Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/12/13
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1010 PM MST MON SEP 9 2013
...ELEVATED PRECIPITATION CHANCES WITH HEAVY RAINFALL POTENTIAL
CONTINUES TONIGHT AND TUESDAY...
.SYNOPSIS...
AN UPPER LOW WILL CONTINUE TO PROVIDE WEATHER DISTURBANCES TO
INTERACT WITH MONSOON MOISTURE...SUPPORTING A CONTINUED WET AND
ACTIVE STORM PATTERN WITH THE THREAT FOR HEAVY RAINFALL. CLOUDY
SKIES IN COMBINATION WITH SHOWERS AND THUNDERSTORMS WILL KEEP
DAYTIME HIGHS WELL BELOW NORMAL THROUGH MIDWEEK. MOISTURE WILL BE
SLOW TO CLEAR OUT OF THE AREA...KEEPING AT LEAST SLIGHT CHANCES IN
THE FORECAST THROUGH THE END OF THE WORK WEEK. TEMPERATURES WILL
ALSO BEGIN A SLOW CLIMB BACK TOWARDS MORE NORMAL READINGS.
&&
.DISCUSSION...
STORM ACTIVITY APPEARS TO BE WINDING DOWN FOR THE EVENING OVER OUR
FORECAST AREA THOUGH THERE ARE LINGERING SHOWERS AND ISOLATED
THUNDERSTORMS OVER SOUTHWEST ARIZONA AND FAR SOUTHEAST CALIFORNIA AS
OF THIS WRITING. THIS IS WHERE THE MAJORITY OF THE ACTION WAS FROM
ROUGHLY MID AFTERNOON ONWARD. TODAY AND YESTERDAY VORT MAXES FROM
MEXICO HAVE BEEN PULLED NORTHWARD INTO ARIZONA LEADING TO ANOMALOUS
EARLY DAY PRECIPITATION OVER SOUTH-CENTRAL ARIZONA. SATELLITE
IMAGERY SHOWS MAIN UPPER LOW REMAINS CENTERED OVER SOUTHEAST
CALIFORNIA. THIS LOW AND AND SUFFICIENT SURFACE HEATING HELPED MAKE
THINGS ACTIVE OVER SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA. THE
LATEST RUC SUGGESTS ANOTHER VORT MAX FROM NORTHERN MEXICO WILL MOVE
INTO SOUTH-CENTRAL ARIZONA OVERNIGHT BUT IT ONLY GENERATES PRECIP
OVER OUR HIGHER TERRAIN ZONE EAST OF THE PHOENIX AREA. IT ALSO SHOWS
A VORT LOBE ROTATING AROUND THE MAIN LOW CENTER AFFECTING SOUTHWEST
ARIZONA. THE GFS AND NAM HAVE VARIATIONS ON THAT SAME THEME WITH THE
NAM SHOWING WEAKER VORTICITY FEATURES. THE LATEST HRRR MODEL
SUPPORTS THE RUC SCENARIO BUT ALSO HAS SPOTTY PRECIP ELSEWHERE
THROUGH THE MORNING HOURS INCLUDING THE PHOENIX AREA. HOWEVER...IT
HAS BEEN OVERDOING THE PRECIP IN WESTERN PORTIONS OF OUR FORECAST.
GIVEN THE GENERAL AGREEMENT ON FURTHER PRECIP POTENTIAL...WILL HOLD
ON TO THE HIGH POPS. OF NOTE...THE PRECIPITABLE WATER HAS BEEN
COMING DOWN PER GPS DATA AND BLENDED SATELLITE IMAGERY...THOUGH THE
LATTER IS A BIT UNDERDONE IN SOME SPOTS. THIS MAY KEEP SUBSEQUENT
DISTURBANCES FROM BEING QUITE AS PRODIGIOUS IN RAIN PRODUCTION.
REGARDING KIWA RADAR DATA OUTAGE...TELEPHONE COMPANY HAS BEEN
WORKING ON REPAIRING DATA CONNECTION AND WE MAY JUST NOW BE GETTING
DATA RESTORED.
&&
.PREVIOUS DISCUSSION ISSUED 304 PM...
INGREDIENTS CAME TOGETHER TODAY AT THE RIGHT TIME TO SUPPORT EARLY
MORNING SHOWER ACTIVITY THAT DEVELOPED INTO LARGER AND HEAVIER
THUNDERSHOWER ACTIVITY ACROSS MUCH OF CENTRAL ARIZONA. DEEP PLUME OF
TROPICAL MOISTURE OVERSPREADING THE REGION...WITH PWATS PUSHING 2
INCHES EARLIER IN THE DAY...WITH BLENDED TPW CURRENTLY SHOWING 1.75
INCH AMOUNTS ACROSS CENTRAL ARIZONA. CUT-OFF UPPER TROUGH/LOW TO OUR
WEST CONTINUED A SLOW EASTWARD PROGRESSION THROUGH THE DAY...ADDING
FAVORABLE CYCLONIC SPIN ACROSS THE AREA. COUPLE THAT WITH ADDITIONAL
EMBEDDED SHORTWAVES/IMPULSES AROUND THE RIDGE FLOW TO OUR EAST
OCCURRING DURING THE MIDDAY HOURS...AND WIDESPREAD SHOWER AND STORM
DEVELOPMENT ENSUED.
SCATTERED STORM ACTIVITY CONTINUES ACROSS WESTERN ARIZONA AND TO A
MORE ISOLATED EFFECT ACROSS SOUTHEAST CALIFORNIA...WHERE SKIES WERE
CLEAR FOR MUCH OF THE DAY. RADAR LOOP OF THE REGION SHOWS THE BROAD
UPPER LOW CIRCULATION JUST REACHING THE COLORADO RIVER VALLEY AND
THAT WILL AID IN FURTHER SHOWER AND STORM DEVELOPMENT THROUGH THE
EVENING. WITH THE AMOUNT OF TROPICAL MOISTURE AVAILABLE...EXPECT
EVEN SMALL SHOWERS TO HAVE HEAVY RAINFALL POTENTIAL. EVEN WITH THE
EARLIER SHOWER ACTIVITY WITH THE BROAD SCALE DYNAMICS AND CONTINUED
MOISTURE PRESENCE...UNSETTLED SHOWERY AND THUNDERSHOWER CONDITIONS
WILL PERSIST EVEN BACK INTO CENTRAL ARIZONA TONIGHT. CONDITIONS COULD
BE COME UNSTABLE ENOUGH ACROSS CENTRAL ARIZONA NOW THAT CONDITIONS
HAVE CLEAR TO SEE STORMS ACROSS WESTERN ARIZONA MOVE INTO THE PHOENIX
AREA AGAIN...PRODUCING ADDITIONAL HEAVY RAINFALL THROUGHOUT THE
EVENING.
MAINTAINED LIKELY SHOWER MENTION WITH CONTINUED ISOLATED THUNDER
THROUGH LATE EVENING...WITH THUNDERSHOWER CHANCES INTO EARLY TUESDAY
MORNING FOR MUCH OF THE FORECAST AREA. FOR TUESDAY...VERY SIMILAR
SET-UP...WITH THE CONTINUAL PRESENCE OF THE UPPER LOW/TROUGH
STALLING OUT NEAR THE COLORADO RIVER AND ADDITIONAL SPOKES OF
SHORTWAVE ENERGY MOVING THROUGH THE REGION. FORECAST MODEL SOUNDINGS
STILL HOLD ON TO AT LEAST 1.5 TO 1.7 INCHES PWAT THROUGH TUESDAY
EVENING. AM INCLINED TO WEIGHT THE FORECAST CLOSER TO THE NAM12 AND
NAMDNG5 FORECASTS...WHO HAVE BEEN THE BEST PERFORMERS IN TERMS OF
TEMPERATURE GUIDANCE AND CONVECTIVE/PRECIPITATION PLACEMENT RECENTLY.
ANOTHER BELOW NORMAL DAY EXPECTED WITH TEMPERATURES FORECAST AREA
WIDE...WITH THE WESTERN DESERTS OF IMPERIAL COUNTY AND FAR WESTERN
ARIZONA SEEING THE BEST CHANCES FOR CLEAR ENOUGH TO SKIES TO WARM
INTO THE 90S TUESDAY.
MINOR DETAILS FROM THE GUIDANCE WILL BE VERY HARD TO RESOLVE OVER
THE NEXT FEW DAYS...SUCH AS THE LITTLE DISTURBANCES/VORT MAXES MOVING
THROUGH THE FLOW. HOWEVER...BASIC FORECAST IDEA IS HANDLED FAIRLY
WELL AND THE PROGS CONTINUE TO ADVERTISE THE UPPER LOW TO MORE OR
LESS REMAIN IN PLACE THROUGH TUESDAY NIGHT. A SERIES OF VORT SPOKES
WILL ROTATE AROUND THE LOW...AND ADDITIONAL VORT MAXES WILL MOVE
NORTH OUT OF MEXICO...AND THESE FEATURES WILL ACT ON A VERY MOIST AND
RATHER UNSTABLE AIRMASS TO PRODUCE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS. UNLIKE A MORE NORMAL MONSOONAL PATTERN THE
SHOWERS/STORMS WILL BE ABLE TO OCCUR AT ANY TIME...NOT THE FAVORED
LATE AFTERNOON AND EVENING TIMES DURING A TYPICAL MONSOON DAY.
THUS...POPS WILL BE VERY HIGH AND BROAD BRUSHED THROUGH TUESDAY
NIGHT...WITH GOOD CHANCE TO LIKELY NUMBERS ACROSS MOST OF THE CWA
EACH PERIOD. GIVEN THE HIGH MOISTURE CONTENT THE PRIMARY WEATHER
THREAT WILL BE LOCALLY HEAVY RAIN WHICH COULD LEAD TO SOME FLOODING
OR FLASH FLOODING. OF COURSE GUSTY WINDS ARE POSSIBLE...SUCH AS SEEN
IN A WET MICROBURST...BUT HEAVY RAIN IS A MORE LIKELY OCCURRENCE. MAX
TEMPS ARE FORECAST TO RUN WELL BELOW SEASONAL NORMALS TODAY AND
TUESDAY...ESPECIALLY OVER SOUTH CENTRAL AZ WHERE HIGHS BOTH DAYS WILL
STRUGGLE TO REACH INTO THE LOW OR MID 90S.
BY WEDNESDAY THE LOW TO OUR WEST IS FORECAST TO MIGRATE NORTHWARD
INTO NORTHERN AZ OR SOUTHERN NEVADA/UTAH. AS THIS OCCURS STEERING
FLOW BECOMES SOUTHWEST TO WEST AND THIS WILL LEAD TO A GRADUAL
EROSION OF MOISTURE AND A DECREASE IN OUR POP TRENDS. BY WED EVENING
POPS WILL LOWER TO MOSTLY LESS THAN 25 PERCENT EXCEPT FOR HIGHER
TERRAIN AREAS EAST OF PHOENIX. HIGH TEMPS WILL STILL BE SUPPRESSED
AS MOISTURE WILL STILL BE SOMEWHAT ON THE HIGH SIDE. FOR THURSDAY
INTO THE WEEKEND...THE PERSISTENT WEST OR NORTHWEST STEERING FLOW
WILL CONTINUE TO ERODE MOISTURE...AND POPS WILL LOWER INTO THE
SINGLE DIGITS OVER THE WESTERN DESERTS...WITH ONLY SLIGHT CHANCES
LEFT OVER SOUTH CENTRAL ARIZONA. IN FACT...BY THE WEEKEND STORMS
SHOULD BE MOSTLY CONFINED TO HIGHER TERRAIN LOCATIONS SOUTHEAST AND
EAST OF THE GREATER PHOENIX AREA...WITH MOSTLY SUNNY SKIES EXPECTED
ACROSS THE CENTRAL AND WESTERN DESERTS. OF COURSE THERE WILL BE A
WARMING TREND AS THE MOISTURE THINS...WITH TRIPLE DIGIT HIGHS
FORECAST OVER MOST OF THE LOWER DESERTS BY THURSDAY. HIGHS SHOULD
REACH BACK TO SEASONAL NORMALS ACROSS THE CENTRAL AZ DESERTS BY THE
WEEKEND.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
ANTICIPATE QUIET CONDITIONS THROUGH 07Z BEFORE ANOTHER DISTURBANCE
BEGINS TO BRING SHOWERS AND ISOLATED THUNDERSTORMS TO SOUTH-CENTRAL
ARIZONA. HOWEVER...MAIN AREA OF ACTIVITY EXPECTED TO BE FOCUSED MORE
OVER THE HIGHER TERRAIN JUST EAST OF THE METRO AREA. MOISTURE
AVAILABILITY NOT AS GOOD AS MONDAY MORNING WAS AND THUS NOT
EXPECTING A REPEAT. HOWEVER...FOCUS AREA COULD EASILY WIND UP OVER
PHOENIX AREA. FOR NOW...WILL HOLD ON TO VCSH IN TAFS. MAIN WINDOW
FOR PRECIP/CEILING POTENTIAL WILL BE PRIOR TO 20Z TUESDAY.
ANTICIPATE LIGHT AND VARIABLE WINDS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCATTERED LIGHT SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE
OVERNIGHT DUE TO A LINGERING UPPER LOW CENTERED OVER THE AREA. WILL
HOLD ON TO VCSH IN TAFS. SOME AFTERNOON REDEVELOPMENT OF TSTMS IS
POSSIBLE BUT CONFIDENCE TOO LOW TO REFLECT IN TAFS. OTHERWISE
ANTICIPATE LIGHT AND VARIABLE WINDS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
DRIER AND WARMER CONDITIONS WILL PREVAIL THIS PERIOD. LIGHT WIND.
ISOLATED AFTERNOON AND EVENING TSTMS POSSIBLE HIGHER TERRAIN OF
SOUTHERN GILA COUNTY. MINIMUM RELATIVE HUMIDITIES WILL GENERALLY
FALL INTO THE TEENS ON THE DESERTS...AND NEAR 30 PERCENT IN THE
HIGHER TERRAIN OF SOUTHERN GILA COUNTY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
PREVIOUS DISCUSSION...NOLTE/CB
AVIATION....AJ
FIRE WEATHER...VASQUEZ
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
821 PM MDT WED SEP 11 2013
.UPDATE...
ISSUED AT 820 PM MDT WED SEP 11 2013
SHOWERS AND THUNDERSTORMS ALMOST NON-EXISTENT ACROSS SOUTHEAST
UTAH AND SOUTHWEST COLORADO THIS EVENING. MID-LEVEL SUBSIDENCE
INVERSION APPARENT IN 00Z/THU KGJT SOUNDING COMBINED WITH DIURNAL
COOLING LIKELY TO KEEP SHOWERS AND THUNDERSTORMS IN CHECK DURING
MUCH OF THE REMAINDER OF THE NIGHT. THEREFORE...CANCELED THE FLASH
FLOOD WATCH A BIT EARLY. AN AREA OF SHOWERS WITH A FEW EMBEDDED
THUNDERSTORMS CONTINUED OVER PORTIONS OF THE FLAT TOPS AND GORE
RANGE. EXPECT THIS ACTIVITY WILL CONTINUE TO WEAKEN AS IT MOVES
SLOWLY NORTH-NORTHWEST THROUGH THE REMAINDER OF THE EVENING.
&&
.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...NONE.
UT...NONE.
&&
$$
UPDATE...NL
SHORT TERM...TGR
LONG TERM...JAM
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS PUEBLO CO
602 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--
&&
.HYDROLOGY...
ISSUED AT 557 PM MDT WED SEP 11 2013
FROM THE MOTION OF THE MOSAIC RADAR IMAGERY...ANOTHER VORTMAX IS
LIKELY LOCATED OVER PUEBLO COUNTY. THIS ONE DOES NOT APPEAR TO BE
AS WELL DEFINED AS THIS MORNINGS VORT MAX. NONETHELESS...WE WILL
CAREFULLY BE WATCHING FOR INCREASING ECHOES OVER THE WALDO BURN
SCAR. HRRR HAS BEEN TRYING TO DISSIPATE THIS AREA OF RAIN FOR THE
LAST FEW RUNS AND IT HAS NOT HAPPENED YET. THE GROUND IS SATURATED
OVER THE BURN SCAR AND IT WILL NOT TAKE TOO MUCH TO CAUSE
PROBLEMS. /HODANISH
&&
.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
HYDROLOGY...HODANISH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
931 AM MDT TUE SEP 10 2013
.UPDATE...A MOIST SOUTH-SOUTHWEST FLOW ALOFT WILL CONTINUE TO
PREVAIL THROUGH TONIGHT. IT APPEARS ON SATELLITE THAT A WAVE IS
MOVING ACROSS THE FOUR CORNERS AND IS TRIGGERING SHOWERS ACROSS
SOUTHEAST UTAH...SOUTHWEST COLORADO AND WESTERN NEW MEXICO. EVEN
THOUGH THE 06Z GFS HAS DRY CONDITIONS OVER NORTHEAST COLORADO THIS
AFTERNOON...EXPECT THE SHOWERS AND SCATTERED THUNDERSTORMS TO
FORM AS THIS WAVE SHIFT TO THE NORTHEAST. THE HRRR...RAP...AND
ECMWF ALL SUPPORT THIS. BEST CHANCE WILL BE OVER THE MOUNTAINS. IT
WILL WARM INTO THE 70S OVER FAR EASTERN COLORADO WHERE IT IS
PARTLY CLOUDY TO SUNNY. THIS WILL PRODUCE CAPES OF UP TO 500 J/KG.
THIS IS WHERE THE BEST CHANCE FOR STORMS WILL BE THIS AFTERNOON.
DECREASED TEMPERATURES A FEW DEGREES ALONG THE FRONT RANGE WHERE
CLOUD COVER WILL KEEP TEMPERATURES IN THE 60S TODAY. DID BUMP UP
POPS WEST OF INTERSTATE 25 WHERE SHOWERS AND A FEW THUNDERSTORMS
APPEAR LIKELY TODAY.
FOR TONIGHT...SOME DISAGREEMENT AMONG THE MODELS. ECMWF AND RAP
SHOW WIDESPREAD RAIN FROM GREELEY TO DIA AND WEST...WHILE THE NAM
AND GFS ARE DRY. FAVOR THE RAP AND ECMWF AT THIS TIME. RAISED
POPS FOR TONIGHT BUT WILL KEEP THEM IN 50-70 PERCENT RANGE UNTIL
IT BECOMES MORE CERTAIN THAT RAIN WILL OCCUR.
&&
.AVIATION...VERY LOW CEILINGS...LESS THAN 1000 FEET MAY LINGER
UNTIL 18Z ALONG THE FRONT RANGE. ELSEWHERE ACROSS THE DENVER
AREA...CEILINGS OF 1500 TO 3000 FEET WILL CONTINUE THROUGH 18Z.
CEILINGS WILL REMAIN 2500 TO 5000 THROUGH THE DAY TODAY. MAY BE
SOME SLIGHT VISIBILITY RESTRICTIONS UNDER THE STRONGER SHOWERS.
CEILINGS WILL LOWER AGAIN TONIGHT AND MAY DROP BELOW 1000 FEET
BETWEEN 06Z AND 18Z WEDNESDAY. IN ADDITION TO THE RAIN SHOWERS...A
FEW EMBEDDED THUNDERSTORMS WILL BE POSSIBLE BETWEEN 20Z AND 03Z
TODAY.
&&
.PREV DISCUSSION... /ISSUED 307 AM MDT TUE SEP 10 2013/
SHORT TERM...AN UPPER LEVEL LOW WILL REMAIN OVER THE SWRN US AS
DISTURBANCES EMBEDDED IN THE FLOW OF SUBTROPICAL MOISTURE MOVE
NNE ACROSS COLORADO. ONE WELL DEFINED FEATURE IS ALREADY MOVING
NORTHWARD OVER WRN CO EARLY THIS MORNING AND IS HELPING MAINTAIN
SHOWER ACTIVITY IN THE MTNS AND ALONG AND NR THE FOOTHILLS. AS
THIS FEATURE CONTINUES TO LIFT NORTH WOULD EXPECT SHOWER ACTIVITY
TO DECREASE BY MID MORNING IN MOST AREAS.
FOR THIS AFTN THERE IS A 2ND FEATURE CURRENTLY NOW ALONG THE ECTRL
AZ-WCNTRL NM BORDER WHICH IS MOVING NNE AS WELL. AS THIS FEATURE
LIFTS NNE INTO SWRN CO BY AFTN WOULD EXPECT SHOWERS AND TSTMS TO
INCREASE IN THE MTNS. EAST OF THE MTNS NOT SURE HOW THINGS ARE
GOING TO EVOLVE THIS AFTN. THE LATST HRRR DEVELOPS A WEAK CYCLONE
OVER SRN DOUGLAS COUNTY THIS AFTN WITH MAINLY ELY LOW LVL FLOW
OVER NERN CO. THE HRRR WARMS HIGHS INTO THE MID TO UPPER 70S OVER
THE PALMER DIVIDE WHILE FURTHER NORTH READINGS ARE ONLY IN THE
UPPER 60S TO NEAR 70 FM NORTH OF DENVER TO THE WY BORDER. IF THIS
ENDS UP BEING CORRECT THEN THE BEST CHC OF STRONGER STORMS WOULD
BE FM THE SRN FOOTHILLS ACROSS THE PALMER DIVIDE WHILE ACTIVITY
FURTHER NORTH WOULD NOT BE AS STG AND LESS WIDESPREAD. SO WILL
KEEP THE HIGHEST POPS FM DENVER SOUTH TO THE PALMER DIVIDE TOWARDS
LIMON. WITH PRECIPITABLE WATER VALUES RANGING FM 1.10 TO 1.20
INCHES THE STRONGER STORMS COULD EASILY PRODUCE UP TO 2 INCHES OF
RAIN IN LESS THAN AN HOUR. MEANWHILE OVER THE NERN PLAINS TEMPS
LOOK LIKE THEY WILL BE IN THE UPPER 70S TO LOWER 80S WITH TSTM
COVERAGE NOT AS GREAT.
FOR TONIGHT THE DISTURBANCE OVER SWRN CO WILL PROBABLY MOVE NNE
ACROSS THE MTNS AS SHOWN BY THE LATEST ECMWF. AS A RESULT THERE
WILL BE ADDITIONAL SHOWERS AND A FEW TSTMS IN THE MTNS WITH SOME OF
THIS ACTIVITY SPREADING ACROSS THE FOOTHILLS AND PORTIONS OF THE
URBAN CORRIDOR OVERNIGHT.
LONG TERM...MODELS CONTINUE TO INDICATE A DEEP...ANOMALOUSLY
MOIST SUBTROPICAL FLOW OVER NEW MEXICO...COLORADO AND THE WESTERN
GREAT PLAINS WEDNESDAY AND THURSDAY. MEAN LAYER PRECIPITABLE WATER
VALUES QUITE IMPRESSIVE FOR THIS TIME OF YEAR OVER EASTERN
COLORADO. VALUES MORE OFTEN OBSERVED IN JULY-EARLY AUGUST. FOR
INSTANCE...THE NAM...GFS...WRF AND SREF INDICATE PW VALUES UP
AROUND 1.25 INCHES ALONG THE FRONT RANGE FOOTHILLS WEDNESDAY
AFTERNOON. GFS STAYS JUST AS MOIST WEDNESDAY NIGHT AND
THURSDAY...WHILE THE NAM AND SREF INDICATE SOME DRYING ON
THURSDAY...BUT PW VALUES STILL ABOVE THE CLIMATOLOGICAL NORM. THIS
MOIST SOUTHERLY FLOW IS DRIVEN BY A NEARLY VERTICALLY STACKED
CYCLONE CENTERED NEAR LAS VEGAS ON WEDNESDAY. MODELS SHOW LITTLE
MOVEMENT IN THIS FEATURE THROUGH WEDNESDAY NIGHT. DIVERGENT FLOW
ALOFT EAST OF THE LOW OVER COLORADO IS PROGGED TO STRENGTHEN SOME
ON THURSDAY AS THE CYCLONE BEGINS ITS SLOW NORTHWARD MIGRATION.
STRONGEST UPWARD QUASI-GEOSTROPHIC VERTICAL VELOCITIES WEDNESDAY/
THURSDAY OVER EASTERN UTAH AND WESTERN COLORADO...WITH WEAK
RISING MOTIONS OVER EASTERN COLORADO. BY FRIDAY...MODELS SHOW THE
MEAN UPPER LOW OVER NRN UTAH/SERN IDAHO AND A SOUTHWESTERLY FLOW
OVER COLORADO. THIS WILL LOWER PW AND SPECIFIC HUMIDITY VALUES
ACROSS THE FORECAST AREA ON SATURDAY...PARTICULARLY IN THE HIGH
COUNTRY AS THE CLOSED UPPER CYCLONE OPENS UP INTO A TROUGH AND
SWINGS EAST OVER MONTANA AND WYOMING. BY SUNDAY ECMWF AND GFS
SHOW THE TROUGH PASSING OVER THE DAKOTAS ON SUNDAY...WITH THE
TAIL END OF THIS TROUGH AND WHAT APPEARS TO BE A COLD FRONT
BRUSHING NORTHEAST COLORADO. THIS WILL COOL TEMPERATURES BY AT
LEAST A FEW DEGS AND GIVE THE AREA ANOTHER CHANCE OF SHOWERS.
THEREFORE...WILL HANG ONTO THE HIGH POPS ON WEDNESDAY AND
THURSDAY...AND WITH THE WETBULB ZERO LOWERING LATE WEDNESDAY AND
THURSDAY...COULD SEE A SOME SNOW ACCUMULATION ON THE HIGHER PEAKS.
INSTABILITY WILL BE LIMITED DUE TO A HEAVY CLOUD COVER AND COOLER
TEMPERATURES. THIS WILL LIMIT THUNDERSTORM DEVELOPMENT AND THE
CHANCE OF HEAVY RAINFALL. SFC TEMPERATURES ARE LIKELY TO BE WELL
BELOW AVERAGE THROUGH AT LEAST THURSDAY NIGHT. LATEST NAM AND GFS
TEMPERATURE GUIDANCE FOR BOTH DAYS NOW LOOKS SLIGHTLY COOLER THAN
EARLIER GUIDANCE INDICATED. ECMWF TEMP GUIDANCE IS NOT AS COOL.
FCST HIGH TEMPERATURES BOTH DAYS IN THE 60S AT LOWER ELEVATIONS
AND 40S TO AROUND 60 IN THE HIGH COUNTRY. AT ANY RATE...IT`LL
DEFINITELY FEEL FALL-LIKE AFTER THE RECORD/NEAR RECORD HEAT OF THE
PAST COUPLE WEEKS. CONDITIONS SHOULD BEGIN TO WARM AND DRY OUT
FROM WEST TO EAST...SLOWLY AT FIRST...ON FRIDAY AND SATURDAY.
SHOULD SEE A MOVE AWAY FROM UPSLOPE TYPE STRATIFORM PRECIP TO
CONVECTIVE PRECIP/T-STORM ACTIVITY ON SATURDAY WITH THE LIFT
GENERATED BY THE TROUGH PASSING TO OUR NORTH AND WITH MORE SOLAR
HEATING. TEMPERATURES SHOULD BE NEAR AVERAGE ON SATURDAY. THEN A
DIP IN TEMPERATURE AND ANOTHER CHANCE OF SHOWERS ON SUNDAY WITH
THE PASSAGE OF THE COLD FRONT REFERRED TO ABOVE. BY MONDAY...
MODELS SHOW A RETURN TO DRIER AND WARMER CONDITIONS WITH WEST-
NORTHWESTERLY FLOW ALOFT AND DOWNSLOPE FLOW DOWN LOW.
AVIATION...A FEW SHOWERS MAY AFFECT THE AREA EARLY THIS MORNING
WITH BRIEF MVFR CONDITIONS POSSIBLE. WITH 5000-6000 FOOT CEILINGS
AROUND NOT SURE IF IFR CONDITIONS ARE GOING TO DVLP BUT AM NOT
CONFIDENT ENOUGH TO TOTALLY YANK THEM OUT AT THIS POINT.
FOR THIS AFTN SFC WINDS SHOULD BE MAINLY ELY. AS TALKED ABOUT ABV
BEST CHC OF STRONGER STORMS LOOKS TO BE FM DENVER SOUTH TO THE
PALMER DIVIDE WITH ACTIVITY DEVELOPING BY 20Z-21Z. DIA MAY END UP
BEING ON THE NRN FRINGE OF THE STRONGER ACTIVITY. HOWEVER IF A
STRONGER STORM WERE TO MOVE ACROSS THEN MVFR CONDITIONS COULD
BRIEFLY OCCUR.
BY TONIGHT INITIAL BATCH OF SHOWERS AND TSTMS WILL PROBABLY DIMINISH
BY 01Z HOWEVER SOME ADDITIONAL SHOWERS AND POSSIBLY A TSTM COULD
REDEVELOP AFTER MIDNIGHT AS A 2ND DISTURBANCE MOVES ACROSS. ONCE
AGAIN THERE COULD BE SOME POTENTIAL FOR STRATUS AND FOG BY 12Z WED
IF SKIES CLEAR LATE.
HYDROLOGY...SHOWERS AND THUNDERSTORMS WILL INCREASE BY EARLY
AFTERNOON IN THE MOUNTAINS...FOOTHILLS AND ALONG THE FRONT RANGE.
AT THIS TIME IT APPEARS THE STRONGEST STORMS WILL FOCUS FROM
DENVER SOUTHWARD ACROSS THE PALMER DIVIDE INTO THE SOUTHERN
FOOTHILLS. RAINFALL AMOUNTS OF 1 TO 2 INCHES WILL BE POSSIBLE WITH
THE STRONGER STORMS IN LESS THAN 45 MINUTES.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM....BAKER
AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
307 AM MDT TUE SEP 10 2013
.SHORT TERM...AN UPPER LEVEL LOW WILL REMAIN OVER THE SWRN US AS
DISTURBANCES EMBEDDED IN THE FLOW OF SUBTROPICAL MOISTURE MOVE
NNE ACROSS COLORADO. ONE WELL DEFINED FEATURE IS ALREADY MOVING
NORTHWARD OVER WRN CO EARLY THIS MORNING AND IS HELPING MAINTAIN
SHOWER ACTIVITY IN THE MTNS AND ALONG AND NR THE FOOTHILLS. AS
THIS FEATURE CONTINUES TO LIFT NORTH WOULD EXPECT SHOWER ACTIVITY
TO DECREASE BY MID MORNING IN MOST AREAS.
FOR THIS AFTN THERE IS A 2ND FEATURE CURRENTLY NOW ALONG THE ENCTRL
AZ-WCNTRL NM BORDER WHICH IS MOVING NNE AS WELL. AS THIS FEATURE
LIFTS NNE INTO SWRN CO BY AFTN WOULD EXPECT SHOWERS AND TSTMS
TO INCREASE IN THE MTNS. EAST OF THE MTNS NOT SURE HOW THINGS ARE
GOING TO EVOLVE THIS AFTN. THE LATST HRRR DEVELOPS A WEAK CYCLONE
OVER SRN DOUGLAS COUNTY THIS AFTN WITH MAINLY ELY LOW LVL FLOW
OVER NERN CO. THE HRRR WARMS HIGHS INTO THE MID TO UPPER 70S OVER
THE PALMER DIVIDE WHILE FURTHER NORTH READINGS ARE ONLY IN THE
UPPER 60S TO NEAR 70 FM NORTH OF DENVER TO THE WY BORDER. IF THIS
ENDS UP BEING CORRECT THEN THE BEST CHC OF STRONGER STORMS WOULD
BE FM THE SRN FOOTHILLS ACROSS THE PALMER DIVIDE WHILE ACTIVITY
FURTHER NORTH WOULD NOT BE AS STG AND LESS WIDESPREAD. SO WILL
KEEP THE HIGHEST POPS FM DENVER SOUTH TO THE PALMER DIVIDE TOWARDS
LIMON. WITH PRECIPITABLE WATER VALUES RANGING FM 1.10 TO 1.20
INCHES THE STRONGER STORMS COULD EASILY PRODUCE UP TO 2 INCHES OF
RAIN IN LESS THAN AN HOUR. MEANWHILE OVER THE NERN PLAINS TEMPS
LOOK LIKE THEY WILL BE IN THE UPPER 70S TO LOWER 80S WITH TSTM
COVERAGE NOT AS GREAT.
FOR TONIGHT THE DISTURBANCE OVER SWRN CO WILL PROBABLY MOVE NNE
ACROSS THE MTNS AS SHOWN BY THE LATEST ECMWF. AS A RESULT THERE
WILL BE ADDITIONAL SHOWERS AND A FEW TSTMS IN THE MTNS WITH SOME OF
THIS ACTIVITY SPREADING ACROSS THE FOOTHILLS AND PORTIONS OF THE
URBAN CORRIDOR OVERNIGHT.
.LONG TERM...MODELS CONTINUE TO INDICATE A DEEP...ANOMALOUSLY
MOIST SUBTROPICAL FLOW OVER NEW MEXICO...COLORADO AND THE WESTERN
GREAT PLAINS WEDNESDAY AND THURSDAY. MEAN LAYER PRECIPITABLE WATER
VALUES QUITE IMPRESSIVE FOR THIS TIME OF YEAR OVER EASTERN
COLORADO. VALUES MORE OFTEN OBSERVED IN JULY-EARLY AUGUST. FOR
INSTANCE...THE NAM...GFS...WRF AND SREF INDICATE PW VALUES UP
AROUND 1.25 INCHES ALONG THE FRONT RANGE FOOTHILLS WEDNESDAY
AFTERNOON. GFS STAYS JUST AS MOIST WEDNESDAY NIGHT AND
THURSDAY...WHILE THE NAM AND SREF INDICATE SOME DRYING ON
THURSDAY...BUT PW VALUES STILL ABOVE THE CLIMATOLOGICAL NORM. THIS
MOIST SOUTHERLY FLOW IS DRIVEN BY A NEARLY VERTICALLY STACKED
CYCLONE CENTERED NEAR LAS VEGAS ON WEDNESDAY. MODELS SHOW LITTLE
MOVEMENT IN THIS FEATURE THROUGH WEDNESDAY NIGHT. DIVERGENT FLOW
ALOFT EAST OF THE LOW OVER COLORADO IS PROGGED TO STRENGTHEN SOME
ON THURSDAY AS THE CYCLONE BEGINS ITS SLOW NORTHWARD MIGRATION.
STRONGEST UPWARD QUASI-GEOSTROPHIC VERTICAL VELOCITIES WEDNESDAY/
THURSDAY OVER EASTERN UTAH AND WESTERN COLORADO...WITH WEAK
RISING MOTIONS OVER EASTERN COLORADO. BY FRIDAY...MODELS SHOW THE
MEAN UPPER LOW OVER NRN UTAH/SERN IDAHO AND A SOUTHWESTERLY FLOW
OVER COLORADO. THIS WILL LOWER PW AND SPECIFIC HUMIDITY VALUES
ACROSS THE FORECAST AREA ON SATURDAY...PARTICULARLY IN THE HIGH
COUNTRY AS THE CLOSED UPPER CYCLONE OPENS UP INTO A TROUGH AND
SWINGS EAST OVER MONTANA AND WYOMING. BY SUNDAY ECMWF AND GFS
SHOW THE TROUGH PASSING OVER THE DAKOTAS ON SUNDAY...WITH THE
TAIL END OF THIS TROUGH AND WHAT APPEARS TO BE A COLD FRONT
BRUSHING NORTHEAST COLORADO. THIS WILL COOL TEMPERATURES BY AT
LEAST A FEW DEGS AND GIVE THE AREA ANOTHER CHANCE OF SHOWERS.
THEREFORE...WILL HANG ONTO THE HIGH POPS ON WEDNESDAY AND
THURSDAY...AND WITH THE WETBULB ZERO LOWERING LATE WEDNESDAY AND
THURSDAY...COULD SEE A SOME SNOW ACCUMULATION ON THE HIGHER PEAKS.
INSTABILITY WILL BE LIMITED DUE TO A HEAVY CLOUD COVER AND COOLER
TEMPERATURES. THIS WILL LIMIT THUNDERSTORM DEVELOPMENT AND THE
CHANCE OF HEAVY RAINFALL. SFC TEMPERATURES ARE LIKELY TO BE WELL
BELOW AVERAGE THROUGH AT LEAST THURSDAY NIGHT. LATEST NAM AND GFS
TEMPERATURE GUIDANCE FOR BOTH DAYS NOW LOOKS SLIGHTLY COOLER THAN
EARLIER GUIDANCE INDICATED. ECMWF TEMP GUIDANCE IS NOT AS COOL.
FCST HIGH TEMPERATURES BOTH DAYS IN THE 60S AT LOWER ELEVATIONS
AND 40S TO AROUND 60 IN THE HIGH COUNTRY. AT ANY RATE...IT`LL
DEFINITELY FEEL FALL-LIKE AFTER THE RECORD/NEAR RECORD HEAT OF THE
PAST COUPLE WEEKS. CONDITIONS SHOULD BEGIN TO WARM AND DRY OUT
FROM WEST TO EAST...SLOWLY AT FIRST...ON FRIDAY AND SATURDAY.
SHOULD SEE A MOVE AWAY FROM UPSLOPE TYPE STRATIFORM PRECIP TO
CONVECTIVE PRECIP/T-STORM ACTIVITY ON SATURDAY WITH THE LIFT
GENERATED BY THE TROUGH PASSING TO OUR NORTH AND WITH MORE SOLAR
HEATING. TEMPERATURES SHOULD BE NEAR AVERAGE ON SATURDAY. THEN A
DIP IN TEMPERATURE AND ANOTHER CHANCE OF SHOWERS ON SUNDAY WITH
THE PASSAGE OF THE COLD FRONT REFERRED TO ABOVE. BY MONDAY...
MODELS SHOW A RETURN TO DRIER AND WARMER CONDITIONS WITH WEST-
NORTHWESTERLY FLOW ALOFT AND DOWNSLOPE FLOW DOWN LOW.
&&
.AVIATION...A FEW SHOWERS MAY AFFECT THE AREA EARLY THIS MORNING
WITH BRIEF MVFR CONDITIONS POSSIBLE. WITH 5000-6000 FOOT CEILINGS
AROUND NOT SURE IF IFR CONDITIONS ARE GOING TO DVLP BUT AM NOT
CONFIDENT ENOUGH TO TOTALLY YANK THEM OUT AT THIS POINT.
FOR THIS AFTN SFC WINDS SHOULD BE MAINLY ELY. AS TALKED ABOUT ABV
BEST CHC OF STRONGER STORMS LOOKS TO BE FM DENVER SOUTH TO THE
PALMER DIVIDE WITH ACTIVITY DEVELOPING BY 20Z-21Z. DIA MAY END UP
BEING ON THE NRN FRINGE OF THE STRONGER ACTIVITY. HOWEVER IF A
STRONGER STORM WERE TO MOVE ACROSS THEN MVFR CONDITIONS COULD
BRIEFLY OCCUR.
BY TONIGHT INITIAL BATCH OF SHOWERS AND TSTMS WILL PROBABLY DIMINISH
BY 01Z HOWEVER SOME ADDITIONAL SHOWERS AND POSSIBLY A TSTM COULD
REDEVELOP AFTER MIDNIGHT AS A 2ND DISTURBANCE MOVES ACROSS. ONCE
AGAIN THERE COULD BE SOME POTENTIAL FOR STRATUS AND FOG BY 12Z WED
IF SKIES CLEAR LATE.
&&
.HYDROLOGY...SHOWERS AND THUNDERSTORMS WILL INCREASE BY EARLY
AFTERNOON IN THE MOUNTAINS...FOOTHILLS AND ALONG THE FRONT RANGE.
AT THIS TIME IT APPEARS THE STRONGEST STORMS WILL FOCUS FROM
DENVER SOUTHWARD ACROSS THE PALMER DIVIDE INTO THE SOUTHERN
FOOTHILLS. RAINFALL AMOUNTS OF 1 TO 2 INCHES WILL BE POSSIBLE WITH
THE STRONGER STORMS IN LESS THAN 45 MINUTES.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....RPK
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1111 PM MDT MON SEP 9 2013
.UPDATE...
ISSUED AT 907 PM MDT MON SEP 9 2013
IN THE SHORT TERM...ONE FEATURE STANDS OUT AND THAT IS THE MASS OF
HIGH CLOUD TOPS OVER SE UTAH AND SW COLORADO. LATEST SATELLITE
IMAGERY SHOW WARMING CLOUD TOPS...BUT CONVECTIVE CELLS STILL
CAPABLE OF GENERATING HEAVY SHOWERS WITH CORTEZ ASOS PICKING UP
FOUR TENTHS OF AN INCH IN A SHORT PERIOD OF TIME. THE HRRR SHOW
A BROAD AREA OF ONE HALF TO ONE INCH OF RAIN COVERING SW COLORADO
AND PORTIONS OF SE UTAH BY SUNRISE TUESDAY MORNING. THIS COULD BE
PROBLEMATIC AS SOILS MAY BECOME SATURATED WITH ENHANCED FLOWS IN
DRAINAGES OR NORMALLY DRY WASHES. THE ANTECEDENT CONDITIONS SETS
THE STAGE FOR WHAT IS EXPECTED ON TUESDAY.
TUESDAY...MODEL DATA SHOW A STRONG WAVE LIFTING NORTHWARD ACROSS
THE WESTERN SLOPE. THIS WAVE ENTERS SOUTHWEST COLORADO DURING THE
MORNING HOURS AND MOVES NORTHWARD DURING THE DAY...DEPARTING
NORTHWEST COLORADO LATE TUESDAY NIGHT. ASSOCIATED WITH THIS WAVE
IS DEEP LAYERED MOISTURE TRANSPORT...ISENTROPIC UPGLIDE...AND EVEN
SOME DYNAMICAL FORCING AS WELL TO ENHANCE LIFT. SPEED MAXIMA OF
50 KTS AT 300 MB WILL CREATE AN AREA OF UPPER LEVEL DIVERGENCE.
COMBINED WITH LOW LEVEL CONVERGENCE ASSOCIATED WITH THE BROAD AREA
OF SURFACE LOW PRESSURE...THE NET RESULT WILL BE DEEP CONVECTIVE
TOWERS WHERE CLOUD TOPS MAY BECOME COLDER THAN -60C.
RAINFALL AMOUNTS COULD EXCEED THOSE ON MONDAY...AND WITH SOILS AND
DRAINAGE AREAS BECOMING SATURATED (IF NOT ALREADY)...ADDITIONAL FLASH
FLOODING COULD RESULT. EXPANDED THE AREA OF POTENTIAL FLASH FLOODING
TO COVER THE REST OF THE WESTERN SLOPE THAT WAS NOT COVERED BY THE
WATCH EARLIER.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY NIGHT)
ISSUED AT 400 PM MDT MON SEP 9 2013
EXCEPTIONALLY WET PERIOD CONTINUES WITH WIDESPREAD PRECIPITATION
OCCURRING ACROSS BOTH CO AND UT WITH THIS TREND CONTINUING. WATER
VAPOR IMAGERY CURRENTLY SHOWING ANOMALOUS AMOUNTS OF MOISTURE
STREAMING UP FROM THE SOUTH WHILE A DEFORMATION AXIS HAS SET UP
OVER NEVADA INTO NRN UTAH. THIS AXIS IS ALLOWING MOISTURE AND
IMPULSES TO CONTINUE STREAMING INTO OUR AREA. LATEST GUIDANCE TO
INCLUDE THE NAM...RAP AND HRRR SHOW PRECIP CONTINUING THROUGH
TONIGHT AND THEN A RELATIVE LULL BEFORE ANOTHER WAVE CAUSES PRECIP
AGAIN DURING THE MORNING HOURS TOMORROW. WITH PLENTY OF RAIN
HAVING ALREADY FALLEN AND MORE ON THE WAY...EXTENDED THE FLASH
FLOOD WATCH THROUGH TUESDAY NIGHT AND ALSO ADDED THE UNCOMPAGHRE
AND ROAN/TAVAPUTS PLATEAUS SINCE THEY SAW THE BULK OF PRECIP
TODAY. SO FAR ONLY A FEW AREAS (PORTIONS OF ARCHES AND CANYONLANDS
NATIONAL PARK) HAVE REPORTED FLOODING DUE TO THE MAINLY STRATIFORM
NATURE OF THE PRECIP THOUGH A FEW EMBEDDED STORMS HAVE FIRED THIS
AFTERNOON. THE BIGGEST CONCERN HAS BEEN...AND CONTINUES TO
BE...SERN UTAH DUE TO THE SLOT CANYON AND DESERT TERRAIN. LOTS OF
CLOUDS HAVE INHIBITED CONVECTION SO FAR TODAY THOUGH VIS IMAGERY
DOES SHOW SOME BREAKS STARTING TO FORM. WILL ALERT NEXT SHIFTS TO
KEEP AN EYE ON AREA. MOST TEMPS ARE RUNNING ABOUT 5 TO 10 DEGREES
COOLER THAN NORMAL DUE TO RAINFALL AND CLOUDS.
OVERNIGHT...SOME MODELS DEPICT MORE STEADY PRECIP TO
CONTINUE...ESPECIALLY FOR THE ABAJOS...LA SALS AND
UNCOMPAGHRE/ROAN/TAVAPUTS PLATEAUS. OTHER MODELS SHOW MORE OF A
LULL. KEPT PRECIP IN FORECAST AS MOISTURE WILL CONTINUE TO STREAM
OVERHEAD AND ANY WEAK DISTURBANCE/IMPULSE WILL CREATE SHOWERS. FOR
TOMORROW THOUGH...MORE IMPULSES WILL CONTINUE TO MOVE OVER THE CWA
WITH WHAT APPEARS TO BE A SIGNIFICANT IMPULSE MOVING INTO THE 4
CORNERS BY 7AM AND THEN SPREADING NWRD BY NOON. FOR TUESDAY
THEN...ANOTHER DAY LIKE TODAY...CLOUDS...RAIN...COOL TEMPERATURES
WITH INCREASED FLOODING CONCERNS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 400 PM MDT MON SEP 9 2013
THE MAIN STORM TRACK WITH THE STRONGER WESTERLIES WILL REMAIN WELL
TO THE NORTH OF THE INTERMOUNTAIN WEST THROUGH THIS EXTENDED PERIOD.
BY WEDNESDAY STRONG TROUGHING INTO THE GREAT LAKES REGION AND INTO
THE GULF OF ALASKA LEAVES AN AMPLIFIED RIDGE OVER THE NORTHERN US
AND CANADIAN ROCKIES. THIS NORTHERN RIDGE WILL LEAD TO A REX PATTERN
DUE TO AN AREA OF LOW PRESSURE THAT GETS CUT OFF....AND WILL WOBBLE
AROUND THE GREAT BASIN. THIS LOW WILL BE HELD FROM MOVING WEST TO
EAST BY THE SUBTROPICAL HIGH OVER THE SOUTHEAST STATES AND PACIFIC
HIGH PRESSURE BUILDING TOWARD THE WEST COAST. THIS PATTERN WILL BE
STATIC THROUGH AT LEAST THURSDAY AFTER WHICH MEDIUM RANGE MODELS
SWING SOME STRONGER ENERGY INTO WESTERN CANADA...BREAKING THE REX
BLOCK...AND ALLOWING THE GREAT BASIN LOW TO TO BEGIN TO LIFT
NORTHWARD. HOWEVER THERE ARE MODEL CONFLICTS WITH HOW THIS LOW
INTERACTS WITH THE ENERGY BREAKING DOWN THE RIDGE BY LATE IN THE
FORECAST...LEAVING VERY LOW CONFIDENCE IN THE LATTER PERIODS SO
BLENDED MODELS GENERALLY FOLLOWED.
SO TO FOCUS ON THE PERIOD WHEN THE UPPER LOW IS CUTOFF IN THE GREAT
BASIN WEDNESDAY AND THURSDAY. THE MODELS ARE SIMILAR IN LIFTING ONE
LOBE OF STRONGER ENERGY NORTHWARD OUT OF OUR CWA ON
WEDNESDAY...WHILE ROTATING ANOTHER STRONG PIECE ACROSS UTAH ON
THURSDAY. SUBSIDENCE BEHIND THE FIRST WAVE WILL GENERALLY BRING
SOMEWHAT OF A DOWNTURN TO THE PRECIPITATION FOR WEDNESDAY...WITH THE
FAMILIAR PATTERN OF STORMS FOCUSING ON THE TERRAIN BY EARLY
AFTERNOON BEFORE SPREADING INTO THE VALLEYS. ASCENT WILL BEGIN TO
INCREASE SIGNIFICANTLY ON THURSDAY AFTERNOON OVER OUR CWA THURSDAY
WITH THE DYNAMIC TROP DIPPING DOWN TOWARD 400MB WHICH SHOULD ENHANCE
THE INSTABILITY AND BRING AN UPTURN TO STORMS FOR THURSDAY. THE
STRONGER MONSOON PLUME WILL GET DISRUPTED BUT STILL PLENTY OF
MOISTURE AROUND FOR MAKING STORMS. THE DRY CONVEYOR BELT ASSOCIATED
WITH THE PV LOBE MAY ALSO LEAD TO SOME STRONGER STORM DEVELOPMENT.
FROM FRIDAY ONWARD THE LOW WILL HAVE LIFTED NORTH AND EAST OF OUR
AREA BUT A RESIDUAL TROF REMAINS IN PLACE. MOISTURE WILL BEGIN TO
WANE BUT PWATS STILL HOVER AROUND OR JUST ABOVE NORMAL FOR MID
SEPTEMBER AND THIS WILL KEEP A THREAT OF SHOWERS AND THUNDERSTORMS
GOING INTO THE LATE PERIODS. TEMPERATURES THROUGH THE EXTENDED
PERIOD LOOK TO HOVER NEAR THE SEASONAL NORMALS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1109 PM MDT MON SEP 9 2013
RAINFALL CONTINUES FOR MUCH OF THE NEXT 24 HOURS. MVFR AND OCCNL
IFR IS EXPECTED THROUGH THE MORNING HOURS WITH LOW CIGS AND VIS UNDER
THE STRONGER SHOWERS AND STORMS THAT FORM. FOG WILL ALSO BE A
CONCERN ESPECIALLY IN THE MORNING DUE TO AMOUNT OF MOISTURE IN THE
AIR. ALL TAF SITES ARE UNDER THE GUN FOR PRECIP...LOW CLOUDS AND
VISIBILITIES THROUGH 06Z TOMORROW. MOUNTAIN OBSCURATIONS CAN BE
EXPECTED OVER ALL HIGHER TERRAIN.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR COZ003-017-020-021.
FLASH FLOOD WATCH FROM 9 AM MDT TUESDAY THROUGH TUESDAY EVENING
FOR COZ001-002-004>014-018-019-022-023.
UT...FLASH FLOOD WATCH THROUGH TUESDAY EVENING FOR UTZ022-025-027>029.
&&
$$
UPDATE...PF
SHORT TERM...TGR
LONG TERM...15
AVIATION...JDC
AREA FORECAST DISCUSSION
NWS ALBANY NY
740 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/...
SHOWERS AND THUNDERSTORMS MOVING ACROSS THE REGION THIS EVENING. THE
MOST INTENSE STORMS HAVE MOVED EAST OF KGFL...ALTHOUGH ADDITIONAL
SHRA/TSRA WITH OCCASIONAL LIGHTNING WILL MOVE THROUGH ALL OF THE
TERMINALS THROUGH AROUND 02Z-03Z. WILL MENTION TEMPO GROUPS FOR
MVFR CONDITIONS. TSRA HAVE YET TO IMPACT KPOU...BUT SHOULD
MOVE INTO THE VICINITY BY AROUND 01Z. CONVECTIVE ACTIVITY IS
EXPECTED TO GRADUALLY WEAKEN AND DIMINISH BY LATE EVENING...WITH
JUST A FEW LEFTOVER SHOWERS THROUGH AROUND MIDNIGHT OR EARLY
THURSDAY MORNING.
THE NEXT CHALLENGE WILL BECOME FOG DEVELOPMENT IN WAKE OF THE
RAINFALL FROM THIS EVENING. SKIES MAY NOT CLEAR ENOUGH FOR THICK FOG
FORMATION...ALTHOUGH IFR WILL BE POSSIBLE ESPECIALLY AT FAVORED
LOCATIONS SUCH AS KPSF/KGFL. WILL MENTION MVFR VSBYS FOR NOW AT
KALB/KPOU.
ADDITIONAL SHRA/TSRA ARE LIKELY ON THURSDAY AHEAD OF AND ALONG A
COLD FRONT PASSAGE. THE BEST CHANCE WILL BE FROM AROUND LATE MORNING
OR EARLY AFTERNOON INTO THE EVENING 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...JPV
FIRE WEATHER...JPV
HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1051 AM EDT TUE SEP 10 2013
.SYNOPSIS...
HIGH PRESSURE PUSHES EAST AS A WARM FRONT LIFTS NORTH THROUGH THE
NORTHEAST TODAY INTO TONIGHT. A COLD FRONT APPROACHES FROM THE
WEST WEDNESDAY INTO THURSDAY AND CROSSES THURSDAY NIGHT INTO
EARLY FRIDAY. CANADIAN HIGH PRESSURE BUILDS INTO THE REGION THIS
WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS AND THUNDERSTORMS CONTINUE TO APPROACH FROM THE
NORTH...AND SHOULD MOVE INTO ORANGE AND PUTNAM COUNTIES...AS WELL
AS INTERIOR PORTIONS OF SOUTHERN CT...WITHIN THE HOUR. LIGHTNING
ASSOCIATED WITH THESE STORMS HAVE DIMINISHED FAIRLY SIGNIFICANTLY
OVER THE LAST HOUR OR SO...AND WOULD EXPECT THAT TREND TO CONTINUE
AS THOSE STORMS TRACK TO THE SOUTHEAST.
BRIEF PERIOD OF LOCALLY HEAVY RAIN POSSIBLE...MAINLY FOR THE
INTERIOR ZONES AND FOR CT. LATEST HRRR HAS BEEN FAIRLY CONSISTENT
WITH ITS IMPACTING THOSE AREAS AND ITS CONTINUED WEAKENING INTO
THE EARLY AFTERNOON HOURS.
CONDITIONS EXPECTED TO DRY OUT BY THE AFTERNOON AS SUBSIDENCE
BUILDS IN ALOFT AND WARM FRONT MOVES NORTH.
TEMPS TODAY WELL ABOVE NORMAL...AND A GOOD 10 DEGREES WARMER THAN
YESTERDAY AS WE SEE THE WARM ADVECTION INCREASING 850MB TEMPS FROM
THE LOWER TEENS TO NEAR 20 DEGREES CELSIUS BY 00Z WED. DEPENDENT ON
HOW QUICKLY SKIES CLEAR...COULD SEE AN ADDITIONAL COUPLE DEGREES
ADDED TO FORECASTED HIGHS. FOR NOW WENT WITH BLEND OF MET/MAV WITH
EACH PROVIDING SIMILAR GUIDANCE.
THERE IS A MODERATE RIP CURRENT RISK AT THE OCEAN BEACHES TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
QUIET NIGHT IN STORE FOR THE TRI STATE WITH THE WARM FRONT QUICKLY
PUSHING TO THE NORTH AND THE ASSOCIATED LOW PRESSURE SYSTEM WELL TO
WEST. INCREASING SUBSIDENCE ALOFT SHOULD KEEP SKIES MAINLY
CLEAR...WITH INCREASING CLOUD COVERAGE BY EARLY TOMORROW MORNING. AN
INCREASING MOISTURE FIELD IN THE LOWER LEVELS COULD LEAD TO PATCHY
FOG DEVELOPMENT LATE IN THE NIGHT AS WELL...ESPECIALLY WITH WINDS
WEAKENING AFTER 06Z.
MAIN STORY FOR WEDNESDAY WILL BE THE WELL ABOVE NORMAL
TEMPERATURES...OVER 10 DEGREES ABOVE NORMAL AND SOME AREAS EVEN
NEARING RECORD HIGHS AS 850MB TEMPS SURGE INTO THE LOWER 20S. MUCH
BIGGER SPREAD IN TEMP GUIDANCE FOR HIGHS WED...AS THE MET PUSHES
TEMPS INTO THE LOWER 90S FOR MOST OF THE AREA. FEEL THIS MIGHT BE
A TAD TOO HIGH...SO SIDED WITH THE SLIGHTLY COOLER
SOLUTIONS...ESPECIALLY WITH INCREASING SKY COVERAGE AHEAD OF THE
APPROACHING COLD FRONT. HOWEVER...WITH DEW PTS ALSO PUSHING TO
AROUND 70...COULD STILL SEE A PERIOD WED AFTN WITH HEAT INDICES
REACHING INTO THE MID TO UPPER 90S OVER THE NYC METRO AREA AND
LOWER HUDSON RIVER VALLEY AND POSSIBLY EVEN REACHING THE CENTURY
MARK IN NYC. HOWEVER...CONFIDENCE IS NOT AS HIGH ON THIS BEING
ACCOMPLISHED...WITH THE BETTER CHANCE OF HEAT ADVISORY
CRITERIA...HI OF 95...BEING MET FOR A COUPLE OF HOURS. HIGH
CONFIDENCE OVERALL THOUGH OF A HOT AND HUMID DAY.
EXPECTING GENERALLY DRY CONDITIONS FOR THE FIRST PART OF WED...WITH
INCREASING POPS OVER AREAS WEST AND NORTH OF THE CITY BY LATE IN THE
DAY WITH INCREASING SURFACE BASED INSTABILITY AND AS THE UPPER LEVEL
TROUGH DEEPENS INTO THE NORTHEAST...PUSHING THROUGH MULTIPLE
SHORTWAVES. HOWEVER...THINKING THAT THE MAIN FORCING DURING THE DAY
WILL REMAIN NORTH OF THE AREA...WITH THE BETTER CHANCE FOR PRECIP
COMING WED NIGHT INTO THURSDAY. BECAUSE OF THE DEEP MOISTURE...ANY
THUNDERSTORM THAT DOES FORM COULD PRODUCE A QUICK HEAVY
RAINFALL...RESULTING IN MINOR FLOODING OF URBAN...AND POOR DRAINAGE
AREAS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MODELS IN GOOD AGREEMENT WITH A TROUGH DIGGING FROM THE GREAT LAKES
TOWARDS THE NORTHEAST WED NIGHT THROUGH THU NIGHT.
ANY CONVECTION ACROSS WESTERN ZONES WEDNESDAY EVENING SHOULD
DIMINISH IN INTENSITY...WITH MAINLY ISOLATED SHRA/TSRA POTENTIAL
OVERNIGHT ACROSS FAR NW ZONES IN VICINITY OF A PRE-FRONTAL TROUGH.
VERY WARM AND HUMID CONDITIONS CONTINUE FOR THU...BUT MORE IN THE
WAY OF CLOUD COVER SHOULD KEEP TEMPS MAINLY IN THE LOWER TO MID 80S.
UPPER 80S POSSIBLE ACROSS NYC/NJ METRO IF ANY EXTENDED SUNSHINE.
MODELS HAVE TRENDED A BIT SLOWER WITH THE UPPER TROUGH APPROACH ON
THU. IF THIS TREND HOLD...THIS WOULD RETARD THE DEVELOPMENT OF MORE
WIDESPREAD SHOWER AND TSTM ACTIVITY ALONG/AHEAD OF A PRE-FRONTAL
TROUGH. FOR NOW HAVE TRENDED FORECAST IN THIS DIRECTION...WITH
SCATTERED TO NUMEROUS SHRA/TSRA DEVELOPING ACROSS WESTERN ZONES
ALONG/AHEAD OF THE PRE-FRONTAL TROUGH THU AFTERNOON. ISOLATED
DEVELOPMENT POSSIBLE ALONG SEA BREEZE BOUNDARY AND HIGHER ELEVATION
ELSEWHERE. WOULD EXPECTED THE ACTIVITY TO GRADUALLY TRANSLATE EAST
IN THE EVENING AS THE COLD FRONT ENTERS AND CROSSES THE REGION.
THE SLOWER APPROACH OF THE TROUGH WOULD KEEP STRONGER SHEAR TO THE
WEST OF THE REGION UNTIL LATE IN THE DAY. THIS WOULD ALSO MEAN
WEAKER MID-LEVEL LAPSE RATES...WITH MODERATE DE-STABILIZATION
DEPENDENT ON AMOUNT OF SUNSHINE. THE WEAKER SHEAR AND WIND PROFILE
WOULD ALSO LEAN AGAINST STORM ORGANIZATION. IF THIS TREND
HOLDS...A FEW PULSE STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE
ACROSS THE NYC/NJ METRO AND INTERIOR WITH ENOUGH SUNSHINE...BUT
PROBABILITY FOR ORGANIZED SEVERE WEATHER IS LOW. THIS WILL HAVE TO
WATCHED THOUGH AS A SLIGHTLY QUICKER TROUGH APPROACH WOULD INCREASE
THE SEVERE THREAT. SEE HYDROLOGY SECTION FOR FLOODING THREAT.
WITH APPROACHING SYNOPTIC SUPPORT THU NIGHT...AT LEAST SCATTERED
SHOWERS AND ISOLATED TSTM ACTIVITY SHOULD TRANSLATE INTO EASTERN
ZONES AHEAD OF THE COLD FRONTAL PASSAGE. ANY SEVERE THREAT SHOULD
DIMINISH IN THE EVENING WITH WEAKENING SURFACE INSTABILITY.
THEREAFTER...MODELS HAVE SIMILARLY TRENDED SLOWER WITH THE PASSAGE
OF THE TROUGH FRIDAY INTO SATURDAY...AS A SHORTWAVE COMING DOWN THE
BACKSIDE OF THE TROUGH DIGS IT INTO THE NORTHEAST...AND PERHAPS EVEN
DEVELOPS A CUTOFF LOW. THERE IS STILL SOME UNCERTAINTY ON THE
EVOLUTION OF THIS TROUGH...WHICH WILL DEPEND ON THE STRENGTH OF THE
BACKSIDE SHORTWAVE. A SLOWER AND MORE NEUTRALLY TILTED TROUGH
PASSAGE WOULD MEAN A SLOWER COLD FRONTAL PASSAGE...WITH SHOWER
ACTIVITY PRESUMABLY LINGERING INTO FRIDAY MORNING OR EVEN AFTERNOON.
CONFIDENCE IS AT LEAST INCREASING IN INSTABILITY CU AND ISOLATED
SHRA ACTIVITY FRI AFTERNOON AS THE UPPER TROUGH MOVING OVER THE
REGION.
OTHERWISE...A COOL FALL TYPE WEEKEND IS FORECAST WITH TEMPERATURES
AVERAGING 5 TO 10 DEGREES BELOW NORMAL SATURDAY THROUGH SUNDAY. DAY
TIME HIGH TEMPERATURES ON SATURDAY SHOULD REMAIN IN THE 60S WITH AT
LEAST PARTIAL SUNSHINE. DEPENDING ON TROUGH EVOLUTION...SATURDAY
COULD BE COOLER THAN FORECAST WITH MORE IN THE WAY OF INSTABILITY CU
AND EVEN A FEW SHOWERS N AND E.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
WARM FRONT LIFTS ACROSS THE AREA DURING THE FIRST HALF OF THE DAY.
MVFR CIGS TO PERSIST THROUGH 17-18Z...AND THEN SCATTER OUT. EASTERN
TERMINALS MAY HOLD ONTO MVFR CIGS UNTIL 19Z.
WINDS FROM S-SW PICK UP TO 10-15 KT SUSTAINED THRU LATE MORNING/EARLY
AFTERNOON WITH GUSTS AFTER 18Z UP TO 20 KT OR SO. OCCASIONAL GUSTS
PRIOR TO 18Z.
RAIN/SHOWERS EXPECTED TO REACH THE TERMINALS NORTH OF NYC. LOWER
CHANCE OF RAIN REACHING THE NYC TERMINAL. LOW POTENTIAL FOR ANY
THUNDER TO MAKE IT...ESPECIALLY TO THE CITY TERMINALS.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: TIMING OF END OF MVFR CIGS MAY BE OFF BY 1-2
HRS FROM FORECAST. GUSTS COULD BE A FEW KT HIGHER THAN FORECAST.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: TIMING OF END OF MVFR CIGS MAY BE OFF BY 1-2
HRS FROM FORECAST. GUSTS COULD BE A FEW KT HIGHER THAN FORECAST.
KLGA FCSTER COMMENTS: TIMING OF END OF MVFR CIGS MAY BE OFF BY 1-2
HRS FROM FORECAST. GUSTS COULD BE A FEW KT HIGHER THAN FORECAST.
KTEB FCSTER COMMENTS: TIMING OF END OF MVFR CIGS MAY BE OFF BY 1-2
HRS FROM FORECAST. GUSTS COULD BE MORE OCCASIONAL THAN FREQUENT
TODAY.
KHPN FCSTER COMMENTS: TIMING OF END OF MVFR CIGS MAY BE OFF BY
1-2 HRS FROM FORECAST.
KISP FCSTER COMMENTS: TIMING OF END OF MVFR CIGS MAY BE OFF BY 1-2
HRS FROM FORECAST. GUSTS COULD BE A FEW KT HIGHER THAN FORECAST.
OUTLOOK FOR 12Z WED THROUGH SAT...
.TUE NIGHT...PSBL MVFR/IFR VSBYS IN AREAS OF FOG THROUGH MORNING.
.WED-WED NIGHT...GENERALLY VFR WITH PSBL MVFR LATE IN THE DAY WITH
ISO-SCT PCPN AHEAD OF APPROACHING COLD FRONT. REDUCED CIGS/VIS
OVERNIGHT.
.THU...SCT SHOWERS/TSTMS WITH OCNL MVFR OR LOWER CONDS. COLD
FROPA LATE THU NIGHT.
.FRI...VFR. NW GUSTS 15-20 KTS PSBL IN THE AFTN.
.SAT...VFR. NW GUSTS 15-20 KTS PSBL IN THE AFTN.
&&
.MARINE...
OCCASIONAL GUSTS TO 25 KTS POSSIBLE ON THE OCEAN WATERS AND LONG
ISLAND BAYS TODAY WITH INCREASING ONSHORE FLOW. HOWEVER...
EXPECTING WINDS TO DIMINISH TONIGHT WITH THE FRONTAL PASSAGE...AND
WITH SUB-SCA CONDITIONS THEN REMAINING IN PLACE FOR ALL WATERS
THROUGH WED AS HIGH PRESSURE REMAINS ANCHORED OFFSHORE TO THE
EAST. SEAS INCREASE AS WELL WITH THE INCREASED WIND FLOW...BUT ARE
EXPECTED TO REMAIN BELOW 5 FT.
A STRENGTHENING S/SW FLOW LIKELY AHEAD OF AN APPROACHING COLD FRONT
WEDNESDAY NIGHT INTO THURSDAY. MARGINAL SCA GUSTS ARE POSSIBLE ON
THE OCEAN WATERS THU. THIS FLOW COULD HAVE SEAS BUILD TO AROUND 5 FT
LATE THU INTO THU NIGHT.
THE COLD FRONT CROSSES THE WATERS THURSDAY NIGHT THEN HIGH PRESSURE
BUILDS OVER THE WATERS FOR FRIDAY AND FRIDAY NIGHT. A PERIOD OF
MARGINAL SCA GUSTS POSSIBLE WITH STRONGEST CAA LATE FRI/FRI EVENING.
OFFSHORE FLOW SHOULD HAVE SEAS SUBSIDING BELOW SCA ON FRI.
AT THIS POINT IT APPEARS THAT SWELL CONTRIBUTIONS FROM TROPICAL
STORM GABRIELLE WILL BE SMALL...1 TO 2 FT LONG PERIOD ESE SWELLS
FOR FROM LATE WEEK INTO WEEKEND. REFER TO THE NATIONAL HURRICANE
CENTER FOR THE LATEST ON GABRIELLE.
SUB SCA CONDS EXPECTED FOR THE WEEKEND INTO EARLY NEXT WEEK AS HIGH
PRESSURE BUILDS INTO THE REGION.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH WEDNESDAY NIGHT.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS EXPECTED THU
AFTERNOON THROUGH THURSDAY EVENING. MINOR URBAN AND POOR DRAINAGE
FLOODING IS THE PRIMARY THREAT...WITH A LOCALIZED FLASH FLOOD THREAT
WITH ANY TRAINING ACTIVITY.
ON AVERAGE WED NIGHT THRU THU NIGHT...A THIRD TO ONE INCH OF
RAINFALL IS POSSIBLE. THE HIGHEST AMOUNTS WILL LIKELY BE ACROSS
NORTHERN AND WESTERN ZONES.
&&
.CLIMATE...
WEDNESDAY IS FORECASTED TO BE THE WARMEST DAY THIS WEEK...WITH
HIGH TEMPERATURES PUSHING WELL ABOVE NORMAL. WHILE MOST OF THE
AREA IS FORECASTED TO HAVE HIGHS REMAIN A FEW DEGREES BELOW RECORD
VALUES...THESE TEMPS COMBINED WITH A VERY MOIST AIRMASS WILL
RESULT IN A HOT...UNSEASONABLE DAY.
LISTED BELOW ARE THE RECORD HIGHS AND THE FORECASTED HIGHS FOR
WEDNESDAY FOR EACH OF OUR 6 CLIMATE SITES.
SITE RECORD TEMPFORECASTED TEMP
------------------------------
BDR 90 (1983) 87
EWR 99 (1983) 93
ISP 88 (1989) 87
JFK 96 (1983) 88
LGA 96 (1983) 90
NYC 99 (1983)91
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY
BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER
RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL WEATHER
SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES TO
ISOLATE AND RESOLVE THE TECHNICAL PROBLEM.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO
DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SEARS/NV
NEAR TERM...SEARS/MPS
SHORT TERM...SEARS
LONG TERM...NV
AVIATION...BC/PICCA
MARINE...SEARS/NV
HYDROLOGY...SEARS/NV
CLIMATE...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1035 AM EDT TUE SEP 10 2013
.SYNOPSIS...
HIGH PRESSURE PUSHES EAST AS A WARM FRONT LIFTS NORTH THROUGH THE
NORTHEAST TODAY INTO TONIGHT. A COLD FRONT APPROACHES FROM THE
WEST WEDNESDAY INTO THURSDAY AND CROSSES THURSDAY NIGHT INTO
EARLY FRIDAY. CANADIAN HIGH PRESSURE BUILDS INTO THE REGION THIS
WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS AND THUNDERSTORMS CONTINUE TO APPROACH FROM THE
NORTH...AND SHOULD MOVE INTO ORANGE AND PUTNAM COUNTIES...AS WELL
AS INTERIOR PORTIONS OF SOUTHERN CT...WITHIN THE HOUR. LIGHTNING
ASSOCIATED WITH THESE STORMS HAVE DIMINISHED FAIRLY SIGNIFICANTLY
OVER THE LAST HOUR OR SO...AND WOULD EXPECT THAT TREND TO CONTINUE
AS THOSE STORMS TRACK TO THE SOUTHEAST.
BRIEF PERIOD OF LOCALLY HEAVY RAIN POSSIBLE...MAINLY FOR THE
INTERIOR ZONES AND FOR CT. LATEST HRRR HAS BEEN FAIRLY CONSISTENT
WITH ITS IMPACTING THOSE AREAS AND ITS CONTINUED WEAKENING INTO
THE EARLY AFTERNOON HOURS.
CONDITIONS EXPECTED TO DRY OUT BY THE AFTERNOON AS SUBSIDENCE
BUILDS IN ALOFT AND WARM FRONT MOVES NORTH.
TEMPS TODAY WELL ABOVE NORMAL...AND A GOOD 10 DEGREES WARMER THAN
YESTERDAY AS WE SEE THE WARM ADVECTION INCREASING 850MB TEMPS FROM
THE LOWER TEENS TO NEAR 20 DEGREES CELSIUS BY 00Z WED. DEPENDENT ON
HOW QUICKLY SKIES CLEAR...COULD SEE AN ADDITIONAL COUPLE DEGREES
ADDED TO FORECASTED HIGHS. FOR NOW WENT WITH BLEND OF MET/MAV WITH
EACH PROVIDING SIMILAR GUIDANCE.
THERE IS A MODERATE RIP CURRENT RISK AT THE OCEAN BEACHES TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
QUIET NIGHT IN STORE FOR THE TRI STATE WITH THE WARM FRONT QUICKLY
PUSHING TO THE NORTH AND THE ASSOCIATED LOW PRESSURE SYSTEM WELL TO
WEST. INCREASING SUBSIDENCE ALOFT SHOULD KEEP SKIES MAINLY
CLEAR...WITH INCREASING CLOUD COVERAGE BY EARLY TOMORROW MORNING. AN
INCREASING MOISTURE FIELD IN THE LOWER LEVELS COULD LEAD TO PATCHY
FOG DEVELOPMENT LATE IN THE NIGHT AS WELL...ESPECIALLY WITH WINDS
WEAKENING AFTER 06Z.
MAIN STORY FOR WEDNESDAY WILL BE THE WELL ABOVE NORMAL
TEMPERATURES...OVER 10 DEGREES ABOVE NORMAL AND SOME AREAS EVEN
NEARING RECORD HIGHS AS 850MB TEMPS SURGE INTO THE LOWER 20S. MUCH
BIGGER SPREAD IN TEMP GUIDANCE FOR HIGHS WED...AS THE MET PUSHES
TEMPS INTO THE LOWER 90S FOR MOST OF THE AREA. FEEL THIS MIGHT BE
A TAD TOO HIGH...SO SIDED WITH THE SLIGHTLY COOLER
SOLUTIONS...ESPECIALLY WITH INCREASING SKY COVERAGE AHEAD OF THE
APPROACHING COLD FRONT. HOWEVER...WITH DEW PTS ALSO PUSHING TO
AROUND 70...COULD STILL SEE A PERIOD WED AFTN WITH HEAT INDICES
REACHING INTO THE MID TO UPPER 90S OVER THE NYC METRO AREA AND
LOWER HUDSON RIVER VALLEY AND POSSIBLY EVEN REACHING THE CENTURY
MARK IN NYC. HOWEVER...CONFIDENCE IS NOT AS HIGH ON THIS BEING
ACCOMPLISHED...WITH THE BETTER CHANCE OF HEAT ADVISORY
CRITERIA...HI OF 95...BEING MET FOR A COUPLE OF HOURS. HIGH
CONFIDENCE OVERALL THOUGH OF A HOT AND HUMID DAY.
EXPECTING GENERALLY DRY CONDITIONS FOR THE FIRST PART OF WED...WITH
INCREASING POPS OVER AREAS WEST AND NORTH OF THE CITY BY LATE IN THE
DAY WITH INCREASING SURFACE BASED INSTABILITY AND AS THE UPPER LEVEL
TROUGH DEEPENS INTO THE NORTHEAST...PUSHING THROUGH MULTIPLE
SHORTWAVES. HOWEVER...THINKING THAT THE MAIN FORCING DURING THE DAY
WILL REMAIN NORTH OF THE AREA...WITH THE BETTER CHANCE FOR PRECIP
COMING WED NIGHT INTO THURSDAY. BECAUSE OF THE DEEP MOISTURE...ANY
THUNDERSTORM THAT DOES FORM COULD PRODUCE A QUICK HEAVY
RAINFALL...RESULTING IN MINOR FLOODING OF URBAN...AND POOR DRAINAGE
AREAS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MODELS IN GOOD AGREEMENT WITH A TROUGH DIGGING FROM THE GREAT LAKES
TOWARDS THE NORTHEAST WED NIGHT THROUGH THU NIGHT.
ANY CONVECTION ACROSS WESTERN ZONES WEDNESDAY EVENING SHOULD
DIMINISH IN INTENSITY...WITH MAINLY ISOLATED SHRA/TSRA POTENTIAL
OVERNIGHT ACROSS FAR NW ZONES IN VICINITY OF A PRE-FRONTAL TROUGH.
VERY WARM AND HUMID CONDITIONS CONTINUE FOR THU...BUT MORE IN THE
WAY OF CLOUD COVER SHOULD KEEP TEMPS MAINLY IN THE LOWER TO MID 80S.
UPPER 80S POSSIBLE ACROSS NYC/NJ METRO IF ANY EXTENDED SUNSHINE.
MODELS HAVE TRENDED A BIT SLOWER WITH THE UPPER TROUGH APPROACH ON
THU. IF THIS TREND HOLD...THIS WOULD RETARD THE DEVELOPMENT OF MORE
WIDESPREAD SHOWER AND TSTM ACTIVITY ALONG/AHEAD OF A PRE-FRONTAL
TROUGH. FOR NOW HAVE TRENDED FORECAST IN THIS DIRECTION...WITH
SCATTERED TO NUMEROUS SHRA/TSRA DEVELOPING ACROSS WESTERN ZONES
ALONG/AHEAD OF THE PRE-FRONTAL TROUGH THU AFTERNOON. ISOLATED
DEVELOPMENT POSSIBLE ALONG SEA BREEZE BOUNDARY AND HIGHER ELEVATION
ELSEWHERE. WOULD EXPECTED THE ACTIVITY TO GRADUALLY TRANSLATE EAST
IN THE EVENING AS THE COLD FRONT ENTERS AND CROSSES THE REGION.
THE SLOWER APPROACH OF THE TROUGH WOULD KEEP STRONGER SHEAR TO THE
WEST OF THE REGION UNTIL LATE IN THE DAY. THIS WOULD ALSO MEAN
WEAKER MID-LEVEL LAPSE RATES...WITH MODERATE DE-STABILIZATION
DEPENDENT ON AMOUNT OF SUNSHINE. THE WEAKER SHEAR AND WIND PROFILE
WOULD ALSO LEAN AGAINST STORM ORGANIZATION. IF THIS TREND
HOLDS...A FEW PULSE STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE
ACROSS THE NYC/NJ METRO AND INTERIOR WITH ENOUGH SUNSHINE...BUT
PROBABILITY FOR ORGANIZED SEVERE WEATHER IS LOW. THIS WILL HAVE TO
WATCHED THOUGH AS A SLIGHTLY QUICKER TROUGH APPROACH WOULD INCREASE
THE SEVERE THREAT. SEE HYDROLOGY SECTION FOR FLOODING THREAT.
WITH APPROACHING SYNOPTIC SUPPORT THU NIGHT...AT LEAST SCATTERED
SHOWERS AND ISOLATED TSTM ACTIVITY SHOULD TRANSLATE INTO EASTERN
ZONES AHEAD OF THE COLD FRONTAL PASSAGE. ANY SEVERE THREAT SHOULD
DIMINISH IN THE EVENING WITH WEAKENING SURFACE INSTABILITY.
THEREAFTER...MODELS HAVE SIMILARLY TRENDED SLOWER WITH THE PASSAGE
OF THE TROUGH FRIDAY INTO SATURDAY...AS A SHORTWAVE COMING DOWN THE
BACKSIDE OF THE TROUGH DIGS IT INTO THE NORTHEAST...AND PERHAPS EVEN
DEVELOPS A CUTOFF LOW. THERE IS STILL SOME UNCERTAINTY ON THE
EVOLUTION OF THIS TROUGH...WHICH WILL DEPEND ON THE STRENGTH OF THE
BACKSIDE SHORTWAVE. A SLOWER AND MORE NEUTRALLY TILTED TROUGH
PASSAGE WOULD MEAN A SLOWER COLD FRONTAL PASSAGE...WITH SHOWER
ACTIVITY PRESUMABLY LINGERING INTO FRIDAY MORNING OR EVEN AFTERNOON.
CONFIDENCE IS AT LEAST INCREASING IN INSTABILITY CU AND ISOLATED
SHRA ACTIVITY FRI AFTERNOON AS THE UPPER TROUGH MOVING OVER THE
REGION.
OTHERWISE...A COOL FALL TYPE WEEKEND IS FORECAST WITH TEMPERATURES
AVERAGING 5 TO 10 DEGREES BELOW NORMAL SATURDAY THROUGH SUNDAY. DAY
TIME HIGH TEMPERATURES ON SATURDAY SHOULD REMAIN IN THE 60S WITH AT
LEAST PARTIAL SUNSHINE. DEPENDING ON TROUGH EVOLUTION...SATURDAY
COULD BE COOLER THAN FORECAST WITH MORE IN THE WAY OF INSTABILITY CU
AND EVEN A FEW SHOWERS N AND E.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
WARM FRONT LIFTS ACROSS THE AREA DURING THE FIRST HALF OF THE DAY.
MVFR CIGS TO PERSIST THROUGH 15-16Z...AND THEN SCATTER OUT. LOW
POTENTIAL FOR KEWR/KTEB/KHPN/KSWF TO SEE BRIEF IFR CIGS OVER NEXT
COUPLE OF HOURS. EASTERN TERMINALS MAY HOLD ONTO MVFR CIGS UNTIL
17-18Z.
WINDS FROM S-SW PICK UP TO 10-15 KT SUSTAINED THRU LATE MORNING /
EARLY AFTERNOON WITH GUSTS UP TO 20 KT OR SO. OCCASIONAL GUSTS
PRIOR TO 15-16Z.
SOME POTENTIAL FOR SHOWERS FROM UPSTATE COMPLEX TO REACH NW
TERMINALS THIS AFTERNOON. LOW POTENTIAL FOR ANY THUNDER TO MAKE
IT...ESPECIALLY TO THE CITY TERMINALS. THEREFORE...NO MENTION IN
TAFS.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: TIMING OF END OF MVFR CIGS MAY BE OFF BY 1-2
HRS FROM FORECAST. GUSTS COULD BE A FEW KT HIGHER THAN FORECAST.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: TIMING OF END OF MVFR CIGS MAY BE OFF BY 1-2
HRS FROM FORECAST. GUSTS COULD BE A FEW KT HIGHER THAN FORECAST.
KLGA FCSTER COMMENTS: TIMING OF END OF MVFR CIGS MAY BE OFF BY 1-2
HRS FROM FORECAST. GUSTS COULD BE A FEW KT HIGHER THAN FORECAST.
KTEB FCSTER COMMENTS: TIMING OF END OF MVFR CIGS MAY BE OFF BY 1-2
HRS FROM FORECAST. GUSTS COULD BE MORE OCCASIONAL THAN FREQUENT
TODAY.
KHPN FCSTER COMMENTS: TIMING OF END OF MVFR CIGS MAY BE OFF BY
1-2 HRS FROM FORECAST.
KISP FCSTER COMMENTS: TIMING OF END OF MVFR CIGS MAY BE OFF BY 1-2
HRS FROM FORECAST. GUSTS COULD BE A FEW KT HIGHER THAN FORECAST.
OUTLOOK FOR 12Z WED THROUGH SAT...
.TUE NIGHT...PSBL MVFR/IFR VSBYS IN AREAS OF FOG THROUGH MORNING.
.WED-WED NIGHT...GENERALLY VFR WITH PSBL MVFR LATE IN THE DAY WITH
ISO-SCT PCPN AHEAD OF APPROACHING COLD FRONT. REDUCED CIGS/VIS
OVERNIGHT.
.THU...SCT SHOWERS/TSTMS WITH OCNL MVFR OR LOWER CONDS. COLD
FROPA LATE THU NIGHT.
.FRI...VFR. NW GUSTS 15-20 KTS PSBL IN THE AFTN.
.SAT...VFR. NW GUSTS 15-20 KTS PSBL IN THE AFTN.
&&
.MARINE...
OCCASIONAL GUSTS TO 25 KTS POSSIBLE ON THE OCEAN WATERS AND LONG
ISLAND BAYS TODAY WITH INCREASING ONSHORE FLOW. HOWEVER...
EXPECTING WINDS TO DIMINISH TONIGHT WITH THE FRONTAL PASSAGE...AND
WITH SUB-SCA CONDITIONS THEN REMAINING IN PLACE FOR ALL WATERS
THROUGH WED AS HIGH PRESSURE REMAINS ANCHORED OFFSHORE TO THE
EAST. SEAS INCREASE AS WELL WITH THE INCREASED WIND FLOW...BUT ARE
EXPECTED TO REMAIN BELOW 5 FT.
A STRENGTHENING S/SW FLOW LIKELY AHEAD OF AN APPROACHING COLD FRONT
WEDNESDAY NIGHT INTO THURSDAY. MARGINAL SCA GUSTS ARE POSSIBLE ON
THE OCEAN WATERS THU. THIS FLOW COULD HAVE SEAS BUILD TO AROUND 5 FT
LATE THU INTO THU NIGHT.
THE COLD FRONT CROSSES THE WATERS THURSDAY NIGHT THEN HIGH PRESSURE
BUILDS OVER THE WATERS FOR FRIDAY AND FRIDAY NIGHT. A PERIOD OF
MARGINAL SCA GUSTS POSSIBLE WITH STRONGEST CAA LATE FRI/FRI EVENING.
OFFSHORE FLOW SHOULD HAVE SEAS SUBSIDING BELOW SCA ON FRI.
AT THIS POINT IT APPEARS THAT SWELL CONTRIBUTIONS FROM TROPICAL
STORM GABRIELLE WILL BE SMALL...1 TO 2 FT LONG PERIOD ESE SWELLS
FOR FROM LATE WEEK INTO WEEKEND. REFER TO THE NATIONAL HURRICANE
CENTER FOR THE LATEST ON GABRIELLE.
SUB SCA CONDS EXPECTED FOR THE WEEKEND INTO EARLY NEXT WEEK AS HIGH
PRESSURE BUILDS INTO THE REGION.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH WEDNESDAY NIGHT.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS EXPECTED THU
AFTERNOON THROUGH THURSDAY EVENING. MINOR URBAN AND POOR DRAINAGE
FLOODING IS THE PRIMARY THREAT...WITH A LOCALIZED FLASH FLOOD THREAT
WITH ANY TRAINING ACTIVITY.
ON AVERAGE WED NIGHT THRU THU NIGHT...A THIRD TO ONE INCH OF
RAINFALL IS POSSIBLE. THE HIGHEST AMOUNTS WILL LIKELY BE ACROSS
NORTHERN AND WESTERN ZONES.
&&
.CLIMATE...
WEDNESDAY IS FORECASTED TO BE THE WARMEST DAY THIS WEEK...WITH
HIGH TEMPERATURES PUSHING WELL ABOVE NORMAL. WHILE MOST OF THE
AREA IS FORECASTED TO HAVE HIGHS REMAIN A FEW DEGREES BELOW RECORD
VALUES...THESE TEMPS COMBINED WITH A VERY MOIST AIRMASS WILL
RESULT IN A HOT...UNSEASONABLE DAY.
LISTED BELOW ARE THE RECORD HIGHS AND THE FORECASTED HIGHS FOR
WEDNESDAY FOR EACH OF OUR 6 CLIMATE SITES.
SITE RECORD TEMPFORECASTED TEMP
------------------------------
BDR 90 (1983) 87
EWR 99 (1983) 93
ISP 88 (1989) 87
JFK 96 (1983) 88
LGA 96 (1983) 90
NYC 99 (1983)91
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY
BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER
RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL WEATHER
SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES TO
ISOLATE AND RESOLVE THE TECHNICAL PROBLEM.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO
DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SEARS/NV
NEAR TERM...SEARS/MPS
SHORT TERM...SEARS
LONG TERM...NV
AVIATION...PICCA
MARINE...SEARS/NV
HYDROLOGY...SEARS/NV
CLIMATE...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1032 AM EDT TUE SEP 10 2013
.SYNOPSIS...
AN APPROACHING WARM FRONT WILL BRING CLOUDS ACROSS THE REGION
ALONG WITH THE CHANCE OF A FEW SHOWERS THIS MORNING. THE FRONT
WILL LIFT THROUGH THE REGION LATE TODAY AND TONIGHT...BRINGING
VERY WARM AND MORE HUMID WEATHER FOR MID WEEK. A COLD FRONT WILL
LIKELY BRING SHOWERS AND THUNDERSTORMS WITH GUSTY WINDS AND HEAVY
RAIN THURSDAY AND THURSDAY NIGHT. HIGH PRESSURE RETURNS FOR NEXT
WEEKEND WITH DRY AND MUCH COOLER WEATHER.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1030 AM UPDATE...
CONVECTIVE COMPLEX ENTERING WESTERN NEW ENGLAND CONTINUES TO SHOW
SLOW WEAKENING WITH TIME AS IT OUT RUNS BETTER INSTABILITY ALOFT
WESTWARD ACROSS NY STATE AND THE GREAT LAKES. HOWEVER THESE STORMS
WILL CONTAIN BRIEF HEAVY RAIN AND LIGHTNING. AS FOR WINDS...SOUTHERN
NEW ENGLAND REMAINS ON THE COOL SIDE OF THE BOUNDARY SO STABLE LOW
LEVELS SHOULD PRECLUDE STRONGER WINDS ALOFT FROM MIXING DOWNWARD
TO THE SURFACE.
ONLY THE HRRR IS CAPTURING THE EVOLUTION OF THIS CONVECTIVE
COMPLEX. THUS THIS FORECAST UPDATE IS HEAVILY BASED ON THE TIMING
FROM THE PAST FEW RUNS OF THE HRRR. SHOWERS AND TSTMS WILL RACE
ACROSS THE ENTIRE REGION AND MAKE IT ALL THE WAY TO THE CAPE
/ALBEIT IN A WEAKEN STATE/ AROUND 19Z AND THEN OFFSHORE 21Z- 23Z.
COULD SEE SOME LATE DAY SUNSHINE ACROSS WESTERN AREAS BUT TRUE
WARM SECTOR WILL NOT OVERSPREAD THE REGION UNTIL TONIGHT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TONIGHT...
WARM SECTOR WORKS IN FULL FORCE TONIGHT WITH A WARM...SULTRY NIGHT
IN PLACE ACROSS THE REGION. EXPECT PATCHY FOG TO DEVELOP...SOME OF
WHICH WILL BE LOCALLY DENSE ALONG THE COAST WITH HIGH DEWPTS IN
PLACE. H5 RIDGING BUILDS ACROSS THOUGH TENDS TO FLATTEN
OVERNIGHT. NOT EXPECTING ANY PRECIP THANKS TO H5 RIDGING THAT
BUILDS ACROSS...THOUGH TENDS TO FLATTEN OVERNIGHT. LOWS WILL BE IN
THE MID 60S TO LOWER 70S...MILDEST ALONG THE COAST AND URBAN
CENTERS.
WEDNESDAY...
HARD TO IGNORE SHORT RANGE MODELS WITH RATHER STRONG CONVECTIVE
SIGNALS WHICH HAVE CARRIED ON FOR SEVERAL MODEL RUNS NOW. NOTING A
WEAK TROUGH LINGERING ACROSS THE REGION AT THE SURFACE...BUT BULK
OF PRECIP WILL REMAIN WELL NW OF THE REGION WITH THE COLD FRONT
WORKING OUT OF SOUTHERN CANADA. LOOKS LIKE THIS TROUGHING WILL BE
THE FOCUS OF ANY SHOWERS/TSTMS THAT DEVELOP DURING THE
AFTERNOON/EVENING HOURS. GOOD LAPSE RATES TO MOVE IN ACROSS THE
REGION...ON ORDER OF 6.5 TO 7C/KM WITH MARGINAL SW SHEAR AT 20-25
KT. BETTER JET DYNAMICS REMAIN ACROSS CENTRAL AND NORTHERN NEW
ENGLAND. BIG ISSUE WITH ALL THIS WILL BE WHETHER LOW CLOUDS/FOG
BREAK TO ALLOW FOR MIXING AND BREAKING THE CAPPING IN PLACE WITH
RATHER HIGH CIN IN PLACE.
FEEL THERE WILL BE A CHANCE FOR SHOWERS/TSTMS MAINLY FROM NEAR
KLWM-KBED-KHFD N AND W DURING THE AFTERNOON. DID NOT USE ENHANCED
WORDING YET...BUT COULD SEE SOME HEAVY RAINFALL WITH SOME OF THESE
STORMS AS PWATS INCREASE TO 1.5 TO 1.75 INCHES. THIS WILL NEED TO
BE WATCHED CAREFULLY THOUGH...AS SOME OF THE INSTABILITY
PARAMETERS ARE IMPRESSIVE INCLUDING CAPES UP TO 2400 J/KG AND
TOTAL TOTALS IN THE LOWER-MID 50S AS SEEN ON THE 00Z GFS...NOT TOO
FAR FROM THAT ON THE 12Z ECWMF.
WILL BE A VERY WARM AND HUMID DAY WITH DEWPTS IN THE LOWER 70S.
HIGHS WILL BE IN THE LOWER 90S WELL INLAND...HOLDING IN THE UPPER
70S- MID 80S ALONG THE S COAST...CAPE COD AND THE ISLANDS. ONE
MORE ASPECT...IT IS MARGINAL AT THIS POINT BUT MAY NEED TO
CONSIDER HEAT ADVISORY IF TEMPS GO HIGHER THAN LOWER 90S. NO
RECORDS APPEAR TO BE THREATENED AS THE 9/11 RECORD HIGHS APPEAR TO
BE THE HIGHEST FOR THE MONTH OF SEPTEMBER. PLEASE SEE LIST IN THE
CLIMATE SECTION.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
BIG PICTURE...
SUBTROPICAL HIGH BUILDS THROUGH THE WESTERN USA WHILE A TROUGH
DIGS OVER THE NORTHEAST. THE WESTERN HIGH BREAKS DOWN BY THE
WEEKEND. THE ECMWF AND GFS BOTH TRY TO FORM A CUTOFF LOW OVER NEW
ENGLAND DURING THE WEEKEND...BUT THEY JUST AS QUICKLY MOVE THE LOW
OFF THROUGH THE MARITIMES ON SUNDAY. SHORTWAVE FROM NORTHERN
CANADA SWEEPS SOUTH AND REACHES NEW ENGLAND EARLY NEXT WEEK. THIS
WILL MAINTAIN THE EASTERN TROUGH.
