Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/21/15
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
953 PM CDT MON JUL 20 2015
.UPDATE...
UPDATE TO THE FORECAST TO REFLECT CURRENT RADAR TRENDS. THIS
EVENING...HAVE CONTINUED TO SEE ISOLATED STORMS DEVELOP AHEAD OF
THE FRONT STRETCHING FROM BATESVILLE TO WALDRON. HRRR HAS THESE
THUNDERSTORMS CONTINUING TO PUSH SOUTH AND EAST THROUGH THE NIGHT
AS THEY WEAKEN. WITH THE SLOW MOVING FRONT REMAINING IN THE AREA
AGAIN ON TUESDAY...ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL
BE POSSIBLE AGAIN ON TUESDAY.
&&
.PREV DISCUSSION... /ISSUED 916 PM CDT MON JUL 20 2015/
UPDATE...
UPDATED FOR 00Z ROUTINE AVIATION ISSUANCE
AVIATION...
SHRA/TSRA AFFECTING KHRO AND KBPK WILL CONTINUE TO WEAKEN AND
SHOULD END AROUND 04Z. EXPECT A BREAK IN THE SHOWERS FOR MOST OF
THE OVERNIGHT HOURS. SHOWERS AND STORMS MAY REDEVELOP AND AFFECT
KHRO...KBPK...AND KHOT AFTER 12Z. SCTD SHOWERS AND STORMS WILL
SPREAD ACROSS MOST OF THEN NORTHERN HALF OF THE STATE TUE
AFTERNOON. THE POTENTIAL FOR GUSTY WINDS ALONG WITH MVFR CEILINGS
AND VISIBILITIES MAY OCCUR WITH ANY THUNDERSTORM...OTHERWISE VFR
CONDITIONS EXPECTED.
PREV DISCUSSION... /ISSUED 258 PM CDT MON JUL 20 2015/
SHORT TERM...TONIGHT THROUGH THURSDAY
HIGH PRESSURE OVER THE AREA WILL MOVE SLIGHTLY WESTWARD TONGIHT
AND TUESDAY. THIS IS GOING TO ALLOW A COLD FRONT TO MOVE INTO
ARKANSAS FROM MISSOURI. THIS FRONT WILL SLOWLY WORK SOUTH THROUGH
WEDNESDAY AND STALL IN SOUTH ARKANSAS WEDNESDAY. RAIN CHANCES WILL
INCREASE ALONG AND NEAR THIS FRONT THROUGH THURSDAY. SOME
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING HEAVY RAINFALL DUE TO
ABUNDANT MOISTURE AVAILABLE.
THE HEAT ADVISORY WILL EXPIRE EARLY THIS EVENING. TEMPERATURES THE
NEXT FEW DAYS WILL BE A FEW DEGREES COOLER DUE TO CLOUD COVER AND
RAIN CHANCES...SO HEAT INDICES WILL BE LOWER.
LONG TERM...FRIDAY THROUGH MONDAY
AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL CONTINUE TO DOMINATE THE
AREA THROUGH THE EXTENDED TERM...WITH THE RIDGE CENTERED OVER THE
SOUTHERN PLAINS THROUGHOUT THE PERIOD. AS THE RIDGE SLIPS A BIT
WESTWARD...IT MAY ALLOW FOR SOME ISOLATED AFTERNOON AND EVENING
THUNDERSTORMS TO DEVELOP...ESPECIALLY ACROSS THE NERN ZONES.
OTHERWISE IT WILL REMAIN QUITE HOT...WITH AFTERNOON TEMPERATURES
TOPPING OUT IN THE UPPER 90S TO AROUND 100 ACROSS MUCH OF THE
STATE.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 73 86 70 86 / 50 40 50 50
CAMDEN AR 75 95 74 93 / 10 10 20 30
HARRISON AR 73 84 70 84 / 50 50 50 50
HOT SPRINGS AR 75 93 74 92 / 20 30 30 30
LITTLE ROCK AR 77 94 75 93 / 40 30 30 40
MONTICELLO AR 77 95 75 94 / 10 20 20 30
MOUNT IDA AR 75 92 73 91 / 20 30 20 30
MOUNTAIN HOME AR 72 84 69 84 / 60 50 50 50
NEWPORT AR 74 87 72 86 / 50 40 50 50
PINE BLUFF AR 77 94 74 93 / 30 20 30 30
RUSSELLVILLE AR 76 91 75 90 / 40 40 40 50
SEARCY AR 75 90 72 89 / 40 40 40 50
STUTTGART AR 78 93 76 92 / 40 30 30 40
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
65
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
535 AM MST SUN JUL 19 2015
.UPDATE...TO AVIATION DISCUSSION...
&&
.SYNOPSIS...
SCATTERED SHOWERS AND THUNDERSTORMS ARE FORECAST ONCE AGAIN TODAY AS
A VERY HUMID AIRMASS REMAINS IN PLACE ACROSS THE DESERT SOUTHWEST. A
GRADUAL DRYING TREND WILL COMMENCE MONDAY WITH ONLY A FEW MOUNTAIN
SHOWERS AND THUNDERSTORMS EXPECTED FOR MUCH OF THE UPCOMING WEEK.
ALONG WITH DRIER AIR WILL COME ELEVATED TEMPERATURES WITH HIGHS
APPROACHING THE 110 DEGREE MARK LATE IN THE WEEK.
&&
.DISCUSSION...
QUITE AN ACTIVE DAY ON SATURDAY WITH WIDESPREAD SHOWERS AND
THUNDERSTORMS TO THE WEST AND NORTHWEST OF THE PHOENIX METRO. SOME
LOCATIONS SAW NORTH OF 4 INCHES OF RAINFALL AND FLOODING WHILE
OTHERS SAW LITTLE TO NOTHING. TYPICAL MONSOON...HIGHLY VARIABLE
DISTRIBUTION OF RAINFALL AMOUNTS AND ASSOCIATED IMPACTS. CONVECTION
HAS LARGELY DIED OFF THIS MORNING AND WHAT`S LEFT HAS MIGRATED INTO
NORTHERN ARIZONA. MEANWHILE UPSTREAM...A NEW COMPLEX WAS DEVELOPING
AND SLOWLY BACK-BUILDING THROUGH THE GULF OF CALIFORNIA. EVEN
FARTHER UPSTREAM...WATER VAPOR IMAGERY REVEALS A SHORTWAVE TROUGH
JUST WEST OF THE BAJA SPINE.
AS MENTIONED IN A PREVIOUS DISCUSSION...HI-RES MODELS WERE
STRUGGLING A BIT BUT HAVE STARTED TO TURN THE CORNER BACK TOWARD
REALITY. LATEST FEW RUNS OF THE HRRR AND LOCALLY RUN WRF
MODELS...NOT TO MENTION LATEST 00Z SPC SSEO AND NCAR HI-RES ENSEMBLE
INDICATE RELATIVELY QUIET WEATHER THROUGH THE REST OF THE MORNING
HOURS. THERE COULD BE A FEW SHOWERS THAT TRY AND TAKE A RUN AT YUMA
AND SOUTHEAST CALIFORNIA THIS MORNING COURTESY OF OUTFLOWS FROM THE
AFOREMENTIONED SONORAN COMPLEX BUT OTHERWISE THE TREND SHOULD BE ONE
OF DECREASING RAIN CHANCES THROUGH 18Z.
AS IS TYPICALLY THE CASE AROUND HERE DURING THE SUMMER...THE BIG
QUESTION IS IF THE BOUNDARY LAYER WILL BE ABLE TO RECOVER IN TIME
FOR CONVECTION TO DEVELOP THIS AFTERNOON. GIVEN AMPLE MOISTURE AND
AN UPSTREAM SHORTWAVE FORECAST TO MOVE INTO THE AREA...I`M LEANING
TOWARD ANOTHER POTENTIALLY ACTIVE DAY NEAR THE SHORTWAVE /SOUTHEAST
CALIFORNIA/FAR SOUTHWEST ARIZONA/. THE PICTURE LOOKS LESS PROMISING
AROUND THE PHOENIX AREA WHERE NEARLY ALL ENSEMBLE MEMBERS PAINT
SHOWERS IN THE MOUNTAINS AROUND THE PHOENIX METRO WITH LITTLE TO
NOTHING IN THE METRO. I`M NOT NEARLY CONFIDENT ENOUGH TO DROP POPS
ENTIRELY /ESPECIALLY WITH PWATS IN THE 90TH PERCENTILE/ BUT GIVEN
THE WIDELY SCATTERED NATURE OF STORMS IN THE GUIDANCE...I`VE ELECTED
TO REDUCE POPS SLIGHTLY THIS AFTERNOON AND DISCONTINUE THE FLASH
FLOOD WATCH FROM MARICOPA COUNTY EASTWARD. THE WATCH WILL REMAIN IN
EFFECT WEST OF PHOENIX UNTIL 10 PM TONIGHT.
LOOKING AHEAD TO MONDAY AND BEYOND...THE REMNANT CIRCULATION
ASSOCIATED WITH DOLORES WILL USHER IN A PROLONGED PERIOD OF
UNFAVORABLE SOUTHWESTERLY FLOW ALOFT...EFFECTIVELY MIGRATING ANY
NOTEWORTHY STORM CHANCES WELL INTO THE MOUNTAINS NORTH/EAST OF
PHOENIX. COINCIDENT WITH THE DECREASING MOISTURE TREND WILL BE AN
INCREASING TEMPERATURE FORECAST. NEARLY ALL GUIDANCE BRINGS IN ABOVE
NORMAL TEMPS FROM MID WEEK ONWARD AND WITH SURFACE DEWPOINTS
FORECAST TO FALL BACK INTO THE 40S...HIGHS IN THE 105-109 RANGE SEEM
MORE THAN REASONABLE.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
BKN-OVC CIGS WILL PERSIST ACROSS THE REGION THROUGH THE LATE AM...
GNLY REMAINING AOA 10KFT. AM WINDS WILL BE ON THE LIGHT SIDE
FAVORING TYPICAL EASTERLY HEADINGS AND EVEN SOME VRB FROM TIME TO
TIME. STILL AMPLE TROPICAL MOISTURE IN PLACE ACROSS THE REGION
SUPPORTS AFTN AND EARLY EVENING SHOWER AND THUNDERSTORM
CHANCES...WITH THE CURRENT BEST THINKING FOR VC STORM ACTIVITY AROUND
THE PHX METRO LATER INTO THE AFTN...TOWARDS 20/00Z. PRIMARY THREAT
WITH STORMS TODAY WILL BE HEAVY RAINFALL AND ASSOCIATED LOWERED
CIGS/VSBYS UNDER THE STRONGER STORMS. WITH ALL THE ACTIVITY AROUND
THE AREA SATURDAY...THERE IS SOME QUESTION ABOUT HOW MUCH STORM
COVERAGE MAY MATERIALIZE TODAY...SO CONTINUED TO HEDGE WITH VCTS FOR
THE LATE EVENING AND VCSH AFTER 20/06Z.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CALM AM CONDITIONS WILL GIVE WAY TO ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS ACROSS THE REGION...POSSIBLY AS EARLY AS LATE AM FOR
THE WESTERN TERMINALS OF KIPL AND KBLH. LATEST MODEL GUIDANCE
INDICATE ACTIVITY ACROSS SOUTHEAST CA WILL RECEIVE A BOOST FROM
STORMS AND OUTFLOWS OFF THE BAJA SPINE. STORMS TODAY WILL HAVE THE
POTENTIAL TO PRODUCE VERY HEAVY RAINFALL. AREAL CIGS SHOULD RANGE IN
THE 8-12KFT RANGE DOWN TOWARDS 5KFT AND REDUCED VSBYS UNDER SHOWER
AND THUNDERSTORM ACTIVITY AT THE TERMINALS. PRECIP ACTIVITY SHOULD
GNLY WANE TOWARDS THE LATE AFTN/EVENING HOURS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
CONDITIONS WILL GRADUALLY DRY OUT STARTING MONDAY...BUT LINGERING
MOISTURE WILL PROVIDE SLIGHT CHANCES OF SHOWERS AND THUNDERSTORMS
OVER AT LEAST EASTERN ARIZONA AND POTENTIALLY PORTIONS OF SOUTH-
CENTRAL ARIZONA. FOR TUESDAY INTO FRIDAY DRIER FLOW WILL PRETTY
CONFINE THUNDERSTORM CHANCES TO THE HIGHER TERRAIN AREAS TO THE EAST
OF PHOENIX. BELOW SEASONAL NORMAL HIGH TEMPERATURES ARE EXPECTED
MONDAY BUT AS THE AIRMASS DRIES A WARMING TREND IS EXPECTED WITH
READINGS CLIMBING TO AROUND NORMAL BY THE MIDDLE OF THE WEEK.
MINIMUM HUMIDITIES WILL GRADUALLY DECREASE AND LOWER INTO THE TEENS
FOR THE MOST PART BY MIDWEEK. WINDS WILL STAY RELATIVELY LIGHT ALL
WEEK...FAVORING NORMAL SOUTHWEST TO WEST DIRECTIONS IN THE AFTERNOON
AND EVENING...WITH TYPICAL OCCASIONAL GUSTINESS.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE REQUIRED TODAY. OTHERWISE SPOTTER
ACTIVATION IS NOT EXPECTED FOR THE UPCOMING WEEK.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLASH FLOOD WATCH THROUGH THIS EVENING FOR AZZ020-021-025-026.
CA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR CAZ030>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...NOLTE
FIRE WEATHER...KUHLMAN/CB
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
152 AM MST SUN JUL 19 2015
.SYNOPSIS...
SCATTERED SHOWERS AND THUNDERSTORMS ARE FORECAST ONCE AGAIN TODAY AS
A VERY HUMID AIRMASS REMAINS IN PLACE ACROSS THE DESERT SOUTHWEST. A
GRADUAL DRYING TREND WILL COMMENCE MONDAY WITH ONLY A FEW MOUNTAIN
SHOWERS AND THUNDERSTORMS EXPECTED FOR MUCH OF THE UPCOMING WEEK.
ALONG WITH DRIER AIR WILL COME ELEVATED TEMPERATURES WITH HIGHS
APPROACHING THE 110 DEGREE MARK LATE IN THE WEEK.
&&
.DISCUSSION...
QUITE AN ACTIVE DAY ON SATURDAY WITH WIDESPREAD SHOWERS AND
THUNDERSTORMS TO THE WEST AND NORTHWEST OF THE PHOENIX METRO. SOME
LOCATIONS SAW NORTH OF 4 INCHES OF RAINFALL AND FLOODING WHILE
OTHERS SAW LITTLE TO NOTHING. TYPICAL MONSOON...HIGHLY VARIABLE
DISTRIBUTION OF RAINFALL AMOUNTS AND ASSOCIATED IMPACTS. CONVECTION
HAS LARGELY DIED OFF THIS MORNING AND WHAT`S LEFT HAS MIGRATED INTO
NORTHERN ARIZONA. MEANWHILE UPSTREAM...A NEW COMPLEX WAS DEVELOPING
AND SLOWLY BACK-BUILDING THROUGH THE GULF OF CALIFORNIA. EVEN
FARTHER UPSTREAM...WATER VAPOR IMAGERY REVEALS A SHORTWAVE TROUGH
JUST WEST OF THE BAJA SPINE.
AS MENTIONED IN A PREVIOUS DISCUSSION...HI-RES MODELS WERE
STRUGGLING A BIT BUT HAVE STARTED TO TURN THE CORNER BACK TOWARD
REALITY. LATEST FEW RUNS OF THE HRRR AND LOCALLY RUN WRF MODELS...NOT
TO MENTION LATEST 00Z SPC SSEO AND NCAR HI-RES ENSEMBLE INDICATE
RELATIVELY QUIET WEATHER THROUGH THE REST OF THE MORNING HOURS. THERE COULD
BE A FEW SHOWERS THAT TRY AND TAKE A RUN AT YUMA AND SOUTHEAST
CALIFORNIA THIS MORNING COURTESY OF OUTFLOWS FROM THE AFOREMENTIONED
SONORAN COMPLEX BUT OTHERWISE THE TREND SHOULD BE ONE OF DECREASING
RAIN CHANCES THROUGH 18Z.
AS IS TYPICALLY THE CASE AROUND HERE DURING THE SUMMER...THE BIG
QUESTION IS IF THE BOUNDARY LAYER WILL BE ABLE TO RECOVER IN TIME FOR
CONVECTION TO DEVELOP THIS AFTERNOON. GIVEN AMPLE MOISTURE AND AN
UPSTREAM SHORTWAVE FORECAST TO MOVE INTO THE AREA...I`M LEANING
TOWARD ANOTHER POTENTIALLY ACTIVE DAY NEAR THE SHORTWAVE /SOUTHEAST
CALIFORNIA/FAR SOUTHWEST ARIZONA/. THE PICTURE LOOKS LESS PROMISING
AROUND THE PHOENIX AREA WHERE NEARLY ALL ENSEMBLE MEMBERS PAINT
SHOWERS IN THE MOUNTAINS AROUND THE PHOENIX METRO WITH LITTLE TO
NOTHING IN THE METRO. I`M NOT NEARLY CONFIDENT ENOUGH TO DROP POPS
ENTIRELY /ESPECIALLY WITH PWATS IN THE 90TH PERCENTILE/ BUT GIVEN THE
WIDELY SCATTERED NATURE OF STORMS IN THE GUIDANCE...I`VE ELECTED TO
REDUCE POPS SLIGHTLY THIS AFTERNOON AND DISCONTINUE THE FLASH FLOOD
WATCH FROM MARICOPA COUNTY EASTWARD. THE WATCH WILL REMAIN IN EFFECT
WEST OF PHOENIX UNTIL 10 PM TONIGHT.
LOOKING AHEAD TO MONDAY AND BEYOND...THE REMNANT CIRCULATION
ASSOCIATED WITH DOLORES WILL USHER IN A PROLONGED PERIOD OF
UNFAVORABLE SOUTHWESTERLY FLOW ALOFT...EFFECTIVELY MIGRATING ANY
NOTEWORTHY STORM CHANCES WELL INTO THE MOUNTAINS NORTH/EAST OF
PHOENIX. COINCIDENT WITH THE DECREASING MOISTURE TREND WILL BE AN
INCREASING TEMPERATURE FORECAST. NEARLY ALL GUIDANCE BRINGS IN ABOVE
NORMAL TEMPS FROM MID WEEK ONWARD AND WITH SURFACE DEWPOINTS FORECAST
TO FALL BACK INTO THE 40S...HIGHS IN THE 105-109 RANGE SEEM MORE THAN
REASONABLE.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL... AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
HURRICANE MOISTURE THAT SPREAD OVER THE REGION IS NOW CONSIDERED
EXCESSIVE. VARIABLE CLOUDS AOA 8 THSD AGL...WITH ISOLATED SHOWERS
AND THUNDERSTORMS ARE FORECAST THROUGH 18Z SUN. THE CHANCE OF
SHOWERS AND THUNDERSTORMS WITH CIGS NEAR 5 THSD AGL IN TSTMS WILL
INCREASE SUNDAY AFTERNOON AND EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
CONDITIONS WILL GRADUALLY DRY OUT STARTING MONDAY...BUT LINGERING
MOISTURE WILL PROVIDE SLIGHT CHANCES OF SHOWERS AND THUNDERSTORMS
OVER AT LEAST EASTERN ARIZONA AND POTENTIALLY PORTIONS OF SOUTH-
CENTRAL ARIZONA. FOR TUESDAY INTO FRIDAY DRIER FLOW WILL PRETTY
CONFINE THUNDERSTORM CHANCES TO THE HIGHER TERRAIN AREAS TO THE EAST
OF PHOENIX. BELOW SEASONAL NORMAL HIGH TEMPERATURES ARE EXPECTED
MONDAY BUT AS THE AIRMASS DRIES A WARMING TREND IS EXPECTED WITH
READINGS CLIMBING TO AROUND NORMAL BY THE MIDDLE OF THE WEEK.
MINIMUM HUMIDITIES WILL GRADUALLY DECREASE AND LOWER INTO THE TEENS
FOR THE MOST PART BY MIDWEEK. WINDS WILL STAY RELATIVELY LIGHT ALL
WEEK...FAVORING NORMAL SOUTHWEST TO WEST DIRECTIONS IN THE AFTERNOON
AND EVENING...WITH TYPICAL OCCASIONAL GUSTINESS.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE REQUIRED TODAY. OTHERWISE SPOTTER
ACTIVATION IS NOT EXPECTED FOR THE UPCOMING WEEK.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLASH FLOOD WATCH THROUGH THIS EVENING FOR AZZ020-021-025-026.
CA...FLASH FLOOD WATCH THROUGH THIS EVENING FOR CAZ030>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...VASQUEZ
FIRE WEATHER...KUHLMAN/CB
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
1156 AM PDT SUN JUL 19 2015
.SYNOPSIS...MOISTURE FROM TROPICAL STORM DOLORES OFF THE COAST
OF MEXICO IS FORECAST TO CONTINUE TO MOVE NORTH THROUGH TOMORROW.
THIS TROPICAL MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS GENERALLY SOUTH OF SAN FRANCISCO BAY.
&&
.DISCUSSION...AS OF 8:50 AM PDT SUNDAY...ACTIVE MORNING SO FAR
WITH NUMEROUS SHOWERS AND THUNDERSTORMS OVER MONTEREY COUNTY. HAVE
BEEN WATCHING THE RADAR CLOSELY BUT SO FAR CELLS HAVE SHOWN LITTLE
SIGN OF ADVANCING NORTH TO SANTA CRUZ OR SANTA CLARA COUNTY.
LATEST IMAGES ALSO SHOW THAT OVERALL ACTIVITY IS ON THE DECREASE.
SATELLITE AND RADAR PLUS LIGHTNING DATA SHOW A LARGE CLUSTER OF
SHOWERS AND THUNDERSTORMS IN SLO COUNTY AND OFF THEIR COAST. THIS
IS FORECAST TO MOVE NORTHWARD INTO MONTEREY COUNTY LATE THIS
MORNING AND CONTINUE INTO THE AFTERNOON. ALTHOUGH HRRR DID NOT
INITIALIZE WELL FOR THE CONVECTION IN OUR CWA...IT SEEMS TO BE
DOING WELL FOR THE AREA TO OUR SOUTH. SO WILL HEAVILY WEIGHT THE
FORECAST TOWARD IT FOR THE NEXT 12 HOURS. ITS LATEST RUN KEEPS
ALMOST ALL ACTIVITY FROM SANTA CRUZ TO THE SOUTH. WILL ISSUE A
FORECAST UPDATE FOR POPS BASED OFF OF LATEST GUIDANCE.
.PREVIOUS DISCUSSION...MOISTURE FROM THE REMNANTS OF TROPICAL
SYSTEM DOLORES CONTINUES TO FLOW NORTHWARD INTO CALIFORNIA.
ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPED ACROSS SOUTHERN AND
EASTERN PORTIONS OF OUR FORECAST AREA LAST EVENING...AND CONTINUED
THROUGH THE EARLY MORNING HOURS OF SUNDAY. AN ISOLATED
THUNDERSTORM DEVELOPED AS FAR NORTH AS CONTRA COSTA COUNTY SHORTLY
AFTER MIDNIGHT. SINCE THEN...CONVECTIVE ACTIVITY HAS PRETTY MUCH
ENDED OVER OUR AREA. BUT RECENTLY AN AREA OF WIDESPREAD SHOWERS
AND SCATTERED THUNDERSTORMS TO OUR SOUTH OVER SAN LUIS OBISPO
COUNTY HAS BEGUN TO PRESS NORTHWARD INTO FAR SOUTHERN MONTEREY
COUNTY. SHOWER AND THUNDERSTORM ACTIVITY IS FORECAST TO SPREAD
NORTH TODAY AS TROPICAL MOISTURE CONTINUES TO INCREASE FROM THE
SOUTH. THE SPECIFICS ON WHEN AND WHERE CONVECTIVE PRECIP WILL FALL
IS TOUGH TO PIN DOWN AS THIS WILL DEPEND ON WHERE WEAK FORCING
INITIATES CONVECTIVE DEVELOPMENT. BUT THE GENERAL IDEA PUT FORTH
BY THE MODELS IS FOR SHOWERS AND THUNDERSTORMS TO OVERSPREAD MUCH
OF OUR FORECAST AREA SOUTH OF SAN JOSE TODAY...WITH SOME ISOLATED
ACTIVITY FARTHER TO THE NORTH. IT APPEARS THEN THAT THERE WILL BE
A BIT OF A LULL IN THE CONVECTIVE PRECIP ACTIVITY TONIGHT...EXCEPT
PERHAPS ACROSS THE FAR SOUTH. SHOWERS/THUNDERSTORMS ARE THEN
FORECAST TO INCREASE ONCE AGAIN ON MONDAY AS A WEAK UPPER LOW
OFFSHORE LIFTS TO THE NORTHEAST AND APPROACHES THE BIG SUR COAST.
BUT ONCE AGAIN ON MONDAY...MOST OF THE ACTIVITY IS EXPECTED TO BE
ACROSS THE SOUTHERN PART OF OUR AREA. SHOWERS AND ISOLATED
THUNDERSTORMS WILL THEN GRADUALLY TAPER OFF ON MONDAY NIGHT. ALL
PRECIP SHOULD THEN END BY TUESDAY AS A DRIER WESTERLY FLOW
DEVELOPS ALOFT. HOWEVER...THE 00Z GFS PRODUCES SOME LINGERING
CONVECTIVE PRECIP ACROSS THE FAR SOUTHEAST PORTION OF OUR CWA ON
TUESDAY AFTERNOON.
THE NAM AND GFS FORECAST AS MUCH AS AN INCH OF PRECIPITATION
ACROSS PORTIONS OF MONTEREY AND SAN BENITO COUNTIES BY LATE MONDAY
NIGHT. PRECIP TOTALS FARTHER TO THE NORTH ARE FORECAST TO BE
CONSIDERABLY LESS. HOWEVER...DUE TO THE CONVECTIVE NATURE OF THE
PRECIP...AMOUNTS WILL LIKELY VARY CONSIDERABLY EVEN ACROSS THE
SOUTHERN PART OF OUR AREA. BRIEF HEAVY DOWNPOURS ARE LIKELY OVER
THE NEXT FEW DAYS GIVEN THE VERY MOIST NATURE OF THE INCOMING
AIRMASS. PRECIPITABLE WATER VALUES ARE ALREADY IN EXCESS OF 1.5
INCHES ACROSS THE FAR SOUTHERN PART OF OUR AREA...AND PW`S UP TO 2
INCHES ARE CURRENTLY BEING OBSERVED AS CLOSE AS SANTA BARBARA
COUNTY. FORTUNATELY FOR FIRE WEATHER CONCERNS...LIGHTNING WILL
LIKELY BE ACCOMPANIED BY WETTING RAINS.
MODEL GUIDANCE IS IN PRETTY GOOD AGREEMENT IN FORECASTING WARM
TEMPERATURES TODAY...PARTICULARLY ACROSS THE NORTHERN TWO-THIRDS
OF OUR AREA WHERE THERE SHOULD BE ENOUGH SUN. HIGH TEMPERATURES
ARE EXPECTED TO BE MOSTLY IN THE 70S TO LOWER 80S NEAR THE
COAST...AND IN THE 80S AND LOWER 90S INLAND. MEANWHILE...SURFACE
DEWPOINTS ARE FORECAST TO CLIMB INTO THE LOWER 60S TODAY. THE
COMBINATION OF WARM TEMPERATURES AND HIGHER THAN NORMAL DEWPOINTS
WILL MEAN UNCOMFORTABLY MUGGY CONDITIONS FROM LATER TODAY THROUGH
MONDAY EVENING. LOW TEMPERATURES TONIGHT ARE EXPECTED TO MOSTLY
BE IN THE MID AND UPPER 60S...WITH SOME LOWER 70S LIKELY. RELIEF
FROM THE MUGGY CONDITIONS WILL ARRIVE ON TUESDAY AS A DRIER
AIRMASS BEGINS TO FILTER IN FROM THE WEST.
A DRY UPPER TROUGH IS FORECAST TO SETTLE IN ALONG THE WEST COAST
BY MIDWEEK...WHICH WILL RESULT IN SLIGHTLY COOLER THAN NORMAL
TEMPS INLAND FROM TUESDAY THROUGH THURSDAY. WARMING IS THEN
EXPECTED LATE IN THE WEEK AND INTO NEXT WEEKEND AS A RIDGE OVER
THE SOUTHWESTERN STATES EXPANDS WESTWARD OVER CA.
&&
.AVIATION...AS OF 11:55 AM PDT SUNDAY...FOR 18Z TAFS. FORECAST
FOCUS IS ON CONVECTION AND SHOWERS OVER SLO COUNTY SPREADING
NORTHWARD INTO MONTEREY BAY REGION WITH ISOLATED ACTIVITY OVER BAY
AREA. CLOUD HEIGHTS ARE HIGH SO CONDITIONS REMAIN VFR. EARLIER
CONVECTION HAS ENDED BUT RENWED T-STORM CHANCES REMAIN POSSIBLE
MOST LIKELY FOR KMRY AND KSNS. AREA OF PRECIP TO SOUTH LOOKS MORE
STRATIFORM BUT ISOLATED CELLS NOW STARTING TO FIRE NEAR THE SF AND
MARIN COUNTY VICINITY.
VICINITY OF KSFO...VFR WITH HIGH CLOUDS. WILL NEED TO MONITOR ANY
POSSIBLE SHOWERS OR CONVECTION COMING IN FROM SOUTH BUT FOR NOW
MAIN ACTIVITY LOOKS TO MISS TERMINAL THIS AFTERNOON AND EVENING.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR WITH MAINLY HIGH CLOUDS. PRECIP
SHIELD TO SOUTH MAY OVERSPREAD AND BRING PERIOD OF STEADY LIGHT
RAIN OR -SHRA LATER THIS AFTERNOON AND EVENING. CLOUD SHIELD MAY
LIMIT T-STORM POTENTIAL AND CURRENT TAF WILL SHOW TEMP -TSRA.
&&
.BEACHES...AS OF 5:01 AM PDT SUNDAY...SOUTHERLY SWELL WILL SPREAD
UP THE COASTLINE TODAY PERSISTING INTO THE FIRST HALF OF THE WEEK.
AS PREVIOUSLY MENTIONED THIS SWELL WILL NOT BE VERY LARGE...3 TO
5 FEET...AND THE PERIOD IS ONLY EXPECTED TO BE 10 TO 12 SECONDS.
HOWEVER...THE SWELL WILL PARALLEL THE COAST AND WILL BE
ACCOMPANIED BY SOUTHERLY WINDS TODAY RESULTING IN LONG SHORE
CURRENTS RUNNING SOUTH TO NORTH ALONG THE COASTLINE WITH STRONGER
THAN USUAL RIP CURRENTS ANTICIPATED AT SANTA CRUZ BEACHES AND
POSSIBLY STINSON BEACH. WINDS ARE EXPECTED TO BECOME NORTHERLY
OVERNIGHT WHICH SHOULD DISRUPT THE LONG SHORE CURRENT ON MONDAY.
POTENTIALLY THE BIGGEST HAZARD AT THE BEACH TODAY WILL BE
LIGHTNING AS TROPICAL MOISTURE MOVES THROUGH THE AREA GENERATING
THUNDERSTORMS. IF YOU HEAR THUNDER OR SEE LIGHTNING PLEASE LEAVE
THE BEACH AND SEEK SHELTER FROM THE STORM.
&&
.MARINE...AS OF 11:42 AM PDT SUNDAY...A WEAK SURFACE PRESSURE
GRADIENT WILL MAINTAIN GENERALLY LIGHT SOUTHERLY WINDS AND GENTLE
SEAS ACROSS THE COASTAL WATERS TODAY. SHOWERS AND ISOLATED
THUNDERSTORMS WILL BE POSSIBLE TODAY AS MONSOON MOISTURE PASSES
OVER THE AREA. WINDS WILL BEGIN TO INCREASE OUT OF THE NORTHERLY
DIRECTION OVERNIGHT AS THE SURFACE PRESSURE GRADIENT STRENGTHENS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...NONE.
$$
PUBLIC FORECAST: BELL
AVIATION: RWW
MARINE: RWW
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
854 AM PDT SUN JUL 19 2015
.SYNOPSIS...MOISTURE FROM TROPICAL STORM DOLORES OFF THE COAST
OF MEXICO IS FORECAST TO CONTINUE TO MOVE NORTH THROUGH TOMORROW.
THIS TROPICAL MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS GENERALLY SOUTH OF SAN FRANCISCO BAY.
&&
.DISCUSSION...AS OF 8:50 AM PDT SUNDAY...ACTIVE MORNING SO FAR
WITH NUMEROUS SHOWERS AND THUNDERSTORMS OVER MONTEREY COUNTY. HAVE
BEEN WATCHING THE RADAR CLOSELY BUT SO FAR CELLS HAVE SHOWN LITTLE
SIGN OF ADVANCING NORTH TO SANTA CRUZ OR SANTA CLARA COUNTY.
LATEST IMAGES ALSO SHOW THAT OVERALL ACTIVITY IS ON THE DECREASE.
SATELLITE AND RADAR PLUS LIGHTNING DATA SHOW A LARGE CLUSTER OF
SHOWERS AND THUNDERSTORMS IN SLO COUNTY AND OFF THEIR COAST. THIS
IS FORECAST TO MOVE NORTHWARD INTO MONTEREY COUNTY LATE THIS
MORNING AND CONTINUE INTO THE AFTERNOON. ALTHOUGH HRRR DID NOT
INITIALIZE WELL FOR THE CONVECTION IN OUR CWA...IT SEEMS TO BE
DOING WELL FOR THE AREA TO OUR SOUTH. SO WILL HEAVILY WEIGHT THE
FORECAST TOWARD IT FOR THE NEXT 12 HOURS. ITS LATEST RUN KEEPS
ALMOST ALL ACTIVITY FROM SANTA CRUZ TO THE SOUTH. WILL ISSUE A
FORECAST UPDATE FOR POPS BASED OFF OF LATEST GUIDANCE.
.PREVIOUS DISCUSSION...MOISTURE FROM THE REMNANTS OF TROPICAL
SYSTEM DOLORES CONTINUES TO FLOW NORTHWARD INTO CALIFORNIA.
ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPED ACROSS SOUTHERN AND
EASTERN PORTIONS OF OUR FORECAST AREA LAST EVENING...AND CONTINUED
THROUGH THE EARLY MORNING HOURS OF SUNDAY. AN ISOLATED
THUNDERSTORM DEVELOPED AS FAR NORTH AS CONTRA COSTA COUNTY SHORTLY
AFTER MIDNIGHT. SINCE THEN...CONVECTIVE ACTIVITY HAS PRETTY MUCH
ENDED OVER OUR AREA. BUT RECENTLY AN AREA OF WIDESPREAD SHOWERS
AND SCATTERED THUNDERSTORMS TO OUR SOUTH OVER SAN LUIS OBISPO
COUNTY HAS BEGUN TO PRESS NORTHWARD INTO FAR SOUTHERN MONTEREY
COUNTY. SHOWER AND THUNDERSTORM ACTIVITY IS FORECAST TO SPREAD
NORTH TODAY AS TROPICAL MOISTURE CONTINUES TO INCREASE FROM THE
SOUTH. THE SPECIFICS ON WHEN AND WHERE CONVECTIVE PRECIP WILL FALL
IS TOUGH TO PIN DOWN AS THIS WILL DEPEND ON WHERE WEAK FORCING
INITIATES CONVECTIVE DEVELOPMENT. BUT THE GENERAL IDEA PUT FORTH
BY THE MODELS IS FOR SHOWERS AND THUNDERSTORMS TO OVERSPREAD MUCH
OF OUR FORECAST AREA SOUTH OF SAN JOSE TODAY...WITH SOME ISOLATED
ACTIVITY FARTHER TO THE NORTH. IT APPEARS THEN THAT THERE WILL BE
A BIT OF A LULL IN THE CONVECTIVE PRECIP ACTIVITY TONIGHT...EXCEPT
PERHAPS ACROSS THE FAR SOUTH. SHOWERS/THUNDERSTORMS ARE THEN
FORECAST TO INCREASE ONCE AGAIN ON MONDAY AS A WEAK UPPER LOW
OFFSHORE LIFTS TO THE NORTHEAST AND APPROACHES THE BIG SUR COAST.
BUT ONCE AGAIN ON MONDAY...MOST OF THE ACTIVITY IS EXPECTED TO BE
ACROSS THE SOUTHERN PART OF OUR AREA. SHOWERS AND ISOLATED
THUNDERSTORMS WILL THEN GRADUALLY TAPER OFF ON MONDAY NIGHT. ALL
PRECIP SHOULD THEN END BY TUESDAY AS A DRIER WESTERLY FLOW
DEVELOPS ALOFT. HOWEVER...THE 00Z GFS PRODUCES SOME LINGERING
CONVECTIVE PRECIP ACROSS THE FAR SOUTHEAST PORTION OF OUR CWA ON
TUESDAY AFTERNOON.
THE NAM AND GFS FORECAST AS MUCH AS AN INCH OF PRECIPITATION
ACROSS PORTIONS OF MONTEREY AND SAN BENITO COUNTIES BY LATE MONDAY
NIGHT. PRECIP TOTALS FARTHER TO THE NORTH ARE FORECAST TO BE
CONSIDERABLY LESS. HOWEVER...DUE TO THE CONVECTIVE NATURE OF THE
PRECIP...AMOUNTS WILL LIKELY VARY CONSIDERABLY EVEN ACROSS THE
SOUTHERN PART OF OUR AREA. BRIEF HEAVY DOWNPOURS ARE LIKELY OVER
THE NEXT FEW DAYS GIVEN THE VERY MOIST NATURE OF THE INCOMING
AIRMASS. PRECIPITABLE WATER VALUES ARE ALREADY IN EXCESS OF 1.5
INCHES ACROSS THE FAR SOUTHERN PART OF OUR AREA...AND PW`S UP TO 2
INCHES ARE CURRENTLY BEING OBSERVED AS CLOSE AS SANTA BARBARA
COUNTY. FORTUNATELY FOR FIRE WEATHER CONCERNS...LIGHTNING WILL
LIKELY BE ACCOMPANIED BY WETTING RAINS.
MODEL GUIDANCE IS IN PRETTY GOOD AGREEMENT IN FORECASTING WARM
TEMPERATURES TODAY...PARTICULARLY ACROSS THE NORTHERN TWO-THIRDS
OF OUR AREA WHERE THERE SHOULD BE ENOUGH SUN. HIGH TEMPERATURES
ARE EXPECTED TO BE MOSTLY IN THE 70S TO LOWER 80S NEAR THE
COAST...AND IN THE 80S AND LOWER 90S INLAND. MEANWHILE...SURFACE
DEWPOINTS ARE FORECAST TO CLIMB INTO THE LOWER 60S TODAY. THE
COMBINATION OF WARM TEMPERATURES AND HIGHER THAN NORMAL DEWPOINTS
WILL MEAN UNCOMFORTABLY MUGGY CONDITIONS FROM LATER TODAY THROUGH
MONDAY EVENING. LOW TEMPERATURES TONIGHT ARE EXPECTED TO MOSTLY
BE IN THE MID AND UPPER 60S...WITH SOME LOWER 70S LIKELY. RELIEF
FROM THE MUGGY CONDITIONS WILL ARRIVE ON TUESDAY AS A DRIER
AIRMASS BEGINS TO FILTER IN FROM THE WEST.
A DRY UPPER TROUGH IS FORECAST TO SETTLE IN ALONG THE WEST COAST
BY MIDWEEK...WHICH WILL RESULT IN SLIGHTLY COOLER THAN NORMAL
TEMPS INLAND FROM TUESDAY THROUGH THURSDAY. WARMING IS THEN
EXPECTED LATE IN THE WEEK AND INTO NEXT WEEKEND AS A RIDGE OVER
THE SOUTHWESTERN STATES EXPANDS WESTWARD OVER CA.
&&
.AVIATION...AS OF 4:54 AM PDT SUNDAY...THE CURRENT SATELLITE
BLENDED TOTAL PRECIPITABLE WATER IMAGE IS SHOWING PLENTY OF
TROPICAL MOISTURE PUSHING NORTH INTO MONTEREY COUNTY THIS MORNING.
THIS IS RESULTING IN SOME THUNDERSTORM DEVELOPMENT WHICH IS
EXPECTED TO IMPACT THE TERMINALS TODAY...PRIMARILY FROM SAN JOSE
SOUTH. CLOUD DECKS SHOULD REMAIN FAIRLY HIGH THROUGHOUT THE DAY
TODAY WITH LITTLE TO NO LOW CLOUDS EXPECTED.
VICINITY OF KSFO...VFR...BKN-OVC150. THE SEA BREEZE IS EXPECTED TO
REACH 12 TO 18 KT THIS AFTERNOON WITH GUSTS TO 25 KT. EXPECT TO
SEE TOWERING CUMULUS TODAY WITH LIGHTNING DISTANT.
CONFIDENCE IS HIGH.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR...SCT-BKN070 AND BKN-OVC150
EXPECTED TO PREVAIL TODAY. THE SEA BREEZE IS EXPECTED TO REACH 8
TO 12 KT THIS AFTERNOON WITH GUSTS TO 18 KT. EXPECTED TO SEE
PLENTY OF TOWERING CUMULUS TODAY WITH LIGHTNING POSSIBLE IN THE
VICINITY OF THE TERMINALS.
CONFIDENCE IS HIGH.
&&
.BEACHES...AS OF 5:01 AM PDT SUNDAY...SOUTHERLY SWELL WILL SPREAD
UP THE COASTLINE TODAY PERSISTING INTO THE FIRST HALF OF THE WEEK.
AS PREVIOUSLY MENTIONED THIS SWELL WILL NOT BE VERY LARGE...3 TO
5 FEET...AND THE PERIOD IS ONLY EXPECTED TO BE 10 TO 12 SECONDS.
HOWEVER...THE SWELL WILL PARALLEL THE COAST AND WILL BE
ACCOMPANIED BY SOUTHERLY WINDS TODAY RESULTING IN LONG SHORE
CURRENTS RUNNING SOUTH TO NORTH ALONG THE COASTLINE WITH STRONGER
THAN USUAL RIP CURRENTS ANTICIPATED AT SANTA CRUZ BEACHES AND
POSSIBLY STINSON BEACH. WINDS ARE EXPECTED TO BECOME NORTHERLY
OVERNIGHT WHICH SHOULD DISRUPT THE LONG SHORE CURRENT ON MONDAY.
POTENTIALLY THE BIGGEST HAZARD AT THE BEACH TODAY WILL BE
LIGHTNING AS TROPICAL MOISTURE MOVES THROUGH THE AREA GENERATING
THUNDERSTORMS. IF YOU HEAR THUNDER OR SEE LIGHTNING PLEASE LEAVE
THE BEACH AND SEEK SHELTER FROM THE STORM.
&&
.MARINE...AS OF 08:44 AM PDT SUNDAY...A WEAK SURFACE PRESSURE
GRADIENT WILL MAINTAIN GENERALLY LIGHT SOUTHERLY WINDS AND GENTLE
SEAS ACROSS THE COASTAL WATERS TODAY. SHOWERS AND ISOLATED
THUNDERSTORMS WILL BE POSSIBLE TODAY AS MONSOON MOISTURE PASSES
OVER THE AREA. PLEASE REMEMBER THAT WINDS CAN INCREASE AND SWITCH
DIRECTION SUDDENLY IN THE VICINITY OF THUNDERSTORMS. OTHERWISE
WINDS WILL BEGIN TO INCREASE OUT OF THE NORTHERLY DIRECTION
OVERNIGHT AS THE SURFACE PRESSURE GRADIENT STRENGTHENS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
$$
PUBLIC FORECAST: BELL/DYKEMA
AVIATION: LARRY
MARINE: LARRY
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION
NWS LOS ANGELES/OXNARD CA
1050 PM PDT SAT JUL 18 2015
...AVIATION DISCUSSION UPDATED...
.SYNOPSIS...
WARM AND HUMID CONDITIONS WILL LINGER THROUGH EARLY NEXT WEEK AS
MOISTURE FROM TROPICAL DEPRESSION DOLORES STREAMS OVER THE
AREA...ALONG WITH PLENTY OF CLOUDS AND SCATTERED THUNDERSTORMS AT
TIMES. LESS HUMID CONDITIONS WILL RETURN BY MID WEEK AS THE TROPICAL
AIRMASS MOVES EAST. TEMPERATURES WILL REMAIN NEAR SEASONAL NORMALS
THROUGH THE END OF THE WEEK.
&&
.UPDATE...
LATEST INFRARED SATELLITE IMAGERY AND THE LATEST INFORMATION FROM
THE NATIONAL HURRICANE CENTER INDICATES THE CENTER OF NOW TROPICAL
DEPRESSION DOLORES ABOUT 550 MILES SOUTH OF LOS ANGELES. A WARM AND
HUMID AIR MASS REMAINS IN PLACE ACROSS THE AREA AND THE AIR MASS
WILL SPREAD FARTHER NORTH THROUGH SUNDAY MORNING. MODEL ARE IN
AGREEMENT WITH THE ANOTHER VORTICITY MAXIMUM SPREADING NORTH INTO
THE AREA EARLY SUNDAY MORNING AND INCREASING SHOWER ACTIVITY. HRRR
AND RAP MODEL SOLUTIONS DEVELOP PRECIPITATION ACROSS THE COASTAL
WATERS JUST BEFORE DAYBREAK SUNDAY AND PUSH IT NORTH INTO THE AREA.
POPS HAVE BEEN NUDGED TO REFLECT THE CURRENT THINKING. DAYTIME
HEATING WILL LIKELY BE CUT INTO SOME ESPECIALLY NORTH OF POINT
CONCEPTION. TEMPERATURES HAVE BEEN NUDGED DOWN BUT THERE IS A CHANCE
THAT HIGH TEMPERATURES FOR SUNDAY COULD BE TOO WARM. IF THE CLOUD
SHIELD STICKS AROUND MORE THAN EXPECTED...SOLAR ENERGY WILL HAVE
DIFFICULTY REACHING THE SURFACE.
FLASH FLOOD WATCH REMAINS IN EFFECT BUT WAS EXPANDED TO INCLUDE THE
COLBY AND SPRINGS BURN AREAS THROUGH MONDAY. RAINFALL RATES IN
EXCESS OF ONE INCH PER HOUR ARE POSSIBLE THROUGH MONDAY. STEERING
FLOW SHOULD BE SLIGHTLY LIGHTER ON SUNDAY...SO THE WATCH LOOKS
AGREEABLE AT THIS TIME.
&&
.PREV DISCUSSION...
SHORT TERM...AS FAR AS TEMPS GO...HIGH TEMPS SHOULD BE SIMILAR FOR
SUNDAY...WITH SOME WARMING EXPECTED ON MONDAY AS CLOUD COVER SHOULD
BE SLIGHTLY LESS FOR COAST AND VALLEYS...BUT STILL MOSTLY CLOUDY
ACROSS THE MOUNTAINS. OVERNIGHT NIGHT LOWS WILL BE IN THE 70S IN
SOME ELEVATED VALLEYS...LOWER MOUNTAIN ELEVATIONS AND THE ANTELOPE
VALLEY. IT WILL BE QUITE UNCOMFORTABLE.
BY TUESDAY...THE LAST REMNANTS OF DOLORES WILL HAVE MOVED INTO
CENTRAL CALIFORNIA AS A WEAK TROUGH. HIGH TEMPS SHOULD COOL A TAD
AND MOST OF THE SUB=TROPICAL MOISTURE SHOULD BE WELL TO THE NORTH
AND EAST OF THE FORECAST AREA. THERE WILL BE A SLIGHT CHANCE FOR
LINGERING MID LEVEL MOISTURE TO SET OFF ISOLATED THUNDERSTORMS IN
THE MOUNTAINS.
THERE WILL BE A CHANCE FOR LOW CLOUDS TO REDEVELOP ALONG THE COAST
TUE NIGHT INTO WED.
.LONG TERM...BOTH THE GFS AND ECMWF SHOW A BROAD UPPER TROUGH TO THE
NORTHWEST WHILE THE UPPER RIDGE AXIS FROM TEXAS WILL CONTINUE TO
NUDGE WESTWARD INTO EXTREME SOUTHERN CALIFORNIA. THIS IS A TYPICAL
SYNOPTIC PATTERN FOR THIS TIME OF YEAR. IN THIS CASE THE THE UPPER
RIDGE WILL START TO EXPAND BY THURSDAY UNDERCUTTING THE TROUGH. THIS
WILL CAUSE HIGH TEMPS TO BUMP UP A FEW DEGREES ACROSS INLAND
AREAS...WITH CONTINUED LOW CLOUDS AND FOG ALONG THE COASTAL AREAS
AND POSSIBLY INTO A FEW COASTAL VALLEYS. HIGH TEMPS WILL BE MORE
NORMAL BY MID WEEK...WITH MUCH LESS IN THE WAY HUMIDITY.
&&
.AVIATION...19/06Z.
AT 05Z AT KLAX...THERE WAS NO INVERSION.
OVERALL... LOW TO MODERATE CONFIDENCE IN THE 06Z TAFS. THE PRIMARY
UNCERTAINTY IS DUE TO SHOWERS AND THUNDERSTORMS ACROSS THE REGION.
MVFR CONDITIONS ARE POSSIBLE IN MOST LOCATIONS BUT WITH A CHANCE OF
A LOWER VISIBILITY IN STRONGER SHOWERS.
KLAX...LOW TO MODERATE CONFIDENCE IN THE 06Z TAF. THE PRIMARY
UNCERTAINTY IS DUE TO SHOWER AND THUNDERSTORM ACTIVITY. MVFR
CONDITIONS ARE POSSIBLE AT TIMES WITH A CHANCE OF A LOWER VISIBILITY
IN STRONGER STORMS.
KBUR... LOW TO MODERATE CONFIDENCE IN THE 06Z TAF. THE PRIMARY
UNCERTAINTY IS DUE TO SHOWER AND THUNDERSTORM ACTIVITY. MVFR
CONDITIONS ARE POSSIBLE AT TIMES WITH A CHANCE OF A LOWER VISIBILITY
IN STRONGER STORMS.
&&
.MARINE...19/900 PM
WINDS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVEL THROUGH THE
WEEKEND AND INTO MONDAY. NORTHWEST WINDS WILL GRADUALLY INCREASE
BEGINNING LATE MONDAY. THERE IS MODERATE CONFIDENCE IN NORTHWEST
WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS OVER THE OUTER
WATERS FROM TUESDAY NIGHT THROUGH THURSDAY.
A SOUTHEASTERLY SWELL FROM CURRENT TROPICAL DEPRESSION DOLORES WILL
CONTINUE TO MOVE ACROSS THE COASTAL WATERS...PEAKING SUNDAY NIGHT
AND MONDAY BEFORE DIMINISHING TUESDAY. A SLIGHT CHANCE OF
THUNDERSTORMS WILL CONTINUE ACROSS THE WATERS THROUGH MONDAY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH (SEE LAXFFALOX).
BEACH HAZARDS STATEMENT (SEE LAXCFWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
&&
$$
PUBLIC...HALL/KAPLAN
AVIATION...KJ
MARINE...HALL/SMITH
SYNOPSIS...HALL/SUKUP
WWW.WEATHER.GOV/LOSANGELES
SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION...UPDATED
NWS LOS ANGELES/OXNARD CA
936 PM PDT SAT JUL 18 2015
.SYNOPSIS...
WARM AND HUMID CONDITIONS WILL LINGER THROUGH EARLY NEXT WEEK AS
MOISTURE FROM TROPICAL DEPRESSION DOLORES STREAMS OVER THE
AREA...ALONG WITH PLENTY OF CLOUDS AND SCATTERED THUNDERSTORMS AT
TIMES. LESS HUMID CONDITIONS WILL RETURN BY MID WEEK AS THE TROPICAL
AIRMASS MOVES EAST. TEMPERATURES WILL REMAIN NEAR SEASONAL NORMALS
THROUGH THE END OF THE WEEK.
&&
.UPDATE...
LATEST INFRARED SATELLITE IMAGERY AND THE LATEST INFORMATION FROM
THE NATIONAL HURRICANE CENTER INDICATES THE CENTER OF NOW TROPICAL
DEPRESSION DOLORES ABOUT 550 MILES SOUTH OF LOS ANGELES. A WARM AND
HUMID AIR MASS REMAINS IN PLACE ACROSS THE AREA AND THE AIR MASS
WILL SPREAD FARTHER NORTH THROUGH SUNDAY MORNING. MODEL ARE IN
AGREEMENT WITH THE ANOTHER VORTICITY MAXIMUM SPREADING NORTH INTO
THE AREA EARLY SUNDAY MORNING AND INCREASING SHOWER ACTIVITY. HRRR
AND RAP MODEL SOLUTIONS DEVELOP PRECIPITATION ACROSS THE COASTAL
WATERS JUST BEFORE DAYBREAK SUNDAY AND PUSH IT NORTH INTO THE AREA.
POPS HAVE BEEN NUDGED TO REFLECT THE CURRENT THINKING. DAYTIME
HEATING WILL LIKELY BE CUT INTO SOME ESPECIALLY NORTH OF POINT
CONCEPTION. TEMPERATURES HAVE BEEN NUDGED DOWN BUT THERE IS A CHANCE
THAT HIGH TEMPERATURES FOR SUNDAY COULD BE TOO WARM. IF THE CLOUD
SHIELD STICKS AROUND MORE THAN EXPECTED...SOLAR ENERGY WILL HAVE
DIFFICULTY REACHING THE SURFACE.
FLASH FLOOD WATCH REMAINS IN EFFECT BUT WAS EXPANDED TO INCLUDE THE
COLBY AND SPRINGS BURN AREAS THROUGH MONDAY. RAINFALL RATES IN
EXCESS OF ONE INCH PER HOUR ARE POSSIBLE THROUGH MONDAY. STEERING
FLOW SHOULD BE SLIGHTLY LIGHTER ON SUNDAY...SO THE WATCH LOOKS
AGREEABLE AT THIS TIME.
&&
.PREV DISCUSSION...
SHORT TERM...AS FAR AS TEMPS GO...HIGH TEMPS SHOULD BE SIMILAR FOR
SUNDAY...WITH SOME WARMING EXPECTED ON MONDAY AS CLOUD COVER SHOULD
BE SLIGHTLY LESS FOR COAST AND VALLEYS...BUT STILL MOSTLY CLOUDY
ACROSS THE MOUNTAINS. OVERNIGHT NIGHT LOWS WILL BE IN THE 70S IN
SOME ELEVATED VALLEYS...LOWER MOUNTAIN ELEVATIONS AND THE ANTELOPE
VALLEY. IT WILL BE QUITE UNCOMFORTABLE.
BY TUESDAY...THE LAST REMNANTS OF DOLORES WILL HAVE MOVED INTO
CENTRAL CALIFORNIA AS A WEAK TROUGH. HIGH TEMPS SHOULD COOL A TAD
AND MOST OF THE SUB=TROPICAL MOISTURE SHOULD BE WELL TO THE NORTH
AND EAST OF THE FORECAST AREA. THERE WILL BE A SLIGHT CHANCE FOR
LINGERING MID LEVEL MOISTURE TO SET OFF ISOLATED THUNDERSTORMS IN
THE MOUNTAINS.
THERE WILL BE A CHANCE FOR LOW CLOUDS TO REDEVELOP ALONG THE COAST
TUE NIGHT INTO WED.
.LONG TERM...BOTH THE GFS AND ECMWF SHOW A BROAD UPPER TROUGH TO THE
NORTHWEST WHILE THE UPPER RIDGE AXIS FROM TEXAS WILL CONTINUE TO
NUDGE WESTWARD INTO EXTREME SOUTHERN CALIFORNIA. THIS IS A TYPICAL
SYNOPTIC PATTERN FOR THIS TIME OF YEAR. IN THIS CASE THE THE UPPER
RIDGE WILL START TO EXPAND BY THURSDAY UNDERCUTTING THE TROUGH. THIS
WILL CAUSE HIGH TEMPS TO BUMP UP A FEW DEGREES ACROSS INLAND
AREAS...WITH CONTINUED LOW CLOUDS AND FOG ALONG THE COASTAL AREAS
AND POSSIBLY INTO A FEW COASTAL VALLEYS. HIGH TEMPS WILL BE MORE
NORMAL BY MID WEEK...WITH MUCH LESS IN THE WAY HUMIDITY.
&&
.AVIATION...19/0000Z.
AT 2100Z AT KLAX...THERE WAS NO MARINE INVERSION.
OVERALL... LOW TO MODERATE CONFIDENCE IN THE 00Z TAFS...WITH
UNCERTAINTY DUE TO SHOWERS AND TSTMS OVER THE AREA...MAINLY L.A.
AND VENTURA COUNTIES ALTHOUGH TO SOME EXTENT EASTERN SBA COUNTY WILL
SEE SOME TSRA THIS EVENING. MAINLY VFR CONDS EXPECTED FOR
CIGS/VSBY...BUT WITH A CHANCE OF LOWER VSBY IN STRONGER SHOWERS.
AFTER 12Z...HEAVIER SHOWERS ARE EXPECTED ACROSS THE AREA..WITH
MVFR/IFR CONDS POSSIBLE.
KLAX...LOW CONFIDENCE IN THE 00Z TAF DUE TO SHRA/TSRA ACTIVITY.
TIMING OF VCTS MAY CONTINUE PAST 04Z. HEAVIER -SHRA MAY LOWER VSBY
AT ANY TIME. 30% CHANCE OF MVFR OR LOWER CIGS AFTER 12Z SUNDAY.
KBUR... LOW CONFIDENCE IN THE 00Z TAF DUE TO SHRA/TSRA ACTIVITY.
TIMING OF VCTS MAY CONTINUE PAST 05Z. HEAVIER -SHRA MAY LOWER VSBY
AT ANY TIME. 30% CHANCE OF MVFR OR LOWER CIGS AFTER 12Z SUNDAY.
&&
.MARINE...19/900 PM
WINDS WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVEL THROUGH THE
WEEKEND AND INTO MONDAY. NORTHWEST WINDS WILL GRADUALLY INCREASE
BEGINNING LATE MONDAY. THERE IS MODERATE CONFIDENCE IN NORTHWEST
WINDS INCREASING TO SMALL CRAFT ADVISORY LEVELS OVER THE OUTER
WATERS FROM TUESDAY NIGHT THROUGH THURSDAY.
A SOUTHEASTERLY SWELL FROM CURRENT TROPICAL DEPRESSION DOLORES WILL
CONTINUE TO MOVE ACROSS THE COASTAL WATERS...PEAKING SUNDAY NIGHT
AND MONDAY BEFORE DIMINISHING TUESDAY. A SLIGHT CHANCE OF
THUNDERSTORMS WILL CONTINUE ACROSS THE WATERS THROUGH MONDAY.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH (SEE LAXFFALOX).
BEACH HAZARDS STATEMENT (SEE LAXCFWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).
&&
$$
PUBLIC...HALL/KAPLAN
AVIATION/MARINE...HALL/SMITH
SYNOPSIS...HALL/SUKUP
WWW.WEATHER.GOV/LOSANGELES
AREA FORECAST DISCUSSION
NWS PUEBLO CO
634 PM MDT MON JUL 20 2015
.UPDATE...
ISSUED AT 627 PM MDT MON JUL 20 2015
UPDATED TO ADJUST POPS PER LATEST RADAR AND OBS AS WELL AS
HIGH RES MODEL DATA. ROSE
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 243 PM MDT MON JUL 20 2015
CURRENTLY...A HEALTHY AMOUNT OF CLOUD COVER THROUGH MUCH OF THE DAY
HAS PUT A DAMPER ON MUCH OF THE POTENTIAL ACTIVITY FOR TODAY...AND
CONVECTION CURRENTLY OVER THE HIGHER TERRAIN WAS SLOW TO START. NO
REPORTS OF HEAVY RAINFALL AS OF YET...AS SOUNDINGS THIS MORNING
CONFIRMED THAT THE GREATER AMOUNT OF MOISTURE IS AVAILABLE IN NM.
TEMPS HAVE WARMED INTO THE UPPER 70S TO UPPER 80S ACROSS THE PLAINS
AS OF 3 PM...AND IN THE 60S AND 70S FOR THE HIGH VALLEYS. SFC WINDS
ACROSS THE PLAINS HAVE BEEN GENERALLY OUR OF THE EAST...BUT WITHIN
THE PAST COUPLE OF HOURS HAVE SHIFTED TO A MORE S-SE DIRECTION.
TONIGHT...A FLAT RIDGE OF HIGH PRESSURE OVER THE SOUTHERN U.S. WILL
STAY THAT WAY FOR ANOTHER DAY OR SO...AS A COUPLE OF UPPER
DISTURBANCES CROSS THE GREAT BASIN AND NORTHERN ROCKIES. HI RES
MODELS INCLUDING THE HRRR INDICATE THAT THE CURRENT ACTIVITY WILL
CONTINUE WELL INTO THE NIGHT...WITH SOME SPILL OVER ACROSS THE I25
CORRIDOR THIS EVENING BETWEEN 22Z AND 06Z. OTHERWISE...FEEL THAT
ACTIVITY WILL BE MAINLY TIED TO THE MTS. SO...NOT A LOT OF
IMPRESSIVE STORMS JUST YET AND THE UPPER W-SW FLOW HAS BEEN KEEPING
STORMS MOVING...CUTTING DOWN ON THE FLASH FLOOD THREAT. PRECIPITABLE
WATER AMOUNTS SOUTH OF THE STATE LINE IN NM ARE WELL OVER AN
INCH...BUT UP NORTH IN THE PUB CWA ARE CLOSER TO .6 TO .7 OF AN
INCH. OF COURSE...THE THREAT OF FLASH FLOODING FOR AREA BURN SCARS
REMAINS THIS EVE AND WILL HAVE TO BE MONITORED.
TOMORROW...THE ACTIVE PATTERN CONTINUES AS A SHORTWAVE CROSSES
WY...PROVIDING THE TRIGGER FOR A RAPID INCREASE IN CONVECTION OVER
ALL OF THE MTS AND ADJACENT PLAINS BY 15Z. AS THIS WAVE CONTINUE
EAST...THE BAND OF ENHANCED LIFT WILL CROSS THE I25 CORRIDOR AND E
PLAINS THROUGH THE AFTN HRS...AND AN ATTEMPT HAS BEEN MADE IN THE
POP GRIDS TO SHOW THIS. STRONG TO SEVERE STORMS WILL ALSO BE A
POSSIBILITY TOMORROW AFTN AS THIS WAVE CROSSES THE AREA...AS THERE
WILL BE PLENTY OF MOISTURE AND SHEAR ON TAP...AND SPC HAS PAINTED
MUCH OF THE E PLAINS IN THE MARGINAL AREA. MAX TEMPS TOMORROW MAY BE
A DEGREE OR TWO COOLER...BUT SHOULD STILL WARM INTO THE 70S AND 80S
FOR THE PLAINS...60S AND 70S FOR THE HIGH VALLEYS. MOORE
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 243 PM MDT MON JUL 20 2015
TUESDAY NIGHT...
AN AREA OF SHOWERS AND STORMS WILL LIKELY BE MOVING ACROSS THE
EASTERN PLAINS AS A DISTURBANCE OVER THE REGION CONTINUES TO MOVE
EAST. LOCALLY HEAVY RAIN WILL BE POSSIBLE AND STRONG TO MARGINALLY
SVR STORMS WILL BE POSSIBLE GIVEN THE MODEST CAPE AND SHEAR THAT
WILL BE OVER THE PLAINS.
WEDNESDAY THROUGH FRIDAY...
OVERALL IT WILL BE DRY AND WARM AS MONSOON TAP WILL BE DECREASED
AS HEIGHTS RISE ACROSS THE REGION. MAX TEMPS OVER THE PLAINS WILL
RISE BACK UP INTO THE 90S. WE WILL STILL SEE SOME ISOLD TSRA
ACROSS THE REGION...BUT OVERALL COVERAGE WILL BE LESS THAN THE
LAST FEW DAYS.
SATURDAY INTO MONDAY..
GUIDANCE INDICATES MONSOON MOISTURE WILL ONCE AGAIN BE ON THE
UPSWING AS SW FLOW CONTINUES ALOFT AND A TROUGH TO OUR WEST MOVES
TOWARDS THE REGION. TEMPS WILL COOL SLIGHTLY AND SHOWERS AND
STORMS SHOULD INCREASE DURING THE AFTERNOON AND EVENING TIME
PERIODS. /HODANISH
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 243 PM MDT MON JUL 20 2015
CONVECTION IS EXPECTED TO CONTINUE ACROSS THE HIGHER TERRAIN THIS
EVE...BUT SFC WINDS SHIFTING TO A MORE S-SE DIRECTION THIS AFTN WILL
ALLOW A FEW OF THE STORMS TO CROSS THE I25 CORRIDOR. THEREFORE...AN
ISOLATED STORM PROBABLE FOR KCOS OR KPUB...BUT MORE SO OUTFLOW
WINDS. KALS WILL HAVE A BETTER CHANCE FOR SHOWER AND STORM ACTIVITY
IN THE VCNTY THROUGH 07Z. LOOK FOR VFR CONDITIONS OVER THE NEXT 24
HRS FOR MUCH OF THE AREA...WITH MVFR TO IFR CONDITIONS AT TIMES OVER
THE MT PASSES ASSOCIATED WITH STRONGER STORMS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ROSE
SHORT TERM...MOORE
LONG TERM...HODANISH
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
336 AM MDT SUN JUL 19 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 326 AM MDT SUN JUL 19 2015
SWLY FLOW ALOFT WILL BECOME MORE WLY BY AFTN INTO THE EVENING HOURS.
QUITE A BIT OF SUBTROPICAL MOISTURE IS EMBEDDED IN THE FLOW AND WITH
INCREASING LOW LVL MOISTURE PRECIPITABLE WATER VALUES HAVE RISEN TO
AROUND AN INCH. BY EARLY AFTN A WK SFC LOW WILL DVLP SOUTH OF
DENVER WITH A CONVERGENCE ZONE SETTING UP ACROSS THE PALMER DIVIDE
ACROSS THE ECNTRL PLAINS. AT THIS TIME IT APPEARS THIS CONVERGENCE
ZONE WILL BE THE MAIN FOCUS FOR TSTMS THIS AFTN INTO THE EARLY
EVENING HOURS ACROSS NERN CO. HOWEVER EXPECT OUTFLOW BOUNDARIES FM
CONVECTION OVER THE HIGHER TERRAIN WILL TRIGGER ADDITIONAL
ACTIVITY FURTHER NORTH OF THIS BNDRY AS WELL. WITH ABUNDANT
MOISTURE THERE WILL BE SOME HEAVY RAIN HOWEVER FLOW ALOFT IS
STRONG ENOUGH SUCH THAT STORMS SHOULD MOVE RATHER QUICKLY. AS FAR
AS SVR WX THERE IS FAVORABLE SHEAR HOWEVER CIPS GUIDANCE SHOWS
RATHER LOW POTENTIAL FOR SVR BUT CANT RULE OUT AN ISOLD SVR WIND
REPORT OR TWO MAINLY OVER THE PALMER DIVIDE. AS FOR TEMPS READINGS
SHOULD BE COOLER THAN YESTERDAY WITH READINGS IN THE 80S ACROSS
THE PLAINS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 326 AM MDT SUN JUL 19 2015
MODELS HAVE A RELATIVELY WEAK UPPER RIDGE AXIS OVER COLORADO
MONDAY THROUGH TUESDAY NIGHT. THE FLOW ALOFT LOOKS TO REMAIN
SOUTHWESTERLY ALL FOUR PERIODS. THERE IS WEAK UPWARD QG MOTION
PROGGED FOR THE CWA DURING THE PERIOD. THE BOUNDARY LAYER FLOW
LOOKS TO ADHERE TO NORMAL DIURNAL PATTERNS FOR THIS TIME OF YEAR.
THERE IS PRETTY DECENT MOISTURE PROGGED FOR THE CWA. THE
PRECIPITABLE WATER VALUES ARE IN THE 0.60 TO 1.30 INCH RANGE FOR
THE FOOTHILLS AND PLAINS THROUGH THE PERIODS. BOUNDARY LAYER DEW
POINTS ARE MOSTLY IN THE 50S F FOR THE FOOTHILLS AND PLAINS...WITH
SOME LOWER 60S F FOR THE EASTERN PLAINS. FOR LATE DAY MONDAY...THE
CAPE IS NOT VERY SIGNIFICANT OVER THE CWA...AND MAINLY RELEGATED
TO THE MOUNTAINS...FOOTHILLS...AND SOUTHERN CWA. BETTER CAPE IS
PROGGED FOR LATE DAY TUESDAY FOR ALL THE CWA. WILL NEED
"SCATTERED" POPS FOR THE LATER DAY PERIODS FOR MUCH OF THE CWA
MONDAY AND TUESDAY. FOR TEMPERATURES...MONDAY`S HIGHS WILL BE
CLOSE TO TODAY`S READINGS...WITH 0-1.5 C WARMER READINGS FOR
TUESDAY. FOR THE LATER DAYS...WEDNESDAY THROUGH SATURDAY...MODELS
HAVE THE UPPER RIDGE AXIS EAST OF COLORADO THROUGH THE
PERIOD...WITH WEST-SOUTHWESTERLY FLOW ALOFT. THE AIRMASS IS
PROGGED TO BE DRIER AND A BIT WARMER THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 326 AM MDT SUN JUL 19 2015
A WK DENVER CYCLONE IS WEST OF DIA EARLY THIS MORNING AND WITH CLEAR
SKIES WILL HAVE TO BE ON THE LOOKOUT FOR STRATUS/FOG DEVELOPMENT IN
THE NEXT FEW HOURS. SATELLITE DATA ALREADY SHOWS A SMALL PATCH OF
STRATUS JUST SOUTH OF THE AIRPORT AT 09Z. HRRR HAD BEEN RATHER
CONSISTENT IN SHOWING SOME POSSIBLE DENSE FOG AFFECTING DIA BUT
LATEST RUN NOW KEEP IT MAINLY TO THE EAST AND NORTHEAST. FOR NOW
WILL KEEP IN A TEMPO GROUP DUE TO UNCERTAINTY.
FOR THIS AFTN A WK CYCLONE IS FCST TO BE SOUTH OF THE AIRPORT WITH A
CONVERGENCE ZN TO THE EAST AND SOUTHEAST. IF THIS IS THE CASE THEN
BEST CHC OF STORMS MAY STAY TO THE E AND SE HOWEVER OUTFLOW
BOUNDARIES COULD TRIGGER ADDITIONAL STORMS FURTHER NORTH SO WILL
KEEP IN A TEMPO GROUP FM 21Z THRU 01Z. FOR THIS EVENING WINDS WILL
BECOME MORE SSW AND SHOULD STAY THAT WAY OVERNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM...RJK
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1119 PM MDT SAT JUL 18 2015
.UPDATE...
ISSUED AT 626 PM MDT SAT JUL 18 2015
UPDATED GRIDS MAINLY FOR POPS TONIGHT AND TOMORROW MORNING.
BASED ON OBS AND LATEST HIGH RES MODEL RUNS...WILL SEE ANOTHER
ROUND OF SHOWERS AND STORMS THIS EVENING...ESPECIALLY IN THE 04Z
TO 10Z TIME RANGE. LOOKS LIKE BEST COVERAGE WILL BE OVER THE
WESTERN ZONES AND AREAS NORTH OF HGWY 160...ESPECIALLY THE NRN
I-25 CORRIDOR...SO HAVE INCREASED POPS TO CHANCE RANGE OVER EL
PASO COUNTY. ACTIVITY SHOULD DIE OUT EARLY SUN MORNING...SETTING
THE STAGE FOR A DAY OF ACTIVE WX ON SUNDAY. ROSE
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 310 PM MDT SAT JUL 18 2015
...A WET DAY LIKELY TOMORROW AFTERNOON...
CURRENTLY...
TWO DISTURBANCES OF NOTE...THE FIRST WAS MOVING OVER THE CENTRAL
PART OF COLORADO. A BROAD LINE OF SHOWERS AND THUNDERSTORMS EXTENDED
NNE-SSW WITH THIS DISTURBANCE AND WAS LOCATED OVER THE CENTRAL PART
OF THE STATE. THE 2ND DISTURBANCE WAS OVER SOUTHERN CALIF/LAS VEGAS
REGION. QUITE A BIT OF CONVECTION WAS ASSOCIATED WITH THIS 2ND
DISTURBANCE.
REST OF TODAY AND TONIGHT...
COULD SEE 2 MCS`S DEVELOP LATE THIS AFTERNOON/EVENING. THE FIRST
WILL BE OVER NE CO AND THE 2ND COULD BE FARTHER SOUTH OVER SE
COLORADO. ALTHOUGH BEST FORCING IS LIFTING OFF NORTHEAST TOWARDS NE
CO...THE BETTER INSTABILITY IS LOCATED OVER SE COLO. NEW 18Z NAM IS
CATCHING ON TO THIS POSSIBILITY. HRRR ALSO SHOWS MODEST TO STRONGER
CONVECTION EXTENDING N-S ALONG THE HI PLAINS LATER THIS EVENING. 12
GFS WAS NOT SHOWING MUCH OF ANYTHING OVER THE HI PLAINS ADJ TO COLO
LATER THIS EVENING. ATTM...I HAVE HI ISOLD POPS ALONG MOST OF THE I-
25 CORRIDOR BECOMING SCTD POPS OVER THE FAR EASTERN PLAINS LATER
THIS EVENING.
PRECIP WILL LIKELY LINGER INTO THE EARLY MORNING HOURS ALL AREAS
GIVEN THE MOISTURE PLUME OVER THE REGION...AND HAVE KEPT LOW POPS
MOST AREAS.
WE COULD STILL SEE A FEW MARGINAL SEVERE STORMS TODAY ACROSS THE
REGION...ESPECIALLY EL PASO AND THE FAR E PLAINS.
TOMORROW...
QUITE A BIT OF CLOUDS WILL LIKELY BE OVER THE REGION TOMORROW
MORNING. GUIDANCE IS NOT SHOWING ANY LOW CIGS GIVEN THE WIND
FLOW...BUT IF THE MCS`S BECOME QUITE STRONG THEN SOME LOW STRATUS
COULD DEVELOP OVER THE REGION EARLY TOMORROW.
TOMORROW THE GUIDANCE IS RATHER HIGH WITH POPS MOVING OVER THE
REGION...AND GIVEN THE WELL DEFINED DISTURBANCE OVER THE CALIF
REGION...THESE VALUES ARE WARRANTED. PRECIP SHOULD DEVELOP RATHER
EARLY IN THE MTNS AND MOVE EASTWARD W/TIME. I PAINTED HIGH
SCTD/LIKELY POPS OVER THE MTNS...ESPECIALLY THE CONTDVD. FLASH
FLOODING OVER THE HI TRRN COULD OCCUR...BUT WILL DEFER TO LATER
SHIFTS TO ISSUE ANY HILITES.
FOR THE PLAINS...ALTHOUGH ALL GUIDANCE BLOWS UP CONVECTION OVER THE
HI PLAINS TOMORROW...THEY ARE HAVING A PROBLEM WITH LOCATION. EC HAS
THE MCS BLOWING UP RELATIVELY EARLY OVER EAST CENTRAL CO...THE NAM
APPEARS TO ONCE AGAIN DEVELOP A COUPLE OF MCS`S OVER THE HI PLAINS
WHILE THE GFS IS OVER NE COLORADO. WPC HAS THE BULLSEYE OVER EC
COLO. FOR NOW PAINTED SCTD POPS OVER THE PLAINS BY LATE AFTERNOON
TOMORROW. WE WILL ALSO LIKELY SEE SOME HEAVY RAIN LATE TOMORROW
AFTERNOON OVER THE LOWER ELEVATIONS AND HAVE PAINTED MDT RAIN IN THE
NDFD.
STRONG TO MARGINALLY SVR STORMS WILL ONCE AGAIN BE POSSIBLE TOMORROW
AFTERNOON ACROSS THE REGION. /HODANISH
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 310 PM MDT SAT JUL 18 2015
LITTLE CHANGE TO THE EXPECTED WEATHER TREND THROUGH THE
EXTENDED...WITH A SLIGHTLY SLOWER PROGRESSION OF THE REMNANTS OF
TROPICAL STORM DOLORES.
SUNDAY NIGHT THROUGH TUESDAY...THE FLAT UPPER RIDGE WILL REMAIN
LOCKED OVER THE SOUTHERN U.S. THROUGH THE EXTENDED PERIOD...BUT A
COUPLE OF DISTURBANCES WILL KEEP THE PATTERN ACTIVE THROUGH TUE.
FIRST...AN UPPER SHORTWAVE WILL CROSS MT AND WY SUN EVE...PUSHING A
FRONT DOWN ACROSS THE PALMER DVD AND SOUTHEASTERN PLAINS ON MON. THE
SECOND FEATURE WILL BE THE REMNANTS OF DOLORES...WHICH IS FORECAST
TO TRACK EAST ACROSS THE GREAT BASIN ON MON AND COLORADO ON TUE.
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED EACH AFTN AND EVE
ACROSS ALL OF THE FORECAST AREA...WITH LINGERING ISOLATED ACTIVITY
INTO THE NIGHT. ACROSS THE MTS AND IMMEDIATELY ADJACENT
PLAINS...CONVECTION WILL BE LIKELY THROUGH THE AFTN AND EARLY EVE
HOURS. THIS INCREASED ACTIVITY AND CLOUD COVER IS EXPECTED TO KEEP
MAX TEMPS BELOW NORMAL...WITH 80S ACROSS THE PLAINS AND 70S FOR THE
HIGH VALLEYS SUNDAY THROUGH TUESDAY. THERE IS THE POTENTIAL FOR
HEAVIER RAINFALL EACH DAY THROUGH THE LATE AFTN AND EARLY EVE
HOURS...SO THERE WILL BE THE HEIGHTENED THREAT OF FLASH FLOODING FOR
AREA BURN SCARS.
WEDNESDAY THROUGH SATURDAY...A MORE WEST TO SOUTHWEST FLOW ALOFT
THEN DEVELOPS ACROSS THE 4 CORNERS STARTING WED AND LASTING INTO THE
WEEKEND...AS UPPER HIGH PRESSURE REACHES BACK ACROSS NM AND AZ...AND
ANOTHER UPPER LOW PRES TROUGH STARTS TO DIG DOWN OVER THE PAC NW.
WED LOOKS TO BE A TRANSITIONAL DAY FOR THE WEATHER PATTERN...SO PCPN
CHANCES WILL BE ON THE DECREASE WED AS TEMPS START TO GRADUALLY
WARM. MODELS INDICATE THE AVAILABLE MOISTURE TAP WILL BE SUPPRESSED
TO THE SOUTH OF CO THROUGH THIS PERIOD...WITH JUST ISOLATED DIURNAL
MOUNTAIN CONVECTION FORECAST. TEMPS WILL WARM BACK UP TO NEAR
SEASONAL NORMS...WITH MAX READINGS IN THE 90S FOR THE PLAINS AND 80S
FOR THE HIGH VALLEYS. MOORE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1114 PM MDT SAT JUL 18 2015
THERE IS STILL A SLIGHT CHANCE OF A SHWR OR TS OVERNIGHT...BUT THE
PROBABILITY IS TOO LOW TO MENTION IN THE 06Z TAF. MAIN CONCERN
WILL BE MORE WIDESPREAD STORMS DEVELOPING EARLY SUN
AFTERNOON...FIRST OVER THE MTS...THEN SPREADING TO THE CENTRAL SAN
LUIS VALLEY AND I-25 CORRIDOR BY 20-21Z. THIS COULD RESULT IN A
BRIEF PERIOD OF TSRA FOR THE TAF SITES...AND THE POSSIBILITY OF
GUSTY WINDS AND SMALL HAIL. BRIEF MVFR TO IFR CIGS AND/OR VIS
WILL BE POSSIBLE AS STORMS MOVE THROUGH. STORMS WILL THEN MOVE OUT
OVER THE ERN PLAINS AND EVENTUALLY ON TO KS SUN EVENING...WITH
TS CHANCES DIMINISHING AFTER SUNSET. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ROSE
SHORT TERM...HODANISH
LONG TERM...MOORE
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS ALBANY NY
1025 PM EDT MON JUL 20 2015
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE REGION ON TUESDAY...BRINGING A
CHANCE FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD IN
FROM CANADA INTO THE GREAT LAKES WEDNESDAY...USHERING IN A COOLER
AND DRIER AIR MASS INTO THE REGION FOR MID TO LATE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 1025 PM...MAINLY JUST HIGH CLOUDS ACROSS THE ALBANY
FORECAST AREA AT THIS TIME. SOME LOWER CLOUDS ACROSS THE EXTREME
SOUTH AS COLD FRONT/DEWPOINT BOUNDARY APPEARS TO HAVE HUNG UP JUST
SOUTH OF POUGHKEEPSIE. THERE WERE A FEW SHOWERS VCNTY OF
POUGHKEEPSIE AN HOUR AGO...BUT RADAR SHOWS THEY HAVE DISSIPATED.
SHOWERS ASSOCIATED WITH COLD FRONT TO NORTHWEST ARE STILL NORTH
AND WEST OF TORONTO. LATEST HRRR HAS NOTHING BUT A FEW SPRINKLES
THROUGH 12Z SO NOT EXPECTING MUCH CHANGE THROUGH THE OVERNIGHT.
THIS CDFNT WILL REACH LK ERI-ST LAWRENCE VLY BY MORNING...FOLLOWED
BY A 500 HPA SHORT WV...AND CROSS THE FCA DURING THE DAY TUES. TD
CLOSE TO 60 AND ONLY 400-800 J/KG CAPE...BEST LI -4 TO -6 WITH
FOCUS ALONG W PERIPHERY OF FCA...ONLY SCT NON SEVERE TSTMS AND
-SHRA ARE EXPECTED. SPC HAS AREA IN GEN TSTMS..NO SVR THREAT.
OTRW TUES WILL BE A WARM DAY WITH HIGHS IN THE 80S AND A FEW NR
90 IN THE SOUTH...AS WELL AS SCT- BKN CU AHEAD OF THE
CDFNT...CLOUDS WITH ITS PASSAGE AND CLEARING IN ITS WAKE.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
TUES EVNG THE CDFNT WILL PUSH S OF FCA AND 500HPA TROF MOVES
ACROSS NY/NEW ENG OVRNT. SCT -SHRA/TSTMS WILL END IN THE EVNG
SE...OTHERWISE PERIOD WILL BE DOMINATED BY DEEPENING 500 HPA CUT
OFF LOW OVER QB...WHICH MOVES SE TO THE MARITIMES IN AN ALMOST
FALL LIKE SCENARIO...AS SHORT WVS ROTATE IN THE FLOW ARND IT.
SFC HIGH PRESSURE WILL BUILD INTO THE GRTLKS...WITH CAA INTO FCA
AND A NOTICABLE NW WIND GRADIENT. ACROSS THE S TIER THE RESULT
WILL BE MS AND DRY CONDS..WHILE IN THE N BKN DIURNALLY DRIVEN CU
WILL BE THE RULE...ALONG WITH ISOLD TO SCT --SHRA PARTICULARLY
OVER THE HIR TRRN DURING THIS PERIOD. IN BETWEEN WILL BE PC AND
ACROSS THE ENTIRE RGN TEMPS WILL BE ARND 5 DEG BLO NORMAL.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE LONG TERM PERIOD WILL BE CHARACTERIZED BY MAINLY TRANQUIL
WEATHER CONDITIONS AS THE REGION REMAINS IN A NORTHWEST FLOW
REGIME.
AT THE START OF THE LONG TERM PERIOD...THE REGION WILL BE SITUATED
ON THE WESTWARD SIDE OF AN UPPER-LEVEL TROUGH...WITH A RESULTING
NORTHWEST FLOW REGIME. EXCEPT FOR A FEW ISOLATED SHOWERS ACROSS
SOUTHERN VERMONT...MUCH OF THE REGION WILL BE DRY FRIDAY WITH A FALL-
LIKE AIRMASS IN PLACE.
THIS FALL-LIKE AIRMASS...SLIGHTLY BELOW TEMPERATURES AND COMFORTABLE
HUMIDITY LEVELS...WILL CONTINUE INTO SATURDAY AS AN AREA OF HIGH
PRESSURE RIDGES ACROSS THE REGION. SATURDAY LOOKS TO BE THE NICEST
DAY OF THE LONG TERM PERIOD WITH DRY WEATHER AND PARTLY CLOUDY SKIES.
DRY WEATHER LOOKS TO CONTINUE INTO SATURDAY NIGHT...WHILE AN UPPER-
LEVEL SHORTWAVE TROUGH APPROACHES FROM THE GREAT LAKES REGION. LONG
RANGE GUIDANCE IS HAVING SOME DIFFICULTY RESOLVING THIS SHORTWAVE
WITH IT BEING SO FAR OUT IN TIME...SO HAVE GONE WITH SLIGHT CHANCE
AND CHANCE POPS IN THE FORECAST FOR SUNDAY AND INTO MONDAY.
HIGH TEMPERATURES THROUGHOUT THE LONG TERM PERIOD WILL GENERALLY
RANGE FROM THE LOW 70S TO UPPER 70S...WITH SOME HIGHER TERRAIN
LOCATIONS IN SOUTHERN VERMONT AND THE ADIRONDACKS IN THE UPPER
60S...WITH SOME HIGHS NEAR 80 IN THE HUDSON VALLEY. LOW TEMPERATURES
THROUGHOUT THE LONG TERM PERIOD WILL GENERALLY RANGE FROM THE UPPER
50S TO LOW 60S...EXCEPT FOR THE LOW 50S TO UPPER 50S FRIDAY NIGHT.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
MAINLY VFR CONDITIONS THROUGH THE 24 HOUR TAF CYCLE WITH TWO
PERIODS WHERE MVFR CONDITIONS MAY DEVELOP FOR A SHORT TIME. AFTER
ABOUT 09Z TONIGHT...SOME LOWER VISIBILITIES AND SCATTERED CLOUDS
BELOW 1000 FEET MAY DEVELOP AT KGFL AND KPSF AND HAVE PLACED VSBYS
AT 3SM IN THEIR RESPECTIVE TAFS. LATER TUESDAY AFTERNOON...
SHOWERS AND THUNDERSTORMS ARE EXPECTED AHEAD OF A COLD FRONT. FOR
NOW JUST VCSH IN TAFS BUT WE WILL MONITOR FOR IFR CONDITIONS AND
LIGHTNING.
WEST TO NORTHWEST WINDS AT AROUND 10 KTS BECOMING LIGHT AND
VARIABLE TO NEAR CALM TONIGHT. WINDS WILL BECOME SOUTH TO
SOUTHWEST AT 5 TO 10 KTS TUESDAY.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...FG...TSRA.
WEDNESDAY THROUGH SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
HIGH PRESSURE WILL BUILD ACROSS THE REGION THIS AFTERNOON AND SLIDE
OFFSHORE TONIGHT. A STRONGER COLD FRONT WILL CROSS THE REGION ON
TUESDAY...BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS. HIGH
PRESSURE WILL BUILD FROM CANADA INTO THE GREAT LAKES
WEDNESDAY...USHERING IN A COOLER AND DRIER AIR MASS INTO THE
REGION FOR MID WEEK TO LATE WEEK.
RELATIVE HUMIDITY VALUES WILL INCREASE TO MAXIMUM VALUES OF 80 TO
100 PERCENT TONIGHT AND TUESDAY NIGHT. MINIMUM VALUES TUESDAY
AFTERNOON WILL BE 35 TO 65 PERCENT...AND 35 TO 55 PERCENT
WEDNESDAY AFTERNOON.
WINDS WILL BE LIGHT TONIGHT...AND BECOME SOUTHWEST AND INCREASE
TO AROUND 10 TO 15 MPH TUESDAY. TUESDAY NIGHT THEY WILL BECOME
WEST AROUND 5 MPH AND INCREASE TO 10 TO 15 MPH WEDNESDAY.
&&
.HYDROLOGY...
MAINLY DRY CONDITIONS ARE EXPECTED THROUGH THE WEEK WITH THE
EXCEPTION OF SCATTERED SHOWERS AND THUNDERSTORMS TUESDAY
ASSOCIATED WITH A COLD FRONT. SOME LOCALLY HEAVY RAINFALL WILL BE
POSSIBLE IN ANY STRONGER STORMS...WITH PONDING OF WATER IN URBAN
AND POOR DRAINAGE LOCATIONS.
MAINLY DRY WEATHER IS THEN EXPECTED FROM WEDNESDAY THROUGH FRIDAY
EXCEPT FOR A FEW LIGHT SHOWERS ACROSS PORTIONS OF THE ADIRONDACKS
EACH DAY.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SND/SNYDER
NEAR TERM...SND/SNYDER
SHORT TERM...SNYDER
LONG TERM...IRL
AVIATION...SND/11
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER/JPV
AREA FORECAST DISCUSSION
NWS TAUNTON MA
655 PM EDT SUN JUL 19 2015
.SYNOPSIS...
SEVERE THUNDERSTORMS WILL MOVE THROUGH PARTS OF SOUTHERN NEW
ENGLAND TONIGHT...BRINGING THE POTENTIAL FOR DAMAGING WINDS AND
LOCALIZED FLOODING. A COLD FRONT WILL DROP THROUGH NEW ENGLAND
MONDAY AND MAY TRIGGER SCATTERED THUNDERSTORMS NEAR THE SOUTH
COAST. A COLD FRONT SWEEPS THROUGH THE REGION TUESDAY. HIGH
PRESSURE BUILDS OVER THE REGION FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
655 PM UPDATE...
*** THUNDERSTORMS ENTERING SOUTHERN NEW ENGLAND ***
AFTER REVIEWING RADAR TRENDS...ISSUED A FLASH FLOOD WATCH UNTIL
10 PM FOR PARTS OF WESTERN AND N CENTRAL MA. COMPLEX OF STORMS
COMING OUT OF BERKSHIRES HAS POTENTIAL TO PRODUCE OVER 2 INCHES OF
RAIN IN A SHORT TIME. MAY NEED TO EXTEND THIS WATCH FARTHER E IN A
BIT.
FIRST BATCH OF STORMS ENTERING BERKSHIRES BEING MONITORED FOR
POTENTIALLY DAMAGING WINDS AND LOCALIZED FLOODING. THIS SMALL
COMPLEX OF STORMS WILL AFFECT AREAS NORTH OF MASS PIKE EARLY
TONIGHT AND WILL REMAIN IN FAVORABLE ENVIRONMENT FOR STORM
MAINTENANCE WHICH FEATURES HIGH CAPE...DECENT SHEAR AND GOOD MID
LEVEL LAPSE RATES. MEANWHILE...MORE STORMS WERE DEVELOPING IN SE
NY AND MAY MOVE ACROSS AREAS SOUTH OF MASS PIKE LATER THIS
EVENING.
21Z HRRR SHOWS THIS EVOLUTION NICELY BUT SEEMS TO ERRONEOUSLY
WEAKEN ACTIVITY AS IT HEADS E. MAIN TIME FRAME FOR SEVERE STORMS
IS THROUGH 11 PM PER WW 442...BUT MAY PERSIST LONGER DEPENDING ON
HOW AIRMASS RECOVERS BEHIND THIS INITIAL ACTIVITY GIVEN MODEL
FORECASTS OF AMPLE INSTABILITY...SHEAR AND LAPSE RATES OVERNIGHT.
LEFTOVER BOUNDARIES COULD COME INTO PLAY.
MAIN HAZARDS ARE WIND DAMAGE AND EVEN LARGE HAIL DESPITE TROPICAL
AIRMASS IN PLACE. STRONG SHEAR AND FAT CAPE PROFILE IS CERTAINLY
HELPING IN THAT REGARD. STILL NEED TO WATCH FOR ISOLATED TORNADOES
AS ENVIRONMENT REMAINS FAVORABLE. ALREADY SEEING ONE STORM IN E NY
WHICH IS A RIGHT MOVER WITH STRONG ROTATION AND IS UNDER A TORNADO
WARNING.
ALSO KEEPING AN EYE ON AREAS OF FOG AND LOW CLOUDS AROUND
NANTUCKET WHICH WERE SPREADING INLAND. SHOULD REACH AT LEAST TO
CAPE COD CANAL AND S COAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
FRONT DROPS TOWARD S COAST MON WHICH IS WHERE WE WILL HAVE CHANCE
POPS FOR AFTERNOON STORMS. MODELS SHOW FAIRLY DECENT CAPE AND
SHEAR BUT IT ALL COMES DOWN TO TIMING. STILL LOOKS LIKE A HOT DAY
BUT A LITTLE LESS HUMID THAN TODAY WITH HIGHS IN 80S.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE... ZONAL FLOW AT THE START OF THE WEEK EVOLVES
MIDWEEK AS PART OF HUDSON BAY LOW DIVES FARTHER SOUTHEAST AND
CARVES OUT A TROUGH OVER THE NORTHEAST USA. CYCLONIC FLOW LINGERS
OVER NEW ENGLAND THROUGH AT LEAST FRIDAY. A SHORTWAVE RIDGE BUILDS
IN OVER THE WEEKEND. ABOVE NORMAL HEIGHTS AT THE START OF THE WEEK
ARE SUPPRESSED BY THE TROUGH TO 100 METERS BELOW NORMAL MIDWEEK.
HEIGHTS RETURN TO NEAR NORMAL BY NEXT SUNDAY.
THE VARIOUS LONG RANGE MODEL GUIDANCE ARE IN AGREEMENT THROUGH
THE PERIOD. WE FAVOR THIS MODEL BLEND FOR THIS FORECAST.
THE DAILIES...
MONDAY NIGHT... COLD FRONT ALONG THE SOUTH COAST MOVES OFFSHORE. ANY
LINGERING SHOWERS/TSTMS SHOULD MOVE OFF AT THAT TIME. OTHERWISE FAIR
SKIES AND LIGHT WINDS THROUGH THE NIGHT...WHICH WILL ALLOW PATCHES
OF FOG TO FORM LATE AT NIGHT.
TUESDAY... SHORTWAVE APPROACHES FROM THE GREAT LAKES WHILE DRIVING A
SECOND COLD FRONT EAST INTO NEW ENGLAND. THE SUPPORTING 90-KNOT JET
APPROACHES WITH THE LEFT EXIT REGION OF THE JET IN PLACE OVERHEAD
DURING THE DAY. DAYTIME HEATING WILL SUPPORT MIXING TO 800 MB. TEMPS
AT 850 MB WILL BE AROUND 18C...MIXING FROM 800 MB YIELDS SIMILAR
RESULTS. THIS WOULD SUPPORT MAX TEMPS NEAR 90. GUIDANCE IS
SEVERAL DEGREES COOLER...SO WILL BUMP THOSE VALUES UP 2-3F TO
BRING MAX SFC VALUES IN THE UPPER 80S INLAND. STABILITY PARAMETERS
ARE FAVORABLE FOR CONVECTION WITH SBCAPE AROUND 1000/SLI AROUND
ZERO/TOTALS 45-49. THIS WILL BRING CLOUDS AND SCATTERED CONVECTION
TO THE REGION...WE WILL HAVE CHANCE POPS TUESDAY AFTERNOON WITH
THE FRONTAL PASSAGE.
WEDNESDAY THROUGH FRIDAY... UPPER TROUGH HANGS OVER THE NORTHEAST
WITH COOLER TEMPS AND MOISTURE POOL ALOFT CREATING A MORE UNSTABLE
AIRMASS WITH DAYTIME HEATING CAUSING DIURNAL CLOUDS AND POSSIBLY A
FEW LIGHT SHOWERS. SEVERAL SHORTWAVES MOVE THROUGH THE FLOW DURING
THIS PERIOD ADDING TO THE CHANCE OF CLOUDS AND SHOWERS. BEST CHANCE
FOR THIS WILL BE IN NORTHERN MASSACHUSETTS.
SATURDAY AND SUNDAY... LONGWAVE AND SHORTWAVE CONTOUR FIELDS SHOW
HIGH PRESSURE BUILDING SURFACE AND ALOFT. THIS WOULD SUGGEST FAIR
DRY WEATHER WITH TEMPERATURES NEAR NORMAL. THE GFS AND ECMWF DO
SHOW A SHORTWAVE SLIPPING THROUGH ON SUNDAY EVEN AS THE HEIGHTS
TREND HIGHER. THIS WOULD SUGGEST A CHANCE OF A FEW SHOWERS. WE WILL
MENTION A CHANCE OF A THUNDERSTORM IN WESTERN MASS SUNDAY BUT KEEP
THE REST OF THE AREA DRY.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE.
IFR CIGS/VSBYS SPREAD BACK TOWARD CAPE COD CANAL THIS EVENING.
VFR ELSEWHERE THROUGH EARLY TONIGHT WITH AREAS MVFR/IFR IN
SHOWERS/TSTMS...WHICH WILL BE MORE NUMEROUS ACROSS WESTERN AND N
CENTRAL MA BUT ALSO ACROSS N CT. POTENTIAL FOR 50KT GUSTS AND
TORRENTIAL RAINFALL IN STRONGER STORMS.
SLOW IMPROVEMENT TO VFR 12Z-15Z MON NEAR S COAST...CAPE COD AND
ISLANDS. SCATTERED TSTMS POSSIBLE IN THESE AREAS 18Z-23Z. VFR
ELSEWHERE.
KBOS TAF...MODERATE CONFIDENCE. MAIN TIME FRAME FOR STORMS IS 01
TO 04Z. POTENTIAL FOR 40-50KT GUSTS AND TORRENTIAL RAINFALL.
KBDL TAF...MODERATE CONFIDENCE. MAIN TIME FRAME IS 02Z TO 05Z.
POTENTIAL FOR 40-50KT GUSTS AND TORRENTIAL RAINFALL.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...MODERATE CONFIDENCE.
MONDAY NIGHT...VFR NORTH AND TRENDING VFR SOUTH. PATCHY IFR LATE IN
FOG.
TUESDAY... VFR MOST OF THE DAY. SOME SCATTERED MVFR CIGS/VSBYS IN
SHOWERS/TSTMS ALONG AN AFTERNOON/EVENING COLD FRONT.
WEDNESDAY-THURSDAY...
VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
*** POTENTIAL FOR STRONG OR SEVERE STORMS TOWARD EVENING ***
HIGH CONFIDENCE IN WINDS AND SEAS BELOW SCA THROUGH MON. MAIN
CONCERN IS POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS TOWARD
EVENING...WHICH MAY PRODUCE STRONG WIND GUSTS...TORRENTIAL
RAINFALL WITH POOR VISIBILITY AND DANGEROUS LIGHTNING. HIGHEST
RISK FOR THESE STORMS IS ON WATERS AROUND CAPE ANN...BUT IS ALSO
POSSIBLE ELSEWHERE.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...MODERATE TO HIGH CONFIDENCE.
MONDAY NIGHT...LINGERING SHOWERS/TSTMS ALONG THE SOUTHERN WATERS IN
THE EVENING...DIMINISHING OVERNIGHT. AREAS OF POOR VSBYS IN FOG
TOWARD MORNING. WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT
THRESHOLDS.
TUESDAY...A COLD FRONT SWINGS ACROSS THE WATERS DURING THE LATE
AFTERNOON/EVENING WITH SCATTERED SHOWERS/TSTMS. WINDS BELOW 25
KNOTS/SEAS BELOW 5 FEET.
WEDNESDAY-THURSDAY...WINDS AND SEAS REMAIN BELOW SMALL CRAFT
THRESHOLDS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...FLASH FLOOD WATCH UNTIL 10 PM EDT THIS EVENING FOR MAZ002>004-
008-010-026.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WTB/JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...WTB
AVIATION...WTB/JWD
MARINE...WTB/JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
642 PM EDT SUN JUL 19 2015
.SYNOPSIS...
SEVERE THUNDERSTORMS WILL MOVE THROUGH PARTS OF SOUTHERN NEW
ENGLAND TONIGHT...BRINGING THE POTENTIAL FOR DAMAGING WINDS AND
LOCALIZED FLOODING. A COLD FRONT WILL DROP THROUGH NEW ENGLAND
MONDAY AND MAY TRIGGER SCATTERED THUNDERSTORMS NEAR THE SOUTH
COAST. A COLD FRONT SWEEPS THROUGH THE REGION TUESDAY. HIGH
PRESSURE BUILDS OVER THE REGION FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
645 PM UPDATE...
*** THUNDERSTORMS ENTERING SOUTHERN NEW ENGLAND ***
FIRST BATCH OF STORMS ENTERING BERKSHIRES BEING MONITORED FOR
POTENTIALLY DAMAGING WINDS AND LOCALIZED FLOODING. THIS SMALL
COMPLEX OF STORMS WILL AFFECT AREAS NORTH OF MASS PIKE EARLY
TONIGHT AND WILL REMAIN IN FAVORABLE ENVIRONMENT FOR STORM
MAINTENANCE WHICH FEATURES HIGH CAPE...DECENT SHEAR AND GOOD MID
LEVEL LAPSE RATES. MEANWHILE...MORE STORMS WERE DEVELOPING IN SE
NY AND MAY MOVE ACROSS AREAS SOUTH OF MASS PIKE LATER THIS
EVENING.
21Z HRRR SHOWS THIS EVOLUTION NICELY BUT SEEMS TO ERRONEOUSLY
WEAKEN ACTIVITY AS IT HEADS E. MAIN TIME FRAME FOR SEVERE STORMS
IS THROUGH 11 PM PER WW 442...BUT MAY PERSIST LONGER DEPENDING ON
HOW AIRMASS RECOVERS BEHIND THIS INITIAL ACTIVITY GIVEN MODEL
FORECASTS OF AMPLE INSTABILITY...SHEAR AND LAPSE RATES OVERNIGHT.
LEFTOVER BOUNDARIES COULD COME INTO PLAY.
MAIN HAZARDS ARE WIND DAMAGE AND EVEN LARGE HAIL DESPITE TROPICAL
AIRMASS IN PLACE. STRONG SHEAR AND FAT CAPE PROFILE IS CERTAINLY
HELPING IN THAT REGARD. STILL NEED TO WATCH FOR ISOLATED TORNADOES
AS ENVIRONMENT REMAINS FAVORABLE. ALREADY SEEING ONE STORM IN E NY
WHICH IS A RIGHT MOVER WITH STRONG ROTATION AND IS UNDER A TORNADO
WARNING.
ALSO KEEPING AN EYE ON AREAS OF FOG AND LOW CLOUDS AROUND
NANTUCKET WHICH WERE SPREADING INLAND. SHOULD REACH AT LEAST TO
CAPE COD CANAL AND S COAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
FRONT DROPS TOWARD S COAST MON WHICH IS WHERE WE WILL HAVE CHANCE
POPS FOR AFTERNOON STORMS. MODELS SHOW FAIRLY DECENT CAPE AND
SHEAR BUT IT ALL COMES DOWN TO TIMING. STILL LOOKS LIKE A HOT DAY
BUT A LITTLE LESS HUMID THAN TODAY WITH HIGHS IN 80S.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE... ZONAL FLOW AT THE START OF THE WEEK EVOLVES
MIDWEEK AS PART OF HUDSON BAY LOW DIVES FARTHER SOUTHEAST AND
CARVES OUT A TROUGH OVER THE NORTHEAST USA. CYCLONIC FLOW LINGERS
OVER NEW ENGLAND THROUGH AT LEAST FRIDAY. A SHORTWAVE RIDGE BUILDS
IN OVER THE WEEKEND. ABOVE NORMAL HEIGHTS AT THE START OF THE WEEK
ARE SUPPRESSED BY THE TROUGH TO 100 METERS BELOW NORMAL MIDWEEK.
HEIGHTS RETURN TO NEAR NORMAL BY NEXT SUNDAY.
THE VARIOUS LONG RANGE MODEL GUIDANCE ARE IN AGREEMENT THROUGH
THE PERIOD. WE FAVOR THIS MODEL BLEND FOR THIS FORECAST.
THE DAILIES...
MONDAY NIGHT... COLD FRONT ALONG THE SOUTH COAST MOVES OFFSHORE. ANY
LINGERING SHOWERS/TSTMS SHOULD MOVE OFF AT THAT TIME. OTHERWISE FAIR
SKIES AND LIGHT WINDS THROUGH THE NIGHT...WHICH WILL ALLOW PATCHES
OF FOG TO FORM LATE AT NIGHT.
TUESDAY... SHORTWAVE APPROACHES FROM THE GREAT LAKES WHILE DRIVING A
SECOND COLD FRONT EAST INTO NEW ENGLAND. THE SUPPORTING 90-KNOT JET
APPROACHES WITH THE LEFT EXIT REGION OF THE JET IN PLACE OVERHEAD
DURING THE DAY. DAYTIME HEATING WILL SUPPORT MIXING TO 800 MB. TEMPS
AT 850 MB WILL BE AROUND 18C...MIXING FROM 800 MB YIELDS SIMILAR
RESULTS. THIS WOULD SUPPORT MAX TEMPS NEAR 90. GUIDANCE IS
SEVERAL DEGREES COOLER...SO WILL BUMP THOSE VALUES UP 2-3F TO
BRING MAX SFC VALUES IN THE UPPER 80S INLAND. STABILITY PARAMETERS
ARE FAVORABLE FOR CONVECTION WITH SBCAPE AROUND 1000/SLI AROUND
ZERO/TOTALS 45-49. THIS WILL BRING CLOUDS AND SCATTERED CONVECTION
TO THE REGION...WE WILL HAVE CHANCE POPS TUESDAY AFTERNOON WITH
THE FRONTAL PASSAGE.
WEDNESDAY THROUGH FRIDAY... UPPER TROUGH HANGS OVER THE NORTHEAST
WITH COOLER TEMPS AND MOISTURE POOL ALOFT CREATING A MORE UNSTABLE
AIRMASS WITH DAYTIME HEATING CAUSING DIURNAL CLOUDS AND POSSIBLY A
FEW LIGHT SHOWERS. SEVERAL SHORTWAVES MOVE THROUGH THE FLOW DURING
THIS PERIOD ADDING TO THE CHANCE OF CLOUDS AND SHOWERS. BEST CHANCE
FOR THIS WILL BE IN NORTHERN MASSACHUSETTS.
SATURDAY AND SUNDAY... LONGWAVE AND SHORTWAVE CONTOUR FIELDS SHOW
HIGH PRESSURE BUILDING SURFACE AND ALOFT. THIS WOULD SUGGEST FAIR
DRY WEATHER WITH TEMPERATURES NEAR NORMAL. THE GFS AND ECMWF DO
SHOW A SHORTWAVE SLIPPING THROUGH ON SUNDAY EVEN AS THE HEIGHTS
TREND HIGHER. THIS WOULD SUGGEST A CHANCE OF A FEW SHOWERS. WE WILL
MENTION A CHANCE OF A THUNDERSTORM IN WESTERN MASS SUNDAY BUT KEEP
THE REST OF THE AREA DRY.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE.
IFR CIGS/VSBYS SPREAD BACK TOWARD CAPE COD CANAL THIS EVENING.
VFR ELSEWHERE THROUGH EARLY TONIGHT WITH AREAS MVFR/IFR IN
SHOWERS/TSTMS...WHICH WILL BE MORE NUMEROUS ACROSS WESTERN AND N
CENTRAL MA BUT ALSO ACROSS N CT. POTENTIAL FOR 50KT GUSTS AND
TORRENTIAL RAINFALL IN STRONGER STORMS.
SLOW IMPROVEMENT TO VFR 12Z-15Z MON NEAR S COAST...CAPE COD AND
ISLANDS. SCATTERED TSTMS POSSIBLE IN THESE AREAS 18Z-23Z. VFR
ELSEWHERE.
KBOS TAF...MODERATE CONFIDENCE. MAIN TIME FRAME FOR STORMS IS 01
TO 04Z. POTENTIAL FOR 40-50KT GUSTS AND TORRENTIAL RAINFALL.
KBDL TAF...MODERATE CONFIDENCE. MAIN TIME FRAME IS 02Z TO 05Z.
POTENTIAL FOR 40-50KT GUSTS AND TORRENTIAL RAINFALL.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...MODERATE CONFIDENCE.
MONDAY NIGHT...VFR NORTH AND TRENDING VFR SOUTH. PATCHY IFR LATE IN
FOG.
TUESDAY... VFR MOST OF THE DAY. SOME SCATTERED MVFR CIGS/VSBYS IN
SHOWERS/TSTMS ALONG AN AFTERNOON/EVENING COLD FRONT.
WEDNESDAY-THURSDAY...
VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
*** POTENTIAL FOR STRONG OR SEVERE STORMS TOWARD EVENING ***
HIGH CONFIDENCE IN WINDS AND SEAS BELOW SCA THROUGH MON. MAIN
CONCERN IS POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS TOWARD
EVENING...WHICH MAY PRODUCE STRONG WIND GUSTS...TORRENTIAL
RAINFALL WITH POOR VISIBILITY AND DANGEROUS LIGHTNING. HIGHEST
RISK FOR THESE STORMS IS ON WATERS AROUND CAPE ANN...BUT IS ALSO
POSSIBLE ELSEWHERE.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...MODERATE TO HIGH CONFIDENCE.
MONDAY NIGHT...LINGERING SHOWERS/TSTMS ALONG THE SOUTHERN WATERS IN
THE EVENING...DIMINISHING OVERNIGHT. AREAS OF POOR VSBYS IN FOG
TOWARD MORNING. WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT
THRESHOLDS.
TUESDAY...A COLD FRONT SWINGS ACROSS THE WATERS DURING THE LATE
AFTERNOON/EVENING WITH SCATTERED SHOWERS/TSTMS. WINDS BELOW 25
KNOTS/SEAS BELOW 5 FEET.
WEDNESDAY-THURSDAY...WINDS AND SEAS REMAIN BELOW SMALL CRAFT
THRESHOLDS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WTB/JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...WTB
AVIATION...WTB/JWD
MARINE...WTB/JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
549 PM EDT SUN JUL 19 2015
.SYNOPSIS...
SEVERE THUNDERSTORMS SHOULD DEVELOP NORTH OF THE MASSACHUSETTS
TURNPIKE THIS EVENING...AND MAY MERGE INTO A COMPLEX OF STORMS
WITH THE POTENTIAL FOR DAMAGING WINDS AND LOCALIZED FLOODING. A
COLD FRONT WILL DROP THROUGH NEW ENGLAND MONDAY AND MAY TRIGGER
SCATTERED THUNDERSTORMS NEAR THE SOUTH COAST. A COLD FRONT SWEEPS
THROUGH THE REGION TUESDAY. HIGH PRESSURE BUILDS OVER THE REGION
FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
550 PM UPDATE...
*** MONITORING SEVERE STORMS IN E NY AS THEY HEAD INTO SNE ***
AFTER COLLABORATION WITH SPC AND WFO ALBANY...DECIDED TO EXPAND
SEVERE THUNDERSTORM WATCH 442 TO INCLUDE NORTHERN CT. IT REMAINS
IN EFFECT FOR WESTERN...CENTRAL AND NE MA.
CONVECTION HAS BLOSSOMED ACROSS CENTRAL/EASTERN NY IN AXIS OF
HIGHER ML CAPE...K INDEX AND MORE ORGANIZED SHEAR AHEAD OF MID
LEVEL SHORT WAVE. THIS AIRMASS WILL SHIFT E INTO NEW ENGLAND THIS
EVENING...SO TIMING FOR SEVERE WEATHER IS ROUGHLY 6 PM TO
MIDNIGHT.
MAIN HAZARDS ARE WIND DAMAGE AND EVEN LARGE HAIL DESPITE TROPICAL
AIRMASS IN PLACE. STRONG SHEAR AND FAT CAPE PROFILE IS CERTAINLY
HELPING IN THAT REGARD. STILL NEED TO WATCH FOR ISOLATED TORNADOES
AS ENVIRONMENT REMAINS FAVORABLE. ALREADY SEEING ONE STORM IN E
NY WHICH IS A RIGHT MOVER WITH STRONG ROTATION AND IS UNDER A
TORNADO WARNING.
20Z HRRR SEEMS TO HAVE RIGHT IDEA WITH REGARD TO EVOLUTION OF
STORM THREAT IN SNE...ALTHOUGH IT WEAKENS ACTIVITY AS IT MOVES
THROUGH WHICH IS DOUBTFUL. TIMING WOULD BE 6-7 PM AROUND
SPRINGFIELD...7-8 PM IN WORCESTER AND 8-9 PM FOR NE MA. BEST BET
IS TO MONITOR RADAR TRENDS.
ONCE THIS INITIAL BATCH OF ACTIVITY MOVES THROUGH DURING FIRST
PART OF TONIGHT...SOME QUESTION AS TO WHETHER OR NOT ADDITIONAL
ACTIVITY CAN REDEVELOP AS AIRMASS REMAINS UNSTABLE WITH EML IN
PLACE. COULD EASILY BE LOOKING AT JUST WIDELY SCATTERED STORMS
LATE TONIGHT...OR IF EVERYTHING COMES TOGETHER...A MORE ORGANIZED
CONVECTIVE COMPLEX.
HEAT ADVISORY WILL BE ALLOWED TO EXPIRE AT 6 PM.
FINALLY...AREAS OF FOG AND LOW CLOUDS AROUND NANTUCKET WILL SPREAD
INLAND THROUGH THIS EVENING...MAINLY TO CAPE COD CANAL AND S
COAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
FRONT DROPS TOWARD S COAST MON WHICH IS WHERE WE WILL HAVE CHANCE
POPS FOR AFTERNOON STORMS. MODELS SHOW FAIRLY DECENT CAPE AND
SHEAR BUT IT ALL COMES DOWN TO TIMING. STILL LOOKS LIKE A HOT DAY
BUT A LITTLE LESS HUMID THAN TODAY WITH HIGHS IN 80S.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE... ZONAL FLOW AT THE START OF THE WEEK EVOLVES
MIDWEEK AS PART OF HUDSON BAY LOW DIVES FARTHER SOUTHEAST AND
CARVES OUT A TROUGH OVER THE NORTHEAST USA. CYCLONIC FLOW LINGERS
OVER NEW ENGLAND THROUGH AT LEAST FRIDAY. A SHORTWAVE RIDGE BUILDS
IN OVER THE WEEKEND. ABOVE NORMAL HEIGHTS AT THE START OF THE WEEK
ARE SUPPRESSED BY THE TROUGH TO 100 METERS BELOW NORMAL MIDWEEK.
HEIGHTS RETURN TO NEAR NORMAL BY NEXT SUNDAY.
THE VARIOUS LONG RANGE MODEL GUIDANCE ARE IN AGREEMENT THROUGH
THE PERIOD. WE FAVOR THIS MODEL BLEND FOR THIS FORECAST.
THE DAILIES...
MONDAY NIGHT... COLD FRONT ALONG THE SOUTH COAST MOVES OFFSHORE. ANY
LINGERING SHOWERS/TSTMS SHOULD MOVE OFF AT THAT TIME. OTHERWISE FAIR
SKIES AND LIGHT WINDS THROUGH THE NIGHT...WHICH WILL ALLOW PATCHES
OF FOG TO FORM LATE AT NIGHT.
TUESDAY... SHORTWAVE APPROACHES FROM THE GREAT LAKES WHILE DRIVING A
SECOND COLD FRONT EAST INTO NEW ENGLAND. THE SUPPORTING 90-KNOT JET
APPROACHES WITH THE LEFT EXIT REGION OF THE JET IN PLACE OVERHEAD
DURING THE DAY. DAYTIME HEATING WILL SUPPORT MIXING TO 800 MB. TEMPS
AT 850 MB WILL BE AROUND 18C...MIXING FROM 800 MB YIELDS SIMILAR
RESULTS. THIS WOULD SUPPORT MAX TEMPS NEAR 90. GUIDANCE IS
SEVERAL DEGREES COOLER...SO WILL BUMP THOSE VALUES UP 2-3F TO
BRING MAX SFC VALUES IN THE UPPER 80S INLAND. STABILITY PARAMETERS
ARE FAVORABLE FOR CONVECTION WITH SBCAPE AROUND 1000/SLI AROUND
ZERO/TOTALS 45-49. THIS WILL BRING CLOUDS AND SCATTERED CONVECTION
TO THE REGION...WE WILL HAVE CHANCE POPS TUESDAY AFTERNOON WITH
THE FRONTAL PASSAGE.
WEDNESDAY THROUGH FRIDAY... UPPER TROUGH HANGS OVER THE NORTHEAST
WITH COOLER TEMPS AND MOISTURE POOL ALOFT CREATING A MORE UNSTABLE
AIRMASS WITH DAYTIME HEATING CAUSING DIURNAL CLOUDS AND POSSIBLY A
FEW LIGHT SHOWERS. SEVERAL SHORTWAVES MOVE THROUGH THE FLOW DURING
THIS PERIOD ADDING TO THE CHANCE OF CLOUDS AND SHOWERS. BEST CHANCE
FOR THIS WILL BE IN NORTHERN MASSACHUSETTS.
SATURDAY AND SUNDAY... LONGWAVE AND SHORTWAVE CONTOUR FIELDS SHOW
HIGH PRESSURE BUILDING SURFACE AND ALOFT. THIS WOULD SUGGEST FAIR
DRY WEATHER WITH TEMPERATURES NEAR NORMAL. THE GFS AND ECMWF DO
SHOW A SHORTWAVE SLIPPING THROUGH ON SUNDAY EVAN AS THE HEIGHTS
TREND HIGHER. THIS WOULD SUGGEST A CHANCE OF A FEW SHOWERS. WE WILL
MENTION A CHANCE OF A THUNDERSTORM IN WESTERN MASS SUNDAY BUT KEEP
THE REST OF THE AREA DRY.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE.
IFR CIGS/VSBYS AROUND ACK WILL GRADUALLY SPREAD BACK TOWARD CAPE
COD CANAL THIS EVENING. VFR ELSEWHERE THROUGH EARLY TONIGHT WITH
AREAS MVFR/IFR IN SHOWERS/TSTMS...WHICH SHOULD BE MORE NUMEROUS
ACROSS WESTERN AND N CENTRAL MA. POTENTIAL FOR 50KT GUSTS AND
TORRENTIAL RAINFALL.
SLOW IMPROVEMENT TO VFR 12Z-15Z MON NEAR S COAST...CAPE COD AND
ISLANDS. SCATTERED TSTMS POSSIBLE IN THESE AREAS 18Z-23Z. VFR
ELSEWHERE.
KBOS TAF...MODERATE CONFIDENCE. SE SEA BREEZE SHIFTS TO S THIS
AFTERNOON. UNCERTAINTY IS DUE TO COVERAGE OF TSTMS...IF WE SEE
FEW STORMS IN TERMINAL AREA OR MORE ORGANIZED COMPLEX. MAIN TIME
FRAME IS 21Z TO 02Z. POTENTIAL FOR 40-50KT GUSTS AND TORRENTIAL
RAINFALL.
KBDL TAF...MODERATE CONFIDENCE. UNCERTAINTY IS DUE TO COVERAGE OF
TSTMS...IF WE SEE FEW STORMS IN TERMINAL AREA OR MORE ORGANIZED
COMPLEX. MAIN TIME FRAME IS 22Z TO 03Z. POTENTIAL FOR 40-50KT
GUSTS AND TORRENTIAL RAINFALL.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...MODERATE CONFIDENCE.
MONDAY NIGHT...VFR NORTH AND TRENDING VFR SOUTH. PATCHY IFR LATE IN
FOG.
TUESDAY... VFR MOST OF THE DAY. SOME SCATTERED MVFR CIGS/VSBYS IN
SHOWERS/TSTMS ALONG AN AFTERNOON/EVENING COLD FRONT.
WEDNESDAY-THURSDAY...
VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
*** POTENTIAL FOR STRONG OR SEVERE STORMS TOWARD EVENING ***
HIGH CONFIDENCE IN WINDS AND SEAS BELOW SCA THROUGH MON. MAIN
CONCERN IS POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS TOWARD
EVENING...WHICH MAY PRODUCE STRONG WIND GUSTS...TORRENTIAL
RAINFALL WITH POOR VISIBILITY AND DANGEROUS LIGHTNING. HIGHEST
RISK FOR THESE STORMS IS ON WATERS AROUND CAPE ANN...BUT IS ALSO
POSSIBLE ELSEWHERE.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...MODERATE TO HIGH CONFIDENCE.
MONDAY NIGHT...LINGERING SHOWERS/TSTMS ALONG THE SOUTHERN WATERS IN
THE EVENING...DIMINISHING OVERNIGHT. AREAS OF POOR VSBYS IN FOG
TOWARD MORNING. WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT
THRESHOLDS.
TUESDAY...A COLD FRONT SWINGS ACROSS THE WATERS DURING THE LATE
AFTERNOON/EVENING WITH SCATTERED SHOWERS/TSTMS. WINDS BELOW 25
KNOTS/SEAS BELOW 5 FEET.
WEDNESDAY-THURSDAY...WINDS AND SEAS REMAIN BELOW SMALL CRAFT
THRESHOLDS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR CTZ002.
MA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MAZ010-011.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WTB/JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...WTB
AVIATION...WTB/JWD
MARINE...WTB/JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
525 PM EDT SUN JUL 19 2015
.SYNOPSIS...
SEVERE THUNDERSTORMS SHOULD DEVELOP NORTH OF THE MASSACHUSETTS
TURNPIKE THIS EVENING...AND MAY MERGE INTO A COMPLEX OF STORMS
WITH THE POTENTIAL FOR DAMAGING WINDS AND LOCALIZED FLOODING. A
COLD FRONT WILL DROP THROUGH NEW ENGLAND MONDAY AND MAY TRIGGER
SCATTERED THUNDERSTORMS NEAR THE SOUTH COAST. A COLD FRONT SWEEPS
THROUGH THE REGION TUESDAY. HIGH PRESSURE BUILDS OVER THE REGION
FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
525 PM UPDATE...
*** MONITORING SEVERE STORMS IN E NY AS THEY HEAD INTO SNE ***
CONVECTION HAS BLOSSOMED ACROSS CENTRAL/EASTERN NY IN AXIS OF
HIGHER ML CAPE...K INDEX AND MORE ORGANIZED SHEAR AHEAD OF MID
LEVEL SHORT WAVE. THIS AIRMASS WILL SHIFT E INTO NEW ENGLAND THIS
EVENING...SO TIMING FOR SEVERE WEATHER IS ROUGHLY 6 PM TO
MIDNIGHT. SEVERE THUNDERSTORM WATCH 442 REMAINS IN EFFECT FOR
WESTERN...CENTRAL AND NORTHEAST MA.
MAIN HAZARDS ARE WIND DAMAGE AND EVEN LARGE HAIL DESPITE TROPICAL
AIRMASS IN PLACE. STRONG SHEAR AND FAT CAPE PROFILE IS CERTAINLY
HELPING IN THAT REGARD. STILL NEED TO WATCH FOR ISOLATED TORNADOES
AS ENVIRONMENT REMAINS FAVORABLE. ALREADY SEEING ONE STORM IN E
NY WHICH IS A RIGHT MOVER WITH STRONG ROTATION AND IS UNDER A
TORNADO WARNING.
20Z HRRR SEEMS TO HAVE RIGHT IDEA WITH REGARD TO EVOLUTION OF
STORM THREAT IN SNE...ALTHOUGH IT WEAKENS ACTIVITY AS IT MOVES
THROUGH WHICH IS DOUBTFUL. TIMING WOULD BE 6-7 PM AROUND
SPRINGFIELD...7-8 PM IN WORCESTER AND 8-9 PM FOR NE MA. BEST BET
IS TO MONITOR RADAR TRENDS.
ONCE THIS INITIAL BATCH OF ACTIVITY MOVES THROUGH DURING FIRST
PART OF TONIGHT...SOME QUESTION AS TO WHETHER OR NOT ADDITIONAL
ACTIVITY CAN REDEVELOP AS AIRMASS REMAINS UNSTABLE WITH EML IN
PLACE. COULD EASILY BE LOOKING AT JUST WIDELY SCATTERED STORMS
LATE TONIGHT...OR IF EVERYTHING COMES TOGETHER...A MORE ORGANIZED
CONVECTIVE COMPLEX.
HEAT ADVISORY WILL BE ALLOWED TO EXPIRE AT 6 PM.
FINALLY...AREAS OF FOG AND LOW CLOUDS AROUND NANTUCKET WILL SPREAD
INLAND THROUGH THIS EVENING...MAINLY TO CAPE COD CANAL AND S
COAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
FRONT DROPS TOWARD S COAST MON WHICH IS WHERE WE WILL HAVE CHANCE
POPS FOR AFTERNOON STORMS. MODELS SHOW FAIRLY DECENT CAPE AND
SHEAR BUT IT ALL COMES DOWN TO TIMING. STILL LOOKS LIKE A HOT DAY
BUT A LITTLE LESS HUMID THAN TODAY WITH HIGHS IN 80S.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
BIG PICTURE... ZONAL FLOW AT THE START OF THE WEEK EVOLVES
MIDWEEK AS PART OF HUDSON BAY LOW DIVES FARTHER SOUTHEAST AND
CARVES OUT A TROUGH OVER THE NORTHEAST USA. CYCLONIC FLOW LINGERS
OVER NEW ENGLAND THROUGH AT LEAST FRIDAY. A SHORTWAVE RIDGE BUILDS
IN OVER THE WEEKEND. ABOVE NORMAL HEIGHTS AT THE START OF THE WEEK
ARE SUPPRESSED BY THE TROUGH TO 100 METERS BELOW NORMAL MIDWEEK.
HEIGHTS RETURN TO NEAR NORMAL BY NEXT SUNDAY.
THE VARIOUS LONG RANGE MODEL GUIDANCE ARE IN AGREEMENT THROUGH
THE PERIOD. WE FAVOR THIS MODEL BLEND FOR THIS FORECAST.
THE DAILIES...
MONDAY NIGHT... COLD FRONT ALONG THE SOUTH COAST MOVES OFFSHORE. ANY
LINGERING SHOWERS/TSTMS SHOULD MOVE OFF AT THAT TIME. OTHERWISE FAIR
SKIES AND LIGHT WINDS THROUGH THE NIGHT...WHICH WILL ALLOW PATCHES
OF FOG TO FORM LATE AT NIGHT.
TUESDAY... SHORTWAVE APPROACHES FROM THE GREAT LAKES WHILE DRIVING A
SECOND COLD FRONT EAST INTO NEW ENGLAND. THE SUPPORTING 90-KNOT JET
APPROACHES WITH THE LEFT EXIT REGION OF THE JET IN PLACE OVERHEAD
DURING THE DAY. DAYTIME HEATING WILL SUPPORT MIXING TO 800 MB. TEMPS
AT 850 MB WILL BE AROUND 18C...MIXING FROM 800 MB YIELDS SIMILAR
RESULTS. THIS WOULD SUPPORT MAX TEMPS NEAR 90. GUIDANCE IS
SEVERAL DEGREES COOLER...SO WILL BUMP THOSE VALUES UP 2-3F TO
BRING MAX SFC VALUES IN THE UPPER 80S INLAND. STABILITY PARAMETERS
ARE FAVORABLE FOR CONVECTION WITH SBCAPE AROUND 1000/SLI AROUND
ZERO/TOTALS 45-49. THIS WILL BRING CLOUDS AND SCATTERED CONVECTION
TO THE REGION...WE WILL HAVE CHANCE POPS TUESDAY AFTERNOON WITH
THE FRONTAL PASSAGE.
WEDNESDAY THROUGH FRIDAY... UPPER TROUGH HANGS OVER THE NORTHEAST
WITH COOLER TEMPS AND MOISTURE POOL ALOFT CREATING A MORE UNSTABLE
AIRMASS WITH DAYTIME HEATING CAUSING DIURNAL CLOUDS AND POSSIBLY A
FEW LIGHT SHOWERS. SEVERAL SHORTWAVES MOVE THROUGH THE FLOW DURING
THIS PERIOD ADDING TO THE CHANCE OF CLOUDS AND SHOWERS. BEST CHANCE
FOR THIS WILL BE IN NORTHERN MASSACHUSETTS.
SATURDAY AND SUNDAY... LONGWAVE AND SHORTWAVE CONTOUR FIELDS SHOW
HIGH PRESSURE BUILDING SURFACE AND ALOFT. THIS WOULD SUGGEST FAIR
DRY WEATHER WITH TEMPERATURES NEAR NORMAL. THE GFS AND ECMWF DO
SHOW A SHORTWAVE SLIPPING THROUGH ON SUNDAY EVAN AS THE HEIGHTS
TREND HIGHER. THIS WOULD SUGGEST A CHANCE OF A FEW SHOWERS. WE WILL
MENTION A CHANCE OF A THUNDERSTORM IN WESTERN MASS SUNDAY BUT KEEP
THE REST OF THE AREA DRY.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE.
IFR CIGS/VSBYS AROUND ACK WILL GRADUALLY SPREAD BACK TOWARD CAPE
COD CANAL THIS EVENING. VFR ELSEWHERE THROUGH EARLY TONIGHT WITH
AREAS MVFR/IFR IN SHOWERS/TSTMS...WHICH SHOULD BE MORE NUMEROUS
ACROSS WESTERN AND N CENTRAL MA. POTENTIAL FOR 50KT GUSTS AND
TORRENTIAL RAINFALL.
SLOW IMPROVEMENT TO VFR 12Z-15Z MON NEAR S COAST...CAPE COD AND
ISLANDS. SCATTERED TSTMS POSSIBLE IN THESE AREAS 18Z-23Z. VFR
ELSEWHERE.
KBOS TAF...MODERATE CONFIDENCE. SE SEA BREEZE SHIFTS TO S THIS
AFTERNOON. UNCERTAINTY IS DUE TO COVERAGE OF TSTMS...IF WE SEE
FEW STORMS IN TERMINAL AREA OR MORE ORGANIZED COMPLEX. MAIN TIME
FRAME IS 21Z TO 02Z. POTENTIAL FOR 40-50KT GUSTS AND TORRENTIAL
RAINFALL.
KBDL TAF...MODERATE CONFIDENCE. UNCERTAINTY IS DUE TO COVERAGE OF
TSTMS...IF WE SEE FEW STORMS IN TERMINAL AREA OR MORE ORGANIZED
COMPLEX. MAIN TIME FRAME IS 22Z TO 03Z. POTENTIAL FOR 40-50KT
GUSTS AND TORRENTIAL RAINFALL.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...MODERATE CONFIDENCE.
MONDAY NIGHT...VFR NORTH AND TRENDING VFR SOUTH. PATCHY IFR LATE IN
FOG.
TUESDAY... VFR MOST OF THE DAY. SOME SCATTERED MVFR CIGS/VSBYS IN
SHOWERS/TSTMS ALONG AN AFTERNOON/EVENING COLD FRONT.
WEDNESDAY-THURSDAY...
VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
*** POTENTIAL FOR STRONG OR SEVERE STORMS TOWARD EVENING ***
HIGH CONFIDENCE IN WINDS AND SEAS BELOW SCA THROUGH MON. MAIN
CONCERN IS POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS TOWARD
EVENING...WHICH MAY PRODUCE STRONG WIND GUSTS...TORRENTIAL
RAINFALL WITH POOR VISIBILITY AND DANGEROUS LIGHTNING. HIGHEST
RISK FOR THESE STORMS IS ON WATERS AROUND CAPE ANN...BUT IS ALSO
POSSIBLE ELSEWHERE.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...MODERATE TO HIGH CONFIDENCE.
MONDAY NIGHT...LINGERING SHOWERS/TSTMS ALONG THE SOUTHERN WATERS IN
THE EVENING...DIMINISHING OVERNIGHT. AREAS OF POOR VSBYS IN FOG
TOWARD MORNING. WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT
THRESHOLDS.
TUESDAY...A COLD FRONT SWINGS ACROSS THE WATERS DURING THE LATE
AFTERNOON/EVENING WITH SCATTERED SHOWERS/TSTMS. WINDS BELOW 25
KNOTS/SEAS BELOW 5 FEET.
WEDNESDAY-THURSDAY...WINDS AND SEAS REMAIN BELOW SMALL CRAFT
THRESHOLDS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR CTZ002.
MA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MAZ010-011.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WTB/JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...WTB
AVIATION...WTB/JWD
MARINE...WTB/JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
109 PM EDT SUN JUL 19 2015
.SYNOPSIS...
HOT AND HUMID WEATHER IS ON TAP FOR THIS AFTERNOON. ISOLATED
SEVERE THUNDERSTORMS SHOULD DEVELOP NORTH OF THE MASSACHUSETTS
TURNPIKE BY LATE AFTERNOON OR EARLY EVENING...AND MAY MERGE INTO
A COMPLEX OF STORMS THIS EVENING WITH THE POTENTIAL FOR HEAVY
RAINFALL/LOCALIZED FLOODING ALONG WITH STRONG WIND GUSTS.
&&
.NEAR TERM /THROUGH TONIGHT/...
110 PM UPDATE...
*** SEVERE STORMS POSSIBLE 4 PM TO MIDNIGHT ***
15Z HRRR SHOWS EXPECTED EVOLUTION OF CONVECTION NICELY...ALTHOUGH
MAY BE QUESTIONABLE AS TO AREAS THAT ARE IMPACTED. INITIAL BAND OF
SHOWERS PUSHING THROUGH SOUTHERN NEW ENGLAND WILL DIMINISH AS IT
HEADS E AND ENCOUNTERS LESS FAVORABLE AIRMASS THAT IS STILL
CAPPED. STILL HAVE ML CAPES AROUND 1500 AND WEAK SHEAR...BUT BETTER
INSTABILITY AND SHEAR IS PRESENTLY LOCATED ACROSS CENTRAL NY/PA
WHERE WE THINK CONVECTION WILL INITIATE THROUGH 3 PM. IT IS THIS
ACTIVITY AHEAD OF MID LEVEL SHORT WAVE THAT WILL REACH SOUTHERN
NEW ENGLAND TOWARD EVENING AND LIKELY CONTINUE THROUGH EARLY
TONIGHT. WHETHER OR NOT IT TRACKS N OF OUR AREA OR COMES RIGHT
THROUGH REMAINS TO BE SEEN...BUT FOR NOW BANKING ON AT LEAST
SCATTERED THUNDERSTORMS DURING THIS TIME FRAME.
CONVECTIVE PARAMETERS FAVOR WIND DAMAGE AS MAIN THREAT BUT WITH
STRONG SHEAR AND TROPICAL AIRMASS IN PLACE /LOW LCL/ CANNOT RULE
OUT ISOLATED TORNADO SOMEWHERE IN NORTHEAST.
ONCE THIS INITIAL BATCH OF ACTIVITY MOVES THROUGH DURING FIRST
PART OF TONIGHT...SOME QUESTION AS TO WHETHER OR NOT ADDITIONAL
ACTIVITY CAN REDEVELOP AS AIRMASS REMAINS UNSTABLE WITH EML IN
PLACE. COULD EASILY BE LOOKING AT JUST WIDELY SCATTERED STORMS
LATE TONIGHT...OR IF EVERYTHING COMES TOGETHER...A MORE ORGANIZED
CONVECTIVE COMPLEX.
REGARDING HEAT ADVISORY...KEEPING IT IN PLACE FOR PARTS OF CT
VALLEY WHERE HEAT INDICES WILL PEAK AROUND 100 THIS AFTERNOON.
WILL ALSO COME CLOSE ACROSS INTERIOR E MA BUT NOT AS CONFIDENT
THERE.
&&
.SHORT TERM /MONDAY/...
FRONT DROPS TOWARD S COAST MON WHICH IS WHERE WE WILL HAVE CHANCE
POPS FOR AFTERNOON STORMS. MODELS SHOW FAIRLY DECENT CAPE AND
SHEAR BUT IT ALL COMES DOWN TO TIMING. STILL LOOKS LIKE A HOT DAY
BUT A LITTLE LESS HUMID THAN TODAY WITH HIGHS IN 80S.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
OVERVIEW AND MODEL PREFERENCES...
THE PRIMARY CHANGE WITH THIS FORECAST UPDATE IS NOTING THE SHIFT
FROM A NEARLY PERFECT ZONAL MEAN JET THROUGH THE LONG TERM...TO
NOW A SLIGHTLY MORE AMPLIFIED FLOW PATTERN. THE ISSUE IS THE
BIFURCATING CUTOFF ACROSS CANADA...THE EASTERN LOBE NOW LOOKS TO
SETTLE A BIT FURTHER SOUTHEAST THROUGH THE MID TERM. THIS YIELDS
CYCLONIC CURVATURE ALOFT FOR MUCH THROUGH MID WEEK AT LEAST.
SO...IN ESSENCE...HIGHER LIKELIHOOD OF A PERIOD OF BELOW NORMAL
OVERALL TEMPS COMBINED WITH MORE CLOUDS AND A HIGHER RISK OF RAFL
WITH A SHORTWAVE PASSAGE ON TUE. H5 HEIGHTS AND H85 TEMPS ARE
MAINLY BELOW NORMAL PER LATEST ENSEMBLES. THIS SLIGHTLY MORE
AMPLIFIED FLOW DOES HAVE A SOMEWHAT HAPPY ENDING...IN THE FORM OF
A STRONGER RIDGE TO BUILD OVER LATER IN THE WEEK/WEEKEND...WHICH
COULD ALLOW FOR A DRIER...BUT MORE SUMMER-LIKE PERIOD.
DETAILS...
TUE AND TUE NIGHT... AN ENHANCED SHORTWAVE WILL BE ROTATING
THROUGH THE CYCLONIC FLOW THROUGH THE REGION WITH A COLD FRONT
APPROACHING FROM THE N...AND THE POSSIBILITY OF A WEAK WAVE
DEVELOPING ALONG THE STALLED FRONT TO THE S. SOME INCREASE IN
OVERALL COLUMN MOISTURE NOTED BUT LOWEST LVLS LOOK TO REMAIN DRY.
ALSO...WITH TWO LIFT SOURCES...ONE N AND ONE S...SUSPECT AN AREA
OF DESCENT SOMEWHERE IN BETWEEN THEREFORE...ASIDE FROM INCREASING
CLOUDS...WILL LIMIT POPS THROUGH THE PERIOD TO MAINLY SLIGHT
CHANCE FOR THE INTERIOR. WILL GO A BIT HIGHER NEAR THE S COAST AS
THE DEVELOPING WAVE COULD FIGURE SOME CONVECTIVE
ENHANCEMENT...INCREASING THE RISK FOR EXPERIENCING RAINFALL.
WED AND THU...
MAINLY DRY WX AS WEAK RIDGING BUILDS OVER. H85 TEMPS ARE ALMOST
4C BELOW THEIR SEASONAL NORMALS...SO WILL LIKELY SEE TEMPS REFLECT
THIS...MAINLY BELOW NORMAL.
FRI...
ANOTHER SHORTWAVE PASSAGE WITH ASSOCIATED COLD FRONT. LIMITING
FACTOR IS ONCE AGAIN COLUMN MOISTURE WHICH IS LIKELY TO BE LOW.
THEREFORE...WILL LIMIT POPS TO LOW END CHANCE AND SLIGHT CHANCE.
NEXT WEEKEND...
TIMING STILL A BIT UNCERTAIN BUT WITH A BUILDING RIDGE TO THE
W...WILL ADJUST TOWARD A DRIER PERIOD WITH MODERATING
TEMPERATURES...BUT WITH THE CUTOFF JUST TO THE NE...WILL STILL
NEED TO WATCH THIS PERIOD AS ANY KINK IN THE ISOBARS COULD YIELD
VERY DIFFERENT RESULTS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE.
IFR CIGS/VSBYS AROUND ACK WILL GRADUALLY SPREAD BACK TOWARD CAPE
COD CANAL THIS EVENING. VFR ELSEWHERE THROUGH EARLY TONIGHT WITH
AREAS MVFR/IFR IN SHOWERS/TSTMS...WHICH SHOULD BE MORE NUMEROUS
ACROSS WESTERN AND N CENTRAL MA. POTENTIAL FOR 50KT GUSTS AND
TORRENTIAL RAINFALL.
SLOW IMPROVEMENT TO VFR 12Z-15Z MON NEAR S COAST...CAPE COD AND
ISLANDS. SCATTERED TSTMS POSSIBLE IN THESE AREAS 18Z-23Z. VFR
ELSEWHERE.
KBOS TAF...MODERATE CONFIDENCE. SE SEA BREEZE SHIFTS TO S THIS
AFTERNOON. UNCERTAINTY IS DUE TO COVERAGE OF TSTMS...IF WE SEE
FEW STORMS IN TERMINAL AREA OR MORE ORGANIZED COMPLEX. MAIN TIME
FRAME IS 21Z TO 02Z. POTENTIAL FOR 40-50KT GUSTS AND TORRENTIAL
RAINFALL.
KBDL TAF...MODERATE CONFIDENCE. UNCERTAINTY IS DUE TO COVERAGE OF
TSTMS...IF WE SEE FEW STORMS IN TERMINAL AREA OR MORE ORGANIZED
COMPLEX. MAIN TIME FRAME IS 22Z TO 03Z. POTENTIAL FOR 40-50KT
GUSTS AND TORRENTIAL RAINFALL.
OUTLOOK...TUESDAY THROUGH THURSDAY...
TUE...MODERATE CONFIDENCE.
MAINLY VFR ALTHOUGH WITH A WEAK WAVE OF LOW PRES MOVING S...AND A
COLD FRONT APPROACHING FROM THE N...ISOLATED LOWER CATEGORIES IN
SHOWERS ARE POSSIBLE.
WED AND THU...HIGH CONFIDENCE.
MAINLY VFR WITH A RETURN OF HIGH PRES.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
*** POTENTIAL FOR STRONG OR SEVERE STORMS TOWARD EVENING ***
HIGH CONFIDENCE IN WINDS AND SEAS BELOW SCA THROUGH MON. MAIN
CONCERN IS POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS TOWARD
EVENING...WHICH MAY PRODUCE STRONG WIND GUSTS...TORRENTIAL
RAINFALL WITH POOR VISIBILITY AND DANGEROUS LIGHTNING. HIGHEST
RISK FOR THESE STORMS IS ON WATERS AROUND CAPE ANN...BUT IS ALSO
POSSIBLE ELSEWHERE.
