Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/13/13
AREA FORECAST DISCUSSION
NWS PUEBLO CO
352 PM MDT WED SEP 11 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 352 PM MDT WED SEP 11 2013
.TONIGHT...NEXT BATCH OF CONVECTION HAS DEVELOPED OVER SOUTHERN
PUEBLO COUNTY AND IS MOVING NORTHWARD. LATEST HRRR SUGGESTS THIS
CONVECTION WILL WEAKEN DURING THE NEXT HOURLY...BUT HRRR PERFORMANCE
HAS NOT BEEN STELLAR TODAY. MODELS HAVE BEEN DOING A BETTER JOB WITH
THE CONVECTION ON THE EASTERN PLAINS...AND THERE IS A CONSENSUS OF
MOST OF THE PRECIPITATION MOVING TO THE NORTHEAST DURING THE
EVENING. OVER THE CONTINENTAL DIVIDE REGION....SOME STORMS HAVE
FINALLY DEVELOPED AS WATER VAPOR SHOWS A DISTURBANCE MOVING INTO
CENTRAL COLORADO. DECIDED TO MAINTAIN MOSTLY HIGH SCATTERED POPS
DURING THE NIGHT. SUSPECT THE DISTURBANCE OVER CENTRAL COLORADO
WILL MOVE ACROSS THE REGION THIS EVENING..WHICH WILL DEVELOP SOME
SHOWERS THIS EVENING.
.THURSDAY...THE THREAT FOR LOCALLY HEAVY RAIN CONTINUES. DISTURBANCE
MOVING INTO THE MIDWEST WILL STRENGTHEN HIGH PRESSURE OVER THE
NORTHERN PLAINS. THE STRENGTHENING ANTICYCLONE WILL PUSH A COLD
FRONT THROUGH THE PLAINS...INCREASING THE EASTERLY FLOW AND MOISTURE
FLUX INTO THE REGION. THE PLUME OF MIDDLE AND UPPER MOISTURE WILL
ALSO CONTINUE OVER THE REGION EAST OF THE UPPER LOW OVER THE GREAT
BASIN. MODELS CONTINUE TO GENERATE WIDESPREAD SIGNIFICANT
PRECIPITATION OVER THE REGION THURSDAY..ESPECIALLY OVER THE EASTERN
MOUNTAINS AND PLAINS. SUSPECT A WEAK DISTURBANCE IS NORTHEASTWARD
INTO COLORADO. ISSUED A FLASH FLOOD WATCH FOR THURSDAY FOR THE
WALDO CANYON AND BLACK FOREST BURN SCARS. THERE WAS SOME MINOR
FLOODING OVER WALDO CANYON BURN SCAR TODAY AND THE STORMS ON
THURSDAY COULD BE STRONGER. FURTHER WEST...ANTICIPATE MORE COVERAGE
OF STORMS THAN WEDNESDAY AS THE AMOUNT OF MIDDLE AND UPPER LEVEL
MOISTURE INCREASES. --PGW--
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 352 PM MDT WED SEP 11 2013
...HEAVY RAIN POSSIBLE THURSDAY NIGHT...
THURSDAY NIGHT-FRIDAY...MODELS CONTINUE TO INDICATE A VERY WET
PERIOD AS WEAKENING UPPER LOW ACROSS WESTERN UTAH IS SLOWLY KICKED
OUT INTO THE NORTHERN ROCKIES BY EASTERN PACIFIC ENERGY DROPPING OUT
OF WESTERN BC AND INTO THE NORTHERN TIER OF STATES. THIS ENHANCES
MOIST LOW LEVEL UPSLOPE FLOW ACROSS THE EASTERN MTS THURSDAY NIGHT
AND ALONG WITH INCREASED UVV FROM ASSOCIATED JET TRANSLATING ACROSS
THE ROCKIES AND THE ABUNDANT ATMOSPHERIC MOISTURE STILL IN
PLACE...WILL SUPPORT THE LOCALLY HEAVY RAINFALL ACROSS THE AREA
THURSDAY NIGHT. LATEST MODELS CONTINUE TO PEG EASTERN COLORADO AND
IN PARTICULAR THE PIKES PEAK REGION...WHERE LOW LEVEL UPSLOPE WILL
BE MAXIMIZED...FOR HEAVY RAIN THURSDAY NIGHT AND FRIDAY WITH HPC
DAY 2 QPF TOTAL INDICATING 1-2 INCHES ACROSS SOUTHEASTERN COLORADO
WITH A BULLSEYE OF 1.76 INCHES ACROSS THE PALMER DVD AND 1.96
INCHES OVER KIOWA COUNTY. WITH THAT SAID...HAVE KEPT HIGH POPS
INTACT ACROSS THE AREA THURSDAY NIGHT AND FRIDAY...WITH AN
INCREASED CONCERN FOR FLASH FLOODING THURSDAY NIGHT...ESPECIALLY
FOR THE WALDO CANYON AND BLACK FORECAST BURN SCARS.
FRIDAY NIGHT-SUNDAY NIGHT...FLOW ALOFT BECOMES WEAK WESTERLY WITH
MONSOONAL PLUME DECREASING THROUGH SUNDAY...AS THE NORTHERN TIER
SYSTEM CONTINUES TO DROP SOUTH AND EAST ACROSS THE UPPER MIDWEST.
STILL ENOUGH MOISTURE IN PLACE FOR SCATTERED SHOWERS AND STORMS
ACROSS THE AREA SATURDAY...WITH LOCALLY HEAVY RAINFALL STILL A
THREAT DUE TO THE WEAK STEERING FLOW ALOFT. PASSING NORTHERN TIER
SYSTEM SENDS A WEAK BACKDOOR COLD FRONT ACROSS THE EASTERN PLAINS
SATURDAY NIGHT WITH MOIST EASTERLY UPSLOPE FLOW HELPING TO
INCREASE PRECIPITATION CHANCES ACROSS THE EASTERN MTS AND
IMMEDIATE ADJACENT PLAINS SUNDAY AFTERNOON AND EVENING.
MONDAY-WEDNESDAY...MODELS CONTINUE TO INDICATE A WARMING AND DRYING
TREND FOR EARLY NEXT WEEK AS A BROAD UPPER TROUGH SETS UP ACROSS THE
PAC NW COAST...KEEPING MODERATE WEST TO SOUTHWEST FLOW ALOFT ACROSS
THE REGION. THIS WILL ALLOW FOR TEMPERATURES TO WARM BACK TO
GENERALLY ABOVE SEASONAL AVERAGES. LATEST EC INDICATES ANOTHER
POSSIBLE BACKDOOR COLD FRONT MOVING ACROSS THE EASTERN PLAINS ON
WEDNESDAY WITH THE GFS BRINGING THE FRONT ACROSS THURSDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 352 PM MDT WED SEP 11 2013
KCOS AND KPUB...NEXT BATCH OF STORMS IS MOVING NORTHWARD AND WILL
AFFECT KCOS AND KPUB DURING THE LATER AFTERNOON AND EARLY EVENING.
ANTICIPATE MVFR CEILINGS OVERNIGHT WITH ABUNDANT LOW LEVEL MOISTURE
REMAINING. SHOWERS AND THUNDERSTORMS WILL LIKELY DEVELOP BY LATE
MORNING AS A DISTURBANCE MOVES INTO THE REGION. ATMOSPHERE REMAINS
MOIST AND THERE IS THE THREAT FOR HEAVY RAIN.
KALS...SOME SHOWERS MAY CONTINUE THROUGH MID EVENING. ANTICIPATE
MVFR CEILINGS OVERNIGHT WITH LOW LEVEL MOISTURE REMAINING IN THE SAN
LUIS VALLEY. SHOWERS AND THUNDERSTORMS WILL DEVELOP BY LATE MORNING
AS A DISTURBANCE MOVES INTO THE REGION. --PGW--
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 9 PM MDT THIS EVENING FOR COZ081-084-085.
FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY
EVENING FOR COZ081-084-085.
&&
$$
SHORT TERM...PGW
LONG TERM...MW
AVIATION...PGW
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
309 PM MDT WED SEP 11 2013
.SHORT TERM...(TONIGHT THROUGH THURSDAY NIGHT)
ISSUED AT 309 PM MDT WED SEP 11 2013
CURRENT WATER VAPOR IMAGERY SHOWS PLENTY OF DRY AIR MOVING INTO
THE CWA THIS AFTERNOON BUT THIS DRY AIR RESIDES ABOVE 500MB OR
ABOUT 18K FEET. BELOW THAT LEVEL...RESIDUAL MOISTURE EXISTS. THE
LOW PRESSURE TO OUR WEST CONTINUES TO REMAIN FAIRLY STATIONARY AS
SHORT WAVES ROTATE AROUND IT. THE LAST WAVE IS NOW CAUSING
WIDESPREAD SHOWERS AND SOME ISOLATED THUNDERSTORMS MAINLY NORTH OF
I-70. THE STORMS THAT HAVE FORMED HAVE BEEN FAIRLY SLOW MOVERS
ALLOWING HEAVY RAIN TO FALL ON ALREADY SATURATED GROUND...THUS
SOME FLOOD ADVISORIES HAVE BEEN ISSUED. VIS SATELLITE SHOWS PLENTY
OF CONVECTION AROUND THE AREA OF LOW PRESSURE OVER AZ AND WRN UT
BUT NOT MUCH IN THE DRY SLOT THAT HAS FORMED THIS AFTN. HRRR AND
RAP BOTH INDICATING NOT MUCH DEVELOPMENT IN THE 4 CORNERS REGION
EVEN WITH SOME WEAK UPPER LEVEL SUPPORT INCREASING TOWARD THE
EVENING HOURS. WILL KEEP ISOLD TO SCTD SHOWERS AND STORMS IN
FORECAST THOUGH AS ANY WEAK WAVE MAY ALLOW SOME PRECIP TO KICK
OFF. IN THAT REGARD...FLASH FLOOD WATCH WILL ALSO CONTINUE THROUGH
9PM THIS EVENING. OVERNIGHT...EXPECT DRYING TO CONTINUE THOUGH A
STRAY SHOWER OR STORM IS POSSIBLE.
BY TOMORROW...THE LOW PRESSURE WILL HAVE MOVED SLIGHTLY NORTH WHILE
THE PLUME OF MOISTURE WILL HAVE SHIFTED EAST TO THE FRONT RANGE. A
DOWNTICK IN PRECIP IS EXPECTED THOUGH AGAIN...RESIDUAL MOISTURE IN
THE LOWER LEVELS WILL ALLOW SOME SCTD SHOWERS AND STORMS TO FORM.
EXPECT A MIX OF SUN AND CLOUDS WITH TEMPERATURES SLOWLY WARMING UP
AFTER THE LAST FEW MUCH COOLER THAN AVERAGE DAYS. NOT MUCH CHANGE
OVERNIGHT WITH A FEW SHOWERS CONTINUING AS THE LOW CONTINUES TO
SPIN OVER ERN NV/WRN UT.
&&
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 309 PM MDT WED SEP 11 2013
UPPER LEVEL TROUGH BEGINS TO PROPAGATE NORTH FRIDAY WITH THE
REMAINING SOUTH END OF THIS TROUGH FLATTENING OVERNIGHT INTO
SATURDAY. MIDRANGE MODELS AGREE ON 580 DM HEIGHT CONTOUR
DIMINISHING IN SIZE SATURDAY AS IT MOVES NORTH...DECREASING THE
FORCING NEEDED FOR STRATIFORM RAIN. AVAILABLE MOISTURE STILL
REMAINS...HINTING AT SCATTERED TO NUMEROUS SHOWER AND THUNDERSTORM
ACTIVITY THROUGHOUT THE WEEKEND BUT BEING MORE DIURNALLY DRIVEN. WITH
THE UPPER LEVEL JET PUSHING EAST AS THE UPPER LEVEL TROUGH MOVES
TO THE NORTH AND EAST...LACK OF DIVERGENCE ALOFT WILL LIKELY KEEP
SHOWERS AND THUNDERSTORMS FROM BEING WIDESPREAD EVEN WITH PWATS
STILL BETWEEN 0.8 AND 1.0 INCH.
SLIGHT DISCREPANCY BETWEEN THE GFS AND ECMWF BY SATURDAY NIGHT ON
THE LOCATION OF REMAINING TROUGH OVER THE GREAT BASIN DUE TO
TIMING OF AN UPPER LEVEL PACIFIC NORTHWEST LOW PRESSURE SYSTEM PUSHING
THE REMAINING ENERGY EASTWARD. THIS PACIFIC NW FEATURE MOVING EAST
ACROSS THE INTERMOUNTAIN WEST IS PROGGED TO TURN THE FLOW FAIRLY
ZONAL EARLY NEXT WEEK WITH DRIER AIR FROM THE WEST DECREASING THE
THREAT OF SHOWERS EARLY NEXT WEEK. OVERCAST SKIES ALL DAY LONG
SHOULD CEASE SUNDAY...WHICH WILL ALLOW A CHANGE TO SCATTERED CONVECTIVE
PRECIPITATION AND POTENTIALLY HEAVY RAIN IN SHORT AMOUNTS OF TIME.
COUPLE DIFFERENT RESULTS MIDWEEK ON TIMING AND IMPACTS FROM THIS
LARGE UPPER LEVEL TROUGH PUSHING INTO WESTERN US. DEPENDING ON THE
AMPLIFICATION OF THIS TROUGH...STRONG SOUTHWEST FLOW AHEAD OF A
MODERATE COLD FRONT MAY BE THE OVERRIDING FEATURE (12Z GFS
SOLUTION) OR THE VERY NORTHERN PARTS OF THE CWA WILL BE AFFECTED
BY A SMALLER SWATH OF TROUGHINESS (00Z ECMWF SOLUTION) WHILE MOST
OF THE CWA REMAINS RELATIVELY DRY AND SEASONABLY WARM. THE LATTER
SOLUTION IS FAVORED AT THIS TIME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 309 PM MDT WED SEP 11 2013
PLENTY OF CLOUDS...SHOWERS AND EVEN A FEW STORMS CAN BE FOUND
ACROSS THE REGION THIS AFTERNOON. EVEN SO...MAINLY VFR CONDITIONS
ARE BEING REPORTED ACROSS THE REGION. UNDER HEAVIER SHOWERS OCCNL
MVFR WILL OCCUR DUE TO MOSTLY LOW VIS WITH CIGS HOVERING AROUND 8K
TO 10K FEET. ALL TAF SITES HAVE SOME CHANCES TO SEE SOME
RAINSHOWERS OR LIGHT RAIN THROUGH THE EVENING HOURS. CONDITIONS
SHOULD IMPROVE AFTER 06Z THOUGH A FEW STRAY SHOWERS MAY PERSIST.
EXPECT SIMILAR CONDITIONS TOMORROW AFTER 18Z THOUGH COVERAGE
SHOULD BE SOMEWHAT LESS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FLASH FLOOD WATCH UNTIL 9 PM MDT THIS EVENING FOR COZ003-017-020.
UT...FLASH FLOOD WATCH UNTIL 9 PM MDT THIS EVENING FOR UTZ022-025-
027>029.
&&
$$
SHORT TERM...TGR
LONG TERM...JAM
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1159 AM MDT WED SEP 11 2013
.UPDATE...
ISSUED AT 925 AM MDT WED SEP 11 2013
FIRST BATCH OF LIGHT TO MODERATE SHOWERS OVER THE WALDO CANYON
BURN SCAR HAS FILLED STREAMS TO NEAR BANK FULL WITH SOME MINOR
FLOODING. WITH CONTINUED MOIST SOUTHERLY FLOW..DECIDED TO ISSUE A
FLASH FLOOD WATCH FOR THE WALDO CANYON AND BLACK FOREST BURN SCARS
AS ADDITIONAL SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AND
THIS EVENING.
RADAR SHOWS ONE SMALL ROTATION NEAR PUEBLO WEST. CONVECTION IS
DEVELOPING IN CENTRAL NEW MEXICO IN THE DRY SLOT...AND THIS
CONVECTION IS MOVING NORTH. SOME SHORT RANGE MODELS SUGGEST THESE
DISTURBANCES WILL BE STRONG ENOUGH DEVELOP SOME CONVECTION DURING
THE DAY. WALDO CANYON...IN PARTICULAR...APPEARS TO BE PRIMED FOR
SOME FLASH FLOODING IF HEAVIER RAIN PASSES OVER THE BURN SCAR.
--PGW--
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM MDT WED SEP 11 2013
THE UPR LOW IS EXPECTED TO BE CENTERED OVR THE SWRN CORNER OF UT
TODAY AND MAYBE MOVING SLIGHTLY NORTHWARD OVERNIGHT. MODELS ARE
SHOWING THE PLUME OF UPR MSTR SHIFTING EASTWARD THRU THE DAY AND
MAINLY BEING OVR THE EASTERN PORTIONS OF THE FORECAST AREA THIS
AFTERNOON...AND THEN BEING OVR THE FAR SERN PLAINS TONIGHT. WV
IMAGERY THIS MORNING SHOWING THE DRIER AIR WORKING ITS WAY INTO SWRN
CO. CURRENT RADAR LOOP SHOWING SOME ISOLD TO SCT ECHOES OVR THE SAN
LUIS VALLEY AND ALONG THE CONTDVD...WITH MORE PCPN OVR ERN AREAS AND
ADDITIONAL PCPN WORKING ITS WAY NORTHWARD FROM EASTERN NM.
IN GENERAL...THE HRRR SHOWS MAINLY ISOLD TO SCT POPS OVR THE SAN
LUIS VALLEY AND ALONG THE CONTDVD TODAY...WITH SCT OR HIGHER POPS
FROM THE ERN MTS TO THE ERN BORDER. THE WRF IS SIMILAR...ALTHOUGH IT
SHOWS HIGHER POPS OVR THE HIGHER TRRN IN THE MORNING HOURS...AND
THEN DECREASES THE PCPN CHANCES FOR THE AFTERNOON HOURS ALONG THE
CONTDVD AND SAN LUIS VALLEY AS THE DRIER AIR MOVES SPREADS OVR THE
AREA. THE NAM LOOKS OVERDONE AGAIN IN TERMS OF PCPN ACCUMULATION OVR
THE ERN MTS AND I-25 CORRIDOR FOR THE MORNING HOURS. BASED ON THE
WRF AND HRRR...PCPN OVR THE BURN SCARS TODAY SHOULD MOSTLY BE HIT
OR MISS AND NOT A PROLONGED EVENT...WL NOT ISSUE A FLASH FLOODING
HIGHLIGHT. HOWEVER THERE IS STILL THE CHANCE FOR LOCALLY HEAVY
RAIN AND THE STEERING FLOW TODAY IS EXPECTED TO BE ONLY AROUND
10-15 KTS OVR THE ERN MTS AND I-25 CORRIDOR...THUS FLASH FLOODING
CANNOT BE RULED OUT IF A STRONG SLOW MOVING STORM WERE TO MOVE OVR
AREA BURN SCARS. TEMPS OVR THE MTN PEAKS WL AGAIN BE COLD ENOUGH
FOR SOME SNOW TO OCCUR WITH SOME LIGHT ACCUMULATIONS.
FOR TONIGHT...ALL MODELS BRING DRIER CONDITIONS TO THE WESTERN HALF
OF THE FORECAST AREA...WITH SOME PCPN CONTINUING THRU THE NIGHT OVR
PORTIONS OF THE ERN PLAINS...ESPECIALLY THE FAR EASTERN AREAS AS A
COUPLE DISTURBANCES MOVES ACRS THAT AREA.
|
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 333 AM MDT WED SEP 11 2013
...WET THROUGH SUNDAY...
...DRYING OUT NEXT WEEK...
WET FORECAST REMAINS ON TRACK. WETTEST PERIOD STILL LOOKS TO BE THU
INTO FRI OF THIS WEEK...WHEN THE UPPER LOW IS MOVING THROUGH WRN UT
AND ERN NV...AND UPSLOPE WILL BE MAXIMIZED OVER THE ERN CO PLAINS.
THE ERN MTS...IN PARTICULAR THE ERN SLOPES...WILL LIKELY SEE THE
MOST QPF FROM THIS EVENT. THE NAM12 IS STILL PROGGING 2-4 INCHES OF
LIQUID FOR THE SRN FRONT RANGE AND PIKES PEAK REGION. PRETTY MUCH
THE ENTIRE AREA SHOULD SEE AN INCH OF RAIN OR BETTER OVER THE NEXT
SEVERAL DAYS. THE EXCEPTIONS COULD BE THE SAN LUIS VALLEY AND
PORTIONS OF THE ARKANSAS CANYON...WHICH COULD BE SHELTERED SOMEWHAT
WITH THESE SPOTS NOT AS CONDUCIVE TO UPSLOPE PRECIP. PORTIONS OF THE
FAR ERN PLAINS MIGHT ALSO SEE A BIT MORE SPOTTY TOTALS...SINCE THE
PRECIP THERE WILL BE A BIT MORE DEPENDENT ON WHERE CONVECTION SETS
UP. THE HIGHEST AMTS SHOULD BE OVR THE SRN SANGRES...RATON
MESA...AND PALMER DVD AND PIKES PEAK AREA. BURN SCARS IN THIS AREA
WILL BE THE MAIN CONCERN THROUGH THE WEEKEND.
TEMPS SHOULD STAY ON THE COOL SIDE...IN THE 60S AND 70S...THRU
FRIDAY...THEN REBOUND A BIT ON SATURDAY BEFORE ANOTHER FRONT MOVES
THROUGH ON SUN AND KNOCKS THINGS DOWN BELOW AVG AGAIN. POPS WILL
ALSO INCREASE AGAIN ON SUNDAY AS THE NEXT FRONT ARRIVES. SNOW LEVELS
REMAIN RELATIVELY HIGH THROUGH THE END OF THE WEEK...BUT AS
MENTIONED PREVIOUSLY THE HIGHEST ELEVS ABOVE 13K FT OR SO WILL SEE
SOME ACCUMULATING SNOW...PERHAPS QUITE A BIT FOR THE HIGHEST SUMMITS.
BY THE WEEKEND...SNOW LEVELS SHOULD DROP TO AS LOW AS 12K FEET...AND
THIS COULD GIVE THE ERN MTS A GOOD SHOT OF SNOW BY THE END OF THE
WEEKEND.
NEXT WEEK...THE PATTERN WILL BE DOMINATED BY A PROGRESSIVE UPPER LOW
MOVING OUT OF THE PACNW TUE-WED...AND THEN QUICKLY THROUGH THE NRN
ROCKIES ON THU. MOST OF OUR AREA WILL BE TO THE SOUTH OF THE MAIN
CIRCULATION...SO THE PLAINS WILL LIKELY STAY MAINLY DRY AND PERHAPS
A BIT BREEZY. THE MTS COULD SEE SOME OROGRAPHIC PRECIP...BUT MAY SEE
MORE WIND THAN RAIN/SNOW UNLESS THE LOW TRACKS A BIT FARTHER S THAN
THE MODELS CURRENTLY INDICATE. TEMPS SHOULD ALSO CLIMB BACK TO ABOVE
AVG FOR THE PLAINS...POSSIBLY REACHING THE MID 80S OR HIGHER BY
WED-THU. ROSE
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1151 AM MDT WED SEP 11 2013
CONVECTION OVER NORTHEAST NEW MEXICO IS MOVING NORTHWARD.
ANTICIPATE AN INCREASE IN PRECIPITATION CHANCES AT THE TAF SITES
FROM MID AFTERNOON AND INTO THE EVENING. BUFKIT SOUNDINGS SUGGEST
THERE MAY BE ENOUGH CAPE TO GET SOME THUNDERSTORMS AT THE TAF
SITES. EXPECT A DECREASE IN PRECIPITATION OVERNIGHT...WITH KPUB
AND KCOS CONTINUING TO HAVE MVFR CEILINGS WITH ABUNDANT LOW LEVEL
MOISTURE. BY MID MORNING THURSDAY...ANOTHER SHORTWAVE WILL
APPROACH FROM THE SOUTH WITH AND INCREASE IN PRECIPITATION BY LATE
MORNING. --PGW--
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 9 PM MDT THIS EVENING FOR COZ081-084-085.
&&
$$
UPDATE...PGW
SHORT TERM...28
LONG TERM...ROSE
AVIATION...PGW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
936 AM MDT WED SEP 11 2013
.UPDATE...
ISSUED AT 925 AM MDT WED SEP 11 2013
FIRST BATCH OF LIGHT TO MODERATE SHOWERS OVER THE WALDO CANYON
BURN SCAR HAS FILLED STREAMS TO NEAR BANK FULL WITH SOME MINOR
FLOODING. WITH CONTINUED MOIST SOUTHERLY FLOW..DECIDED TO ISSUE A
FLASH FLOOD WATCH FOR THE WALDO CANYON AND BLACK FOREST BURN SCARS
AS ADDITIONAL SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AND
THIS EVENING.
RADAR SHOWS ONE SMALL ROTATION NEAR PUEBLO WEST. CONVECTION IS
DEVELOPING IN CENTRAL NEW MEXICO IN THE DRY SLOT...AND THIS
CONVECTION IS MOVING NORTH. SOME SHORT RANGE MODELS SUGGEST THESE
DISTURBANCES WILL BE STRONG ENOUGH DEVELOP SOME CONVECTION DURING
THE DAY. WALDO CANYON...IN PARTICULAR...APPEARS TO BE PRIMED FOR
SOME FLASH FLOODING IF HEAVIER RAIN PASSES OVER THE BURN SCAR.
--PGW--
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM MDT WED SEP 11 2013
THE UPR LOW IS EXPECTED TO BE CENTERED OVR THE SWRN CORNER OF UT
TODAY AND MAYBE MOVING SLIGHTLY NORTHWARD OVERNIGHT. MODELS ARE
SHOWING THE PLUME OF UPR MSTR SHIFTING EASTWARD THRU THE DAY AND
MAINLY BEING OVR THE EASTERN PORTIONS OF THE FORECAST AREA THIS
AFTERNOON...AND THEN BEING OVR THE FAR SERN PLAINS TONIGHT. WV
IMAGERY THIS MORNING SHOWING THE DRIER AIR WORKING ITS WAY INTO SWRN
CO. CURRENT RADAR LOOP SHOWING SOME ISOLD TO SCT ECHOES OVR THE SAN
LUIS VALLEY AND ALONG THE CONTDVD...WITH MORE PCPN OVR ERN AREAS AND
ADDITIONAL PCPN WORKING ITS WAY NORTHWARD FROM EASTERN NM.
IN GENERAL...THE HRRR SHOWS MAINLY ISOLD TO SCT POPS OVR THE SAN
LUIS VALLEY AND ALONG THE CONTDVD TODAY...WITH SCT OR HIGHER POPS
FROM THE ERN MTS TO THE ERN BORDER. THE WRF IS SIMILAR...ALTHOUGH IT
SHOWS HIGHER POPS OVR THE HIGHER TRRN IN THE MORNING HOURS...AND
THEN DECREASES THE PCPN CHANCES FOR THE AFTERNOON HOURS ALONG THE
CONTDVD AND SAN LUIS VALLEY AS THE DRIER AIR MOVES SPREADS OVR THE
AREA. THE NAM LOOKS OVERDONE AGAIN IN TERMS OF PCPN ACCUMULATION OVR
THE ERN MTS AND I-25 CORRIDOR FOR THE MORNING HOURS. BASED ON THE
WRF AND HRRR...PCPN OVR THE BURN SCARS TODAY SHOULD MOSTLY BE HIT
OR MISS AND NOT A PROLONGED EVENT...WL NOT ISSUE A FLASH FLOODING
HIGHLIGHT. HOWEVER THERE IS STILL THE CHANCE FOR LOCALLY HEAVY
RAIN AND THE STEERING FLOW TODAY IS EXPECTED TO BE ONLY AROUND
10-15 KTS OVR THE ERN MTS AND I-25 CORRIDOR...THUS FLASH FLOODING
CANNOT BE RULED OUT IF A STRONG SLOW MOVING STORM WERE TO MOVE OVR
AREA BURN SCARS. TEMPS OVR THE MTN PEAKS WL AGAIN BE COLD ENOUGH
FOR SOME SNOW TO OCCUR WITH SOME LIGHT ACCUMULATIONS.
FOR TONIGHT...ALL MODELS BRING DRIER CONDITIONS TO THE WESTERN HALF
OF THE FORECAST AREA...WITH SOME PCPN CONTINUING THRU THE NIGHT OVR
PORTIONS OF THE ERN PLAINS...ESPECIALLY THE FAR EASTERN AREAS AS A
COUPLE DISTURBANCES MOVES ACRS THAT AREA.
|
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 333 AM MDT WED SEP 11 2013
...WET THROUGH SUNDAY...
...DRYING OUT NEXT WEEK...
WET FORECAST REMAINS ON TRACK. WETTEST PERIOD STILL LOOKS TO BE THU
INTO FRI OF THIS WEEK...WHEN THE UPPER LOW IS MOVING THROUGH WRN UT
AND ERN NV...AND UPSLOPE WILL BE MAXIMIZED OVER THE ERN CO PLAINS.
THE ERN MTS...IN PARTICULAR THE ERN SLOPES...WILL LIKELY SEE THE
MOST QPF FROM THIS EVENT. THE NAM12 IS STILL PROGGING 2-4 INCHES OF
LIQUID FOR THE SRN FRONT RANGE AND PIKES PEAK REGION. PRETTY MUCH
THE ENTIRE AREA SHOULD SEE AN INCH OF RAIN OR BETTER OVER THE NEXT
SEVERAL DAYS. THE EXCEPTIONS COULD BE THE SAN LUIS VALLEY AND
PORTIONS OF THE ARKANSAS CANYON...WHICH COULD BE SHELTERED SOMEWHAT
WITH THESE SPOTS NOT AS CONDUCIVE TO UPSLOPE PRECIP. PORTIONS OF THE
FAR ERN PLAINS MIGHT ALSO SEE A BIT MORE SPOTTY TOTALS...SINCE THE
PRECIP THERE WILL BE A BIT MORE DEPENDENT ON WHERE CONVECTION SETS
UP. THE HIGHEST AMTS SHOULD BE OVR THE SRN SANGRES...RATON
MESA...AND PALMER DVD AND PIKES PEAK AREA. BURN SCARS IN THIS AREA
WILL BE THE MAIN CONCERN THROUGH THE WEEKEND.
TEMPS SHOULD STAY ON THE COOL SIDE...IN THE 60S AND 70S...THRU
FRIDAY...THEN REBOUND A BIT ON SATURDAY BEFORE ANOTHER FRONT MOVES
THROUGH ON SUN AND KNOCKS THINGS DOWN BELOW AVG AGAIN. POPS WILL
ALSO INCREASE AGAIN ON SUNDAY AS THE NEXT FRONT ARRIVES. SNOW LEVELS
REMAIN RELATIVELY HIGH THROUGH THE END OF THE WEEK...BUT AS
MENTIONED PREVIOUSLY THE HIGHEST ELEVS ABOVE 13K FT OR SO WILL SEE
SOME ACCUMULATING SNOW...PERHAPS QUITE A BIT FOR THE HIGHEST SUMMITS.
BY THE WEEKEND...SNOW LEVELS SHOULD DROP TO AS LOW AS 12K FEET...AND
THIS COULD GIVE THE ERN MTS A GOOD SHOT OF SNOW BY THE END OF THE
WEEKEND.
NEXT WEEK...THE PATTERN WILL BE DOMINATED BY A PROGRESSIVE UPPER LOW
MOVING OUT OF THE PACNW TUE-WED...AND THEN QUICKLY THROUGH THE NRN
ROCKIES ON THU. MOST OF OUR AREA WILL BE TO THE SOUTH OF THE MAIN
CIRCULATION...SO THE PLAINS WILL LIKELY STAY MAINLY DRY AND PERHAPS
A BIT BREEZY. THE MTS COULD SEE SOME OROGRAPHIC PRECIP...BUT MAY SEE
MORE WIND THAN RAIN/SNOW UNLESS THE LOW TRACKS A BIT FARTHER S THAN
THE MODELS CURRENTLY INDICATE. TEMPS SHOULD ALSO CLIMB BACK TO ABOVE
AVG FOR THE PLAINS...POSSIBLY REACHING THE MID 80S OR HIGHER BY
WED-THU. ROSE
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 333 AM MDT WED SEP 11 2013
PCPN IS WORKING ITS WAY NORTHWARD THIS MORNING AND SHOULD BRING
SHOWERS TO KCOS AND KPUB...WITH THE POTENTIAL FOR MVFR CONDITIONS
AND MAYBE EVEN SOME BRIEF IFR CONDITIONS AT KCOS. KALS WL ALSO
HAVE SOME LIGHT RAIN IN THE VCNTY THRU THE MORNING. THIS AFTERNOON
AND EVENING THE THREE TERMINAL SITE COULD HAVE TSTMS IN THE AREA.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 9 PM MDT THIS EVENING FOR COZ081-084-085.
&&
$$
UPDATE...PGW
SHORT TERM...28
LONG TERM...ROSE
AVIATION...28
AREA FORECAST DISCUSSION
NWS PUEBLO CO
338 AM MDT WED SEP 11 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM MDT WED SEP 11 2013
THE UPR LOW IS EXPECTED TO BE CENTERED OVR THE SWRN CORNER OF UT
TODAY AND MAYBE MOVING SLIGHTLY NORTHWARD OVERNIGHT. MODELS ARE
SHOWING THE PLUME OF UPR MSTR SHIFTING EASTWARD THRU THE DAY AND
MAINLY BEING OVR THE EASTERN PORTIONS OF THE FORECAST AREA THIS
AFTERNOON...AND THEN BEING OVR THE FAR SERN PLAINS TONIGHT. WV
IMAGERY THIS MORNING SHOWING THE DRIER AIR WORKING ITS WAY INTO SWRN
CO. CURRENT RADAR LOOP SHOWING SOME ISOLD TO SCT ECHOES OVR THE SAN
LUIS VALLEY AND ALONG THE CONTDVD...WITH MORE PCPN OVR ERN AREAS AND
ADDITIONAL PCPN WORKING ITS WAY NORTHWARD FROM EASTERN NM.
IN GENERAL...THE HRRR SHOWS MAINLY ISOLD TO SCT POPS OVR THE SAN
LUIS VALLEY AND ALONG THE CONTDVD TODAY...WITH SCT OR HIGHER POPS
FROM THE ERN MTS TO THE ERN BORDER. THE WRF IS SIMILAR...ALTHOUGH IT
SHOWS HIGHER POPS OVR THE HIGHER TRRN IN THE MORNING HOURS...AND
THEN DECREASES THE PCPN CHANCES FOR THE AFTERNOON HOURS ALONG THE
CONTDVD AND SAN LUIS VALLEY AS THE DRIER AIR MOVES SPREADS OVR THE
AREA. THE NAM LOOKS OVERDONE AGAIN IN TERMS OF PCPN ACCUMULATION OVR
THE ERN MTS AND I-25 CORRIDOR FOR THE MORNING HOURS. BASED ON THE
WRF AND HRRR...PCPN OVR THE BURN SCARS TODAY SHOULD MOSTLY BE HIT
OR MISS AND NOT A PROLONGED EVENT...WL NOT ISSUE A FLASH FLOODING
HIGHLIGHT. HOWEVER THERE IS STILL THE CHANCE FOR LOCALLY HEAVY
RAIN AND THE STEERING FLOW TODAY IS EXPECTED TO BE ONLY AROUND
10-15 KTS OVR THE ERN MTS AND I-25 CORRIDOR...THUS FLASH FLOODING
CANNOT BE RULED OUT IF A STRONG SLOW MOVING STORM WERE TO MOVE OVR
AREA BURN SCARS. TEMPS OVR THE MTN PEAKS WL AGAIN BE COLD ENOUGH
FOR SOME SNOW TO OCCUR WITH SOME LIGHT ACCUMULATIONS.
FOR TONIGHT...ALL MODELS BRING DRIER CONDITIONS TO THE WESTERN HALF
OF THE FORECAST AREA...WITH SOME PCPN CONTINUING THRU THE NIGHT OVR
PORTIONS OF THE ERN PLAINS...ESPECIALLY THE FAR EASTERN AREAS AS A
COUPLE DISTURBANCES MOVES ACRS THAT AREA.
|
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 333 AM MDT WED SEP 11 2013
...WET THROUGH SUNDAY...
...DRYING OUT NEXT WEEK...
WET FORECAST REMAINS ON TRACK. WETTEST PERIOD STILL LOOKS TO BE THU
INTO FRI OF THIS WEEK...WHEN THE UPPER LOW IS MOVING THROUGH WRN UT
AND ERN NV...AND UPSLOPE WILL BE MAXIMIZED OVER THE ERN CO PLAINS.
THE ERN MTS...IN PARTICULAR THE ERN SLOPES...WILL LIKELY SEE THE
MOST QPF FROM THIS EVENT. THE NAM12 IS STILL PROGGING 2-4 INCHES OF
LIQUID FOR THE SRN FRONT RANGE AND PIKES PEAK REGION. PRETTY MUCH
THE ENTIRE AREA SHOULD SEE AN INCH OF RAIN OR BETTER OVER THE NEXT
SEVERAL DAYS. THE EXCEPTIONS COULD BE THE SAN LUIS VALLEY AND
PORTIONS OF THE ARKANSAS CANYON...WHICH COULD BE SHELTERED SOMEWHAT
WITH THESE SPOTS NOT AS CONDUCIVE TO UPSLOPE PRECIP. PORTIONS OF THE
FAR ERN PLAINS MIGHT ALSO SEE A BIT MORE SPOTTY TOTALS...SINCE THE
PRECIP THERE WILL BE A BIT MORE DEPENDENT ON WHERE CONVECTION SETS
UP. THE HIGHEST AMTS SHOULD BE OVR THE SRN SANGRES...RATON
MESA...AND PALMER DVD AND PIKES PEAK AREA. BURN SCARS IN THIS AREA
WILL BE THE MAIN CONCERN THROUGH THE WEEKEND.
TEMPS SHOULD STAY ON THE COOL SIDE...IN THE 60S AND 70S...THRU
FRIDAY...THEN REBOUND A BIT ON SATURDAY BEFORE ANOTHER FRONT MOVES
THROUGH ON SUN AND KNOCKS THINGS DOWN BELOW AVG AGAIN. POPS WILL
ALSO INCREASE AGAIN ON SUNDAY AS THE NEXT FRONT ARRIVES. SNOW LEVELS
REMAIN RELATIVELY HIGH THROUGH THE END OF THE WEEK...BUT AS
MENTIONED PREVIOUSLY THE HIGHEST ELEVS ABOVE 13K FT OR SO WILL SEE
SOME ACCUMULATING SNOW...PERHAPS QUITE A BIT FOR THE HIGHEST SUMMITS.
BY THE WEEKEND...SNOW LEVELS SHOULD DROP TO AS LOW AS 12K FEET...AND
THIS COULD GIVE THE ERN MTS A GOOD SHOT OF SNOW BY THE END OF THE
WEEKEND.
NEXT WEEK...THE PATTERN WILL BE DOMINATED BY A PROGRESSIVE UPPER LOW
MOVING OUT OF THE PACNW TUE-WED...AND THEN QUICKLY THROUGH THE NRN
ROCKIES ON THU. MOST OF OUR AREA WILL BE TO THE SOUTH OF THE MAIN
CIRCULATION...SO THE PLAINS WILL LIKELY STAY MAINLY DRY AND PERHAPS
A BIT BREEZY. THE MTS COULD SEE SOME OROGRAPHIC PRECIP...BUT MAY SEE
MORE WIND THAN RAIN/SNOW UNLESS THE LOW TRACKS A BIT FARTHER S THAN
THE MODELS CURRENTLY INDICATE. TEMPS SHOULD ALSO CLIMB BACK TO ABOVE
AVG FOR THE PLAINS...POSSIBLY REACHING THE MID 80S OR HIGHER BY
WED-THU. ROSE
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 333 AM MDT WED SEP 11 2013
PCPN IS WORKING ITS WAY NORTHWARD THIS MORNING AND SHOULD BRING
SHOWERS TO KCOS AND KPUB...WITH THE POTENTIAL FOR MVFR CONDITIONS
AND MAYBE EVEN SOME BRIEF IFR CONDITIONS AT KCOS. KALS WL ALSO
HAVE SOME LIGHT RAIN IN THE VCNTY THRU THE MORNING. THIS AFTERNOON
AND EVENING THE THREE TERMINAL SITE COULD HAVE TSTMS IN THE AREA.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...ROSE
AVIATION...28
AREA FORECAST DISCUSSION
NWS ALBANY NY
642 PM EDT WED SEP 11 2013
.SYNOPSIS...
OUR REGION WILL REMAIN IN A WARM AND HUMID AIR MASS TONIGHT INTO
THURSDAY...AS A FRONTAL BOUNDARY REMAINS POSITIONED OVER THE UPPER
GREAT LAKES AND SOUTHEAST CANADA. AS THIS FRONT APPROACHES ON
THURSDAY...SHOWERS AND THUNDERSTORMS WILL BECOME MORE WIDESPREAD
ACROSS THE AREA. THE COLD FRONT WILL PASS THROUGH LATE THURSDAY INTO
THURSDAY NIGHT...AND WILL USHER IN A DRIER AND MUCH COOLER AIR MASS
FOR FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 630 PM EDT...VERY MOIST LOW LEVELS REMAIN IN PLACE WITH
DEWPOINTS WELL INTO THE 70S ACROSS VALLEY LOCATIONS. HEAT INDEX
VALUES HAVE DROPPED BELOW THRESHOLDS AS WE HAVE EXPIRED THE HEAT
ADVISORY. NUMEROUS CONVECTIVE CELLS ARE NOW EXPANDING ACROSS MOST
OF EAST CENTRAL NEW YORK WITH NLDN REVEALING VERY IMPRESSIVE FLASH
DENSITY. PWATS ARE QUITE HIGH PER THE SPC HOURLY MESOSCALE WINDOW
AND THE THREAT FOR HEAVY RAINFALL REMAINS. INCREASED POPS AT THIS
TIME FOR MOST OF THE REGION AS SEVERE THUNDERSTORM WATCH REMAINS
IN EFFECT FOR MOST OF THE REGION.
AS OF 400 PM EDT...SEVERE THUNDERSTORM WATCH 521 CONTINUES UNTIL 10
PM FOR MUCH OF THE AREA EXCEPT FOR DUTCHESS/LITCHFIELD. ALSO A HEAT
ADVISORY REMAINS IN EFFECT UNTIL 6 PM FOR FOR THE HUDSON VALLEY FROM
GENERALLY GLENS FALLS SOUTHWARD TO POUGHKEEPSIE...AS WELL AS
LITCHFIELD CT.
A VERY SUMMER-LIKE DAY ACROSS THE AREA WITH A HOT AND HUMID AIR MASS
POSITIONED OVER THE REGION. TEMPERATURES STILL IN THE UPPER 80S TO
LOWER 90S...WITH OPPRESSIVE DEWPOINTS IN THE LOWER TO MID 70S. HEAT
INDEX VALUES ESPECIALLY IN THE HUDSON VALLEY...HAVE CONSISTENTLY
BEEN RUNNING IN THE 100-105 RANGE MUCH OF THE AFTERNOON. OPPRESSIVE
HEAT AND HUMIDITY OF THIS MAGNITUDE HAS NOT BEEN SEEN SINCE THE HEAT
WAVE BACK IN MID-JULY.
THE SUBSTANTIAL HEAT/HUMIDITY HAS RESULTED IN VERY HIGH LEVELS OF
INSTABILITY. THE SPECIAL 18Z SOUNDING FROM ALB INDICATED OVER 4000
J/KG OF SBCAPE! THE ENTIRE AREA IS EXTREMELY UNSTABLE...RANGING FROM
AROUND 3000 NORTH TO 5000 J/KG SOUTH FROM THE SPC RAP HOURLY
MESOSCALE ANALYSIS. THE BEST 0-6 KM SHEAR CONTINUES TO BE LOCATED
ACROSS NORTHERN PORTIONS OF THE AREA...GENERALLY IN THE 25-35 KT
RANGE...WITH WEAKER MAGNITUDE SOUTH. HOWEVER...DESPITE THE WEAKER
SHEAR FROM AROUND THE CAPITAL REGION SOUTHWARD...THE LARGE MAGNITUDE
OF CAPE WITH STEEP 850-500 MB LAPSE RATES OF OVER 7.0C/KM WILL STILL
RESULT IN A MULTICELL CONVECTIVE MODE WITH LARGE HAIL/DAMAGING WINDS
THE MAIN THREATS.
CONVECTION HAS BEEN INCREASING SUBSTANTIALLY IN COVERAGE ACROSS
SOUTH CENTRAL NY AND CENTRAL PA...AND IS EXPECTED TO SPREAD
NORTHEASTWARD INTO MUCH OF OUR AREA. STILL COME QUESTION AS TO THE
EVENTUAL COVERAGE...SO WILL MENTION SCATTERED COVERAGE FOR NOW. A
FEW CELLS HAVE ALREADY DEVELOPED ACROSS THE HIGHER TERRAIN OF THE
ADIRONDACKS/CATSKILLS. DEPENDING ON EVENTUAL CONVECTIVE
TRENDS...DUTCHESS/LITCHFIELD MAY NEED TO BE ADDED TO THE SEVERE
THUNDERSTORM WATCH LATER ON.
CONVECTION SHOULD START TO DECREASE IN INTENSITY AND EVENTUALLY
DIMINISH IN COVERAGE LATER THIS EVENING. WILL LOWER POPS TO MAINLY
SLIGHT CHANCE AFTER MIDNIGHT...WITH NO DISCERNIBLE FORCING
MECHANISMS AROUND. IT WILL BE ANOTHER WARM AND MUGGY NIGHT WITH LOWS
ONLY IN THE 65-70 RANGE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
THURSDAY LOOKS TO BE ANOTHER ACTIVE DAY ACROSS THE AREA...AS A COLD
FRONT AND UPPER LEVEL TROUGH APPROACH FROM THE GREAT LAKES. HIGH
LEVELS OF MOISTURE WILL REMAIN IN PLACE AHEAD OF THE
FRONT/TROUGH...WITH PWATS EXPECTED TO BE OVER 1.5 INCHES WHICH IS
BETWEEN 1 TO 2 STDEV ABOVE NORMAL FOR MID SEPTEMBER. LARGE SCALE
ASCENT WILL ALSO BE PRESENT...WITH SURFACE CONVERGENCE AHEAD OF AND
ALONG THE COLD FRONT AND UPPER LEVEL DYNAMICS ASSOCIATED WITH THE
TROUGH. SO THERE IS A HIGH PROBABILITY OF WIDESPREAD SHOWERS AND
THUNDERSTORMS...STARTING FROM MAINLY LATE MORNING ACROSS WESTERN
AREAS AND SHIFTING EASTWARD DURING THE AFTERNOON. WILL MENTION
LIKELY TO CATEGORICAL POPS FOR THE ENTIRE AREA.
WITH REGARDS TO THE POTENTIAL FOR SEVERE STORMS AGAIN...THERE IS
SOME QUESTION AS TO HOW MUCH INSTABILITY CAN BUILD AHEAD OF THE COLD
FRONT. THERE COULD BE QUITE A BIT OF CLOUD COVER TO START TO THE
DAY...BUT EXPECTED AT LEAST SOME BREAKS OF SUNSHINE...ESPECIALLY
FROM THE CAPITAL DISTRICT SOUTH AND EAST WHERE IT WILL TAKE LONGER
FOR THE FRONT TO APPROACH. FARTHER NORTH AND WEST OVER THE
ADIRONDACKS...THERE IS A SMALLER TIME WINDOW FOR BREAKS OF SUN AND
RESULTING INSTABILITY BUILDUP. SO EXPECTING THE MAIN THREAT AREA TO
BE FROM THE MOHAWK AND HUDSON VALLEYS SOUTH AND EAST. MAGNITUDE OF
CAPE IS NOT EXPECTED TO BE AS STRONG AS WEDNESDAY AND MID-LEVEL
LAPSE RATES ARE FORECAST TO BE WEAKER AND GENERALLY 6.0C/KM OR LESS.
THE DEEP LAYER SHEAR IS EXPECTED TO BE STRONGEST OVER THE NORTHERN
HALF OF THE AREA...AROUND 30-35 KT. SO THE MAIN THREATS ARE EXPECTED
TO BE DAMAGING WINDS FROM WET MICROBURSTS AND LOCALLY HEAVY
RAINFALL. ISOLATED FLASH FLOODING IS POSSIBLE...BUT SYNOPTIC SCALE
PARAMETERS DO NOT FAVOR A WIDESPREAD FLASH FLOOD EVENT.
MODEL GUIDANCE IN GENERAL AGREEMENT WITH SHOWING SHOWERS AND
T-STORMS LINGERING THROUGH MUCH OF THE EVENING...ESPECIALLY FROM THE
HUDSON VALLEY EASTWARD...AS IT WILL TAKE SOME TIME FOR THE COLD
FRONT TO CLEAR THE AREA. ANY SEVERE THREAT SHOULD DIMINISH AFTER
DARK WITH LOSS OF INSTABILITY. THE WIDESPREAD CONVECTION WILL TAPER
OFF TO SCATTERED SHOWERS OVERNIGHT.
FRIDAY LOOKS TO BE MUCH COOLER AND BREEZY BEHIND THE COLD FRONT.
TEMPERATURES WILL ACTUALLY BE BELOW NORMAL AFTER BEING WELL ABOVE
NORMAL FOR MUCH OF THE WEEK. THERE WILL LIKELY BE MORE CLOUDS THAN
SUNSHINE...WITH ISOLATED TO SCATTERED SHOWERS...AS THE UPPER TROUGH
AXIS MOVES OVERHEAD. THE BEST CHANCE FOR ANY MEASURABLE PRECIP WILL
BE OVER THE HIGHER TERRAIN. GRADUAL DRYING AND CLEARING EXPECTED
FRIDAY NIGHT AS THE UPPER TROUGH AXIS SHIFTS EAST OF THE AREA AND
HIGH PRESSURE BUILDS EASTWARD ACROSS THE GREAT LAKES. DRY AND COOL
WEATHER IN STORE FOR SATURDAY WITH HIGH PRESSURE BUILDING IN.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THIS WILL BE A RELATIVELY DRY PERIOD WITH THE ONLY FEATURE THAT MAY
BRING US A MAINLY SLIGHT CHANCE OF SHOWERS BEING A COLD FRONTAL
PASSAGE SUNDAY NIGHT. TEMPERATURES WILL BE SEASONABLY COOL
THROUGHOUT THE WEEK...WITH HIGHS RANGING FROM AROUND 60 DEGREES IN
THE HIGH PEAKS...TO AROUND 70 IN THE VALLEYS. BEHIND THE COLD
FRONT...HIGHS WILL RANGE FROM THE LOW AND MID 50S IN THE HIGHER
ELEVATIONS...TO THE MID AND UPPER 60S IN THE LOWER ELEVATIONS. BY
WEDNESDAY...READINGS WILL HAVE BOUNCED BACK TO HIGHS FROM AROUND 60
DEGREES IN THE HIGH PEAKS...TO AROUND 70 IN THE VALLEYS.
LOWS SATURDAY NIGHT WILL RANGE FROM THE LOWER AND MID 30S IN THE
HIGHER ELEVATIONS...TO MAINLY THE LOWER 40S DOWN THE HUDSON VALLEY
AND ACROSS THE SOUTHERN TIER. LOWS SUNDAY NIGHT WILL RANGE FROM THE
LOWER 40S TO LOWER 50S...BACKING OFF AGAIN MONDAY NIGHT TO LOWS
SIMILAR TO THOSE OF SATURDAY NIGHT. TUESDAY NIGHT LOWS WILL AVERAGE
SLIGHTLY MILDER. NORMAL HIGHS IN ALBANY FOR THIS PERIOD ARE IN THE
LOWER 70S...WITH THE NORMAL LOWS IN THE LOWER 50S.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
CLEAR SKIES ARE CURRENTLY IN PLACE ACROSS THE REGION WITH FEW-SCT
CU STARTING TO DEVELOP TO THE WEST OF THE TERMINALS OVER THE HIGH
TERRAIN OF THE ADIRONDACKS AND CATSKILLS. VFR CONDITIONS WILL BE
IN PLACE THROUGH THE REMAINDER OF THE EARLY TO MID AFTN HOURS.
BY THE LATE AFTN AND INTO THE EVENING...SCT THUNDERSTORMS DEVELOPING
OVER PA AND WESTERN/CENTRAL NY WILL SPREAD EASTWARD TOWARDS EASTERN
NY AND WESTERN NEW ENGLAND. WILL INCLUDE A VCSH AND A TEMPO FOR A
TSRA AT KGFL/KPSF/KALB. KPOU SHOULD BE FAR ENOUGH SOUTH TO AVOID THE
MAJORITY OF THE TSTORM ACTIVITY TODAY. FLYING CONDITIONS CAN BRIEFLY
DROP TO MVFR AND PERHAPS EVEN IFR WITHIN ANY TSTM AS IT PASSES OVER
THE REGION WITH GUSTY WESTERLY WINDS AS WELL.
SHRA/TSRA WILL DISSIPATE AND/OR MOVE AWAY FROM THE REGION BY THE
LATE EVENING. WITH THE HIGH LOW LEVEL MOISTURE IN PLACE...SOME
MIST/FOG WILL DEVELOP TONIGHT...ESP AT THOSE SITES THAT SEE RAINFALL
LATER THIS AFTN OR THIS EVENING. KGFL/KPSF WILL BE MOST SUSCEPTIBLE
TO DROPPING TO IFR VSBY DUE TO LOCAL TERRAIN EFFECTS...WITH AT LEAST
MVFR AT THE OTHER SITES AS WELL.
MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON THURSDAY MORNING INTO
AFTN AS A COLD FRONT APPROACHES. FOR NOW...WILL INCLUDE A VCSH AND
SHOW INCREASINGLY LOWER CIGS FOR THE MORNING HOURS.
OUTLOOK...
THURSDAY TO THURSDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY
SHRA...TSRA.
FRIDAY: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHRA.
FRIDAY NIGHT TO MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER ISSUES ARE EXPECTED AT THIS TIME. SCATTERED
THUNDERSTORMS WITH DOWNPOURS ARE EXPECTED INTO THIS EVENING BEFORE
WEAKENING. A STRONG COLD FRONT...ACCOMPANIED BY WIDESPREAD SHOWERS
AND THUNDERSTORMS WITH HEAVY RAIN...WILL MOVE ACROSS THE REGION
THURSDAY USHERING IN A MUCH COOLER AND LESS HUMID AUTUMN AIR MASS
FOR FRIDAY INTO THE WEEKEND.
&&
.HYDROLOGY...
SCATTERED SHOWERS AND THUNDERSTORMS WITH DOWNPOURS...ARE EXPECTED
ACROSS THE HSA DURING THE AFTERNOON AND EVENING HOURS TODAY
ASSOCIATED WITH A PRE FRONTAL TROUGH. MORE WIDESPREAD CONVECTION IS
EXPECTED ON THURSDAY WITH ADDITIONAL DOWNPOURS...ASSOCIATED WITH A
STRONG COLD FRONT DROPPING SOUTHEASTWARD THROUGH OUR REGION LATE
THURSDAY AND THURSDAY NIGHT. DRIER AND MUCH COOLER WEATHER IS
EXPECTED TO END THE WEEK.
WITHIN ANY SHOWERS OR THUNDERSTORMS...THERE WILL BE THE POTENTIAL
FOR MINOR FLOODING OF POOR DRAINAGE...URBAN...AND LOW LYING AREAS
DUE TO HEAVY RAIN FALLING IN A SHORT PERIOD OF TIME THIS AFTERNOON
INTO THIS EVENING. THERE IS EVEN A THREAT OF ISOLATED FLASH FLOODING
WHERE THUNDERSTORMS REPEATEDLY MOVE ACROSS THE SAME AREAS.
THUNDERSTORMS SHOULD DIMINISH LATER THIS EVENING INTO THE OVERNIGHT
HOURS.
THURSDAY INTO THURSDAY EVENING...WITH THE MORE WIDESPREAD SHOWERS
AND THUNDERSTORMS...SOME AREAS MAY RECEIVE AROUND 1 TO 2 INCHES OF
RAIN. AGAIN...MAINLY MINOR FLOODING OF POOR DRAINAGE...URBAN...AND
LOW LYING AREAS IS EXPECTED WITH ISOLATED FLASH FLOODING. WITHIN
BANK RISES WILL OCCUR ON SOME MAIN STEM RIVERS.
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...JPV
NEAR TERM...BGM/JPV
SHORT TERM...JPV
LONG TERM...ELH
AVIATION...FRUGIS
FIRE WEATHER...JPV
HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
424 PM EDT WED SEP 11 2013
.SYNOPSIS...
OUR REGION WILL REMAIN IN A WARM AND HUMID AIR MASS TONIGHT INTO
THURSDAY...AS A FRONTAL BOUNDARY REMAINS POSITIONED OVER THE UPPER
GREAT LAKES AND SOUTHEAST CANADA. AS THIS FRONT APPROACHES ON
THURSDAY...SHOWERS AND THUNDERSTORMS WILL BECOME MORE WIDESPREAD
ACROSS THE AREA. THE COLD FRONT WILL PASS THROUGH LATE THURSDAY INTO
THURSDAY NIGHT...AND WILL USHER IN A DRIER AND MUCH COOLER AIR MASS
FOR FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
AS OF 400 PM EDT...SEVERE THUNDERSTORM WATCH 521 CONTINUES UNTIL 10
PM FOR MUCH OF THE AREA EXCEPT FOR DUTCHESS/LITCHFIELD. ALSO A HEAT
ADVISORY REMAINS IN EFFECT UNTIL 6 PM FOR FOR THE HUDSON VALLEY FROM
GENERALLY GLENS FALLS SOUTHWARD TO POUGHKEEPSIE...AS WELL AS
LITCHFIELD CT.
A VERY SUMMER-LIKE DAY ACROSS THE AREA WITH A HOT AND HUMID AIR MASS
POSITIONED OVER THE REGION. TEMPERATURES STILL IN THE UPPER 80S TO
LOWER 90S...WITH OPPRESSIVE DEWPOINTS IN THE LOWER TO MID 70S. HEAT
INDEX VALUES ESPECIALLY IN THE HUDSON VALLEY...HAVE CONSISTENTLY
BEEN RUNNING IN THE 100-105 RANGE MUCH OF THE AFTERNOON. OPPRESSIVE
HEAT AND HUMIDITY OF THIS MAGNITUDE HAS NOT BEEN SEEN SINCE THE HEAT
WAVE BACK IN MID-JULY.
THE SUBSTANTIAL HEAT/HUMIDITY HAS RESULTED IN VERY HIGH LEVELS OF
INSTABILITY. THE SPECIAL 18Z SOUNDING FROM ALB INDICATED OVER 4000
J/KG OF SBCAPE! THE ENTIRE AREA IS EXTREMELY UNSTABLE...RANGING FROM
AROUND 3000 NORTH TO 5000 J/KG SOUTH FROM THE SPC RAP HOURLY
MESOSCALE ANALYSIS. THE BEST 0-6 KM SHEAR CONTINUES TO BE LOCATED
ACROSS NORTHERN PORTIONS OF THE AREA...GENERALLY IN THE 25-35 KT
RANGE...WITH WEAKER MAGNITUDE SOUTH. HOWEVER...DESPITE THE WEAKER
SHEAR FROM AROUND THE CAPITAL REGION SOUTHWARD...THE LARGE MAGNITUDE
OF CAPE WITH STEEP 850-500 MB LAPSE RATES OF OVER 7.0C/KM WILL STILL
RESULT IN A MULTICELL CONVECTIVE MODE WITH LARGE HAIL/DAMAGING WINDS
THE MAIN THREATS.
CONVECTION HAS BEEN INCREASING SUBSTANTIALLY IN COVERAGE ACROSS
SOUTH CENTRAL NY AND CENTRAL PA...AND IS EXPECTED TO SPREAD
NORTHEASTWARD INTO MUCH OF OUR AREA. STILL COME QUESTION AS TO THE
EVENTUAL COVERAGE...SO WILL MENTION SCATTERED COVERAGE FOR NOW. A
FEW CELLS HAVE ALREADY DEVELOPED ACROSS THE HIGHER TERRAIN OF THE
ADIRONDACKS/CATSKILLS. DEPENDING ON EVENTUAL CONVECTIVE
TRENDS...DUTCHESS/LITCHFIELD MAY NEED TO BE ADDED TO THE SEVERE
THUNDERSTORM WATCH LATER ON.
CONVECTION SHOULD START TO DECREASE IN INTENSITY AND EVENTUALLY
DIMINISH IN COVERAGE LATER THIS EVENING. WILL LOWER POPS TO MAINLY
SLIGHT CHANCE AFTER MIDNIGHT...WITH NO DISCERNIBLE FORCING
MECHANISMS AROUND. IT WILL BE ANOTHER WARM AND MUGGY NIGHT WITH LOWS
ONLY IN THE 65-70 RANGE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
THURSDAY LOOKS TO BE ANOTHER ACTIVE DAY ACROSS THE AREA...AS A COLD
FRONT AND UPPER LEVEL TROUGH APPROACH FROM THE GREAT LAKES. HIGH
LEVELS OF MOISTURE WILL REMAIN IN PLACE AHEAD OF THE
FRONT/TROUGH...WITH PWATS EXPECTED TO BE OVER 1.5 INCHES WHICH IS
BETWEEN 1 TO 2 STDEV ABOVE NORMAL FOR MID SEPTEMBER. LARGE SCALE
ASCENT WILL ALSO BE PRESENT...WITH SURFACE CONVERGENCE AHEAD OF AND
ALONG THE COLD FRONT AND UPPER LEVEL DYNAMICS ASSOCIATED WITH THE
TROUGH. SO THERE IS A HIGH PROBABILITY OF WIDESPREAD SHOWERS AND
THUNDERSTORMS...STARTING FROM MAINLY LATE MORNING ACROSS WESTERN
AREAS AND SHIFTING EASTWARD DURING THE AFTERNOON. WILL MENTION
LIKELY TO CATEGORICAL POPS FOR THE ENTIRE AREA.
WITH REGARDS TO THE POTENTIAL FOR SEVERE STORMS AGAIN...THERE IS
SOME QUESTION AS TO HOW MUCH INSTABILITY CAN BUILD AHEAD OF THE COLD
FRONT. THERE COULD BE QUITE A BIT OF CLOUD COVER TO START TO THE
DAY...BUT EXPECTED AT LEAST SOME BREAKS OF SUNSHINE...ESPECIALLY
FROM THE CAPITAL DISTRICT SOUTH AND EAST WHERE IT WILL TAKE LONGER
FOR THE FRONT TO APPROACH. FARTHER NORTH AND WEST OVER THE
ADIRONDACKS...THERE IS A SMALLER TIME WINDOW FOR BREAKS OF SUN AND
RESULTING INSTABILITY BUILDUP. SO EXPECTING THE MAIN THREAT AREA TO
BE FROM THE MOHAWK AND HUDSON VALLEYS SOUTH AND EAST. MAGNITUDE OF
CAPE IS NOT EXPECTED TO BE AS STRONG AS WEDNESDAY AND MID-LEVEL
LAPSE RATES ARE FORECAST TO BE WEAKER AND GENERALLY 6.0C/KM OR LESS.
THE DEEP LAYER SHEAR IS EXPECTED TO BE STRONGEST OVER THE NORTHERN
HALF OF THE AREA...AROUND 30-35 KT. SO THE MAIN THREATS ARE EXPECTED
TO BE DAMAGING WINDS FROM WET MICROBURSTS AND LOCALLY HEAVY
RAINFALL. ISOLATED FLASH FLOODING IS POSSIBLE...BUT SYNOPTIC SCALE
PARAMETERS DO NOT FAVOR A WIDESPREAD FLASH FLOOD EVENT.
MODEL GUIDANCE IN GENERAL AGREEMENT WITH SHOWING SHOWERS AND
T-STORMS LINGERING THROUGH MUCH OF THE EVENING...ESPECIALLY FROM THE
HUDSON VALLEY EASTWARD...AS IT WILL TAKE SOME TIME FOR THE COLD
FRONT TO CLEAR THE AREA. ANY SEVERE THREAT SHOULD DIMINISH AFTER
DARK WITH LOSS OF INSTABILITY. THE WIDESPREAD CONVECTION WILL TAPER
OFF TO SCATTERED SHOWERS OVERNIGHT.
FRIDAY LOOKS TO BE MUCH COOLER AND BREEZY BEHIND THE COLD FRONT.
TEMPERATURES WILL ACTUALLY BE BELOW NORMAL AFTER BEING WELL ABOVE
NORMAL FOR MUCH OF THE WEEK. THERE WILL LIKELY BE MORE CLOUDS THAN
SUNSHINE...WITH ISOLATED TO SCATTERED SHOWERS...AS THE UPPER TROUGH
AXIS MOVES OVERHEAD. THE BEST CHANCE FOR ANY MEASURABLE PRECIP WILL
BE OVER THE HIGHER TERRAIN. GRADUAL DRYING AND CLEARING EXPECTED
FRIDAY NIGHT AS THE UPPER TROUGH AXIS SHIFTS EAST OF THE AREA AND
HIGH PRESSURE BUILDS EASTWARD ACROSS THE GREAT LAKES. DRY AND COOL
WEATHER IN STORE FOR SATURDAY WITH HIGH PRESSURE BUILDING IN.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THIS WILL BE A RELATIVELY DRY PERIOD WITH THE ONLY FEATURE THAT MAY
BRING US A MAINLY SLIGHT CHANCE OF SHOWERS BEING A COLD FRONTAL
PASSAGE SUNDAY NIGHT. TEMPERATURES WILL BE SEASONABLY COOL
THROUGHOUT THE WEEK...WITH HIGHS RANGING FROM AROUND 60 DEGREES IN
THE HIGH PEAKS...TO AROUND 70 IN THE VALLEYS. BEHIND THE COLD
FRONT...HIGHS WILL RANGE FROM THE LOW AND MID 50S IN THE HIGHER
ELEVATIONS...TO THE MID AND UPPER 60S IN THE LOWER ELEVATIONS. BY
WEDNESDAY...READINGS WILL HAVE BOUNCED BACK TO HIGHS FROM AROUND 60
DEGREES IN THE HIGH PEAKS...TO AROUND 70 IN THE VALLEYS.
LOWS SATURDAY NIGHT WILL RANGE FROM THE LOWER AND MID 30S IN THE
HIGHER ELEVATIONS...TO MAINLY THE LOWER 40S DOWN THE HUDSON VALLEY
AND ACROSS THE SOUTHERN TIER. LOWS SUNDAY NIGHT WILL RANGE FROM THE
LOWER 40S TO LOWER 50S...BACKING OFF AGAIN MONDAY NIGHT TO LOWS
SIMILAR TO THOSE OF SATURDAY NIGHT. TUESDAY NIGHT LOWS WILL AVERAGE
SLIGHTLY MILDER. NORMAL HIGHS IN ALBANY FOR THIS PERIOD ARE IN THE
LOWER 70S...WITH THE NORMAL LOWS IN THE LOWER 50S.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
CLEAR SKIES ARE CURRENTLY IN PLACE ACROSS THE REGION WITH FEW-SCT
CU STARTING TO DEVELOP TO THE WEST OF THE TERMINALS OVER THE HIGH
TERRAIN OF THE ADIRONDACKS AND CATSKILLS. VFR CONDITIONS WILL BE
IN PLACE THROUGH THE REMAINDER OF THE EARLY TO MID AFTN HOURS.
BY THE LATE AFTN AND INTO THE EVENING...SCT THUNDERSTORMS DEVELOPING
OVER PA AND WESTERN/CENTRAL NY WILL SPREAD EASTWARD TOWARDS EASTERN
NY AND WESTERN NEW ENGLAND. WILL INCLUDE A VCSH AND A TEMPO FOR A
TSRA AT KGFL/KPSF/KALB. KPOU SHOULD BE FAR ENOUGH SOUTH TO AVOID THE
MAJORITY OF THE TSTORM ACTIVITY TODAY. FLYING CONDITIONS CAN BRIEFLY
DROP TO MVFR AND PERHAPS EVEN IFR WITHIN ANY TSTM AS IT PASSES OVER
THE REGION WITH GUSTY WESTERLY WINDS AS WELL.
SHRA/TSRA WILL DISSIPATE AND/OR MOVE AWAY FROM THE REGION BY THE
LATE EVENING. WITH THE HIGH LOW LEVEL MOISTURE IN PLACE...SOME
MIST/FOG WILL DEVELOP TONIGHT...ESP AT THOSE SITES THAT SEE RAINFALL
LATER THIS AFTN OR THIS EVENING. KGFL/KPSF WILL BE MOST SUSCEPTIBLE
TO DROPPING TO IFR VSBY DUE TO LOCAL TERRAIN EFFECTS...WITH AT LEAST
MVFR AT THE OTHER SITES AS WELL.
MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON THURSDAY MORNING INTO
AFTN AS A COLD FRONT APPROACHES. FOR NOW...WILL INCLUDE A VCSH AND
SHOW INCREASINGLY LOWER CIGS FOR THE MORNING HOURS.
OUTLOOK...
THURSDAY TO THURSDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY
SHRA...TSRA.
FRIDAY: LOW OPERATIONAL IMPACT. BREEZY. SLIGHT CHANCE OF SHRA.
FRIDAY NIGHT TO MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER ISSUES ARE EXPECTED AT THIS TIME. SCATTERED
THUNDERSTORMS WITH DOWNPOURS ARE EXPECTED INTO THIS EVENING BEFORE
WEAKENING. A STRONG COLD FRONT...ACCOMPANIED BY WIDESPREAD SHOWERS
AND THUNDERSTORMS WITH HEAVY RAIN...WILL MOVE ACROSS THE REGION
THURSDAY USHERING IN A MUCH COOLER AND LESS HUMID AUTUMN AIR MASS
FOR FRIDAY INTO THE WEEKEND.
&&
.HYDROLOGY...
SCATTERED SHOWERS AND THUNDERSTORMS WITH DOWNPOURS...ARE EXPECTED
ACROSS THE HSA DURING THE AFTERNOON AND EVENING HOURS TODAY
ASSOCIATED WITH A PRE FRONTAL TROUGH. MORE WIDESPREAD CONVECTION IS
EXPECTED ON THURSDAY WITH ADDITIONAL DOWNPOURS...ASSOCIATED WITH A
STRONG COLD FRONT DROPPING SOUTHEASTWARD THROUGH OUR REGION LATE
THURSDAY AND THURSDAY NIGHT. DRIER AND MUCH COOLER WEATHER IS
EXPECTED TO END THE WEEK.
WITHIN ANY SHOWERS OR THUNDERSTORMS...THERE WILL BE THE POTENTIAL
FOR MINOR FLOODING OF POOR DRAINAGE...URBAN...AND LOW LYING AREAS
DUE TO HEAVY RAIN FALLING IN A SHORT PERIOD OF TIME THIS AFTERNOON
INTO THIS EVENING. THERE IS EVEN A THREAT OF ISOLATED FLASH FLOODING
WHERE THUNDERSTORMS REPEATEDLY MOVE ACROSS THE SAME AREAS.
THUNDERSTORMS SHOULD DIMINISH LATER THIS EVENING INTO THE OVERNIGHT
HOURS.
THURSDAY INTO THURSDAY EVENING...WITH THE MORE WIDESPREAD SHOWERS
AND THUNDERSTORMS...SOME AREAS MAY RECEIVE AROUND 1 TO 2 INCHES OF
RAIN. AGAIN...MAINLY MINOR FLOODING OF POOR DRAINAGE...URBAN...AND
LOW LYING AREAS IS EXPECTED WITH ISOLATED FLASH FLOODING. WITHIN
BANK RISES WILL OCCUR ON SOME MAIN STEM RIVERS.
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...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR CTZ001-013.
NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ041-049-050-
052-053-059-060-064-065-083-084.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...JPV
NEAR TERM...JPV
SHORT TERM...JPV
LONG TERM...ELH
AVIATION...FRUGIS
FIRE WEATHER...JPV
HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
118 PM EDT WED SEP 11 2013
.SYNOPSIS...
HAZY...HOT AND HUMID CONDITIONS ARE IN STORE FOR OUR
REGION THIS AFTERNOON WITH A CHANCE FOR A SHOWER OR
THUNDERSTORM...SOME OF WHICH MAY LOCALLY BE SEVERE. A STRONG COLD
FRONT...ACCOMPANIED BY WIDESPREAD SHOWERS AND THUNDERSTORMS WITH
HEAVY RAIN...WILL MOVE ACROSS THE REGION THURSDAY USHERING IN A MUCH
COOLER AND LESS HUMID AUTUMN AIR MASS FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 115 PM EDT...MULTIPLE HAZARDS TO DEAL WITH TODAY. HAD TO
ISSUE A SHORT-FUSE HEAT ADVISORY FOR THE HUDSON VALLEY FROM
GENERALLY GLENS FALLS SOUTHWARD TO POUGHKEEPSIE...AS WELL AS
LITCHFIELD CT. TEMPERATURES HAVE ALREADY WARMED TO THE UPPER 80S
TO LOWER 90S WITH SURFACE DEWPOINTS RUNNING HIGHER THAN EXPECTED
IN THE LOWER TO EVEN MID 70S! HEAT INDICES WILL BE IN THE LOWER
100S IN THE ADVISORY AREA.
WITH REGARDS TO CONVECTIVE POTENTIAL...STILL MAINLY CLEAR/HAZY
SKIES ACROSS MUCH OF THE AREA...ALTHOUGH CU STARTING TO POP UP
OVER THE HIGHER TERRAIN OF THE CATSKILLS/ADIRONDACKS. MORE
WIDESPREAD/AGITATED CU FARTHER SOUTH AND WEST OVER PA AND SW NY
STATE. THIS IS WHERE CONVECTION IS STARTING TO INITIATE AND IS
WHERE THE MESOSCALE MODELS ARE DEPICTING INITIATION. SCATTERED
T-STORMS ARE EXPECTED TO PROGRESS NORTHEASTWARD INTO OUR AREA
MAINLY DURING THE LATE AFTERNOON INTO THE EARLY EVENING HOURS.
EXTREME INSTABILITY IS EXPECTED...AS SEEN IN THE 12Z KALY
SOUNDING AND SPC RAP MESOSCALE ANALYSIS SHOWING AROUND 3000-5000
J/KG OF SBCAPE ACROSS OUR AREA AT THIS HOUR! IN ADDITION...MID
LEVEL LAPSE RATES IN THE 700HPA TO 500HPA LAYER ARE VERY
IMPRESSIVE WITH READINGS AROUND 7.5 C/KM...AS A PIECE OF THE
ELEVATED MIXED LAYER /EML/ THAT PASSED OVER THE AREA YESTERDAY
REMAINS. SBCAPE VALUES WILL EASILY EXCEED 3000-4000 J/KG BY THIS
AFTN AS SURFACE TEMPS WARM INTO THE LOW 90S...WITH DEWPOINTS IN
THE LOW TO MID 70S. 0-6 KM BULK SHEAR IS MAXIMIZED FURTHER NORTH
ACROSS FAR NORTHERN NY AND THE ST. LAWRENCE VALLEY CLOSER TO A SFC
FRONTAL BOUNDARY...WITH 30-40 KTS FOR THE CENTRAL/NORTHERN HALF OF
OUR AREA.
SYNOPTICALLY...THE MAIN SFC FRONTAL BOUNDARY REMAINS WELL NORTH
AND WEST ACROSS SOUTHERN CANADA...THUS THE CONVECTIVE DEVELOPMENT
WOULD LIKELY BE DUE TO TERRAIN FORCING AND PERHAPS A PRE-FRONTAL
TROUGH. WILL CONTINUE MENTION POTENTIAL FOR SEVERE STORMS IN OUR
HWO PRODUCT. DAMAGING WINDS LOOKS TO BE THE PRIMARY THREAT WITH
ANY STORM...BUT CONSIDERING THAT UPDRAFT STRENGTH COULD BE
MAXIMIZED WITH THE STEEP LAPSE RATES AND ROBUST CAPE IN
PLACE...LARGE HAIL IS POSSIBLE AS WELL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
TONIGHT...EXPECT SHOWERS AND THUNDERSTORMS TO BECOME MORE
NUMEROUS OVERNIGHT ESPECIALLY ACROSS NORTHWEST PORTION OF FA AS
COLD FRONT STARTS TO DROP SOUTHEAST TOWARDS SAINT LAWRENCE VALLEY
LATE AT NIGHT. LOWS ARE EXPECTED TO BE IN THE MID 60S TO AROUND 70.
THURSDAY AND THURSDAY NIGHT...LOOKS LIKE THE POTENTIAL FOR VERY
HEAVY RAIN AS SEVERAL WAVES OF LOW PRESSURE TRACK NORTHEAST ALONG
THE COLD FRONT AS IT SLIDES SLOWLY SOUTHEAST THROUGH FA. PWATS MAY
BRIEFLY EXCEED 2 INCHES AND WITH TREMENDOUS THETA-E RIDGE H10-H8
SLICING RIGHT THROUGH CENTER PORTION OF FA THURSDAY AFT BELIEVE
POTENTIAL EXISTS FOR UP TO SEVERAL INCHES OF RAIN. SPC STILL HAS
MUCH OF FA OUTLOOKED SLIGHT RISK AND THIS WILL DEPEND GREATLY ON
HOW MUCH SURFACE HEATING TAKES PLACE. POSSIBILITY EXISTS THAT ONE
OR MORE LINE SEGMENTS MAY DEVELOP WITH CAPES 1500-2500 J/KG AND
BULK SHEAR INCREASING TO 30 TO 40 KTS. EXPECT HIGHS ON THURSDAY
TO RANGE FROM THE MID 70S NORTHWEST TO MID 80S SOUTHEAST WITH LOWS
THURSDAY NIGHT RANGING FROM THE UPPER 40S NORTHWEST TO UPPER 50S
TO AROUND 60 SOUTHEAST.
FRIDAY AND FRIDAY NIGHT...STILL CANNOT RULE OUT A FEW SHOWERS ON
FRIDAY AS UPPER TROUGH AXIS AND ASSOCIATED VORT MAX SWING ACRS FA.
ON FRIDAY NIGHT ANY LINGERING SCATTERED SHOWERS SHOULD BE
CONFINED TO EXTREME NORTHEAST PORTION OF FA AS UPPER TROUGH AXIS
GRADUALLY SLIDES EAST OF FA. EXPECT MUCH COOLER CONDITIONS WITH
HIGHS ON FRIDAY ONLY RANGING FROM THE MID 50S NORTHWEST TO UPPER
60S TO AROUND 70 SOUTHEAST. LOWS FRIDAY NIGHT ARE EXPECTED TO
RANGE FROM THE UPPER 30S NORTHWEST TO MID 40S SOUTHEAST.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AN UPPER LEVEL TROUGH WILL BE LIFTING NORTH OF NY AND NEW ENGLAND TO
OPEN THE WEEKEND. SFC HIGH PRESSURE WILL BE RIDGING IN FROM THE
LOWER GREAT LAKES AND OHIO. NW FLOW WILL DOMINATE ALOFT. COOL AND
BREEZY CONDITIONS ARE EXPECTED ON SATURDAY...AS H850 TEMPS WILL BE
ONLY +3C TO +5C OVER THE FCST AREA BY MID PM. MAX TEMPS WILL RUN
ABOUT 10 DEGREES BELOW NORMAL WITH HIGHS 60-65F IN THE VALLEYS...AND
GENERALLY MID TO U50S OVER THE HILLS AND MTNS.
SATURDAY NIGHT INTO SUNDAY...THE SFC HIGH MOVES OVER NY AND PA...AND
THEN SLIDES SOUTH AND EAST OFF THE NJ COAST. LOW AND MID LEVEL WARM
ADVECTION WILL OCCUR OVER THE REGION. AFTER A COOL START SUNDAY
MORNING WITH MIN TEMPS RUNNING FROM THE MID AND U30S OVER THE
SRN DACKS TO LOWER TO MID 40S OVER THE HUDSON RIVER VALLEY AND NW
CT...A NICE SUNDAY IS EXPECTED. PARTLY TO MOSTLY SUNNY CONDITIONS
WILL PREVAIL WITH TEMPS MAINLY IN THE 60S TO A FEW L70S OVER THE MID
HUDSON VALLEY. ANOTHER LONG-WAVE UPPER LEVEL TROUGH WILL BE MOVING
EASTWARD ACROSS HUDSON BAY. THIS UPPER TROUGH WILL ALLOW A COLD
FRONT TO APPROACH FROM THE GREAT LAKES REGION AND ST LAWRENCE RIVER
VALLEY FOR THE OPENING OF THE WORK AND SCHOOL WEEK.
SUNDAY NIGHT INTO MONDAY...THE MEDIUM RANGE GUIDANCE VARIES SLIGHTLY
ON THE TIMING AND PASSAGE OF THE COLD FRONT. THE WPC GUIDANCE WAS A
GOOD COMPROMISE WITH THE BOUNDARY MOVING THROUGH IN THE LATE MORNING
AND EARLY PM. SOME LAKE MOISTURE MAY BE UTILIZED...BUT THE OVERALL
LOW-LEVEL CONVERGENCE WITH A PRE-FRONTAL SFC TROUGH...AND THE ACTUAL
COLD FRONT LOOKS PRETTY MEAGER. SLIGHT TO LOW CHC POPS WERE USED
SUNDAY NIGHT UNTIL LUNCH-TIME ON MONDAY FROM THE I-90 CORRIDOR
NORTHWARD FOR SHOWERS. LOWS MONDAY MORNING ARE EXPECTED IN THE 40S
TO L50S...WITH HIGHS SIMILAR TO SUNDAY...BUT A SHADE COOLER OVER THE
SRN GREENS AND SRN DACKS.
MONDAY NIGHT INTO TUESDAY...ANOTHER BROAD CANADIAN SFC ANTICYCLONE
WILL BUILD IN ACROSS THE NORTHEAST FROM SE ONTARIO AND THE UPPER
GREAT LAKES REGION. THE SUBSIDENCE FROM THE HIGH WILL YIELD CLEAR
AND COOL CONDITIONS WITH TEMPS STILL RUNNING BELOW NORMAL FOR MID
SEPT.
OVERALL...PCPN AND TEMPS LOOK BELOW NORMAL IN THE LONG TERM.
&&
.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
CLEAR SKIES ARE CURRENTLY IN PLACE ACROSS THE REGION WITH FEW-SCT
CU STARTING TO DEVELOP TO THE WEST OF THE TERMINALS OVER THE HIGH
TERRAIN OF THE ADIRONDACKS AND CATSKILLS. VFR CONDITIONS WILL BE
IN PLACE THROUGH THE REMAINDER OF THE EARLY TO MID AFTN HOURS.
BY THE LATE AFTN AND INTO THE EVENING...SCT THUNDERSTORMS DEVELOPING
OVER PA AND WESTERN/CENTRAL NY WILL SPREAD EASTWARD TOWARDS EASTERN
NY AND WESTERN NEW ENGLAND. WILL INCLUDE A VCSH AND A TEMPO FOR A
TSRA AT KGFL/KPSF/KALB. KPOU SHOULD BE FAR ENOUGH SOUTH TO AVOID THE
MAJORITY OF THE TSTORM ACTIVITY TODAY. FLYING CONDITIONS CAN BRIEFLY
DROP TO MVFR AND PERHAPS EVEN IFR WITHIN ANY TSTM AS IT PASSES OVER
THE REGION WITH GUSTY WESTERLY WINDS AS WELL.
SHRA/TSRA WILL DISSIPATE AND/OR MOVE AWAY FROM THE REGION BY THE
LATE EVENING. WITH THE HIGH LOW LEVEL MOISTURE IN PLACE...SOME
MIST/FOG WILL DEVELOP TONIGHT...ESP AT THOSE SITES THAT SEE RAINFALL
LATER THIS AFTN OR THIS EVENING. KGFL/KPSF WILL BE MOST SUSCEPTIBLE
TO DROPPING TO IFR VSBY DUE TO LOCAL TERRAIN EFFECTS...WITH AT LEAST
MVFR AT THE OTHER SITES AS WELL.
MORE SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON THURSDAY MORNING INTO
AFTN AS A COLD FRONT APPROACHES. FOR NOW...WILL INCLUDE A VCSH AND
SHOW INCREASINGLY LOWER CIGS FOR THE MORNING HOURS.
OUTLOOK...
THURSDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY TO SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED ISSUES ARE ANTICIPATED OVER THE NEXT
SEVERAL DAYS.
HAZY...HOT AND HUMID CONDITIONS ARE IN STORE FOR OUR REGION TODAY
WITH A CHANCE FOR A SHOWER OR THUNDERSTORM. A STRONG COLD
FRONT...ACCOMPANIED BY WIDESPREAD SHOWERS AND THUNDERSTORMS WITH
HEAVY RAIN...WILL MOVE ACROSS THE REGION THURSDAY USHERING IN A
MUCH COOLER AND LESS HUMID AUTUMN AIR MASS FOR THE REMAINDER OF
THE WEEK.
&&
.HYDROLOGY...
WIDELY SCATTERED TO SCATTERED SHOWERS AND THUNDERSTORMS...SOME
WITH VERY HEAVY DOWNPOURS...ARE EXPECTED ACROSS THE HSA DURING THE
AFTERNOON AND EVENING HOURS TODAY LIKELY ASSOCIATED WITH A PRE
FRONTAL TROUGH. MORE WIDESPREAD CONVECTION IS EXPECTED LATE
TONIGHT INTO THURSDAY EVENING WITH HEAVY RAINFALL AS ONE OR MORE
WAVES OF LOW PRESSURE ARE EXPECTED TO TRACK NORTHEAST ALONG A
STRONG COLD FRONT WHICH WILL BE DROPPING SOUTHEAST THROUGH OUR
REGION LATE THURSDAY AND THURSDAY NIGHT. DRIER AND COOLER WEATHER
IS EXPECTED TO END THE WEEK
WITHIN ANY SHOWER OR THUNDERSTORM...THERE WILL BE THE POTENTIAL FOR
MINOR FLOODING OF POOR DRAINAGE...URBAN...AND LOW LYING AREAS DUE TO
VERY HEAVY RAINFALL IN A SHORT PERIOD OF TIME TODAY THROUGH
THIS EVENING. LATE TONIGHT THROUGH THURSDAY EVENING EXPECT A MORE
WIDESPREAD HEAVY RAIN EVENT WITH SIGNIFICANT RISES OCCURRING ON
SOME MAIN STEM RIVERS WITH UP TO SEVERAL INCHES OF RAIN POSSIBLE.
