Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/26/15
AREA FORECAST DISCUSSION
NWS RENO NV
135 PM PST THU DEC 24 2015
.SYNOPSIS...
AFTER HEAVY SNOW SHOWERS MOVE OUT TONIGHT, A FEW LIGHT SNOW
SHOWERS REMAIN POSSIBLE ON FRIDAY. FRESH SNOWCOVER WILL LEAD TO
WIDESPREAD COLD TEMPERATURES CHRISTMAS DAY THROUGH THE WEEKEND. A
WEAKENING STORM WILL BRING LIGHT SNOW SHOWERS TO THE REGION
MONDAY, WITH POTENTIAL FOR A SLIDER WEDNESDAY OR THURSDAY
PROVIDING A CHANCE FOR SNOW IN NORTHERN AND WESTERN NEVADA.
&&
.SHORT TERM...
ONGOING WINTER STORM BEHAVING MORE OR LESS AS EXPECTED WITH
SIGNIFICANT TRAVEL IMPACTS CONTINUING INTO THE EVENING HOURS.
WE`VE SEEN BIG DELAYS AND TEMPORARY ROAD CLOSURES OVER THE SIERRA,
AND DELAYS/DIVERSION INTO RNO AIRPORT DUE TO HEAVY SNOW AND LOW
VISIBILITY. OVERALL THE BULK OF THE HEAVY SNOW SHOWERS WILL SETTLE
SOUTHWARD THROUGH THE AFTERNOON AND EVENING. SEE OUR SOCIAL MEDIA
AND LSR FOR SPECIFIC SNOW REPORTS. MAIN FORECAST ISSUES ARE --
* WITH NUMEROUS REPORTS OF 20:1 SNOW RATIOS (UNSURPRISING) AND
BURSTS OF HEAVY PRECIP SEEN IN THE HRRR, I`VE INCREASED SNOW
TOTAL FORECASTS FOR THE SIERRA FRONT, TAHOE, AND MONO CO
REGIONS. SNOW AMOUNTS WILL VARY A LOT DUE TO SHOWERY/BANDED
NATURE OF THE PRECIP GIVEN UNSTABLE AIRMASS. LAKE EFFECT OFF OF
TAHOE HAS OCCURRED PERIODICALLY TODAY AND THE RISK CONTINUES
INTO EARLY EVENING WITH WESTERLY FLOW ALOFT FOR CARSON
CITY/CARSON VALLEY. OVERALL MESSAGE IS THE SAME THOUGH - ROUGH
TRAVEL ON ROADS AREAWIDE THROUGH THIS EVENING, WITH AREAS OF
BLOWING SNOW AND ZERO VISIBILITY IN THE MOUNTAINS. REFREEZE OF
MELTED SNOW ON ROADS WILL BE AN ISSUE TOO TONIGHT.
* GUIDANCE IS SHOWING A SECONDARY WAVE ALOFT DROPPING IN LATE
TONIGHT AND FRIDAY, WHICH COULD SPARK ADDITIONAL SNOW SHOWER
DEVELOPMENT. LOCATION OF THIS ACTIVITY HIGHLY VARIABLE IN THE
SIMULATIONS BUT BEST BET IS THE SIERRA WITH A SLIGHT UPSLOPE
COMPONENT, BUT AIRMASS REMAINS COLD AND UNSTABLE AREA WIDE SO WE
CAN`T RULE OUT SHSN ANYWHERE FRIDAY. A QUICK 1-3" ACCUM POSSIBLE
DEPENDING ON HOW ROBUST THE SHOWERS BECOME.
CS
.LONG TERM...SATURDAY TO WEDNESDAY...
COLD PROGRESSIVE FLOW WILL CONTINUE INTO THE WEST COAST WHICH MAY
ALLOW A COUPLE FAST MOVING SYSTEMS TO IMPACT THE AREA INTO THE
MIDDLE OF NEXT WEEK.
AS THE CURRENT TROUGH OVER THE REGION EXITS ON FRIDAY NIGHT,
NORTHEAST TO EAST WINDS WILL DEVELOP IN THE SIERRA AND TAHOE BASIN.
HAVE ISSUED A LAKE WIND ADVISORY FOR TAHOE FOR FRIDAY NIGHT AND
SATURDAY MORNING WITH WAVES UP TO 4 FEET AND GUSTS NEAR 35 MPH.
FOR THE WEEKEND, CONDITIONS WILL BE DRY AND COLD. OVERNIGHT LOWS
WILL BE BELOW ZERO IN MOST SIERRA VALLEYS AND IN THE -5 TO 15 RANGE
ACROSS WESTERN NEVADA AND NORTHEAST CALIFORNIA WITH THE FRESH SNOW
COVER. VALLEY INVERSIONS WILL LIKELY DEVELOP AND KEEP AFTERNOON
HIGHS IN THE 20S TO LOW 30S.
NEXT SYSTEM SHOULD ARRIVE IN TIME FOR THE MONDAY MORNING COMMUTE.
LIQUID AMOUNTS IN THE MODELS ARE LESS THAN 0.10 INCH, WITH SNOW
LEVELS NEAR AND BELOW 4000 FEET. SNOW AMOUNTS SHOULD BE LESS THAN AN
INCH FOR MOST LOCATIONS, THOUGH EVEN A HALF INCH OF SNOW COULD CAUSE
TRAVEL ISSUES FOR THE MONDAY MORNING COMMUTE.
MODELS SHOW A SECOND SLIDER SYSTEM FOR MID WEEK, BUT TRACK WILL
DEPEND ON WHERE THE EASTERN PACIFIC RIDGE SETS UP. FOR NOW THE TRACK
OF THIS SYSTEM VARIES BETWEEN WESTERN NEVADA AND UTAH. IF THE TRACK
IS OVER WESTERN NEVADA, ANOTHER ROUND OF SNOW ON VALLEY FLOORS IS
LIKELY. SOMETHING TO KEEP AN EYE ON OVER THE NEXT FEW DAYS. BRONG
&&
.AVIATION...
SNOW SHOWERS WILL BRING QUICK VARIATIONS IN FLIGHT CONDITIONS FOR
AREA AIRPORTS, RANGING FROM VFR TO LIFR IN A MATTER OF MINUTES.
BASED ON THE LATEST HRRR GUIDANCE, THE MAIN RISK AREA FOR THIS
WILL SETTLE SOUTHWARD THROUGH THE AFTERNOON AND EVENING. FOR
RNO/CXP 22Z-01Z WILL MARK THIS TRANSITION FROM HEAVIER SHOWERS TO
LIGHTER ONES, TVL/TRK SOMETIME BETWEEN 01-03Z, AND MMH 04-06Z.
ADDITIONAL SNOW ACCUMULATIONS ARE LIKELY WITH RATES IN SHOWERS
1"/HOUR FOR RNO/CXP, AND POSSIBLY 2-3"/HR FOR TVL/TRK/MMH.
AFTER 6Z/FRIDAY MAIN ISSUES WILL BE RESIDUAL CLOUDS AND LIGHT
SNOW SHOWERS NEAR THE MOUNTAINS, LEADING TO TERRAIN OBSCURATION.
SECONDARY WAVE ALOFT MAY BRING SOME MVFR SNOW SHOWERS TO THE
REGION BETWEEN 9Z/FRI-21Z/FRI. PREDICTABILITY OF THESE IS LOW DUE
TO VARYING TRACKS IN THE SIMULATIONS, SO AM ADDRESSING WITH VCSH
IN THE TAFS. MOST LIKELY AIRPORTS TO SEE THESE ARE TVL/TRK. CS
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ005.
LAKE WIND ADVISORY FROM 10 PM FRIDAY TO 10 AM PST SATURDAY FOR
LAKE TAHOE IN NVZ002.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING NVZ002.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ001-004.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ003.
CA...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ071.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING CAZ070.
WINTER STORM WARNING UNTIL 4 AM PST FRIDAY CAZ073.
LAKE WIND ADVISORY FROM 10 PM FRIDAY TO 10 AM PST SATURDAY FOR
LAKE TAHOE IN CAZ072.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
1014 AM PST THU DEC 24 2015
.UPDATE...
SO WE HAVE A RESPECTABLE WINTER STORM ON OUR HANDS TODAY! THIS AT
THE SAME TIME NEW YORK CITY IS 70 DEGREES ON CHRISTMAS EVE!
WIDESPREAD HEAVY SNOW SHOWERS ACROSS THE REGION WITH REPORTS OF
1-2"/HOUR RATES IN THE VALLEYS INCLUDING AROUND RENO AND CARSON
CITY, WITH 3+"/HOUR IN THE SIERRA. VERY HIGH RATIO SNOWS, WITH A
COUPLE OBSERVATIONS OF AT LEAST 20:1. WE ARE SENDING OUT REPORTS
VIA LSR AS WE GET THEM, ALSO MONITOR OUR SOCIAL MEDIA FOR FREQUENT
UPDATES AND SNOW REPORTS. SUFFICE IT TO SAY ROADS ARE A MESS
ACROSS THE SIERRA, NE CALIFORNIA, AND FAR WESTERN NEVADA. WE ARE
ALSO SEEING NEAR BLIZZARD CONDITIONS OVER THE PASSES WITH BLOWING
SNOW. GOES WITHOUT SAYING THAT TRAVEL IS NOT RECOMMENDED.
FOR NEXT 12 HOURS, THE BIG PICTURE REMAINS THE SAME WITH HEAVY
SNOW SHOWERS CONTINUING INTO EARLY AFTERNOON THEN GRADUALLY
WORKING SOUTH AND EAST INTO THE BALANCE OF THE AFTERNOON AND
EVENING. THIS IS SHOWN WELL IN THE LATEST HRRR GUIDANCE, WITH SOME
IMPRESSIVE QPF ENHANCEMENTS AT TIMES. AIRMASS IS QUITE UNSTABLE
LEADING TO HIGH SNOWFALL RATES AND NUMEROUS BANDS OF SNOW.
THEREFORE AMOUNTS WILL VARY OVER THE REGION. ONE SUCH BAND IS NOW
TRAINING JUST SOUTH OF I-80 INCLUDING THE RENO/SPARKS AREA -
SHOULD THIS CONTINUE WE COULD EASILY SEE 5" OR MORE IN THESE
AREAS. WHILE LOCATIONS 5-10 MILES TO THE NORTH WILL SEE LESS.
NO CHANGES PLANNED TO THE ADVISORIES/WARNINGS AS THE MESSAGE IS
ALREADY OUT THERE. WILL SEND UPDATE TO GRIDDED FORECAST SHORTLY.
CS
&&
.PREVIOUS DISCUSSION... /ISSUED 329 AM PST THU DEC 24 2015/
SYNOPSIS...
A COLD FAST MOVING STORM WILL BRING PERIODS OF HEAVY SNOW AND SNOW
SHOWERS TO THE SIERRA AND WESTERN NEVADA TODAY AND TONIGHT. SNOW
COVERED ROADS AND BLOWING SNOW ARE LIKELY FOR MUCH OF THE REGION.
COLD CONDITIONS ARE ON TAP FOR CHRISTMAS DAY INTO THE WEEKEND.
WHILE MOST OF NEXT WEEK APPEARS DRY WITH A SLOW WARMING TREND, ONE
OR TWO WEAK STORMS MAY IMPACT THE AREA WITH LIGHT PRECIPITATION.
SHORT TERM...
RAISED WINDS SLIGHTLY FOR THE HIGHWAY 395 CORRIDOR NEAR AND SOUTH
OF HIGHWAY 203 (MAMMOTH LAKES) THIS AFTERNOON, OTHERWISE MINIMAL
CHANGE TO THE SHORT TERM FORECAST. ALL WARNINGS AND ADVISORIES FOR
TODAY STILL LOOK ON TRACK.
LOOKING AT THE INFRARED AND WATER VAPOR SATELLITES, THE UPPER JET
CORE HAS DROPPED INTO CENTRAL CALIFORNIA/SOUTHERN NEVADA (DRY SLOT
IN WATER VAPOR) WITH COLDER CLOUD TOPS MOVING INTO NORTHERN
CALIFORNIA AND NORTHWEST NEVADA AHEAD OF THE UPPER LOW CORE OFF
THE OREGON COAST. THERE WAS CLOUD-TO-GROUND LIGHTNING WITH THE
MAIN BAND AS IT MOVED ASHORE NEAR ARCATA, CA A FEW HOURS AGO,
INDICATIVE OF THE INSTABILITY AND CONVECTIVE NATURE OF THE COLD
LOW (100-250 J/KG OF CAPE NEAR COAST PER 10Z SPC MESOANALYSIS).
WIDESPREAD SHOWERS OVER NORTHERN CALIFORNIA WILL CONTINUE TO DRIVE
SOUTH AND EAST THIS MORNING, WITH THE 09Z HRRR BRINGING SNOW AND
SNOW SHOWERS TO ALL OF THE NORTHERN SIERRA AND WESTERN NEVADA (TO
ABOUT HIGHWAY 50) BETWEEN ~5-9 AM. SHOWERS WILL SPREAD SOUTH OVER
EASTERN MONO AND MINERAL COUNTIES THIS AFTERNOON. THERE COULD BE
A WIDE RANGE OF SNOWFALL TOTALS THROUGH THIS AFTERNOON, ESPECIALLY
EAST OF THE SIERRA, AS LOCALIZED HEAVY SNOW BANDS DEPOSIT IN SOME
AREAS AND NOT OTHERS. LAKE EFFECT SNOW IS ALSO LIKELY TO BRING
SOME LOCALLY HIGHER AMOUNTS DOWNWIND OF LAKE TAHOE AND EVENTUALLY
(~LATE AFTERNOON) PYRAMID LAKE TODAY. IN FACT, THERE ARE SIGNS
THAT LAKE TAHOE IS ALREADY FIRING UP SOME LAKE EFFECT SNOW NEAR
AND NORTH OF HIGHWAY 50 IN FAR WESTERN NEVADA.
BRIEFLY TURNING TO WINDS, THEY SHOULD GUST MAINLY INTO THE 25-35 MPH
RANGE TODAY AHEAD OF THE PRECIPITATION BAND. HOWEVER, LOCAL GUSTS
OF 40-50 MPH ARE POSSIBLE IN WIND PRONE AREAS ALONG HIGHWAY 395
SOUTH OF RENO THROUGH MONO COUNTY AND OUT INTO FAR WESTERN MINERAL
AND SOUTHERN LYON COUNTIES.
THE MAIN AREA OF SNOW SHOWERS DROPS SOUTH OF I-80 THIS EVENING,
ALTHOUGH RESIDUAL SHOWERS ARE POSSIBLE THROUGH TONIGHT ESPECIALLY
DOWNWIND OF PYRAMID LAKE AND PERHAPS LAKE TAHOE (THIS EVENING
ESPECIALLY). THE NAM HAS FINALLY BACKED OFF ON A SECOND SHOT OF
SNOW FOR CHURCHILL AND PERSHING COUNTIES TONIGHT, MORE IN LINE
WITH OTHER MODELS. ANY SNOW ACCUMULATIONS TONIGHT SHOULD REMAIN
LIGHT FOR WESTERN NEVADA, EXCEPT DOWNWIND OF PYRAMID LAKE WHERE
SEVERAL INCHES CANNOT BE RULED OUT. FOR THE SIERRA, WESTERN MONO
AND ALPINE COUNTIES COULD SEE ANOTHER 4-8 INCHES TONIGHT AS
UNSTABLE, MOIST UPSLOPE FLOW PUSHES SNOW ACROSS THE CREST INTO THE
EASTERN SIERRA.
CHRISTMAS DAY THROUGH THE WEEKEND WILL REMAIN COLD UNDER NORTH-
EAST FLOW AS THE TROUGH SLOWLY EXITS. LOWS WILL WE QUITE COLD BY
FRIDAY NIGHT AS CLEARING WORKS INTO THE REGION, WITH BELOW ZERO
READINGS LIKELY FOR THE COLDER, SNOW-COVERED VALLEYS OF WESTERN
NEVADA (OUTSIDE MAIN URBAN AREAS) AND CERTAINLY FOR THE SIERRA
VALLEYS. VALLEY INVERSIONS SHOULD BECOME QUITE STRONG BY SATURDAY
AND SATURDAY NIGHT AS A RIDGE BUILDS OVERHEAD. SNYDER
LONG TERM...SUNDAY THROUGH WEDNESDAY...
FEW CHANGES MADE TO THE LONG TERM AS THE MODELS AND ENSEMBLES DEPICT
A MEAN RIDGE DEVELOPING ALONG THE COAST. THEY STILL DEPICT WEAK
WAVES MOVING THROUGH THE RIDGE OR DROPPING DOWN THE EAST SIDE INTO
THE MIDDLE OF NEXT WEEK. THE MONDAY SYSTEM LOOKS TO BE THE
STRONGEST, BUT IT REALLY IS QUITE WEAK OVERALL. THE MAIN DIFFERENCES
IN THE MODELS ARE THAT THE GFS IS A BIT FURTHER EAST WITH THE RIDGE
AND HAS THE SYSTEMS THAT DROP DOWN FROM THE NORTH INTO EASTERN
NEVADA. THE EC HAS THEM DROPPING INTO WESTERN NEVADA LIKE INSIDE
SLIDERS. HAVE USED A BLEND OF ALL GUIDANCE AS TRACKING THESE
INDIVIDUAL WAVES IS FUTILE AT BEST 5-7 DAYS OUT.
SUNDAY WILL STILL BE COLD IN THE VALLEYS UNDER A STRONG INVERSION
WHILE MTNS WARM. WITH THE MONDAY SYSTEM, THE BEST CHANCE OF SNOW
SHOWERS LOOKS TO BE IN THE SIERRA FROM TAHOE NORTH AND ALONG THE
OREGON BORDER. IT WILL ALSO HELP TO IMPROVE MIXING A BIT WITH COOLER
TEMPS ALOFT. TUESDAY AND WEDNESDAY, TWO MORE WEAK SYSTEMS WILL DROP
IN FROM THE NORTH. FOR NOW, HAVE KEPT IN A SLIGHT CHANCE OF SHOWERS
FOR TUESDAY ACROSS THE NORTH AND LEFT WEDNESDAY DRY. HAVE GONE WITH
A SLOW WARMING TREND, ESPECIALLY IN THE MOUNTAINS DUE TO BETTER
MIXING. HOWEVER, IF THERE IS ENOUGH SNOW COVER LEFT BY WEDNESDAY IN
WRN NV VALLEYS, THEY COULD BE TRAPPED UNDER A STRONG INVERSION
AGAIN. WALLMANN
AVIATION...
MAIN CONCERN IS THE SHSN MOVING THROUGH THE SIERRA AND WESTERN
NEVADA TODAY. IFR CONDS THRU 21-00Z FOR KTRK/KTVL THEN SOME MVFR
CONDS THRU 06Z BEFORE IMPROVING. KRNO/KCXP 2-3 HR PERIOD OF IFR
CONDS BETWEEN 15-20Z WITH OCNL MVFR 20-01Z IN -SHSN. KMMH IFR
CONDS 18-01Z THEN GRADUALLY IMPROVING AS WELL. RUNWAY ACCUMS STILL
LOOK TO BE AROUND 6" KTRK/KTVL 2-4" KRNO/KCXP AND 4-6" FOR KMMH.
EXPECT ALL TERMINALS VFR AFTER 09Z FRI.
OTHER CONCERN IS WINDS WITH RIDGE GUSTS 60 KTS ATTM. SOME LLWS THIS
MORNING THRU 15-17Z BEFORE SNOW COMMENCES AND WINDS CLOSER TO
SURFACE ABATE. OTHERWISE SFC WND GUSTS TO 25 KTS MOST LIKELY AT ALL
TERMINALS FROM S-SW THRU 03Z. EXCEPTION WILL BE KMMH WHERE WNW FLOW
ALOFT ALIGNS BETTER AND PEAK GUSTS TO 40-45 KTS POSSIBLE 15-03Z.
WALLMANN
REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING NVZ002.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ005.
WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 10 PM PST THIS
EVENING NVZ001-003-004.
CA...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ071-072.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING CAZ070.
WINTER STORM WARNING FROM 10 AM THIS MORNING TO 4 AM PST FRIDAY
CAZ073.
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ005.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING NVZ002.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ001-004.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ003.
CA...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ071.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING CAZ070.
WINTER STORM WARNING UNTIL 4 AM PST FRIDAY CAZ073.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS RENO NV
329 AM PST THU DEC 24 2015
.SYNOPSIS...
A COLD FAST MOVING STORM WILL BRING PERIODS OF HEAVY SNOW AND SNOW
SHOWERS TO THE SIERRA AND WESTERN NEVADA TODAY AND TONIGHT. SNOW
COVERED ROADS AND BLOWING SNOW ARE LIKELY FOR MUCH OF THE REGION.
COLD CONDITIONS ARE ON TAP FOR CHRISTMAS DAY INTO THE WEEKEND.
WHILE MOST OF NEXT WEEK APPEARS DRY WITH A SLOW WARMING TREND, ONE
OR TWO WEAK STORMS MAY IMPACT THE AREA WITH LIGHT PRECIPITATION.
&&
.SHORT TERM...
RAISED WINDS SLIGHTLY FOR THE HIGHWAY 395 CORRIDOR NEAR AND SOUTH
OF HIGHWAY 203 (MAMMOTH LAKES) THIS AFTERNOON, OTHERWISE MINIMAL
CHANGE TO THE SHORT TERM FORECAST. ALL WARNINGS AND ADVISORIES FOR
TODAY STILL LOOK ON TRACK.
LOOKING AT THE INFRARED AND WATER VAPOR SATELLITES, THE UPPER JET
CORE HAS DROPPED INTO CENTRAL CALIFORNIA/SOUTHERN NEVADA (DRY SLOT
IN WATER VAPOR) WITH COLDER CLOUD TOPS MOVING INTO NORTHERN
CALIFORNIA AND NORTHWEST NEVADA AHEAD OF THE UPPER LOW CORE OFF
THE OREGON COAST. THERE WAS CLOUD-TO-GROUND LIGHTNING WITH THE
MAIN BAND AS IT MOVED ASHORE NEAR ARCATA, CA A FEW HOURS AGO,
INDICATIVE OF THE INSTABILITY AND CONVECTIVE NATURE OF THE COLD
LOW (100-250 J/KG OF CAPE NEAR COAST PER 10Z SPC MESOANALYSIS).
WIDESPREAD SHOWERS OVER NORTHERN CALIFORNIA WILL CONTINUE TO DRIVE
SOUTH AND EAST THIS MORNING, WITH THE 09Z HRRR BRINGING SNOW AND
SNOW SHOWERS TO ALL OF THE NORTHERN SIERRA AND WESTERN NEVADA (TO
ABOUT HIGHWAY 50) BETWEEN ~5-9 AM. SHOWERS WILL SPREAD SOUTH OVER
EASTERN MONO AND MINERAL COUNTIES THIS AFTERNOON. THERE COULD BE
A WIDE RANGE OF SNOWFALL TOTALS THROUGH THIS AFTERNOON, ESPECIALLY
EAST OF THE SIERRA, AS LOCALIZED HEAVY SNOW BANDS DEPOSIT IN SOME
AREAS AND NOT OTHERS. LAKE EFFECT SNOW IS ALSO LIKELY TO BRING
SOME LOCALLY HIGHER AMOUNTS DOWNWIND OF LAKE TAHOE AND EVENTUALLY
(~LATE AFTERNOON) PYRAMID LAKE TODAY. IN FACT, THERE ARE SIGNS
THAT LAKE TAHOE IS ALREADY FIRING UP SOME LAKE EFFECT SNOW NEAR
AND NORTH OF HIGHWAY 50 IN FAR WESTERN NEVADA.
BRIEFLY TURNING TO WINDS, THEY SHOULD GUST MAINLY INTO THE 25-35 MPH
RANGE TODAY AHEAD OF THE PRECIPITATION BAND. HOWEVER, LOCAL GUSTS
OF 40-50 MPH ARE POSSIBLE IN WIND PRONE AREAS ALONG HIGHWAY 395
SOUTH OF RENO THROUGH MONO COUNTY AND OUT INTO FAR WESTERN MINERAL
AND SOUTHERN LYON COUNTIES.
THE MAIN AREA OF SNOW SHOWERS DROPS SOUTH OF I-80 THIS EVENING,
ALTHOUGH RESIDUAL SHOWERS ARE POSSIBLE THROUGH TONIGHT ESPECIALLY
DOWNWIND OF PYRAMID LAKE AND PERHAPS LAKE TAHOE (THIS EVENING
ESPECIALLY). THE NAM HAS FINALLY BACKED OFF ON A SECOND SHOT OF
SNOW FOR CHURCHILL AND PERSHING COUNTIES TONIGHT, MORE IN LINE
WITH OTHER MODELS. ANY SNOW ACCUMULATIONS TONIGHT SHOULD REMAIN
LIGHT FOR WESTERN NEVADA, EXCEPT DOWNWIND OF PYRAMID LAKE WHERE
SEVERAL INCHES CANNOT BE RULED OUT. FOR THE SIERRA, WESTERN MONO
AND ALPINE COUNTIES COULD SEE ANOTHER 4-8 INCHES TONIGHT AS
UNSTABLE, MOIST UPSLOPE FLOW PUSHES SNOW ACROSS THE CREST INTO THE
EASTERN SIERRA.
CHRISTMAS DAY THROUGH THE WEEKEND WILL REMAIN COLD UNDER NORTH-
EAST FLOW AS THE TROUGH SLOWLY EXITS. LOWS WILL WE QUITE COLD BY
FRIDAY NIGHT AS CLEARING WORKS INTO THE REGION, WITH BELOW ZERO
READINGS LIKELY FOR THE COLDER, SNOW-COVERED VALLEYS OF WESTERN
NEVADA (OUTSIDE MAIN URBAN AREAS) AND CERTAINLY FOR THE SIERRA
VALLEYS. VALLEY INVERSIONS SHOULD BECOME QUITE STRONG BY SATURDAY
AND SATURDAY NIGHT AS A RIDGE BUILDS OVERHEAD. SNYDER
.LONG TERM...SUNDAY THROUGH WEDNESDAY...
FEW CHANGES MADE TO THE LONG TERM AS THE MODELS AND ENSEMBLES DEPICT
A MEAN RIDGE DEVELOPING ALONG THE COAST. THEY STILL DEPICT WEAK
WAVES MOVING THROUGH THE RIDGE OR DROPPING DOWN THE EAST SIDE INTO
THE MIDDLE OF NEXT WEEK. THE MONDAY SYSTEM LOOKS TO BE THE
STRONGEST, BUT IT REALLY IS QUITE WEAK OVERALL. THE MAIN DIFFERENCES
IN THE MODELS ARE THAT THE GFS IS A BIT FURTHER EAST WITH THE RIDGE
AND HAS THE SYSTEMS THAT DROP DOWN FROM THE NORTH INTO EASTERN
NEVADA. THE EC HAS THEM DROPPING INTO WESTERN NEVADA LIKE INSIDE
SLIDERS. HAVE USED A BLEND OF ALL GUIDANCE AS TRACKING THESE
INDIVIDUAL WAVES IS FUTILE AT BEST 5-7 DAYS OUT.
SUNDAY WILL STILL BE COLD IN THE VALLEYS UNDER A STRONG INVERSION
WHILE MTNS WARM. WITH THE MONDAY SYSTEM, THE BEST CHANCE OF SNOW
SHOWERS LOOKS TO BE IN THE SIERRA FROM TAHOE NORTH AND ALONG THE
OREGON BORDER. IT WILL ALSO HELP TO IMPROVE MIXING A BIT WITH COOLER
TEMPS ALOFT. TUESDAY AND WEDNESDAY, TWO MORE WEAK SYSTEMS WILL DROP
IN FROM THE NORTH. FOR NOW, HAVE KEPT IN A SLIGHT CHANCE OF SHOWERS
FOR TUESDAY ACROSS THE NORTH AND LEFT WEDNESDAY DRY. HAVE GONE WITH
A SLOW WARMING TREND, ESPECIALLY IN THE MOUNTAINS DUE TO BETTER
MIXING. HOWEVER, IF THERE IS ENOUGH SNOW COVER LEFT BY WEDNESDAY IN
WRN NV VALLEYS, THEY COULD BE TRAPPED UNDER A STRONG INVERSION
AGAIN. WALLMANN
&&
.AVIATION...
MAIN CONCERN IS THE SHSN MOVING THROUGH THE SIERRA AND WESTERN
NEVADA TODAY. IFR CONDS THRU 21-00Z FOR KTRK/KTVL THEN SOME MVFR
CONDS THRU 06Z BEFORE IMPROVING. KRNO/KCXP 2-3 HR PERIOD OF IFR
CONDS BETWEEN 15-20Z WITH OCNL MVFR 20-01Z IN -SHSN. KMMH IFR
CONDS 18-01Z THEN GRADUALLY IMPROVING AS WELL. RUNWAY ACCUMS STILL
LOOK TO BE AROUND 6" KTRK/KTVL 2-4" KRNO/KCXP AND 4-6" FOR KMMH.
EXPECT ALL TERMINALS VFR AFTER 09Z FRI.
OTHER CONCERN IS WINDS WITH RIDGE GUSTS 60 KTS ATTM. SOME LLWS THIS
MORNING THRU 15-17Z BEFORE SNOW COMMENCES AND WINDS CLOSER TO
SURFACE ABATE. OTHERWISE SFC WND GUSTS TO 25 KTS MOST LIKELY AT ALL
TERMINALS FROM S-SW THRU 03Z. EXCEPTION WILL BE KMMH WHERE WNW FLOW
ALOFT ALIGNS BETTER AND PEAK GUSTS TO 40-45 KTS POSSIBLE 15-03Z.
WALLMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING NVZ002.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ005.
WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 10 PM PST THIS
EVENING NVZ001-003-004.
CA...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ071-072.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING CAZ070.
WINTER STORM WARNING FROM 10 AM THIS MORNING TO 4 AM PST FRIDAY
CAZ073.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1010 AM EST THU DEC 24 2015
.SYNOPSIS...
LOW PRESSURE MOVING THROUGH CANADA WILL DRAG A COLD FRONT ACROSS
THE REGION TODAY. THE FRONT WILL SLOWLY SAG SOUTH OF THE REGION
LATE TONIGHT...AND TOWARDS THE MID ATLANTIC STATES ON CHRISTMAS
AS HIGH PRESSURE BUILDS IN FROM THE NORTH. UNSETTLED WEATHER WILL
RETURN FOR THE WEEKEND AND INTO NEXT WEEK AS A SERIES OF STORM
SYSTEMS MOVE ACROSS.
&&
.NEAR TERM /THROUGH TONIGHT/...
A BREEZY AND INCREDIBLY WARM DAY TODAY IS EXPECTED (ABOUT 30
DEGREES ABOVE SEASONABLE).
PHASED SHORTWAVE PIVOTS INTO QUEBEC TODAY...WHILE DEEP TROUGHING
RE-ESTABLISHES ACROSS THE WESTERN US THROUGH TONIGHT.
MEANWHILE...BERMUDA RIDGING REMAINS IN CONTROL TO THE
EAST...CONTINUING THE DEEP SW FLOW INTO THE REGION.
AT THE SURFACE...LOW PRESSURE CONTINUES TO TRACK TO HUDSONS BAY
TODAY...WITH ITS WEAKENING TRAILING COLD FRONT APPROACHING THE
REGION LATE TODAY INTO THIS EVENING. HIGHER RES MODELS INDICATING
POTENTIAL FOR A PRE-FRONTAL TROUGH DEVELOPING ACROSS WESTERN
PORTIONS OF THE TRI-STATE THIS AFTERNOON.
PATCHY OR AREAS OF FOG...MAINLY ALONG NEARSHORE LOCATIONS...COULD
HOLD WITH POOR VISIBILITIES INTO THE AFTERNOON WITH MARINE LAYER.
AWAY FROM MARINE INFLUENCE...RAPID IMPROVEMENT IN VSBY HAS BEEN
OBSERVED.
HIGH-RES NCAR ENSEMBLE AND HRRR DOING A FAIRLY GOOD JOB OF
PICKING UP ON SHOWER ACTIVITY ON NOSE OF DEVELOPING 55-60 KT LLJ.
THIS ACTIVITY AND REMNANTS OF PA CONVECTIVE LINE SHOULD TRANSLATE
FROM SW TO NE THROUGH THE COASTAL REGION LATE THIS MORNING INTO
EARLY AFTERNOON AHEAD OF A PRE-FRONTAL TROUGH. THUNDER HAS BEEN
OBSERVED JUST TO THE SOUTH. MARGINAL INSTABILITY (POTENTIALLY
SURFACE BASED ACROSS NE NJ/LOWER HUD) STILL EXISTS...BUT NOT MUCH
FORCING OR CONVERGENCE WITH THE APPROACHING COLD FRONT. SO SHOWER
POTENTIAL APPEARS TO BE LOW CHANCE TO SLIGHT...WITH LOW CONFIDENCE
ON ANY THUNDER BASED ON THE WEAK FORCING. BETTER CHANCE OF THUNDER
LOOKS TO BE SOUTH OF THE TRI- STATE. BASED ON WIND PROFILE...GUSTY
WINDS OF 40+ MPH COULD ACCOMPANY ANY HEAVY SHOWER OR TSTM
ACTIVITY.
IN TERMS OF WINDS TODAY...950 HPA WINDS OF 35 TO 40 KT ARE
EXPECTED...BUT MIXING IS THE CHALLENGE IN FORECASTING WIND
SPEEDS. SUSTAINED SE WINDS OF 10 TO 20 MPH WITH PEAK WINDS GUSTS
OF 25 TO 30 MPH LIKELY CONTINUE INTO EARLY
AFTERNOON...PARTICULARLY CITY/COAST. IF WE DO SEE SOME BREAKS OF
SUN AND RESULTANT INCREASED MIXING...SUSTAINED WINDS OF 20 TO 25
MPH AND GUSTS 35 TO 40 MPH ARE POSSIBLE AWAY FROM MARINE
INFLUENCE. THIS IS A LOW PROB...ESPECIALLY GIVEN SATELLITE TRENDS.
MAX TEMPS WILL REMAIN A CHALLENGE THIS AFTERNOON. LOW SUN
ANGLE...ABUNDANT CLOUD COVER...AND MIXING LIMITED TO 950
HPA...WILL LIMIT POTENTIAL HEATING. BUT RECORD TEMPS IN THE UPPER
60S TO LOWER 70S ARE EXPECTED FOR MOST OF THE REGION. A LOW
POTENTIAL FOR MID TO UPPER 70S NYC/NJ METRO...IF BREAKS OF SUN ARE
REALIZED.
TONIGHT...MODELS HAVE TRENDED SLOWER WITH COLD FRONTAL PASSAGE.
WITH MODELS SIGNALING WEAK DAYTIME CONVECTION INDUCED VORTS
TRACKING IN THE SW FLOW ALOFT...WITH LINGERING SHOWER THREAT
ACROSS NYC/NJ METRO AND LONG ISLAND INTO THE OVERNIGHT.
OTHERWISE...UNSEASONABLY MILD CONDITIONS EXPECTED TO CONTINUE WITH
LOWS GENERALLY IN THE 50S CITY/COAST AND 40S INTERIOR. LIGHT NW
FLOW EXPECTED IN THE WAKE OF THE FRONT...WITH SOME DRIER AIR
TRYING TO ADVECT IN. AMOUNT OF CLOUD COVER ALOFT WILL DETERMINE
DENSE FOG COVERAGE...BUT POTENTIAL EXISTS FOR AT LEAST PATCHY
DENSE FOG.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
MODELS COMING INTO BETTER AGREEMENT WITH CHRISTMAS INTO SATURDAY
PERIOD...WITH TROUGHING CONTINUING TO DEEPEN INTO THE SW US AND
BERMUDA HIGH SLOWLY DRIFTING SW TOWARDS FLORIDA. THIS WILL
CONTINUE TO PLACE THE REGION UNDER A DEEP SW PAC/SUB TROPICAL
FLOW.
AT THE SURFACE...APPEARS TO BE BETTER AGREEMENT WITH WEAK RIDGING
BUILDING INTO THE REGION ON CHRISTMAS DAY...PUSHING TODAYS COLD
FRONT TO THE MID ATLANTIC. THE SUBSIDENCE AND LOW-MID LEVEL
DRYING SHOULD PRESENT A DRY...AND ANOTHER RECORD BREAKING WARM
DAY. A PERIOD OF MOSTLY SUNNY SKIES LIKELY AFTER MORNING
STRATUS/FOG BURN OFF AND BEFORE HIGH CLOUD START TO STREAM IN IN
THE AFTERNOON.
MODELS CONVERGING ON AN INCREASING CHANCE FOR RAIN FRIDAY NIGHT INTO
SAT. AS THE WESTERN TROUGH APPROACHES THE CENTRAL US...DECENT
AGREEMENT IN A SERIES OF LOW PRESSURE WAVES BEGIN TO DEVELOP FROM
THE GULF COAST UP THE MISSISSIPPI RIVER VALLEY...LIFTING THE WARM
FRONT ACROSS THE MID-ATLANTIC UP TOWARDS THE REGION. POTENTIAL
FOR A FEW PERIODS OF LIGHT TO MODERATE RAIN AS SERIES OF WEAK
WAVES RIDE ALONG THE WARM FRONT INDUCED BY SOUTHERN STREAM
ENERGIES ROUNDING THE RIDGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MODELS DIFFER WITH THE POSITION AND TIMING OF A SERIES OF FRONTAL
PASSAGES AND LOW PRESSURE SYSTEMS ASSOCIATED WITH THEM...BUT
GENERALLY A MILD AND UNSETTLED PATTERN. MONDAY HAS THE BEST
CHANCE OF REMAINING DRY AS HIGH PRESSURE BUILDING IN FROM THE
NORTH WOULD APPEAR TO BE STRONG ENOUGH TO SUPPORT IT. TUESDAY HAS
THE BEST CHANCE OF SEEING PCPN...BUT WILL CAP POPS AT CHC DUE TO
THE UNCERTAINTY. FOR LATE MONDAY NIGHT INTO TUESDAY
MORNING...THERMAL PROFILES COULD SUPPORT A WINTRY MIX FOR THE
NORTHERN FRINGE ZONES.
TEMPERATURES THROUGH THE LONG TERM MAINLY WARMER THAN NORMAL.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
A WARM FRONT JUST NORTH OF THE REGION WILL PUSH NORTH THROUGH THE
MORNING AS SOUTHWESTERLY WIND INCREASES TO 10 TO 15 KT WITH GUSTS
TO AROUND 20 KT.
A COLD FRONT ACROSS WESTERN PENNSYLVANIA WILL APPROACH FROM THE WEST
THIS AFTERNOON...WILL MOVE THROUGH THE TERMINALS LATE THIS AFTERNOON
INTO EARLY THIS EVENING.
AT THE NYC METRO TERMINALS VFR CONDITIONS ARE EXPECTED MUCH OF THE
TIME UNTIL THIS AFTERNOON. HOWEVER...CONDITIONS ARE VARYING AND AT
TIMES MVFR CEILINGS...AND MAYBE IFR...WILL BE POSSIBLE. OUTSIDE THE
METRO TERMINALS VARIABLE CONDITIONS FROM MVFR TO VFR LIKELY.
AT THIS TIME VFR CONDITIONS ARE EXPECTED TO PREDOMINATE WITH
MVFR POSSIBLE AT TIMES UNTIL LATER THIS AFTERNOON.
WITH THE UNCERTAINTY AND VARIABILITY IN THE FORECAST
CONFIDENCE IS LOW.
LOW LEVEL JET WINDS AT 2KFT EXPECTED TO BE SW AT 40-45 KT THROUGH
THE MORNING AND INTO EARLY AFTERNOON.
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)
KJFK FCSTER COMMENTS: ANY SOUTH TO SOUTHWEST WIND GUSTS ARE EXPECTED
TO BE INTERMITTENT. VFR MOST OF THE TIME INTO THIS AFTERNOON WITH
MVFR CEILINGS AND A LOW CHANCE OF MVFR IN FOG.
KLGA FCSTER COMMENTS: VFR MOST OF THE TIME WITH A CHANCE OF MVFR
CEILINGS THIS MORNING. VISIBILITIES RESTRICTIONS ARE NOT EXPECTED
UNTIL THIS AFTERNOON. SOUTHWESTERLY GUSTS 20-25KT INTO THIS AFTERNOON.
KEWR FCSTER COMMENTS: VFR MOST OF THE TIME WITH A CHANCE OF MVFR
CEILINGS THIS MORNING. VISIBILITIES RESTRICTIONS ARE NOT EXPECTED
UNTIL THIS AFTERNOON. SOUTHWESTERLY GUSTS 20-25KT INTO THIS
AFTERNOON.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH
IMPLIES SLANT RANGE VISIBILITY 3-5SM OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: VFR MOST OF THE TIME WILL A CHANCE OF MVFR
CEILINGS...MAINLY THIS MORNING. VISIBILITIES RESTRICTIONS ARE NOT
EXPECTED UNTIL THIS AFTERNOON. SOUTHWESTERLY GUSTS AROUND 20 KT
BECOME MORE FREQUENT LATER THIS MORNING...AND CONTINUE INTO THIS
AFTERNOON.
KHPN FCSTER COMMENTS: MVFR CONDITIONS ARE EXPECTED TO IMPROVE TO VFR
LATER THIS MORNING AS A WARM FRONT MOVES FARTHER TO THE NORTH. THEN
AT TIMES MVFR CEILINGS WILL BE POSSIBLE...WITH A CHANCE OF IFR
CEILINGS INTO THIS AFTERNOON. LOW FORECAST CONFIDENCE.
KISP FCSTER COMMENTS: CURRENTLY...IFR CEILINGS WITH MVFR
VISIBILITIES IN FOG...MAY IMPROVE BRIEFLY TO VFR THIS MORNING. LOW
CONFIDENCE. GUSTS MAY NOT BE AS FREQUENT AS INDICATED IN THE TAF.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRIDAY...IFR POSSIBLE IN THE MORNING...MAYBE INTO THE AFTERNOON.
.SATURDAY-SUNDAY...MVFR OR LOWER POSSIBLE IN -RA.
.MONDAY...SLIGHT CHANCE OF -SHRA WITH MVFR OR LOWER.
&&
.MARINE...
WITH PROLONGED SOUTHERLY FETCH...SEAS ON THE OCEAN WILL STAY
ELEVATED. SCA REMAINS IN EFFECT THERE AS WINDS TOO HAVE BEEN GUSTING
TO 25-30 KT. OCCASIONAL GUSTS TO 25 KT ON REMAINDER OF WATERS.
THE WINDS WILL LOWER TONIGHT AND FRIDAY WHILE OCEAN SEAS WILL
LIKELY STAY ELEVATED WITH CONTRIBUTING SWELL.
WITHOUT MUCH OFFSHORE FLOW IN THE FORECAST...THE HIGHER OCEAN SEAS
MAY VERY WELL LINGER INTO THIS WEEKEND. HOWEVER GOING INTO THE
WEEKEND...FORECAST OCEAN WAVE HEIGHTS ARE MORE MARGINAL FOR
SCA...RIGHT AROUND 5 FT FRIDAY NIGHT THROUGH SATURDAY NIGHT.
WITH ABUNDANT LOW-LEVEL MOISTURE OVER THE WATERS...WIDESPREAD
DENSE FOG WILL CONTINUE THROUGH THE DAY. THE DENSE FOG ADVISORY HAS
BEEN EXTENDED TO 6 PM FOR MOST WATERS.
WINDS WILL EVENTUALLY INCREASE...BUT GUSTS TO 25KT APPEAR TO
BE LIMITED TO MAINLY THE OCEAN SUNDAY NIGHT AND MONDAY. THERE IS A
CHANCE THAT 25KT GUSTS OCCUR ON THE EASTERN SOUND AS WELL.
&&
.HYDROLOGY...
ADDITIONAL LIGHT TO MODERATE RAINFALL POSSIBLE THIS WEEKEND. A
SIGNIFICANT RAINFALL IS POSSIBLE EARLY NEXT WEEK.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS FOR DECEMBER 24TH HAVE ALREADY BEEN SET AT
MOST OF THE CLIMATE SITES SO FAR. SEE BELOW FOR THE HIGHS SO FAR AND
THE FINAL HIGH TEMPERATURES WE ARE FORECASTING LATER TODAY.
LOCATION HIGH YEAR FORECAST
NEWARK 70 2015 75
BRIDGEPORT 61 2015 66
CENTRAL PARK 70 2015 74
LAGUARDIA 69 2015 73
KENNEDY 61 2015 69
ISLIP 62 2015 66
HERE ARE THE HIGH TEMPERATURE RECORDS AND FORECAST HIGHS
FOR DECEMBER 25...CHRISTMAS DAY...
LOCATION HIGH YEAR FORECAST
NEWARK 69 1964 67
BRIDGEPORT 59 1964 63
CENTRAL PARK 64* 1982 66
LAGUARDIA 63 2014 66
KENNEDY 58 1982 65
ISLIP 56 2014 64
*ALSO OCCURRED IN PREVIOUS YEARS
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ338.
DENSE FOG ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ330-335-
340-345-350-353-355.
SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...NV
NEAR TERM...NV/PW
SHORT TERM...NV/PW
LONG TERM...JC
AVIATION...JM/MET
MARINE...JM/PW
HYDROLOGY...NV
CLIMATE...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
724 AM EST THU DEC 24 2015
.SYNOPSIS...
UNUSUALLY WARM DECEMBER WEATHER WILL CONTINUE FOR THE NEXT FEW
DAYS...PROBABLY BREAKING MANY RECORDS. WET WEATHER WILL ACCOMPANY
THE WARMTH THIS WEEKEND. FOR NEXT WEEK...LOOKING AT AN ACTIVE
WEATHER PATTERN WITH THE POTENTIAL FOR A WINTRY MIX AT TIMES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
724 AM UPDATE...
FORECAST REMAINS LARGELY ON TRACK THIS MORNING. MADE SOME TWEAKS
TO REFLECT OBSERVED TRENDS. AREAS OF FOG THIS MORNING. LOOKS LIKE
WE SHOULD SEE ONE MORE ROUND OF SHOWERS ALONG THE SOUTH COAST
LATER THIS MORNING. LATEST RUNS OF THE HRRR APPEAR TO HAVE A GOOD
HANDLE ON THIS.
PREVIOUS DISCUSSION...
HEAVY RAIN HAS MOVED OFFSHORE WHILE THE WARM FRONT CONTINUES TO
SURGE NORTHWARD. WARM FRONT HAS CREPT INTO PARTS OF RHODE ISLAND
AND SOUTHEASTERN MASSACHUSETTS WHERE TEMPERATURES HAVE SOARED INTO
THE UPPER 50S TO MID 60S! VERY HUMID AIR IS ACCOMPANYING THE FRONT
WITH DEWPOINTS IN THE SAME RANGE. BOTH TEMPERATURES AND DEWPOINTS
ARE HIGHLY ANOMALOUS FOR LATE DECEMBER. DEPENDING ON THE NORTHWARD
PROGRESSION OF THE WARM FRONT...WE MAY ACTUALLY HAVE NEAR RECORD
HIGH TEMPERATURES PRIOR TO SUNRISE FOR A FEW LOCATIONS.
IT IS A NEAR CERTAINTY THAT WE WILL HIT RECORD HIGHS TODAY ACROSS
SOUTHERN NEW ENGLAND AS 925MB TEMPS REACH 16C. AND THIS DESPITE
SHOWERS AND OVERCAST SKIES. IF WE WERE TO BREAK OUT INTO SOME
SUN...TEMPS COULD HIT THE LOW TO MID 70S. SINCE WE ARE EXPECTING
CLOUD COVER TO LINGER THROUGHOUT THE DAY...HIGHS WILL ONLY REACH THE
UPPER 60S TO AROUND 70. ONLY BEING RECORD SHATTERING TEMPERATURES.
THE NEXT ROUND OF SHOWERS WILL MOVE INTO SOUTHERN NEW ENGLAND LATER
THIS MORNING AND CONTINUE THROUGH THE AFTERNOON. THIS ROUND WILL BE
MUCH MORE SCATTERED IN NATURE THAN THE RAIN YESTERDAY AND LAST
NIGHT. PATCHY FOG SHOULD LIFT BY MID MORNING...EXCEPT OVER THE CAPE
AND ISLANDS WHERE IT IS LIKELY TO LINGER THROUGH MUCH OF THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
TONIGHT...THE COLD FRONT WILL MOVE THROUGH MUCH OF SOUTHERN NEW
ENGLAND STALLING ALONG THE SOUTH COAST. THIS WILL ALLOW LOW
CLOUDS...FOG...AND EVEN A FEW SHOWERS TO LINGER ON THE SOUTH COAST.
OTHERWISE...EXPECT GRADUALLY CLEARING SKIES AND CONTINUED MILD
TEMPERATURES. LOW TEMPS ARE EXPECTED TO BE IN THE MID 40S TO MID
50S.
CHRISTMAS DAY...ONE OF THE QUIETER DAYS THIS WEEK AS HIGH PRESSURE
BUILDS INTO SOUTHERN NEW ENGLAND. THE MODELS DISAGREE ON WHETHER
THE FRONT REMAINS STALLED ALONG THE SOUTH COAST. THE NAM IS THE
FARTHEST NORTH WITH THE FRONT AND KEEPS LOW CLOUDS AND PERHAPS SOME
SHOWERS ALONG THE SOUTH COAST. HOWEVER...THE GFS AND ECMWF BOTH
PUSH THE FRONT OFFSHORE. SO KEEPING THE CLOUDS ALONG THE SOUTH
COAST...BUT LIMITING THE POPS. EXPECT MAINLY DRY WEATHER WITH
ANOTHER DAY OF WELL ABOVE NORMAL TEMPERATURES. THE RECORD HIGH FOR
PROVIDENCE MIGHT BE TIED OR EXCEEDED WITH CURRENT FORECAST
HIGHS...HOWEVER THE REMAINDER OF THE CLIMATE SITES RECORDS WILL
LIKELY REMAIN SAFE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
*/ HIGHLIGHTS...
- PERIODS OF WET WEATHER AND BREEZY WINDS FOR THIS WEEKEND
- POTENTIAL SERIES OF WINTER WEATHER STORMS NEXT WEEK
*/ OVERVIEW...
RATHER UNIFIED FLOW ALOFT EXPECTED TO BREAK UP INTO TWO SEPARATE
STREAMS LATE THIS WEEKEND. THIS WILL BE QUITE DIFFERENT FROM THE
RATHER STABLE PATTERN WE HAVE BEEN IN...WHICH FEATURED A BROAD
MID LEVEL TROUGH OVER THE WESTERN USA...AND A SUBTROPICAL RIDGE
ALONG THE EAST COAST. ULTIMATELY...THIS SHOULD MEAN OUR PRESENT
ACTIVE WEATHER PATTERN IS LIKELY TO CONTINUE. THE MOST NOTICEABLE
DIFFERENCE WILL BE THE RETURN TO MORE SEASONABLE TEMPERATURES...
WHICH IN TURN OPENS THE DOOR FOR SOME EPISODES OF WINTRY
PRECIPITATION.
24/00Z GUIDANCE SUITE REMAINS IN RELATIVELY GOOD AGREEMENT THROUGH
MONDAY...BEFORE DEVELOPING MORE SIGNIFICANT DIFFERENCES. WILL
FAVOR A CONSENSUS APPROACH TO SMOOTH OVER THE MINOR DIFFERENCES
THROUGH MONDAY...AND PROVIDE A MORE MIDDLE OF THE ROAD APPROACH
THEREAFTER...WHEN PREDICTABILITY IS NOT SO HIGH.
*/ DISCUSSION...
SATURDAY INTO SUNDAY...