OUTLOOK...TUESDAY THROUGH THURSDAY...
TUE...MODERATE CONFIDENCE.
A COLD FRONT WILL STALL JUST S OF THE WATERS MON...WITH A RISK
FOR SHOWERS AND OCCASIONAL THUNDERSTORMS. A WEAK WAVE OF LOW PRES
WILL DEVELOP ALONG THE FRONT TUE AS A SECONDARY FRONT APPROACHES
FROM THE NORTHWEST. ALTHOUGH WINDS AND SEAS SHOULD GENERALLY
REMAIN BELOW SMALL CRAFT THRESHOLDS THROUGH THIS PERIOD...SOME
SHOWERS AND T-STORMS MAY YIELDS ROUGH SEAS AND STRONGER WINDS.
WED AND THU...HIGH CONFIDENCE.
HIGH PRES MOVES OVER THE WATERS WITH QUIETER BOATING WEATHER
EXPECTED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR CTZ002.
MA...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR MAZ010-011.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...DOODY
AVIATION...WTB/JWD
MARINE...WTB/JWD
AREA FORECAST DISCUSSION
NWS MIAMI FL
136 PM EDT SUN JUL 19 2015
.AVIATION...
FORECAST REASONING HAS NOT CHANGE WITH MOSTLY VFR CONDITIONS EXPECTED
THROUGH THE FORECAST PERIOD. HOWEVER, TSRA ARE DEVELOPING ALONG
SEA BREEZE BOUNDARIES AND WILL CONTINUE INTO THE AFTERNOON WITH
OUTFLOW BOUNDARIES INDUCING ADDITIONAL STORMS. SOME OF THESE
OUTFLOWS HAVE ALREADY AFFECTED THE EAST COAST TERMINALS SO JUST
WENT VRB FOR THOSE LOCATIONS AS IT WILL HARD TO SAY WHETHER SEA
BREEZE WILL BE ABLE TO OVERCOME THIS LATER IN THE AFTERNOON. MORE
OF THE SAME ON MONDAY BUT DRIER AIR WILL LIKELY DELAY THE ONSET
OF CONVECTION SO LEFT OUT MENTION FOR NOW THROUGH 18Z.
KOB
&&
.PREV DISCUSSION... /ISSUED 952 AM EDT SUN JUL 19 2015/
UPDATE...
MADE SOME MINOR ADJUSTMENTS EARLIER TO ACCOUNT FOR THE LATEST
TRENDS WHICH MAINLY DELAYED TIMING OF THE INITIALIZATION OF
SHOWERS AND STORMS. NO OTHER CHANGES APPEAR TO BE IMMINENT AT THIS
TIME WITH THE 12Z MFL SOUNDING SHOWING THE ATMOSPHERE HAS DRIED
AS PREDICTED WITH THE PWAT FALLING TO 1.66" AND THE MID LEVEL
LAPSE RATES CONTINUE TO BE MEAGER. ALSO, THERE ARE TWO SMALL
INVERSIONS WITH ONE AT 850MB AND THE OTHER AT 700MB ALONG WITH THE
500MB TEMPERATURE WARMED SLIGHTLY. ALL OF THESE COMBINED WILL
RESULT IN A LATER START TO STORM DEVELOPMENT THAN THE PAST COUPLE
OF DAYS AND LESS COVERAGE. HOWEVER, THE LOW LEVEL WIND FIELD ALSO
DECREASED SIGNIFICANTLY SO STORM MOTION WILL BE LESS THAN 5MPH.
THAT BEING SAID, STORMS WILL TEND TO DEVELOP ALONG SEA BREEZE
BOUNDARIES AND THEN SLOWLY MOVE INLAND ALONG THE CONVERGENCE ZONE
BUT AS THESE GROW OUTFLOW BOUNDARIES WILL INDUCE OTHER DEVELOPMENT
SO STORMS COULD JUST ABOUT AFFECT ANYWHERE. THE DRIER AIR ALOFT
COULD ALSO CAUSE THE STRONGER CELLS TO PRODUCE STRONG WIND GUSTS
AND PERHAPS SMALL HAIL. SO ALL THIS BEING SAID, THE HWO LOOKS TO
BE IN GOOD SHAPE AND NO REASON TO CHANGE AT THIS TIME.
KOB
PREV DISCUSSION... /ISSUED 736 AM EDT SUN JUL 19 2015/
AVIATION...
MOSTLY VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.
HOWEVER, TSRA ARE EXPECTED TO DEVELOP ALONG SEA BREEZE BOUNDARIES
LATE THIS MORNING AND CONTINUE INTO THE AFTERNOON WITH OUTFLOW
BOUNDARIES INDUCING ADDITIONAL STORMS. SO PLACED VCTS FOR ALL
TERMINALS AFT 18Z WITH THE THREAT PERSISTING FOR SEVERAL HOURS.
KOB
PREV DISCUSSION... /ISSUED 342 AM EDT SUN JUL 19 2015/
DISCUSSION...
DRIER AIR IS MOVING INTO SOUTHEAST FLORIDA ASSOCIATED WITH A
SAHARAN AIR LAYER/SAL. GPS MET DATA SHOWS PW VALUES RANGING FROM
2.2 INCHES AT NAPLES...1.8 AT OKEECHOBEE...AND DOWN TO 1.6 INCHES
AT FT. LAUDERDALE. HEAVY SHOWERS AND TSTORMS HAVE BEEN AFFECTING
THE GULF OVERNIGHT WITH A FEW MOVING ONSHORE THERE. AM EXPECTING
THIS ACTIVITY TO DIMINISH THROUGH DAWN.
THE MODEL TRENDS HAVE TRENDED WITH SLIGHTLY HIGHER POPS FOR THE
EAST COAST. HRRR SHOWS ACTIVITY DEVELOPING ALONG THE ATLANTIC SEA
BREEZE OVER THE METRO AREA AT MID AFTERNOON BEFORE MOVING INLAND.
SO HAVE TRENDED POPS UP A TAD FOR THE EAST COAST...EVEN DESPITE
THE DRYING NOTED. A FEW STRONG TSTORMS WILL BE POSSIBLE THIS
AFTERNOON WITH FREQUENT LIGHTNING AND GUSTY WINDS OF 40-50 MPH THE
PRIMARY THREATS. LOCALES MOST LIKELY TO SEE STRONGER TSTORMS ARE
THE WESTERN SUBURBS OF THE EAST COAST AND THE RURAL INTERIOR.
A WEAKNESS IN THE MID LEVEL RIDGE WILL GET CARVED OUT ON MONDAY
AND CONTINUE THROUGH THE WEEK...WITH TROUGHING DEVELOPING OFF THE
SE U.S. COAST EXTENDING ACROSS FLORIDA ESPECIALLY BY LATE IN THE
WEEK. THE RESULT WILL BE A WIND FLOW PATTERN PREVAILING OUT OF THE
SOUTHWEST. THIS WILL FAVOR THE FOCUS OF TSTORMS EACH DAY ACROSS
THE INTERIOR AND THE EAST COAST METRO AREAS. MOISTURE CONTINUES
LACK LUSTER THOUGH BELOW 700 MB...PREVENTING WIDESPREAD HEAVY
BENEFICIAL RAINS FROM DEVELOPING. /GREGORIA
MARINE...
LIGHT WINDS WILL CONTINUE TO LEAD TO CORRESPONDINGLY LOW SEAS
ACROSS THE SOUTH FL MARINE AREA THROUGH NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 92 76 93 / 20 30 20 40
FORT LAUDERDALE 78 92 78 92 / 20 20 20 30
MIAMI 78 92 78 92 / 20 20 10 30
NAPLES 77 90 78 91 / 20 30 20 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...10/CD
LONG TERM....10/CD
AVIATION...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
952 AM EDT SUN JUL 19 2015
.UPDATE...
MADE SOME MINOR ADJUSTMENTS EARLIER TO ACCOUNT FOR THE LATEST
TRENDS WHICH MAINLY DELAYED TIMING OF THE INITIALIZATION OF
SHOWERS AND STORMS. NO OTHER CHANGES APPEAR TO BE IMMINENT AT THIS
TIME WITH THE 12Z MFL SOUNDING SHOWING THE ATMOSPHERE HAS DRIED
AS PREDICTED WITH THE PWAT FALLING TO 1.66" AND THE MID LEVEL
LAPSE RATES CONTINUE TO BE MEAGER. ALSO, THERE ARE TWO SMALL
INVERSIONS WITH ONE AT 850MB AND THE OTHER AT 700MB ALONG WITH THE
500MB TEMPERATURE WARMED SLIGHTLY. ALL OF THESE COMBINED WILL
RESULT IN A LATER START TO STORM DEVELOPMENT THAN THE PAST COUPLE
OF DAYS AND LESS COVERAGE. HOWEVER, THE LOW LEVEL WIND FIELD ALSO
DECREASED SIGNIFICANTLY SO STORM MOTION WILL BE LESS THAN 5MPH.
THAT BEING SAID, STORMS WILL TEND TO DEVELOP ALONG SEA BREEZE
BOUNDARIES AND THEN SLOWLY MOVE INLAND ALONG THE CONVERGENCE ZONE
BUT AS THESE GROW OUTFLOW BOUNDARIES WILL INDUCE OTHER DEVELOPMENT
SO STORMS COULD JUST ABOUT AFFECT ANYWHERE. THE DRIER AIR ALOFT
COULD ALSO CAUSE THE STRONGER CELLS TO PRODUCE STRONG WIND GUSTS
AND PERHAPS SMALL HAIL. SO ALL THIS BEING SAID, THE HWO LOOKS TO
BE IN GOOD SHAPE AND NO REASON TO CHANGE AT THIS TIME.
KOB
&&
.PREV DISCUSSION... /ISSUED 736 AM EDT SUN JUL 19 2015/
AVIATION...
MOSTLY VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.
HOWEVER, TSRA ARE EXPECTED TO DEVELOP ALONG SEA BREEZE BOUNDARIES
LATE THIS MORNING AND CONTINUE INTO THE AFTERNOON WITH OUTFLOW
BOUNDARIES INDUCING ADDITIONAL STORMS. SO PLACED VCTS FOR ALL
TERMINALS AFT 18Z WITH THE THREAT PERSISTING FOR SEVERAL HOURS.
KOB
PREV DISCUSSION... /ISSUED 342 AM EDT SUN JUL 19 2015/
DISCUSSION...
DRIER AIR IS MOVING INTO SOUTHEAST FLORIDA ASSOCIATED WITH A
SAHARAN AIR LAYER/SAL. GPS MET DATA SHOWS PW VALUES RANGING FROM
2.2 INCHES AT NAPLES...1.8 AT OKEECHOBEE...AND DOWN TO 1.6 INCHES
AT FT. LAUDERDALE. HEAVY SHOWERS AND TSTORMS HAVE BEEN AFFECTING
THE GULF OVERNIGHT WITH A FEW MOVING ONSHORE THERE. AM EXPECTING
THIS ACTIVITY TO DIMINISH THROUGH DAWN.
THE MODEL TRENDS HAVE TRENDED WITH SLIGHTLY HIGHER POPS FOR THE
EAST COAST. HRRR SHOWS ACTIVITY DEVELOPING ALONG THE ATLANTIC SEA
BREEZE OVER THE METRO AREA AT MID AFTERNOON BEFORE MOVING INLAND.
SO HAVE TRENDED POPS UP A TAD FOR THE EAST COAST...EVEN DESPITE
THE DRYING NOTED. A FEW STRONG TSTORMS WILL BE POSSIBLE THIS
AFTERNOON WITH FREQUENT LIGHTNING AND GUSTY WINDS OF 40-50 MPH THE
PRIMARY THREATS. LOCALES MOST LIKELY TO SEE STRONGER TSTORMS ARE
THE WESTERN SUBURBS OF THE EAST COAST AND THE RURAL INTERIOR.
A WEAKNESS IN THE MID LEVEL RIDGE WILL GET CARVED OUT ON MONDAY
AND CONTINUE THROUGH THE WEEK...WITH TROUGHING DEVELOPING OFF THE
SE U.S. COAST EXTENDING ACROSS FLORIDA ESPECIALLY BY LATE IN THE
WEEK. THE RESULT WILL BE A WIND FLOW PATTERN PREVAILING OUT OF THE
SOUTHWEST. THIS WILL FAVOR THE FOCUS OF TSTORMS EACH DAY ACROSS
THE INTERIOR AND THE EAST COAST METRO AREAS. MOISTURE CONTINUES
LACK LUSTER THOUGH BELOW 700 MB...PREVENTING WIDESPREAD HEAVY
BENEFICIAL RAINS FROM DEVELOPING. /GREGORIA
MARINE...
LIGHT WINDS WILL CONTINUE TO LEAD TO CORRESPONDINGLY LOW SEAS
ACROSS THE SOUTH FL MARINE AREA THROUGH NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 92 77 92 76 / 40 20 30 20
FORT LAUDERDALE 91 78 92 78 / 30 20 20 20
MIAMI 91 78 92 78 / 30 20 20 10
NAPLES 91 77 90 78 / 50 20 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
940 AM EDT SUN JUL 19 2015
.DISCUSSION...
.UPDATE...
MORNING SOUNDINGS ACROSS CENTRAL FL INDICATE CONDITIONS SLIGHTLY
DRIER THAN AT THIS TIME YESTERDAY MORNING. PRECIPITABLE WATER VALUES
HAVE DROPPED JUST A BIT TO 1.84-1.88 INCHES AT CAPE CANAVERAL AND
TAMPA BUT STILL ABOVE NORMAL. 915 MHZ CAPE WIND PROFILER INDICATES
SW WINDS AROUND 15 KNOTS FROM JUST OFF THE SFC TO AROUND 6500 FT.
MID LVLS REMAIN WARM WITH H5 TEMPS -5.9 AT XMR AND -5.7 AT TBW AND
8.8-9.2 DEGS C AT 700 MBS. HRRR AND LOCAL WRF MODELS INDICATE
SCATTERED CONVECTION SHOULD MOVE INTO THE INTERIOR FROM THE WEST IN
THE EARLY AFTERNOON AND ALSO DEVELOP ALONG THE EAST COAST SEA BREEZE
BOUNDARY AND PUSH SLOWLY INLAND ACROSS THE COASTAL COUNTIES BY MID
AFTERNOON. SOME LATE AFTERNOON BOUNDARY COLLISIONS ARE AGAIN LIKELY
ACROSS THE ERN HALF OF THE FORECAST AREA WITH SOME HEAVY RAINFALL
AMOUNTS TO 2-3 INCHES IN STRONGER STORMS. MADE SOME SLIGHT
ADJUSTMENTS TO POPS BASED ON CAMS AND SOUNDING DATA WHICH LOWERED
POPS SLIGHTLY SOME AREAS... BUT STILL MAINLY IN THE 50-60 PCT RANGE
FOR THE AFTERNOON HOURS. HIGHS SHOULD REACH THE LOWER 90S MOST
AREAS...EXCEPT THE IMMEDIATE COAST AND BEACHES WITH HIGHS NEAR 90.
&&
.AVIATION...SCATTERED TSRA EXPECTED TO DVLP ACROSS E CENTRAL FL 17Z-
23Z WITH ACTIVITY DEVELOPING FIRST ACROSS THE INTERIOR FROM KLEE-
KISM CORRIDOR AND ALSO ALONG THE EAST COAST SEA BREEZE BY MID AFTN.
ACTIVITY ACROSS THE INTERIOR WILL MOVE NE TWD KSFB-KMCO AND THEN
PROGRESSING BACK TWD THE E COAST IN THE LATE AFTN FROM KDAB-KFPR.
TEMPO MVFR CIGS AND IFR VSBYS WITH +RA CAN BE EXPECTED WITH HEAVIER
SHOWERS AND STRONGER STORMS THIS AFTN.
&&
.MARINE... S-SW WINDS TO 10 KNOTS OFFSHORE AND BECOMING SE ALONG THE
COAST IN THE AFTERNOON. SEAS 1-2 FT NEAR SHORE TO 2-3 FT OFFSHORE.
CHANCE FOR AFTERNOON STORMS ACROSS THE INTRACOASTAL AND NEAR SHORE
ATLANTIC WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 92 75 92 75 / 50 20 50 20
MCO 92 74 92 76 / 60 20 50 20
MLB 91 74 92 75 / 50 30 50 20
VRB 92 72 91 73 / 40 30 60 30
LEE 91 75 91 78 / 50 20 50 20
SFB 92 76 93 77 / 50 20 50 20
ORL 91 76 92 77 / 50 20 50 20
FPR 92 72 91 73 / 40 30 60 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...VOLKMER
IMPACT WEATHER/RADAR....GLITTO
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
348 AM EDT SUN JUL 19 2015
.DISCUSSION...
TODAY-TONIGHT...
STAGNANT WX PATTERN AS THE REMNANTS OF A FRONTAL TROF EXTENDING FROM
THE SERN SEABOARD TO THE NE GOMEX IS TRAPPED BTWN THE ATLC OVER THE
NRN BAHAMAS/S FL AND A CONTINENTAL RIDGE OVER THE DEEP SOUTH. THE
RESULTING DEEP LYR COL OVER THE N FL PENINSULA/ERN PANHANDLE IS
ALLOWING HIGH PWAT AIR TO POOL OVER CENTRAL FL...EVENING RAOBS FROM
KTBW/KXMR MEASURING VALUES BTWN 2.0"-2.1". VALUES DIMINISH TO ARND
1.8" AT KJAX AS A SIGNIFICANTLY DRYER AIR WAS INTRUDING INTO THEIR
COLUMN ABV THE H70 LYR.
THIS DRY AIR HAS SINCE WORKED ITS WAY INTO CENTRAL FL WITH MEAN RH
VALUES THRU THE H50-H10 LYR FALLING TO ARND 30PCT....SCOURING OUT
VIRTUALLY ALL MID/UPR LVL CLOUD COVER ACRS THE FL PENINSULA. TEMPS
ALOFT CONTINUE TO GENERATE WEAK THERMODYNAMIC INSTABILITY...H70
TEMPS ARND 9C AND H50 TEMPS ARND -6C ARE YIELDING LAPSE RATES ARND
5.5C/KM. DYNAMIC SUPPORT IS WEAK AS WELL WITH RAP ANALYSIS
INDICATING ONLY A LOCALIZED H85-H30 VORT AXIS ASSOCD WITH THE DEEP
LYR COL.
ATLC RIDGE AXIS OVER S FL WILL MAINTAIN THE STEADY SW FLOW THRU THE
H100-H70 LYR THAT HAS PREVAILED FOR THE PAST SEVERAL DAYS. THESE
WINDS WILL TAP A SLUG OF SLIGHTLY DRIER AIR LOW/MID LVL AIR OVER THE
NRN BAHAMAS WITH MEAN H100-H70 RH VALUES BLOW 60PCT. THE COMBINATION
OF LOW/MID LVL DRY AIR ADVECTION FROM THE EAST AND MID/UPR LVL DRY
AIR ADVECTION FROM THE N WILL RESULT IN LOWER PRECIP COVERAGE THAN
IN RECENT DAYS...THOUGH STILL IN THE 50-60PCT RANGE WITH PWAT VALUES
EXPECTED TO REMAIN BTWN 1.8"-2.0".
FULL SUN ANTICIPATED OVER CENTRAL FL THRU THE PEAK HEATING HRS...
CONVECTIVE TRIGGERS IN THE U80S/L90S SHOULD BE MET BY MIDDAY WITH
DIURNAL CONVECTION DVLPG SHORTLY THEREAFTER AS THE RAPID SFC
WARMING/DESTABILIZATION OVERWHELMS WHATEVER WEAK THERMAL CAP THE H70
TEMPS MAY INDICATE. POPS DECREASING TO 20-30PCT AFT SUNSET AS THE
EARLY START TO CONVECTION CONSUMES MOST AVAILABLE CAPE BY SUNSET.
LCL HEAVY RAIN WILL ENHANCE FLOODING THREATS...ESPECIALLY IN AREAS
THAT HAVE RECEIVED RECENT HEAVY RAIN.
W/SW FLOW WILL PUSH MAX TEMPS INTO THE L/M90S...SFC DEWPOINTS IN THE
L/M70S WILL KEEP MIN TEMPS ABOUT HALF A CAT HIGHER (M/U70S).
MON-TUE...A STALLED FRONTAL BOUNDARY LYING ALONG THE MID ATLC CST
TO THE FL PANHANDLE WL REMAIN IN PLACE. PRESENCE OF FEATURE WL
KEEP THE SUBTROPICAL RIDGE WELL SOUTH OF THE LCL AREA. SW DLM
FLOW ALONG WITH AMPLE MOISTURE WL LEAD TO DIURNALLY FORCED SCT TO
NMRS SHOWERS AND STORMS. ACTIVITY WL SHIFT OVER THE ATLC WATERS
WHILE DISSIPATING THROUGH THE EVENINGS. STORMS SHOULD BE PARTICULARLY
STRONG WITH OCCASIONAL LIGHTNING AND BRIEF WIND GUSTS THE MAIN
CONCERNS.
EXTENDED...LTST GUID CONTINUES TO POINT TO LITTLE CHG IN THE
PATTERN OVER THE EASTERN CONUS THROUGH LATE WEEK WITH LOWER THAN
NORMAL SFC PRESSURES OVER THE SE TO MID ATLC CST WHERE THE NEARLY
STATIONARY FRONTAL TROUGH RESIDES. SLIGHTLY HIGHER THAN NORMAL
RAIN COVERAGES WL BE ADVERTISED GIVEN THE SUPPRESSION OF THE
SUBTROPICAL RIDGE SOUTH OF CENTRAL FLORIDA AND AMPLE AVAILABLE
MOISTURE.
&&
.AVIATION...THRU 20/12Z
WINDS: THRU 19/14Z...S/SW 4-8KTS. BTWN 19/14Z-19/17Z...S/SW 6-9KTS.
BTWN 19/17Z-19/23Z...COASTAL SITES S/SE 8-12KTS...INTERIOR SITES SW
7-10KTS. BTWN 19/23Z-20/03Z...S/SW 5-8KTS. AFT 20/03Z S/SW AOB 4KTS.
VSBYS/WX/CIGS: BTWN 19/12Z-19/16Z...SLGT CHC MVFR SHRAS ALL SITES.
BTWN 19/16Z-19/24Z...SCT/NMRS MVFR SHRAS/IFR TSRAS ALL SITES...SLGT
CHC LIFR +TSRAS WITH SFC G35KTS.
&&
.MARINE...
TODAY-TONIGHT...ATLC RIDGE AXIS OVER S FL WILL COMBINE WITH A WEAK
FRONTAL TROF OVER N FL TO MAINTAIN A PERSISTENT LIGHT TO GENTLE
S/SWRLY BREEZE OVER THE LCL ATLC...BCMG S/SE NEAR THE COAST IN THE
EARLY AFTN WITH THE FORMATION OF THE EAST COAST SEA BREEZE. SEAS AOB
2FT NEARSHORE AND 2-3FT OFFSHORE. SCT/NMRS SHRAS/TSRAS MVG OFFSHORE
BTWN NOON AND SUNSET.
RIDGE POSITIONING FORECAST SOUTH OF THE CENTRAL FL COAST THROUGH
THE WEEK WL LEAD TO FAVORABLE MARINE CONDS DUE TO PREVAILING
OFFSHORE WIND COMPONENT. SEAS AROUND 1-2 FT NEAR THE COAST AND
LESS THAN 4 FT WELL BEYOND 20 NM. LOCALLY HIGHER WINDS AND SEAS AT
MID TO LATE AFTERNOON NEAR THE IMMEDIATE COAST DUE TO OFFSHORE
MOVING STORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 90 75 92 75 / 60 20 50 20
MCO 92 74 92 76 / 60 20 50 20
MLB 90 74 92 75 / 60 30 50 20
VRB 92 72 91 73 / 50 30 60 30
LEE 91 75 91 78 / 60 20 50 20
SFB 93 76 93 77 / 60 20 50 20
ORL 92 76 92 77 / 60 20 50 20
FPR 91 72 91 73 / 50 30 60 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...BRAGAW
LONG TERM....PENDERGRAST
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
347 AM EDT SUN JUL 19 2015
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOW THAT THE UPPER LEVEL
PATTERN OVER THE SOUTHERN TIER OF THE COUNTY HAS CHANGED LITTLE IN
THE PAST 24 HOURS. A LARGE WEST TO EAST ORIENTED UPPER RIDGE
REMAIN IN PLACE OVER THE SOUTHERN PLAINS AND DEEP SOUTH STATES.
THE FLORIDA PENINSULA ALSO REMAINS ON THE FAR EASTERN PERIPHERY
OF THIS RIDGE CIRCULATION. THE FLOW ALOFT WITHIN THIS CIRCULATION
IS FROM THE NORTHEAST...AND THIS WAS SAMPLED WELL ABOVE 500MB IN
THE KTBW 19/00Z SOUNDING PROFILE. FURTHER DOWN THE COLUMN THE FLOW
REVERSES ITSELF...BLOWING FROM THE SOUTHWEST BELOW 700MB. THIS
LOWER LEVEL FLOW RESULTS FROM THE GRADIENT BETWEEN A WEAK SURFACE
TROUGH TO OUR NORTH...AND THE SUBTROPICAL SURFACE RIDGE ACROSS
SOUTH FLORIDA/SE GULF OF MEXICO.
THE COLUMN REMAINS FAIRLY MOIST WITH A PW VALUE SAMPLED LAST
EVENING AT JUST OVER 2". HOWEVER...LOOKING TO THE NORTH WE SEE A
DRIER COLUMN AT KJAX OF 1.86"...AND A MUCH DRIER PROFILE AT KTLH
OF 1.36". WITH FLOW ALOFT FROM THE NORTHEAST IT WOULD SUGGEST SOME
OF THIS DRIER AIR WILL BE ADVECTING SOUTHWARD INTO OUR AREA DURING
TODAY. IN FACT...THIS IS EXACTLY WHAT THE ENSEMBLE GUIDANCE
SUGGEST...WITH A FAIRLY DRY LAYER BETWEEN 700-500MB DRIFTING DOWN
OVER OUR NATURE COAST ZONES. THE ATMOSPHERE IS NOT GOING TO GET
DRY ENOUGH TO PREVENT SHOWERS...BUT SHOULD HELP LESSEN THE
POTENTIAL FOR SIGNIFICANT RAIN TOTALS OVER THE NORTHERN ZONES.
WEAK LAND BREEZE HAS DEVELOPED EARLY THIS MORNING AND IS
SUPPORTING A SCATTERING OF SHOWERS/STORMS OVER THE COASTAL WATERS.
THIS CONVECTION BRIEFLY IMPACTED AREAS AROUND CHARLOTTE
HARBOR...BUT HAS SINCE DRIFTED EASTWARD...AND CURRENTLY LOOKING AT
QUIET AND GENERALLY DRY CONDITIONS OVER THE LANDMASS.
&&
.SHORT TERM (TODAY THROUGH MONDAY)...
TODAY... SYNOPTIC PATTERN IS KIND OF A BROKEN RECORD. OTHER THAN
THE SLIGHTLY DRIER AIR ALOFT ARRIVING OVER THE NATURE COAST
TODAY...THINGS ARE SIMILAR TO PREVIOUS DAYS. SCT SHOWERS AND A FEW
THUNDERSTORMS ARE EXPECTED OVER THE EASTERN GULF EARLY THIS
MORNING AND THEN SLOWLY MIGRATING TOWARD THE COAST TOWARD DAWN
AND/OR INTO THE MORNING DAYLIGHT HOURS. BASED ON THE LAND-BREEZE
NOW FORMED...WILL NOT BE GOING WITH LIKELY POPS ALONG THE
COAST...BUT RATHER CAP THINGS IN THE 40-50% RANGE...AND PUSH THE
TIMING BACK. MAY NEED TO LET THE LAND HEAT UP A BIT AND WEAKEN THE
LAND BREEZE BEFORE THE SYNOPTIC SOUTHWEST FLOW CAN BECOME RE-
ESTABLISHED AND SHOWERS COMMENCE AGAIN ON LAND.
OVER TIME TODAY WILL MIGRATE THE HIGHER POPS (40-50%) INLAND...AND
RAMP DOWN THE RAIN CHANCES CLOSE TO THE COAST THE FURTHER INTO THE
AFTERNOON WE PROGRESS. LOOKING AT THE FORECAST SOUNDINGS...NOT
REALLY ANTICIPATING MUCH IN THE WAY OF STRONG STORMS TODAY...
ALTHOUGH FREQUENT LIGHTING CAN ALWAYS BE DANGEROUS. BETTER CHANCES
FOR ANY GUSTY WINDS WITH STORMS WOULD GENERALLY BE NORTH OF I-4
WHERE THE DRIER AIR ALOFT HELPS EVAPORATIVE COOLING WITHIN ANY
CONVECTIVE COLUMNS.
HIGH TEMPERATURE NEAR NORMAL TODAY...WITHIN A DEGREE OR TWO
EITHER SIDE OF 90 FOR MOST SPOTS.
TONIGHT...
SCT EVENING CONVECTION (MAINLY INLAND) FADES AND LEAVES THE
LANDMASS GENERALLY DRY FOR A WHILE INTO THE EARLY MORNING HOURS.
HIRES LOCAL WRFARW RUNS ARE SHOWING ANOTHER LAND BREEZE
CIRCULATION DEVELOPING AFTER MIDNIGHT FROM TAMPA BAY
SOUTHWARD...WHICH SHOULD PROMOTE SCT CONVECTION OVER THE NEARSHORE
WATERS THE SECOND HALF OF THE NIGHT. TOWARD DAWN AND INTO THE
FIRST FEW DAYLIGHT HOURS...THIS LAND BREEZE WILL FADE...AND AGAIN
WILL BEGIN TO SEE ISOLATED SHOWERS MIGRATE TOWARD THE COAST.
FURTHER NORTH ALONG THE NATURE COAST...A SLIGHTLY TIGHTER GRADIENT
IN CLOSER PROXIMITY TO A WEAK FRONTAL BOUNDARY TO OUR NORTH SHOULD
PREVENT A LAND BREEZE...AND KEEP A SYNOPTIC SOUTHWEST FLOW IN
PLACE. ENSEMBLE GUIDANCE SUGGEST THAT THE BEST CHANCES FOR SCT
PRE- DAWN SHOWERS REACHING THE COAST WILL BE NORTH OF PASCO COUNTY
WITHIN THIS FAVORABLE AND MOIST SOUTHWEST LOW LEVEL FLOW.
MONDAY...
GUESS WHAT? SOUTHWEST LOW LEVEL FLOW PROMOTING MORNING SHOWER
NEAR THE COAST...MIGRATING INLAND AND EXPANDING WITH DIURNAL
INSTABILITY. FORECAST WILL AGAIN SHOW CHANCE POPS ALONG THE COAST
THE FIRST HALF OF THE DAY...AND THEN THESE CHANCE POPS SHIFTING
EAST OF THE I-75 CORRIDOR DURING THE AFTERNOON. ONLY EXCEPTION
MADE TO THIS REPEATING PATTERN WITH THIS FORECAST CYCLE WAS TO
KEEP HIGHER RAIN CHANCES UP TOWARD LEVY COUNTY THROUGH THE
AFTERNOON. MANY RELIABLE GUIDANCE MEMBERS SHOW ENHANCED LOW LEVEL
CONVERGENCE ACROSS THE BIG BEND REGION REACHING DOWN TO JUST ABOUT
THE MOUTH OF THE SUWANNEE. MAY BE ABLE TO LOWER THESE AFTERNOON
POPS FOR LEVY COUNTY LATER IF FUTURE GUIDANCE RUNS LIFT THE BETTER
FOCUS REGION TO THE NORTH. HIGH TEMPERATURES AGAIN WITH A DEGREE
OR TWO EITHER SIDE OF 90.
HAVE A GREAT SUNDAY EVERYONE!
&&
.LONG TERM (MONDAY NIGHT - SATURDAY)...
AT THE START OF THE LONG TERM PERIOD...BROAD UPPER LEVEL RIDGING
WILL BE ENTRENCHED OVER THE GULF COAST AND SOUTHERN
PLAINS...ISOLATING THE FLORIDA PENINSULA FROM THE EFFECTS OF THE JET
STREAM SNAKING THROUGH THE NORTHERN HALF OF THE CONUS. AT THE
SURFACE...THE SUBTROPICAL RIDGE AXIS WILL REMAIN SOUTH OF THE
FORECAST AREA...KEEPING THE REGION UNDER THE INFLUENCE OF
SOUTHWESTERLY FLOW. THIS PATTERN...WHICH HAS ALREADY BEEN IN PLACE
FOR A FEW DAYS NOW...TENDS TO PRODUCE SHOWERS AND THUNDERSTORMS
DEVELOPING OVER THE EASTERN GULF OF MEXICO DURING THE OVERNIGHT AND
MORNING HOURS...WITH STORMS MOVING ONSHORE THROUGH THE DAYLIGHT
HOURS. TYPICALLY THE AREAS ALONG THE COAST SEE HIGHER RAIN CHANCES
DURING THE MORNING AND EARLY AFTERNOON HOURS...WITH THE INTERIOR
FILLING IN DURING THE AFTERNOON AND EARLY EVENING. THIS PATTERN WILL
REMAIN LARGELY UNCHANGED UNTIL LATE IN THE WEEK...WHEN THE UPPER
LEVEL RIDGE SHIFTS WEST INTO THE PLAINS ALLOWING A MID LEVEL TROUGH
TO DIG IN TOWARDS FLORIDA. THIS COULD INCREASE RAIN CHANCES EVEN
FURTHER AS THE TROUGH PASSES NEARBY...BUT THERE IS STILL A LOT OF
UNCERTAINTY BECAUSE OF HOW FAR OUT IN TIME THIS FEATURE IS.
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS THE REGION EARLY THIS MORNING. NOT
ANTICIPATING ANY SIGNIFICANT AVIATION CONCERNS THROUGH THE TAF
PERIOD. ANY RESTRICTIONS WILL COME FROM SCT SHOWER
ACTIVITY...MAINLY DURING THE DAYLIGHT HOURS...AND WILL GENERALLY
BE BRIEF IN NATURE.
&&
.MARINE...
A WEAK GRADIENT BETWEEN A SURFACE TROUGH TO OUR NORTH AND THE
SUBTROPICAL SURFACE RIDGE TO OUR SOUTH WILL KEEP A GENERAL LARGE
SCALE SOUTHWEST FLOW IN PLACE OVER THE FORECAST WATERS THE NEXT
SEVERAL DAYS. WHERE THE GRADIENT IS WEAKEST TO THE SOUTH OF
TARPON SPRINGS...THE FLOW IS LIKELY TO SHIFT OFFSHORE EARLY EACH
MORNING AS A LAND BREEZE DEVELOPS. HOWEVER...EXPECT WINDS TO
RETURN TO A SOUTHWEST DIRECTION WITHIN A FEW HOURS AFTER SUNRISE
EACH MORNING. SCATTERED SHOWERS/STORMS WILL REMAIN IN THE
FORECAST...MAINLY DURING THE LATE NIGHT AND MORNING HOURS.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS THROUGH THE EARLY PORTION OF
THE WEEK EXPECTED. MOIST SOUTHWEST FLOW WILL KEEP RELATIVE
HUMIDITY VALUES WELL ABOVE CRITICAL LEVELS.
FOG POTENTIAL...NO SIGNIFICANT AREAS OF FOG EXPECTED THROUGH THE
EARLY PORTION OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 90 79 90 79 / 40 30 40 30
FMY 91 76 91 77 / 40 30 40 30
GIF 92 76 91 76 / 50 30 50 20
SRQ 88 78 88 79 / 50 30 40 30
BKV 90 74 90 75 / 30 20 40 30
SPG 88 79 89 79 / 40 30 40 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WEATHER...14/MROCZKA
LONG TERM/DECISION SUPPORT...18/FLEMING
AREA FORECAST DISCUSSION
NWS MIAMI FL
342 AM EDT SUN JUL 19 2015
.DISCUSSION...
DRIER AIR IS MOVING INTO SOUTHEAST FLORIDA ASSOCIATED WITH A
SAHARAN AIR LAYER/SAL. GPS MET DATA SHOWS PW VALUES RANGING FROM
2.2 INCHES AT NAPLES...1.8 AT OKEECHOBEE...AND DOWN TO 1.6 INCHES
AT FT. LAUDERDALE. HEAVY SHOWERS AND TSTORMS HAVE BEEN AFFECTING
THE GULF OVERNIGHT WITH A FEW MOVING ONSHORE THERE. AM EXPECTING
THIS ACTIVITY TO DIMINISH THROUGH DAWN.
THE MODEL TRENDS HAVE TRENDED WITH SLIGHTLY HIGHER POPS FOR THE
EAST COAST. HRRR SHOWS ACTIVITY DEVELOPING ALONG THE ATLANTIC SEA
BREEZE OVER THE METRO AREA AT MID AFTERNOON BEFORE MOVING INLAND.
SO HAVE TRENDED POPS UP A TAD FOR THE EAST COAST...EVEN DESPITE
THE DRYING NOTED. A FEW STRONG TSTORMS WILL BE POSSIBLE THIS
AFTERNOON WITH FREQUENT LIGHTNING AND GUSTY WINDS OF 40-50 MPH THE
PRIMARY THREATS. LOCALES MOST LIKELY TO SEE STRONGER TSTORMS ARE
THE WESTERN SUBURBS OF THE EAST COAST AND THE RURAL INTERIOR.
A WEAKNESS IN THE MID LEVEL RIDGE WILL GET CARVED OUT ON MONDAY
AND CONTINUE THROUGH THE WEEK...WITH TROUGHING DEVELOPING OFF THE
SE U.S. COAST EXTENDING ACROSS FLORIDA ESPECIALLY BY LATE IN THE
WEEK. THE RESULT WILL BE A WIND FLOW PATTERN PREVAILING OUT OF THE
SOUTHWEST. THIS WILL FAVOR THE FOCUS OF TSTORMS EACH DAY ACROSS
THE INTERIOR AND THE EAST COAST METRO AREAS. MOISTURE CONTINUES
LACK LUSTER THOUGH BELOW 700 MB...PREVENTING WIDESPREAD HEAVY
BENEFICIAL RAINS FROM DEVELOPING. /GREGORIA
&&
.MARINE...
LIGHT WINDS WILL CONTINUE TO LEAD TO CORRESPONDINGLY LOW SEAS
ACROSS THE SOUTH FL MARINE AREA THROUGH NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 92 77 92 76 / 40 20 30 20
FORT LAUDERDALE 91 78 92 78 / 30 20 20 20
MIAMI 91 78 92 78 / 30 20 20 10
NAPLES 91 77 90 78 / 50 20 30 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
103 PM EDT SUN JUL 19 2015
.PREV DISCUSSION... /ISSUED 947 AM EDT SUN JUL 19 2015/
UPDATE...
LATEST GFS AND RAP SHOW H5 SHORT WAVE OVER EASTERN TN WILL MOVE
ACROSS THE CWA THIS AFTERNOON. LATEST HI-RES RADAR MODELS SHOWS
RAPID DEVELOPMENT ACROSS THE ENTIRE CWA THIS AFTERNOON. WILL
THEREFORE INCREASE POPS THIS AFTERNOON. NO OTHER CHANGES PLANNED.
PREV DISCUSSION... /ISSUED 402 AM EDT SUN JUL 19 2015/
SHORT TERM /TODAY THROUGH MONDAY/...
NO BIG CHANGE IN THE OVERALL PATTERN FOR THE SHORT TERM. EASTERN
EDGE OF THE UPPER RIDGE CENTERED OVER THE LOWER MS VALLEY WILL
CONTINUE TO DOMINATE OUR AREA. ALSO A WEAK SURFACE BOUNDARY LINGERS
ACROSS CENTRAL GA. THERE MAY BE OUTFLOW BOUNDARIES FROM CONVECTIVE
COMPLEXES MOVING FROM THE OH VALLEY INTO THE APPALACHIANS...BUT
GENERALLY THERE IS LITTLE TO FOCUS ON FOR A FAVORED AREA FOR
CONVECTION. HAVE CONTINUED AGAIN WITH A BROAD AREA OF CHANCE POPS
AREA WIDE FOR THIS AFTERNOON AND AGAIN MONDAY. THIS MAY BE A BIT
OVERDONE FOR MUCH OF THE FORECAST AREA.
EXPECTING CONTINUED HOT WEATHER TODAY AND AGAIN MONDAY. FOR THIS
AFTERNOON THERE ARE AREAS ACROSS CENTRAL GA THAT REACH HEAT INDEX OF
105 TO 107. SO AN ADVISORY HAS BEEN ISSUED FOR THAT PORTION OF THE
AREA ALONG AND SOUTH OF A LINE FROM LA GRANGE TO MILLEDGEVILLE TO
WARRENTON.
41
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
LONG TERM MODELS IN FAIRLY GOOD AGREEMENT...THE UPPER LEVEL RIDGE
FLATTENS AND RETREATS WESTWARD. AT THE SURFACE...A WEAK BOUNDARY
IS NOTED TRAVERSING THE FORECAST AREA TUESDAY INTO
WEDNESDAY...BOTH GFS/ECMWF SHOWS THE THICKNESS VALUES LOWERING
ACROSS NORTH GEORGIA...TEMPERATURES STILL PROGGED IN THE LOWER TO
MID 90S. PROXIMITY OF BOUNDARY AND WEAK UPPER LEVEL VORT MAXES
WILL AID IN DEVELOPMENT OF AFTERNOON AND EVENING CONVECTION WITH
SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED EACH DAY.
ATWELL
41
&&
.AVIATION...
18Z UPDATE...
CONVECTION HAS INITIATED ACROSS NORTH GA AND SHOULD SPREAD INTO
CENTRAL GA OVER THE AFTERNOON HOURS. ALL CONVECTION SHOULD
DISSIPATE AFTER SUNSET. OTHER THAN IN TSRA...VFR CONDITIONS SHOULD
PERSIST THROUGH THE FORECAST. WINDS WILL REMAIN WEST TO NORTHWEST
THROUGH THE FORECAST...GOING CALM OR NEAR CALM TONIGHT.
//ATL CONFIDENCE...18Z UPDATE...
HIGH ON ALL ELEMENTS
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 96 75 98 75 / 50 50 40 40
ATLANTA 93 76 94 77 / 50 50 40 40
BLAIRSVILLE 88 68 90 69 / 50 50 40 40
CARTERSVILLE 94 73 95 74 / 50 50 40 40
COLUMBUS 97 77 97 77 / 50 50 40 40
GAINESVILLE 93 75 94 76 / 50 50 40 40
MACON 98 74 98 75 / 50 50 40 40
ROME 95 73 97 74 / 50 50 40 40
PEACHTREE CITY 94 74 94 74 / 50 50 40 40
VIDALIA 97 75 97 77 / 50 50 40 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR THE FOLLOWING
ZONES: BALDWIN...BIBB...BLECKLEY...CHATTAHOOCHEE...CRAWFORD...
CRISP...DODGE...DOOLY...EMANUEL...GLASCOCK...HANCOCK...HARRIS...
HOUSTON...JEFFERSON...JOHNSON...JONES...LAMAR...LAURENS...
MACON...MARION...MERIWETHER...MONROE...MONTGOMERY...MUSCOGEE...
PEACH...PIKE...PULASKI...SCHLEY...STEWART...SUMTER...TALBOT...
TAYLOR...TELFAIR...TOOMBS...TREUTLEN...TROUP...TWIGGS...UPSON...
WARREN...WASHINGTON...WEBSTER...WHEELER...WILCOX...WILKINSON.
&&
$$
SHORT TERM...17
LONG TERM....20
AVIATION...17
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
947 AM EDT SUN JUL 19 2015
.UPDATE...
LATEST GFS AND RAP SHOW H5 SHORT WAVE OVER EASTERN TN WILL MOVE
ACROSS THE CWA THIS AFTERNOON. LATEST HI-RES RADAR MODELS SHOWS
RAPID DEVELOPMENT ACROSS THE ENTIRE CWA THIS AFTERNOON. WILL
THEREFORE INCREASE POPS THIS AFTERNOON. NO OTHER CHANGES PLANNED.
&&
.PREV DISCUSSION... /ISSUED 402 AM EDT SUN JUL 19 2015/
SHORT TERM /TODAY THROUGH MONDAY/...
NO BIG CHANGE IN THE OVERALL PATTERN FOR THE SHORT TERM. EASTERN
EDGE OF THE UPPER RIDGE CENTERED OVER THE LOWER MS VALLEY WILL
CONTINUE TO DOMINATE OUR AREA. ALSO A WEAK SURFACE BOUNDARY LINGERS
ACROSS CENTRAL GA. THERE MAY BE OUTFLOW BOUNDARIES FROM CONVECTIVE
COMPLEXES MOVING FROM THE OH VALLEY INTO THE APPALACHIANS...BUT
GENERALLY THERE IS LITTLE TO FOCUS ON FOR A FAVORED AREA FOR
CONVECTION. HAVE CONTINUED AGAIN WITH A BROAD AREA OF CHANCE POPS
AREA WIDE FOR THIS AFTERNOON AND AGAIN MONDAY. THIS MAY BE A BIT
OVERDONE FOR MUCH OF THE FORECAST AREA.
EXPECTING CONTINUED HOT WEATHER TODAY AND AGAIN MONDAY. FOR THIS
AFTERNOON THERE ARE AREAS ACROSS CENTRAL GA THAT REACH HEAT INDEX OF
105 TO 107. SO AN ADVISORY HAS BEEN ISSUED FOR THAT PORTION OF THE
AREA ALONG AND SOUTH OF A LINE FROM LA GRANGE TO MILLEDGEVILLE TO
WARRENTON.
41
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
LONG TERM MODELS IN FAIRLY GOOD AGREEMENT...THE UPPER LEVEL RIDGE
FLATTENS AND RETREATS WESTWARD. AT THE SURFACE...A WEAK BOUNDARY
IS NOTED TRAVERSING THE FORECAST AREA TUESDAY INTO
WEDNESDAY...BOTH GFS/ECMWF SHOWS THE THICKNESS VALUES LOWERING
ACROSS NORTH GEORGIA...TEMPERATURES STILL PROGGED IN THE LOWER TO
MID 90S. PROXIMITY OF BOUNDARY AND WEAK UPPER LEVEL VORT MAXES
WILL AID IN DEVELOPMENT OF AFTERNOON AND EVENING CONVECTION WITH
SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED EACH DAY.
ATWELL
AVIATION...
12Z UPDATE...
DIURNAL CUMULUS AND SCATTERED CONVECTION EXPECTED AGAIN THIS
AFTERNOON. CHANCE OF THUNDERSTORMS TOO SMALL TO INCLUDE IN TAFS AT
THIS TIME. WINDS LIGHT AND VARIABLE UNTIL BECOMING WEST TO
NORTHWEST AFTER 14Z.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE WITH LOCATION OF CONVECTION. HIGH CONFIDENCE REMAINING
ELEMENTS.
41
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 96 75 98 75 / 30 20 30 20
ATLANTA 93 76 94 77 / 30 20 30 20
BLAIRSVILLE 88 68 90 69 / 30 20 30 20
CARTERSVILLE 94 73 95 74 / 30 20 30 20
COLUMBUS 97 77 97 77 / 30 20 30 20
GAINESVILLE 93 75 94 76 / 30 20 30 20
MACON 98 74 98 75 / 30 20 30 20
ROME 95 73 97 74 / 30 20 30 20
PEACHTREE CITY 94 74 94 74 / 30 20 30 20
VIDALIA 97 75 97 77 / 30 20 40 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EDT THIS EVENING
FOR THE FOLLOWING ZONES: BALDWIN...BIBB...BLECKLEY...
CHATTAHOOCHEE...CRAWFORD...CRISP...DODGE...DOOLY...EMANUEL...
GLASCOCK...HANCOCK...HARRIS...HOUSTON...JEFFERSON...JOHNSON...
JONES...LAMAR...LAURENS...MACON...MARION...MERIWETHER...MONROE...
MONTGOMERY...MUSCOGEE...PEACH...PIKE...PULASKI...SCHLEY...
STEWART...SUMTER...TALBOT...TAYLOR...TELFAIR...TOOMBS...
TREUTLEN...TROUP...TWIGGS...UPSON...WARREN...WASHINGTON...
WEBSTER...WHEELER...WILCOX...WILKINSON.
&&
$$
SHORT TERM...17
LONG TERM....20
AVIATION...17
AREA FORECAST DISCUSSION
NWS POCATELLO ID
318 AM MDT SUN JUL 19 2015
.DISCUSSION...WEAK POSITIVE TILT TROUGH REMAINS OVERHEAD TODAY.
SFC DEWPOINTS STILL IN THE 40S ACROSS MOST OF THE REGION...WHICH
MAY BE MOIST ENOUGH TO SEE VERY ISOLATED POCKETS OF CONVECTION
THIS AFTN/EVE. GFS/NAM AND RAP ALL PINPOINT THE LEE EDGE OF THE
CENTRAL MTNS TOWARD THE DIVIDE THIS AFTERNOON THOUGH THE GFS AND
NAM ALSO PICKING UP ON POCKET OF MOISTURE NEAR THE UTAH/NEVADA
BORDER REGION AS WELL. MAY NOT BE AGGRESSIVE ENOUGH WITH POPS FOR
DAYTIME PERIOD TODAY. MODELS SHIFT WEAK SHORTWAVE EAST ACROSS EAST
IDAHO OVERNIGHT AND GFS MAINTAINS NOCTURNAL CONVECTION ABOVE DRY
NAM...STRENGTHENING CONVECTION INTO EARLY MONDAY MORNING. OPTED TO
STAY DRY GIVEN STRONG DIFFERENCES IN MODELS BUT AGAIN COULD BE TOO
WEAK ON POPS. MEANWHILE...STRONGER SHORTWAVE TROUGH DROPPING INTO
PACNW MONDAY/MONDAY NIGHT WITH MOISTURE FROM REMNANTS OF TS
DOLORES WORKING THROUGH CALIFORNIA AND INTO THE GREAT BASIN TO
MERGE WITH NORTHERN STREAM FEATURE. NAM AND GFS APPEAR TO BE ON
THE SAME PAGE WITH PULLING BULK OF DOLORES MOISTURE THROUGH GREAT
BASIN TUESDAY NIGHT. UPTICK IN CONVECTION OCCURS TUESDAY AFTERNOON
BUT PRECIP BECOMES MORE WIDESPREAD WEDNESDAY. GFS AND ECMWF BOTH
ON BOARD WITH MAINTAINING CONVECTION OVERNIGHT AND CONTINUING
AGAIN ON THURSDAY. SOME DIFFERENCES BETWEEN GFS AND ECMWF ON
AMPLITUDE OF TROUGH ALONG COAST. GFS SHARPER WITH TROUGH LEADING
TO SLIGHTLY SLOWER SOLUTION THROUGH FRIDAY AND CONTINUED THREAT OF
PRECIP. ECMWF A LITTLE MORE SHALLOW AND WESTERLY INFLUENCE PUSHES
MOISTURE OUT OF THE REGION FOR A DRIER SOLUTION. BOTH SOLUTIONS
SLOWLY BUILD RIDGE OVER 4-CORNERS/ROCKIES INTO THE WEEKEND FOR DRY
AND WARMER CONDITIONS. DMH
&&
.AVIATION...UPPER LEVEL TROUGH WILL GRADUALLY WEAKEN AS IT
PROGRESSES EAST OF THE AREA THROUGH THE DAY TODAY...AS THE UPPER
LEVEL FLOW TRANSITIONS TO A DRIER WESTERLY ONE. THEREFORE ONLY A
SLIGHT CHANCE OF A SHOWER IN THE 21-03Z TIME FRAME AS SUN...BUT
CHANCES TOO LOW TO INCLUDE IN TAF ATTM. OTHERWISE DRY CONDITIONS
WITH VFR EXPECTED THROUGH THE FORECAST PERIOD AT ALL TERMINALS WITH
GENERALLY LIGHT WINDS UNDER 12 KNOTS. AD/DMH
&&
.FIRE WEATHER...AN UPPER LEVEL TROUGH WILL GRADUALLY SHIFT EAST OF
THE AREA TODAY ALLOWING FOR A DRIER WESTERLY FLOW TO TAKE HOLD IN
THE UPPER LEVELS. AS A RESULT...TEMPERATURES WILL WARM TO JUST BELOW
SEASONAL NORMALS TODAY...AND TO AROUND SEASONAL NORMALS FOR MONDAY
AND TUESDAY. A CORRESPONDING DRYING TREND WILL OCCUR IN TERMS OF
HUMIDITIES AS WELL. GENERALLY LIGHT TERRAIN INDUCED WINDS EXPECTED
TODAY AND MONDAY WITH SOME AFTERNOON SOUTHWESTERLY GUSTS IN THE 15-
20 MPH RANGE POSSIBLE ACROSS THE ARCO DESERT TUESDAY PM. IMPACTS
FROM THE NEXT DISTURBANCE WILL BEGIN TO BE NOTICED BY TUESDAY
AFTERNOON AND EVENING IN THE FORM OF A FEW SHOWERS AND THUNDERSTORMS
OVER THE CENTRAL MOUNTAINS AND SOUTHEAST HIGHLANDS. SHOWER AND
THUNDERSTORM ACTIVITY IS THEN EXPECTED TO INCREASE FURTHER IN
COVERAGE ON WEDNESDAY AND THURSDAY WITH SHOWERS AND THUNDERSTORMS
POSSIBLE AREA WIDE...ALONG WITH A CORRESPONDING DECREASE IN
TEMPERATURES AND INCREASE IN HUMIDITY. THESE VALUES SHOULD APPROACH
WHAT WAS EXPERIENCED ACROSS THE AREA OVER THE LAST TWO DAYS. A
DRYING AND WARMING TREND IS THEN ANTICIPATED BY THURSDAY AND FRIDAY.
AD/DMH
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1010 PM CDT MON JUL 20 2015
.SHORT TERM...
230 PM CDT
THROUGH TONIGHT...
A SHORT WAVE TROUGH AXIS ORIENTED FROM SOUTHWEST WISCONSIN THROUGH
FAR WESTERN ILLINOIS AS OF 230 PM WILL MOVE OVER THE FORECAST
AREA LATE THIS AFTERNOON. A PATCH OF CLEARING HAS ALLOWED
TEMPERATURES TO REACH MID 80S WITH A FEW UPPER 80S ATTAINED IN
EASTERN AREAS. THESE ARE AT CONVECTIVE VALUES GIVEN THE DEW POINTS
AND ACCORDINGLY SOME CUMULUS...A FEW TOWERING...HAVE DEVELOPED IN
THE AREA. LAPSE RATES ABOVE THE LFC REMAIN NON-IMPRESSIVE PER
AMDAR AND RAP ANALYSIS SO WHILE SOME SHOWERS MAY DEVELOP/INCREASE
IN COVERAGE WITH THIS IMPULSE AS IT MOVES EAST...THUNDER MAY STILL
BE HARD TO COME BY.
A SURFACE COLD FRONT EXTENDING FROM A LOW AT THE SOUTHERN TIP OF
JAMES BAY IN CANADA WILL MOVE SOUTHEAST THROUGH THE AREA THIS
EVENING...BASICALLY RIGHT IN THE WAKE OF THE AFOREMENTIONED SHORT
WAVE TROUGH. THE AIR MASS AHEAD OF THE FRONT IN WISCONSIN TO
EASTERN IOWA HAS STRUGGLED TO DESTABILIZE GIVEN CLOUD COVER...BUT
A FEW STORMS ARE STARTING TO POP AS THAT MOVES EAST. SCATTERED
SHOWERS AND A FEW STORMS SHOULD DEVELOP IMMEDIATELY UPSTREAM AND
SOME ARE ANTICIPATED TO PROGRESS INTO THE CWA BETWEEN 6 AND 9 PM.
COVERAGE SHOULD REMAIN SCATTERED. AS NOTED EARLIER...THE SOMEWHAT
LIMITED INSTABILITY SHOULD KEEP COVERAGE 30-50 PERCENT ALONG THE
BOUNDARY. WHILE SOME 35 MPH PLUS GUSTS MAY ACCOMPANY A FEW STORMS
GIVEN MARGINAL EFFECTIVE DEEP LAYER SHEAR AND 700-1000 J/KG OF
DCAPE...THE ATMOSPHERE REMAINS NON-CONDUCIVE FOR SEVERE STORMS.
THE FOCUS FOR SHOWERS SHOULD CLEAR THE CWA BY MIDNIGHT WITH
CLOUDS QUICKLY CLEARING AS WELL. A SECONDARY MOMENTUM PUSH OF THE
DRIER AIR MASS SHOULD ARRIVE LATE ON NORTHERLY WINDS...WITH LOW
TEMPERATURES BY DAYBREAK NEAR NORMAL.
MTF
&&
.LONG TERM...
328 PM CDT
TUESDAY THROUGH MONDAY...
NO SIGNIFICANT WEATHER CONCERNS FOR ONE OF THE FEW TIMES THIS
METEOROLOGICAL SUMMER. SURFACE HIGH PRESSURE REMAINING NEARLY
STATIONARY OVER THE REGION SHOULD KEEP THINGS DRY THROUGH
FRIDAY. EXPECTING DAILY LAKE BREEZE FORMATION THROUGH AT LEAST
THURSDAY. 12Z NAM DID HAVE A FEW PERIODS WITH CONVECTION FORECAST
TO POP ON LAKE BREEZE...WEDNESDAY EVENING AND THURSDAY
AFTERNOON...THOUGH DEWPOINTS SEEM TO BE HIGH BIASED EVEN WITH VERY
WET SUMMER SO FAR. THUS THINKING IS INSTABILITY WILL REMAIN
MINIMAL EVEN WITH A FEW UPPER DISTURBANCES MOVING OVER THE AREA
LATE WEDNESDAY AND AGAIN ON THURSDAY...COUPLING WITH DRY COLUMN TO
ENABLE DRY CONDITIONS TO PREVAIL. CANNOT COMPLETELY RULE OUT A
FEW ISOLATED SHOWERS BEING SQUEEZED OUT ON THURSDAY GIVEN STRONGER
VORT MAX.
TEMPERATURES ON TUESDAY SHOULD REACH AROUND 80 INLAND
BASED ON 925 MB TEMPS IN THE UPPER TEENS CELSIUS AND FAIRLY DEEP
MIXING. THEN EXPECT GRADUAL WARMING THE REST OF THE WEEK INTO THE
WEEKEND DUE TO RISING HEIGHTS FROM SOUTHERN CONUS MID/UPPER RIDGE.
GUIDANCE HAS OFTEN VERIFIED TOO HIGH THIS SUMMER WITH TEMPS...BUT
WONDER IF PROGGED THERMAL PROFILES MAY BE SUPPORTIVE OF A BIT
WARMER THAN FORECAST LOWER 80S ON WEDNESDAY AND THURSDAY AND LOWER
TO MID 80S ON FRIDAY SINCE THERE WILL LIKELY NOT BE CONVECTIVE
DEBRIS CLOUD COVER TO CONTEND WITH. DOES APPEAR A BIT BETTER
CHANCE FOR MID AND HIGH CLOUDS ON THURSDAY THOUGH AFTER A FEW TO
SCT CU ON WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE NORTHWEST
ON FRIDAY NIGHT AND THEN MOVE ACROSS THE AREA ON
SATURDAY...BRINGING A THREAT FOR SHOWERS AND THUNDERSTORMS.
THERE IS UNCERTAINTY ON TIMING...COVERAGE AND INTENSITY THIS FAR
OUT AND THEN WITH OVERALL PATTERN EVOLUTION BEYOND SATURDAY
EVENING FRONT. STILL APPEARS IT WILL GENERALLY BE LESS ACTIVE THAN
WHAT WE HAVE SEEN MUCH OF THIS SUMMER AND SEASONABLY WARM.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* WESTERLY WINDS SHIFTING NORTHWEST NOW THEN NORTH NORTHEAST OVER
10 KT LATE TONIGHT THROUGH DAYBREAK.
MDB
//DISCUSSION...UPDATED 03Z...
COOL FRONT IS PASSING THROUGH THE AREA NOW. NOT EXPECTING ANY
SHOWERS AS THEY HAVE FADED OUT.
FROM 00Z...
THE MAIN SHOWER/THUNDER ACTIVITY REMAINS SOUTH OF THE TERMINALS
THIS EVENING AS AN UPPER TROUGH MOVES EAST ACROSS THE AREA. A COOL
FRONT IS APPROACHING FROM THE NORTHWEST AND HAS BEEN GENERATING
SOME SCATTERED SHRA/TSRA ACROSS SOUTHERN WI BUT THIS ACTIVITY IS
STARTING TO FADE AS IT REACHES LESS FAVORABLE AIR AND DAYTIME
HEATING DECREASES. RFD WILL HAVE THE BEST CHANCE FOR A BRIEF SHRA
OR EVEN A RUMBLE OF TS SO WILL MAINTAIN A TEMPO GROUP THERE. WILL
GO AHEAD AND REMOVE TEMPO SHOWERS FROM THE ORD/MDW/DPA/GYY TAFS AS
COVERAGE LOOKS TO BE QUITE SPOTTY BY THE TIME ANY ACTIVITY WOULD
ARRIVE SO THE POTENTIAL OF OCCURRENCE IS PRETTY LOW. WILL
CONTINUE WITH VCSH MENTION HOWEVER AND ADJUST THE TIMING. WINDS
HAVE TEMPORARILY TURNED WEST OR EVEN WEST-SOUTHWEST BUT WILL
SHIFT TO THE NORTHWEST WITH THE FRONTAL PASSAGE THIS EVENING THEN
MORE TO THE NORTH INTO THE OVERNIGHT. A SHIFT TO NORTH-NORTHEAST
IS EXPECTED TOWARD DAYBREAK. SPEEDS WILL LIKELY INCREASE A BIT
OVERNIGHT AS WELL.
DRY CONDITIONS ARE EXPECTED TUESDAY AS HIGH PRESSURE APPROACHES
FROM THE WEST. WINDS AT ORD MAY TURN NNW MID/LATE MORNING WITH THE
PRESSURE GRADIENT. MDW MAY SEE THE SAME THING OCCUR AS WELL. A LAKE
BREEZE WILL LIKELY DEVELOP AND MOVE INLAND AND MAY REACH ORD/MDW
BUT WINDS JUST ABOVE THE SURFACE MAY BE STRONG ENOUGH TO KEEP
INLAND PROGRESS SLOW SO IT IS NOT CLEAR IF IT WILL REACH ORD/MDW
OR NOT. WILL NEED TO KEEP AN EYE ON THIS. GYY WILL LIKELY SEE A
NORTH WIND WITH A SHIFT TO NNE TOWARD MIDDAY WHILE INLAND AREAS
SEE A STEADIER NORTHWEST WIND BY AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH CONFIDENCE IN WIND TRENDS THROUGH TUESDAY MORNING WITH
MEDIUM CONFIDENCE INTO TUESDAY AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. LIGHT WEST WINDS TURNING EAST WITH LAKE BREEZE IN
THE AFTERNOON.
THURSDAY...VFR. LIGHT SOUTH WINDS TURNING EAST-SOUTHEAST WITH LAKE
INFLUENCE IN THE AFTERNOON.
FRIDAY...VFR SOUTH WINDS.
SATURDAY...VFR. CHANCE TSRA. SOUTHWEST WINDS.
SUNDAY...VFR. WESTERLY WINDS.
MDB
&&
.MARINE...
230 PM CDT
A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE LAKE THIS EVENING
TURNING WINDS NORTH AND EVEN BRIEFLY NORTH-NORTHEAST. THERE IS
LIKELY TO BE SCATTERED SHOWERS AND A FEW STORMS AHEAD OF THE FRONT
ACROSS THE SOUTHERN HALF OF THE LAKE THROUGH MID-EVENING. THE
NORTHERLY WINDS BEHIND THE FRONT ARE EXPECTED TO REACH 15 TO 20 KT
FOR A 3-4 HOUR OR SO PERIOD LATE TONIGHT INTO EARLY TUESDAY
MORNING WITH POSSIBLY A FEW HIGHER GUSTS. BECAUSE OF THE SHORT
DURATION OF THE HIGHER SPEEDS...THIS IS EXPECTED TO ONLY BUILD
WAVES TO 2 TO 4 FEET ACROSS THE ILLINOIS AND INDIANA NEARSHORES ON
TUESDAY MORNING. HIGH PRESSURE IS THEN EXPECTED TO MOVE OVER THE
LAKE FOR A QUIET MIDWEEK PERIOD.
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:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
653 PM CDT MON JUL 20 2015
.SHORT TERM...
230 PM CDT
THROUGH TONIGHT...
A SHORT WAVE TROUGH AXIS ORIENTED FROM SOUTHWEST WISCONSIN THROUGH
FAR WESTERN ILLINOIS AS OF 230 PM WILL MOVE OVER THE FORECAST
AREA LATE THIS AFTERNOON. A PATCH OF CLEARING HAS ALLOWED
TEMPERATURES TO REACH MID 80S WITH A FEW UPPER 80S ATTAINED IN
EASTERN AREAS. THESE ARE AT CONVECTIVE VALUES GIVEN THE DEW POINTS
AND ACCORDINGLY SOME CUMULUS...A FEW TOWERING...HAVE DEVELOPED IN
THE AREA. LAPSE RATES ABOVE THE LFC REMAIN NON-IMPRESSIVE PER
AMDAR AND RAP ANALYSIS SO WHILE SOME SHOWERS MAY DEVELOP/INCREASE
IN COVERAGE WITH THIS IMPULSE AS IT MOVES EAST...THUNDER MAY STILL
BE HARD TO COME BY.
A SURFACE COLD FRONT EXTENDING FROM A LOW AT THE SOUTHERN TIP OF
JAMES BAY IN CANADA WILL MOVE SOUTHEAST THROUGH THE AREA THIS
EVENING...BASICALLY RIGHT IN THE WAKE OF THE AFOREMENTIONED SHORT
WAVE TROUGH. THE AIR MASS AHEAD OF THE FRONT IN WISCONSIN TO
EASTERN IOWA HAS STRUGGLED TO DESTABILIZE GIVEN CLOUD COVER...BUT
A FEW STORMS ARE STARTING TO POP AS THAT MOVES EAST. SCATTERED
SHOWERS AND A FEW STORMS SHOULD DEVELOP IMMEDIATELY UPSTREAM AND
SOME ARE ANTICIPATED TO PROGRESS INTO THE CWA BETWEEN 6 AND 9 PM.
COVERAGE SHOULD REMAIN SCATTERED. AS NOTED EARLIER...THE SOMEWHAT
LIMITED INSTABILITY SHOULD KEEP COVERAGE 30-50 PERCENT ALONG THE
BOUNDARY. WHILE SOME 35 MPH PLUS GUSTS MAY ACCOMPANY A FEW STORMS
GIVEN MARGINAL EFFECTIVE DEEP LAYER SHEAR AND 700-1000 J/KG OF
DCAPE...THE ATMOSPHERE REMAINS NON-CONDUCIVE FOR SEVERE STORMS.
THE FOCUS FOR SHOWERS SHOULD CLEAR THE CWA BY MIDNIGHT WITH
CLOUDS QUICKLY CLEARING AS WELL. A SECONDARY MOMENTUM PUSH OF THE
DRIER AIR MASS SHOULD ARRIVE LATE ON NORTHERLY WINDS...WITH LOW
TEMPERATURES BY DAYBREAK NEAR NORMAL.
MTF
&&
.LONG TERM...
328 PM CDT
TUESDAY THROUGH MONDAY...
NO SIGNIFICANT WEATHER CONCERNS FOR ONE OF THE FEW TIMES THIS
METEOROLOGICAL SUMMER. SURFACE HIGH PRESSURE REMAINING NEARLY
STATIONARY OVER THE REGION SHOULD KEEP THINGS DRY THROUGH
FRIDAY. EXPECTING DAILY LAKE BREEZE FORMATION THROUGH AT LEAST
THURSDAY. 12Z NAM DID HAVE A FEW PERIODS WITH CONVECTION FORECAST
TO POP ON LAKE BREEZE...WEDNESDAY EVENING AND THURSDAY
AFTERNOON...THOUGH DEWPOINTS SEEM TO BE HIGH BIASED EVEN WITH VERY
WET SUMMER SO FAR. THUS THINKING IS INSTABILITY WILL REMAIN
MINIMAL EVEN WITH A FEW UPPER DISTURBANCES MOVING OVER THE AREA
LATE WEDNESDAY AND AGAIN ON THURSDAY...COUPLING WITH DRY COLUMN TO
ENABLE DRY CONDITIONS TO PREVAIL. CANNOT COMPLETELY RULE OUT A
FEW ISOLATED SHOWERS BEING SQUEEZED OUT ON THURSDAY GIVEN STRONGER
VORT MAX.
TEMPERATURES ON TUESDAY SHOULD REACH AROUND 80 INLAND
BASED ON 925 MB TEMPS IN THE UPPER TEENS CELSIUS AND FAIRLY DEEP
MIXING. THEN EXPECT GRADUAL WARMING THE REST OF THE WEEK INTO THE
WEEKEND DUE TO RISING HEIGHTS FROM SOUTHERN CONUS MID/UPPER RIDGE.
GUIDANCE HAS OFTEN VERIFIED TOO HIGH THIS SUMMER WITH TEMPS...BUT
WONDER IF PROGGED THERMAL PROFILES MAY BE SUPPORTIVE OF A BIT
WARMER THAN FORECAST LOWER 80S ON WEDNESDAY AND THURSDAY AND LOWER
TO MID 80S ON FRIDAY SINCE THERE WILL LIKELY NOT BE CONVECTIVE
DEBRIS CLOUD COVER TO CONTEND WITH. DOES APPEAR A BIT BETTER
CHANCE FOR MID AND HIGH CLOUDS ON THURSDAY THOUGH AFTER A FEW TO
SCT CU ON WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE NORTHWEST
ON FRIDAY NIGHT AND THEN MOVE ACROSS THE AREA ON
SATURDAY...BRINGING A THREAT FOR SHOWERS AND THUNDERSTORMS.
THERE IS UNCERTAINTY ON TIMING...COVERAGE AND INTENSITY THIS FAR
OUT AND THEN WITH OVERALL PATTERN EVOLUTION BEYOND SATURDAY
EVENING FRONT. STILL APPEARS IT WILL GENERALLY BE LESS ACTIVE THAN
WHAT WE HAVE SEEN MUCH OF THIS SUMMER AND SEASONABLY WARM.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* LOW CHANCE FOR A SHOWER TOWARD 03Z.
* WESTERLY WINDS SHIFT NORTHWEST MID/LATE EVENING THEN NORTH-
NORTHEAST OVER 10 KT LATE TONIGHT THROUGH DAYBREAK.
MDB
//DISCUSSION...UPDATED 00Z...
THE MAIN SHOWER/THUNDER ACTIVITY REMAINS SOUTH OF THE TERMINALS
THIS EVENING AS AN UPPER TROUGH MOVES EAST ACROSS THE AREA. A COOL
FRONT IS APPROACHING FROM THE NORTHWEST AND HAS BEEN GENERATING
SOME SCATTERED SHRA/TSRA ACROSS SOUTHERN WI BUT THIS ACTIVITY IS
STARTING TO FADE AS IT REACHES LESS FAVORABLE AIR AND DAYTIME
HEATING DECREASES. RFD WILL HAVE THE BEST CHANCE FOR A BRIEF SHRA
OR EVEN A RUMBLE OF TS SO WILL MAINTAIN A TEMPO GROUP THERE. WILL
GO AHEAD AND REMOVE TEMPO SHOWERS FROM THE ORD/MDW/DPA/GYY TAFS AS
COVERAGE LOOKS TO BE QUITE SPOTTY BY THE TIME ANY ACTIVITY WOULD
ARRIVE SO THE POTENTIAL OF OCCURRENCE IS PRETTY LOW. WILL
CONTINUE WITH VCSH MENTION HOWEVER AND ADJUST THE TIMING. WINDS
HAVE TEMPORARILY TURNED WEST OR EVEN WEST-SOUTHWEST BUT WILL
SHIFT TO THE NORTHWEST WITH THE FRONTAL PASSAGE THIS EVENING THEN
MORE TO THE NORTH INTO THE OVERNIGHT. A SHIFT TO NORTH-NORTHEAST
IS EXPECTED TOWARD DAYBREAK. SPEEDS WILL LIKELY INCREASE A BIT
OVERNIGHT AS WELL.
DRY CONDITIONS ARE EXPECTED TUESDAY AS HIGH PRESSURE APPROACHES
FROM THE WEST. WINDS AT ORD MAY TURN NNW MID/LATE MORNING WITH THE
PRESSURE GRADIENT. MDW MAY SEE THE SAME THING OCCUR AS WELL. A LAKE
BREEZE WILL LIKELY DEVELOP AND MOVE INLAND AND MAY REACH ORD/MDW
BUT WINDS JUST ABOVE THE SURFACE MAY BE STRONG ENOUGH TO KEEP
INLAND PROGRESS SLOW SO IT IS NOT CLEAR IF IT WILL REACH ORD/MDW
OR NOT. WILL NEED TO KEEP AN EYE ON THIS. GYY WILL LIKELY SEE A
NORTH WIND WITH A SHIFT TO NNE TOWARD MIDDAY WHILE INLAND AREAS
SEE A STEADIER NORTHWEST WIND BY AFTERNOON.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE THAT CHANCE FOR SHRA OCCURRENCE AT THE TERMINALS
IS LOW.
* HIGH CONFIDENCE IN WIND TRENDS THROUGH TUESDAY MORNING WITH
MEDIUM CONFIDENCE INTO TUESDAY AFTERNOON.
MDB
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. LIGHT WEST WINDS TURNING EAST WITH LAKE BREEZE IN
THE AFTERNOON.
THURSDAY...VFR. LIGHT SOUTH WINDS TURNING EAST-SOUTHEAST WITH LAKE
INFLUENCE IN THE AFTERNOON.
FRIDAY...VFR SOUTH WINDS.
SATURDAY...VFR. CHANCE TSRA. SOUTHWEST WINDS.
SUNDAY...VFR. WESTERLY WINDS.
MDB
&&
.MARINE...
230 PM CDT
A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE LAKE THIS EVENING
TURNING WINDS NORTH AND EVEN BRIEFLY NORTH-NORTHEAST. THERE IS
LIKELY TO BE SCATTERED SHOWERS AND A FEW STORMS AHEAD OF THE FRONT
ACROSS THE SOUTHERN HALF OF THE LAKE THROUGH MID-EVENING. THE
NORTHERLY WINDS BEHIND THE FRONT ARE EXPECTED TO REACH 15 TO 20 KT
FOR A 3-4 HOUR OR SO PERIOD LATE TONIGHT INTO EARLY TUESDAY
MORNING WITH POSSIBLY A FEW HIGHER GUSTS. BECAUSE OF THE SHORT
DURATION OF THE HIGHER SPEEDS...THIS IS EXPECTED TO ONLY BUILD
WAVES TO 2 TO 4 FEET ACROSS THE ILLINOIS AND INDIANA NEARSHORES ON
TUESDAY MORNING. HIGH PRESSURE IS THEN EXPECTED TO MOVE OVER THE
LAKE FOR A QUIET MIDWEEK PERIOD.
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:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
125 AM CDT SUN JUL 19 2015
.SHORT TERM...
227 PM CDT
A FLASH FLOOD WATCH WAS ISSUED FOR THE ENTIRE WARNING AREA DUE TO
CONCERNS ABOUT TORRENTIAL RAINFALL RATES.
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.LONG TERM...
227 PM CDT
TOMORROW THROUGH TUESDAY...
A COLD FRONT WILL SHIFT ACROSS THE REGION ON SUNDAY. HOWEVER...IT
NOW APPEARS THAT THE BETTER THREAT FOR STRONG TO SEVERE STORMS ON
SUNDAY AFTERNOON MAY REMAIN SOUTH OF MY AREA ALL TOGETHER AS SHOWERS
AND THUNDERSTORMS TONIGHT INTO EARLY SUNDAY LOOK TO SHIFT THE MAIN
FOCUS FARTHER SOUTH THAN ORIGINALLY THOUGHT. WITH THIS IN MIND I
HAVE BACKED OFF ON POPS...ESPECIALLY SUNDAY AFTERNOON...WHEN I HAVE
FOCUSED THE HIGHEST POPS ACROSS MY EXTREME SOUTHERN COUNTIES IN
CENTRAL ILLINOIS.
ANOTHER CHANCE OF THUNDERSTORMS...WITH HEAVY RAINFALL AND POSSIBLY
STRONG WILL RETURN TO THE FORECAST ON MONDAY AS ANOTHER MID LEVEL
DISTURBANCE MOVES ACROSS THE AREA. GUIDANCE HAS NOT HAD THE BEST
HANDLE ON THIS DISTURBANCE THE PAST COUPLE OF RUNS...WITH IT
PREVIOUSLY APPEARING THAT THE MAIN THREAT OF STORMS COULD STAY SOUTH
OF THE AREA. HOWEVER...WITH THE POTENTIAL OF A FARTHER NORTH FOCUS
OF STORMS...I HAVE INCLUDED A CHANCE OF STORMS ON MONDAY...WITH
SLIGHTLY HIGHER POPS ACROSS THE SOUTHERN HALF OF THE AREA.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD OVER THE AREA ON
TUESDAY...SO IT APPEARS THAT TUESDAY COULD BE A DRY AND COOLER DAY
ACROSS THE AREA.
KJB
TUESDAY NIGHT THROUGH FRIDAY...
NORTHWEST FLOW ALOFT CONTINUES TUESDAY NIGHT THROUGH MID WEEK WITH A
FEW UPPER LEVEL WAVES MOVING THROUGH OVER THE END OF THE WEEK. AT
THE SURFACE HIGH PRESSURE SPREADS EAST OVER THE REGION TUESDAY NIGHT
AND THEN SHIFTS EAST OVER THE APPALACHIANS THURSDAY.
LOOKING AT A SHORT PERIOD OF DRY CONDITIONS THROUGH AT LEAST
WEDNESDAY NIGHT...POSSIBLY THROUGH THE END OF THE WEEK IF THE ECMWF
IS RIGHT. THE GFS FEATURES PRECIP ON THE BACKSIDE OF THE HIGH
THURSDAY NIGHT INTO FRIDAY. CONFIDENCE IS LOW SO KEPT THE CHANCE OF
PRECIP IN THE LOW END CHANCE OR LOWER RANGE.
FOR TEMPS...HAVE A SLOW WARMING TREND WITH TEMPS IN THE LOW TO MID
80S AND TEMPS COULD BE WARMER THAN FORECAST DEPENDING ON THE AMOUNT
OF PRECIP THAT OCCURS. THE GFS IS A BIT WARMER WITH 925MB TEMPS IN
THE MID TO UPPER 20S WHICH WOULD SUGGEST HIGH TEMPS IN THE 90S.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SLIGHT CHANCE OF SHRA TOWARD DAYBREAK.
* NORTH/NORTHWEST WINDS MID/LATE MORNING. CMS
//DISCUSSION...UPDATED 06Z...
A COLD FRONT WILL MOVE ACROSS THE AREA LATER THIS MORNING WITH
SOUTH/SOUTHWEST WINDS CURRENTLY...SHIFTING TO THE NORTH/NORTHWEST
AFTER SUNRISE. WINDS ARE EXPECTED TO TURN BACK A BIT MORE WEST/
NORTHWEST BY EARLY AFTERNOON AS THE LOW LEVELS MIX SOME. WIND
SPEEDS SHOULD INCREASE INTO THE 10KT RANGE BUT ITS POSSIBLE THAT
SPEEDS COULD BE A BIT HIGHER ALONG WITH SOME GUSTS INTO THE MID/
UPPER TEEN KT RANGE. A LAKE BREEZE WILL LIKELY FORM ALONG THE
NORTHWEST INDIANA SHORE AND PERHAPS ALONG THE ILLINOIS SHORE.
CONFIDENCE REGARDING HOW FAR INLAND THIS LAKE BREEZE MAY MOVE IS
FAIRLY LOW AND ALL GUIDANCE WOULD SUGGEST IT WOULD NOT MAKE IT AS
FAR WEST AS ORD/MDW. TRENDS WILL NEED TO BE MONITORED LATER THIS
AFTERNOON. WINDS WILL DIMINISH QUICKLY WITH SUNSET BECOMING LIGHT
SOUTHWESTERLY THIS EVENING.
AS THE COLD FRONT APPROACHES IN THE PREDAWN HOURS...ITS POSSIBLE
FOR A FEW SHOWERS TO DEVELOP. SHORT TERM/HI RES GUIDANCE HAS
SHOWN A DECREASE IN COVERAGE WITH THE MOST RECENT RUNS AND WITH
THE EXPECTED ISOLATED AND LIKELY SHORT DURATION IF ANYTHING DOES
DEVELOP...WILL CONTINUE WITH A DRY FORECAST. THE REST OF THE
PERIOD IS EXPECTED TO BE DRY WITH ANY PRECIP LIKELY SOUTH OF THE
TERMINALS. CMS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW FOR SHRA AROUND DAYBREAK.
* MEDIUM FOR WINDS THRU THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR. SLIGHT CHANCE OF TSRA.
TUESDAY...VFR. MOSTLY SUNNY.
WEDNESDAY...VFR. MOSTLY SUNNY.
THURSDAY...VFR. MOSTLY SUNNY.
FRIDAY...VFR. CHANCE OF TSRA.
ED F
&&
.MARINE...
125 AM...LOW PRESSURE OVER NORTHERN ONTARIO WILL MOVE TO NEAR
SOUTHERN HUDSON BAY TONIGHT AS A TRAILING COLD FRONT MOVES ACROSS
LAKE MICHIGAN THIS MORNING...SHIFTING WINDS WESTERLY. ANOTHER LOW
PRESSURE WILL DEVELOP OVER SOUTHERN MANITOBA THIS AFTERNOON AND
MOVE JUST SOUTH OF JAMES BAY MONDAY AFTERNOON AND THEN INTO
WESTERN QUEBEC MONDAY NIGHT. THE GRADIENT WILL BEGIN TO TIGHTEN
TONIGHT AHEAD OF THIS LOW...ESPECIALLY ACROSS NORTHERN LAKE
MICHIGAN. SPEEDS INTO THE 15-25KT LOOK REASONABLE WITH SOME HIGHER
GUSTS POSSIBLE. A STRONGER TRAILING COLD FRONT WILL MOVE SOUTH
ACROSS THE LAKE MONDAY NIGHT...LIKELY REACHING SOUTHERN LAKE
MICHIGAN BY TUESDAY MORNING. HIGH PRESSURE WILL BUILD ACROSS THE
PLAINS MONDAY NIGHT INTO TUESDAY SO THE GRADIENT BEHIND THIS FRONT
WILL TIGHTEN SOME. BUMPED NORTHERLY WIND UP A BIT...INTO THE 10-20
KT RANGE FOR MAINLY THE SOUTHERN HALF OF THE LAKE...BUT THIS TIME
PERIOD WILL NEED TO MONITORED FOR CHANGES. THE HIGH WILL MOVE
ACROSS THE LAKES REGION WEDNESDAY INTO THURSDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1223 AM CDT SUN JUL 19 2015
.SHORT TERM...
227 PM CDT
A FLASH FLOOD WATCH WAS ISSUED FOR THE ENTIRE WARNING AREA DUE TO
CONCERNS ABOUT TORRENTIAL RAINFALL RATES.
OUTFLOW BOUNDARY FROM EARLIER WISCONSIN MCS HAS SAGGED SOUTH INTO
NORTHERN CWA AND IS BEGINNING TO STALL OUT OVER NORTH CENTRAL
ILLINOIS. OVER NORTHEAST ILLINOIS THE LAKE HAS AUGMENTED THE
BOUNDARY AND PROVIDED SOME ADDITIONAL SOUTHWARD ACCELERATION
ADJACENT TO LAKE MICHIGAN. ANTICIPATE THE BOUNDARY WILL STALL OUT
EVEN OVER NORTHEAST ILLINOIS AND PROBABLY RETREAT NORTH DURING THE
DAY AS SUNSHINE ALLOWS FOR STRONG HEATING/MIXING AND A MODEST
SOUTHWEST WIND DEVELOPS. DESPITE THE INITIALLY COOLER AIR NEAR THE
LAKE...STILL FEEL THERE IS A REASONABLY GOOD CHANCE THAT THE
BOUNDARY WILL STALL/RETREAT ENOUGH TO PROVIDE FOR A HOT/HUMID
AFTERNOON WITH HEAT INDICES ABOVE 100 OVER EVEN NORTHEAST ILLINOIS
SO NOT PLANNING TO CHANGE HEAT ADVISORY ANY THIS MORNING. MAY
BROADEN THE RANGE OF HEAT INDICES TO 100 TO 110 AS CLOUDS FROM
IA/MO MCS MAY LIMIT THE HEAT SOME THIS AFTERNOON...MAINLY WESTERN
CWA.
AMPLE SUNSHINE IN ADVANCE OF ANY CLOUDINESS FROM MO/IA CONVECTION
WILL ALLOW FOR RAPID HEATING AND DESTABILIZATION ACROSS THE CWA
THROUGH EARLY AFTERNOON...BUT PARTICULARLY TO THE SOUTH OF THE WI
MCS REMNANT OUTFLOW BOUNDARY. DVN/ILX MORNING SOUNDINGS BOTH SHOW
MODERATELY STEEP LOW/MID LEVEL LAPSE RATES AND AS TEMPS/DEWPOINTS
RISE TOWARD PROJECTED HIGHS REGION SHOULD BE LEFT UNCAPPED BY
EARLY AFTERNOON...WITH MODIFIED ILX SOUNDING SUPPORTING SHOWING
MLCAPE VALUES NEARING 4000 J/KG BY EARLY THIS AFTERNOON WITH SFC
PARCEL OF 90/77...WHICH APPEARS EASILY ATTAINABLE IN THE WARM
SECTOR TODAY.
MORNING UPPER AIR ANALYSIS AND ACARS DATA SHOW 35-45KT FLOW
AROUND 6KM FROM IA INTO NORTHERN ILLINOIS WHICH WILL RESULT IN
0-6KM SHEAR VALUES OF AT LEAST AROUND 30KT...WHICH COMBINED WITH
SUCH STRONG INSTABILITY WOULD SUPPORT ORGANIZED CONVECTION AND
PERHAPS EVEN A SUPERCELL THREAT...ESPECIALLY IF ANY CELLS WERE TO
RIDE OUTFLOW BOUNDARY. PRIMARY SEVERE THREAT WOULD BE LARGE HAIL
AND DAMAGING WINDS...THOUGH CANNOT COMPLETELY RULE OUT A TORNADO
THREAT WITH ANY CELLS INTERACTING WITH BOUNDARIES GIVEN THE STRONG
LOW LEVEL CAPE AND LOW LCL HEIGHTS. OBVIOUSLY STILL SITTING IN A
VERY MOIST ENVIRONMENT SO HEAVY RAINFALL AND LOCALIZED FLASH
FLOODING IS ALSO A THREAT.
PLAN TO UPDATE GRIDS SHORTLY TO INTRODUCE POPS FOR THIS AFTERNOON
SPREADING THEM FROM WEST TO EAST. GENERALLY LIKE THE TRENDS IN THE
EXPERIMENTAL HRRR WHICH SHOWS STORMS DEVELOPING IN EAST AND
NORTHEAST OF THE IA/MO DECAYING MCS AND OUTFLOW BOUNDARY. WITH
MODEL GUIDANCE ALL OVER THE PLACE AND CAMS NOT HANDLING ONGOING
SITUATION WELL CONFIDENCE IS DIMINISHED...BUT CERTAINLY
OBSERVATIONAL TRENDS SUPPORT THE ABOVE FORECAST SCENARIO AND PLAN
TO INCREASE POPS INTO THE HIGH END CHANCE RANGE FOR NOW.
DESPITE THE HIGHER STORM CHANCES TODAY...PRIOR TO ANY STORMS HEAT
INDICES ARE LIKELY TO REACH 100 TO POTENTIALLY 110 DEGREES TODAY
SO LEAVING THE HEAT HEADLINES UNCHANGED.
GRIDS ARE GOING TO TAKE A LOT OF SURGERY TO REFLECT THE ABOVE
THINKING SINCE THERE IS NO REAL GUIDANCE REFLECTING CURRENT TRENDS
OR ABOVE THINKING...BUT FORECAST UPDATES ARE FORTHCOMING.
IZZI
&&
.LONG TERM...
227 PM CDT
TOMORROW THROUGH TUESDAY...
A COLD FRONT WILL SHIFT ACROSS THE REGION ON SUNDAY. HOWEVER...IT
NOW APPEARS THAT THE BETTER THREAT FOR STRONG TO SEVERE STORMS ON
SUNDAY AFTERNOON MAY REMAIN SOUTH OF MY AREA ALL TOGETHER AS SHOWERS
AND THUNDERSTORMS TONIGHT INTO EARLY SUNDAY LOOK TO SHIFT THE MAIN
FOCUS FARTHER SOUTH THAN ORIGINALLY THOUGHT. WITH THIS IN MIND I
HAVE BACKED OFF ON POPS...ESPECIALLY SUNDAY AFTERNOON...WHEN I HAVE
FOCUSED THE HIGHEST POPS ACROSS MY EXTREME SOUTHERN COUNTIES IN
CENTRAL ILLINOIS.
ANOTHER CHANCE OF THUNDERSTORMS...WITH HEAVY RAINFALL AND POSSIBLY
STRONG WILL RETURN TO THE FORECAST ON MONDAY AS ANOTHER MID LEVEL
DISTURBANCE MOVES ACROSS THE AREA. GUIDANCE HAS NOT HAD THE BEST
HANDLE ON THIS DISTURBANCE THE PAST COUPLE OF RUNS...WITH IT
PREVIOUSLY APPEARING THAT THE MAIN THREAT OF STORMS COULD STAY SOUTH
OF THE AREA. HOWEVER...WITH THE POTENTIAL OF A FARTHER NORTH FOCUS
OF STORMS...I HAVE INCLUDED A CHANCE OF STORMS ON MONDAY...WITH
SLIGHTLY HIGHER POPS ACROSS THE SOUTHERN HALF OF THE AREA.
SURFACE HIGH PRESSURE IS EXPECTED TO BUILD OVER THE AREA ON
TUESDAY...SO IT APPEARS THAT TUESDAY COULD BE A DRY AND COOLER DAY
ACROSS THE AREA.
KJB
TUESDAY NIGHT THROUGH FRIDAY...
NORTHWEST FLOW ALOFT CONTINUES TUESDAY NIGHT THROUGH MID WEEK WITH A
FEW UPPER LEVEL WAVES MOVING THROUGH OVER THE END OF THE WEEK. AT
THE SURFACE HIGH PRESSURE SPREADS EAST OVER THE REGION TUESDAY NIGHT
AND THEN SHIFTS EAST OVER THE APPALACHIANS THURSDAY.
LOOKING AT A SHORT PERIOD OF DRY CONDITIONS THROUGH AT LEAST
WEDNESDAY NIGHT...POSSIBLY THROUGH THE END OF THE WEEK IF THE ECMWF
IS RIGHT. THE GFS FEATURES PRECIP ON THE BACKSIDE OF THE HIGH
THURSDAY NIGHT INTO FRIDAY. CONFIDENCE IS LOW SO KEPT THE CHANCE OF
PRECIP IN THE LOW END CHANCE OR LOWER RANGE.
FOR TEMPS...HAVE A SLOW WARMING TREND WITH TEMPS IN THE LOW TO MID
80S AND TEMPS COULD BE WARMER THAN FORECAST DEPENDING ON THE AMOUNT
OF PRECIP THAT OCCURS. THE GFS IS A BIT WARMER WITH 925MB TEMPS IN
THE MID TO UPPER 20S WHICH WOULD SUGGEST HIGH TEMPS IN THE 90S.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SLIGHT CHANCE OF SHRA TOWARD DAYBREAK.
* NORTH/NORTHWEST WINDS MID/LATE MORNING. CMS
//DISCUSSION...UPDATED 06Z...
A COLD FRONT WILL MOVE ACROSS THE AREA LATER THIS MORNING WITH
SOUTH/SOUTHWEST WINDS CURRENTLY...SHIFTING TO THE NORTH/NORTHWEST
AFTER SUNRISE. WINDS ARE EXPECTED TO TURN BACK A BIT MORE WEST/
NORTHWEST BY EARLY AFTERNOON AS THE LOW LEVELS MIX SOME. WIND
SPEEDS SHOULD INCREASE INTO THE 10KT RANGE BUT ITS POSSIBLE THAT
SPEEDS COULD BE A BIT HIGHER ALONG WITH SOME GUSTS INTO THE MID/
UPPER TEEN KT RANGE. A LAKE BREEZE WILL LIKELY FORM ALONG THE
NORTHWEST INDIANA SHORE AND PERHAPS ALONG THE ILLINOIS SHORE.
CONFIDENCE REGARDING HOW FAR INLAND THIS LAKE BREEZE MAY MOVE IS
FAIRLY LOW AND ALL GUIDANCE WOULD SUGGEST IT WOULD NOT MAKE IT AS
FAR WEST AS ORD/MDW. TRENDS WILL NEED TO BE MONITORED LATER THIS
AFTERNOON. WINDS WILL DIMINISH QUICKLY WITH SUNSET BECOMING LIGHT
SOUTHWESTERLY THIS EVENING.
AS THE COLD FRONT APPROACHES IN THE PREDAWN HOURS...ITS POSSIBLE
FOR A FEW SHOWERS TO DEVELOP. SHORT TERM/HI RES GUIDANCE HAS
SHOWN A DECREASE IN COVERAGE WITH THE MOST RECENT RUNS AND WITH
THE EXPECTED ISOLATED AND LIKELY SHORT DURATION IF ANYTHING DOES
DEVELOP...WILL CONTINUE WITH A DRY FORECAST. THE REST OF THE
PERIOD IS EXPECTED TO BE DRY WITH ANY PRECIP LIKELY SOUTH OF THE
TERMINALS. CMS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW FOR SHRA AROUND DAYBREAK.
* MEDIUM FOR WINDS THRU THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...VFR. SLIGHT CHANCE OF TSRA.
TUESDAY...VFR. MOSTLY SUNNY.
WEDNESDAY...VFR. MOSTLY SUNNY.
THURSDAY...VFR. MOSTLY SUNNY.
FRIDAY...VFR. CHANCE OF TSRA.
ED F
&&
.MARINE...
233 PM CDT
THE MAIN CONCERNS OVER LAKE MICHGAN WILL BE THE THREAT OF SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING. CURRENTLY A LARGE AREA
OF THUNDERSTORMS DEVELOPING OVER SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS AND THIS ACTIVITY WILL MOVE OVER SOUTHERN LAKE MICHIGAN
THIS AFTERNOON INTO THE EVENING. EXPECT STRONG WINDS AND LOCALLY
HIGH WAVES IN AND AROUND THE STORMS.
OTHERWISE...THINGS SHOULD QUIET DOWN ON THE LAKE BY SUNDAY
FOLLOWING A COLD FRONTAL PASSAGE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
656 PM EDT SUN JUL 19 2015
.SYNOPSIS...
ISSUED AT 626 PM EDT SUN JUL 19 2015
A COLD FRONT WILL PUSH SOUTHWARD THROUGH THE REGION REACHING THE
OHIO RIVER VALLEY BY SUNRISE TOMORROW. A CHANCE FOR SHOWERS AND
THUNDERSTORMS WILL STAY ALONG AND AHEAD OF THE FRONT AS IT PUSHES
SOUTHWARD TONIGHT. BEHIND THE FRONT SKIES WILL BE CLEARING UP.
LOW TEMPERATURES TONIGHT WILL RANGE FROM THE LOWER 60S IN SOUTHERN
MICHIGAN TO THE LOWER 70S NEAR THE OHIO RIVER. HIGH PRESSURE WILL
BE OVER THE AREA MONDAY AS THE NEXT COLD FRONT APPROACHES FROM THE
NORTHWEST. HIGH TEMPERATURES ON MONDAY WILL RANGE FROM THE LOWER
80S IN SOUTHERN MICHIGAN TO THE MIDDLE 80S ALONG THE OHIO RIVER.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 343 PM EDT SUN JUL 19 2015
COLD FRONT IS CURRENTLY PUSHING SE THROUGH THE FORECAST AREA AS
OF 1930Z. SCATTERED CONVECTION HAS DEVELOPED AHEAD OF THE FRONT
FROM FORT WAYNE EASTWARD TO FINDLAY...WHERE SBCAPES HAVE REACHED
3000 TO 4000 J/KG. SHEAR IS WEAK WITH 500MB SPEED MAX WELL NORTH
OF THE AREA. FRONTAL FORCING IS WEAK AS WELL...WITH BETTER VEERING
WINDS AND LOWER TEMPS/DEWPOINTS WELL TO THE NORTHWEST. W/ MARGINAL
LAPSE RATES AND WEAK FORCING/SHEAR...EXPECT SEVERE THREAT TO BE
FAIRLY MINIMAL THROUGH THE REST OF THE AFTERNOON/EARLY EVENING.
ASIDE FROM A LOW DAMAGING WIND THREAT...HEAVY RAINFALL IS THE
PRIMARY THREAT GOING FORWARD...W/ PWATS MAXING OUT NEAR 2.00
INCHES SOUTH OF THE BOUNDARY.
AS FAR AS POPS GO...KEPT THEM IN THE CHANCE RANGE THROUGH 00Z...WITH
A GRADUAL DIMINISH FROM NORTH TO SOUTH AND THE FRONT CONTINUES TO
PUSH THROUGH THE AREA. THERE MAY BE AN UPTICK IN COVERAGE BETWEEN
21Z AND 00Z AS FRONTAL FORCING BECOMES A BIT STRONGER...HOWEVER HI
RES GUIDANCE...PARTICULARLY RECENT HRRR RUNS...HAVE SUGGESTED
MINIMAL ADDITIONAL COVERAGE THROUGH THIS TIME PERIOD. TAPERED OFF TO
DRY CONDITIONS AFTER 06Z...WITH CLEARING SKIES WORKING SOUTH THROUGH
THE FORECAST AREA AS WELL. LOWS SHOULD RANGE FROM THE LOW TO MID 60S
ACROSS THE AREA.
HIGH PRESSURE WILL MOVE QUICKLY ACROSS THE GREAT LAKES REGION LATE
OVERNIGHT THROUGH THE DAY MONDAY...AS THE FRONTAL BOUNDARY LINGERS
JUST SOUTH OF THE AREA. CLOUD COVER WILL INCREASE FROM THE WEST
THROUGH THE DAY AS A SHORTWAVE TRACKS EAST FROM KANSAS TOWARDS THE
OHIO VALLEY...AND ANOTHER COLD FRONT DROPS TOWARD THE AREA FROM THE
NORTHWEST. THIS MAY SPARK AN AFTERNOON THUNDERSTORM...MAINLY ACROSS
THE WEST/SOUTHWEST PART OF THE FORECAST AREA...AS VERY WEAK
DESTABILIZATION OCCURS...MAINLY SOUTHWEST OF THE FORECAST AREA.
CONFIDENCE IS LOW AT ANY PRECIP COVERAGE BEFORE 00Z...HOWEVER FOR
COLLABORATION SAKE...ADDED SLIGHT CHANCE POPS WEST/SOUTHWEST AFTER
21Z. HIGH TEMPS SHOULD REMAIN IN THE LOW TO MID 80S. WENT SLIGHTLY
COOLER THAN PREVIOUS FCST GIVEN EXPECTED CLOUD COVER AHEAD OF
UPSTREAM SYSTEMS.
&&
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 343 PM EDT SUN JUL 19 2015
DIFFUSE CDFNT MOVG THROUGH OUR AREA TODAY WILL STALL OUT OVER THE
OH VALLEY/MID MS VALLEY TONIGHT WITH REMNANT BOUNDARY AND
ASSOCIATED MOISTURE POOL LIFTING BACK N-NE MONDAY AS SHRTWV AND
ASSOCIATED CDFNT OVER SASK MOVES SE INTO THE UPR GRTLKS AND SECOND
VORT MAX OVER WY GETS INGESTED INTO THE WLYS AND MOVES TO THE MID
MS VALLEY. COMBINATION OF THESE TWO FORCING MECHANISMS AND RETURN
MOISTURE/DESTABILIZATION MAY BE SUFFICIENT TO CAUSE SCT TSTMS IN
OUR AREA MONDAY NIGHT... CONTINUED WITH HIGHEST POPS ACROSS
SOUTHERN PORTION OF THE CWA CLOSER TO THE TRACK OF THE SRN STREAM
VORT MAX. THE NRN STREAM SHRTWV MOVG THROUGH THE UPR GRTLKS WILL
RESULT IN STRENGTHENING OF THE ONTARIO UPR LOW AND AMPLIFICATION
OF THE FLOW ALOFT ACROSS THE CENTRAL CONUS/CANADA. THIS WILL ALLOW
A RATHER STRONG SFC HIGH TO DRIFT SLOWLY SE-E FROM THE NRN PLAINS
ACROSS THE GRTLKS PROVIDING FAIR WX ACROSS OUR AREA FOR THE
REMAINDER OF THE WORK-WEEK. BY THE WEEKEND... SFC HIGH SHOULD MOVE
TO THE ERN CONUS WITH MOISTURE/INSTABILITY/WAA RETURNING TO OUR
AREA AND COMBINING WITH WK SHRTWV`S MOVG OVER THE TOP OF THE SRN
PLAINS/ROCKIES UPR HIGH BRINGING A CHC OF TSTMS BACK TO OUR AREA.
THE NW FLOW ALOFT SHOULD KEEP TEMPS BLO NORMAL THROUGH THE
WORKWEEK...PSBLY RISING BACK ABOVE NORMAL NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 143 PM EDT SUN JUL 19 2015
COLD FRONT HAS PUSHED SOUTH THROUGH KSBN EARLY THIS
AFTERNOON...WITH VFR CONDITIONS EXPECTED THROUGH THE PERIOD.
SHOWERS AND THUNDERSTORMS HAVE DEVELOPED AHEAD OF THIS FRONT INVOF
KFWA...AND BASED ON RADAR COVERAGE...DECIDED TO TEMPO TSRA AT KFWA
THROUGH 23Z. FRONT WILL SLIDE SOUTH OF KFWA AROUND 00Z...ENDING
THE THUNDERSTORM THREAT WITH VFR CONDITIONS EXPECTED THROUGH THE
REST OF THE PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...NG
LONG TERM...JT
AVIATION...NG
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
350 PM EDT SUN JUL 19 2015
.SYNOPSIS...
ISSUED AT 343 PM EDT SUN JUL 19 2015
A COLD FRONT WILL CONTINUE TO PUSH SOUTH THROUGH THE AREA LATE THIS
AFTERNOON AND THIS EVENING. SCATTERED SHOWERS AND THUNDERSTORMS
ARE POSSIBLE ALONG AND AHEAD OF THE FRONT. DRY CONDITIONS AND
CLEARING SKIES WILL WORK SOUTH THROUGH THE AREA LATE TONIGHT. LOWS
OVERNIGHT WILL BE MUCH COOLER...WITH LOW TO MID 60S EXPECTED.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 343 PM EDT SUN JUL 19 2015
COLD FRONT IS CURRENTLY PUSHING SE THROUGH THE FORECAST AREA AS
OF 1930Z. SCATTERED CONVECTION HAS DEVELOPED AHEAD OF THE FRONT
FROM FORT WAYNE EASTWARD TO FINDLAY...WHERE SBCAPES HAVE REACHED
3000 TO 4000 J/KG. SHEAR IS WEAK WITH 500MB SPEED MAX WELL NORTH
OF THE AREA. FRONTAL FORCING IS WEAK AS WELL...WITH BETTER VEERING
WINDS AND LOWER TEMPS/DEWPOINTS WELL TO THE NORTHWEST. W/ MARGINAL
LAPSE RATES AND WEAK FORCING/SHEAR...EXPECT SEVERE THREAT TO BE
FAIRLY MINIMAL THROUGH THE REST OF THE AFTERNOON/EARLY EVENING.
ASIDE FROM A LOW DAMAGING WIND THREAT...HEAVY RAINFALL IS THE
PRIMARY THREAT GOING FORWARD...W/ PWATS MAXING OUT NEAR 2.00
INCHES SOUTH OF THE BOUNDARY.
AS FAR AS POPS GO...KEPT THEM IN THE CHANCE RANGE THROUGH 00Z...WITH
A GRADUAL DIMINISH FROM NORTH TO SOUTH AND THE FRONT CONTINUES TO
PUSH THROUGH THE AREA. THERE MAY BE AN UPTICK IN COVERAGE BETWEEN
21Z AND 00Z AS FRONTAL FORCING BECOMES A BIT STRONGER...HOWEVER HI
RES GUIDANCE...PARTICULARLY RECENT HRRR RUNS...HAVE SUGGESTED
MINIMAL ADDITIONAL COVERAGE THROUGH THIS TIME PERIOD. TAPERED OFF TO
DRY CONDITIONS AFTER 06Z...WITH CLEARING SKIES WORKING SOUTH THROUGH
THE FORECAST AREA AS WELL. LOWS SHOULD RANGE FROM THE LOW TO MID 60S
ACROSS THE AREA.
HIGH PRESSURE WILL MOVE QUICKLY ACROSS THE GREAT LAKES REGION LATE
OVERNIGHT THROUGH THE DAY MONDAY...AS THE FRONTAL BOUNDARY LINGERS
JUST SOUTH OF THE AREA. CLOUD COVER WILL INCREASE FROM THE WEST
THROUGH THE DAY AS A SHORTWAVE TRACKS EAST FROM KANSAS TOWARDS THE
OHIO VALLEY...AND ANOTHER COLD FRONT DROPS TOWARD THE AREA FROM THE
NORTHWEST. THIS MAY SPARK AN AFTERNOON THUNDERSTORM...MAINLY ACROSS
THE WEST/SOUTHWEST PART OF THE FORECAST AREA...AS VERY WEAK
DESTABILIZATION OCCURS...MAINLY SOUTHWEST OF THE FORECAST AREA.
CONFIDENCE IS LOW AT ANY PRECIP COVERAGE BEFORE 00Z...HOWEVER FOR
COLLABORATION SAKE...ADDED SLIGHT CHANCE POPS WEST/SOUTHWEST AFTER
21Z. HIGH TEMPS SHOULD REMAIN IN THE LOW TO MID 80S. WENT SLIGHTLY
COOLER THAN PREVIOUS FCST GIVEN EXPECTED CLOUD COVER AHEAD OF
UPSTREAM SYSTEMS.
&&
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 343 PM EDT SUN JUL 19 2015
DIFFUSE CDFNT MOVG THROUGH OUR AREA TODAY WILL STALL OUT OVER THE
OH VALLEY/MID MS VALLEY TONIGHT WITH REMNANT BOUNDARY AND
ASSOCIATED MOISTURE POOL LIFTING BACK N-NE MONDAY AS SHRTWV AND
ASSOCIATED CDFNT OVER SASK MOVES SE INTO THE UPR GRTLKS AND SECOND
VORT MAX OVER WY GETS INGESTED INTO THE WLYS AND MOVES TO THE MID
MS VALLEY. COMBINATION OF THESE TWO FORCING MECHANISMS AND RETURN
MOISTURE/DESTABILIZATION MAY BE SUFFICIENT TO CAUSE SCT TSTMS IN
OUR AREA MONDAY NIGHT... CONTINUED WITH HIGHEST POPS ACROSS
SOUTHERN PORTION OF THE CWA CLOSER TO THE TRACK OF THE SRN STREAM
VORT MAX. THE NRN STREAM SHRTWV MOVG THROUGH THE UPR GRTLKS WILL
RESULT IN STRENGTHENING OF THE ONTARIO UPR LOW AND AMPLIFICATION
OF THE FLOW ALOFT ACROSS THE CENTRAL CONUS/CANADA. THIS WILL ALLOW
A RATHER STRONG SFC HIGH TO DRIFT SLOWLY SE-E FROM THE NRN PLAINS
ACROSS THE GRTLKS PROVIDING FAIR WX ACROSS OUR AREA FOR THE
REMAINDER OF THE WORK-WEEK. BY THE WEEKEND... SFC HIGH SHOULD MOVE
TO THE ERN CONUS WITH MOISTURE/INSTABILITY/WAA RETURNING TO OUR
AREA AND COMBINING WITH WK SHRTWV`S MOVG OVER THE TOP OF THE SRN
PLAINS/ROCKIES UPR HIGH BRINGING A CHC OF TSTMS BACK TO OUR AREA.
THE NW FLOW ALOFT SHOULD KEEP TEMPS BLO NORMAL THROUGH THE
WORKWEEK...PSBLY RISING BACK ABOVE NORMAL NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 143 PM EDT SUN JUL 19 2015
COLD FRONT HAS PUSHED SOUTH THROUGH KSBN EARLY THIS
AFTERNOON...WITH VFR CONDITIONS EXPECTED THROUGH THE PERIOD.
SHOWERS AND THUNDERSTORMS HAVE DEVELOPED AHEAD OF THIS FRONT INVOF
KFWA...AND BASED ON RADAR COVERAGE...DECIDED TO TEMPO TSRA AT KFWA
THROUGH 23Z. FRONT WILL SLIDE SOUTH OF KFWA AROUND 00Z...ENDING
THE THUNDERSTORM THREAT WITH VFR CONDITIONS EXPECTED THROUGH THE
REST OF THE PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...NG
SHORT TERM...NG
LONG TERM...JT
AVIATION...NG
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
124 AM EDT SUN JUL 19 2015
.SYNOPSIS...
ISSUED AT 116 AM EDT SUN JUL 19 2015
A COLD FRONT WILL MOVE SOUTH THROUGH THE REGION TODAY. SCATTERED
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR THIS
FRONT...ESPECIALLY THIS AFTERNOON. HIGH TEMPERATURES WILL CLIMB TO
AROUND 90 AHEAD OF THE FRONT OVER NORTH CENTRAL INDIANA AND
NORTHWEST OHIO. IT WILL BE COOLER AND LESS HUMID BEHIND THE FRONT
WITH HIGHS IN THE MIDDLE 80S OVER FAR NORTHERN INDIANA AND
SOUTHWEST LOWER MICHIGAN.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 412 PM EDT SAT JUL 18 2015
MORNING/EARLY AFTERNOON MCS IS CURRENTLY PUSHING OUT OF LOCAL
FORECAST AREA TO THE EAST. THIS HAS PRODUCED A NOTICABLE OUTFLOW
BOUNDARY CURRENTLY EXTENDING FROM MICHIGAN CITY SE TO PORTLAND.
HAVE REMOVED MANY OF THE COUNTIES NORTH OF THIS OUTFLOW FROM THE
HEAT ADVISORY...ESPECIALLY EAST OF A WARSAW TO THREE RIVERS LINE.
WHILE TEMPERATURES MAY RECOVER INTO THE MID 80S...HEAT INDICES
SHOULD REMAIN BELOW CRITERIA. ELSEWHERE...TEMPERATURES WILL HOVER
AROUND 90 WITH HEAT INDICES AROUND 100...SO THE HEAT ADVISORY WILL
CONTINUE INTO THE EVENING.
CURRENTLY MONITORING UPSTREAM CONVECTIVE TRENDS ACROSS NRN IL. HI
RES GUIDANCE HAS BEEN LITTLE HELP TODAY REGARDING CONVECTIVE
TRENDS...HOWEVER LATEST RADAR DATA SHOWS ORGANIZATION ACROSS FAR NW
IL/SRN WI. HRRR SUGGEST CONTINUED WARM SECTOR STORM DEVELOPMENT
FURTHER SOUTH FROM EAST CENTRAL IL INTO WESTERN IN. THESE STORMS MAY
POSE AN ISOLATED SEVERE WEATHER THREAT...WITH DAMAGING WINDS AND
HEAVY RAINFALL THE MAIN THREAT. FURTHER INTEREST LIES WITH THE
ORGANIZATION ACROSS NRN IL. ANTICIPATE THAT THIS FEATURE MAY
PROPAGATE E/SE TOWARDS THE AREA BETWEEN 22Z AND 01Z...RIDING ALONG
THE APPRECIABLE INSTABILITY GRADIENT DEMARCATED BY THE
AFOREMENTIONED OUTFLOW BOUNDARY. SBCAPE VALUES BUILDING TO 4000
TO 6000 J/KG SOUTH OF THIS OUTFLOW W/ MID LVL LAPSE RATES NEAR 6.5
C/KM. EFFECTIVE SHEAR VALUES ARE MARGINAL...FROM 20-30 KTS ACROSS
THE AREA...HOWEVER IF THIS LINE CAN ORGANIZE...WHICH IT APPEARS TO
BE DOING AS I WRITE THIS...SHOULD BE SUFFICIENT TO MAINTAIN INTO
THE NORTHWEST PART OF THE AREA AROUND 00Z AS A SQUALL LINE/BOW
ECHO. THIS WOULD PRODUCE A BETTER THREAT FOR DAMAGING
WINDS...POTENTIALLY SIGNIFICANT...ROUGHLY ALONG THE OUTFLOW
BOUNDARY FROM MICHIGAN CITY TO JUST SOUTH OF FORT WAYNE. OF
COURSE...WITH THIS OUTFLOW BOUNDARY SITUATED ACROSS THE AREA...ANY
STORMS THAT PROPAGATE ALONG IT WILL MAINTAIN A HIGHER TORNADO RISK
W/ ENHANCED LOW LVL SHEAR. HAVE REFLECTED THIS IN THE GRIDS WITH A
DAMAGING WIND MENTION...FROM NW TO SE ACROSS THE FORECAST AREA
FROM 22Z TO 03Z. WILL BE MONITORING THIS CLOSELY OVER THE NEXT
SEVERAL HOURS.
FORECAST PICTURE BECOMES SOMEWHAT MUDDLED AFTER 06Z...AND WILL HINGE
ON CONVECTIVE EVOLUTION BETWEEN NOW AND THEN. LARGER SCALE FRONT
WILL PUSH SE INTO THE AREA BY TOMORROW MORNING. HAVE BACKED OFF POPS
A BIT...ESPECIALLY NW...LATE TONIGHT THROUGH SUNDAY. HIGHEST POPS
ARE CURRENTLY SUNDAY AFTN AS THE FRONT IS LAYED OUT FROM SW TO NE
ACROSS THE FCST AREA. HIGH TEMPS SUNDAY WERE CUT JUST A BIT AS
WELL...MAINLY ACROSS THE NW PORTION OF THE FORECAST AREA. THERE MAY
BE A FEW LOCATIONS THAT HAVE HEAT INDICES APPROACH 100
TOMORROW...MAINLY SOUTH AND EAST OF FORT WAYNE. HOWEVER...WITH
UNCERTAINTY IN THE PRECIP EVOLUTION AND TEMPS...WILL HOLD OFF ON ANY
HEAT HEADLINES RIGHT NOW FOR SUNDAY.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 412 PM EDT SAT JUL 18 2015
CDFNT EXPECTED TO BE MOVG THROUGH SERN PORTION OF CWA SUNDAY
EVE WITH TSTMS PSBL ALONG IT IN THE EVE. SFC HIGH SHOULD BUILD
INTO THE AREA MONDAY PROVIDING FAIR WX. MID LEVEL CUT-OFF LOW OVER
IDAHO THIS AFTN IS EXPECTED TO SHEAR EASTWARD ACROSS THE MID MS/OH
VALLEY MONDAY NIGHT/TUE BRINGING A CHC OF SHOWERS TO THE AREA.
RIDGING EXPECTED TO MOVE ACROSS THE AREA WED-FRI RESULTING IN FAIR
WX WITH A SLOW WARMING TREND. RETURN FLOW BEHIND THE SFC HIGH
COMBINING WITH A WK SHRTWV TOPPING UPR RIDGE MAY BRING TSTMS BACK
INTO THE AREA ON SATURDAY. OVERALL... TEMPS EXPECTED TO BE A BIT
BLO NORMAL DURING THE LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 116 AM EDT SUN JUL 19 2015
SKIES HAVE CLEARED BEHIND CONVECTION WITH VFR CONDITIONS. WINDS
WERE BECOMING LIGHT AND VARIABLE AND COUPLED WITH CLEAR SKIES AND
A MOIST GROUND COULD LEAD TO MVFR BR TOWARD DAYBREAK. HAVE
INCLUDED A TEMPO GROUP FOR THIS. A COLD FRONT WILL SAG SOUTHWARD
TODAY AND SHOULD CLEAR KSBN EARLY TO MID MORNING. JUST A SMALL
CHANCE FOR A SHRA OR TSRA THIS MORNING SO KEPT MENTION OUT OF TAF.
BETTER CHANCE AT KFWA BY EARLY AFTERNOON WITH BUILDING HEAT AND
INSTABILITY AHEAD OF FRONT. KEPT A VCTS FOR NOW. ANY TSRA THAT
DOES DEVELOP SHOULD MOVE SOUTH OF KFWA BY LATE AFTERNOON. VFR THEN
EXPECTED TO END THE PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...NG
LONG TERM...JT
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
500 PM MDT SUN JUL 19 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 157 PM MDT SUN JUL 19 2015
COMPLICATED SURFACE PATTERN IN PLACE. EITHER OR SOME COMBINATION
OF A LEFT OVER OUTFLOW BOUNDARY...SURFACE TROUGH RETREATING FRONT
IS NOW NEAR OR OVER THE SOUTHERN PORTION OF THE AREA. SHORTWAVE
TROUGH IS STARTING TO MOVE THROUGH FROM THE SOUTH AND WEST. A WEAK
RIGHT REAR QUADRANT IS MOVING THROUGH THE AREA DURING THE NIGHT.
THE RAP IS CATCHING THE SURFACE WIND FIELD THE BEST RIGHT NOW. IT
AND THE HRRR WHICH DID WELL FROM LAST NIGHT...IS CATCHING THE WIND
FIELD AND THE CURRENT AND EXPECTED THUNDERSTORM DEVELOPMENT VERY
WELL RIGHT NOW. STORMS WILL CONTINUE INCREASE IN COVERAGE AND
INTENSITY THROUGH TONIGHT AS STORMS MOVE ACROSS THE AREA THROUGH
THE OVERNIGHT HOURS.
VERY UNSTABLE AIR MASS AND EXPECT SOME OF THESE STORMS TO BECOME
SEVERE. HOWEVER THE BIGGEST THREAT WILL BE THE HEAVY RAINFALL AND
POSSIBLE FLASH FLOODING. AIR MASS REMAINS VERY MOIST THROUGH A
DEEP DEPTH. WHERE THE THREAT FOR HEAVY RAINFALL MATCHES UP WITH
WHERE HEAVY RAINFALL/SOME FLASH FLOODING OCCURRED LAST NIGHT/EARLY
THIS MORNING IS OVER THE SOUTHERN HALF OF THE AREA. THEREFORE A
FLASH FLOOD WATCH HAS BEEN ISSUED THROUGH TONIGHT.
VERY LIGHT LINGERING RAINFALL MAY BE AROUND THROUGH MID MORNING.
AFTER THAT IT SHOULD STAY QUIET UNTIL MID AFTERNOON. WEST TO
NORTHWEST FLOW ALOFT WITH ANOTHER SHORTWAVE TROUGH TO MOVE
THROUGH. AIR MASS DOES NOT APPEAR AS MOIST. ALSO SURFACE BOUNDARY
LOOKS TO BE SOUTH OF AREA. MODELS ARE NOT VERY EXCITED ABOUT THE
AFTERNOON RAINFALL CHANCES. HOWEVER CONSIDERING THE RESIDUAL
MOISTURE IN PLACE AND A SHORTWAVE TROUGH IN A WEST TO NORTHWEST
FLOW ALOFT...AM KEEPING SLIGHT TO CHANCE POPS FOR NOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 254 PM MDT SUN JUL 19 2015
FOR THE EXTENDED FORECAST PERIOD...NEEDED TO MAKE SOME CHANGES FOR
THIS RUN AS MODELS HAVE COME INTO BETTER AGREEMENT WITH RESPECT TO
TWO FEATURES. FIRST...GUIDANCE IS HONING IN ON A MORE SOUTHERN
SOLUTION WITH REGARDS TO PRECIPITATION CHANCES MONDAY NIGHT THROUGH
TUESDAY NIGHT. THIS IS LIKELY DUE TO A FURTHER SOUTH PUSH FROM THE
FRONT THAN ORIGINALLY ANTICIPATED. SECOND...GUIDANCE IS IN BETTER
AGREEMENT ON THE LOCATION AND STRENGTH OF THE 500 MB HIGH PRESSURE
RIDGE THAT DEVELOPS TOWARDS THE END OF THE WEEK.
BEGINNING WITH MONDAY NIGHT...ANTICIPATE RELATIVELY QUIET WEATHER
DUE TO THE FRONT AND THUS CONVECTIVE ACTIVITY REMAINING FURTHER
SOUTH. SOME MODELS CONTINUE INDICATING ISENTROPIC LIFT DEVELOPING AS
A LOW LEVEL JET STRENGTHENS OVER THE FRONT. A NARROW TONGUE OF
INSTABILITY RETURNS WITHIN THE SOUTHEASTER FLOW EARLY TUESDAY
MORNING SO SOME ELEVATED SHOWERS/STORMS MAY BE ABLE TO DEVELOP. ALL
PARAMETERS ARE DELAYED BY 6-12 HOURS FROM YESTERDAY SO ACTIVITY MAY
HOLD OFF UNTIL AFTER SUNRISE TUESDAY. THEREFORE...LOWERED POPS FOR
MONDAY NIGHT.
FOR TUESDAY THROUGH WEDNESDAY...ANOTHER WET PERIOD IS ANTICIPATED.
UNCERTAINTY REMAINS ON THE EXACT AXIS WHERE THE RAIN WILL OCCUR. IN
ADDITION...THERE MAY BE A TIGHT GRADIENT BETWEEN LITTLE TO NO
RAINFALL AND ANOTHER ROUND OF BENEFICIAL SOAKING RAINS. THE BEST
FORCING SHOULD ARRIVE DURING THE DAY TUESDAY...SLOWLY TRANSITIONING
INTO CENTRAL KANSAS BY WEDNEDAY MORNING. THEREFORE...THE BEST
CHANCES FOR WIDESPREAD PRECIPITATION SHOULD OCCUR TUESDAY NIGHT WITH
CHANCES DIMINISHING WEDNESDAY. PRECIPITABLE WATER VALUES INCREASE
TUESDAY AND TUESDAY NIGHT...REACHING A MAXIMUM NEAR 1.60 INCHES BY
WEDNESDAY MORNING. THEREFORE...RAIN COULD BE HEAVY AT TIMES WITH
SOME THUNDERSTORMS.
BY LATE WEDNESDAY INTO THURSDAY...THE RIDGE OF HIGH PRESSURE OVER
THE SOUTHERN UNITED STATES SLIDES WEST AND STRENGTHENS/BUILDS NORTH
OVER THE HIGH PLAINS. THIS SHOULD LEAD TO AN END IN PRECIPITATION
CHANCES FOR THE MOST PART AS WELL AS A RETURN TO HOT TEMPERATURES.
FOR THURSDAY THROUGH AT LEAST NEXT WEEKEND...SOME MEMBERS OF THE
FORECAST GUIDANCE DO INDICATE CHANCES FOR ISOLATED THUNDERSTORMS.
HOWEVER...THERE IS NOT A CONSISTENT SIGNAL AMONGST THE GUIDANCE AND
NO TIME PERIODS IN PARTICULAR TO HONE IN ON. IN FACT...THINK THAT
MOST LIKELY THE REGION REMAINS DRY DUE TO CLOSENESS/STRENGTH OF THE
HIGH PRESSURE RIDGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 456 PM MDT SUN JUL 19 2015
AFTER STORMS MOVE THROUGH KGLD AND KMCK THIS EVENING,VFR
CONDITIONS WILL RESUME AT BOTH SITES. SHORTWAVE ENERGY MOVING EAST
OF THE ROCKIES WILL SUPPORT CONTINUED THUNDERSTORM DEVELOPMENT
THIS EVENING. DO NOT SEE ANY STRATUS DEVELOPMENT BEHIND THE STORMS
MONDAY MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR KSZ013>016-027>029-
041-042.
CO...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR COZ091-092.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
254 PM MDT SUN JUL 19 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 157 PM MDT SUN JUL 19 2015
COMPLICATED SURFACE PATTERN IN PLACE. EITHER OR SOME COMBINATION
OF A LEFT OVER OUTFLOW BOUNDARY...SURFACE TROUGH RETREATING FRONT
IS NOW NEAR OR OVER THE SOUTHERN PORTION OF THE AREA. SHORTWAVE
TROUGH IS STARTING TO MOVE THROUGH FROM THE SOUTH AND WEST. A WEAK
RIGHT REAR QUADRANT IS MOVING THROUGH THE AREA DURING THE NIGHT.
THE RAP IS CATCHING THE SURFACE WIND FIELD THE BEST RIGHT NOW. IT
AND THE HRRR WHICH DID WELL FROM LAST NIGHT...IS CATCHING THE WIND
FIELD AND THE CURRENT AND EXPECTED THUNDERSTORM DEVELOPMENT VERY
WELL RIGHT NOW. STORMS WILL CONTINUE INCREASE IN COVERAGE AND
INTENSITY THROUGH TONIGHT AS STORMS MOVE ACROSS THE AREA THROUGH
THE OVERNIGHT HOURS.
VERY UNSTABLE AIR MASS AND EXPECT SOME OF THESE STORMS TO BECOME
SEVERE. HOWEVER THE BIGGEST THREAT WILL BE THE HEAVY RAINFALL AND
POSSIBLE FLASH FLOODING. AIR MASS REMAINS VERY MOIST THROUGH A
DEEP DEPTH. WHERE THE THREAT FOR HEAVY RAINFALL MATCHES UP WITH
WHERE HEAVY RAINFALL/SOME FLASH FLOODING OCCURRED LAST NIGHT/EARLY
THIS MORNING IS OVER THE SOUTHERN HALF OF THE AREA. THEREFORE A
FLASH FLOOD WATCH HAS BEEN ISSUED THROUGH TONIGHT.
VERY LIGHT LINGERING RAINFALL MAY BE AROUND THROUGH MID MORNING.
AFTER THAT IT SHOULD STAY QUIET UNTIL MID AFTERNOON. WEST TO
NORTHWEST FLOW ALOFT WITH ANOTHER SHORTWAVE TROUGH TO MOVE
THROUGH. AIR MASS DOES NOT APPEAR AS MOIST. ALSO SURFACE BOUNDARY
LOOKS TO BE SOUTH OF AREA. MODELS ARE NOT VERY EXCITED ABOUT THE
AFTERNOON RAINFALL CHANCES. HOWEVER CONSIDERING THE RESIDUAL
MOISTURE IN PLACE AND A SHORTWAVE TROUGH IN A WEST TO NORTHWEST
FLOW ALOFT...AM KEEPING SLIGHT TO CHANCE POPS FOR NOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 254 PM MDT SUN JUL 19 2015
FOR THE EXTENDED FORECAST PERIOD...NEEDED TO MAKE SOME CHANGES FOR
THIS RUN AS MODELS HAVE COME INTO BETTER AGREEMENT WITH RESPECT TO
TWO FEATURES. FIRST...GUIDANCE IS HONING IN ON A MORE SOUTHERN
SOLUTION WITH REGARDS TO PRECIPITATION CHANCES MONDAY NIGHT THROUGH
TUESDAY NIGHT. THIS IS LIKELY DUE TO A FURTHER SOUTH PUSH FROM THE
FRONT THAN ORIGINALLY ANTICIPATED. SECOND...GUIDANCE IS IN BETTER
AGREEMENT ON THE LOCATION AND STRENGTH OF THE 500 MB HIGH PRESSURE
RIDGE THAT DEVELOPS TOWARDS THE END OF THE WEEK.
BEGINNING WITH MONDAY NIGHT...ANTICIPATE RELATIVELY QUIET WEATHER
DUE TO THE FRONT AND THUS CONVECTIVE ACTIVITY REMAINING FURTHER
SOUTH. SOME MODELS CONTINUE INDICATING ISENTROPIC LIFT DEVELOPING AS
A LOW LEVEL JET STRENGTHENS OVER THE FRONT. A NARROW TONGUE OF
INSTABILITY RETURNS WITHIN THE SOUTHEASTER FLOW EARLY TUESDAY
MORNING SO SOME ELEVATED SHOWERS/STORMS MAY BE ABLE TO DEVELOP. ALL
PARAMETERS ARE DELAYED BY 6-12 HOURS FROM YESTERDAY SO ACTIVITY MAY
HOLD OFF UNTIL AFTER SUNRISE TUESDAY. THEREFORE...LOWERED POPS FOR
MONDAY NIGHT.
FOR TUESDAY THROUGH WEDNESDAY...ANOTHER WET PERIOD IS ANTICIPATED.
UNCERTAINTY REMAINS ON THE EXACT AXIS WHERE THE RAIN WILL OCCUR. IN
ADDITION...THERE MAY BE A TIGHT GRADIENT BETWEEN LITTLE TO NO
RAINFALL AND ANOTHER ROUND OF BENEFICIAL SOAKING RAINS. THE BEST
FORCING SHOULD ARRIVE DURING THE DAY TUESDAY...SLOWLY TRANSITIONING
INTO CENTRAL KANSAS BY WEDNEDAY MORNING. THEREFORE...THE BEST
CHANCES FOR WIDESPREAD PRECIPITATION SHOULD OCCUR TUESDAY NIGHT WITH
CHANCES DIMINISHING WEDNESDAY. PRECIPITABLE WATER VALUES INCREASE
TUESDAY AND TUESDAY NIGHT...REACHING A MAXIMUM NEAR 1.60 INCHES BY
WEDNESDAY MORNING. THEREFORE...RAIN COULD BE HEAVY AT TIMES WITH
SOME THUNDERSTORMS.
BY LATE WEDNESDAY INTO THURSDAY...THE RIDGE OF HIGH PRESSURE OVER
THE SOUTHERN UNITED STATES SLIDES WEST AND STRENGTHENS/BUILDS NORTH
OVER THE HIGH PLAINS. THIS SHOULD LEAD TO AN END IN PRECIPITATION
CHANCES FOR THE MOST PART AS WELL AS A RETURN TO HOT TEMPERATURES.
FOR THURSDAY THROUGH AT LEAST NEXT WEEKEND...SOME MEMBERS OF THE
FORECAST GUIDANCE DO INDICATE CHANCES FOR ISOLATED THUNDERSTORMS.
HOWEVER...THERE IS NOT A CONSISTENT SIGNAL AMONGST THE GUIDANCE AND
NO TIME PERIODS IN PARTICULAR TO HONE IN ON. IN FACT...THINK THAT
MOST LIKELY THE REGION REMAINS DRY DUE TO CLOSENESS/STRENGTH OF THE
HIGH PRESSURE RIDGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1143 AM MDT SUN JUL 19 2015
SIMILAR SETUP TO LAST NIGHTS ROUND OF THUNDERSTORMS. AT THIS TIME
IT LOOKS LIKE THUNDERSTORMS WILL START A LITTLE EARLIER. THE
STORMS LOOK A LITTLE FURTHER SOUTH THAN THEY DID LAST NIGHT. KGLD
STILL LOOKS LIKE THE BEST CHANCE TO BE AFFECTED BY THE
THUNDERSTORMS. SO CHOSE TO PUT VCTS AT KGLD AT 21Z WITH A
PREVAILING THUNDERSTORM FORECAST FROM 00Z TO 04Z. AT THIS TIME FOR
KGLD KEPT CONDITIONS AT VFR FOR THE ENTIRE TIME BUT IF A STRONG
STORM MOVES ACROSS THEN MVFR CONDITIONS WILL BE POSSIBLE.
ADDITIONAL THUNDERSTORMS ARE POSSIBLE TOMORROW AFTERNOON BUT CHOSE
TO KEEP ANY THUNDERSTORM MENTION OUT OF THE TAF.
DO NOT FEEL AS CONFIDENT ABOUT KMCK GETTING THUNDERSTORMS BUT IT
WILL BE CLOSE. CHOSE TO PUT IN VCTS THERE FROM 01Z TO 05Z. VFR
CONDITIONS ARE EXPECTED THROUGH THE ENTIRE TIME. ALSO KEPT ANY
MENTION THUNDERSTORMS OUT FOR MONDAY AFTERNOON AT THIS TIME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR KSZ013>016-027>029-
041-042.
CO...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR COZ091-092.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...RRH
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS TOPEKA KS
342 PM CDT SUN JUL 19 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 309 PM CDT SUN JUL 19 2015
THE UPPER LEVEL TROUGH AND MCV THAT HELPED PROVIDE ASCENT FOR THE
COMPLEX OF THUNDERSTORMS THAT MOVED ACROSS THE NORTHERN HALF OF THE
CWA THIS MORNING HAS NOW MOVED EAST ACROSS NORTHERN MO INTO IL. THE
NORTHERN COUNTIES OF THE CWA ALONG THE NE BORDER PICKED UP BETWEEN 2
TO 5 INCHES OF RAINFALL WHICH RESULTED IN SOME FLASH FLOODING
BETWEEN 6 AM-8AM. A SURFACE OUTFLOW BOUNDARY HAS MOVED SOUTH ACROSS
MUCH OF THE CWA...THOUGH THE SOUTHERN COUNTIES WERE BEGIN TO
RECOVER INTO THE LOWER 80S WITH MID 70 DEWPOINTS.
THE MESOSCALE MODELS DO NOT SHOW ANY THUNDERSTORMS DEVELOPING ALONG
THE OUTFLOW BOUNDARY ACROSS EAST CENTRAL KS. I`LL PROBABLY JUST GO
WITH 14 POPS FOR TONIGHT AND THROUGH MUCH OF THE EVENING HOURS.
EASTERLY UPSLOPE FLOW COMBINED WITH ASCENT FRONT ANOTHER WEAK UPPER
LEVEL TROUGH WILL CAUSE NUMEROUS SHOWERS AND THUNDERSTORMS TO
DEVELOP ACROSS THE HIGH PLAINS OF EASTERN CO AND WESTERN KS LATE
THIS AFTERNOON AND THROUGH THE EVENING HOURS. I EXPECT AN
MCS/COMPLEX OF THUNDERSTORMS TO DEVELOP ACROSS WESTERN KS DURING THE
MID EVENING HOURS AND TRACK EAST-NORTHEAST ACROSS EASTERN KS DURING
THE LATE EVENING AND MORNING HOURS OF MONDAY. THERE`S STILL SOME
UNCERTAINTY TO WHERE THE MCS WILL FORM AND TRACK. THE HRRR HAS BEEN
PERFORMING WELL BETWEEN 03Z-12Z THE PAST FEW DAYS AND SHOWS THE
COMPLEX OF STORMS DEVELOPING ACROSS WEST CENTRAL AND SOUTHWEST KS
AND MOVING NORTHEAST ACROSS THE NORTHERN COUNTIES OF THE CWA. THE
WRF SOLUTIONS ARE A BIT FARTHER SOUTH ALONG THE I-70 CORRIDOR. THE
12Z NAM SHOWS THE COMPLEX OF STORMS WEAKENING THROUGH THE EARLY
MORNING HOURS ONCE IT REACHES CENTRAL AND NORTH CENTRAL KS. DUE TO
THE HEAVY RAINFALL THIS MORNING ACROSS THE NORTHERN COUNTIES OF THE
CWA...AND THE CHANCE OF AN MCS OR COMPLEX OF STORMS MOVING ACROSS
THE SAME AREA DURING THE EARLY MORNING HOURS OF MONDAY...I HAVE
DECIDED TO ISSUE A FLASH FLOOD WATCH IN EFFECT FROM 9 PM THROUGH 11
AM MONDAY. THE FLASH FLOOD WATCH IS GENERALLY ALONG A MINEAPOLIS TO
MANHATTAN...TO HOYT...TO OKALOOSA LINE. COUNTIES FARTHER SOUTH MAY
HAVE TO BE ADDED ON THIS EVENING IF THE MCS DEVELOPS FARTHER SOUTH
AND MOVES ACROSS THE CENTRAL OR SOUTHERN COUNTIES OF THE CWA. THE
ENVIRONMENT LATE TONIGHT AND THROUGH THE MORNING HOURS ACROSS
NORTHEAST KS WILL CONSIST OF 2000-3000 MUCAPE ALONG WITH 0-6KM
EFFECTIVE SHEAR OF 25 TO 35 KTS. THEREFORE SOME OF THE STRONGER
UPDRAFTS IN A COMPLEX OF STORMS MAY BE SEVERE WITH THE PRIMARY
HAZARD BEING DAMAGING WIND GUSTS AND HAIL UP TO HALF DOLLAR SIZE. IF
A FORWARD PROPAGATING MCS DEVELOPS THEN THERE MAY BE MORE WIDESPREAD
DAMAGING WIND GUSTS. ANY MCS OR COMPLEX OF THUNDERSTORMS WILL
PRODUCE HEAVY RAINFALL WITH FORECAST PWATS IN THE 1.9-2.25 INCH
RANGE.
MONDAY...THE COMPLEX OF STORMS WILL BE ONGOING ACROSS PORTIONS OF
THE CWA DURING THE MORNING HOURS. THE UPPER LEVEL TROUGH WILL MOVE
EAST-SOUTHEAST ACROSS EASTERN NE AND EASTERN KS DURING THE AFTERNOON
HOUR. THERE COULD BE A BREAK IN THE THUNDERSTORM CHANCES DURING THE
EARLY AFTERNOON HOURS BUT THE EASTERN COUNTIES MAY SEE NEW STORMS
DEVELOP ON A STRONGER SURFACE FRONT THAT WILL PUSH SOUTHEAST ACROSS
THE CWA DURING THE AFTERNOON HOURS. HIGHS WILL REMAIN COOLER DUE TO
THE MORNING RAIN CHANCES AND CLOUD COVER INTO THE EARLY AFTERNOON
HOURS. HIGHS WILL RANGE FROM THE MID 80S ALONG THE NE BORDER TO
LOWER 80S ACROSS THE SOUTHWEST COUNTIES.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 309 PM CDT SUN JUL 19 2015
MONDAY NIGHT THROUGH WEDNESDAY...PREVIOUSLY MENTIONED FRONT
PUSHES DOWN TO NEAR KS/OK BORDER BY MIDNIGHT MONDAY NIGHT. COULD
BE A FEW LINGERING STORMS IN THE EAST CENTRAL MONDAY EVENING.
AFTER MIDNIGHT...A WEAK SYSTEM MOVING THROUGH THE NEAR ZONAL FLOW
COMBINES WITH ISENTROPIC UPLIFT OVER THE THERMAL BOUNDARY TO GIVE
ANOTHER CHANCE FOR SHOWERS AND STORMS IN EAST CENTRAL KS AND
AREAS SOUTH. ON TUESDAY...SUBSIDENCE BEHIND WEAK WAVE AND
INFLUENCE OF SURFACE HIGH PRESSURE RIDGE SHOULD KEEP AREA DRY WITH
LOWER DEWPOINTS AND COOLER TEMPERATURES IN THE 80S.
ANOTHER WEAK TROUGH IN THE ZONAL FLOW ALOFT AFFECTS THE AREA ON
TUESDAY NIGHT AND WEDNESDAY. WHILE SURFACE BOUNDARY IS FORECAST BY
THE MODELS TO EDGE NORTHWARD...BEST LIFT SHOULD BE ACROSS THE
SOUTHERN HALF OF KS AND HAVE CONFINED HIGHEST POPS AND LARGER QPF
TO OUR EAST CENTRAL KS COUNTIES TO THE SOUTH OF I70.
THURSDAY THROUGH SUNDAY...LATE WEEK LOOKS TO HAVE SEVERAL ON AND
OFF CHANCES OF PRECIP. THURSDAY WILL LIKELY BE THE WETTEST DAY
WITH PLENTY OF SUBTROPICAL MOISTURE EXTENDING UP INTO THE REGION
AS WELL A COUPLE MID LEVEL IMPULSES WORKING OUT OF THE CENTRAL
ROCKIES AND OVER NORTHEASTERN KS. GENERALLY HAVE POPS DECREASING
HEADING INTO THURSDAY AFTERNOON TAPERING OFF FAIRLY SHARPLY BY
EVENING WITH A HIGHLY AMPLIFIED BUT NARROW UPPER RIDGE BUILDING
INTO THE CENTRAL PLAINS EXTENDING INTO THE UPPER MISSISSIPPI
VALLEY FOR FRIDAY. BY SATURDAY MORNING A BROADER MID LEVEL RIDGE
SITUATES ITSELF OVER THE SOUTHERN AND CENTRAL ROCKIES WITH A
NORTHWEST FLOW REGIME IN PLACE OVER THE OUTLOOK AREA. THIS WILL
LIKELY PROVIDE SOME SMALL CHANCES FOR SCATTERED PRECIP ON SATURDAY
MORNING MAINLY OVER AREAS NEAR THE KS/NE BORDER. THE LONG TERM
MODELS DIFFER A BIT AT THIS POINT AS THE ECMWF SUGGESTS THAT AN
MCS WILL HAVE DEVELOPED OVERNIGHT FRIDAY AND MOVE INTO THE REGION
BY SATURDAY MORNING, WHILE THE GFS AND CANADIAN SUGGEST THAT A
WEAK BOUNDARY WILL BE FORCED INTO THE AREA ASSOCIATED WITH THE
BROADER TROUGH OF THE WESTERLIES MOVING INTO THE UPPER MISSISSIPPI
VALLEY. EITHER WAY, IT DOES APPEAR THERE WILL BE AT LEAST SOME
SUPPORT FOR SHOWERS AND MORNING THUNDERSTORMS SATURDAY. WITH A
SITUATION THAT LOOKS TO LEAVE SEVERAL POTENTIAL BOUNDARIES IN PLAY
OVER THE REGION, SUNDAY COULD SEE ANOTHER CHANCE FOR PRECIP AS A
WEAK WAVE TURNS THE RIDGE AND INSTABILITY SETS UP WITH DAYTIME
HEATING.
