AFTER MIDNIGHT. FELT
PRUDENT TO INTRODUCE CHANCES FOR THUNDER ACROSS THE DETROIT REGIONAL
TERMINALS VIA A TEMPO GROUP. ORGANIZATIONAL CHARACTERISTICS OF THE
THUNDERSTORM EVOLUTION ARE STILL UNCERTAIN...SO WILL NOT OFFER TOO
MUCH DETAIL WITH THIS OFFERING. BEHIND TONIGHTS ACTIVITY...
ADDITIONAL SHOWERS AND MODESTLY LOW CEILINGS WILL SPREAD ACROSS THE
REGION AS AN AREA OF LOW PRESSURE WORKS ACROSS LOWER MICHIGAN ON
WEDNESDAY. STILL SOME OPPORTUNITY FOR THUNDERSTORM DEVELOPMENT ON
WEDNESDAY IF ENOUGH ISOLATION BECOMES AVAILABLE.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE FOR THUNDERSTORMS BETWEEN 04-07Z TONIGHT.
* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET AFTER 04Z TONIGHT
THROUGH MUCH OF WEDNESDAY.
&&
.PREV DISCUSSION...ISSUED 345 PM EDT TUE MAY 20 2014
SHORT TERM... THROUGH TONIGHT
SHORT TERM CONCERNS STILL REVOLVE AROUND CONVECTIVE TRENDS AND
POTENTIAL FOR SEVERE WEATHER. FIRST...FOR THE REMAINDER OF THIS
AFTERNOON INTO THE EVENING. FAST ZONAL UPPER LEVEL FLOW IS OVER THE
UPPER MIDWEST BETWEEN A RIDGE OVER THE SOUTHERN PLAINS AND A TROUGH
OVER SOUTHERN MANITOBA/SOUTHWESTERN ONTARIO. 18Z SURFACE ANALYSIS
SHOWED A WARM FRONT ARCING SE INTO MICHIGAN FROM ROUGHLY NORTH OF
MUSKEGEON TO LAPEER AND THEN SOUTH TO AROUND MONROE. THE
NORTH/EASTWARD PROGRESS OF THE FRONT IS BEING HINDERED BY FLOW OFF
THE COOLER LAKES. TEMPS CONTINUE TO WARM INTO THE LOW/MID 70S SOUTH
OF THE FRONT WITH DESPOINTS IN THE LOW 50S TO NEAR 60. SOME CUMULUS
IS DEVELOPING OVER SOUTHWESTERN LOWER IN THE LEE OF LAKE
MICHIGAN...BUT SO FAR IT IS SHALLOW. MIDLEVEL LAPSE RATES ARE FAIRLY
MEAGER BUT SHOULD INCREASE INTO THE EVENING. SOME MODEST SURFACE
BASED INSTABLITY MAY DEVELOP AS WE GET LATER INTO THE AFTERNOON AND
EVENING. DEEP LAYER SHEAR OF 35-50KT IS FAVORABLE FOR ORGANIZED
CONVECTION SHOULD ANYTHING DEVELOP...BUT THE LACK OF CLEAR FORCING
MECHANISMS AND GREATER INSTABILITY WILL KEEP POPS IN THE LOW CHANCE
RANGE THROUGH 00Z.
ANOTHER THREAT IS EXPECTED TO DEVELOP AFTER 04Z...BUT IT
IS FAR FROM CERTAIN. DISCRETE CELLS ARE EXPECTED TO DEVELOP OVER
NORTHERN ILLINOIS LATE THIS AFTERNOON. THESE STORMS MAY EVOLVE INTO
ONE OR MORE FORWARD-PROPAGATING QUICK-MOVING MCS...WHICH COULD BE
LONG-LIVED DUE TO CONTINUED STRONG DEEP-LAYER SHEAR AND APPRECIABLE
INSTABILITY. THIS SCENARIO IS SUPPORTED BY THE 16Z HRRR AND THE 12Z
NMM. THESE COMPLEXES WOULD PREFERENTIALLY MOVE TOWARD THE RESERVOIR
OF GREATER INSTABILITY...WHICH IS BETTER TO OUR SOUTH WHERE THE
GREATER MIDLEVEL LAPSE RATES WILL RESIDE. STILL...THE THREAT IS GOOD
ENOUGH TO INCLUDE A SLIGHT CHANCE OF SEVERE WEATHER FROM M-59 SOUTH
/WITH THE BEST CHANCES NEAR THE OHIO BORDER/ FROM AROUND 04-10Z.
DAMAGING WIND WOULD BE THE MAIN THREAT...WITH LARGE HAIL AND AN
ISOLATED TORNADO SECONDARY. HEAVY RAIN IS ALSO POSSIBLE AS PWATS
INCREASE TO 1.3-1.5 INCHES.
LONG TERM...
LARGE UPPER LEVEL LOW SLOWLY WORKING THROUGH ONTARIO
TOMORROW...DROPPING SOUTHEAST INTO NEW ENGLAND THURSDAY NIGHT INTO
FRIDAY WILL DELIVER A RESPECTABLE SHOT OF COOL AIR TO SOUTHEAST
MICHIGAN THURSDAY INTO FRIDAY...BEFORE TEMPERATURES QUICKLY MODERATE
OVER THE WEEKEND AS AMPLIFIED UPPER LEVEL RIDGE BUILDS INTO THE
GREAT LAKES REGION...LIKELY LEADING TO EVEN WARMER TEMPERATURES (80+
DEGREES) EARLY NEXT WEEK.
AS FAR AS TOMORROW GOES...THE FORECAST WILL BE IMPACTED WITH WHAT
OCCURS OVERNIGHT...AS POTENTIAL DEPARTING MCV MAY CAST
SHADOW/SUBSIDENCE WAKE THROUGH A GOOD PORTION OF THE DAY.
OTHERWISE...DO HAVE SHORTWAVE TROUGH AXIS EXTENDING FROM THE
PREVIOUS MENTIONED UPPER LEVEL LOW OVER ONTARIO...WHICH WILL CAUSE
SURFACE COLD FRONT TO SWING THROUGH DURING THE PEAK DIURNAL CYCLE.
STRONG WESTERLY JET (65 KNOTS AT 500 MB) CORE WILL BRING AN
INCREASED RISK OF DAMAGING WINDS IF THUNDERSTORMS ARE ABLE TO
DEVELOP DURING THE AFTERNOON HOURS. THE PROBLEM IS WE CAN NOT FULLY
COUNT ON A MORNING CAP/LULL...AND STORMS COULD EASILY DEVELOP
EARLIER IN THE DAY. DURING THE AFTERNOON HOURS...THE INCREASING
MIXING DEPTHS WE ACCELERATE THE WESTERLY DRYING OUT
PROCESS...LEADING TO QUESTIONS WITH THE AREAL COVERAGE OF THE
POTENTIAL STORMS DEVELOPING ALONG THE COLD FRONT...AS MAX
INSTABILITY LOOKS TO BE OVER THE NORTHERN OHIO VALLEY. WITH THAT
SAID...IT LOOKS FAIRLY LIKELY SOMETIME DURING THE 12 HOUR
WINDOW...NUMEROUS SHOWERS AND THUNDERSTORMS WILL OCCUR...AND
UNFORTUNATELY WILL CARRY GENERIC HIGH SCATTERED/LOW LIKELY POPS
THROUGH THE DAY...AS TONIGHT`S EVOLUTION WILL BE A ONE OF THE KEYS
FOR TOMORROWS WEATHER.
STRONG NORTHWEST FLOW WEDNESDAY NIGHT INTO THURSDAY...WITH 850 MB
TEMPS FALLING INTO THE MID SINGLE NUMBERS. THE CYCLONIC/COLD
ADVECTION AND STEEP LOW LEVEL LAPSE RATES SHOULD BE SUFFICIENT TO
GENERATE PLENTY OF CLOUDS DURING THE DAYTIME HOURS OF
THURSDAY...LIKELY CAPPING MAXES IN THE UPPER 60S TO AROUND 70
DEGREES. ANOTHER PIECE OF ENERGY ROTATING SOUTH THROUGH THE CENTRAL
GREAT LAKES ON FRIDAY SHOULD MAINTAIN THE COOLER TEMPERATURES AND
CONSIDERABLE CLOUDS DURING THE DAYTIME HOURS...AND EVEN SUFFICIENT
DIURNAL INSTABILITY/CAPES/CLOUD DEPTHS (4-12 KFT) TO POSSIBLY
PRODUCE ISOLATED LIGHT SHOWERS.
12Z EURO IS IN DECENT AGREEMENT WITH THE CANADIAN/GFS IN BUILDING
UPPER LEVEL RIDGE OVER THE CENTRAL GREAT LAKES ON
MONDAY...SUPPORTING HIGHS IN EXCESS OF 80 DEGREE WITH INCREASING
SOUTHWEST FLOW AND 850 MB TEMPS WARMING INTO THE MID TEENS INTO
TUESDAY.
MARINE...
INCREASED SOUTHEAST FLOW OVER OUTER SAGINAW BAY AND THE ADJACENT
NEARSHORE WATERS DUE TO THUNDERSTORMS TRACKING THROUGH THE AREA WILL
DIMINISH AS WARM FRONT WEAKENS TONIGHT. A STRONG COLD FRONT WILL
SWING THROUGH THE CENTRAL GREAT LAKES TOMORROW AFTERNOON...WITH
BRISK NORTHWEST WINDS FOLLOWING FOR WEDNESDAY NIGHT AND THURSDAY.
ANY THUNDERSTORMS WHICH DEVELOP TONIGHT THROUGH TOMORROW MAY BE
STRONG TO SEVERE. COOLER AND MORE STABLE AIRMASS WILL FILTER INTO
THE REGION THURSDAY AND FRIDAY...BUT ISOLATED SHOWERS ARE STILL
POSSIBLE. A LARGE UPPER LEVEL RIDGE BUILDING INTO THE GREAT LAKES
REGION OVER THE WEEKEND WILL LEAD TO WARMUP TEMPERATURES AND LIGHT
WINDS.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MANN
SHORT TERM...DT
LONG TERM....SF
MARINE.......SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
112 PM EDT MON MAY 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EDT MON MAY 19 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH INTO
THE NW CONUS WITH A DOWNSTREAM RIDGE FROM THE SRN PLAINS TO THE
UPPER MS VALLEY. A VIGOROUS SHORTWAVE TROUGH MOVING THROUGH NORTH
DAKOTA ALONG WITH STRONG MOISTURE ADVECTION AHEAD OF A TROUGH
THROUGH THE WRN DAKOTAS SUPPORTED AREAS OF SHRA/TSRA OVER CNTRL INTO
ERN ND. SRLY WINDS AND MID CLOUDS WERE INCREASING ACROSS MN AND WRN
WI AHEAD OF THE APPROACHING TROUGH.
TODAY...EXPECT SLOWLY INCREASING/THICKENING CLOUDS BUT WITH
STRENGTHENING SRLY FLOW AND WAA...TEMPS SHOULD CLIMB INTO THE UPPER
60S. HOWEVER...LOWER TEMPS WILL PREVAIL DOWNSTREAM FROM LAKE MI.
THE MODELS HAVE TRENDED SLIGHTLY SLOWER WITH THE ARRIVAL OF THE
PCPN. SO RAIN SHOULD MOVE IN MAINLY AFTER 21Z OVER THE WEST THIRD.
ONLY SLIGHT CHANCE POPS WERE INCLUDED TO MQT-ESC BY 23Z.
TONIGHT...THE SHORTWAVE TROUGH MOVING THROUGH NRN MN INTO NRN
ONTARIO WILL BRING AN 850 MB WARM FRONT THROUGH THE NRN GREAT LAKES.
300K-305K ISENTROPIC LIFT AHEAD OF THE FRONT WITH STRONG MOISTURE
INFLOW (PWAT TO 1.25 INCH) ON 40-50 KNOT 850-750 MB WINDS SUPPORT
WIDESPREAD RAIN AND POTENTIAL FOR MODERATE RAINFALL AMOUNTS IN THE
0.75-1.00 INCH RANGE. THE PCPN SHOULD QUICKLY SPREAD FROM THE WEST
INTO CNTRL UPPER MI DURING THE LATE EVENING AND OVER THE EAST
OVERNIGHT. ALTHOUGH THE MODELS ONLY SHOW MUCAPE VALUES INTO THE
200-400 J/KG INTO SW UPPER MI...GIVEN THE STRENGTH OF THE LOW LEVEL
INFLOW AND MOISTURE ADVECTION...TSRA MENTION WAS INCLUDED FOR MOST OF
THE CWA EXCEPT THE EAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 444 AM EDT MON MAY 19 2014
HIGHS IN THE MID 50S TO LOW 70S...AND LOWS IN THE 40S THROUGH MUCH
OF THE PERIOD..
QPF/TS...PW VALUES AROUND 1.2IN OR AROUND 175 PERCENT OF NORMAL WILL
SLIDE ACROSS UPPER MI W TO E THROUGH TUESDAY AFTERNOON. WE ARE STILL
EXPECTING CWA AVG RAINFALL AROUND OR OVER 0.75IN...WITH MOST OF THAT
FALLING JUST PRIOR TO 12Z TUESDAY. OF COURSE HIGHER AND LOWER
AMOUNTS WILL BE POSSIBLE...ESPECIALLY IN A TS ENVIRONMENT WHICH WE
WILL BE IN TUESDAY MORNING OVER THE W HALF AND TUESDAY
AFTERNOON-EVENING OVER ALL OF UPPER MI BEFORE ENDING W TO E
OVERNIGHT. THE MAIN CONCERN WITH BE IF THERE WILL BE ANY MOISTURE
LEFT TO ALLOW FOR TS DEVELOPMENT. THE INITIAL SHORTWAVE WILL BE
PUSHING OVER THE CENTRAL CWA MID DAY TUESDAY...COINCIDING WITH THE S
40-50KTS 850MB LLJ 12Z-18Z OVER CENTRAL AND E UPPER MI.
TEMPS...AT 00Z WEDNESDAY /JUST AHEAD OF THE SFC LOW/ FCST MODELS
CONTINUE TO INDICATE 850MB TEMPS RISING TO 10-13C. OF COURSE WITH
SATURATED SOIL SFC TEMPS WILL STAY A COUPLE DEGREES COOLER. 50S AND
60S STILL LOOK REASONABLE FOR TUESDAY...WITH A FEW POCKETS OF 70F
NEAR OVER THE INTERIOR W HALF.
THE SFC RIDGE STRETCHING FROM HUDSON BAY THROUGH THE DAKOTAS ON
WEDNESDAY WILL SLOWLY EDGE INTO THE UPPER GREAT LAKES AS THE LOW
MOVES JUST E OF UPPER MI AND LAKE SUPERIOR AT 18Z WEDNESDAY AND
ALONG THE S ONTARIO/QUEBEC BORDER WEDNESDAY NIGHT. A COUPLE OF
PIECES OF ENERGY ROTATING THROUGH THE NW FLOW ALOFT ON WEDNESDAY
MORNING-AFTERNOON...AND WEDNESDAY NIGHT AS THE PESKY 500MB LOW
FINALLY EXITS TO E ONTARIO.
DRY HIGH PRESSURE WILL BE THE RULE FROM WEDNESDAY NIGHT THROUGH THE
WEEKEND...AS THE SFC AND ALOFT. THE GFS HAS SOME OF THE DRIEST AIR
THIS PERIOD OVER THE W HALF OF UPPER MI WEDNESDAY AFTERNOON...AND
AGAIN FRIDAY AFTERNOON WITH PW VALUES FALLING TO AROUND 50 PERCENT
OF NORMAL OR 0.35IN. ON THE FIRE FRONT...THE DRY AIR COMBINED WITH
NW WINDS GUSTING NEAR 20KTS WILL BE MITIGATED BY THE PRECIP THAT
SHOULD FALL MONDAY NIGHT INTO TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 111 PM EDT MON MAY 19 2014
VFR CONDITIONS WILL CONTINUE INTO EARLY THIS EVENING WHEN RAIN MOVES
IN AND BRINGS DETERIORATING CONDITIONS TO ALL THE SITES. THE
STRENGTHENING SSW FLOW WILL BRING IN MORE MOISTURE TONIGHT THE
ARRIVAL OF MORE VIGOROUS DYNAMIC FORCING WILL RESULT IN RAIN
OVERSPREADING UPPER MI W-E THIS EVENING. CONDITIONS ARE LIKELY TO
DETERIORATE TO MVFR AND THEN IFR OR EVEN LIFR AS THE RAIN CONTINUES
OVERNIGHT. SOME TSRA MAY ALSO BE POSSIBLE BUT CONFIDENCE WAS NOT
HIGH ENOUGH TO INCLUDE MENTION AT THIS TIME.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 501 AM EDT MON MAY 19 2014
WINDS WILL BE UNDER 20KT THROUGHOUT MOST OF THE FORECAST. LOW
PRESSURE DEVELOPING OVER THE PLAINS EARLY NEXT WEEK WILL MOVE ACROSS
NORTHERN LAKE SUPERIOR BEGINNING LATE TONIGHT THROUGH EARLY
WEDNESDAY...WHICH WILL PRODUCE AN INCREASE IN THE WINDS. WINDS
SPEEDS TO AROUND 20 KNOTS MAY OCCUR FOR A TIME OVER CENTRAL AND
EASTERN LAKE SUPERIOR AHEAD OF THE SURFACE LOW. STABLE CONDITIONS
WITH THE WARM AIR MOVING IN...WILL LIMIT WIND SPEEDS NEAR THE SFC.
&&
.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
737 AM EDT MON MAY 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EDT MON MAY 19 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH INTO
THE NW CONUS WITH A DOWNSTREAM RIDGE FROM THE SRN PLAINS TO THE
UPPER MS VALLEY. A VIGOROUS SHORTWAVE TROUGH MOVING THROUGH NORTH
DAKOTA ALONG WITH STRONG MOISTURE ADVECTION AHEAD OF A TROUGH
THROUGH THE WRN DAKOTAS SUPPORTED AREAS OF SHRA/TSRA OVER CNTRL INTO
ERN ND. SRLY WINDS AND MID CLOUDS WERE INCREASING ACROSS MN AND WRN
WI AHEAD OF THE APPROACHING TROUGH.
TODAY...EXPECT SLOWLY INCREASING/THICKENING CLOUDS BUT WITH
STRENGTHENING SRLY FLOW AND WAA...TEMPS SHOULD CLIMB INTO THE UPPER
60S. HOWEVER...LOWER TEMPS WILL PREVAIL DOWNSTREAM FROM LAKE MI.
THE MODELS HAVE TRENDED SLIGHTLY SLOWER WITH THE ARRIVAL OF THE
PCPN. SO RAIN SHOULD MOVE IN MAINLY AFTER 21Z OVER THE WEST THIRD.
ONLY SLIGHT CHANCE POPS WERE INCLUDED TO MQT-ESC BY 23Z.
TONIGHT...THE SHORTWAVE TROUGH MOVING THROUGH NRN MN INTO NRN
ONTARIO WILL BRING AN 850 MB WARM FRONT THROUGH THE NRN GREAT LAKES.
300K-305K ISENTROPIC LIFT AHEAD OF THE FRONT WITH STRONG MOISTURE
INFLOW (PWAT TO 1.25 INCH) ON 40-50 KNOT 850-750 MB WINDS SUPPORT
WIDESPREAD RAIN AND POTENTIAL FOR MODERATE RAINFALL AMOUNTS IN THE
0.75-1.00 INCH RANGE. THE PCPN SHOULD QUICKLY SPREAD FROM THE WEST
INTO CNTRL UPPER MI DURING THE LATE EVENING AND OVER THE EAST
OVERNIGHT. ALTHOUGH THE MODELS ONLY SHOW MUCAPE VALUES INTO THE
200-400 J/KG INTO SW UPPER MI...GIVEN THE STRENGTH OF THE LOW LEVEL
INFLOW AND MOISTURE ADVECTION...TSRA MENTION WAS INCLUDED FOR MOST OF
THE CWA EXCEPT THE EAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 444 AM EDT MON MAY 19 2014
HIGHS IN THE MID 50S TO LOW 70S...AND LOWS IN THE 40S THROUGH MUCH
OF THE PERIOD..
QPF/TS...PW VALUES AROUND 1.2IN OR AROUND 175 PERCENT OF NORMAL WILL
SLIDE ACROSS UPPER MI W TO E THROUGH TUESDAY AFTERNOON. WE ARE STILL
EXPECTING CWA AVG RAINFALL AROUND OR OVER 0.75IN...WITH MOST OF THAT
FALLING JUST PRIOR TO 12Z TUESDAY. OF COURSE HIGHER AND LOWER
AMOUNTS WILL BE POSSIBLE...ESPECIALLY IN A TS ENVIRONMENT WHICH WE
WILL BE IN TUESDAY MORNING OVER THE W HALF AND TUESDAY
AFTERNOON-EVENING OVER ALL OF UPPER MI BEFORE ENDING W TO E
OVERNIGHT. THE MAIN CONCERN WITH BE IF THERE WILL BE ANY MOISTURE
LEFT TO ALLOW FOR TS DEVELOPMENT. THE INITIAL SHORTWAVE WILL BE
PUSHING OVER THE CENTRAL CWA MID DAY TUESDAY...COINCIDING WITH THE S
40-50KTS 850MB LLJ 12Z-18Z OVER CENTRAL AND E UPPER MI.
TEMPS...AT 00Z WEDNESDAY /JUST AHEAD OF THE SFC LOW/ FCST MODELS
CONTINUE TO INDICATE 850MB TEMPS RISING TO 10-13C. OF COURSE WITH
SATURATED SOIL SFC TEMPS WILL STAY A COUPLE DEGREES COOLER. 50S AND
60S STILL LOOK REASONABLE FOR TUESDAY...WITH A FEW POCKETS OF 70F
NEAR OVER THE INTERIOR W HALF.
THE SFC RIDGE STRETCHING FROM HUDSON BAY THROUGH THE DAKOTAS ON
WEDNESDAY WILL SLOWLY EDGE INTO THE UPPER GREAT LAKES AS THE LOW
MOVES JUST E OF UPPER MI AND LAKE SUPERIOR AT 18Z WEDNESDAY AND
ALONG THE S ONTARIO/QUEBEC BORDER WEDNESDAY NIGHT. A COUPLE OF
PIECES OF ENERGY ROTATING THROUGH THE NW FLOW ALOFT ON WEDNESDAY
MORNING-AFTERNOON...AND WEDNESDAY NIGHT AS THE PESKY 500MB LOW
FINALLY EXITS TO E ONTARIO.
DRY HIGH PRESSURE WILL BE THE RULE FROM WEDNESDAY NIGHT THROUGH THE
WEEKEND...AS THE SFC AND ALOFT. THE GFS HAS SOME OF THE DRIEST AIR
THIS PERIOD OVER THE W HALF OF UPPER MI WEDNESDAY AFTERNOON...AND
AGAIN FRIDAY AFTERNOON WITH PW VALUES FALLING TO AROUND 50 PERCENT
OF NORMAL OR 0.35IN. ON THE FIRE FRONT...THE DRY AIR COMBINED WITH
NW WINDS GUSTING NEAR 20KTS WILL BE MITIGATED BY THE PRECIP THAT
SHOULD FALL MONDAY NIGHT INTO TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 736 AM EDT MON MAY 19 2014
EXPECT VFR CONDITIONS TO PREVAIL THROUGH TODAY WITH AN INITIALLY DRY
S WIND ASSOCIATED WITH HIGH PRES MOVING AWAY FROM THE REGION.
AS THE PRES GRADIENT TIGHTENS OVER THE NRN GREAT LAKES BETWEEN THE
DEPARTING HIGH AND A LOW MOVING EAST OUT OF THE NRN PLAINS IN THE
PRESENCE OF DAYTIME HEATING/MIXING...THE WINDS WILL BECOME GUSTY.
THE STRENGTHENING SSW FLOW WILL BRING IN MORE MOISTURE TONIGHT
THE ARRIVAL OF MORE VIGOROUS DYNAMIC FORCING WILL RESULT IN RAIN
OVERSPREADING UPPER MI W-E LATE THIS AFTERNOON AND THIS EVENING.
CONDITIONS ARE LIKELY TO DETERIORATE TO MVFR AND THEN IFR AS THE
RAIN CONTINUES OVERNIGHT. SOME TSRA MAY ALSO BE POSSIBLE BUT
CONFIDENCE WAS NOT HIGH ENOUGH TO INCLUDE MENTION AT THIS TIME.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 501 AM EDT MON MAY 19 2014
WINDS WILL BE UNDER 20KT THROUGHOUT MOST OF THE FORECAST. LOW
PRESSURE DEVELOPING OVER THE PLAINS EARLY NEXT WEEK WILL MOVE ACROSS
NORTHERN LAKE SUPERIOR BEGINNING LATE TONIGHT THROUGH EARLY
WEDNESDAY...WHICH WILL PRODUCE AN INCREASE IN THE WINDS. WINDS
SPEEDS TO AROUND 20 KNOTS MAY OCCUR FOR A TIME OVER CENTRAL AND
EASTERN LAKE SUPERIOR AHEAD OF THE SURFACE LOW. STABLE CONDITIONS
WITH THE WARM AIR MOVING IN...WILL LIMIT WIND SPEEDS NEAR THE SFC.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
507 AM EDT MON MAY 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EDT MON MAY 19 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH INTO
THE NW CONUS WITH A DOWNSTREAM RIDGE FROM THE SRN PLAINS TO THE
UPPER MS VALLEY. A VIGOROUS SHORTWAVE TROUGH MOVING THROUGH NORTH
DAKOTA ALONG WITH STRONG MOISTURE ADVECTION AHEAD OF A TROUGH
THROUGH THE WRN DAKOTAS SUPPORTED AREAS OF SHRA/TSRA OVER CNTRL INTO
ERN ND. SRLY WINDS AND MID CLOUDS WERE INCREASING ACROSS MN AND WRN
WI AHEAD OF THE APPROACHING TROUGH.
TODAY...EXPECT SLOWLY INCREASING/THICKENING CLOUDS BUT WITH
STRENGTHENING SRLY FLOW AND WAA...TEMPS SHOULD CLIMB INTO THE UPPER
60S. HOWEVER...LOWER TEMPS WILL PREVAIL DOWNSTREAM FROM LAKE MI.
THE MODELS HAVE TRENDED SLIGHTLY SLOWER WITH THE ARRIVAL OF THE
PCPN. SO RAIN SHOULD MOVE IN MAINLY AFTER 21Z OVER THE WEST THIRD.
ONLY SLIGHT CHANCE POPS WERE INCLUDED TO MQT-ESC BY 23Z.
TONIGHT...THE SHORTWAVE TROUGH MOVING THROUGH NRN MN INTO NRN
ONTARIO WILL BRING AN 850 MB WARM FRONT THROUGH THE NRN GREAT LAKES.
300K-305K ISENTROPIC LIFT AHEAD OF THE FRONT WITH STRONG MOISTURE
INFLOW (PWAT TO 1.25 INCH) ON 40-50 KNOT 850-750 MB WINDS SUPPORT
WIDESPREAD RAIN AND POTENTIAL FOR MODERATE RAINFALL AMOUNTS IN THE
0.75-1.00 INCH RANGE. THE PCPN SHOULD QUICKLY SPREAD FROM THE WEST
INTO CNTRL UPPER MI DURING THE LATE EVENING AND OVER THE EAST
OVERNIGHT. ALTHOUGH THE MODELS ONLY SHOW MUCAPE VALUES INTO THE
200-400 J/KG INTO SW UPPER MI...GIVEN THE STRENGTH OF THE LOW LEVEL
INFLOW AND MOISTURE ADVECTION...TSRA MENTION WAS INCLUDED FOR MOST OF
THE CWA EXCEPT THE EAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 444 AM EDT MON MAY 19 2014
HIGHS IN THE MID 50S TO LOW 70S...AND LOWS IN THE 40S THROUGH MUCH
OF THE PERIOD..
QPF/TS...PW VALUES AROUND 1.2IN OR AROUND 175 PERCENT OF NORMAL WILL
SLIDE ACROSS UPPER MI W TO E THROUGH TUESDAY AFTERNOON. WE ARE STILL
EXPECTING CWA AVG RAINFALL AROUND OR OVER 0.75IN...WITH MOST OF THAT
FALLING JUST PRIOR TO 12Z TUESDAY. OF COURSE HIGHER AND LOWER
AMOUNTS WILL BE POSSIBLE...ESPECIALLY IN A TS ENVIRONMENT WHICH WE
WILL BE IN TUESDAY MORNING OVER THE W HALF AND TUESDAY
AFTERNOON-EVENING OVER ALL OF UPPER MI BEFORE ENDING W TO E
OVERNIGHT. THE MAIN CONCERN WITH BE IF THERE WILL BE ANY MOISTURE
LEFT TO ALLOW FOR TS DEVELOPMENT. THE INITIAL SHORTWAVE WILL BE
PUSHING OVER THE CENTRAL CWA MID DAY TUESDAY...COINCIDING WITH THE S
40-50KTS 850MB LLJ 12Z-18Z OVER CENTRAL AND E UPPER MI.
TEMPS...AT 00Z WEDNESDAY /JUST AHEAD OF THE SFC LOW/ FCST MODELS
CONTINUE TO INDICATE 850MB TEMPS RISING TO 10-13C. OF COURSE WITH
SATURATED SOIL SFC TEMPS WILL STAY A COUPLE DEGREES COOLER. 50S AND
60S STILL LOOK REASONABLE FOR TUESDAY...WITH A FEW POCKETS OF 70F
NEAR OVER THE INTERIOR W HALF.
THE SFC RIDGE STRETCHING FROM HUDSON BAY THROUGH THE DAKOTAS ON
WEDNESDAY WILL SLOWLY EDGE INTO THE UPPER GREAT LAKES AS THE LOW
MOVES JUST E OF UPPER MI AND LAKE SUPERIOR AT 18Z WEDNESDAY AND
ALONG THE S ONTARIO/QUEBEC BORDER WEDNESDAY NIGHT. A COUPLE OF
PIECES OF ENERGY ROTATING THROUGH THE NW FLOW ALOFT ON WEDNESDAY
MORNING-AFTERNOON...AND WEDNESDAY NIGHT AS THE PESKY 500MB LOW
FINALLY EXITS TO E ONTARIO.
DRY HIGH PRESSURE WILL BE THE RULE FROM WEDNESDAY NIGHT THROUGH THE
WEEKEND...AS THE SFC AND ALOFT. THE GFS HAS SOME OF THE DRIEST AIR
THIS PERIOD OVER THE W HALF OF UPPER MI WEDNESDAY AFTERNOON...AND
AGAIN FRIDAY AFTERNOON WITH PW VALUES FALLING TO AROUND 50 PERCENT
OF NORMAL OR 0.35IN. ON THE FIRE FRONT...THE DRY AIR COMBINED WITH
NW WINDS GUSTING NEAR 20KTS WILL BE MITIGATED BY THE PRECIP THAT
SHOULD FALL MONDAY NIGHT INTO TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 129 AM EDT MON MAY 19 2014
EXPECT VFR CONDITIONS TO PREVAIL THRU TODAY WITH AN INITIALLY DRY S
WIND ASSOCIATED WITH HI PRES MOVING INTO THE MID ATLANTIC STATES. AS
THE PRES GRADIENT TIGHTENS OVER THE UPR LKS BTWN THIS DEPARTING HI
AND A LO PRES MOVING E OUT OF THE NRN PLAINS IN THE PRESENCE OF
DAYTIME HEATING/MIXING...THE WINDS WL TURN GUSTY. THE STRENGTHENING
SSW FLOW WL TAP MORE MSTR TNGT...AND THE ARRIVAL OF MORE VIGOROUS
DYNAMIC FORCING WL RESULT IN RA OVERSPREADING UPR MI W-E LATE THIS
AFTN/EVNG. CONDITIONS ARE LIKELY TO DETERIORATE TO MVFR AND THEN IFR
BEFORE THE END OF THE TAP PERIOD AT IWD...WHERE THE PCPN WL ARRIVE
EARLIEST. MORE TENACIOUS DRY LLVL AIR WL DELAY THE DETERIORATION AT
CMX/SAW...BUT EVEN THERE MVFR CONDITIONS AND LLWS ARE LIKELY BY THE
END OF THE TAF PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 501 AM EDT MON MAY 19 2014
WINDS WILL BE UNDER 20KT THROUGHOUT MOST OF THE FORECAST. LOW
PRESSURE DEVELOPING OVER THE PLAINS EARLY NEXT WEEK WILL MOVE ACROSS
NORTHERN LAKE SUPERIOR BEGINNING LATE TONIGHT THROUGH EARLY
WEDNESDAY...WHICH WILL PRODUCE AN INCREASE IN THE WINDS. WINDS
SPEEDS TO AROUND 20 KNOTS MAY OCCUR FOR A TIME OVER CENTRAL AND
EASTERN LAKE SUPERIOR AHEAD OF THE SURFACE LOW. STABLE CONDITIONS
WITH THE WARM AIR MOVING IN...WILL LIMIT WIND SPEEDS NEAR THE SFC.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
116 PM CDT MON MAY 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 515 AM CDT MON MAY 19 2014
THE SURFACE LOW IN SOUTH DAKOTA CONTINUES TO LIFT TO THE NORTHEAST
THIS MORNING AND SLOWLY FILL WITH TIME. WIDESPREAD WARM ADVECTION IS
OCCURRING ACROSS THE NORTHERN PLAINS AND PORTIONS OF THE UPPER
MISSISSIPPI RIVER VALLEY. THE THUNDERSTORMS ARE NEARLY CO-LOCATED
WITH THE 850-300MB THICKNESS RIDGE...WHICH REACHES THE WESTERN
FORECAST AREA BETWEEN 12Z AND 14Z. WE THINK THE MORE WIDESPREAD
SHOWERS AND STORMS WILL BE CLOSER TO THE NOSE OF THE 925-850MB
MOISTURE TRANSPORT. THIS WOULD SUGGEST A BULK OF THE ACTIVITY TODAY
WILL COME ACROSS CENTRAL MN AND NORTHWEST WI. OUR QPF IS PROBABLY
OVERDONE ON ACROSS THE SOUTHERN FORECAST AREA...ESPECIALLY IF YOU
BUY INTO SOME OF THE NEW 09Z MESO-MODEL GUIDANCE FROM THE HRRR AND
HOPWRF /HOPWRF.INFO/. THEY HAVE VERY LITTLE ACTIVITY IN SOUTH
CENTRAL MN. EVENTUALLY THE THICKNESS RIDGE SAGS SOUTHEAST AND WHAT
APPEARS TO BE A WEAK SURFACE TROUGH SETS UP OVER FAR SOUTHERN AND
NORTHERN IA LATE THIS AFTERNOON AND EARLY EVENING. SO...AFTER THIS
FIRST BATCH OF PRECIP MOVES THROUGH THERE SHOULD BE A LAG IN THE
PRECIP OVER MUCH OF MN IN THE LATE MORNING AND AFTERNOON...BEFORE
POSSIBLE REDEVELOPMENT THIS EVENING. THIS SECOND ROUND IS MUCH MORE
CONDITIONAL AND WE`RE NOT TOTALLY SURE WHERE THE THUNDERSTORMS WILL
SET UP. IT COULD REMAIN MOSTLY IN IOWA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 515 AM CDT MON MAY 19 2014
THE WEATHER IN THE EXTENDED HINGES HEAVILY ON A CUTOFF LOW OVER THE
DESERT SOUTHWEST...THE SHORTWAVES THAT WILL EJECT OUT FROM THAT
LOW...AND THE NORTHERN STREAM TO ACROSS SOUTHERN CANADA. IF THINGS
PAN OUT AS CURRENTLY FORECAST...THE UPCOMING PERIOD WILL BE DRY FOR
THE UPPER MIDWEST AS THE RAIN REMAINS FOCUSED TO THE SOUTH AND
NORTH.
AT THE START OF THE PERIOD AN UPPER LEVEL LOW ACROSS NORTH DAKOTA
WILL ROTATE EASTWARD ALONG THE INTERNATIONAL BORDER AND DRIVE A COLD
FRONT THROUGH THE REGION...BUT MIXING SHOULD BRING TEMPS NEAR 80F ON
TUESDAY. A REINFORCEMENT OF COLD AIR WILL MOVE THOUGH THE REGION
TUESDAY NIGHT...SO TEMPERATURES WILL BE MUCH COOLER ON WEDNESDAY.
MEANWHILE...AN UPPER LEVEL LOW WILL BECOME CUTOFF ACROSS THE DESERT
SOUTHWEST. A FEW SHORTWAVES WILL SPIN OFF OF THIS VORTICITY
MAX...AND BE THE FOCUS FOR SHOWERS AND THUNDERSTORMS. CONFIDENCE IN
THE TIMING AND PLACEMENT OF THESE SHORTWAVES IS VERY LOW...BUT
EVENTUALLY THIS WAVE WILL KICK OUT AND MOVE TOWARDS THE CENTRAL
CONUS. THE 20POPS IN THE EXTENDED ARE A REFLECTION OF THIS
POTENTIAL...AND UNCERTAINTY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1250 PM CDT MON MAY 19 2014
BAND OF SHRA/ISO TSRA SLOWLY WORKING EAST WITH LLJ THIS AFTERNOON.
HRRR HAS NOT BEEN BAD WITH TIMING THIS PRECIP...THOUGH WITH
ACTIVITY STILL BUILDING BACK SW INTO THE LLJ...MAY NEED TO DELAY
END OF PRECIP A BIT MORE FOR MSP/RNH/EAU. HAVE CONTINUED TO TREND
CIG FORECAST AWAY FROM THE GFSLAMP AND MORE TOWARD THE
RAP/HRRR...THOUGH THIS MAY HAVE RESULTED IN TAFS THAT WERE A
LITTLE TOO AGGRESSIVE WITH IMPROVEMENTS TO VFR. BASED ON THE HRRR
AND OTHER HI-RES MODELS..ANOTHER ROUND OF STORMS ALONG THE COLD
FRONT IS BEGINNING TO LOOK UNLIKELY...SO STARTED TO DOWNPLAY THAT
IN TAFS. FOR WINDS...PRES GRADIENT OUT IN WEST CENTRAL MN IS QUITE
TIGHT...SO DO EXPECT GUSTS UP NEAR 35 KTS AT AXN THROUGH 21Z
BEFORE SFC LOW NEAR ABR STARTS TO FILL IN.
KMSP...BASED ON BACK BUILDING OF RETURNS TO THE SW...WE MAY HAVE
TO PUSH ENDING OF PRECIP BACK A COUPLE OF HOURS UNTIL THE LLJ
CLEARS US OFF TO THE EAST. LESS CONFIDENCE WITH CIG FORECAST.
GFSLAMP CONTINUES TO BE WAY TOO MOIST WITH THE LOW LEVELS...SO
IT/S SO CONTINUED TO SHY AWAY FROM GOING THAT ROUTE. FOLLOWED
MORE THE TREND OF THE HRRR...BUT THIS MAY BE A BIT QUICK IN GOING
BACK TO VFR. HEIGHTS TO THE SW OF THE PRECIP HAVE BEEN BETWEEN 015
AND 025...SO EXPECT CIGS TO PRIMARILY REMAIN ABOVE 015. LOOKS
UNLIKELY FOR ANY ADDITIONAL PRECIP WITH THE COLD FROPA...WITH FEW
WEATHER ISSUES EXPECTED TUESDAY.
/OUTLOOK FOR KMSP/
WED...VFR. WINDS NW 10-15 KTS.
THU...VFR. WINDS NE 5-10 KTS.
FRI...VFR. WINDS SE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF/JRB
LONG TERM...JRB
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
654 AM CDT MON MAY 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 515 AM CDT MON MAY 19 2014
THE SURFACE LOW IN SOUTH DAKOTA CONTINUES TO LIFT TO THE NORTHEAST
THIS MORNING AND SLOWLY FILL WITH TIME. WIDESPREAD WARM ADVECTION IS
OCCURRING ACROSS THE NORTHERN PLAINS AND PORTIONS OF THE UPPER
MISSISSIPPI RIVER VALLEY. THE THUNDERSTORMS ARE NEARLY CO-LOCATED
WITH THE 850-300MB THICKNESS RIDGE...WHICH REACHES THE WESTERN
FORECAST AREA BETWEEN 12Z AND 14Z. WE THINK THE MORE WIDESPREAD
SHOWERS AND STORMS WILL BE CLOSER TO THE NOSE OF THE 925-850MB
MOISTURE TRANSPORT. THIS WOULD SUGGEST A BULK OF THE ACTIVITY TODAY
WILL COME ACROSS CENTRAL MN AND NORTHWEST WI. OUR QPF IS PROBABLY
OVERDONE ON ACROSS THE SOUTHERN FORECAST AREA...ESPECIALLY IF YOU
BUY INTO SOME OF THE NEW 09Z MESO-MODEL GUIDANCE FROM THE HRRR AND
HOPWRF /HOPWRF.INFO/. THEY HAVE VERY LITTLE ACTIVITY IN SOUTH
CENTRAL MN. EVENTUALLY THE THICKNESS RIDGE SAGS SOUTHEAST AND WHAT
APPEARS TO BE A WEAK SURFACE TROUGH SETS UP OVER FAR SOUTHERN AND
NORTHERN IA LATE THIS AFTERNOON AND EARLY EVENING. SO...AFTER THIS
FIRST BATCH OF PRECIP MOVES THROUGH THERE SHOULD BE A LAG IN THE
PRECIP OVER MUCH OF MN IN THE LATE MORNING AND AFTERNOON...BEFORE
POSSIBLE REDEVELOPMENT THIS EVENING. THIS SECOND ROUND IS MUCH MORE
CONDITIONAL AND WE`RE NOT TOTALLY SURE WHERE THE THUNDERSTORMS WILL
SET UP. IT COULD REMAIN MOSTLY IN IOWA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 515 AM CDT MON MAY 19 2014
THE WEATHER IN THE EXTENDED HINGES HEAVILY ON A CUTOFF LOW OVER THE
DESERT SOUTHWEST...THE SHORTWAVES THAT WILL EJECT OUT FROM THAT
LOW...AND THE NORTHERN STREAM TO ACROSS SOUTHERN CANADA. IF THINGS
PAN OUT AS CURRENTLY FORECAST...THE UPCOMING PERIOD WILL BE DRY FOR
THE UPPER MIDWEST AS THE RAIN REMAINS FOCUSED TO THE SOUTH AND
NORTH.
AT THE START OF THE PERIOD AN UPPER LEVEL LOW ACROSS NORTH DAKOTA
WILL ROTATE EASTWARD ALONG THE INTERNATIONAL BORDER AND DRIVE A COLD
FRONT THROUGH THE REGION...BUT MIXING SHOULD BRING TEMPS NEAR 80F ON
TUESDAY. A REINFORCEMENT OF COLD AIR WILL MOVE THOUGH THE REGION
TUESDAY NIGHT...SO TEMPERATURES WILL BE MUCH COOLER ON WEDNESDAY.
MEANWHILE...AN UPPER LEVEL LOW WILL BECOME CUTOFF ACROSS THE DESERT
SOUTHWEST. A FEW SHORTWAVES WILL SPIN OFF OF THIS VORTICITY
MAX...AND BE THE FOCUS FOR SHOWERS AND THUNDERSTORMS. CONFIDENCE IN
THE TIMING AND PLACEMENT OF THESE SHORTWAVES IS VERY LOW...BUT
EVENTUALLY THIS WAVE WILL KICK OUT AND MOVE TOWARDS THE CENTRAL
CONUS. THE 20POPS IN THE EXTENDED ARE A REFLECTION OF THIS
POTENTIAL...AND UNCERTAINTY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 644 AM CDT MON MAY 19 2014
AS EXPECTED...SHOWERS AND THUNDERSTORMS ARE MOVING INTO MN AND
WILL CONTINUE TO THE EAST WITH TIME. OUTSIDE OF KAXN...WHICH WILL
HAVE STORMS EARLY THIS MORNING...LOOK FOR AN ARRIVAL TIME FOR
THUNDER LATE THIS MORNING OR NEAR THE NOON HOUR FOR MOST OTHER
TAF SITES. WE THINK THE STORMS WILL BECOME LESS INTENSE AS THEY
HEAD EAST. WE ARE ALSO MONITORING THE POTENTIAL FOR LOW CEILINGS
DEVELOPING...MVFR/IFR...BEHIND THE RAIN TODAY.
KMSP...
THERE IS STILL A THREAT FOR THUNDER TODAY WITH THOSE STORMS MOVING
FROM WEST TO EAST IN WESTERN MN...HOWEVER...WE DO THINK THE STORMS
WILL WEAKEN BEFORE REACHING THE AIRPORT. THEY ARE PRODUCING
0.50"-1.5" HAIL THIS MORNING. WE HAVE MODERATE TO HIGH CONFIDENCE
IN A COUPLE PERIODS OF RAIN LATE THIS MORNING AND AGAIN NEAR THE
EVENING RUSH. THERE IS ALSO THE POTENTIAL FOR MVFR CEILINGS. A LOT
OF THE MODELS WE USE ARE SHOWING CEILINGS BELOW 1500FT BY THE
EVENING...BUT THESE CAN OFTEN BE A BIT TOO AGGRESSIVE WITH
BRINGING IN POOR CONDITIONS.
/OUTLOOK FOR KMSP/
TUE...MVFR CIGS IN THE MORNING. BECOMING VFR. WINDS W 10G20KT.
WED...VFR. WINDS NW 10KT.
THU...VFR. WINDS NE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF/JRB
LONG TERM...JRB
AVIATION...CLF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
517 AM CDT MON MAY 19 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 515 AM CDT MON MAY 19 2014
THE SURFACE LOW IN SOUTH DAKOTA CONTINUES TO LIFT TO THE NORTHEAST
THIS MORNING AND SLOWLY FILL WITH TIME. WIDESPREAD WARM ADVECTION IS
OCCURRING ACROSS THE NORTHERN PLAINS AND PORTIONS OF THE UPPER
MISSISSIPPI RIVER VALLEY. THE THUNDERSTORMS ARE NEARLY CO-LOCATED
WITH THE 850-300MB THICKNESS RIDGE...WHICH REACHES THE WESTERN
FORECAST AREA BETWEEN 12Z AND 14Z. WE THINK THE MORE WIDESPREAD
SHOWERS AND STORMS WILL BE CLOSER TO THE NOSE OF THE 925-850MB
MOISTURE TRANSPORT. THIS WOULD SUGGEST A BULK OF THE ACTIVITY TODAY
WILL COME ACROSS CENTRAL MN AND NORTHWEST WI. OUR QPF IS PROBABLY
OVERDONE ON ACROSS THE SOUTHERN FORECAST AREA...ESPECIALLY IF YOU
BUY INTO SOME OF THE NEW 09Z MESO-MODEL GUIDANCE FROM THE HRRR AND
HOPWRF /HOPWRF.INFO/. THEY HAVE VERY LITTLE ACTIVITY IN SOUTH
CENTRAL MN. EVENTUALLY THE THICKNESS RIDGE SAGS SOUTHEAST AND WHAT
APPEARS TO BE A WEAK SURFACE TROUGH SETS UP OVER FAR SOUTHERN AND
NORTHERN IA LATE THIS AFTERNOON AND EARLY EVENING. SO...AFTER THIS
FIRST BATCH OF PRECIP MOVES THROUGH THERE SHOULD BE A LAG IN THE
PRECIP OVER MUCH OF MN IN THE LATE MORNING AND AFTERNOON...BEFORE
POSSIBLE REDEVELOPMENT THIS EVENING. THIS SECOND ROUND IS MUCH MORE
CONDITIONAL AND WE`RE NOT TOTALLY SURE WHERE THE THUNDERSTORMS WILL
SET UP. IT COULD REMAIN MOSTLY IN IOWA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 515 AM CDT MON MAY 19 2014
THE WEATHER IN THE EXTENDED HINGES HEAVILY ON A CUTOFF LOW OVER THE
DESERT SOUTHWEST...THE SHORTWAVES THAT WILL EJECT OUT FROM THAT
LOW...AND THE NORTHERN STREAM TO ACROSS SOUTHERN CANADA. IF THINGS
PAN OUT AS CURRENTLY FORECAST...THE UPCOMING PERIOD WILL BE DRY FOR
THE UPPER MIDWEST AS THE RAIN REMAINS FOCUSED TO THE SOUTH AND
NORTH.
AT THE START OF THE PERIOD AN UPPER LEVEL LOW ACROSS NORTH DAKOTA
WILL ROTATE EASTWARD ALONG THE INTERNATIONAL BORDER AND DRIVE A COLD
FRONT THROUGH THE REGION...BUT MIXING SHOULD BRING TEMPS NEAR 80F ON
TUESDAY. A REINFORCEMENT OF COLD AIR WILL MOVE THOUGH THE REGION
TUESDAY NIGHT...SO TEMPERATURES WILL BE MUCH COOLER ON WEDNESDAY.
MEANWHILE...AN UPPER LEVEL LOW WILL BECOME CUTOFF ACROSS THE DESERT
SOUTHWEST. A FEW SHORTWAVES WILL SPIN OFF OF THIS VORTICITY
MAX...AND BE THE FOCUS FOR SHOWERS AND THUNDERSTORMS. CONFIDENCE IN
THE TIMING AND PLACEMENT OF THESE SHORTWAVES IS VERY LOW...BUT
EVENTUALLY THIS WAVE WILL KICK OUT AND MOVE TOWARDS THE CENTRAL
CONUS. THE 20POPS IN THE EXTENDED ARE A REFLECTION OF THIS
POTENTIAL...AND UNCERTAINTY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1053 PM CDT SUN MAY 18 2014
SHORT TERM SOLUTIONS LATE THIS EVENING ARE NOT AS UNIFIED ON
PROGRESSING A BAND OF SHOWERS/THUNDERSTORMS ACROSS THE TAF SITES
EARLY MONDAY MORNING AS EARLIER RUNS INDICATED. HENCE...CONFIDENCE
IS NOT AS HIGH AS BEFORE. TRIED TO MAINTAIN SOME CONTINUITY IN THE
TAFS WITH SHRA/TSRA INTO WESTERN MN IN THE 10Z-14Z TIME FRAME AND
ACROSS EASTERN MN FROM 14Z-18Z. STILL THINK THE ACTIVITY WEAKENS
SOME WHILE MOVING ACROSS WEST CENTRAL WI EARLY IN THE AFTERNOON.
ANOTHER TREND THAT IS DEVELOPING IS THE SLIPPAGE OF CEILINGS BELOW
010. EVEN THE PESSIMISTIC NAM IS NOW SEVERAL HOURS LATER IN THE
DAY BEFORE BRINGING CEILINGS DOWN. MADE ADJUSTMENTS TO THE
CEILINGS TRENDS AS WELL. BREEZY SE WINDS REMAIN IN THE FORECAST
FOR MONDAY WITH THE STRONGEST SUSTAINED WINDS NEAR 20 KNOTS FOR
KAXN AND KRWF ALONG WITH GUSTS INTO THE UPPER 20 KNOT RANGE.
KMSP...A FEW SPRINKLES DEVELOPING OVERNIGHT WITH MORE WIDESPREAD
SHOWERS INDICATED FOR THE MID TO LATE MORNING HOURS ALONG WITH THE
THREAT OF THUNDERSTORMS. MVFR CEILINGS INDICATED FOR THE AFTERNOON
WITH IFR DELAYED UNTIL EVENING. SE WINDS 16G24KTS FOR MONDAY
AFTERNOON.
/OUTLOOK FOR KMSP/
TUE...MVFR CIGS SHRA/TSRA ENDING IN THE MORNING. BECOMING VFR.
WINDS W 10G20KT.
WED...VFR. WINDS NW 10KT.
THU...VFR. WINDS NE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF/JRB
LONG TERM...JRB
AVIATION...RAH
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
808 PM CDT TUE MAY 20 2014
.UPDATE...EXPECT DRY WEATHER AGAIN TONIGHT AS HIGH PRESSURE REMAINS
IN CONTROL ACROSS THE REGION. LOWS TONIGHT WILL MAINLY BE IN THE
UPPER 50S TO AROUND 60. AS FOR THE CURRENT FORECAST...ONLY CHANGE WAS
TO ADD AREAS OF FOG FOR LATER TONIGHT INTO TOMORROW AM FOR PORTIONS
OF CENTRAL AND SOUTH MS BASED ON THE LATEST HRRR AND SREF. /27/
&&
.AVIATION...THIS IS SOMEWHAT OF A PERSISTENCE FORECAST...AND A
REPEAT OF LIFR/IFR CATEGORY STRATUS/FOG IS LIKELY IN THE 08-14Z TIME
FRAME EARLY WEDNESDAY OVER SE PORTIONS OF THE AREA...MAINLY
AFFECTING HBG/PIB UP TO JAN/HKS/MEI/NMM. OTHERWISE...VFR CONDITIONS
WILL PREVAIL. /EC/
&&
.PREV DISCUSSION... /ISSUED 216 PM CDT TUE MAY 20 2014/
SHORT TERM...
VERY QUIET WEATHER EXPECTED NEXT FEW DAYS AS DEEP LAYER RIDGING HOLDS
FIRM ACROSS THE REGION. ONLY MINIMAL INCREASE IN MOISTURE EXPECTED AS
LOW LEVEL ANTICYCLONE DOMINATES GULF REGION...KEEPING GULF MOISTURE
AT BAY AND PRECIPITABLE WATER VALUES AOB 1 INCH. SOME LOW CLOUDS AND
LIGHT FOG CAN BE EXPECTED DURING LATE NIGHT AND EARLY MORNING
HOURS...MAINLY SOUTH OF INTERSTATE 20. OTHERWISE EXPECT PLENTY OF
CLEAR SKIES WITH LARGE DIURNAL RANGES IN TEMPS. MODELS ARE OVERALL IN
VERY GOOD AGREEMENT AND SEE NO COMPELLING REASON TO DEVIATE FROM
GUIDANCE. /AEG/
&&
LONG TERM...THURSDAY THROUGH NEXT TUESDAY...HIGH PRESSURE AT THE
SURFACE AND STOUT RIDGING ALOFT WILL REMAIN IN CONTROL OF THE WEATHER
ACROSS THE REGION THROUGH MOST OF THE LONG TERM PORTION OF THE
FORECAST. MOISTURE WILL GRADUALLY INCREASE THROUGH THE PERIOD
RESULTING IN HIGHS EACH AFTERNOON GENERALLY TOPPING OUT AROUND 90.
MEANWHILE...LOWS EACH NIGHT WILL REMAIN MILD AS THEY ONLY FALL INTO
THE 60S.
RAIN CHANCES WILL BE RATHER SCARCE THROUGH THE PERIOD DUE TO THE
AFOREMENTIONED PERSISTENT UPPER LEVEL RIDGING. HOWEVER EARLY NEXT
WEEK...A WEAKENING IN THE RIDGE COULD ALLOW AN UPPER LEVEL
DISTURBANCE TO AT LEAST BRUSH THE REGION...BRINGING SMALL RAIN
CHANCES BACK INTO THE FORECAST. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 60 88 62 90 / 0 0 0 0
MERIDIAN 57 89 59 90 / 0 0 0 0
VICKSBURG 61 88 61 90 / 0 0 0 0
HATTIESBURG 61 89 61 91 / 0 0 0 0
NATCHEZ 61 88 61 88 / 0 0 0 0
GREENVILLE 63 89 65 90 / 0 0 0 2
GREENWOOD 61 88 62 89 / 0 0 0 2
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1118 PM CDT Sun May 18 2014
.UPDATE:
Issued at 918 PM CDT Sun May 18 2014
No forecast update needed as going trends still looking quite good,
with latest RUC and HRRR data still hinting at a slight chance of elevated
convection late tonight and early Monday morning over northwest
sections of the CWA. Believe current activity along I-35 N of Des
Moines will try to develop SE and may clip our extreme northern
counties, but think the "main" threat for our area will be
developing late tonight near the IA-MO border.
Truett
&&
.SHORT TERM: (Through Late Tonight)
Issued at 330 PM CDT Sun May 18 2014
1025mb high pressure off to our east continues to dominate our
region with light E-SE winds and a dry atmospheric column.
It is expected to be clear for most areas thru much of tonight, and
with light SE winds, will allow for another night of below average
temps, but warmer than previous nights, with mins from the mid 40s
in IL to the low 50s in MO. Clouds will move in from central MO
just after midnight towards the MS river by sunrise, and with a
substantial increase in moisture and aided by the eastern extremity
of a low level jet, there remains a window of opportunity for SHRA
or TSRA development in parts of northeast MO for late tonight.
Extended the slight chance PoP into late tonight from where it
previously was for just Monday morning.
TES/Carney
.LONG TERM: (Monday through Next Sunday)
Issued at 330 PM CDT Sun May 18 2014
(Monday - Wednesday)
Warm temperatures make a return with passage of a warm front on
Monday and peaking by Wednesday, just before a cold front drops into
the area.
Models build an upper level ridge into the lower-mid MS valley
during this period. The brief window of opportunity for SHRA and
TSRA development from late tonight will carryover until late Monday
morning over the northeast quarter of MO and west-central IL until a
strong capping inversion moves in and effectively shuts off any pcpn
potential. This capping inversion is then expected to be
sufficiently strong enough, in what is also a warm sector setup,
largely absent of any boundaries or triggers, until a cold front can
begin to make an approach to northern MO and central IL later on
Tuesday night, or more likely, Wednesday. Just have sub-climo
slight chances going for the northern CWA Tuesday night, and then up
them to chance category for roughly the same area on Wednesday.
Temps are still expected to surge to well above average values by
mid-week for most areas, with maxes of 75 to 80 on Monday and
mid-upper 80s for Tuesday and Wednesday.
The better rain chances will be associated with the slowly dropping
cold front beginning late Tuesday night over northern MO/central IL
and continuing thru Friday as this front eventually makes it to
southern MO/IL by Thursday night-Friday.
(Wednesday Night - Next Sunday)
Plenty of rain chances this period with temps moderating closer back
to normal for late May.
The cold front will slowly make its way south thru our region, not
expected to fully exit southeast MO and southern IL until early
Friday. A greatly weakened capping inversion, upper-level
disturbances rolling on by, and the presence of the surface front
will enable a persistent chance for SHRA/TSRA at least thru Friday
for most areas. Into next weekend, it looks more hazy, but it
appears the front is still going to try to buckle northward and/or
dissipate, and may prolong the rain chances, especially for
central-southeast MO. Nevertheless, the PoPs forecast are at or
below climatology, which is 30% for this time of year.
Max temps expected to slip back into the 70s for late week and into
next weekend, depending on how long it takes for the front to either
move back north or dissipate. The powerful storm system still looks
trapped in the southwestern USA thru next weekend.
TES
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1039 PM CDT Sun May 18 2014
E-sely surface wind will continue late tonight with surface ridge
centered over the Ohio Valley region. The surface wind will become
relatively strong and gusty late Monday morning and afternoon due
to a tightening surface pressure gradient as low pressure develops
over the central Plains. Mid-high level cloudiness will spread
eastward into the area late tonight as low-mid level warm air
advection increases over the region. It appears that any isolated,
elevated convection will remain north or west of the taf sites
late tonight and Monday morning. Patchy MVFR clouds were
already spreading northward into southwest MO, and cannot rule
out that some of this cloudiness could advect into COU and the
St Louis metro area early Monday morning. Scattered diurnal
cumulus clouds will likely develop late Monday morning and
afternoon as low level moisture increases over the area with a
subtle warm front lifting north-northeastward through our region.
Most of the low-mid level cloudiness should shift northeast of COU
and the St Louis metro area by late Monday evening.
Specifics for KSTL: E-sely surface wind will continue late tonight,
then increase to around 15 kts gusting to 25 kts late Monday
morning and afternoon. Mid-high level clouds will spread eastward
into STL towards morning. Scattered diurnal cumulus clouds is
expected for late Monday morning and afternoon. Much of the low-
mid level clouds will dissipate or advect northeast of STL by late
Monday evening with only some high level clouds remaining. The
surface wind should weaken some Monday night and lose much of the
gustiness.
GKS
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
856 AM MDT MON MAY 19 2014
.UPDATE...
SPLIT FLOW OVER THE NW CONUS TODAY...WITH INITIAL TROF NOW
LOCATED TO OUR NORTH AND SECONDARY LOW DROPPING ALONG THE OR/CA
COAST. WE ARE BETWEEN THESE SYSTEMS TODAY BUT WITH ENOUGH MOISTURE
AND INSTABILITY TO PRODUCE SHOWERS AND SOME TSTMS. TFX RAOB SHOWS
CONVECTIVE TEMPS IN THE UPPER 50S...AND THIS IS CONSISTENT WITH
LATEST RAP SOUNDINGS IN OUR AREA...SO WOULD EXPECT CONVECTION TO
GET GOING FAIRLY EARLY TODAY AND PROBABLY NO LATER THAN NOON. IN
FACT...THERE ARE ALREADY SOME LIGHT SHOWERS IN NE MUSSELSHELL
COUNTY IN RESPONSE TO WEAK JET FORCING. WETBULB ZERO HEIGHTS
AROUND 5.5KFT SUGGEST SMALL HAIL WITH ANY STRONGER CELLS...BUT
OTHERWISE THE ACTIVITY WILL BE MUCH WEAKER THAN WE SAW YESTERDAY.
NO SEVERE WX IS EXPECTED TODAY.
HAVE MADE A FEW TWEAKS TO REMOVE MORNING FOG AND LOWER 15-18Z POPS
SLIGHTLY. WINDS WILL BE WESTERLY AND A LITTLE GUSTY TODAY WITH
MIXING. HIGH TEMPS WILL BE MOSTLY IN THE 60S.
JKL
&&
.SHORT TERM...VALID FOR TDY AND TUE...
AS A RESULT OF THE RAIN THAT FELL ACROSS MUCH OF THE REGION
SUNDAY AFTERNOON/EVENING AND SOME LIGHT WINDS THIS MORNING...WE
WILL SEE PATCHY FOG ACROSS THE AREA. LOOK FOR FOG TO BURN OFF BY
MID MORNING. ATTENTION THEN SHIFTS TO THE POTENTIAL FOR MORE
SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON AND
EVENING...PARTICULARLY ACROSS THE WESTERN HALF OF THE REGION AS A
SERIES OF SHORTWAVES AND JET MAXES IN SOUTHWEST FLOW ALOFT WORK
WITH AN UNSTABLE AIRMASS AND...OF COURSE...TERRAIN. SHEAR VALUES
ARE NOT CONDUCIVE FOR SEVERE WEATHER...BUT WITH CAPE VALUES
PROGGED TO BE UPWARDS OF 400 OR 500 J/KG ACROSS PORTIONS OF THE
AREA AND LI VALUES OF -1C ACROSS MUCH OF THE REGION...CERTAINLY WE
COULD SEE AT LEAST SOME WEAK...SHORT-LIVED THUNDERSTORMS THIS
AFTERNOON/EVENING. THE CHANCE OF THUNDERSTORMS IS LOWER ACROSS THE
EAST DUE TO SOME CONVERGENT FLOW ALOFT. OUTSIDE OF
THUNDERSTORMS...MIXING THROUGH THE DAY SHOULD RESULT IN WEST TO
NORTHWEST WINDS GENERALLY IN THE 15 TO 25 MPH RANGE TODAY AS HIGHS
REACH THE 60S TO NEAR 70.
WEAK RIDGING LOOKS TO BUILD INTO THE REGION TONIGHT...SO THE
POTENTIAL FOR SHOWERS AND THUNDERSTORMS DIMINISHES SIGNIFICANTLY
THROUGH EARLY TUESDAY. PARTIAL CLEARING WILL ALLOW TEMPS TO BOTTOM
OUT IN THE MID 30S ACROSS THE WEST AND THE 40S ACROSS THE EAST
TONIGHT. MORE SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE TUESDAY
AFTERNOON AND EVENING...ESPECIALLY ACROSS THE SOUTHWESTERN HALF OF
THE REGION AS SHORTWAVE ENERGY EJECTS NORTHEASTWARD OUT OF AN
UPPER LEVEL LOW IN THE GREAT BASIN...AND FLOW OVER THE BILLINGS
CWA REMAINS SOUTHWESTERLY. INSTABILITY WILL ALSO BE FAVORABLE FOR
SOME CONVECTION AS 850-500 MB LAPSE RATES ACROSS THE SOUTHWESTERN
HALF OF THE REGION ARE EXPECTED TO BE BETWEEN 7C AND 8C PER KM.
HIGHS TUESDAY WILL BE SIMILAR TO TODAY. STC
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
EXTENDED RANGE PROGGS IN GOOD AGREEMENT ON GENERAL PATTERN. CUT
OFF UPPER LOW OVER THE DESERT SW WILL LAY UNDER BROAD ANTI-
CYCLONIC FLOW FOR MUCH OF THE COUNTRY. 850MB TEMPS SUGGEST WE WILL
SEE SOME OF THE WARMEST TEMPERATURES OF THE SEASON THUS FAR BY
THURSDAY AND FRIDAY...WHILE STRONG SE SURFACE FLOW LEADS TO SOME
POTENTIALLY STRONG THUNDERSTORMS OVER THE EASTERN BORDER COUNTY
ZONES FROM MILES CITY TO BROADUS AND EASTWARD. THE RIDGE BREAKS
DOWN AROUND SATURDAY EVENING AS A TROUGH IN THE NORTHERN STREAM
MOVES THROUGH THE NORTHERN ROCKIES. THIS SHOULD LEAD TO A MORE
WIDESPREAD COVERAGE OF THUNDERSTORMS FOR THE WEEKEND.
THE WARMER TEMPERATURES AFTER MIDWEEK WILL RESULT IN AN INCREASE
IN HIGH ELEVATION SNOWMELT...SO AREA RIVERS AND STREAMS WILL
LIKELY SEE STEADY RISES LATE THIS WEEK. BT
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH MIDDAY BEFORE SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOP...AND LOCAL MVFR IS EXPECTED
THIS AFTERNOON AND EARLY EVENING. STRONGER CELLS COULD ALSO
PRODUCE SMALL HAIL AND WIND GUSTS TO 30 KTS. MOUNTAINS WILL BE
OCCASIONALLY OBSCURED. SHOWER AND TSTM ACTIVITY WILL DIMINISH THIS
EVENING WITH VFR PREVAILING TONIGHT. JKL
&&
.PRELIMINARY POINT TEMP/POPS...
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 067 044/067 046/071 048/080 051/083 052/076 050/073
4/T 23/T 22/T 11/B 12/T 23/T 33/T
LVM 062 037/065 039/070 043/081 046/080 045/073 043/073
5/T 35/T 32/T 12/T 22/T 24/T 43/T
HDN 069 042/069 046/074 046/081 050/084 052/079 050/075
4/T 23/T 32/T 22/T 22/T 23/T 33/T
MLS 069 044/069 047/074 049/080 051/085 055/079 052/075
2/T 22/W 12/T 22/T 22/T 23/T 33/T
4BQ 069 042/069 046/073 047/081 049/083 052/079 049/073
2/T 22/T 42/T 32/T 22/T 23/T 32/T
BHK 068 043/066 045/071 047/077 050/081 053/078 053/074
2/T 12/W 12/T 32/T 22/T 23/T 33/T
SHR 065 039/065 044/070 043/078 044/079 049/075 047/071
4/T 33/T 43/T 22/T 22/T 23/T 32/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1016 PM MDT SUN MAY 18 2014
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY...
THE SEVERE THREAT HAS ENDED ACROSS NORTHEAST MONTANA THIS EVENING...THUS
ONE LAST UPDATE TO KILL THE REMAINING WATCHES. GILCHRIST
PREVIOUS SHORT TERM DISCUSSION...SYSTEM MOVING THROUGH THIS
AFTERNOON AND TONIGHT IS WORKING OUT AS PLANNED. HRRR MODEL
SHOWING THUNDERSTORMS TO FORM IN A QUASI-LINEAR FASHION AND TO
MOVE NORTHEAST THROUGH THE CWA LATER THIS AFTERNOON/EVENING. THIS
IS FURTHER NORTH THAN WHAT YESTERDAY/S MODELS DEPICTED. OUTFLOW
WINDS...BRIEF HEAVY RAIN AND SMALL HAIL SEEM TO BE THE MAIN
THREATS. NAM AND GFS ARE SHOWING 6 HOUR QPF BULLS EYES NEAR AN
INCH FOR TONIGHT SO WILL KEEP WORDING OF HEAVY RAIN GOING. DO NOT
EXPECT FLASH FLOODING BUT IT WILL BE A SLOPPY MESS IN MOST AREAS
COME MONDAY MORNING. DRIER CONDITIONS WILL MOVE IN FROM THE
SOUTHWEST LATE TONIGHT WITH ALL BUT THE NE ZONES DRY MONDAY
MORNING.
ON MONDAY...NAM/GFS IN AGREEMENT WITH SYSTEM BECOMING STACKED OVER S
SASK. CLEARING MAY MAKE IT NORTH INTO THE SOUTHERN ZONES...BUT
PROXIMITY TO STORM WILL KEEP NORTHERN ZONES CLOUDY WITH SCATTERED
SHOWERS. IT WILL BE WINDY TOO...SO A LAKE WIND ADVISORY LOOKS LIKELY.
MONDAY NIGHT AND TUESDAY...CLOSED SYSTEM GRADUALLY DRIFTS INTO
NORTHERN MINNESOTA. RESIDUAL MOISTURE WILL KEEP SKIES MAINLY CLOUDY
SCATTERED LIGHT SHOWERS ACROSS THE NORTH. WINDS SHOULD BE LIGHT AND
TEMPERATURES WILL BE SIMILAR TO MONDAY...SLIGHTLY BELOW NORMAL. TFJ
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
A SHORTWAVE MONDAY NIGHT INTO TUESDAY WILL BRING CHANCES FOR
SHOWERS AND THUNDERSTORMS. THEN...IT LOOKS LIKE TUESDAY NIGHT INTO
WEDNESDAY WILL BE BETWEEN SYSTEMS AND MAINLY DRY.
AN UPPER TROUGH WILL REMAIN QUASI-STATIONARY OVER THE WESTERN US
MOST OF THE WEEK. SW FLOW ALOFT FROM THIS TROUGH WILL MOVE INTO EASTERN
MONTANA ON WEDNESDAY AND REMAIN OVER THE AREA UNTIL SATURDAY.
THIS WILL BRING FREQUENT SHORTWAVES WITH UNSTABLE CONDITIONS INTO
THE FORECAST AREA WITH SLIGHT CHANCE TO CHANCE OF SHOWERS AND/OR
THUNDERSTORMS MOST OF THE PERIOD. AT THE SAME TIME...THE SW FLOW
ALOFT WILL BRING A WARMING TREND THROUGH THE WEEK.
A SHORTWAVE TROUGH MOVING INLAND FROM THE PACIFIC ON FRIDAY WILL
MOVE ACROSS MONTANA ON SATURDAY AND TURN THE FLOW ALOFT MORE
ZONAL THAT WILL CONTINUE INTO NEXT SUNDAY. CHANCES FOR SHOWERS AND
THUNDERSTORMS WILL CONTINUE. FORRESTER
&&
.AVIATION...
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO AFFECT MAINLY THE KSDY
AND KGDV TERMINALS THROUGH ABOUT 06Z. STORMS MAY BRING TEMPORARY
MVFR/IFR CEILINGS AND VISIBILITIES ALONG WITH GUSTY AND VARIABLE
WINDS. OTHERWISE EXPECT MAINLY VFR ACROSS ALL TERMINAL LOCATIONS
AFTER 06Z ALTHOUGH SOME MVFR SHOWERS TOWARD MORNING AND A PASSING
SHOWER STILL CANNOT BE RULED OUT. NORTHWEST WINDS AROUND 10 KTS.
WEST WINDS ON MONDAY MAY PICK UP TO 15 TO 25 KTS WITH HIGHER
GUSTS. MALIAWCO
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
807 PM CDT TUE MAY 20 2014
.SYNOPSIS...
ISSUED AT 312 PM CDT TUE MAY 20 2014
A FAIRLY ACTIVE H5 PATTERN HAS DEVELOPED ACROSS THE
CONUS OVER THE PREVIOUS 24 HOURS. LOW PRESSURE WAS ANCHORED OFF THE
COAST OF MAINE...WITH ANOTHER LOW OVER NORTHERN PORTIONS OF THE
CENTRAL VALLEY OF CALIFORNIA. ANOTHER LOW WAS PRESENT OVER THE
ALASKA PANHANDLE WITH ANOTHER LOW OVER NORTHERN PORTIONS OF THE
NORTHWEST TERRITORIES OF CANADA. CLOSER TO THE CENTRAL CONUS...A
NICE SHORTWAVE TROUGH WAS NOTED OVER SWRN MANITOBA. A 50+KT JET
STREAK EXTENDED ACROSS NRN WYOMING INTO SOUTH DAKOTA AND CENTRAL
MINNESOTA THIS MORNING. THIS FEATURE HAS LED TO THE DEVELOPMENT OF
SOME LIGHT RAIN SHOWERS ACROSS NORTHERN NEBRASKA AND SRN SOUTH
DAKOTA. THIS ACTIVITY HAS REMAINED VERY LIGHT THIS MORNING WITH ONLY
TRACE AMOUNTS TO A FEW HUNDREDTHS OF AN INCH REPORTED. AT THE
SURFACE...A TROUGH OF LOW PRESSURE EXTENDED FROM SERN MONTANA INTO
NERN COLORADO. FURTHER EAST...A COLD FRONT EXTENDED FROM FAR SWRN
NEBRASKA INTO THE SOUTHERN TEXAS PANHANDLE. TEMPERATURES SOUTH OF
THIS FEATURE WERE IN THE MID 80S TO 90S. WEST AND NORTH OF THE
FRONT...READINGS WERE IN THE 70S TO LOWER 80S. AS OF 2 PM
CDT...TEMPERATURES ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA...RANGED FROM 73 AT VALENTINE...TO 83 AT BROKEN BOW.
&&
.UPDATE...
ISSUED AT 807 PM CDT TUE MAY 20 2014
UPDATE TO THE FORECAST TO INCLUDE SEVERE WORDING. PLEASE REFER TO
WCN 162 FOR FURTHER DETAILS CONCERNING THE WATCH. CURRENTLY
WATCHING TWO AREAS OF CONVECTION...FIRST ACROSS THE WESTERN
PANHANDLE...AND THE SECOND IN NORTHEASTERN COLORADO. CONVECTION
ALLOWING MODELS INDICATE THAT THESE STORMS WILL CONTINUE
EASTWARD...POSSIBLY IMPACTING SOUTHWESTERN AND WESTERN PORTIONS OF
THE CWA THIS EVENING/OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 312 PM CDT TUE MAY 20 2014
ALTOCUMULUS AND SPRINKLES BISECTING THE LBF CWA A RESULT OF REMNANTS
OF EARLIER CONVECTION AND WEAK MID LEVEL FORCING IN ASSOCIATION WITH
MID LEVEL INSTABILITY. SUBSEQUENT MID LEVEL FRONTOGENESIS HAS
DEVELOPED ACCORDING TO THE RAP FURTHER SOUTHEAST IS GENERATING SOME
ADDITIONAL CLOUD COVER ACROSS THE FAR EASTERN PORTION OF THE AREA.
FURTHER WEST...CONVECTION IS DEVELOPING NEAR THE LARAMIE RANGE IN WY
VERY SIMILAR TO THE WAY CONVECTION ALLOWING MODELS HAVE BEEN
SUGGESTING WITH EACH RUN. THE HRRR HAS THIS HANDLED WELL AND IN THE
ABSENCE OF SIGNIFICANT LARGE SCALE FORCING...THIS CONVECTION IS
PROGGED TO REMAIN ISOLATED AND DOES HAVE SOME POTENTIAL TO RETAIN
SUPERCELL STRUCTURE AS IT MOVES EAST INTO THE PANHANDLE THIS
EVENING...AGAIN ACCORDING TO THE HRRR AND ITS ENSEMBLE OF UPDRAFT
HELICITY. SHOULD THIS CLUSTER OF STORMS HOLD TOGETHER TONIGHT THERE
IS SOME SUPPORT IN THE SHORT RANGE MODELS FOR ELEVATED INSTABILITY
IN THE PANHANDLE. FURTHER SOUTH INTO SOUTHWEST NEB...SOME CONVECTION
DEVELOPING NEAR THE CO FRONT RANGE AND MODELS KEEP THIS PROGRESSING
EWD AS WELL SO PRECIP CHANCES ADDED TO THE SOUTHWEST OVERNIGHT.
HOWEVER...CONFIDENCE IN THIS SCENARIO IS ONLY MODERATE TO MAINTAIN
ITS STRUCTURE INTO THE SW DUE TO A LACK OF A LOW LEVEL JET.
OTHERWISE...LOW TEMPS IN THE UPPER 40S TO LOW 50S LOOKS GOOD BASED
ON LOW LEVEL MOISTURE PROFILE BEING MAINTAINED OVERNIGHT.
UPPER LEVEL RIDGE BUILDS INTO THE CENTRAL PLAINS AS THE SOUTHWESTERN
STATES UPPER LOW SLOWLY MOVES EWD. MAY BE SOME CONVECTIVE DEBRIS
ONCE AGAIN WED MORNING ESPECIALLY ACROSS WRN NEB. IN ADDITION...NAM
SUGGESTS POTENTIAL FOR STRATUS ALONG AND JUST EAST OF THE FRONTAL
POSITION IN FAVORED AREA OF UPSLOPE FLOW. THEN UPPER PV ANOMALY TO
MOVE INTO THE CENTRAL ROCKIES TOMORROW WHICH SHOULD ALLOW FOR A MUCH
BROADER COVERAGE OF CONVECTION AS THE UPPER FORCING SERVES TO
ENHANCE CONVERGENCE ALONG THE FRONT WHICH WILL BE LOCATED FROM NW KS
IN TO SERN WY. THIS DEVELOPMENT SHOULD BE DIURNALLY DRIVEN AND MAY
BE LIMITED DEPENDING ON ULTIMATE DEVELOPMENT OF STRATUS IN THE WEST.
TEMPS SHOULD BE COOLER WED THOUGH MODELS HAVE BEEN A LITTLE TOO COOL
IN THE SOUTH THE LAST COUPLE OF DAYS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 312 PM CDT TUE MAY 20 2014
WEDNESDAY NIGHT THROUGH TUESDAY...THE MAIN FORECAST
CHALLENGE WILL BE PRECIPITATION CHANCES IN THE MID RANGE AND
EXTENDED FORECAST. A PERSISTENT UPPER LEVEL TROUGH OF LOW PRESSURE
WILL REMAIN ANCHORED ACROSS THE WESTERN CONUS. PERSISTENT LOW LEVEL
MOISTURE WILL FLOW INTO WESTERN AND NORTH CENTRAL NEBRASKA THANKS TO
LOW LEVEL EASTERLY WINDS.
FOR WEDNESDAY NIGHT THROUGH FRIDAY...WEDNESDAY NIGHT...STRONG TO
SEVERE STORMS ARE EXPECTED TO BE ONGOING ACROSS NERN COLORADO AND
NWRN KS INVOF OF THE SURFACE FRONTAL BOUNDARY. WITH SSWRLY STEERING
WINDS CONTINUING ACROSS THE HIGH PLAINS...ACTIVITY WILL LIFT NWD
INTO THE FORECAST AREA DURING THE EVENING HRS. THERE WILL REMAIN A
LARGE HAIL THREAT MAINLY ACROSS FAR SWRN NEBRASKA AND THE SERN
NEBRASKA PANHANDLE WHICH WILL BE IN CLOSER PROXIMITY TO THE FRONTAL
BOUNDARY. FARTHER NORTH...HAIL SIZE SHOULD DECREASE ACROSS THE
WESTERN SANDHILLS AND I80 CORRIDOR...HOWEVER SMALL HAIL WILL REMAIN
A THREAT GIVEN THE DEGREE OF ELEVATED INSTABILITY EXPECTED
OVERNIGHT. BOTH THE GFS AND NAM SOLNS THIS MORNING...ARE INDICATIVE
OF MCS DEVELOPMENT WEDS EVENING...WHICH WILL TRAVERSE THE CWA
OVERNIGHT. THIS SEEMS PLAUSIBLE GIVEN THE 30 TO 40 KT H85 WINDS
ACROSS THE SOUTHERN AND CENTRAL CWA OVERNIGHT WEDS NIGHT. INHERITED
FORECAST HAD POPS IN THE 30 TO 50 PERCENT RANGE FROM NORTH TO SOUTH
WEDS NIGHT WHICH REMAINS ON TRACK GIVEN THE LATEST STATISTICAL
GUIDANCE. A SIMILAR CONVECTIVE SETUP WILL COMMENCE FOR LATE THURSDAY
INTO THURSDAY NIGHT. A FRONTAL BOUNDARY WILL BE STALLED OUT OVER
NORTHEASTERN COLORADO AND NWRN KS. WITH HEATING AND THE ARRIVAL OF AN
UPPER LEVEL SHORTWAVE...THUNDERSTORMS WILL INITIATE DURING THE LATE
AFTERNOON HRS INVOF THE FRONT. THERE ARE SOME MODEL DIFFERENCES IN
THE LOCATION OF THE FRONTAL BOUNDARY THURSDAY AFTERNOON WITH THE NAM
SOLN BEING THE FARTHEST SOUTH. WITH MCS DEVELOPMENT PROBABLE
TOMORROW NIGHT...JUST WHERE THIS BOUNDARY WILL LIE DOWN THURSDAY
WILL BE HARD TO PINPOINT...AS WILL BE THE SEVERE THREAT.
HOWEVER...ANOTHER ROUND OF SCATTERED THUNDERSTORMS IS POSSIBLE
THURSDAY NIGHT AS ACTIVITY ALONG THE FRONT LIFTS NORTH INTO THE
FORECAST AREA. FAVORABLE CONDITIONS...BOTH ALOFT AND AT THE SURFACE
FOR PRECIPITATION...WILL CONTINUE INTO FRIDAY. PERSISTENT SWRLY FLOW
ALOFT...A FRONTAL BOUNDARY ACROSS SWRN NEBRASKA AND EASTERLY AND
SERLY WINDS IN THE BOUNDARY LAYER ARE EXPECTED FRIDAY INTO FRIDAY
NIGHT. THE THREAT FOR SEVERE STORMS FRIDAY AFTERNOON AND FRIDAY
NIGHT WILL HINGE ON THE LOCATION OF THE SURFACE FRONTAL
BOUNDARY...WHICH ATTM IS EXPECTED TO LIE EITHER OVER SWRN NEBRASKA
OR OFF TO THE SW IN NERN COLORADO AND NWRN KS. LIKE WEDNESDAY AND
THURSDAY...SCATTERED THUNDERSTORMS WILL LIFT NORTH AND
NORTHEAST...FROM THE FRONTAL BOUNDARY INTO WESTERN AND NORTH CENTRAL
NEBRASKA FRIDAY EVENING AND FRIDAY NIGHT AND CHANCE POPS WERE
CONTINUED.
FRIDAY NIGHT THROUGH TUESDAY...AN UPPER LEVEL TROUGH WILL PERSIST
ACROSS THE INTERMOUNTAIN WEST FRIDAY NIGHT THROUGH SUNDAY
NIGHT...BEFORE LIFTING ACROSS THE CENTRAL PLAINS ON MONDAY. THE
THREAT FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE
WEEKEND...MAINLY DURING THE LATE AFTERNOON AND EVENING HOURS AS
ABUNDANT LOW LEVEL MOISTURE REMAINS IN PLACE ACROSS THE FORECAST
AREA. ON MONDAY AND MONDAY NIGHT...THE MAIN UPPER LEVEL LOW WILL
LIFT NORTHEAST INTO THE CENTRAL PLAINS...TRACKING INTO THE LOWER
MISSOURI VALLEY ON TUESDAY. PRECIPITATION CHANCES WILL CONTINUE INTO
MONDAY...WITH DRIER CONDS EXPECTED MONDAY NIGHT INTO TUESDAY. HIGHS
WILL GENERALLY BE IN THE 70S...WITH 80S POSSIBLE NEXT
TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 623 PM CDT TUE MAY 20 2014
FOR THE KVTN AND KLBF 00Z TAFS...MAIN FORECAST CONCERN IS WHETHER
THE CONVECTION CURRENTLY FORMING OFF THE HIGH PLAINS OF EASTERN
WYOMING/COLORADO WILL IMPACT AREA TERMINALS OVERNIGHT.
ATTM...FORECAST CONFIDENCE DOES NOT WARRANT ANY TSRA MENTION IN THE
OFFICIAL TAF FORECAST FOR EITHER KLBF OR KVTN. NOTE HOWEVER SEVERAL
CONVECTION ALLOWING MODELS /SUCH AS THE HRRR/ CONTINUE TO INDICATE
TWO DISTINCT AREAS OF STORMS...CURRENTLY OVER EASTERN COLORADO NEAR
DIA AND OVER FAR EASTERN WY BETWEEN KTOR/KBFF...WILL SUSTAIN
THEMSELVES AND EACH PASS TO THE SOUTH AND NORTH RESPECTIVELY OF KLBF
AROUND 06Z TONIGHT. UPDATES MAY BE NEEDED TO INCLUDE CONVECTION.
STILL WATCHING FOR THE POTENTIAL OF STRATUS OVERNIGHT WHICH WILL
FAVOR THE PANHANDLE AND AREAS OF SOUTHWEST NEBRASKA /POSSIBLY
IMPACTING KLBF/. BUT AS THE CASE WITH THE STORMS...CONFIDENCE IS
LOW...WILL NOT INCLUDE A MVFR MENTION IN THE TAF AT LBF FOR NOW.
OTHERWISE CONVECTIVE DEBRIS FROM EXPECTED STORMS THIS EVENING MAY
CONTINUE OVERNIGHT...WITH LIGHT SHOWERS POSSIBLE FOR THE SANDHILLS
THROUGH DAWN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JACOBS
SYNOPSIS...CLB
SHORT TERM...JWS
LONG TERM...CLB
AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
623 PM CDT TUE MAY 20 2014
.SYNOPSIS...
ISSUED AT 312 PM CDT TUE MAY 20 2014
A FAIRLY ACTIVE H5 PATTERN HAS DEVELOPED ACROSS THE
CONUS OVER THE PREVIOUS 24 HOURS. LOW PRESSURE WAS ANCHORED OFF THE
COAST OF MAINE...WITH ANOTHER LOW OVER NORTHERN PORTIONS OF THE
CENTRAL VALLEY OF CALIFORNIA. ANOTHER LOW WAS PRESENT OVER THE
ALASKA PANHANDLE WITH ANOTHER LOW OVER NORTHERN PORTIONS OF THE
NORTHWEST TERRITORIES OF CANADA. CLOSER TO THE CENTRAL CONUS...A
NICE SHORTWAVE TROUGH WAS NOTED OVER SWRN MANITOBA. A 50+KT JET
STREAK EXTENDED ACROSS NRN WYOMING INTO SOUTH DAKOTA AND CENTRAL
MINNESOTA THIS MORNING. THIS FEATURE HAS LED TO THE DEVELOPMENT OF
SOME LIGHT RAIN SHOWERS ACROSS NORTHERN NEBRASKA AND SRN SOUTH
DAKOTA. THIS ACTIVITY HAS REMAINED VERY LIGHT THIS MORNING WITH ONLY
TRACE AMOUNTS TO A FEW HUNDREDTHS OF AN INCH REPORTED. AT THE
SURFACE...A TROUGH OF LOW PRESSURE EXTENDED FROM SERN MONTANA INTO
NERN COLORADO. FURTHER EAST...A COLD FRONT EXTENDED FROM FAR SWRN
NEBRASKA INTO THE SOUTHERN TEXAS PANHANDLE. TEMPERATURES SOUTH OF
THIS FEATURE WERE IN THE MID 80S TO 90S. WEST AND NORTH OF THE
FRONT...READINGS WERE IN THE 70S TO LOWER 80S. AS OF 2 PM
CDT...TEMPERATURES ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA...RANGED FROM 73 AT VALENTINE...TO 83 AT BROKEN BOW.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 312 PM CDT TUE MAY 20 2014
ALTOCUMULUS AND SPRINKLES BISECTING THE LBF CWA A RESULT OF REMNANTS
OF EARLIER CONVECTION AND WEAK MID LEVEL FORCING IN ASSOCIATION WITH
MID LEVEL INSTABILITY. SUBSEQUENT MID LEVEL FRONTOGENESIS HAS
DEVELOPED ACCORDING TO THE RAP FURTHER SOUTHEAST IS GENERATING SOME
ADDITIONAL CLOUD COVER ACROSS THE FAR EASTERN PORTION OF THE AREA.
FURTHER WEST...CONVECTION IS DEVELOPING NEAR THE LARAMIE RANGE IN WY
VERY SIMILAR TO THE WAY CONVECTION ALLOWING MODELS HAVE BEEN
SUGGESTING WITH EACH RUN. THE HRRR HAS THIS HANDLED WELL AND IN THE
ABSENCE OF SIGNIFICANT LARGE SCALE FORCING...THIS CONVECTION IS
PROGGED TO REMAIN ISOLATED AND DOES HAVE SOME POTENTIAL TO RETAIN
SUPERCELL STRUCTURE AS IT MOVES EAST INTO THE PANHANDLE THIS
EVENING...AGAIN ACCORDING TO THE HRRR AND ITS ENSEMBLE OF UPDRAFT
HELICITY. SHOULD THIS CLUSTER OF STORMS HOLD TOGETHER TONIGHT THERE
IS SOME SUPPORT IN THE SHORT RANGE MODELS FOR ELEVATED INSTABILITY
IN THE PANHANDLE. FURTHER SOUTH INTO SOUTHWEST NEB...SOME CONVECTION
DEVELOPING NEAR THE CO FRONT RANGE AND MODELS KEEP THIS PROGRESSING
EWD AS WELL SO PRECIP CHANCES ADDED TO THE SOUTHWEST OVERNIGHT.
HOWEVER...CONFIDENCE IN THIS SCENARIO IS ONLY MODERATE TO MAINTAIN
ITS STRUCTURE INTO THE SW DUE TO A LACK OF A LOW LEVEL JET.
OTHERWISE...LOW TEMPS IN THE UPPER 40S TO LOW 50S LOOKS GOOD BASED
ON LOW LEVEL MOISTURE PROFILE BEING MAINTAINED OVERNIGHT.
UPPER LEVEL RIDGE BUILDS INTO THE CENTRAL PLAINS AS THE SOUTHWESTERN
STATES UPPER LOW SLOWLY MOVES EWD. MAY BE SOME CONVECTIVE DEBRIS
ONCE AGAIN WED MORNING ESPECIALLY ACROSS WRN NEB. IN ADDITION...NAM
SUGGESTS POTENTIAL FOR STRATUS ALONG AND JUST EAST OF THE FRONTAL
POSITION IN FAVORED AREA OF UPSLOPE FLOW. THEN UPPER PV ANOMALY TO
MOVE INTO THE CENTRAL ROCKIES TOMORROW WHICH SHOULD ALLOW FOR A MUCH
BROADER COVERAGE OF CONVECTION AS THE UPPER FORCING SERVES TO
ENHANCE CONVERGENCE ALONG THE FRONT WHICH WILL BE LOCATED FROM NW KS
IN TO SERN WY. THIS DEVELOPMENT SHOULD BE DIURNALLY DRIVEN AND MAY
BE LIMITED DEPENDING ON ULTIMATE DEVELOPMENT OF STRATUS IN THE WEST.
TEMPS SHOULD BE COOLER WED THOUGH MODELS HAVE BEEN A LITTLE TOO COOL
IN THE SOUTH THE LAST COUPLE OF DAYS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 312 PM CDT TUE MAY 20 2014
WEDNESDAY NIGHT THROUGH TUESDAY...THE MAIN FORECAST
CHALLENGE WILL BE PRECIPITATION CHANCES IN THE MID RANGE AND
EXTENDED FORECAST. A PERSISTENT UPPER LEVEL TROUGH OF LOW PRESSURE
WILL REMAIN ANCHORED ACROSS THE WESTERN CONUS. PERSISTENT LOW LEVEL
MOISTURE WILL FLOW INTO WESTERN AND NORTH CENTRAL NEBRASKA THANKS TO
LOW LEVEL EASTERLY WINDS.
FOR WEDNESDAY NIGHT THROUGH FRIDAY...WEDNESDAY NIGHT...STRONG TO
SEVERE STORMS ARE EXPECTED TO BE ONGOING ACROSS NERN COLORADO AND
NWRN KS INVOF OF THE SURFACE FRONTAL BOUNDARY. WITH SSWRLY STEERING
WINDS CONTINUING ACROSS THE HIGH PLAINS...ACTIVITY WILL LIFT NWD
INTO THE FORECAST AREA DURING THE EVENING HRS. THERE WILL REMAIN A
LARGE HAIL THREAT MAINLY ACROSS FAR SWRN NEBRASKA AND THE SERN
NEBRASKA PANHANDLE WHICH WILL BE IN CLOSER PROXIMITY TO THE FRONTAL
BOUNDARY. FARTHER NORTH...HAIL SIZE SHOULD DECREASE ACROSS THE
WESTERN SANDHILLS AND I80 CORRIDOR...HOWEVER SMALL HAIL WILL REMAIN
A THREAT GIVEN THE DEGREE OF ELEVATED INSTABILITY EXPECTED
OVERNIGHT. BOTH THE GFS AND NAM SOLNS THIS MORNING...ARE INDICATIVE
OF MCS DEVELOPMENT WEDS EVENING...WHICH WILL TRAVERSE THE CWA
OVERNIGHT. THIS SEEMS PLAUSIBLE GIVEN THE 30 TO 40 KT H85 WINDS
ACROSS THE SOUTHERN AND CENTRAL CWA OVERNIGHT WEDS NIGHT. INHERITED
FORECAST HAD POPS IN THE 30 TO 50 PERCENT RANGE FROM NORTH TO SOUTH
WEDS NIGHT WHICH REMAINS ON TRACK GIVEN THE LATEST STATISTICAL
GUIDANCE. A SIMILAR CONVECTIVE SETUP WILL COMMENCE FOR LATE THURSDAY
INTO THURSDAY NIGHT. A FRONTAL BOUNDARY WILL BE STALLED OUT OVER
NORTHEASTERN COLORADO AND NWRN KS. WITH HEATING AND THE ARRIVAL OF AN
UPPER LEVEL SHORTWAVE...THUNDERSTORMS WILL INITIATE DURING THE LATE
AFTERNOON HRS INVOF THE FRONT. THERE ARE SOME MODEL DIFFERENCES IN
THE LOCATION OF THE FRONTAL BOUNDARY THURSDAY AFTERNOON WITH THE NAM
SOLN BEING THE FARTHEST SOUTH. WITH MCS DEVELOPMENT PROBABLE
TOMORROW NIGHT...JUST WHERE THIS BOUNDARY WILL LIE DOWN THURSDAY
WILL BE HARD TO PINPOINT...AS WILL BE THE SEVERE THREAT.
HOWEVER...ANOTHER ROUND OF SCATTERED THUNDERSTORMS IS POSSIBLE
THURSDAY NIGHT AS ACTIVITY ALONG THE FRONT LIFTS NORTH INTO THE
FORECAST AREA. FAVORABLE CONDITIONS...BOTH ALOFT AND AT THE SURFACE
FOR PRECIPITATION...WILL CONTINUE INTO FRIDAY. PERSISTENT SWRLY FLOW
ALOFT...A FRONTAL BOUNDARY ACROSS SWRN NEBRASKA AND EASTERLY AND
SERLY WINDS IN THE BOUNDARY LAYER ARE EXPECTED FRIDAY INTO FRIDAY
NIGHT. THE THREAT FOR SEVERE STORMS FRIDAY AFTERNOON AND FRIDAY
NIGHT WILL HINGE ON THE LOCATION OF THE SURFACE FRONTAL
BOUNDARY...WHICH ATTM IS EXPECTED TO LIE EITHER OVER SWRN NEBRASKA
OR OFF TO THE SW IN NERN COLORADO AND NWRN KS. LIKE WEDNESDAY AND
THURSDAY...SCATTERED THUNDERSTORMS WILL LIFT NORTH AND
NORTHEAST...FROM THE FRONTAL BOUNDARY INTO WESTERN AND NORTH CENTRAL
NEBRASKA FRIDAY EVENING AND FRIDAY NIGHT AND CHANCE POPS WERE
CONTINUED.
FRIDAY NIGHT THROUGH TUESDAY...AN UPPER LEVEL TROUGH WILL PERSIST
ACROSS THE INTERMOUNTAIN WEST FRIDAY NIGHT THROUGH SUNDAY
NIGHT...BEFORE LIFTING ACROSS THE CENTRAL PLAINS ON MONDAY. THE
THREAT FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE
WEEKEND...MAINLY DURING THE LATE AFTERNOON AND EVENING HOURS AS
ABUNDANT LOW LEVEL MOISTURE REMAINS IN PLACE ACROSS THE FORECAST
AREA. ON MONDAY AND MONDAY NIGHT...THE MAIN UPPER LEVEL LOW WILL
LIFT NORTHEAST INTO THE CENTRAL PLAINS...TRACKING INTO THE LOWER
MISSOURI VALLEY ON TUESDAY. PRECIPITATION CHANCES WILL CONTINUE INTO
MONDAY...WITH DRIER CONDS EXPECTED MONDAY NIGHT INTO TUESDAY. HIGHS
WILL GENERALLY BE IN THE 70S...WITH 80S POSSIBLE NEXT
TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 623 PM CDT TUE MAY 20 2014
FOR THE KVTN AND KLBF 00Z TAFS...MAIN FORECAST CONCERN IS WHETHER
THE CONVECTION CURRENTLY FORMING OFF THE HIGH PLAINS OF EASTERN
WYOMING/COLORADO WILL IMPACT AREA TERMINALS OVERNIGHT.
ATTM...FORECAST CONFIDENCE DOES NOT WARRANT ANY TSRA MENTION IN THE
OFFICIAL TAF FORECAST FOR EITHER KLBF OR KVTN. NOTE HOWEVER SEVERAL
CONVECTION ALLOWING MODELS /SUCH AS THE HRRR/ CONTINUE TO INDICATE
TWO DISTINCT AREAS OF STORMS...CURRENTLY OVER EASTERN COLORADO NEAR
DIA AND OVER FAR EASTERN WY BETWEEN KTOR/KBFF...WILL SUSTAIN
THEMSELVES AND EACH PASS TO THE SOUTH AND NORTH RESPECTIVELY OF KLBF
AROUND 06Z TONIGHT. UPDATES MAY BE NEEDED TO INCLUDE CONVECTION.
STILL WATCHING FOR THE POTENTIAL OF STRATUS OVERNIGHT WHICH WILL
FAVOR THE PANHANDLE AND AREAS OF SOUTHWEST NEBRASKA /POSSIBLY
IMPACTING KLBF/. BUT AS THE CASE WITH THE STORMS...CONFIDENCE IS
LOW...WILL NOT INCLUDE A MVFR MENTION IN THE TAF AT LBF FOR NOW.
OTHERWISE CONVECTIVE DEBRIS FROM EXPECTED STORMS THIS EVENING MAY
CONTINUE OVERNIGHT...WITH LIGHT SHOWERS POSSIBLE FOR THE SANDHILLS
THROUGH DAWN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...JWS
LONG TERM...CLB
AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
307 PM CDT MON MAY 19 2014
.SYNOPSIS...
ISSUED AT 305 PM CDT MON MAY 19 2014
H5 ANALYSIS FROM THIS MORNING IS INDICATING A BROAD LOW AMPLITUDE
RIDGE ACROSS THE UPPER MISSISSIPPI VALLEY. FURTHER WEST...A STRONG
SHORTWAVE WAS PUSHING ON SHORE ALONG THE WASHINGTON AND OREGON
COASTS. HT FALLS WERE MOST PRONOUNCED OVER WYOMING AND EASTERN MT
WITH 40 TO 50 METER FALLS NOTED. FURTHER SOUTH AND EAST...WEAK HT
FALLS OF 10 TO 30 METERS WERE NOTED FROM WESTERN NEBRASKA INTO
WESTERN SOUTH DAKOTA AND CENTRAL NORTH DAKOTA. AT THE SURFACE...LOW
PRESSURE WAS NOTED OVER NRN SD AND NORTH CENTRAL KS. A FRONTAL
BOUNDARY EXTENDED ACROSS CENTRAL NEBRASKA. EAST OF THIS
FEATURE...WINDS WERE SOUTHERLY WITH NORTHERLY WINDS NOTED WEST OF
THIS FEATURE. A DRYLINE EXTENDED FROM JUST EAST OF IMPERIAL...NNWD
INTO THE NORTHERN NEBRASKA PANHANDLE. DEW POINTS EAST OF THIS
FEATURE WERE IN THE MIDDLE TO UPPER 50S...WHILE WEST OF THIS
FEATURE...DEW POINTS WERE IN THE 40S. RADAR IMAGERY AS OF 2 PM
CDT...SHOWS SOME NICE RETURNS BEGINNING TO DEVELOP INVOF THE I25
CORRIDOR IN EASTERN WYOMING...FROM NORTH OF CHEYENNE TO SOUTHEAST OF
DOUGLAS. OTHER ECHOES WERE NOTED OVER THE NORTHERN NEBRASKA
PANHANDLE INTO SWRN SOUTH DAKOTA. BASED ON SFC OBS...MUCH OF THIS
PCPN ISN/T REACHING THE GROUND ATTM. AS OF 2 PM CDT...UNDER MOSTLY
CLEAR SKIES...TEMPERATURES RANGED FROM 73 AT VALENTINE...TO 85 AT
IMPERIAL.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 305 PM CDT MON MAY 19 2014
THUNDERSTORM CHANCES ARE THE MAIN FORECASTING CONCERN FOR TONIGHT
AND TUESDAY. A TANDEM OF SHORTWAVES WILL LIFT INTO THE HIGH PLAINS
OVER THE NEXT 3 TO 6 HOURS. THE FIRST WILL LIFT FROM EASTERN WYOMING
INTO THE NORTHERN NEBRASKA PANHANDLE...THEN NORTHERN NEBRASKA. THE
SECOND WILL LIFT INTO THE SANDHILLS FROM NERN COLORADO. THE FIRST
DISTURBANCE HAS ALREADY LED TO SOME HIGH BASED SHOWERS OVER THE HIGH
PLAINS OF EASTERN WYOMING. AS THIS ACTIVITY MOVES EAST...IT SHOULD
BECOME BETTER ORGANIZED...LIFTING ACROSS NORTH CENTRAL NEBRASKA
THROUGH THE EVENING HOURS. FURTHER SOUTH...THE SECOND SHORTWAVE WILL
LIFT EAST INTO THE WESTERN SANDHILLS THIS EVENING. CAP STRENGTH WILL
REMAIN IN PLACE THROUGH 00Z WHERE IT BEGINS TO ERODE FROM OGALLALA
TO THEDFORD. IN THESE AREAS...AM EXPECTING CONVECTIVE INITIATION
AROUND THE 6 TO 7 PM CDT TIME FRAME THIS EVENING. BULK SHEAR IS IN
THE 35 TO 45 KT RANGE NEAR THE INITIATION POINT...HOWEVER...IT FALLS
OFF TO AROUND 30 KTS EAST OF HIGHWAY 183...SO AM EXPECTING THE MAIN
SEVERE THREAT TO BE CONFINED TO THE SANDHILLS NORTH OF INTERSTATE 80
AND WEST OF HIGHWAY 183. ISOLATED COVERAGE IS EXPECTED AND IS
SUPPORTED BY THE LATEST 4KM WRF AND HRRR SOLNS WHICH DEVELOP
STRONG...BUT ISOLATED STORMS ACROSS THE SANDHILLS THIS EVENING. AS
FOR SEVERE TYPES...CONTINUED THINKING IS LARGE HAIL FOR THE MAIN
SEVERE TYPE AS LOW LEVEL HELICITIES ARE NOT OVERLY IMPRESSIVE THIS
EVENING. WET BULB ZEROS AROUND 8000 FT AGL FAVOR LARGE HAIL AS WELL.
WE MAY SEE SOME GUSTY WINDS INVOF ANY STORMS...HOWEVER...SINCE
LINEAR SEGMENTS ARE NOT EXPECTED...WIDESPREAD SEVERE WINDS ARE NOT
ANTICIPATED ATTM. CONVECTIVE ACTIVITY IS EXPECTED TO MOVE EAST OF
THE FORECAST AREA BY LATE EVENING...HOWEVER...SOME LIGHT RAIN
SHOWERS WILL CONTINUE TO BE A THREAT IN THE NORTHWESTERN CWA WHERE
MID LEVEL PERSISTS INTO THE OVERNIGHT. FOR TOMORROW...TEMPERATURES
WILL COOL SLIGHTLY AS A FRONTAL BOUNDARY IS FORCED SOUTH INTO
KANSAS. THE MAIN THREAT FOR PCPN WILL FOLLOW. WITH THE EXCEPTION OF
THE WESTERN FORECAST AREA...MAINLY DRY CONDS WILL REMAIN IN PLACE.
HIGHS TUESDAY WILL RANGE FROM AROUND 70 IN THE NORTHWEST...TO NEAR
80 IN THE SOUTHEAST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 305 PM CDT MON MAY 19 2014
FOR TUESDAY NIGHT...THE 12Z NAM12 AND GFS40 ARE SIMILAR WITH THE
LOCATION OF THE QUASI-STATIONARY FRONT ACROSS NORTHEAST TO SOUTHWEST
KANSAS WITH THE 0-2KM THETA-E RIDGE ALONG THE KANSAS-NEBRASKA
BORDER. THE GREATEST INSTABILITY IS FROM SOUTHEAST NEBRASKA TO NORTH
CENTRAL KANSAS. THERE IS SOME MARGINAL INSTABILITY EXTENDING INTO
THE WESTERN NEBRASKA SANDHILLS AND THE PANHANDLE AND THUNDERSTORMS
ARE POSSIBLE TUESDAY EVENING. THE CONVECTIVE POTENTIAL ENERGY IS
LESS THAN 1000J/KG...SO SEVERE THUNDERSTORMS ARE UNLIKELY.
BY WEDNESDAY AFTERNOON...A FINGER OF THE THETA-E RIDGE EXTENDS
NORTHWESTWARD INTO THE SOUTHERN NEBRASKA PANHANDLE ALONG AN INVERTED
SURFACE TROUGH. WITH SURFACE-BASED CONVECTIVE POTENTIAL ENERGY
(CAPE) OF 2000J/KG WEDNESDAY EVENING AND 0-6KM BULK SHEAR OF
40-50KT...SOME STRONG THUNDERSTORMS SHOULD DEVELOP IN SOUTHWEST
NEBRASKA...POSSIBLY COMING ACROSS INTO THE WESTERN SANDHILLS. LATE
WEDNESDAY NIGHT...THE SURFACE BASED LIFTED INDICES SPREAD INTO
CENTRAL AND NORTH CENTRAL NEBRASKA...SO THERE IS A CHANCE OF
THUNDERSTORMS THERE AFTER 06Z
A SIMILAR SITUATION EXISTS FOR THURSDAY AFTERNOON AND FRIDAY
AFTERNOON. WITH THE FORECAST LOCATIONS OF THE MAXIMUM CAPE NEAR THE
NEBRASKA-KANSAS AND THE NEBRASKA-COLORADO BORDERS...THE HIGHEST
PROBABILITY OF STRONG THUNDERSTORMS WILL BE SOUTH OF INTERSTATE
HIGHWAY 80.
FOR SATURDAY AND SUNDAY...THE FRONT STARTS WASHING OUT. STILL WARM
ADVECTION OVER THE HIGH PLAINS BOUNDARY WILL BRING CONTINUE TO BRING
THE POSSIBILITY OF THUNDERSTORMS SATURDAY AFTERNOON AND EVENING. THE
CAPES WILL NOT BE AS HIGH...THOUGH THE HIGHER CAPES WILL COVER A
LARGER PART OF CENTRAL AND WESTERN NEBRASKA. THE 0-6KM BULK SHEAR IS
VERY WEAK...ONLY ABOUT 20KT OR LOWER...SO HEAVY RAIN WOULD BE THE
PRIMARY THREAT. BY SUNDAY...THE MOST FAVORABLE INSTABILITY WILL
SHIFT INTO EASTERN NEBRASKA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1238 PM CDT MON MAY 19 2014
ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP LATER
THIS AFTERNOON AND EARLY THIS EVENING ACROSS PORTIONS OF WESTERN
AND NORTH CENTRAL NEBRASKA. CONFIDENCE IN WHERE THESE STORMS
DEVELOP AND TRACK IS UP IN THE AIR SOMEWHAT. AT THIS TIME...BASED
ON GUIDANCE AND THE LATEST MODEL SOLNS...THE GREATEST THREAT FOR
STORMS IS OVER THE EASTERN PANHANDLE AND SANDHILLS. AT THE KLBF
AND KVTN TERMINALS...COVERAGE AND TIMING OF STORMS IS SUCH THAT
THEY WILL BE LEFT OUT OF THE 18Z TAF ISSUANCE. SCATTERED TO BROKEN
HIGH CLOUDS WILL CONTINUE INTO THE OVERNIGHT HRS WITH CIGS RANGING
FROM 10000 TO 20000 FT AGL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...CLB
LONG TERM...SPRINGER
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1238 PM CDT MON MAY 19 2014
.UPDATE...
ISSUED AT 1229 PM CDT MON MAY 19 2014
REMOVED POPS LATER THIS AFTERNOON...BETWEEN 21Z AND 00Z. MODELS
ARE TRENDING TOWARDS THIS SCENARIO...AND SIMULATED REFLECTIVITY
FROM THE HRRR AND NAM BOTH INDICATE PRECIPITATION CHANCES ARE
CLOSE TO NIL. I KEPT POPS THE SAME FOR TONIGHT...BUT THESE
CHANCES MAY NEED TO BE REMOVED AS WELL. WATCH FOR THE NEXT
UPDATE AS MORE DATA COMES IN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 432 AM CDT MON MAY 19 2014
MAIN CONCERNS INCLUDE A POTENTIAL FOR SEVERE WEATHER IN OUR NORTH
THIS EVENING...APPROACHING CRITICAL FIRE DANGER LATE THIS AFTERNOON
INTO EVENING IN OUR SOUTH...AND HIGHER TEMPERATURES THAN EARLIER
THOUGHT FOR HIGHS TODAY.
STRATUS IS DEVELOPING IN OUR NORTHERN CWA AND COULD TEMPORARILY GIVE
US A CLOUDY MORNING...BUT SHOULD BURN OFF FAIRLY QUICKLY WITH NICE
SUBSIDENCE SHOWING UP IN SOUNDINGS. WE COULD GET A ROGUE SHOWER OR
THUNDERSTORM THIS MORNING...ESPECIALLY NORTH/NORTHEAST WITH THE HELP
FROM A CONSIDERABLE LOW-LEVEL JET. THUNDERSTORMS HAVE ALREADY POPPED
UP IN NORTHERN NEBRASKA. IF ANY STORMS DEVELOP IN OUR AREA...HAIL
WOULD BE THE MAIN THING TO WORRY ABOUT AND THIS POTENTIAL WILL NOT
LAST LONG.