THE GFS AND ECMWF MASS FIELDS ARE SIMILAR THROUGH SUNDAY...WITH
EMERGING DIFFERENCES WITH THE CANADIAN SHORTWAVE ON MONDAY. THE
FORECAST USES A BLEND OF LONG RANGE GUIDANCE.
THE DAILIES...
WEDNESDAY NIGHT...GFS AND GGEM SHOW A GOOD UPPER DIVERGENCE/LOW
LEVEL CONVERGENCE COUPLET OVER CT-RI-SE MASS AT 00Z. THE REMAINING
MODELS ARE LESS CLEAR ON THIS POINT. FAVORABLE MID LEVEL LAPSE
RATES OF AROUND 7C/KM LINGER THROUGH THE FIRST PART OF THE NIGHT.
TOTALS IN THE LOWER 50S. SURFACE BASED CAPES 1000-2000J/KG DURING
THE FIRST PART OF THE NIGHT...MAINLY SRN NH AND NORTHWEST MASS.
PRECIPITABLE WATER VALUES BETWEEN 1.5 AND 2.0.
EXPECT A LINGERING CHANCE OF TSTMS ESPECIALLY ACROSS SOUTHERN NH AND
WESTERN/CENTRAL MASS. COULD BE SOME HEAVY DOWNPOURS WITH ANY TSTMS.
A MILD MUGGY NIGHT WITH MIN TEMPS AROUND 70 AS PER MOS.
THURSDAY... TROUGH DIGGING OVER THE GREAT LAKES PUSHES A COLD FRONT
INTO THE WARM HUMID AIRMASS OVER NEW ENGLAND. SEVERAL FEATURES OF
INTEREST INCLUDING FAVORABLE INSTABILITY AND AN APPROACHING RIGHT
ENTRANCE REGION OF THE UPPER JET. HIGH PW VALUES LINGER. WINDS
ALOFT BECOME MORE FAVORABLE WITH 20-30 KNOTS AT 850 MB AND 40 KNOTS
AT 500 MB. THIS POINTS TO POTENTIAL FOR STRONG CONVECTION WITH THE
BEST CHANCE IN SOUTHWEST NH AND NORTHWEST MASS. HEAVY DOWNPOURS AND
LOCAL POOR DRAINAGE FLOODING ALSO LOOK POSSIBLE. SUFFICIENT FACTORS
EXIST TO SUPPORT LIKELY POPS FOR SHOWERS/TSTMS.
HIGH TEMPS WILL DEPEND ON THE AMOUNT OF SUNSHINE THAT WE GET THAT
DAY...SIGNIFICANT CLOUD DEBRIS FROM UPSTREAM CONVECTION WOULD HOLD
DOWN THE HEATING. HIGH DEWPOINTS SHOULD START THE MORNING AROUND 70.
MIXING TO 850 MB WOULD SUPPORT MAX TEMPS IN THE 80S. SUCH MIXING
WOULD ALSO BRING SOUTHWEST WINDS OF 20-25 KNOTS TO THE SURFACE.
CONSENSUS ON FRONTAL PASSAGE BRINGS IT THROUGH NEW ENGLAND DURING
THURSDAY NIGHT. EXPECT THE CHANCE OF SHOWERS TO DIMINISH AFTER FROPA
WITH WINDS TURNING NORTHWEST.
FRIDAY... QUESTION MARK FOR FRIDAY WILL BE THE AMOUNT OF CLOUDS THAT
LINGER OVER THE REGION. THE APPROACHING TROUGH AND ITS ASSOCIATED
JET MAY BE ABLE TO GENERATE A WAVE ALONG THE DEPARTING COLD FRONT.
THIS WOULD KEEP CLOUDS/SHOWERS OVER AT LEAST A PART OF OUR AREA...RI
AND EASTERN MASS WOULD BE MOST AT RISK. MEANWHILE THE APPROACHING
COLD POOL ALOFT WOULD SERVE TO DESTABILIZE THE AIRMASS AND PROMOTE
DIURNAL CLOUDS AND POSSIBLY A SHOWER. SO IF ONE DOESN/T GET US
PERHAPS THE OTHER WILL? THE FORECAST SHOWS A MIX OF CLOUDS AND SUN
WITH DEPARTING SHOWERS OFF THE EAST COAST AND ARRIVING SHOWERS OVER
THE NORTHERN INTERIOR.
SATURDAY-SUNDAY... HIGH PRESSURE BUILDS IN AT THE SURFACE WHILE THE
UPPER LOW TWIRLS OVERHEAD. EXPECT SOME CLOUDS AND WIDELY SCATTERED
SHOWERS ESPECIALLY ON SATURDAY AND ESPECIALLY OVER SOUTHERN
NH/NORTHERN MASS. TEMPS AT 850 MB WILL BE 2-4C SATURDAY AND 6-9C ON
SUNDAY. SO MAX TEMPS SATURDAY SHOULD BE IN THE 60S AND WITH WARMER
TEMPS ON SUNDAY.
MONDAY... COLD FRONT DRIVES SOUTH FROM CANADA. THE ECMWF SHOWS
CLOUDS AND SHOWERS...THE GFS HAS A PERIOD OF CLOUDS BUT DIMINISHES
THE SHOWERS AS THE FRONT MOVES INTO NEW ENGLAND. NOT MUCH CONFIDENCE
IN THE OCCURRENCE OF SHOWERS SO WE HELD AT SLIGHT CHANCE.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
OVERVIEW /THROUGH WEDNESDAY/...MODERATE CONFIDENCE THIS MORNING...
THEN LOWER CONFIDENCE THIS AFTERNOON THROUGH WEDNESDAY.
1030 AM UPDATE...
TSTMS OVER WESTERN NEW ENGLAND WILL CONTINUE TO SLOWLY WEAKEN
BUT SHOULD HOLD TOGETHER AND MOVE ACROSS THE ENTIRE REGION
REACHING BOSTON AROUND 16Z AND PROVIDENCE 17Z-18Z THEN TO CAPE COD
AND THE ISLANDS 19Z-21Z AND FINALLY OFFSHORE BY 23Z. STRONG WINDS
ALOFT WILL LIKELY NOT REACH THE SURFACE GIVEN COOL/STABLE LOW
LEVELS. MAIN THREATS HEAVY RAIN AND LIGHTNING.
--------------------------------------------------------------
TODAY...MAINLY VFR. AREAS OF MVFR CIGS THIS MORNING WITH SCT
SHOWERS/TSTMS THROUGH 15Z ACROSS S NH/N CENTRAL AND W MA INTO N
CENTRAL CT. TIMING ON EROSION OF MVFR CIGS TOUGH AS HUMIDITY
INCREASE WITH WARM FRONTAL PASSAGE. EXPECT ANY PRECIP THREAT TO
DIMINISH DURING THE AFTERNOON.
TONIGHT...EXPECT LINGERING MVFR/VFR CIGS. PATCHY FOG DEVELOPING
WITH MVFR VSBYS. IFR CIGS/VSBYS MAY DEVELOP AROUND OR AFTER
MIDNIGHT...ESPECIALLY OVER RI/E MA...THOUGH LOW CONFIDENCE ON
THIS ASPECT.
WEDNESDAY...MODERATE CONFIDENCE. MAINLY VFR...BUT AREAS OF EARLY
MORNING MVFR/IFR STRATUS/FOG. LOW PROB OF SCT TSTMS DURING THE
AFTERNOON/EVENING NW AREAS.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF THIS MORNING...THEN
INCREASING UNCERTAINTY THIS AFTN AND EVENING. ANY MVFR CLOUDS/CIGS
MAY BE STUBBORN TO BURN OFF THIS AFTN...THEN MAY REFORM TUE NIGHT
INTO IFR CONDITIONS.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF THROUGH TUE MORNING THEN
INCREASING UNCERTAINTY TUE AFTN AND NIGHT.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
WEDNESDAY NIGHT...LINGERING SHOWERS/TSTMS ESPECIALLY OVER SOUTHERN
NH AND NORTHWEST MASS. BRIEF LOW CIGS AND VSBYS WITH ANY STORMS.
THURSDAY...PATCHES OF FOG AND LOW CLOUDS THURSDAY MORNING WITH
RESULTING IFR CONDITIONS. AS THE CLOUDS BURN OFF...INCREASING
SOUTHWEST WINDS WITH GUSTS 20-25 KNOTS POSSIBLE IN THE AFTERNOON.
ALSO IN THE AFTERNOON/EVENING WILL BE A CHANCE OF SHOWERS/TSTMS WITH
BRIEF LOWERING OF CIGS/VSBYS AS WELL AS STRONG WIND GUSTS AND HEAVY
DOWNPOURS. WINDS SHIFT TO NORTHWEST AND DIMINISH LATE THURSDAY
NIGHT. MODERATE CONFIDENCE.
FRIDAY...POTENTIAL FOR LINGERING CLOUDS IN THE MORNING ESPECIALLY
CAPE COD AND ISLANDS. GENERALLY VFR WITH NORTHWEST WINDS GUSTING TO
20 KNOTS. MODERATE CONFIDENCE.
SATURDAY...VFR. MODERATE TO HIGH CONFIDENCE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH TUESDAY NIGHT/...HIGH CONFIDENCE.
TODAY...LIGHT S-SW WINDS WILL PICK UP AS WARM FRONT APPROACHES
THIS AFTERNOON. BIG QUESTION WILL BE HOW MUCH WIND MIXES DOWN
THIS AFTERNOON AS WARM AIR SURGES IN. WHILE IT IS MARGINAL...
DECIDED TO RAISE SMALL CRAFTS FOR THE OUTER WATERS WITH GUSTS TO
25 KT AND SEAS UP TO 5 FT.
TONIGHT...EXPECT SW WINDS TO CONTINUE THOUGH DIMINISHING DURING
THE OVERNIGHT HOURS. STILL EXPECT GUSTS UP TO 25 KT AND SEAS
AROUND 5 FT ON OUTER WATERS...BUT SHOULD SUBSIDE BY WED MORNING.
WITH HUMID AIRMASS IN PLACE...EXPECT PATCHY FOG TO DEVELOP WITH
LOCALLY DENSE POCKETS.
WEDNESDAY...SW WINDS CONTINUE THOUGH NOT QUITE AS GUSTY. MAY START
TO PICK UP AS COLD FRONT BEGINS TO APPROACH. SEAS MAY REMAIN
AROUND 5 FT ON THE SOUTHERN OUTER WATERS WITH CONTINUED SW FETCH.
VSBYS WILL LIKELY BE REDUCED DUE TO AREAS OF FOG...SOME LOCALLY
DENSE THROUGH MIDDAY.
OUTLOOK...WEDNESDAY NIGHT THROUGH SATURDAY...
WEDNESDAY NIGHT...SEAS REMAIN AROUND 5 FEET ON THE OUTER WATERS.
SOUTHWEST WINDS AROUND 15 KNOTS. A SMALL CRAFT ADVISORY MAY BE
NEEDED FOR THE OUTER WATERS.
THURSDAY...SOUTHWEST WINDS GUSTING TO 25 KNOTS. SEAS ON THE EXPOSED
WATERS WILL BE 5-6 FEET. A SMALL CRAFT ADVISORY WILL BE LIKELY FOR
THURSDAY. SHOWERS AND TSTMS DEVELOP AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT MOVES THROUGH DURING THURSDAY NIGHT...WINDS THEN
BECOME NORTHWEST.
FRIDAY... NORTHWEST WINDS GUSTING TO 20 KNOTS. SEAS START NEAR 5
FEET AND SUBSIDE THROUGH THE DAY.
SATURDAY...NORTH WINDS WITH GUSTS 20 TO 25 KNOTS ESPECIALLY EAST OF
CAPE COD. SEA RE-BUILD TO 5-6 FEET.
&&
.CLIMATE...
RECORD MAX TEMPS FOR WED 9/11...
BOS 99/1983
PVD 100/1983
BDL 99/1983
ORH 91/1983
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...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 6 PM EDT
WEDNESDAY FOR ANZ250-254>256.
&&
$$
SYNOPSIS...WTB/EVT
NEAR TERM...WTB/NOCERA/EVT
SHORT TERM...EVT
LONG TERM...WTB
AVIATION...WTB/NOCERA/EVT
MARINE...WTB/EVT
CLIMATE...
AREA FORECAST DISCUSSION
NWS ALBANY NY
203 AM EDT TUE SEP 10 2013
.SYNOPSIS...
AN AREA OF HIGH PRESSURE WILL CONTINUE TO MOVE AWAY FROM
THE REGION TONIGHT. A WARM FRONT WILL APPROACH THE REGION LATE
TONIGHT AND MOVE ACROSS THE REGION TUESDAY...ALLOWING FOR THE CHANCE
FOR SOME SHOWERS AND STRONG THUNDERSTORMS...MAINLY FOR AREAS TO
THE NORTH OF THE MOHAWK RIVER AND INTERSTATE 90. MUCH WARMER AND
MUGGY AIR WILL BE IN PLACE THROUGH THURSDAY WITH A CONTINUED
CHANCE FOR SHOWERS AND THUNDERSTORMS...BEFORE A STRONG COLD FRONT
BRINGS COOLER WEATHER BACK TO THE REGION FOR THE LATE WEEK PERIOD.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1230 AM EDT...SHOWERS ALONG WITH A FEW EMBEDDED
THUNDERSTORMS APPROACHING NW CORNER OF FA AND HAVE ADJUSTED POP
AND WEATHER GRIDS ACCORDING. THE HIGHER THERMAL AND THETA-E
GRADIENT MAGNITUDES WERE JUST NORTH OF THE GREAT LAKES REGION
ALONG WITH A WEST-SOUTHWEST LOW LEVEL JET. THE LINEAR CONVECTIVE
COMPLEX WAS DEVELOPING IN THE EASTERN U.P. OF MICHIGAN AND PER THE
CORFIDI AND 850-300 THICKNESS TRAJECTORIES...THERE IS THE
POTENTIAL FOR THIS UPSTREAM COMPLEX TO TRACK INTO UPSTATE NY
OVERNIGHT. LATEST HRRR REMAINS VERY AGGRESSIVE WITH TRACKING THIS
FEATURE INTO WESTERN NY LATE TONIGHT AND WEAKENING AS IT MOVES
ACROSS EASTERN NY AROUND SUNRISE. FOR NOW...WE RAISED POPS EARLIER
AND HAVE LEFT THOSE INTACT FOR THIS UPDATE. MODIFIED DEWPOINTS
UPWARD A BIT PER OBSERVATIONS AND LEFT OVERNIGHT LOWS PER THE
PREVIOUS FORECASTS.
AS OF 412 PM EDT...OUR REGION IS SITUATED ON THE NORTHERN SIDE OF
A STRONG RIDGE EXPANDING FROM THE CENTRAL PLAINS TOWARDS THE
SOUTHEASTERN CONUS. A SHORTWAVE EMBEDDED IN THE WESTERLY FLOW ON
THE TOP OF THE RIDGE IS MOVING ACROSS THE UPPER MIDWEST...AND IS
HEADED EASTWARD TOWARDS THE GREAT LAKES AND NORTHEAST.
MEANWHILE...HIGH PRESSURE OFF THE NEW ENGLAND COAST WILL CONTINUE TO
SLIDE EASTWARD AND AWAY FROM THE REGION TONIGHT. WHILE SKIES WILL
START OFF MOSTLY CLEAR/PARTLY CLOUDY...CLOUDS WILL INCREASE
THIS EVENING AND INTO THE OVERNIGHT AHEAD OF THE ADVANCING
SHORTWAVE. A SURFACE WARM FRONT WILL SITUATED ACROSS THE MIDWEST
AND MID ATLANTIC STATES...AND THIS WILL BE STARTING TO MOVE
NORTHEAST TOWARDS OUR AREA. THIS WARM FRONT CAN EASILY BE SEEN IN
THE OBSERVATIONS THIS AFTERNOON...WITH SIGNIFICANTLY WARMER TEMPS
IN THE UPPER 80S...AND DEWPOINTS IN THE UPPER 60S TO LOW 70S
ACROSS THE MIDWEST...AS WE SIT WITH TEMPS IN THE 60S AND DEWPOINTS
IN THE 40S ACROSS UPSTATE NY AND WESTERN NEW ENGLAND.
MODEL GUIDANCE SUGGESTS THAT A COMPLEX OF SHOWERS AND
THUNDERSTORMS...AIDED BY STRONG WARM AIR ADVECTION/ISENTROPIC
LIFT AND STEEP MID LEVEL LAPSE RATES...WILL MOVE EASTWARD ACROSS
ONTARIO AND THE ST. LAWRENCE VALLEY BY LATE TONIGHT. RIGHT
NOW...IT APPEARS THAT THE BULK OF THE ACTIVITY WILL REMAIN NORTH
OF OUR REGION...BUT THE SOUTHERN EXTENT OF THESE
SHOWERS/THUNDERSTORMS MAY BRUSH OUR ADIRONDACK ZONES. WE WILL GO
WITH CHC POPS FOR OUR NORTHERN ZONES FOR LATE TONIGHT...WITH
SLIGHT CHC POPS ELSEWHERE WITH THE APPROACH OF THE WARM FRONT.
WHILE SVR WX ISN/T ANTICIPATED WITH THIS ACTIVITY DUE TO THE
NOCTURNAL TIMING...HEAVY DOWNPOURS WILL BE POSSIBLE WITHIN ANY
THUNDERSTORM...DUE TO HIGHER PWAT AIR BEING ADVECTED INTO THE
REGION.
MIN TEMPS TONIGHT WON/T BE AS COOL AS RECENT NIGHTS...WITH MINS
GENERALLY IN THE 50S TO LOW 60S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
THERE WILL LIKELY BE SOME CONVECTIVE DEBRIS CLOUDS FOR TOMORROW
MORNING IN THE WAKE OF THE MORNING SHOWERS AND THUNDERSTORMS THAT
WILL BE MOVING ACROSS FAR NORTHERN PARTS OF THE AREA. DURING THE
MORNING HOURS...THE SFC WARM FRONT WILL BE LIFTING NORTHWARD...AND
DAYTIME MIXING SHOULD ALLOW FOR SOME BREAKS OF SUN TO EVENTUALLY
BREAK OUT.
ONCE THE SUN BREAKS OUT...TEMPS WILL BE MUCH WARMER THAN RECENT
DAYS...WITH LOW TO MID 80S ACROSS THE REGION...AND DEWPOINTS WILL
RETURN TO SUMMERLIKE LEVELS IN THE 60S. WITH THE WARM FRONT DRAPED
OR SLOWLY MOVING ACROSS THE NORTHERN PART OF THE AREA...THIS COULD
PROVIDE A FOCUS FOR ADDITIONAL SHOWER AND THUNDERSTORM
ACTIVITY...ESP DURING THE AFTN HOURS. ANY LINGERING BOUNDARIES
FROM THE MORNING CONVECTION COULD ALSO PROVIDE A FOCUS FOR
SHOWER/THUNDERSTORM DEVELOPMENT.
THERE IS THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS ON TUESDAY
FOR THE CENTRAL AND NORTHERN HALF OF THE AREA. 0-6 KM BULK SHEAR
VALUES WILL BE 30-40 KTS. IF SKIES CLEAR OUT ENOUGH AS THE MODELS
ANTICIPATE....THERE COULD BE AROUND 2000 J/KG OF CAPE. THE
PROXIMITY OF THE LOW LEVEL WARM FRONTAL BOUNDARY WOULD PROVIDE
SOME TURNING OF THE WINDS AT LOW LEVELS...AND THE 12Z NAM12 HAS
DEPICTED SOME IMPRESSIVE 0-1 KM HELICITY VALUES IN EXCESS OF 300
M2/S2 ACROSS OUR NORTHERN ZONES. ALSO IMPRESSIVE IS THE PRESENCE
OF AN ELEVATED MIXED LAYER /EML/ WITH MID LEVEL LAPSE RATES AT
700HPA-500HPA OF AROUND 7 C/KM.
IF DISCRETE CELLS DO DEVELOP...THERE WILL BE THE THREAT FOR
SUPERCELLS AND AN ISOLATED TORNADO TO DEVELOP...MAINLY FOR AREAS
TO THE NORTH OF MOHAWK VALLEY/I-90. WITH THE STRONG SHEAR...IT/S
POSSIBLE THAT ANY CELLS COULD MERGE AND ORGANIZE INTO BOW SEGMENTS OR
SQUALL LINE AS WELL...BRINGING A RISK OF DAMAGING WINDS. SPC HAS
PLACED THE CENTRAL/NORTHERN HALF OF OUR AREA IN A SLIGHT RISK FOR
SVR STORMS FOR TUESDAY. THE EXACT NATURE OF THE THREAT WILL HINGE ON
THE LOCATION OF THE SFC BOUNDARY DURING THE LATE MORNING/AFTN
HOURS...AND EXACTLY HOW MUCH INSTABILITY IS IN PLACE. IF THE FRONT
MOVES QUICKER AND/OR CLOUDS DO NOT CLEAR OUT...THE SVR THREAT WILL
BE LESS.
THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL DIMINISH ON TUESDAY
NIGHT AS THE WARM FRONT LIFTS NORTHWARD...AND OUR REGION IS IN THE
WARM SECTOR. MIN TEMPS ON TUESDAY NIGHT WILL BE IN THE 60S TO NEAR
70 WITH MUGGY CONDITIONS IN PLACE. ON WEDNESDAY...THERE WILL BE A
LOW CHC OR SLIGHT CHC FOR A SHOWER OR THUNDERSTORM DURING THE AFTN
HOURS...OTHERWISE IT WILL BE HOT AND STICKY. MAX TEMPS LOOK TO
REACH INTO THE 90S. MUGGY AND WARM CONDITIONS WILL CONTINUE INTO
WED NIGHT WITH MINS AGAIN IN THE 60S TO NEAR 70 WITH A CONTINUED
LOW CHC THREAT FOR A SHOWER OR THUNDERSTORM.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THURSDAY THROUGH FRIDAY NIGHT...LATEST MODEL GUIDANCE SHOWS AN UPPER
LEVEL LONGWAVE TROUGH MOVING SOUTHEAST ACROSS THE GREAT LAKES FROM
WESTERN ONTARIO. WITH OUR AREA BEING DOWNSTREAM OF THE TROUGH
AXIS...A BROAD AREA OF UPPER LEVEL DIVERGENCE ALONG WITH A COLD
FRONT PASSAGE ASSOCIATED WITH A SURFACE LOW DEVELOPING IN
NORTHERN MAINE WILL BRING TO THE REGION A SCATTERED TO LIKELY
CHANCE OF SHOWERS AND THUNDERSTORMS ESPECIALLY AS WE GO INTO
THURSDAY AFTERNOON. PRECIPITATION WILL WORK ITS WAY ACROSS THE
AREA FROM NORTHWEST TO SOUTHEAST AS THE FRONT MOVES THROUGH THE
REGION AND AS THE LOW PRESSURE SYSTEM EXITS OFF THE COAST INTO THE
CANADIAN MARITIMES. HIGH TEMPERATURES ON THURSDAY AHEAD OF THE
COLD FRONT WITH A SOUTH-SOUTHWESTERLY FLOW WILL ALLOW TEMPS TO
WARM UP INTO THE MID AND UPPER 70S IN THE HIGH TERRAIN TO LOWER
80S ACROSS THE HUDSON VALLEY. AS WE GO INTO THE DAY ON FRIDAY
AFTER THE COLD FRONT PASSES THROUGH THE REGION...A MORE DEFINED
FALL AIR MASS WILL MOVE INTO THE REGION AS HIGH TEMPERATURES ON
FRIDAY WILL ONLY RANGE FROM THE LOW TO MID 50S IN THE HIGH TERRAIN
TO THE UPPER 50S AND LOWER 60S FOR THE REST OF THE REGION WITH A
MUCH DRIER AIRMASS TO ACCOMPANY THE COOLER HIGH TEMPS. WITH SOME
MODELS SHOWING A UPPER LEVEL LOW WITH LOWER 550 DM HEIGHTS...HIGH
TEMPS ON FRIDAY WILL BE ABOUT 10 DEGREES BELOW NORMAL. SLIGHT POPS
REMAIN FOR THE AREA ON FRIDAY AS LAKE ENHANCED SHOWERS ALONG THE
WEST SIDE OF THE DEPARTING UPPER LEVEL LOW MAY IMPACT SOME AREAS
ESPECIALLY NORTH AND WEST OF THE IMMEDIATE CAPITAL REGION. LATEST
GUIDANCE ALSO SHOWS LOW TEMPS ON FRIDAY TO BE BELOW AVERAGE AS
WELL AS WE GET INTO A DOMINANT NORTHWEST FLOW WITH LARGE AREAS OF
UPPER LEVEL CONVERGENCE AND CLEARING SKIES. LOWS ON FRIDAY NIGHT
WILL RANGE FROM THE LOWER 30S IN THE ADIRONDACKS TO MID AND UPPER
30S FOR THE REST OF THE HIGH TERRAIN TO LOWER 40S IN VALLEY
LOCATIONS. MODEL GUIDANCE SHOWS COOL TEMPS WITH T850 NEAR 0C IN
THE ADIRONDACKS ALONG WITH 1C-3C ACROSS THE REST OF THE AREA AND
T925 TEMPS RANGING FROM 3C-5C ACROSS THE ENTIRE AREA.
SATURDAY THROUGH MONDAY...THE REST OF THE EXTENDED PERIOD LOOKS TO
BE RATHER TRANQUIL AS A HIGH PRESSURE SYSTEM FROM THE OHIO VALLEY
MOVES INTO THE REGION ON SATURDAY AND SLOWLY MOVES TO THE EAST
ACROSS OUR REGION THROUGHOUT THE WEEKEND. OUR NEXT CHANCE OF
PRECIPITATION AHEAD OF THE NEXT FRONTAL SYSTEM MOVING ACROSS THE
GREAT LAKES WILL BE DURING THE DAY ON MONDAY WHERE PRE-FRONTAL
SHOWERS MAY APPEAR IN THE HIGH TERRAIN ACROSS THE ADIRONDACKS.
OTHERWISE...A PLEASANT SECOND HALF OF THE EXTENDED WITH HIGH TEMPS
DURING THIS TIME EXPECTED TO BE FROM THE UPPER 50S TO MID 60S ON
SATURDAY WITH A WARM UP BY SUNDAY AND MONDAY WITH HIGHS RANGING FROM
THE MID 60S IN THE HIGH TERRAIN TO LOWER 70S IN VALLEY LOCATIONS.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
HIGH PRESSURE CONTINUES TO MOVE EAST OF THE GULF OF MAINE. A WARM
FRONT CONTINUES TO APPROACH FROM THE LOWER GREAT LAKES
REGION...AND THE OHIO VALLEY. THE WARM FRONT WILL MOVE THROUGH ERN
NY AND WRN NEW ENGLAND IN THE AFTERNOON...AS A WARM AND HUMID AIR
MASS BUILDS IN FROM THE SOUTH.
VFR CONDITIONS WILL CONTINUE TO LOWER TO MVFR LEVELS AS MVFR
STRATUS FORMS...AND MOVES IN FROM THE SOUTH. ALSO...SPOTTY SHOWERS
WITH A WEAK MID LEVEL DISTURBANCE...AND A WARM FRONT WILL IMPACT
THE TERMINALS BTWN 09Z-14Z. A VCSH GROUP WAS USED IN THIS TIME
FRAME TO ADDRESS SOME LIGHT SHOWERS AROUND. CIGS WILL FALL INTO
THE 1.5-3.0 KFT AGL RANGE IN THE WARM ADVECTION REGIME. THE CIGS
SHOULD RISE BACK TO VFR LEVELS TOWARDS 16Z/NOONTIME/.
SOME POP-UP SHOWERS AND THUNDERSTORMS MAY FORM IN THE WARM
SECTOR...AS THE BOUNDARY RACES N/NE INTO QUEBEC. SOME VCSH GROUP
WERE USED HERE WITH CIGS IN THE 3.5-5 KFT AGL RANGE. THUNDERSTORM
PROBS MAY NEED TO BE ADDED WITH LATER TAFS.
THE SKIES WILL LIKELY CLEAR THIS EVENING WITH MORE MOISTURE IN THE
BOUNDARY LAYER...SOME PATCHY MIST OR FOG MAY FORM BEFORE MIDNIGHT.
THE WINDS WILL BE LIGHT AND VARIABLE THIS MORNING...EXCEPT AT KALB
WHERE SOUTHERLY WINDS AROUND 10 KTS WILL CONTINUE DUE TO THE
CONFLUENT FLOW UP THE HUDSON RIVER VALLEY. THE 2.0 KFT AGL WINDS
WILL INCREASE TO ABOUT 30 KTS...SO LLWS GROUPS WERE KEPT IN FROM
ROUGHLY 09Z-14Z AT KPOU/KPSF/KGFL. ONCE THE WARM FRONT MOVES
NORTH...LLWS WILL NOT BE AN ISSUE. EXPECT S/SW WIND OF 8-15 KTS
WITH SOME GUSTS CLOSE TO 25 KTS AT KALB IN THE AFTERNOON
OUTLOOK...
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
THURSDAY: MODERATE OPERATIONAL IMPACT. NUMEROUS SHRA...TSRA.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
FRIDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
A WARM FRONT WILL TRACK THROUGH OUR AREA LATE TONIGHT INTO TOMORROW
WITH THE CHANCE FOR SHOWERS AND THUNDERSTORMS...MAINLY ACROSS
NORTHERN AREAS. THE THREAT FOR ADDITIONAL SHOWERS AND THUNDERSTORMS
WILL BE IN PLACE WEDNESDAY AND 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 AS A WARM FRONT MOVES THROUGH THE AREA TOMORROW...AND A
COLD FRONT 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...LFM
AVIATION...WASULA
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS ALBANY NY
1235 AM EDT TUE SEP 10 2013
.SYNOPSIS...
AN AREA OF HIGH PRESSURE WILL CONTINUE TO MOVE AWAY FROM
THE REGION TONIGHT. A WARM FRONT WILL APPROACH THE REGION LATE
TONIGHT AND MOVE ACROSS THE REGION TUESDAY...ALLOWING FOR THE CHANCE
FOR SOME SHOWERS AND STRONG THUNDERSTORMS...MAINLY FOR AREAS TO
THE NORTH OF THE MOHAWK RIVER AND INTERSTATE 90. MUCH WARMER AND
MUGGY AIR WILL BE IN PLACE THROUGH THURSDAY WITH A CONTINUED
CHANCE FOR SHOWERS AND THUNDERSTORMS...BEFORE A STRONG COLD FRONT
BRINGS COOLER WEATHER BACK TO THE REGION FOR THE LATE WEEK PERIOD.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1230 AM EDT...SHOWERS ALONG WITH A FEW EMBEDDED
THUNDERSTORMS APPROACHING NW CORNER OF FA AND HAVE ADJUSTED POP
AND WEATHER GRIDS ACCORDING. THE HIGHER THERMAL AND THETA-E
GRADIENT MAGNITUDES WERE JUST NORTH OF THE GREAT LAKES REGION
ALONG WITH A WEST-SOUTHWEST LOW LEVEL JET. THE LINEAR CONVECTIVE
COMPLEX WAS DEVELOPING IN THE EASTERN U.P. OF MICHIGAN AND PER THE
CORFIDI AND 850-300 THICKNESS TRAJECTORIES...THERE IS THE
POTENTIAL FOR THIS UPSTREAM COMPLEX TO TRACK INTO UPSTATE NY
OVERNIGHT. LATEST HRRR REMAINS VERY AGGRESSIVE WITH TRACKING THIS
FEATURE INTO WESTERN NY LATE TONIGHT AND WEAKENING AS IT MOVES
ACROSS EASTERN NY AROUND SUNRISE. FOR NOW...WE RAISED POPS EARLIER
AND HAVE LEFT THOSE INTACT FOR THIS UPDATE. MODIFIED DEWPOINTS
UPWARD A BIT PER OBSERVATIONS AND LEFT OVERNIGHT LOWS PER THE
PREVIOUS FORECASTS.
AS OF 412 PM EDT...OUR REGION IS SITUATED ON THE NORTHERN SIDE OF
A STRONG RIDGE EXPANDING FROM THE CENTRAL PLAINS TOWARDS THE
SOUTHEASTERN CONUS. A SHORTWAVE EMBEDDED IN THE WESTERLY FLOW ON
THE TOP OF THE RIDGE IS MOVING ACROSS THE UPPER MIDWEST...AND IS
HEADED EASTWARD TOWARDS THE GREAT LAKES AND NORTHEAST.
MEANWHILE...HIGH PRESSURE OFF THE NEW ENGLAND COAST WILL CONTINUE TO
SLIDE EASTWARD AND AWAY FROM THE REGION TONIGHT. WHILE SKIES WILL
START OFF MOSTLY CLEAR/PARTLY CLOUDY...CLOUDS WILL INCREASE
THIS EVENING AND INTO THE OVERNIGHT AHEAD OF THE ADVANCING
SHORTWAVE. A SURFACE WARM FRONT WILL SITUATED ACROSS THE MIDWEST
AND MID ATLANTIC STATES...AND THIS WILL BE STARTING TO MOVE
NORTHEAST TOWARDS OUR AREA. THIS WARM FRONT CAN EASILY BE SEEN IN
THE OBSERVATIONS THIS AFTERNOON...WITH SIGNIFICANTLY WARMER TEMPS
IN THE UPPER 80S...AND DEWPOINTS IN THE UPPER 60S TO LOW 70S
ACROSS THE MIDWEST...AS WE SIT WITH TEMPS IN THE 60S AND DEWPOINTS
IN THE 40S ACROSS UPSTATE NY AND WESTERN NEW ENGLAND.
MODEL GUIDANCE SUGGESTS THAT A COMPLEX OF SHOWERS AND
THUNDERSTORMS...AIDED BY STRONG WARM AIR ADVECTION/ISENTROPIC
LIFT AND STEEP MID LEVEL LAPSE RATES...WILL MOVE EASTWARD ACROSS
ONTARIO AND THE ST. LAWRENCE VALLEY BY LATE TONIGHT. RIGHT
NOW...IT APPEARS THAT THE BULK OF THE ACTIVITY WILL REMAIN NORTH
OF OUR REGION...BUT THE SOUTHERN EXTENT OF THESE
SHOWERS/THUNDERSTORMS MAY BRUSH OUR ADIRONDACK ZONES. WE WILL GO
WITH CHC POPS FOR OUR NORTHERN ZONES FOR LATE TONIGHT...WITH
SLIGHT CHC POPS ELSEWHERE WITH THE APPROACH OF THE WARM FRONT.
WHILE SVR WX ISN/T ANTICIPATED WITH THIS ACTIVITY DUE TO THE
NOCTURNAL TIMING...HEAVY DOWNPOURS WILL BE POSSIBLE WITHIN ANY
THUNDERSTORM...DUE TO HIGHER PWAT AIR BEING ADVECTED INTO THE
REGION.
MIN TEMPS TONIGHT WON/T BE AS COOL AS RECENT NIGHTS...WITH MINS
GENERALLY IN THE 50S TO LOW 60S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
THERE WILL LIKELY BE SOME CONVECTIVE DEBRIS CLOUDS FOR TOMORROW
MORNING IN THE WAKE OF THE MORNING SHOWERS AND THUNDERSTORMS THAT
WILL BE MOVING ACROSS FAR NORTHERN PARTS OF THE AREA. DURING THE
MORNING HOURS...THE SFC WARM FRONT WILL BE LIFTING NORTHWARD...AND
DAYTIME MIXING SHOULD ALLOW FOR SOME BREAKS OF SUN TO EVENTUALLY
BREAK OUT.
ONCE THE SUN BREAKS OUT...TEMPS WILL BE MUCH WARMER THAN RECENT
DAYS...WITH LOW TO MID 80S ACROSS THE REGION...AND DEWPOINTS WILL
RETURN TO SUMMERLIKE LEVELS IN THE 60S. WITH THE WARM FRONT DRAPED
OR SLOWLY MOVING ACROSS THE NORTHERN PART OF THE AREA...THIS COULD
PROVIDE A FOCUS FOR ADDITIONAL SHOWER AND THUNDERSTORM
ACTIVITY...ESP DURING THE AFTN HOURS. ANY LINGERING BOUNDARIES
FROM THE MORNING CONVECTION COULD ALSO PROVIDE A FOCUS FOR
SHOWER/THUNDERSTORM DEVELOPMENT.
THERE IS THE POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS ON TUESDAY
FOR THE CENTRAL AND NORTHERN HALF OF THE AREA. 0-6 KM BULK SHEAR
VALUES WILL BE 30-40 KTS. IF SKIES CLEAR OUT ENOUGH AS THE MODELS
ANTICIPATE....THERE COULD BE AROUND 2000 J/KG OF CAPE. THE
PROXIMITY OF THE LOW LEVEL WARM FRONTAL BOUNDARY WOULD PROVIDE
SOME TURNING OF THE WINDS AT LOW LEVELS...AND THE 12Z NAM12 HAS
DEPICTED SOME IMPRESSIVE 0-1 KM HELICITY VALUES IN EXCESS OF 300
M2/S2 ACROSS OUR NORTHERN ZONES. ALSO IMPRESSIVE IS THE PRESENCE
OF AN ELEVATED MIXED LAYER /EML/ WITH MID LEVEL LAPSE RATES AT
700HPA-500HPA OF AROUND 7 C/KM.
IF DISCRETE CELLS DO DEVELOP...THERE WILL BE THE THREAT FOR
SUPERCELLS AND AN ISOLATED TORNADO TO DEVELOP...MAINLY FOR AREAS
TO THE NORTH OF MOHAWK VALLEY/I-90. WITH THE STRONG SHEAR...IT/S
POSSIBLE THAT ANY CELLS COULD MERGE AND ORGANIZE INTO BOW SEGMENTS OR
SQUALL LINE AS WELL...BRINGING A RISK OF DAMAGING WINDS. SPC HAS
PLACED THE CENTRAL/NORTHERN HALF OF OUR AREA IN A SLIGHT RISK FOR
SVR STORMS FOR TUESDAY. THE EXACT NATURE OF THE THREAT WILL HINGE ON
THE LOCATION OF THE SFC BOUNDARY DURING THE LATE MORNING/AFTN
HOURS...AND EXACTLY HOW MUCH INSTABILITY IS IN PLACE. IF THE FRONT
MOVES QUICKER AND/OR CLOUDS DO NOT CLEAR OUT...THE SVR THREAT WILL
BE LESS.
THE THREAT FOR SHOWERS AND THUNDERSTORMS WILL DIMINISH ON TUESDAY
NIGHT AS THE WARM FRONT LIFTS NORTHWARD...AND OUR REGION IS IN THE
WARM SECTOR. MIN TEMPS ON TUESDAY NIGHT WILL BE IN THE 60S TO NEAR
70 WITH MUGGY CONDITIONS IN PLACE. ON WEDNESDAY...THERE WILL BE A
LOW CHC OR SLIGHT CHC FOR A SHOWER OR THUNDERSTORM DURING THE AFTN
HOURS...OTHERWISE IT WILL BE HOT AND STICKY. MAX TEMPS LOOK TO
REACH INTO THE 90S. MUGGY AND WARM CONDITIONS WILL CONTINUE INTO
WED NIGHT WITH MINS AGAIN IN THE 60S TO NEAR 70 WITH A CONTINUED
LOW CHC THREAT FOR A SHOWER OR THUNDERSTORM.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THURSDAY THROUGH FRIDAY NIGHT...LATEST MODEL GUIDANCE SHOWS AN UPPER
LEVEL LONGWAVE TROUGH MOVING SOUTHEAST ACROSS THE GREAT LAKES FROM
WESTERN ONTARIO. WITH OUR AREA BEING DOWNSTREAM OF THE TROUGH
AXIS...A BROAD AREA OF UPPER LEVEL DIVERGENCE ALONG WITH A COLD
FRONT PASSAGE ASSOCIATED WITH A SURFACE LOW DEVELOPING IN
NORTHERN MAINE WILL BRING TO THE REGION A SCATTERED TO LIKELY
CHANCE OF SHOWERS AND THUNDERSTORMS ESPECIALLY AS WE GO INTO
THURSDAY AFTERNOON. PRECIPITATION WILL WORK ITS WAY ACROSS THE
AREA FROM NORTHWEST TO SOUTHEAST AS THE FRONT MOVES THROUGH THE
REGION AND AS THE LOW PRESSURE SYSTEM EXITS OFF THE COAST INTO THE
CANADIAN MARITIMES. HIGH TEMPERATURES ON THURSDAY AHEAD OF THE
COLD FRONT WITH A SOUTH-SOUTHWESTERLY FLOW WILL ALLOW TEMPS TO
WARM UP INTO THE MID AND UPPER 70S IN THE HIGH TERRAIN TO LOWER
80S ACROSS THE HUDSON VALLEY. AS WE GO INTO THE DAY ON FRIDAY
AFTER THE COLD FRONT PASSES THROUGH THE REGION...A MORE DEFINED
FALL AIR MASS WILL MOVE INTO THE REGION AS HIGH TEMPERATURES ON
FRIDAY WILL ONLY RANGE FROM THE LOW TO MID 50S IN THE HIGH TERRAIN
TO THE UPPER 50S AND LOWER 60S FOR THE REST OF THE REGION WITH A
MUCH DRIER AIRMASS TO ACCOMPANY THE COOLER HIGH TEMPS. WITH SOME
MODELS SHOWING A UPPER LEVEL LOW WITH LOWER 550 DM HEIGHTS...HIGH
TEMPS ON FRIDAY WILL BE ABOUT 10 DEGREES BELOW NORMAL. SLIGHT POPS
REMAIN FOR THE AREA ON FRIDAY AS LAKE ENHANCED SHOWERS ALONG THE
WEST SIDE OF THE DEPARTING UPPER LEVEL LOW MAY IMPACT SOME AREAS
ESPECIALLY NORTH AND WEST OF THE IMMEDIATE CAPITAL REGION. LATEST
GUIDANCE ALSO SHOWS LOW TEMPS ON FRIDAY TO BE BELOW AVERAGE AS
WELL AS WE GET INTO A DOMINANT NORTHWEST FLOW WITH LARGE AREAS OF
UPPER LEVEL CONVERGENCE AND CLEARING SKIES. LOWS ON FRIDAY NIGHT
WILL RANGE FROM THE LOWER 30S IN THE ADIRONDACKS TO MID AND UPPER
30S FOR THE REST OF THE HIGH TERRAIN TO LOWER 40S IN VALLEY
LOCATIONS. MODEL GUIDANCE SHOWS COOL TEMPS WITH T850 NEAR 0C IN
THE ADIRONDACKS ALONG WITH 1C-3C ACROSS THE REST OF THE AREA AND
T925 TEMPS RANGING FROM 3C-5C ACROSS THE ENTIRE AREA.
SATURDAY THROUGH MONDAY...THE REST OF THE EXTENDED PERIOD LOOKS TO
BE RATHER TRANQUIL AS A HIGH PRESSURE SYSTEM FROM THE OHIO VALLEY
MOVES INTO THE REGION ON SATURDAY AND SLOWLY MOVES TO THE EAST
ACROSS OUR REGION THROUGHOUT THE WEEKEND. OUR NEXT CHANCE OF
PRECIPITATION AHEAD OF THE NEXT FRONTAL SYSTEM MOVING ACROSS THE
GREAT LAKES WILL BE DURING THE DAY ON MONDAY WHERE PRE-FRONTAL
SHOWERS MAY APPEAR IN THE HIGH TERRAIN ACROSS THE ADIRONDACKS.
OTHERWISE...A PLEASANT SECOND HALF OF THE EXTENDED WITH HIGH TEMPS
DURING THIS TIME EXPECTED TO BE FROM THE UPPER 50S TO MID 60S ON
SATURDAY WITH A WARM UP BY SUNDAY AND MONDAY WITH HIGHS RANGING FROM
THE MID 60S IN THE HIGH TERRAIN TO LOWER 70S IN VALLEY LOCATIONS.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS ARE EXPECTED UNTIL THE WARM FRONT GETS CLOSER AND
CIGS LOWER DUE TO WARM AIR ADVECTION WITH MVFR CONDITIONS
EXPECTED OVERNIGHT. AN IMPROVEMENT BACK TO VFR WILL OCCUR WITH
THE WARM FRONTAL PASSAGE DURING THE DAYLIGHT MORNING HOURS
TUESDAY.
THERE WILL BE A CHANCE FOR CONVECTION LATER TONIGHT AS THE
STRENGTH OF WARM ADVECTION AND FORCING WILL RESULT IN SOME
SCATTERED ACTIVITY. HOWEVER...WE WILL PLACE `VCSH` AT THIS TIME
UNTIL TRENDS UNFOLD UPSTREAM.
WE ARE EXPECTED TO BE WELL INTO THE WARM SECTOR TUESDAY AS
CONVECTIVE TRENDS WILL BECOME A CHALLENGE. AT THIS TIME...WE WILL
KEEP THE MENTION OUT OF THE TAFS...
SOUTH WINDS 5 TO 10 KNOTS WILL DIMINISH THIS EVENING. LOW LEVEL
WINDS WILL INCREASE TO AROUND 30 KNOTS OVERNIGHT SO HAVE CONTINUED
LOW LEVEL WIND SHEAR IN TAFS. ONCE THE WARM FRONT MOVES BY THREAT OF
LLWS WILL END AND SOUTH-SOUTHWEST SURFACE FLOW WILL DEVELOP WITH
GUSTY CONDITIONS EXPECTED...MORE NOTICEABLE AT KALB.
OUTLOOK...
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
WEDNESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
THURSDAY: MODERATE OPERATIONAL IMPACT. NUMEROUS SHRA...TSRA.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
FRIDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
A WARM FRONT WILL TRACK THROUGH OUR AREA LATE TONIGHT INTO TOMORROW
WITH THE CHANCE FOR SHOWERS AND THUNDERSTORMS...MAINLY ACROSS
NORTHERN AREAS. THE THREAT FOR ADDITIONAL SHOWERS AND THUNDERSTORMS
WILL BE IN PLACE WEDNESDAY AND 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 AS A WARM FRONT MOVES THROUGH THE AREA TOMORROW...AND A
COLD FRONT 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...LFM
AVIATION...IAA/BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
344 AM EDT TUE SEP 10 2013
.SYNOPSIS...
A WARM FRONT WAS LIFTING THROUGH OUR REGION EARLY THIS MORNING.
VERY WARM HIGH PRESSURE IS FORECAST TO INFLUENCE NORTHEASTERN
MARYLAND, DELAWARE, EASTERN PENNSYLVANIA AND NEW JERSEY DURING THE
MID WEEK PERIOD. A STRONG COLD FRONT IS EXPECTED TO APPROACH FROM
THE NORTHWEST ON THURSDAY AND IT SHOULD PASS THROUGH OUR REGION ON
THURSDAY NIGHT. HIGH PRESSURE IS ANTICIPATED TO FOLLOW FOR FRIDAY
AND FOR THE WEEKEND. ANOTHER COLD FRONT FROM THE NORTHWEST MAY
ARRIVE EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW PRESSURE NR THE NR GRTLKS WAS SLOWLY MOVG EWD AND ITS ASSOCD
WMFNT WAS MOVG THRU THE AREA. THIS FRONT WILL BRING A MARKED RISE
IN TEMPS OVER THE NEXT FEW DAYS, BEGINNING WITH TODAY AN HAD
TRIGGERED SOME EARLIER SHOWERS OVER NERN PA. HOWEVER, LATEST RADAR
IMAGERY INDICATED THAT THESE SHOWERS HAVE ALL BUT FALLEN APART.
LATEST HRRR GUID INDICATES THAT REGION SHUD REMAIN DRY THRU THE
ERLY MRNG AND ALL OF THE GUID INDICATES A DRY DAY, SO WILL REMOVE
ALL POPS ATTM, EXCEPT FOR EXTREME NRN NJ. TEMPS WILL AVERAGE 7 TO
10 DEGREES ABV NRML. THIS WILL ULTIMATELY DEPEND ON HOW QUICKLY WE
CLEAR OUT. LATEST GUID INDICATES THAT THE MRNG WILL START OUT
FAIRLY CLOUDY WITH LINGERING STRATUS, BUT BY LATE MRNG/ERLY AFTN
THE SKY WILL BECOME MOSTLY SUNNY AND TEMPS SHUD WARM QUITE NICELY
AS SWLY FLOW INCREASES, WELL INTO THE 80S AND PSBLY EVEN PUSH 90
IN SOME AREAS, IF THE WARMER MET MOS IS CORRECT. DEW POINTS WILL
RISE AS WELL MAKING FOR THE START OF A RATHER UNCOMFORTABLE
PERIOD.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
WITH THE AFOREMENTIONED LOW OVER ERN CANADA AND HIGH PRESSURE
BUILDING TO THE S, WE WILL BE IN THE WARM SECTOR AND IT WILL BE A
RATHER UNEVENTFUL NIGHT. TEMPS WILL REMAIN WARM AND DEW POINTS
WILL INCREASE A BIT MORE SO A HUMID NIGHT IS IN STORE.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
VERY WARM AIR SHOULD BE IN PLACE OVER OUR REGION FOR WEDNESDAY.
TEMPERATURES AT 850 HPA ARE FORECAST TO CLIMB AROUND +19C TO +20C
WITH THE WARMEST OF THE AIR BEING ACROSS THE NORTH. TEMPERATURES
ARE EXPECTED TO REACH THE LOWER 90S IN MUCH OF OUR FORECAST AREA.
ONE EXCEPTION WILL BE THE ELEVATED TERRAIN UP NORTH WHERE HIGH
TEMPERATURES SHOULD BE IN THE UPPER 80S. MAXIMUM READINGS IN THE
80S ARE ANTICIPATED RIGHT ALONG THE COAST. DEW POINT TEMPERATURES
NEAR 70 SHOULD RESULT IN MAXIMUM HEAT INDEX VALUES IN THE MIDDLE
9OS AT MOST LOCATIONS.
THERE WILL BE RELATIVELY MILD TEMPERATURES AND SOME RIDGING ALOFT
ON WEDNESDAY LIMITING CONVECTIVE DEVELOPMENT. WE WILL CONTINUE TO
MENTION A CHANCE OF MAINLY AFTERNOON THUNDERSTORMS IN OUR
NORTHWESTERN COUNTIES FOR WEDNESDAY. WE ARE NOT EXPECTING ANY
PRECIPITATION ALONG THE INTERSTATE 95 CORRIDOR OR ON THE COASTAL
PLAIN.
THE CORE OF THE WARM AIR IS EXPECTED TO LIFT TO OUR NORTHEAST ON
WEDNESDAY NIGHT AND THURSDAY. TEMPERATURES AT 850 HPA ARE FORECAST
TO SLIP DOWN INTO THE +17C TO +18C RANGE FOR THURSDAY AFTERNOON.
MAXIMUM READINGS AT THE SURFACE ARE EXPECTED TO BE GENERALLY ABOUT
3F TO 5F DEGREES LOWER THAN THOSE ON WEDNESDAY. THE DIFFERENCE MAY
BE A BIT GREATER IF THERE IS MORE CLOUD COVER THAN ANTICIPATED.
THE MID LEVEL RIDGE WILL LIKELY CONTINUE TO LOSE ITS INFLUENCE
OVER OUR WEATHER ON THURSDAY. THERE SHOULD BE AN INCREASING CHANCE
OF SHOWERS AND THUNDERSTORMS AS A STRONG COLD FRONT BEGINS TO
APPROACH FROM THE NORTHWEST. IT APPEARS AS THOUGH THE COLD FRONT
WILL PUSH THROUGH OUR REGION LATE ON THURSDAY NIGHT. ADDITIONAL
SHOWERS AND THUNDERSTORMS ARE EXPECTED FOR THURSDAY EVENING IN
ADVANCE OF THE BOUNDARY.
STRONG COLD ADVECTION IS EXPECTED FOR LATE THURSDAY NIGHT AND
FRIDAY. MAXIMUM TEMPERATURES ON FRIDAY SHOULD BE ABOUT 15 TO 20
DEGREES COOLER THAN THOSE ON THURSDAY.
HIGH PRESSURE IS FORECAST TO BRING DRY WEATHER AND BELOW NORMAL
TEMPERATURES FOR SATURDAY AND SUNDAY.
ANOTHER COLD FRONT FROM THE NORTHWEST IS EXPECTED TO ARRIVE ON
MONDAY. THE 0000 UTC GFS BRINGS THE BOUNDARY THROUGH OUR REGION
DRY WHILE THE 0000 UTC ECMWF INDICATES SOME SHOWERS WITH THE
FRONT. BEING THAT WE ARE NOT GETTING A UNIFIED SIGNAL AT THIS
TIME, WE WILL LEAVE THE MENTION OF PRECIPITATION OUT OF MONDAY`S
FORECAST, AT LEAST FOR THE TIME BEING.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
CONDS RANGED FROM VFR TO MVFR ACRS THE REGION EARLY THIS MRNG.
THERE COULD BE A BIT MORE DETERIORATION TWD DAY BREAK AND ITS
STILL PSBL TO SEE SOME FOG, BUT IT APPEARS THAT ANY WIDESPREAD IFR
CONDS WILL BE AVOIDED.
CONDS WILL REMAIN GENLY MVFR UNTIL MID MRNG THEN IMPROVE TO VFR
FOR THE BALANCE OF THE DAY. THERE COULD BE SOME LCL MVFR FOG
OVERNIGHT AS DEW POINTS CONTINUE TO INCREASE IN WHAT WOULD NRMLY
BE A SUMMERTIME AMS.
THE WIND IS EXPECTED TO BE SWLY GENLY INCREASING TO AROUND 10 KTS
DURG THE AFTN BEFORE DIMINISHING TO 5-8 KTS AFTER SUNSET.
OUTLOOK...
WEDNESDAY...MAINLY VFR AFTER POSSIBLE EARLY MORNING VISIBILITY
RESTRICTIONS. A CHANCE OF AFTERNOON SHOWERS AND THUNDERSTORMS NEAR
KRDG AND KABE.
WEDNESDAY NIGHT...MAINLY VFR EARLY, THEN POSSIBLE LOW CLOUDS AND
VISIBILITY RESTRICTIONS LATE.
THURSDAY...MAINLY VFR AFTER POSSIBLE EARLY MORNING LOW CLOUDS AND
VISIBILITY RESTRICTIONS. A CHANCE OF SHOWERS AND THUNDERSTORMS
WHICH MAY BE ACCOMPANIED BY IFR CONDITIONS.
THURSDAY NIGHT...MAINLY VFR. A CHANCE OF SHOWERS AND
THUNDERSTORMS MAINLY IN THE EVENING.
FRIDAY THROUGH SATURDAY...MAINLY VFR.
&&
.MARINE...
RELATIVELY QUIET CONDS ARE EXPECTED ON THE AREA WATERS WITH SEAS
IN THE 3 TO 4 FT RANGE AND A SW WIND GENLY 10 TO 15 KT WITH GUSTS
TO AROUND 20 KT. NO SCA FLAGS ARE ANTICIPATED DURG THE NEAR AND
SHORT TERM PDS.
OUTLOOK...
HIGH PRESSURE IS FORECAST TO INFLUENCE THE COASTAL WATERS OF NEW
JERSEY AND DELAWARE FOR WEDNESDAY AND THURSDAY. A STRONG COLD
FRONT FROM THE NORTHWEST IS EXPECTED TO ARRIVE LATE ON THURSDAY
NIGHT FOLLOWED BY ANOTHER AREA OF HIGH PRESSURE FOR FRIDAY AND
SATURDAY. WIND GUSTS MAY REACH OR EXCEED 25 KNOTS FROM FRIDAY INTO
SATURDAY IN THE COLD ADVECTION. WAVE HEIGHTS ON OUR OCEAN WATERS
MAY APPROACH 5 FEET AT THAT TIME.
&&
.CLIMATE...
THE MOST RECENT 90 DEGREES IN OUR AREA THIS SUMMER /CLIMATE
SITES/...
ACY...AUGUST 9.
PHL...JULY 21.
ILG...JULY 21.
ABE...JULY 20.
RDG...JULY 20.
TTN...JULY 20.
GED...JULY 24.
MPO...JULY 18.
RECORD HIGH TEMPERATURES FOR SEPTEMBER 11TH ARE MOSTLY OUT OF
REACH, HOWEVER THEY ARE INCLUDED BELOW AS A REFERENCE...
ABE....96 IN 1983.
ACY....99 IN 1983.
ILG...100 IN 1983.
MPO....89 IN 1983. HAS A GOOD CHANCE OF BEING NEAR RECORD.
PHL....98 IN 1983.
RDG....98 IN 1983.
TTN...100 IN 1983.
GED....92 IN 1989 /DATA MISSING FOR 1983/.
NOTE: PER MEDIA INQUIRY. LATEST EVER 90F IN PHL OCT 10
1939.
AVG NUMBER OF SEPTEMBER 90 DEGREE DAYS IN PHL 1.1.
ALL TIME PHL SEPT RECORD 102 ON SEPT 7 1881.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...IOVINO
NEAR TERM...NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...IOVINO
AVIATION...IOVINO/NIERENBERG
MARINE...IOVINO/NIERENBERG
CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
352 AM EDT TUE SEP 10 2013
.DISCUSSION...
TODAY-TONIGHT...
H100-H70 RIDGE AXIS EXTENDING FROM THE SRN PLAINS INTO THE
CENTRAL ATLC NE GOMEX TO NOVA SCOTIA WILL GENERATE A DEEP E/NE
FLOW REGIME ACRS CENTRAL FL. DUE TO THE ELONGATED NATURE OF THE
RIDGE THE ERLY FETCH EXTENDS WELL PAST THE BAHAMA BANK TO THE
REMNANT CIRCULATION OF FORMER T.C. GABRIELLE.
WITH SUCH A CLEAR SOURCE REGION...THE FCST IS PRETTY STRAIGHT
FORWARD. THE IMMEDIATE UPSTREAM AIRMASS IS ON THE DRY SIDE...LATEST
RUC ANALYSIS SHOWS THE H100-H70 MEAN RH VALUES AS LOW AS 50PCT E OF
KJAX...INCREASING TO ARND 80PCT OVER THE NRN BAHAMAS. A DEEP
MOISTURE TONGUE BEHIND THE DRY AIR SLUG WILL PUSH INTO THE FL
PENINSULA EVENTUALLY...BUT NOT UNTIL AFT SUNSET.
ALOFT...A RIPPLE IN THE H85-H50 VORT FIELD EMBEDDED IN THE ERLY FLOW
N OF THE BAHAMAS WILL GENERATE SOME MID LVL SUPPORT FOR PRECIP.
HOWEVER...THIS WILL BE COUNTERED BY THE POSITION OF A HIGH AMPLITUDE
TUTT AXIS EXTENDING FROM THE SE GOMEX ACRS S FL. THIS FEATURE HAS
BEEN NEARLY STATIONARY FOR THE PAST SEVERAL HRS DUE TO THE CUTOFF
LOW N OF THE BAHAMAS...AS CUTOFFS ARE SO WONT TO DO.
BOTH GFS AND ECMWF DRIFT THE TUTT AXIS SLOWLY NW THRU SUNRISE
WED...BUT MOST OF THE CWA WILL BE UNDER THE INFLUENCE OF ITS
DESCENDING FLANK THRU SUNSET. FURTHERMORE...DEEP E/NERLY FLOW
REGIMES TEND TO FAVOR THE W FL PENINSULA FOR HIGHEST PRECIP
COVERAGE. POPS WILL REFLECT THE MOISTURE PROFILE WITH BLO 20PCT OVER
THE NRN CWA...INCREASING TO 30PCT OVER THE SRN COUNTIES. WILL KEEP
TSRAS ISOLD AND LIMIT THEM TO THE INTERIOR COUNTIES AS NE FLOW
TYPICALLY DOES NOT SUPPORT DEEP CONVECTION OVER THE E CENTRAL
PENINSULA. MAX TEMPS WITHIN A DEG OR TWO OF 90F.
DEEP 10-15KT ERLY FLOW WILL CONTINUE OVERNIGHT WHILE THE TUTT AXIS
DRIFTS NWD ACRS THE CENTRAL PENINSULA...GRADUALLY PLACING THE CWA
UNDER ITS ASCENDING FLANK. BY THEN...THE DEEP MOISTURE NE OF THE
BAHAMAS WILL HAVE PUSHED FAR ENOUGH INTO THE CWA TO REQUIRE MENTION
OF A SLGT CHC OF SHRAS ALL COUNTIES OVERNIGHT. ONSHORE FLOW WILL
KEEP MIN TEMPS A FEW DEG ABV AVG (L/M70S).
WED-THU...
MAIN FEATURE OF NOTE WILL BE MID-UPPER LEVEL COLD LOW THAT IS
FORECAST TO MOVE SLOWLY NORTHWEST INTO CENTRAL FLORIDA WED AND
THEN SHIFT NORTH OF THE AREA THU. AT THE SURFACE...A HIGH PRESSURE
RIDGE NORTH OF THE STATE WILL BRING AN ONSHORE FLOW 10-15 MPH ON
WED...THEN THE RIDGE WILL WEAKEN THU AND SHIFT CLOSER TO CENTRAL
FLORIDA. THIS WILL CAUSE ONSHORE FLOW TO WEAKEN...HOWEVER THE GFS
INDICATES A WEAK LOW LEVEL TROUGH AFFECTING THE AREA.
MOISTURE IS FORECAST TO INCREASE THROUGH THE PERIOD SO EXPECT
SCATTERED POPS 30-40 PERCENT WED AND 40-50 PERCENT THU.
WITH COLDER TEMPS ALOFT...SOME AFTERNOON STORMS...ESPECIALLY
ACROSS THE INTERIOR...SHOULD BE STRONG.
FRI-WEEKEND...
MID TO UPPER LEVEL TROUGH SHOULD LIFT OUT TO THE NORTHEAST BY
EARLY FRI BUT WEAK SURFACE RIDGE AXIS NEAR OKEECHOBEE WILL DELAY
INLAND PUSH OF THE SEA BREEZE. THIS SHOULD ALLOW FOR ISOLATED
AFTERNOON STORMS TO FORM ON THE SLOWLY INLAND MOVING SEA
BREEZE...THEN COVERAGE SHOULD INCREASE TO SCATTERED BY LATE
AFTERNOON AS BOUNDARY INTERACTIONS BECOME MORE NUMEROUS.
OVER THE WEEKEND...A WEAK FRONTAL TROUGH IS FORECAST TO PUSH
SOUTH OVER THE ATLANTIC WATERS AND GRADUALLY WASH OUT. WEAK HIGH
PRESSURE RIDGE VICINITY EAST CENTRAL FLORIDA ON SAT WILL CAUSE
LIGHT WINDS AND EXPECT POPS AROUND 30 PERCENT COAST AND 40 PERCENT
INLAND. STRONGER HIGH PRESSURE BUILDING NORTH OF THE REGION ON
SUNDAY WILL PRODUCE ONSHORE LOW LEVEL FLOW AND RATHER UNIFORM POPS
AROUND 30 PERCENT EXPECTED.
MON-TUE...
THE ONSHORE FLOW PATTERN WILL CONTINUE THROUGH EARLY NEXT WEEK.
THIS WILL FAVOR NIGHT/MORNING RAIN CHANCES ALONG THE COAST AND THE
GREATEST CHANCE FOR STORMS TO BE INLAND DURING THE AFTERNOON.
&&
.AVIATION...
THRU 10/17Z...E/NE SFC WNDS 4-8KTS INCREASING TO 10-12KTS BTWN
12Z-14Z...BRIEF MVFR SHRAS COASTAL SITES. BTWN 10/17Z-10/24Z...E/NE
SFC WND G20-23KTS ALL SITES...SCT MVFR SHRAS/ISOLD IFR TSRAS S OF
KVRB-KGIF...ISOLD MVFR SHRAS/IFR TSRAS N OF KVRB-KGIF...STORM MOTION
W/SW ARND 15-20KTS. AFT 11/24Z...E/NE SFC WNDS DIMINISHING TO
4-8KTS...ISOLD MVFR SHRAS ALL SITES.
&&
.MARINE...
TODAY-TONIGHT...
ELONGATED SFC RIDGE EXTENDING FROM THE NE GOMEX TO NOVA SCOTIA
WILL GENERATE A GENTLE TO MODERATE ERLY BREEZE ACRS THE LCL ATLC.
THESE WINDS WILL CONTINUE TO PUSH A 2-3FT ERLY SWELL INTO THE E FL
COAST. DATA BUOYS CONFIRM THIS WITH 2-3FT SEAS NEARSHORE AND 3-4FT
SEAS OFFSHORE. MOST RECENT OBS SHOW THE DOMINANT PDS HAVE FALLEN
FROM 8-9SEC DOWN TO 4-6SEC. LATEST RUC ANALYSIS DOES SHOW A SMALL
WIND SURGE UPSTREAM WITH SFC/LOW LVL WINDS ARND 15KTS ON COURSE TO
AFFECT THE LCL ATLC AFT SUNRISE. THE 10/00Z SWAN GUIDANCE HAS
PICKED UP ON THIS BY DROPPING SHORTENING THE DOMINANT PDS OVER THE
NEARSHORE LEG BLO 6SEC BY EARLY AFTN...THEN INTO THE OFFSHORE
WATERS OVERNIGHT.
WED-SAT...
EAST FLOW ON WED LOOKS TO BE 10-15 KNOTS WITH SCATTERED SHOWERS
AND ISOLATED STORMS OCCURRING...EVEN DURING THE DAY AS A MID-UPPER
LEVEL LOW WILL BE NEARBY.
ONSHORE WINDS WILL DIMINISH TO 10 KNOTS OR LESS ON THU AND STILL
EXPECT SCATTERED SHOWERS AND ISOLATED STORMS DUE TO HIGH MOISTURE
AND A TROUGH ALOFT.
HIGH PRESSURE RIDGE OVER CENTRAL TO SOUTH CENTRAL FLORIDA ON FRI
SHOULD PRODUCE A LIGHT OFFSHORE WIND FLOW. SCATTERED AFTERNOON
STORMS OVER THE MAINLAND MAY PUSH BACK TO THE COAST OR AT LEAST
PRODUCE GUSTY OUTFLOW BOUNDARY WINDS THAT AFFECT THE COAST.
WEAK HIGH PRESSURE RIDGE NEARBY ON SAT SHOULD PRODUCE WINDS LESS
THAN 10 KNOTS. SCATTERED AFTERNOON STORMS SHOULD REMAIN OVER THE
MAINLAND.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 88 74 89 74 / 20 20 30 20
MCO 91 74 92 72 / 20 20 30 20
MLB 88 74 89 74 / 20 20 30 20
VRB 88 73 89 73 / 20 20 30 20
LEE 91 72 92 74 / 20 20 30 20
SFB 90 74 92 74 / 20 20 30 20
ORL 91 75 91 75 / 20 20 30 20
FPR 88 73 88 73 / 30 20 40 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...BRAGAW
LONG TERM....LASCODY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
350 AM EDT TUE SEP 10 2013
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS NORTHERN STREAM FLOW
RIDING THROUGH THE GREAT LAKES/NEW ENGLAND REGION OVER THE TOP OF
LONGWAVE RIDGING CENTERED OVER THE SE CONUS. EASTERN PERIPHERY OF
THIS RIDGE IS BEING PUSHED BACK BY AN ORGANIZING UPPER LEVEL LOW
SPINNING OFF THE GA/NE FLORIDA COAST. THIS UPPER LOW WILL RETROGRADE
DURING THE NEXT 24-30 HOURS TO A POSITION OVER CENTRAL AND NORTHERN
FLORIDA. 00Z KTBW SOUNDING STILL SHOWED A FAIRLY DRY PROFILE ABOVE
750MB WITH A DEEP MIXED BOUNDARY LAYER. THE LOWER PORTION OF THIS
PROFILE IS MORE REMINISCENT OF THE WELL MIXED DAYS WE SEE DURING THE
LATE SPRING. THE DRY MID/UPPER LEVELS NOTED ON THE SOUNDING ARE
DISPLAYED WELL IN THE EARLY MORNING WV IMAGERY OVER THE STATE. THIS
DEEP AND HOSTILE LAYER TO DEEP CONVECTION WILL HOLD ON FOR ANOTHER
DAY...WITH THE CONTINUING TREND OF THE DEEPEST AND MOST HOSTILE
AIRMASS FROM THE TAMPA BAY AREA NORTHWARD THROUGH THE NATURE COAST.
THE AIRMASS ALOFT ALONG WITH GENERAL SYNOPTIC SUPPRESSION ARE
KEEPING SKIES MOSTLY CLEAR THIS MORNING.
AT THE SURFACE...1020+MB HIGH PRESSURE IS CENTERED OVER THE
MID-ATLANTIC/CAROLINAS AND EXTENDS SOUTH TO THE FL PENINSULA AND
NORTHEAST GULF OF MEXICO. THE EXPECTED NOCTURNAL SURGE OVER THE
COASTAL WATERS DEVELOPED DURING THE LATE EVENING WITH MANY COASTAL
AND OFFSHORE STATIONS SEEING WINDS BETWEEN 15-20KTS WITH EVEN SOME
HIGHER GUSTS AT A FEW SPOTS LIKE CEDAR KEY. THE HIGH POSITION AND
STRENGTH WILL FAVOR ONE MORE NIGHT WITH A POTENTIALLY CAUTIONARY
LEVEL SURGE OVER THE COASTAL WATERS BEGINNING SHORTLY AFTER SUNSET
THIS EVENING.
&&
.SHORT TERM (TODAY THROUGH THURSDAY)...
TODAY/TONIGHT...
THE DRY AIR ALOFT WILL CONTINUE TO HINDER DEEP CONVECTION
DEVELOPMENT. WITH STRONG HIGH PRESSURE CENTERED TO OUR NORTH...THE
LOW LEVEL FLOW HAS BECOME DEFINED EASTERLY FOR ALL ZONES. THIS FLOW
WILL HELP TO FOCUS AT LEAST SOME LOW LEVEL CONVERGENCE ALONG THE
FLORIDA WEST COAST...CAUSE OTHERWISE EVEN ISOLATED STORMS WOULD BE
HARD TO DEVELOP UNDER THIS ENVIRONMENT. THE FLOW APPEARS TOO STRONG
IN ORDER TO ALLOW A DEFINED SEA-BREEZE TO DEVELOP...HOWEVER AT LEAST
SOME WEAKENING/COLLAPSE OF THE LOCAL GRADIENT DURING THE AFTERNOON
ACROSS THE NEAR SHORE WATERS SHOULD ALLOW MODEST SPEED CONVERGENCE
NEAR THE COAST. WITH THIS IN MIND WILL CONTINUE THE FORECAST OF 30%
POPS FOR WIDELY SCT LATE AFTERNOON/EVENING STORMS SOUTH OF
HILLSBOROUGH AND POLK COUNTIES. UNDER THE "BEST" MOISTURE PROFILE
WILL DRAW A SMALL AREA OF 40% POPS AROUND FORT MYERS AFTER 4PM.
CONVECTIVE DEVELOPMENT FROM TAMPA BAY NORTHWARD ACROSS THE NATURE
COAST AGAIN LOOKS ISOLATED AT BEST. WILL KEEP THE 20% FOR THE I-4
CORRIDOR OF THE STATE...BUT THEN DROP RAIN CHANCES TO A SILENT 10%
NORTH OF PASCO COUNTY. THE DEPTH AND STRENGTH OF THE SYNOPTIC
SUPPRESSION OVER THESE FAR NORTHERN ZONES SIMPLY DOES NOT WARRANT
STORM MENTION IN THE CURRENT FORECAST. CROSS SECTIONAL ANALYSIS FROM
THE GFS AND NAM ALSO SHOW A LAYER OF 315-318K THETA-E AIR BETWEEN
750-700MB THIS AFTERNOON TO THE NORTH OF THE I-4 CORRIDOR. THIS IS A
VERY HOSTILE LAYER FOR ANYTHING BUT ISOLATED DEEP CONVECTION TO
OVERCOME. THESE RAIN CHANCES LIE A BIT ABOVE THE STATISTICAL
GUIDANCE...BUT WELL BELOW THE CLIMO RAIN CHANCES ASSOCIATED WITH AN
EASTERLY FLOW REGIME.
THE LACK OF CONVECTION...EVEN SOUTH...UNTIL VERY LATE IN THE DAY
ALONG WITH THE DEEP LAYER SUPPRESSION SHOULD PROMOTE ANOTHER DAY OF
EXCELLENT DIURNAL MIXING. WOULD EXPECT MANY LOCATIONS TO EASILY
REACH THE LOWER/MIDDLE 90S FOR HIGH TEMPS.
WEDNESDAY/WEDNESDAY NIGHT...UPPER LOW FEATURE IS SHOWN BY ALL
NUMERICAL GUIDANCE MEMBERS TO RETROGRADE OVER THE CENTRAL AND
NORTHERN PORTION OF THE STATE BY EARLY WEDNESDAY MORNING. THIS
FEATURE SHOULD BRING AT LEAST SOME INCREASE IN DEEP LAYER
MOISTURE...ALTHOUGH CERTAINLY NOT GOING TO MAKE THE ATMOSPHERE MOIST
OVERHEAD...BUT RATHER POTENTIALLY NOT QUITE AS HOSTILE TO DEEP
CONVECTION. IN ADDITION TO THE SLIGHTLY BETTER MOISTURE
PROFILES...WE WILL SEE OUR MID-LEVEL TEMPS DROP A FEW DEGREES
ASSOCIATED WITH THE COOL POOL UNDER THE UPPER LOW. THIS SLIGHT TEMP
DROP SHOULD AID THE DECREASE IN STABILITY. INHERITED RAIN CHANCES OF
25-35% NORTH AND 35-50% SOUTH LOOK ON TRACK. THESE NUMBERS AGREE
WELL WITH ECMWF AND MAV STATISTICAL GUIDANCE SOUTH OF TAMPA
BAY...AND ARE A BIT ABOVE THESE NUMBERS FOR THE NORTHERN HALF OF THE
AREA.
WITH THE UPPER LOW IN PLACE OVER THE REGION WED NIGHT AND AN INFLUX
OF DEEP MOISTURE (SHOWN BY BOTH THE ECMWF AND GFS) APPROACHING FROM
THE SOUTH...WILL LEAVE AT LEAST A SMALL CHANCE FOR SHOWERS IN THE
GRIDS. QUITE OFTEN IT IS FAVORABLE TO SEE SHOWERS DEVELOP (EVEN AT
NIGHT) ALONG THESE MOISTURE GRADIENTS.
THURSDAY...UPPER LOW OPENS UP AND LEAVES THE REGION UNDER BROAD
SW TO NE ORIENTED TROUGHING. LOW LEVEL GRADIENT COLLAPSES COMPLETELY
LEAVING A VARIABLE WIND FLOW. THE LACK OF A DEFINED FLOW
REGIME...ADEQUATE MOISTURE AND SOME SYNOPTIC SUPPORT ALOFT WILL LEAD
TO CHANCE 40-50% POPS REGION-WIDE. SHOWERS MAY CERTAINLY BE AROUND
IN THE MORNING...HOWEVER THE GREATEST CHANCE OF SEEING A DOWNPOUR
WILL BE DURING THE AFTERNOON DURING PEAK INSOLATION / HEATING.
&&
.LONG TERM (FRIDAY THROUGH NEXT MONDAY)...
N UPPER LEVEL TROUGH RESIDES DOWN THE EASTERN BOARD INTO FL THROUGH
SUN. THIS TROUGH BEGINS TO SHIFTS OUT OVER THE ATLANTIC MON AS
RIDGING BUILDS IN OVER THE LOWER MISSISSIPPI VALLY/ 09/12Z ECMWF/ OR
ACROSS THE CENTRAL AND EASTERN GULF REGION/ 10/00Z GFS/. AT THE
SURFACE HIGH PRESSURE FROM THE ATLANTIC RIDGES ACROSS FL INTO THE
GULF THROUGH THE WEEKEND AS A FRONTAL BOUNDARY SAGS ACROSS THE SE
U.S TO NORTHERN FL AND BECOMES DIFFUSE. HIGH PRESSURE OVER THE LOWER
GREAT LAKES/MID-ATLANTIC STATES BRIDGES WHATEVER IS LEFT OF THE
BOUNDARY LATE SUN AND ON MON. THE ECMWF AND GFS ARE FAIRLY
CONSISTENT WITH AN AREA OF LOW PRESSURE IN THE SW GULF THAT DRIFTS
WEST OR NW THROUGH THE PERIOD.
THE FORECAST AREA INITIALLY IS UNDER THE INFLUENCE OF LIGHT FLOW
WITH AFTERNOON SEA BREEZES. HOWEVER THIS GIVES WAY TO MORE EASTERLY
FLOW AS THE HIGH BUILDS IN FROM THE NORTH. THE ATMOSPHERE REMAINS
MOIST ENOUGH FOR ISOLATED TO SCATTERED THUNDERSTORMS WITH THE
HIGHEST COVERAGE IN THE AFTERNOONS. RAIN CHANCES WILL BE GENERALLY
IN THE 30 TO 40/50 PERCENT RANGE...FROM NORTH TO SOUTH.
&&
.MARINE...
NOCTURNAL EASTERLY SURGE HAS DROPPED BACK BELOW CAUTIONARY LEVELS
NEAR THE COAST AND WILL DIMINISH OFFSHORE BY SHORTLY AFTER SUNRISE.
AFTER A BRIEF LULL IN THE ELEVATED WINDS THIS AFTERNOON...ANOTHER
EASTERLY SURGE TO CAUTIONARY LEVELS IS ANTICIPATED FOR THE LATE
EVENING AND EARLY MORNING HOURS TONIGHT. THEREAFTER...HIGH PRESSURE
WILL BUILD SOUTH OVER THE EASTERN GULF OF MEXICO AND DIMINISH WINDS
AND SEAS WELL BELOW HEADLINE CRITERIA FOR THE SECOND HALF OF THE
WEEK.
&&
.AVIATION...
10/06Z...PREVAILING VFR FOR THE NEXT 24 HOURS. GENERALLY DRY EXCEPT
FOR ISOLD SHRA/TSRA NEAR PGD/FMY/RSW AFTER 19Z. EASTERLY
WINDS...ROBUST AT TIMES IN THE LATE AFTERNOON-EARLY EVENING.
&&
.FIRE WEATHER...
HIGH PRESSURE TO OUR NORTH KEEPS AN EASTERLY FLOW IN PLACE THROUGH
WEDNESDAY ACROSS THE PENINSULA. WILL BEGIN TO SEE A SLOW INCREASE IN
ATLANTIC MOISTURE ONCE AGAIN DURING THE MIDDLE OF THE WEEK...ALONG
WITH SLOWLY INCREASING CHANCES FOR DIURNAL STORMS FURTHER NORTH INTO
THE TAMPA BAY AND NATURE COAST ZONES. NOT ANTICIPATING ANY CRITICAL
LEVELS OF RELATIVE HUMIDITY THE NEXT SEVERAL DAYS...HOWEVER
DISPERSION INDICES WILL BE ON THE HIGH SIDE...ESPECIALLY FROM THE
I-4 CORRIDOR NORTHWARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 93 75 92 75 / 20 10 30 20
FMY 92 75 91 74 / 40 20 50 30
GIF 92 72 91 72 / 20 10 30 20
SRQ 92 74 91 73 / 30 10 40 30
BKV 92 69 92 70 / 20 10 30 20
SPG 93 78 90 77 / 20 10 30 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...RUDE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1216 PM EDT TUE SEP 10 2013
...MODERATE RISK FOR RIP CURRENTS ALONG THE BEACHES OF NORTH
COASTAL GEORGIA THROUGH THIS EVENING...
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND ACROSS THE AREA THROUGH THE MIDDLE OF
THE WEEK BEFORE A BACKDOOR COLD FRONT DROPS ACROSS THE AREA LATE
FRIDAY AND FRIDAY NIGHT. COOLER HIGH PRESSURE WILL THEN BUILD INTO
THE REGION FROM THE NORTH INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FOR THE REMAINDER OF
THE AFTERNOON HOURS. SHOWERS CONTINUE TO STREAM IN FROM OFF THE
ATLANTIC AND IMPACT PORTIONS OF COASTAL GEORGIA. INCREASED POPS TO
30 PERCENT AND NUDGED CLOUD COVER UP A BIT IN THIS AREA.
OTHERWISE...THE FORECAST IS ON TRACK.
A WELL DEFINED LAND BREEZE COUPLED WITH A NOTICEABLE WIND SURGE
WORKING DOWN THE SOUTH CAROLINA AND GEORGIA COASTS HAS PROMOTED
STRONG SURFACE MOISTURE FLUX CONVERGENCE IN EXCESS OF 20 G/KG/12HR
ACROSS THE COASTAL WATERS AND NORTH COASTAL GEORGIA THIS MORNING.
THIS HAS ALLOWED SOME SHOWER ACTIVITY TO DEVELOP AND MOVE ONSHORE
THIS MORNING. THE H3R AND RAP IDENTIFIED THIS ACTIVITY RATHER WELL
AND MAINTAIN A STREAM OF ISOLATED SHOWERS MOVING ONSHORE FOR MUCH
OF THE DAY...MAINLY FROM HILTON HEAD SOUTH INTO SOUTHEAST GEORGIA.
HAVE ADJUSTED POPS FOR THE LATE MORNING UPDATE TO MATCH GOING
NEAR TERM AND MODEL TRENDS...EXTENDING SLIGHT CHANCE POPS FROM THE
CHARLESTON COUNTY BEACHES INTO SOUTHEAST GEORGIA. SLIGHT CHANCE
POPS ARE ONLY SHOWN THROUGH EARLY AFTERNOON FOR CHARLESTON COUNTY
AND COASTAL COLLETON AS THE BEST SURFACE MOISTURE CONVERGENCE IS
EXPECTED TO REMAIN TO THE SOUTH...BUT THIS MAY NEED TO BE
READJUSTED LATER TODAY ONCE MESOSCALE TRENDS BECOME MORE APPARENT.
OTHERWISE...EXPECT DRY CONDITIONS INLAND TODAY WITH HIGHS RANGING
FROM THE LOWER 90S INLAND TO MID 80S AT THE BEACHES. IT WILL ALSO
BE RATHER BREEZY FROM ROUGHLY TYBEE ISLAND SOUTH TO SAPELO ISLAND
WITH WINDS 15-25 MPH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...SURFACE HIGH PRESSURE WILL CONTINUE NORTH OF THE AREA
WHILE ANOTHER WEAK COASTAL TROUGH DEVELOPS AGAIN. SOME DEEPER
MOISTURE SHIFTING TOWARD THE COAST ON THE NORTH SIDE OF THE UPPER
LOW ALONG WITH THE SURFACE TROUGH SHOULD PRODUCE A BIT MORE IN THE
WAY OF SHOWERS AND POSSIBLY A FEW THUNDERSTORMS OVER THE ATLANTIC
WHICH WILL SHIFT TOWARD THE COAST LATE...MAINLY IN GEORGIA. LOWS
SHOULD REACH THE MID/UPPER 60S INLAND WITH MID 70S AROUND THE
COASTAL AREAS.
WEDNESDAY THROUGH FRIDAY...AN INVERTED UPPER LEVEL TROUGH WILL
RETROGRADE TOWARD THE SOUTHEAST U.S. COAST ON WEDNESDAY...CAUSING
THE EASTERN PERIPHERY OF THE UPPER LEVEL RIDGE OVER THE REGION TO
ERODE. THE INVERTED TROUGH WILL THEN BECOME ABSORBED INTO A LARGER
LONGWAVE TROUGH DIGGING INTO THE EASTERN U.S. ON THURSDAY AND
FRIDAY. MEANWHILE AT THE SURFACE...HIGH PRESSURE WILL BUILD INTO
THE REGION FROM THE NORTH ON WEDNESDAY...WITH ITS AXIS THEN
SHIFTING ACROSS THE AREA ON THURSDAY BEFORE IT BECOMES ESTABLISHED
OVER THE WESTERN ATLANTIC AHEAD OF A NEARING BACKDOOR COLD FRONT
ON FRIDAY.
STRONG SUBSIDENCE AND A LACK OF DEEP MOISTURE WILL PREVENT THE
FORMATION OF ANY CONVECTION INTO FRIDAY MORNING...ALTHOUGH SLIGHTLY
ENHANCED LOW LEVEL CONVERGENCE OFFSHORE COULD SUPPORT A FEW
SHOWERS/THUNDERSTORMS AT TIMES. TRAJECTORIES COULD ALLOW AN ISOLATED
SHOWER/THUNDERSTORM TO ADVECT INLAND ALONG PORTIONS OF THE IMMEDIATE
GEORGIA COAST...BUT OVERALL PROBABILITIES ARE LOW. MOISTURE SHOULD
INCREASE SUFFICIENTLY AHEAD OF THE APPROACHING BACKDOOR COLD FRONT
TO SUPPORT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS FRIDAY
AFTERNOON...WITH THE GREATEST COVERAGE ACROSS SOUTHEAST SOUTH
CAROLINA.
HIGH TEMPERATURES WILL REMAIN AROUND 90 INLAND FROM COOLER COASTAL
AREAS...WITH LOWS RANGING FROM THE MID 60S WELL INLAND TO THE LOWER
AND MID 70S NEAR THE IMMEDIATE COAST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE GUIDANCE REMAINS IN VERY GOOD AGREEMENT FOR MOST OF THE
LONG TERM PERIOD. A LONGWAVE UPPER LEVEL TROUGH WILL PREVAIL OVER
THE EASTERN U.S. THROUGH SATURDAY...BEFORE LIFTING OUT TO THE
NORTHEAST AND ALLOWING A RIDGE AND/OR MORE ZONAL FLOW TO DEVELOP
ALOFT AND PREVAIL INTO EARLY NEXT WEEK. AT THE SURFACE...A BACKDOOR
COLD FRONT WILL DROP THROUGH THE AREA FRIDAY NIGHT...THEN BECOME
NEARLY STATIONARY SOMEWHERE ACROSS FAR SOUTHERN GEORGIA OR NORTHERN
FLORIDA INTO EARLY NEXT WEEK AS IT BECOMES ALIGNED WITH THE FLOW
ALOFT. BEHIND THE FRONT...HIGH PRESSURE WILL BUILD INTO THE REGION
FROM THE NORTH.
AS FOR EXPECTED WEATHER...THERE IS A CHANCE FOR SHOWERS AND
THUNDERSTORMS TO ACCOMPANY THE PASSAGE OF THE FRONT FRIDAY NIGHT
WITH LINGERING MOISTURE BEHIND THE FRONT KEEPING EITHER A SLIGHT
CHANCE OR CHANCE OF SHOWERS IN THE FORECAST FOR SATURDAY. THE
PROXIMITY OF THE FRONT AND LOW LEVEL TRAJECTORIES WILL FAVOR KEEPING
A SLIGHT CHANCE OF PRECIPITATION IN THE FORECAST INTO EARLY NEXT
WEEK FOR PORTIONS OF SOUTHEAST GEORGIA AND FAR SOUTHERN SOUTH
CAROLINA...BUT ESPECIALLY ALONG THE SOUTHEAST GEORGIA COAST.
SIGNIFICANTLY COOLER TEMPERATURES WILL OCCUR FOLLOWING THE PASSAGE
OF THE BACKDOOR COLD FRONT...WITH A NORTHEAST FLOW ONLY SUPPORTING
HIGHS IN THE LOWER TO MID 80S OVER THE WEEKEND. TEMPERATURES WILL
THEN BEGIN TO MODERATE EARLY NEXT WEEK.
&&
.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
VFR. ISOLATED SHOWER ACTIVITY COULD IMPACT KSAV AT JUST ABOUT ANY
TIME THROUGH SUNRISE WEDNESDAY. HOWEVER...MOST ACTIVITY IS
EXPECTED TO REMAIN SOUTH AND EAST OF THE TERMINAL. SHOULD RAIN
OCCUR...IT WOULD BE FAIRLY BRIEF WITH ONLY VERY LIMITED
IMPACTS...IF ANY. WILL NOT INCLUDE A MENTION ATTM GIVEN THE
LIMITED IMPACTS.
EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER
THAN 30 PERCENT CONFIDENCE.
&&
.MARINE...
TODAY...MODEST WIND SURGE IS ONGOING ACROSS THE WATERS THIS
MORNING WITH SPEEDS ROUGHLY 15-20 KT...EXCEPT 15 KT OFF THE
CHARLESTON COUNTY COAST. RAP/H3R SHOW 15-20 KT WINDS HOLDING FOR
MUCH OF THE DAY. SEAS WILL BUILD SLIGHTLY...3-4 FT MOST ZONES.
TONIGHT...HIGH PRESSURE WILL REMAIN NORTH OF THE AREA WITH MOSTLY
EAST WINDS 15 KNOTS OR LESS AND SEAS UP TO 3 FT WITHIN 20 NM AND
UP TO 4 FT IN THE 20-60 NM GEORGIA ZONE.
WEDNESDAY THROUGH SUNDAY...HIGH PRESSURE WILL PERSIST OVER THE
WATERS THROUGH WEDNESDAY NIGHT...MAINTAINING QUIET CONDITIONS. THE
FLOW WILL BECOME MORE SOUTHERLY THURSDAY AND FRIDAY AHEAD OF AN
APPROACHING COLD FRONT...WHICH IS EXPECTED TO DROP ACROSS THE WATERS
LATE FRIDAY AND FRIDAY NIGHT. A STRONG NORTHEAST SURGE WILL THEN
OCCUR IN WAKE OF THE FRONT SATURDAY AND SUNDAY...LIKELY RESULTING IN
SMALL CRAFT ADVISORY CONDITIONS OVER MOST OF THE WATERS. SEAS WILL
GENERALLY BE NO HIGHER THAN 2-4 FT...GREATEST OVER THE OUTER GEORGIA
WATERS...THROUGH FRIDAY BEFORE INCREASING A COUPLE OF FEET OVER THE
WEEKEND AS THE STRONG NORTHEAST FLOW DEVELOPS AND THE FETCH
INCREASES.
RIP CURRENTS...WINDS ARE BEEN AVERAGING 15-20 MPH ALONG THE
GEORGIA BEACHES THIS MORNING WITH OCCASIONAL HIGHER GUSTS. RAP/H3R
KEEP BREEZY CONDITIONS IN PLACE AS ISOLATED SHOWERS MOVE INLAND
THROUGHOUT THE DAY. THIS COUPLED WITH 3 FOOT SEAS AND PERIODS
AROUND 8 SECONDS WILL SUPPORT A LOW-END MODERATE RISK FOR RIP
CURRENTS THROUGH EARLY THIS EVENING. WILL MAINTAIN A LOW RISK FOR
THE SOUTH CAROLINA BEACHES GIVEN THE SLIGHTLY LOWER WIND SPEEDS
THAT ARE EXPECTED...BUT THIS WILL BE MONITORED THROUGHOUT THE DAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
929 AM EDT TUE SEP 10 2013
...MODERATE RISK FOR RIP CURRENTS ALONG THE BEACHES OF NORTH
COASTAL GEORGIA THROUGH THIS EVENING...
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND ACROSS THE AREA THROUGH THE MIDDLE OF
THE WEEK BEFORE A BACKDOOR COLD FRONT DROPS ACROSS THE AREA LATE
FRIDAY AND FRIDAY NIGHT. COOLER HIGH PRESSURE WILL THEN BUILD INTO
THE REGION FROM THE NORTH INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WELL DEFINED LAND BREEZE COUPLED WITH A NOTICEABLE WIND SURGE
WORKING DOWN THE SOUTH CAROLINA AND GEORGIA COASTS HAS PROMOTED
STRONG SURFACE MOISTURE FLUX CONVERGENCE IN EXCESS OF 20 G/KG/12HR
ACROSS THE COASTAL WATERS AND NORTH COASTAL GEORGIA THIS MORNING.
THIS HAS ALLOWED SOME SHOWER ACTIVITY TO DEVELOP AND MOVE ONSHORE
THIS MORNING. THE H3R AND RAP IDENTIFIED THIS ACTIVITY RATHER WELL
AND MAINTAIN A STREAM OF ISOLATED SHOWERS MOVING ONSHORE FOR MUCH
OF THE DAY...MAINLY FROM HILTON HEAD SOUTH INTO SOUTHEAST GEORGIA.
HAVE ADJUSTED POPS FOR THE LATE MORNING UPDATE TO MATCH GOING
NEAR TERM AND MODEL TRENDS...EXTENDING SLIGHT CHANCE POPS FROM THE
CHARLESTON COUNTY BEACHES INTO SOUTHEAST GEORGIA. SLIGHT CHANCE
POPS ARE ONLY SHOWN THROUGH EARLY AFTERNOON FOR CHARLESTON COUNTY
AND COASTAL COLLETON AS THE BEST SURFACE MOISTURE CONVERGENCE IS
EXPECTED TO REMAIN TO THE SOUTH...BUT THIS MAY NEED TO BE
READJUSTED LATER TODAY ONCE MESOSCALE TRENDS BECOME MORE APPARENT.