HIGHS DURING THE PERIOD WILL LIKELY BE INTO THE 90S FOR FRIDAY
THROUGH SUNDAY WITH WARMEST TESMPERATURES IN PARTS OF CENTRAL KS.
LOWS LIKELY REMAIN IN THE 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1231 PM CDT SUN JUL 19 2015
EXPECT BRIEF MVFR CEILINGS TO LIFT WITHIN THE HOUR AT TOP/MHK TO
VFR. THERE IS A SLIGHT CHANCE FOR A LATE AFTERNOON/EVENING VCTS FOR
SITES, BUT HIGH UNCERTAINTY OF DEVELOPMENT WILL KEEP THIS MENTION
OUT OF THE TAFS. STORMS WILL MOVE IN FROM THE WEST TONIGHT AND WILL
LIKELY EFFECT ALL TERMINALS. KEPT THE TIMING OF VCTS BETWEEN 05-06Z
UNTIL BETTER STORM EVOLUTION IS KNOWN.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR KSZ058-059.
&&
$$
SHORT TERM...GARGAN
LONG TERM...PHILLIPS/DRAKE
AVIATION...HELLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
215 PM MDT SUN JUL 19 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 157 PM MDT SUN JUL 19 2015
COMPLICATED SURFACE PATTERN IN PLACE. EITHER OR SOME COMBINATION
OF A LEFT OVER OUTFLOW BOUNDARY...SURFACE TROUGH RETREATING FRONT
IS NOW NEAR OR OVER THE SOUTHERN PORTION OF THE AREA. SHORTWAVE
TROUGH IS STARTING TO MOVE THROUGH FROM THE SOUTH AND WEST. A WEAK
RIGHT REAR QUADRANT IS MOVING THROUGH THE AREA DURING THE NIGHT.
THE RAP IS CATCHING THE SURFACE WIND FIELD THE BEST RIGHT NOW. IT
AND THE HRRR WHICH DID WELL FROM LAST NIGHT...IS CATCHING THE WIND
FIELD AND THE CURRENT AND EXPECTED THUNDERSTORM DEVELOPMENT VERY
WELL RIGHT NOW. STORMS WILL CONTINUE INCREASE IN COVERAGE AND
INTENSITY THROUGH TONIGHT AS STORMS MOVE ACROSS THE AREA THROUGH
THE OVERNIGHT HOURS.
VERY UNSTABLE AIR MASS AND EXPECT SOME OF THESE STORMS TO BECOME
SEVERE. HOWEVER THE BIGGEST THREAT WILL BE THE HEAVY RAINFALL AND
POSSIBLE FLASH FLOODING. AIR MASS REMAINS VERY MOIST THROUGH A
DEEP DEPTH. WHERE THE THREAT FOR HEAVY RAINFALL MATCHES UP WITH
WHERE HEAVY RAINFALL/SOME FLASH FLOODING OCCURRED LAST NIGHT/EARLY
THIS MORNING IS OVER THE SOUTHERN HALF OF THE AREA. THEREFORE A
FLASH FLOOD WATCH HAS BEEN ISSUED THROUGH TONIGHT.
VERY LIGHT LINGERING RAINFALL MAY BE AROUND THROUGH MID MORNING.
AFTER THAT IT SHOULD STAY QUIET UNTIL MID AFTERNOON. WEST TO
NORTHWEST FLOW ALOFT WITH ANOTHER SHORTWAVE TROUGH TO MOVE
THROUGH. AIR MASS DOES NOT APPEAR AS MOIST. ALSO SURFACE BOUNDARY
LOOKS TO BE SOUTH OF AREA. MODELS ARE NOT VERY EXCITED ABOUT THE
AFTERNOON RAINFALL CHANCES. HOWEVER CONSIDERING THE RESIDUAL
MOISTURE IN PLACE AND A SHORTWAVE TROUGH IN A WEST TO NORTHWEST
FLOW ALOFT...AM KEEPING SLIGHT TO CHANCE POPS FOR NOW.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 157 AM MDT SUN JUL 19 2015
FOR THE LONG TERM...THE GFS AND EUROPEAN ARE FINALLY STARTING TO COME
INTO AGREEMENT. THE STRONG UPPER LEVEL RIDGE THAT HAS BEEN MOVING WEST
OVER THE SOUTHERN STATES ALL WEEK HAS ITS RIDGE PEAK SITTING OVER THE
HIGH PLAINS AT 12Z WEDNESDAY. THE BEST AND ONLY SIGNIFICANT CHANCE FOR
PRECIP DURING THE LONG TERM IS WEDNESDAY 12Z THROUGH 06Z THURSDAY.
THERE IS SURFACE MOISTURE BEING PULLED UP FROM THE SOUTHWEST MONSOON AS
WELL AS SOME UPPER LEVEL SHORTWAVES THAT PASS OVER THE CWA. AFTER
THIS...PRECIP CHANCES DECLINE DUE TO THE RIDGE PUSHING FURTHER WEST AND
GAINING STRENGTH. FRIDAY AND SATURDAY LOOK TO BE DRIER AND WARMER THEN
THE OTHER DAYS IN THE LONG TERM DUE TO THE STRONG HIGH PRESSURE. THERE
IS A LOW PRESSURE THAT STARTS TO PUSH DOWN INTO THE NORTHWEST STATES
WEDNESDAY BUT JUST GETS PULLED INTO THE NORTHERN UPPER LEVEL FLOW
BECAUSE THE HIGH PRESSURE SHOWS TO BE TOO STRONG TO PENETRATE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1143 AM MDT SUN JUL 19 2015
SIMILAR SETUP TO LAST NIGHTS ROUND OF THUNDERSTORMS. AT THIS TIME
IT LOOKS LIKE THUNDERSTORMS WILL START A LITTLE EARLIER. THE
STORMS LOOK A LITTLE FURTHER SOUTH THAN THEY DID LAST NIGHT. KGLD
STILL LOOKS LIKE THE BEST CHANCE TO BE AFFECTED BY THE
THUNDERSTORMS. SO CHOSE TO PUT VCTS AT KGLD AT 21Z WITH A
PREVAILING THUNDERSTORM FORECAST FROM 00Z TO 04Z. AT THIS TIME FOR
KGLD KEPT CONDITIONS AT VFR FOR THE ENTIRE TIME BUT IF A STRONG
STORM MOVES ACROSS THEN MVFR CONDITIONS WILL BE POSSIBLE.
ADDITIONAL THUNDERSTORMS ARE POSSIBLE TOMORROW AFTERNOON BUT CHOSE
TO KEEP ANY THUNDERSTORM MENTION OUT OF THE TAF.
DO NOT FEEL AS CONFIDENT ABOUT KMCK GETTING THUNDERSTORMS BUT IT
WILL BE CLOSE. CHOSE TO PUT IN VCTS THERE FROM 01Z TO 05Z. VFR
CONDITIONS ARE EXPECTED THROUGH THE ENTIRE TIME. ALSO KEPT ANY
MENTION THUNDERSTORMS OUT FOR MONDAY AFTERNOON AT THIS TIME.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR KSZ013>016-027>029-
041-042.
CO...FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR COZ091-092.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...CLT
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
829 PM EDT Mon Jul 20 2015
...Forecast Update...
Issued at 825 PM EDT Mon Jul 20 2015
Made some minor tweaks to precip chances and hourly temps/dewpts
overnight. Overall though the forecast was in good shape. The
current line of convection stretching from central IN to southern MO
is progged to push eastward through our area between roughly 9pm to
4am. A few cells have popped up in the Bluegrass region also. With
decent CAPE/DCAPE values over the region and around 30 kts of bulk
shear, storms will pose a damaging wind threat initially. Storms
are beginning to become more clustered in nature to our west with an
increasing risk for training cells and flash flooding. The best
spots for svr convection look to be over south central KY and the
Bluegrass where the best bubbles of instability exist. However,
instability will be waning as we go through the evening hours. Of
greater concern overnight may be the flash flood threat as slow
moving storm clusters move through the area.
.SHORT TERM (Now through Tuesday Night)...
Issued at 315 PM EDT Mon Jul 20 2015
Plenty of debris cloudiness overhead as a result of convection that
affected western Kentucky early this morning. Within the last hour
we have seen storms develop where the old outflow boundary is
interacting with the Cumberland Escarpment, but these storms are
already pushing onto the Plateau as we speak. Main challenge is
timing and impact of the round, or rounds of storms that could
affect mainly central Kentucky through tonight.
Even the hi-res models seem to really be struggling from one run to
the next, so this is quite a low-confidence forecast. A couple of
weak swirls were apparent in visible imagery over southern Illinois
and western Kentucky, but even this juicy environment is not
responding yet. Earlier HRRR runs have seemed to be the only models
with any handle on initial conditions, and have hinted that one
round of convection could come through in the hours just before
sunset, with others keying on the actual front which would arrive
around midnight. Less confident in the SPC slight risk as progged
DCAPE is well out of sync with current analysis, and the effective
source of lift remains unclear. Best chance is from roughly 22Z to
05Z Tue, but not likely to affect that entire time period.
Even with the low-confidence forecast, any storms that do develop
could be prolific rain producers due to high precipitable water and
storm motion parallel to a nearly stationary boundary. Flash Flood
Guidance is quite low especially across the Bluegrass, where 1-hr
FFG is 1.5 inches or less in many places. Therefore will continue
with the Flash Flood Watch until Tuesday morning, but no extension
is planned unless convective trends show themselves more clearly.
Whatever organized storms we see should clear the area around
midnight or not too long after. Wind shift arrives by mid-morning,
but we`ll hang on to high dewpoints and chance POPs through the day
as fropa seems to occur in pieces. Mid-level WNW winds picking up to
around 30 kt could support a few strong storms with gusty winds over
east-central KY, but organized SVR potential is farther north and
east as our precip chances will be diminishing as the afternoon
progresses. Chance POPs in the middle of the day will be dropping
off by mid/late afternoon, with only south central KY in a slight
chance for storms for Tue night. Drier air will be filtering in,
with dewpoints dropping into the lower/mid 60s and temps dropping to
the upper 60s/near 70.
.LONG TERM (Wednesday through Monday)...
Issued at 300 PM EDT Mon Jul 20 2015
The synoptic pattern at the start of the long term period will
feature generally northwest flow across the Ohio Valley, as ridging
over the south-central CONUS remains in place. This ridging will
actually build NNE into the region by this weekend, bringing a
return to the hot and humid conditions.
A weak frontal boundary will have pushed into TN at the start of the
long term period. There is some discrepancy in the guidance as to
how far south this boundary will get, which will be the deciding
factor as to whether or not southern KY ends up dry. For now, will
continue with slight chance pops across southern KY Wednesday into
Thursday as impulses riding along this boundary may be enough to
bring precip into the region, but suspect most will end up dry.
Given the majority of the region will be on the northern side of the
front, temperatures and humidity values will be rather comfortable.
Look for highs in the low to mid 80s with dewpoints in the low to
mid 60s, perhaps pushing into the upper 60s over southern KY.
Heading into Friday and through the upcoming weekend, upper-level
ridging will build back into the Ohio Valley which will bring
increasing heat and humidity. The region will still be on the
periphery of the mid-level westerlies/northwesterlies, so cannot
completely rule out thunderstorm chances this weekend. It appears
the best chance for a disturbance to impact the region may come
Saturday night into Sunday, but confidence in that scenario is quite
low and does not warrant any higher mention than just slight chance
to chance POPs (20-30%). Otherwise, it will be hot and humid as
upper-level ridging builds in and 850mb temps rise back to near
20C. Look for highs back in the upper 80s and lower 90s with heat
indices from 95-100 degrees at times.
&&
.AVIATION (00Z TAF Update)...
Updated 720 PM EDT Mon Jul 20 2015
The main TAF updates with this package are delaying the timing of
t-storms this evening and adding an MVFR group for tomorrow
morning. A broken line of convection was firing to our west from
central IN to southern MO as of 23Z. Expect this line to continue
to move east through the evening hours. The latest SPC HRRR has a
good handle on the line so used that model for timing. This should
put the best t-storm chances at SDF/BWG between 2-7Z and at LEX
between 4-9Z respectively. Since it is a broken line and
strength/coverage of storms is expected to wane a bit by late
evening, still went with VCTS at all TAF sites. Will need to amend
with predominant t-storms and reduced flight conditions if the
storms hold together.
After the convection moves through tonight, we should see a period
of MVFR flight conditions before a sfc front moves through between
13-15Z. The front will shift winds from WSW to NW. After the front
passes, low clouds should scour out and lift.
Late in the day tomorrow a second sfc boundary will approach the
region bringing isolated convection. Will include a VCSH to account
for this late in the TAF period. This front will shift winds from
NW to N at the end of the TAF period or just beyond.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FLASH FLOOD WATCH until 8 AM EDT /7 AM CDT/ Tuesday FOR
KYZ029>043-045>049-054>057-065>067-077-078-081-082.
IN...FLASH FLOOD WATCH until 8 AM EDT Tuesday FOR INZ078-079-091-092.
&&
$$
Update.........AMS
Short Term.....RAS
Long Term......KJD
Aviation.......AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
725 PM EDT Mon Jul 20 2015
...Updated Aviation Discussion...
.SHORT TERM (Now through Tuesday Night)...
Issued at 315 PM EDT Mon Jul 20 2015
Plenty of debris cloudiness overhead as a result of convection that
affected western Kentucky early this morning. Within the last hour
we have seen storms develop where the old outflow boundary is
interacting with the Cumberland Escarpment, but these storms are
already pushing onto the Plateau as we speak. Main challenge is
timing and impact of the round, or rounds of storms that could
affect mainly central Kentucky through tonight.
Even the hi-res models seem to really be struggling from one run to
the next, so this is quite a low-confidence forecast. A couple of
weak swirls were apparent in visible imagery over southern Illinois
and western Kentucky, but even this juicy environment is not
responding yet. Earlier HRRR runs have seemed to be the only models
with any handle on initial conditions, and have hinted that one
round of convection could come through in the hours just before
sunset, with others keying on the actual front which would arrive
around midnight. Less confident in the SPC slight risk as progged
DCAPE is well out of sync with current analysis, and the effective
source of lift remains unclear. Best chance is from roughly 22Z to
05Z Tue, but not likely to affect that entire time period.
Even with the low-confidence forecast, any storms that do develop
could be prolific rain producers due to high precipitable water and
storm motion parallel to a nearly stationary boundary. Flash Flood
Guidance is quite low especially across the Bluegrass, where 1-hr
FFG is 1.5 inches or less in many places. Therefore will continue
with the Flash Flood Watch until Tuesday morning, but no extension
is planned unless convective trends show themselves more clearly.
Whatever organized storms we see should clear the area around
midnight or not too long after. Wind shift arrives by mid-morning,
but we`ll hang on to high dewpoints and chance POPs through the day
as fropa seems to occur in pieces. Mid-level WNW winds picking up to
around 30 kt could support a few strong storms with gusty winds over
east-central KY, but organized SVR potential is farther north and
east as our precip chances will be diminishing as the afternoon
progresses. Chance POPs in the middle of the day will be dropping
off by mid/late afternoon, with only south central KY in a slight
chance for storms for Tue night. Drier air will be filtering in,
with dewpoints dropping into the lower/mid 60s and temps dropping to
the upper 60s/near 70.
.LONG TERM (Wednesday through Monday)...
Issued at 300 PM EDT Mon Jul 20 2015
The synoptic pattern at the start of the long term period will
feature generally northwest flow across the Ohio Valley, as ridging
over the south-central CONUS remains in place. This ridging will
actually build NNE into the region by this weekend, bringing a
return to the hot and humid conditions.
A weak frontal boundary will have pushed into TN at the start of the
long term period. There is some discrepancy in the guidance as to
how far south this boundary will get, which will be the deciding
factor as to whether or not southern KY ends up dry. For now, will
continue with slight chance pops across southern KY Wednesday into
Thursday as impulses riding along this boundary may be enough to
bring precip into the region, but suspect most will end up dry.
Given the majority of the region will be on the northern side of the
front, temperatures and humidity values will be rather comfortable.
Look for highs in the low to mid 80s with dewpoints in the low to
mid 60s, perhaps pushing into the upper 60s over southern KY.
Heading into Friday and through the upcoming weekend, upper-level
ridging will build back into the Ohio Valley which will bring
increasing heat and humidity. The region will still be on the
periphery of the mid-level westerlies/northwesterlies, so cannot
completely rule out thunderstorm chances this weekend. It appears
the best chance for a disturbance to impact the region may come
Saturday night into Sunday, but confidence in that scenario is quite
low and does not warrant any higher mention than just slight chance
to chance POPs (20-30%). Otherwise, it will be hot and humid as
upper-level ridging builds in and 850mb temps rise back to near
20C. Look for highs back in the upper 80s and lower 90s with heat
indices from 95-100 degrees at times.
&&
.AVIATION (00Z TAF Update)...
Updated 720 PM EDT Mon Jul 20 2015
The main TAF updates with this package are delaying the timing of
t-storms this evening and adding an MVFR group for tomorrow
morning. A broken line of convection was firing to our west from
central IN to southern MO as of 23Z. Expect this line to continue
to move east through the evening hours. The latest SPC HRRR has a
good handle on the line so used that model for timing. This should
put the best t-storm chances at SDF/BWG between 2-7Z and at LEX
between 4-9Z respectively. Since it is a broken line and
strength/coverage of storms is expected to wane a bit by late
evening, still went with VCTS at all TAF sites. Will need to amend
with predominant t-storms and reduced flight conditions if the
storms hold together.
After the convection moves through tonight, we should see a period
of MVFR flight conditions before a sfc front moves through between
13-15Z. The front will shift winds from WSW to NW. After the front
passes, low clouds should scour out and lift.
Late in the day tomorrow a second sfc boundary will approach the
region bringing isolated convection. Will include a VCSH to account
for this late in the TAF period. This front will shift winds from
NW to N at the end of the TAF period or just beyond.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FLASH FLOOD WATCH through Tuesday morning FOR KYZ029>043-045>049-
054>057-065>067-077-078-081-082.
IN...FLASH FLOOD WATCH through Tuesday morning FOR INZ078-079-091-092.
&&
$$
Short Term........RAS
Long Term.........KJD
Aviation..........AMS
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1227 PM CDT SUN JUL 19 2015
.UPDATE...
ISSUED AT 1227 PM CDT SUN JUL 19 2015
THE AVIATION DISCUSSION HAS BEEN UPDATED FOR THE 18Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 345 AM CDT SUN JUL 19 2015
WE DID NOT GET QUITE AS HOT AND HUMID AS EXPECTED YESTERDAY...BUT
GUIDANCE INDICATES THAT IT WILL BE A FEW DEGREES WARMER TODAY WITH
DEWPOINTS HOLDING IN THE MIDDLE 70S. FORECAST HEAT INDICES TOP OUT
AT 105-109 THROUGHOUT THE AREA THIS AFTERNOON...SO WILL KEEP THE
HEAT ADVISORY GOING FOR TODAY.
HEAT INDICES ON MONDAY ARE FORECAST TO BE 100 TO 105 OVER ALL BUT
GIBSON AND PIKE COUNTIES IN SOUTHWEST INDIANA...WHICH WOULD BE
SUFFICIENTLY UNPLEASANT TO CONTINUE THE ADVISORY FOR A FOURTH
CONSECUTIVE DAY OF 100+ HEAT INDICES. UNFORTUNATELY...THE
CONVECTIVE POTENTIAL TONIGHT AND MONDAY COULD ADVERSELY IMPACT
TEMPERATURES OVER MUCH OF THE AREA MONDAY...SO CONFIDENCE IS TOO
LOW TO EXTEND THE ADVISORY AT THIS TIME.
CONFIDENCE IS QUITE LOW IN THE CONVECTIVE DETAILS THROUGH THE
SHORT TERM PORTION OF THE FORECAST. THE HRRR HAS CONSISTENTLY BEEN
KILLING OFF THE CONVECTION TO OUR NORTHWEST BEFORE IT REACHES OUR
AREA LATER THIS MORNING. MEANWHILE...THE ARW AND NMM WRF RUNS
REALLY DO NOT SHOW ANY SIGNIFICANT COVERAGE OF CONVECTION OVER OUR
REGION THROUGH MONDAY.
THE GENERAL CONSENSUS OF ALL 00Z GUIDANCE IS TO BRING A COHERENT
COLD FRONT THROUGH THE REGION MONDAY NIGHT. WILL FOCUS THE BEST
POPS THROUGHOUT THE REGION MONDAY NIGHT WITH THE FRONTAL
PASSAGE...BUT WILL CAP POPS AT 50 PERCENT. PRIOR TO MONDAY NIGHT
WILL HAVE LESSER CHANCES FOCUSED ALONG THE I-64 CORRIDOR...AND
THEY WILL GENERALLY INCREASE FROM TODAY THROUGH MONDAY.
MONDAY AFTERNOON AND EVENING THE 00Z MODELS INCREASE THE MID AND
UPPER-LEVEL FLOW OVER THE EVANSVILLE TRI STATE AS A MID/UPPER-
LEVEL TROUGH DIVES THROUGH THE UPPER MIDWEST AND INTO THE OHIO
VALLEY. THE ASSOCIATED FORCING SEEMS TO PRECEDE THE FRONTAL
PASSAGE THROUGH OUR REGION...SO WILL HAVE 50 PERCENT POPS ALONG
I-64 MONDAY AFTERNOON.
THERE WILL BE SOME POTENTIAL FOR SEVERE WEATHER MONDAY AFTERNOON
AND EVENING GIVEN THE INCREASED FLOW ALOFT AND WHAT SHOULD STILL
BE A VERY HOT AND HUMID AIRMASS ACROSS THE REGION. DAMAGING WINDS
AND LARGE HAIL WILL BE THE PRIMARY CONCERNS. THE STORMS SHOULD BE
MOVING AT A PRETTY GOOD CLIP FOR JULY...SO HEAVY RAINFALL SHOULD
NOT BE A MAJOR CONCERN.
WILL HAVE POPS FOCUSED OVER THE SOUTHERN THIRD OF THE REGION
TUESDAY...BUT IF THE FRONT MAKES IT THROUGH MONDAY NIGHT AS
CURRENTLY FORECAST...THERE MAY NOT BE MUCH CONVECTION AT ALL LEFT
FOR TUESDAY.
HIGH TEMPERATURES WILL BE IN THE MID 90S TODAY...AND WILL FALL
BACK INTO THE UPPER 80S ON TUESDAY. THE BIG QUESTION IS HOW HOT WE
WILL BE ON MONDAY. THE APPROACHING COLD FRONT WILL LIKELY HELP
LOW-LEVEL MOISTURE POOL ACROSS OUR REGION ON MONDAY...BUT CONVECTION
AND ASSOCIATED CLOUD COVER COULD SIGNIFICANTLY IMPACT
TEMPERATURES. IF THE CONVECTION STAYS NORTH OF THE REGION
MONDAY...IT MAY END UP BEING THE MOST OPPRESSIVE DAY OF THIS HOT
STRETCH. UNFORTUNATELY...IF THE CONVECTION MOVES OVER PART OR ALL
OF THE REGION...TEMPERATURES MAY NOT BE THAT HOT AT ALL. WILL HAVE
TO TAKE A WAIT AND SEE POSTURE WITH RESPECT TO EXTENDING THE HEAT
ADVISORY.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 AM CDT SUN JUL 19 2015
THE UPPER FLOW PATTERN DURING THE LONG TERM WILL CONSIST OF WEAK
TROUGHING OVER THE EASTERN SEABOARD AND A RIDGE OVER THE PLAINS. THE
EASTERN TROUGHING WILL BRING SLIGHTLY COOLER AND LESS HUMID AIR FOR
MID WEEK. THE PLAINS RIDGE WILL EXPAND SOMEWHAT BY THE
WEEKEND...BRINGING HOTTER AND MORE HUMID AIR.
AS FAR AS THE DAILY DETAILS...
ON TUESDAY NIGHT...THERE IS A SLIGHT CHANCE OF LINGERING SHOWERS OR
STORMS ACROSS SW KENTUCKY AND SE MISSOURI NEAR THE FRONT...WHICH
WILL STALL JUST TO OUR SOUTH. LOWS WILL BE GENERALLY IN THE MID TO
UPPER 60S...EXCEPT AROUND 70 NEAR THE STALLED FRONT.
ON WEDNESDAY...IT APPEARS THE FRONT WILL BE FAR ENOUGH SOUTH TO
RESTRICT POPS TO THE TENNESSEE BORDER COUNTIES AND PARTS OF SE
MISSOURI. HIGHS WILL RANGE FROM THE LOWER 80S ALONG I-64 TO THE
UPPER 80S ALONG THE TENNESSEE BORDER.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...PRECIP CHANCES WILL
INCREASE FROM THE SOUTHWEST TO NORTHEAST AS THE FRONT WORKS ITS WAY
SLOWLY NORTHEAST AS A WARM FRONT. DEW POINTS WILL CREEP BACK UP INTO
THE LOWER AND MID 70S. THIS WILL RESULT IN WARMER OVERNIGHT
LOWS...BUT DAYTIME HIGHS WILL NOT CHANGE MUCH DUE TO CLOUDS AND
SCATTERED CONVECTION.
FRIDAY THROUGH SATURDAY...THE 500 MB RIDGE OVER THE PLAINS WILL
SLOWLY EXPAND EAST OVER OUR REGION. THERE IS STILL A SMALL CHANCE OF
STORMS AS WEAK NORTHWEST FLOW ALOFT WILL LIKELY CONTAIN EMBEDDED
WEAK SHORTWAVES OR MCV/S. HIGHS SHOULD GRADUALLY RETURN TO THE LOWER
TO MID 90S...WITH LOWS GENERALLY IN THE LOWER TO MID 70S.
&&
.AVIATION...
ISSUED AT 1227 PM CDT SUN JUL 19 2015
RIDGING ALOFT AND WARM AIR IN THE MID LEVELS SHOULD PRECLUDE THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS AT THE TAF SITES THIS
AFTERNOON AND EVENING...HOWEVER VCTS POSSIBLE AT KEVV/KOWB BETWEEN
05-13Z WITH THE PASSAGE OF AN UPPER LEVEL DISTURBANCE. WINDS WILL
EITHER BE LIGHT AND VARIABLE OR OUT OF THE SOUTHWEST TO WEST AOB
8 KNOTS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ILZ075>078-080>094.
MO...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR MOZ076-086-087-100-
107>112-114.
IN...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR INZ081-082-085>088.
KY...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KYZ001>022.
&&
$$
SHORT TERM...DRS
LONG TERM...MY
AVIATION...JP
AREA FORECAST DISCUSSION
NWS PADUCAH KY
345 AM CDT SUN JUL 19 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 345 AM CDT SUN JUL 19 2015
WE DID NOT GET QUITE AS HOT AND HUMID AS EXPECTED YESTERDAY...BUT
GUIDANCE INDICATES THAT IT WILL BE A FEW DEGREES WARMER TODAY WITH
DEWPOINTS HOLDING IN THE MIDDLE 70S. FORECAST HEAT INDICES TOP OUT
AT 105-109 THROUGHOUT THE AREA THIS AFTERNOON...SO WILL KEEP THE
HEAT ADVISORY GOING FOR TODAY.
HEAT INDICES ON MONDAY ARE FORECAST TO BE 100 TO 105 OVER ALL BUT
GIBSON AND PIKE COUNTIES IN SOUTHWEST INDIANA...WHICH WOULD BE
SUFFICIENTLY UNPLEASANT TO CONTINUE THE ADVISORY FOR A FOURTH
CONSECUTIVE DAY OF 100+ HEAT INDICES. UNFORTUNATELY...THE
CONVECTIVE POTENTIAL TONIGHT AND MONDAY COULD ADVERSELY IMPACT
TEMPERATURES OVER MUCH OF THE AREA MONDAY...SO CONFIDENCE IS TOO
LOW TO EXTEND THE ADVISORY AT THIS TIME.
CONFIDENCE IS QUITE LOW IN THE CONVECTIVE DETAILS THROUGH THE
SHORT TERM PORTION OF THE FORECAST. THE HRRR HAS CONSISTENTLY BEEN
KILLING OFF THE CONVECTION TO OUR NORTHWEST BEFORE IT REACHES OUR
AREA LATER THIS MORNING. MEANWHILE...THE ARW AND NMM WRF RUNS
REALLY DO NOT SHOW ANY SIGNIFICANT COVERAGE OF CONVECTION OVER OUR
REGION THROUGH MONDAY.
THE GENERAL CONSENSUS OF ALL 00Z GUIDANCE IS TO BRING A COHERENT
COLD FRONT THROUGH THE REGION MONDAY NIGHT. WILL FOCUS THE BEST
POPS THROUGHOUT THE REGION MONDAY NIGHT WITH THE FRONTAL
PASSAGE...BUT WILL CAP POPS AT 50 PERCENT. PRIOR TO MONDAY NIGHT
WILL HAVE LESSER CHANCES FOCUSED ALONG THE I-64 CORRIDOR...AND
THEY WILL GENERALLY INCREASE FROM TODAY THROUGH MONDAY.
MONDAY AFTERNOON AND EVENING THE 00Z MODELS INCREASE THE MID AND
UPPER-LEVEL FLOW OVER THE EVANSVILLE TRI STATE AS A MID/UPPER-
LEVEL TROUGH DIVES THROUGH THE UPPER MIDWEST AND INTO THE OHIO
VALLEY. THE ASSOCIATED FORCING SEEMS TO PRECEDE THE FRONTAL
PASSAGE THROUGH OUR REGION...SO WILL HAVE 50 PERCENT POPS ALONG
I-64 MONDAY AFTERNOON.
THERE WILL BE SOME POTENTIAL FOR SEVERE WEATHER MONDAY AFTERNOON
AND EVENING GIVEN THE INCREASED FLOW ALOFT AND WHAT SHOULD STILL
BE A VERY HOT AND HUMID AIRMASS ACROSS THE REGION. DAMAGING WINDS
AND LARGE HAIL WILL BE THE PRIMARY CONCERNS. THE STORMS SHOULD BE
MOVING AT A PRETTY GOOD CLIP FOR JULY...SO HEAVY RAINFALL SHOULD
NOT BE A MAJOR CONCERN.
WILL HAVE POPS FOCUSED OVER THE SOUTHERN THIRD OF THE REGION
TUESDAY...BUT IF THE FRONT MAKES IT THROUGH MONDAY NIGHT AS
CURRENTLY FORECAST...THERE MAY NOT BE MUCH CONVECTION AT ALL LEFT
FOR TUESDAY.
HIGH TEMPERATURES WILL BE IN THE MID 90S TODAY...AND WILL FALL
BACK INTO THE UPPER 80S ON TUESDAY. THE BIG QUESTION IS HOW HOT WE
WILL BE ON MONDAY. THE APPROACHING COLD FRONT WILL LIKELY HELP
LOW-LEVEL MOISTURE POOL ACROSS OUR REGION ON MONDAY...BUT CONVECTION
AND ASSOCIATED CLOUD COVER COULD SIGNIFICANTLY IMPACT
TEMPERATURES. IF THE CONVECTION STAYS NORTH OF THE REGION
MONDAY...IT MAY END UP BEING THE MOST OPPRESSIVE DAY OF THIS HOT
STRETCH. UNFORTUNATELY...IF THE CONVECTION MOVES OVER PART OR ALL
OF THE REGION...TEMPERATURES MAY NOT BE THAT HOT AT ALL. WILL HAVE
TO TAKE A WAIT AND SEE POSTURE WITH RESPECT TO EXTENDING THE HEAT
ADVISORY.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 AM CDT SUN JUL 19 2015
THE UPPER FLOW PATTERN DURING THE LONG TERM WILL CONSIST OF WEAK
TROUGHING OVER THE EASTERN SEABOARD AND A RIDGE OVER THE PLAINS. THE
EASTERN TROUGHING WILL BRING SLIGHTLY COOLER AND LESS HUMID AIR FOR
MID WEEK. THE PLAINS RIDGE WILL EXPAND SOMEWHAT BY THE
WEEKEND...BRINGING HOTTER AND MORE HUMID AIR.
AS FAR AS THE DAILY DETAILS...
ON TUESDAY NIGHT...THERE IS A SLIGHT CHANCE OF LINGERING SHOWERS OR
STORMS ACROSS SW KENTUCKY AND SE MISSOURI NEAR THE FRONT...WHICH
WILL STALL JUST TO OUR SOUTH. LOWS WILL BE GENERALLY IN THE MID TO
UPPER 60S...EXCEPT AROUND 70 NEAR THE STALLED FRONT.
ON WEDNESDAY...IT APPEARS THE FRONT WILL BE FAR ENOUGH SOUTH TO
RESTRICT POPS TO THE TENNESSEE BORDER COUNTIES AND PARTS OF SE
MISSOURI. HIGHS WILL RANGE FROM THE LOWER 80S ALONG I-64 TO THE
UPPER 80S ALONG THE TENNESSEE BORDER.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...PRECIP CHANCES WILL
INCREASE FROM THE SOUTHWEST TO NORTHEAST AS THE FRONT WORKS ITS WAY
SLOWLY NORTHEAST AS A WARM FRONT. DEW POINTS WILL CREEP BACK UP INTO
THE LOWER AND MID 70S. THIS WILL RESULT IN WARMER OVERNIGHT
LOWS...BUT DAYTIME HIGHS WILL NOT CHANGE MUCH DUE TO CLOUDS AND
SCATTERED CONVECTION.
FRIDAY THROUGH SATURDAY...THE 500 MB RIDGE OVER THE PLAINS WILL
SLOWLY EXPAND EAST OVER OUR REGION. THERE IS STILL A SMALL CHANCE OF
STORMS AS WEAK NORTHWEST FLOW ALOFT WILL LIKELY CONTAIN EMBEDDED
WEAK SHORTWAVES OR MCV/S. HIGHS SHOULD GRADUALLY RETURN TO THE LOWER
TO MID 90S...WITH LOWS GENERALLY IN THE LOWER TO MID 70S.
&&
.AVIATION...
ISSUED AT 1243 AM CDT SUN JUL 19 2015
THE UPPER-LEVEL HIGH WILL HOLD STRONG OVER THE REGION TODAY AND
THEN WILL BE SHUNTED TO THE SOUTH BEGINNING THIS EVENING. CANNOT
COMPLETELY RULE OUT A SHOWER OR STORM REACHING KEVV OR KOWB LATE
THIS AFTERNOON OR THIS EVENING...BUT THE PROBABILITY IS TOO LOW TO
MENTION IN THE FORECASTS AT THIS TIME. THE ONLY OTHER POTENTIAL
ISSUE IS FOG DEVELOPMENT EARLY THIS MORNING. KCGI WILL HAVE THE
BEST CHANCE OF HAVING A PERSISTENTLY CALM WIND AND FOG DEVELOPMENT.
NOT CONFIDENT ENOUGH TO ADD IT INTO THE FORECAST AT THIS TIME.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ILZ075>078-080>094.
MO...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR MOZ076-086-087-100-
107>112-114.
IN...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR INZ081-082-085>088.
KY...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KYZ001>022.
&&
$$
SHORT TERM...DRS
LONG TERM...MY
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1026 PM CDT MON JUL 20 2015
.AVIATION...
INFLUENCE OF UPPER RIDGE OVHD BRINGING ANOTHER OVERNIGHT OF VFR
SKC AND NEAR CALM TO LGT SOUTH WIND. WITH LATE EVE TEMPS STILL
WELL INTO THE 80S...DO NOT EXPECT MUCH IN WAY OF LOW CLOUDS OR ANY
FOG AGAIN TONIGHT. SCATTERED CUMULUS CLOUDS EXPECTED DURG AFTN
HOURS...ALONG WITH MOSTLY SW WINDS AROUND 5 KTS...BECMG CLEAR AND
MOSTLY CALM AGAIN AFTER 22/0Z./VII/.
&&
.PREV DISCUSSION... /ISSUED 1012 PM CDT MON JUL 20 2015/
DISCUSSION...
THE DOMINANT UPPER LEVEL RIDGE IN PLACE OVER THE SRN PLAINS/FOUR
STATE REGION HAS BEGUN TO SLIGHTLY FLATTERN THIS EVENING...AS
SHORTWAVE ENERGY HAS BEGUN TO RIDE THE NRN PERIPHERY OF THE RIDGE
OVER OK/NRN AR. THIS HAS ACTUALLY SHIFTED THE RIDGE CENTER
SLIGHTLY S INTO ECNTRL TX THIS EVENING /PER WATER VAPOR
IMAGERY/...BUT SHOULD REMAIN STOUT OVER CNTRL TX/THE LOWER MS
VALLEY THROUGH MIDWEEK BEFORE FLATTENING FURTHER. DESPITE THE
SHORTWAVE ENERGY TO OUR NW...DEEP LAYER MOISTURE REMAINS LIMITED
/PER THE OOZ KSHV RAOB/...WITH THE ONGOING SCT CONVECTION OVER
CNTRL AND NW OK AS WELL AS NCNTRL AR A BIT ELEVATED. THE AR
CONVECTION HAS SENT AN OUTFLOW BNDRY SWD ACROSS THE NRN SECTIONS
OF THE STATE THIS EVENING...WHICH HAS HELPED FIRE ADDITIONAL
ISOLATED TO SCT CONVECTION...BUT IT/S UNLIKELY THAT THIS BNDRY
WILL BE ABLE TO SHIFT FAR ENOUGH S FOR CONVECTION TO FIRE ACROSS
OUR NRN ZONES. THUS...THE POP FREE FORECAST STILL LOOKS GOOD
OVERNIGHT. HOWEVER...PER THE LATEST HRRR AND 00Z NAM RUNS...HAVE
ADDED SLIGHT CHANCE POPS TUESDAY MORNING OVER MCCURTAIN COUNTY AS
WELL AS OUR FAR NRN SW AR COUNTIES WITH THE APPROACH OF THIS
SHORTWAVE WHICH MAY TOUCH OFF ISOLATED CONVECTION.
THE MAIN STORY CONCERNS THE HEAT...WITH THE HEAT ADVISORY
VERIFYING RATHER EASILY THIS AFTERNOON. WHILE WE MAY SEE SOME
CONVECTIVE BLOWOFF...IT/S DOUBTFUL THAT IT WILL IMPACT TEMPS
FARTHER S ACROSS PORTIONS OF EXTREME SW AR/E TX/N LA...AS
SUBSIDENCE BENEATH THE DEATH RIDGE CONTINUES. THUS...HAVE EXPANDED
THE HEAT ADVISORY TO INCLUDE LITTLE RIVER AND MILLER COUNTIES IN
SW AR...AS WELL AS BOWIE/CASS/MARION/HARRISON AND PANOLA COUNTIES
IN E TX. CURRENT INDICATIONS ARE THAT DEWPOINTS MAY NOT MIX OUT
WELL OVER THESE AREAS TUESDAY AFTERNOON /AS WAS THE CASE
TODAY/...WITH HEAT INDICES REACHING/SURPASSING 105 DEGREES ONCE
AGAIN. HAVE MAINTAINED THE ADVISORY UNTIL 00Z WEDNESDAY.
FORECAST MIN TEMPS IN THE MID TO UPPER 70S STILL LOOK GOOD GIVEN
THE 02Z OBS AND THE 91 DEGREE 4 INCH SOIL TEMP AT THE WFO...WHICH
IS ACTUALLY A DEGREE WARMER THAN THIS TIME SUNDAY. THUS...THE
REMAINDER OF THE FORECAST IS ON TRACK.
ZONE UPDATE/NPW ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
PREV DISCUSSION... /ISSUED 648 PM CDT MON JUL 20 2015/
AVIATION...
UPPER LVL RIDGE REMAINS CENTERED DIRECTLY OVHD OF AREA.
THUS...EXPECT VFR SKC CONDITIONS FOR MOST OF FCST PERIOD...
EXCEPT FOR ISOLD TO SCT CUMULUS CLOUDS AROUND 4K FEET DURG AFTN
HOURS FOR MOST OF AREA. DAYTIME WINDS OF AT LEAST 5 KTS EXPECTED
FROM MAINLY THE SW ONCE AGAIN AS WELL. /VII/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 78 98 78 97 / 0 10 10 20
MLU 77 98 77 96 / 0 10 10 20
DEQ 73 95 73 94 / 10 20 20 20
TXK 76 97 77 96 / 0 10 10 20
ELD 74 97 75 96 / 0 10 10 20
TYR 78 98 78 96 / 0 10 10 10
GGG 78 98 77 97 / 0 10 10 10
LFK 74 98 76 96 / 0 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT TUESDAY FOR ARZ059-070>073.
LA...HEAT ADVISORY UNTIL 7 PM CDT TUESDAY FOR LAZ001>006-010>014-
017>022.
OK...NONE.
TX...HEAT ADVISORY UNTIL 7 PM CDT TUESDAY FOR TXZ097-112-126-138-151.
&&
$$
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1012 PM CDT MON JUL 20 2015
.DISCUSSION...
THE DOMINANT UPPER LEVEL RIDGE IN PLACE OVER THE SRN PLAINS/FOUR
STATE REGION HAS BEGUN TO SLIGHTLY FLATTERN THIS EVENING...AS
SHORTWAVE ENERGY HAS BEGUN TO RIDE THE NRN PERIPHERY OF THE RIDGE
OVER OK/NRN AR. THIS HAS ACTUALLY SHIFTED THE RIDGE CENTER
SLIGHTLY S INTO ECNTRL TX THIS EVENING /PER WATER VAPOR
IMAGERY/...BUT SHOULD REMAIN STOUT OVER CNTRL TX/THE LOWER MS
VALLEY THROUGH MIDWEEK BEFORE FLATTENING FURTHER. DESPITE THE
SHORTWAVE ENERGY TO OUR NW...DEEP LAYER MOISTURE REMAINS LIMITED
/PER THE OOZ KSHV RAOB/...WITH THE ONGOING SCT CONVECTION OVER
CNTRL AND NW OK AS WELL AS NCNTRL AR A BIT ELEVATED. THE AR
CONVECTION HAS SENT AN OUTFLOW BNDRY SWD ACROSS THE NRN SECTIONS
OF THE STATE THIS EVENING...WHICH HAS HELPED FIRE ADDITIONAL
ISOLATED TO SCT CONVECTION...BUT IT/S UNLIKELY THAT THIS BNDRY
WILL BE ABLE TO SHIFT FAR ENOUGH S FOR CONVECTION TO FIRE ACROSS
OUR NRN ZONES. THUS...THE POP FREE FORECAST STILL LOOKS GOOD
OVERNIGHT. HOWEVER...PER THE LATEST HRRR AND 00Z NAM RUNS...HAVE
ADDED SLIGHT CHANCE POPS TUESDAY MORNING OVER MCCURTAIN COUNTY AS
WELL AS OUR FAR NRN SW AR COUNTIES WITH THE APPROACH OF THIS
SHORTWAVE WHICH MAY TOUCH OFF ISOLATED CONVECTION.
THE MAIN STORY CONCERNS THE HEAT...WITH THE HEAT ADVISORY
VERIFYING RATHER EASILY THIS AFTERNOON. WHILE WE MAY SEE SOME
CONVECTIVE BLOWOFF...IT/S DOUBTFUL THAT IT WILL IMPACT TEMPS
FARTHER S ACROSS PORTIONS OF EXTREME SW AR/E TX/N LA...AS
SUBSIDENCE BENEATH THE DEATH RIDGE CONTINUES. THUS...HAVE EXPANDED
THE HEAT ADVISORY TO INCLUDE LITTLE RIVER AND MILLER COUNTIES IN
SW AR...AS WELL AS BOWIE/CASS/MARION/HARRISON AND PANOLA COUNTIES
IN E TX. CURRENT INDICATIONS ARE THAT DEWPOINTS MAY NOT MIX OUT
WELL OVER THESE AREAS TUESDAY AFTERNOON /AS WAS THE CASE
TODAY/...WITH HEAT INDICES REACHING/SURPASSING 105 DEGREES ONCE
AGAIN. HAVE MAINTAINED THE ADVISORY UNTIL 00Z WEDNESDAY.
FORECAST MIN TEMPS IN THE MID TO UPPER 70S STILL LOOK GOOD GIVEN
THE 02Z OBS AND THE 91 DEGREE 4 INCH SOIL TEMP AT THE WFO...WHICH
IS ACTUALLY A DEGREE WARMER THAN THIS TIME SUNDAY. THUS...THE
REMAINDER OF THE FORECAST IS ON TRACK.
ZONE UPDATE/NPW ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PREV DISCUSSION... /ISSUED 648 PM CDT MON JUL 20 2015/
AVIATION...
UPPER LVL RIDGE REMAINS CENTERED DIRECTLY OVHD OF AREA.
THUS...EXPECT VFR SKC CONDITIONS FOR MOST OF FCST PERIOD...
EXCEPT FOR ISOLD TO SCT CUMULUS CLOUDS AROUND 4K FEET DURG AFTN
HOURS FOR MOST OF AREA. DAYTIME WINDS OF AT LEAST 5 KTS EXPECTED
FROM MAINLY THE SW ONCE AGAIN AS WELL. /VII/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 78 98 78 97 / 0 10 10 20
MLU 77 98 77 96 / 0 10 10 20
DEQ 73 95 73 94 / 10 20 20 20
TXK 76 97 77 96 / 0 10 10 20
ELD 74 97 75 96 / 0 10 10 20
TYR 78 98 78 96 / 0 10 10 10
GGG 78 98 77 97 / 0 10 10 10
LFK 74 98 76 96 / 0 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT TUESDAY FOR ARZ059-070>073.
LA...HEAT ADVISORY UNTIL 7 PM CDT TUESDAY FOR LAZ001>006-010>014-
017>022.
OK...NONE.
TX...HEAT ADVISORY UNTIL 7 PM CDT TUESDAY FOR TXZ097-112-126-138-151.
&&
$$
15
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
127 AM CDT SUN JUL 19 2015
.DISCUSSION...
06Z TAF ISSUANCE/
&&
.AVIATION...
VFR TAF SITES TONIGHT. RADAR ACTIVITY QUIET AT THE MOMENT.
REDEVELOPMENT WILL BEGIN OVER THE COASTAL WATERS EARLY SUNDAY
MORNING AND THERE COULD BE A FEW SHOWERS OR THUNDERSTORMS DEVELOP
INLAND LATE MORNING INTO AFTERNOON. EXPECT SIMILAR HIT AND MISS
ACTIVITY SO WILL LOOK AGAIN LATER THIS MORNING TO DECIDE WHETHER
TO KEEP VCNTY OR PUT IN A TEMPO GROUP DEPENDING ON UPCOMING MODEL
UPDATES.
&&
.PREV DISCUSSION... /ISSUED 854 PM CDT SAT JUL 18 2015/
UPDATE...
ALL OF THE EARLIER CONVECTION HAS DIMINISHED AND WILL REMOVE ANY
MENTION OF POPS FOR THE REMAINDER OF THE EVENING. WILL KEEP SOME
SLIGHT CHANCE POPS FOR SHOWERS OVER THE COASTAL WATERS...MAINLY
OFF OF LOWER ACADIANA...DURING THE OVERNIGHT HOURS. STILL A MOIST
AIR MASS IN PLACE WITH LATEST SOUNDING FROM KLCH SHOWING A PWAT
AROUND 2 INCHES...PLUS MESOSCALE BOUNDARY FROM EARLIER ACTIVITY
OVER SOUTHEAST LOUISIANA MAY PUSH INTO THAT AREA...AND HELP
INTERACT WITH THE MOIST AIR MASS AND PRODUCE A FEW NOCTURNAL
SHOWERS BEFORE SUNRISE OVER THAT LOCATION. THE 19/00Z HRRR HINTS
AT THIS SCENARIO. REMAINDER OF THE FORECAST SEEMS TO BE ON TRACK.
RUA
PREV DISCUSSION... /ISSUED 648 PM CDT SAT JUL 18 2015/
DISCUSSION...
00Z TAF ISSUANCE.
AVIATION...
RADAR SHOWING AFTERNOON SHRA/TSRA DISSIPATED ACROSS THE AREA. THUS
S-SW WINDS WILL BECOME VARIABLE AT 3 KTS OR LESS...WITH VFR
EXPECTED AT ALL SITES OVERNIGHT & SUN.
DML
PREV DISCUSSION... /ISSUED 335 PM CDT SAT JUL 18 2015/
DISCUSSION...
MID-AFTERNOON SFC ANALYSIS SHOWS HIGH PRESSURE CENTERED OVER THE
CNTL GULF THIS AFTERNOON...WHILE WATER VAPOR IMAGERY SHOWS
RIDGING IN PLACE OVERHEAD. LOCAL 88DS SHOW A FEW SHOWERS/STORMS
HAVE DEVELOPED ALONG THE SEA BREEZE LAST COUPLE OF HOURS WHICH ARE
MANAGING TO PUSH SLOWLY INLAND...OTHERWISE A PARTLY CLOUDY HOT
AND MUGGY DAY CONTINUES.
NOT A LOT OF CHANGES TO THE INHERITED FORECASTS FOR THE COMING
WEEK WITH HOT AND DRY REMAINING THE PRIMARY STORIES. RIDGING ALOFT
WILL MAINTAIN A STRONG PRESENCE...ESPECIALLY OVER THE NWRN 1/2 OF
THE FORECAST AREA...AS IT REMAINS MOSTLY ANCHORED OVER ERN TX.
ACCORDINGLY FORECAST SOUNDINGS/TIME-HEIGHT SECTIONS CONTINUE TO
INDICATE MAINLY LOW-LEVEL MOISTURE LINGERING WITH MID/UPPER-LEVELS
STAYING FAIRLY DRY. PRIMARY EXCEPTION AREA CONTINUES TO BE THE
SERN ZONES WHERE BEST MOISTURE WILL REMAIN WITH LEAST INFLUENCE
FROM THE RIDGE. BETTER POPS WILL NORMALLY BE FOUND OVER THE SERN
PORTIONS OF THE FORECAST AREA THROUGH THE PERIOD THANKS TO THE
BETTER MOISTURE/LESSER CAPPING AND HELPED ALONG BY PERIODIC WEAK
WAVES PUSHING WWD ALONG THE NRN GULF...ALTHOUGH RAIN CHANCES EVEN
IN THESE FAVORED AREAS WILL BE 20 PERCENT AT BEST THROUGH THE
WEEKEND. SLIGHTLY BETTER RAIN CHANCES ARE IN THE FORECAST FOR
LATER NEXT WEEK AS THE RIDGE BEGINS TO LOSE SOME OF ITS GRIP AND
CAPPING IS PROGGED TO DIMINISH A LITTLE.
AS CAN BE EXPECTED WITH THE RIDGING AFTERNOON TEMPERATURES ARE
EXPECTED TO BE FAIRLY WARM THROUGH THE PERIOD. MAX TEMPS ACROSS
THE NRN 1/2 OF THE AREA SHOULD REACH WELL INTO THE MID 90S EACH
DAY...ALTHOUGH HIGHS IN THE LOWER/MID 90S WON`T FEEL MUCH BETTER
ACROSS THE SRN 1/2. THROW IN HIGH DEWPOINTS/RH VALUES AND APPARENT
TEMPS ARE PROGGED TO RUN IN THE 102-106 RANGE FOR MOST LOCATIONS
EACH DAY.
MARINE...
MAINLY LIGHT AND MOSTLY ONSHORE FLOW IS EXPECTED THROUGH THE
PERIOD AS HIGH PRESSURE REMAINS IN CONTROL OVER THE NRN GULF.
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 96 76 96 76 / 10 10 10 10
LCH 94 77 94 77 / 10 10 10 0
LFT 95 78 95 78 / 10 10 10 10
BPT 96 77 95 76 / 10 10 20 0
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AVIATION...06
AREA FORECAST DISCUSSION
NWS GRAY ME
1132 AM EDT SUN JUL 19 2015
.SYNOPSIS...
A WEAK COLD FRONT APPROACHING FROM THE WEST WILL PRODUCE SHOWERS
AND THUNDERSTORMS TODAY SOME WHICH MAY BE SEVERE IN NEW HAMPSHIRE
AND INTERIOR MAINE. THE COLD FRONT WILL PUSH OFFSHORE TONIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE WEST ON MONDAY. ANOTHER COLD
FRONT WILL APPROACH FROM THE WEST MONDAY NIGHT AND WILL CROSS THE
AREA ON TUESDAY WITH ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS.
HIGH PRESSURE WILL BUILD IN FROM THE WEST TUESDAY NIGHT AND
WEDNESDAY. ANOTHER COLD FRONT WILL DROP SOUTH FROM CANADA ON
THURSDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST FRIDAY AND
WILL SHIFT OFFSHORE ON SATURDAY.
&&
.NEAR TERM /TODAY/...
1130AM UPDATE...
HAVE UPDATED PRECIPITATION CHANCES AGAIN AS WELL AS FORECAST HIGH
TEMPERATURES AND DEWPOINTS. ALREADY UP TO 80 IN PORTLAND. ONSHORE
SOUTHEAST FLOW IS NOT TEMPERING WARMING MUCH THERE... WHILE TO THE
NORTH CLOUDS AND RAIN HAVE KEPT THINGS COOLER. DEWPOINTS ACROSS
THE SOUTHERN HALF OF THE AREA HAVE RISEN SOLIDLY INTO THE 70S.
JUST ABOUT ALL OF THE NORTH HALF HAS SEEN RAIN THIS MORNING. STILL
CONCERNED ABOUT POSSIBLE DEVELOPMENT OF ADDITIONAL THUNDERSTORMS
LATER THIS AFTERNOON.
1015AM UPDATE...
HAVE MADE FURTHER REFINEMENTS TO HOURLY PRECIPITATION CHANCES AS
FIRST ROUND OF REMNANT STORMS MOVES EAST AND SECOND ROUND HAS
DEVELOPED IN VERMONT AND HEADED TOWARD NEW HAMPSHIRE... A LITTLE
FURTHER SOUTH THAN THE FIRST. OTHERWISE NO SIGNIFICANT CHANGES TO
THE FORECAST.
830AM UPDATE...
HAVE UPDATED THE FORECAST TO ADJUST HOURLY PRECIPITATION CHANCES
TO BETTER REFLECT TIMING OF PRECIPITATION. USED CURRENT REGIONAL
RADAR OBSERVATIONS IN COMBINATION WITH THE HRRR MODEL IN THIS
PROCESS. INITIAL AREA OF THUNDERSTORM ACTIVITY NEAR THE
QUEBEC/VERMONT BORDER WILL CONTINUE TO MOVE EAST AND POSSIBLY
WEAKEN AS IT REACHES NEW HAMPSHIRE AND NORTHWEST MAINE THIS
MORNING. ADDITIONAL ACTIVITY COULD DEVELOP IN THE MOIST UNSTABLE
AIR MASS OVER THE REGION BUT SEEMS MORE LIKELY LATER IN THE DAY.
SEVERAL DIFFERENT ROUNDS OF THUNDERSTORMS WILL LIKELY TRACK EAST
ACROSS PARTS OF THE AREA FROM EARLY AFTERNOON THROUGH LATER IN THE
NIGHT. WIND SHEAR INCREASES THROUGH THE DAY SO SEVERE WEATHER
CHANCES WOULD CORRESPONDINGLY INCREASE WITH TIME AS WELL. THERE
WILL LIKELY BE A LOT OF COMPLEX FACTORS WHICH MAKE PINPOINTING A
PARTICULAR THREAT AREA FAIRLY DIFFICULT... OUTFLOW BOUNDARIES...
SEA BREEZE... BROADER SHORTWAVE TROUGHS... AND PRIOR CONVECTIVE
ACTIVITY. HOWEVER IT APPEARS MOST AREAS WILL GET WET AT SOME POINT
TODAY OR TONIGHT.
ORIGINAL DISCUSSION...
COLD FRONT APPROACHING FROM THE WEST TODAY WILL BE THE CATALYST
FOR SHOWERS AND THUNDERSTORMS SOME WHICH WILL LIKELY BE SEVERE.
INCREASING SHEAR AND CAPES OF 2 TO 4K AND ABUNDANT LOW LEVEL
MOISTURE WILL COME TOGETHER DURING PRIME HEATING. MAIN THREAT WILL
BE DAMAGING WINDS. WITH FREEZING LEVELS AT OR ABOVE 14KFT...HAIL
WILL BE A LESSER THREAT BUT MORE ROBUST CELLS WILL HAVE THE
POTENTIAL FOR HAIL 1 INCH OR GREATER. SPC HAS EXTENDED A SLIGHT
RISK TO INCLUDE MUCH OF NEW HAMPSHIRE AND EXTREME WESTERN MAINE
AWAY FROM THE COAST. OUTSIDE THIS AREA HAVE INCLUDED ENHANCED
WORDING FOR SMALL HAIL AND GUSTY WINDS WITH THESE STORMS.
WILL BE STEAMY DAY WITH DEW POINTS IN THE LOWER 70S AND HIGH
TEMPERATURES PUSHING 90 DEGREES ACROSS SOUTHERN NEW HAMPSHIRE AND
EXTREME SOUTHWEST MAINE. COASTAL AND INTERIOR MAINE WILL BE
SLIGHTLY COOLER WITH AN ONSHORE FLOW HOLDING HIGHS IN THE MID 70S
TO LOWER 80S.
&&
.SHORT TERM /TONIGHT AND MONDAY/...
CONVECTION MAY LAST INTO THE LATE EVENING HOURS...ESPECIALLY IN
SOUTHERN ZONES. COLD FRONT WILL FINALLY MOVE OFFSHORE AFTER
MIDNIGHT. EXPECT LOW CLOUDS AND AREAS OF FOG TO DEVELOP. LOW
TEMPERATURES WILL RANGE THROUGH THE 60S.
WEAK RIDGE OF HIGH PRESSURE WILL BUILD IN FOR MONDAY BRINGING SOME
RELIEF FROM OPPRESSIVE HUMIDITY LEVELS BUT LITTLE IN THE WAY OF
COOLER AIR. PLENTY OF SUN AND WESTERLY FLOW WILL PUSH HIGHS INTO
THE 80S TO NEAR 90 THROUGH MOST OF THE FORECAST AREA.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ANOTHER SHORT WAVE TROUGH WILL APPROACH THE REGION FROM THE
NORTHWEST MONDAY NIGHT AND MOVE ACROSS WITH AN ATTENDANT SURFACE
COLD FRONT TUESDAY. THIS WILL AID IN POTENTIALLY ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TUESDAY. THEREAFTER...PERSISTENT UPPER
LEVEL LOW PRESSURE ACROSS NORTHERN MAINE AND QUEBEC SHOULD KEEP
THE HEAT AND HUMIDITY AWAY...ALONG WITH A CHANCE FOR DIURNAL
SHOWERS AND ISOLATED THUNDERSTORMS FROM TIME TO TIME...ESPECIALLY
IN THE MOUNTAINS THROUGH EARLY NEXT WEEKEND.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...VFR TODAY WITH AREAS OF IFR/LIFR CEILINGS AND VSBY
IN SHOWERS AND THUNDERSTORMS.AREAS OF IFR/LIFR CEILINGS AND VSBY
OVERNIGHT....BECOMING VFR ON MONDAY.
LONG TERM...IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS ON TUESDAY
INTO TUESDAY EVENING FOLLOWED BY MAINLY VFR CONDITIONS WEDNESDAY
THROUGH FRIDAY.
&&
.MARINE...
SHORT TERM...NO FLAGS. WINDS WILL BE BRIEFLY STRONG AND GUSTY IN
AND NEAR AFTERNOON AND EVENING THUNDERSTORMS.
LONG TERM...SUB-SCA CONDITIONS ARE CURRENTLY EXPECTED MONDAY NIGHT
THROUGH FRIDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM UPDATE... KIMBLE
AREA FORECAST DISCUSSION
NWS GRAY ME
1015 AM EDT SUN JUL 19 2015
.SYNOPSIS...
A WEAK COLD FRONT APPROACHING FROM THE WEST WILL PRODUCE SHOWERS
AND THUNDERSTORMS TODAY SOME WHICH MAY BE SEVERE IN NEW HAMPSHIRE
AND INTERIOR MAINE. THE COLD FRONT WILL PUSH OFFSHORE TONIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE WEST ON MONDAY. ANOTHER COLD
FRONT WILL APPROACH FROM THE WEST MONDAY NIGHT AND WILL CROSS THE
AREA ON TUESDAY WITH ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS.
HIGH PRESSURE WILL BUILD IN FROM THE WEST TUESDAY NIGHT AND
WEDNESDAY. ANOTHER COLD FRONT WILL DROP SOUTH FROM CANADA ON
THURSDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST FRIDAY AND
WILL SHIFT OFFSHORE ON SATURDAY.
&&
.NEAR TERM /TODAY/...
1015AM UPDATE...
HAVE MADE FURTHER REFINEMENTS TO HOURLY PRECIPITATION CHANCES AS
FIRST ROUND OF REMNANT STORMS MOVES EAST AND SECOND ROUND HAS
DEVELOPED IN VERMONT AND HEADED TOWARD NEW HAMPSHIRE... A LITTLE
FURTHER SOUTH THAN THE FIRST. OTHERWISE NO SIGNIFICANT CHANGES TO
THE FORECAST.
830AM UPDATE...
HAVE UPDATED THE FORECAST TO ADJUST HOURLY PRECIPITATION CHANCES
TO BETTER REFLECT TIMING OF PRECIPITATION. USED CURRENT REGIONAL
RADAR OBSERVATIONS IN COMBINATION WITH THE HRRR MODEL IN THIS
PROCESS. INITIAL AREA OF THUNDERSTORM ACTIVITY NEAR THE
QUEBEC/VERMONT BORDER WILL CONTINUE TO MOVE EAST AND POSSIBLY
WEAKEN AS IT REACHES NEW HAMPSHIRE AND NORTHWEST MAINE THIS
MORNING. ADDITIONAL ACTIVITY COULD DEVELOP IN THE MOIST UNSTABLE
AIR MASS OVER THE REGION BUT SEEMS MORE LIKELY LATER IN THE DAY.
SEVERAL DIFFERENT ROUNDS OF THUNDERSTORMS WILL LIKELY TRACK EAST
ACROSS PARTS OF THE AREA FROM EARLY AFTERNOON THROUGH LATER IN THE
NIGHT. WIND SHEAR INCREASES THROUGH THE DAY SO SEVERE WEATHER
CHANCES WOULD CORRESPONDINGLY INCREASE WITH TIME AS WELL. THERE
WILL LIKELY BE A LOT OF COMPLEX FACTORS WHICH MAKE PINPOINTING A
PARTICULAR THREAT AREA FAIRLY DIFFICULT... OUTFLOW BOUNDARIES...
SEA BREEZE... BROADER SHORTWAVE TROUGHS... AND PRIOR CONVECTIVE
ACTIVITY. HOWEVER IT APPEARS MOST AREAS WILL GET WET AT SOME POINT
TODAY OR TONIGHT.
ORIGINAL DISCUSSION...
COLD FRONT APPROACHING FROM THE WEST TODAY WILL BE THE CATALYST
FOR SHOWERS AND THUNDERSTORMS SOME WHICH WILL LIKELY BE SEVERE.
INCREASING SHEAR AND CAPES OF 2 TO 4K AND ABUNDANT LOW LEVEL
MOISTURE WILL COME TOGETHER DURING PRIME HEATING. MAIN THREAT WILL
BE DAMAGING WINDS. WITH FREEZING LEVELS AT OR ABOVE 14KFT...HAIL
WILL BE A LESSER THREAT BUT MORE ROBUST CELLS WILL HAVE THE
POTENTIAL FOR HAIL 1 INCH OR GREATER. SPC HAS EXTENDED A SLIGHT
RISK TO INCLUDE MUCH OF NEW HAMPSHIRE AND EXTREME WESTERN MAINE
AWAY FROM THE COAST. OUTSIDE THIS AREA HAVE INCLUDED ENHANCED
WORDING FOR SMALL HAIL AND GUSTY WINDS WITH THESE STORMS.
WILL BE STEAMY DAY WITH DEW POINTS IN THE LOWER 70S AND HIGH
TEMPERATURES PUSHING 90 DEGREES ACROSS SOUTHERN NEW HAMPSHIRE AND
EXTREME SOUTHWEST MAINE. COASTAL AND INTERIOR MAINE WILL BE
SLIGHTLY COOLER WITH AN ONSHORE FLOW HOLDING HIGHS IN THE MID 70S
TO LOWER 80S.
&&
.SHORT TERM /TONIGHT AND MONDAY/...
CONVECTION MAY LAST INTO THE LATE EVENING HOURS...ESPECIALLY IN
SOUTHERN ZONES. COLD FRONT WILL FINALLY MOVE OFFSHORE AFTER
MIDNIGHT. EXPECT LOW CLOUDS AND AREAS OF FOG TO DEVELOP. LOW
TEMPERATURES WILL RANGE THROUGH THE 60S.
WEAK RIDGE OF HIGH PRESSURE WILL BUILD IN FOR MONDAY BRINGING SOME
RELIEF FROM OPPRESSIVE HUMIDITY LEVELS BUT LITTLE IN THE WAY OF
COOLER AIR. PLENTY OF SUN AND WESTERLY FLOW WILL PUSH HIGHS INTO
THE 80S TO NEAR 90 THROUGH MOST OF THE FORECAST AREA.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ANOTHER SHORT WAVE TROUGH WILL APPROACH THE REGION FROM THE
NORTHWEST MONDAY NIGHT AND MOVE ACROSS WITH AN ATTENDANT SURFACE
COLD FRONT TUESDAY. THIS WILL AID IN POTENTIALLY ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TUESDAY. THEREAFTER...PERSISTENT UPPER
LEVEL LOW PRESSURE ACROSS NORTHERN MAINE AND QUEBEC SHOULD KEEP
THE HEAT AND HUMIDITY AWAY...ALONG WITH A CHANCE FOR DIURNAL
SHOWERS AND ISOLATED THUNDERSTORMS FROM TIME TO TIME...ESPECIALLY
IN THE MOUNTAINS THROUGH EARLY NEXT WEEKEND.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...VFR TODAY WITH AREAS OF IFR/LIFR CEILINGS AND VSBY
IN SHOWERS AND THUNDERSTORMS.AREAS OF IFR/LIFR CEILINGS AND VSBY
OVERNIGHT....BECOMING VFR ON MONDAY.
LONG TERM...IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS ON TUESDAY
INTO TUESDAY EVENING FOLLOWED BY MAINLY VFR CONDITIONS WEDNESDAY
THROUGH FRIDAY.
&&
.MARINE...
SHORT TERM...NO FLAGS. WINDS WILL BE BRIEFLY STRONG AND GUSTY IN
AND NEAR AFTERNOON AND EVENING THUNDERSTORMS.
LONG TERM...SUB-SCA CONDITIONS ARE CURRENTLY EXPECTED MONDAY NIGHT
THROUGH FRIDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM UPDATE... KIMBLE
AREA FORECAST DISCUSSION
NWS GRAY ME
830 AM EDT SUN JUL 19 2015
.SYNOPSIS...
A WEAK COLD FRONT APPROACHING FROM THE WEST WILL PRODUCE SHOWERS
AND THUNDERSTORMS TODAY SOME WHICH MAY BE SEVERE IN NEW HAMPSHIRE
AND INTERIOR MAINE. THE COLD FRONT WILL PUSH OFFSHORE TONIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE WEST ON MONDAY. ANOTHER COLD
FRONT WILL APPROACH FROM THE WEST MONDAY NIGHT AND WILL CROSS THE
AREA ON TUESDAY WITH ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS.
HIGH PRESSURE WILL BUILD IN FROM THE WEST TUESDAY NIGHT AND
WEDNESDAY. ANOTHER COLD FRONT WILL DROP SOUTH FROM CANADA ON
THURSDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST FRIDAY AND
WILL SHIFT OFFSHORE ON SATURDAY.
&&
.NEAR TERM /TODAY/...
830AM UPDATE...
HAVE UPDATED THE FORECAST TO ADJUST HOURLY PRECIPITATION CHANCES
TO BETTER REFLECT TIMING OF PRECIPITATION. USED CURRENT REGIONAL
RADAR OBSERVATIONS IN COMBINATION WITH THE HRRR MODEL IN THIS
PROCESS. INITIAL AREA OF THUNDERSTORM ACTIVITY NEAR THE
QUEBEC/VERMONT BORDER WILL CONTINUE TO MOVE EAST AND POSSIBLY
WEAKEN AS IT REACHES NEW HAMPSHIRE AND NORTHWEST MAINE THIS
MORNING. ADDITIONAL ACTIVITY COULD DEVELOP IN THE MOIST UNSTABLE
AIR MASS OVER THE REGION BUT SEEMS MORE LIKELY LATER IN THE DAY.
SEVERAL DIFFERENT ROUNDS OF THUNDERSTORMS WILL LIKELY TRACK EAST
ACROSS PARTS OF THE AREA FROM EARLY AFTERNOON THROUGH LATER IN THE
NIGHT. WIND SHEAR INCREASES THROUGH THE DAY SO SEVERE WEATHER
CHANCES WOULD CORRESPONDINGLY INCREASE WITH TIME AS WELL. THERE
WILL LIKELY BE A LOT OF COMPLEX FACTORS WHICH MAKE PINPOINTING A
PARTICULAR THREAT AREA FAIRLY DIFFICULT... OUTFLOW BOUNDARIES...
SEA BREEZE... BROADER SHORTWAVE TROUGHS... AND PRIOR CONVECTIVE
ACTIVITY. HOWEVER IT APPEARS MOST AREAS WILL GET WET AT SOME POINT
TODAY OR TONIGHT.
ORIGINAL DISCUSSION...
COLD FRONT APPROACHING FROM THE WEST TODAY WILL BE THE CATALYST
FOR SHOWERS AND THUNDERSTORMS SOME WHICH WILL LIKELY BE SEVERE.
INCREASING SHEAR AND CAPES OF 2 TO 4K AND ABUNDANT LOW LEVEL
MOISTURE WILL COME TOGETHER DURING PRIME HEATING. MAIN THREAT WILL
BE DAMAGING WINDS. WITH FREEZING LEVELS AT OR ABOVE 14KFT...HAIL
WILL BE A LESSER THREAT BUT MORE ROBUST CELLS WILL HAVE THE
POTENTIAL FOR HAIL 1 INCH OR GREATER. SPC HAS EXTENDED A SLIGHT
RISK TO INCLUDE MUCH OF NEW HAMPSHIRE AND EXTREME WESTERN MAINE
AWAY FROM THE COAST. OUTSIDE THIS AREA HAVE INCLUDED ENHANCED
WORDING FOR SMALL HAIL AND GUSTY WINDS WITH THESE STORMS.
WILL BE STEAMY DAY WITH DEW POINTS IN THE LOWER 70S AND HIGH
TEMPERATURES PUSHING 90 DEGREES ACROSS SOUTHERN NEW HAMPSHIRE AND
EXTREME SOUTHWEST MAINE. COASTAL AND INTERIOR MAINE WILL BE
SLIGHTLY COOLER WITH AN ONSHORE FLOW HOLDING HIGHS IN THE MID 70S
TO LOWER 80S.
&&
.SHORT TERM /TONIGHT AND MONDAY/...
CONVECTION MAY LAST INTO THE LATE EVENING HOURS...ESPECIALLY IN
SOUTHERN ZONES. COLD FRONT WILL FINALLY MOVE OFFSHORE AFTER
MIDNIGHT. EXPECT LOW CLOUDS AND AREAS OF FOG TO DEVELOP. LOW
TEMPERATURES WILL RANGE THROUGH THE 60S.
WEAK RIDGE OF HIGH PRESSURE WILL BUILD IN FOR MONDAY BRINGING SOME
RELIEF FROM OPPRESSIVE HUMIDITY LEVELS BUT LITTLE IN THE WAY OF
COOLER AIR. PLENTY OF SUN AND WESTERLY FLOW WILL PUSH HIGHS INTO
THE 80S TO NEAR 90 THROUGH MOST OF THE FORECAST AREA.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
ANOTHER SHORT WAVE TROUGH WILL APPROACH THE REGION FROM THE
NORTHWEST MONDAY NIGHT AND MOVE ACROSS WITH AN ATTENDANT SURFACE
COLD FRONT TUESDAY. THIS WILL AID IN POTENTIALLY ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS TUESDAY. THEREAFTER...PERSISTENT UPPER
LEVEL LOW PRESSURE ACROSS NORTHERN MAINE AND QUEBEC SHOULD KEEP
THE HEAT AND HUMIDITY AWAY...ALONG WITH A CHANCE FOR DIURNAL
SHOWERS AND ISOLATED THUNDERSTORMS FROM TIME TO TIME...ESPECIALLY
IN THE MOUNTAINS THROUGH EARLY NEXT WEEKEND.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...VFR TODAY WITH AREAS OF IFR/LIFR CEILINGS AND VSBY
IN SHOWERS AND THUNDERSTORMS.AREAS OF IFR/LIFR CEILINGS AND VSBY
OVERNIGHT....BECOMING VFR ON MONDAY.
LONG TERM...IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS ON TUESDAY
INTO TUESDAY EVENING FOLLOWED BY MAINLY VFR CONDITIONS WEDNESDAY
THROUGH FRIDAY.
&&
.MARINE...
SHORT TERM...NO FLAGS. WINDS WILL BE BRIEFLY STRONG AND GUSTY IN
AND NEAR AFTERNOON AND EVENING THUNDERSTORMS.
LONG TERM...SUB-SCA CONDITIONS ARE CURRENTLY EXPECTED MONDAY NIGHT
THROUGH FRIDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
NEAR TERM UPDATE... KIMBLE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
306 PM EDT SUN JUL 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EDT SUN JUL 19 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STRONG SHRTWV
MOVING ENEWD THRU NW ONTARIO TO THE N OF UPR LVL RDG CENTERED OVER
THE SRN PLAINS. SFC COLD FNT ASSOCIATED WITH THE SHRTWV IS MOVING
THRU UPR MI EARLY THIS MRNG. DESPITE SOME FAIRLY HI MUCAPES FOR
EARLY IN THE MRNG...AS HI AS 1500-2000 J/KG...THERE HAVE BEEN ONLY
ISOLD SHRA/TS ALONG THE FNT/COMMA TAIL OF ONTARIO SHRTWV DUE TO
DRY/CAPPED MID LVLS DEPICTED ON THE 00Z GRB/RAOB AND RUC ANALYSIS
SDNGS AS WELL AS PASSAGE OF THIS FEATURE DURING PERIOD OF NOCTURNAL
COOLING. SOME GUSTY W WINDS HAVE DVLPD OVER WRN UPR MI IN THE WAKE
OF THE SFC COLD FROPA. THE 00Z INL RAOB SHOWED W WINDS AOA 30 KTS AS
LO AS 1K FT AGL WITH FAIRLY STEEP SFC-H7 LAPSE RATES BLO SHARP MID
LVL INVRN ASSOCIATED WITH DNVA/LARGER SCALE QVECTOR DVGC AND
SUBSIDENCE LEFT IN THE WAKE OF ONTARIO SHRTWV. LOOKING FARTHER
UPSTREAM...THERE IS ANOTHER SHRTWV DIGGING SEWD IN SASKATCHEWAN.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE ON GUSTY W WINDS TODAY.
TODAY...EXPECT ANY LINGERING SHRA/TS TO END BY ARND FCST ISSUANCE
WITH PASSAGE OF SFC COLD FNT TO THE E AND ARRIVAL OF DEEP LYR
QVECTOR DVGC/SUBSIDENCE. FOLLOWING THE FROPA...SHARP PRES GRADIENT
BTWN DEPARTING SHRTWV/SFC LO MOVING TOWARD HUDSON BAY AND SFC HI
PRES MOVING E THRU THE NCENTRL PLAINS IS FCST TO DOMINATE THE CWA.
WITH H925 WINDS AS HI AS 25-30 KTS AND DIURNAL HEATING WITH A GOOD
DEAL OF SUNSHINE CONTRIBUTING TO WELL MIXED LLVL LAPSE RATES/SOME
DIURNAL CU...EXPECT SOME GUSTY WINDS. THE STRONGEST WINDS ARE MOST
LIKELY OVER THE EXPOSED KEWEENAW PENINSULA...WHERE LK BREEZE
CONTRIBUTION WL AID THE GUSTY WINDS TO 30-35 MPH. WITH H85 TEMPS
NEAR 14-15C THIS AFTN AND DEEP MIXING...EXPECT HI TEMPS TO RISE INTO
THE 80S TOWARD THE HI END OF GUIDANCE AWAY FM LK MODERATION.
TNGT...LINGERING GUSTY WINDS WL DIMINISH IN THE EVNG WITH LOSS OF
DAYTIME HEATING. THEN SHRTWV NOW MOVING INTO SASKATCHEWAN IS FCST TO
SLIDE SEWD THRU NW ONTARIO. SINCE BULK OF THE DPVA/DEEP LYR
FORCING/MID LVL MOISTENING IS PROGGED TO REMAIN TO THE N AND MSTR
INFLOW WL BE LIMITED BY PREVAILING W WIND DURING PERIOD OF NOCTURNAL
COOLING...ALMOST ALL OF THE SHORT TERM MODELS INDICATE THE PCPN WL
REMAIN TO THE N OF THE LAND CWA. THE NAM DOES SHOW SOME SHOWERS
BRUSHING THE KEWEENAW PENINSULA. WITH STEADY WSW SFC WINDS...THE
DIURNAL FALL OF TEMP WL BE GREATLY REDUCED. THE WARMER DOWNSLOPE
LOCATIONS NEAR LK SUP WL SEE MIN TEMPS HOLD ARND 65.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 305 PM EDT SUN JUL 19 2015
LARGE SCALE TROUGHING STARTING THE LONG TERM OVER ONTARIO/QUEBEC AND
THE GREAT LAKES SLOWLY MOVES EAST BY LATE WEEK. IN RESPONSE THE
RIDGING ALOFT OVER THE NORTHWEST CONUS WILL BUILD INTO SCNTRL CANADA
AND THE GREAT LAKES. TROUGHING THEN BEGINS TO BEAT DOWN THE RIDGE
FRIDAY INTO NEXT WEEKEND WHICH SHOULD BRING CHANCE OF SHRA/TSRA BACK
OVER THE UPPER GREAT LAKES AT LEAST BRIEFLY. NORTHWEST FLOW ALOFT
THROUGH MID WEEK BTWN DEPARTING TROUGH AND INCOMING RIDGE MAY TRIP
OFF ISOLD SHRA DURING PEAK HEATING OF THE AFTN..BUT CHANCES ARE NOT
HIGH ENOUGH TO INCLUDE ATTM. SINCE GFS/ECMWF SHOW ML MUCAPE VALUES
STAYING WELL TO SW AND S OF UPR MICHIGAN AND WINDS IN CLOUD BEARING
LAYER ARE FM NW...EXPECT ANY TSRA TO STAY AWAY FM UPR MICHIGAN. DUE
TO THE LINGERING TROUGHING...TEMPS TUESDAY AND WEDNESDAY WILL BE A
BIT BLO NORMAL...ESPECIALLY ALONG LK SUPERIOR ON TUESDAY WITH
STRONGER ONSHORE WINDS.
HINTS FM GFS/ECMWF THAT RETURN FLOW H85-H7 MOISTURE ADVECTION
INTERACTING WITH ELEVATED INSTABILITY LATE WEDNESDAY INTO WEDNESDAY
NIGHT MAY SET UP AREA OF FOCUS FOR BAND OF SHRA/TSRA. MOST LIKELY
ANY SHRA OR TSRA WOULD REMAIN SOUTH OF THE CWA AS GRADIENT OF
ELEVATED CAPE PROBABLY ENDS UP TO THE SOUTH OF HERE AS IT TYPICALLY
DOES MINUS ANY STRONG DISTURBANCE MOVING THROUGH TO DRAG IT FARTHER
NORTH. ECMWF/GEM-NH SHOW RIBBON OF QPF FM CNTRL OR NORTHERN MN INTO
CNTRL WI WHILE THE GFS IS FARTHER NORTH OVER NORTHERN WI AND INTO
WESTERN UPR MICHIGAN. KEPT POPS SOUTH OF CWA ON WEDNESDAY BUT DO
HAVE SLIGHT CHANCES WED NIGHT OVER FAR WEST CWA. IS ALSO POSSIBLE
THAT THIS MECHANISM MAY HELP TRIGGER ADDITIONAL SHRA/TSRA DURING
PEAK HEATING ON THURSDAY AFTN OVER NORTHERN WI AND PERHAPS INTO
WESTERN UPR MICHIGAN. EVEN THOUGH THERE IS MORE INSTABILITY INTO
WESTERN CWA COMPARED TO PREVIOUS DAYS...H85-H3 WINDS FM NORTHWEST
WILL MOST LIKELY KEEP MAJORITY OF ANY PRECIP OVER WI DURING THE
AFTN. TEMPS WILL START WARMING TREND ON THURSDAY AFTN...WITH
READINGS INTO LOWER 80S AWAY FM THE GREAT LAKES. GFS IS MORE BULLISH
IN GENERATING QPF ON THURSDAY NIGHT OVER WESTERN UPR MICHIGAN DUE TO
THE LINGERING AREA OF H85-H7 MOISTURE ADVECTION ALONG WITH AXIS OF
ELEVATED CAPE. ECMWF SHOWS LIGHT QPF ALSO. WILL CARRY SLIGHT CHANCES.
RIDGE MOVES OVERHEAD ON FRIDAY /SO COULD SEE INCREASING CAPPING
ISSUES/. THERE ALSO IS MORE INSTABILITY WITH AFTN MLCAPES POSSIBLY
OVER 1000J/KG AS TEMPS REACH INTO THE MID OR EVEN UPR 80S. NOT OUT
OF QUESTION THERE COULD BE ISOLD SHRA/TSRA ALONG LAKE BREEZES AS THE
PRIMARY SYNOPTIC WINDS IN LOW-MID LEVELS ARE MORE FM THE WEST.
POTENTIAL WOULD BE INCREASED IF THERE IS ANY TYPE OF SHORTWAVE OR
CONVECTIVELY INDUCED WAVE SLIDING OUT AHEAD OF PRIMARY LONGWAVE
TROUGH. MAIN FOCUS FOR SHRA/TSRA FRIDAY WILL PROBABLY REMAIN WEST OF
UPR LAKES ALONG COLD FRONT TIED INTO THE LARGER TROUGH ALOFT.
STRONG JET PUNCHING INTO THE PACIFIC NORTHWEST KEEPS THE FLOW ALOFT
PROGRESSIVE WITH THE TROUGH JUST UPSTREAM OF UPR LAKES ON FRIDAY
CROSSING NORTHERN ONTARIO AND THE LK SUPERIOR REGION THROUGH
SATURDAY. COLD FRONT CROSSES THE REGION FRIDAY NIGHT INTO SATURDAY
AND THAT REPRESENTS BEST CHANCES OF SHRA/TSRA THROUGH THE LONG TERM
PERIOD. GIVEN EXPECTED INSTABILITY AND SHEAR IN THE REGION...SEVERE
WEATHER OVER SOME PARTS OF THE UPPER MISSISSIPPI RIVER VALLEY INTO
THE WESTERN GREAT LAKES SEEM FEASIBLE. NOT CLEAR WHETHER UPR
MICHIGAN WOULD BE AFFECTED THOUGH. PLENTY OF TIME TO PIN DOWN
DETAILS CRITICAL TO THAT ASPECT OF FORECAST WILL NO DOUBT BE
INFLUENCED BY TIMING OF SHORTWAVE/FRONT THAT IS FAR FM CERTAIN ATTM.
SIMILAR TO THIS WEEKEND...EXPECT HIGH PRESSURE TO BUILD IN FOR NEXT
SUNDAY WITH DRY WEATHER RETURNING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 151 PM EDT SUN JUL 19 2015
VFR CEILINGS AND VIS WILL PREVAIL THROUGH THE PERIOD. THE MAIN
THREAT WILL BE WINDS GUSTING 20-35KTS DURING THE DAYTIME HOURS...AND
LLWS AT NIGHT AS DAYTIME MIXING DIMINISHES. THIS IS ALL THANKS TO
UPPER MI BEING BETWEEN LOW PRESSURE OVER MANITOBA AND HUDSON
BAY...AND HIGH PRESSURE MOVING FROM THE CENTRAL PLAINS TO THE OHIO
VALLEY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EDT SUN JUL 19 2015TIGHT PRES GRADIENT BETWEEN LO
PRES MOVING INTO HUDSON BAY AND HI PRES MOVING THRU THE NCENTRAL
PLAINS WILL CAUSE SOME WSW WINDS AS HI AS 25 KTS THRU MON. THE BEST
CHANCE FOR MORE PERSISTENT...STRONGER WINDS WILL BE OVER THE W AND
NCENTRAL PORTIONS OF THE LAKE BETWEEN ISLE ROYALE AND THE
KEWEENAW...WHERE TERRAIN INFLUENCES WILL ENHANCE THE LOW LEVEL WINDS.
WINDS AFTER MON WILL DIMINISH TO UNDER 20 KTS AS A RELATIVELY WEAK
PRES GRADIENT TYPICAL OF MID SUMMER DOMINATES THE AREA. PATCHY FOG
THRU MON WILL BE LIMITED TO THE NE PORTIONS OF THE LAKE WHERE WATER
TEMPERATURES ARE LOWEST. &&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KF
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
152 PM EDT SUN JUL 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EDT SUN JUL 19 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STRONG SHRTWV
MOVING ENEWD THRU NW ONTARIO TO THE N OF UPR LVL RDG CENTERED OVER
THE SRN PLAINS. SFC COLD FNT ASSOCIATED WITH THE SHRTWV IS MOVING
THRU UPR MI EARLY THIS MRNG. DESPITE SOME FAIRLY HI MUCAPES FOR
EARLY IN THE MRNG...AS HI AS 1500-2000 J/KG...THERE HAVE BEEN ONLY
ISOLD SHRA/TS ALONG THE FNT/COMMA TAIL OF ONTARIO SHRTWV DUE TO
DRY/CAPPED MID LVLS DEPICTED ON THE 00Z GRB/RAOB AND RUC ANALYSIS
SDNGS AS WELL AS PASSAGE OF THIS FEATURE DURING PERIOD OF NOCTURNAL
COOLING. SOME GUSTY W WINDS HAVE DVLPD OVER WRN UPR MI IN THE WAKE
OF THE SFC COLD FROPA. THE 00Z INL RAOB SHOWED W WINDS AOA 30 KTS AS
LO AS 1K FT AGL WITH FAIRLY STEEP SFC-H7 LAPSE RATES BLO SHARP MID
LVL INVRN ASSOCIATED WITH DNVA/LARGER SCALE QVECTOR DVGC AND
SUBSIDENCE LEFT IN THE WAKE OF ONTARIO SHRTWV. LOOKING FARTHER
UPSTREAM...THERE IS ANOTHER SHRTWV DIGGING SEWD IN SASKATCHEWAN.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE ON GUSTY W WINDS TODAY.
TODAY...EXPECT ANY LINGERING SHRA/TS TO END BY ARND FCST ISSUANCE
WITH PASSAGE OF SFC COLD FNT TO THE E AND ARRIVAL OF DEEP LYR
QVECTOR DVGC/SUBSIDENCE. FOLLOWING THE FROPA...SHARP PRES GRADIENT
BTWN DEPARTING SHRTWV/SFC LO MOVING TOWARD HUDSON BAY AND SFC HI
PRES MOVING E THRU THE NCENTRL PLAINS IS FCST TO DOMINATE THE CWA.
WITH H925 WINDS AS HI AS 25-30 KTS AND DIURNAL HEATING WITH A GOOD
DEAL OF SUNSHINE CONTRIBUTING TO WELL MIXED LLVL LAPSE RATES/SOME
DIURNAL CU...EXPECT SOME GUSTY WINDS. THE STRONGEST WINDS ARE MOST
LIKELY OVER THE EXPOSED KEWEENAW PENINSULA...WHERE LK BREEZE
CONTRIBUTION WL AID THE GUSTY WINDS TO 30-35 MPH. WITH H85 TEMPS
NEAR 14-15C THIS AFTN AND DEEP MIXING...EXPECT HI TEMPS TO RISE INTO
THE 80S TOWARD THE HI END OF GUIDANCE AWAY FM LK MODERATION.
TNGT...LINGERING GUSTY WINDS WL DIMINISH IN THE EVNG WITH LOSS OF
DAYTIME HEATING. THEN SHRTWV NOW MOVING INTO SASKATCHEWAN IS FCST TO
SLIDE SEWD THRU NW ONTARIO. SINCE BULK OF THE DPVA/DEEP LYR
FORCING/MID LVL MOISTENING IS PROGGED TO REMAIN TO THE N AND MSTR
INFLOW WL BE LIMITED BY PREVAILING W WIND DURING PERIOD OF NOCTURNAL
COOLING...ALMOST ALL OF THE SHORT TERM MODELS INDICATE THE PCPN WL
REMAIN TO THE N OF THE LAND CWA. THE NAM DOES SHOW SOME SHOWERS
BRUSHING THE KEWEENAW PENINSULA. WITH STEADY WSW SFC WINDS...THE
DIURNAL FALL OF TEMP WL BE GREATLY REDUCED. THE WARMER DOWNSLOPE
LOCATIONS NEAR LK SUP WL SEE MIN TEMPS HOLD ARND 65.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 233 AM EDT SUN JUL 19 2015
IMPACTS...QUIET LONG TERM WITH NO SIGNIFICANT IMPACTS EXPECTED.
PRECIP...COULD SEE SOME ISOLATED SHOWERS AND THUNDERSTORMS MON AS A
DISTURBANCE MOVING N OF THE CWA DRAGS A COLD FRONT ACROSS THE AREA.
WILL KEEP SOME SLIGHT CHANCE POPS MAINLY MON AFTERNOON.
OTHERWISE...COULD SEE SOME PRECIP FRI INTO SAT AS A LOW PRESSURE
SYSTEM MOVES ACROSS ONTARIO. MODELS DO SHOW A BLIP OR TWO OF QPF TUE
AND WED...WHICH MAY OCCUR IF A SHORTWAVE MOVES THROUGH THE NW
FLOW...BUT CERTAINLY NOT CONFIDENT ENOUGH TO INCLUDE THAT IN THE
FORECAST.
TEMPS...WARMEST TEMPS ON MON WITH HIGHS FROM THE MID 70S ALONG LAKE
SUPERIOR TO THE 80S INLAND...INCLUDING UPPER 80S SCENTRAL. TUE AND
WED WE WILL BE BETWEEN AN UPPER TROUGH E AND A BUILDING RIDGE W...SO
THE NW FLOW WILL KEEP TEMPS MORE SEASONAL. TUE AND WED HIGHS WILL BE
IN THE 70S (60S E ALONG THE LAKE SUPERIOR SHORE) WITH LOWS IN THE
50S. THE RIDGE LOOKS TO MOVE THROUGH THU AND FRI...ALLOWING FOR
HIGHS IN THE 70S AND 80S THU THROUGH SAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 151 PM EDT SUN JUL 19 2015
VFR CEILINGS AND VIS WILL PREVAIL THROUGH THE PERIOD. THE MAIN
THREAT WILL BE WINDS GUSTING 20-35KTS DURING THE DAYTIME HOURS...AND
LLWS AT NIGHT AS DAYTIME MIXING DIMINISHES. THIS IS ALL THANKS TO
UPPER MI BEING BETWEEN LOW PRESSURE OVER MANITOBA AND HUDSON
BAY...AND HIGH PRESSURE MOVING FROM THE CENTRAL PLAINS TO THE OHIO
VALLEY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EDT SUN JUL 19 2015TIGHT PRES GRADIENT BETWEEN LO PRES MOVING INTO HUDSON BAY
AND HI PRES MOVING THRU THE NCENTRAL PLAINS WILL CAUSE SOME WSW
WINDS AS HI AS 25 KTS THRU MON. THE BEST CHANCE FOR MORE
PERSISTENT...STRONGER WINDS WILL BE OVER THE W AND NCENTRAL PORTIONS
OF THE LAKE BETWEEN ISLE ROYALE AND THE KEWEENAW...WHERE TERRAIN
INFLUENCES WILL ENHANCE THE LOW LEVEL WINDS. WINDS AFTER MON WILL
DIMINISH TO UNDER 20 KTS AS A RELATIVELY WEAK PRES GRADIENT TYPICAL
OF MID SUMMER DOMINATES THE AREA. PATCHY FOG THRU MON WILL BE
LIMITED TO THE NE PORTIONS OF THE LAKE WHERE WATER TEMPERATURES ARE
LOWEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...KF
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
356 AM EDT SUN JUL 19 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EDT SUN JUL 19 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW STRONG SHRTWV
MOVING ENEWD THRU NW ONTARIO TO THE N OF UPR LVL RDG CENTERED OVER
THE SRN PLAINS. SFC COLD FNT ASSOCIATED WITH THE SHRTWV IS MOVING
THRU UPR MI EARLY THIS MRNG. DESPITE SOME FAIRLY HI MUCAPES FOR
EARLY IN THE MRNG...AS HI AS 1500-2000 J/KG...THERE HAVE BEEN ONLY
ISOLD SHRA/TS ALONG THE FNT/COMMA TAIL OF ONTARIO SHRTWV DUE TO
DRY/CAPPED MID LVLS DEPICTED ON THE 00Z GRB/RAOB AND RUC ANALYSIS
SDNGS AS WELL AS PASSAGE OF THIS FEATURE DURING PERIOD OF NOCTURNAL
COOLING. SOME GUSTY W WINDS HAVE DVLPD OVER WRN UPR MI IN THE WAKE
OF THE SFC COLD FROPA. THE 00Z INL RAOB SHOWED W WINDS AOA 30 KTS AS
LO AS 1K FT AGL WITH FAIRLY STEEP SFC-H7 LAPSE RATES BLO SHARP MID
LVL INVRN ASSOCIATED WITH DNVA/LARGER SCALE QVECTOR DVGC AND
SUBSIDENCE LEFT IN THE WAKE OF ONTARIO SHRTWV. LOOKING FARTHER
UPSTREAM...THERE IS ANOTHER SHRTWV DIGGING SEWD IN SASKATCHEWAN.
MAIN FCST CONCERNS IN THE SHORT TERM WL BE ON GUSTY W WINDS TODAY.
TODAY...EXPECT ANY LINGERING SHRA/TS TO END BY ARND FCST ISSUANCE
WITH PASSAGE OF SFC COLD FNT TO THE E AND ARRIVAL OF DEEP LYR
QVECTOR DVGC/SUBSIDENCE. FOLLOWING THE FROPA...SHARP PRES GRADIENT
BTWN DEPARTING SHRTWV/SFC LO MOVING TOWARD HUDSON BAY AND SFC HI
PRES MOVING E THRU THE NCENTRL PLAINS IS FCST TO DOMINATE THE CWA.
WITH H925 WINDS AS HI AS 25-30 KTS AND DIURNAL HEATING WITH A GOOD
DEAL OF SUNSHINE CONTRIBUTING TO WELL MIXED LLVL LAPSE RATES/SOME
DIURNAL CU...EXPECT SOME GUSTY WINDS. THE STRONGEST WINDS ARE MOST
LIKELY OVER THE EXPOSED KEWEENAW PENINSULA...WHERE LK BREEZE
CONTRIBUTION WL AID THE GUSTY WINDS TO 30-35 MPH. WITH H85 TEMPS
NEAR 14-15C THIS AFTN AND DEEP MIXING...EXPECT HI TEMPS TO RISE INTO
THE 80S TOWARD THE HI END OF GUIDANCE AWAY FM LK MODERATION.
TNGT...LINGERING GUSTY WINDS WL DIMINISH IN THE EVNG WITH LOSS OF
DAYTIME HEATING. THEN SHRTWV NOW MOVING INTO SASKATCHEWAN IS FCST TO
SLIDE SEWD THRU NW ONTARIO. SINCE BULK OF THE DPVA/DEEP LYR
FORCING/MID LVL MOISTENING IS PROGGED TO REMAIN TO THE N AND MSTR
INFLOW WL BE LIMITED BY PREVAILING W WIND DURING PERIOD OF NOCTURNAL
COOLING...ALMOST ALL OF THE SHORT TERM MODELS INDICATE THE PCPN WL
REMAIN TO THE N OF THE LAND CWA. THE NAM DOES SHOW SOME SHOWERS
BRUSHING THE KEWEENAW PENINSULA. WITH STEADY WSW SFC WINDS...THE
DIURNAL FALL OF TEMP WL BE GREATLY REDUCED. THE WARMER DOWNSLOPE
LOCATIONS NEAR LK SUP WL SEE MIN TEMPS HOLD ARND 65.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 233 AM EDT SUN JUL 19 2015
IMPACTS...QUIET LONG TERM WITH NO SIGNIFICANT IMPACTS EXPECTED.
PRECIP...COULD SEE SOME ISOLATED SHOWERS AND THUNDERSTORMS MON AS A
DISTURBANCE MOVING N OF THE CWA DRAGS A COLD FRONT ACROSS THE AREA.
WILL KEEP SOME SLIGHT CHANCE POPS MAINLY MON AFTERNOON.
OTHERWISE...COULD SEE SOME PRECIP FRI INTO SAT AS A LOW PRESSURE
SYSTEM MOVES ACROSS ONTARIO. MODELS DO SHOW A BLIP OR TWO OF QPF TUE
AND WED...WHICH MAY OCCUR IF A SHORTWAVE MOVES THROUGH THE NW
FLOW...BUT CERTAINLY NOT CONFIDENT ENOUGH TO INCLUDE THAT IN THE
FORECAST.
TEMPS...WARMEST TEMPS ON MON WITH HIGHS FROM THE MID 70S ALONG LAKE
SUPERIOR TO THE 80S INLAND...INCLUDING UPPER 80S SCENTRAL. TUE AND
WED WE WILL BE BETWEEN AN UPPER TROUGH E AND A BUILDING RIDGE W...SO
THE NW FLOW WILL KEEP TEMPS MORE SEASONAL. TUE AND WED HIGHS WILL BE
IN THE 70S (60S E ALONG THE LAKE SUPERIOR SHORE) WITH LOWS IN THE
50S. THE RIDGE LOOKS TO MOVE THROUGH THU AND FRI...ALLOWING FOR
HIGHS IN THE 70S AND 80S THU THROUGH SAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 121 AM EDT SUN JUL 19 2015
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD. COLD FRONT
HAS ALREADY MOVED THROUGH THE TAF SITES SO NOT EXPECTING ANY
CONVECTION OVERNIGHT. EXPECT GUSTY WESTERLY WINDS AT ALL TAF SITES
OVERNIGHT INTO SUNDAY WITH THE HIGHEST WIND GUSTS (TO 30 KTS)
EXPECTED AT KCMX DURING THE DAY ON SUNDAY. LLWS IS ALSO POSSIBLE AT
KIWD SUNDAY EVENING AS STRONGER WEST WINDS CONTINUE OFF THE SFC AS
WINDS DECOUPLE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 AM EDT SUN JUL 19 2015TIGHT PRES GRADIENT BETWEEN LO PRES MOVING INTO HUDSON BAY
AND HI PRES MOVING THRU THE NCENTRAL PLAINS WILL CAUSE SOME WSW
WINDS AS HI AS 25 KTS THRU MON. THE BEST CHANCE FOR MORE
PERSISTENT...STRONGER WINDS WILL BE OVER THE W AND NCENTRAL PORTIONS
OF THE LAKE BETWEEN ISLE ROYALE AND THE KEWEENAW...WHERE TERRAIN
INFLUENCES WILL ENHANCE THE LOW LEVEL WINDS. WINDS AFTER MON WILL
DIMINISH TO UNDER 20 KTS AS A RELATIVELY WEAK PRES GRADIENT TYPICAL
OF MID SUMMER DOMINATES THE AREA. PATCHY FOG THRU MON WILL BE
LIMITED TO THE NE PORTIONS OF THE LAKE WHERE WATER TEMPERATURES ARE
LOWEST.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
233 AM EDT SUN JUL 19 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 326 PM EDT SAT JUL 18 2015
NAM SHOWS A 500 MB TROUGH IN THE NORTHERN PLAINS THIS MORNING THAT
MOVES EAST TODAY AND THROUGH THE AREA TONIGHT.
COMPLICATED FORECAST CONTINUES AS NAM...HRR AND RUC ALL POINT TO NO
REDEVELOPMENT OF CONVECTION THIS AFTERNOON AND EVENING. PROBLEM IS
NONE OF THOSE MODELS ALSO HANDLED THE MCV/QLCS THAT WENT THROUGH
SOUTH OF HERE THIS MORNING EITHER. CANADIAN POINTS TO REDEVELOPMENT
THIS AFTERNOON ALONG WITH GFS AND ECMWF. TO COMPLICATE THINGS
FURTHER...THE 12Z MPX SOUNDING IS FAIRLY DRY AND CAPPED WHILE THE
12Z INL SOUNDING IS UNSTABLE AND MOIST. CONFIDENCE IS LOW THOUGH
WITH THIS FORECAST AND APPEARS THAT THE DRIER AND CAPPED MODEL
SOLUTION SEEMS TO BE VERIFYING AND WILL GO WITH THAT SCENARIO. ONLY
PROBLEM IS THAT IF SOMETHING WOULD GO...IT WOULD GO SEVERE IN A
HURRY AS STRONGER SHEAR AND STRONGER WINDS ARE FORECASTED TO COME IN
LATE THIS AFTERNOON...BUT WITH CAPPED ATMOSPHERE OVER THE
AREA...THINKING IS CUTTING POPS TO SLIGHT CHANCE IS THE WAY TO GO
WITH COLD FRONT COMING THROUGH THIS EVENING AND WILL GO SLIGHT
CHANCE IN CASE SOMETHING IS ABLE TO BREAK THAT CAP. STILL THINK
SMALL HAIL AND WIND GUSTS ARE POSSIBLE
OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES. CUT BACK ON THE POPS THIS AFTERNOON AND TONIGHT AND
WENT SLIGHT CHANCE ONLY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 233 AM EDT SUN JUL 19 2015
IMPACTS...QUIET LONG TERM WITH NO SIGNIFICANT IMPACTS EXPECTED.
PRECIP...COULD SEE SOME ISOLATED SHOWERS AND THUNDERSTORMS MON AS A
DISTURBANCE MOVING N OF THE CWA DRAGS A COLD FRONT ACROSS THE AREA.
WILL KEEP SOME SLIGHT CHANCE POPS MAINLY MON AFTERNOON.
OTHERWISE...COULD SEE SOME PRECIP FRI INTO SAT AS A LOW PRESSURE
SYSTEM MOVES ACROSS ONTARIO. MODELS DO SHOW A BLIP OR TWO OF QPF TUE
AND WED...WHICH MAY OCCUR IF A SHORTWAVE MOVES THROUGH THE NW
FLOW...BUT CERTAINLY NOT CONFIDENT ENOUGH TO INCLUDE THAT IN THE
FORECAST.
TEMPS...WARMEST TEMPS ON MON WITH HIGHS FROM THE MID 70S ALONG LAKE
SUPERIOR TO THE 80S INLAND...INCLUDING UPPER 80S SCENTRAL. TUE AND
WED WE WILL BE BETWEEN AN UPPER TROUGH E AND A BUILDING RIDGE W...SO
THE NW FLOW WILL KEEP TEMPS MORE SEASONAL. TUE AND WED HIGHS WILL BE
IN THE 70S (60S E ALONG THE LAKE SUPERIOR SHORE) WITH LOWS IN THE
50S. THE RIDGE LOOKS TO MOVE THROUGH THU AND FRI...ALLOWING FOR
HIGHS IN THE 70S AND 80S THU THROUGH SAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 121 AM EDT SUN JUL 19 2015
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD. COLD FRONT
HAS ALREADY MOVED THROUGH THE TAF SITES SO NOT EXPECTING ANY
CONVECTION OVERNIGHT. EXPECT GUSTY WESTERLY WINDS AT ALL TAF SITES
OVERNIGHT INTO SUNDAY WITH THE HIGHEST WIND GUSTS (TO 30 KTS)
EXPECTED AT KCMX DURING THE DAY ON SUNDAY. LLWS IS ALSO POSSIBLE AT
KIWD SUNDAY EVENING AS STRONGER WEST WINDS CONTINUE OFF THE SFC AS
WINDS DECOUPLE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 326 PM EDT SAT JUL 18 2015
ALTHOUGH WINDS WILL BE UNDER 20 KTS INTO TNGT... STRONGER WINDS WILL
BE POSSIBLE IN THUNDERSTORMS TODAY INTO TONIGHT AHEAD OF AN
APPROACHING COLD FRONT AS WATER TEMPS ARE WARMING UP...WHICH WILL
LIMIT LOW-LEVEL STABILITY AND INCREASE THE CHANCE STRONGER WINDS
WILL BE TRANSPORTED TO THE SURFACE. THEN TIGHTENING PRES GRADIENT
BEHIND THE COLD FRONT CROSSING THE LAKE TONIGHT AND BETWEEN HI PRES
MOVING THRU THE NCENTRAL PLAINS AND LO PRES OVER HUDSON BAY WILL
BRING SOME WSW WINDS AS HI AS 25 KTS FROM LATE TONIGHT AND SUN. THE
BEST CHANCE FOR MORE PERSISTENT...STRONGER WINDS WILL BE OVER THE W
AND NCENTRAL PORTIONS BETWEEN ISLE ROYALE AND THE KEWEENAW WHERE
TERRAIN WILL ENHANCE THE LOW LEVEL WINDS. WINDS AFTER SUN NIGHT WILL
DIMINISH TO UNDER 20 KTS AS A RELATIVELY WEAK PRES GRADIENT
DOMINATES NEXT WEEK. RATHER HUMID AIR WILL CAUSE SOME FOG OVER
MAINLY THE COOLER WATERS OF NORTHERN LAKE SUPERIOR THROUGH MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...TITUS
AVIATION...VOSS
MARINE...07
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
122 AM EDT SUN JUL 19 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 326 PM EDT SAT JUL 18 2015
NAM SHOWS A 500 MB TROUGH IN THE NORTHERN PLAINS THIS MORNING THAT
MOVES EAST TODAY AND THROUGH THE AREA TONIGHT.
COMPLICATED FORECAST CONTINUES AS NAM...HRR AND RUC ALL POINT TO NO
REDEVELOPMENT OF CONVECTION THIS AFTERNOON AND EVENING. PROBLEM IS
NONE OF THOSE MODELS ALSO HANDLED THE MCV/QLCS THAT WENT THROUGH
SOUTH OF HERE THIS MORNING EITHER. CANADIAN POINTS TO REDEVELOPMENT
THIS AFTERNOON ALONG WITH GFS AND ECMWF. TO COMPLICATE THINGS
FURTHER...THE 12Z MPX SOUNDING IS FAIRLY DRY AND CAPPED WHILE THE
12Z INL SOUNDING IS UNSTABLE AND MOIST. CONFIDENCE IS LOW THOUGH
WITH THIS FORECAST AND APPEARS THAT THE DRIER AND CAPPED MODEL
SOLUTION SEEMS TO BE VERIFYING AND WILL GO WITH THAT SCENARIO. ONLY
PROBLEM IS THAT IF SOMETHING WOULD GO...IT WOULD GO SEVERE IN A
HURRY AS STRONGER SHEAR AND STRONGER WINDS ARE FORECASTED TO COME IN
LATE THIS AFTERNOON...BUT WITH CAPPED ATMOSPHERE OVER THE
AREA...THINKING IS CUTTING POPS TO SLIGHT CHANCE IS THE WAY TO GO
WITH COLD FRONT COMING THROUGH THIS EVENING AND WILL GO SLIGHT
CHANCE IN CASE SOMETHING IS ABLE TO BREAK THAT CAP. STILL THINK
SMALL HAIL AND WIND GUSTS ARE POSSIBLE
OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES. CUT BACK ON THE POPS THIS AFTERNOON AND TONIGHT AND
WENT SLIGHT CHANCE ONLY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 353 PM EDT SAT JUL 18 2015
SUNDAY NIGHT THROUGH MONDAY NIGHT...AN UPPER LEVEL 500MB CLOSED LOW
AND ASSOCIATED SURFACE LOW WILL REMAIN NEARLY STATIONARY OVER HUDSON
BAY THROUGH THIS TIME PERIOD. THE MAIN IMPACTS FROM THIS WILL COME
FROM A SHORTWAVE AND SURFACE TROUGH/COLD FRONT...STRETCHING
SOUTHWEST INTO NORTHWEST MN SUNDAY NIGHT. THESE FEATURES WILL SLIDE
TO THE EAST...CROSSING THE U.P. BETWEEN 18Z/20 AND 00Z/21. THE VORT
MAX IS PROGGED TO REMAIN OVER LAKE SUPERIOR AND FARTHER NORTH OF
THE U.P. THIS CAN ALSO BE SEEN BY OVERLAYING DEEP LAYER 850MB-300MB
QCONV WITH DEEP LAYER RH. THERE WILL NOT BE A LOT OF MOISTURE TO
WORK WITH LIMITING THE POPS TO SLIGHT CHANCE DURING THIS TIME
PERIOD...AGAIN...THE BEST CHANCES WILL BE MONDAY AFTERNOON INTO THE
EARLY EVENING HOURS...DURING FRONTAL PASSAGE. HIGH TEMPERATURES
MONDAY AFTERNOON WILL WARM INTO THE MID 80S AHEAD OF THE COLD FRONT
AS 850MB TEMPS WARM TO AROUND 18C TO 19C...BEFORE COOLING FROM WEST
TO EAST LATE IN THE AFTERNOON INTO THE EVENING.
TUESDAY THROUGH WEDNESDAY NIGHT...AN ADDITIONAL...VERY WEAK WAVE
WILL SLIDE TO THE NORTH OF THE U.P. LATE MONDAY NIGHT INTO EARLY
TUESDAY MORNING...BUT LITTLE TO NO PRECIP IS EXPECTED FROM THIS
SYSTEM WITH CONTINUED LIMITED MOISTURE AROUND ALONG WITH VERY WEAK
FORCING. ADDITIONALLY...A SURFACE RIDGE WILL BEGIN BUILDING INTO THE
REGION BRINGING ANTICYCLONIC FLOW ALONG WITH EVEN DRYER AIR. THIS
HIGH PRESSURE CENTER WILL CONTINUE TO SLIDE ACROSS THE UPPER GREAT
LAKES REGION TUESDAY AFTERNOON THROUGH WEDNESDAY NIGHT ALLOWING FOR
MAINLY DRY CONDITIONS UNDER A MOSTLY CLEAR TO PARTLY CLOUDY SKY.
850MB TEMPS WILL FALL TO AROUND 12C TO 13C TUESDAY AFTERNOON AND
WEDNESDAY AFTERNOON ALLOWING TEMPERATURES TO COOL BACK TO THE MID
70S...WHICH IS CLOSE TO NORMAL FOR THIS TIME OF YEAR.
THURSDAY THROUGH SATURDAY...MODELS SHOW AN UPPER LEVEL 500MB RIDGE
AXIS SLIDING ACROSS THE UPPER GREAT LAKES REGION THURSDAY INTO
THURSDAY NIGHT IN ADVANCE OF A DEVELOPING LOW PRESSURE SYSTEM AND
ASSOCIATED COLD FRONT...ALLOWING TEMPERATURES TO WARM ONCE AGAIN.
THE COLD FRONT IS EXPECTED TO SLIDE ACROSS THE AREA FRIDAY AFTERNOON
THROUGH SATURDAY BRINGING THE NEXT...WIDESPREAD...CHANCE FOR SHOWERS
AND THUNDERSTORMS. AT THIS POINT DECIDED TO STICK WITH A CONSENSUS
OF THE MODELS DURING THIS TIME PERIOD...WHICH SEEMED REASONABLE WITH
TIMING OF THE FRONT. AS IS USUALLY THE CASE...BEING THIS FAR THERE
WILL LIKELY NEED TO BE ADJUSTMENTS TO TIMING AND INTENSITY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 121 AM EDT SUN JUL 19 2015
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD. COLD FRONT
HAS ALREADY MOVED THROUGH THE TAF SITES SO NOT EXPECTING ANY
CONVECTION OVERNIGHT. EXPECT GUSTY WESTERLY WINDS AT ALL TAF SITES
OVERNIGHT INTO SUNDAY WITH THE HIGHEST WIND GUSTS (TO 30 KTS)
EXPECTED AT KCMX DURING THE DAY ON SUNDAY. LLWS IS ALSO POSSIBLE AT
KIWD SUNDAY EVENING AS STRONGER WEST WINDS CONTINUE OFF THE SFC AS
WINDS DECOUPLE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 326 PM EDT SAT JUL 18 2015
ALTHOUGH WINDS WILL BE UNDER 20 KTS INTO TNGT... STRONGER WINDS WILL
BE POSSIBLE IN THUNDERSTORMS TODAY INTO TONIGHT AHEAD OF AN
APPROACHING COLD FRONT AS WATER TEMPS ARE WARMING UP...WHICH WILL
LIMIT LOW-LEVEL STABILITY AND INCREASE THE CHANCE STRONGER WINDS
WILL BE TRANSPORTED TO THE SURFACE. THEN TIGHTENING PRES GRADIENT
BEHIND THE COLD FRONT CROSSING THE LAKE TONIGHT AND BETWEEN HI PRES
MOVING THRU THE NCENTRAL PLAINS AND LO PRES OVER HUDSON BAY WILL
BRING SOME WSW WINDS AS HI AS 25 KTS FROM LATE TONIGHT AND SUN. THE
BEST CHANCE FOR MORE PERSISTENT...STRONGER WINDS WILL BE OVER THE W
AND NCENTRAL PORTIONS BETWEEN ISLE ROYALE AND THE KEWEENAW WHERE
TERRAIN WILL ENHANCE THE LOW LEVEL WINDS. WINDS AFTER SUN NIGHT WILL
DIMINISH TO UNDER 20 KTS AS A RELATIVELY WEAK PRES GRADIENT
DOMINATES NEXT WEEK. RATHER HUMID AIR WILL CAUSE SOME FOG OVER
MAINLY THE COOLER WATERS OF NORTHERN LAKE SUPERIOR THROUGH MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...KEC
AVIATION...VOSS
MARINE...07
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1228 AM CDT SUN JUL 19 2015
.UPDATE...
ISSUED AT 645 PM CDT SAT JUL 18 2015
COLD FRONT IS MOVING SLOWLY THROUGH THE ARROWHEAD AND NW WI.
A CU FIELD COVERS THE AREA...BUT ISOLD SHOWERS HAVE BEEN
DIMINISHING AS BEST FORCING IS NOW IN CANADA NEAR THE UPPER LOW
THAT HAS REACHED NW ONTARIO. HAVE REMOVED RAIN MENTION FOR
TONIGHT. MADE SOME OTHER MINOR ADJUSTMENTS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 341 PM CDT SAT JUL 18 2015
CONCERN FOR THE SHORT TERM IS PRECIP CHANCES THIS EVENING.
CURRENT SURFACE ANALYSIS INDICATES THUNDERSTORMS JUST NORTH OF THE
ARROWHEAD IN SOUTHERN CANADA. HRRR INDICATES THERE COULD BE SOME
SPOTTY PRECIP ACROSS THE BORDERLAND THIS EVENING BEHIND THE FRONT
AND A WEAK SHORTWAVE MOVE THROUGH THE REGION. FOR THE REST OF THE
FORECAST AREA THIS AFTERNOON...SKIES WILL STAY PARTLY CLOUDY AS
THE FRONT (IN NW WI AT 20Z) WILL CONTINUE TO MOVE THROUGH THE AREA.
IF ANY PRECIP DEVELOPS...IT WILL BE WIDELY SCATTERED. THE 12Z MPX
SOUNDING WAS CAPPED AND THERE IS NOT MUCH VERTICAL DEVELOPMENT TO
THE CLOUDS AS INDICATED BY OBSERVATION AND SATELLITE. ALL OF THE FORECAST
AREA WILL SEE CLEAR TO PARTLY CLOUDY SKIES LATER THIS EVENING
THROUGH THE OVERNIGHT. WEAK HIGH PRESSURE WILL BUILD INTO THE
REGION LATE TONIGHT AND WILL CAUSE PARTLY TO MOSTLY SUNNY SKIES ON
SUNDAY WITH LESS HUMID CONDITIONS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 341 PM CDT SAT JUL 18 2015
SUNDAY NIGHT...A COLD FRONT WILL MOVE INTO NORTHERN MINNESOTA
SUNDAY EVENING...THEN FINISH MOVING THROUGH THE REST OF THE
NORTHLAND OVERNIGHT INTO MONDAY MORNING. THE
GEM/GFS/ECMWF/NAM/SREF/WRF ARE INDICATING THE POTENTIAL FOR PCPN
OVER THE NORTHERN FORECAST AREA WITH THE PASSAGE OF THE COLD
FRONT. THE GEM IS THE MOST AGGRESSIVE WITH PCPN. THERE COULD BE
ENOUGH INSTABILITY FROM THE DAYTIME HEATING LEFT OVER IN THE
EVENING FOR THE COLD FRONT TO SET OFF SOME SHOWERS. THE THREAT OF
THUNDER LOOKS TO BE VERY LOW. THE NAM12/SREF/GFS INDICATE NEARLY
NO CAPE. IT APPEARS WARM UPPER LEVEL TEMPERATURES WILL LIMIT
MUCAPE FROM GETTING MUCH MORE THAN 100 OR 200 J/KG. LEFT THUNDER
OUT OF THE FORECAST SINCE THE THREAT OF THUNDER SEEMS SO LOW.
MONDAY...SLIGHTLY COOLER AND LESS HUMID WEATHER IS EXPECTED IN THE
NW FLOW PATTERN. THE CONVECTIVE TEMPERATURES SHOULD BE LOW ENOUGH TO
POP SCATTERED/BROKEN CUMULUS BY THE EARLY AFTERNOON FOR MOST AREAS.
HIGH TEMPERATURES SHOULD RANGE FROM THE LOWER 70S OVER THE NORTH TO
NEAR 80 IN NW WISCONSIN. BUMPED UP THE TEMPERATURE FOR PARK POINT
BEACH TO 83 TO ACCOUNT FOR DOWNSLOPE WARMING.
TUESDAY...HIGH PRESSURE WILL MOVE INTO THE UPPER MIDWEST...PROVIDING
THE NORTHLAND WITH A SUNNY AND COMFORTABLE DAY. HIGHS SHOULD BE IN
THE MIDDLE 70S.
WEDNESDAY THROUGH FRIDAY...THE GFS/ECMWF/GEM GENERALLY INDICATE AN
UPPER LEVEL RIDGE WILL SHIFT FROM THE WESTERN PLAINS INTO UPPER
MIDWEST DURING THIS TIMEFRAME. THIS WILL BRING A WARMING TREND
THROUGH FRIDAY...WITH HIGHS BUILDING BACK INTO THE 80S FOR THE LATE
WEEK. THE WARM LOW LEVEL SOUTHERLY FLOW PATTERN WILL CAUSE AFTERNOON
AND EARLY EVENING INSTABILITY FROM DAYTIME HEATING...BUT THERE IS
GENERALLY VERY LOW CHANCES OF SHOWERS AND THUNDERSTORMS IN THE
ABSENCE OF ANY SIGNIFICANT FORCING MECHANISM. THERE ARE SOME SIGNS A
SHORTWAVE TROUGH COULD LIFT THROUGH THE NORTHERN PLAINS OR WESTERN
LAKE SUPERIOR REGION SOMETIME WEDNESDAY NIGHT THROUGH FRIDAY...WHICH
WOULD GIVE A BETTER OPPORTUNITY FOR SHOWER AND STORM
DEVELOPMENT...BUT THE MODELS ARE LACKING AGREEMENT ON ITS TIMING.
THE GFS HAS THE SHORTWAVE TROUGH MOVING THROUGH THURSDAY...THE ECMWF
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1228 AM CDT SUN JUL 19 2015
VFR THROUGH THE FORECAST. GUSTY SFC WINDS ARE EXPECTED BY 15Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 62 79 55 76 / 0 10 10 0
INL 59 72 51 74 / 40 20 10 0
BRD 64 80 56 79 / 0 10 10 0
HYR 63 80 54 76 / 0 10 10 10
ASX 64 79 56 76 / 0 10 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GSF
SHORT TERM...STEWART
LONG TERM...GROCHOCINSKI
AVIATION...GSF
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
122 AM CDT SUN JUL 19 2015
.UPDATE:
ISSUED AT 957 PM CDT SAT JUL 18 2015
LATEST RUNS OF THE RAP AND HRRR ARE STILL SHOWING THE POTENTIAL
FOR ELEVATED THUNDERSTORMS TO REDEVELOP OVER NORTHERN MO INTO
WEST CENTRAL IL LATER THIS EVENING AS 925-850 MOISTURE CONVERGENCE
BEGINS TO INCREASES ON NOSE OF LOW LEVEL JET. WILL KEEP CHANCE OF
THUNDERSTORMS GOING FROM LATE EVENING ONWARD INTO THE OVERNIGHT
HOURS AS THIS FORCING INCREASES THROUGH 06Z AND THEN SHIFTS TOWARD
I-70 OVERNIGHT. OTHERWISE IT IS ANOTHER WARM AND MUGGY NIGHT WITH
TEMPERATURES IN THE 80S WITH DEWPOINTS IN THE MID 70S.
BRITT
&&
.SHORT TERM: (THROUGH LATE TONIGHT)
ISSUED AT 333 PM CDT SAT JUL 18 2015
A SHORT WAVE IS FCST TO PASS NORTH OF THE AREA TONIGHT CAN BE SEEN
SPINNING ACROSS STHRN MANITOBA THIS AFTN. THIS FEATURE WILL ACT TO
FLATTEN THE RIDGE AND PUT THE FA ON THE STHRN FRINGE OF ZONAL FLOW.
THE TSTM COMPLEX FROM THIS MORNING LAID OUT AN OUTFLOW BNDRY THAT AS
OF 20Z STRETCHES FROM NTHRN PHELPS...CRAWFORD...WASHINGTON AND STHRN
JEFFERSON COUNTIES IN MO AND BECOMES UNIDENTIFIABLE FARTHER EAST
INTO SW IL. ISLD CONVECTION IS POSSIBLE ALONG THIS BNDRY THIS AFTN
BUT MID LVL TEMPS IN THE LOWER TEENS SHOULD LIMIT COVERAGE. THIS
BNDRY SHOULD CONTINUE TO DSSPT THIS EVNG. A WEAK COLD FRONT ASSOC
WITH THE AFOREMENTIONED SHORT WAVE IS FCST TO DROP INTO THE NTHRN FA
OVERNIGHT. AS A RESULT OF MORE THAN ENOUGH SB CAPE...IN EXCESS OF
5000 J/KG THIS EVNG...AND 0-6KM BULK SHEAR OF 20-25 KTS...THE NTHRN
PORTION OF THE CWA IS IN A SLIGHT RISK FOR LATE THIS AFTN INTO THIS
EVNG. MID LVL TEMPS REMAIN A CONCERN BUT AMS IS UNCAPPED AND QUITE
UNSTABLE SO THINK AMOUNT OF AVAILABLE ENERGY AND CONVERGENCE AHEAD
OF THE APPROACHING COLD FRONT WILL BE SUFFICIENT TO OVERCOME THE
RELATIVELY WARM MID LVLS. GUIDANCE INDICATES THE CONVECTION SHOULD
DSSPT TOWARDS 12Z WITH THE BEST GUESS ATTM BEING SOMEWHERE ALONG
I70...BUT THE REAL QUESTION IS WHERE THE RESULTANT OUTFLOW BNDRY
ENDS UP BY SUN AFTN. USED A BLEND OF GUIDANCE FOR OVERNIGHT LOWS AS
MOS SEEMS REASONABLE.
2%
.LONG TERM: (SUNDAY THROUGH NEXT SATURDAY)
ISSUED AT 333 PM CDT SAT JUL 18 2015
THE NEXT IN A SERIES OF SHORT WAVES PASSES NORTH OF THE CWA SUN
NIGHT INTO MON MRNG WHICH TRANSITIONS THE UPPER LVL FLOW INTO LOW
AMPLITUDE NW FLOW WITH SLOW HEIGHT FALLS CONTINUING INTO EARLY
NEXT WEEK. ANOTHER ROUND OF SHRAS/TSTMS IS EXPECTED TO DVLP IN THE
VC OF THE OUTFLOW BNDRY AND DSSPTNG COLD FRONT SUN AFTN. THE COLD
FRONT IS FCST TO DISSOLVE SUN EVNG IN THE VC OF I70 WITH STHRLY
SFC FLOW RETURNING BY MON MRNG. ALMOST THE ENTIRE CWA IS UNDER A
MARGINAL RISK PER SPC ON SUN/SUN NIGHT DUE TO PLENTY OF CAPE AND
MARGINAL 0-6KM BULK SHEAR. THE THREAT OF CLOUDS AND PRECIP ACROSS
THE AREA ON SUN PUTS THE HEAT ADVY IN QUESTION...ESP FOR AREAS
NORTH OF I70 WHERE THE OUTFLOW BNDRY IS EXPECTED TO BE...BUT NOT
SURE I CAN CUT THE CHEESE THAT FINE SO WILL LEAVE THE HEADLINE AS
IS. MY LUCK I WOULD ZIG AND MOTHER NATURE WOULD ZAG.
THE NEXT SHORT WAVE PASSES BY MON AFTN/EVNG WITH THE ASSOC COLD
FRONT ENTERING THE NTHRN CWA MON NIGHT PASSING SOUTH OF THE FA BY
TUE EVNG. MOST OF THE AREA IS IN A SLIGHT RISK ON MON/MON NIGHT. I
DO NOT HAVE A GOOD FEEL FOR CONVECTIVE TRENDS SUN THRU MON NIGHT AND
AS SUCH THE POP FCST IS A LOW CONFIDENCE FCST. I AM SURE THERE WILL
BE PERIODIC SCTTRD CONVECTION OVER THE NEXT SEVERAL DAYS BUT I AM
NOT SURE ABOUT PLACEMENT...TIMING OR COVERAGE.
WENT AOB THE COOLER MOS GUIDANCE SUN/MON NORTH OF I70 IN
ANTICIPATION OF PLENTY OF CLOUDS AND POTENTIAL PRECIP. USED MORE OF
A BLEND ALONG AND SOUTH OF I70...FOR LOCATIONS THAT SHOULD BE SOUTH
OF THE COLD FRONT/OUTFLOW BNDRY.
THE FA SHOULD GET A BREAK FROM THE HEAT AND PRECIP MID WEEK AS THE
COLD FRONT STALLS OUT SOUTH OF THE CWA. 850MB TEMPS COOL FROM THE
LOW 20S ON SUN/MON TO THE MID/UPPER TEENS TUE/WED. HIGH TEMPS TUE-
THU SHOULD BE IN THE LOW-UPPER 80S FROM N-S WITH LOWS WED/THU MRNGS
MAINLY IN THE 60S TO NEAR 70 IN THE STL METRO AREA. THE BNDRY IS
FCST TO LIFT BACK NORTH LATE WEEK AS THE UPPER LVL RIDGE EXPANDS
EAST AGAIN. THE GFS IS FASTER THAN THE ECMWF WITH THE UPPER LVL
HEIGHT RISES AND HENCE LIFTS THE BNDRY THRU FASTER AND IS QUICKER TO
REINTRODUCE A RETURN TO HOT TEMPS. THE ECMWF EVENTUALLY GETS TO A
SIMILAR SOLUTION BY NEXT WKND...IT JUST TAKES LONGER TO GET THERE.
THE END RESULT APPEARS TO BE ANOTHER POTENTIAL ROUND OF HEAT FOR
NEXT WKND WITH THE CAVEAT THAT THE FA WILL BE ON THE NE PERIPHERY OF
THE UPPER LVL HIGH CENTERED ACROSS THE SW CONUS MEANING WELL WITHIN
RANGE OF NIGHTTIME CONVECTION...WHICH COULD RUIN A GOOD TEMP
FCST...MUCH LIKE TODAY.
2%
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 122 AM CDT SUN JUL 19 2015
THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS EASTERN MISSOURI INTO
WEST CENTRAL AND SOUTHWEST ILLINOIS EARLY IN THE PERIOD. THIS WILL
AFFECT PRIMARILY KUIN WHERE I HAVE MOVED UP THE TEMPO GROUP FOR
TSRA. HAVE ALSO INCLUDED A VCTS AT THE ST. LOUIS METRO TAF SITES
WHERE A COMPLEX OF THUNDERSTORMS WILL MOVE JUST NORTHEAST OF THOSE
SITES. THE THUNDERSTORMS CURRENTLY OVER NORTHERN MISSOURI ARE
EXPECTED TO MOVE SOUTH AND MAY AFFECT KCOU BY 09Z.
THEN EXPECT A DRY PERIOD DURING THE LATE MORNING BEFORE THUNDERSTORMS
REDEVELOP DURING THE AFTERNOON AND EVENING HOURS.
SPECIFICS FOR KSTL:
HAVE VCTS EARLY ON HAS AS A COMPLEX OF THUNDERSTORMS WILL MOVE
NEAR THE AIRPORT. THEN EXPECT ANOTHER CHANCE OF THUNDERSTORMS
LATER THIS AFTERNOON AND THIS EVENING. OTHERWISE EXPECT DRY AND
VFR CONDITIONS.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR COLE MO-CRAWFORD
MO-FRANKLIN MO-GASCONADE MO-IRON MO-JEFFERSON MO-LINCOLN MO-
MADISON MO-MONITEAU MO-OSAGE MO-REYNOLDS MO-ST. CHARLES MO-
ST. FRANCOIS MO-ST. LOUIS CITY MO-ST. LOUIS MO-STE.
GENEVIEVE MO-WARREN MO-WASHINGTON MO.
IL...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR BOND IL-CALHOUN IL-
CLINTON IL-FAYETTE IL-GREENE IL-JERSEY IL-MACOUPIN IL-
MADISON IL-MARION IL-MONROE IL-MONTGOMERY IL-RANDOLPH IL-
ST. CLAIR IL-WASHINGTON IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
346 AM CDT SUN JUL 19 2015
.SYNOPSIS...
ISSUED AT 346 AM CDT SUN JUL 19 2015
AT 08Z...SKIES WERE MOSTLY CLEAR WEST OF ANW THROUGH IML WITH
TEMPERATURES IN THE WEST FROM THE MID 50S ERN PNHDL TO THE UPPER 60S
FAR ERN ZONES. SHOWER AND THUNDERSTORMS CONTINUE MAINLY ACROSS
KANSAS THIS HOUR.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM CDT SUN JUL 19 2015
TODAY AND TONIGHT...ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS
FORECAST TO MOVE INTO WESTERN NEBRASKA THIS AFTERNOON. WV IMAGERY
INDICATES THE PRESENCE OF A DISTURBANCE IN CENTRAL AZ WHICH WILL
FOLLOW THE PERIPHERY OF THE UPPER RIDGE INTO ERN CO BY LATE THIS
AFTERNOON. IN ADDITION...ANOTHER DISTURBANCE CURRENTLY LOCATED IN
NWRN WY WILL TRACK SOUTHEAST INTO WRN SD. THIS WILL DRIVE A COLD
FRONT THROUGH WRN SD AND THE WRN PNHDL OF NEBR BY LATE AFTERNOON
THEN THROUGH MOST OF THE FA OVERNIGHT. LOW CHC POPS ARE FORECAST WEST
OF A LINE FROM VTN THROUGH OGA AND IML BY LATE AFTERNOON. DEEP LAYER
SHEAR WILL AGAIN BE ADEQUATE AT 30 TO 35 KTS. SB CAPES OF 1500-2000
J/KG WILL EXIST. A FEW STRONG THUNDERSTORMS WILL BE POSSIBLE WEST OF
HWY 83 LATE THIS AFTERNOON...WITH STRONG THUNDERSTORMS THIS EVENING
FOR AREAS TO THE EAST. A FEW SEVERE STORMS MAY OCCUR IN SWRN NEBR
THIS EVENING. A LOOK AT MODEL SOUNDINGS SHOWS FAIRLY DRY BELOW
750MB...THEN QUITE MOIST ABOVE WITH PWAT VALUES NEAR 1.5 INCHES.
OVERALL IT LOOKS LIKE A BETTER THREAT FOR STRONG TO LOCAL DAMAGING
WINDS THAN FOR LARGE HAIL. THERE ARE MODEL DIFFERENCES IN
PLACEMENT OF CONVECTIVE PRECIPITATION. ONE AREA FOCUSES TONIGHT
ACROSS THE NRN HALF OF NCTRL NEBR WHILE A SECOND AREA IS FOCUSED
FROM THE SERN PNHDL INTO SWRN NEBR. SEE NO REASON THAT AT LEAST A
BROKEN LINE OF STORMS WILL NOT DEVELOP IN BETWEEN ACROSS CNTRL
PORTIONS OF THE FA. THEREFORE 30 TO 40 POPS ARE FORECAST FOR ALL
AREAS OVERNIGHT.
HIGHS TODAY SHOULD BE VERY UNIFORM FROM 86 TO 88 DEGREES ACROSS THE
FA AS DEWPOINTS RISE INTO THE LOW TO MID 60S NEAR AND EAT OF HWY 83
WITH UPPER 50S TO LOWER 60S TO THE WEST. WINDS THIS AFTERNOON TO
BECOME SOUTH TO SOUTHWEST AT AROUND 10 KTS. CURRENT SATELLITE
INDICATES SKIES MAY BEGIN THE DAY MOSTLY CLEAR IN THE WEST WITH
DECREASING CLOUDS EAST. BY LATE MORNING...CUMULUS CLOUDS TO FORM
WITH PARTLY CLOUDY SKIES INTO THE AFTERNOON.
LOWS TONIGHT KEPT VERY NEAR PREVIOUS FCST FROM THE UPPER 50S TO
LOWER 60S WEST TO NEAR 65 EAST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 346 AM CDT SUN JUL 19 2015
FORECAST CHALLENGE IN THE EXTENDED PERIODS WILL BE DETERMINING
TIMING AND CHANCES OF PRECIPITATION. THE MODELS AS OF LATE HAVE HAD
CONSISTENCY ISSUES...ESPECIALLY CONCERNING THE SMALLER SCALE
FEATURES. THUS BESIDES SOME MINOR SMOOTHING...THE CR_INT PROCEDURE
WAS LEFT AS IS. WHERE THE MODELS HAVE SHOWN CONSISTENCY IS WITH THE
PLACEMENT AND MAINTENANCE OF THE SUBTROPICAL RIDGE WHICH REMAINS
ACROSS THE SOUTHERN TIER OF THE UNITED STATES. WITH THE RIDGE TO
THE SOUTH...THE REGION WILL LARGELY BE INFLUENCED BY ZONAL FLOW
ALOFT...WHICH AT TIMES WILL SHIFT TO SW AS THE RIDGE AMPLIFIES
NORTH.
BEGINNING 12Z MONDAY...A FRONTAL BOUNDARY IS FORECAST TO REMAIN TO
THE SOUTH OF THE AREA...WITH POST FRONTAL HIGH PRESSURE BUILDING
SOUTHEAST INTO THE MID-MISSOURI VALLEY. THE POST FRONTAL CONDITIONS
WILL PROVIDE FOR AVERAGE TO SLIGHTLY BELOW AVERAGE HIGH TEMPERATURES
AND MAINLY DRY CONDITIONS. THE EXCEPTION POSSIBLY BEING ACROSS OUR
FAR WESTERN ZONES WHERE A FAIRLY ROBUST PV MAX IS SHOWN TO ADVANCE
EAST ALONG THE SODAK BORDER. CONVECTION ALONG THE FRONT ACROSS
KANSAS SHOULD LIMIT OUR PRECIP CHANCES ELSEWHERE.
THE RIDGE AMPLIFIES ATOP THE CENTRAL AND NORTHERN PLAINS
MID-WEEK...BUT SOUTHERLY FLOW ON THE BACKSIDE OF THE HIGH WILL HELP
INCREASE LOWER TROPOSPHERIC TD/S AND INSTABILITY. THE MODELS ARE
INDICATING ADDITIONAL PRECIPITATION CHANCES TUESDAY EVENING INTO
THURSDAY...TIED GENERALLY TO WEAK DISTURBANCES/PV ANOMALIES. TIMING
IS IN QUESTION...SO THE ENTIRE PERIOD WILL NOT BE A WASH...BUT AT
THIS POINT...WE CANNOT RULE OUT ANY PERIODS MID-WEEK. THE MODELS TREND
DRIER LATE WEEK AS INCREASING SUBSIDENCE AND WARMING TEMPERATURES
CAP CONVECTIVE CHANCES. HIGHS FRIDAY ARE LOOKING TO PUSH BACK INTO
THE MID TO POSSIBLY UPPER 90S FOR LOCATIONS ALONG AND SOUTH OF THE
INTERSTATE 80 CORRIDOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1220 AM CDT SUN JUL 19 2015
CLUSTER OF TSRA EXITING SWRN NEB ATTM PRETTY MUCH ACCORDING TO
PREV FCST AND IN LINE WITH EARLIER HRRR RUNS. SPC MESOANALYSIS
WOULD SUGGEST FURTHER DEVELOPMENT POSSIBLE ALONG KS/NEB BORDER IN
THE NEXT FEW HOURS...BUT GENERAL WEAKENING TREND IS ANTICIPATED IN
GENERAL. ANY PRECIP SHOULD BE WELL SOUTH OF KVTN.
WILL CONTINUE TO KEEP A MENTION OF STRATUS IN THE KLBF TAF THROUGH
THE MORNING HOURS..BUT CONFIDENCE IS LOWER THAT IT WOULD AFFECT
KVTN...SO LEFT AS SCT LAYER THERE. NEXT CHALLENGE IS TIMING OF NEXT
ROUND OF TSRA WITH A MORE SIGNIFICANT PV ANOMALY AND ASSOCIATED
FRONTAL BOUNDARY MOVING THROUGH SUNDAY EVE. MODELS DIFFER ON TIMING
OF THE UPPER FEATURE AND FRONTAL POSITION AS WELL...THOUGH MOST ARE
SIMILAR WITH THE IDEA OF TSRA DEVELOPING ALONG THE FRONT WITH LLJ
AIDING IN NOCTURNAL DEVELOPMENT...BUT LOCATION OF SMALL MCS WILL BE
DIFFICULT TO PIN DOWN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...JACOBS
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1220 AM CDT SUN JUL 19 2015
.SYNOPSIS...
ISSUED AT 340 PM CDT SAT JUL 18 2015
BROAD UPPER LEVEL RIDGE REMAINS ANCHORED ACROSS THE SOUTHERN PLAINS
AND SOUTHEASTERN CONUS. A TROUGH IS PUSHING ACROSS SOUTH CENTRAL
CANADA...WITH A SUBTLE TROUGH OVER THE PACIFIC NORTHWEST. TROPICAL
STORM DOLORES IN THE EASTERN PACIFIC WITH SOME MOISTURE FROM THE
SYSTEM COMBINING WITH A GOOD MOISTURE SURGE UP THE 4 CORNERS AND
INTO THE CENTRAL ROCKIES. MEANWHILE AT THE SFC A STALLED BOUNDARY
MEANDERING ACROSS MUCH OF KS AND BACK NORTHWEST ALONG THE FRONT
RANGE. BENEATH PARTLY TO MOSTLY SUNNY SKIES TEMPS GENERALLY INTO THE
80S THIS AFTERNOON.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 340 PM CDT SAT JUL 18 2015
MOISTURE CONTINUES TO ROTATE FROM THE SW WITH CLOUDS ON THE INCREASE
FROM THE WEST. WATER VAPOR SHOWING A SHORT WAVE TRACKING ACROSS
NORTHERN COLORADO AND FAR SOUTHEAST WYOMING. THIS WAVE HAS BEEN THE
FOCUS FOR THUNDERSTORMS ACROSS THE CENTRAL ROCKIES. THIS WILL
CONTINUE TO ROTATE AROUND THE RIDGE INTO SW NEB THIS EVENING AND
OVERNIGHT. AND WILL BE MONITORED FOR THUNDERSTORM ACTIVITY. ZERO TO
6 KM SHEAR IS GOOD AT 35 TO 40 KTS AND MUCAPE VALUES VARY BETWEEN
1500 TO 2500 J/KG DEPENDING ON MODEL...WHICH IS STILL DECENT.
THUNDERSTORMS WILL BE LATER THIS EVENING AND OVERNIGHT WHICH LESSENS
THE SFC BASED STORMS AND MORE LIKELY TO SEE ELEVATED ACTIVITY.
SLIGHT RISK OF SEVERE WITH LARGE HAIL THE BIGGEST CONCERN...HOWEVER
SOME WIND OR AN ISOLD TORNADO COULD BE POSSIBLE EARLY ON. PWATS AT
1.50 INCHES OR BETTER AND STORM MOTION IS AROUND 10 KTS SO HEAVY
RAINFALL WILL BE A CONCERN. YESTERDAY STORMS PRODUCED LOCAL AMOUNTS
IN EXCESS OF 3 INCHES...HOWEVER GENERALLY EXPECT STORMS TONIGHT TO
BE SW OF LAST NIGHT ACTIVITY.