TODAY WE WILL LIE IN THE WARM SECTOR IN ADVANCE OF AN APPROACHING
COLD FRONT. I WENT MUCH MORE HEAVILY TOWARD THE NAM SOLUTION AS IT
DOES BEST IN THESE SITUATIONS. WITH ANY SKY COVER EXPECTED TO
DISSIPATE...WE SHOULD HAVE LITTLE PROBLEM GETTING WELL INTO THE 80S
IF NOT 90S IN OUR SOUTH. EVEN WITH PLENTY OF CIRRUS AROUND...IT
LOOKS LIKE AN OVEN AS THE WEAK BOUNDARY SLOWLY MAKES ITS WAY INTO
THE CWA BY AFTERNOON. CONSIDERING THE EXPECTED MIXING...SOME OF OUR
KANSAS COUNTIES COULD GET CLOSE TO CRITICAL FIRE WEATHER ISSUES LATE
THIS AFTERNOON INTO THIS EVENING. AS THE COLD FRONT
APPROACHES...HOWEVER...WIND SHOULD DROP OFF...SO THIS COULD BE A
LIMITING FACTOR FOR MAKING 3 HOURS OF WIND AND HUMIDITY...SO I WILL
JUST MENTION THIS IN THE HWO FOR NOW.
THIS EVENING COULD BE QUITE INTERESTING. WE WILL BE ON THE BACK SIDE
OF A PASSING SHORTWAVE RIDGE WITHIN SOUTHWEST FLOW. THERE IS DECENT
AGREEMENT WITH A SUBTLE PERTURBATION COMING IN THIS EVENING. ALONG
WITH THE SURFACE FRONT AND BREAKING CAP...WE COULD BE IN FOR SOME
SEVERE THUNDERSTORM DEVELOPMENT WITH DISCRETE CELLS FORMING A
POTENTIAL MCS LATER ON IN THE EVENING. EVEN AN ISOLATED TORNADO IS
NOT OUT OF THE QUESTION HERE. THIS WILL BE INCLUDED IN THE HWO AS
WELL. IF WE GET THIS TO FIRE...THE SCALE WILL BE RELATIVELY
SMALL...SO I DID NOT GO CRAZY WITH CHANCES OF PRECIPITATION FOR NOW.
I ACTUALLY RAISED LOW TEMPERATURES A BIT MORE FROM THE ALREADY MILD
PREVIOUS FORECAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 432 AM CDT MON MAY 19 2014
ALOFT: THE FLOW IS IN THE PROCESS OF AMPLIFYING. A WRN USA TROF WILL
REFORM AS THE LOW /CURRENTLY OFF THE PAC NW COAST/ DROPS SE AND CUTS
OFF OVER THE INTERMOUNTAIN W. THE MAIN BELT OF WESTERLIES WILL
BECOME REESTABLISHED OVER CANADA. MEANWHILE...A SUB-TROPICAL HIGH
WILL DEVELOP OVER THE GULF COAST STATES. ITS RIDGE AXIS WILL EXTENT
NW INTO THE CNTRL PLAINS.
NO NOTICEABLE SHORTWAVE TROFS WILL BE MOVING THRU HERE THRU WED
NIGHT. SO UPPER-LEVEL JET STREAKS AND THE LOW-LEVEL JET /LLJ/ WILL
BE THE PRIMARY DRIVERS OF CONVECTION.
SURFACE: THE COOL FRONT THAT CROSSES THE FCST AREA TODAY WILL BE
LOCATED FROM SW-NE ACROSS KS TOMORROW /MCI-ICT-DDC/. THIS FRONT WILL
REMAIN QUASI-STATIONARY THRU WED. CANADIAN HIGH PRES WILL EXPAND S
INTO THE NRN PLAINS TUE-WED.
HAZARDS: MULTIPLE TSTM THREATS EXIST WED NIGHT-SUN. ITS IMPOSSIBLE
IN THIS PATTERN TO TELL WHICH TIME PERIODS HAVE A GREATER RISK AS
WELL AS THE POTENTIAL COVERAGE. IF THE CAP IS NOT OVERWHELMING...
THERE IS POTENTIAL FOR MULTIPLE TSTM EPISODES THAT COULD RESULT IN
SEVERAL INCHES OF RAIN. CONFIDENCE IS LOW THOUGH.
THE DAILY DETAILS...
TUE: "SHOULD" BE A NICE DAY. A FEW DEGREES COOLER THAN TODAY BUT
STILL MUCH WARMER THAN NORMAL /10F/. HOWEVER...AM CONCERNED WE MAY
BE TOO LOW ON WINDS. I HAVE SEEN THIS BEFORE AND GOTTEN BURNED IN NE
FLOW COLD AIR ADVECTION. THE NAM IS THE TIGHEST WITH THE PRES
GRADIENT. FOR NOW THE FCST HAS BEEN NUDGED CLOSER TO THE NAM...BUT
WOULD NOT BE SURPRISED TO SEE NE 15-25G30 THRU EARLY AFTERNOON.
TUE NIGHT: THE LLJ SHOULD BE NO FACTOR. IT WILL BE ORIENTED TOWARD
THE MID MS VALLEY.
WED: A TOUCH COOLER THAN TUE. STILL LOOKING DRY.
WED NIGHT: MULTIPLE MODELS SEEM TO BE KEYING ON THIS TIME FRAME FOR
TSTM DEVELOPMENT. THE 00Z NAM/EC ARE THE MOST AGGRESSIVE AND AM NOT
EXACTLY SURE WHY. THE NOSE OF THE LLJ IS FCST TO BE ALONG THE WRN
KS/OK BORDER.
THU: MORE MODELS CLIMB ABOARD WITH INCREASING QPF...PARTICULARLY THE
GFS.
THIS OVERALL UPTREND IN POTENTIAL TSTM ACTIVITY APPEARS TIED TO THE
MODELS WANTING TO TRY AND DEVELOP TSTMS ALONG AND N OF THE FRONT
WHILE WASHING IT OUT WITH TSTM ACTIVITY. THIS COULD ALSO BE
ASSOCIATED WITH SUBTLE VORT MAXIMA BEING EJECTED OUT FROM THE CUT-
OFF LOW AND ROUNDING THE RIDGE.
WHILE AM SKEPTICAL...TSTMS CANT BE ENTIRELY RULED OUT. THERE WILL BE
AN E-W ORIENTED BAND OF HIGH QUALITY MOISTURE BETWEEN THE SURFACE
AND 850 MB FRONTS AND THE FCST AREA WILL BE ON THE NRN FRINGE OF THE
ELEVATED MIXED LAYER. THIS IS A PRIME LOCATION FOR TSTM DEVELOPMENT.
SO POPS WERE MAINTAINED BUT TRIMMED TO NO MORE THAN 30% THRU THE
DAYLIGHT HRS THU.
FRI-SUN: MINIMAL TIME SPENT IN THESE PERIODS. VERY LITTLE CHANGE
EXPECTED FROM THE TUE-THU TIME FRAMES. MODEL AGREEMENT CONTINUES
VERY GOOD ON BLOCKING HIGHS REMAINING OVER THE BERING SEA AND N
ATLANTIC FOR THE NEXT WEEK. THEREAFTER THE 00Z EC ENSEMBLE MEAN DOES
FCST THE SW USA CUT-OFF TO ADVANCE OVER THE PLAINS EARLY NEXT WEEK.
THE PATTERN IS LOOKING DECIDELY MORE SUMMERY WITH A 582 RIDGE FCST
TO REMAIN OVER THE PLAINS. HOWEVER...TEMPS WILL BE HEAVILY MODULATED
BY ANY TSTM ACTIVITY. FCST CONFIDENCE IS BELOW AVERAGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1229 PM CDT MON MAY 19 2014
VFR CONDITIONS WILL BE EXPECTED AT THE TERMINAL THROUGH THE VALID
TAF PERIOD. THERE WILL BE A LOW CHANGE FOR SOME SHOWERS AND
PERHAPS A THUNDERSTORM LATER TONIGHT...BUT CONFIDENCE IS TOO LOW
AT THIS TIME FOR THIS SCENARIO TO BE PLACE INTO THE TAF. IF A
THUNDERSTORM DOES COME TO FRUITION...IT WILL BE ASSOCIATED WITH A
WEAK COLD FRONT THAT SHOULD START TO TRANSITION THROUGH THE
TERMINAL LATE THIS AFTERNOON...AND WILL LIKELY STALL AROUND THE
AREA INTO TOMORROW.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...GUERRERO
SHORT TERM...HEINLEIN
LONG TERM...HALBLAUB
AVIATION...GUERRERO
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
924 PM CDT TUE MAY 20 2014
.UPDATE...
ISSUED AT 924 PM CDT TUE MAY 20 2014
FORECAST CHALLENGE FOR TONIGHT WILL BE SKY AND OVERNIGHT LOWS. LOW
CLOUDS OVER MUCH OF N CNTRL ND DID NOT BREAK UP AS MUCH AS PREV
THOUGHT...AND WILL INCREASE SKY ACROSS AREA GRADUALLY OVERNIGHT
TONIGHT. RUC 925-850 LYRD RH IDEA SEEMS MOST LIKELY...WITH OVC
SKIES SPREADING ACROSS AREAS THAT ARE CURRENTLY CLEAR AND NW NOT
CLEARING OUT UNTIL MID MORNING TOMORROW. WILL HOWEVER REMOVE POPS
FOR THE NIGHT AS RADAR UNIMPRESSIVE.
UPDATE ISSUED AT 643 PM CDT TUE MAY 20 2014
MAIN ISSUES FOR THIS UPDATE WILL BE PROBABILITY FOR PRECIP ACROSS
THE NORTH AND ADJUSTMENTS TO SKY GRIDS.
CANADIAN RADARS SHOWING SHOWERS ROTATING AROUND THE UPPER LOW
BEGINNING TO DRY UP AS THEY APPROACH SOUTHERN AND SOUTHEASTERN
MANITOBA. WILL REMOVE POPS THROUGH 06Z AND KEEP LOW CHANCE POPS
FOR LAKE OF THE WOODS AFT 06Z. MAY PULL PRIOR TO NEXT UPDATE IF
NOTHING BEGINS TO REDEVELOP...HOWEVER WILL REMOVE MENTION OF
THUNDER. FOR SKY...MUCH OF SOUTHEASTERN HALF OF CWA IS CLEAR OR
CLEARING IN THE CELLULAR CU OVER EASTERN ZONES. WILL HAVE MOSTLY
CLEAR WORDING THROUGH 06Z...WITH INCREASED CLOUD COVER AS CLOUDS
OVER THE DEVILS LAKE BASIN BEGIN TO FILL IN CLEAR AREAS. LOOKS
LIKE THIS WILL HOLD TOGETHER LONG ENOUGH TO KEEP NORTHEASTERN
PORTION OF CWA MOSTLY CLOUDY TOMORROW...WHICH WILL ALSO IMPACT
AVIATION (SEE DISCUSSION BELOW).
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM CDT TUE MAY 20 2014
FORECAST CHALLENGE CONCERNS LOW END PCPN CHANCES AND TEMPERATURES.
MODELS IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD AND WILL USE
BLEND.
SURFACE/UPPER LOW WILL CONTINUE TO PROPAGATE EAST ALONG THE
MN/CANADIAN BORDER OVERNIGHT. CU FIELD EXPANDING SOUTHWARD WITH
THICKEST CLOUD COVER ALONG A DVL-ROX LINE. AIRMASS NOT VERY
UNSTABLE UNDER MID LEVEL COOLER AIR WITH NIL CAPE. A FEW SHOWERS
APPROACHING THE N CENTRAL ND BORDER AREA OTHERWISE ANY RAIN STILL
FARTHER NORTH INTO CANADA. FOR THIS DO NOT HAVE A LOT OF
CONFIDENCE ON SHRA POTENTIAL LATER THIS AFTERNOON INTO THE
EVENING. MODELS FOR THE MOST PART KEEPING ANY SHRA ACTIVITY
HUGGING THE INTERNATIONAL BORDER. WILL MAINTAIN SOME SLIGHT/LOW
CHANCES BUT AGAIN CONFIDENCE NOT HIGH. COLD ADVECTION WILL PUSH
THROUGH THE FA TONIGHT SO EXPECT MINIMUMS GENERALLY IN THE 40S.
LOW LEVEL COLD POOL OVER FA TOMORROW MORNING WILL SHIFT EAST
ACROSS MN DURING THE DAY WITH SOME WARM ADVECTION FROM THE VALLEY
WEST. NOT A GREAT DEAL OF MIXING EXPECTED WITH SURFACE HIGH
OVERHEAD. CONVECTIVE TEMPERATURES INITIALLY LOW BUT RAISE DURING
THE DAY SO DO EXPECT SOLAR. FEEL OPERATIONAL MODELS OVERDONE ON
QPF WEDNESDAY AFTERNOON SO KEPT FORECAST DRY. OVERALL EXPECT
TEMPERATURES AROUND 5 DEGREES BLO SEASONAL NORMS.
LIGHT WINDS AND SKC SHOULD ALLOW TEMPERATURES TO DROP OFF INTO THE
LOW TO MID 40S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 315 PM CDT TUE MAY 20 2014
HIGH SHIFTS SLIGHTLY EAST THURSDAY WITH COLUMN CONTINUING TO WARM.
MIXING WILL STILL REMAIN LIGHT HOWEVER WITH SOLAR EXPECT
TEMPERATURES CLOSER TO NORMAL.
WITH WARM ADVECTION AND WARMER COLUMN IN PLACE MINIMUM TEMPERATURES
NOT AS COOL THURSDAY NIGHT. MAIN MOISTURE TRANSPORT AND RELATED
INSTABILITY WILL REMAIN WELL TO OUR WEST OVER THE WESTERN DAKOTAS.
LOW CONFIDENCE ON EASTWARD EXTENT OF ANY LATE NIGHT/EARLY MORNING
RESIDUAL PCPN SO LIMITED POPS TO THE FAR WESTERN FA.
MIXING AND SURFACE MOISTURE FLUX INCREASES FRIDAY. HOW WARM WE GET
WILL DEPEND ON DEGREE OF CLOUD COVER BUT OVERALL TEMPERATURES
SHOULD BE AT OR A LITTLE ABOVE AVERAGE. SOME INSTABILITY WORKS
INTO THE WESTERN FA HOWEVER WITH LACK OF LOW LEVEL FORCING FEEL FA
FOR THE MOST PART WILL BE DRY.
THE FRIDAY NIGHT THROUGH TUESDAY PERIOD FINALLY HAS A STRING OF DAYS
WITH WARMER TEMPERATURES. ALONG WITH THESE WARMER TEMPERATURES WILL
ALSO FEATURE A RETURN TO SOME HUMIDITY. RIDGING OVER THE CENTRAL
PART OF THE COUNTRY WILL SLOWLY BE REPLACED BY SOUTHWEST FLOW WITH A
CUTOFF LOW KICKING OUT INTO THE CENTRAL PLAINS. HIGH TEMPS EACH DAY
SHOULD RANGE IN THE UPPER 70S TO AROUND 80. UNFORTUNATELY THE
COMBINATION OF HEAT HUMIDITY AND SOUTHWEST FLOW MEANS AN INCREASED
CHANCE FOR SHOWERS AND TSTMS. ESSENTIALLY EACH DAY CARRIES SOME
MENTION OF PCPN BUT REALISTICALLY THERE WILL BE SOME DRY PERIODS.
JUST HARD TO NAIL DOWN THIS FAR OUT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 643 PM CDT TUE MAY 20 2014
FAR SHOULD REMAIN CLEAR FOR THE NIGHT. THE LOW CLOUDS OVER
NORTHEASTERN ND MAY CONTINUE TO DISSIPATE OVER THE NEXT SEVERAL
HOURS AND WILL KEEP VFR...HOWEVER THICKER CLOUDS OVER SOUTHERN
MANITOBA WILL LIKELY ROTATE INTO TVF/BJI AREAS AFT MIDNIGHT AND
HAVE BROUGHT THOSE SITES DOWN TO MVFR CIGS LATER TONIGHT THROUGH
ABOUT NOON TOMORROW. BREEZY NORTHWEST WINDS WILL SUBSIDE OVER NEXT
SEVERAL HOURS HOWEVER NW FLOW WILL CONTINUE THROUGH THE 00Z TAF PERIODS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...SPEICHER
SHORT TERM...VOELKER
LONG TERM...GODON/VOELKER
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
531 PM CDT MON MAY 19 2014
.UPDATE...
ISSUED AT 530 PM CDT MON MAY 19 2014
LATEST LOCAL/REGIONAL RADAR CONTINUES TO SHOW SCATTERED
THUNDERSTORMS IN NORTHWEST NORTH DAKOTA. RECENT SPOTTER REPORTS
HAVE BEEN CONSISTENT WITH PEA SIZED HAIL AND HEAVY DOWNPOURS WITH
CELLS MOVING ACROSS MCKENZIE COUNTY AND INTO THEODORE ROOSEVELT
PARK NORTH. OUR CURRENT SPECIAL WEATHER STATEMENT HANDLES THIS
AREA WELL AND WILL CONTINUE. CONCERN FOR THE NEXT COUPLE OF HOURS
IS THE SECONDARY AREA OF THUNDERSTORMS JUST READY TO APPROACH
SCOBEY MONTANA. REPORTS OF NICKEL SIZED HAIL WEST OF SCOBEY. THE
LATEST HRRR MAINTAINS REFLECTIVITY INTENSITY AS THIS AREA CROSSES
OUR NORTHWEST BORDER BETWEEN 00Z AND 03Z. IN ADDITION...ISOLATED
THUNDERSTORMS APPROACHING BAKER MONTANA WILL ALSO BE WATCHED THIS
EVENING AS THEY MOVE INTO THE SOUTHWEST. BOWMAN RADAR INDICATIVE
OF ISOLATED SHOWERS WITH POSSIBLE THUNDERSTORM DEVELOPMENT
SHORTLY. LASTLY...WILL WATCH FOR THE SOUTHERN JAMES RIVER VALLEY
FOR THUNDERSTORM DEVELOPMENT. SOME INDICATION PER RAP AND NAM THAT
WE COULD SEE SOMETHING THIS EVENING. ALL ACTIVITY IS FORECAST TO
GRADUALLY WEAKEN AND WANE BY 06Z TUESDAY. MAIN UPDATE WAS TO KEEP
SCATTERED THUNDERSTORMS GOING INTO THE MID EVENING HOURS NORTHWEST
AND KEEP SOME MENTION OF THUNDERSTORMS IN THE SOUTHWEST.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 300 PM CDT MON MAY 19 2014
THE MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD IS CONVECTIVE
TRENDS/COVERAGE/INTENSITY THROUGH THIS EVENING.
THE LATEST RUNS OF THE HRRR/WRF/RAP ALL INDICATING SHOWERS AND
STORMS TO DEVELOP OR ADVECT INTO PARTS OF THE FORECAST AREA THIS
AFTERNOON. ONE PRIMARY AREA WILL LIKELY BE THE NORTHWEST...WITH
CURRENT STORMS ONGOING IN NORTHEAST MONTANA...ADDED BY AN UPPER
LOW IN THE VICINITY. THE PRIMARY THREAT AREA FOR STRONG TO NEAR SEVERE
STORMS STILL APPEARS TO BE IN THE JAMES RIVER VALLEY AND...WHERE
THE MOST FAVORABLE DEEP LAYER SHEAR...MOISTURE...AND MID-LEVEL
LAPSE RATES ARE LOCATED. THIS AREA REMAINS OUTLOOKED IN THE 5
PERCENT RISK AREA FOR HAIL. WILL MAINTAIN CHANCE POPS IN THE NORTH
AND THROUGH THE JAMES RIVER VALLEY...WITH SLIGHT CHANCE POPS DOWN
TO NEAR TO INTERSTATE 94 CORRIDOR.
SHOWERS AND ISOLATED THUNDERSTORMS WILL DIMINISH THIS EVENING. A SECONDARY
COLD FRONT WILL DROP SOUTH INTO THE STATE OVERNIGHT...ACCOMPANIED BY
STRATUS. HOWEVER...ADDITIONAL RAIN WILL LIKELY STAY NORTH OF THE BORDER.
ON TUESDAY...EXPECT SOMEWHAT COOLER TEMPERATURES WITH A FEW SHOWERS
POSSIBLE ACROSS THE FAR NORTH DURING THE AFTERNOON.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 300 PM CDT MON MAY 19 2014
TUESDAY NIGHT AND WEDNESDAY...SURFACE HIGH PRESSURE MOVES INTO THE
STATE ALONG WITH THE EXITING OF AN UPPER LEVEL SHORTWAVE. COOL AND
DRY WITH TUESDAY NIGHT LOWS FROM THE UPPER 30S TO LOWER 40S. MOSTLY
SUNNY ON WEDNESDAY WITH HIGHS IN THE 60S.
WEDNESDAY NIGHT AND THURSDAY...THE SURFACE HIGH IS CENTERED EAST OF
THE FORECAST AREA WITH SOUTHERLY SURFACE FLOW AND INCREASING
DEWPOINTS. THE MODELS ARE IN AGREEMENT WITH SOME SHORTWAVE ENERGY
MOVING NORTH/NORTHEASTWARD FROM A LONGWAVE TROUGH OVER THE ROCKIES.
CHANCES OF THUNDERSTORMS IN SOUTHWESTERN NORTH DAKOTA WEDNESDAY
NIGHT AND OVER THE WESTERN HALF OF THE STATE ON THURSDAY. A BIT
WARMER THURSDAY WITH HIGHS 70-75.
THURSDAY NIGHT THROUGH MONDAY THE MODELS ARE IN FAIR AGREEMENT OVER
THE WESTERN AND CENTRAL US WITH AN UPPER LEVEL LOW CUTTING OFF FROM
THE LONGWAVE TROUGH AND REMAINING OVER THE 4-CORNERS AREA THROUGH
SUNDAY. THE MODELS BEGIN TO DIVERGE ON MONDAY WITH THE EUROPEAN
MODEL LIFTING THE CUTOFF LOW NORTHEASTWARD INTO THE CENTRAL
PLAINS...AND THE GFS MOVING THE CUTOFF LOW EASTWARD INTO THE
SOUTHERN PLAINS. THUS HAVE SMALL CHANCES OF THUNDERSTORMS THURSDAY
NIGHT THROUGH FRIDAY NIGHT...WITH INCREASING CHANCES SATURDAY.
CHANCES OF SHOWERS AND THUNDERSTORMS A BIT LOWER SUNDAY THROUGH
MONDAY WITH MORE UNCERTAINTY.
THE GOOD NEWS IS THAT TEMPERATURES SHOULD BE SEASONABLE TO SLIGHTLY
ABOVE AVERAGE WITH HIGHS IN THE 75-80 DEGREE RANGE FOR THE MEMORIAL
DAY WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 530 PM CDT MON MAY 19 2014
MVFR TO IFR/VLIFR CIGS HOVERING OVER FAR NORTHERN NORTH DAKOTA AND
INTO SOUTHERN SASKATCHEWAN AND MANITOBA MONDAY EVENING...WILL SLOWLY
MIGRATE SOUTH MONDAY NIGHT. EXPECT CIGS TO DETERIORATE TO VLIFR AT
KISN BY TUESDAY 08Z...WITH MVFR CIGS AT KMOT BY 09Z. MVFR CIGS WILL
SLIDE SOUTH TO KDIK BY 15Z TUESDAY...WITH CIGS REMAINING JUST ABOVE
VFR AT KBIS/KJMS DURING THE DAY TUESDAY. THE VLIFR CIGS AT KISN WILL
LIFT TO MVFR TUESDAY MORNING AND TO LOW VFR BY 21Z TUESDAY. KMOT
WILL REMAIN AT MVFR STATUS THROUGH THE DAY TUESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
LONG TERM...JV
AVIATION...KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1012 PM EDT TUE MAY 20 2014
.SYNOPSIS...
A WARM AND MOIST AIRMASS WILL REMAIN IN PLACE OVER THE REGION
TONIGHT. A COLD FRONT WILL PUSH THROUGH THE REGION TOMORROW AND
TOMORROW NIGHT...WITH DRIER AND SLIGHTLY COOLER AIR MOVING OVER
THE OHIO VALLEY FOR THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
CONVECTION ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA WILL
LIKELY CONTINUE THROUGH THE NIGHT AND MOVE EAST OR EAST
SOUTHEAST. THIS WILL PUT IT ALONG OR CLOSE TO THE FAR NORTHERN
COUNTIES IN THE FORECAST AREA. SO HAVE CONTINUED TO CONCENTRATE
HIGHER POPS THERE. THERE REMAINS SOME POTENTIAL FOR STRONGER
STORMS INTO WEST CENTRAL OHIO. HOWEVER INSTABILITY WILL DIMINISH A
BIT BY THE TIME STORMS REACH THAT AREA AND BASED ON RAP SOUNDINGS
THE STORMS MAY BE ELEVATED AT THAT POINT. BUT WILL CONTINUE TO
MONITOR THIS POTENTIAL. MEANWHILE THE SOUTHERN COUNTIES SHOULD
REMAIN DRY. FORECAST TEMPERATURES LOOK ON TRACK WITH LOWS IN THE
LOWER TO MID 60S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
LEFTOVER MORNING CONVECTION AND CLOUD DEBRIS WILL END UP PLAYING A
BIG ROLE IN THUNDERSTORM POTENTIAL FOR WEDNESDAY...WITH AN
OTHERWISE-FAVORABLE SETUP FOR STRONG STORMS.
THE WEAK SURFACE LOW WILL GRADUALLY DRIFT EAST ACROSS THE LOWER
PENINSULA OF MICHIGAN ON WEDNESDAY...WITH A COLD FRONT STRETCHING
TO THE SOUTHWEST INTO THE MIDDLE MISSISSIPPI VALLEY. THOUGH THE
FRONTAL BOUNDARY WILL NOT MAKE IT INTO THE ILN CWA UNTIL LATE
WEDNESDAY NIGHT...THE REGIME AHEAD OF THE FRONT WILL BE MOIST AND
UNSTABLE...AND THIS IS WHERE CONVECTION IS EXPECTED TO DEVELOP.
INSTABILITY WILL BE IMPACTED THE GREATEST BY REMNANTS FROM THE
EARLY WEDNESDAY MORNING ACTIVITY...A NEARLY-IMPOSSIBLE QUESTION
TO ANSWER UNTIL THE SITUATION TONIGHT PLAYS OUT. HOWEVER...THE
MOST LIKELY SCENARIO SEEMS TO FAVOR INSTABILITY GROWING THE MOST
IN THE SOUTHERN AND SOUTHWESTERN PORTIONS OF THE ILN CWA...WITH
THE GREATEST IMPEDING TO INSOLATION IN CENTRAL OHIO. HIGH-RES
MODELS ARE NOT KEYING IN ON MUCH STORM DEVELOPMENT IN THE NORTHERN
PORTIONS OF THE CWA...BUT SHOW A GOOD SIGNAL FOR DIURNALLY-TIMED
CONVECTION FIRING OFF IN THE SOUTHERN HALF OF THE FORECAST
AREA...IN AN AREA WHERE CAPE VALUES OF 2000-2500 J/KG APPEAR
POSSIBLE (AS LONG AS THE SUN CAN HEAT THINGS UP FOR A WHILE). WNW
WIND SHEAR IS COMFORTABLY IN THE MODERATE AREA OF THE
SCALE...WHICH WILL SUPPORT STORM ORGANIZATION. ALTHOUGH THERE IS
A LITTLE BIT OF TURNING (WSW AT THE SURFACE TO WNW AT
6KM)...OVERALL THIS SCENARIO SEEMS TO PRIMARILY SUPPORT A WIND AND
HAIL THREAT (PERHAPS WITH SOME DISCRETE AND ORGANIZED UPDRAFTS).
UNLESS CONVECTION COMPLETELY OVERTURNS THE ATMOSPHERE...A THREAT
FOR THUNDERSTORMS MAY CONTINUE INTO THE OVERNIGHT HOURS...WITH
SOME LINGERING INSTABILITY AHEAD OF THE COLD FRONT.
POPS WERE KEPT IN THE 20-30 PERCENT RANGE THROUGH MUCH OF THE DAY
ON WEDNESDAY...BUT RAMPED UP TO LIKELY IN THE SOUTHERN CWA DURING
THE AFTERNOON AND EVENING. POPS WERE DROPPED TO ZERO AFTER 09Z.
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY SLIDE
EASTWARD...BEGINNING TO INFLUENCE THE OHIO VALLEY ON THURSDAY. THE
AIR MASS MOVING IN WILL BE SIGNIFICANTLY DRIER AND SOMEWHAT
COOLER...WITH HIGHS DROPPING 5-10 DEGREES FROM WEDNESDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL ALLOW FOR DRY CONDITIONS THROUGH THE WEEKEND.
COOL NORTHERLY FLOW WILL KEEP TEMPERATURES IN THE UPPER 60S TO LOW
70S ON FRIDAY. A RIDGE WILL GRADUALLY WORK INTO THE REGION THROUGH
THE WEEKEND WITH TEMPERATURES WARMING EACH DAY. BY MONDAY HIGH
TEMPERATURES ARE EXPECTED TO BE IN THE 80S ACROSS THE ENTIRE FA.
PRECIPITATION LOOKS TO HOLD OFF UNTIL TUESDAY. THE GFS IS TRYING TO
DEVELOP A FEW THUNDERSTORMS ACROSS NW PORTIONS OF THE FA ON MONDAY
HOWEVER DECIDED TO GO WITH A DRY FORECAST ON MONDAY AT THIS TIME.
ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE DURING THE DAY
ON TUESDAY. ANY THUNDERSTORM ACTIVITY IS EXPECTED TO DISSIPATE
DURING THE EVENING HOURS WITH THE LOSS OF DAYTIME HEATING.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH MUCH OF THE NIGHT. THERE ARE
SOME INDICATIONS THAT MVFR CEILINGS COULD DEVELOP TOWARDS 12Z
ESPECIALLY AROUND KDAY. BUT HIGHER RESOLUTION GUIDANCE SUGGESTS
THAT VFR WILL CONTINUE. CONVECTION DEVELOPING IN NORTHERN ILLINOIS
THIS EVENING IS LIKELY TO CONTINUE THROUGH THE NIGHT AND MOVE EAST
SOUTHEAST. AT THIS POINT IT APPEARS THAT IT WILL HAVE WEAKENED AND
CONTINUE WEAKENING AS IT MOVES INTO THE REGION WITH LEFT OVER
SHOWERS AND STORMS AFFECTING ALL BUT THE CINCINNATI TERMINALS
BETWEEN 12Z AND 18Z. IT IS POSSIBLE THAT CEILINGS COULD DROP TO
MVFR WITH THIS DIMINISHING PRECIPITATION. BUT CONFIDENCE WAS TOO
LOW TO GO WITH THAT AS A PREVAILING CONDITION IN THE TAFS. APPEARS
THAT STORMS WILL REDEVELOP AFTER 20Z AND POTENTIALLY IMPACT THE
CINCINNATI TERMINALS LATE IN THE PERIOD.
OUTLOOK...THUNDERSTORMS POSSIBLE WEDNESDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...
SHORT TERM...HATZOS
LONG TERM...NOVAK
AVIATION...
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
753 PM EDT TUE MAY 20 2014
.SYNOPSIS...
WARM FRONT LIFTING NORTHEAST TONIGHT. WARMER AND MORE HUMID AIR WITH
ROUNDS OF CONVECTION INTO THURSDAY MORNING. COLD FRONT SAGS SOUTH
THURSDAY. DRIER FRIDAY INTO SUNDAY. WARM...HUMID MEMORIAL DAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
MADE SOME MINOR ADJUSTMENTS AND REFINEMENTS TO THE TIMING ON
PRECIPITATION PRIMARILY USING THE HRRR TIMING FOR THE EVENING AND
NAM TIMING FOR LATER TONIGHT AND TOMORROW. THINGS STILL LOOK GOOD
FOR THUNDERSTORM SET UP WEDNESDAY AFTERNOON/EVENING.
PREVIOUS DISCUSSION FOLLOWS...
NEAR 18Z...HAVE WARM FRONT CMH OHIO TO CRW WV
TO NR LNP VA. NICE DIFFERENCE IN CLOUD STRUGGLE ON EITHER SIDE OF
THE FRONT. MORE CELLULAR IN WARM SECTOR IN EASTERN KY.
WILL STILL TRY TO LEAVE SOUTHERN COUNTIES DRY TONIGHT...FIGURING MID
LEVEL CAPE WILL HOLD...DESPITE THE LATE AFTERNOON HEATING AND
INCREASING DEW POINTS.
RAP MODEL INDICATES SOME WEAK 500 MB VORT MAX MOVING ESE THROUGH
EASTERN OHIO INTO NORTH CENTRAL WV 03Z TO 05Z TONIGHT. SO NO BIG
CHANGES IN LEAVING SOME CHANCE POPS THERE TONIGHT. THOUGH...NOT
FIGURING ON STRONG CONVECTION. MAY BE A LULL IN NORTHERN COUNTIES
OVERNIGHT...BUT WITH WNW FLOW ALOFT...HELD ONTO CHANCE POPS FOR NOW.
STILL FIGURING ON A CONVECTION COMPLEX FORMING IN THE MIDWEST
TONIGHT AND RIDING ESE DURING THE 06Z TO 12Z TIME FRAME. WILL HOLD
ONTO INCREASING POPS IN OUR NORTHERN COUNTIES FOR A WEAKENING FORM
OF THAT COMPLEX POSSIBLY REACHING THOSE COUNTIES TOWARD DAWN. SLOWED
DOWN THAT INCREASE BY A FEW HOURS...BUT NEED TO HAVE COMPLEX FORM
BEFORE ANY MAJOR ADJUSTMENT ON TIMING AND HOW FAR SOUTH.
DURING WEDNESDAY...WHAT IS LEFT OF THAT MORNING COMPLEX AND ITS
DEBRIS CLOUDS COULD AFFECT TIMING THE NEW CONVECTION THAT DEVELOPS
ON WEDNESDAY. SO DID NOT WANT TO GET TOO FANCY AT THIS DISTANCE IN
TIME. OVERALL...WE ARE STILL GRADUALLY SHIFTING THE HIGHER POPS
SOUTH DURING THE LATE AFTERNOON. 700 MB MID LEVEL FLOW INCREASES TO
ABOUT 45 KNOTS. THINKING WIND WOULD BE THE HIGHER THREAT ASSOCIATED
WITH THE STRONGER THUNDERSTORMS.
TEMPERATURE WISE...WENT A SHADE COOLER TONIGHT IN THE SOUTH
TONIGHT...FIGURING ON LESS CLOUDS AND THE WIND SUBSIDING A BIT.
NO MAJOR CHANGE IN MAXIMUM TEMPS ON WEDNESDAY SINCE SO DEPENDENT ON
CONVECTION TIMING.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
CONVECTIVELY ACTIVE AT START OF PERIOD WITH COLD FRONT WELL
UPSTREAM...AND WARM ADVECTION SHEAR BENEATH NW FLOW ALOFT. CAPE
VALUES ARE FCST AS HIGH AS 3 KJ/KG OVER THE MID OHIO VALLEY ON DEW
POINTS INTO THE LOWER AND MID 60S...ALONG WITH PW VALUES UP TO 1.5
IN. 40 KT MID LEVEL FLOW SUGGESTS FAST MOVING STORMS SO FLOODING
SHOULD NOT AMOUNT TO MORE THAN BRIEF LOCALIZED HIGH WATER...LEAVING
WIND DAMAGE AS THE MAIN THREAT. FLOW REGIME COULD ALSO SUPPORT AN
ORGANIZED CONVECTIVE COMPLEX MOVING E-SE.
ACTIVITY COULD LAST INTO THE NT AS SOME INSTABILITY IS MAINTAINED
AHEAD OF THE COLD FRONT ADVANCING FROM THE NW...WITH DRIER AIR
INFILTRATING THE AREA LATE WED NT AND THU. COULD THEREFORE STILL
SEE THUNDERSTORMS SRN ZONES THU BUT THE SEVERE THREAT SHOULD BE
DIMINISHED.
HIGH PRESSURE SETTLES IN BENEATH NW FLOW ALOFT THU NT AND FRI.
NO MAJOR TEMPERATURES...WITH MET AND / OR GFS BASED MOS BLENDED IN
IN MOST CASES. INHERITED PACKAGE SHOWED MORE OF A BAROCLINIC ZONE
THAN MOS GUIDANCE SUGGESTS BUT PRESERVED GIVEN MODEL GUIDANCE AS
THIS IS STILL SUGGESTED IN THE MODEL LOW LEVEL THERMAL FIELDS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE RULES AT THE SFC THIS PERIOD WHILE UPPER LEVEL NW FLOW
GIVES WAY TO RIDGING. EXPECT A STRETCH OF DRY WEATHER WITH
MODERATING TEMPERATURES THROUGH THE MEMORIAL DAY WEEKEND. DIURNAL
THUNDERSTORMS START TO BECOME A FACTOR MON OR TUE...HAVE A SLIGHT
CHANCE FOR AFTERNOON THUNDERSTORMS IN THE MOUNTAINS MON
AFTERNOON...AND THEN A CHC EVERYWHERE TUE AFTERNOON.
INHERITED TEMPERATURES LOOKED GOOD...WITH MEX AND / OR WPC BLENDED
IN HERE AND THERE...ALONG WITH CONSENSUS ALL AT THE END. SOME OF
THE GUIDANCE WAS LOWER BUT DID NOT SEE FIT TO LOWER MUCH IN THIS
PATTERN.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
POSSIBLE ISOLATED SHOWERS AND THUNDERSTORM IN EASTERN OHIO INTO
NORTHERN WEST VIRGINIA INCLUDING THE UNI-PKB-CKB CORRIDOR THROUGH
06Z. CONVECTION WEAKENING OVERNIGHT WITH COMPLEX REACHING EASTERN
OHIO INTO NORTHERN WEST VIRGINIA TOWARD 12Z WEDNESDAY. NEW
CONVECTION FORMING DURING THE DAY WEDNESDAY AND TRENDING SOUTH
INTO THE HTS-CRW-BKW CORRIDOR BY 21Z WEDNESDAY TO 00Z THURSDAY.
MAINLY VFR TONIGHT WITH LOWER CONDITIONS IN CONVECTION ON
WEDNESDAY BUT MOSTLY AFTER 18Z...WITH CEILINGS BECOMING 2000 TO
3000 FT BKN/OVC AND VSBY DOWN 1 TO 3 MILES DURING STORMS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING ON CONVECTIVE COMPLEX MOVING INTO THE
AREA WEDNESDAY MORNING COULD VARY A BIT AS COULD THE TIMING ON THE
DISTURBANCE PUSHING SOUTH THROUGH THE AREA AFTER IT.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE WED 05/21/14
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H M M M H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H M
AFTER 00Z THURSDAY...
IFR CONDITIONS IN CONVECTION COMPLEXES THROUGH MUCH OF WEDNESDAY
NIGHT...THEN LINGERING IFR IN LOW CLOUDS AND LIGHTER SHOWERS NEAR THE COLD
FRONT 12Z TO 18Z THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/TRM
NEAR TERM...KTB/JR
SHORT TERM...TRM
LONG TERM...TRM
AVIATION...KTB/JR
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
150 AM EDT MON MAY 19 2014
.SYNOPSIS...
HIGH PRESSURE SETTLES IN TONIGHT. WARM FRONT TUESDAY. UNSETTLED
MID WEEK WITH A COLD FRONT SAGGING IN LATE WEDNESDAY INTO
THURSDAY. ANOTHER BROAD HIGH PRESSURE NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
1030 PM UPDATE...
NO CHANGES ATTM.
630 PM UPDATE...
BASED ON NEW MODEL GUIDANCE AND OBSERVED OVERNIGHT LOWS LAST
NIGHT...ELECTED TO UPGRADE RANDOLPH/POCAHONTAS TO A FREEZE
WARNING. LATEST MAV GUIDANCE AND LAMP TAKE EKN DOWN INTO THE UPPER
20S WHICH WOULD CORRELATE A BIT LOWER IN COLD SPOTS OF E RANDOLPH
COUNTY...IE GLADY. HIGHER RIDGETOPS MAY NOT GET QUITE AS COLD AS
LAST NIGHT WITH SOME RECOVERY IN H85 TEMPS VS LAST NIGHT BUT STILL
BELIEVE A COUNTY WIDE AVG CAN BE ACHIEVED. NO OTHER CHANGES TO
HEADLINES AT THIS TIME. STILL EXPECT PATCHY FROST IN AREAS NOT IN
FROST ADVISORY...IE TRI STATE REGION.
PREVIOUS DISCUSSION BELOW...
TRANQUIL WX IN THE NEAR-TERM PERIOD CHARACTERIZED BY SFC HIGH
PRESSURE AND AMPLIFYING NW FLOW ALOFT.
TONIGHT...SFC HIGH PRESSURE BUILDS IN FROM THE NORTH AND IS
ESSENTIALLY CENTERED OVER THE NORTH AND NORTHEAST ZONES BY 09Z-12Z
MON WITH MOSTLY CLEAR SKIES AND NEAR-CALM WINDS OVERNIGHT. STILL
SOME UNCERTAINTY REGARDING OVERNIGHT MINS AND ANY SUBSEQUENT FROST
HIGHLIGHTS...MAINLY WITH REGARD TO OVERNIGHT DEWPOINTS. VARIOUS NEAR
AND SHORT TERM NWP WIDE APART ON OVERNIGHT DEWPOINTS...WHICH LIKELY
STEM FROM EXACTLY HOW LOW DEWPTS DROP TODAY WITH MIXING. AT
15Z...HSP CURRENTLY REPORTING A 28F TD. LATEST RUC13 AND HRRR
OUTPUT...AMONG OTHERS...SUGGEST DEWPOINTS WAY DOWN IN THE MID 20S
LOWLANDS THIS AFTERNOON...AND CONTINUING ALL NIGHT.
MEANWHILE...LATEST LAMP GUIDANCE KEEPS DEWPTS IN THE UPPER 30S.
NON-CONVECTIVE NWP RUN THE GAMUT IN BETWEEN...KEEPING DEWPOINTS
GENERALLY LOW/MID 30S...AND SOME A BIT HIGHER THAN THAT. PLAN ON
WATCHING AFTERNOON DEWPOINTS BEFORE MAKING A FINAL CALL ON COVERAGE
OF TONIGHT/S FROST ADVISORY...BUT RIGHT NOW ANTICIPATE PROBABLY
REMAINING CLOSE TO SOME FORM OF CONSMOS WHICH IS MORE CONSISTENT
ACROSS THE BOARD AT THIS POINT WITH TD/S RECOVERING INTO THE
MID 30S FOR THE LOWLANDS...AFTER AFTERNOON TD/S THIS AFTERNOON
MIX DOWN INTO THE LOW 30S. FROST DOES APPEAR MORE LIKELY TONIGHT
VERSUS LAST NIGHT...AND DO ANTICIPATE A FROST ADVISORY NEEDED FOR AT
LEAST SOME OF THE EASTERN MOUNTAINS COUNTIES.
MONDAY...VERY NICE AND PLEASANT DAY IS IN STORE FOR THE AREA UNDER
MOSTLY SUNNY TO PERHAPS SOME PARTLY CLOUDY SKIES...ALONG WITH WARMER
TEMPERATURES AND CONTINUED LIGHT WINDS. LATEST NAM12 IS HINTING AT
THE POSSIBILITY OF SOME LIGHT CONVECTIVE SHOWERS ALONG THE HIGHEST
RIDGES OF POCAHONTAS COUNTY AREA...BUT THE CONVERGENCE APPEARS VERY
WEAK AND WILL TREAT THIS WITH ONLY A SLIGHT RAISE OF SILENT POPS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
MODELS ARE IN AGREEMENT WITH HIGH PRESSURE EXITING THE EASTERN
MOUNTAINS BY MONDAY NIGHT. AT THE SAME TIME...WIND TURNS FROM THE
SOUTHWEST...AHEAD OF THE NEXT FRONTAL SYSTEM...TO BRING AN INCREASE
LOW LEVEL MOISTURE...SOME CLOUDS FROM WEST TO EAST. A MID LEVEL
SHORTWAVE WILL PASS ACROSS OUR NORTH TUESDAY...WHILE A WARM FRONT
LIFTS NORTH NORTHEAST ACROSS THE AREA. THESE FEATURES WILL INTERACT
TO BRING CHANCE FOR PCPN MAINLY ACROSS THE NORTHERN THIRD OF THE
AREA.
ADDITIONAL MID LEVEL SHORTWAVES ARE SUGGESTED BY MODELS TO MOVE EAST
UNDER ALMOST ZONAL FLOW BY MID WEEK. WITH THE INCREASE IN LOW LEVEL
MOISTURE...SOME FORCING FROM THE SHORTWAVES AND BEING IN THE WARM
SECTOR...KEPT HIGH CHANCE POPS MAINLY ACROSS THE NORTHERN SECTIONS
WEDNESDAY. IF FACT...IT COULD BE QUITE UNSTABLE ON WEDNESDAY WITH
SFC BASED CAPE EXCEEDING 1500 J/KG...DEEP LAYERED SHEAR UP TO 40
KNOTS MAINLY NORTH...AND PRECIPITABLE WATER AROUND 1.5 INCHES.
THE COLD FRONT WILL REACH SOUTHEAST OH...WITH WIDESPREAD SHOWERS AND
THUNDERSTORMS BY LATE WEDNESDAY NIGHT INTO EARLY THURSDAY...THEN
SPREAD NORTHWEST TO SOUTHEAST LATER THURSDAY WITH GOOD CHANCE FOR
SHOWERS AND THUNDERSTORMS. KEPT LIKELY POPS AS SUGGESTED BY THE SREF
WITH SUPPORT FROM THE GFS AND ECMWF.
THE SOUTHWEST FLOW AND ASSOCIATED WARMER AIRMASS WILL BRING A
WARMING TREND THROUGH THE PERIOD. TEMPERATURES EXPECTED TO REACH
NEAR 80 DEGREES TUESDAY...ESPECIALLY SOUTH AND WEST WITH MORE
SUNSHINE. EVEN WARMER A AFTERNOON CAN BE EXPECTED WEDNESDAY AHEAD OF
THE COLD FRONT UNDER WARM ADVECTION.
USED A BLEND OF HPC GUIDANCE AND ALL BLEND MOS GUIDANCE THROUGH THE
PERIODS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
BY THURSDAY THE COLD FRONT WILL BE EXITING THE EASTERN
MOUNTAINS...ALLOWING DRY AND FRESHER AIR TO SET IN FROM THE WEST. A
SFC HIGH PRESSURE DEVELOPS ACROSS THE GREAT LAKES...OH VALLEY INTO
WV THROUGH THE WEEKEND WITH NEAR CALM FLOW.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
06Z MONDAY THRU 06Z TUESDAY...
HIGH PRESSURE SHIFTS EAST TODAY WITH A WARM FRONT APPROACHING FROM
THE WEST TONIGHT. LIFR RIVER AND VALLEY FOG 09Z TO 13Z...AFFECTING
MAJOR TERMINALS EXCEPT BKW. OTHERWISE...VFR MOSTLY CLEAR...WITH SOME
MID TO HIGH CLOUDS INCREASING FROM THE WEST AFTER 03Z TUESDAY. WINDS
LIGHT AND VARIABLE THRU THE PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: FOG TIMING AND COVERAGE TONIGHT MAY VARY SLIGHTLY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 05/19/14
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H H M L L L H H H H H
HTS CONSISTENCY H H M L L L L M H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H M L L L H H H H H
PKB CONSISTENCY H H M L L L L M H H H H
CKB CONSISTENCY H H H H M M M H H H H H
AFTER 06Z TUESDAY...
NO WIDESPREAD IFR CONDITIONS EXPECTED AT THIS TIME.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR WVZ006>011-
013>020-024>040.
FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR WVZ046-047.
OH...FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR OHZ066-067-075-
076-085-086.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...50/30
SHORT TERM...ARJ
LONG TERM...ARJ
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS MEDFORD OR
232 PM PDT MON MAY 19 2014
.SHORT TERM...THE WEATHER PATTERN HAS BECOME ACTIVE ACROSS MOST OF
THE FORECAST AREA FOR THE FIRST TIME IN MORE THAN A
WEEK...COURTESY OF AN UPPER LEVEL LOW THAT IS SWINGING INTO
NORTHERN CALIFORNIA FROM THE OFFSHORE WATERS. THUNDERSTORM
ACTIVITY HAS BEEN FOCUSED OVER SOUTHERN LAKE...KLAMATH...AND MODOC
COUNTIES TODAY SO FAR...BUT STORMS ARE FORMING OVER SISKIYOU AND
KLAMATH COUNTIES NOW AND WILL LIKELY IMPACT JACKSON AND JOSEPHINE
COUNTIES LATER THIS AFTERNOON.
THE MAIN THREATS WITH THESE STORMS ARE LIGHTNING...SMALL
HAIL...GUSTY WINDS...AND BRIEF HEAVY RAIN. CURRENT MODEL DATA FROM
THE RAP13 AND HRRR 3KM SUGGESTS THUNDERSTORMS WILL FORM OVER THE
SISKIYOUS AND CASCADES AROUND 3PM AND THEN PUSH INTO THE ROGUE
VALLEY AROUND 4 TO 5 PM. OF COURSE WE CAN`T TAKE THESE MODELS
VERBATIM...BUT THIS PROVIDES A GOOD IDEA OF THE SPATIAL EVOLUTION
AND MOVEMENT OF THESE STORMS.
TONIGHT...SHOWER AND THUNDERSTORMS SHOULD DIMINISH WEST OF THE
CASCADES AND THEY WILL BE FOCUSED OVER EASTERN SISKIYOU COUNTY AND
SOUTHERN LAKE AND KLAMATH COUNTIES AS THE UPPER LOW SHIFTS TO THE
SOUTH AND EAST. HERE...A DEFORMATION ZONE TO THE NORTHEAST OF THE
LOW COULD SUSTAIN SHOWER ACTIVITY FOR MUCH OF THE NIGHT. THE LOW
WILL BE SLOW ENOUGH TO MOVE OUT THAT SHOWERS COULD AFFECT EASTERN
SISKIYOU AND MODOC COUNTIES ON TUESDAY...WITH THUNDERSTORMS
POSSIBLE IN THE AFTERNOON.
AREAS AWAY FROM MODOC AND EASTERN SISKIYOU COUNTY WILL EXPERIENCE
A WARMING AND DRYING TREND FROM TUESDAY THROUGH THURSDAY THAT WILL
BRING TEMPERATURES UP TO ABOUT 10 DEGREES ABOVE NORMAL BY
THURSDAY. THE CURRY COUNTY COAST IN PARTICULAR WILL SEE WELL ABOVE
NORMAL TEMPERATURES BY WEDNESDAY DUE TO MODERATE OFFSHORE EAST TO
NORTHEAST WINDS.
.LONG TERM...FRIDAY THROUGH MONDAY...THE OPERATIONAL EC AND GFS
ARE IN SIMILAR AGREEMENT ON FRIDAY, THEN THEY BEGIN TO DIVERGE
FOR THE UPCOMING HOLIDAY WEEKEND. THE EC SHOWS AN UPPER RIDGE
BUILDING NEAR 130W SATURDAY, THEN THE RIDGE AXIS BUILDS INTO THE
PAC NW SUNDAY IN RESPONSE TO AN UPPER TROUGH DIGGING OUT NEAR
140W. THE RIDGE BREAKS DOWN ON MONDAY AS THE ABOVE MENTION UPPER
TROUGH PUSHES EAST AND WEAKENS AT THE SAME TIME. IN CONTRAST...THE
GFS SHOWS A WEST TO SOUTHWEST FLOW WITH A STRONGER UPPER LOW IN
THE GULF OF ALASKA ON SATURDAY...TRACKING IT TOWARDS VANCOUVER
ISLAND BY SUNDAY EVENING THEN MOVING SOUTH INTO OREGON/WASHINGTON
MEMORIAL DAY. OF NOTE, THE PREVIOUS GFS RUN WAS SIMILAR TO THE EC
AND THE RMOP GUIDANCE FOR NEXT WEEKEND SHOWS A LOW PROBABILITY AND
PREDICTABILITY OF THE STRONGER TROUGH. THEREFORE CONFIDENCE IN THE
GFS SOLUTION IS LOW AND WE`LL BE LEANING TOWARDS THE EC SOLUTION,
THUS KEPT POPS LOW IN THE EXTENDED. TEMPERATURES WILL BE MILDER
BUT WERE NOT EXPECTING ANY HEAT WAVE. MOST LIKELY THEY WILL BE
NEAR OR SLIGHTLY ABOVE NORMAL. -PETRUCELLI
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING
WITH A COOL UNSTABLE ATMOSPHERE OVERHEAD. BRIEF MVFR CIGS ARE
POSSIBLE IN HEAVIER SHOWERS AND ISOLATED THUNDERSTORMS MAINLY
BETWEEN 22 AND 03Z WHICH COULD OBSCURE THE HIGHER TERRAIN. IN
ADDITION SMALL HAIL IS ALSO POSSIBLE DURING THIS TIME. AREAS OF
MVFR CIGS WILL RETURN TO THE COAST THIS EVENING AND SPREAD INTO
THE UMPQUA BASIN TONIGHT. -PETRUCELLI
&&
.MARINE...UPDATED 19/1430 PDT...LOW PRESSURE WILL CONTINUE TO TRACK
SOUTH OVER THE COASTAL WATERS THIS EVENING AND TONIGHT. AS THE
SYSTEM MOVES OVER THE COASTAL WATERS...EXPECT SHOWERS WITH LOCALLY
GUSTY WINDS AND CHOPPY SEAS. A THERMAL TROUGH AND OFFSHORE HIGH
PRESSURE WILL DEVELOP TUESDAY...RESULTING IN MODERATE TO STRONG
NORTH WINDS AND STEEP WIND-DRIVEN SEAS TUESDAY AND WEDNESDAY OVER
THE COASTAL WATERS. MODELS AND PRESSURE GRADIENT FORECASTS HAVE
CONSISTENTLY SUGGESTED GALE FORCE WINDS AND STEEP HAZARDOUS SEAS IN
WATERS SOUTH OF GOLD BEACH. HAVE ISSUED A GALE WATCH AND HAZARDOUS
SEAS WATCH FOR THIS AREA. ALL OTHER AREAS CAN EXPECT STRONG SMALL
CRAFT WINDS AND SEAS THROUGH THURSDAY. AT THAT TIME...WINDS AND SEAS
WILL DIMINISH AS THE THERMAL TROUGH WEAKENS. AFTER A RELATIVELY
QUIET WEEKEND...A WEAK FRONT IS EXPECTED TO APPROACH THE WATERS
EARLY NEXT WEEK. -BPN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...GALE WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY EVENING FOR
PZZ356-376.
SMALL CRAFT ADVISORY FOR WINDS FROM 5 AM TUESDAY TO 11 PM PDT
WEDNESDAY FOR PZZ350-356-370.
HAZARDOUS SEAS WATCH FROM TUESDAY AFTERNOON THROUGH LATE
WEDNESDAY NIGHT FOR PZZ356-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 5 AM TUESDAY TO 8
AM PDT FRIDAY FOR PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR WINDS FROM 5 AM TUESDAY TO 11 PM PDT
THURSDAY FOR PZZ376.
$$
NSK/MAP/MAP
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1201 AM EDT WED MAY 21 2014
.SYNOPSIS...
A WARM FRONT WILL SLIDE FROM THE OHIO VALLEY INTO CENTRAL
PENNSYLVANIA TONIGHT AND WEDNESDAY. A COLD FRONT WILL THEN MOVE
THROUGH ON THURSDAY...BRINGING COOLER AIR BACK TO THE REGION. THE
EXTENDED FORECAST INDICATES A GRADUAL WARMING TREND BEGINNING THIS
WEEKEND DESPITE SOME SHOWERS LINGERING IN THE POST- FRONTAL
NORTHWEST FLOW.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE BACK EDGE OF THE CONVECTION SEEMS TO BE ON THE LAKE ERIE
SHORE-LINE NOW...MAKING A BEE-LINE FOR NW PA WITH STILL AN
OCCASIONAL LIGHTNING STRIKE STILL BEING DISPLAYED.
HOWEVER THE 23Z HRRR KEEPS THIS ZONE ACTIVE INTO THE OVERNIGHT AS
THE WARM FRONT PROGRESSES SLOWLY EAST. I RAMPED UP THE POPS AND
EXPANDED THE COVERAGE AS EARLIER MODEL OUTPUT REALLY DOWNPLAYED
THE AREAL COVERAGE OF THE SHOWERS. NEW MESO MODELS SEEM TO BE
FINALLY CATCHING UP.
WITH CLOUDS IN PLACE AND WEAK SOUTHERLY FLOW...A MILD NIGHT IN
STORE WITH TEMPS ONLY FALLING INTO THE 50S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
SHORTWAVE SLIDES SE OVER THE WARM FRONT ON WED...BRINGING SOME
BETTER DYNAMICS TO CENTRAL PA. BEST INSTABILITY/LIFT REMAINS OFF
TO OUR WEST THOUGH...AND PRIMARY THREAT OF SVR WEATHER WILL
REMAIN CONFINED TO THOSE REGIONS...BUT SOME STRONGER TSTORMS MAY
SLIP EASTWARD TOWARD OUR WESTERN BORDER LATER WED AS WARM SECTOR
WORKS NE AND MID LEVEL WINDS APPROACH 50 KTS. OVERALL
THOUGH...EXPECTING A SHOWERY DAY WITH SCT TSTORMS.
COLD FRONT FOLLOWS WED NIGHT/EARLY THU...WITH ANOTHER ROUND OF SCT
SHOWERS. THE UPPER LOW DRIVING THIS WHOLE CONVOLUTED SYSTEM WILL
THEN RESIDE OVER NEW ENGLAND FOR A DAY OR SO. THIS WILL KEEP THE
WX COOLER AND UNSETTLED FOR THE REST OF THE WEEK.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
RIDGE-TOPPING SHORTWAVE TROUGH IS EXPECTED TO AMPLIFY/DIG SEWD FROM
THE UPPER GREAT LAKES REGION ACROSS THE NORTHERN MID-ATLC AND
INTERIOR NORTHEAST STATES D3-4. THE UPPER LOW EXITING NORTHERN NEW
ENGLAND WILL ANCHOR A MEAN TROUGH ALONG/OFFSHORE THE EAST COAST SAT-
SUN BEFORE BEING REPLACED BY A GRADUALLY BUILDING HIGH-LEVEL RIDGE
D6-8.
THE 20/00Z AND 20/12Z MODEL AND ENSEMBLE CYCLES CONTINUE TO HANDLE
THE 500MB HEIGHT PATTEN ACROSS THE CONUS REASONABLY WELL THROUGH THE
UPCOMING WEEKEND. THE BULK OF THE UNCERTAINTY IN THE MID-UPPER
LEVEL FLOW AFTER DAY 6 RESIDES OVER THE WESTERN 1/3 OF NOAM.
SENSIBLE WEATHER HIGHLIGHTS...SCT SHWRS W/ISOLD TSTMS SHOULD
ACCOMPANY SFC COLD FRONT THRU CNTRL/RN PA EARLY THURS. THE FRONTAL
PASSAGE WILL BRIEFLY RETURN THE RECENT COOL/DRY CYC FLOW PATTERN
ALOFT WITH DIURNAL/INSTABILITY SHOWERS ASSOCD WITH INDIVIDUAL
SHORTWAVE IMPULSES ROTATING AROUND THE BACKSIDE OF THE DEPARTING
UPPER LEVEL TROUGH. A MID-LEVEL ANTICYCLONE BUILDING NORTH/EAST FROM
THE LWR MS VLY WILL PRODUCE A MORE TYPICAL EARLY-SUMMER PATTERN WITH
STRONG SIGNALS FOR AN UPWARD TREND IN TEMPERATURE/HUMIDITY FROM
MEMORIAL DAY INTO THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
SHOWERS CONTINUE TO TO INCREASE AS THEY ARE STREAMING ACROSS THE
NORTH EASTERN HALF OF PENNSYLVANIA THIS EVENING. THIS HAS ALLOWED
FOR BRIEF IFR CONDITIONS AT BFD...AND POSSIBLE MVFR AT IPT. THESE
SHOWERS ARE LIGHT IN GENERAL...BUT EMBEDDED HEAVY SHOWERS COULD
ALLOW FOR BRIEF MVFR TO IFR CIGS AND VSBYS AS THE SYSTEM MOVES IN
OVERNIGHT. THE SHOWERS HAVE ALSO ALLOWED FOR THE SFC TO BE MIXED
AND CAUSED GUSTY WINDS AT UNV. THESE WINDS WILL SUBSIDE BETWEEN 06
TO 08Z AS THE SFC DECOUPLES.
SHOWER ACTIVITY WILL PICK UP AS THE NIGHT PROGRESSES AND THROUGH TOMORROW
AS A WARM FRONT MOVES ACROSS THE REGION. THIS WILL BE QUICKLY FOLLOWED
BY A COLD FRONT ON THURSDAY. SCT THUNDERSTORMS WILL ALSO IMPACT
CENTRAL PA...MAINLY DURING THE DAY TOMORROW...WITH A FEW STRONG
STORMS POSS ACROSS THE NORTH AND WEST LATER WED INTO WED EVE.
LOWERING CIGS WILL SLIDE IN FROM THE NORTHWEST LATE TONIGHT AND
MAY BRING RESTRICTIONS INTO THE CENTRAL MTNS FOR MUCH OF WED. THE
SE SHOULD REMAIN MAINLY VFR...EXCEPT FOR LOCALIZED TSTORM IMPACTS.
.OUTLOOK...
WED...AM FOG/LOW CIGS LIKELY NORTHERN/CENTRAL MTNS. SCT MAINLY PM
TSRA IMPACTS POSS.
THU...EARLY AM FOG/LOW CIGS POSS...MAINLY W MTNS.
FRI-SAT...MAINLY VFR. SCT SHOWERS POSS MAINLY N AND W WITH LOCAL
RESTRICTIONS.
SUN...NO RESTRICTIONS EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...RXR
LONG TERM...STEINBUGL
AVIATION...CERU/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1023 PM EDT TUE MAY 20 2014
.SYNOPSIS...
A WARM FRONT WILL SLIDE FROM THE OHIO VALLEY INTO CENTRAL
PENNSYLVANIA TONIGHT AND WEDNESDAY. A COLD FRONT WILL THEN MOVE
THROUGH ON THURSDAY...BRINGING COOLER AIR BACK TO THE REGION. THE
EXTENDED FORECAST INDICATES A GRADUAL WARMING TREND BEGINNING THIS
WEEKEND DESPITE SOME SHOWERS LINGERING IN THE POST- FRONTAL
NORTHWEST FLOW.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE BACK EDGE OF THE CONVECTION SEEMS TO BE ON THE LAKE ERIE
SHORE-LINE NOW...MAKING A BEE-LINE FOR NW PA WITH STILL AN
OCCASIONAL LIGHTNING STRIKE STILL BEING DISPLAYED.
HOWEVER THE 23Z HRRR KEEPS THIS ZONE ACTIVE INTO THE OVERNIGHT AS
THE WARM FRONT PROGRESSES SLOWLY EAST. I RAMPED UP THE POPS AND
EXPANDED THE COVERAGE AS EARLIER MODEL OUTPUT REALLY DOWNPLAYED
THE AREAL COVERAGE OF THE SHOWERS. NEW MESO MODELS SEEM TO BE
FINALLY CATCHING UP.
WITH CLOUDS IN PLACE AND WEAK SOUTHERLY FLOW...A MILD NIGHT IN
STORE WITH TEMPS ONLY FALLING INTO THE 50S.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
SHORTWAVE SLIDES SE OVER THE WARM FRONT ON WED...BRINGING SOME
BETTER DYNAMICS TO CENTRAL PA. BEST INSTABILITY/LIFT REMAINS OFF
TO OUR WEST THOUGH...AND PRIMARY THREAT OF SVR WEATHER WILL
REMAIN CONFINED TO THOSE REGIONS...BUT SOME STRONGER TSTORMS MAY
SLIP EASTWARD TOWARD OUR WESTERN BORDER LATER WED AS WARM SECTOR
WORKS NE AND MID LEVEL WINDS APPROACH 50 KTS. OVERALL
THOUGH...EXPECTING A SHOWERY DAY WITH SCT TSTORMS.
COLD FRONT FOLLOWS WED NIGHT/EARLY THU...WITH ANOTHER ROUND OF SCT
SHOWERS. THE UPPER LOW DRIVING THIS WHOLE CONVOLUTED SYSTEM WILL
THEN RESIDE OVER NEW ENGLAND FOR A DAY OR SO. THIS WILL KEEP THE
WX COOLER AND UNSETTLED FOR THE REST OF THE WEEK.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
RIDGE-TOPPING SHORTWAVE TROUGH IS EXPECTED TO AMPLIFY/DIG SEWD FROM
THE UPPER GREAT LAKES REGION ACROSS THE NORTHERN MID-ATLC AND
INTERIOR NORTHEAST STATES D3-4. THE UPPER LOW EXITING NORTHERN NEW
ENGLAND WILL ANCHOR A MEAN TROUGH ALONG/OFFSHORE THE EAST COAST SAT-
SUN BEFORE BEING REPLACED BY A GRADUALLY BUILDING HIGH-LEVEL RIDGE
D6-8.
THE 20/00Z AND 20/12Z MODEL AND ENSEMBLE CYCLES CONTINUE TO HANDLE
THE 500MB HEIGHT PATTEN ACROSS THE CONUS REASONABLY WELL THROUGH THE
UPCOMING WEEKEND. THE BULK OF THE UNCERTAINTY IN THE MID-UPPER
LEVEL FLOW AFTER DAY 6 RESIDES OVER THE WESTERN 1/3 OF NOAM.
SENSIBLE WEATHER HIGHLIGHTS...SCT SHWRS W/ISOLD TSTMS SHOULD
ACCOMPANY SFC COLD FRONT THRU CNTRL/RN PA EARLY THURS. THE FRONTAL
PASSAGE WILL BRIEFLY RETURN THE RECENT COOL/DRY CYC FLOW PATTERN
ALOFT WITH DIURNAL/INSTABILITY SHOWERS ASSOCD WITH INDIVIDUAL
SHORTWAVE IMPULSES ROTATING AROUND THE BACKSIDE OF THE DEPARTING
UPPER LEVEL TROUGH. A MID-LEVEL ANTICYCLONE BUILDING NORTH/EAST FROM
THE LWR MS VLY WILL PRODUCE A MORE TYPICAL EARLY-SUMMER PATTERN WITH
STRONG SIGNALS FOR AN UPWARD TREND IN TEMPERATURE/HUMIDITY FROM
MEMORIAL DAY INTO THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
SHOWERS CONTINUE TO TO INCREASE AS THEY ARE STREAMING ACROSS THE
NORTH EASTERN HALF OF PENNSYLVANIA THIS EVENING. THIS HAS ALLOWED
FOR BRIEF IFR CONDITIONS AT BFD...AND POSSIBLE MVFR AT IPT. THESE
SHOWERS ARE LIGHT IN GENERAL...BUT EMBEDDED HEAVY SHOWERS COULD
ALLOW FOR BRIEF MVFR TO IFR CIGS AND VSBYS...MAINLY AFFECTING JST
AND BFD. AS THE SYSTEM MOVES IN OVERNIGHT.
WEAK SPOTTY SHOWERS ARE MOVING THROUGH THE LAURELS AND THE
ADJACENT VALLEYS. HOWEVER THESE ARE NOT CAUSING ANY RESTRICTIONS.
SHOWER ACTIVITY WILL PICK UP AS THE NIGHT PROGRESSES AND DEFINITELY
ON TOMORROW AS A WARM FRONT MOVES ACROSS THE REGION...FOLLOWED BY
A COLD FRONT ON THURSDAY. SCT THUNDERSTORMS WILL ALSO IMPACT
CENTRAL PA...MAINLY DURING THE DAY TOMORROW...WITH A FEW
STRONG STORMS POSS ACROSS THE NORTH AND WEST LATER WED INTO WED
EVE. LOWERING CIGS WILL SLIDE IN FROM THE NORTHWEST LATE TONIGHT
AND MAY BRING RESTRICTIONS INTO THE CENTRAL MTNS FOR MUCH OF WED.
THE SE SHOULD REMAIN MAINLY VFR...EXCEPT FOR LOCALIZED TSTORM
IMPACTS.
.OUTLOOK...
WED...AM FOG/LOW CIGS LIKELY NORTHERN/CENTRAL MTNS. SCT MAINLY PM
TSRA IMPACTS POSS.
THU...EARLY AM FOG/LOW CIGS POSS...MAINLY W MTNS.
FRI-SAT...MAINLY VFR. SCT SHOWERS POSS MAINLY N AND W WITH LOCAL
RESTRICTIONS.
SUN...NO RESTRICTIONS EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...RXR
LONG TERM...STEINBUGL
AVIATION...CERU/RXR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
340 AM EDT MON MAY 19 2014
.SYNOPSIS...
HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION TODAY AND PERSIST
INTO TUESDAY BRINGING MUCH WARMER TEMPERATURES BY MID WEEK. A BACK
DOOR COLD FRONT SLOWLY MOVES THROUGH THE REGION THURSDAY AND FRIDAY
WITH A LOW RAIN CHANCES AND COOLER TEMPERATURES BY THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM...LATEST SATELLITE IMAGES AND SFC OBSERVATIONS INDICATE
THAT AREAS OF FOG HAS DEVELOPED ACROSS WESTERN NC...NE GA...AND
PORTIONS OF THE UPSTATE ALONG AND WEST OF I-26. THIS IS THE SAME
AREA THAT RECEIVED MEASURABLE RAIN SUN MORNING. LATEST MOS AND
NAM/HRRR CONDENSATION PRESSURE DEFICITS INDICATE THAT FOG WILL
REMAIN AND WILL LIKELY THICKEN THROUGH SUNRISE. I WILL HIGHLIGHT THE
POTENTIAL FOR THICK FOG WITH A DENSE FOG ADVISORY THROUGH 10 AM.
TODAY...LOW LEVEL WINDS WILL VEER THROUGH THE DAYLIGHT HOURS AS SFC
HIGH PRESSURE SETTLES OVER THE MID ATLANTIC COAST. AT H5...A RIDGE
IS EXPECTED TO AMPLIFY ACROSS THE CENTRAL CONUS AS A TROUGH AXIS
REMAINS OVER THE WESTERN ATLANTIC. THIS PATTERN SHOULD RESULT IN MID
TO HIGH LEVEL NW FLOW ACROSS THE SOUTHERN APPALACHIANS. FORECAST
SOUNDINGS INDICATES THAT MTN WAVE CIRRUS WILL DEVELOP ACROSS THE
EASTERN SLOPES EAST TO THE PIEDMONT THIS AFTERNOON THROUGH THE EARLY
EVENING. IN ADDITION...A FEW CAMS INDICATE THAT BRIEF SHRA WILL
DEVELOP OVER THE HIGHEST RIDGES DURING THE HEAT OF THE AFTERNOON. I
WILL FEATURE INCREASED CLOUD COVER AND SCHC RIDGE POPS WITH THIS
FORECAST PACKAGE. HIGH TEMPERATURES ARE FORECAST TO RANGE FROM NEAR
70 WITHIN THE MTN VALLEYS TO MID TO UPPER 70S EAST OF THE MTNS.
TONIGHT...WEAK SFC HIGH PRESSURE IS FORECAST TO BUILD ACROSS THE
CAROLINAS. AT H5...THE RIDGE AXIS IS EXPECTED TO RIPPLE OVER EASTERN
KY/TN BY 12Z TUESDAY. CONDITIONS ACROSS THE CWA SHOULD REMAIN DRY
WITH LIGHT WINDS. IN ADDITION...SKY WILL BECOME PARTLY CLOUDY UNDER
HIGH AND MID CLOUDS. LOW TEMPERATURES ARE FORECAST TO RANGE FROM THE
MID 40S WITHIN THE MTN VALLEYS TO LOW 50S EAST.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 220 AM MON...AN UPPER RIDGE BUILDS OVER THE AREA FROM THE SW
TUE AND TUE NITE. EVEN WITH THE RIDGE IN PLACE...A WEAK SHORT WAVE
MOVES THRU THE RIDGE AND ACROSS THE AREA TUE. AT THE SFC...HIGH
PRESSURE OVER THE ARE IS KNOCKED DOWN AS A WEAK WARM FRONT MOVES
EAST ACROSS NC. THE SHORT WAVE AND WARM FRONT MAY BE ENUF TO
OVERCOME THE LOW LEVEL WARM NOSE AND ALLOW CONVECTION TO INITIATE
ACROSS THE MTNS DURING THE AFTERNOON. THE ATMOS OUTSIDE OF THE MTNS
SHUD REMAIN CAPPED WITH ANY INSTABILITY WELL ABOVE THE SFC WITH VERY
HIGH LFC HEIGHT. HAVE INCLUDED SLIGHT CHC POP ALONG AND NEAR THE
BLUE RIDGE AND HIGHER TERRAIN WEST OF AVL AND NEAR THE NC/SC/GA
BORDERS. ANY CONVECTION THAT DOES DEVELOP SHUD QUICKLY TAPER OFF
DURING THE EARLY EVENING WITH LOSS OF HEATING AND FORCING MOVING
EAST. HIGHS TUE AND LOWS TUE NITE SHUD BE NEAR TO SLIGHTLY ABOVE
NORMAL.
THE UPPER RIDGE CONTINUES TO WEAKEN WED AND WED NITE AS NWLY FLOW
DEVELOPS OVER THE AREA BETWEEN AN UPPER LOW MOVING THRU THE GREAT
LAKES AND UPPER ANTICYCLONE SLOWLY MOVING EAST ALONG THE WRN GULF
COAST. A FEW WEAK SHORT WAVES WILL MOVE ACROSS THE AREA IN THE FLOW
AS A LEE TROF DEVELOPS AHEAD OF A BACK DOOR COLD FRONT DROPPING THRU
THE OH VALLEY. EVEN WITH THESE FEATURES...INSTABILITY REMAINS
LIMITED OUTSIDE OF THE MTNS AS LOW LEVEL WARM NOSE ACTUALLY
INCREASES PUSHING LFC HEIGHTS EVEN HIGHER. HOWEVER...ACROSS THE MTNS
ALONG THE TN BORDER...THE WARM NOSE ERODES ALLOWING LFC HEIGHTS TO
FALL AND INSTABILITY TO APPROACH MODERATE LEVELS. STILL EXPECT
COVERAGE TO REMAIN ISOLATED AS THE FORCING/INSTABILITY COMBO REMAINS
WEAK. HOWEVER...SHRA COULD LINGER THRU THE NITE AS THE BACK DOOR
FRONT MOVES CLOSER AND LOW LEVEL MOISTURE REMAINS HIGH. HIGHS WED
RISE TO AROUND 10 DEGREES ABOVE NORMAL AS THICKNESSES CONTINUE TO
RISE. LOWS WED NITE WILL RISE TO 5 TO 10 DEGREES ABOVE NORMAL.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...NWLY FLOW REMAINS ACROSS THE AREA THRU MUCH OF
THE MEDIUM RANGE AS THE REGION REMAINS BETWEEN AN UPPER LOW SLOWLY
MOVING FROM THE GREAT LAKES TO OFF THE NEW ENGLAND COAST...AND UPPER
RIDGE BUILDING OVER THE CENTRAL CONUS. THE FLOW BECOMES NLY SUNDAY
AS BOTH FEATURES MOVE EAST. AT THE SFC...A BACK DOOR COLD FRONT
MOVES SOUTH ACROSS THE AREA THU...STALLS JUST SOUTH OF THE AREA
FRI...THEN MOVES TO NEAR THE GULF COAST SAT AS HIGH PRESSURE BUILDS
IN FROM THE NORTH. THE CENTER OF THE HIGH PRESSURE MOVES INTO THE
AREA SUNDAY. EXPECT MAINLY DIURNALLY DRIVEN SCATTERED CONVECTION TO
DEVELOP ACROSS THE NC MTNS THU...WITH ISOLATED CONVECTION ACROSS THE
REST OF NC AHEAD OF THE COLD FRONT. ISOLATED DIURNAL CONVECTION
DEVELOPS ACROSS THE AREA FRIDAY WITH LOTS OF LOW LEVEL MOISTURE
REMAINING IN PLACE AND A WAVE MOVING NEAR THE AREA ALONG THE STALLED
FRONT. CHANCE OF CONVECTION DIMINISHES GREATLY SAT AND SUNDAY AS THE
DRIER HIGH PRESSURE MOVES IN FROM THE NORTH. HIGHS AROUND 10 DEGREES
ABOVE NORMAL THU...FALL TO AROUND 5 DEGREES ABOVE NORMAL FRI...THEN
A FEW DEGREES ABOVE NORMAL SAT AND SUNDAY. LOWS 5 TO 10 DEGREES
ABOVE NORMAL THU NITE FALL TO NEAR NORMAL FRI AND SAT NITES.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AT KCLT...AT 530Z...OBSERVATIONS SURROUNDING KCLT RANGED FROM IFR TO
VFR...WITH VIS AT THE TERMINAL REMAINING VFR. CLEAR SKY COVER AND
CALM WINDS THROUGH SUNRISE WOULD FAVOR THE DEVELOPMENT OF FOG. THE
LATEST MOS INDICATE THAT VIS WILL REMAIN VFR THIS MORNING.
HOWEVER...NAM12 AND LATEST HRRR INDICATES THAT VERY LOW VALUES OF
CONDENSATION PRESSURE DEFICITS WILL DEVELOP OVER KCLT DURING THE PRE
DAWN HOURS. I WILL HIGHLIGHT THE POTENTIAL OF FOG WITH A TEMPO GROUP
FROM 9Z-12Z FOR MVFR FOG. THE FOG AND ANY LOW CLOUDS SHOULD
DISSIPATE SHORTLY AFTER SUNRISE. ON MONDAY...THE CENTER OF HIGH
PRESSURE WILL SLIDE OVER THE MID ATLANTIC COAST. AS THE HIGH
APPROACHES...WINDS WILL VEER FROM EAST AROUND SUNRISE TO
SOUTH-SOUTHEAST BY MONDAY EVENING....SPEEDS WILL REMAIN LESS THAN 10
KTS. SCT CU MAY DEVELOP AROUND 060 KFT BY 17Z.
ELSEWHERE...MOS AND CONDENSATION PRESSURE DEFICITS INDICATE THAT THE
GREATEST POTENTIAL FOR FOG WILL REMAIN ACROSS THE UPSTATE OF SC AND
WITHIN THE MTN VALLEYS THIS MORNING. I WILL INDICATE THAT CEILINGS
AND VIS WILL GRADUALLY DECREASE THROUGH SUNRISE. FOG IS FORECAST TO
FALL TO LIFR AT KAND AND KAVL...WITH IFR ELSEWHERE. I WILL INDICATE
A PRE DAWN TEMPO FOR MVFR AT KHKY. THE FOG AND ANY LOW CLOUDS SHOULD
DISSIPATE SHORTLY AFTER SUNRISE. ON MONDAY...THE CENTER OF HIGH
PRESSURE WILL SLIDE OVER THE MID ATLANTIC COAST. AS THE HIGH
APPROACHES...WINDS WILL VEER FROM EAST AROUND SUNRISE TO
SOUTH-SOUTHEAST BY MONDAY EVENING....SPEEDS WILL REMAIN LESS THAN 10
KTS. SCT CU MAY DEVELOP AROUND 060 KFT BY 17Z.
OUTLOOK...DRY RIDGING WILL CONTINUE THROUGH MID WEEK. A BACKDOOR
COLD FRONT MAY DROP ACROSS THE AREA LATER IN THE WEEK...PROVIDING A
FOCUS FOR SCATTERED TS.
CONFIDENCE TABLE...
07-13Z 13-19Z 19-01Z 01-07Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP LOW 47% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 64% HIGH 84% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU LOW 59% HIGH 100% HIGH 100% HIGH 100%
KAND MED 75% HIGH 92% HIGH 100% 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...RWH
NEAR TERM...NED
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
157 AM EDT MON MAY 19 2014
.SYNOPSIS...
HIGH PRESSURE IS EXPECTED TO BUILD INTO THE REGION TONIGHT AND
PERSIST INTO WEDNESDAY BRINGING MUCH WARMER TEMPERATURES BY MID
WEEK. A BACK DOOR COLD FRONT SLOWLY SLIPS INTO THE REGION LATE
THURSDAY AND FRIDAY WITH A SMALL CHANCE OF RAIN AND A LITTLE COOLER
TEMPERATURES.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 145 AM...I WILL UPDATE THE FORECAST TO FINE TUNE THE PLACEMENT
AND TIMING OF FOG THIS MORNING. TEMPERATURES WILL SLOWLY COOL
BETWEEN 3-6 DEGREES BY SUNRISE. I WILL UPDATE THE FORECAST TO
INDICATE DENSE FOG ACROSS THE LAKELANDS AND WITHIN PORTIONS OF THE
MTN VALLEYS.
AS OF 1015 PM...CONDITIONS LOOK GOOD FOR AT LEAST AREAS OF FOG
ACROSS A LARGE PORTION OF THE CWFA...AS DEWPTS REMAIN ELEVATED IN
THE LWR-MID 50S...WHILE SKIES CLEAR AND WINDS REMAIN LIGHT. GUIDANCE
SEEMS TO BE TRENDING IN THAT DIRECTION AS WELL...WITH THE
NAM...RAP..NARRE ALL SHOWING GOOD POSSIBILITY OF DENSE FOG. I
CONSIDERED ISSUING A DENSE FOG ADVISORY FOR AT LEAST THE UPPER
SAVANNAH VALLEY AND SOUTHERN UPSTATE WITH THIS UPDATE.
HOWEVER...CONFIDENCE IS STILL JUST A BIT TOO LOW...AS SOME
STRATOCUMULUS LINGER. THE NAM STILL SHOWS AN EASTERLY COMPONENT TO
THE 925-850 MB FLOW...AND THE 18Z GFS HAS TRENDED THAT WAY. SO THERE
MAY BE A MIX OF CLOUDS WELL INTO THE OVERNIGHT. WITH THAT SAID...I
HAVE BUMPED UP WORDING TO AREAS OF FOG IN THESE MENTIONED
AREAS...AND MENTION DENSE FOG IN THE HWO. OTHERWISE...NO SIGNIFICANT
CHANGES TO THE FCST.
AS OF 730 PM...FOR THE 2330 UTC UPDATE...ALL MENTIONABLE POPS WERE
REMOVED...AS RADAR SHOWS RAIN HAS ENDED. ALSO UPDATED THE
SKY/WIND/WX FOR THE 00Z TAFS. THE MAIN THING TO NOTE IS THAT SKIES
ARE FINALLY STARTING TO CLEAR A LITTLE MORE RAPIDLY RIGHT BEFORE
NIGHTFALL. THE LATEST DEWPTS ARE RUNNING ON THE HIGH SIDE OF THE
GUIDANCE ACRS THE SWRN HALF OF THE CWFA...BUT LOWER IN THE NE CORNER
IN THE NW NC PIEDMONT. OVERALL...GUIDANCE SEEMS TO BE TRENDING A BIT
FOGGIER. I/LL AWAIT TRENDS INTO THE FIRST COUPLE OF NIGHTTIME HOURS
AND SOME MORE GUIDANCE COMING IN AND DO ANOTHER UPDATE ON FOG
WORDING IN THE GRIDS. HOWEVER...CONFIDENCE STILL TOO LOW FOR ANY
KIND OF DENSE FOG ADVISORY.
AS OF 430 PM...FOR THE 2030 UTC UPDATE...AREA OF LIGHT RAIN
CONTINUES TO WORK ACRS THE GA AND SC PIEDMONTS...WHILE SKIES CLEAR
FROM NORTH TO SOUTH ACRS NC. ONLY MINOR TWEAKS WERE MADE TO
TEMPS/DEWPTS/SKY TO LINE UP WITH OBS/SAT. POPS LOOK ON TRACK.
AS OF 215 PM...LIGHT RAIN CONTINUES TO GRADUALLY SHIFT SOUTH THIS
AFTERNOON. POPS HAVE BEEN REMOVED ACROSS MUCH OF WESTERN NC FOR THE
REMAINDER OF THE NEAR TERM PERIOD. AN EXCEPTION IS THAT THE
CONVECTION ALLOWING MODELS ARE SUGGESTING SOME POTENTIAL FOR SHOWER
DEVELOPMENT ACROSS THE HIGH TERRAIN THIS AFTERNOON. INDEED...
THINNING OF THE WIDESPREAD CLOUD COVER ACROSS THE MTNS IS REVEALING
A FAIRLY HEALTHY CU FIELD ACROSS THE SOUTHERN APPALACHIANS. WE HAVE
THEREFORE RETAINED SMALL POPS ACROSS THE SOUTHERN NC MTNS.
OTHERWISE...PRECIP SHOULD BE NOTHING MORE THAN A MEMORY FOR THE
ENTIRE FORECAST AREA BY 00Z.
WHILE THE MID-UPPER LEVELS WILL BE DRYING...THE MAJOR SHORT TERM
MODELS ARE A BIT AT ODDS WITH THE EVOLUTION OF LOW LEVEL MOISTURE
DEPTH LATE TONIGHT. THE NAM RETAINS QUITE A BIT OF LOW LEVEL
MOISTURE...AND TURNS WINDS AROUND TO A LIGHT E/SE UPSLOPE FLOW. THAT
COULD RESULT QUITE A BIT OF STRATUS DEVELOPING NEAR THE ESCARPMENT.
THIS IS LIKELY WHY NAM-RELATED GUIDANCE IS QUITE WARM FOR TONIGHT.
MEANWHILE...THE GFS AND EVEN MOST OF THE MESOSCALE MODELS ARE NOT AS
MOIST AND UPSLOPE...SO WE HAVE STUCK CLOSER TO COOL MAV GUIDANCE...
WITH TEMPS EXPECTED TO AVERAGE 10-15 DEGREES BELOW CLIMO. DEPENDING
UPON HOW LOWER CLOUDS EVOLVE (IF AT ALL)...FOG/LOW STRATUS COULD
BECOME AN ISSUE...ESP IN MTN VALLEYS.
DRY NW FLOW ALOFT WILL KEEP PRECIP CHANCES AT BAY ON MONDAY...WHILE
THE INFLUENCE OF THE PROGRESSING EAST COAST/WESTERN ATLANTIC TROUGH
WILL ALLOW FOR ONE MORE DAY OF COOLER THAN NORMAL WEATHER...WITH MAX
TEMPS EXPECTED TO AVERAGE ABOUT 5 DEGREES BELOW CLIMO.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
AS OF 215 PM EDT...THE SHORT TERM PERIOD WILL REMAIN RATHER QUIET AS
PREVIOUSLY FORECAST DUE TO INCREASED DEEP LAYER RIDGING ACROSS THE
SOUTHEAST. THAT SAID...STRONG SOUTHERLY FLOW ON THE WESTERN FLANK
OF SURFACE HIGH PRESSURE WILL ALLOW FOR TEMPERATURES/DEWPOINTS TO
SURGE ON TUESDAY AS A WARM FRONT SPREADS INTO THE REGION. ALTHOUGH
LOW/MID LEVEL CAPPING WILL REMAIN PREVALENT...A WEAK SHORT WAVE
IMPULSE WILL PASS ALONG THE UPPER RIDGE AIDING IN POTENTIAL CIN
EROSION AND CORRESPONDING CONVECTIVE INITIATION ACROSS THE HIGH
TERRAIN OF WESTERN NC. THEREFORE....FCST NOW FEATURES SLIGHT CHANCE
POPS ALONG THE SPINE OF THE APPS WITH NO MENTIONABLE POPS FURTHER
SOUTH AND EAST. THESE POPS WILL TAPER QUICKLY AROUND SUNSET AS
DIURNAL HEATING IS LOST AND THE WEAK IMPULSE EJECTS FROM THE AREA.
ABOVE MENTIONED SURFACE HIGH PRESSURE WILL ELONGATE AND ACTUALLY
RETROGRADE TO THE WEST ALONG THE GULF COAST ON WEDNESDAY. IN
RESPONSE...SOUTHERLY FLOW WILL VEER MORE WESTERLY ALLOWING PROFILES
TO DRY OUT IN THE MID LEVELS. THIS WILL WORK TO STRENGTHEN THE
CAPPING INVERSION LEADING TO A DRY FORECAST FOR THE ENTIRE CWFA WITH
THE EXCEPTION OF THE NORTHERN NC MOUNTAINS. SLIGHT CHANCE POPS WILL
REMAIN IN THE FORECAST FOR THESE ZONES DUE TO MODEL CONSENSUS
DESPITE LOW CONFIDENCE LEVEL IN CAP EROSION. THE ABOVE MENTIONED
INTRUDING WARM FRONT WILL ALLOW TEMPERATURES TO INCREASE TO NORMAL
LEVELS ON TUESDAY...WITH HIGHS REACHING 5-7 DEGREES ABOVE NORMAL BY
WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
CA
AS OF 2 PM EDT SUNDAY...THIS MEDIUM RANGE FORECAST BEGINS WED
EVENING WITH A WARM 500MB RIDGE WITH ITS 539 DEM CENTER OVER
MISSISSIPPI AND A CLOSED 500MB LOW MOVING SE FROM JUST NORTH OF THE
GREAT LAKES. ALSO AT THAT TIME...A SLOW MOVING COLD FRONT OVER THE
OHIO VALLEY AND VIRGINIAS DROPPING SOUTH WITH HIGHEST CAPES OVER KY
MOVING TO TN. LOW LEVEL FLOW INTO OUR AREA WILL BE WEST WED NIGHT
AND NW THURSDAY AND NIGHT AROUND THE STACKED HIGH CENTER. THIS FLOW
FROM THE NW WILL ENHANCE DOWNSLOPE ON THURSDAY WARMING FOOTHILLS AND
PIEDMONT AT LEAST TO AROUND 90. SMALL CHANCES OF SHOWERS AND STORMS
ON THURSDAY AND FRIDAY MAINLY OVER MTNS AS MINIMAL LOW LEVEL
CONVERGENCE AND CAPES NOT TOO IMPRESSIVE FOR THIS TIME OF YEAR EAST
OF MTNS. THE GFS...ECMWF AND CANADIAN HAVE A SMALL MCS MOVING SE
FROM TN INTO THE NC MTNS LATE THURSDAY THEN DISSIPATE IT COMING SE
OUT OF MTNS. CONVECTION DEVELOPING FRIDAY AFTERNOON HAS A BETTER
POTENTIAL FOR SURVIVING AS IT CROSSES FROM THE MTNS TO NE GA AND THE
UPSTATE. COLD FRONT PASSES SOUTH OF OUR AREA FRIDAY NIGHT INTO
SATURDAY WITH LOW LEVEL WIND FLOW BECOMING MOSTLY LIGHT FROM N AND
NE. THE 500MB TROUGH AXIS WILL BE OVER OHIO RIVER EARLY SATURDAY AND
CROSS THE CAROLINAS SATURDAY NIGHT AND SUNDAY WITH WEAK SURFACE HIGH
PRESSURE CENTERED OVER WEST VIRGINIA AT 00Z MONDAY.
THEREFORE...BEST CHANCES OF RAIN ON THURS AND FRI IN THIS EXTENDED
FORECAST...ALONG THE SLOWLY PASSING COLD FRONT. TEMPERATURES AROUND
10 DEGREES ABOVE NORMAL THURSDAY THEN DROPPING TO NEAR OR JUST ABOVE
NORMAL OVER THE WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AT KCLT...AT 530Z...OBSERVATIONS SURROUNDING KCLT RANGED FROM IFR TO
VFR...WITH VIS AT THE TERMINAL REMAINING VFR. CLEAR SKY COVER AND
CALM WINDS THROUGH SUNRISE WOULD FAVOR THE DEVELOPMENT OF FOG. THE
LATEST MOS INDICATE THAT VIS WILL REMAIN VFR THIS MORNING.
HOWEVER...NAM12 AND LATEST HRRR INDICATES THAT VERY LOW VALUES OF
CONDENSATION PRESSURE DEFICITS WILL DEVELOP OVER KCLT DURING THE PRE
DAWN HOURS. I WILL HIGHLIGHT THE POTENTIAL OF FOG WITH A TEMPO GROUP
FROM 9Z-12Z FOR MVFR FOG. THE FOG AND ANY LOW CLOUDS SHOULD
DISSIPATE SHORTLY AFTER SUNRISE. ON MONDAY...THE CENTER OF HIGH
PRESSURE WILL SLIDE OVER THE MID ATLANTIC COAST. AS THE HIGH
APPROACHES...WINDS WILL VEER FROM EAST AROUND SUNRISE TO
SOUTH-SOUTHEAST BY MONDAY EVENING....SPEEDS WILL REMAIN LESS THAN 10
KTS. SCT CU MAY DEVELOP AROUND 060 KFT BY 17Z.
ELSEWHERE...MOS AND CONDENSATION PRESSURE DEFICITS INDICATE THAT THE
GREATEST POTENTIAL FOR FOG WILL REMAIN ACROSS THE UPSTATE OF SC AND
WITHIN THE MTN VALLEYS THIS MORNING. I WILL INDICATE THAT CEILINGS
AND VIS WILL GRADUALLY DECREASE THROUGH SUNRISE. FOG IS FORECAST TO
FALL TO LIFR AT KAND AND KAVL...WITH IFR ELSEWHERE. I WILL INDICATE
A PRE DAWN TEMPO FOR MVFR AT KHKY. THE FOG AND ANY LOW CLOUDS SHOULD
DISSIPATE SHORTLY AFTER SUNRISE. ON MONDAY...THE CENTER OF HIGH
PRESSURE WILL SLIDE OVER THE MID ATLANTIC COAST. AS THE HIGH
APPROACHES...WINDS WILL VEER FROM EAST AROUND SUNRISE TO
SOUTH-SOUTHEAST BY MONDAY EVENING....SPEEDS WILL REMAIN LESS THAN 10
KTS. SCT CU MAY DEVELOP AROUND 060 KFT BY 17Z.
OUTLOOK...DRY RIDGING WILL CONTINUE THROUGH MID WEEK. A BACKDOOR
COLD FRONT MAY DROP ACROSS THE AREA LATER IN THE WEEK...PROVIDING A
FOCUS FOR SCATTERED TS.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP LOW 58% HIGH 93% HIGH 100% HIGH 100%
KAVL LOW 55% MED 79% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU MED 61% HIGH 92% HIGH 100% HIGH 100%
KAND MED 75% HIGH 92% HIGH 100% 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...DEO
NEAR TERM...NED
SHORT TERM...CDG
LONG TERM...DEO
AVIATION...NED
SEE BELOW FOR AN UPDATED AVIATION FORECAST DISCUSSION.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
PCPN CHANCES EARLY IN THE PERIOD ARE THE MAIN ISSUE IN THE SHORT
RANGE. FOR TNT FRONTAL BOUNDARY WILL EDGE SLOWLY ACROSS NORTHEAST
SD AND INTO WESTERN MINNESOTA. WITHIN THE FRONTAL BOUNDARY A
NARROW AREA OF MIXED LAYER CAPES UP TO 1500 J/KG WILL EXIST.
MEANWHILE DEEP LAYER SHEAR IS EXPECTED TO INCREASE TNT AS S/W
MOVES ACROSS STATE. WITH INSTABILITY AXIS SO NARROW SUSPECT THAT
IF ANY STORMS GET GOING OVER THE EAST THEY WILL BE DRIVEN MAINLY
BY WEAK FRONTAL CONVERGENCE AND DIABATIC HEATING NEAR FRONT. THIS
ACTIVITY SHOULD BE DONE BY SUNSET AND LIKELY WILL BE ISOLATED IN
COVERAGE AT BEST. FOR THE WESTERN CWA AM INCLINED TO THINK THAT
THE INCREASING WINDS ALOFT WITH S/W IN COMBINATION WITH SOME WEAK
MIXED LAYER CAPE COULD RESULT IN AN ISOLATED SHOWER/STORM BEFORE
HEATING ENDS. THE HRRR HAS COME AROUND TO THIS IDEA THUS WILL
INCLUDE SLIGHT CHC POPS THIS EVENING FOR WESTERN CWA. AFTER THIS
EVENING THE REST OF THE FORECAST LOOKS MAINLY DRY WITH RELATIVELY
MILD TEMPERATURES AS SFC HIGH BUILDS IN AND THEN REMAINS IN
COMMAND FOR A COUPLE DAYS.
.LONG TERM...THURSDAY THROUGH MONDAY
IT FINALLY APPEARS THE REGION WILL STAY IN A MILD/WARM PATTERN
INTO AT LEAST EARLY NEXT WEEK. TO START OFF THE PERIOD THURSDAY
AND FRIDAY...MUCH OF THE CWA IS STILL FEELING EFFECTS OF STABLE
SURFACE HIGH AS IT SLOWLY DEPARTS TO THE EAST. CONFINED PRECIP
CHANCES TO MAINLY WESTERN PORTIONS OF THE AREA DURING THIS TIME.
THINGS GET MORE INTERESTING...WHILE AT THE SAME TIME...MORE
UNCERTAIN AS WE HEAD INTO THE WEEKEND AND EARLY NEXT WEEK. MODELS
WOULD SUGGEST A BIT MORE MOISTURE CREEPING NORTHWARD INTO THE
REGION WITH PERHAPS DEWPOINTS AROUND 60 DEGREES. INSTABILITY
INCREASES WITH UPPER LEVEL DISTURBANCES CROSSING THE REGION. IT
WOULD APPEAR PATTERN TRIES TO GET STORMIER THIS WEEKEND INTO EARLY
NEXT WEEK...WHILE STAYING MILD. COULD BE LOOKING AT A FEW ROUNDS
OF THUNDERSTORMS. THERE ARE SOME DIFFERENCES AMONGST THE MODELS IN
REGARDS TO THEIR HANDLING OF THE MAIN UPPER LOW AS IT EJECTS OUT
INTO THE PLAINS. ALTHOUGH...OVERALL BIGGER PICTURE SHOWS SEVERAL
WAVES OF ENERGY EJECTING ACROSS THE CENTRAL AND NORTHERN PLAINS AS
THIS UPPER LOW SLOWLY MOVES OUT OVER THE PLAINS.
&&
.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
EXPECT VFR CONDITIONS TO PERSIST THROUGH AT LEAST TUESDAY MORNING.
THE RAPID REFRESH MODEL SUGGESTS MVFR STRATUS COULD WORK ITS WAY
SOUTHWARD INTO THE REGION DURING DAYLIGHT HOURS ON TUESDAY.
CONFIDENCE IN THAT OCCURRING IS A LITTLE LOW AT THIS POINT. WILL
TAKE THE RAPID REFRESH`S OUTPUT UNDER ADVISEMENT...BUT CONTINUE
WITH VFR FOR THE ENTIRE TAF VALID PERIOD FOR NOW.
ALSO...THERE IS A BOUNDARY WORKING EAST TOWARD KATY EARLY THIS
EVENING...WHICH COULD SPARK A THUNDERSTORM OR TWO AT OR NEAR KATY
ONCE WHOLESALE LIFT FROM A WEAK LOW PRESSURE SYSTEM WORKING
THROUGH CATCHES UP TO IT. CONVECTIVE CHANCES ARE RATHER LOW AND
LOOK TO ONLY PERSIST FOR A COUPLE MORE HOURS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...DORN
SHORT TERM...TDK
LONG TERM...TMT
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
330 PM CDT MON MAY 19 2014
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
PCPN CHANCES EARLY IN THE PERIOD ARE THE MAIN ISSUE IN THE SHORT
RANGE. FOR TNT FRONTAL BOUNDARY WILL EDGE SLOWLY ACROSS NORTHEAST SD
AND INTO WESTERN MINNESOTA. WITHIN THE FRONTAL BOUNDARY A NARROW
AREA OF MIXED LAYER CAPES UP TO 1500 J/KG WILL EXIST. MEANWHILE
DEEP LAYER SHEAR IS EXPECTED TO INCREASE TNT AS S/W MOVES ACROSS
STATE. WITH INSTABILITY AXIS SO NARROW SUSPECT THAT IF ANY STORMS
GET GOING OVER THE EAST THEY WILL BE DRIVEN MAINLY BY WEAK FRONTAL
CONVERGENCE AND DIABATIC HEATING NEAR FRONT. THIS ACTIVITY SHOULD
BE DONE BY SUNSET AND LIKELY WILL BE ISOLATED IN COVERAGE AT BEST.
FOR THE WESTERN CWA AM INCLINED TO THINK THAT THE INCREASING
WINDS ALOFT WITH S/W IN COMBINATION WITH SOME WEAK MIXED LAYER
CAPE COULD RESULT IN AN ISOLATED SHOWER/STORM BEFORE HEATING
ENDS. THE HRRR HAS COME AROUND TO THIS IDEA THUS WILL INCLUDE
SLIGHT CHC POPS THIS EVENING FOR WESTERN CWA. AFTER THIS EVENING
THE REST OF THE FORECAST LOOKS MAINLY DRY WITH RELATIVELY MILD
TEMPERATURES AS SFC HIGH BUILDS IN AND THEN REMAINS IN COMMAND FOR
A COUPLE DAYS.
.LONG TERM...THURSDAY THROUGH MONDAY
IT FINALLY APPEARS THE REGION WILL STAY IN A MILD/WARM PATTERN
INTO AT LEAST EARLY NEXT WEEK. TO START OFF THE PERIOD THURSDAY
AND FRIDAY...MUCH OF THE CWA IS STILL FEELING EFFECTS OF STABLE
SURFACE HIGH AS IT SLOWLY DEPARTS TO THE EAST. CONFINED PRECIP
CHANCES TO MAINLY WESTERN PORTIONS OF THE AREA DURING THIS TIME.
THINGS GET MORE INTERESTING...WHILE AT THE SAME TIME...MORE
UNCERTAIN AS WE HEAD INTO THE WEEKEND AND EARLY NEXT WEEK. MODELS
WOULD SUGGEST A BIT MORE MOISTURE CREEPING NORTHWARD INTO THE
REGION WITH PERHAPS DEWPOINTS AROUND 60 DEGREES. INSTABILITY
INCREASES WITH UPPER LEVEL DISTURBANCES CROSSING THE REGION. IT
WOULD APPEAR PATTERN TRIES TO GET STORMIER THIS WEEKEND INTO EARLY
NEXT WEEK...WHILE STAYING MILD. COULD BE LOOKING AT A FEW ROUNDS
OF THUNDERSTORMS. THERE ARE SOME DIFFERENCES AMONGST THE MODELS IN
REGARDS TO THEIR HANDLING OF THE MAIN UPPER LOW AS IT EJECTS OUT
INTO THE PLAINS. ALTHOUGH...OVERALL BIGGER PICTURE SHOWS SEVERAL
WAVES OF ENERGY EJECTING ACROSS THE CENTRAL AND NORTHERN PLAINS AS
THIS UPPER LOW SLOWLY MOVES OUT OVER THE PLAINS.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
MVFR CIGS LINGERING AT KATY AND WILL CONTINUE TO SEE GRADUAL
IMPROVEMENT OF THE LOWER CIGS BY 20Z OR SO WHEN CIGS SHOULD BE
INTO VFR. OTHERWISE...EXPECT VFR CONDITIONS AT THE OTHER TAF
SITES. THERE MAY BE A FEW ISOLD -SHRA OR -TSRA DOTTING THE RADAR
THIS AFTERNOON...BUT OVERALL CONFIDENCE IN OCCURRENCE AND AREAL
COVERAGE IS LOW...SO WILL CONTINUE TO MONITOR AND INSERT MENTION
INTO TAFS AS NECESSARY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
SHORT TERM...TDK
LONG TERM...TMT
AVIATION...TMT
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
231 PM CDT MON MAY 19 2014
.DISCUSSION...
AT 2 PM...AN AREA OF LOW PRESSURE WAS LOCATED OVER WESTERN KANSAS
AND A DRY LINE EXTENDED ACROSS THE OK/TX PANHANDLE TO AROUND THE
BIG BEND. THE PRESSURE GRADIENT REMAINS MODERATELY TIGHT WITH
BREEZY S-SE SFC WINDS. VERY LITTLE CHANGE TO THE CURRENT FORECAST
AS UPPER LEVEL RIDGING BUILDS OVER TEXAS. THE 4KM WRF AND HRRR ALL
SHOW SOME EARLY MORNING STREAMER SHOWERS TOMORROW MORNING BUT
OTHER THAN THAT THE AREA IS EXPECTED TO REMAIN DRY THROUGH SUNDAY.
A GRADUAL WARMING TREND IS EXPECTED AS HEIGHTS SLOWLY BUILD. AN
UPPER LEVEL TROUGH WILL APPROACH THE STATE LATE IN THE WEEKEND.
THE UPPER LEVEL RIDGE WILL MOVE A BIT TO THE EAST AS THE TROUGH
APPROACHES BUT THE UPPER TROUGH LOOKS LIKE IT WILL GET SHUNTED
TO THE NORTHWEST OF THE SLOWLY RETREATING UPPER RIDGE. THE UPPER
TROUGH STILL LOOKS TO GET CLOSE ENOUGH TO PROVIDE THE AREA WITH A
SLIGHT CHANCE OF PRECIPITATION BEGINNING NEXT MONDAY. OVERALL...
RAIN CHANCES LOOK TO REMAIN LOW FOR THE NEXT 7 TO 10 DAYS WITH
TEMPERATURES NEAR NORMAL VALUES. 43
&&
.MARINE...
LITTLE TO NO CHANGE OVER THE NEXT SEVERAL DAYS. NORTHEASTERN BASED
SURFACE HIGH PRESSURE WITH LOWER WESTERN PLAINS PRESSURE WILL
MAINTAIN A PERSISTENT LIGHT...TO OCCASIONALLY MODERATE...SOUTHEAST
FETCH ACROSS THE LOCAL WATERS. BAY WATER CONDITIONS AND GULF SEA
HEIGHTS WILL REMAIN SLIGHTLY CHOPPY TO WITHIN 2 TO 4 FEET...RESPECTIVELY.
UPPER RIDGING OVER THE GULF WILL SUPPRESS PRECIPITATION...ANY RAIN
ACTIVITY LIMITED TO JUST BRIEF NORTHERN-PASSING EARLY MORNING
SHOWERS. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 70 86 70 87 67 / 10 10 10 10 10
HOUSTON (IAH) 69 86 70 86 68 / 10 10 10 10 10
GALVESTON (GLS) 72 82 73 82 73 / 10 10 10 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1014 PM CDT TUE MAY 20 2014
.UPDATE...THE LAKE BREEZE HAS COOLED TEMPS INTO THE UPPER 40S TO
MID 50S NEAR THE LAKE ALONG WITH LIGHT FOG. AFTER THE SHOWERS END
AND CLOUDS DECREASE...THE FOG SHOULD INCREASE IN COVERAGE OVER ERN
WI. THE HIGH BASED SHOWERS OVER THE WRN CWA IS A RESULT OF MID
LEVEL FRONTOGENESIS OVER THE REGION. THE STRONGEST STORMS WILL
STAY SOUTH WHERE THE EFFECTIVE FRONT AND HIGHER INSTABILITY STILL
EXISTS ALONG WITH STRONGER FRONTOGENESIS. INCREASING WNWLY WINDS
WILL END THE FOG BY MID LATE WED AM.
&&
.AVIATION/06Z TAFS/...SCT SHOWERS AND ISOLD TSTORMS TO END DURING
THE OVERNIGHT. FOG AND STRATUS COMING FROM LAKE MI WILL AFFECT THE
ERN WI TAF SITES...ESPECIALLY KMKE UNTIL LATE WED AM WHEN WNWLY
WINDS BECOME ESTABLISHED. VSBYS WILL RANGE FROM 1-3 MILES WITH
STRATUS AROUND 400 FEET AT KMKE AND NEAR THE LAKE. VFR CONDITIONS
BY LATE WED AM INTO WED NT AS WNWLY WINDS BRING DRIER AIR TO THE
AREA.
&&
.MARINE...EASTERLY WINDS BROUGHT DENSE FOG INTO THE NEARSHORE
WATERS TUESDAY EVENING. THUS A DENSE FOG ADVISORY IS IN EFFECT
UNTIL 10 AM WEDNESDAY. BY LATE WEDNESDAY MORNING...WEST TO
NORTHWEST WINDS WILL DEVELOP AND BRING MILDER AND DRIER AIR OVER
THE LAKE...THEREBY ENDING THE FOG.
&&
.PREV DISCUSSION... /ISSUED 302 PM CDT TUE MAY 20 2014/
SHORT TERM...
REST OF THIS AFTERNOON AND TONIGHT - CONFIDENCE...MEDIUM
SPC MESO PAGE SHOWS PLENTY OF FAVORABLE PARAMETERS FOR THE SRN CWA.
MID LEVEL CAP SUPPRESSING THINGS A BIT BUT THIS IS PROGGD TO ERODE
WITH TIME. LOW LEVEL FLOW IS WEAK RESULTING IN UNFAVORABLE
0-1KM SHEAR. CONVERGENCE IS WEAK. MID LEVEL CAP IS A SUPPRESSING
FORCE. 850 LOW LEVEL JET IS WELL SOUTH AND NO DISCERNIBLE
SHORTWAVE UPSTREAM IN WATER VAPOR. ON THE PLUS SIDE 0-6KM SHEAR IS
INCREASING INTO SC WI AT 40-50 KNOTS. CRAVEN/BROOKS SHOWS 50,000
INTO SC WI. AGAIN..NOT MUCH ORGANIZATION IN THE LOW LEVELS WITH
WEAK FLOW AND BAGGY PRESSURE GRADIENT. MID LEVEL SPEED MAX AND
DIVERGENCE ASSOCIATED WITH THIS COMBINED WITH APPCH FRONTAL
FORCING WILL LIKELY GET THINGS GOING. HRRR/NAM/GFS ALL POTENTIAL
FOR MOST ORGANIZED DEVELOPMENT BETWEEN 00-06Z IN THE SRN TWO TIERS
WITH THE 4KM SPC WRF SHOWING ONLY ISOLATED DEVELOPMENT IN THE FAR
SOUTH WITH CONVECTION STAYING LARGELY TO OUR SOUTH. BULK OF DATA
SUPPORTS AT LEAST SOME ACTIVITY ALONG AND SOUTH OF I-94 THIS
AFTN/EVENING. IF THE STORMS GET GOING THEN LARGE HAIL LOOKS LIKE
THE MOST FAVORABLE THREAT DUE TO THE MID LEVEL LAPSE RATES AND
PLENTIFUL CAPE IN THE -10 TO -30C RANGE. SIGNIFICANT HAIL
PARAMETER HAS INCREASED MARKEDLY INTO SC WI THIS AFTN WITH MID
LEVEL LAPSE RATES OF AT LEAST 7.5C. CIPS ANALOGS ALSO HAS HIGHER
HAIL PROBABILITIES INTO SC WI AS WELL. DOWNDRAFT CAPE PUSHING 1000
NEAR THE BORDER SO SOME WIND THREAT THERE AS WELL. WILL HAVE
HIGHEST POPS THIS EVENING IN THE SRN CWA AND TRAIL THINGS OFF IN
THE NORTH. EXPECT ANY LINGERING CONVECTION TO QUICKLY EXIT THE
SOUTHEAST BY MIDNIGHT OR SHORTLY THEREAFTER.