OTHERWISE...EXPECT DRY CONDITIONS INLAND TODAY WITH HIGHS RANGING
FROM THE LOWER 90S INLAND TO MID 80S AT THE BEACHES. IT WILL ALSO
BE RATHER BREEZY FROM ROUGHLY TYBEE ISLAND SOUTH TO SAPELO ISLAND
WITH WINDS 15-25 MPH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...SURFACE HIGH PRESSURE WILL CONTINUE NORTH OF THE AREA
WHILE ANOTHER WEAK COASTAL TROUGH DEVELOPS AGAIN. SOME DEEPER
MOISTURE SHIFTING TOWARD THE COAST ON THE NORTH SIDE OF THE UPPER
LOW ALONG WITH THE SURFACE TROUGH SHOULD PRODUCE A BIT MORE IN THE
WAY OF SHOWERS AND POSSIBLY A FEW THUNDERSTORMS OVER THE ATLANTIC
WHICH WILL SHIFT TOWARD THE COAST LATE...MAINLY IN GEORGIA. LOWS
SHOULD REACH THE MID/UPPER 60S INLAND WITH MID 70S AROUND THE
COASTAL AREAS.
WEDNESDAY THROUGH FRIDAY...AN INVERTED UPPER LEVEL TROUGH WILL
RETROGRADE TOWARD THE SOUTHEAST U.S. COAST ON WEDNESDAY...CAUSING
THE EASTERN PERIPHERY OF THE UPPER LEVEL RIDGE OVER THE REGION TO
ERODE. THE INVERTED TROUGH WILL THEN BECOME ABSORBED INTO A LARGER
LONGWAVE TROUGH DIGGING INTO THE EASTERN U.S. ON THURSDAY AND
FRIDAY. MEANWHILE AT THE SURFACE...HIGH PRESSURE WILL BUILD INTO
THE REGION FROM THE NORTH ON WEDNESDAY...WITH ITS AXIS THEN
SHIFTING ACROSS THE AREA ON THURSDAY BEFORE IT BECOMES ESTABLISHED
OVER THE WESTERN ATLANTIC AHEAD OF A NEARING BACKDOOR COLD FRONT
ON FRIDAY.
STRONG SUBSIDENCE AND A LACK OF DEEP MOISTURE WILL PREVENT THE
FORMATION OF ANY CONVECTION INTO FRIDAY MORNING...ALTHOUGH SLIGHTLY
ENHANCED LOW LEVEL CONVERGENCE OFFSHORE COULD SUPPORT A FEW
SHOWERS/THUNDERSTORMS AT TIMES. TRAJECTORIES COULD ALLOW AN ISOLATED
SHOWER/THUNDERSTORM TO ADVECT INLAND ALONG PORTIONS OF THE IMMEDIATE
GEORGIA COAST...BUT OVERALL PROBABILITIES ARE LOW. MOISTURE SHOULD
INCREASE SUFFICIENTLY AHEAD OF THE APPROACHING BACKDOOR COLD FRONT
TO SUPPORT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS FRIDAY
AFTERNOON...WITH THE GREATEST COVERAGE ACROSS SOUTHEAST SOUTH
CAROLINA.
HIGH TEMPERATURES WILL REMAIN AROUND 90 INLAND FROM COOLER COASTAL
AREAS...WITH LOWS RANGING FROM THE MID 60S WELL INLAND TO THE LOWER
AND MID 70S NEAR THE IMMEDIATE COAST.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MEDIUM RANGE GUIDANCE REMAINS IN VERY GOOD AGREEMENT FOR MOST OF THE
LONG TERM PERIOD. A LONGWAVE UPPER LEVEL TROUGH WILL PREVAIL OVER
THE EASTERN U.S. THROUGH SATURDAY...BEFORE LIFTING OUT TO THE
NORTHEAST AND ALLOWING A RIDGE AND/OR MORE ZONAL FLOW TO DEVELOP
ALOFT AND PREVAIL INTO EARLY NEXT WEEK. AT THE SURFACE...A BACKDOOR
COLD FRONT WILL DROP THROUGH THE AREA FRIDAY NIGHT...THEN BECOME
NEARLY STATIONARY SOMEWHERE ACROSS FAR SOUTHERN GEORGIA OR NORTHERN
FLORIDA INTO EARLY NEXT WEEK AS IT BECOMES ALIGNED WITH THE FLOW
ALOFT. BEHIND THE FRONT...HIGH PRESSURE WILL BUILD INTO THE REGION
FROM THE NORTH.
AS FOR EXPECTED WEATHER...THERE IS A CHANCE FOR SHOWERS AND
THUNDERSTORMS TO ACCOMPANY THE PASSAGE OF THE FRONT FRIDAY NIGHT
WITH LINGERING MOISTURE BEHIND THE FRONT KEEPING EITHER A SLIGHT
CHANCE OR CHANCE OF SHOWERS IN THE FORECAST FOR SATURDAY. THE
PROXIMITY OF THE FRONT AND LOW LEVEL TRAJECTORIES WILL FAVOR KEEPING
A SLIGHT CHANCE OF PRECIPITATION IN THE FORECAST INTO EARLY NEXT
WEEK FOR PORTIONS OF SOUTHEAST GEORGIA AND FAR SOUTHERN SOUTH
CAROLINA...BUT ESPECIALLY ALONG THE SOUTHEAST GEORGIA COAST.
SIGNIFICANTLY COOLER TEMPERATURES WILL OCCUR FOLLOWING THE PASSAGE
OF THE BACKDOOR COLD FRONT...WITH A NORTHEAST FLOW ONLY SUPPORTING
HIGHS IN THE LOWER TO MID 80S OVER THE WEEKEND. TEMPERATURES WILL
THEN BEGIN TO MODERATE EARLY NEXT WEEK.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS ARE EXPECTED AT KCHS AND KSAV THROUGH 12Z WEDNESDAY.
GIVEN THE DEEP EASTERLY FLOW THERE IS THE POTENTIAL FOR A FEW
SHOWERS/TSTMS TODAY...MAINLY AT KSAV WHERE DEEPER MOISTURE WILL BE
FOUND. HOWEVER...PROBABILITIES ARE TO LOW TO INCLUDE IN THE TAFS
AT THIS TIME.
EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER
THAN 30 PERCENT CONFIDENCE.
&&
.MARINE...
TODAY...MODEST WIND SURGE IS ONGOING ACROSS THE WATERS THIS
MORNING WITH SPEEDS ROUGHLY 15-20 KT...EXCEPT 15 KT OFF THE
CHARLESTON COUNTY COAST. RAP/H3R SHOW 15-20 KT WINDS HOLDING FOR
MUCH OF THE DAY. SEAS WILL BUILD SLIGHTLY...3-4 FT MOST ZONES.
TONIGHT...HIGH PRESSURE WILL REMAIN NORTH OF THE AREA WITH MOSTLY
EAST WINDS 15 KNOTS OR LESS AND SEAS UP TO 3 FT WITHIN 20 NM AND
UP TO 4 FT IN THE 20-60 NM GEORGIA ZONE.
WEDNESDAY THROUGH SUNDAY...HIGH PRESSURE WILL PERSIST OVER THE
WATERS THROUGH WEDNESDAY NIGHT...MAINTAINING QUIET CONDITIONS. THE
FLOW WILL BECOME MORE SOUTHERLY THURSDAY AND FRIDAY AHEAD OF AN
APPROACHING COLD FRONT...WHICH IS EXPECTED TO DROP ACROSS THE WATERS
LATE FRIDAY AND FRIDAY NIGHT. A STRONG NORTHEAST SURGE WILL THEN
OCCUR IN WAKE OF THE FRONT SATURDAY AND SUNDAY...LIKELY RESULTING IN
SMALL CRAFT ADVISORY CONDITIONS OVER MOST OF THE WATERS. SEAS WILL
GENERALLY BE NO HIGHER THAN 2-4 FT...GREATEST OVER THE OUTER GEORGIA
WATERS...THROUGH FRIDAY BEFORE INCREASING A COUPLE OF FEET OVER THE
WEEKEND AS THE STRONG NORTHEAST FLOW DEVELOPS AND THE FETCH
INCREASES.
RIP CURRENTS...WINDS ARE BEEN AVERAGING 15-20 MPH ALONG THE
GEORGIA BEACHES THIS MORNING WITH OCCASIONAL HIGHER GUSTS. RAP/H3R
KEEP BREEZY CONDITIONS IN PLACE AS ISOLATED SHOWERS MOVE INLAND
THROUGHOUT THE DAY. THIS COUPLED WITH 3 FOOT SEAS AND PERIODS
AROUND 8 SECONDS WILL SUPPORT A LOW-END MODERATE RISK FOR RIP
CURRENTS THROUGH EARLY THIS EVENING. WILL MAINTAIN A LOW RISK FOR
THE SOUTH CAROLINA BEACHES GIVEN THE SLIGHTLY LOWER WIND SPEEDS
THAT ARE EXPECTED...BUT THIS WILL BE MONITORED THROUGHOUT THE DAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1006 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 03Z...
* WIND SHIFT TO NORTH/NORTHEAST THURSDAY MORNING.
* GUSTY NORTH/NORTHEAST WINDS THURSDAY AFTERNOON/EVENING. CMS
//DISCUSSION...UPDATED 00Z...
A COLD FRONT CURRENTLY LOCATED ACROSS CENTRAL WI INTO SOUTHERN MN
WILL MOVE SOUTH THIS EVENING REACHING THE TERMINALS BEFORE SUNRISE
THURSDAY MORNING. WESTERLY WINDS UNDER 10KTS WILL SHIFT NORTHWEST
AS THE FRONT ARRIVES AND THEN SHIFT NORTH/NORTHEAST BEHIND THE
FRONT WITH SPEEDS INCREASING TO 10-12KTS. THE GRADIENT WILL
TIGHTEN THURSDAY AFTERNOON AND ESPECIALLY THURSDAY EVENING AS HIGH
PRESSURE BUILDS ACROSS THE NORTHERN PLAINS...WITH GUSTS 15-20KTS
DEVELOPING. BY EVENING...ITS POSSIBLE GUSTS MAY INCREASE INTO THE
20-25KT. IN ADDITION...AS COLDER AIR SPREADS DOWN THE LAKE...MVFR
LAKE EFFECT CLOUDS MAY ALSO DEVELOP THURSDAY EVENING.
ANOTHER WEAK WAVE WILL MOVE EAST ACROSS THE REGION LATER THIS
EVENING INTO THE OVERNIGHT HOURS...WHICH MAY PRODUCE ADDITIONAL
SHRA/TSRA AND EXPECT THEM TO REMAIN SOUTH OF THE TERMINALS...
THOUGH ISOLATED SHRA NOW DEVELOPING NORTH OF THE THE QUAD CITIES
WILL NEED TO BE MONITORED INTO THIS EVENING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH FOR WIND SHIFT...MEDIUM FOR TIMING.
* MEDIUM FOR WIND SPEEDS/GUSTS. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...MVFR POSSIBLE EARLY...THEN DRY/VFR.
* SATURDAY...DRY/VFR.
* SUNDAY...CHANCE OF TSRA.
* MONDAY...DRY/VFR.
* TUESDAY...SLIGHT CHANCE OF TSRA.
&&
.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.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
635 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 00Z...
* WIND SHIFT TO NORTH/NORTHEAST THURSDAY MORNING.
* GUSTY NORTH/NORTHEAST WINDS THURSDAY AFTERNOON/EVENING. CMS
//DISCUSSION...UPDATED 00Z...
A COLD FRONT CURRENTLY LOCATED ACROSS CENTRAL WI INTO SOUTHERN MN
WILL MOVE SOUTH THIS EVENING REACHING THE TERMINALS BEFORE SUNRISE
THURSDAY MORNING. WESTERLY WINDS UNDER 10KTS WILL SHIFT NORTHWEST
AS THE FRONT ARRIVES AND THEN SHIFT NORTH/NORTHEAST BEHIND THE
FRONT WITH SPEEDS INCREASING TO 10-12KTS. THE GRADIENT WILL
TIGHTEN THURSDAY AFTERNOON AND ESPECIALLY THURSDAY EVENING AS HIGH
PRESSURE BUILDS ACROSS THE NORTHERN PLAINS...WITH GUSTS 15-20KTS
DEVELOPING. BY EVENING...ITS POSSIBLE GUSTS MAY INCREASE INTO THE
20-25KT. IN ADDITION...AS COLDER AIR SPREADS DOWN THE LAKE...MVFR
LAKE EFFECT CLOUDS MAY ALSO DEVELOP THURSDAY EVENING.
ANOTHER WEAK WAVE WILL MOVE EAST ACROSS THE REGION LATER THIS
EVENING INTO THE OVERNIGHT HOURS...WHICH MAY PRODUCE ADDITIONAL
SHRA/TSRA AND EXPECT THEM TO REMAIN SOUTH OF THE TERMINALS...
THOUGH ISOLATED SHRA NOW DEVELOPING NORTH OF THE THE QUAD CITIES
WILL NEED TO BE MONITORED INTO THIS EVENING. CMS
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH FOR WIND SHIFT...MEDIUM FOR TIMING.
* MEDIUM FOR WIND SPEEDS/GUSTS. CMS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...MVFR POSSIBLE EARLY...THEN DRY/VFR.
* SATURDAY...DRY/VFR.
* SUNDAY...CHANCE OF TSRA.
* MONDAY...DRY/VFR.
* TUESDAY...SLIGHT CHANCE OF TSRA.
&&
.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.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1040 PM EDT WED SEP 11 2013
.SYNOPSIS...
ISSUED AT 1040 PM EDT WED SEP 11 2013
A COLD FRONT WILL SAG SLOWLY SOUTHWARD THROUGH THE GREAT LAKES
TONIGHT. THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS
THROUGH THE NIGHT AHEAD OF THIS FRONT. 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 WEDNESDAY.
&&
.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 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 737 PM EDT WED SEP 11 2013
OUTFLOW BOUNDARY NEARING KFWA AT ISSUANCE SO STARTED WITH A NW
WIND WITH GUST TO 20 KNOTS. NOT MUCH REFLECTIVITY BUT A VERY BRIEF
SHOWER WITH WIND SHIFT EXPECTED. OTHERWISE ISOLATED SHRA/TSRA
STILL POSSIBLE THIS EVENING AHEAD OF MAIN COLD FRONT STILL TO THE
WEST. DID NOT INCLUDE ANY PCPN MENTION GIVEN THE ISOLATED NATURE
EXPECTED. SOME HI RES GUIDANCE STILL TRYING TO DEVELOP ADDITIONAL
CONVECTION THIS EVENING OVER IL AND HAVE IT RIDING BOUNDARY EAST.
WILL HAVE TO MONITOR FOR POSSIBLE UPDATES. DID ADD SOME SCATTERED
STRATUS IN WAKE OF FRONT WITH LIGHT WINDS AND LINGERING HIGHER
DEWPOINTS. NORTHWEST WIND EXPECTED ON THURSDAY WITH GUSTS TO 20
KNOTS POSSIBLE WITH COOLER AIR BY LATE MORNING AND AFTERNOON.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT FROM THURSDAY MORNING THROUGH LATE
FRIDAY NIGHT FOR INZ003.
MI...BEACH HAZARDS STATEMENT FROM THURSDAY MORNING THROUGH LATE
FRIDAY NIGHT FOR MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 11 AM THURSDAY TO 6 AM EDT SATURDAY
FOR LMZ043-046.
&&
$$
SYNOPSIS...FISHER
SHORT TERM...FISHER
LONG TERM...T
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
741 PM EDT WED SEP 11 2013
.SYNOPSIS...
ISSUED AT 740 PM EDT TUE SEP 10 2013
A COLD FRONT WILL SAG SLOWLY SOUTHWARD THROUGH THE GREAT LAKES
TONIGHT. THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS
THROUGH THE NIGHT AHEAD OF THIS FRONT. 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 WEDNESDAY.
&&
.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 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 737 PM EDT WED SEP 11 2013
OUTFLOW BOUNDARY NEARING KFWA AT ISSUANCE SO STARTED WITH A NW
WIND WITH GUST TO 20 KNOTS. NOT MUCH REFLECTIVITY BUT A VERY BRIEF
SHOWER WITH WIND SHIFT EXPECTED. OTHERWISE ISOLATED SHRA/TSRA
STILL POSSIBLE THIS EVENING AHEAD OF MAIN COLD FRONT STILL TO THE
WEST. DID NOT INCLUDE ANY PCPN MENTION GIVEN THE ISOLATED NATURE
EXPECTED. SOME HI RES GUIDANCE STILL TRYING TO DEVELOP ADDITIONAL
CONVECTION THIS EVENING OVER IL AND HAVE IT RIDING BOUNDARY EAST.
WILL HAVE TO MONITOR FOR POSSIBLE UPDATES. DID ADD SOME SCATTERED
STRATUS IN WAKE OF FRONT WITH LIGHT WINDS AND LINGERING HIGHER
DEWPOINTS. NORTHWEST WIND EXPECTED ON THURSDAY WITH GUSTS TO 20
KNOTS POSSIBLE WITH COOLER AIR BY LATE MORNING AND AFTERNOON.
&&
.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...LASHLEY
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 DES MOINES IA
1152 PM CDT MON SEP 9 2013
.SHORT TERM.../TONIGHT /...
ISSUED AT 324 PM CDT MON SEP 9 2013
MAIN FORECAST CONCERN IS WITH WEAK FRONT EXPECTED TO DIP INTO FAR
NORTHERN IOWA OVERNIGHT TONIGHT. LATEST HOPWRF SUGGEST SOME WEAK
ISOLATED DEVELOPMENT ALONG THE FRONT PAST 05Z TUESDAY IN SOUTHERN
MINNESOTA AND NORTHWEST IOWA. THE HRRR AND 4.0 SPC WRF SUGGEST
SIMILAR TREND...ALTHOUGH SLIGHTLY FURTHER NORTHWEST. THERE IS SOME
WEAK FRONTOGENETICAL FORCING BETWEEN 850MB AND 700MB LATER TONIGHT
INTO EARLY TUESDAY MORNING THAT SNEAKS INTO NORTHWEST IOWA. SO
KEPT SLIGHT POPS GOING ACROSS THE NORTH TONIGHT...BUT HAVE LOW
CONFIDENCE WITH ANY SIGNIFICANT RAINFALL SINCE SHOWERS WILL BE
VERY HIGH BASED. WENT CLOSER TO THE ECMWF FOR LOW TEMPS TONIGHT
WITH THE WAA CONTINUING AHEAD OF THE FRONT.
.LONG TERM.../TUESDAY THROUGH MONDAY/...
ISSUED AT 324 PM CDT MON SEP 9 2013
MAIN FORECAST CONCERNS FOR TUESDAY INT WEDNESDAY REVOLVE AROUND A
COLD FRONTAL PASSAGE. MOST OF THE FORCING WITH THE FRONT SHIFTS
NORTH AND EAST OF THE AREA. WHILE DEEP SHEAR IS UNIMPRESSIVE THERE
IS SOME LOW LEVEL SHEAR COINCIDENT WITH THE FRONT. MODELS CONTINUE
TO SHOW LITTLE IN THE WAY OF RAINFALL AND THAT BEING POST FRONTAL.
THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS WILL COME LATE
AFTERNOON AND EVENING WHEN A SHORT WAVE MOVES ACROSS MAINLY THE
NORTHERN FORECAST AREA AND INTERACTS WITH THE FRONT. SOUNDINGS
SHOW STEEP LAPSE RATES SO WHILE ANY STORMS WOULD BE ISOLATED TO
SCATTERED AT BEST THERE IS SOME POTENTIAL FOR AN ISOLATED WIND
THREAT. THE HEAT WILL STILL BE ON FOR SOUTHEAST PORTIONS OF THE
STATE TOMORROW AND THERE IS SOME CONCERN THAT WITH TWO WARM NIGHTS
NOW AND WHAT WILL BE THE SECOND HOT DAY THERE COULD BE SOME
CUMULATIVE EFFECTS OF PROLONGED HEAT. HOWEVER WITH LONGER NIGHTS
THERE SHOULD BE MORE TIME FOR THE BODY TO RECOVER SO WE WILL
CONTINUE TO HANDLE THE HEAT WITH A SPECIAL WEATHER STATEMENT.
THE FRONT GRADUALLY SHIFTS TO THE SOUTH THROUGH WEDNESDAY FOLLOWED
BY COOLER TEMPS FOR THE REST OF THE WEEK.
FOR THE WEEKEND THE MODELS SUGGEST A SHORTWAVE PUSHING ACROSS THE
NORTHERN PLAINS AGAIN AND POSSIBLY INTO THE UPPER MIDWEST. TIMING
AND STRENGTH OF THE SHORTWAVE ARE STILL IN QUESTION BUT THERE
APPEAR TO BE AT LEAST CHANCES FOR THUNDERSTORMS AND GRIDS CONTINUE
TO REFLECT THESE CHANCES.
&&
.AVIATION...10/06Z
ISSUED AT 1147 PM CDT MON SEP 9 2013
WEAK SURFACE FRONT WILL SETTLE INTO THE STATE OVER THE DURATION OF
THE FORECAST PERIOD. DESPITE THE ARRIVAL OF THE BOUNDARY...
CONDITIONS WILL REMAIN VFR ACROSS THE FORECAST AREA THROUGH
TUESDAY. SOME ISOLATED TO SCATTERED CONVECTION IS EXPECTED TUESDAY
EVENING IN VICINITY OF THE FRONT. WINDS WILL BE LIGHT AND VARIABLE
NEAR THE FRONT WITH SOUTHWEST WINDS SOUTH OF THE BOUNDARY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...FAB/PODRAZIK
LONG TERM...FAB
AVIATION...COGIL
AREA FORECAST DISCUSSION
NWS WICHITA KS
652 PM CDT WED SEP 11 2013
.SYNOPSIS...
ISSUED AT 320 PM CDT WED SEP 11 2013
MORNING UPPER LEVEL DATA ANALYSIS ENDING AT 18Z SHOWS INCREASING
RIDGING OVER THE PACIFIC NORTHWEST WITH A STRENGTHENING DOWNSTREAM
TROUGH OVER THE EASTERN UNITED STATES. SEVERAL DISTURBANCES ARE
NOTED SOUTH OF THE MAIN FLOW PATTERN...ONE JUST WEST OF THE FOUR
CORNERS REGION...A SECOND OVER EASTERN TEXAS...AND A THIRD OVER
THE EAST COAST OF FLORIDA. WATER VAPOR SHOWS A GOOD FLOW OF
MOISTURE REACHING INTO THE HIGH PLAINS...WHICH IS SUPPORTING
PRECIPITATION OVER SAID REGION.
SURFACE AND RADAR DATA SHOWS A SHOWERS AND A FEW THUNDERSTORMS OVER
THE HIGH PLAINS AND ALONG A QUASI-STATIONARY FRONT WHICH EXTENDS
ACROSS SOUTHERN NEBRASKA...SOUTHERN IOWA AND SOUTHERN WISCONSIN.
COOK
&&
.UPDATE...
ISSUED AT 651 PM CDT WED SEP 11 2013
UPDATED THE AVIATION SECTION BELOW FOR THE 00Z TAFS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 320 PM CDT WED SEP 11 2013
SURFACE AND RADAR DATA SHOWS A SHOWERS AND A FEW THUNDERSTORMS
OVER THE HIGH PLAINS AND ALONG A QUASI-STATIONARY FRONT WHICH
EXTENDS ACROSS SOUTHERN NEBRASKA...SOUTHERN IOWA AND SOUTHERN
WISCONSIN.
CONVECTION CONTINUES TO BE THE MAIN SHORT TERM FORECAST PROBLEM.
AT 20Z...CONVECTION HAD DEVELOPED WESTERN AND CENTRAL KANSAS. THIS
IS IN THE MOISTURE PLUME SHOWN ON WATER VAPOR IMAGERY AND NEAR
WHAT THE HRRR RUNS HAVE SHOWN FOR MUCH OF THE DAY. THIS HAS BEEN
INITIALIZED INTO THE FORECAST GRIDS. EXPECT THE FRONT TO CONVECT
AS WELL AS CONVERGENCE AND INSTABILITY INCREASE AND THE CAP
DECREASES THIS EVENING. DEEP LAYER SHEAR CONTINUES TO REMAIN QUITE
UNFAVORABLE FOR ORGANIZED SEVERE WEATHER.
THE FRONT WILL MOVE SOUTH AS A COLD FRONT LATER THIS EVENING AND
STORMS ALONG IT INCREASE. WE CONTINUE TO INCREASE PRECIPITATION
CHANCES IN THE FORECAST AS MOISTURE AND FORCING FIELDS LOOK MORE
FAVORABLE.
AS THE FRONT MOVES SOUTH...THEN SOUTHWEST THROUGH THE FORECAST
AREA...PRECIPITATION CONTINUES ACROSS MUCH OF THE AREA
THURSDAY...AND IS THEN CONFINED ALONG THE FRONT THURSDAY NIGHT.
THIS SHOULD BE MAINLY WEST OF INTERSTATE 135. HIGH PRESSURE BUILDS
INTO THE REGION FRIDAY...FOR THE COOLEST DAY IN A WHILE ACROSS
THE REGION.
COOK
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT WED SEP 11 2013
THE RIDGE OVER THE WESTERN UNITED STATES MOVES ACROSS THE REGION
DURING THE TIME FRAME. AS THIS OCCURS...THUNDERSTORMS ARE POSSIBLE
INTO EARLY THIS COMING WEEK UNTIL THE WARM FRONT /THE COLD FRONT
THAT MOVES THOUGH THE AREA RETURNING NORTH AS A WARM FRONT/ MOVES
THROUGH. BY THE MIDDLE OF NEXT WEEK...THE RIDGING SHOULD CENTER
ITSELF ACROSS THE REGION...AS INDICATED BY THE MEAN OF THE 11.00Z
NAEFS. THIS WILL BRING WARM SOUTHERLY WINDS AND TEMPERATURES WELL
ABOVE NORMAL BACK INTO THE REGION.
COOK
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 651 PM CDT WED SEP 11 2013
A RATHER WET NIGHT ANTICIPATED...AS SCATTERED TO OCCASIONALLY
NUMEROUS SHOWERS/THUNDERSTORMS ARE EXPECTED TO SLOWLY DRIFT SOUTH
ACROSS CENTRAL KS...REACHING SOUTHERN KS BY LATE TONIGHT OR EARLY
THURSDAY. THE CULPRIT IS A SLOW MOVING COLD FRONT APPROACHING FROM
THE NORTH...COMBINED WITH DEEP/RICH MOISTURE. NOT ANTICIPATING
SEVERE WEATHER...ALTHOUGH THE STRONGEST ACTIVITY WILL PRODUCE
GUSTY/ERRATIC WINDS AND LOCALLY VERY HEAVY RAIN. ONLY INCLUDED
TEMPO GROUPS FOR RSL AND SLN IN THE SHORT-TERM...ENVISION
ADDITIONAL TEMPO GROUPS AND/OR PREVAILING TSRA WILL EVENTUALLY BE
NEEDED. WILL ISSUE TIMELY AMENDMENTS WHERE NEEDED.
ADK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 69 83 65 79 / 20 50 30 20
HUTCHINSON 68 81 63 77 / 40 60 30 30
NEWTON 68 82 63 78 / 30 50 30 20
ELDORADO 70 84 64 80 / 20 40 20 10
WINFIELD-KWLD 70 86 67 80 / 10 30 30 20
RUSSELL 67 78 61 73 / 60 70 40 40
GREAT BEND 66 78 62 74 / 50 70 50 40
SALINA 68 83 63 78 / 50 60 30 20
MCPHERSON 67 82 63 77 / 40 60 30 20
COFFEYVILLE 70 88 67 82 / 10 20 20 10
CHANUTE 69 86 64 81 / 30 40 10 10
IOLA 70 85 63 80 / 30 40 10 10
PARSONS-KPPF 69 88 65 82 / 20 30 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1116 PM MDT MON SEP 9 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 237 PM MDT MON SEP 9 2013
AS OF 3 PM CDT...2 PM MDT...SKIES ACROSS THE TRI-STATE AREA WERE
MOSTLY CLEAR WITH THE EXCEPTION OF SOME PATCHES OF DAYTIME CUMULUS.
TEMPERATURES HAVE RISEN INTO THE LOW 90S TO NEAR 100 IN A FEW SPOTS
ACROSS RED WILLOW...DECATUR...NORTON AND GRAHAM COUNTIES. WINDS WERE
GENERALLY FROM THE SOUTH AT 10 TO 20 MPH WITH GUSTS 25 TO 30 MPH.
DEWPOINTS WERE ON A SLOW DECLINE THIS AFTERNOON. A COLD FRONT WAS
LOCATED ACROSS NORTHEAST COLORADO AND SOUTHWEST NEBRASKA. AN AREA OF
LOW PRESSURE WAS DRAPED ACROSS THE AREA...STRETCHING FROM SOUTHWEST
NEBRASKA TO THE COLORADO FRONT RANGE. FIRE WEATHER HAS BECOME A
CONCERN THIS AFTERNOON AND WILL BE ADDRESSED IN A FIRE WEATHER
SECTION BELOW.
FOR THIS AFTERNOON AND TONIGHT...SURFACE CONVERGENCE IS PROJECTED TO
INCREASE ALONG THE COLD FRONT...ALLOWING SOME ISOLATED TO WIDELY
SCATTERED THUNDERSTORMS TO DEVELOP. IN ADDITION...CONVECTION
DEVELOPING OVER THE ROCKIES MAY ORGANIZE AND MOVE EAST INTO THE
REGION FROM THE LATEST RUNS OF THE HRRR MODEL. MOST OTHER MODELS
HOLD ALL PRECIPITATION OFF AND KEEP IT TO THE NORTHWEST OF THE
FORECAST AREA. A STRONG STORM OR TWO IS POSSIBLE WITH DAMAGING
WINDS AND SMALL HAIL AS THE MAIN THREAT. HOWEVER...INSTABILITY IS
NOT AS HIGH AS NEEDED FOR A MORE WIDESPREAD THREAT OF SEVERE
WEATHER. THE FRONT SHOULD MOVE TO THE SOUTH DURING THE OVERNIGHT
HOURS...BRINGING COOLER TEMPERATURES...MORE MOISTURE TO THE AIR
AND A WIND SHIFT. LOW TEMPERATURES WILL VARY ACROSS THE REGION
WITH LOW 60S ACROSS EAST COLORADO AND MID 60S TO NEAR 70 FOR THE
REST OF THE AREA.
FOR TOMORROW...THE COLD FRONT IS EXPECTED TO STALL ACROSS THE AREA.
IN ADDITION TO THE FRONT...AN UPPER LEVEL DISTURBANCE WILL APPROACH
FROM THE WEST...PROVIDING EXTRA LIFT FOR SHOWER AND THUNDERSTORM
DEVELOPMENT. CHANCES FOR PRECIPITATION WILL BE MUCH HIGHER DURING
THE LATE AFTERNOON TO EVENING HOURS FOR A LARGER AREA. TEMPERATURES
BEHIND THE FRONT WILL BE NOTICEABLY COOLER WITH HIGHS IN THE UPPER
70S TO LOW 80S. ALONG AND AHEAD OF THE FRONT...TEMPERATURES WILL BE
WARM WITH HIGHS IN THE MID 80S TO LOW 90S WHERE DAYTIME HEATING
LASTS LONGER BEFORE CLOUDS AND CONVECTIVE ACTIVITY DEVELOPS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 1249 PM MDT MON SEP 9 2013
PATTERN CHANGE WILL OCCUR DURING THIS PERIOD AS THE UPPER RIDGE
WHICH HAS BEEN DOMINANT WILL SHIFT TO THE SOUTHEASTERN CONUS AND
TROUGH WHICH HAS BEEN OVER THE WEST WILL MOVE TO THE CENTRAL AND
NORTHERN ROCKIES. THIS WILL BRING NEAR TO BELOW NORMAL
TEMPERATURES AND OCCASIONAL CHANCES FOR PRECIPITATION TO THE AREA.
FIRST CHANCE FOR RAIN WILL OCCUR TUESDAY NIGHT WITH SHORTWAVE
TROUGH MOVING UP IN THE SOUTHWEST FLOW ALOFT. ANOTHER SHORTWAVE IS
FORECAST ON THURSDAY. BOTH SYSTEMS WILL HAVE PLENTIFUL MOISTURE TO
WORK WITH A TROPICAL CONNECTION TO THE BAJA. RAIN CHANCES CONTINUE
THROUGH THE WEEKEND AS THE UPPER LOW OPENS UP AND EVENTUALLY GETS
ENTRAINED IN THE NORTHERN STREAM. LATE IN THE PERIOD AN UPPER RIDGE
WILL BEGIN TO REBUILD BEHIND THE DEPARTING SYSTEM SIGNALING THE
RETURN OF WARM AND DRY CONDITIONS EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1116 PM MDT MON SEP 9 2013
VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK TERMINALS. WITH MOSTLY CLEAR SKIES AND WINDS BECOMING
LIGHT BY SUNRISE I COULDNT RULE OUT SHALLOW FOG OR ISOLATED
STRATUS WITH BL MOISTURE INCREASING NORTHEAST OF FRONT. AT THIS
POINT CONFIDENCE IS VERY LOW IN OCCURRENCE AT EITHER TERMINAL...AND
GUIDANCE CONTINUES TO KEEP CONDITIONS CLEAR...SO I WILL NOT ADD
DURING THIS ISSUANCE. WE COULD CONTINUE TO SEE A FEW BRIEF GUSTS
IMMEDIATELY BEHIND A FRONT THAT IS CURRENTLY JUST NORTH OF KMCK
EXTENDING EAST OF KGLD. OTHER THAN BRIEF GUSTS EARLY WINDS SHOULD
REMAIN BELOW 12KT WITH GRADIENT FAIRLY WEAK. THUNDERSTORMS WILL BE
POSSIBLE TUE AFTERNOON/EVENING...HOWEVER CONFIDENCE WAS TOO LOW TO
ADD MENTION FOR EITHER TERMINAL.
&&
.FIRE WEATHER...
ISSUED AT 237 PM MDT MON SEP 9 2013
NEAR CRITICAL FIRE WEATHER CONDITIONS HAVE DEVELOPED ACROSS PORTIONS
OF THE REGION THIS AFTERNOON. HOT TEMPERATURES AND LOW DEWPOINTS
HAVE LEAD TO RELATIVE HUMIDITIES DROPPING OFF INTO THE 15-25 PERCENT
RANGE. WINDS HAVE BEEN GUSTY AND A FEW LOCATIONS WERE BARELY MEETING
CRITERIA. HOWEVER...WHETHER OR NOT THE CONDITIONS WOULD LAST THE
FULL THREE HOURS TO MEET WARNING CRITERIA HAS BEEN PROBLEMATIC AS
THE WINDS HAVE BEEN BOUNCING UP AND DOWN THIS AFTERNOON. IN
ADDITION...A SLIGHT RISE IN DEWPOINTS FROM SOUTH TO NORTH HAS BEEN
NOTED AS A MORE MOIST AIR MASS ADVECTS IN FROM THE SOUTH. AS A
RESULT...CONFIDENCE WAS NOT QUITE HIGH ENOUGH TO GO AHEAD AND
ISSUE A RED FLAG WARNING FOR REDWILLOW...HITCHCOCK...DECATUR...
HOXIE...SHERIDAN...THOMAS....ST FRANCIS AND SHERMAN COUNTIES. IF
IT BECOMES APPARENT THAT WINDS WILL STAY UP...A SHORT DURATION RED
FLAG WARNING MAY BE REQUIRED. WILL UPDATE THE FIRE WEATHER
FORECAST TO REFLECT THE LATEST TRENDS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...RRH
LONG TERM...024
AVIATION...DR
FIRE WEATHER...RRH
AREA FORECAST DISCUSSION
NWS JACKSON KY
135 AM EDT TUE SEP 10 2013
.UPDATE...
ISSUED AT 135 AM EDT TUE SEP 10 2013
MADE SOME MINOR TWEAKS TO GET THE FIRST 12 HOURS OF THE FORECAST TO
BETTER REFLECT CURRENT CONDITIONS AND MODEL TRENDS. THE REST OF THE
FORECAST IS ON TRACK AND NO NEW ZONE FORECASTS WILL BE ISSUED.
UPDATE ISSUED AT 747 PM EDT MON SEP 9 2013
AS ANTICIPATED SHOWERS HAVE ALL DISSIPATED...LEAVING BEHIND MAINLY
CLEAR SKIES FOR THE REMAINDER OF THE NIGHT. WILL UPDATE FORECAST TO
REFLECT LESS CLOUD COVER OVERNIGHT AS WELL AS ADJUSTING LOWS DOWN A
TAD TOWARDS WHAT WE SAW LAST NIGHT. THIS SHOULD YIELD ANOTHER NIGHT
OF VALLEY FOG WITH DEWPOINTS ACTUALLY RUNNING A FEW DEGREES HIGHER
THAN YESTERDAY AT THIS TIME.
UPDATE ISSUED AT 553 PM EDT MON SEP 9 2013
A FEW SHOWERS AND THUNDERSTORMS HAVE DEVELOPED NORTHWARD INTO SOUTH
CENTRAL KENTUCKY...BASICALLY EASTERN WAYNE COUNTY/MCCREARY
COUNTY...NORTH INTO EASTERN PULASKI COUNTY. BASED ON SATELLITE...THIS
ACTIVITY SHOULD REMAIN CONFINED TO THESE AREAS OVER THE NEXT HOUR OR
TWO BEFORE WEAKENING AND DISSIPATING AS THE SUN GOES DOWN. THIS
SHOULD ALLOW ACTIVITY TO DIE OFF BY ROUGHLY 00Z. UPDATED NDFD GRIDS
TO REFINE THE POPS...BUT WILL NOT ISSUE A NEW ZFP WITH THE ISOLATED
NATURE OF THIS ACTIVITY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 340 PM EDT MON SEP 9 2013
18Z SFC ANALYSIS SHOWS WEAK HIGH PRESSURE IN PLACE OVER EAST KENTUCKY
WITH LOW PRESSURE FOUND OFF TO THE NORTHWEST. A DOME OF HIGHER
HEIGHTS IS BUILDING OVER THE REGION AND THIS HAS HELPED TO CONTRIBUTE
TO A VERY WARM LATE SUMMER DAY ACROSS EAST KENTUCKY WITH TEMPS
APPROACHING 90 DEGREES. PRETTY HIGH DEWPOINTS IN THE MID AND UPPER
60S ARE MAKING IT FEEL EVEN WARMER...IN ADDITION TO PROVIDING AN
UNCOMFORTABLE HUMIDITY LEVEL. HERE AT PEAK HEATING...A FEW OF THE CU
HAVE MANAGED TO GET DEEP ENOUGH THAT A SHOWER OR THUNDERSTORM WILL
BE POSSIBLE...MAINLY ALONG OUR SOUTHERN AND EASTERN BORDERS.
OTHERWISE...SKIES ARE MOSTLY CLEAR AND THE CU SHALLOW.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
DEPICTING A MODERATELY STRONG RIDGE PUSHING INTO THE LOWER OHIO
VALLEY AND ACROSS TO THE MID ATLANTIC COAST. THIS RIDGE WILL NOT BE
COMPLETELY FREE OF ENERGY OR PROHIBITIVELY WARM AT MID LEVELS...
THOUGH...SO ITS ABILITY TO PUT A CAP ON CONVECTION WILL BE LIMITED.
IN THIS KIND OF ENVIRONMENT...THE MESOSCALE WILL DOMINATE FOR WEATHER
SPECIFICS SO HAVE FAVORED A MORE SUBDUED VERSION OF THE NAM12 WITH
INPUT FROM THE HRRR IN THE NEAR TERM. ALSO FAVORED AN ENHANCED
DIURNAL TRACE FOR POPS.
SENSIBLE WEATHER WILL FEATURE MORE IN THE WAY OF PERSISTENCE THROUGH
WEDNESDAY MORNING. AT NIGHT...WE CAN EXPECT A FADE OUT OF THE
DAYTIME CLOUDS AND PATCHY FOG...LOCALLY DENSE IN THE VALLEYS...
DEVELOPING BY DAWN. HIGH DEWPOINTS WILL KEEP THERE FROM BEING MUCH OF
A RIDGE TO VALLEY TEMP SPLIT BOTH TONIGHT AND TUESDAY NIGHT. FOR THE
DAY TUESDAY...IT WILL BE ANOTHER WARM AND HUMID ONE WITH A SMALL
CHANCE OF SHOWERS AND THUNDERSTORMS DEVELOPING WITH PEAK HEATING...
DESPITE THE RIDGING ALOFT.
JUMP STARTED THE TD AND WIND GRIDS WITH CONSSHORT DATA THROUGH 12Z
TUESDAY AND THE CONSALL THEREAFTER. FOR TEMPERATURES...PREFERRED THE
OBS DATABASE AS A GUIDE FOR THE DIURNAL CURVE AND MODIFIED CONSALL
FOR MAX AND MIN TEMPS...TEMPERING THE TOO WARM GRIDDED MOS HIGHS ON
TUESDAY WITH SOME RAW MODEL OUTPUT. AS FOR POPS...ENDED UP PRETTY
CLOSE TO AN AVERAGE OF THE GUIDANCE THROUGH THE SHORT TERM PERIOD.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 245 PM EDT MON SEP 9 2013
THE MODELS ALL AGREE THAT WEDNESDAY AND THURSDAY WILL BE THE ACTIVE
DAYS OF THE EXTENDED PERIOD. A SERIES OF WEATHER SYSTEMS...BOTH
SURFACE FRONTS AND TROUGHS OF LOW PRESSURE ALOFT...WILL BRING
SHOWERS AND THUNDERSTORMS TO EASTERN KENTUCKY DURING THE MIDDLE OF
THE WEEK. THE MORE POTENT WEATHER MAKER WILL BE A SIGNIFICANT COLD
FRONT THAT IS EXPECTED TO MOVE ACROSS THE AREA THURSDAY INTO
THURSDAY EVENING. THE FRONT WILL LIKELY BE SLOWED UP A BIT BY THE
HIGH TERRAIN OF EAST KENTUCKY FOR IT FINALLY EXITS THE AREA THURSDAY
EVENING. ONCE THE FRONT IS OUT OF THE AREA...A LARGE AND WELL
DEFINED AREA OF HIGH PRESSURE WILL MIGRATE SOUTHWARD OUT OF CANADA
AND THEN THE OHIO VALLEY...BEFORE FINALLY SETTLING OVER THE EASTERN
CONUS FROM FRIDAY ONWARD. THE AIR MASS ASSOCIATED WITH THIS RIDGE
WILL BRING VERY UNSEASONABLY COOL TEMPERATURES TO THE REGION FRIDAY
AND SATURDAY. HIGHS ON FRIDAY AND SATURDAY WILL ONLY BE TOPPING OUT
IN THE LOW TO MID 70S...BEFORE REBOUNDING A BIT ON SUNDAY...WHEN
HIGHS IN THE UPPER 70S TO AROUND 80 ARE EXPECTED. THE
GFS...ECMWF...AND NAEFS MODELS ALL BEGIN THE PERIOD WITH A LARGE
TROUGH OF LOW PRESSURE ALOFT ACROSS THE EASTERN CONUS...WITH A
STRONG RIDGE OF HIGH PRESSURE SETTING UP OUT WEST. THE MIDDLE OF THE
WEEK WILL FEATURE WARM AND WET WEATHER...WHILE THE END OF THE WEEK
AND THE UPCOMING WEEKEND WILL BE VERY COOL AND DRY AND FALL LIKE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 135 AM EDT TUE SEP 10 2013
VFR CONDITIONS WILL GIVE WAY TO MVFR/IFR FOG DEVELOPMENT IN THE
VALLEYS OVERNIGHT. SIMILAR TO THE LAST FEW NIGHTS...THIS FOG WILL
ONCE AGAIN IMPACT THE TAF SITES. WENT WITH SIMILAR FOG AS LAST NIGHT
IN THE TAFS SINCE CONDITIONS REMAIN VERY SIMILAR AND WOULD EXPECT
SIMILAR RESULTS. FOG WILL BURN OFF BY 13Z TOMORROW MORNING...LEAVING
BEHIND VFR CONDITIONS FOR THE REMAINDER OF THE DAY. AN ISOLATED
SHOWER OR THUNDERSTORM WILL BE POSSIBLE AGAIN...BUT NOT ENOUGH
CONFIDENCE TO INCLUDE IN THE FORECAST AT THIS TIME.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JJ
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
409 PM EDT TUE SEP 10 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 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 320 PM EDT TUE SEP 10 2013
IFR CONDITIONS AT KCMX IN FOG/STRATUS WILL GRADUALLY LIFT TO MVFR
LATER THIS AFTERNOON WITH INCREASING WESTERLY FLOW AND DAYTIME
HEATING...ALTHOUGH UPSLOPE FLOW WILL LIMIT IMPROVEMENT. KIWD/KSAW
HAVE ALREADY IMPROVED TO VFR THIS AFTN. BAND OF SHRA OVER WRN UPR
MI/N CNTRL WI MAY HOLD TOGETHER TO GIVE KSAW SOME SHRA LATER THIS
AFTERNOON. VFR CONDITIONS SHOULD CONTINUE INTO EARLY EVENING AT KIWD
AND KSAW...BUT EXPECT MORE FOG REDEVELOPING BY LATE EVENING/OVERNIGHT
UNDER LIGHT WINDS AND PARTIAL CLEARING WITH LIFR TO VLIFR EXPECTED AT
ALL SITES.
&&
.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...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
327 PM EDT TUE SEP 10 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 527 AM EDT TUE SEP 10 2013
PER WATER VAPOR IMAGERY AND RUC ANALYSIS...THE MID LEVEL LOW THAT
WAS OVER THE PACIFIC NW FOR SEVERAL DAYS IS NOW AN OPEN WAVE OVER
THE DAKOTAS INTO SRN MANITOBA. AT THE SFC...A LOW PRES TROF EXTENDS
FROM NW MN ACROSS LAKE SUPERIOR.
INITIALLY...WILL HAVE TO DEAL WITH SOME FOG EARLY THIS MORNING WHICH
WILL BE LOCALLY DENSE. WITH WESTERLY WINDS S OF THE SFC TROF
INCREASING A BIT OVER THE NEXT FEW HRS...FOG SHOULD CLEAR OUT OF THE
AREAS THAT SEE DOWNSLOPING WITH A W WIND. WHERE WINDS UPSLOPE...FOG
WILL DISSIPATE BY LATE MORNING UNDER A COMBINATION OF DAYTIME
HEATING AND MECHANICAL MIXING WITH INCREASING LOW-LEVEL WINDS. AS OF
09Z...KMQT RADAR DOES NOT SHOW ANY PCPN ACROSS THE FCST AREA.
HOWEVER...RIGHT ENTRANCE OF WSW TO ENE ORIENTED UPPER JET ASSOCIATED
WITH DAKOTAS/MANITOBA SHORTWAVE IS SUPPORTING A BKN BAND OF SHRA
FROM THE NEBRASKA TO NE MN. SOME OF THESE SHRA AND PERHAPS A TSRA
MAY AFFECT MAINLY WRN UPPER MI THIS MORNING AS UPPER JET TRANSLATES
EASTWARD. THIS AFTN...ATTENTION TURNS TO THE ERN FCST AREA AS
DAYTIME HEATING/LOW-LEVEL MOISTURE LEAD TO MLCAPE INCREASING TO
500-1000J/KG. WESTERLY LOW-LEVEL WINDS WILL LEAD TO ENHANCED
CONVERGENCE ACROSS INTERIOR ERN UPPER MI AS WINDS VEER NEAR LAKE
SUPERIOR AND BACK NEAR LAKE MICHIGAN AS LAKE BREEZE COMPONENT
DEVELOPS. EXPECT SCT SHRA/TSRA TO DEVELOP ROUGHLY ALONG A LINE
MIDWAY BTWN ESCANABA/MUNISING E TO NEWBERRY. ISOLATED SHRA/TSRA MAY
DEVELOP AS FAR W AS TOWARD KSAW/KIMT. AS FOR TEMPS...WITH INCREASING
W WINDS...DOWNSLOPE AREAS WILL SEE LOW CLOUDS CLEAR OUT THIS
MORNING. THIS WILL LIKELY LEAD TO A HOT/HUMID DAY OVER SCNTRL UPPER
MI AS DOWNSLOPING ENHANCES THE ALREADY VERY WARM START TO THE DAY.
MIXING TO 850-800MB ON NAM/GFS FCST SOUNDINGS SUGGESTS POTENTIAL FOR
MAX TEMPS INTO THE LOW/MID 90S OVER THE SCNTRL. SOME CLOUD COVER
THIS AFTN MAY LIMIT MIXING DEPTH...BUT DOWNSLOPING COULD STILL
SUPPORT TEMPS OVER 90F. FOR NOW...RAISED MAX TEMPS TO THE UPPER 80S
OVER THE SCNTRL WITH LOWER 80S EXTENDING INTO THE INTERIOR ERN FCST
AREA. ELSEWHERE...70S SHOULD BE THE RULE...THOUGH TEMPS MAY TOP 80F
WHERE W WINDS DOWNSLOPE.
AS UPPER JET CONTINUES TO TRANSLATE EASTWARD TONIGHT...RIGHT
ENTRANCE OF JET WILL AID A RIBBON OF LOW-MIDLEVEL FRONTOGENESIS
ACROSS THE UPPER LAKES. CONSENSUS OF MODEL GUIDANCE SHOWS THIS
FORCING SUPPORTING A BAND OF SHRA STREAKING ENE ACROSS WI TOWARD THE
STRAITS. THERE IS SOME UNCERTAINTY IN EXACTLY WHERE THIS RELATIVELY
NARROW BAND OF PCPN WILL BE LOCATED...BUT BULK OF GUIDANCE SUGGESTS
THE FAR SCNTRL/SE FCST AREA WILL BE CLIPPED. OPTED TO INCLUDE LOW
CHC POPS IN THAT AREA. SOME OF THE HIGHER RESOLUTION MODEL GUIDANCE
ALSO INDICATE LATE AFTN SHRA OVER NRN MN MAKING IT ACROSS LAKE
SUPERIOR AND AFFECTING WRN UPPER MI THIS EVENING. INCLUDED SCHC POPS
OVER THE W THIS EVENING.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 525 AM EDT TUE SEP 10 2013
OUR ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THURSDAY. WE WILL
FINALLY DISPLACE THE 500MB TROUGH THAT HAS BEEN BEEN SET UP ACROSS
THE NORTHERN TIER OF CENTRAL AND EASTERN U.S. FRIDAY NIGHT THROUGH
THE START OF THE UPCOMING WEEKEND...AS THE RIDGE MOVES OVERHEAD.
STARTING OUT AT 12Z WEDNESDAY...THE SFC LOW OVER N ONTARIO WILL BE
DRAGGING A COLD FRONT ACROSS MN AND FAR W LAKE SUPERIOR. MAINLY
AFTERNOON CONVECTION IS EXPECTED AS THE COLD FRONT DRAGS ACROSS THE
AREA...WITH THE ASSIST OF DAYTIME HEATING. ML CAPE VALUES TO OUT
AROUND 500J/KG OR LESS WEDNESDAY AFTERNOON OVER THE E HALF TO
TWO-THIRDS OF UPPER MI...AND QUICKLY DIMINISH TOWARD 00Z.
LARGE HIGH PRESSURE OVER S CENTRAL CANADA AND THE N PLAINS WEDNESDAY
NIGHT/THURSDAY MORNING WILL THEN BE THE MAIN INFLUENCE ON OUR
WEATHER FOR THE END OF THE WEEK. STRONG N WINDS /SLOWED DOWN APPROX
3-6HRS/ STILL LOOK REASONABLE...USHERING IN COLD AIR ACROSS LAKE
SUPERIOR AND UPPER MI.
THE COLDEST AIR OVERHEAD LOOKS TO BE SET UP AROUND 06Z FRIDAY...WITH
850MB TEMPS FALLING TO 1 TO -4C /COOLEST OFF THE ECMWF/. WHILE THERE
REMAINS THE POTENTIAL FOR FROST DEVELOPMENT...WITH THE COLD AIR
OVERHEAD AND PW VALUES FALLING TO AROUND 45 PERCENT OF NORMAL
/0.3-0.4IN/...N-NNE WINDS OFF LAKE SUPERIOR MAY STILL BE BRINGING
LOW CLOUDS AND EVEN LAKE ENHANCED RAIN SHOWERS/DRIZZLE ON N-NNE
WINDS OFF LAKE SUPERIOR.
AS FOR THE FROST POTENTIAL FOR FRIDAY NIGHT INTO SATURDAY
MORNING...WITH THE SFC HIGH SLIDING TO S CENTRAL AND EASTERN UPPER
MI...THE LIGHTEST WINDS WILL BE THERE. PW VALUES WILL NOT BE QUITE
AS LOW...IN THE 0.4-0.5 RANGE OR AROUND 50 PERCENT OF NORMAL. THESE
SLIGHTLY HIGHER PW VALUES AND 850MB TEMPS AROUND 5C WILL BE OFFSET
BY THE LIGHTER WINDS AND CLEAR SKY...WITH SIMILAR TEMP READINGS
EXPECTED ACROSS CENTRAL AREAS.
LOOK FOR A TEMPORARILY BREAK TO THE COOL WEATHER ON SATURDAY AND TO
A LESSER EXTENT SUNDAY...AS HIGHS TOP OUT IN THE 60S. THIS IS STILL
4-10F BELOW NORMAL FOR THIS TIME OF YEAR. WAA ON WSW WINDS SATURDAY
SHOULD ALLOW 850MB TEMPS TO RISE TO 8-10C. SUNDAY WILL BE A
DIFFERENT STORY...AS A SHORTWAVE LOOKS TO PUT AN END TO OUR DRY
WEATHER ON SUNDAY. SLOWED DOWN OUR INITIAL BLEND FOR THE EXTENDED
PERIOD...BUT LOOKING AT THE LATEST 10/00Z GFS/ECMWF RUNS. IN
FACT...THE SCATTERED POPS FOR SATURDAY NIGHT THROUGH SUNDAY LOOK TO
BE IN JEOPARDY IF THE 10/00Z GFS IS CORRECT...AS IT KEEPS US DRY
THROUGH AT LEAST NEXT MONDAY. WILL WAIT TO SEE HOW THE NEXT COUPLE
RUNS PLAY UP THIS FEATURE BEFORE MAKING TOO MANY CHANGES TO THE
ONGOING FCST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 320 PM EDT TUE SEP 10 2013
IFR CONDITIONS AT KCMX IN FOG/STRATUS WILL GRADUALLY LIFT TO MVFR
LATER THIS AFTERNOON WITH INCREASING WESTERLY FLOW AND DAYTIME
HEATING...ALTHOUGH UPSLOPE FLOW WILL LIMIT IMPROVEMENT. KIWD/KSAW
HAVE ALREADY IMPROVED TO VFR THIS AFTN. BAND OF SHRA OVER WRN UPR
MI/N CNTRL WI MAY HOLD TOGETHER TO GIVE KSAW SOME SHRA LATER THIS
AFTERNOON. VFR CONDITIONS SHOULD CONTINUE INTO EARLY EVENING AT KIWD
AND KSAW...BUT EXPECT MORE FOG REDEVELOPING BY LATE EVENING/OVERNIGHT
UNDER LIGHT WINDS AND PARTIAL CLEARING WITH LIFR TO VLIFR EXPECTED AT
ALL SITES. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 318 AM EDT TUE SEP 10 2013
PATCHY TO AREAS OF FOG SHOULD SLOWLY DISSIPATE THIS MORNING. LOW
PRESSURE EXITING E LAKE SUPERIOR TODAY 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 THURSDAY MORNING
THROUGH EARLY FRIDAY MORNING...WITH NW 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...ROLFSON
LONG TERM...KF
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
746 AM EDT TUE SEP 10 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 527 AM EDT TUE SEP 10 2013
PER WATER VAPOR IMAGERY AND RUC ANALYSIS...THE MID LEVEL LOW THAT
WAS OVER THE PACIFIC NW FOR SEVERAL DAYS IS NOW AN OPEN WAVE OVER
THE DAKOTAS INTO SRN MANITOBA. AT THE SFC...A LOW PRES TROF EXTENDS
FROM NW MN ACROSS LAKE SUPERIOR.
INITIALLY...WILL HAVE TO DEAL WITH SOME FOG EARLY THIS MORNING WHICH
WILL BE LOCALLY DENSE. WITH WESTERLY WINDS S OF THE SFC TROF
INCREASING A BIT OVER THE NEXT FEW HRS...FOG SHOULD CLEAR OUT OF THE
AREAS THAT SEE DOWNSLOPING WITH A W WIND. WHERE WINDS UPSLOPE...FOG
WILL DISSIPATE BY LATE MORNING UNDER A COMBINATION OF DAYTIME
HEATING AND MECHANICAL MIXING WITH INCREASING LOW-LEVEL WINDS. AS OF
09Z...KMQT RADAR DOES NOT SHOW ANY PCPN ACROSS THE FCST AREA.
HOWEVER...RIGHT ENTRANCE OF WSW TO ENE ORIENTED UPPER JET ASSOCIATED
WITH DAKOTAS/MANITOBA SHORTWAVE IS SUPPORTING A BKN BAND OF SHRA
FROM THE NEBRASKA TO NE MN. SOME OF THESE SHRA AND PERHAPS A TSRA
MAY AFFECT MAINLY WRN UPPER MI THIS MORNING AS UPPER JET TRANSLATES
EASTWARD. THIS AFTN...ATTENTION TURNS TO THE ERN FCST AREA AS
DAYTIME HEATING/LOW-LEVEL MOISTURE LEAD TO MLCAPE INCREASING TO
500-1000J/KG. WESTERLY LOW-LEVEL WINDS WILL LEAD TO ENHANCED
CONVERGENCE ACROSS INTERIOR ERN UPPER MI AS WINDS VEER NEAR LAKE
SUPERIOR AND BACK NEAR LAKE MICHIGAN AS LAKE BREEZE COMPONENT
DEVELOPS. EXPECT SCT SHRA/TSRA TO DEVELOP ROUGHLY ALONG A LINE
MIDWAY BTWN ESCANABA/MUNISING E TO NEWBERRY. ISOLATED SHRA/TSRA MAY
DEVELOP AS FAR W AS TOWARD KSAW/KIMT. AS FOR TEMPS...WITH INCREASING
W WINDS...DOWNSLOPE AREAS WILL SEE LOW CLOUDS CLEAR OUT THIS
MORNING. THIS WILL LIKELY LEAD TO A HOT/HUMID DAY OVER SCNTRL UPPER
MI AS DOWNSLOPING ENHANCES THE ALREADY VERY WARM START TO THE DAY.
MIXING TO 850-800MB ON NAM/GFS FCST SOUNDINGS SUGGESTS POTENTIAL FOR
MAX TEMPS INTO THE LOW/MID 90S OVER THE SCNTRL. SOME CLOUD COVER
THIS AFTN MAY LIMIT MIXING DEPTH...BUT DOWNSLOPING COULD STILL
SUPPORT TEMPS OVER 90F. FOR NOW...RAISED MAX TEMPS TO THE UPPER 80S
OVER THE SCNTRL WITH LOWER 80S EXTENDING INTO THE INTERIOR ERN FCST
AREA. ELSEWHERE...70S SHOULD BE THE RULE...THOUGH TEMPS MAY TOP 80F
WHERE W WINDS DOWNSLOPE.
AS UPPER JET CONTINUES TO TRANSLATE EASTWARD TONIGHT...RIGHT
ENTRANCE OF JET WILL AID A RIBBON OF LOW-MIDLEVEL FRONTOGENESIS
ACROSS THE UPPER LAKES. CONSENSUS OF MODEL GUIDANCE SHOWS THIS
FORCING SUPPORTING A BAND OF SHRA STREAKING ENE ACROSS WI TOWARD THE
STRAITS. THERE IS SOME UNCERTAINTY IN EXACTLY WHERE THIS RELATIVELY
NARROW BAND OF PCPN WILL BE LOCATED...BUT BULK OF GUIDANCE SUGGESTS
THE FAR SCNTRL/SE FCST AREA WILL BE CLIPPED. OPTED TO INCLUDE LOW
CHC POPS IN THAT AREA. SOME OF THE HIGHER RESOLUTION MODEL GUIDANCE
ALSO INDICATE LATE AFTN SHRA OVER NRN MN MAKING IT ACROSS LAKE
SUPERIOR AND AFFECTING WRN UPPER MI THIS EVENING. INCLUDED SCHC POPS
OVER THE W THIS EVENING.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 525 AM EDT TUE SEP 10 2013
OUR ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THURSDAY. WE WILL
FINALLY DISPLACE THE 500MB TROUGH THAT HAS BEEN BEEN SET UP ACROSS
THE NORTHERN TIER OF CENTRAL AND EASTERN U.S. FRIDAY NIGHT THROUGH
THE START OF THE UPCOMING WEEKEND...AS THE RIDGE MOVES OVERHEAD.
STARTING OUT AT 12Z WEDNESDAY...THE SFC LOW OVER N ONTARIO WILL BE
DRAGGING A COLD FRONT ACROSS MN AND FAR W LAKE SUPERIOR. MAINLY
AFTERNOON CONVECTION IS EXPECTED AS THE COLD FRONT DRAGS ACROSS THE
AREA...WITH THE ASSIST OF DAYTIME HEATING. ML CAPE VALUES TO OUT
AROUND 500J/KG OR LESS WEDNESDAY AFTERNOON OVER THE E HALF TO
TWO-THIRDS OF UPPER MI...AND QUICKLY DIMINISH TOWARD 00Z.
LARGE HIGH PRESSURE OVER S CENTRAL CANADA AND THE N PLAINS WEDNESDAY
NIGHT/THURSDAY MORNING WILL THEN BE THE MAIN INFLUENCE ON OUR
WEATHER FOR THE END OF THE WEEK. STRONG N WINDS /SLOWED DOWN APPROX
3-6HRS/ STILL LOOK REASONABLE...USHERING IN COLD AIR ACROSS LAKE
SUPERIOR AND UPPER MI.
THE COLDEST AIR OVERHEAD LOOKS TO BE SET UP AROUND 06Z FRIDAY...WITH
850MB TEMPS FALLING TO 1 TO -4C /COOLEST OFF THE ECMWF/. WHILE THERE
REMAINS THE POTENTIAL FOR FROST DEVELOPMENT...WITH THE COLD AIR
OVERHEAD AND PW VALUES FALLING TO AROUND 45 PERCENT OF NORMAL
/0.3-0.4IN/...N-NNE WINDS OFF LAKE SUPERIOR MAY STILL BE BRINGING
LOW CLOUDS AND EVEN LAKE ENHANCED RAIN SHOWERS/DRIZZLE ON N-NNE
WINDS OFF LAKE SUPERIOR.
AS FOR THE FROST POTENTIAL FOR FRIDAY NIGHT INTO SATURDAY
MORNING...WITH THE SFC HIGH SLIDING TO S CENTRAL AND EASTERN UPPER
MI...THE LIGHTEST WINDS WILL BE THERE. PW VALUES WILL NOT BE QUITE
AS LOW...IN THE 0.4-0.5 RANGE OR AROUND 50 PERCENT OF NORMAL. THESE
SLIGHTLY HIGHER PW VALUES AND 850MB TEMPS AROUND 5C WILL BE OFFSET
BY THE LIGHTER WINDS AND CLEAR SKY...WITH SIMILAR TEMP READINGS
EXPECTED ACROSS CENTRAL AREAS.
LOOK FOR A TEMPORARILY BREAK TO THE COOL WEATHER ON SATURDAY AND TO
A LESSER EXTENT SUNDAY...AS HIGHS TOP OUT IN THE 60S. THIS IS STILL
4-10F BELOW NORMAL FOR THIS TIME OF YEAR. WAA ON WSW WINDS SATURDAY
SHOULD ALLOW 850MB TEMPS TO RISE TO 8-10C. SUNDAY WILL BE A
DIFFERENT STORY...AS A SHORTWAVE LOOKS TO PUT AN END TO OUR DRY
WEATHER ON SUNDAY. SLOWED DOWN OUR INITIAL BLEND FOR THE EXTENDED
PERIOD...BUT LOOKING AT THE LATEST 10/00Z GFS/ECMWF RUNS. IN
FACT...THE SCATTERED POPS FOR SATURDAY NIGHT THROUGH SUNDAY LOOK TO
BE IN JEOPARDY IF THE 10/00Z GFS IS CORRECT...AS IT KEEPS US DRY
THROUGH AT LEAST NEXT MONDAY. WILL WAIT TO SEE HOW THE NEXT COUPLE
RUNS PLAY UP THIS FEATURE BEFORE MAKING TOO MANY CHANGES TO THE
ONGOING FCST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 745 AM EDT TUE SEP 10 2013
LIFR/IFR CONDITIONS IN FOG/STRATUS WILL START THE FCST AT
KIWD/KCMX/KSAW. THEN...INCREASING WESTERLY FLOW AND DAYTIME HEATING
WILL WORK TO MIX OUT THE LOW-LEVEL MOISTURE THIS MORNING INTO THE
EARLY AFTN. UPSLOPE NATURE OF THE FLOW AT KCMX SHOULD RESULT IN
IMPROVEMENT BEING SLOWEST THERE THAN AT KIWD/KSAW...BUT ALL
TERMINALS WILL BE VFR BY MID AFTN. BAND OF SHRA OVER CNTRL MN INTO
NW WI MAY HOLD TOGETHER AND AFFECT KIWD/KCMX THIS MORNING. VFR
CONDITIONS SHOULD CONTINUE TONIGHT...BUT WILL NEED TO WATCH FOR THE
POTENTIAL OF FOG REDEVELOPMENT...ESPECIALLY IF SKIES BECOME MOSTLY
CLEAR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 318 AM EDT TUE SEP 10 2013
PATCHY TO AREAS OF FOG SHOULD SLOWLY DISSIPATE THIS MORNING. LOW
PRESSURE EXITING E LAKE SUPERIOR TODAY 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 THURSDAY MORNING
THROUGH EARLY FRIDAY MORNING...WITH NW 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...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
528 AM EDT TUE SEP 10 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 527 AM EDT TUE SEP 10 2013
PER WATER VAPOR IMAGERY AND RUC ANALYSIS...THE MID LEVEL LOW THAT
WAS OVER THE PACIFIC NW FOR SEVERAL DAYS IS NOW AN OPEN WAVE OVER
THE DAKOTAS INTO SRN MANITOBA. AT THE SFC...A LOW PRES TROF EXTENDS
FROM NW MN ACROSS LAKE SUPERIOR.
INITIALLY...WILL HAVE TO DEAL WITH SOME FOG EARLY THIS MORNING WHICH
WILL BE LOCALLY DENSE. WITH WESTERLY WINDS S OF THE SFC TROF
INCREASING A BIT OVER THE NEXT FEW HRS...FOG SHOULD CLEAR OUT OF THE
AREAS THAT SEE DOWNSLOPING WITH A W WIND. WHERE WINDS UPSLOPE...FOG
WILL DISSIPATE BY LATE MORNING UNDER A COMBINATION OF DAYTIME
HEATING AND MECHANICAL MIXING WITH INCREASING LOW-LEVEL WINDS. AS OF
09Z...KMQT RADAR DOES NOT SHOW ANY PCPN ACROSS THE FCST AREA.
HOWEVER...RIGHT ENTRANCE OF WSW TO ENE ORIENTED UPPER JET ASSOCIATED
WITH DAKOTAS/MANITOBA SHORTWAVE IS SUPPORTING A BKN BAND OF SHRA
FROM THE NEBRASKA TO NE MN. SOME OF THESE SHRA AND PERHAPS A TSRA
MAY AFFECT MAINLY WRN UPPER MI THIS MORNING AS UPPER JET TRANSLATES
EASTWARD. THIS AFTN...ATTENTION TURNS TO THE ERN FCST AREA AS
DAYTIME HEATING/LOW-LEVEL MOISTURE LEAD TO MLCAPE INCREASING TO
500-1000J/KG. WESTERLY LOW-LEVEL WINDS WILL LEAD TO ENHANCED
CONVERGENCE ACROSS INTERIOR ERN UPPER MI AS WINDS VEER NEAR LAKE
SUPERIOR AND BACK NEAR LAKE MICHIGAN AS LAKE BREEZE COMPONENT
DEVELOPS. EXPECT SCT SHRA/TSRA TO DEVELOP ROUGHLY ALONG A LINE
MIDWAY BTWN ESCANABA/MUNISING E TO NEWBERRY. ISOLATED SHRA/TSRA MAY
DEVELOP AS FAR W AS TOWARD KSAW/KIMT. AS FOR TEMPS...WITH INCREASING
W WINDS...DOWNSLOPE AREAS WILL SEE LOW CLOUDS CLEAR OUT THIS
MORNING. THIS WILL LIKELY LEAD TO A HOT/HUMID DAY OVER SCNTRL UPPER
MI AS DOWNSLOPING ENHANCES THE ALREADY VERY WARM START TO THE DAY.
MIXING TO 850-800MB ON NAM/GFS FCST SOUNDINGS SUGGESTS POTENTIAL FOR
MAX TEMPS INTO THE LOW/MID 90S OVER THE SCNTRL. SOME CLOUD COVER
THIS AFTN MAY LIMIT MIXING DEPTH...BUT DOWNSLOPING COULD STILL
SUPPORT TEMPS OVER 90F. FOR NOW...RAISED MAX TEMPS TO THE UPPER 80S
OVER THE SCNTRL WITH LOWER 80S EXTENDING INTO THE INTERIOR ERN FCST
AREA. ELSEWHERE...70S SHOULD BE THE RULE...THOUGH TEMPS MAY TOP 80F
WHERE W WINDS DOWNSLOPE.
AS UPPER JET CONTINUES TO TRANSLATE EASTWARD TONIGHT...RIGHT
ENTRANCE OF JET WILL AID A RIBBON OF LOW-MIDLEVEL FRONTOGENESIS
ACROSS THE UPPER LAKES. CONSENSUS OF MODEL GUIDANCE SHOWS THIS
FORCING SUPPORTING A BAND OF SHRA STREAKING ENE ACROSS WI TOWARD THE
STRAITS. THERE IS SOME UNCERTAINTY IN EXACTLY WHERE THIS RELATIVELY
NARROW BAND OF PCPN WILL BE LOCATED...BUT BULK OF GUIDANCE SUGGESTS
THE FAR SCNTRL/SE FCST AREA WILL BE CLIPPED. OPTED TO INCLUDE LOW
CHC POPS IN THAT AREA. SOME OF THE HIGHER RESOLUTION MODEL GUIDANCE
ALSO INDICATE LATE AFTN SHRA OVER NRN MN MAKING IT ACROSS LAKE
SUPERIOR AND AFFECTING WRN UPPER MI THIS EVENING. INCLUDED SCHC POPS
OVER THE W THIS EVENING.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 525 AM EDT TUE SEP 10 2013
OUR ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THURSDAY. WE WILL
FINALLY DISPLACE THE 500MB TROUGH THAT HAS BEEN BEEN SET UP ACROSS
THE NORTHERN TIER OF CENTRAL AND EASTERN U.S. FRIDAY NIGHT THROUGH
THE START OF THE UPCOMING WEEKEND...AS THE RIDGE MOVES OVERHEAD.
STARTING OUT AT 12Z WEDNESDAY...THE SFC LOW OVER N ONTARIO WILL BE
DRAGGING A COLD FRONT ACROSS MN AND FAR W LAKE SUPERIOR. MAINLY
AFTERNOON CONVECTION IS EXPECTED AS THE COLD FRONT DRAGS ACROSS THE
AREA...WITH THE ASSIST OF DAYTIME HEATING. ML CAPE VALUES TO OUT
AROUND 500J/KG OR LESS WEDNESDAY AFTERNOON OVER THE E HALF TO
TWO-THIRDS OF UPPER MI...AND QUICKLY DIMINISH TOWARD 00Z.
LARGE HIGH PRESSURE OVER S CENTRAL CANADA AND THE N PLAINS WEDNESDAY
NIGHT/THURSDAY MORNING WILL THEN BE THE MAIN INFLUENCE ON OUR
WEATHER FOR THE END OF THE WEEK. STRONG N WINDS /SLOWED DOWN APPROX
3-6HRS/ STILL LOOK REASONABLE...USHERING IN COLD AIR ACROSS LAKE
SUPERIOR AND UPPER MI.
THE COLDEST AIR OVERHEAD LOOKS TO BE SET UP AROUND 06Z FRIDAY...WITH
850MB TEMPS FALLING TO 1 TO -4C /COOLEST OFF THE ECMWF/. WHILE THERE
REMAINS THE POTENTIAL FOR FROST DEVELOPMENT...WITH THE COLD AIR
OVERHEAD AND PW VALUES FALLING TO AROUND 45 PERCENT OF NORMAL
/0.3-0.4IN/...N-NNE WINDS OFF LAKE SUPERIOR MAY STILL BE BRINGING
LOW CLOUDS AND EVEN LAKE ENHANCED RAIN SHOWERS/DRIZZLE ON N-NNE
WINDS OFF LAKE SUPERIOR.
AS FOR THE FROST POTENTIAL FOR FRIDAY NIGHT INTO SATURDAY
MORNING...WITH THE SFC HIGH SLIDING TO S CENTRAL AND EASTERN UPPER
MI...THE LIGHTEST WINDS WILL BE THERE. PW VALUES WILL NOT BE QUITE
AS LOW...IN THE 0.4-0.5 RANGE OR AROUND 50 PERCENT OF NORMAL. THESE
SLIGHTLY HIGHER PW VALUES AND 850MB TEMPS AROUND 5C WILL BE OFFSET
BY THE LIGHTER WINDS AND CLEAR SKY...WITH SIMILAR TEMP READINGS
EXPECTED ACROSS CENTRAL AREAS.
LOOK FOR A TEMPORARILY BREAK TO THE COOL WEATHER ON SATURDAY AND TO
A LESSER EXTENT SUNDAY...AS HIGHS TOP OUT IN THE 60S. THIS IS STILL
4-10F BELOW NORMAL FOR THIS TIME OF YEAR. WAA ON WSW WINDS SATURDAY
SHOULD ALLOW 850MB TEMPS TO RISE TO 8-10C. SUNDAY WILL BE A
DIFFERENT STORY...AS A SHORTWAVE LOOKS TO PUT AN END TO OUR DRY
WEATHER ON SUNDAY. SLOWED DOWN OUR INITIAL BLEND FOR THE EXTENDED
PERIOD...BUT LOOKING AT THE LATEST 10/00Z GFS/ECMWF RUNS. IN
FACT...THE SCATTERED POPS FOR SATURDAY NIGHT THROUGH SUNDAY LOOK TO
BE IN JEOPARDY IF THE 10/00Z GFS IS CORRECT...AS IT KEEPS US DRY
THROUGH AT LEAST NEXT MONDAY. WILL WAIT TO SEE HOW THE NEXT COUPLE
RUNS PLAY UP THIS FEATURE BEFORE MAKING TOO MANY CHANGES TO THE
ONGOING FCST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 125 AM EDT TUE SEP 10 2013
WITH ABUNDANT LOW LEVEL MOISTURE OVER THE AREA...VLIFR CONDITIONS
SHOULD PERSIST AT SAW/CMX OVERNIGHT INTO THE MORNING HRS. CONDITIONS
MAY BRIEFLY IMPROVE AT SAW AS SCT SHRA AND POSSIBLY A TSRA MOVE
THROUGH OVERNIGHT. MVFR CIGS AT IWD ARE ALSO EXPECTED TO GIVE WAY TO
IFR CIGS OVERNIGHT AS WINDS VEER LIGHT WRLY. ONLY GRADUAL
IMPROVEMENT IS EXPECTED BY MIDDAY WITH DAYTIME MIXING AND MODEST DRY
ADVECTION WITH INCREASING WRLY FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 318 AM EDT TUE SEP 10 2013
PATCHY TO AREAS OF FOG SHOULD SLOWLY DISSIPATE THIS MORNING. LOW
PRESSURE EXITING E LAKE SUPERIOR TODAY 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 THURSDAY MORNING
THROUGH EARLY FRIDAY MORNING...WITH NW 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...ROLFSON
LONG TERM...KF
AVIATION...JLB
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
526 AM EDT TUE SEP 10 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 419 PM EDT MON SEP 9 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A MID LEVEL LOW OVER NE
MT. LOW IS WEAKENING/OPENING UP ON WATER VAPOR LOOP/ANALYSIS AND IS
FCST TO MOVE E THROUGH THE NRN PLAINS STATES TONIGHT. ASSOC SFC LOW
NOW OVER SW MN IS IN TURN FCST TO LIFT NE ACROSS THE FCST AREA
TONIGHT WITH APPROACH OF NRN PLAINS SHORTWAVE. STRONG WAA/ISENTROPIC
LIFT AHEAD OF FRONTAL BOUNDARY AS IT LIFTS FM SRN WI TOWARD SCNTRL
UPR MI THIS EVENING WILL PROVIDE FOCUS FOR ANOTHER ROUND OF
CONVECTION TONIGHT WITH THE POTENTIAL FOR STRONG TO POSSIBLY SVR
STORMS.
TONIGHT...BIGGEST THING GOING AGAINST SVR WX TONIGHT WILL BE LACK OF
SFC-BASED INSTABILITY FM TODAY DUE TO THICK CLOUDS PERSISTING OVER
THE AREA FM EARLIER MCS OVER THE NRN PLAINS. EVEN SO...COMBINATION
OF STRENGTHING LOW-LVL JET...INCREASING WAA/ISENTROPIC LIFT AND
ADVANCE OF WARM FRONTAL BOUNDARY TOWARD SCNTRL FCST AREA WILL ALLOW
FOR INCREASING ELEVATED INSTABILITY (NAM AND RUC SHOW ELEVATED CAPES
IN EXCESS OF 2000 J/KG THIS EVENING) AND DEEP LAYER SHEAR TO 45-50
KT WHICH COULD BRING POTENTIAL FOR STRONG TO POSSIBLY SVR
STORMS...WITH THE BEST THREAT FOR SVR OVER SCNTRL MI AND SE UPR MI
IN CLOSER PROXIMITY TO ADVANCING WARM FRONT. GIVEN LACK OF SFC-BASED
INSTABILITY...THERE MAY BE MORE OF A THREAT OF ELEVATED STORMS WITH
LARGE HAIL PERHAPS BEING THE BIGGER THREAT FOR OUR AREA. WILL
CONTINUE TO MENTION STRONG TO SEVERE STORMS IN THE HWO WITH THE BEST
THREAT OF HEAVY RAINFALL ACROSS NRN UPR MI AND THE KEWEENAW
PENINSULA. MODEL QPF STILL SUGGESTS THE KEWEENAW PENINSULA AND ERN
UPR MI WILL HAVE BEST CHC FOR HEAVY RAINFALL TONIGHT. LOOK FOR A
GENERAL DIMINISHING TREND IN CONVECTION OVERNIGHT (AFT 06Z) AS
LOW-LVL JET VEERS FM SW TO A MORE WRLY DIRECTION.
DENSE FOG HAS BEEN OBSERVED OVER THE KEWEENAW PENINSULA AND LAKE
SUPERIOR THIS AFTERNOON AND WOULD EXPECT FOG TO CONTINUE INTO THIS
EVENING WITH SHRA MOVING OVER THE AREA AND ONSHORE E-SE FLOW
PERSISTING. EXPECT PATCHY FOG TO MOVE ONSHORE TO NRN ZONES LATE
TONIGHT AS WIND SHIFTS N-NW BEHIND SFC TROUGH.
TUESDAY...THERE COULD BE SOME LINGERING UPSLOPE DZ IN THE MORNING
OVER NRN ZONES AS LOW-LVLS REMAIN MOIST. SOME ISOLD SHRA ARE ALSO
POSSIBLE MAINLY OVER SCNTRL AND ERN SECTIONS OF THE CWA UNTIL
LINGERING SFC BOUNDARY SAGS SE OF THE AREA LATE IN THE DAY.
PERSISTENT CLOUDS OVER THE AREA WILL RESULT IN HIGH TEMPS RANGING
FROM THE 60S NEAR LAKE SUPERIOR IN ONSHORE FLOW TO THE MID 70S
SCNTRL AND EAST ALONG FRONTAL BOUNDARY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 525 AM EDT TUE SEP 10 2013
OUR ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THURSDAY. WE WILL
FINALLY DISPLACE THE 500MB TROUGH THAT HAS BEEN BEEN SET UP ACROSS
THE NORTHERN TIER OF CENTRAL AND EASTERN U.S. FRIDAY NIGHT THROUGH
THE START OF THE UPCOMING WEEKEND...AS THE RIDGE MOVES OVERHEAD.
STARTING OUT AT 12Z WEDNESDAY...THE SFC LOW OVER N ONTARIO WILL BE
DRAGGING A COLD FRONT ACROSS MN AND FAR W LAKE SUPERIOR. MAINLY
AFTERNOON CONVECTION IS EXPECTED AS THE COLD FRONT DRAGS ACROSS THE
AREA...WITH THE ASSIST OF DAYTIME HEATING. ML CAPE VALUES TO OUT
AROUND 500J/KG OR LESS WEDNESDAY AFTERNOON OVER THE E HALF TO
TWO-THIRDS OF UPPER MI...AND QUICKLY DIMINISH TOWARD 00Z.
LARGE HIGH PRESSURE OVER S CENTRAL CANADA AND THE N PLAINS WEDNESDAY
NIGHT/THURSDAY MORNING WILL THEN BE THE MAIN INFLUENCE ON OUR
WEATHER FOR THE END OF THE WEEK. STRONG N WINDS /SLOWED DOWN APPROX
3-6HRS/ STILL LOOK REASONABLE...USHERING IN COLD AIR ACROSS LAKE
SUPERIOR AND UPPER MI.
THE COLDEST AIR OVERHEAD LOOKS TO BE SET UP AROUND 06Z FRIDAY...WITH
850MB TEMPS FALLING TO 1 TO -4C /COOLEST OFF THE ECMWF/. WHILE THERE
REMAINS THE POTENTIAL FOR FROST DEVELOPMENT...WITH THE COLD AIR
OVERHEAD AND PW VALUES FALLING TO AROUND 45 PERCENT OF NORMAL
/0.3-0.4IN/...N-NNE WINDS OFF LAKE SUPERIOR MAY STILL BE BRINGING
LOW CLOUDS AND EVEN LAKE ENHANCED RAIN SHOWERS/DRIZZLE ON N-NNE
WINDS OFF LAKE SUPERIOR.
AS FOR THE FROST POTENTIAL FOR FRIDAY NIGHT INTO SATURDAY
MORNING...WITH THE SFC HIGH SLIDING TO S CENTRAL AND EASTERN UPPER
MI...THE LIGHTEST WINDS WILL BE THERE. PW VALUES WILL NOT BE QUITE
AS LOW...IN THE 0.4-0.5 RANGE OR AROUND 50 PERCENT OF NORMAL. THESE
SLIGHTLY HIGHER PW VALUES AND 850MB TEMPS AROUND 5C WILL BE OFFSET
BY THE LIGHTER WINDS AND CLEAR SKY...WITH SIMILAR TEMP READINGS
EXPECTED ACROSS CENTRAL AREAS.
LOOK FOR A TEMPORARILY BREAK TO THE COOL WEATHER ON SATURDAY AND TO
A LESSER EXTENT SUNDAY...AS HIGHS TOP OUT IN THE 60S. THIS IS STILL
4-10F BELOW NORMAL FOR THIS TIME OF YEAR. WAA ON WSW WINDS SATURDAY
SHOULD ALLOW 850MB TEMPS TO RISE TO 8-10C. SUNDAY WILL BE A
DIFFERENT STORY...AS A SHORTWAVE LOOKS TO PUT AN END TO OUR DRY
WEATHER ON SUNDAY. SLOWED DOWN OUR INITIAL BLEND FOR THE EXTENDED
PERIOD...BUT LOOKING AT THE LATEST 10/00Z GFS/ECMWF RUNS. IN
FACT...THE SCATTERED POPS FOR SATURDAY NIGHT THROUGH SUNDAY LOOK TO
BE IN JEOPARDY IF THE 10/00Z GFS IS CORRECT...AS IT KEEPS US DRY
THROUGH AT LEAST NEXT MONDAY. WILL WAIT TO SEE HOW THE NEXT COUPLE
RUNS PLAY UP THIS FEATURE BEFORE MAKING TOO MANY CHANGES TO THE
ONGOING FCST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 125 AM EDT TUE SEP 10 2013
WITH ABUNDANT LOW LEVEL MOISTURE OVER THE AREA...VLIFR CONDITIONS
SHOULD PERSIST AT SAW/CMX OVERNIGHT INTO THE MORNING HRS. CONDITIONS
MAY BRIEFLY IMPROVE AT SAW AS SCT SHRA AND POSSIBLY A TSRA MOVE
THROUGH OVERNIGHT. MVFR CIGS AT IWD ARE ALSO EXPECTED TO GIVE WAY TO
IFR CIGS OVERNIGHT AS WINDS VEER LIGHT WRLY. ONLY GRADUAL
IMPROVEMENT IS EXPECTED BY MIDDAY WITH DAYTIME MIXING AND MODEST DRY
ADVECTION WITH INCREASING WRLY FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 318 AM EDT TUE SEP 10 2013
PATCHY TO AREAS OF FOG SHOULD SLOWLY DISSIPATE THIS MORNING. LOW
PRESSURE EXITING E LAKE SUPERIOR TODAY 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 THURSDAY MORNING
THROUGH EARLY FRIDAY MORNING...WITH NW 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...KF
AVIATION...JLB
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
318 AM EDT TUE SEP 10 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 419 PM EDT MON SEP 9 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A MID LEVEL LOW OVER NE
MT. LOW IS WEAKENING/OPENING UP ON WATER VAPOR LOOP/ANALYSIS AND IS
FCST TO MOVE E THROUGH THE NRN PLAINS STATES TONIGHT. ASSOC SFC LOW
NOW OVER SW MN IS IN TURN FCST TO LIFT NE ACROSS THE FCST AREA
TONIGHT WITH APPROACH OF NRN PLAINS SHORTWAVE. STRONG WAA/ISENTROPIC
LIFT AHEAD OF FRONTAL BOUNDARY AS IT LIFTS FM SRN WI TOWARD SCNTRL
UPR MI THIS EVENING WILL PROVIDE FOCUS FOR ANOTHER ROUND OF
CONVECTION TONIGHT WITH THE POTENTIAL FOR STRONG TO POSSIBLY SVR
STORMS.
TONIGHT...BIGGEST THING GOING AGAINST SVR WX TONIGHT WILL BE LACK OF
SFC-BASED INSTABILITY FM TODAY DUE TO THICK CLOUDS PERSISTING OVER
THE AREA FM EARLIER MCS OVER THE NRN PLAINS. EVEN SO...COMBINATION
OF STRENGTHING LOW-LVL JET...INCREASING WAA/ISENTROPIC LIFT AND
ADVANCE OF WARM FRONTAL BOUNDARY TOWARD SCNTRL FCST AREA WILL ALLOW
FOR INCREASING ELEVATED INSTABILITY (NAM AND RUC SHOW ELEVATED CAPES
IN EXCESS OF 2000 J/KG THIS EVENING) AND DEEP LAYER SHEAR TO 45-50
KT WHICH COULD BRING POTENTIAL FOR STRONG TO POSSIBLY SVR
STORMS...WITH THE BEST THREAT FOR SVR OVER SCNTRL MI AND SE UPR MI
IN CLOSER PROXIMITY TO ADVANCING WARM FRONT. GIVEN LACK OF SFC-BASED
INSTABILITY...THERE MAY BE MORE OF A THREAT OF ELEVATED STORMS WITH
LARGE HAIL PERHAPS BEING THE BIGGER THREAT FOR OUR AREA. WILL
CONTINUE TO MENTION STRONG TO SEVERE STORMS IN THE HWO WITH THE BEST
THREAT OF HEAVY RAINFALL ACROSS NRN UPR MI AND THE KEWEENAW
PENINSULA. MODEL QPF STILL SUGGESTS THE KEWEENAW PENINSULA AND ERN
UPR MI WILL HAVE BEST CHC FOR HEAVY RAINFALL TONIGHT. LOOK FOR A
GENERAL DIMINISHING TREND IN CONVECTION OVERNIGHT (AFT 06Z) AS
LOW-LVL JET VEERS FM SW TO A MORE WRLY DIRECTION.
DENSE FOG HAS BEEN OBSERVED OVER THE KEWEENAW PENINSULA AND LAKE
SUPERIOR THIS AFTERNOON AND WOULD EXPECT FOG TO CONTINUE INTO THIS
EVENING WITH SHRA MOVING OVER THE AREA AND ONSHORE E-SE FLOW
PERSISTING. EXPECT PATCHY FOG TO MOVE ONSHORE TO NRN ZONES LATE
TONIGHT AS WIND SHIFTS N-NW BEHIND SFC TROUGH.
TUESDAY...THERE COULD BE SOME LINGERING UPSLOPE DZ IN THE MORNING
OVER NRN ZONES AS LOW-LVLS REMAIN MOIST. SOME ISOLD SHRA ARE ALSO
POSSIBLE MAINLY OVER SCNTRL AND ERN SECTIONS OF THE CWA UNTIL
LINGERING SFC BOUNDARY SAGS SE OF THE AREA LATE IN THE DAY.
PERSISTENT CLOUDS OVER THE AREA WILL RESULT IN HIGH TEMPS RANGING
FROM THE 60S NEAR LAKE SUPERIOR IN ONSHORE FLOW TO THE MID 70S
SCNTRL AND EAST ALONG FRONTAL BOUNDARY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 419 PM EDT MON SEP 9 2013
A WEAK HIGH PRESSURE RIDGE WILL SLIDE OVER THE AREA ON TUESDAY
NIGHT BEHIND THE EXITING LOW PRESSURE SYSTEM. WITH THE AREA STILL
UNDER THE RIGHT REAR OF THE UPPER JET...A WEAK SHORTWAVE MOVING
THROUGH...AND SOME LINGERING MOISTURE...OPTED TO LINGER A FEW
ISOLATED SHOWERS NEAR LAKE MICHIGAN FOR THE FIRST PART OF THE
EVENING.
ATTENTION THEN TURNS TO THE SHORTWAVE THAT IS CURRENTLY IN THE
WESTERN PART OF THE NORTHWEST TERRITORIES. THIS SHORTWAVE WILL DIVE
SOUTHEAST TO LAKE WINNIPEG BY 12Z WEDNESDAY AND THEN THROUGH THE
UPPER GREAT LAKES WEDNESDAY NIGHT AND CONTINUE TO INFLUENCE THE
WEATHER INTO THURSDAY. A LOW PRESSURE SYSTEM ASSOCIATED WITH THIS
SHORTWAVE WILL TRACK ACROSS NORTHERN ONTARIO AND SWEEP THE MAIN COLD
FRONT ACROSS THE CWA LATE WEDNESDAY MORNING AND INTO THE AFTERNOON.
A WEAK TROUGH WILL TRY TO SLIDE ACROSS THE AREA LATE TUESDAY
NIGHT...WHICH COULD PRODUCE A FEW SHOWERS. BUT THE BEST CHANCE WILL
BE IN THE AFTERNOON WITH THE MAIN FRONT AND ASSISTANCE FROM DIURNAL
HEATING. THE MAIN INHIBITING FACTOR FOR MORE WIDESPREAD SHOWERS IS
THE SPLOTCHY NATURE OF THE DEEPER MOISTURE IN THE MODELS.
THUS...WILL GO FOR MORE LOW END CHANCES...WITH THE HIGHEST OVER THE
EAST BASED OFF THE TIMING OF THE FRONT WITH PEAK HEATING. DID CAP
THUNDER MENTION AT SLIGHT CHANCES...DUE TO THE WIDE VARIETY OF
MLCAPE VALUES IN THE MODELS (RANGING FROM 200-700 J/KG).
THURSDAY WILL BE COOL AND BREEZY ACROSS THE AREA WITH THE TIGHT
PRESSURE GRADIENT AS HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS.
850MB TEMPS WILL FALL FROM AROUND 11C ON WEDNESDAY TO 0-2C BY 00Z
THURSDAY. THE COOL TEMPERATURES OVER THE WARM LAKE WATERS WILL
COMBINE WITH THE LOW LEVEL MOISTURE SHOWN ON BOTH ECMWF/GFS FOR
LAKE INDUCED CLOUDS AND PROBABLY A FEW SHOWERS OVER THE LOCATIONS
FAVORED BY NORTH-NORTHWEST WINDS. EXPECT THE STRONGEST WIND GUSTS
TO BE OVER THE EASTERN CWA...WHERE WINDS WILL BE GUSTING TO
30MPH. WITH TEMPERATURES IN THE UPPER 50S AND LOWER 60S...THE
CLOUDS/WINDS/SHOWERS WILL LEAD TO A VERY OCTOBER LIKE DAY FOR MID
SEPTEMBER.