TOMORROW HIGHS RETURN TO THE 80S AS THE STALLED BOUNDARY REMAINS TO
THE SOUTH. ALSO GOING TO SEE ANOTHER WAVE PUSH ACROSS THE ROCKIES
WITH A CONTINUED TAP TO PACIFIC MOISTURE. WILL MONITOR FOR ANOTHER
ROUND OF THUNDERSTORMS...POSSIBLY STRONG TO SEVERE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 340 PM CDT SAT JUL 18 2015
IN THE MID TERM SOLUTIONS MODELS IN FAIRLY GOOD AGREEMENT WITH
FLATTENED SOUTHERN PLAINS RIDGE AND CUTOFF LOW OFF THE CALIFORNIA
COAST. WATER VAPOR IMAGERY CONTINUES TO SHOW MID AND HIGH MOISTURE
STREAMING STREAMING FROM SYSTEM OFF BAJA AND ACROSS MEXICO
STREAMING ACROSS THE DESERT SOUTHWEST INTO CENTRAL PLAINS. SURFACE
HIGH WILL BE IN PLACE AGAIN ON SUNDAY WITH RETURN UPSLOPE FLOW
OVER THE SOUTHWEST ZONES INTO THE NEBRASKA PANHANDLE. ENERGY
CONTINUES TO BE EJECTED OUT OF THE TROUGH TO THE WEST. TIMING OF
WAVES CONTINUES AS A VARIABILITY IN THE FORECAST. BOUNDARY TO THE
SOUTH OVER KANSAS WILL BE KEY TO PRECIPITATION FORECAST. UPSLOPE
CONDITIONS PERSIST OVER WESTERN NEBRASKA AND BUFR SOUNDINGS
CONTINUE TO SHOW MID LEVEL CAP THROUGH THE EVENING WITH 1400
JOULES/ KILOGRAM AND WEAK SHEAR. PROGRESSIVE WAVE WITH
PRECIPITATION CHANCES ENDING FROM WEST TO EAST OVER NIGHT. HIGHS
IN THE 80S AND LOWS IN THE 60S. MONDAY RIDGE REBOUNDS BEHIND
EXITING WAVE TEMPERATURES RISE INTO THE UPPER 80S WITH SOME 90S
OVER SOUTHWEST NEBRASKA. HAVE CARRIED SOME SCHC POPS OVER
SOUTHWEST NEBRASKA BASED ON STATIONARY BOUNDARY OVER NORTHERN
KANSAS WITH LATE AFTERNOON HEATING. TUESDAY STRONGER SLOW MOVING AS
A MID LEVEL WAVE MOVES OUT OF THE TROUGH AND THROUGH THE ROCKIES
BRINGING HEIGHTENED CHANCES FOR PRECIPITATION TO WESTERN NEBRASKA
THROUGH THE DAY TUESDAY AND WEDNESDAY INTERACTING WITH A
STATIONARY BOUNDARY LYING ACROSS THE NEBRASKA SANDHILLS. HIGHS IN
THE 80S TUESDAY AND WEDNESDAY LOWS IN THE 60S. HIGHS RISING INTO
THE 90S THURSDAY THROUGH SATURDAY AND DRY AS RIDGE BUILDS BACK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1220 AM CDT SUN JUL 19 2015
CLUSTER OF TSRA EXITING SWRN NEB ATTM PRETTY MUCH ACCORDING TO
PREV FCST AND IN LINE WITH EARLIER HRRR RUNS. SPC MESOANALYSIS
WOULD SUGGEST FURTHER DEVELOPMENT POSSIBLE ALONG KS/NEB BORDER IN
THE NEXT FEW HOURS...BUT GENERAL WEAKENING TREND IS ANTICIPATED IN
GENERAL. ANY PRECIP SHOULD BE WELL SOUTH OF KVTN.
WILL CONTINUE TO KEEP A MENTION OF STRATUS IN THE KLBF TAF THROUGH
THE MORNING HOURS..BUT CONFIDENCE IS LOWER THAT IT WOULD AFFECT
KVTN...SO LEFT AS SCT LAYER THERE. NEXT CHALLENGE IS TIMING OF NEXT
ROUND OF TSRA WITH A MORE SIGNIFICANT PV ANOMALY AND ASSOCIATED
FRONTAL BOUNDARY MOVING THROUGH SUNDAY EVE. MODELS DIFFER ON TIMING
OF THE UPPER FEATURE AND FRONTAL POSITION AS WELL...THOUGH MOST ARE
SIMILAR WITH THE IDEA OF TSRA DEVELOPING ALONG THE FRONT WITH LLJ
AIDING IN NOCTURNAL DEVELOPMENT...BUT LOCATION OF SMALL MCS WILL BE
DIFFICULT TO PIN DOWN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MASEK
SHORT TERM...MASEK
LONG TERM...POWER
AVIATION...ROBERG
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
952 PM PDT SAT JUL 18 2015
.SYNOPSIS...RICH MOISTURE ASSOCIATED WITH NOW DECAYING HURRICANE
DOLORES CONTINUES TO PUSH INTO THE REGION INCREASING THE POTENTIAL
FOR HEAVY DOWNPOURS...FLASH FLOODING...AND STRONG DOWNBURST WINDS
THROUGH THIS EVENING. STORM CHANCES WILL BE GREATEST ACROSS SAN
BERNARDINO...CLARK...AND MOHAVE COUNTIES. MOISTURE WILL PUSH FARTHER
NORTH SUNDAY ENCOMPASSING THE ENTIRE AREA WITH CONTINUED FLASH FLOOD
POTENTIAL. MOISTURE WILL GRADUALLY DECREASE NEXT WEEK TOWARDS MORE
TYPICAL SUMMER VALUES BUT SLIGHT CHANCES FOR STORMS WILL REMAIN FOR
MANY AREAS THROUGH MIDWEEK.
&&
.UPDATE...EXTENSIVE CLOUD COVER ACROSS THE REGION THIS EVENING
HOWEVER LIGHT TO MODERATE SHOWER ACTIVITY WAS MAINLY LIMITED TO SAN
BERNARDINO, EASTERN CLARK AND MOHAVE COUNTIES AT 930 PM. THE OVERALL
MODEL TREND IS FOR A DECREASING CHANCE OF SHOWERS AND STORMS HEADING
THROUGH THE OVERNIGHT HOURS BUT WILL MAINTAIN A CHANCE IN MOST AREAS
THROUGH THE NIGHT. LOWERED THE LAS VEGAS VALLEY TO A SLIGHT CHANCE
OVERNIGHT BASED ON THE HRRR AND LATEST LOCAL MODEL OUTPUT SHOWING
MAINLY DRY CONDITIONS OVER CLARK COUNTY. THE FORECAST UPDATE IS OUT.
-SALMEN-
.AVIATION...FOR MCCARRAN...SHOWERS PASSING TO THE SOUTH OF THE
VALLEY HAS KEPT GUSTY SOUTH WINDS IN LONGER THAN EXPECTED HOWEVER
THEY ARE BEGINNING TO TREND DOWN AND SHOULD BE AROUND 8-12KTS OUT
OF THE SOUTH ALL NIGHT. OTHERWISE...SKY CONDITIONS BKN-OVC A0A 14K
FEET WITH AN ISOLATED SHOWER OR THUNDERSTORM POSSIBLE OVERNIGHT. IN
ADDITION...ALL APPROACH CORRIDORS WILL BE SUSCEPTIBLE TO ISOLATED OR
SCATTERED SHOWER AND THUNDERSTORM ACTIVITY THROUGH THE NIGHT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...THE BEST CHANCE OF SHOWERS AND THUNDERSTORMS WILL
CONTINUE ALONG THE SOUTHERN PORTIONS OF THE FORECAST AREA OVERNIGHT.
GENERALLY ALONG A KDAG-KLAS-KSGU LINE BUT ISOLATED STORMS WILL BE
POSSIBLE ELSEWHERE. BKN-OVC CONDITIONS ABOVE 10K POSSIBLE WITH AREAS
OF GUSTY AND ERRATIC SURFACE WINDS NEAR STORMS AS WELL AS POCKETS OF
CONVECTIVE TURBULENCE.
&&
.PREV DISCUSSION...
200 PM PDT SAT JUL 18 2015
.SHORT TERM FORECAST...
IMPULSE CURRENTLY WORKING ACROSS THE AREA IS PUSHING INTO A VERY
UNSTABLE ATMOSPHERE. ANOMALOUSLY MOIST ATMOSPHERE, UPPER LEVEL LIFT,
AND DESTABILIZATION THROUGH THE DAY HAVE ALLOWED THE RAPID RAMP UP
OF WIDESPREAD CONVECTION. EXPECT HEAVY RAINFALL, WITH RATES OF 2
INCHES PER HOUR. ALSO STRONG WINDS HAVE BEEN OBSERVED ACROSS
PORTIONS OF THE LAS VEGAS VALLEY AND EASTERN SAN BERNARDINO COUNTY.
A SEVERE THUNDERSTORM WATCH HAS BEEN ISSUED UNTIL 9 PM TONIGHT FOR
CLARK, LINCOLN, SAN BERNARDINO, AND MOHAVE COUNTIES. WE ARE ALSO
GETTING REDUCED VISIBILITY ON THE LEADING EDGE OF THESE STORMS AS
DUST IS KICKED UP. VISIBILITY MAY BE REDUCED BELOW A QUARTER MILE AT
TIMES. A DUST STORM WARNING IS CURRENTLY OUT FOR DEATH VALLEY WHERE
AREA WEBCAMS SHOWED VISIBILITY BELOW A QUARTER MILE. PLEASE BE
WEATHER AWARE THROUGH THIS EVENING AND DO NOT DRIVE THROUGH FLOODED
ROADWAYS!
EXPECT THE UPPER LEVEL FORCING TO WEAKEN AND SHIFT NORTHWARD
TOMORROW. WITH MOISTURE EXPECTED TO PUSH NORTH AS WELL, HAVE
EXPANDED THE FLASH FLOOD WATCH FOR ALL COUNTIES IN OUR FORECAST AREA
AND EXTENDED THE FLASH FLOOD WATCH THROUGH TOMORROW. SOME COUNTIES
MAY NEED TO BE EXTENDED INTO MONDAY AS WELL, BUT WILL FIGHT THAT
BATTLE LATER.
&&
.LONG TERM...MONDAY THROUGH FRIDAY.
MOISTURE WILL REMAIN ABUNDANT MONDAY AND IT IS POSSIBLE THE REMAINS
OF DOLORES AND ITS MID LEVEL CIRCULATION WILL DRIFT INTO SOUTHERN
CALIFORNIA AND COULD RESULT IN ANOTHER DAY OF FLASH FLOOD CONCERNS.
BY TUESDAY WE MAY BEGIN TO DRY OUT SOMEWHAT AS FLOW TURNS
SOUTHWESTERLY BUT OFTEN TIMES MODELS SCOUR OUT OUR MOISTURE TOO
QUICKLY...SO THIS IS SOMETHING THAT WILL NEED TO BE CONSIDERED. IN
FACT...THE GFS MAINTAINS ELEVATED PRECIPITABLE WATER VALUES THROUGH
WEDNESDAY AFTERNOON AND AM TEMPTED TO BELIEVE THIS GIVEN THE SEASONS
TREND OF MOISTURE RELUCTANT TO SCOUR OUT OF THE REGION AFTER A
MOISTURE PUSH. DIDNT MAKE SIGNIFICANT CHANGES TO THE EXTENDED RANGE
AS MY FOCUS WAS MORE ON THE SHORT TERM BUT POPS IN THE EXTENDED MAY
NEED TO BE RAISED THROUGH WEDNESDAY. AFTER WEDNESDAY MOSTLY DRY
CONDITIONS SHOULD PREVAIL BUT DEPENDING ON WHERE THE MONSOON HIGH
BUILDS BACK IN...THE BREAK MAY BE BRIEF WITH HINTS OF MORE PACIFIC
TROPICAL ACTIVITY AND A POSSIBLE RETURN OF A SOUTHERLY FLOW BY NEXT
WEEKEND.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE NEEDED
TODAY IN MOHAVE...SAN BERNARDINO...AND CLARK COUNTIES.
OTHERWISE...SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT
WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. &&
$$
SHORT TERM/AVIATION...PADDOCK
LONG TERM...OUTLER
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
428 PM EDT SUN JUL 19 2015
.SYNOPSIS...
A WARM AND UNSTABLE AIRMASS WILL CONTINUE TO BE IN PLACE TONIGHT
PRODUCING SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. SOME
THUNDERSTORMS MAY TURN SEVERE WITH DAMAGING WINDS...LARGE HAIL
AND HEAVY RAINFALL THIS EVENING. A COLD FRONT MOVES THROUGH
OVERNIGHT BRINGING AN END TO STRONG TO SEVERE THUNDERSTORMS.
QUIETER WEATHER EXPECTED ON MONDAY WITH A NOTICEABLE DECREASE IN
HUMIDITY LEVELS. ANOTHER DISTURBANCE MOVES THROUGH THE NORTH
COUNTRY ON TUESDAY. COOLER TEMPERATURES AND DAYTIME SHOWER
CHANCES THEN CONTINUE THROUGH THE REST OF THE WORKWEEK.
&&
.NEAR TERM /UNTIL 8 AM MONDAY MORNING/...
AS OF 426 PM EDT SUNDAY...SEVERE THUNDERSTORM WATCH 442 CONTINUES
FOR THE ENTIRE NORTH COUNTRY THROUGH 11 PM TONIGHT.
SPC MESOANALYSIS DEPICTS AN AIR MASS THAT IS QUITE UNSTABLE WITH
LIFTED INDICES IN THE -6 TO -8 RANGE, MLCAPE AROUND 2000-2500
J/KG, AND HARDLY ANY CONVECTIVE INHIBITION. THESE INSTABILITY
LEVELS BEING PRODUCED BY WARM/HUMID LOW-LEVEL AIRMASS, BUT ALSO A
COMPONENT OF STEEPER MID-LEVEL LAPSE RATES SAMPLED BY SPECIAL 18Z
DTX, BUF, AND ALY RAOBS. KINEMATICALLY, DEEP LAYER SHEAR VALUES
ARE AROUND 30-35 KTS BUT WITH FAVORABLE UPPER-LEVEL DIFFLUENCE.
SCATTERED MAINLY SUB- SEVERE THUNDERSTORMS HAVE DEVELOPED UP TO
THIS POINT ACROSS CENTRAL AND NORTHERN VERMONT INTO FAR NORTHERN
SECTIONS OF CLINTON, FRANKLIN AND ST. LAWRENCE COUNTIES IN NEW
YORK. HOWEVER, THERE ARE TWO OTHER AREAS OF STORMS: ONE OVER
CENTRAL AND SOUTHERN TIER OF NEW YORK AIDED BY A PRE-FRONTAL
CONFLUENCE TROUGH, AND THEN ACROSS ONTARIO CLOSER TO SURFACE COLD
FRONT AND ACCOMPANYING MID-LEVEL JETSTREAK OVER THE EASTERN GREAT
LAKES. PER THE HRRR AND HI-RES WRF ARW REFLECTIVITY, EACH OF THESE
AREAS ARE LIKELY TO AFFECT THE NORTH COUNTRY THROUGH THE EVENING.
SO EXPECT A CONTINUED INCREASE IN AREAL COVERAGE AND INTENSITY OF
STORMS OVER THE NEXT COUPLE OF HOURS, WITH DEEP LAYER SHEAR
INCREASING INTO THE 40-50 KT RANGE. EXPECT SOME TO BECOME SEVERE
WITH DAMAGING WINDS, LARGE HAIL AND HEAVY RAINFALL THE PRIMARY
CONVECTIVE HAZARDS.
LATER IN THE EVENING, EXPECT THE CLUSTER OF STORMS NOW GETTING
GOING NEAR TORONTO TO OVERSPREAD THE NORTH COUNTRY. A CONTINUED
RISK OF STRONG TO POSSIBLY DAMAGING WINDS WILL LIKELY CONTINUE AS
THIS SECOND AREA MOVES ACROSS.
IT WILL STILL BE QUITE MUGGY UNTIL THE COLD FRONT MOVES THROUGH
THE AREA, WHICH ISN`T LIKELY UNTIL AFTER MIDNIGHT. I`VE SHOWN LOWS
IN THE 60S, BUT HUMIDITY LEVELS WILL STEADILY DROP AFTER MIDNIGHT.
&&
.SHORT TERM /8 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 426 PM EDT SUNDAY...THE COLD FRONT MAY STILL BE CLEARING
FAR EASTERN VERMONT EARLY MONDAY MORNING. HOWEVER, MUCH QUIETER
WEATHER IS STILL ANTICIPATED FOR MONDAY AS SHORTWAVE RIDGING
BUILDS ACROSS THE NORTH COUNTRY. THOUGH 850 MB TEMPS WILL STILL BE
AROUND 14 TO 16C WITH MOSTLY SUNNY SKIES SUPPORTING HIGHS IN THE
80S, IT WILL BE NOTICEABLY LESS HUMID WITH DEWPOINTS BEING SOME 10
DEGREES LOWER THAN TODAY. COULD SEE THERE BEING AREAS OF FOG IN
THE FAVORED RIVER VALLEYS INTO TUESDAY EVENING WITH MORE
SEASONABLE LOWS IN THE 50S TO MID 60S.
NEXT SYSTEM APPROACHES FROM THE WEST ON TUESDAY AS A COLD FRONT
MOVES THROUGH. THE COLD FRONT ITSELF WILL BE MOVING INTO THE
AFTERNOON AND THERE IS SUFFICIENT ENOUGH DEEP-LAYER SHEAR TO
SUPPORT SUSTAINED THUNDERSTORMS. HOWEVER, INSTABILITY REMAINS IN
QUESTION. FORECAST NAM SOUNDINGS GENERATE THE MOST - ON THE ORDER
OF 1500 J/KG CAPE - BUT DEWPOINTS IN THE UPPER 60S WOULD BE
REQUIRED TO REALIZE THIS LEVEL OF CAPE WHICH DON`T SEEM REALISTIC.
ON THE OTHER HAND, THE GFS FORECAST SOUNDINGS PRODUCE CAPE VALUES
LESS THAN 500 J/KG. I THINK THE TRUTH MAY BE SOMEWHERE IN THE
MIDDLE OF THESE TWO SOLUTIONS, SO I`VE GONE WITH LIKELY POPS FOR
SHOWERS BUT CHANCE THUNDER. IT`S SOMETHING THAT WILL REQUIRE
MONITORING AS WE GO FORWARD. COLD FRONT MOVES ACROSS THE REGION
LATER TUESDAY/TUESDAY NIGHT WITH A DECREASE IN POPS INTO TUESDAY
NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 106 PM EDT SUNDAY...WITH PROSPECTS FOR STRONG CONVECTION
LATER TODAY, I`VE WORKED UP AN EXTENDED PORTION OF THE FORECAST
EARLY, LARGELY USING BLENDED GUIDANCE AND INCORPORATING 12Z/19TH
GFS. IN GENERAL, THERE REALLY ISN`T MUCH CHANGE COMPARED TO THE
PRIOR FORECAST. THE NORTH COUNTRY WILL BE UNDER INFLUENCE OF
CYCLONIC FLOW ALOFT AND THE EFFECTS OF 1000-500MB THICKNESS
TROUGHING WEDNESDAY THROUGH SATURDAY. IN THIS LARGE- SCALE REGIME,
EXPECT THERE TO BE PERIODS OF PARTLY TO MOSTLY CLOUDY SKIES AND
MAINLY DIURNAL/INSTABILITY SHOWERS WITH GREATER AREAL COVERAGE
NEAR THE MOUNTAINS. EXPECT TEMERATURES TO RUN BELOW LATE-JULY
NORMALS GIVEN COVERAGE OF DIURNAL CLOUDS AND COLDER THEMRAL
PROFILES. IT`S NOT UNTIL LATER SATURDAY THAT THE PATTERN BEGINS TO
CHANGE TO A RETURN TO WARMER WEATHER.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
THROUGH 18Z MONDAY...CURRENTLY ALL STATIONS ARE VFR AFTER THE
VARIOUS SHOWERS AND THUNDERSTORMS EARLIER THIS MORNING WITH WINDS
OUT OF THE SOUTHWEST AT 05-10 KNOTS WITH PBG BEING THE EXCEPTION
AT SOUTHEASTERLY AT 10-15.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE LIKELY TO
REDEVELOP ACROSS NORTHERN NEW YORK AND VERMONT BETWEEN 18-00Z.
SOME OF THE THUNDERSTORMS CAN REDUCE CONDITIONS ON STATION TO IFR
AS THEY PASS THROUGH. ACTIVITY DIMINISHES FROM WEST TO EAST
BETWEEN 01Z AND 04Z FOLLOWED BY PARTLY CLOUDY SKIES AND VFR
CONDITIONS. COULD BE SOME PATCHY IFR IN FOG AND LOW CLOUDS
OVERNIGHT...WITH BEST CHANCE OF OCCURRENCE AT MPV/SLK.
WINDS SOUTH TO SOUTHWEST 8 TO 12 KNOTS WITH SOME GUSTS 15-20
KNOTS TODAY.
OUTLOOK 18Z MONDAY THROUGH FRIDAY...
18Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL
MPV/SLK.
12Z TUE - 00Z FRI...MAINLY VFR. CHANCE AFTERNOON SHOWERS EACH DAY
WITH BRIEF PERIODS OF MVFR. CHANCE THUNDERSTORMS TUESDAY PM.
&&
.MARINE...
SHOWERS WITH EMBEDDED THUNDERSTORMS ARE CURRENTLY MOVING ACROSS
THE CHAMPLAIN VALLEY. A LAKE THUNDERSTORM ADVISORY IS IN EFFECT
THROUGH THE MORNING AS THE SHOWERS AND SCATTERED THUNDERSTORMS
IMPACT THE LAKE AREA. WINDS AND WAVES MAY BE LOCALLY HIGHER IN THE
VICINITY OF THUNDERSTORMS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...LOCONTO
NEAR TERM...LOCONTO
SHORT TERM...LOCONTO
LONG TERM...LOCONTO
AVIATION...MV
MARINE...WFO BTV
AREA FORECAST DISCUSSION
NWS BUFFALO NY
330 PM EDT SUN JUL 19 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA THIS EVENING WITH SCATTERED TO
NUMEROUS THUNDERSTORMS. SOME OF THESE STORMS MAY PRODUCE STRONG
WINDS...HAIL...AND TORRENTIAL RAINFALL. SKIES WILL CLEAR ON MONDAY
AS WEAK HIGH PRESSURE BUILDS INTO THE REGION. ANOTHER COLD FRONT MAY
BRING A FEW SCATTERED SHOWERS AND STORMS TUESDAY. THIS WILL BE
FOLLOWED BY MAINLY DRY AND LESS HUMID WEATHER FOR THE REST OF THE
WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
SATELLITE IMAGERY SHOWING AGITATED CUMULUS FIELDS ACROSS THE WESTERN
SOUTHERN TIER...CENTRAL NY...AND THE SAINT LAWRENCE VALLEY WITH
MODERATE TO STRONG INSTABILITY DEVELOPING. WELL DEVELOPED STABLE
LAKE SHADOWS ARE EVIDENT IN VISIBLE SATELLITE IMAGERY...AND THESE
SHOULD KEEP THE NIAGARA FRONTIER AND JEFFERSON COUNTY DRY THROUGH
6PM. THE SPECIAL 18Z KBUF SOUNDING STILL SHOWS A FEW WEAK INVERSION
LAYERS AT 850MB AND 700MB WHICH ARE AIDING IN PROVIDING SOME CAPPING
TO DEEP MOIST CONVECTION. THE STRONG SURFACE HEATING WILL CONTINUE
TO GROW SURFACE BASED INSTABILITY THROUGH LATE AFTERNOON...AND
EVENTUALLY SOME UPDRAFTS WILL BREACH THE CAP WHERE LOW LEVEL
CONVERGENCE IS MAXIMIZED.
THROUGH LATE AFTERNOON EXPECT MOST OF THE INITIAL CONVECTION TO
FOCUS ON THE FINGER LAKES AND CENTRAL NY WHERE THE GREATEST
INSTABILITY IS FOUND...AND ALSO WHERE A SUBTLE BAND OF LOW LEVEL
CONVERGENCE IS NOTED IN SURFACE OBSERVATIONS. AT THE SAME TIME
ANOTHER BAND OF STORMS WILL DEVELOP ACROSS SOUTHERN ONTARIO JUST
AHEAD OF A WEAK SURFACE COLD FRONT. THIS BAND OF STORMS WILL FORM IN
AN ENVIRONMENT WITH STRONGER LARGE SCALE ASCENT JUST AHEAD OF A MID
LEVEL TROUGH AND SURFACE FRONT. THESE STORMS ACROSS SOUTHERN ONTARIO
SHOULD BE ABLE TO CROSS INTO WESTERN AND NORTH CENTRAL NY DURING THE
EARLY TO MID EVENING...BY WHICH TIME THE STABLE LAKE SHADOWS WILL BE
WEAKENING.
SEVERE POTENTIAL...MODEL POINT SOUNDINGS AND OBSERVATIONS SUGGEST
STRONG INSTABILITY DURING THE LATE AFTERNOON AND EVENING WITH SPC
OBJECTIVE RUC ANALYSIS SHOWING GREATER THAN 3000 J/KG OF SBCAPE
AVAILABLE. DEEP LAYER 0-6KM SHEAR OF 35-40 KNOTS WILL OVERSPREAD THE
AREA AHEAD OF A MID LEVEL SHORTWAVE MOVING OUT OF THE CENTRAL GREAT
LAKES...WITH LOW LEVEL SHEAR ALSO FAVORABLE ESPECIALLY ALONG THE
LAKE BREEZE BOUNDARIES. THE COMBINATION OF SHEAR AND INSTABILITY
SUPPORTS SEVERAL STORM MODES INCLUDING ORGANIZED MULTICELL
CLUSTERS...SUPERCELLS...AND SHORT BOWING LINE SEGMENTS. EXPECT
INITIAL ISOLATED TO SCATTERED STORMS TO TEND TO EVOLVE INTO SHORT
BOWING SEGMENTS THROUGH THE EVENING AS CONVECTIVE COLD POOLS GROW
AND BECOME SHARED. THE MAIN RISK WILL BE ISOLATED DAMAGING WINDS...
WITH A SECONDARY RISK OF LARGE HAIL.
FLASH FLOOD POTENTIAL...PWAT VALUES PEAK AT AROUND 1.8 INCHES JUST
AHEAD OF THE FRONT. MODERATE MID LEVEL WIND FIELDS SHOULD KEEP
STORMS MOVING ALONG FOR THE MOST PART...ALTHOUGH CORFIDI VECTORS
SUGGEST SOME POTENTIAL FOR BACKBUILDING ESPECIALLY ALONG ANY
MESOSCALE BOUNDARIES THAT DEVELOP. THE MAIN CONCERN HOWEVER IS THE
VERY WET ANTECEDENT CONDITIONS FROM HEAVY RAIN OVER THE PAST FEW
WEEKS. THE MOST SUSCEPTIBLE AREA WILL BE THE WESTERN SOUTHERN TIER
AND FINGER LAKES WHERE VERY HEAVY RAIN FELL LAST WEEK. LOCAL AMOUNTS
OF 1.5 INCHES IN AN HOUR ARE POSSIBLE GIVEN THE ENVIRONMENT...AND
THIS WOULD RESULT IN SOME PROBLEMS ESPECIALLY FOR THE AREAS WITH
SATURATED GROUND.
OVERNIGHT THE SHOWERS AND STORMS WILL TAPER OFF FROM NORTHWEST TO
SOUTHEAST FOLLOWING THE PASSAGE OF A WEAK SURFACE COLD FRONT. CLOUDS
WILL LINGER BEHIND THE FRONT...ESPECIALLY ACROSS THE HIGHER TERRAIN
WHERE MOIST NORTHWEST UPSLOPE FLOW WILL PROMOTE STRATUS LATE TONIGHT
AND EARLY MONDAY. ALSO EXPECT SOME FOG ACROSS THE HIGHER TERRAIN OF
THE WESTERN SOUTHERN TIER LATE TONIGHT AND EARLY MONDAY.
ANY FOG AND LOW STRATUS ACROSS HIGHER TERRAIN WILL MIX OUT BY MID TO
LATE MORNING MONDAY. THIS WILL LEAVE PLENTY OF SUNSHINE WITH JUST A
FEW SCATTERED DIURNAL CUMULUS ALONG AND INLAND OF THE LAKE BREEZE
BOUNDARIES FOR THE AFTERNOON. THE AIRMASS IS STILL QUITE WARM EVEN
BEHIND THE COLD FRONT...SO EXPECT HIGHS IN THE LOW TO MID 80S ACROSS
LOWER ELEVATIONS AND AROUND 80 ON THE HILLS. THE AIRMASS WILL BE
NOTICEABLY LESS HUMID THAN THE PAST FEW DAYS HOWEVER AS A PUSH OF
DRIER AIR ARRIVES FROM THE NORTH.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
A COLD FRONT WILL APPROACH OUR REGION FROM THE UPPER GREAT LAKES ON
MONDAY NIGHT...FOLLOWED BY A SHORTWAVE ON TUESDAY. THERE IS LIMITED
MOISTURE AND THE CONSENSUS TIMING FOR THIS FRONTAL PASSAGE IS LATE
MONDAY NIGHT WHICH IS DIURNALLY UNFAVORABLE FOR CONVECTION. QPF
GUIDANCE SUGGESTS THERE WILL BE AT LEAST SOME ACTIVITY WITH OUR
FORECAST CARRYING A CHANCE OF SHOWERS AND THUNDERSTORMS WHICH
FOCUSES ALONG THE FRONTAL BOUNDARY. THE FRONT SHOULD DROP SOUTH AND
EAST OF THE AREA ON TUESDAY WITH DIMINISHING SHOWERS TUESDAY
AFTERNOON. THE EXCEPTION IS EAST OF LAKE ONTARIO WHERE LIMITED
DIURNAL INSTABILITY AND THE CLOSER PROXIMITY OF THE SHORTWAVE MAY
SPARK A FEW MORE SHOWERS OR THUNDERSTORMS TUESDAY AFTERNOON AND
EARLY EVENING. CLOUDS MAY LINGER A BIT LONGER THAN GUIDANCE SUGGESTS
ON TUESDAY DUE TO THE NORTHERLY UPSLOPE FLOW...WITH PERHAPS A BRIEF
PERIOD OF FOG/STRATUS TUESDAY MORNING TUE TO UPSLOPING.
AFTER THIS...HIGH PRESSURE ACROSS THE OHIO VALLEY WILL RIDGE INTO
OUR REGION WHILE AN UPPER LEVEL LOW WILL STALL ACROSS QUEBEC. FOR
THE MOST PART THIS SHOULD BRING DRY WEATHER BUT THERE IS A SMALL
CHANCE OF DIURNALLY DRIVEN SHOWERS EAST OF LAKE ONTARIO WEDNESDAY
AFTERNOON. THIS SHOULD ALSO BRING BELOW NORMAL TEMPERATURES...WITH
DAYTIME HIGHS IN THE 70S EACH DAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
FOR THE MAJORITY OF THE LONG TERM PERIOD THE REGION WILL BE ON THE
WESTERN FRINGE OF THE 500 MB TROUGH AXIS WHICH IS FORECAST TO REMAIN
ACROSS NEW ENGLAND. THIS WILL BE A FAIRLY COOL AND DRY FLOW WITH
SLIGHTLY BELOW NORMAL TEMPERATURES AND MOSTLY DRY WEATHER. THE
EXCEPTION WILL BE A SLIGHT CHANCE FOR DIURNALLY DRIVEN SHOWERS
ACROSS THE EASTERN LAKE ONTARIO REGION WHICH WILL BE CLOSEST TO THE
TROUGH. OTHERWISE...OUTSIDE OF SOME AFTERNOON CUMULUS EXPECT MOSTLY
CLEAR SKIES AND FAIRLY LARGE DIURNAL TEMPERATURE SWINGS. THERE IS
FAIRLY GOOD AGREEMENT AMONG GFS/GGEM/ECMWF MODEL GUIDANCE DURING
THIS PERIOD...WITH A PRETTY NICE STRETCH OF MID-SUMMER WEATHER
WEDNESDAY NIGHT THROUGH SATURDAY TIME PERIOD.
THIS TROUGH AXIS WILL SLIDE EAST LATE SATURDAY WHICH WILL SET UP A
MORE WESTERLY FLOW ALOFT. GFS/ECMWF GUIDANCE BOTH FORECAST A WAVE TO
CROSS THE REGION IN THE SATURDAY NIGHT OR SUNDAY TIME FRAME...WHICH
WILL BRING A GOOD CHANCE FOR SHOWERS AND THUNDERSTORMS.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
EXTENSIVE CUMULUS FIELDS HAVE DEVELOPED ALONG AND INLAND FROM THE
LAKE BREEZE BOUNDARIES THIS AFTERNOON WITH LOWER END VFR CIGS ACROSS
HIGHER TERRAIN. STABLE LAKE SHADOWS ARE EVIDENT NORTHEAST OF BOTH
LAKES WITH LITTLE CLOUD COVER...AND THIS WILL HOLD THROUGH THE END
OF THE AFTERNOON.
A FEW WIDELY SCATTERED SHOWERS AND STORMS WILL DEVELOP LATE THIS
AFTERNOON FROM THE SOUTHERN TIER THROUGH THE FINGER LAKES AND
CENTRAL NY ON LAKE BREEZE BOUNDARIES. A BETTER CHANCE OF SHOWERS AND
STORMS WILL ARRIVE ALONG AND AHEAD OF A COLD FRONT THIS EVENING. BY
THIS TIME THE STABLE LAKE SHADOWS WILL BE WEAKENING...SO THE STORMS
WILL HAVE A BETTER CHANCE OF IMPACTING MOST OF THE TAF SITES FROM
ABOUT 23Z-03Z. ANY OF THE STORMS WILL PRODUCE BRIEF MVFR/IFR
CONDITIONS AND A FEW MAY CONTAIN GUSTY WINDS AND HAIL.
THE STORMS WILL END FROM NORTHWEST TO SOUTHEAST OVERNIGHT WITH THE
PASSAGE OF THE WEAK COLD FRONT. THERE SHOULD BE A FEW HOURS OF IFR
CIGS ACROSS HIGHER TERRAIN LATE TONIGHT AND EARLY MONDAY MORNING
BEHIND THE FRONT IN RESPONSE TO MOIST NORTHWEST UPSLOPE FLOW. ALSO
EXPECT AREAS OF FOG ACROSS THE HIGHER TERRAIN OF THE WESTERN
SOUTHERN TIER WITH IFR VSBY. THE FOG AND LOW STRATUS SHOULD MIX OUT
BY MID MORNING MONDAY AND LEAVE VFR TO PREVAIL THE REST OF THE DAY
WITH SCT DIURNAL CUMULUS ALONG AND INLAND OF LAKE BREEZE BOUNDARIES.
OUTLOOK...
TUESDAY...MAINLY VFR WITH A CHANCE OF BRIEF MVFR/IFR IN SCATTERED
SHOWERS AND STORMS.
WEDNESDAY THROUGH FRIDAY...MAINLY VFR.
&&
.MARINE...
A COLD FRONT WILL CROSS THE AREA THIS EVENING WITH SCATTERED TO
NUMEROUS THUNDERSTORMS. SOME OF THESE STORMS WILL PRODUCE LOCALLY
HIGHER WINDS AND WAVES. ANOTHER COLD FRONT WILL BRING A FEW
SCATTERED STORMS ON TUESDAY AS WELL.
OTHERWISE EXPECT WINDS TO GENERALLY RUN 15 KNOTS OR LESS WITH WAVES
2 FEET OR LESS THROUGH MUCH OF THE UPCOMING WEEK AS THE PRESSURE
GRADIENT REMAINS RELATIVELY WEAK ACROSS THE LOWER LAKES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR NYZ001>006-
010>014-019>021-085.
MARINE...NONE.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK
SHORT TERM...APFFEL
LONG TERM...APFFEL
AVIATION...HITCHCOCK
MARINE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
108 PM EDT SUN JUL 19 2015
.SYNOPSIS...
MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY OUT AHEAD OF
APPROACHING COLD FRONT WHICH WILL CROSS THE REGION OVERNIGHT. SOME
STORMS MAY BE STRONG. WEAK HIGH PRESSURE WILL BUILD OVER THE
REGION ON MONDAY AHEAD OF ANOTHER APPROACHING COLD FRONT ON
TUESDAY WHICH WILL BRING MORE SHOWERS AND THUNDERSTORMS. COOLER
WEATHER WITH SCATTERED SHOWERS WILL FOLLOW FOR THE REST OF THE
WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 925 AM EDT SUNDAY...
A ROUND OF STORMS AND THUNDERSTORMS IS CURRENTLY MOVING EASTWARD
ACROSS THE NORTHER TIER OF THE FORECAST AREA AND SO I JUST MADE A
QUICK UPDATE TO ENHANCED THE AREA WHERE SHOWERS ARE OCCURRING
BLENDING IN THE LATEST HRRR GUIDANCE BECAUSE IT CAPTURES THE
REFLECTIVITY THE BEST. MOVING FORWARD TODAY EXPECT A SECOND
STRONGER ROUND OF SHOWERS TO DEVELOP LEADING TO AN ENHANCED
THREAT OF STRONG STORMS CAPABLE OF PRODUCING GUSTY WINDS AND
LOCALLY HEAVY RAINFALL.
PREVIOUS DISCUSSION AS OF 511 AM...EARLY MORNING FOG WILL LIFT
THIS MORNING SHORTLY AFTER SUNRISE AS DAYTIME HEATING BEGINS. A
COUPLE ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY.
FIRST ROUND OF SHOWERS IS ASSOCIATED WITH ONGOING CONVECTION
DURING THE OVERNIGHT WHICH IS OCCURRING IN ONTARIO AND QUEBEC.
EXPECT THESE SHOWERS TO MOVE ACROSS OUR AREA DURING THE EARLY
MORNING HOURS...AND THEN A SECOND ROUND OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AHEAD OF COLD FRONT. AN UPPER LEVEL
TROF WILL MOVE EASTWARD FROM THE GREAT LAKES REGION. SURFACE
DEWPOINTS ARE VERY HIGH TODAY...UPPER 60S TO LOWER 70S...AND THIS
WILL RESULT IN MODERATE TO STRONG INSTABILITY IN THE AFTERNOON.
FORECAST SOUNDINGS ARE INDICATING UP TO 35 KTS OF DEEP LAYER
SHEAR. VERY MOIST AIR IS ALSO IN PLACE AS IS EVIDENT FROM PWATS
AROUND 1.75 INCHES IN THE NAM PROFILES. DURING THE LATE AFTERNOON
A PIECE OF EML DRIFTS JUST SOUTH OF OUR FORECAST AREA...AND
CROSSING NEW ENGLAND OVERNIGHT.
UNFORTUNATELY NOT MUCH AGREEMENT BETWEEN MESOSCALE MODELS FOR
TODAY...BUT HRRR SHOWS AREA OF SHOWERS AND THUNDERSTORMS CURRENTLY
OVER THE BORDER OF ONTARIO AND QUEBEC WILL DROP SOUTHEASTWARD
ACROSS OUR NORTHERN ZONES DURING THE MORNING HOURS. A LITTLE
CONCERNED THAT HAVING MORNING CONVECTION AROUND COULD LIMIT
AFTERNOON CONVECTION IF THERE IS NO CLEARING FOLLOWING FIRST ROUND
OF CONVECTION. BUT...LOOKS LIKE THERE ARE ENOUGH FACTORS POINTING
TOWARDS AN AFTERNOON ROUND OF SHOWERS AND THUNDERSTORMS...STRONG
TO SEVERE...THEREFORE HAVE CONTINUED WITH ENHANCED WORDING IN THE
GRIDS. SPC ALSO HAS OUR REGION IN SLIGHT RISK ARE FOR TODAY.
ANOTHER POINT ABOUT MORNING CONVECTION IS THAT IF STORMS ARE
MAINTAINING DURING THE EARLY MORNING HOURS WITHOUT THE HELP OF
DAYTIME HEATING...THERE`S PROBABLY SOME DECENT INSTABILITY AND
FORCING MECHANISMS IN PLACE. MODELS CONTINUE TO SHOW A LOT OF CAPE
OVER THE REGION...AND TODAY LOOKS LIKE OUR DEWPOINTS ARE ACTUALLY
HIGH ENOUGH TO SUPPORT THIS...UNLIKE YESTERDAY. FEEL FAIRLY
CONFIDENT THAT THERE WILL BE STORMS AROUND THIS AFTERNOON INTO THE
EVENING HOURS...BUT TIMING IS TOUGH TO ZERO IN ON AT THIS TIME.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH TUESDAY NIGHT/...
AS OF 511 AM EDT SUNDAY...STORMS CONTINUE TONIGHT AHEAD OF THE
COLD FRONT WHERE SHEAR WILL INCREASE. HIGH PWATS IN PLACE AND
PIECE OF EML PASSING SOUTH OF OUR AREA. FEEL THE MAIN THREAT WILL
BE STRONG WINDS AND HEAVY RAIN. BTV4 SHOWS A LINE OF STORMS
CROSSING OUR FORECAST AREA FROM NORTHWEST TO SOUTHEAST FROM
00-06Z. STORMS SHOULD DIE DOWN FOLLOWING FRONTAL PASSAGE
TONIGHT...AND MONDAY WILL MAINLY BE DRY BUT STILL WARM AS A WEAK
RIDGE OF HIGH PRESSURE BUILDS OVER THE AREA. MONDAY NIGHT WILL
ALSO FEATURE DRY WEATHER...THEN TUESDAY ANOTHER STRONGER COLD
FRONT WILL CROSS OUR FORECAST AREA BRINGING YET MORE SHOWERS AND
THUNDERSTORMS TO THE NORTH COUNTRY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 106 PM EDT SUNDAY...WITH PROSPECTS FOR STRONG CONVECTION
LATER TODAY, I`VE WORKED UP AN EXTENDED PORTION OF THE FORECAST
EARLY, LARGELY USING BLENDED GUIDANCE AND INCORPORATING 12Z/19TH
GFS. IN GENERAL, THERE REALLY ISN`T MUCH CHANGE COMPARED TO THE
PRIOR FORECAST. THE NORTH COUNTRY WILL BE UNDER INFLUENCE OF
CYCLONIC FLOW ALOFT AND THE EFFECTS OF 1000-500MB THICKNESS
TROUGHING WEDNESDAY THROUGH SATURDAY. IN THIS LARGE- SCALE REGIME,
EXPECT THERE TO BE PERIODS OF PARTLY TO MOSTLY CLOUDY SKIES AND
MAINLY DIURNAL/INSTABILITY SHOWERS WITH GREATER AREAL COVERAGE
NEAR THE MOUNTAINS. EXPECT TEMERATURES TO RUN BELOW LATE-JULY
NORMALS GIVEN COVERAGE OF DIRUNAL CLOUDS AND COLDER THEMRAL
PROFILES. IT`S NOT UNTIL LATER SATURDAY THAT THE PATTERN BEGINS TO
CHANGE TO A RETURN TO WARMER WEATHER.
&&
.AVIATION /17Z SUNDAY THROUGH FRIDAY/...
THROUGH 12Z MONDAY...A VARIETY OF FLIGHT CATEGORIES EARLY THIS
MORNING WITH SOME AREAS OF LOW CLOUDS AND FOG...AND ALSO A FEW
SCATTERED SHOWERS AND THUNDERSTORMS. IFR AT MPV IN FOG TILL AROUND
13Z. TSRA PSBL AT MSS AND PBG TILL AROUND 14Z. ELSEWHERE...CONDITIONS
MAINLY VFR WITH AREAS OF MVFR THIS MORNING.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE LIKELY TO
REDEVELOP ACROSS NORTHERN NEW YORK AND VERMONT BETWEEN 16-19Z.
ATTM ONLY VCSH IN TAF DUE TO TIMING/COVERAGE UNCERTAINTIES.
ACTIVITY DIMINISHES FROM WEST TO EAST BETWEEN 01Z AND 05Z
FOLLOWED BY PARTLY CLOUDY SKIES AND VFR CONDITIONS. COULD BE SOME
PATCHY IFR IN FOG AND LOW CLOUDS OVERNIGHT...WITH BEST CHANCE OF
OCCURRENCE AT MPV/SLK.
WINDS SOUTH TO SOUTHWEST 8 TO 12 KNOTS WITH SOME GUSTS 15-20
KNOTS TODAY.
OUTLOOK 12Z MONDAY THROUGH THURSDAY...
12Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL MPV/SLK.
12Z TUE - 00Z FRI...MAINLY VFR. CHANCE AFTERNOON SHOWERS EACH DAY
WITH BRIEF PERIODS OF MVFR. CHANCE THUNDERSTORMS TUESDAY PM.
&&
.MARINE...
SHOWERS WITH EMBEDDED THUNDERSTORMS ARE CURRENTLY MOVING ACROSS
THE CHAMPLAIN VALLEY. A LAKE THUNDERSTORM ADVISORY IS IN EFFECT
THROUGH THE MORNING AS THE SHOWERS AND SCATTERED THUNDERSTORMS
IMPACT THE LAKE AREA. WINDS AND WAVES MAY BE LOCALLY HIGHER IN THE
VICINITY OF THUNDERSTORMS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...DEAL
SHORT TERM...NEILES
LONG TERM...LOCONTO
AVIATION...RJS
MARINE...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
936 AM EDT SUN JUL 19 2015
.SYNOPSIS...
MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY OUT AHEAD OF
APPROACHING COLD FRONT WHICH WILL CROSS THE REGION OVERNIGHT. SOME
STORMS MAY BE STRONG. WEAK HIGH PRESSURE WILL BUILD OVER THE
REGION ON MONDAY AHEAD OF ANOTHER APPROACHING COLD FRONT ON
TUESDAY WHICH WILL BRING MORE SHOWERS AND THUNDERSTORMS. COOLER
WEATHER WITH SCATTERED SHOWERS WILL FOLLOW FOR THE REST OF THE
WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 925 AM EDT SUNDAY...
A ROUND OF STORMS AND THUNDERSTORMS IS CURRENTLY MOVING EASTWARD
ACROSS THE NORTHER TIER OF THE FORECAST AREA AND SO I JUST MADE A
QUICK UPDATE TO ENHANCED THE AREA WHERE SHOWERS ARE OCCURRING
BLENDING IN THE LATEST HRRR GUIDANCE BECAUSE IT CAPTURES THE
REFLECTIVITY THE BEST. MOVING FORWARD TODAY EXPECT A SECOND
STRONGER ROUND OF SHOWERS TO DEVELOP LEADING TO AN ENHANCED
THREAT OF STRONG STORMS CAPABLE OF PRODUCING GUSTY WINDS AND
LOCALLY HEAVY RAINFALL.
PREVIOUS DISCUSSION AS OF 511 AM...EARLY MORNING FOG WILL LIFT
THIS MORNING SHORTLY AFTER SUNRISE AS DAYTIME HEATING BEGINS. A
COUPLE ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY.
FIRST ROUND OF SHOWERS IS ASSOCIATED WITH ONGOING CONVECTION
DURING THE OVERNIGHT WHICH IS OCCURRING IN ONTARIO AND QUEBEC.
EXPECT THESE SHOWERS TO MOVE ACROSS OUR AREA DURING THE EARLY
MORNING HOURS...AND THEN A SECOND ROUND OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AHEAD OF COLD FRONT. AN UPPER LEVEL
TROF WILL MOVE EASTWARD FROM THE GREAT LAKES REGION. SURFACE
DEWPOINTS ARE VERY HIGH TODAY...UPPER 60S TO LOWER 70S...AND THIS
WILL RESULT IN MODERATE TO STRONG INSTABILITY IN THE AFTERNOON.
FORECAST SOUNDINGS ARE INDICATING UP TO 35 KTS OF DEEP LAYER
SHEAR. VERY MOIST AIR IS ALSO IN PLACE AS IS EVIDENT FROM PWATS
AROUND 1.75 INCHES IN THE NAM PROFILES. DURING THE LATE AFTERNOON
A PIECE OF EML DRIFTS JUST SOUTH OF OUR FORECAST AREA...AND
CROSSING NEW ENGLAND OVERNIGHT.
UNFORTUNATELY NOT MUCH AGREEMENT BETWEEN MESOSCALE MODELS FOR
TODAY...BUT HRRR SHOWS AREA OF SHOWERS AND THUNDERSTORMS CURRENTLY
OVER THE BORDER OF ONTARIO AND QUEBEC WILL DROP SOUTHEASTWARD
ACROSS OUR NORTHERN ZONES DURING THE MORNING HOURS. A LITTLE
CONCERNED THAT HAVING MORNING CONVECTION AROUND COULD LIMIT
AFTERNOON CONVECTION IF THERE IS NO CLEARING FOLLOWING FIRST ROUND
OF CONVECTION. BUT...LOOKS LIKE THERE ARE ENOUGH FACTORS POINTING
TOWARDS AN AFTERNOON ROUND OF SHOWERS AND THUNDERSTORMS...STRONG
TO SEVERE...THEREFORE HAVE CONTINUED WITH ENHANCED WORDING IN THE
GRIDS. SPC ALSO HAS OUR REGION IN SLIGHT RISK ARE FOR TODAY.
ANOTHER POINT ABOUT MORNING CONVECTION IS THAT IF STORMS ARE
MAINTAINING DURING THE EARLY MORNING HOURS WITHOUT THE HELP OF
DAYTIME HEATING...THERE`S PROBABLY SOME DECENT INSTABILITY AND
FORCING MECHANISMS IN PLACE. MODELS CONTINUE TO SHOW A LOT OF CAPE
OVER THE REGION...AND TODAY LOOKS LIKE OUR DEWPOINTS ARE ACTUALLY
HIGH ENOUGH TO SUPPORT THIS...UNLIKE YESTERDAY. FEEL FAIRLY
CONFIDENT THAT THERE WILL BE STORMS AROUND THIS AFTERNOON INTO THE
EVENING HOURS...BUT TIMING IS TOUGH TO ZERO IN ON AT THIS TIME.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH TUESDAY/...
AS OF 511 AM EDT SUNDAY...STORMS CONTINUE TONIGHT AHEAD OF THE
COLD FRONT WHERE SHEAR WILL INCREASE. HIGH PWATS IN PLACE AND
PIECE OF EML PASSING SOUTH OF OUR AREA. FEEL THE MAIN THREAT WILL
BE STRONG WINDS AND HEAVY RAIN. BTV4 SHOWS A LINE OF STORMS
CROSSING OUR FORECAST AREA FROM NORTHWEST TO SOUTHEAST FROM
00-06Z. STORMS SHOULD DIE DOWN FOLLOWING FRONTAL PASSAGE
TONIGHT...AND MONDAY WILL MAINLY BE DRY BUT STILL WARM AS A WEAK
RIDGE OF HIGH PRESSURE BUILDS OVER THE AREA. MONDAY NIGHT WILL
ALSO FEATURE DRY WEATHER...THEN TUESDAY ANOTHER STRONGER COLD
FRONT WILL CROSS OUR FORECAST AREA BRINGING YET MORE SHOWERS AND
THUNDERSTORMS TO THE NORTH COUNTRY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 500 AM EDT SUNDAY...THERE WILL BE A CHANCE OF SHOWERS EACH
DAY THROUGH THE EXTENDED PERIOD...ALTHOUGH MUCH OF THE TIME WILL
BE DRY. TEMPERATURES WILL AVERAGE SEVERAL DEGREES BELOW NORMAL
DURING THE PERIOD.
SHOWERS TAPER OFF AND COME AN TUESDAY EVENING AS COLD FRONT
PUSHES FURTHER SOUTHEAST OF THE AREA AND SHORTWAVE DEPARTS. DURING
WEDNESDAY...ANOTHER DISTURBANCE IN THE FLOW ALOFT COMBINED WITH
INSTABILITY GENERATED FROM DAYTIME HEATING WILL RESULT IN CHANCE
OF A FEW AFTERNOON SHOWERS. MORE OF THE SAME EXPECTED FOR THURSDAY
AND FRIDAY AS LARGE UPPER LOW DRIFTS SOUTHEAST ACROSS QUEBEC.
EXPECT VARIABLE CLOUDS WITH CHANCE FEW SHOWERS EACH DAY...WITH
BEST CHANCE BEING DURING THE AFTERNOON HOURS DURING PEAK HEATING.
UPPER LOW FINALLY PULLS AWAY NEXT WEEKEND BUT WE REMAIN IN
NORTHWEST FLOW...SO CONTINUED CHANCE FEW SHOWERS.
MAX TEMPERATURES WILL BE MOSTLY IN THE 70S WEDNESDAY THROUGH
SATURDAY WITH OVERNIGHT LOWS MAINLY IN THE 50S.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
THROUGH 12Z MONDAY...A VARIETY OF FLIGHT CATEGORIES EARLY THIS
MORNING WITH SOME AREAS OF LOW CLOUDS AND FOG...AND ALSO A FEW
SCATTERED SHOWERS AND THUNDERSTORMS. IFR AT MPV IN FOG TILL AROUND
13Z. TSRA PSBL AT MSS AND PBG TILL AROUND 14Z. ELSEWHERE...CONDITIONS
MAINLY VFR WITH AREAS OF MVFR THIS MORNING.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE LIKELY TO
REDEVELOP ACROSS NORTHERN NEW YORK AND VERMONT BETWEEN 16-19Z.
ATTM ONLY VCSH IN TAF DUE TO TIMING/COVERAGE UNCERTAINTIES.
ACTIVITY DIMINISHES FROM WEST TO EAST BETWEEN 01Z AND 05Z
FOLLOWED BY PARTLY CLOUDY SKIES AND VFR CONDITIONS. COULD BE SOME
PATCHY IFR IN FOG AND LOW CLOUDS OVERNIGHT...WITH BEST CHANCE OF
OCCURRENCE AT MPV/SLK.
WINDS SOUTH TO SOUTHWEST 8 TO 12 KNOTS WITH SOME GUSTS 15-20
KNOTS TODAY.
OUTLOOK 12Z MONDAY THROUGH THURSDAY...
12Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL MPV/SLK.
12Z TUE - 00Z FRI...MAINLY VFR. CHANCE AFTERNOON SHOWERS EACH DAY
WITH BRIEF PERIODS OF MVFR. CHANCE THUNDERSTORMS TUESDAY PM.
&&
.MARINE...
SHOWERS WITH EMBEDDED THUNDERSTORMS ARE CURRENTLY MOVING ACROSS
THE CHAMPLAIN VALLEY. A LAKE THUNDERSTORM ADVISORY IS IN EFFECT
THROUGH THE MORNING AS THE SHOWERS AND SCATTERED THUNDERSTORMS
IMPACT THE LAKE AREA. WINDS AND WAVES MAY BE LOCALLY HIGHER IN THE
VICINITY OF THUNDERSTORMS.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...DEAL
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...RJS
MARINE...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
752 AM EDT SUN JUL 19 2015
.SYNOPSIS...
MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY OUT AHEAD OF
APPROACHING COLD FRONT WHICH WILL CROSS THE REGION OVERNIGHT. SOME
STORMS MAY BE STRONG. WEAK HIGH PRESSURE WILL BUILD OVER THE
REGION ON MONDAY AHEAD OF ANOTHER APPROACHING COLD FRONT ON
TUESDAY WHICH WILL BRING MORE SHOWERS AND THUNDERSTORMS. COOLER
WEATHER WITH SCATTERED SHOWERS WILL FOLLOW FOR THE REST OF THE
WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 740 AM EDT SUNDAY...FIRST ROUND OF STORMS MOVING INTO
NORTHERN NEW YORK AND VERMONT CURRENTLY. HRRR IS THE ONLY
MESOSCALE MODEL SEEMS TO HAVE A CLUE ABOUT IT. STILL THINK THERE
WILL BE A SECOND ROUND OF STRONGER STORMS LATER THIS AFTERNOON.
PREVIOUS DISCUSSION FOLLOWS.
EARLY MORNING FOG WILL LIFT THIS MORNING SHORTLY AFTER SUNRISE AS
DAYTIME HEATING BEGINS. A COUPLE ROUNDS OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED TODAY. FIRST ROUND OF SHOWERS IS
ASSOCIATED WITH ONGOING CONVECTION DURING THE OVERNIGHT WHICH IS
OCCURRING IN ONTARIO AND QUEBEC. EXPECT THESE SHOWERS TO MOVE
ACROSS OUR AREA DURING THE EARLY MORNING HOURS...AND THEN A SECOND
ROUND OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AHEAD OF COLD
FRONT. AN UPPER LEVEL TROF WILL MOVE EASTWARD FROM THE GREAT LAKES
REGION. SURFACE DEWPOINTS ARE VERY HIGH TODAY...UPPER 60S TO LOWER
70S...AND THIS WILL RESULT IN MODERATE TO STRONG INSTABILITY IN
THE AFTERNOON. FORECAST SOUNDINGS ARE INDICATING UP TO 35 KTS OF
DEEP LAYER SHEAR. VERY MOIST AIR IS ALSO IN PLACE AS IS EVIDENT
FROM PWATS AROUND 1.75 INCHES IN THE NAM PROFILES. DURING THE LATE
AFTERNOON A PIECE OF EML DRIFTS JUST SOUTH OF OUR FORECAST
AREA...AND CROSSING NEW ENGLAND OVERNIGHT.
UNFORTUNATELY NOT MUCH AGREEMENT BETWEEN MESOSCALE MODELS FOR
TODAY...BUT HRRR SHOWS AREA OF SHOWERS AND THUNDERSTORMS CURRENTLY
OVER THE BORDER OF ONTARIO AND QUEBEC WILL DROP SOUTHEASTWARD
ACROSS OUR NORTHERN ZONES DURING THE MORNING HOURS. A LITTLE
CONCERNED THAT HAVING MORNING CONVECTION AROUND COULD LIMIT
AFTERNOON CONVECTION IF THERE IS NO CLEARING FOLLOWING FIRST ROUND
OF CONVECTION. BUT...LOOKS LIKE THERE ARE ENOUGH FACTORS POINTING
TOWARDS AN AFTERNOON ROUND OF SHOWERS AND THUNDERSTORMS...STRONG
TO SEVERE...THEREFORE HAVE CONTINUED WITH ENHANCED WORDING IN THE
GRIDS. SPC ALSO HAS OUR REGION IN SLIGHT RISK ARE FOR TODAY.
ANOTHER POINT ABOUT MORNING CONVECTION IS THAT IF STORMS ARE
MAINTAINING DURING THE EARLY MORNING HOURS WITHOUT THE HELP OF
DAYTIME HEATING...THERE`S PROBABLY SOME DECENT INSTABILITY AND
FORCING MECHANISMS IN PLACE. MODELS CONTINUE TO SHOW A LOT OF CAPE
OVER THE REGION...AND TODAY LOOKS LIKE OUR DEWPOINTS ARE ACTUALLY
HIGH ENOUGH TO SUPPORT THIS...UNLIKE YESTERDAY. FEEL FAIRLY
CONFIDENT THAT THERE WILL BE STORMS AROUND THIS AFTERNOON INTO THE
EVENING HOURS...BUT TIMING IS TOUGH TO ZERO IN ON AT THIS TIME.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH TUESDAY/...
AS OF 511 AM EDT SUNDAY...STORMS CONTINUE TONIGHT AHEAD OF THE
COLD FRONT WHERE SHEAR WILL INCREASE. HIGH PWATS IN PLACE AND
PIECE OF EML PASSING SOUTH OF OUR AREA. FEEL THE MAIN THREAT WILL
BE STRONG WINDS AND HEAVY RAIN. BTV4 SHOWS A LINE OF STORMS
CROSSING OUR FORECAST AREA FROM NORTHWEST TO SOUTHEAST FROM
00-06Z. STORMS SHOULD DIE DOWN FOLLOWING FRONTAL PASSAGE
TONIGHT...AND MONDAY WILL MAINLY BE DRY BUT STILL WARM AS A WEAK
RIDGE OF HIGH PRESSURE BUILDS OVER THE AREA. MONDAY NIGHT WILL
ALSO FEATURE DRY WEATHER...THEN TUESDAY ANOTHER STRONGER COLD
FRONT WILL CROSS OUR FORECAST AREA BRINGING YET MORE SHOWERS AND
THUNDERSTORMS TO THE NORTH COUNTRY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 500 AM EDT SUNDAY...THERE WILL BE A CHANCE OF SHOWERS EACH
DAY THROUGH THE EXTENDED PERIOD...ALTHOUGH MUCH OF THE TIME WILL
BE DRY. TEMPERATURES WILL AVERAGE SEVERAL DEGREES BELOW NORMAL
DURING THE PERIOD.
SHOWERS TAPER OFF AND COME AN TUESDAY EVENING AS COLD FRONT
PUSHES FURTHER SOUTHEAST OF THE AREA AND SHORTWAVE DEPARTS. DURING
WEDNESDAY...ANOTHER DISTURBANCE IN THE FLOW ALOFT COMBINED WITH
INSTABILITY GENERATED FROM DAYTIME HEATING WILL RESULT IN CHANCE
OF A FEW AFTERNOON SHOWERS. MORE OF THE SAME EXPECTED FOR THURSDAY
AND FRIDAY AS LARGE UPPER LOW DRIFTS SOUTHEAST ACROSS QUEBEC.
EXPECT VARIABLE CLOUDS WITH CHANCE FEW SHOWERS EACH DAY...WITH
BEST CHANCE BEING DURING THE AFTERNOON HOURS DURING PEAK HEATING.
UPPER LOW FINALLY PULLS AWAY NEXT WEEKEND BUT WE REMAIN IN
NORTHWEST FLOW...SO CONTINUED CHANCE FEW SHOWERS.
MAX TEMPERATURES WILL BE MOSTLY IN THE 70S WEDNESDAY THROUGH
SATURDAY WITH OVERNIGHT LOWS MAINLY IN THE 50S.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THROUGH 12Z MONDAY...A VARIETY OF FLIGHT CATEGORIES EARLY THIS
MORNING WITH SOME AREAS OF LOW CLOUDS AND FOG...AND ALSO A FEW
SCATTERED SHOWERS AND THUNDERSTORMS. IFR AT MPV IN FOG TILL AROUND
13Z. TSRA PSBL AT MSS AND PBG TILL AROUND 14Z. ELSEWHERE...CONDITIONS
MAINLY VFR WITH AREAS OF MVFR THIS MORNING.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE LIKELY TO
REDEVELOP ACROSS NORTHERN NEW YORK AND VERMONT BETWEEN 16-19Z.
ATTM ONLY VCSH IN TAF DUE TO TIMING/COVERAGE UNCERTAINTIES.
ACTIVITY DIMINISHES FROM WEST TO EAST BETWEEN 01Z AND 05Z
FOLLOWED BY PARTLY CLOUDY SKIES AND VFR CONDITIONS. COULD BE SOME
PATCHY IFR IN FOG AND LOW CLOUDS OVERNIGHT...WITH BEST CHANCE OF
OCCURRENCE AT MPV/SLK.
WINDS SOUTH TO SOUTHWEST 8 TO 12 KNOTS WITH SOME GUSTS 15-20
KNOTS TODAY.
OUTLOOK 12Z MONDAY THROUGH THURSDAY...
12Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL MPV/SLK.
12Z TUE - 00Z FRI...MAINLY VFR. CHANCE AFTERNOON SHOWERS EACH DAY
WITH BRIEF PERIODS OF MVFR. CHANCE THUNDERSTORMS TUESDAY PM.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...NEILES
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
744 AM EDT SUN JUL 19 2015
.SYNOPSIS...
MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY OUT AHEAD OF
APPROACHING COLD FRONT WHICH WILL CROSS THE REGION OVERNIGHT. SOME
STORMS MAY BE STRONG. WEAK HIGH PRESSURE WILL BUILD OVER THE
REGION ON MONDAY AHEAD OF ANOTHER APPROACHING COLD FRONT ON
TUESDAY WHICH WILL BRING MORE SHOWERS AND THUNDERSTORMS. COOLER
WEATHER WITH SCATTERED SHOWERS WILL FOLLOW FOR THE REST OF THE
WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AS OF 740 AM EDT SUNDAY...FIRST ROUND OF STORMS MOVING INTO
NORTHERN NEW YORK AND VERMONT CURRENTLY. HRRR IS THE ONLY
MESOSCALE MODEL SEEMS TO HAVE A CLUE ABOUT IT. STILL THINK THERE
WILL BE A SECOND ROUND OF STRONGER STORMS LATER THIS AFTERNOON.
PREVIOUS DISCUSSION FOLLOWS.
EARLY MORNING FOG WILL LIFT THIS MORNING SHORTLY AFTER SUNRISE AS
DAYTIME HEATING BEGINS. A COUPLE ROUNDS OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED TODAY. FIRST ROUND OF SHOWERS IS
ASSOCIATED WITH ONGOING CONVECTION DURING THE OVERNIGHT WHICH IS
OCCURRING IN ONTARIO AND QUEBEC. EXPECT THESE SHOWERS TO MOVE
ACROSS OUR AREA DURING THE EARLY MORNING HOURS...AND THEN A SECOND
ROUND OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AHEAD OF COLD
FRONT. AN UPPER LEVEL TROF WILL MOVE EASTWARD FROM THE GREAT LAKES
REGION. SURFACE DEWPOINTS ARE VERY HIGH TODAY...UPPER 60S TO LOWER
70S...AND THIS WILL RESULT IN MODERATE TO STRONG INSTABILITY IN
THE AFTERNOON. FORECAST SOUNDINGS ARE INDICATING UP TO 35 KTS OF
DEEP LAYER SHEAR. VERY MOIST AIR IS ALSO IN PLACE AS IS EVIDENT
FROM PWATS AROUND 1.75 INCHES IN THE NAM PROFILES. DURING THE LATE
AFTERNOON A PIECE OF EML DRIFTS JUST SOUTH OF OUR FORECAST
AREA...AND CROSSING NEW ENGLAND OVERNIGHT.
UNFORTUNATELY NOT MUCH AGREEMENT BETWEEN MESOSCALE MODELS FOR
TODAY...BUT HRRR SHOWS AREA OF SHOWERS AND THUNDERSTORMS CURRENTLY
OVER THE BORDER OF ONTARIO AND QUEBEC WILL DROP SOUTHEASTWARD
ACROSS OUR NORTHERN ZONES DURING THE MORNING HOURS. A LITTLE
CONCERNED THAT HAVING MORNING CONVECTION AROUND COULD LIMIT
AFTERNOON CONVECTION IF THERE IS NO CLEARING FOLLOWING FIRST ROUND
OF CONVECTION. BUT...LOOKS LIKE THERE ARE ENOUGH FACTORS POINTING
TOWARDS AN AFTERNOON ROUND OF SHOWERS AND THUNDERSTORMS...STRONG
TO SEVERE...THEREFORE HAVE CONTINUED WITH ENHANCED WORDING IN THE
GRIDS. SPC ALSO HAS OUR REGION IN SLIGHT RISK ARE FOR TODAY.
ANOTHER POINT ABOUT MORNING CONVECTION IS THAT IF STORMS ARE
MAINTAINING DURING THE EARLY MORNING HOURS WITHOUT THE HELP OF
DAYTIME HEATING...THERE`S PROBABLY SOME DECENT INSTABILITY AND
FORCING MECHANISMS IN PLACE. MODELS CONTINUE TO SHOW A LOT OF CAPE
OVER THE REGION...AND TODAY LOOKS LIKE OUR DEWPOINTS ARE ACTUALLY
HIGH ENOUGH TO SUPPORT THIS...UNLIKE YESTERDAY. FEEL FAIRLY
CONFIDENT THAT THERE WILL BE STORMS AROUND THIS AFTERNOON INTO THE
EVENING HOURS...BUT TIMING IS TOUGH TO ZERO IN ON AT THIS TIME.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH TUESDAY/...
AS OF 511 AM EDT SUNDAY...STORMS CONTINUE TONIGHT AHEAD OF THE
COLD FRONT WHERE SHEAR WILL INCREASE. HIGH PWATS IN PLACE AND
PIECE OF EML PASSING SOUTH OF OUR AREA. FEEL THE MAIN THREAT WILL
BE STRONG WINDS AND HEAVY RAIN. BTV4 SHOWS A LINE OF STORMS
CROSSING OUR FORECAST AREA FROM NORTHWEST TO SOUTHEAST FROM
00-06Z. STORMS SHOULD DIE DOWN FOLLOWING FRONTAL PASSAGE
TONIGHT...AND MONDAY WILL MAINLY BE DRY BUT STILL WARM AS A WEAK
RIDGE OF HIGH PRESSURE BUILDS OVER THE AREA. MONDAY NIGHT WILL
ALSO FEATURE DRY WEATHER...THEN TUESDAY ANOTHER STRONGER COLD
FRONT WILL CROSS OUR FORECAST AREA BRINGING YET MORE SHOWERS AND
THUNDERSTORMS TO THE NORTH COUNTRY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 500 AM EDT SUNDAY...THERE WILL BE A CHANCE OF SHOWERS EACH
DAY THROUGH THE EXTENDED PERIOD...ALTHOUGH MUCH OF THE TIME WILL
BE DRY. TEMPERATURES WILL AVERAGE SEVERAL DEGREES BELOW NORMAL
DURING THE PERIOD.
SHOWERS TAPER OFF AND COME AN TUESDAY EVENING AS COLD FRONT
PUSHES FURTHER SOUTHEAST OF THE AREA AND SHORTWAVE DEPARTS. DURING
WEDNESDAY...ANOTHER DISTURBANCE IN THE FLOW ALOFT COMBINED WITH
INSTABILITY GENERATED FROM DAYTIME HEATING WILL RESULT IN CHANCE
OF A FEW AFTERNOON SHOWERS. MORE OF THE SAME EXPECTED FOR THURSDAY
AND FRIDAY AS LARGE UPPER LOW DRIFTS SOUTHEAST ACROSS QUEBEC.
EXPECT VARIABLE CLOUDS WITH CHANCE FEW SHOWERS EACH DAY...WITH
BEST CHANCE BEING DURING THE AFTERNOON HOURS DURING PEAK HEATING.
UPPER LOW FINALLY PULLS AWAY NEXT WEEKEND BUT WE REMAIN IN
NORTHWEST FLOW...SO CONTINUED CHANCE FEW SHOWERS.
MAX TEMPERATURES WILL BE MOSTLY IN THE 70S WEDNESDAY THROUGH
SATURDAY WITH OVERNIGHT LOWS MAINLY IN THE 50S.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THROUGH 06Z MONDAY...A VARIETY OF FLIGHT CATEGORIES OVERNIGHT
WITH SOME AREAS OF LOW CLOUDS AND FOG...AND ALSO A FEW SCATTERED
SHOWERS AND PERHAPS EVEN A THUNDERSTORM. IFR MOST LIKELY AT MPV
AND POSSIBLY SLK IN FOG. ELSEWHERE...CONDITIONS MAINLY VFR/MVFR
WITH BRIEF IFR POSSIBLE IN ANY SHOWERS.
VFR CONDITIONS RETURN EVERYWHERE AFTER 12-14Z SUNDAY BUT SCT TO
NUMEROUS SHOWERS AND THUNDERSTORMS LIKELY TO DEVELOP ACROSS
NORTHERN NEW YORK AND VERMONT BETWEEN 16-18Z. ATTM ONLY VCSH IN
TAF DUE TO TIMING/COVERAGE UNCERTAINTIES.
OUTLOOK 06Z MONDAY THROUGH THURSDAY...
06Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL
MPV/SLK.
12Z TUE - 00Z FRI...MAINLY VFR. CHANCE AFTERNOON SHOWERS EACH DAY
WITH BRIEF PERIODS OF MVFR. CHANCE THUNDERSTORMS TUESDAY PM.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...NEILES
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
514 AM EDT SUN JUL 19 2015
.SYNOPSIS...
MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY OUT AHEAD OF
APPROACHING COLD FRONT WHICH WILL CROSS THE REGION OVERNIGHT. SOME
STORMS MAY BE STRONG. WEAK HIGH PRESSURE WILL BUILD OVER THE
REGION ON MONDAY AHEAD OF ANOTHER APPROACHING COLD FRONT ON
TUESDAY WHICH WILL BRING MORE SHOWERS AND THUNDERSTORMS. COOLER
WEATHER WITH SCATTERED SHOWERS WILL FOLLOW FOR THE REST OF THE
WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
EARLY MORNING FOG WILL LIFT THIS MORNING SHORTLY AFTER SUNRISE AS
DAYTIME HEATING BEGINS. A COUPLE ROUNDS OF SHOWERS AND
THUNDERSTORMS ARE EXPECTED TODAY. FIRST ROUND OF SHOWERS IS
ASSOCIATED WITH ONGOING CONVECTION DURING THE OVERNIGHT WHICH IS
OCCURRING IN ONTARIO AND QUEBEC. EXPECT THESE SHOWERS TO MOVE
ACROSS OUR AREA DURING THE EARLY MORNING HOURS...AND THEN A SECOND
ROUND OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AHEAD OF COLD
FRONT. AN UPPER LEVEL TROF WILL MOVE EASTWARD FROM THE GREAT LAKES
REGION. SURFACE DEWPOINTS ARE VERY HIGH TODAY...UPPER 60S TO LOWER
70S...AND THIS WILL RESULT IN MODERATE TO STRONG INSTABILITY IN
THE AFTERNOON. FORECAST SOUNDINGS ARE INDICATING UP TO 35 KTS OF
DEEP LAYER SHEAR. VERY MOIST AIR IS ALSO IN PLACE AS IS EVIDENT
FROM PWATS AROUND 1.75 INCHES IN THE NAM PROFILES. DURING THE LATE
AFTERNOON A PIECE OF EML DRIFTS JUST SOUTH OF OUR FORECAST
AREA...AND CROSSING NEW ENGLAND OVERNIGHT.
UNFORTUNATELY NOT MUCH AGREEMENT BETWEEN MESOSCALE MODELS FOR
TODAY...BUT HRRR SHOWS AREA OF SHOWERS AND THUNDERSTORMS CURRENTLY
OVER THE BORDER OF ONTARIO AND QUEBEC WILL DROP SOUTHEASTWARD
ACROSS OUR NORTHERN ZONES DURING THE MORNING HOURS. A LITTLE
CONCERNED THAT HAVING MORNING CONVECTION AROUND COULD LIMIT
AFTERNOON CONVECTION IF THERE IS NO CLEARING FOLLOWING FIRST ROUND
OF CONVECTION. BUT...LOOKS LIKE THERE ARE ENOUGH FACTORS POINTING
TOWARDS AN AFTERNOON ROUND OF SHOWERS AND THUNDERSTORMS...STRONG
TO SEVERE...THEREFORE HAVE CONTINUED WITH ENHANCED WORDING IN THE
GRIDS. SPC ALSO HAS OUR REGION IN SLIGHT RISK ARE FOR TODAY.
ANOTHER POINT ABOUT MORNING CONVECTION IS THAT IF STORMS ARE
MAINTAINING DURING THE EARLY MORNING HOURS WITHOUT THE HELP OF
DAYTIME HEATING...THERE`S PROBABLY SOME DECENT INSTABILITY AND
FORCING MECHANISMS IN PLACE. MODELS CONTINUE TO SHOW A LOT OF CAPE
OVER THE REGION...AND TODAY LOOKS LIKE OUR DEWPOINTS ARE ACTUALLY
HIGH ENOUGH TO SUPPORT THIS...UNLIKE YESTERDAY. FEEL FAIRLY
CONFIDENT THAT THERE WILL BE STORMS AROUND THIS AFTERNOON INTO THE
EVENING HOURS...BUT TIMING IS TOUGH TO ZERO IN ON AT THIS TIME.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH TUESDAY/...
AS OF 511 AM EDT SUNDAY...STORMS CONTINUE TONIGHT AHEAD OF THE
COLD FRONT WHERE SHEAR WILL INCREASE. HIGH PWATS IN PLACE AND
PIECE OF EML PASSING SOUTH OF OUR AREA. FEEL THE MAIN THREAT WILL
BE STRONG WINDS AND HEAVY RAIN. BTV4 SHOWS A LINE OF STORMS
CROSSING OUR FORECAST AREA FROM NORTHWEST TO SOUTHEAST FROM
00-06Z. STORMS SHOULD DIE DOWN FOLLOWING FRONTAL PASSAGE
TONIGHT...AND MONDAY WILL MAINLY BE DRY BUT STILL WARM AS A WEAK
RIDGE OF HIGH PRESSURE BUILDS OVER THE AREA. MONDAY NIGHT WILL
ALSO FEATURE DRY WEATHER...THEN TUESDAY ANOTHER STRONGER COLD
FRONT WILL CROSS OUR FORECAST AREA BRINGING YET MORE SHOWERS AND
THUNDERSTORMS TO THE NORTH COUNTRY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 500 AM EDT SUNDAY...THERE WILL BE A CHANCE OF SHOWERS EACH
DAY THROUGH THE EXTENDED PERIOD...ALTHOUGH MUCH OF THE TIME WILL
BE DRY. TEMPERATURES WILL AVERAGE SEVERAL DEGREES BELOW NORMAL
DURING THE PERIOD.
SHOWERS TAPER OFF AND COME AN TUESDAY EVENING AS COLD FRONT
PUSHES FURTHER SOUTHEAST OF THE AREA AND SHORTWAVE DEPARTS. DURING
WEDNESDAY...ANOTHER DISTURBANCE IN THE FLOW ALOFT COMBINED WITH
INSTABILITY GENERATED FROM DAYTIME HEATING WILL RESULT IN CHANCE
OF A FEW AFTERNOON SHOWERS. MORE OF THE SAME EXPECTED FOR THURSDAY
AND FRIDAY AS LARGE UPPER LOW DRIFTS SOUTHEAST ACROSS QUEBEC.
EXPECT VARIABLE CLOUDS WITH CHANCE FEW SHOWERS EACH DAY...WITH
BEST CHANCE BEING DURING THE AFTERNOON HOURS DURING PEAK HEATING.
UPPER LOW FINALLY PULLS AWAY NEXT WEEKEND BUT WE REMAIN IN
NORTHWEST FLOW...SO CONTINUED CHANCE FEW SHOWERS.
MAX TEMPERATURES WILL BE MOSTLY IN THE 70S WEDNESDAY THROUGH
SATURDAY WITH OVERNIGHT LOWS MAINLY IN THE 50S.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
THROUGH 06Z MONDAY...A VARIETY OF FLIGHT CATEGORIES OVERNIGHT
WITH SOME AREAS OF LOW CLOUDS AND FOG...AND ALSO A FEW SCATTERED
SHOWERS AND PERHAPS EVEN A THUNDERSTORM. IFR MOST LIKELY AT MPV
AND POSSIBLY SLK IN FOG. ELSEWHERE...CONDITIONS MAINLY VFR/MVFR
WITH BRIEF IFR POSSIBLE IN ANY SHOWERS.
VFR CONDITIONS RETURN EVERYWHERE AFTER 12-14Z SUNDAY BUT SCT TO
NUMEROUS SHOWERS AND THUNDERSTORMS LIKELY TO DEVELOP ACROSS
NORTHERN NEW YORK AND VERMONT BETWEEN 16-18Z. ATTM ONLY VCSH IN
TAF DUE TO TIMING/COVERAGE UNCERTAINTIES.
OUTLOOK 06Z MONDAY THROUGH THURSDAY...
06Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL
MPV/SLK.
12Z TUE - 00Z FRI...MAINLY VFR. CHANCE AFTERNOON SHOWERS EACH DAY
WITH BRIEF PERIODS OF MVFR. CHANCE THUNDERSTORMS TUESDAY PM.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...NEILES
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
501 AM EDT SUN JUL 19 2015
.SYNOPSIS...
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
WEEKEND. SOME STORMS MAY BE STRONG WITH GUSTY WINDS AND HEAVY
RAINFALL. BEST CHANCE FOR HEAVY RAIN WILL BE SUNDAY NIGHT AHEAD OF
A COLD FRONT WHICH WILL CROSS THE AREA LATE SUNDAY NIGHT INTO EARLY
MONDAY MORNING. WARMER THAN NORMAL TEMPERATURES THIS WEEKEND WILL
TREND BACK TOWARDS SEASONAL NORMALS DURING THE WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 101 AM EDT SUNDAY...THOUGH GENERALLY SMALL, I`VE MADE
SEVERAL CHANGES TO THE OVERNIGHT FORECAST WITH THIS UPDATE.
EARLIER SURFACE CONFLUENCE LINE WHICH HELPED TRIGGER SCATTERED
CONVECTION IN A MODERATELY-UNSTABLE AIRMASS HAS SINCE SHIFTED
INTO NEW HAMPSHIRE, AND I`VE BACKED OFF ON SHOWERS/THUNDER
THROUGH MIDNIGHT. WATER VAPOR IMAGERY AND RAP-BASED HEIGHT FIELD
PROGS INFER MID-LEVEL SHORTWAVE RIDGING NOW SPREADING ACROSS THE
NORTH COUNTRY. THAT SHOULD KEEP MUCH OF THE REGION DRY THROUGH
PART OF THE OVERNIGHT. HOWEVER, RIDGING WILL BE SHORT-LIVED AS
LEADING EDGE OF MID-LEVEL HEIGHT FALLS BEGINS TO ENTER ST.
LAWRENCE VALLEY. LATEST BTV-6 AND HRRR OUTPUT SHOW RE-DEVELOPMENT
OF SHOWERS ACROSS THIS AREA AFTER 08Z, WHICH MAY BE A
SIGNIFICANTLY WEAKER PORTION OF UPSTREAM MCS OVER THE SOUTHERN
GREAT LAKES. SO EXPECT CLOUDS TO INCREASE WITH SLIGHT CHANCE POPS
RE-INTRODUCED FOR NORTHERN NEW YORK AREAS AFTER MIDNIGHT. WITH HOW
HUMID IT IS OUTSIDE, I COULDN`T RULE OUT A RUMBLE OF THUNDER IF
ACTIVITY DEVELOPS AS PROGGED.
SPECIFIC TO THE DEWPOINT/HUMIDITY LEVELS...TEMPERATURE/DEWPOINT
SPREADS ACROSS THE NORTH COUNTRY ARE ALREADY PRETTY SMALL (WITHIN
2-4 DEGREES OF EACH OTHER). ADDITIONALLY, WITH THE POTENTIAL FOR
WINDS TO DECOUPLE, I`VE ADDED PATCHY FOG EVERYWHERE. THERE
ALREADY ARE A FEW SITES (FSO, CDA AND MVL) REPORTING EITHER FOG OR
MIST.
WITH NO CHANGE IN AIR MASS EXPECTED, THIS WILL BE A MUGGY NIGHT.
TEMPS WILL FALL VERY SLOWLY INTO THE MID 60S TO LOW 70S, CLOSE TO
OR EQUAL TO DEWPOINTS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH TUESDAY/...
AS OF 338 PM EDT SATURDAY...THE LATEST SUITE OF GUIDANCE HAS
TRENDED TO A MUCH MORE ACTIVE DAY LATE ON SUNDAY ESPECIALLY
HEADING INTO THE EVENING AND THE OVERNIGHT HOURS. SUNDAY WILL
START OFF AS A WARM MUGGY MORNING AND WILL BE THE WARMEST DAY OF
THE FORECAST PERIOD WITH SOUTHERLY SURFACE WINDS CONTINUING TO
BRING WARM AIR INTO THE REGION. EXPECT MAX TEMPS TOMORROW TO WARM
INTO THE MID 80S IN THE VALLEYS WITH SURFACE DEWPOINTS QUICKLY
RISING TO NEARLY 70 EARLY IN THE MORNING. THE COMBINATION OF HIGH
MOISTURE AND WARM TEMPS WILL RESULT IN AN UNSTABLE ATMOSPHERE WITH
PLENTY OF INSTABILITY. CURRENT FORECAST CAPE WILL RISE TO
2000-3000 J/KG BY MID AFTERNOON WITH IMPRESSION ELEVATED
INSTABILITY ALSO HOWEVER FORECAST SOUNDINGS DO SHOW A DECENT CAP
THROUGH ABOUT MID AFTERNOON. SO WIDESPREAD CONVECTION WILL BE
LIMITED THROUGH THE AFTERNOON BEFORE WE FINALLY ERODE THE CAP.
ONCE THE CAP ERODES HOWEVER IN THE LATE AFTERNOON/EVENING WE WILL
SEE OUR BEST CHANCE FOR SHOWERS WITH THE POTENTIAL FOR STRONG TO
SEVERE THUNDERSTORMS PRODUCING STRONG GUSTY WINDS AND LOCALLY
HEAVY RAINFALL.
THE FORCING WILL COME IN THE SHAPE OF AN ADVANCING COLD FRONT AND
AHEAD OF THE COLD FRONT THE ATMOSPHERE DYNAMICS ARE SHAPING UP TO
BE A MUCH BETTER STRONG TO SEVERE CHANCE THAN SATURDAY. JUST AHEAD
OF THE FRONT WILL SEE A RAPID INCREASE IN 0-6KM BULK SHEAR TO
40-45KT WITH MID LEVEL LAPSE RATES IMPROVING TO 7-7.5 DEG C/KM.
WITH PW ALREADY 1.5 STANDARDIZE ANOMALIES ABOVE NORMAL NEARING THE
2.0" INCH RANGE EXPECT MODERATE TO HEAVY RAIN RATES WITH THE
SHOWERS THAT DEVELOP AHEAD OF THE COLD FRONT. FLASH FLOODING IS A
CONCERN BUT WITH THE LATEST MODEL TRENDS THE HIGHEST TOTAL QPF`S
ARE A BIT FURTHER TO THE WEST AND SOUTH OF THE AREA SO I OPTED TO
HOLD OFF ON A FLASH FLOOD WATCH WITH THIS ISSUANCE. MODEL GUIDANCE
CONTINUES TO SHOW A WELL DEVELOPED EML MOVING IN JUST AHEAD OF THE
FRONT SO STRONG WINDS WITH HEAVY RAINFALL WILL BE THE MAIN THREATS
WITH THIS SYSTEM.
AFTER THE FRONT CLEARS THE AREA, AND THE MODELS HAVE TRENDED
FASTER WITH THIS SYSTEM, EXPECT MONDAY TO BE QUIET AND SLIGHTLY
COOLER UNDER HIGH PRESSURE MOVING IN BEHIND THE FRONT. NORTHWEST
FLOW WILL BRING DRIER AIR INTO THE REGION WHICH SHOULD SERVE TO
CLEAR THE AREA OUT ALLOWING TEMPS TO STILL BE ABLE TO WARM TO THE
LOW 80`S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 500 AM EDT SUNDAY...THERE WILL BE A CHANCE OF SHOWERS EACH
DAY THROUGH THE EXTENDED PERIOD...ALTHOUGH MUCH OF THE TIME WILL
BE DRY. TEMPERATURES WILL AVERAGE SEVERAL DEGREES BELOW NORMAL
DURING THE PERIOD.
SHOWERS TAPER OFF AND COME AN TUESDAY EVENING AS COLD FRONT PUSHES
FURTHER SOUTHEAST OF THE AREA AND SHORTWAVE DEPARTS. DURING
WEDNESDAY...ANOTHER DISTURBANCE IN THE FLOW ALOFT COMBINED WITH
INSTABILITY GENERATED FROM DAYTIME HEATING WILL RESULT IN CHANCE OF
A FEW AFTERNOON SHOWERS. MORE OF THE SAME EXPECTED FOR THURSDAY AND
FRIDAY AS LARGE UPPER LOW DRIFTS SOUTHEAST ACROSS QUEBEC. EXPECT
VARIABLE CLOUDS WITH CHANCE FEW SHOWERS EACH DAY...WITH BEST CHANCE
BEING DURING THE AFTERNOON HOURS DURING PEAK HEATING. UPPER LOW
FINALLY PULLS AWAY NEXT WEEKEND BUT WE REMAIN IN NORTHWEST FLOW...SO
CONTINUED CHANCE FEW SHOWERS.
MAX TEMPERATURES WILL BE MOSTLY IN THE 70S WEDNESDAY THROUGH
SATURDAY WITH OVERNIGHT LOWS MAINLY IN THE 50S.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
THROUGH 06Z MONDAY...A VARIETY OF FLIGHT CATEGORIES OVERNIGHT WITH
SOME AREAS OF LOW CLOUDS AND FOG...AND ALSO A FEW SCATTERED SHOWERS
AND PERHAPS EVEN A THUNDERSTORM. IFR MOST LIKELY AT MPV AND
POSSIBLY SLK IN FOG. ELSEWHERE...CONDITIONS MAINLY VFR/MVFR WITH
BRIEF IFR POSSIBLE IN ANY SHOWERS.
VFR CONDITIONS RETURN EVERYWHERE AFTER 12-14Z SUNDAY BUT SCT TO
NUMEROUS SHOWERS AND THUNDERSTORMS LIKELY TO DEVELOP ACROSS
NORTHERN NEW YORK AND VERMONT BETWEEN 16-18Z. ATTM ONLY VCSH IN
TAF DUE TO TIMING/COVERAGE UNCERTAINTIES.
OUTLOOK 06Z MONDAY THROUGH THURSDAY...
06Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL MPV/SLK.
12Z TUE - 00Z FRI...MAINLY VFR. CHANCE AFTERNOON SHOWERS EACH DAY
WITH BRIEF PERIODS OF MVFR. CHANCE THUNDERSTORMS TUESDAY PM.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...NEILES/LOCONTO/SLW
SHORT TERM...DEAL
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
152 AM EDT SUN JUL 19 2015
.SYNOPSIS...
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
WEEKEND. SOME STORMS MAY BE STRONG WITH GUSTY WINDS AND HEAVY
RAINFALL. BEST CHANCE FOR HEAVY RAIN WILL BE SUNDAY NIGHT AHEAD OF
A COLD FRONT WHICH WILL CROSS THE AREA LATE SUNDAY NIGHT INTO EARLY
MONDAY MORNING. WARMER THAN NORMAL TEMPERATURES THIS WEEKEND WILL
TREND BACK TOWARDS SEASONAL NORMALS DURING THE WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 101 AM EDT SUNDAY...THOUGH GENERALLY SMALL, I`VE MADE
SEVERAL CHANGES TO THE OVERNIGHT FORECAST WITH THIS UPDATE.
EARLIER SURFACE CONFLUENCE LINE WHICH HELPED TRIGGER SCATTERED
CONVECTION IN A MODERATELY-UNSTABLE AIRMASS HAS SINCE SHIFTED
INTO NEW HAMPSHIRE, AND I`VE BACKED OFF ON SHOWERS/THUNDER
THROUGH MIDNIGHT. WATER VAPOR IMAGERY AND RAP-BASED HEIGHT FIELD
PROGS INFER MID-LEVEL SHORTWAVE RIDGING NOW SPREADING ACROSS THE
NORTH COUNTRY. THAT SHOULD KEEP MUCH OF THE REGION DRY THROUGH
PART OF THE OVERNIGHT. HOWEVER, RIDGING WILL BE SHORT-LIVED AS
LEADING EDGE OF MID-LEVEL HEIGHT FALLS BEGINS TO ENTER ST.
LAWRENCE VALLEY. LATEST BTV-6 AND HRRR OUTPUT SHOW RE-DEVELOPMENT
OF SHOWERS ACROSS THIS AREA AFTER 08Z, WHICH MAY BE A
SIGNIFICANTLY WEAKER PORTION OF UPSTREAM MCS OVER THE SOUTHERN
GREAT LAKES. SO EXPECT CLOUDS TO INCREASE WITH SLIGHT CHANCE POPS
RE-INTRODUCED FOR NORTHERN NEW YORK AREAS AFTER MIDNIGHT. WITH HOW
HUMID IT IS OUTSIDE, I COULDN`T RULE OUT A RUMBLE OF THUNDER IF
ACTIVITY DEVELOPS AS PROGGED.
SPECIFIC TO THE DEWPOINT/HUMIDITY LEVELS...TEMPERATURE/DEWPOINT
SPREADS ACROSS THE NORTH COUNTRY ARE ALREADY PRETTY SMALL (WITHIN
2-4 DEGREES OF EACH OTHER). ADDITIONALLY, WITH THE POTENTIAL FOR
WINDS TO DECOUPLE, I`VE ADDED PATCHY FOG EVERYWHERE. THERE
ALREADY ARE A FEW SITES (FSO, CDA AND MVL) REPORTING EITHER FOG OR
MIST.
WITH NO CHANGE IN AIR MASS EXPECTED, THIS WILL BE A MUGGY NIGHT.
TEMPS WILL FALL VERY SLOWLY INTO THE MID 60S TO LOW 70S, CLOSE TO
OR EQUAL TO DEWPOINTS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH MONDAY NIGHT/...
AS OF 338 PM EDT SATURDAY...THE LATEST SUITE OF GUIDANCE HAS
TRENDED TO A MUCH MORE ACTIVE DAY LATE ON SUNDAY ESPECIALLY
HEADING INTO THE EVENING AND THE OVERNIGHT HOURS. SUNDAY WILL
START OFF AS A WARM MUGGY MORNING AND WILL BE THE WARMEST DAY OF
THE FORECAST PERIOD WITH SOUTHERLY SURFACE WINDS CONTINUING TO
BRING WARM AIR INTO THE REGION. EXPECT MAX TEMPS TOMORROW TO WARM
INTO THE MID 80S IN THE VALLEYS WITH SURFACE DEWPOINTS QUICKLY
RISING TO NEARLY 70 EARLY IN THE MORNING. THE COMBINATION OF HIGH
MOISTURE AND WARM TEMPS WILL RESULT IN AN UNSTABLE ATMOSPHERE WITH
PLENTY OF INSTABILITY. CURRENT FORECAST CAPE WILL RISE TO
2000-3000 J/KG BY MID AFTERNOON WITH IMPRESSION ELEVATED
INSTABILITY ALSO HOWEVER FORECAST SOUNDINGS DO SHOW A DECENT CAP
THROUGH ABOUT MID AFTERNOON. SO WIDESPREAD CONVECTION WILL BE
LIMITED THROUGH THE AFTERNOON BEFORE WE FINALLY ERODE THE CAP.
ONCE THE CAP ERODES HOWEVER IN THE LATE AFTERNOON/EVENING WE WILL
SEE OUR BEST CHANCE FOR SHOWERS WITH THE POTENTIAL FOR STRONG TO
SEVERE THUNDERSTORMS PRODUCING STRONG GUSTY WINDS AND LOCALLY
HEAVY RAINFALL.
THE FORCING WILL COME IN THE SHAPE OF AN ADVANCING COLD FRONT AND
AHEAD OF THE COLD FRONT THE ATMOSPHERE DYNAMICS ARE SHAPING UP TO
BE A MUCH BETTER STRONG TO SEVERE CHANCE THAN SATURDAY. JUST AHEAD
OF THE FRONT WILL SEE A RAPID INCREASE IN 0-6KM BULK SHEAR TO
40-45KT WITH MID LEVEL LAPSE RATES IMPROVING TO 7-7.5 DEG C/KM.
WITH PW ALREADY 1.5 STANDARDIZE ANOMALIES ABOVE NORMAL NEARING THE
2.0" INCH RANGE EXPECT MODERATE TO HEAVY RAIN RATES WITH THE
SHOWERS THAT DEVELOP AHEAD OF THE COLD FRONT. FLASH FLOODING IS A
CONCERN BUT WITH THE LATEST MODEL TRENDS THE HIGHEST TOTAL QPF`S
ARE A BIT FURTHER TO THE WEST AND SOUTH OF THE AREA SO I OPTED TO
HOLD OFF ON A FLASH FLOOD WATCH WITH THIS ISSUANCE. MODEL GUIDANCE
CONTINUES TO SHOW A WELL DEVELOPED EML MOVING IN JUST AHEAD OF THE
FRONT SO STRONG WINDS WITH HEAVY RAINFALL WILL BE THE MAIN THREATS
WITH THIS SYSTEM.
AFTER THE FRONT CLEARS THE AREA, AND THE MODELS HAVE TRENDED
FASTER WITH THIS SYSTEM, EXPECT MONDAY TO BE QUIET AND SLIGHTLY
COOLER UNDER HIGH PRESSURE MOVING IN BEHIND THE FRONT. NORTHWEST
FLOW WILL BRING DRIER AIR INTO THE REGION WHICH SHOULD SERVE TO
CLEAR THE AREA OUT ALLOWING TEMPS TO STILL BE ABLE TO WARM TO THE
LOW 80`S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 116 PM EDT SATURDAY...MAINLY DRY CONDITIONS EXPECTED MONDAY
NIGHT WITH WEAK AREA OF HIGH PRESSURE OVER THE REGION. LATEST
TRENDS IN GUIDANCE CONTINUE TO BRING THE MID WEEK FRONT IN SOONER
SO I CONTINUED TO INCREASE THE CHANCE OF SHOWERS ON TUESDAY AS
SHORTWAVE TROUGH TROUGH AND ASSOCIATED SURFACE COLD FRONT ADVANCE
RAPIDLY EAST FROM THE GREAT LAKES. SOME MINOR INSTABILITY
INDICATED...SO OPTED FOR CONTINUITY TO INCLUDE A SLIGHT CHANCE OF
SOME EMBEDDED THUNDERSTORMS. MOSTLY CLOUDY TO OVERCAST SKIES WILL
REGULATE OUR DAYTIME TEMPS PREVENTING TEMPS FROM RISING MUCH ABOVE
SEASONAL NORMS...WITH HIGHS MAINLY IN THE LOWER 80S. AS THE FRONT
CLEARS THE AREA EXPECT THE SHOWERS TO TAPER OFF QUICKLY TUESDAY
NIGHT WITH HIGH PRESSURE AND NORTHWEST FLOW MOVING IN PLACE UNDER
A 500 MB TROUGH. DURING WEDNESDAY...ANOTHER DISTURBANCE IN THE
FLOW ALOFT COMBINED WITH INSTABILITY GENERATED FROM DAYTIME
HEATING WILL RESULT IN CHANCE OF A FEW MORE AFTERNOON SHOWERS
HOWEVER AT THIS TIME INSTABILITY IS ON THE WEAKER SIDE SO I JUST
HAVE MENTION OF RAIN SHOWERS. SURFACE HIGH PRESSURE BUILDS IN FOR
LATER IN THE WEEK. WITH LARGE UPPER TROUGH PARKED OVER EASTERN
CANADA HOWEVER...WE WILL SEE SOME CLOUDS AND THE CHANCE FOR A FEW
LIGHT SHOWERS OR SPRINKLES OVER THE HIGHER TERRAIN. TEMPERATURES
ARE EXPECTED TO BE WITHIN A FEW DEGREES OF SEASONAL NORMS DURING
THE MID-LATE WEEK PERIOD. EXPECT HIGHS IN THE UPPER 70S AND LOWER
80S WITH LOWS IN THE MID 50S TO LOWER 60S.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
THROUGH 06Z MONDAY...A VARIETY OF FLIGHT CATEGORIES OVERNIGHT WITH
SOME AREAS OF LOW CLOUDS AND FOG...AND ALSO A FEW SCATTERED SHOWERS
AND PERHAPS EVEN A THUNDERSTORM. IFR MOST LIKELY AT MPV AND
POSSIBLY SLK IN FOG. ELSEWHERE...CONDITIONS MAINLY VFR/MVFR WITH
BRIEF IFR POSSIBLE IN ANY SHOWERS.
VFR CONDITIONS RETURN EVERYWHERE AFTER 12-14Z SUNDAY BUT SCT TO
NUMEROUS SHOWERS AND THUNDERSTORMS LIKELY TO DEVELOP ACROSS
NORTHERN NEW YORK AND VERMONT BETWEEN 16-18Z. ATTM ONLY VCSH IN
TAF DUE TO TIMING/COVERAGE UNCERTAINTIES.
OUTLOOK 06Z MONDAY THROUGH THURSDAY...
06Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL MPV/SLK.
12Z TUE - 00Z FRI...MAINLY VFR. CHANCE AFTERNOON SHOWERS EACH DAY
WITH BRIEF PERIODS OF MVFR. CHANCE THUNDERSTORMS TUESDAY PM.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...NEILES/LOCONTO/SLW
SHORT TERM...DEAL
LONG TERM...DEAL
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
101 AM EDT SUN JUL 19 2015
.SYNOPSIS...
SEVERAL ROUNDS OF SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
WEEKEND. SOME STORMS MAY BE STRONG WITH GUSTY WINDS AND HEAVY
RAINFALL. BEST CHANCE FOR HEAVY RAIN WILL BE SUNDAY NIGHT AHEAD OF
A COLD FRONT WHICH WILL CROSS THE AREA LATE SUNDAY NIGHT INTO EARLY
MONDAY MORNING. WARMER THAN NORMAL TEMPERATURES THIS WEEKEND WILL
TREND BACK TOWARDS SEASONAL NORMALS DURING THE WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 101 AM EDT SUNDAY...THOUGH GENERALLY SMALL, I`VE MADE
SEVERAL CHANGES TO THE OVERNIGHT FORECAST WITH THIS UPDATE.
EARLIER SURFACE CONFLUENCE LINE WHICH HELPED TRIGGER SCATTERED
CONVECTION IN A MODERATELY-UNSTABLE AIRMASS HAS SINCE SHIFTED
INTO NEW HAMPSHIRE, AND I`VE BACKED OFF ON SHOWERS/THUNDER
THROUGH MIDNIGHT. WATER VAPOR IMAGERY AND RAP-BASED HEIGHT FIELD
PROGS INFER MID-LEVEL SHORTWAVE RIDGING NOW SPREADING ACROSS THE
NORTH COUNTRY. THAT SHOULD KEEP MUCH OF THE REGION DRY THROUGH
PART OF THE OVERNIGHT. HOWEVER, RIDGING WILL BE SHORT-LIVED AS
LEADING EDGE OF MID-LEVEL HEIGHT FALLS BEGINS TO ENTER ST.
LAWRENCE VALLEY. LATEST BTV-6 AND HRRR OUTPUT SHOW RE-DEVELOPMENT
OF SHOWERS ACROSS THIS AREA AFTER 08Z, WHICH MAY BE A
SIGNIFICANTLY WEAKER PORTION OF UPSTREAM MCS OVER THE SOUTHERN
GREAT LAKES. SO EXPECT CLOUDS TO INCREASE WITH SLIGHT CHANCE POPS
RE-INTRODUCED FOR NORTHERN NEW YORK AREAS AFTER MIDNIGHT. WITH HOW
HUMID IT IS OUTSIDE, I COULDN`T RULE OUT A RUMBLE OF THUNDER IF
ACTIVITY DEVELOPS AS PROGGED.
SPECIFIC TO THE DEWPOINT/HUMIDITY LEVELS...TEMPERATURE/DEWPOINT
SPREADS ACROSS THE NORTH COUNTRY ARE ALREADY PRETTY SMALL (WITHIN
2-4 DEGREES OF EACH OTHER). ADDITIONALLY, WITH THE POTENTIAL FOR
WINDS TO DECOUPLE, I`VE ADDED PATCHY FOG EVERYWHERE. THERE
ALREADY ARE A FEW SITES (FSO, CDA AND MVL) REPORTING EITHER FOG OR
MIST.
WITH NO CHANGE IN AIR MASS EXPECTED, THIS WILL BE A MUGGY NIGHT.
TEMPS WILL FALL VERY SLOWLY INTO THE MID 60S TO LOW 70S, CLOSE TO
OR EQUAL TO DEWPOINTS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH MONDAY NIGHT/...
AS OF 338 PM EDT SATURDAY...THE LATEST SUITE OF GUIDANCE HAS
TRENDED TO A MUCH MORE ACTIVE DAY LATE ON SUNDAY ESPECIALLY
HEADING INTO THE EVENING AND THE OVERNIGHT HOURS. SUNDAY WILL
START OFF AS A WARM MUGGY MORNING AND WILL BE THE WARMEST DAY OF
THE FORECAST PERIOD WITH SOUTHERLY SURFACE WINDS CONTINUING TO
BRING WARM AIR INTO THE REGION. EXPECT MAX TEMPS TOMORROW TO WARM
INTO THE MID 80S IN THE VALLEYS WITH SURFACE DEWPOINTS QUICKLY
RISING TO NEARLY 70 EARLY IN THE MORNING. THE COMBINATION OF HIGH
MOISTURE AND WARM TEMPS WILL RESULT IN AN UNSTABLE ATMOSPHERE WITH
PLENTY OF INSTABILITY. CURRENT FORECAST CAPE WILL RISE TO
2000-3000 J/KG BY MID AFTERNOON WITH IMPRESSION ELEVATED
INSTABILITY ALSO HOWEVER FORECAST SOUNDINGS DO SHOW A DECENT CAP
THROUGH ABOUT MID AFTERNOON. SO WIDESPREAD CONVECTION WILL BE
LIMITED THROUGH THE AFTERNOON BEFORE WE FINALLY ERODE THE CAP.
ONCE THE CAP ERODES HOWEVER IN THE LATE AFTERNOON/EVENING WE WILL
SEE OUR BEST CHANCE FOR SHOWERS WITH THE POTENTIAL FOR STRONG TO
SEVERE THUNDERSTORMS PRODUCING STRONG GUSTY WINDS AND LOCALLY
HEAVY RAINFALL.
THE FORCING WILL COME IN THE SHAPE OF AN ADVANCING COLD FRONT AND
AHEAD OF THE COLD FRONT THE ATMOSPHERE DYNAMICS ARE SHAPING UP TO
BE A MUCH BETTER STRONG TO SEVERE CHANCE THAN SATURDAY. JUST AHEAD
OF THE FRONT WILL SEE A RAPID INCREASE IN 0-6KM BULK SHEAR TO
40-45KT WITH MID LEVEL LAPSE RATES IMPROVING TO 7-7.5 DEG C/KM.
WITH PW ALREADY 1.5 STANDARDIZE ANOMALIES ABOVE NORMAL NEARING THE
2.0" INCH RANGE EXPECT MODERATE TO HEAVY RAIN RATES WITH THE
SHOWERS THAT DEVELOP AHEAD OF THE COLD FRONT. FLASH FLOODING IS A
CONCERN BUT WITH THE LATEST MODEL TRENDS THE HIGHEST TOTAL QPF`S
ARE A BIT FURTHER TO THE WEST AND SOUTH OF THE AREA SO I OPTED TO
HOLD OFF ON A FLASH FLOOD WATCH WITH THIS ISSUANCE. MODEL GUIDANCE
CONTINUES TO SHOW A WELL DEVELOPED EML MOVING IN JUST AHEAD OF THE
FRONT SO STRONG WINDS WITH HEAVY RAINFALL WILL BE THE MAIN THREATS
WITH THIS SYSTEM.
AFTER THE FRONT CLEARS THE AREA, AND THE MODELS HAVE TRENDED
FASTER WITH THIS SYSTEM, EXPECT MONDAY TO BE QUIET AND SLIGHTLY
COOLER UNDER HIGH PRESSURE MOVING IN BEHIND THE FRONT. NORTHWEST
FLOW WILL BRING DRIER AIR INTO THE REGION WHICH SHOULD SERVE TO
CLEAR THE AREA OUT ALLOWING TEMPS TO STILL BE ABLE TO WARM TO THE
LOW 80`S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 116 PM EDT SATURDAY...MAINLY DRY CONDITIONS EXPECTED MONDAY
NIGHT WITH WEAK AREA OF HIGH PRESSURE OVER THE REGION. LATEST
TRENDS IN GUIDANCE CONTINUE TO BRING THE MID WEEK FRONT IN SOONER
SO I CONTINUED TO INCREASE THE CHANCE OF SHOWERS ON TUESDAY AS
SHORTWAVE TROUGH TROUGH AND ASSOCIATED SURFACE COLD FRONT ADVANCE
RAPIDLY EAST FROM THE GREAT LAKES. SOME MINOR INSTABILITY
INDICATED...SO OPTED FOR CONTINUITY TO INCLUDE A SLIGHT CHANCE OF
SOME EMBEDDED THUNDERSTORMS. MOSTLY CLOUDY TO OVERCAST SKIES WILL
REGULATE OUR DAYTIME TEMPS PREVENTING TEMPS FROM RISING MUCH ABOVE
SEASONAL NORMS...WITH HIGHS MAINLY IN THE LOWER 80S. AS THE FRONT
CLEARS THE AREA EXPECT THE SHOWERS TO TAPER OFF QUICKLY TUESDAY
NIGHT WITH HIGH PRESSURE AND NORTHWEST FLOW MOVING IN PLACE UNDER
A 500 MB TROUGH. DURING WEDNESDAY...ANOTHER DISTURBANCE IN THE
FLOW ALOFT COMBINED WITH INSTABILITY GENERATED FROM DAYTIME
HEATING WILL RESULT IN CHANCE OF A FEW MORE AFTERNOON SHOWERS
HOWEVER AT THIS TIME INSTABILITY IS ON THE WEAKER SIDE SO I JUST
HAVE MENTION OF RAIN SHOWERS. SURFACE HIGH PRESSURE BUILDS IN FOR
LATER IN THE WEEK. WITH LARGE UPPER TROUGH PARKED OVER EASTERN
CANADA HOWEVER...WE WILL SEE SOME CLOUDS AND THE CHANCE FOR A FEW
LIGHT SHOWERS OR SPRINKLES OVER THE HIGHER TERRAIN. TEMPERATURES
ARE EXPECTED TO BE WITHIN A FEW DEGREES OF SEASONAL NORMS DURING
THE MID-LATE WEEK PERIOD. EXPECT HIGHS IN THE UPPER 70S AND LOWER
80S WITH LOWS IN THE MID 50S TO LOWER 60S.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
THROUGH 00Z MONDAY...VFR FOR THIS EVENING WITH A BRIEF PERIOD OF
MVFR POSSIBLE AT KMPV WITH SHRA/TSRA ACTIVITY E OF KBTV AT 2345Z.
LIGHT SOUTHERLY WINDS 5-10 KNOTS WILL QUICKLY BECOME LIGHT AND
VARIABLE. TYPICAL TROPICAL SKY WITH SCT LOW AND MID CLOUDS AND VFR
FOR MOST BUT EXPECT SOME MVFR CONDITIONS TO DEVELOP AFTER 08Z
WITH POSSIBLE IFR IN FOG AT MPV/SLK. REMNANTS OF GREAT LAKES MCS
AND WEAK MID-LEVEL DISTURBANCE WILL BRING CHC SHRA TO NRN NY AND
POSSIBLY CHAMPLAIN VLY BETWEEN 08-12Z SU.
VFR CONDITIONS RETURN EVERYWHERE AT 12-14Z SUN BUT SCT TO NUMEROUS
SHRA/TSRA LIKELY TO DEVELOP ACROSS NY/VT AFT 16-18Z. ATTM ONLY
VCSH IN TAF DUE TO TIMING/COVERAGE UNCERTAINTIES.
OUTLOOK 00Z MODAY THROUGH THURSDAY...
00Z MON - 12Z MON...VFR/MVFR IN PERIODS OF SHOWERS AND
THUNDERSTORMS.
12Z MON - 12Z TUE...MAINLY VFR. EARLY MORNING IFR FOG PSBL MPV/SLK.
12Z TUE - 00Z THU...MAINLY VFR. CHANCE AFTERNOON
SHOWERS/THUNDERSTORMS BOTH DAYS WITH BRIEF MVFR POSSIBLE.
&&
.MARINE...
A LAKE THUNDERSTORM ADVISORY IS CURRENTLY IN EFFECT UNTIL LATER
THIS EVENING. KCXX RADAR HAS DETECTED MULTIPLE THUNDERSTORM CELLS
MOVING ACROSS THE NORTHERN PART OF THE LAKE TOWARDS GRAND ISLE.
AFTER THESE CELLS PASS ACTIVITY IS STILL EXPECTED AROUND THE LAKE
UNTIL LATER THIS EVENING.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DEAL
NEAR TERM...NEILES/LOCONTO/SLW
SHORT TERM...DEAL
LONG TERM...DEAL
AVIATION...MV/SLW
MARINE...VERASAMY
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1049 PM EDT MON JUL 20 2015
.SYNOPSIS...BENEATH WEST TO NORTHWEST FLOW ALOFT...A PRONOUNCED LEE
SURFACE TROUGH WILL LINGER ON TUE...AHEAD OF A COLD FRONT THAT WILL
SETTLE SOUTHEAST INTO NC TUE NIGHT AND STALL AND DISSIPATE THROUGH
THE END OF THE WEEK.
&&
.NEAR TERM /TONIGHT/...
AS OF 1045 PM MONDAY...
GLANCING MID LEVEL HEIGHT FALLS ON THE SOUTHERN PERIPHERY OF A
SHORTWAVE TROUGH CROSSING THE LOWER GREAT LAKES AND OH VALLEY HAVE
EDGED EAST OF THE CENTRAL APPALACHIANS THIS EVENING. AFTER A
RELATIVELY TRANQUIL DAY MON...SCATTERED STRONG TO SEVERE STORMS
INITIATED ALONG A PRONOUNCED LEE TROUGH OVER THE NC FOOTHILLS LATE
IN THE AFTERNOON -SEEMINGLY COINCIDENT WITH BOTH THE ARRIVAL OF THE
GLANCING HEIGHT FALLS AND AN INCREASE IN SURFACE DEWPOINTS WITH THE
ONSET OF NOCTURNAL COOLING- BEFORE ORGANIZING ON ASSOCIATED MULTI-
CELL OUTFLOW AND SPREADING INTO THE SOUTHERN AND WESTERN NC PIEDMONT
DURING THE EVENING. THE HRRR CONTINUES TO INDICATE THAT THIS
ACTIVITY WILL WEAKEN WITH TIME AND EASTWARD EXTENT...WHICH SEEMS
REASONABLE AS IT MOVES AWAY FROM THE WEAK HEIGHT FALLS ALOFT
CENTERED OVER THE OH VALLEY AND INTO AN INCREASINGLY INHIBITED (CIN)
ENVIRONMENT OVER EAST-CENTRAL NC DURING THE NEXT FEW HOURS.
OTHERWISE AND ELSEWHERE...FAIR SKIES -WITH GRADUALLY THINNING
CONVECTIVE DEBRIS CLOUDINESS- AND PERSISTENCE LOWS IN THE LOW-MID
70S...ARE EXPECTED.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 245 PM MONDAY...
...HEAT ADVISORY IN EFFECT FROM 100 PM THROUGH 700 PM TUESDAY FOR
PORTIONS OF CENTRAL NC...
A FRONTAL ZONE WILL BE PUSHING SOUTH OUT OF THE OHIO VALLEY ON
TUESDAY AS THE UPPER TROF AXIS ROTATES ACROSS THE GREAT LAKES. THIS
FRONT WILL MERGE INTO THE SHARP PIEDMONT TROF TUESDAY
EVENING...WHICH WILL ENHANCE CONVECTION AFTER 20Z...WITH A CHANCE
FOR ACTIVITY TO LINGER WELL INTO THE OVERNIGHT... ESPECIALLY IN THE
SOUTHEAST. HIGHS ARE EXPECTED TO REACH MID AND UPPER 90S WITH
ASSOCIATED HEAT INDICES EXCEEDING 105...WILL NEED TO EXTEND
TOMORROWS ADVISORY A COUPLE OF COUNTIES TO THE WEST OF INTERSTATE
95. COOL AIR ADVECTION AND DRYING WILL COMMENCE AFTER MIDNIGHT WITH
LOW LEVEL FLOW VEERING NORTHERLY BEHIND THE FRONT...MINS SHOULD
RANGE FROM 70 NORTH TO 75 SOUTH...PERHAPS A COUPLE OF DEGREES COOLER
ACROSS THE NORTH IF THE SOUTHERLY SURGE OF COOLER AIR PROGRESSES A
LITTLE QUICKER.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
TO BEGIN THE LONG TERM PERIOD...A FRONT WILL BE SETTLING SOUTH OF
THE AREA ON WEDNESDAY MORNING. THIS BOUNDARY WILL LINGER JUST TO THE
SOUTH OF THE REGION THROUGH THE END OF THE WORK WEEK...BEFORE BEING
PUSHED EVEN FURTHER SOUTH BY THE WEEKEND AS A SURFACE HIGH BUILDS
DOWN FROM THE NORTHEAST. SOME DRIER AIR WILL BRIEFLY BUILD IN BEHIND
THE BOUNDARY ON WEDNESDAY...WITH MODELS PROGGING PWAT VALUES TO BE
ONLY 60-80 PERCENT OF NORMAL. THIS SHOULD LEAD TO ONLY ISOLATED
CONVECTION...MAINLY ACROSS THE SOUTHERN PORTIONS OF THE FORECAST
AREA IN THE VICINITY OF THE AFOREMENTIONED BOUNDARY AND SLIGHTLY
BETTER MOISTURE. MODELS THEN SHOW A WAVE DEVELOPING ALONG THE
BOUNDARY AND TRACKING NORTHEASTWARD LATE WEDNESDAY INTO THURSDAY.
THIS WILL INCREASE PRECIP CHANCES (MOSTLY ACROSS THE SOUTH AND EAST)
WHICH COULD LINGER INTO EARLY FRIDAY. FINALLY...DRIER WEATHER IS
EXPECTED TO RETURN FOR THE WEEKEND AS THE AFOREMENTIONED HIGH
PRESSURE SYSTEM BUILDS INTO THE REGION. CONVECTION CHANCES MAY
RETURN LATE IN THE WEEKEND/EARLY NEXT WEEK...DEPENDING ON THE TIMING
OF THE NEXT NORTHERN STREAM SHORTWAVE.
TEMPS SHOULD BE NEAR NORMAL THROUGH THE PERIOD... WITH HIGHS
GENERALLY IN THE UPPER 80S TO LOWER 90S AND OVERNIGHT LOWS IN
THE UPPER 60S TO LOWER 70S.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 810 PM MONDAY...
A CLUSTER OF STORMS MOVING ACROSS THE APPALACHIANS AND INTO THE
WESTERN PIEDMONT WILL THREATEN KGSO AND KINT THROUGH 03Z...IN WHICH
TIME A BRIEF DOWNPOUR AND 20-30KT WIND GUSTS WILL BE POSSIBLE. WITH
TIME..INSTABILITY WILL WANE AND THE STORMS WILL WEAKEN...SO IT IS
UNCERTAIN AS TO WHETHER OR NOT THE STORMS WILL MAKE IT AS FAR EAST
AS KRDU OR KRWI/KFAY. OUTSIDE OF THESE STORMS...VFR CONDITIONS ARE
EXPECTED OVERNIGHT...WITH JUST SOME ISOLATED AREAS OF MVFR VSBYS
THAT HAVE A LOW PROBABILITY OF OCCURRING AT INDIVIDUAL TAF SITES.
ISOLATED STORMS ARE POSSIBLE ON TUESDAY...WITH A WESTERLY WIND
AROUND 10KT THAT MAY GUSTS TO 16-18KT AT KINT/KGSO.
OUTLOOK...MOSTLY VFR CONDITIONS ARE EXPECTED THIS WEEK...WITH A
THREAT OF MAINLY AFTERNOON STORMS EACH DAY AS DISTURBANCES CROSS THE
AREA IN NORTHWESTERLY FLOW ALOFT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 1 PM TO 7 PM EDT TUESDAY FOR NCZ010-011-026>028-
041>043-077-078-085-086-088-089.
&&
$$
SYNOPSIS...26
NEAR TERM...26
SHORT TERM...MLM
LONG TERM...KRD
AVIATION...MLM/22
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
752 PM EDT MON JUL 20 2015
.SYNOPSIS...
A WEAK SHORTWAVE WILL MOVE EAST THROUGH THE OHIO VALLEY
TODAY...BRINGING A CHANCE OF SHOWERS AND THUNDERSTORMS...MAINLY
NEAR AND SOUTH OF THE OHIO RIVER. A COLD FRONT WILL MOVE SOUTHEAST
THROUGH THE REGION ON TUESDAY...WITH DRIER AND SLIGHTLY COOLER
CONDITIONS EXPECTED THROUGH THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE AIR MASS OVER THE OHIO VALLEY REMAINS WARM AND MOIST...THOUGH
NOT QUITE TO THE EXTENT THAT IT WAS OVER THE WEEKEND. DEWPOINTS
ARE IN THE UPPER 60S TO MID 70...BUT SURFACE TEMPERATURES ARE
GENERALLY IN THE MID 80S...RATHER THAN PUSHING TOWARD 90 DEGREES.
THERE HAVE BEEN SEVERAL LAYERS OF CLOUDS HELPING TO SLIGHTLY
INHIBIT HEATING...WITH THICK LAYERS OF CUMULUS (2500-4000 FEET)
AND SOME HIGH CLOUDS MOVING IN THE WESTERLY FLOW ALOFT.
SPC MESOANALYSIS INDICATES THAT THE SOUTHERN HALF OF THE FORECAST
AREA HAS BEEN ABLE TO DEVELOP ABOUT 1500 J/KG OF MLCAPE. A WEAK
MID-LEVEL WAVE IS FORECAST TO MOVE EAST THROUGH THE REGION THIS
EVENING...AND THERE ARE SIGNS OF A WEAK VORTICITY CENTER OVER
SOUTHEASTERN ILLINOIS...MOVING INTO INDIANA AS OF ABOUT 19Z.
SHOWER AND THUNDERSTORM DEVELOPMENT IS EXPECTED TO BEGIN DURING
THE NEXT FEW HOURS...MAINLY IMPACTING THE SOUTHERN HALF OF THE
FORECAST AREA BETWEEN 22Z-04Z. THERE APPEARS TO BE JUST ENOUGH
DEEP-LAYER SHEAR AND INSTABILITY TO SUPPORT A RISK FOR A FEW
STRONG STORMS...THOUGH NONE OF THE HIGH-RES GUIDANCE (12Z SPC-WRF
OR RECENT HRRR RUNS) INDICATE THAT DEVELOPMENT WILL BE
PARTICULARLY EXPLOSIVE. WITH WEAK FORCING THAT TIMES OUT A LITTLE
TOO LATE FOR THE PEAK OF THE DIURNAL CYCLE...THE SEVERE THREAT
APPEARS LIMITED.
PRECIPITATION POTENTIAL WILL DIMINISH DURING THE SECOND HALF OF
THE OVERNIGHT...AS THE SHORTWAVE MOVES AWAY...AND THE DIURNAL
CYCLE HEADS TOWARD ITS LOWER END. HOWEVER...THE AIR MASS WILL NOT
YET BE CHANGING SIGNIFICANTLY...AS THE APPROACHING COLD FRONT WILL
STILL BE NORTH OF THE FORECAST AREA. THUS...ANOTHER ROUND OF
FAIRLY WARM MIN TEMPS CAN BE EXPECTED...WITH LOWER 70S IN THE
SOUTH AND UPPER 60S IN THE NORTH.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
ON TUESDAY MORNING...A COLD FRONT WILL BE MOVING ACROSS THE
MICHIGAN BORDER...CONTINUING ITS SOUTHEASTWARD TREK INTO INDIANA
AND OHIO. THIS FRONT DELINEATES THE LEADING EDGE OF A SLIGHTLY
COOLER AND SIGNIFICANTLY DRIER AIR MASS...WHICH WILL BE MOVING
INTO THE OHIO VALLEY FOR THE MIDDLE OF THE WEEK.
TUESDAY WILL STILL BE A TRANSITION DAY FOR THE REGION...THOUGH
PREVAILING DRY CONDITIONS ARE LIKELY FOR MOST OF THE FORECAST
AREA. FORCING ALONG THE FRONT IS NOT PARTICULARLY STRONG...AND
OVERALL MOISTURE CONTENT IS NOTHING NOTEWORTHY FOR JULY (CLOSE TO
CLIMATOLOGICAL MEANS BETWEEN 1.0-1.5 INCHES). NORTH WINDS AND
DRIER AIR WILL ALREADY BE MOVING INTO THE NORTHERN SECTIONS OF THE
FORECAST AREA BY NOON...ESSENTIALLY ENDING ANY CHANCE FOR A
PASSING SHOWER. HOWEVER...FOR THE SOUTHEASTERN THIRD OF THE
FORECAST AREA...INSTABILITY IS EXPECTED TO BUILD AHEAD OF THE
FRONT. THUS...MAINLY BETWEEN NOON AND 6PM...SOME SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP.
WITH THE PASSAGE OF THE FRONT...THERE SHOULD BE A GRADIENT FOR MAX
TEMPS...WITH UPPER 70S IN THE NORTH AND MID 80S IN THE SOUTH.
SKIES WILL CLEAR FROM THE NORTH DURING THE EVENING...AND MOSTLY
CLEAR CONDITIONS ARE EXPECTED OVERNIGHT. WITH DEWPOINTS ALSO
SIGNIFICANTLY LOWER THAN EARLY TUESDAY MORNING (AS MUCH AS 10-15
DEGREES LOWER)...MIN TEMPS WILL EASILY BE ABLE TO DROP BELOW
NORMAL BY WEDNESDAY MORNING...IN THE UPPER 50S TO AROUND 60
DEGREES.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
HAVE USED A BLEND OF THE GFS/ECMWF/WPC FOR THE LONG TERM FORECAST.
FOR THE PERIOD WEDNESDAY THROUGH FRIDAY...AS A MID LEVEL RIDGE
REASSERTS ITSELF NORTHWARD INTO THE PLAINS...WE WILL REMAIN IN A
NORTHWEST FLOW ALOFT. SURFACE HIGH PRESSURE IS EXPECTED TO TRAVERSE
OUR REGION. AT THIS TIME...IT SHOULD REMAIN DRY...WITH JUST SOME
CLOUDS FROM TIME TO TIME.
FOR THE WEEKEND...IT NOW LOOKS LIKE A WEAK FRONTAL SYSTEM WILL PUSH
THROUGH OUR REGION. WE MAY REMAIN DRY DURING THE DAY SATURDAY...WITH
CHANCE POPS FOR SHOWERS/STORMS ADDED TO THE FORECAST FOR SATURDAY
NIGHT INTO SUNDAY.
FOR MONDAY...CURRENT FORECAST CALLS FOR DRY CONDITIONS AS MODELS
SUGGEST WE WILL BE BETWEEN SYSTEMS.
DRIER AIR AND SLIGHTLY BELOW NORMAL TEMPERATURES CAN BE EXPECTED
THROUGH AT LEAST FRIDAY...WITH AN UPTICK IN HIGHS AND HUMIDITY BY
THE WEEKEND INTO NEXT WEEK.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
H5 S/W AND CDFNT WILL PUSH ACROSS THE REGION TONIGHT. SCATTERED
TSRA HAVE ALREADY DEVELOPED OUT IN INDIANA AND ILLINOIS AND ARE
EXPECTED TO WORK EWD ACROSS THE TAFS OVERNIGHT. CVG/LUK WILL HAVE
THE BEST CHANCE TO SEE THE CONVECTION...SO WENT WITH TEMPO MVFR
FOR A PERIOD BETWEEN 03Z-06Z. ELSEWHERE ONLY WENT WITH VCTS.
FOR NOW HAVE THE TAFS DRY AFTER 09Z...BUT IF THE FRONT IS SLOWER
TO EXIT THE REGION WE COULD SEE SOME CONVECTION DEVELOP TOMORROW
MORNING. LOW LEVEL MOISTURE LINGERS THE MOST IN THE S
TOMORROW...SO POPPED A VFR CIG AT THE SRN TAFS...BUT WITH DRIER
AIR WORKING IN KEPT THE NRN TAFS SCATTERED.
WINDS WILL TURN NW TOMORROW AFTER NOON AND PICK UP OVER 10KTS.
OUTLOOK...NO SIGNIFICANT WEATHER IS EXPECTED AT THIS TIME.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...HICKMAN
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
454 PM EDT SUN JUL 19 2015
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS EVENING AS AN UPPER
DISTURBANCE PUSHES EAST AND A WEAK COLD FRONT DROPS SOUTH ACROSS
THE AREA TONIGHT. MORE SHOWERS AND STORMS WILL DEVELOP ON MONDAY
AHEAD OF ANOTHER COLD FRONT THAT WILL PUSH THROUGH THE REGION
TUESDAY MORNING. A COOLER AND LESS HUMID AIRMASS WILL SETTLE IN
FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
A COMPLEX OF SHOWERS AND THUNDERSTORMS WHICH DEVELOPED AHEAD OF A
POTENT VORT MAX CURRENTLY OVER INDIANA ARE RAPIDLY PUSHING OFF TO
THE EAST. RECENT HRRR RUNS HANDLED THIS CONVECTIVE ACTIVITY FAIRLY
WELL AND ALSO ARE PINPOINTING ANOTHER CLUSTER OF SHOWERS AND
STORMS DEVELOPING LATE THIS AFTERNOON OVER INDIANA AND SHOWS THEM
MOVING INTO THE ILN CWA AROUND 22-23Z. COVERAGE FOR THIS NEXT
ROUND OF ACTIVITY IS NOT EXPECTED TO BE AS WIDESPREAD AS
EARLIER...BUT IT SHOULD DIMINISH AND MOVE OUT OF THE ILN AREA BY
AROUND 04Z. RAIN RATES WITH THIS FIRST ROUND OF STORMS THIS
AFTERNOON WERE NOT EXTREMELY HIGH BUT CONSIDERING VERY WET SOILS
IN MANY AREAS...PW/S INCREASING TO OVER 2 INCHES ACROSS THE
CWA...AND FAVORABLE WARM CLOUD DEPTHS...WILL ALLOW THE FLASH FLOOD
WATCH TO CONTINUE THROUGH 04Z. 0-6KM SHEAR WILL INCREASE A BIT
THROUGH THIS EVENING TO AROUND 20-30 KNOTS SO CANNOT RULE OUT AN
ISOLATED STORM OR TWO...BUT DAMAGING WIND POTENTIAL WILL BE
DIMINISHING AS DCAPES WILL DROP BELOW 1000 J/KG LATE THIS
AFTERNOON INTO EARLY EVENING.
A WEAK COLD FRONT WILL DROP SOUTHEASTWARD THROUGH THE ILN CWA
OVERNIGHT...SO TONIGHT/S LOW TEMPERATURES AND DEWPOINTS WILL BE A
TAD LOWER ACROSS THE NORTHERN HALF OF THE CWA TONIGHT AS A RESULT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
THE WEAKENING COLD FRONT WILL STALL AND WASH OUT ALONG THE OHIO
RIVER MONDAY MORNING. ANOTHER SHORTWAVE WILL DIVE INTO THE OHIO
VALLEY FROM THE NORTHERN PLAINS BY LATE MONDAY AFTERNOON.
MEANWHILE...SURFACE LOW PRESSURE OVER HUDSON BAY WILL DRAG A COLD
FRONT THROUGH THE GREAT LAKES AND OHIO VALLEY REGION MONDAY NIGHT
INTO TUESDAY. THESE FORCING MECHANISMS WILL ALLOW FOR THE BEST
OPPORTUNITY FOR SHOWERS AND STORMS IN OUR AREA MONDAY AFTERNOON
AND EVENING. CONFIDENCE REMAINS LOW IN COVERAGE AND LOCATION...BUT
AT THIS TIME THE BETTER CHANCE LOOKS TO BE ACROSS MAINLY THE
SOUTHERN HALF OF THE CWA. 0-6 KM SHEAR VALUES WILL BE IN THE
20-40 KT RANGE WHILE MUCAPES WILL RANGE FROM AROUND 2000-3500
J/KG. HENCE...A CONTINUED POSSIBILITY FOR STRONG TO SEVERE STORMS
WITH THE POSSIBILITY OF SOME HEAVY RAINFALL. POTENTIAL FOR
CONVECTION WILL DIMINISH MONDAY NIGHT AS THE FRONT MOVES THROUGH
AND USHERS IN A COOLER AND LESS HUMID AIRMASS. HIGHS ON MONDAY
WILL BE IN THE MID 80S WITH TEMPERATURES DROPPING INTO THE UPPER
60S TO LOWER 70S MONDAY NIGHT.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HAVE USED A BLEND OF THE GFS/ECMWF FOR THE IMMEDIATE LONG TERM.
THEREAFTER...HAVE USED A BLEND OF ECMWF/WPC GUIDANCE.
COLD FRONT TIMING FOR TUESDAY INTO TUESDAY NIGHT IS FASTER THAN
PREVIOUS RUNS. AS S/WV ENERGY DIGS EAST THROUGH THE GREAT
LAKES...THE FRONT WILL GRADUALLY BE PUSHED SOUTHEAST THROUGH THE
REMAINDER OF THE REGION. WILL MAINTAIN A CHANCE OF SHOWERS/STORMS
FOR ALL LOCATIONS ON TUESDAY..BUT THE THREAT SHOULD COME TO AN
END BY TUESDAY EVENING AS THE FRONT PUSHES AWAY AND DRIER AIR
BUILDS IN.
FOR THE PERIOD WEDNESDAY THROUGH SATURDAY...AS MID LEVEL RIDGE TRIES
TO REASSERT ITSELF NORTHWARD INTO THE PLAINS...WE WILL REMAIN IN A
NORTHWEST FLOW ALOFT. SURFACE HIGH PRESSURE IS EXPECTED TO TRAVERSE
OUR REGION. AT THIS TIME...IT SHOULD REMAIN DRY..
BY SUNDAY...ON THE BACK SIDE OF THE HIGH...WE WILL SEE AN INCREASE
IN LOW LEVEL MOISTURE. SOME DISTURBANCES IN THE NORTHWEST FLOW
ALOFT...COMBINED WITH INCREASED INSTABILITY...MAY BRING A THREAT OF
SHOWERS AND STORMS. GIVEN THIS IS WAY OUT IN THE EXTENDED...A
TYPICAL SUMMER 30 PERCENT CHANCE WILL BE EMPLOYED.
DRIER AIR AND SLIGHTLY BELOW NORMAL TEMPERATURES CAN BE EXPECTED
THROUGH AT LEAST FRIDAY...WITH AN UPTICK IN HIGHS BY THE WEEKEND.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
SHOWERS AND THUNDERSTORMS WILL BRING MVFR CONDITIONS AT TIMES THIS
AFTERNOON AND EARLY EVENING. MID LEVEL SHORTWAVE WILL CROSS THE
OHIO VALLEY TO THE SOUTHWEST AND IS EXPECTED TO PUT AN END TO
THUNDERSTORM ACTIVITY FROM NW-SE IN THE EVENING.
MVFR VSBYS MAY BE FOUND IN THE PREDAWN HOURS AT JUST ABOUT ANY
LOCATION BUT ATTM JUST INCLUDED IT AT KLUK IN THE RIVER VALLEY.
OUTLOOK...THUNDERSTORMS POSSIBLE MONDAY THROUGH TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR OHZ026-034-
035-042>046-051>056-060>065-070>074-077>082-088.
KY...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR KYZ089>100.
IN...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR INZ050-058-
059-066-073>075-080.
&&
$$
SYNOPSIS...KURZ
NEAR TERM...KURZ
SHORT TERM...KURZ
LONG TERM...HICKMAN
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
306 AM EDT SUN JUL 19 2015
.SYNOPSIS...
VERY WARM AND HUMID CONDITIONS WILL CONTINUE THROUGH SUNDAY BEFORE
A COLD FRONT SETTLES SOUTHWARD THROUGH THE AREA AND COOLS AND
DRIES THE AIRMASS ENOUGH TO REMOVE THE DANGEROUS HEAT INDICES THAT
ARE FELT DURING THE WEEKEND. GIVEN AN EXTREMELY WARM AND UNSTABLE
AIRMASS...SHOWERS AND STORMS MAY DEVELOP AT TIMES THROUGH THE
WEEKEND WITH THE POTENTIAL TO BE STRONG TO SEVERE. THE BEST CHANCE
OF WIDESPREAD STORMS WILL BE SUNDAY AFTERNOON AND EVENING...BUT
CHANCES WILL EXIST THROUGH TONIGHT AS WELL.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STILL VERY DIFFICULT/LOW CONFIDENCE FORECAST - AS MAJORITY OF
CONVECTION ALLOWING HIGH RESOLUTION GUIDANCE CONTINUES TO STRUGGLE
MIGHTILY WITH THE EXTREMELY UNSTABLE...WEAKLY SHEARED...AND WEAKLY
FORCED ENVIRONMENT OVER THE OHIO VALLEY. DESPITE RISING HEIGHTS
OVER THE OHIO VALLEY TODAY...A CLUSTER OF STORMS HAS MAINTAINED
ITSELF INTO NWRN OHIO AND IS BEING WATCHED FOR GROWTH/DEVELOPMENT
ON PROPAGATING OUTFLOWS WITH MLCAPE IN EXCESS OF 3500 J/KG
ENTRENCHED OVER THE ILN FORECAST AREA VIA DEW POINTS IN THE MID
70S AND TEMPERATURES APPROACHING/AROUND 90F. DESPITE WEAK SHEAR
/0-6KM BULK SHEAR ABOUT 20KTS AND 0-3KM SHEAR FROM 10 TO
15KTS/...THERE IS CONCERN IN THE SHORT TERM FOR STORMS TO GROW
UPSCALE ON COLD-POOL BALANCED SYSTEM WITH INSTBY /DCAPE TO 1500
J/KG/ COMPENSATING FOR LACK OF SHEAR. SHOULD THIS OCCUR IT WOULD
SEEM A EVOLVING LINE OF STORMS MAY AFFECT MUCH OF THE CWA THIS
AFTERNOON INTO THIS EVENING WITH A WIND DAMAGE THREAT.
ALSO A COMPLICATING FACTOR...VERY WEAK/SUBTLE MCV EMINTATING OUT
OF THE CENTRAL MISSISSIPPI VALLEY MAY SPARK N-S BAND OF LOOSELY
ORGANIZED STORMS OVER INDIANA LATER THIS AFTERNOON WHICH MAY MOVE
INTO THE AREA BEFORE DIMINISHING.
LASTLY...SOME INDICATIONS IN SOME OF THE HIGHER RES GUIDANCE OF A
LATE NIGHT MCS/BOW ECHO MOVING FROM THE UPPER MISSISSIPPI VALLEY
INTO THE GREAT LAKES/OHIO VALLEY LATER IN THE NIGHT.
CONFIDENCE IS EXTREMELY LOW GIVEN HRRR INABILITY TO PROPERLY
HANDLE ONGOING CONVECTION...AND VERY POOR HANDLING OF LAST NIGHT/S
WEAKLY FORCED ACTIVITY. THUS...WILL RUN WITH STORM CHANCES MOST
AREAS FROM THE LATE AFTERNOON THROUGH THE NIGHT AND UPDATE
ACCORDINGLY AS OPPORTUNITIES PRESENT TO INCREASE RAIN CHANCES.
A VERY HUMID NIGHT IS EXPECTED /ASSUMING MCS COLD POOLS REMAIN
LOCALIZED/ WITH SOME RECORD HIGH MINIMUM TEMPS POSSIBLE IN THE
METRO AREAS. EXCESSIVE HEAT WARNING CONTINUES ALL NIGHT FOR URBAN
AREAS OF HAMILTON COUNTY...AND HEAT ADVISORIES ELSEWHERE WILL COME
DOWN BY SUNSET.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
EXPECT ANY REMNANT MCS ACTIVITY /LOW CONFIDENCE HERE/ THAT IS
STILL AROUND ON SUNDAY MORNING TO QUICKLY SHIFT OFF AND WEAKEN
LEAVING ANOTHER VERY WARM/HUMID DAY ON TAP. DEW POINTS WILL RALLY
BACK INTO THE MID 70S AHEAD OF MODERATELY STRONG COLD FRONT
APPROACHING THE AREA FROM THE NORTHWEST BY MIDDAY. THINK TEMPS
WILL BE A TOUCH COOLER MOST AREAS...WITH UPPER 80S TO AROUND 90
EXPECTED...AND MAY BE MORE SO IF CLOUD DEBRIS FROM UPSTREAM MCS
ACTIVITY IS APPRECIABLE. THUS...DO NOT FEEL COMFORTABLE EXTENDING
HEAT ADVISORY BEYOND EXTREME SW OHIO...SERN INDIANA...AND NRN KY
WHERE IT IS CURRENTLY PLACED. HEAT INDICES AREA-WIDE THOUGH WILL
BE 95-100F AND HIGHEST IN THE ADVISORY AREA /LOW 100S LIKELY/.
ADVISORY MAY NEED TO BE EXPANDED NORTH/EAST A BIT IF BETTER
INSOLATION THAN WHAT IS EXPECTED DEVELOPS.
CONVECTION SHOULD INITIATE BY 18Z ACROSS NRN OH BACK INTO INDIANA
AND SINK SSE INTO THE AREA. PRETTY STRONG AGREEMENT IN THE
GUIDANCE OF A FAIRLY SOLID LINE OF STORMS AMIDST STRONG INSTBY BUT
AGAIN MODEST TO MARGINAL SHEAR. WIND DAMAGE TO BE THE MAIN THREAT
BUT 0-3KM SHEAR VECTORS...WHILE IN GOOD ORIENTATION TO THE
FORCING...ARE A LITTLE WEAK IN MAGNITUDE. HOWEVER LIKE RECENT
DAYS...EXTREME INSTBY/DCAPE MAY AUGMENT. MAY ALSO BE A FLASH FLOOD
THREAT GIVEN ORIENTATION OF LINE BUT STORMS SHOULD PROPOGATE TO
SOME DEGREE SO WILL HOLD ON A FLASH FLOOD WATCH FOR NOW. EXPECT
LINE TO SETTLE THROUGH AND OUT OF THE AREA LATER IN THE EVENING
WITH SKIES TURNING CLEAR/PARTLY CLOUDY IN ITS WAKE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
COLD FRONT WILL BE NEAR OR JUST SOUTH OF THE OHIO RIVER BY MONDAY
MORNING WHERE IT WILL BECOME QUASI STATIONARY DURING THE DAY. WEAK
DISTURBANCES WITHIN THE FLOW ALOFT ALONG WITH THE BOUNDARY MEANS
THAT A CHANCE OF SHOWERS AND THUNDERSTORMS HAVE TO BE KEPT INTO THE
FORECAST FOR THESE LOCATIONS.
FOR MONDAY NIGHT INTO TUESDAY NIGHT...HAVE USED A BLEND OF THE NAM-
WRF AND ECMWF FOR TIMING OF NEXT S/WV ENERGY IN DEVELOPING NORTHWEST
FLOW ALOFT ALONG WITH ANOTHER COLD FRONT. AS S/WV ENERGY DIGS EAST
THROUGH THE GREAT LAKES...ANOTHER FRONT WILL GRADUALLY BE PUSHED
SOUTHEAST THROUGH THE REGION. WILL PLACE A CHANCE OF SHOWERS/STORMS
FOR ALL LOCATIONS BY TUESDAY MORNING AND CONTINUE THAT THREAT
THROUGH THE DAY. AS THE FRONT DROPS SOUTH OF THE OHIO RIVER BY
WEDNESDAY MORNING...AND WITH THE LOSS OF DAYTIME HEATING...PCPN
THREAT WILL PUSH SOUTH AND DIMINISH OVERNIGHT.