AS NOTED BEFORE...EXPECTING A CLASSIC MATURE LOW PASSAGE JUST TO
OUR NORTH AND WEST. AT THE PRESENT TIME...STILL LOOKING LIKE AN
ALL- RAIN EVENT DURING THIS PORTION OF THE FORECAST. WHILE NOT
RAINING THE ENTIRE TIME...THE MOST LIKELY PERIOD FOR PRECIPITATION
LOOKS TO BE SATURDAY AFTERNOON INTO SUNDAY MORNING.
EXPECTING MORE SEASONABLE AIR TO PUSH INTO OUR REGION BEHIND A
COLD FRONT SUNDAY NIGHT.
NEXT WEEK...
THIS IS STILL LARGELY A LOW CONFIDENCE FORECAST FOR THE SPECIFICS.
HAVE MODERATE CONFIDENCE IN OVERALL TIMING FOR PRECIPITATION. JUST
NOT IN WHICH PRECIPITATION TYPES WE WILL SEE. WITH MORE SEASONABLE
TEMPERATURES EXPECTED...WE COULD FINALLY SEE SOME WINTRY
PRECIPITATION IN SOUTHERN NEW ENGLAND. REALISTICALLY...THIS COULD
INCLUDE POCKETS OF FREEZING RAIN OR SLEET. WITH SUCH LOW
CONFIDENCE IN TEMPERATURE PROFILES THOUGH...WILL LIMIT
PRECIPITATION TYPES TO RAIN...SNOW...OR A RAIN/SNOW MIX. THIS WILL
OBVIOUSLY NEED TO BE WATCHED OVER THE NEXT SEVERAL DAYS.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH FRIDAY/...
TODAY...HIGH CONFIDENCE. EXPECTING A GRADUAL IMPROVEMENT IN
CONDITIONS TO MVFR AS PATCHY FOG LIFTS LATER THIS MORNING. IFR
LIKELY LINGERS TOWARD THE SOUTH COAST...INCLUDING THE CAPE AND
ISLANDS. SCT -SHRA THIS AFTERNOON MAY BRIEFLY REDUCE CONDITIONS
TO MVFR. LLWS THIS MORNING FOR MOST AREAS...THEN BECOMING LIMITED
TO THE CAPE AND ISLANDS THIS AFTERNOON.
TONIGHT...HIGH CONFIDENCE. VFR FOR MUCH OF THE AREA. MVFR VSBYS
AND IFR CIGS LIKELY ALONG THE IMMEDIATE SOUTH COAST...CAPE...AND
ISLANDS IN LOW CLOUDS AND PATCHY FOG.
CHRISTMAS DAY...HIGH CONFIDENCE. QUICK IMPROVEMENT TO VFR
CONDITIONS ALL LOCATIONS.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN
EXACT TIMING. LLWS LIKELY THROUGH 18Z.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN
EXACT TIMING. LLWS LIKELY THROUGH 15Z.
OUTLOOK /FRIDAY NIGHT THROUGH MONDAY/...
SATURDAY INTO SUNDAY...MODERATE CONFIDENCE.
CONDITIONS DETERIORATING TO A MIX OF MVFR-LIFR. WORST CONDITIONS
SATURDAY NIGHT INTO SUNDAY WITH LIKELIHOOD OF +RA...LOW CIGS AND
FOG. BREEZY SOUTH WINDS...STRONGEST SUNDAY WITH GUSTS ALONG THE
S/SE COAST OF AROUND 25 KTS.
MONDAY...MODERATE CONFIDENCE.
MAINLY VFR AS A HIGH PRESSURE MOVES ACROSS NORTHERN NEW ENGLAND.
NORTH WINDS INCREASING.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH FRIDAY/...HIGH CONFIDENCE.`
SMALL CRAFT ADVISORIES CONTINUE THROUGH FOR ALL WATERS EXCEPT
BOSTON HARBOR AND NARRAGANSETT BAY THROUGH TODAY. AS SEAS AND
WINDS DIMINISH TONIGHT INTO TOMORROW WITH BUILDING HIGH
PRESSURE...ADVISORIES WILL DROP OFF FOR THE INNER WATERS.
HOWEVER...THEY WILL CONTINUE FOR THE SOUTHERN OUTER WATERS THROUGH
CHRISTMAS DAY.
OUTLOOK /FRIDAY NIGHT THROUGH MONDAY/...
SATURDAY INTO SUNDAY...MODERATE CONFIDENCE.
WARM FRONT MOVES NORTH OF THE WATERS SATURDAY NIGHT INTO
SUNDAY...BRINGING A PERIOD OF MODERATE RAIN ALONG WITH LIKELY LOW
CLOUDS AND FOG. SHOULD BE SOME VISIBILITY RESTRICTIONS. INCREASING
S WINDS...WITH THE STRONGEST SUNDAY. ROUGH SEAS LIKELY DEVELOPING
ACROSS THE OUTER COASTAL WATERS SUNDAY.
MONDAY...MODERATE CONFIDENCE.
BRIEF LULL PRECIPITATION-WISE DURING THE DAY. MAINLY NORTH WINDS
WITH GUSTS UP TO 25 KTS. THINKING MOST PRECIPITATION OVER THE
WATERS WILL BE IN THE FORM OF RAIN MONDAY NIGHT...BUT CAN NOT RULE
OUT AN INITIAL WINTRY MIX.
&&
.CLIMATE...
RECORD HIGH MINIMUM TEMPERATURES FOR TODAY 12/24...
BOSTON 44/2003
PROVIDENCE 45/1941
HARTFORD 43/1931
WORCESTER 43/2003
RECORD HIGH TEMPERATURES FOR TODAY 12/24...
BOSTON 61/1996
PROVIDENCE65/2015 - NEW RECORD - PREVIOUSLY 64/2014
HARTFORD59/1996 AND 1990
WORCESTER57/1996 AND 1990
RECORD HIGH MINIMUM TEMPERATURES FOR FRIDAY 12/25...
BOSTON 44/2014
PROVIDENCE 46/1979
HARTFORD 43/2014
WORCESTER 47/1964
RECORD HIGH TEMPERATURES FOR FRIDAY 12/25...
BOSTON 65/1889
PROVIDENCE63/2014
HARTFORD64/1964
WORCESTER60/1964
RECORD HIGH TEMPERATURES FOR SUNDAY 12/27...
BOSTON 61/1949
PROVIDENCE59/1973
HARTFORD60/1949
WORCESTER 58/1895
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST FRIDAY FOR ANZ231>234.
SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR ANZ235-237-
254>256.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ251.
&&
$$
SYNOPSIS...BELK/RLG
NEAR TERM...BELK/RLG
SHORT TERM...RLG
LONG TERM...BELK
AVIATION...BELK/RLG
MARINE...BELK/RLG
CLIMATE...STAFF
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
708 AM EST THU DEC 24 2015
.SYNOPSIS...
LOW PRESSURE MOVING THROUGH CANADA WILL DRAG A COLD FRONT ACROSS
THE REGION TODAY. THE FRONT WILL SLOWLY SAG SOUTH OF THE REGION
LATE TONIGHT...AND TOWARDS THE MID ATLANTIC STATES ON CHRISTMAS
AS HIGH PRESSURE BUILDS IN FROM THE NORTH. UNSETTLED WEATHER WILL
RETURN FOR THE WEEKEND AND INTO NEXT WEEK AS A SERIES OF STORM
SYSTEMS MOVE ACROSS.
&&
.NEAR TERM /THROUGH TONIGHT/...
A BREEZY AND INCREDIBLY WARM DAY TODAY (ABOUT 30 DEGREES ABOVE
SEASONABLE).
PHASED SHORTWAVE PIVOTS FROM THE UPPER GREAT LAKES INTO QUEBEC
TODAY...WHILE DEEP TROUGHING RE-ESTABLISHES ACROSS THE WESTERN US
THROUGH TONIGHT. MEANWHILE...BERMUDA RIDGING REMAINS IN CONTROL TO
THE EAST...CONTINUING THE DEEP SW FLOW INTO THE REGION.
AT THE SURFACE...STRONG GREAT LAKES LOW PRESSURE CONTINUES TO TRACK
UP TOWARDS HUDSONS BAY TODAY...WITH ITS WEAKENING TRAILING COLD
FRONT APPROACHING THE REGION LATE TODAY INTO THIS EVENING. HIGHER
RES MODELS INDICATING POTENTIAL FOR A PRE-FRONTAL TROUGH DEVELOPING
ACROSS WESTERN PORTIONS OF THE TRI-STATE THIS AFTERNOON.
AREAS OF FOG WITH VSBY 1/2 TO 1 MILE EXPECTED TO CONTINUE THROUGH
THE MORNING ACROSS LI AND CT IN ADVECTION FOG. A GRADUAL
IMPROVEMENT IN VSBY EXPECTED THROUGH THE LATE MORNING...BUT
NEARSHORE LOCATIONS COULD HOLD WITH POOR VISIBILITIES INTO THE
AFTERNOON WITH MARINE LAYER. AWAY FROM MARINE INFLUENCE...SUCH AS
NYC/NJ METRO AND INTERIOR LOCATIONS...SHOULD SEE A MORE RAPID
IMPROVEMENT IN VSBY THIS MORNING.
HIGH-RES NCAR ENSEMBLE AND HRRR DOING A FAIRLY GOOD JOB OF
PICKING UP ON SHOWER ACTIVITY DEVELOPING OVER MID ATLANTIC ON
NOSE OF DEVELOPING 55-60 KT LLJ. THIS DEVELOPING ACTIVITY AND
REMNANTS OF PA CONVECTIVE LINE ARE EXPECTED TO TRANSLATE FROM SW
TO NE THROUGH THE REGION THIS MORNING INTO EARLY AFTERNOON AHEAD
OF A PRE- FRONTAL TROUGH. WITH WEAK ELEVATED INSTABILITY AND
FORCING...WILL INCLUDE A SLIGHT CHANCE OF THUNDER THIS MORNING.
THIS AFTERNOON...APPEARS LLJ FORCING AND WEAK SURFACE TROUGH
MOVES EAST. MARGINAL INSTABILITY (POTENTIALLY SURFACE BASED ACROSS
NE NJ/LOWER HUD) STILL EXISTS...BUT NOT MUCH FORCING OR
CONVERGENCE WITH THE APPROACHING COLD FRONT. SO SHOWER POTENTIAL
APPEARS TO BE LOW CHANCE TO SLIGHT...WITH LOW CONFIDENCE ON ANY
THUNDER BASED ON THE WEAK FORCING. BETTER CHANCE OF THUNDER LOOKS
TO BE SOUTH OF THE TRI- STATE. BASED ON WIND PROFILE...GUSTY WINDS
OF 40+ MPH COULD ACCOMPANY ANY HEAVY SHOWER OR TSTM ACTIVITY.
IN TERMS OF WINDS TODAY...950 HPA WINDS OF 35 TO 40 KT ARE
EXPECTED...BUT MIXING IS THE CHALLENGE IN FORECASTING WIND
SPEEDS. SUSTAINED SE WINDS OF 10 TO 20 MPH WITH PEAK WINDS GUSTS
OF 25 TO 30 MPH LIKELY CONTINUE INTO EARLY
AFTERNOON...PARTICULARLY CITY/COAST. IF WE DO SEE SOME BREAKS OF
SUN AND RESULTANT INCREASED MIXING...SUSTAINED WINDS OF 20 TO 25
MPH AND GUSTS 35 TO 40 MPH ARE POSSIBLE AWAY FROM MARINE
INFLUENCE. THIS IS A LOW PROB.
IN TERMS OF TEMPS TODAY...TEMPS ALREADY STARTING AT RECORD LEVELS
(LOWER TO UPPER 60S) AT 5 OF 6 FIRST ORDER CLIMATE SITES THIS
MORNING. LOW SUN ANGLE...ABUNDANT CLOUD COVER...AND MIXING LIMITED
TO 950 HPA...WILL LIMIT POTENTIAL HEATING. BUT RECORD TEMPS IN THE
UPPER 60S TO LOWER 70S ARE EXPECTED FOR MOST OF THE REGION. A LOW
POTENTIAL FOR MID TO UPPER 70S NYC/NJ METRO...IF BREAKS OF SUN
ARE REALIZED.
TONIGHT...MODELS HAVE TRENDED SLOWER WITH COLD FRONTAL PASSAGE.
WITH MODELS SIGNALING WEAK DAYTIME CONVECTION INDUCED VORTS
TRACKING IN THE SW FLOW ALOFT...WITH LINGER SHOWER THREAT ACROSS
NYC/NJ METRO AND LONG ISLAND INTO THE OVERNIGHT.
OTHERWISE...UNSEASONABLY MILD CONDITIONS EXPECTED TO CONTINUE WITH
LOWS GENERALLY IN THE 50S CITY/COAST AND 40S INTERIOR. LIGHT NW
FLOW EXPECTED IN THE WAKE OF THE FRONT...WITH SOME DRIER AIR
TRYING TO ADVECT IN. AMOUNT OF CLOUD COVER ALOFT WILL DETERMINE
DENSE FOG COVERAGE...BUT POTENTIAL EXISTS FOR AT LEAST PATCHY
DENSE FOG.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
MODELS COMING INTO BETTER AGREEMENT WITH CHRISTMAS INTO SATURDAY
PERIOD...WITH TROUGHING CONTINUING TO DEEPEN INTO THE SW US AND
BERMUDA HIGH SLOWLY DRIFTING SW TOWARDS FLORIDA. THIS WILL
CONTINUE TO PLACE THE REGION UNDER A DEEP SW PAC/SUB TROPICAL
FLOW.
AT THE SURFACE...APPEARS TO BE BETTER AGREEMENT WITH WEAK RIDGING
BUILDING INTO THE REGION ON CHRISTMAS DAY...PUSHING TODAYS COLD
FRONT TO THE MID ATLANTIC. THE SUBSIDENCE AND LOW-MID LEVEL
DRYING SHOULD PRESENT A DRY...AND ANOTHER RECORD BREAKING WARM
DAY. A PERIOD OF MOSTLY SUNNY SKIES LIKELY AFTER MORNING
STRATUS/FOG BURN OFF AND BEFORE HIGH CLOUD START TO STREAM IN IN
THE AFTERNOON.
MODELS CONVERGING ON AN INCREASING CHANCE FOR RAIN FRIDAY NIGHT INTO
SAT. AS THE WESTERN TROUGH APPROACHES THE CENTRAL US...DECENT
AGREEMENT IN A SERIES OF LOW PRESSURE WAVES BEGIN TO DEVELOP FROM
THE GULF COAST UP THE MISSISSIPPI RIVER VALLEY...LIFTING THE WARM
FRONT ACROSS THE MID-ATLANTIC UP TOWARDS THE REGION. POTENTIAL
FOR A FEW PERIODS OF LIGHT TO MODERATE RAIN AS SERIES OF WEAK
WAVES RIDE ALONG THE WARM FRONT INDUCED BY SOUTHERN STREAM
ENERGIES ROUNDING THE RIDGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MODELS DIFFER WITH THE POSITION AND TIMING OF A SERIES OF FRONTAL
PASSAGES AND LOW PRESSURE SYSTEMS ASSOCIATED WITH THEM...BUT
GENERALLY A MILD AND UNSETTLED PATTERN. MONDAY HAS THE BEST
CHANCE OF REMAINING DRY AS HIGH PRESSURE BUILDING IN FROM THE
NORTH WOULD APPEAR TO BE STRONG ENOUGH TO SUPPORT IT. TUESDAY HAS
THE BEST CHANCE OF SEEING PCPN...BUT WILL CAP POPS AT CHC DUE TO
THE UNCERTAINTY. FOR LATE MONDAY NIGHT INTO TUESDAY
MORNING...THERMAL PROFILES COULD SUPPORT A WINTRY MIX FOR THE
NORTHERN FRINGE ZONES.
TEMPERATURES THROUGH THE LONG TERM MAINLY WARMER THAN NORMAL.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
A COLD FRONT WILL APPROACH FROM THE WEST THIS AFTERNOON. IFR AND
BELOW CONDITIONS CONTINUE INTO THIS MORNING. DENSE FOG WILL AFFECT
SOME TERMINALS...BUT IT IS UNCERTAIN WHERE VSBYS WILL DROP TO 1/4 OR
BELOW BESIDES KHPN. ANY IMPROVEMENT THROUGH THE DAY IS EXPECTED TO
BE MARGINAL AT MOST ESPECIALLY FARTHER WEST AWAY FROM THE COAST.
THERE WILL BE A CONTINUED CHANCE OF SHOWERS GOING INTO THE DAY.
LOW LEVEL JET WINDS AT 2KFT EXPECTED TO BE SW AT 40-45 KT THROUGH
THE MORNING AND INTO EARLY AFTERNOON. AT THE SURFACE...A 10-15 KT
S-SW FLOW WILL START TO LOWER THIS AFTERNOON AND FURTHERMORE
TONIGHT. ANOTHER ROUND OF FOG AND LOW STRATUS WILL BE POSSIBLE
LATE TONIGHT.
WITH A LARGE GRADIENT OF CATEGORIES WITHIN A SMALL
DISTANCE...THE FORECAST HAS LOW CONFIDENCE ESPECIALLY WITH
CATEGORY.
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)
KJFK FCSTER COMMENTS: IMPROVEMENT COULD OCCUR EARLIER THAN
FORECAST. MVFR COULD OCCUR A FEW HOURS EARLIER THAN INDICATED.
KLGA FCSTER COMMENTS: UNCERTAIN ON HOW LONG CONDITIONS STAY VFR
THIS MORNING. CONDITIONS COULD DROP BACK TO MVFR/IFR AT TIMES.
KEWR FCSTER COMMENTS: UNCERTAIN ON HOW LONG CONDITIONS STAY VFR
THIS MORNING. CONDITIONS COULD DROP BACK TO MVFR/IFR AT TIMES.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH
IMPLIES SLANT RANGE VISIBILITY 3-5SM OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: UNCERTAIN ON HOW LONG CONDITIONS STAY
MVFR. AMENDMENTS LIKELY TO REFINE TIMING OF CATEGORICAL CHANGES.
KHPN FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE TIMING OF
IMPROVEMENT FROM VLIFR...WHICH COULD BE OFF BY A FEW HOURS.
KISP FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE TIMING
OF IMPROVEMENT FROM VLIFR...WHICH COULD BE OFF BY A FEW HOURS.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRIDAY...IFR POSSIBLE IN THE MORNING.
.SAT-SUN...MVFR OR LOWER POSSIBLE IN -RA.
.MON...SLIGHT CHANCE OF -SHRA WITH MVFR OR LOWER.
&&
.MARINE...
WITH PROLONGED SOUTHERLY FETCH...SEAS ON THE OCEAN WILL STAY
ELEVATED. SCA REMAINS IN EFFECT THERE AS WINDS TOO HAVE BEEN GUSTING
TO 25-30 KT. OCCASIONAL GUSTS TO 25 KT ON REMAINDER OF WATERS.
THE WINDS WILL LOWER TONIGHT AND FRIDAY WHILE OCEAN SEAS WILL
LIKELY STAY ELEVATED WITH CONTRIBUTING SWELL.
WITHOUT MUCH OFFSHORE FLOW IN THE FORECAST...THE HIGHER OCEAN SEAS
MAY VERY WELL LINGER INTO THIS WEEKEND. HOWEVER GOING INTO THE
WEEKEND...FORECAST OCEAN WAVE HEIGHTS ARE MORE MARGINAL FOR
SCA...RIGHT AROUND 5 FT FRIDAY NIGHT THROUGH SATURDAY NIGHT.
WITH ABUNDANT LOW-LEVEL MOISTURE OVER THE WATERS...WIDESPREAD
DENSE FOG WILL CONTINUE THROUGH THE DAY. THE DENSE FOG ADVISORY HAS
BEEN EXTENDED TO 6 PM FOR MOST WATERS.
WINDS WILL EVENTUALLY INCREASE...BUT GUSTS TO 25KT APPEAR TO
BE LIMITED TO MAINLY THE OCEAN SUNDAY NIGHT AND MONDAY. THERE IS A
CHANCE THAT 25KT GUSTS OCCUR ON THE EASTERN SOUND AS WELL.
&&
.HYDROLOGY...
BASIN AVG QPF FROM .75 TO 2 INCHES WAS NOTED ACROSS THE TRI-STATE
WITH THIS RAIN EVENT.
ADDITIONAL LIGHT TO MODERATE RAINFALL POSSIBLE THIS WEEKEND. A SIGNIFICANT
RAINFALL IS POSSIBLE EARLY NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
HIGH TIDES IN COMBINATION WITH RESIDUAL SURGE COULD CAUSE BRIEF
AND LOCALIZED MINOR COASTAL FLOODING ACROSS THE TYPICALLY
VULNERABLE LI SOUTH SHORE BAYS LOCALES DURING TIMES OF HIGH TIDE
THIS MORNING.
MINOR ATLANTIC OCEAN BEACH EROSION POSSIBLE...PARTICULARLY THIS
MORNING...WITH 5 TO 7 FT SOUTHERLY SWELLS AND TIDES RUNNING HIGH.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS FOR DECEMBER 24TH HAVE ALREADY BEEN SET AT
MOST OF THE CLIMATE SITES SO FAR. SEE BELOW FOR THE HIGHS SO FAR AND
THE FINAL HIGH TEMPERATURES WE ARE FORECASTING LATER TODAY.
LOCATION HIGH YEAR FORECAST
NEWARK 68 2015 75
BRIDGEPORT 61 2015 66
CENTRAL PARK 67 2015 74
LAGUARDIA 63 1990 73
KENNEDY 61 2015 69
ISLIP 62 2015 66
HERE ARE THE HIGH TEMPERATURE RECORDS AND FORECAST HIGHS
FOR DECEMBER 25...CHRISTMAS DAY...
LOCATION HIGH YEAR FORECAST
NEWARK 69 1964 67
BRIDGEPORT 59 1964 63
CENTRAL PARK 64* 1982 66
LAGUARDIA 63 2014 66
KENNEDY 58 1982 65
ISLIP 56 2014 64
*ALSO OCCURRED IN PREVIOUS YEARS
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ338.
DENSE FOG ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ330-335-
340-345-350-353-355.
SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...NV
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...JC
AVIATION...JM
MARINE...JM
HYDROLOGY...NV
TIDES/COASTAL FLOODING...NV
CLIMATE...JM
AREA FORECAST DISCUSSION
NWS NEW YORK NY
423 AM EST THU DEC 24 2015
.SYNOPSIS...
LOW PRESSURE MOVING THROUGH CANADA WILL DRAG A COLD FRONT ACROSS
THE REGION TODAY. THE FRONT WILL SLOWLY SAG SOUTH OF THE REGION
LATE TONIGHT...AND TOWARDS THE MID ATLANTIC STATES ON CHRISTMAS
AS HIGH PRESSURE BUILDS IN FROM THE NORTH. UNSETTLED WEATHER WILL
RETURN FOR THE WEEKEND AND INTO NEXT WEEK AS A SERIES OF STORM
SYSTEMS MOVE ACROSS.
&&
.NEAR TERM /THROUGH TONIGHT/...
A BREEZY AND INCREDIBLY WARM DAY TODAY (ABOUT 30 DEGREES ABOVE
SEASONABLE.
PHASED SHORTWAVE PIVOTS FROM THE UPPER GREAT LAKES INTO QUEBEC
TODAY...WHILE DEEP TROUGHING RE-ESTABLISHES ACROSS THE WESTERN US
THROUGH TONIGHT. MEANWHILE...BERMUDA RIDGING REMAINS IN CONTROL TO
THE EAST...CONTINUING THE DEEP SW FLOW INTO THE REGION.
AT THE SURFACE...STRONG GREAT LAKES LOW PRESSURE CONTINUES TO TRACK
UP TOWARDS HUDSONS BAY TODAY...WITH ITS WEAKENING TRAILING COLD
FRONT APPROACHING THE REGION LATE TODAY INTO THIS EVENING. HIGHER
RES MODELS INDICATING POTENTIAL FOR A PRE-FRONTAL TROUGH DEVELOPING
ACROSS WESTERN PORTIONS OF THE TRI-STATE THIS AFTERNOON.
AREAS OF FOG WITH VSBY 1/2 TO 1 MILE EXPECTED TO CONTINUE THROUGH
THE MORNING ACROSS LI AND CT IN ADVECTION FOG. A GRADUAL IMPROVEMENT
IN VSBY EXPECTED THROUGH THE LATE MORNING...BUT NEARSHORE LOCATIONS
COULD HOLD WITH POOR VISIBILITIES INTO THE AFTERNOON WITH MARINE
LAYER. AWAY FROM MARINE INFLUENCE...SUCH AS NYC/NJ METRO AND
INTERIOR LOCATIONS...SHOULD SEE A MORE RAPID IMPROVEMENT IN VSBY
THIS MORNING.
HIGH-RES ENSEMBLE AND HRRR INDICATING REMNANTS OF CONVECTIVE LINE
AND ADDITIONAL SHOWER ACTIVITY DEVELOPING THIS MORNING AND
TRANSLATING FROM W TO E THROUGH EARLY AFTERNOON AS 55-60 KT LLJ
TRANSLATE EAST AHEAD OF A PRE-FRONTAL TROUGH. WITH WEAK ELEVATED
INSTABILITY AND FORCING...WILL INCLUDE A SLIGHT CHANCE OF THUNDER
THIS MORNING. THIS AFTERNOON...APPEARS LLJ FORCING AND WEAK
SURFACE TROUGH MOVES EAST. MARGINAL INSTABILITY (POTENTIALLY
SURFACE BASED ACROSS NE NJ/LOWER HUD) STILL EXISTS...BUT NOT MUCH
FORCING OR CONVERGENCE WITH THE APPROACHING COLD FRONT. SO SHOWER
POTENTIAL APPEARS TO BE LOW CHANCE TO SLIGHT...WITH LOW CONFIDENCE
ON ANY THUNDER BASED ON THE WEAK FORCING. BETTER CHANCE OF THUNDER
LOOKS TO BE SOUTH OF THE TRI-STATE. BASED ON WIND PROFILE...GUSTY
WINDS OF 40+ MPH COULD ACCOMPANY ANY HEAVY SHOWER OR TSTMS
ACTIVITY.
IN TERMS OF WINDS...950 HPA WINDS OF 35 TO 40 KT ARE EXPECTED
TODAY...BUT MIXING IS THE CHALLENGE IN FORECASTING WIND SPEEDS.
SUSTAINED SE WINDS OF 10 TO 20 MPH WITH PEAK WINDS GUSTS OF 25 TO 30
MPH LIKELY. IF WE DO SEE SOME BREAKS OF SUN AND INCREASED
MIXING...SUSTAINED WINDS OF 20 TO 25 MPH AND GUSTS 35 TO 40 MPH ARE
POSSIBLE AWAY FROM MARINE INFLUENCE.
IN TERMS OF TEMPS...TEMPS ALREADY STARTING AT RECORD LEVELS (LOWER
TO UPPER 60S) AT 5 OF 6 FIRST ORDER CLIMATE SITES THIS MORNING. LOW
SUN ANGLE...ABUNDANT CLOUD COVER...AND MIXING LIMITED TO 950
HPA...WILL LIMIT POTENTIAL HEATING. BUT RECORD TEMPS IN THE UPPER
60S TO LOWER 70S ARE EXPECTED FOR MOST OF THE REGION...WITH
POTENTIAL FOR MID TO UPPER 70S NYC/NJ METRO IF BREAKS OF SUN ARE
REALIZED.
TONIGHT...MODELS HAVE TRENDED SLOWER WITH COLD FRONTAL PASSAGE.
WITH MODELS SIGNALING WEAK DAYTIME CONVECTION INDUCED VORTS
TRACKING IN THE SW FLOW ALOFT...WITH LINGER SHOWER THREAT ACROSS
NYC/NJ METRO AND LONG ISLAND INTO THE OVERNIGHT.
OTHERWISE...UNSEASONABLY MILD CONDITIONS EXPECTED TO CONTINUE WITH
LOWS GENERALLY IN THE 50S CITY/COAST AND 40S INTERIOR. LIGHT NW
FLOW EXPECTED IN THE WAKE OF THE FRONT...WITH SOME DRIER AIR
TRYING TO ADVECT IN. AMOUNT OF CLOUD COVER ALOFT WILL DETERMINE
DENSE FOG COVERAGE...BUT POTENTIAL EXISTS FOR AT LEAST PATCHY
DENSE FOG.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
MODELS COMING INTO BETTER AGREEMENT WITH CHRISTMAS INTO SATURDAY
PERIOD...WITH TROUGHING CONTINUING TO DEEPEN INTO THE SW US AND
BERMUDA HIGH SLOWLY DRIFTING SW TOWARDS FLORIDA. THIS WILL
CONTINUE TO PLACE THE REGION UNDER A DEEP SW PAC/SUB TROPICAL
FLOW.
AT THE SURFACE...APPEARS TO BE BETTER AGREEMENT WITH WEAK RIDGING
BUILDING INTO THE REGION ON CHRISTMAS DAY...PUSHING TODAYS COLD
FRONT TO THE MID ATLANTIC. THE SUBSIDENCE AND LOW-MID LEVEL
DRYING SHOULD PRESENT A DRY...AND ANOTHER RECORD BREAKING WARM
DAY. A PERIOD OF MOSTLY SUNNY SKIES LIKELY AFTER MORNING
STRATUS/FOG BURN OFF AND BEFORE HIGH CLOUD START TO STREAM IN IN
THE AFTERNOON.
MODELS CONVERGING ON AN INCREASING CHANCE FOR RAIN FRIDAY NIGHT INTO
SAT. AS THE WESTERN TROUGH APPROACHES THE CENTRAL US...DECENT
AGREEMENT IN A SERIES OF LOW PRESSURE WAVES BEGIN TO DEVELOP FROM
THE GULF COAST UP THE MISSISSIPPI RIVER VALLEY...LIFTING THE WARM
FRONT ACROSS THE MID-ATLANTIC UP TOWARDS THE REGION. POTENTIAL
FOR A FEW PERIODS OF LIGHT TO MODERATE RAIN AS SERIES OF WEAK
WAVES RIDE ALONG THE WARM FRONT INDUCED BY SOUTHERN STREAM
ENERGIES ROUNDING THE RIDGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MODELS DIFFER WITH THE POSITION AND TIMING OF A SERIES OF FRONTAL
PASSAGES AND LOW PRESSURE SYSTEMS ASSOCIATED WITH THEM...BUT
GENERALLY A MILD AND UNSETTLED PATTERN. MONDAY HAS THE BEST
CHANCE OF REMAINING DRY AS HIGH PRESSURE BUILDING IN FROM THE
NORTH WOULD APPEAR TO BE STRONG ENOUGH TO SUPPORT IT. TUESDAY HAS
THE BEST CHANCE OF SEEING PCPN...BUT WILL CAP POPS AT CHC DUE TO
THE UNCERTAINTY. FOR LATE MONDAY NIGHT INTO TUESDAY
MORNING...THERMAL PROFILES COULD SUPPORT A WINTRY MIX FOR THE
NORTHERN FRINGE ZONES.
TEMPERATURES THROUGH THE LONG TERM MAINLY WARMER THAN NORMAL.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
A COLD FRONT WILL APPROACH FROM THE WEST THIS AFTERNOON. IFR AND
BELOW CONDITIONS CONTINUE INTO THIS MORNING. DENSE FOG WILL AFFECT
SOME TERMINALS...BUT IT IS UNCERTAIN WHERE VSBYS WILL DROP TO 1/4 OR
BELOW BESIDES KHPN. ANY IMPROVEMENT THROUGH THE DAY IS EXPECTED TO
BE MARGINAL AT MOST. THERE WILL BE A CONTINUED CHANCE OF SHOWERS
GOING INTO THE DAY.
LOW LEVEL JET STILL PRESENT BUT THE CORE HAS PASSED TO THE EAST.
STILL...WINDS AT 2KFT EXPECTED TO BE SW AT 40-45 KT THROUGH MUCH OF
THE MORNING. AT THE SURFACE...A 10-15 KT S-SW FLOW WILL START TO
LOWER THIS AFTERNOON AND FURTHERMORE TONIGHT. ANOTHER ROUND OF FOG
AND LOW STRATUS WILL BE POSSIBLE LATE TONIGHT.
...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)
KJFK FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE TIMING OF
IMPROVEMENT FROM LIFR/IFR...WHICH COULD BE OFF BY A FEW HOURS.
KLGA FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE TIMING
OF IMPROVEMENT FROM LIFR/IFR...WHICH COULD BE OFF BY A FEW HOURS.
KEWR FCSTER COMMENTS: UNCERTAIN ON HOW LONG CONDITIONS STAY MVFR
THIS MORNING. AMENDMENTS LIKELY TO REFINE TIMING OF IMPROVEMENT FROM
IFR...WHICH COULD BE OFF BY A FEW HOURS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH
IMPLIES SLANT RANGE VISIBILITY 3-5SM OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: UNCERTAIN ON HOW LONG CONDITIONS STAY
MVFR/VFR. AMENDMENTS LIKELY TO REFINE TIMING OF IMPROVEMENT FROM
LIFR/IFR...WHICH COULD BE OFF BY A FEW HOURS.
KHPN FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE TIMING OF
IMPROVEMENT FROM VLIFR...WHICH COULD BE OFF BY A FEW HOURS.
KISP FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE TIMING
OF IMPROVEMENT FROM LIFR/IFR...WHICH COULD BE OFF BY A FEW HOURS.
.OUTLOOK FOR 09Z FRIDAY THROUGH MONDAY...
.FRIDAY...IFR POSSIBLE IN THE MORNING.
.SAT-SUN...MVFR OR LOWER POSSIBLE IN -RA.
.MON...SLIGHT CHANCE OF -SHRA WITH MVFR OR LOWER.
&&
.MARINE...
WITH PROLONGED SOUTHERLY FETCH...SEAS ON THE OCEAN WILL STAY
ELEVATED. SCA REMAINS IN EFFECT THERE AS WINDS TOO HAVE BEEN GUSTING
TO 25-30 KT. THE WINDS WILL LOWER TONIGHT AND FRIDAY WHILE OCEAN SEAS
WILL LIKELY STAY ELEVATED WITH CONTRIBUTING SWELL. OTHER WATERS WILL
STAY BELOW SCA THROUGH FRIDAY.
WITHOUT MUCH OFFSHORE FLOW IN THE FORECAST...THE HIGHER OCEAN SEAS
MAY VERY WELL LINGER INTO THIS WEEKEND. HOWEVER GOING INTO THE
WEEKEND...FORECAST OCEAN WAVE HEIGHTS ARE MORE MARGINAL FOR
SCA...RIGHT AROUND 5 FT FRIDAY NIGHT THROUGH SATURDAY NIGHT.
WITH ABUNDANT LOW-LEVEL MOISTURE OVER THE WATERS...WIDESPREAD
DENSE FOG WILL CONTINUE THROUGH THE DAY. THE DENSE FOG ADVISORY HAS
BEEN EXTENDED TO 6 PM FOR MOST WATERS.
WINDS WILL EVENTUALLY INCREASE...BUT GUSTS TO 25KT APPEAR TO
BE LIMITED TO MAINLY THE OCEAN SUNDAY NIGHT AND MONDAY. THERE IS A
CHANCE THAT 25KT GUSTS OCCUR ON THE EASTERN SOUND AS WELL.
&&
.HYDROLOGY...
BASIN AVG QPF FROM .75 TO 2 INCHES WAS NOTED ACROSS THE TRI-STATE
WITH THIS RAIN EVENT.
ADDITIONAL LIGHT TO MODERATE RAINFALL POSSIBLE THIS WEEKEND. A SIGNIFICANT
RAINFALL IS POSSIBLE EARLY NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
HIGH TIDES THIS MORNING IN COMBINATION WITH RESIDUAL SURGE COULD
CAUSE BRIEF AND LOCALIZED MINOR COASTAL FLOODING ACROSS THE
TYPICALLY VULNERABLE LI SOUTH SHORE BAYS LOCALES. SURGE OF 3/4 TO
1 1/2 FT WILL BE NEEDED TO REACH MINOR COASTAL FLOODING BENCHMARKS
THERE.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS FOR DECEMBER 24TH HAVE ALREADY BEEN SET AT
MOST OF THE CLIMATE SITES SO FAR. SEE BELOW FOR THE HIGHS SO FAR AND
THE FINAL HIGH TEMPERATURES WE ARE FORECASTING LATER TODAY.
LOCATION HIGH YEAR FORECAST
NEWARK 68 2015 75
BRIDGEPORT 61 2015 66
CENTRAL PARK 67 2015 74
LAGUARDIA 63 1990 73
KENNEDY 61 2015 69
ISLIP 62 2015 66
HERE ARE THE HIGH TEMPERATURE RECORDS AND FORECAST HIGHS
FOR DECEMBER 25...CHRISTMAS DAY...
LOCATION HIGH YEAR FORECAST
NEWARK 69 1964 67
BRIDGEPORT 59 1964 63
CENTRAL PARK 64* 1982 66
LAGUARDIA 63 2014 66
KENNEDY 58 1982 65
ISLIP 56 2014 64
*ALSO OCCURRED IN PREVIOUS YEARS
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ338.
DENSE FOG ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ330-335-
340-345-350-353-355.
SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...NV
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...JC
AVIATION...JM
MARINE...JM
HYDROLOGY...NV
TIDES/COASTAL FLOODING...NV
CLIMATE...JM
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
652 PM EST FRI DEC 25 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL BE NEARLY STATIONARY ACROSS DELMARVA AND
SOUTHERN NEW JERSEY TONIGHT AS A WEAK AREA OF LOW PRESSURE PASSES
OFF THE DELAWARE COAST. THE FRONTAL BOUNDARY WILL THEN PUSH
FURTHER SOUTH AS SIGNIFICANTLY COOLER HIGH PRESSURE SLIDES TO OUR
NORTH ON SATURDAY. LOW PRESSURE MOVING FROM THE OHIO VALLEY
SATURDAY NIGHT TO NEW ENGLAND SUNDAY WILL PULL THE FRONT NORTH AS
A STRONG WARM FRONT SUNDAY, BEFORE THE TRAILING COLD FRONT SLIDES
SOUTH ACROSS THE AREA SUNDAY NIGHT. STRONG AND COLD HIGH PRESSURE
BRIEFLY BUILDS TO OUR NORTH LATE MONDAY INTO EARLY TUESDAY, BEFORE
A SERIES OF LOW PRESSURE SYSTEMS AND FRONTAL BOUNDARIES AFFECT THE
AREA DURING THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A LINE OF HEAVIER RAIN SHOWERS...WITH A FEW WIDELY-SCATTERED
THUNDERSTORMS...IS DRAPED OVER THE NORTHERN DELMARVA AND FURTHER
EAST THROUGH SOUTHERN NEW JERSEY. IT APPEARS SOME OF THE HEAVIEST
RAIN SHOWERS ARE DIMINISHING IN INTENSITY BASED ON THE LATEST 88-D
SIGNATURES. THE HRRR CONTINUES TO INDICATE A REDUCTION OF SHOWER
ACTIVITY AFTER 00Z, AND THAT TREND IS REFLECTED IN THE CURRENT
GFE WEATHER GRIDS. WINDS ARE GENERALLY UNDER 5 MPH IN MOST
LOCATIONS, AND PATCHY FOG IS FORMING IN SOME PLACES. PREVIOUS FCST
IS ON TRACK AND ONLY MINOR TWEAKS WERE MADE WITH THIS 630 PM
UPDATE THAT INCLUDED AN INCREASE IN POPS OVER SOUTHEASTERN PA AND
ADJANCENT SECTIONS OF NJ...AS WELL AS MINOR ADJUSTMENTS TO WIND
DIRECTION IN SOME SPOTS.
PREV NEAR TERM DISCUSSION BELOW...
FGEN WITH THE FRONTAL BOUNDARY AND PWAT OF 1.5" PLUS CONVECTIVE
INSTABILITY IS YIELDING A PERIOD OF HEAVY SHOWERS AND ISOLATED
TSTMS THROUGH ABOUT 02Z FOR THE DELMARVA INTO S NJ AND FAR SE PA.
THIS WHIPS OFF TO THE EAST QUICKLY THIS EVENING AND I PROBABLY
DIDNT END IT SOON ENOUGH. THEN WE AWAIT AN INFLUX OF MUCH COOLER
AIR FROM THE NE AS A WAVE LOW PRESSURE GENERATING THIS EVENINGS
RAIN MOVES EWD OUT TO SEA AND A 1035MB HIGH SLIDES INTO SE CANADA
BY MORNING.
WPC QPF FROM 2512 USED.
PATCHY OR AREAS OF FOG BUT PROBABLY NOT AS DENSE AS THAT OF THIS
MORNING.
USED THE SIGNIFICANTLY COOLER NAM BL TEMPS FOR THE LATE NIGHT TEMP
SLIDE AND OTRW 50 50 BLENDED 12Z/25 GFS/NAM FOR THE ELEMENTS EXCEPT
MATCHLAV FOR MILDER TT/TD THIS EVENING.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
MUCH MUCH COOLER AS BOUNDARY LAYER TEMPS DOWN ABOUT 10C FROM FRIDAY
(20F COOLER AT 18Z FROM THE PHILLY AREA TO KACY SOUTHWARD)! THE
FRONT WILL BE SETTLED JUST TO OUR SOUTH. MOISTURE WILL BE OVERRIDING
THE BOUNDARY TO OUR SOUTH, (WEAK INSTABILITY BURST) AND AS A SHORT
WAVE/VORTICITY IMPULSES LIFTS NORTHWARD ACROSS THE AREA, RAINFALL
WILL LIKELY AGAIN BEGIN SPREADING ACROSS THE AREA.
CALLED IT RAIN WITH A CHANCE OF DRIZZLE. TEMPS MAY REMAIN IN THE
45 TO 50F RANGE ALL DAY PHL NORTH. ECMWF AND GFS ARE WARMER BUT I
DONT THINK THOSE MODELS ARE HANDLING THE UNDERUNNING VERY WELL.
THIS COULD BE A DEFICIENCY IN MY FCST APPROACH. RIGHT NOW... MAX
TEMPS AT PHL WILL BE AT MIDNIGHT (12 AM SATURDAY) AND A DAMP DANK
GUSTY NE WIND TYPE OF DAY EXPECTED SATURDAY I-95 EWD...A LITTLE
LESS WIND TO THE WEST OF I-95.
SO OTHER THAN RELYING MORE HEAVILY ON THE NAM FOR SATURDAYS TEMPS,
USED A 50 50 BLEND OF THE 12Z/25 GFS/NAM MOS GUIDANCE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
AN EXTENDED PERIOD OF UNSETTLED WEATHER WITH ANOTHER ROUND OF
RECORD HEAT ON SUNDAY THEN FOLLOWED WITH POSSIBLE WINTRY
PRECIPITATION LATER IN THE WEEK.
SATURDAY NIGHT, THE FRONTAL BOUNDARY WILL BE LIFTING NORTHWARD AS
A WARM FRONT AS AN AREA OF LOW PRESSURE MOVES OUT OF THE GREAT
LAKES REGION. PRECIPITATION WILL SPREAD NORTHWARD ACROSS THE
REGION BUT OVERALL RAINFALL AMOUNTS ARE EXPECTED TO BE RELATIVELY
LIGHT.
ON SUNDAY, WARMER AIR AGAIN SURGES ACROSS THE REGION IN THE WAKE
OF THE WARM FRONT AND MOST LOCATIONS WILL AGAIN SEE RECORD HIGH
TEMPERATURES. SOME LOCATIONS WILL LIKELY BREAK THE PREVIOUS
RECORD BY 3+ DEGREES. THERE WILL BE A CHANCE OF SHOWERS ON SUNDAY
AS WELL AS INTO SUNDAY NIGHT AS COLDER AIR THEN SURGES BACK INTO
THE REGION
ON MONDAY, HIGH PRESSURE BUILDS INTO THE REGION WITH SIGNIFICANTLY
COLDER AIR AND SETTING UP THE POTENTIAL FOR SOME WINTRY WEATHER.
THE NEXT STORM SYSTEM AFFECTS OUR REGION MONDAY NIGHT INTO
TUESDAY. BOTH THE OPERATIONAL GFS AND THE ENSEMBLE GUIDANCE HAVE
TRENDED WARMER OVER THE PAST SEVERAL MODEL CYCLES, SO WINTRY
PRECIPITATION HAS BEEN CONFINED FURTHER NORTH, MAINLY INTO THE
POCONOS AND PORTIONS OF THE LEHIGH VALLEY AND EXTREME NORTHERN NEW
JERSEY. THE POTENTIAL FOR SNOW WITH THIS SYSTEM HAS LESSENED, WITH
SLEET AND FREEZING RAIN BEING THE MAIN WINTER PRECIPITATION TYPES.
ANOTHER AREA OF HIGH PRESSURE THEN BUILDS INTO THE REGION ON
WEDNESDAY WITH TEMPERATURES MORE TYPICAL OF THIS TIME OF YEAR.
THERE IS THE POTENTIAL FOR ANOTHER STORM TO AFFECT THE REGION AS
WE APPROACH THE NEW YEAR. MAINLY RAIN IS MENTIONED IN THE FORECAST
AT THIS POINT, BUT ADDITIONAL WINTRY PRECIPITATION MAY BE
POSSIBLE, ONCE THE STORM TRACK FURTHER RESOLVES ITSELF.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THROUGH 05Z THIS EVENING...VFR NORTH. MVFR AND IFR CONDS IN HEAVY
SHOWERS AND ISOLATED TSTMS SOUTH. VARIABLE WIND UNDER 5 KT.
LATE TONIGHT AFTER 05Z/26...IFR OR MVFR CONDITIONS IMPROVING TO
VFR OR MVFR CIGS EVERYWHERE WITH A GUSTY NORTHEAST WIND OF 15 TO
25 KT (EXCEPT GUSTS PROBABLY UNDER 20 KT VCNTY KRDG) BY 10Z
SATURDAY.
SATURDAY...VFR CIGS AND A PROBABLE PERIOD OF MVFR CONDS
IN BANDS/PERIODS RAIN OR DRIZZLE. NORTHEAST WIND GUST 15-25 KT.
OUTLOOK...
SATURDAY NIGHT...PERIODS OF RAIN WITH LOW CIGS AND VSBYS.
SUNDAY-SUNDAY NIGHT...CHANCE OF SHOWERS. IMPROVING CIGS AND VSBYS.
MONDAY...VFR CONDITIONS AND GUSTY WINDS EARLY IN THE DAY. LOWERING
CONDITIONS LATER IN THE DAY WITH INCREASING CHANCE OF
PRECIPITATION.
MONDAY NIGHT-TUESDAY...LOW CIGS AND VSBYS WITH PRECIPITATION
SPREADING NORTHWARD ACROSS THE AREA. WINTRY PRECIPITATION
POSSIBLE, MAINLY FOR NORTHEAST PENNSYLVANIA AND NORTHERN NEW
JERSEY. GUSTY WINDS LIKELY.
WEDNESDAY...VFR CONDITIONS.
&&
.MARINE...
SCA FOR WIND AND OR SEAS LATE TONIGHT INTO SATURDAY EVENING. MWW
HAS THE DETAILS BEHIND THE DEPARTING DELAWARE WAVE OF LOW
PRESSURE.
DENSE FOG ADVY CONTINUES THROUGH 05Z IN LIGHT WIND FIELD WITH SFC
TD PROBABLY WARMER THAN THE SST WHICH IS STILL MID 50S. ONCE THE
WIND INCREASES...THE DENSE FOG DISSIPATES/LIFTS EARLY SATURDAY.
OUTLOOK...
SATURDAY NIGHT...A FRONTAL BOUNDARY LIFTS NORTH. SCA CONDITIONS
LIKELY WITH SEAS NEAR 5 FEET.
SUNDAY-MONDAY...SMALL CRAFT ADVISORY LEVEL WIND AND SEAS POSSIBLE
LIKELY ACROSS THE WATERS AHEAD OF AND BEHIND A COLD FRONT.
MONDAY NIGHT-TUESDAY...GALE FORCE WINDS POSSIBLE AS A WARM FRONT
AND LOW PRESSURE SYSTEM MOVE THROUGH THE REGION.
WEDNESDAY...WINDS AND SEAS SUBSIDE TO BELOW SCA CRITERIA.
&&
.CLIMATE...
WE ARE MONITORING THE POTENTIAL FOR ANY SMALL AMOUNTS OF SNOW FOR
MONDAY NIGHT AND TUESDAY TO SEE HOW MUCH MIGHT OCCUR AND MAY POST
MORE INFO ON LATE ARRIVING SNOWFALL FOR NJ. NOT CLOSE TO A RECORD
BUT DEPENDING ON WHAT OCCURS OR DOES NOT, MONDAY NIGHT/TUESDAY, WE
MIGHT START LOOKING AT SOMETHING WORTHY OF NOTE. GIVE US ANOTHER
DAY TO ASSESS AND WE`LL GO FROM THERE ON A POST.
NOW PROJECTING FOR THE REST OF THE MONTH FOR PHL FROM OUR 330 AM
FCST...50.8 OR 13.3 DEGREES ABOVE NORMAL (30 YEAR NORMAL IS 37.5)
AND 6.3 DEGREES ABOVE THE PREVIOUS WARMEST DECEMBER 1923. THIS
AVERAGE TEMPERATURE IS HIGHER THAN ANY OF THE NORMAL DAILY HIGHS
FOR THE MONTH OF DECEMBER.
BY THE WAY...THE RECORD 6 DEGREE DEPARTURE FOR DECEMBER IS ALSO A
RECORD DEPARTURE FROM ANY SECOND RANKING WARMEST OR COLDEST MONTH
IN PHILADELPHIA SINCE RECORDS BEGAN IN 1874. A TRULY ASTOUNDING
MONTH. THE SECOND LARGEST DEPARTURE WAS THE JANUARY 1977 RECORD
COLD AVG OF 20.0 DEGREES WHICH WAS 4.1F COLDER THAN THE PREVIOUS
COLDEST JANUARY. THE POINT IS...THIS DECEMBER WARMTH IN OUR AREA
IS EXTREME. SUMMER DEPARTURES FROM RECORD ARE NECESSARILY LESS SINCE
POLAR ORIGIN AIRMASSES IN THE LONG SUNLIT DAYS OF SUMMER ARE RARE
HERE.
DAILY AVERAGE TEMPERATURES IN PHL HAVE BEEN AT OR ABOVE NORMAL
SINCE NOVEMBER 24.
BOTH TODAY AND SUNDAY LOOK TO BE VERY WARM ONCE AGAIN. THE FOLLOWING
TABLE LISTS THE DAILY RECORD HIGHS FOR DECEMBER 25TH AND 27TH FOR
OUR EIGHT PRIMARY CLIMATE SITES.
SITES DECEMBER 25 DECEMBER 27
----- ----------- -----------
ACY 70 1982 67 1973
PHL 68 1964 64 1949
ILG 70 1982 65 1973
ABE 65 1964 59 1949
TTN 69 1889 63 1949
GED 71 1964 69 1973
RDG 68 1964 65 1936
MPO 60 1965 56 1964
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...DENSE FOG ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ430-431-
450>453.
SMALL CRAFT ADVISORY FROM 2 AM TO 11 PM EST SATURDAY FOR
ANZ450>455.
SMALL CRAFT ADVISORY FROM 4 AM TO NOON EST SATURDAY FOR ANZ430.
SMALL CRAFT ADVISORY FROM 4 AM TO 6 PM EST SATURDAY FOR ANZ431.