THE HIGH WILL BUILD SOUTHEAST ON THURSDAY NIGHT AND BE CENTERED
OVER THE AREA FOR FRIDAY AFTERNOON AND EVENING. THE DRY AIR
ASSOCIATED WITH THE HIGH WILL DIMINISH THE CLOUDS...BUT ALSO BRING
THE POTENTIAL FOR FROST OVER THE INTERIOR LOCATIONS THURSDAY NIGHT
AND FRIDAY NIGHT. CONFIDENCE IS FAIRLY LOW FOR THURSDAY NIGHT...AS
IT WILL DEPEND ON THE TIMING OF THE EXITING CLOUDS AND ALSO THE
WINDS WEAKENING UP FOR DECENT RADIATIONAL COOLING. THINK THE WESTERN
CWA WILL HAVE THE BEST CHANCE ON THURSDAY NIGHT AND WILL CONTINUE
THE COOLEST TEMPS THERE. THE CENTRAL AND EAST WILL HAVE THE BEST
SHOT FOR FROST ON FRIDAY NIGHT...SINCE THEY WILL BE THE CLOSEST TO
THE HIGH CENTER WITH THE LIGHTER WINDS. OVER THE FAR
WEST...SOUTHERLY RETURN FLOW ON THE BACK SIDE OF THE HIGH ON
FRIDAY NIGHT PRODUCES A LITTLE MORE UNCERTAINTY ON HOW COLD THE
TEMPS WILL GET BEFORE WINDS BEGIN TO PICK UP.
UPPER RIDGE WILL MOVE INTO THE AREA FOR SATURDAY AND BRING
TEMPERATURES BACK UP TOWARDS THE MID-UPPER 60S. THE NEXT SYSTEM
LOOKS TO AFFECT THE AREA ON SATURDAY NIGHT INTO SUNDAY. THIS
SHORTWAVE AND SURFACE LOW LOOK TO TAKE A SIMILAR TRACK TO THE ONE
THIS WEDNESDAY...ALTHOUGH THERE APPEARS TO BE A BETTER OPPORTUNITY
FOR RETURN FLOW TO PROVIDE MORE MOISTURE FOR SHOWERS AS THE FRONT
MOVES THROUGH. INSTABILITY AND MID-LEVEL LAPSE RATES ARE VERY
WEAK...SO HAVE LEFT THE MENTION OF THUNDER OUT OF THE FORECAST.
ONCE AGAIN...HIGH PRESSURE AND COOLER 850MB TEMPS WILL MOVE IN FOR
SUNDAY AFTERNOON INTO MONDAY...BRINGING ANOTHER BELOW NORMAL
TEMPERATURE DAY FOR MONDAY. GFS/ECMWF DO DIFFER ON THE AMOUNT OF
LOW LEVEL MOISTURE PRESENT FOR SUNDAY NIGHT INTO MONDAY...BUT WITH
THE COLD TEMPERATURES ALOFT IT SHOULDN/T TAKE MUCH TO KICK OF LAKE
CLOUDS OR EVEN SOME SHOWERS (AT LEAST FOR SUNDAY NIGHT).
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 125 AM EDT TUE SEP 10 2013
WITH ABUNDANT LOW LEVEL MOISTURE OVER THE AREA...VLIFR CONDITIONS
SHOULD PERSIST AT SAW/CMX OVERNIGHT INTO THE MORNING HRS. CONDITIONS
MAY BRIEFLY IMPROVE AT SAW AS SCT SHRA AND POSSIBLY A TSRA MOVE
THROUGH OVERNIGHT. MVFR CIGS AT IWD ARE ALSO EXPECTED TO GIVE WAY TO
IFR CIGS OVERNIGHT AS WINDS VEER LIGHT WRLY. ONLY GRADUAL
IMPROVEMENT IS EXPECTED BY MIDDAY WITH DAYTIME MIXING AND MODEST DRY
ADVECTION WITH INCREASING WRLY FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 318 AM EDT TUE SEP 10 2013
PATCHY TO AREAS OF FOG SHOULD SLOWLY DISSIPATE THIS MORNING. LOW
PRESSURE EXITING E LAKE SUPERIOR TODAY 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
ENCOMPASING 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 THURSDAY MORNING
THROUGH EARLY FRIDAY MORNING...WITH NW 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...JLB
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
127 AM EDT TUE SEP 10 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 419 PM EDT MON SEP 9 2013
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A MID LEVEL LOW OVER NE
MT. LOW IS WEAKENING/OPENING UP ON WATER VAPOR LOOP/ANALYSIS AND IS
FCST TO MOVE E THROUGH THE NRN PLAINS STATES TONIGHT. ASSOC SFC LOW
NOW OVER SW MN IS IN TURN FCST TO LIFT NE ACROSS THE FCST AREA
TONIGHT WITH APPROACH OF NRN PLAINS SHORTWAVE. STRONG WAA/ISENTROPIC
LIFT AHEAD OF FRONTAL BOUNDARY AS IT LIFTS FM SRN WI TOWARD SCNTRL
UPR MI THIS EVENING WILL PROVIDE FOCUS FOR ANOTHER ROUND OF
CONVECTION TONIGHT WITH THE POTENTIAL FOR STRONG TO POSSIBLY SVR
STORMS.
TONIGHT...BIGGEST THING GOING AGAINST SVR WX TONIGHT WILL BE LACK OF
SFC-BASED INSTABILITY FM TODAY DUE TO THICK CLOUDS PERSISTING OVER
THE AREA FM EARLIER MCS OVER THE NRN PLAINS. EVEN SO...COMBINATION
OF STRENGTHING LOW-LVL JET...INCREASING WAA/ISENTROPIC LIFT AND
ADVANCE OF WARM FRONTAL BOUNDARY TOWARD SCNTRL FCST AREA WILL ALLOW
FOR INCREASING ELEVATED INSTABILITY (NAM AND RUC SHOW ELEVATED CAPES
IN EXCESS OF 2000 J/KG THIS EVENING) AND DEEP LAYER SHEAR TO 45-50
KT WHICH COULD BRING POTENTIAL FOR STRONG TO POSSIBLY SVR
STORMS...WITH THE BEST THREAT FOR SVR OVER SCNTRL MI AND SE UPR MI
IN CLOSER PROXIMITY TO ADVANCING WARM FRONT. GIVEN LACK OF SFC-BASED
INSTABILITY...THERE MAY BE MORE OF A THREAT OF ELEVATED STORMS WITH
LARGE HAIL PERHAPS BEING THE BIGGER THREAT FOR OUR AREA. WILL
CONTINUE TO MENTION STRONG TO SEVERE STORMS IN THE HWO WITH THE BEST
THREAT OF HEAVY RAINFALL ACROSS NRN UPR MI AND THE KEWEENAW
PENINSULA. MODEL QPF STILL SUGGESTS THE KEWEENAW PENINSULA AND ERN
UPR MI WILL HAVE BEST CHC FOR HEAVY RAINFALL TONIGHT. LOOK FOR A
GENERAL DIMINISHING TREND IN CONVECTION OVERNIGHT (AFT 06Z) AS
LOW-LVL JET VEERS FM SW TO A MORE WRLY DIRECTION.
DENSE FOG HAS BEEN OBSERVED OVER THE KEWEENAW PENINSULA AND LAKE
SUPERIOR THIS AFTERNOON AND WOULD EXPECT FOG TO CONTINUE INTO THIS
EVENING WITH SHRA MOVING OVER THE AREA AND ONSHORE E-SE FLOW
PERSISTING. EXPECT PATCHY FOG TO MOVE ONSHORE TO NRN ZONES LATE
TONIGHT AS WIND SHIFTS N-NW BEHIND SFC TROUGH.
TUESDAY...THERE COULD BE SOME LINGERING UPSLOPE DZ IN THE MORNING
OVER NRN ZONES AS LOW-LVLS REMAIN MOIST. SOME ISOLD SHRA ARE ALSO
POSSIBLE MAINLY OVER SCNTRL AND ERN SECTIONS OF THE CWA UNTIL
LINGERING SFC BOUNDARY SAGS SE OF THE AREA LATE IN THE DAY.
PERSISTENT CLOUDS OVER THE AREA WILL RESULT IN HIGH TEMPS RANGING
FROM THE 60S NEAR LAKE SUPERIOR IN ONSHORE FLOW TO THE MID 70S
SCNTRL AND EAST ALONG FRONTAL BOUNDARY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 419 PM EDT MON SEP 9 2013
A WEAK HIGH PRESSURE RIDGE WILL SLIDE OVER THE AREA ON TUESDAY
NIGHT BEHIND THE EXITING LOW PRESSURE SYSTEM. WITH THE AREA STILL
UNDER THE RIGHT REAR OF THE UPPER JET...A WEAK SHORTWAVE MOVING
THROUGH...AND SOME LINGERING MOISTURE...OPTED TO LINGER A FEW
ISOLATED SHOWERS NEAR LAKE MICHIGAN FOR THE FIRST PART OF THE
EVENING.
ATTENTION THEN TURNS TO THE SHORTWAVE THAT IS CURRENTLY IN THE
WESTERN PART OF THE NORTHWEST TERRITORIES. THIS SHORTWAVE WILL DIVE
SOUTHEAST TO LAKE WINNIPEG BY 12Z WEDNESDAY AND THEN THROUGH THE
UPPER GREAT LAKES WEDNESDAY NIGHT AND CONTINUE TO INFLUENCE THE
WEATHER INTO THURSDAY. A LOW PRESSURE SYSTEM ASSOCIATED WITH THIS
SHORTWAVE WILL TRACK ACROSS NORTHERN ONTARIO AND SWEEP THE MAIN COLD
FRONT ACROSS THE CWA LATE WEDNESDAY MORNING AND INTO THE AFTERNOON.
A WEAK TROUGH WILL TRY TO SLIDE ACROSS THE AREA LATE TUESDAY
NIGHT...WHICH COULD PRODUCE A FEW SHOWERS. BUT THE BEST CHANCE WILL
BE IN THE AFTERNOON WITH THE MAIN FRONT AND ASSISTANCE FROM DIURNAL
HEATING. THE MAIN INHIBITING FACTOR FOR MORE WIDESPREAD SHOWERS IS
THE SPLOTCHY NATURE OF THE DEEPER MOISTURE IN THE MODELS.
THUS...WILL GO FOR MORE LOW END CHANCES...WITH THE HIGHEST OVER THE
EAST BASED OFF THE TIMING OF THE FRONT WITH PEAK HEATING. DID CAP
THUNDER MENTION AT SLIGHT CHANCES...DUE TO THE WIDE VARIETY OF
MLCAPE VALUES IN THE MODELS (RANGING FROM 200-700 J/KG).
THURSDAY WILL BE COOL AND BREEZY ACROSS THE AREA WITH THE TIGHT
PRESSURE GRADIENT AS HIGH PRESSURE BUILDS INTO THE NORTHERN PLAINS.
850MB TEMPS WILL FALL FROM AROUND 11C ON WEDNESDAY TO 0-2C BY 00Z
THURSDAY. THE COOL TEMPERATURES OVER THE WARM LAKE WATERS WILL
COMBINE WITH THE LOW LEVEL MOISTURE SHOWN ON BOTH ECMWF/GFS FOR
LAKE INDUCED CLOUDS AND PROBABLY A FEW SHOWERS OVER THE LOCATIONS
FAVORED BY NORTH-NORTHWEST WINDS. EXPECT THE STRONGEST WIND GUSTS
TO BE OVER THE EASTERN CWA...WHERE WINDS WILL BE GUSTING TO
30MPH. WITH TEMPERATURES IN THE UPPER 50S AND LOWER 60S...THE
CLOUDS/WINDS/SHOWERS WILL LEAD TO A VERY OCTOBER LIKE DAY FOR MID
SEPTEMBER.
THE HIGH WILL BUILD SOUTHEAST ON THURSDAY NIGHT AND BE CENTERED
OVER THE AREA FOR FRIDAY AFTERNOON AND EVENING. THE DRY AIR
ASSOCIATED WITH THE HIGH WILL DIMINISH THE CLOUDS...BUT ALSO BRING
THE POTENTIAL FOR FROST OVER THE INTERIOR LOCATIONS THURSDAY NIGHT
AND FRIDAY NIGHT. CONFIDENCE IS FAIRLY LOW FOR THURSDAY NIGHT...AS
IT WILL DEPEND ON THE TIMING OF THE EXITING CLOUDS AND ALSO THE
WINDS WEAKENING UP FOR DECENT RADIATIONAL COOLING. THINK THE WESTERN
CWA WILL HAVE THE BEST CHANCE ON THURSDAY NIGHT AND WILL CONTINUE
THE COOLEST TEMPS THERE. THE CENTRAL AND EAST WILL HAVE THE BEST
SHOT FOR FROST ON FRIDAY NIGHT...SINCE THEY WILL BE THE CLOSEST TO
THE HIGH CENTER WITH THE LIGHTER WINDS. OVER THE FAR
WEST...SOUTHERLY RETURN FLOW ON THE BACK SIDE OF THE HIGH ON
FRIDAY NIGHT PRODUCES A LITTLE MORE UNCERTAINTY ON HOW COLD THE
TEMPS WILL GET BEFORE WINDS BEGIN TO PICK UP.
UPPER RIDGE WILL MOVE INTO THE AREA FOR SATURDAY AND BRING
TEMPERATURES BACK UP TOWARDS THE MID-UPPER 60S. THE NEXT SYSTEM
LOOKS TO AFFECT THE AREA ON SATURDAY NIGHT INTO SUNDAY. THIS
SHORTWAVE AND SURFACE LOW LOOK TO TAKE A SIMILAR TRACK TO THE ONE
THIS WEDNESDAY...ALTHOUGH THERE APPEARS TO BE A BETTER OPPORTUNITY
FOR RETURN FLOW TO PROVIDE MORE MOISTURE FOR SHOWERS AS THE FRONT
MOVES THROUGH. INSTABILITY AND MID-LEVEL LAPSE RATES ARE VERY
WEAK...SO HAVE LEFT THE MENTION OF THUNDER OUT OF THE FORECAST.
ONCE AGAIN...HIGH PRESSURE AND COOLER 850MB TEMPS WILL MOVE IN FOR
SUNDAY AFTERNOON INTO MONDAY...BRINGING ANOTHER BELOW NORMAL
TEMPERATURE DAY FOR MONDAY. GFS/ECMWF DO DIFFER ON THE AMOUNT OF
LOW LEVEL MOISTURE PRESENT FOR SUNDAY NIGHT INTO MONDAY...BUT WITH
THE COLD TEMPERATURES ALOFT IT SHOULDN/T TAKE MUCH TO KICK OF LAKE
CLOUDS OR EVEN SOME SHOWERS (AT LEAST FOR SUNDAY NIGHT).
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 125 AM EDT TUE SEP 10 2013
WITH ABUNDANT LOW LEVEL MOISTURE OVER THE AREA...VLIFR CONDITIONS
SHOULD PERSIST AT SAW/CMX OVERNIGHT INTO THE MORNING HRS. CONDITIONS
MAY BRIEFLY IMPROVE AT SAW AS SCT SHRA AND POSSIBLY A TSRA MOVE
THROUGH OVERNIGHT. MVFR CIGS AT IWD ARE ALSO EXPECTED TO GIVE WAY TO
IFR CIGS OVERNIGHT AS WINDS VEER LIGHT WRLY. ONLY GRADUAL
IMPROVEMENT IS EXPECTED BY MIDDAY WITH DAYTIME MIXING AND MODEST DRY
ADVECTION WITH INCREASING WRLY FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EDT MON SEP 9 2013
LOW PRESSURE OVER NORTHEAST SD WILL LIFT INTO CENTRAL AND ERN UPR MI
TONIGHT AND THEN INTO FAR SE ONTARIO ON TUESDAY. NE WINDS FUNNELING
DOWN THE WRN PORTION OF LAKE SUPERIOR COULD GUST OVER 20 KT THIS
EVENING ON THE BACKSIDE OF THE LOW. A BRIEF RIDGE WILL MOVE OVER
LAKE SUPERIOR TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...OUT AHEAD OF
A WEAK TROUGH EXTENDING FROM NORTHERN ONTARIO DURING THE DAY
WEDNESDAY. LARGE HIGH PRESSURE OVER SOUTH CENTRAL CANADA WEDNESDAY
NIGHT WILL SLOWLY SINK ACROSS GREAT LAKES...WHERE IT WILL REMAIN
FROM THURSDAY NIGHT THROUGH FRIDAY NIGHT. NW WINDS WILL LIKELY GUST
20-30KTS LATE WEDNESDAY NIGHT THROUGH LATE THURSDAY NIGHT AS HIGH
PRESSURE SINKS IN FROM THE NNW. OTHERWISE WITH HIGH PRESSURE
OVERHEAD...LIGHT WINDS LESS THAN 20KTS ARE EXPECTED BY FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1221 PM CDT TUE SEP 10 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT TUE SEP 10 2013
A RATHER CONVOLUTED SURFACE/UPPER AIR PATTERN OVER THE REGION THIS
MORNING. CENTERS OF LOW PRESSURE WERE NOTED OVER NORTHERN WI...
NORTHERN MN AND ND. A LEAD COLD FRONT MEANDERED FROM NORTHERN WI
THROUGH SE MN AND EASTERN NE WHILE A SECONDARY COLD FRONT CURVED
ACROSS THE DAKOTAS. A THIRD AND REAL COLD FRONT WAS ACROSS SOUTH
CENTRAL CANADA... WHICH THE LONG TERM WILL DISCUSS BELOW. UPSTAIRS...
SUBTROPICAL MOISTURE WAS FLOWING NORTHEAST ACROSS THE CWA FROM THE
DESERT SOUTHWEST. A WAVE IN THE SUBTROPICAL FEED WAS NOTED OVER
WESTERN NE. THIS FEATURE IS PROGGED OVER SE MN BY THIS EVENING. A
LITTLE FURTHER NORTHWEST... A TROUGH IN THE POLAR JET WAS NEARING
THE ND/MN BORDER. THE DAY AHEAD WILL FEATURE INCREASING MID LEVEL
FRONTOGENESIS SPREADING NORTHEAST FROM SD/NE... THE INTERACTION
BETWEEN THE TWO WAVES ALOFT. SOME SHOWERS AND ISOLATED
THUNDERSTORMS HAVE ALREADY SPREAD INTO SOUTHWEST AND WEST CENTRAL
MN EARLY THIS MORNING. ALTHOUGH THE ACTIVITY IS MOVING NE A SLIGHT
NORTHWARD DRIFT IS SEEN IN THE OVERALL PATTERN. VARIOUS MODEL
SOLUTIONS SHOW PLENTY OF LAYER RH ALONG WITH THE MID LEVEL
FRONTOGENESIS. HOWEVER...LITTLE TO NO QPF IS PRODUCED WHICH DOES
NOT SEEM RIGHT WHEN LOOKING AT THE ADIABATIC OMEGA AND
SATURATION ON THE 305/310K THETA SURFACES. THE NAM PRODUCES THE
MOST QPF BUT APPEARS TO BE TOO FAR SOUTH INITIALLY. THE PAST FEW
RUNS OF THE HRRR MATCH WELL WITH THE TRENDS AND WOULD SUGGEST THAT
THE SHOWERS AND ISOLATED THUNDERSTORMS OVER WEST CENTRAL MN WILL
MOVE NORTHEAST THIS MORNING WITH A PERIOD OF DRYING IN THEIR WAKE.
THEN...MORE SHOWERS DEVELOP THIS AFTERNOON ACROSS SOUTHERN MN AND
ADJOINING AREAS OF WEST CENTRAL WI AS THE WAVE FROM NE ARRIVES AND
THE MID LEVEL FRONTOGENESIS BEGINS SLIPPING SOUTH. THE SHOWERS
SHOULD THEN END THIS EVENING OVER FAR EASTERN AND SOUTHERN AREAS
FOLLOWED BY DECREASING CLOUDINESS. HIGHS TODAY WILL BE TIED TO THE
CLOUDS AND SHOWERS. THE WARMEST AREAS WILL STRETCH FROM SOUTH
CENTRAL MN THROUGH KEAU WHERE MIDDLE 80S ARE LIKELY. TO THE NORTH
AND WEST... MIDDLE 70S TO LOWER 80S ARE FORECAST. IT WILL STILL BE
MILD TONIGHT WITH LOWS IN THE UPPER 50S TO MIDDLE 60S BUT THAT
WILL CERTAINLY BE CHANGING FOR WEDNESDAY AND THURSDAY MORNINGS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 345 AM CDT TUE SEP 10 2013
MODEL AGREEMENT ON THE EVOLUTION OF THE UPPER AIR PATTERN IS HIGH
THROUGH THE COURSE OF THE WORK WEEK...BUT BEGIN TO DIVERGE
SIGNIFICANTLY OVER THE WEEKEND. DURING THE WEEK...WE WILL SEE A
RE-AMPLIFICATION OF WHAT HAS BECOME THE ALL TOO FAMILIAR H5 PATTERN
SINCE MID JULY OF A WRN NOAM RIDGE AND ERN NOAM THROUGH...WITH NW
FLOW FOR US STUCK IN THE MIDDLE. WITHIN THE RIDGE...A MONSOONAL WAVE
CURRENTLY OVER THE FOUR CORNERS WILL SLOWLY DRIFT NE INTO THE NRN
PLAINS THIS WEEKEND. FROM THERE...TWO DIFFERENT STORIES APPEAR. THE
PROTAGONIST IN BOTH OF THESE STORIES IS A NRN STREAM WAVE THAT WILL
BE WORKING ACROSS THE TOP OF THE RIDGE OVER SRN CANADA THIS WEEKEND.
THE 10.00 ECMWF...10.00 GEM...AND 09.12 GFS DIG THIS NRN WAVE FAR
ENOUGH SOUTH TO PICK UP THE MONSOONAL DISTURBANCE...AND DRIVE A
FAIRLY POTENT POSITIVELY TILTED TROUGH THROUGH THE GREAT
LAKES/UPPER MS VALLEY SAT NIGHT. THE 10.00 GFS AND 09.12 ECMWF
KEEP THIS NRN STREAM WAVE FAR ENOUGH NORTH THAT THE MONSOONAL WAVE
IS LEFT TO WANDER OVER THE NRN PLAINS WITHIN THE RIDGE FOR THE
WEEKEND INTO NEXT WEEK. AS YOU CAN IMAGINE...WITH THE ECMWF/GFS
SWAPPING THEIR POSITIONS BETWEEN THE 09.12 AND 10.00
RUNS...CONFIDENCE IN THE FORECAST BEGINS TO DECREASE CONSIDERABLY
THIS WEEKEND.
AT THE SFC...WEDNESDAY WILL FEATURE THE PASSAGE OF A SECONDARY COLD
FRONT...THAT WILL GIVE WAY TO COOL/DRY HIGH PRESSURE FOR THU/FRI.
RETURN FLOW SETS UP FOR SATURDAY...WITH RAIN CHANCES RETURNING AS A
RESULT. THE CURRENT RUN OF THE ECMWF /OLD GFS/ DRIVE ANOTHER FRONT
THROUGH SAT NIGHT/SUNDAY...WHILE THE OLD ECMWF /NEW GFS/ KEEP A
MOIST SRLY FETCH GOING THROUGH THE WEEKEND AND INTO NEXT AS THE
MONSOONAL WAVE SITS AND SPINS OVER THE NRN PLAINS.
FOR TEMPERATURES...WEDNESDAY WILL BE THE WARMEST DAY...AS 925-850 MB
TEMPS CONTINUE TO RUN BETWEEN 16C AND 20C. A MAINLY SUNNY DAY IS
EXPECTED IN THE WAKE OF ALL OF TODAY/TONIGHTS WAVINESS...AND MIXING
THESE TEMPS DOWN SUPPORTS HIGHS IN THE LOW/MID 80S. THE SECONDARY
COLD FRONT CLEARING THE AREA WEDNESDAY NIGHT WILL SEND 925-850 MB
TEMPS BACK INTO THE SINGLE DIGITS...WHICH WILL BRING BACK
TEMPERATURES SLIGHTLY BELOW NORMAL TO END THE WEEK. IN ADDITION...
ON FRIDAY MORNING...HIGH PRESSURE WILL BE OVER/AROUND WRN LAKE
SUPERIOR AND THE COMBO OF CLEAR SKIES AND CALM WILL GIVE US OUR
FIRST SHOT AT SEEING SOME FROST /WITH LOWS INTO THE MID 30S/ ACROSS
RUSK/BARRON/DUNN/CHIPPEWA COUNTIES IN WI. BY THE WEEKEND...
TEMPS/THICKNESSES WILL INCREASE...BUT THE RETURN OF CLOUD COVER WILL
HELP HOLD HIGHS BACK AROUND NORMAL...WHICH ARE ALREADY DOWN INTO THE
LOW/MID 70S.
AS FOR PRECIP...MODELS HAVE BEEN TRENDING SLOWER WITH ITS RETURN
OVER THE WEEKEND...SO SLOWED THE EASTWARD ADVANCEMENT OF POPS ACROSS
THE AREA ON SATURDAY AS A RESULT. THE HIGHER POPS IN THE FORECAST
SAT NIGHT INTO SUNDAY WOULD FAVOR THE 10.00 ECMWF SOLUTION...BUT THE
IMPACT OF THE 10.00 GFS /ALONG WITH THE 09.12 ECMWF/ WAS TO HAVE
SLIGHTS CONTINUE INTO MONDAY. DOES NOT LOOK PRECIP AMOUNTS WOULD BE
OVERWHELMING WITH THIS SYSTEM...BUT CONSIDERING MSP HAS ONLY
MEASURED 9 HUNDREDTHS OF AN INCH OF RAIN SINCE 1.33 INCHES FELL ON
AUGUST 6TH...WE WILL TAKE ANYTHING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1204 PM CDT TUE SEP 10 2013
A BAND OF -SHRA CONTINUED TO MOVE ACROSS EC/SC MN AND INTO WC WI
EARLY THIS AFTN. CIGS AND VSBYS REMAIN VFR AND WILL REMAIN VFR
THRU 00Z/11. HOWEVER...MVFR/IFR CIGS ARE NOTED ALONG THE FAR
NORTHERN PART OF MPX FA...WHICH COULD AFFECT KAXN IN THE NEXT HR
OR TWO. WILL CONTINUE WITH VFR CIGS AT KAXN...WITH MAYBE A
TEMPORARY PERIOD FOR AN HR OR TWO OF MVFR CIGS. OTHERWISE...NOT
MUCH AVIATION CONCERNS THRU THE AFTN WITH THE BULK OF THE TSRA
ACTIVITY SOUTH OF MPX FA. WINDS WILL REMAIN FROM THE SW TO W/WNW
DURING THE AFTN...WITH A MORE W/WNW DIRECTION OVERNIGHT...AND
BECOMING STRONGER AND GUSTY BY WEDNESDAY AFTN. SOME FG/BR IS
POSSIBLE AT KSTC/KRNH/KEAU...BUT CLOUD COVER MAY HINDER WIDESPREAD
DEVELOPMENT. SOMETHING TO WATCH BASED ON CURRENT MODEL TRENDS
DECREASING CLOUD COVER BY MORNING.
KMSP...
VCSH WILL CONTINUE THRU 21Z...WITH THE BULK OF THE RESTRICTIONS TO
VSBYS OCCURRING EAST OF THE TERMINAL BEGINNING AT 18Z. CIGS WILL
REMAIN AOA 11K THRU THE AFTN...WITH WINDS GENERALLY FROM THE
WSW/SW EARLY...MORE W/WSW AFTN 21Z. WINDS WILL SHIFT MORE WNW/NW
BY WEDNESDAY AFTN ALONG WITH A FEW GUSTS.
/OUTLOOK FOR KMSP/
THU...VFR. NNW WINDS 10-15 KTS.
FRI...VFR. E/SE WINDS 5 KTS.
SAT...VFR SW WINDS 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...RAH
LONG TERM...MPG
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
633 AM CDT TUE SEP 10 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT TUE SEP 10 2013
A RATHER CONVOLUTED SURFACE/UPPER AIR PATTERN OVER THE REGION THIS
MORNING. CENTERS OF LOW PRESSURE WERE NOTED OVER NORTHERN WI...
NORTHERN MN AND ND. A LEAD COLD FRONT MEANDERED FROM NORTHERN WI
THROUGH SE MN AND EASTERN NE WHILE A SECONDARY COLD FRONT CURVED
ACROSS THE DAKOTAS. A THIRD AND REAL COLD FRONT WAS ACROSS SOUTH
CENTRAL CANADA... WHICH THE LONG TERM WILL DISCUSS BELOW. UPSTAIRS...
SUBTROPICAL MOISTURE WAS FLOWING NORTHEAST ACROSS THE CWA FROM THE
DESERT SOUTHWEST. A WAVE IN THE SUBTROPICAL FEED WAS NOTED OVER
WESTERN NE. THIS FEATURE IS PROGGED OVER SE MN BY THIS EVENING. A
LITTLE FURTHER NORTHWEST... A TROUGH IN THE POLAR JET WAS NEARING
THE ND/MN BORDER. THE DAY AHEAD WILL FEATURE INCREASING MID LEVEL
FRONTOGENESIS SPREADING NORTHEAST FROM SD/NE... THE INTERACTION
BETWEEN THE TWO WAVES ALOFT. SOME SHOWERS AND ISOLATED
THUNDERSTORMS HAVE ALREADY SPREAD INTO SOUTHWEST AND WEST CENTRAL
MN EARLY THIS MORNING. ALTHOUGH THE ACTIVITY IS MOVING NE A SLIGHT
NORTHWARD DRIFT IS SEEN IN THE OVERALL PATTERN. VARIOUS MODEL
SOLUTIONS SHOW PLENTY OF LAYER RH ALONG WITH THE MID LEVEL
FRONTOGENESIS. HOWEVER...LITTLE TO NO QPF IS PRODUCED WHICH DOES
NOT SEEM RIGHT WHEN LOOKING AT THE ADIABATIC OMEGA AND
SATURATION ON THE 305/310K THETA SURFACES. THE NAM PRODUCES THE
MOST QPF BUT APPEARS TO BE TOO FAR SOUTH INITIALLY. THE PAST FEW
RUNS OF THE HRRR MATCH WELL WITH THE TRENDS AND WOULD SUGGEST THAT
THE SHOWERS AND ISOLATED THUNDERSTORMS OVER WEST CENTRAL MN WILL
MOVE NORTHEAST THIS MORNING WITH A PERIOD OF DRYING IN THEIR WAKE.
THEN...MORE SHOWERS DEVELOP THIS AFTERNOON ACROSS SOUTHERN MN AND
ADJOINING AREAS OF WEST CENTRAL WI AS THE WAVE FROM NE ARRIVES AND
THE MID LEVEL FRONTOGENESIS BEGINS SLIPPING SOUTH. THE SHOWERS
SHOULD THEN END THIS EVENING OVER FAR EASTERN AND SOUTHERN AREAS
FOLLOWED BY DECREASING CLOUDINESS. HIGHS TODAY WILL BE TIED TO THE
CLOUDS AND SHOWERS. THE WARMEST AREAS WILL STRETCH FROM SOUTH
CENTRAL MN THROUGH KEAU WHERE MIDDLE 80S ARE LIKELY. TO THE NORTH
AND WEST... MIDDLE 70S TO LOWER 80S ARE FORECAST. IT WILL STILL BE
MILD TONIGHT WITH LOWS IN THE UPPER 50S TO MIDDLE 60S BUT THAT
WILL CERTAINLY BE CHANGING FOR WEDNESDAY AND THURSDAY MORNINGS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 345 AM CDT TUE SEP 10 2013
MODEL AGREEMENT ON THE EVOLUTION OF THE UPPER AIR PATTERN IS HIGH
THROUGH THE COURSE OF THE WORK WEEK...BUT BEGIN TO DIVERGE
SIGNIFICANTLY OVER THE WEEKEND. DURING THE WEEK...WE WILL SEE A
RE-AMPLIFICATION OF WHAT HAS BECOME THE ALL TOO FAMILIAR H5 PATTERN
SINCE MID JULY OF A WRN NOAM RIDGE AND ERN NOAM THROUGH...WITH NW
FLOW FOR US STUCK IN THE MIDDLE. WITHIN THE RIDGE...A MONSOONAL WAVE
CURRENTLY OVER THE FOUR CORNERS WILL SLOWLY DRIFT NE INTO THE NRN
PLAINS THIS WEEKEND. FROM THERE...TWO DIFFERENT STORIES APPEAR. THE
PROTAGONIST IN BOTH OF THESE STORIES IS A NRN STREAM WAVE THAT WILL
BE WORKING ACROSS THE TOP OF THE RIDGE OVER SRN CANADA THIS WEEKEND.
THE 10.00 ECMWF...10.00 GEM...AND 09.12 GFS DIG THIS NRN WAVE FAR
ENOUGH SOUTH TO PICK UP THE MONSOONAL DISTURBANCE...AND DRIVE A
FAIRLY POTENT POSITIVELY TITLED THROUGH THE GREAT LAKES/UPPER MS
VALLEY SAT NIGHT. THE 10.00 GFS AND 09.12 ECMWF KEEP THIS NRN STREAM
WAVE FAR ENOUGH NORTH THAT THE MONSOONAL WAVE IS LEFT TO WANDER OVER
THE NRN PLAINS WITHIN THE RIDGE FOR THE WEEKEND INTO NEXT WEEK. AS
YOU CAN IMAGINE...WITH THE ECMWF/GFS SWAPPING THEIR POSITIONS
BETWEEN THE 09.12 AND 10.00 RUNS...CONFIDENCE IN THE FORECAST BEGINS
TO DECREASE CONSIDERABLY THIS WEEKEND.
AT THE SFC...WEDNESDAY WILL FEATURE THE PASSAGE OF A SECONDARY COLD
FRONT...THAT WILL GIVE WAY TO COOL/DRY HIGH PRESSURE FOR THU/FRI.
RETURN FLOW SETS UP FOR SATURDAY...WITH RAIN CHANCES RETURNING AS A
RESULT. THE CURRENT RUN OF THE ECMWF /OLD GFS/ DRIVE ANOTHER FRONT
THROUGH SAT NIGHT/SUNDAY...WHILE THE OLD ECMWF /NEW GFS/ KEEP A
MOIST SRLY FETCH GOING THROUGH THE WEEKEND AND INTO NEXT AS THE
MONSOONAL WAVE SITS AND SPINS OVER THE NRN PLAINS.
FOR TEMPERATURES...WEDNESDAY WILL BE THE WARMEST DAY...AS 925-850 MB
TEMPS CONTINUE TO RUN BETWEEN 16C AND 20C. A MAINLY SUNNY DAY IS
EXPECTED IN THE WAKE OF ALL OF TODAY/TONIGHTS WAVINESS...AND MIXING
THESE TEMPS DOWN SUPPORTS HIGHS IN THE LOW/MID 80S. THE SECONDARY
COLD FRONT CLEARING THE AREA WEDNESDAY NIGHT WILL SEND 925-850 MB
TEMPS BACK INTO THE SINGLE DIGITS...WHICH WILL BRING BACK
TEMPERATURES SLIGHTLY BELOW NORMAL TO END THE WEEK. IN ADDITION...
ON FRIDAY MORNING...HIGH PRESSURE WILL BE OVER/AROUND WRN LAKE
SUPERIOR AND THE COMBO OF CLEAR SKIES AND CALM WILL GIVE US OUR
FIRST SHOT AT SEEING SOME FROST /WITH LOWS INTO THE MID 30S/ ACROSS
RUSK/BARRON/DUNN/CHIPPEWA COUNTIES IN WI. BY THE WEEKEND...
TEMPS/THICKNESSES WILL INCREASE...BUT THE RETURN OF CLOUD COVER WILL
HELP HOLD HIGHS BACK AROUND NORMAL...WHICH ARE ALREADY DOWN INTO THE
LOW/MID 70S.
AS FOR PRECIP...MODELS HAVE BEEN TRENDING SLOWER WITH ITS RETURN
OVER THE WEEKEND...SO SLOWED THE EASTWARD ADVANCEMENT OF POPS ACROSS
THE AREA ON SATURDAY AS A RESULT. THE HIGHER POPS IN THE FORECAST
SAT NIGHT INTO SUNDAY WOULD FAVOR THE 10.00 ECMWF SOLUTION...BUT THE
IMPACT OF THE 10.00 GFS /ALONG WITH THE 09.12 ECMWF/ WAS TO HAVE
SLIGHTS CONTINUE INTO MONDAY. DOES NOT LOOK PRECIP AMOUNTS WOULD BE
OVERWHELMING WITH THIS SYSTEM...BUT CONSIDERING MSP HAS ONLY
MEASURED 9 HUNDREDTHS OF AN INCH OF RAIN SINCE 1.33 INCHES FELL ON
AUGUST 6TH...WE WILL TAKE ANYTHING.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 630 AM CDT TUE SEP 10 2013
STILL DEALING WITH SOME FINGERS OF MVFR CIGS JUST TO THE NORTH AND
EAST OF KSTC AND KMSP EARLY THIS MORNING. THE TREND THE PAST FEW HOURS
HAS BEEN FOR SOME CONTRACTION OFF TO THE NORTHEAST. PART OF THIS
MAY BE DUE TO THE LOW LEVEL FLOW BACKING IN ADVANCE OF THE NEXT
COOL FRONT ACROSS NW MN. KRNH AND KEAU AT MOST RISK FOR BKN015
FOR A FEW HOURS THIS MORNING. SHOWERS HAVE BEEN ON THE INCREASE AS
WELL FROM WEST CENTRAL MN THROUGH KDLH OVERNIGHT AS A MID LEVEL WAVE
APPROACHES FROM THE CENTRAL PLAINS. SHORT TERM SOLUTIONS SUGGEST
THAT KSTC IS IN THE PATH OF -SHRA FOR A FEW HOURS THIS MORNING
WITH THE SOUTHERN EDGE OF THE ACTIVITY LIKELY SKIRTING KMSP AND
KRNH. A LULL IN THE SHOWERS THEN EXPECTED DURING THE LATE MORNING
AND EARLY AFTERNOON HOURS WITH MORE SHOWERS DEVELOPING NEAR A
KRWF - SOUTH TWIN CITIES METRO - KEAU LINE DURING THE AFTERNOON
AND THEN PUSHING OFF TO THE SOUTHEAST THIS EVENING. ISOLATED
THUNDER CAN/T BE RULED OUT. CEILINGS OUTSIDE OF EARLY THIS MORNING
WILL BE MORE SCT-BKN040-60 BKN-OVC080-100. WESTERLY WINDS UP TO 10
KNOT TODAY THEN DIMINISHING TO 6 KNOTS OR LESS TONIGHT. RISK FOR
MVFR FOG TONIGHT AT KSTC...KRNH AND KEAU WITH 3-5 SM INSERTED AT
THIS POINT AT 09Z.
KMSP...
EXPECT MVFR CIGS TO STAY JUST NORTHEAST OF THE AIRFIELD THIS
MORNING. SOME LIGHT RAIN/SPRINKLES WILL SKIRT THE AREA BETWEEN 13Z
AND 16Z. THERE IS ANOTHER THREAT FOR SHOWERS AND ISOLATED
THUNDERSTORMS IN THE 21Z-24Z TIME FRAME. WESTERLY WINDS TODAY
(260-290) AROUND 6 KNOTS THIS MORNING AND 10 KNOTS THIS AFTERNOON.
/OUTLOOK FOR KMSP/
WED...VFR. NW WINDS 10-15 KTS.
THU...VFR. N WINDS 10-15 KTS.
FRI...VFR. E WINDS 5 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...RAH
LONG TERM...MPG
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
358 AM CDT TUE SEP 10 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CDT TUE SEP 10 2013
A RATHER CONVOLUTED SURFACE/UPPER AIR PATTERN OVER THE REGION THIS
MORNING. CENTERS OF LOW PRESSURE WERE NOTED OVER NORTHERN WI...
NORTHERN MN AND ND. A LEAD COLD FRONT MEANDERED FROM NORTHERN WI
THROUGH SE MN AND EASTERN NE WHILE A SECONDARY COLD FRONT CURVED
ACROSS THE DAKOTAS. A THIRD AND REAL COLD FRONT WAS ACROSS SOUTH
CENTRAL CANADA... WHICH THE LONG TERM WILL DISCUSS BELOW. UPSTAIRS...
SUBTROPICAL MOISTURE WAS FLOWING NORTHEAST ACROSS THE CWA FROM THE
DESERT SOUTHWEST. A WAVE IN THE SUBTROPICAL FEED WAS NOTED OVER
WESTERN NE. THIS FEATURE IS PROGGED OVER SE MN BY THIS EVENING. A
LITTLE FURTHER NORTHWEST... A TROUGH IN THE POLAR JET WAS NEARING
THE ND/MN BORDER. THE DAY AHEAD WILL FEATURE INCREASING MID LEVEL
FRONTOGENESIS SPREADING NORTHEAST FROM SD/NE... THE INTERACTION
BETWEEN THE TWO WAVES ALOFT. SOME SHOWERS AND ISOLATED
THUNDERSTORMS HAVE ALREADY SPREAD INTO SOUTHWEST AND WEST CENTRAL
MN EARLY THIS MORNING. ALTHOUGH THE ACTIVITY IS MOVING NE A SLIGHT
NORTHWARD DRIFT IS SEEN IN THE OVERALL PATTERN. VARIOUS MODEL
SOLUTIONS SHOW PLENTY OF LAYER RH ALONG WITH THE MID LEVEL
FRONTOGENESIS. HOWEVER...LITTLE TO NO QPF IS PRODUCED WHICH DOES
NOT SEEM RIGHT WHEN LOOKING AT THE ADIABATIC OMEGA AND
SATURATION ON THE 305/310K THETA SURFACES. THE NAM PRODUCES THE
MOST QPF BUT APPEARS TO BE TOO FAR SOUTH INITIALLY. THE PAST FEW
RUNS OF THE HRRR MATCH WELL WITH THE TRENDS AND WOULD SUGGEST THAT
THE SHOWERS AND ISOLATED THUNDERSTORMS OVER WEST CENTRAL MN WILL
MOVE NORTHEAST THIS MORNING WITH A PERIOD OF DRYING IN THEIR WAKE.
THEN...MORE SHOWERS DEVELOP THIS AFTERNOON ACROSS SOUTHERN MN AND
ADJOINING AREAS OF WEST CENTRAL WI AS THE WAVE FROM NE ARRIVES AND
THE MID LEVEL FRONTOGENESIS BEGINS SLIPPING SOUTH. THE SHOWERS
SHOULD THEN END THIS EVENING OVER FAR EASTERN AND SOUTHERN AREAS
FOLLOWED BY DECREASING CLOUDINESS. HIGHS TODAY WILL BE TIED TO THE
CLOUDS AND SHOWERS. THE WARMEST AREAS WILL STRETCH FROM SOUTH
CENTRAL MN THROUGH KEAU WHERE MIDDLE 80S ARE LIKELY. TO THE NORTH
AND WEST... MIDDLE 70S TO LOWER 80S ARE FORECAST. IT WILL STILL BE
MILD TONIGHT WITH LOWS IN THE UPPER 50S TO MIDDLE 60S BUT THAT
WILL CERTAINLY BE CHANGING FOR WEDNESDAY AND THURSDAY MORNINGS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 345 AM CDT TUE SEP 10 2013
MODEL AGREEMENT ON THE EVOLUTION OF THE UPPER AIR PATTERN IS HIGH
THROUGH THE COURSE OF THE WORK WEEK...BUT BEGIN TO DIVERGE
SIGNIFICANTLY OVER THE WEEKEND. DURING THE WEEK...WE WILL SEE A
RE-AMPLIFICATION OF WHAT HAS BECOME THE ALL TOO FAMILIAR H5 PATTERN
SINCE MID JULY OF A WRN NOAM RIDGE AND ERN NOAM THROUGH...WITH NW
FLOW FOR US STUCK IN THE MIDDLE. WITHIN THE RIDGE...A MONSOONAL WAVE
CURRENTLY OVER THE FOUR CORNERS WILL SLOWLY DRIFT NE INTO THE NRN
PLAINS THIS WEEKEND. FROM THERE...TWO DIFFERENT STORIES APPEAR. THE
PROTAGONIST IN BOTH OF THESE STORIES IS A NRN STREAM WAVE THAT WILL
BE WORKING ACROSS THE TOP OF THE RIDGE OVER SRN CANADA THIS WEEKEND.
THE 10.00 ECMWF...10.00 GEM...AND 09.12 GFS DIG THIS NRN WAVE FAR
ENOUGH SOUTH TO PICK UP THE MONSOONAL DISTURBANCE...AND DRIVE A
FAIRLY POTENT POSITIVELY TITLED THROUGH THE GREAT LAKES/UPPER MS
VALLEY SAT NIGHT. THE 10.00 GFS AND 09.12 ECMWF KEEP THIS NRN STREAM
WAVE FAR ENOUGH NORTH THAT THE MONSOONAL WAVE IS LEFT TO WANDER OVER
THE NRN PLAINS WITHIN THE RIDGE FOR THE WEEKEND INTO NEXT WEEK. AS
YOU CAN IMAGINE...WITH THE ECMWF/GFS SWAPPING THEIR POSITIONS
BETWEEN THE 09.12 AND 10.00 RUNS...CONFIDENCE IN THE FORECAST BEGINS
TO DECREASE CONSIDERABLY THIS WEEKEND.
AT THE SFC...WEDNESDAY WILL FEATURE THE PASSAGE OF A SECONDARY COLD
FRONT...THAT WILL GIVE WAY TO COOL/DRY HIGH PRESSURE FOR THU/FRI.
RETURN FLOW SETS UP FOR SATURDAY...WITH RAIN CHANCES RETURNING AS A
RESULT. THE CURRENT RUN OF THE ECMWF /OLD GFS/ DRIVE ANOTHER FRONT
THROUGH SAT NIGHT/SUNDAY...WHILE THE OLD ECMWF /NEW GFS/ KEEP A
MOIST SRLY FETCH GOING THROUGH THE WEEKEND AND INTO NEXT AS THE
MONSOONAL WAVE SITS AND SPINS OVER THE NRN PLAINS.
FOR TEMPERATURES...WEDNESDAY WILL BE THE WARMEST DAY...AS 925-850 MB
TEMPS CONTINUE TO RUN BETWEEN 16C AND 20C. A MAINLY SUNNY DAY IS
EXPECTED IN THE WAKE OF ALL OF TODAY/TONIGHTS WAVINESS...AND MIXING
THESE TEMPS DOWN SUPPORTS HIGHS IN THE LOW/MID 80S. THE SECONDARY
COLD FRONT CLEARING THE AREA WEDNESDAY NIGHT WILL SEND 925-850 MB
TEMPS BACK INTO THE SINGLE DIGITS...WHICH WILL BRING BACK
TEMPERATURES SLIGHTLY BELOW NORMAL TO END THE WEEK. IN ADDITION...
ON FRIDAY MORNING...HIGH PRESSURE WILL BE OVER/AROUND WRN LAKE
SUPERIOR AND THE COMBO OF CLEAR SKIES AND CALM WILL GIVE US OUR
FIRST SHOT AT SEEING SOME FROST /WITH LOWS INTO THE MID 30S/ ACROSS
RUSK/BARRON/DUNN/CHIPPEWA COUNTIES IN WI. BY THE WEEKEND...
TEMPS/THICKNESSES WILL INCREASE...BUT THE RETURN OF CLOUD COVER WILL
HELP HOLD HIGHS BACK AROUND NORMAL...WHICH ARE ALREADY DOWN INTO THE
LOW/MID 70S.
AS FOR PRECIP...MODELS HAVE BEEN TRENDING SLOWER WITH ITS RETURN
OVER THE WEEKEND...SO SLOWED THE EASTWARD ADVANCEMENT OF POPS ACROSS
THE AREA ON SATURDAY AS A RESULT. THE HIGHER POPS IN THE FORECAST
SAT NIGHT INTO SUNDAY WOULD FAVOR THE 10.00 ECMWF SOLUTION...BUT THE
IMPACT OF THE 10.00 GFS /ALONG WITH THE 09.12 ECMWF/ WAS TO HAVE
SLIGHTS CONTINUE INTO MONDAY. DOES NOT LOOK PRECIP AMOUNTS WOULD BE
OVERWHELMING WITH THIS SYSTEM...BUT CONSIDERING MSP HAS ONLY
MEASURED 9 HUNDREDTHS OF AN INCH OF RAIN SINCE 1.33 INCHES FELL ON
AUGUST 6TH...WE WILL TAKE ANYTHING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1110 PM CDT MON SEP 9 2013
LATEST GUIDANCE IS BACKPEDALING AWAY FROM THE IDEA OF FOG...BUT
LOW LEVEL STRATUS WILL BE THE MAIN CONCERN. THE LOWEST CEILINGS
WILL BE FURTHER NORTH...BUT AXN AND STC IN PARTICULAR WILL BE THE
MOST VULNERABLE TO CEILINGS UNDER 2K FT. FOG POTENTIAL MAY BE
LIMITED DUE TO THE DECLINING DEW POINTS AND WESTERLY SURFACE
WINDS. BEYOND THE OVERNIGHT HOURS...VFR CONDITIONS WILL PREVAIL AS
JUST MID AND HIGH CLOUDS WILL BE LEFT OVER. OVERALL...RAISED VSBYS
AND CEILINGS...BUT DUE TO MODEL DISAGREEMENT FROM THE HRRR TO THE
RAP...THIS IS A LOWER CONFIDENCE FORECAST THAT HAS TAKEN THE HRRR
SIDE. IF THE RAP PANS OUT BETTER...WIDESPREAD LOW CEILINGS WILL
AFFECT MSP AND WESTERN WISCONSIN. THERE IS A CHANCE OF SHOWERS
TOMORROW AFTERNOON...BUT DID NOT INTRODUCE AT ANY TAF SITES AT
THIS TIME.
KMSP...CURRENTLY FORECASTING VFR CONDITIONS THROUGH THE TAF
PERIOD...BUT AGAIN THE RAP IS CONCERNING IN THAT IT WANTS TO BRING
IFR CIGS DOWN FROM THE NORTHWEST. CURRENT THINKING IS THAT IT IS
OVER ZEALOUS ON BOUNDARY LAYER MOISTURE SO HAVE TAKEN A MORE
OPTIMISTIC APPROACH. BEYOND MORNING...VFR CONDITIONS WILL PREVAIL.
/OUTLOOK FOR KMSP/
WED...VFR. WINDS NW AT 10KTS
TRU...VFR. WINDS N AT 10KTS.
FRI...VFR. WINDS SE AT 05KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...RAH
LONG TERM...MPG
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1120 PM CDT MON SEP 9 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 315 PM CDT MON SEP 9 2013
PERHAPS THIS WILL BE THE LAST 90 DEGREE DAY OF THE YEAR FOR THE CWA.
A 24HR LOOP OF WATER VAPOR TOGETHER WITH 500MB HEIGHTS SHOWED THE
UPPER LEVEL RIDGE ACROSS THE SOUTHEASTERN US...WITH A DEAMPLIFYING
SHORTWAVE OVER THE MT/ND BORDER. A SURFACE LOW WAS LOCATED AHEAD OF
THIS SHORTWAVE IN THE EASTERN DAKOTAS...WITH A WELL DEFINED WARM
FRONT EXTENDING EASTWARD THROUGH CENTRAL MN INTO NORTHERN WI. A
TRAILING COLD FRONT EXTENDED SOUTHWEST THROUGH WESTERN NEBRASKA.
THIS SETUP PLACED THE WARM SECTOR DIRECTLY OVER THE CORN BELT
REGION.
DESPITE THE MORNING STRATUS...EARLY AFTERNOON TEMPERATURES
WERE IN THE LOW 90S ACROSS SOUTHERN MN AND WESTERN WI...AS A WARM
NOSE OF H850 TEMPERATURES OF 25C WAS LOCATED OVER SOUTHEASTERN MN.
MECHANICAL MIXING...TOGETHER WITH DIABATIC HEATING SHOULD ALLOW
SURFACE TEMPS TO RAISE A FEW MORE DEGREES YET THIS AFTERNOON. THIS
WILL LEAD TO A CONDITIONALLY UNSTABLE AIRMASS IN THE AFOREMENTIONED
WARM SECTOR. HOWEVER...H700 OF 12-13C SHOULD KEEP THE AIRMASS CAPPED
ACROSS SOUTHERN MN. CLOSER TO THE WARM FRONT INCREASED ISENTROPIC
ASCENT AND UPPER LEVEL FORCING WITH THE APPROACHING 500MB WAVE WILL
SUPPORT THUNDERSTORMS LATER THIS EVENING AND OVERNIGHT. THE 15Z RUN
OF THE HOPWRF DEVELOPS A FEW CONVECTIVE CELLS NORTH OF THE METRO
INTO WESTERN WI. DEEP LAYER SHEAR OF AROUND 40KTS...TOGETHER WITH
VEERING WINDS IN THE LOWER LEVELS ALONG THE WARM FRONT WILL SUPPORT
SUPERCELLS ALONG WITH THE THREAT OF A TORNADO EARLY ON WHERE THE
LOWER LCLS AND HIGH HELICITY VALUES OF THE WARM FRONT MEET THE
EAST/WEST CAPE GRADIENT. MOST OF THE HIRES MODELS...SUCH AS THE SPC
WRFNMM AND HRRR...ALSO WANT TO DEVELOP THUNDERSTORMS ALONG THE COLD
FRONT. THERE IS NOT MUCH LOW LEVEL CONVERGENCE ALONG THE COLD
FRONT...ESPECIALLY CONSIDERING THE STRONG CAP IN PLACE...SO
THEREFORE THINK THE WARM FRONT HAS THE HIGHEST POTENTIAL FOR SEVERE
WEATHER.
LATER TONIGHT THE LOW LEVEL MOISTURE WILL SUPPORT LOW STRATUS AND
PATCHY FOG...ESPECIALLY ACROSS THE NORTHERN PORTION OF THE CWA.
THEREFORE ADDED PATCH FOG TO THE GRIDS. ON TUESDAY THE SURFACE
BOUNDARY WILL BE ACROSS THE FAR EASTER PART OF THE CWA...AND THIS
WILL ONCE AGAIN BE THE FOCUS FOR A FEW AFTERNOON SHOWERS AND
THUNDERSTORMS. THEREFORE HAVE THE PRECIP CHANCES TAPERING OFF BY
EARLY TUESDAY MORNING...AND RETURNING LATE TUESDAY AFTERNOON.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 315 PM CDT MON SEP 9 2013
COOLER /BUT NOT COOL/ TEMPERATURES WILL ARRIVE IN THE WAKE OF THE
COLD FRONT FOR TUESDAY AND WEDNESDAY...ALTHOUGH THE NOTABLY COOLER
AIR WILL NOT BE FELT UNTIL THURSDAY AS BROAD SURFACE HIGH PRESSURE
SETTLES IN BEHIND A SECONDARY COLD FRONT. HIGHS GENERALLY FROM 78
TO 85 WILL PREVAIL FOR TUESDAY AND WEDNESDAY...WITH HIGHS FROM 65
TO 75 ON THURSDAY AND FRIDAY. AS FAR AS PRECIPITATION GOES FOR THE
REMAINDER OF THE WORK WEEK...COULD SEE A FEW SHOWERS IN
THE FAR SOUTHEAST ON TUESDAY EVENING /MAINLY INTERSTATE 90
CORRIDOR/ AS WEAK MID LEVEL SHORTWAVE ENERGY PASSES OVER WITH THE
DEPARTING FRONT NEARBY. OTHERWISE...DRY CONDITIONS ARE EXPECTED
THROUGH FRIDAY.
MODELS ARE STILL FORECASTING A TRANSITION TO RETURN FLOW ON FRIDAY
NIGHT...WITH A NOTABLE LOW LEVEL JET PROGGED TO INSTIGATE THE
DEVELOPMENT SHOWERS AND THUNDERSTORMS ON SATURDAY AND SUNDAY.
UNFORTUNATELY...THERE ARE STILL A FAIR AMOUNT OF DIFFERENCES
BETWEEN THE ECMWF AND GFS REGARDING TIMING. HAVE RETAINED HIGH
CHANCE POPS AT THIS POINT. BY NEXT MONDAY...WIDESPREAD HIGHS IN
THE 60S APPEAR REASONABLE...WITH LOWS IN THE 40S /POSSIBLY EVEN
UPPER 30S OVER WEST CENTRAL WI/.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1110 PM CDT MON SEP 9 2013
LATEST GUIDANCE IS BACKPEDALING AWAY FROM THE IDEA OF FOG...BUT
LOW LEVEL STRATUS WILL BE THE MAIN CONCERN. THE LOWEST CEILINGS
WILL BE FURTHER NORTH...BUT AXN AND STC IN PARTICULAR WILL BE THE
MOST VULNERABLE TO CEILINGS UNDER 2K FT. FOG POTENTIAL MAY BE
LIMITED DUE TO THE DECLINING DEW POINTS AND WESTERLY SURFACE
WINDS. BEYOND THE OVERNIGHT HOURS...VFR CONDITIONS WILL PREVAIL AS
JUST MID AND HIGH CLOUDS WILL BE LEFT OVER. OVERALL...RAISED VSBYS
AND CEILINGS...BUT DUE TO MODEL DISAGREEMENT FROM THE HRRR TO THE
RAP...THIS IS A LOWER CONFIDENCE FORECAST THAT HAS TAKEN THE HRRR
SIDE. IF THE RAP PANS OUT BETTER...WIDESPREAD LOW CEILINGS WILL
AFFECT MSP AND WESTERN WISCONSIN. THERE IS A CHANCE OF SHOWERS
TOMORROW AFTERNOON...BUT DID NOT INTRODUCE AT ANY TAF SITES AT
THIS TIME.
KMSP...CURRENTLY FORECASTING VFR CONDITIONS THROUGH THE TAF
PERIOD...BUT AGAIN THE RAP IS CONCERNING IN THAT IT WANTS TO BRING
IFR CIGS DOWN FROM THE NORTHWEST. CURRENT THINKING IS THAT IT IS
OVER ZEALOUS ON BOUNDARY LAYER MOISTURE SO HAVE TAKEN A MORE
OPTIMISTIC APPROACH. BEYOND MORNING...VFR CONDITIONS WILL PREVAIL.
/OUTLOOK FOR KMSP/
WED...VFR. WINDS NW AT 10KTS
TRU...VFR. WINDS N AT 10KTS.
FRI...VFR. WINDS SE AT 05KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...LS
AVIATION...SPD
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
655 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 00z TAFs through 00z Thursday Evening)
Issued at 655 PM CDT Wed Sep 11 2013
VFR conditions will prevail at the TAF sites thru the valid
period. An initial cold front, near KUIN already, will drop S thru
the area tonight, followed relatively quickly by a second cold
front very late tonight and into Thursday morning. While rain
should fade and then reform to an extent this evening across
northern MO and central IL, by the time it works its way down into
the I-70 corridor, the forcing that spawned it is expected to be
much less with little in the way of rain surviving. As a result,
have maintained the rain mention in KUIN for later this evening
and overnight but kept it out of the other TAF sites. The pair of
cold fronts are expected to progressively veer the winds to NW-N
by Thursday afternoon with some gust potential possible during the
afternoon.
Specifics for KSTL: VFR conditions will prevail thru the period.
Unfavorable time for a pair of cold fronts to be moving thru: the
first late tonight and the second late Thursday morning, and so
have kept the mention of rain out. There will likely be something
light in the area but confidence of occurrence at airport too low
at this time. Surface winds will progressively veer from to NW-N
by Thursday afternoon with the strongest winds during that
afternoon.
TES
&&
.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 NORTH PLATTE NE
958 PM CDT WED SEP 11 2013
.SYNOPSIS...
ISSUED AT 329 PM CDT WED SEP 11 2013
A SHORTWAVE TROUGH OVER CENTRAL CANADA WAS MOVING SOUTHEASTWARD
INTO THE NORTHERN TIER CONUS...HELPING TO AMPLIFY A LARGE LONGWAVE
TROUGH OVER MOST OF THE NORTHEASTERN US AND EASTERN CANADA.
FURTHER WEST A REX BLOCK WAS STARTING TO BREAK DOWN OVER THE
WESTERN CONUS...WITH A CLOSED LOW CENTERED NEAR LAS VEGAS BRINGING
PACIFIC MOISTURE NORTHWARD INTO THE EASTERN ROCKIES AND HIGH
PLAINS. AT THE SFC A WEAK FRONT WAS STALLED NEAR THE NE/KS
BORDER...WITH COOLER TEMPERATURES IN THE 70S AND MORE CLOUD COVER
TO THE NORTH OF FRONT.
&&
.SHORT TERM UPDATE...
ISSUED AT 954 PM CDT WED SEP 11 2013
BOTH THE NAM12 AND THE HRRR FORECAST SOUNDINGS INDICATE FOG IN THE
PLATTE RIVER VALLEY AND SOUTHWEST NEBRASKA. TEMPERATURES IN THE
UPPER 50S AND A UNIFORMLY MOIST BOUNDARY LAYER ARE FAVORABLE FOR
FOG. THE NORTH PLATTE SOUNDING THIS EVENING SUPPORTS THAT
SCENARIO...SO WE HAVE ADDED PATCHY FOG TO THE FORECAST IN THOSE
AREAS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 329 PM CDT WED SEP 11 2013
MODELS ARE IN AGREEMENT FOR A BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS ACROSS THE SOUTHERN HALF OF THE CWA THIS EVENING. A
WEAK SHORTWAVE WILL MOVE NORTH OUT OF EASTERN CO/WESTERN
KS...LIFTING AMPLE AMOUNTS OF MOISTURE OVER A STALLED FRONT JUST
SOUTH OF THE CWA. BEST CHANCES WILL BE IN OUR FAR SOUTHWEST
ZONES...GENERALLY SOUTH AND WEST OF A LINE FROM HAYES CENTER TO
OGALLALA. MONSOONAL PACIFIC MOISTURE FETCH ALOFT AND MOIST EASTERLY
FLOW NEAR THE SFC HAS LOCAL PWATS RUNNING CLOSE TO 2 STANDARD
DEVIATIONS ABOVE CLIMO. THIS COMBINED WITH SLOW NORTHERLY STORM
MOTIONS COULD PRODUCE LOCALLY HEAVY RAINFALL. MORE UNCERTAINTY
EXISTS FURTHER NORTH AS DRY AIR WILL IMPEDE NORTHWARD EXPANSION. THE
NORTHERN HALF OF THE CWA SHOULD REMAIN DRY.
SHOWER AND THUNDERSTORM CHANCES PERSIST INTO THURSDAY MORNING
ACROSS SOUTHWEST NEBRASKA. DRY AIR WILL CONTINUE TO SPILL INTO THE
NORTHERN AND EASTERN ZONES OF THE CWA AS THE REX BLOCK OUT WEST
CONTINUES TO BREAK DOWN AND HIGH PRESSURE ALOFT MOVES INTO THE
NORTHERN PLAINS. HAVE INCREASED HIGHS SLIGHTLY TO ACCOUNT FOR LATEST
MODEL TREND TO PUSH DRY AIR FURTHER WEST AND DECREASE CLOUD
COVERAGE. SLIGHT CHANCE POPS HAVE BEEN LIMITED TO FAR SOUTHWEST
NEBRASKA BY THE AFTERNOON HOURS WITH MOST MODEL SOLNS KEEPING THE
CWA DRY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 329 PM CDT WED SEP 11 2013
MODELS ARE IN FAIR AGREEMENT THROUGH THIS PERIOD. THURSDAY NIGHT
BEGINS WITH A LONGWAVE TROUGH OVER EASTERN CANADA...THROUGH THE
GREAT LAKES AND NORTHEAST CONUS. A LARGE RIDGE WILL SIT OVER THE
WESTERN HALF OF THE COUNTRY WHILE THE CUTOFF UPPER LOW DISCUSSED
EARLIER WILL BE SITUATED OVER NEVADA/IDAHO/UTAH.
THE MODELS CONTINUE TO TREND DRIER FOR THE FORECAST AREA DUE TO A
STRONG AND DRY AREA OF HIGH PRESSURE DROPPING SOUTHEAST OUT OF
CANADA. WHILE THE LARGE SCALE FLOW OVER THE LOCAL AREA WILL NOT
BE STRONG WITH THE UPPER RIDGE OVERHEAD...THE UPPER LOW WILL BE
PUSHING MONSOONAL MOISTURE UP ALONG THE ROCKY MOUNTAIN RANGE AND
THE HIGH PLAINS. THE NAM AND THE GFS ARE SHOWING PRECIPITABLE
WATER ABOVE 130 PERCENT OF NORMAL WITH THIS INFLUX OF MOISTURE SO
THINKING WHEREVER RAIN FALLS...COULD GET SOME HIGH AMOUNTS. THAT
BEING SAID...BY THURSDAY EVENING THE SURFACE HIGH LOOKS TO BE
CENTERED OVER EASTERN NORTH DAKOTA/NORTHERN MINNESOTA. THIS
CANADIAN AIRMASS WILL BE VERY DRY...WITH DEWPOINTS DOWN IN THE 40S
AND WILL COLLIDE WITH THE MOISTURE COMING INTO THE AREA FROM THE
SOUTH. THIS COLLISION WILL LIKELY LEAD TO A VERY NARROW GRADIENT
OF WET/CLOUDY CONDITIONS TO DRY/CLEAR CONDITIONS. THE MODEL TREND
IS SHOWING THE SURFACE HIGH BEING STRONGER AND DRIER THROUGH
FRIDAY...HAVE NARROWED THE GRADIENT BETWEEN NO PRECIPITATION
CHANCES TO SCATTERED CHANCES. THERE ARE SOME SOLUTIONS SHOWING THE
LOCAL AREA STAYING COMPLETELY DRY...BUT DON/T HAVE THE CONFIDENCE
TO CUT BACK THE CHANCES OVER THE WEST AND SOUTHWEST PARTS OF THE
FORECAST YET AS A FEW MODELS CONTINUE TO PUSH THE MOISTURE INTO
THE AREA. THE QUESTION WILL BE WHAT AIRMASS WILL WIN OUT.
MOVING INTO SATURDAY...THE UPPER LOW WILL BREAKDOWN WITH A DECENT
SHORTWAVE TROUGH MOVING ACROSS NEBRASKA. THIS SHOULD BRING A
HIGHER CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST
AREA. ALSO FOR SATURDAY...A WARM FRONT LOOKS TO MOVE THROUGH TO
BRING SOME WARMER AIR IN WITH TEMPERATURES POSSIBLY BACK INTO THE
UPPER 70S AND 80S. THE FRONT WILL BE PUSHED BACK SOUTH SATURDAY
NIGHT AND IS CURRENTLY LOOKING TO BE SITUATED ROUGHLY ALONG THE
NEBRASKA/KANSAS BORDER. ASSUMING THIS FRONT REMAINS STATIONARY AS
THE MODELS ARE INDICATING...RAIN CHANCES WILL BE ON THE INCREASE
FOR THE FIRST HALF OF THE WEEK...MAINLY ALONG AND SOUTH OF
INTERSTATE 80.
THERE CONTINUES TO BE GOOD MODEL AGREEMENT THROUGH THE MIDDLE PART
OF NEXT WEEK AS ANOTHER LONGWAVE TROUGH DROPS INTO THE GREAT
LAKES...BRINGING YET ANOTHER COLD FRONT AND SURFACE HIGH INTO THE
UPPER MISSISSIPPI RIVER VALLEY. THIS WOULD MEAN AUTUMN-LIKE
TEMPERATURES FOR NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 954 PM CDT WED SEP 11 2013
RADAR ECHOES IN SOUTHWEST NEBRASKA ARE SHOWING A WEAKENING
TREND...SO THE PROBABILITY OF THUNDER AT ANY ONE POINT IS VERY
LOW. STILL...SHOWERS CAN BE EXPECTED.
THE EVENING SOUNDING FROM LBF IS GIVING A BIT OF A FOG SIGNAL AND
SHORT RANGE FORECAST SOUNDINGS BEAR IT OUT. ALSO...RESIDUAL
MOISTURE FROM THE RAIN THIS EVENING HAS MOISTENED THE BOUNDARY
LAYER. THE AREA MOST LIKELY TO HAVE VISIBILITY BELOW 3SM WOULD
BE THE PLATTE RIVER VALLEY FROM NEAR OGA TO EAST OF LBF. AS A
RESULT WE HAVE AMENDED THE TERMINAL FORECAST AT LBF TO REFLECT
VERTICAL VISIBILITY LESS THAN 1000 FEET AGL AND VISIBILITY AROUND
1SM.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SPRINGER
SYNOPSIS...MARTIN
SHORT TERM...MARTIN
LONG TERM...BROOKS
AVIATION...SPRINGER
AREA FORECAST DISCUSSION
NWS HASTINGS NE
653 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 00Z KGRI TAF THROUGH 00Z THURSDAY EVENING)
ISSUED AT 645 PM CDT WED SEP 11 2013
PREVAILING VFR CONDITIONS ARE EXPECTED AT KGRI FOR THE NEXT 24
HOURS...ALTHOUGH SOME SHOWERS OR THUNDERSTORMS IN THE VICINITY OF
KGRI MAY BRIEFLY IMPACT THE TERMINAL THROUGH ABOUT 12/04Z...BEFORE
PUSHING SOUTHWARD...WITH SKIES SLOWLY CLEARING AND CEILINGS
LIFTING DURING THE OVERNIGHT HOURS. WINDS THROUGH THE OVERNIGHT
HOURS WILL BE GENERALLY LIGHT AND OUT OF THE NORTH...INCREASING TO
NEAR 10-12KTS OUT OF THE NORTHEAST DURING THE MORNING HOURS
THURSDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...SALTZMAN
AVIATION...SAR
AREA FORECAST DISCUSSION
NWS HASTINGS NE
317 PM CDT TUE SEP 10 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 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 109 PM CDT TUE SEP 10 2013
VFR9CONDITIONS ARE FORECAST THROUGH THE NEXT 24 HOURS.
CLEAR9SKIES WILL PERSIST THROUGH THE FIRST FEW HOURS OF THE
TAF...WITH INCREASING CLOUD COVER EXPECTED LATE THIS AFTERNOON
INTO WEDNESDAY MORNING. AT THIS TIME HOWEVER...THE CEILING AT GRI
IS NOT EXPECTED TO DROP BELOW 7000FT AGL. THE SURFACE WIND WILL
REMAIN LIGHT AND VARIABLE THROUGH THIS EVENING...BEFORE BECOMING
MORE ESTABLISHED FROM THE NORTHEAST...SUSTAINED AT AROUND
06KTS...STARTING 08Z WEDNESDAY. THERE IS A SLIGHT CHANCE OF SHOWER
AND THUNDERSTORM ACTIVITY LATE THIS AFTERNOON INTO THIS
EVENING...WITH A SOMEWHAT BETTER CHANCE DURING THE OVERNIGHT
HOURS. THAT BEING SAID...THE PROBABILITY OF SUCH ACTIVITY BEING
REALIZED AT GRI DURING THE TAF PERIOD IS TOO LOW FOR INCLUSION IN
THE TAF. SHOULD SHOWER AND/OR THUNDERSTORM ACTIVITY BE REALIZED AT
GRI...THEN VISIBILITY RESTRICTION IN PRECIPITATION WILL ALSO BE
POSSIBLE. BUT AGAIN...THE PROBABILITY OF SUCH ACTIVITY BEING
REALIZED AT GRI IS TOO LOW FOR INCLUSION IN THE TAF AND AS A
RESULT...VISIBILITY RESTRICTION IS NOT FORECAST AT GRI THROUGH THE
NEXT 24 HOURS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...BRYANT
LONG TERM...WESELY
AVIATION...BRYANT
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1251 PM CDT TUE SEP 10 2013
.AVIATION...
18Z TAFS FOR KOMA...KOFK...KLNK
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SFC CDFNT IS
THROUGH OFK AND WILL BE MOVING THRU OMA/LNK AROUND 00-01Z. THIS
WILL ALLOW FOR THE SW WINDS AT OMA/LNK TO BECOME NORTHWEST AND AN
INCREASE IN CLOUDS. WE MAY ALSO SEE A FEW ISO SHOWERS DEVELOP THIS
AFTERNOON ALONG THE COLD FRONT WHERE THE MIXING IS MAXIMIZED.
THESE SHOWERS MAY CONT INTO THE OVERNIGHT HOURS ALONG AND BEHIND
THE FRNT...BUT WILL JUST INCLUDE AN EVENING SHOWER IN THE FORECAST
ATTM DUE TO UNCERTAINTY IN COVERAGE LATE IN THE PERIOD. OTHERWISE
A GOOD DEAL OF MID AND HIGH LEVEL CLOUDS WILL CONT THRU THE
PERIOD.
BOUSTEAD
&&
PREV DISCUSSION... /ISSUED 356 AM CDT TUE SEP 10 2013/
DISCUSSION...
FORECAST CONCERNS THROUGH WEDNESDAY EVENING WILL BE PRECIPITATION
COVERAGE ALONG AND BEHIND THE COLD FRONT...THEN COOLER AND DRIER
WEATHER THURSDAY AND FRIDAY.
LINCOLN TIED THEIR RECORD OF 100 DEGREES MONDAY SET BACK IN 1931.
OMAHA EPPLEY JUST MISSED THE RECORD WITH A HIGH OF 99 AND NORFOLK
TOPPED OUT AT 97. OMAHA DID TIE A RECORD WARM MINIMUM FOR MONDAY
WITH 75 DEGREES (TIED WITH 1983/1931 AND 1927).
THE 00Z UPPER AIR MAPS HAD A 90KT H3 JET OVER NORTH DAKOTA WITH THE
H5 TROF SIMILARLY OVER NORTH DAKOTA...EXTENDING SOUTHWEST TOWARD
ARIZONA AND SOUTHERN CALIFORNIA. WARM H7 TEMPERATURES OF +10 TO +13C
EXTENDED ACROSS MUCH OF THE CENTRAL PLAINS...WITH THE THERMAL
GRADIENT FROM NORTHWEST NEBRASKA NORTHWARD ACROSS THE NORTHERN
PLAINS. H7 MOISTURE WAS NOTED ON THE WATER VAPOR IMAGERY AND UA
CHARTS FROM THE SOUTHWEST U.S. INTO THE UPPER MIDWEST. AT H85 THE
THERMAL RIDGE EXTENDED FROM SOUTHWEST NEBRASKA AND NORTHWEST KANSAS
NORTHEAST ACROSS THE FORECAST AREA WITH THE GRADIENT COMPARABLE TO
THE H7 PATTERN ACROSS THE DAKOTAS. ALTHOUGH THE SURFACE FRONT HAS
PUSHED INTO THE CWA AND THE OAX RADAR SHOWED A BOUNDARY
APPROACHING VALLEY WITH A WIND SHIFT AT KFET. THE SURFACE WINDS
WERE LIGHT FROM THE SOUTH AT KOFK AGAIN. THE WSR-88D MOSAIC HAD
THE LEADING EDGE OF THE PRECIPITATION FROM BROKEN BOW TO MITCHELL
SOUTH DAKOTA INTO SOUTHWEST MINNESOTA AT 06Z AND BY 0830Z THERE
WERE A FEW ECHOES IN BOYD AND KNOX COUNTIES...BUT NOT MUCH
REACHING THE GROUND. THE TREND ON THE IR SATELLITE LOOP SHOWED
EXPANDING/COOLING TOPS WITH THE PRECIPITATION. WPC HAD THE
EXCESSIVE DAY 1 RAINFALL OVER THE SOUTHWEST U.S. INTO WESTERN
COLORADO.
TODAY...THE NORTHERN PLAINS SHORT WAVE TROF WILL CONTINUE TO SHIFT
EAST ACROSS MINNESOTA INTO WISCONSIN...WHILE THE H5 LOW OVER THE
SOUTHWEST U.S. CUTS OFF. THIS WILL SLOW THE PUSH OF THE FRONT TO
SOMEWHERE ALONG I80 THROUGH 00Z. THE LOW LEVEL JET WILL STRENGTHEN
THIS ACROSS NORTH CENTRAL KANSAS INTO CENTRAL NEBRASKA AND THE
OAX FORECAST AREA...WITH ISENTROPIC LIFT AND SATURATION NORTH OF
THE FRONT IN PARTS OF NORTHEAST NEBRASKA. THE FORCING THIS
MORNING WILL MAINLY BE NORTHWEST OF THE FORECAST AREA BUT COULD
CLIP THE COUNTIES NEAR THE SD BORDER. FARTHER SOUTH THE FORCING
IS MORE NEGLIGIBLE. THE MODELS ARE HINTING AT A SECOND AREA OF
SATURATION FARTHER SOUTH CLOSER TO I80...BUT FOR NOW WILL INCREASE
CLOUDS AND MAY INCLUDE SPRINKLES MENTION. THIS AFTERNOON...THERE
IS WEAK CONVERGENCE ALONG THE FRONT AND A DECENT THERMAL BOUNDARY
IS EXPECTED. MODELS KEEP IS MAINLY DRY...HOWEVER HRRR DOES
GENERATE PRECIP ALONG THE FRONT. WILL MAINTAIN ISOLATED POPS ALONG
AND BEHIND THE FRONT WHERE DEEPER MOISTURE IS PRESENT WITH COOLING
ALOFT. TEMPERATURES TODAY SHOULD BE HOT AHEAD OF THE FRONT AND
WHERE THERE IS SUNSHINE. CLOUDS WILL IMPACT HIGHS...BUT GENERALLY
HAVE READINGS AROUND 80 NORTH NEAR THE SD BORDER TO THE UPPER 90S
NEAR THE MISSOURI AND KANSAS BORDERS.
TONIGHT THROUGH WEDNESDAY NIGHT THE MID TROPOSPHERIC TROF
DEEPENS OVER THE GREAT LAKES AND THE SURFACE FRONT IS PUSHED
FARTHER SOUTH. MONSOONAL MOISTURE STREAMING INTO THE ROCKIES AND
MAKING IT INTO THE PLAINS...POOLING AHEAD OF THE TROF COMBINE WITH
THE LOW...MID AND UPPER LEVEL SUPPORT WILL PROVIDE AT LEAST SOME
CHANCES FOR PRECIPITATION DURING THE PERIOD...ALTHOUGH COVERAGE
STILL LOOKS SCATTERED TO ISOLATED FOR THE COUNTY WARNING AREA.
HIGHS WEDNESDAY SHOULD RANGE FROM THE LOWER 80S NORTH TO THE LOWER
90S SOUTH.
COOL HIGH PRESSURE BUILDS IN FOR THURSDAY AND FRIDAY WITH MAINLY
DRY CONDITIONS. NEAR NORMAL HIGHS AROUND 80S THURSDAY WITH BELOW
NORMAL HIGHS IN THE 70S FRIDAY.
SATURDAY THROUGH TUESDAY...AS THE SURFACE HIGH
RETREATS...SOUTHWEST FLOW WILL RETURN DEEPER MOISTURE TO THE AREA
AND SHOWERS WILL TRY TO RETURN TO THE WESTERN CWA FRIDAY NIGHT.
SHORTWAVE TROF ENERGY ADVANCES INTO THE PLAINS SATURDAY THROUGH
SUNDAY...SO THERE APPEARS TO BE A GOOD SHOT AT PRECIPITATION
DURING THIS PERIOD. BEYOND THIS PERIOD...THERE IS NOT GOOD MODEL
CONSENSUS...BUT PRECIP CHANCES COULD LINGER INTO MONDAY. HIGHS
STILL BELOW NORMAL FOR MUCH OF THE EXTENDED.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
624 AM CDT TUE SEP 10 2013
.AVIATION...12Z TAFS FOR KOMA...KLNK AND KOFK. VFR CONDITIONS AT
ALL TAF SITES THROUGH THE PERIOD. A COLD FRONT WILL CONTINUE TO
SLOWLY DRIFT SOUTHWARD THROUGH THE REGION TODAY. THE FRONT WAS
ALREADY PAST KOFK WITH A LIGHT NORTHERLY WIND...AND SHOULD REACH
KOMA/KLNK BY 01-02Z. PRECIP CHANCES APPEAR BEST AT KOMA/KLNK WITH
THE ARRIVAL OF THE FRONT AND OPTED FOR A 6 HOUR WINDOW WITH A 30
PERCENT CHANCE OF SHOWERS AT THOSE 2 LOCATIONS. PRECIP CHANCES AT
KOFK APPEARED TOO LIMITED TO MENTION IN THE TAF AT THIS TIME.
DEWALD
&&
.PREV DISCUSSION... /ISSUED 356 AM CDT TUE SEP 10 2013/
DISCUSSION...
FORECAST CONCERNS THROUGH WEDNESDAY EVENING WILL BE PRECIPITATION
COVERAGE ALONG AND BEHIND THE COLD FRONT...THEN COOLER AND DRIER
WEATHER THURSDAY AND FRIDAY.
LINCOLN TIED THEIR RECORD OF 100 DEGREES MONDAY SET BACK IN 1931.
OMAHA EPPLEY JUST MISSED THE RECORD WITH A HIGH OF 99 AND NORFOLK
TOPPED OUT AT 97. OMAHA DID TIE A RECORD WARM MINIMUM FOR MONDAY
WITH 75 DEGREES (TIED WITH 1983/1931 AND 1927).
THE 00Z UPPER AIR MAPS HAD A 90KT H3 JET OVER NORTH DAKOTA WITH THE
H5 TROF SIMILARLY OVER NORTH DAKOTA...EXTENDING SOUTHWEST TOWARD
ARIZONA AND SOUTHERN CALIFORNIA. WARM H7 TEMPERATURES OF +10 TO +13C
EXTENDED ACROSS MUCH OF THE CENTRAL PLAINS...WITH THE THERMAL
GRADIENT FROM NORTHWEST NEBRASKA NORTHWARD ACROSS THE NORTHERN
PLAINS. H7 MOISTURE WAS NOTED ON THE WATER VAPOR IMAGERY AND UA
CHARTS FROM THE SOUTHWEST U.S. INTO THE UPPER MIDWEST. AT H85 THE
THERMAL RIDGE EXTENDED FROM SOUTHWEST NEBRASKA AND NORTHWEST KANSAS
NORTHEAST ACROSS THE FORECAST AREA WITH THE GRADIENT COMPARABLE TO
THE H7 PATTERN ACROSS THE DAKOTAS. ALTHOUGH THE SURFACE FRONT HAS
PUSHED INTO THE CWA AND THE OAX RADAR SHOWED A BOUNDARY
APPROACHING VALLEY WITH A WIND SHIFT AT KFET. THE SURFACE WINDS
WERE LIGHT FROM THE SOUTH AT KOFK AGAIN. THE WSR-88D MOSAIC HAD
THE LEADING EDGE OF THE PRECIPITATION FROM BROKEN BOW TO MITCHELL
SOUTH DAKOTA INTO SOUTHWEST MINNESOTA AT 06Z AND BY 0830Z THERE
WERE A FEW ECHOES IN BOYD AND KNOX COUNTIES...BUT NOT MUCH
REACHING THE GROUND. THE TREND ON THE IR SATELLITE LOOP SHOWED
EXPANDING/COOLING TOPS WITH THE PRECIPITATION. WPC HAD THE
EXCESSIVE DAY 1 RAINFALL OVER THE SOUTHWEST U.S. INTO WESTERN
COLORADO.
TODAY...THE NORTHERN PLAINS SHORT WAVE TROF WILL CONTINUE TO SHIFT
EAST ACROSS MINNESOTA INTO WISCONSIN...WHILE THE H5 LOW OVER THE
SOUTHWEST U.S. CUTS OFF. THIS WILL SLOW THE PUSH OF THE FRONT TO
SOMEWHERE ALONG I80 THROUGH 00Z. THE LOW LEVEL JET WILL STRENGTHEN
THIS ACROSS NORTH CENTRAL KANSAS INTO CENTRAL NEBRASKA AND THE
OAX FORECAST AREA...WITH ISENTROPIC LIFT AND SATURATION NORTH OF
THE FRONT IN PARTS OF NORTHEAST NEBRASKA. THE FORCING THIS
MORNING WILL MAINLY BE NORTHWEST OF THE FORECAST AREA BUT COULD
CLIP THE COUNTIES NEAR THE SD BORDER. FARTHER SOUTH THE FORCING
IS MORE NEGLIGIBLE. THE MODELS ARE HINTING AT A SECOND AREA OF
SATURATION FARTHER SOUTH CLOSER TO I80...BUT FOR NOW WILL INCREASE
CLOUDS AND MAY INCLUDE SPRINKLES MENTION. THIS AFTERNOON...THERE
IS WEAK CONVERGENCE ALONG THE FRONT AND A DECENT THERMAL BOUNDARY
IS EXPECTED. MODELS KEEP IS MAINLY DRY...HOWEVER HRRR DOES
GENERATE PRECIP ALONG THE FRONT. WILL MAINTAIN ISOLATED POPS ALONG
AND BEHIND THE FRONT WHERE DEEPER MOISTURE IS PRESENT WITH COOLING
ALOFT. TEMPERATURES TODAY SHOULD BE HOT AHEAD OF THE FRONT AND
WHERE THERE IS SUNSHINE. CLOUDS WILL IMPACT HIGHS...BUT GENERALLY
HAVE READINGS AROUND 80 NORTH NEAR THE SD BORDER TO THE UPPER 90S
NEAR THE MISSOURI AND KANSAS BORDERS.
TONIGHT THROUGH WEDNESDAY NIGHT THE MID TROPOSPHERIC TROF
DEEPENS OVER THE GREAT LAKES AND THE SURFACE FRONT IS PUSHED
FARTHER SOUTH. MONSOONAL MOISTURE STREAMING INTO THE ROCKIES AND
MAKING IT INTO THE PLAINS...POOLING AHEAD OF THE TROF COMBINE WITH
THE LOW...MID AND UPPER LEVEL SUPPORT WILL PROVIDE AT LEAST SOME
CHANCES FOR PRECIPITATION DURING THE PERIOD...ALTHOUGH COVERAGE
STILL LOOKS SCATTERED TO ISOLATED FOR THE COUNTY WARNING AREA.
HIGHS WEDNESDAY SHOULD RANGE FROM THE LOWER 80S NORTH TO THE LOWER
90S SOUTH.
COOL HIGH PRESSURE BUILDS IN FOR THURSDAY AND FRIDAY WITH MAINLY
DRY CONDITIONS. NEAR NORMAL HIGHS AROUND 80S THURSDAY WITH BELOW
NORMAL HIGHS IN THE 70S FRIDAY.
SATURDAY THROUGH TUESDAY...AS THE SURFACE HIGH
RETREATS...SOUTHWEST FLOW WILL RETURN DEEPER MOISTURE TO THE AREA
AND SHOWERS WILL TRY TO RETURN TO THE WESTERN CWA FRIDAY NIGHT.
SHORTWAVE TROF ENERGY ADVANCES INTO THE PLAINS SATURDAY THROUGH
SUNDAY...SO THERE APPEARS TO BE A GOOD SHOT AT PRECIPITATION
DURING THIS PERIOD. BEYOND THIS PERIOD...THERE IS NOT GOOD MODEL
CONSENSUS...BUT PRECIP CHANCES COULD LINGER INTO MONDAY. HIGHS
STILL BELOW NORMAL FOR MUCH OF THE EXTENDED.
ZAPOTOCNY
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
356 AM CDT TUE SEP 10 2013
.DISCUSSION...
FORECAST CONCERNS THROUGH WEDNESDAY EVENING WILL BE PRECIPITATION
COVERAGE ALONG AND BEHIND THE COLD FRONT...THEN COOLER AND DRIER
WEATHER THURSDAY AND FRIDAY.
LINCOLN TIED THEIR RECORD OF 100 DEGREES MONDAY SET BACK IN 1931.
OMAHA EPPLEY JUST MISSED THE RECORD WITH A HIGH OF 99 AND NORFOLK
TOPPED OUT AT 97. OMAHA DID TIE A RECORD WARM MINIMUM FOR MONDAY
WITH 75 DEGREES (TIED WITH 1983/1931 AND 1927).
THE 00Z UPPER AIR MAPS HAD A 90KT H3 JET OVER NORTH DAKOTA WITH THE
H5 TROF SIMILARLY OVER NORTH DAKOTA...EXTENDING SOUTHWEST TOWARD
ARIZONA AND SOUTHERN CALIFORNIA. WARM H7 TEMPERATURES OF +10 TO +13C
EXTENDED ACROSS MUCH OF THE CENTRAL PLAINS...WITH THE THERMAL
GRADIENT FROM NORTHWEST NEBRASKA NORTHWARD ACROSS THE NORTHERN
PLAINS. H7 MOISTURE WAS NOTED ON THE WATER VAPOR IMAGERY AND UA
CHARTS FROM THE SOUTHWEST U.S. INTO THE UPPER MIDWEST. AT H85 THE
THERMAL RIDGE EXTENDED FROM SOUTHWEST NEBRASKA AND NORTHWEST KANSAS
NORTHEAST ACROSS THE FORECAST AREA WITH THE GRADIENT COMPARABLE TO
THE H7 PATTERN ACROSS THE DAKOTAS. ALTHOUGH THE SURFACE FRONT HAS
PUSHED INTO THE CWA AND THE OAX RADAR SHOWED A BOUNDARY
APPROACHING VALLEY WITH A WIND SHIFT AT KFET. THE SURFACE WINDS
WERE LIGHT FROM THE SOUTH AT KOFK AGAIN. THE WSR-88D MOSAIC HAD
THE LEADING EDGE OF THE PRECIPITATION FROM BROKEN BOW TO MITCHELL
SOUTH DAKOTA INTO SOUTHWEST MINNESOTA AT 06Z AND BY 0830Z THERE
WERE A FEW ECHOES IN BOYD AND KNOX COUNTIES...BUT NOT MUCH
REACHING THE GROUND. THE TREND ON THE IR SATELLITE LOOP SHOWED
EXPANDING/COOLING TOPS WITH THE PRECIPITATION. WPC HAD THE
EXCESSIVE DAY 1 RAINFALL OVER THE SOUTHWEST U.S. INTO WESTERN
COLORADO.
TODAY...THE NORTHERN PLAINS SHORT WAVE TROF WILL CONTINUE TO SHIFT
EAST ACROSS MINNESOTA INTO WISCONSIN...WHILE THE H5 LOW OVER THE
SOUTHWEST U.S. CUTS OFF. THIS WILL SLOW THE PUSH OF THE FRONT TO
SOMEWHERE ALONG I80 THROUGH 00Z. THE LOW LEVEL JET WILL STRENGTHEN
THIS ACROSS NORTH CENTRAL KANSAS INTO CENTRAL NEBRASKA AND THE
OAX FORECAST AREA...WITH ISENTROPIC LIFT AND SATURATION NORTH OF
THE FRONT IN PARTS OF NORTHEAST NEBRASKA. THE FORCING THIS
MORNING WILL MAINLY BE NORTHWEST OF THE FORECAST AREA BUT COULD
CLIP THE COUNTIES NEAR THE SD BORDER. FARTHER SOUTH THE FORCING
IS MORE NEGLIGIBLE. THE MODELS ARE HINTING AT A SECOND AREA OF
SATURATION FARTHER SOUTH CLOSER TO I80...BUT FOR NOW WILL INCREASE
CLOUDS AND MAY INCLUDE SPRINKLES MENTION. THIS AFTERNOON...THERE
IS WEAK CONVERGENCE ALONG THE FRONT AND A DECENT THERMAL BOUNDARY
IS EXPECTED. MODELS KEEP IS MAINLY DRY...HOWEVER HRRR DOES
GENERATE PRECIP ALONG THE FRONT. WILL MAINTAIN ISOLATED POPS ALONG
AND BEHIND THE FRONT WHERE DEEPER MOISTURE IS PRESENT WITH COOLING
ALOFT. TEMPERATURES TODAY SHOULD BE HOT AHEAD OF THE FRONT AND
WHERE THERE IS SUNSHINE. CLOUDS WILL IMPACT HIGHS...BUT GENERALLY
HAVE READINGS AROUND 80 NORTH NEAR THE SD BORDER TO THE UPPER 90S
NEAR THE MISSOURI AND KANSAS BORDERS.
TONIGHT THROUGH WEDNESDAY NIGHT THE MID TROPOSPHERIC TROF
DEEPENS OVER THE GREAT LAKES AND THE SURFACE FRONT IS PUSHED
FARTHER SOUTH. MONSOONAL MOISTURE STREAMING INTO THE ROCKIES AND
MAKING IT INTO THE PLAINS...POOLING AHEAD OF THE TROF COMBINE WITH
THE LOW...MID AND UPPER LEVEL SUPPORT WILL PROVIDE AT LEAST SOME
CHANCES FOR PRECIPITATION DURING THE PERIOD...ALTHOUGH COVERAGE
STILL LOOKS SCATTERED TO ISOLATED FOR THE COUNTY WARNING AREA.
HIGHS WEDNESDAY SHOULD RANGE FROM THE LOWER 80S NORTH TO THE LOWER
90S SOUTH.
COOL HIGH PRESSURE BUILDS IN FOR THURSDAY AND FRIDAY WITH MAINLY
DRY CONDITIONS. NEAR NORMAL HIGHS AROUND 80S THURSDAY WITH BELOW
NORMAL HIGHS IN THE 70S FRIDAY.
SATURDAY THROUGH TUESDAY...AS THE SURFACE HIGH
RETREATS...SOUTHWEST FLOW WILL RETURN DEEPER MOISTURE TO THE AREA
AND SHOWERS WILL TRY TO RETURN TO THE WESTERN CWA FRIDAY NIGHT.
SHORTWAVE TROF ENERGY ADVANCES INTO THE PLAINS SATURDAY THROUGH
SUNDAY...SO THERE APPEARS TO BE A GOOD SHOT AT PRECIPITATION
DURING THIS PERIOD. BEYOND THIS PERIOD...THERE IS NOT GOOD MODEL
CONSENSUS...BUT PRECIP CHANCES COULD LINGER INTO MONDAY. HIGHS
STILL BELOW NORMAL FOR MUCH OF THE EXTENDED.