FOR THE PERIOD WEDNESDAY THROUGH FRIDAY...AS MID LEVEL RIDGE TRIES
TO REASSERT ITSELF NORTHWARD INTO THE PLAINS...WE WILL REMAIN IN A
NORTHWEST FLOW ALOFT. SURFACE HIGH PRESSURE IS EXPECTED TO TRAVERSE
OUR REGION. AT THIS TIME...IT SHOULD REMAIN DRY...EXCEPT FOR ALONG
AND SOUTH OF THE OHIO ON WEDNESDAY...WHERE LINGERING INSTABILITY MAY
POP A DIURNAL SHOWER OR STORM.
WILL CONTINUE THE DRY WEATHER INTO SATURDAY BUT BY THAT TIME MODELS
SUGGEST THAT ANOTHER WEAK FRONT MAY ARRIVE BY THEN OR SUNDAY.
TEMPERATURES WILL BE NEAR OR SLIGHTLY BELOW NORMAL THROUGH THURSDAY
WITH MAINLY TYPICAL JULY READINGS BY THE END OF THE WEEK.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
THUNDERSTORMS HAVE MOVED AWAY FROM THE TAF SITES AND REST OF THE
NIGHT SHOULD BE CONVECTION-FREE. KCVG STILL REPORTED MVFR CIG AT
06Z...OTHERWISE VFR HAS RETURNED. STILL HAVE BKN MID CLOUDS...BUT
IF THESE CLEAR BY SUNRISE THEN THERE MAY BE A PERIOD OF VIS
RESTRICTIONS IN FOG PARTICULARLY KLUK/KDAY/KILN. HAVE ALLOWED FOR
MVFR CONDITIONS LATE TONIGHT UNTIL SHORTLY AFTER SUNRISE.
SUNDAY MORNING SHOULD BEGIN DRY...BUT EXPECT AT LEAST SCATTERED
THUNDERSTORMS TO DEVELOP THIS AFTERNOON. IF LOCATION/TIMING
CONFIDENCE INCREASES...THEN MAY CONSIDER INCLUDING TEMPO GROUP FOR
MOST LIKELY TIME OF IMPACT BUT WILL HOLD ON TO VCTS FOR NOW.
OUTLOOK...THUNDERSTORMS POSSIBLE MONDAY THROUGH TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR OHZ070-071-078.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT THIS EVENING FOR OHZ077.
KY...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR KYZ089>096.
IN...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR INZ066-073>075-
080.
&&
$$
SYNOPSIS...BINAU
NEAR TERM...BINAU
SHORT TERM...BINAU
LONG TERM...HICKMAN
AVIATION...BPP
AREA FORECAST DISCUSSION
NWS PORTLAND OR
306 AM PDT SUN JUL 19 2015
.SYNOPSIS...THE NORTHEAST FLOW ALOFT THAT HAD BEEN OVER THE PACIFIC
NORTHWEST SATURDAY WILL BECOME NORTHWESTERLY TODAY AS A VERY WEAK
UPPER LEVEL DISTURBANCE MOVES INTO THE AREA. THIS IS INDUCING A
SOUTHERLY WIND REVERSAL AND SHALLOW LOW STRATUS SURGE NORTHWARD ALONG
THE COAST THIS MORNING THAT WILL BRING COOLER TEMPERATURES TO THE
COAST TODAY. THE ONSHORE FLOW THAT IS DEVELOPING ALONG THE COAST WILL
EVENTUALLY SPREAD INLAND LATER TODAY BUT NOT BEFORE ANOTHER HOT AND
MORE HUMID DAY TODAY. THE ONSHORE FLOW WILL INCREASE INLAND BY THE
EVENING AND ESPECIALLY TONIGHT AND MONDAY...CONTINUING QUITE STRONG
THROUGH THE COMING WEEK. A STRONGER UPPER TROUGH IS FORECAST TO MOVE
ONTO THE COAST TUESDAY AND LINGER THROUGH WEDNESDAY AND INTO THURSDAY
FOR MORE CLOUDS...COOLER TEMPS...AND POSSIBLY A FEW SHOWERS MAINLY
ALONG THE COAST AND OVER THE HIGHER TERRAIN NORTH OF ABOUT SALEM.
AFTER BEING IN BETWEEN SYSTEMS FRIDAY...ANOTHER UPPER TROUGH WILL TRY
TO SAG INTO THE PACIFIC NORTHWEST NEXT WEEKEND.
&&
.SHORT TERM...WITH THE NORTHEAST FLOW ALOFT FROM SATURDAY TURNING
MORE NORTHWESTERLY AS A VERY WEAK UPPER DISTURBANCE MOVES INTO THE
PACIFIC NORTHWEST...THIS HAS INDUCED A SOUTHERLY WIND REVERSAL ALONG
THE COAST AND A VERY SHALLOW LOW STRATUS SURGE NORTHWARD UP THE
COAST. THE NAM12 SEEMS TO HAVE A GOOD HANDLE ON THIS...AND THE LOW
CLOUDS AND FOG SHOULD REACH THE SOUTH WASHINGTON COAST LATER THIS
MORNING. THE LOW CLOUDS ARE QUITE SHALLOW...SO DO NOT REALLY SEEM
MUCH IF ANY INLAND PENETRATION TODAY. THE LOW CLOUDS WILL BRING
SUBSTANTIAL COOLING TO THE COAST WITH TEMPS BACK DOWN IN THE 60S AS
THE CLOUDS HANG NEAR THE COASTLINE THIS AFTERNOON. INLAND WILL REMAIN
HOT AND DRY...BUT THE MARINE AIR ALONG THE COAST WILL BEGIN SEEPING
INLAND AND RAISE THE HUMIDITIES TODAY. THE THERMAL TROUGH MOVES EAST
OF THE CASCADES THIS AFTERNOON...BUT ANY COOLING VERSUS SUNDAY WILL
BE SLIGHT. WILL CONTINUE THE CURRENT HEAT ADVISORY AS IS.
THE ONSHORE FLOW WILL INCREASE TONIGHT AND MONDAY...AND WE SHOULD SEE
MORE LOW CLOUDS SPREAD INTO THE INLAND VALLEYS BY MONDAY MORNING. WE
WILL LIKELY SEE BREEZY CONDITIONS THROUGH THE COAST RANGE AND INTO
THE VALLEYS THIS EVENING AS THE MARINE AIR SPREADS IN. THE CLOUDS
WILL LIKELY NOT BE SOLID IN THE VALLEYS MONDAY MORNING...AND WILL
CLEAR BACK TOWARD THE COAST IN THE AFTERNOON. LOOK FOR TEMPS TO FALL
BACK INTO THE 80S ON MONDAY.
THE ONSHORE FLOW WILL CONTINUE TUESDAY AS AN UPPER LOW MOVES INTO
B.C. AND AN UPPER TROUGH EXTENDING TO ITS SOUTH SWINGS INTO THE
PACIFIC NORTHWEST. CLOUDS ARE EXPECTED TO BE MORE SOLID TUESDAY
MORNING IN THE VALLEYS. INLAND TEMPS WILL FALL TO NEAR OR PERHAPS A
BIT BELOW NORMAL ON TUESDAY. SOME PATCHY DRIZZLE OR SPRINKLES ARE
POSSIBLE ALONG THE COAST AND INTO THE COAST RANGE...AND PERHAPS INTO
THE SOUTH WASHINGTON CASCADES AS WELL. TOLLESON
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
TUESDAY NIGHT THROUGH SATURDAY. EXTENDED PERIOD OF THE FORECAST IS
MARKED BY A RETURN TO SEASONABLE TEMPERATURES. A FEW SHORTWAVES
REINFORCE AN UPPER TROUGH TUE NIGHT BEFORE THE TROUGH SLIDES FURTHER
SOUTH OVER THE REGION FOR WED AND THU. WITH LOWERING H5 HEIGHTS OVER
THE REGION AND A MORE PERSISTENT MARINE LAYER...A SLIGHT CHANCE OF A
SHOWER REMAINS POSSIBLE MID WEEK ESPECIALLY OVER THE NORTHERN HALF OF
THE FORECAST AREA. MODELS SUGGEST WEAK SHORTWAVE RIDGING OVER THE
REGION LATE THU INTO FRI...SO HAVE REMOVED MENTIONABLE POPS FOR THIS
TIME...BEFORE ANOTHER WEAKER UPPER TROUGH MAY MOVE INTO THE REGION
FOR NEXT WEEKEND. CULLEN
&&
.AVIATION...VFR PREVAILING FOR ALL BUT THE COASTAL AREAS WHERE LIFR
STRATUS ALONG WITH SOME VISIBILITY RESTRICTIONS ARE OCCURRING. AS OF
10Z THE STRATUS HAS EXPANDED NORTH ALONG THE COASTLINE TO NEAR KTMK.
IT IS EXPECTED TO CONTINUE UP TO THE WASHINGTON COAST TODAY. KAST
SHOULD BE AFFECTED BY IFR CONDITIONS SHORTLY BETWEEN 14Z AND 17Z SUN.
THE STRATUS SHOULD DISSIPATE TO THE COAST THIS AFTERNOON WITH
OCCASIONAL IFR CIGS AT KAST AND KONP. STRATUS RETURNS IN DURING THE
LATE AFTERNOON OR EARLY EVENING.
KPDX AND APPROACHES...VFR THE NEXT 24 HOURS. /26
&&
.MARINE...NEARSHORE SOUTHERLY WINDS WILL CONTINUE TO EXPAND NORTHWARD
TODAY. AS OF 3 AM IT IS JUST NORTH OF GARIBALDI AND SHOULD BE NEAR
CAPE DISAPPOINTMENT BY SUNRISE. ALONG WITH THE WINDS IS LOW STRATUS
AND FOG. THE HRRR MODEL IS HANDLING THE WINDS REASONABLY WELL WITH
NEARSHORE WINDS TO ABOUT 10 NM IN THE 10 TO 15 KT RANGE. WINDS
FURTHER OFFSHORE ARE WEST TO NORTHWEST BUT WILL EVENTUALLY TURN WEST
TO SOUTHWEST LATER TODAY AND TONIGHT.
HIGH PRES OVER THE NE PAC WILL FLATTEN AND DRIFT WESTWARD LATER
TODAY. THIS WILL BRING A RETURN OF ONSHORE WINDS AND ALLOW WEAK
DISTURBANCES IN THE FLOW AND DISSIPATING FRONTS TO IMPACT THE REGION
NEXT WEEK.
SEAS ARE SLOWLY SUBSIDING WITH A FRESH SWELL NEAR 7 FT WITH A 9 TO 10
SECOND PERIOD. SEAS WILL GRADUALLY SUBSIDE TO NEAR 5 FT LATER MONDAY
AND REMAIN AROUND THIS LEVEL THROUGH MUCH OF THE WEEK. PERIODS WILL
BE IN THE 8 TO 10 SEC RANGE.
&&
.FIRE WEATHER...PREVIOUS DISCUSSION FOLLOWS...
HOT AND VERY DRY CONDITIONS PREVAIL ACROSS NORTHWEST OREGON AND
SOUTHWEST WASHINGTON THIS AFTERNOON...WITH RH LIKELY TO FALL INTO THE
TEENS LATER THIS AFTERNOON IN MANY LOCATIONS. WHILE THE ATMOSPHERIC
WIND AND STABILITY PROFILES ARE NOT QUITE ENOUGH TO WARRANT A RED
FLAG WARNING FOR EXPLOSIVE FIRE GROWTH...THERE IS STILL QUITE A BIT
OF CONCERN FOR SMALLER GRASS AND BRUSH FIRES TODAY AND SUNDAY. A WEAK
SUBSIDENCE INVERSION WILL LIKELY KEEP HUMIDITY RECOVERY POOR TONIGHT
ABOVE THERMAL BELTS...THIS INCLUDES THE WEST HILLS OF PORTLAND AND
THE HILLS SURROUNDING SALEM AND EUGENE. THERMAL LOW PRESSURE WILL
DRIFT EAST-NORTHEAST ACROSS THE CASCADES LATE SUNDAY
AFTERNOON...USHERING IN ONSHORE FLOW WHICH WILL PROBABLY START OFF
DRY FOR AREAS EAST OF THE COAST RANGE. IT WILL LIKELY TAKE UNTIL
MONDAY MORNING FOR CONSIDERABLE IMPROVEMENT IN RH TO PUSH INTO THE
FORECAST AREA.
RESIDENTS SHOULD USE EXTREME CAUTION WITH FIRE THIS WEEKEND DUE TO
THE VERY DRY VEGETATION AND HOT/DRY WEATHER. THE PROBABILITY OF A
LARGE FIRE DEVELOPING IN OUR FORECAST AREA THIS WEEKEND IS LOW...BUT
IT DOES NOT NECESSARILY TAKE A LARGE FIRE TO THREATEN LIFE AND
PROPERTY. WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HEAT ADVISORY UNTIL 9 PM PDT THIS EVENING FOR CASCADE FOOTHILLS
IN LANE COUNTY-CENTRAL COAST RANGE OF WESTERN OREGON-
CENTRAL COLUMBIA RIVER GORGE-CENTRAL WILLAMETTE VALLEY-
COAST RANGE OF NORTHWEST OREGON-GREATER PORTLAND METRO AREA-
LOWER COLUMBIA-NORTHERN OREGON CASCADE FOOTHILLS-SOUTH
WILLAMETTE VALLEY-UPPER HOOD RIVER VALLEY-WESTERN COLUMBIA
RIVER GORGE.
WA...HEAT ADVISORY UNTIL 9 PM PDT THIS EVENING FOR CENTRAL COLUMBIA
RIVER GORGE-GREATER VANCOUVER AREA-I-5 CORRIDOR IN COWLITZ
COUNTY-SOUTH WASHINGTON CASCADE FOOTHILLS-WESTERN COLUMBIA
RIVER GORGE-WILLAPA HILLS.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
9 AM PDT THIS MORNING.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
617 PM EDT SUN JUL 19 2015
.SYNOPSIS...
A PAIR OF COLD FRONTS WILL PUSH SOUTHEAST ACROSS THE REGION
TONIGHT AND ON TUESDAY. HIGH PRESSURE WILL BUILD OVER PENNSYLVANIA
DURING THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
6 PM...
EARLY CONVECTION WHICH POPPED UP IN THE HEAT OVER THE CENTRAL
MOUNTAINS HAVE DISSIPATED. OTHER THAN A FEW SPECKLES
ELSEWHERE...THE ONLY GAME IN TOWN IS NOW THE STORMS OVER THE FAR
NW. LOTS OF STORMS SEEM TO SPLIT AND LEAVE THE LEFT-MOVER AS THE
STRONGER CELL. SO HAIL IS ALSO A THREAT WITH THE WIND DAMAGE STILL
THE MAIN THREAT. HAIL MAY END UP MELTING DOWN SOME EVEN IF IT WAS
LARGE ALOFT DUE TO HOT TEMPS AND DEEP WARM CLOUD DEPTH. TWEAKS
MAINLY FOR TIMING AND PLACEMENT.
PREV...
SEVERE THUNDERSTORM WATCH #443 IS NOW IN EFFECT FOR THE NORTHERN
HALF OF CENTRAL PA THROUGH 11 PM EDT. PRELIMINARY CELLS FIRING
DUE TO DIURNAL DESTABILIZATION AND BOUNDARY LAYER THERMAL RIDGE
PUSHING EAST OF MY AREA. HOTTEST DAY OF SUMMER THUS FAR IN
PROGRESS WITH APPARENT TEMPS SURGING INTO THE 90S THROUGHOUT.
HEAT INDICES WILL TOP OUT BETWEEN 100F AND 104F ACROSS THE SUSQ
VALLEY.
VERY WARM ALOFT WITH BOUNDARY LAYER CAPPING OF EARLIER TOWERS
NOW DECREASING AS CIN ANALYSIS SHOWS DESTABLIZATION OCCURRING
OVER LAKE ERIE AND NORTHWEST PA. JUST ONE HOUR AGO...ELEVATED
HEAT SOURCE SHOWERS BRIEFLY SPROUTED OVER SOUTH MOUNTAIN BEFORE
MOVING OFF THE TERRAIN AND QUICKLY DISSIPATING. SIMILAR SHOWERS
TRYING TO GROW OVER PORTIONS OF THE CENTRAL MOUNTAINS...AND ARE
NOW OVERCOMING THE CAP. HRRR DOES DEVELOP AND PROPOGATE THIS ISOLD
TO SCT SHRA/TSRA AREA SIMILAR TO SAT EVENING ACTIVITY BEFORE
DISSIPATING IT WITH THE DECREASE IN DIURNAL HEATING BY 00Z.
MAIN ACTIVITY EXPECTED WITH APPROACHING SHORTWAVE/COLD FRONT FROM
THE EASTERN GLAKS THIS EVENING THROUGH LATE TONIGHT. NO REAL
CHANGES TO PREVIOUS THINKING...WITH NORTHERN AREAS STANDING THE
GREATEST THREAT OF STRONG TO LOCALLY SEVERE STORMS...AS THE PARENT
SHORTWAVE WILL LIFT WELL NORTH OF THE REGION THIS EVENING. FAR
SOUTHEAST MAY BE HARD PRESSED TO RAIN FROM THIS FRONT AS A RESULT
LATE TONIGHT...AS GREATER DISTANCE FROM THE WANING LG SCALE
FORCING ACCOMPANIES FROPA FURTHER SOUTH. THUS TAPERING POPS TO THE
SOUTHEAST WILL BE MAINTAINED.
COOLER/DRIER AIR IN WAKE OF COLD FRONT SHOULD MAKE SOME INROADS
ACROSS THE NW MTNS...WHERE LOWS IN THE L60S EXPECTED TONIGHT. THE
REST OF CENTRAL PA WILL REMAIN IN MUGGY AIR MASS FOR ANOTHER NIGHT
WITH LOWS BTWN 70-75F SOUTH OF I-80.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
STALLED OUT COLD FRONT NR THE MASON DIXON LINE WILL BE THE FOCUS
FOR SCT PM CONVECTION ON MONDAY. ELSEWHERE...ARRIVAL OF LOW PWAT
AIR ACROSS NORTHERN PA SHOULD ENSURE A DRY DAY. ENS MEAN 8H TEMPS
ARE SUPPORTIVE OF HIGHS FROM THE L80S OVR THE N MTNS...TO THE L90S
ACROSS THE LOWER SUSQ VALLEY.
DID NOT CHANGE MUCH ON THIS PERIOD. DID GO WITH A DRY FCST FOR THE
MORNING HOURS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
HARD TO SEE A LOT GOING ON AFTER THIS EVENING...DUE TO THE LACK
OF SFC CONVERGENCE.
DID GO WITH SOME CHC POPS LATER MONDAY INTO TUE. HIGHEST CHC
ON TUE...AS SECONDARY FRONT DROPS SE.
AFTER THIS...LOOKING AT MAINLY DRY WEATHER WED INTO FRIDAY.
SOME MODELS LIKE THE GFS40 HAVE SOME SHOWERS IN THE SW ON THU.
LEFT FCST DRY FOR NOW.
MAIN CHANGE WAS TO LOWER TEMPS MORE FOR THE PERIOD WED INTO
FRIDAY. MAIN FACTORS ARE LOWER 500 MB HEIGHTS ON THE MODELS LATELY
ALSO THE TENDENCY FOR THE AIRMASS BEHIND COLD FRONTS TO BE COLDER
THAN FCST LATELY. ALSO THE WET GROUND.
MID SHIFT DID PUT SOME SHOWERS IN FOR THE FIRST PART OF THE
WEEKEND. SOME MODELS SHOW VERY STRONG WARM ADVECTION AND
DIRECTIONAL SHEAR INTO AT LEAST NW PA ON SUNDAY. EC NOT REALLY
SHOWING MUCH OF THIS. FOR NOW...DID CARRY SHOWERS INTO SUNDAY.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
VFR CONDS PREVAILING THROUGH MID AFTERNOON. ISOLATED RESTRICTIONS
BECOME POSSIBLE IN SCT TSTMS AFTER 20Z THIS AFTERNOON OVER
NORTHERN/CENTRAL MTNS. ACTIVITY WILL CONTINUE THROUGH THE
EVENING...UNTIL A COLD FRONT DROPS ACROSS CWA OVERNIGHT. STORMS
WILL BE MOST NUMEROUS /AND IMPACTS THE BIGGEST/ ACROSS NW HALF OF
CWA...AND SOME OF THESE TSTMS WILL BE STRONG TO SEVERE WITH SIG
LOCAL SHORT-LIVED IMPACTS TO CIGS/VSBYS AND STRONG WIND GUSTS.
OTHERWISE WINDS WILL BE FROM THE SW INCREASING TO AROUND 10 MPH.
OUTLOOK...
MON...CIG RESTRICTIONS POSS NW EARLY. OTHERWISE MAINLY VFR. SCT
TSMS POSS SOUTH.
TUE...CIG RESTRICTIONS LIKELY NW HALF. CHANCE SHOWERS/TSTMS.
WED-FRI...MAINLY VFR. LOCAL A.M. FOG POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR PAZ036-056>059-
063>066.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR/MARTIN
LONG TERM...MARTIN
AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
345 PM EDT SUN JUL 19 2015
.SYNOPSIS...
A PAIR OF COLD FRONTS WILL PUSH SOUTHEAST ACROSS THE REGION
TONIGHT AND ON TUESDAY. HIGH PRESSURE WILL BUILD OVER PENNSYLVANIA
DURING THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SEVERE THUNDERSTORM WATCH #443 IS NOW IN EFFECT FOR THE NORTHERN
HALF OF CENTRAL PA THROUGH 11 PM EDT. PRELIMINARY CELLS FIRING
DUE TO DIURNAL DESTABILIZATION AND BOUNDARY LAYER THERMAL RIDGE
PUSHING EAST OF MY AREA. HOTTEST DAY OF SUMMER THUS FAR IN
PROGRESS WITH APPARENT TEMPS SURGING INTO THE 90S THROUGHOUT.
HEAT INDICES WILL TOP OUT BETWEEN 100F AND 104F ACROSS THE SUSQ
VALLEY.
VERY WARM ALOFT WITH BOUNDARY LAYER CAPPING OF EARLIER TOWERS
NOW DECREASING AS CIN ANALYSIS SHOWS DESTABLIZATION OCCURRING
OVER LAKE ERIE AND NORTHWEST PA. JUST ONE HOUR AGO...ELEVATED
HEAT SOURCE SHOWERS BRIEFLY SPROUTED OVER SOUTH MOUNTAIN BEFORE
MOVING OFF THE TERRAIN AND QUICKLY DISSIPATING. SIMILAR SHOWERS
TRYING TO GROW OVER PORTIONS OF THE CENTRAL MOUNTAINS...AND ARE
NOW OVERCOMING THE CAP. HRRR DOES DEVELOP AND PROPOGATE THIS ISOLD
TO SCT SHRA/TSRA AREA SIMILAR TO SAT EVENING ACTIVITY BEFORE
DISSIPATING IT WITH THE DECREASE IN DIURNAL HEATING BY 00Z.
MAIN ACTIVITY EXPECTED WITH APPROACHING SHORTWAVE/COLD FRONT FROM
THE EASTERN GLAKS THIS EVENING THROUGH LATE TONIGHT. NO REAL
CHANGES TO PREVIOUS THINKING...WITH NORTHERN AREAS STANDING THE
GREATEST THREAT OF STRONG TO LOCALLY SEVERE STORMS...AS THE PARENT
SHORTWAVE WILL LIFT WELL NORTH OF THE REGION THIS EVENING. FAR
SOUTHEAST MAY BE HARD PRESSED TO RAIN FROM THIS FRONT AS A RESULT
LATE TONIGHT...AS GREATER DISTANCE FROM THE WANING LG SCALE
FORCING ACCOMPANIES FROPA FURTHER SOUTH. THUS TAPERING POPS TO THE
SOUTHEAST WILL BE MAINTAINED.
COOLER/DRIER AIR IN WAKE OF COLD FRONT SHOULD MAKE SOME INROADS
ACROSS THE NW MTNS...WHERE LOWS IN THE L60S EXPECTED TONIGHT. THE
REST OF CENTRAL PA WILL REMAIN IN MUGGY AIR MASS FOR ANOTHER NIGHT
WITH LOWS BTWN 70-75F SOUTH OF I-80.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
STALLED OUT COLD FRONT NR THE MASON DIXON LINE WILL BE THE FOCUS
FOR SCT PM CONVECTION ON MONDAY. ELSEWHERE...ARRIVAL OF LOW PWAT
AIR ACROSS NORTHERN PA SHOULD ENSURE A DRY DAY. ENS MEAN 8H TEMPS
ARE SUPPORTIVE OF HIGHS FROM THE L80S OVR THE N MTNS...TO THE L90S
ACROSS THE LOWER SUSQ VALLEY.
DID NOT CHANGE MUCH ON THIS PERIOD. DID GO WITH A DRY FCST FOR THE
MORNING HOURS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
HARD TO SEE A LOT GOING ON AFTER THIS EVENING...DUE TO THE LACK
OF SFC CONVERGENCE.
DID GO WITH SOME CHC POPS LATER MONDAY INTO TUE. HIGHEST CHC
ON TUE...AS SECONDARY FRONT DROPS SE.
AFTER THIS...LOOKING AT MAINLY DRY WEATHER WED INTO FRIDAY.
SOME MODELS LIKE THE GFS40 HAVE SOME SHOWERS IN THE SW ON THU.
LEFT FCST DRY FOR NOW.
MAIN CHANGE WAS TO LOWER TEMPS MORE FOR THE PERIOD WED INTO
FRIDAY. MAIN FACTORS ARE LOWER 500 MB HEIGHTS ON THE MODELS LATELY
ALSO THE TENDENCY FOR THE AIRMASS BEHIND COLD FRONTS TO BE COLDER
THAN FCST LATELY. ALSO THE WET GROUND.
MID SHIFT DID PUT SOME SHOWERS IN FOR THE FIRST PART OF THE
WEEKEND. SOME MODELS SHOW VERY STRONG WARM ADVECTION AND
DIRECTIONAL SHEAR INTO AT LEAST NW PA ON SUNDAY. EC NOT REALLY
SHOWING MUCH OF THIS. FOR NOW...DID CARRY SHOWERS INTO SUNDAY.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
VFR CONDS PREVAILING THROUGH MID AFTERNOON. ISOLATED RESTRICTIONS
BECOME POSSIBLE IN SCT TSTMS AFTER 20Z THIS AFTERNOON OVER
NORTHERN/CENTRAL MTNS. ACTIVITY WILL CONTINUE THROUGH THE
EVENING...UNTIL A COLD FRONT DROPS ACROSS CWA OVERNIGHT. STORMS
WILL BE MOST NUMEROUS /AND IMPACTS THE BIGGEST/ ACROSS NW HALF OF
CWA...AND SOME OF THESE TSTMS WILL BE STRONG TO SEVERE WITH SIG
LOCAL SHORT-LIVED IMPACTS TO CIGS/VSBYS AND STRONG WIND GUSTS.
OTHERWISE WINDS WILL BE FROM THE SW INCREASING TO AROUND 10 MPH.
OUTLOOK...
MON...CIG RESTRICTIONS POSS NW EARLY. OTHERWISE MAINLY VFR. SCT
TSMS POSS SOUTH.
TUE...CIG RESTRICTIONS LIKELY NW HALF. CHANCE SHOWERS/TSTMS.
WED-FRI...MAINLY VFR. LOCAL A.M. FOG POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR PAZ036-056>059-
063>066.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR/MARTIN
LONG TERM...MARTIN
AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
326 PM EDT SUN JUL 19 2015
.SYNOPSIS...
A PAIR OF COLD FRONTS WILL PUSH SOUTHEAST ACROSS THE REGION
TONIGHT AND ON TUESDAY. HIGH PRESSURE WILL BUILD OVER PENNSYLVANIA
DURING THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SEVERE THUNDERSTORM WATCH #443 IS NOW IN EFFECT FOR THE NORTHERN
HALF OF CENTRAL PA THROUGH 11 PM EDT. PRELIMINARY CELLS FIRING DUE
TO DIURNAL DESTABILIZATION AND BOUNDARY LAYER THERMAL RIDGE
PUSHING EAST OF MY AREA. HOTTEST DAY OF SUMMER THUS FAR IN
PROGRESS WITH APPARENT TEMPS SURGING INTO THE 90S THROUGHOUT. HEAT
INDICES WILL TOP OUT BETWEEN 100F AND 104F ACROSS THE SUSQ VALLEY.
VERY WARM ALOFT WITH BOUNDARY LAYER CAPPING OF EARLIER TOWERS
NOW DECREASING AS CIN ANALYSIS SHOWS DESTABLIZATION OCCURRING
OVER LAKE ERIE AND NORTHWEST PA. JUST ONE HOUR AGO...ELEVATED
HEAT SOURCE SHOWERS BRIEFLY SPROUTED OVER SOUTH MOUNTAIN BEFORE
MOVING OFF THE TERRAIN AND QUICKLY DISSIPATING. SIMILAR SHOWERS
TRYING TO GROW OVER PORTIONS OF THE CENTRAL MOUNTAINS...AND ARE
NOW OVERCOMING THE CAP. HRRR DOES DEVELOP AND PROPOGATE THIS ISOLD
TO SCT SHRA/TSRA AREA SIMILAR TO SAT EVENING ACTIVITY BEFORE
DISSIPATING IT WITH THE DECREASE IN DIURNAL HEATING BY 00Z.
MAIN ACTIVITY EXPECTED WITH APPROACHING SHORTWAVE/COLD FRONT FROM
THE EASTERN GLAKS THIS EVENING THROUGH LATE TONIGHT. NO REAL
CHANGES TO PREVIOUS THINKING...WITH NORTHERN AREAS STANDING THE
GREATEST THREAT OF STRONG TO LOCALLY SEVERE STORMS...AS THE PARENT
SHORTWAVE WILL LIFT WELL NORTH OF THE REGION THIS EVENING. FAR
SOUTHEAST MAY BE HARD PRESSED TO RAIN FROM THIS FRONT AS A RESULT
LATE TONIGHT...AS GREATER DISTANCE FROM THE WANING LG SCALE
FORCING ACCOMPANIES FROPA FURTHER SOUTH. THUS TAPERING POPS TO THE
SOUTHEAST WILL BE MAINTAINED.
COOLER/DRIER AIR IN WAKE OF COLD FRONT SHOULD MAKE SOME INROADS
ACROSS THE NW MTNS...WHERE LOWS IN THE L60S EXPECTED TONIGHT. THE
REST OF CENTRAL PA WILL REMAIN IN MUGGY AIR MASS FOR ANOTHER NIGHT
WITH LOWS BTWN 70-75F SOUTH OF I-80.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
STALLED OUT COLD FRONT NR THE MASON DIXON LINE WILL BE THE FOCUS
FOR SCT PM CONVECTION ON MONDAY. ELSEWHERE...ARRIVAL OF LOW PWAT
AIR ACROSS NORTHERN PA SHOULD ENSURE A DRY DAY. ENS MEAN 8H TEMPS
ARE SUPPORTIVE OF HIGHS FROM THE L80S OVR THE N MTNS...TO THE L90S
ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
MED RANGE GUIDANCE PUSHES A SECONDARY COLD/OCCLUDED/ FRONT THRU
CENTRAL PA ON TUESDAY...LIKELY ACCOMPANIED BY A ROUND OF SCT
SHOWERS. INCREASING CONFIDENCE IN A PERIOD OF DRY/SEASONABLE WX
DURING THE SECOND HALF OF THE WEEK...WHEN ALL GUIDANCE TRACKS SFC
HIGH AND LOW PWAT AIR MASS ACROSS PA. WILL NOT MENTION PRECIP IN
THE FCST UNTIL SAT...WHEN HIGH DRIFTS OFF THE COAST AND WARMER/MORE
HUMID RETURN FLOW DEVELOPS.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
VFR CONDS PREVAILING THROUGH MID AFTERNOON. ISOLATED RESTRICTIONS
BECOME POSSIBLE IN SCT TSTMS AFTER 20Z THIS AFTERNOON OVER
NORTHERN/CENTRAL MTNS. ACTIVITY WILL CONTINUE THROUGH THE
EVENING...UNTIL A COLD FRONT DROPS ACROSS CWA OVERNIGHT. STORMS
WILL BE MOST NUMEROUS /AND IMPACTS THE BIGGEST/ ACROSS NW HALF OF
CWA...AND SOME OF THESE TSTMS WILL BE STRONG TO SEVERE WITH SIG
LOCAL SHORT-LIVED IMPACTS TO CIGS/VSBYS AND STRONG WIND GUSTS.
OTHERWISE WINDS WILL BE FROM THE SW INCREASING TO AROUND 10 MPH.
OUTLOOK...
MON...CIG RESTRICTIONS POSS NW EARLY. OTHERWISE MAINLY VFR. SCT
TSMS POSS SOUTH.
TUE...CIG RESTRICTIONS LIKELY NW HALF. CHANCE SHOWERS/TSTMS.
WED-THU...MAINLY VFR. LOCAL A.M. FOG POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR PAZ036-056>059-
063>066.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/MARTIN
AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
253 PM EDT SUN JUL 19 2015
.SYNOPSIS...
A PAIR OF COLD FRONTS WILL PUSH SOUTHEAST ACROSS THE REGION
TONIGHT AND ON TUESDAY. HIGH PRESSURE WILL BUILD OVER PENNSYLVANIA
DURING THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
HOTTEST DAY OF SUMMER THUS FAR IN PROGRESS WITH APPARENT TEMPS
SURGING INTO THE 90S THROUGHOUT. HEAT INDICES WILL TOP OUT BETWEEN
100F AND 104F ACROSS THE SUSQ VALLEY.
VERY WARM ALOFT WITH BOUNDARY LAYER TEMPERATURES CAPPING ANY
TOWERS THAT TRY TO FORM. LATEST CIN ANALYSIS SHOWS DESTABLIZATION
OCCURRING OVER LAKE ERIE WITH UP TO 100 J/KG CIN REDUCTION OVER
LAKE ERIE. ELEVATED HEAT SOURCE SHOWERS BRIEFLY SPROUTED OVER
SOUTH MOUNTAIN BEFORE MOVING OFF THE TERRAIN AND QUICKLY
DISSIPATING. SIMILAR SHOWERS TRYING TO GROW OVER PORTIONS OF THE
CENTRAL MOUNTAINS. HRRR TRIES TO DEVELOP THESE INTO AN AREA OF
ISOLD TO SCT SHRA/TSRA SIMILAR TO SAT EVENING ACTIVITY BEFORE
DISSIPATING IT WITH THE DECREASE IN DIURNAL HEATING BY 00Z.
MAIN ACTIVITY EXPECTED WITH APPROACHING SHORTWAVE/COLD FRONT FROM
THE EASTERN GLAKS LATE THIS EVENING AND LATE TONIGHT. NO REAL
CHANGES TO PREVIOUS THINKING...WITH NORTHERN AREAS STANDING THE
GREATEST THREAT OF STRONG TO LOCALLY SEVERE STORMS...AS THE PARENT
SHORTWAVE WILL LIFT WELL NORTH OF THE REGION THIS EVENING. FAR
SOUTHEAST MAY BE HARD PRESSED TO RAIN FROM THIS FRONT AS A RESULT
LATE TONIGHT...AS GREATER DISTANCE FROM THE WANING LG SCALE
FORCING ACCOMPANIES FROPA FURTHER SOUTH. THUS TAPERING POPS TO THE
SOUTHEAST WILL BE MAINTAINED.
COOLER/DRIER AIR IN WAKE OF COLD FRONT SHOULD MAKE SOME INROADS
ACROSS THE NW MTNS...WHERE LOWS IN THE L60S EXPECTED TONIGHT. THE
REST OF CENTRAL PA WILL REMAIN IN MUGGY AIR MASS FOR ANOTHER NIGHT
WITH LOWS BTWN 70-75F SOUTH OF I-80.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
STALLED OUT COLD FRONT NR THE MASON DIXON LINE WILL BE THE FOCUS
FOR SCT PM CONVECTION ON MONDAY. ELSEWHERE...ARRIVAL OF LOW PWAT
AIR ACROSS NORTHERN PA SHOULD ENSURE A DRY DAY. ENS MEAN 8H TEMPS
ARE SUPPORTIVE OF HIGHS FROM THE L80S OVR THE N MTNS...TO THE L90S
ACROSS THE LOWER SUSQ VALLEY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MED RANGE GUIDANCE PUSHES A SECONDARY COLD/OCCLUDED/ FRONT THRU
CENTRAL PA ON TUESDAY...LIKELY ACCOMPANIED BY A ROUND OF SCT
SHOWERS. INCREASING CONFIDENCE IN A PERIOD OF DRY/SEASONABLE WX
DURING THE SECOND HALF OF THE WEEK...WHEN ALL GUIDANCE TRACKS SFC
HIGH AND LOW PWAT AIR MASS ACROSS PA. WILL NOT MENTION PRECIP IN
THE FCST UNTIL SAT...WHEN HIGH DRIFTS OFF THE COAST AND WARMER/MORE
HUMID RETURN FLOW DEVELOPS.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
VFR CONDS PREVAILING THROUGH MID AFTERNOON. ISOLATED RESTRICTIONS
BECOME POSSIBLE IN SCT TSTMS AFTER 20Z THIS AFTERNOON OVER
NORTHERN/CENTRAL MTNS. ACTIVITY WILL CONTINUE THROUGH THE
EVENING...UNTIL A COLD FRONT DROPS ACROSS CWA OVERNIGHT. STORMS
WILL BE MOST NUMEROUS /AND IMPACTS THE BIGGEST/ ACROSS NW HALF OF
CWA...AND SOME OF THESE TSTMS WILL BE STRONG TO SEVERE WITH SIG
LOCAL SHORT-LIVED IMPACTS TO CIGS/VSBYS AND STRONG WIND GUSTS.
OTHERWISE WINDS WILL BE FROM THE SW INCREASING TO AROUND 10 MPH.
OUTLOOK...
MON...CIG RESTRICTIONS POSS NW EARLY. OTHERWISE MAINLY VFR. SCT
TSMS POSS SOUTH.
TUE...CIG RESTRICTIONS LIKELY NW HALF. CHANCE SHOWERS/TSTMS.
WED-THU...MAINLY VFR. LOCAL A.M. FOG POSS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR PAZ036-056>059-
063>066.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/MARTIN
AVIATION...DEVOIR/RXR
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1146 AM EDT SUN JUL 19 2015
.SYNOPSIS...
THE AREA WILL REMAIN UNDER THE INFLUENCE OF THE BERMUDA HIGH THROUGH
EARLY WEEK...BRINGING CONTINUED CHANCES FOR AFTERNOON SHOWERS AND
THUNDERSTORMS AND ABOVE AVERAGE TEMPERATURES. A WEAK FRONTAL SYSTEM
WILL MOVE INTO THE AREA ON TUESDAY...HOWEVER TEMPERATURES WILL
LIKELY REMAIN ABOVE NORMAL THROUGH NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1545 UTC UPDATE...POPS AND QPF HAVE BEEN UPDATED TO ACCOUNT FOR
CONVECTIVE ACTIVITY IN THE NORTHERN NC MOUNTAIN. SKY COVER WAS
UPDATED FROM VISIBLE SATELLITE IMAGERY. WINDS WERE UPDATED TO
INCORPORATE THE LATEST NAM GUIDANCE.
1400 UTC UPDATE...POPS AND QPF WERE UPDATED BASED ON RADAR
TRENDS....WITH AN INITIAL DECREASE EAST OF THE TN BORDER. SKY COVER
WAS UPDATED FROM SATELLITE IMAGERY...RESULTING IN A DECREASE EARLY
THIS MORNING. LITTLE CHANGE WAS MADE TO TEMPERATURES...AND HEAT
INDEX VALUES ONLY REACH ADVISORY CRITERIA IN A FEW ISOLATED
LOCATIONS IN THE FAR SE PORTION OF OUT SC AND GA PIEDMONT COUNTIES.
AS OF 645 AM...NO SIGNIFICANT CHANGES WITH THIS UPDATE. TWEAKED SKY
AND POP SLIGHTLY WITH LATEST GUIDANCE. ALSO REMOVED MOST FOG MENTION
FOR THIS MORNING...AS ONLY A FEW METARS HAVE BEEN REPORTING ANY VSBY
RESTRICTIONS.
AS OF 330 AM...A LARGE UPPER LEVEL ANTICYCLONE CONTINUES TO DOMINATE
OVER THE SOUTH-CENTRAL CONUS...PUTTING OUR AREA UNDER WEAK NWLY FLOW
ALOFT. EMBEDDED SHORTWAVES CONTINUE TO STREAM AROUND THE NRN
PERIPHERY OF THE HIGH...FROM THE CENTRAL PLAINS TO THE CAROLINAS.
THE NEXT SHORTWAVE TO CROSS OUR AREA WAS ANALYZED ON THE RAP OVER
WRN OH TO ERN KY. IT IS WEAKER THAN THE ONE THAT CROSSED THE AREA
YESTERDAY...BUT IS STILL TRIGGERING A FEW TSTMS ACRS ERN KY/TN. THIS
WAVE IS PROGGED TO SHEAR OUT AS IT ENTERS THE CWFA LATE THIS
MORNING. AT THE SFC...QUASI-STATIONARY TROF AXIS WILL BE ALIGNED
ALONG THE COASTAL PLAIN FROM SE VA TO SE GA. GUIDANCE IS IN DECENT
AGREEMENT THAT THERE WILL BE LESS INSTBY THAN YESTERDAY...AND
OVERALL LESS COVERAGE OF CONVECTION ACRS THE CWFA. THE BEST COVERAGE
LOOKS TO BE IN THE MTNS TODAY...AS THE PIEDMONT WAS WORKED OVER WELL
YESTERDAY...AND WILL SEE ONLY MODEST RECOVERY/DESTABILIZATION. WITH
THAT SAID...THICKNESSES SUPPORT MAX TEMPS SIMILAR TO YESTERDAY/S
READINGS...WHICH IS ABOUT 5-8 DEG ABOVE NORMAL. DEWPTS SHUD MIX OUT
INTO THE MID-UPR 60S EAST OF THE MTNS...SO HEAT INDEX VALUES SHUD
STAY BELOW 105. WITH LESS INSTBY...EXPECT THE SEVERE THREAT TO BE
LOW. THE NEW DAY 1 SPC CONVECTIVE OUTLOOK HAS OUR AREA IN GENERAL
THUNDER RISK TODAY.
TONIGHT...EXPECT CONVECTION TO WIND DOWN AFTER SUNSET...LEAVING
AREAS OF DEBRIS MID AND HIGH CLOUDS. PATCHY FOG WILL BE POSSIBLE
WHERE HEAVY RAIN FALLS AND IN THE MTN VLYS. MIN TEMPS WILL BE IN THE
60S IN THE MTNS AND LWR-MID 70S IN THE PIEDMONT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 320 AM SUNDAY...THE SHORT TERM PERIOD WILL SEE SOME
APPRECIABLE FLATTENING OF THE SOUTHERN CONUS UPPER RIDGE...AS LARGE
SCALE HEIGHT FALLS OVERSPREAD MUCH OF THE EASTERN CONUS IN ADVANCE
OF A SIGNIFICANT SHORT WAVE TROUGH TRAVERSING THE EXTREME NE PORTION
OF THE CONUS EARLY IN THE WORK WEEK. THIS WILL THEORETICALLY MAKE
CONDITIONS MORE FAVORABLE FOR DEEP CONVECTION BY TUE...AS STRONGER
NW FLOW ALOFT...WITH PERHAPS EMBEDDED WEAK SHORT WAVE TROUGHS
ENCROACHES ON THE AREA. IN THE INTERIM...MONDAY DOES NOT SHAPE UP TO
BE TOO TERRIBLY ACTIVE CONVECTION-WISE...AS THE AIR MASS WILL BE
RELATIVELY DRY AND NOT ALL THAT UNSTABLE ACCORDING TO A CONSENSUS OF
THE LATEST SHORT TERM MODEL GUIDANCE. INDEED...MOST MODELS FEATURE
QUITE MUTED QPF RESPONSE OVER OUR AREA MONDAY AFTERNOON...ALTHOUGH
SOME UPTICK IS POSSIBLE MONDAY EVENING...AS POTENTIALLY ORGANIZED
CONVECTION DROPS TOWARD THE AREA FROM THE NW. POPS WILL BE FEATURED
NEAR CLIMATOLOGY...WITH CHANCE OVER THE MTNS AND FHILLS...SLIGHT
CHANCE ACROSS MUCH OF THE PIEDMONT.
DEEP CONVECTIVE CHANCES WILL PERSIST THROUGH MONDAY NIGHT...WHICH
APPEARS TO BE THE PEAK TIME FOR HEIGHT FALLS ACROSS THE REGION...
WHICH MAY INTRODUCE THE LEADING EDGE OF A WEAK FRONTAL ZONE INTO THE
AREA BY THE END OF THE DAY TUESDAY. ADDITIONALLY...ANOTHER ROUND OF
ORGANIZED CONVECTION COULD APPROACH THE REGION FROM THE TENN/OHIO
VALLEYS MONDAY NIGHT/EARLY TUE. CONFIDENCE IN CONVECTIVE TRENDS FOR
TUESDAY IS QUITE LOW ATTM...AS THE POTENTIALLY STABILIZING EFFECTS
OF MORNING CONVECTION COULD HINDER DEVELOPMENT LATER IN THE
AFTERNOON. NEVERTHELESS...WITH FRONTAL ZONE MOVING INTO OR NEAR THE
AREA...WILL FEATURE SOLID CHANCE POPS IN MOST LOCATIONS...WITH EVEN
SOME LIKELIES NEAR THE TENN BORDER. CONVECTIVE CHANCES WILL
GRADUALLY DIMINISH TUE NIGHT.
THICKNESS VALUES WILL CONTINUE TO SUPPORT MAXES IN THE MID/UPPER 90S
ACROSS MUCH OF THE PIEDMONT...BUT IT REMAINS IN DOUBT WHETHER ANY
CONCENTRATED AREAS OF THE CWA WILL SEE ADVISORY CRITERIA HEAT
INDICES...ESP SINCE DEWPOINTS WILL LIKELY MIX OUT INTO THE MID-60S
IN MANY LOCATIONS MONDAY AFTERNOON...WHILE CONVECTIVE OUTFLOW AND/OR
DEBRIS CLOUDS MAY HINDER THE HEATING POTENTIAL ON TUE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 345 AM SUNDAY...THE LATEST GLOBAL MODELS FEATURE A MORE
AMPLIFIED TROUGH ALONG THE EAST COAST BY LATE-WEEK...WHICH WOULD
ALLOW FOR MORE OF A SOUTHWARD PUSH OF THE FRONTAL ZONE INTO THE
SOUTHEAST...LIKELY RESULTING IN SLIGHTLY COOLER (BUT STILL ABOVE
NORMAL) AND SOMEWHAT DRIER AIR MASS. THE RESULT COULD BE A COUPLE OF
DAYS OF RATHER TAME DEEP CONVECTIVE ACTIVITY WED AND THU...ALTHOUGH
AN ISOLATED TO WIDELY SCATTERED MENTION WILL BE MAINTAINED BOTH
DAYS. IN FACT...CLIMO-LIKE POPS WILL BE CARRIED INTO THE WEEKEND...
AS THE PATTERN APPEARS TO REMAIN SOMEWHAT STAGNANT THROUGH DAY 7.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...WELL DESPITE THE WIDESPREAD RAINFALL
YESTERDAY...THE GUIDANCE WAS TOO BULLISH ON FOG AGAIN THIS MORNING.
THIS MAY BE PARTLY DUE TO THE PERSISTENT HIGH CLOUDS STREAMING OVER
THE AREA. THERE ALSO SEEMS TO BE JUST ENUF LIGHT WIND AROUND TO
LIMIT FOG AS WELL. SO GOING WITH VFR TO START OUT ALL TAF SITES THIS
MORNING. EXPECT SCATTERED SHRA AND TSRA TO DEVELOP AGAIN THIS AFTN.
WILL GO WITH VCTS AT ALL SITES AT 18Z...THEN PROB30 STARTING AT 21Z.
EXCEPT ONLY PROB30 AT KCLT...WHERE COVERAGE IS EXPECTED TO BE LOWEST
AND IMPACTS START LATEST. WINDS WILL FAVOR A NW DIRECTION AT ALL
SITES TODAY. EARLY EVENING CONVECTION SHUD WANE AFTER SUNSET...BUT
DEBRIS CIRRUS WILL LINGER OVERNIGHT. I DON/T EXPECT MUCH FOG
TONIGHT...EXCEPT POSSIBLY AT KAVL.
OUTLOOK...THE ISOLATED TO SCATTERED AFTN/EVE SHRA AND TSRA WILL
CONTINUE EACH DAY THRU THE MIDDLE OF THE WEEK...AS SUBTROPICAL HIGH
PRES REMAINS IN CONTROL. THERE WILL ALSO BE CHANCES OF MORNING
FOG/STRATUS EACH DAY AS WELL.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-12Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% MED 72%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 94%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 94%
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
&&
.FIRE WEATHER...
THE PLANNING FORECAST HAS BEEN UPDATED THIS MORNING TO LOWER MIXING
HEIGHTS AROUND 1000 FT PER THE LATEST MODEL SOUNDINGS AND FORECAST
TEMPERATURES. SMOKE MANAGEMENT PARAMETERS HAVE BEEN ADJUSTED
ACCORDINGLY.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...ARK/JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...ARK
FIRE WEATHER...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
958 AM EDT SUN JUL 19 2015
.SYNOPSIS...
THE AREA WILL REMAIN UNDER THE INFLUENCE OF THE BERMUDA HIGH THROUGH
EARLY WEEK...BRINGING CONTINUED CHANCES FOR AFTERNOON SHOWERS AND
THUNDERSTORMS AND ABOVE AVERAGE TEMPERATURES. A WEAK FRONTAL SYSTEM
WILL MOVE INTO THE AREA ON TUESDAY...HOWEVER TEMPERATURES WILL
LIKELY REMAIN ABOVE NORMAL THROUGH NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1400 UTC UPDATE...POPS AND QPF WERE UPDATED BASED ON RADAR
TRENDS....WITH AN INITIAL DECREASE EAST OF THE TN BORDER. SKY COVER
WAS UPDATED FROM SATELLITE IMAGERY...RESULTING IN A DECREASE EARLY
THIS MORNING. LITTLE CHANGE WAS MADE TO TEMPERATURES...AND HEAT
INDEX VALUES ONLY REACH ADVISORY CRITERIA IN A FEW ISOLATED
LOCATIONS IN THE FAR SE PORTION OF OUT SC AND GA PIEDMONT COUNTIES.
AS OF 645 AM...NO SIGNIFICANT CHANGES WITH THIS UPDATE. TWEAKED SKY
AND POP SLIGHTLY WITH LATEST GUIDANCE. ALSO REMOVED MOST FOG MENTION
FOR THIS MORNING...AS ONLY A FEW METARS HAVE BEEN REPORTING ANY VSBY
RESTRICTIONS.
AS OF 330 AM...A LARGE UPPER LEVEL ANTICYCLONE CONTINUES TO DOMINATE
OVER THE SOUTH-CENTRAL CONUS...PUTTING OUR AREA UNDER WEAK NWLY FLOW
ALOFT. EMBEDDED SHORTWAVES CONTINUE TO STREAM AROUND THE NRN
PERIPHERY OF THE HIGH...FROM THE CENTRAL PLAINS TO THE CAROLINAS.
THE NEXT SHORTWAVE TO CROSS OUR AREA WAS ANALYZED ON THE RAP OVER
WRN OH TO ERN KY. IT IS WEAKER THAN THE ONE THAT CROSSED THE AREA
YESTERDAY...BUT IS STILL TRIGGERING A FEW TSTMS ACRS ERN KY/TN. THIS
WAVE IS PROGGED TO SHEAR OUT AS IT ENTERS THE CWFA LATE THIS
MORNING. AT THE SFC...QUASI-STATIONARY TROF AXIS WILL BE ALIGNED
ALONG THE COASTAL PLAIN FROM SE VA TO SE GA. GUIDANCE IS IN DECENT
AGREEMENT THAT THERE WILL BE LESS INSTBY THAN YESTERDAY...AND
OVERALL LESS COVERAGE OF CONVECTION ACRS THE CWFA. THE BEST COVERAGE
LOOKS TO BE IN THE MTNS TODAY...AS THE PIEDMONT WAS WORKED OVER WELL
YESTERDAY...AND WILL SEE ONLY MODEST RECOVERY/DESTABILIZATION. WITH
THAT SAID...THICKNESSES SUPPORT MAX TEMPS SIMILAR TO YESTERDAY/S
READINGS...WHICH IS ABOUT 5-8 DEG ABOVE NORMAL. DEWPTS SHUD MIX OUT
INTO THE MID-UPR 60S EAST OF THE MTNS...SO HEAT INDEX VALUES SHUD
STAY BELOW 105. WITH LESS INSTBY...EXPECT THE SEVERE THREAT TO BE
LOW. THE NEW DAY 1 SPC CONVECTIVE OUTLOOK HAS OUR AREA IN GENERAL
THUNDER RISK TODAY.
TONIGHT...EXPECT CONVECTION TO WIND DOWN AFTER SUNSET...LEAVING
AREAS OF DEBRIS MID AND HIGH CLOUDS. PATCHY FOG WILL BE POSSIBLE
WHERE HEAVY RAIN FALLS AND IN THE MTN VLYS. MIN TEMPS WILL BE IN THE
60S IN THE MTNS AND LWR-MID 70S IN THE PIEDMONT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 320 AM SUNDAY...THE SHORT TERM PERIOD WILL SEE SOME
APPRECIABLE FLATTENING OF THE SOUTHERN CONUS UPPER RIDGE...AS LARGE
SCALE HEIGHT FALLS OVERSPREAD MUCH OF THE EASTERN CONUS IN ADVANCE
OF A SIGNIFICANT SHORT WAVE TROUGH TRAVERSING THE EXTREME NE PORTION
OF THE CONUS EARLY IN THE WORK WEEK. THIS WILL THEORETICALLY MAKE
CONDITIONS MORE FAVORABLE FOR DEEP CONVECTION BY TUE...AS STRONGER
NW FLOW ALOFT...WITH PERHAPS EMBEDDED WEAK SHORT WAVE TROUGHS
ENCROACHES ON THE AREA. IN THE INTERIM...MONDAY DOES NOT SHAPE UP TO
BE TOO TERRIBLY ACTIVE CONVECTION-WISE...AS THE AIR MASS WILL BE
RELATIVELY DRY AND NOT ALL THAT UNSTABLE ACCORDING TO A CONSENSUS OF
THE LATEST SHORT TERM MODEL GUIDANCE. INDEED...MOST MODELS FEATURE
QUITE MUTED QPF RESPONSE OVER OUR AREA MONDAY AFTERNOON...ALTHOUGH
SOME UPTICK IS POSSIBLE MONDAY EVENING...AS POTENTIALLY ORGANIZED
CONVECTION DROPS TOWARD THE AREA FROM THE NW. POPS WILL BE FEATURED
NEAR CLIMATOLOGY...WITH CHANCE OVER THE MTNS AND FHILLS...SLIGHT
CHANCE ACROSS MUCH OF THE PIEDMONT.
DEEP CONVECTIVE CHANCES WILL PERSIST THROUGH MONDAY NIGHT...WHICH
APPEARS TO BE THE PEAK TIME FOR HEIGHT FALLS ACROSS THE REGION...
WHICH MAY INTRODUCE THE LEADING EDGE OF A WEAK FRONTAL ZONE INTO THE
AREA BY THE END OF THE DAY TUESDAY. ADDITIONALLY...ANOTHER ROUND OF
ORGANIZED CONVECTION COULD APPROACH THE REGION FROM THE TENN/OHIO
VALLEYS MONDAY NIGHT/EARLY TUE. CONFIDENCE IN CONVECTIVE TRENDS FOR
TUESDAY IS QUITE LOW ATTM...AS THE POTENTIALLY STABILIZING EFFECTS
OF MORNING CONVECTION COULD HINDER DEVELOPMENT LATER IN THE
AFTERNOON. NEVERTHELESS...WITH FRONTAL ZONE MOVING INTO OR NEAR THE
AREA...WILL FEATURE SOLID CHANCE POPS IN MOST LOCATIONS...WITH EVEN
SOME LIKELIES NEAR THE TENN BORDER. CONVECTIVE CHANCES WILL
GRADUALLY DIMINISH TUE NIGHT.
THICKNESS VALUES WILL CONTINUE TO SUPPORT MAXES IN THE MID/UPPER 90S
ACROSS MUCH OF THE PIEDMONT...BUT IT REMAINS IN DOUBT WHETHER ANY
CONCENTRATED AREAS OF THE CWA WILL SEE ADVISORY CRITERIA HEAT
INDICES...ESP SINCE DEWPOINTS WILL LIKELY MIX OUT INTO THE MID-60S
IN MANY LOCATIONS MONDAY AFTERNOON...WHILE CONVECTIVE OUTFLOW AND/OR
DEBRIS CLOUDS MAY HINDER THE HEATING POTENTIAL ON TUE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 345 AM SUNDAY...THE LATEST GLOBAL MODELS FEATURE A MORE
AMPLIFIED TROUGH ALONG THE EAST COAST BY LATE-WEEK...WHICH WOULD
ALLOW FOR MORE OF A SOUTHWARD PUSH OF THE FRONTAL ZONE INTO THE
SOUTHEAST...LIKELY RESULTING IN SLIGHTLY COOLER (BUT STILL ABOVE
NORMAL) AND SOMEWHAT DRIER AIR MASS. THE RESULT COULD BE A COUPLE OF
DAYS OF RATHER TAME DEEP CONVECTIVE ACTIVITY WED AND THU...ALTHOUGH
AN ISOLATED TO WIDELY SCATTERED MENTION WILL BE MAINTAINED BOTH
DAYS. IN FACT...CLIMO-LIKE POPS WILL BE CARRIED INTO THE WEEKEND...
AS THE PATTERN APPEARS TO REMAIN SOMEWHAT STAGNANT THROUGH DAY 7.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...WELL DESPITE THE WIDESPREAD RAINFALL
YESTERDAY...THE GUIDANCE WAS TOO BULLISH ON FOG AGAIN THIS MORNING.
THIS MAY BE PARTLY DUE TO THE PERSISTENT HIGH CLOUDS STREAMING OVER
THE AREA. THERE ALSO SEEMS TO BE JUST ENUF LIGHT WIND AROUND TO
LIMIT FOG AS WELL. SO GOING WITH VFR TO START OUT ALL TAF SITES THIS
MORNING. EXPECT SCATTERED SHRA AND TSRA TO DEVELOP AGAIN THIS AFTN.
WILL GO WITH VCTS AT ALL SITES AT 18Z...THEN PROB30 STARTING AT 21Z.
EXCEPT ONLY PROB30 AT KCLT...WHERE COVERAGE IS EXPECTED TO BE LOWEST
AND IMPACTS START LATEST. WINDS WILL FAVOR A NW DIRECTION AT ALL
SITES TODAY. EARLY EVENING CONVECTION SHUD WANE AFTER SUNSET...BUT
DEBRIS CIRRUS WILL LINGER OVERNIGHT. I DON/T EXPECT MUCH FOG
TONIGHT...EXCEPT POSSIBLY AT KAVL.
OUTLOOK...THE ISOLATED TO SCATTERED AFTN/EVE SHRA AND TSRA WILL
CONTINUE EACH DAY THRU THE MIDDLE OF THE WEEK...AS SUBTROPICAL HIGH
PRES REMAINS IN CONTROL. THERE WILL ALSO BE CHANCES OF MORNING
FOG/STRATUS EACH DAY AS WELL.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-12Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 100% HIGH 100% HIGH 100% MED 79%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 95%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% 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
&&
.FIRE WEATHER...
THE PLANNING FORECAST HAS BEEN UPDATED THIS MORNING TO LOWER MIXING
HEIGHTS AROUND 1000 FT PER THE LATEST MODEL SOUNDINGS AND FORECAST
TEMPERATURES. SMOKE MANAGEMENT PARAMETERS HAVE BEEN ADJUSTED
ACCORDINGLY.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JPT
NEAR TERM...ARK/JAT
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...ARK
FIRE WEATHER...JAT
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
352 AM EDT SUN JUL 19 2015
.SYNOPSIS...
THE AREA WILL REMAIN UNDER THE INFLUENCE OF THE BERMUDA HIGH THROUGH
EARLY WEEK...BRINGING CONTINUED CHANCES FOR AFTERNOON SHOWERS AND
THUNDERSTORMS AND ABOVE AVERAGE TEMPERATURES. A WEAK FRONTAL SYSTEM
WILL MOVE INTO THE AREA ON TUESDAY...HOWEVER TEMPERATURES WILL
LIKELY REMAIN ABOVE NORMAL THROUGH NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM...A LARGE UPPER LEVEL ANTICYCLONE CONTINUES TO DOMINATE
OVER THE SOUTH-CENTRAL CONUS...PUTTING OUR AREA UNDER WEAK NWLY FLOW
ALOFT. EMBEDDED SHORTWAVES CONTINUE TO STREAM AROUND THE NRN
PERIPHERY OF THE HIGH...FROM THE CENTRAL PLAINS TO THE CAROLINAS.
THE NEXT SHORTWAVE TO CROSS OUR AREA WAS ANALYZED ON THE RAP OVER
WRN OH TO ERN KY. IT IS WEAKER THAN THE ONE THAT CROSSED THE AREA
YESTERDAY...BUT IS STILL TRIGGERING A FEW TSTMS ACRS ERN KY/TN. THIS
WAVE IS PROGGED TO SHEAR OUT AS IT ENTERS THE CWFA LATE THIS
MORNING. AT THE SFC...QUASI-STATIONARY TROF AXIS WILL BE ALIGNED
ALONG THE COASTAL PLAIN FROM SE VA TO SE GA. GUIDANCE IS IN DECENT
AGREEMENT THAT THERE WILL BE LESS INSTBY THAN YESTERDAY...AND
OVERALL LESS COVERAGE OF CONVECTION ACRS THE CWFA. THE BEST COVERAGE
LOOKS TO BE IN THE MTNS TODAY...AS THE PIEDMONT WAS WORKED OVER WELL
YESTERDAY...AND WILL SEE ONLY MODEST RECOVERY/DESTABILIZATION.
WITH THAT SAID...THICKNESSES SUPPORT MAX TEMPS SIMILAR TO
YESTERDAY/S READINGS...WHICH IS ABOUT 5-8 DEG ABOVE NORMAL. DEWPTS
SHUD MIX OUT INTO THE MID-UPR 60S EAST OF THE MTNS...SO HEAT INDEX
VALUES SHUD STAY BELOW 105. WITH LESS INSTBY...EXPECT THE SEVERE
THREAT TO BE LOW. THE NEW DAY 1 SPC CONVECTIVE OUTLOOK HAS OUR
AREA IN GENERAL THUNDER RISK TODAY.
TONIGHT...EXPECT CONVECTION TO WIND DOWN AFTER SUNSET...LEAVING
AREAS OF DEBRIS MID AND HIGH CLOUDS. PATCHY FOG WILL BE POSSIBLE
WHERE HEAVY RAIN FALLS AND IN THE MTN VLYS. MIN TEMPS WILL BE IN THE
60S IN THE MTNS AND LWR-MID 70S IN THE PIEDMONT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 320 AM SUNDAY...THE SHORT TERM PERIOD WILL SEE SOME
APPRECIABLE FLATTENING OF THE SOUTHERN CONUS UPPER RIDGE...AS LARGE
SCALE HEIGHT FALLS OVERSPREAD MUCH OF THE EASTERN CONUS IN ADVANCE
OF A SIGNIFICANT SHORT WAVE TROUGH TRAVERSING THE EXTREME NE PORTION
OF THE CONUS EARLY IN THE WORK WEEK. THIS WILL THEORETICALLY MAKE
CONDITIONS MORE FAVORABLE FOR DEEP CONVECTION BY TUE...AS STRONGER
NW FLOW ALOFT...WITH PERHAPS EMBEDDED WEAK SHORT WAVE TROUGHS
ENCROACHES ON THE AREA. IN THE INTERIM...MONDAY DOES NOT SHAPE UP TO
BE TOO TERRIBLY ACTIVE CONVECTION-WISE...AS THE AIR MASS WILL BE
RELATIVELY DRY AND NOT ALL THAT UNSTABLE ACCORDING TO A CONSENSUS OF
THE LATEST SHORT TERM MODEL GUIDANCE. INDEED...MOST MODELS FEATURE
QUITE MUTED QPF RESPONSE OVER OUR AREA MONDAY AFTERNOON...ALTHOUGH
SOME UPTICK IS POSSIBLE MONDAY EVENING...AS POTENTIALLY ORGANIZED
CONVECTION DROPS TOWARD THE AREA FROM THE NW. POPS WILL BE FEATURED
NEAR CLIMATOLOGY...WITH CHANCE OVER THE MTNS AND FHILLS...SLIGHT
CHANCE ACROSS MUCH OF THE PIEDMONT.
DEEP CONVECTIVE CHANCES WILL PERSIST THROUGH MONDAY NIGHT...WHICH
APPEARS TO BE THE PEAK TIME FOR HEIGHT FALLS ACROSS THE REGION...
WHICH MAY INTRODUCE THE LEADING EDGE OF A WEAK FRONTAL ZONE INTO THE
AREA BY THE END OF THE DAY TUESDAY. ADDITIONALLY...ANOTHER ROUND OF
ORGANIZED CONVECTION COULD APPROACH THE REGION FROM THE TENN/OHIO
VALLEYS MONDAY NIGHT/EARLY TUE. CONFIDENCE IN CONVECTIVE TRENDS FOR
TUESDAY IS QUITE LOW ATTM...AS THE POTENTIALLY STABILIZING EFFECTS
OF MORNING CONVECTION COULD HINDER DEVELOPMENT LATER IN THE
AFTERNOON. NEVERTHELESS...WITH FRONTAL ZONE MOVING INTO OR NEAR THE
AREA...WILL FEATURE SOLID CHANCE POPS IN MOST LOCATIONS...WITH EVEN
SOME LIKELIES NEAR THE TENN BORDER. CONVECTIVE CHANCES WILL
GRADUALLY DIMINISH TUE NIGHT.
THICKNESS VALUES WILL CONTINUE TO SUPPORT MAXES IN THE MID/UPPER 90S
ACROSS MUCH OF THE PIEDMONT...BUT IT REMAINS IN DOUBT WHETHER ANY
CONCENTRATED AREAS OF THE CWA WILL SEE ADVISORY CRITERIA HEAT
INDICES...ESP SINCE DEWPOINTS WILL LIKELY MIX OUT INTO THE MID-60S
IN MANY LOCATIONS MONDAY AFTERNOON...WHILE CONVECTIVE OUTFLOW AND/OR
DEBRIS CLOUDS MAY HINDER THE HEATING POTENTIAL ON TUE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 345 AM SUNDAY...THE LATEST GLOBAL MODELS FEATURE A MORE
AMPLIFIED TROUGH ALONG THE EAST COAST BY LATE-WEEK...WHICH WOULD
ALLOW FOR MORE OF A SOUTHWARD PUSH OF THE FRONTAL ZONE INTO THE
SOUTHEAST...LIKELY RESULTING IN SLIGHTLY COOLER (BUT STILL ABOVE
NORMAL) AND SOMEWHAT DRIER AIR MASS. THE RESULT COULD BE A COUPLE OF
DAYS OF RATHER TAME DEEP CONVECTIVE ACTIVITY WED AND THU...ALTHOUGH
AN ISOLATED TO WIDELY SCATTERED MENTION WILL BE MAINTAINED BOTH
DAYS. IN FACT...CLIMO-LIKE POPS WILL BE CARRIED INTO THE WEEKEND...
AS THE PATTERN APPEARS TO REMAIN SOMEWHAT STAGNANT THROUGH DAY 7.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AT KCLT AND ELSEWHERE...NOT MUCH CHANGE IN THINKING FOR FOG AND
STRATUS POTENTIAL EARLY THIS MORNING. BASED ON TRENDS...EXPECT
PATCHY FOG AT ALL SITES BY AROUND DAYBREAK. THERE IS STILL SOME
LINGERING LIGHT WIND AND PLENTY OF HIGH CLOUDS...WHICH ARE HELPING
PREVENT MORE WIDESPREAD LOWER VSBYS. WILL CONTINUE WITH MVFR AT ALL
PIEDMONT SITES...WHILE KAVL IS EXPECTED TO GO IFR WITH COMBINATION
OF FOG AND STRATUS. THE FOG SHOULD BURN OFF QUICKLY AFTER
SUNRISE...WITH VFR CONDITIONS EXPECTED THRU THE DAY. COVERAGE OF
CONVECTION IS NOT EXPECTED TO BE AS GREAT AS YESTERDAY...AND MAY BE
FOCUSED MORE IN THE MTNS VERSUS THE PIEDMONT. WILL GO WITH PROB30 AT
ALL SITES EXCEPT AT KHKY AND KCLT...WHERE PROBS REMAIN ONLY ISOLD
(LESS THAN 25 PERCENT). WINDS WILL FAVOR A NW DIRECTION THRU THE
PERIOD...AND WILL REMAIN LIGHT.
OUTLOOK...THE ISOLATED TO SCATTERED AFTN/EVE SHRA AND TSRA WILL
CONTINUE EACH DAY THRU THE MIDDLE OF THE WEEK...AS SUBTROPICAL HIGH
PRES REMAINS IN CONTROL. THERE WILL ALSO BE CHANCES OF MORNING
FOG/STRATUS EACH DAY AS WELL.
CONFIDENCE TABLE...
08-14Z 14-20Z 20-02Z 02-06Z
KCLT MED 74% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 61% HIGH 90% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 83% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 86% HIGH 100% 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...JPT
NEAR TERM...ARK
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...ARK
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1057 AM MDT SUN JUL 19 2015
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
ISSUED AT 240 AM MDT SUN JUL 19 2015
WEAK IMPULSE AND ASSOCIATED JET STREAK WILL MOVE THROUGH THE
REGION TODAY...SUPPORTING LL THETA-E RIDGING AND ASSOCIATED LSA.
THIS WILL SUPPORT ISOLD-SCT TS ACROSS THE FA TODAY...WITH MUCH
EARLIER TIMING EXPECTED THAN PREVIOUS FORECAST DATA SUGGESTED.
EARLY MORNING POS THETA-E ADV UNDER STEEP MID LEVEL LAPSE RATES
MAY SUPPORT ISOLD SHRA/TS ACROSS NE WY AND FAR WESTERN SD...BEFORE
DIURNAL HEATING KICKS IN AND SUPPORTS MORE COVERAGE THIS
AFTERNOON. THE MAJORITY OF CONVECTION WILL BE ALONG AND SOUTH OF
INTERSTATE 90 FROM THE BH EAST...HIGHEST COVERAGE OVER SCENTRAL
SD. GIVEN FAST FLOW ALOFT WITH AN EVIDENCE JET STREAK OVER THE
FA...A FEW STRONGER CELLS WILL BE POSSIBLE. THE ONLY LIMITING
FACTOR WILL BE MARGINAL INSTABILITY WITH ONLY 500-1000 J/KG OF ML
CAPE NOTED. AMPLE FLOW AND DEEP LAYER SHEAR /35-40 KNOTS/ FOR
ISOLD ROTATING UPDRAFTS. SHRA/TS CHANCES WILL SHIFT EAST TONIGHT
ALTHOUGH A PASSING NORTHERN STREAM IMPULSE WITH AN ASSOCIATED LL
TROUGH AND STRONGER JET STREAK TO THE NE OF THE FA MAY SUPPORT A
FEW CONVECTIVE CELLS ACROSS NW SD TONIGHT. GOOD POSITIONING OF THE
JET STREAK RR ENTRANCE REGION SHOULD FAVOR SOME ELEVATED ACTIVITY
THERE.
MON...ANOTHER WEAK UPPER LEVEL IMPULSE WILL SUPPORT DIURNAL
CONVECTION ONCE AGAIN...THIS TIME ACROSS NE WY AND THE BH. BEST
INSTABILITY LOOKS TO BE OVER THE CENTRAL BH...WHERE WEAK LL FLOW
WILL SUPPORT STRONG MID RIDGE CONVERGENCE BY AFTERNOON. HAVE
BUMPED POPS TO LOW CHANCE THERE...WITH ONLY SLIGHT CHANCE MENTION
ACROSS NE WY. WEAK IMPULSE WILL SHIFT EAST MON NIGHT POSSIBLY
SUPPORTING SOME CONVECTION ACROSS SW SD. HAVE RETAINED A SLIGHT
CHANCE POP FOR THIS.
AS FOR TEMPS...SEASONAL CONDS EXPECTED WITH MAINLY 50S/60S FOR
LOWS AND 70S-80S FOR HIGHS.
.LONG TERM...TUESDAY THROUGH SATURDAY
ISSUED AT 240 AM MDT SUN JUL 19 2015
BROAD UPPER RIDGE IS PROGGED TO BE IN PLACE ACROSS THE
SOUTHERN ROCKIES AND SOUTHERN PLAINS FOR MUCH OF THE EXTENDED. WEAK
UPPER-LEVEL SHORTWAVE TROUGH WILL MOVE THROUGH THE NORTHERN PLAINS
TUESDAY THROUGH WEDNESDAY...WITH A BIT OF MODEL DISAGREEMENT ON
TIMING. NEVERTHELESS...THE LLJ SHOULD BRING MOISTURE BACK INTO THE
AREA TUESDAY...AND WHEN COMBINED WITH INCREASING MIDLEVEL LAPSE
RATES THIS SHOULD PRODUCE MLCAPE OF 500-1000 J/KG. THE NET RESULT
WILL BE CHANCES OF SHRA/TSRA FROM TUESDAY THROUGH WEDNESDAY. SHEAR
WILL BE WEAK-TO-MODERATE SO A FEW SEVERE STORMS WILL BE POSSIBLE.
FROM EARLY THURSDAY INTO FRIDAY THE MODELS ARE IN BETTER AGREEMENT
ON SOUTHWEST FLOW ALOFT WITH THE STRONGEST WESTERLIES OVER THE PAC
NORTHWEST. THIS WILL ALLOW US TO WARM UP A BIT AND KEEP THINGS
MOSTLY DRY...WITH THE EXCEPTION OF FAR NORTHERN AND WESTERN PORTIONS
OF THE AREA...WHERE SHOWERS AND STORMS COULD STRAY INTO THESE AREAS.
HOWEVER...THERE ARE SIGNS THAT THE TROUGH WILL SHIFT EAST LATER
FRIDAY WITH BETTER CHANCES OF SHRA/TSRA REACHING NWRN PARTS OF THE
CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1055 AM MDT SUN JUL 19 2015
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. A VERY SMALL CHANCE OF
SHRA/TSRA EXISTS THIS AFTN AND EVNG FROM THE BLKHLS AREA THROUGH
SCNTRL SD...WITH THE MOST LIKELY AREA OVER SCNTRL SD FROM 21-03Z.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...JC
LONG TERM...15
AVIATION...BUNKERS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
241 AM MDT SUN JUL 19 2015
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
ISSUED AT 240 AM MDT SUN JUL 19 2015
WEAK IMPULSE AND ASSOCIATED JET STREAK WILL MOVE THROUGH THE
REGION TODAY...SUPPORTING LL THETA-E RIDGING AND ASSOCIATED LSA.
THIS WILL SUPPORT ISOLD-SCT TS ACROSS THE FA TODAY...WITH MUCH
EARLIER TIMING EXPECTED THAN PREVIOUS FORECAST DATA SUGGESTED.
EARLY MORNING POS THETA-E ADV UNDER STEEP MID LEVEL LAPSE RATES
MAY SUPPORT ISOLD SHRA/TS ACROSS NE WY AND FAR WESTERN SD...BEFORE
DIURNAL HEATING KICKS IN AND SUPPORTS MORE COVERAGE THIS
AFTERNOON. THE MAJORITY OF CONVECTION WILL BE ALONG AND SOUTH OF
INTERSTATE 90 FROM THE BH EAST...HIGHEST COVERAGE OVER SCENTRAL
SD. GIVEN FAST FLOW ALOFT WITH AN EVIDENCE JET STREAK OVER THE
FA...A FEW STRONGER CELLS WILL BE POSSIBLE. THE ONLY LIMITING
FACTOR WILL BE MARGINAL INSTABILITY WITH ONLY 500-1000 J/KG OF ML
CAPE NOTED. AMPLE FLOW AND DEEP LAYER SHEAR /35-40 KNOTS/ FOR
ISOLD ROTATING UPDRAFTS. SHRA/TS CHANCES WILL SHIFT EAST TONIGHT
ALTHOUGH A PASSING NORTHERN STREAM IMPULSE WITH AN ASSOCIATED LL
TROUGH AND STRONGER JET STREAK TO THE NE OF THE FA MAY SUPPORT A
FEW CONVECTIVE CELLS ACROSS NW SD TONIGHT. GOOD POSITIONING OF THE
JET STREAK RR ENTRANCE REGION SHOULD FAVOR SOME ELEVATED ACTIVITY
THERE.
MON...ANOTHER WEAK UPPER LEVEL IMPULSE WILL SUPPORT DIURNAL
CONVECTION ONCE AGAIN...THIS TIME ACROSS NE WY AND THE BH. BEST
INSTABILITY LOOKS TO BE OVER THE CENTRAL BH...WHERE WEAK LL FLOW
WILL SUPPORT STRONG MID RIDGE CONVERGENCE BY AFTERNOON. HAVE
BUMPED POPS TO LOW CHANCE THERE...WITH ONLY SLIGHT CHANCE MENTION
ACROSS NE WY. WEAK IMPULSE WILL SHIFT EAST MON NIGHT POSSIBLY
SUPPORTING SOME CONVECTION ACROSS SW SD. HAVE RETAINED A SLIGHT
CHANCE POP FOR THIS.
AS FOR TEMPS...SEASONAL CONDS EXPECTED WITH MAINLY 50S/60S FOR
LOWS AND 70S-80S FOR HIGHS.
.LONG TERM...TUESDAY THROUGH SATURDAY
ISSUED AT 240 AM MDT SUN JUL 19 2015
BROAD UPPER RIDGE IS PROGGED TO BE IN PLACE ACROSS THE
SOUTHERN ROCKIES AND SOUTHERN PLAINS FOR MUCH OF THE EXTENDED. WEAK
UPPER-LEVEL SHORTWAVE TROUGH WILL MOVE THROUGH THE NORTHERN PLAINS
TUESDAY THROUGH WEDNESDAY...WITH A BIT OF MODEL DISAGREEMENT ON
TIMING. NEVERTHELESS...THE LLJ SHOULD BRING MOISTURE BACK INTO THE
AREA TUESDAY...AND WHEN COMBINED WITH INCREASING MIDLEVEL LAPSE
RATES THIS SHOULD PRODUCE MLCAPE OF 500-1000 J/KG. THE NET RESULT
WILL BE CHANCES OF SHRA/TSRA FROM TUESDAY THROUGH WEDNESDAY. SHEAR
WILL BE WEAK-TO-MODERATE SO A FEW SEVERE STORMS WILL BE POSSIBLE.
FROM EARLY THURSDAY INTO FRIDAY THE MODELS ARE IN BETTER AGREEMENT
ON SOUTHWEST FLOW ALOFT WITH THE STRONGEST WESTERLIES OVER THE PAC
NORTHWEST. THIS WILL ALLOW US TO WARM UP A BIT AND KEEP THINGS
MOSTLY DRY...WITH THE EXCEPTION OF FAR NORTHERN AND WESTERN PORTIONS
OF THE AREA...WHERE SHOWERS AND STORMS COULD STRAY INTO THESE AREAS.
HOWEVER...THERE ARE SIGNS THAT THE TROUGH WILL SHIFT EAST LATER
FRIDAY WITH BETTER CHANCES OF SHRA/TSRA REACHING NWRN PARTS OF THE
CWA.
&&
.AVIATION...FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT
ISSUED AT 240 AM MDT SUN JUL 19 2015
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH EARLY THIS
AFTERNOON...WITH ONLY ISOLATED TSTM POSSIBILITIES ACROSS PARTS OF
NORTHEAST WYOMING AND THE BLACK HILLS. SCATTERED THUNDERSTORMS WILL
BE POSSIBLE FROM THE BLACK HILLS INTO CENTRAL SOUTH DAKOTA DURING
THE AFTERNOON/EVENING WITH MVFR CIGS/IFR VSBY.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...JC
LONG TERM...15
AVIATION...15
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
250 PM EDT SUN JUL 19 2015
.SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...
ONGOING CONVECTION SHOULD BE MOSTLY DEAD WITH THE LOSS OF
HEATING...BUT THE NAM...WRF...AND RAP SHOW THE ACTIVITY NOW NEAR
CINCY WILL TRACK SE INTO OUR NORTHEAST SECTIONS BEGINNING AROUND
06Z. WILL KEEP CHANCE POPS GOING OVERNIGHT NORTH.
TOMORROW A SURFACE FRONT AND THE UPPER JET SINK SOUTHWARD INTO THE
VICINITY OF THE OHIO VALLEY...WHICH SHOULD HELP TO GENERATE QUITE A
BIT OF CONVECTION OVER KY THAT WILL TRACK E-SE IN THE AFTERNOON AND
EVENING. FORECAST SOUNDINGS TOMORROW APPEAR A LITTLE MORE MOIST AND
A LITTLE MORE UNSTABLE...SO COVERAGE AND INTENSITY OF STORMS SHOULD
BE GREATER THAN TODAY WITH A MARGINAL SEVERE THREAT. WILL HAVE
LIKELY POPS FOR NORTHERN SECTIONS IN THAT TIME FRAME. HEAT INDEX
VALUES WILL AGAIN BE AROUND 100 IN THE SOUTHERN VALLEY...BUT HIGHS
MAY BE A DEGREE OR TWO LOWER WITH THE EXPECTED SHOWERS AND CLOUD
COVER.
.LONG TERM (TUESDAY THROUGH SUNDAY NIGHT)...
AS THE FRONT CONTINUES TO APPROACH THE AREA ON TUESDAY...SHOWERS
AND THUNDERSTORMS ARE EXPECTED TO DEVELOP LATE MORNING LASTING
THROUGH THE AFTERNOON AND EVENING. MODELS ARE NOT AS AGGRESSIVE
WITH THE SEVERE PARAMETERS WITH THE MOST RECENT RUNS...BUT STILL
EXPECTING ISOLATED SEVERE TUESDAY AFTERNOON THROUGH EVENING. MAIN
THREAT WILL BE HEAVY RAINFALL...BUT COULD STILL SEE STRONG
WINDS...MODERATE HAIL...AND FREQUENT LIGHTNING. AS THE SUN SETS
TUESDAY EVENING...MORE A FLOODING THREAT WILL BE PRESENT WITH A
VERY MOIST PROFILE. THESE STORMS ARE EXPECTED TO LINGER THROUGH
EARLY WEDNESDAY AFTERNOON...IN THE SOUTHERN HALF OF THE AREA...WHEN
MID LEVEL DRY AIR WILL MAKES ITS WAY IN TO THE AREA.
THURSDAY THROUGH FRIDAY...AN UPPER LEVEL RIDGE WILL DEVELOP OVER THE
PLAINS STATES WITH SEVERAL SHORTWAVES MOVING AROUND THIS RIDGE SOUTH
OF THE AREA. SHOWERS AND THUNDERSTORMS COULD BE POSSIBLE EACH DAY IN
THE SOUTHERN HALF OF THE AREA AS THESE WAVES MOVE THROUGH. SATURDAY
AND SUNDAY LOOK TO HAVE THE LOWEST CHANCES OF ANY RAIN AS A
NORTHWEST FLOW SETS UP. MODELS ARE STARTING TO CATCH ON TO AN MCS
MOVING SOUTHEAST TOWARDS THE AREA FOR SATURDAY IN TO SUNDAY...BUT
STILL TOO FAR OUT TO SAY WITH MUCH CONFIDENCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 75 94 75 95 / 20 50 40 40
KNOXVILLE MCGHEE TYSON AIRPORT, TN 74 91 73 89 / 20 50 50 50
OAK RIDGE, TN 73 90 73 89 / 30 50 50 50
TRI CITIES AIRPORT, TN 70 87 70 86 / 50 60 60 60
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS/JW
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
102 PM CDT SUN JUL 19 2015
.AVIATION...
ISOLATED AFTERNOON CONVECTION HAS ALREADY FIRED UP ACROSS THE MID
STATE AT 18Z. LEFT VCTS IN CSV FORECAST FOR THIS AFTERNOON BUT
ACTIVITY SHOULD BE LIMITED ENOUGH TO NOT MENTION IN CKV AND BNA
TAFS. SHOWERS AND STORMS SHOULD DIE OFF BEFORE SUNSET. THERE IS
SOME POTENTIAL FOR NEW STORMS TO MOVE FROM KY SOUTHEASTWARD
TOWARD CSV AFTER MIDNIGHT TONIGHT...BUT AGAIN CHANCES ARE LOW SO
DID NOT INCLUDE IN TAF. WITH LIGHT WINDS AND SAME AIRMASS IN PLACE
TOMORROW...WE COULD SEE A REPEAT OF LOWER CIGS/VSBYS BRIEFLY AT
CSV TOWARD DAYBREAK MONDAY. OTHERWISE EXPECT VFR CONDITIONS
THROUGH 18Z MONDAY.
&&
.PREV DISCUSSION... /ISSUED 1115 AM CDT SUN JUL 19 2015/
UPDATE...
A FEW LATE MORNING UPDATES. HAD TO BUMP UP CURRENT DEW POINTS TO
MATCH LATEST OBS. STILL BELIEVE THESE WILL TREND DOWN SLIGHTLY THIS
AFTERNOON BUT NOT QUITE AS MUCH AS PREV FORECAST. ALSO...WILL ADD
SLIGHT CHANCE POPS IN SOUTHCENTRAL/SOUTHWEST COUNTIES FOR REST OF
TODAY. 16Z VIS SATL IMAGES ALREADY SHOWED ENHANCED CU IN THAT
AREA PLUS HRRR BREAKS OUT SOME PRECIP THERE OVER THE NEXT FEW
HOURS. REST OF PACKAGE IS ON TRACK AS WE HAVE ANOTHER HOT DAY
ACROSS THE REGION. HEAT ADVY CONTINUES TODAY AND TOMORROW.
PREV DISCUSSION... /ISSUED 629 AM CDT SUN JUL 19 2015/
AVIATION UPDATE...FOR 12Z AVIATION FORECASTS.
DISCUSSION...MOSTLY VFR CONDITIONS EXPECTED THROUGH THE FORECAST
PERIOD, EXCEPT FOR A RELATIVELY BRIEF PERIOD OF MVFR AND IFR DUE
TO BR AT CSV BTWN 10Z AND 12Z MONDAY. ISOLATED MAINLY AFTERNOON
THUNDERSTORMS ARE ALSO POSSIBLE, ESPECIALLY AROUND CSV, AND A
BRIEF PERIOD OF MVFR/IFR CONDITIONS WILL LIKELY ACCOMPANY ANY
STORM THAT MIGHT CROSS OVER A MID-STATE TERMINAL. SFC WINDS WILL
BE GENERALLY OUT OF THE SOUTHWEST BLO 10 KTS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR TNZ005>009-023>030-
056>064-075-077-093>095.
&&
$$
49
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1115 AM CDT SUN JUL 19 2015
.UPDATE...
A FEW LATE MORNING UPDATES. HAD TO BUMP UP CURRENT DEW POINTS TO
MATCH LATEST OBS. STILL BELIEVE THESE WILL TREND DOWN SLIGHTLY THIS
AFTERNOON BUT NOT QUITE AS MUCH AS PREV FORECAST. ALSO...WILL ADD
SLIGHT CHANCE POPS IN SOUTHCENTRAL/SOUTHWEST COUNTIES FOR REST OF
TODAY. 16Z VIS SATL IMAGES ALREADY SHOWED ENHANCED CU IN THAT
AREA PLUS HRRR BREAKS OUT SOME PRECIP THERE OVER THE NEXT FEW
HOURS. REST OF PACKAGE IS ON TRACK AS WE HAVE ANOTHER HOT DAY
ACROSS THE REGION. HEAT ADVY CONTINUES TODAY AND TOMORROW.
&&
.PREV DISCUSSION... /ISSUED 629 AM CDT SUN JUL 19 2015/
AVIATION UPDATE...FOR 12Z AVIATION FORECASTS.
DISCUSSION...MOSTLY VFR CONDITIONS EXPECTED THROUGH THE FORECAST
PERIOD, EXCEPT FOR A RELATIVELY BRIEF PERIOD OF MVFR AND IFR DUE
TO BR AT CSV BTWN 10Z AND 12Z MONDAY. ISOLATED MAINLY AFTERNOON
THUNDERSTORMS ARE ALSO POSSIBLE, ESPECIALLY AROUND CSV, AND A
BRIEF PERIOD OF MVFR/IFR CONDITIONS WILL LIKELY ACCOMPANY ANY
STORM THAT MIGHT CROSS OVER A MID-STATE TERMINAL. SFC WINDS WILL
BE GENERALLY OUT OF THE SOUTHWEST BLO 10 KTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 96 77 95 77 / 20 20 20 30
CLARKSVILLE 95 76 94 75 / 20 20 20 30
CROSSVILLE 90 72 88 72 / 20 20 30 30
COLUMBIA 97 75 96 76 / 20 10 20 20
LAWRENCEBURG 97 74 96 75 / 20 10 20 20
WAVERLY 96 76 95 76 / 10 10 20 20
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 7 PM CDT MONDAY FOR TNZ005>009-023>030-
056>064-075-077-093>095.
&&
$$
49
AREA FORECAST DISCUSSION
NWS AMARILLO TX
643 PM CDT MON JUL 20 2015
.AVIATION...
00Z TAFS...MEDIUM TO HIGH CONFIDENCE FOR VFR CONDITIONS THROUGH THE
PERIOD...OUTSIDE OF CONVECTION. SCATTERED THUNDERSTORMS NEAR KDHT
WILL LIKELY CONTINUE INTO THE EVENING HOURS...AND EXPECT COVERAGE OF
THUNDERSTORMS TO INCREASE THROUGH THE EVENING AND OVERNIGHT
HOURS ACROSS THE PANHANDLES....POSSIBLY INTO TUESDAY MORNING. CONFIDENCE AT
ANY PARTICULAR TAF SITE IS LOW GIVEN THE UNCERTAINTY OF COVERAGE
TONIGHT...SO AMENDMENTS TO TEMPO OR PREVAILING THUNDER GROUPS ARE
LIKELY. THE UNCERTAINTY EXTENDS INTO TOMORROW AS TONIGHT`S ACTIVITY
WILL LARGELY IMPACT COVERAGE OF CONVECTION DURING THE MORNING AND
AFTERNOON HOURS ON TUESDAY. BARRING CONVECTIVE INFLUENCE...NORTHEAST
TO EAST WINDS WILL PREVAIL AND TURN SOUTHEASTERLY TUESDAY MORNING.
ELSENHEIMER
&&
.PREV DISCUSSION... /ISSUED 242 PM CDT MON JUL 20 2015/
DISCUSSION...
LATEST WATER VAPOR CHANNEL LOOP AND GOES DERIVED TPW SHOWS ANOMALOUS
MOISTURE FLOWING NORTHWARD ACROSS EASTERN NEW MEXICO ON THE WESTERN
EDGE OF UPPER RIDGE. 12Z SOUNDINGS CONFIRM THIS WITH A SIGNIFICANT
INCREASE IN PWAT FROM 00Z LAST NIGHT (1.47 VS 0.82 INCHES). THIS IS
APPROACHING 2 STANDARD DEVIATIONS ABOVE CLIMATOLOGY. DOWNSTREAM...A
SHORTWAVE AND EXTENSIVE CONVECTION CONTINUES TO MOVE EASTWARD OUT OF
THE CENTRAL PLAINS TOWARD THE MIDDLE MISSISSIPPI VALLEY WITH WEAK
SUBSIDENCE EVIDENT BEHIND IT. VISIBLE SATELLITE REVEALS SOME
MID-HIGH LEVEL CLOUDS LEFT IN THE WAKE OF OVERNIGHT CONVECTION AND
THIS COULD POTENTIALLY LIMIT DIABATIC HEATING SOME THIS AFTERNOON
WITH A TREND TOWARD PARTIAL CLEARING IN THE FAR SOUTH TEXAS
PANHANDLE. SUBJECTIVE SURFACE ANALYSIS AT 18Z SHOWS A WEAK COLD
FRONT/COMPOSITE OUTFLOW ORIENTED NORTHEAST TO SOUTHWEST FROM NEAR
WHEELER TO JUST SOUTH OF CANYON. STORMS HAVE ALREADY FORMED NEAR
CLOVIS AND CU/TCU HAS RECENTLY FORMED NEAR THIS BOUNDARY FURTHER
EAST ACROSS THE FAR SOUTHERN PORTION OF OUR AREA. THIS SHOULD BE THE
INITIAL FOCUS WITH MORE WIDESPREAD CONVECTION OCCURRING LATER THIS
EVENING.
THE TENDENCY OF MID LEVEL HEIGHTS WILL BE TO FALL SLIGHTLY AS UPPER
RIDGE DEAMPLIFIES AND THIS SHOULD SUPPORT GREATER COVERAGE OF
CONVECTION THAN HAS BEEN SEEN IN PREVIOUS DAYS. PRESENCE OF
ANOMALOUS MOISTURE COMBINED WITH SLOW STORM MOTIONS RAISES CONCERN
FOR FLASH FLOODING. FLASH FLOOD GUIDANCE IS AT OR ABOVE CURRENT QPF
OUTPUT FROM MOST GUIDANCE. IN THE ABSENCE OF A WELL DEFINED
SHORTWAVE TO FOCUS DEVELOPMENT BELIEVE THAT THE IMPACTS WOULD BE
LOCALIZED. SOME OF THE SHORT RANGE HI-RES GUIDANCE AMOUNTS ARE MORE
AGGRESSIVE BUT THERE IS SOME QUESTION ABOUT HOW MUCH OF THIS IS
INFLUENCED BY THE BAD AWOS OBSERVATION AT PLAINVIEW/KPVW. THIS IS
GETTING INTO THE RAP AND HAS CONSISTENTLY RESULTED IN A SPURIOUS
7000+ CAPE BULLSEYE IN THE SOUTH TEXAS PANHANDLE THE LAST SEVERAL
DAYS. CAM GUIDANCE NESTED WITHIN THE RAP SUCH AS THE HRRR MAY BE
EXAGGERATED WITH CONVECTIVE COVERAGE AND QPF AS A RESULT.
SEVERE THUNDERSTORMS ARE A SECONDARY CONCERN TODAY ALTHOUGH DEEP
LAYER SHEAR SHOULD BE TOO WEAK TO SUPPORT SUSTAINED UPDRAFTS. SEVERE
EPISODES SHOULD BE BRIEF AND MARGINAL. MID LEVEL LAPSE RATES ARE NOT
PARTICULARLY STEEP WHICH IS TYPICAL FOR THIS MONSOON PATTERN BUT ARE
STEEP ENOUGH TO SUPPORT AROUND 1000 J/KG CAPE IN THE HAIL GROWTH
ZONE. ISOLATED OCCURRENCES OF MARGINALLY SEVERE HAIL ARE POSSIBLE
BUT MODERATE INSTABILITY AND WEAK SHEAR SUPPORTING FAIRLY INTENSE
BUT VERTICAL UPDRAFTS WITH WATER LOADING BENEATH STEEPENING LOW
LEVEL LAPSE RATES SHOULD SUPPORT PRIMARILY A WIND THREAT FROM BRIEF
DOWNBURSTS LATE THIS AFTERNOON THROUGH AT LEAST MID EVENING.
OVERNIGHT...WEAK ASCENT IS DEPICTED BY THE MODELS ON THE 315K
SURFACE WHICH IS FAIRLY MOIST AND THIS SHOULD BE ENOUGH TO SUSTAIN
CHANCES FOR CONVECTION INTO THE NIGHT AND IN A WEAKENED STATE
PROBABLY EVEN INTO THE MORNING HOURS ESPECIALLY ACROSS THE EAST.
SIMILAR CHALLENGES TO TODAY ARE EXPECTED TOMORROW WITH OVERNIGHT
CONVECTION AND MESOSCALE BOUNDARIES/RESIDUAL CLOUDS MAKING SPATIAL
AND TEMPORAL DETAILS UNCLEAR AT THIS POINT. FORECAST CONFIDENCE
SHOULD INCREASE LATER TONIGHT AND BY MORNING AS WE MONITOR HOW
EVENING/OVERNIGHT CONVECTION EVOLVES. STARTING WEDNESDAY MID LEVEL
HEIGHTS RISE AS UPPER HIGH BUILDS NORTH/NORTHWESTWARD ONCE AGAIN
RESULTING IN DRY WEATHER AND WARMER TEMPERATURES THROUGH AT LEAST
THE END OF THE WEEK. TOWARD SATURDAY MEDIUM RANGE GUIDANCE CONSENSUS
IS FOR RIDGE FLATTENS AGAIN AND MEAN WEST-NORTHWESTERLY FLOW MAY BE
ENOUGH FOR CONVECTION TO MOVE INTO AT LEAST WESTERN AND NORTHERN
SECTIONS.
BRB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
17/18
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
603 PM EDT SUN JUL 19 2015
.SYNOPSIS...
A SERIES UPPER LEVEL DISTURBANCES WILL KEEP SHOWERS AND STORMS IN
THE FORECAST THROUGH AT LEAST TUESDAY...WHEN AN ASSOCIATED COLD
FRONT WILL MOVE INTO AND THROUGH THE REGION. DRIER....COOLER...AND
LESS HUMID HIGH PRESSURE WILL BUILD INTO THE REGION FOR WEDNESDAY
AND THURSDAY. THE CENTER OF THE HIGH WILL SLOWLY MOVE EASTWARD
HEADING INTO THE WEEKEND...THIS WILL ALLOW FOR INCREASING
MOISTURE...PRECIPITATION CHANCES...AND WARMER CONDITIONS ACROSS THE
AREA.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 550 PM EDT SUNDAY...
QUICK UPDATE TO THE FORECAST TO REFLECT RADAR/MESO TRENDS.
ISOLATED CONVECTION MOVING OVER THE MTNS AND PIEDMONT THIS
AFTERNOON...WITH BETTER ORGANIZED LINE UPSTREAM OVER THE WV/OH/NE
KY BORDER...TRACKING SE. 20Z HRRR HAS THIS RADAR TREND PICKED UP A
BIT BUT THEN WEAKENS THIS LINE AS IT MOVES TWD OUR SE WV COUNTIES
BY 00Z. THE 21 RAP KEEPS TIMING SLOWER THAN MOVEMENT ON RADAR AND
SHOWING BEST LIFT TRACKING OVR SRN OHIO. THINK ENOUGH INSTABILITY
IN PLACE PLUS SOME MOISTURE CONVERGENCE TO KEEP CHANCE POPS IN THE
SE WV AND FAR SW VA AFTER 00Z...PER CURRENT FORECAST. THE REST OF
THE AREA WILL BE ISOLATED...WITH A FEW AREAS WHERE ITS MORE
SCATTERED THINKING MORE ACROSS SOUTHSIDE VA INTO NC...WHERE
MLCAPES ARE 3000 J/KG AT 21Z. THE AREA BETWEEN THE PIEDMONT AND
I-81 CORRIDOR IS LESS UNSTABLE AND DEALING WITH A LITTLE MORE
DOWNSLOPE PER NW FLOW ALOFT. TEMPS WILL STAY VERY WARM/HOT TIL
SUNSET EXCEPT COOLER WHERE IT RAINS. DEWPOINTS RUNNING HIGHER IN
THE SOUTH SO BUMPED THOSE UP THROUGH EARLY EVENING.
PREVIOUS DISCUSSION AT 230 PM...
ISOLATED TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
CONTINUE ACROSS PARTS OF THE AREA THROUGH THE EARLY EVENING. THE
GREATEST CONCENTRATION WILL BE THOSE PARTS OF THE AREA CURRENTLY
EXPERIENCING THIS ACTIVITY....ACROSS THE WEST AND SOUTHWEST...AND
THE SOUTH AND SOUTHEAST AND EASTERN PARTS OF THE REGION. THE AREA
FROM ROUGHLY ROANOKE NORTH TO LEWISBURG AND EAST TO LEXINGTON IS
EXPECTED TO EXPERIENCE THE LEAST COVERAGE. THE ACTIVITY WILL WANE
DURING THE EVENING HOURS AFTER SUNSET.
OVERNIGHT...GUIDANCE CONTINUES TO OFFER A SOLUTION THAT BRINGS
ANOTHER THUNDERSTORM COMPLEX SOUTHEAST INTO THE REGION DURING THE
EARLY MORNING HOURS OF MONDAY. THIS SOLUTION IS REFLECTED IN OUR
CURRENT FORECAST...AND OUR UPCOMING FORECAST WILL CONTINUE TO AS
WELL. AS THE SYSTEM HEADS SOUTHEAST THROUGH THE AREA MONDAY
MORNING...IT COULD PAN OUT SIMILARLY TO WHAT HAPPENED ON SATURDAY.
THE SYSTEM ENTERED OUR REGION...DISSIPATED...AND LEFT A RESIDUAL
STABLE AREA OF DEBRIS CLOUD COVER OVER THE REGION. CONVECTION DID
NOT RE-ESTABLISH ITSELF UNTIL LATER IN THE AFTERNOON...AND THEN ON
THE FORWARD FLANK OF THE DIFFERENTIAL HEATING ZONE OF THE DISSIPATED
SYSTEM. WHILE HIS POTENTIAL EXISTS...A DIFFERENCE FROM SATURDAY WILL
BE A REINFORCING FRONTAL BOUNDARY MOVING TOWARD THE REGION DURING
THE AFTERNOON. WHILE THERE MAY BE A PERIOD OF STABILITY IMMEDIATELY
IN THE WAKE OF THE THUNDERSTORM COMPLEX...THE APPROACH OF THE FRONT
IS EXPECTED TO REFIRE ACTIVITY...ESPECIALLY IN THE WEST...MONDAY
AFTERNOON.
TEMPERATURES WILL CONTINUE TO BE ON THE WARM/HOT AND HUMID SIDE.
LOWS TONIGHT ARE EXPECTED TO BE IN THE UPPER 60S TO AROUND 70 IN THE
MOUNTAINS WITH THE LOWER 70S ACROSS THE PIEDMONT. HIGHS ON MONDAY
WILL RANGE FROM THE MID TO UPPER 80S ACROSS THE MOUNTAINS TO THE LOW
TO MID 90S ACROSS THE PIEDMONT. HEAT INDEX VALUES ARE EXPECTED TO
AGAIN TOP 100 DEGREES...MAINLY IN AREAS ALONG AND EAST OF A
YADKINVILLE NC...MARTINSVILLE VA...LYNCHBURG VA LINE. READINGS ARE
EXPECTED TO REMAIN BELOW THE HEAT ADVISORY CRITERIA OF 105+ DEGREES
FOR A LEAST A THREE HOUR WINDOW.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 340 PM EDT SUNDAY...
THE PRIMARY SYNOPTIC FEATURE THROUGH THE PERIOD WILL BE A
DEEPENING AND BROADENING UPPER TROUGH ACROSS THE GREAT LAKES AND
EASTERN CANADIAN PROVINCES...DRIFTING TOWARD THE CANADIAN
MARITIMES BY THE END OF THE WEEK. AS HAS BEEN THE CASE
RECENTLY...A SERIES OF DISTURBANCES WILL RIDE ESE-SE WITHIN THE
BASE OF THE UPPER TROUGH...TRACKING ACROSS OUR REGION AND
IMPINGING ON A MOIST/UNSTABLE AIR MASS. BY WEDNESDAY...THE TROUGH
WILL FINALLY DEEPEN ENOUGH TO PUSH A COLD FRONT/WEAK BOUNDARY
SOUTH OF THE AREA...WHICH WILL AT LEAST BRIEFLY GIVE MUCH OF THE
CWA A RESPITE FROM THE RECENT HIGH DEWPOINTS/RELATIVE HUMIDITY
AND VERY WARM TEMPERATURES.
THE KEY TO THIS FORECAST PERIOD WILL BE TIMING OF UPPER-LEVEL
SHORT WAVES/DISTURBANCES AND ASSOCIATED CONVECTION. ONE SUCH SHORT
WAVE SHOULD BE DRIFTING EAST OF THE AREA MONDAY EVENING/MONDAY
NIGHT...BUT ANOTHER STRONGER...MORE ORGANIZED
DISTURBANCE...AND WHAT APPEARS TO BE THE MAIN DISTURBANCE TIED TO
PUSHING THE FRONT AND DRIER AIR FURTHER SOUTH...WILL BE LOCATED
ACROSS THE MIDWEST/WESTERN GREAT LAKES. ONCE AGAIN IT APPEARS THAT
AN ASSOCIATED MCS WITH THIS LATER DISTURBANCE WILL DRIFT INTO THE
CWA EARLY TUESDAY MORNING. THIS SHOULD LEAVE THE WESTERN AREAS
WITH CONSIDERABLE CLOUD COVER/LIGHT SHOWERS/ISOLATED THUNDERSTORMS
IN THE MORNING...THEN POSSIBLE REDEVELOPMENT EAST OF THE BLUE
RIDGE BY AFTERNOON. CONFIDENCE IN THE LATER POSSIBILITY IS LOW AT
THIS POINT AS TIMING IS EVERYTHING WITH THIS TYPE OF CONVECTIVE
DEVELOPMENT.
BY TUESDAY EVENING/NIGHT...THE FRONT BECOMES MORE WEST-EAST
ORIENTED JUST TO OUR SOUTH. CONFIDENCE IN THE FRONT ACTUALLY
PUSHING COMPLETELY SOUTH OF THE CWA AND TAKING ALL OF THE
ASSOCIATED CONVECTION WITH IT IS LOW AT THIS POINT. YET ANOTHER
UPPER-LEVEL DISTURBANCE IS EVIDENT UPSTREAM ACROSS OK/KS/MO
AREA...WHICH LIKELY WILL BUCKLE THE FRONT BACK TO THE NORTH IN THE
WESTERN AREAS. THIS SCENARIO SHOULD RESULT IN A RESURGENCE OF
CONVECTION BACK INTO THE SOUTHWEST PART OF THE CWA WED
AFTERNOON/EVENING...BUT THE NORTHEASTERN TWO-THIRDS OF THE CWA
SHOULD BE DRY. ALL-IN-ALL...THE PERIOD FEATURES CHANCE TO
OCCASIONALLY LIKELY POPS ACROSS THE MOUNTAINS...WITH MONDAY
NIGHT/TUESDAY APPEARING TO BE THE MOST THE LIKELY PERIOD FOR
RAINFALL OVERALL. THE SEVERE WEATHER THREAT APPEARS LOW...BUT
DEPENDING ON TIMING...AN ISOLATED STRONG TO SEVERE STORM COULD NOT
BE RULED OUT TUESDAY AFTERNOON/EVENING.
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THIS
PERIOD...ESPECIALLY MIN TEMPS. MAX TEMPS WILL ALSO REMAIN WELL
ABOVE NORMAL TUESDAY IN THE EAST...BUT SHOULD BE A TAD COOLER IN
THE WEST GIVEN GREATER CLOUD COVER. TEMPERATURES SHOULD TREND DOWN
A COUPLE OF DEGREES WEDNESDAY...BUT IT APPEARS WE WILL HAVE TO
WAIT UNTIL THU MORNING FOR ANY REAL DRYING OF THE AIR MASS AND
LOWERING OF THE DEWPOINTS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 PM EDT SUNDAY...
BROAD TROUGHING ACROSS THE NORTHEAST U.S. WILL DOMINATE THE
WEATHER AT THE BEGINNING OF THE PERIOD. THE FRONTAL
BOUNDARY/BAROCLINIC ZONE SHOULD BE LOCATED FROM THE MIDWEST INTO
THE SOUTHEAST STATES...HOPEFULLY SAFELY ENOUGH SOUTH OF OUR AREA
TO INHIBIT CONVECTION OF MUCH EXTENT. HOWEVER...WILL NEED TO WATCH
THU AS THERE IS YET ANOTHER UPSTREAM WAVE RIDING ALONG THE
BAROCLINIC ZONE THAT COULD BUCKLE THE BOUNDARY BACK FAR ENOUGH
NORTH TO ALLOW CONVECTION TO DRIFT BACK INTO THE SOUTHWEST PART OF
THE CWA...ESPECIALLY THE NW NC MOUNTAINS. THERE IS BETTER
PROBABILITY/CONFIDENCE THAT ONCE THIS FEATURE PASSES BY TO THE
SOUTH FRIDAY...WE WILL SEE GREATER POTENTIAL FOR THE FRONTAL
BOUNDARY TO DRIFT FURTHER SOUTH AND TAKE THE CONVECTION WITH IT. A
WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE
WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS
THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE
NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES
TO REACH THE REGION.
850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C
ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP
INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU
MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP
BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY
BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS
BY THE WEEKEND.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
AS OF 130 PM EDT SUNDAY...
MOST LOCATIONS ACROSS THE REGION WERE EXPERIENCING VFR
CONDITIONS...AND THAT WILL BE THE NORM THROUGH THE REMAINDER OF
THE AFTERNOON. HOWEVER...ISOLATED POCKETS OF BRIEF IFR/MVFR
CONDITIONS CAN BE UNDER THE SHOWERS AND THUNDERSTORMS THAT
OCCURRING ACROSS THE WESTERN PARTS OF THE AREA...AND THEN LATER
THIS AFTERNOON ACROSS THE ACTIVITY THAT IS EXPECTED ACROSS
PRIMARILY EASTERN AND SOUTHERN PARTS OF THE AREA.
THIS EVENING...THE SHOWER AND THUNDERSTORM ACTIVITY WILL
WANE...WITH PATCHY AREAS OF MVFR LIGHT FOG FORMING...ESPECIALLY IN
AREAS THAT EXPERIENCED...OR WILL EXPERIENCE...PRECIPITATION
THROUGH THE EARLY EVENING. ALSO...SOME PATCHY OF MVFR CIGS ARE
EXPECTED PRIMARILY OVER SOUTHEAST WEST VIRGINIA OVERNIGHT.
AFTER ROUGHLY 08Z/4AM...A THUNDERSTORM COMPLEX IS EXPECTED TO
PROGRESS INTO THE REGION FROM THE NORTHWEST. EXPECT AN INCREASE IN
SHOWERS AND STORMS WITH MORE LOCATIONS HAVING SUB-VFR CONDITIONS
THANKS TO THIS PRECIPITATION. THE CONVECTIVE ACTIVITY IS EXPECTED
TO PROGRESS EASTWARD THROUGH THE REGION AND BECOME MORE SCATTERED
IN NATURE DURING THE MORNING.
EXTENDED AVIATION DISCUSSION...
MONDAY AFTERNOON...ADDITIONAL CONVECTION MAY BE LACKING UNTIL
LATER IN THE DAY AFTER THERE IS ENOUGH TIME FOR THE ATMOSPHERE TO
DESTABILIZED IN THE WAKE OF THE STABLE LAYER BEHIND THE MORNING
CONVECTION.
MONDAY NIGHT...ANOTHER OCCURRENCE OF PATCHY LIGHT FOG AND STATUS
IS POSSIBLE IN ADVANCE OF YET ANOTHER THUNDERSTORM COMPLEX THAT
WILL CONVECTIVE ACTIVITY INTO AND THROUGH THE AREA DURING THE LATE
NIGHT/EARLY TUESDAY MORNING TIME PERIOD.
ADDITIONAL SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO LINGER
INTO TUESDAY AFTERNOON IN ASSOCIATION WITH A PASSING COLD FRONT.
MONDAY INTO TUESDAY...CONVECTION INCREASES AGAIN ACROSS THE AREA
WITH APPROACH AND PASSAGE OF A SHORTWAVE TROUGH AND ASSOCIATED
COLD FRONT. SUB- VFR CONDITIONS AGAIN WILL ACCOMPANY THE HEAVIER
CONVECTION MAINLY DURING THE AFTERNOON AND EVENING HOURS. PATCHY
LATE NIGHT/EARLY MORNING FOG/STRATUS AGAIN LIKELY ESPCLY IN AREAS
THAT SEE HEAVIER RAINFALL.
WEDNESDAY INTO THURSDAY OUR CHANCE OF PRECIPITATION WILL BE
LIMITED AT BEST AS HIGH PRESSURE TAKES CONTROL OF OUR WEATHER
PATTERN. DAYTIME VFR CONDITIONS ARE EXPECTED WITH PATCHY NIGHTTIME
MOUNTAIN AND RIVER VALLEY FOG DEVELOPMENT.
CONFIDENCE IN A PRECIPITATION-FREE FORECAST FOR FRIDAY IS NOT AS
HIGH. SOME GUIDANCE CONTINUES A DRY FORECAST...OTHERS HINT AT A
BACKDOOR COLD FRONT REACHING THE AREA WITH SOME ASSOCIATED
PRECIPITATION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...DS/WP
SHORT TERM...RAB
LONG TERM...RAB
AVIATION...DS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
623 PM CDT MON JUL 20 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 248 PM CDT MON JUL 20 2015
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED A DEEP TROUGH PLOWING INTO BRITISH COLUMBIA...
RIDGING OVER THE NORTHERN U.S. ROCKIES INTO ALBERTA /
SASKATCHEWAN...AND TROUGHING FROM NORTHERN ONTARIO INTO NORTHERN
MN. A SHORTWAVE WAS ALSO EVIDENT OVER EASTERN IOWA...WHICH
COMBINED WITH A SURGE OF 850MB MOISTURE TRANSPORT...MID LEVEL
FRONTOGENESIS AND PRECIPITABLE WATER AROUND 1.5 INCHES HELPED
BRING SHOWERS AND SOME THUNDERSTORMS TO THE SOUTHEAST HALF OF THE
FORECAST AREA THIS MORNING. A SURFACE COLD FRONT WAS ALSO MARCHING
THROUGH THE FORECAST AREA...NOW FROM GREEN BAY TO OELWEIN.
INSTABILITY HAS BEEN BEEN LIMITED DUE TO MORNING CLOUDS/SHOWERS...
BUT RAP MESOANALYSIS SUGGESTS UP TO 1000 J/KG OF MLCAPE EXISTS
ALONG THE FRONT. THIS INSTABILITY HAS RESULTED IN SOME ISOLATED
SHOWERS ALONG THE FRONT...WITH WEAK LOW LEVEL CONVERGENCE
PREVENTING MORE DEVELOPMENT. IN THE WAKE OF THE FRONT...
PRECIPITABLE WATER DROPS DOWN TO 0.75 INCHES...RESULTING IN DRYING
OF THE AIR INCLUDING AT THE SURFACE. HOWEVER...A FEW SHOWERS WERE
NOTED IN THE COLD POOL REGION UNDERNEATH THE TROUGH IN FAR
NORTHERN MN/ONTARIO. BREEZY CONDITIONS NOTED TOO BEHIND THE FRONT
WITH TIGHTER PRESSURE GRADIENT AND DAYTIME MIXING. THESE NORTHWEST
WINDS WERE DRIVING IN COLDER AIR...NOTED BY 850MB TEMPS OF 16-18C
AHEAD COMPARED TO 8-10C OVER NORTHERN MN. SURFACE RIDGE RESIDED
WELL TO THE WEST OVER THE WESTERN DAKOTAS.
ANY SHOWERS/STORMS THE DEVELOP ALONG THE COLD FRONT OVER THE
SOUTHEAST THIRD OF THE FORECAST AREA SHOULD EXIT BY 23/00Z AS THE
FRONT CONTINUES TO PUSH SOUTHEAST. AFTER THAT...COOLER...DRIER AIR
REMAINS ON TRACK TO DROP INTO THE REGION FOR TONIGHT AND MONDAY. THE
EXTENSION OF THE UPPER TROUGH IN NORTHERN MN LOOKS TO SWING ACROSS
ALL OF WI TONIGHT AND INTO THE EASTERN GREAT LAKES ON TUESDAY. THIS
UPPER TROUGH WILL HELP DRIVE 850MB TEMPS DOWN TO 10-11C BY 12Z TUE.
ANY OF THE SHOWERS ACCOMPANYING THE COLD POOL LOOK TO STAY WELL
NORTH AND DIMINISH WITH LOSS OF DAYTIME HEATING THIS EVENING. SKIES
WILL CLEAR OUT QUICKLY THIS EVENING AS DRY AIR INFILTRATES AND LOSS
OF DAYTIME HEATING DISSIPATES CUMULUS. IF NOT FOR A PERSISTENT
NORTHWEST BREEZE WE COULD SEE A DECENT VALLEY FOG EVENT.
NEVERTHELESS...THE MORE SHELTERED SMALLER VALLEYS LIKE THE WISCONSIN
WILL FOG. THE TYPICAL COLD SPOTS SHOULD ALSO RADIATE NICELY AND DIP
DOWN INTO THE UPPER 40S. THE REST OF THE REGION SHOULD SEE LOWS IN
THE 50S. PLENTY OF SUN ON TRACK FOR TUESDAY WITH DRY AIR IN PLACE
AND HIGH PRESSURE BUILDING IN. WITH 850MB TEMPS CLIMBING TO 12-14C
BY 00Z WEDNESDAY THANKS TO DEEP MIXING...HIGHS IN THE 70S SHOULD BE
COMMON WITH LOW 80S FOUND IN RIVER VALLEYS AND SANDY SOIL AREAS. THE
DEEP MIXING ALSO SHOULD PROMOTE IN QUITE A BIT LOWER DEWPOINTS
COMPARED TO TODAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 248 PM CDT MON JUL 20 2015
UPPER RIDGING SEEN OVER THE NORTHERN ROCKIES AND SASKATCHEWAN /
ALBERTA IS PROGGED TO GRADUALLY MOVE EAST INTO THE REGION OVER
THE NEXT FEW DAYS...MOVING OVERHEAD AROUND 12Z FRIDAY. SUBSIDENCE
WITH THIS UPPER RIDGING BUILDING IN...COMBINED WITH THE FRONT
TODAY PUSHING ALL THE MOISTURE SOUTH OF I-70 RESULT IN DRY
CONDITIONS FOR THE MOST PART THROUGH THURSDAY NIGHT.
HOWEVER...THERE IS A BAND OF MID LEVEL FRONTOGENESIS THAT LOOKS TO
SET UP LATE WEDNESDAY INTO THURSDAY...SITUATED FROM CENTRAL MN
INTO NORTH CENTRAL WI. THE 20.12Z NAM/ECMWF/CANADIAN HAVE BACKED
OFF ON THE INTENSITY AND THUS QPF PRODUCTION TO THE POINT OF
NEARLY DRY. ON THE OTHER HAND THE 20.12Z GFS STILL PRODUCES SOME
QPF. BELIEVE THE GFS MIGHT BE OVERLY MOIST...A KNOWN BIAS...AND
THEREFORE HAVE TRENDED DRY FOR TAYLOR/CLARK COUNTIES DURING MID-
WEEK. TEMPERATURES WEDNESDAY AND THURSDAY WILL BE ON A WARMING
TREND AS 850MB TEMPS EVENTUALLY CLIMB TO 14-16C BY 00Z FRI. MAY
HAVE TO CONTEND WITH VALLEY FOG TUESDAY NIGHT WITH LIGHT
WINDS...BUT THERE ARE HINTS OF SOME CLOUDS PASSING THROUGH.
THEREFORE...HAVE KEPT MUCH FOG OUT.
FOR FRIDAY THROUGH MONDAY...THE MAIN FEATURE OF INTEREST IS A
PORTION OF THE DEEP TROUGH IN BRITISH COLUMBIA THAT DROPS THROUGH
THE REGION LATE FRIDAY THROUGH SATURDAY EVENING. 20.12Z
GFS/ECMWF/CANADIAN ALL WANT TO DEVELOP CONVECTION IN WARM ADVECTION
AHEAD OF THE SHORTWAVE TROUGH...THEN ADDITIONAL CONVECTION AS THE
COLD FRONT ASSOCIATED WITH THE TROUGH COMES THROUGH. SOME TIMING
ISSUES THUS PRECIPITATION CHANCES ARE SPREAD OUT...THOUGH IF TRENDS
CONTINUE SHOULD BE ABLE TO PULL OUT CHANCES FOR SATURDAY NIGHT AND
EVEN SATURDAY AFTERNOON. IF THE GFS PANS OUT WE MIGHT HAVE TO DEAL
WITH SOME SEVERE STORMS...PARTICULARLY FRIDAY NIGHT...BUT THE ECMWF
WOULD KEEP ITS SEVERE THREAT FARTHER TO THE SOUTHWEST. SOMETHING TO
WATCH. DRIER WEATHER THEN FOLLOWS FOR SUNDAY AS UPPER AND SURFACE
RIDGING BEGINS BUILDING BACK IN. PERHAPS ANOTHER INTERESTING PERIOD
COULD SETUP SUNDAY NIGHT AND MONDAY...PARTICULARLY IN THE ECMWF...AS
A SHORTWAVE COMES DOWN THE RIDGE BUILDING IN. FOR NOW JUST HAVE SOME
LOW CHANCES ON MONDAY PER CONSENSUS BUT THESE MAY NEED ADJUSTMENT.
OVERALL TEMPERATURES LOOK TO STAY AT OR ABOVE SEASONABLE
NORMALS...AND SOME OF THE HIGHS IN THE CURRENT FORECAST ALTHOUGH
NEAR CONSENSUS COULD END UP BEING A LITTLE HIGHER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 623 PM CDT MON JUL 20 2015
A PERIOD OF GOOD VFR CONDITIONS EXPECTED TONIGHT THRU TUE AS DRIER
AND COOLER CANADIAN HIGH PRESSURE SETTLES INTO THE UPPER MIDWEST.
NORTHWEST WINDS WILL DIMINISH BY SUNSET...BUT REMAIN IN THE 5-8KT
RANGE OVERNIGHT...LIMITING ANY LATE NIGHT/EARLY MORNING BR POTENTIAL
AT SITES LIKE KLSE. THE DRIER BOUNDARY LAYER AIR MOVING IN WILL HELP
LIMIT THE BR AS WELL. FEW/SCT 5K-6K FT DIURNAL CUMULUS EXPECTED LATE
TUE MORNING THRU TUE AFTERNOON...ALONG WITH AN UPTICK OF THE
NORTHWEST WINDS WITH DEEPER DIURNAL MIXING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1224 PM MDT SUN JUL 19 2015
.UPDATE...
ISSUED AT 907 AM MDT SUN JUL 19 2015
MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY BUT THE COVERAGE
AND STRENGTH WILL BE LESS THAN YESTERDAY. BASED ON LATEST
RADAR...SATELLITE...AND NUMERICAL MODELS MOST PRECIPITATION WILL
OCCUR ALONG THE INTERSTATE 80 CORRIDOR FROM AROUND LARAMIE
EASTWARD INTO THE SOUTHERN NEBRASKA PANHANDLE. THE CHANCE FOR
SEVERE THUNDERSTORMS IS VERY LOW TODAY...IN FACT THE INSTABILITY
AXIS OVER THE WESTERN NEBRASKA PANHANDLE AT NOON WILL SLIDE EAST
INTO CENTRAL NEBRASKA BY EARLY THIS EVENING. THEREFORE WITH ONLY
MINIMAL CAPE OVER THE PANHANDEL AND EVEN LESS CAPE INTO SOUTHEAST
WYOMING...NOT ANTICIPATING SEVERE STORMS TODAY. ALSO A MID LEVEL
CLOUD DECK OVER THE SOUTHERN FORECAST AREA WILL FURTHER INHIBIT
DEEPER/STRONGER CONVECTION.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 239 AM MDT SUN JUL 19 2015
ISOLATED SHOWERS HAVE ENDED ACROSS SOUTHEAST WY AND THE WESTERN NE
PANHANDLE THIS AM. HOWEVER...THE BOUNDARY LAYER REMAINS VERY MOIST
WITH DEW POINTS IN THE 50S OVER MUCH OF THE PLAINS. CLEARING SKIES
HAVE ALLOWED FOR RADIATIONAL COOLING AND LOWERING T-TD SPREADS OVER
THE LAST FEW HOURS WITH LLVL RHS APPROACHING 100 PCT ALONG THE I80
CORRIDOR BETWEEN CYS-SNY AT 09Z. RECENT 11-3.9 MICROMETER SATELLITE
SHOWS LOW CLOUDS DEVELOPING EAST/SOUTHEAST OF THE CWA IN DEUEL AND
SEDGWICK COUNTIES IN NE/CO...AND THE LATEST HRRR SHOWS EXPANSION OF
STRATUS AND LOW VSBYS WESTWARD TOWARD CYS THROUGH 15Z. ADDED PATCHY
FOG EARLY IN THE PERIOD. SOME UNCERTAINTY WITH CONVECTIVE POTENTIAL
LATER ON TODAY WITH MIXED SIGNALS FROM AVAILABLE GUIDANCE. A FAIRLY
STRONG MID LEVEL SHORTWAVE WILL SWING ACROSS NORTHEAST WY/SOUTHWEST
SD THIS AFTN...FORCING A SURFACE TROUGH EAST ACROSS THE CWA. MODELS
ARE IN AGREEMENT WITH AN 80-100 KT 250 MILLIBAR JET OVERHEAD...SO
THINK THERE WILL BE MORE THAN ENOUGH FORCING. THE NAM SHOWS SBCAPE
BETWEEN 1500-2500 J/KG ALONG WITH MODEST EFFECTIVE SHEAR. COULD SEE
STRONGER STORMS TODAY...BUT HOW MANY IS A GOOD QUESTION. THE HRRR IS
DRY DESPITE FAVORABLE DYNAMICS...BUT THE NAM BREAKS OUT QPF IN THE
VICINITY OF LLVL CONVERGENCE AFTER 21Z. THE GFS CONTINUES TO BE OUR
WORST PERFORMING MODEL IN THE WORLD OF BLYR MOISTURE...SO CONTINUED
TO THROW OUT ITS QPF SOLUTIONS. GFS/ECMWF APPEAR TO HAVE COME INTO
BETTER AGREEMENT WITH ANOTHER MID LEVEL DISTURBANCE ON MON...ALONG
WITH A GOOD SHOT OF H7-H3 MOISTURE. WENT AHEAD AND ADDED SCHC POPS
BETWEEN 18Z MON AND 06Z TUE WITH UNCERTAIN TIMING...BUT IT IS GOOD
TO SEE BOTH MODELS FINALLY SHOWING A VORT MAX TRACKING ACROSS THE
STATE IN THE AFTN/EVE. A TYPICAL JULY PATTERN SHOULD CONTINUE THRU
TUES WITH MORE ENERGY EMBEDDED WITHIN THE FLOW. TEMPERATURES SHOULD
BE NEAR SEASONAL NORMS.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 330 AM MDT SUN JUL 19 2015
MEDIUM TO LONG RANGE MODELS CONTINUE TO SHOW A TYPICAL JULY
WEATHER PATTERN ACROSS THE WESTERN AND CENTRAL UNITED STATES.
VERY WARM TEMPERATURES ARE EXPECTED BY LATE NEXT WEEK AS AN UPPER
LEVEL HIGH CENTERED NEAR TEXAS EXPANDS NORTHWARD IN THE FORM OF A
RIDGE AXIS. WHAT IS UNCLEAR AT THIS TIME IS THUNDERSTORM CHANCES
EACH DAY. THE 00Z GFS CONTINUES TO BE WAY TOO DRY IN THE BOUNDARY
LAYER WITH DEW POINT VALUES AVERAGING 10 TO 15 DEGREES BELOW ALL
THE OTHER MODELS. THIS IS REFLECTED WELL IN LOCAL VERIFICATION AS
THE GFS40 AND EXTENDED GFS MOS CONTINUE TO UNDER-PERFORM WITH
FORECAST DEWPOINT TEMPERATURES. AS A RESULT...THE GFS IS TOO HOT
IN THE EXTENDED. THEREFORE...HAD TO MOSTLY DISCOUNT THE GFS
SOLUTION FOR THIS FORECAST PACKAGE. THE GEM AND ECMWF SHOW AT
LEAST A RISK OF ISOLATED THUNDERSTORMS ACROSS THE MOUNTAINS AND
HIGH PLAINS EACH DAY. THE BEST CHANCE FOR SHOWERS AND TSTORMS WILL
BE WEDNESDAY AS ALL MODELS SHOW A SHORTWAVE PUSHING EASTWARD
ACROSS THE AREA...SO KEPT POP BETWEEN 20 TO 35 PERCENT ACROSS MOST
OF THE AREA AND CLOSER TO 50 PERCENT IN THE MOUNTAINS. AFTER
THAT...CHANCES FOR TSTORMS WILL BE MUCH MORE ISOLATED AS THE RIDGE
AXIS AND UPPER LEVEL HIGH DOMINATE THE WEATHER PATTERN. THE ECMWF
STILL HINTS AT A FEW WEAK SHORTWAVES MOVING ACROSS THE AREA BY
NEXT WEEK AS THE UPPER LEVEL FLOW BECOMES SLIGHTLY MORE
NORTHWESTERLY. INCREASED POP BETWEEN 15 TO 20 PERCENT...MAINLY
EAST OF I25. HIGH TEMPERATURES WILL BE IN THE MID 80S TO LOW 90S
THURSDAY THROUGH SATURDAY...WARMEST OVER WESTERN NEBRASKA. THERE
IS ONE THING THE MODELS DO AGREE WELL ON...AND THAT IS THE LOW
POTENTIAL FOR SEVERE WEATHER THROUGH NEXT WEEKEND DUE TO MINIMAL
LOW TO MIDLEVEL SHEAR
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1223 PM MDT SUN JUL 19 2015
THE MAIN CHALLENGE THIS TAF CYCLE IS AGAIN IS THE TIMING AND
EXTENT OF THUNDERSTORM ACTIVITY THIS AFTERNOON AND EARLY EVENING
AS MOISTURE ASSOCIATED WITH AN UPPER-LEVEL DISTURBANCE MOVES
ACROSS THE AREA. CURRENT THINKING IS THAT THUNDERSTORMS WILL FIRE
ALONG THE SRN END OF THE CLOUD-DECK WHICH EXTENDS FROM KCYS TO
KSNY AFTER 20Z. COVERAGE AND STRENGTH WILL BE LESS THAN
YESTERDAY...BUT STILL ENOUGH TO WARRANT VCTS AT KCYS....KBFF AND
KSNY. THIS ACTIVITY WILL DISSIPATE WITH SUNSET.
&&
.FIRE WEATHER...
ISSUED AT 239 AM MDT SUN JUL 19 2015
NO FIRE WEATHER CONCERNS. AFTERNOON RELATIVE HUMIDITY VALUES SHOULD
STAY WELL ABOVE CRITICAL THRESHOLDS THROUGH MIDWEEK. WIND GUSTS TO
30 MPH ARE EXPECTED TODAY ALONG AND WEST OF THE LARAMIE RANGE...BUT
HUMIDITY VALUES ARE EXPECTED TO REMAIN AT OR ABOVE 20 PCT. A TROUGH
OF LOW PRESSURE WILL BRING A CHANCE FOR SHOWERS AND STORMS OVER THE
MOUNTAINS AND ADJACENT PLAINS THIS AFTN...LIKELY SPREADING INTO THE
NEBRASKA PANHANDLE IN THE EVE. A FEW STORMS COULD CONTAIN GUSTY AND
ERRATIC WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...CLH
LONG TERM...TJT
AVIATION...CAH
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
947 AM MDT SUN JUL 19 2015
.UPDATE...
ISSUED AT 907 AM MDT SUN JUL 19 2015
MORE SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY BUT THE COVERAGE
AND STRENGTH WILL BE LESS THAN YESTERDAY. BASED ON LATEST
RADAR...SATELLITE...AND NUMERICAL MODELS MOST PRECIPITATION WILL
OCCUR ALONG THE INTERSTATE 80 CORRIDOR FROM AROUND LARAMIE
EASTWARD INTO THE SOUTHERN NEBRASKA PANHANDLE. THE CHANCE FOR
SEVERE THUNDERSTORMS IS VERY LOW TODAY...IN FACT THE INSTABILITY
AXIS OVER THE WESTERN NEBRASKA PANHANDLE AT NOON WILL SLIDE EAST
INTO CENTRAL NEBRASKA BY EARLY THIS EVENING. THEREFORE WITH ONLY
MINIMAL CAPE OVER THE PANHANDEL AND EVEN LESS CAPE INTO SOUTHEAST
WYOMING...NOT ANTICIPATING SEVERE STORMS TODAY. ALSO A MID LEVEL
CLOUD DECK OVER THE SOUTHERN FORECAST AREA WILL FURTHER INHIBIT
DEEPER/STRONGER CONVECTION.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 239 AM MDT SUN JUL 19 2015
ISOLATED SHOWERS HAVE ENDED ACROSS SOUTHEAST WY AND THE WESTERN NE
PANHANDLE THIS AM. HOWEVER...THE BOUNDARY LAYER REMAINS VERY MOIST
WITH DEW POINTS IN THE 50S OVER MUCH OF THE PLAINS. CLEARING SKIES
HAVE ALLOWED FOR RADIATIONAL COOLING AND LOWERING T-TD SPREADS OVER
THE LAST FEW HOURS WITH LLVL RHS APPROACHING 100 PCT ALONG THE I80
CORRIDOR BETWEEN CYS-SNY AT 09Z. RECENT 11-3.9 MICROMETER SATELLITE
SHOWS LOW CLOUDS DEVELOPING EAST/SOUTHEAST OF THE CWA IN DEUEL AND
SEDGWICK COUNTIES IN NE/CO...AND THE LATEST HRRR SHOWS EXPANSION OF
STRATUS AND LOW VSBYS WESTWARD TOWARD CYS THROUGH 15Z. ADDED PATCHY
FOG EARLY IN THE PERIOD. SOME UNCERTAINTY WITH CONVECTIVE POTENTIAL
LATER ON TODAY WITH MIXED SIGNALS FROM AVAILABLE GUIDANCE. A FAIRLY
STRONG MID LEVEL SHORTWAVE WILL SWING ACROSS NORTHEAST WY/SOUTHWEST
SD THIS AFTN...FORCING A SURFACE TROUGH EAST ACROSS THE CWA. MODELS
ARE IN AGREEMENT WITH AN 80-100 KT 250 MILLIBAR JET OVERHEAD...SO
THINK THERE WILL BE MORE THAN ENOUGH FORCING. THE NAM SHOWS SBCAPE
BETWEEN 1500-2500 J/KG ALONG WITH MODEST EFFECTIVE SHEAR. COULD SEE
STRONGER STORMS TODAY...BUT HOW MANY IS A GOOD QUESTION. THE HRRR IS
DRY DESPITE FAVORABLE DYNAMICS...BUT THE NAM BREAKS OUT QPF IN THE
VICINITY OF LLVL CONVERGENCE AFTER 21Z. THE GFS CONTINUES TO BE OUR
WORST PERFORMING MODEL IN THE WORLD OF BLYR MOISTURE...SO CONTINUED
TO THROW OUT ITS QPF SOLUTIONS. GFS/ECMWF APPEAR TO HAVE COME INTO
BETTER AGREEMENT WITH ANOTHER MID LEVEL DISTURBANCE ON MON...ALONG
WITH A GOOD SHOT OF H7-H3 MOISTURE. WENT AHEAD AND ADDED SCHC POPS
BETWEEN 18Z MON AND 06Z TUE WITH UNCERTAIN TIMING...BUT IT IS GOOD
TO SEE BOTH MODELS FINALLY SHOWING A VORT MAX TRACKING ACROSS THE
STATE IN THE AFTN/EVE. A TYPICAL JULY PATTERN SHOULD CONTINUE THRU
TUES WITH MORE ENERGY EMBEDDED WITHIN THE FLOW. TEMPERATURES SHOULD
BE NEAR SEASONAL NORMS.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 330 AM MDT SUN JUL 19 2015
MEDIUM TO LONG RANGE MODELS CONTINUE TO SHOW A TYPICAL JULY
WEATHER PATTERN ACROSS THE WESTERN AND CENTRAL UNITED STATES.
VERY WARM TEMPERATURES ARE EXPECTED BY LATE NEXT WEEK AS AN UPPER
LEVEL HIGH CENTERED NEAR TEXAS EXPANDS NORTHWARD IN THE FORM OF A
RIDGE AXIS. WHAT IS UNCLEAR AT THIS TIME IS THUNDERSTORM CHANCES
EACH DAY. THE 00Z GFS CONTINUES TO BE WAY TOO DRY IN THE BOUNDARY
LAYER WITH DEW POINT VALUES AVERAGING 10 TO 15 DEGREES BELOW ALL
THE OTHER MODELS. THIS IS REFLECTED WELL IN LOCAL VERIFICATION AS
THE GFS40 AND EXTENDED GFS MOS CONTINUE TO UNDER-PERFORM WITH
FORECAST DEWPOINT TEMPERATURES. AS A RESULT...THE GFS IS TOO HOT
IN THE EXTENDED. THEREFORE...HAD TO MOSTLY DISCOUNT THE GFS
SOLUTION FOR THIS FORECAST PACKAGE. THE GEM AND ECMWF SHOW AT
LEAST A RISK OF ISOLATED THUNDERSTORMS ACROSS THE MOUNTAINS AND
HIGH PLAINS EACH DAY. THE BEST CHANCE FOR SHOWERS AND TSTORMS WILL
BE WEDNESDAY AS ALL MODELS SHOW A SHORTWAVE PUSHING EASTWARD
ACROSS THE AREA...SO KEPT POP BETWEEN 20 TO 35 PERCENT ACROSS MOST
OF THE AREA AND CLOSER TO 50 PERCENT IN THE MOUNTAINS. AFTER
THAT...CHANCES FOR TSTORMS WILL BE MUCH MORE ISOLATED AS THE RIDGE
AXIS AND UPPER LEVEL HIGH DOMINATE THE WEATHER PATTERN. THE ECMWF
STILL HINTS AT A FEW WEAK SHORTWAVES MOVING ACROSS THE AREA BY
NEXT WEEK AS THE UPPER LEVEL FLOW BECOMES SLIGHTLY MORE
NORTHWESTERLY. INCREASED POP BETWEEN 15 TO 20 PERCENT...MAINLY
EAST OF I25. HIGH TEMPERATURES WILL BE IN THE MID 80S TO LOW 90S
THURSDAY THROUGH SATURDAY...WARMEST OVER WESTERN NEBRASKA. THERE
IS ONE THING THE MODELS DO AGREE WELL ON...AND THAT IS THE LOW
POTENTIAL FOR SEVERE WEATHER THROUGH NEXT WEEKEND DUE TO MINIMAL
LOW TO MIDLEVEL SHEAR
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH SUNDAY NIGHT)
ISSUED AT 239 AM MDT SUN JUL 19 2015
VFR CONDITIONS CONTINUE EARLY THIS MORNING. HOWEVER...CAN NOT RULE
OUT SOME FOG AND LOW CIGS EAST OF THE LARAMIE RANGE. WILL CONTINUE
TO MONITOR THE DEVELOPMENT OF ANY LOW STRATUS...AND MAY HAVE TO
AMEND LOCATIONS EAST OF KCYS OVER THE NEXT FEW HOURS IF NOTHING
DEVELOPS. OTHERWISE...VFR CONDITIONS WILL PREVAIL INTO EARLY THIS
AFTERNOON. THERE IS SOME UNCERTAINTY OF TSTORM DEVELOPMENT THIS
AFTERNOON DUE TO MODEL DIFFERENCES...BUT WILL KEEP VCTS AT MOST
TERMINALS THIS AFTERNOON AND INTO THIS EVENING.
&&
.FIRE WEATHER...
ISSUED AT 239 AM MDT SUN JUL 19 2015
NO FIRE WEATHER CONCERNS. AFTERNOON RELATIVE HUMIDITY VALUES SHOULD
STAY WELL ABOVE CRITICAL THRESHOLDS THROUGH MIDWEEK. WIND GUSTS TO
30 MPH ARE EXPECTED TODAY ALONG AND WEST OF THE LARAMIE RANGE...BUT
HUMIDITY VALUES ARE EXPECTED TO REMAIN AT OR ABOVE 20 PCT. A TROUGH
OF LOW PRESSURE WILL BRING A CHANCE FOR SHOWERS AND STORMS OVER THE
MOUNTAINS AND ADJACENT PLAINS THIS AFTN...LIKELY SPREADING INTO THE
NEBRASKA PANHANDLE IN THE EVE. A FEW STORMS COULD CONTAIN GUSTY AND
ERRATIC WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...CLH
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
316 AM MDT SUN JUL 19 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 239 AM MDT SUN JUL 19 2015
ISOLATED SHOWERS HAVE ENDED ACROSS SOUTHEAST WY AND THE WESTERN NE
PANHANDLE THIS AM. HOWEVER...THE BOUNDARY LAYER REMAINS VERY MOIST
WITH DEW POINTS IN THE 50S OVER MUCH OF THE PLAINS. CLEARING SKIES
HAVE ALLOWED FOR RADIATIONAL COOLING AND LOWERING T-TD SPREADS OVER
THE LAST FEW HOURS WITH LLVL RHS APPROACHING 100 PCT ALONG THE I80
CORRIDOR BETWEEN CYS-SNY AT 09Z. RECENT 11-3.9 MICROMETER SATELLITE
SHOWS LOW CLOUDS DEVELOPING EAST/SOUTHEAST OF THE CWA IN DEUEL AND
SEDGWICK COUNTIES IN NE/CO...AND THE LATEST HRRR SHOWS EXPANSION OF
STRATUS AND LOW VSBYS WESTWARD TOWARD CYS THROUGH 15Z. ADDED PATCHY
FOG EARLY IN THE PERIOD. SOME UNCERTAINTY WITH CONVECTIVE POTENTIAL
LATER ON TODAY WITH MIXED SIGNALS FROM AVAILABLE GUIDANCE. A FAIRLY
STRONG MID LEVEL SHORTWAVE WILL SWING ACROSS NORTHEAST WY/SOUTHWEST
SD THIS AFTN...FORCING A SURFACE TROUGH EAST ACROSS THE CWA. MODELS
ARE IN AGREEMENT WITH AN 80-100 KT 250 MILLIBAR JET OVERHEAD...SO
THINK THERE WILL BE MORE THAN ENOUGH FORCING. THE NAM SHOWS SBCAPE
BETWEEN 1500-2500 J/KG ALONG WITH MODEST EFFECTIVE SHEAR. COULD SEE
STRONGER STORMS TODAY...BUT HOW MANY IS A GOOD QUESTION. THE HRRR IS
DRY DESPITE FAVORABLE DYNAMICS...BUT THE NAM BREAKS OUT QPF IN THE
VICINITY OF LLVL CONVERGENCE AFTER 21Z. THE GFS CONTINUES TO BE OUR
WORST PERFORMING MODEL IN THE WORLD OF BLYR MOISTURE...SO CONTINUED
TO THROW OUT ITS QPF SOLUTIONS. GFS/ECMWF APPEAR TO HAVE COME INTO
BETTER AGREEMENT WITH ANOTHER MID LEVEL DISTURBANCE ON MON...ALONG
WITH A GOOD SHOT OF H7-H3 MOISTURE. WENT AHEAD AND ADDED SCHC POPS
BETWEEN 18Z MON AND 06Z TUE WITH UNCERTAIN TIMING...BUT IT IS GOOD
TO SEE BOTH MODELS FINALLY SHOWING A VORT MAX TRACKING ACROSS THE
STATE IN THE AFTN/EVE. A TYPICAL JULY PATTERN SHOULD CONTINUE THRU
TUES WITH MORE ENERGY EMBEDDED WITHIN THE FLOW. TEMPERATURES SHOULD
BE NEAR SEASONAL NORMS.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 330 AM MDT SUN JUL 19 2015
MEDIUM TO LONG RANGE MODELS CONTINUE TO SHOW A TYPICAL JULY
WEATHER PATTERN ACROSS THE WESTERN AND CENTRAL UNITED STATES.