&&
$$
SYNOPSIS...SZATKOWSKI
NEAR TERM...MIKETTA
SHORT TERM...DRAG
LONG TERM...SZATKOWSKI
AVIATION...DRAG/SZATKOWSKI/MIKETTA
MARINE...DRAG/SZATKOWSKI
CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
620 PM EST FRI DEC 25 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL BE NEARLY STATIONARY ACROSS DELMARVA AND
SOUTHERN NEW JERSEY TONIGHT AS A WEAK AREA OF LOW PRESSURE PASSES
OFF THE DELAWARE COAST. THE FRONTAL BOUNDARY WILL THEN PUSH
FURTHER SOUTH AS SIGNIFICANTLY COOLER HIGH PRESSURE SLIDES TO OUR
NORTH ON SATURDAY. LOW PRESSURE MOVING FROM THE OHIO VALLEY
SATURDAY NIGHT TO NEW ENGLAND SUNDAY WILL PULL THE FRONT NORTH AS
A STRONG WARM FRONT SUNDAY, BEFORE THE TRAILING COLD FRONT SLIDES
SOUTH ACROSS THE AREA SUNDAY NIGHT. STRONG AND COLD HIGH PRESSURE
BRIEFLY BUILDS TO OUR NORTH LATE MONDAY INTO EARLY TUESDAY, BEFORE
A SERIES OF LOW PRESSURE SYSTEMS AND FRONTAL BOUNDARIES AFFECT THE
AREA DURING THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A LINE OF HEAVIER RAIN SHOWERS...WITH A FEW WIDELY-SCATTERED
THUNDERSTORMS...IS DRAPED OVER THE NORTHERN DELMARVA AND FURTHER
EAST THROUGH SOUTHERN NEW JERSEY. IT APPEARS SOME OF THE HEAVIEST
RAIN SHOWERS ARE DIMINISHING IN INTENSITY BASED ON THE LATEST 88-D
SIGNATURES. THE HRRR CONTINUES TO INDICATE A REDUCTION OF SHOWER
ACTIVITY AFTER 00Z, AND THAT TREND IS REFLECTED IN THE CURRENT
GFE WEATHER GRIDS. WINDS ARE GENERALLY UNDER 5 MPH IN MOST
LOCATIONS, AND PATCHY FOG IS FORMING IN SOME PLACES. PREVIOUS FCST
IS ON TRACK AND ONLY MINOR TWEAKS WERE MADE WITH THIS 630 PM
UPDATE THAT INCLUDED AN INCREASE IN POPS OVER SOUTHEASTERN PA AND
ADJANCENT SECTIONS OF NJ...AS WELL AS MINOR ADJUSTMENTS TO WIND
DIRECTION IN SOME SPOTS.
...PREV NEAR TERM DISCUSSION BELOW...
FGEN WITH THE FRONTAL BOUNDARY AND PWAT OF 1.5" PLUS CONVECTIVE
INSTABILITY IS YIELDING A PERIOD OF HEAVY SHOWERS AND ISOLATED
TSTMS THROUGH ABOUT 02Z FOR THE DELMARVA INTO S NJ AND FAR SE PA.
THIS WHIPS OFF TO THE EAST QUICKLY THIS EVENING AND I PROBABLY
DIDNT END IT SOON ENOUGH. THEN WE AWAIT AN INFLUX OF MUCH COOLER
AIR FROM THE NE AS A WAVE LOW PRESSURE GENERATING THIS EVENINGS
RAIN MOVES EWD OUT TO SEA AND A 1035MB HIGH SLIDES INTO SE CANADA
BY MORNING.
WPC QPF FROM 2512 USED.
PATCHY OR AREAS OF FOG BUT PROBABLY NOT AS DENSE AS THAT OF THIS
MORNING.
USED THE SIGNIFICANTLY COOLER NAM BL TEMPS FOR THE LATE NIGHT TEMP
SLIDE AND OTRW 50 50 BLENDED 12Z/25 GFS/NAM FOR THE ELEMENTS EXCEPT
MATCHLAV FOR MILDER TT/TD THIS EVENING.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
MUCH MUCH COOLER AS BOUNDARY LAYER TEMPS DOWN ABOUT 10C FROM FRIDAY
(20F COOLER AT 18Z FROM THE PHILLY AREA TO KACY SOUTHWARD)! THE
FRONT WILL BE SETTLED JUST TO OUR SOUTH. MOISTURE WILL BE OVERRIDING
THE BOUNDARY TO OUR SOUTH, (WEAK INSTABILITY BURST) AND AS A SHORT
WAVE/VORTICITY IMPULSES LIFTS NORTHWARD ACROSS THE AREA, RAINFALL
WILL LIKELY AGAIN BEGIN SPREADING ACROSS THE AREA.
CALLED IT RAIN WITH A CHANCE OF DRIZZLE. TEMPS MAY REMAIN IN THE
45 TO 50F RANGE ALL DAY PHL NORTH. ECMWF AND GFS ARE WARMER BUT I
DONT THINK THOSE MODELS ARE HANDLING THE UNDERUNNING VERY WELL.
THIS COULD BE A DEFICIENCY IN MY FCST APPROACH. RIGHT NOW... MAX
TEMPS AT PHL WILL BE AT MIDNIGHT (12 AM SATURDAY) AND A DAMP DANK
GUSTY NE WIND TYPE OF DAY EXPECTED SATURDAY I-95 EWD...A LITTLE
LESS WIND TO THE WEST OF I-95.
SO OTHER THAN RELYING MORE HEAVILY ON THE NAM FOR SATURDAYS TEMPS,
USED A 50 50 BLEND OF THE 12Z/25 GFS/NAM MOS GUIDANCE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
AN EXTENDED PERIOD OF UNSETTLED WEATHER WITH ANOTHER ROUND OF
RECORD HEAT ON SUNDAY THEN FOLLOWED WITH POSSIBLE WINTRY
PRECIPITATION LATER IN THE WEEK.
SATURDAY NIGHT, THE FRONTAL BOUNDARY WILL BE LIFTING NORTHWARD AS
A WARM FRONT AS AN AREA OF LOW PRESSURE MOVES OUT OF THE GREAT
LAKES REGION. PRECIPITATION WILL SPREAD NORTHWARD ACROSS THE
REGION BUT OVERALL RAINFALL AMOUNTS ARE EXPECTED TO BE RELATIVELY
LIGHT.
ON SUNDAY, WARMER AIR AGAIN SURGES ACROSS THE REGION IN THE WAKE
OF THE WARM FRONT AND MOST LOCATIONS WILL AGAIN SEE RECORD HIGH
TEMPERATURES. SOME LOCATIONS WILL LIKELY BREAK THE PREVIOUS
RECORD BY 3+ DEGREES. THERE WILL BE A CHANCE OF SHOWERS ON SUNDAY
AS WELL AS INTO SUNDAY NIGHT AS COLDER AIR THEN SURGES BACK INTO
THE REGION
ON MONDAY, HIGH PRESSURE BUILDS INTO THE REGION WITH SIGNIFICANTLY
COLDER AIR AND SETTING UP THE POTENTIAL FOR SOME WINTRY WEATHER.
THE NEXT STORM SYSTEM AFFECTS OUR REGION MONDAY NIGHT INTO
TUESDAY. BOTH THE OPERATIONAL GFS AND THE ENSEMBLE GUIDANCE HAVE
TRENDED WARMER OVER THE PAST SEVERAL MODEL CYCLES, SO WINTRY
PRECIPITATION HAS BEEN CONFINED FURTHER NORTH, MAINLY INTO THE
POCONOS AND PORTIONS OF THE LEHIGH VALLEY AND EXTREME NORTHERN NEW
JERSEY. THE POTENTIAL FOR SNOW WITH THIS SYSTEM HAS LESSENED, WITH
SLEET AND FREEZING RAIN BEING THE MAIN WINTER PRECIPITATION TYPES.
ANOTHER AREA OF HIGH PRESSURE THEN BUILDS INTO THE REGION ON
WEDNESDAY WITH TEMPERATURES MORE TYPICAL OF THIS TIME OF YEAR.
THERE IS THE POTENTIAL FOR ANOTHER STORM TO AFFECT THE REGION AS
WE APPROACH THE NEW YEAR. MAINLY RAIN IS MENTIONED IN THE FORECAST
AT THIS POINT, BUT ADDITIONAL WINTRY PRECIPITATION MAY BE
POSSIBLE, ONCE THE STORM TRACK FURTHER RESOLVES ITSELF.
&&
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
REST OF THIS AFTERNOON THROUGH 05Z THIS EVENING...VFR NORTH AND
DETERIORATING VFR CIGS SOUTH TO MVFR AND IFR CONDS CONDS IN HEAVY
SHOWERS AND ISOLATED TSTMS.
LIGHT, MAINLY NORTH WIND.
THEN LATE TONIGHT AFTER 05Z/26...IFR OR MVFR CONDITIONS IMPROVING TO
VFR OR MVFR CIGS EVERYWHERE WITH A GUSTY NORTHEAST WIND OF 15 TO 25
KT (EXCEPT GUSTS PROBABLY UNDER 20 KT VCNTY KRDG) BY 10Z SATURDAY.
SATURDAY...VFR CIGS AND A PROBABLE PERIOD OF MVFR CONDS
IN BANDS/PERIODS RAIN OR DRIZZLE. NORTHEAST WIND GUST 15-25 KT.
OUTLOOK...
SATURDAY NIGHT...PERIODS OF RAIN WITH LOW CIGS AND VSBYS.
SUNDAY-SUNDAY NIGHT...CHANCE OF SHOWERS. IMPROVING CIGS AND VSBYS.
MONDAY...VFR CONDITIONS AND GUSTY WINDS EARLY IN THE DAY. LOWERING
CONDITIONS LATER IN THE DAY WITH INCREASING CHANCE OF
PRECIPITATION.
MONDAY NIGHT-TUESDAY...LOW CIGS AND VSBYS WITH PRECIPITATION
SPREADING NORTHWARD ACROSS THE AREA. WINTRY PRECIPITATION
POSSIBLE, MAINLY FOR NORTHEAST PENNSYLVANIA AND NORTHERN NEW
JERSEY. GUSTY WINDS LIKELY.
WEDNESDAY...VFR CONDITIONS.
&&
.MARINE...
SCA FOR WIND AND OR SEAS ISSUED LATE TONIGHT INTO SATURDAY EVENING.
MWW HAS THE DETAILS BEHIND THE DEPARTING DELAWARE WAVE OF LOW
PRESSURE.
DENSE FOG ADVY EXTENDED THROUGH 05Z IN LIGHT WIND FIELD WITH SFC TD
PROBABLY WARMER THAN THE SST WHICH IS STILL MID 50S. ONCE THE
WIND INCREASES...THE DENSE FOG DISSIPATES/LIFTS EARLY SATURDAY.
OUTLOOK...
SATURDAY NIGHT...A FRONTAL BOUNDARY LIFTS NORTH. SCA CONDITIONS
LIKELY WITH SEAS NEAR 5 FEET.
SUNDAY-MONDAY...SMALL CRAFT ADVISORY LEVEL WIND AND SEAS POSSIBLE
LIKELY ACROSS THE WATERS AHEAD OF AND BEHIND A COLD FRONT.
MONDAY NIGHT-TUESDAY...GALE FORCE WINDS POSSIBLE AS A WARM FRONT
AND LOW PRESSURE SYSTEM MOVE THROUGH THE REGION.
WEDNESDAY...WINDS AND SEAS SUBSIDE TO BELOW SCA CRITERIA.
&&
.CLIMATE...
WE ARE MONITORING THE POTENTIAL FOR ANY SMALL AMOUNTS OF SNOW FOR
MONDAY NIGHT AND TUESDAY TO SEE HOW MUCH MIGHT OCCUR AND MAY POST
MORE INFO ON LATE ARRIVING SNOWFALL FOR NJ. NOT CLOSE TO A RECORD
BUT DEPENDING ON WHAT OCCURS OR DOES NOT, MONDAY NIGHT/TUESDAY, WE
MIGHT START LOOKING AT SOMETHING WORTHY OF NOTE. GIVE US ANOTHER
DAY TO ASSESS AND WE`LL GO FROM THERE ON A POST.
NOW PROJECTING FOR THE REST OF THE MONTH FOR PHL FROM OUR 330 AM
FCST...50.8 OR 13.3 DEGREES ABOVE NORMAL (30 YEAR NORMAL IS 37.5)
AND 6.3 DEGREES ABOVE THE PREVIOUS WARMEST DECEMBER 1923. THIS
AVERAGE TEMPERATURE IS HIGHER THAN ANY OF THE NORMAL DAILY HIGHS
FOR THE MONTH OF DECEMBER.
BY THE WAY...THE RECORD 6 DEGREE DEPARTURE FOR DECEMBER IS ALSO A
RECORD DEPARTURE FROM ANY SECOND RANKING WARMEST OR COLDEST MONTH
IN PHILADELPHIA SINCE RECORDS BEGAN IN 1874. A TRULY ASTOUNDING
MONTH. THE SECOND LARGEST DEPARTURE WAS THE JANUARY 1977 RECORD
COLD AVG OF 20.0 DEGREES WHICH WAS 4.1F COLDER THAN THE PREVIOUS
COLDEST JANUARY. THE POINT IS...THIS DECEMBER WARMTH IN OUR AREA
IS EXTREME. SUMMER DEPARTURES FROM RECORD ARE NECESSARILY LESS SINCE
POLAR ORIGIN AIRMASSES IN THE LONG SUNLIT DAYS OF SUMMER ARE RARE
HERE.
DAILY AVERAGE TEMPERATURES IN PHL HAVE BEEN AT OR ABOVE NORMAL
SINCE NOVEMBER 24.
BOTH TODAY AND SUNDAY LOOK TO BE VERY WARM ONCE AGAIN. THE FOLLOWING
TABLE LISTS THE DAILY RECORD HIGHS FOR DECEMBER 25TH AND 27TH FOR
OUR EIGHT PRIMARY CLIMATE SITES.
SITES DECEMBER 25 DECEMBER 27
----- ----------- -----------
ACY 70 1982 67 1973
PHL 68 1964 64 1949
ILG 70 1982 65 1973
ABE 65 1964 59 1949
TTN 69 1889 63 1949
GED 71 1964 69 1973
RDG 68 1964 65 1936
MPO 60 1965 56 1964
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...DENSE FOG ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ430-431-
450>453.
SMALL CRAFT ADVISORY FROM 2 AM TO 11 PM EST SATURDAY FOR
ANZ450>455.
SMALL CRAFT ADVISORY FROM 4 AM TO NOON EST SATURDAY FOR ANZ430.
SMALL CRAFT ADVISORY FROM 4 AM TO 6 PM EST SATURDAY FOR ANZ431.
&&
$$
SYNOPSIS...SZATKOWSKI
NEAR TERM...MIKETTA
SHORT TERM...DRAG
LONG TERM...SZATKOWSKI
AVIATION...DRAG/SZATKOWSKI/MIKETTA
MARINE...DRAG/SZATKOWSKI
CLIMATE...
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1008 PM EST FRI DEC 25 2015
.SYNOPSIS...
HIGH PRESSURE RIDGING INTO THE FORECAST AREA FROM THE ATLANTIC
WILL MAINTAIN UNSEASONABLE WARM WEATHER IN THE FORECAST AREA
THROUGH THE WEEKEND. AN APPROACHING COLD FRONT WILL MOVE INTO THE
FORECAST AREA MONDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
BROKEN LINE OF SHOWERS MOVING THROUGH THE WESTERN/NORTH MIDLANDS/CSRA
WEAKENING. LATEST HRRR SUGGESTS CONVECTION WILL DISSIPATE IN THE
CENTRAL MIDLANDS DURING THE NEXT COUPLE OF HOURS.
THE PRESSURE RIDGE IN THE ATLANTIC WILL CIRCULATE WARM AIR INTO
THE FORECAST AREA THROUGH TONIGHT. DEEP MOISTURE ASSOCIATED WITH A
FRONT WILL REMAIN NORTH OF THE AREA. SHALLOW LOW-LEVEL MOISTURE
WILL REMAIN HERE. THE MOISTURE COMBINED WITH NOCTURNAL COOLING
SHOULD RESULT IN WIDESPREAD FOG DEVELOPMENT TONIGHT. A DENSE FOG
ADVISORY MAY BE NEEDED. THE GUIDANCE TEMPERATURES WERE CONSISTENT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
THE PRESSURE RIDGE IN THE ATLANTIC WILL CONTINUE TO DIRECT WARM
AIR INTO THE FORECAST AREA. THE WARM ADVECTION PATTERN MAY HELP
SUPPORT SHOWERS BUT EXPECT LITTLE COVERAGE. THE MODELS KEEP DEEP
MOISTURE ASSOCIATED WITH A FRONT NORTH OF THE FORECAST AREA. THE
NAM AND GFS MOS INDICATE POPS LESS THAN 20 PERCENT THROUGH
SATURDAY NIGHT...AND 20 TO 30 PERCENT SUNDAY. HIGH LOW-LEVEL
MOISTURE AND NOCTURNAL COOLING WILL LIKELY RESULT IN WIDESPREAD
FOG DURING THE EARLY MORNING HOURS. USED THE GUIDANCE CONSENSUS
FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
THE GFS AND ECMWF DISPLAY AN APPROACHING COLD FRONT MONDAY MOVING
INTO THE FORECAST AREA MONDAY NIGHT. THE MODELS SHOW THE FRONT
STALLING NEAR THE AREA WITH ANOTHER COLD FRONT MOVING INTO THE
AREA TOWARD THE END OF THE PERIOD. THE GFS AND ECMWF MOS HAVE
POPS OF 30 TO 60 PERCENT. THE MOS KEEPS TEMPERATURES ABOVE NORMAL
THROUGH THE PERIOD.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
RESTRICTIONS EXPECTED TO CONTINUE THROUGH MUCH OF THE TAF PERIOD.
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS CONTINUE TO PUSH TOWARD
THE FORECAST AREA FROM THE WEST THIS EVENING. SHOWERS MAY REACH
THE TAF SITES LATER...BUT CHANCES ARE TOO LOW TO INCLUDE AT THIS
TIME AND ANY SHOWERS MAY BE LIGHT ENOUGH NOT TO RESULT IN
RESTRICTIONS. OTHERWISE...EXPECT VFR CONDITIONS TO CONTINUE
THROUGH TONIGHT UNTIL ANOTHER ROUND OF FOG AND STRATUS DEVELOPS
OVER THE AREA. HAVE INCLUDED LIFR CONDITIONS FOR ALL SITES FROM
THE EARLY MORNING HOURS THROUGH LATE MORNING AGAIN. EXPECT A
RETURN TO VFR DURING THE EARLY AFTERNOON HOURS. WINDS THROUGH THE
PERIOD WILL BE SOUTHERLY AT 7 KNOTS OR LESS.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE MAINLY IN LATE
NIGHT AND MORNING FOG AND STRATUS THROUGH MONDAY. LOW CONFIDENCE
IN RESTRICTIONS MONDAY AFTERNOON THROUGH WEDNESDAY AS A SERIES OF
FRONTAL SYSTEMS MOVE THROUGH THE TAF SITES.
&&
.HYDROLOGY...
RIVER FLOOD WARNINGS HAVE BEEN POSTED FOR MOST OF OUR FORECAST
POINTS. STILL MONITORING THE N. FORK OF THE EDISTO AT ORANGEBURG.
THE SAVANNAH RIVER AT BUTLER CREEK IS ALSO QUITE HIGH BUT REMAINS
BELOW ADVISORY CRITERIA. THE HIGH WATER ALONG THE SAVANNAH RIVER
BELOW AUGUSTA WILL PRODUCE SOME FLOODING OF LOW LYING AREAS.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS FOR THE DATES...
COLUMBIA METRO AIRPORT (CAE)
DEC 25...79 SET IN 1955
DEC 26...77 SET IN 1964
DEC 27...77 SET IN 1971
AUGUSTA BUSH FIELD (AGS)
DEC 25...79 SET IN 1984
DEC 26...80 SET IN 1964
DEC 27...76 SET IN 1971
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
640 PM EST FRI DEC 25 2015
.SYNOPSIS...
HIGH PRESSURE RIDGING INTO THE FORECAST AREA FROM THE ATLANTIC
WILL MAINTAIN UNSEASONABLE WARM WEATHER IN THE FORECAST AREA
THROUGH THE WEEKEND. AN APPROACHING COLD FRONT WILL MOVE INTO THE
FORECAST AREA MONDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A LINE OF SHOWERS HAS DEVELOPED IN THE SOUTH CAROLINA PIEDMONT AND
WAS PROPAGATING TO THE EAST/NORTHEAST THIS AFTERNOON. AIR MASS IN
THE NORTHERN MIDLANDS IS WEAKLY UNSTABLE. LATEST HRRR MODEL
SUGGESTS CONVECTION MAY MOVE INTO THE MIDLANDS. RAISED POPS NORTH
AND WEST OF CAE. ALTHOUGH NO LIGHTNING AT THE
MOMENT...THUNDERSTORMS POSSIBLE THROUGH MID EVENING.
THE PRESSURE RIDGE IN THE ATLANTIC WILL CIRCULATE WARM AIR INTO
THE FORECAST AREA THROUGH TONIGHT. DEEP MOISTURE ASSOCIATED WITH A
FRONT WILL REMAIN NORTH OF THE AREA. SHALLOW LOW-LEVEL MOISTURE
WILL REMAIN HERE. THE MOISTURE COMBINED WITH NOCTURNAL COOLING
SHOULD RESULT IN WIDESPREAD FOG DEVELOPMENT TONIGHT. A DENSE FOG
ADVISORY MAY BE NEEDED. THE GUIDANCE TEMPERATURES WERE CONSISTENT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
THE PRESSURE RIDGE IN THE ATLANTIC WILL CONTINUE TO DIRECT WARM
AIR INTO THE FORECAST AREA. THE WARM ADVECTION PATTERN MAY HELP
SUPPORT SHOWERS BUT EXPECT LITTLE COVERAGE. THE MODELS KEEP DEEP
MOISTURE ASSOCIATED WITH A FRONT NORTH OF THE FORECAST AREA. THE
NAM AND GFS MOS INDICATE POPS LESS THAN 20 PERCENT THROUGH
SATURDAY NIGHT...AND 20 TO 30 PERCENT SUNDAY. HIGH LOW-LEVEL
MOISTURE AND NOCTURNAL COOLING WILL LIKELY RESULT IN WIDESPREAD
FOG DURING THE EARLY MORNING HOURS. USED THE GUIDANCE CONSENSUS
FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
THE GFS AND ECMWF DISPLAY AN APPROACHING COLD FRONT MONDAY MOVING
INTO THE FORECAST AREA MONDAY NIGHT. THE MODELS SHOW THE FRONT
STALLING NEAR THE AREA WITH ANOTHER COLD FRONT MOVING INTO THE
AREA TOWARD THE END OF THE PERIOD. THE GFS AND ECMWF MOS HAVE
POPS OF 30 TO 60 PERCENT. THE MOS KEEPS TEMPERATURES ABOVE NORMAL
THROUGH THE PERIOD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
RESTRICTIONS EXPECTED TO CONTINUE THROUGH MUCH OF THE TAF PERIOD.
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS CONTINUE TO PUSH TOWARD
THE FORECAST AREA FROM THE WEST THIS EVENING. SHOWERS MAY REACH
THE TAF SITES LATER...BUT CHANCES ARE TOO LOW TO INCLUDE AT THIS
TIME AND ANY SHOWERS MAY BE LIGHT ENOUGH NOT TO RESULT IN
RESTRICTIONS. OTHERWISE...EXPECT VFR CONDITIONS TO CONTINUE
THROUGH TONIGHT UNTIL ANOTHER ROUND OF FOG AND STRATUS DEVELOPS
OVER THE AREA. HAVE INCLUDED LIFR CONDITIONS FOR ALL SITES FROM
THE EARLY MORNING HOURS THROUGH LATE MORNING AGAIN. EXPECT A
RETURN TO VFR DURING THE EARLY AFTERNOON HOURS. WINDS THROUGH THE
PERIOD WILL BE SOUTHERLY AT 7 KNOTS OR LESS.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE MAINLY IN LATE
NIGHT AND MORNING FOG AND STRATUS THROUGH MONDAY. LOW CONFIDENCE
IN RESTRICTIONS MONDAY AFTERNOON THROUGH WEDNESDAY AS A SERIES OF
FRONTAL SYSTEMS MOVE THROUGH THE TAF SITES.
&&
.HYDROLOGY...
RIVER FLOOD WARNINGS HAVE BEEN POSTED FOR MOST OF OUR FORECAST
POINTS. STILL MONITORING THE N. FORK OF THE EDISTO AT ORANGEBURG.
THE SAVANNAH RIVER AT BUTLER CREEK IS ALSO QUITE HIGH BUT REMAINS
BELOW ADVISORY CRITERIA. THE HIGH WATER ALONG THE SAVANNAH RIVER
BELOW AUGUSTA WILL PRODUCE SOME FLOODING OF LOW LYING AREAS.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS FOR THE DATES...
COLUMBIA METRO AIRPORT (CAE)
DEC 25...79 SET IN 1955
DEC 26...77 SET IN 1964
DEC 27...77 SET IN 1971
AUGUSTA BUSH FIELD (AGS)
DEC 25...79 SET IN 1984
DEC 26...80 SET IN 1964
DEC 27...76 SET IN 1971
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
124 AM EST THU DEC 24 2015
.PREV DISCUSSION... /ISSUED 852 PM EST WED DEC 23 2015/
..ISOLATED SEVERE STORMS OR TORNADOES POSSIBLE MAINLY AFTER
MIDNIGHT ALONG WITH CONTINUED FLOODING THREAT...
UPDATE...
MADE A FEW ADJUSTMENTS TO OVERNIGHT AND MORNING POP TREND THOUGH
STILL KEEP LIKELY TO CATEGORICAL GOING FOR NW MAJORITY OF CWA.
INCLUDED SEVERE MENTION AS A POSSIBILITY PRIMARILY AFTER MIDNIGHT
AS RAP INDICATING NOSE OF 500 J/KG SBCAPE MAY FINALLY MAKE A PUSH
NORTHEAST INTO THE AREA...WHICH IS ALREADY STRONGLY SHEARED
INCLUDING A ROBUST 50-60 KT 850MB JET AND A WHOPPING 500-700 M2S2
OF 0-1KM SRH. NEEDLESS TO SAY WOULD NOT TAKE MUCH TO HAVE A
GREATER SEVERE/TORNADO THREAT WITH ANY INCREASE IN INSTABILITY.
FLOODING THREAT CONTINUES ALSO...AND COULD BE A GREATER URBAN
FLOODING THREAT IF SOME OF THE LATEST WRF SOLUTIONS PAN OUT AS A
CONVECTIVE BAND STALLS FROM SW TO NE ACROSS NORTH GA WHICH COULD
INCLUDE METRO ATLANTA THURSDAY MORNING. WILL NEED TO KEEP A CLOSE
EYE ON SUBSEQUENT RUNS AND OTHER TRENDS SINCE THIS COULD
SIGNIFICANTLY RESULT IN LOCALLY HIGHER QPF VALUES. OTHERWISE MADE
JUST MINOR ADJUSTMENTS TO TEMPS/DEWPTS AND PREVIOUS DISCUSSION
FOLLOWS...
BAKER
PREV DISCUSSION... /ISSUED 732 PM EST WED DEC 23 2015/
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
FLOOD WATCH CONTINUES THROUGH FRIDAY EVENING...
MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM. LATEST RADAR
TRENDS SHOW SOUTHERN EDGE OF THE PRECIP SHIELD LIFTING NORTH. AT
THE SAME TIME TSTORMS ARE DEVELOPING ALONG THE SOUTHERN EDGE. WE
WILL SEE THE RISK OF THUNDER INCREASE ACROSS THE CWA AS THE REST
OF THIS AFTERNOON AND EVENING PROGRESSES. THERE IS A RISK OF
SEVERE STORMS AS SHEAR IS ALSO INCREASING AS WELL AS CAPE. THERE
WILL BE A LULL IN THE THUNDER LATE THIS EVENING...BUT AS THE COLD
FRONT APPROACHES THE TENNESSEE VALLEY...INSTABILITY WILL INCREASE
AGAIN ALONG WITH SHEAR AND WE WILL SEE ANOTHER ROUND OF THUNDER
WITH ANOTHER RISK OF SEVERE STORMS INCLUDING ISOLATED TORNADOES.
THE RISK WILL LIKELY CONTINUE INTO THURSDAY ACROSS NORTH GEORGIA
AS SHEAR REMAINS HIGH AND THE FRONT STALLS KEEPING HIGH CAPES
ACROSS NORTH GA. CENTRAL GA COULD SEE THUNDERSTORMS
THURSDAY...ALTHOUGH THE BETTER RISK WILL BE ACROSS NORTH GA. NEAR
RECORD/RECORD HIGH TEMPS WILL CONTINUE THROUGH THE SHORT TERM.
17
LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FLOOD WATCH CONTINUES THROUGH MID DAY FRIDAY WITH THE PRIMARY
FOCUS SHIFTING TO NORTH GA AT THE BEGINNING OF THE PERIOD BEFORE
THE FLOOD THREAT DIMINISHES BY THE WEEKEND.
AT THE START OF THE PERIOD...STRONG MID LEVEL RIDGING CENTERED
JUST SOUTH OF BERMUDA HELPING TO MAINTAIN THE PERSISTENT SOUTHWEST
FLOW ALOFT ACROSS THE SOUTHEASTERN STATES. THE REMNANT BOUNDARY
THAT PLAGUES US THROUGH EARLY FRIDAY LIFTS NORTH OF THE AREA
FRIDAY NIGHT LEAVING BEHIND THE WARM SOUPY AIRMASS INTO THE
WEEKEND...BUT NOT BEFORE DROPPING ANOTHER 1 TO 2 INCHES OF
PRECIPITATION ACROSS FAR NORTH GA. BOTH THE GFS AND ECMWF
GENERALLY AGREE THAT SOUTHERN TN AND OR NORTH GA WILL HAVE A
RESIDUAL THREAT FOR HEAVY RAIN EARLY FRIDAY THROUGH MIDDAY BEFORE
LIFTING NORTH OF THE REGION. GIVEN THE REMNANT MOISTURE IN PLACE
AS THE FRONT LIFTS NORTH...AM EXPECTING SOME AREAS OF FAIRLY DENSE
FOG TO FORM FRIDAY NIGHT INTO SATURDAY AM...SO SAFE TRAVELS HOME
FOR THOSE ON THE ROAD LATE CHRISTMAS DAY. WEEKEND LOOKS GENERALLY
WARM AND PARTLY TO MOSTLY CLOUDY. CANNOT RULE OUT A STRAY SHOWER
OR TSTORM BUT NOT EXPECTING MUCH IN THE WAY OF STORMS THROUGH THE
WEEKEND.
VERY STRONG JET MAX OF 150KTS DIVING SOUTH ON THE WEST COAST OF
THE US FRIDAY AFTERNOON WILL BE THE NEXT WEATHER MAKER FOR OUR
REGION BY EARLY NEXT WEEK. BY LATE SATURDAY BOTH THE ECMWF AND GFS
CLOSE OFF A PRETTY STRONG UPPER LOW OVER NEW MEXICO SETTING THE
STAGE FOR BOTH SEVERE WEATHER AND HEAVY SNOWS IN THE SOUTHERN
PLAINS AND SOUTHERN ROCKIES. BOTH THE GFS AND ECMWF GENERALLY
AGREE ON LIFTING THAT SYSTEM NORTHEAST ALONG A VERY SIMILAR TRACK TO
THE CURRENT SYSTEM ACROSS TX..AR..AND INTO THE OHIO VALLEY. THE
DIFFERENCE IS THAT THIS SYSTEM IS A TAD CLOSER TO OUR AREA AND MAY
POSE MORE OF A SEVERE THREAT BY LATE MONDAY INTO EARLY TUESDAY.
HAVE INCLUDED LIKELY POPS DURING THAT PERIOD GIVEN THE RELATIVE
AGREEMENT BETWEEN THE LONG RANGE MODELS AND CONFIDENCE THAT WE
WILL HAVE BOTH INSTABILITY AND SHEAR ACROSS THE AREA. WILL
CERTAINLY HAVE TO WATCH THAT SYSTEM AS IT COMES CLOSER.
WITH THE UPPER SYSTEM LIFTING NORTHEAST...WE ONLY GET A MODEST
COOL DOWN IN DAYS 6 AND 7. IT ISNT UNTIL MID TO LATE WEEK WHEN
ANOTHER DISTURBANCE ROLLS THROUGH THAT HAS MUCH MORE SEASONABLE
IE WINTER...AIRMASS ASSOCIATED WITH IT.
30
CLIMATE...
RECORDS FOR 12-23
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 73 1933 25 1989 61 1970 13 1989
1931
KATL 73 1990 22 1989 62 1879 8 1989
KMCN 82 1970 28 1989 62 1990 15 1989
KCSG 77 1990 26 1989 63 1970 14 1989
1970
RECORDS FOR 12-24
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 77 1964 31 1945 60 1964 7 1983
KATL 72 1984 28 1963 60 1879 3 1983
1964
KMCN 77 1964 35 1993 62 1964 10 1989
1983
KCSG 79 1984 35 1989 60 1988 9 1989
1964
1955
RECORDS FOR 12-25
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 77 1982 22 1983 61 1982 3 1983
1955
KATL 72 1987 17 1983 59 1982 0 1983
1889
KMCN 78 1982 25 1983 61 1982 7 1983
1932
KCSG 76 1982 24 1983 60 1982 8 1983
1964
RECORDS FOR 12-26
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 74 1964 30 1980 61 1987 9 1983
1928
KATL 72 1987 26 1935 61 1987 5 1983
KMCN 77 1987 33 1902 61 1987 9 1983
1982 1964
KCSG 80 1987 33 1983 64 1987 10 1983
RECORDS FOR 12-27
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 73 1971 33 1917 56 1982 11 1935
KATL 71 1982 27 1892 58 1982 12 1925
1889
KMCN 78 1987 35 1902 61 1987 17 1902
KCSG 75 2008 43 1948 61 1987 23 1985
1982
RECORDS FOR 12-28
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 78 1928 32 1950 59 1982 8 1925
KATL 74 1984 15 1894 58 1954 5 1925
1971
KMCN 76 2008 31 1925 65 1942 11 1925
2007
KCSG 80 1984 36 1950 59 2008 23 2010
1954 1977
&&
.AVIATION...
06Z UPDATE...
SHOWERS CONTINUING THROUGH THE PERIOD WITH MOSTLY IFR CEILINGS.
THERE WILL BE SOME ISOLATED THUNDERSTORMS THIS MORNING BUT SHOULD
BE MOSTLY SHOWERS THROUGH THE TAF PERIOD. WINDS WILL BE MAINLY OUT
OF THE S BUT WILL SEE PERIODS OF SW AND SE WINDS THROUGH THE
PERIOD. WIND SPEEDS WILL STAY MAINLY 10KT OR LESS BUT WILL SEE
SOME GUST TO NEAR 18KT IN AND AROUND ANY STRONGER STORMS. VSBYS
SHOULD STAY IN THE VFR TO MVFR RANGE.
//ATL CONFIDENCE...06Z UPDATE...
CONFIDENCE MEDIUM TO HIGH ON ALL ELEMENTS
01
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 73 65 74 62 / 60 60 40 40
ATLANTA 73 65 74 64 / 70 70 40 30
BLAIRSVILLE 70 61 71 61 / 80 70 60 50
CARTERSVILLE 74 64 74 63 / 70 70 40 40
COLUMBUS 76 66 78 63 / 60 50 20 20
GAINESVILLE 71 64 72 63 / 70 70 40 40
MACON 76 65 78 61 / 40 30 10 20
ROME 74 63 75 62 / 80 70 40 50
PEACHTREE CITY 74 65 75 61 / 60 60 40 30
VIDALIA 81 66 81 63 / 20 20 5 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH FRIDAY EVENING FOR THE FOLLOWING ZONES:
BALDWIN...BANKS...BARROW...BARTOW...BIBB...BLECKLEY...BUTTS...
CARROLL...CATOOSA...CHATTAHOOCHEE...CHATTOOGA...CHEROKEE...
CLARKE...CLAYTON...COBB...COWETA...CRAWFORD...CRISP...DADE...
DAWSON...DEKALB...DODGE...DOOLY...DOUGLAS...EMANUEL...FANNIN...
FAYETTE...FLOYD...FORSYTH...GILMER...GLASCOCK...GORDON...
GREENE...GWINNETT...HALL...HANCOCK...HARALSON...HARRIS...HEARD...
HENRY...HOUSTON...JACKSON...JASPER...JEFFERSON...JOHNSON...
JONES...LAMAR...LAURENS...LUMPKIN...MACON...MADISON...MARION...
MERIWETHER...MONROE...MONTGOMERY...MORGAN...MURRAY...MUSCOGEE...
NEWTON...NORTH FULTON...OCONEE...OGLETHORPE...PAULDING...PEACH...
PICKENS...PIKE...POLK...PULASKI...PUTNAM...ROCKDALE...SCHLEY...
SOUTH FULTON...SPALDING...STEWART...SUMTER...TALBOT...
TALIAFERRO...TAYLOR...TELFAIR...TOOMBS...TOWNS...TREUTLEN...
TROUP...TWIGGS...UNION...UPSON...WALKER...WALTON...WARREN...
WASHINGTON...WEBSTER...WHEELER...WHITE...WHITFIELD...WILCOX...
WILKES...WILKINSON.
TORNADO WATCH UNTIL 5 AM EST EARLY THIS MORNING FOR THE
FOLLOWING ZONES: CATOOSA...DADE...WALKER.
&&
$$
SHORT TERM...01
LONG TERM....41
AVIATION...01
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
854 PM CST FRI DEC 25 2015
.UPDATE...
ISSUED AT 845 PM CST FRI DEC 25 2015
Surface high pressure located well north of our area will shift
slowly east overnight while high and mid level clouds increase
from the southwest ahead of our next weather system. Thunderstorms
that were occurring today along a stalled frontal boundary over
the southern Mississippi Valley have kept that boundary further
south than indicated by models yesterday at this time. Just what
affect, if any, that will have on the placement of the front
in southeast Illinois tomorrow remains to be seen, and that will
be the key to where the heavy rainfall sets up as a plume of deep
subtropical moisture, seen on our evening water vapor loop, streams
northeast into the region on Saturday into Saturday night. The 00z
ILX sounding showing quite a bit of dry air in place in the low
and mid levels of the atmosphere. The latest RAP model suggests
any rain on Saturday will hold off until dawn across southeast
Illinois, and over the remainder of our area by late morning.
Temperatures early this evening have dropped off quicker than
earlier thought so we had to make some adjustments to the overnight
lows. Based on the latest satellite trends, it appears with the
thicker cloud cover moving up from the southwest, we may have seen
our overnight lows reached in some areas already with a steady or
slowly rising trend late tonight. Should have the updated zones
out by 900 pm.
&&
.SHORT TERM...(Tonight)
ISSUED AT 333 PM CST FRI DEC 25 2015
Early afternoon surface map showing high pressure centered over
Wisconsin, providing a dry north/northeast flow into central
Illinois. Expansive area of stratus has extended southwest from the
high and did clip the far western CWA earlier this morning, but the
southern and eastern edges have eroded some. However, there has been
some diurnal type development a bit further to the south. Most of
the forecast area has had a fairly nice day, with temperatures
reaching the mid 40s to lower 50s with a good deal of sunshine. The
far northwest corner was still below 40 degrees early this afternoon
due to the more extensive clouds.
Main focus for tonight will be with the timing of precipitation.
There has been quite a bit of convection this afternoon from
Louisiana northeast into eastern Tennessee, which is slowing the
northward push of the frontal boundary. Most of the morning models
generally bring the front into the southern tip of Illinois by
morning, as the southwest upper flow begins to sharpen with an upper
low forms over Arizona. Have maintained the chance PoP`s across the
far southeast CWA, as forecast soundings near Lawrenceville show a
nice moistening of the lower layers between midnight and 3 am. Areas
further north do not see this happening until closer to morning, so
have kept the forecast dry from about Rushville-Mattoon northward.
Temperatures will be relatively steady through the night.
.LONG TERM...(Saturday through Friday)
ISSUED AT 333 PM CST FRI DEC 25 2015
Several weather concerns over the next few days for central IL:
First, A major rain event continues to set up for central/SE IL and
surrounding areas. Two periods of heaviest rainfall appear likely at
this point. First will start Saturday morning south of I-70, spread
northward through the early afternoon encompassing much of the I-72
corridor, and continue into Sunday morning. A lull Sunday afternoon-
evening...then re-intensification Sunday night through Monday
afternoon. A flash flood watch is in effect from Saturday at noon to
Monday evening for areas from Scott County through Springfield to
Champaign county and areas south/eastward.
Second, thunderstorms with some severe potential Saturday afternoon
through Saturday night...mainly southeast of a Springfield to
Champaign line.
Third, potential for freezing rain Sunday night/Monday
morning...mainly north of I-72.
Synopsis...A frontal boundary will start the day near or south of
the Ohio River Saturday morning...lifting northward rapidly through
the day as strong southwesterly flow sets up ahead of a deepening
upper low over the Southwestern states. A plume of near 1.5 inch
precipitable water (near record for this time of year) will be
interacting with the warm frontal zone creating a plume of heavy
rain through central IL. Rainfall amounts of 2 to 3 inches can be
expected Saturday afternoon through Sunday morning from around
Springfield to Champaign southward through Flora and Lawrenceville.
Enough instability is indicated by model solutions for thunderstorms
in this area as well, and there will be enough shear for a concern
of severe storms...however instability is somewhat on the weak side.
The next feature will be a vigorous low ejecting out of the
Southwestern states...providing widespread lift by Sunday night and
another round of heavy precipitation...this time another 2 inches
across central IL. All told...4 to 6 inches possible I-72
southward...with 2 to 4 inches to the north by Tuesday morning.
The low track has trended somewhat northwest of previous runs at
this point...which diminishes the freezing rain and snow threat
somewhat through central IL For Monday/Monday night. Latest trends
would suggest freezing rain will be limited more toward areas north
of I-72 than previous runs as cold air would be confined to areas
farther northwest.
Temps will edge above freezing everywhere toward midday Monday,
resulting in a change over to all rain. Once the low tracks into
the southern Great Lakes, enough cold air will be pulled down behind
it to support a change over to snow or a rain/snow mix north of I-70
Monday night. Will need to keep an eye on this, as any eastward
deviation of the low track will lead to more snow and possible
accumulations across the area.
A break in precipitation is expected Wednesday, then another system
could bring some light precipitation...mainly snow...back late
wednesday into Wednesday night.
Temperatures quite mild Saturday with highs ranging from 46 in
Galesburg to 64 in Lawrencevile...then following a cooling trend
through midweek. Eventually...Highs should be near or slightly below
normal with highs ranging from the upper 20s to upper 30s by
Thursday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
ISSUED AT 515 PM CST FRI DEC 25 2015
VFR conditions are expected until around 09z with MVFR cigs and
some rain arrives first at SPI and DEC and by 13z at CMI and BMI
as the next storm system approaches the area. Once the rain
commences, forecast soundings continue to suggest a quick
transition to IFR and even LIFR cigs with the steady rainfall.
Some elevated instabiliy along and especially south of I-72
will support VCTS at SPI and DEC late tomorrow afternoon and
evening. Surface winds tonight will be from the east at 10
to 15 kts and east to southeast on Saturday at similar speeds.
&&
.ILX Watches/Warnings/Advisories...
Flash Flood Watch from Saturday afternoon through Monday
afternoon for ILZ044>046-049>057-061>063-066>068-071>073.
&&
$$
UPDATE...Smith
SHORT TERM...Geelhart
LONG TERM...Onton
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
156 PM CST THU DEC 24 2015
.UPDATE...
1023 AM...MORNING UPDATE...SHORT TERM/HI RES GUIDANCE SUGGESTING
WAVE OVER MISSOURI MAY BE SUFFICIENT FOR SOME SPRINKLES OR BRIEF
LIGHT RAIN ACROSS SOUTH/CENTRAL PARTS OF THE CWA THIS AFTERNOON
AND ADDED SLIGHT CHANCE MENTION OF THIS AFTERNOON. CLOUD COVER
ALSO EXPECTED TO FILL BACK IN WITH THIS WAVE AND THAT MAY KEEP
TEMPS FROM RISING MUCH BEYOND UPPER 30S NORTH TO MID 40S SOUTH.
A SECOND WAVE BACK OVER WESTERN IOWA WILL BE LIFTING NORTHEAST
THIS AFTERNOON AND THIS EVENING. 12Z NAM AND GFS SHOW THE BULK OF
THE PRECIP WITH THIS WAVE LIFTING NORTH OF THE CWA THIS EVENING.
THIS TREND ALSO SEEMS SUPPORTED BY THE RAP THOUGH THE HRRR STILL
MAINTAINS PRECIP INTO THE MID/LATE EVENING...MAINLY ACROSS FAR
NORTHWEST IL. ANY PRECIP THAT DOES OCCUR IS LIKELY TO BE LIGHT
AND WITH TEMPS PROBABLY STILL AT OR ABOVE FREEZING AT THAT
TIME...DOUBTFUL THERE WOULD BE ANY SNOW ACCUMULATION. CMS
&&
.SHORT TERM...
249 AM CST
THROUGH TONIGHT...
WINDS HAVE BEGUN TO CALM DOWN AFTER SEEING GUSTS EARLY THIS MORNING
OVER 40 MPH...BUT WITH SFC RIDGING ARRIVING THE GRADIENT WILL
CONTINUE TO DECREASE THROUGHOUT THE MORNING. BY MIDDAY WINDS SHOULD
BE GENERALLY SOUTHWEST BETWEEN 10 TO 20 MPH. THE LOW THAT BROUGHT
THE SEVERE WEATHER TO THE REGION HAS ALREADY LIFTED TO NEAR JAMES
BAY IN ONTARIO. DESPITE THE QUIET CONDITIONS FOR THE BULK OF THE
DAY...THE LARGEST CHALLENGE WILL BE ON HOW THE STRATUS LAYER
EVOLVES. IR IMAGERY SHOWS A LARGE STRATUS DECK SLIDING SOUTHEAST
ACROSS NORTHERN IL STRETCHING NORTHWEST THROUGH IOWA/MINNESOTA. HI-
RES GUIDANCE CONTINUES TO FEED CLOUDS ACROSS THE NORTHERN HALF OF
THE CWFA...WHICH COULD RESULT IN TEMPS BEING COOLER THEN PRESENT
HIGHS PROGGED AROUND 40 IN THE NORTHWEST AND LOW/MID 40S FOR
CENTRAL/SOUTHERN CWFA. DEW POINTS WILL BE HOVERING IN THE UPR 20S
DUE TO THE LACK OF STRONG SUBSIDENCE.
FURTHER UPSTREAM ACROSS THE CENTRAL ROCKIES IS A STRONGER MID-LVL
VORT...IR IMAGERY IS DEPICTING THIS FEATURE WELL AND MOST
OPERATIONAL SOLUTIONS HAVE THE TRAJECTORY OF THE MID-LVL WAVE
SLIDING EAST/NORTHEAST ACROSS IOWA INTO SOUTHERN WISC BY THIS
EVENING. THE CONCERN IS THAT IF THE STRATUS LAYER REMAINS IN PLACE
ACROSS THE FORECAST AREA...THE MID-LVL WAVE MAY ACT AS A CATALYST
AND QUICKLY SATURATE FROM TOP/DOWN THE PROFILE. WHILE THERE IS A
SHALLOW WARM LAYER...IT IS CONCEIVABLE THAT THIS COULD ERODE QUICKLY
IF DEW POINTS REMAIN IN THE UPR 20S/NEAR 30. IF INDEED THE WAVE
AGITATES THE ENVIRONMENT AND PRODUCES PRECIP...IT WOULD LIKELY FALL
AS RAIN AT THE ONSET...THEN THERMAL COOL DOWN TO SUPPORT A RAIN/SNOW
MIX BEFORE GOING OVER TO LIGHT SNOW AROUND 2-4Z. HAVE OPTED TO BLEND
MORE WITH THE SREF/GFS IN TIMING...BRINGING PRECIP INTO NORTHWEST
CWFA MID/LATE AFTN AND SPREADING EAST TOWARDS THE CHICAGO METRO BY
00-02Z. QPF LOOKS VERY LOW...BUT COULD EASILY SEE WHAT SNOW FALLS TO
PERHAPS PRODUCE A FEW TENTHS OF AN INCH BEFORE ENDING. SFC CONDS
SHOULD BE WARM ENOUGH TO LIMIT ANY ACCUMULATIONS...BUT IF THE MID-
LVL WAVE IS ABLE TO EFFICIENTLY PRODUCE MOISTURE THEN QPF COULD BE
HIGHER AS WELL AS PERHAPS UP TO ONE HALF INCH OF SNOW.
TEMPS OVERNIGHT SHOULD COOL OFF INTO THE UPR 20S IN THE NORTH...BUT
REMAIN IN THE LOW TO PERHAPS MID 30S IN THE FAR SOUTH.
BEACHLER
&&
.LONG TERM...
249 AM CST
FRIDAY THROUGH WEDNESDAY...
CHRISTMAS DAY THROUGH SATURDAY... SFC RIDGING THEN ABSORBS THE
REMAINING LOW LEVEL MOISTURE EARLY CHRISTMAS DAY WITH DRY CONDS AND
P-CLOUDY SKIES EXPECTED FOR MUCH OF THE DAY. WITH THE LACK OF COLD
AIR IN PLACE...TEMPS WILL LIKELY REBOUND INTO THE MID/UPR 40S. ONE
CAVEAT IS THAT WINDS WILL BE TURNING NORTHEAST...WHICH COULD KEEP
THE AREAS ADJACENT TO LAKE MICHIGAN A FEW DEGREES COOLER. BY
CHRISTMAS NIGHT OPERATIONAL GUIDANCE CONTINUES TO PROG A DEVELOPING
SHORTWAVE ACROSS THE LEE-SIDE OF THE SOUTHERN ROCKIES. WITH THE
500MB TROUGH PARKED ACROSS THE FOUR-CORNERS REGION OF THE
CONUS...SOUTHERLY FLOW OF MOISTURE APPEARS POISED TO STREAM NORTH
FROM THE WESTERN GULF. SO TEMPS MAY ONLY FALL SLIGHTLY CHRISTMAS
NIGHT BEFORE WARMING OVERNIGHT. PRECIP SHOULD OVERSPREAD THE REGION
BY EARLY SATURDAY...AND BE WARM ENOUGH INITIALLY TO SUPPORT RAIN.
UNSEASONABLY WARM/MOIST CONDITIONS CONTINUE INTO SAT...WITH DEW
POINTS YET AGAIN PUSHING INTO THE LOW 50S IN THE FAR SOUTHERN CWFA.
GUIDANCE CONTINUES TO INDICATE SOME MID-LVL INSTABILITY WITH A
SERIES OF WEAK SHORTWAVES LIFTING NORTHEAST ALONG A QUASI-STATIONARY
BOUNDARY...SO HAVE HELD ONTO THE MENTION OF THUNDER IN THE SOUTH.
SUNDAY THROUGH WEDNESDAY... FOR THE SECOND HALF OF THE WEEKEND
OPERATIONAL GUIDANCE HAS BEEN BOUNCEING BETWEEN THE PLACEMENT OF THE
FRONTAL BOUNDARY...BUT NOW APPEARS FAVORABLE TO PUSH SOUTH OF THE
FORECAST AREA BY SUN MIDDAY WITH A STRONG CANADIAN SFC RIDGE
DROPPING SOUTH INTO THE NORTHERN PLAINS EARLY SUN...THEN STRETCHING
EAST SUN NGT TO COVER MUCH OF THE GREAT LAKES AND PUSH THE BOUNDARY
FURTHER SOUTH. ENSEMBLES CONTINUE TO SHOW THAT THE SFC RIDGE MAY BE
STRONG ENOUGH TO HOLD THE FRONTAL BOUNDARY FURTHER SOUTH INTO
MONDAY...WHICH MAY FURTHER DELAY MOISTURE FROM LIFTING BACK ACROSS
THE REGION UNTIL MON NGT/TUE.