WEDNESDAY - CONFIDENCE...MEDIUM
BROADLY CYCLONIC FLOW WITH BEST VORT ACTION WITHIN THIS FLOW WELL
NORTH AND NORTHEAST OF THE CWA. 850 COLD ADVECTION GRADUALLY
COMMENCES ...THOUGH ONLY SUBTLE COOLING AT 925 NOTED AFTER 18Z.
SO WILL FORECAST TOASTY TEMPS WELL INTO THE 70S WITH SOME AREAS AT
OR SLIGHTLY ABOVE 80 WITH PREDOMINANTLY WNW FLOW.
WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE HIGH.
A SHORTWAVE MOVES ACROSS SOUTHEAST CANADA JUST NORTH OF THE LAKE
SUPERIOR AND LAKE HURON AREA...WITH THE MID/UPPER LEVEL FLOW
MORE NORTHWEST ACROSS WISCONSIN. THE SPEED MAX INCREASES TO 105
KNOTS ACROSS CENTRAL AND SOUTHEAST WISCONSIN THURSDAY. 700 MB RH
DRIES WEDNESDAY NIGHT. 700/850 MB COLD AIR ADVECTION CONTINUES
WEDNESDAY NIGHT...THEN BEGINS TO RISE A LITTLE AT 850 MB LATER
THURSDAY. 850 MB RH INCREASES DURING THE DAY THURSDAY...SO SOME
FAIR WEATHER CUMULUS EXPECTED. FORECAST SOUNDINGS SHOW MOISTURE
IS CONFINED TO THE 850 MB LAYER JUST BELOW THE STRONG INVERSION.
THE SURFACE HIGH PRESSURE BUILDS INTO THE UPPER MISSISSIPPI
VALLEY AND WISCONSIN AREA THURSDAY. THE LIGHT NORTHWEST WINDS ARE
EXPECTED TO BECOME NORTHEAST OVER SOUTHEAST WISCONSIN...WITH LAKE
MICHIGAN COOLING DURING THE AFTERNOON.
THURSDAY NIGHT AND FRIDAY....FORECAST CONFIDENCE HIGH.
THE MID/UPPER LEVEL FLOW CONTINUES FROM THE NORTHWEST WITH A
STRONG RIDGE BUILDING OVER THE EASTERN DAKOTAS AND WESTERN
MINNESOTA. NAM FORECAST SOUNDINGS CONTINUE TO SHOW A SHALLOW
MOISTURE LAYER AT 850 MB. NOT THICK ENOUGH FOR ANYTHING MORE THAN
MAINLY SCATTERED AFTERNOON FAIR WEATHER CUMULUS.
THE SURFACE HIGH EXTENDS ACROSS WISCONSIN AND THE WESTERN GREAT
LAKES WITH A LIGHT NORTHEAST FLOW ACROSS SOUTHERN WISCONSIN.
LONG TERM...
SATURDAY AND SUNDAY...FORECAST CONFIDENCE MEDIUM.
THE MID/UPPER LEVEL RIDGE REMAINS NEAR THE UPPER MISSISSIPPI
VALLEY SATURDAY AND OVER WISCONSIN SATURDAY...BEFORE MOVING INTO
LOWER MICHIGAN SUNDAY.
THE SURFACE HIGH BECOMES CENTERED OVER THE GREAT LAKES AND UPPER
OHIO VALLEY SATURDAY AND OVER THE EASTERN GREAT LAKES AND
NORTHEAST U.S. SUNDAY. THIS BEGINS A SOUTH FLOW OF WARMER AIR. THE
12Z GFS AND 06Z DGEX SPREADS SOME LIGHT PRECIPITATION INTO
SOUTHERN WISCONSIN SUNDAY EXCEPT FOR THE FAR EAST...BUT THE 00Z
ECMWF REMAINS DRY EXCEPT FOR THE FAR WEST SUNDAY AFTERNOON AND IS
PREFERRED.
MONDAY AND TUESDAY...FORECAST CONFIDENCE MEDIUM.
THE MID/UPPER RIDGE REMAINS FROM THE SOUTHEAST U.S. TO THE EASTERN
GREAT LAKES WITH A TROUGH AND WEAK CUT OFF LOW OVER THE CENTRAL
PLAINS. THE GFS AND ECMWF ARE IN VERY GOOD AGREEMENT EVEN AT
DAY 7.
THE GFS/ECMWF AND DGEX ALL BRING PRECIPITATION LATER SUNDAY NIGHT
AND MONDAY AND CONTINUES IT ON TUESDAY AS THE SOUTH FLOW CONTINUES
WITH LOW PRESSURE OVER THE PLAINS.
AVIATION/00Z TAFS/...
MAIN CONCERN WILL BE CONVECTIVE TRENDS THIS
AFTN/EVE. ML CAPES HAVE REACHED 2000 PLUS. EXPECTING CONVECTION TO
BUBBLE UP FROM MID AFTERNOON INTO EARLY EVENING. PER SWODY1...AREAS
ALONG AND SOUTH OF I-94 ARE MORE UNDER THE GUN. LARGE CAPE VALUES IN
THE -10 TO -30C SO CONCERN FOR LARGE HAIL DEVELOPMENT. HRRR SHOWS
SCT CELLS DVLPG 22-00Z ACRS SRN WI WITH MORE ORGANIZED CONVECTION
BRUSHING THE FAR SOUTH AFTER EVENING DEVELOPMENT IN ERN IA. 850 COLD
ADVECTION INCREASES ON WEDNESDAY WITH CONVECTIVE FOCUS SHIFTING INTO
THE OH VLY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...DENSE FOG ADVISORY UNTIL 10 AM CDT WEDNESDAY FOR LMZ643>646.
&&
$$
UPDATE...GEHRING
TONIGHT/WEDNESDAY AND AVIATION/MARINE...COLLAR
WEDNESDAY NIGHT THROUGH TUESDAY...HENTZ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
635 PM CDT TUE MAY 20 2014
.UPDATE...
ISSUED AT 635 PM CDT TUE MAY 20 2014
SURFACE BASED CONVECTION FIRED ABOUT 2 HOURS AGO JUST SOUTH OF THE
FORECAST AREA...THROUGH THE DUBUQUE AREA...ALONG A SURFACE TROUGH
THERE. ANTICIPATING OUTFLOWS FROM THE CONVECTION WILL HELP TO KEEP
MUCH OF THE CONVECTION SOUTH OF THE FORECAST AREA THROUGH THE
EVENING...THUS HAVE CONTINUED TO TREND PRECIPITATION CHANCES DOWN
AND FARTHER SOUTH. APPEARS ONLY FAR SOUTHERN PORTIONS OF
GRANT...CLAYTON AND FAYETTE COUNTIES COULD BE CLIPPED BY
SHOWERS/STORMS COMING OUT OF CENTRAL IOWA.
MEANWHILE...A FRONTOGENETIC BAND OF HIGH BASED SHOWERS...EVEN A
FEW THUNDERSTORMS...HAS BEEN OCCURRING ACROSS NORTHWEST IOWA. WILL
HAVE TO MONITOR THIS FEATURE THROUGH THE EVENING TO SEE IF IT CAN
IMPACT SOUTHEAST MN. WOULD ANTICIPATE VERY LITTLE PRECIPITATION
DUE TO DRIER LOW LEVEL AIR THAT HAS BEEN INVADING THE AREA THIS
AFTERNOON. IN FACT...EVEN UNDER THE FRONTOGENETIC BAND...REPORTS
OF RAIN ARE HARD TO COME BY. 20.21Z RAP/HRRR GUIDANCE SUGGESTS THE
BAND WILL DIMINISH AS IT COMES INTO SOUTHEAST MN THIS EVENING...SO
GIVEN ALL OF THIS HAVE KEPT THE FORECAST DRY.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 258 PM CDT TUE MAY 20 2014
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL RIDGE
FLATTENING OUT OVER THE UPPER MIDWEST AND GREAT LAKES REGION. A VERY
WEAK SHORTWAVE TROUGH ON THE NORTHERN PERIPHERY OF THE UPPER LEVEL
RIDGE IS PRODUCING VERY LIGHT RAIN OR SPRINKLES ACROSS SOUTHERN
MINNESOTA PER LATEST MOSAIC RADAR. LATEST 19Z SURFACE ANALYSIS
INDICATING A WEAK COLD FRONT EXTENDING FROM CENTRAL WISCONSIN INTO
CENTRAL IOWA.
MAIN FORECAST CONCERNS ARE SHOWERS AND THUNDERSTORMS DEVELOPMENT
ALONG SURFACE FRONT LATE THIS AFTERNOON AND THIS EVENING. THE LATEST
20.12Z GFS/NAM AND 20.15Z RAP ARE INDICATING ALONG SURFACE FRONT CAP
WILL BREAK IN THE 22Z TUESDAY - 02Z WEDNESDAY TIME FRAME AND FOR
SHOWERS AND THUNDERSTORMS TO DEVELOP ALONG SURFACE FRONT PER BUFKIT
SOUNDINGS OVER EXTREME SOUTHERN FORECAST AREA. THE LATEST 20.16Z
HRRR DEVELOPS SHOWERS AND THUNDERSTORMS AROUND 23Z ACROSS SOUTHERN
FAYETTE...CLAYTON AND GRANT COUNTIES. THE 20.15Z RAP AND 20.12Z NAM
INDICATES ROUGHLY 1000-2000 J/KG OF SURFACE BASE CAPE AND 0-6KM
SHEAR APPROACHING 40 KNOTS LATE THIS AFTERNOON ALONG AND AHEAD
SURFACE FRONT ACROSS THE EXTREME SOUTHERN FORECAST AREA. THE 20.15Z
RAP/20.12Z NAM SHOW 0-1KM SHEAR LESS THAN 5 KNOTS OVER THIS AREA.
THE EXTREME SOUTHERN FORECAST AREA POSSIBLY COULD SEE SEVERE
THUNDERSTORMS WITH THE MAIN THREATS AT THIS TIME LOOK TO BE LARGE
HAIL AND WIND OVER THE EXTREME SOUTHERN FORECAST AREA.
SURFACE FRONT MOVES SOUTH OF FORECAST AREA WEDNESDAY AND DRIER AIR
AND SLIGHTLY COOLER AIR FILTERS INTO THE FORECAST AREA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 258 PM CDT TUE MAY 20 2014
SURFACE RIDGE BUILDS INTO THE FORECAST AREA THURSDAY INTO FRIDAY.
WITH SUBSIDENCE UNDERNEATH RIDGE AND FORECAST AREA UNDER NORTHERLY
FLOW. THIS SHOULD ALLOW FOR DRY WEATHER CONDITIONS AND SEASONABLE
TEMPERATURES ACROSS THE FORECAST AREA.
FOCUS THEN TURNS TO FRIDAY NIGHT INTO TUESDAY...WHERE THE MAIN
CONCERNS ARE PRECIPITATION CHANCES SATURDAY NIGHT INTO TUESDAY. THE
20.12Z GFS/ECMWF/GEM ARE IN GOOD AGREEMENT IN BUILDING UPPER
LEVEL RIDGE INTO THE CENTRAL UNITED STATES THIS WEEKEND...THEN
BREAKING DOWN UPPER LEVEL RIDGE AND DEVELOP SOUTHWEST FLOW OVER
THE CENTRAL UNITED STATES BY 00Z MONDAY. THE BIGGEST DIFFERENCES
BETWEEN THE MODELS IS TIMING AND STRENGTH OF SHORTWAVE TROUGHS
EJECTING OUT INTO THE NORTHERN PLAINS AND UPPER GREAT LAKES REGION
THROUGH THE PERIOD. THE FORECAST AREA SHOULD REMAIN DRY THROUGH
SATURDAY NIGHT AS UPPER LEVEL RIDGE DOMINATES THE GREAT LAKES
REGION. THEN...FIRST IMPULSE BEGINS TO BREAK RIDGE DOWN SUNDAY AND
PROVIDE THE POSSIBILITY OF SHOWERS AND THUNDERSTORMS INTO THE
WESTERN HALF OF THE FORECAST AREA. WITH UPPER LEVEL RIDGE BREAKING
DOWN OVER THE UPPER MIDWEST AND GREAT LAKES REGION MEMORIAL DAY
AND TUESDAY...A SERIES OF SHORTWAVE TROUGHS EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL MOVE OVER THE AREA. THE 20.12Z
GFS/ECMWF/GEM INDICATE STRENGTH ISSUES WITH EACH SHORTWAVE
TROUGH...HOWEVER THE SHORTWAVE TROUGH SHOW BETTER MOISTURE
TRANSPORT/CONVERGENCE OVER THE REGION BY 00Z TUESDAY. WILL
CONTINUE WITH CHANCES OF SHOWERS AND THUNDERSTORMS ACROSS FORECAST
AREA...ESPECIALLY LATE MEMORIAL DAY INTO TUESDAY. TEMPERATURES
FRIDAY NIGHT INTO TUESDAY WILL BE SLIGHTLY ABOVE NORMAL...AS THE
GFS/ECMWF/GEM INDICATE 850MB TEMPERATURES IN THE PLUS 14 TO PLUS
16 DEGREES CELSIUS RANGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 635 PM CDT TUE MAY 20 2014
A NORTHWEST FLOW OF DRY AIR...ASSOCIATED WITH HIGH PRESSURE
BUILDING IN FROM THE NORTHERN PLAINS...WILL HELP TO KEEP
CONDITIONS VFR THROUGH WEDNESDAY. SHOULD SEE SOME DIURNAL CUMULUS
FORM WEDNESDAY AFTERNOON...BUT EVEN THEN THE BASES LOOK TO STAY
VFR. REGARDING THAT NORTHWEST FLOW...WINDS ASSOCIATED WITH IT WILL
BE LIGHT TONIGHT. HOWEVER...EXPECT A COLD FRONTAL PASSAGE LATE
TONIGHT TO COMBINE WITH DAYTIME HEATING ON WEDNESDAY TO PICK UP
THE WINDS. 10-15 KT SPEEDS LOOK COMMON AT BOTH TAF SITES FROM LATE
MORNING ON...WITH GUSTS TO 20 KT POSSIBLE.
&&
.HYDROLOGY...
ISSUED AT 258 PM CDT TUE MAY 20 2014
WATER LEVELS CONTINUE TO SLOWLY FALL ALONG THE MISSISSIPPI RIVER AND
FEW LOCATIONS REMAIN ABOVE FLOOD STAGE. THE WATER LEVELS WILL REMAIN
HIGH ALONG THE MISSISSIPPI RIVER THROUGH NEXT WEEK.
IN ADDITION...DUE TO RECENT RAINFALL AMOUNTS OF ONE TO TWO AND A
HALF INCHES IN THE HEADWATERS OF THE BLACK RIVER. THE BLACK RIVER
HAS RISEN ABOVE FLOOD OR IS EXPECTED TO RISE ABOVE FLOOD STAGE AT A
COUPLE LOCATIONS OVER THE NEXT COUPLE OF DAYS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...AJ
HYDROLOGY...DTJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1258 PM CDT MON MAY 19 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 331 AM CDT MON MAY 19 2014
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH TUESDAY.
LOCAL RADAR SHOWING A FEW RETURNS OVER NORTHEAST IOWA EARLY THIS
MORNING THAT ARE MOVING EAST IN THE INITIAL BAND OF WARM AIR
ADVECTION AHEAD OF THE STORM SYSTEM OVER THE WESTERN DAKOTAS. THE
19.05Z HRRR SHOWS THESE SHOWERS TO CONTINUE MOVING EAST AND SLOWLY
DISSIPATING AS THEY MOVE OUT OF THE WARM AIR ADVECTION ZONE AND
INTO DRIER AIR AND THAT BY 12Z...WHAT REMAINS OF THEM SHOULD BE
OUT OF THE FORECAST AREA. THIS ALLOWS THE ATTENTION AND RAIN
CHANCES TO BE TIED TO THE SYSTEM COMING IN FROM THE WEST. THE
UPPER LEVEL RIDGE AXIS CURRENTLY OVER THE REGION WILL SLIDE TO THE
EAST TODAY ALLOWING A SOUTHWEST FLOW ALOFT TO DEVELOP. SEVERAL
SHORT WAVE TROUGHS ARE EMBEDDED IN THIS FLOW...BUT SOME
UNCERTAINTY ON HOW STRONG THESE WAVES WILL BE. GOOD CONSENSUS
AMONG THE MODELS THAT THE MAIN SHORT WAVE TROUGH IS CURRENTLY
MOVING ACROSS EASTERN MONTANA AND SHOULD TRACK ACROSS NORTHERN
MINNESOTA AND SOUTHERN CANADA TODAY. THE DIFFERENCES BETWEEN THE
MODELS COME WITH THE WEAKER SHORT WAVE TROUGH CURRENTLY FIRING
SOME CONVECTION OVER SOUTHERN SOUTH DAKOTA AND NEBRASKA. THE
19.00Z NAM AND GFS INTENSIFY THIS WAVE AS IT COMES EAST...ALMOST
APPEARING AS BOTH MODELS ARE SUFFERING SOME CONVECTIVE FEEDBACK
WITH IT. THE 19.00Z ECMWF AND GEM DO NOT SHOW THIS INTENSIFICATION
AND KEEP THE WAVE PRETTY WEAK AS IT SLIDES ACROSS THE AREA. THIS
WILL HAVE A BIG IMPACT ON HOW MUCH ACTIVITY CAN FORM ACROSS THE
AREA. WITH THE MORE NORTHERN WAVE BEING THE DOMINANT SYSTEM...ALL
THE MODELS SHOW THE LOW LEVEL MOISTURE TRANSPORT IS FOCUS AHEAD OF
THIS WAVE TAKING IT THROUGH THE AREA. HOWEVER...THERE IS A PERIOD
DURING THE MORNING INTO THE AFTERNOON WHERE THE AREA WILL BE ON
THE EASTERN AND CONVERGENT SIDE OF THIS MOISTURE TRANSPORT. THIS
MOISTURE TRANSPORT COMBINED WITH 2 TO 3 UBAR/S OF UP GLIDE ON THE
300K ISENTROPIC SURFACE AND THE LIFT FROM THE WAVE SHOULD BE
ENOUGH TO GENERATE SHOWERS. THE LIFT MAY BE A LITTLE BETTER ACROSS
THE NORTH CLOSER TO THE STRONGER SHORT WAVE TROUGH SO WILL
CONTINUE TO SHOW THE HIGHEST RAIN CHANCES ACROSS THE NORTH WITH 80
PERCENT TAPERING DOWN TO THE 30 TO 40 PERCENT RANGE ACROSS THE
SOUTH. NOT A WHOLE OF INSTABILITY IS EXPECTED TO BE IN PLACE TODAY
WITH THE NAM SHOWING AT MOST AROUND 500 J/KG OF MU CAPE ACROSS THE
FAR WEST DURING THE LATE AFTERNOON.
ANOTHER SHORT WAVE TROUGH IS EXPECTED TO COME ACROSS THE UPPER
MIDWEST THIS EVENING WITH THE SOUTHWEST FLOW ALOFT STILL IN PLACE.
THE MOISTURE TRANSPORT IS EXPECTED TO REMAIN THROUGH THE AREA INTO
THE NORTHERN SHORT WAVE TROUGH AS IT MOVES ACROSS SOUTHERN
ONTARIO. HOWEVER...ANOTHER ROUND OF ISENTROPIC UP GLIDE SHOULD
DEVELOP ACROSS THE AREA WITH THE NAM SHOWING THIS TO BE ON THE
ORDER OF 2 TO 4 UBAR/S ON THE 300K ISENTROPIC SURFACE. THIS UP
GLIDE WITH THE SHORT WAVE TROUGH SHOULD BE ENOUGH TO KEEP THE
SHOWERS GOING INTO THE EVENING BEFORE EVERYTHING SHIFTS OFF TO THE
EAST DURING THE OVERNIGHT HOURS. PLAN TO CONTINUE WITH THE 80
PERCENT CHANCES ACROSS THE NORTH TAPERING OFF TO 30 TO 40 PERCENT
ACROSS THE SOUTH.
THE SURFACE BOUNDARY IS THEN EXPECTED TO COME THROUGH EARLY
TUESDAY MORNING AND THEN IT SHOULD STALL EITHER ACROSS THE FAR
SOUTHERN PARTS OF THE AREA DURING THE AFTERNOON OR JUST TO THE
SOUTH OF THE AREA. GOOD CAPE IS EXPECTED TO DEVELOP NEAR THIS
BOUNDARY WITH AROUND 1500 J/KG OF ML CAPE SHOWN BY THE NAM ALONG
WITH 40 TO 50 KNOTS OF 0-6 KM SHEAR. HOWEVER...THERE DOES NOT LOOK
TO BE A GOOD TRIGGER TO SPARK DEVELOPMENT. UPPER LEVEL HEIGHTS
SHOULD BE BUILDING OVER THE AREA AND ONLY THE NAM SHOWS A WEAK
SHORT WAVE TROUGH COMING ACROSS. WITH MOST THE MODELS TRYING TO
SHOW SOME ACTIVITY ALONG THE FRONT...WILL CONTINUE TO HONOR THIS
WITH SOME 20 TO 30 PERCENT CHANCES ACROSS THE SOUTH...BUT
CONFIDENCE IS NOT HIGH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 331 AM CDT MON MAY 19 2014
ONCE THE UPPER LEVEL RIDGE BEGINS TO BUILD BACK OVER THE
REGION...THE MEDIUM RANGE MODELS INDICATE IT WILL REMAIN OVER THE
UPPER MIDWEST THROUGH THE PERIOD. SOME UNCERTAINTY TOWARD THE END
OF THE PERIOD ON HOW THE UPPER LEVEL PATTERN WILL EVOLVE THOUGH.
BOTH THE ECMWF AND GFS INDICATE A CUT OFF LOW WILL BE IN PLACE
OVER THE DESERT SOUTHWEST BUT DIFFER WITH THE NORTHERN STREAM
FLOW. THE ECMWF SUGGESTS A TROUGH WILL BE MOVING OFF THE CANADIAN
ROCKIES NORTH OF THE CUT OFF LOW INTO THE UPPER MIDWEST FOR SUNDAY
WHILE THE GFS HAS THIS TROUGH BACK ON THE CANADIAN WEST COAST.
THIS RESULTS IN THE ECMWF SHOWING A CHANCE FOR RAIN WITH THE GFS
BEING DRY. WITH SO MUCH UNCERTAINTY ON HOW THE PATTERN WILL
EVOLVE...WILL MAINTAIN A SMALL CHANCE OF RAIN FOR SATURDAY NIGHT
AND SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1258 PM CDT MON MAY 19 2014
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL MOVE ACROSS THE
AREA THROUGH MID AFTERNOON. GIVEN THE ISOLATED NATURE OF THE
THUNDERSTORMS DECIDED TO KEEP THEM OUT OF THE TAFS AT THIS TIME.
GUSTY SOUTH/SOUTHEAST WINDS OF 16 TO 20 KTS WILL OCCUR THIS
AFTERNOON WITH SOME GUSTS APPROACHING 32 KTS AT KRST. MVFR
CEILINGS ARE EXPECTED THIS AFTERNOON WITH CLOUD BASES IN THE 1500
FT TO 3000 FT RANGE. A CHALLENGING FORECAST TONIGHT DETERMINING
LOW LEVEL MOISTURE AND THE POTENTIAL FOR IFR CONDITIONS. WITH THE
LOW LEVEL MOISTURE IN PLACE OVER THE REGION AND THE GRADIENT
WEAKENING FOR A BRIEF PERIOD TONIGHT...EXPECTING A 2 TO 3 HOUR
PERIOD OF IFR CONDITIONS AT BOTH TAF SITES WITH CEILINGS LOWERING
INTO THE 700 TO 900 FT RANGE. NAM AND GFS FORECAST GUIDANCE IS
SUGGESTING THE POTENTIAL FOR FOG TONIGHT BUT DIDN/T BUY INTO THOSE
SOLUTIONS WITH THE WEAK GRADIENT IN PLACE AND THE POTENTIAL FOR
SOME MIXING AT THE SURFACE. ALSO...THE GFS AND NAM HAVE BEEN A
LITTLE AGGRESSIVE ON LOW LEVEL MOISTURE. THE BOUNDARY IS EXPECTED
TO SLIDE SOUTHEAST OF THE TAF SITES TUESDAY MORNING WITH WINDS
SWITCHING TO THE WEST/NORTHWEST BRINGING IN A SLIGHTLY DRIER
AIRMASS. VFR CONDITIONS SHOULD RETURN BY MID MORNING ON TUESDAY.
&&
.HYDROLOGY...
ISSUED AT 331 AM CDT MON MAY 19 2014
WATER LEVELS ON THE MISSISSIPPI ARE BEGINNING TO GO DOWN WITH SOME
LOCATIONS FALLING BELOW FLOOD STAGE FROM LA CROSSE AND NORTH.
MINOR FLOODING WILL CONTINUE UNTIL LATE IN THE WEEK FOR SITES
SOUTH OF LA CROSSE WHERE THE CREST IS JUST NOW ARRIVING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM....04
AVIATION...WETENKAMP
HYDROLOGY....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
647 AM CDT MON MAY 19 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 331 AM CDT MON MAY 19 2014
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH TUESDAY.
LOCAL RADAR SHOWING A FEW RETURNS OVER NORTHEAST IOWA EARLY THIS
MORNING THAT ARE MOVING EAST IN THE INITIAL BAND OF WARM AIR
ADVECTION AHEAD OF THE STORM SYSTEM OVER THE WESTERN DAKOTAS. THE
19.05Z HRRR SHOWS THESE SHOWERS TO CONTINUE MOVING EAST AND SLOWLY
DISSIPATING AS THEY MOVE OUT OF THE WARM AIR ADVECTION ZONE AND
INTO DRIER AIR AND THAT BY 12Z...WHAT REMAINS OF THEM SHOULD BE
OUT OF THE FORECAST AREA. THIS ALLOWS THE ATTENTION AND RAIN
CHANCES TO BE TIED TO THE SYSTEM COMING IN FROM THE WEST. THE
UPPER LEVEL RIDGE AXIS CURRENTLY OVER THE REGION WILL SLIDE TO THE
EAST TODAY ALLOWING A SOUTHWEST FLOW ALOFT TO DEVELOP. SEVERAL
SHORT WAVE TROUGHS ARE EMBEDDED IN THIS FLOW...BUT SOME
UNCERTAINTY ON HOW STRONG THESE WAVES WILL BE. GOOD CONSENSUS
AMONG THE MODELS THAT THE MAIN SHORT WAVE TROUGH IS CURRENTLY
MOVING ACROSS EASTERN MONTANA AND SHOULD TRACK ACROSS NORTHERN
MINNESOTA AND SOUTHERN CANADA TODAY. THE DIFFERENCES BETWEEN THE
MODELS COME WITH THE WEAKER SHORT WAVE TROUGH CURRENTLY FIRING
SOME CONVECTION OVER SOUTHERN SOUTH DAKOTA AND NEBRASKA. THE
19.00Z NAM AND GFS INTENSIFY THIS WAVE AS IT COMES EAST...ALMOST
APPEARING AS BOTH MODELS ARE SUFFERING SOME CONVECTIVE FEEDBACK
WITH IT. THE 19.00Z ECMWF AND GEM DO NOT SHOW THIS INTENSIFICATION
AND KEEP THE WAVE PRETTY WEAK AS IT SLIDES ACROSS THE AREA. THIS
WILL HAVE A BIG IMPACT ON HOW MUCH ACTIVITY CAN FORM ACROSS THE
AREA. WITH THE MORE NORTHERN WAVE BEING THE DOMINANT SYSTEM...ALL
THE MODELS SHOW THE LOW LEVEL MOISTURE TRANSPORT IS FOCUS AHEAD OF
THIS WAVE TAKING IT THROUGH THE AREA. HOWEVER...THERE IS A PERIOD
DURING THE MORNING INTO THE AFTERNOON WHERE THE AREA WILL BE ON
THE EASTERN AND CONVERGENT SIDE OF THIS MOISTURE TRANSPORT. THIS
MOISTURE TRANSPORT COMBINED WITH 2 TO 3 UBAR/S OF UP GLIDE ON THE
300K ISENTROPIC SURFACE AND THE LIFT FROM THE WAVE SHOULD BE
ENOUGH TO GENERATE SHOWERS. THE LIFT MAY BE A LITTLE BETTER ACROSS
THE NORTH CLOSER TO THE STRONGER SHORT WAVE TROUGH SO WILL
CONTINUE TO SHOW THE HIGHEST RAIN CHANCES ACROSS THE NORTH WITH 80
PERCENT TAPERING DOWN TO THE 30 TO 40 PERCENT RANGE ACROSS THE
SOUTH. NOT A WHOLE OF INSTABILITY IS EXPECTED TO BE IN PLACE TODAY
WITH THE NAM SHOWING AT MOST AROUND 500 J/KG OF MU CAPE ACROSS THE
FAR WEST DURING THE LATE AFTERNOON.
ANOTHER SHORT WAVE TROUGH IS EXPECTED TO COME ACROSS THE UPPER
MIDWEST THIS EVENING WITH THE SOUTHWEST FLOW ALOFT STILL IN PLACE.
THE MOISTURE TRANSPORT IS EXPECTED TO REMAIN THROUGH THE AREA INTO
THE NORTHERN SHORT WAVE TROUGH AS IT MOVES ACROSS SOUTHERN
ONTARIO. HOWEVER...ANOTHER ROUND OF ISENTROPIC UP GLIDE SHOULD
DEVELOP ACROSS THE AREA WITH THE NAM SHOWING THIS TO BE ON THE
ORDER OF 2 TO 4 UBAR/S ON THE 300K ISENTROPIC SURFACE. THIS UP
GLIDE WITH THE SHORT WAVE TROUGH SHOULD BE ENOUGH TO KEEP THE
SHOWERS GOING INTO THE EVENING BEFORE EVERYTHING SHIFTS OFF TO THE
EAST DURING THE OVERNIGHT HOURS. PLAN TO CONTINUE WITH THE 80
PERCENT CHANCES ACROSS THE NORTH TAPERING OFF TO 30 TO 40 PERCENT
ACROSS THE SOUTH.
THE SURFACE BOUNDARY IS THEN EXPECTED TO COME THROUGH EARLY
TUESDAY MORNING AND THEN IT SHOULD STALL EITHER ACROSS THE FAR
SOUTHERN PARTS OF THE AREA DURING THE AFTERNOON OR JUST TO THE
SOUTH OF THE AREA. GOOD CAPE IS EXPECTED TO DEVELOP NEAR THIS
BOUNDARY WITH AROUND 1500 J/KG OF ML CAPE SHOWN BY THE NAM ALONG
WITH 40 TO 50 KNOTS OF 0-6 KM SHEAR. HOWEVER...THERE DOES NOT LOOK
TO BE A GOOD TRIGGER TO SPARK DEVELOPMENT. UPPER LEVEL HEIGHTS
SHOULD BE BUILDING OVER THE AREA AND ONLY THE NAM SHOWS A WEAK
SHORT WAVE TROUGH COMING ACROSS. WITH MOST THE MODELS TRYING TO
SHOW SOME ACTIVITY ALONG THE FRONT...WILL CONTINUE TO HONOR THIS
WITH SOME 20 TO 30 PERCENT CHANCES ACROSS THE SOUTH...BUT
CONFIDENCE IS NOT HIGH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 331 AM CDT MON MAY 19 2014
ONCE THE UPPER LEVEL RIDGE BEGINS TO BUILD BACK OVER THE
REGION...THE MEDIUM RANGE MODELS INDICATE IT WILL REMAIN OVER THE
UPPER MIDWEST THROUGH THE PERIOD. SOME UNCERTAINTY TOWARD THE END
OF THE PERIOD ON HOW THE UPPER LEVEL PATTERN WILL EVOLVE THOUGH.
BOTH THE ECMWF AND GFS INDICATE A CUT OFF LOW WILL BE IN PLACE
OVER THE DESERT SOUTHWEST BUT DIFFER WITH THE NORTHERN STREAM
FLOW. THE ECMWF SUGGESTS A TROUGH WILL BE MOVING OFF THE CANADIAN
ROCKIES NORTH OF THE CUT OFF LOW INTO THE UPPER MIDWEST FOR SUNDAY
WHILE THE GFS HAS THIS TROUGH BACK ON THE CANADIAN WEST COAST.
THIS RESULTS IN THE ECMWF SHOWING A CHANCE FOR RAIN WITH THE GFS
BEING DRY. WITH SO MUCH UNCERTAINTY ON HOW THE PATTERN WILL
EVOLVE...WILL MAINTAIN A SMALL CHANCE OF RAIN FOR SATURDAY NIGHT
AND SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY NIGHT)
ISSUED AT 647 AM CDT MON MAY 19 2014
MOISTURE AND LIFT WILL CONTINUE TO INCREASE ACROSS THE AREA TODAY
WITH BRUNT OF THIS MOVING ACROSS DURING THE LATE MORNING TO MID
AFTERNOON HOURS. HOWEVER INSTABILITY IS PROGGED TO REMAIN LIMITED
UNTIL VERY LATE IN THE DAY OR THIS EVENING. THUS WITH THE FIRST
EXPECTED ROUND OF RAIN ONLY CARRIED -SHRA IN THE TAFS WITH VFR CIGS/
VSBYS...THOUGH CANNOT RULE OUT SOME MVFR VSBYS IN ANY HEAVIER SHRA
OR ISOLATED TSRA. GRADIENT WILL TIGHTEN ACROSS THE AREA TODAY AS LOW
PRESSURE MOVES EAST ACROSS THE DAKOTAS...WITH SOUTH-SOUTHEAST WINDS
15-20KT G20-30KTS DURING THE LATE MORNING/AFTERNOON HOURS.
GRADIENT RELAXES THIS EVENING WITH THE APPROACH OF THE DAKOTAS LOW.
INSTABILITY INCREASES ACROSS THE AREA AS MORE MOISTURE IN THE SFC-
850MB LAYER ARRIVES. CIGS EXPECTED TO LOWER THIS EVENING BUT REMAIN
VFR. CONFIDENCE IN CONVECTION FROM MID TO LATE EVENING INTO THE
OVERNIGHT HOURS NOT AS HIGH AS ONE WOULD LIKE. THUS ONLY CARRIED
VCTS/CB IN THE 04-09Z PERIOD AS THE LOW APPROACHES. WITH THE LIGHTER
GRADIENT AND THE LOW/BROAD SFC TROUGH OVER THE AREA LATE TONIGHT AND
RAINS AT SOME POINT TODAY OR OVERNIGHT TONIGHT...CIGS BY LATE
TONIGHT EXPECTED TO DROP INTO THE 2K-3K FT RANGE.
&&
.HYDROLOGY...
ISSUED AT 331 AM CDT MON MAY 19 2014
WATER LEVELS ON THE MISSISSIPPI ARE BEGINNING TO GO DOWN WITH SOME
LOCATIONS FALLING BELOW FLOOD STAGE FROM LA CROSSE AND NORTH.
MINOR FLOODING WILL CONTINUE UNTIL LATE IN THE WEEK FOR SITES
SOUTH OF LA CROSSE WHERE THE CREST IS JUST NOW ARRIVING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM....04
AVIATION.....HALBACH
HYDROLOGY....04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
332 AM CDT MON MAY 19 2014
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 331 AM CDT MON MAY 19 2014
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES THROUGH TUESDAY.
LOCAL RADAR SHOWING A FEW RETURNS OVER NORTHEAST IOWA EARLY THIS
MORNING THAT ARE MOVING EAST IN THE INITIAL BAND OF WARM AIR
ADVECTION AHEAD OF THE STORM SYSTEM OVER THE WESTERN DAKOTAS. THE
19.05Z HRRR SHOWS THESE SHOWERS TO CONTINUE MOVING EAST AND SLOWLY
DISSIPATING AS THEY MOVE OUT OF THE WARM AIR ADVECTION ZONE AND
INTO DRIER AIR AND THAT BY 12Z...WHAT REMAINS OF THEM SHOULD BE
OUT OF THE FORECAST AREA. THIS ALLOWS THE ATTENTION AND RAIN
CHANCES TO BE TIED TO THE SYSTEM COMING IN FROM THE WEST. THE
UPPER LEVEL RIDGE AXIS CURRENTLY OVER THE REGION WILL SLIDE TO THE
EAST TODAY ALLOWING A SOUTHWEST FLOW ALOFT TO DEVELOP. SEVERAL
SHORT WAVE TROUGHS ARE EMBEDDED IN THIS FLOW...BUT SOME
UNCERTAINTY ON HOW STRONG THESE WAVES WILL BE. GOOD CONSENSUS
AMONG THE MODELS THAT THE MAIN SHORT WAVE TROUGH IS CURRENTLY
MOVING ACROSS EASTERN MONTANA AND SHOULD TRACK ACROSS NORTHERN
MINNESOTA AND SOUTHERN CANADA TODAY. THE DIFFERENCES BETWEEN THE
MODELS COME WITH THE WEAKER SHORT WAVE TROUGH CURRENTLY FIRING
SOME CONVECTION OVER SOUTHERN SOUTH DAKOTA AND NEBRASKA. THE
19.00Z NAM AND GFS INTENSIFY THIS WAVE AS IT COMES EAST...ALMOST
APPEARING AS BOTH MODELS ARE SUFFERING SOME CONVECTIVE FEEDBACK
WITH IT. THE 19.00Z ECMWF AND GEM DO NOT SHOW THIS INTENSIFICATION
AND KEEP THE WAVE PRETTY WEAK AS IT SLIDES ACROSS THE AREA. THIS
WILL HAVE A BIG IMPACT ON HOW MUCH ACTIVITY CAN FORM ACROSS THE
AREA. WITH THE MORE NORTHERN WAVE BEING THE DOMINANT SYSTEM...ALL
THE MODELS SHOW THE LOW LEVEL MOISTURE TRANSPORT IS FOCUS AHEAD OF
THIS WAVE TAKING IT THROUGH THE AREA. HOWEVER...THERE IS A PERIOD
DURING THE MORNING INTO THE AFTERNOON WHERE THE AREA WILL BE ON
THE EASTERN AND CONVERGENT SIDE OF THIS MOISTURE TRANSPORT. THIS
MOISTURE TRANSPORT COMBINED WITH 2 TO 3 UBAR/S OF UP GLIDE ON THE
300K ISENTROPIC SURFACE AND THE LIFT FROM THE WAVE SHOULD BE
ENOUGH TO GENERATE SHOWERS. THE LIFT MAY BE A LITTLE BETTER ACROSS
THE NORTH CLOSER TO THE STRONGER SHORT WAVE TROUGH SO WILL
CONTINUE TO SHOW THE HIGHEST RAIN CHANCES ACROSS THE NORTH WITH 80
PERCENT TAPERING DOWN TO THE 30 TO 40 PERCENT RANGE ACROSS THE
SOUTH. NOT A WHOLE OF INSTABILITY IS EXPECTED TO BE IN PLACE TODAY
WITH THE NAM SHOWING AT MOST AROUND 500 J/KG OF MU CAPE ACROSS THE
FAR WEST DURING THE LATE AFTERNOON.
ANOTHER SHORT WAVE TROUGH IS EXPECTED TO COME ACROSS THE UPPER
MIDWEST THIS EVENING WITH THE SOUTHWEST FLOW ALOFT STILL IN PLACE.
THE MOISTURE TRANSPORT IS EXPECTED TO REMAIN THROUGH THE AREA INTO
THE NORTHERN SHORT WAVE TROUGH AS IT MOVES ACROSS SOUTHERN
ONTARIO. HOWEVER...ANOTHER ROUND OF ISENTROPIC UP GLIDE SHOULD
DEVELOP ACROSS THE AREA WITH THE NAM SHOWING THIS TO BE ON THE
ORDER OF 2 TO 4 UBAR/S ON THE 300K ISENTROPIC SURFACE. THIS UP
GLIDE WITH THE SHORT WAVE TROUGH SHOULD BE ENOUGH TO KEEP THE
SHOWERS GOING INTO THE EVENING BEFORE EVERYTHING SHIFTS OFF TO THE
EAST DURING THE OVERNIGHT HOURS. PLAN TO CONTINUE WITH THE 80
PERCENT CHANCES ACROSS THE NORTH TAPERING OFF TO 30 TO 40 PERCENT
ACROSS THE SOUTH.
THE SURFACE BOUNDARY IS THEN EXPECTED TO COME THROUGH EARLY
TUESDAY MORNING AND THEN IT SHOULD STALL EITHER ACROSS THE FAR
SOUTHERN PARTS OF THE AREA DURING THE AFTERNOON OR JUST TO THE
SOUTH OF THE AREA. GOOD CAPE IS EXPECTED TO DEVELOP NEAR THIS
BOUNDARY WITH AROUND 1500 J/KG OF ML CAPE SHOWN BY THE NAM ALONG
WITH 40 TO 50 KNOTS OF 0-6 KM SHEAR. HOWEVER...THERE DOES NOT LOOK
TO BE A GOOD TRIGGER TO SPARK DEVELOPMENT. UPPER LEVEL HEIGHTS
SHOULD BE BUILDING OVER THE AREA AND ONLY THE NAM SHOWS A WEAK
SHORT WAVE TROUGH COMING ACROSS. WITH MOST THE MODELS TRYING TO
SHOW SOME ACTIVITY ALONG THE FRONT...WILL CONTINUE TO HONOR THIS
WITH SOME 20 TO 30 PERCENT CHANCES ACROSS THE SOUTH...BUT
CONFIDENCE IS NOT HIGH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 331 AM CDT MON MAY 19 2014
ONCE THE UPPER LEVEL RIDGE BEGINS TO BUILD BACK OVER THE
REGION...THE MEDIUM RANGE MODELS INDICATE IT WILL REMAIN OVER THE
UPPER MIDWEST THROUGH THE PERIOD. SOME UNCERTAINTY TOWARD THE END
OF THE PERIOD ON HOW THE UPPER LEVEL PATTERN WILL EVOLVE THOUGH.
BOTH THE ECMWF AND GFS INDICATE A CUT OFF LOW WILL BE IN PLACE
OVER THE DESERT SOUTHWEST BUT DIFFER WITH THE NORTHERN STREAM
FLOW. THE ECMWF SUGGESTS A TROUGH WILL BE MOVING OFF THE CANADIAN
ROCKIES NORTH OF THE CUT OFF LOW INTO THE UPPER MIDWEST FOR SUNDAY
WHILE THE GFS HAS THIS TROUGH BACK ON THE CANADIAN WEST COAST.
THIS RESULTS IN THE ECMWF SHOWING A CHANCE FOR RAIN WITH THE GFS
BEING DRY. WITH SO MUCH UNCERTAINTY ON HOW THE PATTERN WILL
EVOLVE...WILL MAINTAIN A SMALL CHANCE OF RAIN FOR SATURDAY NIGHT
AND SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1144 PM CDT SUN MAY 18 2014
AN INITIAL BATCH OF LIGHT RAIN SHOWERS ARE MOVING EAST ACROSS
SOUTHERN MINNESOTA AND NORTH CENTRAL IOWA. A FEW OF THESE SHOWERS
ARE MAKING IT TO THE GROUND THOUGH CONDITIONS ARE STAYING VFR DUE
TO THE DRY LOW LEVEL CONDITIONS IN PLACE ACROSS THE REGION. THE
QUESTION WILL BE WITH WHETHER ANY SHOWERS AND THUNDERSTORMS ARE
ABLE TO FORM LATER TODAY AS A SYSTEM MOVES CLOSER TO THE REGION.
THE MAIN PERIOD FOR SHOWERS AND STORMS APPEARS TO BE IN THE LATE
MORNING/EARLY AFTERNOON PERIOD THOUGH SOME CHANCES WILL LINGER
INTO THE EVENING. CONDITIONS STILL LOOK LIKE THEY SHOULD MAINLY BE
VFR THOUGH...WITH GUSTY SOUTH TO SOUTHEAST WINDS THROUGH THE DAY.
&&
.HYDROLOGY...
ISSUED AT 331 AM CDT MON MAY 19 2014
WATER LEVELS ON THE MISSISSIPPI ARE BEGINNING TO GO DOWN WITH SOME
LOCATIONS FALLING BELOW FLOOD STAGE FROM LA CROSSE AND NORTH.
MINOR FLOODING WILL CONTINUE UNTIL LATE IN THE WEEK FOR SITES
SOUTH OF LA CROSSE WHERE THE CREST IS JUST NOW ARRIVING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
HYDROLOGY...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1144 PM CDT SUN MAY 18 2014
.UPDATE...
ISSUED AT 930 PM CDT SUN MAY 18 2014
MAIN UPDATE TO THE FORECAST IS WITH THE TIMING OF THE FIRST WAVE
OF RAIN SHOWERS THAT ARE CURRENTLY TRACKING EAST ACROSS SOUTHERN
MINNESOTA AND NORTHERN IOWA. MOST OF THESE RADAR RETURNS ARE JUST
VIRGA...BUT SOME OF IT HAS BEEN REACHING THE GROUND AS A FEW
OBSERVATION SITES HAVE REPORTED SOME LIGHT RAIN. ONE CELL IN
NORTHERN IOWA IS EVEN SHOWN A FEW LIGHTNING STRIKES DESPITE 0-3KM
MUCAPE SHOWING UP AS LESS THAN 100 J/KG ON THE 19.01 RAP ANALYSIS.
WILL CONTINUE WITH ANOTHER ROUND OF UPDATES WITH BRINGING THE RAIN
SHOWERS IN EARLIER OVERNIGHT.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 200 PM CDT SUN MAY 18 2014
UPPER LEVEL SHORTWAVE TROUGH IS SLATED TO LIFT ACROSS THE ROCKIES
AND OVER THE NORTHERN PLAINS MONDAY AFTERNOON. MOST OF THE UPPER
LEVEL FORCING WITH THIS FEATURE WILL HOLD ACROSS THE PLAINS/SOUTHERN
CANADA...BUT THERE IS A STRONG SURGE OF 925-700 MB WARM AIR
ADVECTION AHEAD OF IT...MAXED ACROSS THE UPPER MISSISSIPPI RIVER
VALLEY BETWEEN 18-06Z MON. SOME SLOPING FRONTOGENETIC
RESPONSE...ASSOCIATED WITH A WARM FRONT...AND SOME HELP FROM A 300
MB JET STREAK. DECENT PUSH OF 850 MB MOISTURE TRANSPORT ACCOMPANIES
THE LOW LEVEL WARMING...WITH A 40-45 KT 850 MB JET NOSING INTO
NORTHERN WI BY 00Z TUE. NOT MUCH INSTABILITY ON MONDAY...ALL HANGING
TO THE WEST VIA THE NAM/GFS. BOTH MODELS DO SUGGEST ABOUT 500 J/KG
MUCAPE FOR MONDAY EVENING...ALTHOUGH THE BETTER PCPN CHANCES MAY
HAVE SHIFTED TO NORTHERN WI BY THIS TIME. 0-6KM SHEAR GOOD AT 40+
KTS...BUT WITH LITTLE/IF ANY INSTABILITY TO PLAY WITH...DON/T SEE AN
ORGANIZED SEVERE THREAT AT THIS TIME.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 200 PM CDT SUN MAY 18 2014
THE GFS/ECMWF BOTH AGREE THAT THE UPPER LEVEL FLOW BECOMES MORE
ZONAL BY MID WEEK...POINTING TO RIDGING BY NEXT WEEKEND. AT THE
SFC...HIGH PRESSURE BUILDS IN THU NIGHT...EASING OVER THE OH RIVER
VALLEY ON SUNDAY. TEMPERATURES WILL WARM INTO THE WEEKEND...REACHING
OR EXCEEDING THE LATE MAY NORMALS - LOW 70S. SHOULD BE A RAIN-FREE
PERIOD...ALTHOUGH SOME POTENTIAL MOVING INTO SUNDAY AS RETURN
FLOW/WARM AIR ADVECTION COULD SPARK A FEW SHOWERS/STORMS TO THE
WEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1144 PM CDT SUN MAY 18 2014
AN INITIAL BATCH OF LIGHT RAIN SHOWERS ARE MOVING EAST ACROSS
SOUTHERN MINNESOTA AND NORTH CENTRAL IOWA. A FEW OF THESE SHOWERS
ARE MAKING IT TO THE GROUND THOUGH CONDITIONS ARE STAYING VFR DUE
TO THE DRY LOW LEVEL CONDITIONS IN PLACE ACROSS THE REGION. THE
QUESTION WILL BE WITH WHETHER ANY SHOWERS AND THUNDERSTORMS ARE
ABLE TO FORM LATER TODAY AS A SYSTEM MOVES CLOSER TO THE REGION.
THE MAIN PERIOD FOR SHOWERS AND STORMS APPEARS TO BE IN THE LATE
MORNING/EARLY AFTERNOON PERIOD THOUGH SOME CHANCES WILL LINGER
INTO THE EVENING. CONDITIONS STILL LOOK LIKE THEY SHOULD MAINLY BE
VFR THOUGH...WITH GUSTY SOUTH TO SOUTHEAST WINDS THROUGH THE DAY.
&&
.HYDROLOGY...
ISSUED AT 302 AM CDT SUN MAY 18 2014
WATER LEVELS ALONG THE MISSISSIPPI RIVER WILL CONTINUE TO RUN HIGH
THROUGH THE WEEKEND INTO NEXT WEEK. SOME MINOR FLOODING IS ALREADY
OCCURRING OR EXPECTED TO OCCUR INTO NEXT WEEK.
FOR MORE DETAILED INFORMATION...LOOK ON OUR INTERNET PAGE AT
WWW.WEATHER.GOV/LACROSSE. CLICK ON THE NEWS STORY AT THE TOP OF
THE PAGE PERTAINING TO THE MISSISSIPPI RIVER.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...HALBACH
HYDROLOGY....DTJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
719 PM MDT TUE MAY 20 2014
.UPDATE...
ISSUED AT 716 PM MDT TUE MAY 20 2014
BEGAN PEELING OUR SOUTHEAST WYOMING COUNTIES OUT OF THE SEVERE
THUNDERSTORM WATCH. CONVECTION MAINLY CONFINED TO THE PANHANDLE
WITH SOME LIGHT CONVECTION OVER NORTHERN PLATTE AND GOSHEN
COUNTIES. THIS CONVECTION IN SOUTHEAST WYOMING APPEARS TO BE
WEAKENING...THEREFORE THE CANCELLATION OF THE WATCH. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 300 PM MDT TUE MAY 20 2014
FORECAST CHALLENGES CONTINUE TO BE SEVERE THUNDERSTORM CHANCES
TODAY AND WEDNESDAY.
CURRENTLY...FAIRLY QUIET RIGHT NOW EARLY THIS AFTERNOON ACROSS THE
CWFA. STARTING TO GET SOME LIGHTNING STRIKES FROM CONVECTION
DEVELOPING OVER THE LARAMIE RANGE. WOULD EXPECT THIS TO CONTINUE
TO INCREASE IN COVERAGE AND INTENSITY AS THE AFTERNOON CONTINUES.
EASTERLY TO SOUTHEASTERLY SURFACE WINDS ACROSS EASTERN PORTIONS OF
THE CWFA WITH PRETTY GOOD DEWPOINTS. GETTING UPPER 40S OUT BY
CHADRON...47 HERE AT CHEYENNE AND 43 UP BY DOUGLAS. TEMPERATURES
IN THE MID 60S JUST ABOUT EVERYWHERE EAST OF THE LARAMIE RANGE.
LATEST SPC MESOANALYSIS SHOWING SURFACE BASED CAPES AROUND 1000
J/KG ALONG THE LARAMIE RANGE WITH NO CONVECTIVE INHIBITION
ANALYZED AT THIS TIME. LIFTED INDICES NEAR ZERO JUST ABOUT
EVERYWHERE WITH -3C IN THE GENERAL LOCATION WHERE CONVECTION IS
INITIATING. LATEST WATER VAPOR IMAGERY SHOWING CLOSED LOW MOVING
INTO CENTRAL NEVADA THIS AFTERNOON.
FOR LATER THIS AFTERNOON...LOOKING AT LIFTED INDICES TO CONTINUE
FALLING TO -3 TO -4C ACROSS MUCH OF THE AREA EAST OF THE LARAMIE
RANGE BY 00Z. LATEST HRRR CONVECTIVE FORECAST KEYED INTO A
SUPERCELL DEVELOPING NEAR WHEATLAND THIS AFTERNOON...THEN TRACKING
EAST ACROSS TORRINGTON BY 23Z AND THEN INTO SOUTHERN SIOUX COUNTY
BY THE 00-01Z TIME FRAME. CONVECTION FAIRLY WIDESPREAD ACROSS THE
NORTHERN PANHANDLE AFTER 00Z. HIGH 0-6KM BULK SHEAR FORECASTS OF
60 TO 65KTS SHOULD SUPPORT VERY LARGE HAIL DEVELOPMENT WITH STORMS
THAT GET GOING THIS AFTERNOON. ONE LAST ITEM WITH THE STORMS
TODAY. FORECAST STORM MOTIONS ARE LOW...GENERALLY 10KTS OR LESS.
SO WE NEED TO WATCH FOR HEAVY RAIN/POSSIBLE LOCALIZED FLASH
FLOODING.
PRETTY MUCH A REPEAT FOR WEDNESDAY AFTERNOON. SEVERE THUNDERSTORM
POTENTIAL WILL CONTINUE FOR LOCATIONS EAST OF THE LARAMIE RANGE.
MAYBE MORE DOWN IN THE SOUTHERN PART OF THE CWFA DOWN HERE NEAR
CHEYENNE.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 300 PM MDT TUE MAY 20 2014
MEDIUM RANGE GUIDANCE IS IN EXCELLENT AGREEMENT WITH A POTENT CUTOFF
LOW OVER THE 4 CORNERS EARLY IN THE FCST PERIOD. NOT MUCH CHANGE IN
SENSIBLE WEATHER ACROSS THE REGION WITH THIS PATTERN IN PLACE...WITH
CONTINUED DAILY CHANCES FOR SHOWERS AND STORMS THROUGH THE WEEKEND
AND INTO EARLY NEXT WEEK. THIS FEATURE LIFTS NORTHEAST TOWARD THE
CENTRAL HIGH PLAINS ON SUN AND MON WITH THE ECMWF STILL ADVERTISING
DEFORMATION PRECIP BANDING ON THE BACK SIDE. POTENTIAL EXISTS FOR A
FAIRLY WIDESPREAD MODERATE RAIN EVENT DURING THIS TIME...HOWEVER THE
GFS IS NOT AS BULLISH WITH QPF AMOUNTS. WILL NEED TO WATCH CLOSELY
AS THIS WILL CAUSE HYDRO ISSUES IF THIS PCPN FALLS OVER THE SNOW
PACKED MOUNTAINS. H7 TEMPS WILL BE AROUND 8 TO 10 DEG C THROUGH THE
MAJORITY OF THE FCST PERIOD...GIVING WAY TO HIGHS BETWEEN 65 AND 75
DEGREES FOR MUCH OF THE LOWER ELEVATIONS. WESTERLY DOWNSLOPE RETURNS
ON MON...GIVING WAY TO WARMER AND DRIER CONDITIONS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY AFTERNOON)
ISSUED AT 553 PM MDT TUE MAY 20 2014
CONVECTION TO CONTINUE THROUGH SUNSET THIS EVENING. WINDS
FAVORABLE OVERNIGHT FOR SOME UPSLOPING STRATUS TO DEVELOP HERE AT
KCYS AND POSSIBLY KLAR. WENT MVFR OF CEILINGS...BUT LATER SHIFTS
MAY NEED TO LOWER FURTHER.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MDT TUE MAY 20 2014
CONCERNS TO REMAIN LOW FOR THE REST OF THE WEEK WITH CONDITIONS
AND FUELS EXPECTED TO REMAIN NON-CRITICAL. SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS WILL MOVE ACROSS MAINLY EASTERN DISTRICTS
MOST DAYS WITH VERY GOOD CHANCES FOR WETTING RAINS. A MORE
WIDESPREAD RAIN EVENT SATURDAY AFTERNOON THROUGH MONDAY MORNING
SHOULD DEVELOP ACROSS SOUTHEAST WYOMING AND NEBRASKA
PANHANDLE...SO FIRE WEATHER CONCERNS ARE MINIMAL.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLAYCOMB
SHORT TERM...CLAYCOMB
LONG TERM...HAMMER
AVIATION...CLAYCOMB
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
605 PM MDT TUE MAY 20 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 300 PM MDT TUE MAY 20 2014
FORECAST CHALLENGES CONTINUE TO BE SEVERE THUNDERSTORM CHANCES
TODAY AND WEDNESDAY.
CURRENTLY...FAIRLY QUIET RIGHT NOW EARLY THIS AFTERNOON ACROSS THE
CWFA. STARTING TO GET SOME LIGHTNING STRIKES FROM CONVECTION
DEVELOPING OVER THE LARAMIE RANGE. WOULD EXPECT THIS TO CONTINUE
TO INCREASE IN COVERAGE AND INTENSITY AS THE AFTERNOON CONTINUES.
EASTERLY TO SOUTHEASTERLY SURFACE WINDS ACROSS EASTERN PORTIONS OF
THE CWFA WITH PRETTY GOOD DEWPOINTS. GETTING UPPER 40S OUT BY
CHADRON...47 HERE AT CHEYENNE AND 43 UP BY DOUGLAS. TEMPERATURES
IN THE MID 60S JUST ABOUT EVERYWHERE EAST OF THE LARAMIE RANGE.
LATEST SPC MESOANALYSIS SHOWING SURFACE BASED CAPES AROUND 1000
J/KG ALONG THE LARAMIE RANGE WITH NO CONVECTIVE INHIBITION
ANALYZED AT THIS TIME. LIFTED INDICES NEAR ZERO JUST ABOUT
EVERYWHERE WITH -3C IN THE GENERAL LOCATION WHERE CONVECTION IS
INITIATING. LATEST WATER VAPOR IMAGERY SHOWING CLOSED LOW MOVING
INTO CENTRAL NEVADA THIS AFTERNOON.
FOR LATER THIS AFTERNOON...LOOKING AT LIFTED INDICES TO CONTINUE
FALLING TO -3 TO -4C ACROSS MUCH OF THE AREA EAST OF THE LARAMIE
RANGE BY 00Z. LATEST HRRR CONVECTIVE FORECAST KEYED INTO A
SUPERCELL DEVELOPING NEAR WHEATLAND THIS AFTERNOON...THEN TRACKING
EAST ACROSS TORRINGTON BY 23Z AND THEN INTO SOUTHERN SIOUX COUNTY
BY THE 00-01Z TIME FRAME. CONVECTION FAIRLY WIDESPREAD ACROSS THE
NORTHERN PANHANDLE AFTER 00Z. HIGH 0-6KM BULK SHEAR FORECASTS OF
60 TO 65KTS SHOULD SUPPORT VERY LARGE HAIL DEVELOPMENT WITH STORMS
THAT GET GOING THIS AFTERNOON. ONE LAST ITEM WITH THE STORMS
TODAY. FORECAST STORM MOTIONS ARE LOW...GENERALLY 10KTS OR LESS.
SO WE NEED TO WATCH FOR HEAVY RAIN/POSSIBLE LOCALIZED FLASH
FLOODING.
PRETTY MUCH A REPEAT FOR WEDNESDAY AFTERNOON. SEVERE THUNDERSTORM
POTENTIAL WILL CONTINUE FOR LOCATIONS EAST OF THE LARAMIE RANGE.
MAYBE MORE DOWN IN THE SOUTHERN PART OF THE CWFA DOWN HERE NEAR
CHEYENNE.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 300 PM MDT TUE MAY 20 2014
MEDIUM RANGE GUIDANCE IS IN EXCELLENT AGREEMENT WITH A POTENT CUTOFF
LOW OVER THE 4 CORNERS EARLY IN THE FCST PERIOD. NOT MUCH CHANGE IN
SENSIBLE WEATHER ACROSS THE REGION WITH THIS PATTERN IN PLACE...WITH
CONTINUED DAILY CHANCES FOR SHOWERS AND STORMS THROUGH THE WEEKEND
AND INTO EARLY NEXT WEEK. THIS FEATURE LIFTS NORTHEAST TOWARD THE
CENTRAL HIGH PLAINS ON SUN AND MON WITH THE ECMWF STILL ADVERTISING
DEFORMATION PRECIP BANDING ON THE BACK SIDE. POTENTIAL EXISTS FOR A
FAIRLY WIDESPREAD MODERATE RAIN EVENT DURING THIS TIME...HOWEVER THE
GFS IS NOT AS BULLISH WITH QPF AMOUNTS. WILL NEED TO WATCH CLOSELY
AS THIS WILL CAUSE HYDRO ISSUES IF THIS PCPN FALLS OVER THE SNOW
PACKED MOUNTAINS. H7 TEMPS WILL BE AROUND 8 TO 10 DEG C THROUGH THE
MAJORITY OF THE FCST PERIOD...GIVING WAY TO HIGHS BETWEEN 65 AND 75
DEGREES FOR MUCH OF THE LOWER ELEVATIONS. WESTERLY DOWNSLOPE RETURNS
ON MON...GIVING WAY TO WARMER AND DRIER CONDITIONS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY AFTERNOON)
ISSUED AT 553 PM MDT TUE MAY 20 2014
CONVECTION TO CONTINUE THROUGH SUNSET THIS EVENING. WINDS
FAVORABLE OVERNIGHT FOR SOME UPSLOPING STRATUS TO DEVELOP HERE AT
KCYS AND POSSIBLY KLAR. WENT MVFR OF CEILINGS...BUT LATER SHIFTS
MAY NEED TO LOWER FURTHER.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MDT TUE MAY 20 2014
CONCERNS TO REMAIN LOW FOR THE REST OF THE WEEK WITH CONDITIONS
AND FUELS EXPECTED TO REMAIN NON-CRITICAL. SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS WILL MOVE ACROSS MAINLY EASTERN DISTRICTS
MOST DAYS WITH VERY GOOD CHANCES FOR WETTING RAINS. A MORE
WIDESPREAD RAIN EVENT SATURDAY AFTERNOON THROUGH MONDAY MORNING
SHOULD DEVELOP ACROSS SOUTHEAST WYOMING AND NEBRASKA
PANHANDLE...SO FIRE WEATHER CONCERNS ARE MINIMAL.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLAYCOMB
LONG TERM...HAMMER
AVIATION...CLAYCOMB
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
403 AM EDT Wed May 21 2014
.Near Term [Through Today]...
After keeping an eye out for some potential dense fog across SE AL
and western portions of the FL Panhandle this morning, a mostly
sunny, hot, and fairly dry day is expected across the region this
afternoon, with just a possible shallow CU field along the sea
breeze front. High temps should range from the middle 80s along the
coast to the lower 90s over much of the interior, with even hotter
weather on tap for the end of the week.
.Short Term [Tonight Through Friday]...
A deep and vertically-stacked ridge will be situated basically
right on top of our forecast area for the end of the work week
(Thursday and Friday). In fact, the 500mb heights will build close
to 5900m which is around 1.5 standard deviations above normal.
850mb temperatures are also forecast to increase into the +19C
range, which is close to 2 standard deviations above normal and
right around the 99th percentile for May for Tallahassee. This
creates high confidence in above-normal temperatures for both
days, and it seems likely that model guidance is underestimating
potential highs. Other factors favoring hot weather include the
surface-850mb ridge axis being positioned just west of our area,
setting up northwesterly low-level flow which could suppress the
inland progression of the sea breeze. Additionally, the column
should be fairly dry (and thus limited to no cloud cover is
expected) with 1000-500mb deep layer RH less than 40%. For
Thursday, model guidance is more tightly clustered in the lower
90s, whereas a couple rule-of-thumb charts based on 850mb temps
suggest mid 90s are likely with a few upper 90s not out of the
question. The latest forecast calls for widespread mid-90s on
Thursday, which is warmer than guidance. However, it`s not
inconceivable that a few upper 90s could occur. Thursday should
see fairly deep mixing, and given the dry column the surface RH
and dewpoints should be relatively low. For Friday, there may be a
little more humidity. Guidance is warmer overall - in the mid 90s
- and that is also what our forecast calls for.
.Long Term [Friday Night Through Wednesday]...
The long term period will be hot and for the most part dry as deep
layer ridging will park itself over our CWA. Late in the weekend a
weak frontal boundary will position itself over our CWA. With the
frontal boundary combined with the inland progression of the sea
breeze, there may be potential for some isolated thunderstorms to
develop in the afternoon and early evening. Therefore maintained a
20-25% PoP from Sunday afternoon through the end of the period with
the greatest chance of a thunderstorm being generally north of the
Florida border.
&&
.Aviation...
[Through 06Z Thursday] Fairly tricky fog fcst across the terminals
tonight with the potential for a repeat of IFR/LIFR conditions at
ECP. Though most of the guidance is very skeptical, the HRRR and
developing Satellite imagery are not, and am also a bit concerned
for some dense fog approaching DHN before the overnight hours are
through. Also expect some minor MVFR level conditions at TLH and VLD
for a short period. Any fog should burn off rapidly during the day
today, with VFR conditions quickly returning.
&&
.Marine...
Winds should be less than 15 knots with seas 2 feet or less
through the weekend, with no rain or thunderstorms expected.
Locally stronger and gusty winds are possible near the coast each
afternoon due to the sea breeze. It`s possible we may have more
active rip currents along the Walton, Bay, and Gulf County beaches
on Thursday and Friday with gusty onshore flow, surf heights as
high as 2 feet, and a longer fetch of westerly flow over the far
northern Gulf of Mexico.
&&
.Fire Weather...
Although afternoon relative humidities will be very low across much
of the interior on Thursday, no other criteria will be met to cause
any Red Flag concerns.
&&
.Hydrology...
Only one area river is currently in minor flood, the Steinhatchee.
The Choctawhatchee at Bruce is forecast to reach minor flood stage
late Tonight, cresting just above flood at 13.2 feet. Little or
no rainfall is expected through next weekend.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 91 63 96 65 95 / 0 0 0 0 0
Panama City 87 68 90 70 89 / 0 0 0 0 0
Dothan 91 65 93 67 94 / 0 0 0 0 0
Albany 91 65 94 67 94 / 0 0 0 0 0
Valdosta 93 65 97 66 97 / 0 0 0 0 0
Cross City 90 62 93 65 93 / 0 0 0 0 0
Apalachicola 83 67 89 70 89 / 0 0 0 0 0
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...GOULD
SHORT TERM...LAMERS
LONG TERM...BARRY/NAVARRO
AVIATION...GOULD
MARINE...LAMERS
FIRE WEATHER...GOULD
HYDROLOGY...BLOCK/GODSEY
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
132 AM EDT WED MAY 21 2014
.SYNOPSIS...
ISSUED AT 343 PM EDT TUE MAY 20 2014
A COLD FRONT WILL SLOWLY SLIP SOUTH INTO THE REGION OVER THE NEXT
24 HOURS. SHOWERS AND THUNDERSTORMS ARE EXPECTED
TONIGHT...ESPECIALLY ACROSS PORTIONS OF LOWER MICHIGAN...NORTHERN
INDIANA AND NORTHWESTERN OHIO WITH SEVERE WEATHER A POSSIBILITY.
THE COLD FRONT WILL MOVE THROUGH ON WEDNESDAY WITH ADDITIONAL
CHANCES OF SHOWERS AND THUNDERSTORMS. LOWS TONIGHT WILL DROP INTO
THE 60S WITH HIGHS WEDNESDAY GENERALLY IN THE LOWER 80S...WITH
LOCALLY COOLER CONDITIONS ALONG THE LAKE.
&&
.UPDATE...
ISSUED AT 750 PM EDT TUE MAY 20 2014
CONVECTION HAS RAPIDLY DEVELOPED THIS EVENING ACROSS IN VICINITY
OF LOW LEVEL TROUGH AXIS FROM EASTERN IOWA INTO FAR SOUTHERN
WISCONSIN. A SECONDARY AREA OF WEAK PREFRONTAL CONVERGENCE HAS
ALSO LED TO A SECONDARY BROKEN LINE OF THUNDERSTORMS ACROSS
NORTHERN ILLINOIS. MODERATE INSTABILITY DEPICTED PER 23Z RAP
ANALYSIS FROM NORTHERN ILLINOIS INTO FAR NORTHERN INDIANA/SOUTHERN
LOWER MICHIGAN WITH 100 HPA MLCAPES ON THE ORDER OF 1500-2000
J/KG. AS OF 23Z...STRONGEST DEEP LAYER SHEAR RESIDES NORTH AND
WEST OF LOCAL AREA...BUT POCKET OF STRONGER UPPER LEVEL WESTERLIES
SHOULD OVERSPREAD SOUTHERN GREAT LAKES REGION OVER THE NEXT FEW
HOURS...INCREASING EFFECTIVE SHEAR ACROSS AT LEAST NORTHERN HALF
OF THE AREA. PER SPC MESODISCUSSIONS AND CONVECTIVE
OUTLOOKS...UPSCALE GROWTH STILL OF SOMEWHAT LOW CONFIDENCE GIVEN
LACK OF STRONG MID/UPPER LEVEL FORCING. HOWEVER...COMBINATION OF
MODERATE INSTABILITY AND INCREASING DEEP LAYER EFFECTIVE SHEAR
SHOULD AT LEAST SUPPORT ISOLD SEVERE RISK INTO NORTHWEST PORTIONS
OF THE AREA LATER THIS EVENING CONSIDERING ADDITIONAL OUTFLOW
INTERACTIONS WITH UPSTREAM CONVECTION. HAVE NOT MADE MANY CHANGES
TO PREVIOUS FORECAST WITH ONLY TWEAK TO SHAVE OFF POPS SOME ACROSS
SOUTHEAST HALF OF THE AREA OVER NEXT FEW HOURS. DID NOT MAKE
SUBSTANTIAL CHANGES TO POPS AFTER 03Z WITH SOME CONCERN THAT IF
UPSTREAM CONVECTION CAN CONGEAL...EASTWARD PROPAGATION WILL
ACCELERATE LATER THIS EVENING ACROSS EAST/SOUTHEAST PORTIONS OF
THE FORECAST AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 333 PM EDT TUE MAY 20 2014
...THREAT OF SEVERE WEATHER THIS EVENING...POSSIBLY INTO OVERNIGHT
HOURS...
MAIN FOCUS RESIDES ON COLD FRONT EXTENDING FROM CNTRL LK MI INTO
IOWA WHICH WILL BECOME THE TRIGGER POINT FOR THUNDERSTORMS OVER THE
NEXT COUPLE OF HOURS. CONCERNS LOOM IN EXACTLY HOW THESE STORMS WILL
EVOLVE AND DROP SE TOWARDS THE FORECAST AREA TONIGHT. SPC
MESOANALYSIS SHOWS SFC BASED CAPES 2000 TO 3000 J/KG WERE POOLING
ALONG THE FRONT WITH STEEPENING LAPSE RATES AND INCREASING SHEAR. CU
FIELD HAVE BEEN RATHER SUBDUED THUS FAR ALONG THE FRONT. HOWEVER ALL
HIGH RES MODELS SEEM TO POINT TOWARDS RAPID FORMATION OF STORMS IN
THE 21 TO 23Z TIME FRAME. INITIAL STORM MODE SHOULD BE MULTICELL
CLUSTERS/SOME SUPERCELLS WHICH WILL PRODUCE HAIL AND DAMAGING
WINDS...ALONG WITH SOME TORNADO THREAT. COLD POOL SHOULD BEGIN TO
ESTABLISH WITH CORFIDI VECTORS INDICATED A RAPID FORWARD PROPAGATION
INTO NW PARTS OF THE AREA AFTER 00Z AND OVERSPREADING AT LEAST
NORTHERN HALF THE REMAINDER OF THE EVENING. TIMING OF DAY WILL PLAY
SOMEWHAT AGAINST SEVERE POTENTIAL AS WILL FACT THAT ACTUAL COLD
FRONT WILL RESIDE WELL NW OF THE AREA UNTIL LATER TONIGHT.
HOWEVER...ALL SIGNS CONTINUE TO POINT TOWARDS INCREASING SEVERE
THREAT THIS EVENING...WARRANTING INCREASE IN POPS AND ADDITION OF
SVR WORDING. SOUTHERN EXTENT VERY QUESTIONABLE AS OUTFLOW BOUNDARIES
EVENTUALLY RACE AHEAD OF THE LINE AND ALLOW FOR POTENTIAL FOR THE
LINE TO STALL OUT WITH HRRR INDICATING SOME POTENTIAL FOR ADDITIONAL
DEVELOPMENT ACROSS ILLINOIS/IOWA MOVING IN LATER THIS EVENING. HAVE
NOT ADDED MENTION OF HVY RAIN...BUT TRAINING OF CELLS WILL BE
POSSIBLE WITH INHERENT THREAT FOR FLOODING. WILL DEFER TO EVE SHIFT
TO MONITOR TRENDS.
NO CHANGES TO FORECAST ON WEDNESDAY WITH RESIDUAL BOUNDARY FROM
OVERNIGHT CONVECTION BEING KEY IN CONVECTIVE CHANCES AS ACTUAL COLD
FRONT MOVES IN. NEW DAY2 OUTLOOK HAS SHOVED SLGT RISK A BIT FURTHER
SOUTH ACROSS MAINLY SE THIRD OF THE AREA WHICH IS REASONABLE AT THIS
STAGE. WILL DEFER TO OVERNIGHT SHIFT TO MAKE ADJUSTMENTS.
&&
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 333 PM EDT TUE MAY 20 2014
CDFNT SHOULD BE MOVG THROUGH S-SE PORTION OF CWA AT START OF THE
PERIOD WED EVE. CONVECTION WILL PRBLY HAVE MOVED OUT AHEAD OF THE
FRONT BY 00Z AND BE LOCATED S-SE OF THE CWA, BUT THERE IS A SMALL
CHC OF ACTIVITY CONTG TO DEVELOP ALONG IT, SO MAINTAINED A LOW POP
THROUGH WED EVE. COOLER/DRIER AIRMASS WILL SPREAD INTO THE AREA
BEHIND THE CDFNT BY THURSDAY. SHRTWV MOVG THROUGH THE UPR GRTLKS
TONIGHT/WED EXPECTED TO TRANSITION TO A CUT-OFF LOW OVER NERN
U.S./SE CANADA BY THU WITH ANOTHER CUT-OFF LOW LINGERING OVER THE
SWRN CONUS WHILE IN BETWEEN RIDGE OVER CENTRAL U.S. WILL PROVIDE
OUR AREA WITH FAIR WX LATE THIS WEEK. THESE SYSTEMS EXPECTED TO
MAKE SLOW E-NE PROGRESS OVER THE WEEKEND AND EARLY NEXT WEEK,
LIKELY CONTG THE DRY SPELL ACROSS OUR CWA. TEMPS THU SHOULD BE A
BIT BLO NORMAL, MODIFYING TO WELL ABOVE NORMAL OVER THE HOLIDAY
WEEKEND AS THE UPR RIDGE BUILDS INTO THE AREA. RETURN FLOW WILL
RESULT IN INCREASING LOW LEVEL MOISTURE AND SOME DEVELOPING
INSTABILITY AS SFC HIGH MOVES EAST OF THE AREA BY MONDAY, BUT
PROXIMITY OF UPR LEVEL RIDGE SUGGESTS ANY CONVECTION IN OUR AREA
WILL BE ISOLATED AT BEST, SO FOR NOW HELD OFF ADDING TO FCST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 127 AM EDT WED MAY 21 2014
RADAR AND SATELLITE TRENDS DICTATING NEAR TERM TAF PERIOD.
CONVECTIVE LINES ABOUT TO MOVE THROUGH BOTH KSBN AND KFWA. WIND
GUSTS TO 35 KNOTS POSSIBLE WITH MVFR CONDITIONS. BRIEF IFR
POSSIBLE...MAINLY FROM REDUCED VIS IN HEAVY RAINFALL. KFWA TO SEE
END TO PCPN BY 07Z BUT RADAR SHOWS SEVERAL CLUSTERS WEST OF KSBN
THAT MAY CONTINUE TO IMPACT THAT SITE THROUGH 09Z OR 10Z. MVFR
CIGS AND VIS DEVELOPMENT IN COOL AND MOIST BOUNDARY LAYER STILL
POSSIBLE TOWARD DAYBREAK. COLD FRONT SAGS SOUTH THIS AFTERNOON
WITH SOME LOW END CONVECTIVE POTENTIAL CLOSER TO KFWA SO INCLUDED
A PROB30 THERE TO ACCOUNT FOR ANY DEVELOPMENT. OTHERWISE VFR.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...MARSILI
SYNOPSIS...MURPHY/FISHER
SHORT TERM...FISHER
LONG TERM...JT
AVIATION...LASHLEY
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1250 AM EDT WED MAY 21 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 344 PM EDT TUE MAY 20 2014
A FRONTAL SYSTEM WILL BRING CHANCES FOR THUNDERSTORMS TO CENTRAL
INDIANA STARTING LATE TONIGHT ACROSS THE NORTH AND SPREADING SOUTH
WEDNESDAY AS A COLD FRONT SINKS SOUTH THROUGH THE AREA. THE BEST
CHANCES FOR SEVERE STORMS WITH THIS SYSTEM WILL BE WEDNESDAY
AFTERNOON AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT
THURSDAY USHERING IN DRY WEATHER WITH IT FOR THE REMAINDER OF THE
PERIOD.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 940 PM EDT TUE MAY 20 2014
SCATTERED CONVECTION HAS BEEN OCCURRING ACROSS NORTHERN ILLINOIS
BACK INTO IOWA OVER THE PAST FEW HOURS. THIS EVENING/S UPPER AIR
INDICATES RATHER WEAK DEEP LAYER SHEAR ACROSS THE AREA...ALTHOUGH
MID LEVEL LAPSE RATES ARE VERY STEEP. SO FAR...HAVEN/T SEEN ANY
INDICATION OF A CONSOLIDATING COLD POOL FROM THE CONVECTION OFF TO
THE NORTH...ALTHOUGH SHORT TERM MODEL DATA SUGGEST A POTENTIAL
OUTFLOW MOVING INTO THE NORTHERN ZONES AFTER MIDNIGHT. STILL UNCLEAR
AS TO WHETHER CONVECTION WILL BUILD SOUTH INTO THE AREA LATER
TONIGHT. 850MB FLOW INTO THE CONVECTIVE AREA IS DECENT...BUT NOT
PARTICULARLY STRONG.
WILL KEEP CHANCE POPS GOING OVER THE NORTHERN HALF OF THE AREA
TONIGHT...BUT WILL BACK OFF ON THE TIMING UNTIL AFTER MIDNIGHT.
PREVIOUS DISCUSSION FOLLOWS.
SOME UNCERTAINTY STILL EXISTS WITH TONIGHT/S FORECAST CONCERNING HOW
FAR SOUTH STORMS WILL GET. SHORT TERM MODEL GUIDANCE WAS TRENDING
DRIER AND PUSHING THE POPS NORTH FOR SEVERAL RUNS THIS MORNING...BUT
LATEST RUNS OF RAP HAVE STARTED BRINGING ECHOES FURTHER SOUTH AND
VERY CLOSE TO THE NORTHERN COUNTIES. THE INFLUENCE OF THE UPPER
RIDGE SHOULD KEEP INITIAL FORMATION WELL NORTH OF THE FORECAST AREA
AND EXPECT CONDITIONS TO REMAIN DRY FOR A TIME AFTER 0Z. BY 6Z
HOWEVER COULD SEE STORMS STARTING TO APPROACH THE NORTHERN
COUNTIES...AND WOULD NOT BE OUT OF THE REALM OF POSSIBILITIES TO SEE
AN MCS DEVELOP AND RIDGE THE THETA E GRADIENT AROUND THE EDGE OF THE
UPPER RIDGE WHICH COULD BRING IT INTO THE NORTHERN/NORTHEASTERN
COUNTIES. NAM SEEMS TO FAVOR DEVELOPMENT A DECENT BIT FURTHER SOUTH
THAN OTHER SOLUTIONS AND GENERALLY DISCOUNTED IT. CONSIDERING THE
UNCERTAINTY AND VARIETY OF SOLUTIONS RIGHT NOW...THINK BEST COURSE
OF ACTION IS TO INCLUDE MID CHANCE POPS ALONG THE NORTHERN TO
NORTHEASTERN BORDER AND BRING A SLIGHT CHANCE DOWN ALONG THE EASTERN
BORDER AROUND 9Z THAT RUNS THROUGH 12Z TO ACCOUNT FOR THE LOW CHANCE
OF A RIGHT TURNING MCS
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 344 PM EDT TUE MAY 20 2014
FORECAST FOCUS IS ON CHANCES FOR SEVERE STORMS WEDNESDAY. CIN DROPS
OFF DURING THE DAY ON WEDNESDAY WHILE MLCAPES CLIMB TO OVER 2000
OVER MUCH OF THE FORECAST AREA BY THE AFTERNOON. THE COLD FRONT
SHOULD GET INTO THE NORTHWESTERN COUNTIES AROUND 12-15Z AND START
SINKING SOUTH THROUGH THE AREA...BUT MOVES THROUGH VERY SLOWLY.
0-6 KM BULK SHEAR INCREASES DURING THE AFTERNOON AND...ALONG WITH
THE AFOREMENTIONED INSTABILITY AND FRONTAL FORCING...SHOULD BE
SUFFICIENT TO SUPPORT AN ORGANIZED SEVERE THREAT THAT WILL BE
MAXIMIZED DURING THE 18Z WED-3Z THU TIMEFRAME.
WITH THIS SET OF MODEL RUNS THE FRONT DOES NOT MOVE AS QUICKLY AWAY
FROM THE AREA AND THUS HELD POPS INTO EARLY THURSDAY MORNING
/STILL PRIOR TO 12Z/ IN THE SOUTH. LOOKS LIKE HIGH PRESSURE WILL
BE BUILDING IN ENOUGH TO DRY OUT ALL PRECIP BY 12Z THOUGH AND THEN
WILL KEEP THE WEATHER DRY THROUGH THE SHORT TERM.
FOR TEMPERATURES GUIDANCE WAS CLOSE AND GENERALLY USED A CONSENSUS
EXCEPT FOR WEDNESDAY WHEN FAVORED WARMER MAV NUMBERS BASED ON
CONTINUED STRONG WARM ADVECTION AHEAD OF THE COLD FRONT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 237 PM EDT TUE MAY 20 2014
HOLIDAY WEEKEND LOOKS FANTASTIC WITH WARM DRY WEATHER EXPECTED AS
SURFACE HIGH PRESSURE DRIFTS SLOWLY THROUGH THE OHIO VALLEY.
NORTHERLY FLOW AND WEAK COLD ADVECTION INITIALLY EXPECTED BUT AS
THE CENTER OF THE HIGH SHIFTS EAST OF THE REGION...RETURN FLOW AND
THE ARRIVAL OF AN UPPER RIDGE WILL ENABLE STEADILY WARMING TEMPS
WITH THE POTENTIAL FOR SOME OF THE WARMEST AIR OF THE YEAR SO FAR
TO ARRIVE MONDAY AND TUESDAY. HIGHS IN THE 70S SATURDAY WILL RISE
INTO THE MID 80S BY MONDAY AND TUESDAY WITH SOME HINTS THAT TEMPS
COULD FLIRT WITH THE UPPER 80S IN SOUTHERN COUNTIES.
INCREASING MOISTURE BY MONDAY AND TUESDAY COULD SUPPORT AN
ISOLATED CONVECTIVE THREAT BUT IN THE ABSENCE OF ANY SIGNIFICANT
FORCING UNDER THE RIDGE...BELIEVE CHANCES ARE TOO LOW TO MENTION
AT THIS TIME.
&&
.AVIATION /DISCUSSION FOR THE 210600Z TAF ISSUANCE/...
ISSUED AT 1250 AM EDT WED MAY 21 2014
VFR CONDITIONS FOR MOST OF THIS PERIOD...WITH THE POTENTIAL FOR SOME
LOWER FLIGHT CATEGORIES (MFVR) ACROSS THE NRN SITES SUCH AS
KLAF...CLOSER TO CONVECTIVE POTENTIAL EARLY THIS MORNING. BASED ON
LATEST RADAR MOSAIC TRENDS AND SHORT TERM GUIDANCE...HAVE BACKED OFF
ON MENTIONING ANY VCTS AND CB...SAVE FOR KLAF. KIND KHUF AND KBMG
LIKELY TOO FAR SOUTH TO LIMIT ANY IMPACTS FROM A WEAKENING
THUNDERSTORM CLUSTER. MVFR AND LOWER RESTRICTIONS WILL BE POSSIBLE
WITHIN THE STORMS.
MODEL SOUNDINGS SUPPORT SOME CLEARING BY MIDDAY WITH WINDS VEERING
TO A MORE WESTERLY DIRECTION AS THE COLD FRONT SETTLES ACROSS
CENTRAL INDIANA. RENEWED CONVECTIVE DEVELOPMENT THIS AFTERNOON
EXPECTED AFTER 18Z FOCUSED ALONG AND SOUTH OF I-70. CONFIDENCE IS
LOW THIS FAR OUT IN THE FORECAST TO INCLUDE ANY MENTION OF TS AT
THIS TIME. ONLY INDICATED A LOW STRATUS DECK AROUND 4K FT AND
SCATTERED SHOWERS FOR THE TIME BEING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CP
NEAR TERM...CP/JAS
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...SMF
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
446 AM CDT WED MAY 21 2014
.UPDATE...
ISSUED AT 442 AM CDT WED MAY 21 2014
CONVECTION ALONG THE FRONT IS DISSIPATING MUCH FASTER THAN
PREVIOUSLY THOUGHT AS THE FORCING ALOFT WEAKENS. THE MOST RECENT
RAP TRENDS INDICATE DOWNWARD MOTION GETTING STRONGER ACROSS
EASTERN IOWA OVER THE NEXT SEVERAL HOURS.
THE FORECAST THROUGH SUNRISE AND THE MORNING COMMUTE HAS BEEN
UPDATED TO REFLECT THESE TRENDS.
&&
.SYNOPSIS...
ISSUED AT 330 AM CDT WED MAY 21 2014
06Z SFC ANALYSIS HAS A FRONT FROM NORTHEAST ILLINOIS INTO
NORTHEAST KANSAS. SEVERAL LOWS WERE ALONG THE FRONT FROM NORTHEAST
KANSAS INTO SOUTHEAST IOWA. A STRONGER COLD FRONT RAN FROM WESTERN
LAKE SUPERIOR INTO NORTHERN KANSAS. DEW POINTS WERE IN THE 60S
FROM THE DEEP SOUTH INTO THE WESTERN GREAT LAKES WITH 40S AND 50S
FROM THE NORTHERN PLAINS INTO THE UPPER MIDWEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT WED MAY 21 2014
WEAK LOW PRESSURE MOVING ALONG THE FRONT HELPED INITIATE NEW
STORMS ACROSS THE CENTRAL PARTS OF THE AREA. ALTHOUGH NOT SLOW
MOVING...THESE STORMS PRODUCED COPIOUS AMOUNTS OF RAINFALL IN A
VERY SHORT TIME PERIOD.
TRENDS FROM THE RAP INDICATE THE CURRENT STORMS ACROSS THE AREA
WILL CONTINUE TO MOVE EAST IN A NARROW BAND AND SLOWLY DISSIPATE
THROUGH SUNRISE AS THE OVERALL FORCING WEAKENS.
MUCH OF THE MORNING AND AFTERNOON HOURS ARE EXPECTED TO REMAIN DRY
UNTIL ANOTHER ROUND OF FORCING ARRIVES DURING PEAK HEATING. NEW
STORMS SHOULD THEN DEVELOP ACROSS THE FAR SOUTH CLOSE TO THE
FRONTAL BOUNDARY.
TONIGHT...THE AFTERNOON STORMS THAT DEVELOP WILL CONTINUE ACROSS
THE FAR SOUTH DURING THE EVENING BEFORE DISSIPATING. BOUNDARIES
FROM THIS CONVECTION ALONG WITH THE COLD FRONT WILL ALLOW A NEW
NOCTURNAL THUNDERSTORM COMPLEX TO DEVELOP IN NORTHWEST MISSOURI
AND THEN MOVE GENERALLY EAST SOUTHEAST THROUGH SUNRISE THURSDAY.
THE AREA THAT HAS THE BEST CHANCES FOR RAIN WILL BE THE FAR SOUTH
AND THE RAINFALL MAY BE LOCALLY HEAVY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED MAY 21 2014
THURSDAY THROUGH FRIDAY NIGHT THE COLD FRONT WILL REMAIN ACROSS
NORTHERN MISSOURI. INTERNALLY...THE MODELS ARE INDICATING THE THE
ACTIVE ZONE FOR NOCTURNAL THUNDERSTORM COMPLEXES WILL BE CLOSE TO
THE AREA.
THE OVERALL MOISTURE AND FORCING BEING SUGGESTED BY THE MODELS
INDICATES THAT A NOCTURNAL THUNDERSTORM COMPLEX MAY BRUSH THE FAR
SOUTHWEST/SOUTH THURSDAY/THURSDAY NIGHT BUT THEN PUSH THE FRONT
FURTHER TO THE SOUTH/WEST FOR FRIDAY AND FRIDAY NIGHT.
TEMPERATURES WILL BE CLOSE TO NORMAL.
SATURDAY ON...
THE MODEL CONSENSUS HAS MAINLY DRY CONDITIONS ON SATURDAY AS THE
BETTER MOISTURE AND FORCING REMAIN WEST OF THE AREA. TEMPERATURES
WILL BE CLOSE TO NORMAL.
STARTING SATURDAY NIGHT AND CONTINUING THROUGH TUESDAY THE MODEL
CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS EACH DAY. WILL IT RAIN
CONTINUOUSLY THE ENTIRE TIME. NO. HOWEVER...THE BIG PICTURE
INDICATES THE WEATHER PATTERN WILL BE TURNING MORE ACTIVE WITH
SOUTHWEST FLOW ALOFT DEVELOPING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1131 PM CDT TUE MAY 20 2014
THE OVERALL TREND FOR SHOWERS AND STORM THE REST OF TONIGHT SHOULD
BE DIMINISHING IN BOTH COVERAGE AND INTENSITY. THE THREAT OF
STORMS AT DBQ SHOULD BE VERY LOW WITH THE SURFACE BOUNDARY ALREADY
TO THE SOUTH. HAVE MAINTAINED A TEMPO GROUP FOR TSRA AT KCID WITH
SHRA/TSRA OVER AND JUST WEST OF THE AIRPORT. THIS ACTIVITY ALSO
SUPPORTED KEEPING A VCTS GOING A MLI FOR A FEW HOURS. THE THREAT
OF SHRA/TSRA AT KBRL SHOULD BE LOW SO DID NOT MENTION ANY
SHRA/TSRA THERE. WITH LIGHT WINDS OVER THE AREA THE REST OF
TONIGHT AND THE POTENTIAL FOR SOME CLEAR...HAVE CONTINUED THE
MENTION OF MVFR VSBYS IN FOG OVERNIGHT. FOR THE WEDNESDAY...FLIGHT
CONDITIONS SHOULD BE VFR THROUGH 06Z.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...08
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
349 AM CDT WED MAY 21 2014
.SYNOPSIS...
ISSUED AT 330 AM CDT WED MAY 21 2014
06Z SFC ANALYSIS HAS A FRONT FROM NORTHEAST ILLINOIS INTO
NORTHEAST KANSAS. SEVERAL LOWS WERE ALONG THE FRONT FROM NORTHEAST
KANSAS INTO SOUTHEAST IOWA. A STRONGER COLD FRONT RAN FROM WESTERN
LAKE SUPERIOR INTO NORTHERN KANSAS. DEW POINTS WERE IN THE 60S
FROM THE DEEP SOUTH INTO THE WESTERN GREAT LAKES WITH 40S AND 50S
FROM THE NORTHERN PLAINS INTO THE UPPER MIDWEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT WED MAY 21 2014
WEAK LOW PRESSURE MOVING ALONG THE FRONT HELPED INITIATE NEW
STORMS ACROSS THE CENTRAL PARTS OF THE AREA. ALTHOUGH NOT SLOW
MOVING...THESE STORMS PRODUCED COPIOUS AMOUNTS OF RAINFALL IN A
VERY SHORT TIME PERIOD.
TRENDS FROM THE RAP INDICATE THE CURRENT STORMS ACROSS THE AREA
WILL CONTINUE TO MOVE EAST IN A NARROW BAND AND SLOWLY DISSIPATE
THROUGH SUNRISE AS THE OVERALL FORCING WEAKENS.
MUCH OF THE MORNING AND AFTERNOON HOURS ARE EXPECTED TO REMAIN DRY
UNTIL ANOTHER ROUND OF FORCING ARRIVES DURING PEAK HEATING. NEW
STORMS SHOULD THEN DEVELOP ACROSS THE FAR SOUTH CLOSE TO THE
FRONTAL BOUNDARY.
TONIGHT...THE AFTERNOON STORMS THAT DEVELOP WILL CONTINUE ACROSS
THE FAR SOUTH DURING THE EVENING BEFORE DISSIPATING. BOUNDARIES
FROM THIS CONVECTION ALONG WITH THE COLD FRONT WILL ALLOW A NEW
NOCTURNAL THUNDERSTORM COMPLEX TO DEVELOP IN NORTHWEST MISSOURI
AND THEN MOVE GENERALLY EAST SOUTHEAST THROUGH SUNRISE THURSDAY.
THE AREA THAT HAS THE BEST CHANCES FOR RAIN WILL BE THE FAR SOUTH
AND THE RAINFALL MAY BE LOCALLY HEAVY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED MAY 21 2014
THURSDAY THROUGH FRIDAY NIGHT THE COLD FRONT WILL REMAIN ACROSS
NORTHERN MISSOURI. INTERNALLY...THE MODELS ARE INDICATING THE THE
ACTIVE ZONE FOR NOCTURNAL THUNDERSTORM COMPLEXES WILL BE CLOSE TO
THE AREA.
THE OVERALL MOISTURE AND FORCING BEING SUGGESTED BY THE MODELS
INDICATES THAT A NOCTURNAL THUNDERSTORM COMPLEX MAY BRUSH THE FAR
SOUTHWEST/SOUTH THURSDAY/THURSDAY NIGHT BUT THEN PUSH THE FRONT
FURTHER TO THE SOUTH/WEST FOR FRIDAY AND FRIDAY NIGHT.
TEMPERATURES WILL BE CLOSE TO NORMAL.
SATURDAY ON...
THE MODEL CONSENSUS HAS MAINLY DRY CONDITIONS ON SATURDAY AS THE
BETTER MOISTURE AND FORCING REMAIN WEST OF THE AREA. TEMPERATURES
WILL BE CLOSE TO NORMAL.
STARTING SATURDAY NIGHT AND CONTINUING THROUGH TUESDAY THE MODEL
CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS EACH DAY. WILL IT RAIN
CONTINUOUSLY THE ENTIRE TIME. NO. HOWEVER...THE BIG PICTURE
INDICATES THE WEATHER PATTERN WILL BE TURNING MORE ACTIVE WITH
SOUTHWEST FLOW ALOFT DEVELOPING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1131 PM CDT TUE MAY 20 2014
THE OVERALL TREND FOR SHOWERS AND STORM THE REST OF TONIGHT SHOULD
BE DIMINISHING IN BOTH COVERAGE AND INTENSITY. THE THREAT OF
STORMS AT DBQ SHOULD BE VERY LOW WITH THE SURFACE BOUNDARY ALREADY
TO THE SOUTH. HAVE MAINTAINED A TEMPO GROUP FOR TSRA AT KCID WITH
SHRA/TSRA OVER AND JUST WEST OF THE AIRPORT. THIS ACTIVITY ALSO
SUPPORTED KEEPING A VCTS GOING A MLI FOR A FEW HOURS. THE THREAT
OF SHRA/TSRA AT KBRL SHOULD BE LOW SO DID NOT MENTION ANY
SHRA/TSRA THERE. WITH LIGHT WINDS OVER THE AREA THE REST OF
TONIGHT AND THE POTENTIAL FOR SOME CLEAR...HAVE CONTINUED THE
MENTION OF MVFR VSBYS IN FOG OVERNIGHT. FOR THE WEDNESDAY...FLIGHT
CONDITIONS SHOULD BE VFR THROUGH 06Z.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...08
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS DES MOINES IA
337 AM CDT WED MAY 21 2014
.SHORT TERM /TODAY/...
ISSUED AT 337 AM CDT WED MAY 21 2014
ISOLATED CENTRAL IA THUNDERSTORM APPROACHING SEVERE LIMITS
DISSIPATED QUICKLY LAST HOUR. RAP SOUNDINGS SEEMED TO REFLECT THE
ENVIRONMENT QUITE WELL WITH POTENTIAL FOR STORMS ROOTED NEAR THE
SURFACE SHORTLY AFTER MIDNIGHT...BUT MLCINH INCREASING QUICKLY AS
BOUNDARY LAYER COOLS FURTHER AND DECOUPLING FINALLY TAKING PLACE.
WITH THIS PROGRESSION DO NOT REALLY EXPECT ANY ADDITIONAL
DEVELOPMENT UNTIL PEAK HEATING OF THE AFTERNOON...WHICH IS THE
PRIMARY FORECAST CONCERN.
SCENARIO FOR TODAY HAS CHANGED LITTLE OVER THE PAST FEW DAYS WITH
SEVERE WEATHER POTENTIAL STILL CONDITIONAL. MODELS ALL DEPICT
SIMILAR THERMODYNAMIC ENVIRONMENT WITH MLCINH ERODING DURING THE
AFTERNOON AND MLCAPES TO AROUND 1500 J/KG. HOWEVER WHILE THE CINH
HAS DIMINISHED SUFFICIENTLY FOR CONVECTION TO FIRE...LIMITING
FACTORS INCLUDE WEAK CONVERGENCE AND THE FACT THAT WARM 1-3KM
TEMPS WILL KEEP PARCELS FROM REALLY ACCELERATING UNTIL REACHING
3KM OR HIGHER. THERE IS A QUESTION WHETHER THE WEAK CONVERGENCE
WILL OVERCOME THIS. LARGE SCALE FORCING MAY HELP LIFT AND
DESTABILIZATION OF 1-3KM LAYER TOWARD 00Z HOWEVER AS CURRENT
DAKOTAS MN JET SEGMENT MOVES EASTWARD. THUS STILL HAVE SCATTERED
THUNDERSTORMS DEVELOPING IN THE EASTERN HIGHWAY 30/I80/HIGHWAY 92
CORRIDORS. MAIN SEVERE THREATS STILL APPEAR TO BE LARGE HAIL OR
WIND. LOW LEVEL SHEAR FAIRLY WEAK WITH HIGHER LCLS. STORM MOTION
WILL BE FAIRLY SLOW TOO BASED ON MEAN WIND AND BUNKERS
MOTION...LIKELY UNDER 25KTS.
.LONG TERM /TONIGHT THROUGH MONDAY/...
ISSUED AT 337 AM CDT WED MAY 21 2014
FROM TONIGHT INTO FRIDAY NIGHT OUR WEATHER PATTERN WILL BE
DOMINATED BY NORTHWEST FLOW ALOFT AND A LARGE SURFACE HIGH
PRESSURE AREA DRAPED ACROSS THE UPPER MIDWEST...WITH GENERALLY
NORTHEAST WINDS ACROSS CENTRAL IOWA. THE FRONTAL BOUNDARY MOVING
ACROSS SOUTHERN IOWA THIS TUESDAY MORNING WILL REMAIN NEARLY
STATIONARY ACROSS NORTHERN MISSOURI LATER IN THE WEEK...PROVIDING
SHOWER AND THUNDERSTORM CHANCES ACROSS FAR SOUTHERN IOWA AT TIMES
BUT PRIMARILY RAIN WILL BE LIMITED TO SOUTH OF THE BORDER
ESPECIALLY GIVEN THE DRY NORTHERLY SURFACE FLOW. HAVE MAINTAINED
JUST 20 TO OCCASIONALLY 30 POPS ACROSS OUR SOUTHERN COUNTIES WITH
NOTHING OF ANY CONSEQUENCE ANTICIPATED. MEANWHILE TEMPERATURES
WILL BE CONSIDERABLY COOLER THURSDAY AND FRIDAY...BUT LOWS SHOULD
REMAIN IN THE 40S EACH MORNING WITH NO FROST EXPECTED AT THIS
TIME.
BY EARLY SATURDAY MORNING THE LARGE 500 MB RIDGE AXIS WILL
APPROACH IOWA...MOVING OVERHEAD DURING THE DAY SATURDAY AND
HERALDING A SIGNIFICANT CHANGE IN THE SYNOPTIC REGIME FOR THE
LATTER HALF OF THE WEEKEND AND INTO NEXT WEEK. THE SURFACE HIGH
WILL MOVE OFF TO THE EAST RESULTING IN A RETURN OF SOUTHEAST TO
SOUTH SURFACE FLOW AND HIGHER DEWPOINTS...CONCURRENT WITH A 500 MB
SHORTWAVE RIDING UP RIGHT BEHIND THE RIDGE AXIS AND PROMOTING
THUNDERSTORM DEVELOPMENT ACROSS THE AREA AROUND SATURDAY NIGHT
WITH POPS IN THE 40S AND 50S FORECAST DUE TO MINOR TIMING
DISCREPANCIES IN THESE FEATURES. AFTER THIS INITIAL SURGE OF
PRECIPITATION IN A WARM ADVECTION REGIME CLEARS OUT TO THE
NORTHEAST ON SUNDAY THERE WILL BE A BRIEF WINDOW FOR MID LEVEL
RIDGING TO BUILD BACK OVERHEAD WITH A PROBABLE DRY PERIOD AROUND
SUNDAY NIGHT...HOWEVER CONCURRENTLY A LARGE 500 MB CUTOFF LOW WILL
BE MOVING INTO THE CENTRAL HIGH PLAINS NEAR THE COLORADO/KANSAS
BORDER AND SUBSEQUENTLY NORTHEASTWARD TOWARD IOWA. THIS WILL
LIKELY RESULT IN PRETTY WET WEATHER ACROSS OUR FORECAST AREA
AROUND MONDAY AND TUESDAY OF NEXT WEEK ALTHOUGH THERE ARE STILL
SOME DIFFERENCES IN THE TRACK AND TIMING OF THE LOW AMONG THE
LONGER RANGE PROGNOSTIC MODELS. ALL IN ALL IT WILL BE A SOMEWHAT
WETTER PERIOD FROM LATE SATURDAY TO THE MIDDLE OF NEXT
WEEK...HOWEVER THE SEVERE WEATHER PROBABILITY APPEARS RELATIVELY
LOW FOR THE SEASON AND THE RAIN WILL MOSTLY BE CONFINED TO THESE
TWO PERIODS...ONE FROM SATURDAY AFTERNOON INTO EARLY SUNDAY
MORNING AND THE SECOND FROM MONDAY THROUGH TUESDAY. THESE DETAILS
WILL LIKELY BECOME BETTER REFINED OVER THE NEXT FEW DAYS.
&&
.AVIATION...21/06Z
ISSUED AT 1204 AM CDT WED MAY 21 2014
LINGERING STORMS IN THE SOUTHEAST NEAR KOTM THROUGH 08Z OTHERWISE
VFR CONDITIONS EXPECTED DURING THE PERIOD. NORTH WINDS INCREASE
AFT 15Z WITH GUSTS TO NEAR 20KTS ACROSS NORTHERN PORTIONS AS
COOLER AIR AND HIGH PRESSURE BUILDS SOUTH DURING THE PERIOD. WINDS
SHOULD DIMINISH AFT 23Z. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...LEE
AVIATION...REV
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1206 AM CDT WED MAY 21 2014
.SYNOPSIS...
ISSUED AT 302 PM CDT TUE MAY 20 2014
COLD FRONT ACROSS IOWA WILL MOVE SOUTH OF THE STATE BY WED MORNING
AND BECOME STATIONARY TO THE SOUTH. HIGH PRESSURE EXPECTED TO
RIDGE INTO THE NORTH CENTRAL U.S. AND SETTLE OVER THE GREAT LAKES
BY THE WEEKEND. HIGH WILL FINALLY MOVE OFF SUNDAY WITH A
DEVELOPING FRONTAL SYSTEM IN THE ROCKIES MOVING TOWARD THE AREA
SUNDAY AND MONDAY.
&&
.SHORT TERM /TONIGHT/...
ISSUED AT 302 PM CDT TUE MAY 20 2014
BRIEF WINDOW FOR SEVERE CONVECTION LATE AFTERNOON INTO
THE EARLY EVENING HOURS AS STORMS WILL BE HIGHLY DEPENDENT ON
DAYTIME HEATING. FRONT REMAINS LAID UP ACROSS CENTRAL IOWA AND IS
ORIENTED FROM SW IOWA TOWARDS WATERLOO. VERY LITTLE...IF ANY SURFACE
CONVERGENCE OVER CENTRAL IOWA...WITH SOME CONVERGENCE PRESENT ACROSS
SOUTHWEST IOWA. AS OF 19Z...CAP IS BEGINNING TO SHOW SIGNS OF
ERODING AND MUCAPE VALUES HAVE INCREASED TO 2000 J/KG ACROSS
CENTRAL TO SOUTHERN IOWA. HOWEVER...THERE IS ABSOLUTELY NO 0-1KM BULK
SHEAR PRESENT AND THE DEEP LAYER SHEAR IS MARGINAL FOR SUSTAINABLE
UPDRAFTS. DCAPE VALUES RANGE FROM 900 TO 1100 J/KG ALONG AND SOUTH
OF THE FRONT...SO DOWNBURST THREAT IS VIABLE. IF STORMS DO
DEVELOP...STILL ANTICIPATING THE MAIN THREAT TO BE LARGE HAIL AND
DAMAGING WINDS. THE 20.15Z HOPWRF KEEPS CONVECTION INITIATION IN
EASTERN IOWA...WHILE THE 20.17Z HRRR IS MORE BULLISH WITH THE
CONVECTION DEVELOPING OVER WESTERN IOWA. THE SPC 20.12Z 4KM WRF
SEEMED LIKE A DECENT BLEND BETWEEN THE TWO. REGARDLESS...AS
MENTIONED...STORMS WILL BE HIGHLY SUNSHINE DEPENDENT AND NOT
EXPECTING CONVECTION TO LAST MUCH LATER THAN 02Z...WINDOW OF SEVERE
WEATHER OPPORTUNITY WILL BE FROM 21Z TO 02Z. HAVE SEVERE MENTION FOR
LIKELY POPS DURING THE AFOREMENTIONED TIME FRAME AND WENT DRY PAST
06Z TONIGHT FOR THE ENTIRE FORECAST AREA.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 302 PM CDT TUE MAY 20 2014
HIGH PRESSURE WILL NOSE INTO IOWA ON WEDNESDAY AND DOMINATE THE
WEATHER ACROSS THE STATE THROUGH THE REST OF THE WEEK. HIGH IS
LIKELY TO BECOME ANCHORED FOR A WHILE OVER THE COLD GREAT LAKES.
TYPICAL OF THIS TIME OF THE YEAR...BUT EVEN MORE LIKELY THIS YEAR
GIVEN THE COLDER THAN NORMAL WATER TEMPS AND THE PATTERN NOT IN AN
OVERLY PROGRESSIVE STATE.
AS THE HIGH BEGINS TO MOVE OFF AND LOSE ITS INFLUENCE
THUNDERSTORMS THAT WILL BE BRUSHING THE FAR SOUTHWEST PART OF IOWA
WILL BEGIN ADVANCING EAST. MODELS HAVE COME INTO CLOSER AGREEMENT
WITH THE OVERALL PROGRESSION. UPPER LOW WILL IMPINGE ON THE UPPER
RIDGE ADVERTISED IN THE MODELS IS ACCEPTED. A MILD AND WET PERIOD
IS ON TAP LOOKING AT THE BULK OF NEXT WEEK WITH THE SLOW MOVING
UPPER SYSTEM AND A NEGATIVE PNA SETTING UP.
&&
.AVIATION...21/06Z
ISSUED AT 1204 AM CDT WED MAY 21 2014
LINGERING STORMS IN THE SOUTHEAST NEAR KOTM THROUGH 08Z OTHERWISE
VFR CONDITIONS EXPECTED DURING THE PERIOD. NORTH WINDS INCREASE
AFT 15Z WITH GUSTS TO NEAR 20KTS ACROSS NORTHERN PORTIONS AS
COOLER AIR AND HIGH PRESSURE BUILDS SOUTH DURING THE PERIOD. WINDS
SHOULD DIMINISH AFT 23Z. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MS MAY 14
SHORT TERM...PODRAZIK
LONG TERM...MS MAY 14
AVIATION...REV
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1121 PM MDT TUE MAY 20 2014
.UPDATE...
ISSUED AT 1114 PM MDT TUE MAY 20 2014
SEVERE THREAT HAS ENDED FOR THIS EVENING IN THE LOCAL AREA WITH
BOUNDARY LAYER DECOUPLING AND INCREASING CIN. THUNDERSTORMS HAVE
RECENTLY REDEVELOPED JUST WEST OF THE AREA IN NORTHEAST COLORADO
ON NOSE OF A SOUTHERLY LLJ. HRRR HAS A GOOD HANDLE AND MOVES THAT
AREA NORTH INTO WYOMING AND THE NEBRASKA PANHANDLE...WHICH MATCHES
UP WELL WITH THE 310K ISENTROPIC FORECAST FROM THE NAM OF THE
POSITION OF THE LLJ THROUGH THE OVERNIGHT...SO WILL KEEP ONLY
SLIGHT CHANCE POPS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 219 PM MDT TUE MAY 20 2014
AIR MASS IS RATHER MOIST AND UNSTABLE BELOW 700 MB WITH LOW LEVEL
UPSLOPE IN PLACE BEHIND THE FRONT THAT IS TO OUR SOUTH. PROBLEM IS
THE LEVELS ABOVE ALL THIS. THERE IS LITTLE TO NO LIFT THROUGH JET
LEVEL AS HEIGHTS SLOWLY RISE THROUGH THE NIGHT. ALSO A RATHER
DEEP/VERY DRY EML IS ON TOP OF THE AREA. THIS IS BASICALLY SQUASHING
WHAT IS TRYING TO DEVELOP WHICH IS A RATHER WIDESPREAD FLAT CUMULUS
FIELD.