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK...AND KOFK.
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF CYCLE. WINDS HAVE
GONE LIGHT/VARIABLE AT KOFK...AND WILL INCREASE OUT OF THE
NORTHEAST BY MID-MORNING. KEPT SHRA/TSRA MENTION OUT OF THE TAF
FOR NOW WITH UNCERTAINTY ON IF/WHEN SHRA WILL MOVE INTO NORTHEAST
NEB...AND COVERAGE OF ANY SHRA THAT DOES MOVE IN. FRONT SHOULD
REMAIN NORTH OF KOMA/KLNK UNTIL EVENING...WITH WINDS BECOMING
LIGHT/VARIABLE AFTER 02Z KOMA/CLOSER TO MIDNIGHT KLNK AS FRONT
APPROACHES. INCLUDED MID-LEVEL CEILINGS...BUT AGAIN...NO SHRA
MENTION AT THIS POINT UNTIL CONFIDENCE ON COVERAGE IMPROVES.
MAYES
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1105 PM EDT WED SEP 11 2013
.SYNOPSIS...
A COLD FRONT WILL DROP ACROSS THE REGION...BRINGING SHOWERS AND
THUNDERSTORMS TONIGHT AND THURSDAY. AFTER A COUPLE OF VERY WARM
TO HOT DAYS...EXPECT A SIGNIFICANT DROP IN TEMPERATURES FOLLOWING
THE COLD FRONT...WITH HIGH TEMPERATURES EXPECTED TO BE WELL BELOW
AVERAGE ON FRIDAY AND SATURDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
A COMPLEX OF THUNDERSTORMS WILL MOVE INTO WESTERN NEW YORK THROUGH
THE EARLY MORNING HOURS...WITH THE LEADING EDGE EXPECTED TO REACH
THE BUFFALO METRO AREA JUST SHY OF MIDNIGHT. ITS INTERESTING TO
NOTE THAT RUNS OF THE HRRR HAVE NOT CAPTURED THIS WELL AT
ALL...HOWEVER THE 00Z NAM AND 12Z RGEM HAVE A FAIRLY GOOD HANDLE
ON IT. THIS COMPLEX SHOULD PRETTY MUCH TRACK ENE WITH THE UPPER
LEVEL FLOW...AND MOVE ACROSS NORTHERN PORTIONS OF THE CWA DURING
THE EARLY MORNING HOURS. WITH GREATER INSTABILITY TO THE
SOUTH...EXPECT THUNDERSTORMS TO EXTEND SOUTHWARD OF THE MAIN
COMPLEX...AND INTO WESTERN PORTIONS OF THE SOUTHERN TIER. THE
PRIMARY IMPACT WILL BE HEAVY RAIN FROM THE THUNDERSTORMS...BUT
SOME EMBEDDED STRONG STORMS HAVE STRONG GUSTY WINDS AS WELL.
MEANWHILE...THE COLD FRONTAL BOUNDARY WILL CONTINUE TO DROP SE
ACROSS THE REGION ON THURSDAY...WITH THE BEST CHANCE FOR SHOWERS
ALONG AND AHEAD OF THIS BOUNDARY. EXPECT FAIRLY WIDESPREAD
ACTIVITY THURSDAY MORNING...WITH THIS SHIFTING TO THE SOUTH DURING
THE AFTERNOON HOURS.
TEMPERATURES WILL CONTINUE TO BE ON THE WARM SIDE TONIGHT...WITH
LOWS IN THE UPPER 60S TO LOWER 70S. THEN FOR TOMORROW...CLOUD
COVER AND SHOWERS SHOULD KEEP TEMPERATURES IN THE 70S. IF
TEMPERATURES REMAIN WARM THROUGH MIDNIGHT...BOTH BUFFALO AND
ROCHESTER STAND TO BREAK THE RECORD FOR WARMEST LOW TEMPERATURES.
THE RECORD FOR FOR BUFFALO IS 72 (1931)...AND FOR ROCHESTER IS
71 (1931).
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
NOTABLY COOLER AND LESS HUMID CONDITIONS WILL BE PLACE DURING THIS
PERIOD AS A LONGWAVE TROUGH WILL BE IN PLACE ACROSS THE EASTERN HALF
OF NORTH AMERICA. THIS WILL RESULT IN BELOW NORMAL TEMPERATURES...BY
AS MUCH AS 10 DEG F...WHILE HIGH PRESSURE OF CANADIAN ORIGIN WILL
PROVIDE US WITH PLENTY OF DRY WEATHER. THE EXCEPTION TO THE FAIR
WEATHER WILL BE FOUND EARLY IN THIS TIME FRAME WHEN NUISANCE SHOWERS
WILL BE FOUND OVER PARTS OF THE REGION.
A SHORTWAVE OVER NUNAVUT AT MIDDAY WILL DIG SOUTHEAST ACROSS WESTERN
ONTARIO AND THE UPPER GREAT LAKES TONIGHT AND THURSDAY...AMPLIFYING
A BROAD BASED TROUGH THAT IS ALREADY IN PLACE. AS THIS FEATURE
ROUNDS THE BASE OF THE LONGWAVE TROUGH OVER THE LOWER GREAT LAKES
THURSDAY NIGHT...IT MAY HELP TO ENHANCE WHAT OTHERWISE WOULD BE A
WEAK LAKE RESPONSE FROM THE FRESH CHILLY AIRMASS. THIS WILL RESULT
IN SOME LIGHT SHOWER ACTIVITY...WHICH WILL BE COVERED WITH CHC POPS.
CONTINUED COLD ADVECTION THURSDAY NIGHT WILL ALLOW H85 TEMPS TO DROP
TO BETWEEN ZERO AND 4C OVER OUR FORECAST AREA...SO OUR CORRESPONDING
NR SFC TEMPS WILL INTO THE UPPER 40S AND LOWER 50S. THESE READINGS
WILL BE 20 DEG F LOWER THAN THOSE FROM THE PREVIOUS FEW NIGHTS WHEN
MERCURY READINGS WERE HELD UP IN THE 70S FOR MOST SITES.
FRIDAY WILL BE QUITE COOL ACROSS OUR FORECAST AREA. EVEN IF THE
AIRMASS WERE FULLY MIXED...H85 TEMPS IN THE VCNTY OF ZERO C WILL
ONLY SUPPORT AFTERNOON TEMPS IN THE MID TO UPPER 50S (NR 60 CLOSE TO
THE WARMER LKS). THE MORE AUTUMN-LIKE MERCURY LEVELS WOULD NOT BE
COMPLETE THOUGH WITHOUT CLOUDS AND THE CHANCE FOR SHOWERS. A
SECOND...TWIN MID LEVEL DISTURBANCE WILL SWEEP THROUGH THE BASE OF
THE LONGWAVE TROUGH DURING THE COURSE OF THE DAY. THIS FEATURE WILL
COMBINE WITH A WEALTH OF LOW LEVEL MOISTURE AND LAKE INDUCED/
DIURNALLY ENHANCED LOW LEVEL INSTABILITY TO PRODUCE MOSTLY CLOUDY
SKIES ALONG WITH SOME MORE SCATTERED LIGHT SHOWERS. THE COVERAGE AND
INTENSITY OF THESE SHOWERS WILL BE SUPPRESSED BY A 2-3 DEG CAP
SUPPLIED BY STRONG HIGH PRESSURE CENTERED OVER THE UPPER GREAT LAKES.
FAIRLY SIGNIFICANT HGT RISES IN THE WAKE OF THE SECOND SHORTWAVE...
COUPLED WITH MID LEVEL DRYING...WILL BRING AN END TO THE SHOWERS IN
MOST AREAS LATE FRIDAY OR EARLY FRIDAY EVENING. THE EXCEPTION WILL
COME SOUTHEAST OF LK ONTARIO WHERE SOME NUISANCE LAKE INDUCED SHOWER
ACTIVITY WILL BE POSSIBLE. IT WILL BE RATHER CHILLY FRIDAY NIGHT
WITH TEMPS FALLING INTO THE UPPER 30S TO MID 40S.
EXPANSIVE SFC HIGH PRESSURE WILL DRIFT SOUTHEAST ACROSS THE UPPER
OHIO VALLEY AND MIDDLE ATLANTIC STATES SATURDAY AND SATURDAY NIGHT.
THE ASSOCIATED SUBSIDENCE AND MID LEVEL DRYING SHOULD LEAD TO
BEAUTIFUL EARLY FALL WEATHER FOR THE START OF THE WEEKEND...WITH
WEAK WARM ADVECTION PUSHING SATURDAY AFTERNOON TEMPERATURES BACK
ABOVE 60 FOR MOST AREAS. MEANWHILE...IT WILL BE SEASONABLY CHILLY
SATURDAY NIGHT WITH MINS RANGING FROM THE MID 40S ACROSS THE LAKE
PLAINS TO BETWEEN 35 AND 40 IN THE SRN TIER VALLEYS WHERE THERE
COULD BE A TOUCH OF FROST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE LONG RANGE PORTION OF THE FORECAST PACKAGE WILL REMAIN
UNEVENTFUL...AS RIDGING OVER THE WESTERN HALF OF THE COUNTRY WILL
PUSH EAST ACROSS THE PLAINS TO THE UPPER GREAT LAKES. MEANWHILE...
THE CORRESPONDING SFC HIGH WILL SETTLE SOUTHEAST FROM THE PLAINS OF
SASKATCHEWAN...EVENTUALLY ENDING UP ALONG THE MID ATLANTIC COAST BY
THE MIDDLE OF NEXT WEEK. THIS WILL KEEP OUR REGION GENERALLY RAIN
FREE...WITH JUST THE PASSAGE OF A MOISTURE STARVED COLD FRONT SUNDAY
NIGHT BEING THE ONLY POSSIBLE WEATHER MAKER FOR THIS TIME PERIOD.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
FOR THE 03Z TAF CYCLE...EXPECT THUNDERSTORMS TO MOVE ACROSS THE
REGION DURING THE EARLY MORNING HOURS. THIS WILL LIKELY BRING
THUNDERSTORMS TO ALL TAF SITES DURING THE OVERNIGHT PERIOD. BRIEF
HEAVY DOWNPOURS AND GUSTY WINDS ARE POSSIBLE.
ON THURSDAY...A COLD FRONT WILL CONTINUE TO DROP ACROSS THE
REGION...WITH STEADY SHOWERS LIKELY TO DROP SOUTHWARD DURING THE
DAY. THIS WILL BRING PERIODS OF MVFR/IFR CONDITIONS IN SHOWERS AND
THUNDERSTORMS...WITH IMPROVING CONDITIONS EXPECTED LATE IN THE DAY.
OUTLOOK...
THURSDAY NIGHT...MAINLY VFR. PATCHY FOG POSSIBLE.
FRIDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
SATURDAY THROUGH MONDAY...VFR.
&&
.MARINE...
WINDS WILL REMAIN MODEST...BUT SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THIS EVENING AND TONIGHT. SCATTERED THUNDERSTORMS
ARE POSSIBLE LATE IN THE DAY...BUT THE BEST CHANCE FOR STORMS WILL
BE LATER TONIGHT AND THURSDAY WHEN A COLD FRONT PUSHES EAST ACROSS
THE LOWER GREAT LAKES. A NORTHWEST FLOW OF NOTICEABLY COOLER AIR
BEHIND THE FRONT AIR MAY RESULT IN SMALL CRAFT ADVISORY CONDITIONS
LATE THURSDAY INTO FRIDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WCH
NEAR TERM...APFFEL/WCH
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...APFFEL/WCH
MARINE...APFFEL/TJP/WCH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
751 PM EDT WED SEP 11 2013
.SYNOPSIS...
A FEW SHOWERS AND THUNDERSTORMS WILL LINGER INTO THIS
EVENING...WITH MORE WIDESPREAD SHOWERS AND THUNDERSTORMS EXPECTED
LATE TONIGHT AND THURSDAY AS A COLD FRONT PUSHES EAST ACROSS NEW
YORK STATE. AFTER A COUPLE OF VERY WARM TO HOT DAYS...EXPECT A
SIGNIFICANT DROP IN TEMPERATURES FOLLOWING THE COLD FRONT...WITH
HIGH TEMPERATURES EXPECTED TO BE WELL BELOW AVERAGE ON FRIDAY AND
SATURDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
FOR THE EVENING HOURS...SHOWERS AND THUNDERSTORMS ALONG THE FAR
EASTERN FRINGE OF OUR CWA...EXTENDING FROM ALLEGANY COUNTY TO
EASTERN LEWIS COUNTY. THESE THUNDERSTORMS WILL CONTINUE TO SLOWLY
SLIDE ENE...AND WEAKEN AS THEY EXIT TO THE EAST DURING THE EVENING
HOURS. UNTIL THEN...THEY WILL DROP HEAVY RAINS...AND HAVE THE
POTENTIAL TO PRODUCE DAMAGING WINDS AND LARGE HAIL. TO THE WEST OF
THIS LINE...THE THREAT HAS DIMINISHED...FOR THE TIME BEING AT
LEAST.
IR SATELLITE SHOWS WHAT APPEARS TO BE A DEVELOPING CONVECTIVE
COMPLEX ACROSS SE MICHIGAN AND SW ONTARIO PROVINCE. ITS
INTERESTING TO NOTE THAT RUNS OF THE HRRR HAVE NOT CAPTURED THIS
WELL AT ALL...HOWEVER THE 18Z NAM/12Z RGEM HAVE A MUCH BETTER
HANDLE. EXPECT THIS AREA TO TRACK ENE WITH THE UPPER LEVEL
FLOW...AND TO MOVE ACROSS LAKE ONTARIO AFTER MIDNIGHT TONIGHT.
SOMETIMES CONVECTIVE COMPLEXES TEND TO TRACK A BIT TO THE RIGHT OF
MODEL GUIDANCE AS THE SYSTEM SHIFTS TOWARD THE MORE UNSTABLE AIR
IN THE WARM SECTOR. BECAUSE OF THIS...WILL HEDGE POPS/QPF A BIT
HIGHER ON THE SOUTHERN FLANK OF THE FORECAST. IF THIS COMPLEX
HOLDS TOGETHER AS EXPECTED...IT WILL BRING ACTIVE WEATHER TO
NORTHERN PORTIONS OF THE CWA...GENERALLY FROM BUFFALO-OSWEGO
NORTHWARD. THUNDERSTORMS WILL BRING HEAVY RAINS...AND POSSIBLY
STRONG GUSTY WINDS.
MEANWHILE...THE COLD FRONTAL BOUNDARY WILL CONTINUE TO DROP SE
ACROSS THE REGION ON THURSDAY...WITH THE BEST CHANCE FOR SHOWERS
ALONG AND AHEAD OF THIS BOUNDARY. EXPECT FAIRLY WIDESPREAD
ACTIVITY THURSDAY MORNING...WITH THIS SHIFTING TO THE SOUTH DURING
THE AFTERNOON HOURS.
TEMPERATURES WILL CONTINUE TO BE ON THE WARM SIDE TONIGHT...WITH
LOWS IN THE UPPER 60S TO LOWER 70S. THEN FOR TOMORROW...CLOUD
COVER AND SHOWERS SHOULD KEEP TEMPERATURES IN THE 70S.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
NOTABLY COOLER AND LESS HUMID CONDITIONS WILL BE PLACE DURING THIS
PERIOD AS A LONGWAVE TROUGH WILL BE IN PLACE ACROSS THE EASTERN HALF
OF NORTH AMERICA. THIS WILL RESULT IN BELOW NORMAL TEMPERATURES...BY
AS MUCH AS 10 DEG F...WHILE HIGH PRESSURE OF CANADIAN ORIGIN WILL
PROVIDE US WITH PLENTY OF DRY WEATHER. THE EXCEPTION TO THE FAIR
WEATHER WILL BE FOUND EARLY IN THIS TIME FRAME WHEN NUISANCE SHOWERS
WILL BE FOUND OVER PARTS OF THE REGION.
A SHORTWAVE OVER NUNAVUT AT MIDDAY WILL DIG SOUTHEAST ACROSS WESTERN
ONTARIO AND THE UPPER GREAT LAKES TONIGHT AND THURSDAY...AMPLIFYING
A BROAD BASED TROUGH THAT IS ALREADY IN PLACE. AS THIS FEATURE
ROUNDS THE BASE OF THE LONGWAVE TROUGH OVER THE LOWER GREAT LAKES
THURSDAY NIGHT...IT MAY HELP TO ENHANCE WHAT OTHERWISE WOULD BE A
WEAK LAKE RESPONSE FROM THE FRESH CHILLY AIRMASS. THIS WILL RESULT
IN SOME LIGHT SHOWER ACTIVITY...WHICH WILL BE COVERED WITH CHC POPS.
CONTINUED COLD ADVECTION THURSDAY NIGHT WILL ALLOW H85 TEMPS TO DROP
TO BETWEEN ZERO AND 4C OVER OUR FORECAST AREA...SO OUR CORRESPONDING
NR SFC TEMPS WILL INTO THE UPPER 40S AND LOWER 50S. THESE READINGS
WILL BE 20 DEG F LOWER THAN THOSE FROM THE PREVIOUS FEW NIGHTS WHEN
MERCURY READINGS WERE HELD UP IN THE 70S FOR MOST SITES.
FRIDAY WILL BE QUITE COOL ACROSS OUR FORECAST AREA. EVEN IF THE
AIRMASS WERE FULLY MIXED...H85 TEMPS IN THE VCNTY OF ZERO C WILL
ONLY SUPPORT AFTERNOON TEMPS IN THE MID TO UPPER 50S (NR 60 CLOSE TO
THE WARMER LKS). THE MORE AUTUMN-LIKE MERCURY LEVELS WOULD NOT BE
COMPLETE THOUGH WITHOUT CLOUDS AND THE CHANCE FOR SHOWERS. A
SECOND...TWIN MID LEVEL DISTURBANCE WILL SWEEP THROUGH THE BASE OF
THE LONGWAVE TROUGH DURING THE COURSE OF THE DAY. THIS FEATURE WILL
COMBINE WITH A WEALTH OF LOW LEVEL MOISTURE AND LAKE INDUCED/
DIURNALLY ENHANCED LOW LEVEL INSTABILITY TO PRODUCE MOSTLY CLOUDY
SKIES ALONG WITH SOME MORE SCATTERED LIGHT SHOWERS. THE COVERAGE AND
INTENSITY OF THESE SHOWERS WILL BE SUPPRESSED BY A 2-3 DEG CAP
SUPPLIED BY STRONG HIGH PRESSURE CENTERED OVER THE UPPER GREAT LAKES.
FAIRLY SIGNIFICANT HGT RISES IN THE WAKE OF THE SECOND SHORTWAVE...
COUPLED WITH MID LEVEL DRYING...WILL BRING AN END TO THE SHOWERS IN
MOST AREAS LATE FRIDAY OR EARLY FRIDAY EVENING. THE EXCEPTION WILL
COME SOUTHEAST OF LK ONTARIO WHERE SOME NUISANCE LAKE INDUCED SHOWER
ACTIVITY WILL BE POSSIBLE. IT WILL BE RATHER CHILLY FRIDAY NIGHT
WITH TEMPS FALLING INTO THE UPPER 30S TO MID 40S.
EXPANSIVE SFC HIGH PRESSURE WILL DRIFT SOUTHEAST ACROSS THE UPPER
OHIO VALLEY AND MIDDLE ATLANTIC STATES SATURDAY AND SATURDAY NIGHT.
THE ASSOCIATED SUBSIDENCE AND MID LEVEL DRYING SHOULD LEAD TO
BEAUTIFUL EARLY FALL WEATHER FOR THE START OF THE WEEKEND...WITH
WEAK WARM ADVECTION PUSHING SATURDAY AFTERNOON TEMPERATURES BACK
ABOVE 60 FOR MOST AREAS. MEANWHILE...IT WILL BE SEASONABLY CHILLY
SATURDAY NIGHT WITH MINS RANGING FROM THE MID 40S ACROSS THE LAKE
PLAINS TO BETWEEN 35 AND 40 IN THE SRN TIER VALLEYS WHERE THERE
COULD BE A TOUCH OF FROST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE LONG RANGE PORTION OF THE FORECAST PACKAGE WILL REMAIN
UNEVENTFUL...AS RIDGING OVER THE WESTERN HALF OF THE COUNTRY WILL
PUSH EAST ACROSS THE PLAINS TO THE UPPER GREAT LAKES. MEANWHILE...
THE CORRESPONDING SFC HIGH WILL SETTLE SOUTHEAST FROM THE PLAINS OF
SASKATCHEWAN...EVENTUALLY ENDING UP ALONG THE MID ATLANTIC COAST BY
THE MIDDLE OF NEXT WEEK. THIS WILL KEEP OUR REGION GENERALLY RAIN
FREE...WITH JUST THE PASSAGE OF A MOISTURE STARVED COLD FRONT SUNDAY
NIGHT BEING THE ONLY POSSIBLE WEATHER MAKER FOR THIS TIME PERIOD.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
FOR THE 00Z TAF CYCLE...EXPECT THUNDERSTORMS TO STAY TO THE NW AND
SE OF THE TAF SITES AS A SW FLOW TEMPORARILY KEEPS TERMINAL SITES
DRY. THIS IS LIKELY TO END AS A DEVELOPING CONVECTIVE COMPLEX
ACROSS SE MICHIGAN AND SW ONTARIO PROVINCE...WHICH IS FORECAST TO
MOVE INTO FAR WESTERN NEW YORK DURING THE EARLY MORNING HOURS.
THIS WILL LIKELY BRING THUNDERSTORMS TO BUF/IAG/ART...AND
EVENTUALLY ROC/JHW AS A FRONTAL BOUNDARY SLIDES SOUTH.
ON THURSDAY...A COLD FRONT WILL CONTINUE TO DROP ACROSS THE
REGION...WITH STEADY SHOWERS LIKELY TO DROP SOUTHWARD DURING THE
DAY. THIS WILL BRING PERIODS OF MVFR/IFR CONDITIONS IN SHOWERS AND
THUNDERSTORMS...WITH IMPROVING CONDITIONS EXPECTED LATE IN THE DAY.
OUTLOOK...
THURSDAY NIGHT...MAINLY VFR. PATCHY FOG POSSIBLE.
FRIDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
SATURDAY THROUGH MONDAY...VFR.
&&
.MARINE...
WINDS WILL REMAIN MODEST...BUT SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THIS EVENING AND TONIGHT. SCATTERED THUNDERSTORMS
ARE POSSIBLE LATE IN THE DAY...BUT THE BEST CHANCE FOR STORMS WILL
BE LATER TONIGHT AND THURSDAY WHEN A COLD FRONT PUSHES EAST ACROSS
THE LOWER GREAT LAKES. A NORTHWEST FLOW OF NOTICEABLY COOLER AIR
BEHIND THE FRONT AIR MAY RESULT IN SMALL CRAFT ADVISORY CONDITIONS
LATE THURSDAY INTO FRIDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WCH
NEAR TERM...APFFEL/WCH
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...APFFEL/WCH
MARINE...APFFEL/TJP/WCH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
417 AM EDT TUE SEP 10 2013
.SYNOPSIS...
A WARM FRONT WILL CONTINUE TO LIFT NORTHEASTWARD ACROSS THE EASTERN
GREAT LAKES REGION THIS MORNING...ACCOMPANIED WITH SHOWERS AND
THUNDERSTORMS. BEHIND THIS WARM FRONT CLOUDS WILL BREAK FOR SOME
SUNSHINE LATER TODAY WHICH WILL AID IN AN UNSEASONABLY HOT AND
MUGGY AFTERNOON. THESE VERY WARM AND HUMID CONDITIONS WILL PERSIST
THROUGH WEDNESDAY NIGHT. EXPECT SHOWERS AND THUNDERSTORMS TO BREAK
OUT WEDNESDAY NIGHT AND THURSDAY AHEAD OF A COLD FRONT THAT WILL
BRING A RETURN TO MUCH COOLER WEATHER BY THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
REGIONAL RADARS AND SATELLITE IMAGERY THIS MORNING DISPLAY A LARGE
MCS NEAR GEORGIAN BAY AND ADVANCING SOUTH AND EASTWARD ACROSS
SOUTHERN CANADA AND JUST NORTH OF LAKE ONTARIO. SOUTH OF THIS
FEATURE A FEW SHOWERS ARE BLOSSOMING ACROSS THE SOUTHERN PENINSULA
OF ONTARIO AND DRIFTING ACROSS LAKE ERIE. AT THE SURFACE A WARM FRONT IS
PUSHING NORTHWARD FROM THE OHIO VALLEY AND INTO WESTERN NEW YORK
THIS MORNING. TODAY WILL BE AN ACTIVE DAY WITH SHOWERS AND
THUNDERSTORMS PRIMARILY THROUGH THE MORNING HOURS FOR THE CWA...WITH
ATTENTION THEN TURNING TO THE GUSTY WINDS AND AFTERNOON HEAT.
THUNDERSTORMS...
MOISTURE ADVECTION BEHIND THE LIFTING WARM FRONT...ALONG WITH
ISENTROPIC UPGLIDE ALONG A 35 TO 40 KNOT LOW LEVEL JET WILL CONTINUE
TO FUEL THE POTENTIAL FOR SOME SHOWERS AND A FEW THUNDERSTORMS
ACROSS WNY THIS EARLY MORNING. WITH THE LATEST RADAR IMAGES
DISPLAYING A FEW CONVECTIVE SHOWERS ACROSS CANADA...AND WITH SUPPORT
FROM THE MESO SCALE MODELS OF THE HRRR AND YESTERDAYS SSEO...EXPECT
THIS ACTIVITY TO INCREASE IN COVERAGE AREA SOME THIS MORNING AS IT
DRIFTS EAST-SOUTHEASTWARD ACROSS WNY. AFTER SUNRISE WITH DAYTIME
MIXING...AND LOWERING DEW POINTS TO THE EAST EXPECT THIS SCATTERED
ACTIVITY TO QUICKLY DIMINISH IN COVERAGE AREA AS IT SHIFTS DEEPER
INTO WESTERN NEW YORK.
ALSO THIS MORNING EXPECT THE LARGE MCS OVER SOUTHERN CANADA TO DROP
SOUTHEASTWARD...FOLLOWING A STREAM OF HIGHER THETA-E AIR AND ALONG
THE 1000-500 THICKNESS LINES. THIS TRACK WILL BRING A CLUSTER OF
SHOWERS AND THUNDERSTORMS TO LAKE ONTARIO...AND THEN THROUGH THE
EASTERN LAKE ONTARIO REGION. ON THE SOUTHERN PERIPHERY SOME ACTIVITY
MAY BRUSH BY THE LINE OF COUNTIES JUST SOUTH OF LAKE
ONTARIO...ESPECIALLY THE WAYNE-CAYUGA CORRIDOR. THE CONVECTIVE
ACTIVITY WILL ENTER THE CWA BEFORE DAWN AND CLEAR THROUGH THE CWA
WITHIN A FEW HOURS AFTER DAWN.
LATER IN THE DAY...AND BEHIND THE MCS...THERE WILL ALSO BE A CHANCE
FOR A FEW THUNDERSTORMS ALONG THE WARM FRONTAL BOUNDARY THAT WILL
STALL NEAR THE U.S. AND CANADIAN BORDER. AREAS POSSIBLE FOR STORMS
WILL LARGELY BE CONFINED TO THE EASTERN LAKE ONTARIO REGION. IN
ADDITION TO THE SBCAPES OF 1000 TO 1500 J/KG THROUGH THIS
REGION...THERE WILL BE A SLIGHTLY STRONGER LLJ IN ADDITION TO THE
WARM FRONTAL BOUNDARY THAT COULD CONTINUE TO INITIATE CONVECTION.
WITH THE PASSAGE OF THE LARGE MCS FEEL THAT SHOWER AND THUNDERSTORM
ACTIVITY BEHIND THIS FEATURE WILL JUST BE SCATTERED IN NATURE AND
FOCUS MORE UPON THE INLAND HILLS AND WILL QUICKLY DROP POPS DOWN TO
THE CHANCE RANGE FROM MID MORNING ONWARD. WITH DECENT HELICITY OF
200 T0 400 M2/S2...DECENT DIRECTIONAL SHEER AND CONTINUED 35 TO 40
KNOT LLJ AROUND 925 HPA THERE WILL BE THE CONTINUED THREAT THAT ANY
THUNDERSTORM COULD BECOME STRONG WITH GUSTY WINDS AND HAIL THROUGH
THE AFTERNOON AND EARLY EVENING HOURS.
HEAT...
BEHIND THIS WARM FRONT UNSEASONABLY WARM TEMPERATURES WILL BE
FOUND AS THE RECENT HEAT ACROSS THE PLAINS SLIDES NORTHEASTWARD. THE
CENTER OF A 592 DM 500 HPA RIDGE WILL REMAIN WELL TO OUR SOUTH OVER
THE SOUTHEASTERN STATES...BUT ITS AXIS WILL CROSS THE EASTERN GREAT
LAKES REGION TODAY. AT 850 HPA TEMPERATURES WILL RISE TO 20 TO AS
MUCH AS 22C WHICH WOULD FACTOR AT 2 SD ABOVE NORMAL. THESE
TEMPERATURES ALOFT WILL TRANSLATE TO AFTERNOON HIGHS WELL IN TO THE
80S...WITH THE VALLEYS WARMER INCLUDING THE GENESEE VALLEY WHERE LOW
90S ARE LIKELY. A SOUTHWEST WIND OFF A LOW 70S LAKE WILL KEEP AREAS
AROUND BUFFALO AND JUST NORTH OF WATERTOWN A FEW DEGREES COOLER. FOR
MORE DETAILS ON RECORD TEMPERATURES TODAY AND WEDNESDAY PLEASE
REFERENCE THE CLIMATE SECTION BELOW. WITH THE WARMEST DAYS THIS YEAR
IN THE LOW TO MID 90S ACROSS THE REGION...TODAY WILL BE ONE OF THE
WARMEST DAYS THIS YEAR...AND POSSIBLY A FEW LOCATIONS IN THE GENESEE
VALLEY COULD HAVE A SHOT OF TUESDAY BEING THE WARMEST DAY OF THE
YEAR. WHEN FACTORING IN THE HUMIDITY THIS AFTERNOON`S APPARENT
TEMPERATURES WILL SOAR WELL INTO THE 90S ACROSS THE LOWER ELEVATIONS
OF WESTERN NEW YORK...AND POSSIBLY UPPER 90S WITHIN THE GENESEE
VALLEY AND NORTHERN FINGER LAKES REGION.
WINDS...
TODAY WILL ALSO BE QUITE BREEZY AS THE PRESSURE GRADIENT
INCREASES BETWEEN HIGH PRESSURE ARCHED ALONG THE EAST COAST AND THE
LOW PRESSURE/COLD FRONT WHICH WILL BE ADVANCING INTO THE SOUTHERN
ONTARIO PENINSULA TODAY. ALSO AIDING IN THE STRONGER WINDS TODAY
WILL BE DAYTIME MIXING. THOUGH RECENT RUNS OF THE 00Z NAM AND GFS
SUGGEST SLIGHTLY LESS OF A LLJ THAN PRIOR RUNS TODAY SHOULD STILL BE
ON THE WINDY SIDE ESPECIALLY DOWNWIND OF THE LAKES. SOUTHWEST WINDS
WILL AID IN WARMING THE VALLEYS OF THE CWA...WHILE ALSO GUSTING
DOWNWIND OF LAKE ERIE INTO THE 35 TO 40 MPH RANGE.
THESE SOUTHWEST WINDS BEHIND A WARM FRONT THAT WILL STALL NEAR THE
U.S. AND CANADIAN BORDER WILL ALSO BRING INCREASING MOISTURE AND
HUMIDITY INTO THE REGION. DEWPOINTS WILL RISE INTO THE MID AND UPPER
60S...WHICH COMBINED WITH THE VERY WARM TEMPERATURES WILL BRING
IMPRESSIVE SBCAPE VALUES TO OUR REGION. SBCAPES RANGING FROM 2000 TO
JUST OVER 2500 J/KG ARE POSSIBLE BEHIND THIS WARM FRONT...HOWEVER
WITH NO TRIGGER TO INITIATE CONVECTION (UPPER LEVEL SHORTWAVE RIDING
TO OUR NORTH ALONG THE CANADIAN BORDER) AS WELL AS WARMING IN THE
MID LEVELS...WILL LEAVE AREAS SOUTH OF THE WARM FRONT DRY AFTER THE
SCATTERED EARLY MORNING ACTIVITY. EXPECT CLOUDS TO DIMINISH THROUGH
THE DAY TIME SOUTH OF LAKE ONTARIO.
TUESDAY NIGHT WILL CONTINUE TO BE MUGGY AND LARGELY BE QUIET SOUTH
OF LAKE ONTARIO...WHILE THE STALLING WARM FRONT WILL CONTINUE THE
POTENTIAL FOR A FEW SHOWERS AND THUNDERSTORMS OVERNIGHT ACROSS THE
NORTH COUNTRY. CENTERED WITHIN THE WARM SECTOR OF THIS STORM SYSTEM
THIS NIGHT WILL BE UNSEASONABLY WARM WITH TEMPERATURES LIKELY TO NOT
DROP OUT OF THE LOW 70S ACROSS MUCH OF THE CWA. INLAND AND ACROSS
THE HILL TOPS WILL BE SLIGHTLY COOLER AND THESE AREAS WILL BE THE
LOCATIONS THAT WILL DROP INTO THE UPPER 60S.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
ANOTHER UNSEASONABLY HOT AND HUMID DAY IN STORE FOR WESTERN AND
NORTH CENTRAL NEW YORK WEDNESDAY...AS THERMAL BUBBLE REMAINS ACROSS
THE REGION AHEAD OF SLOW MOVING COLD FRONT. RIBBON OF 850 MB
TEMPERATURES AROUND 20C SHOULD ONCE AGAIN SUPPORT AFTERNOON
TEMPERATURES WELL INTO THE 80S TO PERHAPS THE LOWER 90S IN THE
VALLEYS AND ALONG THE LAKE PLAINS. SURFACE DEWPOINTS IN THE MID 60S
WILL SEND APPARENT TEMPERATURES INTO THE MID 90S. CONVECTIVE CHANCES
WEDNESDAY LOOK PROBLEMATIC WITH LITTLE FORCING FORECAST ACROSS THE
REGION WITH THE COLD FRONT STILL OFF TO OUR NORTHWEST. ALTHOUGH THE
PRE-FRONTAL ENVIRONMENT WILL BECOME INCREASINGLY UNSTABLE...IT LOOKS
TO BE LARGELY CAPPED WITH A WARM NOSE AROUND 800 MB STILL NOTED ON
MODEL SOUNDINGS. PRIMARY THREAT FOR CONVECTION WILL BE ALONG
LOCALIZED LAKE BREEZE BOUNDARIES INLAND FROM THE LAKES. IF
THUNDERSTORMS CAN DEVELOP...ISOLATED SEVERE STORMS ARE POSSIBLE WITH
DECENT SURFACE BASED CAPE PROFILES AND MAINTENANCE OF STRONG
KINEMATICS.
MORE INTERESTING SET UP DEVELOPING WEDNESDAY NIGHT AND THURSDAY AS
NEXT WAVE AND SHARPER TROUGHING ARRIVES...REINVIGORATING THE
APPROACHING COLD FRONT. THE RESULTING ENHANCEMENT OF MID AND
UPPER-LEVEL ASCENT FIELDS WILL MAKE THE LATE WEDNESDAY NIGHT AND
EARLY THURSDAY TIME FRAME THE PRIME PERIOD FOR SHOWER AND
THUNDERSTORM DEVELOPMENT WITHIN THE NARROW MID-LEVEL THETA-E RIBBON
ALONG THE FRONT. SHEAR PROFILES SUGGEST SOME POTENTIAL FOR DAMAGING
WIND GUSTS IF MORE ORGANIZED CONVECTION CAN DEVELOP.
THE FRONT IS EXPECTED TO BE THROUGH OUR AREA BY EARLY THURSDAY
AFTERNOON WITH NOTABLY DRIER AND COOLER CANADIAN AIR CLEARING OUT
OUR SKIES FROM THE NORTHWEST. WILL TAPER OFF THE POPS ACCORDINGLY
WITH ONLY SLGT CHC POPS REMAINING EAST OF ROCHESTER BY EVENING. IN
TERMS OF TEMPERATURES...WE SHOULD MAX OUT IN THE MID 70S EARLY IN
THE DAY WITH STEADY OR SLOWLY FALLING MERCURY READINGS ANTICIPATED
FOR THE AFTERNOON WHEN DEW POINTS WILL DROP OFF THROUGH THE 50S.
OUR ATTENTION WILL TURN FROM SYNOPTIC TO MESOSCALE THURSDAY NIGHT AS
SEASONABLY CHILLY AIR WILL POUR ACROSS THE LOWER LAKES IN ADVANCE OF
AN EXPANSIVE AREA OF HIGH PRESSURE OVER WESTERN ONTARIO. H85 TEMPS
ARE PROJECTED TO DROP TO ARND 4C BY DAYBREAK FRIDAY...AND WITH A
DEEP CYCLONIC NORTHWEST FLOW IN PLACE...THERE WILL CERTAINLY BE
ENOUGH LAKE INSTABILITY TO SUPPORT SOME LAKE CLOUDINESS...AND
POSSIBLY NUISANCE SHOWERS EAST/SOUTHEAST OF LK ONTARIO. LOW
TEMPERATURES WILL RANGE FROM THE LOWER 50S ACROSS THE LAKE PLAINS TO
THE MID 40S IN THE SRN TIER VALLEYS/EAST OF THE BLACK RIVER VALLEY.
THESE READINGS WILL BE AT LEAST 15 DEG F LOWER THEN PREVIOUS NIGHTS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
TEMPERATURES WILL AVERAGE NEAR TO BELOW NORMAL DURING THIS PERIOD AS
AN AMPLIFIED LONGWAVE PATTERN OVER THE LOWER 48 WILL BREAK DOWN...
LEAVING MORE OF A ZONAL FLOW ACROSS OUR REGION.
A VIGOROUS SHORTWAVE WILL DROP INTO THE BASE OF A LONGWAVE TROUGH
CENTERED OVER THE LOWER GREAT LAKES ON FRIDAY. THIS FEATURE WILL
COUPLE WITH STRONG COLD ADVECTION TO PRODUCE SOME SHOWERS SOUTH OF
LAKE ONTARIO DURING THE MIDDAY AND AFTERNOON...WHILE TEMPERATURES
WILL STRUGGLE TO REACH 60. THE STRONG MID LEVEL FEATURE WILL SWING
OFF ACROSS NEW ENGLAND FRIDAY NIGHT...WHILE STRONG RIDGING WILL
BUILD IN FROM THE UPPER GREAT LAKES. THIS WILL QUICKLY CLEAR OUT ANY
LEFTOVER SHOWER ACTIVITY...ALTHOUGH SOME NUISANCE LAKE DRIVEN
SHOWERS CANNOT BE RULED OUT WITHIN WEAK CYCLONIC FLOW BETWEEN ROC
AND SYR.
BOTH DAYS OF THE WEEKEND WILL THEN BE DOMINATED BY AN EXPANSIVE AREA
OF HIGH PRESSURE THAT WILL BE PARKED OVER THE GREAT LAKES REGION.
WHILE IT WILL BE SEASONABLY COOL ON SATURDAY WITH HIGHS CLOSE TO
60...WEAK WARM ADVECTION DURING THE SECOND HALF OF THE WEEKEND WILL
BOOST DAYTIME TEMPS BY SOME 10 DEGREES FOR SUNDAY. THIS WILL
TRANSLATE INTO READINGS THAT WILL BE RIGHT ON TARGET FOR NORMALS IN
MID SEPTEMBER...WHICH ARE WITHIN A FEW DEGREES OF 70.
CONFIDENCE IN THE FORECAST WILL DROP OFF SIGNIFICANTLY ON MONDAY...
AS THE DETERMINISTIC PACKAGES ARE AT ODDS OVER THE PASSAGE OF THE
NEXT FRONTAL SYSTEM. WILL CARRY SLGT CHC POPS FOR NOW WHILE LEAVING
TEMPS CLOSE TO THOSE FROM SUNDAY.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
AT 06Z VFR FLIGHT CONDITIONS WERE COMMON ACROSS THE REGION...WITH
MID LEVEL CLOUDS DIVING SOUTHEASTWARD. EXPECT SOME LOWERING TO MVFR
AND LOWER AS MOISTURE BUILDS AND SHOWERS AND THUNDERSTORMS INCREASE
IN COVERAGE AREA AND CROSS THE REGION.
THROUGH THE EARLY MORNING HOURS A STRONG WARM FRONT WILL CROSS THE
REGION WITH INCREASING COVERAGE OF SHOWERS ACROSS MUCH OF THE
AREA...ALONG WITH A FEW EMBEDDED THUNDERSTORMS. THUNDERSTORMS THIS
MORNING WILL BE MOST LIKELY ACROSS LAKE ONTARIO AND THE EASTERN LAKE
ONTARIO REGION AS AN UPSTREAM MCS CONTINUES TO NEAR THE REGION THIS
MORNING. THIS ACTIVITY WILL BRING BRIEF PERIODS OF MVFR/IFR
CONDITIONS IN ANY OF THE HEAVIER SHOWERS. THE SHOWERS AND ANY
THUNDER WILL END FROM SOUTHWEST TO NORTHEAST TUESDAY MORNING AS THE
WARM FRONT LIFTS NORTHEAST ACROSS THE AREA. ANY LINGERING MVFR/IFR
CONDITIONS ASSOCIATED WITH THE SHOWERS WILL ALSO END.
FOLLOWING THE WARM FRONT...SKIES WILL CLEAR AND WINDS WILL BECOME
RATHER STRONG WITH GUSTS OF AROUND 30 KNOTS LIKELY ACROSS WESTERN NY
FROM KBUF-KIAG-KROC...WITH 20-25 KNOTS ELSEWHERE.
SOME LOW LEVEL WIND SHEAR IS LIKELY TONIGHT AS THE WARM FRONT LIFTS
NORTHEASTWARD AND A 35-40 KNOT LOW LEVEL JET CROSSES THE AREA. WINDS
WILL STILL BE STRONG JUST OFF THE DECK ON TUESDAY...BUT AS SURFACE
WINDS INCREASE THIS WILL ALLEVIATE ANY SHEAR.
WINDS WILL DIMINISH SOME THIS EVENING AS THE LOW PRESSURE WEAKENS
SOME...AND THE PRESSURE GRADIENT RELAXES. THOUGH WE WILL LOSE THE
STRONG GUSTS AND STILL SOUTHWEST WIND AROUND 10 KNOTS AND OCCASIONAL
LIGHT GUSTS WILL BE COMMON.
OUTLOOK...
WEDNESDAY...VFR.
WEDNESDAY NIGHT AND THURSDAY...MAINLY VFR WITH SHOWERS LIKELY AND
A CHANCE OF THUNDERSTORMS ALONG WITH ASSOCIATED BRIEF MVFR/IFR.
FRIDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
SATURDAY...VFR.
&&
.MARINE...
SOUTHWEST WINDS WILL CONTINUE TO STRENGTHEN TODAY WITH SUSTAINED
WINDS AROUND 20 KNOTS ON LAKE ERIE...ACROSS THE NIAGARA RIVER AND
ACROSS THE WESTERN HALF OF LAKE ONTARIO. WILL CONTINUE THE SCA FOR
THESE AREAS TODAY...AS WELL AS THE EASTERN END OF LAKE ONTARIO
WHERE WINDS WILL AVERAGE 15 TO 20 KNOTS...AND WAVES NEAR 4 FOOT IN
THE NORTHEAST CORNER OF THE LAKE.
THESE WINDS SHOULD RELAX TUESDAY NIGHT AS THE LOW PRESSURE WEAKENS.
SHOWERS AND THUNDERSTORMS WILL BE A THREAT ONCE AGAIN WEDNESDAY
NIGHT INTO THURSDAY AHEAD OF A COLD FRONT THAT IS EXPECTED TO CROSS
THE LAKES LATER ON THURSDAY...BRINGING ANOTHER CHANCE OF SMALL CRAFT
ADVISORY LEVEL NORTHWESTERLY WINDS THURSDAY NIGHT AND FRIDAY.
&&
.CLIMATE...
TUESDAY AND WEDNESDAY A LATE SUMMER AIRMASS WILL SETTLE ACROSS
THE REGION WITH MANY AREAS WELL INTO THE 80S. BELOW ARE THE RECORD
HIGHS...AND RECORD WARM LOWS FOR OUR THREE CLIMATE SITES:
BUFFALO..
TUESDAY HIGH: 90 (1955) LOW: 75 (1983)
WEDNESDAY HIGH: 87 (1952) LOW: 72 (1931)
ROCHESTER..
TUESDAY HIGH: 94 (1897) LOW: 73 (1925)
WEDNESDAY HIGH: 94 (1931) LOW: 71 (1931)
WATERTOWN..
TUESDAY HIGH: 90 (1959) LOW: 70 (1962)
WEDNESDAY HIGH: 89 (1961) LOW: 70 (1961)
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 6 PM EDT THIS
EVENING FOR LEZ020-040-041.
SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 6 PM
EDT THIS EVENING FOR LOZ030.
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 8 PM EDT
THIS EVENING FOR LOZ042-043.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
LOZ045.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...THOMAS
SHORT TERM...RSH/TMA
LONG TERM...RSH
AVIATION...THOMAS
MARINE...THOMAS
CLIMATE...THOMAS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
403 AM EDT TUE SEP 10 2013
.SYNOPSIS...
THE NEXT COUPLE OF DAYS WILL FEATURE A BRIEF RETURN TO SUMMER
WEATHER BEFORE TEMPERATURES COOL BACK OFF TO MORE FALL-LIKE
LEVELS BY THE END OF THE WEEK AND INTO THE WEEKEND. THERE WILL
ALSO BE SEVERAL CHANCES FOR SHOWERS AND THUNDERSTORMS FROM LATE
TONIGHT THROUGH THURSDAY...SOME POTENTIALLY STRONG TO
SEVERE...ESPECIALLY LATE WEDNESDAY.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1258 AM EDT TUESDAY...ONLY MINOR ADJUSTMENTS MADE TO HOURLY
PARAMETERS FOR NEXT SEVERAL HOURS BASED ON LATEST OBSERVATIONAL
DATA AND NEAR TERM GUIDANCE. SHOWERS APPROACHING ST LWR VLY...AND
WILL CONTINUE TO MONITOR MCS OVER NORTHERN GRTLKS AS IT MOVES
SEWRD OVRNGHT.
PREVIOUS DISCUSSION...
MOSTLY MINOR TWEAKS MADE TO TEMPERATURES AND DEWPOINTS TO ACCOUNT
FOR LATEST SFC OBSERVATIONS. HOWEVER...AN ELEVATED MCS THAT IS NOW
EXITING LAKE SUPERIOR HAS RESULTED IN SOME MORE SIGNIFICANT
CHANGES TO POPS TOWARDS THE MORNING. THIS MCS HAS FORMED ON
NORTHERN EDGE OF INSTABILITY GRADIENT WHICH EXTENDS FROM THE
NORTHERN GREAT LAKES INTO SOUTHERN NY/PA. BASED ON CORFIDI VECTORS
BEING NORTHWEST AROUND 25-30 KTS EXPECT THIS MCS TO MOVE
SOUTHEASTWARD. LATEST HRRR AND RAP SIMULATED REFLECTIVITY PROGS
TAKE THE COMPLEX SOUTHEASTWARD ACROSS CENTRAL NEW YORK AROUND
SUNRISE. ITS EVOLUTION & TRACK WILL BE MONITORED THIS EVENING FOR
ANY SHIFT NORTHWARD. THOUGH THE ENTIRE NORTH COUNTRY WILL STAND TO
SEE SHOWERS/THUNDERSTORMS TOWARDS MORNING DUE TO THE STRONG WARM
ADVECTION & ISENTROPIC LIFT THAT WILL BE TAKING PLACE...I SUSPECT
THE BEST CHANCE AT THUNDERSTORMS WOULD BE FOR OUR SOUTHWESTERN CWA
AREAS /FROM AN OGDENSBURG-SARANAC LAKE-NEWCOMB LINE/. I HAVE
RAISED POPS ACCORDINGLY IN THE ADIRONDACKS AND SOUTHERN SAINT
LAWRENCE COUNTY TO BETTER REFLECT ABOVE REASONING. UNTIL
THEN...EXPECT SKIES TO CONTINUE TO FILL IN WITH TEMPERATURES
LEVELING OFF BEFORE RISING TOWARDS MORNING.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH THURSDAY/...
AS OF 325 PM EDT MONDAY...ACTIVE PERIOD OF WEATHER CONTINUES ON
TUESDAY...WITH THE POTENTIAL FOR A FEW STRONG-SEVERE
THUNDERSTORMS. MORNING SHOWERS/TSTORMS ASSOCIATED WITH STRONG WAA
AND CONVECTIVE COMPLEX SHOULD PUSH EAST OF THE REGION BY AROUND
15Z. AT THE SAME TIME THE SURFACE WARM FRONT WILL LIFT
NORTHEASTWARD AND BE DRAPED ACROSS THE AREA...LIKELY BISECTING
THE REGION. THE POSITION OF THIS WARM FRONT IS QUITE CRITICAL FOR
ANY SEVERE CONVECTIVE THREAT. ON SOUTH SIDE OF FRONT...EXPECTING
AT LEAST PARTIAL CLEARING LEADING TO DEVELOPMENT OF 1000-2000
J/KG OF MLCAPE BY LATE WEDNESDAY. THIS COMBINED WITH NEAR 50
KNOTS OF 0-6KM SHEAR AND 20-30 KNOTS OF 0-1KM SHEAR WILL LEAD TO
A CONDITIONAL THREAT OF SEVERE WEATHER. FORECAST SOUNDINGS FOR
TUESDAY AFTERNOON AT BTV/SLK/OGS SHOW CAPPING INVERSION LIMITING
OVERALL CONVECTIVE INITIATION. THUS WILL BE RELYING ON RELATIVELY
WEAK FORCING WITH POSSIBLE LEFTOVER BOUNDARIES FROM EARLY MORNING
CONVECTION OR THE WARM FRONT ITSELF. ON THE COOLER NORTH SIDE OF
BOUNDARY...ANY CONVECTIVE ACTIVITY IS LIKELY TO BE MORE ELEVATED
IN NATURE. THAT ALL BEING SAID...CURRENT THINKING IS THAT WARM
FRONT WILL BE SITUATED FROM THE SAINT LAWRENCE VALLEY ACROSS THE
ADIRONDACKS AND INTO THE CHAMPLAIN VALLEY...WITH THE BEST THREAT
OF ISOLATED SEVERE WEATHER FROM THE CHAMPLAIN VALLEY WESTWARD
ACROSS THE ADIRONDACKS AND INTO THE SAINT LAWRENCE VALLEY WHERE
CONVERGENCE MAY BE ENHANCED BY NORTHEAST FLOW DOWN THE NORTHERN
SAINT LAWRENCE VALLEY. WHILE COVERAGE IS EXPECTED TO BE
LIMITED...ANY THUNDERSTORM THAT MAY DEVELOP ALONG THE WARM FRONT
HAS THE POTENTIAL TO BECOME SEVERE WITH LARGE HAIL...DAMAGING
WINDS...HEAVY RAIN...AND A VERY LOW CHANCE OF A TORNADO.
OTHERWISE...HIGHS WILL ALSO BE VERY DEPENDENT ON POSITION OF WARM
FRONT WITH LOW 80S ON THE WARM SIDE AND LOW 70S ON THE COOL SIDE.
SYNOPTIC WIND GUSTS OUTSIDE OF THUNDERSTORM ACTIVITY WILL LIKELY
REACH 20-30 MPH ON WARM SIDE OF FRONT IN PRONOUNCED SOUTHWEST
FLOW.
THE FRONTAL BOUNDARY WILL REMAIN NEAR THE REGION INTO TUESDAY
NIGHT...WITH INSTABILITY REMAINING...ESPECIALLY ALOFT WITH
PRESENCE OF AN ELEVATED MIXED LAYER. THIS COMBINED WITH ABUNDANT
MOISTURE...AS NOTED BY 1.5-2" PRECIPITABLE WATER VALUES...WILL
KEEP THE CHANCE OF SHOWERS/THUNDERSTORMS AROUND THROUGH THE
NIGHT. TEMPERATURES WILL HAVE TROUBLE FALLING...SO LOOKING AT A
LOT OF UPPER 60S AND LOWER 70S.
POTENTIALLY MORE WIDESPREAD STRONG-SEVERE THUNDERSTORMS ARE
POSSIBLE LATER WEDNESDAY. THE WEAK BOUNDARY WILL REMAIN NEAR THE
REGION...AND FORCING WILL BE ENHANCED BY THE APPROACH OF AN UPPER
TROUGH FROM THE WEST...ESPECIALLY LATER WEDNESDAY AND INTO
WEDNESDAY NIGHT. THE AREA IS EXPECTED TO BE LARGELY INTO THE WARM
SECTOR WITH WIDESPREAD 80S FOR HIGHS...POSSIBLY EVEN A SPOT 90F
IN THE CHAMPLAIN VALLEY. THIS COUPLED WITH DEW POINTS IN THE
UPPER 60S TO NEAR 70 WILL PRODUCE A VERY UNSTABLE AIRMASS WITH
UPWARDS OF 2000 J/KG OF MLCAPE. SHEAR PROFILES STILL LOOK VERY
FAVORABLE FOR STRONG-SEVERE THUNDERSTORM DEVELOPMENT WITH 40-50
KNOTS OF 0-6KM SHEAR ANTICIPATED. 0-1KM SHEAR VALUES ARE
SIGNIFICANTLY LOWER THAN TUESDAY...WITH MAIN POTENTIAL IMPACTS
BEING LARGE HAIL AND DAMAGING WINDS. GREATEST THREAT OF SEVERE
THUNDERSTORMS SHOULD BE 21Z-03Z. GIVEN HIGH MOISTURE
CONTENT...HEAVY RAIN AND MINOR FLOODING WILL BE POSSIBLE IN ANY
THUNDERSTORMS.
COLD FRONT NEARS THE REGION LATER WEDNESDAY NIGHT WITH POTENTIAL
FOR ELEVATED CONVECTIVE ACTIVITY CONTINUING. STRONG SOUTHWEST FLOW
IS ALSO MAINTAINED SO LOWS IN THE UPPER 60S/LOWER 70S LOOK GOOD
AGAIN.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 403 AM EDT TUESDAY...MDLS BRING SLOW MVG FRNTL BOUNDARY ACROSS
THE REGION THURSDAY NIGHT INTO FRIDAY...FOLLOWED BY UPPER LEVEL
TROUGH INTO SATURDAY MORNING. THIS WILL BE FOLLOWED UP WITH SFC
RIDGE BUILDING EAST FROM THE MIDWEST REGION LATER SATURDAY THRU
THE REST OF THE UPCOMING WEEKEND INTO THE BEGINNING OF NEXT WEEK.
WK FRNT IS EXPECTED TO PUSH SOUTH OUT OF QUEBEC MONDAY FOLLOWED BY
HIGH PRESSURE AGAIN GOING INTO MIDWEEK.
THE FRNTL PASSAGE IN THE BEGINNING PORTION OF THE EXTENDED WILL BE
MAIN WX FEATURE. HIGHEST POPS WILL OCCUR DURING THE OVERNGT HRS
THURSDAY INTO FRIDAY MORNING. -RW(W/ SL CHANCE FOR -TRW THRU 06Z
FRI) WILL TAPER FRIDAY MORNING AS SFC RIDGE/DRIER AIR WORKS INTO SE
ONTARIO. WILL CARRY LIKELY POPS FOR MAINLY E VT/CWA AND TAPER TO
CHANCE OF -RW BFR ENDING EARLY SAT MORNING. SFC WAVE ALONG FRNT WILL
ENHANCE PRECIP LATE BFR ENDING. POSSIBLE FOR CUTOFF UPPER LOW
FORMING IN BASE OF TROUGH BEHIND FRNT. GFS LIGHTER ON RAIN VERSUS
ECMWF...SO WILL KEEP AT SL CHANCE FOR SAT MORNING DUE TO UNCERTAINTY
AND MDL CONSISTENCY. QPF AMTS WILL RANGE FROM 0.10" TO NEAR LOCALLY
0.20" AMTS ESPECIALLY IN E VT.
LOW LEVEL COLDER AIR ON NORTHERLY FLOW AHEAD OF APPROACHING SFC
RIDGE WILL SET UP CWA FOR BLW NORMAL TEMPS FOR THE REMAINDER OF THE
WEEKEND INTO NEXT WEEK. 850/925 TEMPS WILL RANGE FROM 0C TO +4/5C.
THE ARRIVAL OF COLDER AIR AT 850 WILL NOT COINCIDE WITH FRNTL PRECIP
BUT COULD BRING SOME PATCHY FROST OVER WEEKEND AT SPOTS IN HIR ELEV
OF DACKS/NC NE VT. OVERALL HIGHS WILL BE IN THE 60S WITH LOWS IN THE
30S TO MID40S WITH SOME NEAR 50F TOWARDS END OF EXTENDED MONDAY
NIGHT AS BRIEF SSW FLOW SETS UP ALONG FRNT.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
THROUGH 06Z WEDNESDAY...PERIODS OF VFR/MVFR CONDITIONS THRU THE
FORECAST PERIOD AS WARM FRONT MOVES ACROSS THE AREA. CEILINGS WILL
RANGE FROM BKN015-020 UP TO BKN050-100 IN VFR SKY COND. LIGHT
RAIN/FG WILL BRING VSBY DOWN TO 4-6SM AT TIMES FOR MPV/SLK/MSS AND
NO RESTRICTIONS FOR OTHER 3 SITES DUE TO SOUTHERLY WINDS. WINDS
WILL RANGE FROM SE TO SW 5-15KTS W/ GUSTS 20-25KTS AT TIMES
ESPECIALLY IN THE CVLY. SOME TRW COULD DEVELOP LATER TODAY AS FRNT
PUSHES THRU AREA.
OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...
PRIMARILY VFR...THOUGH PERIODS OF IFR/MVFR VSBYS WITH SCATTERED
SHOWERS AND THUNDERSTORMS AS WARM FRONT MOVES THROUGH REGION
TUESDAY FOLLOWED BY COLD FRONTAL PASSAGE THURSDAY. A FEW OF THE
STORMS MAY BE STRONG TO LOCALLY SEVERE TUESDAY EVENING ALONG THE
INTL BORDER...AND ACROSS THE ENTIRE FCST AREA WEDNESDAY AFTERNOON
AND EVENING. ANY STORMS THAT DO BECOME SEVERE MAY CONTAIN STRONG
TURBULENCE...LARGE HAIL AND STRONG SFC WINDS. THE UPPER LEVEL
TROUGH ASSOCIATED WITH THESE FRONTS WILL MOVE THROUGH
FRIDAY...KEEPING A THREAT OF SHOWERS OVER THE NORTH COUNTRY
THROUGH LATE FRIDAY. SATURDAY HIGH PRESSURE WILL BUILD IN AT THE
SFC.
&&
.EQUIPMENT...
AS OF 719 PM EDT SATURDAY...NOAA WEATHER RADIO STATION WXM 44,
BROADCASTING FROM THE TOP OF MOUNT ASCUTNEY VERMONT...REMAINS OFF
THE AIR DUE TO A DAMAGED ANTENNA. REPLACEMENT PARTS HAVE BEEN
ORDERED AND THE REPAIR WORK HAS NOW BEEN SCHEDULED FOR SEPTEMBER
17-20.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MUCCILLI
NEAR TERM...LOCONTO/MUCCILLI
SHORT TERM...MUCCILLI
LONG TERM...JN
AVIATION...JMG/JN
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BUFFALO NY
149 AM EDT TUE SEP 10 2013
.SYNOPSIS...
A WARM FRONT LIFTING ACROSS THE LOWER GREAT LAKES TONIGHT WILL BRING
A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS LATER TONIGHT THROUGH
EARLY TUESDAY ACROSS MUCH OF THE REGION. THIS WARM FRONT WILL
USHER IN UNSEASONABLY HOT AND MUGGY WEATHER TUESDAY AND
WEDNESDAY. EXPECT SHOWERS AND THUNDERSTORMS TO BREAK OUT WEDNESDAY
NIGHT AND THURSDAY AHEAD OF A COLD FRONT THAT WILL BRING A RETURN
TO MUCH COOLER WEATHER BY THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
RADAR IMAGERY SHOWING AN AREA OF SHOWERS SLOWLY INCREASING OVER
SOUTHERN ONTARIO. EXPECT THIS AREA OF SHOWERS TO CONTINUE TO SLOWLY
INCREASE IN COVERAGE AND INTENSITY OVER THE NEXT FEW HOURS AS WARM
ADVECTION INCREASES.
LATER TONIGHT OUR ATTENTION TURNS TO RAIN POTENTIAL ACROSS A BROADER
AREA. STRONG WARM ADVECTION WILL DEVELOP OVERNIGHT AS A WARM FRONTAL
ZONE OVER THE CENTRAL GREAT LAKES MOVES EAST. THE WARM ADVECTION AND
ISENTROPIC UPGLIDE WILL BE SUPPORTED BY A 35-40 KNOT LOW LEVEL
JET...WHICH WILL AID IN LIFT ACROSS THE WARM FRONTAL BOUNDARY AND
ALSO INCREASE MOISTURE CONVERGENCE OVERNIGHT. MESOSCALE MODEL
GUIDANCE IS TRENDING MORE AGGRESSIVE IN DEVELOPING SHOWERS AND A FEW
THUNDERSTORMS ALONG THE ADVANCING WARM FRONT OVERNIGHT. THE PAST FEW
RUNS OF THE HIGH RESOLUTION RAPID REFRESH /HRRR/ BRINGS AN ORGANIZED
AREA OF CONVECTION ACROSS LAKE ONTARIO AND INTO WESTERN AND CENTRAL
NY AROUND 10Z. THE SPC STORM SCALE ENSEMBLE OF OPPORTUNITY IS ALSO
WETTER AND FARTHER SOUTH THAN OPERATIONAL MODEL GUIDANCE...AND
BRINGS MEASURABLE RAIN INTO MUCH OF THE AREA IN THE 06Z-12Z TIME
FRAME.
THE HRRR GUIDANCE SEEMS TOO SLOW GIVEN UPSTREAM RADAR TRENDS...WITH
SHOWERS ALREADY SPREADING ACROSS THE THUMB OF MICHIGAN AT 2330Z.
TYPICALLY WITH AVERAGE STORM MOTION SHOWERS CAN MAKE IT FROM THE
THUMB TO WESTERN NY IN ABOUT 6 HOURS. ALSO OF NOTE...THE LAST FEW
VISIBLE SATELLITE SHOTS OF THE DAY SHOWED A NICE FIELD OF TEXTURED
CLOUDS ACROSS NORTHERN LOWER MICHIGAN...MARKING AN AREA OF MID LEVEL
ELEVATED INSTABILITY. GIVEN THE UPSTREAM RADAR AND SATELLITE
TRENDS...AM INCLINED TO BUY INTO THE MORE AGGRESSIVE MESOSCALE MODEL
SOLUTIONS FOR LATER TONIGHT.
THE MATURING MCS OVER EASTERN LAKE SUPERIOR WILL ALSO NEED TO BE
WATCHED FOR VERY LATE TONIGHT AND EARLY TUESDAY. IF THIS FEATURE
SURVIVES OVERNIGHT...IT SHOULD START TO TURN RIGHT SOME ALONG THE
INSTABILITY GRADIENT AND ALSO DUE TO THE INCREASING LOW LEVEL JET
AND ITS INFLUENCE ON CORFIDI VECTORS.
WITH THE ABOVE IN MIND...HAVE INCREASED POPS TO LIKELY AFTER
MIDNIGHT AND SPREAD POPS MUCH FARTHER TO THE SOUTH AND WEST...WITH
THE MOST LIKELY TRACK OF SHOWERS LATE TONIGHT FROM THE NIAGARA
FRONTIER INTO CENTRAL NY AND THE FINGER LAKES. EXPECT A FEW EMBEDDED
THUNDERSTORMS AS WELL WITH LOCALLY HEAVY DOWNPOURS IF THIS
MATERIALIZES.
ANY ONGOING SHOWERS AND THUNDERSTORMS SHOULD LIFT OFF TO OUR
NORTHEAST TUESDAY MORNING...LEAVING WESTERN AND NORTH-CENTRAL NEW
YORK HOT AND RAIN-FREE FOR THE REST OF THE DAY. RAIN-FREE..BUT NOT
DRY HOWEVER AS DEWPOINTS WELL SOAR INTO THE MID TO UPPER 60S. WITH
850MB TEMPS CLIMBING POTENTIALLY AS HIGH AS +22C AND SOUTHERLY
WINDS...LOOK FOR READINGS TO SOAR INTO THE 90S ACROSS MANY
AREAS...POSSIBLY EVEN FLIRTING WITH RECORD HIGHS AT ROCHESTER.
BUFFALO SHOULD BE SPARED THE HOTTEST TEMPERATURES THANKS TO BRISK
ONSHORE SOUTHWESTERLY FLOW...AS WILL THE NORTH COUNTRY...HOWEVER IT
WILL BE UNUSUALLY HOT ELSEWHERE.
REGARDING WINDS FOR TOMORROW...THE CLEARING SKIES AND SOARING
TEMPERATURES WILL ALLOW FOR PLENTY OF MIXING OF THE BOUNDARY
LAYER...AND THIS WILL LEAD TO GUSTY WINDS...PARTICULARLY ACROSS THE
NIAGARA FRONTIER AND ALONG LAKE ERIE WHERE THE STRONGEST WINDS ALOFT
WILL BE. NAM MODEL PROFILES INDICATE THAT GUSTS COULD APPROACH
ADVISORY LEVELS...HOWEVER THEY HAVE CONSTANTLY BEEN THE OUTLIERS ON
THE STRONG SIDE AND FOR NOW WILL SIDE WITH THE WEAKER GFS/ECMWF/GEM
AND MAINTAIN CONTINUITY WITH GUSTS TO AROUND 35 KNOTS.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
IT WILL BE QUITE WARM TO START THIS PERIOD AS A LOW AMPLITUDE SPLIT
FLOW OVER THE LOWER 48 WILL INCLUDE AN ANOMALOUSLY WARM RIDGE THAT
WILL BE PARKED OVER THE SOUTHEASTERN STATES. THIS RIDGE WILL FEATURE
H925 TEMPS OF AT LEAST 20C (+3 STD) FOR THE SECOND DAY IN A ROW FOR
OUR FORECAST AREA...BUT A CHANGE TO MUCH COOLER WEATHER WILL BE ON
THE HORIZON. AS HEAD TOWARDS THE END OF THE WEEK...SIGNIFICANT
AMPLIFICATION WILL TAKE PLACE WITHIN A PHASED UPPER LEVEL FLOW. THIS
WILL PLACE A DEEP TROUGH OVER THE LOWER GREAT LAKES WHICH WILL
RESULT IN BELOW NORMAL TEMPS FOR THE END OF THE WEEK. MORE ON THIS
IN THE LONG TERM PORTION OF THIS DISCUSSION.
ALL OF WESTERN AND NORTH CENTRAL NEW YORK WILL BE POSITIONED DEEP
WITHIN A WARM SECTOR TUESDAY NIGHT...AS A STALLED WARM FRONTAL WILL
BE FOUND IN THE VCNTY OF THE OTTAWA VALLEY. WHILE THERE COULD BE A
SHOWER OR THUNDERSTORM OVER THE NORTH COUNTRY/THOUSAND ISLANDS
REGION EARLY THURSDAY NIGHT...DRY BUT SULTRY CONDITIONS WILL PREVAIL
OVER THE REGION. AFTER AN AFTERNOON OF NEAR RECORD HEAT...H85 TEMPS
OF +22C AND STRONG SOUTHERLY FLOW WILL EASILY HOLD OUR OVERNIGHT
TEMPS SOME 15 TO 20 DEG F ABV NORMAL VALUES WITH MINS NOT FAR 70.
THIS WILL BE FOLLOWED BY ANOTHER HOT AND HUMID DAY ON WEDNESDAY AS A
BROAD SOUTHWESTERLY FLOW WILL KEEP UNSEASONABLY WARM AIR IN PLACE.
H85 TEMPS NEAR 20C WILL ONCE AGAIN SUPPORT AFTERNOON TEMPS IN THE
UPPER 80S TO LOWER 90S IN THE VALLEYS AND LAKE PLAINS...SO WILL ADD
A FEW DEGREES TO CONTINUITY. THIS HEAT WILL COMBINE WITH DEW POINTS
IN THE UPPER 60S TO PROVIDE PLENTY OF FUEL FOR AFTERNOON CONVECTION.
SBCAPES ARE FORECAST TO REACH 1500-2000 J/KG AWAY FROM THE LAKES...
AND WHILE AIRMASSES LIKE THIS ARE TYPICALLY CAPPED...LAPSE RATES OF
8 TO >10 DEG C/KM ARE FORECAST UP THROUGH H6. THIS LARGE AMOUNT OF
INSTABILITY WILL NEED A TRIGGER TO BE REALIZED THOUGH...AND WITHOUT
ANY SYNOPTIC FORCING TO WORK WITH...THE `LIFTING` WILL HAVE TO COME
FROM LOCALIZED OROGRAPHICS OR LAKE BREEZE BOUNDARIES. THIS SHOULD
LIMIT CONVECTION TO AREAS WELL AWAY FROM THE LAKES...WITH THE LOWEST
POPS FOUND OVER THE IAG FRONTIER WHERE THE STABILIZING EFFECTS OF A
SOUTHWEST FLOW WILL BE IN PLACE. WILL THUS REMOVE MENTION OF STORMS
FOR THE IAG FRONTIER FROM CONTINUITY WHILE ADDING A LITTLE ENHANCED
WORDING FOR GUSTY WINDS TO THE STORMS OVER THE SRN TIER AND FINGER
LAKES.
A ROBUST SHORTWAVE OVER WESTERN ONTARIO WEDNESDAY EVENING WILL PUSH
A STRENGTHENING COLD FRONT ACROSS LOWER MICHIGAN AND SOUTHERN
ONTARIO DURING THE COURSE OF THE OVERNIGHT. WHILE THE FIRST OF
WEDNESDAY NIGHT SHOULD BE WARM AND RAIN FREE OVER MUCH OF OUR
REGION...SHOWERS AND THUNDERSTORMS WILL LIKELY DEVELOP OUT OF THE
FRONT BY DAYBREAK THURSDAY WHEN THE BOUNDARY IS FORECAST TO BE OVER
THE LOWER GREAT LAKES.
THE FRONT IS EXPECTED TO BE THROUGH OUR AREA BY EARLY THURSDAY
AFTERNOON WITH NOTABLY DRIER AND COOLER CANADIAN AIR CLEARING OUT
OUR SKIES FROM THE NORTHWEST. WILL TAPER OFF THE POPS ACCORDINGLY
WITH ONLY SLGT CHC POPS REMAINING EAST OF ROCHESTER BY EVENING. IN
TERMS OF TEMPERATURES...WE SHOULD MAX OUT IN THE MID 70S EARLY IN
THE DAY WITH STEADY OR SLOWLY FALLING MERCURY READINGS ANTICIPATED
FOR THE AFTERNOON WHEN DEW POINTS WILL DROP OFF THROUGH THE 50S.
OUR ATTENTION WILL TURN FROM SYNOPTIC TO MESOSCALE THURSDAY NIGHT AS
SEASONABLY CHILLY AIR WILL POUR ACROSS THE LOWER LAKES IN ADVANCE OF
AN EXPANSIVE AREA OF HIGH PRESSURE OVER WESTERN ONTARIO. H85 TEMPS
ARE PROJECTED TO DROP TO ARND 4C BY DAYBREAK FRIDAY...AND WITH A
DEEP CYCLONIC NORTHWEST FLOW IN PLACE...THERE WILL CERTAINLY BE
ENOUGH LAKE INSTABILITY TO SUPPORT SOME LAKE CLOUDINESS...AND
POSSIBLY NUISANCE SHOWERS EAST/SOUTHEAST OF LK ONTARIO. LOW
TEMPERATURES WILL RANGE FROM THE LOWER 50S ACROSS THE LAKE PLAINS TO
THE MID 40S IN THE SRN TIER VALLEYS/EAST OF THE BLACK RIVER VALLEY.
THESE READINGS WILL BE AT LEAST 15 DEG F LOWER THEN PREVIOUS NIGHTS.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
TEMPERATURES WILL AVERAGE NEAR TO BELOW NORMAL DURING THIS PERIOD AS
AN AMPLIFIED LONGWAVE PATTERN OVER THE LOWER 48 WILL BREAK DOWN...
LEAVING MORE OF A ZONAL FLOW ACROSS OUR REGION.
A VIGOROUS SHORTWAVE WILL DROP INTO THE BASE OF A LONGWAVE TROUGH
CENTERED OVER THE LOWER GREAT LAKES ON FRIDAY. THIS FEATURE WILL
COUPLE WITH STRONG COLD ADVECTION TO PRODUCE SOME SHOWERS SOUTH OF
LAKE ONTARIO DURING THE MIDDAY AND AFTERNOON...WHILE TEMPERATURES
WILL STRUGGLE TO REACH 60. THE STRONG MID LEVEL FEATURE WILL SWING
OFF ACROSS NEW ENGLAND FRIDAY NIGHT...WHILE STRONG RIDGING WILL
BUILD IN FROM THE UPPER GREAT LAKES. THIS WILL QUICKLY CLEAR OUT ANY
LEFTOVER SHOWER ACTIVITY...ALTHOUGH SOME NUISANCE LAKE DRIVEN
SHOWERS CANNOT BE RULED OUT WITHIN WEAK CYCLONIC FLOW BETWEEN ROC
AND SYR.
BOTH DAYS OF THE WEEKEND WILL THEN BE DOMINATED BY AN EXPANSIVE AREA
OF HIGH PRESSURE THAT WILL BE PARKED OVER THE GREAT LAKES REGION.
WHILE IT WILL BE SEASONABLY COOL ON SATURDAY WITH HIGHS CLOSE TO
60...WEAK WARM ADVECTION DURING THE SECOND HALF OF THE WEEKEND WILL
BOOST DAYTIME TEMPS BY SOME 10 DEGREES FOR SUNDAY. THIS WILL
TRANSLATE INTO READINGS THAT WILL BE RIGHT ON TARGET FOR NORMALS IN
MID SEPTEMBER...WHICH ARE WITHIN A FEW DEGREES OF 70.
CONFIDENCE IN THE FORECAST WILL DROP OFF SIGNIFICANTLY ON MONDAY...
AS THE DETERMINISTIC PACKAGES ARE AT ODDS OVER THE PASSAGE OF THE
NEXT FRONTAL SYSTEM. WILL CARRY SLGT CHC POPS FOR NOW WHILE LEAVING
TEMPS CLOSE TO THOSE FROM SUNDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AT 06Z VFR FLIGHT CONDITIONS WERE COMMON ACROSS THE REGION...WITH
MID LEVEL CLOUDS DIVING SOUTHEASTWARD. EXPECT SOME LOWERING TO MVFR
AND LOWER AS MOISTURE BUILDS AND SHOWERS AND THUNDERSTORMS INCREASE
IN COVERAGE AREA AND CROSS THE REGION.
THROUGH THE EARLY MORNING HOURS A STRONG WARM FRONT WILL CROSS THE
REGION WITH INCREASING COVERAGE OF SHOWERS ACROSS MUCH OF THE
AREA...ALONG WITH A FEW EMBEDDED THUNDERSTORMS. THUNDERSTORMS THIS
MORNING WILL BE MOST LIKELY ACROSS LAKE ONTARIO AND THE EASTERN LAKE
ONTARIO REGION AS AN UPSTREAM MCS CONTINUES TO NEAR THE REGION THIS
MORNING. THIS ACTIVITY WILL BRING BRIEF PERIODS OF MVFR/IFR
CONDITIONS IN ANY OF THE HEAVIER SHOWERS. THE SHOWERS AND ANY
THUNDER WILL END FROM SOUTHWEST TO NORTHEAST TUESDAY MORNING AS THE
WARM FRONT LIFTS NORTHEAST ACROSS THE AREA. ANY LINGERING MVFR/IFR
CONDITIONS ASSOCIATED WITH THE SHOWERS WILL ALSO END.
FOLLOWING THE WARM FRONT...SKIES WILL CLEAR AND WINDS WILL BECOME
RATHER STRONG WITH GUSTS OF AROUND 30 KNOTS LIKELY ACROSS WESTERN NY
FROM KBUF-KIAG-KROC...WITH 20-25 KNOTS ELSEWHERE.
SOME LOW LEVEL WIND SHEAR IS LIKELY TONIGHT AS THE WARM FRONT LIFTS
NORTHEASTWARD AND A 35-40 KNOT LOW LEVEL JET CROSSES THE AREA. WINDS
WILL STILL BE STRONG JUST OFF THE DECK ON TUESDAY...BUT AS SURFACE
WINDS INCREASE THIS WILL ALLEVIATE ANY SHEAR.
WINDS WILL DIMINISH SOME THIS EVENING AS THE LOW PRESSURE WEAKENS
SOME...AND THE PRESSURE GRADIENT RELAXES. THOUGH WE WILL LOSE THE
STRONG GUSTS AND STILL SOUTHWEST WIND AROUND 10 KNOTS AND OCCASIONAL
LIGHT GUSTS WILL BE COMMON.
OUTLOOK...
TUESDAY NIGHT AND WEDNESDAY...VFR.
WEDNESDAY NIGHT AND THURSDAY...MAINLY VFR WITH SHOWERS LIKELY AND A
CHANCE OF THUNDERSTORMS ALONG WITH ASSOCIATED BRIEF MVFR/IFR.
FRIDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
SATURDAY...VFR.
&&
.MARINE...
RELATIVELY LIGHT WINDS ON THE LAKES THIS EVENING WILL GRADUALLY
STRENGTHEN OVERNIGHT AS A WARM FRONT LIFTS NORTH ACROSS THE REGION.
THIS FRONT WILL BRING A CHANCE OF SHOWERS AND THUNDERSTORMS...MAINLY
TO THE WATERS OF LAKE ONTARIO...LATER TONIGHT AND INTO TUESDAY
MORNING. EXPECT SOUTHWESTERLY FLOW TO FRESHEN ON TUESDAY AS AN AREA
OF LOW PRESSURE SKIRTS BY TO THE NORTH OF THE LAKES WITH WINDS
STRENGTHENING ENOUGH TO WARRANT SMALL CRAFT ADVISORIES FOR THE
NEARSHORE WATERS OF EASTERN LAKE ERIE/WESTERN LAKE ONTARIO ON
TUESDAY. WINDS WILL ALSO INCREASE TO SMALL CRAFT ADVISORY LEVELS AT
THE NORTHEAST END OF LAKE ONTARIO. THESE WINDS SHOULD RELAX TUESDAY
NIGHT AS THE LOW WEAKENS.
SHOWERS AND THUNDERSTORMS WILL BE A THREAT ONCE AGAIN WEDNESDAY
NIGHT INTO THURSDAY AHEAD OF A COLD FRONT THAT IS EXPECTED TO CROSS
THE LAKES LATER ON THURSDAY...BRINGING ANOTHER CHANCE OF SMALL CRAFT
ADVISORY LEVEL NORTHWESTERLY WINDS.
&&
.CLIMATE...
TUESDAY AND WEDNESDAY A LATE SUMMER AIRMASS WILL SETTLE ACROSS
THE REGION WITH MANY AREAS WELL INTO THE 80S. BELOW ARE THE RECORD
HIGHS...AND RECORD WARM LOWS FOR OUR THREE CLIMATE SITES:
BUFFALO..
TUESDAY HIGH: 90 (1955) LOW: 75 (1983)
WEDNESDAY HIGH: 87 (1952) LOW: 72 (1931)
ROCHESTER..
TUESDAY HIGH: 94 (1897) LOW: 73 (1925)
WEDNESDAY HIGH: 94 (1931) LOW: 71 (1931)
WATERTOWN..
TUESDAY HIGH: 90 (1959) LOW: 70 (1962)
WEDNESDAY HIGH: 89 (1961) LOW: 70 (1961)
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 6 PM EDT THIS
EVENING FOR LEZ020-040-041.
SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 6 PM
EDT THIS EVENING FOR LOZ030.
SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 8 PM EDT
THIS EVENING FOR LOZ042-043.
SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM EDT
THIS EVENING FOR LOZ045.
&&
$$
SYNOPSIS...HITCHCOCK/WOOD
NEAR TERM...HITCHCOCK/WOOD
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...THOMAS
MARINE...WOOD
CLIMATE...THOMAS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
102 AM EDT TUE SEP 10 2013
.SYNOPSIS...
THE NEXT COUPLE OF DAYS WILL FEATURE A BRIEF RETURN TO SUMMER
WEATHER BEFORE TEMPERATURES COOL BACK OFF TO MORE FALL-LIKE
LEVELS BY THE END OF THE WEEK AND INTO THE WEEKEND. THERE WILL
ALSO BE SEVERAL CHANCES FOR SHOWERS AND THUNDERSTORMS FROM LATE
TONIGHT THROUGH THURSDAY...SOME POTENTIALLY STRONG TO
SEVERE...ESPECIALLY LATE WEDNESDAY.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1258 AM EDT TUESDAY...ONLY MINOR ADJUSTMENTS MADE TO HOURLY
PARAMETERS FOR NEXT SEVERAL HOURS BASED ON LATEST OBSERVATIONAL
DATA AND NEAR TERM GUIDANCE. SHOWERS APPROACHING ST LWR VLY...AND
WILL CONTINUE TO MONITOR MCS OVER NORTHERN GRTLKS AS IT MOVES
SEWRD OVRNGHT.
PREVIOUS DISCUSSION...
MOSTLY MINOR TWEAKS MADE TO TEMPERATURES AND DEWPOINTS TO ACCOUNT
FOR LATEST SFC OBSERVATIONS. HOWEVER...AN ELEVATED MCS THAT IS NOW
EXITING LAKE SUPERIOR HAS RESULTED IN SOME MORE SIGNIFICANT
CHANGES TO POPS TOWARDS THE MORNING. THIS MCS HAS FORMED ON
NORTHERN EDGE OF INSTABILITY GRADIENT WHICH EXTENDS FROM THE
NORTHERN GREAT LAKES INTO SOUTHERN NY/PA. BASED ON CORFIDI VECTORS
BEING NORTHWEST AROUND 25-30 KTS EXPECT THIS MCS TO MOVE
SOUTHEASTWARD. LATEST HRRR AND RAP SIMULATED REFLECTIVITY PROGS
TAKE THE COMPLEX SOUTHEASTWARD ACROSS CENTRAL NEW YORK AROUND
SUNRISE. ITS EVOLUTION & TRACK WILL BE MONITORED THIS EVENING FOR
ANY SHIFT NORTHWARD. THOUGH THE ENTIRE NORTH COUNTRY WILL STAND TO
SEE SHOWERS/THUNDERSTORMS TOWARDS MORNING DUE TO THE STRONG WARM
ADVECTION & ISENTROPIC LIFT THAT WILL BE TAKING PLACE...I SUSPECT
THE BEST CHANCE AT THUNDERSTORMS WOULD BE FOR OUR SOUTHWESTERN CWA
AREAS /FROM AN OGDENSBURG-SARANAC LAKE-NEWCOMB LINE/. I HAVE
RAISED POPS ACCORDINGLY IN THE ADIRONDACKS AND SOUTHERN SAINT
LAWRENCE COUNTY TO BETTER REFLECT ABOVE REASONING. UNTIL
THEN...EXPECT SKIES TO CONTINUE TO FILL IN WITH TEMPERATURES
LEVELING OFF BEFORE RISING TOWARDS MORNING.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 325 PM EDT MONDAY...ACTIVE PERIOD OF WEATHER CONTINUES ON
TUESDAY...WITH THE POTENTIAL FOR A FEW STRONG-SEVERE
THUNDERSTORMS. MORNING SHOWERS/TSTORMS ASSOCIATED WITH STRONG WAA
AND CONVECTIVE COMPLEX SHOULD PUSH EAST OF THE REGION BY AROUND
15Z. AT THE SAME TIME THE SURFACE WARM FRONT WILL LIFT
NORTHEASTWARD AND BE DRAPED ACROSS THE AREA...LIKELY BISECTING
THE REGION. THE POSITION OF THIS WARM FRONT IS QUITE CRITICAL FOR
ANY SEVERE CONVECTIVE THREAT. ON SOUTH SIDE OF FRONT...EXPECTING
AT LEAST PARTIAL CLEARING LEADING TO DEVELOPMENT OF 1000-2000
J/KG OF MLCAPE BY LATE WEDNESDAY. THIS COMBINED WITH NEAR 50
KNOTS OF 0-6KM SHEAR AND 20-30 KNOTS OF 0-1KM SHEAR WILL LEAD TO
A CONDITIONAL THREAT OF SEVERE WEATHER. FORECAST SOUNDINGS FOR
TUESDAY AFTERNOON AT BTV/SLK/OGS SHOW CAPPING INVERSION LIMITING
OVERALL CONVECTIVE INITIATION. THUS WILL BE RELYING ON RELATIVELY
WEAK FORCING WITH POSSIBLE LEFTOVER BOUNDARIES FROM EARLY MORNING
CONVECTION OR THE WARM FRONT ITSELF. ON THE COOLER NORTH SIDE OF
BOUNDARY...ANY CONVECTIVE ACTIVITY IS LIKELY TO BE MORE ELEVATED
IN NATURE. THAT ALL BEING SAID...CURRENT THINKING IS THAT WARM
FRONT WILL BE SITUATED FROM THE SAINT LAWRENCE VALLEY ACROSS THE
ADIRONDACKS AND INTO THE CHAMPLAIN VALLEY...WITH THE BEST THREAT
OF ISOLATED SEVERE WEATHER FROM THE CHAMPLAIN VALLEY WESTWARD
ACROSS THE ADIRONDACKS AND INTO THE SAINT LAWRENCE VALLEY WHERE
CONVERGENCE MAY BE ENHANCED BY NORTHEAST FLOW DOWN THE NORTHERN
SAINT LAWRENCE VALLEY. WHILE COVERAGE IS EXPECTED TO BE
LIMITED...ANY THUNDERSTORM THAT MAY DEVELOP ALONG THE WARM FRONT
HAS THE POTENTIAL TO BECOME SEVERE WITH LARGE HAIL...DAMAGING
WINDS...HEAVY RAIN...AND A VERY LOW CHANCE OF A TORNADO.
OTHERWISE...HIGHS WILL ALSO BE VERY DEPENDENT ON POSITION OF WARM
FRONT WITH LOW 80S ON THE WARM SIDE AND LOW 70S ON THE COOL SIDE.
SYNOPTIC WIND GUSTS OUTSIDE OF THUNDERSTORM ACTIVITY WILL LIKELY
REACH 20-30 MPH ON WARM SIDE OF FRONT IN PRONOUNCED SOUTHWEST
FLOW.
THE FRONTAL BOUNDARY WILL REMAIN NEAR THE REGION INTO TUESDAY
NIGHT...WITH INSTABILITY REMAINING...ESPECIALLY ALOFT WITH
PRESENCE OF AN ELEVATED MIXED LAYER. THIS COMBINED WITH ABUNDANT
MOISTURE...AS NOTED BY 1.5-2" PRECIPITABLE WATER VALUES...WILL
KEEP THE CHANCE OF SHOWERS/THUNDERSTORMS AROUND THROUGH THE
NIGHT. TEMPERATURES WILL HAVE TROUBLE FALLING...SO LOOKING AT A
LOT OF UPPER 60S AND LOWER 70S.
POTENTIALLY MORE WIDESPREAD STRONG-SEVERE THUNDERSTORMS ARE
POSSIBLE LATER WEDNESDAY. THE WEAK BOUNDARY WILL REMAIN NEAR THE
REGION...AND FORCING WILL BE ENHANCED BY THE APPROACH OF AN UPPER
TROUGH FROM THE WEST...ESPECIALLY LATER WEDNESDAY AND INTO
WEDNESDAY NIGHT. THE AREA IS EXPECTED TO BE LARGELY INTO THE WARM
SECTOR WITH WIDESPREAD 80S FOR HIGHS...POSSIBLY EVEN A SPOT 90F
IN THE CHAMPLAIN VALLEY. THIS COUPLED WITH DEW POINTS IN THE
UPPER 60S TO NEAR 70 WILL PRODUCE A VERY UNSTABLE AIRMASS WITH
UPWARDS OF 2000 J/KG OF MLCAPE. SHEAR PROFILES STILL LOOK VERY
FAVORABLE FOR STRONG-SEVERE THUNDERSTORM DEVELOPMENT WITH 40-50
KNOTS OF 0-6KM SHEAR ANTICIPATED. 0-1KM SHEAR VALUES ARE
SIGNIFICANTLY LOWER THAN TUESDAY...WITH MAIN POTENTIAL IMPACTS
BEING LARGE HAIL AND DAMAGING WINDS. GREATEST THREAT OF SEVERE
THUNDERSTORMS SHOULD BE 21Z-03Z. GIVEN HIGH MOISTURE
CONTENT...HEAVY RAIN AND MINOR FLOODING WILL BE POSSIBLE IN ANY
THUNDERSTORMS.
COLD FRONT NEARS THE REGION LATER WEDNESDAY NIGHT WITH POTENTIAL
FOR ELEVATED CONVECTIVE ACTIVITY CONTINUING. STRONG SOUTHWEST FLOW
IS ALSO MAINTAINED SO LOWS IN THE UPPER 60S/LOWER 70S LOOK GOOD
AGAIN.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 345 PM EDT MONDAY...COLD FRONT WILL MOVE THROUGH THE NORTH
COUNTRY FROM WEST TO EAST THURSDAY INTO THURSDAY NIGHT...
PRODUCING SHOWERS AND THUNDERSTORMS ACROSS THE AREA. THIS FRONT
WILL EXIT SERN VT EARLY FRIDAY MORNING WITH LINGERING SHOWERS
PSBL AS THE ASSOCIATED UPPER LEVEL TROUGH BRINGS A POTENT
SHORTWAVE THRU THE REGION ON FRIDAY...KEEPING SKIES MOSTLY
CLOUDY. NW-N WINDS WILL INCREASE AT THE SFC WITH TIGHT PRESSURE
GRADIENT IN PLACE AS A RIDGE OF HIGH PRESSURE BUILD OVER THE
GREAT LAKES REGION. COLDER AIR WILL USHER IN ON THE NORTHERLY
FLOW BEHIND THE AFOREMENTIONED COLD FRONT WITH 850MB TEMPS
DROPPING TO 0C-2C BY LATE FRIDAY. THIS WILL BRING THE SLIGHTLY
WARMER THAN NORMAL TEMPS OF M-U70S ON THURSDAY COOLING TO THE
M50S-L60S ON FRIDAY...WITH MIN TEMPS IN THE 30S-L40S.
THE UPPER LEVEL TROUGH WILL EXIT TO THE EAST SOMETIME LATE
SATURDAY INTO EARLY SUNDAY...WITH CLOUDS DECREASING OVER THE AREA
AND RIDGE OF HIGH PRESSURE AT THE SFC SLIDING EAST...CENTERED
OVER SRN NY/NRN PA AREA. THIS WILL BRING SRLY FLOW AND MODERATING
TEMPERATURES TO THE NORTH COUNTRY SUNDAY AND MONDAY. MAX TEMPS
WILL BE IN THE M-U60S AND MIN TEMPS IN THE U30S-U40S.
MODEL GUIDANCE DIVERGES ON SOLNS TOWARD THE END OF THE PERIOD.
HIGH PRESSURE LOOKS TO KEEP THINGS DRY THROUGH AT LEAST SUNDAY
NT/EARLY MONDAY. GFS BRINGS ANOTHER LOW PRESSURE SYSTEM ACROSS
THE ERN GREAT LAKES BY MONDAY AFTN...WITH ANOTHER COLD FRONT
DRAPED TO THE SW BRINGING SHOWERS AND PSBL TSTMS TO END THE
PERIOD. THE 12Z ECMWF KEEPS THE HIGH PRESSURE OVER THE AREA
THROUGH LATE TUESDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
THROUGH 00Z WEDNESDAY...VFR CONDS EXPECTED THROUGH 08-10Z WITH
SCT/BKN HIGH CLOUDS AND LIGHT SOUTHERLY FLOW FROM 3-8 KTS.
EXCEPTION AT KRUT WHERE SOUTHEASTERLY DRAINAGE FLOWS AROUND 10KTS
EXPECTED OVERNIGHT. APPROACH OF STRONG WARM FRONT TOWARD TUESDAY
MORNING WILL BRING A PERIOD OF SCT SHOWERS/ISOLD THUNDER TO MOST
TERMINALS IN THE 08-14Z TIME FRAME. DRY CONDS MAY PREVAIL AT KRUT.
MAINLY VFR AS ACTIVITY PASSES THOUGH SOME BKN/OVC MVFR CIGS
POSSIBLE AT KMSS/KSLK/KMPV THROUGH THE MORNING HOURS ON TUESDAY.