MID-LVL FLOW DOES BEGIN TO TRANSITION TOWARDS A SEMI-ZONAL SETUP
MON...WHICH COULD AID IN EJECTING THE SFC RIDGE BACK EAST EARLIER
MON AND ALLOW THE BOUNDARY AND DEVELOPING SHORTWAVE TO QUICKLY LIFT
NORTH DURING THE DAY MON. IT IS POSSIBLE THAT THE NORTHERN EDGE OF
THE PRECIP SHIELD...ONCE IT DOES RETURN NORTH...COULD START AS A
WINTRY MIX BEFORE WARMING AND TRANSITIONING OVER TO ALL RAIN. BUT
GIVEN THE LOW CONFIDENCE IN THE PRECISE PLACEMENT OF THE
LOW/BOUNDARY...THIS PERIOD WILL LIKELY UNDERGO ADDITIONAL CHANGES.
TEMPS TOWARDS NEXT WEEK APPEAR TO LEAN TOWARDS CLIMO WITH HIGHS IN
THE LOW/MID 30S...BUT LOWS WILL LIKELY SEE SOME MODERATION GIVEN
EXPECTED CLOUD COVER AND REMAIN IN THE MID/UPR 20S TO AROUND 30.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SLIGHT CHANCE FOR LIGHT PCPN LATE THIS AFTERNOON OR EARLY THIS
EVENING.
KREIN
//DISCUSSION...UPDATED 18Z...
THE GUSTY WSWLY WINDS ARE DIMINISHING AS DEEP LOW PRESSURE
CONTINUES TO PULL AWAY TO THE NORTHEAST AND HIGH PRESSURE BUILDS
ACROSS THE MIDDLE MISSISSIPPI VALLEY AND THE OHIO VALLEY. THE WIND
SPEED TREND WILL CONTINUE DOWN...BECMG LGT/VRBL THIS EVENING AND
OVERNIGHT AS THE PRESSURE GRADIENT ACROSS THE REGION BECOMES VERY
WEAK.
A WEAK MID LEVEL IMPULSE TRACKING FROM IOWA THIS AFTERNOON AND
ACROSS THE AREA AROUND THE WISCONSIN-ILLINOIS BORDER HAS THE
POTENTIAL TO GENERATE SOME PCPN...BUT FORECAST MOISTURE PROFILES
INDICATE CONDITIONS BELOW 5KFT SHOULD BE RATHER DRY AND A
SATURATED LAYER WITH WEAK FORCING LOOKS TO RATHER SHALLOW.
SO...WHILE THERE IS A SLIGHT CHANCE FOR RAIN OR A RAIN/SNOW
MIX...CHANCES ARE TOO LOW TO INCLUDE IN THE TAFS...AND MAY
ULTIMATELY END UP BEING MORE VIRGA THAN ACTUAL PCPN REACHING THE
GROUND.
FOR TOMORROW...WITH THE CENTER OF HIGH PRESSURE OVER SRN WISCONSIN
AND A DRY AIRMASS ACROSS THE REGION...EXPECT ONLY OPERATIONALLY
INSIGNIFICANT CLOUD COVER AND LIGHT NELY WINDS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE THAT THE TERMINALS WILL REMAIN DRY THROUGH
THE PERIOD.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...SLIGHT CHANCE OF RAIN.
SATURDAY...RAIN SHOWERS LIKELY. CHANCE OF MVFR/IFR.
SUNDAY...VFR.
MONDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
TUESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
WEDNESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
RODRIGUEZ
&&
.MARINE...
350 AM CST
HIGH WINDS AND WAVES CONTINUING ACROSS THE ENTIRE LAKE THIS
MORNING. THE STRONGEST WINDS ARE CURRENTLY OCCURRING OVER THE
NORTH HALF WHERE STORM FORCE WINDS ARE STILL ONGOING. THESE STORM
FORCE WINDS WILL CONTINUE THROUGH MID MORNING...WITH GALES
PERSISTING THEN INTO THE AFTERNOON. GALES ARE STILL OCCURRING
ACROSS THE SOUTH HALF/NEARSHORE...AND WITH THESE SPEEDS EXPECTED
TO CONTINUE THROUGH MID MORNING AS WELL. SPEEDS WILL CONTINUE TO
DIMINISH OVER THE ENTIRE LAKE THIS AFTERNOON AND THIS
EVENING...WITH A PERIOD OF LIGHTER WINDS TO END THE WORK WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1121 AM CST THU DEC 24 2015
.UPDATE...
1023 AM...MORNING UPDATE...SHORT TERM/HI RES GUIDANCE SUGGESTING
WAVE OVER MISSOURI MAY BE SUFFICIENT FOR SOME SPRINKLES OR BRIEF
LIGHT RAIN ACROSS SOUTH/CENTRAL PARTS OF THE CWA THIS AFTERNOON
AND ADDED SLIGHT CHANCE MENTION OF THIS AFTERNOON. CLOUD COVER
ALSO EXPECTED TO FILL BACK IN WITH THIS WAVE AND THAT MAY KEEP
TEMPS FROM RISING MUCH BEYOND UPPER 30S NORTH TO MID 40S SOUTH.
A SECOND WAVE BACK OVER WESTERN IOWA WILL BE LIFTING NORTHEAST
THIS AFTERNOON AND THIS EVENING. 12Z NAM AND GFS SHOW THE BULK OF
THE PRECIP WITH THIS WAVE LIFTING NORTH OF THE CWA THIS EVENING.
THIS TREND ALSO SEEMS SUPPORTED BY THE RAP THOUGH THE HRRR STILL
MAINTAINS PRECIP INTO THE MID/LATE EVENING...MAINLY ACROSS FAR
NORTHWEST IL. ANY PRECIP THAT DOES OCCUR IS LIKELY TO BE LIGHT
AND WITH TEMPS PROBABLY STILL AT OR ABOVE FREEZING AT THAT
TIME...DOUBTFUL THERE WOULD BE ANY SNOW ACCUMULATION. CMS
&&
.SHORT TERM...
249 AM CST
THROUGH TONIGHT...
WINDS HAVE BEGUN TO CALM DOWN AFTER SEEING GUSTS EARLY THIS MORNING
OVER 40 MPH...BUT WITH SFC RIDGING ARRIVING THE GRADIENT WILL
CONTINUE TO DECREASE THROUGHOUT THE MORNING. BY MIDDAY WINDS SHOULD
BE GENERALLY SOUTHWEST BETWEEN 10 TO 20 MPH. THE LOW THAT BROUGHT
THE SEVERE WEATHER TO THE REGION HAS ALREADY LIFTED TO NEAR JAMES
BAY IN ONTARIO. DESPITE THE QUIET CONDITIONS FOR THE BULK OF THE
DAY...THE LARGEST CHALLENGE WILL BE ON HOW THE STRATUS LAYER
EVOLVES. IR IMAGERY SHOWS A LARGE STRATUS DECK SLIDING SOUTHEAST
ACROSS NORTHERN IL STRETCHING NORTHWEST THROUGH IOWA/MINNESOTA. HI-
RES GUIDANCE CONTINUES TO FEED CLOUDS ACROSS THE NORTHERN HALF OF
THE CWFA...WHICH COULD RESULT IN TEMPS BEING COOLER THEN PRESENT
HIGHS PROGGED AROUND 40 IN THE NORTHWEST AND LOW/MID 40S FOR
CENTRAL/SOUTHERN CWFA. DEW POINTS WILL BE HOVERING IN THE UPR 20S
DUE TO THE LACK OF STRONG SUBSIDENCE.
FURTHER UPSTREAM ACROSS THE CENTRAL ROCKIES IS A STRONGER MID-LVL
VORT...IR IMAGERY IS DEPICTING THIS FEATURE WELL AND MOST
OPERATIONAL SOLUTIONS HAVE THE TRAJECTORY OF THE MID-LVL WAVE
SLIDING EAST/NORTHEAST ACROSS IOWA INTO SOUTHERN WISC BY THIS
EVENING. THE CONCERN IS THAT IF THE STRATUS LAYER REMAINS IN PLACE
ACROSS THE FORECAST AREA...THE MID-LVL WAVE MAY ACT AS A CATALYST
AND QUICKLY SATURATE FROM TOP/DOWN THE PROFILE. WHILE THERE IS A
SHALLOW WARM LAYER...IT IS CONCEIVABLE THAT THIS COULD ERODE QUICKLY
IF DEW POINTS REMAIN IN THE UPR 20S/NEAR 30. IF INDEED THE WAVE
AGITATES THE ENVIRONMENT AND PRODUCES PRECIP...IT WOULD LIKELY FALL
AS RAIN AT THE ONSET...THEN THERMAL COOL DOWN TO SUPPORT A RAIN/SNOW
MIX BEFORE GOING OVER TO LIGHT SNOW AROUND 2-4Z. HAVE OPTED TO BLEND
MORE WITH THE SREF/GFS IN TIMING...BRINGING PRECIP INTO NORTHWEST
CWFA MID/LATE AFTN AND SPREADING EAST TOWARDS THE CHICAGO METRO BY
00-02Z. QPF LOOKS VERY LOW...BUT COULD EASILY SEE WHAT SNOW FALLS TO
PERHAPS PRODUCE A FEW TENTHS OF AN INCH BEFORE ENDING. SFC CONDS
SHOULD BE WARM ENOUGH TO LIMIT ANY ACCUMULATIONS...BUT IF THE MID-
LVL WAVE IS ABLE TO EFFICIENTLY PRODUCE MOISTURE THEN QPF COULD BE
HIGHER AS WELL AS PERHAPS UP TO ONE HALF INCH OF SNOW.
TEMPS OVERNIGHT SHOULD COOL OFF INTO THE UPR 20S IN THE NORTH...BUT
REMAIN IN THE LOW TO PERHAPS MID 30S IN THE FAR SOUTH.
BEACHLER
&&
.LONG TERM...
249 AM CST
FRIDAY THROUGH WEDNESDAY...
CHRISTMAS DAY THROUGH SATURDAY... SFC RIDGING THEN ABSORBS THE
REMAINING LOW LEVEL MOISTURE EARLY CHRISTMAS DAY WITH DRY CONDS AND
P-CLOUDY SKIES EXPECTED FOR MUCH OF THE DAY. WITH THE LACK OF COLD
AIR IN PLACE...TEMPS WILL LIKELY REBOUND INTO THE MID/UPR 40S. ONE
CAVEAT IS THAT WINDS WILL BE TURNING NORTHEAST...WHICH COULD KEEP
THE AREAS ADJACENT TO LAKE MICHIGAN A FEW DEGREES COOLER. BY
CHRISTMAS NIGHT OPERATIONAL GUIDANCE CONTINUES TO PROG A DEVELOPING
SHORTWAVE ACROSS THE LEE-SIDE OF THE SOUTHERN ROCKIES. WITH THE
500MB TROUGH PARKED ACROSS THE FOUR-CORNERS REGION OF THE
CONUS...SOUTHERLY FLOW OF MOISTURE APPEARS POISED TO STREAM NORTH
FROM THE WESTERN GULF. SO TEMPS MAY ONLY FALL SLIGHTLY CHRISTMAS
NIGHT BEFORE WARMING OVERNIGHT. PRECIP SHOULD OVERSPREAD THE REGION
BY EARLY SATURDAY...AND BE WARM ENOUGH INITIALLY TO SUPPORT RAIN.
UNSEASONABLY WARM/MOIST CONDITIONS CONTINUE INTO SAT...WITH DEW
POINTS YET AGAIN PUSHING INTO THE LOW 50S IN THE FAR SOUTHERN CWFA.
GUIDANCE CONTINUES TO INDICATE SOME MID-LVL INSTABILITY WITH A
SERIES OF WEAK SHORTWAVES LIFTING NORTHEAST ALONG A QUASI-STATIONARY
BOUNDARY...SO HAVE HELD ONTO THE MENTION OF THUNDER IN THE SOUTH.
SUNDAY THROUGH WEDNESDAY... FOR THE SECOND HALF OF THE WEEKEND
OPERATIONAL GUIDANCE HAS BEEN BOUNCEING BETWEEN THE PLACEMENT OF THE
FRONTAL BOUNDARY...BUT NOW APPEARS FAVORABLE TO PUSH SOUTH OF THE
FORECAST AREA BY SUN MIDDAY WITH A STRONG CANADIAN SFC RIDGE
DROPPING SOUTH INTO THE NORTHERN PLAINS EARLY SUN...THEN STRETCHING
EAST SUN NGT TO COVER MUCH OF THE GREAT LAKES AND PUSH THE BOUNDARY
FURTHER SOUTH. ENSEMBLES CONTINUE TO SHOW THAT THE SFC RIDGE MAY BE
STRONG ENOUGH TO HOLD THE FRONTAL BOUNDARY FURTHER SOUTH INTO
MONDAY...WHICH MAY FURTHER DELAY MOISTURE FROM LIFTING BACK ACROSS
THE REGION UNTIL MON NGT/TUE.
MID-LVL FLOW DOES BEGIN TO TRANSITION TOWARDS A SEMI-ZONAL SETUP
MON...WHICH COULD AID IN EJECTING THE SFC RIDGE BACK EAST EARLIER
MON AND ALLOW THE BOUNDARY AND DEVELOPING SHORTWAVE TO QUICKLY LIFT
NORTH DURING THE DAY MON. IT IS POSSIBLE THAT THE NORTHERN EDGE OF
THE PRECIP SHIELD...ONCE IT DOES RETURN NORTH...COULD START AS A
WINTRY MIX BEFORE WARMING AND TRANSITIONING OVER TO ALL RAIN. BUT
GIVEN THE LOW CONFIDENCE IN THE PRECISE PLACEMENT OF THE
LOW/BOUNDARY...THIS PERIOD WILL LIKELY UNDERGO ADDITIONAL CHANGES.
TEMPS TOWARDS NEXT WEEK APPEAR TO LEAN TOWARDS CLIMO WITH HIGHS IN
THE LOW/MID 30S...BUT LOWS WILL LIKELY SEE SOME MODERATION GIVEN
EXPECTED CLOUD COVER AND REMAIN IN THE MID/UPR 20S TO AROUND 30.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SLIGHT CHANCE FOR LIGHT PCPN LATE THIS AFTERNOON OR EARLY THIS
EVENING.
KREIN
//DISCUSSION...UPDATED 18Z...
THE GUSTY WSWLY WINDS ARE DIMINISHING AS DEEP LOW PRESSURE
CONTINUES TO PULL AWAY TO THE NORTHEAST AND HIGH PRESSURE BUILDS
ACROSS THE MIDDLE MISSISSIPPI VALLEY AND THE OHIO VALLEY. THE WIND
SPEED TREND WILL CONTINUE DOWN...BECMG LGT/VRBL THIS EVENING AND
OVERNIGHT AS THE PRESSURE GRADIENT ACROSS THE REGION BECOMES VERY
WEAK.
A WEAK MID LEVEL IMPULSE TRACKING FROM IOWA THIS AFTERNOON AND
ACROSS THE AREA AROUND THE WISCONSIN-ILLINOIS BORDER HAS THE
POTENTIAL TO GENERATE SOME PCPN...BUT FORECAST MOISTURE PROFILES
INDICATE CONDITIONS BELOW 5KFT SHOULD BE RATHER DRY AND A
SATURATED LAYER WITH WEAK FORCING LOOKS TO RATHER SHALLOW.
SO...WHILE THERE IS A SLIGHT CHANCE FOR RAIN OR A RAIN/SNOW
MIX...CHANCES ARE TOO LOW TO INCLUDE IN THE TAFS...AND MAY
ULTIMATELY END UP BEING MORE VIRGA THAN ACTUAL PCPN REACHING THE
GROUND.
FOR TOMORROW...WITH THE CENTER OF HIGH PRESSURE OVER SRN WISCONSIN
AND A DRY AIRMASS ACROSS THE REGION...EXPECT ONLY OPERATIONALLY
INSIGNIFICANT CLOUD COVER AND LIGHT NELY WINDS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE THAT THE TERMINALS WILL REMAIN DRY THROUGH
THE PERIOD.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...SLIGHT CHANCE OF RAIN.
SATURDAY...RAIN SHOWERS LIKELY. CHANCE OF MVFR/IFR.
SUNDAY...VFR.
MONDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
TUESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
WEDNESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
RODRIGUEZ
&&
.MARINE...
350 AM CST
HIGH WINDS AND WAVES CONTINUING ACROSS THE ENTIRE LAKE THIS
MORNING. THE STRONGEST WINDS ARE CURRENTLY OCCURRING OVER THE
NORTH HALF WHERE STORM FORCE WINDS ARE STILL ONGOING. THESE STORM
FORCE WINDS WILL CONTINUE THROUGH MID MORNING...WITH GALES
PERSISTING THEN INTO THE AFTERNOON. GALES ARE STILL OCCURRING
ACROSS THE SOUTH HALF/NEARSHORE...AND WITH THESE SPEEDS EXPECTED
TO CONTINUE THROUGH MID MORNING AS WELL. SPEEDS WILL CONTINUE TO
DIMINISH OVER THE ENTIRE LAKE THIS AFTERNOON AND THIS
EVENING...WITH A PERIOD OF LIGHTER WINDS TO END THE WORK WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1023 AM CST THU DEC 24 2015
.UPDATE...
1023 AM...MORNING UPDATE...SHORT TERM/HI RES GUIDANCE SUGGESTING
WAVE OVER MISSOURI MAY BE SUFFICIENT FOR SOME SPRINKLES OR BRIEF
LIGHT RAIN ACROSS SOUTH/CENTRAL PARTS OF THE CWA THIS AFTERNOON
AND ADDED SLIGHT CHANCE MENTION OF THIS AFTERNOON. CLOUD COVER
ALSO EXPECTED TO FILL BACK IN WITH THIS WAVE AND THAT MAY KEEP
TEMPS FROM RISING MUCH BEYOND UPPER 30S NORTH TO MID 40S SOUTH.
A SECOND WAVE BACK OVER WESTERN IOWA WILL BE LIFTING NORTHEAST
THIS AFTERNOON AND THIS EVENING. 12Z NAM AND GFS SHOW THE BULK OF
THE PRECIP WITH THIS WAVE LIFTING NORTH OF THE CWA THIS EVENING.
THIS TREND ALSO SEEMS SUPPORTED BY THE RAP THOUGH THE HRRR STILL
MAINTAINS PRECIP INTO THE MID/LATE EVENING...MAINLY ACROSS FAR
NORTHWEST IL. ANY PRECIP THAT DOES OCCUR IS LIKELY TO BE LIGHT
AND WITH TEMPS PROBABLY STILL AT OR ABOVE FREEZING AT THAT
TIME...DOUBTFUL THERE WOULD BE ANY SNOW ACCUMULATION. CMS
&&
.SHORT TERM...
249 AM CST
THROUGH TONIGHT...
WINDS HAVE BEGUN TO CALM DOWN AFTER SEEING GUSTS EARLY THIS MORNING
OVER 40 MPH...BUT WITH SFC RIDGING ARRIVING THE GRADIENT WILL
CONTINUE TO DECREASE THROUGHOUT THE MORNING. BY MIDDAY WINDS SHOULD
BE GENERALLY SOUTHWEST BETWEEN 10 TO 20 MPH. THE LOW THAT BROUGHT
THE SEVERE WEATHER TO THE REGION HAS ALREADY LIFTED TO NEAR JAMES
BAY IN ONTARIO. DESPITE THE QUIET CONDITIONS FOR THE BULK OF THE
DAY...THE LARGEST CHALLENGE WILL BE ON HOW THE STRATUS LAYER
EVOLVES. IR IMAGERY SHOWS A LARGE STRATUS DECK SLIDING SOUTHEAST
ACROSS NORTHERN IL STRETCHING NORTHWEST THROUGH IOWA/MINNESOTA. HI-
RES GUIDANCE CONTINUES TO FEED CLOUDS ACROSS THE NORTHERN HALF OF
THE CWFA...WHICH COULD RESULT IN TEMPS BEING COOLER THEN PRESENT
HIGHS PROGGED AROUND 40 IN THE NORTHWEST AND LOW/MID 40S FOR
CENTRAL/SOUTHERN CWFA. DEW POINTS WILL BE HOVERING IN THE UPR 20S
DUE TO THE LACK OF STRONG SUBSIDENCE.
FURTHER UPSTREAM ACROSS THE CENTRAL ROCKIES IS A STRONGER MID-LVL
VORT...IR IMAGERY IS DEPICTING THIS FEATURE WELL AND MOST
OPERATIONAL SOLUTIONS HAVE THE TRAJECTORY OF THE MID-LVL WAVE
SLIDING EAST/NORTHEAST ACROSS IOWA INTO SOUTHERN WISC BY THIS
EVENING. THE CONCERN IS THAT IF THE STRATUS LAYER REMAINS IN PLACE
ACROSS THE FORECAST AREA...THE MID-LVL WAVE MAY ACT AS A CATALYST
AND QUICKLY SATURATE FROM TOP/DOWN THE PROFILE. WHILE THERE IS A
SHALLOW WARM LAYER...IT IS CONCEIVABLE THAT THIS COULD ERODE QUICKLY
IF DEW POINTS REMAIN IN THE UPR 20S/NEAR 30. IF INDEED THE WAVE
AGITATES THE ENVIRONMENT AND PRODUCES PRECIP...IT WOULD LIKELY FALL
AS RAIN AT THE ONSET...THEN THERMAL COOL DOWN TO SUPPORT A RAIN/SNOW
MIX BEFORE GOING OVER TO LIGHT SNOW AROUND 2-4Z. HAVE OPTED TO BLEND
MORE WITH THE SREF/GFS IN TIMING...BRINGING PRECIP INTO NORTHWEST
CWFA MID/LATE AFTN AND SPREADING EAST TOWARDS THE CHICAGO METRO BY
00-02Z. QPF LOOKS VERY LOW...BUT COULD EASILY SEE WHAT SNOW FALLS TO
PERHAPS PRODUCE A FEW TENTHS OF AN INCH BEFORE ENDING. SFC CONDS
SHOULD BE WARM ENOUGH TO LIMIT ANY ACCUMULATIONS...BUT IF THE MID-
LVL WAVE IS ABLE TO EFFICIENTLY PRODUCE MOISTURE THEN QPF COULD BE
HIGHER AS WELL AS PERHAPS UP TO ONE HALF INCH OF SNOW.
TEMPS OVERNIGHT SHOULD COOL OFF INTO THE UPR 20S IN THE NORTH...BUT
REMAIN IN THE LOW TO PERHAPS MID 30S IN THE FAR SOUTH.
BEACHLER
&&
.LONG TERM...
249 AM CST
FRIDAY THROUGH WEDNESDAY...
CHRISTMAS DAY THROUGH SATURDAY... SFC RIDGING THEN ABSORBS THE
REMAINING LOW LEVEL MOISTURE EARLY CHRISTMAS DAY WITH DRY CONDS AND
P-CLOUDY SKIES EXPECTED FOR MUCH OF THE DAY. WITH THE LACK OF COLD
AIR IN PLACE...TEMPS WILL LIKELY REBOUND INTO THE MID/UPR 40S. ONE
CAVEAT IS THAT WINDS WILL BE TURNING NORTHEAST...WHICH COULD KEEP
THE AREAS ADJACENT TO LAKE MICHIGAN A FEW DEGREES COOLER. BY
CHRISTMAS NIGHT OPERATIONAL GUIDANCE CONTINUES TO PROG A DEVELOPING
SHORTWAVE ACROSS THE LEE-SIDE OF THE SOUTHERN ROCKIES. WITH THE
500MB TROUGH PARKED ACROSS THE FOUR-CORNERS REGION OF THE
CONUS...SOUTHERLY FLOW OF MOISTURE APPEARS POISED TO STREAM NORTH
FROM THE WESTERN GULF. SO TEMPS MAY ONLY FALL SLIGHTLY CHRISTMAS
NIGHT BEFORE WARMING OVERNIGHT. PRECIP SHOULD OVERSPREAD THE REGION
BY EARLY SATURDAY...AND BE WARM ENOUGH INITIALLY TO SUPPORT RAIN.
UNSEASONABLY WARM/MOIST CONDITIONS CONTINUE INTO SAT...WITH DEW
POINTS YET AGAIN PUSHING INTO THE LOW 50S IN THE FAR SOUTHERN CWFA.
GUIDANCE CONTINUES TO INDICATE SOME MID-LVL INSTABILITY WITH A
SERIES OF WEAK SHORTWAVES LIFTING NORTHEAST ALONG A QUASI-STATIONARY
BOUNDARY...SO HAVE HELD ONTO THE MENTION OF THUNDER IN THE SOUTH.
SUNDAY THROUGH WEDNESDAY... FOR THE SECOND HALF OF THE WEEKEND
OPERATIONAL GUIDANCE HAS BEEN BOUNCEING BETWEEN THE PLACEMENT OF THE
FRONTAL BOUNDARY...BUT NOW APPEARS FAVORABLE TO PUSH SOUTH OF THE
FORECAST AREA BY SUN MIDDAY WITH A STRONG CANADIAN SFC RIDGE
DROPPING SOUTH INTO THE NORTHERN PLAINS EARLY SUN...THEN STRETCHING
EAST SUN NGT TO COVER MUCH OF THE GREAT LAKES AND PUSH THE BOUNDARY
FURTHER SOUTH. ENSEMBLES CONTINUE TO SHOW THAT THE SFC RIDGE MAY BE
STRONG ENOUGH TO HOLD THE FRONTAL BOUNDARY FURTHER SOUTH INTO
MONDAY...WHICH MAY FURTHER DELAY MOISTURE FROM LIFTING BACK ACROSS
THE REGION UNTIL MON NGT/TUE.
MID-LVL FLOW DOES BEGIN TO TRANSITION TOWARDS A SEMI-ZONAL SETUP
MON...WHICH COULD AID IN EJECTING THE SFC RIDGE BACK EAST EARLIER
MON AND ALLOW THE BOUNDARY AND DEVELOPING SHORTWAVE TO QUICKLY LIFT
NORTH DURING THE DAY MON. IT IS POSSIBLE THAT THE NORTHERN EDGE OF
THE PRECIP SHIELD...ONCE IT DOES RETURN NORTH...COULD START AS A
WINTRY MIX BEFORE WARMING AND TRANSITIONING OVER TO ALL RAIN. BUT
GIVEN THE LOW CONFIDENCE IN THE PRECISE PLACEMENT OF THE
LOW/BOUNDARY...THIS PERIOD WILL LIKELY UNDERGO ADDITIONAL CHANGES.
TEMPS TOWARDS NEXT WEEK APPEAR TO LEAN TOWARDS CLIMO WITH HIGHS IN
THE LOW/MID 30S...BUT LOWS WILL LIKELY SEE SOME MODERATION GIVEN
EXPECTED CLOUD COVER AND REMAIN IN THE MID/UPR 20S TO AROUND 30.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* GUSTY WEST/SOUTHWEST WINDS THIS MORNING.
* LOW POTENTIAL FOR LIGHT RAIN/SNOW EARLY THIS EVENING.
KREIN
//DISCUSSION...UPDATED 12Z...
GUSTY WESTERLY WINDS PERSISTING THIS MORNING AND WILL LIKELY
CONTINUE OVER THE NEXT SEVERAL HOURS...BUT WITH SPEEDS THEN
EXPECTED TO DIMINISH INTO THE AFTERNOON. WINDS WILL LIKELY BECOME
VARIABLE THIS AFTERNOON INTO THE EVENING BEFORE HOLDING ONTO A
MORE NORTHERLY DIRECTION...BUT STILL LIGHT. MVFR CEILINGS WILL BE
LIKELY THROUGH THE DAY. HOWEVER...THE TERMINALS ARE RIGHT ON THE
EDGE OF THIS CLOUD SHIELD AT THIS TIME. ALTHOUGH THERE MAY SOME
BRIEF PERIODS OF CLEARER SKIES EARLY...THE TREND WILL BE TO CLOUD
BACK UP LATER THIS MORNING. STILL MONITORING THE POTENTIAL FOR
SOME LIGHT PRECIP ACROSS THE AREA LATER THIS AFTERNOON INTO THE
EVENING. CONFIDENCE IS LOW WITH COVERAGE AND PLACEMENT AND HAVE
ONLY MADE MENTION OF VCSH IN THE TAFS. IF THIS WERE TO
DEVELOP...HIGHEST CHANCES WOULD BE NEAR THE RFD/DPA AREA. PRECIP
TYPE COULD ALSO BE A CHALLENGE...AS ITS POSSIBLE THAT RAIN/SNOW
MIX COULD BE OBSERVED.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH WITH WIND SPEED/DIRECTION.
* MEDIUM TO HIGH WITH CEILING TRENDS.
* LOW WITH PCPN POTENTIAL LATER THIS EVENING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...SLIGHT CHANCE OF RAIN.
SATURDAY...RAIN SHOWERS LIKELY. CHANCE OF MVFR/IFR.
SUNDAY...VFR.
MONDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
TUESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
WEDNESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
RODRIGUEZ
&&
.MARINE...
350 AM CST
HIGH WINDS AND WAVES CONTINUING ACROSS THE ENTIRE LAKE THIS
MORNING. THE STRONGEST WINDS ARE CURRENTLY OCCURRING OVER THE
NORTH HALF WHERE STORM FORCE WINDS ARE STILL ONGOING. THESE STORM
FORCE WINDS WILL CONTINUE THROUGH MID MORNING...WITH GALES
PERSISTING THEN INTO THE AFTERNOON. GALES ARE STILL OCCURRING
ACROSS THE SOUTH HALF/NEARSHORE...AND WITH THESE SPEEDS EXPECTED
TO CONTINUE THROUGH MID MORNING AS WELL. SPEEDS WILL CONTINUE TO
DIMINISH OVER THE ENTIRE LAKE THIS AFTERNOON AND THIS
EVENING...WITH A PERIOD OF LIGHTER WINDS TO END THE WORK WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1101 PM CST WED DEC 23 2015
.UPDATE...
ISSUED AT 840 PM CST WED DEC 23 2015
Cold front in the process of pushing through the forecast area
this evening accompanied by strong southwest to west winds gusting
up to 45 mph at times. Strongest surface pressure rises now
shifting quickly to our north this hour suggesting our bout with
strong winds will be short lived with most areas seeing the winds
subside after midnight. The showers and storms quickly exited the
forecast area around 00z with some lower clouds streaming in from
the west signaling a change to cooler weather for the next couple
of days. Have made some adjustments to the forecast with respect
to removing precip for the overnight hours and tweaking the wind
gusts thru late this evening. Expanded the Wind Advisory a bit
further east for the rest of the evening hours as well. Should
have the latest update out by 900 pm.
&&
.SHORT TERM...(Tonight)
ISSUED AT 312 PM CST WED DEC 23 2015
First round of severe weather has exited the eastern forecast area
early this afternoon, but storms have quickly started to fire in
northeast Missouri. This particular area has seen some sunshine
during the afternoon, helping to destabilize the atmosphere, where
CAPE`s are above 500 J/kg and 0-6km bulk shear is an impressive 60-
70 knots. HRRR latched onto this area of development earlier, and
races it across the northern part of the forecast area between 4 pm
and 8 pm. Have concentrated the highest PoP`s for the rest of the
afternoon in this area. The storms should be weakening after sunset
as the surface low pulls northeast, and there is some question about
how much the atmosphere across the eastern CWA can recover after
being thoroughly worked over the last several hours.
Secondary concern is with the winds this evening. Have issued a Wind
Advisory for the period from 6 pm to 2 am across about the northwest
half of the forecast area. Main surface low is currently located
across northeast Iowa, and will be zipping northeast. Impressive 3-
hour pressure rises of 10-11 mb are progged to track northeastward
to around Rockford by midnight. Wind gusts of 45 mph or so are
likely across the northwest half of the forecast area as this
bullseye passes. Have gone as far south as Jacksonville with the
advisory, but this area may be of a shorter duration. Most of the
winds should be diminishing around midnight, but will linger a bit
longer north of I-74.
.LONG TERM...(Thursday through Wednesday)
ISSUED AT 312 PM CST WED DEC 23 2015
Short and medium range models are in fairly good agreement with the
overall active weather pattern through the weekend and into early
next week. Unseasonably warm temperatures and very wet weather will
be the main factors for the weekend through late Monday.
In the shorter term, mild temperatures and periods of cloudiness can
be expected for Christmas Eve into much of Christmas Day. The return
of a surface boundary north of the Ohio Valley and associated weak
isentropic lift initially will result in a chance for light rain in
southeast IL late on Christmas Day. The GFS is the odd model out on
this one by keeping the boundary much farther south.
Backing upper level flow in response to a digging trough in the
western U.S. will allow very warm and moist air to return into much
of central and SE IL during the day Saturday. This feed of moisture
and the associated rainfall will linger in the forecast area through
most of Sunday, resulting in 2.50 to 3.50 inches of rain. The
precipitation area will gradually sag south as the upper low in the
west closes off in SW Texas and an upper level confluent area sets
up across central IL by later in the day Sunday.
The upper low in the southwestern U.S. is expected to kick out
toward the Midwest Monday as another strong upper level trough digs
from the Pacific NW to the southern Plains. This will bring the
likelihood of precipitation back to central IL for Monday. The
forecast type becomes a bit tricky north of a Rushville-Bloomington
line Monday into Monday night as upper level soundings indicate a
mix of rain/snow/sleet possible. Could be some minor accumulations
of snow NW of Peoria late Monday, but there is a lot of uncertainty
with this scenario 6 days out.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1100 PM CST WED DEC 23 2015
The storm system that brought the active weather to our area over
the past 24 hours has shifted well to our north late this evening
which will result in a rapid decrease in wind speeds overnight.
A couple of bands of MVFR cigs were tracking east across the
region tonight with cigs in the 1500-2500 foot range. Will
continue to include a tempo group with these clouds thru about
08-09z with VFR conditions expected after that. Scattered to
broken mid and high level clouds will move in during the morning
on Thursday as a weak weather system pushes across the Plains.
Other than the mid and high clouds, not much else expected with
this system in our area during the day. Westerly winds will
continue their diminishing trend overnight with speeds ranging
from 12 to 20 kts with an occasional gust to 32 kts at times
across the east and north thru about 08z. Winds should begin
to back into the southwest and then south on Thu with speeds
of 10 kts or less.
&&
.ILX Watches/Warnings/Advisories...
Wind Advisory until 2 AM CST Thursday for ILZ027>031-036>038-
040>053.
&&
$$
UPDATE...Smith
SHORT TERM...Geelhart
LONG TERM...Miller
AVIATION...Smith
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
530 PM CST FRI DEC 25 2015
.UPDATE...
Issued at 530 PM CST FRI DEC 25 2015
Updated 00Z aviation discussion.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 112 PM CST FRI DEC 25 2015
HRRR keeps all pcpn out (south and east) of FA thru midnight
tonight. It`s even sparse on bringing it in after, although it
only runs thru 08z at this writing. The synoptic scale models are
not doing as good a job seeing the convection to the south (MS/AL)
and its negating effect on the northern extent of the pcpn
shield. Thus the nearly half inch qpf in our southern counties
thru midnight, will be discarded.
After midnight, we should see the boundary return as a warm front
slowly but surely. Pcpn will start, and get going pretty good,
certainly by midday tmrw, if not before. Where will the boundary
be? The synoptic models suggest it will set up somewhere along the
lower OH by early pm, but they could contain the same bias and
thus it be actually 50-75 miles south of there, or, just entering
the FA. Either case, rain should pick up to categorical tmrw, as
the warm front lifts thru the region. As it does so, low level
winds pick up, and elevated instability becomes sufficient for
embedded thunder. Some low layer mucape is present as well, so
we`ll include a chance, or slgt chance, thunder, with the lift
thru of the warm front. Expect 1/2 to 3/4 inches areal average qpf
with this round.
We have the warm front lifted across the area by 00Z Sunday, with
the aforementioned convective caveat perhaps hanging up its lift
in entirety. We`ve lingered higher pops along the northern and
western counties to account for that...and extend that trend thru
Saturday night. It`s possible showers become more widely
scattered/scarce further east with time...so we`ve lowered pops
there (southern Pennyrile) to account for that. We`ve slightly
adjusted forecast QPF similarly with these two trends (up n/w,
down s/e) just a little.
Sunday-Sunday night offers the best chance for heavier
rains/additional qpf, particularly for our northern and western
counties. The sagging front interaction with the incoming parent
Low pressure systems may set up a weak zone of baroclinicity that
allows for enhanced pcpn/qpf potential there. Hence the qpf
bullseye of 4-5" across SEMO into SWIL, where the FFA exists. Per
collab with LMK, we`ll lay off headline FFA for points east for
now, as these aforementioned heavier/cumulative qpf rains may be
more in the late Sunday-Sunday night-Monday time frame there.
.LONG TERM...(Monday through Friday)
Issued at 200 PM CST FRI DEC 25 2015
Forecast confidence is average to above average in the long term
portion of the forecast. Overall synoptic scale model forecasts are
in generally good agreement. However, smaller scale details remain
somewhat in flux--especially with respect to how quickly the system
and heavy rains depart the area early in the week.
The main concern to start the long term is the continued potential
for flooding from the rain event slated to get underway over the
weekend. In collaboration with the short term, a Flash Flood Watch
will continue through Monday for most of southeast Missouri and
northern/western portions of southern Illinois. During this time,
the primary closed upper low is forecast to move northeast from the
southern Plains into the Great Lakes Region. Forecast currently
relies largely on a consensus blend of recent model data. However,
latest 12Z runs of the GFS, ECMWF, NAM, and GEM seem to suggest much
of the area may be dry slotted by late Monday morning and afternoon.
If this does pan out, a lowering of rain chances and forecast
precipitation totals may become necessary in future forecasts for
Monday.
Once the storm system and heavy rain have cleared the area, a return
to mainly dry conditions is anticipated through the remainder of the
week. The southwesterly upper flow pattern will persist through mid
week. Thereafter, a substantial shift to the pattern is anticipated
as an upper level ridge builds in the west and a trough sets up in
the east. The resultant transition to a northwest flow pattern will
usher much colder air into the region by mid to late week. As this
transition occurs, the passage of our next system may yield some
light precipitation around Wednesday. However, with most of the Gulf
moisture remaining to our south, any precipitation would likely
remain on the light side.
&&
.AVIATION...
Issued at 530 PM CST FRI DEC 25 2015
Satellite/radar and HRRR model data all paint a relatively dry
first half of forecast, at least for the first 6 hours. A warm
front will return this evening and overnight, and with it, MVFR
restricted cigs/vsbys and light rain. Mvfr cigs are already on
their way back northward and have accounted for this in the fcst.
By late tonight and into tmrw morning, pockets of heavier rain
with the front`s passage will be presenting IFR cigs/vsbys as
flight hazards, and restricted flight rules will continue thru the
remainder of the morning. The rain should be north of the sites by
afternoon.
&&
.PAH Watches/Warnings/Advisories...
IL...Flash Flood Watch from Saturday afternoon through Monday
afternoon for ILZ075>078-080>082-084.
MO...Flash Flood Watch from Saturday afternoon through Monday
afternoon for MOZ076-086-087-100-107>111-114.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
320 PM EST THU DEC 24 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 320 PM EST THU DEC 24 2015
19Z SFC ANALYSIS SHOWS A RELATIVE AREA OF HIGH PRESSURE OVER THE
OHIO VALLEY WHILE LOW PRESSURE IS BUILDING TO THE SOUTHWEST. ON
SATELLITE...A BRIEF PERIOD OF LOW CLOUDS AROUND MIDDAY HAVE
BROKEN UP AND SCATTERED OUT DURING THE EARLY AFTERNOON LEAVING
MOSTLY SUNNY CONDITIONS. THAT SUNSHINE...AND SOME LIMITED
DRYING...RESULTED IN TEMPERATURES SPIKING INTO THE UPPER 60S AND
LOWER 70S THROUGH EAST KENTUCKY THIS AFTERNOON. DEWPOINTS HAVE
FALLEN INTO THE LOW AND MID 50S..BUT ARE STILL VERY HIGH FOR THIS
TIME OF YEAR. MEANWHILE...WINDS ARE LIGHT AND VARIABLE THROUGH THE
AREA...GENERALLY FROM THE SOUTH FOR LOCATIONS SOUTH OF THE
MOUNTAIN PARKWAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE LONGWAVE PATTERN
AS THEY ALL SHOW THE SOUTHEAST RIDGE STRENGTHENING AND WOBBLING
WEST INTO FRIDAY WHILE LARGE AND FAIRLY STRONG TROUGHING DIVES
INTO THE DESERT SOUTHWEST. THIS WILL ALL SERVE TO STRENGTHEN THE
BROAD AND DEEP SOUTHWEST FLOW THROUGH THE REGION INTO SATURDAY
MORNING. WHILE THE MAJORITY OF THE ENERGY IN THIS PATTERN WILL
STAY WITH THE WESTERN TROUGH...THERE WILL BE A FEW WEAK WAVES THAT
RIDE OVER THE AREA DURING THE SHORT TERM PORTION OF THE FORECAST.
OF MOST SIGNIFICANCE WILL BE THE RECORD OR NEAR RECORD HIGH PW
AIR IN PLACE OVER THE REGION DURING THE DAY FRIDAY INTO
SATURDAY...THAT THE MODELS ARE PRETTY MUCH IN CONCURRENCE WITH.
AS SUCH...WILL FOLLOW A BLENDED MODEL SOLUTION FAVORING THE HIGHER
RESOLUTION HRRR AND NAM12 ALONG WITH INPUT FROM THE NATIONAL
CENTERS.
SENSIBLE WEATHER WILL FEATURE A CONTINUATION OF OUR VERY WARM
HOLIDAY PERIOD WITH TEMPERATURES NOT FALLING TOO FAR INTO THE 50S
FOR MOST SPOTS TONIGHT. ALTHOUGH...AM EXPECTING A BIT OF A RIDGE
TO VALLEY TEMPERATURE SPLIT THIS EVENING AND INTO THE FIRST PART
OF THE OVERNIGHT. THIS SHOULD BE MOST NOTICEABLE IN THE FAR
EASTERN SHELTERED VALLEYS AND IS EXPECTED TO MIX OUT TOWARDS DAWN.
THE NEXT SURGE IN PCPN WILL LIKELY MOVE IN FROM THE SOUTHWEST
AROUND DAWN AS WELL AND OVERSPREAD THE ENTIRE CWA BY MID MORNING.
EXPECT LIGHT TO MODERATE SHOWERS ALONG WITH A POTENTIAL FOR
THUNDERSTORMS INTO THE DAY FRIDAY AS AN INVERTED TROUGH/SFC WAVE
MOVES THROUGH KENTUCKY. THIS WILL ACTIVATE THE HIGH MOISTURE
CONTENT IN PLACE AND COULD LEAD TO TRAINING ISSUES IN A FEW
SPOTS...PARTICULARLY THOSE THAT MAY HAVE SEEN SATURATING TO HEAVY
RAINS OVER THE PAST DAY OR SO. DO EXPECT THE HIGHEST RAINFALL
TOTALS THROUGH SATURDAY MORNING TO FALL OVER THE CUMBERLAND
VALLEY BEFORE THE RESPONSIBLE WAVE PULLS OUT OF THE AREA EARLY
SATURDAY. GIVEN THE POTENTIAL HAVE DECIDED TO ISSUE A FLOOD WATCH
STARTING AT 6 AM FRIDAY AND RUNNING THROUGH 8 AM SATURDAY...WITH
BETWEEN 1.5 AND 2.5 INCHES OF RAIN POSSIBLE DURING THIS TIME
FRAME. THIS WATCH WILL COVER POINTS GENERALLY SOUTH OF INTERSTATE
64. CONFIDENCE IS FAIRLY HIGH THAT A GOOD SWATH OF RAIN WILL FALL
OVER A GOOD PORTION OF THE CWA DURING THIS TIME...BUT LOW FOR ANY
PARTICULAR PLACEMENT GIVEN SOME DISCREPANCIES WITH THE HIGHEST
AXIS OF QPF FROM EACH MODEL. IN ADDITION...THE CONCERN FOR HEAVY
RAIN WILL RUN INTO THE NEW WEEK AND FOR THAT OVERARCHING RAINFALL
THREAT WILL ISSUE AN ESF.
FOR TEMPERATURES AND DEWPOINTS...HAVE MAINLY GONE WITH THE
SHORTBLEND GUIDANCE THROUGH FRIDAY MORNING AND THEN THE SUPERBLEND
INTO SATURDAY MORNING. DID MAKE SOME NEAR TERM ADJUSTMENTS INTO
THE FIRST PART OF THE NIGHT FOR A PARTIAL AND BRIEF RIDGE TO
VALLEY TEMPERATURE SPLIT. NOT EXPECTING MUCH OF A DIFFERENCE IN
TEMPS FRIDAY NIGHT GIVEN THE PCPN. AS FOR POPS...ENDED UP ON THE
HIGH SIDE OF GUIDANCE THROUGH THE PERIOD...ESPECIALLY TONIGHT AT
LOZ WHERE THE WETTER MET NUMBERS WERE PREFERRED.
WHILE RECORD HIGH MINIMUM TEMPERATURES ARE EXPECTED BOTH TONIGHT
AND FRIDAY NIGHT...HIGH TEMPERATURE RECORDS FOR TOMORROW WILL
LIKELY NOT FALL DUE TO A VERY WARM CHRISTMAS BACK IN 1982.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 PM EST THU DEC 24 2015
THE MAIN CONCERN FOR THIS PERIOD WILL BE THE POTENTIAL FOR
REPEATING ROUNDS OF RAINFALL THROUGH EARLY NEXT WEEK WITH A DEEP
AND MOISTURE LADEN SOUTHWEST FLOW IN PLACE ALOFT. A WAVY FRONTAL
BOUNDARY WILL LIFT NORTHWARD ACROSS OUR AREA ON SATURDAY ALLOWING
FOR A BREAK IN THE RAINFALL FOR MOST OF EASTERN KENTUCKY FROM
SATURDAY AFTERNOON THROUGH SUNDAY MORNING. FOR THIS REASON...THE
FLOOD WATCH ISSUED WILL ONLY RUN THROUGH AROUND DAWN ON SATURDAY.
HOWEVER...DEEPENING LOW PRESSURE WILL DRIVE NORTHEASTWARD OUT OF
TEXAS LATE IN THE WEEKEND INTO THE DAY ON MONDAY AND THIS WILL
SEND THE FRONT AND A LOAD OF MOISTURE BACK ACROSS THE REGION
BEGINNING SUNDAY AFTERNOON AND LASTING THROUGH MONDAY NIGHT. A
COUPLE OF INCHES OF ADDITIONAL RAINFALL IS LIKELY DURING THIS SECOND
WAVE OF RAIN...WHICH WILL LIKELY CAUSE ADDITIONAL FLOOD CONCERNS.
THIS SYSTEM WILL EXIT TO OUR EAST WITH DIMINISHING RAIN CHANCES ON
TUESDAY.
THE OTHER STORY TO TOUCH ON IS THE UNSEASONABLE WARMTH. PROGGED
850 MB TEMPS ON SATURDAY OF AROUND 15C ARE CLOSE TO RECORD HIGHS
ACCORDING TO SPC SOUNDING CLIMATOLOGY. HIGH TEMPS ARE FORECAST TO
EASILY ECLIPSE RECORDS SATURDAY BY CLIMBING INTO THE LOW TO MID
70S. THIS MAY BE CONSERVATIVE IF CLOUDS SCATTER OUT FOR ANY LENGTH
OF TIME. TEMPS ON SUNDAY WILL AGAIN THREATEN RECORDS AS THEY CLIMB
TO AROUND 70 SOUTH OF I-64...BEFORE A COOLER BUT STILL ABOVE NORMAL
AIRMASS FILTERS IN BEHIND THE FRONT FOR THE MIDDLE OF NEXT WEEK. IF
OUR FORECAST PANS OUT THROUGH DECEMBER 31ST...THIS WILL EASILY BE
THE WARMEST DECEMBER ON RECORD AT BOTH JKL AND LOZ. IN FACT...OUR
AVERAGE TEMPERATURE THIS DECEMBER AT JKL AND LOZ WILL LIKELY BE A
COUPLE DEGREES WARMER THAN THE AVERAGE NOVEMBER TEMPERATURE AT
THOSE SITES WHEN ALL IS SAID AND DONE!
BEYOND TUESDAY...FORECAST MODELS KEEP US IN SOUTHWEST FLOW ALOFT
WITH ANOTHER SHORTWAVE PROGGED TO BRING ANOTHER ROUND OF SHOWERS
WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY A RETURN TO MORE
SEASONAL TEMPERATURES BY NEW YEARS EVE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 115 PM EST THU DEC 24 2015
MAINLY VFR CEILINGS WILL PREVAIL INTO THE FIRST PART OF THE NIGHT
THEN LOWER DOWN TO MVFR TOWARD DAWN FRIDAY AND INTO OR NEAR IFR
THROUGH THE END OF THE PERIOD. SHOWERS AND A FEW RUMBLES OF
THUNDER WILL BE MOVING BACK IN AROUND DAWN IN THE SOUTHWEST AND BY
13Z ELSEWHERE. WINDS WILL AVERAGE AROUND 5 KTS OR LESS THROUGH THE
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM FRIDAY MORNING THROUGH SATURDAY MORNING FOR
KYZ058>060-068-069-079-080-083>088-104-106>120.
&&
$$
SHORT TERM...GREIF
LONG TERM...ABE
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
130 PM EST THU DEC 24 2015
.UPDATE...
ISSUED AT 130 PM EST THU DEC 24 2015
DID A QUICK UPDATE TO THE GRIDS TO CAPTURE THE CURRENT CONDITIONS
INCLUDING SKY COVER THROUGH THE REST OF THE DAY. THESE GRIDS HAVE
BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1045 AM EST THU DEC 24 2015
15Z SFC ANALYSIS SHOWS A WEAK AND FLEETING AREA OF HIGH PRESSURE
MOVING OVER THE LOWER OHIO VALLEY IN THE WAKE OF A LOW PRESSURE
WAVE DEPARTING TO THE EAST. THIS WAVE PULLED THE LAST OF THE
SHOWERS OUT OF THE AREA AROUND DAWN AND HAS ALSO TAKEN THE BULK OF
THE LOW AND MID LEVEL CLOUDS OUT AS WELL. TEMPERATURES THROUGH
EAST KENTUCKY STARTED OUT WARM AND HAVE BASICALLY HELD STEADY AS
THE INSOLATION IS COUNTERING THE LIMITED CAA IN THE WAKE OF THE
LOW. NORTHWEST PARTS OF THE AREA HAVE MANAGED TO SETTLE INTO THE
UPPER 50S WHILE THE REST OF THE AREA IS GENERALLY IN THE LOW 60S.