IN ADDITION FLOODING OF SMALL STREAMS AND CREEKS MAY ALSO OCCUR.
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...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR CTZ001-013.
NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ041-049-050-
052-053-059-060-064-065-083-084.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS/JPV
SHORT TERM...11
LONG TERM...WASULA
AVIATION...FRUGIS
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS ALBANY NY
115 PM EDT WED SEP 11 2013
.SYNOPSIS...
HAZY...HOT AND HUMID CONDITIONS ARE IN STORE FOR OUR
REGION THIS AFTERNOON WITH A CHANCE FOR A SHOWER OR
THUNDERSTORM...SOME OF WHICH MAY LOCALLY BE SEVERE. A STRONG COLD
FRONT...ACCOMPANIED BY WIDESPREAD SHOWERS AND THUNDERSTORMS WITH
HEAVY RAIN...WILL MOVE ACROSS THE REGION THURSDAY USHERING IN A MUCH
COOLER AND LESS HUMID AUTUMN AIR MASS FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 115 PM EDT...MULTIPLE HAZARDS TO DEAL WITH TODAY. HAD TO
ISSUE A SHORT-FUSE HEAT ADVISORY FOR THE HUDSON VALLEY FROM
GENERALLY GLENS FALLS SOUTHWARD TO POUGHKEEPSIE...AS WELL AS
LITCHFIELD CT. TEMPERATURES HAVE ALREADY WARMED TO THE UPPER 80S
TO LOWER 90S WITH SURFACE DEWPOINTS RUNNING HIGHER THAN EXPECTED
IN THE LOWER TO EVEN MID 70S! HEAT INDICES WILL BE IN THE LOWER
100S IN THE ADVISORY AREA.
WITH REGARDS TO CONVECTIVE POTENTIAL...STILL MAINLY CLEAR/HAZY
SKIES ACROSS MUCH OF THE AREA...ALTHOUGH CU STARTING TO POP UP
OVER THE HIGHER TERRAIN OF THE CATSKILLS/ADIRONDACKS. MORE
WIDESPREAD/AGITATED CU FARTHER SOUTH AND WEST OVER PA AND SW NY
STATE. THIS IS WHERE CONVECTION IS STARTING TO INITIATE AND IS
WHERE THE MESOSCALE MODELS ARE DEPICTING INITIATION. SCATTERED
T-STORMS ARE EXPECTED TO PROGRESS NORTHEASTWARD INTO OUR AREA
MAINLY DURING THE LATE AFTERNOON INTO THE EARLY EVENING HOURS.
EXTREME INSTABILITY IS EXPECTED...AS SEEN IN THE 12Z KALY
SOUNDING AND SPC RAP MESOSCALE ANALYSIS SHOWING AROUND 3000-5000
J/KG OF SBCAPE ACROSS OUR AREA AT THIS HOUR! IN ADDITION...MID
LEVEL LAPSE RATES IN THE 700HPA TO 500HPA LAYER ARE VERY
IMPRESSIVE WITH READINGS AROUND 7.5 C/KM...AS A PIECE OF THE
ELEVATED MIXED LAYER /EML/ THAT PASSED OVER THE AREA YESTERDAY
REMAINS. SBCAPE VALUES WILL EASILY EXCEED 3000-4000 J/KG BY THIS
AFTN AS SURFACE TEMPS WARM INTO THE LOW 90S...WITH DEWPOINTS IN
THE LOW TO MID 70S. 0-6 KM BULK SHEAR IS MAXIMIZED FURTHER NORTH
ACROSS FAR NORTHERN NY AND THE ST. LAWRENCE VALLEY CLOSER TO A SFC
FRONTAL BOUNDARY...WITH 30-40 KTS FOR THE CENTRAL/NORTHERN HALF OF
OUR AREA.
SYNOPTICALLY...THE MAIN SFC FRONTAL BOUNDARY REMAINS WELL NORTH
AND WEST ACROSS SOUTHERN CANADA...THUS THE CONVECTIVE DEVELOPMENT
WOULD LIKELY BE DUE TO TERRAIN FORCING AND PERHAPS A PRE-FRONTAL
TROUGH. WILL CONTINUE MENTION POTENTIAL FOR SEVERE STORMS IN OUR
HWO PRODUCT. DAMAGING WINDS LOOKS TO BE THE PRIMARY THREAT WITH
ANY STORM...BUT CONSIDERING THAT UPDRAFT STRENGTH COULD BE
MAXIMIZED WITH THE STEEP LAPSE RATES AND ROBUST CAPE IN
PLACE...LARGE HAIL IS POSSIBLE AS WELL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
TONIGHT...EXPECT SHOWERS AND THUNDERSTORMS TO BECOME MORE
NUMEROUS OVERNIGHT ESPECIALLY ACROSS NORTHWEST PORTION OF FA AS
COLD FRONT STARTS TO DROP SOUTHEAST TOWARDS SAINT LAWRENCE VALLEY
LATE AT NIGHT. LOWS ARE EXPECTED TO BE IN THE MID 60S TO AROUND 70.
THURSDAY AND THURSDAY NIGHT...LOOKS LIKE THE POTENTIAL FOR VERY
HEAVY RAIN AS SEVERAL WAVES OF LOW PRESSURE TRACK NORTHEAST ALONG
THE COLD FRONT AS IT SLIDES SLOWLY SOUTHEAST THROUGH FA. PWATS MAY
BRIEFLY EXCEED 2 INCHES AND WITH TREMENDOUS THETA-E RIDGE H10-H8
SLICING RIGHT THROUGH CENTER PORTION OF FA THURSDAY AFT BELIEVE
POTENTIAL EXISTS FOR UP TO SEVERAL INCHES OF RAIN. SPC STILL HAS
MUCH OF FA OUTLOOKED SLIGHT RISK AND THIS WILL DEPEND GREATLY ON
HOW MUCH SURFACE HEATING TAKES PLACE. POSSIBILITY EXISTS THAT ONE
OR MORE LINE SEGMENTS MAY DEVELOP WITH CAPES 1500-2500 J/KG AND
BULK SHEAR INCREASING TO 30 TO 40 KTS. EXPECT HIGHS ON THURSDAY
TO RANGE FROM THE MID 70S NORTHWEST TO MID 80S SOUTHEAST WITH LOWS
THURSDAY NIGHT RANGING FROM THE UPPER 40S NORTHWEST TO UPPER 50S
TO AROUND 60 SOUTHEAST.
FRIDAY AND FRIDAY NIGHT...STILL CANNOT RULE OUT A FEW SHOWERS ON
FRIDAY AS UPPER TROUGH AXIS AND ASSOCIATED VORT MAX SWING ACRS FA.
ON FRIDAY NIGHT ANY LINGERING SCATTERED SHOWERS SHOULD BE
CONFINED TO EXTREME NORTHEAST PORTION OF FA AS UPPER TROUGH AXIS
GRADUALLY SLIDES EAST OF FA. EXPECT MUCH COOLER CONDITIONS WITH
HIGHS ON FRIDAY ONLY RANGING FROM THE MID 50S NORTHWEST TO UPPER
60S TO AROUND 70 SOUTHEAST. LOWS FRIDAY NIGHT ARE EXPECTED TO
RANGE FROM THE UPPER 30S NORTHWEST TO MID 40S SOUTHEAST.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AN UPPER LEVEL TROUGH WILL BE LIFTING NORTH OF NY AND NEW ENGLAND TO
OPEN THE WEEKEND. SFC HIGH PRESSURE WILL BE RIDGING IN FROM THE
LOWER GREAT LAKES AND OHIO. NW FLOW WILL DOMINATE ALOFT. COOL AND
BREEZY CONDITIONS ARE EXPECTED ON SATURDAY...AS H850 TEMPS WILL BE
ONLY +3C TO +5C OVER THE FCST AREA BY MID PM. MAX TEMPS WILL RUN
ABOUT 10 DEGREES BELOW NORMAL WITH HIGHS 60-65F IN THE VALLEYS...AND
GENERALLY MID TO U50S OVER THE HILLS AND MTNS.
SATURDAY NIGHT INTO SUNDAY...THE SFC HIGH MOVES OVER NY AND PA...AND
THEN SLIDES SOUTH AND EAST OFF THE NJ COAST. LOW AND MID LEVEL WARM
ADVECTION WILL OCCUR OVER THE REGION. AFTER A COOL START SUNDAY
MORNING WITH MIN TEMPS RUNNING FROM THE MID AND U30S OVER THE
SRN DACKS TO LOWER TO MID 40S OVER THE HUDSON RIVER VALLEY AND NW
CT...A NICE SUNDAY IS EXPECTED. PARTLY TO MOSTLY SUNNY CONDITIONS
WILL PREVAIL WITH TEMPS MAINLY IN THE 60S TO A FEW L70S OVER THE MID
HUDSON VALLEY. ANOTHER LONG-WAVE UPPER LEVEL TROUGH WILL BE MOVING
EASTWARD ACROSS HUDSON BAY. THIS UPPER TROUGH WILL ALLOW A COLD
FRONT TO APPROACH FROM THE GREAT LAKES REGION AND ST LAWRENCE RIVER
VALLEY FOR THE OPENING OF THE WORK AND SCHOOL WEEK.
SUNDAY NIGHT INTO MONDAY...THE MEDIUM RANGE GUIDANCE VARIES SLIGHTLY
ON THE TIMING AND PASSAGE OF THE COLD FRONT. THE WPC GUIDANCE WAS A
GOOD COMPROMISE WITH THE BOUNDARY MOVING THROUGH IN THE LATE MORNING
AND EARLY PM. SOME LAKE MOISTURE MAY BE UTILIZED...BUT THE OVERALL
LOW-LEVEL CONVERGENCE WITH A PRE-FRONTAL SFC TROUGH...AND THE ACTUAL
COLD FRONT LOOKS PRETTY MEAGER. SLIGHT TO LOW CHC POPS WERE USED
SUNDAY NIGHT UNTIL LUNCH-TIME ON MONDAY FROM THE I-90 CORRIDOR
NORTHWARD FOR SHOWERS. LOWS MONDAY MORNING ARE EXPECTED IN THE 40S
TO L50S...WITH HIGHS SIMILAR TO SUNDAY...BUT A SHADE COOLER OVER THE
SRN GREENS AND SRN DACKS.
MONDAY NIGHT INTO TUESDAY...ANOTHER BROAD CANADIAN SFC ANTICYCLONE
WILL BUILD IN ACROSS THE NORTHEAST FROM SE ONTARIO AND THE UPPER
GREAT LAKES REGION. THE SUBSIDENCE FROM THE HIGH WILL YIELD CLEAR
AND COOL CONDITIONS WITH TEMPS STILL RUNNING BELOW NORMAL FOR MID
SEPT.
OVERALL...PCPN AND TEMPS LOOK BELOW NORMAL IN THE LONG TERM.
&&
.AVIATION /17Z WEDNESDAY THROUGH SUNDAY/...
A WARM AND HUMID AIR MASS CONTINUES TO IMPACT THE REGION THIS
MORNING INTO THE AFTERNOON. A WEAK MID LEVEL DISTURBANCE IN THE
W/SW FLOW ALOFT MAY PRODUCE ISOLD-SCT SHOWERS AND THUNDERSTORMS
IN THE LATE AFTERNOON. A COLD FRONT WILL INCREASE THE COVERAGE OF
SHOWERS AND THUNDERSTORMS WED NIGHT INTO THU.
THE CLEAR SKIES AND LIGHT TO CALM WINDS HAVE LET RADIATIONAL
MIST/FOG FORM AT KGFL/KPSF/KPOU. SOME LOW STRATUS IN THE LIFR/IFR
RANGE HAS ALSO OCCURRED AT KGFL/KPSF. MVFR MIST HAS OCCURRED AT
KALB. A GRADUAL IMPROVEMENT TO VFR LEVELS WILL OCCUR AT
KPOU/KPSF/KGFL BTWN 14Z-16Z. VFR CONDITIONS WILL OCCUR INTO THE
MID PM...AND THEN THAT MID LEVEL DISTURBANCE OR SFC TROUGH COULD
FOCUS THE ISOLD-SCT SHOWERS AND THUNDERSTORMS. VCSH GROUPS HAVE
BEEN USED AT THIS TIME. CIG BASES WILL BE IN THE 4-5 KFT AGL
RANGE.
THE SKIES SHOULD CLEAR A BIT AFTER 00Z/THU...THIS MAY ALLOW
FOR SOME PATCHY MIST/FG AGAIN...ESPECIALLY AT KPSF AND KGFL.
MVFR/IFR CONDITIONS HAVE BEEN PLACED IN THE TAF SITES AT THIS TIME.
THE WINDS WILL BE LIGHT AND VARIABLE AT LESS THAN 5 KTS AT ALL THE
TAF SITES...EXCEPT AT KALB WHERE A LIGHT S WIND OF 4-7 KTS WILL
CONTINUE THIS MORNING. THE WINDS WILL INCREASE FROM THE SOUTH TO
SOUTHWEST AT 8 TO 13 KTS DURING THE PM...WITH A FEW GUSTS AROUND
20-25 KTS AT KALB/KPSF. THE WINDS WILL LIGHTEN TO LESS THAN 7 KTS
AFTER 01Z/THU.
OUTLOOK...
THURSDAY NIGHT: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY TO SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY:LOW OPERATIONAL IMPACT. ISOLATED SHRA.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED ISSUES ARE ANTICIPATED OVER THE NEXT
SEVERAL DAYS.
HAZY...HOT AND HUMID CONDITIONS ARE IN STORE FOR OUR REGION TODAY
WITH A CHANCE FOR A SHOWER OR THUNDERSTORM. A STRONG COLD
FRONT...ACCOMPANIED BY WIDESPREAD SHOWERS AND THUNDERSTORMS WITH
HEAVY RAIN...WILL MOVE ACROSS THE REGION THURSDAY USHERING IN A
MUCH COOLER AND LESS HUMID AUTUMN AIR MASS FOR THE REMAINDER OF
THE WEEK.
&&
.HYDROLOGY...
WIDELY SCATTERED TO SCATTERED SHOWERS AND THUNDERSTORMS...SOME
WITH VERY HEAVY DOWNPOURS...ARE EXPECTED ACROSS THE HSA DURING THE
AFTERNOON AND EVENING HOURS TODAY LIKELY ASSOCIATED WITH A PRE
FRONTAL TROUGH. MORE WIDESPREAD CONVECTION IS EXPECTED LATE
TONIGHT INTO THURSDAY EVENING WITH HEAVY RAINFALL AS ONE OR MORE
WAVES OF LOW PRESSURE ARE EXPECTED TO TRACK NORTHEAST ALONG A
STRONG COLD FRONT WHICH WILL BE DROPPING SOUTHEAST THROUGH OUR
REGION LATE THURSDAY AND THURSDAY NIGHT. DRIER AND COOLER WEATHER
IS EXPECTED TO END THE WEEK
WITHIN ANY SHOWER OR THUNDERSTORM...THERE WILL BE THE POTENTIAL FOR
MINOR FLOODING OF POOR DRAINAGE...URBAN...AND LOW LYING AREAS DUE TO
VERY HEAVY RAINFALL IN A SHORT PERIOD OF TIME TODAY THROUGH
THIS EVENING. LATE TONIGHT THROUGH THURSDAY EVENING EXPECT A MORE
WIDESPREAD HEAVY RAIN EVENT WITH SIGNIFICANT RISES OCCURRING ON
SOME MAIN STEM RIVERS WITH UP TO SEVERAL INCHES OF RAIN POSSIBLE.
IN ADDITION FLOODING OF SMALL STREAMS AND CREEKS MAY ALSO OCCUR.
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...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR CTZ001-013.
NY...HEAT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR NYZ041-049-050-
052-053-059-060-064-065-083-084.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS/JPV
SHORT TERM...11
LONG TERM...WASULA
AVIATION...WASULA
FIRE WEATHER...11
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1026 AM EDT WED SEP 11 2013
.SYNOPSIS...
VERY WARM AND HUMID CONDITIONS WILL BE IN PLACE ACROSS THE
REGION THROUGH THURSDAY. A COLD FRONT WILL BRING SHOWERS AND
THUNDERSTORMS WITH GUSTY WINDS AND HEAVY RAIN THURSDAY AND
THURSDAY NIGHT...POSSIBLY LINGERING INTO FRIDAY MORNING ACROSS
EASTERN MASSACHUSETTS. HIGH PRESSURE RETURNS FOR THE WEEKEND WITH
DRY AND MUCH COOLER WEATHER. A WEAK COLD FRONT WILL MOVE THROUGH
ON MONDAY. HIGH PRESSURE BRINGS DRY WEATHER AFTERWARD.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1030 AM UPDATE...
*** EXCESSIVE HEAT AND HUMIDITY ***
*** A FEW STRONG STORMS POSSIBLE ***
ONLY CHANGE TO THE FORECAST WAS TO INTRODUCE THE CHANCE OF A FEW
STRONG STORMS LATE TODAY/THIS EVENING ACROSS WESTERN CT/MA AND
INTO SOUTHWEST NH. THIS LINES UP WELL WITH SPC LATEST SEVERE
WEATHER DAY1 OUTLOOK.
591 DAM MID LEVEL RIDGE PROVIDING A STRONG CAP/LID OVER THE
REGION THIS MORNING WITH LARGE SBCIN VALUES ACROSS SOUTHERN NEW
ENGLAND. HOWEVER WEAK HEIGHT FALLS LATER TODAY INTO THIS EVENING
ALONG WITH MID LEVEL FLOW BECOMING WEAKLY CYCLONIC WILL LIKELY
ERODE THIS CAP AND UNLEASH THE 2500-3500 J/KG OF CAPE THAT BUILDS
UP TODAY UNDER THE RIDGE.
GREATEST PROBABILITY FOR STORMS WILL BE OVER THE HIGHER TERRAIN OF
WESTERN CT/MA AND SOUTHWEST NH WHERE ELEVATED HEATING WILL
INCREASE THE RISK OF ERODING THE CAP. ALSO THIS AREA IS COLOCATED
WITH THE STRONGER DEEP LAYER SHEAR /ALBEIT MARGINAL/. IN ADDITION
REMNANT EML IS OVER THE AREA WITH MID LEVEL LAPSE RATES ON THE
ORDER OF 7-8C/KM. THIS WILL ENHANCE UPDRAFT POTENTIAL AND
CORRESPONDING STRONG DOWNDRAFTS/WIND THREAT.
FORECAST CONFIDENCE HAS INCREASED SOMEWHAT ON THIS SCENARIO AS
LAST FEW RUNS OF THE HRRR ALONG WITH 00Z ECMWF SIMULATE STORM
GENERATION OVER THE CATSKILLS AND POCONOS THIS AFTERNOON AND
TRAVERSE EASTWARD INTO WESTERN NEW ENGLAND THIS EVENING.
TIMING LOOKS TO BE AFTER 6 PM WESTERN CT/MA AND SOUTHWEST NH.
FARTHER EAST ACROSS RI AND EASTERN MA IT SHOULD REMAIN STORM-FREE
WITH MID LEVEL RIDGE LINGERING HOLDING THE CAP IN THE PLACE ALONG
WITH WEAKENING DEEP LAYER SHEAR.
GIVEN THE INCREASED FORECAST CONFIDENCE WE INSERTED INTO THE
FORECAST ENHANCED WORDING OF STRONG TO DAMAGING WINDS POSSIBLE
ALONG WITH LARGE HAIL AND HEAVY RAIN.
OTHERWISE FORECAST REMAINS ON TRACK WITH SUMMERTIME AIRMASS OVER
THE REGION. 925 MB TEMPS OF +25C/+26C AIRMASS ABOUT +3 STD WARMER
THAN CLIMO!
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
TONIGHT...
AS THE UPPER RIDGE STARTS TO SHIFT E TONIGHT...WILL SEE WINDS
START TO BACK TO SW AT THAT LEVEL AS THE HEIGHTS START TO FALL.
THIS MAY ALLOW FOR CONVECTION TO KICK OFF WITH SOME RELEASE OF ALL
THE DYNAMIC ENERGY WITH THE PASSING ELEVATED MIXED LAYER /EML/.
HOWEVER...LOOKS LIKE THE BEST LAPSE RATES PASS TO THE E BUT COULD
STILL SEE SOME STRONG CONVECTION...ALONG WITH HIGH CAPE VALUES.
WOULD BE BEST WITH DIURNAL INFLUENCES...BUT COULD SEE SOME HEAVY
RAIN AND GUSTY WINDS WITH THIS...PROBABLY AFTER MIDNIGHT. AGAIN...
WILL NEED TO MONITOR TODAY/S MODEL RUNS FOR TIMING AND POTENTIAL.
HAVE KEPT CHANCE POPS GOING ACROSS INLAND AREAS WHERE BEST
INSTABILITY OCCURS...WITH THE BEST SHOT ACROSS S NH/NW MA.
ANOTHER WARM AND MUGGY NIGHT EXPECTED WITH PATCHY FOG DEVELOPING.
OVERNIGHT LOWS IN THE MID 60S TO LOWER 70S.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
BIG PICTURE...
THURSDAY STARTS WITH A DIGGING UPPER TROUGH OVER THE GREAT LAKES AND
NORTHEAST USA WHILE UPPER RIDGE SITS OVER THE PLAINS AND NORTHERN
ROCKIES. THE NORTHEAST TROUGH LINGERS OVER NEW ENGLAND THROUGH
SATURDAY...THEN LIFTS OUT THROUGH THE MARITIMES ON SUNDAY. A
SHORTWAVE FROM THE ARCTIC COAST OF CANADA SWEEPS SOUTHEAST AND
ACROSS NEW ENGLAND EARLY NEXT WEEK MAINTAINING CYCLONIC FLOW OVER
THE REGION. THE PLAINS RIDGE THEN SHIFTS EAST AT THE END OF THE
FORECAST PERIOD SPREADING DRIER WEATHER OUR WAY.
THE DAILIES...
THURSDAY...SURFACE COLD FRONT DRIVEN EAST BY THE GREAT LAKES
UPPER TROUGH. THE COLD FRONT WILL CROSS NEW YORK STATE DURING THE
DAY. BY EVENING THE VARIOUS MODELS HAVE THE FRONT EITHER AT OR
NEAR THE NY/CT/MASS BORDER WITH SIGNS OF A PRE-FRONTAL SURFACE
TROUGH FARTHER EAST. JET DYNAMICS ARE FAVORABLE WITH UPPER
DIVERGENCE OVERLAYING LOW LEVEL CONVERGENCE. WIND FIELDS FROM 850
MB TO 500 MB ARE FAVORABLE WITH 40-50 KNOTS AT 500. INSTABILITY IS
PRESENT WITH SBCAPE INITIALLY FORECAST AT 2000-2500 J/KG IN A BAND
FROM SOUTHERN NH TO NORTHWEST CT...TOTALS AROUND 50. ALL OF THIS
SUPPORTS MAINTAINING LIKELY POPS FOR SHOWERS/TSTMS WITH THIS
FROPA...WITH POTENTIAL FOR STRONG WIND GUSTS FROM TSTMS.
PRECIPITABLE WATER VALUES AROUND 1.8 INCHES SUGGESTS HEAVY
DOWNPOURS AS WELL.
STRONGEST INSTABILITY AND PRE-FRONTAL TROUGH STARTING IN OUR WESTERN
AREAS...SO WE WILL FOCUS HIGHEST POPS IN THAT AREA INITIALLY AND
THEN SWEEP POPS EAST LATER IN THE DAY AND AT NIGHT AS THE COLD FRONT
ENTERS NEW ENGLAND AND SLOWLY MOVES ACROSS AT NIGHT. DAYTIME
HEATING/MIXING SHOULD REACH TO AT LEAST 850 MB. TEMPS AT THAT LEVEL
WILL BE 14-16C WHICH WOULD SUPPORT MAX TEMPS IN THE MID 80S. CLOUDS
MAY KEEP TEMPS A LITTLE LESS WARM THAN FULL POTENTIAL...SO FORECAST
WILL RANGE FROM UPPER 70S TO MID 80S. WINDS AT 850 MB WILL BE 20-25
KNOTS...SO WE WILL ALSO INCLUDE WIND GUSTS TO THOSE SPEEDS.
FRIDAY... THE DIGGING TROUGH TURNS THE UPPER FLOW OVER NEW ENGLAND
MORE SOUTHWEST AND PARALLEL TO THE SURFACE FRONT...PROVIDING LESS
PUSH ACROSS THE FRONT AND THUS SLOWING IT DOWN. MODEL CONSENSUS HAS
THE FRONT IN EASTERN MASS FRIDAY MORNING AND SLOWLY MOVING OFFSHORE
BY AFTERNOON. THIS WILL KEEP A CHANCE OF SHOWERS/TSTMS DURING THE
MORNING ESPECIALLY IN THE EAST. THIS CHANCE DIMINISHES AS THE FRONT
MOVES OFFSHORE. CLEARING BY MIDDAY WITH ALLOW DAYTIME HEATING...BUT
THE UPPER TROUGH AND ITS COLD POOL WILL BE MOVING OVERHEAD DURING
THE AFTERNOON WITH PLENTY OF COLD ADVECTION ALOFT DESTABILIZING THE
AIRMASS. THE RESULT SHOULD BE CUMULUS DEVELOPMENT AND SCATTERED
SHOWERS.
SATURDAY-SUNDAY... HIGH PRESSURE BUILDS OVER THE REGION. COULD BE
SOME LEFTOVER CUMULUS DEVELOPMENT ON SATURDAY...DUE TO THE LINGERING
PRESENCE OF THE UPPER TROUGH/COLD POOL. THIS MOVES OFF BY SUNDAY.
MONDAY... SHORTWAVE FROM NORTHERN CANADA DRIVES ANOTHER COLD FRONT
INTO NEW ENGLAND. LIMITED MOISTURE WITH THIS FRONT BUT ENOUGH TO
GO WITH SLIGHT CHANCE POPS DURING FROPA.
TUESDAY...
HIGH PRESSURE RETURNS WITH FAIR DRY WEATHER.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
1030 AM UPDATE...
TODAY...VFR CONDITIONS THROUGH THE DAY. LOW TO MODERATE RISK OF
SHOWERS/TSTMS AFTER 22Z ACROSS WESTERN NEW ENGLAND. EASTERN MA AND
RI SHOULD REMAIN STORM-FREE.
TONIGHT...CLOUDS AND PATCHY FOG REDEVELOP IN HUMID AIRMASS. SHOULD
SEE AREAS OF MVFR-IFR CIGS/VSBYS...WITH LOWEST CONDITIONS ACROSS
INTERIOR E AND S CENTRAL MA/MOST OF IR INTO NE CT. HIGH
UNCERTAINTY FOR DEVELOPMENT OF CONVECTION. IF ANY TSTMS DEVELOP...
BEST LOCATIONS ACROSS S NH/N CENTRAL AND W MA/N CENTRAL CT.
STRONG WIND AND HEAVY RAINFALL POSSIBLE ALONG WITH LOCAL IFR
CONDITIONS.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. MVFR VSBYS IMPROVE TO
VFR. VFR TODAY INTO EARLY TONIGHT. LOW CHANCE OF A THUNDERSTORM
AFTER MIDNIGHT. MVFR-IFR CONDITIONS POSSIBLE IN FOG AFTER 08Z.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. IFR VSBYS EARLY
IMPROVING TO VFR TODAY. LOW CHANCE OF A THUNDERSTORM THIS EVENING
AND TONIGHT. MVFR VSBYS IN PATCHY FOG POSSIBLE AFTER 06Z.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY...AREAS OF IFR CIGS/VSBYS IN MORNING FOG. OTHERWISE VFR
WITH BRIEFLY LOWER CONDITIONS IN DEVELOPING SHOWERS/TSTMS ESPECIALLY
IN THE AFTERNOON AND AT NIGHT. SOUTHWEST WINDS WILL GUST TO 25 KNOTS
IN THE AFTERNOON. SOME THUNDERSTORMS WILL HAVE STRONGER WIND GUSTS
AS WELL AS HEAVY DOWNPOURS.
FRIDAY...COLD FRONT MOVES OFFSHORE IN THE MORNING AND WINDS WILL
SHIFT NORTHWEST WITH GUSTS TO 20 KNOTS. MORNING SHOWERS/TSTMS
ESPECIALLY IN EASTERN MASS AND RI. CLEARING AROUND MIDDAY WITH MORE
CLOUDS/SCATTERED SHOWERS DEVELOPING IN THE AFTERNOON ESPECIALLY
NORTH OF THE MASS TURNPIKE.
SATURDAY-SUNDAY...VFR AS HIGH PRESSURE BUILDS OVERHEAD. COULD BE
SOME LINGERING CLOUDS SATURDAY BUT GENERALLY VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE.
TODAY...SW WINDS GUSTING UP TO 20 KT. PATCHY FOG WILL DISSIPATE BY
MID MORNING. SMALL CRAFT FOR 5 FOOT SEAS ON OUTER WATERS.
TONIGHT...SW WINDS CONTINUE WITH SEAS AROUND 5 FT ON THE OUTER
WATERS. ISOLD SHOWERS/TSTMS POSSIBLE ON EASTERN WATERS. PATCHY FOG
LIMITING VSBY. S-SE SWELLS BEGIN TO INCREASE FROM TS GABRIELLE.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THURSDAY...INCREASING CHANCE OF SHOWERS/TSTMS THROUGH THE DAY AND AT
NIGHT AS A COLD FRONT APPROACHES FROM THE WEST. SOUTHWEST WINDS AT
5000 FEET ABOVE THE SURFACE REACH 30 KNOTS...AND WE EXPECT MUCH OF
THIS TO REACH THE SURFACE BY AFTERNOON ESPECIALLY CLOSE TO LAND.
SMALL CRAFT ADVISORY WILL CONTINUE THROUGH THE DAY. IN
ADDITION...THE SOUTHWEST WIND WILL DRIVE 5-6 FOOT SEAS ON THE
EXPOSED WATERS.
FRIDAY... COLD FRONT MOVES OFFSHORE IN THE MORNING. WINDS WILL TURN
NORTHWEST WITH GUSTS IN THE LOW 20S. THERE IS A LOW CHANCE THAT
WINDS COULD REACH 25 KNOTS. LINGERING 5-6 FOOT SEAS...MAINLY ON THE
SOUTHERN AND SOUTHEAST OUTER WATERS.
SATURDAY-SUNDAY...HIGH PRESSURE BUILDS OVER NEW ENGLAND OVER THE
WEEKEND. THIS WILL BRING DIMINISHING WINDS AND SEAS. COULD BE A
FEW LINGERING 20 KNOT GUSTS AND 5 FOOT SEAS FIRST THING SATURDAY BUT
THE TREND WILL BE LOWER THROUGH THE DAY.
&&
.CLIMATE...
RECORD MAX TEMPS FOR WED 9/11...
BOS 99/1983
PVD 100/1983
BDL 99/1983
ORH 91/1983
90S IN SEPTEMBER? WELL...YES. BOS AND BDL HAVE EVEN HAD THEM IN
OCTOBER.
LATEST MAX TEMP OF 90 OR HIGHER...
BOS OCTOBER 12 1954
PVD SEPTEMBER 23 1970
BDL OCTOBER 17 1908
ORH SEPTEMBER 26 1930
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR CTZ002>004.
MA...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 6 PM EDT THIS
EVENING FOR MAZ005>007-013>019.
AIR QUALITY ALERT UNTIL 11 PM EDT THIS EVENING FOR MAZ007-
010>012-014.
NH...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 6 PM EDT THIS
EVENING FOR NHZ012.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM NOON TO 6 PM EDT THURSDAY FOR
ANZ231>234-251.
SMALL CRAFT ADVISORY FROM 2 PM TO 6 PM EDT THURSDAY FOR ANZ230-
236.
SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT THURSDAY FOR ANZ235-
237.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ250-
254>256.
&&
$$
SYNOPSIS...WTB/EVT
NEAR TERM...NOCERA
SHORT TERM...EVT
LONG TERM...WTB
AVIATION...WTB/NOCERA/EVT
MARINE...WTB/EVT
CLIMATE...
AREA FORECAST DISCUSSION
NWS ALBANY NY
159 AM EDT WED SEP 11 2013
.SYNOPSIS...
IN THE WAKE OF A WARM FRONT...CLOUDS WILL CONTINUE TO
BREAK UP OVER THE REGION THIS EVENING WITH MILDER AND MUGGY WEATHER
IN PLACE. HOT TEMPERATURES ARE EXPECTED TOMORROW WITH PARTIAL
SUNSHINE...HUMID CONDITIONS...AND A CHANCE FOR A SHOWER OR
THUNDERSTORM. A STRONG COLD FRONT...ACCOMPANIED BY WIDESPREAD
SHOWERS AND THUNDERSTORMS...WILL MOVE ACROSS THE REGION THURSDAY
USHERING IN A MUCH COOLER AND LESS HUMID AUTUMN AIR MASS FOR THE
REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1215 AM EDT...MAINLY CLEAR SKIES AND MUGGY CONDITIONS
ACROSS THE REGION. THERE HAS BEEN AN INCREASE IN LOW CLOUDS/FOG
PER THE 11U-3.9U ENHANCED IR SATELLITE IMAGERY THIS EVENING COMING
DOWN THE CHAMPLAIN VALLEY AND ADDITIONAL FOG/STRATUS ALONG WITH
HAZE IS EXPECTED OVERNIGHT. HAVE RAISED OVERNIGHT LOWS A COUPLE OF
DEGREES IN SEVERAL LOCATIONS...EXCEPT FOR LAKE GEORGE AND GLENS
FALLS REGIONS WHERE WE LOWERED THEM A BIT MORE PER OBSERVATIONS
AND MESONET OBS. OVERNIGHT LOWS ARE EXPECTED TO RANGE FROM THE MID
60S TO MID 70S.
00Z SOUNDINGS WERE QUITE UNSTABLE IN THE MID LEVELS BUT WITH A LACK
OF A TRIGGER IN THE H2O VAPOR AND HOURLY RUC ANALYSIS...CONTINUED
WITH A DRY FORECAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
OUR REGION WILL FIRMLY BE IN THE WARM SECTOR TOMORROW. AFTER ANY
MORNING FOG BREAKS UP...PARTIAL SUNSHINE ALONG WITH 850 HPA TEMPS
OF AROUND 20 DEGREES C WILL YIELD MAX TEMPS IN VALLEY AREAS TO
REACH AROUND 90 DEGREES...WITH 80S ACROSS THE HIGH TERRAIN.
THERE WON/T BE MUCH OF A LARGE SCALE FORCING MECHANISM FOR
SHOWER/THUNDERSTORM DEVELOPMENT TOMORROW...BUT THERE STILL
PROBABLY WILL BE ISOLD TO SCT THUNDERSTORMS DURING THE AFTN AND
EVENING HOURS THANKS TO A PRE FRONTAL TROUGH AND/OR TERRAIN
FORCING. WITH THE WARM AND MUGGY AIR MASS IN PLACE...INSTABILITY
WILL BE HIGH /SBCAPE VALUES ARE PROJECTED TO BE WELL OVER 2000
J/KG/ AND 0-6 KM BULK SHEAR VALUES OF 20-35 KTS LOOK TO BE MORE
THAN SUFFICIENT FOR STORMS TO DEVELOP AND ORGANIZE. SPC HAS PLACED
MUCH OF OUR AREA IN A SLIGHT RISK FOR SVR STORMS AND WE WILL
LIKELY NEED TO MONITOR ANY CONVECTION VERY CLOSELY. DAMAGING WINDS
WOULD BE THE PRIMARY THREAT WITH ANY STORMS. IN ADDITION...HIGH
PWATS/DEWPOINTS WILL ALLOW FOR HVR DOWNPOURS WITHIN ANY T-STORM.
THE THREAT FOR CONVECTION WILL CONTINUE INTO WED NIGHT AS AN
UPSTREAM TROUGH OVER THE GREAT LAKES AND ASSOCIATED SFC COLD FRONT
BEGINS TO HEAD TOWARDS OUR AREA. IT WILL REMAIN MUGGY AND WARM ALL
NIGHT WITH MINS IN THE MID 60S TO NEAR 70...STICKY
CONDITIONS...AND A MOSTLY CLOUDY SKY. THE MAIN THREAT WILL BE ACROSS
THE FAR NORTHWESTERN PART OF THE CWA.
ON THURSDAY INTO THURSDAY NIGHT...THE COLD FRONT WILL BE MOVING
ACROSS OUR AREA...PROVIDING PLENTY OF FORCING FOR LIFT.
INSTABILITY WON/T BE AS ROBUST AS WEDNESDAY THANKS TO MORE CLOUD
COVER...BUT THE STRONG FORCING SHOULD BE ENOUGH TO ALLOW FOR A FEW
LINES OF SHOWERS AND THUNDERSTORMS TO MOVE FROM WEST TO EAST
ACROSS THE AREA. WE WILL GO WITH LIKELY POPS FOR
SHOWERS/THUNDERSTORMS FOR THURSDAY INTO THURSDAY EVENING. SPC HAS
A PORTION OF OUR AREA IN SLIGHT RISK FOR SVR STORMS AGAIN ON
THURSDAY AS WELL. POPS WILL LOWER THURSDAY NIGHT FROM WEST TO EAST
WITH THE PASSAGE OF THE SFC BOUNDARY...WHICH WILL START TO BRING
LESS HUMID AIR INTO THE REGION. TEMPS ON THURSDAY LOOK TO BE IN
THE LOW 80S FOR VALLEY AREAS...WITH MINS IN THE 50S AND 60S FOR
THURS NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
A RATHER PROGRESSIVE AND AMPLIFIED PATTERN IS EXPECTED FOR THE LONG
TERM PORTION OF THIS FORECAST AS SEVERAL PERTURBATIONS WITHIN THE
NORTHWEST FLOW REGIME WILL IMPACT OUR REGION.
WE BEGIN WITH FRIDAY AS THE MAIN COLD FRONT AND MOISTURE IS EXPECTED
TO BE EAST OF THE REGION AS WE ARE LEFT WITH A CYCLONIC
FLOW/EMBEDDED UPPER LOW OVER THE EASTERN GREAT LAKES AND NEW
ENGLAND. AS THOSE H850 TEMPS DROP BACK INTO THE LOWER SINGLE
DIGITS...THIS WILL ALLOW FOR LAKE CONTRIBUTIONS TO INCREASE AS WELL
AS THE CHC-SCT SHOWERS MAINLY ACROSS THE HIGHER TERRAIN. AS
CONSIDERABLE CLOUD COVER IS EXPECTED AND MAINLY TERRAIN BASED...WE
WILL SEE HIGH TEMPERATURES MUCH COOLER WITH MAINLY 60S...SOME 50S
FOR THE HIGHER TERRAIN AND ACROSS THE ADIRONDACKS.
THE LOSS OF DIURNAL HEATING WILL RESULT IN A DECREASE IN CLOUDS AND
SHOWERS FRIDAY EVENING. HOWEVER...THE MAIN UPPER LOW IS EXPECTED TO
REMAIN RATHER SLOW MOVING PER THE GLOBAL MODEL CONSENSUS WHICH WILL
SET THE STAGE FOR ANOTHER ROUND OF TERRAIN BASED CLOUD COVER DURING
SATURDAY. THERE IS SOME QUESTION ON JUST HOW MUCH INSTABILITY WILL
BE AROUND FOR SHOWERS AS WE WILL KEEP POPS JUST BELOW SLIGHT CHANCE
AS TRENDS PER THE DPROG/DT FAVOR A DRIER SOLUTION AT THIS TIME.
HIGHS REMAIN BELOW NORMAL WITH MAINLY 50S ACROSS THE TERRAIN AND
LOWER HALF OF THE 60S FOR VALLEY LOCATIONS.
ANOTHER FAST MOVING DISTURBANCE IN THE NORTHWEST FLOW REGIME IS
FORECAST TO APPROACH LATE SUNDAY INTO SUNDAY NIGHT. MOISTURE ALONG
THIS BOUNDARY REMAINS LIMITED BUT LAKE MOISTURE CONTRIBUTION WILL
ADD THE CHANCE FOR SOME SHOWERS MAINLY NORTH AND WEST OF ALBANY.
WINDS ARE EXPECTED TO INCREASE IN THE WAKE OF THE FROPA ON MONDAY AS
THOSE H850 TEMPS DROP BACK INTO THE LOWER SINGLE DIGITS AS A LARGE
CANADIAN HIGH PRESSURE SYSTEM MOVES ACROSS THE GREAT LAKES REGION.
HIGHS WILL REMAIN IN THE 60S.
OVERALL...PCPN AND TEMPS LOOK BELOW NORMAL IN THE EXTEND FORECAST
PERIOD.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A WARM AND HUMID AIR MASS CONTINUES TO IMPACT THE REGION THIS
MORNING INTO THE AFTERNOON. A WEAK MID LEVEL DISTURBANCE IN THE
W/SW FLOW ALOFT MAY PRODUCE ISOLD-SCT SHOWERS AND THUNDERSTORMS
IN THE LATE AFTERNOON. A COLD FRONT WILL INCREASE THE COVERAGE OF
SHOWERS AND THUNDERSTORMS WED NIGHT INTO THU.
THE CLEAR SKIES AND LIGHT TO CALM WINDS HAVE LET RADIATIONAL
MIST/FOG FORM AT KGFL/KPSF/KPOU. SOME LOW STRATUS IN THE LIFR/IFR
RANGE IS ALSO LIKELY. THE FOG WILL BECOME DENSER BTWN 08Z-14Z.
KALB CONTINUES TO HAVE A LIGHT SOUTHERLY WIND...BUT A BRIEF PERIOD
OF MVFR VSBYS/CIGS IS POSSIBLE BTWN 08-12Z...AND A TEMPO GROUP HAS
BEEN USED TO ADDRESS THIS POSSIBILITY.
A GRADUAL IMPROVEMENT TO VFR LEVELS WILL OCCUR AT KPOU/KPSF/KGFL
BTWN 14Z-16Z. VFR CONDITIONS WILL OCCUR INTO THE MID PM...AND THEN
THAT MID LEVEL DISTURBANCE OR SFC TROUGH COULD FOCUS THE ISOLD-SCT
SHOWERS AND THUNDERSTORMS. VCSH GROUPS HAVE BEEN USED AT THIS
TIME. CIG BASES WILL BE IN THE 4-5 KFT AGL RANGE. THE SKIES SHOULD
CLEAR A BIT AFTER 00Z/THU...THIS MAY ALLOW FOR SOME PATCH MIST
AGAIN...ESPECIALLY AT KPSF AND KGFL.
THE WINDS WILL BE LIGHT AND VARIABLE AT LESS THAN 5 KTS AT ALL THE
TAF SITES...EXCEPT AT KALB WHERE A LIGHT S WIND OF 4-7 KTS WILL
CONTINUE THIS MORNING. THE WINDS WILL INCREASE FROM THE SOUTH TO
SOUTHWEST AT 8 TO 13 KTS DURING THE PM...WITH A FEW GUSTS AROUND
20-25 KTS AT KALB/KPSF. THE WINDS WILL LIGHTEN TO LESS THAN 7 KTS
AFTER 01Z/THU.
OUTLOOK...
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
FRIDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY TO SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED ISSUES ARE ANTICIPATED OVER THE NEXT
SEVERAL DAYS.
A WARM FRONT WILL CONTINUE TO MOVE THROUGH THE REGION THIS
EVENING...BRING MUGGY CONDITIONS IN ITS WAKE. THERE WILL BE A THREAT
FOR SHOWERS AND THUNDERSTORMS TOMORROW AND ESPECIALLY AGAIN ON
THURSDAY AS OUR REGION WILL BE IN A WARM AND MUGGY AIR MASS AHEAD OF
AN APPROACHING COLD FRONT. RH VALUES WILL BE HIGH AT NIGHT...NEARLY
100 PERCENT AT TIMES. RH VALUES WILL ONLY DROP TO 50 TO 60 PERCENT
DURING THE DAYTIME HOURS.
&&
.HYDROLOGY...
THERE WILL BE A THREAT FOR SHOWERS AND THUNDERSTORMS OVER THE
SEVERAL DAYS. OUR REGION WILL BE IN A WARM SECTOR TOMORROW BEFORE
A STRONG COLD FRONT MOVES THROUGH ON THURSDAY. PWAT VALUES WILL
BE QUITE HIGH OVER THE NEXT FEW DAYS...WITH PWAT VALUES 1.50 TO
2.00 INCHES. THIS WILL ALLOW FOR ANY SHOWER OR THUNDERSTORM TO BE
CAPABLE OF PRODUCING VERY HEAVY RAINFALL IN A SHORT PERIOD OF
TIME. THUNDERSTORMS LOOK TO BE MOST WIDESPREAD ON THURSDAY AHEAD OF
THE ADVANCING COLD FRONT. THE THREAT FOR HEAVY SHOWERS AND
THUNDERSTORMS WILL END WITH THE PASSAGE OF THE COLD FRONT LATE
THURSDAY...WITH MUCH DRIER AND LESS HUMID WEATHER FOR THE LATE
WEEK PERIOD.
WITHIN ANY SHOWER OR THUNDERSTORM...THERE WILL BE THE POTENTIAL FOR
MINOR FLOODING OF POOR DRAINAGE...URBAN...AND LOW LYING AREAS DUE TO
VERY HEAVY RAINFALL IN A SHORT PERIOD OF TIME. WHILE WIDESPREAD MAIN
STEM RIVER FLOODING IS NOT ANTICIPATED OVER THE NEXT FEW
DAYS...THERE WILL BE SOME POTENTIAL FOR FLOODING OF SMALL CREEKS AND
STREAMS DUE TO THE THUNDERSTORM ACTIVITY.
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...FRUGIS
NEAR TERM...FRUGIS/BGM/11
SHORT TERM...FRUGIS
LONG TERM...BGM
AVIATION...WASULA
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1221 AM EDT WED SEP 11 2013
.SYNOPSIS...
IN THE WAKE OF A WARM FRONT...CLOUDS WILL CONTINUE TO
BREAK UP OVER THE REGION THIS EVENING WITH MILDER AND MUGGY WEATHER
IN PLACE. HOT TEMPERATURES ARE EXPECTED TOMORROW WITH PARTIAL
SUNSHINE...HUMID CONDITIONS...AND A CHANCE FOR A SHOWER OR
THUNDERSTORM. A STRONG COLD FRONT...ACCOMPANIED BY WIDESPREAD
SHOWERS AND THUNDERSTORMS...WILL MOVE ACROSS THE REGION THURSDAY
USHERING IN A MUCH COOLER AND LESS HUMID AUTUMN AIR MASS FOR THE
REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1215 AM EDT...MAINLY CLEAR SKIES AND MUGGY CONDITIONS
ACROSS THE REGION. THERE HAS BEEN AN INCREASE IN LOW CLOUDS/FOG
PER THE 11U-3.9U ENHANCED IR SATELLITE IMAGERY THIS EVENING COMING
DOWN THE CHAMPLAIN VALLEY AND ADDITIONAL FOG/STRATUS ALONG WITH
HAZE IS EXPECTED OVERNIGHT. HAVE RAISED OVERNIGHT LOWS A COUPLE OF
DEGREES IN SEVERAL LOCATIONS...EXCEPT FOR LAKE GEORGE AND GLENS
FALLS REGIONS WHERE WE LOWERED THEM A BIT MORE PER OBSERVATIONS
AND MESONET OBS. OVERNIGHT LOWS ARE EXPECTED TO RANGE FROM THE MID
60S TO MID 70S.
00Z SOUNDINGS WERE QUITE UNSTABLE IN THE MID LEVELS BUT WITH A LACK
OF A TRIGGER IN THE H2O VAPOR AND HOURLY RUC ANALYSIS...CONTINUED
WITH A DRY FORECAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
OUR REGION WILL FIRMLY BE IN THE WARM SECTOR TOMORROW. AFTER ANY
MORNING FOG BREAKS UP...PARTIAL SUNSHINE ALONG WITH 850 HPA TEMPS
OF AROUND 20 DEGREES C WILL YIELD MAX TEMPS IN VALLEY AREAS TO
REACH AROUND 90 DEGREES...WITH 80S ACROSS THE HIGH TERRAIN.
THERE WON/T BE MUCH OF A LARGE SCALE FORCING MECHANISM FOR
SHOWER/THUNDERSTORM DEVELOPMENT TOMORROW...BUT THERE STILL
PROBABLY WILL BE ISOLD TO SCT THUNDERSTORMS DURING THE AFTN AND
EVENING HOURS THANKS TO A PRE FRONTAL TROUGH AND/OR TERRAIN
FORCING. WITH THE WARM AND MUGGY AIR MASS IN PLACE...INSTABILITY
WILL BE HIGH /SBCAPE VALUES ARE PROJECTED TO BE WELL OVER 2000
J/KG/ AND 0-6 KM BULK SHEAR VALUES OF 20-35 KTS LOOK TO BE MORE
THAN SUFFICIENT FOR STORMS TO DEVELOP AND ORGANIZE. SPC HAS PLACED
MUCH OF OUR AREA IN A SLIGHT RISK FOR SVR STORMS AND WE WILL
LIKELY NEED TO MONITOR ANY CONVECTION VERY CLOSELY. DAMAGING WINDS
WOULD BE THE PRIMARY THREAT WITH ANY STORMS. IN ADDITION...HIGH
PWATS/DEWPOINTS WILL ALLOW FOR HVR DOWNPOURS WITHIN ANY T-STORM.
THE THREAT FOR CONVECTION WILL CONTINUE INTO WED NIGHT AS AN
UPSTREAM TROUGH OVER THE GREAT LAKES AND ASSOCIATED SFC COLD FRONT
BEGINS TO HEAD TOWARDS OUR AREA. IT WILL REMAIN MUGGY AND WARM ALL
NIGHT WITH MINS IN THE MID 60S TO NEAR 70...STICKY
CONDITIONS...AND A MOSTLY CLOUDY SKY. THE MAIN THREAT WILL BE ACROSS
THE FAR NORTHWESTERN PART OF THE CWA.
ON THURSDAY INTO THURSDAY NIGHT...THE COLD FRONT WILL BE MOVING
ACROSS OUR AREA...PROVIDING PLENTY OF FORCING FOR LIFT.
INSTABILITY WON/T BE AS ROBUST AS WEDNESDAY THANKS TO MORE CLOUD
COVER...BUT THE STRONG FORCING SHOULD BE ENOUGH TO ALLOW FOR A FEW
LINES OF SHOWERS AND THUNDERSTORMS TO MOVE FROM WEST TO EAST
ACROSS THE AREA. WE WILL GO WITH LIKELY POPS FOR
SHOWERS/THUNDERSTORMS FOR THURSDAY INTO THURSDAY EVENING. SPC HAS
A PORTION OF OUR AREA IN SLIGHT RISK FOR SVR STORMS AGAIN ON
THURSDAY AS WELL. POPS WILL LOWER THURSDAY NIGHT FROM WEST TO EAST
WITH THE PASSAGE OF THE SFC BOUNDARY...WHICH WILL START TO BRING
LESS HUMID AIR INTO THE REGION. TEMPS ON THURSDAY LOOK TO BE IN
THE LOW 80S FOR VALLEY AREAS...WITH MINS IN THE 50S AND 60S FOR
THURS NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
A RATHER PROGRESSIVE AND AMPLIFIED PATTERN IS EXPECTED FOR THE LONG
TERM PORTION OF THIS FORECAST AS SEVERAL PERTURBATIONS WITHIN THE
NORTHWEST FLOW REGIME WILL IMPACT OUR REGION.
WE BEGIN WITH FRIDAY AS THE MAIN COLD FRONT AND MOISTURE IS EXPECTED
TO BE EAST OF THE REGION AS WE ARE LEFT WITH A CYCLONIC
FLOW/EMBEDDED UPPER LOW OVER THE EASTERN GREAT LAKES AND NEW
ENGLAND. AS THOSE H850 TEMPS DROP BACK INTO THE LOWER SINGLE
DIGITS...THIS WILL ALLOW FOR LAKE CONTRIBUTIONS TO INCREASE AS WELL
AS THE CHC-SCT SHOWERS MAINLY ACROSS THE HIGHER TERRAIN. AS
CONSIDERABLE CLOUD COVER IS EXPECTED AND MAINLY TERRAIN BASED...WE
WILL SEE HIGH TEMPERATURES MUCH COOLER WITH MAINLY 60S...SOME 50S
FOR THE HIGHER TERRAIN AND ACROSS THE ADIRONDACKS.
THE LOSS OF DIURNAL HEATING WILL RESULT IN A DECREASE IN CLOUDS AND
SHOWERS FRIDAY EVENING. HOWEVER...THE MAIN UPPER LOW IS EXPECTED TO
REMAIN RATHER SLOW MOVING PER THE GLOBAL MODEL CONSENSUS WHICH WILL
SET THE STAGE FOR ANOTHER ROUND OF TERRAIN BASED CLOUD COVER DURING
SATURDAY. THERE IS SOME QUESTION ON JUST HOW MUCH INSTABILITY WILL
BE AROUND FOR SHOWERS AS WE WILL KEEP POPS JUST BELOW SLIGHT CHANCE
AS TRENDS PER THE DPROG/DT FAVOR A DRIER SOLUTION AT THIS TIME.
HIGHS REMAIN BELOW NORMAL WITH MAINLY 50S ACROSS THE TERRAIN AND
LOWER HALF OF THE 60S FOR VALLEY LOCATIONS.
ANOTHER FAST MOVING DISTURBANCE IN THE NORTHWEST FLOW REGIME IS
FORECAST TO APPROACH LATE SUNDAY INTO SUNDAY NIGHT. MOISTURE ALONG
THIS BOUNDARY REMAINS LIMITED BUT LAKE MOISTURE CONTRIBUTION WILL
ADD THE CHANCE FOR SOME SHOWERS MAINLY NORTH AND WEST OF ALBANY.
WINDS ARE EXPECTED TO INCREASE IN THE WAKE OF THE FROPA ON MONDAY AS
THOSE H850 TEMPS DROP BACK INTO THE LOWER SINGLE DIGITS AS A LARGE
CANADIAN HIGH PRESSURE SYSTEM MOVES ACROSS THE GREAT LAKES REGION.
HIGHS WILL REMAIN IN THE 60S.
OVERALL...PCPN AND TEMPS LOOK BELOW NORMAL IN THE EXTEND FORECAST
PERIOD.
&&
.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
HAZE AND FOG WILL IMPACT FLIGHT CONDITIONS TONIGHT AS MOST OF THE
CLOUDS HAVE EXITED OR DISSIPATED ACROSS THE TAF SITES.
HOWEVER...ENHANCEMENT OF THE IR SATELLITE IMAGERY DOES REVEAL SOME
LOWER CLOUDS ACROSS WESTERN NEW ENGLAND. AS DEWPOINT DEPRESSIONS
CONTINUE TO COLLAPSE...EXPECTATIONS ARE FOR SOME IFR CONDITIONS TO
DEVELOP AND HAVE PLACED THIS INTO THE TAFS OVERNIGHT. A LIGHT
SOUTHERLY WIND WILL PERSIST AND INCREASE THROUGH THE DAYLIGHT
HOURS WEDNESDAY WHICH WILL IMPROVE FLIGHT CONDITIONS TO VFR.
THE CHANCE FOR SOME ISO-SCT CONVECTION INCREASES IN THE AFTERNOON
AND HAVE PLACE VCSH AT THIS TIME.
OUTLOOK...
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
THURSDAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
FRIDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER RELATED ISSUES ARE ANTICIPATED OVER THE NEXT
SEVERAL DAYS.
A WARM FRONT WILL CONTINUE TO MOVE THROUGH THE REGION THIS
EVENING...BRING MUGGY CONDITIONS IN ITS WAKE. THERE WILL BE A THREAT
FOR SHOWERS AND THUNDERSTORMS TOMORROW AND ESPECIALLY AGAIN ON
THURSDAY AS OUR REGION WILL BE IN A WARM AND MUGGY AIR MASS AHEAD OF
AN APPROACHING COLD FRONT. RH VALUES WILL BE HIGH AT NIGHT...NEARLY
100 PERCENT AT TIMES. RH VALUES WILL ONLY DROP TO 50 TO 60 PERCENT
DURING THE DAYTIME HOURS.
&&
.HYDROLOGY...
THERE WILL BE A THREAT FOR SHOWERS AND THUNDERSTORMS OVER THE
SEVERAL DAYS. OUR REGION WILL BE IN A WARM SECTOR TOMORROW BEFORE
A STRONG COLD FRONT MOVES THROUGH ON THURSDAY. PWAT VALUES WILL
BE QUITE HIGH OVER THE NEXT FEW DAYS...WITH PWAT VALUES 1.50 TO
2.00 INCHES. THIS WILL ALLOW FOR ANY SHOWER OR THUNDERSTORM TO BE
CAPABLE OF PRODUCING VERY HEAVY RAINFALL IN A SHORT PERIOD OF
TIME. THUNDERSTORMS LOOK TO BE MOST WIDESPREAD ON THURSDAY AHEAD OF
THE ADVANCING COLD FRONT. THE THREAT FOR HEAVY SHOWERS AND
THUNDERSTORMS WILL END WITH THE PASSAGE OF THE COLD FRONT LATE
THURSDAY...WITH MUCH DRIER AND LESS HUMID WEATHER FOR THE LATE
WEEK PERIOD.
WITHIN ANY SHOWER OR THUNDERSTORM...THERE WILL BE THE POTENTIAL FOR
MINOR FLOODING OF POOR DRAINAGE...URBAN...AND LOW LYING AREAS DUE TO
VERY HEAVY RAINFALL IN A SHORT PERIOD OF TIME. WHILE WIDESPREAD MAIN
STEM RIVER FLOODING IS NOT ANTICIPATED OVER THE NEXT FEW
DAYS...THERE WILL BE SOME POTENTIAL FOR FLOODING OF SMALL CREEKS AND
STREAMS DUE TO THE THUNDERSTORM ACTIVITY.
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...FRUGIS
NEAR TERM...FRUGIS/BGM/11
SHORT TERM...FRUGIS
LONG TERM...BGM
AVIATION...IAA/BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1134 PM EDT THU SEP 12 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BE IN THE FORECAST AREA FRIDAY. COOLER
WEATHER WILL OCCUR BEHIND THE FRONT SATURDAY AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
ISOLATED SHOWERS DEVELOPING OVER EAST MIDLANDS. HRRR GUIDANCE
SUGGESTS A FEW SHOWERS POSSIBLE OVERNIGHT. POPS REMAIN LOW HOWEVER
WITH WEAK FORCING AS FRONT APPROACHES. RAISED POPS FROM PREVIOUS
FORECAST MAINLY CENTRAL AND NORTH MIDLANDS DURING THE EARLY
MORNING HOURS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS THE UPPER TROUGH MOVES ACROSS NEW ENGLAND AND THE MID-ATLANTIC
STATES A COLD FRONT WILL PUSH SOUTHEASTWARD THROUGH THE FORECAST
AREA FRIDAY AFTERNOON. AGAIN MOISTURE IS NOT IDEAL BUT SOME
POOLING OF MOISTURE AHEAD OF THE FRONT IS EXPECTED AND THERE
SHOULD BE ENOUGH INSTABILITY FROM DAYTIME HEATING ALONG WITH LOW-
LEVEL CONVERGENCE ALONG THE FRONTAL BOUNDARY TO WARRANT LOW CHANCE
POPS ALONG AND AHEAD OF THE FRONT. WITH LIMITED MOISTURE...WILL
CARRY A 20 PERCENT POP EVERYWHERE MAINLY FRIDAY IN THE AFTERNOON.
FRIDAY HIGHS ARE EXPECTED TO BE AROUND THE 90 DEGREE MARK. THE
CHANCE OF SHOWERS AND STORMS WILL DIMINISH FROM THE NORTHWEST AS
THE FRONT PUSHES THROUGH AND COOLER...DRIER AIR BUILDS INTO THE
AREA. WEAK COLD ADVECTION WILL ALLOW TEMPERATURES TO FALL INTO THE
LOWER TO MID 60S FRIDAY NIGHT. COOLER SATURDAY WITH DRY HIGH
PRESSURE. HIGHS SATURDAY FROM THE UPPER 70S NORTH TO LOWER 80S
SOUTH. LOWS SATURDAY NIGHT FROM THE MIDDLE 50S NORTH TO UPPER 50S
SOUTH.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT SUNDAY AS SIGNIFICANT
MID LEVEL SHORT WAVE MOVES EAST AND SUPPRESSES WESTERN EXTENSION
OF BERMUDA RIDGE TO THE SOUTH TO NEAR THE GULF COAST REGION. BY
MONDAY AND TUESDAY...THE MAJOR UPPER TROUGH IS RE-ESTABLISH ALONG
THE EAST COAST. SOME MODEL DIFFERENCES MONDAY AND TUESDAY AS UPPER
TROUGH ALLOWS A WEAK COLD FRONT TO DROP TO THE SOUTH INTO THE
CAROLINAS. GFS BRINGS ENOUGH MOISTURE FOR ABOUT A 20 PERCENT CHANCE
OF PRECIPITATION WHILE THE ECMWF LOOKS DRIER. DECIDED TO GO WITH
CURRENT DRIER FORECAST WITH NO POPS. AT ANY RATE...MORE FALL-LIKE
SUNDAY WITH HIGHS ONLY IN THE LOWER 80S. WITH SOME UPPER HEIGHT
RISES MONDAY AND TUESDAY...THE MIDDLE 80S LOOKED BETTER. LOWS IN
THE UPPER 50S SUNDAY NIGHT ALSO INCREASE TO THE LOWER 60S MONDAY
NIGHT.
WEDNESDAY THROUGH THURSDAY...MORE MODEL DIFFERENCES LATE IN THE
PERIOD. GFS TRIES TO BUILD UPPER RIDGE TOWARD THE EAST WEDNESDAY
AND THURSDAY AND GIVES WARMER HIGH TEMPERATURES IN THE UPPER 80S.
ON THE OTHER HAND...ECMWF HAS UPPER RIDGE MORE SUPPRESSED AS A
STRONGER NORTHERN STREAM SHORT WAVE MOVES EASTWARD TOWARD THE
GREAT LAKES. THE WEAK COLD FRONT SHOULD STILL BE IN THE AREA
WEDNESDAY AND MAY PICK UP ENOUGH MOISTURE FOR A 20 PERCENT CHANCE
ON WEDNESDAY. THIS WEAK FRONT IS EXPECTED TO HAVE DISSIPATED BY
THURSDAY BUT MORE CLOUDS AND A BETTER CHANCE OF PRECIPITATION
SHOULD FAVOR THE SLIGHTLY COOLER ECMWF TEMPERATURES OVER GFS.
SO...DECIDED TO GO WITH HIGHS IN THE MIDDLE 80S FOR WEDNESDAY
AND THURSDAY. OTHERWISE...OVERNIGHT LOWS FROM THE LOWER 60S
IN THE NORTH TO MIDDLE 60S IN THE SOUTH FOR TUESDAY NIGHT AND
WEDNESDAY NIGHT.
&&
.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
REGIONAL RADARS INDICATE ADDITIONAL THUNDERSTORM ACTIVITY ALONG
THE CENTRAL APPALACHIANS...BUT THIS ACTIVITY IS NOT EXPECTED TO
HOLD TOGETHER INTO OUR CWA TONIGHT DUE TO LIMITED MOISTURE AND
GENERAL NORTHWEST FLOW PATTERN. SO EXPECTING VFR CONDITIONS DURING
THE TAF PERIOD. SOME OF THE MOS GUIDANCE SHOWS THE POSSIBILITY OF
UPPER END MVFR FOG DURING THE EARLY MORNING HOURS...BUT CONFIDENCE
IN FORMATION IS NOT HIGH DUE TO DEVELOPMENT OF A LOW-LEVEL JET AND
LOW-LEVEL MIXING OVERNIGHT. SO AS STATED ABOVE...VFR FORECAST. THE
MAIN FRONT WILL BE PASSING THROUGH THE FORECAST AREA DURING THE
MORNING ON FRIDAY...BUT IT SHOULD MOVE THROUGH TAF SITES
DRY...WITH ONLY A WIND SHIFT TO THE NORTHWEST TO SHOW ITS PASSAGE.
SCATTERED CU EXPECTED THROUGH THE DAY...GENERALLY AROUND 4.5KFT.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED AT
THIS TIME.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
308 PM CDT THU SEP 12 2013
.DISCUSSION...
303 AM CDT
A NOTICEABLE COOL DOWN WILL BE THE FOCUS OF THE SHORT TERM FORECAST
ALONG WITH ASSOCIATED LAKE EFFECT SHOWERS. WATER VAPOR IMAGERY SHOWS
AN AMPLIFYING LARGE SCALE TROUGH OVER HUDSON BAY/ONTARIO SPREADING
INTO THE GREAT LAKES. AN EMBEDDED WAVE THAT HAS BEEN HELPING THE
AMPLIFICATION IS ROTATING ACROSS LAKE SUPERIOR. FURTHER WEST...A REX
PATTERN HAS SET UP WITH AN UPPER RIDGE EXTENDING NORTHWARD ACROSS
BRITISH COLUMBIA WITH A CUTOFF UPPER LOW SPINNING OVER
NEVADA/ARIZONA/UTAH. ANOTHER UPPER TROUGH IS OUT OVER THE EASTERN
PACIFIC. AT THE SURFACE...LOW PRESSURE IS MOVING INTO NORTHERN
QUEBEC WITH A WEAKER LOW OVER NORTHERN NEW YORK. A LARGE AREA OF
HIGH PRESSURE IS MOVING SOUTHWARD INTO THE NORTHERN HIGH PLAINS. ONE
COLD FRONT IS SOUTH OF THE AREA...WITH A SECOND APPROACHING THE
IL/WI BORDER...AND A THIRD MOVING INTO CENTRAL MINNESOTA AND
NORTHERN WISCONSIN.
TODAY THROUGH FRIDAY...COOLER AIR WILL BEGIN WORKING INTO THE AREA
TODAY AS A TROUGH AXIS EXTENDING FROM THE UPPER WAVE CROSSING LAKE
SUPERIOR SWINGS ACROSS THE AREA. THE SECOND SFC COOL FRONT WILL BE
PUSHED ACROSS THE AREA AS THIS OCCURS THROUGH THE MORNING. THE PUSH
OF COLDER AIR HASTENS BY EARLY AFTERNOON WITH H85 TEMPS FALLING TO
BETWEEN +10 AND +13C BY MID/LATE AFTERNOON. ANOTHER UPPER WAVE NOW
OVER MANITOBA AND NOT AS OBVIOUS ON WATER VAPOR...WILL CROSS THE
AREA EARLY THIS EVENING BRINGING A STRONGER PUSH OF COLDER AIR
BEHIND THE THIRD COLD FRONT NOTED ABOVE. AS FAR AS POPS...CURRENT
ACTIVITY ACROSS THE FAR SOUTHERN CWA WILL BE SAGGING TO THE SOUTH
OVER THE NEXT FEW HOURS. THE SECOND FRONT AND NEXT UPPER TROUGH LOOK
TO COME THROUGH DRY...BUT THE SUBSEQUENT UPPER WAVE THIS EVENING MAY
BRING SOME SCATTERED SHOWERS WITH IT BUT THESE LOOK TO BE FOCUSED TO
THE NORTH AND EAST OF THE AREA. WILL INCLUDE SOME SLIGHT POPS ACROSS
NORTHEAST ILLINOIS HOWEVER. HIGH PRESSURE WILL BE BUILDING INTO THE
UPPER MISSISSIPPI RIVER VALLEY AND WESTERN GREAT LAKES THIS EVENING
WHICH WILL SET UP A TIGHTENING PRESSURE GRADIENT ACROSS LAKE
MICHIGAN ALLOWING NORTH TO NORTH-NORTHEAST WINDS TO PICK UP. AS THE
COLDER AIR SPREADS IN LAKE TO H85 DELTA T/S WILL QUICKLY INCREASE TO
AROUND 20C AS H85 TEMPS FALL TO AROUND 2C BY FRIDAY MORNING. THE
INCREASING DELTA T WILL COMBINE WITH INVERSION HEIGHTS OF APPROX
10-12 KFT FROM TONIGHT THROUGH FRIDAY MORNING TO GENERATE LAKE
CLOUDS AND LAKE EFFECT SHOWERS ONCE THE UPPER WAVE EXITS LATER THIS
EVENING. LOW LEVEL FLOW TRAJECTORY AIMS THE ACTIVITY ACROSS THE
SOUTHERN COOK COUNTY SHORELINE AND NORTHWEST INDIANA AS IT DEVELOPS
LATE TONIGHT. FROM THAT POINT ON THE EVOLUTION BECOMES MORE
DIFFICULT AS THE STRONG FLOW DOWN THE LAKE AND STRONG INSTABILITY
MAY ALLOW FOR A SHARP CONVERGENCE BAND TO SET UP WHICH MAY AIM THE
BAND A LITTLE FURTHER WEST INTO COOK COUNTY FRIDAY MORNING...WITH
ACTIVITY POSSIBLY MAKING IT INTO WILL AND KANKAKEE COUNTIES GIVEN
THE FAIRLY STRONG LOW LEVEL FLOW. AT THIS POINT WILL FOCUS MID
CHANCE POPS ACROSS AND JUST WEST OF THE IN/IL STATE LINE ACROSS
COOK/WILL AND LAKE INDIANA FRIDAY MORNING. AM A BIT CONCERNED THAT
THESE MAY BE TOO LOW THOUGH. INVERSION HEIGHTS SLOWLY LOWER DURING
THE DAY FRIDAY WHICH SHOULD REDUCE THE COVERAGE OF SHOWERS SO WILL
TAPER POPS ACCORDINGLY. THE UPPER RIDGE OVER B.C./ALBERTA WILL MOVE
EASTWARD AS A TROUGH PUSHES INTO IT FROM THE NORTHWEST. THIS WILL
PUSH WARMER AIR INTO THE AREA EARLY SATURDAY WHICH WILL COINCIDE
WITH THE HIGH MOVING OVER THE LOCAL AREA SHUTTING OFF ANY KIND OF
LAKE FETCH. HIGH TEMPS TODAY WILL RANGE FROM THE MID 70S TO LOWER
80S...WITH LOWER 70S LIKELY NEAR LAKE MICHIGAN. FRIDAY WILL BE MUCH
COOLER WITH HIGHS ONLY IN THE MID TO UPPER 60S.
SATURDAY AND BEYOND...HIGH PRESSURE WILL BE OVER THE AREA SATURDAY
WITH A WEAK SOUTHERLY FLOW SETTING UP AS IT SHIFTS TO THE EAST. THE
UPPER RIDGE WILL BE OFF TO THE EAST AND WILL HAVE PROVIDED SOME MID
LEVEL WARMING TO AROUND +10/12 AT H85 BY LATE IN THE DAY. HIGHS WILL
LIKELY BE SEVERAL DEGREES WARMER THAN FRIDAY THOUGH MAXIMUM WARMING
LOOKS TO BE TEMPERED BY WEAK MIXING. SOME WEAK UPPER RIDGING WILL
REMAIN TO THE SOUTHWEST OF THE AREA AS THE UPPER TROUGH APPROACHES
WHICH WILL TRY TO DEVELOP A MID LEVEL BAROCLINIC ZONE FROM THE
CENTRAL PLAINS TO THE MID MISSISSIPPI RIVER VALLEY SATURDAY NIGHT.
THIS MAY RESULT IN SOME SHRA/TSRA DEVELOPMENT BY SUNDAY MORNING
WHICH WOULD THEN BE PUSHED SOUTHWARD AS THE UPPER TROUGH PUSHES IN
SOME TIME SUNDAY. THE ATTENDANT SFC LOW WILL BE WELL TO THE NORTH
AND EAST BUT A COOL FRONT WILL BE PUSHED ACROSS THE AREA LATER
SUNDAY. HIGH PRESSURE WILL THEN MOVE ACROSS THE UPPER GREAT LAKES
PROVIDING A DRY NORTHERLY FLOW BACK OVER THE AREA MONDAY BUT ANOTHER
UPPER RIDGE WILL TRACK EASTWARD BRINGING WARM ADVECTION AND POSSIBLY
SOME PRECIP TO THE AREA TUESDAY. DO NOT HAVE A GREAT DEAL OF
CONFIDENCE IN DETAILS AS THE UPPER FLOW PATTERN FORECAST FOR NEXT
WEEK BY MEDIUM RANGE GUIDANCE HAS FLUCTUATED A FEW TIMES IN THE PAST
FEW NIGHTS BUT THERE HAS BEEN A CONSISTENT SIGNAL FOR TEMPS TO BE
WARMING THROUGH MID WEEK.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
WINDS RAPIDLY BECOMING NORTH-NORTHEAST AFTER 20 UTC AT ORD AND
AROUND 21 UTC AT KMDW.
POTENTIAL FOR MVFR LAKE EFFECT STRATOCUMULUS TONIGHT.
SLIGHT CHANCE OF LAKE EFFECT SHOWERS FROM LATE THIS AFTERNOON AND
EVENING.
KJB
//DISCUSSION...UPDATED 18Z...
A SECONDARY PUSH OF COLDER AIR IS CURRENTLY DROPPING SOUTHWARD
ACROSS WISCONSIN AND NORTHERN LAKE MICHIGAN EARLY THIS AFTERNOON.
THIS AIR MASS WILL PUSH ACROSS NORTHERN ILLINOIS LATER THIS AFTERNOON
AND THIS EVENING AHEAD OF AN APPROACHING SURFACE HIGH. THIS WILL
RESULT IN A RAPID WIND SHIFT AND INCREASE OUT OF THE NORTH-NORTHEAST
BY MID AFTERNOON. IN ADDITION...THE COLDER AIR MASS ALSO LOOKS TO SET
THE STAGE FOR SOME MVFR STRATOCU CIGS...LIKELY AROUND OR SHORTLY
AFTER SUNSET ACROSS THE EASTERN TAF SITES. THESE CIGS MAY HANG
AROUND FOR MUCH OF THE NIGHT FOR KMDW AND KGYY...AND POSSIBLY KORD
AS CLOUDS CONTINUE TO GENERATE OVER THE LAKE AND MOVE INLAND.
THERE IS ALSO A SLIGHT CHANCE OF A FEW LAKE INDUCED SHOWERS LATER
THIS AFTERNOON/EARLY THIS EVENING. HOWEVER...DUE TO THE LOW
CHANCES...I HAVE LEFT THE TAFS DRY AT THIS TIME.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
HIGH CONFIDENCE IN WIND SHIFT WITHIN THE NEXT HOUR OR TWO.
MODERATE CONFIDENCE IN A PERIOD OF MVFR CIGS TONIGHT.
LOW CONFIDENCE IN ANY -SHRA IMPACTING THE TERMINALS.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRI NIGHT...POSSIBILITY OF MVFR LAKE EFFECT CEILINGS...ESPECIALLY
KMDW.
SAT...VFR. WX NIL.
SUN...VFR. CHANCE SHOWERS AND THUNDERSTORMS.
MON AND TUE...VFR. WX NIL.
WED...VFR. CHANCE SHOWERS AND THUNDERSTORMS.
TRS
&&
.MARINE...
303 PM CDT
GUSTY NORTH-NORTHEAST WINDS WILL AFFECT LAKE MICHIGAN TONIGHT AND
FRIDAY...AS A COLD FRONT CLEARS THE SOUTH END OF THE LAKE BY EARLY
THIS EVENING AND AN AREA OF HIGH PRESSURE BUILDS SOUTHEAST FROM
THE NORTHERN PLAINS ACROSS THE WESTERN LAKES FRIDAY INTO FRIDAY
NIGHT. SUSTAINED WINDS 20-25 KT WITH A FEW GUSTS AROUND 30 KT ARE
POSSIBLE ESPECIALLY THIS EVENING BEHIND THE FRONT. THE LONG NORTH
FETCH AND MODERATELY STRONG WINDS WILL PRODUCE WAVES UP TO 10 FT
ACROSS THE SOUTH 2/3 OF THE LAKE...WITH WINDS AND WAVES GRADUALLY
DIMINISHING LATER FRIDAY NIGHT.
THE SURFACE HIGH WILL SLIDE ACROSS THE LAKE FRIDAY NIGHT INTO
SATURDAY WITH SOUTH-SOUTHWEST WINDS DEVELOPING SATURDAY...AND
INCREASING AGAIN PARTICULARLY ON THE NORTH END OF THE LAKE
SATURDAY NIGHT AS A DEEP AREA OF LOW PRESSURE PASSES ACROSS
HUDSON BAY. THIS LOW WILL TRAIL ANOTHER COLD FRONT SOUTHWARD
ACROSS THE LAKE ON SUNDAY...SHIFTING WINDS BACK TO THE NORTH WITH
GUSTS 20-25 KT AGAIN SUNDAY EVENING. ANOTHER AREA OF HIGH PRESSURE
WILL THEN BUILD ACROSS THE AREA MONDAY.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...7 PM THURSDAY TO 5 AM
SATURDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...7 PM THURSDAY TO 5 AM
SATURDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 5 AM SATURDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
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Area Forecast Discussion
National Weather Service Lincoln IL
300 PM CDT Thu Sep 12 2013
.DISCUSSION...
ISSUED 300 PM CDT Thu Sep 12 2013
Main concerns this package include cooler temperatures and pcpn
chances Sunday and then again toward middle of next week.
Models look in fairly good agreement with the overall upper level pattern
in the short term but then begins to differ in the extended period
at middle of next week. On the surface, the models look similar
with a cooler air mass dropping into the region for the weekend
and again for beginning of next week. So a blend of the models
looks to be in order for most of the period.
SHORT TERM...Tonight through Sunday
The cold front is finally pushing through the area this afternoon
and this will being much drier and cooler weather into the area
for tomorrow and into the weekend. So dry conditions are expected
tonight though Saturday night. As the high pressure slides to the
east a frontal system will push toward the area and bring the
chances of showers and thunderstorms to the northwest parts of the
cwa for Sunday.
Cooler temps are also expected with this high pressure with the
coldest temps being Friday and Friday night. Temp also expected to
be below normal through the period.
LONG TERM...Sunday night through Thursday
This front will quickly move through Sunday, but not very strong,
so no pcpn expected Sunday night. Then another cool high pressure
area will move across the Great Lakes region the first part of the
week. Another front will approach the area behind this high
pressure but models seem to keep the front and pcpn west of the
area for the first part of the week. Then as the high pressure
pushes east, pcpn will begin to move into the area for Tuesday
night and Wednesday. GFS seems aggressive with pcpn coming into the
area so will just have chc pops in the northwest and west through
Wednesday. Then the chc pops will gradually shift east some for
Wednesday night and Thursday.
Temps will gradually warm through the period as the high prss
moves east of the area and allows southerly winds to return with
increased warm air advection.
Geelhart/Auten
&&
.AVIATION...
ISSUED 1209 PM CDT Thu Sep 12 2013
Threat of showers is now south of the TAF sites as a secondary
cold front has moved into central Illinois at midday. Remaining
mid clouds will largely exit the TAF sites through 20Z. However,
the NAM and RAP models hint at some stratocumulus advecting down
from near Lake Michigan early this evening. Gusty winds to near 20
knots are expected for a few hours this afternoon as skies
initially clear, then diminish by about 23Z. VFR conditions will
continue into Friday as strong high pressure builds south from
near Lake Superior.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1222 PM CDT THU SEP 12 2013
.DISCUSSION...
303 AM CDT
A NOTICEABLE COOL DOWN WILL BE THE FOCUS OF THE SHORT TERM FORECAST
ALONG WITH ASSOCIATED LAKE EFFECT SHOWERS. WATER VAPOR IMAGERY SHOWS
AN AMPLIFYING LARGE SCALE TROUGH OVER HUDSON BAY/ONTARIO SPREADING
INTO THE GREAT LAKES. AN EMBEDDED WAVE THAT HAS BEEN HELPING THE
AMPLIFICATION IS ROTATING ACROSS LAKE SUPERIOR. FURTHER WEST...A REX
PATTERN HAS SET UP WITH AN UPPER RIDGE EXTENDING NORTHWARD ACROSS
BRITISH COLUMBIA WITH A CUTOFF UPPER LOW SPINNING OVER
NEVADA/ARIZONA/UTAH. ANOTHER UPPER TROUGH IS OUT OVER THE EASTERN
PACIFIC. AT THE SURFACE...LOW PRESSURE IS MOVING INTO NORTHERN
QUEBEC WITH A WEAKER LOW OVER NORTHERN NEW YORK. A LARGE AREA OF
HIGH PRESSURE IS MOVING SOUTHWARD INTO THE NORTHERN HIGH PLAINS. ONE
COLD FRONT IS SOUTH OF THE AREA...WITH A SECOND APPROACHING THE
IL/WI BORDER...AND A THIRD MOVING INTO CENTRAL MINNESOTA AND
NORTHERN WISCONSIN.
TODAY THROUGH FRIDAY...COOLER AIR WILL BEGIN WORKING INTO THE AREA
TODAY AS A TROUGH AXIS EXTENDING FROM THE UPPER WAVE CROSSING LAKE
SUPERIOR SWINGS ACROSS THE AREA. THE SECOND SFC COOL FRONT WILL BE
PUSHED ACROSS THE AREA AS THIS OCCURS THROUGH THE MORNING. THE PUSH
OF COLDER AIR HASTENS BY EARLY AFTERNOON WITH H85 TEMPS FALLING TO
BETWEEN +10 AND +13C BY MID/LATE AFTERNOON. ANOTHER UPPER WAVE NOW
OVER MANITOBA AND NOT AS OBVIOUS ON WATER VAPOR...WILL CROSS THE
AREA EARLY THIS EVENING BRINGING A STRONGER PUSH OF COLDER AIR
BEHIND THE THIRD COLD FRONT NOTED ABOVE. AS FAR AS POPS...CURRENT
ACTIVITY ACROSS THE FAR SOUTHERN CWA WILL BE SAGGING TO THE SOUTH
OVER THE NEXT FEW HOURS. THE SECOND FRONT AND NEXT UPPER TROUGH LOOK
TO COME THROUGH DRY...BUT THE SUBSEQUENT UPPER WAVE THIS EVENING MAY
BRING SOME SCATTERED SHOWERS WITH IT BUT THESE LOOK TO BE FOCUSED TO
THE NORTH AND EAST OF THE AREA. WILL INCLUDE SOME SLIGHT POPS ACROSS
NORTHEAST ILLINOIS HOWEVER. HIGH PRESSURE WILL BE BUILDING INTO THE
UPPER MISSISSIPPI RIVER VALLEY AND WESTERN GREAT LAKES THIS EVENING
WHICH WILL SET UP A TIGHTENING PRESSURE GRADIENT ACROSS LAKE
MICHIGAN ALLOWING NORTH TO NORTH-NORTHEAST WINDS TO PICK UP. AS THE
COLDER AIR SPREADS IN LAKE TO H85 DELTA T/S WILL QUICKLY INCREASE TO
AROUND 20C AS H85 TEMPS FALL TO AROUND 2C BY FRIDAY MORNING. THE
INCREASING DELTA T WILL COMBINE WITH INVERSION HEIGHTS OF APPROX
10-12 KFT FROM TONIGHT THROUGH FRIDAY MORNING TO GENERATE LAKE
CLOUDS AND LAKE EFFECT SHOWERS ONCE THE UPPER WAVE EXITS LATER THIS
EVENING. LOW LEVEL FLOW TRAJECTORY AIMS THE ACTIVITY ACROSS THE
SOUTHERN COOK COUNTY SHORELINE AND NORTHWEST INDIANA AS IT DEVELOPS
LATE TONIGHT. FROM THAT POINT ON THE EVOLUTION BECOMES MORE
DIFFICULT AS THE STRONG FLOW DOWN THE LAKE AND STRONG INSTABILITY
MAY ALLOW FOR A SHARP CONVERGENCE BAND TO SET UP WHICH MAY AIM THE
BAND A LITTLE FURTHER WEST INTO COOK COUNTY FRIDAY MORNING...WITH
ACTIVITY POSSIBLY MAKING IT INTO WILL AND KANKAKEE COUNTIES GIVEN
THE FAIRLY STRONG LOW LEVEL FLOW. AT THIS POINT WILL FOCUS MID
CHANCE POPS ACROSS AND JUST WEST OF THE IN/IL STATE LINE ACROSS
COOK/WILL AND LAKE INDIANA FRIDAY MORNING. AM A BIT CONCERNED THAT
THESE MAY BE TOO LOW THOUGH. INVERSION HEIGHTS SLOWLY LOWER DURING
THE DAY FRIDAY WHICH SHOULD REDUCE THE COVERAGE OF SHOWERS SO WILL
TAPER POPS ACCORDINGLY. THE UPPER RIDGE OVER B.C./ALBERTA WILL MOVE
EASTWARD AS A TROUGH PUSHES INTO IT FROM THE NORTHWEST. THIS WILL
PUSH WARMER AIR INTO THE AREA EARLY SATURDAY WHICH WILL COINCIDE
WITH THE HIGH MOVING OVER THE LOCAL AREA SHUTTING OFF ANY KIND OF
LAKE FETCH. HIGH TEMPS TODAY WILL RANGE FROM THE MID 70S TO LOWER
80S...WITH LOWER 70S LIKELY NEAR LAKE MICHIGAN. FRIDAY WILL BE MUCH
COOLER WITH HIGHS ONLY IN THE MID TO UPPER 60S.
SATURDAY AND BEYOND...HIGH PRESSURE WILL BE OVER THE AREA SATURDAY
WITH A WEAK SOUTHERLY FLOW SETTING UP AS IT SHIFTS TO THE EAST. THE
UPPER RIDGE WILL BE OFF TO THE EAST AND WILL HAVE PROVIDED SOME MID
LEVEL WARMING TO AROUND +10/12 AT H85 BY LATE IN THE DAY. HIGHS WILL
LIKELY BE SEVERAL DEGREES WARMER THAN FRIDAY THOUGH MAXIMUM WARMING
LOOKS TO BE TEMPERED BY WEAK MIXING. SOME WEAK UPPER RIDGING WILL
REMAIN TO THE SOUTHWEST OF THE AREA AS THE UPPER TROUGH APPROACHES
WHICH WILL TRY TO DEVELOP A MID LEVEL BAROCLINIC ZONE FROM THE
CENTRAL PLAINS TO THE MID MISSISSIPPI RIVER VALLEY SATURDAY NIGHT.