AFTER 16-18Z WARM FRONT SLOWLY LIFTS TO THE INTL BORDER WITH
INCREASINGLY GUSTY SOUTH/SOUTHWESTERLY FLOW. SOME GUSTS TO 25 KTS
POSSIBLE AT KBTV/KPBG. WHILE THREAT CONDITIONAL...NATL STORM
PREDICTION CENTER CONTINUES TO HIGHLIGHT AREA IN SLIGHT RISK OF
SVR WX LATER TOMORROW/TOMORROW EVENING ON THE SOUTHERN SIDE OF THE
FRONT. HAVE KEPT MOST TERMINALS DRY DUE TO UNCERTAINTY OF
CONVECTIVE DEVELOPMENT. PLEASE NOTE HOWEVER THAT IF ANY STORMS CAN
FORM...THREAT OF ISOLD STRONG/SVR WX IS POSSIBLE.
OUTLOOK 00Z WEDNESDAY THROUGH SATURDAY...
PRIMARILY VFR...THOUGH PERIODS OF IFR/MVFR VSBYS WITH SCATTERED
SHOWERS AND THUNDERSTORMS AS WARM FRONT MOVES THROUGH REGION
TUESDAY FOLLOWED BY COLD FRONTAL PASSAGE THURSDAY. A FEW OF THE
STORMS MAY BE STRONG TO LOCALLY SEVERE TUESDAY EVENING ALONG THE
INTL BORDER...AND ACROSS THE ENTIRE FCST AREA WEDNESDAY AFTERNOON
AND EVENING. ANY STORMS THAT DO BECOME SEVERE MAY CONTAIN STRONG
TURBULENCE...LARGE HAIL AND STRONG SFC WINDS. THE UPPER LEVEL
TROUGH ASSOCIATED WITH THESE FRONTS WILL MOVE THROUGH
FRIDAY...KEEPING A THREAT OF SHOWERS OVER THE NORTH COUNTRY
THROUGH LATE FRIDAY. SATURDAY HIGH PRESSURE WILL BUILD IN AT THE
SFC.
&&
.EQUIPMENT...
AS OF 719 PM EDT SATURDAY...NOAA WEATHER RADIO STATION WXM 44,
BROADCASTING FROM THE TOP OF MOUNT ASCUTNEY VERMONT...REMAINS OFF
THE AIR DUE TO A DAMAGED ANTENNA. REPLACEMENT PARTS HAVE BEEN
ORDERED AND THE REPAIR WORK HAS NOW BEEN SCHEDULED FOR SEPTEMBER
17-20.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MUCCILLI
NEAR TERM...LOCONTO/MUCCILLI
SHORT TERM...MUCCILLI
LONG TERM...KGM
AVIATION...JMG/KGM
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1143 PM CDT MON SEP 9 2013
.UPDATE...
ISSUED AT 1143 PM CDT MON SEP 9 2013
MADE FURTHER ADJUSTMENTS TO POPS AS A LINE OF THUNDERSTORMS MOVES
THROUGH THE DEVILS LAKE AREA TONIGHT. THINK THERE WILL CONTINUE TO
BE A WEAKENING TREND BUT KEPT POPS IN THE LIKELY TO HIGH CHANCE
RANGE FOR A WHILE FOR THE NORTHWEST TO NORTH CENTRAL COUNTIES.
THINK THAT THE SHORTWAVE WILL CONTINUE TO PRODUCE LIFT AND PRECIP
ALTHOUGH INSTABILITY WILL BE LACKING AS WE CONTINUE THROUGH THE
NIGHT.
UPDATE ISSUED AT 931 PM CDT MON SEP 9 2013
BUMPED UP POPS INTO THE 50-60 PERCENT RANGE IN THE DEVILS LAKE
BASIN FOR THE REST OF THE EVENING AS THE LINE OF STORMS OVER NORTH
CENTRAL ND HAS HELD TOGETHER. NAM AND HRRR HAVE THE STORMS
CONTINUING THROUGH THE DEVILS LAKE BASIN BEFORE DIMINISHING AS
THEY MOVE FURTHER EAST. THINK THAT THERE WILL BE SOME WEAKENING
AND DISSIPATING AS THE LINE MOVES FURTHER EAST INTO STABLE AIR
OVER THE NORTHERN RED RIVER VALLEY SO KEPT POPS AROUND 30-40
ACROSS THE REST OF THE NORTHERN FORECAST AREA.
A FEW SPOTS HAVE LOWERED IN VISIBILITY THIS EVENING...BUT NO DENSE
FOG YET. WILL CONTINUE JUST TO KEEP A PATCHY MENTION FOR NOW AS
WITH WINDS SHIFTING WEST BEHIND THE WEAK SFC TROUGH THERE SHOULD
BE SOME MIXING AND SLIGHTLY DRIER AIR MOVING IN.
UPDATE ISSUED AT 629 PM CDT MON SEP 9 2013
RADAR TRENDS SHOW US FAIRLY QUIET FOR THE TIME BEING EXCEPT FOR
SOME LIGHT SHOWERS OR DRIZZLE IN SOME SPOTS. CONVECTION OUT IN
NORTHWESTERN ND IS ON TRACK TO MOVE INTO THE NORTHWESTERN COUNTIES
LATER ON THIS EVENING. HOWEVER...THE NAM AND HRRR SHOW THE
ACTIVITY DISSIPATING BEFORE GETTING VERY FAR INTO OUR AREA. A FEW
OF THE OTHER SOLUTIONS KEEP SOME PRECIP MOVING IN...BUT GIVEN THE
LACK OF EVEN ELEVATED INSTABILITY AM NOT OPTIMISTIC. CONTINUED TO
KEEP 30-40 POPS GOING IN THE NORTH FOR ANYTHING HOLDING TOGETHER
AS THE SHORTWAVE MOVES EAST THIS EVENING BUT WILL HOLD OFF ON ANY
RAISING OR LOWERING OF POPS AT THIS POINT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 300 PM CDT MON SEP 9 2013
THE GFS IS DOING THE BEST JOB INITIALIZING THE CURRENT DEFORMATION
RAIN BAND...SO WILL UTILIZE THIS SOLUTION WITH NO MODEL DOING VERY
WELL OF LATE.
FOR TONIGHT...EXPECT SHOWERS AND A FEW STORMS MAINLY IN THE
NORTHERN 1/3 OF THE AREA. A FEW STORMS COULD EVEN BE STRONG TO
PERHAPS LOCALLY SEVERE IN THE DVL BASIN...WITH LARGE HAIL
POSSIBLE/STRONG IF SOME INSOLATION DEVELOPS LATE THIS AFTERNOON.
THERE IS ALSO SOME LINGERING INSTABILITY IN THE SOUTH AND EAST
THROUGH THIS EVENING AHEAD OF THE SFC BOUNDARY...SO A FEW STRONG
STORMS ALSO POSSIBLE THERE. SINCE THIS AREA HAS BEEN UNDER CLOUDS
ALL DAY...NOT ANTICIPATING TOO MUCH WIDESPREAD ACTIVITY HERE EITHER.
THERE SHOULD ALSO BE PATCHY FOG IN ALL AREAS TONIGHT...GIVEN VERY
HIGH LOW LEVEL MOISTURE. IF AREAS CLEAR OUT MORE LATER
TONIGHT...THEN FOG COULD BECOME LOCALLY DENSE BUT EXPECTING CLOUDS
TO REMAIN IN MOST AREAS TONIGHT.
ON TUE...THE UPPER WAVE WILL MOVE SLOWLY EAST AND THERE COULD BE A
FEW SHOWERS/STORMS MAINLY IN THE NORTH. TEMPS WILL BE A BIT WARMER
THAN TODAY WITH MORE SUNSHINE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 300 PM CDT MON SEP 9 2013
FOR WED/THU...EXPECT DRY AND COOL WEATHER WITH HIGH PRESSURE
BUILDING INTO THE REGION. THERE WILL ALSO BE PLENTIFUL SUNSHINE
WITH DEEP LAYERED SUBSIDENCE AND A DRY AIRMASS IN PLACE...SO IT
WILL BE COOL OVERNIGHT.
THURSDAY NIGHT THROUGH MONDAY...12 UTC GFS/ECMWF IN GOOD AGREEMENT
THROUGH 00 UTC SATURDAY...DIVERGING THEREAFTER WITH INTERACTION
BETWEEN A HUDSON BAY TROUGH AND A STAGNANT GREAT BASIN CLOSED LOW.
GENERAL SYNOPTIC IDEA SHOWS A CANADIAN TROUGH MOVING INTO HUDSON
BAY BY 00 UTC SUNDAY AND IN THE PROCESS ENVELOPES A CLOSED LOW
ACROSS THE CENTRAL ROCKIES. WITH THIS PATTERN...TWO POTENTIAL AREAS
OF PRECIPITATION COULD DEVELOP ACROSS THE FORECAST AREA ON SATURDAY.
THE FIRST IS ASSOCIATED WITH THE CANADIAN COLD FRONT DROPPING SOUTH
AND THE SECOND IS FROM WARM AIR ADVECTION ASSOCIATED WITH THE CLOSED
LOW TO THE SOUTH. THE ECMWF IS MOST BULLISH WITH PRECIPITATION FROM
THE SOUTH...WHEREAS THE GFS/DGEX/GEM ARE FARTHER SOUTH AND DRIER
ACROSS THE FORECAST AREA. WILL COVER THIS IN THE GRIDS WITH CHANCE
POPS SPREADING FROM WEST TO EAST FRIDAY NIGHT THROUGH SATURDAY
NIGHT. REST OF THE PERIOD SHOULD BE DRY WITH SURFACE HIGH PRESSURE
ACROSS THE REGION. TEMPERATURES WILL BE MUCH CLOSER TO SEASONAL
NORMALS WITH HIGHS FROM THE MID 60S TO LOWER 70S AND LOWS FROM THE
MID 40S TO MID 50S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1143 PM CDT MON SEP 9 2013
THE NORTHEASTERN TAF SITES HAVE STAYED MVFR AND LOWER WHILE KFAR
AND KDVL HAVE SEEN SOME IMPROVEMENT TO VFR. STORMS MOVING THROUGH
THE KDVL AREA WILL BE THROUGH BY THE TIME THE 06Z TAFS COME INTO
EFFECT. THERE WILL BE A LOT OF LOW LEVEL MOISTURE TONIGHT
PARTICULARLY IN THE NORTHERN COUNTIES WHICH WILL SEE THE MOST
RECENT RAIN. THINK THAT VIS GOING DOWN TO 3-5SM IS POSSIBLE...WITH
SOME MODEL GUIDENCE SHOWING KBJI DOWN TO LESS THAN 1SM. WILL KEEP
AN EYE ON IT BUT JUST WENT 1SM FOR NOW. MVFR CIGS HAVE ALREADY
ENTERED NORTHWESTERN ND AND WILL CONTINUE TO MOVE THROUGH OUR
NORTHERN COUNTIES SO CONDITIONS SHOULD GO BACK DOWN AT KDVL. THINK
THAT KFAR HAS THE BEST CHANCE OF STAYING VFR. CONDITIONS SHOULD
IMPROVE AT ALL TAF SITES BY LATE MORNING...ALTHOUGH SOME MVFR
COULD HANG ON A BIT LONGER AT KBJI.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...DK
LONG TERM...DK/ROGERS
AVIATION...JR
AREA FORECAST DISCUSSION...UPDATED
NWS CLEVELAND OH
919 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/...
EXPECT SOME OF THE TSRA OVER LAKE ERIE TO MOVE ACROSS EXTREME NE
OH/NW PA LATE THIS EVENING...THEN MORE TSRA DEVELOPMENT NEAR
FRONT TO MOVE INTO NW OH AND CENTRAL LAKESHORE LATE TONIGHT. FOR
NOW TEMPS LOOK REASONABLE.
ORIGINAL DISCUSSION...
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 /01Z THURSDAY 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...DJB/MULLEN
SHORT TERM...MULLEN
LONG TERM...ADAMS
AVIATION...ADAMS
MARINE...ADAMS
AREA FORECAST DISCUSSION...UPDATED
NWS CLEVELAND OH
715 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/...
DROPPED WATCH AS CONVECTION HAS MOVED EAST. STRONGEST STORMS SE
LOWER MICHIGAN WELL NORTH OF THE AREA AND MOVING BASICALLY EAST SO
DOES NOT LOOK LIKE IT WILL IMPACT FORECAST AREA THIS EVENING.
ORIGINAL DISCUSSION...
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 /23Z 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...DJB/MULLEN
SHORT TERM...MULLEN
LONG TERM...ADAMS
AVIATION...ADAMS
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
440 AM EDT TUE SEP 10 2013
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE HOT AND HUMID CONDITIONS THROUGH
WEDNESDAY. A COLD FRONT WILL PUSH THROUGH ON THURSDAY WITH
SHOWERS AND THUNDERSTORMS. MUCH COOLER AIR WILL SETTLE IN BEHIND
THE FRONT FOR THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AREA WILL BE UNDER A HOT AND HUMID SOUTHWEST FLOW BETWEEN HIGH
PRESSURE CENTERED OVER THE CAROLINAS AND LOW PRESSURE PUSHING
ACROSS SOUTHERN CANADA. THERE IS LITTLE FORCING FOR OUR AREA IN
THIS REGIME...THOUGH ISOLATED THUNDERSTORMS WILL BE POSSIBLE THIS
AFTERNOON IN A MODERATELY UNSTABLE ENVIRONMENT.
HIGH TEMPERATURES IN THE LOWER 90S WILL COMBINE WITH DEW POINTS
IN THE UPPER 60S TO PRODUCE HEAT INDICES IN THE UPPER
90S...APPROACHING CRITERIA FOR HEAT ADVISORY, WILL ISSUE SPS TO
HIGHLIGHT HEAT PROBLEMS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
PARTLY CLOUDY AND DRY WEATHER IS EXPECTED FOR TONIGHT. ON
WEDNESDAY...HIGH PRESSURE WILL WEAKEN IN RESPONSE TO SHORT WAVE
ENERGY. THUNDERSTORMS WILL BE POSSIBLE WEDNESDAY AFTERNOON AS THE
SHORT WAVE ENERGY INTERACTS WITH THE PERSISTENTLY UNSTABLE
AIRMASS. CLOUD FORMATION MAY ALLOW TEMPERATURES TO STAY A FEW
DEGREES COOLER ON WEDNESDAY...WITH HIGHS AROUND 90.
AN EAST-WEST ORIENTED COLD FRONT WILL BE DROPPING FROM THE GREAT
LAKES LATE WEDNESDAY NIGHT...BEFORE CROSSING THE AREA ON THURSDAY.
THIS WILL BRING THE LIKELIHOOD FOR SHOWERS AND THUNDERSTORMS.
THERE WILL BE MODERATE SHEAR AND INSTABILITY ALONG AND AHEAD OF
THE FRONT...BUT THE FRONT ARRIVING BEFORE PEAK HEATING MAY REDUCE
THE CHANCE FOR SEVERE THUNDERSTORMS. COLD ADVECTION...CLOUDS AND
PRECIP WILL ALLOW FOR HIGHS IN THE 80S ON THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
COLD FRONT WILL CLEAR THE REGION BY THURSDAY NIGHT.
HIGH PRESSURE WILL BUILD ACROSS THE REGION FRIDAY THROUGH SUNDAY.
TEMPERATURES WILL DROP BELOW NORMAL INITIALLY. BUT THEN READINGS
SHOULD REBOUND CLOSER TO SEASONAL AVERAGE BY SUNDAY AS SOUTHERLY
FLOW RETURNS ON THE BACK SIDE OF THE HIGH. UNCERTAINTY INCREASES ON
MONDAY AS 12Z MODELS DIVERGE ON WHETHER ANOTHER COLD FRONT WILL PUSH
INTO THE REGION. AT THIS POINT HAVE SIDED WITH 12Z GEFS MEAN WHICH
IS NOT TOO FAR FROM WPC GUIDANCE.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
MID LEVEL RIDGE TO BUILD EAST BECOMING CENTERED OVER THE TN VLY
TODAY. IN THE MOIST SRLY FLOW...SATL IMGRY SHOWING THE DEVELOPMENT
OF CLOUDS BETWEEN 5000 AND 7000 FEET. LATEST RAP MODEL SHOWS THIS
INCREASE IN LOW LEVEL RH GENERALLY ALONG AND SOUTHEAST OF I-71.
THESE CLOUDS WILL BE BROKEN AT TIMES AND WILL MITIGATE THE
DEVELOPMENT OF WIDESPREAD FOG. THEREFORE...HAVE LIMITED MENTION OF
VSBY RESTRICTION TO MVFR FOR A FEW HOURS PRIOR TO SUNRISE AT
KCVG/KLUK...KILN AND KLCK.
VFR CONDITIONS WITH FEW TO SCT CU AND SOUTHWEST WINDS AROUND 10 KT
ARE EXPECTED DURG THE DAY ON TUESDAY. FROM THE LATE MORNING
THROUGH THE EARLY EVENING. ISOLATED SHOWERS AND THUNDERSTORMS MAY
OCCUR DURING THE AFTERNOON AND EARLY EVENING. HOWEVER...THE LACK
OF FORCING AND MID LEVEL RIDGE IN PLACE WILL LIMIT COVERAGE.
THEREFORE...WILL KEEP THE MENTION OF PRECIPITATION OUT OF THIS TAF
PACKAGE.
OUTLOOK...THUNDERSTORMS POSSIBLE WEDNESDAY NIGHT INTO THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...CONIGLIO
NEAR TERM...CONIGLIO
SHORT TERM...CONIGLIO
LONG TERM...
AVIATION...AR
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
113 AM EDT TUE SEP 10 2013
.SYNOPSIS...
HOT AND HUMID CONDITIONS WILL BE PRESENT THROUGH WEDNESDAY. A COLD
FRONT WILL MOVE THROUGH THE REGION WEDNESDAY NIGHT INTO THURSDAY.
HIGH PRESSURE WILL BUILD INTO THE AREA FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A WARM AND HUMID AIRMASS REMAINS IN PLACE TONIGHT WITH HIGH
PRESSURE CENTERED TO OUR SOUTH. MOST CLOUD COVER HAS DISSIPATED
ACROSS OUR AREA THIS EVENING AND MOSTLY CLEAR SKIES ARE EXPECTED
OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
EXPECT TUESDAY TO BE THE WARMEST DAY OF THE WEEK WITH TEMPERATURES
ACROSS THE FA IN THE LOWER 90S. HEAT INDEX VALUES WILL BE IN THE
MIDDLE AND UPPER 90S WHICH IS JUST BELOW HEAT ADVISORY CRITERIA.
WILL CONTINUE TO MENTION THE HEAT IN THE HWO. THERE IS A SLIGHT
CHANCE FOR A COUPLE OF ISOLATED THUNDERSTORMS DURING THE DAYTIME
HOURS ON TUESDAY ACROSS THE SOUTHERN HALF OF THE FA WITH THE
UNSTABLE AIRMASS. EXPECT ANY THUNDERSTORM ACTIVITY TO DECREASE
DURING THE EVENING HOURS ON TUESDAY AND FOR DRY CONDITIONS TO
CONTINUE THROUGH THE NIGHT TUESDAY NIGHT.
ADDITIONAL THUNDERSTORM DEVELOPMENT WILL BE POSSIBLE DURING THE
DAYTIME HOURS ON WEDNESDAY. EXPECT MORE THUNDERSTORM ACTIVITY ON
WEDNESDAY THAN ON TUESDAY. ADDITIONAL CLOUD COVER AND
PRECIPITATION ON WEDNESDAY WILL KEEP TEMPERATURES A COUPLE OF
DEGREES COOLER ON WEDNESDAY THAN ON TUESDAY. THIS THUNDERSTORM
ACTIVITY WILL DECREASE DURING BY SUNSET HOWEVER ADDITIONAL
THUNDERSTORMS WILL BE EDGING TOWARDS THE AREA AS A COLD FRONT
APPROACHES THE REGION. ADDITIONAL THUNDERSTORM ACTIVITY WILL
SPREAD INTO THE FA WEDNESDAY NIGHT WITH THE BEST CHANCE OF
PRECIPITATION ACROSS NORTHERN PORTIONS OF THE FA.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
COLD FRONT WILL CONTINUE PUSHING THROUGH THE REGION THURSDAY.
SOMEWHAT UNCERTAIN HOW EXTENSIVE CONVECTION WILL BE WITH THE
BOUNDARY. THERE IS SOME INDICATION THAT THERE COULD BE WEAKENING IN
THE MORNING AND THEN REDEVELOPMENT IN THE AFTERNOON. THIS WILL ALL
CLEAR THE REGION BY THURSDAY NIGHT.
HIGH PRESSURE WILL BUILD ACROSS THE REGION FRIDAY THROUGH SUNDAY.
TEMPERATURES WILL DROP BELOW NORMAL INITIALLY. BUT THEN READINGS
SHOULD REBOUND CLOSER TO SEASONAL AVERAGE BY SUNDAY AS SOUTHERLY
FLOW RETURNS ON THE BACK SIDE OF THE HIGH. UNCERTAINTY INCREASES ON
MONDAY AS 12Z MODELS DIVERGE ON WHETHER ANOTHER COLD FRONT WILL PUSH
INTO THE REGION. AT THIS POINT HAVE SIDED WITH 12Z GEFS MEAN WHICH
IS NOT TOO FAR FROM WPC GUIDANCE.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
MID LEVEL RIDGE TO BUILD EAST BECOMING CENTERED OVER THE TN VLY
TODAY. IN THE MOIST SRLY FLOW...SATL IMGRY SHOWING THE DEVELOPMENT
OF CLOUDS BETWEEN 5000 AND 7000 FEET. LATEST RAP MODEL SHOWS THIS
INCREASE IN LOW LEVEL RH GENERALLY ALONG AND SOUTHEAST OF I-71.
THESE CLOUDS WILL BE BROKEN AT TIMES AND WILL MITIGATE THE
DEVELOPMENT OF WIDESPREAD FOG. THEREFORE...HAVE LIMITED MENTION OF
VSBY RESTRICTION TO MVFR FOR A FEW HOURS PRIOR TO SUNRISE AT
KCVG/KLUK...KILN AND KLCK.
VFR CONDITIONS WITH FEW TO SCT CU AND SOUTHWEST WINDS AROUND 10 KT
ARE EXPECTED DURG THE DAY ON TUESDAY. FROM THE LATE MORNING
THROUGH THE EARLY EVENING. ISOLATED SHOWERS AND THUNDERSTORMS MAY
OCCUR DURING THE AFTERNOON AND EARLY EVENING. HOWEVER...THE LACK
OF FORCING AND MID LEVEL RIDGE IN PLACE WILL LIMIT COVERAGE.
THEREFORE...WILL KEEP THE MENTION OF PRECIPITATION OUT OF THIS TAF
PACKAGE.
OUTLOOK...THUNDERSTORMS POSSIBLE WEDNESDAY NIGHT INTO THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...NOVAK
NEAR TERM...LATTO
SHORT TERM...NOVAK
LONG TERM...
AVIATION...AR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
256 AM EDT TUE SEP 10 2013
.SYNOPSIS...
A WARM FRONT WILL PUSH THROUGH THE REGION LATER THIS MORNING.
UNSEASONABLY HOT AND HUMID CONDITIONS ARE EXPECTED THROUGH MIDWEEK
WITH SCATTERED SHOWERS AND THUNDERSTORMS. SHARPLY COOLER
CONDITIONS WILL ARRIVE BEHIND A COLD FRONT THURSDAY...WITH BELOW
NORMAL TEMPERATURES FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SFC WARM FRONT PUSHING INTO NORTHWEST PA EARLY THIS MORNING.
INCREASING BOUNDARY LAYER MOISTURE WITH JUST ENOUGH CONVERGENCE TO
MAINTAIN ISOLATED COVERAGE OF LIGHT SHOWERS FROM SOUTHERN ONTARIO
TO THE PA LAKE ERIE SHORELINE. EARLIER ACTIVITY HAS EXITED
EASTWARD AND DWINDLED ACROSS THE SOUTH CENTRAL MOUNTAINS AND
MIDDLE SUSQ RIVER VALLEY...BUT UPSTREAM MOISTURE FLUX WITH AN
AMPLIFYING 850 MB THETA-E RIDGE AND BOUNDARY LAYER CONVERGENCE OVER
ACROSS WRN AND NRN PA WILL KEEP ISOLATED SHOWERS GOING FOR THE
NEXT FEW TO SEVERAL HOURS. NOT ANTICIPATING MUCH MORE THAN TRACE
AMOUNTS IN MOST AREAS.
ANOTHER ISSUE CONCERNS THE POTENTIAL OF FOG IN THE PRE DAWN HOURS.
AREA MOST LIKELY TO SEE SIG VSBY REDUCTIONS WILL BE JUST NORTH OF
THE WARM FRONT ACROSS NE PA. LATEST SREF AND RAP SUPPORT THIS
SCENARIO WITH THE NE COUNTIES SEEING THE HIGHEST PROBS OF LOW VSBY
AND HIGHEST SFC RH/S RESPECTIVELY.
CLOUD COVER AND INCREASING HUMIDITY WILL LEAD TO A MUCH MILDER
NIGHT WITH LOWS RANGING FROM THE U50S ACROSS THE N MTNS...TO BTWN
60-65F ELSEWHERE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM WEDNESDAY/...
WARM FRONT SHOULD PUSH NE OF THE ENTIRE AREA BY LATE AM...BRINGING
CLEARING SKIES AND RAPIDLY RISING TEMPS. BASED ON UPSTREAM CONDS THIS
AFTN ACROSS THE UPPER MIDWEST...LOOKS LIKE MID SUMMER HEAT AND
HUMIDITY BY TUE AFTN WITH HIGHS APPROACHING 90F IN MANY LOCATIONS.
AN ISOLATED PM SHOWER OR STORM CANNOT BE RULED OUT BUT WITH MODEL
FCST TEMPS IN THE MID LEVELS TOPPING 10C...THE CAP WILL BE PRETTY
HARD TO BREAK. WILL KEEP POPS OF ONLY ARND 10 PCT.
PARTLY TO MOSTLY CLOUDY SKIES TUESDAY NIGHT WITHIN THE EXTENSIVE
WARM SECTOR...WILL COMBINE WITH A SOUTHERLY LIGHT WIND AND SFC
DEWPOINTS IN THE MID TO UPPER 60S...LEADING TO A MUGGY NIGHT WITH
JUST A SCHC FOR TSRA PERSISTING ACROSS NRN PENN.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
ANOMALOUS UPPER RIDGE TO START THE PERIOD WILL BE DISPLACED BY A
DEEP UPPER TROF DROPPING SOUTHWARD FROM THE NORTHERN TERRITORIES
MID TO LATE WEEK. SFC COLD FRONT TIMING STILL APPEARS TO BE
THURSDAY MORNING...WITH THE CORE OF COLDEST AIR AT 850 MB REACHING
CENTRAL PA BY 12Z SAT. LATEST GUIDANCE SUGGESTS THE 850 MB ZERO
LINE DROPS SOUTH OF THE PA/NY BORDER THIS SATURDAY MORNING AS THE
UPPER TROF CLOSES OFF OVER CENTRAL AND SOUTHERN NEW ENGLAND. THIS
WILL SET THE STAGE FOR IMPRESSIVE DROPOFFS IN TEMPERATURE AFTER
MUCH ABOVE NORMAL MIDWEEK HIGHS VISIT THE COMMONWEALTH.
WEDNESDAY WILL LIKELY BE THE HOTTEST DAY UNTIL LATER NEXT SPRING
OR SUMMER...WITH HIGH TEMPS REACHING INTO THE MID 80S /MTNS/ AND
LOWER 90S ACROSS THE LOWER SUSQ VALLEY.
A PRE-FRONTAL/LEE TROF WILL LIKELY DEVELOP ACROSS THE SUSQ VALLEY
WEDNESDAY...HELPING TO FOCUS THE BEST CHC FOR AT LEAST SCATTERED
AFTERNOON TSRA THERE. ACROSS THE NW...THE FIRST OF TWO SFC CFRONTS
WILL APPROACH LATER IN THE DAY/EVENING...SPARKING A BKN BAND OF
SHOWERS AND SCATTERED TSRA.
A PAIR OF COLD FRONTS WILL MOVES SE ACROSS THE STATE WED NIGHT AND
THURSDAY...WITH ANOTHER ROUND OR TO OF SHOWERS/TSRA. FOR LATE IN
THE WEEK AND OVER THE UPCOMING WEEKEND...A SPRAWLING/COOL CANADIAN
HIGH AND ANOMALOUSLY DEEP UPPER TROUGH WILL MOVE SOUTHEAST FROM
THE GLAKES...BRINGING A RETURN TO MUCH LOWER DEWPOINTS AND BELOW
NORMAL TEMPS.
THE ZERO C 850 MB ISOTHERM /IN THE LATEST...03Z SREF/ WILL MOVE OVER
THE NRN GREAT LAKES REGION THURSDAY...BEFORE DIVING SOUTHEAST TO
MAKE A RARE EARLY SEASON APPEARANCE NEAR THE PA/NY BORDER AND
SOUTHERN NEW ENGLAND COAST FRIDAY INTO EARLY SATURDAY. THESE -2 TO
-3 SIGMA TEMPS AT 850 MB WILL UNDOUBTEDLY LEAD TO WIDESPREAD COLD
AIR STRATO CU WITH LAKE EFFECT AND OROGRAPHICALLY ENHANCED
SHOWERS. WE MAY BE UNDERPLAYING THE AMOUNT OF CLOUDS AND POPS FOR
FRIDAY AND SATURDAY HERE IN CENTRAL AND NRN PENN WITHIN THE
COLD...GUSTY AND WELL-ALIGNED DEEP NWRLY FLOW.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
COMPLEX AVN FCST FOR EARLY THIS MORNING. HIGHEST CONFIDENCE IN
LOW CLOUDS IMPACTING THE ERN TERMINALS WITH MVFR/IFR CIGS. THE WRN
AND CNTRL AIRFIELDS COULD SEE SHALLOW STRATUS AND FOG FORM THRU
THE PREDAWN HOURS...AS LLVL MSTR CONTINUES TO INCREASE ALONG WARM
FNT. BFD IS THE MOST LKLY CANDIDATE FOR IFR GIVEN RESIDUAL MSTR
FROM EARLIER RAIN. SOME HI-RES MDL DATA ALSO WANTS TO DEVELOP AN
AREA OF TSTMS OVER THE LWR LKS AND BRING THEM INTO N-CNTRL PA BY
12Z. WITH NOTHING SIGNIFICANT ON UPSTREAM RADAR AS OF 06Z..WILL
MONITOR RADAR TRENDS CLOSELY AND AMD IF TSTM THREAT BECOMES MORE
DEFINED. AS THE WARM FRONT SHIFTS NORTH OF THE AREA LATER
TODAY...EXPECT A.M. VIS/CIG RESTRICTIONS TO IMPROVE TO VFR FOR
BY LATE MORNING WITH VFR PREVAILING THRU THE AFTN/EVE. VERY WARM
AIR ALOFT WILL MOVE OVER THE AIRSPACE THIS AFTN AND ACT AS A CAP
TO PREVENT/LIMIT DIURNAL CONVECTION. LGT WINDS AND DEWPOINTS IN
THE 60S SHOULD FAVOR AREAS OF FOG OVERNIGHT.
OUTLOOK...
WED...SCT PM TSTM IMPACTS PSBL.
THU...SCT-NMRS TSTM IMPACTS PSBL WITH COLD FROPA.
FRI...MVFR/SCT SHOWERS PSBL N/W...VFR CENTRAL/EAST. BREEZY.
SAT...VFR. NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/LA CORTE
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...DEVOIR/GARTNER/MARTIN
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
207 AM EDT TUE SEP 10 2013
.SYNOPSIS...
A WARM FRONT WILL PUSH THROUGH THE REGION LATER THIS MORNING.
UNSEASONABLY HOT AND HUMID CONDITIONS ARE EXPECTED THROUGH MIDWEEK
WITH SCATTERED SHOWERS AND THUNDERSTORMS. SHARPLY COOLER
CONDITIONS WILL ARRIVE BEHIND A COLD FRONT THURSDAY...WITH BELOW
NORMAL TEMPERATURES FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SFC WARM FRONT PUSHING INTO NORTHWEST PA EARLY THIS MORNING.
INCREASING BOUNDARY LAYER MOISTURE WITH JUST ENOUGH CONVERGENCE TO
MAINTAIN ISOLATED COVERAGE OF LIGHT SHOWERS FROM SOUTHERN ONTARIO
TO THE PA LAKE ERIE SHORELINE. EARLIER ACTIVITY HAS EXITED
EASTWARD AND DWINDLED ACROSS THE SOUTH CENTRAL MOUNTAINS AND
MIDDLE SUSQ RIVER VALLEY...BUT UPSTREAM MOISTURE FLUX WITH AN
AMPLIFYING 850 MB THETA-E RIDGE AND BOUNDARY LAYER CONVERGENCE OVER
ACROSS WRN AND NRN PA WILL KEEP ISOLATED SHOWERS GOING FOR THE
NEXT FEW TO SEVERAL HOURS. NOT ANTICIPATING MUCH MORE THAN TRACE
AMOUNTS IN MOST AREAS.
ANOTHER ISSUE CONCERNS THE POTENTIAL OF FOG IN THE PRE DAWN HOURS.
AREA MOST LIKELY TO SEE SIG VSBY REDUCTIONS WILL BE JUST NORTH OF
THE WARM FRONT ACROSS NE PA. LATEST SREF AND RAP SUPPORT THIS
SCENARIO WITH THE NE COUNTIES SEEING THE HIGHEST PROBS OF LOW VSBY
AND HIGHEST SFC RH/S RESPECTIVELY.
CLOUD COVER AND INCREASING HUMIDITY WILL LEAD TO A MUCH MILDER
NIGHT WITH LOWS RANGING FROM THE U50S ACROSS THE N MTNS...TO BTWN
60-65F ELSEWHERE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
WARM FRONT SHOULD PUSH NE OF THE ENTIRE AREA BY LATE AM...BRINGING
CLEARING SKIES AND RAPIDLY RISING TEMPS. BASED ON UPSTREAM CONDS THIS
AFTN ACROSS THE UPPER MIDWEST...LOOKS LIKE MID SUMMER HEAT AND
HUMIDITY BY TUE AFTN WITH HIGHS APPROACHING 90F IN MANY LOCATIONS.
AN ISOLATED PM SHOWER OR STORM CANNOT BE RULED OUT BUT WITH MODEL
FCST TEMPS IN THE MID LEVELS TOPPING 10C...THE CAP WILL BE PRETTY
HARD TO BREAK. WILL KEEP POPS OF ONLY ARND 10 PCT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
PARTLY TO MOSTLY CLOUDY SKIES TUESDAY NIGHT WITHIN THE EXTENSIVE
WARM SECTOR...WILL COMBINE WITH A SOUTHERLY LIGHT WIND AND SFC
DEWPOINTS IN THE MID TO UPPER 60S...LEADING TO A MUGGY NIGHT WITH
JUST A SCHC FOR TSRA PERSISTING ACROSS NRN PENN.
LIKELY THE HOTTEST DAY UNTIL LATER NEXT SPRING OR SUMMER WILL OCCUR
WEDNESDAY...WITH HIGH TEMPS REACHING INTO THE MID 80S /MTNS/ AND
LOWER 90S ACROSS THE LOWER SUSQ VALLEY.
A PRE-FRONTAL/LEE TROF WILL LIKELY DEVELOP ACROSS THE SUSQ VALLEY
WEDNESDAY...HELPING TO FOCUS THE BEST CHC FOR AT LEAST SCATTERED
AFTERNOON TSRA THERE. ACROSS THE NW...THE FIRST OF TWO SFC CFRONTS
WILL APPROACH LATER IN THE DAY/EVENING...SPARKING A BKN BAND OF
SHOWERS AND SCATTERED TSRA.
THE PAIR OF COLD FRONTS WILL MOVES SE ACROSS THE STATE WED NIGHT AND
THURSDAY...WITH ANOTHER ROUND OR TO OF SHOWERS/TSRA. FOR LATE IN THE
WEEK AND OVER THE UPCOMING WEEKEND...A SPRAWLING/COOL CANADIAN HIGH
AND ANOMALOUSLY DEEP UPPER TROUGH WILL MOVE SOUTHEAST FROM THE
GLAKES...BRINGING A RETURN TO MUCH LOWER DEWPOINTS AND BELOW NORMAL
TEMPS.
THE ZERO C 850 MB ISOTHERM /IN THE LATEST...03Z SREF/ WILL MOVE OVER
THE NRN GREAT LAKES REGION THURSDAY...BEFORE DIVING SOUTHEAST TO
MAKE A RARE EARLY SEASON APPEARANCE NEAR THE PENN/NEW YORK BORDER
AND SOUTHERN NEW ENGLAND COAST FRIDAY INTO EARLY SATURDAY. THESE -2
TO -3 SIGMA TEMPS AT 850 MB WILL UNDOUBTEDLY LEAD TO WIDESPREAD COLD
AIR STRATO CU WITH LAKE EFFECT AND OROGRAPHICALLY ENHANCED SHOWERS.
WE MAY BE UNDERPLAYING THE AMOUNT OF CLOUDS AND POPS FOR FRIDAY AND
SATURDAY HERE IN CENTRAL AND NRN PENN WITHIN THE COLD...GUSTY AND
WELL-ALIGNED DEEP NWRLY FLOW.
SO...IN SUMMARY...THE MAIN STORIES FOR THIS PERIOD WILL BE THE HEAT
TO START...SCATTERED STRONG TO SEVERE STORMS POSSIBLE LATER TUESDAY
AND WEDNESDAY...MAINLY NORTH OF THE REGION/...AND THE UNSEASONABLY
CHILLY AIRMASS TO CLOSE IT OUT.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
COMPLEX AVN FCST FOR EARLY THIS MORNING. HIGHEST CONFIDENCE IN
LOW CLOUDS IMPACTING THE ERN TERMINALS WITH MVFR/IFR CIGS. THE WRN
AND CNTRL AIRFIELDS COULD SEE SHALLOW STRATUS AND FOG FORM THRU
THE PREDAWN HOURS...AS LLVL MSTR CONTINUES TO INCREASE ALONG WARM
FNT. BFD IS THE MOST LKLY CANDIDATE FOR IFR GIVEN RESIDUAL MSTR
FROM EARLIER RAIN. SOME HI-RES MDL DATA ALSO WANTS TO DEVELOP AN
AREA OF TSTMS OVER THE LWR LKS AND BRING THEM INTO N-CNTRL PA BY
12Z. WITH NOTHING SIGNIFICANT ON UPSTREAM RADAR AS OF 06Z..WILL
MONITOR RADAR TRENDS CLOSELY AND AMD IF TSTM THREAT BECOMES MORE
DEFINED. AS THE WARM FRONT SHIFTS NORTH OF THE AREA LATER
TODAY...EXPECT A.M. VIS/CIG RESTRICTIONS TO IMPROVE TO VFR FOR
BY LATE MORNING WITH VFR PREVAILING THRU THE AFTN/EVE. VERY WARM
AIR ALOFT WILL MOVE OVER THE AIRSPACE THIS AFTN AND ACT AS A CAP
TO PREVENT/LIMIT DIURNAL CONVECTION. LGT WINDS AND DEWPOINTS IN
THE 60S SHOULD FAVOR AREAS OF FOG OVERNIGHT.
OUTLOOK...
WED...SCT PM TSTM IMPACTS PSBL.
THU...SCT-NMRS TSTM IMPACTS PSBL WITH COLD FROPA.
FRI...MVFR/SCT SHOWERS PSBL N/W...VFR CENTRAL/EAST. BREEZY.
SAT...VFR. NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD/LA CORTE
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...GARTNER/MARTIN
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
111 AM EDT TUE SEP 10 2013
.SYNOPSIS...
A WARM FRONT WILL PUSH THROUGH THE REGION LATER THIS MORNING.
UNSEASONABLY HOT AND HUMID CONDITIONS ARE EXPECTED THROUGH MIDWEEK
WITH SCATTERED SHOWERS AND THUNDERSTORMS. SHARPLY COOLER
CONDITIONS WILL ARRIVE BEHIND A COLD FRONT THURSDAY...WITH BELOW
NORMAL TEMPERATURES FRIDAY INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SFC WARM FRONT PUSHING INTO NORTHWEST PA EARLY THIS MORNING.
INCREASING BOUNDARY LAYER MOISTURE WITH JUST ENOUGH CONVERGENCE TO
MAINTAIN ISOLATED COVERAGE OF LIGHT SHOWERS FROM SOUTHERN ONTARIO
TO THE PA LAKE ERIE SHORELINE. EARLIER ACTIVITY HAS EXITED
EASTWARD AND DWINDLED ACROSS THE SOUTH CENTRAL MOUNTAINS AND
MIDDLE SUSQ RIVER VALLEY...BUT UPSTREAM MOISTURE FLUX WITH AN
AMPLIFYING 850 MB THTE RIDGE AND BOUNDARY LAYER CONVERGENCE OVER
ACROSS WRN AND NRN PA WILL KEEP ISOLATED SHOWERS GOING FOR THE
NEXT FEW TO SEVERAL HOURS. NOT ANTICIPATING MUCH MORE THAN TRACE
AMOUNTS IN MOST AREAS.
ANOTHER ISSUE CONCERNS THE POTENTIAL OF FOG IN THE PRE DAWN HOURS.
AREA MOST LIKELY TO SEE SIG VSBY REDUCTIONS WILL BE JUST NORTH OF
THE WARM FRONT ACROSS NE PA. LATEST SREF AND RAP SUPPORT THIS
SCENARIO WITH THE NE COUNTIES SEEING THE HIGHEST PROBS OF LOW VSBY
AND HIGHEST SFC RH/S RESPECTIVELY.
CLOUD COVER AND INCREASING HUMIDITY WILL LEAD TO A MUCH MILDER
NIGHT WITH LOWS RANGING FROM THE U50S ACROSS THE N MTNS...TO BTWN
60-65F ELSEWHERE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
WARM FRONT SHOULD PUSH NE OF THE ENTIRE AREA BY LATE AM...BRINGING
CLEARING SKIES AND RAPIDLY RISING TEMPS. BASED ON UPSTREAM CONDS THIS
AFTN ACROSS THE UPPER MIDWEST...LOOKS LIKE MID SUMMER HEAT AND
HUMIDITY BY TUE AFTN WITH HIGHS APPROACHING 90F IN MANY LOCATIONS.
AN ISOLATED PM SHOWER OR STORM CANNOT BE RULED OUT BUT WITH MODEL
FCST TEMPS IN THE MID LEVELS TOPPING 10C...THE CAP WILL BE PRETTY
HARD TO BREAK. WILL KEEP POPS OF ONLY ARND 10 PCT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
PARTLY TO MOSTLY CLOUDY SKIES TUESDAY NIGHT WITHIN THE EXTENSIVE
WARM SECTOR...WILL COMBINE WITH A SOUTHERLY LIGHT WIND AND SFC
DEWPOINTS IN THE MID TO UPPER 60S...LEADING TO A MUGGY NIGHT WITH
JUST A SCHC FOR TSRA PERSISTING ACROSS NRN PENN.
LIKELY THE HOTTEST DAY UNTIL LATER NEXT SPRING OR SUMMER WILL OCCUR
WEDNESDAY...WITH HIGH TEMPS REACHING INTO THE MID 80S /MTNS/ AND
LOWER 90S ACROSS THE LOWER SUSQ VALLEY.
A PRE-FRONTAL/LEE TROF WILL LIKELY DEVELOP ACROSS THE SUSQ VALLEY
WEDNESDAY...HELPING TO FOCUS THE BEST CHC FOR AT LEAST SCATTERED
AFTERNOON TSRA THERE. ACROSS THE NW...THE FIRST OF TWO SFC CFRONTS
WILL APPROACH LATER IN THE DAY/EVENING...SPARKING A BKN BAND OF
SHOWERS AND SCATTERED TSRA.
THE PAIR OF COLD FRONTS WILL MOVES SE ACROSS THE STATE WED NIGHT AND
THURSDAY...WITH ANOTHER ROUND OR TO OF SHOWERS/TSRA. FOR LATE IN THE
WEEK AND OVER THE UPCOMING WEEKEND...A SPRAWLING/COOL CANADIAN HIGH
AND ANOMALOUSLY DEEP UPPER TROUGH WILL MOVE SOUTHEAST FROM THE
GLAKES...BRINGING A RETURN TO MUCH LOWER DEWPOINTS AND BELOW NORMAL
TEMPS.
THE ZERO C 850 MB ISOTHERM /IN THE LATEST...03Z SREF/ WILL MOVE OVER
THE NRN GREAT LAKES REGION THURSDAY...BEFORE DIVING SOUTHEAST TO
MAKE A RARE EARLY SEASON APPEARANCE NEAR THE PENN/NEW YORK BORDER
AND SOUTHERN NEW ENGLAND COAST FRIDAY INTO EARLY SATURDAY. THESE -2
TO -3 SIGMA TEMPS AT 850 MB WILL UNDOUBTEDLY LEAD TO WIDESPREAD COLD
AIR STRATO CU WITH LAKE EFFECT AND OROGRAPHICALLY ENHANCED SHOWERS.
WE MAY BE UNDERPLAYING THE AMOUNT OF CLOUDS AND POPS FOR FRIDAY AND
SATURDAY HERE IN CENTRAL AND NRN PENN WITHIN THE COLD...GUSTY AND
WELL-ALIGNED DEEP NWRLY FLOW.
SO...IN SUMMARY...THE MAIN STORIES FOR THIS PERIOD WILL BE THE HEAT
TO START...SCATTERED STRONG TO SEVERE STORMS POSSIBLE LATER TUESDAY
AND WEDNESDAY...MAINLY NORTH OF THE REGION/...AND THE UNSEASONABLY
CHILLY AIRMASS TO CLOSE IT OUT.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
ONLY A FEW ADJUSTMENTS BASED ON CURRENT RADAR.
EARLIER DISCUSSION BELOW.
FEW LOWER CLDS AT TIMES EARLIER THIS AFT IN RETURN FLOW.
MAIN THING OVERNIGHT WILL BE A FEW SHOWERS...PERHAPS A
RUMBLE OF THUNDER...AS WARM FRONT MOVES INTO THE AREA. VERY
HOT AIRMASS TO THE WEST...DEWPOINTS QUITE HIGH...THUS WILL
HAVE TO MONITOR FOR NEW STORM DEVELOPMENT TO THE WEST.
WENT WITH VFR CONDITIONS ON TUE. EML TYPE AIRMASS WILL LIKELY
KEEP MID LVL TEMPS WARM ENOUGH TO PREVENT SHOWERS AND STORM
FORMATION...SO LEFT THEM OUT OF THE TAFS FOR NOW.
IT WILL BE BREEZY OUT...ESPECIALLY ACROSS NW PA...GIVEN BLAST
OF HOT AIR FROM THE PLAINS.
SIMILAR CONDITIONS FOR WED...MORE IN THE WAY OF A CHC OF A
SHOWER OR STORM...ESPECIALLY LATE...AS THE COLD FRONT NEARS.
MUCH COOLER AND BREEZY CONDITIONS FOR LATE WEEK...AS HIGH
PRESSURE BUILDS SE FROM CANADA.
OUTLOOK...
WED...SCT PM TSTM IMPACTS PSBL.
THU...SCT-NMRS TSTM IMPACTS PSBL WITH COLD FROPA.
FRI...MVFR/SCT SHOWERS PSBL N/W...VFR CENTRAL/EAST.
SAT...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR/
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...GARTNER/MARTIN
AVIATION...MARTIN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1225 PM CDT TUE SEP 10 2013
.UPDATE...
UPDATED AVIATION DISCUSSION BELOW FOR 18Z TAFS.
SOME RR QUADRANT JET STREAK AND MID LEVEL FRONTAL ZONE CLOUDS
WILL STREAM OVER THE CWA FROM SOUTHWEST TO NORTHEAST THROUGH THE
DAY. ALSO...VISIBLE SATELLITE SHOWS STRATUS/STRATOCU CLOUDS
HEADING SOUTH INTO NORTHERN SD/WEST CENTRAL MN LATE THIS MORNING.
THESE ARE EXPECTED TO MIX OUT SOME AND BE MORE SCATTERED AS THEY
MOVE ACROSS THE EASTERN PART OF THE CWA. OVERALL...SKIES WILL BE
PARTLY CLOUDY THROUGH THE DAY WITH STEADY NORTHWEST BREEZES.
EXPECT ANY SHOWER/THUNDER ACTIVITY TO REMAIN SOUTH OF OUR CWA THIS
AFTERNOON ALONG THE FRONTAL ZONE. MIXED OUT HIGHS WILL BE AROUND
80 TO 85 DEGREES BY LATE AFTERNOON. FORECAST LOOKS GOOD.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH THURSDAY
A BAND OF RAIN SHOWERS CONTINUES ACROSS PARTS OF SOUTH CENTRAL
SOUTH DAKOTA THROUGH WEST CENTRAL MINNESOTA THIS MORNING. THIS IS
MAINLY INFLUENCING THE SIOUX FALLS CWA...HOWEVER...IT DOES REQUIRE
POPS ACROSS THE FAR SOUTHERN TIER OF COUNTIES THROUGH MOST OF THE
MORNING HOURS TODAY. THIS IS CURRENTLY THE ONLY CHANCE FOR
PRECIPITATION THROUGH THE SHORT TERM FORECAST...AS THE ENERGY
ASSOCIATED WITH THE UPPER SHORTWAVE TROUGH MOVES NORTHEAST INTO
THE ONTARIO REGION TODAY. NORTHWEST FLOW FOLLOWS....AND WILL
PREVAIL ACROSS THE DAKOTAS THROUGH THE SHORT TERM. ANOTHER TROUGH
DOES DROP OUT OF CANADA AND ACROSS NORTH DAKOTA ON WEDNESDAY...BUT
THE BEST FORCING WILL REMAIN NORTH AND EAST OF THIS CWA. AN
ASSOCIATED SURFACE COLD FRONT WILL DROP SOUTHWARD AS WELL. SO WITH
SLIGHTLY ABOVE NORMAL TEMPERATURES TODAY AND WEDNESDAY...TEMPERATURES
WILL DROP TO NEAR NORMAL VALUES ON WEDNESDAY NIGHT AND THURSDAY
BEHIND THE FRONT. THE SURFACE HIGH CENTER WILL REMAIN IN
CANADA...HOWEVER THE RIDGE WILL EXTEND ACROSS THE DAKOTAS AND
WINDS WILL GO LIGHT THURSDAY MORNING. ALONG WITH COLD AIR
ADVECTION AND CLEAR SKIES...THURSDAY MORNING LOWS WILL BE DROPPING
INTO THE MID 40S ACROSS THE NORTH. HIGHS ON THURSDAY WILL THEN BE
IN THE LOW TO UPPER 70S.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
A COOL/DRY CANADIAN-SOURCED AIRMASS SHOULD BE SETTING UP SHOP
ACROSS THE CWA AS THE PERIOD OPENS. A RATHER AMPLIFIED/BLOCKY
UPPER FLOW PATTERN WILL ONLY HAD ANOTHER LAYER OF FORECAST
DIFFICULTY TO SYSTEM TIMING/PLACEMENT/STRENGTH OVER THE WEEKEND AS
AN UPPER LOW DEPICTED IN WATER VAPOR IMAGERY OUT OVER ARIZONA
MEANDERS ITS WAY UP INTO THE CENTRAL/NORTHERN PLAINS. THE 00Z
GFS/CANADIAN/ECMWF DETERMINISTIC SOLUTIONS ALL CONTINUE TO SPREAD
PRECIPITATION UP INTO THE CWA LATE FRIDAY NIGHT. THE PRECIP SHIELD
THEN SLOWLY SPREADS NORTH AND EAST ACROSS THE CWA
SATURDAY/SATURDAY NIGHT. NOT A WHOLE LOT OF STEERING FLOW ALOFT
OVER THE CWA DURING THE EXTENDED FORECAST PERIOD. SO...IF THE RAIN
FORECAST PANS OUT...THERE IS CERTAINLY THE POTENTIAL FOR A
RAIN-COOLED BOUNDARY LAYER TO SATURATE BY SATURDAY NIGHT AND
PRODUCE EITHER FOG OR LOW STRATUS. WITHOUT A REAL NOTEWORTHY
PRESSURE FIELD/GRADIENT OR MIXING WIND ANTICIPATED...PARTIAL TO
WIDESPREAD STRATUS CONDITIONS COULD BE ADDING A NEW WRINKLE TO THE
FORECAST FOR SUNDAY/MONDAY.
DURING THE FORECAST PERIOD...TEMPERATURES ARE NOT EXPECTED TO STRAY
MORE THAN A FEW DEGREES EITHER SIDE OF CLIMO NORM FOR
MID-SEPTEMBER.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD WITH A WNW
BREEZE AND PASSING MID/HIGH LEVEL CLOUDS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...MOHR/TMT
SHORT TERM...SERR
LONG TERM...DORN
AVIATION...TMT
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1052 AM CDT TUE SEP 10 2013
.UPDATE...
SOME RR QUADRANT JET STREAK AND MID LEVEL FRONTAL ZONE CLOUDS
WILL STREAM OVER THE CWA FROM SOUTHWEST TO NORTHEAST THROUGH THE
DAY. ALSO...VISIBLE SATELLITE SHOWS STRATUS/STRATOCU CLOUDS
HEADING SOUTH INTO NORTHERN SD/WEST CENTRAL MN LATE THIS MORNING.
THESE ARE EXPECTED TO MIX OUT SOME AND BE MORE SCATTERED AS THEY
MOVE ACROSS THE EASTERN PART OF THE CWA. OVERALL...SKIES WILL BE
PARTLY CLOUDY THROUGH THE DAY WITH STEADY NORTHWEST BREEZES.
EXPECT ANY SHOWER/THUNDER ACTIVITY TO REMAIN SOUTH OF OUR CWA THIS
AFTERNOON ALONG THE FRONTAL ZONE. MIXED OUT HIGHS WILL BE AROUND
80 TO 85 DEGREES BY LATE AFTERNOON. FORECAST LOOKS GOOD.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH THURSDAY
A BAND OF RAIN SHOWERS CONTINUES ACROSS PARTS OF SOUTH CENTRAL
SOUTH DAKOTA THROUGH WEST CENTRAL MINNESOTA THIS MORNING. THIS IS
MAINLY INFLUENCING THE SIOUX FALLS CWA...HOWEVER...IT DOES REQUIRE
POPS ACROSS THE FAR SOUTHERN TIER OF COUNTIES THROUGH MOST OF THE
MORNING HOURS TODAY. THIS IS CURRENTLY THE ONLY CHANCE FOR
PRECIPITATION THROUGH THE SHORT TERM FORECAST...AS THE ENERGY
ASSOCIATED WITH THE UPPER SHORTWAVE TROUGH MOVES NORTHEAST INTO
THE ONTARIO REGION TODAY. NORTHWEST FLOW FOLLOWS....AND WILL
PREVAIL ACROSS THE DAKOTAS THROUGH THE SHORT TERM. ANOTHER TROUGH
DOES DROP OUT OF CANADA AND ACROSS NORTH DAKOTA ON WEDNESDAY...BUT
THE BEST FORCING WILL REMAIN NORTH AND EAST OF THIS CWA. AN
ASSOCIATED SURFACE COLD FRONT WILL DROP SOUTHWARD AS WELL. SO WITH
SLIGHTLY ABOVE NORMAL TEMPERATURES TODAY AND WEDNESDAY...TEMPERATURES
WILL DROP TO NEAR NORMAL VALUES ON WEDNESDAY NIGHT AND THURSDAY
BEHIND THE FRONT. THE SURFACE HIGH CENTER WILL REMAIN IN
CANADA...HOWEVER THE RIDGE WILL EXTEND ACROSS THE DAKOTAS AND
WINDS WILL GO LIGHT THURSDAY MORNING. ALONG WITH COLD AIR
ADVECTION AND CLEAR SKIES...THURSDAY MORNING LOWS WILL BE DROPPING
INTO THE MID 40S ACROSS THE NORTH. HIGHS ON THURSDAY WILL THEN BE
IN THE LOW TO UPPER 70S.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
A COOL/DRY CANADIAN-SOURCED AIRMASS SHOULD BE SETTING UP SHOP
ACROSS THE CWA AS THE PERIOD OPENS. A RATHER AMPLIFIED/BLOCKY
UPPER FLOW PATTERN WILL ONLY HAD ANOTHER LAYER OF FORECAST
DIFFICULTY TO SYSTEM TIMING/PLACEMENT/STRENGTH OVER THE WEEKEND AS
AN UPPER LOW DEPICTED IN WATER VAPOR IMAGERY OUT OVER ARIZONA
MEANDERS ITS WAY UP INTO THE CENTRAL/NORTHERN PLAINS. THE 00Z
GFS/CANADIAN/ECMWF DETERMINISTIC SOLUTIONS ALL CONTINUE TO SPREAD
PRECIPITATION UP INTO THE CWA LATE FRIDAY NIGHT. THE PRECIP SHIELD
THEN SLOWLY SPREADS NORTH AND EAST ACROSS THE CWA
SATURDAY/SATURDAY NIGHT. NOT A WHOLE LOT OF STEERING FLOW ALOFT
OVER THE CWA DURING THE EXTENDED FORECAST PERIOD. SO...IF THE RAIN
FORECAST PANS OUT...THERE IS CERTAINLY THE POTENTIAL FOR A
RAIN-COOLED BOUNDARY LAYER TO SATURATE BY SATURDAY NIGHT AND
PRODUCE EITHER FOG OR LOW STRATUS. WITHOUT A REAL NOTEWORTHY
PRESSURE FIELD/GRADIENT OR MIXING WIND ANTICIPATED...PARTIAL TO
WIDESPREAD STRATUS CONDITIONS COULD BE ADDING A NEW WRINKLE TO THE
FORECAST FOR SUNDAY/MONDAY.
DURING THE FORECAST PERIOD...TEMPERATURES ARE NOT EXPECTED TO STRAY
MORE THAN A FEW DEGREES EITHER SIDE OF CLIMO NORM FOR
MID-SEPTEMBER.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
ONE MORE RAIN SHOWER SHOULD BE AFFECTING THE KATY TERMINAL RIGHT
AT THE START OF THE TAF VALID PERIOD FOR JUST A SHORT WHILE.
THEN...ALL FOUR TERMINALS SHOULD SEE DRY CONDITIONS THROUGH
WEDNESDAY MORNING. THERE IS SOME IFR/MVFR STRATUS TRYING TO WORK
DOWN OUT OF NORTH DAKOTA EARLY THIS MORNING. COULD SEE A TEMPORARY
SUB-VFR STRATUS CEILING SPREADING OVER THE KABR TERMINAL THIS
MORNING AS THE MORNING SUN IS WORKING TO MIX THINGS OUT.
OTHERWISE...ALL FOUR TERMINALS SHOULD BE EXPERIENCING VFR FLYING
WEATHER CONDITIONS ON A LIGHT WEST-NORTHWEST WIND.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...MOHR
SHORT TERM...SERR
LONG TERM...DORN
AVIATION...DORN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1248 PM CDT TUE SEP 10 2013
.DISCUSSION...SEE 18Z AVIATION DISCUSSION.
&&
.AVIATION...MAIN ISSUE IS THE CONVECTION THIS AFTERNOON AND THIS
EVENING (A BIT LESS OF A CONCERN FOR 12Z-18Z WEDNESDAY).
CONVECTION ON THE WANE NEAR THE COAST...BUT STILL A POTENTIAL FOR
SOMETHING IN KCRP BEFORE 20Z SO HAD TO KEEP VCTS. FARTHER WEST AND
NORTH...POTENTIAL FOR CONVECTION (TSRA) AT KVCT AND KALI TIL ABOUT
22Z/23Z...THEN AT KLRD TIL ABOUT 11/00Z. WINDS SHOULD BEGIN TO
INCREASE WITH END OF CONVECTION ALL SITES (OBVIOUSLY THE FARTHER
EAST THE SOONER IN THE TERMINAL FORECAST)...BUT THEN DIE DOWN
AGAIN AND MAINLY EAST A COUPLE OF HOURS AFTER SUNSET. DRIER MID
LEVEL AIR STARTS TO COME IN TONIGHT FROM THE NORTHEAST...SO THINK
ANY CONVECTIVE ACTIVITY FOR WEDNESDAY THROUGH 18Z WILL BE
RESTRICTED TO THE KCRP AND KALI TERMINALS. HOWEVER...WITH IT BEING
SO LATE IN THE FORECAST...WILL ONLY GO WITH VCTS AND KCRP AND VCSH
AT KALI AFTER 12Z (NO MENTION ELSEWHERE)...SINCE CONFIDENCE IN
GETTING INTO THE TERMINAL ITSELF IS NOT HIGH. CONCERNING CIGS
OUTSIDE OF CONVECTION...AM EXPECTING MVFR CONDITIONS AT KLRD TWD
12Z WEDNESDAY OTHERWISE VFR CONDITIONS FOR CIGS. CONCERNING FOG
OUTSIDE OF CONVECTION...MAY SEE SOME AT KVCT AGAIN TOWARD 12Z BUT
FOR NOW AM ONLY GOING TO GO WITH NEAR MVFR 08Z ENDING BY 14Z. EAST
WINDS LESS THAN 11 KNOTS AFTER 12Z WEDNESDAY.
&&
.PREV DISCUSSION... /ISSUED 1011 AM CDT TUE SEP 10 2013/
DISCUSSION...LOWERED TEMPERATURES MAINLY SOUTHEASTERN SECTIONS
AND INCREASED POPS JUST A TAD OVER THE SOUTHERN COASTAL AREAS. RUC
AND HRRR IS SHOWING CONVECTION CONTINUING NEAR THE SOUTHERN
COASTAL AREAS FROM TIME TO TIME TIL EARLY AFTERNOON BEFORE MOST
OF IT PUSHES INLAND. CAN BELIEVE THIS GIVEN RADAR TRENDS/HISTORY
AND OBSERVED/FORECAST SURFACE FORCING. MORNING SOUNDING VERY
WET...WITH LITTLE TO NO CONVECTIVE INHIBITION. THUS...SCATTERED
CONVECTION (MORE NUMEROUS SOUTHERN COASTAL AREAS) SEEMS REASONABLE
THIS MORNING...WITH ACTIVITY PUSHING FARTHER WEST DURING THE
AFTERNOON ONCE ENOUGH DAYTIME HEATING GETS GOING TO GET A SEA-
BREEZE STARTED. OTHER ADJUSTMENTS TO FIRST AND SECOND PERIOD
GRIDS. PRODUCTS ARE OUT. MARINE FORECAST FOR NOW LOOKS REASONABLE.
PREV DISCUSSION... /ISSUED 643 AM CDT TUE SEP 10 2013/
DISCUSSION...UPDATED FOR THE 12Z AVIATION DISCUSSION.
AVIATION...GENERAL VFR CONDITIONS...WITH BRIEF MVFR CIGS/IFR
VSBYS IN AND AROUND SHOWERS/STORMS. RAIN COVERAGE IS EXPECTED TO
INCREASE...ESPECIALLY ACROSS THE COASTAL PLAINS FROM CRP-ALI-VCT
THROUGH THE LATE MRNG/EARLY AFTN. ISOLATED DEVELOPMENT IS EXPECTED
TO REACH LRD BY MID AFTN...THEREFORE WILL ONLY MAINTAIN VCTS IN
TAFS FOR NOW. THE TROPICAL AIRMASS WILL LEAD TO MOSTLY SHOWER
ACTIVITY...HOWEVER WITH ADDITIONAL HEATING AND WEAK UPPER LEVEL
SUPPORT...THUNDER REMAINS POSSIBLE DURING THE LATE MRNG/AFTN/EVNG
HOURS. ACTIVITY SHOULD WANE FROM EAST TO WEST THROUGH THE EVENING.
GENERAL EASTERLY WINDS 10-15 KTS ARE EXPECTED TO DEVELOP INTO THE
AFTERNOON BEFORE DECOUPLING THIS EVENING.
PREV DISCUSSION... /ISSUED 417 AM CDT TUE SEP 10 2013/
SHORT TERM (TODAY THROUGH WEDNESDAY)...ISOLATED SHOWERS DEVELOPING
ACROSS PORTIONS OF SOUTH TEXAS THIS MORNING DUE TO PWATS NEAR 2
AND SURFACE COASTAL TROUGH SOUTH OF THE AREA WITH WEAK PVA AT H5
ACROSS THE NORTHEASTERN CWA. ADDITIONAL COVERAGE IS EXPECTED TO
DEVELOP THROUGH THE LATE MORNING AND AFTERNOON...WITH HIGHER
CHANCE POPS MAINLY ACROSS THE EASTERN HALF OF THE CWA. AN UPPER
WEAK JET STREAK SHOULD PROVIDE A BIT MORE DIFFLUENT FLOW ACROSS
THE AREA...WHICH MAY LEAD TO A FEW STORMS BECOMING STRONG THIS
AFTERNOON...PARTICULARLY OVER THE COASTAL PLAINS. OTHERWISE...MOST
ACTIVITY SHOULD REMAIN AS SHOWERS WITH GENERAL THUNDER. DUE TO
DEEP TROPICAL MOISTURE...LOCALLY HEAVY RAINFALL CAN BE
EXPERIENCED. RAIN CHANCES WILL THEN TAPER OFF THROUGH THE EVENING
HOURS WITH THE LOSS OF HEATING. THE MID/UPPER LEVEL RIDGE ACROSS
THE EASTERN U.S. WILL SLOWLY SHIFT WESTWARD THROUGH WEDNESDAY WITH
DRIER AIR APPROACHING FROM THE NORTHEAST. HOWEVER PWATS NEAR 1.8
INCHES WILL REMAIN ACROSS THE SOUTH TEXAS...LEADING TO A SLIGHT
CHANCE TO LOW END CHANCE POPS FOR SHOWERS THROUGH WEDNESDAY. AS
FOR TEMPERATURES...HIGHS ARE DEPENDENT ON CLOUD AND RAIN
COVERAGE...HOWEVER WITH BETTER CHANCES FOR RAIN ACROSS THE COASTAL
BEND...WILL MAINTAIN TEMPS IN THE UPPER 80S...WITH LOWER 90S
FARTHER INLAND. SLIGHTLY WARMER TEMPERATURES ARE EXPECTED FOR
WEDNESDAY.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...MODELS CONTINUE TO
INDICATED MID LEVEL DRYING OCCURS FROM NORTHEAST TO SOUTHWEST
THURSDAY AND FRIDAY...AS THE MID AND UPPER LEVEL RIDGE ACROSS THE
SOUTHEAST U.S. BUILDS BACK TO THE WEST. PRECIPITABLE WATER VALUES
FALL TO 1.6-1.8 INCHES ON THURSDAY AND TO LESS THAN 1.5 INCHES ON
FRIDAY. EXPECT COVERAGE OF SHOWERS AND THUNDERSTORMS TO DECREASE
TO ISOLATED...WITH BEST CHANCES FOR PRECIP MAINLY ACROSS MARINE AND
SOUTHERN AREAS OF THE CWA.
ATTENTION SHIFTS TO THE BAY OF CAMPECHE DURING THE LATTER HALF OF
THE WEEK AND INTO THE WEEKEND. AN AREA OF DISTURBED WEATHER LOCATED
OVER THE NORTHWESTERN CARIBBEAN SEA IS MOVING WESTWARD AND IS
FORECAST TO MOVE ACROSS THE YUCATAN PENINSULA AND INTO THE BAY OF
CAMPECHE BY LATE THURSDAY. MODELS ARE INDICATING AN AREA OF BROAD
LOW PRESSURE TO FORM IN THE BAY OF CAMPECHE...AND NHC HAS
HIGHLIGHTED THIS REGION FOR A HIGH CHANCE OF TROPICAL CYCLONE
DEVELOPMENT DURING THIS TIME. GFS AND ECMWF INDICATE EITHER WAVE OR
CLOSED LOW MOVING WEST-NORTHWEST INTO VERACRUZ OR TAMAULIPAS MEXICO
SUNDAY OR MONDAY. HOWEVER...MODELS ARE INDICATING THE MID AND UPPER
LEVEL RIDGE ACROSS TO BUILD BACK INTO THE SOUTHEAST U.S. DURING THIS
TIME...ALLOWING DEEP SURGE OF TROPICAL MOISTURE NORTH OF THE
POTENTIAL SYSTEM TO POSSIBLY MAKE IT INTO SOUTH TEXAS. HAVE RAISED
POPS INTO THE HIGH END SCATTERED RANGE SUNDAY AND MONDAY AND LOWERED
FORECAST HIGHS. FURTHER FORECAST ADJUSTMENTS SUNDAY AND MONDAY ARE
LIKELY GIVEN THE UNCERTAINTY. FINALLY...AN INCREASE IN LONG PERIOD
SWELLS AND DEEP EASTERLY FETCH WILL LEAD TO AN INCREASE IN THE RIP
CURRENT THREAT ALONG THE BARRIER ISLANDS OVER THE WEEKEND AND INTO
EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 87 77 93 76 93 / 60 20 20 20 30
VICTORIA 91 74 93 74 94 / 50 20 20 10 20
LAREDO 95 75 96 76 95 / 30 20 30 20 30
ALICE 87 74 90 74 92 / 50 20 20 10 30
ROCKPORT 88 78 91 78 90 / 50 20 20 20 20
COTULLA 92 74 95 73 95 / 40 20 20 20 20
KINGSVILLE 87 75 92 75 93 / 50 20 30 20 30
NAVY CORPUS 87 77 90 78 89 / 60 20 20 20 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1011 AM CDT TUE SEP 10 2013
.DISCUSSION...LOWERED TEMPERATURES MAINLY SOUTHEASTERN SECTIONS
AND INCREASED POPS JUST A TAD OVER THE SOUTHERN COASTAL AREAS. RUC
AND HRRR IS SHOWING CONVECTION CONTINUING NEAR THE SOUTHERN
COASTAL AREAS FROM TIME TO TIME TIL EARLY AFTERNOON BEFORE MOST
OF IT PUSHES INLAND. CAN BELIEVE THIS GIVEN RADAR TRENDS/HISTORY
AND OBSERVED/FORECAST SURFACE FORCING. MORNING SOUNDING VERY
WET...WITH LITTLE TO NO CONVECTIVE INHIBITION. THUS...SCATTERED
CONVECTION (MORE NUMEROUS SOUTHERN COASTAL AREAS) SEEMS REASONABLE
THIS MORNING...WITH ACTIVITY PUSHING FARTHER WEST DURING THE
AFTERNOON ONCE ENOUGH DAYTIME HEATING GETS GOING TO GET A SEA-
BREEZE STARTED. OTHER ADJUSTMENTS TO FIRST AND SECOND PERIOD
GRIDS. PRODUCTS ARE OUT. MARINE FORECAST FOR NOW LOOKS REASONABLE.
&&
.PREV DISCUSSION... /ISSUED 643 AM CDT TUE SEP 10 2013/
DISCUSSION...UPDATED FOR THE 12Z AVIATION DISCUSSION.
AVIATION...GENERAL VFR CONDITIONS...WITH BRIEF MVFR CIGS/IFR
VSBYS IN AND AROUND SHOWERS/STORMS. RAIN COVERAGE IS EXPECTED TO
INCREASE...ESPECIALLY ACROSS THE COASTAL PLAINS FROM CRP-ALI-VCT
THROUGH THE LATE MRNG/EARLY AFTN. ISOLATED DEVELOPMENT IS EXPECTED
TO REACH LRD BY MID AFTN...THEREFORE WILL ONLY MAINTAIN VCTS IN
TAFS FOR NOW. THE TROPICAL AIRMASS WILL LEAD TO MOSTLY SHOWER
ACTIVITY...HOWEVER WITH ADDITIONAL HEATING AND WEAK UPPER LEVEL
SUPPORT...THUNDER REMAINS POSSIBLE DURING THE LATE MRNG/AFTN/EVNG
HOURS. ACTIVITY SHOULD WANE FROM EAST TO WEST THROUGH THE EVENING.
GENERAL EASTERLY WINDS 10-15 KTS ARE EXPECTED TO DEVELOP INTO THE
AFTERNOON BEFORE DECOUPLING THIS EVENING.
PREV DISCUSSION... /ISSUED 417 AM CDT TUE SEP 10 2013/
SHORT TERM (TODAY THROUGH WEDNESDAY)...ISOLATED SHOWERS DEVELOPING
ACROSS PORTIONS OF SOUTH TEXAS THIS MORNING DUE TO PWATS NEAR 2
AND SURFACE COASTAL TROUGH SOUTH OF THE AREA WITH WEAK PVA AT H5
ACROSS THE NORTHEASTERN CWA. ADDITIONAL COVERAGE IS EXPECTED TO
DEVELOP THROUGH THE LATE MORNING AND AFTERNOON...WITH HIGHER
CHANCE POPS MAINLY ACROSS THE EASTERN HALF OF THE CWA. AN UPPER
WEAK JET STREAK SHOULD PROVIDE A BIT MORE DIFFLUENT FLOW ACROSS
THE AREA...WHICH MAY LEAD TO A FEW STORMS BECOMING STRONG THIS
AFTERNOON...PARTICULARLY OVER THE COASTAL PLAINS. OTHERWISE...MOST
ACTIVITY SHOULD REMAIN AS SHOWERS WITH GENERAL THUNDER. DUE TO
DEEP TROPICAL MOISTURE...LOCALLY HEAVY RAINFALL CAN BE
EXPERIENCED. RAIN CHANCES WILL THEN TAPER OFF THROUGH THE EVENING
HOURS WITH THE LOSS OF HEATING. THE MID/UPPER LEVEL RIDGE ACROSS
THE EASTERN U.S. WILL SLOWLY SHIFT WESTWARD THROUGH WEDNESDAY WITH
DRIER AIR APPROACHING FROM THE NORTHEAST. HOWEVER PWATS NEAR 1.8
INCHES WILL REMAIN ACROSS THE SOUTH TEXAS...LEADING TO A SLIGHT
CHANCE TO LOW END CHANCE POPS FOR SHOWERS THROUGH WEDNESDAY. AS
FOR TEMPERATURES...HIGHS ARE DEPENDENT ON CLOUD AND RAIN
COVERAGE...HOWEVER WITH BETTER CHANCES FOR RAIN ACROSS THE COASTAL
BEND...WILL MAINTAIN TEMPS IN THE UPPER 80S...WITH LOWER 90S
FARTHER INLAND. SLIGHTLY WARMER TEMPERATURES ARE EXPECTED FOR
WEDNESDAY.
LONG TERM (WEDNESDAY NIGHT THROUGH MONDAY)...MODELS CONTINUE TO
INDICATED MID LEVEL DRYING OCCURS FROM NORTHEAST TO SOUTHWEST
THURSDAY AND FRIDAY...AS THE MID AND UPPER LEVEL RIDGE ACROSS THE
SOUTHEAST U.S. BUILDS BACK TO THE WEST. PRECIPITABLE WATER VALUES
FALL TO 1.6-1.8 INCHES ON THURSDAY AND TO LESS THAN 1.5 INCHES ON
FRIDAY. EXPECT COVERAGE OF SHOWERS AND THUNDERSTORMS TO DECREASE
TO ISOLATED...WITH BEST CHANCES FOR PRECIP MAINLY ACROSS MARINE AND
SOUTHERN AREAS OF THE CWA.
ATTENTION SHIFTS TO THE BAY OF CAMPECHE DURING THE LATTER HALF OF
THE WEEK AND INTO THE WEEKEND. AN AREA OF DISTURBED WEATHER LOCATED
OVER THE NORTHWESTERN CARIBBEAN SEA IS MOVING WESTWARD AND IS
FORECAST TO MOVE ACROSS THE YUCATAN PENINSULA AND INTO THE BAY OF
CAMPECHE BY LATE THURSDAY. MODELS ARE INDICATING AN AREA OF BROAD
LOW PRESSURE TO FORM IN THE BAY OF CAMPECHE...AND NHC HAS
HIGHLIGHTED THIS REGION FOR A HIGH CHANCE OF TROPICAL CYCLONE
DEVELOPMENT DURING THIS TIME. GFS AND ECMWF INDICATE EITHER WAVE OR
CLOSED LOW MOVING WEST-NORTHWEST INTO VERACRUZ OR TAMAULIPAS MEXICO
SUNDAY OR MONDAY. HOWEVER...MODELS ARE INDICATING THE MID AND UPPER
LEVEL RIDGE ACROSS TO BUILD BACK INTO THE SOUTHEAST U.S. DURING THIS
TIME...ALLOWING DEEP SURGE OF TROPICAL MOISTURE NORTH OF THE
POTENTIAL SYSTEM TO POSSIBLY MAKE IT INTO SOUTH TEXAS. HAVE RAISED
POPS INTO THE HIGH END SCATTERED RANGE SUNDAY AND MONDAY AND LOWERED
FORECAST HIGHS. FURTHER FORECAST ADJUSTMENTS SUNDAY AND MONDAY ARE
LIKELY GIVEN THE UNCERTAINTY. FINALLY...AN INCREASE IN LONG PERIOD
SWELLS AND DEEP EASTERLY FETCH WILL LEAD TO AN INCREASE IN THE RIP
CURRENT THREAT ALONG THE BARRIER ISLANDS OVER THE WEEKEND AND INTO
EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 87 77 93 76 93 / 60 20 20 20 30
VICTORIA 91 74 93 74 94 / 50 20 20 10 20
LAREDO 95 75 96 76 95 / 30 20 30 20 30
ALICE 87 74 90 74 92 / 50 20 20 10 30
ROCKPORT 88 78 91 78 90 / 50 20 20 20 20
COTULLA 92 74 95 73 95 / 40 20 20 20 20
KINGSVILLE 87 75 92 75 93 / 50 20 30 20 30
NAVY CORPUS 87 77 90 78 89 / 60 20 20 20 30
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...SHORT TERM
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
337 PM CDT TUE SEP 10 2013
.SHORT TERM...
TONIGHT...FORECAST CONFIDENCE MEDIUM
BROAD 500 MILLIBAR TROUGH SHIFTING EAST FROM THE NORTHERN PLAINS.
WATER VAPOR SHOWS MOISTURE PLUME AND JET MAX FROM SOUTH DAKOTA TO
LAKE SUPERIOR. ANOTHER MOISTURE PLUME LIFTING NNE FROM IOWA. 12Z
4.5KM SPC WRF APPEARS TOO QUICK ON DEVELOPMENT THIS AFTERNOON
ACROSS SW WI. LEANING MORE TOWARDS HRRR SOLUTION WITH DEVELOPMENT
NORTH OF THE CWA AND THEN JUST OOZING INTO CWA LATER THIS EVENING
AND OVERNIGHT. FRONT WILL NOT HAVE MUCH OOMPH INTO SRN WI AS THE
NIGHT GOES ON SO INSTABILITY EVEN LESS THAN THE AFTN 500-1000
J/KG...SO CONFIDENCE NOT GREAT THAT ANYTHING REORGANIZED WILL
SURVIVE TOO DEEP INTO SRN WI.
WEDNESDAY...FORECAST CONFIDENCE MEDIUM
WEAK 850 MILLIBAR CONVERGENCE ALONG WITH 500 MILLIBAR CYCLONIC
FLOW WILL RESULT IN SMALL POPS ACROSS MAINLY THE SOUTHERN CWA. 12Z
NAM IS DRY WHILE OTHER MODELS SHOWING LIGHT QPF. BULK OF ACTIVITY
LOOKS LIKE IT WILL BE FURTHER SOUTH OF THE STATE WITH BETTER
INSTABILITY. 925 TEMPS AVERAGED AMONGST THE MODELS SHOWS 21-23C
WHICH YIELDS QUITE A BIT OF HIGHS IN THE MID 80S.
WEDNESDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE MEDIUM TO HIGH
THE INITIAL...WEAK COLD FRONT WILL SLIDE SWD INTO NRN IL AND NRN
IN BY WED EVENING WITH ANY TSTORM DEVELOPMENT EXPECTED THERE. THE
SECONDARY AND STRONGER COLD FRONT WILL THEN ARRIVE FROM THE NORTH
LATE WED NT. A SHARP CANADIAN UPPER TROUGH WILL ACCOMPANY THE
FRONT AND MOVE INTO THE NRN GRTLKS AND WI BY 12Z THU AND WILL MOVE
EAST OF WI BY FRI. LOW LEVEL INSTABILITY VIA COLD AIR ALOFT MAY
LEAD TO SCT SHOWERS OVER THE ERN CWA THU INTO THU EVENING. A NNELY
1000-850 MB FLOW AND LAKE TO 850 MB TEMP DIFFERENCES OF 13C OR
GREATER MAY CONTRIBUTE TO THE SHOWER POTENTIAL OVER THE LAKE
COUNTIES AS WELL. THE COLD AND DRY AIR ADVECTION TO SLOW DOWN BY
THU NT WITH MORE SUN THEN EXPECTED FOR FRI AS THE CANADIAN HIGH
CENTERS OVER WI. EXPECTED 925 MB TEMPS OF THE MID TO UPPER TEENS
CELSIUS FOR THU AND AROUND 10C FOR FRI...WILL YIELD HIGHS IN THE
MID 70S FOR THU AND LOWER TO MID 60S FOR FRI.
.LONG TERM...
SATURDAY THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM
THE MAIN POLAR JET STREAM WILL REMAIN IN CANADA WITH ANOTHER
STRONG UPPER TROUGH AND LOW PRESSURE AREA MOVING ACROSS CANADA. SWLY
WINDS AND WARMER TEMPS WILL RETURN FOR SAT AND SUN OVER SRN WI
AHEAD OF THE TRAILING CANADIAN COLD FRONT THAT WILL PASS ON
SUNDAY. ONLY SMALL CHANCES FOR PCPN WITH THE FRONT. CANADIAN HIGH
PRESSURE WILL THEN TRACK FROM THE NRN GRTLKS SUN NT TO THE ERN
GRTLKS FOR MON AND POSSIBLY TUE. A DRY ELY FLOW WILL PREVAIL OVER
THE AREA WITH PLEASANT AND NEAR TO SLIGHTLY BELOW NORMAL TEMPS.
&&
.AVIATION/00Z TAFS/...VFR SKC INTO THE EVENING HOURS FOR TAF SITES.
EXPECT MID CLOUDS TO INCREASE TONIGHT AS FRONTAL BOUNDARY SAGS SOUTH
AND INFLUENCE OF UPPER JET ENHANCES VERTICAL MOTION. LATEST HRRR
KEEPS CONVECTION NORTH OF TAF SITES THROUGH 05Z. WILL BRING SOME
SHRA/TSRA INTO THE AREA LATER IN THE NIGHT. THE NAM IS THE ONLY
MODEL NOT SHOWING PRECIP WEDNESDAY. WARY THAT SOME SHRA WILL
LINGER THOUGH FORCING NEAR NIL ONCE LOW LEVEL BOUNDARY SAGS SOUTH.
&&
.MARINE...A FEW SOUTHWEST WIND GUSTS EXCEEDING CRITERIA SO WILL
LEAVE SMALL CRAFT GOING UNTIL 7 PM.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LMZ643>646.
&&
$$
TONIGHT/WEDNESDAY AND AVIATION/MARINE...COLLAR
WEDNESDAY NIGHT THROUGH TUESDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
244 PM CDT TUE SEP 10 2013
.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 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1248 PM CDT TUE SEP 10 2013
AT 10.18Z...A COLD FRONT EXTENDED FROM JUST SOUTH OF MARSHFIELD
WISCONSIN TO AUSTIN MINNESOTA. BEHIND THIS FRONT...THERE IS A BROKEN
DECK OF 10-15K OF CLOUDS. FURTHER TO THE NORTHWEST...ANOTHER COLD
FRONT EXTENDED FROM DULUTH TO REDWOOD FALLS. AHEAD OF THIS FRONT
THERE IS A NARROW BAND OF SHOWERS. 10.12Z MESO MODELS SUGGEST THAT
THE FRONTOGENETIC FORCING ALONG THE NORTHERN FRONT WILL
DRAMATICALLY WEAKEN THIS AFTERNOON AND INCREASE ALONG THE SOUTHERN
FRONT. AS THIS OCCURS...THERE WILL BE THE POTENTIAL THAT BOTH TAF
SITES WILL MISS OUT ON THE SHOWERS. FELT CONFIDENT TO REMOVE THE
SHOWERS AT KRST...AND TIGHTENED THE TIME PERIOD OF THEIR
OCCURRENCE AT KLSE TO BETWEEN 11.04Z AND 11.08Z. BETWEEN 11.11Z AND
11.14Z...THE 10-15K FOOT DECK WILL LIKELY BECOME SCATTERED AS THE
FRONT CONTINUES TO PUSH AWAY FROM THE REGION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....BOYNE
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1239 AM CDT TUE SEP 10 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 403 PM CDT MON SEP 9 2013
PLENTY OF QUESTIONS REMAIN REGARDING THE CHANCE FOR CONVECTION
TODAY. THERE WERE EVEN A FEW SHOWERS THAT WERE ON THEIR WAY OUT
OF THE AREA AT 20Z THAT APPEAR TO HAVE DEVELOPED ALONG A BOUNDARY
FROM THE THUNDERSTORM COMPLEX THAT MOVED ACROSS MINNESOTA
OVERNIGHT. THERE IS PLENTY OF INSTABILITY...MESOANALYSIS HAD
MUCAPES MAINLY IN THE 1000-3000J/KG RANGE EXCEPT NEAR THE UPPER
MICHIGAN BORDER WHERE THEY WERE IN THE 500-1000J/KG RANGE AT 20Z.
WEAKEST CIN WAS FROM NORTH CENTRAL AND NORTHEAST WISCONSIN
SOUTHWEST INTO EASTERN IOWA...BUT STRONG WARM ADVECTION ALOFT
CONTINUED TO HAMPER CONVECTIVE DEVELOPMENT ACROSS THE AREA.
LIGHT EAST OR SOUTH WINDS THIS MORNING HAVE BECOME SOUTHERLY AND
INCREASED DURING THE DAY. A WARM FRONT WAS MOVING NORTHEAST INTO
CENTRAL WISCONSIN THIS AFTERNOON AND WAS FORECAST TO MAKE IT TO
NEAR THE WISCONSIN/UPPER MICHIGAN BORDER BY 00Z. THIS MAY BE A
BIT TOO QUICK BASED ON ITS SPEED DURING THE DAY. THE WESTERLY FLOW
OF WARM AIR ALOFT WAS HELPING TO PRODUCE STRONG LOW-LEVEL AND
DEEP-LAYER SHEAR...ESPECIALLY ACROSS NORTHERN WISCONSIN AND UPPER
MICHIGAN.
STORMS MAY FIRE AS THE SURFACE LOW IN EASTERN MINNESOTA MOVES
ACROSS NORTHERN WISCONSIN LATER TONIGHT. EXPERIMENTAL COMPOSITE
REFLECTIVITY FROM THE 18Z HRRR DID NOT REALLY SHOW ANYTHING ACROSS
THE AREA...THOUGH IT DID SUGGEST CONVECTIVE ACTIVITY IN
CENTRAL/SOUTHERN WISCONSIN TODAY THAT DID NOT DEVELOP. IF STORMS
DO DEVELOP...THEY COULD PRODUCE LARGE HAIL AND DAMAGING WINDS. AN
ISOLATED TORNADO WAS EVEN MENTIONED BY SPC IN THEIR DAY ONE
OUTLOOK...WITH STORMS DEVELOPING INTO A FORWARD PROPAGATING MCS
WITH LLJ DEVELOPMENT...RESULTING IN MAINLY A DAMAGING WIND EVENT
THEREAFTER.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 403 PM CDT MON SEP 9 2013
LITTLE CHANGE IN SCENARIO FROM PAST FEW DAYS WITH AREA
TRANSITIONING INTO A NORTHWEST FLOW REGIME BY WED. MODELS IN
SIMILAR AGREEMENT THROUGH THE END OF THE WORK WEEK...THEN BEGIN
TO DIFFER AS MORE ZONAL PATTERN BUILDS IN. PRECIPITATION CHANCES
FIRST PART OF FORECAST MAIN CONCERNS.
WEAK COLD FRONT WILL SLOWLY SAG SOUTH THROUGH CWA ON TUE...THEN
SOUTH OF THE REGION TUESDAY NIGHT. MODELS TRENDING DRY THROUGH AM
WITH LIMITED CONVERGENCE ALONG FRONT AND NO UPPER SUPPORT. MODELS
A BIT MORE BULLISH ON QPF CHANCES LATE TUE AFTN AND OVERNIGHT...AS
WEAK WAVE MOVES NORTHEAST ALONG FRONT IN RESPONSE TO SHORT WAVE
TROF AND SOME JET ENERGY MOVING THROUGH. BUMPED POPS UP TO LIKELY
IN THE FAR SOUTH. PW`S STILL IN THE 1.5 TO 2 INCH RANGE WITH HEAVY
RAIN BIGGEST THREAT.
POSSIBILITY OF SHOWERS CONTINUES INTO THU AS UPPER DISTURBANCES
DROP SOUTHEAST THROUGH THE WESTERN LAKES. LINGERING LOW LEVEL
MOISTURE TO LEAD TO BETTER INSTABILITY AND CHANCE OF PCPN ON WED BUT
LATEST RUNS SHOW RATHER STRONG SYSTEM DROPPING THROUGH ON THU.
HAVE STAYED DRY THU ATTM GIVEN MOISTURE AND TIMING CONCERNS.
HIGH PRESSURE BUILDS IN LATER THU FOR DRY CONDITIONS THROUGH SAT.
HIGH TO SHIFT EAST OF AREA SAT NIGHT ALLOWING RETURN FLOW TO
DEVELOP. THIS WILL BRING A GOOD CHANCE OF SHOWERS AND ISOLD TSTMS
TO THE REGION SAT NIGHT INTO SUN.
COLDER AIR MOVES IN BEHIND STRONG COLD FRONT ON WED WITH
TEMPERATURES FALLING BACK TO NORMAL OR BELOW FOR REMAINDER OF
PERIOD. COOLEST TEMPERATURES EXPECTED FRI WITH COOL NORTHEAST
FLOW.
MAINTAINED SMALL CHANCE FOR LAKE EFFECT SHOWERS ON THU...THOUGH
WINDS MARGINAL. WILL LIKELY SEE LAKE CLOUDS AT TIMES OVER THE
NORTH THOUGH CAUSING HAVOC WITH LOW TEMP FORECASTS.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1238 AM CDT TUE SEP 10 2013
IFR/LIFR CIGS VSBYS WILL LINGER ACROSS THE NORTH AHEAD
OF WARM FRONT ACROSS NORTHERN WISCONSIN. MAINLY VFR CONDITIONS
WITH PATCHY MVFR VSBYS DUE TO HAZE ELSEWHERE. SOUTH SURFACE WINDS
AROUND 10 KNOTS WITH NEAR 40 KNOTS WINDS AT 2000 FEET WILL PRODUCE
LLWS CONDITIONS THIS MORNING.
SCATTERED CONVECTION ACROSS THE NORTH WILL COMBINE WITH THE
IFR/LIFR CONDITIONS THIS MORNING. SCATTERED CONVECTION WILL BE ON
THE INCREASE AGAIN LATER TODAY INTO TONIGHT AS A COLD FRONT DROPS
SOUTH OVER THE STATE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MG
LONG TERM......TE
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
158 AM MDT THU SEP 12 2013
.UPDATE...
ISSUED AT 157 AM MDT THU SEP 12 2013
PUSHED BACK THE START TIME OF FLASH FLOOD WATCH TO THE CURRENT
TIME...SINCE HEAVY RAIN IS OCCURRING NOW.
UPDATE ISSUED AT 1144 PM MDT WED SEP 11 2013
QUICK UPDATE TO ALLOW THE FLASH FLOOD WATCH FOR THIS EVENING TO
EXPIRE. ALSO BROUGHT IN LATEST OBS DATA AS WELL AS SATELLITE AND
RADAR TRENDS. MOORE
&&
.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 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1144 PM MDT WED SEP 11 2013
KCOS AND KPUB...ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
EXPECTED ALONG THE I25 CORRIDOR TOMORROW AFTN AND EVE. CURRENT
CONVECTION IS TRACKING TO THE N-NW BUT IS STARTING TO DIMINISH IN
INTENSITY AND AREAL COVERAGE. MVFR CEILINGS EXPECTED
OVERNIGHT...WITH A CONTINUED THREAT OF HEAVY RAIN.
KALS...MVFR CEILINGS EXPECTED OVERNIGHT WITH ENHANCED LOW LEVEL
MOISTURE PERSISTING. SHOWERS AND THUNDERSTORMS WILL DEVELOP BY
LATE MORNING AS A DISTURBANCE MOVES INTO THE REGION.
&&
.HYDROLOGY...
ISSUED AT 557 PM MDT WED SEP 11 2013
FROM THE MOTION OF THE MOSAIC RADAR IMAGERY...ANOTHER VORTMAX IS
LIKELY LOCATED OVER PUEBLO COUNTY. THIS ONE DOES NOT APPEAR TO BE
AS WELL DEFINED AS THIS MORNINGS VORT MAX. NONETHELESS...WE WILL
CAREFULLY BE WATCHING FOR INCREASING ECHOES OVER THE WALDO BURN
SCAR. HRRR HAS BEEN TRYING TO DISSIPATE THIS AREA OF RAIN FOR THE
LAST FEW RUNS AND IT HAS NOT HAPPENED YET. THE GROUND IS SATURATED
OVER THE BURN SCAR AND IT WILL NOT TAKE TOO MUCH TO CAUSE
PROBLEMS. /HODANISH
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING FOR COZ081-084-085.