EXPECT A REBOUND TO THE NORTHWEST TEMPS BY MID AFTERNOON WHILE THE
THERMOMETERS OF THE REST OF EASTERN KENTUCKY CREEP UP TOWARD THE
MID AND UPPER 60S. SOME DRIER AIR IS INBOUND WITH THE HIGH
PRESSURE AS WELL AND READINGS CURRENTLY REFLECT THAT...VARYING
FROM THE UPPER 40S IN THE NORTHWEST TO THE UPPER 50S AND LOW 60S
IN THE SOUTHEAST TWO THIRDS OF THE CWA. WINDS HAVE TURNED TO THE
NORTHWEST FOR MUCH OF EASTERN KENTUCKY...BUT ARE STILL CALM OR
SOUTHWEST NEARER TO WEST VIRGINIA AND VIRGINIA. HAVE UPDATED THE
FORECAST TO REFLECT LESS SKY COVER AND NEAR ZERO POPS THROUGH THE
REST OF THE DAY ALONG WITH ADDING IN THE LATEST SHORTBLEND
GUIDANCE FOR THE T AND TD GRIDS. THESE HAVE BEEN FINALIZED WITH
THE CURRENT OBS AND TRENDS. THE UPDATED GRIDS HAVE BEEN SENT TO
THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 757 AM EST THU DEC 24 2015
PRECIPITATION HAS EXITED THE AREA...AND THE LATEST HRRR HAS BEEN
SHOWING NO OTHER ACTIVITY FOR THE REST OF THE DAY. THIS SEEMS
REASONABLE GIVEN THE LACK OF FORCING. AS SUCH...HAVE REMOVED POPS
FOR THE REST OF THE DAY. ALSO FRESHENED UP THE HOURLY TEMPERATURES
AND DEW POINTS BASED ON THE LATEST TRENDS IN OBSERVATIONS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 359 AM EST THU DEC 24 2015
A SURFACE COLD FRONT...STEMMING FROM DEEP LOW PRESSURE CENTERED
ACROSS SOUTH CENTRAL ONTARIO...IS ALIGNED FROM EASTERN INDIANA
DOWN ACROSS CENTRAL KENTUCKY. CONVECTION HAS RACED WELL OUT AHEAD
OF THE BOUNDARY...BEING SUSTAINED BY A STOUT LOW LEVEL JET. THE
WIDESPREAD ACTIVITY HAS ALL BUT CLEARED FAR SOUTHEASTERN
KENTUCKY...WITH JUST A FEW SHOWERS LINGERING BEHIND THE MAIN LINE.
CURRENT OVERNIGHT TEMPERATURES ARE STILL RUNNING WELL ABOVE THE
NORMAL DAYTIME HIGHS FOR THIS TIME OF YEAR...WITH READINGS
RANGING FROM THE UPPER 50S TO LOWER 60S. ALOFT...DEEP TROUGHING
RULES ACROSS THE WESTERN TWO THIRDS OF THE NATION...WITH A MORE
SUMMER-LIKE HIGH POSITIONED ACROSS THE WESTERN ATLANTIC.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM.
CONVECTION WILL CONTINUE TO WANE ACROSS OUR AREA...AS THE LOW
LEVEL JET DIMINISHES AND THE SURFACE COLD FRONT GETS SHEARED
OUT. PASSING HIGH PRESSURE TO OUR NORTH WILL KEEP THINGS DRY
THROUGH MOST OF TONIGHT. MEANWHILE...THE NEXT BIG CHUNK OF ENERGY
WILL BE DIGGING IN FROM THE EASTERN PACIFIC. THIS WILL ALLOW AN
INVERTED SURFACE TROUGH TO DEVELOP AND NOSE IN FROM THE SOUTHWEST
BY EARLY CHRISTMAS DAY...WITH ANOTHER ROUND OF WIDESPREAD SHOWERS
AND A FEW THUNDERSTORMS POSSIBLE.
THE MODELS HAVE BEEN VARYING WITH THE AMOUNT AND POSITION OF THE
HEAVIER QPF...WITH THE ECMWF AND NAM BEEFIER...WHILE THE GFS HAS
BEEN LEANER. GIVEN THE FACT THAT THERE IS WEAK MID AND UPPER LEVEL
FORCING...AM INCLINED TO PUT MORE CONFIDENCE IN THE LEANER TOTALS
FOR NOW. STILL...PWATS ARE EXTREMELY HIGH AND ANY TRAINING
THUNDERSTORM ACTIVITY COULD CERTAINLY BRING TOTALS MORE TOWARDS
THE HIGHER END...UPWARDS OF 2 INCHES IN A 6 TO 12 HOUR PERIOD.
CONSEQUENTLY...WILL CONTINUE TO MENTION GENERALIZED FLOODING
CONCERNS IN THE HWO.
FOR TEMPERATURES...A MORE DIURNALLY LIMITED REGIME WAS
FAVORED...GIVEN THE CLOUDS AND QUICK RETURN OF PRECIPITATION BY
CHRISTMAS DAY. HIGHS TODAY WILL RANGE FROM THE MID TO UPPER
60S...WITH READINGS MORE IN THE LOW TO MID 60S FOR THE HOLIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 359 AM EST THU DEC 24 2015
MODELS ARE IN GENERALLY GOOD AGREEMENT ON THE MILD AND WET PATTERN
PERSISTING THROUGH THE WEEKEND INTO NEXT WEEK. IT DOES LOOK LIKE THE
WARM FRONT SHOULD LIFT NORTH FRIDAY NIGHT INTO EARLY SATURDAY WITH
RAIN CHANCES LIFTING NORTH OF THE AREA. THUS...MUCH OF SATURDAY
COULD END UP ON THE DRIER SIDE (WHICH WOULD NOT BE A BAD THING). IF
THE DRIER FORECAST PANS OUT...TEMPERATURES COULD SOAR INTO THE LOW
TO MID 70S SOUTH OF THE WARM FRONT...SETTING UP ANOTHER RECORD
BREAKING DAY. IF CLOUDS HOLD ON OR PRECIPITATION HOLDS ON
LONGER...WE MIGHT HAVE TO SETTLE FOR READINGS CLOSER TO 70...BUT
STILL MILD. PRECIPITATION STAYS NORTH INTO SATURDAY NIGHT...BUT THE
FRONT WILL BE DRIVEN BACK TO THE SOUTH ON SUNDAY WITH RAIN CHANCES
RAMPING BACK UP. THE FRONT WILL THEN STALL IN OUR VICINITY KEEPING
THE WEATHER UNSETTLED INTO MONDAY. FINALLY A COLD FRONT SHOULD SWEEP
ACROSS THE AREA MONDAY NIGHT/TUESDAY...BRINGING AN END TO THE
EXTENDED PERIOD OF WET AND MILD WEATHER. TEMPERATURES WILL TAKE A
HIT BY WEDNESDAY WITH HIGHS BACK INTO THE LOWER 50S (BUT STILL ABOVE
NORMAL!). A SECONDARY COLD FRONT COULD BRING A BETTER SURGE OF
COLDER AIR AS WE HEAD INTO NEW YEARS EVE...BRINGING A RETURN OF
MORE SEASONABLE WINTER WEATHER TO EASTERN KENTUCKY.
FORTUNATELY...DESPITE IT TURNING COLDER NEXT WEEK...STILL NO SIGNS
OF ANY SNOWFALL FOR OUR NECK OF THE WOODS.
WITH ALL THE RAIN EXPECTED ON FRIDAY/FRIDAY NIGHT...COUPLED WITH THE
RAIN SUNDAY INTO TUESDAY...WE WILL CONTINUE TO HAVE TO MONITOR
CONDITIONS FOR POSSIBLE FLOODING...ESPECIALLY ON THE RIVERS AND
CREEKS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 115 PM EST THU DEC 24 2015
MAINLY VFR CEILINGS WILL PREVAIL INTO THE FIRST PART OF THE NIGHT
THEN LOWER DOWN TO MVFR TOWARD DAWN FRIDAY AND INTO OR NEAR IFR
THROUGH THE END OF THE PERIOD. SHOWERS AND A FEW RUMBLES OF
THUNDER WILL BE MOVING BACK IN AROUND DAWN IN THE SOUTHWEST AND BY
13Z ELSEWHERE. WINDS WILL AVERAGE AROUND 5 KTS OR LESS THROUGH THE
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GEOGERIAN
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1045 AM EST THU DEC 24 2015
.UPDATE...
ISSUED AT 1045 AM EST THU DEC 24 2015
15Z SFC ANALYSIS SHOWS A WEAK AND FLEETING AREA OF HIGH PRESSURE
MOVING OVER THE LOWER OHIO VALLEY IN THE WAKE OF A LOW PRESSURE
WAKE DEPARTING TO THE EAST. THIS WAVE PULLED THE LAST OF THE
SHOWERS OUT OF THE AREA AROUND DAWN AND HAS ALSO TAKEN THE BULK OF
THE LOW AND MID LEVEL CLOUDS OUT AS WELL. TEMPERATURES THROUGH
EAST KENTUCKY STARTED OUT WARM AND HAVE BASICALLY HELD STEADY AS
THE INSOLATION IS COUNTERING THE LIMITED CAA IN THE WAKE OF THE
LOW. NORTHWEST PARTS OF THE AREA HAVE MANAGED TO SETTLE INTO THE
UPPER 50S WHILE THE REST OF THE AREA IS GENERALLY IN THE LOW 60S.
EXPECT A REBOUND TO THE NORTHWEST TEMPS BY MID AFTERNOON WHILE THE
THERMOMETERS OF THE REST OF EASTERN KENTUCKY CREEP UP TOWARD THE
MID AND UPPER 60S. SOME DRIER AIR IS INBOUND WITH THE HIGH
PRESSURE AS WELL AND READINGS CURRENTLY REFLECT THAT...VARYING
FROM THE UPPER 40S IN THE NORTHWEST TO THE UPPER 50S AND LOW 60S
IN THE SOUTHEAST TWO THIRDS OF THE CWA. WINDS HAVE TURNED TO THE
NORTHWEST FOR MUCH OF EASTERN KENTUCKY...BUT ARE STILL CALM OR
SOUTHWEST NEARER TO WEST VIRGINIA AND VIRGINIA. HAVE UPDATED THE
FORECAST TO REFLECT LESS SKY COVER AND NEAR ZERO POPS THROUGH THE
REST OF THE DAY ALONG WITH ADDING IN THE LATEST SHORTBLEND
GUIDANCE FOR THE T AND TD GRIDS. THESE HAVE BEEN FINALIZED WITH
THE CURRENT OBS AND TRENDS. THE UPDATED GRIDS HAVE BEEN SENT TO
THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 757 AM EST THU DEC 24 2015
PRECIPITATION HAS EXITED THE AREA...AND THE LATEST HRRR HAS BEEN
SHOWING NO OTHER ACTIVITY FOR THE REST OF THE DAY. THIS SEEMS
REASONABLE GIVEN THE LACK OF FORCING. AS SUCH...HAVE REMOVED POPS
FOR THE REST OF THE DAY. ALSO FRESHENED UP THE HOURLY TEMPERATURES
AND DEW POINTS BASED ON THE LATEST TRENDS IN OBSERVATIONS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 359 AM EST THU DEC 24 2015
A SURFACE COLD FRONT...STEMMING FROM DEEP LOW PRESSURE CENTERED
ACROSS SOUTH CENTRAL ONTARIO...IS ALIGNED FROM EASTERN INDIANA
DOWN ACROSS CENTRAL KENTUCKY. CONVECTION HAS RACED WELL OUT AHEAD
OF THE BOUNDARY...BEING SUSTAINED BY A STOUT LOW LEVEL JET. THE
WIDESPREAD ACTIVITY HAS ALL BUT CLEARED FAR SOUTHEASTERN
KENTUCKY...WITH JUST A FEW SHOWERS LINGERING BEHIND THE MAIN LINE.
CURRENT OVERNIGHT TEMPERATURES ARE STILL RUNNING WELL ABOVE THE
NORMAL DAYTIME HIGHS FOR THIS TIME OF YEAR...WITH READINGS
RANGING FROM THE UPPER 50S TO LOWER 60S. ALOFT...DEEP TROUGHING
RULES ACROSS THE WESTERN TWO THIRDS OF THE NATION...WITH A MORE
SUMMER-LIKE HIGH POSITIONED ACROSS THE WESTERN ATLANTIC.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM.
CONVECTION WILL CONTINUE TO WANE ACROSS OUR AREA...AS THE LOW
LEVEL JET DIMINISHES AND THE SURFACE COLD FRONT GETS SHEARED
OUT. PASSING HIGH PRESSURE TO OUR NORTH WILL KEEP THINGS DRY
THROUGH MOST OF TONIGHT. MEANWHILE...THE NEXT BIG CHUNK OF ENERGY
WILL BE DIGGING IN FROM THE EASTERN PACIFIC. THIS WILL ALLOW AN
INVERTED SURFACE TROUGH TO DEVELOP AND NOSE IN FROM THE SOUTHWEST
BY EARLY CHRISTMAS DAY...WITH ANOTHER ROUND OF WIDESPREAD SHOWERS
AND A FEW THUNDERSTORMS POSSIBLE.
THE MODELS HAVE BEEN VARYING WITH THE AMOUNT AND POSITION OF THE
HEAVIER QPF...WITH THE ECMWF AND NAM BEEFIER...WHILE THE GFS HAS
BEEN LEANER. GIVEN THE FACT THAT THERE IS WEAK MID AND UPPER LEVEL
FORCING...AM INCLINED TO PUT MORE CONFIDENCE IN THE LEANER TOTALS
FOR NOW. STILL...PWATS ARE EXTREMELY HIGH AND ANY TRAINING
THUNDERSTORM ACTIVITY COULD CERTAINLY BRING TOTALS MORE TOWARDS
THE HIGHER END...UPWARDS OF 2 INCHES IN A 6 TO 12 HOUR PERIOD.
CONSEQUENTLY...WILL CONTINUE TO MENTION GENERALIZED FLOODING
CONCERNS IN THE HWO.
FOR TEMPERATURES...A MORE DIURNALLY LIMITED REGIME WAS
FAVORED...GIVEN THE CLOUDS AND QUICK RETURN OF PRECIPITATION BY
CHRISTMAS DAY. HIGHS TODAY WILL RANGE FROM THE MID TO UPPER
60S...WITH READINGS MORE IN THE LOW TO MID 60S FOR THE HOLIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 359 AM EST THU DEC 24 2015
MODELS ARE IN GENERALLY GOOD AGREEMENT ON THE MILD AND WET PATTERN
PERSISTING THROUGH THE WEEKEND INTO NEXT WEEK. IT DOES LOOK LIKE THE
WARM FRONT SHOULD LIFT NORTH FRIDAY NIGHT INTO EARLY SATURDAY WITH
RAIN CHANCES LIFTING NORTH OF THE AREA. THUS...MUCH OF SATURDAY
COULD END UP ON THE DRIER SIDE (WHICH WOULD NOT BE A BAD THING). IF
THE DRIER FORECAST PANS OUT...TEMPERATURES COULD SOAR INTO THE LOW
TO MID 70S SOUTH OF THE WARM FRONT...SETTING UP ANOTHER RECORD
BREAKING DAY. IF CLOUDS HOLD ON OR PRECIPITATION HOLDS ON
LONGER...WE MIGHT HAVE TO SETTLE FOR READINGS CLOSER TO 70...BUT
STILL MILD. PRECIPITATION STAYS NORTH INTO SATURDAY NIGHT...BUT THE
FRONT WILL BE DRIVEN BACK TO THE SOUTH ON SUNDAY WITH RAIN CHANCES
RAMPING BACK UP. THE FRONT WILL THEN STALL IN OUR VICINITY KEEPING
THE WEATHER UNSETTLED INTO MONDAY. FINALLY A COLD FRONT SHOULD SWEEP
ACROSS THE AREA MONDAY NIGHT/TUESDAY...BRINGING AN END TO THE
EXTENDED PERIOD OF WET AND MILD WEATHER. TEMPERATURES WILL TAKE A
HIT BY WEDNESDAY WITH HIGHS BACK INTO THE LOWER 50S (BUT STILL ABOVE
NORMAL!). A SECONDARY COLD FRONT COULD BRING A BETTER SURGE OF
COLDER AIR AS WE HEAD INTO NEW YEARS EVE...BRINGING A RETURN OF
MORE SEASONABLE WINTER WEATHER TO EASTERN KENTUCKY.
FORTUNATELY...DESPITE IT TURNING COLDER NEXT WEEK...STILL NO SIGNS
OF ANY SNOWFALL FOR OUR NECK OF THE WOODS.
WITH ALL THE RAIN EXPECTED ON FRIDAY/FRIDAY NIGHT...COUPLED WITH THE
RAIN SUNDAY INTO TUESDAY...WE WILL CONTINUE TO HAVE TO MONITOR
CONDITIONS FOR POSSIBLE FLOODING...ESPECIALLY ON THE RIVERS AND
CREEKS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 757 AM EST THU DEC 24 2015
MVFR CEILINGS SHOULD GRADUALLY RAISE UP TO VFR THROUGH THIS
MORNING AS A WEAK AREA OF HIGH PRESSURE BUILDS IN ACROSS THE OHIO
VALLEY. CEILINGS WILL THEN LOWER DOWN TO MVFR LATER TONIGHT AND
THEN IFR THROUGH THE END OF THE PERIOD. RAIN SHOWERS WILL BE
MOVING BACK IN BY CHRISTMAS DAY. WINDS WILL AVERAGE AROUND 5 KTS
OR LESS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GEOGERIAN
LONG TERM...KAS
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
757 AM EST THU DEC 24 2015
.UPDATE...
ISSUED AT 757 AM EST THU DEC 24 2015
PRECIPITATION HAS EXITED THE AREA...AND THE LATEST HRRR HAS BEEN
SHOWING NO OTHER ACTIVITY FOR THE REST OF THE DAY. THIS SEEMS
REASONABLE GIVEN THE LACK OF FORCING. AS SUCH...HAVE REMOVED POPS
FOR THE REST OF THE DAY. ALSO FRESHENED UP THE HOURLY TEMPERATURES
AND DEW POINTS BASED ON THE LATEST TRENDS IN OBSERVATIONS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 359 AM EST THU DEC 24 2015
A SURFACE COLD FRONT...STEMMING FROM DEEP LOW PRESSURE CENTERED
ACROSS SOUTH CENTRAL ONTARIO...IS ALIGNED FROM EASTERN INDIANA
DOWN ACROSS CENTRAL KENTUCKY. CONVECTION HAS RACED WELL OUT AHEAD
OF THE BOUNDARY...BEING SUSTAINED BY A STOUT LOW LEVEL JET. THE
WIDESPREAD ACTIVITY HAS ALL BUT CLEARED FAR SOUTHEASTERN
KENTUCKY...WITH JUST A FEW SHOWERS LINGERING BEHIND THE MAIN LINE.
CURRENT OVERNIGHT TEMPERATURES ARE STILL RUNNING WELL ABOVE THE
NORMAL DAYTIME HIGHS FOR THIS TIME OF YEAR...WITH READINGS
RANGING FROM THE UPPER 50S TO LOWER 60S. ALOFT...DEEP TROUGHING
RULES ACROSS THE WESTERN TWO THIRDS OF THE NATION...WITH A MORE
SUMMER-LIKE HIGH POSITIONED ACROSS THE WESTERN ATLANTIC.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM.
CONVECTION WILL CONTINUE TO WANE ACROSS OUR AREA...AS THE LOW
LEVEL JET DIMINISHES AND THE SURFACE COLD FRONT GETS SHEARED
OUT. PASSING HIGH PRESSURE TO OUR NORTH WILL KEEP THINGS DRY
THROUGH MOST OF TONIGHT. MEANWHILE...THE NEXT BIG CHUNK OF ENERGY
WILL BE DIGGING IN FROM THE EASTERN PACIFIC. THIS WILL ALLOW AN
INVERTED SURFACE TROUGH TO DEVELOP AND NOSE IN FROM THE SOUTHWEST
BY EARLY CHRISTMAS DAY...WITH ANOTHER ROUND OF WIDESPREAD SHOWERS
AND A FEW THUNDERSTORMS POSSIBLE.
THE MODELS HAVE BEEN VARYING WITH THE AMOUNT AND POSITION OF THE
HEAVIER QPF...WITH THE ECMWF AND NAM BEEFIER...WHILE THE GFS HAS
BEEN LEANER. GIVEN THE FACT THAT THERE IS WEAK MID AND UPPER LEVEL
FORCING...AM INCLINED TO PUT MORE CONFIDENCE IN THE LEANER TOTALS
FOR NOW. STILL...PWATS ARE EXTREMELY HIGH AND ANY TRAINING
THUNDERSTORM ACTIVITY COULD CERTAINLY BRING TOTALS MORE TOWARDS
THE HIGHER END...UPWARDS OF 2 INCHES IN A 6 TO 12 HOUR PERIOD.
CONSEQUENTLY...WILL CONTINUE TO MENTION GENERALIZED FLOODING
CONCERNS IN THE HWO.
FOR TEMPERATURES...A MORE DIURNALLY LIMITED REGIME WAS
FAVORED...GIVEN THE CLOUDS AND QUICK RETURN OF PRECIPITATION BY
CHRISTMAS DAY. HIGHS TODAY WILL RANGE FROM THE MID TO UPPER
60S...WITH READINGS MORE IN THE LOW TO MID 60S FOR THE HOLIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 359 AM EST THU DEC 24 2015
MODELS ARE IN GENERALLY GOOD AGREEMENT ON THE MILD AND WET PATTERN
PERSISTING THROUGH THE WEEKEND INTO NEXT WEEK. IT DOES LOOK LIKE THE
WARM FRONT SHOULD LIFT NORTH FRIDAY NIGHT INTO EARLY SATURDAY WITH
RAIN CHANCES LIFTING NORTH OF THE AREA. THUS...MUCH OF SATURDAY
COULD END UP ON THE DRIER SIDE (WHICH WOULD NOT BE A BAD THING). IF
THE DRIER FORECAST PANS OUT...TEMPERATURES COULD SOAR INTO THE LOW
TO MID 70S SOUTH OF THE WARM FRONT...SETTING UP ANOTHER RECORD
BREAKING DAY. IF CLOUDS HOLD ON OR PRECIPITATION HOLDS ON
LONGER...WE MIGHT HAVE TO SETTLE FOR READINGS CLOSER TO 70...BUT
STILL MILD. PRECIPITATION STAYS NORTH INTO SATURDAY NIGHT...BUT THE
FRONT WILL BE DRIVEN BACK TO THE SOUTH ON SUNDAY WITH RAIN CHANCES
RAMPING BACK UP. THE FRONT WILL THEN STALL IN OUR VICINITY KEEPING
THE WEATHER UNSETTLED INTO MONDAY. FINALLY A COLD FRONT SHOULD SWEEP
ACROSS THE AREA MONDAY NIGHT/TUESDAY...BRINGING AN END TO THE
EXTENDED PERIOD OF WET AND MILD WEATHER. TEMPERATURES WILL TAKE A
HIT BY WEDNESDAY WITH HIGHS BACK INTO THE LOWER 50S (BUT STILL ABOVE
NORMAL!). A SECONDARY COLD FRONT COULD BRING A BETTER SURGE OF
COLDER AIR AS WE HEAD INTO NEW YEARS EVE...BRINGING A RETURN OF
MORE SEASONABLE WINTER WEATHER TO EASTERN KENTUCKY.
FORTUNATELY...DESPITE IT TURNING COLDER NEXT WEEK...STILL NO SIGNS
OF ANY SNOWFALL FOR OUR NECK OF THE WOODS.
WITH ALL THE RAIN EXPECTED ON FRIDAY/FRIDAY NIGHT...COUPLED WITH THE
RAIN SUNDAY INTO TUESDAY...WE WILL CONTINUE TO HAVE TO MONITOR
CONDITIONS FOR POSSIBLE FLOODING...ESPECIALLY ON THE RIVERS AND
CREEKS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 757 AM EST THU DEC 24 2015
MVFR CEILINGS SHOULD GRADUALLY RAISE UP TO VFR THROUGH THIS
MORNING AS A WEAK AREA OF HIGH PRESSURE BUILDS IN ACROSS THE OHIO
VALLEY. CEILINGS WILL THEN LOWER DOWN TO MVFR LATER TONIGHT AND
THEN IFR THROUGH THE END OF THE PERIOD. RAIN SHOWERS WILL BE
MOVING BACK IN BY CHRISTMAS DAY. WINDS WILL AVERAGE AROUND 5 KTS
OR LESS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GEOGERIAN
LONG TERM...KAS
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1124 AM EST THU DEC 24 2015
.SYNOPSIS...
A WARM FRONT WILL MOVE THROUGH THE AREA THIS AFTERNOON WITH
STRONG WARM AIR ADVECTION. THIS WILL SET THE STAGE FOR SEVERAL
RECORD HIGH TEMPERATURES TO BE BROKEN...ESPECIALLY ACROSS SOUTHERN
NEW HAMPSHIRE AND EXTREME SOUTHWEST MAINE. A WEAK COLD FRONT MOVES
ACROSS THE AREA TONIGHT WITH CLEARING CONDITIONS AND COOLER
TEMPERATURES. TEMPERATURES WILL STILL REMAIN WELL ABOVE NORMAL FOR
TONIGHT AND CHRISTMAS DAY. OUR NEXT STORM SYSTEM LOOKS TO ARRIVE
LATE SATURDAY INTO SUNDAY AND SHOULD BE MOSTLY IN THE FORM OF RAIN
ONCE AGAIN. HOWEVER...COLDER AIR WILL PUSH INTO THE REGION THE
BEGINNING OF NEXT WEEK AND COULD REMAIN IN PLACE LONG ENOUGH FOR
SEVERAL LOCATIONS TO SEE THEIR FIRST MEASURABLE SNOWFALL OF THE
SEASON TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1120 AM UPDATE...
WARM FRONT HAS PUSHED INLAND A WAYS...BRINGING PATCHY FOG AND
DRIZZLE WITH IT. TO THE WEST A QLCS HAD DEVELOPED ALONG A COLD
FRONT WITH SOME SHOWERS OUT AHEAD OF IT. THE FRONT LOOKS NOW TO
CROSS THE AREA EARLY THIS EVENING WITH LITTLE FANFARE.
TEMPERATURES WILL CONTINUE TO BE TRICKY WITH POSSIBLE RAPID
WARMING TOWARDS THE END OF THE DAY ONCE THE INVERSION BREAKS.
9 AM UPDATE...
DIURNAL CURVE REMAINS A CHALLENGE WITH WARM FRONT SNAKING THROUGH
THE REGION AND ALONG THE COAST. PLENTY OF MOISTURE IS POOLING IN
THE WARM SECTOR WITH TEMPERATURES IN OUR AREA IN THE LOW TO MID
40S. FARTHER SOUTH FROM ALBANY TO CAPE COD READINGS ARE IN THE LOW
60S. AS THE WARM FRONT LIFTS NORTH AND EAST WE WILL SEE THAT
WARMTH SPREAD NORTH AND EAST...HOWEVER IT MAY TAKE MOST OF THE
DAY FOR PORTIONS OF THE AREA. IN FACT IT MAY BE AFTER SUNSET THAT
SOME LOCATIONS REACH THEIR HIGHS...INCLUDING PORTLAND.
MANCHESTER AND NASHUA SHOULD REACH THEM MUCH SOONER.
A STRONG AND SHALLOW INVERSION IS NOTED ON THIS MORNING`S
SOUNDING AND IS RESPONSIBLE FOR KEEPING THE WARMER TEMPERATURES
JUST ALOFT. FOR INSTANCE MT WASHINGTON ALREADY BROKE THEIR
TEMPERATURE RECORD FOR THE DAY.
WENT CLOSE TO THE 11Z HRRR FOR THE DIURNAL CURVE WHICH HAS A
BETTER HANDLE ON THE TEMPERATURES THAN THE LATER RUNS AND THE
LOCAL WRF. DRIZZLE/FOG CONTINUES FOR A FEW MORE HOURS UNTIL THE
INVERSION CAN BE BROKEN/ERODED. THERE IS A STRONG LLJ (45 KT)
JUST OFF THE DECK AT AROUND FL025 KFT.
SOME FUN CHRISTMAS EVE WEATHER TRIVIA...THIS MORNING`S KGYX
SOUNDING HAD +13 DEGREES C AT 850MB TEMPERATURE...WHICH IS OUR
SECOND ALL TIME HIGHEST 850MB TEMPERATURE FOR DECEMBER. GOING UP
TO 700MB WE ARE +9 C WHICH IS THE HIGHEST EVER RECORDED FOR
NOVEMBER OR DECEMBER. FOR INSTANCE...KEY WEST`S SOUNDING THIS
MORNING WAS ONLY ONE DEGREE HIGHER (+10) AT 700MB THAN WE ARE!
PREVIOUS DISCUSSION...
WITH THE RAIN ENDING BY MORNING AS THE WARM FRONT ALOFT PASSES TO
OUR N...THE NEXT PROBLEM WILL BE DEALING WITH THE SHARP INVERSIONS
OVER THE AREA THAT BUFKIT SHOWS REMAINING IN PLACE AT ALL
LOCATIONS INTO THE EARLY AFTERNOON. THE SURFACE ANALYSIS ALREADY
SHOWS NICE LOW LEVEL DAMMING OCCURRING WITH NOSING OF HIGH
PRESSURE EXTENDING SOUTHWEST ACROSS ME AND NH. MODELS ARE ALL IN
AGREEMENT THE LOW LEVEL SOUTHWEST JET WILL BE RIDING OVER THIS
SHALLOW INVERSION INTO THE AFTERNOON. WITH THE LACK OF VENTILATION
OF ALL THE RESIDUAL MOISTURE COMBINING WITH STRONG WAA ABOVE THE
SURFACE..WILL EXPECT SUPERSATURATION OF THE AIR MASS TO REMAIN AND
FOG AND DRIZZLE TO REFORM IN THE MORNING...THE QUESTION WILL BE
HOW LOW VISIBILITIES WILL GO. THE DAY SHIFT WILL HAVE TO WATCH FOR
A POSSIBLE NEED OF A DENSE FOG ADVISORY IN SOME AREAS FOR A WHILE
INTO EARLY AFTERNOON. STILL CONFIDENT TEMPERATURES ARE EXPECTED TO
REACH RECORD HIGHS OVER SOUTHERN NH AND SOUTHWEST ME BUT WILL NOT
BE REALIZED UNTIL MID- LATE AFTERNOON AS THE INVERSIONS BREAK AND
A SUDDEN JUMP IN TEMPS WILL BE NOTED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
A WEAK COLD FRONT WITH NOT MUCH COLD AIR IN ITS WAKE MOVES
THROUGH THE REGION TONIGHT ALLOWING CLEARING SKIES TO OCCUR AND
TEMPS TO COOL. EVEN STILL TEMPS WILL REMAIN WELL ABOVE NORMAL
TONIGHT AND CHRISTMAS DAY. USED A BLEND OF MODELS FOR MIN/MAX TEMP
FORECAST TONIGHT AND FRI.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRES SLIDES EWD THRU THE REGION FRI NIGHT. LOW TEMPS WILL
DEPEND ON THE AMOUNT OF CLOUD COVER THAT CAN MAKE IT INTO SRN
ZONES. EXPECT THAT MOST OF SAT WILL BE DRY...UNTIL THE EVE. S/WV
TROF MOVING THRU THE GREAT LAKES WILL INDUCE A WEAK LOW TO FORM
ALONG THE STALLED FRONTAL BOUNDARY TO OUR S. THIS WAVE WILL SPREAD
PRECIP INTO THE AREA FROM THE W SAT NIGHT. THERE IS NOT A LOT OF
COLD AIR AROUND FOR THIS SYSTEM...BUT DRY AIR ALOFT MAY ALLOW FOR
ENOUGH WET BULB COOLING TO BRING A MIX OR SNWFL INTO NRN ZONES.
WILL USE A TOP DOWN APPROACH TO PRECIP TYPE IN THOSE AREAS...TO
INTRODUCE A LITTLE WINTRY MIX. THIS IS STILL NEARLY 4 DAYS
OUT...SO DETAILS CAN CHANGE...BUT A LIGHT SNWFL IS POSSIBLE FOR
THE FAR N NEAR JACKMAN...WHILE THRU THE MTNS A LIGHT FREEZING RA
IS POSSIBLE.
BEHIND THIS SYSTEM...A SECONDARY S/WV WILL DRIVE A STRONG COLD
FRONT THRU THE REGION. FOR WHAT SEEMS LIKE THE FIRST TIME IN A
LONG WHILE MODEL GUIDANCE IS INDICATING A SEASONABLY COLD AIR
MASS. THAT/S RIGHT...BELOW NORMAL TEMPS ALOFT. SFC HIGH PRES THAT
BUILDS IN WITH THESE TEMPS IS ALSO FORECAST TO BE QUITE STRONG ON
BOTH GEFS AND ECMWF EPS. MODEL TIMING IS IN EXCELLENT AGREEMENT
FOR THIS RANGE...ARRIVING AROUND 18Z TUE...SO I HAVE NO PROBLEM
GOING WITH LIKELY POP. WITHOUT GETTING INTO TOO MUCH DETAIL FOR
DAY 6...CAREFUL EXAMINATION OF TEMP TRENDS ALOFT SHOW A PRETTY
CLASSIC SIGNAL FOR SNWFL TO MIX FOR A LARGE PART OF THE REGION.
HIGH HEIGHTS IN THE E IS THE TENDENCY STILL IN THE MID
LEVELS...AND THAT WILL WANT TO SEND ANY SYSTEM TO OUR W. THE
RESULTING WAA OVERHEAD WILL BRING IN WARMTH FROM THE SW. ALL MODEL
GUIDANCE SHOWS THIS EVOLUTION...WITH THE GFS AND ECMWF IN CLOSER
AGREEMENT THAN THE COLDER CMC. AGAIN...THIS SYSTEM IS TOO FAR OUT
TO START HAMMERING OUT EXACT SNWFL AMOUNTS...BUT THE CHANCES FOR A
MEASURABLE SNWFL ARE GROWING AND BECOMING MORE LIKELY. ANOTHER 24
HOURS AND THIS SYSTEM WILL BE CLOSER TO THE RANGE WHERE MEDIUM
RANGE GUIDANCE HISTORICALLY STARTS TO PERFORM WELL.
ONE THING THAT IS HIGHER CONFIDENCE IS THAT WITH STRONG HIGH PRES
AND PRECIP MOVING IN...COLD AIR DAMMING WILL KEEP TEMPS ON THE
COOL SIDE. MULTI-MODEL CONSENSUS IS ALREADY KEYING ON THIS AND
DROPPED THE PREVIOUS FORECAST BY SEVERAL DEGREES WHEN BLENDED IN.
IF SECONDARY LOW PRES DEVELOPS AS SUGGESTS BY OPERATIONAL AND
ENSEMBLE GUIDANCE...THESE COOLER SFC TEMPS COULD CONTINUE INTO
WED WITH THE COASTAL FRONT TUCKING BACK IN BEHIND IT.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
SHORT TERM...IFR CONDITIONS IN LOW STRATUS AND AREAS OF FOG AND
DRIZZLE WILL CONTINUE THROUGH THE MORNING AND INTO THE AFTERNOON
AS SHARP SURFACE INVERSIONS REMAIN IN PLACE. LLWS WILL ALSO BE A
CONCERN DUE TO A RATHER STRONG LOW LEVEL JET ABOVE THE INVERSION
THROUGH MUCH OF THE DAY. BY MID TO LATE AFTERNOON ENOUGH MIXING
OCCURS TO SCOUR OUT THE INVERSIONS AND CONDITIONS TO IMPROVE TO
VFR AS WINDS ALSO SHIFT TO THE WEST. TONIGHT AND FRIDAY CONDITIONS
WILL BE VFR.
LONG TERM...VFR TO BEGIN THE PERIOD AS HIGH PRES IS IN CONTROL OF
THE REGION. CLOUDS INCREASE FROM THE W LATE SAT...WITH AREAS OF
MVFR AND LOCAL IFR DEVELOPING OVERNIGHT. EXPECTING MAINLY -RA FOR
ALL TERMINALS...THOUGH A LITTLE MIX MAY DEVELOP NEAR HIE
OVERNIGHT SAT. VFR RETURNS SUN EVE AS STRONG HIGH PRES MOVES INTO
THE AREA THRU MON.
&&
.MARINE...
SHORT TERM...A SCA WILL REMAIN IN PLACE AND WILL BE EXTENDED TO
FRIDAY MORNING OVER THE OUTER WATERS DUE TO FIRST WINDS AND SEAS
AND THEN JUST HAZ SEAS AS WINDS SHIFT TO THE WEST AND BECOME
LIGHT. THE SCA OVER PENOBSCOT BAY WILL BE DROPPED AND THE SCA OVER
CASCO BAY WILL BE FOR HAZ SEAS UNTIL 1 PM.
LONG TERM...WINDS AND SEAS LOOK TO REMAIN BELOW SCA THRESHOLDS
UNTIL EARLY NEXT WEEK WHEN STRONG HIGH PRES MOVES TOWARDS THE
WATERS. THE ACCOMPANYING NWLY CAA WILL MOST LIKELY BRING WINDS AND
SEAS TO SCA CONDITIONS. WEAK LOW PRES DEVELOPING IN THE GULF OF ME
TUE MAY EXTEND SCA CONDITIONS INTO MIDWEEK.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 1 PM EST THIS
AFTERNOON FOR ANZ153.
SMALL CRAFT ADVISORY UNTIL 7 AM EST FRIDAY FOR ANZ150-152-154.
&&
$$
NEAR TERM...HANES
SHORT TERM...MARINE
LONG TERM...LEGRO
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
923 AM EST THU DEC 24 2015
.SYNOPSIS...
A WARM FRONT WILL MOVE THROUGH THE AREA THIS AFTERNOON WITH
STRONG WARM AIR ADVECTION. THIS WILL SET THE STAGE FOR SEVERAL
RECORD HIGH TEMPERATURES TO BE BROKEN...ESPECIALLY ACROSS SOUTHERN
NEW HAMPSHIRE AND EXTREME SOUTHWEST MAINE. A WEAK COLD FRONT MOVES
ACROSS THE AREA TONIGHT WITH CLEARING CONDITIONS AND COOLER
TEMPERATURES. TEMPERATURES WILL STILL REMAIN WELL ABOVE NORMAL FOR
TONIGHT AND CHRISTMAS DAY. OUR NEXT STORM SYSTEM LOOKS TO ARRIVE
LATE SATURDAY INTO SUNDAY AND SHOULD BE MOSTLY IN THE FORM OF RAIN
ONCE AGAIN. HOWEVER...COLDER AIR WILL PUSH INTO THE REGION THE
BEGINNING OF NEXT WEEK AND COULD REMAIN IN PLACE LONG ENOUGH FOR
SEVERAL LOCATIONS TO SEE THEIR FIRST MEASURABLE SNOWFALL OF THE
SEASON TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
9 AM UPDATE...
DIURNAL CURVE REMAINS A CHALLENGE WITH WARM FRONT SNAKING THROUGH
THE REGION AND ALONG THE COAST. PLENTY OF MOISTURE IS POOLING IN
THE WARM SECTOR WITH TEMPERATURES IN OUR AREA IN THE LOW TO MID
40S. FARTHER SOUTH FROM ALBANY TO CAPE COD READINGS ARE IN THE LOW
60S. AS THE WARM FRONT LIFTS NORTH AND EAST WE WILL SEE THAT
WARMTH SPREAD NORTH AND EAST...HOWEVER IT MAY TAKE MOST OF THE
DAY FOR PORTIONS OF THE AREA. IN FACT IT MAY BE AFTER SUNSET THAT
SOME LOCATIONS REACH THEIR HIGHS...INCLUDING PORTLAND.
MANCHESTER AND NASHUA SHOULD REACH THEM MUCH SOONER.
A STRONG AND SHALLOW INVERSION IS NOTED ON THIS MORNING`S
SOUNDING AND IS RESPONSIBLE FOR KEEPING THE WARMER TEMPERATURES
JUST ALOFT. FOR INSTANCE MT WASHINGTON ALREADY BROKE THEIR
TEMPERATURE RECORD FOR THE DAY.
WENT CLOSE TO THE 11Z HRRR FOR THE DIURNAL CURVE WHICH HAS A
BETTER HANDLE ON THE TEMPERATURES THAN THE LATER RUNS AND THE
LOCAL WRF. DRIZZLE/FOG CONTINUES FOR A FEW MORE HOURS UNTIL THE
INVERSION CAN BE BROKEN/ERODED. THERE IS A STRONG LLJ (45 KT)
JUST OFF THE DECK AT AROUND FL025 KFT.
SOME FUN CHRISTMAS EVE WEATHER TRIVIA...THIS MORNING`S KGYX
SOUNDING HAD +13 DEGREES C AT 850MB TEMPERATURE...WHICH IS OUR
SECOND ALL TIME HIGHEST 850MB TEMPERATURE FOR DECEMBER. GOING UP
TO 700MB WE ARE +9 C WHICH IS THE HIGHEST EVER RECORDED FOR
NOVEMBER OR DECEMBER. FOR INSTANCE...KEY WEST`S SOUNDING THIS
MORNING WAS ONLY ONE DEGREE HIGHER (+10) AT 700MB THAN WE ARE!
PREVIOUS DISCUSSION...
WITH THE RAIN ENDING BY MORNING AS THE WARM FRONT ALOFT PASSES TO
OUR N...THE NEXT PROBLEM WILL BE DEALING WITH THE SHARP INVERSIONS
OVER THE AREA THAT BUFKIT SHOWS REMAINING IN PLACE AT ALL
LOCATIONS INTO THE EARLY AFTERNOON. THE SURFACE ANALYSIS ALREADY
SHOWS NICE LOW LEVEL DAMMING OCCURRING WITH NOSING OF HIGH
PRESSURE EXTENDING SOUTHWEST ACROSS ME AND NH. MODELS ARE ALL IN
AGREEMENT THE LOW LEVEL SOUTHWEST JET WILL BE RIDING OVER THIS
SHALLOW INVERSION INTO THE AFTERNOON. WITH THE LACK OF VENTILATION
OF ALL THE RESIDUAL MOISTURE COMBINING WITH STRONG WAA ABOVE THE
SURFACE..WILL EXPECT SUPERSATURATION OF THE AIR MASS TO REMAIN AND
FOG AND DRIZZLE TO REFORM IN THE MORNING...THE QUESTION WILL BE
HOW LOW VISIBILITIES WILL GO. THE DAY SHIFT WILL HAVE TO WATCH FOR
A POSSIBLE NEED OF A DENSE FOG ADVISORY IN SOME AREAS FOR A WHILE
INTO EARLY AFTERNOON. STILL CONFIDENT TEMPERATURES ARE EXPECTED TO
REACH RECORD HIGHS OVER SOUTHERN NH AND SOUTHWEST ME BUT WILL NOT
BE REALIZED UNTIL MID- LATE AFTERNOON AS THE INVERSIONS BREAK AND
A SUDDEN JUMP IN TEMPS WILL BE NOTED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
A WEAK COLD FRONT WITH NOT MUCH COLD AIR IN ITS WAKE MOVES
THROUGH THE REGION TONIGHT ALLOWING CLEARING SKIES TO OCCUR AND
TEMPS TO COOL. EVEN STILL TEMPS WILL REMAIN WELL ABOVE NORMAL
TONIGHT AND CHRISTMAS DAY. USED A BLEND OF MODELS FOR MIN/MAX TEMP
FORECAST TONIGHT AND FRI.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRES SLIDES EWD THRU THE REGION FRI NIGHT. LOW TEMPS WILL
DEPEND ON THE AMOUNT OF CLOUD COVER THAT CAN MAKE IT INTO SRN
ZONES. EXPECT THAT MOST OF SAT WILL BE DRY...UNTIL THE EVE. S/WV
TROF MOVING THRU THE GREAT LAKES WILL INDUCE A WEAK LOW TO FORM
ALONG THE STALLED FRONTAL BOUNDARY TO OUR S. THIS WAVE WILL SPREAD
PRECIP INTO THE AREA FROM THE W SAT NIGHT. THERE IS NOT A LOT OF
COLD AIR AROUND FOR THIS SYSTEM...BUT DRY AIR ALOFT MAY ALLOW FOR
ENOUGH WET BULB COOLING TO BRING A MIX OR SNWFL INTO NRN ZONES.
WILL USE A TOP DOWN APPROACH TO PRECIP TYPE IN THOSE AREAS...TO
INTRODUCE A LITTLE WINTRY MIX. THIS IS STILL NEARLY 4 DAYS
OUT...SO DETAILS CAN CHANGE...BUT A LIGHT SNWFL IS POSSIBLE FOR
THE FAR N NEAR JACKMAN...WHILE THRU THE MTNS A LIGHT FREEZING RA
IS POSSIBLE.
BEHIND THIS SYSTEM...A SECONDARY S/WV WILL DRIVE A STRONG COLD
FRONT THRU THE REGION. FOR WHAT SEEMS LIKE THE FIRST TIME IN A
LONG WHILE MODEL GUIDANCE IS INDICATING A SEASONABLY COLD AIR
MASS. THAT/S RIGHT...BELOW NORMAL TEMPS ALOFT. SFC HIGH PRES THAT
BUILDS IN WITH THESE TEMPS IS ALSO FORECAST TO BE QUITE STRONG ON
BOTH GEFS AND ECMWF EPS. MODEL TIMING IS IN EXCELLENT AGREEMENT
FOR THIS RANGE...ARRIVING AROUND 18Z TUE...SO I HAVE NO PROBLEM
GOING WITH LIKELY POP. WITHOUT GETTING INTO TOO MUCH DETAIL FOR
DAY 6...CAREFUL EXAMINATION OF TEMP TRENDS ALOFT SHOW A PRETTY
CLASSIC SIGNAL FOR SNWFL TO MIX FOR A LARGE PART OF THE REGION.
HIGH HEIGHTS IN THE E IS THE TENDENCY STILL IN THE MID
LEVELS...AND THAT WILL WANT TO SEND ANY SYSTEM TO OUR W. THE
RESULTING WAA OVERHEAD WILL BRING IN WARMTH FROM THE SW. ALL MODEL
GUIDANCE SHOWS THIS EVOLUTION...WITH THE GFS AND ECMWF IN CLOSER
AGREEMENT THAN THE COLDER CMC. AGAIN...THIS SYSTEM IS TOO FAR OUT
TO START HAMMERING OUT EXACT SNWFL AMOUNTS...BUT THE CHANCES FOR A
MEASURABLE SNWFL ARE GROWING AND BECOMING MORE LIKELY. ANOTHER 24
HOURS AND THIS SYSTEM WILL BE CLOSER TO THE RANGE WHERE MEDIUM
RANGE GUIDANCE HISTORICALLY STARTS TO PERFORM WELL.
ONE THING THAT IS HIGHER CONFIDENCE IS THAT WITH STRONG HIGH PRES
AND PRECIP MOVING IN...COLD AIR DAMMING WILL KEEP TEMPS ON THE
COOL SIDE. MULTI-MODEL CONSENSUS IS ALREADY KEYING ON THIS AND
DROPPED THE PREVIOUS FORECAST BY SEVERAL DEGREES WHEN BLENDED IN.
IF SECONDARY LOW PRES DEVELOPS AS SUGGESTS BY OPERATIONAL AND
ENSEMBLE GUIDANCE...THESE COOLER SFC TEMPS COULD CONTINUE INTO
WED WITH THE COASTAL FRONT TUCKING BACK IN BEHIND IT.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
SHORT TERM...IFR CONDITIONS IN LOW STRATUS AND AREAS OF FOG AND
DRIZZLE WILL CONTINUE THROUGH THE MORNING AND INTO THE AFTERNOON
AS SHARP SURFACE INVERSIONS REMAIN IN PLACE. LLWS WILL ALSO BE A
CONCERN DUE TO A RATHER STRONG LOW LEVEL JET ABOVE THE INVERSION
THROUGH MUCH OF THE DAY. BY MID TO LATE AFTERNOON ENOUGH MIXING
OCCURS TO SCOUR OUT THE INVERSIONS AND CONDITIONS TO IMPROVE TO
VFR AS WINDS ALSO SHIFT TO THE WEST. TONIGHT AND FRIDAY CONDITIONS
WILL BE VFR.
LONG TERM...VFR TO BEGIN THE PERIOD AS HIGH PRES IS IN CONTROL OF
THE REGION. CLOUDS INCREASE FROM THE W LATE SAT...WITH AREAS OF
MVFR AND LOCAL IFR DEVELOPING OVERNIGHT. EXPECTING MAINLY -RA FOR
ALL TERMINALS...THOUGH A LITTLE MIX MAY DEVELOP NEAR HIE
OVERNIGHT SAT. VFR RETURNS SUN EVE AS STRONG HIGH PRES MOVES INTO
THE AREA THRU MON.
&&
.MARINE...
SHORT TERM...A SCA WILL REMAIN IN PLACE AND WILL BE EXTENDED TO
FRIDAY MORNING OVER THE OUTER WATERS DUE TO FIRST WINDS AND SEAS
AND THEN JUST HAZ SEAS AS WINDS SHIFT TO THE WEST AND BECOME
LIGHT. THE SCA OVER PENOBSCOT BAY WILL BE DROPPED AND THE SCA OVER
CASCO BAY WILL BE FOR HAZ SEAS UNTIL 1 PM.
LONG TERM...WINDS AND SEAS LOOK TO REMAIN BELOW SCA THRESHOLDS
UNTIL EARLY NEXT WEEK WHEN STRONG HIGH PRES MOVES TOWARDS THE
WATERS. THE ACCOMPANYING NWLY CAA WILL MOST LIKELY BRING WINDS AND
SEAS TO SCA CONDITIONS. WEAK LOW PRES DEVELOPING IN THE GULF OF ME
TUE MAY EXTEND SCA CONDITIONS INTO MIDWEEK.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 1 PM EST THIS
AFTERNOON FOR ANZ153.
SMALL CRAFT ADVISORY UNTIL 7 AM EST FRIDAY FOR ANZ150-152-154.
&&
$$
NEAR TERM...HANES
SHORT TERM...MARINE
LONG TERM...LEGRO
AREA FORECAST DISCUSSION
NWS CARIBOU ME
555 AM EST THU DEC 24 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK TO OUR NORTHWEST TODAY PULLING A WARM
FRONT THROUGH THE REGION. A COLD FRONT WILL CROSS THE AREA LATE
TODAY THEN HIGH PRESSURE WILL BUILD IN FROM THE WEST CHRISTMAS
DAY INTO SATURDAY. LOW PRESSURE FROM THE MIDWEST WILL APPROACH
ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
545 AM UPDATE...THE LATEST HI-RES MODELS, INCLUDING THE RUC AND
HRRR, AS WELL AS THE NAM AND GFS, HAVE ALL BACKED OFF A BIT ON
TODAY`S WARMING. NORTHEASTERN MAINE IN PARTICULARLY IS LOOKING A
LITTLE COOLER THAN THE PREVIOUS FORECAST; NOTE THE RUC BARELY
BRINGS CAR AND PQI UP TO 40 DEGREES BY AFTERNOON. THIS IS LIKELY
TOO PESSIMISTIC, THOUGH THE WARMEST AIR WILL REMAIN TO OUR SOUTH.
HAVE LOWERED HIGH TEMPERATURES TODAY BY JUST A COUPLE OF DEGREES,
ESPECIALLY IN AROOSTOOK COUNTY AND PORTIONS OF THE CENTRAL
HIGHLANDS. THE CLIMATE SECTION HAS BEEN UPDATED WITH THE LATEST
FORECAST. ALSO LOWERED POPS A BIT THROUGH THIS AFTERNOON AS
SHOWERS DON`T LOOK TO BE AS WIDESPREAD AS PREVIOUSLY ANTICIPATED.