THIS MAY RESULT IN SOME SHRA/TSRA DEVELOPMENT BY SUNDAY MORNING
WHICH WOULD THEN BE PUSHED SOUTHWARD AS THE UPPER TROUGH PUSHES IN
SOME TIME SUNDAY. THE ATTENDANT SFC LOW WILL BE WELL TO THE NORTH
AND EAST BUT A COOL FRONT WILL BE PUSHED ACROSS THE AREA LATER
SUNDAY. HIGH PRESSURE WILL THEN MOVE ACROSS THE UPPER GREAT LAKES
PROVIDING A DRY NORTHERLY FLOW BACK OVER THE AREA MONDAY BUT ANOTHER
UPPER RIDGE WILL TRACK EASTWARD BRINGING WARM ADVECTION AND POSSIBLY
SOME PRECIP TO THE AREA TUESDAY. DO NOT HAVE A GREAT DEAL OF
CONFIDENCE IN DETAILS AS THE UPPER FLOW PATTERN FORECAST FOR NEXT
WEEK BY MEDIUM RANGE GUIDANCE HAS FLUCTUATED A FEW TIMES IN THE PAST
FEW NIGHTS BUT THERE HAS BEEN A CONSISTENT SIGNAL FOR TEMPS TO BE
WARMING THROUGH MID WEEK.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
TRENDS IN WIND DIRECTION...SPEED...GUSTINESS THROUGH THE
PERIOD...WITH WINDS BECOMING NORTH-NORTHEASTERLY BY MID AFTERNOON.
POTENTIAL FOR MVFR LAKE EFFECT STRATOCUMULUS TONIGHT.
SLIGHT CHANCE OF LAKE EFFECT SHOWERS FROM LATE THIS AFTERNOON AND
EVENING.
KJB
//DISCUSSION...UPDATED 18Z...
A SECONDARY PUSH OF COLDER AIR IS CURRENTLY DROPPING SOUTHWARD
ACROSS WISCONSIN AND NORTHERN LAKE MICHIGAN EARLY THIS AFTERNOON.
THIS AIR MASS WILL PUSH ACROSS NORTHERN ILLINOIS LATER THIS AFTERNOON
AND THIS EVENING AHEAD OF AN APPROACHING SURFACE HIGH. THIS WILL
RESULT IN A RAPID WIND SHIFT AND INCREASE OUT OF THE NORTH-NORTHEAST
BY MID AFTERNOON. IN ADDITION...THE COLDER AIR MASS ALSO LOOKS TO SET
THE STAGE FOR SOME MVFR STRATOCU CIGS...LIKELY AROUND OR SHORTLY
AFTER SUNSET ACROSS THE EASTERN TAF SITES. THESE CIGS MAY HANG
AROUND FOR MUCH OF THE NIGHT FOR KMDW AND KGYY...AND POSSIBLY KORD
AS CLOUDS CONTINUE TO GENERATE OVER THE LAKE AND MOVE INLAND.
THERE IS ALSO A SLIGHT CHANCE OF A FEW LAKE INDUCED SHOWERS LATER
THIS AFTERNOON/EARLY THIS EVENING. HOWEVER...DUE TO THE LOW
CHANCES...I HAVE LEFT THE TAFS DRY AT THIS TIME.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
MODERATE CONFIDENCE IN WIND SHIFT TIMING AND SPEEDS.
MODERATE CONFIDENCE IN A PERIOD OF MVFR CIGS TONIGHT.
LOW CONFIDENCE IN ANY -SHRA IMPACTING THE TERMINALS.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRI NIGHT...POSSIBILITY OF MVFR LAKE EFFECT CEILINGS...ESPECIALLY
KMDW.
SAT...VFR. WX NIL.
SUN...VFR. CHANCE SHOWERS AND THUNDERSTORMS.
MON AND TUE...VFR. WX NIL.
WED...VFR. CHANCE SHOWERS AND THUNDERSTORMS.
TRS
&&
.MARINE...
430 AM CDT
A COLD FRONT WILL CONTINUE TO DROP DOWN THE SOUTH END OF LAKE
MICHIGAN TODAY AS LOW PRESSURE EAST OF JAMES BAY EARLY THIS
MORNING DEEPENS AND MOVES EAST TO THE LOWER ST. LAWRENCE VALLEY
BY TONIGHT. HIGH PRESSURE CENTERED IN FAR SOUTHEASTERN
SASKATCHEWAN EARLY THIS MORNING WILL BE BUILDING SOUTHEASTWARD TO
ONTARIO...THE LAKE SUPERIOR AND THE UPPER MIDWEST BY FRIDAY
MORNING.
AN INCREASING PRESSURE GRADIENT OVER LAKE MICHIGAN ALONG WITH
MUCH STRONGER COLD AIR ADVECTION TODAY WILL LEAD TO STRONG NORTH
BREEZES DEVELOPING BY LATER IN THE AFTERNOON. THE STRONG NORTH
BREEZE WILL PREVAIL THROUGH TONIGHT AND INTO EARLY FRIDAY
MORNING. SOME NEAR GALE TO GALE FORCE GUSTS ARE LIKELY TO OCCUR
THIS EVENING THROUGH EARLY FRIDAY MORNING...THE PERIOD OF
STRONGEST WINDS.
WINDS WILL THEN START TO DIMINISH FRIDAY AS THE CENTER OF THE
HIGH SETTLES FURTHER SOUTHEASTWARD ACROSS THE UPPER GREAT LAKES
AND MID MISSISSIPPI VALLEY BY FRIDAY EVENING.
WITH THE PROLONGED PERIOD OF STRONG NORTH WINDS AND THE HIGH
WAVES THEY WILL GENERATE...THE SMALL CRAFT ORIGINALLY ISSUED
WEDNESDAY AFTERNOON WILL BE ALLOWED TO CONTINUE THROUGH FRIDAY
NIGHT AS THIS IS WHEN WAVES WILL HAVE FINALLY SUBSIDED TO BELOW
SMALL CRAFT ADVISORY CRITERIA.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...7 PM THURSDAY TO 5 AM
SATURDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...7 PM THURSDAY TO 5 AM
SATURDAY.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 5 AM SATURDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
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Area Forecast Discussion
National Weather Service Lincoln IL
1209 PM CDT Thu Sep 12 2013
.DISCUSSION...
ISSUED 1007 AM CDT Thu Sep 12 2013
Initial wind shift has pushed through the CWA, with a secondary
boundary accompanying drier air roughly along a Quincy to Chicago
line. Scattered showers have diminished northwest of I-55 and will
be continuing over the southeast half of the CWA through midday.
Clearing line is accompanying the second boundary, but latest RAP
model showing some potential for cold-air stratocumulus advecting
in from the northeast late this afternoon.
Have sent some updated zones/grids to reflect the latest timing of
the rain and cloud trends. The showers have kept the temperatures
a bit cooler across the south half of the forecast area, so will
need to keep an eye on any needed adjustment to the highs.
Geelhart
&&
.AVIATION...
ISSUED 1209 PM CDT Thu Sep 12 2013
Threat of showers is now south of the TAF sites as a secondary
cold front has moved into central Illinois at midday. Remaining
mid clouds will largely exit the TAF sites through 20Z. However,
the NAM and RAP models hint at some stratocumulus advecting down
from near Lake Michigan early this evening. Gusty winds to near 20
knots are expected for a few hours this afternoon as skies
initially clear, then diminish by about 23Z. VFR conditions will
continue into Friday as strong high pressure builds south from
near Lake Superior.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 301 AM CDT Thu Sep 12 2013
SHORT TERM...Today through Saturday
Initial frontal boundary has slipped south to near I-70 early this
morning, but this boundary is in the process of washing out as a
stronger front with cool/dry air push drops into central WI.
Scattered convection has shown a recent increase from northern MO
into central IL north of I-72 along the 925/850 mb frontal zone
where SPC mesoanalysis indicates moisture pooling and weak
frontogenesis. A shortwave now digging into the upper Midwest and
upper jet as close as northern IL also aiding in recent uptick.
Narrow ribbon of precipitable water up to 1.8" will lead to
isolated areas of heavier rain next several hours as the elevated
front progresses south through the CWA. Have chance pops for the
southern half of CWA this morning, and feel by midday most of the
activity will be shifting south of the area and have a dry
forecast this afternoon. Weak cold advection will be occurring for
bulk of the day, until the stronger front to our north moves
through 21z-03z. Highs will be cooler than recent days but still
several degrees above normal in the mid 80s. Stronger low/mid
level cold advection commences tonight behind the secondary
boundary and lows should dip into the low/mid 50s.
Strong cold advection continues Friday on brisk N/NE flow which
brings H85 temps down to 5-6 C by late day. Very dry air mass will
support mostly sunny skies but this will do little to offset CAA and
sided on cooler side of guidance for upper 60s/lower 70s highs.
Some sites will see highs around 30F cooler than just 3 days
prior. This would be the coolest day since the record cool wx
back in late July. Canadian high pressure ridge responsible for
the cool down will settle south towards southern Lake Michigan by
Saturday morning. Clear skies and light boundary layer winds under
5 kts near the ridge axis will produce excellent radiational
cooling, and widespread mid 40s lows are expected. Favored cool
spots will likely see low 40s which is only a few degrees above
upper 30s record lows for the date.
LONG TERM...Sunday through Wednesday
An upper trof lifting out of the cutoff low currently over the
desert SW, will shift into the Plains this weekend and bring an
associated front towards the area on Sunday. This system will
encounter confluent mid level flow between the eastern U.S. trof
and ridge to the south which is not favorable for widespread or
heavy rain. Lingering easterly flow and dry air off departing
ridge will also limit precip potential and kept pops to low chance
mention on Sunday. Beyond this system another Canadian high builds
into the Great Lakes early next week. This will keep temperatures
seasonable to slightly below normal. A persistent weakness in the
upper flow looks to bring active weather to the Plains and parts
of the Midwest through mid-week, but feel with the ridge nearby to
our east much of this will be confined to the west through Tuesday.
Thus have limited pops to slight chance over the west until a more
significant wave moves in around Wed.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
503 PM CDT WED SEP 11 2013
.DISCUSSION...
249 PM CDT
SYNOPSIS...A COUPLE OF COLD FRONTS PASS THROUGH THE REGION BRINGING
SCATTERED SHOWERS AND MUCH COOLER AIR TO THE REGION.
TODAY AND TONIGHT...
A COLD FRONT IS OVER NORTHERN IL AND STRETCHES INTO CENTRAL MI.
SHOWERS AND A FEW STORMS ARE FIRING ALONG THE FRONT...WITH THE
STRONGER STORMS ASSOCIATED WITH VARIOUS BOUNDARIES OVER NORTHERN
IL. THE TWO MAIN BOUNDARIES APPEAR TO BE THE LAKE BREEZE OVER
NORTHERN COOK COUNTY AND AN OUTFLOW BOUNDARY FROM THE NORTHERN
SHOWERS THAT STRETCHES FROM PAW PAW TO ELMHURST. EXPECTING MUCH OF
THE SAME THIS AFTERNOON WITH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS. THE STRONGER STORMS WILL BE ASSOCIATED WITH BETTER
AREAS OF FORCING. LATEST RAP ANALYSIS INDICATE CAPE VALUES UP TO
2000 J/KG OVER THE REGION. THE BEST 0-6 KM SHEAR IS NORTH OF I-88
WHERE SHOWERS HAVE STABILIZED THE ENVIRONMENT. AREAS SOUTH OF I-88
AND THE COLD FRONT REMAIN RELATIVELY CLEAR WITH LOW LEVEL LAPSE
RATES AT OR ABOVE 9C/KM BUT UPPER LEVEL LAPSE RATES REMAIN WEAK
AROUND 6C/KM. SHEAR IS ALSO LESS THAN DESIRABLE SO EXPECTING
SHOWERS AND STORMS TO DEVELOP AS THE FRONT SINKS SOUTH...BUT NOT
ANTICIPATING ANY WELL ORGANIZED STORMS. MAIN THREAT REMAINS
ISOLATED DAMAGING WINDS OR A DOWNBURST GIVEN PWAT VALUES 1.5+ WHICH
IS +2SD ABOVE NORMAL FOR SEPTEMBER. SOUNDINGS ALSO FEATURE INVERTED
VS BELOW 700MB. WIDESPREAD SEVERE WEATHER IS NOT LIKELY GIVEN THE
MARGINAL CONDITIONS AND WEAK FORCING.
EXPECTING THE FRONT AND ASSOCIATED PRECIP TO MOVE SOUTH OF I-88 LATE
THIS AFTERNOON INTO THIS EVENING AND CONTINUE TO THE SOUTH
OVERNIGHT. EXPECTING SKIES TO THIN OVERNIGHT AND TEMPS TO DROP TO
AROUND 60 NORTH OF I-88 AND THEN INTO THE MID TO UPPER 60S ALONG AND
SOUTH OF I-80...AND DOWNTOWN.
THURSDAY THROUGH FRIDAY...
THE TROUGH AXIS OF THE UPPER LEVEL TROUGH PASSES OVER THE REGION
TOMORROW ALONG WITH A SECONDARY COLD FRONT. NOT EXPECTING ANY
PRECIP WITH THE SECONDARY FRONT...BUT TEMPS WILL FALL. GUIDANCE
SUGGESTS 850MB TEMPS WILL BE -2 TO 6 DEGREES C BY FRIDAY MORNING.
GIVEN THAT LAKE WATER TEMPS ARE AROUND 21 DEGREES C LAKE EFFECT RAIN
BECOMES A CONCERN THURSDAY NIGHT THROUGH FRIDAY. WINDS TURN OUT OF
THE NORTHEAST AHEAD OF THE BUILDING HIGH PRESSURE...WHICH CREATE AN
ELONGATED FETCH DOWN THE LAKE. AS SUCH HAVE A SLIGHT CHANCE TO
CHANCE OF LIGHT SHOWERS OVER LAKE AND COOK COUNTIES IN IL THURSDAY
NIGHT. WINDS SHIFT TO THE NORTH FRIDAY...THEREFORE SHIFTED THE
CHANCE OF SHOWERS OVER WESTERN COOK COUNTY AND NORTHERN IN FRIDAY.
THE SHOWERS SHOULD DISSIPATE FRIDAY AFTERNOON AS TEMPS WARM ALOFT
DUE TO THE BUILDING HIGH PRESSURE.
TEMPS LATE THIS WEEK WILL BE MUCH MORE FALL LIKE...AND BELOW
NORMAL. THURSDAYS HIGHS WILL BE IN THE MID 70S TO MID 80S...AND
FRIDAYS HIGHS WILL BE IN THE MID TO UPPER 60S. OVERNIGHT LOWS WILL
BE IN THE 50S THURSDAY AND 40S ON FRIDAY.
EXTENDED...SATURDAY THROUGH TUESDAY...
THE UPPER LEVEL RIDGE REMAINS OVER TEXAS WHILE THE NOW MOBILE UPPER
LEVEL LOW WEAKENS AND DISSIPATES SATURDAY NIGHT. A SHORTWAVE TROUGH
PASSES OVER SOUTHERN WI/NORTHERN IL SATURDAY NIGHT THEN THE TROUGH
AXIS OF A LOW OVER HUDSON BAY ROTATES OVER THE REGION SUNDAY.
RIDGING FOLLOWS BEHIND THE TROUGH INTO MID NEXT WEEK.
AT THE SURFACE THE EXTENDED BEGINS WITH HIGH PRESSURE DEPARTING TO
THE SOUTHEAST. A WEAK SURFACE TROUGH PASSES OVER THE REGION SUNDAY
BRINGING A CHANCE OF RAIN AND THUNDERSTORMS. HIGH PRESSURE MOVES IN
BEHIND THE TROUGH MONDAY WITH A RETURN TO DRY CONDITIONS. THE HIGH
SHIFTS EAST AND A SHORTWAVE TROUGH MAY BRING ANOTHER ROUND OF
SHOWERS AND STORMS TUESDAY NIGHT INTO WEDNESDAY. OVERALL NOT SEEING
A GOOD CHANCE FOR THE SOAKING RAIN WE NEED.
BELOW NORMAL TEMPS ARE EXPECTED OVER THE WEEKEND WITH HIGH TEMPS IN
THE LOW 70S AND OVERNIGHT LOWS IN THE 50S. A WARM UP TO MORE
SEASONAL TEMPS IS EXPECTED TUESDAY INTO WEDNESDAY.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* WIND DIRECTION THROUGH THIS EVENING. CMS
//DISCUSSION...UPDATED 22Z...
WINDS ARE RETURNING TO A WEST/NORTHWEST DIRECTION AFTER VARIOUS
BOUNDARIES/WIND SHIFTS ALONG WITH A FEW TSRA MOVED THROUGH THE
AREA. CONFIDENCE REGARDING SOME FORM OF WESTERLY WINDS IS MEDIUM
INTO THIS EVENING...BUT THE ACTUAL DIRECTIONS COULD BE QUITE
VARIABLE AT TIMES. WIND SPEEDS SHOULD REMAIN UNDER 10 KTS. ANY
ADDITIONAL SHRA/TSRA WILL REMAIN SOUTH AND EAST OF ORD/MDW. CMS
PREVIOUS 18Z DISCUSSION...
MAIN FORECAST CONCERNS THIS AFTERNOON REVOLVE AROUND THE DETAILS OF
A COLD FRONT THAT IS CURRENTLY VERY DIFFUSE AND UNORGANIZED...
STRETCHING ROUGHLY FROM NEAR MKE SOUTHWEST TO MLI. LIGHT RETURNS
ARE SHOWING UP ON RADAR INDICATING A FEW SHOWERS ALONG THE
FRONT...AND SATELLITE IMAGERY INDICATES THAT THERE IS SOME VERTICAL
GROWTH...BUT THICK MID LEVEL CLOUD CANOPY ADVECTING OVER THE AREA
WILL ONLY INHIBIT FURTHER DESTABILIZATION THIS AFTERNOON...WHICH
ALREADY WAS A CONCERN LEADING UP TO THIS POINT. IN ADDITION TO THE
MEAGER INSTABILITY...FORCING IS VERY WEAK...MAINLY ASSOCIATED WITH
THE VERY MODEST CONVERGENCE ALONG THE FRONT ITSELF. LITTLE IF ANY
UPPER LEVEL SUPPORT IS NOTED THIS AFTERNOON. SEVERAL HI-RES
MODELS SEEM TO FALL IN TWO CAMPS...SHOWING THE CURRENT ACTIVITY TO
OUR WEST INCREASING IN INTENSITY AND COVERAGE OVER THE NEXT COUPLE
HOURS...OR THE CURRENT ACTIVITY TO OUR WEST STAYING AS IS OR
FADING. GIVEN THE AFOREMENTIONED LACK OF FORCING...LEANING TOWARDS
THE FRONT MORE OR LESS REMAINING QUIET AS IT IS NOW AS IT MOVES
OVER THE TERMINALS. IF THE FRONT WERE TO LIGHT UP LATER TODAY...IT
MAY BE SOUTH OF THE TERMINALS AS THE FRONT MOVES INTO MORE
UNSTABLE AIRMASS. WITH THAT IN MIND...REMOVED THUNDER MENTION FROM
THE TERMINALS...EXCEPT FOR GYY WHICH SEEM TO HAVE THE BEST CHANCE
FOR POSSIBLY SEEING SOMETHING MID TO LATE AFTERNOON. OVERALL
CONFIDENCE IN THE EVOLUTION THE NEXT FEW HOURS IS PRETTY LOW AND
WILL HAVE TO MONITOR RADAR TRENDS CLOSELY FOR FURTHER ADJUSTMENTS.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM FOR WIND DIRECTIONS/SPEEDS INTO THIS EVENING. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT AND FRIDAY...LAKE EFFECT STRATOCU CLOUDS MAY REACH
FAR ENOUGH INLAND TO PRODUCE MVFR CEILINGS.
SATURDAY...VFR. WX NIL.
SUNDAY...PREVAILING VFR. CHANCE OF SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS.
MONDAY AND TUESDAY..VFR. WX NIL.
TRS
&&
.MARINE...
142 PM CDT
A STRONGER COLD FRONT IS EXPECTED TO PUSH DOWN THE LAKE TONIGHT AS
LOW PRESSURE TRACKS FROM ONTARIO INTO QUEBEC. THE WINDS BEHIND THIS
FRONT WILL BECOME NORTHERLY UP TO 25 KT INTO THURSDAY. THESE
NORTHERLY WINDS MAY INCREASE A BIT MORE CLOSER TO 30KT FOR A PERIOD
LATER THURSDAY AND INTO THURSDAY NIGHT AS A MUCH COOLER AIRMASS
DROPS ACROSS THE LAKE AHEAD OF A CANADIAN HIGH PRESSURE SYSTEM. THE
WINDS WILL LIKELY REMAIN ELEVATED OUT OF THE NORTH INTO FRIDAY
BEFORE THE SURFACE HIGH CENTERS ITSELF OVER THE LAKE BY FRIDAY
EVENING...LEADING TO A PERIOD OF LIGHT AND VARIABLE WINDS. FOLLOWING
THE PASSAGE OF THIS HIGH...THE WINDS SHOULD BECOME SOUTHERLY AGAIN
FOR SATURDAY...BEFORE YET ANOTHER COLD FRONT LIKELY DROPS SOUTH
ACROSS THE LAKE LATER IN THE WEEKEND SETTING UP ANOTHER PERIOD OF
STRONGER NORTHERLY FLOW.
THESE STRONG NORTHERLY WINDS WILL LEAD TO SOME HIGH WAVES OF 6 TO 10
FT ACROSS FAR SOUTHERN LAKE MICHIGAN THURSDAY NIGHT INTO
FRIDAY...INCLUDING THE NEAR SHORE WATERS. THEREFORE A SMALL CRAFT
ADVISORY WILL BE NEEDED FOR THE ILLINOIS AND INDIANA NEAR SHORES
FROM THURSDAY AFTERNOON THROUGH FRIDAY NIGHT.
THERE IS ALSO A SMALL THREAT FOR SOME WATER SPOUTS LATE THURSDAY AND
INTO FRIDAY. HOWEVER...IT APPEARS TO BE A SMALL WINDOW AS UPPER
LEVEL TEMPERATURES WILL BEGIN TO WARM QUICKLY EARLY
FRIDAY...LIMITING THE OVERALL DEPTH OF THE INSTABILITY. IN SPITE OF
THIS...WE WILL MAINTAIN THE CHANCES FOR SOME ISOLATED WATER SPOUTS.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...1 PM THURSDAY TO 5 AM
SATURDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...1 PM THURSDAY TO 5 AM
SATURDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...1 PM THURSDAY TO 5 AM SATURDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
301 PM CDT WED SEP 11 2013
.DISCUSSION...
249 PM CDT
SYNOPSIS...A COUPLE OF COLD FRONTS PASS THROUGH THE REGION BRINGING
SCATTERED SHOWERS AND MUCH COOLER AIR TO THE REGION.
TODAY AND TONIGHT...
A COLD FRONT IS OVER NORTHERN IL AND STRETCHES INTO CENTRAL MI.
SHOWERS AND A FEW STORMS ARE FIRING ALONG THE FRONT...WITH THE
STRONGER STORMS ASSOCIATED WITH VARIOUS BOUNDARIES OVER NORTHERN
IL. THE TWO MAIN BOUNDARIES APPEAR TO BE THE LAKE BREEZE OVER
NORTHERN COOK COUNTY AND AN OUTFLOW BOUNDARY FROM THE NORTHERN
SHOWERS THAT STRETCHES FROM PAW PAW TO ELMHURST. EXPECTING MUCH OF
THE SAME THIS AFTERNOON WITH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS. THE STRONGER STORMS WILL BE ASSOCIATED WITH BETTER
AREAS OF FORCING. LATEST RAP ANALYSIS INDICATE CAPE VALUES UP TO
2000 J/KG OVER THE REGION. THE BEST 0-6 KM SHEAR IS NORTH OF I-88
WHERE SHOWERS HAVE STABILIZED THE ENVIRONMENT. AREAS SOUTH OF I-88
AND THE COLD FRONT REMAIN RELATIVELY CLEAR WITH LOW LEVEL LAPSE
RATES AT OR ABOVE 9C/KM BUT UPPER LEVEL LAPSE RATES REMAIN WEAK
AROUND 6C/KM. SHEAR IS ALSO LESS THAN DESIRABLE SO EXPECTING
SHOWERS AND STORMS TO DEVELOP AS THE FRONT SINKS SOUTH...BUT NOT
ANTICIPATING ANY WELL ORGANIZED STORMS. MAIN THREAT REMAINS
ISOLATED DAMAGING WINDS OR A DOWNBURST GIVEN PWAT VALUES 1.5+ WHICH
IS +2SD ABOVE NORMAL FOR SEPTEMBER. SOUNDINGS ALSO FEATURE INVERTED
VS BELOW 700MB. WIDESPREAD SEVERE WEATHER IS NOT LIKELY GIVEN THE
MARGINAL CONDITIONS AND WEAK FORCING.
EXPECTING THE FRONT AND ASSOCIATED PRECIP TO MOVE SOUTH OF I-88 LATE
THIS AFTERNOON INTO THIS EVENING AND CONTINUE TO THE SOUTH
OVERNIGHT. EXPECTING SKIES TO THIN OVERNIGHT AND TEMPS TO DROP TO
AROUND 60 NORTH OF I-88 AND THEN INTO THE MID TO UPPER 60S ALONG AND
SOUTH OF I-80...AND DOWNTOWN.
THURSDAY THROUGH FRIDAY...
THE TROUGH AXIS OF THE UPPER LEVEL TROUGH PASSES OVER THE REGION
TOMORROW ALONG WITH A SECONDARY COLD FRONT. NOT EXPECTING ANY
PRECIP WITH THE SECONDARY FRONT...BUT TEMPS WILL FALL. GUIDANCE
SUGGESTS 850MB TEMPS WILL BE -2 TO 6 DEGREES C BY FRIDAY MORNING.
GIVEN THAT LAKE WATER TEMPS ARE AROUND 21 DEGREES C LAKE EFFECT RAIN
BECOMES A CONCERN THURSDAY NIGHT THROUGH FRIDAY. WINDS TURN OUT OF
THE NORTHEAST AHEAD OF THE BUILDING HIGH PRESSURE...WHICH CREATE AN
ELONGATED FETCH DOWN THE LAKE. AS SUCH HAVE A SLIGHT CHANCE TO
CHANCE OF LIGHT SHOWERS OVER LAKE AND COOK COUNTIES IN IL THURSDAY
NIGHT. WINDS SHIFT TO THE NORTH FRIDAY...THEREFORE SHIFTED THE
CHANCE OF SHOWERS OVER WESTERN COOK COUNTY AND NORTHERN IN FRIDAY.
THE SHOWERS SHOULD DISSIPATE FRIDAY AFTERNOON AS TEMPS WARM ALOFT
DUE TO THE BUILDING HIGH PRESSURE.
TEMPS LATE THIS WEEK WILL BE MUCH MORE FALL LIKE...AND BELOW
NORMAL. THURSDAYS HIGHS WILL BE IN THE MID 70S TO MID 80S...AND
FRIDAYS HIGHS WILL BE IN THE MID TO UPPER 60S. OVERNIGHT LOWS WILL
BE IN THE 50S THURSDAY AND 40S ON FRIDAY.
EXTENDED...SATURDAY THROUGH TUESDAY...
THE UPPER LEVEL RIDGE REMAINS OVER TEXAS WHILE THE NOW MOBILE UPPER
LEVEL LOW WEAKENS AND DISSIPATES SATURDAY NIGHT. A SHORTWAVE TROUGH
PASSES OVER SOUTHERN WI/NORTHERN IL SATURDAY NIGHT THEN THE TROUGH
AXIS OF A LOW OVER HUDSON BAY ROTATES OVER THE REGION SUNDAY.
RIDGING FOLLOWS BEHIND THE TROUGH INTO MID NEXT WEEK.
AT THE SURFACE THE EXTENDED BEGINS WITH HIGH PRESSURE DEPARTING TO
THE SOUTHEAST. A WEAK SURFACE TROUGH PASSES OVER THE REGION SUNDAY
BRINGING A CHANCE OF RAIN AND THUNDERSTORMS. HIGH PRESSURE MOVES IN
BEHIND THE TROUGH MONDAY WITH A RETURN TO DRY CONDITIONS. THE HIGH
SHIFTS EAST AND A SHORTWAVE TROUGH MAY BRING ANOTHER ROUND OF
SHOWERS AND STORMS TUESDAY NIGHT INTO WEDNESDAY. OVERALL NOT SEEING
A GOOD CHANCE FOR THE SOAKING RAIN WE NEED.
BELOW NORMAL TEMPS ARE EXPECTED OVER THE WEEKEND WITH HIGH TEMPS IN
THE LOW 70S AND OVERNIGHT LOWS IN THE 50S. A WARM UP TO MORE
SEASONAL TEMPS IS EXPECTED TUESDAY INTO WEDNESDAY.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* CONVECTIVE CHANCES AS A COLD FRONT SAGS ACROSS THE REGION THIS
AFTERNOON. APPEARS BEST CHANCE FOR THUNDERSTORMS WILL BE ALONG
AND SOUTH OF A LINE FROM ARR TO MDW...BUT CANNOT COMPLETELY RULE
OUT SOMETHING FARTHER NORTH.
* WIND TRENDS THIS AFTERNOON...MULTIPLE OUTFLOW BOUNDARIES IN THE
AREA HAVE LED TO VERY MESSY WIND FIELD. WINDS SHOULD GENERALLY
BE LESS THAN 10 KT OUTSIDE THE INFLUENCE OF CONVECTIVE OUTFLOW.
BMD
//DISCUSSION...UPDATED 18Z...
MAIN FORECAST CONCERNS THIS AFTERNOON REVOLVE AROUND THE DETAILS OF
A COLD FRONT THAT IS CURRENTLY VERY DIFFUSE AND UNORGANIZED...
STRETCHING ROUGHLY FROM NEAR MKE SOUTHWEST TO MLI. LIGHT RETURNS
ARE SHOWING UP ON RADAR INDICATING A FEW SHOWERS ALONG THE
FRONT...AND SATELLITE IMAGERY INDICATES THAT THERE IS SOME VERTICAL
GROWTH...BUT THICK MID LEVEL CLOUD CANOPY ADVECTING OVER THE AREA
WILL ONLY INHIBIT FURTHER DESTABILIZATION THIS AFTERNOON...WHICH
ALREADY WAS A CONCERN LEADING UP TO THIS POINT. IN ADDITION TO THE
MEAGER INSTABILITY...FORCING IS VERY WEAK...MAINLY ASSOCIATED WITH
THE VERY MODEST CONVERGENCE ALONG THE FRONT ITSELF. LITTLE IF ANY
UPPER LEVEL SUPPORT IS NOTED THIS AFTERNOON. SEVERAL HI-RES
MODELS SEEM TO FALL IN TWO CAMPS...SHOWING THE CURRENT ACTIVITY TO
OUR WEST INCREASING IN INTENSITY AND COVERAGE OVER THE NEXT COUPLE
HOURS...OR THE CURRENT ACTIVITY TO OUR WEST STAYING AS IS OR
FADING. GIVEN THE AFOREMENTIONED LACK OF FORCING...LEANING TOWARDS
THE FRONT MORE OR LESS REMAINING QUIET AS IT IS NOW AS IT MOVES
OVER THE TERMINALS. IF THE FRONT WERE TO LIGHT UP LATER TODAY...IT
MAY BE SOUTH OF THE TERMINALS AS THE FRONT MOVES INTO MORE
UNSTABLE AIRMASS. WITH THAT IN MIND...REMOVED THUNDER MENTION FROM
THE TERMINALS...EXCEPT FOR GYY WHICH SEEM TO HAVE THE BEST CHANCE
FOR POSSIBLY SEEING SOMETHING MID TO LATE AFTERNOON. OVERALL
CONFIDENCE IN THE EVOLUTION THE NEXT FEW HOURS IS PRETTY LOW AND
WILL HAVE TO MONITOR RADAR TRENDS CLOSELY FOR FURTHER ADJUSTMENTS.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN CONVECTIVE TRENDS ALONG THE FRONT THROUGH
THIS AFTERNOON...MEDIUM CONFIDENCE THAT TSRA WILL STAY SOUTH OF
ORD.
* HIGH CONFIDENCE IN VFR CONDITIONS OUTSIDE THE INFLUENCE OF
SHRA/TSRA.
* LOW CONFIDENCE IN WIND DIRECTION THIS AFTERNOON. MEDIUM
CONFIDENCE IN WINDS STAYING LESS THAN 10 KT OUTSIDE THE
INFLUENCE OF AN OUTFLOW BOUNDARY.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT AND FRIDAY...LAKE EFFECT STRATOCU CLOUDS MAY REACH
FAR ENOUGH INLAND TO PRODUCE MVFR CEILINGS.
SATURDAY...VFR. WX NIL.
SUNDAY...PREVAILING VFR. CHANCE OF SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS.
MONDAY AND TUESDAY..VFR. WX NIL.
TRS
&&
.MARINE...
142 PM CDT
A STRONGER COLD FRONT IS EXPECTED TO PUSH DOWN THE LAKE TONIGHT AS
LOW PRESSURE TRACKS FROM ONTARIO INTO QUEBEC. THE WINDS BEHIND THIS
FRONT WILL BECOME NORTHERLY UP TO 25 KT INTO THURSDAY. THESE
NORTHERLY WINDS MAY INCREASE A BIT MORE CLOSER TO 30KT FOR A PERIOD
LATER THURSDAY AND INTO THURSDAY NIGHT AS A MUCH COOLER AIRMASS
DROPS ACROSS THE LAKE AHEAD OF A CANADIAN HIGH PRESSURE SYSTEM. THE
WINDS WILL LIKELY REMAIN ELEVATED OUT OF THE NORTH INTO FRIDAY
BEFORE THE SURFACE HIGH CENTERS ITSELF OVER THE LAKE BY FRIDAY
EVENING...LEADING TO A PERIOD OF LIGHT AND VARIABLE WINDS. FOLLOWING
THE PASSAGE OF THIS HIGH...THE WINDS SHOULD BECOME SOUTHERLY AGAIN
FOR SATURDAY...BEFORE YET ANOTHER COLD FRONT LIKELY DROPS SOUTH
ACROSS THE LAKE LATER IN THE WEEKEND SETTING UP ANOTHER PERIOD OF
STRONGER NORTHERLY FLOW.
THESE STRONG NORTHERLY WINDS WILL LEAD TO SOME HIGH WAVES OF 6 TO 10
FT ACROSS FAR SOUTHERN LAKE MICHIGAN THURSDAY NIGHT INTO
FRIDAY...INCLUDING THE NEAR SHORE WATERS. THEREFORE A SMALL CRAFT
ADVISORY WILL BE NEEDED FOR THE ILLINOIS AND INDIANA NEAR SHORES
FROM THURSDAY AFTERNOON THROUGH FRIDAY NIGHT.
THERE IS ALSO A SMALL THREAT FOR SOME WATER SPOUTS LATE THURSDAY AND
INTO FRIDAY. HOWEVER...IT APPEARS TO BE A SMALL WINDOW AS UPPER
LEVEL TEMPERATURES WILL BEGIN TO WARM QUICKLY EARLY
FRIDAY...LIMITING THE OVERALL DEPTH OF THE INSTABILITY. IN SPITE OF
THIS...WE WILL MAINTAIN THE CHANCES FOR SOME ISOLATED WATER SPOUTS.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...1 PM THURSDAY TO 5 AM
SATURDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...1 PM THURSDAY TO 5 AM
SATURDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...1 PM THURSDAY TO 5 AM SATURDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
253 PM CDT WED SEP 11 2013
.DISCUSSION...
249 PM CDT
SYNOPSIS...A COUPLE OF COLD FRONTS PASS THROUGH THE REGION BRINGING
SCATTERED SHOWERS AND MUCH COOLER AIR TO THE REGION.
TODAY AND TONIGHT...
A COLD FRONT IS OVER NORTHERN IL AND STRETCHES INTO CENTRAL MI.
SHOWERS AND A FEW STORMS ARE FIRING ALONG THE FRONT...WITH THE
STRONGER STORMS ASSOCIATED WITH VARIOUS BOUNDARIES OVER NORTHERN
IL. THE TWO MAIN BOUNDARIES APPEAR TO BE THE LAKE BREEZE OVER
NORTHERN COOK COUNTY AND AN OUTFLOW BOUNDARY FROM THE NORTHERN
SHOWERS THAT STRETCHES FROM PAW PAW TO ELMHURST. EXPECTING MUCH OF
THE SAME THIS AFTERNOON WITH SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS. THE STRONGER STORMS WILL BE ASSOCIATED WITH BETTER
AREAS OF FORCING. LATEST RAP ANALYSIS INDICATE CAPE VALUES UP TO
2000 J/KG OVER THE REGION. THE BEST 0-6 KM SHEAR IS NORTH OF I-88
WHERE SHOWERS HAVE STABILIZED THE ENVIRONMENT. AREAS SOUTH OF I-88
AND THE COLD FRONT REMAIN RELATIVELY CLEAR WITH LOW LEVEL LAPSE
RATES AT OR ABOVE 9C/KM BUT UPPER LEVEL LAPSE RATES REMAIN WEAK
AROUND 6C/KM. SHEAR IS ALSO LESS THAN DESIRABLE SO EXPECTING
SHOWERS AND STORMS TO DEVELOP AS THE FRONT SINKS SOUTH...BUT NOT
ANTICIPATING ANY WELL ORGANIZED STORMS. MAIN THREAT REMAINS
ISOLATED DAMAGING WINDS OR A DOWNBURST GIVEN PWAT VALUES 1.5+ WHICH
IS +2SD ABOVE NORMAL FOR SEPTEMBER. SOUNDINGS ALSO FEATURE INVERTED
VS BELOW 700MB. WIDESPREAD SEVERE WEATHER IS NOT LIKELY GIVEN THE
MARGINAL CONDITIONS AND WEAK FORCING.
EXPECTING THE FRONT AND ASSOCIATED PRECIP TO MOVE SOUTH OF I-88 LATE
THIS AFTERNOON INTO THIS EVENING AND CONTINUE TO THE SOUTH
OVERNIGHT. EXPECTING SKIES TO THIN OVERNIGHT AND TEMPS TO DROP TO
AROUND 60 NORTH OF I-88 AND THEN INTO THE MID TO UPPER 60S ALONG AND
SOUTH OF I-80...AND DOWNTOWN.
THURSDAY THROUGH FRIDAY...
THE TROUGH AXIS OF THE UPPER LEVEL TROUGH PASSES OVER THE REGION
TOMORROW ALONG WITH A SECONDARY COLD FRONT. NOT EXPECTING ANY
PRECIP WITH THE SECONDARY FRONT...BUT TEMPS WILL FALL. GUIDANCE
SUGGESTS 850MB TEMPS WILL BE -2 TO 6 DEGREES C BY FRIDAY MORNING.
GIVEN THAT LAKE WATER TEMPS ARE AROUND 21 DEGREES C LAKE EFFECT RAIN
BECOMES A CONCERN THURSDAY NIGHT THROUGH FRIDAY. WINDS TURN OUT OF
THE NORTHEAST AHEAD OF THE BUILDING HIGH PRESSURE...WHICH CREATE AN
ELONGATED FETCH DOWN THE LAKE. AS SUCH HAVE A SLIGHT CHANCE TO
CHANCE OF LIGHT SHOWERS OVER LAKE AND COOK COUNTIES IN IL THURSDAY
NIGHT. WINDS SHIFT TO THE NORTH FRIDAY...THEREFORE SHIFTED THE
CHANCE OF SHOWERS OVER WESTERN COOK COUNTY AND NORTHERN IN FRIDAY.
THE SHOWERS SHOULD DISSIPATE FRIDAY AFTERNOON AS TEMPS WARM ALOFT
DUE TO THE BUILDING HIGH PRESSURE.
TEMPS LATE THIS WEEK WILL BE MUCH MORE FALL LIKE...AND BELOW
NORMAL. THURSDAYS HIGHS WILL BE IN THE MID 70S TO MID 80S...AND
FRIDAYS HIGHS WILL BE IN THE MID TO UPPER 60S. OVERNIGHT LOWS WILL
BE IN THE 50S THURSDAY AND 40S ON FRIDAY.
EXTENDED...SATURDAY THROUGH TUESDAY...
THE UPPER LEVEL RIDGE REMAINS OVER TEXAS WHILE THE NOW MOBILE UPPER
LEVEL LOW WEAKENS AND DISSIPATES SATURDAY NIGHT. A SHORTWAVE TROUGH
PASSES OVER SOUTHERN WI/NORTHERN IL SATURDAY NIGHT THEN THE TROUGH
AXIS OF A LOW OVER HUDSON BAY ROTATES OVER THE REGION SUNDAY.
RIDGING FOLLOWS BEHIND THE TROUGH INTO MID NEXT WEEK.
AT THE SURFACE THE EXTENDED BEGINS WITH HIGH PRESSURE DEPARTING TO
THE SOUTHEAST. A WEAK SURFACE TROUGH PASSES OVER THE REGION SUNDAY
BRINGING A CHANCE OF RAIN AND THUNDERSTORMS. HIGH PRESSURE MOVES IN
BEHIND THE TROUGH MONDAY WITH A RETURN TO DRY CONDITIONS. THE HIGH
SHIFTS EAST AND A SHORTWAVE TROUGH MAY BRING ANOTHER ROUND OF
SHOWERS AND STORMS TUESDAY NIGHT INTO WEDNESDAY. OVERALL NOT SEEING
A GOOD CHANCE FOR THE SOAKING RAIN WE NEED.
BELOW NORMAL TEMPS ARE EXPECTED OVER THE WEEKEND WITH HIGH TEMPS IN
THE LOW 70S AND OVERNIGHT LOWS IN THE 50S. A WARM UP TO MORE
SEASONAL TEMPS IS EXPECTED TUESDAY INTO WEDNESDAY.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* CONVECTIVE CHANCES AS A COLD FRONT SAGS ACROSS THE REGION THIS
AFTERNOON.
BMD
//DISCUSSION...UPDATED 18Z...
MAIN FORECAST CONCERNS THIS AFTERNOON REVOLVE AROUND THE DETAILS OF
A COLD FRONT THAT IS CURRENTLY VERY DIFFUSE AND UNORGANIZED...
STRETCHING ROUGHLY FROM NEAR MKE SOUTHWEST TO MLI. LIGHT RETURNS
ARE SHOWING UP ON RADAR INDICATING A FEW SHOWERS ALONG THE
FRONT...AND SATELLITE IMAGERY INDICATES THAT THERE IS SOME VERTICAL
GROWTH...BUT THICK MID LEVEL CLOUD CANOPY ADVECTING OVER THE AREA
WILL ONLY INHIBIT FURTHER DESTABILIZATION THIS AFTERNOON...WHICH
ALREADY WAS A CONCERN LEADING UP TO THIS POINT. IN ADDITION TO THE
MEAGER INSTABILITY...FORCING IS VERY WEAK...MAINLY ASSOCIATED WITH
THE VERY MODEST CONVERGENCE ALONG THE FRONT ITSELF. LITTLE IF ANY
UPPER LEVEL SUPPORT IS NOTED THIS AFTERNOON. SEVERAL HI-RES
MODELS SEEM TO FALL IN TWO CAMPS...SHOWING THE CURRENT ACTIVITY TO
OUR WEST INCREASING IN INTENSITY AND COVERAGE OVER THE NEXT COUPLE
HOURS...OR THE CURRENT ACTIVITY TO OUR WEST STAYING AS IS OR
FADING. GIVEN THE AFOREMENTIONED LACK OF FORCING...LEANING TOWARDS
THE FRONT MORE OR LESS REMAINING QUIET AS IT IS NOW AS IT MOVES
OVER THE TERMINALS. IF THE FRONT WERE TO LIGHT UP LATER TODAY...IT
MAY BE SOUTH OF THE TERMINALS AS THE FRONT MOVES INTO MORE
UNSTABLE AIRMASS. WITH THAT IN MIND...REMOVED THUNDER MENTION FROM
THE TERMINALS...EXCEPT FOR GYY WHICH SEEM TO HAVE THE BEST CHANCE
FOR POSSIBLY SEEING SOMETHING MID TO LATE AFTERNOON. OVERALL
CONFIDENCE IN THE EVOLUTION THE NEXT FEW HOURS IS PRETTY LOW AND
WILL HAVE TO MONITOR RADAR TRENDS CLOSELY FOR FURTHER ADJUSTMENTS.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* LOW CONFIDENCE IN CONVECTIVE TRENDS ALONG THE FRONT THROUGH THIS
AFTERNOON.
* HIGH CONFIDENCE IN VFR CONDITIONS OUTSIDE THE INFLUENCE OF
SHRA/TSRA.
BMD
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT AND FRIDAY...LAKE EFFECT STRATOCU CLOUDS MAY REACH
FAR ENOUGH INLAND TO PRODUCE MVFR CEILINGS.
SATURDAY...VFR. WX NIL.
SUNDAY...PREVAILING VFR. CHANCE OF SHOWERS AND A SLIGHT CHANCE OF
THUNDERSTORMS.
MONDAY AND TUESDAY..VFR. WX NIL.
TRS
&&
.MARINE...
142 PM CDT
A STRONGER COLD FRONT IS EXPECTED TO PUSH DOWN THE LAKE TONIGHT AS
LOW PRESSURE TRACKS FROM ONTARIO INTO QUEBEC. THE WINDS BEHIND THIS
FRONT WILL BECOME NORTHERLY UP TO 25 KT INTO THURSDAY. THESE
NORTHERLY WINDS MAY INCREASE A BIT MORE CLOSER TO 30KT FOR A PERIOD
LATER THURSDAY AND INTO THURSDAY NIGHT AS A MUCH COOLER AIRMASS
DROPS ACROSS THE LAKE AHEAD OF A CANADIAN HIGH PRESSURE SYSTEM. THE
WINDS WILL LIKELY REMAIN ELEVATED OUT OF THE NORTH INTO FRIDAY
BEFORE THE SURFACE HIGH CENTERS ITSELF OVER THE LAKE BY FRIDAY
EVENING...LEADING TO A PERIOD OF LIGHT AND VARIABLE WINDS. FOLLOWING
THE PASSAGE OF THIS HIGH...THE WINDS SHOULD BECOME SOUTHERLY AGAIN
FOR SATURDAY...BEFORE YET ANOTHER COLD FRONT LIKELY DROPS SOUTH
ACROSS THE LAKE LATER IN THE WEEKEND SETTING UP ANOTHER PERIOD OF
STRONGER NORTHERLY FLOW.
THESE STRONG NORTHERLY WINDS WILL LEAD TO SOME HIGH WAVES OF 6 TO 10
FT ACROSS FAR SOUTHERN LAKE MICHIGAN THURSDAY NIGHT INTO
FRIDAY...INCLUDING THE NEAR SHORE WATERS. THEREFORE A SMALL CRAFT
ADVISORY WILL BE NEEDED FOR THE ILLINOIS AND INDIANA NEAR SHORES
FROM THURSDAY AFTERNOON THROUGH FRIDAY NIGHT.
THERE IS ALSO A SMALL THREAT FOR SOME WATER SPOUTS LATE THURSDAY AND
INTO FRIDAY. HOWEVER...IT APPEARS TO BE A SMALL WINDOW AS UPPER
LEVEL TEMPERATURES WILL BEGIN TO WARM QUICKLY EARLY
FRIDAY...LIMITING THE OVERALL DEPTH OF THE INSTABILITY. IN SPITE OF
THIS...WE WILL MAINTAIN THE CHANCES FOR SOME ISOLATED WATER SPOUTS.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...1 PM THURSDAY TO 5 AM
SATURDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...1 PM THURSDAY TO 5 AM
SATURDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...1 PM THURSDAY TO 5 AM SATURDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
337 PM EDT WED SEP 11 2013
.SYNOPSIS...
ISSUED AT 1150 AM EDT TUE SEP 10 2013
A COLD FRONT WILL SAG SLOWLY SOUTHWARD THROUGH THE SOUTHERN GREAT
LAKES LATER TODAY. SOUTH OF THE FRONT TEMPERATURES WILL CLIMB INTO
THE LOWER TO POSSIBLY MIDDLE 90S...WITH 70S AND 80S BEHIND THE
FRONT. SOME SHOWERS AND THUNDERSTORMS MAY DEVELOP THIS AFTERNOON
AND EVENING...WITH A CHANCE OF SHOWERS AND THUNDERSTORMS
CONTINUING INTO TONIGHT. BEHIND THE FRONT...SIGNIFICANTLY COOLER
AIR WILL SPREAD THROUGH THE REGION. HIGHS ON THURSDAY WILL BE ON
THE ORDER OF 15 TO 20 DEGREES COOLER THAN TODAY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 332 PM EDT WED SEP 11 2013
FOCUS OF FORECAST ON NEXT 6 TO 9 HOURS WITH CONVECTION CHANCES
ALONG/AHEAD OF COLD FRONT.
TEMPS HAVE MANAGED TO CLIMB TO AOA 90 MOST EVERYWHERE EXCEPT NEAR
THE IMMEDIATE LAKE SHORE AND FAR NE AREAS (WHICH COULD STILL MAKE IT
AT 20Z). ONSHORE WIND HAS NOW SETTLED INTO KBEH WITH A 10 DEGREE
DROP IN TEMPS AFTER A PEAK OF 89 A FEW HOURS AGO. AS MANY OF THE
HIGH RES MODELS INDICATED...LL MSTR HAS BEEN MIXED OUT WITH MOST
LOCATIONS IN THE 60 TO 63 DEGREE RANGE FOR DEWPTS. THE EXCEPTION WAS
ALONG A OUTFLOW BOUNDARY THAT HAS NOW STALLED OUT FROM WOLCOTT IN TO
COLUMBIA CITY TO MONROE MI. AN ISOLATED SHOWER OR 2 MANAGED TO POP
ACROSS MAINLY NW OHIO...BUT DIED JUST AS QUICK. 18Z DTX SOUNDING
SHOWED ANY CAPPING HAS BEEN ERODED. HOWEVER...LACK OF FORCING NW OF
THIS BOUNDARY LOOKS TO PRECLUDE ANY DEVELOPMENT UNTIL ARRIVAL OF
COLD FRONT. COLD FRONT WAS LOCATED ROUGHLY FROM QUAD CITIES IOWA TO
THE THUMB OF MICHIGAN. CLUSTER OF SHOWERS AND ISOL THUNDER WAS
MOVING ACROSS THE LAKE AND SHOWING SIGNS OF TRYING TO EXPAND
SWARD. WILL HAVE A SLGT CHC POPS IN FAR NW AREAS AND BLEND INTO
LATER THIS AFTERNOON/EVE TO REFLECT POTENTIAL FOR AT LEAST WIDELY
SCT CONVECTION AS COLD FRONT EDGES SOUTH. SVR RISK LOOKING
MINIMAL WITH MAIN FOCUS WELL SE OF THE AREA (16Z DAY 1 OUTLOOK
REMOVED MOST OF THE AREA FROM SLGT RISK) BUT STILL WORTHY OF
WATCHING OVER THE NEXT COUPLE OF HOURS. HRRR HAS SUGGESTED OVER
THE PAST FEW RUNS OF CONVECTION DEVELOPING BACK ACROSS
ILLINOIS/IOWA COULD MOVE IN LATER THIS EVENING/OVERNIGHT. POPS
LATER TONIGHT MAY NEED TO BE EXPANDED SOMEWHAT NW WARD...BUT AGAIN
CONFIDENCE IN ANY ONE SOLUTION TO LOW.
AS NOTED IN PAST DISCUSSION...AIR BEHIND THIS FRONT WILL BE COOLER
THAN PAST SEVERAL DAYS BUT PRETTY SEASONABLE FOR MID SEPT WITH HIGHS
IN THE MID TO UPR 70S. STRONGER TROUGH AND PUSH OF MUCH COLDER AIR
WILL ARRIVE THURSDAY AFTERNOON. THIS FRONT IS DYNAMICALLY MORE
IMPRESSIVE BUT SERIOUSLY LACKING MSTR (MORE SO THAN TODAY). A FEW OF
THE MODELS SHOW A FEW SHOWERS COULD IMPACT FAR NE AREAS LATE THURS
AM INTO THE AFTERNOON UNTIL FROPA BUT WILL LEAVE FORECAST DRY FOR
NOW.
&&
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 332 PM EDT WED SEP 11 2013
SIG SW TROUGH OVR SRN SK WILL CONT TO AMPLIFY SEWD THROUGH THE ST
LAW VALLEY SHRT TERM W/RAPIDLY FOLLOWING SECONDARY DISTURBANCE QUICK
ON ITS HEELS LT THU ALL CARVING OUT A RESPECTABLY DEEP TROUGH OVR
NEW ENGLAND THIS WEEKEND. STG SFC ANTICYCLONE BLDG SWD INTO THE OH
VALLEY AS THIS EVOLVES WILL BRING ABT THE COLDEST AIR OF THE SEASON
SO FAR AND IN STARK CONTRAST TO HEAT OF LAST TWO DAYS. PER MOS
TRENDS AND IN LIGHT OF TEMPS ACRS CNTRL CANADA SEE SOME VALIDITY TO
MET MOS IMPLIED MID-UPR 30 MINS SAT AM UNDERNEATH CRUX OF SFC RIDGE.
REGARDLESS BREVITY OF DEEP CAA SURGE SHRT LIVED W/PROGRESSIVE FLW
ALOFT CONTG...ALTHOUGH SEASONABLY COOL TEMPS SHLD EXTEND THROUGH SAT
BFR TEMPERED MODERATION ENSUES TIED TO THE BEGINNINGS OF LARGER
SCALE PATTN SHIFT ACRS NOAM NOTED IN MOST MED RANGE GUIDANCE AT LONG
RANGE...DYS 6-10 AND OF WHICH LOOKS TO RESULT IN A MUCH WETTER/WARMER 8-14
DY PD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 140 PM EDT WED SEP 11 2013
CONFIDENCE IN CONVECTION THROUGH THE FIRST HALF OF THE PERIOD WANING
AS OUTFLOW BOUNDARY CONTINUED TO WORK ACROSS THE AREA. AT 1730Z THIS
FEATURE WAS LOCATED FROM PONTIAC MI SE TO BETWEEN WARSAW AND
COLUMBIA CITY TO MONTICELLO. WHILE ACCAS FIELD HAS BEEN TRYING TO
ESTABLISH ITSELF ALONG THIS FEATURE...STRONG MIXING HAS DECIMATED
EARLIER CLOUD COVER WITH NEW DEVELOPMENT NOW BEING NOTED ALONG AND
EST OF THE BOUNDARY AS CONVECTIVE TEMPS APPEARS NEARLY MET. BEHIND
THIS FEATURE CHANCES FOR CONVECTION WILL LIKELY HINGE ON COLD
FRONT DROPPING IN THIS EVENING. A STRAY SHOWER/STORMS CAN`T BE
RULED OUT THIS AFTERNOON AT KFWA AS THE OUTFLOW BOUNDARY PASSES
THROUGH AND INTERACTS WITH CURRENT CU FIELD. HOWEVER...GIVEN
INHERITED TIMING OF TEMPO GROUP AND LOW CONFIDENCE...REMOVED
MENTION OF ANY CONVECTION FROM BOTH SITES. TRENDS WILL BE
MONITORED FOR INCLUSION OF CONVECTION ONCE AGAIN IN LATER
AMENDMENTS/00Z TAFS.
HAVE ALSO PUSHED BACK MAIN WIND SHIFT WITH COLD FRONT WITH SOMEWHAT
SLOWER ARRIVAL INITIALLY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT FROM THURSDAY AFTERNOON THROUGH LATE
FRIDAY NIGHT FOR INZ003.
MI...BEACH HAZARDS STATEMENT FROM THURSDAY AFTERNOON THROUGH LATE
FRIDAY NIGHT FOR MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 2 PM THURSDAY TO 6 AM EDT SATURDAY FOR
LMZ043-046.
&&
$$
SYNOPSIS...FISHER
SHORT TERM...FISHER
LONG TERM...T
AVIATION...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
104 PM EDT Wed Sep 11 2013
...Updated Aviation Discussion...
...Forecast Update...
Issued at 100 PM EDT Wed Sep 11 2013
Deformation axis continues to be oriented in a SW-NE
fashion...generally from just NW of Bowling Green to the NW of
Lexington. PW analysis from the mesoscale analysis suggest highest
slug of moisture is just to the south and east of this axis.
Showers and thunderstorms have been trying to develop along this
boundary, but they have struggled a bit with their vertical
structure. The storms have pulsed up and then quickly diminished
but have put out some good rains in their duration. Weak steering
flow has led to more of a chaotic motion with convection generally
drifting along cool outflow boundaries. As the afternoon wears on,
increased solar insolation should result in more instability being
generated with convection resulting due to differential heating and
mesoscale outflows intersecting each other. Best coverage looks to
be across KY in areas south of the Ohio River through the
afternoon. So plan on keeping the 40 PoP going with slightly lesser
PoPs across southern Indiana. May bump up coverage a bit down
across southern KY...mainly SE of a line from BWG to LEX.
Widespread Cu field and mid-level clouds have kept temperatures down
a bit. Afternoon highs in the mid-upper 80s still look likely.
Best shot at 90s actually looks to be across the north and northwest
sections where full insolation is taking place. However,
yesterday`s rainfall and resultant wet ground may keep readings a
couple of degrees cooler.
Update issued at 1019 AM EDT Wed Sep 11 2013
Morning water vapor imagery shows what appears to be a deformation
axis across central KY this morning. This deformation is
superimposed on top of a surface moisture convergence axis that
stretches from SW TN through NE KY. Combination of mid-level
cloudiness and developing Cu have kept temperatures down a little
bit over the central and western sections of the forecast
area...while clear slot over our eastern sections is allowing
destabilization to take place. Temperatures were generally in the
middle to upper 70s.
Convection has already started to pop in the areas where a weaker
cap is in place. Convection was noted up around the Dayton OH area
with a secondary batch developing just northwest of Nashville TN.
Expect the area between these two points to gradually fill in with
convection this afternoon. Unlike yesterday, the highest coverage
of PoPs will likely be along and east of I-65 this afternoon and
evening. Convection is not forecast to be severe in nature.
However, high atmospheric moisture content will result in
low-centroid efficient rainers with gusty winds and quite a bit of
CG lightning.
Current forecast has these ideas well covered and only a minor
grid/forecast update was performed...mainly to lower temperatures
slightly in the hourly T/Td to better match current observations.
Highs today look to be a few degrees cooler than Tuesday with
readings generally in the upper 80s...though a few spots may hit the
lower 90s.
.SHORT TERM (Now through Thursday)...
Issued at 310 AM EDT Wed Sep 11 2013
This morning area obs show light patchy fog. Expect this light fog
to continue to develop and persist through the pre-dawn hours
especially in fog prone areas and locations where it rained
yesterday. Don`t expect to see any dense fog as winds aloft are
mixy.
For the rest of the day, expect convection to develop this morning
over southwest Indiana/southern IL/western KY and spread eastward
through the morning hours to at least Louisville/Bowling Green and
then closer to Lexington by early afternoon. Did go ahead and bump
up timing on POPs based on 0Z NAM and latest RAP guidance. These
models did a good job with yesterday`s convection, and both seem to
agree with an area of moisture convergence and isentropic lift
developing early this morning to kick off storms. This matches SPC
deep moisture convergence mesoanalysis well. Once convection gets
going, the environment looks favorable for strong storms similar to
yesterday. The strongest storms may contain wind gusts up to 40
mph, torrential rainfall, and frequent lightning. Slow storm
motions today combined with heavy rainfall may cause minor flooding
issues especially in areas that received a lot of rainfall
yesterday. With anticipated convection a little earlier than
previously thought, did go on the cooler side of temps for highs
today especially over central KY which will probably be cloudy or
rainy much of the late morning and afternoon hours. Southern
Indiana may clear out early enough to cause temps to rebound near
peak heating. Therefore will go with a gradient of lower 90s across
southern Indiana to mid 80s over portions of central KY.
Expect a dry period tonight as today`s convection will decline with
the loss of diurnal heating/instability. Low temps will remain mild
in the upper 60s and lower 70s.
For Thurs, a cold front will cross the area bringing sct-numerous
storms. With good instability and better wind shear along the base
of an upper level trough, we`ll likely see better storm
organization. With 0-6 km bulk shear values ranging from 25-35 kts,
multicells and perhaps some bowing segments may be possible. Steep
lapse rates and dry lower levels are supportive of a damaging wind
threat. As previously mentioned, though, the bulk of the better
wind shear values looks to lag behind the main line of convection
limiting the possibility for widespread damaging winds. Still will
need to keep an eye on the potential for severe storms Thurs. With
PWATs remaining high, storms will likely contain torrential rainfall
although they should have more movement to them than storms today.
Frequent lightning will also be likely. With the front gradually
making its way south through the area on Thurs providing for plenty
of clouds and on and off convection, temps should be limited to the
mid 80s for highs.
.LONG TERM (Thursday night through Tuesday)...
Issued at 313 AM EDT Wed Sep 11 2013
Thursday night - Sunday night:
A big cooldown is coming this weekend after the passage of a cold
front Thursday/Thursday night. Have left some lingering chances for
precip in the forecast for the beginning half of Thursday night
primarily for southern KY as the front makes its way south and out
of the forecast area. By sunrise Friday morning, the rain will have
completely exited, leaving skies to clear and much cooler temps
behind. Afternoon highs are currently forecast to range from the low
to mid 70s, continuing on the same track of utilizing raw model
guidance as did the previous forecaster. Regardless of exactly how
cool highs will be for both Friday and Saturday, NCEP 850mb
temperature ensemble guidance clearly depicts the probability of
below normal anomalies at or greater than 1 standard deviation. As
surface high pressure of Canadian origin settles in over the Ohio
Valley by Saturday, have gone just a couple of degrees cooler on
Saturday versus Friday, which means that portions of the Bluegrass
region could potentially struggle to reach the 70 degree mark. Am a
little concerned that this could be a bit too low but given the
lowering sun angles for this time of year and the fact that we are
inching closer to autumn, am sticking with the raw model guidance
currently provided. This means that under plenty of nighttime
radiational cooling, lows will flirt with the 50 degree mark for
Friday and Saturday night with some notoriously cooler spots
potentially dipping down into the upper 40s. Will certainly need to
continue to monitor model trends and the incoming CAA to nail down
specific highs and lows. By Sunday, the strong surface high will
begin to weaken its grip over the Ohio Valley and traverse eastward,
off of the eastern seaboard. This allows for southerly flow to
recommence and will begin to be felt as highs on Sunday reach the
upper 70s. Sunday night lows will respond, only dropping into the
upper 50s to lower 60s.
Monday - Tuesday night:
Models diverge from each other for this time period as the ECMWF
shows a stronger upper ridge over the Deep South extending into our
neck of the woods whereas the GFS generally keeps us under zonal
flow at the 500mb level with slight perturbations rippling through
early next week. At the surface, it appears as though the region
could see the next fropa coming through on Monday but then
potentially stalling out in the vicinity of the KY-TN border.
Significant differences temporally and spatially yield a low
confidence forecast at this juncture. A few members of the GEFS hint
at precip on Monday and given that we`ll see an uptick in
lower-level moisture under southerly flow, cannot entirely rule out
the possibility of at least diurnally-driven convection on Monday
afternoon and have therefore introduced slight chance PoPs as such.
Have kept Tuesday/Tuesday night dry area-wide for now as the front
potentially remains to the south of the forecast area. Temps look to
rebound to near normal for this time frame.
&&
.AVIATION (18Z TAF Update)...
Issued at 103 PM EDT Wed Sep 11 2013
Main aviation concern will be afternoon convective coverage.
Mid-level deformation axis coincident with surface moisture
convergence axis from near KBWG to KLEX will serve as a focus for
scattered convection this afternoon. At this time, it appears that
KBWG and KLEX will likely have thunder in the vicinity this
afternoon while KSDF may have a lesser amount of coverage.
Convection is expected to diminish after sunset this evening with
skies going clear to partly cloudy. Patchy fog will also be
possible at KBWG and KLEX if the terminals get appreciable rainfall
this afternoon.
Surface winds will remain out of the southwest at 6-8kts this
afternoon and then become light and variable overnight.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........MJ
Short Term.....AMS
Long Term......lg
Aviation.......MJ
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1020 AM EDT Wed Sep 11 2013
...Forecast Update...
Issued at 1019 AM EDT Wed Sep 11 2013
Morning water vapor imagery shows what appears to be a deformation
axis across central KY this morning. This deformation is
superimposed on top of a surface moisture convergence axis that
stretches from SW TN through NE KY. Combination of mid-level
cloudiness and developing Cu have kept temperatures down a little
bit over the central and western sections of the forecast
area...while clear slot over our eastern sections is allowing
destabilization to take place. Temperatures were generally in the
middle to upper 70s.
Convection has already started to pop in the areas where a weaker
cap is in place. Convection was noted up around the Dayton OH area
with a secondary batch developing just northwest of Nashville TN.
Expect the area between these two points to gradually fill in with
convection this afternoon. Unlike yesterday, the highest coverage
of PoPs will likely be along and east of I-65 this afternoon and
evening. Convection is not forecast to be severe in nature.
However, high atmospheric moisture content will result in
low-centroid efficient rainers with gusty winds and quite a bit of
CG lightning.
Current forecast has these ideas well covered and only a minor
grid/forecast update was performed...mainly to lower temperatures
slightly in the hourly T/Td to better match current observations.
Highs today look to be a few degrees cooler than Tuesday with
readings generally in the upper 80s...though a few spots may hit the
lower 90s.
.SHORT TERM (Now through Thursday)...
Issued at 310 AM EDT Wed Sep 11 2013
This morning area obs show light patchy fog. Expect this light fog
to continue to develop and persist through the pre-dawn hours
especially in fog prone areas and locations where it rained
yesterday. Don`t expect to see any dense fog as winds aloft are
mixy.
For the rest of the day, expect convection to develop this morning
over southwest Indiana/southern IL/western KY and spread eastward
through the morning hours to at least Louisville/Bowling Green and
then closer to Lexington by early afternoon. Did go ahead and bump
up timing on POPs based on 0Z NAM and latest RAP guidance. These
models did a good job with yesterday`s convection, and both seem to
agree with an area of moisture convergence and isentropic lift
developing early this morning to kick off storms. This matches SPC
deep moisture convergence mesoanalysis well. Once convection gets
going, the environment looks favorable for strong storms similar to
yesterday. The strongest storms may contain wind gusts up to 40
mph, torrential rainfall, and frequent lightning. Slow storm
motions today combined with heavy rainfall may cause minor flooding
issues especially in areas that received a lot of rainfall
yesterday. With anticipated convection a little earlier than
previously thought, did go on the cooler side of temps for highs
today especially over central KY which will probably be cloudy or
rainy much of the late morning and afternoon hours. Southern
Indiana may clear out early enough to cause temps to rebound near
peak heating. Therefore will go with a gradient of lower 90s across
southern Indiana to mid 80s over portions of central KY.
Expect a dry period tonight as today`s convection will decline with
the loss of diurnal heating/instability. Low temps will remain mild
in the upper 60s and lower 70s.
For Thurs, a cold front will cross the area bringing sct-numerous
storms. With good instability and better wind shear along the base
of an upper level trough, we`ll likely see better storm
organization. With 0-6 km bulk shear values ranging from 25-35 kts,
multicells and perhaps some bowing segments may be possible. Steep
lapse rates and dry lower levels are supportive of a damaging wind
threat. As previously mentioned, though, the bulk of the better
wind shear values looks to lag behind the main line of convection
limiting the possibility for widespread damaging winds. Still will
need to keep an eye on the potential for severe storms Thurs. With
PWATs remaining high, storms will likely contain torrential rainfall
although they should have more movement to them than storms today.
Frequent lightning will also be likely. With the front gradually
making its way south through the area on Thurs providing for plenty
of clouds and on and off convection, temps should be limited to the
mid 80s for highs.
.LONG TERM (Thursday night through Tuesday)...
Issued at 313 AM EDT Wed Sep 11 2013
Thursday night - Sunday night:
A big cooldown is coming this weekend after the passage of a cold
front Thursday/Thursday night. Have left some lingering chances for
precip in the forecast for the beginning half of Thursday night
primarily for southern KY as the front makes its way south and out
of the forecast area. By sunrise Friday morning, the rain will have
completely exited, leaving skies to clear and much cooler temps
behind. Afternoon highs are currently forecast to range from the low
to mid 70s, continuing on the same track of utilizing raw model
guidance as did the previous forecaster. Regardless of exactly how
cool highs will be for both Friday and Saturday, NCEP 850mb
temperature ensemble guidance clearly depicts the probability of
below normal anomalies at or greater than 1 standard deviation. As
surface high pressure of Canadian origin settles in over the Ohio
Valley by Saturday, have gone just a couple of degrees cooler on
Saturday versus Friday, which means that portions of the Bluegrass
region could potentially struggle to reach the 70 degree mark. Am a
little concerned that this could be a bit too low but given the
lowering sun angles for this time of year and the fact that we are
inching closer to autumn, am sticking with the raw model guidance
currently provided. This means that under plenty of nighttime
radiational cooling, lows will flirt with the 50 degree mark for
Friday and Saturday night with some notoriously cooler spots
potentially dipping down into the upper 40s. Will certainly need to
continue to monitor model trends and the incoming CAA to nail down
specific highs and lows. By Sunday, the strong surface high will
begin to weaken its grip over the Ohio Valley and traverse eastward,
off of the eastern seaboard. This allows for southerly flow to
recommence and will begin to be felt as highs on Sunday reach the
upper 70s. Sunday night lows will respond, only dropping into the
upper 50s to lower 60s.
Monday - Tuesday night:
Models diverge from each other for this time period as the ECMWF
shows a stronger upper ridge over the Deep South extending into our
neck of the woods whereas the GFS generally keeps us under zonal
flow at the 500mb level with slight perturbations rippling through
early next week. At the surface, it appears as though the region
could see the next fropa coming through on Monday but then
potentially stalling out in the vicinity of the KY-TN border.
Significant differences temporally and spatially yield a low
confidence forecast at this juncture. A few members of the GEFS hint
at precip on Monday and given that we`ll see an uptick in
lower-level moisture under southerly flow, cannot entirely rule out
the possibility of at least diurnally-driven convection on Monday
afternoon and have therefore introduced slight chance PoPs as such.
Have kept Tuesday/Tuesday night dry area-wide for now as the front
potentially remains to the south of the forecast area. Temps look to
rebound to near normal for this time frame.
&&
.AVIATION (12Z TAF Update)...
Issued at 630 AM EDT Wed Sep 11 2013
The first TAF concern will be light patchy fog near BWG/LEX this
morning. Both terminals have experienced MVFR vsbys with BWG even
dropping into the IFR cat briefly. Think that MVFR will be the
primary restriction at BWG/LEX over the next few hours.
The next concern for all TAF sites will be convection chances for
today. Since storms are anticipated to be scattered in nature
will hold off on VCTS mention. Will go ahead and use VCSH to
highlight the best time period for possible convection. 0Z NAM and
latest high-res model guidance has trended earlier with convective
development for today. According to these models showers/storms
should develop near the I-65 corridor on the nose of good isentropic
lift aloft after sunrise this morning and push eastward throughout
the afternoon hours. Thus will highlight mid morning through the
afternoon for BWG/SDF for convection chances and mainly just the
afternoon hours for LEX.
Sfc winds will remain out of the SW increasing to 6-8 kts this
afternoon.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........MJ
Short Term.....AMS
Long Term......lg
Aviation.......AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
632 AM EDT Wed Sep 11 2013
...Updated Aviation Discussion...
.SHORT TERM (Now through Thursday)...
Issued at 310 AM EDT Wed Sep 11 2013
This morning area obs show light patchy fog. Expect this light fog
to continue to develop and persist through the pre-dawn hours
especially in fog prone areas and locations where it rained
yesterday. Don`t expect to see any dense fog as winds aloft are
mixy.
For the rest of the day, expect convection to develop this morning
over southwest Indiana/southern IL/western KY and spread eastward
through the morning hours to at least Louisville/Bowling Green and
then closer to Lexington by early afternoon. Did go ahead and bump
up timing on POPs based on 0Z NAM and latest RAP guidance. These
models did a good job with yesterday`s convection, and both seem to
agree with an area of moisture convergence and isentropic lift
developing early this morning to kick off storms. This matches SPC
deep moisture convergence mesoanalysis well. Once convection gets
going, the environment looks favorable for strong storms similar to
yesterday. The strongest storms may contain wind gusts up to 40
mph, torrential rainfall, and frequent lightning. Slow storm
motions today combined with heavy rainfall may cause minor flooding
issues especially in areas that received a lot of rainfall
yesterday. With anticipated convection a little earlier than
previously thought, did go on the cooler side of temps for highs
today especially over central KY which will probably be cloudy or
rainy much of the late morning and afternoon hours. Southern
Indiana may clear out early enough to cause temps to rebound near
peak heating. Therefore will go with a gradient of lower 90s across
southern Indiana to mid 80s over portions of central KY.
Expect a dry period tonight as today`s convection will decline with
the loss of diurnal heating/instability. Low temps will remain mild
in the upper 60s and lower 70s.
For Thurs, a cold front will cross the area bringing sct-numerous
storms. With good instability and better wind shear along the base
of an upper level trough, we`ll likely see better storm
organization. With 0-6 km bulk shear values ranging from 25-35 kts,
multicells and perhaps some bowing segments may be possible. Steep
lapse rates and dry lower levels are supportive of a damaging wind
threat. As previously mentioned, though, the bulk of the better
wind shear values looks to lag behind the main line of convection
limiting the possibility for widespread damaging winds. Still will
need to keep an eye on the potential for severe storms Thurs. With
PWATs remaining high, storms will likely contain torrential rainfall
although they should have more movement to them than storms today.
Frequent lightning will also be likely. With the front gradually
making it`s way south through the area on Thurs providing for plenty
of clouds and on and off convection, temps should be limited to the
mid 80s for highs.
.LONG TERM (Thursday night through Tuesday)...
Issued at 313 AM EDT Wed Sep 11 2013
Thursday night - Sunday night:
A big cooldown is coming this weekend after the passage of a cold
front Thursday/Thursday night. Have left some lingering chances for
precip in the forecast for the beginning half of Thursday night
primarily for southern KY as the front makes its way south and out
of the forecast area. By sunrise Friday morning, the rain will have
completely exited, leaving skies to clear and much cooler temps
behind. Afternoon highs are currently forecast to range from the low
to mid 70s, continuing on the same track of utilizing raw model
guidance as did the previous forecaster. Regardless of exactly how
cool highs will be for both Friday and Saturday, NCEP 850mb
temperature ensemble guidance clearly depicts the probability of
below normal anomalies at or greater than 1 standard deviation. As
surface high pressure of Canadian origin settles in over the Ohio
Valley by Saturday, have gone just a couple of degrees cooler on
Saturday versus Friday, which means that portions of the Bluegrass
region could potentially struggle to reach the 70 degree mark. Am a
little concerned that this could be a bit too low but given the
lowering sun angles for this time of year and the fact that we are
inching closer to autumn, am sticking with the raw model guidance
currently provided. This means that under plenty of nighttime
radiational cooling, lows will flirt with the 50 degree mark for
Friday and Saturday night with some notoriously cooler spots
potentially dipping down into the upper 40s. Will certainly need to
continue to monitor model trends and the incoming CAA to nail down
specific highs and lows. By Sunday, the strong surface high will
begin to weaken its grip over the Ohio Valley and traverse eastward,
off of the eastern seaboard. This allows for southerly flow to
recommence and will begin to be felt as highs on Sunday reach the
upper 70s. Sunday night lows will respond, only dropping into the
upper 50s to lower 60s.
Monday - Tuesday night:
Models diverge from each other for this time period as the ECMWF
shows a stronger upper ridge over the Deep South extending into our
neck of the woods whereas the GFS generally keeps us under zonal
flow at the 500mb level with slight perturbations rippling through
early next week. At the surface, it appears as though the region
could see the next fropa coming through on Monday but then
potentially stalling out in the vicinity of the KY-TN border.
Significant differences temporally and spatially yield a low
confidence forecast at this juncture. A few members of the GEFS hint
at precip on Monday and given that we`ll see an uptick in
lower-level moisture under southerly flow, cannot entirely rule out
the possibility of at least diurnally-driven convection on Monday
afternoon and have therefore introduced slight chance PoPs as such.
Have kept Tuesday/Tuesday night dry area-wide for now as the front
potentially remains to the south of the forecast area. Temps look to
rebound to near normal for this time frame.
&&
.AVIATION (12Z TAF Update)...
Issued at 630 AM EDT Wed Sep 11 2013
The first TAF concern will be light patchy fog near BWG/LEX this
morning. Both terminals have experienced MVFR vsbys with BWG even
dropping into the IFR cat briefly. Think that MVFR will be the
primary restriction at BWG/LEX over the next few hours.
The next concern for all TAF sites will be convection chances for
today. Since storms are anticipated to be scattered in nature
will hold off on VCTS mention. Will go ahead and use VCSH to
highlight the best time period for possible convection. 0Z NAM and
latest high-res model guidance has trended earlier with convective
development for today. According to these models showers/storms
should develop near the I-65 corridor on the nose of good isentropic
lift aloft after sunrise this morning and push eastward throughout
the afternoon hours. Thus will highlight mid morning through the
afternoon for BWG/SDF for convection chances and mainly just the
afternoon hours for LEX.
Sfc winds will remain out of the SW increasing to 6-8 kts this
afternoon.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Short Term........AMS
Long Term.........lg
Aviation..........AMS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
319 AM EDT Wed Sep 11 2013
.SHORT TERM (Now through Thursday)...
Issued at 310 AM EDT Wed Sep 11 2013
This morning area obs show light patchy fog. Expect this light fog
to continue to develop and persist through the pre-dawn hours
especially in fog prone areas and locations where it rained
yesterday. Don`t expect to see any dense fog as winds aloft are
mixy.
For the rest of the day, expect convection to develop this morning
over southwest Indiana/southern IL/western KY and spread eastward
through the morning hours to at least Louisville/Bowling Green and
then closer to Lexington by early afternoon. Did go ahead and bump
up timing on POPs based on 0Z NAM and latest RAP guidance. These
models did a good job with yesterday`s convection, and both seem to
agree with an area of moisture convergence and isentropic lift
developing early this morning to kick off storms. This matches SPC
deep moisture convergence mesoanalysis well. Once convection gets
going, the environment looks favorable for strong storms similar to
yesterday. The strongest storms may contain wind gusts up to 40
mph, torrential rainfall, and frequent lightning. Slow storm
motions today combined with heavy rainfall may cause minor flooding
issues especially in areas that received a lot of rainfall
yesterday. With anticipated convection a little earlier than
previously thought, did go on the cooler side of temps for highs
today especially over central KY which will probably be cloudy or
rainy much of the late morning and afternoon hours. Southern
Indiana may clear out early enough to cause temps to rebound near
peak heating. Therefore will go with a gradient of lower 90s across
southern Indiana to mid 80s over portions of central KY.
Expect a dry period tonight as today`s convection will decline with
the loss of diurnal heating/instability. Low temps will remain mild
in the upper 60s and lower 70s.
For Thurs, a cold front will cross the area bringing sct-numerous
storms. With good instability and better wind shear along the base
of an upper level trough, we`ll likely see better storm
organization. With 0-6 km bulk shear values ranging from 25-35 kts,
multicells and perhaps some bowing segments may be possible. Steep
lapse rates and dry lower levels are supportive of a damaging wind
threat. As previously mentioned, though, the bulk of the better
wind shear values looks to lag behind the main line of convection
limiting the possibility for widespread damaging winds. Still will
need to keep an eye on the potential for severe storms Thurs. With
PWATs remaining high, storms will likely contain torrential rainfall
although they should have more movement to them than storms today.
Frequent lightning will also be likely. With the front gradually
making it`s way south through the area on Thurs providing for plenty
of clouds and on and off convection, temps should be limited to the
mid 80s for highs.
.LONG TERM (Thursday night through Tuesday)...
Issued at 313 AM EDT Wed Sep 11 2013
Thursday night - Sunday night:
A big cooldown is coming this weekend after the passage of a cold
front Thursday/Thursday night. Have left some lingering chances for
precip in the forecast for the beginning half of Thursday night
primarily for southern KY as the front makes its way south and out
of the forecast area. By sunrise Friday morning, the rain will have
completely exited, leaving skies to clear and much cooler temps
behind. Afternoon highs are currently forecast to range from the low
to mid 70s, continuing on the same track of utilizing raw model
guidance as did the previous forecaster. Regardless of exactly how
cool highs will be for both Friday and Saturday, NCEP 850mb
temperature ensemble guidance clearly depicts the probability of
below normal anomalies at or greater than 1 standard deviation. As
surface high pressure of Canadian origin settles in over the Ohio
Valley by Saturday, have gone just a couple of degrees cooler on
Saturday versus Friday, which means that portions of the Bluegrass
region could potentially struggle to reach the 70 degree mark. Am a
little concerned that this could be a bit too low but given the
lowering sun angles for this time of year and the fact that we are
inching closer to autumn, am sticking with the raw model guidance
currently provided. This means that under plenty of nighttime
radiational cooling, lows will flirt with the 50 degree mark for
Friday and Saturday night with some notoriously cooler spots
potentially dipping down into the upper 40s. Will certainly need to
continue to monitor model trends and the incoming CAA to nail down
specific highs and lows. By Sunday, the strong surface high will
begin to weaken its grip over the Ohio Valley and traverse eastward,
off of the eastern seaboard. This allows for southerly flow to
recommence and will begin to be felt as highs on Sunday reach the
upper 70s. Sunday night lows will respond, only dropping into the
upper 50s to lower 60s.
Monday - Tuesday night:
Models diverge from each other for this time period as the ECMWF
shows a stronger upper ridge over the Deep South extending into our
neck of the woods whereas the GFS generally keeps us under zonal
flow at the 500mb level with slight perturbations rippling through
early next week. At the surface, it appears as though the region
could see the next fropa coming through on Monday but then
potentially stalling out in the vicinity of the KY-TN border.
Significant differences temporally and spatially yield a low
confidence forecast at this juncture. A few members of the GEFS hint
at precip on Monday and given that we`ll see an uptick in
lower-level moisture under southerly flow, cannot entirely rule out
the possibility of at least diurnally-driven convection on Monday
afternoon and have therefore introduced slight chance PoPs as such.
Have kept Tuesday/Tuesday night dry area-wide for now as the front
potentially remains to the south of the forecast area. Temps look to
rebound to near normal for this time frame.
&&
.AVIATION (06Z TAF Update)...
Issued at 135 AM EDT Wed Sep 11 2013
The first TAF concern will be light patchy fog near BWG/LEX this
morning. Both terminals have experienced lowering vsbys early this
morning and should continue to gradually lower into the MVFR cat
through the early morning hours. Think that mixy winds just off the
sfc will prevent any vsbys lower than MVFR.
The next concern for all TAF sites will be convection chances for
today. Greater convective coverage is expected over the area today,
however, with storms still anticipated to be scattered in nature
will hold off on VCTS mention. Will go ahead and use VCSH to
highlight the best time period for possible convection though. 0Z
NAM and latest high-res model guidance has trended earlier with
convective development for today. According to these models
showers/storms should develop near the I-65 corridor on the nose of
good isentropic lift aloft after sunrise this morning and push
eastward throughout the afternoon hours. Thus will highlight mid
morning through the afternoon for BWG/SDF for convection chances and
mainly just the afternoon hours for LEX. Will probably try to pin
down t-storm chances at the 12Z issuance should newest model data
and environmental data continue to support early convective
develop. Will need to address any possible fog concerns for
tomorrow morning with the 12Z TAF issuance as well.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Short Term........AMS
Long Term.........lg
Aviation..........AMS
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
850 PM EDT THU SEP 12 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION EARLY TONIGHT WITH MUCH COOLER
AND LESS HUMID CONDITIONS FOR FRIDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY/...
QUICK UPDATE AT 845PM TO SPEED UP POPS WITH STORMS COMING ACROSS
LAKE ERIE AND DEVELOPING ACROSS WESTERN OHIO. ALSO ADDED THUNDER
DURING THE EVENING HOURS...BUT THINK THUNDER SHOULD NOT BE AN
ISSUE AFTER MIDNIGHT.
WITH 745PM UPDATE...BACKED OFF POPS ONCE AGAIN DURING THE EARLY
EVENING HOURS. HOWEVER...HAVE UPPED POPS A BIT FOR THE LATE
EVENING HOURS INTO THE OVERNIGHT WITH UPSTREAM DEVELOPMENT OF
SHOWERS ASSOCIATED WITH AN UPPER LEVEL SHORTWAVE. LATEST RUNS OF
THE HRRR AND RAP ARE DEVELOPING A BIT MORE RAIN THAN THE SYNOPTIC
MODELS. COULD BE A LITTLE BIT OF ENHANCEMENT DUE TO COLDER AIR
MOVING OVER A WARMER LAKE ERIE...ALTHOUGH THE MECHANISM WILL BE
FROM THE SHORTWAVE OVERNIGHT.
BY FRIDAY THE SHORTWAVE WILL HAVE MOVED TO THE EAST...WITH
ANY SCATTERED SHOWERS CONTINUING MORE THE RESULT OF LAKE
ENHANCEMENT WITH N-NW FLOW. WINDS MAY NOT HAVE ENOUGH OF A
WESTERLY COMPONENT TO ALLOW FOR MUCH PRECIPITATION...ALTHOUGH LOW
LEVELS WILL STILL HAVE PLENTY OF MOISTURE TO KEEP SKIES CLOUDY.
EXPECT SOME BREAKS IN THE CLOUDS FRIDAY AFTN...ESPECIALLY OVER
EASTERN OHIO SINCE WINDS THERE ARE MORE NERLY AND IN CLOSER
PROXIMITY TO THE SFC RIDGE. GFS40 BIAS CORRECTED GRIDS WERE THE
BASELINE FOR TEMPS WITH MINOR TWEAKS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
UPPER LEVEL TROUGH WILL SWING EASTWARD FRIDAY NIGHT PULLING THE
COLDEST AIR OVER THE UPPER OHIO VALLEY. EXPECT CLOUDS TO HOLD ON
A GOOD PORTION OF FRIDAY NIGHT...WITH WELL BELOW NORMAL TEMPS.