THE BEST LIFT...MOISTURE...INSTABILITY AND LEAST CAP IS OVER THE
FAR WEST AND NORTHWEST PORTION OF THE AREA THROUGH MID EVENING. SO
KEPT A SLIGHT CHANCE IN THIS AREA. BY 06Z...THE CAP STRENGTHENS
SIGNIFICANTLY AND EXPECT WHATEVER PRECIPITATION THAT WAS AROUND TO
BE DONE. WINDS SHOULD LIGHTEN UP THROUGH THE NIGHT AND IF CLOUD
COVER DECREASES ENOUGH...TEMPERATURES SHOULD HAVE NO PROBLEM WITH
READING DROPPING TO NEAR THE COOLER GUIDANCE.
AS HAS BEEN ADVERTISED THE LAST FEW DAYS...THE FIRST IN A SERIES
OF ACTIVE WEATHER DAYS WILL START ON WEDNESDAY. MOISTURE...LIFT
AND INSTABILITY INCREASE SUBSTANTIALLY OVER WHAT IS AROUND RIGHT
NOW. CONSIDERING THE STRONGER LIFT...LARGE INSTABILITY...AND SIGNIFICANT
SHEAR...SEVERE THUNDERSTORMS LOOK TO BE A GOOD BET WITH ALL THREATS
POSSIBLE. THUNDERSTORMS BEGIN BY MID AFTERNOON. CONTINUED THE
MENTION OF SEVERE THUNDERSTORMS IN THE FORECAST. MODELS ARE ALL
OVER THE PLACE WITH THE THERMAL FIELD. TENDED TO BLEND THE
GUIDANCE WITH A HEDGE TOWARD THE COOLER SIDE CONSIDERING THE THE
EXPECTED INCREASE IN CLOUD COVER AND UPSLOPE COMPONENT OF THE
WIND.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 320 PM MDT TUE MAY 20 2014
THE FOCUS/MAIN CONCERNS FOR THE LONG TERM FORECAST PERIOD ARE SEVERE
WEATHER CHANCES AND POTENTIAL FOR HEAVY RAINS. UPPER LEVEL PATTERN
WILL REMAIN FAVORABLE FOR SEVERE WEATHER WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT. WITH THE HEIGHTENED MOISTURE CONTENT OF THE
AIR...THE POTENTIAL EXISTS FOR SOME HEAVY RAINS AND FLASH FLOODING
FROM THURSDAY THROUGH SUNDAY.
SEVERE THUNDERSTORMS WILL CONTINUE INTO THE EVENING HOURS ON
WEDNESDAY. ATMOSPHERE AND WIND PROFILES BECOME MORE FAVORABLE FOR A
FEW TORNADOES DURING THE EARLY EVENING HOURS. WIND SHEAR AND HELICITY
HAVE COME DOWN SOME FROM THE MODEL RUNS YESTERDAY SO AM NOW MORE
PESSIMISTIC ABOUT THE PROBABILITY OF A STRONG TORNADO. CAN NOT RULE
OUT A STRONG TORNADO COMPLETELY WITH THE HIGH AMOUNT OF INSTABILITY
BUT SHEAR AND HELICITY DO NOT LOOK FAVORABLE FOR AN OUTBREAK OF
STRONG TORNADOES. LARGE HAIL...UP TO THE SIZE OF BASEBALLS...AND
DAMAGING WINDS REMAIN POSSIBLE THROUGH THE EVENING AS WELL BEFORE
STORMS CONGEAL INTO SMALL CLUSTERS AND FADE IN INTENSITY.
ON THURSDAY...ANOTHER ROUND OF SEVERE THUNDERSTORMS IS EXPECTED.
THIS IS A SIMILAR SETUP TO WEDNESDAY WITH A STALLED FRONT LINGERING
ALONG HIGHWAY 96 IN EASTERN COLORADO AND WESTERN KANSAS. FOR THIS
DAY...CONVECTION LOOKS TO BE MORE WIDESPREAD. INSTABILITY HAS
INCREASED FROM YESTERDAYS MODEL RUNS FOR THURSDAY WITH SBCAPE OF
2000-3500 J/KG. LARGE HAIL...POSSIBLY SIGNIFICANT WITH HAIL TO THE
SIZE OF BASEBALLS...AND DAMAGING WINDS WOULD BE THE PRIMARY THREATS.
A FEW TORNADOES ARE POSSIBLE FOR THURSDAY AS WELL...HOWEVER...WIND
SHEAR AND HELICITY DECREASE FOR THURSDAY AS THE WIND FIELD ALOFT
WEAKENS. WITH WIDESPREAD CONVECTION EXPECTED AND CONVECTION LIKELY
ON WEDNESDAY...THINK THE THREAT OF FLASH FLOODING INCREASES THURSDAY
FOR LOCATIONS WHERE STORMS ARE ABLE TO TRAIN OR WHERE GROUND HAS
BEEN SATURATED FROM WEDNESDAYS CONVECTION. OVERALL...THE FORECAST
CONFIDENCE FOR THURSDAY IS SOMEWHAT LOW DUE TO CONCERNS OVER THE
EVOLUTION OF CONVECTION WEDNESDAY. MODELS SEEM CONFIDENT THE
ATMOSPHERE WILL RECHARGE TO THE SOUTH ALONG THE FRONT SO WILL GO
WITH THIS MODE OF THINKING FOR NOW. THUNDERSTORM OUTFLOWS...AIR
STABILIZED BY WEDNESDAY NIGHTS CONVECTION AND POSSIBLE DAYTIME
STRATUS ARE MAJOR CONCERNS FOR THURSDAY.
FROM FRIDAY THROUGH SUNDAY...SHORTWAVE TROUGHS SWING AROUND THE
STATIONARY UPPER LEVEL LOW...CONTINUING THE CHANCES FOR SHOWERS AND
THUNDERSTORMS EACH AFTERNOON AND EVENING. PRECIPITABLE WATER ANOMALIES
APPROACH 2 STANDARD DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR
THROUGH THE WEEKEND. INCREASED QPF FORECAST AND MAINTAINED MENTION
OF LOCALLY HEAVY RAIN/FLASH FLOODING. THIS WILL LIKELY NOT BECOME A
WIDESPREAD FLOODING EVENT BUT LOCAL PROBLEMS ARE POSSIBLE WHERE
SOILS BECOME SATURATED AND STORMS TRAIN.
THE UPPER LEVEL LOW FINALLY EJECTS ACROSS THE HIGH PLAINS MONDAY
WITH DRYING CONDITIONS TOWARDS THE MIDDLE OF NEXT WEEK. MONDAY
SHOULD BE THE LAST PRECIPITATION CHANCE AS SHORTWAVE RIDGING BUILDS
IN BEHIND THE LOW. WARMER TEMPERATURES...INTO THE MID 80S...RETURN
TUESDAY UNDER CLEARING SKIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1114 PM MDT TUE MAY 20 2014
VFR EXPECTED THROUGH THE OVERNIGHT WITH ONLY A SLIGHT CHANCE FOR
AN ISOLATED SHOWER OR THUNDERSTORM. NEXT PRECIPITATION CHANCES
WILL COME WEDNESDAY AFTERNOON WITH STORMS REDEVELOPING SOUTH OF
INTERSTATE 70 NEAR A STATIONARY FRONT THEN MOVING NORTH IN THE
LATE AFTERNOON AND EVENING HOURS. SOME STORMS MAY BE SEVERE WITH
LARGE HAIL AND DAMAGING WINDS ON WEDNESDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...024
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...024
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1208 AM CDT Wed May 21 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Wednesday)
Issued at 314 PM CDT TUE MAY 20 2014
The forecast seems to be unfolding as expected with the latest NAM
forecast soundings showing a capping inversion holding strong over
the area through the afternoon. 19Z water vapor imagery shows a
closed low over central CA with southwesterly flow aloft. There does
not appear to be much in the way of large scale forcing within the
upper flow, and low level convergence along an inverted surface
trough appears to be marginal with not much of a CU field in the
warm sector. The HRRR does try to bring convection off the higher
terrain to the west, but again shows it weakening due to the
elevated mixed layer before it reaches central KS. So expect a dry
forecast heading into Wednesday. Have trended lows tonight a couple
degrees cooler across northern KS. With the trough axis forecast to
pivot more west to east across the forecast area, winds are likely
to become light. This combined with mostly clear skies should allow
for some decent radiational cooling and lows in the lower 60s across
the northern counties. East central KS is likely to stay south of
the trough axis in the warmer air with higher dewpoints so have kept
lows in the mid to upper 60s.
For Wednesday, models are in agreement that the weak boundary will
be across the area with good moisture pooling along it. The NAM and
GFS warm the boundary layer enough so that CAPE values increase to
3000 or 3500 J/kg. They also cool mid levels some so that there is
very little or no CIN by the mid afternoon. Large scale forcing
continues to look unimpressive, but there could be enough
convergence along the boundary for some isolated storms to develop
by the late afternoon. Deep layer shear of 40 to 50 KTS also suggest
that if storms are able to form, they could become supercellular. At
this point low level shear parameters show little or no chance for
tornadoes so main risks with storms that form would be a hail and
wind. Highs Wednesday should not be quite as warm as models weaken
the thermal ridge over the area. Because of this highs are forecast
to be in the middle and upper 80s.
.LONG TERM...(Wednesday Night through Tuesday)
Issued at 314 PM CDT TUE MAY 20 2014
Somewhat above normal thunderstorm chances continue to dominate the
middle and later portions of the forecast. Have shaded chances
slightly up and down when some confidence exists in possible
evolution, but overall confidence on timing and placement of precip
not high.
Wednesday night into Thursday night still present the more dynamic
storm periods with the stationary front keeping some minor
baroclinicity. Any local afternoon storms could easily persist in
the evening hours and keep at least modest severe weather potential,
but highest coverage for overnight Wednesday night into early
Thursday still at least moderately dependent on where convection can
be the most robust and organized to the west. Models differ on
where this will be, but some indications this could be a bit farther
south than earlier anticipated. A rather warm and moist boundary
layer should keep low-level parcels rather buoyant and NAM and GFS
agree with limited CIN through Wednesday night for at least some
severe potential. Synoptic surface high to the northeast and low the
southwest should keep at lest some low-level convergence intact for
Thursday afternoon over the area as long as overnight and early day
convection does not displace the effective front elsewhere. Corfidi
vectors turn more southeast and again may be rather parallel to the
front for overnight convection to again pass through. By Friday
afternoon, more meridional low level flow takes hold for the Central
Plains and should greatly reduce convergence, again barring
MCS-dominated surface features. GFS and ECMWF are rather consistent
with an upper wave emerging from the old trough, but this appears to
be at least partially due to previous convection. Despite weakening
mid-level lapse rates, instability should continue to be at least
modest with good moisture through the column for some storm chances
into Sunday. Better dynamic forcing aloft could commence Sunday
night into Tuesday afternoon if the GFS and ECMWF are correct with
the low finally pushing through, but of course timing ejection of
cut-off lows is difficult at best. Little change in temperatures is
forecast, but again highs will be greatly impacted by any persistent
MCS that persists.
&&
.AVIATION...(For the 06Z TAFs through 06Z Wednesday Night)
Issued at 1207 AM CDT WED MAY 21 2014
VFR conditions expected through the period. Thunderstorm chances
increase tomorrow afternoon around 21z with another more
widespread round possible after this issuance in the late evening
early morning hours. 67
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...65
AVIATION...67
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
343 AM EDT WED MAY 21 2014
.SHORT TERM... TODAY AND TONIGHT
SURFACE AND MODEL ANALYSIS FIELDS PROVIDE A STRAIGHTFORWARD
DIAGNOSIS FOR ONGOING CONVECTIVE FORCING BUT THAT STILL LEAVES A
CHALLENGING FORECAST FOR WHAT MAY FOLLOW LATER TODAY THROUGH THIS
EVENING UNTIL THE SURFACE COLD FRONT PUSHES THROUGH THE REGION
CLOSER TO MIDNIGHT.
THE LARGE SCALE PATTERN IS ANCHORED BY A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WHICH HAS AN OCCLUDED FRONT EXTENDING INTO
A BROADER SURFACE WAVE OVER LOWER MICHIGAN RIPPLING ALONG THE MAIN
WARM/STATIONARY FRONT EXTENDING INTO OUR AREA. THE LOW LEVEL
MOISTURE AXIS IS ALIGNED ALONG THIS SURFACE PRESSURE FEATURE WITH
BACKGROUND VERTICAL MOTION SUPPLIED BY AGEOSTROPHIC CIRCULATION
UNDER THE SOUTH FLANK OF THE UPPER JET. THE RESULT IS CONTINUED
SUPPORT FOR ONGOING CONVECTION AND DEVELOPMENT OF ADDITIONAL SHOWERS
AND WEAKER STORMS NORTH OF THE SURFACE BOUNDARY. SINCE MIDNIGHT...
CONCERN HAS TRANSITIONED FROM SEVERE WEATHER POTENTIAL NEAR THE OHIO
BORDER TO EXCESSIVE RAINFALL THROUGH THE I-69 CORRIDOR...ALTHOUGH
INTENSITY OF STORMS WILL REMAIN STRONG NEAR THE OHIO BORDER WHERE
MID LEVEL LAPSE RATES ARE GREATEST. AT THE SAME TIME...EXPECT
COVERAGE OF SHOWERS AND STORMS WILL BE NUMEROUS FARTHER NORTH WITHIN
THE FRONTAL CIRCULATION IN THE 850-700 MB LAYER. BASED ON MODEL MEAN
RH TRENDS...THERE IS GOOD AGREEMENT THAT THIS CLUSTER OF CONVECTION
WILL MOVE EAST OF THE AREA AROUND NOON.
OTHER THAN A SLOW PROGRESSION OF THE SURFACE PRESSURE PATTERN...
THERE WILL NOT BE MUCH DIFFERENCE IN THE LARGE SCALE FEATURES
AFFECTING THE AREA DURING THE AFTERNOON COMPARED TO THE CURRENT
SETUP. THE CONSENSUS OF MODEL MSL PRESSURE SOLUTIONS PLACES THE
TRIPLE POINT OF THE OCCLUSION OVER NORTHERN LOWER MICHIGAN AROUND
18Z. SOUTHWEST FLOW RETURNING BEHIND THE MORNING CONVECTIVE PATTERN
WILL BE ADEQUATE TO MAINTAIN THUNDERSTORM POTENTIAL WITH SUFFICIENT
RECOVERY OF INSTABILITY. THE TIMING AND MAGNITUDE OF RECOVERY IS THE
MAIN UNCERTAINTY IN THE FORECAST AND SEVERE WEATHER POTENTIAL.
REASONABLE DOWNWARD ADJUSTMENTS TO THE LATEST NAM AND RAP OUTPUT
STILL OFFERS 0-1KM MLCAPE RECOVERING TO ABOUT 1500 J/KG MID TO LATE
AFTERNOON...BUT WITH MODEST MID LEVEL LAPSE RATES OF 6-7C/KM IN THE
700-500 MB LAYER AS THE EML SUPPORTING THE EARLY MORNING STORMS IS
DIRECTED INTO THE UPPER OHIO VALLEY. REMAINING IN PLACE WILL BE THE
SOUTHERN FRINGES OF DYNAMIC SUPPORT FROM THE UPPER WAVE OVER
NORTHERN ONTARIO...AND STRONG WESTERLY FLOW ALOFT OVER LOWER
MICHIGAN. MODEL SOUNDINGS INDICATE A SOLID STRAIGHT-LINE HODOGRAPH
ANCHORED BY 50-60 KNOTS OF FLOW AROUND 500 MB AND 0-6 KM BULK SHEAR
AROUND 50 KNOTS. DIFFERENT FROM YESTERDAY WILL BE A MORE VEERED LOW
LEVEL FLOW WHICH IS LESS FAVORABLE FOR TORNADOGENESIS...BUT THE
OVERALL PROFILE IS STILL SUPPORTIVE OF STORM SPLITS/SUPERCELL
ORGANIZATION EARLY IN THE CONVECTIVE CYCLE. PLAN TO CALL FOR
ISOLATED STORMS APPROACHING SEVERE LIMITS UNTIL SEVERE POTENTIAL CAN
BE REFINED WITH OBSERVATIONS AS THE DAY PROGRESSES. SHOWERS AND
WEAKER STORMS SHOULD OTHERWISE BECOME NUMEROUS BY LATER AFTERNOON
THROUGH THE EVENING BEFORE THE COLD FRONT SWEEPS EVERYTHING OUT OF
THE REGION AROUND MIDNIGHT.
&&
.LONG TERM...
COLD ADVECTION PATTERN EMBEDDED WITHIN CORRIDOR OF CYCLONIC
NORTHWEST FLOW ALOFT WILL PERSIST INTO FRIDAY MORNING. H85
TEMPERATURES ARE PROGGED TO FALL FROM 10C LATE TONIGHT TO 4C FRIDAY
MORNING. ONGOING COLD ADVECTION WILL ENSURE STEEP LOW-LEVEL LAPSE
RATES CAPABLE OF SUPPORTING EXPANSIVE AFTERNOON STRATOCU,
PARTICULARLY IN THE PRESENCE OF LOW AMPLITUDE DISTURBANCES RIPPLING
ALONG IN THE FLOW ALOFT. INFLUX OF THE COOLER AIRMASS COMBINED WITH
CLOUDS DEVELOPING DURING PEAK HEATING WILL LIMIT HIGHS TO THE
MID/UPPER 60S ON BOTH FRIDAY AND SATURDAY. HIGH AMPLITUDE RIDGE WILL
VERY GRADUALLY MIGRATE OVER THE GREAT LAKES THROUGH THE HOLIDAY
WEEKEND AS THE PATTERN SLOWS IN RESPONSE TO THE CLOSED LOW OVER THE
SOUTHWEST UNITED STATES. REBOUNDING THERMAL PROFILES WILL BE
ACCOMPANIED BY DEEP LAYER SUBSIDENCE, ADDING CONFIDENCE TO THE
FORECAST FOR A WARM AND MOSTLY SUNNY HOLIDAY WEEKEND. TEMPERATURES
WILL MODERATE FROM LOW/MID 70S ON SATURDAY TO THE LOW 80S BY MONDAY.
&&
.MARINE...
A WEAK COLD FRONT WILL SWING THROUGH THE CENTRAL GREAT LAKES THIS
AFTERNOON. BRISK NORTHWEST WINDS WILL THEN BUILD IN FOR TONIGHT AND
THURSDAY. ANY THUNDERSTORMS WHICH DEVELOP TONIGHT THROUGH TOMORROW
MAY BE STRONG TO SEVERE. LIGHT WINDS WILL RETURN FOR THE WEEKEND AS
HIGH PRESSURE SETTLES OVER THE AREA.
&&
.AVIATION...ISSUED 1225 AM EDT WED MAY 21 2014
//DISCUSSION...
SURFACE ANALYSIS INDICATES A WEAK WAVE OF LOW PRESSURE RIPPLING
ALONG THE WARM FRONT LEFT OVER FROM YESTERDAY. THIS WILL CONTINUE TO
SUPPORT THUNDERSTORM ACTIVITY OVER SW LOWER AND NORTHERN INDIANA
WHICH IS EXPECTED TO DEVELOP EASTWARD WITH ENOUGH CONFIDENCE TO
INCLUDE IN THE TERMINALS FROM PTK SOUTH THROUGH THE DTW AREA. WEAK
EASTERLY FLOW NORTH OF THE BOUNDARY COULD FUNNEL SOME IFR CONDITIONS
INTO MBS AND MVFR INTO FNT IN EITHER OR LOW CEILING AND FOG BY
SUNRISE. BEHIND TONIGHTS THUNDERSTORM ACTIVITY...ADDITIONAL SHOWERS
AND LOW CEILING WILL SPREAD ACROSS THE REGION AS THE WAVE OF LOW
PRESSURE WORKS ACROSS LOWER MICHIGAN DURING THE MORNING. STILL SOME
OPPORTUNITY FOR NEW THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON
SUBJECT TO SUFFICIENT SURFACE HEATING.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE FOR THUNDERSTORMS BETWEEN 04-07Z TONIGHT.
* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET AFTER 04Z TONIGHT
THROUGH MUCH OF WEDNESDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...BT
LONG TERM....JVC
MARINE.......JVC
AVIATION.....MANN/BT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1225 AM EDT WED MAY 21 2014
.AVIATION...
//DISCUSSION...
SURFACE ANALYSIS INDICATES A WEAK WAVE OF LOW PRESSURE RIPPLING
ALONG THE WARM FRONT LEFT OVER FROM YESTERDAY. THIS WILL CONTINUE TO
SUPPORT THUNDERSTORM ACTIVITY OVER SW LOWER AND NORTHERN INDIANA
WHICH IS EXPECTED TO DEVELOP EASTWARD WITH ENOUGH CONFIDENCE TO
INCLUDE IN THE TERMINALS FROM PTK SOUTH THROUGH THE DTW AREA. WEAK
EASTERLY FLOW NORTH OF THE BOUNDARY COULD FUNNEL SOME IFR CONDITIONS
INTO MBS AND MVFR INTO FNT IN EITHER OR LOW CEILING AND FOG BY
SUNRISE. BEHIND TONIGHTS THUNDERSTORM ACTIVITY...ADDITIONAL SHOWERS
AND LOW CEILING WILL SPREAD ACROSS THE REGION AS THE WAVE OF LOW
PRESSURE WORKS ACROSS LOWER MICHIGAN DURING THE MORNING. STILL SOME
OPPORTUNITY FOR NEW THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON
SUBJECT TO SUFFICIENT SURFACE HEATING.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE FOR THUNDERSTORMS BETWEEN 04-07Z TONIGHT.
* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET AFTER 04Z TONIGHT
THROUGH MUCH OF WEDNESDAY.
&&
.PREV DISCUSSION...ISSUED 915 PM EDT TUE MAY 20 2014
UPDATE...
COMPOSITE SURFACE BOUNDARY EXTENDING FROM TORONTO THROUGH CHICAGO
INTO IOWA HAS IGNITED A FAIR AMOUNT OF DISCRETE CONVECTION THIS
EVENING. THE ACTIVITY OVER LOWER MICHIGAN HAS BEEN RESTRICTED TO A
SINGLE CELL RESPONSE CURRENTLY MOVING THROUGH OAKLAND AND MACOMB
COUNTIES. THE RESPONSE HAS BEEN FAR MORE IMPRESSIVE OVER NORTHERN
ILLINOIS ALONG THE PERIPHERY OF MUCH GREATER QUALITY INSTABILITY
/COMPARE KDVN AND KDTX RAOB/. AS THE BOUNDARY CONTINUES TO SETTLE
SOUTH SLOWLY DURING THE LATE EVENING HOURS...UPSTREAM CONVECTION
WILL ADVANCE IN A NARROW CORRIDOR OF MODERATE INSTABILITY AHEAD
OF THE BOUNDARY. STORMS HAVE YET TO GEL INTO AN ORGANIZED COMPLEX
AND WILL REQUIRE A LITTLE MORE SIMMER TIME TO FORM A COMMON COLD
POOL. MOREOVER...LATEST RADAR TRENDS SUGGEST PREFERENTIAL
DEVELOPMENT FAVORING A SOUTHWARD DRIFT. EXPECTING ANY ORGANIZATION
TO FAVOR A MOTION THAT KEEPS THE MOST ROBUST ACTIVITY ACROSS
NORTHERN INDIANA AND NORTHWEST OHIO DURING THE OVERNIGHT HOURS.
REGARDLESS...PLENTY OF INSTABILITY TO SUPPORT SOME SEMBLANCE OF
ELEVATED NOCTURNAL CONVECTION ACROSS METRO DETROIT SOUTH TO THE
BORDER. HOWEVER...GREATEST POTENTIAL FOR SEVERE IS BECOMING
BETTER ESTABLISHED SOUTH OF THE BORDER /SEE LATEST SPC SWOMCD/.
PREV DISCUSSION...ISSUED 345 PM EDT TUE MAY 20 2014
SHORT TERM... THROUGH TONIGHT
SHORT TERM CONCERNS STILL REVOLVE AROUND CONVECTIVE TRENDS AND
POTENTIAL FOR SEVERE WEATHER. FIRST...FOR THE REMAINDER OF THIS
AFTERNOON INTO THE EVENING. FAST ZONAL UPPER LEVEL FLOW IS OVER THE
UPPER MIDWEST BETWEEN A RIDGE OVER THE SOUTHERN PLAINS AND A TROUGH
OVER SOUTHERN MANITOBA/SOUTHWESTERN ONTARIO. 18Z SURFACE ANALYSIS
SHOWED A WARM FRONT ARCING SE INTO MICHIGAN FROM ROUGHLY NORTH OF
MUSKEGEON TO LAPEER AND THEN SOUTH TO AROUND MONROE. THE
NORTH/EASTWARD PROGRESS OF THE FRONT IS BEING HINDERED BY FLOW OFF
THE COOLER LAKES. TEMPS CONTINUE TO WARM INTO THE LOW/MID 70S SOUTH
OF THE FRONT WITH DEWPOINTS IN THE LOW 50S TO NEAR 60. SOME CUMULUS
IS DEVELOPING OVER SOUTHWESTERN LOWER IN THE LEE OF LAKE
MICHIGAN...BUT SO FAR IT IS SHALLOW. MIDLEVEL LAPSE RATES ARE FAIRLY
MEAGER BUT SHOULD INCREASE INTO THE EVENING. SOME MODEST SURFACE
BASED INSTABILITY MAY DEVELOP AS WE GET LATER INTO THE AFTERNOON AND
EVENING. DEEP LAYER SHEAR OF 35-50KT IS FAVORABLE FOR ORGANIZED
CONVECTION SHOULD ANYTHING DEVELOP...BUT THE LACK OF CLEAR FORCING
MECHANISMS AND GREATER INSTABILITY WILL KEEP POPS IN THE LOW CHANCE
RANGE THROUGH 00Z.
ANOTHER THREAT IS EXPECTED TO DEVELOP AFTER 04Z...BUT IT
IS FAR FROM CERTAIN. DISCRETE CELLS ARE EXPECTED TO DEVELOP OVER
NORTHERN ILLINOIS LATE THIS AFTERNOON. THESE STORMS MAY EVOLVE INTO
ONE OR MORE FORWARD-PROPAGATING QUICK-MOVING MCS...WHICH COULD BE
LONG-LIVED DUE TO CONTINUED STRONG DEEP-LAYER SHEAR AND APPRECIABLE
INSTABILITY. THIS SCENARIO IS SUPPORTED BY THE 16Z HRRR AND THE 12Z
NMM. THESE COMPLEXES WOULD PREFERENTIALLY MOVE TOWARD THE RESERVOIR
OF GREATER INSTABILITY...WHICH IS BETTER TO OUR SOUTH WHERE THE
GREATER MIDLEVEL LAPSE RATES WILL RESIDE. STILL...THE THREAT IS GOOD
ENOUGH TO INCLUDE A SLIGHT CHANCE OF SEVERE WEATHER FROM M-59 SOUTH
/WITH THE BEST CHANCES NEAR THE OHIO BORDER/ FROM AROUND 04-10Z.
DAMAGING WIND WOULD BE THE MAIN THREAT...WITH LARGE HAIL AND AN
ISOLATED TORNADO SECONDARY. HEAVY RAIN IS ALSO POSSIBLE AS PWATS
INCREASE TO 1.3-1.5 INCHES.
LONG TERM...
LARGE UPPER LEVEL LOW SLOWLY WORKING THROUGH ONTARIO
TOMORROW...DROPPING SOUTHEAST INTO NEW ENGLAND THURSDAY NIGHT INTO
FRIDAY WILL DELIVER A RESPECTABLE SHOT OF COOL AIR TO SOUTHEAST
MICHIGAN THURSDAY INTO FRIDAY...BEFORE TEMPERATURES QUICKLY MODERATE
OVER THE WEEKEND AS AMPLIFIED UPPER LEVEL RIDGE BUILDS INTO THE
GREAT LAKES REGION...LIKELY LEADING TO EVEN WARMER TEMPERATURES (80+
DEGREES) EARLY NEXT WEEK.
AS FAR AS TOMORROW GOES...THE FORECAST WILL BE IMPACTED WITH WHAT
OCCURS OVERNIGHT...AS POTENTIAL DEPARTING MCV MAY CAST
SHADOW/SUBSIDENCE WAKE THROUGH A GOOD PORTION OF THE DAY.
OTHERWISE...DO HAVE SHORTWAVE TROUGH AXIS EXTENDING FROM THE
PREVIOUS MENTIONED UPPER LEVEL LOW OVER ONTARIO...WHICH WILL CAUSE
SURFACE COLD FRONT TO SWING THROUGH DURING THE PEAK DIURNAL CYCLE.
STRONG WESTERLY JET (65 KNOTS AT 500 MB) CORE WILL BRING AN
INCREASED RISK OF DAMAGING WINDS IF THUNDERSTORMS ARE ABLE TO
DEVELOP DURING THE AFTERNOON HOURS. THE PROBLEM IS WE CAN NOT FULLY
COUNT ON A MORNING CAP/LULL...AND STORMS COULD EASILY DEVELOP
EARLIER IN THE DAY. DURING THE AFTERNOON HOURS...THE INCREASING
MIXING DEPTHS WE ACCELERATE THE WESTERLY DRYING OUT
PROCESS...LEADING TO QUESTIONS WITH THE AREAL COVERAGE OF THE
POTENTIAL STORMS DEVELOPING ALONG THE COLD FRONT...AS MAX
INSTABILITY LOOKS TO BE OVER THE NORTHERN OHIO VALLEY. WITH THAT
SAID...IT LOOKS FAIRLY LIKELY SOMETIME DURING THE 12 HOUR
WINDOW...NUMEROUS SHOWERS AND THUNDERSTORMS WILL OCCUR...AND
UNFORTUNATELY WILL CARRY GENERIC HIGH SCATTERED/LOW LIKELY POPS
THROUGH THE DAY...AS TONIGHT`S EVOLUTION WILL BE A ONE OF THE KEYS
FOR TOMORROWS WEATHER.
STRONG NORTHWEST FLOW WEDNESDAY NIGHT INTO THURSDAY...WITH 850 MB
TEMPS FALLING INTO THE MID SINGLE NUMBERS. THE CYCLONIC/COLD
ADVECTION AND STEEP LOW LEVEL LAPSE RATES SHOULD BE SUFFICIENT TO
GENERATE PLENTY OF CLOUDS DURING THE DAYTIME HOURS OF
THURSDAY...LIKELY CAPPING MAXES IN THE UPPER 60S TO AROUND 70
DEGREES. ANOTHER PIECE OF ENERGY ROTATING SOUTH THROUGH THE CENTRAL
GREAT LAKES ON FRIDAY SHOULD MAINTAIN THE COOLER TEMPERATURES AND
CONSIDERABLE CLOUDS DURING THE DAYTIME HOURS...AND EVEN SUFFICIENT
DIURNAL INSTABILITY/CAPES/CLOUD DEPTHS (4-12 KFT) TO POSSIBLY
PRODUCE ISOLATED LIGHT SHOWERS.
12Z EURO IS IN DECENT AGREEMENT WITH THE CANADIAN/GFS IN BUILDING
UPPER LEVEL RIDGE OVER THE CENTRAL GREAT LAKES ON
MONDAY...SUPPORTING HIGHS IN EXCESS OF 80 DEGREE WITH INCREASING
SOUTHWEST FLOW AND 850 MB TEMPS WARMING INTO THE MID TEENS INTO
TUESDAY.
MARINE...
INCREASED SOUTHEAST FLOW OVER OUTER SAGINAW BAY AND THE ADJACENT
NEARSHORE WATERS DUE TO THUNDERSTORMS TRACKING THROUGH THE AREA WILL
DIMINISH AS WARM FRONT WEAKENS TONIGHT. A STRONG COLD FRONT WILL
SWING THROUGH THE CENTRAL GREAT LAKES TOMORROW AFTERNOON...WITH
BRISK NORTHWEST WINDS FOLLOWING FOR WEDNESDAY NIGHT AND THURSDAY.
ANY THUNDERSTORMS WHICH DEVELOP TONIGHT THROUGH TOMORROW MAY BE
STRONG TO SEVERE. COOLER AND MORE STABLE AIRMASS WILL FILTER INTO
THE REGION THURSDAY AND FRIDAY...BUT ISOLATED SHOWERS ARE STILL
POSSIBLE. A LARGE UPPER LEVEL RIDGE BUILDING INTO THE GREAT LAKES
REGION OVER THE WEEKEND WILL LEAD TO WARMUP TEMPERATURES AND LIGHT
WINDS.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MANN/BT
UPDATE.......MANN
SHORT TERM...DT
LONG TERM....SF
MARINE.......SF
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS JACKSON MS
331 AM CDT WED MAY 21 2014
.SHORT TERM...TODAY THROUGH THURSDAY NIGHT...SPRAWLING MID/UPPER
LEVEL ANTICYCLONE...CENTERED OVER THE LOWER MS VALLEY...CONTINUES TO
PROVIDE TRANQUIL WEATHER OVER THE FORECAST AREA AND THIS LOOKS TO
CONTINUE THROUGH THE SHORT TERM. AT THE SURFACE...RIDGE AXIS REMAINS
POSITIONED ALONG THE NORTHERN GULF COAST. LOW LEVEL FLOW ABOUT THIS
AXIS CONTINUES TO PROVIDE AN OPPORTUNITY FOR STRATUS/FOG DEVELOPMENT
THROUGH ISENTROPIC ASCENT AGAIN THIS MORNING AND TO SOME EXTENT
THURSDAY MORNING AS WELL.
THIS ISENTROPIC ASCENT CAN BE BEST SEEN IN THE 290-295K THETA LAYER
WITH BEST ZONE OF PRESSURE ADVECTION COUPLED WITH RISING THETA
SURFACES ALONG AND SOUTH OF HIGHWAY 84. ALREADY STRATUS STREAMERS
HAVE DEVLOPED FROM KMCB-K1R7. HRRR AND SREF DATA INDICATING
STRATUS/FOG AREA WILL CONTINUE TO FILL IN THIS MORNING OVER SOUTHERN
PORTIONS OF THE AREA...BUT...LIKE YESTERDAY MORNING...DISSIPATE
RAPIDLY WITHIN A COUPLE HOURS AFTER SUNRISE.
HIGH PRESSURE CENTER LOOKS TO BECOME SITUATED OVER SOUTH MS TONIGHT.
THIS WILL SERVE TO CHANGE OUR LOW LEVEL WINDS TO A MORE SOUTHWESTERLY
DIRECTION AND LESS FAVORABLE FOR STRATUS DEVELOPMENT BOTH THURSDAY
AND FRIDAY MORNINGS. ONLY THE EXTREME SW SECTION OF THE FORECAST AREA
WILL MAINTAIN ENOUGH OF A SOUTHERLY WIND COMPONENT TO SEE SOME
STRATUS THURSDAY MORNING.
LOOKING AT THE GFS MOS ENSEMBLE...STANDARD DEVIATIONS NEAR ZERO ARE
NOT OFFERING MUCH OF AN OPPORTUNITY TO IMPROVE ON THE TEMPERATURE
FORECAST. AS THE SURFACE HIGH BECOMES CENTERED OVER SOUTH
MS...SIGNIFICANT LOW LEVEL MOISTURE RETURN WILL DIMINISH ALLOWING
FOR CONTINUED LARGE DIURNAL RANGES AND MAX TEMPS TO BEGIN INCHING UP
A LITTLE EACH DAY AS MOS IS INDICATING./26/
.LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY...WARM AND DRY FOR THE
MEMORIAL DAY WEEKEND WITH SLIGHTLY ABOVE NORMAL TEMPERATURES BY ~5F
DEGREES. RAIN CHANCES WILL INCREASE EACH DAY STARTING NEXT MONDAY
INTO MID WEEK AS A MID-LEVEL DISTURBANCE SLOWLY APPROACHES THE
REGION.
OVERALL CONUS PATTERN LATE WEEK INTO THE HOLIDAY WEEKEND WILL
FEATURE A MID/UPPER LEVEL TROUGH BEGINNING TO CUT-OFF OVER THE
DESERT SW AS RIDGING CONTINUES OVER THE SE WITH A SHARP S/WV TROUGH
PIVOTING ACROSS GREAT LAKES INTO THE MID ATLANTIC. THE MID ATLANTIC
TROUGH WILL ACT TO BRING A NW/SE ORIENTED WEAK DENSITY/CONVERGENCE
BOUNDARY ACROSS N/NE MS INTO AL OVER THE WEEKEND. DESPITE THIS
LOW-LVL FOCUS AND SOME HINT OF EMBEDDED IMPULSES WITHIN THE BACKSIDE
NW FLOW...PWATS OF 1.2-1.3"...HIGH LCL INVERTED "V" SOUNDINGS...AND
MASS FIELDS SUGGESTIVE OF LIMITED CONVECTION IF ANY...HAVE KEPT WEATHER
WORDING OUT OF GRIDS THIS PACKAGE. A ROGUE SHOWER CAN NOT BE
COMPLETELY RULED OUT FOR THE NE CORNER THOUGH AND WILL MONITOR
TRENDS.
FOR MON-WED NEXT WEEK...OPS GFS AND EC ARE IN DECENT AGREEMENT WITH
CUT-OFF LOW SLOWLY PROGRESSING EAST ACROSS THE PLAINS TOWARDS THE
MID TO LOWER MS VALLEY BY MID WEEK. AS THIS FEATURE APPROACHES...
RAIN/TSTORM CHANCES WILL INCREASE WITH SOME LINGERING ACTIVITY DURING
THE OVERNIGHT HOURS TUES INTO WED WITH GREATER COVERAGE WED AFTN.
FOR WEATHER ELEMENTS...MEX LOWS WERE RAISED 1-4F NEXT WEEK TO ALIGN TOWARDS
RAW EC/GFS DEWPOINTS. MEX POPS WERE BUMPED UP SLIGHTLY TUES-WED./ALLEN/
&&
.AVIATION...STRATUS/FOG THIS MORNING WILL ALLOW FOR IFR CONDITIONS
UNTIL AROUND 14Z FOR KJAN/KHKS/KMEI/KHBG. THEREAFTER...VFR
CONDITIONS WILL PREVAIL./26/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 89 63 90 63 / 0 0 0 0
MERIDIAN 89 60 90 60 / 0 0 0 0
VICKSBURG 87 61 88 59 / 0 0 0 0
HATTIESBURG 88 62 90 62 / 0 0 0 0
NATCHEZ 87 62 86 63 / 0 0 0 0
GREENVILLE 88 65 89 65 / 0 0 2 2
GREENWOOD 88 63 89 62 / 0 0 2 2
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1256 AM CDT WED MAY 21 2014
.SYNOPSIS...
ISSUED AT 312 PM CDT TUE MAY 20 2014
A FAIRLY ACTIVE H5 PATTERN HAS DEVELOPED ACROSS THE
CONUS OVER THE PREVIOUS 24 HOURS. LOW PRESSURE WAS ANCHORED OFF THE
COAST OF MAINE...WITH ANOTHER LOW OVER NORTHERN PORTIONS OF THE
CENTRAL VALLEY OF CALIFORNIA. ANOTHER LOW WAS PRESENT OVER THE
ALASKA PANHANDLE WITH ANOTHER LOW OVER NORTHERN PORTIONS OF THE
NORTHWEST TERRITORIES OF CANADA. CLOSER TO THE CENTRAL CONUS...A
NICE SHORTWAVE TROUGH WAS NOTED OVER SWRN MANITOBA. A 50+KT JET
STREAK EXTENDED ACROSS NRN WYOMING INTO SOUTH DAKOTA AND CENTRAL
MINNESOTA THIS MORNING. THIS FEATURE HAS LED TO THE DEVELOPMENT OF
SOME LIGHT RAIN SHOWERS ACROSS NORTHERN NEBRASKA AND SRN SOUTH
DAKOTA. THIS ACTIVITY HAS REMAINED VERY LIGHT THIS MORNING WITH ONLY
TRACE AMOUNTS TO A FEW HUNDREDTHS OF AN INCH REPORTED. AT THE
SURFACE...A TROUGH OF LOW PRESSURE EXTENDED FROM SERN MONTANA INTO
NERN COLORADO. FURTHER EAST...A COLD FRONT EXTENDED FROM FAR SWRN
NEBRASKA INTO THE SOUTHERN TEXAS PANHANDLE. TEMPERATURES SOUTH OF
THIS FEATURE WERE IN THE MID 80S TO 90S. WEST AND NORTH OF THE
FRONT...READINGS WERE IN THE 70S TO LOWER 80S. AS OF 2 PM
CDT...TEMPERATURES ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA...RANGED FROM 73 AT VALENTINE...TO 83 AT BROKEN BOW.
&&
.UPDATE...
ISSUED AT 807 PM CDT TUE MAY 20 2014
UPDATE TO THE FORECAST TO INCLUDE SEVERE WORDING. PLEASE REFER TO
WCN 162 FOR FURTHER DETAILS CONCERNING THE WATCH. CURRENTLY
WATCHING TWO AREAS OF CONVECTION...FIRST ACROSS THE WESTERN
PANHANDLE...AND THE SECOND IN NORTHEASTERN COLORADO. CONVECTION
ALLOWING MODELS INDICATE THAT THESE STORMS WILL CONTINUE
EASTWARD...POSSIBLY IMPACTING SOUTHWESTERN AND WESTERN PORTIONS OF
THE CWA THIS EVENING/OVERNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 312 PM CDT TUE MAY 20 2014
ALTOCUMULUS AND SPRINKLES BISECTING THE LBF CWA A RESULT OF REMNANTS
OF EARLIER CONVECTION AND WEAK MID LEVEL FORCING IN ASSOCIATION WITH
MID LEVEL INSTABILITY. SUBSEQUENT MID LEVEL FRONTOGENESIS HAS
DEVELOPED ACCORDING TO THE RAP FURTHER SOUTHEAST IS GENERATING SOME
ADDITIONAL CLOUD COVER ACROSS THE FAR EASTERN PORTION OF THE AREA.
FURTHER WEST...CONVECTION IS DEVELOPING NEAR THE LARAMIE RANGE IN WY
VERY SIMILAR TO THE WAY CONVECTION ALLOWING MODELS HAVE BEEN
SUGGESTING WITH EACH RUN. THE HRRR HAS THIS HANDLED WELL AND IN THE
ABSENCE OF SIGNIFICANT LARGE SCALE FORCING...THIS CONVECTION IS
PROGGED TO REMAIN ISOLATED AND DOES HAVE SOME POTENTIAL TO RETAIN
SUPERCELL STRUCTURE AS IT MOVES EAST INTO THE PANHANDLE THIS
EVENING...AGAIN ACCORDING TO THE HRRR AND ITS ENSEMBLE OF UPDRAFT
HELICITY. SHOULD THIS CLUSTER OF STORMS HOLD TOGETHER TONIGHT THERE
IS SOME SUPPORT IN THE SHORT RANGE MODELS FOR ELEVATED INSTABILITY
IN THE PANHANDLE. FURTHER SOUTH INTO SOUTHWEST NEB...SOME CONVECTION
DEVELOPING NEAR THE CO FRONT RANGE AND MODELS KEEP THIS PROGRESSING
EWD AS WELL SO PRECIP CHANCES ADDED TO THE SOUTHWEST OVERNIGHT.
HOWEVER...CONFIDENCE IN THIS SCENARIO IS ONLY MODERATE TO MAINTAIN
ITS STRUCTURE INTO THE SW DUE TO A LACK OF A LOW LEVEL JET.
OTHERWISE...LOW TEMPS IN THE UPPER 40S TO LOW 50S LOOKS GOOD BASED
ON LOW LEVEL MOISTURE PROFILE BEING MAINTAINED OVERNIGHT.
UPPER LEVEL RIDGE BUILDS INTO THE CENTRAL PLAINS AS THE SOUTHWESTERN
STATES UPPER LOW SLOWLY MOVES EWD. MAY BE SOME CONVECTIVE DEBRIS
ONCE AGAIN WED MORNING ESPECIALLY ACROSS WRN NEB. IN ADDITION...NAM
SUGGESTS POTENTIAL FOR STRATUS ALONG AND JUST EAST OF THE FRONTAL
POSITION IN FAVORED AREA OF UPSLOPE FLOW. THEN UPPER PV ANOMALY TO
MOVE INTO THE CENTRAL ROCKIES TOMORROW WHICH SHOULD ALLOW FOR A MUCH
BROADER COVERAGE OF CONVECTION AS THE UPPER FORCING SERVES TO
ENHANCE CONVERGENCE ALONG THE FRONT WHICH WILL BE LOCATED FROM NW KS
IN TO SERN WY. THIS DEVELOPMENT SHOULD BE DIURNALLY DRIVEN AND MAY
BE LIMITED DEPENDING ON ULTIMATE DEVELOPMENT OF STRATUS IN THE WEST.
TEMPS SHOULD BE COOLER WED THOUGH MODELS HAVE BEEN A LITTLE TOO COOL
IN THE SOUTH THE LAST COUPLE OF DAYS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 312 PM CDT TUE MAY 20 2014
WEDNESDAY NIGHT THROUGH TUESDAY...THE MAIN FORECAST
CHALLENGE WILL BE PRECIPITATION CHANCES IN THE MID RANGE AND
EXTENDED FORECAST. A PERSISTENT UPPER LEVEL TROUGH OF LOW PRESSURE
WILL REMAIN ANCHORED ACROSS THE WESTERN CONUS. PERSISTENT LOW LEVEL
MOISTURE WILL FLOW INTO WESTERN AND NORTH CENTRAL NEBRASKA THANKS TO
LOW LEVEL EASTERLY WINDS.
FOR WEDNESDAY NIGHT THROUGH FRIDAY...WEDNESDAY NIGHT...STRONG TO
SEVERE STORMS ARE EXPECTED TO BE ONGOING ACROSS NERN COLORADO AND
NWRN KS INVOF OF THE SURFACE FRONTAL BOUNDARY. WITH SSWRLY STEERING
WINDS CONTINUING ACROSS THE HIGH PLAINS...ACTIVITY WILL LIFT NWD
INTO THE FORECAST AREA DURING THE EVENING HRS. THERE WILL REMAIN A
LARGE HAIL THREAT MAINLY ACROSS FAR SWRN NEBRASKA AND THE SERN
NEBRASKA PANHANDLE WHICH WILL BE IN CLOSER PROXIMITY TO THE FRONTAL
BOUNDARY. FARTHER NORTH...HAIL SIZE SHOULD DECREASE ACROSS THE
WESTERN SANDHILLS AND I80 CORRIDOR...HOWEVER SMALL HAIL WILL REMAIN
A THREAT GIVEN THE DEGREE OF ELEVATED INSTABILITY EXPECTED
OVERNIGHT. BOTH THE GFS AND NAM SOLNS THIS MORNING...ARE INDICATIVE
OF MCS DEVELOPMENT WEDS EVENING...WHICH WILL TRAVERSE THE CWA
OVERNIGHT. THIS SEEMS PLAUSIBLE GIVEN THE 30 TO 40 KT H85 WINDS
ACROSS THE SOUTHERN AND CENTRAL CWA OVERNIGHT WEDS NIGHT. INHERITED
FORECAST HAD POPS IN THE 30 TO 50 PERCENT RANGE FROM NORTH TO SOUTH
WEDS NIGHT WHICH REMAINS ON TRACK GIVEN THE LATEST STATISTICAL
GUIDANCE. A SIMILAR CONVECTIVE SETUP WILL COMMENCE FOR LATE THURSDAY
INTO THURSDAY NIGHT. A FRONTAL BOUNDARY WILL BE STALLED OUT OVER
NORTHEASTERN COLORADO AND NWRN KS. WITH HEATING AND THE ARRIVAL OF AN
UPPER LEVEL SHORTWAVE...THUNDERSTORMS WILL INITIATE DURING THE LATE
AFTERNOON HRS INVOF THE FRONT. THERE ARE SOME MODEL DIFFERENCES IN
THE LOCATION OF THE FRONTAL BOUNDARY THURSDAY AFTERNOON WITH THE NAM
SOLN BEING THE FARTHEST SOUTH. WITH MCS DEVELOPMENT PROBABLE
TOMORROW NIGHT...JUST WHERE THIS BOUNDARY WILL LIE DOWN THURSDAY
WILL BE HARD TO PINPOINT...AS WILL BE THE SEVERE THREAT.
HOWEVER...ANOTHER ROUND OF SCATTERED THUNDERSTORMS IS POSSIBLE
THURSDAY NIGHT AS ACTIVITY ALONG THE FRONT LIFTS NORTH INTO THE
FORECAST AREA. FAVORABLE CONDITIONS...BOTH ALOFT AND AT THE SURFACE
FOR PRECIPITATION...WILL CONTINUE INTO FRIDAY. PERSISTENT SWRLY FLOW
ALOFT...A FRONTAL BOUNDARY ACROSS SWRN NEBRASKA AND EASTERLY AND
SERLY WINDS IN THE BOUNDARY LAYER ARE EXPECTED FRIDAY INTO FRIDAY
NIGHT. THE THREAT FOR SEVERE STORMS FRIDAY AFTERNOON AND FRIDAY
NIGHT WILL HINGE ON THE LOCATION OF THE SURFACE FRONTAL
BOUNDARY...WHICH ATTM IS EXPECTED TO LIE EITHER OVER SWRN NEBRASKA
OR OFF TO THE SW IN NERN COLORADO AND NWRN KS. LIKE WEDNESDAY AND
THURSDAY...SCATTERED THUNDERSTORMS WILL LIFT NORTH AND
NORTHEAST...FROM THE FRONTAL BOUNDARY INTO WESTERN AND NORTH CENTRAL
NEBRASKA FRIDAY EVENING AND FRIDAY NIGHT AND CHANCE POPS WERE
CONTINUED.
FRIDAY NIGHT THROUGH TUESDAY...AN UPPER LEVEL TROUGH WILL PERSIST
ACROSS THE INTERMOUNTAIN WEST FRIDAY NIGHT THROUGH SUNDAY
NIGHT...BEFORE LIFTING ACROSS THE CENTRAL PLAINS ON MONDAY. THE
THREAT FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE
WEEKEND...MAINLY DURING THE LATE AFTERNOON AND EVENING HOURS AS
ABUNDANT LOW LEVEL MOISTURE REMAINS IN PLACE ACROSS THE FORECAST
AREA. ON MONDAY AND MONDAY NIGHT...THE MAIN UPPER LEVEL LOW WILL
LIFT NORTHEAST INTO THE CENTRAL PLAINS...TRACKING INTO THE LOWER
MISSOURI VALLEY ON TUESDAY. PRECIPITATION CHANCES WILL CONTINUE INTO
MONDAY...WITH DRIER CONDS EXPECTED MONDAY NIGHT INTO TUESDAY. HIGHS
WILL GENERALLY BE IN THE 70S...WITH 80S POSSIBLE NEXT
TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1257 AM CDT WED MAY 21 2014
FOR THE KVTN AND KLBF 06Z TAFS...SHOWERS WITH THE OCCASIONAL STORM
WILL CONTINUE TO WORK EAST NORTHEAST ACROSS THE EASTERN PANHANDLE
AND ADJACENT SAND HILLS REGION OF WESTERN NEBRASKA EARLY THIS
MORNING. THIS ACTIVITY SHOULD PERSIST INTO THE PRE-DAWN HOURS WITH
ADDITIONAL CONVECTIVE DEVELOPMENT NOTED FROM REGIONAL RADARS OFF THE
HIGH PLAINS OF EASTERN WYOMING AND COLORADO. IF A STORM WERE TO
PASS OVER A TERMINAL...THEN BRIEF MVFR CONDITIONS WOULD BE
POSSIBLE. LATEST GUIDANCE FROM CONVECTIVE ALLOWING MODELS INDICATE
HOWEVER THAT THIS ACTIVITY SHOULD NOT IMPACT EITHER KVTN OR KLBF.
OTHERWISE STORMS ARE POSSIBLE ONCE AGAIN LATE IN THE TAF
PERIOD...ONCE AGAIN MAINLY ACROSS WESTERN AND SOUTHWEST NEBRASKA.
ATTM CONFIDENCE IS NOT ENOUGH FOR A MENTION IN THE OFFICIAL TAF
FORECAST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JACOBS
SYNOPSIS...CLB
SHORT TERM...JWS
LONG TERM...CLB
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
321 AM CDT WED MAY 21 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
CLOUDS AND TEMPERATURES WILL BE THE MAIN ISSUE FOR THE PERIOD.
WEST TO NORTHWESTERLY FLOW ALOFT WILL CONTINUE AS THE UPPER TROUGH
FROM YESTERDAY PULLS OFF TO THE EAST. THERE HAS BEEN PLENTY OF
CLOUDS BEHIND THE COLD FRONT THAT MOVED THROUGH...WITH THE ENTIRE
CWA SEEING MOSTLY CLOUDY SKIES THIS MORNING. RUC13 925-850MB RH WHICH
HAS A GOOD HANDLE ON CLOUDS DOES NOT REALLY SEE MUCH DECREASE
UNTIL THE MIDDLE OF THE DAY. THINK THAT CLOUDS WILL CONTINUE FOR
AT LEAST PART OF THE MORNING BEFORE HIGH PRESSURE MOVES IN THIS
AFTERNOON. THINK THAT THERE SHOULD BE SOME SUN LATE IN THE DAY AND
TEMPS WILL STILL GET INTO THE 60S.
TONIGHT...WE SHOULD CONTINUE TO SEE DECREASING CLOUDS AND WINDS
WILL BECOME LIGHT AS THE CENTER OF THE HIGH SETTLES OVER THE AREA.
DEW POINTS WILL DROP DOWN TO NEAR 40 DEGREES AND LOWS WILL BE
MAINLY IN THE LOW TO MID 40S ACROSS THE AREA. WILL HAVE TO WATCH
FOR SOME PATCHY FOG FORMATION BUT NOT CONFIDENT ENOUGH TO INCLUDE
IN THE GRIDS AT THIS POINT. THE UPPER RIDGE WILL CONTINUE TO BUILD
INTO THE PLAINS ON THURSDAY. LIGHT SOUTHEAST WINDS AND SOME SUN
WILL HELP TEMPS GET TO NEAR 70 DEGREES.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE UPPER RIDGE CONTINUES TO
BUILD INTO CANADA...AND MODELS SHOW SOME INDICATION OF SOME FAIRLY
WEAK WAVES RIDING ALONG THE BACK SIDE OF THE RIDGE. THERE COULD BE
SOME CONVECTIVE ACTIVITY WITH THESE WAVES...ALTHOUGH MODELS HAVE
MOST OF PRECIP TO OUR WEST AT THIS POINT. GIVEN THE UPPER LEVEL
FLOW SOME CONVECTION CLIPPING OUR NORTHWESTERN COUNTIES WILL BE
POSSIBLE...SO INCLUDED SOME LOW POPS THURSDAY NIGHT AND FRIDAY.
ACTIVITY WILL BE FURTHER EAST FRIDAY NIGHT AS THE RIDGE AXIS
SHIFTS A BIT EASTWARD AND MOISTURE TRANSPORT KICKS IN. INCLUDED
POPS BEYOND THE DEVILS LAKE AREA BUT KEPT THEM PRETTY LOW FOR NOW.
TEMPS THROUGH THE END OF THE WORK WEEK WILL BE WARMING UP TO ABOVE
NORMAL VALUES WITH HIGHS IN THE MID TO UPPER 70S.
FOR SATURDAY INTO SUNDAY...UPPER LEVEL RIDGE AXIS HAS SHIFTED OVER
THE AREA...WITH WARMER TEMPERATURES EXPECTED INTO THE MID TO UPPER
70S. A SERIES OF DISTURBANCES LOOK TO RIDE OVER THE RIDGE AXIS
DECREASING STABILITY AND ALLOWING FOR BETTER CHANCES FOR SHOWERS AND
TSTMS. OTHERWISE...FOR MONDAY AND TUESDAY...LOOK FOR CONTINUED WARM
TEMPS WITH SHOWERS DECREASING AS SFC HIGH PRESSURE SETTLES ACROSS
THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1142 PM CDT TUE MAY 20 2014
HAVE LOWERED CIGS AND DELAYED CLEARING UNTIL LATE AFTN FOR ND
SITES AND EARLY AFTN FOR MN SITES TOMORROW. LOWEST CIGS WILL BE
OVER NWRN MN AT TVF...WITH IFR CIGS THROUGH MID MORNING...AND
DROPPING INTO LOWER MVFR RANGE AT BJI BY 12Z. MVFR CIGS FROM THE
NORTHERN VALLEY THROUGH THE DEVILS LAKE AREA WILL FINALLY BEGIN TO
CLEAR OUT...FROM WEST TO EAST...BY MID MORNING AND THE CLEAR LINE
WILL WORKS ITS WAY ACROSS MN THROUGHOUT THE DAY...REACHING BJI BY
ABOUT 21Z.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1142 PM CDT TUE MAY 20 2014
.UPDATE...
ISSUED AT 1142 PM CDT TUE MAY 20 2014
REMOVED POPS FOR FAR NORTHEAST AND INCREASED SKY COVER IN LINE
WITH RUC LOW LEVEL MOISTURE FIELD. NO OTHER CHANGES TO THIS FORECAST.
UPDATE ISSUED AT 924 PM CDT TUE MAY 20 2014
FORECAST CHALLENGE FOR TONIGHT WILL BE SKY AND OVERNIGHT LOWS. LOW
CLOUDS OVER MUCH OF N CNTRL ND DID NOT BREAK UP AS MUCH AS PREV
THOUGHT...AND WILL INCREASE SKY ACROSS AREA GRADUALLY OVERNIGHT
TONIGHT. RUC 925-850 LYRD RH IDEA SEEMS MOST LIKELY...WITH OVC
SKIES SPREADING ACROSS AREAS THAT ARE CURRENTLY CLEAR AND NW NOT
CLEARING OUT UNTIL MID MORNING TOMORROW. WILL HOWEVER REMOVE POPS
FOR THE NIGHT AS RADAR UNIMPRESSIVE.
UPDATE ISSUED AT 643 PM CDT TUE MAY 20 2014
MAIN ISSUES FOR THIS UPDATE WILL BE PROBABILITY FOR PRECIP ACROSS
THE NORTH AND ADJUSTMENTS TO SKY GRIDS.
CANADIAN RADARS SHOWING SHOWERS ROTATING AROUND THE UPPER LOW
BEGINNING TO DRY UP AS THEY APPROACH SOUTHERN AND SOUTHEASTERN
MANITOBA. WILL REMOVE POPS THROUGH 06Z AND KEEP LOW CHANCE POPS
FOR LAKE OF THE WOODS AFT 06Z. MAY PULL PRIOR TO NEXT UPDATE IF
NOTHING BEGINS TO REDEVELOP...HOWEVER WILL REMOVE MENTION OF
THUNDER. FOR SKY...MUCH OF SOUTHEASTERN HALF OF CWA IS CLEAR OR
CLEARING IN THE CELLULAR CU OVER EASTERN ZONES. WILL HAVE MOSTLY
CLEAR WORDING THROUGH 06Z...WITH INCREASED CLOUD COVER AS CLOUDS
OVER THE DEVILS LAKE BASIN BEGIN TO FILL IN CLEAR AREAS. LOOKS
LIKE THIS WILL HOLD TOGETHER LONG ENOUGH TO KEEP NORTHEASTERN
PORTION OF CWA MOSTLY CLOUDY TOMORROW...WHICH WILL ALSO IMPACT
AVIATION (SEE DISCUSSION BELOW).
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 315 PM CDT TUE MAY 20 2014
FORECAST CHALLENGE CONCERNS LOW END PCPN CHANCES AND TEMPERATURES.
MODELS IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD AND WILL USE
BLEND.
SURFACE/UPPER LOW WILL CONTINUE TO PROPAGATE EAST ALONG THE
MN/CANADIAN BORDER OVERNIGHT. CU FIELD EXPANDING SOUTHWARD WITH
THICKEST CLOUD COVER ALONG A DVL-ROX LINE. AIRMASS NOT VERY
UNSTABLE UNDER MID LEVEL COOLER AIR WITH NIL CAPE. A FEW SHOWERS
APPROACHING THE N CENTRAL ND BORDER AREA OTHERWISE ANY RAIN STILL
FARTHER NORTH INTO CANADA. FOR THIS DO NOT HAVE A LOT OF
CONFIDENCE ON SHRA POTENTIAL LATER THIS AFTERNOON INTO THE
EVENING. MODELS FOR THE MOST PART KEEPING ANY SHRA ACTIVITY
HUGGING THE INTERNATIONAL BORDER. WILL MAINTAIN SOME SLIGHT/LOW
CHANCES BUT AGAIN CONFIDENCE NOT HIGH. COLD ADVECTION WILL PUSH
THROUGH THE FA TONIGHT SO EXPECT MINIMUMS GENERALLY IN THE 40S.
LOW LEVEL COLD POOL OVER FA TOMORROW MORNING WILL SHIFT EAST
ACROSS MN DURING THE DAY WITH SOME WARM ADVECTION FROM THE VALLEY
WEST. NOT A GREAT DEAL OF MIXING EXPECTED WITH SURFACE HIGH
OVERHEAD. CONVECTIVE TEMPERATURES INITIALLY LOW BUT RAISE DURING
THE DAY SO DO EXPECT SOLAR. FEEL OPERATIONAL MODELS OVERDONE ON
QPF WEDNESDAY AFTERNOON SO KEPT FORECAST DRY. OVERALL EXPECT
TEMPERATURES AROUND 5 DEGREES BLO SEASONAL NORMS.
LIGHT WINDS AND SKC SHOULD ALLOW TEMPERATURES TO DROP OFF INTO THE
LOW TO MID 40S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 315 PM CDT TUE MAY 20 2014
HIGH SHIFTS SLIGHTLY EAST THURSDAY WITH COLUMN CONTINUING TO WARM.
MIXING WILL STILL REMAIN LIGHT HOWEVER WITH SOLAR EXPECT
TEMPERATURES CLOSER TO NORMAL.
WITH WARM ADVECTION AND WARMER COLUMN IN PLACE MINIMUM TEMPERATURES
NOT AS COOL THURSDAY NIGHT. MAIN MOISTURE TRANSPORT AND RELATED
INSTABILITY WILL REMAIN WELL TO OUR WEST OVER THE WESTERN DAKOTAS.
LOW CONFIDENCE ON EASTWARD EXTENT OF ANY LATE NIGHT/EARLY MORNING
RESIDUAL PCPN SO LIMITED POPS TO THE FAR WESTERN FA.
MIXING AND SURFACE MOISTURE FLUX INCREASES FRIDAY. HOW WARM WE GET
WILL DEPEND ON DEGREE OF CLOUD COVER BUT OVERALL TEMPERATURES
SHOULD BE AT OR A LITTLE ABOVE AVERAGE. SOME INSTABILITY WORKS
INTO THE WESTERN FA HOWEVER WITH LACK OF LOW LEVEL FORCING FEEL FA
FOR THE MOST PART WILL BE DRY.
THE FRIDAY NIGHT THROUGH TUESDAY PERIOD FINALLY HAS A STRING OF DAYS
WITH WARMER TEMPERATURES. ALONG WITH THESE WARMER TEMPERATURES WILL
ALSO FEATURE A RETURN TO SOME HUMIDITY. RIDGING OVER THE CENTRAL
PART OF THE COUNTRY WILL SLOWLY BE REPLACED BY SOUTHWEST FLOW WITH A
CUTOFF LOW KICKING OUT INTO THE CENTRAL PLAINS. HIGH TEMPS EACH DAY
SHOULD RANGE IN THE UPPER 70S TO AROUND 80. UNFORTUNATELY THE
COMBINATION OF HEAT HUMIDITY AND SOUTHWEST FLOW MEANS AN INCREASED
CHANCE FOR SHOWERS AND TSTMS. ESSENTIALLY EACH DAY CARRIES SOME
MENTION OF PCPN BUT REALISTICALLY THERE WILL BE SOME DRY PERIODS.
JUST HARD TO NAIL DOWN THIS FAR OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1142 PM CDT TUE MAY 20 2014
HAVE LOWERED CIGS AND DELAYED CLEARING UNTIL LATE AFTN FOR ND
SITES AND EARLY AFTN FOR MN SITES TOMORROW. LOWEST CIGS WILL BE
OVER NWRN MN AT TVF...WITH IFR CIGS THROUGH MID MORNING...AND
DROPPING INTO LOWER MVFR RANGE AT BJI BY 12Z. MVFR CIGS FROM THE
NORTHERN VALLEY THROUGH THE DEVILS LAKE AREA WILL FINALLY BEGIN TO
CLEAR OUT...FROM WEST TO EAST...BY MID MORNING AND THE CLEAR LINE
WILL WORKS ITS WAY ACROSS MN THROUGHOUT THE DAY...REACHING BJI BY
ABOUT 21Z.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...SPEICHER
SHORT TERM...VOELKER
LONG TERM...GODON/VOELKER
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
149 AM EDT WED MAY 21 2014
.SYNOPSIS...
WARM FRONT LIFTING NORTHEAST TONIGHT. WARMER AND MORE HUMID AIR WITH
ROUNDS OF CONVECTION INTO THURSDAY MORNING. COLD FRONT SAGS SOUTH
THURSDAY. DRIER FRIDAY INTO SUNDAY. WARM...HUMID MEMORIAL DAY.
&&
.NEAR TERM /THROUGH TODAY/...
MADE SOME MINOR ADJUSTMENTS AND REFINEMENTS TO THE TIMING ON
PRECIPITATION PRIMARILY USING THE HRRR TIMING FOR THE EVENING AND
NAM TIMING FOR LATER TONIGHT AND TOMORROW. THINGS STILL LOOK GOOD
FOR THUNDERSTORM SET UP WEDNESDAY AFTERNOON/EVENING.
PREVIOUS DISCUSSION FOLLOWS...
NEAR 18Z...HAVE WARM FRONT CMH OHIO TO CRW WV
TO NR LNP VA. NICE DIFFERENCE IN CLOUD STRUGGLE ON EITHER SIDE OF
THE FRONT. MORE CELLULAR IN WARM SECTOR IN EASTERN KY.
WILL STILL TRY TO LEAVE SOUTHERN COUNTIES DRY TONIGHT...FIGURING MID
LEVEL CAPE WILL HOLD...DESPITE THE LATE AFTERNOON HEATING AND
INCREASING DEW POINTS.
RAP MODEL INDICATES SOME WEAK 500 MB VORT MAX MOVING ESE THROUGH
EASTERN OHIO INTO NORTH CENTRAL WV 03Z TO 05Z TONIGHT. SO NO BIG
CHANGES IN LEAVING SOME CHANCE POPS THERE TONIGHT. THOUGH...NOT
FIGURING ON STRONG CONVECTION. MAY BE A LULL IN NORTHERN COUNTIES
OVERNIGHT...BUT WITH WNW FLOW ALOFT...HELD ONTO CHANCE POPS FOR NOW.
STILL FIGURING ON A CONVECTION COMPLEX FORMING IN THE MIDWEST
TONIGHT AND RIDING ESE DURING THE 06Z TO 12Z TIME FRAME. WILL HOLD
ONTO INCREASING POPS IN OUR NORTHERN COUNTIES FOR A WEAKENING FORM
OF THAT COMPLEX POSSIBLY REACHING THOSE COUNTIES TOWARD DAWN. SLOWED
DOWN THAT INCREASE BY A FEW HOURS...BUT NEED TO HAVE COMPLEX FORM
BEFORE ANY MAJOR ADJUSTMENT ON TIMING AND HOW FAR SOUTH.
DURING WEDNESDAY...WHAT IS LEFT OF THAT MORNING COMPLEX AND ITS
DEBRIS CLOUDS COULD AFFECT TIMING THE NEW CONVECTION THAT DEVELOPS
ON WEDNESDAY. SO DID NOT WANT TO GET TOO FANCY AT THIS DISTANCE IN
TIME. OVERALL...WE ARE STILL GRADUALLY SHIFTING THE HIGHER POPS
SOUTH DURING THE LATE AFTERNOON. 700 MB MID LEVEL FLOW INCREASES TO
ABOUT 45 KNOTS. THINKING WIND WOULD BE THE HIGHER THREAT ASSOCIATED
WITH THE STRONGER THUNDERSTORMS.
TEMPERATURE WISE...WENT A SHADE COOLER TONIGHT IN THE SOUTH
TONIGHT...FIGURING ON LESS CLOUDS AND THE WIND SUBSIDING A BIT.
NO MAJOR CHANGE IN MAXIMUM TEMPS ON WEDNESDAY SINCE SO DEPENDENT ON
CONVECTION TIMING.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
CONVECTIVELY ACTIVE AT START OF PERIOD WITH COLD FRONT WELL
UPSTREAM...AND WARM ADVECTION SHEAR BENEATH NW FLOW ALOFT. CAPE
VALUES ARE FCST AS HIGH AS 3 KJ/KG OVER THE MID OHIO VALLEY ON DEW
POINTS INTO THE LOWER AND MID 60S...ALONG WITH PW VALUES UP TO 1.5
IN. 40 KT MID LEVEL FLOW SUGGESTS FAST MOVING STORMS SO FLOODING
SHOULD NOT AMOUNT TO MORE THAN BRIEF LOCALIZED HIGH WATER...LEAVING
WIND DAMAGE AS THE MAIN THREAT. FLOW REGIME COULD ALSO SUPPORT AN
ORGANIZED CONVECTIVE COMPLEX MOVING E-SE.
ACTIVITY COULD LAST INTO THE NT AS SOME INSTABILITY IS MAINTAINED
AHEAD OF THE COLD FRONT ADVANCING FROM THE NW...WITH DRIER AIR
INFILTRATING THE AREA LATE WED NT AND THU. COULD THEREFORE STILL
SEE THUNDERSTORMS SRN ZONES THU BUT THE SEVERE THREAT SHOULD BE
DIMINISHED.
HIGH PRESSURE SETTLES IN BENEATH NW FLOW ALOFT THU NT AND FRI.
NO MAJOR TEMPERATURES...WITH MET AND / OR GFS BASED MOS BLENDED IN
IN MOST CASES. INHERITED PACKAGE SHOWED MORE OF A BAROCLINIC ZONE
THAN MOS GUIDANCE SUGGESTS BUT PRESERVED GIVEN MODEL GUIDANCE AS
THIS IS STILL SUGGESTED IN THE MODEL LOW LEVEL THERMAL FIELDS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE RULES AT THE SFC THIS PERIOD WHILE UPPER LEVEL NW FLOW
GIVES WAY TO RIDGING. EXPECT A STRETCH OF DRY WEATHER WITH
MODERATING TEMPERATURES THROUGH THE MEMORIAL DAY WEEKEND. DIURNAL
THUNDERSTORMS START TO BECOME A FACTOR MON OR TUE...HAVE A SLIGHT
CHANCE FOR AFTERNOON THUNDERSTORMS IN THE MOUNTAINS MON
AFTERNOON...AND THEN A CHC EVERYWHERE TUE AFTERNOON.
INHERITED TEMPERATURES LOOKED GOOD...WITH MEX AND / OR WPC BLENDED
IN HERE AND THERE...ALONG WITH CONSENSUS ALL AT THE END. SOME OF
THE GUIDANCE WAS LOWER BUT DID NOT SEE FIT TO LOWER MUCH IN THIS
PATTERN.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
06Z WEDNESDAY THRU 06Z THURSDAY...
THIS WHOLE FORECAST DEPENDS ON THUNDERSTORM COMPLEXES AHEAD OF A
COLD FRONT WHICH DOES NOT ENTER AREA UNTIL AFTER THIS PERIOD.
06Z-15Z. EXPECT ONE COMPLEX NORTHERN INDIANA/NORTHWEST OHIO TO MOVE
EAST SOUTHEAST JUST SOUTH OF WARM FRONT...WITH MOST OF COMPLEX
STAYING JUST NORTH OF AREA. WE DO HAVE SOUTHERN EDGE OF COMPLEX
CLIPPING NORTH CENTRAL AND NORTHEAST WEST VIRGINIA 10Z-15Z...DRY
ELSEWHERE. OUTSIDE OF CONVECTION...GENERALLY VFR CEILINGS AOA 8000
FEET SOUTH AND AROUND 4000 FEET NORTH.
AFTER 15Z...EXPECT ANOTHER THUNDERSTORM COMPLEX TO FORM OUT AHEAD OF
COLD FRONT BY 18Z OVER CENTRAL OHIO...THEN DROPPING SOUTHEAST
THROUGH 00Z INTO SOUTHERN SECTIONS OF AREA. A FEW STORMS COULD BE
SEVERE. AGAIN...OUTSIDE OF CONVECTION CEILINGS AOA 4000 FEET.
AFTER 00Z...EXPECT POST THUNDERSTORM COMPLEX MVFR CEILINGS TO FORM
ESPECIALLY NORTH...WITH DECREASED CHANCES FOR CONVECTION.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM TODAY...LOW TONIGHT.
ALTERNATE SCENARIOS: OCCURRENCE AND TIMING OF CONVECTION...ESPECIALLY
THIS AFTERNOON...ALONG WITH POST COMPLEX MVFR CEILINGS TONIGHT
DEPEND ON THE ACTUAL EVOLUTION OF THE COMPLEXES.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE WED 05/21/14
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H M H H H H H H
PKB CONSISTENCY H H H H H H H H M H H H
CKB CONSISTENCY H H H H H M H H H H H H
AFTER 06Z THURSDAY...
IFR CONDITIONS IN CONVECTION COMPLEXES THROUGH MUCH OF WEDNESDAY
NIGHT...THEN LINGERING IFR IN LOW CLOUDS AND LIGHTER SHOWERS NEAR THE COLD
FRONT 12Z TO 18Z THURSDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/TRM
NEAR TERM...KTB/JR
SHORT TERM...TRM
LONG TERM...TRM
AVIATION...JMV
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
143 AM EDT WED MAY 21 2014
.SYNOPSIS...
A WARM AND MOIST AIRMASS WILL REMAIN IN PLACE OVER THE REGION
TONIGHT. A COLD FRONT WILL PUSH THROUGH THE REGION TOMORROW AND
TOMORROW NIGHT...WITH DRIER AND SLIGHTLY COOLER AIR MOVING OVER
THE OHIO VALLEY FOR THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
CONVECTION ACROSS NORTHERN ILLINOIS AND NORTHWEST INDIANA WILL
LIKELY CONTINUE THROUGH THE NIGHT AND MOVE EAST OR EAST
SOUTHEAST. THIS WILL PUT IT ALONG OR CLOSE TO THE FAR NORTHERN
COUNTIES IN THE FORECAST AREA. SO HAVE CONTINUED TO CONCENTRATE
HIGHER POPS THERE. THERE REMAINS SOME POTENTIAL FOR STRONGER
STORMS INTO WEST CENTRAL OHIO. HOWEVER INSTABILITY WILL DIMINISH A
BIT BY THE TIME STORMS REACH THAT AREA AND BASED ON RAP SOUNDINGS
THE STORMS MAY BE ELEVATED AT THAT POINT. BUT WILL CONTINUE TO
MONITOR THIS POTENTIAL. MEANWHILE THE SOUTHERN COUNTIES SHOULD
REMAIN DRY. FORECAST TEMPERATURES LOOK ON TRACK WITH LOWS IN THE
LOWER TO MID 60S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
LEFTOVER MORNING CONVECTION AND CLOUD DEBRIS WILL END UP PLAYING A
BIG ROLE IN THUNDERSTORM POTENTIAL FOR WEDNESDAY...WITH AN
OTHERWISE-FAVORABLE SETUP FOR STRONG STORMS.
THE WEAK SURFACE LOW WILL GRADUALLY DRIFT EAST ACROSS THE LOWER
PENINSULA OF MICHIGAN ON WEDNESDAY...WITH A COLD FRONT STRETCHING
TO THE SOUTHWEST INTO THE MIDDLE MISSISSIPPI VALLEY. THOUGH THE
FRONTAL BOUNDARY WILL NOT MAKE IT INTO THE ILN CWA UNTIL LATE
WEDNESDAY NIGHT...THE REGIME AHEAD OF THE FRONT WILL BE MOIST AND
UNSTABLE...AND THIS IS WHERE CONVECTION IS EXPECTED TO DEVELOP.
INSTABILITY WILL BE IMPACTED THE GREATEST BY REMNANTS FROM THE
EARLY WEDNESDAY MORNING ACTIVITY...A NEARLY-IMPOSSIBLE QUESTION
TO ANSWER UNTIL THE SITUATION TONIGHT PLAYS OUT. HOWEVER...THE
MOST LIKELY SCENARIO SEEMS TO FAVOR INSTABILITY GROWING THE MOST
IN THE SOUTHERN AND SOUTHWESTERN PORTIONS OF THE ILN CWA...WITH
THE GREATEST IMPEDING TO INSOLATION IN CENTRAL OHIO. HIGH-RES
MODELS ARE NOT KEYING IN ON MUCH STORM DEVELOPMENT IN THE NORTHERN
PORTIONS OF THE CWA...BUT SHOW A GOOD SIGNAL FOR DIURNALLY-TIMED
CONVECTION FIRING OFF IN THE SOUTHERN HALF OF THE FORECAST
AREA...IN AN AREA WHERE CAPE VALUES OF 2000-2500 J/KG APPEAR
POSSIBLE (AS LONG AS THE SUN CAN HEAT THINGS UP FOR A WHILE). WNW
WIND SHEAR IS COMFORTABLY IN THE MODERATE AREA OF THE
SCALE...WHICH WILL SUPPORT STORM ORGANIZATION. ALTHOUGH THERE IS
A LITTLE BIT OF TURNING (WSW AT THE SURFACE TO WNW AT
6KM)...OVERALL THIS SCENARIO SEEMS TO PRIMARILY SUPPORT A WIND AND
HAIL THREAT (PERHAPS WITH SOME DISCRETE AND ORGANIZED UPDRAFTS).
UNLESS CONVECTION COMPLETELY OVERTURNS THE ATMOSPHERE...A THREAT
FOR THUNDERSTORMS MAY CONTINUE INTO THE OVERNIGHT HOURS...WITH
SOME LINGERING INSTABILITY AHEAD OF THE COLD FRONT.
POPS WERE KEPT IN THE 20-30 PERCENT RANGE THROUGH MUCH OF THE DAY
ON WEDNESDAY...BUT RAMPED UP TO LIKELY IN THE SOUTHERN CWA DURING
THE AFTERNOON AND EVENING. POPS WERE DROPPED TO ZERO AFTER 09Z.
HIGH PRESSURE OVER THE UPPER MIDWEST WILL GRADUALLY SLIDE
EASTWARD...BEGINNING TO INFLUENCE THE OHIO VALLEY ON THURSDAY. THE
AIR MASS MOVING IN WILL BE SIGNIFICANTLY DRIER AND SOMEWHAT
COOLER...WITH HIGHS DROPPING 5-10 DEGREES FROM WEDNESDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL ALLOW FOR DRY CONDITIONS THROUGH THE WEEKEND.
COOL NORTHERLY FLOW WILL KEEP TEMPERATURES IN THE UPPER 60S TO LOW
70S ON FRIDAY. A RIDGE WILL GRADUALLY WORK INTO THE REGION THROUGH
THE WEEKEND WITH TEMPERATURES WARMING EACH DAY. BY MONDAY HIGH
TEMPERATURES ARE EXPECTED TO BE IN THE 80S ACROSS THE ENTIRE FA.
PRECIPITATION LOOKS TO HOLD OFF UNTIL TUESDAY. THE GFS IS TRYING TO
DEVELOP A FEW THUNDERSTORMS ACROSS NW PORTIONS OF THE FA ON MONDAY
HOWEVER DECIDED TO GO WITH A DRY FORECAST ON MONDAY AT THIS TIME.
ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE DURING THE DAY
ON TUESDAY. ANY THUNDERSTORM ACTIVITY IS EXPECTED TO DISSIPATE
DURING THE EVENING HOURS WITH THE LOSS OF DAYTIME HEATING.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
THUNDERSTORMS ARE CONTINUING TO PUSH EAST ACROSS NORTHERN INDIANA
AND ARE NOW WORKING INTO NORTHWEST OHIO EARLY THIS MORNING. THESE
STORMS HAVE HAD A BIT OF A SOUTHEASTWARD PROPAGATION TO THEM...BUT
AIRMASS FARTHER SOUTH ACROSS OUR AREA IS MORE STABLE. AS A
RESULT...THINK THESE WILL GENERALLY REMAIN TO THE NORTH OF THE TAF
SITES THROUGH THE PRE DAWN HOURS. THAT BEING SAID...THE LATEST HI-RES
MODELS ARE IN DECENT AGREEMENT SHOWING SOME DEVELOPMENT FROM AN
OUTFLOW OF THE CURRENT ACTIVITY...DROPPING SOUTH ACROSS OUR AREA
LATER THIS MORNING INTO THIS AFTERNOON. HOW WIDESPREAD THIS
ACTIVITY WILL BE IS STILL SOMEWHAT IN DOUBT THOUGH SO WILL CONTINUE
TO COVER THE THREAT WITH A VCTS AT THE NORTHERN TAF SITES LATER
THIS MORNING. AS WE BEGIN TO DESTABILIZE THROUGH THIS
AFTERNOON...EXPECT COVERAGE TO INCREASE AS THE BOUNDARY SAGS SOUTH
TOWARD THE OHIO RIVER. THIS WILL LIKELY LEAD TO A BETTER CHANCE OF
THUNDERSTORMS AT THE SOUTHERN TAF SITES FOR THIS AFTERNOON INTO THIS
EVENING. HAVE KEPT CIGS AND VSBYS VFR...BUT BRIEF PERIODS OF MVFR
OR LOWER CIGS/VSBYS WILL BE POSSIBLE WITH ANY STORMS THAT AFFECT
THE TAF SITES.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...
SHORT TERM...HATZOS
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
156 AM EDT WED MAY 21 2014
.SYNOPSIS...
A WARM FRONT WILL SLIDE FROM THE OHIO VALLEY INTO CENTRAL
PENNSYLVANIA TONIGHT AND WEDNESDAY. A COLD FRONT WILL THEN MOVE
THROUGH ON THURSDAY...BRINGING COOLER AIR BACK TO THE REGION. THE
EXTENDED FORECAST INDICATES A GRADUAL WARMING TREND BEGINNING THIS
WEEKEND DESPITE SOME SHOWERS LINGERING IN THE POST- FRONTAL
NORTHWEST FLOW.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
130 AM UPDATE...
MIGHT AS WELL JUST BLOCK COPY PASTE FROM THE EARLIER DISC.
HOWEVER...THE STORMS MOVING INTO NWRN COS ARE MUCH STRONGER THAN
EARLIER - DESPITE STILL BEING ELEVATED/DETACHED FROM THE SURFACE.
THESE ALSO SEEM TO HAVE BETTER UPPER SUPPORT AND SHOULD LAST
LONGER AND DROP MORE RAIN. THEREFORE...HAVE FURTHER BUMPED POPS
UP AND EXTENDED THEM INTO THE SERN COS LATER TONIGHT. LATEST RUC
AND HRRR PROGS SUPPORT THIS MOVE. DEWPOINTS STILL IN THE 40S OVER
THE LAURELS AND FAR NERN COS WHERE NO RAIN HAS YET FALLEN.
PREV...
THE BACK EDGE OF THE CONVECTION SEEMS TO BE ON THE LAKE ERIE
SHORE-LINE NOW...MAKING A BEE-LINE FOR NW PA WITH STILL AN
OCCASIONAL LIGHTNING STRIKE STILL BEING DISPLAYED.
HOWEVER THE 23Z HRRR KEEPS THIS ZONE ACTIVE INTO THE OVERNIGHT AS
THE WARM FRONT PROGRESSES SLOWLY EAST. I RAMPED UP THE POPS AND
EXPANDED THE COVERAGE AS EARLIER MODEL OUTPUT REALLY DOWNPLAYED
THE AREAL COVERAGE OF THE SHOWERS. NEW MESO MODELS SEEM TO BE
FINALLY CATCHING UP.
WITH CLOUDS IN PLACE AND WEAK SOUTHERLY FLOW...A MILD NIGHT IN
STORE WITH TEMPS ONLY FALLING INTO THE 50S.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM THURSDAY/...
SHORTWAVE SLIDES SE OVER THE WARM FRONT ON WED...BRINGING SOME
BETTER DYNAMICS TO CENTRAL PA. BEST INSTABILITY/LIFT REMAINS OFF
TO OUR WEST THOUGH...AND PRIMARY THREAT OF SVR WEATHER WILL
REMAIN CONFINED TO THOSE REGIONS...BUT SOME STRONGER TSTORMS MAY
SLIP EASTWARD TOWARD OUR WESTERN BORDER LATER WED AS WARM SECTOR
WORKS NE AND MID LEVEL WINDS APPROACH 50 KTS. OVERALL
THOUGH...EXPECTING A SHOWERY DAY WITH SCT TSTORMS.
COLD FRONT FOLLOWS WED NIGHT/EARLY THU...WITH ANOTHER ROUND OF SCT
SHOWERS. THE UPPER LOW DRIVING THIS WHOLE CONVOLUTED SYSTEM WILL
THEN RESIDE OVER NEW ENGLAND FOR A DAY OR SO. THIS WILL KEEP THE
WX COOLER AND UNSETTLED FOR THE REST OF THE WEEK.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
RIDGE-TOPPING SHORTWAVE TROUGH IS EXPECTED TO AMPLIFY/DIG SEWD FROM
THE UPPER GREAT LAKES REGION ACROSS THE NORTHERN MID-ATLC AND
INTERIOR NORTHEAST STATES D3-4. THE UPPER LOW EXITING NORTHERN NEW
ENGLAND WILL ANCHOR A MEAN TROUGH ALONG/OFFSHORE THE EAST COAST SAT-
SUN BEFORE BEING REPLACED BY A GRADUALLY BUILDING HIGH-LEVEL RIDGE
D6-8.
THE 20/00Z AND 20/12Z MODEL AND ENSEMBLE CYCLES CONTINUE TO HANDLE
THE 500MB HEIGHT PATTEN ACROSS THE CONUS REASONABLY WELL THROUGH THE
UPCOMING WEEKEND. THE BULK OF THE UNCERTAINTY IN THE MID-UPPER
LEVEL FLOW AFTER DAY 6 RESIDES OVER THE WESTERN 1/3 OF NOAM.
SENSIBLE WEATHER HIGHLIGHTS...SCT SHWRS W/ISOLD TSTMS SHOULD
ACCOMPANY SFC COLD FRONT THRU CNTRL/RN PA EARLY THURS. THE FRONTAL
PASSAGE WILL BRIEFLY RETURN THE RECENT COOL/DRY CYC FLOW PATTERN
ALOFT WITH DIURNAL/INSTABILITY SHOWERS ASSOCD WITH INDIVIDUAL
SHORTWAVE IMPULSES ROTATING AROUND THE BACKSIDE OF THE DEPARTING
UPPER LEVEL TROUGH. A MID-LEVEL ANTICYCLONE BUILDING NORTH/EAST FROM
THE LWR MS VLY WILL PRODUCE A MORE TYPICAL EARLY-SUMMER PATTERN WITH
STRONG SIGNALS FOR AN UPWARD TREND IN TEMPERATURE/HUMIDITY FROM
MEMORIAL DAY INTO THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
STRONG THUNDERSTORM OVER SW NY HAS WEAKEN...BUT MORE DROPPING
SE FROM LAKE ERIE. AREA OF COOLING TOPS...AND MODELS SHOW
THIS AREA DROPPING SE ACROSS S PA.
THUS ADDED THUNDER TO THE 06Z PACKAGE.
BY MID TO LATE MORNING...THIS ACTIVITY SHOULD BE SOUTH
OF OUR AREA...THUS WENT WITH VFR CONDITIONS.
STILL STRONG DIRECTIONAL SHEAR AND WARM ADVECTION...THUS
WILL HAVE TO ADJUST THE TAFS FOR ANY ADDITIONAL STORMS
LATER TODAY. FOR NOW...LEFT THINGS VFR AFTER 00Z THU.
SOME SHOWERS COULD PERSIST INTO THE WEEKEND...AS ADDITIONAL
ENERGY ROTATES AROUND A DEEP UPPER LEVEL LOW.
BEST DAY FOR DRY WEATHER AND VFR CONDITIONS WILL BE SUNDAY.
.OUTLOOK...
THU...EARLY AM FOG/LOW CIGS POSS...MAINLY W MTNS.
FRI-SAT...MAINLY VFR. SCT SHOWERS POSS MAINLY N AND W WITH LOCAL
RESTRICTIONS.
SUN...NO RESTRICTIONS EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...DANGELO/LA CORTE
SHORT TERM...RXR
LONG TERM...STEINBUGL
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
131 AM EDT WED MAY 21 2014
.SYNOPSIS...
A WARM FRONT WILL SLIDE FROM THE OHIO VALLEY INTO CENTRAL
PENNSYLVANIA TONIGHT AND WEDNESDAY. A COLD FRONT WILL THEN MOVE
THROUGH ON THURSDAY...BRINGING COOLER AIR BACK TO THE REGION. THE
EXTENDED FORECAST INDICATES A GRADUAL WARMING TREND BEGINNING THIS
WEEKEND DESPITE SOME SHOWERS LINGERING IN THE POST- FRONTAL
NORTHWEST FLOW.
&&
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
130 AM UPDATE...
MIGHT AS WELL JUST BLOCK COPY PASTE FROM THE EARLIER DISC.
HOWEVER...THE STORMS MOVING INTO NWRN COS ARE MUCH STRONGER THAN
EARLIER - DESPITE STILL BEING ELEVATED/DETACHED FROM THE SURFACE.
THESE ALSO SEEM TO HAVE BETTER UPPER SUPPORT AND SHOULD LAST
LONGER AND DROP MORE RAIN. THEREFORE...HAVE FURTHER BUMPED POPS
UP AND EXTENDED THEM INTO THE SERN COS LATER TONIGHT. LATEST RUC
AND HRRR PROGS SUPPORT THIS MOVE. DEWPOINTS STILL IN THE 40S OVER
THE LAURELS AND FAR NERN COS WHERE NO RAIN HAS YET FALLEN.
PREV...
THE BACK EDGE OF THE CONVECTION SEEMS TO BE ON THE LAKE ERIE
SHORE-LINE NOW...MAKING A BEE-LINE FOR NW PA WITH STILL AN
OCCASIONAL LIGHTNING STRIKE STILL BEING DISPLAYED.
HOWEVER THE 23Z HRRR KEEPS THIS ZONE ACTIVE INTO THE OVERNIGHT AS
THE WARM FRONT PROGRESSES SLOWLY EAST. I RAMPED UP THE POPS AND
EXPANDED THE COVERAGE AS EARLIER MODEL OUTPUT REALLY DOWNPLAYED
THE AREAL COVERAGE OF THE SHOWERS. NEW MESO MODELS SEEM TO BE
FINALLY CATCHING UP.
WITH CLOUDS IN PLACE AND WEAK SOUTHERLY FLOW...A MILD NIGHT IN
STORE WITH TEMPS ONLY FALLING INTO THE 50S.
&&
.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM THURSDAY/...
SHORTWAVE SLIDES SE OVER THE WARM FRONT ON WED...BRINGING SOME
BETTER DYNAMICS TO CENTRAL PA. BEST INSTABILITY/LIFT REMAINS OFF
TO OUR WEST THOUGH...AND PRIMARY THREAT OF SVR WEATHER WILL
REMAIN CONFINED TO THOSE REGIONS...BUT SOME STRONGER TSTORMS MAY
SLIP EASTWARD TOWARD OUR WESTERN BORDER LATER WED AS WARM SECTOR
WORKS NE AND MID LEVEL WINDS APPROACH 50 KTS. OVERALL
THOUGH...EXPECTING A SHOWERY DAY WITH SCT TSTORMS.
COLD FRONT FOLLOWS WED NIGHT/EARLY THU...WITH ANOTHER ROUND OF SCT
SHOWERS. THE UPPER LOW DRIVING THIS WHOLE CONVOLUTED SYSTEM WILL
THEN RESIDE OVER NEW ENGLAND FOR A DAY OR SO. THIS WILL KEEP THE
WX COOLER AND UNSETTLED FOR THE REST OF THE WEEK.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
RIDGE-TOPPING SHORTWAVE TROUGH IS EXPECTED TO AMPLIFY/DIG SEWD FROM
THE UPPER GREAT LAKES REGION ACROSS THE NORTHERN MID-ATLC AND
INTERIOR NORTHEAST STATES D3-4. THE UPPER LOW EXITING NORTHERN NEW
ENGLAND WILL ANCHOR A MEAN TROUGH ALONG/OFFSHORE THE EAST COAST SAT-
SUN BEFORE BEING REPLACED BY A GRADUALLY BUILDING HIGH-LEVEL RIDGE
D6-8.
THE 20/00Z AND 20/12Z MODEL AND ENSEMBLE CYCLES CONTINUE TO HANDLE
THE 500MB HEIGHT PATTEN ACROSS THE CONUS REASONABLY WELL THROUGH THE
UPCOMING WEEKEND. THE BULK OF THE UNCERTAINTY IN THE MID-UPPER
LEVEL FLOW AFTER DAY 6 RESIDES OVER THE WESTERN 1/3 OF NOAM.
SENSIBLE WEATHER HIGHLIGHTS...SCT SHWRS W/ISOLD TSTMS SHOULD
ACCOMPANY SFC COLD FRONT THRU CNTRL/RN PA EARLY THURS. THE FRONTAL
PASSAGE WILL BRIEFLY RETURN THE RECENT COOL/DRY CYC FLOW PATTERN
ALOFT WITH DIURNAL/INSTABILITY SHOWERS ASSOCD WITH INDIVIDUAL
SHORTWAVE IMPULSES ROTATING AROUND THE BACKSIDE OF THE DEPARTING
UPPER LEVEL TROUGH. A MID-LEVEL ANTICYCLONE BUILDING NORTH/EAST FROM
THE LWR MS VLY WILL PRODUCE A MORE TYPICAL EARLY-SUMMER PATTERN WITH
STRONG SIGNALS FOR AN UPWARD TREND IN TEMPERATURE/HUMIDITY FROM
MEMORIAL DAY INTO THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
SHOWERS CONTINUE TO TO INCREASE AS THEY ARE STREAMING ACROSS THE
NORTH EASTERN HALF OF PENNSYLVANIA THIS EVENING. THIS HAS ALLOWED
FOR BRIEF IFR CONDITIONS AT BFD...AND POSSIBLE MVFR AT IPT. THESE
SHOWERS ARE LIGHT IN GENERAL...BUT EMBEDDED HEAVY SHOWERS COULD
ALLOW FOR BRIEF MVFR TO IFR CIGS AND VSBYS AS THE SYSTEM MOVES IN
OVERNIGHT. THE SHOWERS HAVE ALSO ALLOWED FOR THE SFC TO BE MIXED
AND CAUSED GUSTY WINDS AT UNV. THESE WINDS WILL SUBSIDE BETWEEN 06
TO 08Z AS THE SFC DECOUPLES.
SHOWER ACTIVITY WILL PICK UP AS THE NIGHT PROGRESSES AND THROUGH TOMORROW
AS A WARM FRONT MOVES ACROSS THE REGION. THIS WILL BE QUICKLY FOLLOWED
BY A COLD FRONT ON THURSDAY. SCT THUNDERSTORMS WILL ALSO IMPACT
CENTRAL PA...MAINLY DURING THE DAY TOMORROW...WITH A FEW STRONG
STORMS POSS ACROSS THE NORTH AND WEST LATER WED INTO WED EVE.
LOWERING CIGS WILL SLIDE IN FROM THE NORTHWEST LATE TONIGHT AND
MAY BRING RESTRICTIONS INTO THE CENTRAL MTNS FOR MUCH OF WED. THE
SE SHOULD REMAIN MAINLY VFR...EXCEPT FOR LOCALIZED TSTORM IMPACTS.
.OUTLOOK...
WED...AM FOG/LOW CIGS LIKELY NORTHERN/CENTRAL MTNS. SCT MAINLY PM
TSRA IMPACTS POSS.
THU...EARLY AM FOG/LOW CIGS POSS...MAINLY W MTNS.
FRI-SAT...MAINLY VFR. SCT SHOWERS POSS MAINLY N AND W WITH LOCAL
RESTRICTIONS.
SUN...NO RESTRICTIONS EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...DANGELO/LA CORTE
SHORT TERM...RXR
LONG TERM...STEINBUGL
AVIATION...CERU/RXR
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1211 AM CDT WED MAY 21 2014
.DISCUSSION...
SEE AVIATION FOR 6Z TAF ISSUANCE.
&&
.AVIATION...
MVFR CONDITIONS HAVE FORMED ALONG THE COAST THIS EVENING AND HAVE
STARTED TO TRY AND MOVE INLAND. MORE WIDESPREAD MVFR CONDITIONS
REMAIN OFF TO OUR WEST. HRRR SHOWING LOW CLOUDS FILLING IN FROM
THE WEST BUT REMAINING PATCHY. GFS FORECAST SOUNDINGS ALSO HINT AT
THIS. AMDAR SOUNDINGS AGAIN LOOK SIMILAR TO LAST NIGHT BUT RH
LOOKS A TAD LOWER TONIGHT IN THE LOW LEVELS. THIS MEANS THAT TAF
SITES WILL LIKELY BOUNCE IN AND OUT OF MVFR TONIGHT WITH TAF SITES
FURTHER TO THE WEST HAVING A GREATER CHANCE OF STAYING MVFR
OVERNIGHT. 23
&&
.PREV DISCUSSION... /ISSUED 931 PM CDT TUE MAY 20 2014/
UPDATE...
00Z UA ANALYSIS INDICATES STRONG 850 RIDGING OVER THE FL PANHANDLE
EXTENDING INTO TEXAS WITH SOUTHERLY FLOW TOPPED BY 500MB RIDGE
OVER CENTRAL AND NORTHEAST TEXAS. SUBSIDENCE IS THE WEATHER WORD
OF THE DAY. SO OVERNIGHT EXPECT THAT LL MOISTURE WILL CONDENSE OUT
AND LIKELY TO FORM A BKN/OVER SC DECK OVER MAINLY THE WESTERN AND
NORTHWESTERN AREAS BUT THE METROPLEX SHOULD SEE SOME MOSTLY CLOUDY
TO CLOUDY SKIES AFTER MIDNIGHT AS WELL. UPDATED THE FORECAST TO
DECREASE THE CLOUD COVER THE CLEAR AT 9 FOR ALL THE INLAND
COUNTIES. THEN INCREASE THE CLOUD COVER OVERNIGHT WITH MOSTLY
CLOUDY CONDITIONS DEVELOPING. IN TURN DID RAISE TEMPS A FEW
DEGREES MAINLY WEST OF I-45.
45
PREV DISCUSSION... /ISSUED 246 PM CDT TUE MAY 20 2014/
DISCUSSION...
LATE SPRING DOLDRUMS CONTINUE AS VERY LITTLE DAY TO DAY CHANGES
ARE EXPECTED. UPPER LEVEL RIDGING WILL REMAIN OVER TEXAS THROUGH
FRIDAY WITH A GRADUAL WARMING TREND. RAIN CHANCES WILL REMAIN VERY
LOW WITH ONLY ISOLATED STREAMER SHOWERS POSSIBLE DURING THE EARLY
MORNING HOURS. THE UPPER RIDGE MOVES EAST OVER THE WEEKEND AND
HEIGHTS WILL BEGIN TO FALL. MODELS ARE TRENDING COOLER OVER THE
WEEKEND WHICH SEEMS REASONABLE CONSIDERING THE LOWER HEIGHTS. AN
UPPER LEVEL TROUGH WILL APPROACH THE STATE EARLY NEXT WEEK. IT
STILL LOOKS LIKE THE UPPER TROUGH WILL PASS TOO FAR NORTH TO HAVE
MUCH OF AN IMPACT LOCALLY. STILL...LOWER HEIGHTS AND INCREASING
LIFT AHEAD OF THE TROUGH COULD TRIGGER A FEW SHRA/TSRA SO WILL
MAINTAIN SLIGHT RAIN CHANCES MON/TUES. 43
MARINE...
PERSISTENT ONSHORE FLOW THROUGH THE REMAINDER OF THE WEEK WILL BE
GENERALLY LIGHT...OCCASIONALLY NEAR CAUTION MAGNITUDES DURING THE
OVERNIGHT INTO EARLY MORNING HOURS. SLIGHTLY CHOPPY BAY CONDITIONS
AND AVERAGE 2 FOOT NEARSHORE WAVE HEIGHTS...3 TO 4 FOOT HEIGHTS
FURTHER OFFSHORE. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 87 70 90 69 87 / 10 0 0 10 10
HOUSTON (IAH) 86 70 88 69 86 / 10 0 0 10 10
GALVESTON (GLS) 82 73 81 73 83 / 10 0 0 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...45
AVIATION/MARINE...23
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1149 PM CDT TUE MAY 20 2014
.UPDATE...
ISSUED AT 635 PM CDT TUE MAY 20 2014
SURFACE BASED CONVECTION FIRED ABOUT 2 HOURS AGO JUST SOUTH OF THE
FORECAST AREA...THROUGH THE DUBUQUE AREA...ALONG A SURFACE TROUGH
THERE. ANTICIPATING OUTFLOWS FROM THE CONVECTION WILL HELP TO KEEP
MUCH OF THE CONVECTION SOUTH OF THE FORECAST AREA THROUGH THE
EVENING...THUS HAVE CONTINUED TO TREND PRECIPITATION CHANCES DOWN
AND FARTHER SOUTH. APPEARS ONLY FAR SOUTHERN PORTIONS OF
GRANT...CLAYTON AND FAYETTE COUNTIES COULD BE CLIPPED BY
SHOWERS/STORMS COMING OUT OF CENTRAL IOWA.
MEANWHILE...A FRONTOGENETIC BAND OF HIGH BASED SHOWERS...EVEN A
FEW THUNDERSTORMS...HAS BEEN OCCURRING ACROSS NORTHWEST IOWA. WILL
HAVE TO MONITOR THIS FEATURE THROUGH THE EVENING TO SEE IF IT CAN
IMPACT SOUTHEAST MN. WOULD ANTICIPATE VERY LITTLE PRECIPITATION
DUE TO DRIER LOW LEVEL AIR THAT HAS BEEN INVADING THE AREA THIS
AFTERNOON. IN FACT...EVEN UNDER THE FRONTOGENETIC BAND...REPORTS
OF RAIN ARE HARD TO COME BY. 20.21Z RAP/HRRR GUIDANCE SUGGESTS THE
BAND WILL DIMINISH AS IT COMES INTO SOUTHEAST MN THIS EVENING...SO
GIVEN ALL OF THIS HAVE KEPT THE FORECAST DRY.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 258 PM CDT TUE MAY 20 2014
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL RIDGE
FLATTENING OUT OVER THE UPPER MIDWEST AND GREAT LAKES REGION. A VERY
WEAK SHORTWAVE TROUGH ON THE NORTHERN PERIPHERY OF THE UPPER LEVEL
RIDGE IS PRODUCING VERY LIGHT RAIN OR SPRINKLES ACROSS SOUTHERN
MINNESOTA PER LATEST MOSAIC RADAR. LATEST 19Z SURFACE ANALYSIS
INDICATING A WEAK COLD FRONT EXTENDING FROM CENTRAL WISCONSIN INTO
CENTRAL IOWA.
MAIN FORECAST CONCERNS ARE SHOWERS AND THUNDERSTORMS DEVELOPMENT
ALONG SURFACE FRONT LATE THIS AFTERNOON AND THIS EVENING. THE LATEST
20.12Z GFS/NAM AND 20.15Z RAP ARE INDICATING ALONG SURFACE FRONT CAP
WILL BREAK IN THE 22Z TUESDAY - 02Z WEDNESDAY TIME FRAME AND FOR
SHOWERS AND THUNDERSTORMS TO DEVELOP ALONG SURFACE FRONT PER BUFKIT
SOUNDINGS OVER EXTREME SOUTHERN FORECAST AREA. THE LATEST 20.16Z
HRRR DEVELOPS SHOWERS AND THUNDERSTORMS AROUND 23Z ACROSS SOUTHERN
FAYETTE...CLAYTON AND GRANT COUNTIES. THE 20.15Z RAP AND 20.12Z NAM
INDICATES ROUGHLY 1000-2000 J/KG OF SURFACE BASE CAPE AND 0-6KM
SHEAR APPROACHING 40 KNOTS LATE THIS AFTERNOON ALONG AND AHEAD
SURFACE FRONT ACROSS THE EXTREME SOUTHERN FORECAST AREA. THE 20.15Z
RAP/20.12Z NAM SHOW 0-1KM SHEAR LESS THAN 5 KNOTS OVER THIS AREA.
THE EXTREME SOUTHERN FORECAST AREA POSSIBLY COULD SEE SEVERE
THUNDERSTORMS WITH THE MAIN THREATS AT THIS TIME LOOK TO BE LARGE
HAIL AND WIND OVER THE EXTREME SOUTHERN FORECAST AREA.
SURFACE FRONT MOVES SOUTH OF FORECAST AREA WEDNESDAY AND DRIER AIR
AND SLIGHTLY COOLER AIR FILTERS INTO THE FORECAST AREA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 258 PM CDT TUE MAY 20 2014
SURFACE RIDGE BUILDS INTO THE FORECAST AREA THURSDAY INTO FRIDAY.
WITH SUBSIDENCE UNDERNEATH RIDGE AND FORECAST AREA UNDER NORTHERLY
FLOW. THIS SHOULD ALLOW FOR DRY WEATHER CONDITIONS AND SEASONABLE
TEMPERATURES ACROSS THE FORECAST AREA.
FOCUS THEN TURNS TO FRIDAY NIGHT INTO TUESDAY...WHERE THE MAIN
CONCERNS ARE PRECIPITATION CHANCES SATURDAY NIGHT INTO TUESDAY. THE
20.12Z GFS/ECMWF/GEM ARE IN GOOD AGREEMENT IN BUILDING UPPER
LEVEL RIDGE INTO THE CENTRAL UNITED STATES THIS WEEKEND...THEN
BREAKING DOWN UPPER LEVEL RIDGE AND DEVELOP SOUTHWEST FLOW OVER
THE CENTRAL UNITED STATES BY 00Z MONDAY. THE BIGGEST DIFFERENCES
BETWEEN THE MODELS IS TIMING AND STRENGTH OF SHORTWAVE TROUGHS
EJECTING OUT INTO THE NORTHERN PLAINS AND UPPER GREAT LAKES REGION
THROUGH THE PERIOD. THE FORECAST AREA SHOULD REMAIN DRY THROUGH
SATURDAY NIGHT AS UPPER LEVEL RIDGE DOMINATES THE GREAT LAKES
REGION. THEN...FIRST IMPULSE BEGINS TO BREAK RIDGE DOWN SUNDAY AND
PROVIDE THE POSSIBILITY OF SHOWERS AND THUNDERSTORMS INTO THE
WESTERN HALF OF THE FORECAST AREA. WITH UPPER LEVEL RIDGE BREAKING
DOWN OVER THE UPPER MIDWEST AND GREAT LAKES REGION MEMORIAL DAY
AND TUESDAY...A SERIES OF SHORTWAVE TROUGHS EMBEDDED IN THE
SOUTHWESTERLY FLOW ALOFT WILL MOVE OVER THE AREA. THE 20.12Z
GFS/ECMWF/GEM INDICATE STRENGTH ISSUES WITH EACH SHORTWAVE
TROUGH...HOWEVER THE SHORTWAVE TROUGH SHOW BETTER MOISTURE
TRANSPORT/CONVERGENCE OVER THE REGION BY 00Z TUESDAY. WILL
CONTINUE WITH CHANCES OF SHOWERS AND THUNDERSTORMS ACROSS FORECAST
AREA...ESPECIALLY LATE MEMORIAL DAY INTO TUESDAY. TEMPERATURES
FRIDAY NIGHT INTO TUESDAY WILL BE SLIGHTLY ABOVE NORMAL...AS THE
GFS/ECMWF/GEM INDICATE 850MB TEMPERATURES IN THE PLUS 14 TO PLUS
16 DEGREES CELSIUS RANGE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1149 PM CDT TUE MAY 20 2014
SKIES ARE CLEARING OUT AND WITH WINDS LIGHT...CONCERN EXISTS
ABOUT FOG. THERE HAS ALREADY BEEN PLENTY OF FOG REPORTS ACROSS
PORTIONS OF CENTRAL MINNESOTA. HOWEVER...THEY HAVE HAD A LONGER
PERIOD OF CLEARING AND TEMPERATURE/DEWPOINT SPREADS ARE MUCH
GREATER AT THE TAF SITES. IN ADDITION...BREEZIER NORTHWEST WINDS
OVER WESTERN MINNESOTA ARE WORKING THEIR WAY SOUTHEAST BEHIND A
COLD FRONT. SO IT SEEMS LIKE THE WINDOW OF OPPORTUNITY FOR FOG
WILL BE VERY SMALL AT EITHER TAF SITE...MAINLY 07-09Z AT RST AND
09-12Z AT LSE. FOR NOW HAVE NOT MENTIONED FOG IN THE TAFS BUT WILL
NEED MONITORING FOR THE EARLY MORNING HOURS.
OTHERWISE...THE DRY AIR ASSOCIATED WITH THE NORTHWEST WINDS WILL
HELP KEEP CONDITIONS VFR. NOTE THAT THERE SHOULD BE SOME CUMULUS
AROUND DURING THE DAYTIME...AND EVEN THE EVENING HOURS AT
LSE...BUT STILL ANTICIPATING THE SKIES TO STAY VFR. PLAN ON THOSE
AFOREMENTIONED NORTHWEST WINDS TO PICK UP TO 10-15 KT BY LATE
MORNING...WITH GUSTS TO 20 KT POSSIBLE. THE WINDS WILL SUBSIDE
SOME IN THE EVENING WITH LOSS OF DAYTIME HEATING.
&&
.HYDROLOGY...
ISSUED AT 258 PM CDT TUE MAY 20 2014
WATER LEVELS CONTINUE TO SLOWLY FALL ALONG THE MISSISSIPPI RIVER AND
FEW LOCATIONS REMAIN ABOVE FLOOD STAGE. THE WATER LEVELS WILL REMAIN
HIGH ALONG THE MISSISSIPPI RIVER THROUGH NEXT WEEK.
IN ADDITION...DUE TO RECENT RAINFALL AMOUNTS OF ONE TO TWO AND A
HALF INCHES IN THE HEADWATERS OF THE BLACK RIVER. THE BLACK RIVER
HAS RISEN ABOVE FLOOD OR IS EXPECTED TO RISE ABOVE FLOOD STAGE AT A
COUPLE LOCATIONS OVER THE NEXT COUPLE OF DAYS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...AJ
HYDROLOGY...DTJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1016 PM MDT TUE MAY 20 2014
.UPDATE...