&&
$$
UPDATE...28
SHORT TERM...PGW
LONG TERM...MW
AVIATION...MOORE
HYDROLOGY...HODANISH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1149 PM MDT WED SEP 11 2013
.UPDATE...
ISSUED AT 1144 PM MDT WED SEP 11 2013
QUICK UPDATE TO ALLOW THE FLASH FLOOD WATCH FOR THIS EVENING TO
EXPIRE. ALSO BROUGHT IN LATEST OBS DATA AS WELL AS SATELLITE AND
RADAR TRENDS. MOORE
&&
.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 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1144 PM MDT WED SEP 11 2013
KCOS AND KPUB...ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
EXPECTED ALONG THE I25 CORRIDOR TOMORROW AFTN AND EVE. CURRENT
CONVECTION IS TRACKING TO THE N-NW BUT IS STARTING TO DIMINISH IN
INTENSITY AND AREAL COVERAGE. MVFR CEILINGS EXPECTED
OVERNIGHT...WITH A CONTINUED THREAT OF HEAVY RAIN.
KALS...MVFR CEILINGS EXPECTED OVERNIGHT WITH ENHANCED LOW LEVEL
MOISTURE PERSISTING. SHOWERS AND THUNDERSTORMS WILL DEVELOP BY
LATE MORNING AS A DISTURBANCE MOVES INTO THE REGION.
&&
.HYDROLOGY...
ISSUED AT 557 PM MDT WED SEP 11 2013
FROM THE MOTION OF THE MOSAIC RADAR IMAGERY...ANOTHER VORTMAX IS
LIKELY LOCATED OVER PUEBLO COUNTY. THIS ONE DOES NOT APPEAR TO BE
AS WELL DEFINED AS THIS MORNINGS VORT MAX. NONETHELESS...WE WILL
CAREFULLY BE WATCHING FOR INCREASING ECHOES OVER THE WALDO BURN
SCAR. HRRR HAS BEEN TRYING TO DISSIPATE THIS AREA OF RAIN FOR THE
LAST FEW RUNS AND IT HAS NOT HAPPENED YET. THE GROUND IS SATURATED
OVER THE BURN SCAR AND IT WILL NOT TAKE TOO MUCH TO CAUSE
PROBLEMS. /HODANISH
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY
EVENING FOR COZ081-084-085.
&&
$$
UPDATE...MOORE
SHORT TERM...PGW
LONG TERM...MW
AVIATION...MOORE
HYDROLOGY...HODANISH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1042 PM MDT WED SEP 11 2013
.UPDATE...
ISSUED AT 820 PM MDT WED SEP 11 2013
SHOWERS AND THUNDERSTORMS ALMOST NON-EXISTENT ACROSS SOUTHEAST
UTAH AND SOUTHWEST COLORADO THIS EVENING. MID-LEVEL SUBSIDENCE
INVERSION APPARENT IN 00Z/THU KGJT SOUNDING COMBINED WITH DIURNAL
COOLING LIKELY TO KEEP SHOWERS AND THUNDERSTORMS IN CHECK DURING
MUCH OF THE REMAINDER OF THE NIGHT. THEREFORE...CANCELED THE FLASH
FLOOD WATCH A BIT EARLY. AN AREA OF SHOWERS WITH A FEW EMBEDDED
THUNDERSTORMS CONTINUED OVER PORTIONS OF THE FLAT TOPS AND GORE
RANGE. EXPECT THIS ACTIVITY WILL CONTINUE TO WEAKEN AS IT MOVES
SLOWLY NORTH-NORTHWEST THROUGH THE REMAINDER OF THE EVENING.
&&
.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 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1042 PM MDT WED SEP 11 2013
ISOLATED SHOWERS AND EMBEDDED THUNDERSTORMS ARE EXPECTED TO
CONTINUE ACROSS THE FORECAST AREA DURING THE REMAINDER OF THE
NIGHT. THIS ACTIVITY IS EXPECTED TO BRING LOCALIZED MOUNTAIN
OBSCURATION AND POSSIBLY BRIEF MVFR VSBY IN HEAVY RAIN. DESPITE
SHOWER ACTIVITY...MOST AREAS WILL HAVE VFR CONDITIONS DURING THE
REMAINDER OF THE NIGHT THROUGH 18Z. SHOWERS AND THUNDERSTORMS WILL
INCREASE IN COVERAGE AND INTENSITY AFTER 18Z AND WILL CONTINUE
THROUGH 03Z FRIDAY BEFORE DECREASING TOWARDS MIDNIGHT. AIRPORTS
ACROSS THE REGION WILL FACE A 30 TO 50 PERCENT CHANCE OF STORM
CELLS MOVING OVERHEAD POSSIBLY RESULTING IN BRIEF MVFR CONDITIONS
ALONG WITH WIND GUSTS TO 30 MPH DURING THE AFTERNOON AND EARLY
EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
UPDATE...NL
SHORT TERM...TGR
LONG TERM...JAM
AVIATION...NL
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
249 AM CDT THU SEP 12 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 DOWN BURST 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 06Z...
TRENDS IN WIND DIRECTION...SPEED...GUSTINESS THROUGH THE DAYTIME
AND TONIGHT.
MVFR LAKE EFFECT STRATOCUMULUS TONIGHT.
SLIGHT CHANCE OF LIGHT LAKE EFFECT SHOWERS FOR A PERIOD OF TIME
LATE THIS EVENING INTO THE OVERNIGHT.
TRS
//DISCUSSION...UPDATED 06Z...
MODELS HAVE A GOOD HANDLE ON OVERALL SYNOPTIC PATTERN BUT NOT IN
HANDLING OF MESOSCALE FEATURES. SO...WHILE HAVE MODERATE TO HIGH
CONFIDENCE IN OVERALL TRENDS ACROSS THE AREA FOR THE REST OF THE
NIGHT AND THROUGH THE DAY...CONFIDENCE IS MODERATE TO LOW IN
SPECIFIC DETAILS SUCH AS EXACT WIND DIRECTIONS...SPEEDS AND GUSTS
AND TIMING OF SUCH.
MID LEVEL SHORT WAVE TROUGH WAS CURRENTLY MOVING EAST OVER THE
IMMEDIATE AREA...WITH THE RESULT BEING THE CONTINUED SLOW
SOUTHWARD DRIFT OF THE BAND OF SHOWERS AND THUNDERSTORMS
EXTENDING ACROSS WEST CENTRAL TO NORTHERN IN ALONG THE ORIGINAL
WEAK COLD FRONT THAT CONVECTIVE OUTFLOW HAS CONTRIBUTED TO
HELPING MAINTAIN ITS EXISTENCE RATHER THAT TOTALLY WASHING OUT.
THREAT OF ANY SHOWERS OF THUNDERSHOWERS AT THE LOCAL TERMINALS
NIL OVERNIGHT THE REST OF THE NIGHT...EVEN AT KGYY WHERE A FEW
SHOWERS THAT DEVELOPED IN SOUTHERN COOK COUNTY AROUND 05Z HAD
QUICKLY PASSED EAST OF THE AIRFIELD BY AROUND 0530Z PER LOCAL
RADARS.
THIS SHORT WAVE TROUGH IS PROGGED REACH NORTH CENTRAL IN BY 09Z
AND WITH SUBSTANTIAL SUBSIDENCE IN THE WAKE OF THE SHORT WAVE
TROUGH HAVE HIGH CONFIDENCE THAT THE BACK EDGE OF THE MID LEVEL
CLOUD DECK WILL CONTINUE TO PUSH SOUTH OF THE ALL THE
TERMINALS WITH EVEN KGYY LOSING THEIR CEILING BY 08Z.
WHILE MODEL PROGS AND THEIR MOS GUIDANCE ARE INDICATING A VEERING
OF THE SURFACE WINDS FROM WEST-NORTHWEST TO NORTHWEST OR NORTH-
NORTHWEST BETWEEN 06Z AND 12Z...WHICH IS WHAT ONE WOULD TYPICALLY
EXPECT WITH THE PASSAGE OF A SHORT WAVE TROUGH...THE SURFACE OBS
LOCALLY AND UPSTREAM ARE NOT PARTICULARLY SUPPORTIVE OF THIS
IDEA. THE FACT THAT THE PRESSURE GRADIENT ACROSS THE REGION IS
STILL QUITE WEAK AND SURFACE DECOUPLING HAS OCCURRED OVER MUCH OF
THE REGION WINDS REPORTED IN METARS...IF THERE IS ANY WIND...IS
RESPONDING TO LOCAL INFLUENCES RATHER THAT LARGER SCALE SYNOPTIC
CONDITIONS.
A CONTRIBUTING FACTOR IS THAT ANOTHER SHORT WAVE HAS BEEN DROPPING
SOUTHEASTWARD INTO THE MEAN UPPER TOUGH...WHOSE AXIS EXTENDED
FROM HUDSON BAY ACROSS ONTARIO AND THE UPPER MIDWEST TO THE MID MS
VALLEY LATE THIS WEDNESDAY NIGHT. HIGHER RESOLUTION MODELS DO
PICK UP ON THIS FEATURE AND HAVE HAVE ITS AXIS BY 12Z EXTENDING
FROM THE WESTERN U.P. OF MI SOUTHWESTWARD ACROSS WI TO FAR
SOUTHEASTERN MN...AND FURTHER ADVANCING IT TO FAR SOUTHERN LAKE MI
AND NORTHEASTERN IL MID TO LATE THIS AFTERNOON.
SYNOPTICALLY ONE WOULD EXPECT A BACKING-VEERING SIGNATURE TO BE
SEEN IN THE THE LOW LEVEL FLOW AS THE MID LEVEL TROUGH APPROACHES
AND AND THEN PASSES BY THE LOCAL AREA AND WITH THE ERRORS IN THE
SHORT TERM FORECASTS OF THE MODELS HAVE A STRONG SUSPICION THAT
THEIR INDICATED TREND OF A CONTINUED VEERING TO OUT OF THE NORTH-
NORTHWEST TO NORTH BY EARLY TO MID MORNING...AND TO OUT OF THE
NORTH-NORTHEAST OR EVEN A SOLID NORTHEAST DIRECTION BY LATE
AFTERNOON-EARLY EVENING IS IN ERROR. BELIEVE THAT THE SIGNIFICANT
VEERING WILL NOT OCCUR UNTIL THE UPSTREAM SHORT WAVE TROUGH PASSES
BY LATE MORNING-MIDDAY.
DO ANTICIPATE AN INCREASE IN WIND SPEED AND THE BEGINNING OF SOME
GUSTINESS AS THE AFTERNOON PROGRESS BUT NORTH-NORTHEAST WINDS ARE
NOT EXPECTED TO GUST INTO THE LOWER AND MID 20KT RANGE UNTIL LATE
AFTERNOON AND THIS EVENING AS THE STRONG LOW LEVEL COLD AIR
ADVECTION KICKS IN FOLLOWING THE UPSTREAM SHORT WAVE PASSAGE LATER
TODAY.
WHILE NOT EXTENSIVE IN COVERAGE THERE IS SOME CLOUDS WITH 060-100
AGL BASES MOVING ACROSS CENTRAL WI AND EXPECT THE TREND TO
CONTINUE WITH A MID LEVEL DECK ARRIVING LOCALLY MID-LATE MORNING
AS THE SHORT WAVE TROUGH APPROACHES THOUGH WITH THE DRYING OF THE
LOWER LAYERS WOULD NOT EXPECT MORE THAN SOME VIRGA OR A SPRINKLE
OF TWO AT THE LOCAL TERMINALS.
NEXT ITEM THAT NEEDS TO BE CONSIDERED IS THE POTENTIAL FOR LAKE
EFFECT CLOUDS...AND POSSIBLY A FEW LAKE EFFECT SHOWERS ADVANCING
FAR ENOUGH INLAND TO REACH KMDW AND KORD AS THIS EVENING AND INTO
THE OVERNIGHT HOURS. BASED ON PROGGED STRONG LOW LEVEL COOLING
COUPLES WITH WINDS TO VEER A BIT NORTH OUT OF THE NORTH-NORTHEAST
AND NORTHEAST AS YET ANOTHER SHORT WAVE...CURRENTLY MOVING QUICKLY
SOUTHEASTWARD OVER NORTHERN MANITOBA...CROSSES THE UPPER MIDWEST
DURING THE AFTERNOON AND EVENING. THIS WILL REINFORCE THE ALREADY
ONGOING LOW LEVEL COLD AIR ADVECTION DOWN THE LENGTH OF THE LAKE.
SUSPECT A MID LAKE BAND OF SHOWERS TO DEVELOP NORTH TO SOUTH DOWN
LAKE MI THIS EVENING...WITH THE TAIL END OF THE BAND TURNING
SOUTH-SOUTHWESTWARD OR SOUTHWESTWARD TO ACROSS FAR NORTHWESTERN
IN AS WELL FAR NORTHEASTERN IL.
KGYY AND KMDW TO HAVE HIGHER CHANCES OF MVFR LAKE EFFECT CLOUD
CEILINGS AND POSSIBLE LAKE EFFECT SHOWERS DURING THE LATE EVENING
AND OVERNIGHT HOURS WHILE IT APPEARS THAT THE LOW LEVEL FLOW DOES
NOT VEER QUITE FAR ENOUGH TO OUT OF THE THE NORTHEAST DURING THIS
TIME AS THE CENTER OF THE LARGE COOL CANADIAN ANTICYCLONE SETTLES
OVER THE NORTHERN GREAT LAKES DURING THE NIGHT BUT THERE THERE ARE
SOME INDICATIONS THAT THE WESTERN EDGE OF THE LAKE EFFECT CLOUDS
WILL MOVE TO KORD THOUGH AND MVFR WOULD SEEN TO BE A TEMPO RATHER
THAT A PREVAILING CONDITION. A RELAXING PRESSURE GRADIENT DURING
THE LATE NIGHT AND EXPECTED MID LAKE CONVERGENCE ARE EXPECTED TO
RESULT IN A BACKING OF THE LOW LEVEL SOMEWHAT OVERNIGHT. THIS IS
EXPECTED TO MOVE THE WESTERN EDGE OF ANY LAKE EFFECT CLOUDS BACK
TOWARDS THE EAST...TO EXTREME SOUTHEASTERN COOK COUNT AND
SOUTHWARD NEAR/ALONG THE IL-IN BORDER. BY PRE-DAWN FRIDAY.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
MODERATE TO HIGH CONFIDENCE IN OVERALL TRENDS FOR THE REST OF THE
NIGHT AND THROUGH THE DAY.
MODERATE TO LOW CONFIDENCE IN SPECIFIC DETAILS SUCH AS EXACT WIND
DIRECTIONS...SPEEDS AND GUSTS AND TIMING OF SUCH FROM LATE MORNING
THROUGH TONIGHT.
MODERATE TO LOW CONFIDENCE IS EXACTLY HOW FAR WESTWARD LAKE
EFFECT CLOUDS WILL REACH LATER EVENING INTO THE OVERNIGHT.
TRS
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY...MVFR POSSIBLE EARLY...THEN DRY/VFR.
* SATURDAY...DRY/VFR.
* SUNDAY...CHANCE OF TSRA.
* MONDAY...DRY/VFR.
* TUESDAY...SLIGHT CHANCE OF TSRA.
&&
.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 AIR MASS
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.
&&
$$
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CANNOT BE GUARANTEED DUE TO THE NATURE OF THE INTERNET.
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
157 AM EDT THU SEP 12 2013
.SYNOPSIS...
ISSUED AT 1040 PM EDT WED SEP 11 2013
A COLD FRONT WILL SAG SLOWLY SOUTHWARD THROUGH THE GREAT LAKES
TONIGHT. THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS
THROUGH THE NIGHT AHEAD OF THIS FRONT. 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 WEDNESDAY.
&&
.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 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 148 AM EDT THU SEP 12 2013
PRIMARILY VFR MET CONDS...SAVE FOR POTENTIAL FOR MARGINALLY WEAK
CONVECTION UPSTREAM OF KFWA. AS BLYR CONTS TO STABILIZE DO NOT
FORSEE TOO GREAT CHANCE FOR TSRA AT AIRFIELD PROPER AND WL CONT TO
OMIT. ARDENT DRAW OF SIGNIFICANTLY DRIER/COOLER POST FRONTAL
AIRMASS TO AFFORD SOME MINOR GUSTS MIDDAY. ASSERTIVE DIG OF
UPSTREAM ENERGY CURRENTLY OVER MANITOBA INTO EWD PROGRESSING
LONGWAVE TROF COULD AFFORD SOME INCREASE IN CLOUD COVER LATE IN
THE FORECAST PERIOD...THOUGH EXTREMELY DRY SUBCLOUD LAYER AND
OVERALL DEARTH OF MOISTURE SHOULD MAINTAIN VFR MET CONDS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT FROM 10 AM CDT THIS MORNING THROUGH LATE
FRIDAY NIGHT FOR INZ003.
MI...BEACH HAZARDS STATEMENT FROM 11 AM EDT THIS MORNING THROUGH LATE
FRIDAY NIGHT FOR MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 11 AM EDT THIS MORNING TO 6 AM EDT
SATURDAY FOR LMZ043-046.
&&
$$
SYNOPSIS...FISHER
SHORT TERM...FISHER
LONG TERM...T
AVIATION...MURPHY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
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AREA FORECAST DISCUSSION
NWS WICHITA KS
1148 PM CDT WED SEP 11 2013
.UPDATE...
ISSUED AT 1142 PM CDT WED SEP 11 2013
UPDATED THE AVIATION SECTION BELOW FOR THE 06Z TAFS.
&&
UPDATE ISSUED AT 651 PM CDT WED SEP 11 2013
UPDATED THE AVIATION SECTION BELOW FOR THE 00Z TAFS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 320 PM CDT WED SEP 11 2013
SURFACE AND RADAR DATA SHOWS A SHOWERS AND A FEW THUNDERSTORMS
OVER THE HIGH PLAINS AND ALONG A QUASI-STATIONARY FRONT WHICH
EXTENDS ACROSS SOUTHERN NEBRASKA...SOUTHERN IOWA AND SOUTHERN
WISCONSIN.
CONVECTION CONTINUES TO BE THE MAIN SHORT TERM FORECAST PROBLEM.
AT 20Z...CONVECTION HAD DEVELOPED WESTERN AND CENTRAL KANSAS. THIS
IS IN THE MOISTURE PLUME SHOWN ON WATER VAPOR IMAGERY AND NEAR
WHAT THE HRRR RUNS HAVE SHOWN FOR MUCH OF THE DAY. THIS HAS BEEN
INITIALIZED INTO THE FORECAST GRIDS. EXPECT THE FRONT TO CONVECT
AS WELL AS CONVERGENCE AND INSTABILITY INCREASE AND THE CAP
DECREASES THIS EVENING. DEEP LAYER SHEAR CONTINUES TO REMAIN QUITE
UNFAVORABLE FOR ORGANIZED SEVERE WEATHER.
THE FRONT WILL MOVE SOUTH AS A COLD FRONT LATER THIS EVENING AND
STORMS ALONG IT INCREASE. WE CONTINUE TO INCREASE PRECIPITATION
CHANCES IN THE FORECAST AS MOISTURE AND FORCING FIELDS LOOK MORE
FAVORABLE.
AS THE FRONT MOVES SOUTH...THEN SOUTHWEST THROUGH THE FORECAST
AREA...PRECIPITATION CONTINUES ACROSS MUCH OF THE AREA
THURSDAY...AND IS THEN CONFINED ALONG THE FRONT THURSDAY NIGHT.
THIS SHOULD BE MAINLY WEST OF INTERSTATE 135. HIGH PRESSURE BUILDS
INTO THE REGION FRIDAY...FOR THE COOLEST DAY IN A WHILE ACROSS
THE REGION.
COOK
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT WED SEP 11 2013
THE RIDGE OVER THE WESTERN UNITED STATES MOVES ACROSS THE REGION
DURING THE TIME FRAME. AS THIS OCCURS...THUNDERSTORMS ARE POSSIBLE
INTO EARLY THIS COMING WEEK UNTIL THE WARM FRONT /THE COLD FRONT
THAT MOVES THOUGH THE AREA RETURNING NORTH AS A WARM FRONT/ MOVES
THROUGH. BY THE MIDDLE OF NEXT WEEK...THE RIDGING SHOULD CENTER
ITSELF ACROSS THE REGION...AS INDICATED BY THE MEAN OF THE 11.00Z
NAEFS. THIS WILL BRING WARM SOUTHERLY WINDS AND TEMPERATURES WELL
ABOVE NORMAL BACK INTO THE REGION.
COOK
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1142 PM CDT WED SEP 11 2013
A FAIRLY WET NIGHT ANTICIPATED IN THE FORM OF SCATTERED SHOWERS
AND EMBEDDED THUNDERSTORMS...ESPECIALLY FOR SLN AND RSL...AS A
FRONT SLOWLY MOVES SOUTH ACROSS THE REGION...INTERACTING WITH
DEEP/RICH MOISTURE IN PLACE. LESS NUMEROUS ACTIVITY WILL AFFECT
HUT...ICT AND POSSIBLY CNU LATER TONIGHT. SCATTERED
SHOWERS/THUNDERSTORMS WILL LIKELY CONTINUE TO FESTER ACROSS THE
REGION THROUGH THURSDAY...ALTHOUGH FOCUS SHOULD GRADUALLY SHIFT
INTO SOUTHERN KS TOWARD DAY`S END.
ADK
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 69 83 65 79 / 30 50 30 20
HUTCHINSON 68 81 63 77 / 40 60 30 30
NEWTON 68 82 63 78 / 30 50 30 20
ELDORADO 70 84 64 80 / 30 40 20 10
WINFIELD-KWLD 70 86 67 80 / 20 30 30 20
RUSSELL 67 78 61 73 / 60 70 40 40
GREAT BEND 66 78 62 74 / 50 70 50 40
SALINA 68 83 63 78 / 50 60 30 20
MCPHERSON 67 82 63 77 / 40 60 30 20
COFFEYVILLE 70 88 67 82 / 10 20 20 10
CHANUTE 69 86 64 81 / 20 40 10 10
IOLA 70 85 63 80 / 30 40 10 10
PARSONS-KPPF 69 88 65 82 / 20 30 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
359 AM EDT THU SEP 12 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY...MOVING
THROUGH DURING THE LATE AFTERNOON AND EVENING. CANADIAN HIGH
PRESSURE WILL BUILD INTO THE AREA LATE IN THE WEEK AND INTO THE
WEEKEND. A WEAK COLD FRONT IS EXPECTED TO MOVE THROUGH ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
QUITE AN ENTERTAINING WATER VAPOR LOOP OF THE CONUS WITH THREE NEAR
CONSECUTIVE UPPER LOWS EFFECTIVELY SITTING/SPINNING IN PLACE...W/ A
NUMBER OF OTHER DYNAMIC FEATURES PASSING BY TO THE NORTH AND SOUTH.
THE FIRST IS A LARGE UPPER LOW OVER THE INNER-MTN WEST/ROCKIES. TWO
MIRROR-IMAGE SMALLER UPPER LOWS ARE ON OPPOSITE SIDES OF THE
SOUTHEAST.
EACH OF THESE FEATURES ARE KEY IN THE SET-UP FOR THE MID-ATLC`S WX
TODAY. A CORRIDOR OF MONSOON MOISTURE FROM THE PACIFIC IS BEING
DRAWN UP BETWEEN THE UPPER LOW OVER THE DESERT SW AND TX. THE JET
STREAM IS BRINGING IN A DEEPENING UPPER TROUGH FROM CNTRL CANADA AND
SPREADING OUT THE MOISTURE TOWARD THE EAST. THE SRN ATLC UPPER LOW
IS KEEPING THE MOISTURE LOCKED-IN BENEATH THE EXITING BUT LARGE
UPPER RIDGE MOVING OFF THE COAST.
HIGHS WILL STILL REACH THE U80S AND A FEW L90S ALONG W/ EXTENSIVE
L70S DEWPOINTS. STILL A HOT/HUMID DAY EXPECTED BUT INCREASING CLOUDS
AND PRECIP LATER THIS AFTN WILL BRING SOME RELIEF EARLIER IN THE
DAY. AFTER ONLY REACHING THE M70S FOR CURRENT OVERNIGHT
TEMPS...WE`LL SEE A GOOD INCREASE BACK INTO THE 80S AFTER SUNRISE
THIS MRNG.
IN TERMS OF INSTABILITY/CONVECTIVE POTENTIAL TODAY...WE ALREADY HAVE
A WEAK BUT RADAR-DETECTED BOUNDARY MAKING ITS WAY TOWARD THE REGION
FROM THE NORTH. THIS FEATURE STRETCH FROM NEAR PITTSBURGH NE TOWARD
S CNTRL NY...DRIFTING SE. THE 05Z RUN OF THE HRRR IS ACTUALLY
CREATING A THIN LINE OF WEAK CONVECTION ACROSS CNTRL PA THAT BARELY
STRETCHES JUST S ACROSS THE MASON-DIXON LINE AND MOVES E OVER THE
POST-DAWN HRS. A HANDFUL OF CELLS DEPICTED DOWN THE SPINE OF THE
APLCNS/FOOTHILLS AS WELL. AFTER THIS ACTIVITY...A FEW LULL HRS
EXPECTED UNTIL SOME OF THIS DYNAMIC FORCING FROM THE NW GETS CLOSER
AND SOME SCATTERED SHOWER/TSTM ACTIVITY INCREASES OVER THE REGION.
THE COLD FRONT WILL STILL BE LAGGING BACK ACROSS THE UPPER
MIDWEST...SO MUCH OF TODAY`S ACTIVITY WILL BE WELL AHEAD OF THE MAIN
FRONTAL BOUNDARY. HOWEVER...ACCORDING TO MODEL SOUNDINGS GFS/NAM
WE`RE MORE UNSTABLE NOW THAN WHEN THE SFC FEATURES MOVE THRU DURING
THE DAYTIME HRS TODAY.
AN EXTENSIVE LINE OF CONVECTION IS EXPECTED TO STRETCH BACK ACROSS
THE UPPER MIDWEST AND INTO NEW ENGLAND LATER TODAY...STILL BACK TO
OUR NORTH AND NW. AS POTENT AS THE LINE MAY BE...NEAR TERM GUIDANCE
SHOWS A FAIRLY QUICK WEAKENING OF THE UPPER VORT DRIVING THIS
ACTIVITY AS IT SLIDES BY JUST TO THE NORTH OF THE MASON-DIXON LINE.
WHILE A PORTION OF THE LINE MAY CONTINUE ACROSS THE CWA LATE TONIGHT
INTO THE OVERNIGHT HRS...ALL MEMBERS SHOWS RAPID DECREASE NOT ONLY
IN THE INTENSITY AND COVERAGE BUT A TRANSITION TO SHOWERY AND
LESS-CONVECTIVELY DRIVEN PRECIP AS COLDER/DRIER AIR MAKES IS QUICKLY
ENTRAINED INTO THE BACKSIDE OF THIS ACTIVITY.
OVERNIGHT LOWS WILL END UP AROUND 10 DEG LOWER THAN OUR CURRENT
TEMPS.
&&
.SHORT TERM /FRIDAY/...
AFTER THE COLD FRONT SWINGS THRU THE AREA LATE TONIGHT AND OFF THE
COAST. A WAVE OF "FALL" WILL SWEEP ACROSS THE REGION AS DEWPOINTS
WILL GO FROM THE 70S THU AFTN TO BARELY ABOVE 50 ON FRI AFTN. THIS
WILL NOT ONLY BE NOTICEABLE IN TERMS OF MUCH LOWER HUMIDITIES...BUT
COOL/DRY NWLY WINDS WILL MAKE THE TEMPS IN THE 70S FEEL EVEN A FEW
DEGREES LOWER THAN THE AMBIENT VALUES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
UPPER TROUGH LIFTS NORTHEAST FRIDAY NIGHT INTO SATURDAY...WITH A
REINFORCING SHOT OF DRIER AIR PUSHING INTO THE AREA AS CANADIAN HIGH
PRESSURE BUILDS IN. EXPECT PLENTY OF SUNSHINE ON SATURDAY...BUT
MAXIMA WILL ONLY CLIMB INTO THE UPPER 60S TO LOWER 70S...COOLER OVER
THE RIDGES.
SATURDAY NIGHT WILL LIKELY BE THE COOLEST NIGHT OF THE STRETCH DUE
TO FAVORABLE RADIATIONAL COOLING WITH CALM WINDS...CLEAR SKIES AND
HIGH PRESSURE CENTERED OVERHEAD. HIGH PRESSURE MOVES OFFSHORE ON
SUNDAY WITH A RETURN FLOW DEVELOPING WHICH WILL START TO MODERATE
TEMPERATURES CLOSER TO CLIMO.
COLD FRONT IS FORECAST TO DROP SOUTHWARD ON MONDAY. ECMWF IS A
LITTLE FASTER THAN THE GFS. BOTH MODELS GENERATE LOW QPF BUT GIVEN
LACK OF MOISTURE AND WEAK CONVERGENCE CONTINUE TO KEEP A DRY
FORECAST. ANOTHER AREA OF HIGH PRESSURE IS FORECAST TO BUILD IN
BEHIND THE FRONT FOR THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
FAIRLY QUIET WX FOR THE NEXT FEW HRS...W/ ONLY SOME PATCHY FOG IN
USUALLY FOG-PRONE AREAS AND INCREASING CLOUDS ALONG AND E OF THE
APLCNS. A BRIEF BRUSH W/ SOME PRECIP POSSIBLE OVER THE BALT AREA
SITES LATER THIS MRNG IF A LINE OF TSTMS DEVELOPS AS SOME MODEL
GUIDANCE SUGGESTS...BUT A VERY OUTSIDE AND ISOLATED CHANCE ATTM. THE
MORE WIDESPREAD AND HIGHER POTENTIAL WILL HOLD OFF UNTIL LATER TODAY
W/ MORE SUBSTANTIAL FORCING SPREADING OVER THE AREA. AFTER THIS
ACTIVITY MOVES THRU AN DISSIPATES LATE TONIGHT BEHIND A COLD
FRONT...BREEZY NWLY WINDS WILL SWING FROM BEHIND THE FEATURE AND
LINGER THRU FRI AFTN. CLOUDS WILL HANG AROUND BUT CIG HEIGHTS WILL
RETREAT TOWARD THE MID LEVELS...WHEREAS SOME LOW-END VFR CONDITIONS
ARE POSSIBLE DURING THE DAYTIME HRS TODAY.
HIGH PRESSURE BUILDS IN OVER THE WEEKEND FOR NO SIGNIFICANT WEATHER.
COLD FRONT IS EXPECTED TO MOVE THROUGH ON MONDAY...BUT MAY PRODUCE
LITTLE OR NO PRECIP AS IT MOVES THROUGH.
&&
.MARINE...
WINDS CONTINUE TO CHANNEL UP THE MAIN STEM OF THE BAY FROM THE
SOUTH...AS HIGH PRESSURE MOVES OFF THE COAST AND A DYNAMIC LOW PRES
SYSTEM APPROACHES FROM THE NW. THIS SYSTEM WILL BRING A COLD FRONT
ACROSS THE REGION LATER TODAY...DEVELOPING SOME SHOWERS AND TSTMS.
AFTER THE FRONT ITSELF MOVES OVER THE WATERS LATE TONIGHT...WINDS
WILL INCREASE AND SWITCH TOWARD NWLY. SCA CONDITIONS EXPECTED TO
BEGIN TOWARD SUNSET THIS EVE AND LAST THRU FRI AFTN...WEAKENING FRI
NIGHT INTO EARLY SAT.
NORTHERLY SURGE IS EXPECTED TO OCCUR DOWN THE BAY FRIDAY NIGHT WHICH
EVENTUALLY WILL REQUIRE A SCA EXTENSION. SCA WINDS MAY CONTINUE INTO
SATURDAY MORNING BEFORE WINDS DIMINISH FOR THE REST OF THE WEEKEND
AS HIGH PRESSURE BUILDS IN.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 PM EDT FRIDAY
FOR ANZ530>534-537>543.
SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT FRIDAY FOR ANZ535-
536.
&&
$$
SYNOPSIS...GMS/BPP
NEAR TERM...GMS
SHORT TERM...GMS
LONG TERM...BPP
AVIATION...GMS/BPP
MARINE...GMS/BPP
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
322 AM CDT Thu Sep 12 2013
.SHORT TERM: (Through Late This Afternoon)
Issued at 314 AM CDT Thu Sep 12 2013
Frontal boundary making very slow progress to the south across
forecast area early this morning. Thus post frontal activity making
slow progress as well, so adjusted pops accordingly. Coverage of
activity still hard to pin down. Current HRRR run continues to
show activity diminishing over the next several hours across
northern MO and central IL, before refiring late this morning/early
this afternoon closer to I-70 corridor, then slide south. So timed
pops similar to this scenario. Still looks like front and pcpn to
exit by sunset. Otherwise, this is a transition day with highs
still above normal in the mid to upper 80s.
Byrd
.LONG TERM: (Tonight through Wednesday)
Issued at 314 AM CDT Thu Sep 12 2013
By tonight, surface ridge to build in bringing cooler and drier
weather for Friday and Saturday. Tonight`s lows will be in the low
50s to low 60s. Highs will be in the 70s on Friday and Saturday with
lows between 45 and 50 Friday night and in the 50s Saturday night.
Saturday night ridge begins to move off to the east allowing
southerly flow to return once again. Next weather system approaches
area as well with front moving into northern MO by Sunday. Timing
and coverage hard to pin down, so will just keep chance pops going
for northern portions of forecast area Sunday. Pcpn to move a bit
further south Sunday night, but coverage to remain scattered and
mainly along and north of I-70.
Front to remain stalled out over forecast area, wavering back and
forth. So trying to pin down pcpn chances hard to do, so will just
have chance pops for portions of the area through the rest of the
forecast period. Though best chances appear to be on Wednesday for
most of the forecast area.
As for temperatures, to remain at or just below normal Sunday
through next Wednesday.
Byrd
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1145 PM CDT Wed Sep 11 2013
VFR conditions are expected to prevail at the TAF sites thru the
valid period. An initial cold front, near KPPQ and just north of
KMBY, will drop S to at least the Interstate 70 corridor late
tonight, and this will be followed relatively quickly by a second
cold front very late tonight and into Thursday morning from north
to south. SHRA/TSRA has reformed nicely across northern MO and
central IL this evening, but we are still expecting it to really
only affect KUIN overnight with very little left by the time
anything gets close to the other TAF sites. The pair of cold
fronts moving thru will progressively veer the winds to NW-N by
Thursday afternoon with some gust potential possible during the
afternoon near KUIN.
Specifics for KSTL: VFR conditions will prevail thru the period.
Unfavorable time for a pair of cold fronts to be moving thru: the
first late tonight and the second late Thursday morning, and so
have kept the mention of rain out. There could be sprinkles in the
area, but still too much in doubt. Surface winds will progressively
veer from to NW-N by Thursday afternoon with the strongest winds
during that afternoon.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1145 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 06z TAFs through 06z Thursday Night)
Issued at 1145 PM CDT Wed Sep 11 2013
VFR conditions are expected to prevail at the TAF sites thru the
valid period. An initial cold front, near KPPQ and just north of
KMBY, will drop S to at least the Interstate 70 corridor late
tonight, and this will be followed relatively quickly by a second
cold front very late tonight and into Thursday morning from north
to south. SHRA/TSRA has reformed nicely across northern MO and
central IL this evening, but we are still expecting it to really
only affect KUIN overnight with very little left by the time
anything gets close to the other TAF sites. The pair of cold
fronts moving thru will progressively veer the winds to NW-N by
Thursday afternoon with some gust potential possible during the
afternoon near KUIN.
Specifics for KSTL: VFR conditions will prevail thru the period.
Unfavorable time for a pair of cold fronts to be moving thru: the
first late tonight and the second late Thursday morning, and so
have kept the mention of rain out. There could be sprinkles in the
area, but still too much in doubt. Surface winds will progressively
veer from to NW-N by Thursday afternoon with the strongest winds
during that afternoon.
TES
&&
.CLIMATE:
Issued at 1145 PM CDT Wed Sep 11 2013
A record high temperature of 98 degrees was set at Saint Louis on
Wednesday, 9/11. This breaks the old record of 97 set in 1938.
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1239 AM CDT THU SEP 12 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 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1228 AM CDT THU SEP 12 2013
MID LEVEL FORCING WILL CONTINUE TO BRING SHOWERS AND PERHAPS A
RUMBLE OF THUNDER TO THE REGION OVERNIGHT...BUT WITH THE BULK OF
THE ACTIVITY SOUTH OF THE TERMINAL...WILL LEAVE MENTION AS VCSH.
THE WEAK SURFACE PATTERN IN PLACE...INCLUDING THE DIFFUSE FRONTAL
BOUNDARY...WILL CONTINUE TO BRING LIGHT AND VARIABLE WINDS THROUGH
THE MORNING. WINDS ARE EXPECTED TO GRADUALLY BECOME MORE
NORTHEAST/EASTERLY THROUGH THE PERIOD...AS THE SFC BOUNDARY SLIDES
FURTHER SOUTH. AT THIS POINT...ANY CLOUD COVER IS NOT EXPECTED TO
RESULT IN ANY RESTRICTIONS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...SALTZMAN
AVIATION...ADO
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1237 AM CDT THU SEP 12 2013
.SYNOPSIS...
ISSUED AT 329 PM CDT WED SEP 11 2013
A SHORTWAVE TROUGH OVER CENTRAL CANADA WAS MOVING SOUTHEASTWARD
INTO THE NORTHERN TIER CONUS...HELPING TO AMPLIFY A LARGE LONGWAVE
TROUGH OVER MOST OF THE NORTHEASTERN US AND EASTERN CANADA.
FURTHER WEST A REX BLOCK WAS STARTING TO BREAK DOWN OVER THE
WESTERN CONUS...WITH A CLOSED LOW CENTERED NEAR LAS VEGAS BRINGING
PACIFIC MOISTURE NORTHWARD INTO THE EASTERN ROCKIES AND HIGH
PLAINS. AT THE SFC A WEAK FRONT WAS STALLED NEAR THE NE/KS
BORDER...WITH COOLER TEMPERATURES IN THE 70S AND MORE CLOUD COVER
TO THE NORTH OF FRONT.
&&
.SHORT TERM UPDATE...
ISSUED AT 954 PM CDT WED SEP 11 2013
BOTH THE NAM12 AND THE HRRR FORECAST SOUNDINGS INDICATE FOG IN THE
PLATTE RIVER VALLEY AND SOUTHWEST NEBRASKA. TEMPERATURES IN THE
UPPER 50S AND A UNIFORMLY MOIST BOUNDARY LAYER ARE FAVORABLE FOR
FOG. THE NORTH PLATTE SOUNDING THIS EVENING SUPPORTS THAT
SCENARIO...SO WE HAVE ADDED PATCHY FOG TO THE FORECAST IN THOSE
AREAS.
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 329 PM CDT WED SEP 11 2013
MODELS ARE IN AGREEMENT FOR A BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS ACROSS THE SOUTHERN HALF OF THE CWA THIS EVENING. A
WEAK SHORTWAVE WILL MOVE NORTH OUT OF EASTERN CO/WESTERN
KS...LIFTING AMPLE AMOUNTS OF MOISTURE OVER A STALLED FRONT JUST
SOUTH OF THE CWA. BEST CHANCES WILL BE IN OUR FAR SOUTHWEST
ZONES...GENERALLY SOUTH AND WEST OF A LINE FROM HAYES CENTER TO
OGALLALA. MONSOONAL PACIFIC MOISTURE FETCH ALOFT AND MOIST EASTERLY
FLOW NEAR THE SFC HAS LOCAL PWATS RUNNING CLOSE TO 2 STANDARD
DEVIATIONS ABOVE CLIMO. THIS COMBINED WITH SLOW NORTHERLY STORM
MOTIONS COULD PRODUCE LOCALLY HEAVY RAINFALL. MORE UNCERTAINTY
EXISTS FURTHER NORTH AS DRY AIR WILL IMPEDE NORTHWARD EXPANSION. THE
NORTHERN HALF OF THE CWA SHOULD REMAIN DRY.
SHOWER AND THUNDERSTORM CHANCES PERSIST INTO THURSDAY MORNING
ACROSS SOUTHWEST NEBRASKA. DRY AIR WILL CONTINUE TO SPILL INTO THE
NORTHERN AND EASTERN ZONES OF THE CWA AS THE REX BLOCK OUT WEST
CONTINUES TO BREAK DOWN AND HIGH PRESSURE ALOFT MOVES INTO THE
NORTHERN PLAINS. HAVE INCREASED HIGHS SLIGHTLY TO ACCOUNT FOR LATEST
MODEL TREND TO PUSH DRY AIR FURTHER WEST AND DECREASE CLOUD
COVERAGE. SLIGHT CHANCE POPS HAVE BEEN LIMITED TO FAR SOUTHWEST
NEBRASKA BY THE AFTERNOON HOURS WITH MOST MODEL SOLNS KEEPING THE
CWA DRY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 329 PM CDT WED SEP 11 2013
MODELS ARE IN FAIR AGREEMENT THROUGH THIS PERIOD. THURSDAY NIGHT
BEGINS WITH A LONGWAVE TROUGH OVER EASTERN CANADA...THROUGH THE
GREAT LAKES AND NORTHEAST CONUS. A LARGE RIDGE WILL SIT OVER THE
WESTERN HALF OF THE COUNTRY WHILE THE CUTOFF UPPER LOW DISCUSSED
EARLIER WILL BE SITUATED OVER NEVADA/IDAHO/UTAH.
THE MODELS CONTINUE TO TREND DRIER FOR THE FORECAST AREA DUE TO A
STRONG AND DRY AREA OF HIGH PRESSURE DROPPING SOUTHEAST OUT OF
CANADA. WHILE THE LARGE SCALE FLOW OVER THE LOCAL AREA WILL NOT
BE STRONG WITH THE UPPER RIDGE OVERHEAD...THE UPPER LOW WILL BE
PUSHING MONSOONAL MOISTURE UP ALONG THE ROCKY MOUNTAIN RANGE AND
THE HIGH PLAINS. THE NAM AND THE GFS ARE SHOWING PRECIPITABLE
WATER ABOVE 130 PERCENT OF NORMAL WITH THIS INFLUX OF MOISTURE SO
THINKING WHEREVER RAIN FALLS...COULD GET SOME HIGH AMOUNTS. THAT
BEING SAID...BY THURSDAY EVENING THE SURFACE HIGH LOOKS TO BE
CENTERED OVER EASTERN NORTH DAKOTA/NORTHERN MINNESOTA. THIS
CANADIAN AIRMASS WILL BE VERY DRY...WITH DEWPOINTS DOWN IN THE 40S
AND WILL COLLIDE WITH THE MOISTURE COMING INTO THE AREA FROM THE
SOUTH. THIS COLLISION WILL LIKELY LEAD TO A VERY NARROW GRADIENT
OF WET/CLOUDY CONDITIONS TO DRY/CLEAR CONDITIONS. THE MODEL TREND
IS SHOWING THE SURFACE HIGH BEING STRONGER AND DRIER THROUGH
FRIDAY...HAVE NARROWED THE GRADIENT BETWEEN NO PRECIPITATION
CHANCES TO SCATTERED CHANCES. THERE ARE SOME SOLUTIONS SHOWING THE
LOCAL AREA STAYING COMPLETELY DRY...BUT DON/T HAVE THE CONFIDENCE
TO CUT BACK THE CHANCES OVER THE WEST AND SOUTHWEST PARTS OF THE
FORECAST YET AS A FEW MODELS CONTINUE TO PUSH THE MOISTURE INTO
THE AREA. THE QUESTION WILL BE WHAT AIRMASS WILL WIN OUT.
MOVING INTO SATURDAY...THE UPPER LOW WILL BREAKDOWN WITH A DECENT
SHORTWAVE TROUGH MOVING ACROSS NEBRASKA. THIS SHOULD BRING A
HIGHER CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS THE FORECAST
AREA. ALSO FOR SATURDAY...A WARM FRONT LOOKS TO MOVE THROUGH TO
BRING SOME WARMER AIR IN WITH TEMPERATURES POSSIBLY BACK INTO THE
UPPER 70S AND 80S. THE FRONT WILL BE PUSHED BACK SOUTH SATURDAY
NIGHT AND IS CURRENTLY LOOKING TO BE SITUATED ROUGHLY ALONG THE
NEBRASKA/KANSAS BORDER. ASSUMING THIS FRONT REMAINS STATIONARY AS
THE MODELS ARE INDICATING...RAIN CHANCES WILL BE ON THE INCREASE
FOR THE FIRST HALF OF THE WEEK...MAINLY ALONG AND SOUTH OF
INTERSTATE 80.
THERE CONTINUES TO BE GOOD MODEL AGREEMENT THROUGH THE MIDDLE PART
OF NEXT WEEK AS ANOTHER LONGWAVE TROUGH DROPS INTO THE GREAT
LAKES...BRINGING YET ANOTHER COLD FRONT AND SURFACE HIGH INTO THE
UPPER MISSISSIPPI RIVER VALLEY. THIS WOULD MEAN AUTUMN-LIKE
TEMPERATURES FOR NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1236 AM CDT THU SEP 12 2013
RADAR ECHOES IN SOUTHWEST NEBRASKA ARE SHOWING A WEAKENING
TREND...SO THE PROBABILITY OF THUNDER AT ANY ONE POINT IS VERY LOW.
STILL...SHOWERS CAN BE EXPECTED.
THE EVENING SOUNDING FROM LBF IS GIVING A BIT OF A FOG SIGNAL AND
SHORT RANGE FORECAST SOUNDINGS BEAR IT OUT. ALSO...RESIDUAL
MOISTURE FROM THE RAIN THIS EVENING HAS MOISTENED THE BOUNDARY
LAYER. THE AREA MOST LIKELY TO HAVE VISIBILITY BELOW 3SM WOULD BE
THE PLATTE RIVER VALLEY FROM NEAR OGA TO EAST OF LBF. THE
STATISTICAL OUTPUT FROM AT LEAST ONE MODEL INDICATES A FAIRLY HIGH
PROBABILITY OF CEILING BELOW 1000 FEET AGL AT LBF. CONSIDERING THE
GUIDANCE...WE WILL INCLUDE VERTICAL VISIBILITY LESS THAN 1000 FEET
AGL AND VISIBILITY AROUND 1SM IN THE TERMINAL FORECAST FOR LBF.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MARTIN
SHORT TERM...MARTIN
LONG TERM...BROOKS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BUFFALO NY
120 AM EDT THU SEP 12 2013
.SYNOPSIS...
A COLD FRONT WILL DROP ACROSS THE REGION...BRINGING SHOWERS AND
THUNDERSTORMS TONIGHT AND THURSDAY. AFTER A COUPLE OF VERY WARM
TO HOT DAYS...EXPECT A SIGNIFICANT DROP IN TEMPERATURES FOLLOWING
THE COLD FRONT...WITH HIGH TEMPERATURES EXPECTED TO BE WELL BELOW
AVERAGE ON FRIDAY AND SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
A COMPLEX OF THUNDERSTORMS WILL MOVE INTO WESTERN NEW YORK THROUGH
THE EARLY MORNING HOURS...WITH THE LEADING EDGE EXPECTED TO REACH
THE BUFFALO METRO AREA JUST SHY OF MIDNIGHT. ITS INTERESTING TO
NOTE THAT RUNS OF THE HRRR HAVE NOT CAPTURED THIS WELL AT
ALL...HOWEVER THE 00Z NAM AND 12Z RGEM HAVE A FAIRLY GOOD HANDLE
ON IT. THIS COMPLEX SHOULD PRETTY MUCH TRACK ENE WITH THE UPPER
LEVEL FLOW...AND MOVE ACROSS NORTHERN PORTIONS OF THE CWA DURING
THE EARLY MORNING HOURS. WITH GREATER INSTABILITY TO THE
SOUTH...EXPECT THUNDERSTORMS TO EXTEND SOUTHWARD OF THE MAIN
COMPLEX...AND INTO WESTERN PORTIONS OF THE SOUTHERN TIER. THE
PRIMARY IMPACT WILL BE HEAVY RAIN FROM THE THUNDERSTORMS...BUT
SOME EMBEDDED STRONG STORMS HAVE STRONG GUSTY WINDS AS WELL.
MEANWHILE...THE COLD FRONTAL BOUNDARY WILL CONTINUE TO DROP SE
ACROSS THE REGION ON THURSDAY...WITH THE BEST CHANCE FOR SHOWERS
ALONG AND AHEAD OF THIS BOUNDARY. EXPECT FAIRLY WIDESPREAD
ACTIVITY THURSDAY MORNING...WITH THIS SHIFTING TO THE SOUTH DURING
THE AFTERNOON HOURS.
TEMPERATURES WILL CONTINUE TO BE ON THE WARM SIDE TONIGHT...WITH
LOWS IN THE UPPER 60S TO LOWER 70S. THEN FOR TOMORROW...CLOUD
COVER AND SHOWERS SHOULD KEEP TEMPERATURES IN THE 70S. IF
TEMPERATURES REMAIN WARM THROUGH MIDNIGHT...BOTH BUFFALO AND
ROCHESTER STAND TO BREAK THE RECORD FOR WARMEST LOW TEMPERATURES.
THE RECORD FOR FOR BUFFALO IS 72 (1931)...AND FOR ROCHESTER IS
71 (1931).
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
NOTABLY COOLER AND LESS HUMID CONDITIONS WILL BE PLACE DURING THIS
PERIOD AS A LONGWAVE TROUGH WILL BE IN PLACE ACROSS THE EASTERN HALF
OF NORTH AMERICA. THIS WILL RESULT IN BELOW NORMAL TEMPERATURES...BY
AS MUCH AS 10 DEG F...WHILE HIGH PRESSURE OF CANADIAN ORIGIN WILL
PROVIDE US WITH PLENTY OF DRY WEATHER. THE EXCEPTION TO THE FAIR
WEATHER WILL BE FOUND EARLY IN THIS TIME FRAME WHEN NUISANCE SHOWERS
WILL BE FOUND OVER PARTS OF THE REGION.
A SHORTWAVE OVER NUNAVUT AT MIDDAY WILL DIG SOUTHEAST ACROSS WESTERN
ONTARIO AND THE UPPER GREAT LAKES TONIGHT AND THURSDAY...AMPLIFYING
A BROAD BASED TROUGH THAT IS ALREADY IN PLACE. AS THIS FEATURE
ROUNDS THE BASE OF THE LONGWAVE TROUGH OVER THE LOWER GREAT LAKES
THURSDAY NIGHT...IT MAY HELP TO ENHANCE WHAT OTHERWISE WOULD BE A
WEAK LAKE RESPONSE FROM THE FRESH CHILLY AIRMASS. THIS WILL RESULT
IN SOME LIGHT SHOWER ACTIVITY...WHICH WILL BE COVERED WITH CHC POPS.
CONTINUED COLD ADVECTION THURSDAY NIGHT WILL ALLOW H85 TEMPS TO DROP
TO BETWEEN ZERO AND 4C OVER OUR FORECAST AREA...SO OUR CORRESPONDING
NR SFC TEMPS WILL INTO THE UPPER 40S AND LOWER 50S. THESE READINGS
WILL BE 20 DEG F LOWER THAN THOSE FROM THE PREVIOUS FEW NIGHTS WHEN
MERCURY READINGS WERE HELD UP IN THE 70S FOR MOST SITES.
FRIDAY WILL BE QUITE COOL ACROSS OUR FORECAST AREA. EVEN IF THE
AIRMASS WERE FULLY MIXED...H85 TEMPS IN THE VCNTY OF ZERO C WILL
ONLY SUPPORT AFTERNOON TEMPS IN THE MID TO UPPER 50S (NR 60 CLOSE TO
THE WARMER LKS). THE MORE AUTUMN-LIKE MERCURY LEVELS WOULD NOT BE
COMPLETE THOUGH WITHOUT CLOUDS AND THE CHANCE FOR SHOWERS. A
SECOND...TWIN MID LEVEL DISTURBANCE WILL SWEEP THROUGH THE BASE OF
THE LONGWAVE TROUGH DURING THE COURSE OF THE DAY. THIS FEATURE WILL
COMBINE WITH A WEALTH OF LOW LEVEL MOISTURE AND LAKE INDUCED/
DIURNALLY ENHANCED LOW LEVEL INSTABILITY TO PRODUCE MOSTLY CLOUDY
SKIES ALONG WITH SOME MORE SCATTERED LIGHT SHOWERS. THE COVERAGE AND
INTENSITY OF THESE SHOWERS WILL BE SUPPRESSED BY A 2-3 DEG CAP
SUPPLIED BY STRONG HIGH PRESSURE CENTERED OVER THE UPPER GREAT LAKES.
FAIRLY SIGNIFICANT HGT RISES IN THE WAKE OF THE SECOND SHORTWAVE...
COUPLED WITH MID LEVEL DRYING...WILL BRING AN END TO THE SHOWERS IN
MOST AREAS LATE FRIDAY OR EARLY FRIDAY EVENING. THE EXCEPTION WILL
COME SOUTHEAST OF LK ONTARIO WHERE SOME NUISANCE LAKE INDUCED SHOWER
ACTIVITY WILL BE POSSIBLE. IT WILL BE RATHER CHILLY FRIDAY NIGHT
WITH TEMPS FALLING INTO THE UPPER 30S TO MID 40S.
EXPANSIVE SFC HIGH PRESSURE WILL DRIFT SOUTHEAST ACROSS THE UPPER
OHIO VALLEY AND MIDDLE ATLANTIC STATES SATURDAY AND SATURDAY NIGHT.
THE ASSOCIATED SUBSIDENCE AND MID LEVEL DRYING SHOULD LEAD TO
BEAUTIFUL EARLY FALL WEATHER FOR THE START OF THE WEEKEND...WITH
WEAK WARM ADVECTION PUSHING SATURDAY AFTERNOON TEMPERATURES BACK
ABOVE 60 FOR MOST AREAS. MEANWHILE...IT WILL BE SEASONABLY CHILLY
SATURDAY NIGHT WITH MINS RANGING FROM THE MID 40S ACROSS THE LAKE
PLAINS TO BETWEEN 35 AND 40 IN THE SRN TIER VALLEYS WHERE THERE
COULD BE A TOUCH OF FROST.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE LONG RANGE PORTION OF THE FORECAST PACKAGE WILL REMAIN
UNEVENTFUL...AS RIDGING OVER THE WESTERN HALF OF THE COUNTRY WILL
PUSH EAST ACROSS THE PLAINS TO THE UPPER GREAT LAKES. MEANWHILE...
THE CORRESPONDING SFC HIGH WILL SETTLE SOUTHEAST FROM THE PLAINS OF
SASKATCHEWAN...EVENTUALLY ENDING UP ALONG THE MID ATLANTIC COAST BY
THE MIDDLE OF NEXT WEEK. THIS WILL KEEP OUR REGION GENERALLY RAIN
FREE...WITH JUST THE PASSAGE OF A MOISTURE STARVED COLD FRONT SUNDAY
NIGHT BEING THE ONLY POSSIBLE WEATHER MAKER FOR THIS TIME PERIOD.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
SHOWERS AND THUNDERSTORMS DEVELOPING AHEAD OF AN APPROACHING COLD
FRONT WILL CONTINUE TO PUSH EAST ACROSS THE AREA EARLY THIS MORNING.
THE HEAVIEST RAIN WILL IMPACT AN AREA STRETCHING FROM LAKE ONTARIO
TO THE ST LAWRENCE RIVER. WHILE MAINLY VFR CONDITIONS WILL
PREVAIL...VSBYS COULD LOWER TO MVFR/IFR AT TIMES...ESPECIALLY VCNTY
OF KART WHERE THE CHANCE FOR THUNDERSTORMS WILL BE GREATEST EARLY
THIS MORNING.
A SECOND COLD FRONT WILL CROSS THE AREA LATER THIS MORNING INTO THE
EARLY AFTERNOON. A FEW MORE SHOWERS/THUNDERSTORMS MAY ACCOMPANY THIS
FRONT. ONCE AGAIN...EXPECT MAINLY VFR CONDITIONS TO PREVAIL...EXCEPT
IN THE VCNTY OF PASSING SHOWERS OR THUNDERSTORMS WHERE REDUCTIONS IN
VSBY ARE POSSIBLE.
A NORTHERLY FLOW OF MOIST AIR WILL SET UP BEHIND THE FRONT TONIGHT.
EXPECT CIGS TO LOWER TO MVFR IN THE MOIST UPSLOPE FLOW. SOME PATCHY
FOG IS ALSO POSSIBLE.
OUTLOOK...
FRIDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
SATURDAY THROUGH MONDAY...VFR.
&&
.MARINE...
WINDS WILL REMAIN MODEST...BUT SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THIS EVENING AND TONIGHT. SCATTERED THUNDERSTORMS
ARE POSSIBLE LATE IN THE DAY...BUT THE BEST CHANCE FOR STORMS WILL
BE LATER TONIGHT AND THURSDAY WHEN A COLD FRONT PUSHES EAST ACROSS
THE LOWER GREAT LAKES. A NORTHWEST FLOW OF NOTICEABLY COOLER AIR
BEHIND THE FRONT AIR MAY RESULT IN SMALL CRAFT ADVISORY CONDITIONS
LATE THURSDAY INTO FRIDAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...WCH
NEAR TERM...APFFEL/WCH
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...TJP
MARINE...APFFEL/TJP/WCH
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1221 AM EDT THU SEP 12 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 THIS MORNING/...
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO INCREASE IN COVERAGE
AHEAD OF AN ADVANCING COLD FRONT. THE MODELS HAVE BEEN CONSISTENT
IN INDICATING AN INCREASE IN SHOWERS AND THUNDERSTORMS BY
DAYBREAK. MADE SOME MINOR CHANGES TO THE LOWS.
&&
.SHORT TERM /6 AM THIS 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 /04Z THURSDAY 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...KIELTYKA
SHORT TERM...MULLEN
LONG TERM...ADAMS
AVIATION...ADAMS
MARINE...ADAMS
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
426 AM CDT THU SEP 12 2013
.SHORT TERM (TODAY THROUGH FRIDAY)...ISOLATED SHOWERS CONTINUE
EARLY THIS MORNING OVER SOME INLAND LOCATIONS BUT MOSTLY OVER THE
GULF WATERS. WITH THAT...HAVE SOME CONCERNS THAT CONDITIONS ARE
NOT DRYING OUT AS MUCH AS THE NAM HAS BEEN ADVERTISING THE LAST
SEVERAL DAYS. WILL KEEP 20 POPS TODAY FOR MOST OF THE AREA DESPITE
UPPER RIDGE MOVING BACK A BIT FURTHER TO THE WEST. LATEST RUNS OF
THE HRRR SUPPORT AT LEAST LOW END SHOWER/THUNDERSTORM CHANCES...
BUT COVERAGE SHOULD BE LESS THAN THE PAST FEW DAYS. EXPECT MOSTLY
LOWER 90S TODAY FOR AFTERNOON HIGHS...WITH A FEW SPOTS OUT WEST
PERHAPS CLIMBING INTO THE MIDDLE 90S. ANY CONVECTION THAT DEVELOPS
SHOULD DIMINISH WITH THE LOSS OF DAYTIME HEATING THIS EVENING.
MODELS PROG DEEPER MOISTURE RETURNING FROM THE SOUTH AND SOUTHEAST
ON FRIDAY. THIS WILL RESULT IN BETTER CHANCES OF SHOWERS AND
THUNDERSTORMS ACROSS THE SOUTHERN HALF OF THE REGION.
&&
.LONG-TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...UPPER RIDGING DRIES
THE MIDLEVELS...HOWEVER PLENTY OF MOISTURE REMAINS JUST ABOVE THE
SURFACE TO ALLOW FOR ISOLATED DEVELOPMENT ON SATURDAY...MAINLY
ACROSS THE SOUTHERN PORTIONS OF THE CWA. TEMPERATURES SHOULD REMAIN
JUST NEAR NORMAL EARLY IN THE EXTENDED.
ABOUT THE AREA OF LOW PRESSURE MOVING INTO THE SOUTHERN BAY OF
CAMPECHE TODAY. MODELS BEGINNING TO AGREE ON MID LEVEL CLOSED LOW
DEVELOPMENT...WITH THE CANADIAN MAINTAINING AN OPEN WAVE AS FARTHER
WESTWARD MOVEMENT OCCURS. THE HURRICANE CENTER IS LOOKING AT LIKELY
TROPICAL CYCLONE DEVELOPMENT DURING THE NEXT COUPLE OF DAYS...WITH A
60 PERCENT CHANCE OF BECOMING A TROPICAL CYCLONE WITHIN THE NEXT 48
HOURS...AND 80 PERCENT CHANCE DURING THE NEXT 5 DAYS. POSITIONING OF
THE UPPER RIDGE REMAINS ACROSS THE SOUTHERN U.S....KEEPING A GENERAL
WEST-NORTHWESTWARD FLOW WITH THIS SYSTEM...MOVING TOWARD THE MIDDLE
MEXICAN COAST. MOISTURE FROM THIS SYSTEM IS STILL EXPECTED TO AFFECT
SOUTH TEXAS BRINGING SCATTERED SHOWERS AND THUNDERSTORMS AS EARLY AS
SUNDAY THROUGH MUCH OF NEXT WEEK. IN ADDITION...AN INCREASE IN
SWELLS AND RIP CURRENT RISKS IS EXPECTED DURING THIS TIME FRAME. AS
FOR TEMPERATURES DURING THIS TIME PERIOD...TRENDED SIMILAR TO THE
PAST DAYS OF RAINFALL WITH HIGHS IN THE UPPER 80S TO NEAR 90.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 93 76 93 77 93 / 20 10 20 20 20
VICTORIA 94 73 93 74 95 / 20 10 10 10 20
LAREDO 95 74 95 77 96 / 20 10 20 20 20
ALICE 95 73 93 74 94 / 20 10 20 10 20
ROCKPORT 92 76 92 78 91 / 20 20 20 20 20
COTULLA 95 72 97 74 97 / 10 10 10 10 20
KINGSVILLE 94 74 93 75 94 / 20 10 20 20 20
NAVY CORPUS 90 78 90 78 90 / 20 20 20 20 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TB/78...SHORT TERM
CB/85...LONG TERM
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
941 AM MDT THU SEP 12 2013
.UPDATE...MAJOR FLOODING/FLASH FLOODING EVENT UNDERWAY AT THIS
TIME WITH BIBLICAL RAINFALL AMOUNTS REPORTED IN MANY AREAS IN/NEAR
THE FOOTHILLS. PRECIPITABLE WATER VALUES IN EXCESS OF AN INCH AND
A QUARTER ON GPS SENSORS CERTAINLY SUPPORT LOTS MORE RAIN TODAY
AND TONIGHT. 13Z HRRR RUN HAS ANOTHER 1-3 INCHES OF RAIN
PREDICTED IN THE FOOTHILLS THROUGH 04Z SO THINGS ARE NOT LOOKING
GOOD. WILL EXTEND THE AREA OF THE FLASH FLOOD WATCH TO INCLUDE
ZONE 43 AND ALSO EXTEND IT IN TIME THROUGH 12Z TOMORROW MORNING.
&&
.AVIATION...UPSLOPE CONDITIONS WILL PERSIST THROUGH TODAY WITH LOTS
OF LOW CLOUDINESS AND SHOWER ACTIVITY EXPECTED.
&&
.HYDROLOGY...FLOODING ONGOING IN LOTS OF SPOTS INCLUDING THE
FOOTHILLS BURN AREAS. A DIRE SITUATION WHICH WILL NOT IMPROVE
DURING THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 446 AM MDT THU SEP 12 2013/
SHORT TERM...LITTLE CHANGE IN THE OVERALL PATTERN DURING THE
NEXT 24 HOURS. UPPER LEVEL LOW CENTERED OVER THE SOUTHERN GREAT
BASIN WILL SLOWLY SHIFT NORTHWARD TOWARDS SOUTHEAST IDAHO NEXT 24
HOURS. A VERY MOIST SOUTH-SOUTHWEST FLOW ALOFT...AND A VERY MOIST
SOUTHEASTERLY LOW-LEVEL FLOW WILL PROBABLY SET THE STAGE FOR
ANOTHER ROUND OF MODERATE TO HEAVY WARM PROCESS RAINFALL OVER AND
ALONG THE COLORADO FRONT RANGE THIS AFTERNOON AND EVENING.
VERY HEAVY RAINFALL OVER THE PAST 12 HOURS...SATURATED SOILS AND
THE MODERATE TO HEAVY RAINFALL EXPECTED AGAIN THIS AFTERNOON AND
EVENING NECESSITATE ISSUANCING A FLASH FLOOD WATCH FOR THE FRONT
RANGE FOOTHILL ZONES 35/36 AND I-25 URBAN CORRIDOR ZONES
38..39..40 AND 41. WATCH WILL RUN FROM 18Z/TODAY TO 06Z/TONIGHT.
MODERATE TO HEAVY RAINFALL STILL OCCURRING OVER AND NEAR THE
FOOTHILLS AT THIS HOUR. COULD SEE SIMILAR RAINFALL RATES FOR THE
NEXT FEW HOURS BEFORE LETTING UP AROUND MID-MORNING. AREAS OF
DENSE FOG ON THE PLAINS MAY BE AN ISSUE AROUND SUNRISE. RAINFALL
AMOUNTS TODAY NOT EXPECTED TO BE AS GREAT AS THOSE OBSERVED DURING
THE PAST 18 HOURS...BUT IT WOULDN/T TAKE MUCH TO CAUSE FLOODING
AGAIN. RAINFALL EXPECTED TO BECOME HEAVIER AND MORE WIDESPREAD
LATER THIS AFTERNOON AND EVENING IN ADVANCE OF A WEAK SHORT WAVE
TROUGH LIFTING NORTHWARD ACROSS THE REGION OVERNIGHT. SHOULD SEE
LITTLE IF ANY SUNSHINE EAST OF THE MTNS TODAY.
CONSEQUENTLY...LITTLE WARMING TODAY. WHEREAS AREAS ON THE WEST
SLOPE COULD SEE A BIT MORE SUNSHINE WITH LOW-LEVEL EASTERLY/
DOWNSLOPE FLOW. HOWEVER WITH ALL THE MOIST AIR AROUND...SUNSHINE
WILL HAVE LITTLE PROBLEM GENERATING T-STORMS THIS AFTERNOON.
LONG TERM...ON FRIDAY...AIRMASS NOT QUITE AS MOIST WITH THE
UPPER LOW TRACKING NORTHEAST TOWARDS WYOMING. THIS CAUSES THE
FLOW ALOFT TO BECOME MORE SOUTHWESTERLY. THIS RESULTS IN MODEST
DRYING AT MID-LEVELS...ESPLY WEST OF THE FRONT RANGE. CONSEQUENTLY
RAIN CHANCES SLIGHTLY LOWER...PARTICULARLY IN THE HIGH COUNTRY
WEST OF THE CONTINENTAL DIVIDE. MORE SUNSHINE IN THESE AREAS WILL
WARM TEMPERATURES A FEW DEGS C. EAST OF THE MTNS LITTLE WARMING
ANTICIPATED.
ON SATURDAY...DRYING PROGRESSES AS THE UPPER LOW OPENS UP INTO AN
OPEN TROUGH. TROUGH SWINGS ACROSS WYOMING AND MONTANA CAUSING WINDS
ALOFT TO GO MORE WESTERLY. THIS WILL HELP DRY AIR THE PLAINS AIRMASS
AND LOWER THE CHANCE OF SHOWERS/T-STORMS EAST OF THE MTNS.
TEMPERATURES ALSO RETURN TO NEAR AVERAGE FOR THE DATE.
SATURDAY NIGHT AND SUNDAY...AS THE UPPER TROUGH PASSES TO OUR
NORTH...A COLD FRONT DROPS SOUTH OUT OF WYOMING AND INTO NORTHEAST
COLORADO TOWARDS MORNING. POST FRONTAL UPSLOPE FLOW COMBINED WITH A
FAIR AMOUNT OF MOISTURE AROUND EXPECTED TO GENERATE SCATTERED
SHOWERS/ISOLATED T-STORMS ACROSS THE FORECAST AREA...POSSIBLY MORE
SO UP ALONG THE FRONT RANGE AND OVER THE PALMER DIVIDE DURING THE
AFTERNOON. HEAVY RAINFALL AND THEREFORE THE FLOOD RISK APPEARS LOW
WITH THESE STORMS. SUNDAY TEMPERATURES COOL 3-4C EAST OF THE
MTNS...BUT LITTLE CHANGED WEST OF MTNS.
MONDAY THROUGH WEDNESDAY...EXPECT DRIER AND WARMER CONDITIONS
AREAWIDE WITH ZONAL FLOW.
AVIATION...LOW CEILINGS AND AREAS OF FOG PRODUCING INSTRUMENT
FLIGHT RULES AT DENVER AREA AIRPORTS NEXT 12-24 HOURS. LOWEST CIGS
AND VSBYS EXPECTED ALONG THE FOOTHILLS AT BJC AND APA. EAST-
SOUTHEAST WINDS OF 6-14KTS EXPECTED TODAY. TONIGHT WINDS
GRADUALLY SHIFT TO A NORTH-NORTHWEST DIRECTION AFTER 06Z TONIGHT.
HYDROLOGY...FLASH FLOOD WATCH FROM NOON TODAY TO MIDNIGHT TONIGHT
FOR THE FRONT RANGE FOOTHILL ZONES 35 AND 36...AND THE ADJACENT
I-25 URBAN CORRIDOR ZONES 38...39...40 AND 41. PERIODS OF HEAVY
RAIN IN THESE AREAS COUPLED WITH SATURATED SOILS COULD RESULT IN
ADDITIONAL FLASH FLOODING LATER TODAY. MODERATE TO HEAVY RAINFALL
STILL OCCURRING AT THIS HOUR ALONG THE NORTHERN FRONT RANGE COULD
PROMPT ADDITIONAL FLOOD/FLASH FLOOD WARNINGS DURING THE NEXT 3-5
HOURS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH TONIGHT FOR COZ035-036-038>041-043.
&&
$$
SHORT TERM...BAKER
LONG TERM....BAKER
UPDATE/AVIATION...ET
AREA FORECAST DISCUSSION
NWS ALBANY NY
1036 AM EDT THU SEP 12 2013
.SYNOPSIS...
A COLD FRONT WILL BRING ANOTHER ROUND OF STRONG TO
POTENTIALLY SEVERE THUNDERSTORMS TO EASTERN NEW YORK AND WESTERN NEW
ENGLAND THIS AFTERNOON INTO TONIGHT. SOME VERY HEAVY RAINFALL WILL
ACCOMPANY THE THUNDERSTORMS AND FRONTAL PASSAGE. AN AUTUMN AIR MASS
WILL BUILD INTO THE REGION ON FRIDAY...AND THE COOLER AND DRIER
WEATHER WILL CONTINUE INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1036 AM EDT...LATEST KENX RADAR SHOWS TWO SMALL LINES OF
SHOWERS AND THUNDERSTORMS...ONE ACROSS SRN VT/NW MASS AND THE
OTHER ACROSS DUTCHESS/LITCHFIELD COUNTIES. A BRIEF BURSTS OF RAIN
AND SOME LTG IS POSSIBLE WITH THIS ACTIVITY AS IT SLIDES EASTWARD
OVER THE NEXT HOUR...BUT NO STRONG/SVR ACTIVITY IS EXPECTED JUST
YET.
CLOUDS HAVE BROKEN FOR SOME SUN ACROSS THE REGION...ALTHOUGH
PLENTY OF CLOUDINESS REMAINS UPSTREAM ACROSS WESTERN/CENTRAL NY.
THE FCST AREA WILL ENDURE ONE MORE HUMID DAY...BEFORE BIG CHANGES
ARRIVE TONIGHT INTO FRIDAY. A COLD FRONT...AND A SFC TROUGH IN
ADVANCE OF IT WILL FOCUS MULTIPLE BANDS OF SHOWERS AND
THUNDERSTORMS. AN UPPER JET STEAK ASSOCIATED WITH THE LONGWAVE
TROUGH ADVANCING S/SE FROM S-CNTRL ONTARIO AND THE UPPER MIDWEST
WITH HELP ENHANCE THE RAINFALL...AND POTENTIALLY THE SVR THREAT
TODAY ACROSS ERN NY AND WRN NEW ENGLAND. THE ANTICYCLONIC ENTRANCE
REGION OF A 250 HPA 100-110+ KT JET STREAK WILL MOVE ACROSS NRN
AND ERN NY IN THE AFTERNOON.
OUR FCST IS NOT VERY CONFIDENT ABOUT STRONG TO SEVERE
THUNDERSTORMS OVER THE NRN TIER...DUE TO THE APPROACHING CANOPY
OF CLOUDS AHEAD OF THE COLD FRONT AND ITS LEADING PRE- FRONTAL SFC
TROUGH. HOWEVER...THE SPC SLIGHT RISK WILL BE ACCEPTED OVER THE
ENTIRE FCST AREA...AND EMPHASIZED IN THE HWO. THE BEST CHANCE FOR
SVR STORMS MAY BE FOR SOUTHERN AND EASTERN AREAS TODAY.
THE GFS/NAM ARE CONSISTENT WITH SBCAPE VALUES IN THE 1000-2000
J/KG FROM ROUGHLY THE CAPITAL REGION SOUTH AND EAST. SFC DEWPTS
WILL STILL BE ABOVE NORMAL FOR MID SEPT IN THE 60S TO EVEN SOME
L70S. THE MID LEVEL LAPSE RATES WILL NOT BE AS STEEP TODAY
/GENERALLY LESS THAN 6.5 C/KM/...AS THE REMNANT ELEVATED MIXED
LAYER HAS SHIFTED DOWNSTREAM. THE 0-6 KM BULK SHEAR VALUES
INCREASE TO 25-40 KTS BY THE AFTERNOON. MODEL SOUNDINGS INDICATE
SOME MULTICELLULAR CLUSTERS MAY FORM INTO A COUPLE OF LINES. THE
BEST CHC OF A SUPERCELL MAY BE ACROSS THE SRN EXTREME WHEN THE 0-6
KM SHEAR INCREASE TO 40 KTS AND THE SBCAPE VALUES MAY REACH 2000
J/KG. DAMAGING WINDS LOOK TO BE THE MAIN THREAT WITH BOWING
SEGMENTS...BUT WITH TALLER UPDRAFTS SOME LARGE HAIL IS POSSIBLE.
THE BEST 850-700 HPA THETA-E LAPSE RATES IMPACT LOCATIONS FROM THE
CAPITAL REGION SOUTH AND EAST TOWARDS NIGHTFALL.
THE LATEST 3KM HRRR AND LOCAL HIRES WRF SHOWS A BROKEN LINE OF
SHOWERS/THUNDERSTORMS MOVING ACROSS THE REGION THIS AFTN INTO THIS
EVENING. THIS MAKES SENSE CONSIDERING THE APPROACHING UPSTREAM
TROUGH...MARGINAL AMOUNTS OF INSTABILITY...AND SUFFICIENT SHEAR IN
PLACE.
THE SECONDARY ISSUE TODAY WILL BE THE VERY HEAVY RAINFALL. PWATS
ARE STILL WELL ABOVE NORMAL FOR MID-SEPT. THE LATEST GEFS SUGGEST
PWATS ARE 1 TO ALMOST 3 STANDARD DEVIATIONS ABOVE NORMAL. THE
ACTUAL PWATS ARE FORECAST TO BE IN THE 1.33-1.80" RANGE WITH SOME
POCKETS CLOSE TO 2.00" IN THE MID HUDSON VALLEY AND NW CT. THE
BEST H850 THETA-E RIDGE SETS UP FROM THE CAPITAL REGION...SRN
VT...AND THE ERN CATSKILLS SOUTH AND EAST /330-335 K RANGE/. SOME
TRAINING MAY OCCUR WITH THE LINES OF CONVECTION. AN ISOLD FLASH
FLOOD OR TWO WILL BE POSSIBLE. THE COVERAGE IS NOT EXPECTED TO BE
LARGE ENOUGH FOR A FLASH FLOOD WATCH. OUR HYDRO DISCUSSION GETS
INTO MORE DETAILS ON THE RAINFALL BELOW.
POPS WILL BE JUST SLIGHT CHC/CHC FOR THE REMAINDER OF THE MORNING
AND RISE TO THE LIKELY TO CATEGORICAL RANGE FROM THE AFTERNOON INTO
THE EVENING. HEAVY RAINFALL HAS BEEN MENTIONED THROUGHOUT THE
GRIDS/TEXT PRODUCTS. ALSO THE PHRASING...SOME THUNDERSTORMS MAY BE
SEVERE. TEMPS WERE FAVORED CLOSE TO THE MAVMOS VALUES WITH M70S TO
NEAR 80F NORTH AND WEST OF THE TRI CITIES...AND 80-85F SOUTH AND
EAST...EXCEPT OVER THE MTNS WHERE 70S WILL BE POSSIBLE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
TONIGHT...SIGNIFICANT LOW AND MID LEVEL HEIGHT FALLS WILL OCCUR
AHEAD OF THE UPPER TROUGH...AS THE COLD FRONT MAKES STEADY
PROGRESS ACROSS THE REGION. THE COLD FRONT WILL GIVE A MAJOR BOOT
TO THE MUGGY AND STICKY WEATHER. THERE IS THE POTENTIAL A MID
LEVEL SHORT-WAVE MAY MIGRATE ALONG THE BOUNDARY KEEPING THE STEADY
RAINFALL GOING FROM THE CAPITAL REGION SOUTH AND EAST INTO EARLY
MORNING HOURS. THE NAM/GFS/ECMWF EVEN HINT AT A WEAK SFC WAVE
MOVING ALONG THE BOUNDARY. A WIDESPREAD 1 TO 2 INCHES OF RAINFALL
MAY OCCUR FROM THE AFTERNOON INTO TONIGHT. THE CONVECTION SHOULD
SHRIVEL UP SHORTLY BEFORE MIDNIGHT...AS THE INSTABILITY WANES
CONSIDERABLY. DECENT COLD ADVECTION WILL BE SWEEPING INTO THE NRN
ZONES BEFORE DAYBREAK. LOWS WILL RANGE FROM THE MID AND U40S OVER
THE SRN DACKS TO U50S AND L60S TO THE CAPITAL REGION...MID HUDSON
VALLEY...AND NW CT.
FRIDAY...QUITE A CONTRAST IN AIR MASSES...AND TEMPERATURES IS
EXPECTED. STRONG LOW LEVEL COLD ADVECTION WILL CONTINUE...AS THE
UPPER TROUGH MOVES OVER SRN QUEBEC AND THE NORTHEAST. THE CYCLONIC
VORTICITY ADVECTION ASSOCIATED WITH THE UPPER TROUGH WILL KICK OFF
SOME ISOLD-SCT INSTABILITY SHOWERS. THE COVERAGE WILL BE GREATEST
OVER THE HIGHER TERRAIN...AND NRN ZONES. IT WILL BE BRISK AND
CHILLY. MAX TEMPS WILL BE 20 TO 30 DEGREES COOLER THAN WEDNESDAY
IN THE FALL LIKE AIR MASS. MAX TEMPS WILL BE IN THE 50S OVER THE
SRN DACKS...SOME OF THE ERN CATSKILLS...AND SRN GREENS...AND 60S
TO A FEW L70S OVER THE REST OF THE FCST AREA.
FRIDAY NIGHT...THE INSTABILITY SHOWERS WILL CEASE TOWARDS
MIDNIGHT. THE CHILLY AIR MASS WILL BE OVER THE REGION...WITH A
DECENT SFC PRESSURE GRADIENT EXPECTED TO KEEP THE WINDS UP. H850
TEMPS LOWER TO +1 TO +4C. NOT EXPECTING FROST ON THIS NIGHT. LOWS
WILL BE QUITE COOL IN THE U30S TO M40S.
SATURDAY-SATURDAY NIGHT...THE UPPER LEVEL LOW CLOSES OFF AND MOVES
DOWN STREAM OVER SE QUEBEC AND NRN NEW ENGLAND. HIGH PRESSURE
BUILDS IN FROM THE MIDWEST AND GREAT LAKES REGION. THE WINDS WILL
BE LESS ON SATURDAY...BUT BELOW NORMAL TEMPS ARE EXPECTED WITH
MAINLY MID AND U60S IN THE VALLEYS...AND 50S TO L60S OVER THE
HIGHER TERRAIN. THE SFC HIGH WILL MOVE OVER NY AND PA SATURDAY
NIGHT WITH CLEAR/MOSTLY CLEAR SKIES AND LIGHT TO CALM WINDS. NEAR
IDEAL RADIATIONAL COOLING IS EXPECTED WITH TEMPS FALLING INTO THE
30S TO L40S. SOME AREAS OF FROST MAY MATERIALIZE OVER THE SRN
DACKS REGION. A BRIEF MENTION WILL BE PLACED IN THE HWO.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
DURING THE LONG TERM PERIOD EXPECT MAINLY DRY CONDITIONS WITH THE
EXCEPTION BEING A CHANCE OF SHOWERS MAINLY ACROSS THE NORTHERN AREAS
ON SUNDAY NIGHT AHEAD OF A COLD FRONT WHICH WILL BE DROPPING
SOUTHEAST FROM SOUTHERN CANADA AND PASS THROUGH OUR FA BY MONDAY
MORNING. TEMPERATURES ARE EXPECTED TO BE SEASONABLE ON SUNDAY AND
SUNDAY NIGHT AND THEN BELOW NORMAL IN THE WAKE OF THE COLD FRONT
MONDAY THROUGH WEDNESDAY.
ON SUNDAY EXPECT HIGHS IN THE MID 60S TO LOWER 70S WITH LOWS SUNDAY
NIGHT IN THE MID 40S TO LOWER 50S. FOR MONDAY EXPECT HIGHS TO RANGE
FROM THE LOW TO MID 50S NORTHWEST TO THE UPPER 60S SOUTHEAST WITH
LOWS MONDAY NIGHT IN THE MID 30S TO LOWER 40S. ON TUESDAY EXPECT
HIGHS IN THE MID 50S TO MID 60S WITH LOWS TUESDAY NIGHT IN THE MID
30S TO MID 40S AND HIGHS ON WEDNESDAY IN THE 60S TO AROUND 70.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
MORE SHRA/TSRA ARE EXPECTED TODAY AND THIS EVENING AHEAD OF AND
ALONG A COLD FRONTAL PASSAGE. THE BEST CHANCE WILL BE FROM AROUND LATE
MORNING OR EARLY AFTERNOON INTO THE EVENING HOURS. CIGS AND VSBYS
ARE LIKELY TO DIMINISH TO MVFR/IFR WITH HEAVIER PCPN. LATER TONIGHT
THE PCPN WILL TAPER OFF HOWEVER CIGS AND VSBYS WILL DROP TO IFR/LIFR
AT MOST SITES.
LIGHT AND VARIABLE WINDS WILL BECOME SOUTH TO SOUTHWEST AT 5 TO 10
KTS TODAY AND THEN WEST TO NORTHWEST AROUND 5 KTS THIS EVENING WITH
THE PASSAGE OF THE COLD FRONT.
OUTLOOK...
FRIDAY TO SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS AT THIS TIME WITH MORE WET WEATHER TODAY
INTO TONIGHT.
A COLD FRONT WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS TO
EASTERN NEW YORK AND WESTERN NEW ENGLAND TODAY INTO TONIGHT. SOME
VERY HEAVY RAINFALL WILL ACCOMPANY THE THUNDERSTORMS AND FRONTAL
PASSAGE. AN AUTUMNAL AIR MASS WILL BUILD INTO THE REGION ON
FRIDAY...AND THE COOLER AND DRIER WEATHER WILL CONTINUE INTO THE
WEEKEND.
THE RH VALUES WILL LOWER ONLY TO 55 TO 75 PERCENT IN THE MUGGY AIR
MASS THIS AFTERNOON...AND RECOVER TO 100 PERCENT TONIGHT. EXPECT MINIMUM
RH VALUES TO 50 TO 70 PERCENT FRIDAY AFTERNOON.
THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AT 5 TO 15 MPH
TODAY...AND THEN SHIFT TO THE WEST TO NORTHWEST AT 5 TO 10 MPH
TONIGHT. EXPECT BRISK NORTHWEST WINDS OF 10 TO 20 MPH ON
FRIDAY...WITH SOME GUSTS AROUND 30 MPH.
&&
.HYDROLOGY...
MORE WIDESPREAD CONVECTION IS EXPECTED TODAY INTO EARLY THIS EVENING
WITH ADDITIONAL TORRENTIAL DOWNPOURS...ASSOCIATED WITH A STRONG
COLD FRONT AND ANOTHER PREFRONTAL TROUGH DROPPING SOUTHEASTWARD
THROUGH OUR REGION LATE TODAY AND TONIGHT. DRIER AND MUCH COOLER
WEATHER IS EXPECTED TO END THE WEEK.
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 WITH
THE SHOWERS AND THUNDERSTORMS. THERE IS EVEN A THREAT OF ISOLATED FLASH
FLOODING WHERE THUNDERSTORMS MAY REPEATEDLY MOVE ACROSS THE SAME
AREAS. THE THUNDERSTORMS SHOULD DIMINISH EARLY THIS EVENING INTO THE
OVERNIGHT HOURS. THE FFG VALUES REMAIN HIGH TODAY. THE 1-HR ZONAL
FFG VALUES ARE IN THE 1.7-2.4 INCH RANGE...AND THE 3-HR ZONAL FFG
VALUES RANGE FROM 2.1-3.1 INCHES.
INTO TONIGHT...THE HYDRO SERVICE AREA MAY RECEIVE 1 TO 2 INCHES OF
RAIN WITH LOCALLY UP TO 3 INCHES. OVERALL...MAINLY MINOR FLOODING
OF POOR DRAINAGE...URBAN...AND LOW LYING AREAS IS EXPECTED WITH
ISOLATED FLASH FLOODING. SOME SIGNIFICANT WITHIN BANK RISES WILL
OCCUR ON MAIN STEM RIVERS...BUT NO FLOODING IS EXPECTED BASED ON
THE LATEST GUIDANCE FROM THE NERFC. FLOWS REMAIN AT NORMAL TO
BELOW NORMAL LEVELS HEADING INTO MID SEPTEMBER.
THE UPPER LOW MAY FOCUS SOME ISOLD-SCT SHOWERS FRIDAY INTO EARLY
FRIDAY EVENING...BUT RAINFALL WILL BE ON THE LIGHT SIDE. THE
WEEKEND IS EXPECTED TO BE DRY WITH HIGH PRESSURE IN CONTROL.
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/WASULA
NEAR TERM...FRUGIS/WASULA
SHORT TERM...WASULA
LONG TERM...11
AVIATION...11
FIRE WEATHER...WASULA
HYDROLOGY...JPV/WASULA
AREA FORECAST DISCUSSION
NWS POCATELLO ID
904 AM MDT THU SEP 12 2013
.UPDATE...UPPER LOW IN GREAT BASIN CONTINUES TO SLOWLY MOVE NORTH.
MOISTURE STREAM ROTATING THROUGH WYOMING INTO EASTERN IDAHO
SHOWING PWAT AROUND ONE INCH...SOME 200 PERCENT ABOVE NORMAL. DRY
SLOT PUNCHING THROUGH THE SOUTHERN HALF OF FORECAST AREA WITH NO
PRECIP AND PLENTY OF CLEARING WHICH SHOULD AID IN DESTABILIZATION
TODAY. CLOSER TO CENTER OF LOW...NEXT BATCH OF MOISTURE POISED TO
PUSH INTO THE STATE WITH PWAT AGAIN AROUND ONE INCH SOME 175-180
PERCENT OF NORMAL. SURFACE DEW POINTS REMAIN HIGH AND AFTERNOON
STORM MOTION ESTIMATED TO BE AROUND 10 KTS...REGION REMAINS POISED
FOR ANOTHER BIG RAINFALL DAY. NAM REDEVELOPS WIDESPREAD CONVECTION
BY NOON...THOUGH HRRR AND LOCAL WRF LESS IMPRESSIVE THROUGH THE
DAY. FLASH FLOOD WATCH REMAINS IN EFFECT FOR PORTIONS OF THE
REGION THROUGH THE DAY AND WILL KEEP POPS HIGH WITH ISOLATED
THUNDER MENTION...ALSO HIGHLIGHTING HEAVY RAIN POTENTIAL THROUGH
THE DAY. HAVE MADE A FEW TWEAKS FOR TODAYS GRIDS FOR CURRENT
SAT/RADAR/MODEL TRENDS BUT LEFT OVERALL CHARACTER OF FORECAST
INTACT. DMH
&&
.PREV DISCUSSION... /ISSUED 332 AM MDT THU SEP 12 2013/
SHORT TERM...TODAY THROUGH SAT NIGHT. UNSTABLE AIR IN NORTHERN
UTAH CONTINUED TO GENERATE LIGHTNING EVEN AT THIS HOUR OF THE
NIGHT. THIS AIR MASS IS MOVING NORTHWARD AND SHOULD BE OVER THE
CENTRAL PORTION OF THE FORECAST AREA BY NOON. WITH PRECIPITABLE
WATER ABOVE ONE INCH...MORE UNSTABLE CAPE AND LIFTED INDEX ON THE
GFS...AND WITH A TRIGGER OF DAYTIME HEATING...EXPECT HEAVY
DOWNPOURS POSSIBLE IN THE AREA WITH PRECIPITABLE WATER ABOVE ONE
INCH. THIS IS LIMITED TODAY TO THE AREA FROM THE UTAH BORDER TO
AS FAR NORTH AS THE HAILEY AREA...AND THE WYOMING-IDAHO BORDER
REGION. ZONES WITH PROBLEMS SUCH AS RECENT LARGE BURN AREAS ON
STEEP SLOPES AND PREVIOUSLY SATURATED GROUND IN THE SOUTHERN
HIGHLANDS AND LOWER SNAKE RIVER PLAIN...HAVE LEFT THE FLASH FLOOD
WATCH IN EFFECT IN THE SAME LOCATIONS. OUTSIDE OF THUNDERSTORM
ACTIVITY...WIND SHOULD REMAIN LIGHT DURING THIS TIME. TEMPERATURES
CONTINUE SLIGHTLY ABOVE NORMAL. THE LOW MOVING IN FROM THE SOUTH
THAT BROUGHT ALL THE SOUTHERLY FLOW TO SOUTHERN IDAHO WILL
EVENTUALLY END UP IN SOUTHERN IDAHO BY THE WEEKEND...MEANING THAT
THUNDERSTORM ACTIVITY WILL CONTINUE. MESSICK
LONG TERM...SUN THROUGH NEXT WED NIGHT. AS THE LOW STARTS MOVING
FARTHER AWAY FROM SOUTHERN IDAHO ON SUNDAY...THE PRECIPITATION AND
THUNDERSTORM THREAT DECREASES STARTING MON. BY MID WEEK THE
WESTERLY FLOW THAT REPLACES THE SOUTHERLY FLOW WILL BE STRONGER
AND THUS EXPECT MORE WIND DURING THIS TIME...BUT THE MAIN AREA OF
PRECIPITATION WILL BE FARTHER NORTH. MESSICK
AVIATION...A DRY SLOT CURRENTLY TRYING TO NOSE INTO SOUTHEAST IDAHO
IN SATELLITE IMAGERY. CURRENT SCATTERED RAIN SHOWERS SHOULD MOSTLY
CLEAR KBYI AND KPIH BY 14Z...BUT REMAIN IN VICINITY AT KIDA AND
KSUN. AIR MASS BECOMES MORE UNSTABLE BY 20Z WITH THE THREAT OF
THUNDERSTORMS AT ALL TAF SITES...THEN SOME STABILIZING AFTER 03Z. RS
FIRE WEATHER...SCATTERED TO NUMEROUS SHOWERS WITH EMBEDDED
THUNDERSTORMS EXPECTED TODAY AS VERY MOIST AIR OVERSPREADS SOUTHEAST
IDAHO. THERE IS A RISK OF THUNDERSTORMS PRODUCING HEAVY DOWNPOURS
RESULTING IN MUD AND DEBRIS SLIDES ON RECENT BURN AREAS. THE LOW
PRESSURE CIRCULATION PRESENTLY OVER SOUTHERN NEVADA WILL DRIFT
SLOWLY NORTH TO IDAHO TODAY AND FRIDAY...AND EVENTUALLY BREAK UP AND
MOVE EAST THIS WEEKEND. THERE IS A CHANCE OF SHOWERS EACH DAY
THROUGH SUNDAY. A SIGNIFICANT LOWERING OF HUMIDITY PROBABLY WILL NOT
OCCUR BEFORE THE MIDDLE OF NEXT WEEK. RS
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH THIS EVENING IDZ021>025.
FLASH FLOOD WATCH FROM NOON MDT TODAY THROUGH THIS EVENING
IDZ018-031.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
950 AM CDT THU SEP 12 2013
UPDATE ISSUED AT 943 AM CDT THU SEP 12 2013
UPDATED THE FORECAST THROUGH THIS EVENING TO REFLECT THE LATEST
CLOUD AND TEMPERATURE TRENDS. IT APPEARS THERE WILL BE WIDESPREAD
PARTLY TO MOSTLY CLOUDY SKIES TODAY DUE TO THE COOL NORTHERLY FLOW
BRINGING LOW LEVEL LEVEL MOISTURE FROM CANADA. THERE IS PLENTY OF
CLOUDS UPSTREAM. I SLIGHTLY LOWERED THE TEMPERATURE FORECAST BASED
ON A WIDE BLEND OF NEWER MODEL GUIDANCE...AND I THINK THIS
REFLECTS THE CLOUD COVER AND COOL NORTHERLY FLOW WELL.