RISING HEIGHTS ALOFT AND SURFACE HIGH WILL ALLOW FOR A COOL AND
COMFORTABLE SAT. STILL EXPECT HIGHS IN THE MID 60S WITH LATEST
MODEL DATA SHOWING 85H TEMPS AROUND +4. LIGHT WINDS AND MAINLY
CLEAR SKIES WILL ALLOW TEMPERATURES TO FALL INTO THE 40S SATURDAY
NIGHT. AS THE SURFACE RIDGE MOVES EAST WARM ADVECTION SUNDAY WILL
PUSH HIGH TEMPERATURES INTO THE UPPER 60S NORTH TO LOWER 70S FAR
SOUTH WITH CONTINUED SUNSHINE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A MOISTURE STARVED COLD FRONT WILL CROSS THE REGION SUN NIGHT
INTO EARLY MONDAY WITH AN ISOLATED SHOWER AT BEST. OTHERWISE
TEMPERATURES WILL BE MODERATING TOWARD NORMAL BY MID WEEK AS THE
UPPER LEVEL FLOW BECOMES ZONAL. AN APPROACHING SHORTWAVE WITH WARM
ADVECTION WILL BRING THE CHANCE FOR SHOWERS THURSDAY.
&&
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
CONDITIONS WL IMPROVE THIS EVE AS SFC WND SHIFTS TO THE NW WITH
PASSAGE OF A REINFORCING CDFNT. RESIDUAL SHWRS WL DIMINISH AND
MVFR CIGS WL LIFT AS DRIER AIR ADVECTS OVR THE UPR OH REGION.
HOWEVER...MVFR STRATOCU AND MORE SHWR DVLPMNT IS ANTICIPATED LTR
TNGT/EARLY FRIDAY AS COLD ADVCTN STEEPENS THE MIXING LYR AND AS A
TRAILING DISTURBANCE MOVES OFF THE GREAT LAKES.
ISOLD-SCT SHWRS ARE POSSIBLE AGAIN ON FRIDAY AFTN AS THE SFC
RECOUPLES...BUT LACK OF CONFIDENCE IN ACTUAL PLACEMENT PRECLUDES A
MENTION IN TAFS FOR THAT TIME FRAME. NEVERTHELESS...OVRALL
IMPROVEMENT TO VFR IS ANTICIPATED AS FRIDAY AFTN PROGRESSES.
.OUTLOOK.../18Z FRIDAY THROUGH TUESDAY/...
NO WIDESPREAD IFR WEATHER FORECAST.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
745 PM EDT THU SEP 12 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION EARLY TONIGHT WITH MUCH COOLER
AND LESS HUMID CONDITIONS FOR FRIDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY/...
WITH 745PM UPDATE...BACKED OFF POPS ONCE AGAIN DURING THE EARLY
EVENING HOURS. HOWEVER...HAVE UPPED POPS A BIT FOR THE LATE
EVENING HOURS INTO THE OVERNIGHT WITH UPSTREAM DEVELOPMENT OF
SHOWERS ASSOCIATED WITH AN UPPER LEVEL SHORTWAVE. LATEST RUNS OF
THE HRRR AND RAP ARE DEVELOPING A BIT MORE RAIN THAN THE SYNOPTIC
MODELS. COULD BE A LITTLE BIT OF ENHANCEMENT DUE TO COLDER AIR
MOVING OVER A WARMER LAKE ERIE...ALTHOUGH THE MECHANISM WILL BE
FROM THE SHORTWAVE OVERNIGHT.
BY FRIDAY THE SHORTWAVE WILL HAVE MOVED TO THE EAST...WITH
ANY SCATTERED SHOWERS CONTINUING MORE THE RESULT OF LAKE
ENHANCEMENT WITH N-NW FLOW. WINDS MAY NOT HAVE ENOUGH OF A
WESTERLY COMPONENT TO ALLOW FOR MUCH PRECIPITATION...ALTHOUGH LOW
LEVELS WILL STILL HAVE PLENTY OF MOISTURE TO KEEP SKIES CLOUDY.
EXPECT SOME BREAKS IN THE CLOUDS FRIDAY AFTN...ESPECIALLY OVER
EASTERN OHIO SINCE WINDS THERE ARE MORE NERLY AND IN CLOSER
PROXIMITY TO THE SFC RIDGE. GFS40 BIAS CORRECTED GRIDS WERE THE
BASELINE FOR TEMPS WITH MINOR TWEAKS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
UPPER LEVEL TROUGH WILL SWING EASTWARD FRIDAY NIGHT PULLING THE
COLDEST AIR OVER THE UPPER OHIO VALLEY. EXPECT CLOUDS TO HOLD ON
A GOOD PORTION OF FRIDAY NIGHT...WITH WELL BELOW NORMAL TEMPS.
RISING HEIGHTS ALOFT AND SURFACE HIGH WILL ALLOW FOR A COOL AND
COMFORTABLE SAT. STILL EXPECT HIGHS IN THE MID 60S WITH LATEST
MODEL DATA SHOWING 85H TEMPS AROUND +4. LIGHT WINDS AND MAINLY
CLEAR SKIES WILL ALLOW TEMPERATURES TO FALL INTO THE 40S SATURDAY
NIGHT. AS THE SURFACE RIDGE MOVES EAST WARM ADVECTION SUNDAY WILL
PUSH HIGH TEMPERATURES INTO THE UPPER 60S NORTH TO LOWER 70S FAR
SOUTH WITH CONTINUED SUNSHINE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A MOISTURE STARVED COLD FRONT WILL CROSS THE REGION SUN NIGHT
INTO EARLY MONDAY WITH AN ISOLATED SHOWER AT BEST. OTHERWISE
TEMPERATURES WILL BE MODERATING TOWARD NORMAL BY MID WEEK AS THE
UPPER LEVEL FLOW BECOMES ZONAL. AN APPROACHING SHORTWAVE WITH WARM
ADVECTION WILL BRING THE CHANCE FOR SHOWERS THURSDAY.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
CONDITIONS WL IMPROVE THIS EVE AS SFC WND SHIFTS TO THE NW WITH
PASSAGE OF A REINFORCING CDFNT. RESIDUAL SHWRS WL DIMINISH AND
MVFR CIGS WL LIFT AS DRIER AIR ADVECTS OVR THE UPR OH REGION.
HOWEVER...MVFR STRATOCU DVLPMNT IS ANTICIPATED LTR TNGT/EARLY
FRIDAY AS COLD ADVCTN STEEPENS THE MIXING LYR. ISOLD-SCT SHWRS ARE
POSSIBLE ON FRIDAY AS THE SFC RECOUPLES...BUT LACK OF CONFIDENCE
IN ACTUAL PLACEMENT PRECLUDES A MENTION IN TAFS.
NEVERTHELESS...OVRALL IMPROVEMENT TO VFR IS ANTICIPATED BY FRIDAY
AFTN.
.OUTLOOK.../18Z FRIDAY THROUGH TUESDAY/...
NO WIDESPREAD IFR WEATHER FORECAST.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
516 AM EDT WED SEP 11 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 408 PM EDT TUE SEP 10 2013
PER WATER VAPOR IMAGERY AND RUC ANALYSIS...A SHORTWAVE MOVING ACROSS
NRN ONTARIO AND LAKE SUPERIOR THIS AFTERNOON COMBINED WITH UPR DIV
IN RIGHT ENTRANCE REGION OF ASSOC 100+ KT 3H JET HAVE HELPED SUSTAIN
A COUPLE DIFFERENT BATCHES OF SHRA WHICH HAVE MOVED OVER THE WEST
HALF OF UPPER MI THIS AFTERNOON. UPSLOPE FOG WHICH PLAGUED THE
KEWEENAW INTO THE EARLY AFTERNOON HOURS LOOKS LIKE IT HAS FINALLY
LIFTED PER SFC OBS AND WEB CAMS BUT STRATUS CLOUDS STILL REMAIN. AT
THE SFC...A COUPLE OF SFC TROUGHS EXTEND FM LOW PRES CENTERED NE OF
LAKE SUPERIOR...ONE TROUGH EXTENDS INTO ERN AND SCNTRL UPR MI WHILE
ANOTHER IS STILL SITUATED OVER FAR NRN LAKE SUPERIOR AND ONTARIO.
TONIGHT...EXPECT AREA OF SHOWERS NOW EXTENDING FM IRON COUNTY INTO
WRN MQT COUNTY TO MOVE SLOWLY EAST OVER THE NEXT COUPLE OF HOURS AND
THEN GRADUALLY DISSIPATE THIS EVENING AS 700-650 MB FGEN SLOWLY
WEAKENS. THERE IS A CONCERN THAT A STRONG TO POSSIBLY SVR STORM
COULD FORM OVER THE ERN HALF OF UPPER MI IN THE NEXT FEW HOURS.
PARTIAL SUNSHINE HAS ALLOWED MLCAPES TO BUILD UP TO AROUND 2000
J/KG. THIS ALONG WITH EFFECTIVE SHEAR OF 50-60 KT AND ENHANCED
CONVERGENCE ALONG SFC TROUGH COULD TRIGGER STORMS OVER ERN UPPER MI
LATE AFTERNOON INTO EARLY EVENING. THIS WILL NEED TO BE CLOSELY
MONITORED ON THE EVENING SHIFT.
THE OTHER CONCERN TONIGHT IS THE POTENTIAL FOR MORE FOG TO FORM LATE
EVENING INTO OVERNIGHT HRS AS TEMPS RADIATE THROUGH UPPER 50S/LOWER
60S DEWPOINTS UNDER LIGHT WINDS AND PARTIAL CLEARING. HAVE EXPANDED
MENTION OF PATCHY TO AREAS OF FOG ACROSS THE CWA AND WOULD NOT BE
SURPRISED TO SEE SOME LOCALLY DENSE FOG AT SOME LOCATIONS.
WEDNESDAY...ANOTHER SHORTWAVE NOW DROPPING DOWN FROM NRN
SASKATCHEWAN/NRN MANITOBA WILL HELP PUSH FRONTAL BOUNDARY INTO THE
AREA. SCNTRL AND ERN UPR MI WILL AGAIN HAVE BEST CHC OF AFTERNOON
SHRA/TSRA AS MLCAPES ARE FCST BY MODELS TO INCREASE TO 500-1000
J/KG. WILL INCLUDE HIGHER CHC 40 PCT POPS OVER THIS AREA. WITH WEAK
DOWNSLOPE WRLY FLOW INTO THE BAY OF GREEN BAY...EXPECT THE WARMEST
HIGH TEMPS (LOWER TO MID 80S) OVER MNM COUNTY. ELSEWHERE MAX TEMPS
WILL GENERALLY BE IN THE 70S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 438 AM EDT WED SEP 11 2013
THRU MUCH OF THE LONG TERM...PATTERN WILL CONTINUE TO BE ONE THAT
HAS BEEN COMMON IN RECENT WEEKS...A MEAN RIDGE OVER NW CANADA AND A
MEAN TROF OVER ERN N AMERICA. TOWARD THE END OF THE LONG TERM AND
INTO LATE NEXT WEEK...IT APPEARS A TROF WILL REPLACE THE NW CANADA
RIDGE. THIS COULD SPELL A PERIOD OF WARM WEATHER JUST BEYOND THE
LONG TERM. PRIOR TO THAT...MEDIUM RANGE GUIDANCE HAS AND CONTINUES
TO POINT TO 2 PERIODS WHEN THE ERN TROF WILL AMPLIFY. THE FIRST
OCCURS THU/FRI WITH THE SECOND FOLLOWING QUICKLY OVER THE WEEKEND.
SOME SHRA MAY ACCOMPANY EACH AMPLIFICATION...BUT OVERALL...THIS WILL
BE A DRY PATTERN WITH NO WIDESPREAD/SIGNIFICANT PCPN IN THE OFFING
DURING THE LONG TERM PORTION OF THE FCST. AS FOR TEMPS...THE 2
AMPLIFICATIONS OF THE ERN TROF WILL BRING 2 SHOTS OF COLD AIR INTO
THE UPPER LAKES...SENDING TEMPS BLO NORMAL AND BRINGING A REAL TASTE
OF AUTUMN TO THE AREA. BY MON...MANY INTERIOR LOCATIONS SHOULD HAVE
SEEN AT LEAST ONE NIGHT WITH SOME FROST...AND TRADITIONAL COLD SPOTS
WILL PROBABLY HAVE SEEN AT LEAST ONE NIGHT WITH A FREEZE.
BEGINNING THU...CAA PATTERN WILL BE WELL UNDERWAY AND WILL CONTINUE
THRU THE DAY AS A PAIR OF SHORTWAVES AMPLIFY THE TROF INTO THE GREAT
LAKES REGION. BY 00Z FRI...850MB TEMPS COULD BE HOVERING AROUND 0C
OVER NRN AND ERN UPPER MI. WITH SECOND OF THE 2 SHORTWAVES TRACKING
OVER FAR WRN UPPER MI...MUCH OF THE FCST AREA WILL BE ON THE
CYCLONIC SIDE OF THE SHORTWAVE TRACK/ASSOCIATED UPPER JET STREAK...
FAVORABLE FOR SCT SHRA. MODELS SHOW A BAND OF DEEP LAYER QVECTOR
CONVERGENCE PUSHING ACROSS THE AREA RIGHT WHERE IT WOULD BE EXPECTED
ON THE CYCLONIC SIDE OF THE JET STREAK/SHORTWAVE. SO...SCT SHRA LOOK
LIKE A PRETTY GOOD BET THU...ESPECIALLY OVER THE ERN 2/3RDS OF THE
FCST AREA. WITH 850MB TEMPS FALLING TO AROUND 0C ACROSS CNTRL AND
ERN LAKE SUPERIOR DURING THE TIME OF SYNOPTIC FORCING...THERE WILL
BE SOME LAKE COMPONENT TO THE SHRA...BUT REALLY MORE OF A HYBRID
TYPE COMPONENT AS STILL STRONG DAYTIME HEATING DISRUPTS NORMAL LAKE
EFFECT PROCESSES. END RESULT WILL BE MORE SHRA ACTIVITY INLAND
THAN OVER THE LAKE. OTHERWISE...THU WILL BE A COOL DAY WITH GUSTY
N/NW WINDS AND ABUNDANT CLOUD COVER. TEMPS WILL LIKELY NOT GET OUT
OF THE MID/UPPER 50S ACROSS THE N.
WITH LOSS OF DISRUPTING DAYTIME HEATING...THERE MAY BE AN UPTICK
IN MORE TRADITIONAL LOOKING LAKE EFFECT -SHRA THU NIGHT...MAINLY
OVER THE CNTRL/E UNDER NRLY FLOW WITH 850MB TEMPS FALLING TO -2 OR
-3C. HOWEVER...DEEP LAYER QVECTOR DIVERGENCE/SUBSIDENCE AND A WELL
MIXED BOUNDARY LAYER/INVERTED V LOOK ON FCST SOUNDINGS SUGGEST -SHRA
ACTIVITY PROBABLY WON`T REALLY BE MUCH MORE THAN ISOLD. ATTENTION
THEN TURNS TO FROST POTENTIAL OVER THE W. WITH HIGH PRES STILL
BUILDING TOWARD UPPER MI FROM THE NW...THERE ARE CONCERNS OVER LAKE
EFFECT CLOUD COVER. MODEL GUIDANCE SHOWS DIVERGENT LOW-LEVEL NNE
WINDS OVER THE W WHICH SUGGESTS CLOUDS MAY CLEAR OUT DURING THE
NIGHT. WILL RETAIN IDEA OF CLOUDS AT LEAST PARTIALLY CLEARING OVER
THE FAR W...ALLOWING TEMPS TO FALL INTO THE MID/UPPER 30S WITH
POTENTIAL FOR PATCHY FROST. CLOUDS WILL GRADUALLY CLEAR FROM W TO E
FRI AS SFC HIGH SETTLES INTO UPPER MI. FRI WILL BE COOL WITH HIGHS
MOSTLY IN THE MID TO UPPER 50S.
FRI NIGHT OFFERS A GOOD OPPORTUNITY FOR WIDESPREAD FROST AND ALSO A
POTENTIAL FREEZE IN SOME AREAS. HOWEVER...WITH SFC HIGH QUICKLY
EXITING TO THE SE...RETURN FLOW WILL BE DEVELOPING...PREVENTING
IDEAL RADIATIONAL COOLING THRU THE NIGHT. PRECIPITABLE WATER AROUND
50PCT OF NORMAL AND CLEAR SKIES/CALM WIND AT LEAST INITIALLY WILL
ALLOW FOR A QUICK TEMP DROP FRI EVENING...AND THIS MAY BE ENOUGH TO
RESULT IN WIDESPREAD FROST ACROSS THE INTERIOR. THE BEST CHANCE FOR
FROST AND EVEN SOME FREEZING CONDITIONS WILL BE OVER THE E AND S...
CLOSER TO DEPARTING SFC HIGH WHICH WILL ALLOW A LONGER PERIOD OF
CALM WIND. WILL INCLUDE SOME SUBFREEZING TEMPS INTO THE UPPER 20S IN
THE TRADITIONAL COLD SPOTS OVER THE E.
AS THE HIGH CONTINUES TO MOVE SE SAT AND THE NEXT SHORTWAVE/COLD
FRONT APPROACH FROM THE NW...SW WINDS WILL BRING A GOOD PUSH OF
WARMER AIR INTO THE UPPER LAKES (850MB TEMPS RETURN TO AROUND 10C).
MIXING TO AROUND 850MB YIELDS HIGHS BACK UP TO AROUND NORMAL IN THE
MID 60S TO AROUND 70F UNDER A GOOD DISPLAY OF SUNSHINE...AT LEAST FOR
THE FIRST HALF OF THE DAY.
THE NEXT SHORTWAVE AND ASSOCIATED COLD FRONT WILL MOVE ACROSS THE
AREA SAT NIGHT INTO SUN MORNING. THERE ARE ONLY MINOR TIMING
DIFFERENCES AMONG MEDIUM RANGE GUIDANCE. THE GFS HAS SHOWN VERY GOOD
CONTINUITY OVER THE LAST 4 RUNS...AND THE LATEST RUN IS IN GOOD
AGREEMENT WITH THE GEM/ECMWF. CONSENUS OF GUIDANCE INCLUDING
PREVIOUS GFS RUNS PLACES COLD FRONT BISECTING UPPER MI AT 12Z SUN.
WITH TRACK OF SHORTWAVE PASSING JUST N AND E OF THE FCST AREA...
BETTER POTENTIAL FOR PCPN WILL BE OFF TO THE N AND E OF HERE. ONLY
SCHC/LOW CHC POPS WILL CONTINUE TO BE UTILIZED...MAINLY OVERNIGHT
SAT NIGHT INTO SUN MORNING.
850MB TEMPS DON`T DROP QUITE AS MUCH AS THE PREVIOUS COLD SHOT
THU/FRI...SO POTENTIAL OF LAKE EFFECT CLOUDS/SHRA FOR SUN NIGHT INTO
MON WON`T BE AS GREAT. IN FACT...LAKE EFFECT -SHRA LOOK DOUBTFUL AT
THIS POINT. SFC HIGH SETTLING OVER THE AREA SUN NIGHT WITH DRY AIR
MASS (PRECIPITABLE WATER AROUND 50PCT OF NORMAL) WILL BRING ANOTHER
CHILLY NIGHT WITH FROST AND POSSIBLE FREEZING CONDITIONS IN THE
INTERIOR. FAVORED LOW END OF AVBL GUIDANCE FOR MIN TEMPS SUN NIGHT.
A SUNNY DAY WILL FOLLOW FOR MON. COULD BE SOME FROST CONCERNS AGAIN
MON NIGHT...DEPENDING ON HOW FAST SFC HIGH DEPARTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 141 AM EDT WED SEP 11 2013
EXPECT FOG AT ALL SITES INTO EARLY THIS MORNING...BUT EXACT COVERAGE
AND EXTENT OF FOG REMAINS UNCERTAIN. THERE IS A HIGH POTENTIAL THAT
THE EXISTING CLOUDS OVERHEAD AND TO OUR SW WILL LINGER
OVERHEAD...REDUCING THE POTENTIAL FOR SIGNIFICANT FOG. WILL LIKELY
NEED TO MAKE A FEW ADJUSTMENTS TO THE ONGOING TAFS OVERNIGHT. A COLD
FRONT WILL MOVE THROUGH THIS AFTERNOON/EVENING...AND SOME CONVECTION
IS EXPECTED ALONG THE FRONT. HAVE THE HIGHEST CONFIDENCE OF
CONVECTION AT SAW...SO INCLUDED VCSH THERE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 516 AM EDT WED SEP 11 2013
LOW PRESSURE ACROSS NORTH CENTRAL ONTARIO WILL DRAG A TROUGH/COLD
FRONT ACROSS LAKE SUPERIOR TODAY...BEFORE THE LOW SINKS ACROSS JAMES
BAY THIS EVENING AND EXITS ACROSS THE QUEBEC ON THURSDAY. IN THE
WAKE OF THE LOW...LARGE HIGH PRESSURE STRETCHING FROM CENTRAL CANADA
THROUGH THE NORTHERN PLAINS WILL SLOWLY SINK ACROSS THE UPPER GREAT
LAKES THURSDAY NIGHT THROUGH FRIDAY NIGHT. N TO NNW WINDS WILL GUST
20-30KTS THURSDAY THROUGH THURSDAY NIGHT. A FEW HIGHER PLATFORMS
COULD EXPERIENCE GALE FORCE GUSTS.
EXPECT THE HIGH PRESSURE SYSTEM TO PUSH SOUTHEASTWARD ON
SATURDAY...MAKING WAY FOR LOW PRESSURE ACROSS HUDSON BAY ON SATURDAY
TO DRAG ANOTHER TROUGH OVER LAKE SUPERIOR SATURDAY NIGHT INTO EARLY
SUNDAY. SW WINDS COULD GUST INTO THE 20-25KT RANGE SATURDAY. ANOTHER
AREA OF HIGH PRESSURE WILL SINK IN LATE SUNDAY FROM THE NORTHWEST
/WITH NW GUSTS OF 20-25KTS SUNDAY/.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...ROLFSON
AVIATION...JT/KF
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
439 AM EDT WED SEP 11 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 408 PM EDT TUE SEP 10 2013
PER WATER VAPOR IMAGERY AND RUC ANALYSIS...A SHORTWAVE MOVING ACROSS
NRN ONTARIO AND LAKE SUPERIOR THIS AFTERNOON COMBINED WITH UPR DIV
IN RIGHT ENTRANCE REGION OF ASSOC 100+ KT 3H JET HAVE HELPED SUSTAIN
A COUPLE DIFFERENT BATCHES OF SHRA WHICH HAVE MOVED OVER THE WEST
HALF OF UPPER MI THIS AFTERNOON. UPSLOPE FOG WHICH PLAGUED THE
KEWEENAW INTO THE EARLY AFTERNOON HOURS LOOKS LIKE IT HAS FINALLY
LIFTED PER SFC OBS AND WEB CAMS BUT STRATUS CLOUDS STILL REMAIN. AT
THE SFC...A COUPLE OF SFC TROUGHS EXTEND FM LOW PRES CENTERED NE OF
LAKE SUPERIOR...ONE TROUGH EXTENDS INTO ERN AND SCNTRL UPR MI WHILE
ANOTHER IS STILL SITUATED OVER FAR NRN LAKE SUPERIOR AND ONTARIO.
TONIGHT...EXPECT AREA OF SHOWERS NOW EXTENDING FM IRON COUNTY INTO
WRN MQT COUNTY TO MOVE SLOWLY EAST OVER THE NEXT COUPLE OF HOURS AND
THEN GRADUALLY DISSIPATE THIS EVENING AS 700-650 MB FGEN SLOWLY
WEAKENS. THERE IS A CONCERN THAT A STRONG TO POSSIBLY SVR STORM
COULD FORM OVER THE ERN HALF OF UPPER MI IN THE NEXT FEW HOURS.
PARTIAL SUNSHINE HAS ALLOWED MLCAPES TO BUILD UP TO AROUND 2000
J/KG. THIS ALONG WITH EFFECTIVE SHEAR OF 50-60 KT AND ENHANCED
CONVERGENCE ALONG SFC TROUGH COULD TRIGGER STORMS OVER ERN UPPER MI
LATE AFTERNOON INTO EARLY EVENING. THIS WILL NEED TO BE CLOSELY
MONITORED ON THE EVENING SHIFT.
THE OTHER CONCERN TONIGHT IS THE POTENTIAL FOR MORE FOG TO FORM LATE
EVENING INTO OVERNIGHT HRS AS TEMPS RADIATE THROUGH UPPER 50S/LOWER
60S DEWPOINTS UNDER LIGHT WINDS AND PARTIAL CLEARING. HAVE EXPANDED
MENTION OF PATCHY TO AREAS OF FOG ACROSS THE CWA AND WOULD NOT BE
SURPRISED TO SEE SOME LOCALLY DENSE FOG AT SOME LOCATIONS.
WEDNESDAY...ANOTHER SHORTWAVE NOW DROPPING DOWN FROM NRN
SASKATCHEWAN/NRN MANITOBA WILL HELP PUSH FRONTAL BOUNDARY INTO THE
AREA. SCNTRL AND ERN UPR MI WILL AGAIN HAVE BEST CHC OF AFTERNOON
SHRA/TSRA AS MLCAPES ARE FCST BY MODELS TO INCREASE TO 500-1000
J/KG. WILL INCLUDE HIGHER CHC 40 PCT POPS OVER THIS AREA. WITH WEAK
DOWNSLOPE WRLY FLOW INTO THE BAY OF GREEN BAY...EXPECT THE WARMEST
HIGH TEMPS (LOWER TO MID 80S) OVER MNM COUNTY. ELSEWHERE MAX TEMPS
WILL GENERALLY BE IN THE 70S.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 438 AM EDT WED SEP 11 2013
THRU MUCH OF THE LONG TERM...PATTERN WILL CONTINUE TO BE ONE THAT
HAS BEEN COMMON IN RECENT WEEKS...A MEAN RIDGE OVER NW CANADA AND A
MEAN TROF OVER ERN N AMERICA. TOWARD THE END OF THE LONG TERM AND
INTO LATE NEXT WEEK...IT APPEARS A TROF WILL REPLACE THE NW CANADA
RIDGE. THIS COULD SPELL A PERIOD OF WARM WEATHER JUST BEYOND THE
LONG TERM. PRIOR TO THAT...MEDIUM RANGE GUIDANCE HAS AND CONTINUES
TO POINT TO 2 PERIODS WHEN THE ERN TROF WILL AMPLIFY. THE FIRST
OCCURS THU/FRI WITH THE SECOND FOLLOWING QUICKLY OVER THE WEEKEND.
SOME SHRA MAY ACCOMPANY EACH AMPLIFICATION...BUT OVERALL...THIS WILL
BE A DRY PATTERN WITH NO WIDESPREAD/SIGNIFICANT PCPN IN THE OFFING
DURING THE LONG TERM PORTION OF THE FCST. AS FOR TEMPS...THE 2
AMPLIFICATIONS OF THE ERN TROF WILL BRING 2 SHOTS OF COLD AIR INTO
THE UPPER LAKES...SENDING TEMPS BLO NORMAL AND BRINGING A REAL TASTE
OF AUTUMN TO THE AREA. BY MON...MANY INTERIOR LOCATIONS SHOULD HAVE
SEEN AT LEAST ONE NIGHT WITH SOME FROST...AND TRADITIONAL COLD SPOTS
WILL PROBABLY HAVE SEEN AT LEAST ONE NIGHT WITH A FREEZE.
BEGINNING THU...CAA PATTERN WILL BE WELL UNDERWAY AND WILL CONTINUE
THRU THE DAY AS A PAIR OF SHORTWAVES AMPLIFY THE TROF INTO THE GREAT
LAKES REGION. BY 00Z FRI...850MB TEMPS COULD BE HOVERING AROUND 0C
OVER NRN AND ERN UPPER MI. WITH SECOND OF THE 2 SHORTWAVES TRACKING
OVER FAR WRN UPPER MI...MUCH OF THE FCST AREA WILL BE ON THE
CYCLONIC SIDE OF THE SHORTWAVE TRACK/ASSOCIATED UPPER JET STREAK...
FAVORABLE FOR SCT SHRA. MODELS SHOW A BAND OF DEEP LAYER QVECTOR
CONVERGENCE PUSHING ACROSS THE AREA RIGHT WHERE IT WOULD BE EXPECTED
ON THE CYCLONIC SIDE OF THE JET STREAK/SHORTWAVE. SO...SCT SHRA LOOK
LIKE A PRETTY GOOD BET THU...ESPECIALLY OVER THE ERN 2/3RDS OF THE
FCST AREA. WITH 850MB TEMPS FALLING TO AROUND 0C ACROSS CNTRL AND
ERN LAKE SUPERIOR DURING THE TIME OF SYNOPTIC FORCING...THERE WILL
BE SOME LAKE COMPONENT TO THE SHRA...BUT REALLY MORE OF A HYBRID
TYPE COMPONENT AS STILL STRONG DAYTIME HEATING DISRUPTS NORMAL LAKE
EFFECT PROCESSES. END RESULT WILL BE MORE SHRA ACTIVITY INLAND
THAN OVER THE LAKE. OTHERWISE...THU WILL BE A COOL DAY WITH GUSTY
N/NW WINDS AND ABUNDANT CLOUD COVER. TEMPS WILL LIKELY NOT GET OUT
OF THE MID/UPPER 50S ACROSS THE N.
WITH LOSS OF DISRUPTING DAYTIME HEATING...THERE MAY BE AN UPTICK
IN MORE TRADITIONAL LOOKING LAKE EFFECT -SHRA THU NIGHT...MAINLY
OVER THE CNTRL/E UNDER NRLY FLOW WITH 850MB TEMPS FALLING TO -2 OR
-3C. HOWEVER...DEEP LAYER QVECTOR DIVERGENCE/SUBSIDENCE AND A WELL
MIXED BOUNDARY LAYER/INVERTED V LOOK ON FCST SOUNDINGS SUGGEST -SHRA
ACTIVITY PROBABLY WON`T REALLY BE MUCH MORE THAN ISOLD. ATTENTION
THEN TURNS TO FROST POTENTIAL OVER THE W. WITH HIGH PRES STILL
BUILDING TOWARD UPPER MI FROM THE NW...THERE ARE CONCERNS OVER LAKE
EFFECT CLOUD COVER. MODEL GUIDANCE SHOWS DIVERGENT LOW-LEVEL NNE
WINDS OVER THE W WHICH SUGGESTS CLOUDS MAY CLEAR OUT DURING THE
NIGHT. WILL RETAIN IDEA OF CLOUDS AT LEAST PARTIALLY CLEARING OVER
THE FAR W...ALLOWING TEMPS TO FALL INTO THE MID/UPPER 30S WITH
POTENTIAL FOR PATCHY FROST. CLOUDS WILL GRADUALLY CLEAR FROM W TO E
FRI AS SFC HIGH SETTLES INTO UPPER MI. FRI WILL BE COOL WITH HIGHS
MOSTLY IN THE MID TO UPPER 50S.
FRI NIGHT OFFERS A GOOD OPPORTUNITY FOR WIDESPREAD FROST AND ALSO A
POTENTIAL FREEZE IN SOME AREAS. HOWEVER...WITH SFC HIGH QUICKLY
EXITING TO THE SE...RETURN FLOW WILL BE DEVELOPING...PREVENTING
IDEAL RADIATIONAL COOLING THRU THE NIGHT. PRECIPITABLE WATER AROUND
50PCT OF NORMAL AND CLEAR SKIES/CALM WIND AT LEAST INITIALLY WILL
ALLOW FOR A QUICK TEMP DROP FRI EVENING...AND THIS MAY BE ENOUGH TO
RESULT IN WIDESPREAD FROST ACROSS THE INTERIOR. THE BEST CHANCE FOR
FROST AND EVEN SOME FREEZING CONDITIONS WILL BE OVER THE E AND S...
CLOSER TO DEPARTING SFC HIGH WHICH WILL ALLOW A LONGER PERIOD OF
CALM WIND. WILL INCLUDE SOME SUBFREEZING TEMPS INTO THE UPPER 20S IN
THE TRADITIONAL COLD SPOTS OVER THE E.
AS THE HIGH CONTINUES TO MOVE SE SAT AND THE NEXT SHORTWAVE/COLD
FRONT APPROACH FROM THE NW...SW WINDS WILL BRING A GOOD PUSH OF
WARMER AIR INTO THE UPPER LAKES (850MB TEMPS RETURN TO AROUND 10C).
MIXING TO AROUND 850MB YIELDS HIGHS BACK UP TO AROUND NORMAL IN THE
MID 60S TO AROUND 70F UNDER A GOOD DISPLAY OF SUNSHINE...AT LEAST FOR
THE FIRST HALF OF THE DAY.
THE NEXT SHORTWAVE AND ASSOCIATED COLD FRONT WILL MOVE ACROSS THE
AREA SAT NIGHT INTO SUN MORNING. THERE ARE ONLY MINOR TIMING
DIFFERENCES AMONG MEDIUM RANGE GUIDANCE. THE GFS HAS SHOWN VERY GOOD
CONTINUITY OVER THE LAST 4 RUNS...AND THE LATEST RUN IS IN GOOD
AGREEMENT WITH THE GEM/ECMWF. CONSENUS OF GUIDANCE INCLUDING
PREVIOUS GFS RUNS PLACES COLD FRONT BISECTING UPPER MI AT 12Z SUN.
WITH TRACK OF SHORTWAVE PASSING JUST N AND E OF THE FCST AREA...
BETTER POTENTIAL FOR PCPN WILL BE OFF TO THE N AND E OF HERE. ONLY
SCHC/LOW CHC POPS WILL CONTINUE TO BE UTILIZED...MAINLY OVERNIGHT
SAT NIGHT INTO SUN MORNING.
850MB TEMPS DON`T DROP QUITE AS MUCH AS THE PREVIOUS COLD SHOT
THU/FRI...SO POTENTIAL OF LAKE EFFECT CLOUDS/SHRA FOR SUN NIGHT INTO
MON WON`T BE AS GREAT. IN FACT...LAKE EFFECT -SHRA LOOK DOUBTFUL AT
THIS POINT. SFC HIGH SETTLING OVER THE AREA SUN NIGHT WITH DRY AIR
MASS (PRECIPITABLE WATER AROUND 50PCT OF NORMAL) WILL BRING ANOTHER
CHILLY NIGHT WITH FROST AND POSSIBLE FREEZING CONDITIONS IN THE
INTERIOR. FAVORED LOW END OF AVBL GUIDANCE FOR MIN TEMPS SUN NIGHT.
A SUNNY DAY WILL FOLLOW FOR MON. COULD BE SOME FROST CONCERNS AGAIN
MON NIGHT...DEPENDING ON HOW FAST SFC HIGH DEPARTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 141 AM EDT WED SEP 11 2013
EXPECT FOG AT ALL SITES INTO EARLY THIS MORNING...BUT EXACT COVERAGE
AND EXTENT OF FOG REMAINS UNCERTAIN. THERE IS A HIGH POTENTIAL THAT
THE EXISTING CLOUDS OVERHEAD AND TO OUR SW WILL LINGER
OVERHEAD...REDUCING THE POTENTIAL FOR SIGNIFICANT FOG. WILL LIKELY
NEED TO MAKE A FEW ADJUSTMENTS TO THE ONGOING TAFS OVERNIGHT. A COLD
FRONT WILL MOVE THROUGH THIS AFTERNOON/EVENING...AND SOME CONVECTION
IS EXPECTED ALONG THE FRONT. HAVE THE HIGHEST CONFIDENCE OF
CONVECTION AT SAW...SO INCLUDED VCSH THERE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 PM EDT TUE SEP 10 2013
PATCHY TO AREAS OF FOG SHOULD SLOWLY DISSIPATE INTO THIS EVENING AS
DRIER AIR WORKS IN FROM THE NORTH. WEAK HIGH PRESSURE THIS EVENING
WILL BE REPLACED BY A BROAD TROUGH THAT WILL BE EXTENDING SOUTHWARD
FROM NORTHERN ONTARIO LATE TONIGHT THROUGH EARLY WEDNESDAY EVENING.
A LARGE HIGH PRESSURE ENCOMPASSING MUCH OF S CENTRAL CANADA AND THE
N PLAINS WEDNESDAY NIGHT WILL SLOWLY DRIFT ACROSS THE UPPER GREAT
LAKES FRIDAY INTO SATURDAY...BEFORE EXITING TO THE LOWER GREAT LAKES
AND THE E COAST FOR THE LATTER HALF OF THE WEEKEND. THE STRONGEST
WINDS OVER LAKE SUPERIOR...OUTSIDE OF THUNDERSTORMS...WILL BE LATE
WEDNESDAY NIGHT THROUGH EARLY FRIDAY MORNING...WITH N GUSTS OF
20-30KTS CENTERED ACROSS MAINLY CENTRAL AND E LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...ROLFSON
AVIATION...JT/KF
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
144 AM EDT WED SEP 11 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 408 PM EDT TUE SEP 10 2013
PER WATER VAPOR IMAGERY AND RUC ANALYSIS...A SHORTWAVE MOVING ACROSS
NRN ONTARIO AND LAKE SUPERIOR THIS AFTERNOON COMBINED WITH UPR DIV
IN RIGHT ENTRANCE REGION OF ASSOC 100+ KT 3H JET HAVE HELPED SUSTAIN
A COUPLE DIFFERENT BATCHES OF SHRA WHICH HAVE MOVED OVER THE WEST
HALF OF UPPER MI THIS AFTERNOON. UPSLOPE FOG WHICH PLAGUED THE
KEWEENAW INTO THE EARLY AFTERNOON HOURS LOOKS LIKE IT HAS FINALLY
LIFTED PER SFC OBS AND WEB CAMS BUT STRATUS CLOUDS STILL REMAIN. AT
THE SFC...A COUPLE OF SFC TROUGHS EXTEND FM LOW PRES CENTERED NE OF
LAKE SUPERIOR...ONE TROUGH EXTENDS INTO ERN AND SCNTRL UPR MI WHILE
ANOTHER IS STILL SITUATED OVER FAR NRN LAKE SUPERIOR AND ONTARIO.
TONIGHT...EXPECT AREA OF SHOWERS NOW EXTENDING FM IRON COUNTY INTO
WRN MQT COUNTY TO MOVE SLOWLY EAST OVER THE NEXT COUPLE OF HOURS AND
THEN GRADUALLY DISSIPATE THIS EVENING AS 700-650 MB FGEN SLOWLY
WEAKENS. THERE IS A CONCERN THAT A STRONG TO POSSIBLY SVR STORM
COULD FORM OVER THE ERN HALF OF UPPER MI IN THE NEXT FEW HOURS.
PARTIAL SUNSHINE HAS ALLOWED MLCAPES TO BUILD UP TO AROUND 2000
J/KG. THIS ALONG WITH EFFECTIVE SHEAR OF 50-60 KT AND ENHANCED
CONVERGENCE ALONG SFC TROUGH COULD TRIGGER STORMS OVER ERN UPPER MI
LATE AFTERNOON INTO EARLY EVENING. THIS WILL NEED TO BE CLOSELY
MONITORED ON THE EVENING SHIFT.
THE OTHER CONCERN TONIGHT IS THE POTENTIAL FOR MORE FOG TO FORM LATE
EVENING INTO OVERNIGHT HRS AS TEMPS RADIATE THROUGH UPPER 50S/LOWER
60S DEWPOINTS UNDER LIGHT WINDS AND PARTIAL CLEARING. HAVE EXPANDED
MENTION OF PATCHY TO AREAS OF FOG ACROSS THE CWA AND WOULD NOT BE
SURPRISED TO SEE SOME LOCALLY DENSE FOG AT SOME LOCATIONS.
WEDNESDAY...ANOTHER SHORTWAVE NOW DROPPING DOWN FROM NRN
SASKATCHEWAN/NRN MANITOBA WILL HELP PUSH FRONTAL BOUNDARY INTO THE
AREA. SCNTRL AND ERN UPR MI WILL AGAIN HAVE BEST CHC OF AFTERNOON
SHRA/TSRA AS MLCAPES ARE FCST BY MODELS TO INCREASE TO 500-1000
J/KG. WILL INCLUDE HIGHER CHC 40 PCT POPS OVER THIS AREA. WITH WEAK
DOWNSLOPE WRLY FLOW INTO THE BAY OF GREEN BAY...EXPECT THE WARMEST
HIGH TEMPS (LOWER TO MID 80S) OVER MNM COUNTY. ELSEWHERE MAX TEMPS
WILL GENERALLY BE IN THE 70S.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 408 PM EDT TUE SEP 10 2013
COLD FRONT WILL BE DEPARTING THE CWA AT THE START OF THE LONG TERM
PERIOD...WHILE A POTENT SHORTWAVE DROPS SOUTHEAST ACROSS THE UPPER
GREAT LAKES REGION. THE MAIN PRECIPITATION WITH THE COLD
FRONT WILL BE SLIDING SOUTHEAST OVER THE EASTERN CWA TO START THE
PERIOD. BEHIND THIS...THERE SHOULD BE A QUICK BREAK TO THE
PRECIPITATION BEFORE COLDER AIR AND ABUNDANT LOW LEVEL MOISTURE
SURGES SOUTH ACROSS LAKE SUPERIOR LATE WEDNESDAY NIGHT INTO THURSDAY
ON THE EAST SIDE OF THE HIGH MOVING INTO THE NORTHERN PLAINS.
THUS...WOULD EXPECT A PERIOD OF PARTLY CLOUDY SKIES FOR A TIME
WEDNESDAY NIGHT BEFORE THE 850MB TEMPS FALL TO 0C BETWEEN 18Z
THURSDAY TO 00Z FRIDAY. SINCE LAKE SUPERIOR TEMPS ARE AROUND
12-16C...THIS INCREASING COLD AIR WILL PUSH DELTA T VALUES TOWARDS
FAVORABLE LAKE EFFECT RAIN SHOWERS AND CLOUDS. THE INVERSION HEIGHT
IS RIGHT AROUND 825MB OR 4.5KFT...SO THAT WILL LIMIT THE CLOUD DEPTH
FOR STRONGER SHOWERS...BUT STILL THINK THERE WILL BE ENOUGH AROUND
FOR ISOLATED/SCATTERED MENTION IN THE FAVORED NORTH-NORTHWEST WIND
LOCATIONS. WILL RAMP UP THE POPS THROUGH THE DAY AS THE COLDEST AIR
AND BEST MOISTURE ARRIVES IN THE AFTERNOON AND EARLY EVENING.
IT IS STARTING TO LOOK LIKE THE CLOUDS WILL LINGER LONGER ON
THURSDAY NIGHT...WHICH BRINGS THE LOW FORECAST AND FROST
POTENTIAL INTO QUESTION. OPTED TO TREND TEMPS AND CLOUDS UP SOME
THROUGH THE NIGHT. THE BEST OPPORTUNITY FOR BREAKS IN THE CLOUDS
LOOKS TO BE OVER THE VERY FAR WEST (GOGEBIC/ONTONAGON COUNTIES) AND
WILL KEEP THE COLDEST TEMPERATURES THERE. THIS LONGER LASTING
MOISTURE CALLS FOR THE CLOUDS TO HANG ON INTO AT LEAST FRIDAY
MORNING AND HAVE TRENDED THE SKY FORECAST UP SIGNIFICANTLY FOR THAT
TIME. ALSO DELAYED THE END OF THE SHOWER CHANCES INTO THE MORNING
FOR LOCATIONS FROM MARQUETTE EASTWARD. ALL OF THE MODELS ARE SHOWING
THE MOISTURE DIMINISHING FROM WEST TO EAST DURING THE AFTERNOON AS
THE HIGH MOVES OVER THE CWA. HIGHS ON FRIDAY WILL BE FAIRLY
COOL...WITH HIGHS IN THE MID AND UPPER 50S.
THIS HIGH WILL LEAD TO A VERY CHILLY NIGHT ON FRIDAY NIGHT. SINCE
WINDS WILL BECOME CALM...SKIES WILL BE CLEAR...AND PWATS ARE AROUND
40-45 PERCENT OF NORMAL...EXPECT A GOOD RADIATIONAL COOLING NIGHT.
FORECAST HAS BEEN HITTING THE POTENTIAL FOR FROST ON FRIDAY NIGHT
AND THAT CONTINUES TO SEEM REASONABLE. DID TREND LOWS DOWN A COUPLE
DEGREES OVER THE INTERIOR LOCATIONS AND IT APPEARS LIKE THERE WILL
BE A DECENT OPPORTUNITY FOR FROST IN THAT AREA WITH LOWS IN THE MID
30S. SOME OF THE TRADITIONAL COLD SPOTS OVER THE CENTRAL/EAST MAY
EVEN FALL BELOW FREEZING FOR AWHILE.
THE HIGH WILL SHIFT SOUTHEAST ON SATURDAY AND INCREASING SOUTHERLY
FLOW WILL PUSH TEMPERATURES BACK TOWARDS NORMAL AND AROUND . WITH
10 DEGREES WARMER THAN FRIDAY. THE AREA UNDER A RIDGE ALOFT...EXPECT
A MOSTLY SUNNY DAY ON SATURDAY.
THE NEXT SHORTWAVE AND ASSOCIATED COLD FRONT WILL MOVE ACROSS THE
AREA SATURDAY NIGHT INTO SUNDAY MORNING. THE 12Z MODEL RUNS OF
THE ECMWF/GFS/GEM HAVE COME INTO DECENT AGREEMENT WITH THE
TRACK OF THE SHORTWAVE BRUSHING THE UPPER GREAT LAKES REGION
AND THUS THE TIMING/LOCATION OF THE FRONT AND PRECIPITATION.
SINCE THE MAIN FORCING/MOISTURE LOOKS TO TRACK ACROSS
NORTHEAST LAKE SUPERIOR...HAVE TRENDED POPS DOWN SOMEWHAT AND
TOWARDS SLIGHT CHANCE AND LOW CHANCE POPS. COLD AIR
WILL ONLY BRUSH THE AREA BEHIND THIS FRONT...SO THINK THE POTENTIAL
FOR LAKE ENHANCED CLOUDS/SHOWERS FOR SUNDAY NIGHT INTO MONDAY LOOKS
TO BE LESS LIKELY THAN SHOWN ON YESTERDAY/S RUNS. HIGH PRESSURE
BUILDS IN FOR MONDAY AND MONDAY NIGHT AND SHOULD LEAD TO DRY WEATHER
FOR THE START OF THE WORK WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 141 AM EDT WED SEP 11 2013
EXPECT FOG AT ALL SITES INTO EARLY THIS MORNING...BUT EXACT COVERAGE
AND EXTENT OF FOG REMAINS UNCERTAIN. THERE IS A HIGH POTENTIAL THAT
THE EXISTING CLOUDS OVERHEAD AND TO OUR SW WILL LINGER
OVERHEAD...REDUCING THE POTENTIAL FOR SIGNIFICANT FOG. WILL LIKELY
NEED TO MAKE A FEW ADJUSTMENTS TO THE ONGOING TAFS OVERNIGHT. A COLD
FRONT WILL MOVE THROUGH THIS AFTERNOON/EVENING...AND SOME CONVECTION
IS EXPECTED ALONG THE FRONT. HAVE THE HIGHEST CONFIDENCE OF
CONVECTION AT SAW...SO INCLUDED VCSH THERE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 408 PM EDT TUE SEP 10 2013
PATCHY TO AREAS OF FOG SHOULD SLOWLY DISSIPATE INTO THIS EVENING AS
DRIER AIR WORKS IN FROM THE NORTH. WEAK HIGH PRESSURE THIS EVENING
WILL BE REPLACED BY A BROAD TROUGH THAT WILL BE EXTENDING SOUTHWARD
FROM NORTHERN ONTARIO LATE TONIGHT THROUGH EARLY WEDNESDAY EVENING.
A LARGE HIGH PRESSURE ENCOMPASSING MUCH OF S CENTRAL CANADA AND THE
N PLAINS WEDNESDAY NIGHT WILL SLOWLY DRIFT ACROSS THE UPPER GREAT
LAKES FRIDAY INTO SATURDAY...BEFORE EXITING TO THE LOWER GREAT LAKES
AND THE E COAST FOR THE LATTER HALF OF THE WEEKEND. THE STRONGEST
WINDS OVER LAKE SUPERIOR...OUTSIDE OF THUNDERSTORMS...WILL BE LATE
WEDNESDAY NIGHT THROUGH EARLY FRIDAY MORNING...WITH N GUSTS OF
20-30KTS CENTERED ACROSS MAINLY CENTRAL AND E LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...JT/KF
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS DULUTH MN
934 PM CDT THU SEP 12 2013
.UPDATE...
ISSUED AT 932 PM CDT THU SEP 12 2013
HAVE ADDED PATCHY FROST TO ALL REMAINING ZONES AND GRIDS FOR THE
REST OF THE NIGHT. THE FREEZE WARNING AREA STILL LOOKS GOOD...AS
WELL AS THE FROST ADVISORY AREA. CONSIDERED EXPANDING THE FROST
ADVISORY A BIT BUT DECIDED TO HOLD OFF AND ADD PATCHY FROST
MENTION TO THE REMAINDER OF THE NORTHLAND. CLOUDS HAVE CLEARED
NICELY ACROSS THE REGION...WITH CLEAR TO MOSTLY CLEAR SKIES FOR
THE REST OF THE NIGHT.
UPDATE ISSUED AT 658 PM CDT THU SEP 12 2013
.AVIATION.../00Z TAF ISSUANCE/
VFR CONDITIONS ARE EXPECTED ACROSS THE NORTHLAND THROUGHOUT THE
TAF PERIOD. LOCALIZED MVFR/IFR FOG WILL BE POSSIBLE...ESPECIALLY
AT KHYR.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 322 PM CDT THU SEP 12 2013
AT 315PM/2015Z...SURFACE HIGH PRESSURE WAS CENTERED OVER THE
NORTHERN PLAINS...SOMEWHERE NEAR THE NORTH DAKOTA AND MANITOBA
BORDER. MUCH OF THE UPPER MIDWEST...INCLUDING THE NORTHLAND...HAD
COOL NORTHERLY FLOW WHICH WAS RESULTING IN PARTLY TO MOSTLY CLOUDY
SKIES ACROSS THE REGION. TEMPERATURES ACROSS THE NORTHLAND RANGED
FROM THE LOW 50S OVER THE TIP OF THE ARROWHEAD TO THE LOW TO MID
60S ACROSS MUCH OF THE REST OF THE NORTHLAND. THE BRAINERD LAKES
REGION HAD MID 60S TO LOW 70S. DEW POINT TEMPERATURES RANGED FROM
THE UPPER 30S OVER THE TIP OF THE ARROWHEAD...TO THE LOW TO MID
40S ACROSS THE REST OF THE NORTHLAND.
TONIGHT...THE HIGH PRESSURE IN THE NORTHERN PLAINS WILL MOVE OVER
THE NORTHLAND. THIS SHOULD RESULT IN AN OVERALL TREND IN CLEARING
SKIES AND DIMINISHING WIND WHICH WILL BE A RECIPE FOR A COLD NIGHT
ACROSS THE NORTHLAND. I BELIEVE OVERALL THE MODEL GUIDANCE IS
UNDERESTIMATING THE DEGREE OF RADIATIONAL COOLING TONIGHT...SO I
LEANED AND FORECASTED SLIGHTLY BELOW THE COLDEST GUIDANCE. FAR
NORTHERN MINNESOTA STILL LOOKS LIKE IT WILL BE THE COLDEST PART OF
THE FORECAST AREA AND WILL VERY LIKELY PLUMMET TO NEAR AND SUB
FREEZING TEMPERATURES. I MAINTAINED A FREEZE WARNING FOR THE IRON
RANGE AND INTERIOR ARROWHEAD...AS WELL AS THE FROST ADVISORY FOR
KOOCHICHING COUNTY...BUT ADDED NORTHERN ITASCA COUNTY TO THE FROST
ADVISORY. I STILL HAVE A LITTLE CONCERN ABOUT LINGERING CLOUD COVER
TONIGHT AND HOW IT MAY PREVENT TEMPERATURES FROM GETTING AS COLD
AS FORECAST. HOWEVER...LATEST HRRR MODEL RUNS ARE SHOWING PRETTY
GOOD CLEARING TONIGHT. THERE MIGHT BE A LITTLE LINGERING CLOUD
COVER HERE AND THERE...SUCH AS THE TIP OF THE ARROWHEAD...BUT I
THINK IT WILL HAVE LITTLE IMPACT TO THE FORECAST. I ADDED PATCHY
FROST TO OTHER PARTS OF THE NORTHLAND...SUCH AS PARTS OF THE SW
AND SE FORECAST AREA...BUT HELD OFF ON EXPANDING FROST ADVISORIES
TO THOSE AREAS SINCE THE TEMPERATURES LOOK TO BE BORDERLINE FOR
FROST. ALSO...THERE MAY BE LINGERING CLOUD COVER OVER PARTS OF NW
WISCONSIN DUE TO THE NORTH WINDS OFF LAKE SUPERIOR. THE EVENING
SHIFT WILL NEED TO MONITOR TRENDS AND RECONSIDER ADDING OTHER
PARTS OF THE FORECAST AREA TO THE FROST ADVISORY.
FRIDAY...THE HIGH PRESSURE WILL BEGIN TO SHIFT TOWARDS SOUTHERN
MINNESOTA AND IOWA. LIGHT SSW WINDS WILL DEVELOP ACROSS NE
MINNESOTA. SUNNY SKIES ARE EXPECTED WITH HIGHS IN THE MID TO UPPER
60S ACROSS MOST OF THE NORTHLAND...SAVE THE TIP OF THE ARROWHEAD
WHICH WILL SEE UPPER 50S TO LOW 60S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 322 PM CDT THU SEP 12 2013
FRIDAY NIGHT THE SURFACE RIDGE AND COLD TEMPERATURES SLIDE OFF TO
THE SOUTHEAST AND ALLOW SOUTHWEST RETURN FLOW TO BEGIN OVER THE
AREA. THIS CONTINUES...WITH GRADUALLY WARMING TEMPERATURES INTO
SATURDAY. ON SATURDAY A STRONG SHORTWAVE AND COLD FRONT PUSHES
INTO THE AREA FROM THE NORTHWEST. AT THE SAME TIME...A CUT OFF
UPPER LOW THAT HAS BEEN SITTING OVER THE SOUTHWEST CONUS THE LAST
FEW DAYS FINALLY GETS CAUGHT UP IN THE NORTHERN STREAM...AND
EJECTS OUT OVER THE PLAINS. THE RESULTING SYSTEM PULLS SOME
MOISTURE UP INTO OUR AREA...WITH A WARM FRONT THAT GETS AS FAR
NORTH AS SOUTH DAKOTA AND SOUTHERN MN SATURDAY NIGHT. THIS SHOULD
PRODUCE SOME SHOWERS AND ISOLATED THUNDER ACROSS OUR SOUTH
BEGINNING LATE SATURDAY AFTERNOON AND NIGHT...WITH SCATTERED
SHOWERS AND THUNDERSTORMS ALONG THE COLD FRONT SATURDAY NIGHT AND
EARLY SUNDAY. TEMPERATURES REMAIN MILD SOUTH OF THE FRONT...BUT
SATURDAY NIGHT MINS WILL RANGE FROM THE LOW TO MID 50S SOUTH...TO
THE MID 40S NORTH OF THE COLD FRONT.
SUNDAY TO BE MUCH COLDER AND DRIER WITH A SURFACE RIDGE BUILDING
ACROSS THE AREA...AND UPPER LEVEL RIDGING BUILDING AS WELL. SUNDAY
HIGHS ONLY RANGING FROM AROUND 60 NORTH TO THE MID 60S SOUTH.
SUNDAY NIGHT MINS COULD ONCE AGAIN BE COLD ENOUGH FOR
FROST...WITH MINS IN THE 30S TO AROUND 40.
THE UPPER LEVEL RIDGE SHIFTS OFF TO THE EAST BY EARLY IN THE
WEEK...ALLOWING A MORE SOUTHWEST FLOW SYSTEM TO ENTER THE AREA
MONDAY AND TUESDAY. A WAVE OF WARM AIR ADVECTION AND ISENTROPIC
LIFT MOVES INTO THE AREA BEGINNING MONDAY NIGHT...BRINGING A
CHANCE OF PRECIPITATION FOR MONDAY NIGHT THROUGH TUESDAY AND EVEN
EARLY WEDNESDAY. IT IS HARD TO SPECIFY ANY DRY PERIODS WITH THE
WARM MOIST AIR ADVECTION GOING ON ALOFT AND A WARM FRONT IN THE
VICINITY...THOUGH I AM SURE THERE WILL BE SOME. TEMPERATURES WILL
GRADUALLY WARM THROUGH WEDNESDAY. BY THURSDAY...THE SURFACE LOW
FINALLY BEGINS TO TAKE SHAPE IN THE PLAINS AND ADVANCES ACROSS
MINNESOTA DURING THE DAY. TRACK AND TIMING ARE STILL UNCERTAIN
WITH SOME SIGNIFICANT DIFFERENCES IN THE MODELS...BUT
PRECIPITATION CHANCES INCREASE AGAIN FOR THURSDAY WITH THE LOW IN
THE STATE AND PLENTY OF HEAT AND MOISTURE IN THE AREA.
&&
.AVIATION.../00Z TAF ISSUANCE/
VFR CONDITIONS ARE EXPECTED ACROSS THE NORTHLAND THROUGHOUT THE
TAF PERIOD. LOCALIZED MVFR/IFR FOG WILL BE POSSIBLE...ESPECIALLY
AT KHYR.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 40 65 48 71 / 0 0 0 20
INL 34 69 49 74 / 0 0 0 30
BRD 38 70 49 71 / 0 0 0 30
HYR 35 67 43 71 / 0 0 0 10
ASX 39 65 47 72 / 10 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...FREEZE WARNING FROM 1 AM TO 8 AM CDT FRIDAY FOR MNZ011-012-019.
FROST ADVISORY FROM 1 AM TO 8 AM CDT FRIDAY FOR MNZ010-018.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...DAP
SHORT TERM...GROCHOCINSKI
LONG TERM...LE
AVIATION...LE
AREA FORECAST DISCUSSION
NWS DULUTH MN
659 PM CDT THU SEP 12 2013
.UPDATE...
ISSUED AT 658 PM CDT THU SEP 12 2013
.AVIATION.../00Z TAF ISSUANCE/
VFR CONDITIONS ARE EXPECTED ACROSS THE NORTHLAND THROUGHOUT THE
TAF PERIOD. LOCALIZED MVFR/IFR FOG WILL BE POSSIBLE...ESPECIALLY
AT KHYR.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 322 PM CDT THU SEP 12 2013
AT 315PM/2015Z...SURFACE HIGH PRESSURE WAS CENTERED OVER THE
NORTHERN PLAINS...SOMEWHERE NEAR THE NORTH DAKOTA AND MANITOBA
BORDER. MUCH OF THE UPPER MIDWEST...INCLUDING THE NORTHLAND...HAD
COOL NORTHERLY FLOW WHICH WAS RESULTING IN PARTLY TO MOSTLY CLOUDY
SKIES ACROSS THE REGION. TEMPERATURES ACROSS THE NORTHLAND RANGED
FROM THE LOW 50S OVER THE TIP OF THE ARROWHEAD TO THE LOW TO MID
60S ACROSS MUCH OF THE REST OF THE NORTHLAND. THE BRAINERD LAKES
REGION HAD MID 60S TO LOW 70S. DEW POINT TEMPERATURES RANGED FROM
THE UPPER 30S OVER THE TIP OF THE ARROWHEAD...TO THE LOW TO MID
40S ACROSS THE REST OF THE NORTHLAND.
TONIGHT...THE HIGH PRESSURE IN THE NORTHERN PLAINS WILL MOVE OVER
THE NORTHLAND. THIS SHOULD RESULT IN AN OVERALL TREND IN CLEARING
SKIES AND DIMINISHING WIND WHICH WILL BE A RECIPE FOR A COLD NIGHT
ACROSS THE NORTHLAND. I BELIEVE OVERALL THE MODEL GUIDANCE IS
UNDERESTIMATING THE DEGREE OF RADIATIONAL COOLING TONIGHT...SO I
LEANED AND FORECASTED SLIGHTLY BELOW THE COLDEST GUIDANCE. FAR
NORTHERN MINNESOTA STILL LOOKS LIKE IT WILL BE THE COLDEST PART OF
THE FORECAST AREA AND WILL VERY LIKELY PLUMMET TO NEAR AND SUB
FREEZING TEMPERATURES. I MAINTAINED A FREEZE WARNING FOR THE IRON
RANGE AND INTERIOR ARROWHEAD...AS WELL AS THE FROST ADVISORY FOR
KOOCHICHING COUNTY...BUT ADDED NORTHERN ITASCA COUNTY TO THE FROST
ADVISORY. I STILL HAVE A LITTLE CONCERN ABOUT LINGERING CLOUD COVER
TONIGHT AND HOW IT MAY PREVENT TEMPERATURES FROM GETTING AS COLD
AS FORECAST. HOWEVER...LATEST HRRR MODEL RUNS ARE SHOWING PRETTY
GOOD CLEARING TONIGHT. THERE MIGHT BE A LITTLE LINGERING CLOUD
COVER HERE AND THERE...SUCH AS THE TIP OF THE ARROWHEAD...BUT I
THINK IT WILL HAVE LITTLE IMPACT TO THE FORECAST. I ADDED PATCHY
FROST TO OTHER PARTS OF THE NORTHLAND...SUCH AS PARTS OF THE SW
AND SE FORECAST AREA...BUT HELD OFF ON EXPANDING FROST ADVISORIES
TO THOSE AREAS SINCE THE TEMPERATURES LOOK TO BE BORDERLINE FOR
FROST. ALSO...THERE MAY BE LINGERING CLOUD COVER OVER PARTS OF NW
WISCONSIN DUE TO THE NORTH WINDS OFF LAKE SUPERIOR. THE EVENING
SHIFT WILL NEED TO MONITOR TRENDS AND RECONSIDER ADDING OTHER
PARTS OF THE FORECAST AREA TO THE FROST ADVISORY.
FRIDAY...THE HIGH PRESSURE WILL BEGIN TO SHIFT TOWARDS SOUTHERN
MINNESOTA AND IOWA. LIGHT SSW WINDS WILL DEVELOP ACROSS NE
MINNESOTA. SUNNY SKIES ARE EXPECTED WITH HIGHS IN THE MID TO UPPER
60S ACROSS MOST OF THE NORTHLAND...SAVE THE TIP OF THE ARROWHEAD
WHICH WILL SEE UPPER 50S TO LOW 60S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 322 PM CDT THU SEP 12 2013
FRIDAY NIGHT THE SURFACE RIDGE AND COLD TEMPERATURES SLIDE OFF TO
THE SOUTHEAST AND ALLOW SOUTHWEST RETURN FLOW TO BEGIN OVER THE
AREA. THIS CONTINUES...WITH GRADUALLY WARMING TEMPERATURES INTO
SATURDAY. ON SATURDAY A STRONG SHORTWAVE AND COLD FRONT PUSHES
INTO THE AREA FROM THE NORTHWEST. AT THE SAME TIME...A CUT OFF
UPPER LOW THAT HAS BEEN SITTING OVER THE SOUTHWEST CONUS THE LAST
FEW DAYS FINALLY GETS CAUGHT UP IN THE NORTHERN STREAM...AND
EJECTS OUT OVER THE PLAINS. THE RESULTING SYSTEM PULLS SOME
MOISTURE UP INTO OUR AREA...WITH A WARM FRONT THAT GETS AS FAR
NORTH AS SOUTH DAKOTA AND SOUTHERN MN SATURDAY NIGHT. THIS SHOULD
PRODUCE SOME SHOWERS AND ISOLATED THUNDER ACROSS OUR SOUTH
BEGINNING LATE SATURDAY AFTERNOON AND NIGHT...WITH SCATTERED
SHOWERS AND THUNDERSTORMS ALONG THE COLD FRONT SATURDAY NIGHT AND
EARLY SUNDAY. TEMPERATURES REMAIN MILD SOUTH OF THE FRONT...BUT
SATURDAY NIGHT MINS WILL RANGE FROM THE LOW TO MID 50S SOUTH...TO
THE MID 40S NORTH OF THE COLD FRONT.
SUNDAY TO BE MUCH COLDER AND DRIER WITH A SURFACE RIDGE BUILDING
ACROSS THE AREA...AND UPPER LEVEL RIDGING BUILDING AS WELL. SUNDAY
HIGHS ONLY RANGING FROM AROUND 60 NORTH TO THE MID 60S SOUTH.
SUNDAY NIGHT MINS COULD ONCE AGAIN BE COLD ENOUGH FOR
FROST...WITH MINS IN THE 30S TO AROUND 40.
THE UPPER LEVEL RIDGE SHIFTS OFF TO THE EAST BY EARLY IN THE
WEEK...ALLOWING A MORE SOUTHWEST FLOW SYSTEM TO ENTER THE AREA
MONDAY AND TUESDAY. A WAVE OF WARM AIR ADVECTION AND ISENTROPIC
LIFT MOVES INTO THE AREA BEGINNING MONDAY NIGHT...BRINGING A
CHANCE OF PRECIPITATION FOR MONDAY NIGHT THROUGH TUESDAY AND EVEN
EARLY WEDNESDAY. IT IS HARD TO SPECIFY ANY DRY PERIODS WITH THE
WARM MOIST AIR ADVECTION GOING ON ALOFT AND A WARM FRONT IN THE
VICINITY...THOUGH I AM SURE THERE WILL BE SOME. TEMPERATURES WILL
GRADUALLY WARM THROUGH WEDNESDAY. BY THURSDAY...THE SURFACE LOW
FINALLY BEGINS TO TAKE SHAPE IN THE PLAINS AND ADVANCES ACROSS
MINNESOTA DURING THE DAY. TRACK AND TIMING ARE STILL UNCERTAIN
WITH SOME SIGNIFICANT DIFFERENCES IN THE MODELS...BUT
PRECIPITATION CHANCES INCREASE AGAIN FOR THURSDAY WITH THE LOW IN
THE STATE AND PLENTY OF HEAT AND MOISTURE IN THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM CDT THU SEP 12 2013
WIDESPREAD CUMULUS FIELD OVER MOST OF THE TERMINALS...WITH MOST
CLOUD BASES AOA 3KFT. KHYR 2.5-3KFT...BUT SHOULD CONTINUE TO
RISE IN THE NEXT COUPLE HOURS. THIS CUMULUS FIELD MAY GO BROKEN AT
TIMES THROUGH THE REMAINDER OF THE AFTERNOON...BUT CIGS WILL BE
VFR. NORTHWEST WINDS AROUND 12KTS WITH SOME GUSTS TO
20KTS...DEPENDING ON LOCATION. TONIGHT CUMULUS FIELD AND WINDS TO
DIMINISH...AND EXPECT SKY TO CLEAR WITH WINDS LESS THAN 10KTS BY
01Z THIS EVENING. SOME STRATUS AROUND 2-3KFT MAY AFFECT MN
ARROWHEAD...BUT SHOULD NOT AFFECT TERMINALS. FOG POSSIBLE AT KINL
AND KHYR...BUT ONLY HAVE CONFIDENCE AT KHYR AND HAVE INCLUDED A
TEMPO GROUP FOR 1SM BR. 14-18Z FRIDAY WINDS TO TURN
SOUTHWEST...BUT REMAIN LESS THAN 10KTS. SOME VFR CUMULUS ALSO
EXPECTED TO DEVELOP IN THIS TIME RANGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 40 65 48 71 / 0 0 0 20
INL 34 69 49 74 / 0 0 0 30
BRD 38 70 49 71 / 0 0 0 30
HYR 35 67 43 71 / 0 0 0 10
ASX 39 65 47 72 / 10 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...FREEZE WARNING FROM 1 AM TO 8 AM CDT FRIDAY FOR MNZ011-012-019.
FROST ADVISORY FROM 1 AM TO 8 AM CDT FRIDAY FOR MNZ010-018.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...DAP
SHORT TERM...GROCHOCINSKI
LONG TERM...LE
AVIATION...LE
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
336 PM CDT Wed Sep 11 2013
.SHORT TERM: (Tonight through Saturday)
Issued at 334 PM CDT Wed Sep 11 2013
Primary concern for tonight will be convection developing
along/ahead of the cold front now moving southeast through Iowa.
Already seeing scattered storms over north central Missouri. SPC
meso-analysis is showing about 1000 j/kg surface CAPE up there well
ahead of the front, with as much as 2500 j/kg along the front in
Iowa. Another axis of higher cape can be found south of the STL
metro area across the eastern Ozarks. Isolated storms have
developed in this region as well. Expect the storms over the Ozarks
to diminish fairly quickly during the early evening with the loss of
daytime heating, however isolated to scattered storms should
continue across northern Missouri into west central Illinois through
much of the night as the front drifts into the area. HRRR and 4km
NCEP WRF models depict this well, and the operational NAM, GFS, and
RUC models also print out light qpf along the front as it tracks
southeast. BUFKIT soundings never really indicate much CAPE in our
area tonight, with the highest readings from the NAM at around 1000
j/kg, so would not really expect any storms that affect the area to
get too strong.
Models have the initial wind shift (perhaps driven by outflow) down
to near the I-70 corridor by 12z Thursday. The truly cooler air
lags behind up across the MO/IA border. However, the shortwave
currently over Manitoba dives down overnight and into the
Mid-Mississippi Valley by around 18z Thursday. This will sharpen up
the longwave pattern and drive the cold front south through the CWFA
by Thursday evening. Scattered showers and thunderstorms will
continue to be possible until the front comes through and
cooler/drier air settles across the region.
Temperatures will be a little cooler on Thursday, but still thinking
mid to upper 80s ahead of the front. A true taste of Fall is
expected to close out the week and start the weekend as a Canadian
high pressure system settles into the Ohio Valley. Daytime highs
will be in the low to mid 70s and overnight lows will dip into the
low to mid 50s Friday morning, and mid 40s to low 50s Saturday
morning.
Carney
.LONG TERM: (Sunday through Next Wednesday)
Issued at 334 PM CDT Wed Sep 11 2013
Sunday through Wednesday
The Canadian high will continue to move east across the Mid-Atlantic
states Sunday. Return flow will ramp up bringing warmer and more
humid air back to the region. Medium range models develop a decent
low level baroclinic zone across northern Missouri into central
Illinois. Normally, I`d be more bullish with pops in vicinity of a
baroclinic zone with southwest flow impinging on it; however with
severe drought conditions once again being reported across much of
northern Missouri, am playing it conservatively for now with only
chance and slight chance pops through mid week. Temperatures will
be near or a few degrees above normal.
Carney
&&
.AVIATION: (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1201 PM CDT Wed Sep 11 2013
Latest surface analysis shows a slow moving cold front stretching
from western Lake Superior through western Wisconsin and northern
Iowa into southeast Nebraska. Scattered showers and isolated
thunderstorms continue ahead of the front across extreme northwest
Missouri, southern Iowa, and northern Illinois.
Front will slowly make its way south across the forecast area over
the next 24 hours, bringing a wind shift to the northwest and a
chance of showers and thunderstorms. The best chance of
measurable rainfall remains across northeast Missouri and west
central Illinois tonight. Otherwise, model guidance portrays a
lull in activity as the front progresses through the center of the
forecast area (I-70 corridor) late tonight and Thursday morning
before refiring further south Thursday afternoon.
Specifics for KSTL:
VFR conditions expected with the cold front moving across the
terminal complex around 09Z. Wind will shift to the northwest.
CVKING
&&
.CLIMATE:
Issued at 342 AM CDT Wed Sep 11 2013
RECORD HIGHS:
SEPT 11
STL 97/1938
COU 100/1936
UIN 99/1936
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
435 PM CDT WED SEP 11 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 435 PM CDT WED SEP 11 2013
PRIMARY CONCERNS DURING THE NEXT 24 HOURS INCLUDE THE
COVERAGE/INTENSITY OF THUNDERSTORMS MAINLY THROUGH TONIGHT...WITH
STORM CHANCES EXPECTED TO BE ON THE WANE ACROSS ALL BUT MAINLY THE
SOUTHWEST 1/4 OF THE CWA DURING THE DAY THURSDAY. ALTHOUGH A
ROGUE...MARGINALLY SEVERE STORM CANNOT BE RULED OUT SOUTH OF
HIGHWAY 6 INTO NORTH CENTRAL KANSAS INTO THIS EVENING...THE VAST
MAJORITY OF STORMS SHOULD REMAIN SUB-SEVERE...WITH MAIN THREATS OF
50-ISH MPH WINDS AND SMALL HAIL POSSIBLY UP TO 50 MPH.
TEMP-WISE...NUDGED UP HIGHS A FEW DEGREES FOR TOMORROW IN MOST
AREAS WITH EXPECTATION OF OVERALL MORE SUN ESPECIALLY
CENTRAL/NORTHEAST AREAS AND A DRIER AIRMASS.
20Z OBJECTIVE SURFACE ANALYSIS HIGHLIGHTS A FAIRLY WELL-DEFINED WEAK
COLD FRONT/QUASI-STATIONARY FRONT DRAPED JUST SOUTH OF THE NEB/KS
LINE...EFFECTIVELY SEPARATING A LIGHT SOUTH-SOUTHEAST BREEZE FROM
A PREVAILING EAST-NORTHEAST BREEZE AROUND 10 MPH ACROSS MOST NEB
ZONES. ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA
HIGHLIGHTS WEST-SOUTHWEST FLOW AT 500/700 MILLIBARS OVER THE LOCAL
AREA...AS THE CENTRAL PLAINS LIES IN BETWEEN A RIDGE AXIS CENTERED
OVER AR...A CLOSED LOW CENTERED OVER THE NV/UT/AZ BORDER
AREA...AND A LARGE SCALE TROUGH CARVED OUT ACROSS SOUTHEAST
CANADA/GREAT LAKES REGION...FEATURING A SHORTWAVE TROUGH DIVING
INTO NORTHERN MN. VISIBLE SATELLITE CONFIRMS THAT CLOUDY/MOSTLY
CLOUDY SKIES HAVE OVERTAKEN THE ENTIRE CWA...LARGELY A FUNCTION OF
TWO AREAS OF CONVECTION. FIRST...ACROSS COUNTIES GENERALLY ALONG
THE I-80 CORRIDOR...A FAIRLY PERSISTENT EAST-WEST BAND OF ELEVATED
SHOWERS/WEAK STORMS HAS HUNG AROUND NEARLY ALL DAY...AND SEEMS TO
BE LARGELY TIED TO AN AREA OF MID LEVEL CONVERGENCE EVIDENT AROUND
700 MILLIBARS...WITHIN THE ENTRANCE REGION OF AN UPPER JET STREAK
CENTERED DOVER NORTHERN IA/SOUTHERN MN. JUST SOUTH OF THIS ARA OF
CONVECTION...THE BOTTOM TWO ROWS OF NEB COUNTIES HAVE REMAINED
LARGELY DRY THIS AFTERNOON. HOWEVER...ONCE YOU GET TO THE STATE
LINE AND SOUTHWARD INTO KS...AN COMPLETELY SEPARATE AREA OF
SCATTERED CONVECTION HAS BLOSSOMED WITH DAYTIME HEATING...MUCH LIKE
YESTERDAY. THIS CONVECTION HAS FIRED IN RESPONSE TO 1000-2000 J/KG
MLCAPE PER LATEST RUC ANALYSIS IN AN UNCAPPED ENVIRONMENT WITH
STEEP LOW LEVEL LAPSE RATES...BUT WITH FAIRLY POOR MID LEVEL LAPSE
RATES AND ONLY AROUND 20-25 KT OF DEEP LAYER SHEAR. MOST OF THESE
STORMS ARE LIKELY ONLY PRODUCING BRIEF HEAVY RAINS...WIND GUSTS OF
30-40 MPH AND MAYBE SMALL HAIL. DUE TO THE CONVECTION AND VARIABLE
CLOUD COVER...HIGH TEMPS THIS AFTERNOON WERE AN ADVENTURE...AND IN
THE END IT APPEARS MOST OF KS ZONES TOPPED OUT AROUND 90...WITH
MID-UPPER 80S IN SOUTHERN NEB ZONES...BUT ONLY 70S ALONG AND NEAR
THE INTERSTATE 80 CORRIDOR.
TURNING TO THE FORECAST INTO THIS EVENING/TONIGHT...THE BIG
PICTURE ALOFT INVOLVES THE MID LEVEL FLOW TURNING MORE NORTHERLY
OVER THE CWA AND ALSO STARTING TO DRY OUT FROM NORTH-TO-SOUTH IN
RESPONSE TO THE PASSAGE OF THE AFOREMENTIONED GREAT LAKES SHORTWAVE
TROUGH TOWARD EASTERN IA/WI/MI. AS THIS OCCURS...HOWEVER...DECENT
MID LEVEL THETA-E ADVECTION/CONVERGENCE WILL CONTINUE WELL THROUGH
THE NIGHT ESPECIALLY ACROSS SOUTHERN PORTIONS OF THE CWA...AND FOR
SEVERAL HOURS WILL LIKELY SEE A BLEND OF THE DIURNALLY-DRIVEN
AFTERNOON ACTIVITY ALONG WITH ADDITIONAL...SOMEWHAT HIGHER-BASED
ACTIVITY. MEANWHILE...EXPECT THE ACTIVITY NEAR THE I-80 CORRIDOR
TO LARGELY MOVE OUT AND/OR FADE AWAY WITHIN THE NEXT FEW HOURS.
POP-WISE TONIGHT...HAVE A DECENT GRADIENT RANGING FROM ONLY SLIGHT
20S NORTHEAST TO 40S-60S IN SOUTHERN ZONES ESPECIALLY KS. WOULD BE
SURPRISED TO SEE A THREAT OF STRONG STORMS LAST PAST
MIDNIGHT...BUT BETWEEN NOW AND THEN CERTAINLY A FEW COULD WARRANT
SPECIAL WEATHER STATEMENTS. AS FOR LOW TEMPS TONIGHT...MADE ALMOST
NO CHANGE...USING A GUIDANCE BLEND TO AIM FOR UPPER 50S/NEAR 60
NORTH TO UPPER 60S SOUTH. ALTHOUGH SOME PATCHY FOG IS NOT OUT OF
THE QUESTION AS SEEN THIS MORNING...DO NOT THINK IT WILL BE
WIDESPREAD OR VERY IMPACTFUL...SO HAVE OMITTED FROM GRIDS.
FOR THE DAYTIME HOURS THURSDAY 12Z-00Z/7AM-7PM...THE BIG PICTURE
ALOFT INVOLVES THE CWA REMAINING UNDER A TRANSITION ZONE BETWEEN
THE GREAT LAKES SHORTWAVE TROUGH...A RIDGE TO THE SOUTH...AND THE
CLOSED LOW OVER THE INTERMOUNTAIN WEST. FROM THE MID LEVELS DOWN
TO THE LOW LEVELS...INCREASINGLY DRIER AND MORE STABLE AIR WILL
CONTINUE ADVECTING DOWN FROM THE NORTHEAST...WITH THE LOW LEVEL
DRY PUSH EMANATING FROM AN EXPANSIVE SURFACE HIGH SETTLING INTO
THE EASTERN ND/NORTHERN MN AREAS. THERE SHOULD BE A DECENT SKY
COVER GRADIENT BETWEEN MOSTLY SUNNY NORTHEAST TO CLOUDY/MOSTLY
CLOUDY SOUTHWEST...THANKS TO A LINGERING BATCH OF MID LEVEL
SATURATION. UNDER THIS SATURATED LAYER...WILL LIKELY SEE SOME
LINGERING SHOWERS/WEAK STORMS DURING THE DAY MAINLY ACROSS THE
SOUTHWEST 1/4 OF THE CWA...BUT POSSIBLY AS FAR NORTH AS A
GOTHENBURG-HEBRON LINE IN THE MORNING. POPS RANGE FROM ONLY 20-40
PERCENT...AND ITS INTERESTING TO NOTE THAT THE LATEST 4KM WRF-NMM
ACTUALLY SHOWS THE VAST MAJORITY OF THE CWA GOING PRECIP-FREE
AFTER MID-MORNING. AT THE SURFACE...STEADY EAST-NORTHEAST BREEZES
OF 10-15 MPH WILL PREVAIL MOST OF THE DAY...USHERING IN LOWER
DEWPOINTS ONLY IN THE UPPER 40S/LOW 50S IN THE NORTHEAST 1/2 OF
THE CWA...WITH MID 50S TO LOWER 60S SOUTHWEST. ALTHOUGH A
TIGHT SKY COVER GRADIENT COULD MAKE HIGH TEMPS A CHALLENGE...FELT
THAT INCREASING SUNSHINE IN THE NORTHEAST ARGUED FOR SLIGHTLY
WARMER TEMPS...AND IN FACT RAISED NEARLY THE ENTIRE CWA 2-4
DEGREES FROM PREVIOUS BASED ON A GUIDANCE BLEND...WITH MOST AREAS
ENDING UP SOMEWHERE BETWEEN 79-83...OR RIGHT ABOUT NORMAL FOR THE
DATE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 435 PM CDT WED SEP 11 2013
MAIN CONCERNS IN THE LONG TERM WILL FOCUS ON INTERMITTENT CHANCES
FOR SHOWERS AND THUNDERSTORMS AS WELL AS RESULTING TEMPERATURES
THROUGHOUT THE WEEK.
BY 0Z FRIDAY...THE CENTRAL PLAINS REMAINS ON THE CUSP OF TWO UPPER
LEVEL SYSTEMS...A DEEPENING TROUGH TO THE EAST AND A DEGRADING RIDGE
TO THE WEST. THE CUTOFF LOW ACROSS THE DESERT SOUTHWEST THIS
WEEK...WILL BEGIN TO BECOME INGESTED IN THE UPPER LEVEL
FLOW...THEREBY DEGRADING THE RIDGE AND BRINGING CHANCES FOR SHOWERS
TO THE PLAINS.
PLENTY OF MOISTURE AND UPSLOPE ISENTROPIC FLOW WILL BE ON TAP FRIDAY
MORNING ALONG PORTIONS OF THE FRONT RANGE. HOWEVER...STRONG
NORTHERLY FLOW ON THE BACKSIDE OF THE UPPER TROUGH WILL INTRODUCE A
BATTLE OF DRIER AIR TO THE NORTHEAST AND MOIST AIR TO THE SOUTHWEST.
EXPECTING A TIGHT GRADIENT OF SHOWERS TO FORM WITH THE BULK OF THE
PRECIPITATION REMAINING TO THE SOUTH AND EAST THROUGH FRIDAY MIDDAY.
AS THE RIDGE BREAKS DOWN...SHIFTING THE TROUGH EASTWARD...SHOWERS
SHOULD OVERRIDE THE RIDGE IN THE FORM OF A WARM FRONT INTO AT LEAST
THE NEBRASKA ZONES BY FRIDAY EVENING.
AS CUTOFF LOW BECOMES INGESTED INTO THE MAIN FLOW AND THE FRONT LIFTS
NORTH OVERNIGHT...STALLING OUT ACROSS NORTHERN NEBRASKA...SHOWERS
WILL ALSO LIFT NORTH. WENT AHEAD AND KEPT AT LEAST CHANCE CHANCES
FOR SHOWERS ACROSS THE OUTLOOK AREA THROUGH SATURDAY...ALTHOUGH WITH
LATER MODEL RUNS...THESE SHOWERS MAY END UP BEING SHIFTED A BIT
FURTHER NORTH. HIGH TEMPERATURES ON SATURDAY WILL BE A CONCERN GIVEN
CLOUD COVER AND PRECIPITATION CHANCES AS MUCH OF THE OUTLOOK AREA
WILL BE ON THE SOUTHERN SIDE OF THE WARM FRONT. BUMPED TEMPERATURES
UP A FEW DEGREES...ANTICIPATING A DECENT WARM UP.
A SECONDARY UPPER LEVEL LOW SWINGING ACROSS CANADA WILL HELP DRIVE THE
FRONT BACK THROUGH THE PLAINS IN THE FORM OF A COLD FRONT SATURDAY
EVENING INTO SUNDAY MORNING. THIS WILL LIKELY BE THE BEST SHOT AT
PRECIPITATION AND EVEN THUNDERSTORMS WITH MUCAPE VALUES NEAR 500-750
J/KG.
SHOWERS LINGER THROUGH SUNDAY NIGHT WITH THE BOUNDARY STALLING
ACROSS KANSAS. HEADING INTO THE WORKWEEK...YET ANOTHER UPPER LEVEL
TROUGH WILL BEGIN TO DIVE ACROSS THE WEST COAST. THIS WILL DRIVE AN
UPPER LEVEL SHORT WAVE THROUGH THE REGION. AT THE SURFACE...LOW
PRESSURE ALONG THE FRONT RANGE WILL SLOWLY LIFT THE BOUNDARY AS A
WARM FRONT ACROSS THE OUTLOOK AREA. THUS...WITH LIFT ALONG THIS
FRONTAL BOUNDARY MONDAY NIGHT THROUGH TUESDAY LOOK TO BE WET AS
WELL.
BY MIDWEEK...PREVIOUS RUNS OF THE ECWMF SHOWED A TROUGH OVER THE
REGION...WITH MUCH COOLER 850 MB TEMPERATURES. HOWEVER...THE LATEST
RUN OF THE ECMWF ARE BEGINNING TO COME INTO PHASE WITH THE GFS AND
THE TROUGH REMAINING ACROSS THE WESTERN COAST. THE RIDGE BEGINS TO
BREAKDOWN...HOWEVER...WITH A SHORT WAVE SLIDING ACROSS THE REGION
WEDNESDAY.
AS FOR TEMPERATURES...EXPECT A FAIRLY MILD WEEK AHEAD AS HIGH
TEMPERATURES WILL RANGE FROM 70S TO MID 80S IN MOST AREAS. AS STATED
BEFORE...SATURDAYS HIGH TEMPERATURES COULD EASILY BE WARMER GIVEN
CLOUD COVER AND PRECIPITATION WITH THE FRONTAL BOUNDARY.
TEMPERATURES DIP BACK DOWN INTO THE 70S ON MONDAY WITH THE PASSAGE
OF THE COLD FRONT. THE MIDWEEK WARMS BACK UP...HOWEVER...WITH THE
LIFTING WARM FRONT.