PREVIOUS DISCUSSION...A WARM FRONT CURRENTLY DRAPED ACROSS
EASTERN NEW YORK AND WESTERN NEW ENGLAND WILL CONTINUE TO LIFT
NORTH AND EAST THIS MORNING. WIDESPREAD RAIN WILL ALSO CONTINUE
THROUGH THE MORNING HOURS, BUT IT SHOULD TAPER DOWN TO SCATTERED
SHOWERS BY AFTERNOON ONCE THE FRONT PASSES THROUGH THE STATE. THE
COLD FRONT WILL QUICKLY FOLLOW, CROSSING FROM WEST TO EAST LATE
THIS AFTERNOON. NOTE THAT MUCH OF THE GUIDANCE INDICATES THAT
THERE WILL BE SHOWER ACTIVITY WITH THE FRONTAL PASSAGE, BUT EXPECT
PRECIPITATION TO END FAIRLY RAPIDLY THEREAFTER. TEMPERATURES,
ALREADY QUITE MILD FOR LATE DECEMBER, WILL CONTINUE TO RISE
THROUGH THE DAY. EXPECT UPPER 40S ACROSS THE NORTH AND LOWER TO
MID 50S IN THE BANGOR REGION DOWN TO THE COAST. SEE THE CLIMATE
SECTION BELOW FOR ADDITIONAL INFORMATION. DRIER AND COOLER AIR
WILL SLOWLY WORK INTO THE FORECAST AREA OVERNIGHT BEHIND THE
AFOREMENTIONED COLD FRONT. EVEN STILL, TONIGHT`S LOWS WILL BE WELL
ABOVE NORMAL.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE SHORT TERM CONTS TO LOOK FAIR...BREEZY AND PROGRESSIVELY
COLDER AS SFC HI PRES APCHS FROM THE W AND CROSSES THE REGION...
ALBEIT TEMPS WILL STILL BE ABV AVG FOR THIS TM OF SEASON...EVEN
ON SAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE ONLY SIG CHG FOR THE LATE SAT NGT INTO SUN PRECIP EVENT IS
THAT OPNL MODELS HAVE TRENDED A LITTLE FURTHER S THAN YSTDY
ATTM...MEANING THAT MORE OF THE...NAMELY THE N AND PTNS OF E CNTRL
ME WILL HOLD ALL OR MSLY ALL SN WITH THIS EVENT. INTERIOR DOWNEAST
AND LOWER PENOBSCOT VLY LCTNS WILL LIKELY HAVE A MIX OF SN...PL
AND RN WITH THIS EVENT WHILE COASTAL AREAS RECEIVE MSLY RN AFT A A
RELATIVELY BRIEF START OF MIXED PRECIP. TOTAL STORM TOTAL QPF
STILL SUGGESTS THAT THIS EVENT WILL LIKELY BE AN ADV LVL EVENT...
ALTHOUGH LOW END WRNG CRITERIA SNFL COULD NOT BE RULED FOR SOME
LCTNS IF THE EVENTS CONTS A FEW HRS INTO SUN EVE BEFORE TAPERING
TO SN SHWRS. WE CONTD TO RAISE MAX POPS INTO THE CATEGORICAL RANGE
FOR THIS EVENT GIVEN RELATIVE MODEL CONSISTENCY OF SHOWING SIG
QPF.
FOLLOWING THE LOW AS IT MOVES E ACROSS NOVA SCOTIA...AN ARCTIC
FRONT AND UPPER LVL TROF FROM HUDSON BAY WILL BRING CLDY SKIES AND
SN SHWRS SPCLY TO THE N HLF OF THE FA LATE SUN NGT INTO ERLY MON
MORN...WITH SKIES BECOMING PTLY CLDY N AND MSLY SUNNY S BY MON
AFTN. AFT NEAR AVG OVRNGT LOWS...HI TEMPS MON LOOK TO BE A LITTLE
BLO AVG WITH A BRISK NW WIND. WINDS WILL DIMINISH MON EVE AND AND
BECOME LGT AND VRBL LATE MON NGT AS SKIES REMAIN MSLY CLR WITH THE
SFC HI PRES CROSSING THE REGION. THIS WILL LIKELY RESULT IN THE
COLDEST NGT OF THE WINTER SO FAR...WITH MANY LCTNS ACROSS THE
N...SPCLY THOSE IN BROAD RVR VLYS FALLING INTO THE SINGLE DIGITS
BELOW ZERO.
ANOTHER S/WV AND SFC LOW APCHG FROM THE MIDWEST WILL BRING
INCREASING CLDNSS TO THE REGION ON TUE WITH SN SLOWLY SPREADING SW
TO NE ACROSS THE REGION FROM TUE AFTN INTO TUE NGT. WITH THE TRACK
OF THE SFC LOW SHOWN TO BE FURTHER S THAN THE MODELS DID YSTDY...
THE CONSENSUS OF MOST MODELS ATTM IS THAT THE BEST POTENTIAL OF
QPF WITH THIS EVENT WILL BE OVR THE S HLF OF THE FA...WHERE WE
WEIGHT HIGHEST POPS IN THE LIKELY CATEGORY WITH HI CHC POPS ACROSS
THE N. FOLLOWING THIS SYSTEM FOR WED INTO WED NGT...BOTH THE 00Z
DTMNSTC GFS AND ECMWF SHOW SOME FOLLOW-UP S/WV ENERGY TRACKING OVR
THE FA FROM THE SW...SO WE MENTIONED LOW CHC SN SHWR POPS BOTH
PDS. TEMPS SHOULD SLOWLY MODERATE SOMEWHAT TUE THRU WED.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
NEAR TERM: WIDESPREAD IFR/LIFR CEILINGS WILL PREVAIL THROUGH 18Z
THIS AFTERNOON, ALONG WITH REDUCED VISIBILITY DUE TO RAIN AND FOG.
CONDITIONS WILL IMPROVE LATER THIS AFTERNOON FROM WEST TO EAST AS
A COLD FRONT CROSSES THE REGION. EXPECT ALL SITES TO BE VFR BY 04Z
FRIDAY.
SHORT TERM: VFR XPCTD FRI INTO SAT EVE...THEN CLGS AND VSBYS
LOWERING TO IFR ALL SITES OVRNGT SAT INTO SUN WITH SN FOR NRN
TAF SITES AND MIXED PRECIP FOR DOWNEAST SITES. CONDITIONS IMPROVE
TO MVFR FOR NRN TAF SITES SUN NGT WITH SCT SN SHWRS AND VFR
DOWNEAST. VFR WILL CONT SUN FOR DOWNEAST SITES WITH CONDITIONS
SLOWLY IMPROVING TO VFR NRN TAF SITES BY SUN AFTN.
&&
.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE INNER
WATERS UNTIL 9 AM, AND FOR THE OUTER WATERS UNTIL 6 PM. WINDS WILL
SUBSIDE THROUGH THE DAY, THOUGH SEAS WILL REMAIN ABOVE 5 FEET
THROUGH TONIGHT. THEREFORE THE CURRENT ADVISORY WILL LIKELY NEED TO
BE TRANSITIONED TO ONE FOR HAZARDOUS SEAS ONLY AT SOME POINT TODAY,
PARTICULARLY THE OUTER WATERS.
SHORT TERM: INITIALLY SCA SEAS FOR MSLY THE OUTER WATERS FOR FRI
MORN...WITH WV HTS SUBSIDING TO BLO SCA FRI AFTN. NO HDLNS LIKELY
NEEDED FOR FRI NGT AND SAT...WITH WINDS AND SEAS INCREASING TO SCA
BEHIND LOW PRES FOR ALL OF OUR MZS SUN NGT INTO MON.
&&
.CLIMATE...
THE RECORD HIGH TEMPERATURES FOR DECEMBER 24 ARE AS
FOLLOWS:
SITE RECORD HIGH YEAR CURRENT FORECAST
BANGOR 56 2003 55
CARIBOU 48 2003/2004 46
HOULTON 54 2004 48
MILLINOCKET 58 1911 50
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR ANZ052.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ050-
051.
&&
$$
NEAR TERM...HASTINGS
SHORT TERM...VJN
LONG TERM...VJN
AVIATION...HASTINGS/VJN
MARINE...HASTINGS/VJN
CLIMATE...
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1056 AM EST THU DEC 24 2015
.SYNOPSIS...
A COLD FRONT MOVES INTO THE REGION TODAY...REMAINING IN THE
VICINITY THROUGH THE WEEKEND AND INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM...APPROACHING COLD FRONT WAS IN WEST VIRGINIA. THE
FRONT IS PROGGED TO REACH DC METRO THIS AFTERNOON AND THEN SLOW
DOWN CONSIDERABLY WHILE BECOMING ORIENTED MORE EAST-WEST VERSUS
ITS CURRENT RATHER NORTH-SOUTH ORIENTATION. AS THIS
HAPPENS...THERE IS POTENTIAL FOR CONVECTION TO DEVELOP AND TRAVEL
PARALLEL TO THE FRONT...RESULTING IN A FLASH FLOOD RISK. THIS RISK
IS ENHANCED BY THE EXCEPTIONALLY HIGH PW AIR IN PLACE AT
PRESENT...THOUGH READINGS HAVE DIMINISHED A BIT FROM THEIR RECORD
VALUES LAST EVENING. FLASH FLOOD WATCH REMAINS IN EFFECT INTO THIS
EVENING.
OTHER CONCERN IS FOR ISOLATED SEVERE CONVECTION. THERE REMAINS
PLENTY OF WIND NOT FAR ABOVE THE SURFACE...SO ANY DOWNDRAFTS COULD
BRING STRONG GUSTS TO THE SURFACE. THE ISSUE IS LIMITED
CAPE...WHICH WILL KEEP DOWNDRAFTS FROM BECOMING VERY STRONG. THAT
SAID...ITS HARD TO IGNORE 40 KTS AT 850 AND 50+ AT 700. MARGINAL
RISK FROM SPC REMAINS IN PLACE.
ALL THAT HAVING BEEN SAID...SOME OF THE SHORT TERM MODELING SUCH
AS THE HRRR ARE BEGINNING TO SUGGEST THAT CONVECTION HAS NOW
PERMANENTLY SHIFTED SOUTHEAST OF THE DC/BALTIMORE METRO AREAS FOR
THE DURATION. IF WE BECOME MORE CONFIDENT IN THIS...ITS POSSIBLE
WE MAY DROP THE FLASH FLOOD WATCH...BUT AT THIS POINT CONFIDENCE
IS NOT HIGH.
NOT TO BE OVERSHADOWED BY THE OTHER CONCERNS FOR TODAY...RECORD
BREAKING TEMPERATURES ARE ONGOING TODAY WITH HIGHS PUSHING INTO
THE 70S. DID SIDE WITH A SLIGHTLY COOLER GUIDANCE WITH CLOUD COVER
AND PCPN EXPECTED THROUGH MOST...IF NOT ALL OF THE DAY. SO COULD
SEE TEMPS A FEW DEGREES WARMER IF SOME BREAKS OCCUR THIS AFTN.
ALL-TIME DECEMBER HIGHS LOOK OUT OF REACH...BUT ALL-TIME DECEMBER
MIN TEMPS ARE STILL QUITE POSSIBLE...PARTICULARLY AT DCA WHERE IT
IS ONLY 59. READINGS ARE LIKELY TO REMAIN IN THE 60S IN THE METRO
THROUGH MIDNIGHT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
FRONT LIKELY TO SLIDE SOUTH ACROSS THE AREA ON FRIDAY. AIR MASS
BEHIND IT IS NOT IMMEDIATELY MUCH COLDER BUT SOME COOLER READINGS
APPEAR LIKELY AND WITH PLENTY OF CLOUD COVER ITS POSSIBLE WE
ACTUALLY STAY IN THE 60S. ANOTHER WAVE RIDES EAST FRIDAY NIGHT
WITH ANOTHER SHOT AT RAIN.
HIGH PRESSURE QUICKLY TRANSITIONS FROM THE GL TO NE FOR
SAT...RESULTING IN AN ELY FLOW DURING THE DAY. LOOKS LIKE THIS
WILL SHOVE THE SURFACE BOUNDARY TO OUR SOUTH AND ERLY FLOW NORTH
OF IT WILL KEEP TEMPS ON THE COOLER SIDE...THOUGH STILL VERY MUCH
ABV NORMAL. FEELING THAT TEMPS ON SAT COULD HAVE BUST POTENTIAL
WITH SO MUCH UNCERTAINTY ON EXACTLY WHERE THE BOUNDARY SETS
UP...SO LOW CONFIDENCE FOR TEMPS...WITH HIGHER CONFIDENCE THOUGH
OF PCPN OCCURRING (ALL RAIN).
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
BROAD ERN CONUS RDG REMAINS THRU THE XTNDD FCST...ALTHO THE AXIS
PROGGED TO BE SHUNTED A BIT INTO THE ATLC AS WEST COAST ENERGY
EJECTS ACRS THE CONUS. THERE ARE MANY UNRESOLVED FINE-SCALE DETAILS
LEADING INTO THE XTNDD. THUS...AM TAKING A BIG-PICTURE STANDPOINT...
UNDERSTANDING THIS SOLN LKLY TO CHG.
REGARDLESS...SUN LKLY TO BE ANOTHER VERY WARM DAY. CDFNT WL THEN
COME THRU...BRINGING NEAR NORMAL TEMPS TO THE AREA SUN NGT/MON--
SOMETHING WHICH HAS BEEN ANYTHING BUT NORMAL RECENTLY. AM CARRYING
CHC POPS THRUT...THO IT/LL BE A TIMING/PLACEMENT ISSUE. SUSPECT
THERE WL BE A DRY PD POST-FROPA MON.
GFS/ECMWF BOTH SUGGEST THAT ANOTHER LOPRES WL EJECT FM THE SRN
PLAINS INTO THE GRTLKS TUE-WED. THAT WOULD BRING ANOTHER PAIR OF
FRONTS /WMFNT THEN CDFNT/ AND THEREFORE MORE PCPN CHCS. AT THIS
POINT AM KEEPING TEMPS ABV NORMAL BUT CLSR TO AVG THAN RECENT PAST.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
MVFR CIGS RETURNED THIS MORNING...BUT IMPROVE AGAIN THIS AFTN.
SHOWERS COULD BRING MOD-HEAVY RAIN AND BRIEF REDUCTIONS BACK TO
MVFR/IFR...ALONG WITH STRONG WINDS GUSTING 30-40 KTS. AN ISO TSTM
CANNOT BE RULED OUT EITHER.
LOW CONFIDENCE ON THE CONDITIONS TONIGHT WITH UNCERTAINTY ON WHERE
THE FRONT WILL END UP. RIGHT NOW GOING WITH MVFR VIS/IFR CIGS...BUT
COULD VERY WELL END UP SEEING EVEN LOWER. ANY PCPN SHOULD TAPER OFF
BY 03Z.
ANOTHER DAY OF SUB-VFR CONDITIONS AND RAIN FRIDAY WITH THE BOUNDARY
NEARBY. THESE CONDITIONS WILL CONTINUE INTO SAT. WINDS HOWEVER WILL
BE ON THE WEAKER SIDE...LESS THAN 10 KTS.
SUN-MON...CFP DURING THIS TIMEFRAME /MOST LKLY SUN PM/ WHICH WUD
BRING FLGT RESTRICTIONS. CONFIDENCE IN RESTRICTIONS OUTSIDE OF
THIS WINDOW LOW.
&&
.MARINE...
SCA CONDITIONS ON ALL WATERS TODAY. SMW MAY BE NEEDED THIS AFTN
WITH SHOWERS AND ISO TSTMS FORMING AHEAD OF AN APPROACHING FRONT.
BY TONIGHT...WINDS TAPER OFF GREATLY...WITH SCA GUSTS ONLY
PERSISTING ON THE CHESAPEAKE BAY THRU 06Z. SUB-SCA CONDITIONS THEN
THE LATTER HALF OF THE NIGHT THRU FRI NIGHT. MAY GO BACK TO SCA AS
BOUNDARY SHIFT SOUTH OF THE AREA AND STIFF ERLY FLOW DEVELOPS OVER
THE WATERS SATURDAY.
CDFNT APPROACHES SUN AND CROSSES WATERS SUN NGT. HV SLY WINDS
INCRSG AHD OF FNT FLLWD BY GOOD MIXING BHD IT. SCA PSBL W/IN THIS
WINDOW.
&&
.CLIMATE...
THE DEC 24 DAILY RECORDS...BOTH HIGHS AND HIGH MINS...
IAD...66 IN 1982...HIGH MIN 42 IN 2014...HIGH ALREADY BROKEN.
DCA...69 IN 1933...HIGH MIN 58 IN 1891...HIGH ALREADY BROKEN.
BWI...HIGH 65 IN 1990 AND 1982...HIGH MIN 53 IN 1891...HIGH
ALREADY BROKEN.
HIGH MINS ARE NOT OFFICIAL UNTIL MIDNIGHT BUT ALL LOOK
LIKELY TO BE BROKEN.
DEC MONTHLY RECORDS...BOTH HIGHS AND HIGH MINS...
IAD...HIGH 79 ON 12/6/1998...HIGH MIN 62 ON 12/22/2013
DCA...HIGH 79 ON 12/7/1998...HIGH MIN 59 ON 12/5/1973
BWI...HIGH 77 ON 12/7/1998, 12/6/1998 AND 12/29/1984...HIGH MIN 62
ON 12/22/2013
HIGHS ARE NOT EXPECTED TO BE BROKEN TODAY BUT HIGH MINS ARE VERY
POSSIBLE...ESPECIALLY DCA.
WARMEST DECEMBER AVERAGE TEMPERATURE THROUGH THE 23RD...
DCA...50.5 /2001/...50.2 /1998/...49.6 /2015/.
BWI...47.2 /1998/...47.1 /2001/...46.9 /2015/.
IAD...47.2 /1998/...46.5 /TIE 2001 AND 2015/.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FLASH FLOOD WATCH UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...FLASH FLOOD WATCH UNTIL 9 PM EST THIS EVENING FOR MDZ011-013-
014-504-506.
VA...FLASH FLOOD WATCH UNTIL 9 PM EST THIS EVENING FOR VAZ052>054.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ532-
533-540>542.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ534-537-543.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR ANZ530-
531-535-536-538-539.
&&
$$
SYNOPSIS...HTS
NEAR TERM...SEARS/RCM
SHORT TERM...SEARS/RCM
LONG TERM...HTS
AVIATION...SEARS/HTS/RCM
MARINE...SEARS/HTS/RCM
CLIMATE...DFH/RCM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
406 PM EST THU DEC 24 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 405 PM EST THU DEC 24 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WEST INTO THE CNTRL CONUS RESULTING IN SW FLOW FROM THE
PLAINS INTO THE CNTRL PLAINS TO THE NRN LAKES. A SHRTWV FROM SE SD
INTO WRN IA SUPPORTED AN AREA OF SNOW OVER IA. OTHERWISE...DRY
CONDITIONS PREVAILED FROM NRN MN THROUGH UPPER MI. WINDS HAVE
DIMINISHED THIS AFTERNOON AS THE PRES GRADIENT WEAKENS IN ADVANCE OF
HIGH PRES BUILDING TOWARD THE AREA FROM THE NRN PLAINS. EVEN WITH 850
MB TEMPS NEAR -10C...ONLY A FEW FLURRIES OBSERVED FOR WEST FLOW LES
AREAS AS INVERSION HEIGHTS HAVE DROPPED TO AROUND 3K-4K FT.
TONIGHT...WRLY FLOW WITH LOW LEVEL CONV WILL FAVOR CONTINUED CHANCE
OF LIGHT SNOW SHOWERS FOR THE KEWEENAW. HOWEVER...WITH THE TOP OF
THE CLOUD LAYER NEAR -10C...ICE NUCLEI MAY BE LACKING RESULTING
POTENTIAL FOR SOME FZDZ. OTHERWISE...WINDS WILL CONTINUE TO DIMINISH
WITH GRADUAL CLEARING OVER THE WEST HALF LATE TONIGHT. TEMPS SHOULD
DROP INTO THE UPPER TEENS TO LOWER 20S.
FRIDAY...THE RIDGE WILL BUILD INTO THE WRN LAKES WITH PARTLY TO
MOSTLY SUNNY SKIES. THE SUNSHINE WILL HELP PUSH TEMPS INTO THE 30 TO
35 RANGE...COLDEST OVER THE WEST WITH THE MOST SNOW COVER.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 328 PM EST THU DEC 24 2015
THE PHASING OF A COUPLE PIECES OF UPPER LEVEL ENERGY WILL RESULT IN
SOME LIGHT TO POTENTIALLY MODERATE SNOW AT TIMES OVER MUCH OR ALL OF
THE CWA LATE FRI NIGHT UNTO EARLY SAT NIGHT BEFORE TRANSITIONING TO
LES. MODELS CONTINUE TO TREND NW WITH THE HEAVIEST QPF/SNOW...SO
WILL CONTINUE SHOWING THAT TREND IN THE FORECAST. ALSO...MODELS ARE
NOT IN COMPLETE AGREEMENT ON PRECIP AMOUNTS...SO THERE REMAINS SOME
UNCERTAINTY THERE AS WELL. AT THIS POINT...EXPECT GREATEST SNOWFALL
FROM NCENTRAL UPPER MI...WHERE WINDS WILL TURN OUT OF THE NE ON SAT
PROVIDING UPSLOPE FORCING...TO THE KEWEENAW AND WRN UPPER MI. HAVE 3-
5 INCHES IN THESE AREAS...WITH LOWER AMOUNTS TO THE S AND E. BLOWING
SNOW WILL BE ON THE INCREASE NEAR LAKE SUPERIOR ON SAT AS WIND GUSTS
INCREASE TO 25-30MPH AND BECOME NORTHERLY.
THE WINDS WILL CARRY MUCH COLDER AIR AS AN UPPER TROUGH DROPS
THROUGH SAT NIGHT INTO SUN MORNING. 850MB TEMPS WILL DROP FROM
AROUND -8C AT 00Z SUN TO BETWEEN -15C AND -20C LATE SUN INTO SUN
NIGHT. WINDS WILL BE OUT OF THE NW UNTIL AFTER 00Z MON WHEN WINDS
WILL TURN N-NNE...THEN OUT OF THE E MON MORNING AS A HIGH PASSES N
OF THE AREA. MOST OF THIS TIME WILL SEE INVERSION HEIGHT AROUND
4KFT...WITH GOOD SNOW RATIOS...BUT A SHORTWAVE MAY MOVE THROUGH SUN
EVENING THAT WOULD BRING A HEAVIER BURST OF SNOW AS THE WINDS TURN
MORE N-NNE. OVERALL GOOD CONFIDENCE OF LIGHT TO OCCASIONALLY
MODERATE LES AND PATCHY BLOW SNOW IN NW WIND SNOWBELTS...BECOMING N-
NNE SNOW BELTS LATE SUN INTO MON MORNING. THIS SHOULD RESULT IN
SEVERAL INCHES OF SNOW DURING THIS PERIOD. WILL INCREASE
QPF/SNOWFALL AMOUNTS AND POPS.
FOR NEXT WEEK...LOTS OF UNCERTAINTY AS THE UPPER LOW THAT WILL FORM
OVER THE U.S./MEXICO BORDER LOOKS TO BREAK DOWN AND SHIFT THROUGH
THE REGION TUE INTO TUE NIGHT. THERE ARE A LOT OF VARIABLES WITH
SNOWFALL FORECAST FOR THAT TIME...BUT THE OVERALL APPEARANCE IS THAT
A MAJOR PATTERN CHANGE MAY OCCUR. MODELS SHOW THE LONGWAVE UPPER
TROUGH THAT HAS BEEN OVER THE WRN CONUS SHIFTING TO THE ERN
CONUS...WITH COLDER AIR AND MORE ACTIVE WEATHER THE GENERAL THEME.
STAY TUNED TO LATER FORECASTS FOR DETAILS NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1244 PM EST THU DEC 24 2015
VERY WINDY CONDITIONS...WITH GUSTS AS HIGH AS 45 MPH AT CMX WILL
GRADUALLY DIMINISH THIS AFTERNOON AS HIGH PRESSURE OVER THE PLAINS
BUILDS TOWARD THE REGION. ENOUGH LOW LEVEL MOISTURE WILL LINGER TO
SUPPORT MVFR CIGS THROUGH MUCH OF TONIGHT. CONDITIONS AT IWD AND SAW
IMPROVE TO VFR TOWARD FRI MORNING WHILE CMX REMAINS MVFR TIL MIDDAY
FRI WITH UPSLOPE WESTERLY FLOW CONTINUING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EST THU DEC 24 2015
AS HIGH PRESSURE BUILDS TOWARD THE REGION THIS
EVENING...WINDS WILL DROP BELOW GALE FORCE. HIGH PRESSURE BUILDS
ACROSS THE LAKE FOR CHRISTMAS DAY BEFORE ANOTHER LOW MOVES ACROSS
THE SOUTHERN GREAT LAKES SATURDAY NIGHT. STRONGER HIGH PRESSURE IS
EXPECTED TO BUILD ACROSS THE UPPER GREAT LAKES SUNDAY INTO MONDAY.
AFTER TONIGHT...WINDS SHOULD STAY BELOW 30KT ACROSS LAKE SUPERIOR
THROUGH MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EST THIS EVENING FOR LSZ265>267.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ243>251-264.
LAKE MICHIGAN...
GALE WARNING UNTIL 5 PM EST THIS AFTERNOON FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1011 AM EST THU DEC 24 2015
.UPDATE...
STRONG LOW PRESSURE...971 MB...HAS LIFTED FROM NORTH OF LAKE
SUPERIOR INTO ST JAMES BY THIS MORNING. HIGH PRESSURE MEANWHILE
HAS BEEN PROGRESSIVELY BUILDING INTO THE OHIO VALLEY AND NEW
ENGLAND...EXPANDING UP TOWARDS THE CENTRAL AND SOUTHERN GREAT
LAKES AS THE LOW LIFTS NORTHWARD. THIS TREND WILL CONTINUE
TODAY...ALLOWING THE SURFACE PRESSURE GRADIENT TO CONTINUE
DECREASING ACROSS THE AREA. STRONGER CORE OF WINDS ALOFT WILL ALSO
EXIT NORTHEAST WITH THE UPPER SYSTEM...ENDING POTENTIAL FOR
STRONGER GUSTS TO MIX DOWN TO THE SURFACE AS WE HEAD INTO THE
AFTERNOON. WIND ADVISORY WAS DROPPED EARLIER TODAY...AND EXPECT
LIGHT WINDS BY MID-EVENING.
&&
.AVIATION...ISSUED 653 AM EST THU DEC 24 2015
ALMOST DUE MERIDIONAL TRAJECTORY OF POWERFUL LOW PRESSURE SYSTEM
TRACKING AWAY FROM SOUTHEASTERN MICHIGAN WILL ALLOW THE PRESSURE
GRADIENT TO SLACKEN QUICKLY THIS MORNING. BEEN WITNESSING A STEADY
WEAKENING TREND FOR SURFACE WINDS...WHICH WILL CONTINUE DURING THE
FIRST COUPLE HOURS OF THE TAF PERIOD. MODELS SHOW TRAPPED MOISTURE
BELOW SUBSIDENCE INVERSION IN CYCLONIC FLOW TODAY. THIS MOISTURE
IS EXPECTED TO EVOLVE INTO A DIURNAL STRATOCUMULUS FIELD. WITH THE
ABUNDANCE OF OBSERVED MVFR CIGS/MOISTURE AROUND 3.0 KFT AGL...AND
LATEST DATA FROM EXPERIMENTAL HRRR AND RUC...DECIDED TO GO MORE
BEARISH WITH RESPECT TO CLOUDS TODAY. EXPECTING THE LOW CLOUD TO
VANISH PRETTY RAPIDLY LATE AFTERNOON WITH LOSS OF DIURNAL
SUPPORT...BUT MID CLOUD FROM COLORADO SHORTWAVE WILL BE RAPIDLY
APPROACHING. UNCERTAINTY EXISTS SURROUNDING PRECIPITATION
POTENTIAL TONIGHT. DID ADD IT IN THE NORTH GIVEN QUALITY OF
MOISTURE ALOFT. HOWEVER...SYNOPTIC SCALE WILL NOT BE FAVORABLE FOR
ASCENT.
FOR DTW...WEST SOUTHWEST SURFACE WINDS HAVE ALREADY SETTLED DOWN
INTO THE 15 TO 25 KNOT RANGE. UNCERTAINTIES FOR THE DTW FORECAST ARE
WHETHER OR NOT MVFR CIGS WILL BUILD SOUTH AND EAST AND SUBSEQUENT TIMING.
MODELS SUPPORT IT WILL...AROUND THE TIME CLOUD EVOLVES INTO
STRATOCUMULUS DURING THE AFTERNOON.
//DTW THRESHOLD PROBABILITIES...
* MODERATE FOR CEILING BELOW 5000 FEET FOR TODAY.
&&
.PREV DISCUSSION...ISSUED 348 AM EST THU DEC 24 2015
DISCUSSION...
.WIND ADVISORY CONTINUES THROUGH MID MORNING...
INTENSE LOW PRESSURE (974 MB AT 3 AM) OVER NORTHERN ONTARIO WILL
CONTINUE TO PULL AWAY FROM THE GREAT LAKES REGION TODAY. ASSOCIATED
COLD FRONT PASSAGE AND MID LEVEL DRY SLOT IMPACTING SOUTHEAST
MICHIGAN AT PRESS TIME...AND OBSERVATIONS CONTINUE TO SUPPORT 45 MPH
TO 55 MPH WIND GUSTS...HIGHEST GUSTS NORTH OF I-69 WHERE MAX
PRESSURE GRADIENT/COLD ADVECTION EXISTS DUE TO THE LOW PULLING OFF
NORTH-NORTHEAST TOWARD JAMES BAY. WINDS WILL DROP OFF QUICKLY...AND
MAY BE ABLE TO CANCEL THE ADVISORY EARLY...ESPECIALLY SOUTH.
TEMPERATURES IN THE MID 50S TO AROUND 60 DEGREES AS OF 3 AM LOOK TO
BE DROPPING INTO THE MID TO UPPER 40S TOWARD 12Z...WHICH LOOKS TO BE
IN THE BALL PARK OF MAXES. TEMPERATURES COULD CONTINUE TO FALL
DURING THE MORNING HOURS BEFORE MAKING A MODEST RECOVERY DURING THE
AFTERNOON WITH LATE DECEMBER SUNSHINE.
A BIT OF A NUISANCE FORECAST TONIGHT AS UPPER WAVE COMING OUT OF
COLORADO THIS MORNING WILL STREAK NORTHEAST AND SHEAR OUT...RUNNING
INTO MOSTLY UPPER LEVEL CONFLUENT FLOW OVER THE CENTRAL GREAT
LAKES...AS SURFACE HIGH (1022 MB) TRACKS INTO SOUTHERN LOWER
MICHIGAN. HOWEVER...MID LEVEL FGEN/ISENTROPIC ASCENT WITH THE UPPER
WAVE MAY BE SUFFICIENT TO GENERATE PRECIPITATION (ABOUT 4 G/KG OF
SPECIFIC HUMIDITY TO WORK WITH)...BUT WILL HAVE TO OVERCOME DRY AND
RELATIVELY MILD LOW LEVELS (925 MB TEMPS OF ZERO TO 4 C RANGE). BOTH
00Z NAM AND EURO INDICATING SOME LIGHT QPF...BUT DIFFERENT
LOCATIONS...AND WILL CARRY LOW CHANCE POPS FOR SOME LIGHT RAIN OR
SPRINKLES. THINKING PRECIPITATION TYPE WILL BE PREDOMINATELY RAIN
DUE TO LIGHT PRECIPITATION RATES...PREVENTING SUFFICIENT WET BULB
COOLING. CLOUDS EXPECTED TO HOLD SURFACE TEMPS IN THE 30S.
WATER VAPOR IMAGERY SHOWS VERY IMPRESSIVE UPPER LEVEL WAVE/ENERGY
JUST OFF THE COAST OF THE PACIFIC NORTHWEST...WITH THE BULK OF THIS
PV/ENERGY SETTLING OVER THE FOUR CORNERS/NORTHERN MEXICO OVER THE
WEEKEND. SPLIT UPPER LEVEL FLOW WITH A NORTHERN STREAM SHORTWAVE
TROUGH STILL ON TRACK TO SLIDE THROUGH THE GREAT LAKES REGION ON
SUNDAY. A WAVE OF LOW PRESSURE PRECEDING THIS TROUGH WILL MOVE
THROUGH FAR SOUTHERN LOWER MICHIGAN ON SATURDAY...DRAWING UP A LOT
OF WARMTH AND MOISTURE AGAIN...AS 850 MB DEW PTS REACH 10 C ONCE
AGAIN...PER 00Z EURO. THIS AMOUNT OF LOW LEVEL MOISTURE IS RECORD
SETTING FOR THE END OF DECEMBER PER SPC SOUNDING CLIMATOLOGY PAGE.
ALTHOUGH RAIN DEVELOPING SATURDAY AFTERNOON/EVENING IS LIKELY TO
DEFINITE...PUNCHING INTO THE WARM SECTOR IS A BIT MORE
UNCERTAIN...AND THUS MAXES WILL BE FORECASTED MORE
CONSERVATIVELY...MID 40S TO AROUND 50 DEGREES. OBVIOUSLY LOCATIONS
TOWARD THE OHIO BORDER STAND BEST CHANCE TO PUNCH WELL ABOVE 50
DEGREES...BUT THAT MAY NOT OCCUR UNTIL SATURDAY EVENING.
STRONG COLD ADVECTION WILL TAKE PLACE FOR THE SECOND HALF OF THE
WEEKEND BEHIND THE SURFACE WAVE...AS STRONG HIGH (1045 MB) BUILDS
OVER ONTARIO SUNDAY NIGHT. THIS HIGH LOOKS TO SUPPLY/MAINTAIN COLD
LOW LEVEL FEED EARLY NEXT WEEK WHILE THE PREVIOUS MENTIONED FOUR
CORNERS SYSTEM EJECTS NORTHEAST...POTENTIALLY REACHING THE WESTERN
GREAT LAKES ON TUESDAY...PER 00Z EURO. THIS SCENARIO WOULD IMPLY A
PERIOD OF FREEZING RAIN BEFORE CHANGEOVER TO RAIN...WHILE THE 00Z
CANADIAN IS FARTHER SOUTH AND IMPLIES SNOW. MIXED GFS ENSEMBLE
MEMBERS GIVE CREDENCE TO BOTH SOLUTIONS...SO CERTAINLY POSSIBLE WE
WILL HAVE A WINTRY MESS/MIX ON OUR HANDS.
MARINE...
POWERFUL SURFACE LOW PRESSURE...NOW NORTH OF LAKE SUPERIOR...WILL
RAPIDLY LIFT NORTHWARD TO JAMES BAY. A STRONG COLD FRONT WILL SURGE
ACROSS SOUTHEASTERN MICHIGAN DURING THE FIRST HOUR OR TWO OF THE
FORECAST PERIOD AND ACROSS LAKE HURON BY 12Z. POST FRONTAL SURFACE
WINDS HAVE CERTAINLY BEEN ROBUST WITH SOME SFC OBSERVATIONS ON LAND
OVER LOWER MICHIGAN PUSHING/REACHING 50 KNOTS AT TIMES. BEST
ISALLOBARIC SUPPORT WILL PUSH NORTHWARD ALONG LAKE MICHIGAN...BUT
ENOUGH GRADIENT FLOW WITH STEEPENING LOW LEVEL LAPSE RATES WILL
SUPPORT A HIGH END GALE EVENT OF 45 KNOTS OVER SAGINAW BAY AND THE
NORTHERN LAKE HURON BASIN. FARTHER SOUTH...GALE FORCE WINDS OF 40
KNOTS WILL BE POSSIBLE. THE ROBUST WIND FIELD IS EXPECTED TO BE
RATHER SHORT LIVED WITH DIMINISHING WINDS EXPECTED DURING THE REST
OF THE DAY. WIND GUSTS OVER LAKE HURON ARE EXPECTED TO DROP BELOW 20
KNOTS BY 06Z FRIDAY. A BRIEF SURFACE RIDGE WILL BUILD INTO THE
REGION FOR FRIDAY BEFORE THE NEXT LOW PRESSURE SYSTEM SET ITS SIGHTS
ON THE MICHIGAN OHIO BORDER FOR SATURDAY NIGHT. MODELS ARE SHOWING
LEGITIMATE COLD AIR ADVECTION OCCURRING DOWN INTO THE SOUTHERN
GREAT LAKES FOR A TIME SUNDAY NIGHT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WARNING UNTIL 3 PM EST THIS AFTERNOON FOR LHZ361>363-421-441-
462.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 7 PM EST THIS
EVENING FOR LHZ421-441.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LHZ442-443.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LHZ422.
GALE WARNING UNTIL NOON EST TODAY FOR LHZ422.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......HLO
AVIATION.....CB
DISCUSSION...SF
MARINE.......CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
653 AM EST THU DEC 24 2015
.AVIATION...
ALMOST DUE MERIDIONAL TRAJECTORY OF POWERFUL LOW PRESSURE SYSTEM
TRACKING AWAY FROM SOUTHEASTERN MICHIGAN WILL ALLOW THE PRESSURE
GRADIENT TO SLACKEN QUICKLY THIS MORNING. BEEN WITNESSING A STEADY
WEAKENING TREND FOR SURFACE WINDS...WHICH WILL CONTINUE DURING THE
FIRST COUPLE HOURS OF THE TAF PERIOD. MODELS SHOW TRAPPED MOISTURE
BELOW SUBSIDENCE INVERSION IN CYCLONIC FLOW TODAY. THIS MOISTURE
IS EXPECTED TO EVOLVE INTO A DIURNAL STRATOCUMULUS FIELD. WITH THE
ABUNDANCE OF OBSERVED MVFR CIGS/MOISTURE AROUND 3.0 KFT AGL...AND
LATEST DATA FROM EXPERIMENTAL HRRR AND RUC...DECIDED TO GO MORE
BEARISH WITH RESPECT TO CLOUDS TODAY. EXPECTING THE LOW CLOUD TO
VANISH PRETTY RAPIDLY LATE AFTERNOON WITH LOSS OF DIURNAL
SUPPORT...BUT MID CLOUD FROM COLORADO SHORTWAVE WILL BE RAPIDLY
APPROACHING. UNCERTAINTY EXISTS SURROUNDING PRECIPITATION
POTENTIAL TONIGHT. DID ADD IT IN THE NORTH GIVEN QUALITY OF
MOISTURE ALOFT. HOWEVER...SYNOPTIC SCALE WILL NOT BE FAVORABLE FOR
ASCENT.
FOR DTW...WEST SOUTHWEST SURFACE WINDS HAVE ALREADY SETTLED DOWN
INTO THE 15 TO 25 KNOT RANGE. UNCERTAINTIES FOR THE DTW FORECAST ARE
WHETHER OR NOT MVFR CIGS WILL BUILD SOUTH AND EAST AND SUBSEQUENT TIMING.
MODELS SUPPORT IT WILL...AROUND THE TIME CLOUD EVOLVES INTO
STRATOCUMULUS DURING THE AFTERNOON.
//DTW THRESHOLD PROBABILITIES...
* MODERATE FOR CEILING BELOW 5000 FEET FOR TODAY.
&&
.PREV DISCUSSION...ISSUED 348 AM EST THU DEC 24 2015
DISCUSSION...
..WIND ADVISORY CONTINUES THROUGH MID MORNING...
INTENSE LOW PRESSURE (974 MB AT 3 AM) OVER NORTHERN ONTARIO WILL
CONTINUE TO PULL AWAY FROM THE GREAT LAKES REGION TODAY. ASSOCIATED
COLD FRONT PASSAGE AND MID LEVEL DRY SLOT IMPACTING SOUTHEAST
MICHIGAN AT PRESS TIME...AND OBSERVATIONS CONTINUE TO SUPPORT 45 MPH
TO 55 MPH WIND GUSTS...HIGHEST GUSTS NORTH OF I-69 WHERE MAX
PRESSURE GRADIENT/COLD ADVECTION EXISTS DUE TO THE LOW PULLING OFF
NORTH-NORTHEAST TOWARD JAMES BAY. WINDS WILL DROP OFF QUICKLY...AND
MAY BE ABLE TO CANCEL THE ADVISORY EARLY...ESPECIALLY SOUTH.
TEMPERATURES IN THE MID 50S TO AROUND 60 DEGREES AS OF 3 AM LOOK TO
BE DROPPING INTO THE MID TO UPPER 40S TOWARD 12Z...WHICH LOOKS TO BE
IN THE BALL PARK OF MAXES. TEMPERATURES COULD CONTINUE TO FALL
DURING THE MORNING HOURS BEFORE MAKING A MODEST RECOVERY DURING THE
AFTERNOON WITH LATE DECEMBER SUNSHINE.
A BIT OF A NUISANCE FORECAST TONIGHT AS UPPER WAVE COMING OUT OF
COLORADO THIS MORNING WILL STREAK NORTHEAST AND SHEAR OUT...RUNNING
INTO MOSTLY UPPER LEVEL CONFLUENT FLOW OVER THE CENTRAL GREAT
LAKES...AS SURFACE HIGH (1022 MB) TRACKS INTO SOUTHERN LOWER
MICHIGAN. HOWEVER...MID LEVEL FGEN/ISENTROPIC ASCENT WITH THE UPPER
WAVE MAY BE SUFFICIENT TO GENERATE PRECIPITATION (ABOUT 4 G/KG OF
SPECIFIC HUMIDITY TO WORK WITH)...BUT WILL HAVE TO OVERCOME DRY AND
RELATIVELY MILD LOW LEVELS (925 MB TEMPS OF ZERO TO 4 C RANGE). BOTH
00Z NAM AND EURO INDICATING SOME LIGHT QPF...BUT DIFFERENT
LOCATIONS...AND WILL CARRY LOW CHANCE POPS FOR SOME LIGHT RAIN OR
SPRINKLES. THINKING PRECIPITATION TYPE WILL BE PREDOMINATELY RAIN
DUE TO LIGHT PRECIPITATION RATES...PREVENTING SUFFICIENT WET BULB
COOLING. CLOUDS EXPECTED TO HOLD SURFACE TEMPS IN THE 30S.
WATER VAPOR IMAGERY SHOWS VERY IMPRESSIVE UPPER LEVEL WAVE/ENERGY
JUST OFF THE COAST OF THE PACIFIC NORTHWEST...WITH THE BULK OF THIS
PV/ENERGY SETTLING OVER THE FOUR CORNERS/NORTHERN MEXICO OVER THE
WEEKEND. SPLIT UPPER LEVEL FLOW WITH A NORTHERN STREAM SHORTWAVE
TROUGH STILL ON TRACK TO SLIDE THROUGH THE GREAT LAKES REGION ON
SUNDAY. A WAVE OF LOW PRESSURE PRECEDING THIS TROUGH WILL MOVE
THROUGH FAR SOUTHERN LOWER MICHIGAN ON SATURDAY...DRAWING UP A LOT
OF WARMTH AND MOISTURE AGAIN...AS 850 MB DEW PTS REACH 10 C ONCE
AGAIN...PER 00Z EURO. THIS AMOUNT OF LOW LEVEL MOISTURE IS RECORD
SETTING FOR THE END OF DECEMBER PER SPC SOUNDING CLIMATOLOGY PAGE.
ALTHOUGH RAIN DEVELOPING SATURDAY AFTERNOON/EVENING IS LIKELY TO
DEFINITE...PUNCHING INTO THE WARM SECTOR IS A BIT MORE
UNCERTAIN...AND THUS MAXES WILL BE FORECASTED MORE
CONSERVATIVELY...MID 40S TO AROUND 50 DEGREES. OBVIOUSLY LOCATIONS
TOWARD THE OHIO BORDER STAND BEST CHANCE TO PUNCH WELL ABOVE 50
DEGREES...BUT THAT MAY NOT OCCUR UNTIL SATURDAY EVENING.
STRONG COLD ADVECTION WILL TAKE PLACE FOR THE SECOND HALF OF THE
WEEKEND BEHIND THE SURFACE WAVE...AS STRONG HIGH (1045 MB) BUILDS
OVER ONTARIO SUNDAY NIGHT. THIS HIGH LOOKS TO SUPPLY/MAINTAIN COLD
LOW LEVEL FEED EARLY NEXT WEEK WHILE THE PREVIOUS MENTIONED FOUR
CORNERS SYSTEM EJECTS NORTHEAST...POTENTIALLY REACHING THE WESTERN
GREAT LAKES ON TUESDAY...PER 00Z EURO. THIS SCENARIO WOULD IMPLY A
PERIOD OF FREEZING RAIN BEFORE CHANGEOVER TO RAIN...WHILE THE 00Z
CANADIAN IS FARTHER SOUTH AND IMPLIES SNOW. MIXED GFS ENSEMBLE
MEMBERS GIVE CREDENCE TO BOTH SOLUTIONS...SO CERTAINLY POSSIBLE WE
WILL HAVE A WINTRY MESS/MIX ON OUR HANDS.
MARINE...
POWERFUL SURFACE LOW PRESSURE...NOW NORTH OF LAKE SUPERIOR...WILL
RAPIDLY LIFT NORTHWARD TO JAMES BAY. A STRONG COLD FRONT WILL SURGE
ACROSS SOUTHEASTERN MICHIGAN DURING THE FIRST HOUR OR TWO OF THE
FORECAST PERIOD AND ACROSS LAKE HURON BY 12Z. POST FRONTAL SURFACE
WINDS HAVE CERTAINLY BEEN ROBUST WITH SOME SFC OBSERVATIONS ON LAND
OVER LOWER MICHIGAN PUSHING/REACHING 50 KNOTS AT TIMES. BEST
ISALLOBARIC SUPPORT WILL PUSH NORTHWARD ALONG LAKE MICHIGAN...BUT
ENOUGH GRADIENT FLOW WITH STEEPENING LOW LEVEL LAPSE RATES WILL
SUPPORT A HIGH END GALE EVENT OF 45 KNOTS OVER SAGINAW BAY AND THE
NORTHERN LAKE HURON BASIN. FARTHER SOUTH...GALE FORCE WINDS OF 40
KNOTS WILL BE POSSIBLE. THE ROBUST WIND FIELD IS EXPECTED TO BE
RATHER SHORT LIVED WITH DIMINISHING WINDS EXPECTED DURING THE REST
OF THE DAY. WIND GUSTS OVER LAKE HURON ARE EXPECTED TO DROP BELOW 20
KNOTS BY 06Z FRIDAY. A BRIEF SURFACE RIDGE WILL BUILD INTO THE
REGION FOR FRIDAY BEFORE THE NEXT LOW PRESSURE SYSTEM SET ITS SIGHTS
ON THE MICHIGAN OHIO BORDER FOR SATURDAY NIGHT. MODELS ARE SHOWING
LEGITIMATE COLD AIR ADVECTION OCCURRING DOWN INTO THE SOUTHERN
GREAT LAKES FOR A TIME SUNDAY NIGHT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ047>049-053>055-
060>063-068>070-075-076-082-083.
LAKE HURON...GALE WARNING UNTIL NOON EST TODAY FOR LHZ421-422-441-462.
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LHZ442-443-463-464.
GALE WARNING UNTIL 3 PM EST THIS AFTERNOON FOR LHZ361>363.
LAKE ST CLAIR...GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LEZ444.
&&
$$
AVIATION.....CB
DISCUSSION...SF
MARINE.......CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1243 AM EST THU DEC 24 2015
.AVIATION...
GUSTY SOUTH WIND AND BORDERLINE VFR/MVFR CEILING WILL PRECEDE A COLD
FRONT THAT WILL SURGE ACROSS LOWER MICHIGAN BEFORE SUNRISE. THE
LATEST OBSERVATIONS SUPPORT JUST A FEW BRIEF SHOWERS ALONG THE
FRONT...LEAVING THE MAIN STORY AS STRONG WESTERLY WIND GUSTS
REACHING THE 30 TO 40 KNOT RANGE. THERE IS POTENTIAL FOR GUSTS UP TO
45 KNOTS WHICH WILL BE MONITORED FOR IN UPSTREAM OBSERVATIONS DURING
THE NIGHT. THE GUSTY CONDITIONS WILL LAST THROUGH MID MORNING BEFORE
STEADILY DECREASING DURING THE AFTERNOON. THE AIR BEHIND THE FRONT
WILL BE JUST SLIGHTLY COOLER BUT MUCH DRIER WHICH WILL SUPPORT VFR
CONDITIONS INTO THURSDAY EVENING.
FOR DTW... BORDERLINE MVFR/VFR CEILING AND A BREAK IN PRECIPITATION
WILL CONTINUE DURING THE EARLY MORNING...ALONG WITH GUSTY SOUTH
WIND. TIMING ON THE COLD FRONTAL PASSAGE LOOKS SOLID AROUND 09Z WITH
WESTERLY WIND GUSTS REACHING THE 30 TO 40 KNOT RANGE THROUGH LATE
MORNING.
//DTW THRESHOLD PROBABILITIES...
* MODERATE FOR CEILING BELOW 5000 FEET FOR THE REST OF TONIGHT.
* MODERATE TO HIGH FOR GUSTS EXCEEDING CROSSWIND THRESHOLD AFTER 09Z.
&&
.PREV DISCUSSION...ISSUED 1027 PM EST WED DEC 23 2015
UPDATE...
THE FORECAST UPDATE WILL EXTEND THE WIND ADVISORY OVER THE REST
OF SE MICHIGAN AND MAKE IT VALID WITH ISSUANCE. MID TO LATE
EVENING SURFACE OBSERVATIONS REPORT FREQUENT SOUTH WIND GUSTS IN
THE MID 30 MPH RANGE WITH A FEW REPORTS OVER 40 MPH. THIS IS
OCCURRING IN THE WARM SECTOR IN PLACE OVER LOWER MICHIGAN
ASSOCIATED WITH RAPIDLY DEEPENING LOW PRESSURE OVER WISCONSIN. THE
NEUTRAL STABILITY PROFILE ADVERTISED IN RAP MODEL SOUNDINGS
SUGGESTS WARM SECTOR GUSTS COULD REACH 45 MPH BEFORE THE COLD
FRONT ARRIVES OVERNIGHT. AS FOR THE COLD FRONT ITSELF...UPSTREAM
OBSERVATIONS REPORT PEAK GUSTS AROUND 50 MPH AS FAR SOUTH AS
PEORIA/IL WITHIN STRONG ISALLOBARIC FORCING. THE EXTRA FORCING AND
50 MPH PEAK GUSTS WILL BE SHORT-LIVED BUT MID 40 MPH GUSTS WILL
REMAIN COMMON THROUGH MID THURSDAY MORNING. THE 10 AM EXPIRATION
TIME OF THE HEADLINE LOOKS GOOD.
PREV DISCUSSION...ISSUED 323 PM EST WED DEC 23 2015
DISCUSSION...
STRONG SURFACE LOW HAS BEGUN ITS NEXT DEEPENING PHASE THIS AFTERNOON
AS VIGOROUS SHORTWAVE HAS ROUNDED THE BASE OF THE MEAN UPPER LEVEL
TROUGH OVER THE PLAINS/MIDWEST. THE 982MB LOW OVER EC IOWA WILL
DEEPEN TO ABOUT 974MB BY THE TIME IT REACHES LAKE SUPERIOR TONIGHT
AND THEN CONTINUE STRENGTHEN IS IT LIFTS TO JAMES BAY AND BEYOND ON
THURSDAY.
WARM FRONT IN ADVANCE OF THIS SYSTEM IS CURRENTLY WORKING NORTH
THROUGH THE FORECAST AREA WITH ALL LOCATIONS NOW CLIMB THROUGH THE
50S WITH A FEW 60 DEGREE READINGS NOTED SOUTH OF DETROIT. DEWPOINTS
WITHIN THIS MILDEST SECTOR HAVE ALSO CLIMBED INTO THE UPPER 50S AS
MODELS SUGGESTED WOULD OCCUR. AS THE WARM AND MOIST AIR CONTINUES TO
OVERSPREAD THE AREA...EXPECT TEMPERATURES TO CLIMB INTO THE 60S AREA
WIDE...SETTING RECORD HIGH TEMPERATURES FOR THE DAY AND ALSO SETTING
UP A MARGINALLY UNSTABLE AIRMASS OVER PARTS OF THE AREA BY THIS
EVENING.