ISSUED AT 944 PM MDT TUE MAY 20 2014
GRIDDED FORECASTS UPDATED FOR THE OVERNIGHT TO ACCOUNT FOR SPATIAL
COVERAGE OF ISOLATED SHOWERS AND THUNDERSTORMS EAST OF A DOUGLAS
TO PINE BLUFFS LINE. TEMPERATURE AND DEWPOINT SPREADS CONTINUE
TO NARROW WITH FOG ALREADY REPORTED AT CHADRON...AND WITH THE
NAM INDICATING BOUNDARY LAYER WINDS FROM THE EAST AND SOUTHEAST
LATE TONIGHT...AND BOUNDARY LAYER RELATIVE HUMIDITIES FROM 70 TO
100 PERCENT...HAVE ADDED MENTION OF AREAS OF FOG...WITH LOWER
VISIBILITIES FROM DOUGLAS TO LUSK WHERE MORE RAIN FELL...AND
WHERE BOUNDARY LAYER HUMIDITIES ARE PROGGED NEAR 100 PERCENT NEAR
DAYBREAK. 64/RUBIN
UPDATE ISSUED AT 716 PM MDT TUE MAY 20 2014
BEGAN PEELING OUR SOUTHEAST WYOMING COUNTIES OUT OF THE SEVERE
THUNDERSTORM WATCH. CONVECTION MAINLY CONFINED TO THE PANHANDLE
WITH SOME LIGHT CONVECTION OVER NORTHERN PLATTE AND GOSHEN
COUNTIES. THIS CONVECTION IN SOUTHEAST WYOMING APPEARS TO BE
WEAKENING...THEREFORE THE CANCELLATION OF THE WATCH. UPDATES HAVE
BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 300 PM MDT TUE MAY 20 2014
FORECAST CHALLENGES CONTINUE TO BE SEVERE THUNDERSTORM CHANCES
TODAY AND WEDNESDAY.
CURRENTLY...FAIRLY QUIET RIGHT NOW EARLY THIS AFTERNOON ACROSS THE
CWFA. STARTING TO GET SOME LIGHTNING STRIKES FROM CONVECTION
DEVELOPING OVER THE LARAMIE RANGE. WOULD EXPECT THIS TO CONTINUE
TO INCREASE IN COVERAGE AND INTENSITY AS THE AFTERNOON CONTINUES.
EASTERLY TO SOUTHEASTERLY SURFACE WINDS ACROSS EASTERN PORTIONS OF
THE CWFA WITH PRETTY GOOD DEWPOINTS. GETTING UPPER 40S OUT BY
CHADRON...47 HERE AT CHEYENNE AND 43 UP BY DOUGLAS. TEMPERATURES
IN THE MID 60S JUST ABOUT EVERYWHERE EAST OF THE LARAMIE RANGE.
LATEST SPC MESOANALYSIS SHOWING SURFACE BASED CAPES AROUND 1000
J/KG ALONG THE LARAMIE RANGE WITH NO CONVECTIVE INHIBITION
ANALYZED AT THIS TIME. LIFTED INDICES NEAR ZERO JUST ABOUT
EVERYWHERE WITH -3C IN THE GENERAL LOCATION WHERE CONVECTION IS
INITIATING. LATEST WATER VAPOR IMAGERY SHOWING CLOSED LOW MOVING
INTO CENTRAL NEVADA THIS AFTERNOON.
FOR LATER THIS AFTERNOON...LOOKING AT LIFTED INDICES TO CONTINUE
FALLING TO -3 TO -4C ACROSS MUCH OF THE AREA EAST OF THE LARAMIE
RANGE BY 00Z. LATEST HRRR CONVECTIVE FORECAST KEYED INTO A
SUPERCELL DEVELOPING NEAR WHEATLAND THIS AFTERNOON...THEN TRACKING
EAST ACROSS TORRINGTON BY 23Z AND THEN INTO SOUTHERN SIOUX COUNTY
BY THE 00-01Z TIME FRAME. CONVECTION FAIRLY WIDESPREAD ACROSS THE
NORTHERN PANHANDLE AFTER 00Z. HIGH 0-6KM BULK SHEAR FORECASTS OF
60 TO 65KTS SHOULD SUPPORT VERY LARGE HAIL DEVELOPMENT WITH STORMS
THAT GET GOING THIS AFTERNOON. ONE LAST ITEM WITH THE STORMS
TODAY. FORECAST STORM MOTIONS ARE LOW...GENERALLY 10KTS OR LESS.
SO WE NEED TO WATCH FOR HEAVY RAIN/POSSIBLE LOCALIZED FLASH
FLOODING.
PRETTY MUCH A REPEAT FOR WEDNESDAY AFTERNOON. SEVERE THUNDERSTORM
POTENTIAL WILL CONTINUE FOR LOCATIONS EAST OF THE LARAMIE RANGE.
MAYBE MORE DOWN IN THE SOUTHERN PART OF THE CWFA DOWN HERE NEAR
CHEYENNE.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 300 PM MDT TUE MAY 20 2014
MEDIUM RANGE GUIDANCE IS IN EXCELLENT AGREEMENT WITH A POTENT CUTOFF
LOW OVER THE 4 CORNERS EARLY IN THE FCST PERIOD. NOT MUCH CHANGE IN
SENSIBLE WEATHER ACROSS THE REGION WITH THIS PATTERN IN PLACE...WITH
CONTINUED DAILY CHANCES FOR SHOWERS AND STORMS THROUGH THE WEEKEND
AND INTO EARLY NEXT WEEK. THIS FEATURE LIFTS NORTHEAST TOWARD THE
CENTRAL HIGH PLAINS ON SUN AND MON WITH THE ECMWF STILL ADVERTISING
DEFORMATION PRECIP BANDING ON THE BACK SIDE. POTENTIAL EXISTS FOR A
FAIRLY WIDESPREAD MODERATE RAIN EVENT DURING THIS TIME...HOWEVER THE
GFS IS NOT AS BULLISH WITH QPF AMOUNTS. WILL NEED TO WATCH CLOSELY
AS THIS WILL CAUSE HYDRO ISSUES IF THIS PCPN FALLS OVER THE SNOW
PACKED MOUNTAINS. H7 TEMPS WILL BE AROUND 8 TO 10 DEG C THROUGH THE
MAJORITY OF THE FCST PERIOD...GIVING WAY TO HIGHS BETWEEN 65 AND 75
DEGREES FOR MUCH OF THE LOWER ELEVATIONS. WESTERLY DOWNSLOPE RETURNS
ON MON...GIVING WAY TO WARMER AND DRIER CONDITIONS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY AFTERNOON)
ISSUED AT 553 PM MDT TUE MAY 20 2014
CONVECTION TO CONTINUE THROUGH SUNSET THIS EVENING. WINDS
FAVORABLE OVERNIGHT FOR SOME UPSLOPING STRATUS TO DEVELOP HERE AT
KCYS AND POSSIBLY KLAR. WENT MVFR OF CEILINGS...BUT LATER SHIFTS
MAY NEED TO LOWER FURTHER.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MDT TUE MAY 20 2014
CONCERNS TO REMAIN LOW FOR THE REST OF THE WEEK WITH CONDITIONS
AND FUELS EXPECTED TO REMAIN NON-CRITICAL. SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS WILL MOVE ACROSS MAINLY EASTERN DISTRICTS
MOST DAYS WITH VERY GOOD CHANCES FOR WETTING RAINS. A MORE
WIDESPREAD RAIN EVENT SATURDAY AFTERNOON THROUGH MONDAY MORNING
SHOULD DEVELOP ACROSS SOUTHEAST WYOMING AND NEBRASKA
PANHANDLE...SO FIRE WEATHER CONCERNS ARE MINIMAL.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RUBIN
SHORT TERM...CLAYCOMB
LONG TERM...HAMMER
AVIATION...CLAYCOMB
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS PUEBLO CO
524 AM MDT WED MAY 21 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM MDT WED MAY 21 2014
...SEVERE THUNDERSTORMS POSSIBLE NORTHERN PORTIONS OF THE SOUTHEAST
PLAINS...CRITICAL FIRE WEATHER CONDITIONS EXPECTED ACROSS THE SAN
LUIS VALLEY...
UPPER LOW WILL STALL OUT OVER NEVADA TODAY BEFORE DROPPING SOUTHWARD
INTO SOUTHERN CA LATER TONIGHT. SOUTHERLY FLOW AHEAD OF THE SYSTEM
TODAY WILL START TO SHIFT SOME MID/HIGH LEVEL MOISTURE INTO THE
WESTERN MTS TODAY...BUT BY IN LARGE...LOWER LEVELS WILL REMAIN QUITE
DRY. WITH SOUTH TO SOUTHWEST WINDS INCREASING AGAIN ACROSS THE
SOUTHWEST MTS AND SAN LUIS VALLEY...EXPECT A RETURN OF CRITICAL FIRE
WEATHER CONDITIONS FOR THE SAN LUIS VALLEY WHERE FUELS ARE
CRITICALLY DRY. RAPID RATES OF FIRE SPREAD WILL BE POSSIBLE WITH
ANY FIRE STARTS AND CURRENT RED FLAG WARNING STILL LOOKS GOOD.
THERE COULD BE SOME ISOLATED HIGH BASED THUNDERSTORMS ALONG THE
CONTDVD TODAY...BUT THEY WILL BE FEW AND FAR BETWEEN...AND WITH
INVERTED V SOUNDINGS...MORE LIKELY TO PRODUCE GUSTY WINDS THAN MUCH
IN THE WAY OF RAINFALL.
DIFFERENT STORY WILL EXIST TODAY FOR THE SOUTHEAST PLAINS. LOW LEVEL
MOISTURE HAS SPREAD BACK IN WITH CURRENT DEW POINTS IN THE 50S FOR
THE LOWER ARKANSAS RIVER...WITH UPPER 40S FOR CANON CITY...AND EVEN
WOODLAND PARK SEEING LOWER 40 DEW POINTS. SOUTHERN I-25 CORRIDOR IS
STILL QUITE DRY WITH KTAD DEW POINT AT 13 AS OF 09Z. BOUNDARY WILL
CONTINUE TO PUSH SLOWLY SOUTHWARD THIS MORNING WITH STRATUS
EXPANDING ACROSS SOUTHEAST CO IN LIGHT UPSLOPE REGIME ALONG THE
LOWER EASTERN SLOPES OF TELLER/EL PASO COUNTY...THE LOWER WET
MOUNTAINS...AND THE NORTHERN SLOPES OF THE RATON RIDGE. THIS SHOULD
BURN OFF DURING THE LATE MORNING WITH DEW POINTS STAYING IN THE
UPPER 40S/LOWER 50S THROUGH EARLY AFTERNOON ACROSS THE MAJORITY OF
THE SOUTHEAST PLAINS. VORT MAX ACROSS NEW MEXICO WILL MOVE IN THIS
AFTERNOON...AND DRIER AIR WILL BEGIN TO MIX NORTHWARD OFF THE RATON
RIDGE. MAIN FACTOR DETERMINING EXTENT OF SEVERE WEATHER POTENTIAL
WILL BE HOW QUICKLY THESE DEW POINTS MIX OUT. HRRR AND RAP13 DROPS
DEW POINTS INTO THE UPPER 30S FOR THE I-25 CORRIDOR WITH 40S FARTHER
EAST BY 21Z. NAM12 AND LOCAL 4KM WRF KEEPS DEW POINTS IN THE LOWER
50S AT 21Z NORTHEAST OF A LINE FROM KCOS...TO KLHX...TO KSPD. SO
CAPES COULD BE AS LOW AS 500 J/KG ALONG THE I-25 CORRIDOR TO AROUND
1500 J/KG ACROSS KIOWA...BENT...PROWERS COUNTIES IF THE RAP IS
CORRECT. OR THEY COULD BE AROUND 1500+ J/KG IF THE NAM12 IS
CORRECT. EITHER WAY...0-6KM SHEARS WILL BE RUNNING AROUND 40-50
KTS...OR EVEN A LITTLE BETTER IF LOW LEVEL WINDS STAY OUT OF THE
EAST...WHICH WOULD SUPPORT DEVELOPMENT OF SUPERCELL THUNDERSTORMS.
BEST CHANCES FOR SEVERE LOOK TO BE ACROSS NORTHERN SECTIONS OF THE
SOUTHEAST PLAINS...WHERE HIGHER DEW POINTS ARE MORE LIKELY TO STAY
IN THE LONGEST. INITIATION MAY OCCUR ALONG THE NORTHERN SLOPES OF
THE RATON MESA AROUND 1 PM...WITH THUNDERSTORMS SPREADING/DEVELOPING
NORTHWARD ACROSS THE SOUTHEAST PLAINS THROUGH THE AFTERNOON.
MAJORITY OF THE ACTIVITY MOVES OUT OF THE AREA BY 00Z AS VORT MAX
LIFTS NORTHWARD. LARGE HAIL AND DAMAGING WINDS WILL BE THE MOST
LIKELY SEVERE THREAT...ESPECIALLY TO THE NORTH OF THE ARKANSAS
RIVER. IF DEW POINTS CAN STAY HIGH ENOUGH...THUS...LCLS LOW
ENOUGH...THERE COULD BE ENOUGH LOW LEVEL HELICITY FOR AN ISOLATED
TORNADO. THIS WOULD BE MORE LIKELY TO OCCUR ALONG THE PALMER DIVIDE
AND KIOWA COUNTY...BUT THREAT FOR THIS APPEARS ON THE LOWER SIDE OF
THE SPECTRUM AT THIS POINT. POTENTIAL FOR DAMAGING WIND GUSTS WILL
EXTEND FARTHER SOUTHWARD ACROSS THE SOUTHEAST PLAINS THAN HAIL
THREAT DUE TO HIGHER AVAILABLE DOWNDRAFT CAPE. WILL LIKELY PLAY THE
SEVERE THREAT AREA NORTHEAST OF A LINE FROM COLORADO SPRINGS...TO LA
JUNTA...TO TWO BUTTES.
FINAL CONCERN IS FOR POTENTIAL FOR HEAVY RAINFALL ON THE BURN SCARS
THIS AFTERNOON...PARTICULARLY ACROSS WALDO AND BLACK FOREST. WINDOW
FOR GREATEST THREAT WILL BE FROM 2 PM TO 6 PM...PROBABLY CENTERED
MORE IN THE 3 TO 5 PM RANGE FOR WALDO. AGAIN...STRENGTH OF
UPDRAFTS/POTENTIAL RAINFALL EFFICIENCIES WILL DEPEND ON HOW MUCH LOW
LEVEL MOISTURE STAYS IN. HUNCH IS THAT HIGHER TERRAIN WILL MIX OUT
AT LEAST SOME OF THE LOW LEVEL MOISTURE AND LCLS WILL BE UP AROUND
11-12KFT MSL...WHICH WILL ALLOW FOR SOME EVAPORATION BELOW CLOUD
BASE. ALTHOUGH THREAT FOR FLASH FLOOD PRODUCING RAINFALL IS THERE
TODAY...THINK THE THREAT IS BELOW A 40 PERCENT PROBABILITY. MORE
LIKELY SCENARIO IS FOR SOME RAINFALL AMOUNTS GENERALLY IN THE
.10 TO .40 RANGE...WHICH COULD MEAN SOME FLOOD ADVISORY RAINFALL
CAUSING MINOR RUN OFF FOR THE WALDO BURN SCAR. MAJORITY OF THE HIGH
RES MODELS SUGGEST THE LESSER IMPACT SCENARIO...BUT SITUATION WILL
REQUIRE CLOSE MONITORING THROUGH THE AFTERNOON AND EARLY EVENING
HOURS.
THUNDERSTORMS WILL COME TO AN END DURING THE EVENING FOR MOST
AREAS...WITH ANOTHER INTRUSION OF STRATUS TOWARDS MORNING ACROSS
NORTHERN PORTIONS OF THE SOUTHEAST PLAINS. -KT
.AVIATION... MVFR CIGS WILL CONTINUE TO EXPAND ACROSS THE SOUTHEAST
PLAINS THROUGH MORNING...WITH SOME POCKETS OF IFR CIGS ACROSS THE
PIKES PEAK REGION AND ALONG THE LOWER EASTERN SLOPES OF THE
SOUTHEAST MOUNTAINS. COULD EVEN SEE SOME PATCHY FOG. STRATUS
SHOULD ERODE BY 17-18Z FOR MOST AREAS WITH ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING DURING THE EARLY AFTERNOON ACROSS THE
SOUTHEAST MOUNTAINS AND NORTHERN SLOPES OF THE RATON RIDGE. THESE
WILL BE CAPABLE OF PRODUCING VFR TO LOCAL MVFR CIGS/VIS. LARGE HAIL
AND ERRATIC WIND GUSTS TO AROUND 50 KTS WILL BE POSSIBLE NORTH OF A
LINE FROM KCOS THE KLHX TO NORTH OF KSPD. THREAT DIMINISHES AFTER
00Z FOR THE KCOS AND KPUB TAF SITES. KALS WILL REMAIN DRY TODAY
WITH VFR CONDITIONS...THOUGH EXPECT A RETURN OF SOUTHWEST WINDS 15-
30 KTS IN THE AFTERNOON. -KT
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 523 AM MDT WED MAY 21 2014
NOT MANY ADJUSTMENTS NEEDED FOR THE LONGER TERM AS UNSETTLED
PATTERN IS STILL ANTICIPATED WITH LONGER TERM METEOROLOGICAL
ISSUES REMAINING POPS...SEVERE WEATHER THREAT AT TIMES WITH
INITIAL LONGER TERM FOCUS FOR SEVERE WEATHER FROM THURSDAY INTO
THURSDAY NIGHT...LOCALLY HEAVY RAINFALL AND ASSOCIATED BURN SCAR
FLOODING THREAT AND TEMPERATURES.
RECENT LONGER TERM FORECAST MODEL SOUNDINGS AND COMPUTER
SIMULATIONS CONTINUE TO SUGGEST THAT CLOSED UPPER LOW LOCATED
OVER SOUTHERN NEVADA AT 00Z FRIDAY WILL SHIFT INTO THE 4-CORNERS
REGION BY 00Z SUNDAY AND THEN SLOWLY MOVES ACROSS SOUTHERN
COLORADO INTO MONDAY MORNING BEFORE MOVING EAST OF THE FORECAST
DISTRICT BY MONDAY NIGHT/TUESDAY MORNING.
UNSETTLED METEOROLOGICAL CONDITIONS(PRIMARILY IN THE FORM OF
RAIN...HEAVY AT TIMES AS WELL AS STRONG TO SEVERE STORMS AT
TIMES) ARE ANTICIPATED FROM THURSDAY INTO MONDAY. AT THIS
TIME...IT APPEARS THAT THE HIGHEST POTENTIAL FOR SEVERE
THUNDERSTORMS(ESPECIALLY EASTERN SECTIONS) DURING THE LONGER
TERM SHOULD BE REALIZED FROM THURSDAY INTO THURSDAY
NIGHT...ESPECIALLY IF ENOUGH ADEQUATE ATMOSPHERIC MOISTURE
INTERACTS WITH SOMEWHAT FAVORABLE 0 TO 6 KM BULK SHEAR VALUES.
RECENT SPC 2ND DAY OUTLOOK(FOR THURSDAY) HAS A LARGE PORTION OF
EASTERN COLORADO COVERED WITH A SLIGHT RISK OF SEVERE
THUNDERSTORMS.
IN ADDITION...PRECIPITATION...HEAVY AT TIMES(WHICH WILL BE CAPABLE
OF PRODUCING FLOODING CONCERNS/ISSUES AT TIMES...ESPECIALLY OVER
THE AREA BURN SCARS)...IS ANTICIPATED AS THE UPPER SYSTEM IMPACTS
THE FORECAST DISTRICT FROM LATE THIS WEEK INTO EARLY NEXT WEEK. AS
ALWAYS...WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY.
IMPROVING METEOROLOGICAL CONDITIONS SHOULD THEN BY NOTED BY
TUESDAY AS THE CLOSED UPPER LOW IS PROJECTED TO MOVE EAST OF THE
FORECAST DISTRICT. TEMPERATURES ARE STILL EXPECTED TO RUN NEAR
LATE MAY CLIMATOLOGICAL AVERAGES DURING THE LONGER TERM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 523 AM MDT WED MAY 21 2014
MVFR CIGS WILL CONTINUE TO EXPAND ACROSS THE SOUTHEAST
PLAINS THROUGH MORNING...WITH SOME POCKETS OF IFR CIGS ACROSS THE
PIKES PEAK REGION AND ALONG THE LOWER EASTERN SLOPES OF THE
SOUTHEAST MOUNTAINS. COULD EVEN SEE SOME PATCHY FOG. STRATUS
SHOULD ERODE BY 17-18Z FOR MOST AREAS WITH ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING DURING THE EARLY AFTERNOON ACROSS THE
SOUTHEAST MOUNTAINS AND NORTHERN SLOPES OF THE RATON RIDGE. THESE
WILL BE CAPABLE OF PRODUCING VFR TO LOCAL MVFR CIGS/VIS. LARGE HAIL
AND ERRATIC WIND GUSTS TO AROUND 50 KTS WILL BE POSSIBLE NORTH OF A
LINE FROM KCOS THE KLHX TO NORTH OF KSPD. THREAT DIMINISHES AFTER
00Z FOR THE KCOS AND KPUB TAF SITES. KALS WILL REMAIN DRY TODAY
WITH VFR CONDITIONS...THOUGH EXPECT A RETURN OF SOUTHWEST WINDS 15-
30 KTS IN THE AFTERNOON. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON TODAY TO 8 PM MDT THIS EVENING FOR
COZ224.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
458 AM MDT WED MAY 21 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 458 AM MDT WED MAY 21 2014
...SEVERE THUNDERSTORMS POSSIBLE NORTHERN PORTIONS OF THE SOUTHEAST
PLAINS...CRITICAL FIRE WEATHER CONDITIONS EXPECTED ACROSS THE SAN
LUIS VALLEY...
UPPER LOW WILL STALL OUT OVER NEVADA TODAY BEFORE DROPPING SOUTHWARD
INTO SOUTHERN CA LATER TONIGHT. SOUTHERLY FLOW AHEAD OF THE SYSTEM
TODAY WILL START TO SHIFT SOME MID/HIGH LEVEL MOISTURE INTO THE
WESTERN MTS TODAY...BUT BY IN LARGE...LOWER LEVELS WILL REMAIN QUITE
DRY. WITH SOUTH TO SOUTHWEST WINDS INCREASING AGAIN ACROSS THE
SOUTHWEST MTS AND SAN LUIS VALLEY...EXPECT A RETURN OF CRITICAL FIRE
WEATHER CONDITIONS FOR THE SAN LUIS VALLEY WHERE FUELS ARE
CRITICALLY DRY. RAPID RATES OF FIRE SPREAD WILL BE POSSIBLE WITH
ANY FIRE STARTS AND CURRENT RED FLAG WARNING STILL LOOKS GOOD.
THERE COULD BE SOME ISOLATED HIGH BASED THUNDERSTORMS ALONG THE
CONTDVD TODAY...BUT THEY WILL BE FEW AND FAR BETWEEN...AND WITH
INVERTED V SOUNDINGS...MORE LIKELY TO PRODUCE GUSTY WINDS THAN MUCH
IN THE WAY OF RAINFALL.
DIFFERENT STORY WILL EXIST TODAY FOR THE SOUTHEAST PLAINS. LOW LEVEL
MOISTURE HAS SPREAD BACK IN WITH CURRENT DEW POINTS IN THE 50S FOR
THE LOWER ARKANSAS RIVER...WITH UPPER 40S FOR CANON CITY...AND EVEN
WOODLAND PARK SEEING LOWER 40 DEW POINTS. SOUTHERN I-25 CORRIDOR IS
STILL QUITE DRY WITH KTAD DEW POINT AT 13 AS OF 09Z. BOUNDARY WILL
CONTINUE TO PUSH SLOWLY SOUTHWARD THIS MORNING WITH STRATUS
EXPANDING ACROSS SOUTHEAST CO IN LIGHT UPSLOPE REGIME ALONG THE
LOWER EASTERN SLOPES OF TELLER/EL PASO COUNTY...THE LOWER WET
MOUNTAINS...AND THE NORTHERN SLOPES OF THE RATON RIDGE. THIS SHOULD
BURN OFF DURING THE LATE MORNING WITH DEW POINTS STAYING IN THE
UPPER 40S/LOWER 50S THROUGH EARLY AFTERNOON ACROSS THE MAJORITY OF
THE SOUTHEAST PLAINS. VORT MAX ACROSS NEW MEXICO WILL MOVE IN THIS
AFTERNOON...AND DRIER AIR WILL BEGIN TO MIX NORTHWARD OFF THE RATON
RIDGE. MAIN FACTOR DETERMINING EXTENT OF SEVERE WEATHER POTENTIAL
WILL BE HOW QUICKLY THESE DEW POINTS MIX OUT. HRRR AND RAP13 DROPS
DEW POINTS INTO THE UPPER 30S FOR THE I-25 CORRIDOR WITH 40S FARTHER
EAST BY 21Z. NAM12 AND LOCAL 4KM WRF KEEPS DEW POINTS IN THE LOWER
50S AT 21Z NORTHEAST OF A LINE FROM KCOS...TO KLHX...TO KSPD. SO
CAPES COULD BE AS LOW AS 500 J/KG ALONG THE I-25 CORRIDOR TO AROUND
1500 J/KG ACROSS KIOWA...BENT...PROWERS COUNTIES IF THE RAP IS
CORRECT. OR THEY COULD BE AROUND 1500+ J/KG IF THE NAM12 IS
CORRECT. EITHER WAY...0-6KM SHEARS WILL BE RUNNING AROUND 40-50
KTS...OR EVEN A LITTLE BETTER IF LOW LEVEL WINDS STAY OUT OF THE
EAST...WHICH WOULD SUPPORT DEVELOPMENT OF SUPERCELL THUNDERSTORMS.
BEST CHANCES FOR SEVERE LOOK TO BE ACROSS NORTHERN SECTIONS OF THE
SOUTHEAST PLAINS...WHERE HIGHER DEW POINTS ARE MORE LIKELY TO STAY
IN THE LONGEST. INITIATION MAY OCCUR ALONG THE NORTHERN SLOPES OF
THE RATON MESA AROUND 1 PM...WITH THUNDERSTORMS SPREADING/DEVELOPING
NORTHWARD ACROSS THE SOUTHEAST PLAINS THROUGH THE AFTERNOON.
MAJORITY OF THE ACTIVITY MOVES OUT OF THE AREA BY 00Z AS VORT MAX
LIFTS NORTHWARD. LARGE HAIL AND DAMAGING WINDS WILL BE THE MOST
LIKELY SEVERE THREAT...ESPECIALLY TO THE NORTH OF THE ARKANSAS
RIVER. IF DEW POINTS CAN STAY HIGH ENOUGH...THUS...LCLS LOW
ENOUGH...THERE COULD BE ENOUGH LOW LEVEL HELICITY FOR AN ISOLATED
TORNADO. THIS WOULD BE MORE LIKELY TO OCCUR ALONG THE PALMER DIVIDE
AND KIOWA COUNTY...BUT THREAT FOR THIS APPEARS ON THE LOWER SIDE OF
THE SPECTRUM AT THIS POINT. POTENTIAL FOR DAMAGING WIND GUSTS WILL
EXTEND FARTHER SOUTHWARD ACROSS THE SOUTHEAST PLAINS THAN HAIL
THREAT DUE TO HIGHER AVAILABLE DOWNDRAFT CAPE. WILL LIKELY PLAY THE
SEVERE THREAT AREA NORTHEAST OF A LINE FROM COLORADO SPRINGS...TO LA
JUNTA...TO TWO BUTTES.
FINAL CONCERN IS FOR POTENTIAL FOR HEAVY RAINFALL ON THE BURN SCARS
THIS AFTERNOON...PARTICULARLY ACROSS WALDO AND BLACK FOREST. WINDOW
FOR GREATEST THREAT WILL BE FROM 2 PM TO 6 PM...PROBABLY CENTERED
MORE IN THE 3 TO 5 PM RANGE FOR WALDO. AGAIN...STRENGTH OF
UPDRAFTS/POTENTIAL RAINFALL EFFICIENCIES WILL DEPEND ON HOW MUCH LOW
LEVEL MOISTURE STAYS IN. HUNCH IS THAT HIGHER TERRAIN WILL MIX OUT
AT LEAST SOME OF THE LOW LEVEL MOISTURE AND LCLS WILL BE UP AROUND
11-12KFT MSL...WHICH WILL ALLOW FOR SOME EVAPORATION BELOW CLOUD
BASE. ALTHOUGH THREAT FOR FLASH FLOOD PRODUCING RAINFALL IS THERE
TODAY...THINK THE THREAT IS BELOW A 40 PERCENT PROBABILITY. MORE
LIKELY SCENARIO IS FOR SOME RAINFALL AMOUNTS GENERALLY IN THE
.10 TO .40 RANGE...WHICH COULD MEAN SOME FLOOD ADVISORY RAINFALL
CAUSING MINOR RUN OFF FOR THE WALDO BURN SCAR. MAJORITY OF THE HIGH
RES MODELS SUGGEST THE LESSER IMPACT SCENARIO...BUT SITUATION WILL
REQUIRE CLOSE MONITORING THROUGH THE AFTERNOON AND EARLY EVENING
HOURS.
THUNDERSTORMS WILL COME TO AN END DURING THE EVENING FOR MOST
AREAS...WITH ANOTHER INTRUSION OF STRATUS TOWARDS MORNING ACROSS
NORTHERN PORTIONS OF THE SOUTHEAST PLAINS. -KT
.AVIATION... MVFR CIGS WILL CONTINUE TO EXPAND ACROSS THE SOUTHEAST
PLAINS THROUGH MORNING...WITH SOME POCKETS OF IFR CIGS ACROSS THE
PIKES PEAK REGION AND ALONG THE LOWER EASTERN SLOPES OF THE
SOUTHEAST MOUNTAINS. COULD EVEN SEE SOME PATCHY FOG. STRATUS
SHOULD ERODE BY 17-18Z FOR MOST AREAS WITH ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING DURING THE EARLY AFTERNOON ACROSS THE
SOUTHEAST MOUNTAINS AND NORTHERN SLOPES OF THE RATON RIDGE. THESE
WILL BE CAPABLE OF PRODUCING VFR TO LOCAL MVFR CIGS/VIS. LARGE HAIL
AND ERRATIC WIND GUSTS TO AROUND 50 KTS WILL BE POSSIBLE NORTH OF A
LINE FROM KCOS THE KLHX TO NORTH OF KSPD. THREAT DIMINISHES AFTER
00Z FOR THE KCOS AND KPUB TAF SITES. KALS WILL REMAIN DRY TODAY
WITH VFR CONDITIONS...THOUGH EXPECT A RETURN OF SOUTHWEST WINDS 15-
30 KTS IN THE AFTERNOON. -KT
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 458 AM MDT WED MAY 21 2014
NOT MANY ADJUSTMENTS NEEDED FOR THE LONGER TERM AS UNSETTLED
PATTERN IS STILL ANTICIPATED WITH LONGER TERM ISSUES REMAINING
POPS...SEVERE WEATHER THREAT AT TIMES WITH INITIAL LONGER TERM
FOCUS FOR SEVERE WEATHER FROM THURSDAY INTO THURSDAY
NIGHT...LOCALLY HEAVY RAINFALL AND ASSOCIATED BURN SCAR FLOODING
THREAT AND POPS.
RECENT LONGER TERM FORECAST MODEL SOUNDINGS AND COMPUTER
SIMULATIONS CONTINUE TO SUGGEST THAT CLOSED UPPER LOW LOCATED
OVER SOUTHERN NEVADA AT 00Z FRIDAY WILL SHIFT INTO THE 4-CORNERS
REGION BY 00Z SUNDAY AND THEN SLOWLY MOVES ACROSS SOUTHERN
COLORADO INTO MONDAY MORNING BEFORE MOVING EAST OF THE FORECAST
DISTRICT BY MONDAY EVENING.
UNSETTLED METEOROLOGICAL CONDITIONS(PRIMARILY IN THE FORM OF
RAIN...HEAVY AT TIMES AS WELL AS STRONG TO SEVERE STORMS AT
TIMES) ARE ANTICIPATED FROM THURSDAY INTO MONDAY. AT THIS
TIME...IT APPEARS THAT THE HIGHEST POTENTIAL FOR SEVERE
THUNDERSTORMS(ESPECIALLY EASTERN SECTIONS) DURING THE LONGER
TERM SHOULD BE REALIZED FROM THURSDAY INTO THURSDAY
NIGHT...ESPECIALLY IF ENOUGH ADEQUATE ATMOSPHERIC MOISTURE
INTERACTS WITH SOMEWHAT FAVORABLE 0 TO 6 KM BULK SHEAR VALUES.
RECENT SPC 2ND DAY OUTLOOK(FOR THURSDAY) HAS A LARGE PORTION OF
EASTERN COLORADO COVERED WITH A SLIGHT RISK OF SEVERE
THUNDERSTORMS.
IN ADDITION...PRECIPITATION...HEAVY AT TIMES(WHICH WILL BE CAPABLE
OF PRODUCING FLOODING CONCERNS/ISSUES AT TIMES...ESPECIALLY OVER
AREA BURN SCARS)...IS ANTICIPATED AS THE UPPER SYSTEM IMPACTS THE
FORECAST DISTRICT FROM LATE THIS WEEK INTO EARLY NEXT WEEK. AS
ALWAYS...WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY.
IMPROVING METEOROLOGICAL CONDITIONS SHOULD THEN BY NOTED BY
TUESDAY AS THE CLOSED UPPER LOW MOVES EAST OF THE FORECAST
DISTRICT. TEMPERATURES ARE STILL PROJECTED TO RUN NEAR LATE
MAY CLIMATOLOGICAL AVERAGES DURING THE LONGER TERM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 458 AM MDT WED MAY 21 2014
MVFR CIGS WILL CONTINUE TO EXPAND ACROSS THE SOUTHEAST
PLAINS THROUGH MORNING...WITH SOME POCKETS OF IFR CIGS ACROSS THE
PIKES PEAK REGION AND ALONG THE LOWER EASTERN SLOPES OF THE
SOUTHEAST MOUNTAINS. COULD EVEN SEE SOME PATCHY FOG. STRATUS
SHOULD ERODE BY 17-18Z FOR MOST AREAS WITH ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING DURING THE EARLY AFTERNOON ACROSS THE
SOUTHEAST MOUNTAINS AND NORTHERN SLOPES OF THE RATON RIDGE. THESE
WILL BE CAPABLE OF PRODUCING VFR TO LOCAL MVFR CIGS/VIS. LARGE HAIL
AND ERRATIC WIND GUSTS TO AROUND 50 KTS WILL BE POSSIBLE NORTH OF A
LINE FROM KCOS THE KLHX TO NORTH OF KSPD. THREAT DIMINISHES AFTER
00Z FOR THE KCOS AND KPUB TAF SITES. KALS WILL REMAIN DRY TODAY
WITH VFR CONDITIONS...THOUGH EXPECT A RETURN OF SOUTHWEST WINDS 15-
30 KTS IN THE AFTERNOON. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM NOON TODAY TO 8 PM MDT THIS EVENING FOR
COZ224.
&&
$$
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
936 AM EDT WED MAY 21 2014
.SYNOPSIS...
A WARM FRONT FROM THE GREAT LAKES TO VIRGINIA WILL MOVE TO THE
SOUTHERN NEW JERSEY AND DELAWARE COASTS TONIGHT WHERE LOW PRESSURE
FORMS AND HEADS OUT TO SEA. A COLD FRONTAL PASSAGE FOLLOWS LATER
THURSDAY NIGHT. HIGH PRESSURE IN THE MIDWEST ON FRIDAY FINALLY
ARRIVES ALONG THE MID ATLANTIC COAST ON SUNDAY THEN BECOMES PART OF
THE BERMUDA HIGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS CONTINUE TO STREAM DOWN FROM THE NORTHWEST INTO
SOUTHEASTERN PA, SOUTHERN NJ, DE AND EASTERN MD THIS MORNING IN
ASSOCIATION WITH A MID LEVEL SHORTWAVE. THERE HAVE BEEN A FEW
STRIKES OF LIGHTNING TO THE NORTHWEST OF THE AREA SO A RUMBLE OF
THUNDER MAY STILL BE HEARD AS THE SHOWERS MOVE THROUGH.
THE BIG STORY OF TODAY WILL BE THE WARM FRONT AND ASSOCIATED
SHOWER AND THUNDERSTORM ACTIVITY IN THE WARM SECTOR. STILL LOOKS
TO BE SOME INSTABILITY, HOWEVER THERE ARE A FEW DIFFERENCES FROM
THE PREVIOUS MODEL RUNS WITH REGARDS TO THE STRONG STORM THREAT.
FIRST, BOTH THE RAP AND THE NAM ARE SHOWING A DRIER LOW LEVEL
PRIMARILY DUE TO A LATER ARRIVAL OF THE WARM FRONT, AND THUS LATER
ONSET OF LOW LEVEL MOISTURE ADVECTION. THIS, COMBINED WITH A
POSSIBLE WEAK INVERSION AROUND 800 MB, HAS LEAD TO LOWER ML CAPE
VALUES, NOW GENERALLY 100 J/KG OR LESS (EXCEPT FOR SOUTHERN
DELMARVA). HOWEVER, IN DELMARVA, IT STILL LOOKS LIKE K INDEX WILL
BE IN THE LOW 30S, LI WILL BE NEAR ZERO BY MID DAY. THUS, WILL
CONTINUE THE MENTION IN THE HWO FOR STRONG STORMS (PRIMARILY A
WIND THREAT GIVEN A RELATIVELY HIGH MELTING LEVEL). WITH THE LATER
ONSET OF MOISTURE ADVECTION, PWAT VALUES THROUGH THIS TIME LOOK TO
BE AT OR LESS THAN 1.5 IN, WHICH IS STILL ABOVE NORMAL, SO COULD
STILL SEE SOME HEAVY RAIN. AS WITH THE WIND THREAT, THIS THREAT IS
PRIMARILY FOR DELMARVA, WHERE THE 3 HR FLASH FLOOD GUIDANCE VALUES
ARE GENERALLY ABOVE 3 IN. THUS, DO NOT EXPECT A BIG FLOODING
THREAT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
SHOULD CONTINUE TO SEE INCREASING LOW LEVEL MOISTURE THROUGH THIS
PERIOD, SO EXPECT LOW CLOUDS, AND POSSIBLY SOME PATCHY FOG. CHANCES
FOR SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE THROUGH THIS
PERIOD, THOUGH THERE MAY BE A BRIEF LULL LATE OVERNIGHT TONIGHT IN
BETWEEN THE WARM FRONT LIFTING NORTH OF THE REGION, AND COLD FRONT
EXPECTED LATER ON THURSDAY.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
5-WAVE GUIDANCE SHOWS RELATIVELY WEAK TROUGHING ACROSS THE EAST WITH
WEAK RIDGING ACROSS THE CENTRAL PORTION OF THE U.S. TO START THE
PERIOD. THE TROUGHING TRIES TO BECOME BETTER ESTABLISHED THROUGH THE
THE WEEKEND BEFORE RIDGING KICKS IT TO THE EAST BY EARLY NEXT WEEK.
A WEAK HIGH LATITUDE OMEGA BLOCK LOOKS POSSIBLE THROUGH THE END OF THE
WEEK AND HENCE THE AMOUNT OF UNSETTLED WEATHER EXPECTED THROUGH THE
FIRST HALF OF THE LONGTERM PERIOD.
SURFACE WARM FRONT SHOULD BE MOVING THROUGH THE REGION THURSDAY
MORNING AS A MID-LEVEL SHORTWAVE MOVES ALONG THE BOUNDARY WITHIN THE
NORTHWEST FLOW ALOFT. THIS COULD CONTINUE TO USHER THE DECAYING
GREAT LAKES MCS THROUGH NORTHERN PENNSYLVANIA BEFORE IT DIVES
FURTHER SOUTHEAST, POSSIBLY CLIPPING OUR NORTHERN AND WESTERN ZONES.
WITH THIS FEATURE THROUGH BY LATE THURSDAY MORNING THERE SHOULD BE A
LULL IN THE ACTION, AT LEAST ACROSS OUR SOUTHERN ZONES. MORE
MID-LEVEL SHORTWAVES WILL MOVE THROUGH IN THE CYCLONIC FLOW ALOFT
AND COULD TRIGGER MORE SHOWERS WITH EMBEDDED THUNDER ACROSS OUR
NORTHERN ZONES. LOW PRESSURE MOVES THROUGH THE GREAT LAKES LATER ON
THURSDAY AND PULLS A COLD FRONT THROUGH OUR REGION DURING THE
EVENING HOURS WITH MORE SHOWERS AND POSSIBLE THUNDERSTORMS.
FRIDAY SHOWS ANOTHER BATCH OF EMBEDDED MID-LEVEL ENERGY TRAVERSING
THE REGION WHICH COULD TOUCH OFF SOME SCATTERED INSTABILITY SHOWERS
WITH THE MID-LEVEL COLD POOL NOT TOO FAR REMOVED TO OUR NORTH. MUCH
CAN BE SAID ABOUT SATURDAY THAT CAN BE SAID ABOUT FRIDAY SO WE
CONTINUE WITH THE CHANCE POPS.
THE "BLOCKY" PATTERN BEGINS TO BREAK DOWN, BETTER ESTABLISHED
TROUGHING MOVING TOWARDS THE EAST, HEADING INTO THE LATER PART OF
THE WEEKEND. DEEP LAYER RIDGING ENTERS FROM THE WEST AND WE SHOULD
DRY OUT NICELY SUNDAY AND MEMORIAL DAY. SURFACE HIGH PRESSURE MOVES
OFFSHORE BY TUESDAY OF NEXT WEEK GIVING WAY TO A STRONG RETURN FLOW
AND ANOTHER INFLUX OF TROPICAL MOISTURE. THE NEXT SYSTEM LOOKS TO
ENTER FROM THE SOUTHWEST LATER ON TUESDAY WITH MORE SHOWERS.
TEMPERATURES THROUGHOUT THE PERIOD WILL FLUCTUATE TOWARDS BELOW NORMAL ON
FRIDAY AND SATURDAY CLIMBING AGAIN TO NORMAL ON SUNDAY AND THEN
SEVERAL DEGREES ABOVE NORMAL ON MONDAY AND TUESDAY.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CEILINGS WILL SLOWLY LOWER THROUGH THE DAY, WITH CONDITIONS
DETERIORATING TO MVFR AFTER 21Z. HOWEVER, LOCALIZED MVFR VISIBILITIES
ARE POSSIBLE AHEAD OF 21Z, IN THE VICINITY OF ANY THUNDERSTORMS.
SOME SHOWERS ARE MOVING THE REGION WITH SOME MVFR CONDITIONS
OCCURRING FOR A BRIEF PERIOD OF TIME. THESE SHOWERS WILL CONTINUE
TO MOVE TO THE SOUTHEAST AND ARE PRIMARILY ONLY AFFECTING KRDG,
KILG AND WILL MOVE TOWARD KMIV, POSSIBLY AFFECTING KACY AS WELL.
WE EXPECT A PERIOD OF SHOWERS TO ARRIVE AROUND MID DAY, BEFORE WE
COULD SEE ANOTHER ROUND OF THUNDERSTORMS, THIS TIME GENERALLY FOR
DE AND MD (INCLUDING KILG) AFTER 18Z. NOTE THAT THERE IS A SMALL
RISK OF THUNDERSTORMS ACROSS THE REGION. HOWEVER, CONFIDENCE IS
ONLY HIGH ENOUGH TO INCLUDE A PROB30 GROUP AT THE KILG TAF AT THIS
TIME.
A COMBINATION OF LOWERING CEILINGS AND POSSIBLY SOME BR DEVELOPMENT
WILL LEAD TO WIDESPREAD MVFR WITH LOCALIZED IFR CONDITIONS AFTER
21Z, CONTINUING THROUGH WEDNESDAY NIGHT.
OUTLOOK...
THURSDAY...MVFR OR LOWER IN SCATTERED SHOWERS AND THUNDERSTORMS.
BETTER CHANCE FOR SHOWERS WILL BE NORTH OF PHL EARLY IN THE DAY.
COLD FRONT PASSAGE LATER IN THE DAY WILL BACK WINDS TOWARDS THE
WEST-NORTHWEST.
FRIDAY - SATURDAY...MVFR OR LOWER IN SCATTERED SHOWERS. LESS OF A
CHANCE OF THUNDER BOTH DAYS WHEN COMPARED TO THURSDAY.
SUNDAY...VFR.
&&
.MARINE...
WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY
CONDITIONS. WINDS MAY OCCASIONALLY GUST NEAR 20KT THIS AFTERNOON AND
EVENING ESPECIALLY IN THE VICINITY OF ANY THUNDERSTORMS. AREAS OF
FOG COULD DEVELOP AFTER SUNSET TONIGHT, PRIMARILY OVER THE DELAWARE
BAY AND THE ATLANTIC COASTAL WATERS FROM THE DELAWARE BEACHES UP TO
ATLANTIC CITY.
OUTLOOK...
THURSDAY - SUNDAY...SUB-SCA CONDITIONS ARE EXPECTED. SHOWERS AND
THUNDERSTORMS ARE POSSIBLE EACH DAY THROUGH SATURDAY.
&&
.EQUIPMENT...
THE KDIX RADAR REMAINS OUT OF SERVICE. TECHNICIANS ARE CONTINUING TO
WORK HARD ON RESOLVING THE ISSUE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...JOHNSON/MEOLA
SHORT TERM...JOHNSON
LONG TERM...HEAVENER
AVIATION...HEAVENER/JOHNSON/MEOLA
MARINE...HEAVENER/JOHNSON
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1040 AM EDT WED MAY 21 2014
.UPDATE...
AVIATION SECTIONS UPDATED.
&&
.SYNOPSIS...
ISSUED AT 325 AM EDT WED MAY 21 2014
SCATTERED SHOWERS AND SEVERE THUNDERSTORMS WILL BE POSSIBLE TODAY
AND THIS EVENING AS A COLD FRONT SLIDES ACROSS CENTRAL INDIANA.
TEMPS WILL DECREASE A BIT DURING THE SHORT TERM PERIOD IN THE WAKE
OF COLD FRONT...BUT CONDITIONS WILL BE DRY THROUGH NEXT TUESDAY
WITH HIGH PRESSURE OVER THE AREA. THE NEXT CHANCE FOR SHOWERS AND
THUNDERSTORMS WILL BE NEXT TUESDAY NIGHT/WEDNESDAY WHEN THE NEXT
UPPER LOW AND VORT MAX ENTER THE REGION.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 950 AM EDT WED MAY 21 2014
FORECAST IS PRETTY MUCH ON TRACK. LOWERED POPS THIS MORNING ACROSS
THE SOUTHWEST FORECAST AREA SINCE THUNDERSTORMS SHOULD BE CLOSER TO
THE BOUNDARY ACROSS NORTHERN INDIANA. LEFT POPS ALONE THIS
AFTERNOON. STORM PREDICTION CENTER STILL INDICATES A RISK FOR SEVERE
STORMS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY THREATS.
LEFT TEMPERATURES ALONE FOR NOW AND WILL SEE IF CONVECTION OR CLOUDS
FROM CONVECTION REQUIRE A CHANGE LATER THIS AFTERNOON.
PREVIOUS DISCUSSION FOLLOWS...
THE MAIN FOCUS OF THE NEAR TERM IS THE THREAT FOR SEVERE WEATHER.
SPC CONTINUES TO KEEP ALL OF CENTRAL INDIANA UNDER A SLIGHT RISK
FOR DAY 1.
RIDGE ALOFT WILL BREAK DOWN AS UPPER LEVEL LOW ENTERS THE GREAT
LAKES REGION TODAY. MEANWHILE...A COLD FRONT AT THE SURFACE WILL
TRACK ACROSS CENTRAL INDIANA...TRIGGERING SHOWERS AND
THUNDERSTORMS ALONG AND AHEAD OF IT. MLCAPES REMAIN IMPRESSIVE
ACROSS THE FORECAST AREA IN THE 2000 TO 3000 J/KG RANGE. MID LEVEL
LAPSE RATES WILL APPROACH THE 7C MARK BY THIS EVENING. THIS MEANS
THE SOUTH/SOUTHEASTERN PORTIONS OF FORECAST AREA WILL HAVE HIGHEST
THREAT FOR SEVERE DEVELOPMENT WITH BEST INSTABILITY OF THE DAY.
LARGE HAIL WILL BE A HUGE THREAT. IN ADDITION...STRONG WESTERLY SPEED
SHEAR WILL BE CONDUCIVE TO DAMAGING WINDS. HIGHLIGHTED THE
SOUTHEAST QUADRANT OF FORECAST AREA BY CARRYING LIKELY POPS DURING
THIS AFTERNOON AND EVENING. LATEST MODELS HAVE COLD FRONT ENTERING
THE NORTHWESTERN COUNTIES AROUND WED 18Z AND ARE TRENDING TOWARD A
VERY SLOW PROGRESSION OF THE FRONT THROUGH THE DAY.
TEMPS...TRENDED SLIGHTLY ABOVE GUIDANCE FOR TODAY. WARM
SOUTHWESTERLY FLOW AHEAD OF COLD FRONT SHOULD RESULT IN HIGH TEMPS
TOPPING OFF IN THE LOW TO MID 80S.
CURRENTLY...TEMPS ACROSS THE AREA ARE GENERALLY IN THE UPPER 70S
WITH DEWPOINTS IN THE UPPER 50S/LOW 60S. WINDS ARE SOUTHWESTERLY
AT 5 TO 10 MPH AND GUSTING TO 18 MPH.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
ISSUED AT 325 AM EDT WED MAY 21 2014
HELD ONTO WIDESPREAD PRECIP CHANCES UP TO THU 06Z ACROSS MOST OF
FORECAST AREA DUE TO THE SLOW PROGRESSION OF COLD FRONT AND
LINGERING MOISTURE/ISENTROPIC LIFT. ANTICIPATE QUICK CLEARING
AFTER THAT AND THEN A DRY FORECAST THROUGH THE REMAINDER OF SHORT
TERM PERIOD AS HIGH PRESSURE BUILDS BACK INTO THE REGION.
STUCK CLOSE TO GUIDANCE IN REGARD TO TEMPS FOR DURATION OF SHORT
TERM PERIOD. TEMPS BECOME CLOSER TO NORMAL IN WAKE OF
AFOREMENTIONED COLD FRONT...AND MODELS SEEM TO BE PICKING UP ON
THE TRANSITION WELL. HIGHS WILL GENERALLY BE IN THE LOW 70S OVER
THE NORTHERN COUNTIES...TO MID TO UPPER 70S ACROSS THE SOUTHERN
COUNTIES. OVERNIGHT LOWS WILL DIP BACK INTO THE 50S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 237 PM EDT TUE MAY 20 2014
MAIN FOCUS ON THE EXTENDED WILL BE ON TEMPERATURES AS MEMORIAL
DAY WEEKEND IS LOOKING VERY PROMISING FOR OUTDOOR ACTIVITIES
ACROSS CENTRAL INDIANA.
THE MOST CONSISTENT ECMWF AND ECMWF ENSEMBLE MEANS ALONG WITH THE
00Z GFS START THE EXTENDED OFF WITH BROAD SURFACE HIGH PRESSURE
ACROSS THE GREAT LAKES AND OHIO VALLEY AND A SHARP UPPER RIDGE
ACROSS THE MISSISSIPPI VALLEY. THE SURFACE HIGH WILL SHIFT EAST TO
THE APPALACHIANS SATURDAY NIGHT AND TO THE EASTERN SEABOARD SUNDAY.
THIS WILL ALLOW FOR A MODEST SOUTHERLY FLOW OF WARMER AIR INTO THE
THE OHIO VALLEY THROUGH NEXT WEEK.
EXPECT THE WEEKEND TO BE DRY WITH A FEW THUNDERSTORMS POSSIBLE EARLY
NEXT WEEK WITH LOW LEVEL MOISTURE INCREASING AND IMPULSES ROUNDING
THE BASE OF AN UPSTREAM UPPER LOW ACROSS THE CENTRAL PLAINS. FOR
NOW...WILL KEEP MEMORIAL DAY DRY AND GO WITH SMALL THUNDERSTORM
CHANCES BY TUESDAY.
REGIONAL ALLBLEND TEMPERATURES LOOK REASONABLE GIVEN THE SOUTHERLY
FLOW AND UPPER RIDGE PATTERN WITH AFTERNOON HIGHS STARTING OFF NEAR
NORMAL IN THE 70S ON SATURDAY AND CLIMBING TO THE MID 80S BY MONDAY.
&&
.AVIATION /DISCUSSION FOR THE 211500Z IND TAF UPDATE/...
ONGOING TAFS IN GOOD SHAPE. VFR CONDITIONS WILL CONTINUE INTO THE
AFTERNOON. CONVECTIVE TEMPS SHOULD BE REACHED EARLY THIS
AFTERNOON. HRRR CONTINUES TO SUGGEST 19Z AS CONVECTIVE INITIATION
TIME. THUS HAVE AS TRIMMED VCTS MENTION TO AFTER 18Z.
PREVIOUS DISCUSSION BELOW
/DISCUSSION FOR THE 211200Z TAF ISSUANCE/...
ISSUED AT 632 AM EDT WED MAY 21 2014
WITH STRONG INSTABILITY AND SUFFICIENT MOISTURE ALONG AND AHEAD OF
AN ADVANCING COLD FRONT...EXPECT STRONG CONVECTION TO INITIATE
MAINLY AFTER 18Z AS CONVECTIVE TEMPERATURES IN THE LOWER 80S ARE
REACHED. THE FRONT SHOULD REACH LAF NEAR 22Z...IND AND HUF NEAR 06Z
THURSDAY AND BMG TOWARD 12Z THURSDAY. ALTHOUGH...CONFIDENCE IN EXACT
TIMING IS NOT GREAT. ALSO...THE RAPID REFRESH REFLECTIVITY PROGS
INITIATE MOST OF THE CONVECTION SOUTH OF LAF...SO WILL ONLY GO WITH
VCTS AT LAF AND 3 HOUR TEMPO GROUPS ELSEWHERE. WILL ALSO ADD TEMPO
THUNDERSTORM WIND GUSTS TO 40 KNOTS...AND HIGHER GUSTS ARE ALSO
POSSIBLE.
FLYING CONDITIONS OUTSIDE OF STORMS SHOULD BE MOSTLY VFR THIS
MORNING BUT...COULD SEE SOME MVFR MAINLY BEFORE 15Z. WITHIN
THUNDERSTORMS...CONDITIONS SHOULD BE MVFR AND POSSIBLY WORSE.
WINDS WILL BE SOUTHWEST AHEAD OF THE FRONT AND SWITCH TO WEST
AS IT GETS CLOSER AND THEN NORTHWEST AND NORTH BEHIND THE FRONT.
WINDS SHOULD BE 15 KNOTS OR LESS TODAY AND LESS THAN 10 KNOTS AFTER
00Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...TDUD/50
SHORT TERM...TDUD
LONG TERM....MK
AVIATION...MK
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
654 AM CDT WED MAY 21 2014
.UPDATE...
ISSUED AT 442 AM CDT WED MAY 21 2014
CONVECTION ALONG THE FRONT IS DISSIPATING MUCH FASTER THAN
PREVIOUSLY THOUGHT AS THE FORCING ALOFT WEAKENS. THE MOST RECENT
RAP TRENDS INDICATE DOWNWARD MOTION GETTING STRONGER ACROSS
EASTERN IOWA OVER THE NEXT SEVERAL HOURS.
THE FORECAST THROUGH SUNRISE AND THE MORNING COMMUTE HAS BEEN
UPDATED TO REFLECT THESE TRENDS.
&&
.SYNOPSIS...
ISSUED AT 330 AM CDT WED MAY 21 2014
06Z SFC ANALYSIS HAS A FRONT FROM NORTHEAST ILLINOIS INTO
NORTHEAST KANSAS. SEVERAL LOWS WERE ALONG THE FRONT FROM NORTHEAST
KANSAS INTO SOUTHEAST IOWA. A STRONGER COLD FRONT RAN FROM WESTERN
LAKE SUPERIOR INTO NORTHERN KANSAS. DEW POINTS WERE IN THE 60S
FROM THE DEEP SOUTH INTO THE WESTERN GREAT LAKES WITH 40S AND 50S
FROM THE NORTHERN PLAINS INTO THE UPPER MIDWEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT WED MAY 21 2014
WEAK LOW PRESSURE MOVING ALONG THE FRONT HELPED INITIATE NEW
STORMS ACROSS THE CENTRAL PARTS OF THE AREA. ALTHOUGH NOT SLOW
MOVING...THESE STORMS PRODUCED COPIOUS AMOUNTS OF RAINFALL IN A
VERY SHORT TIME PERIOD.
TRENDS FROM THE RAP INDICATE THE CURRENT STORMS ACROSS THE AREA
WILL CONTINUE TO MOVE EAST IN A NARROW BAND AND SLOWLY DISSIPATE
THROUGH SUNRISE AS THE OVERALL FORCING WEAKENS.
MUCH OF THE MORNING AND AFTERNOON HOURS ARE EXPECTED TO REMAIN DRY
UNTIL ANOTHER ROUND OF FORCING ARRIVES DURING PEAK HEATING. NEW
STORMS SHOULD THEN DEVELOP ACROSS THE FAR SOUTH CLOSE TO THE
FRONTAL BOUNDARY.
TONIGHT...THE AFTERNOON STORMS THAT DEVELOP WILL CONTINUE ACROSS
THE FAR SOUTH DURING THE EVENING BEFORE DISSIPATING. BOUNDARIES
FROM THIS CONVECTION ALONG WITH THE COLD FRONT WILL ALLOW A NEW
NOCTURNAL THUNDERSTORM COMPLEX TO DEVELOP IN NORTHWEST MISSOURI
AND THEN MOVE GENERALLY EAST SOUTHEAST THROUGH SUNRISE THURSDAY.
THE AREA THAT HAS THE BEST CHANCES FOR RAIN WILL BE THE FAR SOUTH
AND THE RAINFALL MAY BE LOCALLY HEAVY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED MAY 21 2014
THURSDAY THROUGH FRIDAY NIGHT THE COLD FRONT WILL REMAIN ACROSS
NORTHERN MISSOURI. INTERNALLY...THE MODELS ARE INDICATING THE THE
ACTIVE ZONE FOR NOCTURNAL THUNDERSTORM COMPLEXES WILL BE CLOSE TO
THE AREA.
THE OVERALL MOISTURE AND FORCING BEING SUGGESTED BY THE MODELS
INDICATES THAT A NOCTURNAL THUNDERSTORM COMPLEX MAY BRUSH THE FAR
SOUTHWEST/SOUTH THURSDAY/THURSDAY NIGHT BUT THEN PUSH THE FRONT
FURTHER TO THE SOUTH/WEST FOR FRIDAY AND FRIDAY NIGHT.
TEMPERATURES WILL BE CLOSE TO NORMAL.
SATURDAY ON...
THE MODEL CONSENSUS HAS MAINLY DRY CONDITIONS ON SATURDAY AS THE
BETTER MOISTURE AND FORCING REMAIN WEST OF THE AREA. TEMPERATURES
WILL BE CLOSE TO NORMAL.
STARTING SATURDAY NIGHT AND CONTINUING THROUGH TUESDAY THE MODEL
CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS EACH DAY. WILL IT RAIN
CONTINUOUSLY THE ENTIRE TIME. NO. HOWEVER...THE BIG PICTURE
INDICATES THE WEATHER PATTERN WILL BE TURNING MORE ACTIVE WITH
SOUTHWEST FLOW ALOFT DEVELOPING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 643 AM CDT WED MAY 21 2014
GENERALLY VFR CONDITIONS EXPECTED THROUGH THE TAF CYCLE. PATCHY
SHALLOW FOG NORTH OF I-80 WITH VARIABLE VSBYS FROM LIFR TO MVFR
WILL DISSIPATE NEXT 1-2 HOURS WITH INCREASING NORTH WINDS. COLD
FRONT TO SAG SOUTH OF KMLI AND KBRL BY MIDDAY WITH ANY SHOWERS
AND STORMS THIS AFTERNOON STAYING SOUTH OF KBRL. NORTHERLY
WINDS WILL INCREASE AT TERMINALS TO AROUND 10-15 KTS BY MIDDAY
WITH SOME LOCAL GUSTS TO NEAR 20 KTS POSSIBLE AT TIMES OVER
NORTHEAST IA. NORTHERLY WINDS THEN DECREASE BELOW 10 KTS TONIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...08
SHORT TERM...08
LONG TERM...08
AVIATION...05
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
635 AM EDT Wed May 21 2014
...Updated Aviation Discussion...
.SHORT TERM (Now through Thursday)...
Issued at 300 AM EDT Wed May 21 2014
...Severe Storms with Strong Wind Gusts Possible This Afternoon and
Evening...
Storms are firing early this morning on the northern edge of a ridge
anchored over Louisiana. Current trajectory of these storms should
keep precipitation away from our area this morning. However leftover
boundaries and an approaching cold front should provide the focus
for new storm development later this afternoon. Soundings continue
to advertise plenty of instability, with our high temperatures
forecast to reach the 80s, perhaps even upper 80s for some of our
warm spots along and west of I-65. That ridge will provide a cap on
development for most of the day here, but forecast soundings
indicate it will weaken as cooler air moves in here from the west
northwest flow aloft.
If this cap break happens earlier in the afternoon, we would see
some scattered storms develop. However still think the most likely
scenario will be for storms to develop first across central Indiana,
closer to the front and those boundaries mentioned above. These
storms would then organize into a line and push into our southeast
Indiana counties and Kentucky Bluegrass counties late in the
afternoon and evening hours. Hi-res WRF-NMM and ARW have backed off
on this scenario, instead opting for more widely scattered
convection areawide, whereas the local WRF fits our thinking.
Forecast soundings indicate downdraft CAPEs in the 1000-1500 range
ahead of this line, thus the main threat with these storms would be
damaging wind gusts. Secondary threats would be frequent to
excessive cloud to ground lightning as well as brief heavy rainfall.
That cold front will drift into the northern forecast area
overnight. Moisture pooling around, precipitable waters of 1.4-1.7
inches, may allow for additional storm development through the
night, but will limit overnight pops into the isolated/low-end
chance range. The front will continue southward during the day
Thursday. New convective development during the day will depend
greatly on what happens overnight. Think the most likely scenario is
enough of a break though to allow temperatures again to rise into
the 80s and allow storms to develop along the frontal boundary/old
outflow boundaries over south central Kentucky in the afternoon.
These storms once again could become severe, with damaging winds
again the primary threat.
.LONG TERM (Thursday night through Tuesday)...
Issued at 250 AM EDT Wed May 21 2014
Upper air pattern at 500mb late Thursday will feature ridging over
the plains, sandwiched between a deep nearly cutoff low near Las
Vegas and a shallow trough moving across the Great Lakes. Surface
high pressure of Canadian origin will build east towards Illinois,
pushing a weakening cold front south into Tennessee. Scattered
storms expected across southern Kentucky will diminish Thursday
evening with the loss of daytime heating.
Although the remnants of this front will stall across Tennessee and
extreme western Kentucky Friday, giving them scattered storms,
northeast winds over much of the Commonwealth will auger in drier
and slightly cooler air. Dewpoints will fall to near 50 across
northern Kentucky Friday. Friday will see the coolest temperatures
of the entire upcoming week with highs ranging from near 80 south to
as cool as the mid 70s across the northern Bluegrass. Expect mostly
clear skies Friday and Saturday with two refreshingly cool nights.
By early Sunday, the closed low over the desert southwest will
slowly move towards the Texas Panhandle. Strong 500mb ridging will
begin to build over the Lower Ohio Valley. By mid-week, strong
ridging will form an arc around the remnants of this closed low,
which is forecast to become nearly cutoff by both the GFS and the
ECMWF.
In a nutshell, a very summer-like regime will set up beginning
Sunday for a large portion of the Lower Ohio and Mississippi
Valleys. Humidities and dewpoints will increase a bit by Sunday and
especially by Monday, back towards the lower to mid 60s. However,
believe the latter half of the weekend will stay dry as any
convection will be inhibited by poor lapse rates and overhead 500mb
ridging. Highs Sunday and Monday will rise from the mid 80s Sunday
to a possibility of summer`s first 90 degree reading on Monday.
A typical summer-like pattern will continue Tuesday and for probably
much of the next workweek. Warm and humid conditions expected
Tuesday with a chance of afternoon and evening thunderstorms and
highs in the mid to upper 80s.
&&
.AVIATION (12Z TAF Update)...
Issued at 635 AM EDT Wed May 21 2014
Low pressure to our northwest is firing off storms across northern
IL/IN this hour. This low will drag a cold front toward the region
this afternoon. Latest HRRR and local WRF now going along with early
forecast reasoning of a line of storms forming over central Indiana
mid afternoon and pushing into the KSDF/KLEX terminals at some point
late in the afternoon or evening. Continue to have a PROB30 group
for both sites for stronger winds gusts and IFR conditions.
Continued development overnight is more in question, but the
presence of the front across the region late along with residual
moisture may allow for further storms late. Have slightly higher
confidence in this solution over KLEX, so have VCTS for them through
the night. Outside of storms today, winds will gust from the
southwest later this morning and afternoon, with peak gusts of 20-25
knots.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Short Term........RJS
Long Term.........JSD
Aviation..........RJS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1106 AM EDT WED MAY 21 2014
.UPDATE...
A REGION OF MID LEVEL SUBSIDENCE IN THE WAKE OF THE EARLY MORNING
THUNDERSTORM COMPLEXES HAS ESSENTIALLY SHUT DOWN CONVECTION THIS
MORNING. A LINGERING RESERVOIR OF LOW LEVEL MOISTURE OVER SOUTHERN
MICHIGAN HAS BEEN ALLOWING THE RAPID DEVELOPMENT OF STRATO CU AS
DIURNAL HEATING HAS KICKED IN. COVERAGE AND INTENSITY OF
AFTERNOON/EVENING THUNDERSTORMS WILL BE PREDICATED UPON HOW WELL
DIURNAL MIXING ERODES SOME OF THESE LOW CLOUDS AND WEAKENS A MID
LEVEL CAP. THE 14Z SURFACE ANALYSIS SHOWS AN ELONGATED REGION OF
LOW PRESSURE OVER SRN LOWER MI WITH AN ENHANCED REGION OF
CONVERGENCE ALONG A SFC TROUGH OVER THE WRN LAKE MI SHORELINE. THE
12Z NAM/RAP/HRR ALL SHOW THIS BOUNDARY ADVANCING INTO SE MI THIS
AFTERNOON...WHILE A MORE E-W ORIENTED BOUNDARY NOTED JUST SOUTH OF
THE I-69 CORRIDOR REMAINS NEARLY STATIONARY. THE LOW LEVEL WIND
FIELD MAY ALSO REMAIN WEAK ENOUGH TO ALLOW SOME LAKE BREEZE
DEVELOPMENT ALONG THE LAKES HURON/ST CLAIR/ERIE SHORELINES. THESE
BOUNDARIES WILL BE THE MAIN FOCUS FOR CONVECTIVE INITIATION LATER
TODAY. 12Z UPSTREAM RAOBS DO SUPPORT MODEL SOLUTIONS IN SHOWING A
WEDGE OF MID LEVEL DRY ACROSS THE UPPER MIDWEST. THIS OTHER REGION
OF MID LEVEL SUBSIDENCE AND PUSH OF DRY AIR IS EXPECTED TO ADVANCE
INTO SE MI BETWEEN 21Z AND 00Z. THE CONCERN IS WHETHER THERE WILL
BE ENOUGH INSTABILITY TO OVERCOME THE CAP PRIOR TO THE ARRIVAL OF
THIS REGION OF SUBSIDENCE.
SFC DEWPOINTS HAVE BEEN RISING WITH THE ONSET OF DAYTIME
HEATING...A SIGN OF RESPECTABLE LOW LEVEL MOISTURE DEPTH. THUS
MODEL SOUNDINGS AND THE MODIFIED 12Z DTX SOUNDING SUGGESTIVE OF
0-1KM ML CAPE OF 1500-2K J/KG SEEM REASONABLE IF SFC TEMPS CAN
PUSH 80 DEG THIS AFTERNOON. 0-6KM BULK SHEAR UP TO 40 KNOTS AND MID
LEVEL DRY AIR ADVECTION RAISES CONCERNS FOR SEVERE STORM POTENTIAL
LATER TODAY. THE SHEAR/INSTABILITY COMBINATION WILL BE FAVORABLE TO
BOTH SUPERCELLS AND LINEAR MODES OF CONVECTION...WITH DAMAGING
WIND GUSTS AND LARGE HAIL A CONCERN. SINCE THE COVERAGE AND
SEVERITY OF CONVECTION WILL RELY ON THE DEGREE OF AFTERNOON
DESTABILIZATION AND MID LEVEL CAP STRENGTH...AN 18Z DTX SOUNDING
WILL BE DONE TODAY.
&&
.AVIATION...ISSUED 715 AM EDT WED MAY 21 2014
//DISCUSSION...
EXPECT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TRAILING THE
PRIMARY STORM CLUSTER OUT OF SE MICHIGAN DURING THE MORNING. MVFR
VISIBILITY WILL ALSO BE POSSIBLE DUE TO FOG THROUGH MID MORNING...
ESPECIALLY WHERE IT HAS RAINED AND WITHIN THE FRONTAL ZONE STRETCHED
WEST TO EAST IN THE FNT/PTK AREA. BOUNDARY LAYER TEMPERATURE
RECOVERY WILL THEN HELP IMPROVE CONDITIONS BY LATE MORNING OR EARLY
AFTERNOON AT THE LATEST. ATTENTION THEN TURNS TO THUNDERSTORM
CHANCES FOR THE MID TO LATE AFTERNOON WHICH WILL DEPEND ON THE
TIMING OF SURFACE HEATING AND THE EVENTUAL SHAPE THE SURFACE FRONT
TO FOCUS LOW LEVEL CONVERGENCE. AT THIS POINT...THE BEST ESTIMATE OF
INITIATION IS EAST OF FNT AND PTK BUT OVER THE DTW AREA MID TO LATE
AFTERNOON. THE COLD FRONT ASSOCIATED WITH THE LOW PRESSURE SYSTEM
OVER THE NORTHERN GREAT LAKES WILL THEN SCOUR ACTIVITY OUT OF THE
REGION BY MIDNIGHT. MVFR CEILING OVER MINNESOTA WILL BE MONITORED
FOR POTENTIAL TO SPREAD OVER LOWER MICHIGAN AFTER MIDNIGHT AND LAST
THROUGH SUNRISE THURSDAY...BUT LOW END VFR STRATOCU LOOKS LIKE A
GOOD BET AS THE COOLER AIR SPREAD OVER THE REGION TOWARD SUNRISE
THURSDAY.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE FOR THUNDERSTORMS LATE AFTERNOON.
* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET TODAY AND THEN TOWARD
SUNRISE THURSDAY.
&&
.PREV DISCUSSION...ISSUED 343 AM EDT WED MAY 21 2014
SHORT TERM... TODAY AND TONIGHT
SURFACE AND MODEL ANALYSIS FIELDS PROVIDE A STRAIGHTFORWARD
DIAGNOSIS FOR ONGOING CONVECTIVE FORCING BUT THAT STILL LEAVES A
CHALLENGING FORECAST FOR WHAT MAY FOLLOW LATER TODAY THROUGH THIS
EVENING UNTIL THE SURFACE COLD FRONT PUSHES THROUGH THE REGION
CLOSER TO MIDNIGHT.
THE LARGE SCALE PATTERN IS ANCHORED BY A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WHICH HAS AN OCCLUDED FRONT EXTENDING INTO
A BROADER SURFACE WAVE OVER LOWER MICHIGAN RIPPLING ALONG THE MAIN
WARM/STATIONARY FRONT EXTENDING INTO OUR AREA. THE LOW LEVEL
MOISTURE AXIS IS ALIGNED ALONG THIS SURFACE PRESSURE FEATURE WITH
BACKGROUND VERTICAL MOTION SUPPLIED BY AGEOSTROPHIC CIRCULATION
UNDER THE SOUTH FLANK OF THE UPPER JET. THE RESULT IS CONTINUED
SUPPORT FOR ONGOING CONVECTION AND DEVELOPMENT OF ADDITIONAL SHOWERS
AND WEAKER STORMS NORTH OF THE SURFACE BOUNDARY. SINCE MIDNIGHT...
CONCERN HAS TRANSITIONED FROM SEVERE WEATHER POTENTIAL NEAR THE OHIO
BORDER TO EXCESSIVE RAINFALL THROUGH THE I-69 CORRIDOR...ALTHOUGH
INTENSITY OF STORMS WILL REMAIN STRONG NEAR THE OHIO BORDER WHERE
MID LEVEL LAPSE RATES ARE GREATEST. AT THE SAME TIME...EXPECT
COVERAGE OF SHOWERS AND STORMS WILL BE NUMEROUS FARTHER NORTH WITHIN
THE FRONTAL CIRCULATION IN THE 850-700 MB LAYER. BASED ON MODEL MEAN
RH TRENDS...THERE IS GOOD AGREEMENT THAT THIS CLUSTER OF CONVECTION
WILL MOVE EAST OF THE AREA AROUND NOON.
OTHER THAN A SLOW PROGRESSION OF THE SURFACE PRESSURE PATTERN...
THERE WILL NOT BE MUCH DIFFERENCE IN THE LARGE SCALE FEATURES
AFFECTING THE AREA DURING THE AFTERNOON COMPARED TO THE CURRENT
SETUP. THE CONSENSUS OF MODEL MSL PRESSURE SOLUTIONS PLACES THE
TRIPLE POINT OF THE OCCLUSION OVER NORTHERN LOWER MICHIGAN AROUND
18Z. SOUTHWEST FLOW RETURNING BEHIND THE MORNING CONVECTIVE PATTERN
WILL BE ADEQUATE TO MAINTAIN THUNDERSTORM POTENTIAL WITH SUFFICIENT
RECOVERY OF INSTABILITY. THE TIMING AND MAGNITUDE OF RECOVERY IS THE
MAIN UNCERTAINTY IN THE FORECAST AND SEVERE WEATHER POTENTIAL.
REASONABLE DOWNWARD ADJUSTMENTS TO THE LATEST NAM AND RAP OUTPUT
STILL OFFERS 0-1KM MLCAPE RECOVERING TO ABOUT 1500 J/KG MID TO LATE
AFTERNOON...BUT WITH MODEST MID LEVEL LAPSE RATES OF 6-7C/KM IN THE
700-500 MB LAYER AS THE EML SUPPORTING THE EARLY MORNING STORMS IS
DIRECTED INTO THE UPPER OHIO VALLEY. REMAINING IN PLACE WILL BE THE
SOUTHERN FRINGES OF DYNAMIC SUPPORT FROM THE UPPER WAVE OVER
NORTHERN ONTARIO...AND STRONG WESTERLY FLOW ALOFT OVER LOWER
MICHIGAN. MODEL SOUNDINGS INDICATE A SOLID STRAIGHT-LINE HODOGRAPH
ANCHORED BY 50-60 KNOTS OF FLOW AROUND 500 MB AND 0-6 KM BULK SHEAR
AROUND 50 KNOTS. DIFFERENT FROM YESTERDAY WILL BE A MORE VEERED LOW
LEVEL FLOW WHICH IS LESS FAVORABLE FOR TORNADOGENESIS...BUT THE
OVERALL PROFILE IS STILL SUPPORTIVE OF STORM SPLITS/SUPERCELL
ORGANIZATION EARLY IN THE CONVECTIVE CYCLE. PLAN TO CALL FOR
ISOLATED STORMS APPROACHING SEVERE LIMITS UNTIL SEVERE POTENTIAL CAN
BE REFINED WITH OBSERVATIONS AS THE DAY PROGRESSES. SHOWERS AND
WEAKER STORMS SHOULD OTHERWISE BECOME NUMEROUS BY LATER AFTERNOON
THROUGH THE EVENING BEFORE THE COLD FRONT SWEEPS EVERYTHING OUT OF
THE REGION AROUND MIDNIGHT.
LONG TERM...
COLD ADVECTION PATTERN EMBEDDED WITHIN CORRIDOR OF CYCLONIC
NORTHWEST FLOW ALOFT WILL PERSIST INTO FRIDAY MORNING. H85
TEMPERATURES ARE PROGGED TO FALL FROM 10C LATE TONIGHT TO 4C FRIDAY
MORNING. ONGOING COLD ADVECTION WILL ENSURE STEEP LOW-LEVEL LAPSE
RATES CAPABLE OF SUPPORTING EXPANSIVE AFTERNOON STRATOCU,
PARTICULARLY IN THE PRESENCE OF LOW AMPLITUDE DISTURBANCES RIPPLING
ALONG IN THE FLOW ALOFT. INFLUX OF THE COOLER AIRMASS COMBINED WITH
CLOUDS DEVELOPING DURING PEAK HEATING WILL LIMIT HIGHS TO THE
MID/UPPER 60S ON BOTH FRIDAY AND SATURDAY. HIGH AMPLITUDE RIDGE WILL
VERY GRADUALLY MIGRATE OVER THE GREAT LAKES THROUGH THE HOLIDAY
WEEKEND AS THE PATTERN SLOWS IN RESPONSE TO THE CLOSED LOW OVER THE
SOUTHWEST UNITED STATES. REBOUNDING THERMAL PROFILES WILL BE
ACCOMPANIED BY DEEP LAYER SUBSIDENCE, ADDING CONFIDENCE TO THE
FORECAST FOR A WARM AND MOSTLY SUNNY HOLIDAY WEEKEND. TEMPERATURES
WILL MODERATE FROM LOW/MID 70S ON SATURDAY TO THE LOW 80S BY MONDAY.
MARINE...
A WEAK COLD FRONT WILL SWING THROUGH THE CENTRAL GREAT LAKES THIS
AFTERNOON. BRISK NORTHWEST WINDS WILL THEN BUILD IN FOR TONIGHT AND
THURSDAY. ANY THUNDERSTORMS WHICH DEVELOP TONIGHT THROUGH TOMORROW
MAY BE STRONG TO SEVERE. LIGHT WINDS WILL RETURN FOR THE WEEKEND AS
HIGH PRESSURE SETTLES OVER THE AREA.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......SC
AVIATION.....BT
SHORT TERM...BT
LONG TERM....JVC
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
715 AM EDT WED MAY 21 2014
.AVIATION...
//DISCUSSION...
EXPECT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TRAILING THE
PRIMARY STORM CLUSTER OUT OF SE MICHIGAN DURING THE MORNING. MVFR
VISIBILITY WILL ALSO BE POSSIBLE DUE TO FOG THROUGH MID MORNING...
ESPECIALLY WHERE IT HAS RAINED AND WITHIN THE FRONTAL ZONE STRETCHED
WEST TO EAST IN THE FNT/PTK AREA. BOUNDARY LAYER TEMPERATURE
RECOVERY WILL THEN HELP IMPROVE CONDITIONS BY LATE MORNING OR EARLY
AFTERNOON AT THE LATEST. ATTENTION THEN TURNS TO THUNDERSTORM
CHANCES FOR THE MID TO LATE AFTERNOON WHICH WILL DEPEND ON THE
TIMING OF SURFACE HEATING AND THE EVENTUAL SHAPE THE SURFACE FRONT
TO FOCUS LOW LEVEL CONVERGENCE. AT THIS POINT...THE BEST ESTIMATE OF
INITIATION IS EAST OF FNT AND PTK BUT OVER THE DTW AREA MID TO LATE
AFTERNOON. THE COLD FRONT ASSOCIATED WITH THE LOW PRESSURE SYSTEM
OVER THE NORTHERN GREAT LAKES WILL THEN SCOUR ACTIVITY OUT OF THE
REGION BY MIDNIGHT. MVFR CEILING OVER MINNESOTA WILL BE MONITORED
FOR POTENTIAL TO SPREAD OVER LOWER MICHIGAN AFTER MIDNIGHT AND LAST
THROUGH SUNRISE THURSDAY...BUT LOW END VFR STRATOCU LOOKS LIKE A
GOOD BET AS THE COOLER AIR SPREAD OVER THE REGION TOWARD SUNRISE
THURSDAY.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE FOR THUNDERSTORMS LATE AFTERNOON.
* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET TODAY AND THEN TOWARD
SUNRISE THURSDAY.
&&
.PREV DISCUSSION...ISSUED 343 AM EDT WED MAY 21 2014
SHORT TERM... TODAY AND TONIGHT
SURFACE AND MODEL ANALYSIS FIELDS PROVIDE A STRAIGHTFORWARD
DIAGNOSIS FOR ONGOING CONVECTIVE FORCING BUT THAT STILL LEAVES A
CHALLENGING FORECAST FOR WHAT MAY FOLLOW LATER TODAY THROUGH THIS
EVENING UNTIL THE SURFACE COLD FRONT PUSHES THROUGH THE REGION
CLOSER TO MIDNIGHT.
THE LARGE SCALE PATTERN IS ANCHORED BY A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WHICH HAS AN OCCLUDED FRONT EXTENDING INTO
A BROADER SURFACE WAVE OVER LOWER MICHIGAN RIPPLING ALONG THE MAIN
WARM/STATIONARY FRONT EXTENDING INTO OUR AREA. THE LOW LEVEL
MOISTURE AXIS IS ALIGNED ALONG THIS SURFACE PRESSURE FEATURE WITH
BACKGROUND VERTICAL MOTION SUPPLIED BY AGEOSTROPHIC CIRCULATION
UNDER THE SOUTH FLANK OF THE UPPER JET. THE RESULT IS CONTINUED
SUPPORT FOR ONGOING CONVECTION AND DEVELOPMENT OF ADDITIONAL SHOWERS
AND WEAKER STORMS NORTH OF THE SURFACE BOUNDARY. SINCE MIDNIGHT...
CONCERN HAS TRANSITIONED FROM SEVERE WEATHER POTENTIAL NEAR THE OHIO
BORDER TO EXCESSIVE RAINFALL THROUGH THE I-69 CORRIDOR...ALTHOUGH
INTENSITY OF STORMS WILL REMAIN STRONG NEAR THE OHIO BORDER WHERE
MID LEVEL LAPSE RATES ARE GREATEST. AT THE SAME TIME...EXPECT
COVERAGE OF SHOWERS AND STORMS WILL BE NUMEROUS FARTHER NORTH WITHIN
THE FRONTAL CIRCULATION IN THE 850-700 MB LAYER. BASED ON MODEL MEAN
RH TRENDS...THERE IS GOOD AGREEMENT THAT THIS CLUSTER OF CONVECTION
WILL MOVE EAST OF THE AREA AROUND NOON.
OTHER THAN A SLOW PROGRESSION OF THE SURFACE PRESSURE PATTERN...
THERE WILL NOT BE MUCH DIFFERENCE IN THE LARGE SCALE FEATURES
AFFECTING THE AREA DURING THE AFTERNOON COMPARED TO THE CURRENT
SETUP. THE CONSENSUS OF MODEL MSL PRESSURE SOLUTIONS PLACES THE
TRIPLE POINT OF THE OCCLUSION OVER NORTHERN LOWER MICHIGAN AROUND
18Z. SOUTHWEST FLOW RETURNING BEHIND THE MORNING CONVECTIVE PATTERN
WILL BE ADEQUATE TO MAINTAIN THUNDERSTORM POTENTIAL WITH SUFFICIENT
RECOVERY OF INSTABILITY. THE TIMING AND MAGNITUDE OF RECOVERY IS THE
MAIN UNCERTAINTY IN THE FORECAST AND SEVERE WEATHER POTENTIAL.
REASONABLE DOWNWARD ADJUSTMENTS TO THE LATEST NAM AND RAP OUTPUT
STILL OFFERS 0-1KM MLCAPE RECOVERING TO ABOUT 1500 J/KG MID TO LATE
AFTERNOON...BUT WITH MODEST MID LEVEL LAPSE RATES OF 6-7C/KM IN THE
700-500 MB LAYER AS THE EML SUPPORTING THE EARLY MORNING STORMS IS
DIRECTED INTO THE UPPER OHIO VALLEY. REMAINING IN PLACE WILL BE THE
SOUTHERN FRINGES OF DYNAMIC SUPPORT FROM THE UPPER WAVE OVER
NORTHERN ONTARIO...AND STRONG WESTERLY FLOW ALOFT OVER LOWER
MICHIGAN. MODEL SOUNDINGS INDICATE A SOLID STRAIGHT-LINE HODOGRAPH
ANCHORED BY 50-60 KNOTS OF FLOW AROUND 500 MB AND 0-6 KM BULK SHEAR
AROUND 50 KNOTS. DIFFERENT FROM YESTERDAY WILL BE A MORE VEERED LOW
LEVEL FLOW WHICH IS LESS FAVORABLE FOR TORNADOGENESIS...BUT THE
OVERALL PROFILE IS STILL SUPPORTIVE OF STORM SPLITS/SUPERCELL
ORGANIZATION EARLY IN THE CONVECTIVE CYCLE. PLAN TO CALL FOR
ISOLATED STORMS APPROACHING SEVERE LIMITS UNTIL SEVERE POTENTIAL CAN
BE REFINED WITH OBSERVATIONS AS THE DAY PROGRESSES. SHOWERS AND
WEAKER STORMS SHOULD OTHERWISE BECOME NUMEROUS BY LATER AFTERNOON
THROUGH THE EVENING BEFORE THE COLD FRONT SWEEPS EVERYTHING OUT OF
THE REGION AROUND MIDNIGHT.
LONG TERM...
COLD ADVECTION PATTERN EMBEDDED WITHIN CORRIDOR OF CYCLONIC
NORTHWEST FLOW ALOFT WILL PERSIST INTO FRIDAY MORNING. H85
TEMPERATURES ARE PROGGED TO FALL FROM 10C LATE TONIGHT TO 4C FRIDAY
MORNING. ONGOING COLD ADVECTION WILL ENSURE STEEP LOW-LEVEL LAPSE
RATES CAPABLE OF SUPPORTING EXPANSIVE AFTERNOON STRATOCU,
PARTICULARLY IN THE PRESENCE OF LOW AMPLITUDE DISTURBANCES RIPPLING
ALONG IN THE FLOW ALOFT. INFLUX OF THE COOLER AIRMASS COMBINED WITH
CLOUDS DEVELOPING DURING PEAK HEATING WILL LIMIT HIGHS TO THE
MID/UPPER 60S ON BOTH FRIDAY AND SATURDAY. HIGH AMPLITUDE RIDGE WILL
VERY GRADUALLY MIGRATE OVER THE GREAT LAKES THROUGH THE HOLIDAY
WEEKEND AS THE PATTERN SLOWS IN RESPONSE TO THE CLOSED LOW OVER THE
SOUTHWEST UNITED STATES. REBOUNDING THERMAL PROFILES WILL BE
ACCOMPANIED BY DEEP LAYER SUBSIDENCE, ADDING CONFIDENCE TO THE
FORECAST FOR A WARM AND MOSTLY SUNNY HOLIDAY WEEKEND. TEMPERATURES
WILL MODERATE FROM LOW/MID 70S ON SATURDAY TO THE LOW 80S BY MONDAY.
MARINE...
A WEAK COLD FRONT WILL SWING THROUGH THE CENTRAL GREAT LAKES THIS
AFTERNOON. BRISK NORTHWEST WINDS WILL THEN BUILD IN FOR TONIGHT AND
THURSDAY. ANY THUNDERSTORMS WHICH DEVELOP TONIGHT THROUGH TOMORROW
MAY BE STRONG TO SEVERE. LIGHT WINDS WILL RETURN FOR THE WEEKEND AS
HIGH PRESSURE SETTLES OVER THE AREA.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....BT
SHORT TERM...BT
LONG TERM....JVC
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1008 AM CDT WED MAY 21 2014
.UPDATE...ANOTHER DRY AND WARM DAY IS IN STORE AS HIGH PRESSURE
RIDGING REMAINS IN CONTROL. HIGHS THIS AFTERNOON ARE EXPECTED TO
REACH THE UPPER 80S FOR MOST LOCATIONS. THE CURRENT FORECAST IS IN
GOOD SHAPE WITH NO CHANGES NEEDED. /27/
&&
.AVIATION...ALL TAF SITES EXPECT KGLH HAVE MIXED OUT THIS MORNING.
EXPECT THAT TO OCCUR AROUND 16Z LEAVING ALL SITES IN VFR CONDITIONS
THROUGH MOST OF THE FORECAST PERIOD. WILL HAVE TO WATCH FOR
STRATUS/FOG DEVELOPMENT AGAIN TOWARD 12Z THURSDAY. /SW/
&&
.PREV DISCUSSION... /ISSUED 331 AM CDT WED MAY 21 2014/
SHORT TERM...TODAY THROUGH THURSDAY NIGHT...SPRAWLING MID/UPPER
LEVEL ANTICYCLONE...CENTERED OVER THE LOWER MS VALLEY...CONTINUES TO
PROVIDE TRANQUIL WEATHER OVER THE FORECAST AREA AND THIS LOOKS TO
CONTINUE THROUGH THE SHORT TERM. AT THE SURFACE...RIDGE AXIS REMAINS
POSITIONED ALONG THE NORTHERN GULF COAST. LOW LEVEL FLOW ABOUT THIS
AXIS CONTINUES TO PROVIDE AN OPPORTUNITY FOR STRATUS/FOG DEVELOPMENT
THROUGH ISENTROPIC ASCENT AGAIN THIS MORNING AND TO SOME EXTENT
THURSDAY MORNING AS WELL.
THIS ISENTROPIC ASCENT CAN BE BEST SEEN IN THE 290-295K THETA LAYER
WITH BEST ZONE OF PRESSURE ADVECTION COUPLED WITH RISING THETA
SURFACES ALONG AND SOUTH OF HIGHWAY 84. ALREADY STRATUS STREAMERS
HAVE DEV LOPED FROM KMCB-K1R7. HRRR AND SREF DATA INDICATING
STRATUS/FOG AREA WILL CONTINUE TO FILL IN THIS MORNING OVER SOUTHERN
PORTIONS OF THE AREA...BUT...LIKE YESTERDAY MORNING...DISSIPATE
RAPIDLY WITHIN A COUPLE HOURS AFTER SUNRISE.
HIGH PRESSURE CENTER LOOKS TO BECOME SITUATED OVER SOUTH MS TONIGHT.
THIS WILL SERVE TO CHANGE OUR LOW LEVEL WINDS TO A MORE SOUTHWESTERLY
DIRECTION AND LESS FAVORABLE FOR STRATUS DEVELOPMENT BOTH THURSDAY
AND FRIDAY MORNINGS. ONLY THE EXTREME SW SECTION OF THE FORECAST AREA
WILL MAINTAIN ENOUGH OF A SOUTHERLY WIND COMPONENT TO SEE SOME
STRATUS THURSDAY MORNING.
LOOKING AT THE GFS MOS ENSEMBLE...STANDARD DEVIATIONS NEAR ZERO ARE
NOT OFFERING MUCH OF AN OPPORTUNITY TO IMPROVE ON THE TEMPERATURE
FORECAST. AS THE SURFACE HIGH BECOMES CENTERED OVER SOUTH
MS...SIGNIFICANT LOW LEVEL MOISTURE RETURN WILL DIMINISH ALLOWING
FOR CONTINUED LARGE DIURNAL RANGES AND MAX TEMPS TO BEGIN INCHING UP
A LITTLE EACH DAY AS MOS IS INDICATING./26/
LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY...WARM AND DRY FOR THE
MEMORIAL DAY WEEKEND WITH SLIGHTLY ABOVE NORMAL TEMPERATURES BY ~5F
DEGREES. RAIN CHANCES WILL INCREASE EACH DAY STARTING NEXT MONDAY
INTO MID WEEK AS A MID-LEVEL DISTURBANCE SLOWLY APPROACHES THE
REGION.
OVERALL CONUS PATTERN LATE WEEK INTO THE HOLIDAY WEEKEND WILL
FEATURE A MID/UPPER LEVEL TROUGH BEGINNING TO CUT-OFF OVER THE
DESERT SW AS RIDGING CONTINUES OVER THE SE WITH A SHARP S/WV TROUGH
PIVOTING ACROSS GREAT LAKES INTO THE MID ATLANTIC. THE MID ATLANTIC
TROUGH WILL ACT TO BRING A NW/SE ORIENTED WEAK DENSITY/CONVERGENCE
BOUNDARY ACROSS N/NE MS INTO AL OVER THE WEEKEND. DESPITE THIS
LOW-LVL FOCUS AND SOME HINT OF EMBEDDED IMPULSES WITHIN THE BACKSIDE
NW FLOW...PWATS OF 1.2-1.3"...HIGH LCL INVERTED "V" SOUNDINGS...AND
MASS FIELDS SUGGESTIVE OF LIMITED CONVECTION IF ANY...HAVE KEPT WEATHER
WORDING OUT OF GRIDS THIS PACKAGE. A ROGUE SHOWER CAN NOT BE
COMPLETELY RULED OUT FOR THE NE CORNER THOUGH AND WILL MONITOR
TRENDS.
FOR MON-WED NEXT WEEK...OPS GFS AND EC ARE IN DECENT AGREEMENT WITH
CUT-OFF LOW SLOWLY PROGRESSING EAST ACROSS THE PLAINS TOWARDS THE
MID TO LOWER MS VALLEY BY MID WEEK. AS THIS FEATURE APPROACHES...
RAIN/TSTORM CHANCES WILL INCREASE WITH SOME LINGERING ACTIVITY DURING
THE OVERNIGHT HOURS TUES INTO WED WITH GREATER COVERAGE WED AFTN.
FOR WEATHER ELEMENTS...MEX LOWS WERE RAISED 1-4F NEXT WEEK TO ALIGN TOWARDS
RAW EC/GFS DEWPOINTS. MEX POPS WERE BUMPED UP SLIGHTLY TUES-WED. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 89 63 90 63 / 0 0 0 0
MERIDIAN 89 60 90 60 / 0 0 0 0
VICKSBURG 87 61 88 59 / 0 0 0 0
HATTIESBURG 88 62 90 62 / 0 0 0 0
NATCHEZ 87 62 86 63 / 0 0 0 0
GREENVILLE 88 65 89 65 / 0 0 2 2
GREENWOOD 88 63 89 62 / 0 0 2 2
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1007 AM CDT WED MAY 21 2014
.UPDATE...
ISSUED AT 1004 AM CDT WED MAY 21 2014
MAIN FCST ISSUE IS TEMPS/CLOUD COVER. CYCLONIC FLOW AROUND SFC LOW
NEAR THUNDER BAY ONTARIO ALONG WITH COLD ADVECTION WILL KEEP
WRAPAROUND CLOUD COVER WELL INTO THE AFTN OVER NW MN. SOME HOLES
WILL OCCUR HOWEVER AS SUN IS ABOVE THE CLOUD LAYER AND SOME THIN
BREAKS ALREADY. BUT OVERALL INCREASED CLOUD COVER THRU THE AFTN
AND LOWERED TEMPS A FEW DEGREES IN NE MN. FOR THE RRV AND ERN ND
EXPECT MORE SUN AS THE DAY PROGRESSES AND WITH THAT DIDNT TINKER
MUCH WITH TEMPS YET.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
CLOUDS AND TEMPERATURES WILL BE THE MAIN ISSUE FOR THE PERIOD.
WEST TO NORTHWESTERLY FLOW ALOFT WILL CONTINUE AS THE UPPER TROUGH
FROM YESTERDAY PULLS OFF TO THE EAST. THERE HAS BEEN PLENTY OF
CLOUDS BEHIND THE COLD FRONT THAT MOVED THROUGH...WITH THE ENTIRE
CWA SEEING MOSTLY CLOUDY SKIES THIS MORNING. RUC13 925-850MB RH WHICH
HAS A GOOD HANDLE ON CLOUDS DOES NOT REALLY SEE MUCH DECREASE
UNTIL THE MIDDLE OF THE DAY. THINK THAT CLOUDS WILL CONTINUE FOR
AT LEAST PART OF THE MORNING BEFORE HIGH PRESSURE MOVES IN THIS
AFTERNOON. THINK THAT THERE SHOULD BE SOME SUN LATE IN THE DAY AND
TEMPS WILL STILL GET INTO THE 60S.
TONIGHT...WE SHOULD CONTINUE TO SEE DECREASING CLOUDS AND WINDS
WILL BECOME LIGHT AS THE CENTER OF THE HIGH SETTLES OVER THE AREA.
DEW POINTS WILL DROP DOWN TO NEAR 40 DEGREES AND LOWS WILL BE
MAINLY IN THE LOW TO MID 40S ACROSS THE AREA. WILL HAVE TO WATCH
FOR SOME PATCHY FOG FORMATION BUT NOT CONFIDENT ENOUGH TO INCLUDE
IN THE GRIDS AT THIS POINT. THE UPPER RIDGE WILL CONTINUE TO BUILD
INTO THE PLAINS ON THURSDAY. LIGHT SOUTHEAST WINDS AND SOME SUN
WILL HELP TEMPS GET TO NEAR 70 DEGREES.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE UPPER RIDGE CONTINUES TO
BUILD INTO CANADA...AND MODELS SHOW SOME INDICATION OF SOME FAIRLY
WEAK WAVES RIDING ALONG THE BACK SIDE OF THE RIDGE. THERE COULD BE
SOME CONVECTIVE ACTIVITY WITH THESE WAVES...ALTHOUGH MODELS HAVE
MOST OF PRECIP TO OUR WEST AT THIS POINT. GIVEN THE UPPER LEVEL
FLOW SOME CONVECTION CLIPPING OUR NORTHWESTERN COUNTIES WILL BE
POSSIBLE...SO INCLUDED SOME LOW POPS THURSDAY NIGHT AND FRIDAY.
ACTIVITY WILL BE FURTHER EAST FRIDAY NIGHT AS THE RIDGE AXIS
SHIFTS A BIT EASTWARD AND MOISTURE TRANSPORT KICKS IN. INCLUDED
POPS BEYOND THE DEVILS LAKE AREA BUT KEPT THEM PRETTY LOW FOR NOW.
TEMPS THROUGH THE END OF THE WORK WEEK WILL BE WARMING UP TO ABOVE
NORMAL VALUES WITH HIGHS IN THE MID TO UPPER 70S.
FOR SATURDAY INTO SUNDAY...UPPER LEVEL RIDGE AXIS HAS SHIFTED OVER
THE AREA...WITH WARMER TEMPERATURES EXPECTED INTO THE MID TO UPPER
70S. A SERIES OF DISTURBANCES LOOK TO RIDE OVER THE RIDGE AXIS
DECREASING STABILITY AND ALLOWING FOR BETTER CHANCES FOR SHOWERS AND
TSTMS. OTHERWISE...FOR MONDAY AND TUESDAY...LOOK FOR CONTINUED WARM
TEMPS WITH SHOWERS DECREASING AS SFC HIGH PRESSURE SETTLES ACROSS
THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 643 AM CDT WED MAY 21 2014
CONDITIONS HAVE BEEN VARYING BETWEEN MVFR AND IFR...ALTHOUGH A FEW
SPOTS HAVE LIFTED TO 3500 FT IN THE NORTHERN FORECAST AREA. CIGS
WILL CONTINUE TO SLOWLY LIFT...MOVING UP INTO THE MVFR TO VFR
RANGE LATER THIS MORNING...THEN EVENTUALLY CLEARING OUT. FIRST TO
CLEAR OUT WILL BE KDVL WHILE KBJI WILL HANG ONTO CLOUDS UNTIL LATE
AFTERNOON. NORTHWEST WINDS AT 10 TO 15 KTS WILL BECOME LIGHT AND
VARIABLE AFTER SUNSET.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
643 AM CDT WED MAY 21 2014
.UPDATE...
ISSUED AT 643 AM CDT WED MAY 21 2014
MADE SOME MINOR TWEAKS TO CLOUD COVER...THINK WE SHOULD SLOWLY SEE
SOME ERODING THROUGHOUT THE DAY ALTHOUGH THE FAR EASTERN TIER MAY
SEE CLOUDS HANG ON A BIT LONGER. NO OTHER MAJOR CHANGES.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
CLOUDS AND TEMPERATURES WILL BE THE MAIN ISSUE FOR THE PERIOD.
WEST TO NORTHWESTERLY FLOW ALOFT WILL CONTINUE AS THE UPPER TROUGH
FROM YESTERDAY PULLS OFF TO THE EAST. THERE HAS BEEN PLENTY OF
CLOUDS BEHIND THE COLD FRONT THAT MOVED THROUGH...WITH THE ENTIRE
CWA SEEING MOSTLY CLOUDY SKIES THIS MORNING. RUC13 925-850MB RH WHICH
HAS A GOOD HANDLE ON CLOUDS DOES NOT REALLY SEE MUCH DECREASE
UNTIL THE MIDDLE OF THE DAY. THINK THAT CLOUDS WILL CONTINUE FOR
AT LEAST PART OF THE MORNING BEFORE HIGH PRESSURE MOVES IN THIS
AFTERNOON. THINK THAT THERE SHOULD BE SOME SUN LATE IN THE DAY AND
TEMPS WILL STILL GET INTO THE 60S.
TONIGHT...WE SHOULD CONTINUE TO SEE DECREASING CLOUDS AND WINDS
WILL BECOME LIGHT AS THE CENTER OF THE HIGH SETTLES OVER THE AREA.
DEW POINTS WILL DROP DOWN TO NEAR 40 DEGREES AND LOWS WILL BE
MAINLY IN THE LOW TO MID 40S ACROSS THE AREA. WILL HAVE TO WATCH
FOR SOME PATCHY FOG FORMATION BUT NOT CONFIDENT ENOUGH TO INCLUDE
IN THE GRIDS AT THIS POINT. THE UPPER RIDGE WILL CONTINUE TO BUILD
INTO THE PLAINS ON THURSDAY. LIGHT SOUTHEAST WINDS AND SOME SUN
WILL HELP TEMPS GET TO NEAR 70 DEGREES.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE UPPER RIDGE CONTINUES TO
BUILD INTO CANADA...AND MODELS SHOW SOME INDICATION OF SOME FAIRLY
WEAK WAVES RIDING ALONG THE BACK SIDE OF THE RIDGE. THERE COULD BE
SOME CONVECTIVE ACTIVITY WITH THESE WAVES...ALTHOUGH MODELS HAVE
MOST OF PRECIP TO OUR WEST AT THIS POINT. GIVEN THE UPPER LEVEL
FLOW SOME CONVECTION CLIPPING OUR NORTHWESTERN COUNTIES WILL BE
POSSIBLE...SO INCLUDED SOME LOW POPS THURSDAY NIGHT AND FRIDAY.
ACTIVITY WILL BE FURTHER EAST FRIDAY NIGHT AS THE RIDGE AXIS
SHIFTS A BIT EASTWARD AND MOISTURE TRANSPORT KICKS IN. INCLUDED
POPS BEYOND THE DEVILS LAKE AREA BUT KEPT THEM PRETTY LOW FOR NOW.
TEMPS THROUGH THE END OF THE WORK WEEK WILL BE WARMING UP TO ABOVE
NORMAL VALUES WITH HIGHS IN THE MID TO UPPER 70S.
FOR SATURDAY INTO SUNDAY...UPPER LEVEL RIDGE AXIS HAS SHIFTED OVER
THE AREA...WITH WARMER TEMPERATURES EXPECTED INTO THE MID TO UPPER
70S. A SERIES OF DISTURBANCES LOOK TO RIDE OVER THE RIDGE AXIS
DECREASING STABILITY AND ALLOWING FOR BETTER CHANCES FOR SHOWERS AND
TSTMS. OTHERWISE...FOR MONDAY AND TUESDAY...LOOK FOR CONTINUED WARM
TEMPS WITH SHOWERS DECREASING AS SFC HIGH PRESSURE SETTLES ACROSS
THE REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 643 AM CDT WED MAY 21 2014
CONDITIONS HAVE BEEN VARYING BETWEEN MVFR AND IFR...ALTHOUGH A FEW
SPOTS HAVE LIFTED TO 3500 FT IN THE NORTHERN FORECAST AREA. CIGS
WILL CONTINUE TO SLOWLY LIFT...MOVING UP INTO THE MVFR TO VFR
RANGE LATER THIS MORNING...THEN EVENTUALLY CLEARING OUT. FIRST TO
CLEAR OUT WILL BE KDVL WHILE KBJI WILL HANG ONTO CLOUDS UNTIL LATE
AFTERNOON. NORTHWEST WINDS AT 10 TO 15 KTS WILL BECOME LIGHT AND
VARIABLE AFTER SUNSET.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...JR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1155 AM EDT WED MAY 21 2014
.SYNOPSIS...
THUNDERSTORMS WILL MOVE ACROSS THE REGION TODAY AHEAD OF A COLD
FRONT. THE COLD FRONT WILL CROSS THE REGION TONIGHT. HIGH PRESSURE
WILL THEN BRING FAIR WEATHER TO OUR AREA FOR THE REMAINDER OF THE
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST FOCUS IN THE NEAR TERM IS THE POTENTIAL FOR SEVERE
WEATHER THIS AFTERNOON INTO THIS EVENING. A 17Z ILN SOUNDING WILL
BE LAUNCHED TO INTERROGATE ATMOSPHERIC CHANGES FROM THIS MORNING
AND ALSO TO AID FOR BETTER ATMOSPHERIC ASSESSMENT FOR LATER THIS
AFTN.
IT LOOKS LIKE THAT PERHAPS THE LATEST HRRR MAY BE LATCHING ON AS
TO WHAT TRANSPIRES LATER THIS AFTERNOON AND EVENING. SCATTERED
CONVECTION ACRS NRN INDIANA INTO NRN/CNTRL OHIO IS WHAT REMAINS
OF NOCTURNAL CONVECTION THAT PUSHED INTO THE REGION WELL AHEAD OF
A COLD FRONT. HRRR AND OTHER MESOSCALE MODELS SUGGEST THAT A
PREFRONTAL CONVERGENCE BOUNDARY...LIKELY AIDED BY CURRENT
CONVECTION...SHOULD ALLOW CONVECTION TO EXPAND IN COVERAGE AND
INTENSITY AS IT SHIFTS SOUTHEAST TOWARD AN INCREASING UNSTABLE
AIRMASS TO THE SOUTH AND SOUTHWEST. DECENT BULK SHEAR WILL EXIST
FOR ORGANIZATION OF STORMS IN EITHER LINE SEGMENTS OR PERHAPS
DISCRETE ROTATORS. MOIST AIR IN THE FORM OF MID/UPPER 60S
DEWPOINTS SHOULD ADVECT INTO THE REGION THIS AFTERNOON. THESE
VALUES COUPLED WITH SFC TEMPS APPROACHING THE LOWER 80S SHOULD
YIELD MLCAPES IN THE 1500-2000 J/KG...WHICH IS MODERATE
INSTABILITY. GIVEN POTENTIAL FOR ROTATORS AND DECENT
INSTABILITY...COUPLED WITH FAVORABLE WET BULB ZERO VALUES IN THE
9-10 FT RANGE...LARGE HAIL IS A CONCERN. ALSO...MID LEVEL DRIER
AIR WILL RESULT IN ENTRAINMENT AND WITH DCAPES PUSHING INTO THE
1500 J/KG...DAMAGING DOWNBURSTS WITH THE HAIL AND/OR PCPN LOADING
WILL ALSO BE A CONCERN. CAN NOT RULE AT AN ISOLATED TORNADO...BUT
IF THIS WERE TO OCCUR...IT WOULD LIKELY BE A RESULT OF CELL
MERGERS AND/OR OUTFLOW BOUNDARIES WITH DEVELOPING CELLS. FORECAST
CALLS FOR LIKELY POPS THIS AFTN WITH THE POPS SHIFTING TOWARD THE
OHIO RIVER BY EVENING. HIGHS WILL RANGE FROM THE UPPER 70S NORTH
TO THE LOWER 80S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
ONGOING CONVECTION THIS EVENING SAGGING SOUTH OF THE OHIO RIVER
WILL CONTINUE A SLOW PROGRESSION SOUTH AHEAD OF THE COLD FRONT.
MODELS ARE INDICATING A DECREASE IN FORWARD PROPAGATION OF THE
FRONTAL SYSTEM SOUTH OF THE OHIO RIVER TONIGHT. THIS COULD POSE
A FLASH FLOOD THREAT IF STORMS BEGIN TO TRAIN ACROSS THE SAME
LOCATIONS LATE THIS EVENING. WILL HOLD OFF ON ANY MENTION OF THIS
IN THE HWO...AS THERE IS A LARGE AMOUNT OF UNCERTAINTY AS TO THIS
SCENARIO TAKING PLACE DUE TO UNCERTAINTIES IN THE EVENTUAL
LOCATION OF THE FRONTAL BOUNDARY AT THIS TIME FRAME.
THE ILN CWA IS EXPECTED TO BE MAINLY RAIN FREE BY DAYBREAK
THURSDAY WITH THE FRONT SHIFTING SOUTH OF OUR AREA. NORTHWESTERLY
FLOW WILL BRING DRIER AIR INTO THE REGION WITH SEASONABLE
TEMPERATURES AND FAIR WEATHER ON THURSDAY.
HIGH PRESSURE WILL SLOWLY BUILD SOUTHEASTWARD INTO OUR AREA FROM
THE MID WEST THROUGH FRIDAY AND FRIDAY NIGHT. SURFACE WINDS WILL
REMAIN NORTHWESTERLY THURSDAY NIGHT THROUGH FRIDAY AND WILL BECOME
LIGHT ON FRIDAY NIGHT AS THE HIGH BECOMES CENTERED ACROSS THE
REGION. EXPECT MOSTLY CLEAR SKIES DURING THE THURSDAY NIGHT
THROUGH FRIDAY NIGHT TIME PERIOD WITH NEAR NORMAL TEMPERATURES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE WILL ALLOW FOR DRY CONDITIONS THROUGH THE WEEKEND.
COOL NORTHERLY FLOW WILL KEEP TEMPERATURES IN THE UPPER 60S TO LOW
70S ON FRIDAY. A RIDGE WILL GRADUALLY WORK INTO THE REGION THROUGH
THE WEEKEND WITH TEMPERATURES WARMING EACH DAY. BY MONDAY HIGH
TEMPERATURES ARE EXPECTED TO BE IN THE 80S ACROSS THE ENTIRE FA.
PRECIPITATION LOOKS TO HOLD OFF UNTIL TUESDAY. THE GFS IS TRYING TO
DEVELOP A FEW THUNDERSTORMS ACROSS NW PORTIONS OF THE FA ON MONDAY
HOWEVER DECIDED TO GO WITH A DRY FORECAST ON MONDAY AT THIS TIME.
ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE DURING THE DAY
ON TUESDAY. ANY THUNDERSTORM ACTIVITY IS EXPECTED TO DISSIPATE
DURING THE EVENING HOURS WITH THE LOSS OF DAYTIME HEATING.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
THUNDERSTORMS ARE CONTINUING TO TRACK EAST SOUTHEASTWARD ALONG A
BOUNDARY STRETCHING FROM NORTHERN ILLINOIS THROUGH NORTHERN INDIANA
INTO NORTHERN OHIO. THESE STORMS ARE BEING MAINTAINED IN PART BY A
20-30 KNOT 925-850 MB LOW LEVEL JET. AS THIS JET BEGINS TO WEAKEN
THROUGH MID MORNING...EXPECT TO SEE A DECREASE IN THUNDERSTORM COVERAGE
AND INTENSITY OFF TO OUR NORTHWEST. HOWEVER...WE WILL DESTABILIZE
FAIRLY QUICKLY THROUGH LATE MORNING AND INTO THIS AFTERNOON. THIS
WILL COMBINE WITH THE BOUNDARY SAGGING DOWN INTO OUR AREA...TO
RESULT IN MORE WIDESPREAD THUNDERSTORM ACTIVITY THIS
AFTERNOON...POSSIBLY LINGERING INTO THIS EVENING AT THE SOUTHERN
TAF SITES. THERE IS QUITE A BIT OF VARIANCE AMONG THE HI-RES AND
LARGER SCALE MODELS IN REGARD TO THE TIMING AND PLACEMENT OF THIS
REDEVELOPMENT. WILL THEREFORE ALLOW FOR A FAIRLY GENERAL VCTS ON
INTO THIS EVENING WITH A SHORTER TIME FRAME TEMPO -TSRA
GROUP...TRYING TO TARGET THE TIMING OF THE BETTER CHANCE OF
THUNDERSTORMS. DRIER AIR WILL FILTER IN FROM THE NORTHWEST LATER
THIS AFTERNOON INTO THIS EVENING...ALLOWING FOR PCPN TO TAPER OFF
NORTHWEST TO SOUTHEAST THROUGH THIS EVENING.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN/LATTO
NEAR TERM...HICKMAN
SHORT TERM...LATTO
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1023 AM EDT WED MAY 21 2014
.DISCUSSION...
12Z OHX SOUNDING AND RUC FORECAST SOUNDINGS INDICATE A STRONG
CAPPING INVERSION THAT WILL SUPPRESS CONVECTIVE DEVELOPMENT THROUGH
MOST OF THE AFTERNOON. THE CAP WILL BE WEAKEST OVER SW VA AND NE
TN...AND STRONGEST IN THE SOUTHERN VALLEY. RADAR CURRENTLY SHOWS
SHOWERS IN MIDDLE TN...BUT SURFACE OBS DO NOT SHOW PRECIP REACHING
THR GROUND...OR AT LEAST IT IS VERY LIGHT. THIS ACTIVITY IS
EXPECTED TO CONTINUE TO WEAKEN AS IT MOVES SE.
WILL MAKE SOME MINOR ADJUSTMENTS TO POP/WX GRIDS TO FOCUS MORE ON
NORTHERN AREAS THIS AFTERNOON. TEMPERATURES LOOK ON TRACK.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
636 AM CDT WED MAY 21 2014
.AVIATION...
RETREATING DRYLINE HAS ALLOWED SURFACE DEWPOINTS TO INCREASE FROM 16
TO 51 DEGREES FAHRENHEIT SINCE 11 PM. SOUTHWEST LOW-LEVEL WINDS AS
SAMPLED BY KAMA VAD WINDS ARE MOIST...WITH RUC ANALYSIS DEPICTING 850
MB DEWPOINTS OF 9 TO 10 DEGREES CELSIUS JUST UPSTREAM. DEEPER AND
RICHER MOISTURE LIES ACROSS SOUTHEAST HALF OF TEXAS PANHANDLE...SOUTH
AND SOUTHEAST OF KAMA.
THICKENING MID-LEVEL CLOUDS THIS MORNING WILL STILL ALLOW SURFACE TO
WARM...WITH CONVECTIVE TEMPERATURES BEING REACHED BY 21Z. DRYLINE
SHOULD BE POISED NEAR KAMA AT THAT TIME...WITH MODEST INSTABILITY
AXIS IN CLOSE PROXIMITY. ISOLATED TO SCATTERED THUNDERSTORMS ARE
EXPECTED MAINLY AFTER 21Z NEAR KAMA AND KGUY...NEAR DRYLINE AND COLD
FRONT RESPECTIVELY. KDHT LESS LIKELY TO BE IMPACTED DUE TO DRIER
LOW- LEVEL AIR. OCCASIONAL VORTICITY MAXIMA EXPECTED TO PASS OVER
THE FORECAST AREA THIS EVENING AND TONIGHT...PROVIDING SUPPORT FOR
SHOWERS AND THUNDERSTORMS. WILL NOT INCLUDE THUNDER IN FORECASTS AT
THIS TIME...BUT WILL WAIT UNTIL HIGHER CERTAINTY OF TIMING AND
LOCATION OF DEVELOPMENT CAN BE ATTAINED.
COCKRELL
&&
.PREV DISCUSSION... /ISSUED 506 AM CDT WED MAY 21 2014/
DISCUSSION...
PRECIPITATION CHANCES...WHICH START TODAY AND CONTINUE THROUGH THE
MEMORIAL DAY WEEKEND...GRAB THE MAIN FOCUS OF THIS FORECAST.
THE UPPER LOW THAT WILL BRING INCREASING RAIN CHANCES TO THE
PANHANDLES OVER THE NEXT SEVERAL DAYS WAS CENTERED OVER SOUTHERN NV
EARLY THIS MORNING. WATER VAPOR IMAGERY SHOWED INCREASING MID/UPPER-
LEVEL SUBTROPICAL MOISTURE STREAMING NORTHEAST ACROSS THE SOUTHERN
HIGH PLAINS IN BETWEEN THE UPPER LOW AND RIDGING OVER THE LOWER MS
VALLEY. AT THE SURFACE...A COLD FRONT EXTENDED SOUTHWEST ACROSS KS TO
ALONG THE OK PANHANDLE/KS STATE LINE...WITH A DRYLINE EXTENDING
SOUTHWEST ACROSS THE TX PANHANDLE FROM JUST WEST OF PERRYTON TO
BETWEEN AMARILLO AND HEREFORD.
THESE TWO SURFACE BOUNDARIES...THE COLD FRONT AND DRYLINE...WILL BE
INSTRUMENTAL TO THUNDERSTORM CHANCES THIS AFTERNOON AND EVENING. THE
COLD FRONT IS EXPECTED TO PUSH SOUTH INTO THE NORTHERN TX PANHANDLE
THIS MORNING...BEFORE RETREATING NORTHWARD TOWARD THE CO/KS STATE
LINE THIS AFTERNOON. EXPECT THE DRYLINE /FAIRLY DIFFUSE/ TO BE
POSITIONED FROM AROUND SPEARMAN OR PERRYTON SOUTHWEST ROUGHLY ALONG A
BORGER/AMARILLO/HEREFORD LINE MID TO LATE AFTERNOON. WITH MINIMAL
CAPPING AND A WEAK MID-LEVEL SHORTWAVE TROUGH APPROACHING THE
AREA...ISOLATED TO SCATTERED CONVECTION IS EXPECTED TO INITIATE ALONG
THE BOUNDARIES THIS AFTERNOON. SOME OF THE STORMS COULD BE STRONG TO
SEVERE...WITH HAIL UP TO HALF DOLLAR SIZE AND WIND GUSTS TO 60 MPH
THE PRIMARY THREATS. LOW-LEVEL MOISTURE IS STILL SOMEWHAT
LIMITED...SO THE CONVECTION WILL BE FAIRLY HIGH-BASED. 0-1KM MLCAPES
SHOULD REACH AROUND 1500 J/KG TODAY NORTH OF THE FRONT AND EAST OF
THE DRYLINE. DEEP LAYER SHEAR WILL BE WEAKER ALONG THE DRYLINE...BUT
NOT BAD /30-40 KTS/ JUST NORTH OF THE SURFACE FRONT ACROSS THE OK
PANHANDLE...THUS THINK THE FAR NORTHERN PORTION OF THE CWA WILL BE
THE MOST FAVORABLE LOCATION FOR A FEW SEVERE STORMS. KEPT SOME LOW
POPS IN WEST OF THE DRYLINE/SOUTH OF THE FRONT WHERE SOME HIGH-BASED
SHOWERS OR MAYBE A WEAK THUNDERSTORM CAN/T BE RULED OUT DUE TO THE
INCREASING MID-LEVEL MOISTURE...SOME VERY WEAK INSTABILITY...AND THE
AFOREMENTIONED WEAK MID-LEVEL SHORTWAVE. TEMPS WILL BE COOLER TODAY
THAN THE PAST COUPLE OF DAYS...WITH FORECAST HIGHS IN THE LOWER 80S
TO LOWER 90S.
THUNDERSTORM CHANCES WILL BE ON THE INCREASE THURSDAY THROUGH
SATURDAY...AND LINGER THROUGH MONDAY. THE BIG PICTURE HASN/T CHANGED
MUCH...WITH THE UPPER LOW PROGGED TO SLOWLY WOBBLE ACROSS THE
SOUTHWEST THROUGH EARLY SATURDAY MORNING BEFORE LIFTING ACROSS THE
SOUTHERN ROCKIES AND SOUTHERN/CENTRAL HIGH PLAINS OVER THE HOLIDAY
WEEKEND...EVENTUALLY PUSHING EAST OF THE PANHANDLES LATE MONDAY
NIGHT/TUESDAY. LOW-LEVEL GULF MOISTURE WILL ADVECT NORTHWEST THROUGH
THE PANHANDLES INTO EASTERN NM ON THURSDAY...THEN REMAIN IN PLACE
THROUGH THE UPCOMING WEEKEND. THE COMBINATION OF THIS GULF MOISTURE
AND THE SUBTROPICAL MOISTURE TAP ALOFT WILL BOOST PRECIPITABLE WATER
VALUES TO JUST UNDER AN INCH IN THE NORTHWEST PANHANDLES TO NEAR AN
INCH AND A HALF IN THE EASTERN PANHANDLES. DAILY ROUNDS OF
THUNDERSTORMS ARE ANTICIPATED THROUGH MONDAY DUE TO FORCING FROM
EJECTING WEAK SHORTWAVES...BROAD DIFFLUENCE ALOFT...AND DIURNAL
HEATING OF A WEAKLY CAPPED ATMOSPHERE. THE NIGHTLY STRENGTHENING OF
THE LLJ WILL ALSO LIKELY HELP TO SUSTAIN SOME OF THE CONVECTION INTO
THE OVERNIGHT HOURS THURSDAY NIGHT THROUGH SUNDAY NIGHT.
IN TERMS OF SEVERE WEATHER...A FEW STRONG TO SEVERE STORMS WILL BE
POSSIBLE BOTH THURSDAY AND FRIDAY. INSTABILITY WILL BE DECENT WITH
MLCAPES PROGGED AROUND 1500 J/KG EACH DAY...BUT FLOW ALOFT AND
RESULTANT DEEP LAYER SHEAR WILL BE ON THE WEAK SIDE /30 KTS OR LESS/.
THIS WILL BE SUFFICIENT TO SUPPORT SOME STRONG MULTICELLULAR
CONVECTION...BUT WIDESPREAD/ORGANIZED SEVERE WEATHER IS NOT
ANTICIPATED DUE TO THE WEAKER SHEAR. CONDITIONS DO LOOK MORE
FAVORABLE FOR MORE ORGANIZED SEVERE WEATHER SATURDAY AND SUNDAY AS
THE FLOW ALOFT STRENGTHENS AHEAD OF THE APPROACHING UPPER LOW. DEEP
LAYER SHEAR SHOULD INCREASE TO AROUND 40 KTS OR HIGHER ACROSS THE
WESTERN AND CENTRAL PANHANDLES ON SATURDAY...WITH SIMILAR VALUES THAN
TRANSLATING ACROSS THE CENTRAL AND EASTERN PANHANDLES ON SUNDAY. CONTINUED
MOIST LOW-LEVELS AND COOLING TEMPS ALOFT WILL LIKELY LEAD TO MLCAPES
IN THE 1500-2000 J/KG RANGE. ACTUAL VALUES WILL BE MODULATED BY CLOUD
COVER AND POSSIBLE EARLY DAY CONVECTION...LEADING TO SOME UNCERTAINTY
HERE. HOWEVER...IT DOES APPEAR THAT SATURDAY AND SUNDAY WILL BE THE
DAYS TO WATCH FOR MORE ORGANIZED SEVERE CONVECTION. SOME SEVERE
POTENTIAL WILL LINGER ACROSS THE FAR EASTERN PANHANDLES ON
MONDAY...BEFORE THE RAIN AND THUNDERSTORMS SHIFT EAST OUT OF THE AREA
MONDAY NIGHT AS THE UPPER LOW TRACKS EAST INTO KS/OK. HEAVY
RAINFALL...LEADING TO SOME LOCALIZED FLOODING...WILL ALSO BE POSSIBLE
THURSDAY THROUGH MONDAY GIVEN THE AMPLE MOISTURE IN PLACE AND
POSSIBLE TRAINING FROM REPEATED ROUNDS OF CONVECTION.
DRY CONDITIONS WILL RETURN NEXT TUESDAY AND WEDNESDAY AS SUBSIDENCE
TAKES HOLD BEHIND THE DEPARTING UPPER LOW. AFTER A STRETCH OF COOLER
WEATHER THROUGH THE HOLIDAY WEEKEND...TEMPS WILL BEGIN TO REBOUND
TUESDAY AS HEIGHTS RISE AS SHORTWAVE RIDGING BUILDS IN BEHIND THE
UPPER LOW.
KB
FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS THE FAR
WESTERN PANHANDLES THIS AFTERNOON INTO EARLY THIS EVENING. SOUTH TO
SOUTHWEST WINDS ARE EXPECTED TO INCREASE TO 15 TO 20 MPH WHILE
RELATIVE HUMIDITIES FALL TO 10 TO 20 PERCENT. ISOLATED THUNDERSTORMS
IN THIS AREA COULD ALSO PRODUCE A FEW CLOUD-TO-GROUND LIGHTNING
STRIKES AND LITTLE RAINFALL. NO ELEVATED OR CRITICAL FIRE WEATHER
CONDITIONS ARE ANTICIPATED THURSDAY THROUGH EARLY NEXT WEEK DUE TO
INCREASING MOISTURE AND RAINFALL CHANCES.
KB
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 87 61 83 59 79 / 30 30 30 40 50
BEAVER OK 93 63 88 63 84 / 30 30 40 40 50
BOISE CITY OK 84 55 83 56 78 / 20 20 40 40 50
BORGER TX 92 66 87 62 81 / 20 30 30 40 50
BOYS RANCH TX 90 60 84 62 79 / 20 20 40 40 50
CANYON TX 87 60 83 58 79 / 30 30 30 40 50
CLARENDON TX 92 64 85 62 79 / 20 20 20 40 50
DALHART TX 85 56 84 57 77 / 20 20 40 40 50
GUYMON OK 90 59 86 60 80 / 30 20 40 40 50
HEREFORD TX 84 59 82 59 79 / 20 20 30 40 50
LIPSCOMB TX 93 63 89 62 81 / 20 20 20 40 50
PAMPA TX 90 64 84 60 77 / 30 30 20 40 50
SHAMROCK TX 91 64 86 64 81 / 10 10 20 30 40
WELLINGTON TX 93 66 88 66 83 / 5 10 20 30 40
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
03/08
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
614 AM CDT WED MAY 21 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT WED MAY 21 2014
MAIN FORECAST CONCERNS THIS PERIOD...TEMPERATURES AND CLOUD TRENDS.
DATA ANALYSIS AT 06Z HAD THE WEAK SFC TROUGH/FRONT FROM SOUTHWEST IA
TO NEAR KDVN AND CHICAGO. SCT SHRA/TSRA CONTINUED NEAR THIS
BOUNDARY...MOVING EAST/SOUTHEAST AWAY FROM THE FCST AREA. A
SECONDARY SFC TROUGH/FRONT EXTEND FROM A LOW IN SOUTHWEST ONT SOUTH
WARD THRU KDLH AND WESTERN WI. WEST AND NORTH OF THESE BOUNDARIES
DRIER/COOLER CAN HIGH PRESSURE WAS BUILDING INTO THE NORTHERN PLAINS
AND MN. SFC DEW POINTS NEAR/AHEAD OF THE BOUNDARIES IN THE 50S TO
LOWER 60S AND IN THE 40S BEHIND THEM. FOG-PRODUCT IMAGERY SHOWING
PLENTY OF LOWER CLOUDS/MOISTURE OVER EASTERN ND/NORTHWEST MN...
HEADED SOUTHEAST IN THE FLOW BETWEEN THE ONT LOW AND DAKOTAS HIGH.
21.00Z MODELS LOOK TO HAVE INITIALIZED WELL...EXCEPT FOR GFS WITH
ITS 5F TOO HIGH BIAS ON SFC DEW POINTS ACROSS THE MID/UPPER MS
VALLEY. PER 500MB ANALYSIS...MODELS CONVERGING ON A TIGHT CONSENSUS
TODAY/TONIGHT AS THE TROUGHING/ENERGY OVER SOUTHWEST ONT/NORTHERN MN
MOVES EAST AND RIDGING/RISING HGTS BUILD INTO THE NORTHERN PLAINS.
END RESULT IS NORTHWEST FLOW ALOFT OVER THE UPPER MIDWEST THIS
PERIOD. SHORT-TERM FCST CONFIDENCE IS GOOD THIS CYCLE.
IN THE SHORT TERM...WITH NORTHWEST FLOW ALOFT TODAY/TONIGHT THE
CANADIAN HIGH OVER THE DAKOTAS WILL SLOWLY BUILD SOUTHEAST AND END
UP CENTERED OVER MN BY 12Z THU. A DRY...QUIET/COOLER PERIOD FOR
TODAY/TONIGHT UNDER THE INFLUENCE OF THIS HIGH. LOW LEVEL COLD
ADVECTION AHEAD OF THE HIGH SENDS 850MB TEMPS DOWN INTO THE +4C TO
+10C RANGE BY 12Z THU...SO COOLER THIS TIME MEANS HIGHS/LOWS CLOSE
TO NORMAL FOR TODAY/TONIGHT. BIGGEST CONCERN THIS PERIOD IS WHAT
HAPPENS WITH THE STRATO-CU CLOUDS/MOISTURE OVER EASTERN ND/NORTHWEST
MN. MODEL 925-850MB RH PROGS DOING A DECENT JOB WITH THIS MOISTURE/
CLOUDS EARLY THIS MORNING...HOWEVER FOG PRODUCT IMAGERY/SFC OBS SHOW
THE CLOUDS MOVING MORE EAST VS. SOUTHEAST. CURRENT TRAJECTORY WOULD
TAKE THESE CLOUDS/MOISTURE MAINLY ACROSS CLARK/TAYLOR COUNTIES THIS
AFTERNOON/EVENING WHILE MODEL RH PROGS SWEEP THE CLOUDS/MOISTURE AS
FAR SOUTH AS THE MN/IA BORDER. 21.00Z KBIS RAOB SHOWED THIS MOISTURE
TO BE QUITE SHALLOW. WITH DRIER 925-700MB AIR OVER THE AREA THIS
MORNING AND DIURNAL WARMING/MIXING EXPECTED TO 850MB...WILL REMAIN
OPTIMISTIC FOR MORE SUN THAN CLOUDS ACROSS ALL BUT THE FAR NORTH END
OF THE FCST AREA THIS AFTERNOON/EARLY THIS EVENING. MODELS DO SWEEP
THIS MOISTURE EAST OF THE FCST AREA BY LATE EVENING...WITH A DEEP...
DRY AIRMASS OVER THE AREA BY THU MORNING. USED A BLEND OF THE
GUIDANCE HIGHS/LOWS FOR TODAY/TONIGHT.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 317 AM CDT WED MAY 21 2014
MAIN FORECAST CONCERNS FOR THU THRU FRI NIGHT...TEMPERATURES AND
CLOUD TRENDS.
21.00Z MODELS OFFER A TIGHTER CONSENSUS IN THE THU THRU FRI NIGHT
PERIOD WITH QUITE BETWEEN MODEL AND RUN-TO-RUN CONSISTENCY TO
THEIR 19.00Z AND 20.00Z RUNS THRU FRI. BY FRI NIGHT LATEST
CONSENSUS FAVORS MORE PROGRESSIVE OF THE EARLIER RUNS WITH
SHORTWAVE ENERGY/ TROUGHING MOVING THRU THE SOUTHERN TO NORTHERN
ROCKIES. GIVEN THE TIGHT CONSENSUS THRU 12Z SAT AND RIDGING OVER
THE UPPER MIDWEST FOR RATHER TRANQUIL WEATHER...CONFIDENCE IS GOOD
FOR THU THRU FRI NIGHT.
THE TIGHT MODEL CONSENSUS HAS MID LEVEL HGTS OVER THE REGION RISING
THRU THE PERIOD WITH THE 500MB RIDGE AXIS OVER MN/IA AT 12Z SAT.
UNDER THESE RISING HGTS/RIDGE AXIS...THE CAN SFC HIGH OVER WESTERN
MN AT 12Z THU DRIFTS TO LK MICHIGAN BY 12Z SAT. MODEL SOUNDINGS HAVE
THE DEEP DRY LOOK THRU THE PERIOD...WITH PERHAPS SOME DIURNAL
CUMULUS DURING THE AFTERNOON HOURS AND SOME SCT CIRRUS FROM TIME TO
TIME. 850MB TEMP ANOMALIES AROUND -0.5 STANDARD DEVIATION FROM
12Z THU TO 12Z FRI...WARMING TO AROUND +0.5 STANDARD DEVIATION BY
12Z SAT. WITH PLENTY OF SUNSHINE THU/FRI...A DRIER LOW LEVEL
AIRMASS AND EVAPO-TRANSPIRATION 2 TO 3 WEEKS BEHIND...HIGHS
THU/FRI STILL LOOK TO BE NEAR/A BIT ABOVE NORMAL. THE DEEP DRY
AIRMASS AND HIGH NEARBY/ OVERHEAD WILL ALLOW FOR STRONGER
RADIATIONAL COOLING AND LARGER DIURNAL SWINGS AT NIGHT. LOWS
THU/FRI NIGHTS NEAR TO A BIT BELOW NORMAL LOOK GOOD. FAVORED THE
MODEL/ENSEMBLE CONSENSUS OF THE HIGHS/LOWS FOR THU THRU FRI NIGHT.
FOR SATURDAY THROUGH TUESDAY.../DAYS 4 TO 7/...
FORECAST CONCERNS THIS PERIOD...SHRA/TSRA CHANCES STARTING SAT NIGHT
AND CONTINUING THRU TUE...TEMPERATURES.
MEDIUM RANGE MODEL RUNS OF 21.00Z IN GOOD AND IMPROVING AGREEMENT
SAT/SUN AS THE TROUGHING/ENERGY SLOWLY PROGRESS THRU THE ROCKIES AND
INTO THE CENTRAL CONUS. MID LEVEL RIDGE AXIS REMAINS OVER WI/IL THRU
SUN WHILE MN/IA COMING UNDER INCREASINGLY SOUTHWEST ON SUN. LESSER
BETWEEN MODEL AND RUN-TO-RUN CONSISTENCY MON/TUE AS THE SOUTHERN
STREAM TROUGHING SLOWLY LIFTS TOWARD/INTO THE MID/UPPER MS VALLEY.
IMPROVING CONSISTENCY AMONG THE MODELS ON THE NEXT STRONG TROUGHING
TO MOVE INTO THE WESTERN CONUS MON/TUE. EVEN WITH THE IMPROVING
LARGER SCALE CONSENSUS...SMALLER SCALE DETAIL DIFFERENCES PRODUCE
SENSIBLE WEATHER IMPACTS ALREADY SAT NIGHT. FCST CONFIDENCE IS
GOOD SAT THEN AVERAGE FOR SAT NIGHT THRU TUE.
RIDGING ALOFT/CANADIAN SFC HIGH PRESSURE REMAIN THE DOMINANT WEATHER
FEATURES THRU SAT...FOR ANOTHER DRY DAY. 925-850MB TEMPS CONTINUE TO
MODERATE AS THE CORE OF THE HIGH DRIFTS FURTHER EAST OF THE AREA AND
THE LOWER LEVEL FLOW BECOMES MORE SOUTHERLY. 850MB TEMPS IN THE +10C
TO +14C RANGE BY 00Z SUN...FOR ABOVE NORMAL HIGHS ON SAT TO START
THE HOLIDAY WEEKEND. SLOWLY PROGRESSIVE PATTERN AND THE TROUGHING
EJECTING INTO THE PLAINS WOULD THE HOLIDAY WEEKEND WEATHER GOES
DOWNHILL STARTING SAT NIGHT. MODELS START TO SPREAD INCREASING LOWER
LEVEL WARM ADVECTION/LIFT AND MOISTURE TRANSPORT INTO THE AREA SAT
NIGHT SUN...WITH CHANCES OF SHRA/TSRA WEST OF THE MS RIVER LATER SAT
NIGHT AND ACROSS THE AREA SUN. GFS THE MORE ROBUST WITH THIS...BUT
IT ALSO HAS 70F DEW POINTS ACROSS THE FCST AREA AT 00Z MON. THIS
LOOKS SUSPECT WITH THE GFS HIGH DEW POINT BIAS. ALSO LOOKING SUSPECT
IS CONVECTION SO FAR INTO/UNDER THE MID LEVEL RIDGE AXIS/
ANTICYCLONIC FLOW OVER THE MID/UPPER MS VALLEY. SOME OF THIS TIED
TO A WEAK SHORTWAVE THE MODELS PUSH THRU THE MID LEVEL RIDGE AXIS.
LEFT THE MODEL/ENSEMBLE CONSENSUS SHRA/TSRA CHANCES FOR SAT
NIGHT/SUN AS IS. HOWEVER...APPEARS GREATER SHRA/TSRA CHANCES THRU
SUN WOULD BE WEST/NORTH OF THE FCST AREA...CLOSER TO THE LOW LEVEL
TROUGH AND THERMAL/MOISTURE AXES. MAY YET BE ABLE TO SNEAK A
SECOND DRY DAY OUT OF THE HOLIDAY WEEKEND. SLOW EASTWARD
PROGRESSION OF THE LONGWAVE PATTERN MOVES THE LOWER LEVEL
TROUGHING/THETA-E RIDGING INTO/ACROSS THE FCST AREA SUN NIGHT THRU
TUE. SHRA/TSRA CHANCES THESE PERIODS LOOK BETTER TRENDED THAN
THOSE OF SAT NIGHT/SUN.
THRU ALL THIS 850MB TEMPS CONTINUE TO WARM...REACHING 1 TO 1.5
STANDARD DEVIATIONS ABOVE NORMAL BY LATER MON AND TUE. CONSENSUS
HIGHS OF 5 TO 10F ABOVE NORMAL FOR SUN THRU TUE DO LOOK WELL TRENDED
FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 614 AM CDT WED MAY 21 2014
THE WEAK COLD FRONT HAS ALREADY MOVED THROUGH BOTH TAF SITES WITH
THE WINDS COMING AROUND TO THE NORTHWEST. SATELLITE IMAGERY THIS
MORNING IS SHOWING AN AREA OF CLOUDS OVER NORTHWEST MINNESOTA
MOVING SOUTHEAST WITH MVFR TO VFR CEILINGS. BOTH THE 21.06Z NAM
AND 21.09Z RAP INDICATE THE MOISTURE WITH THESE CLOUDS SHOULD STAY
NORTH OF THE TAF SITES UNTIL POSSIBLY COMING IN LATE IN THE
AFTERNOON. FOR NOW...HAVE STAYED WITH JUST SHOWING A SCATTERED
DECK BUT IF THE MOISTURE FIELD HOLDS TOGETHER...MAY NEED TO ADD A
CEILING. THE 21.00Z KBIS SOUNDING INDICATED THE MOISTURE FIELD WAS
PRETTY THIN...SO IT WILL BE INTERESTING TO SEE HOW MUCH OF THIS
SURVIVES THROUGH THE MIXING OF THE DAY.
&&
.HYDROLOGY...
ISSUED AT 317 AM CDT WED MAY 21 2014
WATER LEVELS CONTINUE TO SLOWLY FALL ALONG THE MISSISSIPPI RIVER AND
FEW LOCATIONS REMAIN ABOVE FLOOD STAGE. THE WATER LEVELS WILL REMAIN
HIGH ALONG THE MISSISSIPPI RIVER THROUGH NEXT WEEK.
FOR THE BLACK RIVER...AS FAST AS IT ROSE ABOVE FLOOD STAGE AT BLACK
RIVER FALLS TUE MORNING...IT FELL JUST AS QUICKLY BELOW FLOOD STAGE
TUE EVENING. THE BLACK RIVER IS NO LONGER EXPECTED TO REACH FLOOD
STAGE AT THE GAUGING SITE NEAR GALESVILLE WI.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...04
HYDROLOGY....RRS
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
1125 AM PDT WED MAY 21 2014
...NEW AVIATION/MARINE DISCUSSIONS...
.SYNOPSIS...
LOW PRESSURE WILL LINGER OVER THE AREA THROUGH THURSDAY...BRINGING A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS...MAINLY OVER THE
MOUNTAINS. A GRADUAL WARMING TREND IS EXPECTED THROUGH THE END OF
THE WEEK AS LOW PRESSURE SLOWLY MOVES EAST...WITH TEMPERATURES
RETURNING TO NEAR NORMAL BY FRIDAY. SLIGHTLY ABOVE NORMAL
TEMPERATURES ARE EXPECTED FOR THE WEEKEND AS HIGH PRESSURE RETURNS.
&&
.SHORT TERM (TODAY-FRI)...THE UPPER LOW HAS MOVED INTO NEVADA,
LEAVING US ON THE BACK SIDE OF THE TROF WITH NORTHERLY FLOW AND
STILL DECENT INSTABILITY DURING THE AFTERNOON. MARINE LYR ENDED UP
FILLING IN DECENTLY N OF PT CONCEPTION BUT AS EXPECTED NOT AS SOLID
IN THE SOUTH WITH A MUCH WEAKER AND DEEPER INVERSION. SURFACE
HEATING SHOULD HELP STRATOCU DEVELOP A LITTLE MORE THROUGH THE
AFTERNOON SO PARTLY CLOUDY A GOOD FORECAST FOR MOST COAST/VALLEY
AREAS. GOOD CHANCE OF SOME ISOLATED THUNDERSTORM DEVELOPMENT TODAY,
MAINLY FROM SE SLO COUNTY THROUGH THE SBA AND VENTURA MTNS. SOMEWHAT
LESSER CHANCES OVER LA COUNTY BUT CERTAINLY NOT ZERO. STEERING FLOW
IS FROM THE NORTHWEST AT AROUND 20-25 KT SO THERE IS ALSO A NON-ZERO
CHANCE OF THE REMNANTS OF ANY MTN CONVECTION TO DRIFT SOUTH INTO THE
ADJACENT FOOTHILLS AND VALLEYS. THE HRRR MODEL SHOWS THE BEST
CHANCES OF THIS ACROSS THE VENTURA COUNTY VALLEYS BETWEEN OJAI AND
PIRU LATE THIS AFTERNOON. LIKELY JUST SOME SPRINKLES OR VERY LIGHT
SHOWERS AT BEST.
MODELS CONTINUE TO ADVERTISE ADDITIONAL UPPER LEVEL ENERGY MOVING
INTO THE AREA FROM THE NORTH TONIGHT WHICH MAY BE ENOUGH TO MAINTAIN
A THREAT OF SHOWERS, MAINLY IN THE MTNS. MARINE LYR SITUATION
EXPECTED TO VERY SIMILAR TO THIS MORNING, THUS PRETTY SOLID UP NORTH
AND MORE SCATTERED IN THE SOUTH.
THE NAM HAS GONE BACK TO THU AS IT`S FAVORED CONVECTIVE DAY. IT`S
ALSO SHOWING BETTER INSTABILITY OVER THE VALLEYS WHILE THE STEERING
FLOW SHIFTS TO THE NORTHEAST. WILL CERTAINLY BE LOOKING INTO ADDING
SOME POPS FOR VALLEY AREAS FOR THU, ESPECIALLY IF WE GET SOME DRIFT
OFF TODAY. TEMPERATURES PERHAPS A SKOSH WARMER BUT JUST A COUPLE
DEGREES AT MOST.
***FROM PREVIOUS DISCUSSION***
THE MARINE LAYER WILL REESTABLISH ITSELF THU NIGHT AND SHOULD COVER
MOST OF THE COASTS AS WELL AS THE SANTA YNEZ VLY. ANOTHER WEAK
SUNDOWNER SHOULD KEEP THE SBA SOUTH COAST CLOUD FREE.
FRIDAY IS AN IN BETWEEN DAY AS THE PESKY UPPER LOW SLOWLY MOVES TO
THE EAST AND AN UPPER HIGH NOSES INTO NRN CA FROM THE WEST. SKIES
MAY BE PARTLY CLOUDY OVER L.A. COUNTY AS THE LAST EFFECTS OF THE UPR
LOW WILL STILL BE OVER IT. OTHERWISE THE BUILDING UPPER HIGH WILL
BRING MOSTLY CLEAR SKIES AND SOME WARMING ESP TO THE INTERIOR OF SLO
COUNTY WHICH WILL SEE THE GREATEST HGT RISES.
.LONG TERM (SAT-TUE)...
THE UPPER HIGH TAKES CONTROL OF THE HOLIDAY WEEKEND. THE WARM AIR
ALOFT WILL ESTABLISH A STRONG MARINE INVERSION BUT THE HIGH PRESSURE
ALOFT WILL SMOOSH THE MARINE LAYER TO ABOUT 1000 FEET OR TOO LOW TO
MAKE ANY SIGNIFICANT VLY PENETRATION. MAX TEMPS WILL JUMP NICELY
EVERYWHERE EXCEPT THE COAST AND TO SOME DEGREE THE VLYS WHERE THE
MARINE LAYER AND A STIFF SEA BREEZE WILL SERVE TO MODERATE THE WARM
UP. THE CSTS SHOULD STAY BELOW NORMAL AND THE VLYS WILL ONLY WARM TO
JUST BELOW NORMAL. THE MTNS AND THE REST OF THE INTERIOR WILL WARM
TO ABOVE NORMAL. RIGHT NOW SUNDAY LOOKS LIKE THE WARMEST DAY BUT
MDLS SOMETIMES COOL THINGS OFF TOO QUICKLY SO MONDAY COULD PRETTY
EASILY BE A REPEAT OF SUNDAY. EITHER WAY NOT BAD A HOLIDAY WEEKEND
AT ALL.
THE RIDGE FLATTENS OUT TUESDAY AND MAX TEMPS SHOULD COOL 3 TO 6
DEGREES. THE MARINE LAYER SHOULD SNEAK INTO THE VLYS AS WELL.
&&
.AVIATION...21/1800Z.
LOW CONFIDENCE IN THE 18Z TAF PACKAGE. A LARGE CUTOFF LOW HAS A
LARGE CLOUD SHIELD ROTATING AROUND IT AND THE LOW IS HEADING FOR LOS
ANGELES COUNTY ON THURSDAY. THE TAF PACKAGE WAS CHANGED TO BE MORE
PESSIMISTIC IN TERMS OF GREATER CLOUD COVERAGE. A CHAOTIC
STRATOCUMULUS DECK IS FORMING IN THE DAYTIME HEATING TODAY...SO THAT
ANY TAF SITE MAY SEE BKN CONDITIONS AT JUST ABOUT ANY TIME OF DAY
AND THE SITUATUION ONLY GESTS WORSE FOR THURSDAY. THERE WILL BE NO
TEMPORAL CONSISTENCY IN CLOUD COVER WITH SCT TO BKN CONDITIONS AND
OCCASIONAL MVFR CEILINGS FOR THE NEXT 24 HOURS. THE ANTELOPE VALLEY
WILL HAVE GUSTY WINDS IN THE AFTERNOON AND EVENING. IN ADDITION...A
FEW SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED OVER THE
MOUNTAINS THROUGH THURSDAY WITH THE HIGHEST CHANCES DURING THE
AFTERNOON AND EARLY EVENING. ONE OR TWO SHOWERS MAY EVEN DRIFT INTO
THE LA/VENTURA COUNTY VALLEYS ON THURSDAY.
KLAX AND KBUR...LOW CONFIDENCE IN THE 18Z TAF FORECAST. THERE WILL
BE PERIODS OF CLOUDINESS AND SCT TO BKN CONDITIONS WITH OCCASIONAL
MVFR CONDITIONS.
&&
.MARINE...21/900 AM...
ACROSS THE OUTER WATERS...MODERATE CONFIDENCE IN SMALL CRAFT
ADVISORY LEVEL WINDS THROUGH THIS EVENING. THERE IS A CHANCE THAT
WINDS COULD REMAIN AT SMALL CRAFT LEVELS THROUGH THURSDAY. FOR
FRIDAY THROUGH THE WEEKEND...WINDS ARE ANTICIPATED TO CONTINUE AT
LEAST AROUND THE SMALL CRAFT ADVISORY LEVELS. THE LATEST MODEL DATA
DOES SHOW THE POSSIBILITY OF GALE FORCE WINDS RETURNING TO PZ670 AND
PZ673 FRIDAY EVENING AND CONTINUING INTO SATURDAY. THERE IS LOW TO
MODERATE CONFIDENCE IN THIS SCENARIO.
ACROSS THE INNER WATERS...WINDS ARE GENERALLY EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY LEVELS THROUGH THE WEEKEND. WESTERN
SECTIONS COULD EXPERIENCE SOME LOCAL GUSTS TO 25 KNOTS...ESPECIALLY
IN THE AFTERNOON AND EVENING HOURS. THERE IS GOOD CONFIDENCE IN THIS
SCENARIO.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...MW/RORKE
AVIATION/MARINE...SWEET
SYNOPSIS...SUKUP
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS RENO NV
1040 AM PDT WED MAY 21 2014
.UPDATE...
UPDATED TO RAISE AFTERNOON POP, MAINLY FOR FAR WESTERN NEVADA. I
ALSO LOWERED HIGHS A FEW DEGREES, GENERALLY SOUTH OF A GERLACH TO
PORTOLA LINE, WITH MORE SHOWERS EXPECTED FOR THIS AFTERNOON. AS
FAR AS THE POP INCREASE, THE NAM AND HRRR MODELS APPEAR TO BE ON
TRACK FOR THIS AFTERNOON (WITH BRINGING A BAND OF SHOWERS/POSSIBLE
STORMS INTO WESTERN NEVADA) BASED ON RECENT RADAR AND SATELLITE
OBSERVATIONS SO THOSE SOLUTIONS WERE ACCEPTED. SNYDER
&&
.SYNOPSIS...
LOW PRESSURE LINGERING OVER CALIFORNIA AND NEVADA WILL CONTINUE TO
BRING COOLER AND BREEZY CONDITIONS ALONG WITH RAIN SHOWERS, ISOLATED
THUNDERSTORMS AND HIGH ELEVATION SNOW THROUGH EARLY THURSDAY. HIGH
PRESSURE WILL SLOWLY BUILD BACK INTO THE REGION BRINGING WARMER AND
DRIER CONDITIONS FOR THE END OF THE WEEK.
&&
.PREVIOUS DISCUSSION... /ISSUED 321 AM PDT WED MAY 21 2014/
SHORT TERM...
ONLY SLIGHT ADJUSTMENTS WERE NECESSARY TO THE EXISTING FORECAST.
THIS MAINLY CONCERNED INCREASING EXTENT OF LOW CHANCES OF SHOWERS
WITH ISOLATED THUNDERSTORMS NORTHWEST INTO NORTHWESTERN LASSEN
COUNTY. OTHERWISE, VERY LITTLE HAS CHANGED. LOW PRESSURE CONTINUES
TO INFLUENCE THE PATTERN BRINGING MORE SHOWERS AND ISOLATED
THUNDERSTORMS TODAY. ALTHOUGH, PRECIPITATION WILL NOT BE NEARLY AS
CONSISTENT AS YESTERDAY. WILL CONTINUE TO WATCH THE HUNTER FALLS
BURN SCAR IN CASE CELLS BEGIN TO TRAIN OR BECOME ANCHORED SINCE
UPPER FLOW IS UPSLOPE OUT OF THE NORTHEAST BECOMING RATHER LIGHT
THROUGH THE DAY. HOWEVER, THIS IS ON THE LOWER END OF POSSIBILITY
SINCE SHOWERS SHOULD BE MORE SCATTERED TODAY.
SHORT-TERM MODELS HAVE SHOWN MORE INSTABILITY AND MOISTURE FARTHER
NORTHWEST DURING THE AFTERNOON TODAY. ALSO, THEY ARE A LITTLE
SLOWER WITH THE EXIT OF LOW PRESSURE. AS A RESULT, HAVE ADDED
THE POSSIBILITY OF SHOWERS WITH ISOLATED THUNDERSTORMS FOR MUCH OF
LASSEN COUNTY WITH HIGHER CHANCES ALONG THE WARNERS. SHOWERS SEEMS
TO BE LINGERING FOR MONO COUNTY AS WELL. KEPT LIKELY WORDING
THROUGH THIS EVENING.
HIGH PRESSURE BEGINS TO DISPLACE THE LOW THURSDAY AFTERNOON AND
EVENING RETURNING THE AREA TO A WARMING TREND. HIGH TEMPERATURES
QUICKLY REBOUND BY FRIDAY WITH WESTERN NEVADA VALLEYS IN THE MID
80S AND MOSTLY CLEAR SKIES. ANOTHER WEAK TROUGH TRIES TO MOVE INTO
THE RIDGE IN NORTHERN LASSEN COUNTY EARLY FRIDAY, BUT DID NOT
RAISE PRECIPITATION CHANCES YET. WAITING FOR A CLEARER SIGNAL THAT
THE TROUGH WILL BE STRONG ENOUGH TO DEPRESS THE NORTHERN PERIPHERY
OF THE RIDGE. BOYD
LONG TERM...SATURDAY THROUGH TUESDAY...
UPPER LOW CONTINUES TO PUSH EAST OVER THE WEEKEND, ALLOWING FOR
RIDGING TO BUILD BACK OVER NORTHERN CA/NV. 700MB TEMPERATURES WILL
INCREASE SHARPLY OVER THE WEEKEND, TOPPING OFF AT AROUND +10C. THIS
WILL MEAN HIGH TEMPS IN THE LOWER ELEVATIONS REACHING INTO THE UPPER
80S WITH 70S IN THE SIERRA. THE STRONG HEATING WILL ALSO LEAD TO
INCREASED INSTABILITY OVER THE SIERRA. INTRODUCED A SLIGHT CHANCE OF
THUNDERSTORMS OVER THE SIERRA CREST ON SATURDAY AND SUNDAY
AFTERNOON/EVENINGS. THERE ISN`T MUCH IN THE WAY OF FORCING, SO
THUNDERSTORM DEVELOPMENT LOOKS VERY MARGINAL. ALTHOUGH, WITH THE
AMOUNT OF HEATING AND INSTABILITY WE WILL SEE THIS WEEKEND, A SLIGHT
CHANCE OF THUNDERSTORMS IS POSSIBLE.
BY MEMORIAL DAY, LOW PRESSURE BEGINS TO DROP INTO THE PAC NW. THE
JET STREAM LOOKS TO REMAIN OVER WA/OR, WHICH IS TRENDING FURTHER
NORTH THAN WE`VE SEEN OVER THE LAST FEW DAYS. THIS WILL STILL LEAD
TO GUSTY WINDS ON MONDAY ALTHOUGH MAYBE NOT QUITE AS STRONG AS
PREVIOUSLY THOUGHT. STILL, GUSTY WINDS UP TO 35-40 MPH COULD CREATE
PROBLEMS FOR AREA LAKES ON MEMORIAL DAY. SINCE THE MOISTURE WILL
REMAIN WELL TO THE NORTH IN THE PAC NW, WARM AND DRY CONDITIONS MAY
COMBINE WITH GUSTY WINDS ON MONDAY FOR FIRE WEATHER CONCERNS.
BACK DOOR COLD FRONT WILL PUSH DOWN THROUGH THE GREAT BASIN ON
TUESDAY. THIS WILL BRING TEMPERATURES BACK DOWN TO NEAR NORMALS WITH
MID TO UPPER 70S IN THE DESERT VALLEYS AND 60S IN THE SIERRA. HOON
AVIATION...
BAND OF RAIN AND HIGH ELEVATION SNOW WILL CONTINUE TO AFFECT WESTERN
NEVADA THROUGH TODAY. MVFR CIGS WILL BE POSSIBLE FOR AREA TERMINALS
THROUGH THIS AFTERNOON. A FEW THUNDERSTORMS ARE ALSO POSSIBLE THIS
AFTERNOON AS WE GET ADDITIONAL HEATING. THUNDERSTORMS WILL BE PRETTY
ISOLATED WITH ONLY A 10% CHANCE OF THUNDERSTORMS AFFECTING EACH
TERMINAL. HOON
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
935 AM PDT WED MAY 21 2014
.SYNOPSIS...
LOW PRESSURE WILL LINGER OVER THE AREA THROUGH THURSDAY...BRINGING A
SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS...MAINLY OVER THE
MOUNTAINS. A GRADUAL WARMING TREND IS EXPECTED THROUGH THE END OF
THE WEEK AS LOW PRESSURE SLOWLY MOVES EAST...WITH TEMPERATURES
RETURNING TO NEAR NORMAL BY FRIDAY. SLIGHTLY ABOVE NORMAL
TEMPERATURES ARE EXPECTED FOR THE WEEKEND AS HIGH PRESSURE RETURNS.
&&
.SHORT TERM (TODAY-FRI)...THE UPPER LOW HAS MOVED INTO NEVADA,
LEAVING US ON THE BACK SIDE OF THE TROF WITH NORTHERLY FLOW AND
STILL DECENT INSTABILITY DURING THE AFTERNOON. MARINE LYR ENDED UP
FILLING IN DECENTLY N OF PT CONCEPTION BUT AS EXPECTED NOT AS SOLID
IN THE SOUTH WITH A MUCH WEAKER AND DEEPER INVERSION. SURFACE
HEATING SHOULD HELP STRATOCU DEVELOP A LITTLE MORE THROUGH THE
AFTERNOON SO PARTLY CLOUDY A GOOD FORECAST FOR MOST COAST/VALLEY
AREAS. GOOD CHANCE OF SOME ISOLATED THUNDERSTORM DEVELOPMENT TODAY,
MAINLY FROM SE SLO COUNTY THROUGH THE SBA AND VENTURA MTNS. SOMEWHAT
LESSER CHANCES OVER LA COUNTY BUT CERTAINLY NOT ZERO. STEERING FLOW
IS FROM THE NORTHWEST AT AROUND 20-25 KT SO THERE IS ALSO A NON-ZERO
CHANCE OF THE REMNANTS OF ANY MTN CONVECTION TO DRIFT SOUTH INTO THE
ADJACENT FOOTHILLS AND VALLEYS. THE HRRR MODEL SHOWS THE BEST
CHANCES OF THIS ACROSS THE VENTURA COUNTY VALLEYS BETWEEN OJAI AND
PIRU LATE THIS AFTERNOON. LIKELY JUST SOME SPRINKLES OR VERY LIGHT
SHOWERS AT BEST.
MODELS CONTINUE TO ADVERTISE ADDITIONAL UPPER LEVEL ENERGY MOVING
INTO THE AREA FROM THE NORTH TONIGHT WHICH MAY BE ENOUGH TO MAINTAIN
A THREAT OF SHOWERS, MAINLY IN THE MTNS. MARINE LYR SITUATION
EXPECTED TO VERY SIMILAR TO THIS MORNING, THUS PRETTY SOLID UP NORTH
AND MORE SCATTERED IN THE SOUTH.
THE NAM HAS GONE BACK TO THU AS IT`S FAVORED CONVECTIVE DAY. IT`S
ALSO SHOWING BETTER INSTABILITY OVER THE VALLEYS WHILE THE STEERING
FLOW SHIFTS TO THE NORTHEAST. WILL CERTAINLY BE LOOKING INTO ADDING
SOME POPS FOR VALLEY AREAS FOR THU, ESPECIALLY IF WE GET SOME DRIFT
OFF TODAY. TEMPERATURES PERHAPS A SKOSH WARMER BUT JUST A COUPLE
DEGREES AT MOST.
***FROM PREVIOUS DISCUSSION***
THE MARINE LAYER WILL REESTABLISH ITSELF THU NIGHT AND SHOULD COVER
MOST OF THE COASTS AS WELL AS THE SANTA YNEZ VLY. ANOTHER WEAK
SUNDOWNER SHOULD KEEP THE SBA SOUTH COAST CLOUD FREE.
FRIDAY IS AN IN BETWEEN DAY AS THE PESKY UPPER LOW SLOWLY MOVES TO
THE EAST AND AN UPPER HIGH NOSES INTO NRN CA FROM THE WEST. SKIES
MAY BE PARTLY CLOUDY OVER L.A. COUNTY AS THE LAST EFFECTS OF THE UPR
LOW WILL STILL BE OVER IT. OTHERWISE THE BUILDING UPPER HIGH WILL
BRING MOSTLY CLEAR SKIES AND SOME WARMING ESP TO THE INTERIOR OF SLO
COUNTY WHICH WILL SEE THE GREATEST HGT RISES.
.LONG TERM (SAT-TUE)...
THE UPPER HIGH TAKES CONTROL OF THE HOLIDAY WEEKEND. THE WARM AIR
ALOFT WILL ESTABLISH A STRONG MARINE INVERSION BUT THE HIGH PRESSURE
ALOFT WILL SMOOSH THE MARINE LAYER TO ABOUT 1000 FEET OR TOO LOW TO
MAKE ANY SIGNIFICANT VLY PENETRATION. MAX TEMPS WILL JUMP NICELY
EVERYWHERE EXCEPT THE COAST AND TO SOME DEGREE THE VLYS WHERE THE
MARINE LAYER AND A STIFF SEA BREEZE WILL SERVE TO MODERATE THE WARM
UP. THE CSTS SHOULD STAY BELOW NORMAL AND THE VLYS WILL ONLY WARM TO
JUST BELOW NORMAL. THE MTNS AND THE REST OF THE INTERIOR WILL WARM
TO ABOVE NORMAL. RIGHT NOW SUNDAY LOOKS LIKE THE WARMEST DAY BUT
MDLS SOMETIMES COOL THINGS OFF TOO QUICKLY SO MONDAY COULD PRETTY
EASILY BE A REPEAT OF SUNDAY. EITHER WAY NOT BAD A HOLIDAY WEEKEND
AT ALL.
THE RIDGE FLATTENS OUT TUESDAY AND MAX TEMPS SHOULD COOL 3 TO 6
DEGREES. THE MARINE LAYER SHOULD SNEAK INTO THE VLYS AS WELL.
&&
.AVIATION...21/1140Z...
OVERALL...MODERATE CONFIDENCE IN 12Z TAF PACKAGE. CURRENT MVFR CONDS
ACROSS THE CENTRAL COAST AND LAX COAST SHOULD MIX OUT BY LATE THIS
MORNING. OTHERWISE...EXPECT SCT TO LOCALLY BKN VFR CLOUD DECK
THROUGH THIS EVENING. FOR TONIGHT...MODERATE CONFIDENCE IN RETURN OF
MVFR CIGS TO THE CENTRAL COAST AND LAX COAST.
KLAX...MODERATE CONFIDENCE IN 12Z TAF. THERE IS A 50% CHANCE THAT
CURRENT MVFR CIGS COULD MIX OUT BEFORE 16Z. FOR TONIGHT...LOW
CONFIDENCE IN RETURN OF MVFR CIGS. EAST WINDS THIS MORNING SHOULD
REMAIN BELOW 7 KNOTS.
KBUR...HIGH CONFIDENCE IN 12Z TAF. THERE IS A 20% CHANCE OF MVFR
CIGS LATE TONIGHT...AFTER 10Z.
&&
.MARINE...21/900 AM...
ACROSS THE OUTER WATERS...MODERATE CONFIDENCE IN SMALL CRAFT
ADVISORY LEVEL WINDS THROUGH THIS EVENING. THERE IS A CHANCE THAT
WINDS COULD REMAIN AT SMALL CRAFT LEVELS THROUGH THURSDAY. FOR
FRIDAY THROUGH THE WEEKEND...WINDS ARE ANTICIPATED TO CONTINUE AT
LEAST AROUND THE SMALL CRAFT ADVISORY LEVELS. THE LATEST MODEL DATA
DOES SHOW THE POSSIBILITY OF GALE FORCE WINDS RETURNING TO PZ670 AND
PZ673 FRIDAY EVENING AND CONTINUING INTO SATURDAY. THERE IS LOW TO
MODERATE CONFIDENCE IN THIS SCENARIO.
ACROSS THE INNER WATERS...WINDS ARE GENERALLY EXPECTED TO REMAIN
BELOW SMALL CRAFT ADVISORY LEVELS THROUGH THE WEEKEND. WESTERN
SECTIONS COULD EXPERIENCE SOME LOCAL GUSTS TO 25 KNOTS...ESPECIALLY
IN THE AFTERNOON AND EVENING HOURS. THERE IS GOOD CONFIDENCE IN THIS
SCENARIO.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
&&
$$
PUBLIC...MW/RORKE
AVIATION/MARINE...RAT/SWEET
SYNOPSIS...SUKUP
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1140 AM MDT WED MAY 21 2014
.UPDATE...
ISSUED AT 1111 AM MDT WED MAY 21 2014
CURRENT FORECAST/SEVERE THREAT LOOKS ON TRACK...WITH LATEST HRRR
RUNS SUGGESTING CONVECTIVE INITIATION BETWEEN 19Z-20Z. STILL
APPEARS BEST TORNADO/SUPERCELL THREAT WILL BE NORTH NEAR THE
DCVZ INTO NE CO...WITH MORE OF A WIND/HAIL THREAT FARTHER SOUTH
WHERE T/TD SPREADS WILL BE LARGER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM MDT WED MAY 21 2014
...SEVERE THUNDERSTORMS POSSIBLE NORTHERN PORTIONS OF THE SOUTHEAST
PLAINS...CRITICAL FIRE WEATHER CONDITIONS EXPECTED ACROSS THE SAN
LUIS VALLEY...
UPPER LOW WILL STALL OUT OVER NEVADA TODAY BEFORE DROPPING SOUTHWARD
INTO SOUTHERN CA LATER TONIGHT. SOUTHERLY FLOW AHEAD OF THE SYSTEM
TODAY WILL START TO SHIFT SOME MID/HIGH LEVEL MOISTURE INTO THE
WESTERN MTS TODAY...BUT BY IN LARGE...LOWER LEVELS WILL REMAIN QUITE
DRY. WITH SOUTH TO SOUTHWEST WINDS INCREASING AGAIN ACROSS THE
SOUTHWEST MTS AND SAN LUIS VALLEY...EXPECT A RETURN OF CRITICAL FIRE
WEATHER CONDITIONS FOR THE SAN LUIS VALLEY WHERE FUELS ARE
CRITICALLY DRY. RAPID RATES OF FIRE SPREAD WILL BE POSSIBLE WITH
ANY FIRE STARTS AND CURRENT RED FLAG WARNING STILL LOOKS GOOD.
THERE COULD BE SOME ISOLATED HIGH BASED THUNDERSTORMS ALONG THE
CONTDVD TODAY...BUT THEY WILL BE FEW AND FAR BETWEEN...AND WITH
INVERTED V SOUNDINGS...MORE LIKELY TO PRODUCE GUSTY WINDS THAN MUCH
IN THE WAY OF RAINFALL.
DIFFERENT STORY WILL EXIST TODAY FOR THE SOUTHEAST PLAINS. LOW LEVEL
MOISTURE HAS SPREAD BACK IN WITH CURRENT DEW POINTS IN THE 50S FOR
THE LOWER ARKANSAS RIVER...WITH UPPER 40S FOR CANON CITY...AND EVEN
WOODLAND PARK SEEING LOWER 40 DEW POINTS. SOUTHERN I-25 CORRIDOR IS
STILL QUITE DRY WITH KTAD DEW POINT AT 13 AS OF 09Z. BOUNDARY WILL
CONTINUE TO PUSH SLOWLY SOUTHWARD THIS MORNING WITH STRATUS
EXPANDING ACROSS SOUTHEAST CO IN LIGHT UPSLOPE REGIME ALONG THE
LOWER EASTERN SLOPES OF TELLER/EL PASO COUNTY...THE LOWER WET
MOUNTAINS...AND THE NORTHERN SLOPES OF THE RATON RIDGE. THIS SHOULD
BURN OFF DURING THE LATE MORNING WITH DEW POINTS STAYING IN THE
UPPER 40S/LOWER 50S THROUGH EARLY AFTERNOON ACROSS THE MAJORITY OF
THE SOUTHEAST PLAINS. VORT MAX ACROSS NEW MEXICO WILL MOVE IN THIS
AFTERNOON...AND DRIER AIR WILL BEGIN TO MIX NORTHWARD OFF THE RATON
RIDGE. MAIN FACTOR DETERMINING EXTENT OF SEVERE WEATHER POTENTIAL
WILL BE HOW QUICKLY THESE DEW POINTS MIX OUT. HRRR AND RAP13 DROPS
DEW POINTS INTO THE UPPER 30S FOR THE I-25 CORRIDOR WITH 40S FARTHER
EAST BY 21Z. NAM12 AND LOCAL 4KM WRF KEEPS DEW POINTS IN THE LOWER
50S AT 21Z NORTHEAST OF A LINE FROM KCOS...TO KLHX...TO KSPD. SO
CAPES COULD BE AS LOW AS 500 J/KG ALONG THE I-25 CORRIDOR TO AROUND
1500 J/KG ACROSS KIOWA...BENT...PROWERS COUNTIES IF THE RAP IS
CORRECT. OR THEY COULD BE AROUND 1500+ J/KG IF THE NAM12 IS
CORRECT. EITHER WAY...0-6KM SHEARS WILL BE RUNNING AROUND 40-50
KTS...OR EVEN A LITTLE BETTER IF LOW LEVEL WINDS STAY OUT OF THE
EAST...WHICH WOULD SUPPORT DEVELOPMENT OF SUPERCELL THUNDERSTORMS.
BEST CHANCES FOR SEVERE LOOK TO BE ACROSS NORTHERN SECTIONS OF THE
SOUTHEAST PLAINS...WHERE HIGHER DEW POINTS ARE MORE LIKELY TO STAY
IN THE LONGEST. INITIATION MAY OCCUR ALONG THE NORTHERN SLOPES OF
THE RATON MESA AROUND 1 PM...WITH THUNDERSTORMS SPREADING/DEVELOPING
NORTHWARD ACROSS THE SOUTHEAST PLAINS THROUGH THE AFTERNOON.
MAJORITY OF THE ACTIVITY MOVES OUT OF THE AREA BY 00Z AS VORT MAX
LIFTS NORTHWARD. LARGE HAIL AND DAMAGING WINDS WILL BE THE MOST
LIKELY SEVERE THREAT...ESPECIALLY TO THE NORTH OF THE ARKANSAS
RIVER. IF DEW POINTS CAN STAY HIGH ENOUGH...THUS...LCLS LOW
ENOUGH...THERE COULD BE ENOUGH LOW LEVEL HELICITY FOR AN ISOLATED
TORNADO. THIS WOULD BE MORE LIKELY TO OCCUR ALONG THE PALMER DIVIDE
AND KIOWA COUNTY...BUT THREAT FOR THIS APPEARS ON THE LOWER SIDE OF
THE SPECTRUM AT THIS POINT. POTENTIAL FOR DAMAGING WIND GUSTS WILL
EXTEND FARTHER SOUTHWARD ACROSS THE SOUTHEAST PLAINS THAN HAIL
THREAT DUE TO HIGHER AVAILABLE DOWNDRAFT CAPE. WILL LIKELY PLAY THE
SEVERE THREAT AREA NORTHEAST OF A LINE FROM COLORADO SPRINGS...TO LA
JUNTA...TO TWO BUTTES.
FINAL CONCERN IS FOR POTENTIAL FOR HEAVY RAINFALL ON THE BURN SCARS
THIS AFTERNOON...PARTICULARLY ACROSS WALDO AND BLACK FOREST. WINDOW
FOR GREATEST THREAT WILL BE FROM 2 PM TO 6 PM...PROBABLY CENTERED
MORE IN THE 3 TO 5 PM RANGE FOR WALDO. AGAIN...STRENGTH OF
UPDRAFTS/POTENTIAL RAINFALL EFFICIENCIES WILL DEPEND ON HOW MUCH LOW
LEVEL MOISTURE STAYS IN. HUNCH IS THAT HIGHER TERRAIN WILL MIX OUT
AT LEAST SOME OF THE LOW LEVEL MOISTURE AND LCLS WILL BE UP AROUND
11-12KFT MSL...WHICH WILL ALLOW FOR SOME EVAPORATION BELOW CLOUD
BASE. ALTHOUGH THREAT FOR FLASH FLOOD PRODUCING RAINFALL IS THERE
TODAY...THINK THE THREAT IS BELOW A 40 PERCENT PROBABILITY. MORE
LIKELY SCENARIO IS FOR SOME RAINFALL AMOUNTS GENERALLY IN THE
.10 TO .40 RANGE...WHICH COULD MEAN SOME FLOOD ADVISORY RAINFALL
CAUSING MINOR RUN OFF FOR THE WALDO BURN SCAR. MAJORITY OF THE HIGH
RES MODELS SUGGEST THE LESSER IMPACT SCENARIO...BUT SITUATION WILL
REQUIRE CLOSE MONITORING THROUGH THE AFTERNOON AND EARLY EVENING
HOURS.
THUNDERSTORMS WILL COME TO AN END DURING THE EVENING FOR MOST
AREAS...WITH ANOTHER INTRUSION OF STRATUS TOWARDS MORNING ACROSS
NORTHERN PORTIONS OF THE SOUTHEAST PLAINS. -KT
.AVIATION... MVFR CIGS WILL CONTINUE TO EXPAND ACROSS THE SOUTHEAST
PLAINS THROUGH MORNING...WITH SOME POCKETS OF IFR CIGS ACROSS THE
PIKES PEAK REGION AND ALONG THE LOWER EASTERN SLOPES OF THE
SOUTHEAST MOUNTAINS. COULD EVEN SEE SOME PATCHY FOG. STRATUS
SHOULD ERODE BY 17-18Z FOR MOST AREAS WITH ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING DURING THE EARLY AFTERNOON ACROSS THE
SOUTHEAST MOUNTAINS AND NORTHERN SLOPES OF THE RATON RIDGE. THESE
WILL BE CAPABLE OF PRODUCING VFR TO LOCAL MVFR CIGS/VIS. LARGE HAIL
AND ERRATIC WIND GUSTS TO AROUND 50 KTS WILL BE POSSIBLE NORTH OF A
LINE FROM KCOS THE KLHX TO NORTH OF KSPD. THREAT DIMINISHES AFTER
00Z FOR THE KCOS AND KPUB TAF SITES. KALS WILL REMAIN DRY TODAY
WITH VFR CONDITIONS...THOUGH EXPECT A RETURN OF SOUTHWEST WINDS 15-
30 KTS IN THE AFTERNOON. -KT
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 523 AM MDT WED MAY 21 2014
NOT MANY ADJUSTMENTS NEEDED FOR THE LONGER TERM AS UNSETTLED
PATTERN IS STILL ANTICIPATED WITH LONGER TERM METEOROLOGICAL
ISSUES REMAINING POPS...SEVERE WEATHER THREAT AT TIMES WITH
INITIAL LONGER TERM FOCUS FOR SEVERE WEATHER FROM THURSDAY INTO
THURSDAY NIGHT...LOCALLY HEAVY RAINFALL AND ASSOCIATED BURN SCAR
FLOODING THREAT AND TEMPERATURES.
RECENT LONGER TERM FORECAST MODEL SOUNDINGS AND COMPUTER
SIMULATIONS CONTINUE TO SUGGEST THAT CLOSED UPPER LOW LOCATED
OVER SOUTHERN NEVADA AT 00Z FRIDAY WILL SHIFT INTO THE 4-CORNERS
REGION BY 00Z SUNDAY AND THEN SLOWLY MOVES ACROSS SOUTHERN
COLORADO INTO MONDAY MORNING BEFORE MOVING EAST OF THE FORECAST
DISTRICT BY MONDAY NIGHT/TUESDAY MORNING.
UNSETTLED METEOROLOGICAL CONDITIONS(PRIMARILY IN THE FORM OF
RAIN...HEAVY AT TIMES AS WELL AS STRONG TO SEVERE STORMS AT
TIMES) ARE ANTICIPATED FROM THURSDAY INTO MONDAY. AT THIS
TIME...IT APPEARS THAT THE HIGHEST POTENTIAL FOR SEVERE
THUNDERSTORMS(ESPECIALLY EASTERN SECTIONS) DURING THE LONGER
TERM SHOULD BE REALIZED FROM THURSDAY INTO THURSDAY
NIGHT...ESPECIALLY IF ENOUGH ADEQUATE ATMOSPHERIC MOISTURE
INTERACTS WITH SOMEWHAT FAVORABLE 0 TO 6 KM BULK SHEAR VALUES.
RECENT SPC 2ND DAY OUTLOOK(FOR THURSDAY) HAS A LARGE PORTION OF
EASTERN COLORADO COVERED WITH A SLIGHT RISK OF SEVERE
THUNDERSTORMS.
IN ADDITION...PRECIPITATION...HEAVY AT TIMES(WHICH WILL BE CAPABLE
OF PRODUCING FLOODING CONCERNS/ISSUES AT TIMES...ESPECIALLY OVER
THE AREA BURN SCARS)...IS ANTICIPATED AS THE UPPER SYSTEM IMPACTS
THE FORECAST DISTRICT FROM LATE THIS WEEK INTO EARLY NEXT WEEK. AS
ALWAYS...WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY.
IMPROVING METEOROLOGICAL CONDITIONS SHOULD THEN BY NOTED BY
TUESDAY AS THE CLOSED UPPER LOW IS PROJECTED TO MOVE EAST OF THE
FORECAST DISTRICT. TEMPERATURES ARE STILL EXPECTED TO RUN NEAR
LATE MAY CLIMATOLOGICAL AVERAGES DURING THE LONGER TERM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1129 AM MDT WED MAY 21 2014
MVFR STRATUS HAS ERODED OVER MUCH OF THE PLAINS AS OF 18Z...WITH
ISOLATED THUNDERSTORMS ALREADY DEVELOPING OVER THE MOUNTAINS WEST
OF KDEN. EXPECT ISOLATED TO SCATTERED TSRA OVER MUCH OF THE AREA
THIS AFTERNOON AND EVENING...WITH AREAS OF MVFR CIGS/VIS UNDER
SOME THE STRONGER STORMS. LARGE HAIL AND ERRATIC WIND GUSTS TO
AROUND 50 KTS WILL BE POSSIBLE NORTH OF A LINE FROM KCOS TO KLHX
TO KSPD. THREAT DIMINISHES AFTER 00Z FOR THE KCOS AND KPUB TAF
SITES. KALS WILL REMAIN DRY TODAY WITH VFR CONDITIONS...WITH
SOUTHWEST WINDS WINDS 15-30 KTS THIS AFTERNOON. MVFR STRATUS WILL
REDEVELOP AT KCOS AND KPUB 11Z-13Z AS MOIST AIR SLOSHES SOUTH ONCE
AGAIN...WITH SCATTERED TSRA MOST LOCATIONS THU AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ224.
&&
$$
UPDATE...PETERSEN
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1119 AM MDT WED MAY 21 2014
.UPDATE...
ISSUED AT 1111 AM MDT WED MAY 21 2014
CURRENT FORECAST/SEVERE THREAT LOOKS ON TRACK...WITH LATEST HRRR
RUNS SUGGESTING CONVECTIVE INITIATION BETWEEN 19Z-20Z. STILL
APPEARS BEST TORNADO/SUPERCELL THREAT WILL BE NORTH NEAR THE
DCVZ INTO NE CO...WITH MORE OF A WIND/HAIL THREAT FARTHER SOUTH
WHERE T/TD SPREADS WILL BE LARGER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 523 AM MDT WED MAY 21 2014
...SEVERE THUNDERSTORMS POSSIBLE NORTHERN PORTIONS OF THE SOUTHEAST
PLAINS...CRITICAL FIRE WEATHER CONDITIONS EXPECTED ACROSS THE SAN
LUIS VALLEY...
UPPER LOW WILL STALL OUT OVER NEVADA TODAY BEFORE DROPPING SOUTHWARD
INTO SOUTHERN CA LATER TONIGHT. SOUTHERLY FLOW AHEAD OF THE SYSTEM
TODAY WILL START TO SHIFT SOME MID/HIGH LEVEL MOISTURE INTO THE
WESTERN MTS TODAY...BUT BY IN LARGE...LOWER LEVELS WILL REMAIN QUITE
DRY. WITH SOUTH TO SOUTHWEST WINDS INCREASING AGAIN ACROSS THE
SOUTHWEST MTS AND SAN LUIS VALLEY...EXPECT A RETURN OF CRITICAL FIRE
WEATHER CONDITIONS FOR THE SAN LUIS VALLEY WHERE FUELS ARE
CRITICALLY DRY. RAPID RATES OF FIRE SPREAD WILL BE POSSIBLE WITH
ANY FIRE STARTS AND CURRENT RED FLAG WARNING STILL LOOKS GOOD.
THERE COULD BE SOME ISOLATED HIGH BASED THUNDERSTORMS ALONG THE
CONTDVD TODAY...BUT THEY WILL BE FEW AND FAR BETWEEN...AND WITH
INVERTED V SOUNDINGS...MORE LIKELY TO PRODUCE GUSTY WINDS THAN MUCH
IN THE WAY OF RAINFALL.
DIFFERENT STORY WILL EXIST TODAY FOR THE SOUTHEAST PLAINS. LOW LEVEL
MOISTURE HAS SPREAD BACK IN WITH CURRENT DEW POINTS IN THE 50S FOR
THE LOWER ARKANSAS RIVER...WITH UPPER 40S FOR CANON CITY...AND EVEN
WOODLAND PARK SEEING LOWER 40 DEW POINTS. SOUTHERN I-25 CORRIDOR IS
STILL QUITE DRY WITH KTAD DEW POINT AT 13 AS OF 09Z. BOUNDARY WILL
CONTINUE TO PUSH SLOWLY SOUTHWARD THIS MORNING WITH STRATUS
EXPANDING ACROSS SOUTHEAST CO IN LIGHT UPSLOPE REGIME ALONG THE
LOWER EASTERN SLOPES OF TELLER/EL PASO COUNTY...THE LOWER WET
MOUNTAINS...AND THE NORTHERN SLOPES OF THE RATON RIDGE. THIS SHOULD
BURN OFF DURING THE LATE MORNING WITH DEW POINTS STAYING IN THE
UPPER 40S/LOWER 50S THROUGH EARLY AFTERNOON ACROSS THE MAJORITY OF
THE SOUTHEAST PLAINS. VORT MAX ACROSS NEW MEXICO WILL MOVE IN THIS
AFTERNOON...AND DRIER AIR WILL BEGIN TO MIX NORTHWARD OFF THE RATON
RIDGE. MAIN FACTOR DETERMINING EXTENT OF SEVERE WEATHER POTENTIAL
WILL BE HOW QUICKLY THESE DEW POINTS MIX OUT. HRRR AND RAP13 DROPS
DEW POINTS INTO THE UPPER 30S FOR THE I-25 CORRIDOR WITH 40S FARTHER
EAST BY 21Z. NAM12 AND LOCAL 4KM WRF KEEPS DEW POINTS IN THE LOWER
50S AT 21Z NORTHEAST OF A LINE FROM KCOS...TO KLHX...TO KSPD. SO
CAPES COULD BE AS LOW AS 500 J/KG ALONG THE I-25 CORRIDOR TO AROUND
1500 J/KG ACROSS KIOWA...BENT...PROWERS COUNTIES IF THE RAP IS
CORRECT. OR THEY COULD BE AROUND 1500+ J/KG IF THE NAM12 IS
CORRECT. EITHER WAY...0-6KM SHEARS WILL BE RUNNING AROUND 40-50
KTS...OR EVEN A LITTLE BETTER IF LOW LEVEL WINDS STAY OUT OF THE
EAST...WHICH WOULD SUPPORT DEVELOPMENT OF SUPERCELL THUNDERSTORMS.
BEST CHANCES FOR SEVERE LOOK TO BE ACROSS NORTHERN SECTIONS OF THE
SOUTHEAST PLAINS...WHERE HIGHER DEW POINTS ARE MORE LIKELY TO STAY
IN THE LONGEST. INITIATION MAY OCCUR ALONG THE NORTHERN SLOPES OF
THE RATON MESA AROUND 1 PM...WITH THUNDERSTORMS SPREADING/DEVELOPING
NORTHWARD ACROSS THE SOUTHEAST PLAINS THROUGH THE AFTERNOON.
MAJORITY OF THE ACTIVITY MOVES OUT OF THE AREA BY 00Z AS VORT MAX
LIFTS NORTHWARD. LARGE HAIL AND DAMAGING WINDS WILL BE THE MOST
LIKELY SEVERE THREAT...ESPECIALLY TO THE NORTH OF THE ARKANSAS
RIVER. IF DEW POINTS CAN STAY HIGH ENOUGH...THUS...LCLS LOW
ENOUGH...THERE COULD BE ENOUGH LOW LEVEL HELICITY FOR AN ISOLATED
TORNADO. THIS WOULD BE MORE LIKELY TO OCCUR ALONG THE PALMER DIVIDE
AND KIOWA COUNTY...BUT THREAT FOR THIS APPEARS ON THE LOWER SIDE OF
THE SPECTRUM AT THIS POINT. POTENTIAL FOR DAMAGING WIND GUSTS WILL
EXTEND FARTHER SOUTHWARD ACROSS THE SOUTHEAST PLAINS THAN HAIL
THREAT DUE TO HIGHER AVAILABLE DOWNDRAFT CAPE. WILL LIKELY PLAY THE
SEVERE THREAT AREA NORTHEAST OF A LINE FROM COLORADO SPRINGS...TO LA
JUNTA...TO TWO BUTTES.
FINAL CONCERN IS FOR POTENTIAL FOR HEAVY RAINFALL ON THE BURN SCARS
THIS AFTERNOON...PARTICULARLY ACROSS WALDO AND BLACK FOREST. WINDOW
FOR GREATEST THREAT WILL BE FROM 2 PM TO 6 PM...PROBABLY CENTERED
MORE IN THE 3 TO 5 PM RANGE FOR WALDO. AGAIN...STRENGTH OF
UPDRAFTS/POTENTIAL RAINFALL EFFICIENCIES WILL DEPEND ON HOW MUCH LOW
LEVEL MOISTURE STAYS IN. HUNCH IS THAT HIGHER TERRAIN WILL MIX OUT
AT LEAST SOME OF THE LOW LEVEL MOISTURE AND LCLS WILL BE UP AROUND
11-12KFT MSL...WHICH WILL ALLOW FOR SOME EVAPORATION BELOW CLOUD
BASE. ALTHOUGH THREAT FOR FLASH FLOOD PRODUCING RAINFALL IS THERE
TODAY...THINK THE THREAT IS BELOW A 40 PERCENT PROBABILITY. MORE
LIKELY SCENARIO IS FOR SOME RAINFALL AMOUNTS GENERALLY IN THE
.10 TO .40 RANGE...WHICH COULD MEAN SOME FLOOD ADVISORY RAINFALL
CAUSING MINOR RUN OFF FOR THE WALDO BURN SCAR. MAJORITY OF THE HIGH
RES MODELS SUGGEST THE LESSER IMPACT SCENARIO...BUT SITUATION WILL
REQUIRE CLOSE MONITORING THROUGH THE AFTERNOON AND EARLY EVENING
HOURS.
THUNDERSTORMS WILL COME TO AN END DURING THE EVENING FOR MOST
AREAS...WITH ANOTHER INTRUSION OF STRATUS TOWARDS MORNING ACROSS
NORTHERN PORTIONS OF THE SOUTHEAST PLAINS. -KT
.AVIATION... MVFR CIGS WILL CONTINUE TO EXPAND ACROSS THE SOUTHEAST
PLAINS THROUGH MORNING...WITH SOME POCKETS OF IFR CIGS ACROSS THE
PIKES PEAK REGION AND ALONG THE LOWER EASTERN SLOPES OF THE
SOUTHEAST MOUNTAINS. COULD EVEN SEE SOME PATCHY FOG. STRATUS
SHOULD ERODE BY 17-18Z FOR MOST AREAS WITH ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING DURING THE EARLY AFTERNOON ACROSS THE
SOUTHEAST MOUNTAINS AND NORTHERN SLOPES OF THE RATON RIDGE. THESE
WILL BE CAPABLE OF PRODUCING VFR TO LOCAL MVFR CIGS/VIS. LARGE HAIL
AND ERRATIC WIND GUSTS TO AROUND 50 KTS WILL BE POSSIBLE NORTH OF A
LINE FROM KCOS THE KLHX TO NORTH OF KSPD. THREAT DIMINISHES AFTER
00Z FOR THE KCOS AND KPUB TAF SITES. KALS WILL REMAIN DRY TODAY
WITH VFR CONDITIONS...THOUGH EXPECT A RETURN OF SOUTHWEST WINDS 15-
30 KTS IN THE AFTERNOON. -KT
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 523 AM MDT WED MAY 21 2014
NOT MANY ADJUSTMENTS NEEDED FOR THE LONGER TERM AS UNSETTLED
PATTERN IS STILL ANTICIPATED WITH LONGER TERM METEOROLOGICAL
ISSUES REMAINING POPS...SEVERE WEATHER THREAT AT TIMES WITH
INITIAL LONGER TERM FOCUS FOR SEVERE WEATHER FROM THURSDAY INTO
THURSDAY NIGHT...LOCALLY HEAVY RAINFALL AND ASSOCIATED BURN SCAR
FLOODING THREAT AND TEMPERATURES.
RECENT LONGER TERM FORECAST MODEL SOUNDINGS AND COMPUTER
SIMULATIONS CONTINUE TO SUGGEST THAT CLOSED UPPER LOW LOCATED
OVER SOUTHERN NEVADA AT 00Z FRIDAY WILL SHIFT INTO THE 4-CORNERS
REGION BY 00Z SUNDAY AND THEN SLOWLY MOVES ACROSS SOUTHERN
COLORADO INTO MONDAY MORNING BEFORE MOVING EAST OF THE FORECAST
DISTRICT BY MONDAY NIGHT/TUESDAY MORNING.
UNSETTLED METEOROLOGICAL CONDITIONS(PRIMARILY IN THE FORM OF
RAIN...HEAVY AT TIMES AS WELL AS STRONG TO SEVERE STORMS AT
TIMES) ARE ANTICIPATED FROM THURSDAY INTO MONDAY. AT THIS
TIME...IT APPEARS THAT THE HIGHEST POTENTIAL FOR SEVERE
THUNDERSTORMS(ESPECIALLY EASTERN SECTIONS) DURING THE LONGER
TERM SHOULD BE REALIZED FROM THURSDAY INTO THURSDAY
NIGHT...ESPECIALLY IF ENOUGH ADEQUATE ATMOSPHERIC MOISTURE
INTERACTS WITH SOMEWHAT FAVORABLE 0 TO 6 KM BULK SHEAR VALUES.
RECENT SPC 2ND DAY OUTLOOK(FOR THURSDAY) HAS A LARGE PORTION OF
EASTERN COLORADO COVERED WITH A SLIGHT RISK OF SEVERE
THUNDERSTORMS.
IN ADDITION...PRECIPITATION...HEAVY AT TIMES(WHICH WILL BE CAPABLE
OF PRODUCING FLOODING CONCERNS/ISSUES AT TIMES...ESPECIALLY OVER
THE AREA BURN SCARS)...IS ANTICIPATED AS THE UPPER SYSTEM IMPACTS
THE FORECAST DISTRICT FROM LATE THIS WEEK INTO EARLY NEXT WEEK. AS
ALWAYS...WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY.
IMPROVING METEOROLOGICAL CONDITIONS SHOULD THEN BY NOTED BY
TUESDAY AS THE CLOSED UPPER LOW IS PROJECTED TO MOVE EAST OF THE
FORECAST DISTRICT. TEMPERATURES ARE STILL EXPECTED TO RUN NEAR
LATE MAY CLIMATOLOGICAL AVERAGES DURING THE LONGER TERM.
&&
.AVIATION... MVFR CIGS WILL CONTINUE TO EXPAND ACROSS THE SOUTHEAST
PLAINS THROUGH MORNING...WITH SOME POCKETS OF IFR CIGS ACROSS THE
PIKES PEAK REGION AND ALONG THE LOWER EASTERN SLOPES OF THE
SOUTHEAST MOUNTAINS. COULD EVEN SEE SOME PATCHY FOG. STRATUS
SHOULD ERODE BY 17-18Z FOR MOST AREAS WITH ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING DURING THE EARLY AFTERNOON ACROSS THE
SOUTHEAST MOUNTAINS AND NORTHERN SLOPES OF THE RATON RIDGE. THESE
WILL BE CAPABLE OF PRODUCING VFR TO LOCAL MVFR CIGS/VIS. LARGE HAIL
AND ERRATIC WIND GUSTS TO AROUND 50 KTS WILL BE POSSIBLE NORTH OF A
LINE FROM KCOS THE KLHX TO NORTH OF KSPD. THREAT DIMINISHES AFTER
00Z FOR THE KCOS AND KPUB TAF SITES. KALS WILL REMAIN DRY TODAY
WITH VFR CONDITIONS...THOUGH EXPECT A RETURN OF SOUTHWEST WINDS 15-
30 KTS IN THE AFTERNOON. -KT
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 523 AM MDT WED MAY 21 2014
NOT MANY ADJUSTMENTS NEEDED FOR THE LONGER TERM AS UNSETTLED
PATTERN IS STILL ANTICIPATED WITH LONGER TERM METEOROLOGICAL
ISSUES REMAINING POPS...SEVERE WEATHER THREAT AT TIMES WITH
INITIAL LONGER TERM FOCUS FOR SEVERE WEATHER FROM THURSDAY INTO
THURSDAY NIGHT...LOCALLY HEAVY RAINFALL AND ASSOCIATED BURN SCAR
FLOODING THREAT AND TEMPERATURES.
RECENT LONGER TERM FORECAST MODEL SOUNDINGS AND COMPUTER
SIMULATIONS CONTINUE TO SUGGEST THAT CLOSED UPPER LOW LOCATED
OVER SOUTHERN NEVADA AT 00Z FRIDAY WILL SHIFT INTO THE 4-CORNERS
REGION BY 00Z SUNDAY AND THEN SLOWLY MOVES ACROSS SOUTHERN
COLORADO INTO MONDAY MORNING BEFORE MOVING EAST OF THE FORECAST
DISTRICT BY MONDAY NIGHT/TUESDAY MORNING.
UNSETTLED METEOROLOGICAL CONDITIONS(PRIMARILY IN THE FORM OF
RAIN...HEAVY AT TIMES AS WELL AS STRONG TO SEVERE STORMS AT
TIMES) ARE ANTICIPATED FROM THURSDAY INTO MONDAY. AT THIS
TIME...IT APPEARS THAT THE HIGHEST POTENTIAL FOR SEVERE
THUNDERSTORMS(ESPECIALLY EASTERN SECTIONS) DURING THE LONGER
TERM SHOULD BE REALIZED FROM THURSDAY INTO THURSDAY
NIGHT...ESPECIALLY IF ENOUGH ADEQUATE ATMOSPHERIC MOISTURE
INTERACTS WITH SOMEWHAT FAVORABLE 0 TO 6 KM BULK SHEAR VALUES.
RECENT SPC 2ND DAY OUTLOOK(FOR THURSDAY) HAS A LARGE PORTION OF
EASTERN COLORADO COVERED WITH A SLIGHT RISK OF SEVERE
THUNDERSTORMS.
IN ADDITION...PRECIPITATION...HEAVY AT TIMES(WHICH WILL BE CAPABLE
OF PRODUCING FLOODING CONCERNS/ISSUES AT TIMES...ESPECIALLY OVER
THE AREA BURN SCARS)...IS ANTICIPATED AS THE UPPER SYSTEM IMPACTS
THE FORECAST DISTRICT FROM LATE THIS WEEK INTO EARLY NEXT WEEK. AS
ALWAYS...WFO PUEBLO WILL CONTINUE TO MONITOR CLOSELY.
IMPROVING METEOROLOGICAL CONDITIONS SHOULD THEN BY NOTED BY
TUESDAY AS THE CLOSED UPPER LOW IS PROJECTED TO MOVE EAST OF THE
FORECAST DISTRICT. TEMPERATURES ARE STILL EXPECTED TO RUN NEAR
LATE MAY CLIMATOLOGICAL AVERAGES DURING THE LONGER TERM.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR COZ224.
&&
$$
UPDATE...PETERSEN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
203 PM CDT WED MAY 21 2014
.DISCUSSION...
1217 PM CDT
CANCELLED DENSE FOG EARLY...AS WELL CONFINING HIGHEST POPS FOR
SHOWERS/THUNDERSTORMS TO SOUTHERN THIRD OF CWA THROUGH THIS
AFTERNOON.
LATEST VISIBLE SATELLITE IMAGERY DEPICTING DENSE FOG WHICH HAD
BEEN SPILLING ONSHORE FOR THE LAST SEVERAL HOURS CONTINUING TO
DIMINISH. WITH THIS DIMINISHING TREND EXPECTED TO CONTINUE...THE
THREAT FOR ANY DENSE FOG OVER THE NEXT SEVERAL HOURS WILL BE OVER
THE LAKE/NEARSHORE AND SO HAVE CANCELLED THE DENSE FOG ADVISORY.
BAGGY SURFACE GRADIENT IN PLACE AS COLD FRONT MAINTAINS A SLOW
SOUTHWARD PROGRESSION THROUGH NORTH CENTRAL ILLINOIS. THIS FRONT
WILL SLOWLY PUSH SOUTH THROUGH THE AFTERNOON WITH MUCH DRIER AIR
FILTERING ON THE BACKSIDE...WITH SURFACE DEWPOINTS IN THE 50S AND
40S ACROSS NORTHWEST ILLINOIS. THIS WILL LIKELY CONFINE THE
AFTERNOON THUNDERSTORM CHANCES TO THE SOUTHERN THIRD OF THE
CWA...MAINLY SOUTH OF A PONTIAC TO VALPARAISO LINE...AS THIS FRONT
SAGS SOUTH THIS AFTERNOON. UPSTREAM MID LEVEL WAVE AND INCREASING
MID LEVEL FLOW TO THE WEST WILL APPROACH OVER THE NEXT COUPLE OF
HOURS. AS THIS OCCURS...WEAK/MODERATE CONVERGENCE ALONG FRONTAL
BOUNDARY/SURFACE TROUGH AXIS SHOULD ALLOW FOR ISOL/SCATTERED
THUNDERSTORM DEVELOPMENT WITH PEAK DEVELOPMENT EXPECTED BY MID
AFTERNOON BEFORE CHANCES DIMINISH INTO THE LATE AFTERNOON WITH
SINKING FRONT. ALTHOUGH BEST OVERALL COVERAGE SHOULD STAY SOUTH
OF THE CWA...A FEW STORMS COULD BECOME STRONG TO SEVERE ACROSS THE
SOUTHERN TIER...ESPECIALLY IN AXIS OF HIGHER
DEWPOINTS/INSTABILITY.
RODRIGUEZ
//PREV DISCUSSION...
323 AM CDT
THE FORECAST CHALLENGES CENTER ON THUNDERSTORM CHANCES TODAY AS WELL
AS THE TEMPERATURES TODAY...PARTICULARLY NEAR LAKE MICHIGAN. AFTER
THAT...THE WEATHER IS QUIESCENT WITH A GRADUAL UNSETTLING DURING THE
LATTER HALF OF THE HOLIDAY WEEKEND INTO THE FIRST HALF OF NEXT WEEK.
TODAY...
A SURFACE COOL FRONT HAS BECOME STATIONARY AND DIFFUSE ACROSS
SOUTHEAST WI...TO NEAR LASALLE/PERU...THROUGH NORTHERN MO EARLY THIS
MORNING. THIS LIKELY WILL GET NUDGED SOUTHWARD BY OUTFLOWS FROM
ISOLATED EARLY MORNING CONVECTION. A SECONDARY STRONGER COLD FRONT
WITH PRESSURE RISES ANALYZED BEHIND IT IS MOVING INTO WESTERN WI
AND NORTHERN IA EARLY THIS MORNING AND WILL OVERTAKE THE ORIGINAL
BOUNDARY AS IT MOVES THROUGH THE FORECAST AREA THIS AFTERNOON.
WITH THE WEAK WINDS AHEAD OF THIS FEATURE...LAKE-COOLED AIR AS WELL
AS POSSIBLY FOG/STRATUS MAY ADVECT INTO PORTIONS OF THE ILLINOIS
SHORE...INCLUDING DOWNTOWN CHICAGO THIS MORNING. THIS IS
CHALLENGING GIVEN LIMITED OBSERVATIONAL DATA OVER THE LAKE...BUT
THERE HAVE BEEN A HANDFUL REPORTS/OBSERVATIONS OF FOG NORTHWARD ON
THE LAKE. WILL INCLUDE AT LEAST THE MENTION OF FOG THIS MORNING
ALONG THE SHORELINE WITH THE CONTINUED HIGH DEW POINT AIR AND SOME
ONSHORE COMPONENT. IF THAT FOG/STRATUS DOES OCCUR TEMPERATURES
WILL LIKELY HOLD STEADY NEAR THE LAKE BEFORE WARMING IN THE
AFTERNOON. HAVE INITIALLY FORECAST MID/UPPER 70S NEAR THE LAKE
SHORE OF ILLINOIS AND INDIANA...BUT CONFIDENCE ON THIS IS LOW.
OTHERWISE...GIVEN THE WARM STARTING POINT AND THINNING CONVECTIVE
DEBRIS BY LATE THIS MORNING...CWA LOCATIONS AWAY FROM THE LAKE
SHOULD WARM INTO MID 80S SUCH AS YESTERDAY.
AS MIXING ENSUES TODAY...CONVERGENCE IS EXPECTED TO DEVELOP ACROSS
THE SOUTHEAST FORECAST AREA AND THAT IS WHERE THE BETTER CHANCE FOR
SCATTERED STORMS THIS AFTERNOON IS. AS THE MAIN FRONT CATCHES UP
MID-LATE AFTERNOON...MORE ROBUST CONVECTION IS ANTICIPATED TO
DEVELOP JUST SOUTHEAST OF THE FORECAST AREA. IT CANNOT BE RULED
OUT THAT AN ISOLATED STORM OR TWO DEVELOP FURTHER NORTH THIS
AFTERNOON...INCLUDING THE CHICAGO METRO AREA...AS THE PRIMARY
FRONT MOVES INTO A HIGH PWAT/MODESTLY UNSTABLE ATMOSPHERE. NOT
ENOUGH CONFIDENCE TO MENTION IN THE FORECAST AT THIS TIME. FOR THE
SOUTHEAST FORECAST AREA THIS AFTERNOON...DEEP LAYER SHEAR AND
CONTINUED MODEST TO STRONG INSTABILITY WOULD SUPPORT A CONDITIONAL
THREAT FOR DISCRETE SEVERE STORMS INITIALLY CAPABLE OF MAINLY
LARGE HAIL IF THEY CAN DEVELOP BEFORE THE BEST CONVERGENCE CLEARS
THE FORECAST AREA. RIGHT NOW INITIATION IS EXPECTED BETWEEN 1-4 PM
AND THESE STORMS LIKELY MOVING OUT OF THE FORECAST AREA BY 4-7 PM.
THURSDAY THROUGH SATURDAY...
AN UPPER CLOSED LOW ACROSS THE SOUTHWEST CONUS THIS MORNING WILL
MOVE VERY LITTLE THROUGH THE NEXT FEW DAYS. IN RESPONSE TO
THIS...UPSTREAM RIDGING ACROSS THE PLAINS IS FORECAST...AND BEING
UNDER THE ANTICYCLONIC SIDE OF THE JET FOR THESE FEW DAYS IT LOOKS
QUIET. WHILE THERE MAY BE SOME HIGH CLOUDS OVERALL IT LOOKS
MOSTLY CLEAR IN MANY AREAS. THE SURFACE PATTERN OF A HIGH CENTER
IN THE WESTERN GREAT LAKES SUPPORTS ONSHORE FLOW. LOCAL
CLIMATOLOGICAL RESEARCH WITH ONSHORE FLOW FOR LATE MAY SUPPORTS
AROUND A 10-12 DEGREE TEMPERATURE DIFFERENCE FROM DOWNTOWN TO
OUTLYING SUBURBS WITH ALL DAY ONSHORE FLOW AND HAVE STUCK CLOSE TO
THAT. TEMPERATURES LOOK TO BE NEAR/SLIGHTLY BELOW NORMAL.
SUNDAY THROUGH TUESDAY...
THE CLOSED UPPER LOW IS FORECAST TO MOVE EAST DURING THIS TIME AND
GRADUALLY WEAKEN AS IT IS CUT OFF FROM THE MAIN JET.
HOWEVER...HEIGHT FALLS FROM THIS FEATURE ARE EXPECTED TO INCH
THEIR WAY OVER THE AREA DURING THIS TIME. WITH A DESTABILIZING
LOWER ATMOSPHERE...THUNDER CHANCES SLOWLY INCREASE...BUT MAINLY
WEST AND NORTH OF THE REGION THROUGH THE HOLIDAY. CONTINUE SMALL
CHANCES WITHIN THE FORECAST...WHICH WOULD BE MAINLY ASSOCIATED
WITH ELEVATED WARM AIR ADVECTION/POSSIBLE SHORT WAVE IMPULSES. SO
CONFIDENCE IS PRETTY LOW ON STORMS OCCURRING AT THIS TIME. THE
850MB TEMPERATURES AND LOW-LEVEL TRAJECTORIES SUPPORT MID 80S ON
THE HOLIDAY AND POTENTIALLY TUESDAY AS WELL...IF INDEED CONVECTION
AND ITS DEBRIS STAYS MAINLY WEST AND NORTH.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LGT/VRBL WINDS RETURNING TO NWLY BY EARLY AFTERNOON WITH
DAYTIME WARMING/MIXING.
* LAKE BREEZE MOVING INLAND BY LATE MORNING/EARLY AFTERNOON
SHIFTING WINDS TO NELY.
KREIN
//DISCUSSION...UPDATED 18Z...
A LAKE ENHANCED FRONT HAS PUSHED PUSHED WELL INLAND AND IS
DISSIPATING WITH DAYTIME DAYTIME WARMING/MIXING...WITH WINDS
RETURNING TO SYNOPTICALLY NWLY. GYY WILL BE THE ONLY SITE
MAINTAINING SOME LAKE INFLUENCE...BUT LATEST VIS SATELLITE IMAGERY
INDICATES THAT THE FOG IS REMAINING OFF SHORE WHILE THINNING...SO
EVEN THERE...CONDITIONS SHOULD SOON RETURN TO VFR. CONDITIONS WILL
BE QUIET FOR THE REMAINDER OF THE EVENING AND OVERNIGHT AS HIGH
PRESSURE SPREADS ACROSS THE MIDDLE AND UPPER MISSISSIPPI VALLEY.
THE MAIN ISSUE FOR TOMORROW WILL BE A WIND SHIFT ASSOCIATED WITH
LAKE BREEZE DEVELOPMENT. WITH THE HIGH SPREADING OVER THE WESTERN
GREAT LAKES REGION...THE SFC PRESSURE GRADIENT WILL BE VERY
WEAK...SO LAKE BREEZE DEVELOPMENT IS LIKELY...TURNING WINDS NLY AT
GYY AND NELY AT ORD/MDW. TIMING WILL BE THE MAIN QUESTION...THOUGH
THE LATEST HIGH RESOLUTION GUIDANCE SUGGESTS THAT MDW/GYY SHOULD
TURN BY LATE MORNING AND ORD BY EARLY AFTERNOON. DPA/RFD WILL
LIKELY REMAIN UNAFFECTED WITH WINDS REMAINING NWLY AT LESS THAN 10
KT. NO CIG/VIS RESTRICTIONS ARE EXPECTED THROUGH THE PERIOD.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN WIND TRENDS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY...VFR. EARLY LAKE BREEZE WIND SHIFT TO NORTHEAST LIKELY.
SATURDAY...VFR. EAST NORTHEAST WINDS.
SUNDAY...VFR.
MONDAY...PRIMARILY VFR. SLIGHT CHANCE TSRA.
TUESDAY...VFR.
RC
&&
.MARINE...
202 PM CDT
A FAIRLY BROAD AREA OF LOW PRESSURE IS POSITIONED OVER THE WESTERN
GREAT LAKES AND WILL MOVE EASTWARD TONIGHT AND THURSDAY. A COLD
FRONTAL BOUNDARY WILL MOVE ACROSS THE LAKE THIS EVENING WHICH WILL
BRING A STEADIER NORTHWEST WIND AS WELL AS DRIER AIR...WHICH WILL
WORK TO ERODE THE REMAINING FOG ACROSS THE OPEN WATERS LATE THIS
AFTERNOON AND EARLY THIS EVENING. GENERALLY LIGHT NORTHERLY FLOW
WILL REMAIN ACROSS THE LAKE INTO THE WEEKEND AS HIGH PRESSURE MOVES
OVER LAKE MICHIGAN. A SHIFT TO ONSHORE WINDS IS LIKELY THURSDAY AND
FRIDAY...WITH MORE VARIABILITY SATURDAY AS THE HIGH MOVES OVERHEAD.
A SHIFT TO A STEADIER SOUTHERLY WIND IS EXPECTED SATURDAY NIGHT AS
THE HIGH MOVES OFF TO THE EAST. LOW PRESSURE IS FORECAST TO TRACK
NORTHEAST ACROSS THE UPPER MIDWEST SUNDAY NIGHT AND MONDAY WHICH
WILL TIGHTEN THE PRESSURE GRADIENT LEADING TO A BIT OF AN INCREASE
IN WIND SPEEDS BUT STABLE AIR OVER THE LAKE SHOULD KEEP GUST
FREQUENCY LOW.
MDB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-
LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ743-LMZ744-
LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-
LMZ878 UNTIL 3 PM WEDNESDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
158 PM CDT Wed May 21 2014
.DISCUSSION...
ISSUED 158 PM CDT Wed May 21 2014
Severe storm potential will highlight the short term. A brief period
of cooler temps will close out the week, before a long wave ridge
builds into our area for the weekend. As that ridge slides east
later this weekend, a few late afternoon thunderstorms could bubble
up in our western areas on Sunday and Memorial Day as moisture
and heat return to IL.
SHORT TERM...Tonight through Saturday.
The initial severe thunderstorm watch #164 does not include any of
IL, but we still expect some thunderstorms to develop along the
cold front in IL later this afternoon. At 18z/1 pm, the front
extended on a line through Bloomington and Rushville. Surface
dewpoints ahead of the front had climbed into the mid 60s, with
air temps in the mid to upper 80s. Surface based CAPEs were in the
2800-3300 J/kg, with 0-6km wind shear of 35-50kts. LAPS soundings
were indicating little to no cap above the LCL. We should see some
of the storms become strong in our area, with very large hail the
main hazard and damaging winds possible. Supercell formation
appears likely at the onset, with the better chances of linear
progression most likely occurring after the storms advance eastward
into Indiana. The cumulus field on across C IL appears to be
deepening, with some towering cu. A watch may be needed in IL in
the 2-3 pm time frame.
Will maintain high chance PoPs the rest of the afternoon and into
the evening, as coverage could be limited by breaks in the line of
storm cells that develop.
The latest 4km model HRRR output shows rather limited coverage of
storms on an E-W line along and south of I-72, with storms
generally south of our CWA by 06z/1am. Will keep PoPs after
midnight limited to the far southern areas.
The cold front forward progress will slow down and stall near the
southern tip of IL, keeping shower and storm chances close by to
the south and west of our forecast area. We held onto a narrow
area of slight chance PoPs along our far southern counties on
Thurs and Thur night as a result.
Surface high pressure and a building ridge aloft should help keep
our area rain free on Friday and Saturday as moisture return will
be primarily into the Missouri and areas west.
A brief cooler period will occur from Thursday into Friday behind
today`s cold front. Highs will still linger right around normal in
the mid to upper 70s. Saturday will see temps begin a warming
trend, but highs will still remain mainly in the upper 70s.
LONG TERM...Sunday through Wednesday.
Warming through a deeper layer will develop on Sunday as the
surface ridge axis slides east of Illinois and southerly return
flow increases. Low and mid level moisture content will increase as
well, with dewpoints returning to the 60s west of I-55 on Sunday.
Thunderstorm chances will be mainly west of our forecast area, in
the vicinity of a surface trough along the Mississippi river
valley. Instability params support storm progression into western
IL, so we went with low chance and slight chance PoPs west of
I-55. A weakening of the surface trough and increasing cap
strength on Memorial Day may help to diminish storm chances a
little. However, an weak disturbance in the 400-600 mb layer
could cause a few isolated storms. We went with slight chance PoPs
NW of a line from Springfield to Champaign, for mainly late
afternoon/early evening storm potential. Most areas should remain
dry though. Memorial Day looks to be the warmest day of the
holiday weekend, as highs return to the mid 80s. Dewpoints in the
low to mid 60s will make it feel a bit humid outside as well.
On Tuesday and Wednesday, the ECMWF, and to some extent the GFS,
progress an upper low into the ridge, triggering a wider coverage
of showers and storms. Low chance PoPs were included for all our
counties Tuesday and Wednesday to account for the relative
agreement on a wetter solution. Increasing clouds and rain
potential should keep high temps in the 70s both days.
Shimon
&&
.AVIATION...
ISSUED 1247 PM CDT Wed May 21 2014
A frontal boundary will sag south into central IL this afternoon
and evening. Some isolated to scatted storm are expected to
develop this afternoon along and ahead of the front, though
coverage is expected to be too low to include in TAFS beyond VCTS.
If a terminal is impacted by TSRA, short reduction to IFR
possible with brief strong/gusty winds. Otherwise VFR expected
through Thu AM with diurnal cumulus this afternoon and scattered
mid clouds overnight. W/SW winds ahead of the front will veer to
the north this evening after the frontal passage, generally
remaining under 10 kts.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
425 PM EDT WED MAY 21 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 316 PM EDT WED MAY 21 2014
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT BRINGING A CHANCE
FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL THEN BUILD IN AND
PROVIDE DRY CONDITIONS THROUGH MONDAY. AN UPPER LEVEL SYSTEM COULD
BRING SOME RAIN AGAIN TUESDAY INTO WEDNESDAY OF NEXT WEEK. FOR THE
MOST PART NEAR TO ABOVE AVERAGE TEMPERATURES CAN BE EXPECTED.
&&
.NEAR TERM /REST OF THIS AFTERNOON AND TONIGHT/...
ISSUED AT 316 PM EDT WED MAY 21 2014
SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON
AHEAD OF AN UPPER WAVE. ATMOSPHERE CONTINUES TO BE FAVORABLE FOR
SEVERE WEATHER SO EXPECT SOME SEVERE STORMS WITH LARGE HAIL AND
DAMAGING WINDS LATE THIS AFTERNOON INTO EARLY EVENING.
BASED ON CURRENT DEVELOPMENT AND RAPID UPDATE MODELS...SOUTHEASTERN
FORECAST AREA LOOKS TO HAVE THE MOST COVERAGE LATER THIS AFTERNOON.
COLD FRONT IS STILL TO THE NORTHWEST...AND AS IT SLIDES DOWN THIS
EVENING AND TONIGHT ADDITIONAL STORMS ARE STILL POSSIBLE. WILL KEEP
CHANCE POPS THIS EVENING ALL AREAS AND THEN DECREASE THEM FROM NORTH
TO SOUTH AS THE NIGHT PROGRESSES /AND COLD FRONT SLIDES SOUTH/.
FOR TEMPERATURES STUCK WITH A MODEL BLEND.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 316 PM EDT WED MAY 21 2014
FOCUS IS ON ANY CHANCES FOR RAIN EARLY OTHERWISE ON TEMPERATURES.
MODELS ARE CLOSE ENOUGH THAT A BLEND CAN BE USED.
REAL PUSH OF COLDER AIR MOVES IN LATER DURING THE DAY ON THURSDAY
INTO THURSDAY EVENING. SOME MODELS TRY TO DEVELOP RAIN ACROSS THE
SOUTHWEST FORECAST AREA THURSDAY NIGHT AS A WAVE MOVES THROUGH NEAR
THE BOUNDARY...BUT BELIEVE THEY ARE OVERDOING IT AS SREF AND GFS
ENSEMBLES ARE DRY. WILL KEEP FORECAST DRY.
OTHERWISE HIGH PRESSURE WILL KEEP DRY CONDITIONS THROUGH THE SHORT
TERM. COLDER AIR MOVES IN BRIEFLY ON FRIDAY WITH A LITTLE BELOW
AVERAGE TEMPERATURES...BUT TEMPERATURE BEGIN REBOUNDING ON SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 316 PM EDT WED MAY 21 2014
MODELS ARE CLOSE ENOUGH THAT THE ALLBLEND INITIALIZATION CAN BE
USED.
HIGH PRESSURE AND UPPER RIDGE WILL KEEP DRY AND WARM CONDITIONS
THROUGH MONDAY. AN UPPER TROUGH TO THE WEST COULD BRING SOME SHOWERS
AND ISOLATED STORMS TUESDAY AND WEDNESDAY. TEMPERATURES WILL COOL
DOWN AGAIN ON WEDNESDAY.
&&
.AVIATION /DISCUSSION FOR THE 212100Z KIND TAF UPDATE/...
ISSUED AT 425 PM EDT WED MAY 21 2014
BROKEN LINE OF CONVECTION CURRENTLY EXTENDS FROM CENTRAL INDIANA
BACK INTO ILLINOIS NEAR A SURFACE BOUNDARY. SOME CONVECTION ALSO
DEVELOPING AHEAD OF AN UPPER WAVE PUSHING TOWARDS SOUTHWEST
ILLINOIS. SHORT TERM MODEL DATA SUGGEST THIS UPPER WAVE WILL BE
PASSING OVER THE KIND VICINITY TOWARDS 220100Z-220200Z...SO THINK
THE THREAT FOR CONVECTION WILL REMAIN HIGH UNTIL THAT TIME. WILL
EXTEND THE THUNDERSTORM THREAT IN TIME A FEW MORE HOURS ON THE
UPDATE. VARIABLE AND GUSTY SURFACE WIND AND HAIL ARE POSSIBLE WITH
THE HEAVIER CELLS.
PREVIOUS DISCUSSION FOLLOWS.
MAINLY VFR CONDITIONS EXPECTED THIS FORECAST PERIOD...HOWEVER
BRIEF MVFR OR IFR CONDITIONS WILL BE POSSIBLE WITH ANY TSRA
DEVELOPMENT LATE THIS AFTERNOON.
SURFACE AND RADAR ANALYSIS REVEALS A SURFACE BOUNDARY JUST NORTH
OF LAF AND MIE...AND SCT RWS AND TSRAS WERE DEVELOPING ALONG THE
BOUNDARY. HRRR SUGGESTS FURTHER CONVECTIVE DEVELOPMENT THIS
AFTERNOON WITH SOUTHWARD PROPAGATION ACROSS THE TAF SITES THROUGH
THE AFTERNOON. GIVEN THE FAVORABLE CONVECTIVE INSTABILITY HAVE
INCLUDED A TEMPO PERIOD FOR TSRA DURING THE LATE AFTERNOON EARLY
EVE AT THE TAF SITES.
HIGH DEW POINTS ARE EXPECTED TO LINGER THROUGH THE OVERNIGHT. THIS
COMBINED WITH RECENT RAIN AND LIGHT WINDS MAY RESULT IN SOME MVFR
FOG LATE TONIGHT. ANY FOG DEVELOPMENT WILL QUICKLY DISSIPATE AFTER
14Z THURSDAY AS DAYTIME HEATING RESUMES.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....JP/50
AVIATION...JP/JAS
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
316 PM EDT WED MAY 21 2014
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM...AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 316 PM EDT WED MAY 21 2014
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT BRINGING A CHANCE
FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL THEN BUILD IN AND
PROVIDE DRY CONDITIONS THROUGH MONDAY. AN UPPER LEVEL SYSTEM COULD
BRING SOME RAIN AGAIN TUESDAY INTO WEDNESDAY OF NEXT WEEK. FOR THE
MOST PART NEAR TO ABOVE AVERAGE TEMPERATURES CAN BE EXPECTED.
&&
.NEAR TERM /REST OF THIS AFTERNOON AND TONIGHT/...
ISSUED AT 316 PM EDT WED MAY 21 2014
SCATTERED THUNDERSTORMS WILL CONTINUE TO DEVELOP THIS AFTERNOON
AHEAD OF AN UPPER WAVE. ATMOSPHERE CONTINUES TO BE FAVORABLE FOR
SEVERE WEATHER SO EXPECT SOME SEVERE STORMS WITH LARGE HAIL AND
DAMAGING WINDS LATE THIS AFTERNOON INTO EARLY EVENING.
BASED ON CURRENT DEVELOPMENT AND RAPID UPDATE MODELS...SOUTHEASTERN
FORECAST AREA LOOKS TO HAVE THE MOST COVERAGE LATER THIS AFTERNOON.
COLD FRONT IS STILL TO THE NORTHWEST...AND AS IT SLIDES DOWN THIS
EVENING AND TONIGHT ADDITIONAL STORMS ARE STILL POSSIBLE. WILL KEEP
CHANCE POPS THIS EVENING ALL AREAS AND THEN DECREASE THEM FROM NORTH
TO SOUTH AS THE NIGHT PROGRESSES /AND COLD FRONT SLIDES SOUTH/.
FOR TEMPERATURES STUCK WITH A MODEL BLEND.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 316 PM EDT WED MAY 21 2014
FOCUS IS ON ANY CHANCES FOR RAIN EARLY OTHERWISE ON TEMPERATURES.
MODELS ARE CLOSE ENOUGH THAT A BLEND CAN BE USED.
REAL PUSH OF COLDER AIR MOVES IN LATER DURING THE DAY ON THURSDAY
INTO THURSDAY EVENING. SOME MODELS TRY TO DEVELOP RAIN ACROSS THE
SOUTHWEST FORECAST AREA THURSDAY NIGHT AS A WAVE MOVES THROUGH NEAR
THE BOUNDARY...BUT BELIEVE THEY ARE OVERDOING IT AS SREF AND GFS
ENSEMBLES ARE DRY. WILL KEEP FORECAST DRY.