&&
.AVIATION...(FOR THE 18Z KGRI TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1243 PM CDT WED SEP 11 2013
HAVE AIMED FOR VFR CEILING/VISIBILITY THROUGHOUT THE NEXT 24
HOURS...ALTHOUGH THE MAIN CAVEAT WOULD BE IF A BRIEF SHOWER OR
THUNDERSTORM WOULD HAPPEN TO PASS OVERHEAD MAINLY THIS
AFTERNOON/EVENING. SPEAKING OF WHICH...RIGHT OFF THE BAT DURING
THE 1ST HOUR OF THE PERIOD THERE IS A DECENT CHANCE THAT A WEAK
THUNDERSTORM COULD MOVE THROUGH...AND HAVE INTRODUCED A TEMPO GROUP
FOR THIS. BEYOND 19Z...AND THROUGH THE REST OF THE EVENING AND
PART OF THE LATE NIGHT...HAVE MAINTAINED A GENERIC VCTS/VICINITY
THUNDERSTORM MENTION...ALTHOUGH KGRI APPEARS TO BE ON THE NORTHERN
EXTENT OF THUNDERSTORM CHANCES...WITH BETTER CHANCES FOCUSED
50-100 MILES FARTHER SOUTH. BEYOND 09Z THROUGH THE FINAL 9 HOURS
OF THE PERIOD...HAVE DROPPED ALL SHOWER/THUNDERSTORM MENTION AS EVEN
LOW CHANCES SHOULD BE SHUNTED SOUTH OF THE AREA BY THEN PER
LATEST MODELS/GUIDANCE. NOT ACCOUNTING FOR POSSIBLE THUNDERSTORM
OUTFLOW...SURFACE WINDS SHOULD PREVAIL FROM A NORTHEAST DIRECTION
THROUGH THE PERIOD...WITH SPEEDS AVERAGING AROUND 7KT OR LESS INTO
EARLY THURSDAY MORNING...BEFORE PICKING UP A BIT BY LATE MORNING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...SALTZMAN
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1251 AM CDT WED SEP 11 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 317 PM CDT TUE SEP 10 2013
MORNING MAP ANALYSIS INDICATES A CLOSED MID LEVEL LOW OVER THE
SOUTHWESTERN CONUS...WITH RIDGING OVER THE EAST. A MID LEVEL
SHORTWAVE IS ALSO NOTED OVER SOUTH CENTRAL CANADA AND MOVING EAST.
THE PRIMARY AXIS OF MID TO UPPER LEVEL JET ENERGY EXTENDS FROM
WESTERN CANADA...SOUTHEAST INTO THE NORTHERN PLAINS...AND THEN
EAST/NORTHEAST INTO SOUTHEASTERN CANADA. MID TO UPPER LEVEL FLOW
IS FAIRLY WEAK OVER OUR AREA AS A RESULT...ONLY MAXING OUT AT
AROUND 30KTS AT VARIOUS POINT BETWEEN 500MB AND 200MB PER 12Z
SOUNDING DATA FROM KLBF AND KOAX. WATER VAPOR IMAGERY ALSO SHOWS
THE AFOREMENTIONED MID LEVEL LOW OVER THE SOUTHWESTERN CONUS...AS
WELL AS THE MID LEVEL SHORTWAVE OVER SOUTH CENTRAL CANADA. THE MID
LEVEL LOW OVER THE SOUTHWESTERN CONUS IS HELPING PULL MID LEVEL
MOISTURE NORTHWARD FROM MEXICO AND AS A RESULT...INCREASED VALUES
OF MID LEVEL MOISTURE ARE NOTED EXTENDING FROM THE SOUTHWESTERN
CONUS...NORTHEAST INTO THE ROCKY MOUNTAIN RANGE AND INTO PORTIONS
OF THE NORTHERN AND CENTRAL PLAINS. AT THE SURFACE A NEARLY
STATIONARY BOUNDARY IS NOTED EXTENDING FROM WESTERN KANSAS INTO
EASTERN NEBRASKA AND WESTERN IOWA. THIS BOUNDARY BISECTS OUR CWA
AND AS A RESULT...THE LOW LEVEL WIND FIELD ACROSS THE NORTHWESTERN
HALF OF OUR CWA REMAINS FROM THE NORTHEAST...WHILE LOCATIONS
FARTHER SOUTHEAST CONTINUE TO OBSERVE A SOUTHWESTERLY LOW LEVEL
WIND FIELD.
TO THE SOUTH OF THE LOW LEVEL BAROCLINIC ZONE...AFTERNOON SURFACE
TEMPERATURES HAVE CLIMBED WELL INTO THE 90S...WITH PROXIMITY
SOUNDINGS FROM LAPS AND RAP ANALYSIS INDICATING CONVECTIVE
TEMPERATURES HAVE BEEN REACHED. KUEX INDICATES ISOLATED SHOWER AND
THUNDERSTORM ACTIVITY DEVELOPING FROM WESTERN KANSAS INTO NORTH
CENTRAL KANSAS...INCLUDING SOUTHERN PORTIONS OF OUR CWA. THESE
SAME PROXIMITY SOUNDINGS SUGGEST ~1000J/KG OF POTENTIAL ENERGY IS
READY FOR UPDRAFT PRODUCTION...BUT VERY LITTLE IN THE WAY OF DEEP
LAYER BULK SHEAR IS PRESENT...PERHAPS NO HIGHER THAN 15 OR 20KTS.
GIVEN ALL THIS...ISOLATED SHOWER AND THUNDERSTORM ACTIVITY WILL
LIKELY PERSIST ACROSS SOUTHEASTERN PORTIONS OF OUR CWA THROUGH THE
REST OF THIS AFTERNOON. MULTIPLE SETS OF GUIDANCE SUGGEST LOW
LEVEL CONVERGENCE AND RESULTANT FORCING ALONG THE LOW LEVEL
BAROCLINIC ZONE MAY ALSO PROMOTE ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM CONVECTION ACROSS THE AREA. AS A RESULT...KEPT THE
~20% POP GOING ACROSS MUCH OF THE CWA 21-00Z.
ANY SURFACE-BASED CONVECTION THAT CAN BE REALIZED THIS AFTERNOON
AND/OR EVENING ACROSS OUR SOUTHERN COUNTIES...OR FARTHER NORTH
ALONG THE LOW LEVEL BAROCLINIC ZONE...SHOULD DISSIPATE SHORTLY
AFTER SUNSET AS DIABATIC HEATING IS LOST. THAT BEING
SAID...GUIDANCE SUGGESTS THE MID LEVEL SHORTWAVE...CURRENTLY OVER
SOUTH CENTRAL CANADA...WILL MOVE SOUTHEAST THUS PUSHING THE MID
LEVEL JET AXIS FARTHER SOUTH AS WELL. THIS WILL IN TURN PUSH A
30-40KT MID LEVEL JET STREAK FARTHER SOUTH INTO THE UPPER
MISSISSIPPI VALLEY AND PORTIONS OF THE NORTHERN PLAINS...WITH THE
RIGHT-REAR QUADRANT OF THIS JET STREAK SETTING UP OVER NORTHERN
PORTIONS OF OUR CWA. IT APPEARS AS THOUGH THERE WILL BE ENOUGH OF
A THERMALLY-DIRECT CIRCULATION AND RESULTANT OMEGA FOR ADDITIONAL
SHOWER AND THUNDERSTORM DEVELOPMENT...PRIMARILY ACROSS OUR
NORTH...OVERNIGHT TONIGHT AND AS A RESULT...~30% POPS HAVE BEEN
PLACED PRIMARILY ACROSS THE NORTHERN HALF OF OUR CWA 00-12Z
WEDNESDAY.
THERE MAY BE SOME LINGERING SHOWER AND THUNDERSTORM ACTIVITY EARLY
WEDNESDAY MORNING...BUT GUIDANCE SUGGESTS THIS ACTIVITY SHOULD
DISSIPATE BY AROUND SUNRISE. DRY CONDITIONS WILL MORE THAN LIKELY
BE OBSERVED THROUGH MUCH OF THE DAY WEDNESDAY...HOWEVER THE LOW
LEVEL BAROCLINIC ZONE...CURRENTLY OVER CENTRAL PORTIONS OF OUR
CWA...IS ONLY EXPECTED TO SHIFT SLIGHTLY SOUTH TONIGHT AND BY
WEDNESDAY AFTERNOON IS EXPECTED TO STRETCH ACROSS THE SOUTHEASTERN
ONE-THIRD OF OUR CWA. LOW LEVEL CONVERGENCE AND RESULTANT FORCING
ALONG THE LOW LEVEL BAROCLINIC ZONE MAY PROMOTE ANOTHER ROUND OF
AFTERNOON SHOWER AND THUNDERSTORM ACTIVITY ON WEDNESDAY AND AS A
RESULT...20-30% POPS HAVE BEEN PLACED ACROSS PORTIONS OF THE CWA
FOR WEDNESDAY AFTERNOON AND EVENING...WITH THE HIGHEST POPS
RELEGATED TO OUR SOUTHEAST IN CLOSEST PROXIMITY TO THE LOW LEVEL
BAROCLINIC ZONE.
GUIDANCE SUGGESTS POTENTIAL ENERGY WILL NOT CLIMB MUCH HIGHER THAN
1000J/KG THIS AFTERNOON AND EVENING...AND WITH LITTLE IN THE WAY
OF DEEP LAYER BULK SHEAR...THE THREAT FOR SEVERE WEATHER SEEMS
FAIRLY LIMITED. THAT BEING SAID...THERE IS A CHANCE UPDRAFT
STRENGTH COULD BE STRONG ENOUGH TO PROMOTE SOME HAIL...CURRENTLY
EXPECTED TO REMAIN SUB-SEVERE...AND SO WILL OUTLOOK THIS IN THE
HWO. IN ADDITION...FORECAST PROXIMITY SOUNDINGS SUGGEST FAIRLY
DEEP INVERTED-V SOUNDINGS...TO BETWEEN 800MB AND 750MB...COULD
ALSO PROMOTE A WIND GUST THREAT. WILL GO AHEAD AND OUTLOOK BRIEF
WIND GUSTS TO AROUND 50 MPH IN THE HWO FOR THIS AFTERNOON AND
EVENING AS WELL. TROPOSPHERIC CONDITIONS...FOR LOCATIONS NEAR AND
AHEAD OF THE LOW LEVEL BAROCLINIC ZONE...APPEAR AS THOUGH THEY
WILL BE SIMILAR ON WEDNESDAY WHEN COMPARED TO TODAY AND AS A
RESULT...WILL GO AHEAD AND OUTLOOK THE THREAT FOR SUB-SEVERE HAIL
AND WIND GUSTS...PRIMARILY ACROSS OUR SOUTH...FOR WEDNESDAY
AFTERNOON AND EVENING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 317 PM CDT TUE SEP 10 2013
WEDNESDAY NIGHT...THE SFC COOL FRONT WILL REMAIN WELL TO THE SOUTH
OF OUR FORECAST AREA AND WILL LIKELY BE LOCATED OVER OKLAHOMA. AN
UPPER LEVEL TROUGH WILL BE SCOOTING TO OUR NORTHEAST AND THE BEST
CHANCE OF SHOWERS AND THUNDERSTORMS WILL BE ASSOCIATED WITH AN
OVERRUNNING SET UP ACROSS KANSAS. NEBRASKA WILL BE SO FAR NORTH OF
THE FRONT WITH DRIER AIR STARTING TO WORK IN AND HENCE LESSER POPS
AS YOU HEAD NORTH THROUGH OUR NEBRASKA ZONES.
THURSDAY AND FRIDAY...A SFC HIGH WILL SLIDE INTO THE GREAT LAKES
RESULTING IN A WIND SHIFT AS WE BEGIN TO GET MORE OF AN EASTERLY
UPSLOPE FLOW ON THURSDAY AND THEN A RETURN SOUTHEASTERLY STILL
SOMEWHAT UPSLOPE FLOW ON FRIDAY. THIS WILL RESULT IN THUNDERSTORM
CHANCES ACROSS THE HIGH PLAINS AND THEN SLIGHT CHANCES OF SHOWERS
AND THUNDERSTORMS ACROSS OUR FAR SOUTHWESTERN COUNTIES AS WESTERN
THUNDERSTORMS TRY TO MAKE IT EAST...BUT WILL LIKELY STRUGGLE. THE
TRI CITIES AND POINTS NORTH AND EAST ARE LIKELY GOING TO BE DRY
DURING THIS PERIOD. TEMPERATURES SHOULD BE BELOW NORMAL FOR THE
FIRST TIME SINCE AROUND THE MIDDLE OF AUGUST...WHICH WAS THE LAST
TIME WE SAW HIGHS ONLY IN THE 70S. ALTHOUGH BOTH THURSDAY AND
FRIDAY WILL BE COOL IN THE 70S FOR HIGHS...FRIDAY WILL BE THE
COOLEST OF THE TWO DAYS WITH HIGHS ONLY IN THE LOWER TO MID 70S.
WEEKEND...THE COOL WEATHER WILL PERSIST WITH CLOUDS AND SEVERAL
CHANCES OF SHOWERS AND THUNDERSTORMS AS WEAK PIECES OF A SHORTWAVE
TROUGH TRACK THROUGH THE CENTRAL PLAINS. PRECIPITATION CHANCES
SEEM FAIR GENERALLY IN THE 30 TO 40 PERCENT RANGE. THESE CHANCES
MAY BE RAISED IN COMING DAYS IF CURRENT WET LOOKING MODEL TRENDS
CONTINUE. HIGHS SHOULD CONTINUE TO BE IN THE 70S ACROSS NEBRASKA
TO NEAR 80 IN KANSAS. HOWEVER...COULD SEE THESE HIGHS BEING
LOWERED...PARTICULARLY ON SUNDAY...IF RAIN CHANCES INCREASE DUE TO
CLOUDS AND COOLER EAST NORTHEASTERLY FLOW. CONSEQUENTLY...THIS IS
A HEADS UP THAT OUR FORECAST HIGHS ARE CURRENTLY ON THE WARMER END
OF THE MODEL GUIDANCE...SO DO NOT BE SURPRISED IF HIGHS ARE
LOWERED WITH FUTURE FORECAST UPDATES.
MONDAY AND TUESDAY...CONFIDENCE IS LOW WITH SOME MODELS INDICATING
CONTINUED SHORT WAVES AND THUNDERSTORM CHANCES WHILE OTHER
FORECAST MODELS DRY OUT. POPS WILL BE LOW DUE TO UNCERTAINTY.
TEMPERATURES SHOULD BE SOMEWHAT NEAR NORMAL AND WILL BE CALLING
FOR HIGHS IN THE UPPER 70S TO LOWER 80S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1247 AM CDT WED SEP 11 2013
MAIN STORY THROUGH THIS TAF PERIOD LIES WITH THE CONTINUED
PRESENCE OF THE SFC FRONTAL BOUNDARY...AND CHANCES FOR
PRECIPITATION. THE REST OF TONIGHT...CLOUDS EXPECTED TO REMAIN IN
THE MID/UPPER LEVELS...AND CANT COMPLETELY RULE OUT SOME SHOWER
ACTIVITY SO WILL CARRY A VCSH MENTION. SHOULD SEE DRY CONDITION
THROUGH MOST OF THE DAYTIME HOURS...BUT WITH THE SFC FRONT
REMAINING IN THE AREA AND ANY ADDITIONAL DISTURBANCES...THE
POTENTIAL FOR SOME SCATTERED PRECIP WILL RETURN...SO INSERTED
ANOTHER VC MENTION FOR THE AFTERNOON/EVENING HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...BRYANT
LONG TERM...WESELY
AVIATION...ADO
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
948 PM EDT THU SEP 12 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA FRIDAY MORNING. CANADIAN HIGH
PRESSURE WILL BRING FALL-LIKE WEATHER THIS WEEKEND. A SECOND
CANADIAN HIGH WILL DROP SOUTHEAST INTO THE REGION EARLY NEXT
WEEK...BRINGING A REINFORCEMENT OF DRY AND MILD AIR FOR MUCH OF
THE UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 930 PM THURSDAY...TAIL END OF MID LEVEL SUBSIDENCE ACROSS
THE FA THIS EVENING HAS KEPT A TEMPORARY LID ON CONVECTIVE
DEVELOPMENT. IE. NO TSRA/SHRA DEVELOPMENT ALONG THE
AFTERNOON/EVENING SEA BREEZE. THE SUBSIDENCE LIES BETWEEN THE
EXITING S/W TROF...WHAT WAS ONCE AN UPPER LOW OFF THE SE U.S.
COAST...OVER THE ADJACENT ATL WATERS AND THE APPROACHING S/W TROF
FROM THE WEST. FORCING/DYNAMICS FROM THIS UPPER S/W TROF AND FORCING
AHEAD OF THE APPROACHING SFC COLD FRONT...WILL BE ENOUGH TO
CONTINUE LOW CHANCE POPS ACROSS PORTIONS OF THE FA DURING THE
PRE-DAWN FRIDAY HOURS. LEFT OUT THUNDER FOR THE TIME BEING DUE TO
VERY LIMITED AVBL CAPE GIVEN THE TIME OF DAY. CURRENT MIN TEMP
FORECAST LOOKS AOK...WITH CONTINUED TWEAKING OF THE HOURLY
SFC DEWPOINTS BASED ON LATEST OBS/TRENDS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...DIGGING MID TO UPPER TROUGH EXTENDING DOWN
FROM THE GREAT LAKES WILL PUSH A COLD FRONT THROUGH THE AREA ON
FRIDAY. LATEST MODELS SHIFT THE BOUNDARY TO THE CAPE FEAR COAST
THROUGH FRI MORNING...BUT LOOKS LIKE WINDS WILL BACK AS SEA BREEZE
DEVELOPS. THIS WILL PRODUCE ENOUGH CONVERGENCE ALONG THE COAST
ALONG WITH ENOUGH LINGERING MOISTURE TO PRODUCE CLOUDS. WILL LEAVE
SOME CONVECTION POSSIBLE THROUGH EARLY AFTERNOON...BUT DRY COOL
AIR WILL PUSH IN BEHIND THE FRONT ADVECTING FROM NORTHWEST TO
SOUTHEAST AS WINDS SHIFT AROUND TO THE WEST-NORTHWEST BEHIND THE
FRONT. DEWPOINT TEMPS WILL DROP A GOOD 5 DEGREES THROUGH FRI
AFTERNOON. THIS COOL CANADIAN HIGH PRESSURE WILL BUILD INTO THE
AREA OVER THE WEEKEND PRODUCING UNSEASONABLY COOL AND DRY WEATHER.
THE MID TO UPPER TROUGH ACTUALLY BECOMES A BIT BROADER OVER THE
SOUTHEAST AS IT MOVES SLOWLY ACROSS TO NEW ENGLAND LATE FRI
THROUGH EARLY SAT. THIS WILL KEEP WINDS MORE WESTERLY IN THE MID TO
UPPER LEVELS THROUGH EARLY SATURDAY. A MORE SUBSTANTIAL PUSH OF
DEEP COOL AND DRY AIR WILL DEVELOP AS THIS H5 TROUGH CLEARS THE
COAST ON SATURDAY. EXPECT INLAND AREAS TO EXPERIENCE COOLER AND
DRIER CONDITIONS INITIALLY THROUGH LATE FRI BUT THIS SECONDARY
PUSH ON SAT WILL KEEP TEMPS BELOW 80 IN SPOTS ON SAT AND TEMPS
WILL DROP INTO THE LOWER 50S OVER PORTIONS OF CWA SAT NIGHT.
MOISTURE TRAPPED UNDER SUBSIDENCE INVERSION ON SATURDAY WILL
PRODUCE SOME CLOUDS...ESPECIALLY CLOSE TO THE COAST. THIS WILL
ALSO HELP TO LIMIT HEATING. THE COMBINATION OF CAA AND CLOUD
DEVELOPMENT WILL KEEP TEMPS A GOOD 5 TO 10 DEGREES COOLER THAN
PREVIOUS DAYS AND THE DRIER AIR WILL MAKE IT FEEL EVEN COOLER.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...WEAK RIDGING ALOFT AT THE START OF THE PERIOD
WILL SLOWLY BREAK DOWN NEXT WEEK. SURFACE HIGH OVERHEAD ON SUN WILL
YIELD TO A WEAK COLD FRONT MOVING IN FROM THE NORTH LATE MON OR
EARLY TUE. AHEAD OF THE FRONT LIGHT RETURN FLOW AND A BUMP IN LOW
LEVEL MOISTURE COULD PRODUCE ISOLATED SHOWERS MON AFTERNOON...MAINLY
NEAR THE COAST. WILL NOT CARRY A ZERO POP BUT WILL KEEP POP 10 OR
LESS. COOLER AND DRIER HIGH PRESSURE WILL BUILD IN FROM THE NORTH
BEHIND THE FRONT. LIMITED MOISTURE ALONG THE FRONT AND LACK OF
FORCING...INSTABILITY AND MID LEVEL SUPPORT SUGGESTS THE FRONT WILL
BE LITTLE MORE THAN A WIND SHIFT WITH LIMITED CLOUD COVER. HIGH
SLOWLY SHIFTS EAST NEXT WEEK...EVENTUALLY MOVING OFF THE MID
ATLANTIC COAST WED/THU. NORTHERLY FLOW TUE INTO WED WILL KEEP
TEMPERATURES NEAR TO SLIGHTLY BELOW CLIMO AND LIMIT PRECIP CHANCES.
DEVELOPING RETURN FLOW LATE NEXT WEEK LEADS TO A SLIGHT INCREASE IN
MOISTURE. LOW LEVEL MOISTURE IN CONCERT WITH WEAKENING MID LEVEL
SUBSIDENCE MAY ALLOW FOR DEVELOPMENT OF SOME DEEPER CONVECTION. FOR
NOW WILL MAINTAIN INHERITED SILENT POP WED/THU.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...VFR CONDITIONS ARE EXPECTED THIS EVENING WITH SOUTHWEST
WINDS 3-6 KTS. THIS LOW-LEVEL FLOW SHOULD INHIBIT FOG FORMATION...SO
DO NOT ANTICIPATE ANY VSBY RESTRICTIONS OVERNIGHT. AN APPROACHING
COLD FRONT WILL MOVE THROUGH THE CWA EARLY FRIDAY. THE TIMING OF
FROPA IS NOT CONDUCIVE FOR WIDESPREAD SHOWERS...BUT WILL STILL
MENTION VCSH ON FRIDAY MORNING AS HI-RES GUIDANCE HINTS AT SOME
ISOLATED LIGHT SHRA BEFORE 12Z. BY MIDDAY THE FRONT SHOULD BE OFF
THE CAROLINA COAST...AND DRIER MID-LEVEL AIR WILL FILTER INTO OUR
AREA BEHIND THE FRONT. THE WINDS WILL BECOME NORTHWEST AOB 10 KTS
DURING THE DAY FOLLOWING FROPA. THE GFS HINTS AT SOME CONVECTIVE
ACTIVITY ALONG THE COAST FRIDAY AFTN...BUT SUBSIDENCE ALOFT AND AN
INVERSION AROUND 650 MB SHOULD EFFECTIVELY LIMIT STORM DEVELOPMENT.
THEREFORE...WILL ONLY INCLUDE SCT CU FOR THE COASTAL SITES ATTM.
EXTENDED OUTLOOK...VFR WILL PREVAIL THROUGH THE EXTENDED PERIOD.
VERY SLIGHT CHANCE OF SHOWERS LATE MONDAY INTO EARLY TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM THURSDAY...THE SFC PG HAS FINALLY BEGUN TO TIGHTEN
ACROSS THE FA...AHEAD OF THE APPROACHING COLD FRONT. THE LATEST OBS
IE. OCPN7 AND 41013...INDICATE SW 10-15 KT WITH GUSTS UP TO 17
KT. THE LATEST HRRR CONTINUES TO ILLUSTRATE SUSTAINED WINDS
APPROACHING 20 KT OVERNIGHT. WILL NOT GO TO THAT EXTREME BUT WILL
INDICATE INCREASING TO SUSTAINED AROUND 15 KT...WITH GUSTS UP TO
20 KT. SFC PRESSURE PATTERN AHEAD OF THE COLD FRONT TO YIELD A SW
DIRECTION THIS EVENING...BECOMING WSW TOWARD DAYBREAK AS THE
FRONT MOVES IN CLOSER PROXIMITY. SIGNIFICANT SEAS OF 2 TO 3 FT
THRUOUT THIS EVENING...WITH 4 FOOTERS POSSIBLE ACROSS THE OUTER
WATERS OFF CAPE FEAR AND THE EASTERN PORTIONS OF AMZ252...IE. EAST
OF HOLDEN BEACH...DURING THE FRI AM HOURS. THE 8 TO 9 SECOND
PERIOD EASTERLY GROUND SWELL WILL DOMINATE THIS EVENING...HOWEVER
THERE WILL BE AN INFLUX/INCREASE OF 3 TO 6 SECOND PERIOD WIND
DRIVEN WAVES...MAINLY AFTER MIDNIGHT. HENCE...THE 4 FOOTERS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 PM
THURSDAY...COLD FRONT WILL DROP SOUTHEAST INTO THE WATERS ON
FRIDAY BUT WINDS WILL BACK SOME THROUGH THE DAY AS SEA BREEZE
DEVELOPS. THEN BY NIGHTFALL...WINDS WILL SWING AROUND TO THE
NORTHEAST UP TO 10 TO 15 KTS AS BOUNDARY PUSHES SOUTH. EXPECT A
SURGE OF COOLER AND DRIER AIR ADVECTING IN AS COOL CANADIAN HIGH
PRESSURE BUILDS INTO AREA BEHIND THE FRONT.
EXPECT A SECONDARY PUSH OF COOL AND DRY AIR ON SAT AS MID TO
UPPER TROUGH SWINGS OFF THE COAST AND HIGH PRESSURE CONTINUES TO
BUILD SOUTH PRODUCING A DEEPER DRIER AND COOLER NORTHERLY FLOW.
THIS SECONDARY SURGE SHOULD PRODUCE WINDS UP TO 15 TO 20 KTS WITH
HIGHER GUSTS LATE SATURDAY INTO EARLY SUNDAY. SEAS WILL INCREASE
FROM 2 TO 3 FT EARLY FRI TO 3-5 FEET FRI NIGHT INTO SATURDAY AS
WINDS INCREASE. LATEST WNA MODELS SHOW SEAS PEAKING AROUND 5 FT POSSIBLY
WARRANTING A SCEC HEADLINE...BUT THE SEAS COULD END UP BEING
HIGHER IF SURGE PRODUCES GREATER WINDS IN WELL MIXED ATMOSPHERE
DUE TO WARMER WATERS THIS TIME OF YEAR.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...NORTHEAST FLOW BETWEEN 10 AND 15 KT AT THE
START OF THE PERIOD WILL VEER TO EASTERLY AS HIGH TO THE NORTH
SHIFTS EAST. LITTLE CHANGE TO THE GRADIENT IS EXPECTED AND WINDS ARE
LIKELY TO REMAIN 10 TO 15 KT THROUGH SUN. WEAK EAST TO SOUTHEAST
FLOW DEVELOPS MON AS HIGH MOVES FARTHER OFFSHORE. SPEEDS AROUND 10
KT AND SOUTHERLY COMPONENT WILL BE SHORT LIVED. LATE MON/EARLY TUE A
COLD FRONT MOVES SOUTH ACROSS THE WATERS FOLLOWED BY HIGH PRESSURE
BUILDING IN FROM THE NORTHWEST. NORTH TO NORTHEAST FLOW DEVELOPS
WITH SPEEDS A SOLID 15 KT TUE. SEAS START OUT 3 TO 4 FT BUT DROP TO
2 TO 3 FT FOR MON AS WIND SPEEDS DECREASE. INCREASING NORTHEAST FLOW
MON NIGHT AND TUE WILL PUSH SEAS BACK TO 2 TO 4 FT BY THE END OF THE
PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...DCH
SHORT TERM...RGZ
LONG TERM...III
AVIATION...MJC/DL
MARINE...
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
758 PM EDT THU SEP 12 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA FRIDAY MORNING. CANADIAN HIGH
PRESSURE WILL BRING FALL-LIKE WEATHER THIS WEEKEND. A SECOND
CANADIAN HIGH WILL DROP SOUTHEAST INTO THE REGION EARLY NEXT
WEEK...BRINGING A REINFORCEMENT OF DRY AIR FOR MUCH OF THE
UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 730 PM THURSDAY...AT THE MOMENT...MID LEVEL SUBSIDENCE
RESIDES ACROSS THE FA...IN TURN KEEPING A TEMPORARY LID ON
CONVECTIVE DEVELOPMENT. IE. NO TSRA/SHRA DEVELOPMENT ALONG THE SEA
BREEZE. THE SUBSIDENCE LIES BETWEEN THE EXITING S/W TROF...WHAT
WAS ONCE AN UPPER LOW OFF THE SE U.S. COAST...OVER THE ADJACENT
ATL WATERS AND THE APPROACHING S/W TROF FROM THE WEST.
FORCING/DYNAMICS FROM THIS S/W TROF ALOFT AND ANY FORCING FROM
THE APPROACHING SFC COLD FRONT...WILL BE ENOUGH TO INTRODUCE POPS
ACROSS THE FA DURING THE PRE-DAWN FRIDAY HOURS...ALBEIT ISOLATED
RAIN SHOWER CHANCE. LEFT OUT THUNDER FOR THE TIME BEING. CURRENT MIN
TEMP FORECAST LOOKS AOK...WITH SOME TWEAKING OF THE HOURLY
DEWPOINTS NEEDED BASED ON LATEST OBS/TRENDS.
PREVIOUS DISCUSSION.............................................
AS OF 3 PM THURSDAY...SHORTWAVE ENERGY MOVING SOUTHEAST
APPROACHING THE CENTRAL CAROLINAS THIS AFTERNOON WAS TRIPPING OFF
SCATTERED SHOWERS AND TSTMS NORTHWEST OF THE FORECAST AREA.
DWINDLING SURFACE HEATING WILL VERY LIKELY CURTAIL AND WEAKEN THIS
ACTIVITY IN THE VERY LATE AFTERNOON TO EARLY EVENING BEFORE IT
EXTENDS INTO OUR COUNTY WARNING AREA. WILL RETAIN ISOLATED SHOWERS
OVER OUR FAR INLAND ZONES INTO EVENING WITH EVIDENT BUT TENUOUS
SUPPORT ALOFT.
OVERNIGHT CONDITIONS SHOULD REMAIN QUIET WITH LIMITED SUPPORT FOR
SHOWERS. SURFACE CONVERGENCE HOWEVER WILL APPROACH THE FORECAST
AREA AFTER 6Z COUPLED WITH WEAK AND ELONGATED IMPULSES ALOFT SO
WILL RETAIN ISOLATED SHOWERS FOR THE OVERNIGHT PERIOD. BECAUSE
OF WSW WIND FLOW IN THE LOW-LEVELS IN THE WARM SECTOR OF THE COLD
FRONT...MINIMUMS WILL REMAIN ELEVATED...WITH OVERNIGHT LOWS
POSSIBLY HOLDING AT 70 OR ABOVE ACROSS PORTIONS OF OUR CENTRAL
ZONES AND ACROSS MOST OF OUR EASTERN ZONES. BY 12Z FRIDAY THE COLD
FRONT WILL BE IMPINGING OUR VERY NORTHERN ZONES.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...DIGGING MID TO UPPER TROUGH EXTENDING DOWN
FROM THE GREAT LAKES WILL PUSH A COLD FRONT THROUGH THE AREA ON
FRIDAY. LATEST MODELS SHIFT THE BOUNDARY TO THE CAPE FEAR COAST
THROUGH FRI MORNING...BUT LOOKS LIKE WINDS WILL BACK AS SEA BREEZE
DEVELOPS. THIS WILL PRODUCE ENOUGH CONVERGENCE ALONG THE COAST
ALONG WITH ENOUGH LINGERING MOISTURE TO PRODUCE CLOUDS. WILL LEAVE
SOME CONVECTION POSSIBLE THROUGH EARLY AFTERNOON...BUT DRY COOL
AIR WILL PUSH IN BEHIND THE FRONT ADVECTING FROM NORTHWEST TO
SOUTHEAST AS WINDS SHIFT AROUND TO THE WEST-NORTHWEST BEHIND THE
FRONT. DEWPOINT TEMPS WILL DROP A GOOD 5 DEGREES THROUGH FRI
AFTERNOON. THIS COOL CANADIAN HIGH PRESSURE WILL BUILD INTO THE
AREA OVER THE WEEKEND PRODUCING UNSEASONABLY COOL AND DRY WEATHER.
THE MID TO UPPER TROUGH ACTUALLY BECOMES A BIT BROADER OVER THE
SOUTHEAST AS IT MOVES SLOWLY ACROSS TO NEW ENGLAND LATE FRI
THROUGH EARLY SAT. THIS WILL KEEP WINDS MORE WESTERLY IN THE MID TO
UPPER LEVELS THROUGH EARLY SATURDAY. A MORE SUBSTANTIAL PUSH OF
DEEP COOL AND DRY AIR WILL DEVELOP AS THIS H5 TROUGH CLEARS THE
COAST ON SATURDAY. EXPECT INLAND AREAS TO EXPERIENCE COOLER AND
DRIER CONDITIONS INITIALLY THROUGH LATE FRI BUT THIS SECONDARY
PUSH ON SAT WILL KEEP TEMPS BELOW 80 IN SPOTS ON SAT AND TEMPS
WILL DROP INTO THE LOWER 50S OVER PORTIONS OF CWA SAT NIGHT.
MOISTURE TRAPPED UNDER SUBSIDENCE INVERSION ON SATURDAY WILL
PRODUCE SOME CLOUDS...ESPECIALLY CLOSE TO THE COAST. THIS WILL
ALSO HELP TO LIMIT HEATING. THE COMBINATION OF CAA AND CLOUD
DEVELOPMENT WILL KEEP TEMPS A GOOD 5 TO 10 DEGREES COOLER THAN
PREVIOUS DAYS AND THE DRIER AIR WILL MAKE IT FEEL EVEN COOLER.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...WEAK RIDGING ALOFT AT THE START OF THE PERIOD
WILL SLOWLY BREAK DOWN NEXT WEEK. SURFACE HIGH OVERHEAD ON SUN WILL
YIELD TO A WEAK COLD FRONT MOVING IN FROM THE NORTH LATE MON OR
EARLY TUE. AHEAD OF THE FRONT LIGHT RETURN FLOW AND A BUMP IN LOW
LEVEL MOISTURE COULD PRODUCE ISOLATED SHOWERS MON AFTERNOON...MAINLY
NEAR THE COAST. WILL NOT CARRY A ZERO POP BUT WILL KEEP POP 10 OR
LESS. COOLER AND DRIER HIGH PRESSURE WILL BUILD IN FROM THE NORTH
BEHIND THE FRONT. LIMITED MOISTURE ALONG THE FRONT AND LACK OF
FORCING...INSTABILITY AND MID LEVEL SUPPORT SUGGESTS THE FRONT WILL
BE LITTLE MORE THAN A WIND SHIFT WITH LIMITED CLOUD COVER. HIGH
SLOWLY SHIFTS EAST NEXT WEEK...EVENTUALLY MOVING OFF THE MID
ATLANTIC COAST WED/THU. NORTHERLY FLOW TUE INTO WED WILL KEEP
TEMPERATURES NEAR TO SLIGHTLY BELOW CLIMO AND LIMIT PRECIP CHANCES.
DEVELOPING RETURN FLOW LATE NEXT WEEK LEADS TO A SLIGHT INCREASE IN
MOISTURE. LOW LEVEL MOISTURE IN CONCERT WITH WEAKENING MID LEVEL
SUBSIDENCE MAY ALLOW FOR DEVELOPMENT OF SOME DEEPER CONVECTION. FOR
NOW WILL MAINTAIN INHERITED SILENT POP WED/THU.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...VFR CONDITIONS ARE EXPECTED THIS EVENING WITH SOUTHWEST
WINDS 3-6 KTS. THIS LOW-LEVEL FLOW SHOULD INHIBIT FOG FORMATION...SO
DO NOT ANTICIPATE ANY VSBY RESTRICTIONS OVERNIGHT. AN APPROACHING
COLD FRONT WILL MOVE THROUGH THE CWA EARLY FRIDAY. THE TIMING OF
FROPA IS NOT CONDUCIVE FOR WIDESPREAD SHOWERS...BUT WILL STILL
MENTION VCSH ON FRIDAY MORNING AS HI-RES GUIDANCE HINTS AT SOME
ISOLATED LIGHT SHRA BEFORE 12Z. BY MIDDAY THE FRONT SHOULD BE OFF
THE CAROLINA COAST...AND DRIER MID-LEVEL AIR WILL FILTER INTO OUR
AREA BEHIND THE FRONT. THE WINDS WILL BECOME NORTHWEST AOB 10 KTS
DURING THE DAY FOLLOWING FROPA. THE GFS HINTS AT SOME CONVECTIVE
ACTIVITY ALONG THE COAST FRIDAY AFTN...BUT SUBSIDENCE ALOFT AND AN
INVERSION AROUND 650 MB SHOULD EFFECTIVELY LIMIT STORM DEVELOPMENT.
THEREFORE...WILL ONLY INCLUDE SCT CU FOR THE COASTAL SITES ATTM.
EXTENDED OUTLOOK...VFR WILL PREVAIL THROUGH THE EXTENDED PERIOD.
VERY SLIGHT CHANCE OF SHOWERS LATE MONDAY INTO EARLY TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM THURSDAY...THE SFC PG HAS BEEN SLOW TO TIGHTEN AHEAD
OF THE COLD FRONT. THE LATEST HRRR CONTINUES TO ILLUSTRATE
SUSTAINED WINDS APPROACHING 20 KT OVERNIGHT. WILL NOT GO TO THAT
EXTREME GIVEN THE CURRENT CONDITIONS. AN INCREASE TO SUSTAINED
AROUND 15 KT WILL CONTINUE TO BE ADVERTISED. SFC PRESSURE PATTERN
AHEAD OF THE COLD FRONT TO YIELD A SW DIRECTION THIS EVENING...
BECOMING WSW TOWARD DAYBREAK AS THE FRONT MOVES IN CLOSER
PROXIMITY. SIGNIFICANT SEAS OF 2 TO 3 FT THIS EVENING... WITH A 4
FOOTER POSSIBLE ACROSS THE OUTER WATERS OFF CAPE FEAR DURING THE
PRE-DAWN FRI HOURS. THE 8 TO 9 SECOND PERIOD EASTERLY GROUND SWELL
WILL DOMINATE OVERNIGHT...HOWEVER THERE WILL BE AN INCREASE OF 3
TO 5 SECOND PERIOD WIND WAVES AFTER MIDNIGHT. HENCE...THE POSSIBLE
4 FOOTERS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 PM
THURSDAY...COLD FRONT WILL DROP SOUTHEAST INTO THE WATERS ON
FRIDAY BUT WINDS WILL BACK SOME THROUGH THE DAY AS SEA BREEZE
DEVELOPS. THEN BY NIGHTFALL...WINDS WILL SWING AROUND TO THE
NORTHEAST UP TO 10 TO 15 KTS AS BOUNDARY PUSHES SOUTH. EXPECT A
SURGE OF COOLER AND DRIER AIR ADVECTING IN AS COOL CANADIAN HIGH
PRESSURE BUILDS INTO AREA BEHIND THE FRONT.
EXPECT A SECONDARY PUSH OF COOL AND DRY AIR ON SAT AS MID TO
UPPER TROUGH SWINGS OFF THE COAST AND HIGH PRESSURE CONTINUES TO
BUILD SOUTH PRODUCING A DEEPER DRIER AND COOLER NORTHERLY FLOW.
THIS SECONDARY SURGE SHOULD PRODUCE WINDS UP TO 15 TO 20 KTS WITH
HIGHER GUSTS LATE SATURDAY INTO EARLY SUNDAY. SEAS WILL INCREASE
FROM 2 TO 3 FT EARLY FRI TO 3-5 FEET FRI NIGHT INTO SATURDAY AS
WINDS INCREASE. LATEST WNA MODELS SHOW SEAS PEAKING AROUND 5 FT POSSIBLY
WARRANTING A SCEC HEADLINE...BUT THE SEAS COULD END UP BEING
HIGHER IF SURGE PRODUCES GREATER WINDS IN WELL MIXED ATMOSPHERE
DUE TO WARMER WATERS THIS TIME OF YEAR.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...NORTHEAST FLOW BETWEEN 10 AND 15 KT AT THE
START OF THE PERIOD WILL VEER TO EASTERLY AS HIGH TO THE NORTH
SHIFTS EAST. LITTLE CHANGE TO THE GRADIENT IS EXPECTED AND WINDS ARE
LIKELY TO REMAIN 10 TO 15 KT THROUGH SUN. WEAK EAST TO SOUTHEAST
FLOW DEVELOPS MON AS HIGH MOVES FARTHER OFFSHORE. SPEEDS AROUND 10
KT AND SOUTHERLY COMPONENT WILL BE SHORT LIVED. LATE MON/EARLY TUE A
COLD FRONT MOVES SOUTH ACROSS THE WATERS FOLLOWED BY HIGH PRESSURE
BUILDING IN FROM THE NORTHWEST. NORTH TO NORTHEAST FLOW DEVELOPS
WITH SPEEDS A SOLID 15 KT TUE. SEAS START OUT 3 TO 4 FT BUT DROP TO
2 TO 3 FT FOR MON AS WIND SPEEDS DECREASE. INCREASING NORTHEAST FLOW
MON NIGHT AND TUE WILL PUSH SEAS BACK TO 2 TO 4 FT BY THE END OF THE
PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...DCH/MJC
SHORT TERM...RGZ
LONG TERM...III
AVIATION...MJC/DL
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
344 PM EDT WED SEP 11 2013
.SYNOPSIS...
A WARM AND HUMID AIRMASS WILL REMAIN OVER THE REGION INTO TONIGHT.
A COLD FRONT WILL ARRIVE ACROSS NW OHIO SHORTLY AFTER MIDNIGHT
THEN SWEEP ACROSS THE REGION THROUGH MID MORNING ON THURSDAY.
COOLER AIR WILL SPILL ACROSS THE REGION WITH INCREASING HIGH
PRESSURE. THE HIGH WILL BE EAST OF THE AREA BY SUNDAY MORNING.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
WE HAVE LOCALLY EXPANDED THE WATCH BOX TO COVER THE CURRENT LINE
OF CONVECTION THAT EXTENDS FROM MARION TO MANSFIELD.
TEMPERATURES HAVE WARMED WELL INTO THE 90S ACROSS THE WESTERN HALF
OF THE REGION SO FAR TODAY. THIS HEATING AND SOME CONVERGENCE
ALONG THE COOL POOL FROM EARLY AFTERNOON CONVECTION HAS BEEN
ENOUGH TO TRIGGER THE NEW GROWTH. THE STRONGEST STORMS WILL HAVE
THE CAPABILITY OF PRODUCING STRONG DOWNBURST WINDS. WE SHOULD ALSO
BEGIN TO SEE SOME DEVELOPMENT ACROSS NORTHEAST OHIO INTO NW PA AS
WE WARM A COUPLE MORE DEGREES. STRONG GUSTY WINDS WILL ALSO BE
POSSIBLE WITH THIS CONVECTION.
WE WILL THEN WAIT ON THE COLD FRONT THAT SHOULD MOVE INTO NW OHIO
AFTER MIDNIGHT. THERE COULD BE A FEW ISOLATED THUNDERSTORMS AHEAD
OF THE FRONT BUT WE BELIEVE IT WILL TAKE THE STRONGER FORCING
ALONG THE FRONT TO PRODUCE MOST OF THE OVERNIGHT ACTIVITY.
IT WILL BE ANOTHER WARM AND HUMID NIGHT FOR THE REGION. NW OHIO
WILL COOL IN THE WAKE OF THE FRONT BUT IT WILL BE LATE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY NIGHT/...
THE COLD FRONT WILL BE MOVING ACROSS THE REGION THROUGH THE MORNING
WITH SHOWERS AND SOME SCATTERED THUNDER EXPECTED NEAR AND AHEAD OF
THE FRONT. THERE WILL BE A LULL IN THE SHOWERS FOR A FEW HOURS
THURSDAY AFTERNOON INTO THE EVENING. AS THE COOLER AIR SPILLS INTO
THE AREA THURSDAY NIGHT AND AN UPPER LEVEL TROUGH PASSES WE SHOULD
SEE AN INCREASE IN LAKE EFFECT SHOWERS. THESE LAKE EFFECT SHOWERS
WILL CONTINUE INTO FRIDAY AND MAY END BY EARLY SATURDAY MORNING.
DAYTIME HIGHS ON THURSDAY WILL BE IN THE MORNING AND MAY HOLD
STEADY OR DROP SLIGHTLY THROUGH THE AFTERNOON. MUCH COOLER FRIDAY
INTO SATURDAY WITH HIGHS LIKELY REMAINING IN THE 60S. A FEW
LOCATIONS MAY STAY IN THE 50S ACROSS NW PA ON FRIDAY.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE MODELS INDICATE ANOTHER COLD FRONT THAT MOVES SE ACROSS THE AREA
EARLY SUN NIGHT. MOISTURE SOMEWHAT LIMITED SO WILL ONLY CARRY A
CHANCE POP FOR SHRA WITH THE FRONTAL PASSAGE. WINDS TURN BACK TO THE
NORTH FOR MON BRINGING DRIER AND COOLER AIR BACK INTO THE AREA.
THERE COULD BE A LINGERING SHRA IN THE SE IN THE MORNING...OTHERWISE
SHOULD SEE DRY CONDITIONS TAKE OVER AND HOLD ON UNTIL TUE NIGHT OR
WED WHEN A WARM FRONT MAY BE LIFTING NEAR THE AREA ALONG WITH
INCREASING MOISTURE. THE MODELS DIFFER BY WED ON HOW MUCH MOISTURE
MAKES ITS WAY BACK INTO THE AREA SO WILL ONLY CARRY A SLIGHT CHANCE
POP FOR NOW.
TEMPS SHOULD BE NEAR NORMAL FOR SUN THEN DROP BACK BELOW NORMAL MON
AND TUE BEFORE MODERATING BACK TO NEAR NORMAL BY WED.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
MID LEVEL CLOUD HAD BEEN HELPING TO KEEP TSRA FROM DEVELOPING.
BASED ON LATEST MODEL RUNS AND RADAR DATA...STILL EXPECT SCT TSRA
OVER MAINLY THE SE THIRD OF THE AREA THIS AFTERNOON. HRRR AND RUC
STILL INDECISIVE ON TIME AND LOCATION OF POTENTIAL TSRA REST OF
TODAY...THUS DON`T HAVE MUCH CONFIDENCE IN ANYTHING AT ANY TAF
SITES THRU 00Z SO WILL LIKELY JUST MENTION VCTS UNLESS SOMETHING
LOOKS IMMINENT AT TAF ISSUE TIME.
OUTSIDE OF ANY SHRA/TSRA...SHOULD SEE VFR/HIGH END MVFR TEND TO
PREVAIL AT MOST SITES UNTIL LATE TONIGHT AND FRI MORNING WHEN PRECIP
SHOULD BECOME MORE WIDESPREAD THEN WINDS START TO TURN NW TO ALLOW
LOWER CLOUDS TO MOVE IN OFF OF LAKE ERIE.
OUTLOOK...WILL LIKELY HAVE NON VFR CEILINGS ACROSS NE OH/NW PA LATE
THURSDAY THROUGH FRIDAY.
&&
.MARINE...
MODELS STILL INDICATE A SW FLOW AT ABOUT 10 TO 20 KNOTS TONIGHT
UNTIL A COLD FRONT DROPS ACROSS THE LAKE AROUND DAYBREAK THU TO
SHIFT THE FLOW TO NNW. THE PRESSURE GRADIENT TIGHTENS BY LATER THU
SO WINDS SHOULD PICK UP TO 15 TO 20 KNOTS AND MAYBE 15 TO 25 KNOTS.
WAVES WILL BUILD TO 4 TO 6 FEET SO A SCA WILL BE NEEDED AND WILL
LIKELY LAST UNTIL LATE FRI NIGHT WHEN HIGH PRESSURE FINALLY BUILDS
INTO THE LAKE TO DIMINISH THE FLOW.
THE HIGH WILL PRODUCE LIGHT AND CHANGEABLE FLOW SAT INTO SAT NIGHT
THEN WINDS LINE UP OUT OF THE SW FOR SUN AND LOOK TO INCREASE TO 10
TO 15 KNOTS. ANOTHER COLD FRONT WILL MOVE ACROSS THE LAKE LATER SUN
OR SUN NIGHT TO SHIFT THE FLOW BACK TO NORTH FOR MON AND MAY PRODUCE
NEAR SCA CONDITIONS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MULLEN
NEAR TERM...MULLEN
SHORT TERM...MULLEN
LONG TERM...ADAMS
AVIATION...ADAMS
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
101 PM EDT WED SEP 11 2013
.SYNOPSIS...
A COLD FRONT LOCATED FROM NORTHERN MICHIGAN TO EASTERN IOWA THIS
MORNING WILL MOVE SOUTH TODAY...REACHING NORTHERN OH/NW PA
THURSDAY MORNING. A SECONDARY TROUGH WILL MOVE THROUGH THURSDAY
AFTERNOON. A SIGNIFICANT AIRMASS CHANGE WILL TAKE PLACE...WITH
TEMPERATURES TURNING FROM ABOVE NORMAL HEAT TO A BELOW NORMAL
CHILL FOR FRIDAY INTO THE WEEKEND. HIGH PRESSURE WILL BE OVER THE
REGION SATURDAY AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAVE GONE WITH SCATTERED THUNDERSTORMS ACROSS THE AREA FOR THE
AFTERNOON. THE BEST CHANCES LOOK TO BE ACROSS THE EASTERN THIRD OF
THE REGION. WE WILL THEN WATCH FOR ADDITIONAL CONVECTION TO MOVE
INTO THE WEST DURING THE EVENING HOURS.
THE SEVERE POTENTIAL HAS INCREASED SLIGHTLY ACROSS THE EASTERN
THIRD OF THE REGION WHERE DEEPER MOISTURE AND SOME WEAK MIDDLE
LEVEL FORCING SEEMS TO EXIST. THIS FORCING IS EVIDENT BY THE
MORNING SHOWERS/THUNDERSTORMS THAT DEVELOPED NEAR AND EAST OF A
LINE FROM ERIE TO DAYTON. AS WE HEAT A BIT MORE THIS AFTERNOON
THE THREAT OF STRONG DAMAGING WINDS WILL INCREASE.
PREVIOUS DISCUSSION...
A NUMBER OF ITEMS TO CONSIDER FOR TODAY. STRONG RIDGE OVER THE
OHIO VALLEY WILL BEGIN TO BREAK DOWN. A FRONTAL SYSTEM OVER THE
CENTRAL GREAT LAKES WILL BEGIN TO MAKE PROGRESS SOUTH...ALTHOUGH
SLOW AT FIRST. ONE INITIAL SHORTWAVE SHEARS OFF TO NEW ENGLAND
BRINGING THE FRONT INTO CENTRAL LOWER MI FOR THIS AFTERNOON. A
STRONGER SHORTWAVE COMING OUT OF SOUTH CENTRAL CANADA WILL CARVE
OUT THE TROUGH FOR THE GREAT LAKES AND GIVE THAT FRONT A PUSH
SOUTH OVERNIGHT. FIRST QUESTION BECOMES HOW MUCH IN THE WAY OF
SHOWERS/STORMS DO WE GET BEFORE 6P. AN AREA OF DEEPER MOISTURE
THAT 24 HRS AGO WAS NEAR PADUCAH IS NOW ACROSS SOUTHWEST OHIO.
MODEL GUIDANCE SHOWERS THAT A FEW SHOWERS/TS INITIATE WITH THIS
ACROSS OUR SOUTHEAST COUNTIES INCLUDING YOUNGSTOWN AND
AKRON/CANTON. HAVE FOCUSED SOME AFTERNOON PRECIP CHANCES THERE.
ALSO A LITTLE CONCERNED WITH AREA FROM FINDLAY TO MANSFIELD FOR AN
ISOLATED STORM. FINALLY SOME PREFRONTAL ACTIVITY IS POSSIBLE
ACROSS SE MI AND THEREFORE ALSO THE TOLEDO AREA. SPC SLIGHT RISK
IS ACROSS THE NORTHERN HALF OF THE AREA FOR STORMS LATE THIS
AFTERNOON AND EVENING. AGREE WITH THAT. NEXT QUESTION IS
TEMPERATURES. THE ONLY THING SAVING US FROM A REPEAT OF YESTERDAY
IS THE PRESENCE OF ADDITIONAL CLOUD COVER. THIS MAY BE JUST ENOUGH
TO KEEP US OUT OF HEAT ADVISORY TERRITORY. UPPER 80S ACROSS THE
SOUTHEAST TO LOWER 90S ACROSS THE I-75 CORRIDOR.
ONLY MINOR SKY COVER ADJUSTMENTS WERE MADE WITH THIS EARLY MORNING
UPDATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
SO STRONGER SHORTWAVE THAT WILL AMPLIFY THE TROUGH ACROSS THE
GREAT LAKES WILL PUSH THE COLD FRONT SOUTH TONIGHT. AT 6 PM STORMS
MAY BE ONGOING ACROSS FAR NW OH OR BE CLOSE BY. SOME CONCERN FOR
SEVERE STORMS ESPECIALLY ACROSS THE LAKESHORE COUNTIES. WIND WOULD
BE THE PRIMARY THREAT. AREA WILL BECOME MODESTLY UNSTABLE AND
SHEAR WILL BEGIN TO INCREASE AS THE UPPER TROUGH APPROACHES. WILL
JUST HAVE TO WATCH FRONTAL TIMING AND ANY PREFRONTAL AREAS OF
CONVERGENCE. MARCH LIKELY AND CATEGORICAL PRECIP CHANCES SOUTHWARD
OVER THE COURSE OF THE NIGHT AND INTO THURSDAY MORNING.
CONTINUED PRECIPITATION CHANCES INTO MUCH OF THURSDAY. THERE ARE
INDICATIONS OF A SECONDARY TROUGH THAT MAY AID IN A FEW ADDITIONAL
SHOWERS/TS. THE COLD PUSH WITH THIS SYSTEM IS SLIGHTLY
DELAYED...AND IS ASSOCIATED MORE WITH THE SECONDARY TROUGH. SO
THURSDAY WILL TURN OUT NEAR NORMAL FOR HIGHS. THE BIG CHANGE COMES
FOR FRIDAY.
WHILE THERE MAY BE A LULL IN PRECIPITATION THURSDAY EVENING...AS
THE COLDER AIR FILTERS IN AND THE UPPER TROUGH APPROACHES...LAKE
EFFECT CONDITIONS BEGIN TO TAKE SHAPE. SCATTERED SHOWERS STARTING
LATE THURSDAY NIGHT AND CONTINUING INTO FRIDAY POSSIBLE. HAVE
RAISED POPS ACROSS NRN OH/NW PA. ALSO HAVE ADDED THE MENTION OF
ISOLATED THUNDER FOR EAST OF CLEVELAND. LAKE TO H5 TEMPERATURE
DIFFERENCE GREAT ENOUGH FOR THE POSSIBILITY OF THUNDER WITHIN THE
LAKE EFFECT SHOWERS. TEMPERATURES FRIDAY WILL STRUGGLE TO GET INTO
THE 60S...WITH SOME PARTS OF NW PA/FAR NE OH STAYING IN THE UPPER
50S.
LAKE EFFECT SHOWERS SHOULD BE CONFINED TO FRIDAY AND MAYBE FRIDAY
NIGHT. AFTER THAT RIDGING AND DRYING BEGIN TO WORK INTO THE AREA
ENDING THAT THREAT. TEMPS FRIDAY NIGHT TO BE IN THE 40S. WITH
CLEARING ACROSS THE WEST TEMPS WILL BE CLOSER TO 40. SATURDAY
HIGHS SIMILAR..60 TO 65. BY SATURDAY NIGHT MORE OF THE AREA WILL
BE CLEARER AND MORE LOWER 40S ARE EXPECTED. IT IS DEFINITELY
POSSIBLE TO GET UPPER 30S DEPENDING ON CLOUD COVER.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
THIS PORTION OF THE EXTENDED DOES NOT LOOK VERY ACTIVE. HIGH
PRESSURE WILL BE MOVING EAST ON SUNDAY AND THAT WILL ALLOW A COLD
FRONT TO MOVE IN SUNDAY NIGHT INTO MONDAY BEFORE HIGH PRESSURE
BUILDS BACK IN. THE 00Z GFS AND ECMWF NOW AGREE WITH THIS SOLUTION.
AT THIS TIME KEPT THE POPS AROUND 20%. THIS MAY HAVE TO BE RAISED
SOME IF THE TREND REMAINS THE SAME. KEPT CLOSE TO HPC GUIDANCE FOR
THE TEMPERATURE FORECAST WHICH HAS SLIGHTLY BELOW NORMAL
TEMPERATURES.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
MID LEVEL CLOUD HAD BEEN HELPING TO KEEP TSRA FROM DEVELOPING. BASED
ON LATEST MODEL RUNS AND RADAR DATA...STILL EXPECT SCT TSRA OVER
MAINLY THE SE THIRD OF THE AREA THIS AFTERNOON. HRRR AND RUC STILL
INDECISIVE ON TIME AND LOCATION OF POTENTIAL TSRA REST OF
TODAY...THUS DON`T HAVE MUCH CONFIDENCE IN ANYTHING AT ANY TAF SITES
THRU 00Z SO WILL LIKELY JUST MENTION VCTS UNLESS SOMETHING LOOKS
IMMINENT AT TAF ISSUE TIME.
OUTSIDE OF ANY SHRA/TSRA...SHOULD SEE VFR/HIGH END MVFR TEND TO
PREVAIL AT MOST SITES UNTIL LATE TONIGHT AND FRI MORNING WHEN PRECIP
SHOULD BECOME MORE WIDESPREAD THEN WINDS START TO TURN NW TO ALLOW
LOWER CLOUDS TO MOVE IN OFF OF LAKE ERIE.
OUTLOOK...WILL LIKELY HAVE NON VFR CEILINGS ACROSS NE OH/NW PA LATE
THURSDAY THROUGH FRIDAY.
&&
.MARINE...
SOME ACTIVE WEATHER FOR THE LAKE WILL BEGIN ESPECIALLY TONIGHT AND
LAST INTO FRIDAY. SOUTHWEST WINDS ON THE LAKE TODAY WILL STAY BELOW
SMALL CRAFT ADVISORY CONDITIONS EVEN ON THE EAST END. THE COLD FRONT
WILL MOVE ACROSS THE LAKE LATE TONIGHT AND EARLY THURSDAY MORNING.
SOME OF THE THUNDERSTORMS AHEAD OF THE FRONT WILL LIKELY PROMPT
SPECIAL MARINE WARNINGS TO BE ISSUED.
SOME QUESTION HOW QUICKLY THE WINDS WILL PICK UP ON THE LAKE
THURSDAY BEHIND THE COLD FRONT. WENT TOWARD THE FASTER GFS IN
INCREASING THE WINDS ESPECIALLY ON THE EAST END AND THEN THE WEST
END THURSDAY NIGHT. EVENTUALLY A SMALL CRAFT ADVISORY WILL BE NEEDED
ON MUCH OF LAKE ERIE. THE THREAT FOR A SMALL CRAFT ADVISORY
CONDITIONS WILL LAST INTO FRIDAY NIGHT. PLENTY OF COLD AIR WILL BE
FLOWING ACROSS THE LAKE AND THAT MAY GENERATE SOME WATERSPOUTS AND
THUNDER BESIDES THE SHOWERS ESPECIALLY ON FRIDAY AS THE LAKE AND 850
MB TEMPERATURE DIFFERENCE WILL BE NEAR 20C AND THE LAKE AND 500 MB
TEMPERATURE DIFFERENCE WILL BE AROUND 40C.
HIGH PRESSURE WILL BUILD OVER THE LAKE ON SATURDAY AND THEN MOVE
EAST ON SUNDAY ALLOWING THE SOUTHWEST FLOW TO RETURN. A FRONT WILL
CROSS THE LAKE SUNDAY NIGHT INTO MONDAY SHIFTING THE WINDS TO
ONSHORE AS THE HIGH WILL TRY TO BUILD IN. THE WINDS AND WAVES ARE
EXPECTED TO BE BELOW SMALL CRAFT ADVISORY CONDITIONS EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...MULLEN/OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...KIELTYKA
AVIATION...ADAMS
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1214 PM EDT WED SEP 11 2013
.SYNOPSIS...
A COLD FRONT LOCATED FROM NORTHERN MICHIGAN TO EASTERN IOWA THIS
MORNING WILL MOVE SOUTH TODAY...REACHING NORTHERN OH/NW PA
THURSDAY MORNING. A SECONDARY TROUGH WILL MOVE THROUGH THURSDAY
AFTERNOON. A SIGNIFICANT AIRMASS CHANGE WILL TAKE PLACE...WITH
TEMPERATURES TURNING FROM ABOVE NORMAL HEAT TO A BELOW NORMAL
CHILL FOR FRIDAY INTO THE WEEKEND. HIGH PRESSURE WILL BE OVER THE
REGION SATURDAY AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HAVE GONE WITH SCATTERED THUNDERSTORMS ACROSS THE AREA FOR THE
AFTERNOON. THE BEST CHANCES LOOK TO BE ACROSS THE EASTERN THIRD OF
THE REGION. WE WILL THEN WATCH FOR ADDITIONAL CONVECTION TO MOVE
INTO THE WEST DURING THE EVENING HOURS.
THE SEVERE POTENTIAL HAS INCREASED SLIGHTLY ACROSS THE EASTERN
THIRD OF THE REGION WHERE DEEPER MOISTURE AND SOME WEAK MIDDLE
LEVEL FORCING SEEMS TO EXIST. THIS FORCING IS EVIDENT BY THE
MORNING SHOWERS/THUNDERSTORMS THAT DEVELOPED NEAR AND EAST OF A
LINE FROM ERIE TO DAYTON. AS WE HEAT A BIT MORE THIS AFTERNOON
THE THREAT OF STRONG DAMAGING WINDS WILL INCREASE.
PREVIOUS DISCUSSION...
A NUMBER OF ITEMS TO CONSIDER FOR TODAY. STRONG RIDGE OVER THE
OHIO VALLEY WILL BEGIN TO BREAK DOWN. A FRONTAL SYSTEM OVER THE
CENTRAL GREAT LAKES WILL BEGIN TO MAKE PROGRESS SOUTH...ALTHOUGH
SLOW AT FIRST. ONE INITIAL SHORTWAVE SHEARS OFF TO NEW ENGLAND
BRINGING THE FRONT INTO CENTRAL LOWER MI FOR THIS AFTERNOON. A
STRONGER SHORTWAVE COMING OUT OF SOUTH CENTRAL CANADA WILL CARVE
OUT THE TROUGH FOR THE GREAT LAKES AND GIVE THAT FRONT A PUSH
SOUTH OVERNIGHT. FIRST QUESTION BECOMES HOW MUCH IN THE WAY OF
SHOWERS/STORMS DO WE GET BEFORE 6P. AN AREA OF DEEPER MOISTURE
THAT 24 HRS AGO WAS NEAR PADUCAH IS NOW ACROSS SOUTHWEST OHIO.
MODEL GUIDANCE SHOWERS THAT A FEW SHOWERS/TS INITIATE WITH THIS
ACROSS OUR SOUTHEAST COUNTIES INCLUDING YOUNGSTOWN AND
AKRON/CANTON. HAVE FOCUSED SOME AFTERNOON PRECIP CHANCES THERE.
ALSO A LITTLE CONCERNED WITH AREA FROM FINDLAY TO MANSFIELD FOR AN
ISOLATED STORM. FINALLY SOME PREFRONTAL ACTIVITY IS POSSIBLE
ACROSS SE MI AND THEREFORE ALSO THE TOLEDO AREA. SPC SLIGHT RISK
IS ACROSS THE NORTHERN HALF OF THE AREA FOR STORMS LATE THIS
AFTERNOON AND EVENING. AGREE WITH THAT. NEXT QUESTION IS
TEMPERATURES. THE ONLY THING SAVING US FROM A REPEAT OF YESTERDAY
IS THE PRESENCE OF ADDITIONAL CLOUD COVER. THIS MAY BE JUST ENOUGH
TO KEEP US OUT OF HEAT ADVISORY TERRITORY. UPPER 80S ACROSS THE
SOUTHEAST TO LOWER 90S ACROSS THE I-75 CORRIDOR.
ONLY MINOR SKY COVER ADJUSTMENTS WERE MADE WITH THIS EARLY MORNING
UPDATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
SO STRONGER SHORTWAVE THAT WILL AMPLIFY THE TROUGH ACROSS THE
GREAT LAKES WILL PUSH THE COLD FRONT SOUTH TONIGHT. AT 6 PM STORMS
MAY BE ONGOING ACROSS FAR NW OH OR BE CLOSE BY. SOME CONCERN FOR
SEVERE STORMS ESPECIALLY ACROSS THE LAKESHORE COUNTIES. WIND WOULD
BE THE PRIMARY THREAT. AREA WILL BECOME MODESTLY UNSTABLE AND
SHEAR WILL BEGIN TO INCREASE AS THE UPPER TROUGH APPROACHES. WILL
JUST HAVE TO WATCH FRONTAL TIMING AND ANY PREFRONTAL AREAS OF
CONVERGENCE. MARCH LIKELY AND CATEGORICAL PRECIP CHANCES SOUTHWARD
OVER THE COURSE OF THE NIGHT AND INTO THURSDAY MORNING.
CONTINUED PRECIPITATION CHANCES INTO MUCH OF THURSDAY. THERE ARE
INDICATIONS OF A SECONDARY TROUGH THAT MAY AID IN A FEW ADDITIONAL
SHOWERS/TS. THE COLD PUSH WITH THIS SYSTEM IS SLIGHTLY
DELAYED...AND IS ASSOCIATED MORE WITH THE SECONDARY TROUGH. SO
THURSDAY WILL TURN OUT NEAR NORMAL FOR HIGHS. THE BIG CHANGE COMES
FOR FRIDAY.
WHILE THERE MAY BE A LULL IN PRECIPITATION THURSDAY EVENING...AS
THE COLDER AIR FILTERS IN AND THE UPPER TROUGH APPROACHES...LAKE
EFFECT CONDITIONS BEGIN TO TAKE SHAPE. SCATTERED SHOWERS STARTING
LATE THURSDAY NIGHT AND CONTINUING INTO FRIDAY POSSIBLE. HAVE
RAISED POPS ACROSS NRN OH/NW PA. ALSO HAVE ADDED THE MENTION OF
ISOLATED THUNDER FOR EAST OF CLEVELAND. LAKE TO H5 TEMPERATURE
DIFFERENCE GREAT ENOUGH FOR THE POSSIBILITY OF THUNDER WITHIN THE
LAKE EFFECT SHOWERS. TEMPERATURES FRIDAY WILL STRUGGLE TO GET INTO
THE 60S...WITH SOME PARTS OF NW PA/FAR NE OH STAYING IN THE UPPER
50S.
LAKE EFFECT SHOWERS SHOULD BE CONFINED TO FRIDAY AND MAYBE FRIDAY
NIGHT. AFTER THAT RIDGING AND DRYING BEGIN TO WORK INTO THE AREA
ENDING THAT THREAT. TEMPS FRIDAY NIGHT TO BE IN THE 40S. WITH
CLEARING ACROSS THE WEST TEMPS WILL BE CLOSER TO 40. SATURDAY
HIGHS SIMILAR..60 TO 65. BY SATURDAY NIGHT MORE OF THE AREA WILL
BE CLEARER AND MORE LOWER 40S ARE EXPECTED. IT IS DEFINITELY
POSSIBLE TO GET UPPER 30S DEPENDING ON CLOUD COVER.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
THIS PORTION OF THE EXTENDED DOES NOT LOOK VERY ACTIVE. HIGH
PRESSURE WILL BE MOVING EAST ON SUNDAY AND THAT WILL ALLOW A COLD
FRONT TO MOVE IN SUNDAY NIGHT INTO MONDAY BEFORE HIGH PRESSURE
BUILDS BACK IN. THE 00Z GFS AND ECMWF NOW AGREE WITH THIS SOLUTION.
AT THIS TIME KEPT THE POPS AROUND 20%. THIS MAY HAVE TO BE RAISED
SOME IF THE TREND REMAINS THE SAME. KEPT CLOSE TO HPC GUIDANCE FOR
THE TEMPERATURE FORECAST WHICH HAS SLIGHTLY BELOW NORMAL TEMPERATURES.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
THE BIG QUESTION IS THE TIMING OF THE THUNDERSTORMS FOR TODAY AND
TONIGHT. IN THE MEANTIME INCREASING MID AND HIGH CLOUDS FOR THE
MORNING. ANY FOG WILL DISSIPATE BY MID MORNING BUT SOME HAZE COULD
CONTINUE INTO THE AFTERNOON.
THE MODELS ARE FAIRLY CONSISTENT IN INCREASING THE LOW LEVEL
MOISTURE BY MID TO LATE MORNING OVER NE OH AND NW PA AND THEN
DEVELOPING SCATTERED SHOWERS AND THUNDERSTORMS. THIS IS OK...EVEN
THOUGH THE HRRR MODEL HAS BACKED DOWN ON THIS. AT THIS TIME JUST KEPT
IT THUNDER VICINITY. A LITTLE BREAK MAY OCCUR EARLY THIS EVENING
OVER NE OH AND NW PA WITH SCATTERED SHOWERS AND THUNDERSTORMS
DEVELOPING OVER NW OH AND SPREADING EAST AND THEN A BETTER CHANCE
OF SHOWERS AND THUNDERSTORMS AFTER MIDNIGHT AS THE FRONT
APPROACHES.
OUTLOOK...WILL LIKELY HAVE NON VFR CEILINGS ACROSS NE OH/NW PA
THURSDAY THROUGH FRIDAY.
&&
.MARINE...
SOME ACTIVE WEATHER FOR THE LAKE WILL BEGIN ESPECIALLY TONIGHT AND
LAST INTO FRIDAY. SOUTHWEST WINDS ON THE LAKE TODAY WILL STAY BELOW
SMALL CRAFT ADVISORY CONDITIONS EVEN ON THE EAST END. THE COLD FRONT
WILL MOVE ACROSS THE LAKE LATE TONIGHT AND EARLY THURSDAY MORNING.
SOME OF THE THUNDERSTORMS AHEAD OF THE FRONT WILL LIKELY PROMPT
SPECIAL MARINE WARNINGS TO BE ISSUED.
SOME QUESTION HOW QUICKLY THE WINDS WILL PICK UP ON THE LAKE
THURSDAY BEHIND THE COLD FRONT. WENT TOWARD THE FASTER GFS IN
INCREASING THE WINDS ESPECIALLY ON THE EAST END AND THEN THE WEST
END THURSDAY NIGHT. EVENTUALLY A SMALL CRAFT ADVISORY WILL BE NEEDED
ON MUCH OF LAKE ERIE. THE THREAT FOR A SMALL CRAFT ADVISORY
CONDITIONS WILL LAST INTO FRIDAY NIGHT. PLENTY OF COLD AIR WILL BE
FLOWING ACROSS THE LAKE AND THAT MAY GENERATE SOME WATERSPOUTS AND
THUNDER BESIDES THE SHOWERS ESPECIALLY ON FRIDAY AS THE LAKE AND 850
MB TEMPERATURE DIFFERENCE WILL BE NEAR 20C AND THE LAKE AND 500 MB
TEMPERATURE DIFFERENCE WILL BE AROUND 40C.
HIGH PRESSURE WILL BUILD OVER THE LAKE ON SATURDAY AND THEN MOVE
EAST ON SUNDAY ALLOWING THE SOUTHWEST FLOW TO RETURN. A FRONT WILL
CROSS THE LAKE SUNDAY NIGHT INTO MONDAY SHIFTING THE WINDS TO
ONSHORE AS THE HIGH WILL TRY TO BUILD IN. THE WINDS AND WAVES ARE
EXPECTED TO BE BELOW SMALL CRAFT ADVISORY CONDITIONS EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...MULLEN/OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
936 AM EDT WED SEP 11 2013
.SYNOPSIS...
A COLD FRONT LOCATED FROM NORTHERN MICHIGAN TO EASTERN IOWA THIS
MORNING WILL MOVE SOUTH TODAY...REACHING NORTHERN OH/NW PA
THURSDAY MORNING. A SECONDARY TROUGH WILL MOVE THROUGH THURSDAY
AFTERNOON. A SIGNIFICANT AIRMASS CHANGE WILL TAKE PLACE...WITH
TEMPERATURES TURNING FROM ABOVE NORMAL HEAT TO A BELOW NORMAL
CHILL FOR FRIDAY INTO THE WEEKEND. HIGH PRESSURE WILL BE OVER THE
REGION SATURDAY AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ONLY MINOR CHANGES WITH THE GRIDS. PLENTY OF LOW LEVEL MOISTURE
OVER THE REGION THIS MORNING. HOWEVER IT APPEARS WE WILL BE ABLE
TO MIX SOME OF IT OUT THROUGH THE AFTERNOON WHICH SHOULD KEEP HEAT
INDEX VALUES BELOW ADVISORY LEVELS. CLOUD COVER HAS ALSO INCREASED
WHICH MAY ALSO SHAVE 2 TO 5 DEGREES FROM HIGHS COMPARED TO
YESTERDAY.
WE WILL HAVE TO MONITOR LOW LEVEL CONVERGENCE THIS AFTERNOON TO
SEE WHERE THE THUNDERSTORMS WILL INITIATE. MOST LIKELY WILL BE
LOCALLY INDUCED CONVERGENCE IN THE VICINITY OF THE HILLS ACROSS
THE CENTRAL HIGHLANDS AND FROM EXTREME NORTHEASTERN OHIO INTO NW
PA. THESE WILL LIKELY REMAIN ISOLATED. WE WILL HAVE TO MONITOR
ANYTHING THAT DEVELOPS SINCE CAPES WILL BE HIGH. SO THE STRONGEST
STORMS WILL HAVE THE CAPABILITY TO PRODUCE STRONG WIND GUSTS AND
MARGINALLY SEVERE HAIL.
PREVIOUS DISCUSSION...
A NUMBER OF ITEMS TO CONSIDER FOR TODAY. STRONG RIDGE OVER THE
OHIO VALLEY WILL BEGIN TO BREAK DOWN. A FRONTAL SYSTEM OVER THE
CENTRAL GREAT LAKES WILL BEGIN TO MAKE PROGRESS SOUTH...ALTHOUGH
SLOW AT FIRST. ONE INITIAL SHORTWAVE SHEARS OFF TO NEW ENGLAND
BRINGING THE FRONT INTO CENTRAL LOWER MI FOR THIS AFTERNOON. A
STRONGER SHORTWAVE COMING OUT OF SOUTH CENTRAL CANADA WILL CARVE
OUT THE TROUGH FOR THE GREAT LAKES AND GIVE THAT FRONT A PUSH
SOUTH OVERNIGHT. FIRST QUESTION BECOMES HOW MUCH IN THE WAY OF
SHOWERS/STORMS DO WE GET BEFORE 6P. AN AREA OF DEEPER MOISTURE
THAT 24 HRS AGO WAS NEAR PADUCAH IS NOW ACROSS SOUTHWEST OHIO.
MODEL GUIDANCE SHOWERS THAT A FEW SHOWERS/TS INITIATE WITH THIS
ACROSS OUR SOUTHEAST COUNTIES INCLUDING YOUNGSTOWN AND
AKRON/CANTON. HAVE FOCUSED SOME AFTERNOON PRECIP CHANCES THERE.
ALSO A LITTLE CONCERNED WITH AREA FROM FINDLAY TO MANSFIELD FOR AN
ISOLATED STORM. FINALLY SOME PREFRONTAL ACTIVITY IS POSSIBLE
ACROSS SE MI AND THEREFORE ALSO THE TOLEDO AREA. SPC SLIGHT RISK
IS ACROSS THE NORTHERN HALF OF THE AREA FOR STORMS LATE THIS
AFTERNOON AND EVENING. AGREE WITH THAT. NEXT QUESTION IS
TEMPERATURES. THE ONLY THING SAVING US FROM A REPEAT OF YESTERDAY
IS THE PRESENCE OF ADDITIONAL CLOUD COVER. THIS MAY BE JUST ENOUGH
TO KEEP US OUT OF HEAT ADVISORY TERRITORY. UPPER 80S ACROSS THE
SOUTHEAST TO LOWER 90S ACROSS THE I-75 CORRIDOR.
ONLY MINOR SKY COVER ADJUSTMENTS WERE MADE WITH THIS EARLY MORNING
UPDATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
SO STRONGER SHORTWAVE THAT WILL AMPLIFY THE TROUGH ACROSS THE
GREAT LAKES WILL PUSH THE COLD FRONT SOUTH TONIGHT. AT 6 PM STORMS
MAY BE ONGOING ACROSS FAR NW OH OR BE CLOSE BY. SOME CONCERN FOR
SEVERE STORMS ESPECIALLY ACROSS THE LAKESHORE COUNTIES. WIND WOULD
BE THE PRIMARY THREAT. AREA WILL BECOME MODESTLY UNSTABLE AND
SHEAR WILL BEGIN TO INCREASE AS THE UPPER TROUGH APPROACHES. WILL
JUST HAVE TO WATCH FRONTAL TIMING AND ANY PREFRONTAL AREAS OF
CONVERGENCE. MARCH LIKELY AND CATEGORICAL PRECIP CHANCES SOUTHWARD
OVER THE COURSE OF THE NIGHT AND INTO THURSDAY MORNING.
CONTINUED PRECIPITATION CHANCES INTO MUCH OF THURSDAY. THERE ARE
INDICATIONS OF A SECONDARY TROUGH THAT MAY AID IN A FEW ADDITIONAL
SHOWERS/TS. THE COLD PUSH WITH THIS SYSTEM IS SLIGHTLY
DELAYED...AND IS ASSOCIATED MORE WITH THE SECONDARY TROUGH. SO
THURSDAY WILL TURN OUT NEAR NORMAL FOR HIGHS. THE BIG CHANGE COMES
FOR FRIDAY.
WHILE THERE MAY BE A LULL IN PRECIPITATION THURSDAY EVENING...AS
THE COLDER AIR FILTERS IN AND THE UPPER TROUGH APPROACHES...LAKE
EFFECT CONDITIONS BEGIN TO TAKE SHAPE. SCATTERED SHOWERS STARTING
LATE THURSDAY NIGHT AND CONTINUING INTO FRIDAY POSSIBLE. HAVE
RAISED POPS ACROSS NRN OH/NW PA. ALSO HAVE ADDED THE MENTION OF
ISOLATED THUNDER FOR EAST OF CLEVELAND. LAKE TO H5 TEMPERATURE
DIFFERENCE GREAT ENOUGH FOR THE POSSIBILITY OF THUNDER WITHIN THE
LAKE EFFECT SHOWERS. TEMPERATURES FRIDAY WILL STRUGGLE TO GET INTO
THE 60S...WITH SOME PARTS OF NW PA/FAR NE OH STAYING IN THE UPPER
50S.
LAKE EFFECT SHOWERS SHOULD BE CONFINED TO FRIDAY AND MAYBE FRIDAY
NIGHT. AFTER THAT RIDGING AND DRYING BEGIN TO WORK INTO THE AREA
ENDING THAT THREAT. TEMPS FRIDAY NIGHT TO BE IN THE 40S. WITH
CLEARING ACROSS THE WEST TEMPS WILL BE CLOSER TO 40. SATURDAY
HIGHS SIMILAR..60 TO 65. BY SATURDAY NIGHT MORE OF THE AREA WILL
BE CLEARER AND MORE LOWER 40S ARE EXPECTED. IT IS DEFINITELY
POSSIBLE TO GET UPPER 30S DEPENDING ON CLOUD COVER.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
THIS PORTION OF THE EXTENDED DOES NOT LOOK VERY ACTIVE. HIGH
PRESSURE WILL BE MOVING EAST ON SUNDAY AND THAT WILL ALLOW A COLD
FRONT TO MOVE IN SUNDAY NIGHT INTO MONDAY BEFORE HIGH PRESSURE
BUILDS BACK IN. THE 00Z GFS AND ECMWF NOW AGREE WITH THIS SOLUTION.
AT THIS TIME KEPT THE POPS AROUND 20%. THIS MAY HAVE TO BE RAISED
SOME IF THE TREND REMAINS THE SAME. KEPT CLOSE TO HPC GUIDANCE FOR
THE TEMPERATURE FORECAST WHICH HAS SLIGHTLY BELOW NORMAL TEMPERATURES.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
THE BIG QUESTION IS THE TIMING OF THE THUNDERSTORMS FOR TODAY AND
TONIGHT. IN THE MEANTIME INCREASING MID AND HIGH CLOUDS FOR THE
MORNING. ANY FOG WILL DISSIPATE BY MID MORNING BUT SOME HAZE COULD
CONTINUE INTO THE AFTERNOON.
THE MODELS ARE FAIRLY CONSISTENT IN INCREASING THE LOW LEVEL
MOISTURE BY MID TO LATE MORNING OVER NE OH AND NW PA AND THEN
DEVELOPING SCATTERED SHOWERS AND THUNDERSTORMS. THIS IS OK...EVEN
THOUGH THE HRRR MODEL HAS BACKED DOWN ON THIS. AT THIS TIME JUST KEPT
IT THUNDER VICINITY. A LITTLE BREAK MAY OCCUR EARLY THIS EVENING
OVER NE OH AND NW PA WITH SCATTERED SHOWERS AND THUNDERSTORMS
DEVELOPING OVER NW OH AND SPREADING EAST AND THEN A BETTER CHANCE
OF SHOWERS AND THUNDERSTORMS AFTER MIDNIGHT AS THE FRONT
APPROACHES.
OUTLOOK...WILL LIKELY HAVE NON VFR CEILINGS ACROSS NE OH/NW PA
THURSDAY THROUGH FRIDAY.
&&
.MARINE...
SOME ACTIVE WEATHER FOR THE LAKE WILL BEGIN ESPECIALLY TONIGHT AND
LAST INTO FRIDAY. SOUTHWEST WINDS ON THE LAKE TODAY WILL STAY BELOW
SMALL CRAFT ADVISORY CONDITIONS EVEN ON THE EAST END. THE COLD FRONT
WILL MOVE ACROSS THE LAKE LATE TONIGHT AND EARLY THURSDAY MORNING.
SOME OF THE THUNDERSTORMS AHEAD OF THE FRONT WILL LIKELY PROMPT
SPECIAL MARINE WARNINGS TO BE ISSUED.
SOME QUESTION HOW QUICKLY THE WINDS WILL PICK UP ON THE LAKE
THURSDAY BEHIND THE COLD FRONT. WENT TOWARD THE FASTER GFS IN
INCREASING THE WINDS ESPECIALLY ON THE EAST END AND THEN THE WEST
END THURSDAY NIGHT. EVENTUALLY A SMALL CRAFT ADVISORY WILL BE NEEDED
ON MUCH OF LAKE ERIE. THE THREAT FOR A SMALL CRAFT ADVISORY
CONDITIONS WILL LAST INTO FRIDAY NIGHT. PLENTY OF COLD AIR WILL BE
FLOWING ACROSS THE LAKE AND THAT MAY GENERATE SOME WATERSPOUTS AND
THUNDER BESIDES THE SHOWERS ESPECIALLY ON FRIDAY AS THE LAKE AND 850
MB TEMPERATURE DIFFERENCE WILL BE NEAR 20C AND THE LAKE AND 500 MB
TEMPERATURE DIFFERENCE WILL BE AROUND 40C.
HIGH PRESSURE WILL BUILD OVER THE LAKE ON SATURDAY AND THEN MOVE
EAST ON SUNDAY ALLOWING THE SOUTHWEST FLOW TO RETURN. A FRONT WILL
CROSS THE LAKE SUNDAY NIGHT INTO MONDAY SHIFTING THE WINDS TO
ONSHORE AS THE HIGH WILL TRY TO BUILD IN. THE WINDS AND WAVES ARE
EXPECTED TO BE BELOW SMALL CRAFT ADVISORY CONDITIONS EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...MULLEN/OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
736 AM EDT WED SEP 11 2013
.SYNOPSIS...
A COLD FRONT LOCATED FROM NORTHERN LOWER MICHIGAN BACK TO
DES MOINES IOWA EARLY THIS MORNING WILL MOVE SOUTH
TODAY...REACHING NORTHERN OH/NW PA THURSDAY MORNING. A SECONDARY
TROUGH WILL MOVE THROUGH THURSDAY AFTERNOON. A SIGNIFICANT AIRMASS
CHANGE WILL TAKE PLACE...WITH TEMPERATURES TURNING FROM ABOVE
NORMAL HEAT TO A BELOW NORMAL CHILL FOR FRIDAY INTO THE WEEKEND.
HIGH PRESSURE WILL BE OVER THE REGION SATURDAY AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A NUMBER OF ITEMS TO CONSIDER FOR TODAY. STRONG RIDGE OVER THE
OHIO VALLEY WILL BEGIN TO BREAK DOWN. A FRONTAL SYSTEM OVER THE
CENTRAL GREAT LAKES WILL BEGIN TO MAKE PROGRESS SOUTH...ALTHOUGH
SLOW AT FIRST. ONE INITIAL SHORTWAVE SHEARS OFF TO NEW ENGLAND
BRINGING THE FRONT INTO CENTRAL LOWER MI FOR THIS AFTERNOON. A
STRONGER SHORTWAVE COMING OUT OF SOUTH CENTRAL CANADA WILL CARVE
OUT THE TROUGH FOR THE GREAT LAKES AND GIVE THAT FRONT A PUSH
SOUTH OVERNIGHT. FIRST QUESTION BECOMES HOW MUCH IN THE WAY OF
SHOWERS/STORMS DO WE GET BEFORE 6P. AN AREA OF DEEPER MOISTURE
THAT 24 HRS AGO WAS NEAR PADUCAH IS NOW ACROSS SOUTHWEST OHIO.
MODEL GUIDANCE SHOWERS THAT A FEW SHOWERS/TS INITIATE WITH THIS
ACROSS OUR SOUTHEAST COUNTIES INCLUDING YOUNGSTOWN AND
AKRON/CANTON. HAVE FOCUSED SOME AFTERNOON PRECIP CHANCES THERE.