VERY WARM TEMPERATURES ARE EXPECTED BY LATE NEXT WEEK AS AN UPPER
LEVEL HIGH CENTERED NEAR TEXAS EXPANDS NORTHWARD IN THE FORM OF A
RIDGE AXIS. WHAT IS UNCLEAR AT THIS TIME IS THUNDERSTORM CHANCES
EACH DAY. THE 00Z GFS CONTINUES TO BE WAY TOO DRY IN THE BOUNDARY
LAYER WITH DEW POINT VALUES AVERAGING 10 TO 15 DEGREES BELOW ALL
THE OTHER MODELS. THIS IS REFLECTED WELL IN LOCAL VERIFICATION AS
THE GFS40 AND EXTENDED GFS MOS CONTINUE TO UNDER-PERFORM WITH
FORECAST DEWPOINT TEMPERATURES. AS A RESULT...THE GFS IS TOO HOT
IN THE EXTENDED. THEREFORE...HAD TO MOSTLY DISCOUNT THE GFS
SOLUTION FOR THIS FORECAST PACKAGE. THE GEM AND ECMWF SHOW AT
LEAST A RISK OF ISOLATED THUNDERSTORMS ACROSS THE MOUNTAINS AND
HIGH PLAINS EACH DAY. THE BEST CHANCE FOR SHOWERS AND TSTORMS WILL
BE WEDNESDAY AS ALL MODELS SHOW A SHORTWAVE PUSHING EASTWARD
ACROSS THE AREA...SO KEPT POP BETWEEN 20 TO 35 PERCENT ACROSS MOST
OF THE AREA AND CLOSER TO 50 PERCENT IN THE MOUNTAINS. AFTER
THAT...CHANCES FOR TSTORMS WILL BE MUCH MORE ISOLATED AS THE RIDGE
AXIS AND UPPER LEVEL HIGH DOMINATE THE WEATHER PATTERN. THE ECMWF
STILL HINTS AT A FEW WEAK SHORTWAVES MOVING ACROSS THE AREA BY
NEXT WEEK AS THE UPPER LEVEL FLOW BECOMES SLIGHTLY MORE
NORTHWESTERLY. INCREASED POP BETWEEN 15 TO 20 PERCENT...MAINLY
EAST OF I25. HIGH TEMPERATURES WILL BE IN THE MID 80S TO LOW 90S
THURSDAY THROUGH SATURDAY...WARMEST OVER WESTERN NEBRASKA. THERE
IS ONE THING THE MODELS DO AGREE WELL ON...AND THAT IS THE LOW
POTENTIAL FOR SEVERE WEATHER THROUGH NEXT WEEKEND DUE TO MINIMAL
LOW TO MIDLEVEL SHEAR
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH SUNDAY NIGHT)
ISSUED AT 239 AM MDT SUN JUL 19 2015
VFR CONDITIONS CONTINUE EARLY THIS MORNING. HOWEVER...CAN NOT RULE
OUT SOME FOG AND LOW CIGS EAST OF THE LARAMIE RANGE. WILL CONTINUE
TO MONITOR THE DEVELOPMENT OF ANY LOW STRATUS...AND MAY HAVE TO
AMEND LOCATIONS EAST OF KCYS OVER THE NEXT FEW HOURS IF NOTHING
DEVELOPS. OTHERWISE...VFR CONDITIONS WILL PREVAIL INTO EARLY THIS
AFTERNOON. THERE IS SOME UNCERTAINTY OF TSTORM DEVELOPMENT THIS
AFTERNOON DUE TO MODEL DIFFERENCES...BUT WILL KEEP VCTS AT MOST
TERMINALS THIS AFTERNOON AND INTO THIS EVENING.
&&
.FIRE WEATHER...
ISSUED AT 239 AM MDT SUN JUL 19 2015
NO FIRE WEATHER CONCERNS. AFTERNOON RELATIVE HUMIDITY VALUES SHOULD
STAY WELL ABOVE CRITICAL THRESHOLDS THROUGH MIDWEEK. WIND GUSTS TO
30 MPH ARE EXPECTED TODAY ALONG AND WEST OF THE LARAMIE RANGE...BUT
HUMIDITY VALUES ARE EXPECTED TO REMAIN AT OR ABOVE 20 PCT. A TROUGH
OF LOW PRESSURE WILL BRING A CHANCE FOR SHOWERS AND STORMS OVER THE
MOUNTAINS AND ADJACENT PLAINS THIS AFTN...LIKELY SPREADING INTO THE
NEBRASKA PANHANDLE IN THE EVE. A FEW STORMS COULD CONTAIN GUSTY AND
ERRATIC WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLH
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
1245 AM CDT TUE JUL 21 2015
.AVIATION...
LINE OF TSRA MOVING INTO CENTRAL ARKANSAS...BUT SLOWLY WEAKENING.
CURRENT THINKING IS THAT THIS LINE WILL DISSIPATE WITH ANOTHER
WAVE MOVING ALONG THE FRONT DURING THE AFTERNOON TUESDAY. THERE
MAY BE SOME TSRA ACROSS THE NORTH AROUND SUNRISE. VFR CONDITIONS
WILL PREVAIL EXCEPT NEAR TSRA.
&&
.PREV DISCUSSION... /ISSUED 953 PM CDT MON JUL 20 2015/
UPDATE...
UPDATE TO THE FORECAST TO REFLECT CURRENT RADAR TRENDS. THIS
EVENING...HAVE CONTINUED TO SEE ISOLATED STORMS DEVELOP AHEAD OF
THE FRONT STRETCHING FROM BATESVILLE TO WALDRON. HRRR HAS THESE
THUNDERSTORMS CONTINUING TO PUSH SOUTH AND EAST THROUGH THE NIGHT
AS THEY WEAKEN. WITH THE SLOW MOVING FRONT REMAINING IN THE AREA
AGAIN ON TUESDAY...ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL
BE POSSIBLE AGAIN ON TUESDAY.
PREV DISCUSSION... /ISSUED 258 PM CDT MON JUL 20 2015/
SHORT TERM...TONIGHT THROUGH THURSDAY
HIGH PRESSURE OVER THE AREA WILL MOVE SLIGHTLY WESTWARD TONIGHT
AND TUESDAY. THIS IS GOING TO ALLOW A COLD FRONT TO MOVE INTO
ARKANSAS FROM MISSOURI. THIS FRONT WILL SLOWLY WORK SOUTH THROUGH
WEDNESDAY AND STALL IN SOUTH ARKANSAS WEDNESDAY. RAIN CHANCES WILL
INCREASE ALONG AND NEAR THIS FRONT THROUGH THURSDAY. SOME
THUNDERSTORMS WILL BE CAPABLE OF PRODUCING HEAVY RAINFALL DUE TO
ABUNDANT MOISTURE AVAILABLE.
THE HEAT ADVISORY WILL EXPIRE EARLY THIS EVENING. TEMPERATURES THE
NEXT FEW DAYS WILL BE A FEW DEGREES COOLER DUE TO CLOUD COVER AND
RAIN CHANCES...SO HEAT INDICES WILL BE LOWER.
LONG TERM...FRIDAY THROUGH MONDAY
AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL CONTINUE TO DOMINATE THE
AREA THROUGH THE EXTENDED TERM...WITH THE RIDGE CENTERED OVER THE
SOUTHERN PLAINS THROUGHOUT THE PERIOD. AS THE RIDGE SLIPS A BIT
WESTWARD...IT MAY ALLOW FOR SOME ISOLATED AFTERNOON AND EVENING
THUNDERSTORMS TO DEVELOP...ESPECIALLY ACROSS THE NERN ZONES.
OTHERWISE IT WILL REMAIN QUITE HOT...WITH AFTERNOON TEMPERATURES
TOPPING OUT IN THE UPPER 90S TO AROUND 100 ACROSS MUCH OF THE
STATE.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...58
AREA FORECAST DISCUSSION
NWS TUCSON AZ
250 AM MST TUE JUL 21 2015
.SYNOPSIS...A DRYING TREND WILL PUSH THE BEST CHANCES OF
THUNDERSTORMS EAST AND SOUTH OF TUCSON THROUGH MID WEEK. A SOUTHERLY
TO SOUTHEASTERLY FLOW SHOULD RETURN MOISTURE TO THE AREA WEDNESDAY
NIGHT INTO THURSDAY. A SLIGHT DOWN SWING IN ACTIVITY IS EXPECTED
OVER THE WEEKEND...BEFORE PICKING BACK UP AGAIN EARLY NEXT WEEK.
EVEN SO...SHOWERS AND STORMS SHOULD BE CONFINED TO AREAS MAINLY
BETWEEN TUCSON AND THE NEW MEXICO BORDER EACH DAY.
&&
.DISCUSSION...WATER VAPOR IMAGERY AND 21/00Z UPPER-AIR PLOTS SHOW A
RIDGE CENTERED OVER THE SOUTHERN PLAINS...WITH A TROUGH AXIS
EXTENDING FROM NORTHERN UTAH ACROSS NEVADA....CENTRAL CALIFORNIA AND
INTO THE PACIFIC WATERS. A LARGE SWATH OF MID TO UPPER LEVEL DRY AIR
CAN BE SEEN COVERING MUCH OF THE EASTERN PACIFIC...SOUTHERN
CALIFORNIA...NORTHERN BAJA AND INTO MUCH OF ARIZONA. IR SATELLITE
IMAGERY SHOWS CLOUDINESS MOSTLY TO OUR EAST OVER MUCH OF NEW
MEXICO...NORTHERN MEXICO AND WEST TEXAS. THE ONLY CLOUDINESS OVER
ARIZONA AT THIS TIME RESIDES OVER THE EXTREME SOUTHEAST CORNER OF
THE STATE...SPECIFICALLY THE SOUTHEASTERN HALF OF COCHISE COUNTY.
YESTERDAY AFTERNOON THE 21/00Z KTWC SOUNDING REVEALED A PW OF 1.49
INCHES...WITH A LIFTED INDEX OF MINUS 3 AND A MU CAPE OF AROUND 800
J/KG. SINCE THAT TIME THE SWATH OF DRY AIR HAS MOVED EVEN FARTHER TO
THE NORTHEAST...SPREADING INTO SRN UTAH AND THE FOUR CORNERS REGION.
HOWEVER...THE INTERFACE BETWEEN THIS DRY AIR AND THE MOIST AIR TO
OUR EAST LIES ALONG A LINE GENERALLY FROM AROUND NOGALES TO SAFFORD
AND INTO WEST CENTRAL NEW MEXICO. THIS LINE OF DEMARCATION BETWEEN
THE DRY AND MOIST AIR SERVES AS A BATTLE ZONE FOR CONVECTION TO
DEVELOP. CURRENT PRECIPITABLE WATER VALUES FROM VARIOUS SOURCES
INDICATE THAT VALUES (FOR TUCSON) RANGE FROM AROUND 1.0 -1.25
INCHES. MODELS SHOW PW`S CONTINUING TO DECREASE A BIT MORE THIS
AFTERNOON...WITH READINGS EXPECTED TO BE RIGHT AROUND...OR SLIGHTLY
ABOVE THE 1 INCH MARK...WITH READINGS WELL BELOW 1 INCH OVER THE FAR
WESTERN DESERTS OF PIMA COUNTY. MODELS INDICATE THAT THESE VALUES
WILL CREEP BACK UP LATE WEDNESDAY AND INTO THURSDAY...WITH READINGS
RANGING FROM 1.4 - 1.8 INCHES AS SOUTHERLY FLOW TRANSPORTS MOISTURE
NORTHWARD.
FOR THIS AFTERNOON...HIGH RESOLUTION MODELS SUCH AS THE U OF A
WRF/NAM & GFS...AND THE HRRR SHOW VERY LITTLE ACTIVITY DEVELOPING
OVER MY FORECAST AREA TODAY. WHAT DOES DEVELOP SHOULD BE ALONG THE
AFOREMENTIONED DRY/MOIST AIR INTERFACE...WHICH AT THE PRESENT TIME
LIES OVER THE EXTREME EASTERN PART OF MY FORECAST AREA. I INHERITED
ISOLATED TO LOW END SCATTERED POP FOR MAINLY SANTA CRUZ AND SOUTHERN
COCHISE COUNTIES AND ALSO THE WHITE MOUNTAINS OF NORTHERN GRAHAM AND
GREENLEE COUNTIES. WE CAN REEVALUATE THIS IN THE MORNING WHEN THE
12Z SOUNDING ARRIVES...BUT FOR NOW THIS LOOKS REASONABLE.
DURING THE MIDDLE OF THE WEEK THE MODELS KEEP THE HIGH QUASI-
STATIONARY OVER THE SOUTHERN PLAINS...WITH THE PACIFIC TROUGH TO OUR
NORTHWEST. DISTURBANCES MOVING UP TO THE NORTH ON THE WESTERN FLANK
OF THE HIGH ARE EXPECTED TO INCREASE RAIN CHANCES A BIT AS THE
MOISTURE PLUME ON THE WEST SIDE OF THE HIGH IS EXPECTED TO MOVE
ACROSS EASTERN PARTS OF ARIZONA AND A LARGE PART OF NEW MEXICO. MOS
NUMBERS INDICATE THAT THE NAM IS THE WETTEST...WHILE THE ECMWF IS
THE DRIEST. HOWEVER...THE NAM/GFS/ECMWF ALL POINT TO AN UPSWING IN
ACTIVITY WEDNESDAY NIGHT INTO THURSDAY. I DID MAKE ADJUSTMENTS TO
THE POP FORECAST TO ACCOUNT FOR THIS...SO FOR NOW I SHOW LOW END
CHANCES FOR AREAS MAINLY FROM TUCSON TO NOGALES TO DOUGLAS TO
WILLCOX...AS WELL AS CHANCE POPS OVER THE WHITES. OVER THE FAR
WESTERN DESERTS ONLY `SILENT` SINGLE DIGIT POPS FOR WEDNESDAY NIGHT
INTO THURSDAY.
BY LATE IN THE WEEK THE MODELS INDICATE THAT THE TROUGH AXIS OVER
NORTHERN CALIFORNIA WILL MOVE TO A POSITION OVER THE CENTRAL PORTION
OF THE STATE. IN RESPONSE TO THIS...MOISTURE IS PROGGED TO BE
SHUNTED EAST AND SOUTH OF THIS AREA FOR A SLIGHT DECREASE IN
THUNDERSTORM ACTIVITY DURING THE LATTER PART OF THE WEEK AND INTO
THE WEEKEND. BY EARLY NEXT WEEK A MAJOR TROUGH MAKES ITS WAY INTO
THE PACIFIC NORTHWEST WITH THE RIDGE STILL OVER THE CENTRAL AND
SOUTHERN PLAINS...BUT WITH MODELS ADVERTISING AN INVERTED TROUGH
ROUNDING THE SOUTHERN PERIPHERY OF THE HIGH AND SLIDING WEST OR
NORTHWEST ACROSS NORTHERN MEXICO. THIS SHOULD RESULT IN AN INCREASE
FOR SHOWERS AND THUNDERSTORMS DURING THE EARLY PART OF NEXT WEEK.
FOR TUCSON...HIGH TEMPS WILL GENERALLY BE A DEGREE OR TWO EITHER
SIDE OF NORMAL TODAY THROUGH FRIDAY...THEN 3 TO 5 DEGS ABOVE NORMAL
THEREAFTER. LOWS WILL BE ABOUT 3 TO 5 DEGS ABOVE NORMAL EACH
MORNING...ALTHOUGH THE WARMEST MORNINGS WILL LIKELY OCCUR SUNDAY AND
MONDAY.
&&
.AVIATION...VALID THRU 22/12Z.
ISOLATED TO SCATTERED TSRA/SHRA MAINLY EAST AND SOUTH OF KTUS AND
ESP NEAR TERRAIN AFT 21/18Z. BRIEF MVFR CIGS/VSBYS AND GUSTS TO 35
KTS PSBL TIL 22/03Z IN AND AROUND THE STRONGER TSRA. EXPECT FEW-SCT
CLOUDS AT 8-10K FT WITH MORE COVERAGE DURING THE AFTERNOON/EVENING
HOURS. SFC WINDS DIURNALLY DRIVEN AND GENERALLY LESS THAN 12 KTS
OUTSIDE OF ANY TSRA/SHRA. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...WARM TEMPERATURES AND A SLIGHTLY DRIER AIRMASS WILL
LIMIT CONVECTION TO AREAS MAINLY EAST AND SOUTH OF TUCSON THROUGH
WEDNESDAY. SOME MOISTURE WILL ATTEMPT TO RETURN TO THE AREA AS EARLY
AS THURSDAY...BUT ESPECIALLY FROM FRIDAY ONWARD. THIS WILL BRING
BACK AN INCREASED CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE
COMING WEEKEND...BUT ESPECIALLY BY EARLY NEXT WEEK. TERRAIN-DRIVEN
20-FT WINDS WILL GENERALLY BE LESS THAN 15 MPH EXCEPT FOR SOME
OCCASIONAL AFTERNOON GUSTINESS DUE TO DAYTIME HEATING. A FEW OF THE
STRONGER THUNDERSTORMS MAY PRODUCE WIND GUSTS TO AROUND 40 MPH.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MOLLERE
AVIATION/FIRE WEATHER...FRENCH
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1123 PM MDT MON JUL 20 2015
.UPDATE...
ISSUED AT 627 PM MDT MON JUL 20 2015
UPDATED TO ADJUST POPS PER LATEST RADAR AND OBS AS WELL AS
HIGH RES MODEL DATA. ROSE
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 243 PM MDT MON JUL 20 2015
CURRENTLY...A HEALTHY AMOUNT OF CLOUD COVER THROUGH MUCH OF THE DAY
HAS PUT A DAMPER ON MUCH OF THE POTENTIAL ACTIVITY FOR TODAY...AND
CONVECTION CURRENTLY OVER THE HIGHER TERRAIN WAS SLOW TO START. NO
REPORTS OF HEAVY RAINFALL AS OF YET...AS SOUNDINGS THIS MORNING
CONFIRMED THAT THE GREATER AMOUNT OF MOISTURE IS AVAILABLE IN NM.
TEMPS HAVE WARMED INTO THE UPPER 70S TO UPPER 80S ACROSS THE PLAINS
AS OF 3 PM...AND IN THE 60S AND 70S FOR THE HIGH VALLEYS. SFC WINDS
ACROSS THE PLAINS HAVE BEEN GENERALLY OUR OF THE EAST...BUT WITHIN
THE PAST COUPLE OF HOURS HAVE SHIFTED TO A MORE S-SE DIRECTION.
TONIGHT...A FLAT RIDGE OF HIGH PRESSURE OVER THE SOUTHERN U.S. WILL
STAY THAT WAY FOR ANOTHER DAY OR SO...AS A COUPLE OF UPPER
DISTURBANCES CROSS THE GREAT BASIN AND NORTHERN ROCKIES. HI RES
MODELS INCLUDING THE HRRR INDICATE THAT THE CURRENT ACTIVITY WILL
CONTINUE WELL INTO THE NIGHT...WITH SOME SPILL OVER ACROSS THE I25
CORRIDOR THIS EVENING BETWEEN 22Z AND 06Z. OTHERWISE...FEEL THAT
ACTIVITY WILL BE MAINLY TIED TO THE MTS. SO...NOT A LOT OF
IMPRESSIVE STORMS JUST YET AND THE UPPER W-SW FLOW HAS BEEN KEEPING
STORMS MOVING...CUTTING DOWN ON THE FLASH FLOOD THREAT. PRECIPITABLE
WATER AMOUNTS SOUTH OF THE STATE LINE IN NM ARE WELL OVER AN
INCH...BUT UP NORTH IN THE PUB CWA ARE CLOSER TO .6 TO .7 OF AN
INCH. OF COURSE...THE THREAT OF FLASH FLOODING FOR AREA BURN SCARS
REMAINS THIS EVE AND WILL HAVE TO BE MONITORED.
TOMORROW...THE ACTIVE PATTERN CONTINUES AS A SHORTWAVE CROSSES
WY...PROVIDING THE TRIGGER FOR A RAPID INCREASE IN CONVECTION OVER
ALL OF THE MTS AND ADJACENT PLAINS BY 15Z. AS THIS WAVE CONTINUE
EAST...THE BAND OF ENHANCED LIFT WILL CROSS THE I25 CORRIDOR AND E
PLAINS THROUGH THE AFTN HRS...AND AN ATTEMPT HAS BEEN MADE IN THE
POP GRIDS TO SHOW THIS. STRONG TO SEVERE STORMS WILL ALSO BE A
POSSIBILITY TOMORROW AFTN AS THIS WAVE CROSSES THE AREA...AS THERE
WILL BE PLENTY OF MOISTURE AND SHEAR ON TAP...AND SPC HAS PAINTED
MUCH OF THE E PLAINS IN THE MARGINAL AREA. MAX TEMPS TOMORROW MAY BE
A DEGREE OR TWO COOLER...BUT SHOULD STILL WARM INTO THE 70S AND 80S
FOR THE PLAINS...60S AND 70S FOR THE HIGH VALLEYS. MOORE
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 243 PM MDT MON JUL 20 2015
TUESDAY NIGHT...
AN AREA OF SHOWERS AND STORMS WILL LIKELY BE MOVING ACROSS THE
EASTERN PLAINS AS A DISTURBANCE OVER THE REGION CONTINUES TO MOVE
EAST. LOCALLY HEAVY RAIN WILL BE POSSIBLE AND STRONG TO MARGINALLY
SVR STORMS WILL BE POSSIBLE GIVEN THE MODEST CAPE AND SHEAR THAT
WILL BE OVER THE PLAINS.
WEDNESDAY THROUGH FRIDAY...
OVERALL IT WILL BE DRY AND WARM AS MONSOON TAP WILL BE DECREASED
AS HEIGHTS RISE ACROSS THE REGION. MAX TEMPS OVER THE PLAINS WILL
RISE BACK UP INTO THE 90S. WE WILL STILL SEE SOME ISOLD TSRA
ACROSS THE REGION...BUT OVERALL COVERAGE WILL BE LESS THAN THE
LAST FEW DAYS.
SATURDAY INTO MONDAY..
GUIDANCE INDICATES MONSOON MOISTURE WILL ONCE AGAIN BE ON THE
UPSWING AS SW FLOW CONTINUES ALOFT AND A TROUGH TO OUR WEST MOVES
TOWARDS THE REGION. TEMPS WILL COOL SLIGHTLY AND SHOWERS AND
STORMS SHOULD INCREASE DURING THE AFTERNOON AND EVENING TIME
PERIODS. /HODANISH
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1116 PM MDT MON JUL 20 2015
MAIN CONCERNS WILL BE LOW CIG POTENTIAL OVER THE NEXT 24
HOURS...PARTICULARLY AT KCOS. WIDESPREAD PRECIP IS EXPECTED AS AN
UPPER LEVEL SYSTEM MOVES THROUGH IN COINCIDENCE WITH THE MONSOONAL
PATTERN OVER SE CO. COULD SEE A PERIOD OF MVFR CIGS AND POSSIBLY
BRIEF IFR CONDITIONS OVER THE SERN PLAINS LATE TONIGHT THROUGH
THE FIRST HALF OF TUE MORNING. PARTIAL CLEARING WILL BE POSSIBLE
LATE IN THE MORNING AND EARLY AFTERNOON. THE CONCERN THEN SHIFTS
TO THE POTENTIAL FOR TS ALONG WITH HEAVY RAIN...HAIL...AND GUSTY
WINDS IN THE MID-LATE AFTERNOON THROUGH EARLY EVENING. SHOWERS AND
STORMS WILL SLOWLY TRANSLATE EASTWARD INTO KS TUE EVENING.
DEPENDING ON THE EXTENT OF PRECIP DURING THE DAY AND
EVENING...COULD THEN SEE A PERIOD OF IFR CIGS AND/OR VIS TUE NIGHT
INTO WED MORNING OVER THE ERN PLAINS. KALS SHOULD STAY VFR BUT
COULD SEE SOME BRIEF RESTRICTIONS DUE TO ISOLD SHOWERS OR
STORMS...ESPECIALLY LATE TUE MORNING THROUGH AFTERNOON. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ROSE
SHORT TERM...MOORE
LONG TERM...HODANISH
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS ALBANY NY
128 AM EDT TUE JUL 21 2015
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE REGION TODAY...BRINGING A
CHANCE FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD
FROM CENTRAL CANADA INTO THE UPPER GREAT PLAINS WEDNESDAY...AND
DRIFT INTO THE GREAT LAKES AND OHIO VALLEY BY WEEKS END. IT WILL
USHER IN A COOLER AND LESS HUMID AIR MASS INTO THE REGION FOR THE
REST OF THE WEEK. AT THE SAME TIME A LARGE WEATHER DISTURBANCE
ALOFT WILL DROP FROM QUEBEC INTO THE MARITIMES WEDNESDAY INTO
FRIDAY...WITH INCREASING CLOUDS AND SHOWERS...MAINLY NORTH OF I90.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1025 PM...MAINLY JUST HIGH CLOUDS ACROSS THE ALBANY
FORECAST AREA AT THIS TIME. SOME LOWER CLOUDS ACROSS THE EXTREME
SOUTH AS COLD FRONT/DEWPOINT BOUNDARY APPEARS TO HAVE HUNG UP JUST
SOUTH OF POUGHKEEPSIE. THERE WERE A FEW SHOWERS VCNTY OF
POUGHKEEPSIE AN HOUR AGO...BUT RADAR SHOWS THEY HAVE DISSIPATED.
SHOWERS ASSOCIATED WITH COLD FRONT TO NORTHWEST ARE STILL NORTH
AND WEST OF TORONTO. LATEST HRRR HAS NOTHING BUT A FEW SPRINKLES
THROUGH 12Z SO NOT EXPECTING MUCH CHANGE THROUGH THE OVERNIGHT.
THIS CDFNT WILL REACH LK ERI-ST LAWRENCE VLY BY MORNING...FOLLOWED
BY A 500 HPA SHORT WV...AND CROSS THE FCA DURING THE DAY TUES. TD
CLOSE TO 60 AND ONLY 400-800 J/KG CAPE...BEST LI -4 TO -6 WITH
FOCUS ALONG W PERIPHERY OF FCA...ONLY SCT NON SEVERE TSTMS AND
-SHRA ARE EXPECTED. SPC HAS AREA IN GEN TSTMS..NO SVR THREAT.
OTRW TUES WILL BE A WARM DAY WITH HIGHS IN THE 80S AND A FEW NR
90 IN THE SOUTH...AS WELL AS SCT- BKN CU AHEAD OF THE CDFNT...CLOUDS
WITH ITS PASSAGE AND CLEARING IN ITS WAKE. TUES EVNG THE CDFNT
WILL PUSH S OF FCA AND 500HPA TROF MOVES ACROSS NY/NEW ENG OVRNT.
SCT -SHRA/TSTMS WILL END IN THE EVNG SE.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/.....
GENERALLY AGREEMENT AMONG THE MDL SUITE THROUGH THIS PERIOD AS WX
PATTERN OVER E NA WILL BE DOMINATED BY A 500 HPA TROF CUT OFF
OVER QB...THAT DIVES SE INTO THE MARITIMES BY FRI. INITIALLY SFC
HIGH PRESSURE BUILDS FM CENTRAL CANADA INTO THE UPPER GRT PLAINS
WED...AS TUES SFC LOW AND CDFNT DEPART OFFSHORE.
BY WED AFTN COOLING ALOFT AS 500HPA TEMPS FALL TO -13C TO -16C AND
JETS MOVING AROUND BASE OF 500HPA CUT OFF SAGGING SOUTH INTO FCA
BEGIN TO IMPACT RGN WITH VARYING DEGREES OF CLOUDS AND SCT MAINLY
DIURNALLY DRIVEN -SHRA N TIER AND OVER HIR TRRN. WOULDN`T RULE
OUT SOME GRAUPAL IN THESE -SHRA OVER HIR TRRN. THE NAM IS MORE
AGGRESSIVE WITH THIS PATTERN INTO THE FCA BY WED AFTN...THE GFS
HOLDING OFF TILL THU. BUT THE TREND IS STILL THE SAME.
AT THE SAME TIME IN RESPONSE TO THE DIVING 500 HPA TROF...SFC LOW
PRESSURE OVER MARITIMES DEEPENS...AND WIND GRADIENT INCRG OVR RGN
ESPECIALLY IN THE AFTN...RESULTING IN BREEZY CONDS AT TIMES.
SO OVERALL A PERIOD OF PC TO AT TIMES MC SKIES N WITH SCT SHRA
EACH DAY...DIURNALLY DRIVEN. GENERALLY MS SOUTH OF I90. TEMPS WILL
BE 3-5 DEG BLO NORMALS...WITH VERY COMFORTABLE RH LEVELS AS TD
FALL TO THE UPPER 40S AND 50S. FRIDAY NIGHT 500 HPA TROF FINALLY
SLIDES OFFSHORE AS SFC HIGH SETTLES OVER NE USA INTO QB.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
THIS FALL-LIKE AIRMASS...SLIGHTLY BELOW TEMPERATURES AND
COMFORTABLE HUMIDITY LEVELS...WILL CONTINUE INTO SATURDAY AS AN
AREA OF HIGH PRESSURE RIDGES ACROSS THE REGION. SATURDAY LOOKS TO
BE THE NICEST DAY OF THE LONG TERM PERIOD WITH DRY WEATHER AND
PARTLY CLOUDY SKIES.
DRY WEATHER LOOKS TO CONTINUE INTO SATURDAY NIGHT...WHILE AN UPPER-
LEVEL SHORTWAVE TROUGH APPROACHES FROM THE GREAT LAKES REGION. LONG
RANGE GUIDANCE IS HAVING SOME DIFFICULTY RESOLVING THIS SHORTWAVE
WITH IT BEING SO FAR OUT IN TIME...SO HAVE GONE WITH SLIGHT CHANCE
AND CHANCE POPS IN THE FORECAST FOR SUNDAY AND INTO MONDAY.
HIGH TEMPERATURES THROUGHOUT THE LONG TERM PERIOD WILL GENERALLY
CONTINUE 3 TO 5 DEG BLO NORMALS.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
MAINLY VFR CONDITIONS THROUGH THE 24 HOUR TAF CYCLE WITH TWO
PERIODS WHERE MVFR CONDITIONS MAY DEVELOP FOR A SHORT TIME. AFTER
ABOUT 09Z TONIGHT...SOME LOWER VISIBILITIES AND SCATTERED CLOUDS
BELOW 1000 FEET MAY DEVELOP AT KGFL AND KPSF AND HAVE PLACED VSBYS
AT 3SM IN THEIR RESPECTIVE TAFS. LATER TUESDAY AFTERNOON...
SHOWERS AND THUNDERSTORMS ARE EXPECTED AHEAD OF A COLD FRONT. FOR
NOW JUST VCSH IN TAFS BUT WE WILL MONITOR FOR IFR CONDITIONS AND
LIGHTNING.
WEST TO NORTHWEST WINDS AT AROUND 10 KTS BECOMING LIGHT AND
VARIABLE TO NEAR CALM TONIGHT. WINDS WILL BECOME SOUTH TO
SOUTHWEST AT 5 TO 10 KTS TUESDAY.
OUTLOOK...
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...FG...TSRA.
WEDNESDAY THROUGH SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
HIGH PRESSURE WILL BUILD ACROSS THE REGION THIS AFTERNOON AND SLIDE
OFFSHORE TONIGHT. A STRONGER COLD FRONT WILL CROSS THE REGION ON
TUESDAY...BRINGING CHANCES FOR SHOWERS AND THUNDERSTORMS. HIGH
PRESSURE WILL BUILD FROM CANADA INTO THE GREAT LAKES
WEDNESDAY...USHERING IN A COOLER AND DRIER AIR MASS INTO THE
REGION FOR MID WEEK TO LATE WEEK.
RELATIVE HUMIDITY VALUES WILL INCREASE TO MAXIMUM VALUES OF 80 TO
100 PERCENT TONIGHT AND TUESDAY NIGHT. MINIMUM VALUES TUESDAY
AFTERNOON WILL BE 35 TO 65 PERCENT...AND 35 TO 55 PERCENT
WEDNESDAY AFTERNOON.
WINDS WILL BE LIGHT TONIGHT...AND BECOME SOUTHWEST AND INCREASE
TO AROUND 10 TO 15 MPH TUESDAY. TUESDAY NIGHT THEY WILL BECOME
WEST AROUND 5 MPH AND INCREASE TO 10 TO 15 MPH WEDNESDAY.
&&
.HYDROLOGY...
MAINLY DRY CONDITIONS ARE EXPECTED THROUGH THE WEEK WITH THE
EXCEPTION OF SCATTERED SHOWERS AND THUNDERSTORMS TUESDAY
ASSOCIATED WITH A COLD FRONT. SOME LOCALLY HEAVY RAINFALL WILL BE
POSSIBLE IN ANY STRONGER STORMS...WITH PONDING OF WATER IN URBAN
AND POOR DRAINAGE LOCATIONS.
MAINLY DRY WEATHER IS THEN EXPECTED FROM WEDNESDAY THROUGH FRIDAY
EXCEPT FOR A FEW LIGHT SHOWERS ACROSS PORTIONS OF THE ADIRONDACKS
EACH DAY.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...SND/SNYDER
SHORT TERM...SNYDER
LONG TERM...IRL
AVIATION...SND/11
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER/JPV
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
340 AM EDT TUE JUL 21 2015
.DISCUSSION...
TODAY AND TONIGHT...LTST REGIONAL ANALYSIS SHOWS NO SIG CHG IN
MAP FEATURES SINCE THE WEEKEND WITH PRESENCE OF A Q/S BOUNDARY IN
PLACE ALONG THE MID ATLC SEABOARD TO THE NRN GULF COAST. LTST 915
MHZ PROFILER WINDS @ XMR HAVE SHOWN A LAYERED INCREASE IN SPEEDS
FROM THE SFC THROUGH THE MID LEVELS AS THE TAIL END OF SOME MID
LEVEL ENERGY TRANSITS NORTH OF THE STATE.
THE SETUP FOR TODAY REMAINS ANOTHER ROUND OF SCT STORMS ONCE SFC
HEATING AND BOUNDARY DEVELOPMENT COMMENCES. PWAT VALUES NR 2
INCHES COUPLED WITH SW STEERING WL ONCE AGAIN FAVOR THE I-4
CORRIDOR FOR INITIAL STORM ACTIVITY WITH INCRSG COVERAGE TOWARD
THE E CST AFTER INTERACTION WITH BOUNDARIES. LTST HRRR GUID SHOWS
A RATHER EARLY DEVELOPMENT OF THE INITIAL ACTIVITY BEFORE NOON
NEAR LAKE/VOLUSIA COS. WL KEEP A MODEST N-S GRADIENT OF POP
COVERAGE WITH SCT MENTION MOST ALL AREAS. THE ONLY INHIBITING
FACTOR REMAINS MID LEVEL TEMPS AROUND -6C (WHICH IS ABOUT 1-2C
WARMER THAN NORMAL). STORMS WL LARGELY COME TO AN END FROM 9-10 PM
WHILE SHIFTING OVER THE ATLC WATERS AND DISSIPATING.
WED-SAT...DIGGING 500MB TROUGH OVER THE EASTERN PACIFIC AND U.S.
WEST COAST BUILDS THE 500MB RIDGE OVER THE NATIONS CENTER FROM
AROUND A 5900 METER RIDGE WED TO A 5950 METER RIDGE FRI. THE
BUILDING RIDGE ALSO DEEPENS THE TROUGHING PATTERN OVER THE SOUTHEAST
STATES AND FLORIDA DURING THE SAME TIME PERIOD. THE DEEPENING
TROUGHING ALSO HELPS TO PUSH A FRONTAL BOUNDARY/TROUGH AND THE
MOISTURE POOLING AHEAD OF IT SOUTHWARD OVER THE SOUTHEAST STATES AND
COMING TO A STOP OVER THE SOUTHERN SECTION OF CENTRAL FLORIDA AND
SOUTH FLORIDA BY SUN. THIS MODEL RUNS DEPICTION OF THE MOISTURE
RIBBON ASSOCIATED WITH THE BOUNDARY LOOKS TO BE WIDER AND HIGHER
MOISTURE VALUES TOPPING 2 INCHES OF PRECIPITABLE WATER BOTH FRI AND
SAT. IF IT WERE NOT FOR LIGHT UPPER LEVEL/JET STREAM LEVEL WINDS AND
WEAK DISTURBANCES MOVING THROUGH THE 500MB FLOW RAIN CHANCES WOULD
MOST LIKELY BE HIGHER THAN THEIR MAS OF 50-60 PERCENT ON FRI. HIGHS
MAINLY AROUND 90 AT THE COAST AND LOW 90S INTERIOR. LOWS GENERALLY
IN THE MID 70S WITH UPPER 70S RIGHT AT THE COAST SOUTHERN BREVARD
SOUTH.
SUN-MON...SOME RELIEF FROM THE PERSISTENT SOUTHWEST TO WEST WIND
PATTERN AS THE FRONT IS FORECAST TO HAVE PUSHED INTO SOUTH FLORIDA
AND WEAK HIGH PRESSURE STRETCHING ALONG THE U.S. EAST COAST AND
WESTERN ATLANTIC BUILDS ACROSS NORTH FLORIDA AND INTO THE NORTHEAST
GULF OF MEXICO. THE RESULTING NORTHEAST TO EAST WIND FLOW BRINGS IN
A MORE STABLE...YET STILL MOIST...AIR MASS TO EAST CENTRAL FLORIDA.
THE WEATHER PATTERNS SHIFT TO THE MORE TYPICAL ONSHORE/EASTERLY
PATTERN. MORNING SHOWERS AT THE COAST TRANSITIONING TO STORMS FOR
THE INTERIOR. TEMPERATURES FALLING BACK TO THE MID AND UPPER 80S AT
THE COAST AND LOW 90S INLAND DUE TO EARLIER SEA BREEZES PUSHING WEST
OVER EAST CENTRAL FLORIDA.
&&
.AVIATION...
VFR CONDS THROUGH 21/15Z WITH ISOLD SHRA/TS WITH MVFR MOVING EWD
FROM THE FL GULF CST AFFECTING KLEE THEN SPREADING EWD WHILE
INCREASING IN CVG OVER REMAINDER OF SITES FM 21/17Z-21/22Z.
&&
.MARINE...PRESENCE OF A LITTLE TIGHTER GRADIENT OF OFFSHORE
COMPONENT WL DELAY OR ONSHORE BREEZE DEVELOPMENT. SEAS AOB 2FT
NEARSHORE AND 2-3FT OFFSHORE. SCT SHRAS/TSRAS MVG OFFSHORE FROM
AROUND 3 PM THROUGH SUNSET.
WED-SAT...WEST TO SOUTHWEST WINDS THROUGH THE PERIOD WITH SOME
INCREASE IN THE PRESSURE GRADIENT BY THU-FRI WHICH WILL DELAY SEA
BREEZE FORMATION EVEN MORE...AND POSSIBLY PROHIBIT FORMATION EVEN
ALONG THE TREASURE COAST. PRIMARY CONCERN FOR BOATERS WILL BE
OFFSHORE MOVING STORMS PRODUCING GUSTY WINDS AND LIGHTNING AS WELL
AS A FASTER STORM MOTION LATE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 92 76 93 76 / 50 30 40 30
MCO 92 76 93 76 / 50 20 40 20
MLB 93 76 94 76 / 40 30 30 20
VRB 93 75 94 75 / 30 30 30 20
LEE 90 78 91 78 / 60 20 50 30
SFB 93 78 92 78 / 50 20 50 30
ORL 93 78 93 77 / 50 20 50 20
FPR 94 74 94 75 / 30 30 30 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...PENDERGRAST
LONG TERM....WIMMER
AREA FORECAST DISCUSSION
NWS LINCOLN IL
318 AM CDT TUE JUL 21 2015
.SHORT TERM...(TODAY)
ISSUED AT 318 AM CDT TUE JUL 21 2015
FRONTAL BOUNDARY LYING ACROSS SOUTHEAST ILLINOIS THIS MORNING WITH
MOST OF THE DEEP CONVECTION SOUTH OF THIS FEATURE WITH A SECONDARY
BOUNDARY NOTED ON THE LATEST SURFACE ANALYSIS EXTENDING ACROSS THE
ILLINOIS RIVER VALLEY. SOME BROKEN CLOUDS ASSOCIATED WITH THE
SECONDARY BOUNDARY BUT HAVE NOT SEEN ANY PRECIP ASSOCIATED WITH THE
BAND OF CLOUDS. SOME PATCHY FOG HAS DEVELOPED OVER PARTS OF EAST
CENTRAL ILLINOIS OVER THE PAST SEVERAL HOURS AND WILL SEE THAT
GRADUALLY SHIFT INTO SOUTH CENTRAL THROUGH SOUTHEAST ILLINOIS EARLY
THIS MORNING AS DRIER AIR ADVECTS SOUTHEAST INTO THE FORECAST AREA.
OUR WEATHER TODAY WILL FEATURE PLEASANTLY WARM TEMPERATURES AND
LOWER HUMIDITY LEVELS AS HIGH PRESSURE SETTLES IN FROM THE NORTHWEST
THIS AFTERNOON. FORECAST SOUNDINGS OFF THE GFS SUGGEST WE SHOULD MIX
DOWN FROM ABOUT 850 MB THIS AFTERNOON WHICH WOULD GIVE US HIGHS IN
THE 80 TO 84 DEGREE RANGE, WHILE THE RAP SOUNDINGS WERE MUCH MORE
AGGRESSIVE WITH MIXING HEIGHTS YIELDING HIGHS IN THE MID TO EVEN
UPPER 80S IN OUR SOUTHEAST COUNTIES. THINK THE CURRENT RAP MAY BE
UNDERPLAYING THE COOL ADVECTION FILTERING IN FROM THE NORTHWEST SO
WILL SIDE WITH THE MORE CONSERVATIVE GFS SOLUTION AND TEMPERATURES
FOR THIS AFTERNOON.
&&
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 318 AM CDT TUE JUL 21 2015
HIGH PRESSURE BUILDING BACK INTO THE REGION FOR THE SHORT TERM
BRINGING A DRIER FORECAST AND A LESS MUGGY AIRMASS. TEMPS JUST
BELOW NORMAL FOR THE NEXT TWO DAYS BEHIND TODAYS COLD FRONT. WIDE
UPPER RIDGE OVER THE SOUTHERN THIRD OF THE CONUS STARTING TO AMPLIFY
A BIT TOWARDS THE END OF THE WEEK. MIDWEST GETTING INTO THE RIDGE
WITH LITTLE FLOW ALOFT AS A QUICK IMPULSE RIPPLES OVER THE RIDGE AND
DIVES INTO THE MID MISS RIVER VALLEY WED NIGHT AND INTO THURSDAY.
FOR NOW, THE FORECAST IS DRY, BUT THE NAM IS SHOWING SIGNS OF A
SLIGHTLY DIFFERENT TRACK JUST TO THE NE AND INTO ILX/S SW. SLIGHTS
WILL REMAIN IN THE FORECAST FOR THU/THU NIGHT.
AS THE UPPER RIDGE BUILDS ACROSS THE MIDDLE OF THE CONUS WITH THE
AXIS DRIFTING OVER THE MIDWEST, A WARMING TREND RETURNS FOR THE END
OF THE WEEK AND INTO THE WEEKEND. POOL OF HEAT OVER THE DESERT SW
SLOWLY ENCROACHING ON THE MIDWEST WITH 850MB TEMPS REACHING 20-23C
BY SATURDAY AFTERNOON AS THE RIDGE AMPLIFIES. MIXED DOWN, TEMPS AT
THE SFC SET TO MAX INTO THE MID TO UPPER 80S, SLIGHTLY ABOVE
CLIMATOLOGY, AS WELL AS SLIGHTLY ABOVE THE MAJORITY OF THE
GUIDANCE...AND HAVE ADJUSTED THE FORECAST IN THAT DIRECTION.
CONCERNED ABOUT THE FORECAST THROUGH THE WEEKEND WITH REGARDS TO THE
PRECIPITATION. UNDER THE EXPANSIVE RIDGE, MODELS ARE NOT HANDLING
SMALL IMPULSES WITH ANY KIND OF CONTINUITY OR CONSENSUS. SLIGHTS
AND LOW CHANCE POPS DOMINATE THE SUPERBLEND AS A RESULT THROUGH THE
WEEKEND AND INTO THE FIRST PART OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1150 PM CDT MON JUL 20 2015
A NARROW LINE OF CLOUDS MOVING SOUTH INTO THE AREA DID HAVE SOME
SHOWERS IN THEM EARLIER TONIGHT. BELIEVE THIS STILL POSSIBLE
DURING THE OVERNIGHT HOURS FOR ABOUT 2-3HRS SO WILL KEEP VCSH IN
TAFS TO START. BELIEVE THIS IS A REFLECTION OF A WEAK FRONT AND
OBSERVATIONAL DATA SHOWS A DEFINITE WIND SHIFT ONCE FRONT GOES
THROUGH. RELATIVELY DRIER AIR SHOULD MOVE INTO THE AREA BEHIND THE
FRONT...BUT BELIEVE SOME LIGHT FOG STILL POSSIBLE AT ALL SITES
REMAINDER OF THE NIGHT. ONCE FOG DISSIPATES IN THE MORNING
SCATTERED CU WILL STILL BE POSSIBLE AT ALL SITES. ANY CU WILL BE
DIURNAL AND DISSIPATE AFTER 00Z. WINDS WILL BE LIGHT AND VARIABLE
EVEN AFTER WEAK FROPA IN COUPLE OF HOURS. THEN NORTHERLY WINDS ARE
EXPECTED REMAINDER OF THE FORECAST PERIOD.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
249 AM CDT TUE JUL 21 2015
.SHORT TERM...
230 PM CDT
THROUGH TONIGHT...
A SHORT WAVE TROUGH AXIS ORIENTED FROM SOUTHWEST WISCONSIN THROUGH
FAR WESTERN ILLINOIS AS OF 230 PM WILL MOVE OVER THE FORECAST
AREA LATE THIS AFTERNOON. A PATCH OF CLEARING HAS ALLOWED
TEMPERATURES TO REACH MID 80S WITH A FEW UPPER 80S ATTAINED IN
EASTERN AREAS. THESE ARE AT CONVECTIVE VALUES GIVEN THE DEW POINTS
AND ACCORDINGLY SOME CUMULUS...A FEW TOWERING...HAVE DEVELOPED IN
THE AREA. LAPSE RATES ABOVE THE LFC REMAIN NON-IMPRESSIVE PER
AMDAR AND RAP ANALYSIS SO WHILE SOME SHOWERS MAY DEVELOP/INCREASE
IN COVERAGE WITH THIS IMPULSE AS IT MOVES EAST...THUNDER MAY STILL
BE HARD TO COME BY.
A SURFACE COLD FRONT EXTENDING FROM A LOW AT THE SOUTHERN TIP OF
JAMES BAY IN CANADA WILL MOVE SOUTHEAST THROUGH THE AREA THIS
EVENING...BASICALLY RIGHT IN THE WAKE OF THE AFOREMENTIONED SHORT
WAVE TROUGH. THE AIR MASS AHEAD OF THE FRONT IN WISCONSIN TO
EASTERN IOWA HAS STRUGGLED TO DESTABILIZE GIVEN CLOUD COVER...BUT
A FEW STORMS ARE STARTING TO POP AS THAT MOVES EAST. SCATTERED
SHOWERS AND A FEW STORMS SHOULD DEVELOP IMMEDIATELY UPSTREAM AND
SOME ARE ANTICIPATED TO PROGRESS INTO THE CWA BETWEEN 6 AND 9 PM.
COVERAGE SHOULD REMAIN SCATTERED. AS NOTED EARLIER...THE SOMEWHAT
LIMITED INSTABILITY SHOULD KEEP COVERAGE 30-50 PERCENT ALONG THE
BOUNDARY. WHILE SOME 35 MPH PLUS GUSTS MAY ACCOMPANY A FEW STORMS
GIVEN MARGINAL EFFECTIVE DEEP LAYER SHEAR AND 700-1000 J/KG OF
DCAPE...THE ATMOSPHERE REMAINS NON-CONDUCIVE FOR SEVERE STORMS.
THE FOCUS FOR SHOWERS SHOULD CLEAR THE CWA BY MIDNIGHT WITH
CLOUDS QUICKLY CLEARING AS WELL. A SECONDARY MOMENTUM PUSH OF THE
DRIER AIR MASS SHOULD ARRIVE LATE ON NORTHERLY WINDS...WITH LOW
TEMPERATURES BY DAYBREAK NEAR NORMAL.
MTF
&&
.LONG TERM...
328 PM CDT
TUESDAY THROUGH MONDAY...
NO SIGNIFICANT WEATHER CONCERNS FOR ONE OF THE FEW TIMES THIS
METEOROLOGICAL SUMMER. SURFACE HIGH PRESSURE REMAINING NEARLY
STATIONARY OVER THE REGION SHOULD KEEP THINGS DRY THROUGH
FRIDAY. EXPECTING DAILY LAKE BREEZE FORMATION THROUGH AT LEAST
THURSDAY. 12Z NAM DID HAVE A FEW PERIODS WITH CONVECTION FORECAST
TO POP ON LAKE BREEZE...WEDNESDAY EVENING AND THURSDAY
AFTERNOON...THOUGH DEWPOINTS SEEM TO BE HIGH BIASED EVEN WITH VERY
WET SUMMER SO FAR. THUS THINKING IS INSTABILITY WILL REMAIN
MINIMAL EVEN WITH A FEW UPPER DISTURBANCES MOVING OVER THE AREA
LATE WEDNESDAY AND AGAIN ON THURSDAY...COUPLING WITH DRY COLUMN TO
ENABLE DRY CONDITIONS TO PREVAIL. CANNOT COMPLETELY RULE OUT A
FEW ISOLATED SHOWERS BEING SQUEEZED OUT ON THURSDAY GIVEN STRONGER
VORT MAX.
TEMPERATURES ON TUESDAY SHOULD REACH AROUND 80 INLAND
BASED ON 925 MB TEMPS IN THE UPPER TEENS CELSIUS AND FAIRLY DEEP
MIXING. THEN EXPECT GRADUAL WARMING THE REST OF THE WEEK INTO THE
WEEKEND DUE TO RISING HEIGHTS FROM SOUTHERN CONUS MID/UPPER RIDGE.
GUIDANCE HAS OFTEN VERIFIED TOO HIGH THIS SUMMER WITH TEMPS...BUT
WONDER IF PROGGED THERMAL PROFILES MAY BE SUPPORTIVE OF A BIT
WARMER THAN FORECAST LOWER 80S ON WEDNESDAY AND THURSDAY AND LOWER
TO MID 80S ON FRIDAY SINCE THERE WILL LIKELY NOT BE CONVECTIVE
DEBRIS CLOUD COVER TO CONTEND WITH. DOES APPEAR A BIT BETTER
CHANCE FOR MID AND HIGH CLOUDS ON THURSDAY THOUGH AFTER A FEW TO
SCT CU ON WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE NORTHWEST
ON FRIDAY NIGHT AND THEN MOVE ACROSS THE AREA ON
SATURDAY...BRINGING A THREAT FOR SHOWERS AND THUNDERSTORMS.
THERE IS UNCERTAINTY ON TIMING...COVERAGE AND INTENSITY THIS FAR
OUT AND THEN WITH OVERALL PATTERN EVOLUTION BEYOND SATURDAY
EVENING FRONT. STILL APPEARS IT WILL GENERALLY BE LESS ACTIVE THAN
WHAT WE HAVE SEEN MUCH OF THIS SUMMER AND SEASONABLY WARM.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NORTHWEST WINDS SHIFTING TO NORTH ARND 10 KT OVERNIGHT.
* WINDS SHIFTING TO NELY LESS THAN 10KT BY LATE MORNING.
KREIN
//DISCUSSION...UPDATED 06Z...
A COLD FRONT EXTENDING FROM SRN LOWER MICHIGAN ACROSS THE SRN END
OF LAKE MICHIGAN INTO NRN IL WILL CONTINUE TO PUSH SOUTH THROUGH
THE NIGHT. FOLLOWING THE PASSAGE OF THE FRONT...WINDS ACROSS THE
REGION WILL SHIFT TO NLY...ARND 10KT INLAND AND A LITTLE STRONGER
NEAR LAKE MICHIGAN. WINDS AT MDW/GYY SHOULD INCREASE TO 12-18KT
FOR A SHORT TIME.
AS HIGH PRESSURE BUILDS ACROSS THE REGION BEHIND THE FRONT...THE
PRESSURE GRADIENT WILL WEAKEN AND WIND SPEEDS SHOULD DIMINISH. THE
COMBINATION OF THE SLACK PRESSURE GRADIENT AND DIFFERENTIAL LAND-
WATER HEATING SHOULD ALLOW A LAKE BREEZE TO DEVELOP. THE LATEST
HIGH RES MODEL GUIDANCE SUGGESTS THAT THE LAKE BREEZE SET UP INVOF
ORD/MDW BY LATE MORNING...WITH WINDS BECMG NNELY BY LATE MORNING
AND THEN VEERING MORE NELY-ENELY THROUGH THE DAY. WINDS SHOULD BE
LESS THAN 10 KT BEHIND THE LAKE BREEZE. THE BOUNDARY IS NOT
EXPECTED TO REACH DPA/RFD AND WINDS THERE BACK NWLY THROUGH THE
DAY TOMORROW. AT GYY...WINDS SHOULD REMAIN A BIT STRONGER AND
NNELY THROUGH THE DAY. BY TOMORROW EVENING...THE LAKE BREEZE
SHOULD WASH OUT AND WINDS SHOULD BECM LGT/VRBL AS THE CENTER OF
THE HIGH PRESSURE CROSSES THE REGION.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE IN WIND TRENDS WITH RESPECT TO LAKE BREEZE
DETAILS...OTRW HIGH CONFIDENCE IN WIND TRENDS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. LIGHT WEST WINDS TURNING EAST WITH LAKE BREEZE IN
THE AFTERNOON.
THURSDAY...VFR. LIGHT SOUTH WINDS TURNING EAST-SOUTHEAST WITH LAKE
INFLUENCE IN THE AFTERNOON.
FRIDAY...VFR SOUTH WINDS.
SATURDAY...VFR. CHANCE TSRA. SOUTHWEST WINDS.
SUNDAY...VFR. WESTERLY WINDS.
MDB
&&
.MARINE...
245 AM CDT
A COLD FRONT IS PUSHING SOUTH OF THE LAKE LATE TONIGHT. A SURGE OF
COOLER AIR BEHIND THE FRONT WILL BRIEFLY INCREASE NLY WINDS OVER
THE SRN TIP OF THE LAKE TO 15-25 KT BEFORE DIMINISHING LATER THIS
MORNING. HIGH PRESSURE IS THEN EXPECTED TO MOVE OVER THE LAKE
LATER TO DAY AND TONIGHT...REMAINING THE DOMINANT FEATURE OVER THE
GREAT LAKES THROUGH LATE THIS WEEK. FOLLOWING THE BRIEF PERIOD OF
BRISK WINDS THIS MORNING...CONDITIONS SHOULD BE RATHER QUIET OVER
THE LAKE FOR THE REST OF THE WEEK.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1246 AM CDT TUE JUL 21 2015
.SHORT TERM...
230 PM CDT
THROUGH TONIGHT...
A SHORT WAVE TROUGH AXIS ORIENTED FROM SOUTHWEST WISCONSIN THROUGH
FAR WESTERN ILLINOIS AS OF 230 PM WILL MOVE OVER THE FORECAST
AREA LATE THIS AFTERNOON. A PATCH OF CLEARING HAS ALLOWED
TEMPERATURES TO REACH MID 80S WITH A FEW UPPER 80S ATTAINED IN
EASTERN AREAS. THESE ARE AT CONVECTIVE VALUES GIVEN THE DEW POINTS
AND ACCORDINGLY SOME CUMULUS...A FEW TOWERING...HAVE DEVELOPED IN
THE AREA. LAPSE RATES ABOVE THE LFC REMAIN NON-IMPRESSIVE PER
AMDAR AND RAP ANALYSIS SO WHILE SOME SHOWERS MAY DEVELOP/INCREASE
IN COVERAGE WITH THIS IMPULSE AS IT MOVES EAST...THUNDER MAY STILL
BE HARD TO COME BY.
A SURFACE COLD FRONT EXTENDING FROM A LOW AT THE SOUTHERN TIP OF
JAMES BAY IN CANADA WILL MOVE SOUTHEAST THROUGH THE AREA THIS
EVENING...BASICALLY RIGHT IN THE WAKE OF THE AFOREMENTIONED SHORT
WAVE TROUGH. THE AIR MASS AHEAD OF THE FRONT IN WISCONSIN TO
EASTERN IOWA HAS STRUGGLED TO DESTABILIZE GIVEN CLOUD COVER...BUT
A FEW STORMS ARE STARTING TO POP AS THAT MOVES EAST. SCATTERED
SHOWERS AND A FEW STORMS SHOULD DEVELOP IMMEDIATELY UPSTREAM AND
SOME ARE ANTICIPATED TO PROGRESS INTO THE CWA BETWEEN 6 AND 9 PM.
COVERAGE SHOULD REMAIN SCATTERED. AS NOTED EARLIER...THE SOMEWHAT
LIMITED INSTABILITY SHOULD KEEP COVERAGE 30-50 PERCENT ALONG THE
BOUNDARY. WHILE SOME 35 MPH PLUS GUSTS MAY ACCOMPANY A FEW STORMS
GIVEN MARGINAL EFFECTIVE DEEP LAYER SHEAR AND 700-1000 J/KG OF
DCAPE...THE ATMOSPHERE REMAINS NON-CONDUCIVE FOR SEVERE STORMS.
THE FOCUS FOR SHOWERS SHOULD CLEAR THE CWA BY MIDNIGHT WITH
CLOUDS QUICKLY CLEARING AS WELL. A SECONDARY MOMENTUM PUSH OF THE
DRIER AIR MASS SHOULD ARRIVE LATE ON NORTHERLY WINDS...WITH LOW
TEMPERATURES BY DAYBREAK NEAR NORMAL.
MTF
&&
.LONG TERM...
328 PM CDT
TUESDAY THROUGH MONDAY...
NO SIGNIFICANT WEATHER CONCERNS FOR ONE OF THE FEW TIMES THIS
METEOROLOGICAL SUMMER. SURFACE HIGH PRESSURE REMAINING NEARLY
STATIONARY OVER THE REGION SHOULD KEEP THINGS DRY THROUGH
FRIDAY. EXPECTING DAILY LAKE BREEZE FORMATION THROUGH AT LEAST
THURSDAY. 12Z NAM DID HAVE A FEW PERIODS WITH CONVECTION FORECAST
TO POP ON LAKE BREEZE...WEDNESDAY EVENING AND THURSDAY
AFTERNOON...THOUGH DEWPOINTS SEEM TO BE HIGH BIASED EVEN WITH VERY
WET SUMMER SO FAR. THUS THINKING IS INSTABILITY WILL REMAIN
MINIMAL EVEN WITH A FEW UPPER DISTURBANCES MOVING OVER THE AREA
LATE WEDNESDAY AND AGAIN ON THURSDAY...COUPLING WITH DRY COLUMN TO
ENABLE DRY CONDITIONS TO PREVAIL. CANNOT COMPLETELY RULE OUT A
FEW ISOLATED SHOWERS BEING SQUEEZED OUT ON THURSDAY GIVEN STRONGER
VORT MAX.
TEMPERATURES ON TUESDAY SHOULD REACH AROUND 80 INLAND
BASED ON 925 MB TEMPS IN THE UPPER TEENS CELSIUS AND FAIRLY DEEP
MIXING. THEN EXPECT GRADUAL WARMING THE REST OF THE WEEK INTO THE
WEEKEND DUE TO RISING HEIGHTS FROM SOUTHERN CONUS MID/UPPER RIDGE.
GUIDANCE HAS OFTEN VERIFIED TOO HIGH THIS SUMMER WITH TEMPS...BUT
WONDER IF PROGGED THERMAL PROFILES MAY BE SUPPORTIVE OF A BIT
WARMER THAN FORECAST LOWER 80S ON WEDNESDAY AND THURSDAY AND LOWER
TO MID 80S ON FRIDAY SINCE THERE WILL LIKELY NOT BE CONVECTIVE
DEBRIS CLOUD COVER TO CONTEND WITH. DOES APPEAR A BIT BETTER
CHANCE FOR MID AND HIGH CLOUDS ON THURSDAY THOUGH AFTER A FEW TO
SCT CU ON WEDNESDAY. A COLD FRONT WILL APPROACH FROM THE NORTHWEST
ON FRIDAY NIGHT AND THEN MOVE ACROSS THE AREA ON
SATURDAY...BRINGING A THREAT FOR SHOWERS AND THUNDERSTORMS.
THERE IS UNCERTAINTY ON TIMING...COVERAGE AND INTENSITY THIS FAR
OUT AND THEN WITH OVERALL PATTERN EVOLUTION BEYOND SATURDAY
EVENING FRONT. STILL APPEARS IT WILL GENERALLY BE LESS ACTIVE THAN
WHAT WE HAVE SEEN MUCH OF THIS SUMMER AND SEASONABLY WARM.
RC
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* NORTHWEST WINDS SHIFTING TO NORTH ARND 10 KT OVERNIGHT.
* WINDS SHIFTING TO NELY LESS THAN 10KT BY LATE MORNING.
KREIN
//DISCUSSION...UPDATED 06Z...
A COLD FRONT EXTEDNING FROM SRN LOWER MICHIGAN ACROSS THE SRN END
OF LAKE MICHIGAN INTO NRN IL WILL CONTINUE TO PUSH SOUTH THROUGH
THE NIGHT. FOLLOWING THE PASSAGE OF THE FRONT...WINDS ACROSS THE
REGION WILL SHIFT TO NLY...ARND 10KT INLAND AND A LITTLE STRONGER
NEAR LAKE MICHIGAN. WINDS AT MDW/GYY SHOULD INCREASE TO 12-18KT
FOR A SHORT TIME.
AS HIGH PRESSURE BUILDS ACROSS THE REGION BEHIND THE FRONT...THE
PRESSURE GRADIENT WILL WEAKEN AND WIND SPEEDS SHOULD DIMINISH. THE
COMBINATION OF THE SLACK PRESSURE GRADIENT AND DIFFERENTIAL LAND-
WATER HEATING SHOULD ALLOW A LAKE BREEZE TO DEVELOP. THE LATEST
HIGH RES MODEL GUIDANCE SUGGESTS THAT THE LAKE BREEZE SET UP INVOF
ORD/MDW BY LATE MORNING...WITH WINDS BECMG NNELY BY LATE MORNING
AND THEN VEERING MORE NELY-ENELY THROUGH THE DAY. WINDS SHOULD BE
LESS THAN 10 KT BEHIND THE LAKE BREEZE. THE BOUNDARY IS NOT
EXPECTED TO REACH DPA/RFD AND WINDS THERE BACK NWLY THROUGH THE
DAY TOMORROW. AT GYY...WINDS SHOULD REMAIN A BIT STRONGER AND
NNELY THROUGH THE DAY. BY TOMORROW EVENING...THE LAKE BREEZE
SHOULD WASH OUT AND WINDS SHOULD BECM LGT/VRBL AS THE CENTER OF
THE HIGH PRESSURE CROSSES THE REGION.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE IN WIND TRENDS WITH RESPECT TO LAKE BREEZE
DETAILS...OTRW HIGH CONFIDENCE IN WIND TRENDS.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. LIGHT WEST WINDS TURNING EAST WITH LAKE BREEZE IN
THE AFTERNOON.
THURSDAY...VFR. LIGHT SOUTH WINDS TURNING EAST-SOUTHEAST WITH LAKE
INFLUENCE IN THE AFTERNOON.
FRIDAY...VFR SOUTH WINDS.
SATURDAY...VFR. CHANCE TSRA. SOUTHWEST WINDS.
SUNDAY...VFR. WESTERLY WINDS.
MDB
&&
.MARINE...
230 PM CDT
A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE LAKE THIS EVENING
TURNING WINDS NORTH AND EVEN BRIEFLY NORTH-NORTHEAST. THERE IS
LIKELY TO BE SCATTERED SHOWERS AND A FEW STORMS AHEAD OF THE FRONT
ACROSS THE SOUTHERN HALF OF THE LAKE THROUGH MID-EVENING. THE
NORTHERLY WINDS BEHIND THE FRONT ARE EXPECTED TO REACH 15 TO 20 KT
FOR A 3-4 HOUR OR SO PERIOD LATE TONIGHT INTO EARLY TUESDAY
MORNING WITH POSSIBLY A FEW HIGHER GUSTS. BECAUSE OF THE SHORT
DURATION OF THE HIGHER SPEEDS...THIS IS EXPECTED TO ONLY BUILD
WAVES TO 2 TO 4 FEET ACROSS THE ILLINOIS AND INDIANA NEARSHORES ON
TUESDAY MORNING. HIGH PRESSURE IS THEN EXPECTED TO MOVE OVER THE
LAKE FOR A QUIET MIDWEEK PERIOD.
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:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
422 AM EDT TUE JUL 21 2015
.SYNOPSIS...
ISSUED AT 421 AM EDT TUE JUL 21 2015
HIGH PRESSURE WILL MOVE INTO THE GREAT LAKES AND OHIO VALLEY
REGION TODAY BRINGING COOLER TEMPERATURES AND LESS HUMID AIR. IT
WILL BE MOSTLY SUNNY TODAY WITH HIGHS IN THE MIDDLE TO UPPER 70S.
WITH MOSTLY CLEAR SKIES AND LIGHT WINDS TONIGHT...LOW TEMPERATURES
WILL FALL INTO THE 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 421 AM EDT TUE JUL 21 2015
SHORT WAVE MOVING ACROSS THE GREAT LAKES THIS MORNING WITH
ASSOCIATED COLD FRONT SLOWLY WORKING SOUTH ACROSS OUR LOCAL AREA.
A FEW ISOLATED SHOWERS HAD POPPED ALONG FRONT ACROSS NORTHERN
COUNTIES EARLY THIS MORNING. HIRES HRRR AND RAP GUIDANCE HAD THIS
HANDLED AND INDICATE AN ISOLATED SHRA REMAINS POSSIBLE THROUGH
DAYBREAK IN THE NORTH AND NORTHEAST NEAR FRONT. A FEW OF THE HRRR
RUNS TRIES TO DEVELOP WEAK SHOWERS ALONG FRONT IN THE SOUTHEAST
LATER THIS MORNING. RECENT RADAR RETURNS HAVE BEGUN TO WEAKEN AND
EXPECT MOST ACTIVITY WILL DIMINISH OR REMAIN VERY ISOLATED. WILL
CARRY AN ISOLATED SHRA THROUGH 12Z DOWNSTREAM FROM CURRENT RADAR
RETURNS BUT MOST AREAS WILL REMAIN DRY.
ONCE COLD FRONT EXITS THE AREA HIGH PRESSURE WILL BUILD IN WITH
SKIES BECOMING MOSTLY SUNNY. COOLER AND LESS HUMID AIR WILL FOLLOW
TODAY. HIGHS IN THE 70S WITH COMFORTABLE HUMIDITY LEVELS. WITH HIGH
OVER THE REGION TONIGHT SKIES WILL BE CLEAR AND WINDS LIGHT. THIS
WILL ALLOW MIN TEMPS TO DROP INTO THE 50S.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 421 AM EDT TUE JUL 21 2015
A TRANQUIL PATTERN WILL PERSIST THROUGH FRIDAY AS AN UPPER LEVEL
RIDGE GRADUALLY BUILDS NORTH OF THE OHIO RIVER. KEPT THE FORECAST
DRY THROUGH FRIDAY NIGHT GIVEN A SEASONALLY DRY
SOUNDING...SOMEWHAT OF A LOW LEVEL CAP...LARGE SCALE SUBSIDENCE
AND STABLE MID LEVEL LAPSE...GENERALLY 4.0 TO 6.5 C/KM. KEPT THE
GENERAL ONGOING TIMING FOR STORMS THIS WEEKEND AS SOME SHORT WAVE
ENERGY FROM AN UPPER LEVEL TROF WILL BE ABLE TO TOP THE RIDGE AND
DESCEND INTO THE WESTERN/UPPER GREAT LAKES REGION. BOTH THE GFS
AND THE ECMWF ARE IN AGREEMENT WITH THE TIMING OF THIS SYSTEM.
THESE MODELS ALSO EXPAND THE UPPER LEVEL RIDGE FARTHER NORTHEAST
WITH 500 HEIGHTS BUILDING ABOVE 590 DEKAMETERS NEAR THE END OF THE
PERIOD. OTHERWISE...HIGHS SHOULD BE FROM AROUND 80 TO THE MID 80S
WITH LOWS AROUND 60 RISING INTO THE MID 60S AS THE UPPER LEVEL
RIDGE BUILDS NORTHEAST EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 145 AM EDT TUE JUL 21 2015
A FEW ISOLATED SHOWERS HAVE DEVELOPED NEAR THE FRONT EARLY THIS
MORNING. COVERAGE IS MINIMAL SO WILL NOT INCLUDE IN TAFS GIVEN
SUCH LOW PROBABILITY OF ANY RESTRICTIONS AT TERMINALS. OTHERWISE
FRONT WILL CLEAR TAF SITES OVERNIGHT AND HIGH PRESSURE WILL BUILD
IN. WINDS WILL BECOME NORTHERLY THIS MORNING THEN BACK TO
NORTHWEST THIS AFTENROON IN THE 8 TO 12 KNOT RANGE. CLEAR SKIES
AND LIGHT WINDS TONIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1257 AM EDT Tue Jul 21 2015
...Updated Aviation Discussion...
...Forecast Update...
Issued at 1200 AM EDT Tue Jul 21 2015
Complex of storms coming in from southeast PAH`s area has quite a
bit of lightning with it. Line is transitioning east fairly rapidly,
and right on the edge of the outflow, so have a warning out for that
line. That line is moving into an area that received rain earlier,
so it should become more elevated in nature overtime. Will have to
watch for training though in this region.
Have additional lines of storms, one near Louisville and southeast,
another nearing Madison, IN, and a last one over central Indiana.
The latter is decaying and it looks like the focus will be more on
the storms over KY the next few hours.
Updated pops in the gridded forecast to account for current radar
trends and matched obs for the rest of the forecast.
Issued at 825 PM EDT Mon Jul 20 2015
Made some minor tweaks to precip chances and hourly temps/dewpts
overnight. Overall though the forecast was in good shape. The
current line of convection stretching from central IN to southern MO
is progged to push eastward through our area between roughly 9pm to
4am. A few cells have popped up in the Bluegrass region also. With
decent CAPE/DCAPE values over the region and around 30 kts of bulk
shear, storms will pose a damaging wind threat initially. Storms
are beginning to become more clustered in nature to our west with an
increasing risk for training cells and flash flooding. The best
spots for svr convection look to be over south central KY and the
Bluegrass where the best bubbles of instability exist. However,
instability will be waning as we go through the evening hours. Of
greater concern overnight may be the flash flood threat as slow
moving storm clusters move through the area.
.SHORT TERM (Now through Tuesday Night)...
Issued at 315 PM EDT Mon Jul 20 2015
Plenty of debris cloudiness overhead as a result of convection that
affected western Kentucky early this morning. Within the last hour
we have seen storms develop where the old outflow boundary is
interacting with the Cumberland Escarpment, but these storms are
already pushing onto the Plateau as we speak. Main challenge is
timing and impact of the round, or rounds of storms that could
affect mainly central Kentucky through tonight.
Even the hi-res models seem to really be struggling from one run to
the next, so this is quite a low-confidence forecast. A couple of
weak swirls were apparent in visible imagery over southern Illinois
and western Kentucky, but even this juicy environment is not
responding yet. Earlier HRRR runs have seemed to be the only models
with any handle on initial conditions, and have hinted that one
round of convection could come through in the hours just before
sunset, with others keying on the actual front which would arrive
around midnight. Less confident in the SPC slight risk as progged
DCAPE is well out of sync with current analysis, and the effective
source of lift remains unclear. Best chance is from roughly 22Z to
05Z Tue, but not likely to affect that entire time period.
Even with the low-confidence forecast, any storms that do develop
could be prolific rain producers due to high precipitable water and
storm motion parallel to a nearly stationary boundary. Flash Flood
Guidance is quite low especially across the Bluegrass, where 1-hr
FFG is 1.5 inches or less in many places. Therefore will continue
with the Flash Flood Watch until Tuesday morning, but no extension
is planned unless convective trends show themselves more clearly.
Whatever organized storms we see should clear the area around
midnight or not too long after. Wind shift arrives by mid-morning,
but we`ll hang on to high dewpoints and chance POPs through the day
as fropa seems to occur in pieces. Mid-level WNW winds picking up to
around 30 kt could support a few strong storms with gusty winds over
east-central KY, but organized SVR potential is farther north and
east as our precip chances will be diminishing as the afternoon
progresses. Chance POPs in the middle of the day will be dropping
off by mid/late afternoon, with only south central KY in a slight
chance for storms for Tue night. Drier air will be filtering in,
with dewpoints dropping into the lower/mid 60s and temps dropping to
the upper 60s/near 70.
.LONG TERM (Wednesday through Monday)...
Issued at 300 PM EDT Mon Jul 20 2015
The synoptic pattern at the start of the long term period will
feature generally northwest flow across the Ohio Valley, as ridging
over the south-central CONUS remains in place. This ridging will
actually build NNE into the region by this weekend, bringing a
return to the hot and humid conditions.
A weak frontal boundary will have pushed into TN at the start of the
long term period. There is some discrepancy in the guidance as to
how far south this boundary will get, which will be the deciding
factor as to whether or not southern KY ends up dry. For now, will
continue with slight chance pops across southern KY Wednesday into
Thursday as impulses riding along this boundary may be enough to
bring precip into the region, but suspect most will end up dry.
Given the majority of the region will be on the northern side of the
front, temperatures and humidity values will be rather comfortable.
Look for highs in the low to mid 80s with dewpoints in the low to
mid 60s, perhaps pushing into the upper 60s over southern KY.
Heading into Friday and through the upcoming weekend, upper-level
ridging will build back into the Ohio Valley which will bring
increasing heat and humidity. The region will still be on the
periphery of the mid-level westerlies/northwesterlies, so cannot
completely rule out thunderstorm chances this weekend. It appears
the best chance for a disturbance to impact the region may come
Saturday night into Sunday, but confidence in that scenario is quite
low and does not warrant any higher mention than just slight chance
to chance POPs (20-30%). Otherwise, it will be hot and humid as
upper-level ridging builds in and 850mb temps rise back to near
20C. Look for highs back in the upper 80s and lower 90s with heat
indices from 95-100 degrees at times.
&&
.AVIATION (06Z TAF Update)...
Updated 1255 AM EDT Tue Jul 21 2015
Have showers and storms affecting the terminals over the next few
hours. KSDF has the best chance to get out of it sooner, but
atmosphere still too juicy to pull it altogether. Also watching to
see if storms over central Indiana redevelop. For now, have pulled
VCTS for SDF at 7Z, but for all sites go to MVFR conditions in the
muggy airmass behind these storms. Should see some improvement as
winds shift to northeasterly through the day and cigs lift. Decided
to pull mention of showers for the afternoon tomorrow, as
probabilities are in the 20-30 percent range for the sites.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FLASH FLOOD WATCH until 8 AM EDT /7 AM CDT/ this morning FOR
KYZ029>043-045>049-054>057-065>067-077-078-081-082.
IN...FLASH FLOOD WATCH until 8 AM EDT this morning FOR INZ078-079-091-
092.
&&
$$
Updates........RJS/AMS
Short Term.....RAS
Long Term......KJD
Aviation.......RJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1202 AM EDT Tue Jul 21 2015
...Forecast Update...
Issued at 1200 AM EDT Tue Jul 21 2015
Complex of storms coming in from southeast PAH`s area has quite a
bit of lightning with it. Line is transitioning east fairly rapidly,
and right on the edge of the outflow, so have a warning out for that
line. That line is moving into an area that received rain earlier,
so it should become more elevated in nature overtime. Will have to
watch for training though in this region.
Have additional lines of storms, one near Louisville and southeast,
another nearing Madison, IN, and a last one over central Indiana.
The latter is decaying and it looks like the focus will be more on
the storms over KY the next few hours.
Updated pops in the gridded forecast to account for current radar
trends and matched obs for the rest of the forecast.
Issued at 825 PM EDT Mon Jul 20 2015
Made some minor tweaks to precip chances and hourly temps/dewpts
overnight. Overall though the forecast was in good shape. The
current line of convection stretching from central IN to southern MO
is progged to push eastward through our area between roughly 9pm to
4am. A few cells have popped up in the Bluegrass region also. With
decent CAPE/DCAPE values over the region and around 30 kts of bulk
shear, storms will pose a damaging wind threat initially. Storms
are beginning to become more clustered in nature to our west with an
increasing risk for training cells and flash flooding. The best
spots for svr convection look to be over south central KY and the
Bluegrass where the best bubbles of instability exist. However,
instability will be waning as we go through the evening hours. Of
greater concern overnight may be the flash flood threat as slow
moving storm clusters move through the area.
.SHORT TERM (Now through Tuesday Night)...
Issued at 315 PM EDT Mon Jul 20 2015
Plenty of debris cloudiness overhead as a result of convection that
affected western Kentucky early this morning. Within the last hour
we have seen storms develop where the old outflow boundary is
interacting with the Cumberland Escarpment, but these storms are
already pushing onto the Plateau as we speak. Main challenge is
timing and impact of the round, or rounds of storms that could
affect mainly central Kentucky through tonight.
Even the hi-res models seem to really be struggling from one run to
the next, so this is quite a low-confidence forecast. A couple of
weak swirls were apparent in visible imagery over southern Illinois
and western Kentucky, but even this juicy environment is not
responding yet. Earlier HRRR runs have seemed to be the only models
with any handle on initial conditions, and have hinted that one
round of convection could come through in the hours just before
sunset, with others keying on the actual front which would arrive
around midnight. Less confident in the SPC slight risk as progged
DCAPE is well out of sync with current analysis, and the effective
source of lift remains unclear. Best chance is from roughly 22Z to
05Z Tue, but not likely to affect that entire time period.
Even with the low-confidence forecast, any storms that do develop
could be prolific rain producers due to high precipitable water and
storm motion parallel to a nearly stationary boundary. Flash Flood
Guidance is quite low especially across the Bluegrass, where 1-hr
FFG is 1.5 inches or less in many places. Therefore will continue
with the Flash Flood Watch until Tuesday morning, but no extension
is planned unless convective trends show themselves more clearly.
Whatever organized storms we see should clear the area around
midnight or not too long after. Wind shift arrives by mid-morning,
but we`ll hang on to high dewpoints and chance POPs through the day
as fropa seems to occur in pieces. Mid-level WNW winds picking up to
around 30 kt could support a few strong storms with gusty winds over
east-central KY, but organized SVR potential is farther north and
east as our precip chances will be diminishing as the afternoon
progresses. Chance POPs in the middle of the day will be dropping
off by mid/late afternoon, with only south central KY in a slight
chance for storms for Tue night. Drier air will be filtering in,
with dewpoints dropping into the lower/mid 60s and temps dropping to
the upper 60s/near 70.
.LONG TERM (Wednesday through Monday)...
Issued at 300 PM EDT Mon Jul 20 2015
The synoptic pattern at the start of the long term period will
feature generally northwest flow across the Ohio Valley, as ridging
over the south-central CONUS remains in place. This ridging will
actually build NNE into the region by this weekend, bringing a
return to the hot and humid conditions.
A weak frontal boundary will have pushed into TN at the start of the
long term period. There is some discrepancy in the guidance as to
how far south this boundary will get, which will be the deciding
factor as to whether or not southern KY ends up dry. For now, will
continue with slight chance pops across southern KY Wednesday into
Thursday as impulses riding along this boundary may be enough to
bring precip into the region, but suspect most will end up dry.
Given the majority of the region will be on the northern side of the
front, temperatures and humidity values will be rather comfortable.
Look for highs in the low to mid 80s with dewpoints in the low to
mid 60s, perhaps pushing into the upper 60s over southern KY.
Heading into Friday and through the upcoming weekend, upper-level
ridging will build back into the Ohio Valley which will bring
increasing heat and humidity. The region will still be on the
periphery of the mid-level westerlies/northwesterlies, so cannot
completely rule out thunderstorm chances this weekend. It appears
the best chance for a disturbance to impact the region may come
Saturday night into Sunday, but confidence in that scenario is quite
low and does not warrant any higher mention than just slight chance
to chance POPs (20-30%). Otherwise, it will be hot and humid as
upper-level ridging builds in and 850mb temps rise back to near
20C. Look for highs back in the upper 80s and lower 90s with heat
indices from 95-100 degrees at times.
&&
.AVIATION (00Z TAF Update)...
Updated 720 PM EDT Mon Jul 20 2015
The main TAF updates with this package are delaying the timing of
t-storms this evening and adding an MVFR group for tomorrow
morning. A broken line of convection was firing to our west from
central IN to southern MO as of 23Z. Expect this line to continue
to move east through the evening hours. The latest SPC HRRR has a
good handle on the line so used that model for timing. This should
put the best t-storm chances at SDF/BWG between 2-7Z and at LEX
between 4-9Z respectively. Since it is a broken line and
strength/coverage of storms is expected to wane a bit by late
evening, still went with VCTS at all TAF sites. Will need to amend
with predominant t-storms and reduced flight conditions if the
storms hold together.
After the convection moves through tonight, we should see a period
of MVFR flight conditions before a sfc front moves through between
13-15Z. The front will shift winds from WSW to NW. After the front
passes, low clouds should scour out and lift.
Late in the day tomorrow a second sfc boundary will approach the
region bringing isolated convection. Will include a VCSH to account
for this late in the TAF period. This front will shift winds from
NW to N at the end of the TAF period or just beyond.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...FLASH FLOOD WATCH until 8 AM EDT /7 AM CDT/ this morning FOR
KYZ029>043-045>049-054>057-065>067-077-078-081-082.
IN...FLASH FLOOD WATCH until 8 AM EDT this morning FOR INZ078-079-091-
092.
&&
$$
Updates........RJS/AMS
Short Term.....RAS
Long Term......KJD
Aviation.......AMS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
352 AM EDT TUE JUL 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM EDT TUE JUL 21 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT
OVER THE UPR LKS BTWN CLOSED LO NEAR JAMES BAY AND UPR RDG OVER THE
ROCKIES/WRN PLAINS. A DISTURBANCE DROPPING SEWD THRU NW ONTARIO
IN CONCERT WITH SOME MSTR IN THE H85-7 LYR SHOWN ON THE 00Z INL/YPL
RAOBS IS BRINGING SCT-BKN AC THRU MUCH OF NW ONTARIO...NRN MN AND
LK SUP. FARTHER TO THE W IN MANITOBA CLOSER TO THE UPR RDG AXIS
AND UNDER STRONGER DEEP LYR QVECTOR DVGC...THE 00Z THE PAS RAOB AT
THE NRN END OF LK WINNIPEG SHOWS A MUCH SHARPER MID LVL INVRN. SKIES
IN THIS AREA ARE MOCLR. DESPITE SOME RELATIVELY DRY LLVL AIR AND
LLVL CAA...STEADY NW WINDS UNDER SHARPER PRES GRADIENT WELL E OF HI
PRES CENTER IN THE NRN PLAINS HAS LIMITED THE DIURNAL TEMP DROP.
RELATIVELY QUIET QUIET WX WL DOMINATE THE SHORT TERM. MAIN FCST
CONCERNS FOCUS ON CLD TRENDS TODAY AND TEMPS TODAY/TNGT.
TODAY...SHRTWV DIGGING SEWD THRU NW ONTARIO IS FCST TO BE OVER NE LK
SUP BY 12Z AND THEN OVER SE ONTARIO BY 00Z THIS EVNG...WITH DNVA/
SHARPER DEEP LYR QVECTOR OVER THE UPR LKS IN ITS WAKE BRINGING 12HR
H5 HGT RISES UP TO 50M IN ITS WAKE. EXPECT SCT-BKN CU TO DEVELOP BY
LATE MRNG WITH DAYTIME HEATING UNDER H85 THERMAL TROF/LINGERING
MSTR...BUT TENDENCY DURING THE AFTN SHOULD BE FOR THE CU TO SCT OUT
WITH SHARPENING SUBSIDENCE INVRN/ARRIVAL OF DRIER AIR SHOWN ON THE
PAS RAOB. SOME OF THE HI RES MODELS EVEN GENERATE SOME ISOLD
SHOWERS OVER THE ECNTRL CWA TOWARD NOON...BUT WL MAINTAIN DRY FCST
FOR NOW GIVEN RELATIVELY STABLE MID LYRS SHOWN ON THE UPSTREAM
RAOBS/FCST SDNGS. WINDS MAY ALSO GET A BIT GUSTY AGAIN THIS MRNG
UNDER SHARPER PRES GRADIENT/STEEPENING LLVL LAPSE RATES...BUT SFC HI
PRES MOVING OVER THE CWA IN THE AFTN SHOULD RESULT IN DIMINISHING
WINDS. THE MORE PERSISTENT GUSTY WINDS WL BE OVER THE E...WHERE THE
TIGHTER GRADIENT WL LINGER LONGER AND LK BREEZE COMPONENT OFF LK SUP
WL ACCENTUATE THIS FLOW. EXPECT THE LOWEST MAX TEMPS IN THIS AREA AS
WELL WITH MORE LK SUP MODERATION. LOCATIONS NEAR THE SHORE E OF MQT
WL SEE HI TEMPS HOLDING IN THE 60S. AS H85 TEMPS REBOUND TO NEAR 12Z
ALONG THE WI BORDER LATER IN THE DAY...THE MERCURY SHOULD RISE WELL
INTO THE 70S AND AT LEAST APRCH 80 AT A FEW LOCATIONS OVER THE
SCENTRAL WITH DOWNSLOPE FLOW AND LIMITED LK BREEZE OFF LK MI.
TNGT...EXPECT LINGERING CU TO DSPT EARLY AND GIVE WAY TO MOCLR
SKIES UNDER LARGER SCALE SUBSIDENCE/LOSS OF DAYTIME HEATING. LO
TEMPS WL BE COOLEST OVER THE W CLOSER TO SFC HI PRES RDG AXIS APRCHG
WRN LK SUP/WEAKER PRES GRADIENT. THE COOL SPOTS MAY SEE THE
THERMOMETER READ AS LO AS 45 BY DAYBREAK.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM EDT TUE JUL 21 2015
IMPACTS...NO SIGNIFICANT IMPACTS ARE WITHIN PREDICTABLE RANGE.
POSSIBILITY FOR STRONG TO SEVERE STORMS OVER PARTS OF THE REGION
LATE FRI INTO SAT...BUT STILL VERY UNCERTAIN ON THAT ASPECT.
MAY SEE SHOWERS AND THUNDERSTORMS ALONG AND/OR NEAR THE WI BORDER
THU AS MODELS SHOW A WARM FRONT MOVING INTO THE AREA FROM THE
W...WHICH MAINLY INCREASES MID LEVEL MOISTURE ENOUGH TO ALLOW FOR
WEAK CONVECTIVE POTENTIAL. MODELS ARE SLOWER WITH THE FRONT THAN
THEY WERE YESTERDAY...SO WILL CONTINUE TREND OF LOWERING DEW POINTS
ON WED AFTERNOON...BUT FIRE WEATHER CONCERNS WILL BE MINIMAL GIVEN
LIGHT WINDS. WILL KEEP SLIGHT CHANCE POPS INTO AREAS ALONG THE WI
BORDER THU.
THE DISTURBANCE THAT THE WARM FRONT IS TIED TO WILL MOVE ACROSS
MANITOBA CANADA AND HUDSON BAY FRI INTO SUN...DRAGGING A SFC
TROUGH/COLD FRONT THROUGH THE AREA. DEFINITELY SOME DIFFERENCES
BETWEEN MODELS WITH THIS SYSTEM...WITH THE 00Z/21 GFS BEING STRONGER
AND FARTHER S THAN THE 12Z/20 ECMWF. WILL USE CONSENSUS GUIDANCE
GIVEN THE UNKNOWNS INVOLVED...WHICH WILL SHOW SHOWERS AND
THUNDERSTORMS MOVING W TO E ACROSS THE CWA FROM LATE FRI THROUGH
SAT. SUN LOOKS DRY FOR NOW. DEPENDING ON TIMING AND OTHER
FACTORS...COULD SEE INGREDIENTS COME TOGETHER FOR SOME STRONG TO
SEVERE STORMS MAINLY S OF THE CWA.
SUN LOOKS DRY AND MON MAY SEE SOME RAIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 121 AM EDT TUE JUL 21 2015
VFR CONDITIONS WILL PREVAIL THROUGH THE FCST PERIOD ALTHOUGH MORE
VFR CU/SC ARE EXPECTED ON TUESDAY. WINDS COULD BE GUSTY AGAIN WITH
GUSTS TO AROUND 20 KNOTS AT CMX/SAW IN THE AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 AM EDT TUE JUL 21 2015
STEADY WNW WINDS UP TO ABOUT 20 KTS WILL DIMINISH TONIGHT WITH THE
CLOSER APPROACH OF HI PRES FROM THE NORTHERN PLAINS. SINCE THE HI
PRES WILL LINGER NEAR THE GREAT LAKES MUCH OF THIS WEEK...WINDS
SHOULD BE UNDER 20 KTS MOST OF THE TIME. SOME STRONGER WINDS UP TO
20 KTS WILL BE POSSIBLE ON FRI/SAT AS A COLD FRONT CROSSES THE
REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
308 AM CDT TUE JUL 21 2015
.DISCUSSION...
CURRENTLY A SNAKING LINE OF CONVECTION EXTENDING FROM THE TEXAS
PANHANDLE TO EASTERN KENTUCKY CONTINUES TO FIZZLE MIDWAY ACROSS
THE MIDSOUTH THIS MORNING...LEAVING ONLY A FEW SHOWERS IN EASTERN
ARKANSAS AND A BLANKET OF MID AND HIGH LEVEL MOISTURE. CLOUD
COVER WAS KEEPING TEMPERATURES A DEGREE OR TWO WARMER THAN THIS
TIME LAST NIGHT FROM I-40 SOUTH...WHILE EVENING RAIN EARLIER AND
A WEAK OUTFLOW BOUNDARY IS PROVIDING COOLER TEMPERATURES FARTHER
NORTH. THE HRRR SHOWS NEW CONVECTION FORMING ACROSS THE NORTH BY 4
AM...BUT RADAR TRENDS AND MESOANALYSIS IS SUGGESTING MORE
STABILITY IN THIS REGION.
FOR TODAY THROUGH THURSDAY...THE MIDSOUTH WILL TAKE A SHORT BREAK
FROM THE HEAT THIS PERIOD...WITH THE ONLY EXCEPTION BEING THE
SOUTHERN TWO TIER OF COUNTIES TODAY....WHERE A HEAT ADVISORY IS
IN EFFECT STARTING LATER THIS MORNING. THE UPPER RIDGE IS EXPECTED
TO SAG FAR ENOUGH SOUTH TO ALLOW THE PREVAILING WESTERLIES...AND
ASSOCIATED DISTURBANCES TO PASS OVER A STALLED SURFACE FRONT.
EACH FEATURE ALLOWING THE CHANCE FOR SHOWERS AND STORMS TO
FORM...WITH A NEAR EQUAL THREAT BOTH DAY AND NIGHT. TOMORROW
APPEARS THE COOLEST BY THE MODELS WITH PLENTY OF HIGHS IN THE 80S
AND WIDESPREAD HEAT INDICES FINALLY DIPPING BELOW 100F. THE
BIGGER QUESTION IS WILL THERE BE A THREAT FOR SEVERE WEATHER OR
FLASH FLOODING. MU CAPE VALUES BY THE MID AFTERNOON HOURS WILL
RANGE FROM 2000 TO 3500 J/KG AND THE POSSIBILITY OF STORMS
TRAINING SEEMS VERY PLAUSIBLE. FEEL PULSE TYPE STORMS WILL
DEVELOP TODAY AND TOMORROW WITH THE GREATER POTENTIAL FOR
SOMETHING MORE ORGANIZED HAPPENING TOMORROW NIGHT AND THURSDAY
WHEN A 25KT LLJ AT 850MB INTERSECTS THE REGION. WILL KEEP THE
SAME MENTION IN THIS MORNINGS HWO WITH THE ADDITION OF A LOCALIZED
FLASH FLOODING THREAT.
FRIDAY THROUGH MONDAY...THE GFS AND EURO ARE IN GOOD AGREEMENT
THAT THE RIDGE WILL BUILD BACK NORTH...BUT THERE ARE SLIGHT
DIFFERENCES ON JUST HOW FAR EAST. THE FARTHER WEST EURO SOLUTION
WOULD KEEP THE MIDSOUTH IN THE CROSSHAIRS FOR MORE MCS
CONVECTION/NORTHWESTERLY FLOW...WHILE THE GFS IS A BIT HOTTER AND
DRIER AS THE RIDGE MOVES INTO THE TENNESSEE RIVER VALLEY. THIS
WOULD LEAD TO PERHAPS ISOLATED DIURNAL CONVECTION AT BEST. FOR
NOW HAVE LEANED MORE TOWARDS THE GFS...AS IT IS HANDLING THE
CURRENT SITUATION BETTER. HIGHS WOULD CLIMB BACK INTO THE MID AND
UPPER 90S...AND THE NEED FOR ADDITIONAL HEAT PRODUCTS LIKELY.
JAB
&&
.AVIATION...
FOR 06Z TAFS
VFR CONDITIONS WITH NORTHERLY WINDS. SOME SCATTERED SHOWERS IN
THE NORTH...HOWEVER...NOT EXPECTING TO REACH ANY OF THE TAF SITES
EARLY THIS MORNING. HOWEVER...AFTERNOON SHOWERS/THUNDERSTORMS ARE
POSSIBLE ON TUESDAY SO HAVE VICINITY THUNDERSTORMS AT ALL SITES.
TLSJR
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR PHILLIPS.
MO...NONE.
MS...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR CALHOUN-CHICKASAW-COAHOMA-ITAWAMBA-LAFAYETTE-LEE MS-
MONROE-PANOLA-PONTOTOC-QUITMAN-TALLAHATCHIE-UNION-YALOBUSHA.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
411 AM CDT Tue Jul 21 2015
.SHORT TERM...
(Today and tonight)
One shortwave trough is lifting northeast across NM this morning,
providing large scale forcing for ascent across the Panhandle and
portions of west TX. At the surface, a cold front was located from
the south plains, extending northeast into central OK. Outflow
from evening convection is forcing the effective front to the
southeast, from near Vernon, to Jayton, to Midland as of 3 AM.
This boundary will likely move into the Big Country and western
Concho Valley this morning but is expected to erode by midday,
given the shallow nature of the "cool" airmass. This should have
only a slight effect on temperatures this afternoon, mainly over
the northwest quadrant of the CWA. Expect highs ranging from the
upper 90s to near 102 degrees this afternoon, with similar heat
indices.
A second shortwave trough is progged to lift northeast across NM
this afternoon and evening, providing another round of convection
to our north and west. The HRRR and ARW both indicate isolated
convection along the western periphery of the CWA this afternoon,
but the NAM, GFS, and ECMWF are largely dry. While a rogue
shower/storm can`t be ruled out this afternoon, coverage should be
significantly limited given the warm temps aloft, weak cap, and
depth of the boundary layer (increasing dry air entrainment into
potential updrafts). Thus, no PoPs will be carried in the
forecast. Expect partly cloudy conditions overnight with overnight
lows in the mid 70s.
Johnson
.LONG TERM...
(Wednesday through next Monday)
By Wednesday, the frontal zone currently currently extending from
the TX panhandle into Oklahoma will be lifting northward into the
central plains. On Thursday, the upper level ridge will re-center
and strengthen directly over west Texas. With the ridge in place
across the southern plains through early next week, persistent
southwesterly flow across the Rocky Mountains will result in lee
troughing, and continue warm, southerly flow for our area through
the extended period. Due to this ridging and persistent southerly
flow, 850mb temperatures will warm a degree or two Celsius by
Monday. This will result in persistent hot and dry weather for our
area with highs in the upper 90s to around 100 degrees, lows in
the mid to upper 70s, and no chance for rainfall.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 98 76 98 76 98 / 5 5 0 0 0
San Angelo 102 75 100 76 99 / 0 0 0 0 0
Junction 100 74 98 74 97 / 0 0 0 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
400 AM CDT TUE JUL 21 2015
.SHORT TERM...
AS WAS EXPECTED...A FAIRLY LARGE MCS DEVELOPED ALONG AND BEHIND A
WEAK COLD FRONT RESULTING IN CONSIDERABLE AMOUNTS OF PRECIPITATION
ACROSS SOME AREAS IN THE NORTHERN PART OF OUR FORECAST AREA. THE
MCS DEVELOPED A STRONG OUTFLOW BOUNDARY WHICH SURGED THROUGH THE
LUBBOCK AREA BEFORE MIDNIGHT AND WAS LOCATED ALONG A SEMINOLE...
POST...TO KNOX CITY LINE AT 3 AM. THIS LEAVES ONLY STONEWALL COUNTY
TO THE SOUTHEAST OF THE OUTFLOW BOUNDARY. ALOFT...THE 00Z UPPER-AIR
ANALYSIS SHOWS THE CENTER OF THE HIGH PRESSURE RIDGE HAS SHIFTED A
BIT FURTHER SOUTH OVER SOUTH CENTRAL TEXAS WITH A GOOD MONSOON
MOISTURE PLUME LOCATED ACROSS NEW MEXICO CURVING BACK OVER THE TEXAS
PANHANDLE. IT WAS TOUGH TO PICK OUT ANY FORM OF SHORTWAVE ACTIVITY
IN THE UPPER-AIR ANALYSIS AND THE MCS HAS PUMPED CONSIDERABLE
MOISTURE INTO THE ATMOSPHERE AS SHOWN IN THE WATER VAPOR LOOP...ALSO
MASKING ANY SHORTWAVES THAT MAY BE SEEN OVER THE TEXAS PANHANDLE.
IT DOES HOWEVER SHOW A WEAK SWIRL OVER WESTERN NEW MEXICO THAT WILL
BE MOVING TOWARDS THE TEXAS PANHANDLE THROUGH THE DAY WHICH MAY COME
INTO PLAY LATER ON.
MODELS DID A POOR JOB INITIALIZING WITH THE CONVECTION AT 00Z WHICH
COMPLICATES THE FORECAST. THE ONLY MODEL THAT SEEMINGLY HAS A
DECENT START IS THE TTU-WRF AND LEANED HEAVILY TOWARDS THIS MODEL
FOR THE FORECAST THIS MORNING. THE MCS HAS ALREADY PUSHED EAST OUT
OF THE TEXAS PANHANDLE WITH OTHER LIGHTER SHOWER AND ISOLATED
THUNDERSTORMS DEVELOPING ACROSS THE WESTERN SOUTH PLAINS GENERALLY
ALONG AND WEST OF A TULIA TO BROWNFIELD LINE. TTU-WRF AND TO SOME
EXTENT THE NAM...HRRR...AND GFS DECREASE COVERAGE OF ACTIVITY
THROUGH THIS MORNING WITH A LULL IN PRECIPITATION BY MID-DAY.
EVENTUALLY...THE TTU-WRF REDEVELOPS SCATTERED CONVECTION ACROSS THE
WESTERN SOUTH PLAINS BY 21Z AND PUSHES THIS TO THE EAST TOWARDS THE
CAPROCK. THIS SOLUTION SEEMS REASONABLE AS CLOUD COVER WILL TAKE A
BIT TO DISSIPATE THROUGH THE MORNING AND THEN ALLOW SOME SURFACE-
BASED INSTABILITY TO DEVELOP BY THE AFTERNOON. THE WEAK WAVE SEEN
IN THE WATER VAPOR LOOP MAY MOVE CLOSE ENOUGH TO PROVIDE SOME WEAK
LIFT BUT ALL TOGETHER CONDITIONS REMAIN MARGINAL FOR WIDESPREAD
STORMS. FORECAST SOUNDINGS ACROSS THE AREA SHOW QUITE THE RANGE OF
SBCAPE VALUES RANGING FROM SUB 500 J/KG IN THE NAM AND TTU-WRF TO
ALMOST 2500 J/KG IN THE HRRR AND RAP. IF STORMS DO DEVELOP...COULD
ONCE AGAIN SEE A MARGINAL SEVERE WEATHER THREAT MAINLY IN THE FORM
OF DOWNBURSTS.
ALL THIS PUT TOGETHER MEANS THAT HIGH TEMPERATURES WERE UNDERCUT
ACROSS THE NORTHERN SOUTH PLAINS WHERE THE HEAVIEST RAINFALL FELL
LAST NIGHT/EARLY THIS MORNING AS SURFACE MOISTURE AND REMNANT CLOUD
COVER SHOULD HELP TO MODERATE TEMPERATURES SOME. THE REST OF THE
AREA SHOULD SEE TEMPERATURES A FEW DEGREES COOLER THAN YESTERDAY BUT
STILL IN THE MID TO UPPER 90S. CHANCE FOR PRECIP WILL INITIALLY BE
HIGHEST THIS MORNING...A LULL IN THE LATE MORNING EARLY AFTERNOON...
THEN PICKING UP AGAIN LATE THIS AFTERNOON FOR THE SOUTH PLAINS. THE
ROLLING PLAINS LOOKS TO BE TOO FAR TO THE EAST TO SEE MUCH IN THE
WAY OF PRECIP AS THE FRONT/OUTFLOW BOUNDARY IS HARD TO FIND AND ALL
MODELS KEEP THE EASTERN ONE THIRD OF THE FORECAST AREA DRY. ONLY
UNCERTAINTY IS HOW LONG POPS WILL GO PAST MIDNIGHT AS THE TTU-WRF
TRIES TO DEVELOP ANOTHER WEAK MESOSCALE CONVECTIVE COMPLEX AROUND
SUNSET BUT THEN DISSIPATES IT BY MIDNIGHT LOCAL TIME BEFORE IT MAKES
IT TO THE EDGE OF THE CAPROCK. A DECENT LOW-LEVEL JET IS FORECAST
TO DEVELOP OVERNIGHT WHICH MAY HELP TO KEEP CONVECTION GOING BUT IT
WILL VEER BETWEEN 06 AND 12Z FROM SOUTH TO SOUTHWEST...NOT GOOD FOR
MAINTENANCE OF ANY CONVECTION THAT DEVELOPS.
JORDAN
.LONG TERM...
SEMI-ACTIVE PATTERN AT PRESENT LOOKS TO PERSIST AT LEAST ONE MORE
DAY BEFORE A SUBTROPICAL HIGH RE-EXERTS ITSELF SQUARELY ATOP THE
ROLLING PLAINS FROM THURSDAY AND LASTING THROUGH EARLY NEXT WEEK.
UNTIL THAT MONOTONOUS PATTERN IS REALIZED...A RESIDUAL LAYER OF
MOISTURE AND SLIGHTLY COOLER TEMPS ALOFT WILL PERSIST PARTICULARLY
ACROSS EASTERN NM AND OUR WESTERN ZONES ON WEDNESDAY. BROAD
SURFACE TROUGHING JUST WEST OF THE STATE LINE ALONG WITH WEAK
UPSLOPE FLOW SHOULD HELP TRIGGER SOME AFTN/EVNG STORMS...BUT POPS
ELSEWHERE ON WEDNESDAY WERE TRIMMED BELOW MENTION AS HEIGHT FIELDS
ARE PROGGED TO RISE ABOUT 20 METERS THROUGHOUT THE DAY WHICH
IMPLIES TOO MUCH SUBSIDENCE FOR PRECIP IN THIS OTHERWISE WEAKLY
FORCED PATTERN.
BY THURSDAY...LARGE SCALE SUBSIDENCE WILL TAKE GRASP AREA WIDE
WITH ONLY A FEW MORSELS OF PRECIP POSSIBLE ALONG THE WESTERN
PERIPHERY OF THE HIGH - BUT EVEN THESE ARE NOW SHAPING UP MORE
CONDITIONAL THAN EARLIER MODELS INDICATED SO WE HAVE REMOVED
MEASURABLE PRECIP MENTION ON THURSDAY ACROSS OUR WESTERN COUNTIES.
THEREAFTER...JUST MINOR DAILY OSCILLATIONS OF THE HIGH/S CENTER
ARE THE ONLY CHANGES EXPECTED WITH NEGLIGIBLE IMPACTS ON HIGH
TEMPS. CONSIDERING MODELS KEEP 500 MB MAX HEIGHTS AOB 596 DAM...
HIGHS SHOULD NOT PUSH TOO FAR ABOVE CLIMO DESPITE THE OBVIOUS
WARM BIAS STILL PLAGUING MOS.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
14/93
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
328 AM CDT TUE JUL 21 2015
.DISCUSSION...
THE UPPER LEVEL RIDGE THAT HAS DOMINATED THE WEATHER ACROSS THE
REGION FOR THE LAST WEEK IS SHOWING SOME SIGNS OF A SLIGHT
WEAKENING AS A SHORT WAVE MOVES ACROSS ITS NORTHERN PERIPHERY.
THIS HAS ALLOWED A COLD FRONT TO MOVE DOWN INTO NORTHERN OKLAHOMA
AND WEST TEXAS. THIS FRONT WILL STALL OUT ACROSS CENTRAL OKLAHOMA
INTO WEST TEXAS THIS AFTERNOON OR EVENING BEFORE LIFTING BACK TO
THE NORTH BY WEDNESDAY MORNING.
SOME OF THE HIGH CLOUDS ASSOCIATED WITH CONVECTION ACROSS
OKLAHOMA AND THE TEXAS PANHANDLE WILL ATTEMPT TO MOVE INTO NORTH
TODAY BUT THESE CLOUDS SHOULD THIN. THE MAIN AREA OF DENSER CLOUDS
WILL MOVE EAST ACROSS OKLAHOMA. TEMPERATURES TODAY SHOULD BE A
DEGREE OR TWO COOLER VERSUS YESTERDAY THANKS TO THE WEAKENING
RIDGE. EXPECT HIGHS IN THE MID 90S TO NEAR 100 DEGREES ACROSS THE
REGION. THE HRRR INDICATES THAT SOME ISOLATED
SHOWERS/THUNDERSTORMS WILL TRY TO FORM THIS AFTERNOON FROM
GRANBURY THROUGH THE METROPLEX NORTHEAST TOWARD PARIS. THE
SUBSIDENCE ASSOCIATED WITH THE RIDGE WILL PROBABLY BE TOO STRONG
FOR THIS TO OCCUR SO HAVE JUST PLACED 10 PERCENT POPS WITH NO
WEATHER MENTIONED FOR THIS AFTERNOON AND EVENING ALONG AND NORTH
OF A COMANCHE TO EMORY LINE.
THE UPPER RIDGE WILL SHIFT WEST INTO WEST TEXAS AND RE-STRENGTHEN
LATE WEEK. THIS WILL ALLOW TEMPERATURES TO INCREASE BY A FEW
DEGREES LATE WEEK THROUGH THE WEEKEND. WE MAY BE REACH HEAT
ADVISORY CRITERIA ACROSS THE EASTERN THIRD TO HALF SUNDAY/MONDAY.
THE ECMWF AND GFS INDICATE THAT THE RIDGE WILL SHIFT A LITTLE TO
THE NORTH EARLY TO MID NEXT WEEK...WHICH MAY ALLOW FOR SOME LOW
RAIN CHANCES ACROSS THE SOUTHEASTERN AND SOUTHERN ZONES BY THE
MIDDLE OF NEXT WEEK.
58
&&
.AVIATION...
/ISSUED 1151 PM CDT MON JUL 20 2015/
NO CHANGE FOR THIS FORECAST. CONTINUED VFR WITH SOUTHERLY WINDS
8-12 KNOTS AND SOME AFTERNOON GUSTS. 75
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 98 79 98 79 99 / 10 5 5 0 0
WACO, TX 97 75 97 75 97 / 0 0 0 0 0
PARIS, TX 97 76 96 75 96 / 10 10 10 0 0
DENTON, TX 98 77 98 78 99 / 10 10 10 0 0
MCKINNEY, TX 96 77 97 78 98 / 10 5 10 0 0
DALLAS, TX 99 80 99 81 100 / 10 5 5 0 0
TERRELL, TX 97 76 96 76 99 / 10 5 5 0 0
CORSICANA, TX 98 76 97 76 99 / 0 0 5 0 0
TEMPLE, TX 97 74 96 75 97 / 0 0 0 0 0
MINERAL WELLS, TX 96 75 96 75 98 / 10 5 5 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
82/58
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1231 AM CDT TUE JUL 21 2015
.AVIATION...
06Z TAFS...VFR CONDITIONS WILL CONTINUE OUTSIDE OF THE INFLUENCE OF
PERIODS OF HEAVIER RAIN FROM SCATTERED SHOWERS AND THUNDERSTORMS.
THESE STORMS SHOULD CONTINUE TO TAPER OFF FROM WEST TO EAST OVER THE
NEXT SEVERAL HOURS...AND WINDS SHOULD RETURN TO MAINLY AN EASTERLY
DIRECTION. EXPECT WINDS TO TURN MORE SOUTHEASTERLY ACROSS THE
PANHANDLES IN THE AFTERNOON...AND CONVECTION IS AGAIN EXPECTED DURING
THE LATE AFTERNOON AND EVENING HOURS. CONFIDENCE IS LOW IN THE
TIMING OF SAID CONVECTION AT THE TERMINALS TO GO PREVAILING AT THIS
POINT...SO HAVE OPTED FOR PROB30 TO COVER THE MOST LIKELY TIME
PERIODS WITH FURTHER REFINEMENT EXPECTED.
ELSENHEIMER
&&
.PREV DISCUSSION... /ISSUED 242 PM CDT MON JUL 20 2015/
DISCUSSION...
LATEST WATER VAPOR CHANNEL LOOP AND GOES DERIVED TPW SHOWS ANOMALOUS
MOISTURE FLOWING NORTHWARD ACROSS EASTERN NEW MEXICO ON THE WESTERN
EDGE OF UPPER RIDGE. 12Z SOUNDINGS CONFIRM THIS WITH A SIGNIFICANT
INCREASE IN PWAT FROM 00Z LAST NIGHT (1.47 VS 0.82 INCHES). THIS IS
APPROACHING 2 STANDARD DEVIATIONS ABOVE CLIMATOLOGY. DOWNSTREAM...A
SHORTWAVE AND EXTENSIVE CONVECTION CONTINUES TO MOVE EASTWARD OUT OF
THE CENTRAL PLAINS TOWARD THE MIDDLE MISSISSIPPI VALLEY WITH WEAK
SUBSIDENCE EVIDENT BEHIND IT. VISIBLE SATELLITE REVEALS SOME
MID-HIGH LEVEL CLOUDS LEFT IN THE WAKE OF OVERNIGHT CONVECTION AND
THIS COULD POTENTIALLY LIMIT DIABATIC HEATING SOME THIS AFTERNOON
WITH A TREND TOWARD PARTIAL CLEARING IN THE FAR SOUTH TEXAS
PANHANDLE. SUBJECTIVE SURFACE ANALYSIS AT 18Z SHOWS A WEAK COLD
FRONT/COMPOSITE OUTFLOW ORIENTED NORTHEAST TO SOUTHWEST FROM NEAR
WHEELER TO JUST SOUTH OF CANYON. STORMS HAVE ALREADY FORMED NEAR
CLOVIS AND CU/TCU HAS RECENTLY FORMED NEAR THIS BOUNDARY FURTHER
EAST ACROSS THE FAR SOUTHERN PORTION OF OUR AREA. THIS SHOULD BE THE
INITIAL FOCUS WITH MORE WIDESPREAD CONVECTION OCCURRING LATER THIS
EVENING.
THE TENDENCY OF MID LEVEL HEIGHTS WILL BE TO FALL SLIGHTLY AS UPPER
RIDGE DEAMPLIFIES AND THIS SHOULD SUPPORT GREATER COVERAGE OF
CONVECTION THAN HAS BEEN SEEN IN PREVIOUS DAYS. PRESENCE OF
ANOMALOUS MOISTURE COMBINED WITH SLOW STORM MOTIONS RAISES CONCERN
FOR FLASH FLOODING. FLASH FLOOD GUIDANCE IS AT OR ABOVE CURRENT QPF
OUTPUT FROM MOST GUIDANCE. IN THE ABSENCE OF A WELL DEFINED
SHORTWAVE TO FOCUS DEVELOPMENT BELIEVE THAT THE IMPACTS WOULD BE
LOCALIZED. SOME OF THE SHORT RANGE HI-RES GUIDANCE AMOUNTS ARE MORE
AGGRESSIVE BUT THERE IS SOME QUESTION ABOUT HOW MUCH OF THIS IS
INFLUENCED BY THE BAD AWOS OBSERVATION AT PLAINVIEW/KPVW. THIS IS
GETTING INTO THE RAP AND HAS CONSISTENTLY RESULTED IN A SPURIOUS
7000+ CAPE BULLSEYE IN THE SOUTH TEXAS PANHANDLE THE LAST SEVERAL
DAYS. CAM GUIDANCE NESTED WITHIN THE RAP SUCH AS THE HRRR MAY BE
EXAGGERATED WITH CONVECTIVE COVERAGE AND QPF AS A RESULT.
SEVERE THUNDERSTORMS ARE A SECONDARY CONCERN TODAY ALTHOUGH DEEP
LAYER SHEAR SHOULD BE TOO WEAK TO SUPPORT SUSTAINED UPDRAFTS. SEVERE
EPISODES SHOULD BE BRIEF AND MARGINAL. MID LEVEL LAPSE RATES ARE NOT
PARTICULARLY STEEP WHICH IS TYPICAL FOR THIS MONSOON PATTERN BUT ARE
STEEP ENOUGH TO SUPPORT AROUND 1000 J/KG CAPE IN THE HAIL GROWTH
ZONE. ISOLATED OCCURRENCES OF MARGINALLY SEVERE HAIL ARE POSSIBLE
BUT MODERATE INSTABILITY AND WEAK SHEAR SUPPORTING FAIRLY INTENSE
BUT VERTICAL UPDRAFTS WITH WATER LOADING BENEATH STEEPENING LOW
LEVEL LAPSE RATES SHOULD SUPPORT PRIMARILY A WIND THREAT FROM BRIEF
DOWNBURSTS LATE THIS AFTERNOON THROUGH AT LEAST MID EVENING.
OVERNIGHT...WEAK ASCENT IS DEPICTED BY THE MODELS ON THE 315K
SURFACE WHICH IS FAIRLY MOIST AND THIS SHOULD BE ENOUGH TO SUSTAIN
CHANCES FOR CONVECTION INTO THE NIGHT AND IN A WEAKENED STATE
PROBABLY EVEN INTO THE MORNING HOURS ESPECIALLY ACROSS THE EAST.
SIMILAR CHALLENGES TO TODAY ARE EXPECTED TOMORROW WITH OVERNIGHT
CONVECTION AND MESOSCALE BOUNDARIES/RESIDUAL CLOUDS MAKING SPATIAL
AND TEMPORAL DETAILS UNCLEAR AT THIS POINT. FORECAST CONFIDENCE
SHOULD INCREASE LATER TONIGHT AND BY MORNING AS WE MONITOR HOW
EVENING/OVERNIGHT CONVECTION EVOLVES. STARTING WEDNESDAY MID LEVEL
HEIGHTS RISE AS UPPER HIGH BUILDS NORTH/NORTHWESTWARD ONCE AGAIN
RESULTING IN DRY WEATHER AND WARMER TEMPERATURES THROUGH AT LEAST
THE END OF THE WEEK. TOWARD SATURDAY MEDIUM RANGE GUIDANCE CONSENSUS
IS FOR RIDGE FLATTENS AGAIN AND MEAN WEST-NORTHWESTERLY FLOW MAY BE
ENOUGH FOR CONVECTION TO MOVE INTO AT LEAST WESTERN AND NORTHERN
SECTIONS.
BRB
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
18/11
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
433 AM EDT TUE JUL 21 2015
.SYNOPSIS...
A COLD FRONT THAT EXTENDED FROM ONTARIO TO THE CENTRAL UNITED
STATES EARLY THIS MORNING WILL MOVE SOUTHEAST TODAY AND TONIGHT
AND WILL TRAIL FROM THE CAROLINA COAST INTO THE SOUTHERN PLAINS BY
WEDNESDAY MORNING. HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT AND
WILL COVER THE MID ATLANTIC REGION ON THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM EDT TUESDAY...
A SHORT WAVE CROSSING THE OHIO VALLEY WAS GENERATING CLUSTERS OF
SHOWERS AND THUNDERSTORMS FROM WEST VIRGINIA INTO NORTHERN
TENNESSEE. SHORT TERM GUIDANCE...INCLUDING THE LAST COUPLE RUNS OF
THE HRRR HAS THIS PRECIPITATION MOVING ACROSS THE WESTERN COUNTY
WARNING AREA BEFORE 8AM/12Z. A MAJORITY OF THESE SHOWERS AND
THUNDERSTORMS WILL IMPACT THE WESTERN AND NORTHERN COUNTY WARNING
AREA THIS MORNING AND ARE EXPECTED TO MOVE EAST BUT WEAKEN AS THEY
CROSS THE BLUE RIDGE.
A COLD FRONT TRAILED FROM ONTARIO TO CENTRAL MISSOURI EARLY THIS
MORNING. THIS FRONT WILL MOVE SOUTHEAST TODAY AND TONIGHT. SHOWERS
AND THUNDERSTORMS WILL DEVELOP ALONG THE FRONT THIS AFTERNOON
WHICH WILL RESULT IN ADDITIONAL THUNDERSTORMS IN THE FORECAST AREA
THIS AFTERNOON AND EVENING. HAVE USED THE TIMING OF THE GFS WHICH WAS
BRINGING THE FRONT THROUGH THE FORECAST AREA BEFORE MIDNIGHT...
SLIGHTLY FASTER THAN THE NAM GUIDANCE. SO INCREASED THE
PROBABILITY OF PRECIPITATION FOR MOST LOCATIONS TODAY...AND
REMOVED THE CHANCE OF RAIN LATE TONIGHT BEHIND THE FRONT. THREAT
FOR STORMS BECOMING SEVERE WILL BE LIMITED BY MODEST AMOUNTS OF
INSTABILITY AND SHEAR. BEST CHANCE IS IN THE PIEDMONT LATE THIS
AFTERNOON AND EVENING WHEN THE FRONT SHIFTS INTO THE LEE TROF.
WILL HAVE CLEARING BEHIND THE FRONT EAST OF THE BLUE RIDGE
OVERNIGHT...BUT UPSLOPE WINDS AND RESIDUAL LOW LEVEL MOISTURE WILL
HOLD CLOUDS IN THE WESTERN UPSLOPE AREAS THROUGH EARLY WEDNESDAY
MORNING.
STARTING OUT MILD THIS MORNING SO EVEN WITH THE CLOUD COVER AND
PRECIPITATION TEMPERATURES WILL RISE INTO THE 80S. STAYED CLOSE TO
BLEND OF MAV/MET GUIDANCE FOR MAXIMUM TEMPERATURES TODAY. HEAT
INDEX VALUES WILL BE AROUND 100 FOR A COUPLE HOURS IN THE PIEDMONT
THIS AFTERNOON...NOT HIGH ENOUGH OR LONG ENOUGH TO SUPPORT ANY
ADVISORY.
AIR MASS BEHIND THE FRONT IS SLIGHTLY COOLER WITH LOWS TONIGHT A
CATEGORY OR TWO BELOW TEMPERATURES THIS MORNING. THE MORE
SIGNIFICANT CHANGE IS SURFACE DEW POINTS DROPPING INTO THE UPPER
50S IN THE NORTHERN COUNTY WARNING AREA ALONG WITH PRECIPITABLE
WATER VALUES DROPPING BELOW ONE HALF INCH.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 310 AM EDT TUESDAY...
BROAD UPPER TROUGH CENTERED AROUND JAMES BAY EXTENDING ACROSS THE
EASTERN GREAT LAKES AND EASTERN CANADIAN WILL TRAVEL EAST DURING
THE PERIOD...AS AN UPPER RIDGE AMPLIFIES IN THE CENTRAL UNITED
STATES. THE SURFACE FRONTAL BOUNDARY WILL PUSH SOUTH OF OUR AREA
AND STALL...BUT SERVE AS A FOCUS FOR DIURNALLY DRIVEN CONVECTION.
DECREASED POPS WEDNESDAY...BUT STILL KEPT SOME ISOLATED TO WIDELY
SCATTERED POPS IN THE WEST WEDNESDAY AFTERNOON ACROSS THE HIGHER
TERRAIN. HIGH TEMPERATURES WEDNESDAY WILL VARY FROM THE THE UPPER
70S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. HELD ON
TO AN ISOLATED SHOWERS ACROSS SOUTHERN PORTIONS OF THE FORECAST
AREA ON WEDNESDAY NIGHT...AS A WAVE OF LOW PRESSURE DEVELOPS ALONG
THE STALLED FRONTAL ZONE WEDNESDAY NIGHT. LOW TEMPERATURES
WEDNESDAY NIGHT WILL RANGE FROM THE MID 50S IN THE MOUNTAINS TO
THE UPPER 60S IN THE PIEDMONT.
AN UPPER LEVEL DISTURBANCE WILL TRACK ALONG THE FRONT/BAROCLINIC
ZONE FROM WEST TO EAST THURSDAY. THERE IS THE POTENTIAL THAT THE
FRONT MAY LIFT NORTH AS WEAK WAVES OF LOW PRESSURE RIDE ALONG THE
BOUNDARY. MOISTURE WILL TRY AND SURGE BACK INTO THE PIEDMONT AND
NORTHWEST NORTH CAROLINA MOUNTAINS TO SOME DEGREE. THE PLACEMENT OF
THE LOW CENTER LOOKED A LITTLE FURTHER SOUTH AND EAST ON THIS MODEL
RUN. HOWEVER...GIVEN TIME OF YEAR AND DIFFERENTIAL HEATING...ALLOWED
FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAINLY ACROSS
THE PIEDMONT. AT ANY RATE...THE THREAT FOR SIGNIFICANT OR WIDESPREAD
CONVECTION AND SEVERE STORMS WILL REMAIN VERY LOW. HIGHS ON THURSDAY
WILL CLIMB INTO THE UPPER 70S IN THE WEST TO THE THE UPPER 80S IN
THE EAST. AS HIGH PRESSURE NUDGES IN FROM THE NORTHWEST...DRIER AIR
PUSHES ACROSS THE AREA THURSDAY NIGHT. LOW TEMPERATURES THURSDAY
NIGHT WILL DROP INTO THE MID 50S IN THE MOUNTAINS TO THE NEAR 70
DEGREES IN THE PIEDMONT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 350 PM EDT MONDAY...
THE BROAD NORTHEAST U.S./SOUTHEAST CANADIAN UPPER TROUGH WILL
CONTINUE TO SHIFT SLOWLY EAST THROUGH THE PERIOD. A STRONG
SUBTROPICAL RIDGE ANCHORED ACROSS TEXAS...WILL AMPLIFY INTO THE
GREAT LAKES...WITH A NOSE OF 850MB TEMPS EXCEEDING +20C
ACCOMPANYING IT. OUR REGION WILL LARGELY REMAIN UNDER NORTHWEST
FLOW ALOFT THROUGH THE PERIOD. MOST MODELS TAKE THE REMNANT
FRONTAL BOUNDARY FROM MID-WEEK AND THE ASSOCIATED WEAKNESS IN THE
UPPER-LEVELS SOUTHWARD INTO THE SOUTHEAST STATES...WHERE IT
APPEARS DESTINED TO CUTOFF AND LINGER IN THE EASTERN
GULF/FL/WESTERN ATLANTIC REGION. AS IT LINGERS IN THIS REGION INTO
NEXT WEEK...IT WILL NEED TO BE CAREFULLY MONITORED FOR ANY
POTENTIAL TROPICAL CHARACTERISTICS. GIVEN THE
AMPLIFYING/STRENGTHENING NW FLOW ALOFT...WE SHOULD SEE THE FRONTAL
BOUNDARY/BAROCLINIC ZONE PUSHED FAR ENOUGH SOUTH TO SHUT OFF THE
CONVECTION SATURDAY...OUTSIDE ISOLATED MOUNTAIN SHOWERS. BY
SUNDAY...A SHORT WAVE AND ASSOCIATED WEAK FRONT MOVES INTO THE
REGION FROM THE NORTHWEST...WHICH SHOULD INCREASE THE CHANCE FOR
SHOWERS/STORMS. THIS FEATURE MOVES EAST OF THE REGION MONDAY AS
THE UPPER RIDGE CONTINUES TO BUILD INTO THE REGION FROM THE WEST.
500MB HEIGHTS ARE SLATED TO RISE ABOVE 590DM AND 850MB TEMPS WILL
BEGIN TO CREEP ABOVE +20C ONCE AGAIN...ESPECIALLY IN THE WEST.
CONVECTION LOOKS TO BE MINIMAL PAST SUNDAY AT THIS POINT.
TEMPERATURES APPEAR DESTINED TO RETURN TO ABOVE NORMAL LEVELS BY
THE WEEKEND.
A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE
WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS
THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE
NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES
TO REACH THE REGION.
850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C
ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP
INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU
MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP
BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY
BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS
BY THE WEEKEND.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
AS OF 140 AM EDT TUESDAY...
05Z OBSERVATIONS INDICATED IFR STRATUS WAS DEVELOPING ON THE
WESTERN SLOPES OF THE APPALACHIANS. HAVE IFR CEILINGS IN AT KBLF
AND KLWB UNTIL THE SHOWERS AND THUNDERSTORMS COMING OUT OF WEST
VIRGINIA AND KENTUCKY ARRIVE IN THE AREA. TIMING OF THE
PRECIPITATION IN THE MODELS HAS BEEN CONSISTENT. EXPECT THE
SHOWERS AND THUNDERSTORMS TO REACH KBLF AND KLWB BETWEEN 09Z/5AM
AND 11/7AM.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL FORM THIS AFTERNOON OVER
THE REGION AHEAD OF A COLD FRONT. A FEW OF THESE STORMS WILL
BECOME STRONG AND MAY PRODUCE GUSTY WINDS.
THE COLD FRONT WILL PASS ACROSS THE FORECAST AREA THIS EVENING
WITH SURFACE WINDS TURNING TO THE NORTHWEST. MEDIUM CONFIDENCE OF
MORE MVFR CLOUDS ON THE WESTERN SLOPES OF THE MOUNTAINS OVERNIGHT.
EXTENDED AVIATION DISCUSSION...
THE COLD FRONT WILL ADVANCE SOUTH OF THE FORECAST AREA FOR
WEDNESDAY AND THURSDAY...BUT THEN BUCKLES NORTHWARD ON FRIDAY. SO
FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE PATCHY FOG
WEDNESDAY AND THURSDAY MORNING IN THE BCB/LWB AREA PENDING HOW
DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS
POSSIBLE FRIDAY AND SATURDAY IN THE MOUNTAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...KK
LONG TERM...RAB
AVIATION...AMS/NF
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1125 PM CDT MON JUL 20 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 248 PM CDT MON JUL 20 2015
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT
ANALYSIS SHOWED A DEEP TROUGH PLOWING INTO BRITISH COLUMBIA...
RIDGING OVER THE NORTHERN U.S. ROCKIES INTO ALBERTA /
SASKATCHEWAN...AND TROUGHING FROM NORTHERN ONTARIO INTO NORTHERN
MN. A SHORTWAVE WAS ALSO EVIDENT OVER EASTERN IOWA...WHICH
COMBINED WITH A SURGE OF 850MB MOISTURE TRANSPORT...MID LEVEL
FRONTOGENESIS AND PRECIPITABLE WATER AROUND 1.5 INCHES HELPED
BRING SHOWERS AND SOME THUNDERSTORMS TO THE SOUTHEAST HALF OF THE
FORECAST AREA THIS MORNING. A SURFACE COLD FRONT WAS ALSO MARCHING
THROUGH THE FORECAST AREA...NOW FROM GREEN BAY TO OELWEIN.
INSTABILITY HAS BEEN BEEN LIMITED DUE TO MORNING CLOUDS/SHOWERS...
BUT RAP MESOANALYSIS SUGGESTS UP TO 1000 J/KG OF MLCAPE EXISTS
ALONG THE FRONT. THIS INSTABILITY HAS RESULTED IN SOME ISOLATED
SHOWERS ALONG THE FRONT...WITH WEAK LOW LEVEL CONVERGENCE
PREVENTING MORE DEVELOPMENT. IN THE WAKE OF THE FRONT...
PRECIPITABLE WATER DROPS DOWN TO 0.75 INCHES...RESULTING IN DRYING
OF THE AIR INCLUDING AT THE SURFACE. HOWEVER...A FEW SHOWERS WERE
NOTED IN THE COLD POOL REGION UNDERNEATH THE TROUGH IN FAR
NORTHERN MN/ONTARIO. BREEZY CONDITIONS NOTED TOO BEHIND THE FRONT
WITH TIGHTER PRESSURE GRADIENT AND DAYTIME MIXING. THESE NORTHWEST
WINDS WERE DRIVING IN COLDER AIR...NOTED BY 850MB TEMPS OF 16-18C
AHEAD COMPARED TO 8-10C OVER NORTHERN MN. SURFACE RIDGE RESIDED
WELL TO THE WEST OVER THE WESTERN DAKOTAS.
ANY SHOWERS/STORMS THE DEVELOP ALONG THE COLD FRONT OVER THE
SOUTHEAST THIRD OF THE FORECAST AREA SHOULD EXIT BY 23/00Z AS THE
FRONT CONTINUES TO PUSH SOUTHEAST. AFTER THAT...COOLER...DRIER AIR
REMAINS ON TRACK TO DROP INTO THE REGION FOR TONIGHT AND MONDAY. THE
EXTENSION OF THE UPPER TROUGH IN NORTHERN MN LOOKS TO SWING ACROSS
ALL OF WI TONIGHT AND INTO THE EASTERN GREAT LAKES ON TUESDAY. THIS
UPPER TROUGH WILL HELP DRIVE 850MB TEMPS DOWN TO 10-11C BY 12Z TUE.
ANY OF THE SHOWERS ACCOMPANYING THE COLD POOL LOOK TO STAY WELL
NORTH AND DIMINISH WITH LOSS OF DAYTIME HEATING THIS EVENING. SKIES
WILL CLEAR OUT QUICKLY THIS EVENING AS DRY AIR INFILTRATES AND LOSS
OF DAYTIME HEATING DISSIPATES CUMULUS. IF NOT FOR A PERSISTENT
NORTHWEST BREEZE WE COULD SEE A DECENT VALLEY FOG EVENT.
NEVERTHELESS...THE MORE SHELTERED SMALLER VALLEYS LIKE THE WISCONSIN
WILL FOG. THE TYPICAL COLD SPOTS SHOULD ALSO RADIATE NICELY AND DIP
DOWN INTO THE UPPER 40S. THE REST OF THE REGION SHOULD SEE LOWS IN
THE 50S. PLENTY OF SUN ON TRACK FOR TUESDAY WITH DRY AIR IN PLACE
AND HIGH PRESSURE BUILDING IN. WITH 850MB TEMPS CLIMBING TO 12-14C
BY 00Z WEDNESDAY THANKS TO DEEP MIXING...HIGHS IN THE 70S SHOULD BE
COMMON WITH LOW 80S FOUND IN RIVER VALLEYS AND SANDY SOIL AREAS. THE
DEEP MIXING ALSO SHOULD PROMOTE IN QUITE A BIT LOWER DEWPOINTS
COMPARED TO TODAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 248 PM CDT MON JUL 20 2015
UPPER RIDGING SEEN OVER THE NORTHERN ROCKIES AND SASKATCHEWAN /
ALBERTA IS PROGGED TO GRADUALLY MOVE EAST INTO THE REGION OVER
THE NEXT FEW DAYS...MOVING OVERHEAD AROUND 12Z FRIDAY. SUBSIDENCE
WITH THIS UPPER RIDGING BUILDING IN...COMBINED WITH THE FRONT
TODAY PUSHING ALL THE MOISTURE SOUTH OF I-70 RESULT IN DRY
CONDITIONS FOR THE MOST PART THROUGH THURSDAY NIGHT.
HOWEVER...THERE IS A BAND OF MID LEVEL FRONTOGENESIS THAT LOOKS TO
SET UP LATE WEDNESDAY INTO THURSDAY...SITUATED FROM CENTRAL MN
INTO NORTH CENTRAL WI. THE 20.12Z NAM/ECMWF/CANADIAN HAVE BACKED
OFF ON THE INTENSITY AND THUS QPF PRODUCTION TO THE POINT OF
NEARLY DRY. ON THE OTHER HAND THE 20.12Z GFS STILL PRODUCES SOME
QPF. BELIEVE THE GFS MIGHT BE OVERLY MOIST...A KNOWN BIAS...AND
THEREFORE HAVE TRENDED DRY FOR TAYLOR/CLARK COUNTIES DURING MID-
WEEK. TEMPERATURES WEDNESDAY AND THURSDAY WILL BE ON A WARMING
TREND AS 850MB TEMPS EVENTUALLY CLIMB TO 14-16C BY 00Z FRI. MAY
HAVE TO CONTEND WITH VALLEY FOG TUESDAY NIGHT WITH LIGHT
WINDS...BUT THERE ARE HINTS OF SOME CLOUDS PASSING THROUGH.
THEREFORE...HAVE KEPT MUCH FOG OUT.
FOR FRIDAY THROUGH MONDAY...THE MAIN FEATURE OF INTEREST IS A
PORTION OF THE DEEP TROUGH IN BRITISH COLUMBIA THAT DROPS THROUGH
THE REGION LATE FRIDAY THROUGH SATURDAY EVENING. 20.12Z
GFS/ECMWF/CANADIAN ALL WANT TO DEVELOP CONVECTION IN WARM ADVECTION
AHEAD OF THE SHORTWAVE TROUGH...THEN ADDITIONAL CONVECTION AS THE
COLD FRONT ASSOCIATED WITH THE TROUGH COMES THROUGH. SOME TIMING
ISSUES THUS PRECIPITATION CHANCES ARE SPREAD OUT...THOUGH IF TRENDS
CONTINUE SHOULD BE ABLE TO PULL OUT CHANCES FOR SATURDAY NIGHT AND
EVEN SATURDAY AFTERNOON. IF THE GFS PANS OUT WE MIGHT HAVE TO DEAL
WITH SOME SEVERE STORMS...PARTICULARLY FRIDAY NIGHT...BUT THE ECMWF
WOULD KEEP ITS SEVERE THREAT FARTHER TO THE SOUTHWEST. SOMETHING TO
WATCH. DRIER WEATHER THEN FOLLOWS FOR SUNDAY AS UPPER AND SURFACE
RIDGING BEGINS BUILDING BACK IN. PERHAPS ANOTHER INTERESTING PERIOD
COULD SETUP SUNDAY NIGHT AND MONDAY...PARTICULARLY IN THE ECMWF...AS
A SHORTWAVE COMES DOWN THE RIDGE BUILDING IN. FOR NOW JUST HAVE SOME
LOW CHANCES ON MONDAY PER CONSENSUS BUT THESE MAY NEED ADJUSTMENT.
OVERALL TEMPERATURES LOOK TO STAY AT OR ABOVE SEASONABLE
NORMALS...AND SOME OF THE HIGHS IN THE CURRENT FORECAST ALTHOUGH
NEAR CONSENSUS COULD END UP BEING A LITTLE HIGHER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1125 PM CDT MON JUL 20 2015
A PERIOD OF GOOD VFR CONDITIONS EXPECTED THE REST OF TONIGHT THRU
TUE EVENING AS DRIER AND COOLER CANADIAN HIGH PRESSURE SETTLES INTO
THE UPPER MIDWEST. NORTHWEST WINDS OF 5 TO 8 KTS WILL CONTINUE THRU
TONIGHT...LIMITING ANY LATE NIGHT/EARLY MORNING BR POTENTIAL AT
SITES LIKE KLSE. A FEW/SCT 5K-6K FT DIURNAL CUMULUS EXPECTED WITH
DIURNAL WARMING/MIXING LATE TUE MORNING THRU TUE AFTERNOON...ALONG
WITH SOME INCREASE OF THE NORTHWEST WINDS WITH DEEPER DIURNAL
MIXING. THE SFC RIDGE AXIS WILL APPROACH/PASS TUE EVENING WITH WINDS
BECOMING LIGHT/VARIABLE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
338 AM MDT TUE JUL 21 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 330 AM MDT TUE JUL 21 2015
500 MB ANALYSIS SHOWS A WEAK SHORTWAVE ACROSS SOUTHWESTERN WYOMING
WITH WIDESPREAD MID LEVEL CLOUDS AND SCATTERED SHOWERS TO THE
EAST OF THE LARAMIE RANGE. THE WEAK UPPER LEVEL DISTURBANCE IS
PROGGED TO PASS OVERHEAD THROUGH THE DAY. THE HRRR AND GFS/NAM
SHOW SHOWERS INCREASING IN COVERAGE ACROSS THE PLAINS THROUGH THE
MORNING...AND ESPECIALLY ACROSS THE NEBRASKA PANHANDLE.
INSTABILITY INCREASES BY AROUND 18Z WITH CAPE VALUES OF 750 TO
1250 J/KG THROUGH THE AFTN. WILL KEEP THE HIGH POPS (40 TO 60
PERCENT) GOING THROUGH THE LATE AFTN ACROSS THE PLAINS AS THE
SHORTWAVE INTERACTS WITH PLENTIFUL SUBTROPICAL MOISTURE ALONG WITH
DECENT LOW LEVEL MOISTURE. MAIN CONCERN WITH THE CONVECTION WILL
BE HEAVY RAIN WITH PW VALUES ABOVE NORMAL (ABOVE 1 INCH). MAY ALSO
BE SOME SMALL HAIL WITH BULK SHEAR AROUND 30 KT...HOWEVER CONFIDENCE
IS NOT HIGH ENOUGH TO INCLUDE IN FCST. TEMPS WILL BE COOLER TODAY
WITH THE WIDESPREAD CLOUD COVER. THE RAIN WILL TAPER OFF BY THE
LATE EVENING AS SUBSIDENCE KICKS IN BEHIND THE SHORTWAVE.
CHANCES FOR STORMS WILL BE LESS ON WEDNESDAY AS HEIGHTS ALOFT BEGIN
TO RISE. HOWEVER...700 TO 500 MB FLOW IS STILL SOUTHWESTERLY WITH
MODEST SUBTROPICAL MOISTURE STREAMING INTO WYOMING AND PW VALUES
OF 0.75 TO 1 INCH. COULD SEE SCATTERED AFTN STORMS DEVELOP OVER
MUCH OF SOUTHEAST WYOMING WITH THE MAIN THREAT BEING BRIEF HEAVY
RAIN. INSTABILITY IS QUITE A BIT LESS THAN TODAY SO SMALL HAIL IS
NOT MUCH OF A THREAT. HIGH TEMPS WILL RISE 5 TO 10 DEGREES. MUCH
MORE DRYING IS STILL PROGGED FOR THURSDAY AS THE SUBTROPICAL
MOISTURE PLUME SHIFTS OUT OF SOUTHERN WYOMING. SOUTHWEST WINDS
WILL BE BREEZY TO THE WEST OF THE LARAMIE RANGE AS A SFC TROUGH
DEVELOPS OVER WESTERN SOUTH DAKOTA.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 AM MDT TUE JUL 21 2015
THE 00Z MEDIUM RANGE MODELS ARE IN AGREEMENT DEPICTING A LARGE
SCALE UPPER RIDGE OVER THE NATION`S MIDSECTION...WITH THE MORE
ACTIVE WESTERLIES CONFINED ACROSS THE NORTHERN TIER THROUGH THE
WEEKEND. THE FLOW ALOFT WILL BE WEST TO SOUTHWEST...WITH MOST OF THE
SUBTROPICAL MOISTURE TO THE SOUTH AND WEST OF THE REGION. THE
ECMWF...AND TO A LESSER EXTENT THE GFS...HINT AT SOME MOISTURE
TRYING TO SNEAK NORTHWARD ACROSS THE HIGH PLAINS SATURDAY AND SUNDAY
FOR ISOLATED AFTERNOON/EVENING CONVECTION. IT WILL BE WARM FRIDAY
THROUGH SUNDAY WITH HIGHS FROM THE MID 80S TO LOW 90S. A SURFACE
TROUGH MOVES INTO THE HIGH PLAINS MONDAY...WITH A WEAK SHORTWAVE
PASSING OVERHEAD. THE ECMWF QPF LOOKS OVERDONE COMPARED TO THE
GFS...WITH LOW POPS FOR THE SOUTHEAST WYOMING MOUNTAINS. HIGH
TEMPERATURES MONDAY WILL BE A FEW DEGREES COOLER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 330 AM MDT TUE JUL 21 2015
VFR CEILINGS WILL PREVAIL FOR THE MOST PART THROUGH TONIGHT.