OTHERWISE HIGH PRESSURE WILL KEEP DRY CONDITIONS THROUGH THE SHORT
TERM. COLDER AIR MOVES IN BRIEFLY ON FRIDAY WITH A LITTLE BELOW
AVERAGE TEMPERATURES...BUT TEMPERATURE BEGIN REBOUNDING ON SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 316 PM EDT WED MAY 21 2014
MODELS ARE CLOSE ENOUGH THAT THE ALLBLEND INITIALIZATION CAN BE
USED.
HIGH PRESSURE AND UPPER RIDGE WILL KEEP DRY AND WARM CONDITIONS
THROUGH MONDAY. AN UPPER TROUGH TO THE WEST COULD BRING SOME SHOWERS
AND ISOLATED STORMS TUESDAY AND WEDNESDAY. TEMPERATURES WILL COOL
DOWN AGAIN ON WEDNESDAY.
&&
.AVIATION /DISCUSSION FOR THE 211800Z TAFS/...
ISSUED AT 1234 PM EDT WED MAY 21 2014
MAINLY VFR CONDITIONS EXPECTED THIS FORECAST PERIOD...HOWEVER
BRIEF MVFR OR IFR CONDITIONS WILL BE POSSIBLE WITH ANY TSRA
DEVELOPMENT LATE THIS AFTERNOON.
SURFACE AND RADAR ANALYSIS REVEALS A SURFACE BOUNDARY JUST NORTH
OF LAF AND MIE...AND SCT RWS AND TSRAS WERE DEVELOPING ALONG THE
BOUNDARY. HRRR SUGGESTS FURTHER CONVECTIVE DEVELOPMENT THIS
AFTERNOON WITH SOUTHWARD PROPAGATION ACROSS THE TAF SITES THROUGH
THE AFTERNOON. GIVEN THE FAVORABLE CONVECTIVE INSTABILITY HAVE
INCLUDED A TEMPO PERIOD FOR TSRA DURING THE LATE AFTERNOON EARLY
EVE AT THE TAF SITES.
HIGH DEW POINTS ARE EXPECTED TO LINGER THROUGH THE OVERNIGHT. THIS
COMBINED WITH RECENT RAIN AND LIGHT WINDS MAY RESULT IN SOME MVFR
FOG LATE TONIGHT. ANY FOG DEVELOPMENT WILL QUICKLY DISSIPATE AFTER
14Z THURSDAY AS DAYTIME HEATING RESUMES.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....JP/50
AVIATION...JP
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1251 PM EDT WED MAY 21 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 325 AM EDT WED MAY 21 2014
SCATTERED SHOWERS AND SEVERE THUNDERSTORMS WILL BE POSSIBLE TODAY
AND THIS EVENING AS A COLD FRONT SLIDES ACROSS CENTRAL INDIANA.
TEMPS WILL DECREASE A BIT DURING THE SHORT TERM PERIOD IN THE WAKE
OF COLD FRONT...BUT CONDITIONS WILL BE DRY THROUGH NEXT TUESDAY
WITH HIGH PRESSURE OVER THE AREA. THE NEXT CHANCE FOR SHOWERS AND
THUNDERSTORMS WILL BE NEXT TUESDAY NIGHT/WEDNESDAY WHEN THE NEXT
UPPER LOW AND VORT MAX ENTER THE REGION.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 950 AM EDT WED MAY 21 2014
FORECAST IS PRETTY MUCH ON TRACK. LOWERED POPS THIS MORNING ACROSS
THE SOUTHWEST FORECAST AREA SINCE THUNDERSTORMS SHOULD BE CLOSER TO
THE BOUNDARY ACROSS NORTHERN INDIANA. LEFT POPS ALONE THIS
AFTERNOON. STORM PREDICTION CENTER STILL INDICATES A RISK FOR SEVERE
STORMS WITH LARGE HAIL AND DAMAGING WINDS THE PRIMARY THREATS.
LEFT TEMPERATURES ALONE FOR NOW AND WILL SEE IF CONVECTION OR CLOUDS
FROM CONVECTION REQUIRE A CHANGE LATER THIS AFTERNOON.
PREVIOUS DISCUSSION FOLLOWS...
THE MAIN FOCUS OF THE NEAR TERM IS THE THREAT FOR SEVERE WEATHER.
SPC CONTINUES TO KEEP ALL OF CENTRAL INDIANA UNDER A SLIGHT RISK
FOR DAY 1.
RIDGE ALOFT WILL BREAK DOWN AS UPPER LEVEL LOW ENTERS THE GREAT
LAKES REGION TODAY. MEANWHILE...A COLD FRONT AT THE SURFACE WILL
TRACK ACROSS CENTRAL INDIANA...TRIGGERING SHOWERS AND
THUNDERSTORMS ALONG AND AHEAD OF IT. MLCAPES REMAIN IMPRESSIVE
ACROSS THE FORECAST AREA IN THE 2000 TO 3000 J/KG RANGE. MID LEVEL
LAPSE RATES WILL APPROACH THE 7C MARK BY THIS EVENING. THIS MEANS
THE SOUTH/SOUTHEASTERN PORTIONS OF FORECAST AREA WILL HAVE HIGHEST
THREAT FOR SEVERE DEVELOPMENT WITH BEST INSTABILITY OF THE DAY.
LARGE HAIL WILL BE A HUGE THREAT. IN ADDITION...STRONG WESTERLY SPEED
SHEAR WILL BE CONDUCIVE TO DAMAGING WINDS. HIGHLIGHTED THE
SOUTHEAST QUADRANT OF FORECAST AREA BY CARRYING LIKELY POPS DURING
THIS AFTERNOON AND EVENING. LATEST MODELS HAVE COLD FRONT ENTERING
THE NORTHWESTERN COUNTIES AROUND WED 18Z AND ARE TRENDING TOWARD A
VERY SLOW PROGRESSION OF THE FRONT THROUGH THE DAY.
TEMPS...TRENDED SLIGHTLY ABOVE GUIDANCE FOR TODAY. WARM
SOUTHWESTERLY FLOW AHEAD OF COLD FRONT SHOULD RESULT IN HIGH TEMPS
TOPPING OFF IN THE LOW TO MID 80S.
CURRENTLY...TEMPS ACROSS THE AREA ARE GENERALLY IN THE UPPER 70S
WITH DEWPOINTS IN THE UPPER 50S/LOW 60S. WINDS ARE SOUTHWESTERLY
AT 5 TO 10 MPH AND GUSTING TO 18 MPH.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
ISSUED AT 325 AM EDT WED MAY 21 2014
HELD ONTO WIDESPREAD PRECIP CHANCES UP TO THU 06Z ACROSS MOST OF
FORECAST AREA DUE TO THE SLOW PROGRESSION OF COLD FRONT AND
LINGERING MOISTURE/ISENTROPIC LIFT. ANTICIPATE QUICK CLEARING
AFTER THAT AND THEN A DRY FORECAST THROUGH THE REMAINDER OF SHORT
TERM PERIOD AS HIGH PRESSURE BUILDS BACK INTO THE REGION.
STUCK CLOSE TO GUIDANCE IN REGARD TO TEMPS FOR DURATION OF SHORT
TERM PERIOD. TEMPS BECOME CLOSER TO NORMAL IN WAKE OF
AFOREMENTIONED COLD FRONT...AND MODELS SEEM TO BE PICKING UP ON
THE TRANSITION WELL. HIGHS WILL GENERALLY BE IN THE LOW 70S OVER
THE NORTHERN COUNTIES...TO MID TO UPPER 70S ACROSS THE SOUTHERN
COUNTIES. OVERNIGHT LOWS WILL DIP BACK INTO THE 50S.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 237 PM EDT TUE MAY 20 2014
MAIN FOCUS ON THE EXTENDED WILL BE ON TEMPERATURES AS MEMORIAL
DAY WEEKEND IS LOOKING VERY PROMISING FOR OUTDOOR ACTIVITIES
ACROSS CENTRAL INDIANA.
THE MOST CONSISTENT ECMWF AND ECMWF ENSEMBLE MEANS ALONG WITH THE
00Z GFS START THE EXTENDED OFF WITH BROAD SURFACE HIGH PRESSURE
ACROSS THE GREAT LAKES AND OHIO VALLEY AND A SHARP UPPER RIDGE
ACROSS THE MISSISSIPPI VALLEY. THE SURFACE HIGH WILL SHIFT EAST TO
THE APPALACHIANS SATURDAY NIGHT AND TO THE EASTERN SEABOARD SUNDAY.
THIS WILL ALLOW FOR A MODEST SOUTHERLY FLOW OF WARMER AIR INTO THE
THE OHIO VALLEY THROUGH NEXT WEEK.
EXPECT THE WEEKEND TO BE DRY WITH A FEW THUNDERSTORMS POSSIBLE EARLY
NEXT WEEK WITH LOW LEVEL MOISTURE INCREASING AND IMPULSES ROUNDING
THE BASE OF AN UPSTREAM UPPER LOW ACROSS THE CENTRAL PLAINS. FOR
NOW...WILL KEEP MEMORIAL DAY DRY AND GO WITH SMALL THUNDERSTORM
CHANCES BY TUESDAY.
REGIONAL ALLBLEND TEMPERATURES LOOK REASONABLE GIVEN THE SOUTHERLY
FLOW AND UPPER RIDGE PATTERN WITH AFTERNOON HIGHS STARTING OFF NEAR
NORMAL IN THE 70S ON SATURDAY AND CLIMBING TO THE MID 80S BY MONDAY.
&&
.AVIATION /DISCUSSION FOR THE 211800Z TAFS/...
ISSUED AT 1234 PM EDT WED MAY 21 2014
MAINLY VFR CONDITIONS EXPECTED THIS FORECAST PERIOD...HOWEVER
BRIEF MVFR OR IFR CONDITIONS WILL BE POSSIBLE WITH ANY TSRA
DEVELOPMENT LATE THIS AFTERNOON.
SURFACE AND RADAR ANALYSIS REVEALS A SURFACE BOUNDARY JUST NORTH
OF LAF AND MIE...AND SCT RWS AND TSRAS WERE DEVELOPING ALONG THE
BOUNDARY. HRRR SUGGESTS FURTHER CONVECTIVE DEVELOPMENT THIS
AFTERNOON WITH SOUTHWARD PROPAGATION ACROSS THE TAF SITES THROUGH
THE AFTERNOON. GIVEN THE FAVORABLE CONVECTIVE INSTABILITY HAVE
INCLUDED A TEMPO PERIOD FOR TSRA DURING THE LATE AFTERNOON EARLY
EVE AT THE TAF SITES.
HIGH DEW POINTS ARE EXPECTED TO LINGER THROUGH THE OVERNIGHT. THIS
COMBINED WITH RECENT RAIN AND LIGHT WINDS MAY RESULT IN SOME MVFR
FOG LATE TONIGHT. ANY FOG DEVELOPMENT WILL QUICKLY DISSIPATE AFTER
14Z THURSDAY AS DAYTIME HEATING RESUMES.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...TDUD/50
SHORT TERM...TDUD
LONG TERM....MK
AVIATION...JP
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1247 PM CDT WED MAY 21 2014
.SYNOPSIS...
ISSUED AT 330 AM CDT WED MAY 21 2014
06Z SFC ANALYSIS HAS A FRONT FROM NORTHEAST ILLINOIS INTO
NORTHEAST KANSAS. SEVERAL LOWS WERE ALONG THE FRONT FROM NORTHEAST
KANSAS INTO SOUTHEAST IOWA. A STRONGER COLD FRONT RAN FROM WESTERN
LAKE SUPERIOR INTO NORTHERN KANSAS. DEW POINTS WERE IN THE 60S
FROM THE DEEP SOUTH INTO THE WESTERN GREAT LAKES WITH 40S AND 50S
FROM THE NORTHERN PLAINS INTO THE UPPER MIDWEST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT WED MAY 21 2014
WEAK LOW PRESSURE MOVING ALONG THE FRONT HELPED INITIATE NEW
STORMS ACROSS THE CENTRAL PARTS OF THE AREA. ALTHOUGH NOT SLOW
MOVING...THESE STORMS PRODUCED COPIOUS AMOUNTS OF RAINFALL IN A
VERY SHORT TIME PERIOD.
TRENDS FROM THE RAP INDICATE THE CURRENT STORMS ACROSS THE AREA
WILL CONTINUE TO MOVE EAST IN A NARROW BAND AND SLOWLY DISSIPATE
THROUGH SUNRISE AS THE OVERALL FORCING WEAKENS.
MUCH OF THE MORNING AND AFTERNOON HOURS ARE EXPECTED TO REMAIN DRY
UNTIL ANOTHER ROUND OF FORCING ARRIVES DURING PEAK HEATING. NEW
STORMS SHOULD THEN DEVELOP ACROSS THE FAR SOUTH CLOSE TO THE
FRONTAL BOUNDARY.
TONIGHT...THE AFTERNOON STORMS THAT DEVELOP WILL CONTINUE ACROSS
THE FAR SOUTH DURING THE EVENING BEFORE DISSIPATING. BOUNDARIES
FROM THIS CONVECTION ALONG WITH THE COLD FRONT WILL ALLOW A NEW
NOCTURNAL THUNDERSTORM COMPLEX TO DEVELOP IN NORTHWEST MISSOURI
AND THEN MOVE GENERALLY EAST SOUTHEAST THROUGH SUNRISE THURSDAY.
THE AREA THAT HAS THE BEST CHANCES FOR RAIN WILL BE THE FAR SOUTH
AND THE RAINFALL MAY BE LOCALLY HEAVY.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED MAY 21 2014
THURSDAY THROUGH FRIDAY NIGHT THE COLD FRONT WILL REMAIN ACROSS
NORTHERN MISSOURI. INTERNALLY...THE MODELS ARE INDICATING THE THE
ACTIVE ZONE FOR NOCTURNAL THUNDERSTORM COMPLEXES WILL BE CLOSE TO
THE AREA.
THE OVERALL MOISTURE AND FORCING BEING SUGGESTED BY THE MODELS
INDICATES THAT A NOCTURNAL THUNDERSTORM COMPLEX MAY BRUSH THE FAR
SOUTHWEST/SOUTH THURSDAY/THURSDAY NIGHT BUT THEN PUSH THE FRONT
FURTHER TO THE SOUTH/WEST FOR FRIDAY AND FRIDAY NIGHT.
TEMPERATURES WILL BE CLOSE TO NORMAL.
SATURDAY ON...
THE MODEL CONSENSUS HAS MAINLY DRY CONDITIONS ON SATURDAY AS THE
BETTER MOISTURE AND FORCING REMAIN WEST OF THE AREA. TEMPERATURES
WILL BE CLOSE TO NORMAL.
STARTING SATURDAY NIGHT AND CONTINUING THROUGH TUESDAY THE MODEL
CONSENSUS HAS SLIGHT CHANCE TO CHANCE POPS EACH DAY. WILL IT RAIN
CONTINUOUSLY THE ENTIRE TIME. NO. HOWEVER...THE BIG PICTURE
INDICATES THE WEATHER PATTERN WILL BE TURNING MORE ACTIVE WITH
SOUTHWEST FLOW ALOFT DEVELOPING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1239 PM CDT WED MAY 21 2014
A LOW CHANCE FOR AN ISOLATED THUNDERSTORM TO DEVELOP IN VCNTY OR
JUST TO THE SOUTH OF THE BRL TAF SITE LATER THIS AFTERNOON AND
EVENING. TO THE NORTH...ANOTHER LOW CHANCE FOR A BKN MVFR DECK TO
MOVE OUT OF MN AND CLIP THE DBQ TAF SITE FROM 03Z-09Z THU/TONIGHT.
OTHERWISE A VFR TAF CYCLE THROUGH 18Z THU. SFC WINDS TO CONTINUE
TO BECOME MORE NORTHERLY AS THE DAY/EVENING PROGRESSES BEHIND A
COOL FRONT SAGGING TO THE SOUTH ACRS NORTHERN MO AND INTO CENTRAL
IL. NORTHERLY LLVL FLOW AND DRYING SFC DPT ADVECTION SHOULD
PRECLUDE ANY FOG DEVELOPMENT OVERNIGHT INTO EARLY THU MORNING IN
VCNTY OF THE TAF SITES. ..12..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...08
SHORT TERM...08
LONG TERM...08
AVIATION...12
AREA FORECAST DISCUSSION
NWS TOPEKA KS
335 PM CDT Wed May 21 2014
.SHORT TERM...(This Evening through Thursday)
Issued at 311 PM CDT WED MAY 21 2014
Latest surface analysis shows surface trough extending northeast
from a low over the Texas Panhandle to near Topeka then into
northwest Missouri. Dew points have increased to around 66 degrees
to the south of the boundary in east central Kansas. Cu field has
developed along and to the north of the boundary. Convergence was
still weak and capping remains in place as CIN values range from 100
to 200 J/kg at 20Z. 0-6km shear of 40 to 50 kts over the CWA and
shear is forecast to decrease some overnight to around 30 to 40 kts.
Cape was running around 2000-2500 J/kg at late afternoon. If cap is
able to be overcome then isolated thunderstorms could develop and
could become severe with hail and and wind the main Hazards. Have
left small chances for thunderstorms from late afternoon and into
the early evening hours. There does not seem to be any weak waves
that would set anything off. The HRRR and the new 18Z NAM develop
some convection this evening along the frontal boundary and in area
of 850 mb convergence and theta advection. Have increase chances
after 03Z. The next area to watch remains convection moving off the
High Plains and/or developing across south central Kansas. Models
are showing that good moisture transport will focus into central
Kansas by 06Z then veering into northeast Kansas by 12Z with the
increase of the low level jet. Corfidi vectors suggest an eastward
movement to any MCS that would develop out in western Kansas.
Precipitable water values increase to around 1.5 inches along I-70
overnight. Isolated hail and strong winds will be possible with the
MCS as it moves across the state.
Thursday, there still could be some morning convection which will
leave outflow boundaries across the area along with the frontal
boundary. Shear is not as strong as today generally in the
20 to 30 kt range and is less favorable for supercells. There is a
wave that was moving across New Mexico this afternoon that is
progged to be moving into central Kansas on Thursday. Will continue
to keep chance pops going for now. Lows tonight will range from the
lower 60s along the Nebraska border to the upper 60s across east
central Kansas. Highs Thursday will range from the mid 70s in far
northeast Kansas to the mid 80s in east central Kansas.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 311 PM CDT WED MAY 21 2014
The surface front will sag south again Thursday night in wake of
the shortwave trough that will round the upper ridge during the
day Thursday. Proximity of the boundary along with 925-850mb
20-30kt flow moving atop the sfc-850mb boundary could lead to sct
thunderstorms overnight into early Friday. Some low chcs for pops again
Friday although the upper ridge over the area and better low level
focus across western KS suggests chcs are minimal this far east.
Another upper wave will move across the region Friday night into
Saturday so that should bring better chcs for scattered
thunderstorms.
The main upper low will drift into the region Sunday and Monday.
It would appear that Sunday night into Monday would bring the
higher rain chcs as the upper low approaches the area given we
will lack a low level focus both days. The upper low will finally
depart Tuesday so precip chcs will diminish then with a dry
weather expected by mid to late week.
&&
.AVIATION...(For the 18Z TAFs through 18Z Thursday Afternoon)
Issued at 1233 PM CDT WED MAY 21 2014
VFR conditions are expected through the period outside of
convection. Frontal boundary/sfc trough hovering near or just
south of the terminals at the beginning of the period should
slowly move south. hi-resolution models develop some convection
along and south of the front after 22Z. Staying with VCTS for now
after 03Z as confidence is not high on timing. May see a cluster
of storms after 08Z which may affect the terminals through 14Z
keeping vcts going through then.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...Omitt
AVIATION...53
AREA FORECAST DISCUSSION
NWS GOODLAND KS
228 PM MDT WED MAY 21 2014
.SHORT TERM...(THIS AFTERNOON INTO TONIGHT)
ISSUED AT 205 PM MDT WED MAY 21 2014
MAIN CHANGE FOR THIS TIME PERIOD WAS TO SLOW THE ONSET OF
THUNDERSTORM DEVELOPMENT. FRONT WAS DRAPED RATHER FAR SOUTH AND
ALONG THE FRONT RANGE TO THE WEST. AN AREA OF SURFACE CONVERGENCE
EXTENDED FROM KIT CARSON AND CHEYENNE COUNTIES TOWARD THE
NORTHWEST. RATHER STRONG SURFACE WINDS OCCURRING OVER THE AREA AT
THIS TIME. SHORTWAVE TROUGH OVER NEW MEXICO IS EXPECTED TO MOVE
TOWARD THE NORTHEAST THROUGH THE NIGHT WITH A SLUG OF SUBTROPICAL
MOISTURE COMING IN ADVANCE OF IT. ALSO A RIGHT REAR QUADRANT OF
THE JET STARTS OVER THE SOUTHWEST HALF OF THE AREA LATE THIS
AFTERNOON INTO THE EVENING HOURS.
THIS IS ALL STARTING A LITTLE SLOWER THAN WHAT THE EARLIER FORECAST
HAD. AREA RADARS/SATELLITE/LIGHTNING DETECTION SHOW AN AREA/LINE
OF STORMS DEVELOPING FROM SOUTHWEST KANSAS INTO SOUTHEAST COLORADO
TO ALONG THE NORTHERN COLORADO FRONT RANGE. WHERE THE MAIN PROBLEM
IS FOR THIS FORECAST IS THAT THE MODELS DISAGREE ON WHERE TO PUT
THE MAIN SWATCH OF STORMS/QPF. SOME TAKE THE MAIN AREA OVER THE
NORTHWEST HALF...SOME OVER THE SOUTHEAST PORTION CLOSEST TO THE
FRONT AND SOME DO BOTH.
THE HRRR WHICH HAS BEEN DOING WELL RECENTLY HAS TRENDED FROM
TAKING A BROKEN SWATH OF PRECIPITATION FROM SOUTHWEST TO NORTHEAST
ACROSS THE ENTIRE CWA TO THE TWO DIFFERENT AREAS OVER THE SOUTHEAST
AND NORTHWEST. ALSO THE MODELS ARE ALSO INDICATING A COUPLE OF
DIFFERENT WAVES OF PRECIPITATION. ONE THIS EVENING WITH THIS
IN ITAL WAVE AND THEN ANOTHER ONE LATER TONIGHT. ALL IN ALL THERE
LOOKS TO BE SOME KIND OF PRECIPITATION MOVING ACROSS MOST OF THE
AREA...JUST NOT SURE EXACTLY WHERE.
.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 228 PM MDT WED MAY 21 2014
THE FOCUS/MAIN CONCERNS FOR THE LONG TERM FORECAST PERIOD ARE SEVERE
WEATHER CHANCES AND POTENTIAL FOR HEAVY RAINS. THE PRIMARY TIME FOR
SEVERE WEATHER WITHIN THE LONG-TERM FORECAST RESIDES ON THURSDAY
AND THURSDAY NIGHT. THREAT FOR HEAVY RAINS WILL BE HIGHEST FROM
THURSDAY THROUGH SATURDAY NIGHT.
ON THURSDAY...A LULL IN CONVECTIVE ACTIVITY SEEMS PROBABLE FOR
THURSDAY MORNING BEFORE ACTIVITY ONCE AGAIN RAMPS UP IN THE
AFTERNOON. IN A SIMILAR SCENARIO TO WEDNESDAY...THUNDERSTORMS
DEVELOP TO THE SOUTH AND WEST ALONG A STALLED FRONT...CONVECTIVE
OUTFLOWS AND THE FRONT RANGE. THUNDERSTORMS THEN SPREAD NORTHEAST
ACROSS THE FORECAST AREA. INSTABILITY MAY BE HIGHER THURSDAY
COMPARED TO TODAY...HOWEVER...THE SHEAR SIGNIFICANTLY DECREASES. DO
NOT THINK THE TORNADO OR SUPERCELL THREAT IS AS HIGH FOR THURSDAY
COMPARED TO WEDNESDAY. PULSE-LIKE HAIL STORMS AND CONVECTIVE
CLUSTERS SHOULD BE THE PRIMARY STORM MODES WITH LARGE HAIL AND
DAMAGING WINDS AS THE MAIN THREAT. SOME SIGNIFICANT HAIL AT OR ABOVE
2 INCHES REMAINS POSSIBLE.
FROM THURSDAY NIGHT THROUGH MONDAY...SHOWER AND THUNDERSTORM CHANCES
CONTINUE ACROSS THE FORECAST AREA AS THE UPPER LEVEL LOW REMAINS
OVER THE WESTERN UNITED STATES. HAVE ADVERTISED THE BEST CHANCES FOR
RAIN IN THE AFTERNOON AND EVENING EACH DAY AS SHORTWAVE TROUGHS PASS
THROUGH AND DAYTIME INSTABILITY IS HIGHEST. IT IS POSSIBLE THAT
CONVECTION CONTINUES THROUGHOUT THE NIGHT ON THURSDAY AND POSSIBLY
FRIDAY. THE UPPER LEVEL LOW PRESSURE SYSTEM EJECTS OVER THE PLAINS
MONDAY AND CLEARS OUT TO THE EAST BY TUESDAY. MODELS HAVE SLOWED THE
SYSTEM SLIGHTLY SO HAVE PULLED POPS BACK TO THE WEST SOME.
WITH RESPECT TO POTENTIAL FLASH FLOODING...AGAIN THE HIGHEST
POTENTIAL FOR THIS THREAT IS BETWEEN THURSDAY NIGHT AND SATURDAY
NIGHT. PRECIPITABLE WATER READINGS APPROACH TO EXCEED 2 STANDARD
DEVIATIONS ABOVE NORMAL FOR THIS TIME OF YEAR. SEVERAL CLUSTERS WILL
PASS THROUGH WITH HEAVY RAIN RATES AND SUFFICIENT INSTABILITY. STILL
UNSURE ABOUT THIS BECOMING A WIDESPREAD FLOODING EVENT DUE TO
UNCERTAINTY IN EXACT STORM MOVEMENT. IF THERE WERE TO BE FLASH
FLOODING...THE MOST LIKELY LOCATION IS NORTHWEST KANSAS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1143 AM MDT WED MAY 21 2014
AT THIS TIME IT LOOKS LIKE THUNDERSTORMS WILL WILL NOT AFFECT
EITHER TAF SITE UNTIL THE EVENING HOURS AT THE EARLIEST. AT BOTH
SITES IT LOOKS LIKE CONDITIONS WILL STAY VFR WITH THE THUNDERSTORMS
UNLESS A STRONG TO SEVERE THUNDERSTORMS MOVES OVERHEAD WHICH COULD
LEAD TO MVFR CONDITIONS. THE BEST CHANCE FOR THIS LOOKS TO BE AT
KGLD BUT ALSO COULD BE STRATUS THAT DEVELOPS IN THE WAKE OF
WHATEVER THUNDERSTORM ACTIVITY HAS OCCURRED. THE MVFR CONDITIONS
LOOK TO OCCUR AT KGLD DURING THE LAST HALF OF THE PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
223 PM MDT WED MAY 21 2014
.SHORT TERM...(THIS AFTERNOON INTO TONIGHT)
ISSUED AT 205 PM MDT WED MAY 21 2014
MAIN CHANGE FOR THIS TIME PERIOD WAS TO SLOW THE ONSET OF
THUNDERSTORM DEVELOPMENT. FRONT WAS DRAPED RATHER FAR SOUTH AND
ALONG THE FRONT RANGE TO THE WEST. AN AREA OF SURFACE CONVERGENCE
EXTENDED FROM KIT CARSON AND CHEYENNE COUNTIES TOWARD THE
NORTHWEST. RATHER STRONG SURFACE WINDS OCCURRING OVER THE AREA AT
THIS TIME. SHORTWAVE TROUGH OVER NEW MEXICO IS EXPECTED TO MOVE
TOWARD THE NORTHEAST THROUGH THE NIGHT WITH A SLUG OF SUBTROPICAL
MOISTURE COMING IN ADVANCE OF IT. ALSO A RIGHT REAR QUADRANT OF
THE JET STARTS OVER THE SOUTHWEST HALF OF THE AREA LATE THIS
AFTERNOON INTO THE EVENING HOURS.
THIS IS ALL STARTING A LITTLE SLOWER THAN WHAT THE EARLIER FORECAST
HAD. AREA RADARS/SATELLITE/LIGHTNING DETECTION SHOW AN AREA/LINE
OF STORMS DEVELOPING FROM SOUTHWEST KANSAS INTO SOUTHEAST COLORADO
TO ALONG THE NORTHERN COLORADO FRONT RANGE. WHERE THE MAIN PROBLEM
IS FOR THIS FORECAST IS THAT THE MODELS DISAGREE ON WHERE TO PUT
THE MAIN SWATCH OF STORMS/QPF. SOME TAKE THE MAIN AREA OVER THE
NORTHWEST HALF...SOME OVER THE SOUTHEAST PORTION CLOSEST TO THE
FRONT AND SOME DO BOTH.
THE HRRR WHICH HAS BEEN DOING WELL RECENTLY HAS TRENDED FROM
TAKING A BROKEN SWATH OF PRECIPITATION FROM SOUTHWEST TO NORTHEAST
ACROSS THE ENTIRE CWA TO THE TWO DIFFERENT AREAS OVER THE SOUTHEAST
AND NORTHWEST. ALSO THE MODELS ARE ALSO INDICATING A COUPLE OF
DIFFERENT WAVES OF PRECIPITATION. ONE THIS EVENING WITH THIS
IN ITAL WAVE AND THEN ANOTHER ONE LATER TONIGHT. ALL IN ALL THERE
LOOKS TO BE SOME KIND OF PRECIPITATION MOVING ACROSS MOST OF THE
AREA...JUST NOT SURE EXACTLY WHERE.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 337 AM MDT WED MAY 21 2014
MEDIUM RANGE MODEL CONSENSUS IS FOR THE SOUTHWEST CONUS CLOSED UPPER
LOW TO DRIFT EASTWARD TOWARD THE CENTRAL HIGH PLAINS REGION.
CONFIDENCE IN THIS SOLUTION IS ABOVE AVERAGE GIVEN RELATIVELY LITTLE
SPREAD IN THE DETERMINISTIC AND ENSEMBLE GUIDANCE...ALTHOUGH
RELATIVELY MINOR TIMING AND PLACEMENT DISCREPANCIES SHOW UP TOWARD
THE BEGINNING OF THE WEEK. CURRENT SOLUTION IS FOR THE UPPER LOW TO
PASS JUST SOUTH OF THE FORECAST AREA ACROSS SOUTHERN KANSAS LATE
MONDAY AND EARLY TUESDAY SHIFTING THE DEEP MOISTURE TO THE EAST.
UPPER LEVEL RIDGING WILL QUICKLY BUILD IN TOWARD THE MIDDLE OF THE
WEEK.
AHEAD OF THE UPPER LOW THE MEAN FLOW WILL BE MERIDIONAL WITH A
PERSISTENT BELT OF DEEP MOISTURE EXTENDING FROM THE WESTERN GULF
NORTHWARD INTO THE REGION. PWAT VALUES WILL BE CONSISTENTLY OVER ONE
INCH FOR MUCH OF THE PERIOD...ESPECIALLY ACROSS THE EAST. FORCING
FOR ASCENT FROM THE UPPER LOW...DEEP ANOMALOUS MOISTURE...AND STORM
MOTIONS AROUND 15 KNOTS OR LESS RAISE CONCERN FOR HEAVY RAINFALL
AMOUNTS. ADJUSTED QPF UPWARD SLIGHTLY TO BE MORE IN LINE WITH WPC
GUIDANCE. FLOODING CONCERNS AT THIS TIME ARE MINIMAL SINCE
CUMULATIVE AMOUNTS THAT MAY EXCEED TWO INCHES WILL OCCUR OVER THE
SPAN OF SEVERAL DAYS. THIS WILL NEED TO BE MONITORED...ESPECIALLY ON
A LOCALIZED BASIS IF TRAINING OF CONVECTIVE CELLS DEVELOPS.
COMPARED TO THE NEAR TERM...MID LEVEL LAPSE RATES ARE NOT AS STEEP
AND CAPE IS RELATIVELY SKINNY DURING THE EXTENDED PERIOD. THIS IS
TYPICAL OF SUCH A PATTERN WHICH SUPPORTS ANOMALOUS DEEP MOISTURE.
THIN CAPE AND WEAK SHEAR WILL LIMIT THE SEVERE POTENTIAL THROUGH THE
PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1143 AM MDT WED MAY 21 2014
AT THIS TIME IT LOOKS LIKE THUNDERSTORMS WILL WILL NOT AFFECT
EITHER TAF SITE UNTIL THE EVENING HOURS AT THE EARLIEST. AT BOTH
SITES IT LOOKS LIKE CONDITIONS WILL STAY VFR WITH THE THUNDERSTORMS
UNLESS A STRONG TO SEVERE THUNDERSTORMS MOVES OVERHEAD WHICH COULD
LEAD TO MVFR CONDITIONS. THE BEST CHANCE FOR THIS LOOKS TO BE AT
KGLD BUT ALSO COULD BE STRATUS THAT DEVELOPS IN THE WAKE OF
WHATEVER THUNDERSTORM ACTIVITY HAS OCCURRED. THE MVFR CONDITIONS
LOOK TO OCCUR AT KGLD DURING THE LAST HALF OF THE PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...RB
AVIATION...BULLER
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
655 PM EDT WED MAY 21 2014
.UPDATE...
ISSUED AT 655 PM EDT WED MAY 21 2014
NOW THAT WE ARE UNDER A SEVERE THUNDERSTORM WATCH BOX UNTIL 2 AM EDT
HAVE UPDATED ALL THE GRIDS THROUGH THE NIGHT TO REFLECT THE SEVERE
THREATS AND TIME THE STORM CLUSTERS AS FORECASTED BY THE HRRR. DID
TEMPER THE PROGNOSIS FROM THAT MODEL WITH THE EXISTING GRIDS AND
ALSO THE 18Z NAM12. IT DOES LOOK LIKE COLD POOLS ARE DEVELOPING WITH
THE CURRENT CLUSTERS TO THE NORTH AND THIS SHOULD HELP DRIVE STRONG
TO SEVERE STORMS SOUTH INTO OUR CWA QUICKER. HAVE TIMED THE STORMS
INTO THE JACKSON AREA AROUND 9 PM WITH THEM ARRIVING AN HOUR OR SO ON
EITHER SIDE OF THAT TIME NORTHWEST AND SOUTHEAST OF THE OFFICE. KEPT
IN THE HEAVY RAIN POTENTIAL AND THE HRRR IS NOW SHOWING BETTER
TRAINING POTENTIAL FOR OUR WESTERN COUNTIES THROUGH THE NIGHT. LARGE
HAIL AND GUSTY WINDS ARE STILL THE MAIN THREATS...THOUGH. DO EXPECT
THE SEVERE MODE TO TRANSITION TO A MAINLY DAMAGING WINDS ONE OVER THE
NEXT FEW HOURS. THESE GRID UPDATES AND THE NEW WCN/ZFP/HWO HAVE BEEN
ISSUED.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 350 PM EDT WED MAY 21 2014
18Z SFC ANALYSIS SHOWS LOW PRESSURE OVER THE GREAT LAKES WITH A COLD
FRONT EXTENDING SOUTHWEST THROUGH THE NORTHWEST OHIO VALLEY AND INTO
THE MIDDLE OF MISSOURI. SOUTHEAST OF THIS...PLENTY OF FUEL IS
BUILDING FOR CONVECTION IN THE FORM OF DEWPOINTS IN THE LOW TO MID
60S AND TEMPERATURES PUSHING 80 DEGREES. THIS HAS HELPED TO PRIME
EAST KENTUCKY FOR CONVECTION LATER IN THE EVENING AND THROUGH THE
NIGHT. A FEW ROGUE SHOWERS ARE POPPING UP AND DRIFTING EAST THROUGH
THE AREA THIS AFTERNOON...BUT THE MAIN SHOW LATER THIS EVENING WILL
BE ASSOCIATED WITH THE ONGOING STORMS IN OHIO AND INDIANA EITHER
DIRECTLY OR AS A RE-SPAWNED CLUSTER ON AN OUTFLOW BOUNDARY. ON
SATELLITE...THE HIGHER DEBRIS CLOUDS ARE STARTING TO CLEAR FROM THE
EARLIER CONVECTION TO THE NORTH. THIS SHOULD HELP GIVE A FINAL PUSH
TO THE INSTABILITY OVER THE NEXT SEVERAL HOURS...THOUGH LOWER CLOUDS
WILL REMAIN DUE TO THIS HUMID ENVIRONMENT. MEANWHILE...WINDS ARE FROM
THE SOUTHWEST TO WEST AT 10 TO 20 MPH WITH SOME GUSTS TO 25 MPH.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH RIDGING RETREATING TO THE
SOUTH TONIGHT IN THE FACE OF A DECENTLY STRONG SHORTWAVE MOVING
THROUGH FAST NORTHWEST FLOW...CROSSING NORTHERN KENTUCKY. THIS FLOW
PATTERN REMAINS IN PLACE INTO THE DAY THURSDAY WITH JUST A SLIGHT
SHIFT TO THE SOUTHWEST WITH THE MID LEVEL ENERGY TRACK. HEIGHT FALLS
WILL ACCOMPANY THIS ADJUSTMENT THROUGH EAST KENTUCKY INTO FRIDAY
MORNING IN CONJUNCTION WITH A SHARPER TROUGH SWEEPING SOUTHEAST
THROUGH THE EASTERN GREAT LAKES. WITH THIS AGREEMENT HAVE MAINLY
FOLLOWED THE GENERAL DETAILS FROM THE CURRENT AND PAST FEW RUNS OF
THE HRRR ALONG WITH SOME NAM12 INFLUENCE.
SENSIBLE WEATHER WILL FEATURE A LIKELY STORMY NIGHT ACROSS THE AREA.
THE HEIGHT FALLS...ENERGY PERTURBANCES AT MID LEVELS...AND A SPEED
MAX AT 500MB KEEPS THE STAGE SET FOR CONVECTIVE REDEVELOPMENT THROUGH
THE NIGHT INTO THURSDAY. INCREASING PWS...TOWARD 1.5 INCHES...THROUGH
THE AREA WILL CONTRIBUTE TO A POTENTIAL FOR HEAVY TO EXCESSIVE
AMOUNTS OF RAIN TONIGHT....ESPECIALLY IF SOLID COLD POOLS DEVELOP
ALONG WITH TRAINING OF CELLS. HOWEVER...CONFIDENCE IN ANY EXACT
SCENARIO REMAINS LOW GIVEN THE DEVELOPING CONVECTION PATTERN AND THE
CHALLENGE OF PREDICTING SUBSEQUENT INITIATION OFF OF THE SOUTHWARD
MOVING OUTFLOW BOUNDARIES. A LACK OF A CAP AND LIS TO -6/CAPES TO
2000 J/KG WILL ALSO MEAN A GOOD POTENTIAL FOR SEVERE WEATHER WITH ANY
ORGANIZED STORMS THIS EVENING AND INTO THE OVERNIGHT...SHOULD PRIOR
CONVECTION NOT STABILIZE THE ENVIRONMENT. HAVE HIT THIS POTENTIAL
HARD IN THE GRIDS...ZONES...AND HWO. AFTER A MILD NIGHT...A BOUNDARY
SHOULD BE LAYING FROM NORTHWEST TO SOUTHEAST ACROSS EAST KENTUCKY
WITH STILL A POTENTIAL FOR STRONG STORMS ACROSS SOUTHWESTERN PARTS
OF THE AREA. HAVE CONTINUED THIS THREAT INTO THE AFTERNOON. THE
BOUNDARY SHOULD WEAKEN AND DRIFT FURTHER SOUTHEAST INTO THE NIGHT
WITH LESS OF A RISK FOR CONVECTION. COOLER TEMPS WILL BE FOUND
THURSDAY NIGHT OVER OUR NORTHEAST WITH MILDER AND MUGGIER CONDITIONS
SOUTHWEST.
USED THE BCCONSSHORT GRIDS AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN TACKED ON
THE BCCONSALL. MOST ADJUSTMENTS WHERE MADE FOR TERRAIN DIFFERENCES
TONIGHT AND THURSDAY NIGHT. AS FOR POPS...ENDED UP ON THE HIGH SIDE
OF ALL GUIDANCE...BUT CLOSEST TO THE HIGHER MET NUMBERS TONIGHT AND
THURSDAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 300 PM EDT WED MAY 21 2014
EXTENDED MODELS ARE IN REASONABLE AGREEMENT THROUGH THE PERIOD...BUT
AS USUAL THERE IS BETTER AGREEMENT WITH LARGE SCALE FEATURES THAN
WITH DETAILS. WE START WITH AN UPPER LEVEL DISTURBANCE THAT DROPS
SOUTHEAST THROUGH THE REGION FRIDAY...EFFECTIVELY JUMP STARING A
TEMPORARILY STALLED OUT SFC COLD FRONTAL BOUNDARY AND SWEEPING IT
OUT OF OUR AREA. THEREAFTER UPPER LEVEL RIDGING AND SFC HIGH
PRESSURE WILL BUILD OVER OUR AREA AND PROVIDE US WITH VERY PLEASANT
WEATHER FOR THE UPCOMING WEEKEND.
MODELS DIFFER MORE WITH RETURN FLOW REGIME EARLY NEXT WEEK. WARM
FRONTAL ZONE WILL MOVE BACK TO THE NORTH ACROSS THE AREA MONDAY AND
COULD PROVIDE SOME PRECIPITATION TO EASTERN KENTUCKY. THEREAFTER WE
FIND OURSELVES IN THE WARM SECTOR AND MORE SUMMER LIKE WEATHER UNTIL
THE POTENTIAL ARRIVAL OF A LOW PRESSURE SYSTEM THAT WILL SLOWLY
MEANDER ITS WAY OUT OF THE CENTRAL PLAINS. 0Z ECMWF WANTS TO BRING
THIS SLOW MOVING DISTURBANCE INTO THE HEART OF THE OHIO VALLEY BY
LATE THURSDAY INTO FRIDAY...JUST BEYOND THE FORECAST WINDOW. A MUCH
MORE INCONSISTENT GFS...AND MORE SPECIFICALLY THE 12Z RUN WANTS TO
TAKE THE DISTURBANCE TO THE GULF COAST...WHILE DEVELOPING A MUCH
STRONGER SYSTEM OVER THE OHIO VALLEY FROM ENERGY DROPPING OUT OF
CANADA DURING THAT SME TIME FRAME. PAST RUNS OF THE ECMWF HAVE SHOWN
A TENDENCY TO TAKE THE DISTURBANCE TO THE GULF COAST AS WELL...BUT
HAS NOT SHOWN ANY EVIDENCE OF SUCH A STRONG SYSTEM DROPPING OUT OF
CANADA.
FOR SENSIBLE WEATHER...ATMOSPHERE STABILIZES RAPIDLY EARLY FRIDAY
MORNING. SO ANY SHOWERS THAT MIGHT LINGER ACROSS THE AREA THURSDAY
NIGHT WILL COME TO AN END JUST AS QUICKLY EARLY FRIDAY MORNING. HIGH
PRESSURE AND A PLEASANTLY COOL AIR MASS OVER THE AREA WILL PROVIDE
GREAT WEATHER FOR THE WEEKEND. WEATHER WILL TURN MUGGY AND RELATIVELY
HOT EARLY NEXT WEEK AFTER A WARM FRONT PUNCHES ITS WAY ACROSS OUR
AREA TO THE NORTH. FOR NOW IT APPEARS THE THREAT OF SHOWERS AND
THUNDERSTORMS WILL INCREASE DAILY THROUGH THE REMAINDER OF THE
WEEK...BUT MUCH WILL DEPEND ON THE PATTERN THAT SETS UP AT THE END
OF THE FORECAST WINDOW AND BEYOND. THE ECMWF AND GFS BOTH ADVERTISE
UNSETTLED WEATHER OVER OUR AREA BY THE END OF THE WEEK BUT VIA
DIFFERENT MEANS TO THAT END. AT THIS POINT AND AFTER CONSIDERING THE
TIME OF YEAR THOUGHTS ARE THAT ANYTHING IS POSSIBLE BEYOND TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 220 PM EDT WED MAY 21 2014
CONDITIONS ARE CURRENTLY VFR THROUGH THE AREA...BUT CIGS ARE NEAR
MVFR IN THIS HUMID ENVIRONMENT. CONVECTION IS EXPECTED LATER THIS
EVENING THROUGH THE ENTIRE FORECAST AREA WITH A POTENTIAL FOR
ORGANIZED AND UPSCALE DEVELOPMENT. INITIALLY...HAVE TIMED A
CONVECTIVE EVENT THROUGH THE TAF SITES DURING THE MID EVENING BASED
ON THE LATEST HRRR. HAVE LEFT VCTS IN THE TAFS FOR THE REST OF
THE NIGHT DUE TO A CONTINUED POTENTIAL FOR REDEVELOPMENT ALONG WITH
MVFR CIGS. THERE WILL LIKELY BE A LULL AND BETTER CONDITIONS FOR A
TIME EARLY IN THE MORNING OF THURSDAY...BUT FOR NOW WILL LEAVE THE
VCTS AND LOWER CIGS PREVAILING. WINDS WILL BE BREEZY FROM THE WEST
SOUTHWEST THROUGH THE EVENING WITH GUSTS TO 20 AND 25 KTS...BUT
CLOSER TO 35 KTS...OR HIGHER...WITH ANY STORMS THIS EVENING. WEST
WINDS OF 10 TO 20 KTS FOLLOW THROUGH THE REMAINDER OF THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...RAY
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
350 PM EDT WED MAY 21 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 350 PM EDT WED MAY 21 2014
18Z SFC ANALYSIS SHOWS LOW PRESSURE OVER THE GREAT LAKES WITH A COLD
FRONT EXTENDING SOUTHWEST THROUGH THE NORTHWEST OHIO VALLEY AND INTO
THE MIDDLE OF MISSOURI. SOUTHEAST OF THIS...PLENTY OF FUEL IS
BUILDING FOR CONVECTION IN THE FORM OF DEWPOINTS IN THE LOW TO MID
60S AND TEMPERATURES PUSHING 80 DEGREES. THIS HAS HELPED TO PRIME
EAST KENTUCKY FOR CONVECTION LATER IN THE EVENING AND THROUGH THE
NIGHT. A FEW ROGUE SHOWERS ARE POPPING UP AND DRIFTING EAST THROUGH
THE AREA THIS AFTERNOON...BUT THE MAIN SHOW LATER THIS EVENING WILL
BE ASSOCIATED WITH THE ONGOING STORMS IN OHIO AND INDIANA EITHER
DIRECTLY OR AS A RE-SPAWNED CLUSTER ON AN OUTFLOW BOUNDARY. ON
SATELLITE...THE HIGHER DEBRIS CLOUDS ARE STARTING TO CLEAR FROM THE
EARLIER CONVECTION TO THE NORTH. THIS SHOULD HELP GIVE A FINAL PUSH
TO THE INSTABILITY OVER THE NEXT SEVERAL HOURS...THOUGH LOWER CLOUDS
WILL REMAIN DUE TO THIS HUMID ENVIRONMENT. MEANWHILE...WINDS ARE FROM
THE SOUTHWEST TO WEST AT 10 TO 20 MPH WITH SOME GUSTS TO 25 MPH.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH RIDGING RETREATING TO THE
SOUTH TONIGHT IN THE FACE OF A DECENTLY STRONG SHORTWAVE MOVING
THROUGH FAST NORTHWEST FLOW...CROSSING NORTHERN KENTUCKY. THIS FLOW
PATTERN REMAINS IN PLACE INTO THE DAY THURSDAY WITH JUST A SLIGHT
SHIFT TO THE SOUTHWEST WITH THE MID LEVEL ENERGY TRACK. HEIGHT FALLS
WILL ACCOMPANY THIS ADJUSTMENT THROUGH EAST KENTUCKY INTO FRIDAY
MORNING IN CONJUNCTION WITH A SHARPER TROUGH SWEEPING SOUTHEAST
THROUGH THE EASTERN GREAT LAKES. WITH THIS AGREEMENT HAVE MAINLY
FOLLOWED THE GENERAL DETAILS FROM THE CURRENT AND PAST FEW RUNS OF
THE HRRR ALONG WITH SOME NAM12 INFLUENCE.
SENSIBLE WEATHER WILL FEATURE A LIKELY STORMY NIGHT ACROSS THE AREA.
THE HEIGHT FALLS...ENERGY PERTURBANCES AT MID LEVELS...AND A SPEED
MAX AT 500MB KEEPS THE STAGE SET FOR CONVECTIVE REDEVELOPMENT THROUGH
THE NIGHT INTO THURSDAY. INCREASING PWS...TOWARD 1.5 INCHES...THROUGH
THE AREA WILL CONTRIBUTE TO A POTENTIAL FOR HEAVY TO EXCESSIVE
AMOUNTS OF RAIN TONIGHT....ESPECIALLY IF SOLID COLD POOLS DEVELOP
ALONG WITH TRAINING OF CELLS. HOWEVER...CONFIDENCE IN ANY EXACT
SCENARIO REMAINS LOW GIVEN THE DEVELOPING CONVECTION PATTERN AND THE
CHALLENGE OF PREDICTING SUBSEQUENT INITIATION OFF OF THE SOUTHWARD
MOVING OUTFLOW BOUNDARIES. A LACK OF A CAP AND LIS TO -6/CAPES TO
2000 J/KG WILL ALSO MEAN A GOOD POTENTIAL FOR SEVERE WEATHER WITH ANY
ORGANIZED STORMS THIS EVENING AND INTO THE OVERNIGHT...SHOULD PRIOR
CONVECTION NOT STABILIZE THE ENVIRONMENT. HAVE HIT THIS POTENTIAL
HARD IN THE GRIDS...ZONES...AND HWO. AFTER A MILD NIGHT...A BOUNDARY
SHOULD BE LAYING FROM NORTHWEST TO SOUTHEAST ACROSS EAST KENTUCKY
WITH STILL A POTENTIAL FOR STRONG STORMS ACROSS SOUTHWESTERN PARTS
OF THE AREA. HAVE CONTINUED THIS THREAT INTO THE AFTERNOON. THE
BOUNDARY SHOULD WEAKEN AND DRIFT FURTHER SOUTHEAST INTO THE NIGHT
WITH LESS OF A RISK FOR CONVECTION. COOLER TEMPS WILL BE FOUND
THURSDAY NIGHT OVER OUR NORTHEAST WITH MILDER AND MUGGIER CONDITIONS
SOUTHWEST.
USED THE BCCONSSHORT GRIDS AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN TACKED ON
THE BCCONSALL. MOST ADJUSTMENTS WHERE MADE FOR TERRAIN DIFFERENCES
TONIGHT AND THURSDAY NIGHT. AS FOR POPS...ENDED UP ON THE HIGH SIDE
OF ALL GUIDANCE...BUT CLOSEST TO THE HIGHER MET NUMBERS TONIGHT AND
THURSDAY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 300 PM EDT WED MAY 21 2014
EXTENDED MODELS ARE IN REASONABLE AGREEMENT THROUGH THE PERIOD...BUT
AS USUAL THERE IS BETTER AGREEMENT WITH LARGE SCALE FEATURES THAN
WITH DETAILS. WE START WITH AN UPPER LEVEL DISTURBANCE THAT DROPS
SOUTHEAST THROUGH THE REGION FRIDAY...EFFECTIVELY JUMP STARING A
TEMPORARILY STALLED OUT SFC COLD FRONTAL BOUNDARY AND SWEEPING IT
OUT OF OUR AREA. THEREAFTER UPPER LEVEL RIDGING AND SFC HIGH
PRESSURE WILL BUILD OVER OUR AREA AND PROVIDE US WITH VERY PLEASANT
WEATHER FOR THE UPCOMING WEEKEND.
MODELS DIFFER MORE WITH RETURN FLOW REGIME EARLY NEXT WEEK. WARM
FRONTAL ZONE WILL MOVE BACK TO THE NORTH ACROSS THE AREA MONDAY AND
COULD PROVIDE SOME PRECIPITATION TO EASTERN KENTUCKY. THEREAFTER WE
FIND OURSELVES IN THE WARM SECTOR AND MORE SUMMER LIKE WEATHER UNTIL
THE POTENTIAL ARRIVAL OF A LOW PRESSURE SYSTEM THAT WILL SLOWLY
MEANDER ITS WAY OUT OF THE CENTRAL PLAINS. 0Z ECMWF WANTS TO BRING
THIS SLOW MOVING DISTURBANCE INTO THE HEART OF THE OHIO VALLEY BY
LATE THURSDAY INTO FRIDAY...JUST BEYOND THE FORECAST WINDOW. A MUCH
MORE INCONSISTENT GFS...AND MORE SPECIFICALLY THE 12Z RUN WANTS TO
TAKE THE DISTURBANCE TO THE GULF COAST...WHILE DEVELOPING A MUCH
STRONGER SYSTEM OVER THE OHIO VALLEY FROM ENERGY DROPPING OUT OF
CANADA DURING THAT SME TIME FRAME. PAST RUNS OF THE ECMWF HAVE SHOWN
A TENDENCY TO TAKE THE DISTURBANCE TO THE GULF COAST AS WELL...BUT
HAS NOT SHOWN ANY EVIDENCE OF SUCH A STRONG SYSTEM DROPPING OUT OF
CANADA.
FOR SENSIBLE WEATHER...ATMOSPHERE STABILIZES RAPIDLY EARLY FRIDAY
MORNING. SO ANY SHOWERS THAT MIGHT LINGER ACROSS THE AREA THURSDAY
NIGHT WILL COME TO AN END JUST AS QUICKLY EARLY FRIDAY MORNING. HIGH
PRESSURE AND A PLEASANTLY COOL AIR MASS OVER THE AREA WILL PROVIDE
GREAT WEATHER FOR THE WEEKEND. WEATHER WILL TURN MUGGY AND RELATIVELY
HOT EARLY NEXT WEEK AFTER A WARM FRONT PUNCHES ITS WAY ACROSS OUR
AREA TO THE NORTH. FOR NOW IT APPEARS THE THREAT OF SHOWERS AND
THUNDERSTORMS WILL INCREASE DAILY THROUGH THE REMAINDER OF THE
WEEK...BUT MUCH WILL DEPEND ON THE PATTERN THAT SETS UP AT THE END
OF THE FORECAST WINDOW AND BEYOND. THE ECMWF AND GFS BOTH ADVERTISE
UNSETTLED WEATHER OVER OUR AREA BY THE END OF THE WEEK BUT VIA
DIFFERENT MEANS TO THAT END. AT THIS POINT AND AFTER CONSIDERING THE
TIME OF YEAR THOUGHTS ARE THAT ANYTHING IS POSSIBLE BEYOND TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 220 PM EDT WED MAY 21 2014
CONDITIONS ARE CURRENTLY VFR THROUGH THE AREA...BUT CIGS ARE NEAR
MVFR IN THIS HUMID ENVIRONMENT. CONVECTION IS EXPECTED LATER THIS
EVENING THROUGH THE ENTIRE FORECAST AREA WITH A POTENTIAL FOR
ORGANIZED AND UPSCALE DEVELOPMENT. INITIALLY...HAVE TIMED A
CONVECTIVE EVENT THROUGH THE TAF SITES DURING THE MID EVENING BASED
ON THE LATEST HRRR. HAVE LEFT VCTS IN THE TAFS FOR THE REST OF
THE NIGHT DUE TO A CONTINUED POTENTIAL FOR REDEVELOPMENT ALONG WITH
MVFR CIGS. THERE WILL LIKELY BE A LULL AND BETTER CONDITIONS FOR A
TIME EARLY IN THE MORNING OF THURSDAY...BUT FOR NOW WILL LEAVE THE
VCTS AND LOWER CIGS PREVAILING. WINDS WILL BE BREEZY FROM THE WEST
SOUTHWEST THROUGH THE EVENING WITH GUSTS TO 20 AND 25 KTS...BUT
CLOSER TO 35 KTS...OR HIGHER...WITH ANY STORMS THIS EVENING. WEST
WINDS OF 10 TO 20 KTS FOLLOW THROUGH THE REMAINDER OF THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...RAY
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
310 PM EDT WED MAY 21 2014
.UPDATE...
ISSUED AT 310 PM EDT WED MAY 21 2014
WITH THE EVOLUTION OF THIS EVENT COMING INTO CLEARER FOCUS...PER THE
LATEST HRRR AND OUTLOOKS/WATCH BOXES FROM SPC...HAVE UPDATED THE POP
AND WX GRIDS THROUGH THE NIGHT. DID ADD SOME ISOLATED SVR WORDING FOR
WIND AND HAIL TO THE GRIDS FOR THE EVENING OVER OUR NORTHERN ZONES.
ALSO FINE TUNED THE TEMPS AND DEWPOINTS THROUGH THE REST OF THE
AFTERNOON. THESE GRIDS HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1030 AM EDT WED MAY 21 2014
13Z SFC ANALYSIS SHOWS A BROAD AREA OF LOW PRESSURE THROUGH THE GREAT
LAKES AND INTO NORTHERN OHIO. A COLD FRONT IS LOCATED OVER THE
NORTHWEST PORTION OF THE OHIO VALLEY. THIS PLACES EAST KENTUCKY IN A
LARGE WARM SECTOR WELL TO THE SOUTH OF THIS BOUNDARY. DEWPOINTS HAVE
COME UP INTO THE UPPER 50S THROUGH THE AREA WITH LOW 60S POOLING
ALONG AND AHEAD OF THIS FRONT WHERE PWS ARE APPROACHING 1.6 INCHES.
MEANWHILE...TEMPERATURES HAVE CLIMBED INTO THE LOW 70S ALREADY...ON
THEIR WAY TO THE LOWER 80S. CONVECTION IS ONGOING THROUGH THE
NORTHERN PARTS OF THE REGION IN CONNECTION WITH THE LOW AND ITS
FRONTAL STRUCTURE. THIS IS INDICATIVE OF THE ENVIRONMENT AND
CONDITIONS SHOULD ONLY BECOME MORE FAVORABLE IN THE REGION TO THE
NORTH OF THE CWA AS THE DAY WEARS ON...TEMPERATURES SOAR...AND
INSTABILITY CLIMBS. EXPECT OUTFLOW BOUNDARIES FROM THE ONGOING AND
SUBSEQUENT CONVECTION TO WORK THEIR WAY SOUTH INTO EAST KENTUCKY BY
LATE AFTERNOON...PERHAPS ENOUGH SO TO TRIGGER OUR OWN ROUND OF
STORMS...AS THE 12Z NAM SUGGESTS. MOST LIKELY...THOUGH...THE HRRR
HAS THE RIGHT IDEA OF DEVELOPMENT HOLDING OFF UNTIL CLOSER TO 00Z
WHEN A CONVECTIVE CLUSTER IN SOUTHERN INDIANA AND OHIO SURGES INTO
NORTHERN KENTUCKY BRINGING ITS STORMY WEATHER TO OUR PART OF THE
STATE. THE FORECAST SOUNDINGS SUPPORT THIS SCENARIO KEEPING OUR AREA
CAPPED UNTIL AFTER 21Z...WHILE THE INSTABILITY GROWS. ONCE THE CAP IS
GONE THE WIND STRUCTURE THROUGH THE MID LEVELS HAS PRETTY GOOD SPEED
SHEAR TO ACCOMPANY CAPES TO 2K J/KG AND LIS TO -6. THE MIDDAY
SOUNDING EXPECTED OUT OF ILN WILL ALSO HELP TO TELL THE TALE. ALL
THIS SUPPORTS SPC/S SLIGHT RISK MONIKER FOR US THIS AFTERNOON AND
EVENING WITH LARGE HAIL AND DAMAGING WIND GUSTS THE MAIN THREATS.
WILL CONTINUE TO HIGHLIGHT THIS IN THE HWO AND HAVE ADDED A WEB
HEADLINE. OTHERWISE...MADE ONLY SLIGHT ADJUSTMENTS TO THE POP AND WX
GRIDS THROUGH 00Z WITH SOME TWEAKS TO TEMPERATURES AND DEWPOINTS
THROUGH THE REST OF THE DAY PER THE LATEST GUIDANCE...OBS...AND
TRENDS. THESE UPDATES HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 727 AM EDT WED MAY 21 2014
FORECAST ON TRACK SO FAR THIS MORNING SO NO UPDATE IS PLANNED AT THIS
TIME.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 3 AM EDT WED MAY 21 2014
THE MODELS WERE ALL IN PRETTY GOOD AGREEMENT WITH THE LARGE SCALE
WEATHER PATTERN OVER THE NEXT 36 HOURS...THE TIMING OF A FRONTAL
PASSAGE LATER TODAY...AND THE AREAL COVERAGE OF PRECIPITATION
ASSOCIATED WITH THE FRONT. THE TIMING OF THE SOUTHWARD PROGRESSION OF
THE FRONT AND ITS ATTENDANT PRECIPITATION DID SEEM A BIT SLOWER THAN
THE PREVIOUS FORECAST SUGGESTED...SO ADJUSTMENTS WERE MADE TO ACCOUNT
FOR THIS. THE SREF AND NAM12 WERE BOTH USED IN CONJUNCTION TO CREATE
THE NEW FORECAST WITH THEIR PREFERRED FRONTAL PASSAGE TIMING AND
PRECIP DISTRIBUTION ALONG THE FRONT. THE MODEL SOUNDINGS ALL AGREED
THAT STRONG CAPPING WILL BE IN PLACE THROUGH EARLY THIS AFTERNOON.
WITH THAT IN MIND...IT SEEMED THAT LIKELY POPS WOULD BE A BIT
OVERDONE...SO THE NEW FORECAST WILL FEATURE A GENERAL 40 TO 50
PERCENT CHANCE OF RAIN THIS AFTERNOON AND EVENING...WITH SLOWER
SOUTHWARD FRONTAL MOVEMENT. AT THIS TIME THE PRIMARY FORECAST WILL BE
WHETHER OR NOT THERE IS STRONG ENOUGH FORCING AVAILABLE TO OVERCOME
THE STRONG CAPPING INVERSION SEEN IN THE MODEL SOUNDINGS AS AN
ONGOING LINE OF SHOWERS AND STORMS FINALLY MAKES IT WAY INTO THE
LATER TODAY. IT DOES APPEAR THAT WITH THE FRONT PUSHING THROUGH THAT
THERE WILL BE JUST ENOUGH FORCING...LOW LEVEL MOISTURE...AND
INSTABILITY AVAILABLE TO BREAK THE CAP EARLY THIS AFTERNOON. THE
CURRENT SOUNDINGS ARE SUPPORTIVE OF STRONG LOW LEVEL DRYING AND
THEREFORE ENHANCED THUNDERSTORM DOWNDRAFT POTENTIAL...MAKING DAMAGING
WINDS THE PRIMARY THREAT WITH ANY STORMS THAT AREA ABLE TO REACH
SEVERE LIMITS THIS AFTERNOON AND EVENING. SOUTHERLY TO SOUTHWESTERLY
WINDS AHEAD OF THE FRONT WILL PICK UP INTENSITY RATHER QUICKLY THIS
MORNING AS THE SUN BEGINS TO HEAT THINGS UP. SUSTAINED WINDS OF 10 TO
15 MPH WITH GUSTS OF 20 TO 25 MPH WILL BE POSSIBLE THROUGHOUT THE DAY
AHEAD OF THE FRONT.
THE FRONT WILL BE SLOW TO EXIT THE AREA AND MAY ACTUALLY STALL OUT
DURING THE OVERNIGHT HOURS...ALLOWING FOR LINGERING CHANCES OF
SHOWERS AND STORMS OVERNIGHT AND THROUGH THE DAY ON THURSDAY. IT DOES
APPEAR THAT THE FRONT WILL WASH OUT A BIT ON THURSDAY AS THE AIR MASS
NORTH OF THE BOUNDARY WILL ONLY BE SLIGHTLY DRIER THAN THAT TO THE
SOUTH OF IT. WITH THAT IN MIND...DECIDED TO GO WITH GENERAL CHANCE
POPS FOR TONIGHT AND TOMORROW...WITH THE HIGHEST RAIN CHANCES IN THE
AFTERNOON DURING PEAK HEATING. WITH THE CAPPING INVERSION ALL BUT
GONE ON THURSDAY...ANY STORMS THAT GO UP COULD BECOME STRONG WITH
GUSTY WINDS AND PERHAPS EVEN SMALL HAIL POSSIBLE.
TEMPERATURES TODAY ARE ONCE AGAIN EXPECTED TO TOP OUT IN THE LOWER
80S...WHICH IS WELL ABOVE NORMAL FOR THIS TIME OF YEAR. TEMPERATURES
ON THURSDAY LOOK BE JUST A BIT COOLER DUE AS A SLIGHTLY COOLER AND
DRIER AIR MASS INVADES THE AREA BEHIND A SLOWLY DEPARTING COLD FRONT.
HIGHS ON THURSDAY WILL STILL LIKELY MAX OUT AT AROUND 80 DEGREES
ACROSS THE AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 358 AM EDT WED MAY 21 2014
THE MODELS REMAIN IN GOOD AGREEMENT THROUGH THE LONG TERM...WITH
A BLOCKY PATTERN TO DOMINATE ACROSS THE CONUS. AN UPPER LEVEL LOW
WILL START OFF ACROSS SOUTHERN CALIFORNIA...WITH BROAD TROUGHING
ACROSS SOUTHEASTERN CANADA AND NEW ENGLAND. AN UPPER LEVEL RIDGE
WILL EXTEND ACROSS THE CENTER PART OF THE COUNTRY...STEMMED FROM THE
HIGH CENTER LOCATED NEAR THE FLORIDA PANHANDLE. THE HIGH WILL GET
SUPPRESSED FURTHER SOUTH AND SOUTHWEST INTO THE GULF OF MEXICO...AS
TROUGHING DEEPENS ACROSS NEW ENGLAND INTO THE WEEKEND. THE RESIDUAL
RIDGE AXIS WILL THEN SLOWLY SLIDE EASTWARD INTO THE MISSISSIPPI
VALLEY THROUGH THE HOLIDAY WEEKEND...AS THE CALIFORNIA UPPER LEVEL
LOW SLOWLY CHURNS ITS WAY INTO THE SOUTHERN PLAINS.
THURSDAY NIGHT WILL FEATURE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS EXITING THE SOUTHERN HALF OF THE FORECAST AREA...A FEW
OF WHICH COULD APPROACH SEVERE LIMITS BEFORE DIMINISHING. COOLER AND
DRIER AIR WILL MOVE IN FOR FRIDAY AND SATURDAY ACROSS EASTERN
KENTUCKY...WITH HIGHS GETTING KNOCKED BACK INTO THE MID 70S...WHILE
LOWS BOTTOM OUT IN LOW TO MID 50S FOR MOST LOCATIONS. THE UPPER LEVEL
RIDGE WILL THEN BUILD INTO THE AREA FOR THE SECOND HALF OF THE
HOLIDAY WEEKEND...WITH HIGHS RETURNING TO THE MID 80S BY MEMORIAL
DAY. ENOUGH MOISTURE MAY RETURN BY MONDAY TO ALLOW FOR ISOLATED
CONVECTION ALONG PORTIONS OF THE CUMBERLAND VALLEY. SCATTERED
CONVECTION WILL THEN THREATEN THE ENTIRE AREA BY TUESDAY...AS THE
RIDGE AXIS EDGES JUST OFF TO THE EAST AND ALLOWS FOR BETTER MOISTURE
RETURN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 220 PM EDT WED MAY 21 2014
CONDITIONS ARE CURRENTLY VFR THROUGH THE AREA...BUT CIGS ARE NEAR
MVFR IN THIS HUMID ENVIRONMENT. CONVECTION IS EXPECTED LATER THIS
EVENING THROUGH THE ENTIRE FORECAST AREA WITH A POTENTIAL FOR
ORGANIZED AND UPSCALE DEVELOPMENT. INITIALLY...HAVE TIMED A
CONVECTIVE EVENT THROUGH THE TAF SITES DURING THE MID EVENING BASED
ON THE LATEST HRRR. HAVE LEFT VCTS IN THE TAFS FOR THE REST OF
THE NIGHT DUE TO A CONTINUED POTENTIAL FOR REDEVELOPMENT ALONG WITH
MVFR CIGS. THERE WILL LIKELY BE A LULL AND BETTER CONDITIONS FOR A
TIME EARLY IN THE MORNING OF THURSDAY...BUT FOR NOW WILL LEAVE THE
VCTS AND LOWER CIGS PREVAILING. WINDS WILL BE BREEZY FROM THE WEST
SOUTHWEST THROUGH THE EVENING WITH GUSTS TO 20 AND 25 KTS...BUT
CLOSER TO 35 KTS...OR HIGHER...WITH ANY STORMS THIS EVENING. WEST
WINDS OF 10 TO 20 KTS FOLLOW THROUGH THE REMAINDER OF THE TAF PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...AR
LONG TERM...GEOGERIAN
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
102 PM EDT WED MAY 21 2014
.AVIATION...
//DISCUSSION...
A COLD FRONT NOW OVER WRN LOWER MI AND WEAK WARM FRONTAL FEATURE NOW
LOCATED BETWEEN FNT AND MBS WILL BE THE TRIGGER FOR SCATTERED TO
POSSIBLY NUMEROUS THUNDERSTORM COVERAGE LATE THIS AFTERNOON. THE
COLD FRONT IS EXPECTED TO MOVE FROM EAST TO WEST ACROSS SE MI
BETWEEN 21Z AND 00Z. INCREASING INSTABILITY IN ADVANCE OF THIS FRONT
WILL HELP FUEL THE THUNDERSTORMS. GIVEN THE TIMING OF THE
FRONT...THERE IS REASONABLE CONFIDENCE THAT THE COVERAGE OF STORMS
LATE THIS AFTERNOON WILL BE ENOUGH TO JUSTIFY A TWO TO THREE HOUR
PERIOD OF THUNDERSTORMS IN THE TAFS. THE EXCEPTION WILL BE MBS WHERE
THE EARLIER FROPA MAY NOT ALLOW ENOUGH TIME FOR THUNDERSTORM
DEVELOPMENT. OBSERVATIONS SUGGEST THAT DAYTIME HEATING IS LIFTING
THE BASES OF THE MVFR STRATO CU FIELD...SUGGESTING BASES WILL LIKELY
FALL INTO THE 3500 TO 4500 FT RANGE PRIOR TO FROPA.
FOR DTW...THE FRONT SHOULD PUSH ACROSS METRO BETWEEN 22 AND 23Z. IT
REMAINS UNCLEAR JUST HOW EXTENSIVE THUNDERSTORM COVERAGE WILL BE AS
THERE IS LIKELY TO BE A CAPPING INVERSION PRESENT. THERE IS STILL A
POTENTIAL FOR STRONG STORMS LATE THIS AFTERNOON/EARLY EVENING WHICH
COULD IMPACT A GOOD PORTION OF METRO AIRSPACE.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE FOR THUNDERSTORMS BETWEEN 21Z AND 23Z.
* MEDIUM CONFIDENCE IN CEILING BELOW 5000 FEET THIS AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 1106 AM EDT WED MAY 21 2014
UPDATE...
A REGION OF MID LEVEL SUBSIDENCE IN THE WAKE OF THE EARLY MORNING
THUNDERSTORM COMPLEXES HAS ESSENTIALLY SHUT DOWN CONVECTION THIS
MORNING. A LINGERING RESERVOIR OF LOW LEVEL MOISTURE OVER SOUTHERN
MICHIGAN HAS BEEN ALLOWING THE RAPID DEVELOPMENT OF STRATO CU AS
DIURNAL HEATING HAS KICKED IN. COVERAGE AND INTENSITY OF
AFTERNOON/EVENING THUNDERSTORMS WILL BE PREDICATED UPON HOW WELL
DIURNAL MIXING ERODES SOME OF THESE LOW CLOUDS AND WEAKENS A MID
LEVEL CAP. THE 14Z SURFACE ANALYSIS SHOWS AN ELONGATED REGION OF
LOW PRESSURE OVER SRN LOWER MI WITH AN ENHANCED REGION OF
CONVERGENCE ALONG A SFC TROUGH OVER THE WRN LAKE MI SHORELINE. THE
12Z NAM/RAP/HRR ALL SHOW THIS BOUNDARY ADVANCING INTO SE MI THIS
AFTERNOON...WHILE A MORE E-W ORIENTED BOUNDARY NOTED JUST SOUTH OF
THE I-69 CORRIDOR REMAINS NEARLY STATIONARY. THE LOW LEVEL WIND
FIELD MAY ALSO REMAIN WEAK ENOUGH TO ALLOW SOME LAKE BREEZE
DEVELOPMENT ALONG THE LAKES HURON/ST CLAIR/ERIE SHORELINES. THESE
BOUNDARIES WILL BE THE MAIN FOCUS FOR CONVECTIVE INITIATION LATER
TODAY. 12Z UPSTREAM RAOBS DO SUPPORT MODEL SOLUTIONS IN SHOWING A
WEDGE OF MID LEVEL DRY ACROSS THE UPPER MIDWEST. THIS OTHER REGION
OF MID LEVEL SUBSIDENCE AND PUSH OF DRY AIR IS EXPECTED TO ADVANCE
INTO SE MI BETWEEN 21Z AND 00Z. THE CONCERN IS WHETHER THERE WILL
BE ENOUGH INSTABILITY TO OVERCOME THE CAP PRIOR TO THE ARRIVAL OF
THIS REGION OF SUBSIDENCE.
SFC DEWPOINTS HAVE BEEN RISING WITH THE ONSET OF DAYTIME
HEATING...A SIGN OF RESPECTABLE LOW LEVEL MOISTURE DEPTH. THUS
MODEL SOUNDINGS AND THE MODIFIED 12Z DTX SOUNDING SUGGESTIVE OF
0-1KM ML CAPE OF 1500-2K J/KG SEEM REASONABLE IF SFC TEMPS CAN
PUSH 80 DEG THIS AFTERNOON. 0-6KM BULK SHEAR UP TO 40 KNOTS AND MID
LEVEL DRY AIR ADVECTION RAISES CONCERNS FOR SEVERE STORM POTENTIAL
LATER TODAY. THE SHEAR/INSTABILITY COMBINATION WILL BE FAVORABLE TO
BOTH SUPERCELLS AND LINEAR MODES OF CONVECTION...WITH DAMAGING
WIND GUSTS AND LARGE HAIL A CONCERN. SINCE THE COVERAGE AND
SEVERITY OF CONVECTION WILL RELY ON THE DEGREE OF AFTERNOON
DESTABILIZATION AND MID LEVEL CAP STRENGTH...AN 18Z DTX SOUNDING
WILL BE DONE TODAY.
PREV DISCUSSION...ISSUED 343 AM EDT WED MAY 21 2014
SHORT TERM... TODAY AND TONIGHT
SURFACE AND MODEL ANALYSIS FIELDS PROVIDE A STRAIGHTFORWARD
DIAGNOSIS FOR ONGOING CONVECTIVE FORCING BUT THAT STILL LEAVES A
CHALLENGING FORECAST FOR WHAT MAY FOLLOW LATER TODAY THROUGH THIS
EVENING UNTIL THE SURFACE COLD FRONT PUSHES THROUGH THE REGION
CLOSER TO MIDNIGHT.
THE LARGE SCALE PATTERN IS ANCHORED BY A LOW PRESSURE SYSTEM MOVING
THROUGH NORTHERN ONTARIO WHICH HAS AN OCCLUDED FRONT EXTENDING INTO
A BROADER SURFACE WAVE OVER LOWER MICHIGAN RIPPLING ALONG THE MAIN
WARM/STATIONARY FRONT EXTENDING INTO OUR AREA. THE LOW LEVEL
MOISTURE AXIS IS ALIGNED ALONG THIS SURFACE PRESSURE FEATURE WITH
BACKGROUND VERTICAL MOTION SUPPLIED BY AGEOSTROPHIC CIRCULATION
UNDER THE SOUTH FLANK OF THE UPPER JET. THE RESULT IS CONTINUED
SUPPORT FOR ONGOING CONVECTION AND DEVELOPMENT OF ADDITIONAL SHOWERS
AND WEAKER STORMS NORTH OF THE SURFACE BOUNDARY. SINCE MIDNIGHT...
CONCERN HAS TRANSITIONED FROM SEVERE WEATHER POTENTIAL NEAR THE OHIO
BORDER TO EXCESSIVE RAINFALL THROUGH THE I-69 CORRIDOR...ALTHOUGH
INTENSITY OF STORMS WILL REMAIN STRONG NEAR THE OHIO BORDER WHERE
MID LEVEL LAPSE RATES ARE GREATEST. AT THE SAME TIME...EXPECT
COVERAGE OF SHOWERS AND STORMS WILL BE NUMEROUS FARTHER NORTH WITHIN
THE FRONTAL CIRCULATION IN THE 850-700 MB LAYER. BASED ON MODEL MEAN
RH TRENDS...THERE IS GOOD AGREEMENT THAT THIS CLUSTER OF CONVECTION
WILL MOVE EAST OF THE AREA AROUND NOON.
OTHER THAN A SLOW PROGRESSION OF THE SURFACE PRESSURE PATTERN...
THERE WILL NOT BE MUCH DIFFERENCE IN THE LARGE SCALE FEATURES
AFFECTING THE AREA DURING THE AFTERNOON COMPARED TO THE CURRENT
SETUP. THE CONSENSUS OF MODEL MSL PRESSURE SOLUTIONS PLACES THE
TRIPLE POINT OF THE OCCLUSION OVER NORTHERN LOWER MICHIGAN AROUND
18Z. SOUTHWEST FLOW RETURNING BEHIND THE MORNING CONVECTIVE PATTERN
WILL BE ADEQUATE TO MAINTAIN THUNDERSTORM POTENTIAL WITH SUFFICIENT
RECOVERY OF INSTABILITY. THE TIMING AND MAGNITUDE OF RECOVERY IS THE
MAIN UNCERTAINTY IN THE FORECAST AND SEVERE WEATHER POTENTIAL.
REASONABLE DOWNWARD ADJUSTMENTS TO THE LATEST NAM AND RAP OUTPUT
STILL OFFERS 0-1KM MLCAPE RECOVERING TO ABOUT 1500 J/KG MID TO LATE
AFTERNOON...BUT WITH MODEST MID LEVEL LAPSE RATES OF 6-7C/KM IN THE
700-500 MB LAYER AS THE EML SUPPORTING THE EARLY MORNING STORMS IS
DIRECTED INTO THE UPPER OHIO VALLEY. REMAINING IN PLACE WILL BE THE
SOUTHERN FRINGES OF DYNAMIC SUPPORT FROM THE UPPER WAVE OVER
NORTHERN ONTARIO...AND STRONG WESTERLY FLOW ALOFT OVER LOWER
MICHIGAN. MODEL SOUNDINGS INDICATE A SOLID STRAIGHT-LINE HODOGRAPH
ANCHORED BY 50-60 KNOTS OF FLOW AROUND 500 MB AND 0-6 KM BULK SHEAR
AROUND 50 KNOTS. DIFFERENT FROM YESTERDAY WILL BE A MORE VEERED LOW
LEVEL FLOW WHICH IS LESS FAVORABLE FOR TORNADOGENESIS...BUT THE
OVERALL PROFILE IS STILL SUPPORTIVE OF STORM SPLITS/SUPERCELL
ORGANIZATION EARLY IN THE CONVECTIVE CYCLE. PLAN TO CALL FOR
ISOLATED STORMS APPROACHING SEVERE LIMITS UNTIL SEVERE POTENTIAL CAN
BE REFINED WITH OBSERVATIONS AS THE DAY PROGRESSES. SHOWERS AND
WEAKER STORMS SHOULD OTHERWISE BECOME NUMEROUS BY LATER AFTERNOON
THROUGH THE EVENING BEFORE THE COLD FRONT SWEEPS EVERYTHING OUT OF
THE REGION AROUND MIDNIGHT.
LONG TERM...
COLD ADVECTION PATTERN EMBEDDED WITHIN CORRIDOR OF CYCLONIC
NORTHWEST FLOW ALOFT WILL PERSIST INTO FRIDAY MORNING. H85
TEMPERATURES ARE PROGGED TO FALL FROM 10C LATE TONIGHT TO 4C FRIDAY
MORNING. ONGOING COLD ADVECTION WILL ENSURE STEEP LOW-LEVEL LAPSE
RATES CAPABLE OF SUPPORTING EXPANSIVE AFTERNOON STRATOCU,
PARTICULARLY IN THE PRESENCE OF LOW AMPLITUDE DISTURBANCES RIPPLING
ALONG IN THE FLOW ALOFT. INFLUX OF THE COOLER AIRMASS COMBINED WITH
CLOUDS DEVELOPING DURING PEAK HEATING WILL LIMIT HIGHS TO THE
MID/UPPER 60S ON BOTH FRIDAY AND SATURDAY. HIGH AMPLITUDE RIDGE WILL
VERY GRADUALLY MIGRATE OVER THE GREAT LAKES THROUGH THE HOLIDAY
WEEKEND AS THE PATTERN SLOWS IN RESPONSE TO THE CLOSED LOW OVER THE
SOUTHWEST UNITED STATES. REBOUNDING THERMAL PROFILES WILL BE
ACCOMPANIED BY DEEP LAYER SUBSIDENCE, ADDING CONFIDENCE TO THE
FORECAST FOR A WARM AND MOSTLY SUNNY HOLIDAY WEEKEND. TEMPERATURES
WILL MODERATE FROM LOW/MID 70S ON SATURDAY TO THE LOW 80S BY MONDAY.
MARINE...
A WEAK COLD FRONT WILL SWING THROUGH THE CENTRAL GREAT LAKES THIS
AFTERNOON. BRISK NORTHWEST WINDS WILL THEN BUILD IN FOR TONIGHT AND
THURSDAY. ANY THUNDERSTORMS WHICH DEVELOP TONIGHT THROUGH TOMORROW
MAY BE STRONG TO SEVERE. LIGHT WINDS WILL RETURN FOR THE WEEKEND AS
HIGH PRESSURE SETTLES OVER THE AREA.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SC
UPDATE.......SC
SHORT TERM...BT
LONG TERM....JVC
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DULUTH MN
303 PM CDT WED MAY 21 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 302 PM CDT WED MAY 21 2014
CLOUDS HAVE BEEN VERY SLOW TO DIMINISH OVER THE NORTHLAND TODAY
UNDER COOL NORTHWESTERLY FLOW ALOFT. THEY ARE STARTING TO THIN TO
OUR SOUTHWEST...AND THAT TREND WILL CONTINUE OVERNIGHT. WE DID
INCREASE CLOUDS THIS EVENING FOR MOST AREAS...FOLLOWING CLOSE TO
THE RAP LOW LEVEL MOISTURE FIELDS. THE LATEST RAP ALSO SHOWS
CLOUDS HANGING IN FOR MUCH OF THE NIGHT OVER THE NORTHEAST HALF TO
TWO THIRDS OF THE CWA. WE WILL MONITOR CLOUD TRENDS TONIGHT AND
WE MAY NEED TO BEEF UP CLOUDS AND ADJUST LOWS UP.
WE BUMPED UP CLOUDS A BIT ON THURSDAY AND WENT WITH PARTLY CLOUDY
SKIES. WE THINK THERE COULD BE CLOUDS AROUND EARLY AND WE SHOULD
DEVELOP SOME CU THROUGH THE DAY. AT THE SURFACE...HIGH PRESSURE
WILL BE OVERHEAD BUT TEMPS WILL STILL BE COOL ALOFT.
HIGH PRESSURE WILL CONTINUE TO IMPACT THE REGION AND PROVIDE DRY
CONDITIONS INTO FRIDAY. TEMPERATURES WILL WARM FROM THE SIXTIES
THURSDAY INTO THE SEVENTIES FOR MOST AREAS ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 302 PM CDT WED MAY 21 2014
THE EXTENDED PERIOD FROM FRIDAY NIGHT THROUGH NEXT WEDNESDAY FINALLY
LOOKS TO BE A SUSTAINED PERIOD OF AT OR ABOVE NORMAL TEMPS ACROSS
MOST OF THE REGION. WHILE AREAS NEAR LAKE SUPERIOR WILL LIKELY SEE
RATHER ROBUST LAKE BREEZE FRONTS DURING THE MIDDAY TO EVENING HOURS
SAT-MON TIME FRAME..THE REMAINDER OF THE DULUTH CWA SHOULD SEE HIGH
TEMPS WELL INTO THE 70S..ALONG WITH DEWPOINTS REACHING INTO THE 60S
BY THE MON-WED TIME FRAME.
SURFACE AND MID LEVEL RIDGE AXIS SHOULD BE OVER THE CWA NEAR THE
BEGINNING OF THE PERIOD FRI NIGHT/SAT..BRINGING A COOL MORNING.
HOWEVER..RETURN SOUTH/SOUTHEAST FLOW SHOULD DEVELOP IN MOST AREAS BY
MIDDAY SAT..WITH BEST CHANCES FOR RAIN SHOWERS REMAINING TO OUR WEST
UNTIL LATER IN THE DAY. RATHER ROBUST DIFFERENTIAL HEATING SHOULD
RESULT IN A FAIRLY STRONG LK SUPERIOR LAKE BOUNDARY DURING THE
AFTERNOON..WITH HIGH TEMPS OCCURRING LATE MORNING TO EARLY AFTERNOON
IN THE FAVORED LAKE BREEZE LOCATIONS. GIVEN THAT LOW LEVEL FLOW WILL
LIKELY STILL HAVE SOME EASTERLY COMPONENT..THERE SEEMS TO BE
POTENTIAL FOR ANY LAKE BREEZE BOUNDARY TO PENETRATE RATHER FAR
INLAND BY LATE AFTERNOON SATURDAY..WITH SOME COOLING EFFECT POSSIBLY
NOTED AS FAR WEST AS THE GRAND RAPIDS/IRON RANGE/INTERIOR ARROWHEAD
AREAS BY EVENING.
CHANCES FOR SHOWERS/TSTORMS WILL INCREASE FROM WEST TO EAST LATE SAT
INTO MONDAY AS NORTHERN STREAM WAVE PUSHES A WEAK FRONT INTO THE NE
MN AREA..BEFORE THE FRONT STALLS AND/OR WASHES OUT EARLY NEXT WEEK.
THE LARGE SOUTHERN STREAM UPPER LOW TRAVERSING THE PLAINS STATES TO
OUR SOUTH DURING THIS TIME AND PRECIPITATION/DEEP CONVECTION
ASSOCIATED WITH IT MAY ACT TO LESSEN THE NORTHWARD LOW LEVEL
MOISTURE TRANSPORT. HOWEVER..SUFFICIENT MOISTURE IS EXPECTED TO BE
IN PLACE TO SUPPORT SOME SHOWERS/STORMS IN VICINITY OF THE LINGERING
BOUNDARY FROM SAT NIGHT INTO MONDAY. AT THIS TIME..IT APPEARS THAT
INSTABILITY AND ESPECIALLY WIND SHEAR/FLOW WILL BE TOO WEAK TO
SUPPORT MUCH IN THE WAY OF ANY SEVERE WEATHER POTENTIAL. AGAIN..WE
EXPECT A LK SUPERIOR LAKE BREEZE FRONT TO DEVELOP SUN-MON AS
WELL..RESULTING IN LATE MORNING/EARLY AFTERNOON HIGH TEMPS IN AREAS
NEAR THE LAKE.
BY MID WEEK..A RATHER SIGNIFICANT LARGE SCALE PATTERN SHIFT TO A
PACNW UPPER TROF AND BROAD WSW MID LEVEL FLOW FROM THE GREAT BASIN
TO MANITOBA/NW ONTARIO SHOULD RESULT IN THE BUILDING OF A LOW LEVEL
THERMAL RIDGE FROM THE DAKOTAS INTO NW MINNESOTA. WHILE THE BEST
FLOW AND SHEAR AS WELL AS INSTABILITY AXIS IS EXPECTED TO REMAIN TO
OUR WEST BASED ON CURRENT GUIDANCE..THERE WILL STILL BE POTENTIAL FOR
SOME ELEVATED STORMS WITHIN THE LOW LEVEL WARM/MOIST ADVECTIVE ZONE
JUST DOWNSTREAM FROM THE MAIN UPPER LEVEL RIDGE AXIS ACROSS THE
DULUTH CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1230 PM CDT WED MAY 21 2014
HIGH END IFR TO LOW END MVFR CONDITIONS AT INL WILL GRADUALLY
IMPROVE LATER THIS AFTERNOON. MVFR CONDITIONS AT HIB AND BRD WILL
BECOME VFR BY 22Z. DLH AND HYR SHOULD REMAIN VFR THROUGH THE TAF
PERIOD. SOME WIND GUSTS UP TO 20 KNOTS FROM THE NORTHWEST WILL BE
OVER THE TAF SITES THROUGH LATE AFTERNOON. INCLUDED VCSH AT
INL...HIB AND DLH FOR AN ISOLATED RAIN SHOWER THROUGH 0Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 42 65 43 69 / 10 0 0 0
INL 40 61 40 73 / 10 0 0 10
BRD 41 70 43 75 / 0 0 0 10
HYR 41 66 39 73 / 10 0 0 0
ASX 42 64 39 68 / 10 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE
LONG TERM...MILLER
AVIATION...KK
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
341 PM CDT Wed May 21 2014
.SHORT TERM: (Through Late Tonight)
Issued at 1256 PM CDT Wed May 21 2014
Cold front extended from just north of UIN southwest through MCI.
This front will move southward through our forecast area tonight, and
should extend from west central MO southeast through southern IL by
12z Thursday. The cap should break late this afternoon with
scattered convection developing along this front. The HRRR model
has most of the convection across northeast MO and west central IL
early this evening, then shifts it southward with most of the
convection from around COU east through the St Louis metro area to
Vandalia and Salem IL by midnight. Some of these storms may be
severe due to very unstable conditions late this afternoon and this
evening with CAPEs of 2000-3000 J/Kg and surface LI values as low as
-10 south of the cold front. Low-mid level shear will also be
relatively strong with 500 mb wind speeds of up to 50 kts due to a
500 mb wind max moving through the Great Lakes region.
GKS
.LONG TERM: (Thursday through Next Wednesday)
Issued at 340 PM CDT Wed May 21 2014
The cold front will continue to sag slowly southward as a surface
ridge shifts eastward from the northern Plains into the Great Lakes
region. At least scattered convection is expected along and just
behind this front as weak shortwaves move east southeastward through
our area over the mid-upper level ridge centered over the Gulf Coast
states. The best coverage of convection should be across central
and southeast MO Thursday and Thursday night as the front becomes
more nw to se oriented. The ECMWF model appears to be a little too
far north with its qpf from Thursday afternoon into Friday morning.
Cooler and drier air will advect into the region behind the cold
front, particularly across northeast MO and west central IL.
The mid-upper level low now over NV will move slowly through the
southwest US. Weak shortwaves will eject northeastward from this
feature and bring more convection mainly to the western portion of
our forecast area Saturday and Saturday night with the upper level
ridge along with the surface ridge centered over the Great Lakes and
Ohio Valley regions keeping the eastern portion of our forecast area
dry. The mid-upper level low will eventually move into the Plains
by Monday. The models have varying solutions after this with the
ECMWF model moving it into MO by Tuesday, while the GFS model
weakens it and has it passing south of our area. With this model
uncertainty will just include chance pops for early next week,
although there may be more widespread showers/storms for Monday
night and Tuesday. Always difficult to forecast the exact path,
strength and speed of upper level lows coming out of the southwest
US.
GKS
&&
.AVIATION: (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1214 PM CDT Wed May 21 2014
Cold front over northwestern Missouri will continue to sag
southward today into this evening, reaching KUIN by around 03Z,
then pushing into KCOU and KSTL metro TAF sites by 05Z. Unstable
airmass ahead of the front may fuel scattered thunderstorms this
afternoon into early evening, however coverage is uncertain so
will address in the TAFS with several hours of VCTS and update
frequently as the situation becomes more clear. Any storms should
diminish overnight with loss of strong daytime heating. VFR
conditions expected otherwise on Wednesday with winds veering to
northeast.
Specifics for KSTL: Scattered thunderstorms may form near
approaching cold front from 23Z until around 05Z. Coverage is
uncertain however and may be rather limited, so handled in the TAF
with a VCTS. Otherwise expect VFR conditions. Surface winds will
back from west this afternoon through north with frontal passage
around 05Z, then become northeast.
Browning
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
308 PM CDT Wed May 21 2014
.SHORT TERM...(This Evening through Thursday Night)
Issued at 305 PM CDT WED MAY 21 2014
The focus through the period continues to be on thunderstorms
chances. For this afternoon the frontal boundary currently slowly
moving south across portions of the NRN CWA should serve as the
focus for isolated to scattered storms. Dprog/Dt of the HRRR paints
a narrow zone of storms along the front forming by 5 to 6 pm in our
CWA, then they move east and clear the CWA by around 9 or 10 pm.
Latest ACARS soundings out of KMCI depict the CAP slowly eroding so
confidence is rather high we should see a few storms along the
front. Given the large CAPE and modest shear profiles large hail
and damaging winds will be the main threats.
Late overnight tonight a large complex of storms may work into the
CWA from the west/southwest. At this time the better chances of
seeing storms appears to favor the WRN and NRN areas of the CWA.
The complex of storms should be weakening as they move in, thus the
overnight SVR potential is rather low.
Tomorrow most of the CWA will be north of the surface front so high
temps should be back down to near normal... mid to upper 70s with
mid 80s across our far SRN zones. Precip wise is a tough call depending
on how long any overnight activity lingers into the daylight morning
hours, residual cloud debris and degree of instability. So for now
just have low chance pops through tomorrow into tomorrow evening
given a lack upper level forcing.
.LONG TERM...(Friday through Wednesday)
Issued at 305 PM CDT WED MAY 21 2014
A rather messy short to medium range forecast through the Memorial
Day holiday and into much of next week. Why? The development of
the cutoff low across the southwestern United States that will
slowly crawl eastward into early next week. This low is expected to
pull increasing amounts of low-mid level moisture northward into the
Plains which will interact with a stalled frontal boundary in the
region.
By Friday morning, precipitation chances will increase briefly as a
secondary shortwave drops through the Great Lakes and a brief window
of warm advection commences overnight. This upper trough will push surface
high pressure into the region, and force the stalled front well
south of the area, potentially forcing precip south and east of the
CWA Friday afternoon and evening.
It`s hard to get too specific on forecast details through this
weekend and into Monday due to shortwave timing issues. The weekend
shouldn`t be a washout, but we`ll have to carry scattered PoP
wording through Monday.
Medium range models are all over the place in the eventual track of
the upper low through the area through Thursday. ECMWF/GEM produces
fairly widespread rains for Monday and Tuesday with a northern track,
GFS dives the ejecting low too far south to produce widespread rains,
but more scattered activity. Ensemble approach provides little
benefit, with a substantial spread in solutions. For now, have to
continue to include PoPs through much of the extended.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1208 PM CDT WED MAY 21 2014
VFR CIGS and VIS are planned through the period at all three
terminals. The issue will be whether scattered storms develop near
the terminals late this afternoon along a cold front that is
currently sliding south into the region. CIGS/VIS may dip down to
MVFR if a storm does pass over a terminal, but those conditions should
not last long. Late tonight more organized storms may move in from
the west approaching the terminals before clearing out by mid-
morning. Will try to time out better the overnight activity with the
00Z TAF issuance as confidence may be greater on location and
coverage by that time.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...Pietrycha
LONG TERM...Dux
AVIATION...Pietrycha
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
101 PM CDT Wed May 21 2014
.SHORT TERM: (Through Late Tonight)
Issued at 1256 PM CDT Wed May 21 2014
Cold front extended from just north of UIN southwest through MCI.
This front will move southward through our forecast area tonight, and
should extend from west central MO southeast through southern IL by
12z Thursday. The cap should break late this afternoon with
scattered convection developing along this front. The HRRR model
has most of the convection across northeast MO and west central IL
early this evening, then shifts it southward with most of the
convection from around COU east through the St Louis metro area to
Vandalia and Salem IL by midnight. Some of these storms may be
severe due to very unstable conditions late this afternoon and this
evening with CAPEs of 2000-3000 J/Kg and surface LI values as low as
-10 south of the cold front. Low-mid level shear will also be
relatively strong with 500 mb wind speeds of up to 50 kts due to a
500 mb wind max moving through the Great Lakes region.
GKS
.LONG TERM: (Tonight through Tuesday)
Issued at 315 AM CDT Wed May 21 2014
Expect very slow southward progress of the boundary until tonight
and tomorrow when a 1020-1025 hPa surface high slides from Canada
into the western Great Lakes, pushing the front farther to the
south and southwest. At first glance, environmental parameters for
Thu look similar to Wed: H7-H5 lapse rates of 6.5-7 deg C/km and
40-50 kts of 0-6 km shear. However, the higher shear values are
much less widespread on Thu and are not as favorably located
relative to the position of the boundary. If the models are
correct in advancing the front into southwest MO by Thu afternoon,
then the overall thunderstorm coverage across the LSX CWA would
probably be lower on Thu afternoon compared to Wed, and the chance
for widespread severe thunderstorms would also be lower. The best
chance for thunderstorms would be across the western part of the
CWA, closer to the boundary and to the juicier moisture pooled
along and south of it.
The boundary becomes reoriented but remains over the region
through the weekend, eventually lifting back northeastward as a
warm front on Sat/Sun. Several vorticity maxima are forecast to
move across the region during this time and may interact with the
front to produce periods of showers and thunderstorms. Models are
in broad agreement that a large closed low pressure system over
the desert southwest will lift into the plains and then move
eastward across MO/IL early next week, but some placement/timing
differences remain in the 00z GFS/ECMWF. Additional periods of
SHRA/TSRA are expected with this system, but it would not be
surprising if the preferred timing for the system`s passage across
MO/IL changes a few times over the next several days.
Kanofsky
&&
.AVIATION: (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1214 PM CDT Wed May 21 2014
Cold front over northwestern Missouri will continue to sag
southward today into this evening, reaching KUIN by around 03Z,
then pushing into KCOU and KSTL metro TAF sites by 05Z. Unstable
airmass ahead of the front may fuel scattered thunderstorms this
afternoon into early evening, however coverage is uncertain so
will address in the TAFS with several hours of VCTS and update
frequently as the situation becomes more clear. Any storms should
diminish overnight with loss of strong daytime heating. VFR
conditions expected otherwise on Wednesday with winds veering to
northeast.
Specifics for KSTL: Scattered thunderstorms may form near
approaching cold front from 23Z until around 05Z. Coverage is
uncertain however and may be rather limited, so handled in the TAF
with a VCTS. Otherwise expect VFR conditions. Surface winds will
back from west this afternoon through north with frontal passage
around 05Z, then become northeast.
Browning
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
322 PM CDT WED MAY 21 2014
.SYNOPSIS...
ISSUED AT 322 PM CDT WED MAY 21 2014
A FAIRLY STAGNANT UPPER LEVEL PATTERN WAS NOTED ACROSS
THE LOWER 48 THIS MORNING. WITH THE EXCEPTION OF FLAGSTAFF AZ...NO
UA SITES HAD HT FALLS OR RISES IN EXCESS OF 50 METERS. THE MAIN
FEATURES OF NOTE ACROSS THE LOWER 48 WERE HIGH PRESSURE OVER THE
MISSISSIPPI DELTA...A STRONG SHORTWAVE OFF THE COAST OF MAINE...AND
A CLOSED LOW OVER NEVADA. A WEAK JET STREAK AROUND 50 KTS WAS NOTED
FROM NRN AZ INTO WESTERN COLORADO. A COUPLE OF WEAK SHORTWAVES WERE
NOTED EARLY THIS AFTERNOON ALONG THE WESTERN SLOPES OF
COLORADO...AND OVER EASTERN NEW MEXICO. THESE TWO DISTURBANCES HAVE
LED TO INCREASED CLOUD COVER OVER WESTERN COLORADO...WYOMING...AS
WELL AS EASTERN NEW MEXICO AND THE TX PANHANDLE. AT THE
SURFACE...HIGH PRESSURE HAS PUSHED INTO THE DAKOTAS AND NORTHERN
NEBRASKA THIS AFTERNOON...FORCING A FRONTAL BOUNDARY INTO THE TEXAS
PANHANDLE. THIS BOUNDARY THEN WINDS TO THE WEST NORTHWEST ALONG THE
FRONT RANGE OF COLORADO AND WYOMING. WITH EASTERLY AND NORTHEASTERLY
WINDS...UNDER CLEAR TO PARTLY CLOUDY SKIES...2 PM CDT TEMPERATURES
RANGED FROM 65 AT AINSWORTH...TO 75 AT IMPERIAL.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 322 PM CDT WED MAY 21 2014
WEAK PV ANOMALY MOVING NWD ALONG THE FRONT RANGE OF CO PER WV
IMAGERY SHOULD CONTINUE TO GENERATE SFC PRESSURE FALLS IN THE LEE OF
THE PALMER DIVIDE AND ENHANCE EXISTING UPSLOPE FLOW TO INITIATE TSRA
ALONG THE HIGHER TERRAIN INITIALLY...WITH ORGANIZED CONVECTIVE
MOVEMENT EXPECTED TO BE NORTHEASTWARD INTO WESTERN AND SW NEB. SHORT
RANGE MODEL FCST SOUNDINGS INDICATE SOME REMAINING...THOUGH
ELEVATED...INSTABILITY OVERNIGHT. HOWEVER MOISTURE IS NOT OVERLY
IMPRESSIVE FURTHER NORTHEAST INTO CENTAL NEBR SINCE NRLY/NERLY FLOW
AT THE SFC ADVECTING ONLY MID TO UPPER 40S DEW POINTS. IN THE
ABSENCE OF A WELL DEFINED LLJ CONVECTION WILL HAVE A DIFFICULT TIME
BEING SUSTAINED INTO CENTRAL NEBR...MUCH LIKE LAST FEW NIGHTS.
HOWEVER...SINCE ORGANIZED CONVECTION WILL LIKELY BE MORE WIDESPREAD
IT MAY HAVE BETTER POTENTIAL. SHORT RANGE MODELS CURRENTLY ARE IN
DISAGREEMENT WITH THIS. HRRR ENSEMBLE UPDRAFT HELICITY SUGGESTS
ORGANIZATION OF INDIVIDUAL UPDRAFTS WOULD WEAKEN AS ANY REMAINING
STORMS MOVE INTO SW NEB. HARD TO ASSESS POTENTIAL FOR SVR...MODELS
SOUNDINGS SHOW SOME CAPE IN THE LOWER RANGE OF THE HAIL GROWTH
REGION...STILL BETTER POPS ARE INCLUDED TONIGHT MOST AREAS THAN PREV
NIGHTS.
WOULD EXPECT A SIMILAR SCENARIO THURSDAY MORNING AS WITH LAST COUPLE
OF MORNINGS IN THAT CONVECTIVE DEBRIS WILL REMAIN ACROSS SOME
PORTIONS OF THE CWA...THOUGH PINPOINTING WHERE IS DIFFICULT.
THEREFORE POPS INCLUDED PRIMARILY WHERE ELEVATED INSTABILITY
RESIDES. UPPER LOW OVER THE SOUTHWEST MOVES LITTLE BUT PIVOTS TO
BECOME SLIGHTLY NEGATIVELY TILTED THURS AFTERNOON. AS A RESULT WINDS
SHOULD BECOME MORE SOUTHEASTERLY AND ADVECT BETTER MOISTURE BACK
INTO THE AREA. FEEL MORE ORGANIZED CONVECTION THURSDAY SHOULD AGAIN
ENTER WESTERN NEB AFTER 00Z FRI. HIGHS WILL BE TEMPERED SOME BY
CLOUD COVER EARLY...BUT SHOULD RECOVER IN THE AFTERNOON MUCH LIKE
TODAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 322 PM CDT WED MAY 21 2014
FOR THURSDAY NIGHT THROUGH SATURDAY...PRECIPITATION CHANCES CONTINUE
TO BE THE MAIN FORECASTING CHALLENGE IN THE MID RANGE PERIODS. LIKE
THIS AFTERNOON...THUNDERSTORMS ARE EXPECTED TO BE ONGOING BY
THURSDAY EVENING OVER NERN COLORADO AND NWRN KS INVOF OF A STALLED
OUT FRONTAL BOUNDARY. WEAK SOUTHERLY AND SSWRLY STEERING WINDS WILL
LIFT THIS ACTIVITY NORTH INTO WESTERN NEBRASKA THURSDAY EVENING. AS
HAS BEEN THE CASE OVER THE PAST COUPLE OF NIGHTS...THIS ACTIVITY HAS
WEAKENED SUBSTANTIALLY AS IT MOVES INTO THE FORECAST AREA FROM THE
WEST AND SOUTHWEST. HOWEVER...TOMORROW NIGHT INTO FRIDAY...LOW LEVEL
WINDS WILL SHIFT MORE TO THE SOUTHEAST AS SURFACE HIGH PRESSURE
LIFTS INTO THE UPPER MISSISSIPPI VALLEY THIS SHIFT IN THE WIND
DIRECTION WILL SERVE TWO PURPOSES...A INCREASE LOW LEVEL
MOISTURE-BRINGING DEW POINTS BACK INTO THE 50S AND B...LEAD TO A 20
TO 30 KT LOW LEVEL JET THURSDAY NIGHT...WHICH WILL HELP TO SUSTAIN
CONVECTION INTO THE LATE NIGHT HOURS. WITH THE FLOW BEING FAIRLY
WEAK IN THE MID LEVELS AND DEEP MID LAYER INSTABILITY BEING FAIRLY
MEAGER...DECIDED TO LEAVE POPS IN THE 30 TO 50 PERCENT RANGE AS
COVERAGE IS EXPECTED TO REMAIN SCATTERED. ON FRIDAY...THE FRONTAL
BOUNDARY WILL LIFT NORTH INTO SOUTHWESTERN AND WESTERN
NEBRASKA...ALLOWING SHOWERS AND THUNDERSTORMS TO LINGER DURING THE
DAYTIME HOURS. CAPPING ON FRIDAY IS WEAK PER THE LATEST NAM AND GFS
SOLNS...SO AFTERNOON HEATING DURING THE DAYTIME HOURS...WILL QUICKLY
LEAD TO ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT. IN
ADDITION...FCST QPF`S ARE EXPECTED TO BE THE HIGHEST FRIDAY/FRIDAY
NIGHT...GIVEN THE EXPECTED WEAK STEERING WINDS AND PWATS OF 1.25 TO
1.50 INCHES. WITH RESPECT TO SEVERE POTENTIAL FRIDAY...AT THIS
TIME...THE SEVERE THREAT FOR FRIDAY APPEARS TO BE MARGINAL GIVEN THE
WEAK MID LEVEL FLOW...ALONG WITH LITTLE OR NO CAP...WHICH WILL
PRODUCE COMPETING UPDRAFTS AND DISORGANIZED CLUSTERS OF STORMS. ON
SATURDAY...THE FRONTAL BOUNDARY WILL LIFT EAST INTO CENTRAL PORTIONS
OF THE FORECAST AREA...FORCED BY THE APPROACH OF THE UPPER LEVEL LOW
AND TROUGH...WHICH WILL REACH THE FOUR CORNERS BY 00Z SUNDAY. THOUGH
PCPN CHANCES REMAIN POSSIBLE ACROSS THE ENTIRE FORECAST AREA...THE
HIGHEST POPS SATURDAY AND SATURDAY NIGHT WILL BE CARRIED ALONG AND
NORTH OF THE FRONT...IMPACTING MAINLY NORTHERN AND EASTERN PORTIONS
OF THE FORECAST AREA.
SUNDAY THROUGH WEDNESDAY...THE UPPER LEVEL LOW WILL BEGIN TO FILL ON
SUNDAY AS IT LIFTS EAST INTO THE SRN PLAINS. PCPN CHANCES WILL
LINGER SUNDAY INTO MONDAY...BEFORE THE SYSTEM EXITS THE SOUTHERN
PLAINS INTO THE ARKLATEX. DRIER AND WARMER CONDITIONS ARE EXPECTED
TUESDAY INTO WEDNESDAY AS A POSITIVELY TILTED RIDGE EXTENDS FROM THE
DESERT SOUTHWEST INTO NRN MINNESOTA. HIGHS WILL RETURN TO THE LOWER
80S FROM THE MIDDLE 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1253 PM CDT WED MAY 21 2014
AVIATION FORECAST CONCERNS DEAL WITH CONFIDENCE ON CONVECTIVE
DEVELOPMENT LATE THIS AFTERNOON INTO THE EVENING. VSBL SAT PICS
AND OBS SHOW FRONT HAS PUSHED UP AGAINST THE FRONT RANGE AND
UPSLOPE FLOW HAS RESULTED ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA. AC CLOUD COVER ACROSS THE MODDLE OF THE STATE A RESULT
OF PREVIOUS WEAK CONVECTION...MUCH THE SAME AS TUESDAY. THIS
CONVECTIVE DEBRIS WILL CONTINUE TO DRIFT NORTH DURING THE
AFTERNOON. CURRENT THOUGHT IS FOR CONVECTION TO DEVELOP CLOSE TO
THE DENVER FRONT RANGE AREA AS WELL AS NEAR THE LARAMIE RANGE IN
SOUTHEAST WY. SHORT RANGE AND CONVECTION ALLOWING MODELS SUGGEST
THAT FRONT RANGE CONVECTION WILL BE MOST ROBUST THROUGH THE
AFTERNOON AND AN ORGANIZED CLUSTER OF TSRA SHOULD MOVE NORTHEAST
INTO SOUTHWEST NEB AFTER 00Z. RAP13 SHOWING DECENT ELEVATED
INSTABILITY THROUGH MIDNIGHT TO MAINTAIN CONVECTION SOUTH OF I80
CORRIDOR...BUT CONFIDENCE IS LOW TO MAINTAIN STORMS THE FURTHER
NORTH IT GETS. HAVE INCLUDED A PREVAILING GROUP FOR -TSRA IN THE
LBF TAF...BUT ONLY PROB30 GROUP IN FOR KVTN.
SHOULD BE CONVECTIVE DEBRIS AGAIN TMRW MORNING...SIMILAR TO THE
LAST TWO DAYS. STRATUS SHOULD BE CONFINED TO WEST OF KVTN-KLBF
LINE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...JWS
LONG TERM...CLB
AVIATION...JWS
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
330 PM PDT WED MAY 21 2014
.SYNOPSIS...A LOW PRESSURE SYSTEM WILL CIRCULATE OVER SOUTHERN
NEVADA AND SURROUNDING AREAS THROUGH FRIDAY PRODUCING ISOLATED TO
SCATTERED SHOWERS AND A FEW THUNDERSTORMS. THE SYSTEM WILL FINALLY
MOVE AWAY TO THE EAST SATURDAY...WITH RAIN CHANCES DIMINISHING AND
TEMPERATURES QUICKLY CLIMBING OVER THE HOLIDAY WEEKEND.