THERE SHOULD BE SOME CLEARING VERY LATE THIS AFTERNOON AND EARLY
THIS EVENING...BUT I HAVE SOME CONCERNS ON WHETHER IT WILL LINGER.
FURTHERMORE...IF THE CLOUDS LINGER...IT COULD PREVENT PARTS OF THE
FORECAST AREA FROM GETTING AS COLD AS CURRENTLY ADVERTISED...AND
THIS IN TURN COULD AFFECT OUR CURRENT HEADLINES FOR FROST AND
FREEZING TEMPERATURES. I WILL LOOK MORE INTO THIS LATER THIS
MORNING WHEN MOST OF THE 12Z MODEL GUIDANCE IS IN.
UPDATE ISSUED AT 716 CDT THU SEP 12 2013
UPDATED THIS MORNING TO INCREASE CLOUD COVER FOR STRATUS STREAMING
SOUTHEAST FROM SOUTHERN CANADA. THESE CLOUDS WILL DECREASE IN
COVERAGE BY MIDDAY.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 303 AM CDT THU SEP 12 2013
CONCERN FOR SHORT TERM IS FROST/FREEZE TONIGHT ACROSS CURRENT
FREEZE WATCH AREA.
CURRENT SURFACE ANALYSIS INDICATE SOME CLOUDS OVER THE ARROWHEAD
AND ACROSS PORTION FOR NORTHWEST WISCONSIN. THE CLOUDS SHOULD MOVE
SOUTH AND EAST OF THE FORECAST AREA BY MID-MORNING. NORTHWEST
FLOW WILL CONTINUE ACROSS THE REGION TO DAY AS THE RIDGE SLOWLY
DRIFTS EAST. THERE WILL BE SOME CU DEVELOPMENT LATE THIS MORNING AS
INDICATED BY THE CU RULE. THE CENTER OF THE RIDGE WILL BE OVER NE
MN TONIGHT. THIS WILL CAUSE LIGHT WINDS AND CLEAR SKIES ALLOWING
THE TEMPS TO DROP DOWN TO NEAR AND BELOW THE FREEZING LEVEL ACROSS
PORTIONS OF KOOCHICHING...ST. LOUIS...AND INLAND AREAS OF THE
ARROWHEAD. WILL PUT UP A FREEZE WARNING FOR NORTHERN/CENTRAL ST.
LOUIS AND INLAND LAKE AND COOK COUNTIES AND A FROST ADVISORY FOR
KOOCHICHING COUNTY. IT LOOKS THERE MAY BE A WEAK SOUTHERLY FLOW
OVER KOOCHICHING COUNTY SO TEMPS MAY NOT GET AS LOW. THE CENTER OF
THE RIDGE WILL CONTINUE TO MOVE EAST ON FRIDAY GIVING THE REGION
A MOSTLY SUNNY DAY
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 303 AM CDT THU SEP 12 2013
FRIDAY NIGHT THROUGH WEDNESDAY.
THE NORTHLAND WILL BE UNDER THE INFLUENCE OF AN UPPER RIDGE AND
DEPARTING SURFACE HIGH FRIDAY NIGHT...WITH DRY CONDITIONS EXPECTED.
A COLD FRONT...SURFACE LOW AND UPPER SHORTWAVE WILL ALL IMPACT THE
AREA SATURDAY AND SATURDAY NIGHT...POSSIBLY INTO SUNDAY AS WELL.
THESE FEATURES WILL BRING A CHANCE FOR SHOWERS AND A FEW
THUNDERSTORMS TO THE NORTHLAND...BUT SIGNIFICANT RAINFALL DOES NOT
LOOK LIKELY AT THIS TIME.
HIGH PRESSURE WILL THEN BUILD BACK INTO THE AREA LATER SUNDAY
KEEPING THE AREA DRY INTO MONDAY.
THE UPPER FLOW WILL TRANSITION TO MORE ZONAL BY TUESDAY/WEDNESDAY.
SEVERAL SHORTWAVES WILL AFFECT THE AREA DURING THIS PERIOD BRINGING
CHANCES FOR SHOWERS/STORMS. THE MODELS START TO DIVERGE
TUESDAY/WEDNESDAY WITH TIMING AND STRENGTH ISSUES OF THE INDIVIDUAL
DISTURBANCES. CONFIDENCE DROPS TO BELOW AVERAGE BY EARLY NEXT WEEK.
EXPECT HIGHS TO REACH THE UPPER SIXTIES TO MID SEVENTIES ON SATURDAY
AHEAD OF THE COLD FRONT...THEN DROP TO AROUND 60 OVER OUR FAR
NORTHERN CWA...TO THE MID SIXTIES SOUTH. TEMPERATURES WILL THEN
SLOWLY WARM BACK TO THE UPPER SIXTIES TO MID SEVENTIES BY
WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 635 AM CDT THU SEP 12 2013
IFR AND MVFR CEILINGS COVERED MUCH OF THE NORTHEASTERN HALF OF THE
NORTHLAND EARLY THIS MORNING. THESE CEILINGS WERE MOVING WEST AND
SOUTH...BUT THERE ARE BREAKS AS WELL. MORE MID LEVEL CEILINGS WERE
MOVING SOUTHEAST INTO NORTHERN MINNESOTA. THE RAP WAS DOING AN
FAIR JOB AT DEPICTING THESE CEILINGS THIS MORNING...AND DOES
INDICATE THEY WILL STICK AROUND UNTIL 17-19Z...ALTHOUGH BASES
SHOULD SLOWLY RISE. IN ADDITION TO THE CLOUDS ALREADY COVERING THE
NORTHLAND...WE SHOULD SEE SOME CU DEVELOP WITH HEATING. BASES
SHOULD BE VFR THOUGH.
HIGH PRESSURE TONIGHT WILL CAUSE MUCH OF THE CLOUDS TO DISSIPATE.
THE EXCEPTION MAY BE ALONG THE SOUTH SHORE WHICH COULD SEE LAKE
CLOUDS DEVELOP DUE TO COLD AIR FLOWING OVER THE WARMER WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 65 38 63 46 / 0 0 0 0
INL 63 32 68 48 / 0 0 0 0
BRD 69 38 69 47 / 0 0 0 0
HYR 66 35 67 41 / 0 0 0 0
ASX 63 40 63 46 / 10 10 0 0
&&
.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.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...GROCHOCINSKI
SHORT TERM...STEWART
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
943 AM CDT THU SEP 12 2013
.UPDATE...
ISSUED AT 943 AM CDT THU SEP 12 2013
UPDATED THE FORECAST THROUGH THIS EVENING TO REFLECT THE LATEST
CLOUD AND TEMPERATURE TRENDS. IT APPEARS THERE WILL BE WIDESPREAD
PARTLY TO MOSTLY CLOUDY SKIES TODAY DUE TO THE COOL NORTHERLY FLOW
BRINGING LOW LEVEL LEVEL MOISTURE FROM CANADA. THERE IS PLENTY OF
CLOUDS UPSTREAM. I SLIGHTLY LOWERED THE TEMPERATURE FORECAST BASED
ON A WIDE BLEND OF NEWER MODEL GUIDANCE...AND I THINK THIS
REFLECTS THE CLOUD COVER AND COOL NORTHERLY FLOW WELL.
THERE SHOULD BE SOME CLEARING VERY LATE THIS AFTERNOON AND EARLY
THIS EVENING...BUT I HAVE SOME CONCERNS ON WHETHER IT WILL LINGER.
FURTHERMORE...IF THE CLOUDS LINGER...IT COULD PREVENT PARTS OF THE
FORECAST AREA FROM GETTING AS COLD AS CURRENTLY ADVERTISED...AND
THIS IN TURN COULD AFFECT OUR CURRENT HEADLINES FOR FROST AND
FREEZING TEMPERATURES. I WILL LOOK MORE INTO THIS LATER THIS
MORNING WHEN MOST OF THE 12Z MODEL GUIDANCE IS IN.
UPDATE ISSUED AT 716 CDT THU SEP 12 2013
UPDATED THIS MORNING TO INCREASE CLOUD COVER FOR STRATUS STREAMING
SOUTHEAST FROM SOUTHERN CANADA. THESE CLOUDS WILL DECREASE IN
COVERAGE BY MIDDAY.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 303 AM CDT THU SEP 12 2013
CONCERN FOR SHORT TERM IS FROST/FREEZE TONIGHT ACROSS CURRENT
FREEZE WATCH AREA.
CURRENT SURFACE ANALYSIS INDICATE SOME CLOUDS OVER THE ARROWHEAD
AND ACROSS PORTION FOR NORTHWEST WISCONSIN. THE CLOUDS SHOULD MOVE
SOUTH AND EAST OF THE FORECAST AREA BY MID-MORNING. NORTHWEST
FLOW WILL CONTINUE ACROSS THE REGION TO DAY AS THE RIDGE SLOWLY
DRIFTS EAST. THERE WILL BE SOME CU DEVELOPMENT LATE THIS MORNING AS
INDICATED BY THE CU RULE. THE CENTER OF THE RIDGE WILL BE OVER NE
MN TONIGHT. THIS WILL CAUSE LIGHT WINDS AND CLEAR SKIES ALLOWING
THE TEMPS TO DROP DOWN TO NEAR AND BELOW THE FREEZING LEVEL ACROSS
PORTIONS OF KOOCHICHING...ST. LOUIS...AND INLAND AREAS OF THE
ARROWHEAD. WILL PUT UP A FREEZE WARNING FOR NORTHERN/CENTRAL ST.
LOUIS AND INLAND LAKE AND COOK COUNTIES AND A FROST ADVISORY FOR
KOOCHICHING COUNTY. IT LOOKS THERE MAY BE A WEAK SOUTHERLY FLOW
OVER KOOCHICHING COUNTY SO TEMPS MAY NOT GET AS LOW. THE CENTER OF
THE RIDGE WILL CONTINUE TO MOVE EAST ON FRIDAY GIVING THE REGION
A MOSTLY SUNNY DAY
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 303 AM CDT THU SEP 12 2013
FRIDAY NIGHT THROUGH WEDNESDAY.
THE NORTHLAND WILL BE UNDER THE INFLUENCE OF AN UPPER RIDGE AND
DEPARTING SURFACE HIGH FRIDAY NIGHT...WITH DRY CONDITIONS EXPECTED.
A COLD FRONT...SURFACE LOW AND UPPER SHORTWAVE WILL ALL IMPACT THE
AREA SATURDAY AND SATURDAY NIGHT...POSSIBLY INTO SUNDAY AS WELL.
THESE FEATURES WILL BRING A CHANCE FOR SHOWERS AND A FEW
THUNDERSTORMS TO THE NORTHLAND...BUT SIGNIFICANT RAINFALL DOES NOT
LOOK LIKELY AT THIS TIME.
HIGH PRESSURE WILL THEN BUILD BACK INTO THE AREA LATER SUNDAY
KEEPING THE AREA DRY INTO MONDAY.
THE UPPER FLOW WILL TRANSITION TO MORE ZONAL BY TUESDAY/WEDNESDAY.
SEVERAL SHORTWAVES WILL AFFECT THE AREA DURING THIS PERIOD BRINGING
CHANCES FOR SHOWERS/STORMS. THE MODELS START TO DIVERGE
TUESDAY/WEDNESDAY WITH TIMING AND STRENGTH ISSUES OF THE INDIVIDUAL
DISTURBANCES. CONFIDENCE DROPS TO BELOW AVERAGE BY EARLY NEXT WEEK.
EXPECT HIGHS TO REACH THE UPPER SIXTIES TO MID SEVENTIES ON SATURDAY
AHEAD OF THE COLD FRONT...THEN DROP TO AROUND 60 OVER OUR FAR
NORTHERN CWA...TO THE MID SIXTIES SOUTH. TEMPERATURES WILL THEN
SLOWLY WARM BACK TO THE UPPER SIXTIES TO MID SEVENTIES BY WEDNESDAY.
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT
1236 AM CDT THU SEP 12 2013
AREAS OF FOG WILL BRING PERIODS OF IFR/LIFR CONDITIONS TONIGHT. HAVE
INCLUDED TEMPOS FOR REDUCED VSBYS AT ALL TAF LOCATIONS THROUGH
SUNRISE. NORTHWEST WINDS WILL BECOME GUSTY AROUND 20 KT THURSDAY
AFTERNOON.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 635 AM CDT THU SEP 12 2013
IFR AND MVFR CEILINGS COVERED MUCH OF THE NORTHEASTERN HALF OF THE
NORTHLAND EARLY THIS MORNING. THESE CEILINGS WERE MOVING WEST AND
SOUTH...BUT THERE ARE BREAKS AS WELL. MORE MID LEVEL CEILINGS WERE
MOVING SOUTHEAST INTO NORTHERN MINNESOTA. THE RAP WAS DOING AN
FAIR JOB AT DEPICTING THESE CEILINGS THIS MORNING...AND DOES
INDICATE THEY WILL STICK AROUND UNTIL 17-19Z...ALTHOUGH BASES
SHOULD SLOWLY RISE. IN ADDITION TO THE CLOUDS ALREADY COVERING THE
NORTHLAND...WE SHOULD SEE SOME CU DEVELOP WITH HEATING. BASES
SHOULD BE VFR THOUGH.
HIGH PRESSURE TONIGHT WILL CAUSE MUCH OF THE CLOUDS TO DISSIPATE.
THE EXCEPTION MAY BE ALONG THE SOUTH SHORE WHICH COULD SEE LAKE
CLOUDS DEVELOP DUE TO COLD AIR FLOWING OVER THE WARMER WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 65 38 63 46 / 0 0 0 0
INL 63 32 68 48 / 0 0 0 0
BRD 69 38 69 47 / 0 0 0 0
HYR 66 35 67 41 / 0 0 0 0
ASX 63 40 63 46 / 10 10 0 0
&&
.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.
WI...NONE.
LS...NONE.
&&
$$
UPDATE...GROCHOCINSKI
SHORT TERM...STEWART
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
637 AM CDT THU SEP 12 2013
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 303 AM CDT THU SEP 12 2013
CONCERN FOR SHORT TERM IS FROST/FREEZE TONIGHT ACROSS CURRENT
FREEZE WATCH AREA.
CURRENT SURFACE ANALYSIS INDICATE SOME CLOUDS OVER THE ARROWHEAD
AND ACROSS PORTION FOR NORTHWEST WISCONSIN. THE CLOUDS SHOULD MOVE
SOUTH AND EAST OF THE FORECAST AREA BY MID-MORNING. NORTHWEST
FLOW WILL CONTINUE ACROSS THE REGION TO DAY AS THE RIDGE SLOWLY
DRIFTS EAST. THERE WILL BE SOME CU DEVELOPMENT LATE THIS MORNING AS
INDICATED BY THE CU RULE. THE CENTER OF THE RIDGE WILL BE OVER NE
MN TONIGHT. THIS WILL CAUSE LIGHT WINDS AND CLEAR SKIES ALLOWING
THE TEMPS TO DROP DOWN TO NEAR AND BELOW THE FREEZING LEVEL ACROSS
PORTIONS OF KOOCHICHING...ST. LOUIS...AND INLAND AREAS OF THE
ARROWHEAD. WILL PUT UP A FREEZE WARNING FOR NORTHERN/CENTRAL ST.
LOUIS AND INLAND LAKE AND COOK COUNTIES AND A FROST ADVISORY FOR
KOOCHICHING COUNTY. IT LOOKS THERE MAY BE A WEAK SOUTHERLY FLOW
OVER KOOCHICHING COUNTY SO TEMPS MAY NOT GET AS LOW. THE CENTER OF
THE RIDGE WILL CONTINUE TO MOVE EAST ON FRIDAY GIVING THE REGION
A MOSTLY SUNNY DAY
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 303 AM CDT THU SEP 12 2013
FRIDAY NIGHT THROUGH WEDNESDAY.
THE NORTHLAND WILL BE UNDER THE INFLUENCE OF AN UPPER RIDGE AND
DEPARTING SURFACE HIGH FRIDAY NIGHT...WITH DRY CONDITIONS EXPECTED.
A COLD FRONT...SURFACE LOW AND UPPER SHORTWAVE WILL ALL IMPACT THE
AREA SATURDAY AND SATURDAY NIGHT...POSSIBLY INTO SUNDAY AS WELL.
THESE FEATURES WILL BRING A CHANCE FOR SHOWERS AND A FEW
THUNDERSTORMS TO THE NORTHLAND...BUT SIGNIFICANT RAINFALL DOES NOT
LOOK LIKELY AT THIS TIME.
HIGH PRESSURE WILL THEN BUILD BACK INTO THE AREA LATER SUNDAY
KEEPING THE AREA DRY INTO MONDAY.
THE UPPER FLOW WILL TRANSITION TO MORE ZONAL BY TUESDAY/WEDNESDAY.
SEVERAL SHORTWAVES WILL AFFECT THE AREA DURING THIS PERIOD BRINGING
CHANCES FOR SHOWERS/STORMS. THE MODELS START TO DIVERGE
TUESDAY/WEDNESDAY WITH TIMING AND STRENGTH ISSUES OF THE INDIVIDUAL
DISTURBANCES. CONFIDENCE DROPS TO BELOW AVERAGE BY EARLY NEXT WEEK.
EXPECT HIGHS TO REACH THE UPPER SIXTIES TO MID SEVENTIES ON SATURDAY
AHEAD OF THE COLD FRONT...THEN DROP TO AROUND 60 OVER OUR FAR
NORTHERN CWA...TO THE MID SIXTIES SOUTH. TEMPERATURES WILL THEN
SLOWLY WARM BACK TO THE UPPER SIXTIES TO MID SEVENTIES BY WEDNESDAY.
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT) ISSUED AT
1236 AM CDT THU SEP 12 2013
AREAS OF FOG WILL BRING PERIODS OF IFR/LIFR CONDITIONS TONIGHT. HAVE
INCLUDED TEMPOS FOR REDUCED VSBYS AT ALL TAF LOCATIONS THROUGH
SUNRISE. NORTHWEST WINDS WILL BECOME GUSTY AROUND 20 KT THURSDAY
AFTERNOON.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 635 AM CDT THU SEP 12 2013
IFR AND MVFR CEILINGS COVERED MUCH OF THE NORTHEASTERN HALF OF THE
NORTHLAND EARLY THIS MORNING. THESE CEILINGS WERE MOVING WEST AND
SOUTH...BUT THERE ARE BREAKS AS WELL. MORE MID LEVEL CEILINGS WERE
MOVING SOUTHEAST INTO NORTHERN MINNESOTA. THE RAP WAS DOING AN
FAIR JOB AT DEPICTING THESE CEILINGS THIS MORNING...AND DOES
INDICATE THEY WILL STICK AROUND UNTIL 17-19Z...ALTHOUGH BASES
SHOULD SLOWLY RISE. IN ADDITION TO THE CLOUDS ALREADY COVERING THE
NORTHLAND...WE SHOULD SEE SOME CU DEVELOP WITH HEATING. BASES
SHOULD BE VFR THOUGH.
HIGH PRESSURE TONIGHT WILL CAUSE MUCH OF THE CLOUDS TO DISSIPATE.
THE EXCEPTION MAY BE ALONG THE SOUTH SHORE WHICH COULD SEE LAKE
CLOUDS DEVELOP DUE TO COLD AIR FLOWING OVER THE WARMER WATERS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 65 38 63 46 / 0 0 0 0
INL 63 32 68 48 / 0 0 0 0
BRD 69 38 69 47 / 0 0 0 0
HYR 67 35 67 41 / 10 0 0 0
ASX 64 40 63 46 / 10 10 0 0
&&
.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.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...STEWART
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1051 AM CDT Thu Sep 12 2013
.UPDATE:
Issued at 1051 AM CDT Thu Sep 12 2013
Band of showers and scattered thunderstorms have diminished as
they have slowly moved south this morning. This is in response to
subsidence moving in behind upper trough now moving through the
Great Lakes. There will still be enough instability and low level
moisture convergence to keep isolated thunderstorms and scattered
showers going through mid afternoon.
Otherwise, surface analysis shows three fronts late this morning.
There is a quasi-stationary front over the southern CWA, a cold
front entering the northern CWA that has much cooler and drier air
behind it, and and third cold front over the upper Midwest. These
fronts will progress southward allowing the cooler and drier
airmass to move southward through tonight.
Britt
&&
.SHORT TERM: (Through Late This Afternoon)
Issued at 314 AM CDT Thu Sep 12 2013
Frontal boundary making very slow progress to the south across
forecast area early this morning. Thus post frontal activity making
slow progress as well, so adjusted pops accordingly. Coverage of
activity still hard to pin down. Current HRRR run continues to
show activity diminishing over the next several hours across
northern MO and central IL, before refiring late this morning/early
this afternoon closer to I-70 corridor, then slide south. So timed
pops similar to this scenario. Still looks like front and pcpn to
exit by sunset. Otherwise, this is a transition day with highs
still above normal in the mid to upper 80s.
Byrd
.LONG TERM: (Tonight through Wednesday)
Issued at 314 AM CDT Thu Sep 12 2013
By tonight, surface ridge to build in bringing cooler and drier
weather for Friday and Saturday. Tonight`s lows will be in the low
50s to low 60s. Highs will be in the 70s on Friday and Saturday with
lows between 45 and 50 Friday night and in the 50s Saturday night.
Saturday night ridge begins to move off to the east allowing
southerly flow to return once again. Next weather system approaches
area as well with front moving into northern MO by Sunday. Timing
and coverage hard to pin down, so will just keep chance pops going
for northern portions of forecast area Sunday. Pcpn to move a bit
further south Sunday night, but coverage to remain scattered and
mainly along and north of I-70.
Front to remain stalled out over forecast area, wavering back and
forth. So trying to pin down pcpn chances hard to do, so will just
have chance pops for portions of the area through the rest of the
forecast period. Though best chances appear to be on Wednesday for
most of the forecast area.
As for temperatures, to remain at or just below normal Sunday
through next Wednesday.
Byrd
&&
.AVIATION: (For the 12z TAFs through 12z Friday Morning)
Issued at 637 AM CDT Thu Sep 12 2013
The initial cold front is moving through the St. Louis area at
this time with scattered showers along and just ahead of it. These
showers are small in terms of size and shouldn`t create any long
lasting impacts but could briefly reduce the vsbys to 3-5sm. There
also could be an isolated thunderstorm but I believe that will be
south of the terminals. The area of rain and isolated embedded
thunderstorms across northeast Missouri into west Central Illinois
is occurring ahead of a second cold front and is moving to the
east and shrinking. I don`t believe it will bodily make it down to
KCOU or KSTL/KSUS/KCPS but there could be some new spotty showers.
Otherwise VFR conditions will dominate. The secondary cold front
will push through the area by noon with n/nw winds aoa 10 kts and
diminishing cloud cover.
Specifics for KSTL:
The initial cold front is moving through the St. Louis area at
this time with scattered showers along and just ahead of it. These
showers are small in terms of size and shouldn`t create any long
lasting impacts but could briefly reduce the vsbys to 3-5sm. I
think any thunder threat will be to the south of the terminal.
A few showers will remain possible after this initial batch until
a second cold front pushes through from 17-18z. N/NW winds aoa 10
kts are expected this afternoon with diminishing cloud cover.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
652 AM CDT Thu Sep 12 2013
.SHORT TERM: (Through Late This Afternoon)
Issued at 314 AM CDT Thu Sep 12 2013
Frontal boundary making very slow progress to the south across
forecast area early this morning. Thus post frontal activity making
slow progress as well, so adjusted pops accordingly. Coverage of
activity still hard to pin down. Current HRRR run continues to
show activity diminishing over the next several hours across
northern MO and central IL, before refiring late this morning/early
this afternoon closer to I-70 corridor, then slide south. So timed
pops similar to this scenario. Still looks like front and pcpn to
exit by sunset. Otherwise, this is a transition day with highs
still above normal in the mid to upper 80s.
Byrd
.LONG TERM: (Tonight through Wednesday)
Issued at 314 AM CDT Thu Sep 12 2013
By tonight, surface ridge to build in bringing cooler and drier
weather for Friday and Saturday. Tonight`s lows will be in the low
50s to low 60s. Highs will be in the 70s on Friday and Saturday with
lows between 45 and 50 Friday night and in the 50s Saturday night.
Saturday night ridge begins to move off to the east allowing
southerly flow to return once again. Next weather system approaches
area as well with front moving into northern MO by Sunday. Timing
and coverage hard to pin down, so will just keep chance pops going
for northern portions of forecast area Sunday. Pcpn to move a bit
further south Sunday night, but coverage to remain scattered and
mainly along and north of I-70.
Front to remain stalled out over forecast area, wavering back and
forth. So trying to pin down pcpn chances hard to do, so will just
have chance pops for portions of the area through the rest of the
forecast period. Though best chances appear to be on Wednesday for
most of the forecast area.
As for temperatures, to remain at or just below normal Sunday
through next Wednesday.
Byrd
&&
.AVIATION: (For the 12z TAFs through 12z Friday Morning)
Issued at 637 AM CDT Thu Sep 12 2013
The initial cold front is moving through the St. Louis area at
this time with scattered showers along and just ahead of it. These
showers are small in terms of size and shouldn`t create any long
lasting impacts but could briefly reduce the vsbys to 3-5sm. There
also could be an isolated thunderstorm but I believe that will be
south of the terminals. The area of rain and isolated embedded
thunderstorms across northeast Missouri into west Central Illinois
is occurring ahead of a second cold front and is moving to the
east and shrinking. I don`t believe it will bodily make it down to
KCOU or KSTL/KSUS/KCPS but there could be some new spotty showers.
Otherwise VFR conditions will dominate. The secondary cold front
will push through the area by noon with n/nw winds aoa 10 kts and
diminishing cloud cover.
Specifics for KSTL:
The initial cold front is moving through the St. Louis area at
this time with scattered showers along and just ahead of it. These
showers are small in terms of size and shouldn`t create any long
lasting impacts but could briefly reduce the vsbys to 3-5sm. I
think any thunder threat will be to the south of the terminal.
A few showers will remain possible after this initial batch until
a second cold front pushes through from 17-18z. N/NW winds aoa 10
kts are expected this afternoon with diminishing cloud cover.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1113 AM EDT THU SEP 12 2013
.SYNOPSIS...
THE UNSEASONABLY WARM AND HUMID CONDITIONS OF THE PAST FEW DAYS
WILL END LATER TODAY AS A STRONG COLD FRONT CROSSES THE REGION.
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL OCCUR THROUGH
LATE THIS AFTERNOON...AND SOME MAY PRODUCE STRONG TO LOCALLY
DAMAGING WIND GUSTS AND HAIL. ANOTHER TASTE OF FALL WILL ARRIVE IN
THE WAKE OF THIS FRONT. BELOW NORMAL TEMPERATURES ARE EXPECTED
FROM FRIDAY INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
80S IN THE SC MTS SHOULD CONTINUE TO HEAT UP AS THE SKY HAS
CLEARED NICELY. EARLY CONVECTION IS NOW ALMOST OUT OF LANCASTER
COUNTY. THE HEATING SHOULD PUMP THE CAPES UP TO LEVELS JUST SHY OF
WED NUMBERS - BUT STILL WELL ABOVE 1500J/KG. FIRST COLD FRONT
WITH WIND SHIFT AND SLIGHT DIP IN DEW POINTS IS NOW ALMOST TO LAKE
ERIE...BUT PRECIP OUT AHEAD OF THE FRONT ALONG A MOISTURE BOUNDARY
WILL CONTINUE TO SLIDE EAST AND TINY CELLS ALREADY DEVELOPING IN
A PSEUDO-LINE JUST EAST OF THAT SHIELD OF RAIN. THESE CELLS ARE
ROUGHLY IN LINE WITH THE CONVECTION IN OH AND SHOULD CONGEAL INTO
A BIGGER AND MORE-COHERENT LINE OF STORMS SHORTLY. HRRR AND RUC
ARE IN AGREEMENT WITH THE GOING FCST ON TIMING. THEY DO INDICATE A
SECONDARY LINE -JUST BEHIND THE FIRST BY 30-60 MINS...BUT THIS IS
WAY TOO CUTE TO TRY AND PAINT IN 1 HR POP GRIDS. SO...WILL HOLD
THE LINE WITH THAT AND JUST KNOCK THE POPS A LITTLE HIGHER OVERALL
WITH HIGHER CONFIDENCE NOW VS EARLIER. SEVERITY OF THE STORMS IS
STILL LIKELY. SLIGHT RISK WAS EXPANDED EARLIER BY SPC - PROBABLY
WITH AN EYE TO TIMING AND CLEARING THAT IS OCCURRING. THE STORMS
SHOULD BE THROUGH IPT/UNV/AOO BEFORE SUNSET...AND OUT OF MDT/LNS
BY 9 PM. SOME SHOWERS MAY LINGER ALONG THE FAR EAST AND FAR SRN
TIER THRU MIDNIGHT...BUT THESE SHOULD BE WELL BEHIND THE BEST
MOISTURE AND HEATING.
&&
.SHORT TERM /9 PM THIS EVENING THROUGH 6 PM FRIDAY/...
5H TROF AXIS SWINGS ACROSS THE CENTRAL AND ERN GLAKS TONIGHT AND
SHARPENS AND SLOWS WHILE TRAVERSING CENTRAL PA ON FRIDAY AFTERNOON.
STRONG COLD ADVECTION AND MUCH DRIER AIR MASS REACHES INTO WESTERN
AND CENTRAL AREAS DURING THE AFTERNOON. SHOWERS WILL STILL BE
POSSIBLE IN THE TYPICAL NORTHWEST FLOW REGIME (FROM THE LAURELS
THROUGH THE NORTHWEST MOUNTAINS AND NORTHERN TIER COUNTIES)...BUT
QPF WILL BE LIGHT. AS PREVIOUSLY ADVERTISED...HIGHS ON FRIDAY WILL
STRUGGLE TO REACH THE MID TO UPPER 50S ACROSS THE NORTHWEST...
WITH LOWER TO MIDDLE 60S COMMON FOR HIGHS FROM THE CENTRAL
MOUNTAINS TO THE MIDDLE SUSQ RIVER VALLEY. THE SOUTH CENTRAL
MOUNTAINS AND LOWER SUSQ SHOULD SEE MAXES NEAR OR SLIGHTLY ABOVE
70F FRIDAY AFTERNOON...A FAR CRY FROM THE LOWER 90S SEEN TUESDAY
AND WEDNESDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
THE MAIN STORY OF THE EXTENDED IS A RETURN TO AUTUMN AS TEMPERATURES
DROP BACK TO WELL BELOW NORMAL LEVELS. EXPECTING A MUCH COOLER
WEEKEND WITH TEMPERATURES FROM THE MID 60S ON SATURDAY...TO LOW
70S ON SUNDAY.
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 THURSDAY THROUGH MONDAY/...
ARRIVAL OF A POTENT COLD FRONT IN BFD SHOULD BE LATE THIS
AFTN...AND INTO THE SERN TERMINALS BY MIDNIGHT. HOWEVER...THE MAIN
TIMING OF STORMS SHOULD BE ABOUT 3-4 HRS AHEAD OF THIS TIME. THESE
STORMS ARE INTO BFD AND WILL EXIT THE LOWER SUSQ VALLEY ABOUT 00Z-
01Z. EXPECT THIS BOUNDARY TO BE CONVECTIVELY ACTIVE AND RELATIVELY
WELL-ORGANIZED AS IT CROSSES THE AIRSPACE...WITH THE POTENTIAL
FOR STRONG TO SEVERE TSTORM WIND GUSTS AND BRIEF IFR VSBY/CIG
REDUCTIONS.
COOLER AND DRIER AIR WILL BEGIN TO WORK IN BEHIND THE COLD FRONT
TONIGHT. HOWEVER...LINGERING LOW LEVEL MOISTURE FORCED TO ASCEND
THE ALLEGHENY MTNS WILL PROBABLY PRODUCE SOME IFR CIGS AT BFD AND
JST. SHORT BUT INTENSE CONVECTION IS POSSIBLE ON FRI - MAINLY IN
THE AFTN AS THE COLDEST AIR ALOFT CROSSES THE AREA. THE MOST
LIKELY TERMINALS WHICH MIGHT SEE SOME IMPACT WILL BE JST AND BFD.
WINDS WILL MOST LIKELY PICK UP AND GUST INTO THE 20-25KT RANGE IN
THE AFTN.
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.
&&
$$
SYNOPSIS...DANGELO/DEVOIR
NEAR TERM...DANGELO
SHORT TERM...DANGELO/DEVOIR
LONG TERM...CERU
AVIATION...DANGELO/FITZGERALD
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
947 AM EDT THU SEP 12 2013
.DISCUSSION...CONVECTION GETTING AN EARLY START AHEAD OF THE COLD
FRONT THIS MORNING...ESPECIALLY OVER NE TN AND IN THE SMOKIES. 12Z
UNMODIFIED OHX/RNK SOUNDINGS SHOW INSTABILITY OF 2500 TO 3000 J/KG.
WINDS ALOFT STILL VERY LIGHT AND ERRATIC...ALTHOUGH STORM MOTION OF
SE AT 10 MPH WILL BE A BIT FASTER THAN YESTERDAY. WINDS MIGHT
INCREASE IN THE EVENING...BUT SEVERE THREAT LOOKS LIMITED TO GUSTY
WINDS AND LOCALLY HEAVY RAINS AT THIS POINT...ALTHO STRONGEST STORMS
COULD PRODUCE HAIL. PRECIPITABLE WATER VALUES UP TO NEAR 1.75
INCHES.
13Z SURFACE ANALYSIS PLACED COLD FRONT FROM NEAR PADUCAH KY NE INTO
EXTREME SRN IL AND SW IN. RUC AND NAM12 KM SUPPORT LIKELY POPS THIS
AFTERNOON OVER NRN PARTS OF THE FORECAST AREA...AND ALSO IN THE
FOOTHILLS AND SMOKY MTNS. MAY TWEAK POPS UP IN A FEW LOCATIONS.
TEMPS RUNNING CLOSE TO FORECAST GRIDS FOR NOW...BUT EARLY ONSET OF
CONVECTION MAY AFFECT MAX TEMPS. WILL FRESHEN GRIDS AND PRODUCTS
AROUND 11 AM EDT.
SOME GREAT WEATHER STARTING FRIDAY RIGHT THROUGH THE WEEKEND!
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 91 68 87 57 80 / 20 50 10 0 0
KNOXVILLE MCGHEE TYSON AIRPORT, TN 89 66 82 54 77 / 40 50 10 0 0
OAK RIDGE, TN 89 65 82 53 77 / 40 50 10 0 0
TRI CITIES AIRPORT, TN 87 61 77 48 76 / 60 40 10 0 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
TG
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
640 AM CDT THU SEP 12 2013
.DISCUSSION...UPDATED FOR 12Z AVIATION.
&&
.AVIATION...MVFR VISIBILITIES CONTINUE AT ALI/VCT THIS MORNING
ALONG WITH INTERMITTENT MVFR CEILINGS AT LRD. ALSO...ISOLATED
SHOWERS HAVE DEVELOPED THIS MORNING AND WILL OCCASIONALLY APPROACH
THE CRP/ALI TERMINALS. INCLUDED VCSH REMARKS FOR NOW AS CONFIDENCE
IS LOW AS TO WHETHER THESE SHOWERS WILL DIRECTLY IMPACT THE
TERMINALS. LIGHT AND VARIABLE WINDS THIS MORNING WILL BECOME
EASTERLY AND EAST SOUTHEASTERLY THIS AFTERNOON...WITH A FEW GUSTS
BETWEEN 18 AND 20 KNOTS AT ALI/VCT/CRP. LIGHT WINDS WILL DEVELOP
AGAIN TONIGHT AND SUFFICIENT LL MOISTURE MAY CONTRIBUTE TO PATCHY
FOG DEVELOPING. ANOTHER ROUND OF MVFR VSBYS/POSSIBLE LOWER WILL BE
POSSIBLE AT ALI/VCT AFTER 06Z.
&&
.PREV DISCUSSION... /ISSUED 426 AM CDT THU SEP 12 2013/
SHORT TERM (TODAY THROUGH FRIDAY)...ISOLATED SHOWERS CONTINUE
EARLY THIS MORNING OVER SOME INLAND LOCATIONS BUT MOSTLY OVER THE
GULF WATERS. WITH THAT...HAVE SOME CONCERNS THAT CONDITIONS ARE
NOT DRYING OUT AS MUCH AS THE NAM HAS BEEN ADVERTISING THE LAST
SEVERAL DAYS. WILL KEEP 20 POPS TODAY FOR MOST OF THE AREA DESPITE
UPPER RIDGE MOVING BACK A BIT FURTHER TO THE WEST. LATEST RUNS OF
THE HRRR SUPPORT AT LEAST LOW END SHOWER/THUNDERSTORM CHANCES...
BUT COVERAGE SHOULD BE LESS THAN THE PAST FEW DAYS. EXPECT MOSTLY
LOWER 90S TODAY FOR AFTERNOON HIGHS...WITH A FEW SPOTS OUT WEST
PERHAPS CLIMBING INTO THE MIDDLE 90S. ANY CONVECTION THAT DEVELOPS
SHOULD DIMINISH WITH THE LOSS OF DAYTIME HEATING THIS EVENING.
MODELS PROG DEEPER MOISTURE RETURNING FROM THE SOUTH AND SOUTHEAST
ON FRIDAY. THIS WILL RESULT IN BETTER CHANCES OF SHOWERS AND
THUNDERSTORMS ACROSS THE SOUTHERN HALF OF THE REGION.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...UPPER RIDGING DRIES
THE MIDLEVELS...HOWEVER PLENTY OF MOISTURE REMAINS JUST ABOVE THE
SURFACE TO ALLOW FOR ISOLATED DEVELOPMENT ON SATURDAY...MAINLY
ACROSS THE SOUTHERN PORTIONS OF THE CWA. TEMPERATURES SHOULD REMAIN
JUST NEAR NORMAL EARLY IN THE EXTENDED.
ABOUT THE AREA OF LOW PRESSURE MOVING INTO THE SOUTHERN BAY OF
CAMPECHE TODAY. MODELS BEGINNING TO AGREE ON MID LEVEL CLOSED LOW
DEVELOPMENT...WITH THE CANADIAN MAINTAINING AN OPEN WAVE AS FARTHER
WESTWARD MOVEMENT OCCURS. THE HURRICANE CENTER IS LOOKING AT LIKELY
TROPICAL CYCLONE DEVELOPMENT DURING THE NEXT COUPLE OF DAYS...WITH A
60 PERCENT CHANCE OF BECOMING A TROPICAL CYCLONE WITHIN THE NEXT 48
HOURS...AND 80 PERCENT CHANCE DURING THE NEXT 5 DAYS. POSITIONING OF
THE UPPER RIDGE REMAINS ACROSS THE SOUTHERN U.S....KEEPING A GENERAL
WEST-NORTHWESTWARD FLOW WITH THIS SYSTEM...MOVING TOWARD THE MIDDLE
MEXICAN COAST. MOISTURE FROM THIS SYSTEM IS STILL EXPECTED TO AFFECT
SOUTH TEXAS BRINGING SCATTERED SHOWERS AND THUNDERSTORMS AS EARLY AS
SUNDAY THROUGH MUCH OF NEXT WEEK. IN ADDITION...AN INCREASE IN
SWELLS AND RIP CURRENT RISKS IS EXPECTED DURING THIS TIME FRAME. AS
FOR TEMPERATURES DURING THIS TIME PERIOD...TRENDED SIMILAR TO THE
PAST DAYS OF RAINFALL WITH HIGHS IN THE UPPER 80S TO NEAR 90.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 93 76 93 77 93 / 20 10 20 20 20
VICTORIA 94 73 93 74 95 / 20 10 10 10 20
LAREDO 95 74 95 77 96 / 20 10 20 20 20
ALICE 95 73 93 74 94 / 20 10 20 10 20
ROCKPORT 92 76 92 78 91 / 20 20 20 20 20
COTULLA 95 72 97 74 97 / 10 10 10 10 20
KINGSVILLE 94 74 93 75 94 / 20 10 20 20 20
NAVY CORPUS 90 78 90 78 90 / 20 20 20 20 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TB/78...AVIATION
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1043 AM CDT THU SEP 12 2013
.UPDATE...COLD ADVECTION ALOFT WILL CONTINUE THIS AFTERNOON WITH
32 UNIT ELONGATED VORT SLIDING SEWD FROM NE MN. SURFACE TROUGH
AXIS EXTENDS NW INTO SE WI FROM WK LOW PRES OVER SRN LAKE MI. NST
PARAMETER ON THE STRONG SIDE. SFC-3KM CAPE AROUND 150 J/KG...WHICH
IS ALSO FAVORABLE. HRRR AND OTHER MODELS SHOW SHRA DEVELOPMENT THIS
AFTERNOON. CERTAINLY SOME POTENTIAL FOR FUNNEL CLOUD DEVELOPMENT
AS A LOT OF PARAMETERS FOCUSING ACROSS THE ERN 1/2 OF THE CWA.
PC
&&
.AVIATION/18Z TAFS/...SURFACE TROUGH EXTENDS INTO SE WI FROM WEAK
LOW PRESSURE OVER SE LAKE MI. PLENTY OF CONVERGENCE AND LOW LEVEL
CAPE TO WARRANT SOME CONCERN FOR FUNNEL CLOUD DEVELOPMENT THIS
AFTERNOON WITH ANY SHRA THAT FORM. EXPECTING VFR CU FILED TO FILL
IN ACROSS THE AREA THIS AFTERNOON WITH ISOLD/SCT SHRA DEVELOPMENT.
PROGS POINT TO ERN CWA A BEST POTENTIAL FOR THIS. MODELS DO SHOW
SOME INCREASE IN LOW LEVEL RH TNGT INTO FRI WITH 850 MILLIBAR COOL
POOL BECOMING MORE ENTRENCHED ACROSS THE AREA. HOWEVER MOS AND
SREF CIG PROBS NOT SHOWING MUCH POTENTIAL FOR LOWER CIGS. WITH
850/925 TRAJ SUPPORTIVE OF BRINGING ANY LAKE CLOUDS ONSHORE THINK
THERE IS POTENTIAL FOR MORE MVFR CLOUD COVER THAN WHAT MOS/SREF IS
SUGGESTING.
PC
&&
.PREV DISCUSSION... /ISSUED 403 AM CDT THU SEP 12 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM TO HIGH
COLD POOL DROPS INTO REGION WITH MID-UPPER LEVEL TROUGHS. 850 MB
TEMPS FALL 4C TO 7C BETWEEN 12Z THURSDAY AND 00Z FRIDAY OVER THE
CWA. RESULTING INSTABILITY...ALONG WITH FORCING OVER EASTERN CWA
WITH SHORT WAVE DROPPING THROUGH BACK SIDE OF TROUGH...BRINGS
POTENTIAL FOR LIGHT SHOWERS. CONVECTIVE CLOUD DEPTH LIMITED BY
SUBSIDENCE WHICH HOLDS EQUILIBRIUM LEVELS BELOW 10K FT...BUT STILL
SUFFICIENT DEPTH FOR LIGHT AFTERNOON SHOWERS.
FAIRLY DEEP MIXING IN THE WEST ALLOWS TEMPS TO REACH THE MID 70S
AROUND MIDDAY...THEN COOLING MID-LATE AFTERNOON WITH COLD AIR
ADVECTION. LOW-MID 70S EAST WITH INCREASING AFTERNOON CLOUDS AND
LIGHT PCPN.
COLD ADVECTION CONTINUES TONIGHT WITH 850 MB TEMPS ON THE COLD 00Z
NAM DIPPING TO +1C NE TO +3C SW AT 12Z FRIDAY...WITH THE GFS
HOLDING AT +3C NE AND +5C TO +6C SW...AND THE ECMWF SIDING WITH THE
NAM IN THE NE...BUT KEEPING THE SW WARMER LIKE THE GFS.
FRIDAY THROUGH SATURDAY NIGHT...FORECAST CONFIDENCE IS HIGH.
SHORT TERM MODELS IN GOOD AGREEMENT WITH FEATURES DURING THIS
PERIOD. THEY BRING HIGH PRESSURE SOUTHEAST ACROSS THE REGION
FRIDAY AND FRIDAY NIGHT...THEN TO THE SOUTHEAST ON SATURDAY. AREA
FORECAST SOUNDINGS SHOW A DRY AIRMASS IN PLACE DURING THIS TIME.
THUS...QUIET WEATHER IS EXPECTED.
COOL TEMPERATURES ARE EXPECTED FRIDAY AND FRIDAY NIGHT. 925MB
TEMPERATURES SUPPORT ONLY LOWER TO MID 60S FOR HIGHS FRIDAY...AND
LOWER TO MID 40S FOR FRIDAY NIGHT AWAY FROM THE LAKE. HIGH WARM
SLIGHTLY IN TO THE MID 60S TO AROUND 70 FOR SATURDAY.
MODELS THEN SHOW A COLD FRONT MOVING SOUTHWARD INTO NORTHERN
WISCONSIN SATURDAY NIGHT...WITH A WARM FRONT EXTENDING NORTHEAST
INTO SOUTHWEST WISCONSIN FROM THE CENTRAL PLAINS. 850MB LOW LEVEL
JET POINTS INTO SOUTHERN IOWA SATURDAY NIGHT...WITH THE BEST LOW
LEVEL WARM AIR ADVECTION IN THAT AREA AS WELL. MODELS TRY TO CLIP
THE AREA WITH QPF...AS 500MB VORTICITY MAXIMA MOVE THROUGH THE
AREA.
SOME MID LEVEL MOISTURE MOVES INTO THE REGION SATURDAY
NIGHT...WITH WEAKER WARM AIR ADVECTION. LEFT LOW POPS FOR SHOWERS
FOR SATURDAY NIGHT. WARMER LOWS IN THE 50S ARE ALSO EXPECTED.
SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE IS MEDIUM.
GFS/ECMWF IN SOME AGREEMENT WITH FEATURES DURING THIS PERIOD. THEY
BRING THE COLD FRONT SOUTHWARD THROUGH THE AREA SUNDAY...WITH THE
QPF REMAINING MAINLY SOUTH OF THE AREA. 500MB VORTICITY MAXIMUM
DOES CLIP THE AREA IN THE MORNING. LEFT LOWER END POPS FOR SUNDAY
FOR NOW.
HIGH PRESSURE MOVING SOUTHEAST THROUGH AND EAST OF THE REGION
SHOULD BRING QUIET WEATHER WITH COOL TEMPERATURES. MODELS CONTINUE
TO DIFFER WITH LOW PRESSURE AND TIMING OF QPF TUESDAY INTO
WEDNESDAY...SO WENT WITH CONSENSUS POPS AND TEMPERATURES FOR NOW.
A GENERAL WARMING TREND IS EXPECTED WITH WARM AIR ADVECTION TAKING
HOLD OF THE REGION.
AVIATION/12Z TAFS/...
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. EASTERN TAF SITES WILL
SEE AN INCREASE IN CLOUDS THIS AFTERNOON BUT WILL HOLD BETWEEN 4K
AND 5K FT. SOME INSTABILITY SHOWERS ENHANCED BY LIFT FROM PASSING
DISTURBANCE COULD AFFECT THE EASTERN SITES THIS AFTERNOON...AND KMKE
AND KENW INTO THE EARLY EVENING...BUT CHANCE TOO LOW TO MENTION. IF
THEY DO OCCUR SHOULD NOT BE ENOUGH TO DROP VSBYS TO MVFR.
MARINE...
MOVED UP TIMING ON SMALL CRAFT ADVISORY AS WINDS TURN NORTHERLY BY
18Z AND INCREASE THROUGH THE AFTERNOON. THIS SHOULD BUILD WAVES
MEETING CRITERIA BY MID-AFTERNOON. WILL KEEP MENTION OF WATERSPOUTS
DURING THE AFTERNOON AND EVENING. MODEL SOUNDINGS SHOW SFC TO 850 MB
TEMP DIFFERENCES MAX BETWEEN 10-15C...LOWER THAN PREVIOUS
RUNS...EXCEPT FOR THE COOLER NAM. LAKE INDUCED CAPE BETWEEN 400 AND
500 J/KG AND EQUILIBRIUM LEVELS PUSHING 20K FT SUPPORT KEEPING THE
MENTION FROM MID-AFTERNOON UNTIL LATE EVENING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 1 AM CDT
SATURDAY FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
FRIDAY THROUGH WEDNESDAY...WOOD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1142 AM MDT THU SEP 12 2013
.UPDATE...
ISSUED AT 1142 AM MDT THU SEP 12 2013
DISTURBANCE OVER NORTHERN NEW MEXICO IS CONTINUING TO MOVE
NORTHWARD. ALL MODELS AGREE ON INCREASING THE COVERAGE AND
INTENSITY OF PRECIPITATION WHEN THIS DISTURBANCE PASSES OVER THE
REGION. CURRENT TIMING HAS THE DISTURBANCE REACHING EL PASO COUNTY
BY MID AFTERNOON. FORECAST APPEARS TO BE IN TRACK WITH
PRECIPITATION COVERAGE AND INTENSITY INCREASING FROM SOUTH TO
NORTH DURING THE LATE MORNING AND INTO THE AFTERNOON.
THE HRRR REFLECTIVITY IS FAIRLY CLOSE TO THE OBSERVED
REFLECTIVITY WITH THE THE NEXT ROUND OF CONVECTION OVER EXTREME
NORTHERN NEW MEXICO AND SOUTHEAST COLORADO. LATEST HRRR RUN
CONTINUES TO LOOK SCARY DURING THE LATER AFTERNOON AND
EVENING...WITH WIDESPREAD MODERATE TO HEAVY RAINFALL OVER THE
REGION. WITH SOUTHERLY FLOW...GREATEST POTENTIAL FOR HEAVY
RAINFALL WILL BE OVER EL PASO AND TELLER COUNTIES WITH SOUTHERLY
FLOW BEING UPSLOPE FOR THESE LOCATIONS. WITH SCATTERED HEAVY
SHOWERS AND THUNDERSTORMS THROUGHOUT THE REGION...FLASH FLOODING
IS STILL POSSIBLE AT OTHER LOCATIONS...PARTICULARLY ON THE THE
SOUTH FACING SLOPES. --PGW--
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM MDT THU SEP 12 2013
ALL INDICATIONS ARE THAT TODAY WILL BE ANOTHER BUSY DAY WITH
POTENTIAL HEAVY RAIN AND THE THREAT OF FLASH FLOODING. LARGE UPR
LOW WL REMAIN OVR EASTERN UT THRU TODAY AND TONIGHT...SLOWLY
SHIFTING NORTHWARD. THIS WILL ALLOW THE STREAM OF MOISTURE TO
CONTINUE OVR EASTERN CO THRU THE DAY. LITTLE CHANGES WL BE MADE O
THE ONGOING FORECAST AND WL GENERALLY HAVE LIKELY POPS OVR MOST OF
THE FORECAST AREA TODAY AND TONIGHT. SHORTWAVE TROF LIFTING NORTH
TO NORTHEAST ACRS THE AREA THIS AFTERNOON WL ALSO HELP TO INITIATE
CONVECTION. ALTHOUGH MOST AREAS WL SEE LITTLE IN THE WAY OF PCPN
THIS MORNING...BY AFTERNOON THE ACTIVITY WL INCREASE AND THE MODELS
KEEP WIDESPREAD PCPN FROM THE EASTERN MTS TO THE ERN CO BORDER THRU
MUCH OF THE NIGHT AS ANOTHER DISTURBANCE LIFTS NORTHWARD ACRS THE
AREA. LOOKING AT MODEL FORECAST PCPN AMOUNTS...THE WALDO CANYON BURN
SCAR GETS ANOTHER ROUND OF HEAVY PCPN LATE IN THE EVENING AND INTO
THE EARLY MORNING HOURS FRI. CURRENTLY THERE IS A FLASH FLOOD WATCH
IN EFFECT THROUGH MIDNIGHT FOR TELLER AND EL PASO COUNTIES AND THIS
TIME-FRAME STILL LOOKS OK. AS FOR WESTERN PORTIONS OF THE FORECAST
AREA...THERE WILL BE GOOD CHANCES FOR PCPN TODAY AND THIS EVENING
BUT PROBABLY NOT QUITE AS MUCH AS ERN AREAS. THERE WL STILL BE THE
POTENTIAL FOR SOME LOCALLY HEAVY RAIN OVR WRN AREAS THAT COULD BE A
THREAT TO BURN SCARS.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 340 AM MDT THU SEP 12 2013
WILL KEEP LONG TERM DISCUSSION CONCISE DUE TO ONGOING ACTIVE
CONDITIONS. PRIMARY LONGER TERM METEOROLOGICAL MESSAGE WILL BE
CONTINUED WET CONDITIONS AT TIMES INTO THE WEEKEND WITH NEXT
NORTHERLY SURGE EXPECTED TO PRODUCE AN UPSWING IN POP ACTIVITY
AGAIN FROM SUNDAY INTO SUNDAY NIGHT. LOCALLY HEAVY RAIN AS WELL AS
FLASH FLOODING...ESPECIALLY OVER AREA BURN SCARS WILL CONTINUE TO
BE A CONCERN OVER THE CWFA INTO THE WEEKEND.
A RETURN TO WARMER AND DRIER CONDITIONS SHOULD THEN BE NOTED OVER
THE FORECAST DISTRICT BY NEXT WEEK IN COMBINATION WITH GENERALLY
LOW-GRADE GRADIENT WINDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1142 AM MDT THU SEP 12 2013
THE UPPER LEVEL LOW OVER WESTERN UTAH WILL CONTINUE TO BRING
MOISTURE INTO THE REGION.
KCOS AND KPUB...MOIST UPSLOPE FLOW WILL CONTINUE THROUGH THE
PERIOD WITH PERIODS OF RAIN AND SOME THUNDERSTORMS POSSIBLE. THE
GREATEST CHANCES FOR RAIN IS BETWEEN AROUND 21Z AND 04Z.
ANTICIPATE MOSTLY MVFR CONDITIONS WITH IFR CONDITIONS IN HEAVIER
SHOWERS.
KALS...SCATTERED SHOWERS AND THUNDERSTORMS WILL OCCUR THROUGH MID
EVENING. SOME LOCAL MVFR ARE POSSIBLE IF A STRONGER STORM MOVES
OVER THE REGION.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR COZ072>088.
&&
$$
UPDATE...PGW
AVIATION...PGW
AREA FORECAST DISCUSSION
NWS ALBANY NY
113 PM EDT THU SEP 12 2013
.SYNOPSIS...
A COLD FRONT WILL BRING ANOTHER ROUND OF STRONG TO SEVERE
THUNDERSTORMS TO EASTERN NEW YORK AND WESTERN NEW ENGLAND THIS
AFTERNOON INTO TONIGHT. SOME VERY HEAVY RAINFALL WILL ACCOMPANY
THE THUNDERSTORMS AND FRONTAL PASSAGE. AN AUTUMN AIR MASS WILL
BUILD INTO THE REGION ON FRIDAY...AND THE COOLER AND DRIER WEATHER
WILL CONTINUE INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 100 PM EDT...SEVERE THUNDERSTORMS WATCH 523 HAS BEEN ISSUED
FOR ALL OF EAST CENTRAL NEW YORK AND WESTERN NEW ENGLAND UNTIL 8
PM THIS EVENING. THE MAIN THREAT WITH THUNDERSTORMS WILL BE
DAMAGING WIND GUSTS IN EXCESS OF 58 MPH.
SEVERAL BREAKS OF SUNSHINE ACROSS MUCH OF THE AREA LATE THIS
MORNING INTO EARLY AFTERNOON HAVE RESULTED IN A BUILD-UP OF
INSTABILITY. THE LATEST SPC RAP MESOANALYSIS PAGE SHOWS AROUND
1500-2500 J/KG OF SBCAPE ACROSS THE AREA AS OF NOON. THE SPECIAL
16Z ALB SOUNDING STILL REVEALED A WEAK CAP AROUND 900 MB...BUT
THIS IS EXPECTED TO MIX OUT IN THE NEXT COUPLE HOURS AND HAS
LIKELY ALREADY DONE SO ACROSS THE HIGHER TERRAIN WHERE SOME
CONVECTION HAS STARTED TO DEVELOP.
THE MOST CONCENTRATED CONVECTIVE ACTIVITY IS ACROSS CENTRAL NY
TIED TO THE NEXT PRE-FRONTAL TROUGH AND COLD FRONT MOVING EASTWARD
INTO OUR AREA DURING THE MID TO LATE AFTERNOON. EXPECTING A
CONTINUED TREND OF INCREASING COVERAGE OF CONVECTION WITH LIKELY
TO CATEGORICAL POPS. AN UPPER JET STEAK ASSOCIATED WITH THE
LONGWAVE TROUGH ADVANCING S/SE FROM S-CNTRL ONTARIO AND THE UPPER
MIDWEST WITH HELP ENHANCE THE RAINFALL...AND THE SVR THREAT TODAY
ACROSS ERN NY AND WRN NEW ENGLAND. THE ANTICYCLONIC ENTRANCE
REGION OF A 250 HPA 100-110+ KT JET STREAK WILL MOVE ACROSS NRN
AND ERN NY IN THE AFTERNOON.
SFC DEWPTS WILL STILL BE ABOVE NORMAL FOR MID SEPT IN THE 60S TO
EVEN SOME L70S. THE MID LEVEL LAPSE RATES WILL NOT BE AS STEEP
TODAY /GENERALLY LESS THAN 6.5 C/KM/...AS THE REMNANT ELEVATED
MIXED LAYER HAS SHIFTED DOWNSTREAM. THE 0-6 KM BULK SHEAR VALUES
INCREASE TO 25-40 KTS BY MID TO LATE AFTERNOON. MODEL SOUNDINGS
INDICATE SOME MULTICELLULAR CLUSTERS MAY FORM INTO A COUPLE OF
LINES. THE BEST CHC OF A SUPERCELL MAY BE ACROSS THE SRN EXTREME
WHEN THE 0-6 KM SHEAR INCREASE TO 40 KTS AND THE SBCAPE VALUES MAY
REACH 2000 J/KG. DAMAGING WINDS LOOK TO BE THE MAIN THREAT WITH
BOWING SEGMENTS...BUT WITH TALLER UPDRAFTS SOME LARGE HAIL IS
POSSIBLE. THE BEST 850-700 HPA THETA-E LAPSE RATES IMPACT
LOCATIONS FROM THE CAPITAL REGION SOUTH AND EAST TOWARDS
NIGHTFALL.
THE LATEST 3KM HRRR AND LOCAL HIRES WRF SHOWS A BROKEN LINE OF
SHOWERS/THUNDERSTORMS MOVING ACROSS THE REGION THIS AFTN INTO THIS
EVENING. THIS MAKES SENSE CONSIDERING THE APPROACHING UPSTREAM
TROUGH...MARGINAL AMOUNTS OF INSTABILITY...AND SUFFICIENT SHEAR IN
PLACE.
THE SECONDARY ISSUE TODAY WILL BE HEAVY RAINFALL. PWATS ARE STILL
WELL ABOVE NORMAL FOR MID-SEPT. THE LATEST GEFS SUGGEST PWATS ARE
1 TO ALMOST 3 STANDARD DEVIATIONS ABOVE NORMAL. THE ACTUAL PWATS
ARE FORECAST TO BE IN THE 1.33-1.80" RANGE WITH SOME POCKETS CLOSE
TO 2.00" IN THE MID HUDSON VALLEY AND NW CT. THE BEST H850 THETA-E
RIDGE SETS UP FROM THE CAPITAL REGION...SRN VT...AND THE ERN
CATSKILLS SOUTH AND EAST /330-335 K RANGE/. SOME TRAINING MAY
OCCUR WITH THE LINES OF CONVECTION. AN ISOLD FLASH FLOOD OR TWO
WILL BE POSSIBLE. THE COVERAGE IS NOT EXPECTED TO BE LARGE ENOUGH
FOR A FLASH FLOOD WATCH. OUR HYDRO DISCUSSION GETS INTO MORE
DETAILS ON THE RAINFALL BELOW.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
TONIGHT...SIGNIFICANT LOW AND MID LEVEL HEIGHT FALLS WILL OCCUR
AHEAD OF THE UPPER TROUGH...AS THE COLD FRONT MAKES STEADY
PROGRESS ACROSS THE REGION. THE COLD FRONT WILL GIVE A MAJOR BOOT
TO THE MUGGY AND STICKY WEATHER. THERE IS THE POTENTIAL A MID
LEVEL SHORT-WAVE MAY MIGRATE ALONG THE BOUNDARY KEEPING THE STEADY
RAINFALL GOING FROM THE CAPITAL REGION SOUTH AND EAST INTO EARLY
MORNING HOURS. THE NAM/GFS/ECMWF EVEN HINT AT A WEAK SFC WAVE
MOVING ALONG THE BOUNDARY. A WIDESPREAD 1 TO 2 INCHES OF RAINFALL
MAY OCCUR FROM THE AFTERNOON INTO TONIGHT. THE CONVECTION SHOULD
SHRIVEL UP SHORTLY BEFORE MIDNIGHT...AS THE INSTABILITY WANES
CONSIDERABLY. DECENT COLD ADVECTION WILL BE SWEEPING INTO THE NRN
ZONES BEFORE DAYBREAK. LOWS WILL RANGE FROM THE MID AND U40S OVER
THE SRN DACKS TO U50S AND L60S TO THE CAPITAL REGION...MID HUDSON
VALLEY...AND NW CT.
FRIDAY...QUITE A CONTRAST IN AIR MASSES...AND TEMPERATURES IS
EXPECTED. STRONG LOW LEVEL COLD ADVECTION WILL CONTINUE...AS THE
UPPER TROUGH MOVES OVER SRN QUEBEC AND THE NORTHEAST. THE CYCLONIC
VORTICITY ADVECTION ASSOCIATED WITH THE UPPER TROUGH WILL KICK OFF
SOME ISOLD-SCT INSTABILITY SHOWERS. THE COVERAGE WILL BE GREATEST
OVER THE HIGHER TERRAIN...AND NRN ZONES. IT WILL BE BRISK AND
CHILLY. MAX TEMPS WILL BE 20 TO 30 DEGREES COOLER THAN WEDNESDAY
IN THE FALL LIKE AIR MASS. MAX TEMPS WILL BE IN THE 50S OVER THE
SRN DACKS...SOME OF THE ERN CATSKILLS...AND SRN GREENS...AND 60S
TO A FEW L70S OVER THE REST OF THE FCST AREA.
FRIDAY NIGHT...THE INSTABILITY SHOWERS WILL CEASE TOWARDS
MIDNIGHT. THE CHILLY AIR MASS WILL BE OVER THE REGION...WITH A
DECENT SFC PRESSURE GRADIENT EXPECTED TO KEEP THE WINDS UP. H850
TEMPS LOWER TO +1 TO +4C. NOT EXPECTING FROST ON THIS NIGHT. LOWS
WILL BE QUITE COOL IN THE U30S TO M40S.
SATURDAY-SATURDAY NIGHT...THE UPPER LEVEL LOW CLOSES OFF AND MOVES
DOWN STREAM OVER SE QUEBEC AND NRN NEW ENGLAND. HIGH PRESSURE
BUILDS IN FROM THE MIDWEST AND GREAT LAKES REGION. THE WINDS WILL
BE LESS ON SATURDAY...BUT BELOW NORMAL TEMPS ARE EXPECTED WITH
MAINLY MID AND U60S IN THE VALLEYS...AND 50S TO L60S OVER THE
HIGHER TERRAIN. THE SFC HIGH WILL MOVE OVER NY AND PA SATURDAY
NIGHT WITH CLEAR/MOSTLY CLEAR SKIES AND LIGHT TO CALM WINDS. NEAR
IDEAL RADIATIONAL COOLING IS EXPECTED WITH TEMPS FALLING INTO THE
30S TO L40S. SOME AREAS OF FROST MAY MATERIALIZE OVER THE SRN
DACKS REGION. A BRIEF MENTION WILL BE PLACED IN THE HWO.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
DURING THE LONG TERM PERIOD EXPECT MAINLY DRY CONDITIONS WITH THE
EXCEPTION BEING A CHANCE OF SHOWERS MAINLY ACROSS THE NORTHERN AREAS
ON SUNDAY NIGHT AHEAD OF A COLD FRONT WHICH WILL BE DROPPING
SOUTHEAST FROM SOUTHERN CANADA AND PASS THROUGH OUR FA BY MONDAY
MORNING. TEMPERATURES ARE EXPECTED TO BE SEASONABLE ON SUNDAY AND
SUNDAY NIGHT AND THEN BELOW NORMAL IN THE WAKE OF THE COLD FRONT
MONDAY THROUGH WEDNESDAY.
ON SUNDAY EXPECT HIGHS IN THE MID 60S TO LOWER 70S WITH LOWS SUNDAY
NIGHT IN THE MID 40S TO LOWER 50S. FOR MONDAY EXPECT HIGHS TO RANGE
FROM THE LOW TO MID 50S NORTHWEST TO THE UPPER 60S SOUTHEAST WITH
LOWS MONDAY NIGHT IN THE MID 30S TO LOWER 40S. ON TUESDAY EXPECT
HIGHS IN THE MID 50S TO MID 60S WITH LOWS TUESDAY NIGHT IN THE MID
30S TO MID 40S AND HIGHS ON WEDNESDAY IN THE 60S TO AROUND 70.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
MORE SHRA/TSRA ARE EXPECTED TODAY AND THIS EVENING AHEAD OF AND
ALONG A COLD FRONTAL PASSAGE. CIGS AND VSBYS ARE LIKELY TO DIMINISH
TO MVFR/IFR WITH HEAVIER PCPN. MVFR FLYING CONDITIONS SHOULD PERSIST
THROUGH MOST OF THE NIGHT AS WELL AS STEADY SHOWERS MOVE ACROSS THE
REGION. IFR FOG WILL ALSO LIKELY DEVELOP AT KGFL AND KPSF LATE
TONIGHT BEFORE DRIER AIR MOVES IN WITH THE COLD FRONTAL PASSAGE. VFR
CONDITIONS WILL RETURN BY 13Z FRIDAY...WITH SOME LINGERING MVFR
CEILINGS ESPECIALLY AT KGFL AND KPSF.
LIGHT AND VARIABLE WINDS WILL BE SOUTH TO SOUTHWEST AT AROUND 10 KTS
THIS AFTERNOON AND THEN WEST TO NORTHWEST AROUND 5 KTS THIS EVENING
WITH THE PASSAGE OF THE COLD FRONT. WINDS WILL BE NORTHWESTERLY
FRIDAY AROUND 10 KNOTS.
OUTLOOK...
FRIDAY TO SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS AT THIS TIME WITH MORE WET WEATHER TODAY
INTO TONIGHT.
A COLD FRONT WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS TO
EASTERN NEW YORK AND WESTERN NEW ENGLAND TODAY INTO TONIGHT. SOME
VERY HEAVY RAINFALL WILL ACCOMPANY THE THUNDERSTORMS AND FRONTAL
PASSAGE. AN AUTUMNAL AIR MASS WILL BUILD INTO THE REGION ON
FRIDAY...AND THE COOLER AND DRIER WEATHER WILL CONTINUE INTO THE
WEEKEND.
THE RH VALUES WILL LOWER ONLY TO 55 TO 75 PERCENT IN THE MUGGY AIR
MASS THIS AFTERNOON...AND RECOVER TO 100 PERCENT TONIGHT. EXPECT MINIMUM
RH VALUES TO 50 TO 70 PERCENT FRIDAY AFTERNOON.
THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AT 5 TO 15 MPH
TODAY...AND THEN SHIFT TO THE WEST TO NORTHWEST AT 5 TO 10 MPH
TONIGHT. EXPECT BRISK NORTHWEST WINDS OF 10 TO 20 MPH ON
FRIDAY...WITH SOME GUSTS AROUND 30 MPH.
&&
.HYDROLOGY...
MORE WIDESPREAD CONVECTION IS EXPECTED TODAY INTO EARLY THIS EVENING
WITH ADDITIONAL TORRENTIAL DOWNPOURS...ASSOCIATED WITH A STRONG
COLD FRONT AND ANOTHER PREFRONTAL TROUGH DROPPING SOUTHEASTWARD
THROUGH OUR REGION LATE TODAY AND TONIGHT. DRIER AND MUCH COOLER
WEATHER IS EXPECTED TO END THE WEEK.
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 WITH
THE SHOWERS AND THUNDERSTORMS. THERE IS EVEN A THREAT OF ISOLATED FLASH
FLOODING WHERE THUNDERSTORMS MAY REPEATEDLY MOVE ACROSS THE SAME
AREAS. THE THUNDERSTORMS SHOULD DIMINISH EARLY THIS EVENING INTO THE
OVERNIGHT HOURS. THE FFG VALUES REMAIN HIGH TODAY. THE 1-HR ZONAL
FFG VALUES ARE IN THE 1.7-2.4 INCH RANGE...AND THE 3-HR ZONAL FFG
VALUES RANGE FROM 2.1-3.1 INCHES.
INTO TONIGHT...THE HYDRO SERVICE AREA MAY RECEIVE 1 TO 2 INCHES OF
RAIN WITH LOCALLY UP TO 3 INCHES. OVERALL...MAINLY MINOR FLOODING
OF POOR DRAINAGE...URBAN...AND LOW LYING AREAS IS EXPECTED WITH
ISOLATED FLASH FLOODING. SOME SIGNIFICANT WITHIN BANK RISES WILL
OCCUR ON MAIN STEM RIVERS...BUT NO FLOODING IS EXPECTED BASED ON
THE LATEST GUIDANCE FROM THE NERFC. FLOWS REMAIN AT NORMAL TO
BELOW NORMAL LEVELS HEADING INTO MID SEPTEMBER.
THE UPPER LOW MAY FOCUS SOME ISOLD-SCT SHOWERS FRIDAY INTO EARLY
FRIDAY EVENING...BUT RAINFALL WILL BE ON THE LIGHT SIDE. THE
WEEKEND IS EXPECTED TO BE DRY WITH HIGH PRESSURE IN CONTROL.
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/WASULA
NEAR TERM...FRUGIS/JPV/WASULA
SHORT TERM...WASULA
LONG TERM...11
AVIATION...IRL
FIRE WEATHER...WASULA
HYDROLOGY...JPV/WASULA
AREA FORECAST DISCUSSION
NWS ALBANY NY
100 PM EDT THU SEP 12 2013
.SYNOPSIS...
A COLD FRONT WILL BRING ANOTHER ROUND OF STRONG TO SEVERE
THUNDERSTORMS TO EASTERN NEW YORK AND WESTERN NEW ENGLAND THIS
AFTERNOON INTO TONIGHT. SOME VERY HEAVY RAINFALL WILL ACCOMPANY
THE THUNDERSTORMS AND FRONTAL PASSAGE. AN AUTUMN AIR MASS WILL
BUILD INTO THE REGION ON FRIDAY...AND THE COOLER AND DRIER WEATHER
WILL CONTINUE INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 100 PM EDT...SEVERE THUNDERSTORMS WATCH 523 HAS BEEN ISSUED
FOR ALL OF EAST CENTRAL NEW YORK AND WESTERN NEW ENGLAND UNTIL 8
PM THIS EVENING. THE MAIN THREAT WITH THUNDERSTORMS WILL BE
DAMAGING WIND GUSTS IN EXCESS OF 58 MPH.
SEVERAL BREAKS OF SUNSHINE ACROSS MUCH OF THE AREA LATE THIS
MORNING INTO EARLY AFTERNOON HAVE RESULTED IN A BUILD-UP OF
INSTABILITY. THE LATEST SPC RAP MESOANALYSIS PAGE SHOWS AROUND
1500-2500 J/KG OF SBCAPE ACROSS THE AREA AS OF NOON. THE SPECIAL
16Z ALB SOUNDING STILL REVEALED A WEAK CAP AROUND 900 MB...BUT
THIS IS EXPECTED TO MIX OUT IN THE NEXT COUPLE HOURS AND HAS
LIKELY ALREADY DONE SO ACROSS THE HIGHER TERRAIN WHERE SOME
CONVECTION HAS STARTED TO DEVELOP.
THE MOST CONCENTRATED CONVECTIVE ACTIVITY IS ACROSS CENTRAL NY
TIED TO THE NEXT PRE-FRONTAL TROUGH AND COLD FRONT MOVING EASTWARD
INTO OUR AREA DURING THE MID TO LATE AFTERNOON. EXPECTING A
CONTINUED TREND OF INCREASING COVERAGE OF CONVECTION WITH LIKELY
TO CATEGORICAL POPS. AN UPPER JET STEAK ASSOCIATED WITH THE
LONGWAVE TROUGH ADVANCING S/SE FROM S-CNTRL ONTARIO AND THE UPPER
MIDWEST WITH HELP ENHANCE THE RAINFALL...AND THE SVR THREAT TODAY
ACROSS ERN NY AND WRN NEW ENGLAND. THE ANTICYCLONIC ENTRANCE
REGION OF A 250 HPA 100-110+ KT JET STREAK WILL MOVE ACROSS NRN
AND ERN NY IN THE AFTERNOON.
SFC DEWPTS WILL STILL BE ABOVE NORMAL FOR MID SEPT IN THE 60S TO
EVEN SOME L70S. THE MID LEVEL LAPSE RATES WILL NOT BE AS STEEP
TODAY /GENERALLY LESS THAN 6.5 C/KM/...AS THE REMNANT ELEVATED
MIXED LAYER HAS SHIFTED DOWNSTREAM. THE 0-6 KM BULK SHEAR VALUES
INCREASE TO 25-40 KTS BY MID TO LATE AFTERNOON. MODEL SOUNDINGS
INDICATE SOME MULTICELLULAR CLUSTERS MAY FORM INTO A COUPLE OF
LINES. THE BEST CHC OF A SUPERCELL MAY BE ACROSS THE SRN EXTREME
WHEN THE 0-6 KM SHEAR INCREASE TO 40 KTS AND THE SBCAPE VALUES MAY
REACH 2000 J/KG. DAMAGING WINDS LOOK TO BE THE MAIN THREAT WITH
BOWING SEGMENTS...BUT WITH TALLER UPDRAFTS SOME LARGE HAIL IS
POSSIBLE. THE BEST 850-700 HPA THETA-E LAPSE RATES IMPACT
LOCATIONS FROM THE CAPITAL REGION SOUTH AND EAST TOWARDS
NIGHTFALL.
THE LATEST 3KM HRRR AND LOCAL HIRES WRF SHOWS A BROKEN LINE OF
SHOWERS/THUNDERSTORMS MOVING ACROSS THE REGION THIS AFTN INTO THIS
EVENING. THIS MAKES SENSE CONSIDERING THE APPROACHING UPSTREAM
TROUGH...MARGINAL AMOUNTS OF INSTABILITY...AND SUFFICIENT SHEAR IN
PLACE.
THE SECONDARY ISSUE TODAY WILL BE HEAVY RAINFALL. PWATS ARE STILL
WELL ABOVE NORMAL FOR MID-SEPT. THE LATEST GEFS SUGGEST PWATS ARE
1 TO ALMOST 3 STANDARD DEVIATIONS ABOVE NORMAL. THE ACTUAL PWATS
ARE FORECAST TO BE IN THE 1.33-1.80" RANGE WITH SOME POCKETS CLOSE
TO 2.00" IN THE MID HUDSON VALLEY AND NW CT. THE BEST H850 THETA-E
RIDGE SETS UP FROM THE CAPITAL REGION...SRN VT...AND THE ERN
CATSKILLS SOUTH AND EAST /330-335 K RANGE/. SOME TRAINING MAY
OCCUR WITH THE LINES OF CONVECTION. AN ISOLD FLASH FLOOD OR TWO
WILL BE POSSIBLE. THE COVERAGE IS NOT EXPECTED TO BE LARGE ENOUGH
FOR A FLASH FLOOD WATCH. OUR HYDRO DISCUSSION GETS INTO MORE
DETAILS ON THE RAINFALL BELOW.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
TONIGHT...SIGNIFICANT LOW AND MID LEVEL HEIGHT FALLS WILL OCCUR
AHEAD OF THE UPPER TROUGH...AS THE COLD FRONT MAKES STEADY
PROGRESS ACROSS THE REGION. THE COLD FRONT WILL GIVE A MAJOR BOOT
TO THE MUGGY AND STICKY WEATHER. THERE IS THE POTENTIAL A MID
LEVEL SHORT-WAVE MAY MIGRATE ALONG THE BOUNDARY KEEPING THE STEADY
RAINFALL GOING FROM THE CAPITAL REGION SOUTH AND EAST INTO EARLY
MORNING HOURS. THE NAM/GFS/ECMWF EVEN HINT AT A WEAK SFC WAVE
MOVING ALONG THE BOUNDARY. A WIDESPREAD 1 TO 2 INCHES OF RAINFALL
MAY OCCUR FROM THE AFTERNOON INTO TONIGHT. THE CONVECTION SHOULD
SHRIVEL UP SHORTLY BEFORE MIDNIGHT...AS THE INSTABILITY WANES
CONSIDERABLY. DECENT COLD ADVECTION WILL BE SWEEPING INTO THE NRN
ZONES BEFORE DAYBREAK. LOWS WILL RANGE FROM THE MID AND U40S OVER
THE SRN DACKS TO U50S AND L60S TO THE CAPITAL REGION...MID HUDSON
VALLEY...AND NW CT.
FRIDAY...QUITE A CONTRAST IN AIR MASSES...AND TEMPERATURES IS
EXPECTED. STRONG LOW LEVEL COLD ADVECTION WILL CONTINUE...AS THE
UPPER TROUGH MOVES OVER SRN QUEBEC AND THE NORTHEAST. THE CYCLONIC
VORTICITY ADVECTION ASSOCIATED WITH THE UPPER TROUGH WILL KICK OFF
SOME ISOLD-SCT INSTABILITY SHOWERS. THE COVERAGE WILL BE GREATEST
OVER THE HIGHER TERRAIN...AND NRN ZONES. IT WILL BE BRISK AND
CHILLY. MAX TEMPS WILL BE 20 TO 30 DEGREES COOLER THAN WEDNESDAY
IN THE FALL LIKE AIR MASS. MAX TEMPS WILL BE IN THE 50S OVER THE
SRN DACKS...SOME OF THE ERN CATSKILLS...AND SRN GREENS...AND 60S
TO A FEW L70S OVER THE REST OF THE FCST AREA.
FRIDAY NIGHT...THE INSTABILITY SHOWERS WILL CEASE TOWARDS
MIDNIGHT. THE CHILLY AIR MASS WILL BE OVER THE REGION...WITH A
DECENT SFC PRESSURE GRADIENT EXPECTED TO KEEP THE WINDS UP. H850
TEMPS LOWER TO +1 TO +4C. NOT EXPECTING FROST ON THIS NIGHT. LOWS
WILL BE QUITE COOL IN THE U30S TO M40S.
SATURDAY-SATURDAY NIGHT...THE UPPER LEVEL LOW CLOSES OFF AND MOVES
DOWN STREAM OVER SE QUEBEC AND NRN NEW ENGLAND. HIGH PRESSURE
BUILDS IN FROM THE MIDWEST AND GREAT LAKES REGION. THE WINDS WILL
BE LESS ON SATURDAY...BUT BELOW NORMAL TEMPS ARE EXPECTED WITH
MAINLY MID AND U60S IN THE VALLEYS...AND 50S TO L60S OVER THE
HIGHER TERRAIN. THE SFC HIGH WILL MOVE OVER NY AND PA SATURDAY
NIGHT WITH CLEAR/MOSTLY CLEAR SKIES AND LIGHT TO CALM WINDS. NEAR
IDEAL RADIATIONAL COOLING IS EXPECTED WITH TEMPS FALLING INTO THE
30S TO L40S. SOME AREAS OF FROST MAY MATERIALIZE OVER THE SRN
DACKS REGION. A BRIEF MENTION WILL BE PLACED IN THE HWO.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
DURING THE LONG TERM PERIOD EXPECT MAINLY DRY CONDITIONS WITH THE
EXCEPTION BEING A CHANCE OF SHOWERS MAINLY ACROSS THE NORTHERN AREAS
ON SUNDAY NIGHT AHEAD OF A COLD FRONT WHICH WILL BE DROPPING
SOUTHEAST FROM SOUTHERN CANADA AND PASS THROUGH OUR FA BY MONDAY
MORNING. TEMPERATURES ARE EXPECTED TO BE SEASONABLE ON SUNDAY AND
SUNDAY NIGHT AND THEN BELOW NORMAL IN THE WAKE OF THE COLD FRONT
MONDAY THROUGH WEDNESDAY.
ON SUNDAY EXPECT HIGHS IN THE MID 60S TO LOWER 70S WITH LOWS SUNDAY
NIGHT IN THE MID 40S TO LOWER 50S. FOR MONDAY EXPECT HIGHS TO RANGE
FROM THE LOW TO MID 50S NORTHWEST TO THE UPPER 60S SOUTHEAST WITH
LOWS MONDAY NIGHT IN THE MID 30S TO LOWER 40S. ON TUESDAY EXPECT
HIGHS IN THE MID 50S TO MID 60S WITH LOWS TUESDAY NIGHT IN THE MID
30S TO MID 40S AND HIGHS ON WEDNESDAY IN THE 60S TO AROUND 70.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
MORE SHRA/TSRA ARE EXPECTED TODAY AND THIS EVENING AHEAD OF AND
ALONG A COLD FRONTAL PASSAGE. THE BEST CHANCE WILL BE FROM AROUND LATE
MORNING OR EARLY AFTERNOON INTO THE EVENING HOURS. CIGS AND VSBYS
ARE LIKELY TO DIMINISH TO MVFR/IFR WITH HEAVIER PCPN. LATER TONIGHT
THE PCPN WILL TAPER OFF HOWEVER CIGS AND VSBYS WILL DROP TO IFR/LIFR
AT MOST SITES.
LIGHT AND VARIABLE WINDS WILL BECOME SOUTH TO SOUTHWEST AT 5 TO 10
KTS TODAY AND THEN WEST TO NORTHWEST AROUND 5 KTS THIS EVENING WITH
THE PASSAGE OF THE COLD FRONT.
OUTLOOK...
FRIDAY TO SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS AT THIS TIME WITH MORE WET WEATHER TODAY
INTO TONIGHT.
A COLD FRONT WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS TO
EASTERN NEW YORK AND WESTERN NEW ENGLAND TODAY INTO TONIGHT. SOME
VERY HEAVY RAINFALL WILL ACCOMPANY THE THUNDERSTORMS AND FRONTAL
PASSAGE. AN AUTUMNAL AIR MASS WILL BUILD INTO THE REGION ON
FRIDAY...AND THE COOLER AND DRIER WEATHER WILL CONTINUE INTO THE
WEEKEND.
THE RH VALUES WILL LOWER ONLY TO 55 TO 75 PERCENT IN THE MUGGY AIR
MASS THIS AFTERNOON...AND RECOVER TO 100 PERCENT TONIGHT. EXPECT MINIMUM
RH VALUES TO 50 TO 70 PERCENT FRIDAY AFTERNOON.
THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AT 5 TO 15 MPH
TODAY...AND THEN SHIFT TO THE WEST TO NORTHWEST AT 5 TO 10 MPH
TONIGHT. EXPECT BRISK NORTHWEST WINDS OF 10 TO 20 MPH ON
FRIDAY...WITH SOME GUSTS AROUND 30 MPH.
&&
.HYDROLOGY...
MORE WIDESPREAD CONVECTION IS EXPECTED TODAY INTO EARLY THIS EVENING
WITH ADDITIONAL TORRENTIAL DOWNPOURS...ASSOCIATED WITH A STRONG
COLD FRONT AND ANOTHER PREFRONTAL TROUGH DROPPING SOUTHEASTWARD
THROUGH OUR REGION LATE TODAY AND TONIGHT. DRIER AND MUCH COOLER
WEATHER IS EXPECTED TO END THE WEEK.
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 WITH
THE SHOWERS AND THUNDERSTORMS. THERE IS EVEN A THREAT OF ISOLATED FLASH
FLOODING WHERE THUNDERSTORMS MAY REPEATEDLY MOVE ACROSS THE SAME
AREAS. THE THUNDERSTORMS SHOULD DIMINISH EARLY THIS EVENING INTO THE
OVERNIGHT HOURS. THE FFG VALUES REMAIN HIGH TODAY. THE 1-HR ZONAL
FFG VALUES ARE IN THE 1.7-2.4 INCH RANGE...AND THE 3-HR ZONAL FFG
VALUES RANGE FROM 2.1-3.1 INCHES.
INTO TONIGHT...THE HYDRO SERVICE AREA MAY RECEIVE 1 TO 2 INCHES OF
RAIN WITH LOCALLY UP TO 3 INCHES. OVERALL...MAINLY MINOR FLOODING
OF POOR DRAINAGE...URBAN...AND LOW LYING AREAS IS EXPECTED WITH
ISOLATED FLASH FLOODING. SOME SIGNIFICANT WITHIN BANK RISES WILL
OCCUR ON MAIN STEM RIVERS...BUT NO FLOODING IS EXPECTED BASED ON
THE LATEST GUIDANCE FROM THE NERFC. FLOWS REMAIN AT NORMAL TO
BELOW NORMAL LEVELS HEADING INTO MID SEPTEMBER.
THE UPPER LOW MAY FOCUS SOME ISOLD-SCT SHOWERS FRIDAY INTO EARLY
FRIDAY EVENING...BUT RAINFALL WILL BE ON THE LIGHT SIDE. THE
WEEKEND IS EXPECTED TO BE DRY WITH HIGH PRESSURE IN CONTROL.
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/WASULA
NEAR TERM...FRUGIS/JPV/WASULA
SHORT TERM...WASULA
LONG TERM...11
AVIATION...11
FIRE WEATHER...WASULA
HYDROLOGY...JPV/WASULA
AREA FORECAST DISCUSSION
NWS DULUTH MN
324 PM CDT THU SEP 12 2013
.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.
&&
$$
SHORT TERM...GROCHOCINSKI
LONG TERM...LE
AVIATION...LE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
405 PM EDT THU SEP 12 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL PASS THROUGH THIS EVENING AND EARLY
TONIGHT...ENDING THE HOT AND HUMID WEATHER OF THE PAST SEVERAL
DAYS. ANOTHER TASTE OF FALL WILL ARRIVE IN THE WAKE OF THIS
FRONT. BELOW NORMAL TEMPERATURES ARE EXPECTED FROM FRIDAY INTO THE
UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
LONG-LIVED BOW ECHO INHERITED FROM THE WEST LATE THIS
MORNING/EARLY AFTN CONTINUES TO BLOW DOWN TREES AS IT GETS INTO
THE MID SUSQ/LOWER SUSQ WHERE CAPES ARE HIGHER THAN THE NORTHERN
THIRD/HALF OF THE AREA.
HRRR AND RUC ARE IN AGREEMENT IN INDICATING A SECONDARY BUT MUCH
MORE-BROKEN AND SHORTER/WEAKER LINE OF SHOWERS/STORM MOVING
THROUGH BETWEEN 23Z-02Z. THIS IS ALL IN LINE WITH THE GOING FCST.
DISSIPATION OF THE SHOWERS SHOULD OCCUR AFTER SUNSET. SOME SHOWERS
MAY LINGER ALONG THE FAR EAST AND FAR SRN TIER THRU MIDNIGHT...BUT
THESE SHOULD BE WELL BEHIND THE BEST MOISTURE AND HEATING.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH 6 PM FRIDAY/...
MOST IF NOT ALL THE SHOWERS SHOULD BE GONE BY MIDNIGHT...AND WIND
STAYS UP FOR MUCH OF THE NIGHT. BUT LOW CLOUDS AND SOME FOG IS
EXPECTED TONIGHT WITH HIGH MSTR AND ASCENT INTO THE MTNS.
DOWNSLOPE MAY HELP SOME CLEARING OCCUR IN THE SE...BUT WILL PLAY
IT MORE CLOUDY AT FIRST AND P/C LATER. DESPITE THE CLOUDS...TEMP
ADV IS STRONGLY NEG AND TEMPS SHOULD DROP INTO THE 40S IN THE N
AND 50S MOST ELSEWHERE.
THE 5H TROUGH AXIS STILL SLATED TO SWING THROUGH LATE TONIGHT AND
DURING THE DAY TIME ON FRI. 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.
&&
.LONG TERM /FRIDAY 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 HIEST 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 /20Z THURSDAY THROUGH TUESDAY/...
STORMS OVER THE EAST ARE MOVING QUICKLY...BUT WILL STILL HAVE
POTENTIAL TO MAKE 40+KT GUSTS IN MDT AND LNS IN VERY SHORT ORDER.
THIS LINE SHOULD CONTINUE EAST AND BE OUT OF THE AREA BY 22Z. BUT
AN ADDITIONAL AREA OF SCT SHRA AND POSS T WILL SLIDE THROUGH AS
THE COLD FRONT MOVES THROUGH LATE THIS EVENING AND EARLY TONIGHT.
COOLER AND DRIER AIR WILL BEGIN TO WORK IN BEHIND THE COLD FRONT
TONIGHT. HOWEVER...LINGERING LOW LEVEL MOISTURE FORCED TO ASCEND
THE ALLEGHENY MTNS WILL PROBABLY PRODUCE SOME IFR CIGS AT BFD AND
JST. 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...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...CERU/GARTNER
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
348 PM EDT THU SEP 12 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL PASS THROUGH THIS EVENING AND EARLY
TONIGHT...ENDING THE HOT AND HUMID WEATHER OF THE PAST SEVERAL
DAYS. ANOTHER TASTE OF FALL WILL ARRIVE IN THE WAKE OF THIS
FRONT. BELOW NORMAL TEMPERATURES ARE EXPECTED FROM FRIDAY INTO THE
UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 11 PM THIS EVENING/...
LONG-LIVED BOW ECHO INHERITED FROM THE WEST LATE THIS
MORNING/EARLY AFTN CONTINUES TO BLOW DOWN TREES AS IT GETS INTO
THE MID SUSQ/LOWER SUSQ WHERE CAPES ARE HIGHER THAN THE NORTHERN
THIRD/HALF OF THE AREA.
HRRR AND RUC ARE IN AGREEMENT IN INDICATING A SECONDARY BUT MUCH
MORE-BROKEN AND SHORTER/WEAKER LINE OF SHOWERS/STORM MOVING
THROUGH BETWEEN 23Z-02Z. THIS IS ALL IN LINE WITH THE GOING FCST.
DISSIPATION OF THE SHOWERS SHOULD OCCUR AFTER SUNSET. SOME SHOWERS
MAY LINGER ALONG THE FAR EAST AND FAR SRN TIER THRU MIDNIGHT...BUT
THESE SHOULD BE WELL BEHIND THE BEST MOISTURE AND HEATING.
&&
.SHORT TERM /11 PM THIS EVENING THROUGH 6 PM FRIDAY/...
MOST IF NOT ALL THE SHOWERS SHOULD BE GONE BY MIDNIGHT...AND WIND
STAYS UP FOR MUCH OF THE NIGHT. BUT LOW CLOUDS AND SOME FOG IS
EXPECTED TONIGHT WITH HIGH MSTR AND ASCENT INTO THE MTNS.
DOWNSLOPE MAY HELP SOME CLEARING OCCUR IN THE SE...BUT WILL PLAY
IT MORE CLOUDY AT FIRST AND P/C LATER. DESPITE THE CLOUDS...TEMP
ADV IS STRONGLY NEG AND TEMPS SHOULD DROP INTO THE 40S IN THE N
AND 50S MOST ELSEWHERE.
THE 5H TROUGH AXIS STILL SLATED TO SWING THROUGH LATE TONIGHT AND
DURING THE DAY TIME ON FRI. THE INSTAILITY 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.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
THE MAIN STORY OF THE EXTENDED IS A RETURN TO AUTUMN AS TEMPERATURES
DROP BACK TO WELL BELOW NORMAL LEVELS. EXPECTING A MUCH COOLER
WEEKEND WITH TEMPERATURES FROM THE MID 60S ON SATURDAY...TO LOW
70S ON SUNDAY.
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 /20Z THURSDAY THROUGH TUESDAY/...
STORMS OVER THE EAST ARE MOVING QUICKLY...BUT WILL STILL HAVE
POTENTIAL TO MAKE 40+KT GUSTS IN MDT AND LNS IN VERY SHORT ORDER.
THIS LINE SHOULD CONTINUE EAST AND BE OUT OF THE AREA BY 22Z. BUT
AN ADDITIONAL AREA OF SCT SHRA AND POSS T WILL SLIDE THROUGH AS
THE COLD FRONT MOVES THROUGH LATE THIS EVENING AND EARLY TONIGHT.
COOLER AND DRIER AIR WILL BEGIN TO WORK IN BEHIND THE COLD FRONT
TONIGHT. HOWEVER...LINGERING LOW LEVEL MOISTURE FORCED TO ASCEND
THE ALLEGHENY MTNS WILL PROBABLY PRODUCE SOME IFR CIGS AT BFD AND
JST. 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...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...CERU
AVIATION...DANGELO