THERE WILL BE BRIEF PERIODS OF MVFR CEILINGS AND VISIBILITY
WITH SHRA AND TSRA AS WELL AS GUSTY WINDS...ESPECIALLY THIS
AFTERNOON AND EARLY EVENING. THE LATEST NAM/SREF MODELS ARE
INDICATING MVFR TO IFR CEILINGS DEVELOPING ACROSS MUCH OF
WESTERN NEBRASKA LATE TONIGHT...AND WILL BE TRENDING THAT
DIRECTION WITH THIS TAF PACKAGE.
&&
.FIRE WEATHER...
ISSUED AT 330 AM MDT TUE JUL 21 2015
MINIMAL FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. SCATTERED
SHOWERS AND THUNDERSTORMS WILL OCCUR TODAY FOR AREAS TO THE EAST
OF THE LARAMIE RANGE. A DRIER AIR MASS WILL MOVE INTO THE REGION
WEDNESDAY AND ESPECIALLY THURSDAY. THURSDAY AFTERNOON...MINIMUM
HUMIDITY VALUES WILL DROP TO 15 TO 25 PERCENT OVER LOWER ELEVATIONS
AND SOUTHWEST WINDS WILL BE BREEZY TO THE WEST OF THE LARAMIE RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...MAJ
AVIATION...MAJ
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
451 AM PDT TUE JUL 21 2015
.SYNOPSIS...LINGERING MOISTURE FROM THE REMNANTS OF DOLORES WILL
RESULT IN A CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE
SOUTHEASTERN PORTIONS OF THE REGION THROUGH THE AFTERNOON.
OTHERWISE...COOLER CONDITIONS CAN BE EXPECTED THROUGH THURSDAY.
DRY WEATHER CONDITIONS AND NEAR NORMAL TEMPERATURES ARE LIKELY FOR
LATE WEEK AND INTO THE UPCOMING WEEKEND.
&&
.DISCUSSION...AS OF 3:00 AM PDT TUESDAY...AFTER A COUPLE OF VERY
WARM AND FAIRLY HUMID DAYS ACROSS OUR REGION TODAY WILL FEEL QUITE
A BIT COOLER. IN FACT...24 HOUR CHANGE PRODUCT ALREADY SHOWS THE
BIG CHANGE WITH ALMOST ALL SPOTS 7 TO 13 DEGREES UNDER VALUES FROM
YESTERDAY ALONG WITH SLIGHTLY LOWER DEW POINTS. SYNOPTICALLY
REMNANTS FROM FORMER HURRICANE DOLORES CONTINUES TO SPIN OFF TO
OUR SOUTHWEST. DUE TO SOME INSTABILITY PLUS MID LEVEL MOISTURE
THERE REMAINS AN OUTSIDE CHANCE OF A FEW SHOWERS OR EVEN A
THUNDERSTORM FIRING UP OVER PARTS OF MONTEREY AND SAN BENITO
COUNTIES. WILL KEEP POPS AROUND 20 PERCENT FOR THAT AREA. FOR THE
REST OF THE CWA LOOK FOR DRY CONDITIONS WITH HIGHS 4 TO 8 DEGREES
COOLER THAN YESTERDAY.
MODELS REMAIN IN GOOD AGREEMENT THAT A LONGWAVE TROF WILL MOVE IN
FROM THE NORTH AND STRETCH FROM NORCAL INTO CENTRAL CANADA
STARTING TONIGHT. THIS FEATURE IS EXPECTED TO REMAIN NEARLY
STATIONARY THROUGH AT LEAST THURSDAY WHICH WILL HELP TO DROP TEMPS
TO COOLER THAN NORMAL VALUES FOR ALMOST ALL SPOTS. SPOTTY COASTAL
DRIZZLE WILL ALSO BE POSSIBLE EACH NIGHT INTO THE MORNING HOURS.
THE TROF WILL LIFT TO THE NORTHEAST FRIDAY AND SATURDAY AS A
RIDGE OF HIGH PRESSURE BUILDS FROM THE SOUTHEAST. THIS WILL HELP
TO PUSH HIGHS CLOSER TO NORMAL BY THE END OF THE WEEK GOING INTO
THE START OF NEXT WEEK.
&&
.AVIATION...AS OF 4:50 AM PDT TUESDAY... A RELATIVELY SHALLOW
MARINE LAYER HAS CREPT INTO THE INLAND VALLEYS THIS MORNING...
LEADING TO LIFR TO MVFR CIGS ACROSS REGIONAL TAF SITES. THE SFO
TO SAC ONSHORE GRADIENT IS MORE THAN TWICE AS LARGE VERSUS 24
HOURS AGO... WHICH CONTRIBUTED TO THE INCREASED ONSHORE PUSH.
LARGE SPREAD OF MODEL OUPUT IS LEADING TO A LOW TO MODERATE
CONFIDENCE FORECAST FOR MORNING MIXOUT TIMES. SATELLITE IMAGERY
SHOWS A DECK OF MID LEVEL CLOUDS LEFT OVER FROM YESTERDAYS SIERRA
CONVECTION ADVANCING FROM THE EAST. HRRR MODEL SUGGESTING THAT A
FEW ISOLATED AREAS OF -RA/DZ MAY BE POSSIBLE FROM THIS DECK...
BUT EXPECT VIRGA TO BE PREDOMINATE WX COND.
VICINITY OF KSFO... LOW TO MODERATE CONFIDENCE. IFR CIGS THROUGH
1630-17Z. MVFR POSSIBLE THROUGH 1730-19Z. ADVANCING MID LEVEL
MOISTURE FROM THE EAST MAY LEAD TO -RA IN THE VICINITY BTWN
15-19Z. ONSHORE WINDS 15-20KT WITH GUSTS TO 25KT THIS AFTERNOON.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS... MODERATE CONFIDENCE. WIDESPREAD IFR
CIGS THROUGH 18Z... WITH LOCAL IFR/MVFR CIGS LINGERING TO 20-21Z.
EARLIER RETURN OF IFR CIGS TONIGHT. ONSHORE WINDS 10 TO 15KT.
&&
.MARINE...AS OF 04:29 AM PDT TUESDAY...NORTHWEST WINDS INCREASE
ACROSS THE COASTAL WATER LATE TODAY AS A DRY TROUGH APPROACHES THE
REGION. THE STRONGEST WINDS ARE EXPECTED OVER THE NORTHERN OUTER
WATERS TONIGHT.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 3 PM
SCA...PT ARENA TO PT REYES 0-10 NM FROM 3 PM
&&
$$
PUBLIC FORECAST: BELL
AVIATION: DRP
MARINE: DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS PUEBLO CO
431 AM MDT TUE JUL 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM MDT TUE JUL 21 2015
...STRONG TO SEVERE STORMS POSSIBLE ACROSS THE EASTERN MTS AND
PLAINS...
CURRENT WATER VAPOR IMAGERY INDICATING INCREASING SOUTH TO SOUTHWEST
FLOW ALOFT ACROSS THE REGION AS A SHORT WAVE TROUGH IS TRANSLATING
ACROSS THE SOUTHERN CALIFORNIA COAST AND SOUTHERN GREAT BASIN AT
THIS TIME. WATER VAPOR IMAGERY IS INDICATING THE MONSOONAL MOISTURE
PLUME ACROSS AT THE SOUTHERN AND CENTRAL ROCKIES WITH MUCH DRIER AIR
WITHIN THE FLOW ALOFT WORKING ITS WAY ACROSS THE DESERT SW AND INTO
WESTERN COLORADO AT THIS TIME. MINOR EMBEDDED DISTURBANCES ARE
EVIDENT WITHIN THE SOUTH TO SOUTHERLY FLOW ACROSS THE SOUTHERN
ROCKIES...WITH AN MCV AND REMNANTS OF LAST NIGHTS MCS CAN ALSO BE
SEEN ACROSS THE OKLAHOMA PANHANDLE AT THIS TIME.
COMPLEX FORECAST THIS MORNING WITH LATEST MODELS...EVEN THE HIGHER
RES HRRR AND RUC...NOT DOING WELL AND CONTINUE TO PRINT OUT
CONVECTIVE QPF BULLSEYES ACROSS THE AREA EARLY THIS MORNING. AT ANY
RATE...SHOULD SEE LEE TROUGHING ACROSS THE I-25 CORRIDOR THROUGH THE
MORNING AND EARLY AFTERNOON AS SOUTHWEST FLOW ALOFT CONTINUES TO
INCREASE AHEAD OF SOUTHERN CALIFORNIA SHORT WAVE. THIS WILL LEAD TO
INCREASING SOUTH TO SOUTHEAST LOW TO MID LEVEL UPSLOPE FLOW ACROSS
THE EASTERN MTS THROUGH THE UPPER ARKANSAS RIVER VALLEY. WITH AMPLE
MOISTURE AND POSSIBLE ADDED LIFT FROM THE SOUTHERN ROCKIES MINOR
DISTURBANCES LIFTING NORTH ACROSS SOUTH CENTRAL COLORADO...SHOULD
SEE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS OVER AND NEAR
THE HIGHER TERRAIN THROUGH THE LATE MORNING AND AFTERNOON.
FURTHER EAST ACROSS THE I-25 CORRIDOR AND THE SOUTHEASTERN
PLAINS...SUBSIDENCE ON THE BACKSIDE OF THE OK PANHANDLE MCV COULD
KEEP CONVECTION AT BAY THROUGH THE MORNING...WITH COOL UPSLOPE FLOW
ALSO POSSIBLY KEEPING CONDITIONS TOO STABLE THIS AFTERNOON...LEADING
TO EASTERN MOUNTAIN STORMS WEAKENING AS THEY PUSH EAST OFF THE
HIGHER TERRAIN. HOWEVER...IF ENOUGH INSTABILITY CAN BE
GENERATED...THERE WILL BE ENOUGH SHEAR FOR SUPERCELL DEVELOPMENT
SUPPORTING STRONG TO SEVERE STORMS PRODUCING LARGE HAIL TO AROUND AN
INCH IN DIAMETER AND DAMAGING WIND GUSTS IN EXCESS OF 60 MPH.
STORMS THAT DO DEVELOP WILL ALSO BE CAPABLE OF PRODUCING HEAVY
RAINFALL...THOUGH WITH INCREASING FLOW ALOFT...STORMS WILL BE MOVING
AT A GOOD CLIP TO LIMIT FLASH FLOODING POTENTIAL. THE ONE CAVET WILL
BE THE POTENTIAL FOR TRAINING STORMS...ESPECIALLY ACROSS THE EASTERN
MTS AND PALMER DVD...WITH SOUTH TO SOUTHEAST LOW AND MID LEVEL FLOW.
WITH THAT SAID...CONSIDERED ISSUING A FLASH FLOOD WATCH FOR THE BURN
SCARS IN EL PASO COUNTY...BUT THERE REMAINS TOO MANY QUESTION ON
GENERATING ENOUGH INSTABILITY TO ISSUE AT THIS TIME.
DRIER AIR ALOFT CONTINUES TO WORK INTO THE AREA TONIGHT AS SHORT
WAVE TRANSLATES ACROSS THE CENTRAL ROCKIES. LEE TROUGHING LIFTS OUT
ACROSS THE EASTERN PLAINS AND COULD BE A FOCUS CONVECTION THIS
EVENING WITH STORMS DIMINISHING FROM WEST TO EAST THROUGH THE LATE
EVENING AND OVERNIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 346 AM MDT TUE JUL 21 2015
WESTERLY MID/UPPER LEVEL FLOW ON WED ALLOWS PLUME OF RATHER DEEP
DRY AIR TO SPREAD ACROSS THE STATE...LEADING TO A PRONOUNCED
DOWNTURN IN CONVECTION ALL AREAS WED AFTERNOON AND EVENING. STILL
SOME SHALLOW RESIDUAL MOISTURE HANGING ON OVER THE
MOUNTAINS...WHICH WILL LEAD TO SOME WEAK TSRA WED AFTERNOON OVER
THE HIGHER TERRAIN...THOUGH OVERALL STRENGTH/COVERAGE OF STORMS
WILL BE PALTRY. MAX TEMPS WED WILL CLIMB CONSIDERABLY WITH DRY
AIR AND DOWNSLOPE GRADIENT...AND 90S WILL REAPPEAR ACROSS MOST OF
THE SOUTHEAST PLAINS. DRY AIR PERSISTS ON THU WITH A REPEAT OF
WEAK MOUNTAIN CONVECTION IN THE AFTERNOON...WITH MAX TEMPS ADDING
ANOTHER 3-5F OVER THE PLAINS...1-3F WARMER ACROSS THE HIGHER
ELEVATIONS. WESTERLY FLOW ALOFT INCREASES FRI AS UPPER WAVE MOVES
THROUGH THE NORTHERN ROCKIES INTO THE HIGH PLAINS BY EVENING. WEAK
COLD FRONT WILL PUSH THROUGH THE PLAINS DURING THE DAY...BUT
MOISTURE IS LACKING AND POST FRONTAL UPSLOPE IS INITIALLY WEAK...SO
DOUBTFUL BOUNDARY WILL HAVE MUCH IMPACT ON PRECIP CHANCES...AND
WILL KEEP JUST THE USUAL LOW POPS FOR ISOLATED STORMS OVER THE
MOUNTAINS.
UPPER RIDGE OVER TEXAS BEGINS TO SLOWLY DRIFT EASTWARD OVER THE
WEEKEND...WHICH WILL ALLOW SOUTHERLY FLOW TO REDEVELOP OVER THE
DESERT SW...LEADING TO A RENEWED INFLUX OF MOISTURE AND INCREASING
TSRA CHANCES MOST LOCATIONS BEGINNING SAT AFTERNOON/EVENING AND
CONTINUING INTO SUN. RIDGE THEN REMAINS EAST OF THE AREA NEXT
WEEK...WITH FAIRLY STRONG MONSOON TAP MON PERSISTING INTO MID
WEEK. MAX TEMPS WILL LIKELY PEAK ON FRI...THEN DRIFT SLOWLY
DOWNWARD THROUGH THE WEEKEND INTO NEXT WEEK AS AIR MASS MOISTENS
AND CONVECTIVE CLOUDINESS SHAVES A FEW DEGF OFF OF DAYTIME
READINGS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 346 AM MDT TUE JUL 21 2015
PATCHY MVFR AND IFR LOW CLOUDS REMAIN A CONCERN AT COS AND ALS
THROUGH DAYBREAK...WITH AMPLE MOISTURE IN PLACE AND DEVELOPING
UPSLOPE FLOW ACROSS THE EASTERN PLAINS.
WIDESPREAD PRECIP IS EXPECTED OVER AND NEAR THE HIGHER TERRAIN WITH
MONSOONAL MOISTURE IN PLACE ACROSS THE AREA AND AN UPPER LEVEL
SYSTEM MOVING ACROSS THE AREA THROUGH THE AFTERNOON AND EVENING.
STORMS THAT DEVELOP WILL PRODUCE LOCALLY HEAVY RAINFALL AND PRODUCE
MVFR AND LOCAL IFR CONDITIONS AT TERMINALS. COULD ALSO SEE STRONG TO
SEVERE STORMS ACROSS THE I-25 CORRIDOR AND EASTERN PLAINS THIS
AFTERNOON AND EVENING. IF THERE IS ENOUGH INSTABILITY...LARGE HAIL
TO AROUND AND INCH IN DIAMETER AND GUSTY OUTFLOW WINDS TO AROUND 60
MPH WILL BE POSSIBLE...ESPECIALLY AT COS. DRIER WESTERLY FLOW WORKS
INTO THE AREA LATER TONIGHT...WITH STORMS DIMINISHING FROM WEST TO
EAST THROUGH THE EVENING HOURS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MW
LONG TERM...PETERSEN
AVIATION...MW
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1028 AM CDT TUE JUL 21 2015
.UPDATE...
ISSUED AT 1028 AM CDT TUE JUL 21 2015
HIGH PRESSURE BUILDING INTO THE MIDWEST BEHIND A COLD FRONT THAT
PASSED THROUGH CENTRAL IL OVERNIGHT WILL BRING COOLER AND DRIER
CONDITIONS TODAY...ALONG WITH LIGHT NORTHERLY BREEZES TO AROUND 10
MPH. SKIES WILL BE MOSTLY CLEAR...ALTHOUGH SOME SCATTERED
AFTERNOON CLOUD COVER WILL DEVELOP. AN INVERSION AROUND 5000 FEET
AGL WILL LIMIT VERTICAL DEVELOPMENT OF CLOUDS...SO NO
PRECIPITATION EXPECTED. HIGHS STILL LOOK ON TRACK TO REACH AROUND
80 MOST AREAS...TO AROUND 84 IN SOUTHEASTERN PORTIONS OF THE
FORECAST AREA. DEWPOINTS IN THE 60S TO AROUND 70 THIS MORNING
SHOULD DECREASE TO AROUND 60-65 BY AFTERNOON WITH ADVECTION OF
DRIER AIR FROM THE NORTH. NO UPDATES NEEDED THIS MORNING OTHER
THAN MINOR ADJUSTMENTS TO HOURLY TEMP/DEWPOINT/WIND TRENDS.
&&
.SHORT TERM...(TODAY)
ISSUED AT 318 AM CDT TUE JUL 21 2015
FRONTAL BOUNDARY LYING ACROSS SOUTHEAST ILLINOIS THIS MORNING WITH
MOST OF THE DEEP CONVECTION SOUTH OF THIS FEATURE WITH A SECONDARY
BOUNDARY NOTED ON THE LATEST SURFACE ANALYSIS EXTENDING ACROSS THE
ILLINOIS RIVER VALLEY. SOME BROKEN CLOUDS ASSOCIATED WITH THE
SECONDARY BOUNDARY BUT HAVE NOT SEEN ANY PRECIP ASSOCIATED WITH THE
BAND OF CLOUDS. SOME PATCHY FOG HAS DEVELOPED OVER PARTS OF EAST
CENTRAL ILLINOIS OVER THE PAST SEVERAL HOURS AND WILL SEE THAT
GRADUALLY SHIFT INTO SOUTH CENTRAL THROUGH SOUTHEAST ILLINOIS EARLY
THIS MORNING AS DRIER AIR ADVECTS SOUTHEAST INTO THE FORECAST AREA.
OUR WEATHER TODAY WILL FEATURE PLEASANTLY WARM TEMPERATURES AND
LOWER HUMIDITY LEVELS AS HIGH PRESSURE SETTLES IN FROM THE NORTHWEST
THIS AFTERNOON. FORECAST SOUNDINGS OFF THE GFS SUGGEST WE SHOULD MIX
DOWN FROM ABOUT 850 MB THIS AFTERNOON WHICH WOULD GIVE US HIGHS IN
THE 80 TO 84 DEGREE RANGE, WHILE THE RAP SOUNDINGS WERE MUCH MORE
AGGRESSIVE WITH MIXING HEIGHTS YIELDING HIGHS IN THE MID TO EVEN
UPPER 80S IN OUR SOUTHEAST COUNTIES. THINK THE CURRENT RAP MAY BE
UNDERPLAYING THE COOL ADVECTION FILTERING IN FROM THE NORTHWEST SO
WILL SIDE WITH THE MORE CONSERVATIVE GFS SOLUTION AND TEMPERATURES
FOR THIS AFTERNOON.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 318 AM CDT TUE JUL 21 2015
HIGH PRESSURE BUILDING BACK INTO THE REGION FOR THE SHORT TERM
BRINGING A DRIER FORECAST AND A LESS MUGGY AIRMASS. TEMPS JUST
BELOW NORMAL FOR THE NEXT TWO DAYS BEHIND TODAYS COLD FRONT. WIDE
UPPER RIDGE OVER THE SOUTHERN THIRD OF THE CONUS STARTING TO AMPLIFY
A BIT TOWARDS THE END OF THE WEEK. MIDWEST GETTING INTO THE RIDGE
WITH LITTLE FLOW ALOFT AS A QUICK IMPULSE RIPPLES OVER THE RIDGE AND
DIVES INTO THE MID MISS RIVER VALLEY WED NIGHT AND INTO THURSDAY.
FOR NOW, THE FORECAST IS DRY, BUT THE NAM IS SHOWING SIGNS OF A
SLIGHTLY DIFFERENT TRACK JUST TO THE NE AND INTO ILX/S SW. SLIGHTS
WILL REMAIN IN THE FORECAST FOR THU/THU NIGHT.
AS THE UPPER RIDGE BUILDS ACROSS THE MIDDLE OF THE CONUS WITH THE
AXIS DRIFTING OVER THE MIDWEST, A WARMING TREND RETURNS FOR THE END
OF THE WEEK AND INTO THE WEEKEND. POOL OF HEAT OVER THE DESERT SW
SLOWLY ENCROACHING ON THE MIDWEST WITH 850MB TEMPS REACHING 20-23C
BY SATURDAY AFTERNOON AS THE RIDGE AMPLIFIES. MIXED DOWN, TEMPS AT
THE SFC SET TO MAX INTO THE MID TO UPPER 80S, SLIGHTLY ABOVE
CLIMATOLOGY, AS WELL AS SLIGHTLY ABOVE THE MAJORITY OF THE
GUIDANCE...AND HAVE ADJUSTED THE FORECAST IN THAT DIRECTION.
CONCERNED ABOUT THE FORECAST THROUGH THE WEEKEND WITH REGARDS TO THE
PRECIPITATION. UNDER THE EXPANSIVE RIDGE, MODELS ARE NOT HANDLING
SMALL IMPULSES WITH ANY KIND OF CONTINUITY OR CONSENSUS. SLIGHTS
AND LOW CHANCE POPS DOMINATE THE SUPERBLEND AS A RESULT THROUGH THE
WEEKEND AND INTO THE FIRST PART OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 605 AM CDT TUE JUL 21 2015
VFR CONDITIONS ARE EXPECTED ACROSS THE FORECAST AREA THRU THIS
PERIOD. WE SHOULD SEE SOME SCATTERED TO OCCASIONALLY BROKE CUMULUS
DEVELOP BETWEEN 14-16Z WITH BASES IN THE 2800 TO 4000 FOOT RANGE.
AT THIS TIME WILL GO WTIH A SCATTERED BASE LATER THIS MORNING
AROUND 3500 FEET. SURFACE WINDS WILL BE OUT OF THE NORTH AT
10 TO 15 KTS...WITH A NORTHERLY COMPONENT EXPECTED TONIGHT WITH
SPEEDS OF AROUND 5 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ONTON
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS LINCOLN IL
608 AM CDT TUE JUL 21 2015
.SHORT TERM...(TODAY)
ISSUED AT 318 AM CDT TUE JUL 21 2015
FRONTAL BOUNDARY LYING ACROSS SOUTHEAST ILLINOIS THIS MORNING WITH
MOST OF THE DEEP CONVECTION SOUTH OF THIS FEATURE WITH A SECONDARY
BOUNDARY NOTED ON THE LATEST SURFACE ANALYSIS EXTENDING ACROSS THE
ILLINOIS RIVER VALLEY. SOME BROKEN CLOUDS ASSOCIATED WITH THE
SECONDARY BOUNDARY BUT HAVE NOT SEEN ANY PRECIP ASSOCIATED WITH THE
BAND OF CLOUDS. SOME PATCHY FOG HAS DEVELOPED OVER PARTS OF EAST
CENTRAL ILLINOIS OVER THE PAST SEVERAL HOURS AND WILL SEE THAT
GRADUALLY SHIFT INTO SOUTH CENTRAL THROUGH SOUTHEAST ILLINOIS EARLY
THIS MORNING AS DRIER AIR ADVECTS SOUTHEAST INTO THE FORECAST AREA.
OUR WEATHER TODAY WILL FEATURE PLEASANTLY WARM TEMPERATURES AND
LOWER HUMIDITY LEVELS AS HIGH PRESSURE SETTLES IN FROM THE NORTHWEST
THIS AFTERNOON. FORECAST SOUNDINGS OFF THE GFS SUGGEST WE SHOULD MIX
DOWN FROM ABOUT 850 MB THIS AFTERNOON WHICH WOULD GIVE US HIGHS IN
THE 80 TO 84 DEGREE RANGE, WHILE THE RAP SOUNDINGS WERE MUCH MORE
AGGRESSIVE WITH MIXING HEIGHTS YIELDING HIGHS IN THE MID TO EVEN
UPPER 80S IN OUR SOUTHEAST COUNTIES. THINK THE CURRENT RAP MAY BE
UNDERPLAYING THE COOL ADVECTION FILTERING IN FROM THE NORTHWEST SO
WILL SIDE WITH THE MORE CONSERVATIVE GFS SOLUTION AND TEMPERATURES
FOR THIS AFTERNOON.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 318 AM CDT TUE JUL 21 2015
HIGH PRESSURE BUILDING BACK INTO THE REGION FOR THE SHORT TERM
BRINGING A DRIER FORECAST AND A LESS MUGGY AIRMASS. TEMPS JUST
BELOW NORMAL FOR THE NEXT TWO DAYS BEHIND TODAYS COLD FRONT. WIDE
UPPER RIDGE OVER THE SOUTHERN THIRD OF THE CONUS STARTING TO AMPLIFY
A BIT TOWARDS THE END OF THE WEEK. MIDWEST GETTING INTO THE RIDGE
WITH LITTLE FLOW ALOFT AS A QUICK IMPULSE RIPPLES OVER THE RIDGE AND
DIVES INTO THE MID MISS RIVER VALLEY WED NIGHT AND INTO THURSDAY.
FOR NOW, THE FORECAST IS DRY, BUT THE NAM IS SHOWING SIGNS OF A
SLIGHTLY DIFFERENT TRACK JUST TO THE NE AND INTO ILX/S SW. SLIGHTS
WILL REMAIN IN THE FORECAST FOR THU/THU NIGHT.
AS THE UPPER RIDGE BUILDS ACROSS THE MIDDLE OF THE CONUS WITH THE
AXIS DRIFTING OVER THE MIDWEST, A WARMING TREND RETURNS FOR THE END
OF THE WEEK AND INTO THE WEEKEND. POOL OF HEAT OVER THE DESERT SW
SLOWLY ENCROACHING ON THE MIDWEST WITH 850MB TEMPS REACHING 20-23C
BY SATURDAY AFTERNOON AS THE RIDGE AMPLIFIES. MIXED DOWN, TEMPS AT
THE SFC SET TO MAX INTO THE MID TO UPPER 80S, SLIGHTLY ABOVE
CLIMATOLOGY, AS WELL AS SLIGHTLY ABOVE THE MAJORITY OF THE
GUIDANCE...AND HAVE ADJUSTED THE FORECAST IN THAT DIRECTION.
CONCERNED ABOUT THE FORECAST THROUGH THE WEEKEND WITH REGARDS TO THE
PRECIPITATION. UNDER THE EXPANSIVE RIDGE, MODELS ARE NOT HANDLING
SMALL IMPULSES WITH ANY KIND OF CONTINUITY OR CONSENSUS. SLIGHTS
AND LOW CHANCE POPS DOMINATE THE SUPERBLEND AS A RESULT THROUGH THE
WEEKEND AND INTO THE FIRST PART OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 605 AM CDT TUE JUL 21 2015
VFR CONDITIONS ARE EXPECTED ACROSS THE FORECAST AREA THRU THIS
PERIOD. WE SHOULD SEE SOME SCATTERED TO OCCASIONALLY BROKE CUMULUS
DEVELOP BETWEEN 14-16Z WITH BASES IN THE 2800 TO 4000 FOOT RANGE.
AT THIS TIME WILL GO WTIH A SCATTERED BASE LATER THIS MORNING
AROUND 3500 FEET. SURFACE WINDS WILL BE OUT OF THE NORTH AT
10 TO 15 KTS...WITH A NORTHERLY COMPONENT EXPECTED TONIGHT WITH
SPEEDS OF AROUND 5 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
650 AM EDT TUE JUL 21 2015
.SYNOPSIS...
ISSUED AT 648 AM EDT TUE JUL 21 2015
HIGH PRESSURE WILL MOVE INTO THE GREAT LAKES AND OHIO VALLEY
REGION TODAY BRINGING COOLER TEMPERATURES AND LESS HUMID AIR. IT
WILL BE MOSTLY SUNNY TODAY WITH HIGHS IN THE MIDDLE TO UPPER 70S.
WITH MOSTLY CLEAR SKIES AND LIGHT WINDS TONIGHT...LOW TEMPERATURES
WILL FALL INTO THE 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 421 AM EDT TUE JUL 21 2015
SHORT WAVE MOVING ACROSS THE GREAT LAKES THIS MORNING WITH
ASSOCIATED COLD FRONT SLOWLY WORKING SOUTH ACROSS OUR LOCAL AREA.
A FEW ISOLATED SHOWERS HAD POPPED ALONG FRONT ACROSS NORTHERN
COUNTIES EARLY THIS MORNING. HIRES HRRR AND RAP GUIDANCE HAD THIS
HANDLED AND INDICATE AN ISOLATED SHRA REMAINS POSSIBLE THROUGH
DAYBREAK IN THE NORTH AND NORTHEAST NEAR FRONT. A FEW OF THE HRRR
RUNS TRIES TO DEVELOP WEAK SHOWERS ALONG FRONT IN THE SOUTHEAST
LATER THIS MORNING. RECENT RADAR RETURNS HAVE BEGUN TO WEAKEN AND
EXPECT MOST ACTIVITY WILL DIMINISH OR REMAIN VERY ISOLATED. WILL
CARRY AN ISOLATED SHRA THROUGH 12Z DOWNSTREAM FROM CURRENT RADAR
RETURNS BUT MOST AREAS WILL REMAIN DRY.
ONCE COLD FRONT EXITS THE AREA HIGH PRESSURE WILL BUILD IN WITH
SKIES BECOMING MOSTLY SUNNY. COOLER AND LESS HUMID AIR WILL FOLLOW
TODAY. HIGHS IN THE 70S WITH COMFORTABLE HUMIDITY LEVELS. WITH HIGH
OVER THE REGION TONIGHT SKIES WILL BE CLEAR AND WINDS LIGHT. THIS
WILL ALLOW MIN TEMPS TO DROP INTO THE 50S.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 421 AM EDT TUE JUL 21 2015
A TRANQUIL PATTERN WILL PERSIST THROUGH FRIDAY AS AN UPPER LEVEL
RIDGE GRADUALLY BUILDS NORTH OF THE OHIO RIVER. KEPT THE FORECAST
DRY THROUGH FRIDAY NIGHT GIVEN A SEASONALLY DRY
SOUNDING...SOMEWHAT OF A LOW LEVEL CAP...LARGE SCALE SUBSIDENCE
AND STABLE MID LEVEL LAPSE...GENERALLY 4.0 TO 6.5 C/KM. KEPT THE
GENERAL ONGOING TIMING FOR STORMS THIS WEEKEND AS SOME SHORT WAVE
ENERGY FROM AN UPPER LEVEL TROF WILL BE ABLE TO TOP THE RIDGE AND
DESCEND INTO THE WESTERN/UPPER GREAT LAKES REGION. BOTH THE GFS
AND THE ECMWF ARE IN AGREEMENT WITH THE TIMING OF THIS SYSTEM.
THESE MODELS ALSO EXPAND THE UPPER LEVEL RIDGE FARTHER NORTHEAST
WITH 500 HEIGHTS BUILDING ABOVE 590 DEKAMETERS NEAR THE END OF THE
PERIOD. OTHERWISE...HIGHS SHOULD BE FROM AROUND 80 TO THE MID 80S
WITH LOWS AROUND 60 RISING INTO THE MID 60S AS THE UPPER LEVEL
RIDGE BUILDS NORTHEAST EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 648 AM EDT TUE JUL 21 2015
VFR CONDITIONS EXPECTED. ISOLATED SHOWERS HAVE DISSIPATED AND
FRONT HAS CLEARED TAF SITES. WINDS WILL VEER TO ABOUT 340-360
DEGREES THIS MORNING AROUND 10 KNOTS THEN BACK TO 290-320 DEGREES
THIS AFTERNOON. WINDS BECOME LIGHT AND VARIABLE THIS EVENING.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
933 AM EDT TUE JUL 21 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH THIS AFTERNOON AND CROSS THE AREA THIS
EVENING. AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL REMAIN OVER
THE REGION THROUGH THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
920 AM UPDATE...SLOWED THE TIMING OF OF THE ORGANIZED SHOWERS AND
STORMS BY 3 HRS USING THE HRRR 3KM MODEL TO INITIALIZE. VISIBLE
SATELLITE IMAGERY SHOWED CLEARING BACK ACROSS WESTERN AREAS WHILE
EASTERN AREAS WERE CLOUDED OVER KEEPING THINGS STABLE. PRE-FRONTAL
TROF AHEAD THE COLD FRONT WILL KICK OFF SOME SCATTERED SHOWERS AND
PERHAPS A FEW TSTMS BASED ON THE BEST INSTABILITY DUE TO
AVAILABLE HEATING. LAPS DATA SHOWED THE FAR WESTERN AREAS ALREADY
DESTABILIZING W/LIS DOWN TO -2. KEPT SOME FOG ACROSS THE DOWNEAST
COAST THROUGH LATE MORNING.
AS THE COLD FRONT SLIDES EAST THIS AFTN, EXPECT SHOWERS TO
INCREASE IN COVERAGE WITH CONVECTION DVLPNG AS AIRMASS
DESTABILIZES. MODELS INDICATING A PRE-FRONTAL TROF WL DVLP THIS
AFTN ACRS THE ALLAGASH AND SLIDE THRU NRN MAINE LATE THIS AFTN AND
EVNG.
AIRMASS PROGGED TO DESTABILIZE AS TEMPS WARM INTO THE 70S WITH TDS
IN THE 60S. H7-H5 LR EXPECTED TO BE BTWN 6.0-6.5 C/KM AFT 18Z MAINLY
ACRS FAR NW ZONES. GIVEN EXTENSIVE LOW CLDS THRU THE MRNG, HTG WL BE
LIMITED WITH MLCAPES CAPPED RIGHT AROUND 600 J/KG. 0-6KM BULK SHEAR
VALUES DRG THE AFTN PROGGED TO BE ARND 25KTS WITH VALUES NOT
INCREASING UNTIL AFT FROPA OCCURS. TIMING LOOKS TO BE OFF FOR ANY
SVR THREAT WHICH GOES ALONG WITH SPC`S DAY1 OUTLOOK. WL TONE DOWN
WORDING IN HWO FOR TDA AND JUST MENTION STRONG STORMS WITH
POTENTIALLY HVY RAINFALL.
FOR TONIGHT, FRONT MVS THRU CWA BY 12Z WED. EXPECT LINE OF STORMS TO
GRADUALLY DIMINISH THRU MIDNIGHT WITH JUST LEFT-OVR SHOWERS BHND.
FRONT WL TAKE AWHILE TO CLR WATERS LEAVING AREA OF FOG IN PRETTY
MUCH ALL NIGHT ONCE IT SETS BACK IN AFT 04Z, WHICH HAS BEEN THE CASE
THE LAST FEW NIGHTS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
A COLD FRONT WILL BE MOVING AWAY TO THE EAST ON WEDNESDAY AS A
CORRIDOR OR DRY AIR MOVES ACROSS THE AREA BRINGING PARTIAL SUNSHINE.
THE SUNSHINE MAY PROVIDE ENOUGH INSTABILITY FOR A STRAY SHOWER OR
THUNDERSHOWER, MAINLY ACROSS THE NORTH, WEDNESDAY AFTERNOON. A COOL
TROUGH OF LOW PRESSURE OVER QUEBEC WILL THEN BEGIN TO DROP INTO THE
AREA LATE WEDNESDAY NIGHT INTO THURSDAY. THIS WILL BRING MOSTLY
CLOUDY AND COOLER CONDITIONS WITH A GOOD CHANCE FOR SHOWERS ACROSS
THE NORTH, MAINLY THURSDAY. HIGHS THURSDAY WILL AVERAGE ABOUT TEN
DEGREES BELOW NORMAL ACROSS THE AREA AS THE COMBINATION OF SURFACE
LOW PRESSURE TO THE EAST AND UPPER LEVEL LOW PRESSURE ALOFT PULLS
COOL AIR DOWN FROM CANADA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL MAINTAIN COOL AND CLOUDY
CONDITIONS FRIDAY INTO EARLY SATURDAY. SKIES MAY BRIGHTEN LATER
SATURDAY AS THE TROUGH SLIDES OFF TO THE EAST AND A RIDGE OF HIGH
PRESSURE BEGINS BUILDING INTO THE REGION. THIS MAY BRING A MOSTLY
CLEAR NIGHT SATURDAY NIGHT WITH PATCHY FOG LATE. A FAST MOVING
TROUGH OF LOW PRESSURE WILL THEN APPROACH ON SUNDAY BRINGING CLOUDY
CONDITIONS AGAIN WITH A CHANCE FOR SCATTERED AFTERNOON SHOWERS AND
THUNDERSTORMS. GENERALLY COOL CONDITIONS WILL LIKELY PERSIST INTO
EARLY NEXT WEEK AS AN AMPLIFIED PATTERN MAINTAINS A TROUGH OVER THE
NORTHEAST.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: LOW MVFR/IFR EXPECTED THROUGH THE DAY. COLD FRONT WILL
RACE THROUGH DURING THE AFTERNOON AND EVENING, POSSIBLY BRINGING
STORMS WITH GUSTY/VRB WINDS. SHOWERS EXPECTED BEHIND FRONTAL BNDRY
WITH IFR CIGS SETTING IN THROUGH END OF TAF VALID TIME.
SHORT TERM: CONDITIONS WILL LIKELY BECOME VFR WEDNESDAY THEN MAY
DROP TO MVFR WEDNESDAY NIGHT ACROSS THE NORTH. MVFR CONDITIONS
ACROSS THE NORTH AND VFR CONDITIONS DOWNEAST ARE LIKELY THURSDAY
INTO THURSDAY NIGHT THEN MVFR CONDITIONS ARE LIKELY THROUGHOUT THE
AREA ON FRIDAY. CONDITIONS SHOULD IMPROVE TO VFR ON SATURDAY.
&&
.MARINE...
NEAR TERM: AREAS OF FOG WILL AFFECT THE WATERS THROUGH WED MORNING
BEFORE A COLD FRONT PASSES. SEAS AND WINDS WILL REMAIN BELOW SMALL
CRAFT CRITERIA THROUGH WED.
SHORT TERM: WINDS AND SEAS ARE EXPECTED TO REMAIN BELOW SCA
ACROSS THE AREA THIS WEEK.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
721 AM EDT TUE JUL 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM EDT TUE JUL 21 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT
OVER THE UPR LKS BTWN CLOSED LO NEAR JAMES BAY AND UPR RDG OVER THE
ROCKIES/WRN PLAINS. A DISTURBANCE DROPPING SEWD THRU NW ONTARIO
IN CONCERT WITH SOME MSTR IN THE H85-7 LYR SHOWN ON THE 00Z INL/YPL
RAOBS IS BRINGING SCT-BKN AC THRU MUCH OF NW ONTARIO...NRN MN AND
LK SUP. FARTHER TO THE W IN MANITOBA CLOSER TO THE UPR RDG AXIS
AND UNDER STRONGER DEEP LYR QVECTOR DVGC...THE 00Z THE PAS RAOB AT
THE NRN END OF LK WINNIPEG SHOWS A MUCH SHARPER MID LVL INVRN. SKIES
IN THIS AREA ARE MOCLR. DESPITE SOME RELATIVELY DRY LLVL AIR AND
LLVL CAA...STEADY NW WINDS UNDER SHARPER PRES GRADIENT WELL E OF HI
PRES CENTER IN THE NRN PLAINS HAS LIMITED THE DIURNAL TEMP DROP.
RELATIVELY QUIET QUIET WX WL DOMINATE THE SHORT TERM. MAIN FCST
CONCERNS FOCUS ON CLD TRENDS TODAY AND TEMPS TODAY/TNGT.
TODAY...SHRTWV DIGGING SEWD THRU NW ONTARIO IS FCST TO BE OVER NE LK
SUP BY 12Z AND THEN OVER SE ONTARIO BY 00Z THIS EVNG...WITH DNVA/
SHARPER DEEP LYR QVECTOR OVER THE UPR LKS IN ITS WAKE BRINGING 12HR
H5 HGT RISES UP TO 50M IN ITS WAKE. EXPECT SCT-BKN CU TO DEVELOP BY
LATE MRNG WITH DAYTIME HEATING UNDER H85 THERMAL TROF/LINGERING
MSTR...BUT TENDENCY DURING THE AFTN SHOULD BE FOR THE CU TO SCT OUT
WITH SHARPENING SUBSIDENCE INVRN/ARRIVAL OF DRIER AIR SHOWN ON THE
PAS RAOB. SOME OF THE HI RES MODELS EVEN GENERATE SOME ISOLD
SHOWERS OVER THE ECNTRL CWA TOWARD NOON...BUT WL MAINTAIN DRY FCST
FOR NOW GIVEN RELATIVELY STABLE MID LYRS SHOWN ON THE UPSTREAM
RAOBS/FCST SDNGS. WINDS MAY ALSO GET A BIT GUSTY AGAIN THIS MRNG
UNDER SHARPER PRES GRADIENT/STEEPENING LLVL LAPSE RATES...BUT SFC HI
PRES MOVING OVER THE CWA IN THE AFTN SHOULD RESULT IN DIMINISHING
WINDS. THE MORE PERSISTENT GUSTY WINDS WL BE OVER THE E...WHERE THE
TIGHTER GRADIENT WL LINGER LONGER AND LK BREEZE COMPONENT OFF LK SUP
WL ACCENTUATE THIS FLOW. EXPECT THE LOWEST MAX TEMPS IN THIS AREA AS
WELL WITH MORE LK SUP MODERATION. LOCATIONS NEAR THE SHORE E OF MQT
WL SEE HI TEMPS HOLDING IN THE 60S. AS H85 TEMPS REBOUND TO NEAR 12Z
ALONG THE WI BORDER LATER IN THE DAY...THE MERCURY SHOULD RISE WELL
INTO THE 70S AND AT LEAST APRCH 80 AT A FEW LOCATIONS OVER THE
SCENTRAL WITH DOWNSLOPE FLOW AND LIMITED LK BREEZE OFF LK MI.
TNGT...EXPECT LINGERING CU TO DSPT EARLY AND GIVE WAY TO MOCLR
SKIES UNDER LARGER SCALE SUBSIDENCE/LOSS OF DAYTIME HEATING. LO
TEMPS WL BE COOLEST OVER THE W CLOSER TO SFC HI PRES RDG AXIS APRCHG
WRN LK SUP/WEAKER PRES GRADIENT. THE COOL SPOTS MAY SEE THE
THERMOMETER READ AS LO AS 45 BY DAYBREAK.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM EDT TUE JUL 21 2015
IMPACTS...NO SIGNIFICANT IMPACTS ARE WITHIN PREDICTABLE RANGE.
POSSIBILITY FOR STRONG TO SEVERE STORMS OVER PARTS OF THE REGION
LATE FRI INTO SAT...BUT STILL VERY UNCERTAIN ON THAT ASPECT.
MAY SEE SHOWERS AND THUNDERSTORMS ALONG AND/OR NEAR THE WI BORDER
THU AS MODELS SHOW A WARM FRONT MOVING INTO THE AREA FROM THE
W...WHICH MAINLY INCREASES MID LEVEL MOISTURE ENOUGH TO ALLOW FOR
WEAK CONVECTIVE POTENTIAL. MODELS ARE SLOWER WITH THE FRONT THAN
THEY WERE YESTERDAY...SO WILL CONTINUE TREND OF LOWERING DEW POINTS
ON WED AFTERNOON...BUT FIRE WEATHER CONCERNS WILL BE MINIMAL GIVEN
LIGHT WINDS. WILL KEEP SLIGHT CHANCE POPS INTO AREAS ALONG THE WI
BORDER THU.
THE DISTURBANCE THAT THE WARM FRONT IS TIED TO WILL MOVE ACROSS
MANITOBA CANADA AND HUDSON BAY FRI INTO SUN...DRAGGING A SFC
TROUGH/COLD FRONT THROUGH THE AREA. DEFINITELY SOME DIFFERENCES
BETWEEN MODELS WITH THIS SYSTEM...WITH THE 00Z/21 GFS BEING STRONGER
AND FARTHER S THAN THE 12Z/20 ECMWF. WILL USE CONSENSUS GUIDANCE
GIVEN THE UNKNOWNS INVOLVED...WHICH WILL SHOW SHOWERS AND
THUNDERSTORMS MOVING W TO E ACROSS THE CWA FROM LATE FRI THROUGH
SAT. SUN LOOKS DRY FOR NOW. DEPENDING ON TIMING AND OTHER
FACTORS...COULD SEE INGREDIENTS COME TOGETHER FOR SOME STRONG TO
SEVERE STORMS MAINLY S OF THE CWA.
SUN LOOKS DRY AND MON MAY SEE SOME RAIN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 720 AM EDT TUE JUL 21 2015
ALTHOUGH SOME DIURNAL CU/SC WL DVLP TODAY WITH DAYTIME HEATING IN
COOL NW FLOW E OF HI PRES APRCHG FM THE NRN PLAINS...RELATIVELY DRY
LLVL AIR INDICATES CIGS WL BE VFR. GUSTY WINDS WL ALSO DEVELOP WITH
THE DAYTIME HEATING/MIXING. AS THE HI PRES EDGES CLOSER LATER
TDAY/THIS EVNG...SKIES WL TURN MOCLR AND WINDS WL DIMINISH.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 AM EDT TUE JUL 21 2015
STEADY WNW WINDS UP TO ABOUT 20 KTS WILL DIMINISH TONIGHT WITH THE
CLOSER APPROACH OF HI PRES FROM THE NORTHERN PLAINS. SINCE THE HI
PRES WILL LINGER NEAR THE GREAT LAKES MUCH OF THIS WEEK...WINDS
SHOULD BE UNDER 20 KTS MOST OF THE TIME. SOME STRONGER WINDS UP TO
20 KTS WILL BE POSSIBLE ON FRI/SAT AS A COLD FRONT CROSSES THE
REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
605 AM CDT TUE JUL 21 2015
.UPDATE...
UPDATED TO INCLUDE THE 12Z AVIATION DISCUSSION BELOW.
JCL
&&
.DISCUSSION... /ISSUED 308 AM CDT TUE JUL 21 2015/
CURRENTLY A SNAKING LINE OF CONVECTION EXTENDING FROM THE TEXAS
PANHANDLE TO EASTERN KENTUCKY CONTINUES TO FIZZLE MIDWAY ACROSS
THE MIDSOUTH THIS MORNING...LEAVING ONLY A FEW SHOWERS IN EASTERN
ARKANSAS AND A BLANKET OF MID AND HIGH LEVEL MOISTURE. CLOUD COVER
WAS KEEPING TEMPERATURES A DEGREE OR TWO WARMER THAN THIS TIME
LAST NIGHT FROM I-40 SOUTH...WHILE EVENING RAIN EARLIER AND A WEAK
OUTFLOW BOUNDARY IS PROVIDING COOLER TEMPERATURES FARTHER NORTH.
THE HRRR SHOWS NEW CONVECTION FORMING ACROSS THE NORTH BY 4
AM...BUT RADAR TRENDS AND MESOANALYSIS IS SUGGESTING MORE
STABILITY IN THIS REGION.
FOR TODAY THROUGH THURSDAY...THE MIDSOUTH WILL TAKE A SHORT BREAK
FROM THE HEAT THIS PERIOD...WITH THE ONLY EXCEPTION BEING THE
SOUTHERN TWO TIER OF COUNTIES TODAY....WHERE A HEAT ADVISORY IS
IN EFFECT STARTING LATER THIS MORNING. THE UPPER RIDGE IS EXPECTED
TO SAG FAR ENOUGH SOUTH TO ALLOW THE PREVAILING WESTERLIES...AND
ASSOCIATED DISTURBANCES TO PASS OVER A STALLED SURFACE FRONT.
EACH FEATURE ALLOWING THE CHANCE FOR SHOWERS AND STORMS TO
FORM...WITH A NEAR EQUAL THREAT BOTH DAY AND NIGHT. TOMORROW
APPEARS THE COOLEST BY THE MODELS WITH PLENTY OF HIGHS IN THE 80S
AND WIDESPREAD HEAT INDICES FINALLY DIPPING BELOW 100F. THE
BIGGER QUESTION IS WILL THERE BE A THREAT FOR SEVERE WEATHER OR
FLASH FLOODING. MU CAPE VALUES BY THE MID AFTERNOON HOURS WILL
RANGE FROM 2000 TO 3500 J/KG AND THE POSSIBILITY OF STORMS
TRAINING SEEMS VERY PLAUSIBLE. FEEL PULSE TYPE STORMS WILL
DEVELOP TODAY AND TOMORROW WITH THE GREATER POTENTIAL FOR
SOMETHING MORE ORGANIZED HAPPENING TOMORROW NIGHT AND THURSDAY
WHEN A 25KT LLJ AT 850MB INTERSECTS THE REGION. WILL KEEP THE
SAME MENTION IN THIS MORNINGS HWO WITH THE ADDITION OF A LOCALIZED
FLASH FLOODING THREAT.
FRIDAY THROUGH MONDAY...THE GFS AND EURO ARE IN GOOD AGREEMENT
THAT THE RIDGE WILL BUILD BACK NORTH...BUT THERE ARE SLIGHT
DIFFERENCES ON JUST HOW FAR EAST. THE FARTHER WEST EURO SOLUTION
WOULD KEEP THE MIDSOUTH IN THE CROSSHAIRS FOR MORE MCS
CONVECTION/NORTHWESTERLY FLOW...WHILE THE GFS IS A BIT HOTTER AND
DRIER AS THE RIDGE MOVES INTO THE TENNESSEE RIVER VALLEY. THIS
WOULD LEAD TO PERHAPS ISOLATED DIURNAL CONVECTION AT BEST. FOR
NOW HAVE LEANED MORE TOWARDS THE GFS...AS IT IS HANDLING THE
CURRENT SITUATION BETTER. HIGHS WOULD CLIMB BACK INTO THE MID AND
UPPER 90S...AND THE NEED FOR ADDITIONAL HEAT PRODUCTS LIKELY.
JAB
&&
.AVIATION...
12Z TAF CYCLE (21/12Z-22/12Z)
VFR CONDITIONS WILL PREVAIL DURING THE PERIOD. HOWEVER...CONDITIONS
OCCASIONALLY LOWERING IN SCATTERED SHOWERS AND THUNDERSTORMS
DEVELOPING MAINLY LATE THIS MORNING AND AFTERNOON...CONTINUING
INTO TONIGHT. UNTIL CAN PINPOINT BETTER...WENT VCTS / VCSH AT THE
TAF SITES. WINDS TODAY W-NW 5-8 KTS TURNING TO THE NE AT KJBR BY
AFTERNOON. WINDS TONIGHT LIGHT.
JCL
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR PHILLIPS.
MO...NONE.
MS...HEAT ADVISORY FROM 11 AM THIS MORNING TO 7 PM CDT THIS EVENING
FOR CALHOUN-CHICKASAW-COAHOMA-ITAWAMBA-LAFAYETTE-LEE MS-
MONROE-PANOLA-PONTOTOC-QUITMAN-TALLAHATCHIE-UNION-YALOBUSHA.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
644 AM CDT TUE JUL 21 2015
.AVIATION...
VFR CONDITIONS IN PLACE AT ALL TERMINALS. THERE IS A POSSIBILITY
OF ANOTHER ROUND OF STORMS IMPACTING KLBB AND KPVW THIS AFTERNOON
AND A PROB30 HAS BEEN INTRODUCED TO TAKE THIS INTO ACCOUNT. KCDS
SHOULD BE FAR ENOUGH EAST THAT THE THREAT OF STORMS IS FAIRLY
SMALL. CONFIDENCE IN TIMING IS NOT VERY HIGH SO EXPECT TO SEE
ADJUSTMENTS IN TIMING FOR STORMS THROUGH THE DAY. VFR CONDITIONS
EXPECTED OVERNIGHT TONIGHT INTO WEDNESDAY MORNING AS WELL.
JORDAN
&&
.PREV DISCUSSION... /ISSUED 400 AM CDT TUE JUL 21 2015/
SHORT TERM...
AS WAS EXPECTED...A FAIRLY LARGE MCS DEVELOPED ALONG AND BEHIND A
WEAK COLD FRONT RESULTING IN CONSIDERABLE AMOUNTS OF PRECIPITATION
ACROSS SOME AREAS IN THE NORTHERN PART OF OUR FORECAST AREA. THE
MCS DEVELOPED A STRONG OUTFLOW BOUNDARY WHICH SURGED THROUGH THE
LUBBOCK AREA BEFORE MIDNIGHT AND WAS LOCATED ALONG A SEMINOLE...
POST...TO KNOX CITY LINE AT 3 AM. THIS LEAVES ONLY STONEWALL COUNTY
TO THE SOUTHEAST OF THE OUTFLOW BOUNDARY. ALOFT...THE 00Z UPPER-AIR
ANALYSIS SHOWS THE CENTER OF THE HIGH PRESSURE RIDGE HAS SHIFTED A
BIT FURTHER SOUTH OVER SOUTH CENTRAL TEXAS WITH A GOOD MONSOON
MOISTURE PLUME LOCATED ACROSS NEW MEXICO CURVING BACK OVER THE TEXAS
PANHANDLE. IT WAS TOUGH TO PICK OUT ANY FORM OF SHORTWAVE ACTIVITY
IN THE UPPER-AIR ANALYSIS AND THE MCS HAS PUMPED CONSIDERABLE
MOISTURE INTO THE ATMOSPHERE AS SHOWN IN THE WATER VAPOR LOOP...ALSO
MASKING ANY SHORTWAVES THAT MAY BE SEEN OVER THE TEXAS PANHANDLE.
IT DOES HOWEVER SHOW A WEAK SWIRL OVER WESTERN NEW MEXICO THAT WILL
BE MOVING TOWARDS THE TEXAS PANHANDLE THROUGH THE DAY WHICH MAY COME
INTO PLAY LATER ON.
MODELS DID A POOR JOB INITIALIZING WITH THE CONVECTION AT 00Z WHICH
COMPLICATES THE FORECAST. THE ONLY MODEL THAT SEEMINGLY HAS A
DECENT START IS THE TTU-WRF AND LEANED HEAVILY TOWARDS THIS MODEL
FOR THE FORECAST THIS MORNING. THE MCS HAS ALREADY PUSHED EAST OUT
OF THE TEXAS PANHANDLE WITH OTHER LIGHTER SHOWER AND ISOLATED
THUNDERSTORMS DEVELOPING ACROSS THE WESTERN SOUTH PLAINS GENERALLY
ALONG AND WEST OF A TULIA TO BROWNFIELD LINE. TTU-WRF AND TO SOME
EXTENT THE NAM...HRRR...AND GFS DECREASE COVERAGE OF ACTIVITY
THROUGH THIS MORNING WITH A LULL IN PRECIPITATION BY MID-DAY.
EVENTUALLY...THE TTU-WRF REDEVELOPS SCATTERED CONVECTION ACROSS THE
WESTERN SOUTH PLAINS BY 21Z AND PUSHES THIS TO THE EAST TOWARDS THE
CAPROCK. THIS SOLUTION SEEMS REASONABLE AS CLOUD COVER WILL TAKE A
BIT TO DISSIPATE THROUGH THE MORNING AND THEN ALLOW SOME SURFACE-
BASED INSTABILITY TO DEVELOP BY THE AFTERNOON. THE WEAK WAVE SEEN
IN THE WATER VAPOR LOOP MAY MOVE CLOSE ENOUGH TO PROVIDE SOME WEAK
LIFT BUT ALL TOGETHER CONDITIONS REMAIN MARGINAL FOR WIDESPREAD
STORMS. FORECAST SOUNDINGS ACROSS THE AREA SHOW QUITE THE RANGE OF
SBCAPE VALUES RANGING FROM SUB 500 J/KG IN THE NAM AND TTU-WRF TO
ALMOST 2500 J/KG IN THE HRRR AND RAP. IF STORMS DO DEVELOP...COULD
ONCE AGAIN SEE A MARGINAL SEVERE WEATHER THREAT MAINLY IN THE FORM
OF DOWNBURSTS.
ALL THIS PUT TOGETHER MEANS THAT HIGH TEMPERATURES WERE UNDERCUT
ACROSS THE NORTHERN SOUTH PLAINS WHERE THE HEAVIEST RAINFALL FELL
LAST NIGHT/EARLY THIS MORNING AS SURFACE MOISTURE AND REMNANT CLOUD
COVER SHOULD HELP TO MODERATE TEMPERATURES SOME. THE REST OF THE
AREA SHOULD SEE TEMPERATURES A FEW DEGREES COOLER THAN YESTERDAY BUT
STILL IN THE MID TO UPPER 90S. CHANCE FOR PRECIP WILL INITIALLY BE
HIGHEST THIS MORNING...A LULL IN THE LATE MORNING EARLY AFTERNOON...
THEN PICKING UP AGAIN LATE THIS AFTERNOON FOR THE SOUTH PLAINS. THE
ROLLING PLAINS LOOKS TO BE TOO FAR TO THE EAST TO SEE MUCH IN THE
WAY OF PRECIP AS THE FRONT/OUTFLOW BOUNDARY IS HARD TO FIND AND ALL
MODELS KEEP THE EASTERN ONE THIRD OF THE FORECAST AREA DRY. ONLY
UNCERTAINTY IS HOW LONG POPS WILL GO PAST MIDNIGHT AS THE TTU-WRF
TRIES TO DEVELOP ANOTHER WEAK MESOSCALE CONVECTIVE COMPLEX AROUND
SUNSET BUT THEN DISSIPATES IT BY MIDNIGHT LOCAL TIME BEFORE IT MAKES
IT TO THE EDGE OF THE CAPROCK. A DECENT LOW-LEVEL JET IS FORECAST
TO DEVELOP OVERNIGHT WHICH MAY HELP TO KEEP CONVECTION GOING BUT IT
WILL VEER BETWEEN 06 AND 12Z FROM SOUTH TO SOUTHWEST...NOT GOOD FOR
MAINTENANCE OF ANY CONVECTION THAT DEVELOPS.
JORDAN
LONG TERM...
SEMI-ACTIVE PATTERN AT PRESENT LOOKS TO PERSIST AT LEAST ONE MORE
DAY BEFORE A SUBTROPICAL HIGH RE-EXERTS ITSELF SQUARELY ATOP THE
ROLLING PLAINS FROM THURSDAY AND LASTING THROUGH EARLY NEXT WEEK.
UNTIL THAT MONOTONOUS PATTERN IS REALIZED...A RESIDUAL LAYER OF
MOISTURE AND SLIGHTLY COOLER TEMPS ALOFT WILL PERSIST PARTICULARLY
ACROSS EASTERN NM AND OUR WESTERN ZONES ON WEDNESDAY. BROAD
SURFACE TROUGHING JUST WEST OF THE STATE LINE ALONG WITH WEAK
UPSLOPE FLOW SHOULD HELP TRIGGER SOME AFTN/EVNG STORMS...BUT POPS
ELSEWHERE ON WEDNESDAY WERE TRIMMED BELOW MENTION AS HEIGHT FIELDS
ARE PROGGED TO RISE ABOUT 20 METERS THROUGHOUT THE DAY WHICH
IMPLIES TOO MUCH SUBSIDENCE FOR PRECIP IN THIS OTHERWISE WEAKLY
FORCED PATTERN.
BY THURSDAY...LARGE SCALE SUBSIDENCE WILL TAKE GRASP AREA WIDE
WITH ONLY A FEW MORSELS OF PRECIP POSSIBLE ALONG THE WESTERN
PERIPHERY OF THE HIGH - BUT EVEN THESE ARE NOW SHAPING UP MORE
CONDITIONAL THAN EARLIER MODELS INDICATED SO WE HAVE REMOVED
MEASURABLE PRECIP MENTION ON THURSDAY ACROSS OUR WESTERN COUNTIES.
THEREAFTER...JUST MINOR DAILY OSCILLATIONS OF THE HIGH/S CENTER
ARE THE ONLY CHANGES EXPECTED WITH NEGLIGIBLE IMPACTS ON HIGH
TEMPS. CONSIDERING MODELS KEEP 500 MB MAX HEIGHTS AOB 596 DAM...
HIGHS SHOULD NOT PUSH TOO FAR ABOVE CLIMO DESPITE THE OBVIOUS
WARM BIAS STILL PLAGUING MOS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 85 64 91 66 / 40 30 20 20
TULIA 86 66 92 69 / 40 30 10 10
PLAINVIEW 89 68 91 70 / 40 30 10 10
LEVELLAND 92 68 93 71 / 40 30 20 20
LUBBOCK 92 72 94 72 / 30 30 20 10
DENVER CITY 93 69 94 70 / 40 30 20 20
BROWNFIELD 93 69 94 71 / 30 30 20 20
CHILDRESS 96 72 98 73 / 30 30 10 10
SPUR 94 70 94 73 / 10 20 10 10
ASPERMONT 98 72 98 75 / 10 10 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
14/93/14
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
642 AM CDT Tue Jul 21 2015
.AVIATION...
/12Z TAFS/
The low clouds over the Hill Country dissipated this morning
before reaching KJCT. This will spell VFR conditions across the
forecast area through the TAF period. Expect south winds around 10
kts this afternoon with a high based cu field (8,000-10,000 ft)
developing by midday. A few of the hi-res models continue to
indicate isolated convection this afternoon, mainly west of a
KSWW-KSJT line. However, any cells that develop should remain to
the north and west of the forecast terminals.
Johnson
&&
.PREV DISCUSSION... /ISSUED 411 AM CDT Tue Jul 21 2015/
SHORT TERM...
(Today and tonight)
One shortwave trough is lifting northeast across NM this morning,
providing large scale forcing for ascent across the Panhandle
and portions of west TX. At the surface, a cold front was located
from the south plains, extending northeast into central OK.
Outflow from evening convection is forcing the effective front to
the southeast, from near Vernon, to Jayton, to Midland as of 3 AM.
This boundary will likely move into the Big Country and western
Concho Valley this morning but is expected to erode by midday,
given the shallow nature of the "cool" airmass. This should have
only a slight effect on temperatures this afternoon, mainly over
the northwest quadrant of the CWA. Expect highs ranging from the
upper 90s to near 102 degrees this afternoon, with similar heat
indices.
A second shortwave trough is progged to lift northeast across NM
this afternoon and evening, providing another round of convection
to our north and west. The HRRR and ARW both indicate isolated
convection along the western periphery of the CWA this afternoon,
but the NAM, GFS, and ECMWF are largely dry. While a rogue
shower/storm can`t be ruled out this afternoon, coverage should be
significantly limited given the warm temps aloft, weak cap, and
depth of the boundary layer (increasing dry air entrainment into
potential updrafts). Thus, no PoPs will be carried in the
forecast. Expect partly cloudy conditions overnight with overnight
lows in the mid 70s.
Johnson
LONG TERM...
(Wednesday through next Monday)
By Wednesday, the frontal zone currently currently extending from
the TX panhandle into Oklahoma will be lifting northward into the
central plains. On Thursday, the upper level ridge will re-center
and strengthen directly over west Texas. With the ridge in place
across the southern plains through early next week, persistent
southwesterly flow across the Rocky Mountains will result in lee
troughing, and continue warm, southerly flow for our area through
the extended period. Due to this ridging and persistent southerly
flow, 850mb temperatures will warm a degree or two Celsius by
Monday. This will result in persistent hot and dry weather for our
area with highs in the upper 90s to around 100 degrees, lows in
the mid to upper 70s, and no chance for rainfall.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 98 76 98 76 98 / 5 5 0 0 0
San Angelo 102 75 100 76 99 / 0 0 0 0 0
Junction 100 74 98 74 97 / 0 0 0 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
25
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
639 AM CDT TUE JUL 21 2015
.AVIATION...
/12Z TAFS/
CONCERNS...NONE. VFR WILL PREVAIL.
VFR CONDITIONS WILL PREVAIL WITH GENERALLY SOUTH WINDS AOB 12
KTS. THERE WILL BE SOME VARIANCE IN THE WIND DIRECTION BETWEEN
SOUTH-SOUTHWEST TO SOUTH-SOUTHEAST...BUT FOR MOST OF THE PERIOD
THE WINDS WILL PREVAIL FROM THE SOUTH. HIGH CLOUDS THIS MORNING
FROM RAIN IN OKLAHOMA WILL RESULT IN SCT-BKN SKIES THIS MORNING.
AN ISOLATED SHOWER MAY DEVELOP ALONG AN OUTFLOW BOUNDARY MOVING
ACROSS NORTHWEST TEXAS TOWARDS DFW BUT THE UPPER LEVEL RIDGE WILL
LIKELY SUPPRESS ANY CONVECTION ALONG THIS BOUNDARY.
JLDUNN
&&
.PREV DISCUSSION... /ISSUED 328 AM CDT TUE JUL 21 2015/
THE UPPER LEVEL RIDGE THAT HAS DOMINATED THE WEATHER ACROSS THE
REGION FOR THE LAST WEEK IS SHOWING SOME SIGNS OF A SLIGHT
WEAKENING AS A SHORT WAVE MOVES ACROSS ITS NORTHERN PERIPHERY.
THIS HAS ALLOWED A COLD FRONT TO MOVE DOWN INTO NORTHERN OKLAHOMA
AND WEST TEXAS. THIS FRONT WILL STALL OUT ACROSS CENTRAL OKLAHOMA
INTO WEST TEXAS THIS AFTERNOON OR EVENING BEFORE LIFTING BACK TO
THE NORTH BY WEDNESDAY MORNING.
SOME OF THE HIGH CLOUDS ASSOCIATED WITH CONVECTION ACROSS
OKLAHOMA AND THE TEXAS PANHANDLE WILL ATTEMPT TO MOVE INTO NORTH
TODAY BUT THESE CLOUDS SHOULD THIN. THE MAIN AREA OF DENSER CLOUDS
WILL MOVE EAST ACROSS OKLAHOMA. TEMPERATURES TODAY SHOULD BE A
DEGREE OR TWO COOLER VERSUS YESTERDAY THANKS TO THE WEAKENING
RIDGE. EXPECT HIGHS IN THE MID 90S TO NEAR 100 DEGREES ACROSS THE
REGION. THE HRRR INDICATES THAT SOME ISOLATED
SHOWERS/THUNDERSTORMS WILL TRY TO FORM THIS AFTERNOON FROM
GRANBURY THROUGH THE METROPLEX NORTHEAST TOWARD PARIS. THE
SUBSIDENCE ASSOCIATED WITH THE RIDGE WILL PROBABLY BE TOO STRONG
FOR THIS TO OCCUR SO HAVE JUST PLACED 10 PERCENT POPS WITH NO
WEATHER MENTIONED FOR THIS AFTERNOON AND EVENING ALONG AND NORTH
OF A COMANCHE TO EMORY LINE.
THE UPPER RIDGE WILL SHIFT WEST INTO WEST TEXAS AND RE-STRENGTHEN
LATE WEEK. THIS WILL ALLOW TEMPERATURES TO INCREASE BY A FEW
DEGREES LATE WEEK THROUGH THE WEEKEND. WE MAY BE REACH HEAT
ADVISORY CRITERIA ACROSS THE EASTERN THIRD TO HALF SUNDAY/MONDAY.
THE ECMWF AND GFS INDICATE THAT THE RIDGE WILL SHIFT A LITTLE TO
THE NORTH EARLY TO MID NEXT WEEK...WHICH MAY ALLOW FOR SOME LOW
RAIN CHANCES ACROSS THE SOUTHEASTERN AND SOUTHERN ZONES BY THE
MIDDLE OF NEXT WEEK.
58
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 98 79 98 79 99 / 10 5 5 0 0
WACO, TX 97 75 97 75 98 / 0 0 0 0 0
PARIS, TX 97 76 96 75 96 / 10 10 10 0 0
DENTON, TX 98 77 98 78 99 / 10 10 10 0 0
MCKINNEY, TX 96 77 97 78 98 / 10 5 10 0 0
DALLAS, TX 99 80 99 81 100 / 10 5 5 0 0
TERRELL, TX 97 76 96 76 99 / 10 5 5 0 0
CORSICANA, TX 98 76 97 76 99 / 0 0 5 0 0
TEMPLE, TX 97 74 96 75 97 / 0 0 0 0 0
MINERAL WELLS, TX 96 75 96 75 98 / 10 5 5 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
82/58
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1022 AM EDT TUE JUL 21 2015
.SYNOPSIS...
A COLD FRONT THAT EXTENDED FROM ONTARIO TO THE CENTRAL UNITED
STATES EARLY THIS MORNING WILL MOVE SOUTHEAST TODAY AND TONIGHT
AND WILL TRAIL FROM THE CAROLINA COAST INTO THE SOUTHERN PLAINS BY
WEDNESDAY MORNING. HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT AND
WILL COVER THE MID ATLANTIC REGION ON THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1010 AM EDT TUESDAY...
CONVECTIVE CLUSTER FROM THIS MORNING HAS DISSIPATED INTO A PATCHY
AREA OF LIGHT RAIN...AND HAS EXITED THE NORTHEAST PART OF THE
FORECAST AREA. HEADING INTO THIS AFTERNOON...MUCH OF THE REGION
WILL BE RELATIVELY STABLE...BEING TEMPORARILY CAPPED FROM THE
EARLIER CONVECTION AND SLOW TO HEAT AT THE SURFACE TO DO PLENTY OF
REMAINING DEBRIS CLOUD COVER. LATER THIS AFTERNOON WITH THE
APPROACH AND ARRIVAL OF A COLD FRONT IS WHEN THE SHOWER AND
THUNDERSTORM ACTIVITY SHOULD REVAMP ITS COVERAGE. HOWEVER...THE
LATEST VERSION OF THE FORECAST WILL BE DOWNPLAYING THE CHANCE OF
PRECIPITATION A BIT AS COMPARED TO THE EARLIER NUMBERS THANKS TO
THE AFOREMENTIONED NEGATIVE INFLUENCES TO CONVECTION.
AS OF 400 AM EDT TUESDAY...
A SHORT WAVE CROSSING THE OHIO VALLEY WAS GENERATING CLUSTERS OF
SHOWERS AND THUNDERSTORMS FROM WEST VIRGINIA INTO NORTHERN
TENNESSEE. SHORT TERM GUIDANCE...INCLUDING THE LAST COUPLE RUNS OF
THE HRRR HAS THIS PRECIPITATION MOVING ACROSS THE WESTERN COUNTY
WARNING AREA BEFORE 8AM/12Z. A MAJORITY OF THESE SHOWERS AND
THUNDERSTORMS WILL IMPACT THE WESTERN AND NORTHERN COUNTY WARNING
AREA THIS MORNING AND ARE EXPECTED TO MOVE EAST BUT WEAKEN AS THEY
CROSS THE BLUE RIDGE.
A COLD FRONT TRAILED FROM ONTARIO TO CENTRAL MISSOURI EARLY THIS
MORNING. THIS FRONT WILL MOVE SOUTHEAST TODAY AND TONIGHT. SHOWERS
AND THUNDERSTORMS WILL DEVELOP ALONG THE FRONT THIS AFTERNOON
WHICH WILL RESULT IN ADDITIONAL THUNDERSTORMS IN THE FORECAST AREA
THIS AFTERNOON AND EVENING. HAVE USED THE TIMING OF THE GFS WHICH WAS
BRINGING THE FRONT THROUGH THE FORECAST AREA BEFORE MIDNIGHT...
SLIGHTLY FASTER THAN THE NAM GUIDANCE. SO INCREASED THE
PROBABILITY OF PRECIPITATION FOR MOST LOCATIONS TODAY...AND
REMOVED THE CHANCE OF RAIN LATE TONIGHT BEHIND THE FRONT. THREAT
FOR STORMS BECOMING SEVERE WILL BE LIMITED BY MODEST AMOUNTS OF
INSTABILITY AND SHEAR. BEST CHANCE IS IN THE PIEDMONT LATE THIS
AFTERNOON AND EVENING WHEN THE FRONT SHIFTS INTO THE LEE TROF.
WILL HAVE CLEARING BEHIND THE FRONT EAST OF THE BLUE RIDGE
OVERNIGHT...BUT UPSLOPE WINDS AND RESIDUAL LOW LEVEL MOISTURE WILL
HOLD CLOUDS IN THE WESTERN UPSLOPE AREAS THROUGH EARLY WEDNESDAY
MORNING.
STARTING OUT MILD THIS MORNING SO EVEN WITH THE CLOUD COVER AND
PRECIPITATION TEMPERATURES WILL RISE INTO THE 80S. STAYED CLOSE TO
BLEND OF MAV/MET GUIDANCE FOR MAXIMUM TEMPERATURES TODAY. HEAT
INDEX VALUES WILL BE AROUND 100 FOR A COUPLE HOURS IN THE PIEDMONT
THIS AFTERNOON...NOT HIGH ENOUGH OR LONG ENOUGH TO SUPPORT ANY
ADVISORY.
AIR MASS BEHIND THE FRONT IS SLIGHTLY COOLER WITH LOWS TONIGHT A
CATEGORY OR TWO BELOW TEMPERATURES THIS MORNING. THE MORE
SIGNIFICANT CHANGE IS SURFACE DEW POINTS DROPPING INTO THE UPPER
50S IN THE NORTHERN COUNTY WARNING AREA ALONG WITH PRECIPITABLE
WATER VALUES DROPPING BELOW ONE HALF INCH.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 310 AM EDT TUESDAY...
BROAD UPPER TROUGH CENTERED AROUND JAMES BAY EXTENDING ACROSS THE
EASTERN GREAT LAKES AND EASTERN CANADIAN WILL TRAVEL EAST DURING
THE PERIOD...AS AN UPPER RIDGE AMPLIFIES IN THE CENTRAL UNITED
STATES. THE SURFACE FRONTAL BOUNDARY WILL PUSH SOUTH OF OUR AREA
AND STALL...BUT SERVE AS A FOCUS FOR DIURNALLY DRIVEN CONVECTION.
DECREASED POPS WEDNESDAY...BUT STILL KEPT SOME ISOLATED TO WIDELY
SCATTERED POPS IN THE WEST WEDNESDAY AFTERNOON ACROSS THE HIGHER
TERRAIN. HIGH TEMPERATURES WEDNESDAY WILL VARY FROM THE THE UPPER
70S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. HELD ON
TO AN ISOLATED SHOWERS ACROSS SOUTHERN PORTIONS OF THE FORECAST
AREA ON WEDNESDAY NIGHT...AS A WAVE OF LOW PRESSURE DEVELOPS ALONG
THE STALLED FRONTAL ZONE WEDNESDAY NIGHT. LOW TEMPERATURES
WEDNESDAY NIGHT WILL RANGE FROM THE MID 50S IN THE MOUNTAINS TO
THE UPPER 60S IN THE PIEDMONT.
AN UPPER LEVEL DISTURBANCE WILL TRACK ALONG THE FRONT/BAROCLINIC
ZONE FROM WEST TO EAST THURSDAY. THERE IS THE POTENTIAL THAT THE
FRONT MAY LIFT NORTH AS WEAK WAVES OF LOW PRESSURE RIDE ALONG THE
BOUNDARY. MOISTURE WILL TRY AND SURGE BACK INTO THE PIEDMONT AND
NORTHWEST NORTH CAROLINA MOUNTAINS TO SOME DEGREE. THE PLACEMENT OF
THE LOW CENTER LOOKED A LITTLE FURTHER SOUTH AND EAST ON THIS MODEL
RUN. HOWEVER...GIVEN TIME OF YEAR AND DIFFERENTIAL HEATING...ALLOWED
FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAINLY ACROSS
THE PIEDMONT. AT ANY RATE...THE THREAT FOR SIGNIFICANT OR WIDESPREAD
CONVECTION AND SEVERE STORMS WILL REMAIN VERY LOW. HIGHS ON THURSDAY
WILL CLIMB INTO THE UPPER 70S IN THE WEST TO THE THE UPPER 80S IN
THE EAST. AS HIGH PRESSURE NUDGES IN FROM THE NORTHWEST...DRIER AIR
PUSHES ACROSS THE AREA THURSDAY NIGHT. LOW TEMPERATURES THURSDAY
NIGHT WILL DROP INTO THE MID 50S IN THE MOUNTAINS TO THE NEAR 70
DEGREES IN THE PIEDMONT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 350 PM EDT MONDAY...
THE BROAD NORTHEAST U.S./SOUTHEAST CANADIAN UPPER TROUGH WILL
CONTINUE TO SHIFT SLOWLY EAST THROUGH THE PERIOD. A STRONG
SUBTROPICAL RIDGE ANCHORED ACROSS TEXAS...WILL AMPLIFY INTO THE
GREAT LAKES...WITH A NOSE OF 850MB TEMPS EXCEEDING +20C
ACCOMPANYING IT. OUR REGION WILL LARGELY REMAIN UNDER NORTHWEST
FLOW ALOFT THROUGH THE PERIOD. MOST MODELS TAKE THE REMNANT
FRONTAL BOUNDARY FROM MID-WEEK AND THE ASSOCIATED WEAKNESS IN THE
UPPER-LEVELS SOUTHWARD INTO THE SOUTHEAST STATES...WHERE IT
APPEARS DESTINED TO CUTOFF AND LINGER IN THE EASTERN
GULF/FL/WESTERN ATLANTIC REGION. AS IT LINGERS IN THIS REGION INTO
NEXT WEEK...IT WILL NEED TO BE CAREFULLY MONITORED FOR ANY
POTENTIAL TROPICAL CHARACTERISTICS. GIVEN THE
AMPLIFYING/STRENGTHENING NW FLOW ALOFT...WE SHOULD SEE THE FRONTAL
BOUNDARY/BAROCLINIC ZONE PUSHED FAR ENOUGH SOUTH TO SHUT OFF THE
CONVECTION SATURDAY...OUTSIDE ISOLATED MOUNTAIN SHOWERS. BY
SUNDAY...A SHORT WAVE AND ASSOCIATED WEAK FRONT MOVES INTO THE
REGION FROM THE NORTHWEST...WHICH SHOULD INCREASE THE CHANCE FOR
SHOWERS/STORMS. THIS FEATURE MOVES EAST OF THE REGION MONDAY AS
THE UPPER RIDGE CONTINUES TO BUILD INTO THE REGION FROM THE WEST.
500MB HEIGHTS ARE SLATED TO RISE ABOVE 590DM AND 850MB TEMPS WILL
BEGIN TO CREEP ABOVE +20C ONCE AGAIN...ESPECIALLY IN THE WEST.
CONVECTION LOOKS TO BE MINIMAL PAST SUNDAY AT THIS POINT.
TEMPERATURES APPEAR DESTINED TO RETURN TO ABOVE NORMAL LEVELS BY
THE WEEKEND.
A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE
WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS
THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE
NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES
TO REACH THE REGION.
850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C
ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP
INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU
MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP
BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY
BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS
BY THE WEEKEND.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
AS OF 740 AM EDT TUESDAY...
CLUSTER OF LIGHT TO MODERATE SHOWERS OVER KLWB WILL BE EAST OF THE
AIRPORT BY THE START OF THE 12Z TAF FORECAST PERIOD. IFR TO MVFR
CEILINGS IN THE MOUNTAINS WILL BE SLOWER TO IMPROVE BUT MEDIUMCONFIDENCE
CONDITIONS WILL BE VFR BY 14Z.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL FORM THIS AFTERNOON
ALONG A COLD FRONT. A FEW OF THESE STORMS WILL BECOME STRONG AND
MAY PRODUCE GUSTY WINDS. USING THE TIMING OF THE GFS AND BRINING
THE FRONT THROUGH THE AREA THIS EVENING WHICH WILL TURN SURFACE
TO THE NORTHWEST. HIGH CONFIDENCE OF MORE IFR TO MVFR CLOUDS ON
THE WESTERN SLOPES OF THE MOUNTAINS OVERNIGHT.
EXTENDED AVIATION DISCUSSION...
THE COLD FRONT WILL ADVANCE SOUTH OF THE FORECAST AREA FOR
WEDNESDAY AND THURSDAY...BUT THEN BUCKLES NORTHWARD ON FRIDAY. SO
FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE PATCHY FOG
WEDNESDAY AND THURSDAY MORNING IN THE BCB/LWB AREA PENDING HOW
DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS
POSSIBLE FRIDAY AND SATURDAY IN THE MOUNTAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...KK
LONG TERM...RAB
AVIATION...AMS/NF
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
741 AM EDT TUE JUL 21 2015
.SYNOPSIS...
A COLD FRONT THAT EXTENDED FROM ONTARIO TO THE CENTRAL UNITED
STATES EARLY THIS MORNING WILL MOVE SOUTHEAST TODAY AND TONIGHT
AND WILL TRAIL FROM THE CAROLINA COAST INTO THE SOUTHERN PLAINS BY
WEDNESDAY MORNING. HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT AND
WILL COVER THE MID ATLANTIC REGION ON THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM EDT TUESDAY...
A SHORT WAVE CROSSING THE OHIO VALLEY WAS GENERATING CLUSTERS OF
SHOWERS AND THUNDERSTORMS FROM WEST VIRGINIA INTO NORTHERN
TENNESSEE. SHORT TERM GUIDANCE...INCLUDING THE LAST COUPLE RUNS OF
THE HRRR HAS THIS PRECIPITATION MOVING ACROSS THE WESTERN COUNTY
WARNING AREA BEFORE 8AM/12Z. A MAJORITY OF THESE SHOWERS AND
THUNDERSTORMS WILL IMPACT THE WESTERN AND NORTHERN COUNTY WARNING
AREA THIS MORNING AND ARE EXPECTED TO MOVE EAST BUT WEAKEN AS THEY
CROSS THE BLUE RIDGE.
A COLD FRONT TRAILED FROM ONTARIO TO CENTRAL MISSOURI EARLY THIS
MORNING. THIS FRONT WILL MOVE SOUTHEAST TODAY AND TONIGHT. SHOWERS
AND THUNDERSTORMS WILL DEVELOP ALONG THE FRONT THIS AFTERNOON
WHICH WILL RESULT IN ADDITIONAL THUNDERSTORMS IN THE FORECAST AREA
THIS AFTERNOON AND EVENING. HAVE USED THE TIMING OF THE GFS WHICH WAS
BRINGING THE FRONT THROUGH THE FORECAST AREA BEFORE MIDNIGHT...
SLIGHTLY FASTER THAN THE NAM GUIDANCE. SO INCREASED THE
PROBABILITY OF PRECIPITATION FOR MOST LOCATIONS TODAY...AND
REMOVED THE CHANCE OF RAIN LATE TONIGHT BEHIND THE FRONT. THREAT
FOR STORMS BECOMING SEVERE WILL BE LIMITED BY MODEST AMOUNTS OF
INSTABILITY AND SHEAR. BEST CHANCE IS IN THE PIEDMONT LATE THIS
AFTERNOON AND EVENING WHEN THE FRONT SHIFTS INTO THE LEE TROF.
WILL HAVE CLEARING BEHIND THE FRONT EAST OF THE BLUE RIDGE
OVERNIGHT...BUT UPSLOPE WINDS AND RESIDUAL LOW LEVEL MOISTURE WILL
HOLD CLOUDS IN THE WESTERN UPSLOPE AREAS THROUGH EARLY WEDNESDAY
MORNING.
STARTING OUT MILD THIS MORNING SO EVEN WITH THE CLOUD COVER AND
PRECIPITATION TEMPERATURES WILL RISE INTO THE 80S. STAYED CLOSE TO
BLEND OF MAV/MET GUIDANCE FOR MAXIMUM TEMPERATURES TODAY. HEAT
INDEX VALUES WILL BE AROUND 100 FOR A COUPLE HOURS IN THE PIEDMONT
THIS AFTERNOON...NOT HIGH ENOUGH OR LONG ENOUGH TO SUPPORT ANY
ADVISORY.
AIR MASS BEHIND THE FRONT IS SLIGHTLY COOLER WITH LOWS TONIGHT A
CATEGORY OR TWO BELOW TEMPERATURES THIS MORNING. THE MORE
SIGNIFICANT CHANGE IS SURFACE DEW POINTS DROPPING INTO THE UPPER
50S IN THE NORTHERN COUNTY WARNING AREA ALONG WITH PRECIPITABLE
WATER VALUES DROPPING BELOW ONE HALF INCH.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 310 AM EDT TUESDAY...
BROAD UPPER TROUGH CENTERED AROUND JAMES BAY EXTENDING ACROSS THE
EASTERN GREAT LAKES AND EASTERN CANADIAN WILL TRAVEL EAST DURING
THE PERIOD...AS AN UPPER RIDGE AMPLIFIES IN THE CENTRAL UNITED
STATES. THE SURFACE FRONTAL BOUNDARY WILL PUSH SOUTH OF OUR AREA
AND STALL...BUT SERVE AS A FOCUS FOR DIURNALLY DRIVEN CONVECTION.
DECREASED POPS WEDNESDAY...BUT STILL KEPT SOME ISOLATED TO WIDELY
SCATTERED POPS IN THE WEST WEDNESDAY AFTERNOON ACROSS THE HIGHER
TERRAIN. HIGH TEMPERATURES WEDNESDAY WILL VARY FROM THE THE UPPER
70S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. HELD ON
TO AN ISOLATED SHOWERS ACROSS SOUTHERN PORTIONS OF THE FORECAST
AREA ON WEDNESDAY NIGHT...AS A WAVE OF LOW PRESSURE DEVELOPS ALONG
THE STALLED FRONTAL ZONE WEDNESDAY NIGHT. LOW TEMPERATURES
WEDNESDAY NIGHT WILL RANGE FROM THE MID 50S IN THE MOUNTAINS TO
THE UPPER 60S IN THE PIEDMONT.
AN UPPER LEVEL DISTURBANCE WILL TRACK ALONG THE FRONT/BAROCLINIC
ZONE FROM WEST TO EAST THURSDAY. THERE IS THE POTENTIAL THAT THE
FRONT MAY LIFT NORTH AS WEAK WAVES OF LOW PRESSURE RIDE ALONG THE
BOUNDARY. MOISTURE WILL TRY AND SURGE BACK INTO THE PIEDMONT AND
NORTHWEST NORTH CAROLINA MOUNTAINS TO SOME DEGREE. THE PLACEMENT OF
THE LOW CENTER LOOKED A LITTLE FURTHER SOUTH AND EAST ON THIS MODEL
RUN. HOWEVER...GIVEN TIME OF YEAR AND DIFFERENTIAL HEATING...ALLOWED
FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAINLY ACROSS
THE PIEDMONT. AT ANY RATE...THE THREAT FOR SIGNIFICANT OR WIDESPREAD
CONVECTION AND SEVERE STORMS WILL REMAIN VERY LOW. HIGHS ON THURSDAY
WILL CLIMB INTO THE UPPER 70S IN THE WEST TO THE THE UPPER 80S IN
THE EAST. AS HIGH PRESSURE NUDGES IN FROM THE NORTHWEST...DRIER AIR
PUSHES ACROSS THE AREA THURSDAY NIGHT. LOW TEMPERATURES THURSDAY
NIGHT WILL DROP INTO THE MID 50S IN THE MOUNTAINS TO THE NEAR 70
DEGREES IN THE PIEDMONT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 350 PM EDT MONDAY...
THE BROAD NORTHEAST U.S./SOUTHEAST CANADIAN UPPER TROUGH WILL
CONTINUE TO SHIFT SLOWLY EAST THROUGH THE PERIOD. A STRONG
SUBTROPICAL RIDGE ANCHORED ACROSS TEXAS...WILL AMPLIFY INTO THE
GREAT LAKES...WITH A NOSE OF 850MB TEMPS EXCEEDING +20C
ACCOMPANYING IT. OUR REGION WILL LARGELY REMAIN UNDER NORTHWEST
FLOW ALOFT THROUGH THE PERIOD. MOST MODELS TAKE THE REMNANT
FRONTAL BOUNDARY FROM MID-WEEK AND THE ASSOCIATED WEAKNESS IN THE
UPPER-LEVELS SOUTHWARD INTO THE SOUTHEAST STATES...WHERE IT
APPEARS DESTINED TO CUTOFF AND LINGER IN THE EASTERN
GULF/FL/WESTERN ATLANTIC REGION. AS IT LINGERS IN THIS REGION INTO
NEXT WEEK...IT WILL NEED TO BE CAREFULLY MONITORED FOR ANY
POTENTIAL TROPICAL CHARACTERISTICS. GIVEN THE
AMPLIFYING/STRENGTHENING NW FLOW ALOFT...WE SHOULD SEE THE FRONTAL
BOUNDARY/BAROCLINIC ZONE PUSHED FAR ENOUGH SOUTH TO SHUT OFF THE
CONVECTION SATURDAY...OUTSIDE ISOLATED MOUNTAIN SHOWERS. BY
SUNDAY...A SHORT WAVE AND ASSOCIATED WEAK FRONT MOVES INTO THE
REGION FROM THE NORTHWEST...WHICH SHOULD INCREASE THE CHANCE FOR
SHOWERS/STORMS. THIS FEATURE MOVES EAST OF THE REGION MONDAY AS
THE UPPER RIDGE CONTINUES TO BUILD INTO THE REGION FROM THE WEST.
500MB HEIGHTS ARE SLATED TO RISE ABOVE 590DM AND 850MB TEMPS WILL
BEGIN TO CREEP ABOVE +20C ONCE AGAIN...ESPECIALLY IN THE WEST.
CONVECTION LOOKS TO BE MINIMAL PAST SUNDAY AT THIS POINT.
TEMPERATURES APPEAR DESTINED TO RETURN TO ABOVE NORMAL LEVELS BY
THE WEEKEND.
A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE
WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS
THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE
NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES
TO REACH THE REGION.
850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C
ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP
INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU
MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP
BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY
BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS
BY THE WEEKEND.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 740 AM EDT TUESDAY...
CLUSTER OF LIGHT TO MODERATE SHOWERS OVER KLWB WILL BE EAST OF THE
AIRPORT BY THE START OF THE 12Z TAF FORECAST PERIOD. IFR TO MVFR
CEILINGS IN THE MOUNTAINS WILL BE SLOWER TO IMPROVE BUT MEDIUMCONFIDENCE
CONDITIONS WILL BE VFR BY 14Z.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL FORM THIS AFTERNOON
ALONG A COLD FRONT. A FEW OF THESE STORMS WILL BECOME STRONG AND
MAY PRODUCE GUSTY WINDS. USING THE TIMING OF THE GFS AND BRINING
THE FRONT THROUGH THE AREA THIS EVENING WHICH WILL TURN SURFACE
TO THE NORTHWEST. HIGH CONFIDENCE OF MORE IFR TO MVFR CLOUDS ON
THE WESTERN SLOPES OF THE MOUNTAINS OVERNIGHT.
EXTENDED AVIATION DISCUSSION...
THE COLD FRONT WILL ADVANCE SOUTH OF THE FORECAST AREA FOR
WEDNESDAY AND THURSDAY...BUT THEN BUCKLES NORTHWARD ON FRIDAY. SO
FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE PATCHY FOG
WEDNESDAY AND THURSDAY MORNING IN THE BCB/LWB AREA PENDING HOW
DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS
POSSIBLE FRIDAY AND SATURDAY IN THE MOUNTAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...KK
LONG TERM...RAB
AVIATION...AMS/NF
AREA FORECAST DISCUSSION
NWS TUCSON AZ
142 PM MST TUE JUL 21 2015
.SYNOPSIS...DRIER AIR WILL KEEP ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS EAST AND SOUTH OF TUCSON THROUGH THIS EVENING.
MOISTURE WILL START TO INCREASE AS EARLY AS WEDNESDAY WITH CONTINUED
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS FROM TUCSON SOUTH
AND EASTWARD. EXPECT ISOLATED TO SCATTERED STORMS FOR MUCH OF
SOUTHEAST ARIZONA THURSDAY AND FRIDAY BEFORE A DRYING TREND RETURNS
FOR THE WEEKEND.
&&
.DISCUSSION...LATEST VISIBLE SATELLITE IMAGERY SHOWS CLEAR TO MOSTLY
CLEAR SKIES NORTH AND WEST OF TUCSON WITH PARTLY CLOUDY SKIES SOUTH
AND EAST OF TUCSON. KEMX RADAR IMAGERY DEPICTS ISOLATED SHOWERS AND
A FEW THUNDERSTORMS ACROSS COCHISE COUNTY BUT THESE HAVE BEEN
STRUGGLING OVER THE LAST HOUR OR SO. THE BEST MOISTURE AND
INSTABILITY WILL PERSIST ACROSS COCHISE AND EASTERN SANTA CRUZ
COUNTIES INTO THIS EVENING...WHERE ISOLATED SHOWERS AND A FEW
THUNDERSTORMS WILL CONTINUE. WE ANTICIPATE THE STORMS WILL DISSIPATE
AROUND SUNSET WITH THE LOSS OF DAYTIME HEATING. WE COULD SEE A
COMPLEX OF STORMS PERSIST LATER INTO THE EVENING ACROSS NORTHEAST
SONORA AS HINTED AT ON THE HRRR BUT SHOULD THIS SCENARIO OCCUR...IT
IS EXPECTED TO HAVE HAVE LITTLE IMPACT ON THIS FORECAST AREA.
IN THE LARGER SCALE...UPPER RIDGING CONTINUES ACROSS CENTRAL TEXAS
AND IS ORIENTED AS SUCH THAT THE FLOW WILL BECOME MORE SOUTHERLY
ACROSS THE REGION STARTING ON WEDNESDAY TO GRADUALLY IMPORT
ADDITIONAL MOISTURE TO THE REGION. WE THINK THAT THE FAVORED REGION
FOR STORMS ON WEDNESDAY WILL AGAIN BE SOUTH AND EAST OF TUCSON BUT
ISOLATED STORMS ARE LIKELY TO BE AS FAR NORTH AND WEST AS THE TUCSON
AREA BY WEDNESDAY AFTERNOON OR WEDNESDAY EVENING. EVEN HIGHER LEVELS
OF MOISTURE WILL MOVE IN THURSDAY /WITH PWAT VALUES INCREASING TO
ABOUT 1.5 INCHES/ ON SOUTHERLY FLOW. THIS SHOULD RESULT IN INCREASED
COVERAGE OF STORMS FOR MOST OF THE AREA EXCEPT FOR THE WESTERN
DESERTS. NOTE THOUGH THAT WITH SOUTHERLY UPPER LEVEL WINDS AS
WELL...STORM TOP ANVILS WILL BE BLOWING OUT AHEAD OF THE STORMS
WHICH IS A NEGATIVE FOR VALLEY STORMS AND LARGELY KILLED TUCSON
STORMS THIS PAST WEEKEND.
ADEQUATE MOISTURE WILL STILL PERSIST FRIDAY FOR A CHANCE OF SHOWERS
AND THUNDERSTORMS ACROSS MOST OF THE AREA. FOR THIS WEEKEND...DRIER
AIR WILL MOVE IN AS THE UPPER LEVEL RIDGE EXPANDS WESTWARD AND THE
ORIENTATION PUTS A BROAD RIDGE AXIS INTO ARIZONA. MEANWHILE...LOWER
TO MID LEVEL WESTERLY FLOW WILL TRANSPORT DRIER AIR IN FROM THE WEST
INTO SOUTHEAST ARIZONA RESULTING IN JUST A SLIGHT CHANCE OF STORMS
MAINLY FOR SOUTHERN AND EASTERN AREAS AGAIN. THIS WILL ALSO RESULT
IN WARMER TEMPERATURES FOR THE WEEKEND. BY EARLY NEXT WEEK...AS THE
FLOW BECOMES MORE SOUTH TO SOUTHEASTERLY AGAIN WITH PERHAPS SOME
INVERTED TROUGH INFLUENCE TO OUR SOUTH...MOISTURE WILL INCREASE AND
PERHAPS REVAMP SHOWER AND THUNDERSTORM COVERAGE.
&&
.AVIATION...VALID THRU 23/00Z.
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAINLY TO THE SOUTH
AND EAST OF KTUS THRU 22/03Z. BRIEF MVFR CONDITIONS POSSIBLE WITH
WIND GUSTS TO 35 KTS NEAR STRONGER STORMS FOR KDUG.
OTHERWISE...EXPECT DIMINISHED STORM ACTIVITY OVERNIGHT WITH FEW-SCT
CLOUDS AROUND 8-10K FT. NORMAL DIURNAL SURFACE WIND TRENDS WILL
PREVAIL OUTSIDE OF STORM INFLUENCE...GENERALLY UNDER 12 KTS.
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS INCREASING AFTER
22/20Z...AGAIN MAINLY SOUTH AND EAST OF KTUS. AVIATION DISCUSSION
NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...WARM TEMPERATURES AND A SLIGHTLY DRIER AIRMASS WILL
LIMIT CONVECTION TO AREAS MAINLY EAST AND SOUTH OF TUCSON THROUGH
WEDNESDAY. SOME INCREASED MOISTURE WILL RETURN TO THE AREA THURSDAY
AND FRIDAY. THIS WILL BRING ADDITIONAL COVERAGE OF SHOWERS AND
THUNDERSTORMS. BY THIS WEEKEND...SOMEWHAT DRIER AIR MAY REDUCE
THUNDERSTORM COVERAGE AGAIN. TERRAIN-DRIVEN 20-FT WINDS WILL
GENERALLY BE LESS THAN 15 MPH EXCEPT FOR SOME OCCASIONAL AFTERNOON
GUSTINESS DUE TO DAYTIME HEATING. A FEW OF THE STRONGER
THUNDERSTORMS MAY PRODUCE WIND GUSTS TO AROUND 40 MPH.
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...GL
AVIATION/FIRE WEATHER...RH
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS TUCSON AZ
914 AM MST TUE JUL 21 2015
.SYNOPSIS...A DRYING TREND WILL PUSH THE BEST CHANCES OF
THUNDERSTORMS EAST AND SOUTH OF TUCSON THROUGH WEDNESDAY. A
SOUTHERLY TO SOUTHEASTERLY FLOW SHOULD RETURN MOISTURE TO THE AREA
WEDNESDAY NIGHT INTO THURSDAY. A SLIGHT DOWN SWING IN ACTIVITY IS
EXPECTED OVER THE WEEKEND...BEFORE PICKING BACK UP AGAIN EARLY NEXT
WEEK. EVEN SO...SHOWERS AND STORMS SHOULD BE CONFINED TO AREAS
MAINLY BETWEEN TUCSON AND THE NEW MEXICO BORDER EACH DAY.
&&
.DISCUSSION...CLEAR SKIES ACROSS SOUTHEAST ARIZONA THIS MORNING WITH
SOUTHWESTERLY FLOW ALOFT OVER THE STATE. LATEST WV IMAGERY SHOWS DRY
AIR ALOFT OVER MUCH OF THE STATE WITH A WELL DEFINED DEMARCATION
LINE BETWEEN THIS DRY AIR AND MORE MOIST AIR ON A LINE FROM NEAR
SIERRA VISTA TO CLIFTON. MEANWHILE...PRECIPITABLE WATER VALUES FROM
VARIOUS SOURCES RANGE FROM ABOUT 1 TO 1.25 INCHES ACROSS THE AREA
WHICH IS A LITTLE BIT DRIER THAN 24 HOURS AGO. THE DEMARCATION LINE
SEEN ON THE WV IMAGERY IS OFTEN WHERE WE SEE CONVECTION INITIATE AND
THIS IS SUPPORTED WELL BY THE VARIOUS CONVECTIVE RESOLVING MODELS
INCLUDING THE HRRR AND UOFA WRF MODEL GUIDANCE WHICH TARGET SANTA
CRUZ AND SOUTHERN COCHISE COUNTY FOR ISOLATED TO SCATTERED SHOWERS
AND THUNDERSTORMS. IN ADDITION...THE BEST INSTABILITY WITH MUCAPE
VALUES ABOUT 1000-2000 J/KG ARE PROGGED ACROSS THIS AREA AS WELL.
THUS...THE CURRENT FORECAST OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS SOUTH AND EAST OF TUCSON LOOKS GOOD...TRAILING OFF
CONSIDERABLY TO JUST BELOW 10 PERCENT IN TUCSON. ALL IN
ALL...COVERAGE SHOULD BE FAIRLY SIMILAR TO WHAT WE SAW YESTERDAY.
NOTE THAT THE 12Z NAM IS DEVELOPING A BIG CONVECTIVE COMPLEX JUST
SOUTH OF THE INTERNATIONAL BORDER ACROSS FROM COCHISE COUNTY
TONIGHT...BUT DON`T SEE ANY REAL SUPPORT FOR THIS SCENARIO SO WILL
DISCOUNT IT. MADE SOME MINOR TWEAKS TO THE POP FORECAST THIS
AFTERNOON...OTHERWISE FORECAST REMAINS UNCHANGED. SEE PREVIOUS
DISCUSSION BELOW FOR ADDITIONAL INFORMATION.
&&
.AVIATION...VALID THRU 22/12Z.
ISOLATED TO SCATTERED TSRA/SHRA MAINLY EAST AND SOUTH OF KTUS AND
ESP NEAR TERRAIN AFT 21/18Z. BRIEF MVFR CIGS/VSBYS AND GUSTS TO 35
KTS PSBL TIL 22/03Z IN AND AROUND THE STRONGER TSRA. EXPECT FEW-SCT
CLOUDS AT 8-10K FT WITH MORE COVERAGE DURING THE AFTERNOON/EVENING
HOURS. SFC WINDS DIURNALLY DRIVEN AND GENERALLY LESS THAN 12 KTS
OUTSIDE OF ANY TSRA/SHRA. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...WARM TEMPERATURES AND A SLIGHTLY DRIER AIRMASS WILL
LIMIT CONVECTION TO AREAS MAINLY EAST AND SOUTH OF TUCSON THROUGH
WEDNESDAY. SOME MOISTURE WILL ATTEMPT TO RETURN TO THE AREA AS EARLY
AS THURSDAY...BUT ESPECIALLY FROM FRIDAY ONWARD. THIS WILL BRING
BACK AN INCREASED CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE
COMING WEEKEND...BUT ESPECIALLY BY EARLY NEXT WEEK. TERRAIN-DRIVEN
20-FT WINDS WILL GENERALLY BE LESS THAN 15 MPH EXCEPT FOR SOME
OCCASIONAL AFTERNOON GUSTINESS DUE TO DAYTIME HEATING. A FEW OF THE
STRONGER THUNDERSTORMS MAY PRODUCE WIND GUSTS TO AROUND 40 MPH.
&&
.PREV DISCUSSION...DURING THE MIDDLE OF THE WEEK THE MODELS KEEP THE
HIGH QUASI-STATIONARY OVER THE SOUTHERN PLAINS...WITH THE PACIFIC
TROUGH TO OUR NORTHWEST. DISTURBANCES MOVING UP TO THE NORTH ON THE
WESTERN FLANK OF THE HIGH ARE EXPECTED TO INCREASE RAIN CHANCES A
BIT AS THE MOISTURE PLUME ON THE WEST SIDE OF THE HIGH IS EXPECTED
TO MOVE ACROSS EASTERN PARTS OF ARIZONA AND A LARGE PART OF NEW
MEXICO. MOS NUMBERS INDICATE THAT THE NAM IS THE WETTEST...WHILE THE
ECMWF IS THE DRIEST. HOWEVER...THE NAM/GFS/ECMWF ALL POINT TO AN
UPSWING IN ACTIVITY WEDNESDAY NIGHT INTO THURSDAY. I DID MAKE
ADJUSTMENTS TO THE POP FORECAST TO ACCOUNT FOR THIS...SO FOR NOW I
SHOW LOW END CHANCES FOR AREAS MAINLY FROM TUCSON TO NOGALES TO
DOUGLAS TO WILLCOX...AS WELL AS CHANCE POPS OVER THE WHITES. OVER
THE FAR WESTERN DESERTS ONLY `SILENT` SINGLE DIGIT POPS FOR
WEDNESDAY NIGHT INTO THURSDAY.
BY LATE IN THE WEEK THE MODELS INDICATE THAT THE TROUGH AXIS OVER
NORTHERN CALIFORNIA WILL MOVE TO A POSITION OVER THE CENTRAL PORTION
OF THE STATE. IN RESPONSE TO THIS...MOISTURE IS PROGGED TO BE
SHUNTED EAST AND SOUTH OF THIS AREA FOR A SLIGHT DECREASE IN
THUNDERSTORM ACTIVITY DURING THE LATTER PART OF THE WEEK AND INTO
THE WEEKEND. BY EARLY NEXT WEEK A MAJOR TROUGH MAKES ITS WAY INTO
THE PACIFIC NORTHWEST WITH THE RIDGE STILL OVER THE CENTRAL AND
SOUTHERN PLAINS...BUT WITH MODELS ADVERTISING AN INVERTED TROUGH
ROUNDING THE SOUTHERN PERIPHERY OF THE HIGH AND SLIDING WEST OR
NORTHWEST ACROSS NORTHERN MEXICO. THIS SHOULD RESULT IN AN INCREASE
FOR SHOWERS AND THUNDERSTORMS DURING THE EARLY PART OF NEXT WEEK.
FOR TUCSON...HIGH TEMPS WILL GENERALLY BE A DEGREE OR TWO EITHER
SIDE OF NORMAL TODAY THROUGH FRIDAY...THEN 3 TO 5 DEGS ABOVE NORMAL
THEREAFTER. LOWS WILL BE ABOUT 3 TO 5 DEGS ABOVE NORMAL EACH
MORNING...ALTHOUGH THE WARMEST MORNINGS WILL LIKELY OCCUR SUNDAY AND
MONDAY.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...GL
AVIATION/FIRE WEATHER...FRENCH
PREV DISCUSSION...MOLLERE
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
917 AM PDT TUE JUL 21 2015
.SYNOPSIS...LINGERING MOISTURE FROM THE REMNANTS OF DOLORES WILL
RESULT IN A CHANCE OF SHOWERS AND THUNDERSTORMS OVER THE
SOUTHEASTERN PORTIONS OF THE REGION THROUGH THE AFTERNOON.
OTHERWISE...COOLER CONDITIONS CAN BE EXPECTED THROUGH THURSDAY.
DRY WEATHER CONDITIONS AND NEAR NORMAL TEMPERATURES ARE LIKELY FOR
LATE WEEK AND INTO THE UPCOMING WEEKEND.
&&
.DISCUSSION...AS OF 09:15 AM PDT TUESDAY...THE MARINE LAYER MADE
A RAPID RETURN OVERNIGHT AND IS AROUND 1500 FEET DEEP THIS
MORNING. AS A RESULT...THE MARINE INFLUENCE HAS TEMPERATURES DOWN
7 TO 13 DEGREES COMPARED TO 24 HOURS AGO FOR MOST LOCATIONS. DO
EXPECT COASTAL CLOUDS TO BURN-OFF INLAND WITH MOSTLY SUNNY
CONDITIONS THIS AFTERNOON. HAVE MADE MINOR ADJUSTMENTS TO ACCOUNT
FOR A SLIGHT CHANCE OF SHOWERS OVER NAPA AND CONTRA COSTA COUNTIES
AS EARLY RADAR RETURNS SUGGESTED A FEW SHOWERS OVER SOLANO COUNTY
HEADING WESTWARD. THIS IS LIKELY DUE TO A WEAK MID/UPPER LEVEL
DISTURBANCE INTERACTING WITH ABUNDANT MOISTURE ALOFT. WILL
CONTINUE WITH THE SLIGHT CHANCE OF SHOWERS AND/OR THUNDERSTORMS
OVER THE INLAND...SOUTHEASTERN PORTION OF THE REGION THIS
AFTERNOON AND EVENING AS THE ATMOSPHERE BECOMES MORE UNSTABLE AND
LINGERING MOISTURE REMAINS IN PLACE. OTHERWISE...MOST LOCATIONS
CAN EXPECT TYPICAL MID/LATE JULY WEATHER FOR THE NEXT FEW DAYS.
&&
.PREV DISCUSSION...AS OF 3:00 AM PDT TUESDAY...AFTER A COUPLE OF
VERY WARM AND FAIRLY HUMID DAYS ACROSS OUR REGION TODAY WILL FEEL
QUITE A BIT COOLER. IN FACT...24 HOUR CHANGE PRODUCT ALREADY
SHOWS THE BIG CHANGE WITH ALMOST ALL SPOTS 7 TO 13 DEGREES UNDER
VALUES FROM YESTERDAY ALONG WITH SLIGHTLY LOWER DEW POINTS.
SYNOPTICALLY REMNANTS FROM FORMER HURRICANE DOLORES CONTINUES TO
SPIN OFF TO OUR SOUTHWEST. DUE TO SOME INSTABILITY PLUS MID LEVEL
MOISTURE THERE REMAINS AN OUTSIDE CHANCE OF A FEW SHOWERS OR EVEN
A THUNDERSTORM FIRING UP OVER PARTS OF MONTEREY AND SAN BENITO
COUNTIES. WILL KEEP POPS AROUND 20 PERCENT FOR THAT AREA. FOR THE
REST OF THE CWA LOOK FOR DRY CONDITIONS WITH HIGHS 4 TO 8 DEGREES
COOLER THAN YESTERDAY.
MODELS REMAIN IN GOOD AGREEMENT THAT A LONGWAVE TROF WILL MOVE IN
FROM THE NORTH AND STRETCH FROM NORCAL INTO CENTRAL CANADA
STARTING TONIGHT. THIS FEATURE IS EXPECTED TO REMAIN NEARLY
STATIONARY THROUGH AT LEAST THURSDAY WHICH WILL HELP TO DROP TEMPS
TO COOLER THAN NORMAL VALUES FOR ALMOST ALL SPOTS. SPOTTY COASTAL
DRIZZLE WILL ALSO BE POSSIBLE EACH NIGHT INTO THE MORNING HOURS.
THE TROF WILL LIFT TO THE NORTHEAST FRIDAY AND SATURDAY AS A
RIDGE OF HIGH PRESSURE BUILDS FROM THE SOUTHEAST. THIS WILL HELP
TO PUSH HIGHS CLOSER TO NORMAL BY THE END OF THE WEEK GOING INTO
THE START OF NEXT WEEK.
&&
.AVIATION...AS OF 4:50 AM PDT TUESDAY... A RELATIVELY SHALLOW
MARINE LAYER HAS CREPT INTO THE INLAND VALLEYS THIS MORNING...
LEADING TO LIFR TO MVFR CIGS ACROSS REGIONAL TAF SITES. THE SFO
TO SAC ONSHORE GRADIENT IS MORE THAN TWICE AS LARGE VERSUS 24
HOURS AGO... WHICH CONTRIBUTED TO THE INCREASED ONSHORE PUSH.
LARGE SPREAD OF MODEL OUPUT IS LEADING TO A LOW TO MODERATE
CONFIDENCE FORECAST FOR MORNING MIXOUT TIMES. SATELLITE IMAGERY
SHOWS A DECK OF MID LEVEL CLOUDS LEFT OVER FROM YESTERDAYS SIERRA
CONVECTION ADVANCING FROM THE EAST. HRRR MODEL SUGGESTING THAT A
FEW ISOLATED AREAS OF -RA/DZ MAY BE POSSIBLE FROM THIS DECK...
BUT EXPECT VIRGA TO BE PREDOMINATE WX COND.
VICINITY OF KSFO... LOW TO MODERATE CONFIDENCE. IFR CIGS THROUGH
1630-17Z. MVFR POSSIBLE THROUGH 1730-19Z. ADVANCING MID LEVEL
MOISTURE FROM THE EAST MAY LEAD TO -RA IN THE VICINITY BTWN
15-19Z. ONSHORE WINDS 15-20KT WITH GUSTS TO 25KT THIS AFTERNOON.
KSFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS... MODERATE CONFIDENCE. WIDESPREAD IFR
CIGS THROUGH 18Z... WITH LOCAL IFR/MVFR CIGS LINGERING TO 20-21Z.
EARLIER RETURN OF IFR CIGS TONIGHT. ONSHORE WINDS 10 TO 15KT.
&&
.MARINE...AS OF 09:15 AM PDT TUESDAY...HIGH PRESSURE WILL REMAIN
OFF THE PACIFIC NORTHWEST COAST THROUGH FRIDAY. THIS WILL KEEP
MODERATE NORTHWEST WINDS ACROSS THE COASTAL WATERS WITH THE
STRONGEST WINDS OVER THE NORTHERN WATERS.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 3 PM
SCA...PT ARENA TO PT REYES 0-10 NM FROM 3 PM
&&
$$
PUBLIC FORECAST: RGASS
AVIATION: DRP
MARINE: W PI
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1210 PM MDT TUE JUL 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 346 AM MDT TUE JUL 21 2015
...STRONG TO SEVERE STORMS POSSIBLE ACROSS THE EASTERN MTS AND
PLAINS...
CURRENT WATER VAPOR IMAGERY INDICATING INCREASING SOUTH TO SOUTHWEST
FLOW ALOFT ACROSS THE REGION AS A SHORT WAVE TROUGH IS TRANSLATING
ACROSS THE SOUTHERN CALIFORNIA COAST AND SOUTHERN GREAT BASIN AT
THIS TIME. WATER VAPOR IMAGERY IS INDICATING THE MONSOONAL MOISTURE
PLUME ACROSS AT THE SOUTHERN AND CENTRAL ROCKIES WITH MUCH DRIER AIR
WITHIN THE FLOW ALOFT WORKING ITS WAY ACROSS THE DESERT SW AND INTO
WESTERN COLORADO AT THIS TIME. MINOR EMBEDDED DISTURBANCES ARE
EVIDENT WITHIN THE SOUTH TO SOUTHERLY FLOW ACROSS THE SOUTHERN
ROCKIES...WITH AN MCV AND REMNANTS OF LAST NIGHTS MCS CAN ALSO BE
SEEN ACROSS THE OKLAHOMA PANHANDLE AT THIS TIME.
COMPLEX FORECAST THIS MORNING WITH LATEST MODELS...EVEN THE HIGHER
RES HRRR AND RUC...NOT DOING WELL AND CONTINUE TO PRINT OUT
CONVECTIVE QPF BULLSEYES ACROSS THE AREA EARLY THIS MORNING. AT ANY
RATE...SHOULD SEE LEE TROUGHING ACROSS THE I-25 CORRIDOR THROUGH THE
MORNING AND EARLY AFTERNOON AS SOUTHWEST FLOW ALOFT CONTINUES TO
INCREASE AHEAD OF SOUTHERN CALIFORNIA SHORT WAVE. THIS WILL LEAD TO
INCREASING SOUTH TO SOUTHEAST LOW TO MID LEVEL UPSLOPE FLOW ACROSS
THE EASTERN MTS THROUGH THE UPPER ARKANSAS RIVER VALLEY. WITH AMPLE
MOISTURE AND POSSIBLE ADDED LIFT FROM THE SOUTHERN ROCKIES MINOR
DISTURBANCES LIFTING NORTH ACROSS SOUTH CENTRAL COLORADO...SHOULD
SEE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS OVER AND NEAR
THE HIGHER TERRAIN THROUGH THE LATE MORNING AND AFTERNOON.
FURTHER EAST ACROSS THE I-25 CORRIDOR AND THE SOUTHEASTERN
PLAINS...SUBSIDENCE ON THE BACKSIDE OF THE OK PANHANDLE MCV COULD
KEEP CONVECTION AT BAY THROUGH THE MORNING...WITH COOL UPSLOPE FLOW
ALSO POSSIBLY KEEPING CONDITIONS TOO STABLE THIS AFTERNOON...LEADING
TO EASTERN MOUNTAIN STORMS WEAKENING AS THEY PUSH EAST OFF THE
HIGHER TERRAIN. HOWEVER...IF ENOUGH INSTABILITY CAN BE
GENERATED...THERE WILL BE ENOUGH SHEAR FOR SUPERCELL DEVELOPMENT
SUPPORTING STRONG TO SEVERE STORMS PRODUCING LARGE HAIL TO AROUND AN
INCH IN DIAMETER AND DAMAGING WIND GUSTS IN EXCESS OF 60 MPH.
STORMS THAT DO DEVELOP WILL ALSO BE CAPABLE OF PRODUCING HEAVY
RAINFALL...THOUGH WITH INCREASING FLOW ALOFT...STORMS WILL BE MOVING
AT A GOOD CLIP TO LIMIT FLASH FLOODING POTENTIAL. THE ONE CAVET WILL
BE THE POTENTIAL FOR TRAINING STORMS...ESPECIALLY ACROSS THE EASTERN
MTS AND PALMER DVD...WITH SOUTH TO SOUTHEAST LOW AND MID LEVEL FLOW.
WITH THAT SAID...CONSIDERED ISSUING A FLASH FLOOD WATCH FOR THE BURN
SCARS IN EL PASO COUNTY...BUT THERE REMAINS TOO MANY QUESTION ON
GENERATING ENOUGH INSTABILITY TO ISSUE AT THIS TIME.
DRIER AIR ALOFT CONTINUES TO WORK INTO THE AREA TONIGHT AS SHORT
WAVE TRANSLATES ACROSS THE CENTRAL ROCKIES. LEE TROUGHING LIFTS OUT
ACROSS THE EASTERN PLAINS AND COULD BE A FOCUS CONVECTION THIS
EVENING WITH STORMS DIMINISHING FROM WEST TO EAST THROUGH THE LATE
EVENING AND OVERNIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 346 AM MDT TUE JUL 21 2015
WESTERLY MID/UPPER LEVEL FLOW ON WED ALLOWS PLUME OF RATHER DEEP
DRY AIR TO SPREAD ACROSS THE STATE...LEADING TO A PRONOUNCED
DOWNTURN IN CONVECTION ALL AREAS WED AFTERNOON AND EVENING. STILL
SOME SHALLOW RESIDUAL MOISTURE HANGING ON OVER THE
MOUNTAINS...WHICH WILL LEAD TO SOME WEAK TSRA WED AFTERNOON OVER
THE HIGHER TERRAIN...THOUGH OVERALL STRENGTH/COVERAGE OF STORMS
WILL BE PALTRY. MAX TEMPS WED WILL CLIMB CONSIDERABLY WITH DRY
AIR AND DOWNSLOPE GRADIENT...AND 90S WILL REAPPEAR ACROSS MOST OF
THE SOUTHEAST PLAINS. DRY AIR PERSISTS ON THU WITH A REPEAT OF
WEAK MOUNTAIN CONVECTION IN THE AFTERNOON...WITH MAX TEMPS ADDING
ANOTHER 3-5F OVER THE PLAINS...1-3F WARMER ACROSS THE HIGHER
ELEVATIONS. WESTERLY FLOW ALOFT INCREASES FRI AS UPPER WAVE MOVES
THROUGH THE NORTHERN ROCKIES INTO THE HIGH PLAINS BY EVENING. WEAK
COLD FRONT WILL PUSH THROUGH THE PLAINS DURING THE DAY...BUT
MOISTURE IS LACKING AND POST FRONTAL UPSLOPE IS INITIALLY WEAK...SO
DOUBTFUL BOUNDARY WILL HAVE MUCH IMPACT ON PRECIP CHANCES...AND
WILL KEEP JUST THE USUAL LOW POPS FOR ISOLATED STORMS OVER THE
MOUNTAINS.
UPPER RIDGE OVER TEXAS BEGINS TO SLOWLY DRIFT EASTWARD OVER THE
WEEKEND...WHICH WILL ALLOW SOUTHERLY FLOW TO REDEVELOP OVER THE
DESERT SW...LEADING TO A RENEWED INFLUX OF MOISTURE AND INCREASING
TSRA CHANCES MOST LOCATIONS BEGINNING SAT AFTERNOON/EVENING AND
CONTINUING INTO SUN. RIDGE THEN REMAINS EAST OF THE AREA NEXT
WEEK...WITH FAIRLY STRONG MONSOON TAP MON PERSISTING INTO MID
WEEK. MAX TEMPS WILL LIKELY PEAK ON FRI...THEN DRIFT SLOWLY
DOWNWARD THROUGH THE WEEKEND INTO NEXT WEEK AS AIR MASS MOISTENS
AND CONVECTIVE CLOUDINESS SHAVES A FEW DEGF OFF OF DAYTIME
READINGS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1140 AM MDT TUE JUL 21 2015
PLENTY OF MOISTURE IN PLACE TO PRODUCE WIDESPREAD CONVECTION OVER
AND NEAR THE HIGHER TERRAIN THIS AFTN AND EVE. STORMS THAT
DEVELOP MAY PRODUCE PERIODS OF LOCALLY HEAVY RAINFALL AND MVFR TO IFR
CONDITIONS AT TERMINALS. COULD ALSO SEE STRONG TO SEVERE STORMS
ALONG THE I25 CORRIDOR AND PORTIONS OF THE E PLAINS THROUGH THIS
EVENING. LARGE HAIL TO AROUND AN INCH IN DIAMETER AND GUSTY
OUTFLOW WINDS TO AROUND 60 MPH WILL BE POSSIBLE FOR KCOS SOUTH TO
KTAD...AND EAST TO KLHX. STORMS ARE EXPECTED TO DIMINISH FROM
WEST TO EAST THROUGH THE EVENING HOURS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MW
LONG TERM...PETERSEN
AVIATION...MOORE
AREA FORECAST DISCUSSION
NWS ALBANY NY
141 PM EDT TUE JUL 21 2015
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE REGION THIS AFTERNOON...BRINGING
A CHANCE FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD
FROM CENTRAL CANADA INTO THE UPPER GREAT PLAINS WEDNESDAY...AND
DRIFT INTO THE GREAT LAKES AND OHIO VALLEY BY WEEKS END. IT WILL
USHER IN A COOLER AND LESS HUMID AIR MASS INTO THE REGION FOR THE
REST OF THE WEEK. AT THE SAME TIME A LARGE WEATHER DISTURBANCE
ALOFT WILL DROP FROM QUEBEC INTO THE MARITIMES WEDNESDAY INTO
FRIDAY...WITH INCREASING CLOUDS AND SHOWERS...MAINLY NORTH OF I90.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM EDT...A STATIONARY BOUNDARY WAS DRAPED ACROSS LONG
ISLAND WITH A WAVE OF LOW PRESSURE OVER CAPE COD. THIS HAS
RESULTED IN CLOUD COVER ACROSS THE FAR SE PTN OF THE FA. MEANWHILE
A STRONG COLD FRONT WAS MOVING SOUTHEAST FROM FAR NRN AND CNTRL NY.
THE MAIN FOCUS FOR THIS AFT INTO ERLY THIS EVENG CONTS TO BE THE
CHANCES FOR SHOWERS AND THUNDERSTORMS AHEAD OF THE COLD FRONT.
THE HRRR COL MAX REFLECTIVITY HAS THE CURRENT LINE OF SHOWERS AND
EMBEDDED THUNDERSTORMS ANALYZED WELL. PRECIP HAS ALREADY ARRIVED
ACROSS FAR NW PTN OF THE FA AND REACHES THE GREATER CAPITAL
DISTRICT BTWN 3 AND 4 PM. AT THAT TIME FRONT WEAKENS SOMEWHAT AND
PRECIPITATION BECOMES MORE DIFFUSE. MEANWHILE...SOME INDICATIONS
OF STRONGER TSRA DEVELOPING ALONG OCCLUDED FRONT/TROUGH ACROSS
SOUTHERN CWA TOWARD THIS TIME. HAVE ATTEMPTED TO TIME THE PRECIP
INTO AND THROUGH THE CWA IN THE GRIDS /WITH LIKELY POPS/ RELYING
ON HRRR.
AS FAR AS SEVERE CHANCES GO...SPC HAS A MARGINAL RISK FOR
SEVERE THUNDERSTORMS ACRS OUR CWA. THIS STILL LOOKS APPROPRIATE.
FAIRLY ANEMIC THERMODYNAMIC PARAMETERS ON 12Z ALY SOUNDING.
HOWEVER...BUF SOUNDING SHOWING BETTER INSTABILITY. 0-6KM SHEAR
RESPECTABLE AT ALY WITH 38 KNOTS NOTED. WEAKER AT BUF. MID LEVEL
LAPSE RATES NOT PARTICULARLY IMPRESSIVE EITHER. VIS SATELLITE
REVEALS QUITE A BIT OF SUNSHINE NOW ACROSS MARGINAL RISK AREA. WE
WILL BE KEEPING A CLOSE EYE ON MESOSCALE ANALYSIS AND THE RADAR
THIS AFTERNOON.
TEMPERATURES WILL STILL BE VERY WARM AHEAD OF THE FRONT...WITH
MID TO UPPER 80S EXPECTED FROM THE HUDSON VALLEY EASTWARD. AREAS
NEAR POUGHKEEPSIE WILL LIKELY REACH 90 DEGREES FOR THE THIRD
CONSECUTIVE DAY.
SHOWERS AND STORMS WILL LIKELY DECREASE IN COVERAGE AFTER DARK DUE
TO LOSS OF DAYTIME HEATING AND INSTABILITY...ALTHOUGH THE COLD FRONT
WILL STILL BE MOVING THROUGH AREAS SOUTH AND EAST OF ALBANY...SO
WILL MAINTAIN SLIGHT TO LOW CHANCE POPS INTO THE EVENING. ANY
SHOWERS WILL DISSIPATE BY MIDNIGHT...WITH DRY CONDITIONS THROUGH THE
REST OF THE OVERNIGHT HOURS AS NORTHWEST FLOW DEVELOPS BEHIND THE
COLD FRONT. TEMPS BY EARLY WEDNESDAY MORNING WILL BE COOLER THAN
RECENT NIGHTS WITH GENERALLY 50S TO LOWER 60S ACROSS THE REGION.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
GENERALLY AGREEMENT AMONG THE MDL SUITE THROUGH THIS PERIOD AS WX
PATTERN OVER E NA WILL BE DOMINATED BY A 500 HPA TROF CUT OFF OVER
QB...THAT DIVES SE INTO THE MARITIMES BY FRI. INITIALLY SFC HIGH
PRESSURE BUILDS FM CENTRAL CANADA INTO THE UPPER GRT PLAINS
WED...AS TUES SFC LOW AND CDFNT DEPART OFFSHORE.
BY WED AFTN COOLING ALOFT AS 500HPA TEMPS FALL TO -13C TO -16C AND
JETS MOVING AROUND BASE OF 500HPA CUT OFF SAGGING SOUTH INTO FCA
BEGIN TO IMPACT RGN WITH VARYING DEGREES OF CLOUDS AND SCT MAINLY
DIURNALLY DRIVEN -SHRA N TIER AND OVER HIR TRRN. WOULDN`T RULE
OUT SOME GRAUPAL IN THESE -SHRA OVER HIR TRRN. THE NAM IS MORE
AGGRESSIVE WITH THIS PATTERN INTO THE FCA BY WED AFTN...THE GFS
HOLDING OFF TILL THU. BUT THE TREND IS STILL THE SAME.
AT THE SAME TIME IN RESPONSE TO THE DIVING 500 HPA TROF...SFC LOW
PRESSURE OVER MARITIMES DEEPENS...AND WIND GRADIENT INCRG OVR RGN
ESPECIALLY IN THE AFTN...RESULTING IN BREEZY CONDS AT TIMES.
SO OVERALL A PERIOD OF PC TO AT TIMES MC SKIES N WITH SCT SHRA
EACH DAY...DIURNALLY DRIVEN. GENERALLY MS SOUTH OF I90. TEMPS WILL
BE 3-5 DEG BLO NORMALS...WITH VERY COMFORTABLE RH LEVELS AS TD
FALL TO THE UPPER 40S AND 50S. FRIDAY NIGHT 500 HPA TROF FINALLY
SLIDES OFFSHORE AS SFC HIGH SETTLES OVER NE USA INTO QB.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
ECMWF/GFS/HPC PRETTY MUCH IN AGREEMENT.
SATURDAY BRINGS A 500 HPA RIDGE INTO THE REGION AS SFC HIGH
SLIDES OFFSHORE. FOR THE MOST PART IT SHOULD BE A DRY DAY WITH
TEMPS NR TO SLIGHTLY BLO NORMAL.
AFT SAT THE REST OF THE EFP WILL BE AN UNSETTLED PERIOD. AS THE
500HPA RIDGE MOVES EAST OF RGN SAT NIGHT CLOUDS INCR. AT THE SFC
A WMFNT PUSHES TO ABOUT CLE- ORF...AND RESULT IS INCG CHC
SHRA/TSTMS SAT NT...AND A THREAT OF SHRA/TSTMS INTO MON.
BY SUN MRNG THE 500HPA RIDGE IS OFFSHORE...AND THE 500HPA FLOW
HAS BCM NW. THIS LEAVES THE SFC HIGH OFFSHORE...WEAK WAA OVER
FCA...AND THE WMFNT ONLY MVNG SLIGHTLY NE THROUGH MON. COMBINATION
OF CONVECTIVE DEBRIS...AND SOME MID LEVEL DRYING WILL RESULT IN
VRBL CLOUDS AND MAYBE SOME SUNNY PERIODS SUN AND MON. DIURNALLY
DRIVEN ROUNDS OF -SHRA/TSTMS WILL AGAIN BE POSSIBLE SUN AND AGAIN
MON.
TEMPS WILL REMAIN NR TO SLIGHTLY BLO NORMALS...BUT TD WILL CREEP
SLOWLY UP THROUGH THE 50S AND RETURN TO THE 60S BY MON. WILL
POPULATE WITH HPC GUID.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
A COLD FRONT WILL MOVE ACROSS ERN NY AND WRN NEW ENGLAND THIS
AFTERNOON INTO THE EARLY EVENING. AN UPPER LEVEL LOW WILL BE NORTH
OF THE REGION OVERNIGHT INTO TOMORROW WITH BREEZY AND COOLER
CONDITIONS AND THE BEST CHANCE OF SHOWERS NORTH OF THE MOHAWK
VALLEY AND CAPITAL REGION.
A COLD FRONT CONTINUES TO MAKE STEADY PROGRESS ACROSS NRN-CNTRL NY
EARLY THIS AFTERNOON. VARIABLE MID AND HIGH CLOUDINESS CONTINUES
TO BE MOVING INTO THE TERMINALS AHEAD OF THE COLD FRONT...AND DUE
TO A WEAK SFC WAVE THAT MOVED CLOSE TO THE NEW ENGLAND COASTLINE
THIS MORNING.
THE BEST CHC OF SHOWERS AND ISOLD THUNDERSTORMS WILL BE BETWEEN
20Z-23Z FOR KALB/KPSF/KGFL. CONFIDENCE WAS NOT GREAT ENOUGH FOR
PLACING A THUNDERSTORM IN THE FCST AT THIS POINT DUE TO THE
LIMITED INSTABILITY IN PLACE. A TEMPO GROUP WAS USED FOR MVFR
VSBYS/CIGS WITH THE SHOWERS. THE BEST CHC OF A THUNDERSTORM WILL
BE NEAR KPOU WHERE THERE IS A BIT MORE INSTABILITY...AND THE COLD
FRONT AND SFC TROUGH NEED TO CLEAR THE REGION. A BRIEF TEMPO GROUP
FROM 22Z/TUE TO 00Z/WED WAS PLACED IN THE KPOU TAF.
THE SKIES SHOULD QUICKLY CLEAR IN THE WAKE OF THE FRONT BTWN
23Z/TUE TO 02Z/WED DUE TO THE STRONG SUBSIDENCE.
VFR CONDITIONS SHOULD BE PREVAIL MOST OF THE NIGHT...EXCEPT AT
KGFL/KPSF WHERE SOME PATCHY MIST MAY FORM. FOR NOW...SOME MVFR
VSBYS WERE PLACED IN BTWN 08Z-13Z/WED...BUT IF THE LOW-LEVEL SFC
WINDS STAY UP...THEN MIST/FOG IS NOT LIKELY. LATER TAFS WILL
ADDRESS IFR/LIFR FOG POSSIBILITIES IF CONFIDENCE IS GREATER.
THE WINDS WILL BE FROM THE S/SW TO WEST AT 7-12 KTS AHEAD OF THE
FRONT...AND THEN VEER TO THE W/NW AT 8-12 KTS BTWN 20Z/TUE-
00Z/WED BEHIND THE COLD FRONT. THE WINDS WILL LIGHTEN TO 7 KTS OR
LESS AFTER MIDNIGHT. EXPECT W TO NW WINDS AT 5-10 KTS LATE
TOMORROW MORNING INTO THE AFTERNOON.
OUTLOOK...
WEDNESDAY NIGHT TO SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
&&
.FIRE WEATHER...
A STRONG COLD FRONT WILL CROSS THE REGION TODAY...BRINGING A
CHANCE FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD
FROM CENTRAL CANADA INTO THE UPPER GREAT PLAINS WEDNESDAY...AND
DRIFT INTO THE GREAT LAKES AND OHIO VALLEY BY WEEKS END. IT WILL
USHER IN A COOLER AND LESS HUMID AIR MASS INTO THE REGION FOR THE
REST OF THE WEEK. AT THE SAME TIME A LARGE WEATHER DISTURBANCE
ALOFT WILL DROP FROM QUEBEC INTO THE MARITIMES WEDNESDAY INTO
FRIDAY...WITH INCREASING CLOUDS AND SHOWERS...MAINLY NORTH OF I90.
RELATIVE HUMIDITY VALUES WILL INCREASE TO MAXIMUM VALUES OF 80 TO
100 PERCENT TONIGHT AND WEDNESDAY NIGHT. MINIMUM VALUES THIS
AFTERNOON WILL BE 35 TO 65 PERCENT...AND 35 TO 55 PERCENT
WEDNESDAY AFTERNOON.
WINDS WILL BECOME SOUTHWEST AND INCREASE TO AROUND 10 TO 15 MPH
TODAY. TONIGHT THEY WILL BECOME WEST AROUND 5 MPH AND INCREASE TO
10 TO 15 MPH WEDNESDAY.
&&
.HYDROLOGY...
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY ASSOCIATED
WITH THE PASSAGE OF A COLD FRONT. LOCALLY HEAVY RAINFALL IS
POSSIBLE IN ANY STRONGER STORMS...WITH PONDING OF WATER IN URBAN
AND POOR DRAINAGE LOCATIONS.
MAINLY DRY WEATHER IS THEN EXPECTED FROM WEDNESDAY THROUGH FRIDAY
EXCEPT FOR A FEW LIGHT SHOWERS ACROSS PORTIONS OF THE ADIRONDACKS
AND HIGHER TERRAIN OF VERMONT EACH DAY.
SCATTERED SHOWERS AND THUNDERSTORMS WILL RETURN TO THE REGION
SUNDAY INTO MONDAY WITH LOCALLY HEAVY DOWNPOURS POSSIBLE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...OKEEFE/11/JPV
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...WASULA
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER/JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
1243 PM EDT TUE JUL 21 2015
.SYNOPSIS...
A STRONG COLD FRONT WILL CROSS THE REGION THIS AFTERNOON...BRINGING
A CHANCE FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD
FROM CENTRAL CANADA INTO THE UPPER GREAT PLAINS WEDNESDAY...AND
DRIFT INTO THE GREAT LAKES AND OHIO VALLEY BY WEEKS END. IT WILL
USHER IN A COOLER AND LESS HUMID AIR MASS INTO THE REGION FOR THE
REST OF THE WEEK. AT THE SAME TIME A LARGE WEATHER DISTURBANCE
ALOFT WILL DROP FROM QUEBEC INTO THE MARITIMES WEDNESDAY INTO
FRIDAY...WITH INCREASING CLOUDS AND SHOWERS...MAINLY NORTH OF I90.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM EDT...A STATIONARY BOUNDARY WAS DRAPED ACROSS LONG
ISLAND WITH A WAVE OF LOW PRESSURE OVER CAPE COD. THIS HAS
RESULTED IN CLOUD COVER ACROSS THE FAR SE PTN OF THE FA. MEANWHILE
A STRONG COLD FRONT WAS MOVING SOUTHEAST FROM FAR NRN AND CNTRL NY.
THE MAIN FOCUS FOR THIS AFT INTO ERLY THIS EVENG CONTS TO BE THE
CHANCES FOR SHOWERS AND THUNDERSTORMS AHEAD OF THE COLD FRONT.
THE HRRR COL MAX REFLECTIVITY HAS THE CURRENT LINE OF SHOWERS AND
EMBEDDED THUNDERSTORMS ANALYZED WELL. PRECIP HAS ALREADY ARRIVED
ACROSS FAR NW PTN OF THE FA AND REACHES THE GREATER CAPITAL
DISTRICT BTWN 3 AND 4 PM. AT THAT TIME FRONT WEAKENS SOMEWHAT AND
PRECIPITATION BECOMES MORE DIFFUSE. MEANWHILE...SOME INDICATIONS
OF STRONGER TSRA DEVELOPING ALONG OCCLUDED FRONT/TROUGH ACROSS
SOUTHERN CWA TOWARD THIS TIME. HAVE ATTEMPTED TO TIME THE PRECIP
INTO AND THROUGH THE CWA IN THE GRIDS /WITH LIKELY POPS/ RELYING
ON HRRR.
AS FAR AS SEVERE CHANCES GO...SPC HAS A MARGINAL RISK FOR
SEVERE THUNDERSTORMS ACRS OUR CWA. THIS STILL LOOKS APPROPRIATE.
FAIRLY ANEMIC THERMODYNAMIC PARAMETERS ON 12Z ALY SOUNDING.
HOWEVER...BUF SOUNDING SHOWING BETTER INSTABILITY. 0-6KM SHEAR
RESPECTABLE AT ALY WITH 38 KNOTS NOTED. WEAKER AT BUF. MID LEVEL
LAPSE RATES NOT PARTICULARLY IMPRESSIVE EITHER. VIS SATELLITE
REVEALS QUITE A BIT OF SUNSHINE NOW ACROSS MARGINAL RISK AREA. WE
WILL BE KEEPING A CLOSE EYE ON MESOSCALE ANALYSIS AND THE RADAR
THIS AFTERNOON.
TEMPERATURES WILL STILL BE VERY WARM AHEAD OF THE FRONT...WITH
MID TO UPPER 80S EXPECTED FROM THE HUDSON VALLEY EASTWARD. AREAS
NEAR POUGHKEEPSIE WILL LIKELY REACH 90 DEGREES FOR THE THIRD
CONSECUTIVE DAY.
SHOWERS AND STORMS WILL LIKELY DECREASE IN COVERAGE AFTER DARK DUE
TO LOSS OF DAYTIME HEATING AND INSTABILITY...ALTHOUGH THE COLD FRONT
WILL STILL BE MOVING THROUGH AREAS SOUTH AND EAST OF ALBANY...SO
WILL MAINTAIN SLIGHT TO LOW CHANCE POPS INTO THE EVENING. ANY
SHOWERS WILL DISSIPATE BY MIDNIGHT...WITH DRY CONDITIONS THROUGH THE
REST OF THE OVERNIGHT HOURS AS NORTHWEST FLOW DEVELOPS BEHIND THE
COLD FRONT. TEMPS BY EARLY WEDNESDAY MORNING WILL BE COOLER THAN
RECENT NIGHTS WITH GENERALLY 50S TO LOWER 60S ACROSS THE REGION.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY NIGHT/...
GENERALLY AGREEMENT AMONG THE MDL SUITE THROUGH THIS PERIOD AS WX
PATTERN OVER E NA WILL BE DOMINATED BY A 500 HPA TROF CUT OFF OVER
QB...THAT DIVES SE INTO THE MARITIMES BY FRI. INITIALLY SFC HIGH
PRESSURE BUILDS FM CENTRAL CANADA INTO THE UPPER GRT PLAINS
WED...AS TUES SFC LOW AND CDFNT DEPART OFFSHORE.
BY WED AFTN COOLING ALOFT AS 500HPA TEMPS FALL TO -13C TO -16C AND
JETS MOVING AROUND BASE OF 500HPA CUT OFF SAGGING SOUTH INTO FCA
BEGIN TO IMPACT RGN WITH VARYING DEGREES OF CLOUDS AND SCT MAINLY
DIURNALLY DRIVEN -SHRA N TIER AND OVER HIR TRRN. WOULDN`T RULE
OUT SOME GRAUPAL IN THESE -SHRA OVER HIR TRRN. THE NAM IS MORE
AGGRESSIVE WITH THIS PATTERN INTO THE FCA BY WED AFTN...THE GFS
HOLDING OFF TILL THU. BUT THE TREND IS STILL THE SAME.
AT THE SAME TIME IN RESPONSE TO THE DIVING 500 HPA TROF...SFC LOW
PRESSURE OVER MARITIMES DEEPENS...AND WIND GRADIENT INCRG OVR RGN
ESPECIALLY IN THE AFTN...RESULTING IN BREEZY CONDS AT TIMES.
SO OVERALL A PERIOD OF PC TO AT TIMES MC SKIES N WITH SCT SHRA
EACH DAY...DIURNALLY DRIVEN. GENERALLY MS SOUTH OF I90. TEMPS WILL
BE 3-5 DEG BLO NORMALS...WITH VERY COMFORTABLE RH LEVELS AS TD
FALL TO THE UPPER 40S AND 50S. FRIDAY NIGHT 500 HPA TROF FINALLY
SLIDES OFFSHORE AS SFC HIGH SETTLES OVER NE USA INTO QB.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
ECMWF/GFS/HPC PRETTY MUCH IN AGREEMENT.
SATURDAY BRINGS A 500 HPA RIDGE INTO THE REGION AS SFC HIGH
SLIDES OFFSHORE. FOR THE MOST PART IT SHOULD BE A DRY DAY WITH
TEMPS NR TO SLIGHTLY BLO NORMAL.