ALSO A LITTLE CONCERNED WITH AREA FROM FINDLAY TO MANSFIELD FOR AN
ISOLATED STORM. FINALLY SOME PREFRONTAL ACTIVITY IS POSSIBLE
ACROSS SE MI AND THEREFORE ALSO THE TOLEDO AREA. SPC SLIGHT RISK
IS ACROSS THE NORTHERN HALF OF THE AREA FOR STORMS LATE THIS
AFTERNOON AND EVENING. AGREE WITH THAT. NEXT QUESTION IS
TEMPERATURES. THE ONLY THING SAVING US FROM A REPEAT OF YESTERDAY
IS THE PRESENCE OF ADDITIONAL CLOUD COVER. THIS MAY BE JUST ENOUGH
TO KEEP US OUT OF HEAT ADVISORY TERRITORY. UPPER 80S ACROSS THE
SOUTHEAST TO LOWER 90S ACROSS THE I-75 CORRIDOR.
ONLY MINOR SKY COVER ADJUSTMENTS WERE MADE WITH THIS EARLY MORNING
UPDATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
SO STRONGER SHORTWAVE THAT WILL AMPLIFY THE TROUGH ACROSS THE
GREAT LAKES WILL PUSH THE COLD FRONT SOUTH TONIGHT. AT 6 PM STORMS
MAY BE ONGOING ACROSS FAR NW OH OR BE CLOSE BY. SOME CONCERN FOR
SEVERE STORMS ESPECIALLY ACROSS THE LAKESHORE COUNTIES. WIND WOULD
BE THE PRIMARY THREAT. AREA WILL BECOME MODESTLY UNSTABLE AND
SHEAR WILL BEGIN TO INCREASE AS THE UPPER TROUGH APPROACHES. WILL
JUST HAVE TO WATCH FRONTAL TIMING AND ANY PREFRONTAL AREAS OF
CONVERGENCE. MARCH LIKELY AND CATEGORICAL PRECIP CHANCES SOUTHWARD
OVER THE COURSE OF THE NIGHT AND INTO THURSDAY MORNING.
CONTINUED PRECIPITATION CHANCES INTO MUCH OF THURSDAY. THERE ARE
INDICATIONS OF A SECONDARY TROUGH THAT MAY AID IN A FEW ADDITIONAL
SHOWERS/TS. THE COLD PUSH WITH THIS SYSTEM IS SLIGHTLY
DELAYED...AND IS ASSOCIATED MORE WITH THE SECONDARY TROUGH. SO
THURSDAY WILL TURN OUT NEAR NORMAL FOR HIGHS. THE BIG CHANGE COMES
FOR FRIDAY.
WHILE THERE MAY BE A LULL IN PRECIPITATION THURSDAY EVENING...AS
THE COLDER AIR FILTERS IN AND THE UPPER TROUGH APPROACHES...LAKE
EFFECT CONDITIONS BEGIN TO TAKE SHAPE. SCATTERED SHOWERS STARTING
LATE THURSDAY NIGHT AND CONTINUING INTO FRIDAY POSSIBLE. HAVE
RAISED POPS ACROSS NRN OH/NW PA. ALSO HAVE ADDED THE MENTION OF
ISOLATED THUNDER FOR EAST OF CLEVELAND. LAKE TO H5 TEMPERATURE
DIFFERENCE GREAT ENOUGH FOR THE POSSIBILITY OF THUNDER WITHIN THE
LAKE EFFECT SHOWERS. TEMPERATURES FRIDAY WILL STRUGGLE TO GET INTO
THE 60S...WITH SOME PARTS OF NW PA/FAR NE OH STAYING IN THE UPPER
50S.
LAKE EFFECT SHOWERS SHOULD BE CONFINED TO FRIDAY AND MAYBE FRIDAY
NIGHT. AFTER THAT RIDGING AND DRYING BEGIN TO WORK INTO THE AREA
ENDING THAT THREAT. TEMPS FRIDAY NIGHT TO BE IN THE 40S. WITH
CLEARING ACROSS THE WEST TEMPS WILL BE CLOSER TO 40. SATURDAY
HIGHS SIMILAR..60 TO 65. BY SATURDAY NIGHT MORE OF THE AREA WILL
BE CLEARER AND MORE LOWER 40S ARE EXPECTED. IT IS DEFINITELY
POSSIBLE TO GET UPPER 30S DEPENDING ON CLOUD COVER.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
THIS PORTION OF THE EXTENDED DOES NOT LOOK VERY ACTIVE. HIGH
PRESSURE WILL BE MOVING EAST ON SUNDAY AND THAT WILL ALLOW A COLD
FRONT TO MOVE IN SUNDAY NIGHT INTO MONDAY BEFORE HIGH PRESSURE
BUILDS BACK IN. THE 00Z GFS AND ECMWF NOW AGREE WITH THIS SOLUTION.
AT THIS TIME KEPT THE POPS AROUND 20%. THIS MAY HAVE TO BE RAISED
SOME IF THE TREND REMAINS THE SAME. KEPT CLOSE TO HPC GUIDANCE FOR
THE TEMPERATURE FORECAST WHICH HAS SLIGHTLY BELOW NORMAL TEMPERATURES.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
THE BIG QUESTION IS THE TIMING OF THE THUNDERSTORMS FOR TODAY AND
TONIGHT. IN THE MEANTIME INCREASING MID AND HIGH CLOUDS FOR THE
MORNING. ANY FOG WILL DISSIPATE BY MID MORNING BUT SOME HAZE COULD
CONTINUE INTO THE AFTERNOON.
THE MODELS ARE FAIRLY CONSISTENT IN INCREASING THE LOW LEVEL
MOISTURE BY MID TO LATE MORNING OVER NE OH AND NW PA AND THEN
DEVELOPING SCATTERED SHOWERS AND THUNDERSTORMS. THIS IS OK...EVEN
THOUGH THE HRRR MODEL HAS BACKED DOWN ON THIS. AT THIS TIME JUST KEPT
IT THUNDER VICINITY. A LITTLE BREAK MAY OCCUR EARLY THIS EVENING
OVER NE OH AND NW PA WITH SCATTERED SHOWERS AND THUNDERSTORMS
DEVELOPING OVER NW OH AND SPREADING EAST AND THEN A BETTER CHANCE
OF SHOWERS AND THUNDERSTORMS AFTER MIDNIGHT AS THE FRONT
APPROACHES.
OUTLOOK...WILL LIKELY HAVE NON VFR CEILINGS ACROSS NE OH/NW PA
THURSDAY THROUGH FRIDAY.
&&
.MARINE...
SOME ACTIVE WEATHER FOR THE LAKE WILL BEGIN ESPECIALLY TONIGHT AND
LAST INTO FRIDAY. SOUTHWEST WINDS ON THE LAKE TODAY WILL STAY BELOW
SMALL CRAFT ADVISORY CONDITIONS EVEN ON THE EAST END. THE COLD FRONT
WILL MOVE ACROSS THE LAKE LATE TONIGHT AND EARLY THURSDAY MORNING.
SOME OF THE THUNDERSTORMS AHEAD OF THE FRONT WILL LIKELY PROMPT
SPECIAL MARINE WARNINGS TO BE ISSUED.
SOME QUESTION HOW QUICKLY THE WINDS WILL PICK UP ON THE LAKE
THURSDAY BEHIND THE COLD FRONT. WENT TOWARD THE FASTER GFS IN
INCREASING THE WINDS ESPECIALLY ON THE EAST END AND THEN THE WEST
END THURSDAY NIGHT. EVENTUALLY A SMALL CRAFT ADVISORY WILL BE NEEDED
ON MUCH OF LAKE ERIE. THE THREAT FOR A SMALL CRAFT ADVISORY
CONDITIONS WILL LAST INTO FRIDAY NIGHT. PLENTY OF COLD AIR WILL BE
FLOWING ACROSS THE LAKE AND THAT MAY GENERATE SOME WATERSPOUTS AND
THUNDER BESIDES THE SHOWERS ESPECIALLY ON FRIDAY AS THE LAKE AND 850
MB TEMPERATURE DIFFERENCE WILL BE NEAR 20C AND THE LAKE AND 500 MB
TEMPERATURE DIFFERENCE WILL BE AROUND 40C.
HIGH PRESSURE WILL BUILD OVER THE LAKE ON SATURDAY AND THEN MOVE
EAST ON SUNDAY ALLOWING THE SOUTHWEST FLOW TO RETURN. A FRONT WILL
CROSS THE LAKE SUNDAY NIGHT INTO MONDAY SHIFTING THE WINDS TO
ONSHORE AS THE HIGH WILL TRY TO BUILD IN. THE WINDS AND WAVES ARE
EXPECTED TO BE BELOW SMALL CRAFT ADVISORY CONDITIONS EARLY NEXT WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...OUDEMAN
SHORT TERM...OUDEMAN
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1111 AM EDT WED SEP 11 2013
.SYNOPSIS...
AN UNSEASONABLY HOT AND HUMID AIR MASS WILL REMAIN OVER THE REGION
TODAY...WITH AFTERNOON TEMPERATURES 10 TO 15 DEGREES ABOVE NORMAL
FOR EARLY SEPTEMBER. RELIEF FROM THE LATE-SUMMER HOT SPELL WILL
ARRIVE ON THURSDAY...AS A COLD FRONT BRINGS NUMEROUS THUNDERSTORMS
TO THE AREA...FOLLOWED BY ANOTHER TASTE OF FALL WITH BELOW NORMAL
TEMPERATURES EXPECTED FROM FRIDAY INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
HAZY AND UNCOMFORTABLE AIR WITH 78F DEWPOINT AT KLNS AND
WIDESPREAD L70 DEWPOINTS ELSEWHERE. THE TEMPS ARE GETTING NEAR THE
CONVECTIVE TEMP...AND CU ALREADY GROWING VERY TALL OVER THE
LAURELS. CAPES CRAZY HIGH PER LATEST RUC AND VERIFYING EARLIER
FCSTS. SO THE GOING FCST HAS BEEN HELD INTACT SAVE FOR A BUMP IN
THE POPS FOR THE HIGHER ELEVATIONS WHERE CONFIDENCE HAS INCREASED.
TWEAK OR TWO TO SKY COVER AS WELL. ONE BLIP ON PPI OVER INDIANA CO
IS LIKELY JUST THE FIRST OF THE SCT SHRA TO DEVELOP SHORTLY. EARLY
CONVECTION ALONG THE ALLEGHENIES SIMILARLY FCST TO DO THE SPLIT TO
THE EAST AND NORTH AND MAY AVOID MY CRISPY BROWN LAWN.
DESPITE PWATS NEAR 2 INCHES...WIND PROFILE LENDS ITSELF TO STORM
MOTION STEADY BUT SLOW TO THE NORTHEAST. THUS...NO TRAINING
EXPECTED AND SHOWERS SHOULD BE BRIEF.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH 6 AM THURSDAY/...
THE GUIDANCE IS DEPICTING AN INTERESTING MESOSCALE SET-
UP...SHOWING THE BULK OF CONVECTIVE PCPN FOCUSED ALONG THE
ALLEGHENIES...WHERE IT APPEARS COOLER MID-LVL TEMPS AND TERRAIN-
INDUCE LIFT MAY OFFSET SFC MESO RIDGING. THE HIGHER INSTABILITY
AND STEEPER LAPSE RATES ARE FCST E OF THE MTNS ALONG A PRE-
FRONTAL/LEE TROUGH AXIS CENTERED NEAR/ALONG THE SUSQ RIVER.
HOWEVER..700MB TEMPS SHOULD BE SLIGHTLY WARMER TO THE EAST WHICH
MAY ACT TO "CAP" THINGS OFF. FWIW...THE LATEST COSPA (HRRR+RAP)
DATA FAVORS THE ERN SLOPES OF THE ALLEGHENIES CLOSER TO THE LEE-
TROF AXIS. THE SWODY1 HAS NRN PA IN THE SLGT RISK...WHICH IS
LOCATED ON THE SRN EDGE OF THE BETTER WLY DEEP LYR SHEAR LOCATED
ACRS NY AND NEW ENGLAND. GIVEN LOW CONFIDENCE IN THE MESO
DETAILS...WENT WITH A BROAD-BRUSHED APPROACH WITH POPS AND WILL
ALLOW THE DAYSHIFT TO REFINE BASED ON RADAR TRENDS. IT WILL BE
ANOTHER HAZY HOT AND HUMID LATE-SUMMER DAY WITH MAXES IN THE
85-90F RANGE OR +10-15 DEGREES ABOVE EARLY SEPT. NORMALS. SOME
LOCATIONS COULD APPROACH/EXCEED DAILY RECORD HIGHS.
THERE SHOULD BE A LULL IN CONVECTIVE ACTIVITY AFTER DARK AS THE
BLYR COOLS/DESTABILIZES. FOCUS WILL SHIFT TO APPROACHING COLD FRONT
PUSHING SEWD ACRS THE LOWER GREAT LAKES...WITH THE HIGHEST POPS
OVER THE NW MTNS LATE TONIGHT INTO EARLY THU. IT WILL BE ANOTHER
MUGGY OVERNIGHT AND EARLY MORNING WITH LOWS 65-70F AND PATCHY
FOG/HAZE.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
UPPER RIDGING AND CONTINUING PRESENCE OF SURFACE HIGH PRESSURE
FROM CANADA WILL KEEP PENNSYLVANIA MAINLY DRY THROUGH THE LONG
TERM PERIOD. DEEP UPPER TROF OVER THE CENTRAL AND EASTERN GREAT
LAKES TO START THE PERIOD WILL LIFT OUT INTO NEW ENGLAND FRIDAY
AND SATURDAY...ALLOWING UPPER HEIGHTS TO BECOME MORE ZONAL
THROUGH THE REMAINDER OF PERIOD.
AT THE SURFACE...A COLD FRONT SHOULD BE EXITING TO THE EAST AT THE
START OF THE PERIOD ON FRIDAY...WITH THE FIRST LARGE SFC
ANTICYCLONE BUILDING IN THROUGH THE WEEKEND.
A WEAK SHORTWAVE IS PROGGED TO DROP THROUGH THE UPPER FLOW SOMETIME
MONDAY BRINGING ANOTHER FRONT. THE WEAKNESS OF THE SYSTEM AND THE
DRYNESS OF THE AIR IN PLACE BRINGING INTO QUESTION HOW MUCH PCPN MAY
ACCOMPANY THE FRONT...SO KEPT MINIMAL POPS ATTM. THE SECOND
ANTICYCLONE FOLLOWS TUE INTO WEDNESDAY FOR YET MORE DRY WEATHER.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
EXPECT MVFR-IFR VISBYS IN HZ TO IMPROVE TO VFR THRU THE
MORNING...GIVING WAY TO ANOTHER HAZY HOT AND HUMID DAY. TEMPS
ALOFT ARE NOT AS WARM AS YESTERDAY WHICH FAVORS A WEAKER CAP...AND
BETTER CHANCE FOR SCATTERED AFTERNOON TSTORMS. LATEST COSPA/CCFP
FAVORS CORRIDOR FROM JST-AOO TO UNV-IPT WITH TSTM IMPACT BTWN
17-19Z.
TSTORMS SHOULD WEAKEN AND DISSIPATE INTO TONIGHT/00-04Z. LLVL MSTR
WILL REMAIN VERY HIGH OVERNIGHT AND LKLY RESULT SOME MVFR VISBYS.
THE FOCUS WILL SHIFT TO A WELL-DEFINED COLD FRONT PUSHING SEWD
FROM THE LWR LKS. EXPECT THIS BOUNDARY TO BE CONVECTIVELY ACTIVE
AS IT CROSSES THE AIRSPACE ON THURSDAY...WITH THE POTENTIAL FOR
STG TO SVR TSTORMS.
OUTLOOK...
THU...SCT-NMRS TSTM IMPACTS PSBL WITH COLD FROPA.
FRI...MVFR/SCT SHOWERS PSBL N/W...VFR CENTRAL/EAST. BREEZY.
SAT-SUN...VFR. NO SIG WX.
&&
.EQUIPMENT...
BFD OBS HAVE BEEN RESTORED BY FAA WORK.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...STEINBUGL
NEAR TERM...DANGELO/STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...DEVOIR/GARTNER
AVIATION...DANGELO/STEINBUGL
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1143 PM CDT TUE SEP 10 2013
.AVIATION...
ISOLD SHRA POSSIBLE OVERNIGHT. ISOLD TO SCT SHRA/TSRA EXPECTED
WEDNESDAY WITH GREATEST COVERAGE OVER THE RIO GRANDE. HAVE
MENTIONED TEMPO -RA FOR KDRT OVERNIGHT INTO EARLY WEDNESDAY.
OTHERWISE...NO MENTION IN TAFS DUE TO LOW PROBABILITY. VFR SKIES
LATE EVENING LOWER TO MVFR/IFR CIGS/VSBYS OVERNIGHT INTO EARLY
WEDNESDAY MORNING. DUE TO MOIST AIRMASS...PATCHY FG WITH VLIFR
VSBYS IS POSSIBLE. CIGS LIFT TO VFR AND BR/FG DISSIPATE BY MIDDAY.
E TO SE WINDS 7 TO 12 KTS DECREASE TO LESS THAN 6 KTS OVERNIGHT
AND THEN INCREASE TO 7 TO 12 KTS LATE WEDNESDAY AFTERNOON.
DOWNDRAFT WIND GUSTS TO 35 KTS ARE POSSIBLE IN AND NEAR SHRA/TSRA.
&&
.PREV DISCUSSION... /ISSUED 854 PM CDT TUE SEP 10 2013/
UPDATE...
A DOWNWARD TREND TO WHAT HAS OCCURRED THE PAST FEW EVENINGS IS
EXPECTED TO CONTINUE INTO LATE TONIGHT...WITH LIGHT STREAMER
SHOWERS EXPECTED TO REDEVELOP IN THE OVERNIGHT HOURS INTO
DAYBREAK. THIS IS REINFORCED BY THE RECENT RUC AND HRRR RUNS. WILL
DROP CHANCES TO 20 PERCENT OR LESS AND REMOVE THUNDER FOR ALL BUT
THE SOUTHEAST COUNTIES AROUND DAYBREAK. A FEW LIGHTNING STRIKES
MAY DEVELOP THIS EVENING NEAR THE RIO GRANDE...BUT EXPECT THEM TO
BE ACROSS THE BORDER WHERE TERRAIN FEATURES WILL CONTRIBUTE TO
CELL GROWTH.
PREV DISCUSSION... /ISSUED 646 PM CDT TUE SEP 10 2013/
AVIATION...
ISOLD SHRA/TSRA SLOWLY END THIS EVENING...HOWEVER LINGERS OVER THE
RIO GRANDE OVERNIGHT. ISOLD TO SCT SHRA/TSRA EXPECTED WEDNESDAY
WITH GREATEST COVERAGE OVER THE RIO GRANDE. HAVE MENTIONED TEMPO
-RA FOR KDRT OVERNIGHT INTO EARLY WEDNESDAY. OTHERWISE...NO
MENTION IN TAFS DUE TO LOW PROBABILITY. VFR SKIES THIS EVENING
LOWER TO MVFR/IFR CIGS/VSBYS OVERNIGHT INTO EARLY WEDNESDAY
MORNING. DUE TO MOIST AIRMASS...PATCHY FG WITH VLIFR VSBYS IS
POSSIBLE. CIGS LIFT TO VFR AND BR/FG DISSIPATE BY MIDDAY. E TO SE
WINDS 7 TO 12 KTS DECREASE TO LESS THAN 6 KTS OVERNIGHT AND THEN
INCREASE TO 7 TO 12 KTS LATE WEDNESDAY AFTERNOON. DOWNDRAFT WIND
GUSTS TO 35 KTS ARE POSSIBLE IN AND NEAR SHRA/TSRA.
PREV DISCUSSION... /ISSUED 302 PM CDT TUE SEP 10 2013/
SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...
THIS AFTERNOON SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WERE
OCCURRING ACROSS MUCH OF SOUTH CENTRAL TEXAS AS DAYTIME HEATING
INTERACTED WITH THE TROPICAL AIRMASS. THE AWIPS TOTAL BLENDED PWAT
PRODUCT STILL DEPICTED VALUES RANGING FROM 1.8 INCHES NORTH TO 2.0
INCHES SOUTH. THESE VALUES ARE ASSOCIATED WITH LOCALLY HEAVY
RAINFALL. THE CONVECTION WILL DIMINISH IN AREA COVERAGE OVERNIGHT
WITH THE LOSS OF HEATING. HOWEVER ISOLATED SHOWERS AND THUNDERSTORMS
WILL CONTINUE OVER THE RIO GRANDE PLAINS AFTER MIDNIGHT WHERE
DEEP TROPICAL MOISTURE WILL PERSIST. LOWS WILL BE SLIGHTLY ABOVE
SEASONAL NORMALS. AN UPPER LEVEL RIDGE OVER THE OHIO VALLEY WILL
BUILD TO THE SOUTHWEST INTO TEXAS ON WEDNESDAY KEEPING THE DEEPER
MOISTURE AXIS WEST OVER THE RIO GRANDE PLAINS. THUS CONVECTIVE
COVERAGE ON WEDNESDAY WILL RANGE FROM ISOLATED NORTHEAST TO
SCATTERED WEST. CLOUDS AND PCPN WILL KEEP AFTERNOON HIGHS AROUND
NORMAL ON WEDNESDAY. SHOWERS AND THUNDERSTORMS WILL END BY
MIDNIGHT WITH LOWS WEDNESDAY NIGHT SIMILAR TO WHAT IS EXPECTED
TONIGHT.
LONG TERM (THURSDAY THROUGH TUESDAY)...
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL OCCUR GENERALLY
ALONG AND SOUTH OF HIGHWAY 90 ON THURSDAY AS THE EASTERLIES ENHANCE
CONVECTION ON THE SEA-BREEZE BOUNDARY. FRIDAY IS EXPECTED TO BE DRY
AS THE UPPER HIGH BRIEFLY BECOMES CENTERED OVER NORTH TEXAS. ALL
EYES WILL BE ON THE GULF OF MEXICO AND THE BAY OF CAMPECHE OVER
THE WEEKEND. A TROF OF LOW PRESSURE CURRENTLY LOCATED OVER THE
CARIBBEAN NEAR BELIZE WILL MOVE WESTWARD INTO THE BAY OF CAMPECHE
BY THURSDAY. A TROPICAL DEPRESSION IS EXPECTED TO FORM OVER THE
SOUTHWESTERN GULF LATER THIS WEEK AND HAS A HIGH CHANCE OF BECOMING
A TROPICAL CYCLONE OVER THE WEEKEND. THE TRACK OF THIS SYSTEM WILL
HAVE A DIRECT IMPACT ON THE FORECAST FOR SOUTH CENTRAL TEXAS. ATTM
THE MODEL CONSENSUS IS FOR THE SYSTEM TO MOVE WESTWARD MAKING LANDFALL
IN MEXICO ON MONDAY NEAR TAMPICO. THE 12Z GFS IS THE FURTHEST NORTH
WITH THE TRACK...MOVING ONSHORE SOUTH OF BROWNSVILLE...THEN MOVING
NORTHWEST UP THE RIO GRANDE. IN ANY EVENT INCREASING TROPICAL MOISTURE
WITH THIS SYSTEM WILL LEAD TO INCREASING POPS WITH THE POTENTIAL
FOR HEAVY RAINFALL ACROSS SOUTH CENTRAL TEXAS EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 74 95 74 95 74 / 10 10 - 10 -
AUSTIN BERGSTROM INTL AIRPORT 70 94 70 94 70 / 10 10 10 10 -
NEW BRAUNFELS MUNI AIRPORT 70 94 70 94 69 / 10 20 10 20 -
BURNET MUNI AIRPORT 70 92 71 93 71 / 10 10 - 10 -
DEL RIO INTL AIRPORT 75 90 73 92 73 / 20 30 10 20 -
GEORGETOWN MUNI AIRPORT 71 94 71 94 72 / 10 10 - 10 -
HONDO MUNI AIRPORT 73 93 72 93 71 / 20 20 10 10 -
SAN MARCOS MUNI AIRPORT 70 95 71 95 70 / 10 10 10 10 -
LA GRANGE - FAYETTE REGIONAL 75 95 75 95 75 / 10 20 10 10 10
SAN ANTONIO INTL AIRPORT 75 94 75 93 74 / 20 20 10 10 -
STINSON MUNI AIRPORT 76 94 76 94 75 / 20 20 10 20 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...18
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1138 PM CDT TUE SEP 10 2013
.UPDATE...
ISSUED AT 639 PM CDT TUE SEP 10 2013
LOW TO MID LEVEL FRONTOGENESIS BEGINNING TO GET GOING FROM CENTRAL
IOWA INTO CENTRAL WISCONSIN...NOTED BY ISOLATED SHOWERS THAT HAVE
DEVELOPED. SO FAR ALL LIGHTNING ACTIVITY HAS STAYED DOWN TOWARDS
CENTRAL IOWA. HOWEVER...RAP/NAM/ECMWF SOUNDINGS ALL SHOW ELEVATED
INSTABILITY ON THE ORDER OF 250-750 J/KG LIFTED FROM 850MB. AS THE
FRONTOGENESIS STRENGTHENS PER MODEL PROGS THIS EVENING...
ANTICIPATING THAT SOME OF THE SHOWER ACTIVITY WILL TAKE ADVANTAGE
OF THIS INSTABILITY AND PRODUCE LIGHTNING. HRRR MODEL FORECASTS
SUGGEST THIS AS WELL. THEREFORE...HAVE ADDED ISOLATED- SCATTERED
THUNDERSTORMS BACK INTO THE FORECAST...MAINLY SOUTH OF INTERSTATE
90 WHERE THE ELEVATED INSTABILITY IS PROGGED. ADDITIONALLY...IT IS
POSSIBLE PRECIPITATION CHANCES WILL NEED TO BE RAISED ACROSS
PORTIONS OF THIS AREA WITH ADDED THUNDER. ECMWF/NAM/HRRR FORECASTS
THIS EVENING REALLY INCREASE PRECIPITATION COVERAGE. WILL MONITOR
TRENDS IN RADAR DATA TO SEE IF THE MODELS ARE HANDLING
PRECIPITATION OKAY. SO FAR THEY SEEM TO BE.
&&
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 244 PM CDT TUE SEP 10 2013
SURFACE MAP HAS LOW PRESSURE OVER LAKE SUPERIOR WITH A COLD FRONT
EXTENDING THROUGH CENTRAL UPPER MI TO JUST NORTH OF LA CROSSE...AND
THEN THROUGH NORTHERN IA. RADAR MOSAIC WAS SHOWING A SCATTERED BAND
OF POST-FRONTAL SHOWERS ACROSS WESTERN UPPER MI THROUGH NORTH
CENTRAL WI INTO SOUTHERN MN. NOT MUCH OF THIS REFLECTIVITY WAS BEING
REALIZED AT THE SURFACE...AND WHERE IT WAS...RAINFALL WAS SCANT WITH
GENERALLY .02 INCH OR LESS. PER THE RAP MODEL...THIS BAND OF SHOWERS
WAS TIED TO SOME 850-700MB FRONTOGENESIS BEHIND THE SURFACE FRONT.
OTHERWISE...TEMPERATURES ACROSS THE AREA RANGED FROM NEAR 80 ACROSS
NORTH CENTRAL WI...TO A FEW LOWER 90S ACROSS NORTHEAST IA INTO
SOUTHWEST WI.
SO...MAIN FORECAST CHALLENGE WILL BE RAIN CHANCES TONIGHT INTO
WEDNESDAY WITH THE PASSAGE OF THIS FRONT AND POST-FRONTAL FORCING.
LOOK FOR THE THE MAIN SURFACE FRONT TO CONTINUE PUSHING SOUTHEAST
THROUGH THE AREA TONIGHT WHILE 850-700MB FRONTOGENESIS LAGS BEHIND.
RAP SHOWING 850-700MB FG-FORCING...ALBEIT NOT OVERLY
STRONG...MAINTAINING ITSELF AS IT DRIFTS SOUTHEAST ACROSS THE AREA
THIS EVENING/OVERNIGHT. THE NAM ACTUALLY SHOWS THIS FORCING
INTENSIFYING A BIT...BUT MORE ACROSS EAST CENTRAL WI. BASED ON WHAT
IS HAPPENING NOW AND FORECAST FORCING SIGNAL...HAVE DOWNPLAYED
RAIN CHANCES AND DROPPED THUNDER MENTION AS FORCING AND CAPE WANE.
PLAN ON OVERNIGHT LOW TEMPERATURES IN THE UPPER 50S TO THE MIDDLE
60S.
FOR WEDNESDAY...WILL BE WATCHING THE COLD FRONTAL BOUNDARY CONTINUE
TO SLIP SOUTH OF OUR AREA WITH 850-700MB FG-FORCING ALMOST
NON-EXISTENT. AS SUCH...PUSHED ANY REMAINING SHOWER CHANCES SOUTH OF
THE FORECAST AREA BY AFTERNOON. OTHERWISE...LOOKING AT A MID-LEVEL
TROUGH/REINFORCING SHOT OF COOLER AIR DROPPING INT NORTHERN WI BY
LATE IN THE AFTERNOON. MODELS ARE PRODUCING SOME SHRA/ISOLATED
THUNDER WITH THIS WAVE...BUT KEEPING IT NORTH OF THE FORECAST AREA.
OTHERWISE...LOOK FOR HIGHS ACROSS THE FORECAST AREA IN THE 80-85
DEGREE RANGE.
COOLER/DRIER AIR FILTERS IN FOR WEDNESDAY NIGHT AS HIGH PRESSURE
BUILDS INTO THE UPPER MISSISSIPPI RIVER REGION FROM THE CENTRAL
CANADIAN PROVINCES. LOOK FOR OVERNIGHT LOWS IN THE 50-60 DEGREE
RANGE WITH NORTHWEST WINDS OF 5-10 MPH.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 244 PM CDT TUE SEP 10 2013
CONTINUED DRY/COOL FLOW CONTINUES INTO THE AREA ON THURSDAY AS HIGH
PRESSURE BUILDS IN ACROSS THE NORTHERN PLAINS/MN. FAIRLY STEEP LAPSE
RATES WILL BE IN PLACE WITH 925MB TEMPERATURES IN THE 10-17C RANGE
AND 500MB IN THE -5 TO -15C RANGE. THIS IS EXPECTED TO PRODUCE A
PRETTY GOOD FIELD OF CUMULUS/STRATOCUMULUS...ESPECIALLY AREAS
NORTHEAST OF I-94. ANY SHOWER THREAT LOOKS TO STAY NORTH OF THE
AREA.
HIGH PRESSURE WILL CONTINUE TO DOMINATE THE WEATHER PICTURE THURSDAY
NIGHT THROUGH SATURDAY. THURSDAY NIGHT AND ESPECIALLY FRIDAY NIGHT
WILL SET UP FAVORABLE RIVER VALLEY FOG CONDITIONS WITH CLEAR SKIES
AND LIGHT/CALM WINDS. RATHER CHILLY OVERNIGHT LOWS ARE ALSO EXPECTED
THURSDAY NIGHT AND FRIDAY NIGHT WITH PLANNED FORECAST LOWS
DROPPING INTO UPPER 30S IN THE FAVORED COLD SPOTS ALONG AND
NORTHEAST OF I-94. WILL HAVE TO WATCH CLOSELY FOR THE POTENTIAL OF
PATCHY FROST ACROSS THIS AREA THURSDAY NIGHT AS THE COLDEST CORE OF
AIR ALOFT SINKS ACROSS THE REGION.
WILL BE WATCHING THE HIGH DRIFT EAST OF THE AREA SATURDAY NIGHT
INTO SUNDAY AS A FAIRLY VIGOROUS //AT LEAST ACCORDING TO THE
ECMWF// MID-LEVEL TROUGH AND SURFACE COLD FRONT DROPS SOUTHEAST
INTO THE AREA. THE GFS IS NOT AS ENTHUSED AS THE ECMWF. NEW 12Z
ECMWF LOOKING MORE LIKE THE GFS NOW....KEEPING POPS SPLIT TO THE
NORTH AND SOUTH OF THE AREA. LOWERED POPS FOR NOW...BUT IF TREND
CONTINUES...COULD PROBABLY DROP POPS ALTOGETHER FOR THE AREA. WILL
KEEP AN EYE ON THIS.
A STRONG AREA OF CANADIAN HIGH PRESSURE BUILDS INTO THE AREA FOR
SUNDAY NIGHT AND HOLDS AT LEAST THROUGH MONDAY NIGHT. THIS IS
EXPECTED TO YIELD DRY CONDITIONS WITH SLIGHTLY BELOW NORMAL
TEMPERATURES THROUGH THE PERIOD. LOOK FOR OVERNIGHT LOWS IN THE
UPPER 40S TO THE LOWER 50S WITH HIGHS IN THE MIDDLE 60S TO AROUND
THE 70 DEGREE MARK.
THE ECMWF AND GFS THEN DIFFER A BIT WITH SPEED OF A SHORTWAVE TROUGH
PUSHING EAST OUT OF THE PLAINS ON TUESDAY. THE ECMWF IS THE FASTER
OF THE TWO...SPREADING SHOWER/THUNDERSTORM CHANCES IN DURING THE
DAY. THE GFS IS MUCH SLOW AND MAINTAINS RIDGING ACROSS THE AREA.
WILL KEEP A DRY/COOL FORECAST GOING FOR NOW AND WAIT FOR BETTER
MODEL CONSENSUS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1138 PM CDT TUE SEP 10 2013
WEST TO NORTHWEST WINDS WILL CONTINUE TO ADVECT DRIER AIR IN THE
LOWER LEVELS OF THE ATMOSPHERE INTO THE TAF SITES THROUGH
WEDNESDAY NIGHT. THIS DRIER AIR WILL HELP TO MAINTAIN VFR
CONDITIONS. DAYTIME MIXING AND A RELATIVELY TIGHT PRESSURE
GRADIENT MAY ALLOW WINDS TO GUST TO 15 KT OR SO AT LSE...WITH
BOTH LSE AND RST LIKELY TO SEE WINDS SUSTAINED AROUND 10 KT. WINDS
AND GUSTS WILL SUBSIDE QUICKLY WITH LOSS OF DAYTIME HEATING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
213 AM EDT FRI SEP 13 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BE IN THE FORECAST AREA FRIDAY.
COOLER WEATHER WILL OCCUR BEHIND THE FRONT SATURDAY AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ISOLATED SHOWERS DEVELOPING...CSRA AND EAST MIDLANDS. HRRR GUIDANCE
SUGGESTS A FEW SHOWERS POSSIBLE OVERNIGHT. POPS REMAIN LOW HOWEVER
WITH WEAK FORCING AS FRONT APPROACHES. RAISED POPS FROM PREVIOUS
FORECAST DURING THE EARLY MORNING HOURS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
AS THE UPPER TROUGH MOVES ACROSS NEW ENGLAND AND THE MID-ATLANTIC
STATES A COLD FRONT WILL PUSH SOUTHEASTWARD THROUGH THE FORECAST
AREA FRIDAY AFTERNOON. AGAIN MOISTURE IS NOT IDEAL BUT SOME
POOLING OF MOISTURE AHEAD OF THE FRONT IS EXPECTED AND THERE
SHOULD BE ENOUGH INSTABILITY FROM DAYTIME HEATING ALONG WITH LOW-
LEVEL CONVERGENCE ALONG THE FRONTAL BOUNDARY TO WARRANT LOW CHANCE
POPS ALONG AND AHEAD OF THE FRONT. WITH LIMITED MOISTURE...WILL
CARRY A 20 PERCENT POP EVERYWHERE MAINLY FRIDAY IN THE AFTERNOON.
FRIDAY HIGHS ARE EXPECTED TO BE AROUND THE 90 DEGREE MARK. THE
CHANCE OF SHOWERS AND STORMS WILL DIMINISH FROM THE NORTHWEST AS
THE FRONT PUSHES THROUGH AND COOLER...DRIER AIR BUILDS INTO THE
AREA. WEAK COLD ADVECTION WILL ALLOW TEMPERATURES TO FALL INTO THE
LOWER TO MID 60S FRIDAY NIGHT. COOLER SATURDAY WITH DRY HIGH
PRESSURE. HIGHS SATURDAY FROM THE UPPER 70S NORTH TO LOWER 80S
SOUTH. LOWS SATURDAY NIGHT FROM THE MIDDLE 50S NORTH TO UPPER 50S
SOUTH.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT SUNDAY AS SIGNIFICANT
MID LEVEL SHORT WAVE MOVES EAST AND SUPPRESSES WESTERN EXTENSION
OF BERMUDA RIDGE TO THE SOUTH TO NEAR THE GULF COAST REGION. BY
MONDAY AND TUESDAY...THE MAJOR UPPER TROUGH IS RE-ESTABLISH ALONG
THE EAST COAST. SOME MODEL DIFFERENCES MONDAY AND TUESDAY AS UPPER
TROUGH ALLOWS A WEAK COLD FRONT TO DROP TO THE SOUTH INTO THE
CAROLINAS. GFS BRINGS ENOUGH MOISTURE FOR ABOUT A 20 PERCENT CHANCE
OF PRECIPITATION WHILE THE ECMWF LOOKS DRIER. DECIDED TO GO WITH
CURRENT DRIER FORECAST WITH NO POPS. AT ANY RATE...MORE FALL-LIKE
SUNDAY WITH HIGHS ONLY IN THE LOWER 80S. WITH SOME UPPER HEIGHT
RISES MONDAY AND TUESDAY...THE MIDDLE 80S LOOKED BETTER. LOWS IN
THE UPPER 50S SUNDAY NIGHT ALSO INCREASE TO THE LOWER 60S MONDAY
NIGHT.
WEDNESDAY THROUGH THURSDAY...MORE MODEL DIFFERENCES LATE IN THE
PERIOD. GFS TRIES TO BUILD UPPER RIDGE TOWARD THE EAST WEDNESDAY
AND THURSDAY AND GIVES WARMER HIGH TEMPERATURES IN THE UPPER 80S.
ON THE OTHER HAND...ECMWF HAS UPPER RIDGE MORE SUPPRESSED AS A
STRONGER NORTHERN STREAM SHORT WAVE MOVES EASTWARD TOWARD THE
GREAT LAKES. THE WEAK COLD FRONT SHOULD STILL BE IN THE AREA
WEDNESDAY AND MAY PICK UP ENOUGH MOISTURE FOR A 20 PERCENT CHANCE
ON WEDNESDAY. THIS WEAK FRONT IS EXPECTED TO HAVE DISSIPATED BY
THURSDAY BUT MORE CLOUDS AND A BETTER CHANCE OF PRECIPITATION
SHOULD FAVOR THE SLIGHTLY COOLER ECMWF TEMPERATURES OVER GFS.
SO...DECIDED TO GO WITH HIGHS IN THE MIDDLE 80S FOR WEDNESDAY
AND THURSDAY. OTHERWISE...OVERNIGHT LOWS FROM THE LOWER 60S
IN THE NORTH TO MIDDLE 60S IN THE SOUTH FOR TUESDAY NIGHT AND
WEDNESDAY NIGHT.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS TO DOMINATE THE TAF PERIOD.
COLD FRONT CONTINUES TO MOVE INTO THE REGION WITH A FEW SHOWERS
PASSING THE AGS/DNL AREA. SHOWERS IN THE UPSTATE CONTINUE TO
DIMINISH CROSSING THE MOUNTAINS WITH LOW CONFIDENCE ANY ACTIVITY
WILL REACH THE TAF SITES. WITH THE FRONT MOVING INTO THE AREA THE
THREAT OF FOG REMAINS TOO LOW TO INCLUDE IN TAFS. THE FRONT WILL
CROSS THE AREA DURING THE MORNING AND OFFSHORE IN THE AFTERNOON
WITH DRIER AIR AND NORTHERLY WINDS MOVING IN BEHIND THE FRONT. AS
SUCH EXPECT VFR CONDITIONS THROUGH THE PERIOD.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS TO AVIATION
EXPECTED AT THIS TIME.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1213 AM EDT FRI SEP 13 2013
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BE IN THE FORECAST AREA FRIDAY. COOLER
WEATHER WILL OCCUR BEHIND THE FRONT SATURDAY AND SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ISOLATED SHOWERS DEVELOPING...CSRA AND EAST MIDLANDS. HRRR GUIDANCE
SUGGESTS A FEW SHOWERS POSSIBLE OVERNIGHT. POPS REMAIN LOW HOWEVER
WITH WEAK FORCING AS FRONT APPROACHES. RAISED POPS FROM PREVIOUS
FORECAST DURING THE EARLY MORNING HOURS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
AS THE UPPER TROUGH MOVES ACROSS NEW ENGLAND AND THE MID-ATLANTIC
STATES A COLD FRONT WILL PUSH SOUTHEASTWARD THROUGH THE FORECAST
AREA FRIDAY AFTERNOON. AGAIN MOISTURE IS NOT IDEAL BUT SOME
POOLING OF MOISTURE AHEAD OF THE FRONT IS EXPECTED AND THERE
SHOULD BE ENOUGH INSTABILITY FROM DAYTIME HEATING ALONG WITH LOW-
LEVEL CONVERGENCE ALONG THE FRONTAL BOUNDARY TO WARRANT LOW CHANCE
POPS ALONG AND AHEAD OF THE FRONT. WITH LIMITED MOISTURE...WILL
CARRY A 20 PERCENT POP EVERYWHERE MAINLY FRIDAY IN THE AFTERNOON.
FRIDAY HIGHS ARE EXPECTED TO BE AROUND THE 90 DEGREE MARK. THE
CHANCE OF SHOWERS AND STORMS WILL DIMINISH FROM THE NORTHWEST AS
THE FRONT PUSHES THROUGH AND COOLER...DRIER AIR BUILDS INTO THE
AREA. WEAK COLD ADVECTION WILL ALLOW TEMPERATURES TO FALL INTO THE
LOWER TO MID 60S FRIDAY NIGHT. COOLER SATURDAY WITH DRY HIGH
PRESSURE. HIGHS SATURDAY FROM THE UPPER 70S NORTH TO LOWER 80S
SOUTH. LOWS SATURDAY NIGHT FROM THE MIDDLE 50S NORTH TO UPPER 50S
SOUTH.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT SUNDAY AS SIGNIFICANT
MID LEVEL SHORT WAVE MOVES EAST AND SUPPRESSES WESTERN EXTENSION
OF BERMUDA RIDGE TO THE SOUTH TO NEAR THE GULF COAST REGION. BY
MONDAY AND TUESDAY...THE MAJOR UPPER TROUGH IS RE-ESTABLISH ALONG
THE EAST COAST. SOME MODEL DIFFERENCES MONDAY AND TUESDAY AS UPPER
TROUGH ALLOWS A WEAK COLD FRONT TO DROP TO THE SOUTH INTO THE
CAROLINAS. GFS BRINGS ENOUGH MOISTURE FOR ABOUT A 20 PERCENT CHANCE
OF PRECIPITATION WHILE THE ECMWF LOOKS DRIER. DECIDED TO GO WITH
CURRENT DRIER FORECAST WITH NO POPS. AT ANY RATE...MORE FALL-LIKE
SUNDAY WITH HIGHS ONLY IN THE LOWER 80S. WITH SOME UPPER HEIGHT
RISES MONDAY AND TUESDAY...THE MIDDLE 80S LOOKED BETTER. LOWS IN
THE UPPER 50S SUNDAY NIGHT ALSO INCREASE TO THE LOWER 60S MONDAY
NIGHT.
WEDNESDAY THROUGH THURSDAY...MORE MODEL DIFFERENCES LATE IN THE
PERIOD. GFS TRIES TO BUILD UPPER RIDGE TOWARD THE EAST WEDNESDAY
AND THURSDAY AND GIVES WARMER HIGH TEMPERATURES IN THE UPPER 80S.
ON THE OTHER HAND...ECMWF HAS UPPER RIDGE MORE SUPPRESSED AS A
STRONGER NORTHERN STREAM SHORT WAVE MOVES EASTWARD TOWARD THE
GREAT LAKES. THE WEAK COLD FRONT SHOULD STILL BE IN THE AREA
WEDNESDAY AND MAY PICK UP ENOUGH MOISTURE FOR A 20 PERCENT CHANCE
ON WEDNESDAY. THIS WEAK FRONT IS EXPECTED TO HAVE DISSIPATED BY
THURSDAY BUT MORE CLOUDS AND A BETTER CHANCE OF PRECIPITATION
SHOULD FAVOR THE SLIGHTLY COOLER ECMWF TEMPERATURES OVER GFS.
SO...DECIDED TO GO WITH HIGHS IN THE MIDDLE 80S FOR WEDNESDAY
AND THURSDAY. OTHERWISE...OVERNIGHT LOWS FROM THE LOWER 60S
IN THE NORTH TO MIDDLE 60S IN THE SOUTH FOR TUESDAY NIGHT AND
WEDNESDAY NIGHT.
&&
.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
REGIONAL RADARS INDICATE ADDITIONAL THUNDERSTORM ACTIVITY ALONG
THE CENTRAL APPALACHIANS...BUT THIS ACTIVITY IS NOT EXPECTED TO
HOLD TOGETHER INTO OUR CWA TONIGHT DUE TO LIMITED MOISTURE AND
GENERAL NORTHWEST FLOW PATTERN. SO EXPECTING VFR CONDITIONS DURING
THE TAF PERIOD. SOME OF THE MOS GUIDANCE SHOWS THE POSSIBILITY OF
UPPER END MVFR FOG DURING THE EARLY MORNING HOURS...BUT CONFIDENCE
IN FORMATION IS NOT HIGH DUE TO DEVELOPMENT OF A LOW-LEVEL JET AND
LOW-LEVEL MIXING OVERNIGHT. SO AS STATED ABOVE...VFR FORECAST. THE
MAIN FRONT WILL BE PASSING THROUGH THE FORECAST AREA DURING THE
MORNING ON FRIDAY...BUT IT SHOULD MOVE THROUGH TAF SITES
DRY...WITH ONLY A WIND SHIFT TO THE NORTHWEST TO SHOW ITS PASSAGE.
SCATTERED CU EXPECTED THROUGH THE DAY...GENERALLY AROUND 4.5KFT.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED AT
THIS TIME.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
1241 AM CDT FRI SEP 13 2013
.UPDATE...
ISSUED AT 932 PM CDT THU SEP 12 2013
HAVE ADDED PATCHY FROST TO ALL REMAINING ZONES AND GRIDS FOR THE
REST OF THE NIGHT. THE FREEZE WARNING AREA STILL LOOKS GOOD...AS
WELL AS THE FROST ADVISORY AREA. CONSIDERED EXPANDING THE FROST
ADVISORY A BIT BUT DECIDED TO HOLD OFF AND ADD PATCHY FROST
MENTION TO THE REMAINDER OF THE NORTHLAND. CLOUDS HAVE CLEARED
NICELY ACROSS THE REGION...WITH CLEAR TO MOSTLY CLEAR SKIES FOR
THE REST OF THE NIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 322 PM CDT THU SEP 12 2013
AT 315PM/2015Z...SURFACE HIGH PRESSURE WAS CENTERED OVER THE
NORTHERN PLAINS...SOMEWHERE NEAR THE NORTH DAKOTA AND MANITOBA
BORDER. MUCH OF THE UPPER MIDWEST...INCLUDING THE NORTHLAND...HAD
COOL NORTHERLY FLOW WHICH WAS RESULTING IN PARTLY TO MOSTLY CLOUDY
SKIES ACROSS THE REGION. TEMPERATURES ACROSS THE NORTHLAND RANGED
FROM THE LOW 50S OVER THE TIP OF THE ARROWHEAD TO THE LOW TO MID
60S ACROSS MUCH OF THE REST OF THE NORTHLAND. THE BRAINERD LAKES
REGION HAD MID 60S TO LOW 70S. DEW POINT TEMPERATURES RANGED FROM
THE UPPER 30S OVER THE TIP OF THE ARROWHEAD...TO THE LOW TO MID
40S ACROSS THE REST OF THE NORTHLAND.
TONIGHT...THE HIGH PRESSURE IN THE NORTHERN PLAINS WILL MOVE OVER
THE NORTHLAND. THIS SHOULD RESULT IN AN OVERALL TREND IN CLEARING
SKIES AND DIMINISHING WIND WHICH WILL BE A RECIPE FOR A COLD NIGHT
ACROSS THE NORTHLAND. I BELIEVE OVERALL THE MODEL GUIDANCE IS
UNDERESTIMATING THE DEGREE OF RADIATIONAL COOLING TONIGHT...SO I
LEANED AND FORECASTED SLIGHTLY BELOW THE COLDEST GUIDANCE. FAR
NORTHERN MINNESOTA STILL LOOKS LIKE IT WILL BE THE COLDEST PART OF
THE FORECAST AREA AND WILL VERY LIKELY PLUMMET TO NEAR AND SUB
FREEZING TEMPERATURES. I MAINTAINED A FREEZE WARNING FOR THE IRON
RANGE AND INTERIOR ARROWHEAD...AS WELL AS THE FROST ADVISORY FOR
KOOCHICHING COUNTY...BUT ADDED NORTHERN ITASCA COUNTY TO THE FROST
ADVISORY. I STILL HAVE A LITTLE CONCERN ABOUT LINGERING CLOUD COVER
TONIGHT AND HOW IT MAY PREVENT TEMPERATURES FROM GETTING AS COLD
AS FORECAST. HOWEVER...LATEST HRRR MODEL RUNS ARE SHOWING PRETTY
GOOD CLEARING TONIGHT. THERE MIGHT BE A LITTLE LINGERING CLOUD
COVER HERE AND THERE...SUCH AS THE TIP OF THE ARROWHEAD...BUT I
THINK IT WILL HAVE LITTLE IMPACT TO THE FORECAST. I ADDED PATCHY
FROST TO OTHER PARTS OF THE NORTHLAND...SUCH AS PARTS OF THE SW
AND SE FORECAST AREA...BUT HELD OFF ON EXPANDING FROST ADVISORIES
TO THOSE AREAS SINCE THE TEMPERATURES LOOK TO BE BORDERLINE FOR
FROST. ALSO...THERE MAY BE LINGERING CLOUD COVER OVER PARTS OF NW
WISCONSIN DUE TO THE NORTH WINDS OFF LAKE SUPERIOR. THE EVENING
SHIFT WILL NEED TO MONITOR TRENDS AND RECONSIDER ADDING OTHER
PARTS OF THE FORECAST AREA TO THE FROST ADVISORY.
FRIDAY...THE HIGH PRESSURE WILL BEGIN TO SHIFT TOWARDS SOUTHERN
MINNESOTA AND IOWA. LIGHT SSW WINDS WILL DEVELOP ACROSS NE
MINNESOTA. SUNNY SKIES ARE EXPECTED WITH HIGHS IN THE MID TO UPPER
60S ACROSS MOST OF THE NORTHLAND...SAVE THE TIP OF THE ARROWHEAD
WHICH WILL SEE UPPER 50S TO LOW 60S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 322 PM CDT THU SEP 12 2013
FRIDAY NIGHT THE SURFACE RIDGE AND COLD TEMPERATURES SLIDE OFF TO
THE SOUTHEAST AND ALLOW SOUTHWEST RETURN FLOW TO BEGIN OVER THE
AREA. THIS CONTINUES...WITH GRADUALLY WARMING TEMPERATURES INTO
SATURDAY. ON SATURDAY A STRONG SHORTWAVE AND COLD FRONT PUSHES
INTO THE AREA FROM THE NORTHWEST. AT THE SAME TIME...A CUT OFF
UPPER LOW THAT HAS BEEN SITTING OVER THE SOUTHWEST CONUS THE LAST
FEW DAYS FINALLY GETS CAUGHT UP IN THE NORTHERN STREAM...AND
EJECTS OUT OVER THE PLAINS. THE RESULTING SYSTEM PULLS SOME
MOISTURE UP INTO OUR AREA...WITH A WARM FRONT THAT GETS AS FAR
NORTH AS SOUTH DAKOTA AND SOUTHERN MN SATURDAY NIGHT. THIS SHOULD
PRODUCE SOME SHOWERS AND ISOLATED THUNDER ACROSS OUR SOUTH
BEGINNING LATE SATURDAY AFTERNOON AND NIGHT...WITH SCATTERED
SHOWERS AND THUNDERSTORMS ALONG THE COLD FRONT SATURDAY NIGHT AND
EARLY SUNDAY. TEMPERATURES REMAIN MILD SOUTH OF THE FRONT...BUT
SATURDAY NIGHT MINS WILL RANGE FROM THE LOW TO MID 50S SOUTH...TO
THE MID 40S NORTH OF THE COLD FRONT.
SUNDAY TO BE MUCH COLDER AND DRIER WITH A SURFACE RIDGE BUILDING
ACROSS THE AREA...AND UPPER LEVEL RIDGING BUILDING AS WELL. SUNDAY
HIGHS ONLY RANGING FROM AROUND 60 NORTH TO THE MID 60S SOUTH.
SUNDAY NIGHT MINS COULD ONCE AGAIN BE COLD ENOUGH FOR
FROST...WITH MINS IN THE 30S TO AROUND 40.
THE UPPER LEVEL RIDGE SHIFTS OFF TO THE EAST BY EARLY IN THE
WEEK...ALLOWING A MORE SOUTHWEST FLOW SYSTEM TO ENTER THE AREA
MONDAY AND TUESDAY. A WAVE OF WARM AIR ADVECTION AND ISENTROPIC
LIFT MOVES INTO THE AREA BEGINNING MONDAY NIGHT...BRINGING A
CHANCE OF PRECIPITATION FOR MONDAY NIGHT THROUGH TUESDAY AND EVEN
EARLY WEDNESDAY. IT IS HARD TO SPECIFY ANY DRY PERIODS WITH THE
WARM MOIST AIR ADVECTION GOING ON ALOFT AND A WARM FRONT IN THE
VICINITY...THOUGH I AM SURE THERE WILL BE SOME. TEMPERATURES WILL
GRADUALLY WARM THROUGH WEDNESDAY. BY THURSDAY...THE SURFACE LOW
FINALLY BEGINS TO TAKE SHAPE IN THE PLAINS AND ADVANCES ACROSS
MINNESOTA DURING THE DAY. TRACK AND TIMING ARE STILL UNCERTAIN
WITH SOME SIGNIFICANT DIFFERENCES IN THE MODELS...BUT
PRECIPITATION CHANCES INCREASE AGAIN FOR THURSDAY WITH THE LOW IN
THE STATE AND PLENTY OF HEAT AND MOISTURE IN THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1240 AM CDT FRI SEP 13 2013
HIGH PRESSURE WILL BRING VFR CONDITIONS TO THE NORTHLAND THROUGHOUT
THE TAF PERIOD. THE EXCEPTIONS WILL BE SOME PATCHY FOG
OVERNIGHT...WHICH COULD RESULT IN LOCAL IFR/MVFR.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 48 71 54 63 / 0 20 30 10
INL 49 74 44 61 / 0 30 20 10
BRD 49 71 54 66 / 0 30 40 10
HYR 43 71 51 64 / 0 10 30 10
ASX 47 72 52 61 / 0 10 40 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...FREEZE WARNING UNTIL 8 AM CDT THIS MORNING FOR MNZ011-012-019.
FROST ADVISORY UNTIL 8 AM CDT THIS MORNING FOR MNZ010-018.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...DAP
SHORT TERM...GROCHOCINSKI
LONG TERM...LE
AVIATION...DAP
AREA FORECAST DISCUSSION
NWS JACKSON MS
345 AM CDT FRI SEP 13 2013
.DISCUSSION...
TODAY THROUGH SUNDAY MORNING
A WEAK COOL FRONT PASSAGE TODAY WILL AID IN ISOLATED TO SCATTERED
SHOWER DEVELOPMENT THIS MORNING THROUGH TONIGHT. A MUCH DRIER,
COOLER, AND QUITE COMFORTABLE AIRMASS WILL SETTLE IN FOR THE
WEEKEND.
THE AFOREMENTIONED COOL FRONT IS ANALYZED ALONG A NASHVILLE, TN TO
DYER, TN TO NORTH OF A LITTLE ROCK, AR LINE AT 08Z THIS MORNING.
THIS FRONT IS BEING DRIVEN BY A DEEPENING L/WV TROUGH ACROSS THE
EASTERN SEABOARD AND A STRENGTHENING SFC HIGH ACROSS THE UPPER
MIDWEST. AHEAD OF THIS FRONT HOWEVER, IS A PREFRONTAL TROUGH AND
ASSOCIATED H5 PVA RIBBON PER RAP ANALYSIS. THE TRAILING PREFRONTAL
TROUGH AXIS EXTENSION FROM THE NE CONUS HAS ALLOWED TO KICK OFF A
FEW SHOWERS EARLY THIS MORNING ACROSS FAR N/NE MS. THIS VERY
ISOLATED AND TRANSIENT ACTIVITY WILL FESTER THROUGH THE MORNING AND
WILL MOVE SOUTH IN CONJUNCTION WITH THE H5 PVA RIBBON. BY MID TO
LATE MRNG, THE FRONT SHOULD BE ON HWY-82 CORRIDOR DOORSTEP NORTH OF
THIS H5 RIBBON, AND THUS WILL MAINLY RELY ON INSTABILITY FACTORS FOR
PARCEL BUOYANCY VS. ANY DYNAMIC LIFT MECHANISM. ISOLATED SHOWERS
SHOULD GET GOING BETWEEN HWY-82 AND I-20 LATE MRNG/EARLY AFTN WITH
BETTER COVERAGE EXPECTED NEAR AND SOUTH OF I-20 BY MID AFTN AS SFC
BASED INSTABILITY BUILDS UPWARDS TO 1200 J/KG. SOME THUNDERSTORMS
MAY DEVELOP BUT WITH MEAGER INSTABILITY, WEAK LOW-LVL CONVERGENCE
AND POOR LAPSE RATES, NOT EXPECTING ANY STRONG THUNDERSTORMS NOR
MODEST LIGHTNING PRODUCERS. WENT WELL ABOVE MAV POPS AGAIN TOWARDS
MET NUMBERS IN THE 20-30% RANGE ACROSS THE REGION TODAY BUT BROKE UP
DAY TO INDICATE SHOWER PROBS DECREASING NORTH TO SOUTH THROUGH TIME.
SKIES WILL CLEAR THROUGH THE OVERNIGHT WITH THE FRONT PUSHING
THROUGH THE REGION TO THE SOUTH SATURDAY MRNG. SFC DEWPOINTS IN THE
LOW 50S NORTH TO NEAR 60 SOUTH WILL DROP HUMIDITY LEVELS AND MAKE IT
FEEL QUITE COMFORTABLE TO BE OUTSIDE THROUGH THE DAY. HIGHS SATURDAY
WILL TOP OUT IN THE LOW 80S NORTH TO UPPER 80S SOUTH, SOME 10-13F
DEGREES COOLER FROM THIS PAST WEEK. LOWS SATURDAY AND SUNDAY WILL
RANGE FROM THE MID 50S NORTH TO THE MID 60S SOUTH. /ALLEN/
SUNDAY THROUGH NEXT FRIDAY
NUMERICAL MODELS CONTINUE TO BE IN SOLID AGREEMENT ON
THE MED RANGE/LONG TERM. THE GENERAL PATTERN WILL CONTINUE TO BE ONE
OF RIDGING ALOFT...ALBEIT WEAKER THAN WHAT WE HAVE BEEN SEEING...AND
STEADY MOISTENING AS WE GO THROUGH THE WORK WEEK.
THE COOL FRONT WILL WASH OUT ON SUNDAY AND ALLOW FOR A DECENT WARM
UP ALONG WITH ALLOWING BETTER LOW LEVEL MOISTURE TO RETURN ACROSS
THE S HALF OF THE CWA. WHILE NOT MUCH SHOWER ACTIVITY IS
EXPECTED...CAN`T RULE OUT AN ISOLATED SHOWER ACROSS THE HWY 84
CORRIDOR BY AFTERNOON. THE PATTERN WILL STEADILY TRANSITION THROUGH
MIDWEEK AND BECOME ONE WITH A MORE DEEP SE FLOW. THIS WILL RESULT IN
ALLOWING MORE DEEP TROPICAL MOISTURE INTO THE REGION ALONG WITH SOME
WEAKENING OF THE SUBTROPICAL RIDGE. THE RESULT WILL BE BETTER PRECIP
CHANCES FOR MID/LATE WEEK. THIS MAY BE THE BEGINNING OF A WETTER
PATTERN TO END THE MONTH. WE WILL SEE IF THE MODELS CONTINUE TO SHOW
THIS OVER THE NEXT FEW RUNS.
AS FOR TEMPS...GFS GUIDANCE SEEMS TO HAVE A SOLID HANDLE ON EXPECTED
CONDITIONS. MODERATION WILL BE THE WORD FOR SUN-MON AS THE AREA
WARMS BACK INTO THE 90-95 DEGREE RANGE AGAIN. BY MID WEEK...DEEPER
MOISTURE...MORE CLOUDS AND INCREASED RAIN POTENTIAL WILL TAPER TEMPS
BACK TOWARD NORMAL. /CME/
&&
.AVIATION...VFR CONDS PREVAIL THIS MRNG BUT SOME PATCHY MVFR FOG
MAY STILL BE PSBL THROUGH 14Z FOR KMEI/KHBG. VFR CONDS EXPECTED TO
PREVAIL THROUGH THE DAY BUT ISO/SCT SHRA EXPECTED TO DEVELOP ACROSS
REGION AS WEAK COLD FRONT MOVES THROUGH THE REGION. WINDS WILL BE
LIGHT AND NORTHERLY AHEAD OF THE COLD FRONT AND THEN PICK UP TO
10-12KT FROM THE SAME DIRECTION AS THE FRONT PASSES THIS AFTN FROM
NORTH TO SOUTH. WINDS WILL STAY UP AROUND 5 KTS THROUGH THE OVRNGT
SAT MRNG. /ALLEN/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 93 62 85 60 / 27 6 0 0
MERIDIAN 93 59 86 57 / 27 7 0 0
VICKSBURG 93 61 87 59 / 27 7 0 0
HATTIESBURG 96 64 90 64 / 27 16 5 4
NATCHEZ 93 64 86 64 / 27 15 4 4
GREENVILLE 90 59 83 57 / 18 0 0 0
GREENWOOD 89 56 84 55 / 19 0 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
ALLEN/CME
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
340 AM CDT FRI SEP 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT FRI SEP 13 2013
TODAY AND TONIGHT...THE MODELS APPEAR TO BE TOO FAST AND AGGRESSIVE
LIFTING THE AREA OF RAIN ACROSS NWRN KS/NERN COLO THROUGH THE FCST
AREA TODAY AND TONIGHT. SO THE FORECAST SLOWS THIS BY 3 HOURS WHICH
MAY NOT BE ENOUGH. OTHERWISE...THE CLOUD SHIELD ACROSS SWRN NEB
SHOULD SPREAD SLOWLY NORTH TODAY AND TONIGHT. THE FORECAST ATTEMPTS
TO MARK UP TEMPS FOR WARMER HIGHS AS THE CLOUDS AND RAIN WILL LIKELY
BE DELAYED BY SEVERAL HOURS AND MAY NOT REACH INTERSTATE 80 UNTIL
LATE THIS AFTERNOON.
MODEL BLENDED QPF PRODUCED AROUND 1/3 OF AN INCH ACROSS SWRN NEB TO
0.05 INCHES ACROSS ERN ZONES. THE RAP MODEL LIFTS THE RAIN NORTH
VERY QUICKLY AND DRIES IT OUT AT THE SAME TIME WHICH IS LIKELY A
RESULT OF DRY AIR AT THE LOWER LEVELS. THE HRRR MODEL IS WAY TOO
FAST AND A PLUME OF ALL MODEL SOLNS FOR NORTH PLATTE SHOW A VERY
WIDE SPREAD OF QPF TOTALS FROM 1/3 OF AN INCH TO A TRACE. THUS THE
RAIN CHANCES ACROSS MUCH THE FCST AREA EXCEPTING FAR SWRN NEB ARE
UNCERTAIN.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 340 AM CDT FRI SEP 13 2013
FORECAST CONFIDENCE REMAINS AVERAGE THROUGH THE WEEKEND WITH
DECENT CONSISTENCY DISPLAYED FROM THE LONG RANGE SOLUTIONS. FOR
SATURDAY...RAIN CHANCES DO NOT APPEAR TO BE AS WIDESPREAD AS THE
BULK OF THE QG FORCING AND ASSOCIATED WEAKENING UPPER LEVEL LOW IS
DIRECTED TO THE NORTH AND WEST OF THE CWA...BUT INCREASING
ATMOSPHERIC INSTABILITY WITH SUFFICIENT MOISTURE WOULD ALLOW FOR
AT LEAST A CONTINUED MENTION OF STORMS THROUGH THE DAY. BETTER
CHANCES HOWEVER APPEAR TO ARRIVE LATE SATURDAY INTO EARLY SUNDAY
AS A WEAK DISTURBANCE WORKS ON A PASSING FRONTAL BOUNDARY...SHOWER
AND THUNDERSTORM CHANCES WILL REMAIN HIGHEST ALONG OUR SOUTHERN
AND EASTERN BORDERS AS THE FRONT SETTLES ACROSS KANSAS. WITH HIGH
PRESSURE BUILDING SOUTH ACROSS THE NORTHERN HIGH PLAINS AND INTO
THE UPPER MISSISSIPPI RIVER VALLEY ON SUNDAY...DRIER CONDITIONS
ARE ANTICIPATED FOR MUCH OF THE REGION. THERE WILL BE A SHARP
DIVIDING LINE HOWEVER AS A CONTINUED TAP OF MOIST MONSOONAL AIR
DRIVES NORTH THROUGH THE SOUTHERN PLAINS. A RECENT TREND OF THE
LONGER RANGE SOLUTIONS IS TO SETTLE THE FRONT FURTHER SOUTH ACROSS
SOUTHERN/CENTRAL KANSAS WITH DRIER AIR /VOID OF PRECIPITATION/
ACROSS MOST IF NOT ALL LOCATIONS ACROSS THE CWA. DID NOT WANT TO
ENTIRELY PULL POPS YET ON SUNDAY AND INTO MONDAY...THUS WILL LOWER
TO A SLIGHT CHANCE MENTION FOR MOST PLACES...BUT FEEL WE COULD GO
LOWER YET. WITH THE DRIER AIR WORKING SOUTH...CONDITIONS WILL BE
PLEASANTLY COOL ON SUNDAY...WITH HIGHS TOPPING OUT IN THE UPPER
60S TO LOW 70S. LOOKING AHEAD TO EARLY NEXT WEEK...THE MODEL
CONSENSUS DEVELOPS A BROAD RIDGE ACROSS THE CENTRAL CONUS WITH
PERIODIC SHORTWAVES SUPPRESSING ITS STRENGTH. A GENERAL WARMING
TREND IS THEN SHOWN...WITH HIGHS RETURNING BACK INTO THE 80S AS
EARLY AS TUESDAY...AND LOWS FALLING INTO THE UPPER 50S FOR MOST
PLACES. PERIODIC STORM CHANCES ARE IN STORE FOR NEXT WEEK...MAINLY
ACROSS EASTERN PORTIONS OF THE CWA AS A FRONT STALLS AND PERIODIC
WAVES PASS THROUGH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1250 AM CDT FRI SEP 13 2013
SHOWERS AND THUNDERSTORMS IN SOUTHWEST NEBRASKA ARE EXPECTED TO
REMAIN SOUTH OF AN OGA-LXN LINE TONIGHT THROUGH AT LEAST LATE FRIDAY
MORNING. CEILING IN THAT AREA OF NEBRASKA TONIGHT WILL CONTINUE TO
BE BELOW 3000 FEET AGL AND MAY GO BELOW 1000 FEET AGL. SOME CEILINGS
AT OR BELOW 4000 FEET AGL ARE EXPECTED TO REACH LBF AND MHN BY
12Z...BUT IT IS UNLIKELY THAT THEY WILL BE ANY LOWER THAN 4000 FEET.
SHOWERS AND THUNDERSTORMS WILL SPREAD NORTHEAST INTO SOUTHWEST
NEBRASKA THROUGH THE DAY FRIDAY...BUT THEY WILL PROBABLY NOT REACH
MHN-LBF UNTIL 00Z OR LATER. AFTER 00Z...THE PROBABILITY FOR LBF IS
EXPECTED TO BE 40-45 PERCENT. WITH MODERATE CONFIDENCE SUCH AS
THAT...WE BELIEVE THAT A MENTION OF AT LEAST VCTS IS WARRANTED FOR
THE LBF TERMINAL FORECAST.
BEYOND 06Z SATURDAY...THE SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
MOVE ACROSS CENTRAL AND NORTH CENTRAL NEBRASKA AND WILL PROBABLY
AFFECT VTN...ANW...ONL AND BBW AFTER 06Z SATURDAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
115 AM EDT FRI SEP 13 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA FRIDAY MORNING. CANADIAN HIGH
PRESSURE WILL BRING FALL-LIKE WEATHER THIS WEEKEND. A SECOND
CANADIAN HIGH WILL DROP SOUTHEAST INTO THE REGION EARLY NEXT
WEEK...BRINGING A REINFORCEMENT OF DRY AND MILD AIR FOR MUCH OF
THE UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 130 AM FRIDAY...RADAR SHOWS VIRTUALLY NO SHOWER ACTIVITY
ACROSS THE EASTERN CAROLINAS AT THIS TIME. LATEST FEW HRRR RUNS ARE
INCONSISTENT WITH THEIR PLACEMENT OF ANY SHOWERS BETWEEN NOW AND
SUNRISE LEADING TO VERY LOW CONFIDENCE THAT WE WILL HAVE
SHOWERS...AND IF SO WHERE. SLIGHT CHANCE (20 PERCENT) APPEARS TO BE
THE WAY TO GO. TEMPERATURES WILL REMAIN QUITE WARM FOR THE DATE
OVERNIGHT WITH THE PERSISTENT SOUTHWEST WIND. PREVIOUS DISCUSSION
FROM 1000 PM FOLLOWS...
TAIL END OF MID LEVEL SUBSIDENCE ACROSS THE FA THIS EVENING HAS KEPT
A TEMPORARY LID ON CONVECTIVE DEVELOPMENT. IE. NO TSRA/SHRA
DEVELOPMENT ALONG THE AFTERNOON/EVENING SEA BREEZE. THE SUBSIDENCE
LIES BETWEEN THE EXITING S/W TROF...WHAT WAS ONCE AN UPPER LOW OFF
THE SE U.S. COAST...OVER THE ADJACENT ATL WATERS AND THE APPROACHING
S/W TROF FROM THE WEST. FORCING/DYNAMICS FROM THIS UPPER S/W TROF
AND FORCING AHEAD OF THE APPROACHING SFC COLD FRONT...WILL BE ENOUGH
TO CONTINUE LOW CHANCE POPS ACROSS PORTIONS OF THE FA DURING THE
PRE-DAWN FRIDAY HOURS. LEFT OUT THUNDER FOR THE TIME BEING DUE TO
VERY LIMITED AVBL CAPE GIVEN THE TIME OF DAY. CURRENT MIN TEMP
FORECAST LOOKS AOK...WITH CONTINUED TWEAKING OF THE HOURLY SFC
DEWPOINTS BASED ON LATEST OBS/TRENDS.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
AS OF 3 PM THURSDAY...DIGGING MID TO UPPER TROUGH EXTENDING DOWN
FROM THE GREAT LAKES WILL PUSH A COLD FRONT THROUGH THE AREA ON
FRIDAY. LATEST MODELS SHIFT THE BOUNDARY TO THE CAPE FEAR COAST
THROUGH FRI MORNING...BUT LOOKS LIKE WINDS WILL BACK AS SEA BREEZE
DEVELOPS. THIS WILL PRODUCE ENOUGH CONVERGENCE ALONG THE COAST
ALONG WITH ENOUGH LINGERING MOISTURE TO PRODUCE CLOUDS. WILL LEAVE
SOME CONVECTION POSSIBLE THROUGH EARLY AFTERNOON...BUT DRY COOL
AIR WILL PUSH IN BEHIND THE FRONT ADVECTING FROM NORTHWEST TO
SOUTHEAST AS WINDS SHIFT AROUND TO THE WEST-NORTHWEST BEHIND THE
FRONT. DEWPOINT TEMPS WILL DROP A GOOD 5 DEGREES THROUGH FRI
AFTERNOON. THIS COOL CANADIAN HIGH PRESSURE WILL BUILD INTO THE
AREA OVER THE WEEKEND PRODUCING UNSEASONABLY COOL AND DRY WEATHER.
THE MID TO UPPER TROUGH ACTUALLY BECOMES A BIT BROADER OVER THE
SOUTHEAST AS IT MOVES SLOWLY ACROSS TO NEW ENGLAND LATE FRI
THROUGH EARLY SAT. THIS WILL KEEP WINDS MORE WESTERLY IN THE MID TO
UPPER LEVELS THROUGH EARLY SATURDAY. A MORE SUBSTANTIAL PUSH OF
DEEP COOL AND DRY AIR WILL DEVELOP AS THIS H5 TROUGH CLEARS THE
COAST ON SATURDAY. EXPECT INLAND AREAS TO EXPERIENCE COOLER AND
DRIER CONDITIONS INITIALLY THROUGH LATE FRI BUT THIS SECONDARY
PUSH ON SAT WILL KEEP TEMPS BELOW 80 IN SPOTS ON SAT AND TEMPS
WILL DROP INTO THE LOWER 50S OVER PORTIONS OF CWA SAT NIGHT.
MOISTURE TRAPPED UNDER SUBSIDENCE INVERSION ON SATURDAY WILL
PRODUCE SOME CLOUDS...ESPECIALLY CLOSE TO THE COAST. THIS WILL
ALSO HELP TO LIMIT HEATING. THE COMBINATION OF CAA AND CLOUD
DEVELOPMENT WILL KEEP TEMPS A GOOD 5 TO 10 DEGREES COOLER THAN
PREVIOUS DAYS AND THE DRIER AIR WILL MAKE IT FEEL EVEN COOLER.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...WEAK RIDGING ALOFT AT THE START OF THE PERIOD
WILL SLOWLY BREAK DOWN NEXT WEEK. SURFACE HIGH OVERHEAD ON SUN WILL
YIELD TO A WEAK COLD FRONT MOVING IN FROM THE NORTH LATE MON OR
EARLY TUE. AHEAD OF THE FRONT LIGHT RETURN FLOW AND A BUMP IN LOW
LEVEL MOISTURE COULD PRODUCE ISOLATED SHOWERS MON AFTERNOON...MAINLY
NEAR THE COAST. WILL NOT CARRY A ZERO POP BUT WILL KEEP POP 10 OR
LESS. COOLER AND DRIER HIGH PRESSURE WILL BUILD IN FROM THE NORTH
BEHIND THE FRONT. LIMITED MOISTURE ALONG THE FRONT AND LACK OF
FORCING...INSTABILITY AND MID LEVEL SUPPORT SUGGESTS THE FRONT WILL
BE LITTLE MORE THAN A WIND SHIFT WITH LIMITED CLOUD COVER. HIGH
SLOWLY SHIFTS EAST NEXT WEEK...EVENTUALLY MOVING OFF THE MID
ATLANTIC COAST WED/THU. NORTHERLY FLOW TUE INTO WED WILL KEEP
TEMPERATURES NEAR TO SLIGHTLY BELOW CLIMO AND LIMIT PRECIP CHANCES.
DEVELOPING RETURN FLOW LATE NEXT WEEK LEADS TO A SLIGHT INCREASE IN
MOISTURE. LOW LEVEL MOISTURE IN CONCERT WITH WEAKENING MID LEVEL
SUBSIDENCE MAY ALLOW FOR DEVELOPMENT OF SOME DEEPER CONVECTION. FOR
NOW WILL MAINTAIN INHERITED SILENT POP WED/THU.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...A COLD FRONT OVER THE WESTERN CAROLINAS WILL CONTINUE
APPROACHING THE AREA THIS MORNING. SURFACE WINDS 4-8 KTS WILL KEEP
THE BOUNDARY LAYER MIXED...SO DO NOT ANTICIPATE ANY FOG ISSUES. HAVE
INCLUDED VCSH THIS MORNING AS HI-RES GUIDANCE STILL SHOWS SOME
ISOLATED SHRA DEVELOPING AS THE FRONT APPROACHES. BY MIDDAY THE
FRONT SHOULD PUSH THROUGH OUR AREA...AND THE WINDS WILL VEER TO THE
NORTH OR NORTHWEST. THE GFS AND NAM CONTINUE TO HINT AT SOME
SHOWERS/T-STORMS ALONG THE COAST DURING THE AFTN HOURS...AS SFC
CONVERGENCE ALONG THE SEA BREEZE PROMOTES SHOWER DEVELOPMENT. DEEP
CONVECTION WILL BE TOUGH GIVEN THE DRIER AIR ALOFT AND THE MID-LEVEL
INVERSION...BUT HAVE ADDED VCSH FOR THE AFTN AT KILM/KCRE/KMYR AS
SHOWERS CANNOT BE RULED OUT. AFTER 21Z...PCPN ACTIVITY WILL REMAIN
OFFSHORE AND THE SKIES SHOULD BEGIN CLEARING OUT.
EXTENDED OUTLOOK...VFR WILL PREVAIL THROUGH THE EXTENDED PERIOD.
VERY SLIGHT CHANCE OF SHOWERS LATE MONDAY INTO EARLY TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM FRIDAY...WINDS ARE A FEW KNOTS STRONGER THAN PREVIOUSLY
FORECAST BUT SEAS ARE RUNNING ABOUT 1 FOOT LESS AWAY FROM SHORE.
THIS ADDS UP TO SMALL CHANGES OVERALL. PREVIOUS DISCUSSION FROM 1000
PM FOLLOWS...
THE SFC PG HAS FINALLY BEGUN TO TIGHTEN ACROSS THE FA...AHEAD OF THE
APPROACHING COLD FRONT. THE LATEST OBS IE. OCPN7 AND
41013...INDICATE SW 10-15 KT WITH GUSTS UP TO 17 KT. THE LATEST HRRR
CONTINUES TO ILLUSTRATE SUSTAINED WINDS APPROACHING 20 KT OVERNIGHT.
WILL NOT GO TO THAT EXTREME BUT WILL INDICATE INCREASING TO
SUSTAINED AROUND 15 KT...WITH GUSTS UP TO 20 KT. SFC PRESSURE
PATTERN AHEAD OF THE COLD FRONT TO YIELD A SW DIRECTION THIS
EVENING...BECOMING WSW TOWARD DAYBREAK AS THE FRONT MOVES IN CLOSER
PROXIMITY. SIGNIFICANT SEAS OF 2 TO 3 FT THRUOUT THIS EVENING...WITH
4 FOOTERS POSSIBLE ACROSS THE OUTER WATERS OFF CAPE FEAR AND THE
EASTERN PORTIONS OF AMZ252...IE. EAST OF HOLDEN BEACH...DURING THE
FRI AM HOURS. THE 8 TO 9 SECOND PERIOD EASTERLY GROUND SWELL WILL
DOMINATE THIS EVENING...HOWEVER THERE WILL BE AN INFLUX/INCREASE OF
3 TO 6 SECOND PERIOD WIND DRIVEN WAVES...MAINLY AFTER MIDNIGHT.
HENCE...THE 4 FOOTERS.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 PM
THURSDAY...COLD FRONT WILL DROP SOUTHEAST INTO THE WATERS ON
FRIDAY BUT WINDS WILL BACK SOME THROUGH THE DAY AS SEA BREEZE
DEVELOPS. THEN BY NIGHTFALL...WINDS WILL SWING AROUND TO THE
NORTHEAST UP TO 10 TO 15 KTS AS BOUNDARY PUSHES SOUTH. EXPECT A
SURGE OF COOLER AND DRIER AIR ADVECTING IN AS COOL CANADIAN HIGH
PRESSURE BUILDS INTO AREA BEHIND THE FRONT.
EXPECT A SECONDARY PUSH OF COOL AND DRY AIR ON SAT AS MID TO
UPPER TROUGH SWINGS OFF THE COAST AND HIGH PRESSURE CONTINUES TO
BUILD SOUTH PRODUCING A DEEPER DRIER AND COOLER NORTHERLY FLOW.
THIS SECONDARY SURGE SHOULD PRODUCE WINDS UP TO 15 TO 20 KTS WITH
HIGHER GUSTS LATE SATURDAY INTO EARLY SUNDAY. SEAS WILL INCREASE
FROM 2 TO 3 FT EARLY FRI TO 3-5 FEET FRI NIGHT INTO SATURDAY AS
WINDS INCREASE. LATEST WNA MODELS SHOW SEAS PEAKING AROUND 5 FT
POSSIBLY WARRANTING A SCEC HEADLINE...BUT THE SEAS COULD END UP BEING
HIGHER IF SURGE PRODUCES GREATER WINDS IN WELL MIXED ATMOSPHERE DUE
TO WARMER WATERS THIS TIME OF YEAR.
LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 3 PM THURSDAY...NORTHEAST FLOW BETWEEN 10 AND 15 KT AT THE
START OF THE PERIOD WILL VEER TO EASTERLY AS HIGH TO THE NORTH
SHIFTS EAST. LITTLE CHANGE TO THE GRADIENT IS EXPECTED AND WINDS ARE
LIKELY TO REMAIN 10 TO 15 KT THROUGH SUN. WEAK EAST TO SOUTHEAST
FLOW DEVELOPS MON AS HIGH MOVES FARTHER OFFSHORE. SPEEDS AROUND 10
KT AND SOUTHERLY COMPONENT WILL BE SHORT LIVED. LATE MON/EARLY TUE A
COLD FRONT MOVES SOUTH ACROSS THE WATERS FOLLOWED BY HIGH PRESSURE
BUILDING IN FROM THE NORTHWEST. NORTH TO NORTHEAST FLOW DEVELOPS
WITH SPEEDS A SOLID 15 KT TUE. SEAS START OUT 3 TO 4 FT BUT DROP TO
2 TO 3 FT FOR MON AS WIND SPEEDS DECREASE. INCREASING NORTHEAST FLOW
MON NIGHT AND TUE WILL PUSH SEAS BACK TO 2 TO 4 FT BY THE END OF THE
PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...DCH/TRA
SHORT TERM...RGZ
LONG TERM...III
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
230 AM EDT FRI SEP 13 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO PUSH SOUTHEAST AND OFF THE MID
ATLANTIC COAST LATER TONIGHT. ANOTHER TASTE OF FALL WILL ARRIVE
IN THE WAKE OF THIS FRONT...WITH BELOW NORMAL TEMPERATURES
EXPECTED FROM FRIDAY THROUGH THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
MESO ANAL INDICATES THE COLD FRONT IS ALL BUT CLEAR OF MY SERN
ZONES...WHERE DEWPOINTS ARE STILL HIGH BUT WILL BEGIN DROPPING
OFF OVER THE NEXT FEW HOURS. A WEAK SECONDARY SHORTWAVE IS EVIDENT
ON WATER VAPOR ENTERING NWRN PA...AND IS TRIGGERING SOME LIGHT
SHOWER ACTIVITY. HRRR AND RAP SHOW THESE SHOWERS CONTINUING TO
SLIDE EAST...WHILE TENDING TO DIMINISH IN COVERAGE SOUTH OF ABOUT
RTE-80 AND EAST OF THE LAURELS.
OVERALL WE WILL KEEP A FAIR AMOUNT OF CLOUDS. IT WILL BE BREEZY
WITH SCATTERED SHOWERS...MAINLY OVER WESTERN AREAS. STRONG COLD
ADVECTION WHICH WILL ALLOW TEMPS TO DROP INTO THE 40S IN THE N AND
50S MOST ELSEWHERE.
THE INSTABILITY SHOULD DRIVE ADDITIONAL SHOWERS AND PERHAPS THUNDER
OVER THE ALLEGHENIES - BUT WILL LEAVE THUNDER OUT FOR NOW. TEMPS
WON/T RISE MUCH ON FRI...WITH THE NEG TEMP ADV AND CLOUDS IN THE
NWRN 1/2 TO 2/3RDS OF THE AREA. EXPECT HIGHS ONLY IN THE LOWER/MID
50S IN BRADFORD AND UPPER 50S IN THE LAURELS. THE TEMPS WILL BE MORE
NORMAL IN THE DOWNSLOPE OF THE SE. GUSTY WINDS WILL MAKE IT FEEL
EVEN MUCH COOLER.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/...
THERE WILL BE THE POTENTIAL FOR AT LEAST PATCHY FROST OVER THE
NORMALLY COLD NORTH TONIGHT. BIGGEST QUESTION IS IF CLOUDS CAN
BREAK IN TIME. FCST SOUNDINGS CONFLICT ON THIS WITH THE GFS
SHOWING LOW LEVEL MOISTURE HANGING TOUGH...AND THE NAM SHOWING
CLEARING IN THE 06-09Z TIMEFRAME. WILL PROBABLY MENTION PATCHY
FROST LATE...BUT LEAN AWAY FROM HEADLINES AT THIS POINT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
GENERALLY WESTERLY FLOW ALOFT THROUGH THE LONG TERM PERIOD WILL
CONTINUE MAINLY RAIN FREE CONDITIONS THROUGH THE PERIOD...WITH TWO
LARGE AREAS OF HIGH PRESSURE MOVING SOUTHEAST OUT OF CENTRAL
CANADA AND ACROSS PA DURING THE NEXT WEEK.
A WEAK COLD FRONT IS PROGGED TO MOVE THROUGH ON MONDAY BETWEEN
THE HIGH CENTERS...BUT GUIDANCE CONTINUES TO SUGGEST THAT IT WILL
BE MOISTURE STARVED AND KEPT POPS MINIMAL. THE HIGHEST CHANCE OF
PCPN IN THE LONG TERM PERIOD IS AT THE END OF THE PERIOD WHEN HIGH
PRESSURE MOVES OFF THE EAST COAST AHEAD OF LOW PRESSURE EXPECTED TO
FORM OVER THE NORTHERN PLAINS. RETURN FLOW ON THE BACK SIDE OF THE
HIGH WILL ALLOW A FLOW OF MOISTURE ENOUGH TO INCLUDE ISOLD/SCT
POPS INTO THE GRIDS FOR NEXT THURS.
ALSO NOTABLY...TEMPERATURES WILL DROP BACK TO BELOW NORMAL LEVELS.