THIS WILL ALLOW ONGOING STRONG TO LOCALLY SEVERE CONVECTIVE LINE
SEGMENTS FROM WESTERN INDIANA AND SOUTHEAST ILLINOIS TO WORK INTO
THE AREA EARLY THIS EVENING. THERE WILL MOST LIKELY BE A SLIGHT
WEAKENING TREND ONCE THIS ACTIVITY ENCROACHES ON THE AREA AS THE
AIRMASS STILL WILL NOT BE QUITE A UNSTABLE AS THE CURRENT AIR
FEEDING INTO ONGOING STORMS TO THE SOUTHWEST. THIS WILL RESULT IN
GUSTY WINDS WITH LOCALLY DAMAGING WIND GUSTS STILL POSSIBLE WITHIN
THE STRONGEST PORTIONS OF THE CONVECTIVE LINE(S) THAT MAKE IT THIS
FAR NORTHEAST.
WHILE A LOW LIKELIHOOD...AN ISOLATED TORNADO STILL CANNOT BE RULED
OUT GIVEN THE STRONG LOW LEVEL SHEAR THAT WILL BE IN PLACE ONCE THIS
ACTIVITY PROPAGATES INTO THE AREA. BY AND LARGE THE MOST LIKELY
SEVERE WEATHER SCENARIO WILL BE ISOLATED POCKETS OF 60 MPH WIND
GUSTS CAUSING SOME DAMAGE AS CONVECTION TAPS INTO THE 60+ KNOT LOW
LEVEL FLOW AND BRINGS SOME OF IT TO THE SURFACE AT TIMES.
ADDITIONAL SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE FROM MID
EVENING INTO THE OVERNIGHT AS THE WARM AND MOIST AIRMASS REMAINS IN
PLACE AND EVEN BUILDS SLIGHTLY IN ADVANCE OF APPROACHING COLD FRONT
WHICH WILL CROSS THE AREA ROUGHLY BETWEEN 06Z-09Z. WITH THE SURFACE
LOW TRACK SO FAR TO THE NORTHWEST...BEST PUNCH OF WIND ALONG AND
BEHIND THIS FRONT WILL BE FOCUSED OVER THE NORTHERN CWA...AND WILL
LIMIT THE EXPECT WIND ADVISORY TO AREAS GENERALLY ALONG AND NORTH OF
INTERSTATE 69. THIS ADVISORY WILL BE RATHER SHORT LIVED AS WELL AS
THE RAPID MOVEMENT OF THE LOW INTO CANADA WILL ALLOW WINDS TO RELAX
RATHER QUICKLY THURSDAY MORNING.
MUCH QUIETER WEATHER WILL SET UP FOR THURSDAY AND FRIDAY AS HIGH
PRESSURE BUILDS EAST ACROSS THE AREA. WITH ONLY A MINOR INCURSION OF
COLDER POLAR AIR INTO AREA BEHIND THIS SYSTEM...TEMPERATURES...WHILE
COOLER...WILL REMAIN ABOVE AVERAGE FOR LATE DECEMBER. EXPECT HIGHS
IN THE 40S TO AROUND 50 THURSDAY AND IN THE 40S FRIDAY.
SURFACE LOW DEVELOPING NORTHEASTWARD ALONG BAROCLINIC ZONE PROGGED
TO MOVE THROUGH SE MI SAT. PLENTY OF MOISTURE TO BE LIFTED OVER THE
FRONTAL ZONE /PWAT NEAR 1.50 IN/ WILL SPELL LIKELY RAIN SAT/SAT
NIGHT AND POSSIBLY LINGERING INTO SUNDAY. THE RAIN COULD BE HEAVY
OVER THE SOUTH IF THE FRONT STAYS RELATIVELY STATIONARY AS SOME NWP
IS DEPICTING. THIS SHOULD BE MOSTLY RAIN BUT COULD BRIEFLY END AS
SNOW SAT NIGHT/SUN. ACCUMULATIONS DO NOT LOOK LIKELY AS THE MAJORITY
OF THE PRECIP WILL BE ON THE WARM SIDE. ATTENTION THEN TURNS TO
STRONG CUTOFF LOW EJECTING NWD FROM TX TO THE GREAT LAKES MON/TUE.
STILL SIGNIFICANT INTERMODEL AND RUN-TO-RUN MODEL DIFFERENCES IN
TIMING AND LOW TRACK...BUT ENOUGH CONFIDENCE TO GO WITH LIKELY POPS
CENTERED AROUND MONDAY NIGHT. P TYPE WILL BE TRICKY AND WILL NOT GET
TOO CUTE WITH THE DETAILS THIS FAR OUT. POTENTIAL DOES EXIST FOR
FZRA ON THE LEADING EDGE OF THE PRECIP. THE MOST LIKELY TIME FRAME
FOR THIS IS MONDAY NIGHT BEFORE WE GET INTO THE WARM SECTOR ON
TUESDAY AS DEPICTED BY THE EURO. MEANWHILE THE GFS HAS CONTINUED TO
TREND EASTWARD WITH THE LOW WHICH WOULD OPEN THE DOOR FOR SNOW FOR
PORTIONS OF OUR AREA. DUE TO MODEL DIFFERENCES AND LONG TIME
HORIZON...KEPT BROADBRUSH RAIN/SNOW MENTION FOR NOW.
MARINE...
A STRONG LOW PRESSURE SYSTEM WILL CONTINUE TO STRENGTHEN AS IT
TRACKS NORTH THROUGH THE WESTERN GREAT LAKES OVERNIGHT REACHING
JAMES BAY BY THURSDAY MORNING. THE LOW WILL PULL A COLD FRONT
THROUGH THE EASTERN GREAT LAKES LATE TONIGHT AROUND 09Z. STRONG
WINDS WILL OCCUR BOTH AHEAD OF...AND BEHIND THE COLD FRONT LEADING
TO A LONG DURATION GALE EVENT ACROSS LAKE HURON. THIS EVENING AHEAD
OF THE FRONT...ALREADY GUSTY WINDS WILL BE ENHANCED BY PREFRONTAL
RAIN SHOWERS MIXING DOWN STRONGER WINDS ALOFT MAINLY ACROSS NORTHERN
LAKE HURON. WINDS WILL THEN TURN WESTERLY AND INCREASE FURTHER AS A
TIGHT PRESSURE GRADIENT SOUTH OF THE LOW CENTER LIFTS UP THROUGH THE
REGION. WIND GUSTS WILL REACH STRONG GALE FORCE AROUND 45 KNOTS OVER
NORTHERN LAKE HURON. THE SOUTHERN END OF THE BASIN WILL BE FURTHER
REMOVED FROM THE TIGHTEST GRADIENT BUT SHOULD STILL SEE GALE FORCE
GUSTS OF 35 TO 40 KNOTS LATE TONIGHT INTO THURSDAY MORNING. WINDS
WILL THEN DIMINISH THROUGH THE DAY THURSDAY AS THE LOW QUICKLY LIFTS
NORTHWARD AWAY FROM THE LAKES. WIND GUSTS ARE EXPECTED TO DROP BELOW
20 KNOTS BY 06Z FRIDAY.
HYDROLOGY...
A LOW PRESSURE SYSTEM CURRENTLY OVER IOWA WILL CONTINUE TO
STRENGTHEN AS IT LIFTS NORTH THROUGH THE OVERNIGHT...REACHING JAMES
BAY BY THURSDAY MORNING. VERY WARM AND MOIST AIR LIFTING INTO THE
AREA AHEAD OF THE COLD FRONT WILL RESULT IN GOOD COVERAGE OF RAIN
SHOWERS THIS EVENING WITH ISOLATED THUNDERSTORMS POSSIBLE. MOST
LOCATIONS WILL RECEIVE AROUND 0.5 INCH OF RAIN BY THURSDAY MORNING
WITH ISOLATED TOTALS OF AROUND 1.0 INCH. LITTLE CONCERN FOR FLOODING
EXISTS.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ047>049-053>055-
060>063-068>070-075-076-082-083.
LAKE HURON...GALE WARNING UNTIL NOON EST TODAY FOR LHZ421-422-441-462.
GALE WARNING FROM 4 AM TO 10 AM EST THIS MORNING FOR LHZ442-443-463-
464.
GALE WARNING UNTIL 3 PM EST THIS AFTERNOON FOR LHZ361>363.
LAKE ST CLAIR...GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LEZ444.
&&
$$
AVIATION.....BT
UPDATE.......BT
DISCUSSION...DG/DT
MARINE.......DRK
HYDROLOGY....DRK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
953 PM CST FRI DEC 25 2015
.UPDATE...SHOWERS AND STORMS CONTINUE THIS EVENING ACROSS PORTIONS OF
THE AREA. LATEST HRRR INDICATES THE POTENTIAL FOR SOME ACTIVITY
THROUGH THE NIGHT...ESPECIALLY ACROSS NORTHERN ZONES. AS FOR THE
CURRENT FORECAST...ADJUSTED THE HOURLY TEMPS FOR THIS EVENING TO
ACCOUNT FOR THE LATEST TRENDS. ALSO ADJUSTED POPS LATER TONIGHT BASED
ON HRRR AND LATEST RADAR TRENDS. /27/
&&
.AVIATION...CONDITIONS WILL CONTINUE TO LOWER THROUGH THE COURSE
OF THE NIGHT WITH LIFR CIGS/VSBYS IN STRATUS/FOG AT ALL TAF SITES BY
26/08Z. THESE CONDITIONS WILL LINGER THROUGH 26/15Z...SLOWLY
IMPROVING THEREAFTER...BUT NOT GETTING ABOVE MVFR THROUGH THE END OF
THE PERIOD./26/
&&
.PREV DISCUSSION... /ISSUED 348 PM CST FRI DEC 25 2015/
SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)... LATEST SATELLITE
IMAGERY WAS PICKING UP A LARGE UPPER TROUGH OVER THE WESTERN
CONUS...WHICH WAS RESULTING IN DEEP SOUTH-SOUTHWESTERLY FLOW OVER
THE REGION. THE CONVECTIVE ACTIVITY WAS BEING ENHANCED BY A LOW
AMPLITUDE IMPULSE ABOUT TO EXIT THE MIDSOUTH REGION. THE DEEP
SOUTHERLY FLOW WAS BRINGING IN STRONG MOISTURE TRANSPORT IN STRONG
ISENTROPIC LIFT WITH ANOMALOUS PWATS IN THIS TROPICAL AIRMASS OF
AROUND 1.8 INCHES. THIS HAS RESULTED IN SOME FLASH FLOOD WARNINGS
ACROSS THE SOUTHWEST FOR THIS AFTERNOON. A STATIONARY FRONTAL
BOUNDARY WAS NOTED ACROSS THE DELTA REGION WITH TEMPS RANGING FROM
THE 60S NORTHWEST OF THE BOUNDARY TO THE 70S ON THE SOUTH SIDE. AREA
RADARS AT MID AFTERNOON HAD PICKED UP SOME STRONG STORMS WITH SOME
HEAVY RAINFALL. STILL HAD DEEP LAYER SHEAR, HELICITY AND SOME
INSTABILITY ACROSS THE REGION. EXPECT THE LIMITED SEVERE RISK TO
DECREASE AS WE PUSH INTO TONIGHT.
FOR TONIGHT MODELS SHOWS THE ACTIVITY TAPERING OFF AS WE MOVE INTO
AFTER MIDNIGHT. SO HAVE REDUCED POPS SOME AT THAT TIME. THERE MAY BE
SOME AREAS OF FOG THAT DEVELOP IN THE FAR SOUTH AFTER
MIDNIGHT...WHICH IS SHOWN BY SOME OF THE SHORT TERM GUIDANCE. WILL
KEEP THE FLASH FLOOD WATCH ACROSS THE NORTH UNTIL 12Z SATURDAY FOR
NOW. EXPECT THE FRONTAL BOUNDARY TO GET PUSHED BACK TO THE NORTH AS
A WARM FRONT AHEAD OF AN APPROACHING STORM SYSTEM BY EARLY SATURDAY.
THE FOG IN THE SOUTH SHOULD LIFT BY MIDMORNING. THE STORM SYSTEM
WILL BE NEAR THE FOUR CORNERS REGION ON SATURDAY. WARM MILD TEMPS
WILL CONTINUE THROUGH MOST OF THE SHORT TERM UNTIL WE GET TO SUNDAY
NIGHT WHEN LOWS WILL DIP INTO THE 50S WEST TO THE 60S EAST. AS WE
GET INTO SUNDAY AND SUNDAY NIGHT THE STORM SYSTEM TO THE WEST WILL
BE WINDING UP AS IT APPROACHES FROM THE ARKLATEX REGION. WE WILL GET
SOME GOOD HEIGHT FALLS AND ISENTROPIC LIFT WILL INCREASE ACROSS THE
ARKLAMISS FOR SUNDAY INTO SUNDAY NIGHT. ONCE AGAIN DEEP LAYER
MOISTURE TRANSPORT AND DEEP SHEAR WILL BUILD ACROSS THE REGION.
MODELS CONTINUE TO PROG A CUTOFF LOW DEVELOPING OVER THE SOUTHERN
PLAINS BY SUNDAY ALONG WITH A STRONG BAROCLINIC ZONE TO OUR WEST
WITH HIGH PWATS AROUND 1.9 INCHES. ONCE AGAIN WE COULD BE SOME
EFFICIENT RAINFALL RATES WITH THIS SYSTEM ESP WITH TRAINING OF CELLS
ONCE AGAIN FOR SOME FLASH FLOODING ISSUES...HOWEVER SEVERE WEATHER
WILL BE THE PRIMARY CONCERN FOR SUNDAY NIGHT INTO MONDAY. MODELS
CONTINUE TO SHOW THAT A SQUALL LINE WILL PUSH ACROSS THE REGION FOR
SUNDAY NIGHT INTO EARLY MONDAY. THE PRIMARY RISK WILL BE DAMAGING
WINDS AND SOME POSSIBLE TORNADOES. MODELS PROG A DEEPENING SURFACE
LOW PUSHING ACROSS NORTHWEST ARKANSAS ON SUNDAY NIGHT INTO EARLY
MONDAY.
LONG TERM...MONDAY THROUGH FRIDAY...DRY SLOTTING SHOULD END MOST OF
THE SIGNIFICANT RAIN BY NOON MONDAY BUT PCPN WL REMAIN POSSIBLE
UNTIL THE CLOSED LOW MOVES A LITTLE FARTHER NORTH MONDAY EVENING.
COOLER AND MUCH DRIER AIR IS EXPECTED TO BE BACK OVER OUR CWA
TUESDAY. TUESDAY MORNING LOWS WILL BE BACK MAINLY IN THE 40S WITH
HIGHS TUESDAY MOSTLY IN THE 50S. TUESDAY WILL BE DRY AS THE CLOSED
LOW SYSTEM TRACKS FARTHER NORTHEAST OF OUR CWA BUT OUR WINDS ALOFT
WILL BACK TO THE SOUTHWEST AHEAD OF A SECOND CLOSED LOW SWINGING
OVER THE DESERT SOUTHWEST. THE GFS AND ECMWF ARE IN A LITTLE BETTER
AGREEMENT AND OPEN THE LOW AND SWINGS A TROUGH ACROSS THE CENTRAL
CONUS WEDNESDAY. THE EURO WAS A LITTLE HEAVIER WITH THE PRECIP
AMOUNTS AT MIDWEEK. THURSDAY AND FRIDAY WILL BE COOL AND DRY ACROSS
OUR REGION./17/22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 67 79 69 77 / 42 25 24 35
MERIDIAN 66 77 67 76 / 40 26 27 32
VICKSBURG 69 80 69 77 / 42 20 21 43
HATTIESBURG 69 78 68 78 / 29 30 34 36
NATCHEZ 70 80 71 77 / 38 22 22 48
GREENVILLE 60 79 68 76 / 57 26 22 69
GREENWOOD 65 79 70 76 / 59 25 22 44
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...FLASH FLOOD WATCH UNTIL 6 AM CST SATURDAY FOR MSZ018-019-025>039.
LA...NONE.
AR...FLASH FLOOD WATCH UNTIL 6 AM CST SATURDAY FOR ARZ074-075.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
825 PM CST FRI DEC 25 2015
.UPDATE:
Issued at 825 PM CST Fri Dec 25 2015
Very little change made to the forecast other than to tweak sky
cover. After examining the 00z NAM and most recent HRRR and RAP
versus current satellite and radar trends, we still anticipate the
currently pcpn echo-free radar to rapidly fill in for most of our
forecast area late tonight and Saturday morning, of which trends
were handled well by the previous forecast.
Temps will likely bottom out and hit their min values this evening
with a slow rise overnight as clouds thicken and dewpoints rise.
TES
&&
.SHORT TERM: (Through Late Tonight)
Issued at 335 PM CST Fri Dec 25 2015
Currently experiencing the calm before the storm across the CWA
with high pressure to our north bringing tranquil conditions and
above average temperatures. Main activity at this time is the
frontal boundary draped from the TN Valley into lower MS Valley.
All indications are that fall heights and surface pressure tonight
across the high Plains along with the eastward retreat of the
surface high to our north will allow for a sizable response in
the atmosphere. Low level flow above the boundary layer is
forecast to veer and strengthen, with a veering 30-40+ kt south-
southwesterly LLJ transporting anomalously deep moisture northward
into the area while the surface boundary gradually retreats
northward as well. Precipitation should develop in response
although it appears to be delayed until overnight. The best threat
appears to be after 08-09z when elevated showers and thunderstorms
are expected primarily south of I-70 across southern MO into SW
IL.
Glass
.LONG TERM: (Saturday through Next Friday)
Issued at 335 PM CST Fri Dec 25 2015
...Very Serious-High Impact and Potentially Historic Heavy Rain/Flood
Event Likely Saturday Afternoon into Monday...
High Points...
Confidence is growing and high at this point in time that a very
serious high-impact and potentially historic heavy rain/flood
event will occur in the Saturday night into Monday. This event
will feature life-threatening flash flooding on creeks/streams and
poor drainage areas, and major to historic flooding on area
rivers. The Meramec River is a huge concern.
Widespread area average storm total rainfall is now forecast in the
5-8 inch range across the southeast half of the CWA. The Bullseye
for heaviest rainfall would be late Saturday afternoon and Saturday
night with embedded convection/high rainfall rates and training,
however this will also be a prolonged event lasting well into
Monday. A flash flood watch is already in place and we have now
expanded it northward some to account for greater northward spread
of significant precipitation during the event.
Discussion...
The rapid evolution and expansion of a wide wsw-ene oriented band
of rain and thunderstorms is expected on Saturday along and north
of the lifting frontal zone. This will be in response to strong
deep layer ascent associated with a 40+ s/swly LLJ, disturbances
with the SW flow aloft and divergence aloft within the entrance
region of an anticyclonically curved ULJ. All the models have a
strong signal just differ some on the boundary location. Prefer
a blend of the GFS/ECMWF with this aspect and QPF placement with
the front near the I-44 corridor in MO and I-70 in IL at 00z
Sunday, feeling the NAM is too far north lifting the boundary
into cooler air.
The worst of this prolonged event appears to have a bullseye on
late Saturday afternoon into Saturday night. PWs are forecast to
exceed 1.5 inches which is 5 standard deviations above normal!
Strong deep layer ascent is focused in a broad region along and
north of the surface front resulting from frontogenesis, low level
MCON/lift, upper level disturbances and the ULJ entrance region.
This focused elongated forcing and flow aloft parallel to the
frontal zone favors training with elevated instability supporting
embedded convection. Along and south of the frontal zone there
could also be a few severe storms Saturday afternoon and evening.
The front then sags southeastward late Saturday night and this
will shift some of the focus of the axis of heaviest rainfall on
Sunday to the southeast third of the CWA. Finally late Sunday into
Monday will be the last aspect of the event as a strong closed upper
low and the associated vertically stacked system lifts north/northeast
through the MS Valley. This will lead a renewed northward spread
in rain, although rates appear lower with this round. While there
are differences in the system track, the most favored is a
western track which would largely keep any wintry precipitation at
bay to the west, with some chance of snow Monday night across
northeast and central MO in the cyclonic flow/CAA in the wake of
the departing system.
Glass
&&
.AVIATION: (For the 00z TAFs through 00z Saturday Evening)
Issued at 617 PM CST Fri Dec 25 2015
VFR for the first 0-6 hours until MVFR clouds spread across the
area ahead of an approaching low pressure system. This system will
bring a prolonged period of rain and reduced cigs/vsbys to all
TAF sites. Moderate rain and IFR cigs are expected after 12-15z.
Embedded thunderstorms are also possible, especially after 26/18z.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...Flash Flood Watch from Saturday afternoon through Monday
afternoon FOR Audrain MO-Boone MO-Callaway MO-Cole MO-
Crawford MO-Franklin MO-Gasconade MO-Iron MO-Jefferson MO-
Lincoln MO-Madison MO-Moniteau MO-Monroe MO-Montgomery MO-
Osage MO-Pike MO-Ralls MO-Reynolds MO-St. Charles MO-St.
Francois MO-St. Louis City MO-St. Louis MO-Ste. Genevieve
MO-Warren MO-Washington MO.
IL...Flash Flood Watch from Saturday afternoon through Monday
afternoon FOR Bond IL-Calhoun IL-Clinton IL-Fayette IL-
Greene IL-Jersey IL-Macoupin IL-Madison IL-Marion IL-Monroe
IL-Montgomery IL-Pike IL-Randolph IL-St. Clair IL-
Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
343 PM CST THU DEC 24 2015
.SHORT TERM: (Through Late Tonight)
Issued at 342 PM CST Thu Dec 24 2015
Low-mid level WAA and MCON along with frontogenetic forcing resulted
in an elongated region of light rain earlier today across central
and northeast MO. This regime is occurring in advance of a low-
amplitude disturbance which is dampening and now located in western
MO. Overall forcing has diminished and shifted to the northeast of
the CWA and only a narrow elongated ribbon of light rain still
persists in west central IL. Present indications is this will also
diminish and shift to the northeast the remainder of the afternoon
and early evening as the disturbance aloft and associated surface
cold front push east. There are some indications in the HRRR and GFS
that a new narrow band of precipitation may try to develop this
evening somewhere in the SE/EC MO into SW IL region in response to a
new region of low level MCON. I have add a slight chance of light
rain in SW IL this evening to account for this and some sprinkles
further west. Otherwise expecting several waves of clouds tonight
with current mid clouds and maybe a period of low clouds up north.
SREF probs and HRRR also suggesting some potential for fog from
across northern/central MO into western IL overnight. I added a
mention of patchy fog in this region, but the overall pattern in
post-frontal air mass with building surface high pressure is at
first glance not one typically associated with alot of fog.
Glass
.LONG TERM: (Friday through Next Thursday)
Issued at 342 PM CST Thu Dec 24 2015
(Friday)
Overall, it looks like a fairly tranquil Christmas Day across the
area. Models continue to hint at WAA along the stalled frontal
boundary to our south generating an axis of convection from AR into
the lower Ohio Valley, with our far southern counties on the very
northern fringes of this activity. The 12z solutions have the axis
of this activity just south of our ara, but since the last few model
cycles have wobbled a bit with the north/south placement of this
precip, I`ve maintained some very low PoPs over our far southern
counties.
Otherwise, it still appears tranquil conditions are on tap for the
region, with temperatures maintaining the very mild levels that have
been commonplace this December. Highs are expected to range from
the middle and upper 40s northwest, to the middle 50s southeast.
Concern then turns to the long-advertised heavy rain threat for the
upcoming weekend and into early next week. Due to some uncertainty
to the placement of the heaviest rain have opted not to go with any
hydro headlines...yet. However, will be reissuing the EFP to
maintain awareness of the threat, which should come in two waves as
described below.
(Saturday Through Monday Night)
The long-advertised spell of wet weather should commence in earnest
either late Friday night or Saturday. Deep southerly flow is
expected to develop across the region in response to the upper level
system digging into the southwest US, and resultant isentropic
ascent over the area should be quite strong with the stalled frontal
boundary and low level baroclinic zone just to our south. In
addition, UVV across the area will be enhance by several weak
shortwaves ejecting ahead of the main system. Moisture should be no
problem as airmass will essentially be the same one that fueled
yesterdays storms in our area, with the increasing southerly flow
adding even more moisture to the unseasonably moist December
airmass. Again, models are wobbling a bit with the exact location of
the axis of the heaviest precip, but they are in excellent agreement
with the general idea that several rounds of convection will track
along and north of the frontal boundary as it attemps to push
north...from eastern OK into s MO and s IL...in the Saturday and
Saturday night time.
It appears that this first round of significant rain will wind down
on Sunday as shortwave in the northern branch of the westerlies
allows Canadian high to drop south, temporarily shutting down the
warm advection and nudging the frontal boundary back south.
Final wave of potentially heavy rain should impact the region on
Monday and Monday night as upper level low lifts out of Texas and
pushes northeast into the mid-Mississippi Valley. Again, moisture-
laden AMS ans strong UVV should produce another band of moderate to
occasionally heavy rain...with embedded thunderstorms...that will
sweep across the area.
It`s not totally out of the question that we could see a bit of
wintry precip Sunday night-Monday night. First concern will be late
Sunday night and into early Monday as surface temps drop below
freezing with the southward surge of the Canadian high...while AMS
aloft remains well above freezing. This threat should be brief and
on the northern fringes of the heavier rainfall...and with the very
warm ground temperatures am not expecting much of an impact from
this. The second concern will be Monday night as the upper low
pushes across the area. It`s possible that the dropping freezing
levels beneath the low could cause the rain to change over to snow,
but not certain if the lower levels will cool enough for any
prolonged period of significant nowfall.
(Tuesday-Thursday)
Medium range progs suggest long wave trof will be parked over the
central CONUS during this time frame. This will finally allow
Canadian air to dominate the region, which should yield more normal
typical wintertime temperatures.
Best holiday wishes to all...from the day shift of the National
Weather Service in St. Louis.
Truett
&&
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1147 AM CST Thu Dec 24 2015
VFR flight conditions are expected to dominate the terminals
through the forecast period. An area of light rain which moved
through central MO this morning impacting KCOU, will continue to
the northeast and weaken and may bring KUIN some sprinkles.
Otherwise mid-high clouds will largely dominate with winds
veering tonight with the approach and passage of a weak surface
cold front. Some of our guidance suggests good IFR or lower fog
potential in central and northeast MO and west central IL
overnight into early Friday morning, and thus added a tempo group
for MVFR conditions given only marginal confidence.
Specifics for KSTL:
VFR flight conditions are expected to dominate through the
forecast period. Mid-high clouds will largely dominate with winds
veering tonight with the approach and passage of a weak surface
cold front. Can`t rule out some sprinkles this evening but
confidence is not great enough to include any mention.
Glass
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 39 54 47 63 / 10 10 50 100
Quincy 32 48 42 54 / 10 5 20 70
Columbia 33 52 45 59 / 5 10 60 80
Jefferson City 33 53 46 60 / 5 10 70 80
Salem 40 56 49 64 / 20 20 50 90
Farmington 39 54 49 64 / 20 20 60 100
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
528 PM CST FRI DEC 25 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 258 PM CST FRI DEC 25 2015
STORM SYSTEM TO AFFECT THE AREA IS ON TRACK FOR TONIGHT INTO
SATURDAY. LATE THIS AFTERNOON...WATER VAPOR IMAGERY INDICATES THE PV
ANOMALY LOCATED OVER GRAND JUNCTION IN WESTERN COLORADO. MODELS
AGREE THAT THE ANOMALY WILL MOVE EAST-NORTHEAST INTO WESTERN
NEBRASKA THIS EVENING. A STRONG JET STREAK WILL MOVE NORTHEAST
ACROSS KANSAS INTO EASTERN NEBRASKA AHEAD OF THE SYSTEM TONIGHT. A
CROSS SECTION FROM NORTHWEST TO SOUTHEAST ACROSS THE REGION SHOWS A
CLASSIC AGEOSTROPHIC RESPONSE AS THE JET STREAK MOVES ACROSS...WITH
DEEP LIFT ACROSS MOST OF THE AREA. CONCERNS WITH SATURATION IN THE
MID LEVELS OF THE ATMOSPHERE ACROSS SOUTHWEST INTO PORTIONS OF
CENTRAL NEBRASKA...BUT THAT WILL NOT BE AN ISSUE ACROSS THE
PANHANDLE INTO NORTH CENTRAL NEBRASKA.
SNOW SHOULD INCREASE RAPIDLY ACROSS THE PANHANDLE INTO NORTH CENTRAL
NEBRASKA TONIGHT...AND CURRENT HEADLINES FOR WINTER WEATHER ADVISORY
AND WINTER STORM WARNING LOOK GOOD. DID EXPAND THE WARNING INTO BOYD
COUNTY...BUT OTHERWISE NO CHANGES.
AS MENTIONED MID LEVEL DRY AIR WILL ADVECT INTO SOUTHWEST AND
CENTRAL NEBRASKA...SO NOT EXPECTING AS MUCH SNOW IN THESE AREAS.
COULD HAVE SOME LIGHT FREEZING DRIZZLE HOWEVER.
SATURDAY MORNING A STRONG ARCTIC COLD FRONT WILL MOVE SOUTH THROUGH
THE AREA. H850MB WINDS INCREASE THROUGH THE DAY TO AROUND 45 KTS BY
AFTERNOON. BLOWING SNOW WILL LIKELY BE AN ISSUE ACROSS NORTH CENTRAL
NEBRASKA AND INTO THE PANHANDLE...AS NORTH WIND GUSTS OVER 30 MPH
ARE LIKELY. OTHERWISE FALLING TEMPERATURES THROUGH THE TEENS
EXPECTED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 258 PM CST FRI DEC 25 2015
VERY COLD TEMPERATURES ARE LIKELY BY SUNDAY MORNING WITH LOWS IN THE
SINGLE DIGITS ABOVE ZERO CENTRAL AND SOUTHWEST NEBRASKA AND THE
SINGLE DIGITS BELOW ZERO IN THE NORTHERN SANDHILLS AND THE NEBRASKA
PANHANDLE. COMPARABLE TEMPERATURES ARE EXPECTED AGAIN SUNDAY NIGHT
AND EARLY MONDAY.
THERE IS STILL CONSIDERABLE UNCERTAINTY REGARDING THE IMPACT OF THE
MONDAY-TUESDAY SYSTEM ON CENTRAL AND WESTERN NEBRASKA. THE NAM12 IS
ABOUT 4 DEGREES LONGITUDE FARTHER WEST THAN THE GFS40 WITH THE TRACK
OF THE CYCLONE. THIS DIFFERENCE IS SIGNIFICANT WITH THE MORE
WESTERLY TRACK GIVING ISENTROPIC UPGLIDE OVER THE COLD DOME REACHING
THE NEBRASKA SANDHILLS WHILE THE MORE EASTERLY TRACK LEAVING CENTRAL
AND WESTERN NEBRASKA OUT OF THE PRECIPITATION COMPLETELY. ACCOUNTING
FOR THE UNCERTAINTY...WE WILL KEEP THE PROBABILITY LOW. AGAIN...
SIGNIFICANT DIFFERENCES IN THE EXTENDED SOLUTIONS CONTINUE EVEN
THROUGH TUESDAY NIGHT. THE ECMWF TAKES THE CYCLONE ALMOST DUE NORTH
INTO NORTHERN IOWA BEFORE TURNING IT EAST. AS A RESULT...SOME CHANCE
OF SNOWFALL WILL CONTINUE UNTIL TUESDAY EVENING IN NORTHERN
NEBRASKA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 528 PM CST FRI DEC 25 2015
IFR/LIFR IN SNOW AND LOW CIGS ARE EXPECTED TONIGHT THROUGH 15Z
SATURDAY...MAINLY NORTH OF INTERSTATE 80 TO THE SD BORDER.
MVFR/VFR CIGS ARE EXPECTED SATURDAY. THE MVFR IS MOST LIKELY ALONG
AND NORTH OF HIGHWAY 20.
CONFIDENCE IS GOOD AND THE RAP AND NAM MODELS WERE THE BASIS FOR
THE FORECAST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 PM CST /5 PM MST/ SATURDAY FOR
NEZ004>007-094.
WINTER WEATHER ADVISORY UNTIL 6 PM CST /5 PM MST/ SATURDAY FOR
NEZ008>010-022>029-035>038-056-057-059.
&&
$$
SHORT TERM...TAYLOR
LONG TERM...SPRINGER
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1137 AM CST THU DEC 24 2015
.UPDATE...
ISSUED AT 1128 AM CST THU DEC 24 2015
STRONGEST RADAR RETURNS HAVE BEEN GRADUALLY DECREASING IN
INTENSITY AS THEY SHIFT ACROSS THE MISSOURI RIVER BETWEEN 1030 AND
1130 AM. HOWEVER MODERATE SNOWS WERE STILL FALLING ACROSS THE
OMAHA METRO AND INTO SARPY COUNTY NEAR GRETNA AND BELLEVUE.
REPORTS OF 6 INCHES OF SNOW HAVE BEEN COMMON ACROSS THE METRO FROM
SAUNDERS COUNTY INTO DOUGLAS/SARPY...WITH SOME AS HIGH AS 8
INCHES. COULD SEE ANOTHER INCH OR SO WEST OF THE MISSOURI RIVER
BEFORE BACK EDGE TO MODERATE SNOW MOVES EAST EARLY THIS AFTERNOON.
EAST OF THE RIVER...CONTINUED SNOWS IN POTTAWATTAMIE...HARRISON
AND SHELBY COUNTIES WILL ACCUMULATE AN INCH OR MORE AN HOUR EARLY
THIS AFTERNOON...BUT WITH INTENSITY TRENDS ON THE DOWNWARD
SLIDE...EXPECT TOTALS THERE TO REMAIN GENERALLY NEAR OR UNDER 5
INCHES. WILL LIKELY LET WINTER WEATHER ADVISORIES EXPIRE WEST OF
THE METRO AS SCHEDULED AT NOON...AND LET THE ADVISORY FROM OMAHA
AND EAST CONTINUE INTO MID AFTERNOON.
UPDATE ISSUED AT 932 AM CST THU DEC 24 2015
930 AM SNOW TOTAL AT THE VALLEY WEATHER OFFICE IS 3.8 INCHES AND
STILL COMING DOWN NICELY.
RADAR TRENDS HAVE HIGHEST REFLECTIVITIES FROM SOUTHEAST SAUNDERS
THROUGH NORTHERN SARPY...ALL OF DOUGLAS AND INTO NORTHERN
POTTAWATTAMIE COUNTIES AS OF 930 AM. EXPECT THIS HEAVIEST BAND TO
GRADUALLY WORK EAST OF THE MISSOURI RIVER THROUGH 11 AM WITH A
MARKED DECLINE IN ACTIVITY IN NEBRASKA COUNTIES BY NOON OR SO.
LATEST HRRR FORECASTS BEAR THIS OUT...BUT SNOWFALL OF AN PER HOUR
UNTIL THEN WILL PUT SNOW TOTALS INTO THE 5 TO 6 INCH RANGE FOR
PARTS OF THE OMAHA AND COUNCIL BLUFFS METRO. HAVE UPDATED OUR
FORECAST TO REFLECT THIS.
UPDATE ISSUED AT 844 AM CST THU DEC 24 2015
SNOW CONTINUES OVER MUCH OF EASTERN NEBRASKA AND SOUTHWEST IOWA.
RADAR TRENDS OVER THE LAST HOUR OR SO SHOW MOST INTENSE SNOWFALL
OCCURRING FROM THE NORTH SIDE OF LINCOLN TO OMAHA AND COUNCIL
BLUFFS. MULTIPLE REPORTS OF 2 INCH ACCUMULATIONS FROM LINCOLN TO
OMAHA AS OF 830 AM. ANOTHER 2 INCHES ARE LIKELY IN THE HEAVIEST
BANDS THROUGH 11 AM OR SO. ALREADY SEEING SNOW ENDING IN SOUTH
CENTRAL NEBRASKA JUST WEST OF FAIRBURY AND YORK...AND TOTAL
SNOWFALL OF 3.5 INCHES WERE RECEIVED IN PARTS OF THOSE AREAS. SO
WOULD EXPECT TOTALS HERE TO REACH THAT 3 TO 4 INCH RANGE RATHER
EASILY...WITH LESSER AMOUNTS CLOSER TO AN INCH BY NORFOLK ON
FRINGE OF SNOW BAND...AND IN FAR SOUTHEAST NEBRASKA AND FAR
SOUTHWEST IOWA WHERE TEMPERATURES ARE AT OR ABOVE FREEZING AND
SOME RAIN/SLEET IS MIXING IN.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
...SNOW THROUGH EARLY AFTERNOON...WARMER FOR CHRISTMAS DAY WITH
SNOW FOR NORTHEAST NEBRASKA...
FORECAST CONCERNS FOR TODAY WILL BE FAST-MOVING STORM SYSTEM AND HOW
MUCH SNOW WILL FALL...SPOTTY PRECIPITATION POTENTIAL
CHRISTMAS...THEN EXPANDING PRECIPITATION AREA CHRISTMAS NIGHT INTO
SATURDAY NIGHT WITH ACCUMULATING SNOW/MIX FOR PARTS OF NORTHEAST
NEBRASKA.
THE 00Z OAX SOUNDING HAD DRIED OUT WITH 0.25 PWAT. A LOOK TO THE
WEST AND KLBF HAD PWAT OF 0.20...HOWEVER WAS SATURATED AT 6KFT WITH
TEMPERATURES IN THE DENDRITIC LAYER OF -11 TO -15DEG C.
ON THE H3 CHART...THE 100-140KT STRETCHED FROM NORTHERN CALIFORNIA
ACROSS THE SOUTHERN PLAINS...TURNING NORTH INTO ILLINOIS AND WI.
BROAD TROF WITH EMBEDDED SHORTWAVES STILL DOMINATED THE MID
TROPOSPHERIC FLOW. THE APPROACHING SHORTWAVE AT 06Z EXTENDED FROM
WYOMING ACROSS COLORADO INTO NEW MEXICO. 40M HEIGHT FALLS WERE
ASSOCIATED WITH THIS FEATURE. LIGHTNING STRIKES WERE NOTED WITH
FROM SOUTHEAST UTAH THROUGH COLORADO INTO NEW MEXICO DURING THE
EVENING AND IN NORTHWEST KANSAS AROUND 06Z. AT H7 COLD
TEMPERATURES WERE OBSERVED...HOWEVER THE H85 THERMAL TROUGH WAS
OVER OAX AND TOP...WITH WARMER H85 TEMPERATURES OVER WESTERN
KANSAS. H85 MOISTURE WAS RETURNING TO THE ROCKIES ACROSS MEXICO
INTO ARIZONA/NEW MEXICO AND SOUTHWEST COLORADO.
AT 05Z THERE WAS 2-STAR SNOW IN NORTHEAST COLORADO AND 3-STAR SNOW
IN NORTHWEST KANSAS WITH SOME LIGHTNING. AT 0930Z THE WSR-88D
RADAR MOSAIC SHOWED SNOW SPREADING NORTHEAST WITH RETURNS AS CLOSE
AT ALBION BY 10Z AND THE STRONGER RETURNS OVER NORTH CENTRAL
KANSAS AND SOUTH CENTRAL NEBRASKA.
THROUGH 12Z...THE H3 JET IS FORECAST TO STRENGTHEN TO 150KTS OVER
INDIANA. THIS JET COMBINED WITH A RIPPLE IN THE JET OVER COLORADO
HAS A SMALL AREA OF ENHANCED UPPER LEVEL DIVERGENCE WHICH PUSHES
ACROSS THE FORECAST AREA THROUGH 18Z AND ACROSS IOWA DURING THE
AFTERNOON. UPWARD VERTICAL MOTION INCREASES ACROSS CENTRAL
NEBRASKA THROUGH 12Z AND THE FORECAST AREA THIS MORNING. FAVORABLE
MID LEVEL WARM ADVECTION AND THETA-E ADVECTION INCREASE AS WELL.
THE LIFT TODAY HAS VERY FAVORABLE TEMPERATURES AS GOOD SATURATION TO
WORK WITH...SO SHOULD BE EFFICIENT WITH THE SNOW PRODUCTION AND
VISIBILITIES DROPPING DOWN TO LESS THAN A MILE. THE 00Z RUNS OF
THE NAM/GFS HAVE 2 TO 4 INCHES OF SNOW AT OMAHA USING THE COBB
METHOD AND MOST MODELS NOW HAVE BETWEEN 1 AND 4 INCHES ACROSS
PARTS OF THE CWA. THE LOW LEVEL JET IS STRONGER ACROSS
KANSAS/MISSOURI/OKLAHOMA AND THERE ARE MORE RETURNS IN KANSAS THAN
THE MODELS HAVE. THE 06Z NAM IS ABOUT 1 COUNTY FARTHER SOUTH WITH
THE HIGHER SNOW AMOUNTS...HOWEVER THE LATEST HRRR EXP HAS THE
HIGHER SNOW TRACK SLIGHTLY NORTH. SHORT MET WATCH WILL HAVE THE
BEST HANDLE ON WHERE THE HEAVIER AMOUNTS WILL FALL. OUR CURRENT
FORECAST HAS HIGHEST AMOUNTS RIGHT THROUGH EAST CENTRAL NEBRASKA
INTO WESTERN IOWA. WITH THE SNOW COMING IN DURING THE EARLY/MID
MORNING COMMUTE AND LASTING THROUGH LUNCH. AMOUNTS OF 1 TO 4
INCHES ARE EXPECTED SO DECIDED TO ISSUE A WINTER WEATHER
ADVISORY. HOLIDAY TRAVEL IS ALSO ONGOING...ALTHOUGH SOME OF THE
TRAVEL SHOULD ACTUALLY BE LIGHTER WITH SCHOOLS ON BREAK AND PEOPLE
ON HOLIDAY. THE SNOW WILL END FROM WEST TO EAST...AND SHOULD BE
EAST OF THE AREA BY MID AFTERNOON. HIGHS TODAY SHOULD MOSTLY BE IN
THE LOWER TO MID 30S...HOWEVER WARMER HIGHS AROUND 40 OR THE LOWER
40S COULD BE REACHED NEAR THE KANSAS BORDER. THE WINDS SHOULD NOT
BE AN ISSUE...MOSTLY UNDER 10 MPH.
THERE IS A BREAK FOR TONIGHT AND ALREADY ON CHRISTMAS DAY...THERE IS
SOME WEAK ENERGY PUSHING INTO THE PLAINS AHEAD OF TROUGH OVER THE
ROCKIES/SIERRAS. CLOUDS AND SOME SNOW/MIX CHANCES...ESPECIALLY IN
PARTS OF NORTHEAST NEBRASKA AND AREAS FARTHER WEST. CHRISTMAS
NIGHT...THE BRUNT OF THE SNOW IS ACROSS SOUTH DAKOTA AND
MINNESOTA...AND CLIPS PARTS OF NORTHEAST NEBRASKA AND NORTHWEST
IOWA WITH ACCUMULATING SNOW. SPOTTY RAIN/MIX WILL BE POSSIBLE
ACROSS PARTS OF THE REST OF THE CWA. SATURDAY...THE COLD AIR MOVES
FARTHER SOUTH AND WILL CONTINUE TO MENTION SNOW/MIX/RAIN...HOWEVER
ANY ACCUMULATIONS APPEAR SLIGHT...EXPECT NORTHEAST NEBRASKA COULD
SEE MORE ACCUMULATIONS. SATURDAY NIGHT...THE EC IS DRY...HOWEVER
THE NAM/SREF/GEM STILL LINGER SOME LIGHT SNOW IN THE EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
THE GFS/EC START OUT THE EXTENDED IN GOOD AGREEMENT WITH CLOSED
H5 LOW PRESSURE OVER SOUTHWEST TX INTO MEXICO...EXTENDING THE
TROUGH NORTHWARD ACROSS PARTS OF NEBRASKA INTO THE GREAT LAKES.
HOWEVER...BY MONDAY THERE ARE HUGE DIFFERENCES...THE EC IS FARTHER
NORTH WITH THE TRACK OF THE H5 LOW INTO NORTHERN TEXAS WHILE THE
GFS IS SOUTH. WILL TREND WITH THE EC AND MAINTAIN POPS MONDAY AND
MONDAY NIGHT. SHOULD THE EC WIN OUT...COULD BE SIGNIFICANT SNOW
ACCUMULATIONS FOR PARTS OF THE FORECAST AREA...WHILE THE GFS
MISSES US. SOUTHWEST IOWA COULD SEE A MIX IF THIS TRACK HOLDS...
OTHERWISE...WE ARE MAINLY ON THE COLD SIDE OF THE STORM SYSTEM. BY
WEDNESDAY...THE BULK OF THE STORM SYSTEM IS TO OUR NORTH AND EAST.
COULD BE SOME WRAP-AROUND...THEN WE ARE DRY WEDNESDAY NIGHT AND
THURSDAY. LOOK FOR AT OR BELOW NORMAL TEMPERATURES SUNDAY THROUGH
THURSDAY.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1128 AM CST THU DEC 24 2015
MODERATE SNOWS NEAR KOMA WILL GRADUALLY END EARLY IN THE TAF
PERIOD...ALLOWING VSBYS TO IMPROVE MARKEDLY BY 20Z. CIGS WILL ALSO
LIFT TO MVFR WITH SNOW ENDING AT ALL TAF SITES. A GRADUAL
IMPROVEMENT IN CIGS WILL TO VFR IS EXPECTED BY 00Z AT ALL EASTERN
NEBRASKA TAF SITES. HOWEVER LIGHT WINDS AND CLEARING SKIES
COMBINED WITH FRESH SNOW COVER WILL LIKELY LEAD TO AREAS OF FOG
LATER TONIGHT...ESPECIALLY AT KOMA AND KLNK WHERE VSBYS COULD
EASILY DROP TO BELOW A MILE AFTER 06Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR NEZ034-
045-052-053-067.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NEZ044-050-051-
065-066-078.
IA...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR IAZ043-
055-056-069-079.
&&
$$
UPDATE...DERGAN
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
940 AM CST THU DEC 24 2015
.UPDATE...
ISSUED AT 932 AM CST THU DEC 24 2015
930 AM SNOW TOTAL AT THE VALLEY WEATHER OFFICE IS 3.8 INCHES AND
STILL COMING DOWN NICELY.
RADAR TRENDS HAVE HIGHEST REFLECTIVITIES FROM SOUTHEAST SAUNDERS
THROUGH NORTHERN SARPY...ALL OF DOUGLAS AND INTO NORTHERN
POTTAWATTAMIE COUNTIES AS OF 930 AM. EXPECT THIS HEAVIEST BAND TO
GRADUALLY WORK EAST OF THE MISSOURI RIVER THROUGH 11 AM WITH A
MARKED DECLINE IN ACTIVITY IN NEBRASKA COUNTIES BY NOON OR SO.
LATEST HRRR FORECASTS BEAR THIS OUT...BUT SNOWFALL OF AN PER HOUR
UNTIL THEN WILL PUT SNOW TOTALS INTO THE 5 TO 6 INCH RANGE FOR
PARTS OF THE OMAHA AND COUNCIL BLUFFS METRO. HAVE UPDATED OUR
FORECAST TO REFLECT THIS.
UPDATE ISSUED AT 844 AM CST THU DEC 24 2015
SNOW CONTINUES OVER MUCH OF EASTERN NEBRASKA AND SOUTHWEST IOWA.
RADAR TRENDS OVER THE LAST HOUR OR SO SHOW MOST INTENSE SNOWFALL
OCCURRING FROM THE NORTH SIDE OF LINCOLN TO OMAHA AND COUNCIL
BLUFFS. MULTIPLE REPORTS OF 2 INCH ACCUMULATIONS FROM LINCOLN TO
OMAHA AS OF 830 AM. ANOTHER 2 INCHES ARE LIKELY IN THE HEAVIEST
BANDS THROUGH 11 AM OR SO. ALREADY SEEING SNOW ENDING IN SOUTH
CENTRAL NEBRASKA JUST WEST OF FAIRBURY AND YORK...AND TOTAL
SNOWFALL OF 3.5 INCHES WERE RECEIVED IN PARTS OF THOSE AREAS. SO
WOULD EXPECT TOTALS HERE TO REACH THAT 3 TO 4 INCH RANGE RATHER
EASILY...WITH LESSER AMOUNTS CLOSER TO AN INCH BY NORFOLK ON
FRINGE OF SNOW BAND...AND IN FAR SOUTHEAST NEBRASKA AND FAR
SOUTHWEST IOWA WHERE TEMPERATURES ARE AT OR ABOVE FREEZING AND
SOME RAIN/SLEET IS MIXING IN.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
...SNOW THROUGH EARLY AFTERNOON...WARMER FOR CHRISTMAS DAY WITH
SNOW FOR NORTHEAST NEBRASKA...
FORECAST CONCERNS FOR TODAY WILL BE FAST-MOVING STORM SYSTEM AND HOW
MUCH SNOW WILL FALL...SPOTTY PRECIPITATION POTENTIAL
CHRISTMAS...THEN EXPANDING PRECIPITATION AREA CHRISTMAS NIGHT INTO
SATURDAY NIGHT WITH ACCUMULATING SNOW/MIX FOR PARTS OF NORTHEAST
NEBRASKA.
THE 00Z OAX SOUNDING HAD DRIED OUT WITH 0.25 PWAT. A LOOK TO THE
WEST AND KLBF HAD PWAT OF 0.20...HOWEVER WAS SATURATED AT 6KFT WITH
TEMPERATURES IN THE DENDRITIC LAYER OF -11 TO -15DEG C.
ON THE H3 CHART...THE 100-140KT STRETCHED FROM NORTHERN CALIFORNIA
ACROSS THE SOUTHERN PLAINS...TURNING NORTH INTO ILLINOIS AND WI.
BROAD TROF WITH EMBEDDED SHORTWAVES STILL DOMINATED THE MID
TROPOSPHERIC FLOW. THE APPROACHING SHORTWAVE AT 06Z EXTENDED FROM
WYOMING ACROSS COLORADO INTO NEW MEXICO. 40M HEIGHT FALLS WERE
ASSOCIATED WITH THIS FEATURE. LIGHTNING STRIKES WERE NOTED WITH
FROM SOUTHEAST UTAH THROUGH COLORADO INTO NEW MEXICO DURING THE
EVENING AND IN NORTHWEST KANSAS AROUND 06Z. AT H7 COLD
TEMPERATURES WERE OBSERVED...HOWEVER THE H85 THERMAL TROUGH WAS
OVER OAX AND TOP...WITH WARMER H85 TEMPERATURES OVER WESTERN
KANSAS. H85 MOISTURE WAS RETURNING TO THE ROCKIES ACROSS MEXICO
INTO ARIZONA/NEW MEXICO AND SOUTHWEST COLORADO.
AT 05Z THERE WAS 2-STAR SNOW IN NORTHEAST COLORADO AND 3-STAR SNOW
IN NORTHWEST KANSAS WITH SOME LIGHTNING. AT 0930Z THE WSR-88D
RADAR MOSAIC SHOWED SNOW SPREADING NORTHEAST WITH RETURNS AS CLOSE
AT ALBION BY 10Z AND THE STRONGER RETURNS OVER NORTH CENTRAL
KANSAS AND SOUTH CENTRAL NEBRASKA.
THROUGH 12Z...THE H3 JET IS FORECAST TO STRENGTHEN TO 150KTS OVER
INDIANA. THIS JET COMBINED WITH A RIPPLE IN THE JET OVER COLORADO
HAS A SMALL AREA OF ENHANCED UPPER LEVEL DIVERGENCE WHICH PUSHES
ACROSS THE FORECAST AREA THROUGH 18Z AND ACROSS IOWA DURING THE
AFTERNOON. UPWARD VERTICAL MOTION INCREASES ACROSS CENTRAL
NEBRASKA THROUGH 12Z AND THE FORECAST AREA THIS MORNING. FAVORABLE
MID LEVEL WARM ADVECTION AND THETA-E ADVECTION INCREASE AS WELL.