&&
.SHORT TERM...THROUGH FRIDAY NIGHT...THE CIRCULATION CENTER OF THE
CUTOFF LOW HAS REMAINED OVER CENTRAL NYE COUNTY THROUGH THE DAY BUT
IT WILL QUICKLY DIVE DOWN OVER SOUTHERN CALIFORNIA TONIGHT. THIS IS
DUE TO ENERGY ROTATING DOWN THE WEST SIDE OF THE LOW WHICH WAS
AIDING IN PRODUCING A BAND OF CONSOLIDATED SHOWERS OVER THE
SOUTHWEST PART OF INYO COUNTY. THE 18Z NAM AND HRRR INDICATE THESE
SHOWERS WILL PUSH DOWN THROUGH NORTHWEST SAN BERNARDINO COUNTY THIS
EVENING AND A THUNDERSTORM OR TWO WILL ALSO BE POSSIBLE. SHOWERS
WILL DIMINISH AFTER 06Z AS THE LOW CENTER MOVES TOWARD THE SOUTHERN
CALIFORNIA COAST. MODELS ARE IN GOOD AGREEMENT THAT THE SYSTEM WILL
STRADDLE THE MEXICO BORDER AS IT SLOWLY CHURNS TOWARD THE EAST
THROUGH FRIDAY NIGHT. THIS SCENARIO WILL KEEP THE LIMITED MOISTURE
WITH THE SYSTEM MAINLY WEST OF LAS VEGAS THURSDAY. AS THE LOW CENTER
MOVES INTO SOUTHWEST ARIZONA FRIDAY AND FRIDAY NIGHT...WRAP AROUND
MOISTURE WILL BE PULLED DOWN THROUGH SOUTHERN NEVADA AND NORTHWEST
ARIZONA. SHOWERS SHOULD BE CONFINED PRIMARILY TO THE MOUNTAINS.
.LONG TERM...SATURDAY THROUGH TUESDAY.
MEMORIAL DAY WEEKEND IS LOOKING PRETTY TOASTY WITH MODEL CONSENSUS
SHOWING HIGH PRESSURE MOVING OVER THE AREA DURING THE WEEKEND.
YESTERDAY, MODELS WERE FORECASTING A TROUGH MOVING INTO THE WEST
EARLY NEXT WEEK BRINGING SLIGHTLY COOLER TEMPERATURES FOR MEMORIAL
DAY. NOW THE TROUGH AND ANY ASSOCIATED SHORTWAVE ENERGY IS FORECAST
TO STAY WELL NORTH OF THE AREA AND HAVE LITTLE TO NO IMPACT ON
TEMPERATURES. THUS, HIGHS SHOULD TOP OUT A FEW DEGREES ABOVE NORMAL
SATURDAY THEN WARM ANOTHER 3-5 DEGREES SUNDAY AND HOLD STEADY MONDAY
AND POSSIBLY INTO TUESDAY. IT`S A DISTINCT POSSIBILITY THAT
TEMPERATURES COULD AGAIN REACH OR EVEN EXCEED 100 DEGREES IN LAS
VEGAS ON SUNDAY AND MEMORIAL DAY, BUT FOR NOW, DECIDED TO KEEP THEM
IN THE UPPER 90S TO SEE IF MODEL SOLUTIONS MAINTAIN CONTINUITY OR
REVERT BACK TO A STRONGER PACIFIC TROUGH MOVING INTO THE WEST. &&
.AVIATION...FOR MCCARRAN...SOUTHEAST TO EAST WINDS MAY EXCEED 10
KNOTS THROUGH EARLY EVENING BEFORE BECOMING LIGHT AND VARIABLE 1-2
HOURS AFTER SUNSET AND EARLY THURSDAY. AN EASTERLY WIND COMPONENT
CAN BE EXPECTED THURSDAY AFTERNOON. SCT CLOUDS WITH BASES 10-12 KFT
WILL REMAIN AROUND THE AREA WITH SHOWERS POSSIBLE OVER THE SPRING
MOUNTAINS AND SHEEP RANGE THROUGH EARLY THIS EVENING THEN AGAIN
THURSDAY AS A LOW PRESSURE SYSTEM CIRCULATES AROUND SOUTHERN
CALIFORNIA AND SOUTHERN NEVADA.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...A LOW PRESSURE
SYSTEM WILL MOVE FROM CENTRAL NEVADA TO SOUTHERN CALIFORNIA TONIGHT
AND THURSDAY. ISOLATED TO SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS CAN BE EXPECTED OVER AREAS TO THE NORTH AND WEST OF
LAS VEGAS THROUGH THURSDAY. CLOUD BASES WILL GENERALLY BE AROUND
8-10 KFT MSL AND WILL LEAD TO PARTIAL MOUNTAIN OBSCURATION OVER THE
SOUTHERN SIERRA.
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
AZ...NONE.
CA...NONE.
&&
$$
SHORT TERM/AVIATION...ADAIR
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 LAS VEGAS NV
955 AM PDT WED MAY 21 2014
.SYNOPSIS...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL OCCUR
IN THE SOUTHERN GREAT BASIN AND WESTERN MOJAVE DESERT AND LAST
THROUGH FRIDAY. THE SYSTEM WILL FINALLY MOVE AWAY SATURDAY...WITH
RAIN CHANCES DIMINISHING AND TEMPERATURES WARMING OVER THE HOLIDAY
WEEKEND.
&&
.UPDATE...THE CUTOFF UPPER LOW COULD BE SEEN ON SATELLITE LOOPS WITH
A FAIRLY TIGHT CIRCULATION OVER CENTRAL NYE COUNTY THIS MORNING. IT
APPEARS A VORT LOBE IN THE NORTHWEST QUADRANT OF THE SYSTEM WILL
DIVE SOUTHWARD TODAY...ENHANCING SHOWERS AND ISOLATED THUNDERSTORMS
OVER ESMERALDA...INYO AND CENTRAL NYE COUNTIES. THE RUC AND LOCAL
HIGH RES MODELS ARE SHOWING INCREASING POTENTIAL FOR CONVECTION OVER
NORTHWEST SAN BERNARDINO COUNTY LATE THIS AFTERNOON AND EVENING
WHILE THE 12Z GFS KEEPS PRECIP POTENTIAL OVER THE SAN BERNARDINO
MOUNTAINS AND TOWARD THE COAST. NO IMMEDIATE CHANGES ARE NEEDED TO
THE GOING FORECAST AS ISOLATED SHOWERS ARE CURRENTLY INDICATED OVER
NORTHWEST SAN BERNARDINO COUNTY. THE REST OF THE FORECAST AREA
LOOKS FINE BASED ON THE LATEST SATELLITE LOOPS AND MODEL INDICATIONS.
&&
.PREV DISCUSSION...328 AM PDT...
.SHORT TERM...THROUGH FRIDAY NIGHT...AN UPPER LOW CUTOFF FROM THE
MAIN BRANCH OF THE WESTERLIES WILL REMAIN OVER THE REGION THROUGH
FRIDAY BEFORE SLOWLY SHIFTING INTO ARIZONA ON SATURDAY. THIS WILL
LEAD TO A PATTERN OF MAINLY AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS OCCURRING MOSTLY OVER THE HIGHER TERRAIN. ANY
REMAINING SOUTHWEST WINDS WILL BE ACROSS FAR EASTERN MOHAVE COUNTY
TODAY...OTHERWISE NOW THAT UPPER LOW IS OVERHEAD WINDS WILL BE MUCH
LIGHTER. WITH THAT BEING SAID OUTFLOW GUSTS FROM THUNDERSTORMS ARE
POSSIBLE. COOL ONCE AGAIN TODAY WITH TEMPERATURES BACK TO NEAR
NORMAL FRIDAY.
.LONG TERM...SATURDAY THROUGH TUESDAY.
MEMORIAL DAY WEEKEND IS LOOKING LIKE A PRETTY TOASTY WITH MODEL
CONSENSUS SHOWING HIGH PRESSURE MOVING OVER THE AREA DURING THE
WEEKEND. YESTERDAY, MODELS WERE FORECASTING A TROUGH MOVING INTO THE
WEST EARLY NEXT WEEK BRINGING SLIGHTLY COOLER TEMPERATURES FOR
MEMORIAL DAY. NOW THE TROUGH AND ANY ASSOCIATED SHORTWAVE ENERGY IS
FORECAST TO STAY WELL NORTH OF THE AREA AND HAVE LITTLE TO NO IMPACT
ON TEMPERATURES. THUS, HIGHS SHOULD TOP OUT A FEW DEGREES ABOVE
NORMAL SATURDAY THEN WARM ANOTHER 3-5 DEGREES SUNDAY AND HOLD STEADY
MONDAY AND POSSIBLY INTO TUESDAY. IT`S A DISTINCT POSSIBILITY THAT
TEMPERATURES COULD AGAIN REACH OR EVEN EXCEED 100 DEGREES IN LAS
VEGAS ON SUNDAY AND MEMORIAL DAY, BUT FOR NOW, DECIDED TO KEEP THEM
IN THE UPPER 90S TO SEE IF MODEL SOLUTIONS MAINTAIN CONTINUITY OR
REVERT BACK TO A STRONGER PACIFIC TROUGH MOVING INTO THE WEST.
&&
.AVIATION...FOR MCCARRAN...THE GRADIENT WIND WILL CONTINUE TO
SUBSIDE TODAY NOW THAT UPPER LOW HAS MOVED OVERHEAD. IN
FACT...LOOKING AT AN EAST OR SOUTHEAST WIND OF 5-9 KTS DEVELOPING
LATE THIS MORNING AND CONTINUING INTO THIS EVENING. A CHANGE IN
CONFIGURATION MAY BE NECESSARY. SCT-BKN CLOUDS AROUND 10-12 KFT
TODAY AND WEDNESDAY. HIGHER PEAKS WEST OF THE VALLEY WILL BE
PARTIALLY OBSCURED AT TIMES.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...AN UPPER LOW OVER THE AREA WILL LEAD TO A PATTERN OF
MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS TODAY AND
WEDNESDAY. CEILING GENERALLY BETWEEN 5-7 KFT WITH HIGHER PEAKS
PARTIALLY OBSCURED AT TIMES. WIND SPEEDS GENERALLY BETWEEN 5-15 MPH
EXCEPT HIGHER GUSTS NEAR THUNDERSTORMS.
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
AZ...NONE.
CA...NONE.
&&
$$
UPDATE...ADAIR
PREV DISCUSSION...PIERCE/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 RALEIGH NC
251 PM EDT WED MAY 21 2014
.SYNOPSIS...SURFACE HIGH PRESSURE MOVES SOUTH AHEAD OF A COLD FRONT
THAT SLOWLY MOVES SOUTH THROUGH THE REGION THURSDAY INTO FRIDAY.
ANOTHER SURFACE HIGH BUILDS SOUTHEAST OVER THE REGION FOR THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 250 PM WEDNESDAY...
THE LATEST SURFACE ANALYSIS SHOWED A SOUTHWEST-TO-WEST GRADIENT OVER
CENTRAL NORTH CAROLINA OUTSIDE OF A PAIR OF WEAK SURFACE TROUGHS
OVER WESTERN PARTS OF THE STATE...WITH A COLD FRONT WELL TO OUR
NORTH OVER THE GREAT LAKES. REGIONAL RADAR IMAGES SHOWED SCATTERED
DEEP CONVECTION DEVELOPING OVER THE OHIO VALLEY EAST ACROSS THE
BORDER OF PENNSYLVANIA AND MARYLAND...WHERE MIXED-LAYER CAPE WAS
HIGHER ON THE LATEST SPC MESOANALYSIS AND IN AN AXIS OF PRECIPITABLE
WATER VALUES APPROACHING 1.5 INCHES. BASED ON THE 1000-500MB
THICKNESS PROFILE AND 700MB HEIGHTS...ANY DEEP CONVECTION WOULD TEND
TO MOVE SOUTHEAST. THE LATEST SPC MESOANALYSIS INSTABILITY DATA
SUGGESTS MIXED-LAYER CIN STILL PRESENT OVER CENTRAL NORTH
CAROLINA... BUT THE GFS AND NAM BUFR SOUNDINGS...MORE SO THAN THE
LATEST RAP SOUNDINGS...SHOW THE MID-LEVEL CAP ERODING TOWARD 00Z
THROUGHOUT THE AREA...BUT PARTICULARLY TOWARD THE TRIAD.
IN GOOD GENERAL INSTABILITY...WITH LIFTED INDICES TO -5C ON THE
LATEST MSAS...ALONG WITH WEAK SURFACE CONVERGENCE COURTESY OF THE
SURFACE TROUGHS AND THE APPROACH OF A MID-LEVEL SHORTWAVE...AN
ISOLATED SHOWER OR THUNDERSTORM COULD DEVELOP LATE THIS AFTERNOON
INTO EARLY EVENING AS THE CAP ERODES...MAINLY ALONG AND NORTH OF
U.S. 64. LATER THIS EVENING AND INTO THE OVERNIGHT...SOME OF THE
CONVECTIVE-ALLOWING MODELS WOULD SUGGEST THE POTENTIAL FOR SHOWERS
FROM UPSTREAM CONVECTION MOVING SOUTH INTO CENTRAL NORTH CAROLINA...
WITH THE GREATER CHANCES OF THESE TOWARD THE NORTHWEST PIEDMONT AND
AREAS NORTH AND NORTHEAST OF THE TRIANGLE. ANY SHOWER EARLY THIS
EVENING...WITH GOOD LAPSE RATES...COULD PRODUCE A GUSTY WIND...
THOUGH IT WOULD SEEM WITH THE DIURNAL TIMING OF ANY CONVECTION LATER
TONIGHT AND BUFR SOUNDINGS SHOWING A RETURN OF A LITTLE WARMING
ALOFT THAT THE POTENTIAL FOR STRONG CONVECTION OVERNIGHT WOULD BE
LIMITED. ANTICIPATE SOME MID- AND HIGH-LEVEL CLOUDS AT TIMES
OVERNIGHT DUE TO REMNANTS OF UPSTREAM ACTIVITY...AND OVERNIGHT LOWS
SHOULD BE MOSTLY IN THE MID 60S.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 250 PM WEDNESDAY...
THE GFS FORECASTS AN INCREASE IN 850MB THETA-E AIR BY THURSDAY
AFTERNOON...WITH BOTH THE GFS AND THE NAM SUPPORTIVE OF A MODEST MID-
LEVEL SHORTWAVE MOVING NORTHWEST-TO-SOUTHEAST ACROSS CENTRAL NORTH
CAROLINA DURING THE AFTERNOON. THE SURFACE FRONT SHOULD BE STILL TO
OUR NORTHWEST THROUGH THE DAY THURSDAY...EVENTUALLY MOVING THROUGH
MUCH OF CENTRAL NORTH CAROLINA...IF NOT ALL OF THE AREA...THURSDAY
NIGHT. MIXED-LAYER CAPE IN THE LOWEST KM IS AGAIN 1000 TO
1500J/KG... AND DOWNDRAFT CAPE THURSDAY IS FORECAST TO APPROACH
1000J/KG ON THE GFS WITH LIFTED INDICES AT LEAST TO -5C. ONE
LIMITING FACTOR COULD BE THE LOW-LEVEL CONVERGENCE...WHICH MAY BE
REDUCED DUE TO ANTICIPATED VEERING OF THE LOW-LEVEL WINDS AHEAD OF
THE FRONT TO WEST-TO-NORTHWEST ON BOTH THE NAM AND THE GFS. CHANCES
OF PRECIPITATION ON BOTH GUIDANCE ARE LOW...AND CONVECTIVE ALLOWING
MODELS ARE LIMITED IN COVERAGE AS WELL IN GENERAL. STILL...WITH THE
APPROACH AND PASSAGE OF THE MID-LEVEL WAVE...AT LEAST MODEST
INSTABILITY...AND AN INCREASE IN OVERALL MOISTURE...WOULD ANTICIPATE
ISOLATED-TO-SCATTERED SHOWERS AND THUNDERSTORMS BY THURSDAY
AFTERNOON...WITH THIS FORECAST NOTING THE HIGHER CHANCES RELATIVE TO
THE REST OF THE AREA MAINLY ALONG AND SOUTH OF U.S. 64...WHERE THERE
SHOULD BE BETTER WARMING AND OVERALL INSTABILITY. ANY STRONG STORM
COULD PRODUCE A SEVERE WIND GUST BUT CURRENTLY SUCH AN OCCURRENCE
SEEMS ISOLATED. 1000-850MB THICKNESSES SUGGEST THE MAV MOS GUIDANCE
IS ON THE WARM SIDE AND HAVE FORECAST HIGHS THURSDAY WITH A BLEND OF
THE MAV AND THE MET FOR HIGHS FROM 89 TO 93. OVERNIGHT LOWS THURSDAY
NIGHT IN THE LOWER TO MID 60S AS ANY CHANCES FOR PRECIPITATION
DIMINISH...THOUGH THE GFS DOES FORECAST AN INCREASE IN MID-LEVEL
CLOUDS LATE TOWARD THE NORTHWEST PIEDMONT. -DJF
FOR FRI/FRI NIGHT: MODELS AGREE THAT THE FRONT WILL LIKELY BE JUST
SOUTH OF THE STATE FRI MORNING... WITH COOLER DEWPOINTS (IN THE 50S)
ADVECTING IN... BLUSTERY NW WINDS WITHIN A DEEP BOUNDARY LAYER
MAINLY IN THE AFTERNOON... AND ONLY AN ISOLATED SHOT AT A SHOWER OR
STORM IN THE SRN CWA WHERE THE SREF INDICATES A LINGERING AREA OF A
FEW HUNDRED J/KG OF MLCAPE... AND WHERE THE GFS SHOWS A WEAK SHEAR
AXIS SHIFTING ESE... ALONG WITH A WEAK SURFACE LOW. EVEN HERE
THOUGH... THE BOUNDARY LAYER WILL BE FAIRLY DRY... INHIBITING MUCH
COVERAGE... ALTHOUGH DCAPE VALUES WILL REMAIN HIGH ENOUGH TO BRING
ABOUT CONCERN FOR LOCALLY HIGHER WIND GUSTS NEAR ANY SHOWERS/STORMS.
IT IS WORTH NOTING THAT THE ECMWF IS BY FAR THE WETTEST OF THE
MODELS... SHOWING WIDESPREAD CONVECTION OVER THE ENTIRE CWA ALONG A
DIFFUSE AND FURTHER-NORTH SURFACE FRONT. THIS HAS BEEN DISCOUNTED
FOR NOW BUT WILL NEED TO MONITOR LATER RUNS. OTHERWISE... A DRY AND
STABLE COLUMN WILL ENSURE A DRY FORECAST OVER THE REMAINDER OF THE
CWA... DESPITE STRONG SHORTWAVE ENERGY ROTATING ABOUT THE MID LEVEL
VORTEX JUST TO OUR NNE. EXPECT SOME FLAT CUMULUS MAINLY IN THE
AFTERNOON IN THE NORTH AND EAST... WITH MID CLOUDS ACROSS THE FAR
SOUTH... AND THE FEWEST CLOUDS IN THE WRN CWA. HIGHS 80-87... CLOSER
TO THE COOLER NAM-BASED GUIDANCE. EXPECT GENERALLY CLEAR SKIES
FRIDAY NIGHT WITH A COOL CANADIAN-SOURCE (BUT MODIFYING) SURFACE
HIGH BUILDING IN FROM THE NNW. EXPECT BELOW NORMAL LOWS OF 50-57.
FOR SAT/SAT NIGHT: SURFACE HIGH PRESSURE COVERS THE OHIO VALLEY AND
MID-ATLANTIC REGION TO START THE WEEKEND... WITH DRY NW FLOW ALOFT
AND STABLE/SINKING MID LEVELS... ON THE SUBSIDENT SIDE OF THE UPPER
JET. WHILE THIS RESIDENT AIR MASS WILL CONTINUE TO SLOWLY MODIFY...
THICKNESSES WILL START THE DAY NEARLY 30 M BELOW NORMAL... SO HIGHS
ON THE COOL SIDE LOOK REASONABLE... 77-81. CONTINUED BELOW NORMAL
LOWS OF 52-57 WITH THE HIGH CENTER DRIFTING OVERHEAD. -GIH
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 250 PM WEDNESDAY...
EXPECTED CONTINUED DRY WEATHER SUNDAY FOR CENTRAL NC AS THE 850 MB
ANTICYCLONE HOLDS OVER THE SOUTHEAST STATES... WHILE THE SURFACE
HIGH DRIFTS SLOWLY OFF THE COAST... AND RIDGING HOLDS IN THE MID
LEVELS FROM THE OH VALLEY OVER THE MIDSOUTH/GULF STATES. THE
GFS/ECMWF BOTH FORM WEAK LEE TROUGHING OVER VA AND THE FAR WRN NW
PIEDMONT ON MEMORIAL DAY AS THE SURFACE HIGH MOVES FURTHER
OFFSHORE... AND BOTH DEVELOP CONVECTION OVER THE HIGHER TERRAIN MON
AFTERNOON. THIS DOES INDEED LOOK LIKE A GOOD SETUP FOR MOUNTAIN
CONVECTION... BUT THERE ISN`T A LOT OF OPPORTUNITY FOR MOISTURE
RETURN THIS QUICKLY ESPECIALLY WITH NWRLY 850 MB FLOW... AND IT`S
QUESTIONABLE IF ANY OF THIS ACTIVITY WILL BE ABLE TO REACH OUR WRN
CWA GIVEN THE VERY WEAK STEERING FLOW WITH THE MID LEVEL RIDGE AXIS
LOCATED JUST WEST OF THE MOUNTAINS. WILL RETAIN A MENTION OF
ISOLATED STORMS OVER THE FAR WRN CWA MON AFTERNOON INTO EARLY
EVENING. THE SYNOPTIC PATTERN REMAINS SIMILAR ON TUE WITH A VERY
WEAK STEERING FLOW... A SURFACE TROUGH EXTENDING THROUGH CENTRAL
NC... AND AN EVER-WARMING (THICKNESSES RISING TO ABOUT 20 M ABOVE
NORMAL) BUT FAIRLY DRY BOUNDARY LAYER. FORECAST SOUNDINGS CONTINUE
TO SHOW VERY LOW VALUES OF SKINNY CAPE... AND WITH NO DYNAMIC
FORCING MECHANISMS EVIDENT... WILL STICK WITH LOW CHANCE POPS...
FOCUSED ON SEA BREEZE ACTIVITY IN THE AFTERNOON. MODELS SHOW THE MID
LEVEL RIDGE BREAKING DOWN TUE NIGHT/WED WITH SOMEWHAT GREATER MID
LEVEL FLOW BECOMING GENTLY CYCLONIC. EXPECT A SLOW AND STEADY
INCREASE IN BOUNDARY LAYER MOISTURE WITH THICKNESSES HOLDING ABOVE
NORMAL... RESULTING IN A BIT BETTER CHANCE OF AFTERNOON CONVECTION
AREAWIDE. EXPECT TEMPS TO RISE EACH DAY... FROM HIGHS IN THE LOW 80S
AND LOWS AROUND 60 SUN TO THE UPPER 80S/AROUND 90 AND UPPER 60S BY
WED.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 220 PM WEDNESDAY...
VFR CONDITIONS ARE EXPECTED OVERALL DURING THE 18Z VALID TAF PERIOD.
SOMEWHAT DIFFICULT TO DETERMINE HIGHER AREAS...IN A RELATIVE SENSE
IN CENTRAL NORTH CAROLINA...FOR POTENTIAL FOR ANY SHOWERS OR STORMS
FROM VERY LATE THIS AFTERNOON THROUGH THE OVERNIGHT HOURS. HIGHEST
INSTABILITY AND THREAT FOR A SHOWER OR STORM...MAINLY FROM UPSTREAM
ACTIVITY MOVING INTO THE AREA...APPEARS TO BE TOWARD THE TRIAD AND
OVER FAR NORTHEAST NORTH CAROLINA MAINLY NORTHEAST OF KRWI.
INTRODUCED A PROB30 FOR A SHOWER OVERNIGHT AT KINT AND KGSO BASED ON
CONVECTIVE MODEL OUTPUT...KEPT SUCH CONDITIONS OUT AT OTHER TAFS
THOUGH THERE IS A LOW PROBABILITY OF A SHOWER AT ANY SITE OVERNIGHT.
SOUTHWEST-TO-WEST SURFACE WINDS SHOULD GRADUALLY VEER AND BE MORE
WEST-TO-NORTHWEST DURING THE DAY THURSDAY.
BEYOND THE 18Z VALID TAF PERIOD...ISOLATED-TO-SCATTERED
THUNDERSTORMS ARE POSSIBLE IN CENTRAL NORTH CAROLINA THURSDAY
AFTERNOON AND EVENING...AND THEN AGAIN MAINLY FRIDAY AFTERNOON
TOWARD KFAY. DRY CONDITIONS ARE EXPECTED THROUGH THE WEEKEND... AND
THEN PREDOMINANTLY DRY INTO MONDAY. OUTSIDE OF ANY SHOWER OR
STORM...VFR CONDITIONS ARE ANTICIPATED.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF/GIH
LONG TERM...GIH
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
220 PM EDT WED MAY 21 2014
.SYNOPSIS...SURFACE HIGH PRESSURE MOVES SOUTH AHEAD OF A COLD FRONT
THAT SLOWLY MOVES SOUTH THROUGH THE REGION THURSDAY INTO FRIDAY.
ANOTHER SURFACE HIGH BUILDS SOUTHEAST OVER THE REGION FOR THE
WEEKEND.
&&
.NEAR TERM /THIS AFTERNOON AND TONIGHT/...
AS OF 1040 AM WEDNESDAY...
CENTRAL NORTH CAROLINA WAS ON THE NORTHERN PART OF HIGH PRESSURE
SURFACE AND ALOFT THIS MORNING...AND THIS WILL CONTINUE THROUGH THE
AFTERNOON. SURFACE HIGH PRESSURE GRADUALLY MOVES FARTHER SOUTH...AND
WHILE THE 12Z UPPER-AIR ANALYSES SHOWED SOME MODEST MOISTURE AT
850MB AND 700MB OVER NORTH CAROLINA...THERE WAS DRIER AIR AT THESE
LEVELS TO THE WEST THAT SHOULD MOVE INTO THE AREA DURING THE LATE
MORNING AND INTO THE AFTERNOON. RAP MODEL GUIDANCE SUGGESTS THIS
THROUGH ITS MOISTURE FORECASTS AND SOUNDING PROFILES...WITH A RETURN
OF SOME MOISTURE LATE IN THE DAY AND INTO THIS EVENING COINCIDENT
WITH WHAT SHOULD BE A WEAKENING MID-LEVEL SHORTWAVE MOVING INTO
CENTRAL NORTH CAROLINA FROM THE NORTHWEST. RAP SOUNDINGS ARE QUITE
STABLE TO DEEP CONVECTION THROUGH THE EVENING...AND LOW-LEVEL
FORCING IS LIMITED EXCEPT FOR THE PIEDMONT TROUGH THAT SHOULD MOVE
SLIGHTLY EAST DURING THE AFTERNOON. RAP QPF IS DRY FOR THE DAY...AND
THE CONVECTIVE ALLOWING MODELS...EXCEPT FOR THE SPC NMM...SHOW A
LIMITED POTENTIAL FOR SHOWERS AND THUNDERSTORMS THIS AFTERNOON. THE
SPC NMM WOULD SUGGEST THE POTENTIAL FOR SCATTERED COVERAGE IN AREAS
ALONG AND NORTH OF ABOUT U.S. 64 AND ESPECIALLY EAST AND NORTHEAST
OF THE TRIANGLE VERY LATE THIS AFTERNOON INTO THIS EVENING. IF THE
RAP MIXING OF SURFACE DEW POINTS VERIFY...THIS TYPE OF COVERAGE
COULD BE DIFFICULT TO OBTAIN. PUSHING BACK THE TIMING...KEPT THE
SLIGHT CHANCE TO CHANCE PRECIPITATION FORECAST FOR THE PERIOD AFTER
21Z THROUGH THE EVENING ALONG AND NORTH OF A LINE FROM THE TRIAD TO
GOLDSBORO...THE LATTER IN DEFERENCE TO THE SPC NMM OUTPUT. EVEN IF
JUST A COUPLE OF SHOWERS OCCUR...STEEP 1000-500MB LAPSE RATES
APPROACHING 8C/KM AND DOWNDRAFT CAPE TO 800J/KG ON THE LATEST SPC
MESOANALYSIS OUTPUT COULD RESULT IN A GUSTY WIND. AFTERNOON HIGHS
MID 80S TO AROUND 90 WITH A FEW WIND GUSTS IN THE 20S MPH DEVELOPING
AS 925MB WINDS INCREASE THIS AFTERNOON TO 20 TO 25KT. UNDER PARTLY
CLOUDY SKIES TONIGHT ON AVERAGE...OVERNIGHT LOWS MOSTLY IN THE MID
60S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...
THURSDAY AND THURSDAY NIGHT: DEEP NWLY FLOW ALOFT WILL PERSIST
ACROSS THE AREA THROUGH THURSDAY. A WEAK SURFACE FRONT OVER THE
SOUTHERN OHIO VALLEY/TN VALLEY WILL MOVE SOUTH AND EAST INTO THE
AREA THURSDAY AFTERNOON/EVENING...PROPELLED BY A STRONG SHORTWAVE
DIVING SE THROUGH THE GREAT LAKES. WEAK SFC CONVERGENT ALONG THE
FRONT COMBINED WITH STRONG DAYTIME HEATING AND RESULTANT MODERATE
DESTABILIZATION WILL HELP TO SUPPORT SCATTERED THUNDERSTORMS
THURSDAY AFTERNOON AND EVENING. THE MAIN LIMITING FACTOR FOR GREATER
CONVECTIVE COVERAGE WILL BE THE LACK OF DEEP MOISTURE OWING TO NWLY
FLOW ALOFT AND WITH WHAT COULD BE A PERIOD OF SUBSIDENCE/DNVA IN THE
WAKE OF SHORTWAVE DISTURBANCES EXITING THURSDAY MORNING THAT COULD
ACT TO SUPPRESS CONVECTION THURSDAY AFTERNOON. AGAIN...ANY STORMS
THAT DEVELOP WILL HAVE THE POTENTIAL TO PRODUCE DAMAGING
THUNDERSTORM WIND GUSTS AS MODELS SHOW CONTINUED STRONG DCAPE OVER
THE PIEDMONT WITH THE DRY MID-LEVEL AIR AND STEEP LOW-LEVEL LAPSE
RATES...AND A BELT OF 30-40KT BULK SHEAR.
CONVECTION SHOULD DIE DOWN AROUND MIDNIGHT AS THE WEAK BOUNDARY
SETTLES TO OUR SOUTH. ARRIVAL COOLER AIR WILL BE DELAYED UNTIL
FRIDAY/FRIDAY NIGHT...SO LOWS THURSDAY NIGHT WILL STILL BE IN THE
60S.
THE FRONTAL ZONE WILL FINALLY SLIP INTO THE AREA FRIDAY AS ANOTHER
SHORTWAVE SWINGS ACROSS THE MID-ATLANTIC STATES AND A JET DIVES
THROUGH THE TN VALLEY. DRIER AIR FILTERING IN FROM THE NORTH SHOULD
SUPPRESS THE 60F DEWPOINTS AND MLCAPE OF AROUND 1000 J/KG TO THE
SOUTHERN PIEDMONT AND SANDHILLS. DEEP LAYER SHEAR WILL BE STILL
STRONG DUE TO THE AFOREMENTIONED JET AND COULD STILL SUPPORT SOME
ENHANCED UPDRAFTS AND A DAMAGING WIND THREAT...MAINLY CLOSER THE
NC/SC BORDER WHERE LOW-LEVEL LAPSE RATES WILL BE STEEPEST. DEEP
NORTHWEST FLOW WILL CONTINUE TO LIMIT MOISTURE OVERALL...BUT MODELS
APPEAR MORE ACTIVE WITH CONVECTION THAN IN PREVIOUS RUNS. WILL
NUDGE SLIGHT CHANCE POPS UP A BIT ACROSS THE SOUTH...WITH HIGHS
RANGING FROM LOWER 80S NORTH TO UPPER 80S SOUTH. ONCE ANY CONVECTION
COMES TO AN END AND DEWPOINTS BEGIN FALLING INTO THE 50S BEHIND THE
FRONT...LOWS WILL DIP INTO THE 50S AS WELL...55-60 NORTH TO SOUTH.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 320 AM WEDNESDAY...
MUCH MORE SEASONABLE AND STABLE AIR WILL RESIDE OVER THE AREA THIS
WEEKEND AS THE COLD FRONT PUSHES SOUTH AND HIGH PRESSURE BUILDS IN
FROM THE GREAT LAKES REGION. THICKNESSES BOTTOM OUT AROUND 1360M
SATURDAY MORNING...WHICH SUGGEST HIGHS WILL BE JUST SLIGHTLY BELOW
NORMA IN THE UPPER 70S AND LOWER 80S SATURDAY AND SUNDAY. LOWS WILL
BE IN THE 50S. MEANWHILE...THE UPPER TOUGH OFF THE EAST COAST WILL
BEGIN TO GIVE WAY TO A RIDGE BUILDING FROM THE SOUTHERN PLAINS
TOWARD THE MIDWEST...SIGNALING A WARMING TREND EARLY NEXT WEEK WITH
HIGHS BACK IN THE 80S. THERE IS A LITTLE MORE UNCERTAINTY IN THE
LONGWAVE PATTERN TOWARD THE MIDDLE OF THE WEEK AS A THE REMNANTS OF
AN UPPER LOW OVER THE SOUTHWESTERN US DRIFTS ACROSS THE CENTRAL US.
HOWEVER...MOISTURE WILL BE INCREASING AS HIGH PRESSURE SHIFTS
OFFSHORE...BRINGING AN INCREASE IN THE POSSIBILITY OF SOME AFTERNOON
SHOWERS AND STORMS...MORE SO ON TUESDAY AND WEDNESDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 220 PM WEDNESDAY...
VFR CONDITIONS ARE EXPECTED OVERALL DURING THE 18Z VALID TAF PERIOD.
SOMEWHAT DIFFICULT TO DETERMINE HIGHER AREAS...IN A RELATIVE SENSE
IN CENTRAL NORTH CAROLINA...FOR POTENTIAL FOR ANY SHOWERS OR STORMS
FROM VERY LATE THIS AFTERNOON THROUGH THE OVERNIGHT HOURS. HIGHEST
INSTABILITY AND THREAT FOR A SHOWER OR STORM...MAINLY FROM UPSTREAM
ACTIVITY MOVING INTO THE AREA...APPEARS TO BE TOWARD THE TRIAD AND
OVER FAR NORTHEAST NORTH CAROLINA MAINLY NORTHEAST OF KRWI.
INTRODUCED A PROB30 FOR A SHOWER OVERNIGHT AT KINT AND KGSO BASED ON
CONVECTIVE MODEL OUTPUT...KEPT SUCH CONDITIONS OUT AT OTHER TAFS
THOUGH THERE IS A LOW PROBABILITY OF A SHOWER AT ANY SITE OVERNIGHT.
SOUTHWEST-TO-WEST SURFACE WINDS SHOULD GRADUALLY VEER AND BE MORE
WEST-TO-NORTHWEST DURING THE DAY THURSDAY.
BEYOND THE 18Z VALID TAF PERIOD...ISOLATED-TO-SCATTERED
THUNDERSTORMS ARE POSSIBLE IN CENTRAL NORTH CAROLINA THURSDAY
AFTERNOON AND EVENING...AND THEN AGAIN MAINLY FRIDAY AFTERNOON
TOWARD KFAY. DRY CONDITIONS ARE EXPECTED THROUGH THE WEEKEND... AND
THEN PREDOMINANTLY DRY INTO MONDAY. OUTSIDE OF ANY SHOWER OR
STORM...VFR CONDITIONS ARE ANTICIPATED.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...CBL/BLS
LONG TERM...BLS
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1258 PM CDT WED MAY 21 2014
.UPDATE...
ISSUED AT 1255 PM CDT WED MAY 21 2014
NO CHANGES NEEDED. CLOUDS BREAKING UP DVL-FAR BUT THICKER IN NW MN
AS EXPECTED. EXPECT SLOW CLEARING AND CURRENT TEMPS APPEAR OK.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
CLOUDS AND TEMPERATURES WILL BE THE MAIN ISSUE FOR THE PERIOD.
WEST TO NORTHWESTERLY FLOW ALOFT WILL CONTINUE AS THE UPPER TROUGH
FROM YESTERDAY PULLS OFF TO THE EAST. THERE HAS BEEN PLENTY OF
CLOUDS BEHIND THE COLD FRONT THAT MOVED THROUGH...WITH THE ENTIRE
CWA SEEING MOSTLY CLOUDY SKIES THIS MORNING. RUC13 925-850MB RH WHICH
HAS A GOOD HANDLE ON CLOUDS DOES NOT REALLY SEE MUCH DECREASE
UNTIL THE MIDDLE OF THE DAY. THINK THAT CLOUDS WILL CONTINUE FOR
AT LEAST PART OF THE MORNING BEFORE HIGH PRESSURE MOVES IN THIS
AFTERNOON. THINK THAT THERE SHOULD BE SOME SUN LATE IN THE DAY AND
TEMPS WILL STILL GET INTO THE 60S.
TONIGHT...WE SHOULD CONTINUE TO SEE DECREASING CLOUDS AND WINDS
WILL BECOME LIGHT AS THE CENTER OF THE HIGH SETTLES OVER THE AREA.
DEW POINTS WILL DROP DOWN TO NEAR 40 DEGREES AND LOWS WILL BE
MAINLY IN THE LOW TO MID 40S ACROSS THE AREA. WILL HAVE TO WATCH
FOR SOME PATCHY FOG FORMATION BUT NOT CONFIDENT ENOUGH TO INCLUDE
IN THE GRIDS AT THIS POINT. THE UPPER RIDGE WILL CONTINUE TO BUILD
INTO THE PLAINS ON THURSDAY. LIGHT SOUTHEAST WINDS AND SOME SUN
WILL HELP TEMPS GET TO NEAR 70 DEGREES.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 321 AM CDT WED MAY 21 2014
THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE UPPER RIDGE CONTINUES TO
BUILD INTO CANADA...AND MODELS SHOW SOME INDICATION OF SOME FAIRLY
WEAK WAVES RIDING ALONG THE BACK SIDE OF THE RIDGE. THERE COULD BE
SOME CONVECTIVE ACTIVITY WITH THESE WAVES...ALTHOUGH MODELS HAVE
MOST OF PRECIP TO OUR WEST AT THIS POINT. GIVEN THE UPPER LEVEL
FLOW SOME CONVECTION CLIPPING OUR NORTHWESTERN COUNTIES WILL BE
POSSIBLE...SO INCLUDED SOME LOW POPS THURSDAY NIGHT AND FRIDAY.
ACTIVITY WILL BE FURTHER EAST FRIDAY NIGHT AS THE RIDGE AXIS
SHIFTS A BIT EASTWARD AND MOISTURE TRANSPORT KICKS IN. INCLUDED
POPS BEYOND THE DEVILS LAKE AREA BUT KEPT THEM PRETTY LOW FOR NOW.
TEMPS THROUGH THE END OF THE WORK WEEK WILL BE WARMING UP TO ABOVE
NORMAL VALUES WITH HIGHS IN THE MID TO UPPER 70S.
FOR SATURDAY INTO SUNDAY...UPPER LEVEL RIDGE AXIS HAS SHIFTED OVER
THE AREA...WITH WARMER TEMPERATURES EXPECTED INTO THE MID TO UPPER
70S. A SERIES OF DISTURBANCES LOOK TO RIDE OVER THE RIDGE AXIS
DECREASING STABILITY AND ALLOWING FOR BETTER CHANCES FOR SHOWERS AND
TSTMS. OTHERWISE...FOR MONDAY AND TUESDAY...LOOK FOR CONTINUED WARM
TEMPS WITH SHOWERS DECREASING AS SFC HIGH PRESSURE SETTLES ACROSS
THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1255 PM CDT WED MAY 21 2014
STRATUS DECK ERODED QUICKLY IN SE ND AND IS LINGERING IN N RRV. AS A
RESULT FAR AND DVL WILL SEE SCT CIGS EARLY THIS AFTN AND TVF AND GFK
LIFTING STRATUS BEFORE SCT MID TO LATE AFTN AND BJI THIS EVENING.
VFR OVERNIGHT WITH A BIT OF A POTENTIAL FOR FOG DEVELOPMENT WITH
LIGHT WINDS...NOT MENTIONED IN THE TAFS DUE TO LOW CONFIDENCE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...JR
LONG TERM...JR/HOPKINS
AVIATION...JK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
158 PM EDT WED MAY 21 2014
.SYNOPSIS...
THUNDERSTORMS WILL MOVE ACROSS THE REGION TODAY AHEAD OF A COLD
FRONT. THE COLD FRONT WILL CROSS THE REGION TONIGHT. HIGH PRESSURE
WILL THEN BRING FAIR WEATHER TO OUR AREA FOR THE REMAINDER OF THE
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FORECAST FOCUS IN THE NEAR TERM IS THE POTENTIAL FOR SEVERE
WEATHER THIS AFTERNOON INTO THIS EVENING. A 17Z ILN SOUNDING WILL
BE LAUNCHED TO INTERROGATE ATMOSPHERIC CHANGES FROM THIS MORNING
AND ALSO TO AID FOR BETTER ATMOSPHERIC ASSESSMENT FOR LATER THIS
AFTN.
IT LOOKS LIKE THAT PERHAPS THE LATEST HRRR MAY BE LATCHING ON AS
TO WHAT TRANSPIRES LATER THIS AFTERNOON AND EVENING. SCATTERED
CONVECTION ACRS NRN INDIANA INTO NRN/CNTRL OHIO IS WHAT REMAINS
OF NOCTURNAL CONVECTION THAT PUSHED INTO THE REGION WELL AHEAD OF
A COLD FRONT. HRRR AND OTHER MESOSCALE MODELS SUGGEST THAT A
PREFRONTAL CONVERGENCE BOUNDARY...LIKELY AIDED BY CURRENT
CONVECTION...SHOULD ALLOW CONVECTION TO EXPAND IN COVERAGE AND
INTENSITY AS IT SHIFTS SOUTHEAST TOWARD AN INCREASING UNSTABLE
AIRMASS TO THE SOUTH AND SOUTHWEST. DECENT BULK SHEAR WILL EXIST
FOR ORGANIZATION OF STORMS IN EITHER LINE SEGMENTS OR PERHAPS
DISCRETE ROTATORS. MOIST AIR IN THE FORM OF MID/UPPER 60S
DEWPOINTS SHOULD ADVECT INTO THE REGION THIS AFTERNOON. THESE
VALUES COUPLED WITH SFC TEMPS APPROACHING THE LOWER 80S SHOULD
YIELD MLCAPES IN THE 1500-2000 J/KG...WHICH IS MODERATE
INSTABILITY. GIVEN POTENTIAL FOR ROTATORS AND DECENT
INSTABILITY...COUPLED WITH FAVORABLE WET BULB ZERO VALUES IN THE
9-10 FT RANGE...LARGE HAIL IS A CONCERN. ALSO...MID LEVEL DRIER
AIR WILL RESULT IN ENTRAINMENT AND WITH DCAPES PUSHING INTO THE
1500 J/KG...DAMAGING DOWNBURSTS WITH THE HAIL AND/OR PCPN LOADING
WILL ALSO BE A CONCERN. CAN NOT RULE AT AN ISOLATED TORNADO...BUT
IF THIS WERE TO OCCUR...IT WOULD LIKELY BE A RESULT OF CELL
MERGERS AND/OR OUTFLOW BOUNDARIES WITH DEVELOPING CELLS. FORECAST
CALLS FOR LIKELY POPS THIS AFTN WITH THE POPS SHIFTING TOWARD THE
OHIO RIVER BY EVENING. HIGHS WILL RANGE FROM THE UPPER 70S NORTH
TO THE LOWER 80S SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
ONGOING CONVECTION THIS EVENING SAGGING SOUTH OF THE OHIO RIVER
WILL CONTINUE A SLOW PROGRESSION SOUTH AHEAD OF THE COLD FRONT.
MODELS ARE INDICATING A DECREASE IN FORWARD PROPAGATION OF THE
FRONTAL SYSTEM SOUTH OF THE OHIO RIVER TONIGHT. THIS COULD POSE
A FLASH FLOOD THREAT IF STORMS BEGIN TO TRAIN ACROSS THE SAME
LOCATIONS LATE THIS EVENING. WILL HOLD OFF ON ANY MENTION OF THIS
IN THE HWO...AS THERE IS A LARGE AMOUNT OF UNCERTAINTY AS TO THIS
SCENARIO TAKING PLACE DUE TO UNCERTAINTIES IN THE EVENTUAL
LOCATION OF THE FRONTAL BOUNDARY AT THIS TIME FRAME.
THE ILN CWA IS EXPECTED TO BE MAINLY RAIN FREE BY DAYBREAK
THURSDAY WITH THE FRONT SHIFTING SOUTH OF OUR AREA. NORTHWESTERLY
FLOW WILL BRING DRIER AIR INTO THE REGION WITH SEASONABLE
TEMPERATURES AND FAIR WEATHER ON THURSDAY.
HIGH PRESSURE WILL SLOWLY BUILD SOUTHEASTWARD INTO OUR AREA FROM
THE MID WEST THROUGH FRIDAY AND FRIDAY NIGHT. SURFACE WINDS WILL
REMAIN NORTHWESTERLY THURSDAY NIGHT THROUGH FRIDAY AND WILL BECOME
LIGHT ON FRIDAY NIGHT AS THE HIGH BECOMES CENTERED ACROSS THE
REGION. EXPECT MOSTLY CLEAR SKIES DURING THE THURSDAY NIGHT
THROUGH FRIDAY NIGHT TIME PERIOD WITH NEAR NORMAL TEMPERATURES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL ALLOW FOR DRY CONDITIONS THROUGH THE WEEKEND.
COOL NORTHERLY FLOW WILL KEEP TEMPERATURES IN THE UPPER 60S TO LOW
70S ON FRIDAY. A RIDGE WILL GRADUALLY WORK INTO THE REGION THROUGH
THE WEEKEND WITH TEMPERATURES WARMING EACH DAY. BY MONDAY HIGH
TEMPERATURES ARE EXPECTED TO BE IN THE 80S ACROSS THE ENTIRE FA.
PRECIPITATION LOOKS TO HOLD OFF UNTIL TUESDAY. THE GFS IS TRYING TO
DEVELOP A FEW THUNDERSTORMS ACROSS NW PORTIONS OF THE FA ON MONDAY
HOWEVER DECIDED TO GO WITH A DRY FORECAST ON MONDAY AT THIS TIME.
ISOLATED TO SCATTERED THUNDERSTORMS WILL BE POSSIBLE DURING THE DAY
ON TUESDAY. ANY THUNDERSTORM ACTIVITY IS EXPECTED TO DISSIPATE
DURING THE EVENING HOURS WITH THE LOSS OF DAYTIME HEATING.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
SHOWERS AND THUNDERSTORMS ARE FORECAST TO DEVELOP THIS AFTERNOON
NEAR THE NORTHERN TAF SITES IN AN AXIS OF LOW LEVEL CONVERGENCE.
ONCE THIS CONVECTION GETS GOING...IT SHOULD DEVELOP INTO A BROKEN
LINEAR STRUCTURE AS IT MOVES SOUTHEAST THROUGH THE TAF SITES AS IT
FEEDS ON A MOIST AND UNSTABLE AIRMASS. THUNDERSTORMS WILL BE
CAPABLE OF CONTAINING DAMAGING WINDS AND LARGE HAIL WITH BRIEF
MVFR TO IFR VISIBILITIES. ONLY GENERIC MVFR CONDITIONS WITH
THUNDERSTORMS HAVE BEEN PLACED IN THE TAFS ATTM...ALLOWING SHORT
TERM RADAR TRENDS DICTATE THE POTENTIAL FOR DETAILS AND AMENDMENTS.
FOR TONIGHT...MAIN CONVECTION SHOULD BE PUSHING SOUTH OF THE OHIO
RIVER. A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST.
IT APPEARS THAT THE FORCING WITH THE FRONT ITSELF WILL BE WEAK AT
BEST AND MOST CONVECTION IS EXPECTED TO WANE ACRS THE REGION THIS
EVENING WITH DECREASING INSTABILITY. SKIES WILL LIKELY GO PARTLY
CLOUDY OVERNIGHT AND WITH RECENT RAINFALL...SOME MVFR TO LOCALLY
IFR MIST MAY DEVELOP. THE FOG POTENTIAL WILL BE PARTICULARLY HIGHER
ACRS THE SRN TAF SITES WHERE FRONTAL PASSAGE WILL NOT OCCUR UNTIL
NEAR OR AFTER SUNRISE.
ON THURSDAY...FRONT PUSHES SOUTH OF THE REGION. CAA BEHIND THE
FRONT ALONG WITH 850 MB MOISTURE WILL EVENTUALLY ALLOW A BROKEN
CUMULUS DECK TO DEVELOP.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN/LATTO
NEAR TERM...HICKMAN
SHORT TERM...LATTO
LONG TERM...NOVAK
AVIATION...HICKMAN
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
240 PM MDT WED MAY 21 2014
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 226 PM MDT WED MAY 21 2014
CURRENT SURFACE MAP PLACES HIGH PRESSURE ACROSS THE EASTERN
DAKOTAS. PERSISTENT LOW CLOUDS ACROSS NORTHEAST WYOMING HAS
LIMITED SURFACE BASED INSTABILITY. THUNDERSTORMS DEVELOPING OVER
EAST CENTRAL WYOMING INTO COLORADO. LATEST RADAR TRENDS AND
CURRENT RUN OF HRRR BRINGS THUNDERSTORMS INTO NORTHEAST
WYOMING/FAR SOUTHWEST SOUTH DAKOTA THIS EVENING. THUNDERSTORMS
SHOULD PERSIST OVERNIGHT ACROSS WESTERN SOUTH DAKOTA WITH WEAK
850-700MB THETA-E ADVECTION AND STEEP MID LEVEL LAPSE RATES.
HIGH MOVES EAST FOR THURSDAY...WITH INSTABILITY AXIS CREEPING
FURTHER NORTHWARD. WITH LACK OF LARGE SCALE FORCING UNDER UPPER
RIDGE AXIS...THUNDERSTORM ACTIVITY MAY BE LIMITED TO THE HIGHER
TERRAIN OF NORTHEAST WYOMING INTO THE BLACK HILLS.
&&
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 226 PM MDT WED MAY 21 2014
SOUTHWEST FLOW ALOFT REMAINS ACROSS THE REGION LATE THIS WEEK INTO
THE WEEKEND...WITH SEVERAL SHORTWAVE DISTURBANCES EJECTING OUT OF A
PERSISTENT TROF/CUT OFF LOW OVER THE WESTERN UNITED STATES. AN
ACTIVE AND UNSETTLED WEATHER PATTERN WILL CONTINUE...WITH DAILY
CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH MUCH OF THE PERIOD.
MEDIUM RANGE MODELS CONTINUE TO SHOW GOOD AGREEMENT ON THE TRACK AND
TIMING OF UPPER LOW AS IT MOVES FROM THE SOUTHWEST CONUS INTO THE
CENTRAL PLAINS LATER IN THE HOLIDAY WEEKEND. CHANCES FOR PCPN SHOULD
DECREASE BY MONDAY AS THE LOW TRACKS SOUTH AND EAST OF THE AREA.
TEMPERATURES WILL GENERALLY BE A BIT ABOVE AVERAGE THROUGH THE
PERIOD...WITH HIGHS MOSTLY IN THE 70S ON THE PLAINS...60S AND LOWER
70S ACROSS THE BLACK HILLS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 226 PM MDT WED MAY 21 2014
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL CONTINUE ACROSS MUCH OF
THE FORECAST AREA THROUGH TONIGHT. MVFR CONDITIONS AND GUSTY WINDS
ARE POSSIBLE IN THE VICINITY OF ANY HEAVIER SHOWERS. OTHERWISE AREAS
OF MVFR CIGS NOW OVER NE WY INTO PORTIONS OF FAR WRN SD WILL LINGER
TONIGHT INTO THURSDAY MORNING.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...47
LONG TERM...13
AVIATION...13
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
252 PM EDT WED MAY 21 2014
.SHORT TERM (TONIGHT THROUGH THURSDAY)... SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO DEVELOP NORTH OF OUR AREA IN THE NEXT FEW
HOURS...SUPPORTED BY UPPER DIVERGENCE AND A 500 MB VORT MAX.
COVERAGE SHOULD BE MAINLY SCATTERED DUE TO LIMITED MOISTURE ACROSS
THE REGION. THIS ACTIVITY WILL BE MOVING SE...AND IS PROGGED BY THE
LOCAL WRF AND RUC TO AFFECT SW VA BETWEEN 02Z AND MIDNIGHT...THEN NE
TN AFTER MIDNIGHT. MUCAPE IN THE 1500-2000 J/KG RANGE AND 0-6 KM
SHEAR AROUND 35-40 KTS WILL MEAN A CHANCE OF SOME STORMS REACHING
SEVERE LEVELS. ACTIVITY SHOULD DIMINISH AFTER 06Z. BEHIND THE
EXITING VORT MAX.
ANOTHER DISTURBANCE IN THE NW FLOW ALOFT WILL MOVE THROUGH TOMORROW
AFTERNOON. THE CAP TOMORROW AFTERNOON IS WEAKER IN SOUTHERN
AREAS...AND LINGERING BOUNDARIES FROM OVERNIGHT CONVECTION MAY AID
DEVELOPMENT IN THE CENTRAL VALLEY. MLCAPE VALUES WILL BE VERY HIGH
CENTRAL AND SOUTH...UP TO 3500 J/KG ACCORDING TO THE NAM...WITH GOOD
0-6 KM SHEAR. AGAIN...WITH LIMITED MOISTURE...COVERAGE MAY NOT BE
MORE THAN SCATTERED AND POPS WILL STAY IN THE CHANCE RANGE...BUT
WHAT STORMS DO FORM COULD BE STRONG TO SEVERE WITH LARGE HAIL THE
MAIN THREAT.
.LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)...WEAKENING FRONTAL
BOUNDARY WILL SLOWLY DROP SOUTH ACROSS THE REGION THURSDAY NIGHT AND
FRIDAY FOR CONTINUED SCATTERED TO ISOLATED CONVECTION. AIR MASS
WILL BE UNSTABLE AND A 850 JET MOVING THROUGH WILL ALLOW FOR THE
CHANCE OF AN OCCASIONAL STRONG TO SEVERE THUNDERSTORM TO BE
POSSIBLE. UPPER RIDGE BUILDS TO OUR WEST DURING THE WEEKEND PUTTING
THE MRX CWA IN A DRY NORTHWEST FLOW ALOFT FOR DRY CONDITIONS
SATURDAY. LOW LEVEL MOISTURE BEGINS TO MOVE BACK INTO SOUTHERN ARES
LATE SUNDAY AND COULD SEE A FEW ISOLATED STORMS DEVELOP LATE IN THE
DAY. THE RIDGE SHIFTS EAST INTO THE AREA ON MONDAY ALLOWING LOW
LEVEL MOISTURE TO PUSH INTO THE REST OF THE AREA. THIS COMBINED
WITH STRONG DAYTIME HEATING WILL PROVIDE INGREDIENTS FOR ISOLATED
DIURNAL CONVECTION THROUGH THE REST OF THE EXTENDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 62 88 66 87 / 10 20 20 30
KNOXVILLE MCGHEE TYSON AIRPORT, TN 63 85 62 83 / 20 50 20 20
OAK RIDGE, TN 63 85 62 82 / 20 50 20 20
TRI CITIES AIRPORT, TN 63 81 56 78 / 50 40 20 20
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS/MJB
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1221 PM CDT WED MAY 21 2014
.AVIATION...
18Z TAF CYCLE
SURFACE LOW OVER THE NORTHERN TEXAS PANHANDLE WITH FRONTAL BOUNDARY
STRETCHING SOUTHWEST TO NORTHEAST FROM THE NORTHWEST TEXAS PANHANDLE
INTO THE EASTERN OKLAHOMA PANHANDLE. DRYLINE LOCATED FROM THE
SURFACE LOW INTO EASTERN NEW MEXICO. THE DRYLINE SHOULD MOVE FURTHER
EAST INTO THE CENTRAL TEXAS PANHANDLE AS THE SURFACE LOW AND FRONTAL
BOUNDARY LIFT NORTH LATER TODAY AND THIS EVENING. EXPECTING
CONVECTION TO DEVELOP BY 21Z TO 23Z TODAY WHICH SHOULD AFFECT MAINLY
THE AMARILLO AND DALHART TAF SITES. DECIDED TO INTRODUCE A TEMPO
GROUP FOR CONVECTION BETWEEN 00Z AND 04Z THURSDAY AT BOTH TAF SITES
AS THIS APPEARS TO BE THE WINDOW FOR THE GREATEST CHANCES FOR
CONVECTION. VFR CONDITIONS WILL PREVAIL EXCEPT FOR MVFR CEILINGS IN
AND NEAR THE CONVECTION. WINDS WILL BE FROM THE SOUTHWEST 10 TO 20
KNOTS AT THE AMARILLO TAF SITE THEN BACKING AROUND TO THE SOUTHEAST
AND SOUTH 5 TO 15 KNOTS AFTER 00Z THURSDAY. WIND GUSTS TO NEAR 30 TO
40 KNOTS IN AND NEAR THUNDERSTORMS AT THE DALHART AND AMARILLO TAF
SITES. THE FRONTAL BOUNDARY WILL ALLOW FOR NORTH WINDS 10 TO 20 KNOTS
WITH HIGHER GUSTS AT THE DALHART AND GUYMON TAF SITES THEN BECOMING
SOUTH AND SOUTHEAST AT THE DALHART TAF SITE AFTER 20Z TODAY ONCE THE
FRONT LIFTS NORTH. NORTH AND NORTHEAST WINDS 10 TO 20 KNOTS AT THE
GUYMON TAF SITE UNTIL AFTER 06Z TO 09Z THURSDAY ONCE THE FRONT LIFTS
BACK NORTH AND WINDS BECOME SOUTH AND SOUTHEAST 5 TO 15 KNOTS.
SCHNEIDER
&&
.PREV DISCUSSION... /ISSUED 636 AM CDT WED MAY 21 2014/
AVIATION...
RETREATING DRYLINE HAS ALLOWED SURFACE DEWPOINTS TO INCREASE FROM 16
TO 51 DEGREES FAHRENHEIT SINCE 11 PM. SOUTHWEST LOW-LEVEL WINDS AS
SAMPLED BY KAMA VAD WINDS ARE MOIST...WITH RUC ANALYSIS DEPICTING 850
MB DEWPOINTS OF 9 TO 10 DEGREES CELSIUS JUST UPSTREAM. DEEPER AND
RICHER MOISTURE LIES ACROSS SOUTHEAST HALF OF TEXAS PANHANDLE...SOUTH
AND SOUTHEAST OF KAMA.
THICKENING MID-LEVEL CLOUDS THIS MORNING WILL STILL ALLOW SURFACE TO
WARM...WITH CONVECTIVE TEMPERATURES BEING REACHED BY 21Z. DRYLINE
SHOULD BE POISED NEAR KAMA AT THAT TIME...WITH MODEST INSTABILITY
AXIS IN CLOSE PROXIMITY. ISOLATED TO SCATTERED THUNDERSTORMS ARE
EXPECTED MAINLY AFTER 21Z NEAR KAMA AND KGUY...NEAR DRYLINE AND COLD
FRONT RESPECTIVELY. KDHT LESS LIKELY TO BE IMPACTED DUE TO DRIER
LOW- LEVEL AIR. OCCASIONAL VORTICITY MAXIMA EXPECTED TO PASS OVER
THE FORECAST AREA THIS EVENING AND TONIGHT...PROVIDING SUPPORT FOR
SHOWERS AND THUNDERSTORMS. WILL NOT INCLUDE THUNDER IN FORECASTS AT
THIS TIME...BUT WILL WAIT UNTIL HIGHER CERTAINTY OF TIMING AND
LOCATION OF DEVELOPMENT CAN BE ATTAINED.
COCKRELL
PREV DISCUSSION... /ISSUED 506 AM CDT WED MAY 21 2014/
DISCUSSION...
PRECIPITATION CHANCES...WHICH START TODAY AND CONTINUE THROUGH THE
MEMORIAL DAY WEEKEND...GRAB THE MAIN FOCUS OF THIS FORECAST.
THE UPPER LOW THAT WILL BRING INCREASING RAIN CHANCES TO THE
PANHANDLES OVER THE NEXT SEVERAL DAYS WAS CENTERED OVER SOUTHERN NV
EARLY THIS MORNING. WATER VAPOR IMAGERY SHOWED INCREASING MID/UPPER-
LEVEL SUBTROPICAL MOISTURE STREAMING NORTHEAST ACROSS THE SOUTHERN
HIGH PLAINS IN BETWEEN THE UPPER LOW AND RIDGING OVER THE LOWER MS
VALLEY. AT THE SURFACE...A COLD FRONT EXTENDED SOUTHWEST ACROSS KS TO
ALONG THE OK PANHANDLE/KS STATE LINE...WITH A DRYLINE EXTENDING
SOUTHWEST ACROSS THE TX PANHANDLE FROM JUST WEST OF PERRYTON TO
BETWEEN AMARILLO AND HEREFORD.
THESE TWO SURFACE BOUNDARIES...THE COLD FRONT AND DRYLINE...WILL BE
INSTRUMENTAL TO THUNDERSTORM CHANCES THIS AFTERNOON AND EVENING. THE
COLD FRONT IS EXPECTED TO PUSH SOUTH INTO THE NORTHERN TX PANHANDLE
THIS MORNING...BEFORE RETREATING NORTHWARD TOWARD THE CO/KS STATE
LINE THIS AFTERNOON. EXPECT THE DRYLINE /FAIRLY DIFFUSE/ TO BE
POSITIONED FROM AROUND SPEARMAN OR PERRYTON SOUTHWEST ROUGHLY ALONG A
BORGER/AMARILLO/HEREFORD LINE MID TO LATE AFTERNOON. WITH MINIMAL
CAPPING AND A WEAK MID-LEVEL SHORTWAVE TROUGH APPROACHING THE
AREA...ISOLATED TO SCATTERED CONVECTION IS EXPECTED TO INITIATE ALONG
THE BOUNDARIES THIS AFTERNOON. SOME OF THE STORMS COULD BE STRONG TO
SEVERE...WITH HAIL UP TO HALF DOLLAR SIZE AND WIND GUSTS TO 60 MPH
THE PRIMARY THREATS. LOW-LEVEL MOISTURE IS STILL SOMEWHAT
LIMITED...SO THE CONVECTION WILL BE FAIRLY HIGH-BASED. 0-1KM MLCAPES
SHOULD REACH AROUND 1500 J/KG TODAY NORTH OF THE FRONT AND EAST OF
THE DRYLINE. DEEP LAYER SHEAR WILL BE WEAKER ALONG THE DRYLINE...BUT
NOT BAD /30-40 KTS/ JUST NORTH OF THE SURFACE FRONT ACROSS THE OK
PANHANDLE...THUS THINK THE FAR NORTHERN PORTION OF THE CWA WILL BE
THE MOST FAVORABLE LOCATION FOR A FEW SEVERE STORMS. KEPT SOME LOW
POPS IN WEST OF THE DRYLINE/SOUTH OF THE FRONT WHERE SOME HIGH-BASED
SHOWERS OR MAYBE A WEAK THUNDERSTORM CAN/T BE RULED OUT DUE TO THE
INCREASING MID-LEVEL MOISTURE...SOME VERY WEAK INSTABILITY...AND THE
AFOREMENTIONED WEAK MID-LEVEL SHORTWAVE. TEMPS WILL BE COOLER TODAY
THAN THE PAST COUPLE OF DAYS...WITH FORECAST HIGHS IN THE LOWER 80S
TO LOWER 90S.
THUNDERSTORM CHANCES WILL BE ON THE INCREASE THURSDAY THROUGH
SATURDAY...AND LINGER THROUGH MONDAY. THE BIG PICTURE HASN/T CHANGED
MUCH...WITH THE UPPER LOW PROGGED TO SLOWLY WOBBLE ACROSS THE
SOUTHWEST THROUGH EARLY SATURDAY MORNING BEFORE LIFTING ACROSS THE
SOUTHERN ROCKIES AND SOUTHERN/CENTRAL HIGH PLAINS OVER THE HOLIDAY
WEEKEND...EVENTUALLY PUSHING EAST OF THE PANHANDLES LATE MONDAY
NIGHT/TUESDAY. LOW-LEVEL GULF MOISTURE WILL ADVECT NORTHWEST THROUGH
THE PANHANDLES INTO EASTERN NM ON THURSDAY...THEN REMAIN IN PLACE
THROUGH THE UPCOMING WEEKEND. THE COMBINATION OF THIS GULF MOISTURE
AND THE SUBTROPICAL MOISTURE TAP ALOFT WILL BOOST PRECIPITABLE WATER
VALUES TO JUST UNDER AN INCH IN THE NORTHWEST PANHANDLES TO NEAR AN
INCH AND A HALF IN THE EASTERN PANHANDLES. DAILY ROUNDS OF
THUNDERSTORMS ARE ANTICIPATED THROUGH MONDAY DUE TO FORCING FROM
EJECTING WEAK SHORTWAVES...BROAD DIFFLUENCE ALOFT...AND DIURNAL
HEATING OF A WEAKLY CAPPED ATMOSPHERE. THE NIGHTLY STRENGTHENING OF
THE LLJ WILL ALSO LIKELY HELP TO SUSTAIN SOME OF THE CONVECTION INTO
THE OVERNIGHT HOURS THURSDAY NIGHT THROUGH SUNDAY NIGHT.
IN TERMS OF SEVERE WEATHER...A FEW STRONG TO SEVERE STORMS WILL BE
POSSIBLE BOTH THURSDAY AND FRIDAY. INSTABILITY WILL BE DECENT WITH
MLCAPES PROGGED AROUND 1500 J/KG EACH DAY...BUT FLOW ALOFT AND
RESULTANT DEEP LAYER SHEAR WILL BE ON THE WEAK SIDE /30 KTS OR LESS/.
THIS WILL BE SUFFICIENT TO SUPPORT SOME STRONG MULTICELLULAR
CONVECTION...BUT WIDESPREAD/ORGANIZED SEVERE WEATHER IS NOT
ANTICIPATED DUE TO THE WEAKER SHEAR. CONDITIONS DO LOOK MORE
FAVORABLE FOR MORE ORGANIZED SEVERE WEATHER SATURDAY AND SUNDAY AS
THE FLOW ALOFT STRENGTHENS AHEAD OF THE APPROACHING UPPER LOW. DEEP
LAYER SHEAR SHOULD INCREASE TO AROUND 40 KTS OR HIGHER ACROSS THE
WESTERN AND CENTRAL PANHANDLES ON SATURDAY...WITH SIMILAR VALUES THAN
TRANSLATING ACROSS THE CENTRAL AND EASTERN PANHANDLES ON SUNDAY. CONTINUED
MOIST LOW-LEVELS AND COOLING TEMPS ALOFT WILL LIKELY LEAD TO MLCAPES
IN THE 1500-2000 J/KG RANGE. ACTUAL VALUES WILL BE MODULATED BY CLOUD
COVER AND POSSIBLE EARLY DAY CONVECTION...LEADING TO SOME UNCERTAINTY
HERE. HOWEVER...IT DOES APPEAR THAT SATURDAY AND SUNDAY WILL BE THE
DAYS TO WATCH FOR MORE ORGANIZED SEVERE CONVECTION. SOME SEVERE
POTENTIAL WILL LINGER ACROSS THE FAR EASTERN PANHANDLES ON
MONDAY...BEFORE THE RAIN AND THUNDERSTORMS SHIFT EAST OUT OF THE AREA
MONDAY NIGHT AS THE UPPER LOW TRACKS EAST INTO KS/OK. HEAVY
RAINFALL...LEADING TO SOME LOCALIZED FLOODING...WILL ALSO BE POSSIBLE
THURSDAY THROUGH MONDAY GIVEN THE AMPLE MOISTURE IN PLACE AND
POSSIBLE TRAINING FROM REPEATED ROUNDS OF CONVECTION.
DRY CONDITIONS WILL RETURN NEXT TUESDAY AND WEDNESDAY AS SUBSIDENCE
TAKES HOLD BEHIND THE DEPARTING UPPER LOW. AFTER A STRETCH OF COOLER
WEATHER THROUGH THE HOLIDAY WEEKEND...TEMPS WILL BEGIN TO REBOUND
TUESDAY AS HEIGHTS RISE AS SHORTWAVE RIDGING BUILDS IN BEHIND THE
UPPER LOW.
KB
FIRE WEATHER...
ELEVATED FIRE WEATHER CONDITIONS WILL BE POSSIBLE ACROSS THE FAR
WESTERN PANHANDLES THIS AFTERNOON INTO EARLY THIS EVENING. SOUTH TO
SOUTHWEST WINDS ARE EXPECTED TO INCREASE TO 15 TO 20 MPH WHILE
RELATIVE HUMIDITIES FALL TO 10 TO 20 PERCENT. ISOLATED THUNDERSTORMS
IN THIS AREA COULD ALSO PRODUCE A FEW CLOUD-TO-GROUND LIGHTNING
STRIKES AND LITTLE RAINFALL. NO ELEVATED OR CRITICAL FIRE WEATHER
CONDITIONS ARE ANTICIPATED THURSDAY THROUGH EARLY NEXT WEEK DUE TO
INCREASING MOISTURE AND RAINFALL CHANCES.
KB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
11/13
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
326 PM MDT WED MAY 21 2014
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY NIGHT)
ISSUED AT 319 PM MDT WED MAY 21 2014
VISIBLE AND RADAR IMAGERY IS SHOWING TSTMS DEVELOPING IN THE
NORTHERN LARAMIE RANGE. THESE STORMS WILL BE MOVING INTO AN
UNSTABLE ENVIRONMENT OVER THE PLAINS WITH DEWPOINTS OF 45-55F AND
SBCAPES IN THE 1500-2000 J/KG RANGE. WHILE FLOW ALOFT IS WEAKER
THAN YESTERDAY...DEEP LAYER SHEAR OF 35-40 KTS WILL STILL BE
SUFFICIENT FOR SUPERCELLS CAPABLE OF PRODUCING LARGE HAIL. ADDED
THE POTENTIAL FOR LARGE HAIL OVER CONVERSE AND NIOBRARA COUNTIES AS
CONVECTIVE PARAMETERS ARE JUST AS FAVORABLE UP THERE AS FURTHER
SOUTH. STORM INITIATION HAS BEEN QUITE LIMITED SO FAR OVER THE
SOUTHERN LARAMIE RANGE...PERHAPS BECAUSE SFC WINDS ARE MORE
SOUTHERLY OVER LARAMIE COUNTY. THINKING THAT THE STRONGEST STORMS
WILL BE ACROSS SOUTHEAST WY THIS AFTN WITH CAPE DROPPING OFF TO
500-1000 OVER THE NEBRASKA PANHANDLE. WHILE LARGE HAIL WILL BE THE
PRIMARY THREAT...CANNOT RULE OUT AN ISOLATED WEAK TORNADO. 0-1KM
HELICITY VALUES ARE CURRENTLY LESS THAN 50 OVER MUCH OF THE PLAINS
WITH LCL HEIGHTS AROUND 1 KM. THE HRRR HAS BEEN CONSISTENT OVER THE
PAST FEW RUNS AT SHOWING THE MOST WIDESPREAD STORM CONVERGE TO THE
NORTH OF LARAMIE COUNTY...WHICH SEEMS ON TRACK SO FAR. STORMS WILL
BEGIN TO WIND DOWN BY LATE EVENING.
UPPER LEVEL LOW CONTINUES TO SPIN OVER THE DESERT SOUTHWEST TOMORROW
WITH SOUTH-TO-SOUTHWESTERLY FLOW ALOFT. THE MAIN CHANGE FOR THURS
WILL BE THAT THE WINDS ALOFT WEAKEN SUBSTANTIALLY...THUS THE DEEP
LAYER SHEAR DECREASES. 0-6KM SHEAR VALUES ARE DOWN TO 15-25 KTS
OVER THE PLAINS DURING THE AFTN. THERE IS STILL GOOD INSTABILITY
WITH SBCAPES AROUND OF 1500-1750...SO TSTMS WITH HEAVY RAIN WILL
PROBABLY THE PRIMARY THREAT WITH THE SLOWER STORM MOTIONS...AS
OPPOSED TO LARGE HAIL.
.LONG TERM...(FRIDAY THROUGH TUESDAY NIGHT)
ISSUED AT 319 PM MDT WED MAY 21 2014
THE UPPER LOW WILL SLOWLY MOVE EASTWARD FROM THE DESERT SOUTHWEST
TOWARD THE SOUTHERN PLAINS FRI-SUN. LOOKING AT A GOOD COVERAGE FOR
SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST AREA THROUGH THIS
TIME. HEAVY RAIN IS POSSIBLE WITH SOME OF THIS ACTIVITY...ESPECIALLY
FOR FRIDAY AND SUNDAY. SHORTWAVE RIDGING WILL MOVE OVERHEAD FOR
MONDAY...WITH WARMING TEMPERATURES AND MUCH DRIER CONDITIONS
ANTICIPATED. FLOW ALOFT WILL BACK TO THE SOUTHWEST ON TUESDAY WITH
SHORTWAVE ENERGY MOVING OVERHEAD IN THE AFTERNOON. WILL SEE A RETURN
OF SOME SHOWERS AND AFTERNOON THUNDERSTORMS MAINLY FOR SOUTHEAST
WYOMING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1211 PM MDT WED MAY 21 2014
WIDELY SCATTERED SHOWERS AND STORMS LOOK LIKELY TODAY BEGINNING
OVER THE MOUNTAINS EARLY THIS AFTERNOON...SHIFTING EAST ACROSS THE
PLAINS THROUGH THE EVENING. A FEW OF THE STORMS LOOK TO BE STRONG TO
SEVERE WITH HAIL AND STRONG DOWNBURST WINDS IN THE LATE
AFTERNOON...ESPECIALLY FROM KCYS TO KTOR AND POINTS EAST. COULD BE
A PERIOD OF IFR CIGS/VSBYS AFTER STORMS CLEAR TO THE EAST AND
MOIST UPSLOPE FLOW OCCURS THROUGH THE EARLY MORNING HOURS FOR THE
EASTERN TERMINALS. LOOKING ALSO AT MVFR CIGS SPILLING INTO THE
LARAMIE VALLEY FROM THE SOUTH OVERNIGHT. ANOTHER ROUND OF SHOWERS
AND STORMS IS EXPECTED FOR THURSDAY.
&&
.FIRE WEATHER...
ISSUED AT 319 PM MDT WED MAY 21 2014
NO FIRE WEATHER CONCERNS THROUGH THE WEEKEND. A MOIST AIRMASS WILL
BE IN PLACE ACROSS THE REGION THROUGH THE WEEKEND. THIS WILL CAUSE
SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP EVERY AFTERNOON.
MINIMUM AFTERNOON HUMIDITY VALUES WILL GENERALLY BE ABOVE 40 PERCENT
AND WINDS WILL BE LIGHT OUTSIDE OF THUNDERSTORMS.
&&
.HYDROLOGY..
ISSUED AT 319 PM MDT WED MAY 21 2014
NORMAL TO ABOVE NORMAL TEMPERATURES TO CONTINUE FOR THE REMAINDER OF
THE WEEK FOR THE FORECAST AREA...ALONG WITH A CONTINUED WET PATTERN.
RISES ON TRIBUTARIES AND HEADWATERS ARE EXPECTED FOR THE SNOWY AND
SIERRA MADRE RANGES WITH THESE WARM TEMPERATURES. THE LARAMIE
RIVER...UPPER NORTH PLATTE AND LITTLE SNAKE RIVERS WILL CONTINUE TO
SEE RISES TO AND IN SOME CASES INTO FLOOD STAGE THROUGH THE END OF
THE WEEK. RAIN CHANCES CONTINUE JUST ABOUT EVERY AFTERNOON AND
EVENING THROUGH THE WEEKEND. MODELS SHOW THE POTENTIAL FOR A PERIOD
OF MODERATE RAIN SATURDAY NIGHT AND SUNDAY FOR AREAS WEST OF THE
LARAMIE RANGE. THIS IS DUE TO A SLOW MOVING LOW PRESSURE SYSTEM
TRACKING ACROSS CENTRAL COLORADO. FREEZING LEVELS LOOK TO STAY ABOVE
10K FEET THROUGH THIS EVENT. SO RAPID SNOW MELT AND SIGNIFICANT
FLOODING/RIVER RISES COULD TAKE PLACE IF IT MATERIALIZES. WILL
CONTINUE TO MONITOR AND ISSUE ANY WATCHES AS THE EVENT DRAWS CLOSER.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...RJM
AVIATION...RJM
FIRE WEATHER...FINCH
HYDROLOGY...FINCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1259 PM MDT WED MAY 21 2014
.UPDATE...
ISSUED AT 1252 PM MDT WED MAY 21 2014
A TORNADO WATCH HAS BEEN ISSUED FOR LARAMIE...PLATTE...AND GOSHEN
COUNTIES THROUGH 8PM. CONVECTION IS BEGINNING TO INITIATE ALONG THE
LARAMIE RANGE AND SOUTHWARD INTO THE LARAMIE COUNTY FOOTHILLS.
WHILE 0-1KM HELICITIES ARE NOT OVERLY IMPRESSIVE...BACKED WINDS TO
THE EAST OF AN OUTFLOW BOUNDARY THAT EXTENDS FROM GREELEY TO
CHEYENNE COULD ENHANCE LLVL HELICITIES/ROTATION.
ISSUED AT 1058 AM MDT WED MAY 21 2014
SEVERE THREAT CONTINUES TO LOOK ON TRACK FOR MUCH OF THE PLAINS
THIS AFTN. THE RUC SHOWS AROUND 1500 J/KG OF CAPE WITH CIN CLOSE
TO ZERO BY 21Z. FLOW ALOFT AND DEEP LAYER SHEAR IS WEAKER THAN
YESTERDAY...HOWEVER 35-40 KTS OF 0-6KM SHEAR DURING THE EARLY AFTN
IS SUFFICIENT FOR SUPERCELLS. THE MODELS DO INDICATE THIS SHEAR
DROPPING TO 25-30 KTS BY THIS EVENING HOWEVER. STILL LOOKING LIKE
HAIL WILL BE THE PREDOMINANT THREAT...ALONG WITH HEAVY RAIN AS
STORM MOTIONS WILL BE SLOWER THAN THE PAST FEW DAYS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 407 AM MDT WED MAY 21 2014
AN ACTIVE AFTERNOON AND EARLY EVENING AHEAD ACROSS SE WY AND THE
SRN HALF OF THE NEBRASKA PANHANDLE TODAY AS DIFFLUENT SSW FLOW
INTERACTS WITH A STALLED SFC BOUNDARY THAT IS LOCATED SOUTH OF THE
CWFA. BEFORE THEN...LINGERING MORNING CONVECTION HAS SHOWN SIGNS
OF WEAKENING OVER THE PAST FEW HOURS AND WILL CONTINUE TO DO SO
THROUGH SUNRISE. BY DAY BREAK...ONLY ANTICIPATE A FEW REMAINING
SHOWERS AND SPRINKLES. THESE TOO SHOULD COMPLETE DISSIPATE BY MID-
MORNING.
ATTENTION THEN TURNS TO SEVERE WEATHER POTENTIAL THIS AFTERNOON
AND EVENING. 09Z SFC ANALYSIS HAS STALLED BOUNDARY ALONG THE FRONT
RANGE FOOTHILLS. DEW POINTS TO THE EAST OF THIS FTR ARE IN THE MID
40S TO LOW 50S AND TO THE WEST IN THE 20S AND 30S. FOG PRODUCT
SHOWING PRONOUNCED AREAS OF LOW CLOUDS AND FOG FROM ALBANY COUNTY
EAST THRU THE SOUTHEAST WYOMING PLAINS. SYNOPTICALLY...THIS IS
OCCURRING AHEAD OF AN UPPER CLOSED LOW DETACHED FROM THE MAIN
WESTERLIES SPINNING OVR THE GREAT BASIN. THE COMBINATION OF THE
PATTERN...BOTH SFC AND ALOFT COMBINED WITH SOUPY DEW POINTS AND AM
FOG/LOW CLOUDS IS A SURE FIRE BET FOR A SEVERE WEATHER SET-UP THIS
AFTERNOON/EARLY EVENING. THE QUESTION IS NOT IF IT WILL
OCCUR...ITS MORE TRYING TO PIN DOWN SPECIFICS OF WHERE AND HOW
STRONG. GLOBAL MODELS ARE SIMILAR IN SHOWING CAP ERODING BY AROUND
2 PM WITH CONVECTIVE INITIATION OVR ALBANY COUNTY AND THE LARAMIE
RANGE AS SHORTWAVE ENERGY STREAMS OVERHEAD AND CONVECTIVE TEMPS
ARE REACHED. STORM MOTION WILL BE SOUTHWESTERLY INITIALLY...BUT
WILL DEVIATE MORE WESTERLY AS THE UPDRAFTS STRENGTHEN. STORM
MOTIONS MAY EVEN TURN TOWARDS THE ESE OVR THE SRN PANHANDLE THIS
EVENING. AFTERNOON 0-6 KM SHEAR VALUES ALONG WITH A VEERING
PROFILE WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS TO BE THE
PRIMARY THUNDERSTORM MODE. SO...AS THESE THUNDERSTORMS EMERGE FROM
THE TERRAIN ONTO THE SOUTHEAST WYOMING HIGH PLAINS...THEY WILL
ENCOUNTER A MUCH BETTER AIR MASS...WITH THE STRONGEST STORMS
DEVIATING RIGHT OF THE MEAN FLOW. STORMS PUSH INTO
PLATTE/GOSHEN/LARAMIE COUNTIES THRU THE LATE AFTERNOON AND INTO
THE CENTRAL/SOUTHERN NEBRASKA PANHANDLE BY THIS EVENING. PROGD
SBCAPES PEAK AT 1200-1500 J/KG OVR THIS SAME AREA. LARGE HAIL WILL
BE THE PRIMARY HAZARD ASSOCIATED WITH THE LARGEST STORMS AS STEEP
LAPSE RATES IN THE HAIL GROWTH REGION COMBINE WITH FREEZING LEVELS
THAT ARE LOWER THAN 10 KFT AGL. ALTHOUGH NOT RULING DAMAGING WINDS
OUT...THE MOIST SUB-CLOUD AIR MASS WILL INHIBIT COVERAGE AND
SEVERITY. LOW LCLS ALONG WITH 0-1KM HELICITY VALUES THAT CLIMB
ABOVE 100 M2/S2 ALSO POINT TO THE POSSIBILITY OF A FEW TORNADOES.
MODELS SUGGEST AREAS FROM SRN PLATTE/GOSHEN INTO ERN LARAMIE AND
KIMBALL COUNTIES OF HAVING THE BEST SHOT. CONVECTION WILL LIKELY
AGAIN LINGER INTO THE OVERNIGHT HOURS...THOUGH COVERAGE/STRENGTH
WILL BE SIGNIFICANTLY LESS.
NOT MUCH PATTERN CHANGE FOR THURSDAY AS THE UPPER-LOW MOVES TO NR
THE CA/AZ STATELINE BY LATE IN THE DAY. WINDS ALOFT WILL BE
NOTICEABLY LIGHTER ON THURSDAY HOWEVER WITH 0-6KM SHEAR VALUES
FALLING TO 15-25 KNOTS THURSDAY AFTERNOON. SBCAPES AGAIN WILL CLIMB
ABOVE 1000 J/KG THURSDAY. HOWEVER...WITH LIGHTER WINDS ALOFT THINK
THAT CONVECTION WILL BE LESS DISCRETE COMPARED TO WEDNESDAYS. SFC
DEWPOINTS WILL REMAIN NEARLY UNCHANGED AS THE STATIONARY BOUNDARY
REMAINS MOSTLY SOUTH AND WEST OF THE CWFA. STILL KEPT RIBBON OF
SEVERE MENTION ACROSS EXTREME SE WYOMING AND THE SRN NEBRASKA
PANHANDLE WHICH WILL BE IN CLOSEST PROXIMITY OF THE BETTER SHEAR
VALUES. SLOWER STORM MOTION WILL YIELD MORE EFFICIENT RAIN PRODUCERS
ON THURSDAY.
UPPER-LOW MOVES LESS THAN 200 MILES IN 24 HOURS FOR FRIDAY. MODELS
ARE CONSISTENT IN LIFTING A STRONGER SHORTWAVE OVR THE AREA. WINDS
ALOFT WILL BE EVEN LESS ON FRIDAY. THE MAIN CONCERN ON FRIDAY WILL
AGAIN BE EFFICIENT RAIN PRODUCERS AND HEAVY RAIN PRODUCERS AS
LAYERED INSTABILITIES BECOME MORE SKINNY. ALTHOUGH SOME SMALL HAIL
MIGHT BE A POSSIBILITY ON FRIDAY...DO NOT ANTICIPATE SEVERE WEATHER
THREAT AT THIS POINT.
TEMPERATURES WILL REMAIN CONSISTENT THRU THE PERIOD WITH HIGHS IN
LOWER ELEVATIONS HOLDING BETWEEN 65 AND 75 DEGREES.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 407 AM MDT WED MAY 21 2014
SLOW MOVING UPPER LOW WILL CONTINUE TO AFFECT THE WEATHER OVER
THE CWA SATURDAY AND SUNDAY AS IT LIFTS NORTHEAST FROM ARIZONA...
FINALLY REACHING THE CENTRAL PLAINS EARLY MONDAY. THIS SYSTEM WILL
KEEP CHANCES FOR SHOWERS AND TSTMS GOING THROUGH THAT TIME THOUGH
THE INTENSITY OF THE STORMS LOOKS TO DIMINISH. A DRIER REGIME
SHOULD ARRIVE FOR EARLY NEXT WEEK AS THE UPPER LOW MOVES EAST AND
SHORT UPPER RIDGING BUILDS OVER THE REGION. SW UPPER FLOW MAY SET
UP TUESDAY WHICH COULD ALLOW FOR CONVECTION TO RETURN AT THAT
TIME. TEMPERATURES REMAINING MILD THROUGH THE WEEKEND THEN WARMING
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1211 PM MDT WED MAY 21 2014
WIDELY SCATTERED SHOWERS AND STORMS LOOK LIKELY TODAY BEGINNING
OVER THE MOUNTAINS EARLY THIS AFTERNOON...SHIFTING EAST ACROSS THE
PLAINS THROUGH THE EVENING. A FEW OF THE STORMS LOOK TO BE STRONG TO
SEVERE WITH HAIL AND STRONG DOWNBURST WINDS IN THE LATE
AFTERNOON...ESPECIALLY FROM KCYS TO KTOR AND POINTS EAST. COULD BE
A PERIOD OF IFR CIGS/VSBYS AFTER STORMS CLEAR TO THE EAST AND
MOIST UPSLOPE FLOW OCCURS THROUGH THE EARLY MORNING HOURS FOR THE
EASTERN TERMINALS. LOOKING ALSO AT MVFR CIGS SPILLING INTO THE
LARAMIE VALLEY FROM THE SOUTH OVERNIGHT. ANOTHER ROUND OF SHOWERS
AND STORMS IS EXPECTED FOR THURSDAY.
&&
.FIRE WEATHER...
ISSUED AT 407 AM MDT WED MAY 21 2014
FIRE CONCERNS TO REMAIN MINIMAL FOR THE REST OF THE WEEK WITH
CONDITIONS AND FUELS EXPECTED TO REMAIN NON-CRITICAL. SCATTERED
AFTERNOON AND EVENING THUNDERSTORMS WILL OCCUR ALONG AND EAST OF
THE LARAMIE RANGE MOST DAYS WITH VERY GOOD CHANCES FOR WETTING
RAINS. A MORE WIDESPREAD RAIN EVENT SATURDAY NIGHT AND SUNDAY WILL
CONTINUE TO SUPPRESS FIRE WEATHER CONCERNS THRU THE MEMORIAL DAY
WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...FINCH
SHORT TERM...HAHN
LONG TERM...RE
AVIATION...RJM
FIRE WEATHER...HAHN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1211 PM MDT WED MAY 21 2014
.UPDATE...
ISSUED AT 1058 AM MDT WED MAY 21 2014
SEVERE THREAT CONTINUES TO LOOK ON TRACK FOR MUCH OF THE PLAINS
THIS AFTN. THE RUC SHOWS AROUND 1500 J/KG OF CAPE WITH CIN CLOSE
TO ZERO BY 21Z. FLOW ALOFT AND DEEP LAYER SHEAR IS WEAKER THAN
YESTERDAY...HOWEVER 35-40 KTS OF 0-6KM SHEAR DURING THE EARLY AFTN
IS SUFFICIENT FOR SUPERCELLS. THE MODELS DO INDICATE THIS SHEAR
DROPPING TO 25-30 KTS BY THIS EVENING HOWEVER. STILL LOOKING LIKE
HAIL WILL BE THE PREDOMINANT THREAT...ALONG WITH HEAVY RAIN AS
STORM MOTIONS WILL BE SLOWER THAN THE PAST FEW DAYS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 407 AM MDT WED MAY 21 2014
AN ACTIVE AFTERNOON AND EARLY EVENING AHEAD ACROSS SE WY AND THE
SRN HALF OF THE NEBRASKA PANHANDLE TODAY AS DIFFLUENT SSW FLOW
INTERACTS WITH A STALLED SFC BOUNDARY THAT IS LOCATED SOUTH OF THE
CWFA. BEFORE THEN...LINGERING MORNING CONVECTION HAS SHOWN SIGNS
OF WEAKENING OVER THE PAST FEW HOURS AND WILL CONTINUE TO DO SO
THROUGH SUNRISE. BY DAY BREAK...ONLY ANTICIPATE A FEW REMAINING
SHOWERS AND SPRINKLES. THESE TOO SHOULD COMPLETE DISSIPATE BY MID-
MORNING.
ATTENTION THEN TURNS TO SEVERE WEATHER POTENTIAL THIS AFTERNOON
AND EVENING. 09Z SFC ANALYSIS HAS STALLED BOUNDARY ALONG THE FRONT
RANGE FOOTHILLS. DEW POINTS TO THE EAST OF THIS FTR ARE IN THE MID
40S TO LOW 50S AND TO THE WEST IN THE 20S AND 30S. FOG PRODUCT
SHOWING PRONOUNCED AREAS OF LOW CLOUDS AND FOG FROM ALBANY COUNTY
EAST THRU THE SOUTHEAST WYOMING PLAINS. SYNOPTICALLY...THIS IS
OCCURRING AHEAD OF AN UPPER CLOSED LOW DETACHED FROM THE MAIN
WESTERLIES SPINNING OVR THE GREAT BASIN. THE COMBINATION OF THE
PATTERN...BOTH SFC AND ALOFT COMBINED WITH SOUPY DEW POINTS AND AM
FOG/LOW CLOUDS IS A SURE FIRE BET FOR A SEVERE WEATHER SET-UP THIS
AFTERNOON/EARLY EVENING. THE QUESTION IS NOT IF IT WILL
OCCUR...ITS MORE TRYING TO PIN DOWN SPECIFICS OF WHERE AND HOW
STRONG. GLOBAL MODELS ARE SIMILAR IN SHOWING CAP ERODING BY AROUND
2 PM WITH CONVECTIVE INITIATION OVR ALBANY COUNTY AND THE LARAMIE
RANGE AS SHORTWAVE ENERGY STREAMS OVERHEAD AND CONVECTIVE TEMPS
ARE REACHED. STORM MOTION WILL BE SOUTHWESTERLY INITIALLY...BUT
WILL DEVIATE MORE WESTERLY AS THE UPDRAFTS STRENGTHEN. STORM
MOTIONS MAY EVEN TURN TOWARDS THE ESE OVR THE SRN PANHANDLE THIS
EVENING. AFTERNOON 0-6 KM SHEAR VALUES ALONG WITH A VEERING
PROFILE WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS TO BE THE
PRIMARY THUNDERSTORM MODE. SO...AS THESE THUNDERSTORMS EMERGE FROM
THE TERRAIN ONTO THE SOUTHEAST WYOMING HIGH PLAINS...THEY WILL
ENCOUNTER A MUCH BETTER AIR MASS...WITH THE STRONGEST STORMS
DEVIATING RIGHT OF THE MEAN FLOW. STORMS PUSH INTO
PLATTE/GOSHEN/LARAMIE COUNTIES THRU THE LATE AFTERNOON AND INTO
THE CENTRAL/SOUTHERN NEBRASKA PANHANDLE BY THIS EVENING. PROGD
SBCAPES PEAK AT 1200-1500 J/KG OVR THIS SAME AREA. LARGE HAIL WILL
BE THE PRIMARY HAZARD ASSOCIATED WITH THE LARGEST STORMS AS STEEP
LAPSE RATES IN THE HAIL GROWTH REGION COMBINE WITH FREEZING LEVELS
THAT ARE LOWER THAN 10 KFT AGL. ALTHOUGH NOT RULING DAMAGING WINDS
OUT...THE MOIST SUB-CLOUD AIR MASS WILL INHIBIT COVERAGE AND
SEVERITY. LOW LCLS ALONG WITH 0-1KM HELICITY VALUES THAT CLIMB
ABOVE 100 M2/S2 ALSO POINT TO THE POSSIBILITY OF A FEW TORNADOES.
MODELS SUGGEST AREAS FROM SRN PLATTE/GOSHEN INTO ERN LARAMIE AND
KIMBALL COUNTIES OF HAVING THE BEST SHOT. CONVECTION WILL LIKELY
AGAIN LINGER INTO THE OVERNIGHT HOURS...THOUGH COVERAGE/STRENGTH
WILL BE SIGNIFICANTLY LESS.
NOT MUCH PATTERN CHANGE FOR THURSDAY AS THE UPPER-LOW MOVES TO NR
THE CA/AZ STATELINE BY LATE IN THE DAY. WINDS ALOFT WILL BE
NOTICEABLY LIGHTER ON THURSDAY HOWEVER WITH 0-6KM SHEAR VALUES
FALLING TO 15-25 KNOTS THURSDAY AFTERNOON. SBCAPES AGAIN WILL CLIMB
ABOVE 1000 J/KG THURSDAY. HOWEVER...WITH LIGHTER WINDS ALOFT THINK
THAT CONVECTION WILL BE LESS DISCRETE COMPARED TO WEDNESDAYS. SFC
DEWPOINTS WILL REMAIN NEARLY UNCHANGED AS THE STATIONARY BOUNDARY
REMAINS MOSTLY SOUTH AND WEST OF THE CWFA. STILL KEPT RIBBON OF
SEVERE MENTION ACROSS EXTREME SE WYOMING AND THE SRN NEBRASKA
PANHANDLE WHICH WILL BE IN CLOSEST PROXIMITY OF THE BETTER SHEAR
VALUES. SLOWER STORM MOTION WILL YIELD MORE EFFICIENT RAIN PRODUCERS
ON THURSDAY.
UPPER-LOW MOVES LESS THAN 200 MILES IN 24 HOURS FOR FRIDAY. MODELS
ARE CONSISTENT IN LIFTING A STRONGER SHORTWAVE OVR THE AREA. WINDS
ALOFT WILL BE EVEN LESS ON FRIDAY. THE MAIN CONCERN ON FRIDAY WILL
AGAIN BE EFFICIENT RAIN PRODUCERS AND HEAVY RAIN PRODUCERS AS
LAYERED INSTABILITIES BECOME MORE SKINNY. ALTHOUGH SOME SMALL HAIL
MIGHT BE A POSSIBILITY ON FRIDAY...DO NOT ANTICIPATE SEVERE WEATHER
THREAT AT THIS POINT.
TEMPERATURES WILL REMAIN CONSISTENT THRU THE PERIOD WITH HIGHS IN
LOWER ELEVATIONS HOLDING BETWEEN 65 AND 75 DEGREES.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 407 AM MDT WED MAY 21 2014
SLOW MOVING UPPER LOW WILL CONTINUE TO AFFECT THE WEATHER OVER
THE CWA SATURDAY AND SUNDAY AS IT LIFTS NORTHEAST FROM ARIZONA...
FINALLY REACHING THE CENTRAL PLAINS EARLY MONDAY. THIS SYSTEM WILL
KEEP CHANCES FOR SHOWERS AND TSTMS GOING THROUGH THAT TIME THOUGH
THE INTENSITY OF THE STORMS LOOKS TO DIMINISH. A DRIER REGIME
SHOULD ARRIVE FOR EARLY NEXT WEEK AS THE UPPER LOW MOVES EAST AND
SHORT UPPER RIDGING BUILDS OVER THE REGION. SW UPPER FLOW MAY SET
UP TUESDAY WHICH COULD ALLOW FOR CONVECTION TO RETURN AT THAT
TIME. TEMPERATURES REMAINING MILD THROUGH THE WEEKEND THEN WARMING
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 1211 PM MDT WED MAY 21 2014
WIDELY SCATTERED SHOWERS AND STORMS LOOK LIKELY TODAY BEGINNING
OVER THE MOUNTAINS EARLY THIS AFTERNOON...SHIFTING EAST ACROSS THE
PLAINS THROUGH THE EVENING. A FEW OF THE STORMS LOOK TO BE STRONG TO
SEVERE WITH HAIL AND STRONG DOWNBURST WINDS IN THE LATE
AFTERNOON...ESPECIALLY FROM KCYS TO KTOR AND POINTS EAST. COULD BE
A PERIOD OF IFR CIGS/VSBYS AFTER STORMS CLEAR TO THE EAST AND
MOIST UPSLOPE FLOW OCCURS THROUGH THE EARLY MORNING HOURS FOR THE
EASTERN TERMINALS. LOOKING ALSO AT MVFR CIGS SPILLING INTO THE
LARAMIE VALLEY FROM THE SOUTH OVERNIGHT. ANOTHER ROUND OF SHOWERS
AND STORMS IS EXPECTED FOR THURSDAY.
&&
.FIRE WEATHER...
ISSUED AT 407 AM MDT WED MAY 21 2014
FIRE CONCERNS TO REMAIN MINIMAL FOR THE REST OF THE WEEK WITH
CONDITIONS AND FUELS EXPECTED TO REMAIN NON-CRITICAL. SCATTERED
AFTERNOON AND EVENING THUNDERSTORMS WILL OCCUR ALONG AND EAST OF
THE LARAMIE RANGE MOST DAYS WITH VERY GOOD CHANCES FOR WETTING
RAINS. A MORE WIDESPREAD RAIN EVENT SATURDAY NIGHT AND SUNDAY WILL
CONTINUE TO SUPPRESS FIRE WEATHER CONCERNS THRU THE MEMORIAL DAY
WEEKEND.
&&
.HYDROLOGY...
ISSUED AT 407 AM MDT WED MAY 21 2014
NORMAL TO ABOVE NORMAL TEMPERATURES TO CONTINUE FOR THE REMAINDER
OF THE WEEK FOR THE FORECAST AREA...ALONG WITH A CONTINUED WET
PATTERN. RISES ON TRIBUTARIES AND HEADWATERS ARE EXPECTED FOR THE
SNOWY AND SIERRA MADRE RANGES WITH THESE WARM TEMPERATURES. THE
LARAMIE RIVER...UPPER NORTH PLATTE AND LITTLE SNAKE RIVERS WILL CONTINUE
TO SEE RISES TO AND IN SOME CASES INTO FLOOD STAGE THROUGH THE
END OF THE WEEK. RAIN CHANCES CONTINUE JUST ABOUT EVERY AFTERNOON
AND EVENING THROUGH THE WEEKEND. MODELS CONTINUE TO SUGGEST A
PERIOD OF MODERATE RAIN SATURDAY NIGHT AND SUNDAY FOR AREAS WEST
OF THE LARAMIE RANGE. THIS IS DUE TO A SLOW MOVING LOW PRESSURE
SYSTEM TRACKING ACROSS CENTRAL COLORADO. FREEZING LEVELS LOOK TO
STAY ABOVE 10K FEET THROUGH THIS EVENT. SO RAPID SNOW MELT AND
SIGNIFICANT FLOODING/RIVER RISES COULD TAKE PLACE IF IT
MATERIALIZES. WILL CONTINUE TO MONITOR AND ISSUE ANY WATCHES AS
THE EVENT DRAWS CLOSER.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...FINCH
SHORT TERM...HAHN
LONG TERM...RE
AVIATION...RJM
FIRE WEATHER...HAHN
HYDROLOGY...HAHN
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1114 AM MDT WED MAY 21 2014
.UPDATE...
ISSUED AT 1058 AM MDT WED MAY 21 2014
SEVERE THREAT CONTINUES TO LOOK ON TRACK FOR MUCH OF THE PLAINS
THIS AFTN. THE RUC SHOWS AROUND 1500 J/KG OF CAPE WITH CIN CLOSE
TO ZERO BY 21Z. FLOW ALOFT AND DEEP LAYER SHEAR IS WEAKER THAN
YESTERDAY...HOWEVER 35-40 KTS OF 0-6KM SHEAR DURING THE EARLY AFTN
IS SUFFICIENT FOR SUPERCELLS. THE MODELS DO INDICATE THIS SHEAR
DROPPING TO 25-30 KTS BY THIS EVENING HOWEVER. STILL LOOKING LIKE
HAIL WILL BE THE PREDOMINANT THREAT...ALONG WITH HEAVY RAIN AS
STORM MOTIONS WILL BE SLOWER THAN THE PAST FEW DAYS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 407 AM MDT WED MAY 21 2014
AN ACTIVE AFTERNOON AND EARLY EVENING AHEAD ACROSS SE WY AND THE
SRN HALF OF THE NEBRASKA PANHANDLE TODAY AS DIFFLUENT SSW FLOW
INTERACTS WITH A STALLED SFC BOUNDARY THAT IS LOCATED SOUTH OF THE
CWFA. BEFORE THEN...LINGERING MORNING CONVECTION HAS SHOWN SIGNS
OF WEAKENING OVER THE PAST FEW HOURS AND WILL CONTINUE TO DO SO
THROUGH SUNRISE. BY DAY BREAK...ONLY ANTICIPATE A FEW REMAINING
SHOWERS AND SPRINKLES. THESE TOO SHOULD COMPLETE DISSIPATE BY MID-
MORNING.
ATTENTION THEN TURNS TO SEVERE WEATHER POTENTIAL THIS AFTERNOON
AND EVENING. 09Z SFC ANALYSIS HAS STALLED BOUNDARY ALONG THE FRONT
RANGE FOOTHILLS. DEW POINTS TO THE EAST OF THIS FTR ARE IN THE MID
40S TO LOW 50S AND TO THE WEST IN THE 20S AND 30S. FOG PRODUCT
SHOWING PRONOUNCED AREAS OF LOW CLOUDS AND FOG FROM ALBANY COUNTY
EAST THRU THE SOUTHEAST WYOMING PLAINS. SYNOPTICALLY...THIS IS
OCCURRING AHEAD OF AN UPPER CLOSED LOW DETACHED FROM THE MAIN
WESTERLIES SPINNING OVR THE GREAT BASIN. THE COMBINATION OF THE
PATTERN...BOTH SFC AND ALOFT COMBINED WITH SOUPY DEW POINTS AND AM
FOG/LOW CLOUDS IS A SURE FIRE BET FOR A SEVERE WEATHER SET-UP THIS
AFTERNOON/EARLY EVENING. THE QUESTION IS NOT IF IT WILL
OCCUR...ITS MORE TRYING TO PIN DOWN SPECIFICS OF WHERE AND HOW
STRONG. GLOBAL MODELS ARE SIMILAR IN SHOWING CAP ERODING BY AROUND
2 PM WITH CONVECTIVE INITIATION OVR ALBANY COUNTY AND THE LARAMIE
RANGE AS SHORTWAVE ENERGY STREAMS OVERHEAD AND CONVECTIVE TEMPS
ARE REACHED. STORM MOTION WILL BE SOUTHWESTERLY INITIALLY...BUT
WILL DEVIATE MORE WESTERLY AS THE UPDRAFTS STRENGTHEN. STORM
MOTIONS MAY EVEN TURN TOWARDS THE ESE OVR THE SRN PANHANDLE THIS
EVENING. AFTERNOON 0-6 KM SHEAR VALUES ALONG WITH A VEERING
PROFILE WILL BE MORE THAN SUFFICIENT FOR SUPERCELLS TO BE THE
PRIMARY THUNDERSTORM MODE. SO...AS THESE THUNDERSTORMS EMERGE FROM
THE TERRAIN ONTO THE SOUTHEAST WYOMING HIGH PLAINS...THEY WILL
ENCOUNTER A MUCH BETTER AIR MASS...WITH THE STRONGEST STORMS
DEVIATING RIGHT OF THE MEAN FLOW. STORMS PUSH INTO
PLATTE/GOSHEN/LARAMIE COUNTIES THRU THE LATE AFTERNOON AND INTO
THE CENTRAL/SOUTHERN NEBRASKA PANHANDLE BY THIS EVENING. PROGD
SBCAPES PEAK AT 1200-1500 J/KG OVR THIS SAME AREA. LARGE HAIL WILL
BE THE PRIMARY HAZARD ASSOCIATED WITH THE LARGEST STORMS AS STEEP
LAPSE RATES IN THE HAIL GROWTH REGION COMBINE WITH FREEZING LEVELS
THAT ARE LOWER THAN 10 KFT AGL. ALTHOUGH NOT RULING DAMAGING WINDS
OUT...THE MOIST SUB-CLOUD AIR MASS WILL INHIBIT COVERAGE AND
SEVERITY. LOW LCLS ALONG WITH 0-1KM HELICITY VALUES THAT CLIMB
ABOVE 100 M2/S2 ALSO POINT TO THE POSSIBILITY OF A FEW TORNADOES.
MODELS SUGGEST AREAS FROM SRN PLATTE/GOSHEN INTO ERN LARAMIE AND
KIMBALL COUNTIES OF HAVING THE BEST SHOT. CONVECTION WILL LIKELY
AGAIN LINGER INTO THE OVERNIGHT HOURS...THOUGH COVERAGE/STRENGTH
WILL BE SIGNIFICANTLY LESS.
NOT MUCH PATTERN CHANGE FOR THURSDAY AS THE UPPER-LOW MOVES TO NR
THE CA/AZ STATELINE BY LATE IN THE DAY. WINDS ALOFT WILL BE
NOTICEABLY LIGHTER ON THURSDAY HOWEVER WITH 0-6KM SHEAR VALUES
FALLING TO 15-25 KNOTS THURSDAY AFTERNOON. SBCAPES AGAIN WILL CLIMB
ABOVE 1000 J/KG THURSDAY. HOWEVER...WITH LIGHTER WINDS ALOFT THINK
THAT CONVECTION WILL BE LESS DISCRETE COMPARED TO WEDNESDAYS. SFC
DEWPOINTS WILL REMAIN NEARLY UNCHANGED AS THE STATIONARY BOUNDARY
REMAINS MOSTLY SOUTH AND WEST OF THE CWFA. STILL KEPT RIBBON OF
SEVERE MENTION ACROSS EXTREME SE WYOMING AND THE SRN NEBRASKA
PANHANDLE WHICH WILL BE IN CLOSEST PROXIMITY OF THE BETTER SHEAR
VALUES. SLOWER STORM MOTION WILL YIELD MORE EFFICIENT RAIN PRODUCERS
ON THURSDAY.
UPPER-LOW MOVES LESS THAN 200 MILES IN 24 HOURS FOR FRIDAY. MODELS
ARE CONSISTENT IN LIFTING A STRONGER SHORTWAVE OVR THE AREA. WINDS
ALOFT WILL BE EVEN LESS ON FRIDAY. THE MAIN CONCERN ON FRIDAY WILL
AGAIN BE EFFICIENT RAIN PRODUCERS AND HEAVY RAIN PRODUCERS AS
LAYERED INSTABILITIES BECOME MORE SKINNY. ALTHOUGH SOME SMALL HAIL
MIGHT BE A POSSIBILITY ON FRIDAY...DO NOT ANTICIPATE SEVERE WEATHER
THREAT AT THIS POINT.
TEMPERATURES WILL REMAIN CONSISTENT THRU THE PERIOD WITH HIGHS IN
LOWER ELEVATIONS HOLDING BETWEEN 65 AND 75 DEGREES.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 407 AM MDT WED MAY 21 2014
SLOW MOVING UPPER LOW WILL CONTINUE TO AFFECT THE WEATHER OVER
THE CWA SATURDAY AND SUNDAY AS IT LIFTS NORTHEAST FROM ARIZONA...
FINALLY REACHING THE CENTRAL PLAINS EARLY MONDAY. THIS SYSTEM WILL
KEEP CHANCES FOR SHOWERS AND TSTMS GOING THROUGH THAT TIME THOUGH
THE INTENSITY OF THE STORMS LOOKS TO DIMINISH. A DRIER REGIME
SHOULD ARRIVE FOR EARLY NEXT WEEK AS THE UPPER LOW MOVES EAST AND
SHORT UPPER RIDGING BUILDS OVER THE REGION. SW UPPER FLOW MAY SET
UP TUESDAY WHICH COULD ALLOW FOR CONVECTION TO RETURN AT THAT
TIME. TEMPERATURES REMAINING MILD THROUGH THE WEEKEND THEN WARMING
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 407 AM MDT WED MAY 21 2014
PATCHY LIFR CIGS WILL AFFECT MAINLY KCYS EARLY THIS MORNING THEN
LIFT TO VFR BY LATE MORNING. WIDELY SCTD SHOWERS AND TSTRMS
EXPECTED TO MOVE OVER PARTS OF SE WY AND THE NEB PANHANDLE THIS
AFTERNOON AND EVENING OTHERWISE VFR EXPECTED OVERALL. LIFR CIGS
MAY RETURN TO KCYS LATE WEDS NIGHT IN SFC UPSLOPE FLOW.
&&
.FIRE WEATHER...
ISSUED AT 407 AM MDT WED MAY 21 2014
FIRE CONCERNS TO REMAIN MINIMAL FOR THE REST OF THE WEEK WITH
CONDITIONS AND FUELS EXPECTED TO REMAIN NON-CRITICAL. SCATTERED
AFTERNOON AND EVENING THUNDERSTORMS WILL OCCUR ALONG AND EAST OF
THE LARAMIE RANGE MOST DAYS WITH VERY GOOD CHANCES FOR WETTING
RAINS. A MORE WIDESPREAD RAIN EVENT SATURDAY NIGHT AND SUNDAY WILL
CONTINUE TO SUPPRESS FIRE WEATHER CONCERNS THRU THE MEMORIAL DAY
WEEKEND.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...FINCH
SHORT TERM...HAHN
LONG TERM...RE
AVIATION...RE
FIRE WEATHER...HAHN