HIGH TEMPERATURES WILL BE IN THE 60S AND 70S ON SUNDAY THROUGH
MUCH OF THE PERIOD.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
COLD FRONT HAS PUSHED SE OF PENNSYLVANIA AS OF 06Z AND A DRIER NW
FLOW IS TAKING HOLD. REGIONAL RADAR LOOP AT 06Z SHOWS AN AREA OF
SHOWERS ENTERING WESTERN PA IN ASSOCIATION WITH AN UPPER LVL
DISTURBANCE. THESE SHOWERS WILL LIKELY AFFECT JST BTWN
08Z-11Z...THEN FALL APART AS THEY PUSH EAST OF THE MTNS. THE
BIGGEST AVIATION CONCERN OVERNIGHT WILL BE RESIDUAL LOW LVL MOISTURE
ASCENDING THE W MTNS AND CAUSING SOME LOW CIGS. LATEST MDL
SOUNDINGS SUPPORT THE LIKELIHOOD OF IFR CIGS AT BFD AND
POSSIBILITY OF IFR CIGS AT JST LATER THIS AM.
HEATING OF BLYR WILL CAUSE CIGS TO RISE LATE THIS MORNING...WITH
VFR CONDS EXPECTED EVEN ACROSS THE W MTNS BY AFTN. ONLY AVIATION
CONCERN THIS AFTN WILL BE THE GUSTY NW WINDS CAUSED BY TIGHT PRES
GRADIENT BTWN LOW OVR NEW ENG AND HIGH PRES OVR THE MIDWEST.
BUFKIT SOUNDINGS SUPPORT FREQUENT GUSTS IN THE 15-20KT RANGE. THE
WIND WILL DIMINISH TONIGHT...AS HIGH PRES APPROACHES FROM THE
MIDWEST.
OUTLOOK...
SAT...NO SIG WX EXPECTED.
SUN...PATCHY AM FOG POSSIBLE.
MON...EARLY AM LOW CIGS POSS AT BFD.
TUE...PATCHY AM FOG POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...CERU/GARTNER
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
134 AM EDT FRI SEP 13 2013
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO PUSH SOUTHEAST AND OFF THE MID
ATLANTIC COAST LATER TONIGHT. ANOTHER TASTE OF FALL WILL ARRIVE
IN THE WAKE OF THIS FRONT...WITH BELOW NORMAL TEMPERATURES
EXPECTED FROM FRIDAY THROUGH THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
MESO ANAL INDICATES THE COLD FRONT IS ALL BUT CLEAR OF MY SERN
ZONES...WHERE DEWPOINTS ARE STILL HIGH BUT WILL BEGIN DROPPING
OFF OVER THE NEXT FEW HOURS. A WEAK SECONDARY SHORTWAVE IS EVIDENT
ON WATER VAPOR ENTERING NWRN PA...AND IS TRIGGERING SOME LIGHT
SHOWER ACTIVITY. HRRR AND RAP SHOW THESE SHOWERS CONTINUING TO
SLIDE EAST...WHILE TENDING TO DIMINISH IN COVERAGE SOUTH OF ABOUT
RTE-80 AND EAST OF THE LAURELS.
OVERALL WE WILL KEEP A FAIR AMOUNT OF CLOUDS. IT WILL BE BREEZY
WITH SCATTERED SHOWERS...MAINLY OVER WESTERN AREAS. STRONG COLD
ADVECTION WHICH WILL ALLOW TEMPS TO DROP INTO THE 40S IN THE N AND
50S MOST ELSEWHERE.
THE INSTABILITY SHOULD DRIVE ADDITIONAL SHOWERS AND PERHAPS THUNDER
OVER THE ALLEGHENIES - BUT WILL LEAVE THUNDER OUT FOR NOW. TEMPS
WON/T RISE MUCH ON FRI...WITH THE NEG TEMP ADV AND CLOUDS IN THE
NWRN 1/2 TO 2/3RDS OF THE AREA. EXPECT HIGHS ONLY IN THE LOWER/MID
50S IN BRADFORD AND UPPER 50S IN THE LAURELS. THE TEMPS WILL BE MORE
NORMAL IN THE DOWNSLOPE OF THE SE. GUSTY WINDS WILL MAKE IT FEEL
EVEN MUCH COOLER.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM SATURDAY/...
THERE WILL BE THE POTENTIAL FOR AT LEAST PATCHY FROST OVER THE
NORMALLY COLD NORTH TONIGHT. BIGGEST QUESTION IS IF CLOUDS CAN
BREAK IN TIME. FCST SOUNDINGS CONFLICT ON THIS WITH THE GFS
SHOWING LOW LEVEL MOISTURE HANGING TOUGH...AND THE NAM SHOWING
CLEARING IN THE 06-09Z TIMEFRAME. WILL PROBABLY MENTION PATCHY
FROST LATE...BUT LEAN AWAY FROM HEADLINES AT THIS POINT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
GENERALLY WESTERLY FLOW ALOFT THROUGH THE LONG TERM PERIOD WILL
CONTINUE MAINLY RAIN FREE CONDITIONS THROUGH THE PERIOD...WITH TWO
LARGE AREAS OF HIGH PRESSURE MOVING SOUTHEAST OUT OF CENTRAL
CANADA AND ACROSS PA DURING THE NEXT WEEK.
A WEAK COLD FRONT IS PROGGED TO MOVE THROUGH ON MONDAY BETWEEN
THE HIGH CENTERS...BUT GUIDANCE CONTINUES TO SUGGEST THAT IT WILL
BE MOISTURE STARVED AND KEPT POPS MINIMAL. THE HIGHEST CHANCE OF
PCPN IN THE LONG TERM PERIOD IS AT THE END OF THE PERIOD WHEN HIGH
PRESSURE MOVES OFF THE EAST COAST AHEAD OF LOW PRESSURE EXPECTED TO
FORM OVER THE NORTHERN PLAINS. RETURN FLOW ON THE BACK SIDE OF THE
HIGH WILL ALLOW A FLOW OF MOISTURE ENOUGH TO INCLUDE ISOLD/SCT
POPS INTO THE GRIDS FOR NEXT THURS.
ALSO NOTABLY...TEMPERATURES WILL DROP BACK TO BELOW NORMAL LEVELS.
HIGH TEMPERATURES WILL BE IN THE 60S AND 70S ON SUNDAY THROUGH
MUCH OF THE PERIOD.
&&
.AVIATION /05Z FRIDAY THROUGH TUESDAY/...
SFC COLD FRONT EXTENDED FROM NEAR KELM TO KIDI ATTM. THE FRONT
WILL MOVE SE AN CLEAR THE SERN TAF SITES /KMDT AND KLNS/ BETWEEN
05-06Z. MAINLY VFR CONDITIONS WERE SPREAD ACROSS THE CENTRAL
ZONES...WHILE SOME MVFR VSBYS WERE NOTED ACROSS THE LOWER SUSQ
VALLEY...AND MVFR CIGS OVER THE LAURELS.
AS THE COLDER AIR DEEPENS...CIGS AND VSBYS WILL DROP A BIT /TO
MAINLY IFR ACROSS THE WRN MTNS FOR SEVERAL HOURS WELL AFTER
MIDNIGHT/...LOW END MVFR VSBYS AND PERIODS OF MVFR CIGS DEVELOPING
ELSEWHERE. A COMPACT...BUT RATHER POTENT UPPER AIR DISTURBANCE
HEADING QUICKLY TO THE ESE ACROSS LAKE ERIE AND OHIO WILL SUPPORT
AN AREA OF SHOWERS AND A FEW TSRA...THAT SHOULD WEAKEN AS THEY
MOVE WELL INLAND FROM THE WARM LAKE ERIE WATERS. STILL EXPECT
SHOWERS LATE TONIGHT TO BE FOCUSED FOR A FEW HOURS ACROSS THE
LAUREL HIGHLANDS.
SHORT STATURE AND BRIEF DURATION/CLOSED CELLULAR BUT INTENSE
CONVECTION IS POSSIBLE ON FRI - MAINLY IN THE AFTN AS THE COLDEST
AIR ALOFT AND THE STRONGEST SHORT WAVE TROUGH CROSSES THE AREA.
THE MOST LIKELY TERMINALS WHICH MIGHT SEE SOME IMPACT WILL BE JST
AND BFD. WINDS WILL STAY UP A LITTLE TONIGHT AND PICK UP AND GUST
INTO THE 20-25KT RANGE DURING THE DAY AND MAYBE A LITTLE STRONGER
IN THE AFTN FRI.
OUTLOOK...
SAT...NO SIG WX EXPECTED.
SUN...PATCHY AM FOG POSSIBLE...OTHERWISE VFR.
SUN PM-MON AM...ISOLD SHRA POSS.
MON PM...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...CERU/GARTNER
AVIATION...DANGELO/RXR
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
944 AM MDT FRI SEP 13 2013
.UPDATE...
&&
.SHORT TERM...ONE BATCH OF LIGHT TO MODERATE RAIN IS MOVING
THROUGH CWA THIS MORNING AND THEN LOOKS LIKE ANOTHER WAVE FOR
LATER THIS AFTERNOON AND EVENING COMING IN FROM NEW MEXICO.
THE INITIAL RAINFALL THIS MORNING IS MORE LIGHT TO MODERATE RAIN
WITH RATES GENERALLY A THIRD OF AN INCH OR LESS IN ONE HOUR. LOOKS
LIKE A BREAK IN THE RAIN LATE THIS AM AND EARLY AFTERNOON UNTIL
THE NEXT BATCH OF RAIN MOVES IN. WITH THE BREAK...COULD BE SOME
BREAKS IN THE CLOUDS AND SOME HEATING WHICH COULD LEAD TO HEAVIER
RAIN AND ISOLATED THUNDERSTORMS. LATEST RAP AND HRRR DOES SHOW
SOME ECHO TRAINING OVER THE FOOTHILLS AND DENVER AREA. BASED ON
THIS HAVE DECIDED TO EXTEND THE FLASH FLOOD WATCH UNTIL 9 PM LOCAL
TIME THIS EVENING. OTHER THAN THAT NOT MANY CHANGES PLANNED.
.AVIATION...A BREAK IS COMING SO EXPECT CEILINGS/VSBYS LIFT A BIT
OVER THE NEXT FEW HOURS UNTIL LATER THIS AFTERNOON WHEN SHOWERS
REDEVELOPING IN IFR CIGS/VSBYS.
&&
.HYDROLOGY...FLASH FLOOD WATCH WILL BE EXTENDED THROUGH THIS
EVENING UNTIL 9 PM LOCAL TIME WITH MORE HEAVIER STORMS EXPECTED
LATER THIS AFTERNOON AND EVENING. ANY ADDITIONAL HEAVIER RAIN WILL
RESULT IN MORE FLASH FLOODING IN AREAS ALREADY SATURATED WITH RAIN.
THERE WILL BE A BREAK IN THE RAIN FROM MID MORNING UNTIL AT LEAST
EARLY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 258 AM MDT FRI SEP 13 2013/
SHORT TERM...A SHORTWAVE TROUGH WILL PUSH OVER THE STATE TODAY TO
DECREASE RAIN AFTER THE 3+ DAYS OF RECORD BREAKING RAINFALL ACROSS
THE FRONT RANGE. RAIN AMOUNTS ARE DECREASING ACROSS THE FOOTHILLS
AND METRO AREAS...BUT THE GROUND IS SO SATURATED THAT ANY
ADDITIONAL RAINFALL CAN AND WILL CONTINUE TO CAUSE PROBLEMS. SO
EVEN THOUGH THE FORECAST IS DECREASING RAIN...HAVE EXTENDED THE
FLASH FLOOD WATCH UNTIL NOON TODAY. RAIN IS INCREASING OVER THE
EASTERN PLAINS OF COLORADO...BUT THEY HAVE NOT RECEIVED AS MUCH
RAIN OVER THE LAST FEW DAYS AND THEREFORE WILL NOT INCLUDE THEM IN
THE WATCH. OVERALL...EXPECT ANOTHER QUARTER TO HALF AN INCH OF
WATER TODAY...WITH AREAS ALONG THE FOOTHILLS SEEING POTENTIALLY
ANOTHER INCH. TEMPERATURES WILL AGAIN NOT CHANGE MUCH THROUGH THE
DAY...BUT AS THE MOISTURE MOVES NORTH AND OUT OF THE AREA...SOME
MORE BREAKS IN THE CLOUDS ARE EXPECTED TO LET TEMPS WARM A FEW
DEGREES OVER YESTERDAYS HIGHS...BUT STILL BELOW AVERAGE FOR THIS
TIME OF YEAR.
THIS EVENING INTO THE NIGHT SHOULD SHOW DRAMATIC DECREASE IN
PRECIPITATION AND CLOUD COVER. THIS WILL ALLOW TEMPERATURES TO
COOL OVERNIGHT AND MAY ALLOW FOR AREAS OF FOG. NOT TOTALLY
CONFIDENT ON CLOUD COVER HOWEVER...SO WILL NOT INTRODUCE INTO THE
FORECAST JUST YET.
LONG TERM...MODELS HAVE THE UPPER TROUGH WEST OF COLORADO
SATURDAY THROUGH SUNDAY EVENING. THE FLOW ALOFT IS SOUTHWESTERLY
FOR THE CWA. THE WEAK UPWARD SYNOPTIC SCALE ENERGY IS PROGGED TO
CONTINUE ACCORDING TO THE QG VERTICAL VELOCITY FIELDS. THE
BOUNDARY LAYER WINDS ARE WEAK DOWNSLOPING SATURDAY. A COLD FRONT
AND UPSLOPE ARE PROGGED INTO THE PLAINS AND FOOTHILLS SATURDAY
EVENING. THE UPSLOPE IS PROGGED TO CONTINUE THROUGH SUNDAY
EVENING. FOR MOISTURE...SATURDAY DRIES OUT A BIT...BUT SUNDAY HAS
MORE MOISTURE. PRECIPITABLE WATER VALUES ARE PROGGED IN THE 0.80
TO 0.90 INCH RANGE OVER THE WESTERN PLAINS SATURDAY...THEN 0.90 TO
1.00 INCH SUNDAY. THE FURTHER EASTERN PLAINS ARE MORE MOIST
SATURDAY...BUT THE SAME ON SUNDAY. DEW POINT PROGGS HAVE MID 40S F
READINGS OVER THE WESTERN CWA TO LOWER 60S F OVER THE FAR EAST
THROUGH THE FOUR PERIODS. THE QPF FIELDS SHOW SATURDAY MORNING TO
BE DRY OVER THE CWA...THEN AMOUNTS INCREASE SATURDAY AFTERNOON.
THERE IS SOME OVER THE CWA SATURDAY NIGHT...THEN SUNDAY`S
MEASURABLE RAINFALL INCREASES OVER SATURDAY`S. THERE IS SOME
FAIRLY DECENT CAPE PROGGED OVER THE CWA LATE DAY SATURDAY...THEN
MUCH LESS SUNDAY...AND ITS JUST OVER THE MOUNTAINS. FOR POPS...
WILL KEEP THEM PRETTY HIGH ESPECIALLY FOR THE AFTERNOONS AND
EVENINGS. BETTER CONVECTION LATE DAY SATURDAY...MORE STABLE WITH
UPSLOPE FOR LATE DAY SUNDAY. FOR TEMPERATURES...SATURDAY`S HIGHS
ARE 3-6 C WARMER THAN FRIDAY`S. SUNDAY`S HIGHS COOL BACK OFF 4-8C
FROM SATURDAY`S. FOR THE LATER DAYS...MONDAY THROUGH THURSDAY
..MODELS HAVE FLAT UPPER RIDGING INTO WEDNESDAY. AN UPPER TROUGH
OVER THE NORTHERN U.S. BORDER WILL PUSH EASTWARD LATER WEDNESDAY
INTO THURSDAY JUST BRUSHING COLORADO. MOISTURE WILL BE PRETTY
SPARSE AND TEMPERATURES SHOULD BE RIGHT AROUND SEASONAL NORMALS.
AVIATION...CONTINUED LOW CEILINGS AND VISIBILITIES WITH RAIN AND
STRATUS WILL BE THE MAIN STORY THROUGH 12Z. IMPROVEMENTS ARE
THEN EXPECTED AS SLIGHTLY DRIER AIR MAKES ITS WAY INTO THE AREA
FROM THE SOUTH. SHOULD SEE RAIN END BY 00Z WITH CEILINGS LIFTING
TO VFR. CONTINUED EASTERLY TO SOUTHEASTERLY SURFACE WINDS...LESS
THAN 12 KNOTS. AREAS OF FOG A POSSIBILITY TONIGHT...BUT CONFIDENCE
IS LOW SO WILL NOT PUT IN THE TAFS FOR NOW.
HYDROLOGY...MULTIPLE FLOOD AND FLASH FLOOD WARNINGS IN EFFECT
WITH SIGNIFICANT IMPACTS. MAJOR RELIEF NOT EXPECTED UNTIL LATE
MORNING WITH SHOWERS EXPECT TO REMAIN UNTIL 00Z...BUT AT LESS
INTENSITY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH EXTENDED UNTIL 9 PM MDT TODAY FOR
COZ035-036-038>041- 043.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM....RJK
AVIATION...RTG
AREA FORECAST DISCUSSION
NWS MIAMI FL
1005 AM EDT FRI SEP 13 2013
.UPDATE...
LITTLE IN ONGOING FORECAST THIS MORNING. 12Z RAOB ANALYSIS SHOWS
IMPRESSIVE LOW-MID-LVL DRY AIR / SAL THAT IS IMPACTING AT LEAST
SOUTHERN CWA TODAY. AS A RESULT...PWAT IS ONLY 1.50. WITH THIS
AMOUNT OF DRY AIR AND POSSIBLY DUST INTERFERE...CONVECTIVE
INITIATION POTENTIAL IS HIGHLY UNCERTAIN...PARTICULARLY WITH LACK
OF OVERALL DYNAMICS. STILL...SEA BREEZE CIRCULATIONS COULD BE
SUFFICIENT FOR DEVELOPMENT OF TSTMS MAINLY OVER NORTHERN INTERIOR.
SYNOPTIC MODELS REFLECT THIS OCCURRING...BUT HRRR DEPICTS ON
MODEST DEVELOPMENT. POPS RMN IN SCATTERED RANGE
INTERIOR...ISOLATED ALONG THE COASTS/WATERS. DOWNBURSTS ARE
FAVORED IN ANY STRONG CONVECTION...SO GUSTY WINDS CANT BE RULED
OUT. SLOW STORM MOTION COULD ALSO LEAD TO SIGNIFICANT RAINFALL
TOTALS...ALTHOUGH STORM CHANCES ARE BEST OVER NON-URBAN/FLOOD
PRONE AREAS.
&&
.PREV DISCUSSION... /ISSUED 731 AM EDT FRI SEP 13 2013/
AVIATION...
TERMINAL KTMB COULD HAVE PERIODS OF IFR CONDITIONS DUE TO FOG
THROUGH THE 12Z-13Z TIME FRAME BUT SHOULD RAPIDLY DISSIPATE WITH
DAY TIME HEATING. OTHERWISE...MAINLY VFR CONDITIONS ARE EXPECTED
TO PREVAIL FOR THE REMAINING TERMINALS.
THERE IS SOME SAHARAN AIR LAYER DUST IN THE REGION COMING OFF THE
ATLANTIC WATERS. RECENT GUIDANCE SUGGESTS THE MOST CONCENTRATED PART
COULD REMAIN JUST SOUTH OF SOUTH FLORIDA ALTHOUGH SOME LESS
CONCENTRATED DUST AND DRIER AIR COULD IMPACT THE SOUTHERN HALF OR
THIRD OF THE PENINSULA TODAY. HARD TO SAY HOW MUCH IMPACT THIS MAY
HAVE ON AFTERNOON CONVECTION. GIVEN THE UNCERTAINTIES...THE CURRENT
TAF`S FOR ALL TERMINALS INDICATE VCTS IN THE 17Z-18Z TIME FRAME.
COULD BE A LITTLE SOONER FOR KPBI WITH A LINGERING BOUNDARY FROM
CONVECTION EARLIER THIS MORNING.
PREV DISCUSSION... /ISSUED 355 AM EDT FRI SEP 13 2013/
DISCUSSION...
THE MAIN SYNOPTIC FEATURES ACROSS THE REGION INCLUDE WEAK HIGH
PRESSURE ACROSS SOUTH FLORIDA AND ADJACENT WATERS...A CUT-OFF UPPER
LEVEL LOW OFF THE GEORGIA COASTLINE AND A PLUME OF DEEP LAYER
MOISTURE EXTENDING FROM NEAR LAKE OKEECHOBEE THEN NORTHEASTWARD INTO
THE ADJACENT ATLANTIC WATERS. THESE FEATURES RESULTED IN CONVECTION
ACROSS NORTHEASTERN PALM BEACH COUNTY AND THE ADJACENT ATLANTIC
WATERS DURING THE EARLY MORNING HOURS WITH LINGERING SHOWERS AND
THUNDERSTORMS JUST TO THE EAST OF PALM BEACH COUNTY.
THERE IS SOME SAHARAN AIR LAYER DUST IN THE REGION WITH
RECENT GUIDANCE SUGGESTING THE MOST CONCENTRATED PART WILL LIKELY
REMAIN JUST SOUTH OF SOUTH FLORIDA ALTHOUGH SOME LESS CONCENTRATED
DUST AND DRIER AIR COULD IMPACT THE SOUTHERN HALF OR THIRD OF THE
PENINSULA TODAY. HARD TO SAY HOW MUCH IMPACT THIS MAY HAVE ON
AFTERNOON CONVECTION...ALTHOUGH LATEST GUIDANCE SUGGESTS THAT
MAYBE ONLY ISOLATED ACTIVITY AT BEST MAY BE EXPECTED ACROSS THE
SOUTHERN PORTIONS OF THE PENINSULA AND ADJACENT WATERS . BUT GIVEN
THE UNCERTAINTIES...THE CURRENT FORECAST INDICATES ONLY ISOLATED
SHOWERS/THUNDERSTORMS IN THE SOUTHERN MOST ZONE IN THE PENINSULA
OTHERWISE ISOLATED TO SCATTERED ACTIVITY FOR THE REMAINING EAST
AND WEST COAST METRO AREAS WITH SCATTERED ACTIVITY FORECAST
INTERIOR REGIONS.
TONIGHT INTO SATURDAY A COLD FRONT THAT IS CURRENTLY JUST NORTH OF
THE CAROLINAS IS FORECAST TO MOVE INTO NORTH FLORIDA ON SATURDAY
AND BECOME DIFFUSE THE REMAINDER OF THE WEEKEND. THE
AFOREMENTIONED CUT-OFF UPPER LEVEL LOW IS FORECAST TO QUICKLY LIFT
OFF TO THE NORTHEAST TODAY AND TONIGHT AND GET MERGED INTO A LARGE
AMPLITUDE UPPER LEVEL TROUGH FORECAST TO DIG INTO THE EASTERN SEA-
BOARD ON SATURDAY. FOR SATURDAY...WITH LINGERING MOISTURE ACROSS
THE REGION AND EASTERLY FLOW RETURNING MAINLY AFTERNOON ISOLATED
TO SCATTERED SHOWERS/THUNDERSTORMS ARE FORECAST WITH ISOLATED
ACTIVITY EXPECTED ACROSS THE EASTERN THIRD OF THE PENINSULA AND
SCATTERED ACROSS THE REMAINDER OF THE PENINSULA. BY SUNDAY THE
LARGE AMPLITUDE UPPER LEVEL TROUGH DIGS INTO THE SOUTHEAST U.S.
AND INTO THE REGION. THAT COUPLED WITH AN ADDITIONAL INFLUX OF
MOISTURE FROM THE ATLANTIC WATERS IS FORECAST TO RESULT IN
AFTERNOON SCATTERED SHOWERS AND THUNDERSTORMS. SIMILAR SYNOPTIC
CONDITIONS WILL PERSIST THROUGH THE EARLY PART OF THE WEEK. IN THE
LATER HALF OF THE WEEK ALTHOUGH MID TO UPPER LEVEL RIDGING BUILDS
INTO THE REGION...DEEP LAYERED MOISTURE IS FORECAST TO PREVAIL
ACROSS THE AREA WITH DIURNALLY DRIVEN SHOWERS/THUNDERSTORMS
FORECAST WEDNESDAY THROUGH FRIDAY.
MARINE...
WINDS ACROSS THE REGIONAL WATERS TODAY WILL BE LIGHT AND COULD AT
TIMES BECOME LIGHT AND VARIABLE. BY SATURDAY EASTERLY FLOW WILL
RETURN IN THE 6 TO 10 KNOT RANGE AND THEN BY MONDAY THROUGH MID-
WEEK MODERATE EASTERLY FLOW IN THE 10 TO 15 KNOT RANGE IS
FORECAST. TODAY THROUGH THE WEEKEND SEAS ACROSS THE GULF AND
ATLANTIC WATERS ARE EXPECTED TO BE 2 FEET OR LESS AND MONDAY
THROUGH NEXT WEEK SEAS FROM 2 TO 3 FEET ARE POSSIBLE ACROSS THE
ATLANTIC WATERS AND THE OFF SHORE GULF WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 75 89 78 / 20 20 20 30
FORT LAUDERDALE 89 79 90 80 / 20 10 20 30
MIAMI 90 77 90 79 / 20 10 20 20
NAPLES 90 75 93 76 / 20 10 20 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...23/SK
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1040 AM CDT FRI SEP 13 2013
.UPDATE...A BAND OF VERY ISOLATED PRE-FRONTAL SHOWERS OVER THE
NORTHERN HALF OF THE CWA DISSIPATED BEFORE REACHING JACKSON AND
MERIDIAN EARLIER THIS MORNING. THE COLD FRONT IS NOW KNOCKING ON THE
NORTHERN BORDER OF CWA WITH DEWPOINTS ALREADY FALLING INTO THE LOWER
60S AT TUPELO...OXFORD AND CLARKSDALE. WINDS HAVE SHIFTED TO N/NELY
ACROSS MUCH OF THE AREA AS THE PRESSURE TROUGH HAS ALREADY PUSHED
SOUTH TO THE I-20 CORRIDOR. AS INSTABILITY INCREASES THROUGH THE
DAY...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL REDEVELOP
SOUTH OF THE FRONT. THE LATEST HRRR SHOWS THIS REDEVELOPMENT
OCCURRING IN THE 18Z/19Z TIME FRAME MAINLY SOUTH OF A LINE FROM THE
AR/LA BORDER TO CARTHAGE TO DE KALB AND PUSHING SOUTH THROUGH THE
AFTERNOON AS THE FRONT CONTINUES TO MAKE PROGRESS ACROSS THE AREA.
ACTIVITY WILL THEN DECREASE AROUND 00Z/01Z DUE TO BOTH THE MOVEMENT
OF THE FRONT AND THE DECREASE OF INSTABILITY. THE CURRENT FORECAST
HAS A PRETTY GOOD HANDLE ON THE SITUATION. SOME MINOR ADJUSTMENTS
WILL BE MADE TO TEMP/DEWPOINT/ WIND/SKY GRIDS TO ADJUST TO THE
LATEST TRENDS AND FRONTAL TIMING. WILL ALSO BACK OFF ON POPS ALONG
THE 82 CORRIDOR AS IT BECOMES LESS AND LESS LIKELY THAT
REDEVELOPMENT OCCURS BEFORE THE FRONT MOVES THROUGH THAT AREA. /DL/
&&
.AVIATION...MAINLY VFR CONDS EXPECTED TO PREVAIL THROUGH THE DAY BUT
ISO/SCT SHRA EXPECTED TO DEVELOP ACROSS MAINLY SITES ALONG AND SOUTH
OF THE I-20 CORRIDOR EARLY AFTERNOON THROUGH EARLY EVENING AS A COLD
FRONT MOVES THROUGH THE REGION. WINDS WILL BE LIGHT AND NORTHERLY
AHEAD OF THE COLD FRONT AND THEN PICK UP TO 10-12KT FROM THE SAME
DIRECTION AS THE FRONT PASSES THIS AFTN FROM NORTH TO SOUTH. WINDS
WILL STAY UP AROUND 5 KTS THROUGH THE OVRNGT SAT MRNG. ANY CLOUD
CEILINGS SHOULD BE GREATER THAN 4 KFT ASIDE FROM A FEW HEAVIER
SHOWERS WHERE VERY BRIEF MVFR FLIGHT CATS COULD BE ENCOUNTERED
ACROSS JAN/HKS/NMM/MEI/PIB/HBG. /BB/
&&
.DISCUSSION... /ISSUED AT 1015 AM CDT FRI SEP 13 2013/
TODAY THROUGH SUNDAY MORNING
A WEAK COOL FRONT PASSAGE TODAY WILL AID IN ISOLATED TO SCATTERED
SHOWER DEVELOPMENT THIS MORNING THROUGH TONIGHT. A MUCH DRIER,
COOLER, AND QUITE COMFORTABLE AIRMASS WILL SETTLE IN FOR THE
WEEKEND.
THE AFOREMENTIONED COOL FRONT IS ANALYZED ALONG A NASHVILLE, TN TO
DYER, TN TO NORTH OF A LITTLE ROCK, AR LINE AT 08Z THIS MORNING.
THIS FRONT IS BEING DRIVEN BY A DEEPENING L/WV TROUGH ACROSS THE
EASTERN SEABOARD AND A STRENGTHENING SFC HIGH ACROSS THE UPPER
MIDWEST. AHEAD OF THIS FRONT HOWEVER, IS A PREFRONTAL TROUGH AND
ASSOCIATED H5 PVA RIBBON PER RAP ANALYSIS. THE TRAILING PREFRONTAL
TROUGH AXIS EXTENSION FROM THE NE CONUS HAS ALLOWED TO KICK OFF A
FEW SHOWERS EARLY THIS MORNING ACROSS FAR N/NE MS. THIS VERY
ISOLATED AND TRANSIENT ACTIVITY WILL FESTER THROUGH THE MORNING AND
WILL MOVE SOUTH IN CONJUNCTION WITH THE H5 PVA RIBBON. BY MID TO
LATE MRNG, THE FRONT SHOULD BE ON HWY-82 CORRIDOR DOORSTEP NORTH OF
THIS H5 RIBBON, AND THUS WILL MAINLY RELY ON INSTABILITY FACTORS FOR
PARCEL BUOYANCY VS. ANY DYNAMIC LIFT MECHANISM. ISOLATED SHOWERS
SHOULD GET GOING BETWEEN HWY-82 AND I-20 LATE MRNG/EARLY AFTN WITH
BETTER COVERAGE EXPECTED NEAR AND SOUTH OF I-20 BY MID AFTN AS SFC
BASED INSTABILITY BUILDS UPWARDS TO 1200 J/KG. SOME THUNDERSTORMS
MAY DEVELOP BUT WITH MEAGER INSTABILITY, WEAK LOW-LVL CONVERGENCE
AND POOR LAPSE RATES, NOT EXPECTING ANY STRONG THUNDERSTORMS NOR
MODEST LIGHTNING PRODUCERS. WENT WELL ABOVE MAV POPS AGAIN TOWARDS
MET NUMBERS IN THE 20-30% RANGE ACROSS THE REGION TODAY BUT BROKE UP
DAY TO INDICATE SHOWER PROBS DECREASING NORTH TO SOUTH THROUGH TIME.
SKIES WILL CLEAR THROUGH THE OVERNIGHT WITH THE FRONT PUSHING
THROUGH THE REGION TO THE SOUTH SATURDAY MRNG. SFC DEWPOINTS IN THE
LOW 50S NORTH TO NEAR 60 SOUTH WILL DROP HUMIDITY LEVELS AND MAKE IT
FEEL QUITE COMFORTABLE TO BE OUTSIDE THROUGH THE DAY. HIGHS SATURDAY
WILL TOP OUT IN THE LOW 80S NORTH TO UPPER 80S SOUTH, SOME 10-13F
DEGREES COOLER FROM THIS PAST WEEK. LOWS SATURDAY AND SUNDAY WILL
RANGE FROM THE MID 50S NORTH TO THE MID 60S SOUTH. /ALLEN/
SUNDAY THROUGH NEXT FRIDAY
NUMERICAL MODELS CONTINUE TO BE IN SOLID AGREEMENT ON
THE MED RANGE/LONG TERM. THE GENERAL PATTERN WILL CONTINUE TO BE ONE
OF RIDGING ALOFT...ALBEIT WEAKER THAN WHAT WE HAVE BEEN SEEING...AND
STEADY MOISTENING AS WE GO THROUGH THE WORK WEEK.
THE COOL FRONT WILL WASH OUT ON SUNDAY AND ALLOW FOR A DECENT WARM
UP ALONG WITH ALLOWING BETTER LOW LEVEL MOISTURE TO RETURN ACROSS
THE S HALF OF THE CWA. WHILE NOT MUCH SHOWER ACTIVITY IS
EXPECTED...CAN`T RULE OUT AN ISOLATED SHOWER ACROSS THE HWY 84
CORRIDOR BY AFTERNOON. THE PATTERN WILL STEADILY TRANSITION THROUGH
MIDWEEK AND BECOME ONE WITH A MORE DEEP SE FLOW. THIS WILL RESULT IN
ALLOWING MORE DEEP TROPICAL MOISTURE INTO THE REGION ALONG WITH SOME
WEAKENING OF THE SUBTROPICAL RIDGE. THE RESULT WILL BE BETTER PRECIP
CHANCES FOR MID/LATE WEEK. THIS MAY BE THE BEGINNING OF A WETTER
PATTERN TO END THE MONTH. WE WILL SEE IF THE MODELS CONTINUE TO SHOW
THIS OVER THE NEXT FEW RUNS.
AS FOR TEMPS...GFS GUIDANCE SEEMS TO HAVE A SOLID HANDLE ON EXPECTED
CONDITIONS. MODERATION WILL BE THE WORD FOR SUN-MON AS THE AREA
WARMS BACK INTO THE 90-95 DEGREE RANGE AGAIN. BY MID WEEK...DEEPER
MOISTURE...MORE CLOUDS AND INCREASED RAIN POTENTIAL WILL TAPER TEMPS
BACK TOWARD NORMAL. /CME/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DL/BB/ALLEN/CME
AREA FORECAST DISCUSSION
NWS BILLINGS MT
833 AM MDT FRI SEP 13 2013
.UPDATE...
OVERALL FORECAST APPEARS TO BE IN GOOD SHAPE SO HAVE MADE ONLY
FEW CHANGES THIS MORNING. AREA OF SHOWERS IN CENTRAL WY ASSOCIATED
WITH SHORTWAVE LIFTING OUT OF THE CENTRAL ROCKIES IS CURRENTLY
SPREADING INTO THE SOUTHERN BIG HORNS. RAP SEEMS TO HAVE A FAIR
HANDLING OF THIS...WITH BACKING MID LEVEL FLOW EXPECTED TO
TRANSLATE NORTHWARD OVER THE NEXT SEVERAL HOURS. MOISTURE
ADVECTION IN ADDITION TO DEEPENING UPSLOPE FLOW SHOULD YIELD AN
ENHANCED CHANCE OF SHOWERS ALONG THE EAST SIDE OF THE BIG HORNS
INCLUDING SHERIDAN BY LATE AFTERNOON AND CONTINUING INTO THE
EVENING. HAVE RAISED POPS AND QPF AMOUNTS IN THIS AREA.
OTHERWISE...COOLING UPPER LEVEL TEMPS IN RESPONSE TO NORTHWARD
MOVING UPPER LOW ALONG WITH DIURNAL HEATING AND WEAK Q-VECTOR
CONVERGENCE SHOULD RESULT IN SCATTERED SHOWERS AND SOME
THUNDERSTORMS THIS AFTERNOON AND EVENING. NO SEVERE WEATHER
EXPECTED BUT ANY STRONGER CELLS WILL CERTAINLY PRODUCE LOCALLY
HEAVY RAIN AS PWATS GET PUSHED UP TO AROUND AN INCH...CONSISTENT
WITH UPSTREAM 12Z RAOBS. JKL
&&
.SHORT TERM...VALID FOR TDY AND SAT...
SCATTERED SHOWERS AND STORMS WITH LOCALLY HEAVY RAIN ARE EXPECTED
TODAY THROUGH SATURDAY AS A WEAKENING UPPER-LEVEL LOW WORKS NORTH
INTO THE REGION.
TODAY...A MID-LEVEL VORTICITY MAXIMUM OBSERVED ACROSS THE CENTRAL
ROCKIES EARLY THIS MORNING WILL MOVE NORTH AND REACH THE SOUTHERN
PARTS OF MT BY LATE AFTERNOON. THIS SHOULD FOSTER SOME CONVECTION
AS DEEP-LAYER MOISTURE INCREASES ON SOUTHERLY FLOW...BRINGING THE
AIR MASS WITH NEARLY ONE INCH OF PRECIPITABLE WATER CAPTURED WITH
THE 00 UTC RIVERTON SOUNDING INTO THE AREA. ISOLATED TO SCATTERED
SHOWERS SHOULD DEVELOP BY LATE AFTERNOON...WITH EARLIER FORMATION
AND GREATER COVERAGE WORTHY OF LIKELY POPS IN THE BIG HORNS BASED
ON RECENT HIGH-RESOLUTION MODEL SIMULATIONS. SCATTERED STORMS ARE
IN THE FORECAST FROM THE BEARTOOTH/ABSAROKA MOUNTAINS EASTWARD TO
SHERIDAN AS FORECAST SOUNDINGS SHOW 500 J/KG OF MUCAPE OVER THOSE
AREAS AFTER 18 UTC. THE CALIBRATED THUNDERSTORM PROBABILITIES OFF
OF THE 03 UTC SREF ALSO SUPPORT THAT IDEA. FURTHER NORTH...SLIGHT
CHANCES OF THUNDER WITH THE SHOWERS SHOULD SUFFICE IN PLACES LIKE
BILLINGS AND MILES CITY...WHERE MID-LEVEL LAPSE RATES ARE WEAKER.
TONIGHT...A MODERATE BATCH OF 500-300 HPA Q-VECTOR CONVERGENCE IS
EXPECTED TO BE OVER THE AREA...SO SOME POPS ARE IN PLAY ALL NIGHT
EVEN THOUGH CONVECTION SHOULD DIMINISH A BIT DIURNALLY. LOWS WILL
PROBABLY NOT FALL BELOW 60 F IN SOME LOWER ELEVATIONS WITH CLOUDS
INHIBITING SURFACE COOLING.
SAT...WEAK FORCING WILL REMAIN IN PLACE ALOFT...AND THE MID-LEVEL
LAPSE RATES ACTUALLY STEEPEN A BIT. IN ADDITION...A COLD FRONT IS
EXPECTED TO DROP SOUTH INTO THE AREA FROM THE NORTH...WHICH COULD
ENHANCE LOW-LEVEL VERTICAL MOTION IN SUPPORT OF CONVECTION. WINDS
WILL EVEN TURN TO AN UPSLOPE DIRECTION BEHIND THE FRONT. WE COULD
ULTIMATELY NEED LIKELY POPS FOR MORE OF THE LOWER ELEVATIONS ONCE
RUN-TO-RUN WOBBLES IN THE POSITION OF FORCING TIED TO A WEAKENING
WAVE SETTLE DOWN. FINALLY...NOTE THAT TEMPERATURES WILL BE HIGHLY
DEPENDENT ON CLOUDS AND PRECIPITATION TOO...WHICH MEANS HIGHS MAY
END UP MUCH COOLER THAN ADVERTISED IN SOME AREAS. SCHULTZ
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
MODELS GENERALLY IN GOOD AGREEMENT OVER BASIC PATTERNS AFFECTING
THE LONG TERM FORECAST. THERE ARE SOME TIMING DIFFERENCES WHICH
OCCUR WITH A SHORT WAVE EXCITING NORTHERN ROCKIES AT THE MIDDLE
PART OF NEXT WEEK...BUT THESE ARE RELATIVELY MINOR AND DO NOT
AFFECT THE OVERALL OUTCOME OF FORECAST HIGHS...LOWS AND POPS. MAIN
CHANGES FOR THIS FORECAST PACKAGE WERE TO LOWER OR REMOVE POPS
AFTER MIDWEEK.
BEGINNING SUNDAY...WE WILL BE UNDER LOW LEVEL EASTERLY FLOW BEHIND
SATURDAY NIGHTS COLD FRONT. SO STABLE CONDITIONS AND SEASONAL
TEMPERATURES SHOULD PREVAIL. WE EXPECT TO QUICKLY WARM UP MONDAY
BACK INTO THE 80S FOR MANY AREAS AS A LARGE RIDGE ALOFT CONTROLS
THE WEATHER. A FAST MOVING WEATHER SYSTEM WILL QUICKLY SWEEP INTO
THE NORTHERN ROCKIES TUESDAY ON THE NOSE OF A 90KT MID LEVEL JET.
THIS APPEARS SOMEWHAT FALL LIKE TO ME...BUT IS ROBUST ENOUGH TO
PRODUCE THUNDERSTORMS ALONG WITH SHOWERS AND WINDY CONDITIONS.
BEHIND THIS SYSTEM...LOOK FOR A RETURN TO SEASONAL TEMPERATURES
AND MAINLY DRY CONDITIONS AS FLOW ALOFT BECOMES MORE ZONAL IN
NATURE...A DEFINITE SIGN OF AUTUMN ON ITS WAY. BT
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL INTO THE AFTERNOON HOURS. SCATTERED
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER THE HIGHER
TERRAIN BY EARLY AFTERNOON...AND SPREAD TO THE LOWER ELEVATIONS
BY EVENING. A FEW STORMS MAY PRODUCE LOCAL LIFR CONDITIONS THIS EVENING
AND OVERNIGHT...DUE TO REDUCED VIS IN HEAVY RAIN. OCCASIONAL
MOUNTAINS TOP OBSCURATION IS EXPECTED BY THIS EVENING AS WELL. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 083 061/075 055/077 055/085 057/081 054/073 049/073
3/T 35/T 51/B 11/U 23/T 32/W 11/U
LVM 084 054/072 048/078 050/085 049/078 045/072 042/072
3/T 45/T 52/T 12/T 23/T 32/W 21/B
HDN 084 057/076 051/079 052/086 054/083 052/076 048/076
3/T 45/T 51/B 11/U 13/T 32/W 11/U
MLS 084 061/077 052/076 053/084 058/083 056/074 050/074
2/T 35/T 31/U 01/U 12/T 33/W 11/B
4BQ 081 056/076 049/076 050/083 053/084 053/076 047/075
3/T 55/T 52/T 11/U 11/U 22/W 11/U
BHK 082 057/075 048/072 048/078 053/082 054/074 047/072
1/N 35/T 31/U 01/U 11/U 33/W 21/U
SHR 078 055/073 048/074 048/082 051/082 050/075 044/073
6/T 65/T 52/T 11/U 11/U 33/W 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
621 AM CDT FRI SEP 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT FRI SEP 13 2013
TODAY AND TONIGHT...THE MODELS APPEAR TO BE TOO FAST AND AGGRESSIVE
LIFTING THE AREA OF RAIN ACROSS NWRN KS/NERN COLO THROUGH THE FCST
AREA TODAY AND TONIGHT. SO THE FORECAST SLOWS THIS BY 3 HOURS WHICH
MAY NOT BE ENOUGH. OTHERWISE...THE CLOUD SHIELD ACROSS SWRN NEB
SHOULD SPREAD SLOWLY NORTH TODAY AND TONIGHT. THE FORECAST ATTEMPTS
TO MARK UP TEMPS FOR WARMER HIGHS AS THE CLOUDS AND RAIN WILL LIKELY
BE DELAYED BY SEVERAL HOURS AND MAY NOT REACH INTERSTATE 80 UNTIL
LATE THIS AFTERNOON.
MODEL BLENDED QPF PRODUCED AROUND 1/3 OF AN INCH ACROSS SWRN NEB TO
0.05 INCHES ACROSS ERN ZONES. THE RAP MODEL LIFTS THE RAIN NORTH
VERY QUICKLY AND DRIES IT OUT AT THE SAME TIME WHICH IS LIKELY A
RESULT OF DRY AIR AT THE LOWER LEVELS. THE HRRR MODEL IS WAY TOO
FAST AND A PLUME OF ALL MODEL SOLNS FOR NORTH PLATTE SHOW A VERY
WIDE SPREAD OF QPF TOTALS FROM 1/3 OF AN INCH TO A TRACE. THUS THE
RAIN CHANCES ACROSS MUCH THE FCST AREA EXCEPTING FAR SWRN NEB ARE
UNCERTAIN.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 340 AM CDT FRI SEP 13 2013
FORECAST CONFIDENCE REMAINS AVERAGE THROUGH THE WEEKEND WITH
DECENT CONSISTENCY DISPLAYED FROM THE LONG RANGE SOLUTIONS. FOR
SATURDAY...RAIN CHANCES DO NOT APPEAR TO BE AS WIDESPREAD AS THE
BULK OF THE QG FORCING AND ASSOCIATED WEAKENING UPPER LEVEL LOW IS
DIRECTED TO THE NORTH AND WEST OF THE CWA...BUT INCREASING
ATMOSPHERIC INSTABILITY WITH SUFFICIENT MOISTURE WOULD ALLOW FOR
AT LEAST A CONTINUED MENTION OF STORMS THROUGH THE DAY. BETTER
CHANCES HOWEVER APPEAR TO ARRIVE LATE SATURDAY INTO EARLY SUNDAY
AS A WEAK DISTURBANCE WORKS ON A PASSING FRONTAL BOUNDARY...SHOWER
AND THUNDERSTORM CHANCES WILL REMAIN HIGHEST ALONG OUR SOUTHERN
AND EASTERN BORDERS AS THE FRONT SETTLES ACROSS KANSAS. WITH HIGH
PRESSURE BUILDING SOUTH ACROSS THE NORTHERN HIGH PLAINS AND INTO
THE UPPER MISSISSIPPI RIVER VALLEY ON SUNDAY...DRIER CONDITIONS
ARE ANTICIPATED FOR MUCH OF THE REGION. THERE WILL BE A SHARP
DIVIDING LINE HOWEVER AS A CONTINUED TAP OF MOIST MONSOONAL AIR
DRIVES NORTH THROUGH THE SOUTHERN PLAINS. A RECENT TREND OF THE
LONGER RANGE SOLUTIONS IS TO SETTLE THE FRONT FURTHER SOUTH ACROSS
SOUTHERN/CENTRAL KANSAS WITH DRIER AIR /VOID OF PRECIPITATION/
ACROSS MOST IF NOT ALL LOCATIONS ACROSS THE CWA. DID NOT WANT TO
ENTIRELY PULL POPS YET ON SUNDAY AND INTO MONDAY...THUS WILL LOWER
TO A SLIGHT CHANCE MENTION FOR MOST PLACES...BUT FEEL WE COULD GO
LOWER YET. WITH THE DRIER AIR WORKING SOUTH...CONDITIONS WILL BE
PLEASANTLY COOL ON SUNDAY...WITH HIGHS TOPPING OUT IN THE UPPER
60S TO LOW 70S. LOOKING AHEAD TO EARLY NEXT WEEK...THE MODEL
CONSENSUS DEVELOPS A BROAD RIDGE ACROSS THE CENTRAL CONUS WITH
PERIODIC SHORTWAVES SUPPRESSING ITS STRENGTH. A GENERAL WARMING
TREND IS THEN SHOWN...WITH HIGHS RETURNING BACK INTO THE 80S AS
EARLY AS TUESDAY...AND LOWS FALLING INTO THE UPPER 50S FOR MOST
PLACES. PERIODIC STORM CHANCES ARE IN STORE FOR NEXT WEEK...MAINLY
ACROSS EASTERN PORTIONS OF THE CWA AS A FRONT STALLS AND PERIODIC
WAVES PASS THROUGH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 613 AM CDT FRI SEP 13 2013
THE AREA OF RAIN ACROSS NERN COLO/WRN KS IS EXPECTED TO LIFT NORTH
THROUGH THE FCST AREA TODAY AND TONIGHT PRODUCING AREAS OF
MVFR/IFR. THIS AREA OF RAIN IS EXPECTED TO HAVE THE LEAST IMPACT
ACROSS NERN NEB WHERE HIGH PRESSURE AND DRY AIR AT THE LOWER
LEVELS MAY EVAPORATE THE RAIN BEFORE REACHING THE GROUND.
UPSLOPE WINDS TODAY AND TONIGHT MAY KEEP CIGS MVFR OR LOWER EVEN
AFTER THE RAIN ENDS ACROSS WRN NEB...HIGHWAY 61 AND WEST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS ELKO NV
325 AM PDT FRI SEP 13 2013
.SYNOPSIS...ABUNDANT MOISTURE AND INSTABILITY FROM A SLOW MOVING
STORM SYSTEM WILL BRING SCATTERED THUNDERSTORMS AND WIDESPREAD
SHOWERS TO NORTHERN NEVADA. SOME AREAS MAY SEE HEAVY RAIN...WITH
POSSIBLE FLOODING CONCERNS. LOOK FOR SCATTERED THUNDERSTORMS
AGAIN ACROSS EASTERN NEVADA ON SATURDAY. DRY WEATHER RETURNS TO
NEVADA SUNDAY THROUGH NEXT WEEK...WITH BREEZY CONDITIONS MONDAY
INTO TUESDAY.
&&
.SHORT TERM...TODAY THROUGH SATURDAY. A LARGE COUNTERCLOCKWISE
CIRCULATION CAN BE SEEN OVER NORTHEAST NEVADA THIS MORNING. THIS
IS ASSOCIATED WITH AN UPPER LEVEL STORM SYSTEM THAT HAS BEEN SLOW
TO MOVE OUT OF THE AREA. IT HAS BEEN RESPONSIBLE FOR THE RAINFALL
THE AREA HAS RECEIVED IN THE LAST TWO DAYS. MODELS SHOW IT MOVING
SLOWLY EAST DURING THE DAY TODAY. BUT WE WILL STILL BE UNDER ITS
EFFECTS.
RIGHT NOW...RADAR IS SHOWING SOME WEAK RETURNS WITH LIGHT SHOWERS
OVER PORTIONS OF HUMBOLDT COUNTY...WITH ENHANCED ACTIVITY SEEN IN
SOUTHWEST IDAHO. 3KM HRRR IS SHOWING AN INCREASE IN SHOWER ACTIVITY
BEGINNING IN THE LATE MORNING HOURS OVER ELKO AND WHITE PINE
COUNTIES.
MODELS CONTINUE TO SHOW A FAVORABLE ENVIRONMENT FOR SHOWERS AND
THUNDERSTORMS TO DEVELOP TODAY. CAPE VALUES ARE FORECAST TO BE
AROUND 200-600 J/KG...WITH THE HIGHEST VALUES SEEN IN WHITE PINE
AND ELKO COUNTIES. STORM MOTIONS WILL ONCE AGAIN BE QUITE SLOW AT
ABOUT 5 TO 10 KNOTS IN THE 700-500 MB LAYER. K-VALUES DURING THE
FRIDAY TIME FRAME RANGE FROM 35-40C...WITH CORFIDI VECTOR
MAGNITUDES OF 0-5 KNOTS. BASED ON THE GUIDANCE...WILL CONTINUE THE
FLASH FLOOD WATCH WITH NO CHANGES. POP GRIDS ALSO LOOKED GOOD AND
ONLY MADE MINOR ADJUSTMENTS.
FOR TONIGHT...UPPER LEVEL SYSTEM WILL SLOWLY WORK ITS WAY EAST AND
SET UP SHOP SOMEWHERE AROUND NORTHERN UTAH. THE REGION WILL STILL
BE UNDER A MOIST AND UNSTABLE ATMOSPHERE SO HAVE CONTINUED
ISOLATED THUNDERSTORMS WITH SCATTERED TO NUMEROUS RAIN SHOWERS.
BY SATURDAY...THE FORECAST AREA WILL BE UNDER A NORTHWEST FLOW
ALOFT...WITH SOME MINOR DRYING TAKING PLACE IN THE WESTERN ZONES.
BUT IT SHOULD BE MOIST AND UNSTABLE ENOUGH IN THE
EAST...ELKO...EUREKA...WHITE PINE...AND NORTHEAST NYE
COUNTIES...FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS.
AFTERNOON HIGHS WILL RUN AT OR JUST ABOVE NORMAL.
.LONG TERM...SATURDAY NIGHT THROUGH NEXT THURSDAY. MODELS IN GOOD
AGREEMENT ONLY EXCEPTION IS THE GFS IS A BIT COOLER AND STRONGER
WITH THE TROUGH MOVING ACROSS NORTHERN NEVADA ON TUESDAY AND
WEDNESDAY. ISOLATED THUNDERSTORMS EXPECTED ACROSS NORTHEASTERN
NEVADA ON SUNDAY AFTERNOON AND EVENING AS A UPPER LEVEL TROUGH ALONG
WITH INSTABILITY AND RESIDUAL MOISTURE REMAIN OVER THIS AREA. MUCH
DRIER CONDITIONS THROUGH THE REST OF THE PERIOD...ONLY SIGNIFICANT
WEATHER WILL BE COOLING TEMPERATURES AND BREEZY WINDS EARLY NEXT WEEK AS
A COLD FRONT MOVES THROUGH THE AREA LATE MONDAY INTO TUESDAY MORNING
AND THEN ANOTHER WARM UP BY THURSDAY AHEAD OF A STRONG UPPER LEVEL
SYSTEM. TEMPERATURES WILL BE ABOVE NORMAL SUNDAY THROUGH TUESDAY
BEFORE COOLING TO NEAR NORMAL READINGS BY THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...MAINLY VFR CONDITIONS HOWEVER KELY MAY SEE SOME
INTERMITTENT MVFR CIGS AND OTHER TERMINALS MAY TEMPORARILY SEE MVFR
VISIBILITIES DUE TO HEAVIER RAIN SHOWERS. THUNDERSTORMS POSSIBLE AT
ALL TERMINALS WITH 20 PERCENT CHANCE AT KTPH AND KWMC AND 30 TO 40
PERCENT CHANCE AT KELY AND KEKO.
&&
.FIRE WEATHER...VERY MOIST AIR MASS OVER THE AREA...COMBINED WITH
INSTABILITY...WILL PROVIDE THE IMPETUS FOR SHOWERS AND
THUNDERSTORMS ACROSS MUCH OF NORTHERN NEVADA. SOME DRYING POSSIBLE
TOMORROW IN THE WESTERN ZONES...BUT SHOULD SEE SCATTERED SHOWERS
AND THUNDERSTORMS IN THE EASTERN FIRE ZONES OF 454 AND 457...AND
WELL AS ALL OF ZONE 455 AND 469 AND 470. EVEN DRIER STILL ON
SUNDAY WITH ONLY ISOLATED COVERAGE IN 469 AND 470. A DRY COLD
FRONTAL PASSAGE EXPECTED MONDAY INTO TUESDAY WHICH WILL BRING
BREEZY CONDITIONS TO NORTHERN NEVADA.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR NORTHEASTERN NYE
COUNTY...NORTHERN ELKO COUNTY...NORTHERN LANDER COUNTY AND
NORTHERN EUREKA COUNTY...RUBY MOUNTAINS/EAST HUMBOLDT RANGE...
SOUTH CENTRAL ELKO COUNTY...SOUTHEASTERN ELKO COUNTY...SOUTHERN
LANDER COUNTY AND SOUTHERN EUREKA COUNTY...SOUTHWESTERN ELKO
COUNTY...WHITE PINE COUNTY.
&&
$$
86/90/90/86
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1032 AM EDT FRI SEP 13 2013
.SYNOPSIS...
MUCH COOLER AIR FOLLOWING THE PASSAGE OF A COLD FRONT WILL DROP
TEMPERATURES WELL BELOW SEASONAL AVERAGES FOR THE NEXT COUPLE OF
DAYS. THE COLDER AIR WILL PRODUCE LAKE EFFECT CLOUDS ACROSS MUCH OF
THE REGION...WITH SCATTERED LAKE EFFECT SHOWERS TODAY INTO PART OF
TONIGHT. HIGH PRESSURE BUILDING ACROSS NEW YORK STATE WILL THEN
BRING MOSTLY SUNNY SKIES THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
A LONGWAVE TROUGH IS CENTERED OVER QUEBEC/NY THIS MORNING WITH AN
EMBEDDED SHORTWAVE TROUGH OVER CENTRAL NY. RUC ANALYSIS SHOWS THE
COLD AIR AT 500MB WITH THIS FEATURE NEARLY OVERHEAD. WIDESPREAD
CLOUD COVER WILL CONTINUE UNDER THIS REGIME WITH GENERALLY NORTHERLY
FLOW ALOFT. AS FAR A RAIN SHOWERS GO...WARMING ALOFT AT 500MB WILL
NEGATE LOWER LEVEL INSTABILITY OVER FAR WESTERN NY. THERE IS ALSO
SOME DIRECTIONAL SHEAR IN THE LOW LEVEL AIRMASS. SO WHILE SOME
SHOWERS ARE POSSIBLE...DO NOT EXPECT ANYTHING LONG LIVED SHOWER
ACTIVITY...WITH TRACE TO A FEW HUNDREDTHS OVER THE COURSE OF THE
DAY.
TOWARD THE EASTERN LAKE ONTARIO...A DIFFERENT SCENARIO MAY RESULT AS
THE SHORTWAVE TROUGH SLOWLY MOVES NE WITH COOLING ALOFT AT ALL
LEVELS. RADAR RETURNS ARE MOSTLY QUIET NOW WITH WEBCAMS SHOWING
MOSTLY LIGHT SPRINKLES. WITH AFTERNOON MIXING...EXPECT SOME
CELLULAR SHOWER ACTIVITY TO DEVELOP.
IN TERMS OF TEMPERATURES...CLOUD COVER AND ONGOING COLD AIR
ADVECTION WILL KEEP TEMPERATURES IN THE 50S TODAY...WHICH IS ALMOST
20 DEGREES BELOW AVERAGE...A DRAMATIC CHANGE COMPARED TO THE MID
SUMMER-LIKE HEAT THAT WE SAW EARLIER IN THE WEEK.
TONIGHT...SCATTERED RAIN SHOWERS SHOULD DIMINISH WITH THE LOSS OF
DAYLIGHT INDUCED MIXING...ALTHOUGH A LINGERING RESPONSE FROM LAKE
ONTARIO MAY LAST THROUGH THE FIRST HALF OF THE NIGHT.
OTHERWISE...EXPECT MOSTLY CLOUDY SKIES TO PREVAIL AS THE NORTHWEST
UPSLOPE FLOW REMAINS INTACT. THE CLOUD COVER WILL LIKELY PRECLUDE
THE DEVELOPMENT OF FROST ACROSS THE SOUTHERN TIER WHERE TEMPERATURES
MAY DIP INTO THE UPPER 30S BEFORE DAYBREAK. THE REST OF THE AREA
WILL SEE TEMPERATURES COOLING INTO THE LOWER AND MID 40S.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
ON SATURDAY A DEEP MID LEVEL TROUGH WILL DRIFT EAST ACROSS NEW
ENGLAND WITH ITS INFLUENCE ON OUR REGION DIMINISHING AS SURFACE HIGH
PRESSURE BUILDS INTO THE LOWER LAKES. LINGERING NORTHERLY FLOW ALOFT
MAY KEEP A FEW CLOUDS DURING THE MORNING ESPECIALLY SOUTHEAST OF
LAKE ONTARIO AND ACROSS HIGHER TERRAIN...BUT THESE SHOULD YIELD TO
INCREASING SUNSHINE DURING THE DAY AS SUBSIDENCE AND DRYING BEGIN TO
DOMINATE. 850MB TEMPS RECOVER TO AROUND +5C BY AFTERNOON WHICH WILL
SUPPORT HIGHS IN THE MID 60S AT LOWER ELEVATIONS AND AROUND 60
ACROSS HIGHER TERRAIN...STILL ABOUT 5-8 DEGREES BELOW AVERAGE.
SATURDAY NIGHT SURFACE HIGH PRESSURE WILL DRIFT FROM THE LOWER LAKES
TO THE MID ATLANTIC STATES. THIS WILL BRING CLEAR SKIES AND LIGHT
WINDS TO THE REGION SETTING THE STAGE FOR A GOOD RADIATIONAL COOLING
NIGHT. EVEN THOUGH TEMPERATURES ALOFT WILL BE MODERATING...STRONG
DIURNAL COOLING WILL SUPPORT LOWS IN THE 40S ON THE LAKE PLAINS WITH
SOME 30S ACROSS THE INTERIOR SOUTHERN TIER AND WELL EAST OF LAKE
ONTARIO. SOME OF THE COOLEST VALLEYS OF THE SOUTHERN TIER AND THE
TUG HILL REGION MAY SEE JUST A LITTLE PATCHY LIGHT FROST. THE STRONG
COOLING WILL ALSO SUPPORT TYPICAL RIVER VALLEY FOG ACROSS THE
SOUTHERN TIER.
ON SUNDAY SOUTHWEST RETURN FLOW WILL DEVELOP BETWEEN THE DEPARTING
HIGH AND THE NEXT APPROACHING COLD FRONT. THIS WILL BRING
TEMPERATURES BACK TO VERY NEAR AVERAGE WITH LOWER 70S AT LOWER
ELEVATIONS AND MID TO UPPER 60S ACROSS HIGHER TERRAIN. INCREASING
UPPER LEVEL DIVERGENCE AND SOME LEAD MID LEVEL SHORTWAVE ENERGY WILL
BRING AN INCREASE IN CIRRUS LEVEL CLOUDINESS DURING THE DAY WITH
MORNING SUNSHINE FADING BEHIND INCREASING HIGH CLOUDS.
SUNDAY NIGHT AND EARLY MONDAY A RE-ENFORCING TROUGH WILL DIG INTO
QUEBEC AND FORCE ANOTHER SEASONABLY STRONG COLD FRONT ACROSS THE
REGION. UPPER LEVEL SUPPORT IS QUITE STRONG WITH A WELL DEFINED
SHORTWAVE DIGGING THROUGH THE BASE OF THE TROUGH AND PROVIDING LARGE
SCALE ASCENT AS DPVA SPREADS INTO THE LOWER LAKES LATER SUNDAY
NIGHT. A 100+ KNOT UPPER LEVEL JET OVER QUEBEC WILL ALSO BE IN A
POSITION TO PLACE THE LOWER LAKES IN THE FAVORABLE RIGHT ENTRANCE
REGION...BRINGING A PERIOD OF ORGANIZED UPPER LEVEL DIVERGENCE. THE
FRONT WILL NOT BE MOISTURE RICH BY ANY MEANS...BUT WILL HAVE A PLUME
OF PWAT AROUND 1 INCH TO WORK WITH. GIVEN THE STRONG DYNAMICS
SUPPORTING THE LOW LEVEL FRONTAL BOUNDARY...HAVE INCREASED POPS INTO
THE HIGH CHANCE RANGE FOR LATER SUNDAY NIGHT.
MONDAY MORNING THE FRONT WILL EXIT THE AREA TO THE SOUTHEAST WITH
ANY LINGERING SHOWERS TAPERING OFF FROM NORTHWEST TO SOUTHEAST. THE
AIRMASS BECOMES COLD ENOUGH FOR SOME LAKE ENHANCEMENT JUST BEHIND
THE FRONT...AND THIS MAY CAUSE SHOWERS TO LINGER FOR A FEW EXTRA
HOURS MAINLY SOUTHEAST OF LAKE ONTARIO FROM ROCHESTER TO OSWEGO
COUNTY. LATER MONDAY THE AIRMASS QUICKLY DRIES AS STRONG HIGH
PRESSURE BUILDS INTO THE CENTRAL LAKES WITH INCREASING SUBSIDENCE
BRINGING A RAPID END TO ANY LAKE EFFECT SHOWERS THAT DO FORM. THIS
SHOULD ALSO BRING AT LEAST SOME LIMITED SUNSHINE DURING THE
AFTERNOON...ALTHOUGH WITH CHILLY NORTHWEST FLOW ALOFT CLOUDS MAY
CLEAR SLOWER THAN MODEL GUIDANCE CURRENTLY INDICATES. 850MB TEMPS
FALL TO AROUND +4C...AND THIS WILL BRING HIGHS BACK DOWN TO AROUND
60 AT LOWER ELEVATIONS AND MID TO UPPER 50S ACROSS HIGHER TERRAIN.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE ROLLER COASTER RIDE OF TEMPERATURES WILL CONTINUE THROUGH THE
LONG TERM AS THE PATTERN ACROSS NORTH AMERICA REMAINS PROGRESSIVE
WITH PERIODS OF MODERATE AMPLIFICATION SEPARATED BY BRIEF PERIODS OF
ZONAL FLOW. AROUND THE MIDDLE OF NEXT WEEK THE PATTERN WILL BECOME
ZONAL...WHICH WILL ALLOW HEIGHT RISES AND WARMER TEMPERATURES TO
SPREAD EAST INTO THE OHIO VALLEY AND GREAT LAKES.
LOOKING AT THE DETAILS...MONDAY NIGHT HIGH PRESSURE WILL BUILD INTO
THE LOWER LAKES AND COMBINE WITH A COOL AIRMASS TO BRING ANOTHER
CHILLY NIGHT. IF CURRENT MODEL TEMPERATURE GUIDANCE IS CLOSE WE MAY
HAVE SOME MORE FROST IN THE COOLER SOUTHERN TIER VALLEYS AND WELL
EAST OF LAKE ONTARIO.
HIGH PRESSURE DRIFTS TO THE EAST COAST TUESDAY THROUGH WEDNESDAY
WITH TEMPERATURES MODERATING SOME ON TUESDAY...THEN TO AT OR ABOVE
AVERAGE BY WEDNESDAY AS RETURN FLOW INCREASES. FURTHER WARMING WILL
MOVE IN BY THURSDAY...BUT THIS WILL BE ACCOMPANIED BY INCREASING
RAIN CHANCES AS WARM ADVECTION AND DEEPER MOISTURE SPREAD INTO THE
REGION.
LOOKING FURTHER AHEAD...BIG DISCREPANCIES IN MODEL GUIDANCE BY NEXT
FRIDAY INTO THE FOLLOWING WEEKEND. THE NEW 00Z ECMWF DIGS ANOTHER
SHARP TROUGH INTO THE NORTHEAST WITH A FRESH SHOT OF COOL AIR...
WHILE THE 00Z GFS REMAINS MORE ZONAL WITH MILD TEMPERATURES. THE
MAJORITY OF 00Z GEFS ENSEMBLE MEMBERS SUPPORT THE OPERATIONAL GFS
SOLUTION...WITH ONLY A FEW SUGGESTING A DEEPER EASTERN TROUGH. THE
RECENT TREND HAS BEEN FOR TROUGH AMPLIFICATION IN THE NORTHEAST...
SO TIME WILL TELL IF THE ECMWF IS THE FIRST TO CAPTURE THE NEXT
TROUGH AMPLIFICATION...OR IF THIS RUN IS JUST AN INCORRECT OUTLIER.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
A NORTHWEST FLOW OF COLDER AIR WILL CONTINUE TO MOVE ACROSS THE AREA
TODAY. THE COLDER AIR AND LINGERING LOW LEVEL MOISTURE BEHIND THE
DEPARTED COLD FRONT WILL CAUSE WIDESPREAD MVFR CIGS DUE TO UPSLOPE
FLOW. A SLOW IMPROVEMENT IS CIGS IS EXPECTED WITH TIME.
OUTLOOK...
SATURDAY THROUGH TUESDAY...VFR.
&&
.MARINE...
SMALL CRAFT ADVISORIES REMAIN IN PLACE ALONG THE SOUTHERN SHORES OF
LAKE ONTARIO AND HAVE BEEN EXTENDED TO THE EASTERN SHORES OF LAKE
ERIE...FROM DUNKIRK TO RIPELY. THESE CONDITIONS WILL LAST THROUGH
TONIGHT...ESPECIALLY ON LAKE ONTARIO WHERE THE NORTHWEST FLOW OF
UNSEASONABLY COOL AIR WILL ALLOW HIGHER WIND GUSTS TO MIX DOWN TO
THE LAKE SURFACE.
WIND AND WAVES WILL SUBSIDE A BIT ON SATURDAY AS HIGH PRESSURE
BUILDS EAST ACROSS THE LOWER LAKES.
CONDITIONS OVER THE LAKES WILL ALSO BE FAVORABLE FOR THE DEVELOPMENT
OF WATERSPOUTS THIS MORNING INTO THE EARLY AFTERNOON.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT SATURDAY FOR LEZ040.
SMALL CRAFT ADVISORY UNTIL 5 AM EDT SATURDAY FOR
LOZ042>044.
&&
$$
SYNOPSIS...TJP
NEAR TERM...TJP/ZAFF
SHORT TERM...HITCHCOCK
LONG TERM...HITCHCOCK
AVIATION...TJP/ZAFF
MARINE...TJP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
653 AM EDT FRI SEP 13 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA TODAY. CANADIAN HIGH PRESSURE
WILL BRING COOLER CONDITIONS FOR THE WEEKEND. A SECOND CANADIAN HIGH
WILL DROP SOUTHEAST INTO THE REGION EARLY NEXT WEEK...BRINGING A
REINFORCEMENT OF DRY AND MILD AIR FOR MUCH OF THE UPCOMING WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...THE RADAR REMAINS CLEAR ACROSS MY FORECAST
AREA WITH THE ONLY SHOWER ACTIVITY SHOWING UP WELL EAST AND
NORTHEAST OF WILMINGTON. I AM DROPPING POPS TO 10 PERCENT INLAND FOR
THE REMAINDER OF THE DAY...BUT WILL MAINTAIN THE 20-30 PERCENT
CHANCE OF MID-LATE DAY CONVECTION ALONG & EAST OF THE SEABREEZE. THE
LATEST HRRR RUN SHOWS A NARROW STRIP OF INCREASED DEWPOINTS AND
SURFACE-BASED CAPE VALUES DEVELOPING IN THE 18-22Z TIME FRAME AS THE
HUMID MARINE AIRMASS MOVES ONSHORE. NO SIGNIFICANT CHANGES ARE
NEEDED TO OTHER FORECAST ELEMENTS. PREVIOUS DISCUSSION FROM 300 AM
FOLLOWS...
THE UPPER AIR PATTERN HAS A RIDGE ACROSS THE CENTRAL ROCKIES WITH A
DEEP TROUGH ALONG THE EAST COAST. A SHORTWAVE DISTURBANCE DIPPING
INTO THE EAST COAST TROUGH WILL HELP PUSH A COLD FRONT INTO THE
EASTERN CAROLINAS TODAY. FAIRLY DRY CONDITIONS ALOFT...MARGINAL
MID-LEVEL LAPSE RATES...AND UNFAVORABLE JET DYNAMICS SHOULD HELP
KEEP MOST AREAS DRY. THERE IS A SLIGHT CHANCE OF A SHOWER OR T-STORM
INLAND THIS MORNING AS A PREFRONTAL TROUGH AND THE ACTUAL COLD FRONT
ARRIVE. POTENTIAL FOR SHOWERS OR T-STORMS THEN SHIFTS TO THE COAST
BY MID-TO-LATE AFTERNOON AS THE FRONT COLLIDES WITH THE SEABREEZE
BOUNDARY. THE SEABREEZE SHOULD THROW BETTER BOUNDARY LAYER MOISTURE
INLAND FOR THE SUN TO WORK ON... GENERATING A NARROW ZONE OF CAPE AS
HIGH AS 1500 J/KG. FORECAST POPS ARE NO HIGHER THAN ABOUT 30%
ANYWHERE TODAY.
THERE IS A FAIRLY LARGE DIFFERENCE IN FORECAST HIGHS TODAY BETWEEN
THE WARM GFS AND THE COOLER NAM/ECMWF. IN SIMILAR SITUATIONS EARLIER
IN THE SUMMER THE GFS HAS BEEN THE CLEAR WINNER...AND THIS APPEARS
TO BE THE WAY TO GO TODAY...PARTICULARLY GIVEN THE WARM START WE
WILL HAVE AT SUNRISE. THIS MEANS HIGHS SHOULD REACH 90 INLAND...WITH
MID TO UPPER 80S AT THE COAST.
COOLER AND DRIER AIR WILL PUSH IN BEHIND THE FRONT TONIGHT AS WINDS
SHIFT TO THE NORTH. WHILE I WOULD LIKE TO FORECAST CLEARING SKIES...
IT APPEARS A LAYER OF MOISTURE WILL BECOME TRAPPED ABOVE THE FRONTAL
SURFACE AND BELOW THE BUILDING SUBSIDENCE INVERSION ALOFT. THIS
COULD LEAD TO...IF THE 00Z NAM IS RIGHT...NEARLY OVERCAST CONDITIONS
WITH WARMER OVERNIGHT TEMPERATURES DUE TO LACK OF RADIATIONAL
COOLING. THE GFS HAS DRIER AIR IN THE 900-700 MB LAYER AND NOT
SURPRISINGLY IS FORECASTING MUCH LOWER TEMPERATURES TONIGHT. I HAVE
SPLIT THE DIFFERENCE WITH FORECAST LOWS...RANGING FROM THE LOWER 60S
FROM BURGAW THROUGH ELIZABETHTOWN...LUMBERTON AND BENNETTSVILLE...
TO THE MID 60S MOST ELSEWHERE. THE BEACHES WILL PROBABLY REMAIN IN
THE UPPER 60S FOR LOWS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...ESSENTIALLY A TEMPERATURE FORECAST AS A
PROGRESSIVE MID LEVEL TROUGH DOMINATES SATURDAY WITH A ZONAL FLOW
QUICKLY SETTING UP SUNDAY. AT THE SURFACE...HIGH PRESSURE WILL MOVE
FROM THE MIDWEST TO OFFSHORE WITH AN ELONGATED WEST/EAST AXIS
SUNDAY. WITH PRECIPITABLE WATER VALUES DOWN TO JUST OVER AN
INCH...POPS WILL NOT BE AN ISSUE. SOUNDINGS SHOW ENOUGH MOISTURE AND
STEEP LOW LEVEL LAPSE RATES FOR STRATOCUMULUS TO DEVELOP MIDDAY
SATURDAY AND SUNDAY BUT THAT IS ABOUT IT. TEMPERATURE GUIDANCE HAS
IMPROVED DRAMATICALLY WHEN COMPARED TO THIS TIME LAST NIGHT AND
THERE IS VERY LITTLE DIFFERENCE BETWEEN THE MET AND NAM NUMBERS. I
DID TWEAK UP SUNDAY MORNING LOWS TO MATCH THIS TREND AS IT ALWAYS
SEEMS A GOOD PLAY TO GO WARMER WITH THE BOUNDARY LAYER NOT
COMPLETELY
DECOUPLED...OTHERWISE NO CHANGES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...THE MID LEVEL PATTERN WILL TRANSITION FROM A
MODEST AND PROGRESSIVE EAST COAST TROUGH TO ONE MORE RESEMBLING MID
SUMMER FOR TUESDAY THROUGH THURSDAY. THIS IS MOSTLY A WEST TO EAST
FLOW. THE TROUGH WILL ALLOW A MODEST SECONDARY SURGE OF MOSTLY DRIER
AIR INTO THE AREA TUESDAY WHICH WILL BRIEFLY DROP TEMPERATURES AND
DEWPOINTS A COUPLE OF DEGREES. READINGS RECOVER QUICKLY WEDNESDAY
AND THURSDAY VIA MOSTLY AIR MASS MODIFICATION AS THE SURFACE HIGH
MOVES BASICALLY EASTWARD. REGARDING POPS...THE ONLY OPPORTUNITIES
AND THEY ARE SMALL ARE WITH THE SURGE TUESDAY AND SEA BREEZE
ACTIVITY WEDNESDAY AND THURSDAY. ALL VALUES ARE SLIGHT CHANCE AND
THIS IS PROBABLY BEING GENEROUS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...SATELLITE SHOWS BROKEN HIGH CLOUDS OVER THE REGION AHEAD
OF A COLD FRONT THAT WILL DROP THROUGH LATER TODAY. LITTLE TO NO
WEATHER ASSOCIATED WITH IT...AN ISOLATED SHOWER PERHAPS ALTHOUGH
THERE IS LITTLE MOISTURE ASSOCIATED WITH THE SYSTEM. WEST WINDS THIS
MORNING WILL SHIFT TO THE NORTH NORTHEAST BY LATE AFTERNOON TO EARLY
EVENING. BEHIND THE FRONT...TIME HEIGHT INDICATES A VFR STRATA CU
CEILING WILL SET UP TONIGHT WITH NORTHEAST WINDS REMAINING AROUND 10
KTS THROUGH THE NIGHTTIME HOURS. NO FOG IS EXPECTED DUE TO GOOD
MIXING.
EXTENDED OUTLOOK...VFR WILL PREVAIL THROUGH THE EXTENDED PERIOD.
VERY SLIGHT CHANCE OF SHOWERS LATE MONDAY INTO EARLY TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...INCREASED FORECAST WINDS A COUPLE OF KNOTS TO
ACCOUNT FOR SOME 19-22 KNOT GUSTS BEING REPORTED AT FRYING PAN
SHOALS AND BALD HEAD ISLAND RESPECTIVELY. THE PERIOD OF STRONGEST
WINDS SHOULD BE OCCURRING NOW...WITH A RATHER RAPID DIMINISHING
TREND IN WIND SPEEDS DEVELOPING AFTER 10 A.M. SEAS HAVE BUILT TO 4
FT AT THE FRYING PAN SHOALS BUOY...WITH 3 FT REPORTED CLOSER TO
SHORE.
NO OTHER SIGNIFICANT CHANGES ARE NEEDED TO THE FORECAST. PREVIOUS
DISCUSSION FROM 300 AM FOLLOWS...
A COLD FRONT CURRENTLY LOCATED IN THE NC AND VA MOUNTAINS WILL MOVE
SOUTHEASTWARD TODAY...REACHING THE COASTAL WATERS LATE THIS EVENING.
UNTIL THEN...THE PRESSURE GRADIENT HAS TIGHTENED UP EARLY THIS
MORNING IN ADVANCE OF A SURFACE TROUGH ACROSS EASTERN NORTH
CAROLINA. THE RESULT HAS BEEN WINDS AROUND 15 KNOTS WITH GUSTS
MEASURED AS HIGH AS 19 KNOTS AT THE FRYING PAN SHOALS BUOY. LOOK FOR
WINDS TO TURN MORE WESTERLY AND DIMINISH TO 10 KT OR LESS LATER THIS
MORNING BEHIND THE TROUGH. INLAND TEMPERATURES WILL AGAIN PUSH
TOWARD 90 DEGREES THIS AFTERNOON CREATING A SEABREEZE CIRCULATION
WITH NEARSHORE WINDS BACKING TO THE SOUTH. ONCE THE FRONT ARRIVES
LATE THIS EVENING WINDS WILL TURN NORTH- NORTHEAST AND INCREASE IN A
COOL SURGE AHEAD OF CANADIAN HIGH PRESSURE...REACHING 15-20 KT BY
SUNRISE SATURDAY.
SEAS CURRENTLY AROUND 3 FT SHOULD DIMINISH TO 2 FT THIS AFTERNOON.
HOWEVER SEAS WILL AGAIN BUILD WITH THE NE SURGE OVERNIGHT...REACHING
3-4 FT BY DAYBREAK.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...A NORTHEASTERLY FLOW WILL PREVAIL THROUGH MOST
OF THE PERIOD. LATE SUNDAY WINDS WILL ACQUIRE A MORE EASTERLY
COMPONENT. MODEL GUIDANCE REMAINS CONSISTENT WITH REGARDS TO WIND
SPEEDS WITH A SOLID 15-20 KNOTS SATURDAY SLOWLY DIMINISHING SUNDAY.
SIGNIFICANT SEAS WILL SEE A RANGE OF 3-5 FEET SATURDAY FALLING DOWN
TO 2-4 FEET SUNDAY. A SCEC HEADLINE MAY BE NEEDED SATURDAY.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...EARLY NEXT WEEK IS SHAPING UP TO OFFER NICE
CONDITIONS FOR THE MARINE COMMUNITY...ESPECIALLY MONDAY. AS HIGH
PRESSURE WEAKENS AND MOVES OFFSHORE...NORTHEAST WINDS WILL TURN TO
MORE EASTERLY WITH SPEEDS TEN KNOTS OR BELOW. A SECONDARY BOUNDARY
WILL INCREASE SPEEDS A BIT TUESDAY AND TURN THE WINDS BACK TO
NORTHEAST...BUT STILL MANAGEABLE AT 10-15 KNOTS. WAVEWATCH SEAS ARE
NOW SHOWING A SUBTLE LONG PERIOD SWELL COMPONENT AT THE END OF THE
PERIOD...MOST LIKELY FROM GABRIELLE BUT IT SHOULD NOT IMPACT
SIGNIFICANT SEAS DRAMATICALLY. OVERALL 2-3 FEET SHOULD SUFFICE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
647 AM EDT FRI SEP 13 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA TODAY. CANADIAN HIGH PRESSURE
WILL BRING COOLER CONDITIONS FOR THE WEEKEND. A SECOND CANADIAN HIGH
WILL DROP SOUTHEAST INTO THE REGION EARLY NEXT WEEK...BRINGING A
REINFORCEMENT OF DRY AND MILD AIR FOR MUCH OF THE UPCOMING WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...THE RADAR REMAINS CLEAR ACROSS MY FORECAST
AREA WITH THE ONLY SHOWER ACTIVITY SHOWING UP WELL EAST AND
NORTHEAST OF WILMINGTON. I AM DROPPING POPS TO 10 PERCENT INLAND FOR
THE REMAINDER OF THE DAY...BUT WILL MAINTAIN THE 20-30 PERCENT
CHANCE OF MID-LATE DAY CONVECTION ALONG & EAST OF THE SEABREEZE. THE
LATEST HRRR RUN SHOWS A NARROW STRIP OF INCREASED DEWPOINTS AND
SURFACE-BASED CAPE VALUES DEVELOPING IN THE 18-22Z TIME FRAME AS THE
HUMID MARINE AIRMASS MOVES ONSHORE. NO SIGNIFICANT CHANGES ARE
NEEDED TO OTHER FORECAST ELEMENTS. PREVIOUS DISCUSSION FROM 300 AM
FOLLOWS...
THE UPPER AIR PATTERN HAS A RIDGE ACROSS THE CENTRAL ROCKIES WITH A
DEEP TROUGH ALONG THE EAST COAST. A SHORTWAVE DISTURBANCE DIPPING
INTO THE EAST COAST TROUGH WILL HELP PUSH A COLD FRONT INTO THE
EASTERN CAROLINAS TODAY. FAIRLY DRY CONDITIONS ALOFT...MARGINAL
MID-LEVEL LAPSE RATES...AND UNFAVORABLE JET DYNAMICS SHOULD HELP
KEEP MOST AREAS DRY. THERE IS A SLIGHT CHANCE OF A SHOWER OR T-STORM
INLAND THIS MORNING AS A PREFRONTAL TROUGH AND THE ACTUAL COLD FRONT
ARRIVE. POTENTIAL FOR SHOWERS OR T-STORMS THEN SHIFTS TO THE COAST
BY MID-TO-LATE AFTERNOON AS THE FRONT COLLIDES WITH THE SEABREEZE
BOUNDARY. THE SEABREEZE SHOULD THROW BETTER BOUNDARY LAYER MOISTURE
INLAND FOR THE SUN TO WORK ON... GENERATING A NARROW ZONE OF CAPE AS
HIGH AS 1500 J/KG. FORECAST POPS ARE NO HIGHER THAN ABOUT 30%
ANYWHERE TODAY.
THERE IS A FAIRLY LARGE DIFFERENCE IN FORECAST HIGHS TODAY BETWEEN
THE WARM GFS AND THE COOLER NAM/ECMWF. IN SIMILAR SITUATIONS EARLIER
IN THE SUMMER THE GFS HAS BEEN THE CLEAR WINNER...AND THIS APPEARS
TO BE THE WAY TO GO TODAY...PARTICULARLY GIVEN THE WARM START WE
WILL HAVE AT SUNRISE. THIS MEANS HIGHS SHOULD REACH 90 INLAND...WITH
MID TO UPPER 80S AT THE COAST.
COOLER AND DRIER AIR WILL PUSH IN BEHIND THE FRONT TONIGHT AS WINDS
SHIFT TO THE NORTH. WHILE I WOULD LIKE TO FORECAST CLEARING SKIES...
IT APPEARS A LAYER OF MOISTURE WILL BECOME TRAPPED ABOVE THE FRONTAL
SURFACE AND BELOW THE BUILDING SUBSIDENCE INVERSION ALOFT. THIS
COULD LEAD TO...IF THE 00Z NAM IS RIGHT...NEARLY OVERCAST CONDITIONS
WITH WARMER OVERNIGHT TEMPERATURES DUE TO LACK OF RADIATIONAL
COOLING. THE GFS HAS DRIER AIR IN THE 900-700 MB LAYER AND NOT
SURPRISINGLY IS FORECASTING MUCH LOWER TEMPERATURES TONIGHT. I HAVE
SPLIT THE DIFFERENCE WITH FORECAST LOWS...RANGING FROM THE LOWER 60S
FROM BURGAW THROUGH ELIZABETHTOWN...LUMBERTON AND BENNETTSVILLE...