AFT SAT THE REST OF THE EFP WILL BE AN UNSETTLED PERIOD. AS THE
500HPA RIDGE MOVES EAST OF RGN SAT NIGHT CLOUDS INCR. AT THE SFC
A WMFNT PUSHES TO ABOUT CLE- ORF...AND RESULT IS INCG CHC
SHRA/TSTMS SAT NT...AND A THREAT OF SHRA/TSTMS INTO MON.
BY SUN MRNG THE 500HPA RIDGE IS OFFSHORE...AND THE 500HPA FLOW
HAS BCM NW. THIS LEAVES THE SFC HIGH OFFSHORE...WEAK WAA OVER
FCA...AND THE WMFNT ONLY MVNG SLIGHTLY NE THROUGH MON. COMBINATION
OF CONVECTIVE DEBRIS...AND SOME MID LEVEL DRYING WILL RESULT IN
VRBL CLOUDS AND MAYBE SOME SUNNY PERIODS SUN AND MON. DIURNALLY
DRIVEN ROUNDS OF -SHRA/TSTMS WILL AGAIN BE POSSIBLE SUN AND AGAIN
MON.
TEMPS WILL REMAIN NR TO SLIGHTLY BLO NORMALS...BUT TD WILL CREEP
SLOWLY UP THROUGH THE 50S AND RETURN TO THE 60S BY MON. WILL
POPULATE WITH HPC GUID.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
SCT-BKN MID AND HIGH LEVEL CLOUDS ACROSS THE REGION THIS MORNING
WITH PREVAILING VFR CONDITIONS. A COLD FRONT APPROACHING FROM THE
GREAT LAKES WILL MOVE INTO THE REGION LATE IN THE DAY...TRIGGERING
MAINLY SCATTERED SHRA/TSRA. WILL MENTION PROB30 FOR TSRA FROM LATE
AFTERNOON INTO EARLY EVENING AT KALB/KGFL/KPSF BUT ONLY VCSH AT
KPOU SINCE COVERAGE SHOULD BE ONLY ISOLATED THERE. BRIEF MVFR OR
IFR WILL BE POSSIBLE WITHIN ANY SHRA/TSRA.
WINDS WILL INITIALLY BE LIGHT AND VARIABLE...BECOMING SOUTH TO
SOUTHWEST AROUND 5-10 KTS DURING THE DAY. WINDS WILL SHIFT TO THE
NORTHWEST BEHIND THE COLD FRONT THIS EVENING.
OUTLOOK...
WEDNESDAY NIGHT TO SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
&&
.FIRE WEATHER...
A STRONG COLD FRONT WILL CROSS THE REGION TODAY...BRINGING A
CHANCE FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD
FROM CENTRAL CANADA INTO THE UPPER GREAT PLAINS WEDNESDAY...AND
DRIFT INTO THE GREAT LAKES AND OHIO VALLEY BY WEEKS END. IT WILL
USHER IN A COOLER AND LESS HUMID AIR MASS INTO THE REGION FOR THE
REST OF THE WEEK. AT THE SAME TIME A LARGE WEATHER DISTURBANCE
ALOFT WILL DROP FROM QUEBEC INTO THE MARITIMES WEDNESDAY INTO
FRIDAY...WITH INCREASING CLOUDS AND SHOWERS...MAINLY NORTH OF I90.
RELATIVE HUMIDITY VALUES WILL INCREASE TO MAXIMUM VALUES OF 80 TO
100 PERCENT TONIGHT AND WEDNESDAY NIGHT. MINIMUM VALUES THIS
AFTERNOON WILL BE 35 TO 65 PERCENT...AND 35 TO 55 PERCENT
WEDNESDAY AFTERNOON.
WINDS WILL BECOME SOUTHWEST AND INCREASE TO AROUND 10 TO 15 MPH
TODAY. TONIGHT THEY WILL BECOME WEST AROUND 5 MPH AND INCREASE TO
10 TO 15 MPH WEDNESDAY.
&&
.HYDROLOGY...
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY ASSOCIATED
WITH THE PASSAGE OF A COLD FRONT. LOCALLY HEAVY RAINFALL IS
POSSIBLE IN ANY STRONGER STORMS...WITH PONDING OF WATER IN URBAN
AND POOR DRAINAGE LOCATIONS.
MAINLY DRY WEATHER IS THEN EXPECTED FROM WEDNESDAY THROUGH FRIDAY
EXCEPT FOR A FEW LIGHT SHOWERS ACROSS PORTIONS OF THE ADIRONDACKS
AND HIGHER TERRAIN OF VERMONT EACH DAY.
SCATTERED SHOWERS AND THUNDERSTORMS WILL RETURN TO THE REGION
SUNDAY INTO MONDAY WITH LOCALLY HEAVY DOWNPOURS POSSIBLE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...OKEEFE/11/JPV
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...JPV
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER/JPV
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
356 PM EDT TUE JUL 21 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS OUR AREA TONIGHT, THEN HIGH PRESSURE
BUILDS IN DURING WEDNESDAY. THIS HIGH PRESSURE SYSTEM IS FORECAST TO
REMAIN IN PLACE THROUGH FRIDAY. HOWEVER, A WEAK COLD FRONT ARRIVES
FROM THE NORTH FRIDAY THEN RETURNS NORTHWARD AS A WARM FRONT LATE
SATURDAY. A POTENTIALLY WEAKENING COLD FRONT IS THEN FORECAST TO
MOVE THROUGH OUR REGION LATE SUNDAY INTO MONDAY AS HIGH PRESSURE
RETURNS FOR TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
A LATE-DAY SURFACE ANALYSIS SHOWS A WEAK SURFACE TROUGH EXTENDING
ACROSS SOUTHERN PORTIONS OF THE FORECAST AREA, FROM SOUTHERN NJ AND
INTO THE DELMARVA. THIS BOUNDARY IS PROVIDING A FOCUS FOR SCATTERED
SHWR/TSTORM ACTIVITY, AND WE HAVE INCREASED POPS ACCORDINGLY TO HIGH
CHANCE AND LOW LIKELY FOR THESE AREAS. ANY SHWRS/TSTORMS WILL HAVE
THE POTENTIAL TO PRODUCE TORRENTIAL DOWNPOURS AS THERE IS AMPLE
BOUNDARY LAYER MOISTURE, WITH PWATS REMAINING AROUND 2.0 INCHES AND
SURFACE DEW POINTS HOLDING IN THE LOW 70S. WHILE WIDESPREAD
STRONGER TO SEVERE STORMS ARE NOT EXPECTED, DEVELOPING STORMS IN
THIS ENVIRONMENT COULD BRIEFLY PULSE UP AND PRODUCE STRONG WIND
GUSTS TO THE SURFACE AS THERE IS ADEQUATE INSTABILITY AND SHEAR.
ELSEWHERE, A COLD FRONT WILL CONTINUE TO APPROACH OUR REGION FROM
THE NORTHWEST. AS THIS FRONT EDGES INTO NORTHERN AND WESTERN
PORTIONS OF THE FORECAST AREA INTO THIS EVENING, SOME SCATTERED
SHWRS AND TSTORMS MAY ACCOMPANY IT, ESPECIALLY INTO THE POCONOS, THE
LEHIGH VALLEY, AND NORTHWEST NJ. THE OPPORTUNITY FOR SHWR/TSTORM
ACTIVITY LOOKS TO BE RELATIVELY SHORT-LIVED, THOUGH, AS MOST MODEL
GUIDANCE INCLUDING THE HRRR AND NAM12 TENDS TO SOMEWHAT WEAKEN THE
INCOMING CONVECTION AS IT ENTERS AND MOVES THROUGH OUR NORTHWEST
ZONES. AS MENTIONED ABOVE A FEW BRIEFLY STRONGER STORMS COULD ALSO
PULSE-UP IN THESE AREAS, WITH GUSTY WINDS BEING THE MAIN CONCERN.
THE COLD FRONT IS EXPECTED TO CROSS OUR REGION THROUGH THE LATE
EVENING HOURS AND PASS OFFSHORE AROUND MIDNIGHT. ANY REMAINING
SCATTERED SHWR/TSTORM ACTIVITY WILL QUICKLY TAPER OFF WITH THE
PASSAGE OF THE FRONT, AND IN ITS WAKE, A DRIER AIRMASS WILL BEGIN TO
OVERSPREAD THE REGION THROUGH THE OVERNIGHT. SKIES ARE ALSO EXPECTED
TO CLEAR IN THE WAKE OF THE FRONT WITH A WIND SHIFT TO THE
NORTHWEST. OVERNIGHT MINIMUM TEMPERATURES WILL BE MORE COMFORTABLE
THAN RECENT NIGHTS, AS LOWS RANGE FROM THE UPPER 50S IN THE NORTH TO
MOSTLY THE UPPER 60S ELSEWHERE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
WITH THE PREVIOUSLY MENTIONED COLD FRONT MOVING FARTHER OFFSHORE
THROUGH THE DAYTIME WEDNESDAY, INCOMING HIGH PRESSURE CENTERED OVER
THE GREAT LAKES AND MIDWEST STATES WILL GRADUALLY BE BUILDING
EASTWARD TOWARD OUR REGION. A NOTICEABLY COOLER AND DRIER AIRMASS
WILL CONTINUE TO OVERSPREAD THE REGION ON WEST-NORTHWEST WINDS.
AMPLE SUNSHINE IS ANTICIPATED THROUGH THE DAY, WITH PERHAPS A FEW
AFTERNOON CUMULUS DEVELOPING. IN ADDITION, DEW POINTS WILL BE
DROPPING INTO THE 50S THROUGH THE COURSE OF THE DAY, GIVING THE AREA
RELIEF FROM THE HUMIDITY. A BLEND OF MET/MAV GUIDANCE PUTS AFTERNOON
HIGH TEMPERATURES MAINLY INTO THE 80S ACROSS THE REGION, WITH
PERHAPS THE HIGHER TERRAIN IN THE POCONOS ONLY REACHING THE MID TO
UPPER 70S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF A STRONG UPPER-LEVEL TROUGH IN
SOUTHEASTERN CANADA AND THE NORTHEAST WEDNESDAY NIGHT AND THURSDAY,
WHICH THEN SHIFTS EAST SOME INTO FRIDAY. THIS FEATURE SHOULD SHIFT
EAST LATER FRIDAY AS A SHORT WAVE TROUGH DIVES SOUTHEASTWARD FROM
THE MIDWEST. THIS TROUGH SHOULD AMPLIFY THE MAIN UPPER-LEVEL TROUGH
ONCE AGAIN ACROSS THE NORTHEAST OVER THE WEEKEND, WITH SOME
RELAXATION POSSIBLE EARLY NEXT WEEK. THERE ARE SOME HINTS WITHIN THE
GUIDANCE THAT A STRONG RIDGE ACROSS THE PLAINS MAY START TO EXPAND
NORTHEASTWARD NEXT WEEK INTO THE MID ATLANTIC. WE USED A MODEL BLEND
FOR WEDNESDAY NIGHT THROUGH FRIDAY, THEN WENT WITH THE 12Z WPC
GUIDANCE. SOME ADJUSTMENTS WERE THEN MADE FOLLOWING ADDITIONAL
COLLABORATION WITH OUR NEIGHBORING OFFICES.
FOR WEDNESDAY NIGHT...AN UPPER-LEVEL TROUGH IS IN PLACE, HOWEVER
SURFACE HIGH PRESSURE IS FORECAST TO BUILD OVER THE AREA. THIS
SHOULD RESULT IN LESS CLOUDINESS AND A DIMINISHING WIND ALONG WITH
MUCH COOLER TEMPERATURES.
FOR THURSDAY AND FRIDAY...HIGH PRESSURE OVER THE AREA GRADUALLY
WEAKENS DURING THIS TIME FRAME, HOWEVER AN AIRMASS CHARACTERIZED BY
LOW HUMIDITY LEVELS IS ANTICIPATED TO REMAIN FOR MUCH OF THE AREA.
AN UPPER-LEVEL TROUGH IS FORECAST TO AMPLIFY ACROSS THE NORTHEAST AS
SHORT WAVE ENERGY DIGS INTO ITS BASE. THIS IS MOST NOTED ACROSS NEW
ENGLAND WHERE THE COLD POOL ALOFT IS MORE PRONOUNCED. THE COOLING
ALOFT MAY ALLOW FOR A BIT MORE CLOUDINESS ACROSS OUR NORTHERN AREAS
ESPECIALLY ON FRIDAY, HOWEVER IT APPEARS THAT ANY SHOWER CHC IS
RATHER LOW. A SOUTHERN TRACKING SHORT WAVE THOUGH MAY ALLOW FOR A
WEAK SURFACE LOW TO DEVELOP ALONG A FRONTAL BOUNDARY TO OUR SOUTH.
GIVEN THE ORIENTATION OF THE UPPER-LEVEL TROUGH AND A SEPARATE
BOUNDARY ARRIVING FROM THE NORTH, THIS FEATURE SHOULD REMAIN FAR
ENOUGH TO OUR SOUTH. AS A RESULT, WE CONTINUED WITH A DRY FORECAST.
FOR SATURDAY AND SUNDAY...SOME UPPER-LEVEL RIDGING SHOULD MOVE
ACROSS THE AREA ON SATURDAY AND A WARM FRONT MAY LIFT NORTH AS A
RESULT. LOW PRESSURE IS FORECAST TO TRACK WELL TO OUR NORTH LATE
SATURDAY AND SUNDAY, WITH AN ASSOCIATED COLD FRONT MOVING OUR WAY
LATE SUNDAY. THE FRONT ITSELF MAY BEGIN TO WEAKEN, HOWEVER A
POSSIBLE PRE-FRONTAL TROUGH MAY HELP FOCUS SOME CONVECTION AS WAA
OCCURS IN CONJUCTION WITH SOME MOISTURE RETURN. THE MAIN PORTION OF
THE UPPER-LEVEL TROUGH IS FORECAST TO TRACK FARTHER NORTH, THEREFORE
MUCH OF THE LIFT FOR ORGANIZED CONVECTION COULD BE FARTHER NORTH AS
WELL. WE FAVORED WPC GUIDANCE WHICH CARRIES CHC POPS ON SUNDAY
ESPECIALLY IN THE AFTERNOON AND EVENING.
FOR MONDAY AND TUESDAY...A FRONTAL BOUNDARY OR LINGERING SURFACE
TROUGH IN OUR VICINITY MIGHT BE ABLE TO FORCE SOME CONVECTION
MONDAY, AS OUR AREA REMAINS INFLUENCED BY AN UPPER-LEVEL TROUGH
MIGRATING ACROSS THE NORTHEAST. THE UPPER-LEVEL TROUGH REMAINS ON
TUESDAY, ALTHOUGH WEAK SURFACE HIGH PRESSURE IS CURRENTLY FORECAST
TO BE NEARBY. FOR NOW, WE INCLUDED A SLIGHT CHC POP IN THE GRIDDED
DATABASE/FORECAST.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
LATE-DAY AND THIS EVENING...MOSTLY VFR CONDITIONS ARE EXPECTED FOR
THE TAF SITES OUTSIDE OF ANY ISOLATED TO SCATTERED SHWRS/TSTORMS
WHICH COULD TEMPORARILY REDUCE CONDITIONS, ESPECIALLY VSBYS, TO MVFR
OR POSSIBLE IFR. REGARDING THE WINDS, WESTERLY WINDS AVERAGING 5 TO
8 KNOTS AT LATE-DAY WILL BECOME NORTHWESTERLY AT 10 KNOTS OR LESS
BETWEEN THE 02Z TO 04Z TIMEFRAME FOLLOWING THE PASSAGE OF A COLD
FRONT THROUGH THE AREA.
OVERNIGHT...VFR CONDITIONS ARE EXPECTED WITH SKIES CLEARING THROUGH
THE OVERNIGHT. NORTHWEST WINDS AVERAGING 5 TO 10 KNOTS WILL CONTINUE.
WEDNESDAY...VFR CONDITIONS WITH PERHAPS SOME MIDDAY TO AFTERNOON
CUMULUS DEVELOPING WITH BASES 5,000 FEET. NORTHWEST WINDS CONTINUE,
WITH SOME GUSTS BETWEEN 15 TO 20 KNOTS POSSIBLE INTO THE
AFTERNOON.
OUTLOOK...
WEDNESDAY NIGHT...VFR WITH NORTHWEST WINDS DIMINISHING TO 5 KNOTS OR
LESS.
THURSDAY AND FRIDAY...VFR. WEST-NORTHWEST WINDS NEAR 10 KNOTS,
ALTHOUGH LIGHTER EACH NIGHT.
SATURDAY AND SUNDAY...VFR OVERALL, WITH SOME INCREASE IN CLOUDS
ESPECIALLY SUNDAY. SOME SHOWERS AND THUNDERSTORMS ARE POSSIBLE
SUNDAY ESPECIALLY IN THE AFTERNOON.
&&
.MARINE...
SUB-ADVISORY CONDITIONS ARE EXPECTED ON THE AREA WATERS TONIGHT AND
THROUGH THE DAYTIME WEDNESDAY. HOWEVER, SOME SCATTERED SHWRS/TSTORMS
ARE POSSIBLE THROUGH TONIGHT ASSOCIATED WITH A COLD FRONT,
ESPECIALLY FOR THE SOUTHERN COASTAL WATERS, YIELDING POSSIBLE BRIEF
HIGHER WINDS AND/OR SEAS. FOLLOWING THE COLD FRONT PASSAGE AROUND
MIDNIGHT OR SO ACROSS THE WATERS, A WIND SHIFT TO THE NORTHWEST IS
ANTICIPATED. DURING THE DAYTIME WEDNESDAY THE WEST-NORTHWEST WINDS
COULD GUST AROUND 20 KNOTS AT TIMES, ESPECIALLY FOR THE COASTAL
WATERS.
OUTLOOK...
WEDNESDAY NIGHT AND THURSDAY...THE CONDITIONS ARE EXPECTED TO BE
BELOW SMALL CRAFT ADVISORY CRITERIA AS HIGH PRESSURE BUILDS IN. THIS
WILL RESULT IN SOME DECREASE IN THE WINDS.
FRIDAY THROUGH SUNDAY...A WEAK FRONT ARRIVES FROM THE NORTH FRIDAY
HOWEVER IT THEN LOOKS TO LIFT BACK NORTH AS A WARM FRONT LATER
SATURDAY. A SOUTHERLY WIND SHOULD INCREASE SUNDAY AHEAD OF A COLD
FRONT, HOWEVER THE CONDITIONS OVERALL SHOULD REMAIN BELOW SMALL
CRAFT ADVISORY CRITERIA.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...KLINE
SHORT TERM...KLINE
LONG TERM...GORSE
AVIATION...GORSE/KLINE
MARINE...GORSE/KLINE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1240 PM CDT TUE JUL 21 2015
.UPDATE...
ISSUED AT 1028 AM CDT TUE JUL 21 2015
HIGH PRESSURE BUILDING INTO THE MIDWEST BEHIND A COLD FRONT THAT
PASSED THROUGH CENTRAL IL OVERNIGHT WILL BRING COOLER AND DRIER
CONDITIONS TODAY...ALONG WITH LIGHT NORTHERLY BREEZES TO AROUND 10
MPH. SKIES WILL BE MOSTLY CLEAR...ALTHOUGH SOME SCATTERED
AFTERNOON CLOUD COVER WILL DEVELOP. AN INVERSION AROUND 5000 FEET
AGL WILL LIMIT VERTICAL DEVELOPMENT OF CLOUDS...SO NO
PRECIPITATION EXPECTED. HIGHS STILL LOOK ON TRACK TO REACH AROUND
80 MOST AREAS...TO AROUND 84 IN SOUTHEASTERN PORTIONS OF THE
FORECAST AREA. DEWPOINTS IN THE 60S TO AROUND 70 THIS MORNING
SHOULD DECREASE TO AROUND 60-65 BY AFTERNOON WITH ADVECTION OF
DRIER AIR FROM THE NORTH. NO UPDATES NEEDED THIS MORNING OTHER
THAN MINOR ADJUSTMENTS TO HOURLY TEMP/DEWPOINT/WIND TRENDS.
&&
.SHORT TERM...(TODAY)
ISSUED AT 318 AM CDT TUE JUL 21 2015
FRONTAL BOUNDARY LYING ACROSS SOUTHEAST ILLINOIS THIS MORNING WITH
MOST OF THE DEEP CONVECTION SOUTH OF THIS FEATURE WITH A SECONDARY
BOUNDARY NOTED ON THE LATEST SURFACE ANALYSIS EXTENDING ACROSS THE
ILLINOIS RIVER VALLEY. SOME BROKEN CLOUDS ASSOCIATED WITH THE
SECONDARY BOUNDARY BUT HAVE NOT SEEN ANY PRECIP ASSOCIATED WITH THE
BAND OF CLOUDS. SOME PATCHY FOG HAS DEVELOPED OVER PARTS OF EAST
CENTRAL ILLINOIS OVER THE PAST SEVERAL HOURS AND WILL SEE THAT
GRADUALLY SHIFT INTO SOUTH CENTRAL THROUGH SOUTHEAST ILLINOIS EARLY
THIS MORNING AS DRIER AIR ADVECTS SOUTHEAST INTO THE FORECAST AREA.
OUR WEATHER TODAY WILL FEATURE PLEASANTLY WARM TEMPERATURES AND
LOWER HUMIDITY LEVELS AS HIGH PRESSURE SETTLES IN FROM THE NORTHWEST
THIS AFTERNOON. FORECAST SOUNDINGS OFF THE GFS SUGGEST WE SHOULD MIX
DOWN FROM ABOUT 850 MB THIS AFTERNOON WHICH WOULD GIVE US HIGHS IN
THE 80 TO 84 DEGREE RANGE, WHILE THE RAP SOUNDINGS WERE MUCH MORE
AGGRESSIVE WITH MIXING HEIGHTS YIELDING HIGHS IN THE MID TO EVEN
UPPER 80S IN OUR SOUTHEAST COUNTIES. THINK THE CURRENT RAP MAY BE
UNDERPLAYING THE COOL ADVECTION FILTERING IN FROM THE NORTHWEST SO
WILL SIDE WITH THE MORE CONSERVATIVE GFS SOLUTION AND TEMPERATURES
FOR THIS AFTERNOON.
.LONG TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 318 AM CDT TUE JUL 21 2015
HIGH PRESSURE BUILDING BACK INTO THE REGION FOR THE SHORT TERM
BRINGING A DRIER FORECAST AND A LESS MUGGY AIRMASS. TEMPS JUST
BELOW NORMAL FOR THE NEXT TWO DAYS BEHIND TODAYS COLD FRONT. WIDE
UPPER RIDGE OVER THE SOUTHERN THIRD OF THE CONUS STARTING TO AMPLIFY
A BIT TOWARDS THE END OF THE WEEK. MIDWEST GETTING INTO THE RIDGE
WITH LITTLE FLOW ALOFT AS A QUICK IMPULSE RIPPLES OVER THE RIDGE AND
DIVES INTO THE MID MISS RIVER VALLEY WED NIGHT AND INTO THURSDAY.
FOR NOW, THE FORECAST IS DRY, BUT THE NAM IS SHOWING SIGNS OF A
SLIGHTLY DIFFERENT TRACK JUST TO THE NE AND INTO ILX/S SW. SLIGHTS
WILL REMAIN IN THE FORECAST FOR THU/THU NIGHT.
AS THE UPPER RIDGE BUILDS ACROSS THE MIDDLE OF THE CONUS WITH THE
AXIS DRIFTING OVER THE MIDWEST, A WARMING TREND RETURNS FOR THE END
OF THE WEEK AND INTO THE WEEKEND. POOL OF HEAT OVER THE DESERT SW
SLOWLY ENCROACHING ON THE MIDWEST WITH 850MB TEMPS REACHING 20-23C
BY SATURDAY AFTERNOON AS THE RIDGE AMPLIFIES. MIXED DOWN, TEMPS AT
THE SFC SET TO MAX INTO THE MID TO UPPER 80S, SLIGHTLY ABOVE
CLIMATOLOGY, AS WELL AS SLIGHTLY ABOVE THE MAJORITY OF THE
GUIDANCE...AND HAVE ADJUSTED THE FORECAST IN THAT DIRECTION.
CONCERNED ABOUT THE FORECAST THROUGH THE WEEKEND WITH REGARDS TO THE
PRECIPITATION. UNDER THE EXPANSIVE RIDGE, MODELS ARE NOT HANDLING
SMALL IMPULSES WITH ANY KIND OF CONTINUITY OR CONSENSUS. SLIGHTS
AND LOW CHANCE POPS DOMINATE THE SUPERBLEND AS A RESULT THROUGH THE
WEEKEND AND INTO THE FIRST PART OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1240 PM CDT TUE JUL 21 2015
VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HOURS...WITH SCATTERED
CLOUD COVER AT 3.5 TO 4 KFT AGL THROUGH THE LATE AFTERNOON HOURS.
ISOLD MVFR CIGS POSSIBLE WITH LOCALLY LOWERED CEILINGS...BUT
COVERAGE TOO MINIMAL FOR MENTION IN 18Z TAFS. CLOUD COVER
DISSIPATING AROUND SUNSET...AND RETURNING LATE MORNING WEDNESDAY.
WINDS NNE 8-10 KTS DIMINISHING AFTER 00Z. WINDS BECOMING SE 4-8
KTS WEDNESDAY MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ONTON
SHORT TERM...SMITH
LONG TERM...HJS
AVIATION...ONTON
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
100 PM EDT TUE JUL 21 2015
.SYNOPSIS...
ISSUED AT 648 AM EDT TUE JUL 21 2015
HIGH PRESSURE WILL MOVE INTO THE GREAT LAKES AND OHIO VALLEY
REGION TODAY BRINGING COOLER TEMPERATURES AND LESS HUMID AIR. IT
WILL BE MOSTLY SUNNY TODAY WITH HIGHS IN THE MIDDLE TO UPPER 70S.
WITH MOSTLY CLEAR SKIES AND LIGHT WINDS TONIGHT...LOW TEMPERATURES
WILL FALL INTO THE 50S.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 421 AM EDT TUE JUL 21 2015
SHORT WAVE MOVING ACROSS THE GREAT LAKES THIS MORNING WITH
ASSOCIATED COLD FRONT SLOWLY WORKING SOUTH ACROSS OUR LOCAL AREA.
A FEW ISOLATED SHOWERS HAD POPPED ALONG FRONT ACROSS NORTHERN
COUNTIES EARLY THIS MORNING. HIRES HRRR AND RAP GUIDANCE HAD THIS
HANDLED AND INDICATE AN ISOLATED SHRA REMAINS POSSIBLE THROUGH
DAYBREAK IN THE NORTH AND NORTHEAST NEAR FRONT. A FEW OF THE HRRR
RUNS TRIES TO DEVELOP WEAK SHOWERS ALONG FRONT IN THE SOUTHEAST
LATER THIS MORNING. RECENT RADAR RETURNS HAVE BEGUN TO WEAKEN AND
EXPECT MOST ACTIVITY WILL DIMINISH OR REMAIN VERY ISOLATED. WILL
CARRY AN ISOLATED SHRA THROUGH 12Z DOWNSTREAM FROM CURRENT RADAR
RETURNS BUT MOST AREAS WILL REMAIN DRY.
ONCE COLD FRONT EXITS THE AREA HIGH PRESSURE WILL BUILD IN WITH
SKIES BECOMING MOSTLY SUNNY. COOLER AND LESS HUMID AIR WILL FOLLOW
TODAY. HIGHS IN THE 70S WITH COMFORTABLE HUMIDITY LEVELS. WITH HIGH
OVER THE REGION TONIGHT SKIES WILL BE CLEAR AND WINDS LIGHT. THIS
WILL ALLOW MIN TEMPS TO DROP INTO THE 50S.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 421 AM EDT TUE JUL 21 2015
A TRANQUIL PATTERN WILL PERSIST THROUGH FRIDAY AS AN UPPER LEVEL
RIDGE GRADUALLY BUILDS NORTH OF THE OHIO RIVER. KEPT THE FORECAST
DRY THROUGH FRIDAY NIGHT GIVEN A SEASONALLY DRY
SOUNDING...SOMEWHAT OF A LOW LEVEL CAP...LARGE SCALE SUBSIDENCE
AND STABLE MID LEVEL LAPSE...GENERALLY 4.0 TO 6.5 C/KM. KEPT THE
GENERAL ONGOING TIMING FOR STORMS THIS WEEKEND AS SOME SHORT WAVE
ENERGY FROM AN UPPER LEVEL TROF WILL BE ABLE TO TOP THE RIDGE AND
DESCEND INTO THE WESTERN/UPPER GREAT LAKES REGION. BOTH THE GFS
AND THE ECMWF ARE IN AGREEMENT WITH THE TIMING OF THIS SYSTEM.
THESE MODELS ALSO EXPAND THE UPPER LEVEL RIDGE FARTHER NORTHEAST
WITH 500 HEIGHTS BUILDING ABOVE 590 DEKAMETERS NEAR THE END OF THE
PERIOD. OTHERWISE...HIGHS SHOULD BE FROM AROUND 80 TO THE MID 80S
WITH LOWS AROUND 60 RISING INTO THE MID 60S AS THE UPPER LEVEL
RIDGE BUILDS NORTHEAST EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 100 PM EDT TUE JUL 21 2015
VFR CONDITIONS EXPECTED THIS TAF CYCLE. SCT DIURNAL CU OVER THE AREA
WILL QUICKLY DISSIPATE TOWARD SUNSET. N/NW WINDS 10-15KTS WILL ALSO
DIMINISH THIS EVENING AND REMAIN LIGHT AND VARIABLE INTO WEDNESDAY
AS HIGH PRESSURE CENTER WILL MOVE OVER THE AREA.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...LOGSDON
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
623 PM EDT TUE JUL 21 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TONIGHT. AN UPPER LEVEL TROUGH
WILL SWING ACROSS THE REGION ON WEDNESDAY WITH ANOTHER FRONTAL
BOUNDARY FOR THURSDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
623 PM UPDATE...A LINE OF SHOWERS AND THUNDERSTORMS AHEAD OF A
COLD FRONT WILL SWEEP EAST ACROSS NORTHERN MAINE THIS EVENING. THE
MAIN THREATS ARE DANGEROUS CLOUD TO GROUND LIGHTNING AND
TORRENTIAL DOWNPOURS OF RAIN. THE KCBW 88-D INDICATED RAINFALL
AMOUNTS IN EXCESS OF 4 INCHES IN A SMALL AREA WEST OF ALLAGASH.
THE ESTCOURT STATION GAGE REPORTED 0.73" FROM 5-6 PM AND THIS WAS
NOT FAR FROM THE LEGACY RADAR ESTIMATES. THE DUAL POL ACTUALLY
UNDERESTIMATED THE RAINFALL AMOUNTS. SUSPECT THERE IS AT LEAST
SOME HAIL CONTAMINATION...BUT IN ANY EVENT AN INCH OR TWO OF RAIN
IS POSSIBLE IN AN HOUR UNDER THE HEAVIEST OF THE THUNDERSTORMS.
THE GOOD NEWS...THE STORMS ARE NOT EXPECTED TO PRODUCE LARGE HAIL
OR DAMAGING WIND. AS THE ACTIVITY MOVES EAST IT IS MOVING INTO A
MUCH MORE STABLE ENVIORNMENT AND THE ACTIVITY SHOULD WEAKEN THIS
EVENING. ONLY MINOR UPDATES BASED ON THE LATEST RADAR TRENDS.
PREVIOUS DISCUSSION...
SCATTERED THUNDERSTORMS EXPECTED INTOTONIGHT W/HEAVY RAINFALL
POTENTIAL AND CLOUD TO GROUND LIGHTNING. SOME STRONGER STORMS
COULD CONTAIN BRIEF WIND GUSTS ESPECIALLY W/THE ARRIVAL OF THE
COLD FRONT LATER THIS EVENING. SPC UPDATED THE DAY1 OUTLOOK W/A
MARIGNAL RISK FOR WESTERN MAINE THROUGH THE EVENING.
THE MAIN ACTION ATTM WAS ACROSS FAR WNW MAINE W/TRAINING CELLS
AND VERY HEAVY RAINFALL PER THE LATEST RADAR LOOP. RADAR
ESTIMATES OF UP TO 2"/HR IN THE STRONGER CELLS. CELLS MOVING ALONG
THE UPPER SW FLOW ALLOWING FOR RE-GENERATION OF THE STORMS AND
THEREFORE HEAVY RAINFALL POTENTIAL. PWATS IN THIS REGION UP AROUND
1.5 INCHES W/GOOD MOISTURE TRANSPORT FROM 925-850MBS PER THE
LATEST MESO- ANALYSIS. THIS ACTIVITY WAS IGNITING ALONG A PRE-
FRONTAL TROF WELL FORECASTED BY THE MIDNIGHT CREW. LOCALIZED
FLOODING POSSIBLE IN THIS AREA. FURTHER E, ATMOSPHERE MORE STABLE
THANKS TO A SSE FLOW AND CLOUD COVER LIMITING HEATING. ACTIVITY TO
THE W IS FORECAST TO BREAK UP AS IT PUSHES E INTO THE EVENING.
ANOTHER ORGANIZED LINE OF CONVECTION IS SHOWN BY MESOSCALE
GUIDANCE INCLUDING THE NAM12 AND HRRR 3KM MODEL TO MOVING ACROSS
THE NORTHERN 1/2 OF THE CWA THIS EVENING INTO EARLY TONIGHT. THIS
ACTION WILL BE IN ASSOCIATION W/THE MAIN COLD FRONT. SOUNDING
PROFILES NOT OVERLY IMPRESSIVE FOR STRONG CONVECTION, BUT MUCAPES
OF 600+ JOULES AND COLUMN MOISTENING UP THROUGH 700MBS LATER THIS
EVENING PLUS INCREASING MID LEVEL SHEAR WILL ALLOW FOR SOME DECENT
SHOWERS/STORMS. AGAIN, HEAVY RAINFALL AND LIGHTNING THE MAIN
THREAT. DECIDED TO GO W/BASIN QPF OF 1.25+ INCHES THROUGH WEST AND
NORTHWEST MAINE THROUGH MIDNIGHT DUE TO THE TRAINING CELLS.
ALL ACTION WILL WEAKEN AND PUSH TO THE ESE LATER TONIGHT W/COOLER
AND DRIER AIR BEHIND THE FRONT BY WEDNESDAY MORNING. DECIDED TO
ADD FOG INTO THE FORECAST TONIGHT BEFORE THE FROPA W/DEEP LLVL
MOISTURE IN PLACE. DOWNEAST AND THE COAST WILL HAVE THE BEST SHOT
AS SEEING THE FOG. UNSETTLED ON WEDNESDAY W/THE UPPER TROF AXIS
FORECAST TO ACROSS THE REGION. BEST MOISTURE AVAILABLE LOOKS TO BE
IN THE LLVLS AROUND 850MBS. SOME INSTABILITY IS THERE BUT MARGINAL
AND LOW/MID LEVEL LAPSE RATES ARE WEAK. THEREFORE, DECIDED TO
LEAN AWAY FROM THE MENTION OF TSTMS AND KEPT JUST SHOWERS ATTM.
LATER CREWS CAN ASSESS THIS FURTHER W/THE LATEST GUIDANCE.
TEMPERATURES WILL CONTINUE TO BE BELOW NORMAL FOR JULY.
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
THE REGION IS EXPECTED TO REMAIN IN A CYCLONIC FLOW ON THE BACK
SIDE OF SURFACE LOW PRESSURE LOCATED TO THE EAST OF NOVA SCOTIA
ALONG WITH AN UPPER LEVEL SYSTEM TO THE NORTHWEST. IN ADDITION THE
UPPER LEVEL SYSTEM IS EXPECTED TO MOVE SOUTHEAST WARD AND CROSS
OVER THE NORTHERN AND EASTERN PORTION OF MAINE FRIDAY. THIS IS
EXPECTED TO RESULT IN SHOWERS... ESPECIALLY IN THE NORTH AND
DURING DAYLIGHT HOURS. WILL BLEND THE GFS AND ECMWF FOR POPS...
QPF AND SKY. FOR MAXIMUM TEMPERATURE WILL USE THE CONSENSUS RAW.
FOR MINIMUM TEMPERATURE HAVE USED THE CONSENSUS ALL. WILL USE THE
MOSG25 FOR WINDS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPPER LOW WILL PULL AWAY FROM NEW ENGLAND FRIDAY NIGHT INTO
SATURDAY, FOLLOWED BY A VERY BRIEF RIDGE OF HIGH PRESSURE. AS
SUCH, THE FIRST PART OF THE WEEKEND WILL HAVE THE LOWEST CHANCES
FOR RAIN, THOUGH A FEW SHOWERS CAN`T BE TOTALLY RULED OUT,
ESPECIALLY ACROSS THE HIGHER TERRAIN OF THE NORTHWEST. A SLOW-
MOVING FRONTAL SYSTEM WILL THEN DRAG ITS ATTENDANT FRONT ACROSS
THE GREAT LAKES AND THE NORTHEASTERN CONUS SUNDAY AND MONDAY,
BRINGING A PROLONGED PERIOD OF SHOWERS AND POSSIBLE THUNDERSTORMS.
THE UPPER LOW ASSOCIATED WITH THIS SYSTEM WILL THEN BRING MORE
SCATTERED SHOWERS TO THE REGION ON TUESDAY.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
NEAR TERM: MVFR TO IFR TONIGHT W/SHOWERS AND TSTMS. THE BEST TSTM
ACTIVITY WILL BE N OF KBGR AND KBHB. FOG WILL BE A THREAT FOR KBGR
AND KBHB LATER TONIGHT INTO EARLY WEDNESDAY. COLD FROPA WEDNESDAY
MORNING W/CONDITIONS IMPROVING TO VFR BY MIDDAY. THE CAVEAT TO
THIS WILL BE ACROSS THE NORTHERN TERMINALS AS CIGS COULD DROP TO
MVFR FOR A PERIOD WEDNESDAY AFTERNOON.
SHORT TERM: EXPECT VFR CONDITIONS WEDNESDAY NIGHT THEN MVFR/VFR
CONDITIONS THURSDAY THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM: FOG KEEPING NAVIGATION TRICKY W/VSBYS BELOW 1 NM. KEPT
FOG THROUGH MIDDAY WEDNESDAY UNTIL GOOD MIXING W/WINDS VEERING TO
THE W ALLOWING FOR CLEARING. BROUGHT WINDS UP TO 10-15KT WEDNESDAY
MORNING BEHIND THE FRONT. WAVE HEIGHTS TO BE NO MORE THAN 3 FT AND
THIS WILL BE MAINLY OVER THE OUTER WATERS.
SHORT TERM: FOR SUSTAINED WINDS HAVE USED A 50/50 BLEND OF THE
NAM12 AND GFS40. FOR WAVES: WITH LIGHT WINDS EXPECTED WEDNESDAY
NIGHT THROUGH FRIDAY THE PRIMARY WAVE SYSTEMS WILL BE COMPOSED OF
LONG PERIOD WAVE GROUPS COMBINING TO PRODUCE 1 TO 2 FOOT SEAS. THE
COMBINED SEAS COMPOSED OF SOUTHERLY 6 SECOND GROUP AND
SOUTHEASTERLY 9-10 SECOND GROUP. WILL USE THE NEAR SHORE WAVE
MODEL TO POPULATE WAVE HEIGHT GRIDS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...CB/HEWITT
SHORT TERM...MIGNONE
LONG TERM...HASTINGS
AVIATION...CB/HEWITT/MIGNONE
MARINE...CB/HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
418 PM EDT TUE JUL 21 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TONIGHT. AN UPPER LEVEL TROUGH
WILL SWING ACROSS THE REGION ON WEDNESDAY WITH ANOTHER FRONTAL
BOUNDARY FOR THURSDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
SCATTERED THUNDERSTORMS EXPECTED INTO TONIGHT W/HEAVY RAINFALL
POTENTIAL AND CLOUD TO GROUND LIGHTNING. SOME STRONGER STORMS
COULD CONTAIN BRIEF WIND GUSTS ESPECIALLY W/THE ARRIVAL OF THE
COLD FRONT LATER THIS EVENING. SPC UPDATED THE DAY1 OUTLOOK W/A
MARIGNAL RISK FOR WESTERN MAINE THROUGH THE EVENING.
THE MAIN ACTION ATTM WAS ACROSS FAR WNW MAINE W/TRAINING CELLS
AND VERY HEAVY RAINFALL PER THE LATEST RADAR LOOP. RADAR
ESTIMATES OF UP TO 2"/HR IN THE STRONGER CELLS. CELLS MOVING ALONG
THE UPPER SW FLOW ALLOWING FOR RE-GENERATION OF THE STORMS AND
THEREFORE HEAVY RAINFALL POTENTIAL. PWATS IN THIS REGION UP AROUND
1.5 INCHES W/GOOD MOISTURE TRANSPORT FROM 925-850MBS PER THE
LATEST MESO- ANALYSIS. THIS ACTIVITY WAS IGNITING ALONG A PRE-
FRONTAL TROF WELL FORECASTED BY THE MIDNIGHT CREW. LOCALIZED
FLOODING POSSIBLE IN THIS AREA. FURTHER E, ATMOSPHERE MORE STABLE
THANKS TO A SSE FLOW AND CLOUD COVER LIMITING HEATING. ACTIVITY TO
THE W IS FORECAST TO BREAK UP AS IT PUSHES E INTO THE EVENING.
ANOTHER ORGANIZED LINE OF CONVECTION IS SHOWN BY MESOSCALE
GUIDANCE INCLUDING THE NAM12 AND HRRR 3KM MODEL TO MOVING ACROSS
THE NORTHERN 1/2 OF THE CWA THIS EVENING INTO EARLY TONIGHT. THIS
ACTION WILL BE IN ASSOCIATION W/THE MAIN COLD FRONT. SOUNDING
PROFILES NOT OVERLY IMPRESSIVE FOR STRONG CONVECTION, BUT MUCAPES
OF 600+ JOULES AND COLUMN MOISTENING UP THROUGH 700MBS LATER THIS
EVENING PLUS INCREASING MID LEVEL SHEAR WILL ALLOW FOR SOME DECENT
SHOWERS/STORMS. AGAIN, HEAVY RAINFALL AND LIGHTNING THE MAIN
THREAT. DECIDED TO GO W/BASIN QPF OF 1.25+ INCHES THROUGH WEST AND
NORTHWEST MAINE THROUGH MIDNIGHT DUE TO THE TRAINING CELLS.
ALL ACTION WILL WEAKEN AND PUSH TO THE ESE LATER TONIGHT W/COOLER
AND DRIER AIR BEHIND THE FRONT BY WEDNESDAY MORNING. DECIDED TO
ADD FOG INTO THE FORECAST TONIGHT BEFORE THE FROPA W/DEEP LLVL
MOISTURE IN PLACE. DOWNEAST AND THE COAST WILL HAVE THE BEST SHOT
AS SEEING THE FOG. UNSETTLED ON WEDNESDAY W/THE UPPER TROF AXIS
FORECAST TO ACROSS THE REGION. BEST MOISTURE AVAILABLE LOOKS TO BE
IN THE LLVLS AROUND 850MBS. SOME INSTABILITY IS THERE BUT MARGINAL
AND LOW/MID LEVEL LAPSE RATES ARE WEAK. THEREFORE, DECIDED TO
LEAN AWAY FROM THE MENTION OF TSTMS AND KEPT JUST SHOWERS ATTM.
LATER CREWS CAN ASSESS THIS FURTHER W/THE LATEST GUIDANCE.
TEMPERATURES WILL CONTINUE TO BE BELOW NORMAL FOR JULY.
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
THE REGION IS EXPECTED TO REMAIN IN A CYCLONIC FLOW ON THE BACK
SIDE OF SURFACE LOW PRESSURE LOCATED TO THE EAST OF NOVA SCOTIA
ALONG WITH AN UPPER LEVEL SYSTEM TO THE NORTHWEST. IN ADDITION THE
UPPER LEVEL SYSTEM IS EXPECTED TO MOVE SOUTHEAST WARD AND CROSS
OVER THE NORTHERN AND EASTERN PORTION OF MAINE FRIDAY. THIS IS
EXPECTED TO RESULT IN SHOWERS... ESPECIALLY IN THE NORTH AND
DURING DAYLIGHT HOURS. WILL BLEND THE GFS AND ECMWF FOR POPS...
QPF AND SKY. FOR MAXIMUM TEMPERATURE WILL USE THE CONSENSUS RAW.
FOR MINIMUM TEMPERATURE HAVE USED THE CONSENSUS ALL. WILL USE THE
MOSG25 FOR WINDS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPPER LOW WILL PULL AWAY FROM NEW ENGLAND FRIDAY NIGHT INTO
SATURDAY, FOLLOWED BY A VERY BRIEF RIDGE OF HIGH PRESSURE. AS
SUCH, THE FIRST PART OF THE WEEKEND WILL HAVE THE LOWEST CHANCES
FOR RAIN, THOUGH A FEW SHOWERS CAN`T BE TOTALLY RULED OUT,
ESPECIALLY ACROSS THE HIGHER TERRAIN OF THE NORTHWEST. A SLOW-
MOVING FRONTAL SYSTEM WILL THEN DRAG ITS ATTENDANT FRONT ACROSS
THE GREAT LAKES AND THE NORTHEASTERN CONUS SUNDAY AND MONDAY,
BRINGING A PROLONGED PERIOD OF SHOWERS AND POSSIBLE THUNDERSTORMS.
THE UPPER LOW ASSOCIATED WITH THIS SYSTEM WILL THEN BRING MORE
SCATTERED SHOWERS TO THE REGION ON TUESDAY.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
NEAR TERM: MVFR TO IFR TONIGHT W/SHOWERS AND TSTMS. THE BEST TSTM
ACTIVITY WILL BE N OF KBGR AND KBHB. FOG WILL BE A THREAT FOR KBGR
AND KBHB LATER TONIGHT INTO EARLY WEDNESDAY. COLD FROPA WEDNESDAY
MORNING W/CONDITIONS IMPROVING TO VFR BY MIDDAY. THE CAVEAT TO
THIS WILL BE ACROSS THE NORTHERN TERMINALS AS CIGS COULD DROP TO
MVFR FOR A PERIOD WEDNESDAY AFTERNOON.
SHORT TERM: EXPECT VFR CONDITIONS WEDNESDAY NIGHT THEN MVFR/VFR
CONDITIONS THURSDAY THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM: FOG KEEPING NAVIGATION TRICKY W/VSBYS BELOW 1 NM. KEPT
FOG THROUGH MIDDAY WEDNESDAY UNTIL GOOD MIXING W/WINDS VEERING TO
THE W ALLOWING FOR CLEARING. BROUGHT WINDS UP TO 10-15KT WEDNESDAY
MORNING BEHIND THE FRONT. WAVE HEIGHTS TO BE NO MORE THAN 3 FT AND
THIS WILL BE MAINLY OVER THE OUTER WATERS.
SHORT TERM: FOR SUSTAINED WINDS HAVE USED A 50/50 BLEND OF THE
NAM12 AND GFS40. FOR WAVES: WITH LIGHT WINDS EXPECTED WEDNESDAY
NIGHT THROUGH FRIDAY THE PRIMARY WAVE SYSTEMS WILL BE COMPOSED OF
LONG PERIOD WAVE GROUPS COMBINING TO PRODUCE 1 TO 2 FOOT SEAS. THE
COMBINED SEAS COMPOSED OF SOUTHERLY 6 SECOND GROUP AND
SOUTHEASTERLY 9-10 SECOND GROUP. WILL USE THE NEAR SHORE WAVE
MODEL TO POPULATE WAVE HEIGHT GRIDS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...MIGNONE
LONG TERM...HASTINGS
AVIATION...HEWITT/MIGNONE
MARINE...HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
146 PM EDT TUE JUL 21 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM EDT TUE JUL 21 2015
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW A NW FLOW ALOFT
OVER THE UPR LKS BTWN CLOSED LO NEAR JAMES BAY AND UPR RDG OVER THE
ROCKIES/WRN PLAINS. A DISTURBANCE DROPPING SEWD THRU NW ONTARIO
IN CONCERT WITH SOME MSTR IN THE H85-7 LYR SHOWN ON THE 00Z INL/YPL
RAOBS IS BRINGING SCT-BKN AC THRU MUCH OF NW ONTARIO...NRN MN AND
LK SUP. FARTHER TO THE W IN MANITOBA CLOSER TO THE UPR RDG AXIS
AND UNDER STRONGER DEEP LYR QVECTOR DVGC...THE 00Z THE PAS RAOB AT
THE NRN END OF LK WINNIPEG SHOWS A MUCH SHARPER MID LVL INVRN. SKIES
IN THIS AREA ARE MOCLR. DESPITE SOME RELATIVELY DRY LLVL AIR AND
LLVL CAA...STEADY NW WINDS UNDER SHARPER PRES GRADIENT WELL E OF HI
PRES CENTER IN THE NRN PLAINS HAS LIMITED THE DIURNAL TEMP DROP.
RELATIVELY QUIET QUIET WX WL DOMINATE THE SHORT TERM. MAIN FCST
CONCERNS FOCUS ON CLD TRENDS TODAY AND TEMPS TODAY/TNGT.
TODAY...SHRTWV DIGGING SEWD THRU NW ONTARIO IS FCST TO BE OVER NE LK
SUP BY 12Z AND THEN OVER SE ONTARIO BY 00Z THIS EVNG...WITH DNVA/
SHARPER DEEP LYR QVECTOR OVER THE UPR LKS IN ITS WAKE BRINGING 12HR
H5 HGT RISES UP TO 50M IN ITS WAKE. EXPECT SCT-BKN CU TO DEVELOP BY
LATE MRNG WITH DAYTIME HEATING UNDER H85 THERMAL TROF/LINGERING
MSTR...BUT TENDENCY DURING THE AFTN SHOULD BE FOR THE CU TO SCT OUT
WITH SHARPENING SUBSIDENCE INVRN/ARRIVAL OF DRIER AIR SHOWN ON THE
PAS RAOB. SOME OF THE HI RES MODELS EVEN GENERATE SOME ISOLD
SHOWERS OVER THE ECNTRL CWA TOWARD NOON...BUT WL MAINTAIN DRY FCST
FOR NOW GIVEN RELATIVELY STABLE MID LYRS SHOWN ON THE UPSTREAM
RAOBS/FCST SDNGS. WINDS MAY ALSO GET A BIT GUSTY AGAIN THIS MRNG
UNDER SHARPER PRES GRADIENT/STEEPENING LLVL LAPSE RATES...BUT SFC HI
PRES MOVING OVER THE CWA IN THE AFTN SHOULD RESULT IN DIMINISHING
WINDS. THE MORE PERSISTENT GUSTY WINDS WL BE OVER THE E...WHERE THE
TIGHTER GRADIENT WL LINGER LONGER AND LK BREEZE COMPONENT OFF LK SUP
WL ACCENTUATE THIS FLOW. EXPECT THE LOWEST MAX TEMPS IN THIS AREA AS
WELL WITH MORE LK SUP MODERATION. LOCATIONS NEAR THE SHORE E OF MQT
WL SEE HI TEMPS HOLDING IN THE 60S. AS H85 TEMPS REBOUND TO NEAR 12Z
ALONG THE WI BORDER LATER IN THE DAY...THE MERCURY SHOULD RISE WELL
INTO THE 70S AND AT LEAST APRCH 80 AT A FEW LOCATIONS OVER THE
SCENTRAL WITH DOWNSLOPE FLOW AND LIMITED LK BREEZE OFF LK MI.
TNGT...EXPECT LINGERING CU TO DSPT EARLY AND GIVE WAY TO MOCLR
SKIES UNDER LARGER SCALE SUBSIDENCE/LOSS OF DAYTIME HEATING. LO
TEMPS WL BE COOLEST OVER THE W CLOSER TO SFC HI PRES RDG AXIS APRCHG
WRN LK SUP/WEAKER PRES GRADIENT. THE COOL SPOTS MAY SEE THE
THERMOMETER READ AS LO AS 45 BY DAYBREAK.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM EDT TUE JUL 21 2015
IMPACTS...NO SIGNIFICANT IMPACTS ARE WITHIN PREDICTABLE RANGE.
POSSIBILITY FOR STRONG TO SEVERE STORMS OVER PARTS OF THE REGION
LATE FRI INTO SAT...BUT STILL VERY UNCERTAIN ON THAT ASPECT.
MAY SEE SHOWERS AND THUNDERSTORMS ALONG AND/OR NEAR THE WI BORDER
THU AS MODELS SHOW A WARM FRONT MOVING INTO THE AREA FROM THE
W...WHICH MAINLY INCREASES MID LEVEL MOISTURE ENOUGH TO ALLOW FOR
WEAK CONVECTIVE POTENTIAL. MODELS ARE SLOWER WITH THE FRONT THAN
THEY WERE YESTERDAY...SO WILL CONTINUE TREND OF LOWERING DEW POINTS
ON WED AFTERNOON...BUT FIRE WEATHER CONCERNS WILL BE MINIMAL GIVEN
LIGHT WINDS. WILL KEEP SLIGHT CHANCE POPS INTO AREAS ALONG THE WI
BORDER THU.
THE DISTURBANCE THAT THE WARM FRONT IS TIED TO WILL MOVE ACROSS
MANITOBA CANADA AND HUDSON BAY FRI INTO SUN...DRAGGING A SFC
TROUGH/COLD FRONT THROUGH THE AREA. DEFINITELY SOME DIFFERENCES
BETWEEN MODELS WITH THIS SYSTEM...WITH THE 00Z/21 GFS BEING STRONGER
AND FARTHER S THAN THE 12Z/20 ECMWF. WILL USE CONSENSUS GUIDANCE
GIVEN THE UNKNOWNS INVOLVED...WHICH WILL SHOW SHOWERS AND
THUNDERSTORMS MOVING W TO E ACROSS THE CWA FROM LATE FRI THROUGH
SAT. SUN LOOKS DRY FOR NOW. DEPENDING ON TIMING AND OTHER
FACTORS...COULD SEE INGREDIENTS COME TOGETHER FOR SOME STRONG TO
SEVERE STORMS MAINLY S OF THE CWA.
SUN LOOKS DRY AND MON MAY SEE SOME RAIN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 145 PM EDT TUE JUL 21 2015
SCT-BKN VFR CUMULUS AND STRATOCUMULUS CLOUDS WILL AFFECT MAINLY KIWD
AND KSAW REST OF THE AFTN...WHILE CLOUDS TRY TO CLEAR OUT AT KCMX.
GUSTY WINDS...PERHAPS BRIEFLY TO 20 KTS...WILL DIMINISH LATE IN THE
AFTN INTO THIS EVENING AS HIGH PRESSURE OVER THE PLAINS DRAWS CLOSER.
AS THE RIDGE CROSSES TONIGHT...EXPECT SKIES TO TURN MOSTLY CLEAR WITH
WINDS BECOMING LIGHT. VFR CONDITIONS WILL CONTINUE INTO WEDNESDAY
WITH SCT-BKN DAYTIME CUMULUS CLOUDS. WINDS SHOULD NOT BE AS GUSTY AS
TODAY. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 AM EDT TUE JUL 21 2015
STEADY WNW WINDS UP TO ABOUT 20 KTS WILL DIMINISH TONIGHT WITH THE
CLOSER APPROACH OF HI PRES FROM THE NORTHERN PLAINS. SINCE THE HI
PRES WILL LINGER NEAR THE GREAT LAKES MUCH OF THIS WEEK...WINDS
SHOULD BE UNDER 20 KTS MOST OF THE TIME. SOME STRONGER WINDS UP TO
20 KTS WILL BE POSSIBLE ON FRI/SAT AS A COLD FRONT CROSSES THE
REGION.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...JLA
MARINE...KC
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1226 PM CDT TUE JUL 21 2015
.DISCUSSION... /ISSUED 308 AM CDT TUE JUL 21 2015/
CURRENTLY A SNAKING LINE OF CONVECTION EXTENDING FROM THE TEXAS
PANHANDLE TO EASTERN KENTUCKY CONTINUES TO FIZZLE MIDWAY ACROSS
THE MIDSOUTH THIS MORNING...LEAVING ONLY A FEW SHOWERS IN EASTERN
ARKANSAS AND A BLANKET OF MID AND HIGH LEVEL MOISTURE. CLOUD COVER
WAS KEEPING TEMPERATURES A DEGREE OR TWO WARMER THAN THIS TIME
LAST NIGHT FROM I-40 SOUTH...WHILE EVENING RAIN EARLIER AND A WEAK
OUTFLOW BOUNDARY IS PROVIDING COOLER TEMPERATURES FARTHER NORTH.
THE HRRR SHOWS NEW CONVECTION FORMING ACROSS THE NORTH BY 4
AM...BUT RADAR TRENDS AND MESOANALYSIS IS SUGGESTING MORE
STABILITY IN THIS REGION.
FOR TODAY THROUGH THURSDAY...THE MIDSOUTH WILL TAKE A SHORT BREAK
FROM THE HEAT THIS PERIOD...WITH THE ONLY EXCEPTION BEING THE
SOUTHERN TWO TIER OF COUNTIES TODAY....WHERE A HEAT ADVISORY IS
IN EFFECT STARTING LATER THIS MORNING. THE UPPER RIDGE IS EXPECTED
TO SAG FAR ENOUGH SOUTH TO ALLOW THE PREVAILING WESTERLIES...AND
ASSOCIATED DISTURBANCES TO PASS OVER A STALLED SURFACE FRONT.
EACH FEATURE ALLOWING THE CHANCE FOR SHOWERS AND STORMS TO
FORM...WITH A NEAR EQUAL THREAT BOTH DAY AND NIGHT. TOMORROW
APPEARS THE COOLEST BY THE MODELS WITH PLENTY OF HIGHS IN THE 80S
AND WIDESPREAD HEAT INDICES FINALLY DIPPING BELOW 100F. THE
BIGGER QUESTION IS WILL THERE BE A THREAT FOR SEVERE WEATHER OR
FLASH FLOODING. MU CAPE VALUES BY THE MID AFTERNOON HOURS WILL
RANGE FROM 2000 TO 3500 J/KG AND THE POSSIBILITY OF STORMS
TRAINING SEEMS VERY PLAUSIBLE. FEEL PULSE TYPE STORMS WILL
DEVELOP TODAY AND TOMORROW WITH THE GREATER POTENTIAL FOR
SOMETHING MORE ORGANIZED HAPPENING TOMORROW NIGHT AND THURSDAY
WHEN A 25KT LLJ AT 850MB INTERSECTS THE REGION. WILL KEEP THE
SAME MENTION IN THIS MORNINGS HWO WITH THE ADDITION OF A LOCALIZED
FLASH FLOODING THREAT.
FRIDAY THROUGH MONDAY...THE GFS AND EURO ARE IN GOOD AGREEMENT
THAT THE RIDGE WILL BUILD BACK NORTH...BUT THERE ARE SLIGHT
DIFFERENCES ON JUST HOW FAR EAST. THE FARTHER WEST EURO SOLUTION
WOULD KEEP THE MIDSOUTH IN THE CROSSHAIRS FOR MORE MCS
CONVECTION/NORTHWESTERLY FLOW...WHILE THE GFS IS A BIT HOTTER AND
DRIER AS THE RIDGE MOVES INTO THE TENNESSEE RIVER VALLEY. THIS
WOULD LEAD TO PERHAPS ISOLATED DIURNAL CONVECTION AT BEST. FOR
NOW HAVE LEANED MORE TOWARDS THE GFS...AS IT IS HANDLING THE
CURRENT SITUATION BETTER. HIGHS WOULD CLIMB BACK INTO THE MID AND
UPPER 90S...AND THE NEED FOR ADDITIONAL HEAT PRODUCTS LIKELY.
JAB
&&
.AVIATION...
18Z TAF SET
VFR CONDITIONS GENERALLY EXPECTED OVER THE NEXT 24 HOURS. DIURNAL
SHRAS/TSRAS EXPECTED TO DEVELOP BETWEEN 19-21Z ACROSS THE AREA.
THE STORMS SHOULD DISSIPATE BY 3Z. IF A TSRA WOULD HIT A TAF
LOCATION...CONDITIONS COULD DETERIORATE TO MVFR OR LOWER. NOT
ENOUGH CONFIDENT TO PUT ANY TEMPO GROUP IN AT THIS POINT. IN
ADDITION...A MCS MAY DEVELOP OVERNIGHT AND APPROACH KJBR AROUND
9Z AND POSSIBLY KMEM AROUND 12Z. FOR NOW JUST MENTIONED VCTS OR
VCSH WORDING. WINDS WILL GENERALLY BE LIGHT AND VARIABLE.
KRM
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR PHILLIPS.
MO...NONE.
MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CALHOUN-CHICKASAW-
COAHOMA-ITAWAMBA-LAFAYETTE-LEE MS-MONROE-PANOLA-PONTOTOC-
QUITMAN-TALLAHATCHIE-UNION-YALOBUSHA.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AMARILLO TX
432 PM CDT TUE JUL 21 2015
.DISCUSSION...
PRIMARY FOCUS CONTINUES TO BE POTENTIAL FOR ADDITIONAL FLOODING
TONIGHT AS MANY LOCATIONS ARE SATURATED FROM LAST NIGHT. 12Z SOUNDING
SHOWS SIGNIFICANT CONVECTIVE OVERTURNING WITH VERY SHALLOW LOW LEVEL
MOISTURE AND A MARKED DECREASE IN MOISTURE JUST ABOVE THAT THROUGHOUT
THE LOW LEVELS. MID-HIGH LEVEL CLOUDS KEPT THE AREA FROM
DESTABILIZATION AS SIGNIFICANTLY AS YESTERDAY AND ABSENCE OF ANY
WELL DEFINED SURFACE BOUNDARIES HAS YIELDED A FAIRLY UNIFORM CUMULUS
FIELD PER VISIBLE SATELLITE THIS AFTERNOON. SOME TERRAIN INDUCED
CONVECTION IN NEW MEXICO HAS FORMED BUT OVERALL EXPANSIVENESS IS FAR
LESS THAN YESTERDAY AT THIS TIME. WATER VAPOR LOOP AND RAP PV
ANALYSIS SHOW ONE WAVE TRAVERSING THE PANHANDLES NOW WITH SUBSIDENCE
FOLLOWING THIS FEATURE ALREADY OVERSPREADING THE WESTERN PORTION OF
THE AREA. HAVE SIGNIFICANTLY LOWERED PRECIPITATION PROBABILITIES
TONIGHT GIVEN TRENDS.
MID LEVEL HEIGHTS RISE AS RIDGE ONCE AGAIN AMPLIFIES. THIS SHOULD
LIMIT COVERAGE OF CONVECTION FOR MUCH OF THE WEEK. ISOLATED
THUNDERSTORMS MAY OCCUR MAINLY OVER THE FAR NORTHWEST PORTION OF THE
AREA. THE RIDGE WEAKENS AGAIN SUFFICIENTLY FOR AN INCREASE IN
PRECIPITATION PROBABILITIES ESPECIALLY ACROSS THE NORTHERN PORTION
OF THE AREA SATURDAY AND SUNDAY.
BRB
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 66 89 69 93 71 / 30 10 20 10 10
BEAVER OK 66 90 69 98 72 / 40 10 10 10 10
BOISE CITY OK 63 91 66 94 67 / 30 20 20 20 20
BORGER TX 69 93 72 96 73 / 30 10 10 10 10
BOYS RANCH TX 67 94 70 96 71 / 30 20 20 10 10
CANYON TX 66 91 68 94 70 / 30 10 20 10 10
CLARENDON TX 68 92 71 95 72 / 30 10 10 5 5
DALHART TX 65 94 67 96 68 / 30 20 20 20 10
GUYMON OK 66 93 68 97 70 / 40 10 10 10 20
HEREFORD TX 66 92 68 94 69 / 30 20 20 10 10
LIPSCOMB TX 68 91 71 98 73 / 40 10 10 10 10
PAMPA TX 66 89 69 94 70 / 30 10 10 10 10
SHAMROCK TX 69 93 71 97 72 / 30 5 5 5 5
WELLINGTON TX 70 95 72 98 73 / 30 5 5 5 5
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
01/17
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
315 PM CDT TUE JUL 21 2015
.SHORT TERM...
MORE RAIN IS EXPECTED AGAIN LATER THIS AFTERNOON AND EVENING FOR
WEST TEXAS...THIS TIME WITH A BIT MORE COVERAGE THAN LAST NIGHT IF
THE FORECAST PANS OUT AS EXPECTED. MODELS PRE-12Z WERE VERY
SKEPTICAL AND DIFFERED GREATLY ON WHERE AND WHEN CONVECTION WOULD
OCCUR LATER TODAY. WHILE SOME QUESTIONS STILL REMAIN...MOST MODELS
MINUS THE HRRR HAVE COME INTO AGREEMENT THAT CONVECTION SHOULD
SPREAD FARTHER SOUTH AND EAST THAN YESTERDAY AFTERNOON. THE 12Z NAM
SEEMED TO HAVE AT FIRST GLANCE THE BEST HANDLE ON THE FORECAST AS IT
PICKED UP ON AN AREA OF LIFT OVER SOUTH-CENTRAL NM WHICH STARTED
TO SHOW UP ON WV JUST AFTER 13Z. THE AREA OF LIFT HAS SINCE
ENHANCED FURTHER AND HAS AIDED IN THE DEVELOPMENT OF EASTWARD
PROPAGATING THUNDERSTORMS JUST EAST OF RUIDOSO NM. THESE STORMS
SHOULD GRADUALLY MAKE THEIR WAY TOWARDS THE TX/NM STATE LINE BY
THE LATE AFTERNOON/EARLY EVENING. ANOTHER AREA OF INTEREST FOR
SHOWER AND THUNDERSTORM DEVELOPMENT IS A WESTWARD PROPAGATING
SURFACE BOUNDARY ACROSS THE WESTERN THIRD OF THE FA. HIGHER RES
MODELS...EVEN THE HRRR TO AN EXTENT...HAVE HINTED AT CONVECTIVE
DEVELOPMENT ALONG THIS BOUNDARY WITHIN THE NEXT FEW HOURS AS
MLCAPE INCREASES TO AROUND 1500 J/KG. THE AMOUNT OF CAPE THAT WILL
BECOME AVAILABLE WILL DEPEND ON HOW MUCH ADDITIONS SURFACE HEATING
CAN BE ACHIEVED AS TEMPS ARE COOLER THAN EXPECTED THIS AFTERNOON
DUE TO CLOUD COVER THAT LINGERED INTO MID DAY. THE MAIN
THREAT...AS IS USUALLY OUT HERE IN THESE PARTS...FROM CONVECTION
WOULD BE STRONG TO POSSIBLY MARGINALLY SEVERE WINDS ASSOCIATED
WITH DOWNBURSTS. HEAVY RAIN WILL ALSO BE A VALID THREAT AS WAS
SEEN YESTERDAY EVENING.
RAIN CHANCES WILL DIMINISH OVERNIGHT AS THE ATMOSPHERE COOLS AND
STABILIZES. THE RIDGE WILL SLOWLY PUSH BACK INTO THE REGION MAKING
WAY FOR HEIGHT RISES TOMORROW WHICH WILL GREATLY DECREASE STORM
CHANCES ACROSS THE FA TOMORROW AFTERNOON. THE BEST CHANCES WILL BE
IN OUR WESTERN ZONES WHICH WILL BE LOCATED NEAR THE WESTERN EDGE OF
THE RIDGE. HIGH TEMPS TOMORROW WILL BE DEPENDENT UPON CONVECTIVE
COVERAGE TONIGHT WHICH COULD COOL TEMPS BY SEVERAL DEGREES. FOR NOW
MID 90S ON THE CAPROCK/UPPER 90S ACROSS THE ROLLING PLAINS WILL BE
MAINTAINED. ALDRICH
.LONG TERM...
CHANCES OF PRECIPITATION WILL BE FLEETING BY THURSDAY AFTERNOON ON
THE WESTERN EDGE OF AN UPPER LEVEL RIDGE MOVING OVERHEAD. HEIGHT
RISES WILL LIKELY SQUASH ANY CONVECTION LOCALLY. AFTERNOON/EVENING
STORMS ARE STILL LIKELY ACROSS NEW MEXICO WITHIN SURFACE TROUGHING
WELL WEST OF THE REGION. THERE IS SOME CHANCE BUT VERY LITTLE OF
ANY STORMS BEING ABLE TO CROSS STATE LINES THROUGH EARLY NEXT
WEEK. LATEST MOS GUIDANCE HAS CONTINUED ITS WARM BIAS ON MAX
TEMPERATURES AND WILL CONTINUE TO FORECAST BELOW MOS...CLOSER TO
BIAS CORRECTED GUIDANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 64 90 67 94 / 40 20 20 20
TULIA 66 92 69 95 / 40 10 20 10
PLAINVIEW 68 91 70 94 / 40 10 20 0
LEVELLAND 68 93 71 95 / 30 20 20 10
LUBBOCK 72 94 72 97 / 30 20 10 0
DENVER CITY 69 94 70 95 / 30 20 20 20
BROWNFIELD 69 94 71 96 / 30 20 20 0
CHILDRESS 73 98 75 101 / 40 10 10 0
SPUR 70 94 73 96 / 30 10 10 0
ASPERMONT 73 98 76 101 / 20 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
51/01
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1228 PM CDT TUE JUL 21 2015
.AVIATION...
THE UPPER LEVEL RIDGE LINGERING OVER THE REGION FOR THE PAST SEVERAL
DAYS WILL WEAKEN SLIGHTLY AND SHIFT A LITTLE TO THE SOUTH THROUGH
WEDNESDAY. AT THE SURFACE...A WEAK FRONT HAS WORKED SOUTHWARD THE
PAST 24 HOURS AND WAS NOW STATIONARY ALONG A MIDLAND TO WICHITA
FALLS TO PINE BLUFF LINE. AREAS ALONG AND NORTH OF THIS FRONT WILL
REMAIN CONVECTIVELY ACTIVE WITH STRONG TO SEVERE STORMS DURING
THIS TAF FORECAST.
NORTH/CENTRAL TEXAS TERMINALS WILL REMAIN VFR WITH SOME HIGH
CLOUDS AND LIGHT SOUTHERLY WINDS DURING THIS FORECAST CYCLE.
GROUND OPERATIONS WILL EXPERIENCE AFTERNOON HEAT INDICES IN THE
100 TO 103 DEGREE RANGE TODAY AND AGAIN ON WEDNESDAY. LOOKING
AHEAD...NO SIGNIFICANT CHANGES ARE FORESEEN THE REST OF THE WEEK.
75
&&
.PREV DISCUSSION... /ISSUED 328 AM CDT TUE JUL 21 2015/
THE UPPER LEVEL RIDGE THAT HAS DOMINATED THE WEATHER ACROSS THE
REGION FOR THE LAST WEEK IS SHOWING SOME SIGNS OF A SLIGHT
WEAKENING AS A SHORT WAVE MOVES ACROSS ITS NORTHERN PERIPHERY.
THIS HAS ALLOWED A COLD FRONT TO MOVE DOWN INTO NORTHERN OKLAHOMA
AND WEST TEXAS. THIS FRONT WILL STALL OUT ACROSS CENTRAL OKLAHOMA
INTO WEST TEXAS THIS AFTERNOON OR EVENING BEFORE LIFTING BACK TO
THE NORTH BY WEDNESDAY MORNING.
SOME OF THE HIGH CLOUDS ASSOCIATED WITH CONVECTION ACROSS
OKLAHOMA AND THE TEXAS PANHANDLE WILL ATTEMPT TO MOVE INTO NORTH
TODAY BUT THESE CLOUDS SHOULD THIN. THE MAIN AREA OF DENSER CLOUDS
WILL MOVE EAST ACROSS OKLAHOMA. TEMPERATURES TODAY SHOULD BE A
DEGREE OR TWO COOLER VERSUS YESTERDAY THANKS TO THE WEAKENING
RIDGE. EXPECT HIGHS IN THE MID 90S TO NEAR 100 DEGREES ACROSS THE
REGION. THE HRRR INDICATES THAT SOME ISOLATED
SHOWERS/THUNDERSTORMS WILL TRY TO FORM THIS AFTERNOON FROM
GRANBURY THROUGH THE METROPLEX NORTHEAST TOWARD PARIS. THE
SUBSIDENCE ASSOCIATED WITH THE RIDGE WILL PROBABLY BE TOO STRONG
FOR THIS TO OCCUR SO HAVE JUST PLACED 10 PERCENT POPS WITH NO
WEATHER MENTIONED FOR THIS AFTERNOON AND EVENING ALONG AND NORTH
OF A COMANCHE TO EMORY LINE.
THE UPPER RIDGE WILL SHIFT WEST INTO WEST TEXAS AND RE-STRENGTHEN
LATE WEEK. THIS WILL ALLOW TEMPERATURES TO INCREASE BY A FEW
DEGREES LATE WEEK THROUGH THE WEEKEND. WE MAY BE REACH HEAT
ADVISORY CRITERIA ACROSS THE EASTERN THIRD TO HALF SUNDAY/MONDAY.
THE ECMWF AND GFS INDICATE THAT THE RIDGE WILL SHIFT A LITTLE TO
THE NORTH EARLY TO MID NEXT WEEK...WHICH MAY ALLOW FOR SOME LOW
RAIN CHANCES ACROSS THE SOUTHEASTERN AND SOUTHERN ZONES BY THE
MIDDLE OF NEXT WEEK. 58
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 98 79 98 79 99 / 10 5 5 0 0
WACO, TX 97 75 97 75 98 / 0 0 0 0 0
PARIS, TX 97 76 96 75 96 / 10 10 10 0 0
DENTON, TX 98 77 98 78 99 / 10 10 10 0 0
MCKINNEY, TX 96 77 97 78 98 / 10 5 10 0 0
DALLAS, TX 99 80 99 81 100 / 10 5 5 0 0
TERRELL, TX 97 76 96 76 99 / 10 5 5 0 0
CORSICANA, TX 98 76 97 76 99 / 0 0 5 0 0
TEMPLE, TX 97 74 96 75 97 / 0 0 0 0 0
MINERAL WELLS, TX 96 75 96 75 98 / 10 5 5 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
75
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1213 PM CDT Tue Jul 21 2015
.AVIATION...
/18Z TAFS/
Look for VFR conditions to continue for the next 24 hours. All
available short-term model data indicate stratus return tonight not
likely. Thus, persistence forecast looks good.
&&
.PREV DISCUSSION... /ISSUED 642 AM CDT Tue Jul 21 2015/
AVIATION...
/12Z TAFS/
The low clouds over the Hill Country dissipated this morning
before reaching KJCT. This will spell VFR conditions across the
forecast area through the TAF period. Expect south winds around 10
kts this afternoon with a high based cu field (8,000-10,000 ft)
developing by midday. A few of the hi-res models continue to
indicate isolated convection this afternoon, mainly west of a
KSWW-KSJT line. However, any cells that develop should remain to
the north and west of the forecast terminals.
Johnson
PREV DISCUSSION... /ISSUED 411 AM CDT Tue Jul 21 2015/
SHORT TERM...
(Today and tonight)
One shortwave trough is lifting northeast across NM this morning,
providing large scale forcing for ascent across the Panhandle
and portions of west TX. At the surface, a cold front was located
from the south plains, extending northeast into central OK.
Outflow from evening convection is forcing the effective front to
the southeast, from near Vernon, to Jayton, to Midland as of 3 AM.
This boundary will likely move into the Big Country and western
Concho Valley this morning but is expected to erode by midday,
given the shallow nature of the "cool" airmass. This should have
only a slight effect on temperatures this afternoon, mainly over
the northwest quadrant of the CWA. Expect highs ranging from the
upper 90s to near 102 degrees this afternoon, with similar heat
indices.
A second shortwave trough is progged to lift northeast across NM
this afternoon and evening, providing another round of convection
to our north and west. The HRRR and ARW both indicate isolated
convection along the western periphery of the CWA this afternoon,
but the NAM, GFS, and ECMWF are largely dry. While a rogue
shower/storm can`t be ruled out this afternoon, coverage should be
significantly limited given the warm temps aloft, weak cap, and
depth of the boundary layer (increasing dry air entrainment into
potential updrafts). Thus, no PoPs will be carried in the
forecast. Expect partly cloudy conditions overnight with overnight
lows in the mid 70s.
Johnson
LONG TERM...
(Wednesday through next Monday)
By Wednesday, the frontal zone currently currently extending from
the TX panhandle into Oklahoma will be lifting northward into the
central plains. On Thursday, the upper level ridge will re-center
and strengthen directly over west Texas. With the ridge in place
across the southern plains through early next week, persistent
southwesterly flow across the Rocky Mountains will result in lee
troughing, and continue warm, southerly flow for our area through
the extended period. Due to this ridging and persistent southerly
flow, 850mb temperatures will warm a degree or two Celsius by
Monday. This will result in persistent hot and dry weather for our
area with highs in the upper 90s to around 100 degrees, lows in
the mid to upper 70s, and no chance for rainfall.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 76 98 76 98 77 / 5 0 0 0 0
San Angelo 75 100 76 99 76 / 0 0 0 0 0
Junction 74 98 74 97 75 / 0 0 0 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1150 AM CDT TUE JUL 21 2015
.AVIATION...
WHILE VFR CONDITIONS ARE EXPECTED TO PREVAIL OVER THE NEXT 24
HOURS SOME QUESTIONS EXIST OVER THE CHANCE FOR CONVECTION AT ALL
THREE TERMINALS LATER THIS AFTERNOON AND EVENING. CONFIDENCE IS
INCREASING OVER THE CHANCE OF TSRA MAINLY AT PVW AND LBB THIS
AFTERNOON...HOWEVER THERE ARE ENOUGH FACTORS THAT MAY INHIBIT
CONVECTION FROM REACHING THE TERMINALS THAT MENTION OF TSRA IN THE
TAF WILL BE LEFT OUT. IF CONFIDENCE CONTINUES TO INCREASE AS MORE
DATA BECOMES AVAILABLE THEN THE TAFS WILL BE AMENDED ACCORDINGLY.
THE BIGGEST THREAT FROM ANY CONVECTION THAT FORMS WILL BE STRONG
WINDS OVER 40 MPH.
&&
.PREV DISCUSSION... /ISSUED 400 AM CDT TUE JUL 21 2015/
SHORT TERM...
AS WAS EXPECTED...A FAIRLY LARGE MCS DEVELOPED ALONG AND BEHIND A
WEAK COLD FRONT RESULTING IN CONSIDERABLE AMOUNTS OF PRECIPITATION
ACROSS SOME AREAS IN THE NORTHERN PART OF OUR FORECAST AREA. THE
MCS DEVELOPED A STRONG OUTFLOW BOUNDARY WHICH SURGED THROUGH THE
LUBBOCK AREA BEFORE MIDNIGHT AND WAS LOCATED ALONG A SEMINOLE...
POST...TO KNOX CITY LINE AT 3 AM. THIS LEAVES ONLY STONEWALL COUNTY
TO THE SOUTHEAST OF THE OUTFLOW BOUNDARY. ALOFT...THE 00Z UPPER-AIR
ANALYSIS SHOWS THE CENTER OF THE HIGH PRESSURE RIDGE HAS SHIFTED A
BIT FURTHER SOUTH OVER SOUTH CENTRAL TEXAS WITH A GOOD MONSOON
MOISTURE PLUME LOCATED ACROSS NEW MEXICO CURVING BACK OVER THE TEXAS
PANHANDLE. IT WAS TOUGH TO PICK OUT ANY FORM OF SHORTWAVE ACTIVITY
IN THE UPPER-AIR ANALYSIS AND THE MCS HAS PUMPED CONSIDERABLE
MOISTURE INTO THE ATMOSPHERE AS SHOWN IN THE WATER VAPOR LOOP...ALSO
MASKING ANY SHORTWAVES THAT MAY BE SEEN OVER THE TEXAS PANHANDLE.
IT DOES HOWEVER SHOW A WEAK SWIRL OVER WESTERN NEW MEXICO THAT WILL
BE MOVING TOWARDS THE TEXAS PANHANDLE THROUGH THE DAY WHICH MAY COME
INTO PLAY LATER ON.
MODELS DID A POOR JOB INITIALIZING WITH THE CONVECTION AT 00Z WHICH
COMPLICATES THE FORECAST. THE ONLY MODEL THAT SEEMINGLY HAS A
DECENT START IS THE TTU-WRF AND LEANED HEAVILY TOWARDS THIS MODEL
FOR THE FORECAST THIS MORNING. THE MCS HAS ALREADY PUSHED EAST OUT
OF THE TEXAS PANHANDLE WITH OTHER LIGHTER SHOWER AND ISOLATED
THUNDERSTORMS DEVELOPING ACROSS THE WESTERN SOUTH PLAINS GENERALLY
ALONG AND WEST OF A TULIA TO BROWNFIELD LINE. TTU-WRF AND TO SOME
EXTENT THE NAM...HRRR...AND GFS DECREASE COVERAGE OF ACTIVITY
THROUGH THIS MORNING WITH A LULL IN PRECIPITATION BY MID-DAY.
EVENTUALLY...THE TTU-WRF REDEVELOPS SCATTERED CONVECTION ACROSS THE
WESTERN SOUTH PLAINS BY 21Z AND PUSHES THIS TO THE EAST TOWARDS THE
CAPROCK. THIS SOLUTION SEEMS REASONABLE AS CLOUD COVER WILL TAKE A
BIT TO DISSIPATE THROUGH THE MORNING AND THEN ALLOW SOME SURFACE-
BASED INSTABILITY TO DEVELOP BY THE AFTERNOON. THE WEAK WAVE SEEN
IN THE WATER VAPOR LOOP MAY MOVE CLOSE ENOUGH TO PROVIDE SOME WEAK
LIFT BUT ALL TOGETHER CONDITIONS REMAIN MARGINAL FOR WIDESPREAD
STORMS. FORECAST SOUNDINGS ACROSS THE AREA SHOW QUITE THE RANGE OF
SBCAPE VALUES RANGING FROM SUB 500 J/KG IN THE NAM AND TTU-WRF TO
ALMOST 2500 J/KG IN THE HRRR AND RAP. IF STORMS DO DEVELOP...COULD
ONCE AGAIN SEE A MARGINAL SEVERE WEATHER THREAT MAINLY IN THE FORM
OF DOWNBURSTS.
ALL THIS PUT TOGETHER MEANS THAT HIGH TEMPERATURES WERE UNDERCUT
ACROSS THE NORTHERN SOUTH PLAINS WHERE THE HEAVIEST RAINFALL FELL
LAST NIGHT/EARLY THIS MORNING AS SURFACE MOISTURE AND REMNANT CLOUD
COVER SHOULD HELP TO MODERATE TEMPERATURES SOME. THE REST OF THE
AREA SHOULD SEE TEMPERATURES A FEW DEGREES COOLER THAN YESTERDAY BUT
STILL IN THE MID TO UPPER 90S. CHANCE FOR PRECIP WILL INITIALLY BE
HIGHEST THIS MORNING...A LULL IN THE LATE MORNING EARLY AFTERNOON...
THEN PICKING UP AGAIN LATE THIS AFTERNOON FOR THE SOUTH PLAINS. THE
ROLLING PLAINS LOOKS TO BE TOO FAR TO THE EAST TO SEE MUCH IN THE
WAY OF PRECIP AS THE FRONT/OUTFLOW BOUNDARY IS HARD TO FIND AND ALL
MODELS KEEP THE EASTERN ONE THIRD OF THE FORECAST AREA DRY. ONLY
UNCERTAINTY IS HOW LONG POPS WILL GO PAST MIDNIGHT AS THE TTU-WRF
TRIES TO DEVELOP ANOTHER WEAK MESOSCALE CONVECTIVE COMPLEX AROUND
SUNSET BUT THEN DISSIPATES IT BY MIDNIGHT LOCAL TIME BEFORE IT MAKES
IT TO THE EDGE OF THE CAPROCK. A DECENT LOW-LEVEL JET IS FORECAST
TO DEVELOP OVERNIGHT WHICH MAY HELP TO KEEP CONVECTION GOING BUT IT
WILL VEER BETWEEN 06 AND 12Z FROM SOUTH TO SOUTHWEST...NOT GOOD FOR
MAINTENANCE OF ANY CONVECTION THAT DEVELOPS.
JORDAN
LONG TERM...
SEMI-ACTIVE PATTERN AT PRESENT LOOKS TO PERSIST AT LEAST ONE MORE
DAY BEFORE A SUBTROPICAL HIGH RE-EXERTS ITSELF SQUARELY ATOP THE
ROLLING PLAINS FROM THURSDAY AND LASTING THROUGH EARLY NEXT WEEK.
UNTIL THAT MONOTONOUS PATTERN IS REALIZED...A RESIDUAL LAYER OF
MOISTURE AND SLIGHTLY COOLER TEMPS ALOFT WILL PERSIST PARTICULARLY
ACROSS EASTERN NM AND OUR WESTERN ZONES ON WEDNESDAY. BROAD
SURFACE TROUGHING JUST WEST OF THE STATE LINE ALONG WITH WEAK
UPSLOPE FLOW SHOULD HELP TRIGGER SOME AFTN/EVNG STORMS...BUT POPS
ELSEWHERE ON WEDNESDAY WERE TRIMMED BELOW MENTION AS HEIGHT FIELDS
ARE PROGGED TO RISE ABOUT 20 METERS THROUGHOUT THE DAY WHICH
IMPLIES TOO MUCH SUBSIDENCE FOR PRECIP IN THIS OTHERWISE WEAKLY
FORCED PATTERN.
BY THURSDAY...LARGE SCALE SUBSIDENCE WILL TAKE GRASP AREA WIDE
WITH ONLY A FEW MORSELS OF PRECIP POSSIBLE ALONG THE WESTERN
PERIPHERY OF THE HIGH - BUT EVEN THESE ARE NOW SHAPING UP MORE
CONDITIONAL THAN EARLIER MODELS INDICATED SO WE HAVE REMOVED
MEASURABLE PRECIP MENTION ON THURSDAY ACROSS OUR WESTERN COUNTIES.
THEREAFTER...JUST MINOR DAILY OSCILLATIONS OF THE HIGH/S CENTER
ARE THE ONLY CHANGES EXPECTED WITH NEGLIGIBLE IMPACTS ON HIGH
TEMPS. CONSIDERING MODELS KEEP 500 MB MAX HEIGHTS AOB 596 DAM...
HIGHS SHOULD NOT PUSH TOO FAR ABOVE CLIMO DESPITE THE OBVIOUS
WARM BIAS STILL PLAGUING MOS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 64 91 66 92 / 30 20 20 10
TULIA 66 92 69 93 / 30 10 10 10
PLAINVIEW 68 91 70 92 / 30 10 10 0
LEVELLAND 68 93 71 93 / 30 20 20 10
LUBBOCK 72 94 72 95 / 30 20 10 0
DENVER CITY 69 94 70 93 / 30 20 20 10
BROWNFIELD 69 94 71 94 / 30 20 20 0
CHILDRESS 72 98 73 99 / 30 10 10 0
SPUR 70 94 73 94 / 20 10 10 0
ASPERMONT 72 98 75 99 / 10 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
51/01/
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
145 PM EDT TUE JUL 21 2015
.SYNOPSIS...
A COLD FRONT THAT EXTENDED FROM ONTARIO TO THE CENTRAL UNITED
STATES EARLY THIS MORNING WILL MOVE SOUTHEAST TODAY AND TONIGHT
AND WILL TRAIL FROM THE CAROLINA COAST INTO THE SOUTHERN PLAINS BY
WEDNESDAY MORNING. HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT AND
WILL COVER THE MID ATLANTIC REGION ON THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1255 PM EDT TUESDAY...
THERE HAS BEEN A SMALL UPSWING IN THE AMOUNT OF CONVECTION FIRING
ACROSS THE REGION. THERE IS NOW A GREATER CONCENTRATION OF SHOWERS
ACROSS THE WESTERN PORTION OF THE REGION. MOST OF THE ACTIVITY IS
VERY SMALL IN SIZE...AND NO LIGHTNING HAS OCCURRED YET. FAR
EASTERN PARTS OF THE AREA REMAIN THE REGION TO WATCH FOR DEEPER
CONVECTION ONCE IT BEGINS...GIVEN THIS REGION WAS NOT IMPACTED BY
THIS RAIN SHIELD FROM THIS MORNING...AND MOST OF THE DAY HAS HAD
AT LEAST SOME SUNSHINE REACHING THE GROUND. AM EXPECTING THE BEST
COVERAGE...AND STRONGEST ACTIVITY TO BE IN THIS EASTERN AREA BY
THE MID TO LATE AFTERNOON. ONCE WE REACH THIS EVENING...COVERAGE
WILL BE CONFINED TO MAINLY THE SOUTHEAST PART OF THE REGION...WITH
AN INCREASE IN THE NORTHWEST AS THE COLD FRONT MOVES INTO THE
AREA. NO MAJOR CHANGE TO THE FORECAST HIGH TEMPERATURES AS MOST
ARE ON TRACK TO BE WITHIN A DEGREE OR TWO OF CURRENTLY FORECAST
NUMBERS.
AS OF 1010 AM EDT TUESDAY...
CONVECTIVE CLUSTER FROM THIS MORNING HAS DISSIPATED INTO A PATCHY
AREA OF LIGHT RAIN...AND HAS EXITED THE NORTHEAST PART OF THE
FORECAST AREA. HEADING INTO THIS AFTERNOON...MUCH OF THE REGION
WILL BE RELATIVELY STABLE...BEING TEMPORARILY CAPPED FROM THE
EARLIER CONVECTION AND SLOW TO HEAT AT THE SURFACE TO DO PLENTY OF
REMAINING DEBRIS CLOUD COVER. LATER THIS AFTERNOON WITH THE
APPROACH AND ARRIVAL OF A COLD FRONT IS WHEN THE SHOWER AND
THUNDERSTORM ACTIVITY SHOULD REVAMP ITS COVERAGE. HOWEVER...THE
LATEST VERSION OF THE FORECAST WILL BE DOWNPLAYING THE CHANCE OF
PRECIPITATION A BIT AS COMPARED TO THE EARLIER NUMBERS THANKS TO
THE AFOREMENTIONED NEGATIVE INFLUENCES TO CONVECTION.
AS OF 400 AM EDT TUESDAY...
A SHORT WAVE CROSSING THE OHIO VALLEY WAS GENERATING CLUSTERS OF
SHOWERS AND THUNDERSTORMS FROM WEST VIRGINIA INTO NORTHERN
TENNESSEE. SHORT TERM GUIDANCE...INCLUDING THE LAST COUPLE RUNS OF
THE HRRR HAS THIS PRECIPITATION MOVING ACROSS THE WESTERN COUNTY
WARNING AREA BEFORE 8AM/12Z. A MAJORITY OF THESE SHOWERS AND
THUNDERSTORMS WILL IMPACT THE WESTERN AND NORTHERN COUNTY WARNING
AREA THIS MORNING AND ARE EXPECTED TO MOVE EAST BUT WEAKEN AS THEY
CROSS THE BLUE RIDGE.
A COLD FRONT TRAILED FROM ONTARIO TO CENTRAL MISSOURI EARLY THIS
MORNING. THIS FRONT WILL MOVE SOUTHEAST TODAY AND TONIGHT. SHOWERS
AND THUNDERSTORMS WILL DEVELOP ALONG THE FRONT THIS AFTERNOON
WHICH WILL RESULT IN ADDITIONAL THUNDERSTORMS IN THE FORECAST AREA
THIS AFTERNOON AND EVENING. HAVE USED THE TIMING OF THE GFS WHICH WAS
BRINGING THE FRONT THROUGH THE FORECAST AREA BEFORE MIDNIGHT...
SLIGHTLY FASTER THAN THE NAM GUIDANCE. SO INCREASED THE
PROBABILITY OF PRECIPITATION FOR MOST LOCATIONS TODAY...AND
REMOVED THE CHANCE OF RAIN LATE TONIGHT BEHIND THE FRONT. THREAT
FOR STORMS BECOMING SEVERE WILL BE LIMITED BY MODEST AMOUNTS OF
INSTABILITY AND SHEAR. BEST CHANCE IS IN THE PIEDMONT LATE THIS
AFTERNOON AND EVENING WHEN THE FRONT SHIFTS INTO THE LEE TROF.
WILL HAVE CLEARING BEHIND THE FRONT EAST OF THE BLUE RIDGE
OVERNIGHT...BUT UPSLOPE WINDS AND RESIDUAL LOW LEVEL MOISTURE WILL
HOLD CLOUDS IN THE WESTERN UPSLOPE AREAS THROUGH EARLY WEDNESDAY
MORNING.
STARTING OUT MILD THIS MORNING SO EVEN WITH THE CLOUD COVER AND
PRECIPITATION TEMPERATURES WILL RISE INTO THE 80S. STAYED CLOSE TO
BLEND OF MAV/MET GUIDANCE FOR MAXIMUM TEMPERATURES TODAY. HEAT
INDEX VALUES WILL BE AROUND 100 FOR A COUPLE HOURS IN THE PIEDMONT
THIS AFTERNOON...NOT HIGH ENOUGH OR LONG ENOUGH TO SUPPORT ANY
ADVISORY.
AIR MASS BEHIND THE FRONT IS SLIGHTLY COOLER WITH LOWS TONIGHT A
CATEGORY OR TWO BELOW TEMPERATURES THIS MORNING. THE MORE
SIGNIFICANT CHANGE IS SURFACE DEW POINTS DROPPING INTO THE UPPER
50S IN THE NORTHERN COUNTY WARNING AREA ALONG WITH PRECIPITABLE
WATER VALUES DROPPING BELOW ONE HALF INCH.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 310 AM EDT TUESDAY...
BROAD UPPER TROUGH CENTERED AROUND JAMES BAY EXTENDING ACROSS THE
EASTERN GREAT LAKES AND EASTERN CANADIAN WILL TRAVEL EAST DURING
THE PERIOD...AS AN UPPER RIDGE AMPLIFIES IN THE CENTRAL UNITED
STATES. THE SURFACE FRONTAL BOUNDARY WILL PUSH SOUTH OF OUR AREA
AND STALL...BUT SERVE AS A FOCUS FOR DIURNALLY DRIVEN CONVECTION.
DECREASED POPS WEDNESDAY...BUT STILL KEPT SOME ISOLATED TO WIDELY
SCATTERED POPS IN THE WEST WEDNESDAY AFTERNOON ACROSS THE HIGHER
TERRAIN. HIGH TEMPERATURES WEDNESDAY WILL VARY FROM THE THE UPPER
70S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. HELD ON
TO AN ISOLATED SHOWERS ACROSS SOUTHERN PORTIONS OF THE FORECAST
AREA ON WEDNESDAY NIGHT...AS A WAVE OF LOW PRESSURE DEVELOPS ALONG
THE STALLED FRONTAL ZONE WEDNESDAY NIGHT. LOW TEMPERATURES
WEDNESDAY NIGHT WILL RANGE FROM THE MID 50S IN THE MOUNTAINS TO
THE UPPER 60S IN THE PIEDMONT.
AN UPPER LEVEL DISTURBANCE WILL TRACK ALONG THE FRONT/BAROCLINIC
ZONE FROM WEST TO EAST THURSDAY. THERE IS THE POTENTIAL THAT THE
FRONT MAY LIFT NORTH AS WEAK WAVES OF LOW PRESSURE RIDE ALONG THE
BOUNDARY. MOISTURE WILL TRY AND SURGE BACK INTO THE PIEDMONT AND
NORTHWEST NORTH CAROLINA MOUNTAINS TO SOME DEGREE. THE PLACEMENT OF
THE LOW CENTER LOOKED A LITTLE FURTHER SOUTH AND EAST ON THIS MODEL
RUN. HOWEVER...GIVEN TIME OF YEAR AND DIFFERENTIAL HEATING...ALLOWED
FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAINLY ACROSS
THE PIEDMONT. AT ANY RATE...THE THREAT FOR SIGNIFICANT OR WIDESPREAD
CONVECTION AND SEVERE STORMS WILL REMAIN VERY LOW. HIGHS ON THURSDAY
WILL CLIMB INTO THE UPPER 70S IN THE WEST TO THE THE UPPER 80S IN
THE EAST. AS HIGH PRESSURE NUDGES IN FROM THE NORTHWEST...DRIER AIR
PUSHES ACROSS THE AREA THURSDAY NIGHT. LOW TEMPERATURES THURSDAY
NIGHT WILL DROP INTO THE MID 50S IN THE MOUNTAINS TO THE NEAR 70
DEGREES IN THE PIEDMONT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 350 PM EDT MONDAY...
THE BROAD NORTHEAST U.S./SOUTHEAST CANADIAN UPPER TROUGH WILL
CONTINUE TO SHIFT SLOWLY EAST THROUGH THE PERIOD. A STRONG
SUBTROPICAL RIDGE ANCHORED ACROSS TEXAS...WILL AMPLIFY INTO THE
GREAT LAKES...WITH A NOSE OF 850MB TEMPS EXCEEDING +20C
ACCOMPANYING IT. OUR REGION WILL LARGELY REMAIN UNDER NORTHWEST
FLOW ALOFT THROUGH THE PERIOD. MOST MODELS TAKE THE REMNANT
FRONTAL BOUNDARY FROM MID-WEEK AND THE ASSOCIATED WEAKNESS IN THE
UPPER-LEVELS SOUTHWARD INTO THE SOUTHEAST STATES...WHERE IT
APPEARS DESTINED TO CUTOFF AND LINGER IN THE EASTERN
GULF/FL/WESTERN ATLANTIC REGION. AS IT LINGERS IN THIS REGION INTO
NEXT WEEK...IT WILL NEED TO BE CAREFULLY MONITORED FOR ANY
POTENTIAL TROPICAL CHARACTERISTICS. GIVEN THE
AMPLIFYING/STRENGTHENING NW FLOW ALOFT...WE SHOULD SEE THE FRONTAL
BOUNDARY/BAROCLINIC ZONE PUSHED FAR ENOUGH SOUTH TO SHUT OFF THE
CONVECTION SATURDAY...OUTSIDE ISOLATED MOUNTAIN SHOWERS. BY
SUNDAY...A SHORT WAVE AND ASSOCIATED WEAK FRONT MOVES INTO THE
REGION FROM THE NORTHWEST...WHICH SHOULD INCREASE THE CHANCE FOR
SHOWERS/STORMS. THIS FEATURE MOVES EAST OF THE REGION MONDAY AS
THE UPPER RIDGE CONTINUES TO BUILD INTO THE REGION FROM THE WEST.
500MB HEIGHTS ARE SLATED TO RISE ABOVE 590DM AND 850MB TEMPS WILL
BEGIN TO CREEP ABOVE +20C ONCE AGAIN...ESPECIALLY IN THE WEST.
CONVECTION LOOKS TO BE MINIMAL PAST SUNDAY AT THIS POINT.
TEMPERATURES APPEAR DESTINED TO RETURN TO ABOVE NORMAL LEVELS BY
THE WEEKEND.
A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE
WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS
THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE
NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES
TO REACH THE REGION.
850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C
ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP
INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU
MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP
BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY
BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS
BY THE WEEKEND.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 140 PM EDT TUESDAY...
ONLY LIGHT REFLECTIVITY ON THE SCOPE EARLY THIS AFTERNOON. PIEDMONT
TAF SITES...INCLUDING KROA...CURRENTLY SITTING AT VFR WHILE
KBCB/KBLF/KLWB REMAIN IN MVFR CATEGORY DUE TO LOW CIG. EXPECT AT
WORST MVFR CONDITIONS OVER THE NEXT FEW HOURS AS LIGHT PRECIPITATION
CONTINUES TO PUSH THROUGH THE WESTERN PORTIONS OF OUR FORECAST AREA
AHEAD OF THE COLD FRONT.
MAIN SOURCE OF UNCERTAINTY LIES AROUND THE TIMING AND STRENGTH OF
THE FRONTAL PASSAGE. DUE TO REMNANT CLOUDCOVER FROM A DECAYING MCS
THAT PUSHED INTO THE FORECAST AREA EARLIER THIS MORNING...ISOLATED
TO SCATTERED SHOWERS ARE EXPECTED FOR OUR WESTERN MOST TAF
LOCATIONS. THUNDERSTORMS ARE STILL POSSIBLE IN THE EAST WHERE
INSTABILITY WILL BE GREATEST. NO PREVAILING SHOWERS OR STORMS ARE
IN THE FORECAST FOR ANY OF THE TAF SITES...HOWEVER...THIS MAY
NEED AMENDING LATER THIS AFTERNOON BASED ON FUTURE
RADAR/SATELLITE DATA.
THE GFS IS ONE OF THE FASTER MODEL SOLUTIONS...BRINGING THE FRONT
THROUGH THE AREA THIS EVENING...ALMOST CLEARING PRECIP BY 00Z. WENT
A LITTLE SLOWER WITH THE TIMING OF PRECIP CONCLUSION AND WIND SHIFT
FROM OUT OF THE NNW. HIGHER CONFIDENCE OF MORE IFR TO MVFR CIGS ON
THE WESTERN SLOPES OF THE MOUNTAINS OVERNIGHT...BEFORE CLEARING OUT
AN UPPER-DECK BY 14Z TOMORROW.
LOW CONFIDENCE ON THE FOG FORMATION TOMORROW MORNING...AS ONCE AGAIN
IT WILL BE HIGHLY DEPENDENT ON PRECIP...CLOUDCOVER...AND ARRIVAL OF
DRY AIR. INCLUDING BR/FG AT LWB...WITH ONLY BR FORMATION AT BLF/BCB.
THIS MAY NEED AMENDING BY THE 00Z/06Z FCST TIME.
EXTENDED AVIATION DISCUSSION...
THE COLD FRONT WILL ADVANCE SOUTH OF THE FORECAST AREA FOR WEDNESDAY
AND THURSDAY...BUT THEN BUCKLES NORTHWARD ON FRIDAY. SO FOR NOW WILL
EXPECT OVERALL VFR CONDITIONS OUTSIDE PATCHY FOG WEDNESDAY AND
THURSDAY MORNING IN THE BCB/BLF/LWB AREA PENDING HOW DRY THE AIR
GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS POSSIBLE FRIDAY
AND SATURDAY IN THE MOUNTAINS...OVERALL...NOT SEEING MUCH QPF OVER
THE NEXT 7-10 DAYS...WHICH SHOULD HELP TO KEEP VFR LEVELS PREVALENT
THROUGH THE PERIOD.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...KK
LONG TERM...RAB
AVIATION...DS/JM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1259 PM EDT TUE JUL 21 2015
.SYNOPSIS...
A COLD FRONT THAT EXTENDED FROM ONTARIO TO THE CENTRAL UNITED
STATES EARLY THIS MORNING WILL MOVE SOUTHEAST TODAY AND TONIGHT
AND WILL TRAIL FROM THE CAROLINA COAST INTO THE SOUTHERN PLAINS BY
WEDNESDAY MORNING. HIGH PRESSURE WILL FOLLOW BEHIND THE FRONT AND
WILL COVER THE MID ATLANTIC REGION ON THURSDAY AND FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1255 PM EDT TUESDAY...
THERE HAS BEEN A SMALL UPSWING IN THE AMOUNT OF CONVECTION FIRING
ACROSS THE REGION. THERE IS NOW A GREATER CONCENTRATION OF SHOWERS
ACROSS THE WESTERN PORTION OF THE REGION. MOST OF THE ACTIVITY IS
VERY SMALL IN SIZE...AND NO LIGHTNING HAS OCCURRED YET. FAR
EASTERN PARTS OF THE AREA REMAIN THE REGION TO WATCH FOR DEEPER
CONVECTION ONCE IT BEGINS...GIVEN THIS REGION WAS NOT IMPACTED BY
THIS RAIN SHIELD FROM THIS MORNING...AND MOST OF THE DAY HAS HAD
AT LEAST SOME SUNSHINE REACHING THE GROUND. AM EXPECTING THE BEST
COVERAGE...AND STRONGEST ACTIVITY TO BE IN THIS EASTERN AREA BY
THE MID TO LATE AFTERNOON. ONCE WE REACH THIS EVENING...COVERAGE
WILL BE CONFINED TO MAINLY THE SOUTHEAST PART OF THE REGION...WITH
AN INCREASE IN THE NORTHWEST AS THE COLD FRONT MOVES INTO THE
AREA. NO MAJOR CHANGE TO THE FORECAST HIGH TEMPERATURES AS MOST
ARE ON TRACK TO BE WITHIN A DEGREE OR TWO OF CURRENTLY FORECAST
NUMBERS.
AS OF 1010 AM EDT TUESDAY...
CONVECTIVE CLUSTER FROM THIS MORNING HAS DISSIPATED INTO A PATCHY
AREA OF LIGHT RAIN...AND HAS EXITED THE NORTHEAST PART OF THE
FORECAST AREA. HEADING INTO THIS AFTERNOON...MUCH OF THE REGION
WILL BE RELATIVELY STABLE...BEING TEMPORARILY CAPPED FROM THE
EARLIER CONVECTION AND SLOW TO HEAT AT THE SURFACE TO DO PLENTY OF
REMAINING DEBRIS CLOUD COVER. LATER THIS AFTERNOON WITH THE
APPROACH AND ARRIVAL OF A COLD FRONT IS WHEN THE SHOWER AND
THUNDERSTORM ACTIVITY SHOULD REVAMP ITS COVERAGE. HOWEVER...THE
LATEST VERSION OF THE FORECAST WILL BE DOWNPLAYING THE CHANCE OF
PRECIPITATION A BIT AS COMPARED TO THE EARLIER NUMBERS THANKS TO
THE AFOREMENTIONED NEGATIVE INFLUENCES TO CONVECTION.
AS OF 400 AM EDT TUESDAY...
A SHORT WAVE CROSSING THE OHIO VALLEY WAS GENERATING CLUSTERS OF
SHOWERS AND THUNDERSTORMS FROM WEST VIRGINIA INTO NORTHERN
TENNESSEE. SHORT TERM GUIDANCE...INCLUDING THE LAST COUPLE RUNS OF
THE HRRR HAS THIS PRECIPITATION MOVING ACROSS THE WESTERN COUNTY
WARNING AREA BEFORE 8AM/12Z. A MAJORITY OF THESE SHOWERS AND
THUNDERSTORMS WILL IMPACT THE WESTERN AND NORTHERN COUNTY WARNING
AREA THIS MORNING AND ARE EXPECTED TO MOVE EAST BUT WEAKEN AS THEY
CROSS THE BLUE RIDGE.
A COLD FRONT TRAILED FROM ONTARIO TO CENTRAL MISSOURI EARLY THIS
MORNING. THIS FRONT WILL MOVE SOUTHEAST TODAY AND TONIGHT. SHOWERS
AND THUNDERSTORMS WILL DEVELOP ALONG THE FRONT THIS AFTERNOON
WHICH WILL RESULT IN ADDITIONAL THUNDERSTORMS IN THE FORECAST AREA
THIS AFTERNOON AND EVENING. HAVE USED THE TIMING OF THE GFS WHICH WAS
BRINGING THE FRONT THROUGH THE FORECAST AREA BEFORE MIDNIGHT...
SLIGHTLY FASTER THAN THE NAM GUIDANCE. SO INCREASED THE
PROBABILITY OF PRECIPITATION FOR MOST LOCATIONS TODAY...AND
REMOVED THE CHANCE OF RAIN LATE TONIGHT BEHIND THE FRONT. THREAT
FOR STORMS BECOMING SEVERE WILL BE LIMITED BY MODEST AMOUNTS OF
INSTABILITY AND SHEAR. BEST CHANCE IS IN THE PIEDMONT LATE THIS
AFTERNOON AND EVENING WHEN THE FRONT SHIFTS INTO THE LEE TROF.
WILL HAVE CLEARING BEHIND THE FRONT EAST OF THE BLUE RIDGE
OVERNIGHT...BUT UPSLOPE WINDS AND RESIDUAL LOW LEVEL MOISTURE WILL
HOLD CLOUDS IN THE WESTERN UPSLOPE AREAS THROUGH EARLY WEDNESDAY
MORNING.
STARTING OUT MILD THIS MORNING SO EVEN WITH THE CLOUD COVER AND
PRECIPITATION TEMPERATURES WILL RISE INTO THE 80S. STAYED CLOSE TO
BLEND OF MAV/MET GUIDANCE FOR MAXIMUM TEMPERATURES TODAY. HEAT
INDEX VALUES WILL BE AROUND 100 FOR A COUPLE HOURS IN THE PIEDMONT
THIS AFTERNOON...NOT HIGH ENOUGH OR LONG ENOUGH TO SUPPORT ANY
ADVISORY.
AIR MASS BEHIND THE FRONT IS SLIGHTLY COOLER WITH LOWS TONIGHT A
CATEGORY OR TWO BELOW TEMPERATURES THIS MORNING. THE MORE
SIGNIFICANT CHANGE IS SURFACE DEW POINTS DROPPING INTO THE UPPER
50S IN THE NORTHERN COUNTY WARNING AREA ALONG WITH PRECIPITABLE
WATER VALUES DROPPING BELOW ONE HALF INCH.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 310 AM EDT TUESDAY...
BROAD UPPER TROUGH CENTERED AROUND JAMES BAY EXTENDING ACROSS THE
EASTERN GREAT LAKES AND EASTERN CANADIAN WILL TRAVEL EAST DURING
THE PERIOD...AS AN UPPER RIDGE AMPLIFIES IN THE CENTRAL UNITED
STATES. THE SURFACE FRONTAL BOUNDARY WILL PUSH SOUTH OF OUR AREA
AND STALL...BUT SERVE AS A FOCUS FOR DIURNALLY DRIVEN CONVECTION.
DECREASED POPS WEDNESDAY...BUT STILL KEPT SOME ISOLATED TO WIDELY
SCATTERED POPS IN THE WEST WEDNESDAY AFTERNOON ACROSS THE HIGHER
TERRAIN. HIGH TEMPERATURES WEDNESDAY WILL VARY FROM THE THE UPPER
70S IN THE MOUNTAINS TO AROUND 90 DEGREES IN THE PIEDMONT. HELD ON
TO AN ISOLATED SHOWERS ACROSS SOUTHERN PORTIONS OF THE FORECAST
AREA ON WEDNESDAY NIGHT...AS A WAVE OF LOW PRESSURE DEVELOPS ALONG
THE STALLED FRONTAL ZONE WEDNESDAY NIGHT. LOW TEMPERATURES
WEDNESDAY NIGHT WILL RANGE FROM THE MID 50S IN THE MOUNTAINS TO
THE UPPER 60S IN THE PIEDMONT.
AN UPPER LEVEL DISTURBANCE WILL TRACK ALONG THE FRONT/BAROCLINIC
ZONE FROM WEST TO EAST THURSDAY. THERE IS THE POTENTIAL THAT THE
FRONT MAY LIFT NORTH AS WEAK WAVES OF LOW PRESSURE RIDE ALONG THE
BOUNDARY. MOISTURE WILL TRY AND SURGE BACK INTO THE PIEDMONT AND
NORTHWEST NORTH CAROLINA MOUNTAINS TO SOME DEGREE. THE PLACEMENT OF
THE LOW CENTER LOOKED A LITTLE FURTHER SOUTH AND EAST ON THIS MODEL
RUN. HOWEVER...GIVEN TIME OF YEAR AND DIFFERENTIAL HEATING...ALLOWED
FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS MAINLY ACROSS
THE PIEDMONT. AT ANY RATE...THE THREAT FOR SIGNIFICANT OR WIDESPREAD
CONVECTION AND SEVERE STORMS WILL REMAIN VERY LOW. HIGHS ON THURSDAY
WILL CLIMB INTO THE UPPER 70S IN THE WEST TO THE THE UPPER 80S IN
THE EAST. AS HIGH PRESSURE NUDGES IN FROM THE NORTHWEST...DRIER AIR
PUSHES ACROSS THE AREA THURSDAY NIGHT. LOW TEMPERATURES THURSDAY
NIGHT WILL DROP INTO THE MID 50S IN THE MOUNTAINS TO THE NEAR 70
DEGREES IN THE PIEDMONT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 350 PM EDT MONDAY...
THE BROAD NORTHEAST U.S./SOUTHEAST CANADIAN UPPER TROUGH WILL
CONTINUE TO SHIFT SLOWLY EAST THROUGH THE PERIOD. A STRONG
SUBTROPICAL RIDGE ANCHORED ACROSS TEXAS...WILL AMPLIFY INTO THE
GREAT LAKES...WITH A NOSE OF 850MB TEMPS EXCEEDING +20C
ACCOMPANYING IT. OUR REGION WILL LARGELY REMAIN UNDER NORTHWEST
FLOW ALOFT THROUGH THE PERIOD. MOST MODELS TAKE THE REMNANT
FRONTAL BOUNDARY FROM MID-WEEK AND THE ASSOCIATED WEAKNESS IN THE
UPPER-LEVELS SOUTHWARD INTO THE SOUTHEAST STATES...WHERE IT
APPEARS DESTINED TO CUTOFF AND LINGER IN THE EASTERN
GULF/FL/WESTERN ATLANTIC REGION. AS IT LINGERS IN THIS REGION INTO
NEXT WEEK...IT WILL NEED TO BE CAREFULLY MONITORED FOR ANY
POTENTIAL TROPICAL CHARACTERISTICS. GIVEN THE
AMPLIFYING/STRENGTHENING NW FLOW ALOFT...WE SHOULD SEE THE FRONTAL
BOUNDARY/BAROCLINIC ZONE PUSHED FAR ENOUGH SOUTH TO SHUT OFF THE
CONVECTION SATURDAY...OUTSIDE ISOLATED MOUNTAIN SHOWERS. BY
SUNDAY...A SHORT WAVE AND ASSOCIATED WEAK FRONT MOVES INTO THE
REGION FROM THE NORTHWEST...WHICH SHOULD INCREASE THE CHANCE FOR
SHOWERS/STORMS. THIS FEATURE MOVES EAST OF THE REGION MONDAY AS
THE UPPER RIDGE CONTINUES TO BUILD INTO THE REGION FROM THE WEST.
500MB HEIGHTS ARE SLATED TO RISE ABOVE 590DM AND 850MB TEMPS WILL
BEGIN TO CREEP ABOVE +20C ONCE AGAIN...ESPECIALLY IN THE WEST.
CONVECTION LOOKS TO BE MINIMAL PAST SUNDAY AT THIS POINT.
TEMPERATURES APPEAR DESTINED TO RETURN TO ABOVE NORMAL LEVELS BY
THE WEEKEND.
A WEAK UPPER LOW CUTS OFF ACROSS THE SOUTHEAST STATES BY THE
WEEKEND AND STALLS. BY SAT-SUN...THE UPPER RIDGE AMPLIFIES ACROSS
THE CENTRAL U.S. AND WE QUICKLY RETURN BACK TO A MORE UNSTABLE
NORTHWEST FLOW AND THE POTENTIAL FOR UPSTREAM CONVECTIVE COMPLEXES
TO REACH THE REGION.
850MB TEMPS DROP BELOW +20C THU-SAT...CREEPING BACK ABOVE +20C
ACROSS MUCH OF THE CWA BY THE END OF NEXT WEEKEND. DEWPOINTS DROP
INTO THE 50S ACROSS THE NORTHERN PART OF THE CWA BY THU
MORNING...WHICH SHOULD BE QUITE REFRESHING...BEFORE THEY CREEP
BACK UP INTO THE 60S TO LOW 70S BY THE WEEKEND. NEAR TO SLIGHTLY
BELOW NORMAL TEMPS THU-FRI...SHOULD RETURN TO ABOVE NORMAL LEVELS
BY THE WEEKEND.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 740 AM EDT TUESDAY...
CLUSTER OF LIGHT TO MODERATE SHOWERS OVER KLWB WILL BE EAST OF THE
AIRPORT BY THE START OF THE 12Z TAF FORECAST PERIOD. IFR TO MVFR
CEILINGS IN THE MOUNTAINS WILL BE SLOWER TO IMPROVE BUT MEDIUMCONFIDENCE
CONDITIONS WILL BE VFR BY 14Z.
ADDITIONAL SHOWERS AND THUNDERSTORMS WILL FORM THIS AFTERNOON
ALONG A COLD FRONT. A FEW OF THESE STORMS WILL BECOME STRONG AND
MAY PRODUCE GUSTY WINDS. USING THE TIMING OF THE GFS AND BRINING
THE FRONT THROUGH THE AREA THIS EVENING WHICH WILL TURN SURFACE
TO THE NORTHWEST. HIGH CONFIDENCE OF MORE IFR TO MVFR CLOUDS ON
THE WESTERN SLOPES OF THE MOUNTAINS OVERNIGHT.
EXTENDED AVIATION DISCUSSION...
THE COLD FRONT WILL ADVANCE SOUTH OF THE FORECAST AREA FOR
WEDNESDAY AND THURSDAY...BUT THEN BUCKLES NORTHWARD ON FRIDAY. SO
FOR NOW WILL EXPECT OVERALL VFR CONDITIONS OUTSIDE PATCHY FOG
WEDNESDAY AND THURSDAY MORNING IN THE BCB/LWB AREA PENDING HOW
DRY THE AIR GETS BEHIND THIS FRONT. THEN MORE SHOWERS AND STORMS
POSSIBLE FRIDAY AND SATURDAY IN THE MOUNTAINS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...KK
LONG TERM...RAB
AVIATION...AMS/NF
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT TUE JUL 21 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 257 PM CDT TUE JUL 21 2015
PRETTY QUIET WEATHER COMING UP OVER THE NEXT COUPLE OF DAYS. THE
SURFACE RIDGE...CURRENTLY CENTERED OVER NORTHWEST IOWA AND
SOUTHWEST MINNESOTA...WILL DRIFT EAST AND BECOME CENTERED OVER THE
GREAT LAKES REGION WEDNESDAY. THIS HIGH WILL THEN ESSENTIALLY
REMAIN STATIONARY THROUGH THURSDAY WHICH WILL CONTINUE TO PROVIDE
THE REGION WITH DRY CONDITIONS. WITH THE HIGH MOVING OVER THE
AREA...THERE IS SOME SMALL POTENTIAL FOR VALLEY FOG TONIGHT.
HOWEVER...THE 21.12Z NAM FORECAST SOUNDINGS ARE NOT THAT FAVORABLE
FOR FOG FORMATION. IT SUGGESTS IT WILL COME CLOSE TO SATURATION AT
THE SURFACE BUT THEN QUICKLY DRY OUT ABOVE THAT AS THE WEST TO
NORTHWEST WINDS JUST ABOVE THE SURFACE INCREASE TO AROUND 10
KNOTS. THE 21.17Z RAP IS EVEN LESS ENTHUSED AS IT SHOWS A 3C
TEMP/DEW POINT SPREAD AT 11Z. PREVIOUS FORECAST HAD INTRODUCED
SOME PATCHY FOG FOR LATE TONIGHT INTO WEDNESDAY MORNING AND WILL
MAINTAIN THIS FOR NOW. OTHERWISE...LOOK FOR TEMPERATURES TO SLOWLY
WARM WITH HIGHS IN THE LOWER TO MIDDLE 80S EXPECTED BY THURSDAY
AND LOWS OF 60 TO 65 BY THURSDAY NIGHT.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 257 PM CDT TUE JUL 21 2015
THE NEXT CHANCE FOR SOME RAIN WILL COME IN THE FRIDAY TO SATURDAY
TIME FRAME. THE MODELS AGREE THAT A SHORT WAVE TROUGH WILL COME
OUT OF THE WESTERN CONUS LONG WAVE TROUGH AND MOVE EAST INTO THE
RIDGE AXIS. SOME DIFFERENCES BETWEEN THE 21.12Z ECMWF...GFS AND
GEM ON HOW MUCH THIS WAVE WILL BE ABLE TO FLATTEN THE RIDGE. THE
GFS IS THE MOST AGGRESSIVE WITH THIS SYSTEM WHICH RESULTS IN THE
FLATTEST RIDGE AND THE STRONGEST WAVE COMING ACROSS THE REGION.
THE WAVE THE GFS BRINGS THROUGH HAS THE LOOK OF POSSIBLY BEING
FROM CONVECTIVE FEEDBACK. THE GEM IS THE WEAKEST WITH THE SYSTEM
AND KEEPS MORE RIDGING OVER THE AREA WHILE THE ECMWF IS IN BETWEEN
THESE TWO SOLUTIONS BUT LOOKS MORE LIKE THE GEM THAN THE GFS. THE
ECMWF HAS STARTED TO BACK OFF FROM THE 21.00Z RUN ON THE AMOUNT
AND COVERAGE OF RAIN FOR FRIDAY NIGHT WITH THIS SYSTEM AS THE COLD
FRONT COMES THROUGH. BASED ON THIS TREND...CAPPED THE MODEL
CONSENSUS GRIDS AT A 60 PERCENT CHANCE OF RAIN...WHICH MAINTAINS
PRETTY GOOD CONTINUITY WITH THE PREVIOUS FORECAST. IF THE GFS IS
CORRECT...THERE COULD BE SOME SEVERE POTENTIAL WITH THIS SYSTEM AS
IT SHOWS AROUND 2000 J/KG OF ML CAPE FRIDAY EVENING DROPPING TO
AROUND 1000 J/KG OVERNIGHT. THE 0-6KM SHEAR LOOKS PRETTY WEAK IN
THE EVENING BUT COULD INCREASE TO 35 TO 40 KNOTS OVERNIGHT.
AFTER THIS SYSTEM...ANOTHER QUICK MOVING SHORT WAVE TROUGH COULD
COME ACROSS SATURDAY NIGHT WITH SOME ADDITIONAL RAIN AND THEN THE
NEXT SHORT WAVE TROUGH TO POTENTIALLY COME THROUGH RIDGE COULD BE
MONDAY NIGHT INTO TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 600 PM CDT TUE JUL 21 2015
A SFC HIGH WILL BE THE MAIN WEATHER FEATURE FOR THE REGION INTO
THU...ALTHOUGH A FEW MID/LEVEL CLOUDS COULD SPILL ACROSS THE UPPER
LEVEL RIDGE ON WED. VFR CONDITIONS SHOULD PREVAIL.
THAT SAID...WITH THE HIGH OVERHEAD AND A LIGHT SFC WIND VALLEY FOG
HAS TO BE CONSIDERED. KLSE BUFKIT RAP/HRRR SOUNDINGS SUGGEST A DEEP
LIGHT WIND FIELD IN EXCESS OF 8 KFT...BUT KEEP A HEALTHY T/TD
SPREAD. NAM12 SIMILAR BUT BRINGS SFC T/TD TOGETHER BY 12Z. EXPECT
SOME RIVER VALLEY FOG...BUT HOW WIDESPREAD IN THE MISSISSIPPI IS IN
QUESTION.
23Z KLSE OB HAS A +27 T/TD SPREAD WITH 9 KTS OF WIND...BOTH NOT
FAVORABLE FOR FG AT KLSE...BUT NOT NECESSARILY PRECLUDING THE
POTENTIAL COMPLETELY EITHER. GOING TO STICK WITH BCFG FOR NOW.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
257 PM CDT TUE JUL 21 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 257 PM CDT TUE JUL 21 2015
PRETTY QUIET WEATHER COMING UP OVER THE NEXT COUPLE OF DAYS. THE
SURFACE RIDGE...CURRENTLY CENTERED OVER NORTHWEST IOWA AND
SOUTHWEST MINNESOTA...WILL DRIFT EAST AND BECOME CENTERED OVER THE
GREAT LAKES REGION WEDNESDAY. THIS HIGH WILL THEN ESSENTIALLY
REMAIN STATIONARY THROUGH THURSDAY WHICH WILL CONTINUE TO PROVIDE
THE REGION WITH DRY CONDITIONS. WITH THE HIGH MOVING OVER THE
AREA...THERE IS SOME SMALL POTENTIAL FOR VALLEY FOG TONIGHT.
HOWEVER...THE 21.12Z NAM FORECAST SOUNDINGS ARE NOT THAT FAVORABLE
FOR FOG FORMATION. IT SUGGESTS IT WILL COME CLOSE TO SATURATION AT
THE SURFACE BUT THEN QUICKLY DRY OUT ABOVE THAT AS THE WEST TO
NORTHWEST WINDS JUST ABOVE THE SURFACE INCREASE TO AROUND 10
KNOTS. THE 21.17Z RAP IS EVEN LESS ENTHUSED AS IT SHOWS A 3C
TEMP/DEW POINT SPREAD AT 11Z. PREVIOUS FORECAST HAD INTRODUCED
SOME PATCHY FOG FOR LATE TONIGHT INTO WEDNESDAY MORNING AND WILL
MAINTAIN THIS FOR NOW. OTHERWISE...LOOK FOR TEMPERATURES TO SLOWLY
WARM WITH HIGHS IN THE LOWER TO MIDDLE 80S EXPECTED BY THURSDAY
AND LOWS OF 60 TO 65 BY THURSDAY NIGHT.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 257 PM CDT TUE JUL 21 2015
THE NEXT CHANCE FOR SOME RAIN WILL COME IN THE FRIDAY TO SATURDAY
TIME FRAME. THE MODELS AGREE THAT A SHORT WAVE TROUGH WILL COME
OUT OF THE WESTERN CONUS LONG WAVE TROUGH AND MOVE EAST INTO THE
RIDGE AXIS. SOME DIFFERENCES BETWEEN THE 21.12Z ECMWF...GFS AND
GEM ON HOW MUCH THIS WAVE WILL BE ABLE TO FLATTEN THE RIDGE. THE
GFS IS THE MOST AGGRESSIVE WITH THIS SYSTEM WHICH RESULTS IN THE
FLATTEST RIDGE AND THE STRONGEST WAVE COMING ACROSS THE REGION.
THE WAVE THE GFS BRINGS THROUGH HAS THE LOOK OF POSSIBLY BEING
FROM CONVECTIVE FEEDBACK. THE GEM IS THE WEAKEST WITH THE SYSTEM
AND KEEPS MORE RIDGING OVER THE AREA WHILE THE ECMWF IS IN BETWEEN
THESE TWO SOLUTIONS BUT LOOKS MORE LIKE THE GEM THAN THE GFS. THE
ECMWF HAS STARTED TO BACK OFF FROM THE 21.00Z RUN ON THE AMOUNT
AND COVERAGE OF RAIN FOR FRIDAY NIGHT WITH THIS SYSTEM AS THE COLD
FRONT COMES THROUGH. BASED ON THIS TREND...CAPPED THE MODEL
CONSENSUS GRIDS AT A 60 PERCENT CHANCE OF RAIN...WHICH MAINTAINS
PRETTY GOOD CONTINUITY WITH THE PREVIOUS FORECAST. IF THE GFS IS
CORRECT...THERE COULD BE SOME SEVERE POTENTIAL WITH THIS SYSTEM AS
IT SHOWS AROUND 2000 J/KG OF ML CAPE FRIDAY EVENING DROPPING TO
AROUND 1000 J/KG OVERNIGHT. THE 0-6KM SHEAR LOOKS PRETTY WEAK IN
THE EVENING BUT COULD INCREASE TO 35 TO 40 KNOTS OVERNIGHT.
AFTER THIS SYSTEM...ANOTHER QUICK MOVING SHORT WAVE TROUGH COULD
COME ACROSS SATURDAY NIGHT WITH SOME ADDITIONAL RAIN AND THEN THE
NEXT SHORT WAVE TROUGH TO POTENTIALLY COME THROUGH RIDGE COULD BE
MONDAY NIGHT INTO TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 116 PM CDT TUE JUL 21 2015
VFR CONDITIONS EXPECTED THROUGH WEDNESDAY MORNING AS HIGH PRESSURE
DOMINATES THE UPPER MISSISSIPPI RIVER VALLEY REGION. THERE WILL
LIKELY BE SOME RIVER VALLEY FOG...BUT CONFIDENCE IS RELATIVELY LOW
FOR FOG AT KLSE. INCLUDED BCFG/FEW003 FOR NOW IN THE 09-14Z TIME
FRAME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
102 PM MDT TUE JUL 21 2015
.UPDATE...
ISSUED AT 1005 AM MDT TUE JUL 21 2015
LIGHT SHOWERS CONTINUE ACROSS MUCH OF SOUTHEAST WYOMING AND
NEBRASKA PANHANDLE THIS MORNING. CLOUD COVER AND SHOWER ACTIVITY
WILL LIKELY DECREASE THE AFTERNOON THUNDERSTORM COVERAGE AND
STRENGTH OF THUNDERSTORMS. WATERVAPOR IMAGERY IS SHOWING A POCKET
OF DRIER AIR ASSOCIATED WITH A SHORTWAVE JUST SOUTH OF THE WYOMING
BORDER. THIS WAVE WILL LIFT NORTHEAST INTO SOUTHEAST WYOMING THIS
AFTERNOON AND WILL BE THE MAIN FOCUS AREA FOR THUNDERSTORMS. AT
THIS POINT NOT DO NOT SEE ANY CHANCES FOR SEVERE THUNDERSTORMS
TODAY...IN FACT THUNDERSTORMS WILL GENERALLY BE WEAK TODAY.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 330 AM MDT TUE JUL 21 2015
500 MB ANALYSIS SHOWS A WEAK SHORTWAVE ACROSS SOUTHWESTERN WYOMING
WITH WIDESPREAD MID LEVEL CLOUDS AND SCATTERED SHOWERS TO THE
EAST OF THE LARAMIE RANGE. THE WEAK UPPER LEVEL DISTURBANCE IS
PROGGED TO PASS OVERHEAD THROUGH THE DAY. THE HRRR AND GFS/NAM
SHOW SHOWERS INCREASING IN COVERAGE ACROSS THE PLAINS THROUGH THE
MORNING...AND ESPECIALLY ACROSS THE NEBRASKA PANHANDLE.
INSTABILITY INCREASES BY AROUND 18Z WITH CAPE VALUES OF 750 TO
1250 J/KG THROUGH THE AFTN. WILL KEEP THE HIGH POPS (40 TO 60
PERCENT) GOING THROUGH THE LATE AFTN ACROSS THE PLAINS AS THE
SHORTWAVE INTERACTS WITH PLENTIFUL SUBTROPICAL MOISTURE ALONG WITH
DECENT LOW LEVEL MOISTURE. MAIN CONCERN WITH THE CONVECTION WILL
BE HEAVY RAIN WITH PW VALUES ABOVE NORMAL (ABOVE 1 INCH). MAY ALSO
BE SOME SMALL HAIL WITH BULK SHEAR AROUND 30 KT...HOWEVER CONFIDENCE
IS NOT HIGH ENOUGH TO INCLUDE IN FCST. TEMPS WILL BE COOLER TODAY
WITH THE WIDESPREAD CLOUD COVER. THE RAIN WILL TAPER OFF BY THE
LATE EVENING AS SUBSIDENCE KICKS IN BEHIND THE SHORTWAVE.
CHANCES FOR STORMS WILL BE LESS ON WEDNESDAY AS HEIGHTS ALOFT BEGIN
TO RISE. HOWEVER...700 TO 500 MB FLOW IS STILL SOUTHWESTERLY WITH
MODEST SUBTROPICAL MOISTURE STREAMING INTO WYOMING AND PW VALUES
OF 0.75 TO 1 INCH. COULD SEE SCATTERED AFTN STORMS DEVELOP OVER
MUCH OF SOUTHEAST WYOMING WITH THE MAIN THREAT BEING BRIEF HEAVY
RAIN. INSTABILITY IS QUITE A BIT LESS THAN TODAY SO SMALL HAIL IS
NOT MUCH OF A THREAT. HIGH TEMPS WILL RISE 5 TO 10 DEGREES. MUCH
MORE DRYING IS STILL PROGGED FOR THURSDAY AS THE SUBTROPICAL
MOISTURE PLUME SHIFTS OUT OF SOUTHERN WYOMING. SOUTHWEST WINDS
WILL BE BREEZY TO THE WEST OF THE LARAMIE RANGE AS A SFC TROUGH
DEVELOPS OVER WESTERN SOUTH DAKOTA.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 AM MDT TUE JUL 21 2015
THE 00Z MEDIUM RANGE MODELS ARE IN AGREEMENT DEPICTING A LARGE
SCALE UPPER RIDGE OVER THE NATION`S MIDSECTION...WITH THE MORE
ACTIVE WESTERLIES CONFINED ACROSS THE NORTHERN TIER THROUGH THE
WEEKEND. THE FLOW ALOFT WILL BE WEST TO SOUTHWEST...WITH MOST OF THE
SUBTROPICAL MOISTURE TO THE SOUTH AND WEST OF THE REGION. THE
ECMWF...AND TO A LESSER EXTENT THE GFS...HINT AT SOME MOISTURE
TRYING TO SNEAK NORTHWARD ACROSS THE HIGH PLAINS SATURDAY AND SUNDAY
FOR ISOLATED AFTERNOON/EVENING CONVECTION. IT WILL BE WARM FRIDAY
THROUGH SUNDAY WITH HIGHS FROM THE MID 80S TO LOW 90S. A SURFACE
TROUGH MOVES INTO THE HIGH PLAINS MONDAY...WITH A WEAK SHORTWAVE
PASSING OVERHEAD. THE ECMWF QPF LOOKS OVERDONE COMPARED TO THE
GFS...WITH LOW POPS FOR THE SOUTHEAST WYOMING MOUNTAINS. HIGH
TEMPERATURES MONDAY WILL BE A FEW DEGREES COOLER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1255 PM MDT TUE JUL 21 2015
RADAR DATA FROM KCYS SHOWS A BROAD AREA OF MODERATE RAIN FALLING
ACROSS THE CENTRAL AND SOUTHERN NEBRASKA PANHANDLE...EXTENDING
SOUTHWEST TOWARDS CYS. EXPECT THIS TREND TO CONTINUE THRU THE
EARLY EVENING HOURS AS A DISTURBANCES LIFTS ACROSS THE REGION.
EXPECT CONDITIONS IN GENERAL TO REMAIN VFR...THOUGH WILL SEE
PERIODIC BOUTS WITH MVFR CONDITIONS IN BOTH CIGS/VSBYS. HAVE
INCLUDED TEMPO GROUPS AT CYS AND ALL NEBRASKA PANHANDLE LOCATIONS
AS COVERAGE WILL BE SUFFICIENT. THIS CONVECTIVE ACTIVITY WILL
DISSIPATE 03-06Z. MAY SEE SOME PATCHY FOG DEVELOP IN THE VICINITY
OF THE NORTH PLATTE RIVER VALLEY...WHICH WOULD MAINLY IMPACT BFF
10-14Z.
&&
.FIRE WEATHER...
ISSUED AT 330 AM MDT TUE JUL 21 2015
MINIMAL FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. SCATTERED
SHOWERS AND THUNDERSTORMS WILL OCCUR TODAY FOR AREAS TO THE EAST
OF THE LARAMIE RANGE. A DRIER AIR MASS WILL MOVE INTO THE REGION
WEDNESDAY AND ESPECIALLY THURSDAY. THURSDAY AFTERNOON...MINIMUM
HUMIDITY VALUES WILL DROP TO 15 TO 25 PERCENT OVER LOWER ELEVATIONS
AND SOUTHWEST WINDS WILL BE BREEZY TO THE WEST OF THE LARAMIE RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...ZF
LONG TERM...MAJ
AVIATION...CAH
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1011 AM MDT TUE JUL 21 2015
.UPDATE...
ISSUED AT 1005 AM MDT TUE JUL 21 2015
LIGHT SHOWERS CONTINUE ACROSS MUCH OF SOUTHEAST WYOMING AND
NEBRASKA PANHANDLE THIS MORNING. CLOUD COVER AND SHOWER ACTIVITY
WILL LIKELY DECREASE THE AFTERNOON THUNDERSTORM COVERAGE AND
STRENGTH OF THUNDERSTORMS. WATERVAPOR IMAGERY IS SHOWING A POCKET
OF DRIER AIR ASSOCIATED WITH A SHORTWAVE JUST SOUTH OF THE WYOMING
BORDER. THIS WAVE WILL LIFT NORTHEAST INTO SOUTHEAST WYOMING THIS
AFTERNOON AND WILL BE THE MAIN FOCUS AREA FOR THUNDERSTORMS. AT
THIS POINT NOT DO NOT SEE ANY CHANCES FOR SEVERE THUNDERSTORMS
TODAY...IN FACT THUNDERSTORMS WILL GENERALLY BE WEAK TODAY.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 330 AM MDT TUE JUL 21 2015
500 MB ANALYSIS SHOWS A WEAK SHORTWAVE ACROSS SOUTHWESTERN WYOMING
WITH WIDESPREAD MID LEVEL CLOUDS AND SCATTERED SHOWERS TO THE
EAST OF THE LARAMIE RANGE. THE WEAK UPPER LEVEL DISTURBANCE IS
PROGGED TO PASS OVERHEAD THROUGH THE DAY. THE HRRR AND GFS/NAM
SHOW SHOWERS INCREASING IN COVERAGE ACROSS THE PLAINS THROUGH THE
MORNING...AND ESPECIALLY ACROSS THE NEBRASKA PANHANDLE.
INSTABILITY INCREASES BY AROUND 18Z WITH CAPE VALUES OF 750 TO
1250 J/KG THROUGH THE AFTN. WILL KEEP THE HIGH POPS (40 TO 60
PERCENT) GOING THROUGH THE LATE AFTN ACROSS THE PLAINS AS THE
SHORTWAVE INTERACTS WITH PLENTIFUL SUBTROPICAL MOISTURE ALONG WITH
DECENT LOW LEVEL MOISTURE. MAIN CONCERN WITH THE CONVECTION WILL
BE HEAVY RAIN WITH PW VALUES ABOVE NORMAL (ABOVE 1 INCH). MAY ALSO
BE SOME SMALL HAIL WITH BULK SHEAR AROUND 30 KT...HOWEVER CONFIDENCE
IS NOT HIGH ENOUGH TO INCLUDE IN FCST. TEMPS WILL BE COOLER TODAY
WITH THE WIDESPREAD CLOUD COVER. THE RAIN WILL TAPER OFF BY THE
LATE EVENING AS SUBSIDENCE KICKS IN BEHIND THE SHORTWAVE.
CHANCES FOR STORMS WILL BE LESS ON WEDNESDAY AS HEIGHTS ALOFT BEGIN
TO RISE. HOWEVER...700 TO 500 MB FLOW IS STILL SOUTHWESTERLY WITH
MODEST SUBTROPICAL MOISTURE STREAMING INTO WYOMING AND PW VALUES
OF 0.75 TO 1 INCH. COULD SEE SCATTERED AFTN STORMS DEVELOP OVER
MUCH OF SOUTHEAST WYOMING WITH THE MAIN THREAT BEING BRIEF HEAVY
RAIN. INSTABILITY IS QUITE A BIT LESS THAN TODAY SO SMALL HAIL IS
NOT MUCH OF A THREAT. HIGH TEMPS WILL RISE 5 TO 10 DEGREES. MUCH
MORE DRYING IS STILL PROGGED FOR THURSDAY AS THE SUBTROPICAL
MOISTURE PLUME SHIFTS OUT OF SOUTHERN WYOMING. SOUTHWEST WINDS
WILL BE BREEZY TO THE WEST OF THE LARAMIE RANGE AS A SFC TROUGH
DEVELOPS OVER WESTERN SOUTH DAKOTA.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 AM MDT TUE JUL 21 2015
THE 00Z MEDIUM RANGE MODELS ARE IN AGREEMENT DEPICTING A LARGE
SCALE UPPER RIDGE OVER THE NATION`S MIDSECTION...WITH THE MORE
ACTIVE WESTERLIES CONFINED ACROSS THE NORTHERN TIER THROUGH THE
WEEKEND. THE FLOW ALOFT WILL BE WEST TO SOUTHWEST...WITH MOST OF THE
SUBTROPICAL MOISTURE TO THE SOUTH AND WEST OF THE REGION. THE
ECMWF...AND TO A LESSER EXTENT THE GFS...HINT AT SOME MOISTURE
TRYING TO SNEAK NORTHWARD ACROSS THE HIGH PLAINS SATURDAY AND SUNDAY
FOR ISOLATED AFTERNOON/EVENING CONVECTION. IT WILL BE WARM FRIDAY
THROUGH SUNDAY WITH HIGHS FROM THE MID 80S TO LOW 90S. A SURFACE
TROUGH MOVES INTO THE HIGH PLAINS MONDAY...WITH A WEAK SHORTWAVE
PASSING OVERHEAD. THE ECMWF QPF LOOKS OVERDONE COMPARED TO THE
GFS...WITH LOW POPS FOR THE SOUTHEAST WYOMING MOUNTAINS. HIGH
TEMPERATURES MONDAY WILL BE A FEW DEGREES COOLER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 330 AM MDT TUE JUL 21 2015
VFR CEILINGS WILL PREVAIL FOR THE MOST PART THROUGH TONIGHT.
THERE WILL BE BRIEF PERIODS OF MVFR CEILINGS AND VISIBILITY
WITH SHRA AND TSRA AS WELL AS GUSTY WINDS...ESPECIALLY THIS
AFTERNOON AND EARLY EVENING. THE LATEST NAM/SREF MODELS ARE
INDICATING MVFR TO IFR CEILINGS DEVELOPING ACROSS MUCH OF
WESTERN NEBRASKA LATE TONIGHT...AND WILL BE TRENDING THAT
DIRECTION WITH THIS TAF PACKAGE.
&&
.FIRE WEATHER...
ISSUED AT 330 AM MDT TUE JUL 21 2015
MINIMAL FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. SCATTERED
SHOWERS AND THUNDERSTORMS WILL OCCUR TODAY FOR AREAS TO THE EAST
OF THE LARAMIE RANGE. A DRIER AIR MASS WILL MOVE INTO THE REGION
WEDNESDAY AND ESPECIALLY THURSDAY. THURSDAY AFTERNOON...MINIMUM
HUMIDITY VALUES WILL DROP TO 15 TO 25 PERCENT OVER LOWER ELEVATIONS
AND SOUTHWEST WINDS WILL BE BREEZY TO THE WEST OF THE LARAMIE RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...ZF
LONG TERM...MAJ
AVIATION...MAJ
FIRE WEATHER...ZF