TO THE MID 60S MOST ELSEWHERE. THE BEACHES WILL PROBABLY REMAIN IN
THE UPPER 60S FOR LOWS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...ESSENTIALLY A TEMPERATURE FORECAST AS A
PROGRESSIVE MID LEVEL TROUGH DOMINATES SATURDAY WITH A ZONAL FLOW
QUICKLY SETTING UP SUNDAY. AT THE SURFACE...HIGH PRESSURE WILL MOVE
FROM THE MIDWEST TO OFFSHORE WITH AN ELONGATED WEST/EAST AXIS
SUNDAY. WITH PRECIPITABLE WATER VALUES DOWN TO JUST OVER AN
INCH...POPS WILL NOT BE AN ISSUE. SOUNDINGS SHOW ENOUGH MOISTURE AND
STEEP LOW LEVEL LAPSE RATES FOR STRATOCUMULUS TO DEVELOP MIDDAY
SATURDAY AND SUNDAY BUT THAT IS ABOUT IT. TEMPERATURE GUIDANCE HAS
IMPROVED DRAMATICALLY WHEN COMPARED TO THIS TIME LAST NIGHT AND
THERE IS VERY LITTLE DIFFERENCE BETWEEN THE MET AND NAM NUMBERS. I
DID TWEAK UP SUNDAY MORNING LOWS TO MATCH THIS TREND AS IT ALWAYS
SEEMS A GOOD PLAY TO GO WARMER WITH THE BOUNDARY LAYER NOT
COMPLETELY
DECOUPLED...OTHERWISE NO CHANGES.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...THE MID LEVEL PATTERN WILL TRANSITION FROM A
MODEST AND PROGRESSIVE EAST COAST TROUGH TO ONE MORE RESEMBLING MID
SUMMER FOR TUESDAY THROUGH THURSDAY. THIS IS MOSTLY A WEST TO EAST
FLOW. THE TROUGH WILL ALLOW A MODEST SECONDARY SURGE OF MOSTLY DRIER
AIR INTO THE AREA TUESDAY WHICH WILL BRIEFLY DROP TEMPERATURES AND
DEWPOINTS A COUPLE OF DEGREES. READINGS RECOVER QUICKLY WEDNESDAY
AND THURSDAY VIA MOSTLY AIR MASS MODIFICATION AS THE SURFACE HIGH
MOVES BASICALLY EASTWARD. REGARDING POPS...THE ONLY OPPORTUNITIES
AND THEY ARE SMALL ARE WITH THE SURGE TUESDAY AND SEA BREEZE
ACTIVITY WEDNESDAY AND THURSDAY. ALL VALUES ARE SLIGHT CHANCE AND
THIS IS PROBABLY BEING GENEROUS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 06Z...A COLD FRONT OVER THE WESTERN CAROLINAS WILL CONTINUE
APPROACHING THE AREA THIS MORNING. SURFACE WINDS 4-8 KTS WILL KEEP
THE BOUNDARY LAYER MIXED...SO DO NOT ANTICIPATE ANY FOG ISSUES. HAVE
INCLUDED VCSH THIS MORNING AS HI-RES GUIDANCE STILL SHOWS SOME
ISOLATED SHRA DEVELOPING AS THE FRONT APPROACHES. BY MIDDAY THE
FRONT SHOULD PUSH THROUGH OUR AREA...AND THE WINDS WILL VEER TO THE
NORTH OR NORTHWEST. THE GFS AND NAM CONTINUE TO HINT AT SOME
SHOWERS/T-STORMS ALONG THE COAST DURING THE AFTN HOURS...AS SFC
CONVERGENCE ALONG THE SEA BREEZE PROMOTES SHOWER DEVELOPMENT. DEEP
CONVECTION WILL BE TOUGH GIVEN THE DRIER AIR ALOFT AND THE MID-LEVEL
INVERSION...BUT HAVE ADDED VCSH FOR THE AFTN AT KILM/KCRE/KMYR AS
SHOWERS CANNOT BE RULED OUT. AFTER 21Z...PCPN ACTIVITY WILL REMAIN
OFFSHORE AND THE SKIES SHOULD BEGIN CLEARING OUT.
EXTENDED OUTLOOK...VFR WILL PREVAIL THROUGH THE EXTENDED PERIOD.
VERY SLIGHT CHANCE OF SHOWERS LATE MONDAY INTO EARLY TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...INCREASED FORECAST WINDS A COUPLE OF KNOTS TO
ACCOUNT FOR SOME 19-22 KNOT GUSTS BEING REPORTED AT FRYING PAN
SHOALS AND BALD HEAD ISLAND RESPECTIVELY. THE PERIOD OF STRONGEST
WINDS SHOULD BE OCCURRING NOW...WITH A RATHER RAPID DIMINISHING
TREND IN WIND SPEEDS DEVELOPING AFTER 10 A.M. SEAS HAVE BUILT TO 4
FT AT THE FRYING PAN SHOALS BUOY...WITH 3 FT REPORTED CLOSER TO
SHORE.
NO OTHER SIGNIFICANT CHANGES ARE NEEDED TO THE FORECAST. PREVIOUS
DISCUSSION FROM 300 AM FOLLOWS...
A COLD FRONT CURRENTLY LOCATED IN THE NC AND VA MOUNTAINS WILL MOVE
SOUTHEASTWARD TODAY...REACHING THE COASTAL WATERS LATE THIS EVENING.
UNTIL THEN...THE PRESSURE GRADIENT HAS TIGHTENED UP EARLY THIS
MORNING IN ADVANCE OF A SURFACE TROUGH ACROSS EASTERN NORTH
CAROLINA. THE RESULT HAS BEEN WINDS AROUND 15 KNOTS WITH GUSTS
MEASURED AS HIGH AS 19 KNOTS AT THE FRYING PAN SHOALS BUOY. LOOK FOR
WINDS TO TURN MORE WESTERLY AND DIMINISH TO 10 KT OR LESS LATER THIS
MORNING BEHIND THE TROUGH. INLAND TEMPERATURES WILL AGAIN PUSH
TOWARD 90 DEGREES THIS AFTERNOON CREATING A SEABREEZE CIRCULATION
WITH NEARSHORE WINDS BACKING TO THE SOUTH. ONCE THE FRONT ARRIVES
LATE THIS EVENING WINDS WILL TURN NORTH- NORTHEAST AND INCREASE IN A
COOL SURGE AHEAD OF CANADIAN HIGH PRESSURE...REACHING 15-20 KT BY
SUNRISE SATURDAY.
SEAS CURRENTLY AROUND 3 FT SHOULD DIMINISH TO 2 FT THIS AFTERNOON.
HOWEVER SEAS WILL AGAIN BUILD WITH THE NE SURGE OVERNIGHT...REACHING
3-4 FT BY DAYBREAK.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...A NORTHEASTERLY FLOW WILL PREVAIL THROUGH MOST
OF THE PERIOD. LATE SUNDAY WINDS WILL ACQUIRE A MORE EASTERLY
COMPONENT. MODEL GUIDANCE REMAINS CONSISTENT WITH REGARDS TO WIND
SPEEDS WITH A SOLID 15-20 KNOTS SATURDAY SLOWLY DIMINISHING SUNDAY.
SIGNIFICANT SEAS WILL SEE A RANGE OF 3-5 FEET SATURDAY FALLING DOWN
TO 2-4 FEET SUNDAY. A SCEC HEADLINE MAY BE NEEDED SATURDAY.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...EARLY NEXT WEEK IS SHAPING UP TO OFFER NICE
CONDITIONS FOR THE MARINE COMMUNITY...ESPECIALLY MONDAY. AS HIGH
PRESSURE WEAKENS AND MOVES OFFSHORE...NORTHEAST WINDS WILL TURN TO
MORE EASTERLY WITH SPEEDS TEN KNOTS OR BELOW. A SECONDARY BOUNDARY
WILL INCREASE SPEEDS A BIT TUESDAY AND TURN THE WINDS BACK TO
NORTHEAST...BUT STILL MANAGEABLE AT 10-15 KNOTS. WAVEWATCH SEAS ARE
NOW SHOWING A SUBTLE LONG PERIOD SWELL COMPONENT AT THE END OF THE
PERIOD...MOST LIKELY FROM GABRIELLE BUT IT SHOULD NOT IMPACT
SIGNIFICANT SEAS DRAMATICALLY. OVERALL 2-3 FEET SHOULD SUFFICE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS PUEBLO CO
353 PM MDT FRI SEP 13 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 335 PM MDT FRI SEP 13 2013
TONIGHT...NEXT DISTURBANCE IS MOVING NORTHEAST ACROSS THE CWA.
LINE OF CONVECTION HAS DEVELOPED OVER BENT AND EASTERN LAS ANIMAS
COUNTY AND IT IS MOVING TO THE NORTHEAST AT 25 TO 35 KNOTS. THE 12Z
AND 18Z NAM SUGGESTED THE HEAVIEST PRECIPITATION WOULD MOVE ACROSS
THE EASTERN PLAINS. SO FAR...THE CELLS HEADING TOWARDS EL PASO AND
TELLER COUNTIES ARE WEAK. HRRR HAS NOT BEEN DOING WELL TODAY...AS
18Z HRRR HAS MUCH MORE CONVECTION OVER EL PASO COUNTY AT THIS TIME.
BELIEVE THE NAM AND GFS HAS A BETTER HANDLE ON CONVECTION. WILL NOT
ISSUE A FLASH FLOOD WATCH FOR EL PASO AND TELLER COUNTIES THIS
EVENING...AS CHANCES FOR SLOWER MOVING CELLS WITH HEAVY RAINFALL IS
LOW. CANNOT TOTALLY RULE OUT A STRONG CELL OVER A BURN SCAR...BUT
CHANCES OF THIS HAPPENING ARE SMALL. CONVECTION OF THE CWA WILL
MOSTLY END BY MID EVENING. KEPT POPS OVERNIGHT AS SOME SHOWERS ARE
POSSIBLE WITH ABUNDANT MOISTURE AND CYCLONIC FLOW.
SATURDAY...TROUGH APPROACHES THE REGION FROM THE SOUTHWEST...AND
FLOW ALOFT TURNS MORE TO THE SOUTHWEST. STILL PLENTY OF MOISTURE
WITH BUFKIT SOUNDINGS SHOWING PRECIPITABLE WATERS OF 8 TENTHS OF AN
INCH AND GREATER. MAIN CHALLENGE FOR CONVECTION IS THE AMOUNT OF
INSTABILITY. NAM AND GFS SUGGEST THE GREATEST INSTABILITY WILL BE
OVER AND NEAR THE MOUNTAINS...AND HAVE HIGH SCATTERED TO SOME LIKELY
POPS DURING THE AFTERNOON. GIVEN THE ABUNDANT MOISTURE...SOME
STRONGER STORMS COULD PRODUCE LOCALLY HEAVY RAIN...WHICH COULD CAUSE
PROBLEMS ON THE BURN SCARS. GIVEN THE LACK OF DEEP UPSLOPE AND LACK
OF INSTABILITY...BELIEVE CHANCES FOR FLASH FLOODING OVER BURNS SCARS
AND OTHER SUSCEPTIBLE AREAS IS LOW ENOUGH TO NOT WARRANT A FLASH
FLOOD WATCH. --PGW--
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 335 PM MDT FRI SEP 13 2013
...NEXT HEAVY RAIN THREAT ARRIVES BY SUNDAY MORNING...
OLD UPPER TROUGH OPENS UP AND BEGINS TO MOVE EAST ACROSS COLORADO
SATURDAY. THERE IS STILL ADEQUATE MOISTURE FOR STORMS TO DEVELOP
IN THE AFTERNOON...BUT WITH THE TROUGH OPENING UP...THERE DOESN`T
SEEM TO BE ANYTHING TO REALLY FOCUS THE ENERGY AND GET ANYTHING
WIDESPREAD GOING. SO...GENERALLY ISOLATED TO SCATTERED COVERAGE OF
STORMS SATURDAY...MAINLY OVER THE MOUNTAINS. HEAVY RAIN POTENTIAL
WILL STILL EXIST...BUT AGAIN...MORE HIT AND MISS THAN IN RECENT
DAYS.
ON SUNDAY...WE WILL HAVE SOMETHING TO FOCUS THE PRECIPITATION
AGAIN. SUNDAY MORNING...AND POSSIBLY EVEN LATE SATURDAY NIGHT...
WE WILL HAVE A RATHER SIGNIFICANT COOL FRONT MOVE THROUGH THE
EASTERN PLAINS...ASSOCIATED WITH A SHORTWAVE MOVING THROUGH
THE CENTRAL UNITED STATES. THE COOL FRONT WILL FORCE UPSLOPE
FLOW AGAINST THE MOUNTAINS...TRIGGERING FAIRLY WIDESPREAD
PRECIPITATION...WITH EMBEDDED CONVECTION...FOR LOCALLY HEAVIER
PRECIP. SO...THIS DAY WILL BE A HIGH THREAT DAY AGAIN FOR
AREA BURN SCARS. AND...WITH THE RECENT SATURATION THAT HAS
OCCURRED...OTHER AREAS COULD SEE SOME PROBLEMS AS WELL. THIS
WILL LAST INTO SUNDAY NIGHT...MAINLY AFFECTING THE EASTERN
MOUNTAINS AND PLAINS.
MONDAY...WE START TO FINALLY TRANSITION OUT OF THIS PATTERN
INTO A MUCH DRIER ONE. COULD STILL BE SOME SPOTTY STUFF
AROUND TO CONTEND WITH MONDAY...BUT THE REST OF THE WEEK
DEFINITELY LOOKS MUCH DRIER AND WARMER AS A MUCH DRIER
WESTERLY FLOW ALOFT TAKES HOLD OVER COLORADO. LW
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 335 PM MDT FRI SEP 13 2013
ANTICIPATE SOUTHERLY COMPONENT FLOW AT KCOS THROUGHOUT THE
NIGHT...WHICH WOULD TEND TO KEEP MVFR CONDITIONS OVERNIGHT. FLOW AT
KPUB WILL HAVE ENOUGH OF A WESTERLY COMPONENT TO KEEP VFR CONDITIONS
OVERNIGHT. ON SATURDAY...ABUNDANT MOISTURE WILL REMAIN OVER THE
REGION. INSTABILITY WILL BE LIMITED...AND ONLY ANTICIPATE SCATTERED
AFTERNOON CONVECTION. --PGW--
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PGW
LONG TERM...LW
AVIATION...PGW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1124 AM MDT FRI SEP 13 2013
.UPDATE...
ISSUED AT 1012 AM MDT FRI SEP 13 2013
CANCELLED THE FLASH FLOOD WATCH EARLY AS THE RAIN HAS MOVED NORTH
OF EL PASO COUNTY AND ONLY SCATTERED LIGHT RAIN SHOWERS ARE
UPSTREAM OF THE REGION.
SATELLITE SHOWS ANOTHER DISTURBANCE OVER WESTERN NEW MEXICO MOVING
NORTHEAST...AND THIS DISTURBANCE WILL PASS OVER THE REGION BETWEEN
AROUND 4PM AND 8PM TODAY. HAVE SOME CONCERNS THAT THIS NEXT ROUND
OF STORMS COULD PRODUCE LOCALLY HEAVY RAINFALL. HRRR HAS BEEN TRENDING
SLIGHTLY STRONGER WITH THESE STORMS. HOWEVER...WINDS ALOFT HAVE
BECOME SOUTHWEST AT 15 TO 30 KNOTS. STORMS WHICH DEVELOP WILL WANT
TO MOVE TO THE NORTHEAST. AM NOT TOO CONCERNED ABOUT STORMS
TRAINING OVER ONE LOCATION. HOWEVER...STILL HAVE SOME CONCERNS
THAT STORMS COULD PRODUCE SPOTTY AREAS OF LOCALLY HEAVY RAIN. IF
ONE OF THESE SPOTTY STORMS STRIKES A BURN SCAR OR OTHER
SUSCEPTIBLE AREAS...FLASH FLOOD COULD OCCUR. HRRR KEEPS BAND OF
HEAVIER PRECIPITATION JUST NORTH OF THE PALMER DIVIDE WHERE IT WANTS
TO DEVELOP CONVECTION ALONG A BOUNDARY...LIKELY THE DENVER
CYCLONE.
WHAT TO DO ABOUT WATCHES. CURRENTLY...BELIEVE THREAT FOR HEAVY
RAIN NOT SUFFICIENTLY HIGH TO WARRANT EXTENDING THE FLASH FLOOD
WATCH. HOWEVER...THE SITUATION WILL BE MONITORED.
UPDATE ISSUED AT 512 AM MDT FRI SEP 13 2013
A STRONG SOUTHEAST WIND HAS DEVELOPED ALONG THE I-25 CORRIDOR IN
EL PASO AND PUEBLO COUNTIES...AND PRECIPITATION HAS INCREASED OVER
EL PASO COUNTY WITH UP TO AN INCH PER HOUR FALLING IN A VERY
NARROW BAND ACROSS COLORADO SPRINGS. LATEST FORECAST MODELS ARE
SHOWING THE POTENTIAL FOR SOME MODERATE TO HEAVY RAIN THROUGH THE
MORNING HOURS...SO HAVE ISSUED A FLASH FLOOD WATCH THRU 18Z FOR EL
PASO AND TELLER COUNTIES WHERE SOILS ARE ALREADY SATURATED AND
THERE WILL BE A THREAT TO THE WALDO CANYON AND BLACK FOREST BURN SCARS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM MDT FRI SEP 13 2013
RAIN COVERAGE OVR THE SERN PLAINS HAS DECREASED AND HAS BECOME
LIGHTER...WHILE PCPN OVR WESTERN PORTIONS HAS INCREASED TONIGHT WITH
GENERALLY LIGHT TO SOMETIMES MODERATE RAIN BEING REPORTED OVER THE
WEST FORK COMPLEX BURN SCAR. PCPN CONTINUES TO WORK ITS WAY
NORTHWARD FROM NM SO WL KEEP POPS IN THE LIKELY CATEGORY ACRS MOST
OF THE FORECAST AREA FOR THE MORNING HOURS. ALL INDICATIONS ARE
THAT PCPN THAT FALLS OVER EL PASO AND TELLER COUNTIES...WHERE THE
MOST SATURATED CONDITIONS ARE...WL MOSTLY BE ON THE LIGHT SIDE SO
CANCELED THE FF WATCH FOR THE I-25 CORRIDOR AT 3 AM.
THE UPR LOW WL CENTERED NR THE NV...UT AND ID BORDER REGION THRU
MUCH OF THE DAY. IT THEN BEGINS TO SHIFT EASTWARD OVERNIGHT AS IT
PHASES WITH AN UPR TROF WELL TO THE NORTH. THERE WL STILL BE A
PLUME OF MSTR OVR THE FORECAST AREA...ALONG WITH GOOD CHANCES FOR
PCPN...BUT ALL MODELS ARE SHOWING EXPECTED PCPN AMOUNTS BEING ON THE
LIGHTER SIDE TODAY. THAT DOES NOT MEAN THAT THERE WILL NOT BE SOME
LOCALLY HEAVY RAIN STILL WHICH COULD AGAIN CAUSE SOME FLASH
FLOODING.
TONIGHT PCPN CHANCES LOOK LIKE THEY WILL DECREASE...ESPECIALLY OVR
ERN CO. LATE TONIGHT A SHORTWAVE TROF IS EXPECTED TO APPROACH AND
THEN MOVE INTO SWRN CO AND COULD ENHANCE PCPN CHANCES OVR SRN
AREAS...SO WL GO WITH SOME HIGH SCT POPS IN THAT AREA. THE LOCAL
WRF MODEL SHOWS THE POTENTIAL FOR SOME HEAVY RAIN OVERNIGHT ON THE
WEST FORK COMPLEX BURN SCAR...WHILE THE NAM HAS LIGHTER AMOUNTS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM MDT FRI SEP 13 2013
PRIMARY LONGER TERM ISSUES INCLUDE POPS AND TEMPERATURES. LONGER
TERM COMPUTER SIMULATIONS AND FORECAST MODEL SOUNDINGS SUGGEST
THAT UNSETTLED AND GENERALLY COOL CONDITIONS SHOULD PREVAIL OVER
THE FORECAST DISTRICT INTO THIS WEEKEND BEFORE WARMER AND DRIER
CONDITIONS RETURN NEXT WEEK...ESPECIALLY FROM TUESDAY ONWARD.
AT THIS TIME...IT APPEARS THAT THE CWFA AREAL COVERAGE OF
PRECIPITATION ON SATURDAY WILL BE LESS THAN HAS BEEN NOTED PREVIOUS
FEW DAYS...ALTHOUGH LOCALLY HEAVY RAIN WILL STILL BE POSSIBLE AS
PRECIPITABLE WATER VALUES NEAR 1 INCH AT TIMES AND AREAS SUCH AS
THE RECENT BURN SCARS AND LOCATIONS THAT HAVE RECEIVED HEAVY
RAINFALL DURING THE PREVIOUS FEW DAYS WILL NEED TO BE MONITORED
FOR FLOODING/FLASH FLOODING CONCERNS.
THEN AN INCREASE IN COVERAGE OF PRECIPITATION IS ANTICIPATED ON
SUNDAY AS A NORTHERLY SURGE MOVES ACROSS EASTERN SECTIONS BY
SUNDAY MORNING INCREASING FORECAST PRECIPITABLE WATER VALUES TO
AROUND 1.10 INCHES OVER PORTIONS OF THE I-25 CORRIDOR. ONCE
AGAIN...LOCALIZED FLOODING/FLASH FLOODING ISSUES MAY
ARISE...ESPECIALLY OVER RECENT BURN SCAR AND PREVIOUS HEAVY RAIN
LOCATIONS. IN ADDITION...HIGHER MOUNTAIN LOCATIONS...GENERALLY
ABOVE 12000 FEET MAY EXPERIENCE SEVERAL INCHES OF SNOW FROM
EARLY SATURDAY MORNING INTO MONDAY MORNING.
DRIER AND WARMER CONDITIONS ARE THEN EXPECTED TO DEVELOP OVER THE
FORECAST DISTRICT...ESPECIALLY FROM TUESDAY INTO THURSDAY AS
FORECAST I-25 PRECIPITATION WATER VALUES DECREASE FROM 1.4 INCHES
AS OF THURSDAY NIGHT TO AROUND 0.50 INCHES BY NEXT WEDNESDAY. IN
ADDITION...FORECAST I-25 700 MB TEMPERATURES INCREASE FROM AN 8.8C
VALUE AT 00Z FRIDAY TO A 14.7C VALUE BY 00Z THURSDAY.
FINALLY...GENERALLY LOW-GRADE GRADIENT WINDS SHOULD CONTINUE
OVER THE FORECAST DISTRICT THROUGH NEXT THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1118 AM MDT FRI SEP 13 2013
SHORTWAVE OVER NM WILL CONTINUE TO MOVE NORTH-NORTHEAST AND WILL
BRING ANOTHER ROUND OF SHOWERS TO THE REGION. RAIN IS ALREADY
FALLING IN KALS...AND EXPECT SHOWERS TO MOVE INTO KPUB AND KCOS BY
EARLY TO MID AFTERNOON.
WITH SUSTAINED SOUTHERLY MOIST FLOW...KCOS WILL LIKELY REMAIN MVFR
THROUGHOUT THE DAY. LOCALLY HEAVIER SHOWERS MAY BRING KCOS DOWN TO
IFR FOR BRIEF PERIODS OF TIME.
SOME FOG MAY AFFECT KCOS AND KALS LATER TONIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PGW
AVIATION...HODANISH
AREA FORECAST DISCUSSION...CORRECTED
NWS PUEBLO CO
1022 AM MDT FRI SEP 13 2013
.UPDATE...
ISSUED AT 1012 AM MDT FRI SEP 13 2013
CANCELLED THE FLASH FLOOD WATCH EARLY AS THE RAIN HAS MOVED NORTH
OF EL PASO COUNTY AND ONLY SCATTERED LIGHT RAIN SHOWERS ARE
UPSTREAM OF THE REGION.
SATELLITE SHOWS ANOTHER DISTURBANCE OVER WESTERN NEW MEXICO MOVING
NORTHEAST...AND THIS DISTURBANCE WILL PASS OVER THE REGION BETWEEN
AROUND 4PM AND 8PM TODAY. HAVE SOME CONCERNS THAT THIS NEXT ROUND
OF STORMS COULD PRODUCE LOCALLY HEAVY RAINFALL. HRRR HAS BEEN TRENDING
SLIGHTLY STRONGER WITH THESE STORMS. HOWEVER...WINDS ALOFT HAVE
BECOME SOUTHWEST AT 15 TO 30 KNOTS. STORMS WHICH DEVELOP WILL WANT
TO MOVE TO THE NORTHEAST. AM NOT TOO CONCERNED ABOUT STORMS
TRAINING OVER ONE LOCATION. HOWEVER...STILL HAVE SOME CONCERNS
THAT STORMS COULD PRODUCE SPOTTY AREAS OF LOCALLY HEAVY RAIN. IF
ONE OF THESE SPOTTY STORMS STRIKES A BURN SCAR OR OTHER
SUSCEPTIBLE AREAS...FLASH FLOOD COULD OCCUR. HRRR KEEPS BAND OF
HEAVIER PRECIPITATION JUST NORTH OF THE PALMER DIVIDE WHERE ITWANTS
TO DEVELOP CONVECTION ALONG A BOUNDARY...LIKELY THE DENVER
CYCLONE.
WHAT TO DO ABOUT WATCHES. CURRENTLY...BELIEVE THREAT FOR HEAVY
RAIN NOT SUFFICIENTLY HIGH TO WARRANT EXTENDING THE FLASH FLOOD
WATCH. HOWEVER...THE SITUATION WILL BE MONITORED.
UPDATE ISSUED AT 512 AM MDT FRI SEP 13 2013
A STRONG SOUTHEAST WIND HAS DEVELOPED ALONG THE I-25 CORRIDOR IN
EL PASO AND PUEBLO COUNTIES...AND PRECIPITATION HAS INCREASED OVER
EL PASO COUNTY WITH UP TO AN INCH PER HOUR FALLING IN A VERY
NARROW BAND ACROSS COLORADO SPRINGS. LATEST FORECAST MODELS ARE
SHOWING THE POTENTIAL FOR SOME MODERATE TO HEAVY RAIN THROUGH THE
MORNING HOURS...SO HAVE ISSUED A FLASH FLOOD WATCH THRU 18Z FOR EL
PASO AND TELLER COUNTIES WHERE SOILS ARE ALREADY SATURATED AND
THERE WILL BE A THREAT TO THE WALDO CANYON AND BLACK FOREST BURN SCARS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM MDT FRI SEP 13 2013
RAIN COVERAGE OVR THE SERN PLAINS HAS DECREASED AND HAS BECOME
LIGHTER...WHILE PCPN OVR WESTERN PORTIONS HAS INCREASED TONIGHT WITH
GENERALLY LIGHT TO SOMETIMES MODERATE RAIN BEING REPORTED OVER THE
WEST FORK COMPLEX BURN SCAR. PCPN CONTINUES TO WORK ITS WAY
NORTHWARD FROM NM SO WL KEEP POPS IN THE LIKELY CATEGORY ACRS MOST
OF THE FORECAST AREA FOR THE MORNING HOURS. ALL INDICATIONS ARE
THAT PCPN THAT FALLS OVER EL PASO AND TELLER COUNTIES...WHERE THE
MOST SATURATED CONDITIONS ARE...WL MOSTLY BE ON THE LIGHT SIDE SO
CANCELED THE FF WATCH FOR THE I-25 CORRIDOR AT 3 AM.
THE UPR LOW WL CENTERED NR THE NV...UT AND ID BORDER REGION THRU
MUCH OF THE DAY. IT THEN BEGINS TO SHIFT EASTWARD OVERNIGHT AS IT
PHASES WITH AN UPR TROF WELL TO THE NORTH. THERE WL STILL BE A
PLUME OF MSTR OVR THE FORECAST AREA...ALONG WITH GOOD CHANCES FOR
PCPN...BUT ALL MODELS ARE SHOWING EXPECTED PCPN AMOUNTS BEING ON THE
LIGHTER SIDE TODAY. THAT DOES NOT MEAN THAT THERE WILL NOT BE SOME
LOCALLY HEAVY RAIN STILL WHICH COULD AGAIN CAUSE SOME FLASH
FLOODING.
TONIGHT PCPN CHANCES LOOK LIKE THEY WILL DECREASE...ESPECIALLY OVR
ERN CO. LATE TONIGHT A SHORTWAVE TROF IS EXPECTED TO APPROACH AND
THEN MOVE INTO SWRN CO AND COULD ENHANCE PCPN CHANCES OVR SRN
AREAS...SO WL GO WITH SOME HIGH SCT POPS IN THAT AREA. THE LOCAL
WRF MODEL SHOWS THE POTENTIAL FOR SOME HEAVY RAIN OVERNIGHT ON THE
WEST FORK COMPLEX BURN SCAR...WHILE THE NAM HAS LIGHTER AMOUNTS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM MDT FRI SEP 13 2013
PRIMARY LONGER TERM ISSUES INCLUDE POPS AND TEMPERATURES. LONGER
TERM COMPUTER SIMULATIONS AND FORECAST MODEL SOUNDINGS SUGGEST
THAT UNSETTLED AND GENERALLY COOL CONDITIONS SHOULD PREVAIL OVER
THE FORECAST DISTRICT INTO THIS WEEKEND BEFORE WARMER AND DRIER
CONDITIONS RETURN NEXT WEEK...ESPECIALLY FROM TUESDAY ONWARD.
AT THIS TIME...IT APPEARS THAT THE CWFA AREAL COVERAGE OF
PRECIPITATION ON SATURDAY WILL BE LESS THAN HAS BEEN NOTED PREVIOUS
FEW DAYS...ALTHOUGH LOCALLY HEAVY RAIN WILL STILL BE POSSIBLE AS
PRECIPITABLE WATER VALUES NEAR 1 INCH AT TIMES AND AREAS SUCH AS
THE RECENT BURN SCARS AND LOCATIONS THAT HAVE RECEIVED HEAVY
RAINFALL DURING THE PREVIOUS FEW DAYS WILL NEED TO BE MONITORED
FOR FLOODING/FLASH FLOODING CONCERNS.
THEN AN INCREASE IN COVERAGE OF PRECIPITATION IS ANTICIPATED ON
SUNDAY AS A NORTHERLY SURGE MOVES ACROSS EASTERN SECTIONS BY
SUNDAY MORNING INCREASING FORECAST PRECIPITABLE WATER VALUES TO
AROUND 1.10 INCHES OVER PORTIONS OF THE I-25 CORRIDOR. ONCE
AGAIN...LOCALIZED FLOODING/FLASH FLOODING ISSUES MAY
ARISE...ESPECIALLY OVER RECENT BURN SCAR AND PREVIOUS HEAVY RAIN
LOCATIONS. IN ADDITION...HIGHER MOUNTAIN LOCATIONS...GENERALLY
ABOVE 12000 FEET MAY EXPERIENCE SEVERAL INCHES OF SNOW FROM
EARLY SATURDAY MORNING INTO MONDAY MORNING.
DRIER AND WARMER CONDITIONS ARE THEN EXPECTED TO DEVELOP OVER THE
FORECAST DISTRICT...ESPECIALLY FROM TUESDAY INTO THURSDAY AS
FORECAST I-25 PRECIPITATION WATER VALUES DECREASE FROM 1.4 INCHES
AS OF THURSDAY NIGHT TO AROUND 0.50 INCHES BY NEXT WEDNESDAY. IN
ADDITION...FORECAST I-25 700 MB TEMPERATURES INCREASE FROM AN 8.8C
VALUE AT 00Z FRIDAY TO A 14.7C VALUE BY 00Z THURSDAY.
FINALLY...GENERALLY LOW-GRADE GRADIENT WINDS SHOULD CONTINUE
OVER THE FORECAST DISTRICT THROUGH NEXT THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 349 AM MDT FRI SEP 13 2013
SHOULD CONTINUE TO SEE A LOT OF LOW CLOUDS AT KCOS...KPUB AND KALS
THRU THE MORNING...WITH CIGS THEN INCREASING LATE IN THE MORNING
OR IN THE EARLY AFTERNOON HOURS. THE TERMINAL SITES WL ALSO HAVE A
GOOD CHANCE FOR SHOWERS TODAY AND MAYBE A FEW TSTMS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PGW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1013 AM MDT FRI SEP 13 2013
.UPDATE...
ISSUED AT 1012 AM MDT FRI SEP 13 2013
CANCELLED THE FLASH FLOOD WATCH EARLY AS THE RAIN HAS MOVED NORTH
OF EL PASO COUNTY AND ONLY SCATTERED LIGHT RAIN SHOWERS ARE
UPSTREAM OF THE REGION.
SATELLITE SHOWS ANOTHER DISTURBANCE OVER WESTERN NEW MEXICO MOVING
NORTHEAST...AND THIS DISTURBANCE WILL PASS OVER THE REGION BETWEEN
AROUND 4PM AND 8PM TODAY. HAVE SOME CONCERNS THAT THIS NEXT ROUND
OF STORMS COULD PRODUCE LOCALLY HEAVY RAINFALL. HRRR HAS TRENDING
SLIGHTLY STRONGER WITH THESE STORMS. HOWEVER...WINDS ALOFT HAVE
BECOME SOUTHWEST AT 15 TO 30 KNOTS. STORMS WHICH DEVELOP WILL WANT
TO MOVE TO THE NORTHEAST. AM NOT TOO CONCERNED ABOUT STORMS
TRAINING OVER ONE LOCATION. HOWEVER...STILL HAVE SOME CONCERNS
THAT STORMS COULD PRODUCE SPOTTER AREAS OF LOCALLY HEAVY RAIN. IF
ONE OF THESE SPOTTY STORMS STRIKES A BURN SCAR OR OTHER SUSCEPTIBLE
AREAS...FLASH FLOOD COULD OCCUR. HRRR KEEPS BAND OF HEAVIER
PRECIPITATION JUST NORTH OF THE PALMER DIVIDE WHERE IS WANTS TO
DEVELOP CONVECTION ALONG A BOUNDARY...LIKELY THE DENVER CYCLONE.
WHAT TO DO ABOUT WATCHES. CURRENTLY...BELIEVE THREAT FOR HEAVY
RAIN NOT SUFFICIENTLY HIGH TO WARRANT EXTENDING THE FLASH FLOOD
WATCH. HOWEVER...THE SITUATION WILL BE MONITORED.
UPDATE ISSUED AT 512 AM MDT FRI SEP 13 2013
A STRONG SOUTHEAST WIND HAS DEVELOPED ALONG THE I-25 CORRIDOR IN
EL PASO AND PUEBLO COUNTIES...AND PRECIPITATION HAS INCREASED OVER
EL PASO COUNTY WITH UP TO AN INCH PER HOUR FALLING IN A VERY
NARROW BAND ACROSS COLORADO SPRINGS. LATEST FORECAST MODELS ARE
SHOWING THE POTENTIAL FOR SOME MODERATE TO HEAVY RAIN THROUGH THE
MORNING HOURS...SO HAVE ISSUED A FLASH FLOOD WATCH THRU 18Z FOR EL
PASO AND TELLER COUNTIES WHERE SOILS ARE ALREADY SATURATED AND
THERE WILL BE A THREAT TO THE WALDO CANYON AND BLACK FOREST BURN SCARS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM MDT FRI SEP 13 2013
RAIN COVERAGE OVR THE SERN PLAINS HAS DECREASED AND HAS BECOME
LIGHTER...WHILE PCPN OVR WESTERN PORTIONS HAS INCREASED TONIGHT WITH
GENERALLY LIGHT TO SOMETIMES MODERATE RAIN BEING REPORTED OVER THE
WEST FORK COMPLEX BURN SCAR. PCPN CONTINUES TO WORK ITS WAY
NORTHWARD FROM NM SO WL KEEP POPS IN THE LIKELY CATEGORY ACRS MOST
OF THE FORECAST AREA FOR THE MORNING HOURS. ALL INDICATIONS ARE
THAT PCPN THAT FALLS OVER EL PASO AND TELLER COUNTIES...WHERE THE
MOST SATURATED CONDITIONS ARE...WL MOSTLY BE ON THE LIGHT SIDE SO
CANCELED THE FF WATCH FOR THE I-25 CORRIDOR AT 3 AM.
THE UPR LOW WL CENTERED NR THE NV...UT AND ID BORDER REGION THRU
MUCH OF THE DAY. IT THEN BEGINS TO SHIFT EASTWARD OVERNIGHT AS IT
PHASES WITH AN UPR TROF WELL TO THE NORTH. THERE WL STILL BE A
PLUME OF MSTR OVR THE FORECAST AREA...ALONG WITH GOOD CHANCES FOR
PCPN...BUT ALL MODELS ARE SHOWING EXPECTED PCPN AMOUNTS BEING ON THE
LIGHTER SIDE TODAY. THAT DOES NOT MEAN THAT THERE WILL NOT BE SOME
LOCALLY HEAVY RAIN STILL WHICH COULD AGAIN CAUSE SOME FLASH
FLOODING.
TONIGHT PCPN CHANCES LOOK LIKE THEY WILL DECREASE...ESPECIALLY OVR
ERN CO. LATE TONIGHT A SHORTWAVE TROF IS EXPECTED TO APPROACH AND
THEN MOVE INTO SWRN CO AND COULD ENHANCE PCPN CHANCES OVR SRN
AREAS...SO WL GO WITH SOME HIGH SCT POPS IN THAT AREA. THE LOCAL
WRF MODEL SHOWS THE POTENTIAL FOR SOME HEAVY RAIN OVERNIGHT ON THE
WEST FORK COMPLEX BURN SCAR...WHILE THE NAM HAS LIGHTER AMOUNTS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM MDT FRI SEP 13 2013
PRIMARY LONGER TERM ISSUES INCLUDE POPS AND TEMPERATURES. LONGER
TERM COMPUTER SIMULATIONS AND FORECAST MODEL SOUNDINGS SUGGEST
THAT UNSETTLED AND GENERALLY COOL CONDITIONS SHOULD PREVAIL OVER
THE FORECAST DISTRICT INTO THIS WEEKEND BEFORE WARMER AND DRIER
CONDITIONS RETURN NEXT WEEK...ESPECIALLY FROM TUESDAY ONWARD.
AT THIS TIME...IT APPEARS THAT THE CWFA AREAL COVERAGE OF
PRECIPITATION ON SATURDAY WILL BE LESS THAN HAS BEEN NOTED PREVIOUS
FEW DAYS...ALTHOUGH LOCALLY HEAVY RAIN WILL STILL BE POSSIBLE AS
PRECIPITABLE WATER VALUES NEAR 1 INCH AT TIMES AND AREAS SUCH AS
THE RECENT BURN SCARS AND LOCATIONS THAT HAVE RECEIVED HEAVY
RAINFALL DURING THE PREVIOUS FEW DAYS WILL NEED TO BE MONITORED
FOR FLOODING/FLASH FLOODING CONCERNS.
THEN AN INCREASE IN COVERAGE OF PRECIPITATION IS ANTICIPATED ON
SUNDAY AS A NORTHERLY SURGE MOVES ACROSS EASTERN SECTIONS BY
SUNDAY MORNING INCREASING FORECAST PRECIPITABLE WATER VALUES TO
AROUND 1.10 INCHES OVER PORTIONS OF THE I-25 CORRIDOR. ONCE
AGAIN...LOCALIZED FLOODING/FLASH FLOODING ISSUES MAY
ARISE...ESPECIALLY OVER RECENT BURN SCAR AND PREVIOUS HEAVY RAIN
LOCATIONS. IN ADDITION...HIGHER MOUNTAIN LOCATIONS...GENERALLY
ABOVE 12000 FEET MAY EXPERIENCE SEVERAL INCHES OF SNOW FROM
EARLY SATURDAY MORNING INTO MONDAY MORNING.
DRIER AND WARMER CONDITIONS ARE THEN EXPECTED TO DEVELOP OVER THE
FORECAST DISTRICT...ESPECIALLY FROM TUESDAY INTO THURSDAY AS
FORECAST I-25 PRECIPITATION WATER VALUES DECREASE FROM 1.4 INCHES
AS OF THURSDAY NIGHT TO AROUND 0.50 INCHES BY NEXT WEDNESDAY. IN
ADDITION...FORECAST I-25 700 MB TEMPERATURES INCREASE FROM AN 8.8C
VALUE AT 00Z FRIDAY TO A 14.7C VALUE BY 00Z THURSDAY.
FINALLY...GENERALLY LOW-GRADE GRADIENT WINDS SHOULD CONTINUE
OVER THE FORECAST DISTRICT THROUGH NEXT THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 349 AM MDT FRI SEP 13 2013
SHOULD CONTINUE TO SEE A LOT OF LOW CLOUDS AT KCOS...KPUB AND KALS
THRU THE MORNING...WITH CIGS THEN INCREASING LATE IN THE MORNING
OR IN THE EARLY AFTERNOON HOURS. THE TERMINAL SITES WL ALSO HAVE A
GOOD CHANCE FOR SHOWERS TODAY AND MAYBE A FEW TSTMS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PGW
AREA FORECAST DISCUSSION
NWS MIAMI FL
153 PM EDT FRI SEP 13 2013
.AVIATION...
A MUCH DRIER BOUNDARY LAYER COMBINED WITH A THIN VEIL OF SAHARAN
DUST IS INHIBITING SHRA/TSRA DEVELOPMENT THUS FAR THIS AFTERNOON.
LATEST SATELLITE TRENDS SHOW A VERY MEAGER CU FIELD WITH SEA
BREEZES AT BOTH COASTS BEGINNING TO DEVELOP. STILL BELIEVE ANY
CONVECTION THAT DOES DEVELOP SHOULD BE DRIVEN BY SEA BREEZE
INTERACTIONS AND SHOULD STAY GENERALLY INLAND OF THE TAF SITES.
KEPT VCTS AT ALL SITES THROUGH 00Z-01Z BUT STILL RATHER UNCERTAIN
IN THE OVERALL COVERAGE.
&&
.PREV DISCUSSION... /ISSUED 1005 AM EDT FRI SEP 13 2013/
UPDATE...
LITTLE IN ONGOING FORECAST THIS MORNING. 12Z RAOB ANALYSIS SHOWS
IMPRESSIVE LOW-MID-LVL DRY AIR / SAL THAT IS IMPACTING AT LEAST
SOUTHERN CWA TODAY. AS A RESULT...PWAT IS ONLY 1.50. WITH THIS
AMOUNT OF DRY AIR AND POSSIBLY DUST INTERFERE...CONVECTIVE
INITIATION POTENTIAL IS HIGHLY UNCERTAIN...PARTICULARLY WITH LACK
OF OVERALL DYNAMICS. STILL...SEA BREEZE CIRCULATIONS COULD BE
SUFFICIENT FOR DEVELOPMENT OF TSTMS MAINLY OVER NORTHERN INTERIOR.
SYNOPTIC MODELS REFLECT THIS OCCURRING...BUT HRRR DEPICTS ON
MODEST DEVELOPMENT. POPS RMN IN SCATTERED RANGE
INTERIOR...ISOLATED ALONG THE COASTS/WATERS. DOWNBURSTS ARE
FAVORED IN ANY STRONG CONVECTION...SO GUSTY WINDS CANT BE RULED
OUT. SLOW STORM MOTION COULD ALSO LEAD TO SIGNIFICANT RAINFALL
TOTALS...ALTHOUGH STORM CHANCES ARE BEST OVER NON-URBAN/FLOOD
PRONE AREAS.
PREV DISCUSSION... /ISSUED 355 AM EDT FRI SEP 13 2013/
DISCUSSION...
THE MAIN SYNOPTIC FEATURES ACROSS THE REGION INCLUDE WEAK HIGH
PRESSURE ACROSS SOUTH FLORIDA AND ADJACENT WATERS...A CUT-OFF UPPER
LEVEL LOW OFF THE GEORGIA COASTLINE AND A PLUME OF DEEP LAYER
MOISTURE EXTENDING FROM NEAR LAKE OKEECHOBEE THEN NORTHEASTWARD INTO
THE ADJACENT ATLANTIC WATERS. THESE FEATURES RESULTED IN CONVECTION
ACROSS NORTHEASTERN PALM BEACH COUNTY AND THE ADJACENT ATLANTIC
WATERS DURING THE EARLY MORNING HOURS WITH LINGERING SHOWERS AND
THUNDERSTORMS JUST TO THE EAST OF PALM BEACH COUNTY.
THERE IS SOME SAHARAN AIR LAYER DUST IN THE REGION WITH
RECENT GUIDANCE SUGGESTING THE MOST CONCENTRATED PART WILL LIKELY
REMAIN JUST SOUTH OF SOUTH FLORIDA ALTHOUGH SOME LESS CONCENTRATED
DUST AND DRIER AIR COULD IMPACT THE SOUTHERN HALF OR THIRD OF THE
PENINSULA TODAY. HARD TO SAY HOW MUCH IMPACT THIS MAY HAVE ON
AFTERNOON CONVECTION...ALTHOUGH LATEST GUIDANCE SUGGESTS THAT
MAYBE ONLY ISOLATED ACTIVITY AT BEST MAY BE EXPECTED ACROSS THE
SOUTHERN PORTIONS OF THE PENINSULA AND ADJACENT WATERS . BUT GIVEN
THE UNCERTAINTIES...THE CURRENT FORECAST INDICATES ONLY ISOLATED
SHOWERS/THUNDERSTORMS IN THE SOUTHERN MOST ZONE IN THE PENINSULA
OTHERWISE ISOLATED TO SCATTERED ACTIVITY FOR THE REMAINING EAST
AND WEST COAST METRO AREAS WITH SCATTERED ACTIVITY FORECAST
INTERIOR REGIONS.
TONIGHT INTO SATURDAY A COLD FRONT THAT IS CURRENTLY JUST NORTH OF
THE CAROLINAS IS FORECAST TO MOVE INTO NORTH FLORIDA ON SATURDAY
AND BECOME DIFFUSE THE REMAINDER OF THE WEEKEND. THE
AFOREMENTIONED CUT-OFF UPPER LEVEL LOW IS FORECAST TO QUICKLY LIFT
OFF TO THE NORTHEAST TODAY AND TONIGHT AND GET MERGED INTO A LARGE
AMPLITUDE UPPER LEVEL TROUGH FORECAST TO DIG INTO THE EASTERN SEA-
BOARD ON SATURDAY. FOR SATURDAY...WITH LINGERING MOISTURE ACROSS
THE REGION AND EASTERLY FLOW RETURNING MAINLY AFTERNOON ISOLATED
TO SCATTERED SHOWERS/THUNDERSTORMS ARE FORECAST WITH ISOLATED
ACTIVITY EXPECTED ACROSS THE EASTERN THIRD OF THE PENINSULA AND
SCATTERED ACROSS THE REMAINDER OF THE PENINSULA. BY SUNDAY THE
LARGE AMPLITUDE UPPER LEVEL TROUGH DIGS INTO THE SOUTHEAST U.S.
AND INTO THE REGION. THAT COUPLED WITH AN ADDITIONAL INFLUX OF
MOISTURE FROM THE ATLANTIC WATERS IS FORECAST TO RESULT IN
AFTERNOON SCATTERED SHOWERS AND THUNDERSTORMS. SIMILAR SYNOPTIC
CONDITIONS WILL PERSIST THROUGH THE EARLY PART OF THE WEEK. IN THE
LATER HALF OF THE WEEK ALTHOUGH MID TO UPPER LEVEL RIDGING BUILDS
INTO THE REGION...DEEP LAYERED MOISTURE IS FORECAST TO PREVAIL
ACROSS THE AREA WITH DIURNALLY DRIVEN SHOWERS/THUNDERSTORMS
FORECAST WEDNESDAY THROUGH FRIDAY.
MARINE...
WINDS ACROSS THE REGIONAL WATERS TODAY WILL BE LIGHT AND COULD AT
TIMES BECOME LIGHT AND VARIABLE. BY SATURDAY EASTERLY FLOW WILL
RETURN IN THE 6 TO 10 KNOT RANGE AND THEN BY MONDAY THROUGH MID-
WEEK MODERATE EASTERLY FLOW IN THE 10 TO 15 KNOT RANGE IS
FORECAST. TODAY THROUGH THE WEEKEND SEAS ACROSS THE GULF AND
ATLANTIC WATERS ARE EXPECTED TO BE 2 FEET OR LESS AND MONDAY
THROUGH NEXT WEEK SEAS FROM 2 TO 3 FEET ARE POSSIBLE ACROSS THE
ATLANTIC WATERS AND THE OFF SHORE GULF WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 89 78 89 / 20 20 10 40
FORT LAUDERDALE 79 91 80 91 / 10 20 10 40
MIAMI 77 91 79 90 / 10 20 10 40
NAPLES 75 92 76 93 / 10 20 10 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...23/SK
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS BILLINGS MT
250 PM MDT FRI SEP 13 2013
.SHORT TERM...VALID FOR SAT AND SUN...
SLOW MOVING UPPER LOW CONTINUES TO SPIN OVER THE NORTHERN GREAT
BASIN...WITH IMPRESSIVE SUBTROPICAL MOISTURE FETCH ALONG THE HIGH
PLAINS FROM NM TO MT. LATEST H3 ANALYSIS SHOWS A 50 KT JET
LIFTING INTO CENTRAL WY. AN AREA OF SHOWERS AT NOSE OF THIS JET
MAX HAS DEVELOPED FROM NEAR CPR TO THE BIG HORNS. OTHER THAN THE
ACTIVITY IN OUR FAR SOUTH...OUR AREA REMAINS DRY AS HIGH CLOUD HAS
SUPPRESSED CONVECTION TO THIS POINT...DESPITE COOLING TEMPS ALOFT
UNDERNEATH LOW TO OUR SW.
MODELS AGREE IN THEIR DEVELOPMENT OF A WEAK MID LEVEL LOW IN OUR
EAST TONIGHT...AND THIS IS CONSISTENT WITH EXPECTED GRADUAL
EASTWARD SHIFT IN THE JET ALOFT. COMBINATION OF SYNOPTIC SCALE
FORCING WITH PWATS ON THE ORDER OF AN INCH SHOULD RESULT IN GOOD
COVERAGE OF SHOWER ACTIVITY TONIGHT. RAP HAS TRENDED A BIT FURTHER
WEST WITH THIS LOW THAN THE GFS/NAM...AND THIS SEEMS REASONABLE
GIVEN CURRENT JET POSITION...SO HAVE COVERED EVERYWHERE FROM
BILLINGS EAST WITH A LIKELY POP TONIGHT. BEARTOOTH FOOTHILLS
SHOULD ALSO BE FAVORED PER DEEPENING UPSLOPE FLOW. INSTABILITY
SEEMS SUFFICIENT FOR ISOLD EMBEDDED TSTMS...BUT FOR THE MOST PART
BELIEVE WE WILL SEE LIGHT TO MODERATE SHOWERS...ESPECIALLY
CONSIDERING THE EFFECTS OF CLOUD COVER THIS AFTERNOON...SO DO NOT
SEE A SIGNIFICANT HEAVY RAIN THREAT TONIGHT.
MID LEVEL LOW WILL GET CAUGHT UP IN SAGGING CANADIAN JET AND
SHIFT EAST INTO THE DAKOTAS AROUND 12Z SATURDAY...SO EXPECT
STRONGER FORCING TO EXIT OUR AREA TOMORROW MORNING. SFC FRONTAL
PASSAGE FROM THE NORTH AND WEAK Q-VECTOR CONVERGENCE ON BACK SIDE
OF DEPARTING LOW WILL ALLOW FOR SHOWER DEVELOPMENT TOMORROW.
COOLER TEMPS ALOFT AND DIURNAL HEATING SHOULD ALLOW FOR AN
INCREASED CHANCE OF TSTMS ON SATURDAY...THOUGH BY AFTERNOON WE
WILL SEE AFFECTS OF DRIER POST FRONTAL CANADIAN AIR AS NORTH WINDS
INCREASE. THERE IS A WINDOW OF OPPORTUNITY...ALBEIT A FAIRLY
SHORT ONE...FOR DOWNPOURS AND LOCALLY HEAVY RAINFALL AMOUNTS WITH
TOMORROWS CONVECTION. HIGHEST POPS WILL BE IN OUR SOUTH AND EAST
PER UPSLOPE FLOW AND TIMING OF FROPA. EXPECT ACTIVITY TO BE
GREATLY REDUCED BY EVENING AS DRIER AND MORE STABLE SFC RIDGE
BUILDS FROM THE NORTH. HAVE SCALED BACK POPS QUITE A BIT SATURDAY
NIGHT.
AS FOR RAINFALL AMOUNTS...BELIEVE MOST AREAS WILL RECEIVE LESS
THAN AN INCH BUT CANNOT RULE OUT LOCAL AMOUNTS THAT HIGH
ESPECIALLY IN OUR SOUTH AND EAST. AS FOR BILLINGS...LOOKS LIKE ON
THE ORDER OF A QUARTER INCH WITH A HALF INCH POSSIBLE IF A HEAVY
SHOWER HITS US JUST RIGHT TOMORROW. TAKE NOTE...THIS SYSTEM IS
NOTHING LIKE WE HAD LAST WEEKEND...NOR WILL WE SEE THE INCREDIBLE
PCPN AMOUNTS THAT EASTERN COLORADO HAS EXPERIENCED OVER THE PAST
COUPLE DAYS. DIFFERENT SET UP ENTIRELY.
SUNDAY LOOKS DRY WITH INCREASED E-SE WINDS AS SFC RIDGE SHIFTS
EAST. COULD BE SOME SHOWERS/ISOLD TSTMS OVER OUR WEST/SOUTHERN
MTNS AS WEAK SHORTWAVE INTERACTS WITH MOISTURE LINGERING OVER THE
NORTHERN GREAT BASIN.
AS FOR TEMPERATURES...NEXT TWO DAYS WILL BE COOLER...BUT WITH
TEMPS NEAR TO SLIGHTLY ABOVE MID SEPTEMBER NORMALS. LOOK FOR
HIGHS MAINLY IN THE 70S SATURDAY AND SUNDAY.
JKL
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
MINIMAL CHANGES TO THE INHERITED LONG TERM FORECAST THIS
AFTERNOON...WITH MODELS IN CONTINUED GOOD AGREEMENT ON RELATIVELY
PROGRESSIVE WEATHER PATTERN. SOME TIMING DIFFERENCE REMAIN...BUT
DO NOT HAVE MUCH IMPACT ON THE OVERALL FORECAST. CHANGES CENTERED
AROUND INCREASING WINDS IN THE GAP FLOW AREAS AND WESTERN
FOOTHILLS AROUND LIVINGSTON AND BIG TIMBER... TO RESPOND TO
WEATHER SYSTEMS MOVING INTO AND OUT OF THE REGION.
STABLE CONDITIONS WILL CONTINUE INTO MONDAY...BUT CHANGE IS AGAIN
ON THE HORIZON. THE UPPER LEVEL RIDGING OVER THE AREA WILL BE
FLATTENED BY AN COLD FRONT THROUGH THE REGION MONDAY EVENING.
MONDAY WILL SEE WELL ABOVE AVERAGE TEMPERATURES AHEAD OF THE
FRONT...WITH SHOWERS AND THUNDERSTORMS DEVELOPING FROM WEST TO
EAST THROUGH THE EVENING AND NIGHT. SLIGHT CHANCE POPS WILL
CONTINUE THROUGH THE DAY TUESDAY...AS THE UPPER LEVEL TROD PASSES
EASTWARD. SO FAR MOISTURE AVAILABILITY APPEARS SOMEWHAT
LIMITED...COMPARED TO RECENT WEATHER...BUT CANNOT RULE OUT
DEVELOPMENT WITH STRENGTH OF THE SYSTEM. TEMPS WILL BE A BIT
COOLER TUESDAY...WITH EXPECTED INTERVENING CLOUD COVER AND SHOWER
ACTIVITY. THE FORECAST DRIES OUT SIGNIFICANTLY FOR THE REMAINDER
OF THE PERIOD FOLLOWING THIS WEATHER SYSTEM. TEMPS WILL FALL TO
AROUND SEASONAL AVERAGE FOR WEDNESDAY AND THURSDAY BEHIND THE
WEATHER SYSTEM...BUT JUMP BACK WELL ABOVE NORMAL FOR FRIDAY...AS
UPPER LEVEL RIDGING DEVELOPS ACROSS THE REGION. AAG
&&
.AVIATION...
SHOWERS ARE DEVELOPING ON THE BIGHORN MOUNTAINS...WITH INCREASING
CLOUDINESS OVER WESTERN MOUNTAINS. VFR CONDITIONS OVER CENTRAL AND
EASTERN ROUTES THIS EVENING...BUT WILL GIVE WAY TO LOCALIZED MVFR
OR LOWER CONDITIONS OVERNIGHT AS SHOWERS AND THUNDERSTORMS SPREAD
EASTWARD. A FEW STORMS MAY PRODUCE LOCAL LIFR CONDITIONS...IN
REDUCED VIS FROM HEAVY RAIN. INCREASING MOUNTAINS TOP OBSCURATION
CAN BE EXPECTED BY THIS EVENING AND OVERNIGHT. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
SAT SUN MON TUE WED THU FRI
-----------------------------------------------------------
BIL 062/076 052/078 055/085 057/081 054/073 049/073 049/083
65/T 20/B 01/U 23/T 32/W 11/U 00/U
LVM 054/073 047/078 050/085 049/078 045/072 042/072 041/079
44/T 22/T 22/T 23/T 32/W 21/B 02/T
HDN 058/076 050/079 051/086 054/083 052/076 048/076 050/083
66/T 21/B 11/U 13/T 32/W 11/U 00/U
MLS 061/077 050/076 053/084 058/083 056/074 050/074 052/083
66/T 10/U 01/U 12/T 33/W 11/B 00/U
4BQ 056/076 047/076 050/083 053/084 053/076 047/075 051/083
66/T 31/B 11/U 11/U 22/W 11/U 00/U
BHK 057/075 046/071 047/078 053/082 054/074 047/072 049/081
56/T 20/U 01/U 11/U 33/W 21/U 00/U
SHR 055/072 048/074 048/082 051/082 050/075 044/073 047/080
66/T 32/T 21/U 11/U 33/W 11/U 00/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
408 PM CDT FRI SEP 13 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 400 PM CDT FRI SEP 13 2013
ALOFT: UPR-LVL FLOW IS COMPLEX. A CUT-OFF LOW IS NEAR SLC AND WILL
REMAIN THERE THRU 00Z/SUN. A SMALL SUBTROPICAL HIGH WAS OVER TX WITH
ITS RIDGE EXTENDING N THRU THE PLAINS. A SHRTWV TROF WAS OVER WY AND
LIFTING N. THIS TROF WILL CONT INTO THE DAKOTAS TNGT-SAT AND
/COMBINED WITH A SIGNIFICANT TROF DROPPING THRU CNTRL CANADA/ WILL
FORCE THE RIDGE TO DEAMPLIFY AND SHIFT E.
SFC: HIGH PRES WAS OVER THE UPR MIDWEST...WHILE A WEAK SFC LOW WAS
OVER MT...ALONG A SFC TROF. SFC WINDS WILL GRADUALLY SHIFT FROM SE
TO S TNGT AND THEN TO SW TOMORROW. THRU 00Z/SUN...THE HIGH WILL
MIGRATE TO THE MID-ATLANTIC STATES...AND THE TROF WILL SETTLE INTO
NRN AND WRN NEB...AS THE NEXT CANADIAN COOL FRONT PRESSES INTO THE
NRN PLAINS.
REST OF THIS AFTN: CLOUDY S AND W OF THE TRI-CITIES WITH THE THREAT
OF PATCHY -RA W OF HWY 183 ENDING. FROM THE TRI-CITIES N AND E...
SLOWLY INCREASING CLOUDS.
RADAR TRENDS: THE HI-RES RAP AND THE 06Z WRF-NMM HAVE DONE A VERY
NICE JOB WITH THEIR SIMULATED REFLECTIVITY TODAY AND CONTS TO
SUPPORT CURRENT TRENDS. THIS BAND OF -RA WILL CONT LIFTING N WHILE
GRADUALLY DISSIPATING AS IT PROGRESSES INTO DRIER AIR. THE FCST AREA
COULD THEN BE MOSTLY DRY THE REST OF THE NGT.
THE 12Z NAM WAS WAY TOO DRY WITH ITS 12 HR QPF ENDING AT 00Z VS
REALITY.
THE WY SHRTWV TROF WILL TAKE THE BEST FORCING FOR LIFT/PCPN INTO THE
DAKOTAS TNGT. THAT IS ALSO WHERE THE NOSE OF THE LLJ WILL BE AIMED.
CAN/T COMPLETELY RULE OUT A SHWR OR TWO WITHIN GENTLE ISENTROPIC
LIFT.
WINDS BACKED TO THE S ON THE 12Z LBF SOUNDING AND MSTR IN THE
850-500 MB LAYER INCREASED SUBSTANTIALLY. THIS IS SUPPORTING THE
ON-GOING -RA OVER WRN/SRN PARTS OF THE FCST AREA...WHICH IS AT THE
LEADING EDGE OF THE GRADIENT OF HIGHER PW. BACKING WINDS AT ALL LVLS
WILL SHOVE THE MAX PW AXIS INTO THE FCST AREA TNGT.
WHILE MUCH OF THE FCST AREA HAS SEEN THE DECENT RAINFALL IN THE PAST
3 DAYS /MOSTLY ALONG AND S OF I-80/...THE SAD FACT IS MUCH OF THE
HIGH PW AIR MAY END UP BEING WASTED. PROSPECTS FOR RAIN ARE NIL TNGT
AND NOT LOOKING GOOD TOMORROW EXCEPT IN VERY ISOLATED POCKETS. WHILE
THE SFC TROF GETS CLOSE...AND THE TAIL END OF THE DAKOTA/S SHRTWV
TROF WILL BE OVER THE PANHANDLE ...THERE ISN/T MUCH FORCING ALOFT.
SO AM NOT EXPECTING MUCH DURING THE DAYLGT HRS OF SAT. WE CAN HOLD
OUT HOPE FOR SAT NGT.
TNGT: MAINLY CLOUDY. CAN/T ENTIRELY RULE OUT A SHWR OR TWO BUT MOST
LOCATIONS REMAIN DRY.
ONE CONCERN IS WHERE CLOUDS ARE CURRENTLY THIN FROM THE TRI-CITIES N
AND E. DWPTS ARE LOW THERE AND TEMPS WILL DROP OFF RATHER SHARPLY
THIS EVNG. FOR NOW ANTICIPATED THAT CLOUDS WILL INCREASE IN TIME TO
ARREST DROP-OFF WITH LOWS FAIRLY UNIFORM OVER THE ENTIRE FCST AREA
/MID-UPR 50S/. LOWS N AND E OF THE TRI-CITIES ARE ONLY AVERAGE
CONFIDENCE.
SAT: M/CLOUDY. TEMPS ARE LOW CONFIDENCE DUE TO CLOUD COVER
UNCERTAINTY. HIGHS WERE LOWERED 1-2F. A HIGH-PW AIR MASS WILL BE IN
PLACE /2 STANDARD DEVIATIONS ABOVE NORMAL/. EXPECT SOME AREAS MAY
THIN ENOUGH FOR MARGINAL DESTABILIZATION AND ISOLD-SCT TSTM
DEVELOPMENT...MUCH LIKE WHAT IS OCCURRING OVER SERN CO AND THE TX
PANHANDLE ATTM.
MLCAPE WILL BE LESS THAN 1000 J/KG. INDIVIDUAL CELL MVMT WILL BE NE
AROUND 25 KTS. DEEP LAYER SHEAR WILL BE 15-20 KTS. NO SVR WX IS
EXPECTED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 400 PM CDT FRI SEP 13 2013
SATURDAY NIGHT...AN UPPER LEVEL TROUGH WITH AN ACCOMPANYING COLD
FRONT WILL SWING THROUGH THE FORECAST AREA BRINGING WITH IT OUR BEST
CHANCE OF SHOWERS AND THUNDERSTORMS. INSTABILITY WILL BE WEAK AND
THUS AM NOT EXPECTING ANY KIND OF SEVERE WEATHER...BUT RATHER
PERHAPS JUST A GENERAL LINE OR SEVERAL LINES OF SHOWERS AND
THUNDERSTORMS THAT WILL TRACK ACROSS THE AREA.
SUNDAY AND MONDAY...THE COOL FRONT WILL TRACK ACROSS KANSAS ON
SUNDAY AND WATCH OUT OVER OKLAHOMA BY SUNDAY NIGHT/MONDAY MORNING.
RAIN CHANCES WILL DECREASE ACROSS OUR FORECAST AREA WITH BETTER
CHANCES OF SHOWERS AND THUNDERSTORMS FURTHER SOUTH FOLLOWING THE
FRONT. HAVE DECREASED RAIN CHANCES ACROSS OR FORECAST AREA DURING
THIS PERIOD DUE TO THE QUICK PROGRESS OF THE FRONT AND AM NOW EVEN
GOING DRY FOR MONDAY ACROSS NEBRASKA ZONES WITH JUST A SLIGHT CHANCE
OF SHOWERS ACROSS NORTHERN KANSAS. TEMPERATURES WILL BE COOLER
BEHIND THE COLD FRONT RANGING FROM AROUND 70 NORTH TO THE MID 70S
OVER NORTHERN KANSAS.
MONDAY NIGHT/TUESDAY...A MINOR SHORTWAVE WILL TRACK NORTHEAST ACROSS
OUR FORECAST AREA AND A WEAK WARM FRONT WILL LIFT BACK THROUGH.
THIS WILL RESULT IN GENERALLY LOW END RAIN CHANCES. TEMPERATURES
WILL START TO WARM UP AND MAY ONCE AGAIN BE BACK TO AROUND 80 BY
TUESDAY AFTERNOON.
WEDNESDAY THROUGH FRIDAY...AN UPPER RIDGE WILL TRY TO BUILD ACROSS
THE PLAINS...BUT WILL NOT BE OVERLY STRONG SO NO REPEAT OF THE 90
DEGREE HEAT. EXPECT MOST AREAS WILL BE DRY WITH ABOVE NORMAL
TEMPERATURES IN THE 80S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1246 PM CDT FRI SEP 13 2013
REST OF THIS AFTN: VFR WITH BKN 25K FT CIRRUS AND SCT 8-15K MID-
LVL CLOUDS. SSE WINDS BELOW 10 KTS.
TNGT: VFR WITH MID-LVL CIGS CONTINUING TO CASCADE DOWN TO AROUND
7K FT. SSE WINDS BELOW 10 KTS. COULD BE A TOUCH OF -RA AFTER 09Z
BUT CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN THE TAF.
SAT THRU 18Z: VFR FOR NOW...BUT THERE IS POTENTIAL FOR CIGS TO
CONTINUE DEGRADING TO MVFR. SOME -RA IS ALSO POSSIBLE. WINDS WILL
SHIFT TO S AND GUST UP TO 19 KTS AFTER 16Z.
CIG CONFIDENCE: MEDIUM
VSBY CONFIDENCE: HIGH
WIND CONFIDENCE: HIGH
WX CONFIDENCE: LOW
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1246 PM CDT FRI SEP 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT FRI SEP 13 2013
TODAY AND TONIGHT...THE MODELS APPEAR TO BE TOO FAST AND AGGRESSIVE
LIFTING THE AREA OF RAIN ACROSS NWRN KS/NERN COLO THROUGH THE FCST
AREA TODAY AND TONIGHT. SO THE FORECAST SLOWS THIS BY 3 HOURS WHICH
MAY NOT BE ENOUGH. OTHERWISE...THE CLOUD SHIELD ACROSS SWRN NEB
SHOULD SPREAD SLOWLY NORTH TODAY AND TONIGHT. THE FORECAST ATTEMPTS
TO MARK UP TEMPS FOR WARMER HIGHS AS THE CLOUDS AND RAIN WILL LIKELY
BE DELAYED BY SEVERAL HOURS AND MAY NOT REACH INTERSTATE 80 UNTIL
LATE THIS AFTERNOON.
MODEL BLENDED QPF PRODUCED AROUND 1/3 OF AN INCH ACROSS SWRN NEB TO
0.05 INCHES ACROSS ERN ZONES. THE RAP MODEL LIFTS THE RAIN NORTH
VERY QUICKLY AND DRIES IT OUT AT THE SAME TIME WHICH IS LIKELY A
RESULT OF DRY AIR AT THE LOWER LEVELS. THE HRRR MODEL IS WAY TOO
FAST AND A PLUME OF ALL MODEL SOLNS FOR NORTH PLATTE SHOW A VERY
WIDE SPREAD OF QPF TOTALS FROM 1/3 OF AN INCH TO A TRACE. THUS THE
RAIN CHANCES ACROSS MUCH THE FCST AREA EXCEPTING FAR SWRN NEB ARE
UNCERTAIN.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 340 AM CDT FRI SEP 13 2013
FORECAST CONFIDENCE REMAINS AVERAGE THROUGH THE WEEKEND WITH
DECENT CONSISTENCY DISPLAYED FROM THE LONG RANGE SOLUTIONS. FOR
SATURDAY...RAIN CHANCES DO NOT APPEAR TO BE AS WIDESPREAD AS THE
BULK OF THE QG FORCING AND ASSOCIATED WEAKENING UPPER LEVEL LOW IS
DIRECTED TO THE NORTH AND WEST OF THE CWA...BUT INCREASING
ATMOSPHERIC INSTABILITY WITH SUFFICIENT MOISTURE WOULD ALLOW FOR
AT LEAST A CONTINUED MENTION OF STORMS THROUGH THE DAY. BETTER
CHANCES HOWEVER APPEAR TO ARRIVE LATE SATURDAY INTO EARLY SUNDAY
AS A WEAK DISTURBANCE WORKS ON A PASSING FRONTAL BOUNDARY...SHOWER
AND THUNDERSTORM CHANCES WILL REMAIN HIGHEST ALONG OUR SOUTHERN
AND EASTERN BORDERS AS THE FRONT SETTLES ACROSS KANSAS. WITH HIGH
PRESSURE BUILDING SOUTH ACROSS THE NORTHERN HIGH PLAINS AND INTO
THE UPPER MISSISSIPPI RIVER VALLEY ON SUNDAY...DRIER CONDITIONS
ARE ANTICIPATED FOR MUCH OF THE REGION. THERE WILL BE A SHARP
DIVIDING LINE HOWEVER AS A CONTINUED TAP OF MOIST MONSOONAL AIR
DRIVES NORTH THROUGH THE SOUTHERN PLAINS. A RECENT TREND OF THE
LONGER RANGE SOLUTIONS IS TO SETTLE THE FRONT FURTHER SOUTH ACROSS
SOUTHERN/CENTRAL KANSAS WITH DRIER AIR /VOID OF PRECIPITATION/
ACROSS MOST IF NOT ALL LOCATIONS ACROSS THE CWA. DID NOT WANT TO
ENTIRELY PULL POPS YET ON SUNDAY AND INTO MONDAY...THUS WILL LOWER
TO A SLIGHT CHANCE MENTION FOR MOST PLACES...BUT FEEL WE COULD GO
LOWER YET. WITH THE DRIER AIR WORKING SOUTH...CONDITIONS WILL BE
PLEASANTLY COOL ON SUNDAY...WITH HIGHS TOPPING OUT IN THE UPPER
60S TO LOW 70S. LOOKING AHEAD TO EARLY NEXT WEEK...THE MODEL
CONSENSUS DEVELOPS A BROAD RIDGE ACROSS THE CENTRAL CONUS WITH
PERIODIC SHORTWAVES SUPPRESSING ITS STRENGTH. A GENERAL WARMING
TREND IS THEN SHOWN...WITH HIGHS RETURNING BACK INTO THE 80S AS
EARLY AS TUESDAY...AND LOWS FALLING INTO THE UPPER 50S FOR MOST
PLACES. PERIODIC STORM CHANCES ARE IN STORE FOR NEXT WEEK...MAINLY
ACROSS EASTERN PORTIONS OF THE CWA AS A FRONT STALLS AND PERIODIC
WAVES PASS THROUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1246 PM CDT FRI SEP 13 2013
BATTLE BETWEEN MOIST AIR/SHOWERS LIFTING NORTHEAST TOWARDS A DRY
HIGH PRESSURE. EXPECTING SOME SHOWERS TO CONTINUE ACROSS SW
NEB...LIFTING TOWARDS THE KLBF TERMINAL...HOWEVER THINK KVTN WILL
REMAIN DRY. IN ADDITION TO THE CHANCE FOR RAIN...LOWERING CIGS ARE
EXPECTED. MVFR CIGS ARE LIKELY WITHIN SHOWERS FOR KLBF. SOUTHWEST
NEBRASKA WILL SEE LOWER CIGS...LESS THAN 1K FT...AS SE WINDS BRING
UPSLOPE FLOW AND AID IN LOWERING THE CIG. BY TOMORROW MORNING
CONDITIONS IMPROVE WITH CIGS RISING AND THE CHANCE FOR RAIN
DIMINISHING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...MASEK
AREA FORECAST DISCUSSION
NWS ELKO NV
1205 PM PDT FRI SEP 13 2013
.SYNOPSIS...ABUNDANT MOISTURE AND INSTABILITY FROM A SLOW MOVING
STORM SYSTEM WILL BRING SCATTERED THUNDERSTORMS AND WIDESPREAD
SHOWERS TO NORTHERN NEVADA. SOME AREAS MAY SEE HEAVY RAIN...WITH
POSSIBLE FLOODING CONCERNS. LOOK FOR SCATTERED THUNDERSTORMS
AGAIN ACROSS EASTERN NEVADA ON SATURDAY. DRY WEATHER RETURNS TO
NEVADA SUNDAY THROUGH NEXT WEEK...WITH BREEZY CONDITIONS MONDAY
INTO TUESDAY.
&&
.UPDATE...UPDATED THE FLASH FLOOD WATCH, REFRESHING THE WORDING,
AND EXTENDING IT TO INCLUDE ELKO AND WHITE PINE COUNTIES INTO
SATURDAY EVENING. THUNDERSTORM COVERAGE WILL BE DECREASED ON
SATURDAY COMPARED TO RECENTLY, BUT WITH A MOIST AIR MASS LINGERING
AND IT BEING THE WEEKEND, FELT IT BEST TO KEEP THE WATCH GOING ONE
MORE DAY.
NEXT ROUND OF THUNDERSTORMS DEVELOPING ON SCHEDULE EARLY THIS
AFTERNOON. MOST STORMS WILL SHOW A NET SOUTH/SE MOTION WHICH MAY
REDUCE THE FLOODING THREAT, AT LEAST COMPARED TO YESTERDAY. TURNER
&&
.PREV DISCUSSION... /ISSUED AT 325 AM /
SYNOPSIS...ABUNDANT MOISTURE AND INSTABILITY FROM A SLOW MOVING
STORM SYSTEM WILL BRING SCATTERED THUNDERSTORMS AND WIDESPREAD
SHOWERS TO NORTHERN NEVADA. SOME AREAS MAY SEE HEAVY RAIN...WITH
POSSIBLE FLOODING CONCERNS. LOOK FOR SCATTERED THUNDERSTORMS
AGAIN ACROSS EASTERN NEVADA ON SATURDAY. DRY WEATHER RETURNS TO
NEVADA SUNDAY THROUGH NEXT WEEK...WITH BREEZY CONDITIONS MONDAY
INTO TUESDAY.
SHORT TERM...TODAY THROUGH SATURDAY. A LARGE COUNTERCLOCKWISE
CIRCULATION CAN BE SEEN OVER NORTHEAST NEVADA THIS MORNING. THIS
IS ASSOCIATED WITH AN UPPER LEVEL STORM SYSTEM THAT HAS BEEN SLOW
TO MOVE OUT OF THE AREA. IT HAS BEEN RESPONSIBLE FOR THE RAINFALL
THE AREA HAS RECEIVED IN THE LAST TWO DAYS. MODELS SHOW IT MOVING
SLOWLY EAST DURING THE DAY TODAY. BUT WE WILL STILL BE UNDER ITS
EFFECTS.
RIGHT NOW...RADAR IS SHOWING SOME WEAK RETURNS WITH LIGHT SHOWERS
OVER PORTIONS OF HUMBOLDT COUNTY...WITH ENHANCED ACTIVITY SEEN IN
SOUTHWEST IDAHO. 3KM HRRR IS SHOWING AN INCREASE IN SHOWER ACTIVITY
BEGINNING IN THE LATE MORNING HOURS OVER ELKO AND WHITE PINE
COUNTIES.
MODELS CONTINUE TO SHOW A FAVORABLE ENVIRONMENT FOR SHOWERS AND
THUNDERSTORMS TO DEVELOP TODAY. CAPE VALUES ARE FORECAST TO BE
AROUND 200-600 J/KG...WITH THE HIGHEST VALUES SEEN IN WHITE PINE
AND ELKO COUNTIES. STORM MOTIONS WILL ONCE AGAIN BE QUITE SLOW AT
ABOUT 5 TO 10 KNOTS IN THE 700-500 MB LAYER. K-VALUES DURING THE
FRIDAY TIME FRAME RANGE FROM 35-40C...WITH CORFIDI VECTOR
MAGNITUDES OF 0-5 KNOTS. BASED ON THE GUIDANCE...WILL CONTINUE THE
FLASH FLOOD WATCH WITH NO CHANGES. POP GRIDS ALSO LOOKED GOOD AND
ONLY MADE MINOR ADJUSTMENTS.
FOR TONIGHT...UPPER LEVEL SYSTEM WILL SLOWLY WORK ITS WAY EAST AND
SET UP SHOP SOMEWHERE AROUND NORTHERN UTAH. THE REGION WILL STILL
BE UNDER A MOIST AND UNSTABLE ATMOSPHERE SO HAVE CONTINUED
ISOLATED THUNDERSTORMS WITH SCATTERED TO NUMEROUS RAIN SHOWERS.
BY SATURDAY...THE FORECAST AREA WILL BE UNDER A NORTHWEST FLOW
ALOFT...WITH SOME MINOR DRYING TAKING PLACE IN THE WESTERN ZONES.
BUT IT SHOULD BE MOIST AND UNSTABLE ENOUGH IN THE
EAST...ELKO...EUREKA...WHITE PINE...AND NORTHEAST NYE
COUNTIES...FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS.
AFTERNOON HIGHS WILL RUN AT OR JUST ABOVE NORMAL.
LONG TERM...SATURDAY NIGHT THROUGH NEXT THURSDAY. MODELS IN GOOD
AGREEMENT ONLY EXCEPTION IS THE GFS IS A BIT COOLER AND STRONGER
WITH THE TROUGH MOVING ACROSS NORTHERN NEVADA ON TUESDAY AND
WEDNESDAY. ISOLATED THUNDERSTORMS EXPECTED ACROSS NORTHEASTERN
NEVADA ON SUNDAY AFTERNOON AND EVENING AS A UPPER LEVEL TROUGH ALONG
WITH INSTABILITY AND RESIDUAL MOISTURE REMAIN OVER THIS AREA. MUCH
DRIER CONDITIONS THROUGH THE REST OF THE PERIOD...ONLY SIGNIFICANT
WEATHER WILL BE COOLING TEMPERATURES AND BREEZY WINDS EARLY NEXT WEEK AS
A COLD FRONT MOVES THROUGH THE AREA LATE MONDAY INTO TUESDAY MORNING
AND THEN ANOTHER WARM UP BY THURSDAY AHEAD OF A STRONG UPPER LEVEL
SYSTEM. TEMPERATURES WILL BE ABOVE NORMAL SUNDAY THROUGH TUESDAY
BEFORE COOLING TO NEAR NORMAL READINGS BY THE MIDDLE OF NEXT WEEK.
AVIATION...MAINLY VFR CONDITIONS HOWEVER KELY MAY SEE SOME
INTERMITTENT MVFR CIGS AND OTHER TERMINALS MAY TEMPORARILY SEE MVFR
VISIBILITIES DUE TO HEAVIER RAIN SHOWERS. THUNDERSTORMS POSSIBLE AT
ALL TERMINALS WITH 20 PERCENT CHANCE AT KTPH AND KWMC AND 30 TO 40
PERCENT CHANCE AT KELY AND KEKO.
FIRE WEATHER...VERY MOIST AIR MASS OVER THE AREA...COMBINED WITH
INSTABILITY...WILL PROVIDE THE IMPETUS FOR SHOWERS AND
THUNDERSTORMS ACROSS MUCH OF NORTHERN NEVADA. SOME DRYING POSSIBLE
TOMORROW IN THE WESTERN ZONES...BUT SHOULD SEE SCATTERED SHOWERS
AND THUNDERSTORMS IN THE EASTERN FIRE ZONES OF 454 AND 457...AND
WELL AS ALL OF ZONE 455 AND 469 AND 470. EVEN DRIER STILL ON
SUNDAY WITH ONLY ISOLATED COVERAGE IN 469 AND 470. A DRY COLD
FRONTAL PASSAGE EXPECTED MONDAY INTO TUESDAY WHICH WILL BRING
BREEZY CONDITIONS TO NORTHERN NEVADA.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH SATURDAY EVENING FOR NORTHERN ELKO
COUNTY...RUBY MOUNTAINS/EAST HUMBOLDT RANGE...SOUTH CENTRAL ELKO
COUNTY...SOUTHEASTERN ELKO COUNTY...SOUTHWESTERN ELKO COUNTY...
WHITE PINE COUNTY.
FLASH FLOOD WATCH UNTIL MIDNIGHT PDT TONIGHT FOR NORTHEASTERN
NYE COUNTY...NORTHERN LANDER COUNTY AND NORTHERN EUREKA COUNTY...
SOUTHERN LANDER COUNTY AND SOUTHERN EUREKA COUNTY.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
235 PM EDT FRI SEP 13 2013
.SYNOPSIS...
MOSTLY CLOUDY SKIES WILL PERSIST TONIGHT...WITH SCATTERED LIGHT SHOWERS
AND PATCHY DRIZZLE MAINLY DOWNWIND OF LAKE ONTARIO AND THE FINGER
LAKES. SKIES WILL BECOME PARTLY TO MOSTLY SUNNY ON SATURDAY AS
HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES. FAIR AND WARMER
WEATHER IS EXPECTED ON SUNDAY AS THIS HIGH MOVES OFF THE EAST
COAST. A COLD FRONT WILL PASS THE REGION ON SUNDAY NIGHT AND
MONDAY WITH A CHANCE OF SHOWERS.
&&
.NEAR TERM /THROUGH SATURDAY/...
BATCH OF HEAVIER SHRA ACRS SE ZONES WILL MOVG OUT OF THE AREA BY
MID/LATE AFTN AS UPR LOW CONTINUES IT`S SLOW NEWD TREK. ANOTHER
VORT AXIS ACRS MI WILL MOV EWD ACRS THE FCST AREA LATER TNGT.
PLENTY OF LOW LVL MSTR PERSISTS TNGT...AND CONDITIONAL LAKE
INSTABILITY DVLPS. LOW LVL FLOW WILL MEANDER ARND 340 DEG...WITH
LAKE ONTARIO AND THE FINGER LAKES LIKELY AIDING DVLPMNT OF --SHRA
OR PATCHY -DZ. BEST BEST FOR LGT PCPN APPEARS TO BE ALONG AND W OF
THE I-81 CORRIFOR. GIVEN EXPECTATION OF CLDS TNGT XPCT MOST LOWS
TO BE IN THE M40S.
NAM/GFS STRONGLY SUGGEST THAT WE`LL BE CLEARING OUT EARLY TMRW
MRNG...BUT GEM HOLDS ONTO THE CLDS MUCH LONGER (WELL INTO THE
AFTN...SPCLY ERN ZONES). LATEST RUC PROFILES ALSO SUGGEST OVC
SKIES AT 11Z ACRS CNTRL NY. FOR THIS REASON WE WERE LEARLY OF
CLEARING OUT THE SKIES AS QUICK AS MOS WOULD SUGGEST. CRNT FCST
MAY STILL BE TOO QUICK IN CLEARING THINGS OUT BUT TRENDED TWDS
SLOWER IMPPRVMNT TMRW. MAXES TMRW ON THE COOL SIDE...GNRLY 60-65.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
SFC HI PRES RDG CRESTS OVER THE FCST AREA ON SAT NGT. POTNL FOR
PATCHY FROST SPCLY IN THE CATSKILLS AND COLDER SRN TIER VLYS. FOR
NOW WILL JUST MENTION POTNL IN THE HWO. OTRW SUNDAY LOOKS LIKE A
NICE DAY WITH MAXES MODERATING INTO THE U60S AND LOWER 70S. WE`LL
PRBLY SEE A BKN CI DEWK MOVG INTO THE REGION DURING THE AFTN
AHEAD OF THE NXT S/WV. THIS WAVE WILL PUSH A CDFNT THRU ON SUNDAY
NGT...WITH POTNL FOR 2NDRY REINFORCING SHOT ON MONDAY. CHC/LIKELY
POPS FOR SUNDAY NGT...DCRSNG TO CHC POPS ON MONDAY. BEST CHC FOR
-SHRA ON MON APPEARS TO BE IN THE MRNG...WITH DRIER AIR AND
IMPRVNG SKY COVER ACRS NRN ZONES ON MON AFTN.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
AT THE BEGINNING OF THE PERIOD UPPER LEVEL TROF WILL MOVE EAST OF
AREA AS A FLAT RIDGE BUILDS ACROSS THE NORTHEAST. LATE IN THE
PERIOD AN UPPER LEVEL TROF DROPS INTO THE GREAT LAKES.
WILL CONTINUE WITH A DRY FORECAST MONDAY NIGHT THROUGH WEDNESDAY,
AS SFC HIGH PRES BUILDS SOUTH ACROSS THE AREA ON TUESDAY THEN
MOVES OFF THE NEW JERSEY COAST BY WEDNESDAY. TEMPS WILL WARM
DURING THE PERIOD AS FLOW SHIFTS FROM NORTHWEST TO SOUTHWEST.
WEDNESDAY NIGHT THROUGH FRIDAY, WILL CARRY SLIGHT CHC/CHC POPS AS
NEXT UPPER LEVEL TROF APPROACHES THE REGION AND ASSOCIATED SFC LOW
TRACKS FROM THE UPPER GREAT LAKES EAST ACROSS NEARBY SOUTHERN
CANADA. MEDIUM RANGE MODELS SHOW SIGNIFICANT TIMING DIFFERENCES
WITH THIS FEATURE, WITH THE ECMWF FASTER THAN THE GFS. AREA MAY
BE IMPACTED BY WARM FRONTAL SHOWERS THURSDAY/THURSDAY NIGHT
FOLLOWED BY SFC COLD FRONT ON FRIDAY. TEMPS WILL RANGE SLIGHTLY
ABOVE NORMAL.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
UPPER LEVEL TROF WILL REMAIN OVER THE AREA THROUGH THIS TAF PERIOD
WITH A COOL NORTHWEST FLOW. THROUGH MID MORNING SATURDAY
WIDESPREAD MVFR/LOW MVFR CIGS ARE EXPECTED WITH IFR CIGS LIKELY AT
KBGM/KITH LATE TONIGHT. SCATTERED LIGHT LAKE EFFECT RAIN SHOWERS
ARE ALSO EXPECTED OVERNIGHT MAINLY IN THE FINGER LAKES REGION.
THIS WAS INCLUDED IN JUST THE KITH TERMINAL. SATURDAY, LOW LEVEL
DRYING WILL LEAD TO VFR CONDITIONS BY MIDDAY.
NORTHWEST WINDS AROUND 10 KNOTS WITH GUSTS 15-20 KNOTS THIS AFTERNOON.
OUTLOOK...
SUN...VFR...BUT MAYBE SOME EARLY MORNING FOG/IFR AT KELM.
SUN NGT/MON...RESTRICTIONS IN SCATTERED SHOWERS.
MON NGT THROUGH WED...VFR UNDER HIGH PRESSURE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
LONG TERM...RRM
AVIATION...RRM