THE LIFT TODAY HAS VERY FAVORABLE TEMPERATURES AS GOOD SATURATION TO
WORK WITH...SO SHOULD BE EFFICIENT WITH THE SNOW PRODUCTION AND
VISIBILITIES DROPPING DOWN TO LESS THAN A MILE. THE 00Z RUNS OF
THE NAM/GFS HAVE 2 TO 4 INCHES OF SNOW AT OMAHA USING THE COBB
METHOD AND MOST MODELS NOW HAVE BETWEEN 1 AND 4 INCHES ACROSS
PARTS OF THE CWA. THE LOW LEVEL JET IS STRONGER ACROSS
KANSAS/MISSOURI/OKLAHOMA AND THERE ARE MORE RETURNS IN KANSAS THAN
THE MODELS HAVE. THE 06Z NAM IS ABOUT 1 COUNTY FARTHER SOUTH WITH
THE HIGHER SNOW AMOUNTS...HOWEVER THE LATEST HRRR EXP HAS THE
HIGHER SNOW TRACK SLIGHTLY NORTH. SHORT MET WATCH WILL HAVE THE
BEST HANDLE ON WHERE THE HEAVIER AMOUNTS WILL FALL. OUR CURRENT
FORECAST HAS HIGHEST AMOUNTS RIGHT THROUGH EAST CENTRAL NEBRASKA
INTO WESTERN IOWA. WITH THE SNOW COMING IN DURING THE EARLY/MID
MORNING COMMUTE AND LASTING THROUGH LUNCH. AMOUNTS OF 1 TO 4
INCHES ARE EXPECTED SO DECIDED TO ISSUE A WINTER WEATHER
ADVISORY. HOLIDAY TRAVEL IS ALSO ONGOING...ALTHOUGH SOME OF THE
TRAVEL SHOULD ACTUALLY BE LIGHTER WITH SCHOOLS ON BREAK AND PEOPLE
ON HOLIDAY. THE SNOW WILL END FROM WEST TO EAST...AND SHOULD BE
EAST OF THE AREA BY MID AFTERNOON. HIGHS TODAY SHOULD MOSTLY BE IN
THE LOWER TO MID 30S...HOWEVER WARMER HIGHS AROUND 40 OR THE LOWER
40S COULD BE REACHED NEAR THE KANSAS BORDER. THE WINDS SHOULD NOT
BE AN ISSUE...MOSTLY UNDER 10 MPH.
THERE IS A BREAK FOR TONIGHT AND ALREADY ON CHRISTMAS DAY...THERE IS
SOME WEAK ENERGY PUSHING INTO THE PLAINS AHEAD OF TROUGH OVER THE
ROCKIES/SIERRAS. CLOUDS AND SOME SNOW/MIX CHANCES...ESPECIALLY IN
PARTS OF NORTHEAST NEBRASKA AND AREAS FARTHER WEST. CHRISTMAS
NIGHT...THE BRUNT OF THE SNOW IS ACROSS SOUTH DAKOTA AND
MINNESOTA...AND CLIPS PARTS OF NORTHEAST NEBRASKA AND NORTHWEST
IOWA WITH ACCUMULATING SNOW. SPOTTY RAIN/MIX WILL BE POSSIBLE
ACROSS PARTS OF THE REST OF THE CWA. SATURDAY...THE COLD AIR MOVES
FARTHER SOUTH AND WILL CONTINUE TO MENTION SNOW/MIX/RAIN...HOWEVER
ANY ACCUMULATIONS APPEAR SLIGHT...EXPECT NORTHEAST NEBRASKA COULD
SEE MORE ACCUMULATIONS. SATURDAY NIGHT...THE EC IS DRY...HOWEVER
THE NAM/SREF/GEM STILL LINGER SOME LIGHT SNOW IN THE EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
THE GFS/EC START OUT THE EXTENDED IN GOOD AGREEMENT WITH CLOSED
H5 LOW PRESSURE OVER SOUTHWEST TX INTO MEXICO...EXTENDING THE
TROUGH NORTHWARD ACROSS PARTS OF NEBRASKA INTO THE GREAT LAKES.
HOWEVER...BY MONDAY THERE ARE HUGE DIFFERENCES...THE EC IS FARTHER
NORTH WITH THE TRACK OF THE H5 LOW INTO NORTHERN TEXAS WHILE THE
GFS IS SOUTH. WILL TREND WITH THE EC AND MAINTAIN POPS MONDAY AND
MONDAY NIGHT. SHOULD THE EC WIN OUT...COULD BE SIGNIFICANT SNOW
ACCUMULATIONS FOR PARTS OF THE FORECAST AREA...WHILE THE GFS
MISSES US. SOUTHWEST IOWA COULD SEE A MIX IF THIS TRACK HOLDS...
OTHERWISE...WE ARE MAINLY ON THE COLD SIDE OF THE STORM SYSTEM. BY
WEDNESDAY...THE BULK OF THE STORM SYSTEM IS TO OUR NORTH AND EAST.
COULD BE SOME WRAP-AROUND...THEN WE ARE DRY WEDNESDAY NIGHT AND
THURSDAY. LOOK FOR AT OR BELOW NORMAL TEMPERATURES SUNDAY THROUGH
THURSDAY.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 520 AM CST THU DEC 24 2015
SNOW WILL AFFECT THE TAF SITES THIS MORNING...WITH LOWEST CIGS AND
VSBYS EXPECTED AT KLNK AND KOMA. VSBYS MAY DROP TO UNDER 1 MILE...
FROM MID MORNING THROUGH MID DAY. CONDITIONS SHOULD IMPROVE MID
TO LATE AFTERNOON WITH MAINLY VFR CONDITIONS THEN BY THIS EVENING.
NAM MODEL HOLDS ONTO LOW CLOUDS A BIT LONGER...SO WILL HAVE TO
MONITOR TRENDS FOR LATER TAFS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR NEZ034-
045-052-053-067.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NEZ044-050-051-
065-066-078.
IA...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR IAZ043-
055-056-069-079.
&&
$$
UPDATE...DERGAN
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
851 AM CST THU DEC 24 2015
.UPDATE...
ISSUED AT 844 AM CST THU DEC 24 2015
SNOW CONTINUES OVER MUCH OF EASTERN NEBRASKA AND SOUTHWEST IOWA.
RADAR TRENDS OVER THE LAST HOUR OR SO SHOW MOST INTENSE SNOWFALL
OCCURRING FROM THE NORTH SIDE OF LINCOLN TO OMAHA AND COUNCIL
BLUFFS. MULTIPLE REPORTS OF 2 INCH ACCUMULATIONS FROM LINCOLN TO
OMAHA AS OF 830 AM. ANOTHER 2 INCHES ARE LIKELY IN THE HEAVIEST
BANDS THROUGH 11 AM OR SO. ALREADY SEEING SNOW ENDING IN SOUTH
CENTRAL NEBRASKA JUST WEST OF FAIRBURY AND YORK...AND TOTAL
SNOWFALL OF 3.5 INCHES WERE RECEIVED IN PARTS OF THOSE AREAS. SO
WOULD EXPECT TOTALS HERE TO REACH THAT 3 TO 4 INCH RANGE RATHER
EASILY...WITH LESSER AMOUNTS CLOSER TO AN INCH BY NORFOLK ON
FRINGE OF SNOW BAND...AND IN FAR SOUTHEAST NEBRASKA AND FAR
SOUTHWEST IOWA WHERE TEMPERATURES ARE AT OR ABOVE FREEZING AND
SOME RAIN/SLEET IS MIXING IN.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
...SNOW THROUGH EARLY AFTERNOON...WARMER FOR CHRISTMAS DAY WITH
SNOW FOR NORTHEAST NEBRASKA...
FORECAST CONCERNS FOR TODAY WILL BE FAST-MOVING STORM SYSTEM AND HOW
MUCH SNOW WILL FALL...SPOTTY PRECIPITATION POTENTIAL
CHRISTMAS...THEN EXPANDING PRECIPITATION AREA CHRISTMAS NIGHT INTO
SATURDAY NIGHT WITH ACCUMULATING SNOW/MIX FOR PARTS OF NORTHEAST
NEBRASKA.
THE 00Z OAX SOUNDING HAD DRIED OUT WITH 0.25 PWAT. A LOOK TO THE
WEST AND KLBF HAD PWAT OF 0.20...HOWEVER WAS SATURATED AT 6KFT WITH
TEMPERATURES IN THE DENDRITIC LAYER OF -11 TO -15DEG C.
ON THE H3 CHART...THE 100-140KT STRETCHED FROM NORTHERN CALIFORNIA
ACROSS THE SOUTHERN PLAINS...TURNING NORTH INTO ILLINOIS AND WI.
BROAD TROF WITH EMBEDDED SHORTWAVES STILL DOMINATED THE MID
TROPOSPHERIC FLOW. THE APPROACHING SHORTWAVE AT 06Z EXTENDED FROM
WYOMING ACROSS COLORADO INTO NEW MEXICO. 40M HEIGHT FALLS WERE
ASSOCIATED WITH THIS FEATURE. LIGHTNING STRIKES WERE NOTED WITH
FROM SOUTHEAST UTAH THROUGH COLORADO INTO NEW MEXICO DURING THE
EVENING AND IN NORTHWEST KANSAS AROUND 06Z. AT H7 COLD
TEMPERATURES WERE OBSERVED...HOWEVER THE H85 THERMAL TROUGH WAS
OVER OAX AND TOP...WITH WARMER H85 TEMPERATURES OVER WESTERN
KANSAS. H85 MOISTURE WAS RETURNING TO THE ROCKIES ACROSS MEXICO
INTO ARIZONA/NEW MEXICO AND SOUTHWEST COLORADO.
AT 05Z THERE WAS 2-STAR SNOW IN NORTHEAST COLORADO AND 3-STAR SNOW
IN NORTHWEST KANSAS WITH SOME LIGHTNING. AT 0930Z THE WSR-88D
RADAR MOSAIC SHOWED SNOW SPREADING NORTHEAST WITH RETURNS AS CLOSE
AT ALBION BY 10Z AND THE STRONGER RETURNS OVER NORTH CENTRAL
KANSAS AND SOUTH CENTRAL NEBRASKA.
THROUGH 12Z...THE H3 JET IS FORECAST TO STRENGTHEN TO 150KTS OVER
INDIANA. THIS JET COMBINED WITH A RIPPLE IN THE JET OVER COLORADO
HAS A SMALL AREA OF ENHANCED UPPER LEVEL DIVERGENCE WHICH PUSHES
ACROSS THE FORECAST AREA THROUGH 18Z AND ACROSS IOWA DURING THE
AFTERNOON. UPWARD VERTICAL MOTION INCREASES ACROSS CENTRAL
NEBRASKA THROUGH 12Z AND THE FORECAST AREA THIS MORNING. FAVORABLE
MID LEVEL WARM ADVECTION AND THETA-E ADVECTION INCREASE AS WELL.
THE LIFT TODAY HAS VERY FAVORABLE TEMPERATURES AS GOOD SATURATION TO
WORK WITH...SO SHOULD BE EFFICIENT WITH THE SNOW PRODUCTION AND
VISIBILITIES DROPPING DOWN TO LESS THAN A MILE. THE 00Z RUNS OF
THE NAM/GFS HAVE 2 TO 4 INCHES OF SNOW AT OMAHA USING THE COBB
METHOD AND MOST MODELS NOW HAVE BETWEEN 1 AND 4 INCHES ACROSS
PARTS OF THE CWA. THE LOW LEVEL JET IS STRONGER ACROSS
KANSAS/MISSOURI/OKLAHOMA AND THERE ARE MORE RETURNS IN KANSAS THAN
THE MODELS HAVE. THE 06Z NAM IS ABOUT 1 COUNTY FARTHER SOUTH WITH
THE HIGHER SNOW AMOUNTS...HOWEVER THE LATEST HRRR EXP HAS THE
HIGHER SNOW TRACK SLIGHTLY NORTH. SHORT MET WATCH WILL HAVE THE
BEST HANDLE ON WHERE THE HEAVIER AMOUNTS WILL FALL. OUR CURRENT
FORECAST HAS HIGHEST AMOUNTS RIGHT THROUGH EAST CENTRAL NEBRASKA
INTO WESTERN IOWA. WITH THE SNOW COMING IN DURING THE EARLY/MID
MORNING COMMUTE AND LASTING THROUGH LUNCH. AMOUNTS OF 1 TO 4
INCHES ARE EXPECTED SO DECIDED TO ISSUE A WINTER WEATHER
ADVISORY. HOLIDAY TRAVEL IS ALSO ONGOING...ALTHOUGH SOME OF THE
TRAVEL SHOULD ACTUALLY BE LIGHTER WITH SCHOOLS ON BREAK AND PEOPLE
ON HOLIDAY. THE SNOW WILL END FROM WEST TO EAST...AND SHOULD BE
EAST OF THE AREA BY MID AFTERNOON. HIGHS TODAY SHOULD MOSTLY BE IN
THE LOWER TO MID 30S...HOWEVER WARMER HIGHS AROUND 40 OR THE LOWER
40S COULD BE REACHED NEAR THE KANSAS BORDER. THE WINDS SHOULD NOT
BE AN ISSUE...MOSTLY UNDER 10 MPH.
THERE IS A BREAK FOR TONIGHT AND ALREADY ON CHRISTMAS DAY...THERE IS
SOME WEAK ENERGY PUSHING INTO THE PLAINS AHEAD OF TROUGH OVER THE
ROCKIES/SIERRAS. CLOUDS AND SOME SNOW/MIX CHANCES...ESPECIALLY IN
PARTS OF NORTHEAST NEBRASKA AND AREAS FARTHER WEST. CHRISTMAS
NIGHT...THE BRUNT OF THE SNOW IS ACROSS SOUTH DAKOTA AND
MINNESOTA...AND CLIPS PARTS OF NORTHEAST NEBRASKA AND NORTHWEST
IOWA WITH ACCUMULATING SNOW. SPOTTY RAIN/MIX WILL BE POSSIBLE
ACROSS PARTS OF THE REST OF THE CWA. SATURDAY...THE COLD AIR MOVES
FARTHER SOUTH AND WILL CONTINUE TO MENTION SNOW/MIX/RAIN...HOWEVER
ANY ACCUMULATIONS APPEAR SLIGHT...EXPECT NORTHEAST NEBRASKA COULD
SEE MORE ACCUMULATIONS. SATURDAY NIGHT...THE EC IS DRY...HOWEVER
THE NAM/SREF/GEM STILL LINGER SOME LIGHT SNOW IN THE EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
THE GFS/EC START OUT THE EXTENDED IN GOOD AGREEMENT WITH CLOSED
H5 LOW PRESSURE OVER SOUTHWEST TX INTO MEXICO...EXTENDING THE
TROUGH NORTHWARD ACROSS PARTS OF NEBRASKA INTO THE GREAT LAKES.
HOWEVER...BY MONDAY THERE ARE HUGE DIFFERENCES...THE EC IS FARTHER
NORTH WITH THE TRACK OF THE H5 LOW INTO NORTHERN TEXAS WHILE THE
GFS IS SOUTH. WILL TREND WITH THE EC AND MAINTAIN POPS MONDAY AND
MONDAY NIGHT. SHOULD THE EC WIN OUT...COULD BE SIGNIFICANT SNOW
ACCUMULATIONS FOR PARTS OF THE FORECAST AREA...WHILE THE GFS
MISSES US. SOUTHWEST IOWA COULD SEE A MIX IF THIS TRACK HOLDS...
OTHERWISE...WE ARE MAINLY ON THE COLD SIDE OF THE STORM SYSTEM. BY
WEDNESDAY...THE BULK OF THE STORM SYSTEM IS TO OUR NORTH AND EAST.
COULD BE SOME WRAP-AROUND...THEN WE ARE DRY WEDNESDAY NIGHT AND
THURSDAY. LOOK FOR AT OR BELOW NORMAL TEMPERATURES SUNDAY THROUGH
THURSDAY.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 520 AM CST THU DEC 24 2015
SNOW WILL AFFECT THE TAF SITES THIS MORNING...WITH LOWEST CIGS AND
VSBYS EXPECTED AT KLNK AND KOMA. VSBYS MAY DROP TO UNDER 1 MILE...
FROM MID MORNING THROUGH MID DAY. CONDITIONS SHOULD IMPROVE MID
TO LATE AFTERNOON WITH MAINLY VFR CONDITIONS THEN BY THIS EVENING.
NAM MODEL HOLDS ONTO LOW CLOUDS A BIT LONGER...SO WILL HAVE TO
MONITOR TRENDS FOR LATER TAFS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR NEZ034-
045-052-053-067.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NEZ044-050-051-
065-066-078.
IA...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR IAZ043-
055-056-069-079.
&&
$$
UPDATE...DERGAN
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
520 AM CST THU DEC 24 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
...SNOW THROUGH EARLY AFTERNOON...WARMER FOR CHRISTMAS DAY WITH
SNOW FOR NORTHEAST NEBRASKA...
FORECAST CONCERNS FOR TODAY WILL BE FAST-MOVING STORM SYSTEM AND HOW
MUCH SNOW WILL FALL...SPOTTY PRECIPITATION POTENTIAL
CHRISTMAS...THEN EXPANDING PRECIPITATION AREA CHRISTMAS NIGHT INTO
SATURDAY NIGHT WITH ACCUMULATING SNOW/MIX FOR PARTS OF NORTHEAST
NEBRASKA.
THE 00Z OAX SOUNDING HAD DRIED OUT WITH 0.25 PWAT. A LOOK TO THE
WEST AND KLBF HAD PWAT OF 0.20...HOWEVER WAS SATURATED AT 6KFT WITH
TEMPERATURES IN THE DENDRITIC LAYER OF -11 TO -15DEG C.
ON THE H3 CHART...THE 100-140KT STRETCHED FROM NORTHERN CALIFORNIA
ACROSS THE SOUTHERN PLAINS...TURNING NORTH INTO ILLINOIS AND WI.
BROAD TROF WITH EMBEDDED SHORTWAVES STILL DOMINATED THE MID
TROPOSPHERIC FLOW. THE APPROACHING SHORTWAVE AT 06Z EXTENDED FROM
WYOMING ACROSS COLORADO INTO NEW MEXICO. 40M HEIGHT FALLS WERE
ASSOCIATED WITH THIS FEATURE. LIGHTNING STRIKES WERE NOTED WITH
FROM SOUTHEAST UTAH THROUGH COLORADO INTO NEW MEXICO DURING THE
EVENING AND IN NORTHWEST KANSAS AROUND 06Z. AT H7 COLD
TEMPERATURES WERE OBSERVED...HOWEVER THE H85 THERMAL TROUGH WAS
OVER OAX AND TOP...WITH WARMER H85 TEMPERATURES OVER WESTERN
KANSAS. H85 MOISTURE WAS RETURNING TO THE ROCKIES ACROSS MEXICO
INTO ARIZONA/NEW MEXICO AND SOUTHWEST COLORADO.
AT 05Z THERE WAS 2-STAR SNOW IN NORTHEAST COLORADO AND 3-STAR SNOW
IN NORTHWEST KANSAS WITH SOME LIGHTNING. AT 0930Z THE WSR-88D
RADAR MOSAIC SHOWED SNOW SPREADING NORTHEAST WITH RETURNS AS CLOSE
AT ALBION BY 10Z AND THE STRONGER RETURNS OVER NORTH CENTRAL
KANSAS AND SOUTH CENTRAL NEBRASKA.
THROUGH 12Z...THE H3 JET IS FORECAST TO STRENGTHEN TO 150KTS OVER
INDIANA. THIS JET COMBINED WITH A RIPPLE IN THE JET OVER COLORADO
HAS A SMALL AREA OF ENHANCED UPPER LEVEL DIVERGENCE WHICH PUSHES
ACROSS THE FORECAST AREA THROUGH 18Z AND ACROSS IOWA DURING THE
AFTERNOON. UPWARD VERTICAL MOTION INCREASES ACROSS CENTRAL
NEBRASKA THROUGH 12Z AND THE FORECAST AREA THIS MORNING. FAVORABLE
MID LEVEL WARM ADVECTION AND THETA-E ADVECTION INCREASE AS WELL.
THE LIFT TODAY HAS VERY FAVORABLE TEMPERATURES AS GOOD SATURATION TO
WORK WITH...SO SHOULD BE EFFICIENT WITH THE SNOW PRODUCTION AND
VISIBILITIES DROPPING DOWN TO LESS THAN A MILE. THE 00Z RUNS OF
THE NAM/GFS HAVE 2 TO 4 INCHES OF SNOW AT OMAHA USING THE COBB
METHOD AND MOST MODELS NOW HAVE BETWEEN 1 AND 4 INCHES ACROSS
PARTS OF THE CWA. THE LOW LEVEL JET IS STRONGER ACROSS
KANSAS/MISSOURI/OKLAHOMA AND THERE ARE MORE RETURNS IN KANSAS THAN
THE MODELS HAVE. THE 06Z NAM IS ABOUT 1 COUNTY FARTHER SOUTH WITH
THE HIGHER SNOW AMOUNTS...HOWEVER THE LATEST HRRR EXP HAS THE
HIGHER SNOW TRACK SLIGHTLY NORTH. SHORT MET WATCH WILL HAVE THE
BEST HANDLE ON WHERE THE HEAVIER AMOUNTS WILL FALL. OUR CURRENT
FORECAST HAS HIGHEST AMOUNTS RIGHT THROUGH EAST CENTRAL NEBRASKA
INTO WESTERN IOWA. WITH THE SNOW COMING IN DURING THE EARLY/MID
MORNING COMMUTE AND LASTING THROUGH LUNCH. AMOUNTS OF 1 TO 4
INCHES ARE EXPECTED SO DECIDED TO ISSUE A WINTER WEATHER
ADVISORY. HOLIDAY TRAVEL IS ALSO ONGOING...ALTHOUGH SOME OF THE
TRAVEL SHOULD ACTUALLY BE LIGHTER WITH SCHOOLS ON BREAK AND PEOPLE
ON HOLIDAY. THE SNOW WILL END FROM WEST TO EAST...AND SHOULD BE
EAST OF THE AREA BY MID AFTERNOON. HIGHS TODAY SHOULD MOSTLY BE IN
THE LOWER TO MID 30S...HOWEVER WARMER HIGHS AROUND 40 OR THE LOWER
40S COULD BE REACHED NEAR THE KANSAS BORDER. THE WINDS SHOULD NOT
BE AN ISSUE...MOSTLY UNDER 10 MPH.
THERE IS A BREAK FOR TONIGHT AND ALREADY ON CHRISTMAS DAY...THERE IS
SOME WEAK ENERGY PUSHING INTO THE PLAINS AHEAD OF TROUGH OVER THE
ROCKIES/SIERRAS. CLOUDS AND SOME SNOW/MIX CHANCES...ESPECIALLY IN
PARTS OF NORTHEAST NEBRASKA AND AREAS FARTHER WEST. CHRISTMAS
NIGHT...THE BRUNT OF THE SNOW IS ACROSS SOUTH DAKOTA AND
MINNESOTA...AND CLIPS PARTS OF NORTHEAST NEBRASKA AND NORTHWEST
IOWA WITH ACCUMULATING SNOW. SPOTTY RAIN/MIX WILL BE POSSIBLE
ACROSS PARTS OF THE REST OF THE CWA. SATURDAY...THE COLD AIR MOVES
FARTHER SOUTH AND WILL CONTINUE TO MENTION SNOW/MIX/RAIN...HOWEVER
ANY ACCUMULATIONS APPEAR SLIGHT...EXPECT NORTHEAST NEBRASKA COULD
SEE MORE ACCUMULATIONS. SATURDAY NIGHT...THE EC IS DRY...HOWEVER
THE NAM/SREF/GEM STILL LINGER SOME LIGHT SNOW IN THE EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
THE GFS/EC START OUT THE EXTENDED IN GOOD AGREEMENT WITH CLOSED
H5 LOW PRESSURE OVER SOUTHWEST TX INTO MEXICO...EXTENDING THE
TROUGH NORTHWARD ACROSS PARTS OF NEBRASKA INTO THE GREAT LAKES.
HOWEVER...BY MONDAY THERE ARE HUGE DIFFERENCES...THE EC IS FARTHER
NORTH WITH THE TRACK OF THE H5 LOW INTO NORTHERN TEXAS WHILE THE
GFS IS SOUTH. WILL TREND WITH THE EC AND MAINTAIN POPS MONDAY AND
MONDAY NIGHT. SHOULD THE EC WIN OUT...COULD BE SIGNIFICANT SNOW
ACCUMULATIONS FOR PARTS OF THE FORECAST AREA...WHILE THE GFS
MISSES US. SOUTHWEST IOWA COULD SEE A MIX IF THIS TRACK HOLDS...
OTHERWISE...WE ARE MAINLY ON THE COLD SIDE OF THE STORM SYSTEM. BY
WEDNESDAY...THE BULK OF THE STORM SYSTEM IS TO OUR NORTH AND EAST.
COULD BE SOME WRAP-AROUND...THEN WE ARE DRY WEDNESDAY NIGHT AND
THURSDAY. LOOK FOR AT OR BELOW NORMAL TEMPERATURES SUNDAY THROUGH
THURSDAY.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 520 AM CST THU DEC 24 2015
SNOW WILL AFFECT THE TAF SITES THIS MORNING...WITH LOWEST CIGS AND
VSBYS EXPECTED AT KLNK AND KOMA. VSBYS MAY DROP TO UNDER 1 MILE...
FROM MID MORNING THROUGH MID DAY. CONDITIONS SHOULD IMPROVE MID
TO LATE AFTERNOON WITH MAINLY VFR CONDITIONS THEN BY THIS EVENING.
NAM MODEL HOLDS ONTO LOW CLOUDS A BIT LONGER...SO WILL HAVE TO
MONITOR TRENDS FOR LATER TAFS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR NEZ034-
045-052-053-067.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NEZ044-050-051-
065-066-078.
IA...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR IAZ043-
055-056-069-079.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
432 AM CST THU DEC 24 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
...SNOW THROUGH EARLY AFTERNOON...WARMER FOR CHRISTMAS DAY WITH
SNOW FOR NORTHEAST NEBRASKA...
FORECAST CONCERNS FOR TODAY WILL BE FAST-MOVING STORM SYSTEM AND HOW
MUCH SNOW WILL FALL...SPOTTY PRECIPITATION POTENTIAL
CHRISTMAS...THEN EXPANDING PRECIPITATION AREA CHRISTMAS NIGHT INTO
SATURDAY NIGHT WITH ACCUMULATING SNOW/MIX FOR PARTS OF NORTHEAST
NEBRASKA.
THE 00Z OAX SOUNDING HAD DRIED OUT WITH 0.25 PWAT. A LOOK TO THE
WEST AND KLBF HAD PWAT OF 0.20...HOWEVER WAS SATURATED AT 6KFT WITH
TEMPERATURES IN THE DENDRITIC LAYER OF -11 TO -15DEG C.
ON THE H3 CHART...THE 100-140KT STRETCHED FROM NORTHERN CALIFORNIA
ACROSS THE SOUTHERN PLAINS...TURNING NORTH INTO ILLINOIS AND WI.
BROAD TROF WITH EMBEDDED SHORTWAVES STILL DOMINATED THE MID
TROPOSPHERIC FLOW. THE APPROACHING SHORTWAVE AT 06Z EXTENDED FROM
WYOMING ACROSS COLORADO INTO NEW MEXICO. 40M HEIGHT FALLS WERE
ASSOCIATED WITH THIS FEATURE. LIGHTNING STRIKES WERE NOTED WITH
FROM SOUTHEAST UTAH THROUGH COLORADO INTO NEW MEXICO DURING THE
EVENING AND IN NORTHWEST KANSAS AROUND 06Z. AT H7 COLD
TEMPERATURES WERE OBSERVED...HOWEVER THE H85 THERMAL TROUGH WAS
OVER OAX AND TOP...WITH WARMER H85 TEMPERATURES OVER WESTERN
KANSAS. H85 MOISTURE WAS RETURNING TO THE ROCKIES ACROSS MEXICO
INTO ARIZONA/NEW MEXICO AND SOUTHWEST COLORADO.
AT 05Z THERE WAS 2-STAR SNOW IN NORTHEAST COLORADO AND 3-STAR SNOW
IN NORTHWEST KANSAS WITH SOME LIGHTNING. AT 0930Z THE WSR-88D
RADAR MOSAIC SHOWED SNOW SPREADING NORTHEAST WITH RETURNS AS CLOSE
AT ALBION BY 10Z AND THE STRONGER RETURNS OVER NORTH CENTRAL
KANSAS AND SOUTH CENTRAL NEBRASKA.
THROUGH 12Z...THE H3 JET IS FORECAST TO STRENGTHEN TO 150KTS OVER
INDIANA. THIS JET COMBINED WITH A RIPPLE IN THE JET OVER COLORADO
HAS A SMALL AREA OF ENHANCED UPPER LEVEL DIVERGENCE WHICH PUSHES
ACROSS THE FORECAST AREA THROUGH 18Z AND ACROSS IOWA DURING THE
AFTERNOON. UPWARD VERTICAL MOTION INCREASES ACROSS CENTRAL
NEBRASKA THROUGH 12Z AND THE FORECAST AREA THIS MORNING. FAVORABLE
MID LEVEL WARM ADVECTION AND THETA-E ADVECTION INCREASE AS WELL.
THE LIFT TODAY HAS VERY FAVORABLE TEMPERATURES AS GOOD SATURATION TO
WORK WITH...SO SHOULD BE EFFICIENT WITH THE SNOW PRODUCTION AND
VISIBILITIES DROPPING DOWN TO LESS THAN A MILE. THE 00Z RUNS OF
THE NAM/GFS HAVE 2 TO 4 INCHES OF SNOW AT OMAHA USING THE COBB
METHOD AND MOST MODELS NOW HAVE BETWEEN 1 AND 4 INCHES ACROSS
PARTS OF THE CWA. THE LOW LEVEL JET IS STRONGER ACROSS
KANSAS/MISSOURI/OKLAHOMA AND THERE ARE MORE RETURNS IN KANSAS THAN
THE MODELS HAVE. THE 06Z NAM IS ABOUT 1 COUNTY FARTHER SOUTH WITH
THE HIGHER SNOW AMOUNTS...HOWEVER THE LATEST HRRR EXP HAS THE
HIGHER SNOW TRACK SLIGHTLY NORTH. SHORT MET WATCH WILL HAVE THE
BEST HANDLE ON WHERE THE HEAVIER AMOUNTS WILL FALL. OUR CURRENT
FORECAST HAS HIGHEST AMOUNTS RIGHT THROUGH EAST CENTRAL NEBRASKA
INTO WESTERN IOWA. WITH THE SNOW COMING IN DURING THE EARLY/MID
MORNING COMMUTE AND LASTING THROUGH LUNCH. AMOUNTS OF 1 TO 4
INCHES ARE EXPECTED SO DECIDED TO ISSUE A WINTER WEATHER
ADVISORY. HOLIDAY TRAVEL IS ALSO ONGOING...ALTHOUGH SOME OF THE
TRAVEL SHOULD ACTUALLY BE LIGHTER WITH SCHOOLS ON BREAK AND PEOPLE
ON HOLIDAY. THE SNOW WILL END FROM WEST TO EAST...AND SHOULD BE
EAST OF THE AREA BY MID AFTERNOON. HIGHS TODAY SHOULD MOSTLY BE IN
THE LOWER TO MID 30S...HOWEVER WARMER HIGHS AROUND 40 OR THE LOWER
40S COULD BE REACHED NEAR THE KANSAS BORDER. THE WINDS SHOULD NOT
BE AN ISSUE...MOSTLY UNDER 10 MPH.
THERE IS A BREAK FOR TONIGHT AND ALREADY ON CHRISTMAS DAY...THERE IS
SOME WEAK ENERGY PUSHING INTO THE PLAINS AHEAD OF TROUGH OVER THE
ROCKIES/SIERRAS. CLOUDS AND SOME SNOW/MIX CHANCES...ESPECIALLY IN
PARTS OF NORTHEAST NEBRASKA AND AREAS FARTHER WEST. CHRISTMAS
NIGHT...THE BRUNT OF THE SNOW IS ACROSS SOUTH DAKOTA AND
MINNESOTA...AND CLIPS PARTS OF NORTHEAST NEBRASKA AND NORTHWEST
IOWA WITH ACCUMULATING SNOW. SPOTTY RAIN/MIX WILL BE POSSIBLE
ACROSS PARTS OF THE REST OF THE CWA. SATURDAY...THE COLD AIR MOVES
FARTHER SOUTH AND WILL CONTINUE TO MENTION SNOW/MIX/RAIN...HOWEVER
ANY ACCUMULATIONS APPEAR SLIGHT...EXPECT NORTHEAST NEBRASKA COULD
SEE MORE ACCUMULATIONS. SATURDAY NIGHT...THE EC IS DRY...HOWEVER
THE NAM/SREF/GEM STILL LINGER SOME LIGHT SNOW IN THE EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
THE GFS/EC START OUT THE EXTENDED IN GOOD AGREEMENT WITH CLOSED
H5 LOW PRESSURE OVER SOUTHWEST TX INTO MEXICO...EXTENDING THE
TROUGH NORTHWARD ACROSS PARTS OF NEBRASKA INTO THE GREAT LAKES.
HOWEVER...BY MONDAY THERE ARE HUGE DIFFERENCES...THE EC IS FARTHER
NORTH WITH THE TRACK OF THE H5 LOW INTO NORTHERN TEXAS WHILE THE
GFS IS SOUTH. WILL TREND WITH THE EC AND MAINTAIN POPS MONDAY AND
MONDAY NIGHT. SHOULD THE EC WIN OUT...COULD BE SIGNIFICANT SNOW
ACCUMULATIONS FOR PARTS OF THE FORECAST AREA...WHILE THE GFS
MISSES US. SOUTHWEST IOWA COULD SEE A MIX IF THIS TRACK HOLDS...
OTHERWISE...WE ARE MAINLY ON THE COLD SIDE OF THE STORM SYSTEM. BY
WEDNESDAY...THE BULK OF THE STORM SYSTEM IS TO OUR NORTH AND EAST.
COULD BE SOME WRAP-AROUND...THEN WE ARE DRY WEDNESDAY NIGHT AND
THURSDAY. LOOK FOR AT OR BELOW NORMAL TEMPERATURES SUNDAY THROUGH
THURSDAY.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1120 PM CST WED DEC 23 2015
FORECAST REMAINS ON TRACK WITH MINOR TWEAKS NEEDED. VFR CONDITIONS...
BECOMING MVFR AND EVENTUALLY IFR AS SNOW MOVES INTO ALL 3 TAF
SITES BY 11-13Z. VISIBILITY COULD DROP AS LOW AS 1 MILE AT TIMES
KLNK/KOMA MID MORNING THROUGH EARLY AFTERNOON...THEN SNOW ENDING
BY 19-21Z. STILL LOOKING AT LIGHT ACCUMULATIONS OF 1 TO 3 INCHES
ACROSS THE AREA...BUT SOME OF THAT WILL BE MELTING ON WARM
GROUND...AS DAYTIME TEMPERATURES CLIMB INTO THE MID 30S. WINDS
REMAIN LIGHT GENERALLY LESS THAN 7 KNOTS THROUGH THE PERIOD.
TRANSITIONING BACK TO VFR BY 22-03Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 2 PM CST THIS
AFTERNOON FOR NEZ034-045-052-053-067.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NEZ044-050-051-
065-066-078.
IA...WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 2 PM CST THIS
AFTERNOON FOR IAZ043-055-056-069-079.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
112 AM EST THU DEC 24 2015
.SYNOPSIS...
UNSEASONABLY WARM, AND SHOWERY WEATHER, WILL PERSIST INTO
THURSDAY. IN FACT, RECORD HIGH TEMPERATURES IN THE MID AND UPPER
60S ARE EXPECTED CHRISTMAS EVE DAY. CHRISTMAS DAY LOOKS DRY, AND
STILL FAIRLY MILD, WITH HIGHS MOSTLY IN THE FIFTIES. RAIN IS
LIKELY BY LATER SATURDAY, AS A WARM FRONT APPROACHES FROM THE
SOUTH.
&&
.NEAR TERM /THROUGH TODAY/...
945 PM UPDATE...
SPED UP TIMING OF FIRST BATCH OF RAIN EVEN FASTER. LOWERED POPS IN
THE WEST TO NOTHING. WILL BE WAITING FOR THE CONVECTION IN OHIO.
MODEL DIFFERENCES ON TIMING AND COVERAGE. FOLLOWING THE HRRR SOME
AND BRINGING IN SHOWERS INTO STEUBEN AROUND 9Z. CONFIDENCE NOT
HIGH ENOUGH TO INCLUDE THUNDER BUT MODELS HINTING AT SOME
REMAINING. TEMPERATURES ARE SLOWLY RISING.
7 PM UPDATE...
RAIN ALREADY PULLING OUT OF WRN ZONES AND DROPPED POPS AND QPF.
REST OF RAIN WILL PULL OUT THIS EVENING. AFTER THAT WILL JUST GET
REMNANTS FROM THE CONVECTION NOW IN THE OHIO VALLEY LATE TONIGHT.
TEMPS ARE TRICKY WITH MAX AND MIN TEMPS ALMOST THE SAME AS
TEMPERATURES RISE TONIGHT. SOME CURRENT TEMPS ABOVE THE AFTN MAX
TEMP GRID. ADJUSTED MAX MIN AND HOURLY TEMPS. CLOUDY SKIES WILL
CONTINUE OVERNIGHT WITH THE DEEP MOIST SOUTHERLY FLOW.
230 PM UPDATE...
SHOWERS ARE OVERSPREADING THE REGION THIS AFTERNOON, RIGHT ON
SCHEDULE, AND THEY SHOULD CONTINUE THROUGH EARLY EVENING. MOST OF
THE FORCED LIFT, WITH THE ASSOCIATED SHORT-WAVE, SHOULD BE EAST
OF OUR FORECAST AREA BY MIDNIGHT. THUS, WE STILL ANTICIPATE A
LULL IN PRECIPITATION OVERNIGHT.
MOST OF OUR HIGH-RESOLUTION MODEL GUIDANCE BRINGS A WEAKENING
LINE OF SHOWERS INTO WESTERN NY/PA DURING THE PRE-DAWN HOURS. THIS
IS LIKELY THE REMNANTS OF THE CONVECTIVE LINE IMPACTING SRN
IL/IN/WRN KY THIS AFTERNOON. AS JUST STATED, THIS LINE OF SHOWERS
SHOULD BE IN A WEAKENING STATE AS IT PROGRESSES EASTWARD, AND AS
SUCH, ITS SURVIVAL INTO OUR FORECAST AREA CLOSE TO DAYBREAK IS
UNCERTAIN. FOR NOW, WE`RE CALLING FOR SCATTERED SHOWERS AFTER 4-5
AM, TO COVER THIS POSSIBILITY.
AS A LOW-LEVEL JET MOVES OVERHEAD LATE TONIGHT INTO EARLY
THURSDAY, CONDITIONS SHOULD BECOME WELL MIXED, THUS MAKING
WIDESPREAD FOG DEVELOPMENT UNLIKELY. PART OF THIS STRENGTHENING
FLOW REGIME WILL ALSO BE VERY PRONOUNCED LOW-LEVEL WARM ADVECTION.
THUS, WE`VE CONTINUED TO INDICATE RISING TEMPERATURES OVERNIGHT,
AND MANY AREAS SHOULD ALREADY BE INTO THE 60S BY 5-8 AM.
A STRENGTHENING CYCLONE WILL CONTINUE TO TRACK THROUGH THE WESTERN
LAKES REGION, AND THEN INTO ONTARIO FOR CHRISTMAS EVE. AS IT DOES
SO, IT WILL SWING A COLD FRONT ACROSS CENTRAL NY/NORTHEAST PA
DURING THE LATE MORNING/EARLY AFTERNOON PERIOD. THE BEST UPPER-
LEVEL DYNAMICS WILL BE UP OVER CANADA, AND WELL REMOVED FROM OUR
REGION. THUS, WE FEEL THAT SHOWER ACTIVITY, ALONG AND AHEAD OF
THE FRONT, WILL BE SCATTERED IN NATURE FOR MOST OF THE FORECAST
AREA. GIVEN THE ANOMALOUS WARMTH, NAM/SREF GUIDANCE IN PARTICULAR
SHOWS WEAK INSTABILITY ON THURSDAY (200-400 J/KG OF ML CAPE). AS A
RESULT, WE HAVE AN ISOLATED MENTION OF THUNDER. SHOWERS SHOULD
HAVE A TENDENCY TO DIMINISH FROM WEST TO EAST DURING THE
AFTERNOON, AS THE FRONT SWEEPS THROUGH THE REGION.
AS MENTIONED EARLIER, RECORD HIGHS SHOULD EASILY BE ATTAINED
THURSDAY (CURRENT RECORDS ARE 51 AT BINGHAMTON, 58 AT SYRACUSE,
AND 62 AT SCRANTON). IN FACT, SOME OF OUR NORMALLY WARMER VALLEY
LOCALES, ESPECIALLY OVER NORTHEAST PA, COULD EVEN MAKE A RUN AT 70
DEGREES!
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
3 PM UPDATE...
LATE CHRISTMAS EVE-CHRISTMAS DAY LOOKS MAINLY DRY, AS THE
AFOREMENTIONED FRONTAL ZONE SINKS SOUTHWARD INTO THE MID-ATLANTIC
REGION. THE AIR MASS BEHIND THE FRONT IS NOT VERY COLD AT ALL, AND
THIS IN COMBINATION WITH SOME SUNSHINE ON FRIDAY, SHOULD STILL
BRING HIGHS INTO THE 50S-LOWER 60S.
SATURDAY, THIS SAME FRONTAL BOUNDARY WILL BEGIN TO HEAD BACK
NORTHWARD AGAIN AS A WARM FRONT, IN RESPONSE TO ANOTHER DEVELOPING
CYCLONE OVER THE SOUTH-CENTRAL STATES. BY LATE SATURDAY, MODEL
GUIDANCE IS IN GOOD AGREEMENT DEPICTING A VERY STRONG UPPER JET
STREAK TO OUR NORTH, WITH THE RESPONSE BEING AN INCREASED LOW-
LEVEL JET/TIGHTENED THERMAL GRADIENT OVER NY/PA, JUST NORTH OF THE
APPROACHING WARM FRONT. ANY EARLY SUNSHINE SHOULD FADE BEHIND
INCREASING CLOUDS. THE LIKELIHOOD OF RAIN SHOULD THEN OVERSPREAD
THE FORECAST AREA, FROM SOUTH TO NORTH, BY LATE SATURDAY/SATURDAY
EVENING.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
310 PM UPDATE...
THE LARGE-SCALE PATTERN SHOULD FEATURE AN ENERGETIC SOUTHWESTERLY
FLOW ALOFT EARLY IN THE PERIOD (THROUGH WEDNESDAY), WITH A
DEVELOPING BROAD TROUGH, AND MORE SEASONABLE TEMPERATURES LATER
NEXT WEEK.
AS FOR THE DAILY SENSIBLE WEATHER, MILD SHOWERY WEATHER SUNDAY,
WILL BE FOLLOWED BY A GRADUAL COOL-DOWN EARLY NEXT WEEK. THE
BIGGEST UNCERTAINTY LIES WITH THE EVOLUTION/EJECTION OF A POTENT
SOUTHERN-STREAM WAVE LATE MONDAY-TUESDAY (MODELS DIFFER
SIGNIFICANTLY ON TIMING/SURFACE LOW TRACK). IF PRECIPITATION
DEVELOPS QUICKLY ENOUGH, MIXED PHASE (SNOW/SLEET/FREEZING RAIN
MIX) WOULD BE POSSIBLE MONDAY NIGHT OR TUESDAY. IF THE MOISTURE
DOESN`T MOVE IN UNTIL MID-WEEK, TEMPERATURES SHOULD BE WARM ENOUGH
FOR RAIN BY THEN. TIME WILL TELL ON THIS ONE, WITH BETTER MODEL
AGREEMENT HOPEFULLY SEEN IN LATER RUNS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
PLENTY OF LOW LEVEL MOISTURE IS LINGERING THIS MORNING. A MIXTURE
OF LOW AND HIGH END MVFR CONDITIONS ARE PRESENT THIS MORNING
ACROSS MUCH OF THE AREA. EXPECT CONDITIONS TO IMPROVE AROUND 12Z
TO VFR. ANOTHER ROUND OF SHOWERS ARE EXPECTED TO MOVE INTO THE
REGION MID MORNING AND IMPACT ALL SITES. THESE SHOWERS ARE
EXPECTED TO BE LESS IMPRESSIVE AS YESTERDAYS... AND HAVE LESS
RESTRICTIONS AS WELL. AFTER THE SHOWERS MOVE TO THE EAST... HIGH
PRESSURE WILL START TO BUILD INTO THE REGION RESULTING IN ALL
SITES BECOMING VFR.
WINDS WILL BE REMAIN SOUTHERLY AHEAD OF THE SHOWERS THIS
MORNING... AND MAY BECOME GUSTY AT TIME WITH GUSTS UP TO 30 KNOTS.
WINDS WILL TRANSITION TO WESTERLY FLOW THIS AFTERNOON... THEN
BECOME LIGHT AND VARIABLE NEAR SUNSET.
FRI...VFR.
SAT/SUN/MON...RESTRICTIONS POSSIBLE IN RAIN.
&&
.CLIMATE...
RECORD WARM TEMPERATURES NEXT 3 DAYS POSSIBLE...ESPECIALLY
DECEMBER 24TH.
WARMEST LOW TEMPERATURES TODAY AND MAYBE THE 25TH. RECORD WARM
HIGH, LOW, AND AVERAGE THE 24TH LIKELY FOR ALL 3 SITES. FORECAST
HIGHS IN THE MID AND UPPER 60S AND LOWS AT MIDNIGHT UPPER 40S TO
LOWER 50S. WILL BE CLOSE TO THE ALL TIME RECORD DECEMBER
TEMPERATURES. BINGHAMTON CLOSEST WITH 65 12/01/2006 AND 12/29/1984
AND 12/06/1982. SYRACUSE 72 12/06/2001. SCRANTON 71 12/01/2006.
TODAY WITH TEMPERATURES STEADY TO RISING THE REST OF TODAY RECORD
MAX MINS. BINGHAMTON 43 TODAY BREAKS THE RECORD OF 40 IN 2006.
SCRANTON 47 TODAY BREAKS THE RECORD OF 45 IN 1931.
SYRACUSE 42 TODAY TIES THE RECORD OF 42 IN 1931.
FOR THE 24TH MAX MIN AVE
BGM 55 2014 42 1965 48 2014
SYR 58 1965 48 1931 52 1931
AVP 62 1933 47 1931 53 1931
THE 25TH MAX MINIMUM TEMPERATURE AT SCRANTON WHERE THE WARM AIR
LINGERS. AGAIN PROBABLY A LOW AT MIDNIGHT THE END OF THE 25TH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MLJ/TAC
NEAR TERM...MLJ/TAC
SHORT TERM...MLJ
LONG TERM...MLJ
AVIATION...KAH
CLIMATE...
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
405 AM EST THU DEC 24 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE OFFSHORE THROUGH THE WEEKEND. A WEAK
COLD FRONT WILL APPROACH FROM THE NORTH TONIGHT THEN STALL NEAR
THE VIRGINIA BORDER FRIDAY. THE FRONT WILL LIFT BACK NORTH OVER
THE WEEKEND. A COLD FRONT WILL PUSH SOUTH THROUGH THE REGION
SUNDAY NIGHT. HIGH PRESSURE WILL EXTEND SOUTH INTO THE AREA MONDAY
THEN SLIDE OFFSHORE TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 330 AM THURSDAY...THE LINE OF HEAVY SHOWERS AND
THUNDERSTORMS MOVING ACROSS EASTERN SECTIONS HAS BEEN WEAKENING
OVER THE PAST COUPLE HOURS...WHICH IS ALSO EVIDENT IN IR
SATELLITE WITH CLOUD TOP WARMING. STILL SEEING SCATTERED TO
NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS LIFTING ACROSS THE
REGION...WITH STRONGEST STORMS PRESENTLY IN BEAUFORT CO LIFTING TO
THE NORTHEAST. HRRR HAS MOST OF THESE SHOWERS MOVING OFFSHORE BY
12Z WITH ONLY ISOLATED SHOWERS FOR THE REST OF THE DAY AS LOW PRES
OVER THE GREAT LAKES LIFT NORTH ALLOWING THE UPPER RIDGE AND SFC
HIGH PRES OVER THE WESTERN ATLANTIC WILL BEGIN TO BUILD WEST
TOWARD EASTERN NC DURING THE DAY. WHILE PWATS REMAIN ABOVE
CLIMATOLOGICAL MAX AND AN UNSTABLE AIRMASS REMAINS IN PLACE WITH
LI`S FORECAST TO BE AROUND -6C AND MUCAPE AROUND 2000-3000J/KG...
FORCING IN THE WAY OF EMBEDDED SHORTWAVES WILL BE ABSENT WITH
0-6KM SHEAR WEAKENING TO BELOW 30 KT AND ONLY EXPECT ISOLATED
SHOWERS OR THUNDERSTORMS THIS AFTERNOON AND HAVE LIMITED POPS TO
AROUND 30 PERCENT. THE BIG STORY WILL CONTINUE TO BE THE DEEP S/SW
FLOW BRINGING RECORD WARMTH ACROSS THE REGION. TEMPS ARE A FEW
DEGREES EITHER SIDE OF 70 EARLY THIS MORNING WHICH IS ABOUT 35
DEGREES ABOVE NORMAL LOW TEMPS FOR THIS DAY. HIGHS TODAY ARE
EXPECTED AROUND 80 ACROSS MANY INLAND LOCATIONS WITH MID TO UPPER
70S ALONG THE COAST. MOST CLIMATE LOCATIONS ARE EXPECTED TO SET
NEW RECORD MAX TEMPS AND RECORD HIGH MIN TEMPS FOR THE DAY AND
NEAR OR ABOVE THE ALL-TIME RECORD HIGH TEMPERATURES FOR THE MONTH
OF DECEMBER...SEE CLIMATE SECTION BELOW.
&&
.SHORT TERM /TONIGHT/...
AS OF 330 AM THURSDAY...UPPER RIDGING AND SFC HIGH PRES CONTINUE
TO BUILD INTO THE SOUTHEASTERN STATES TONIGHT WITH DEEPEST
MOISTURE BEING SHUNTED TO THE WEST AND NORTH. NOCTURNAL SHOWER
ACTIVITY EXPECTED TO BE MINIMAL WITH WEAKENING INSTABILITY AND
LITTLE UPPER LEVEL SUPPORT...THOUGH CANNOT RULE OUT AN ISOLATED
SHOWER SO WILL KEEP 20 POPS IN THE FORECAST. VERY WARM TEMPS WILL
CONTINUE WITH LOWS IN THE MID TO UPPER 60S AND MANY LOCATIONS MAY
SET RECORD HIGH MINIMUM TEMPERATURES AGAIN TONIGHT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 230 AM THU...EXPECT RECORD BREAKING WARMTH THROUGH THE
WEEKEND AS STRONG UPPER RIDGE OVER THE ATLANTIC BUILDS WEST TOWARD
THE COAST.
CHRISTMAS DAY THROUGH SUNDAY...VERY LITTLE PRECIP EXPECTED THRU
THIS PERIOD AS UPR RDG BUILDS CLOSER WHICH WILL ACT TO SUPPRESS
CONVECTION. CONT ISOLD POPS BUT MOST LOCATIONS WILL REMAIN DRY AND
WITH MORE SUN TEMPS WILL AGAIN BE VERY WARM REACHING AROUND 80
WARMER SPOTS THROUGH THE PERIOD. BALMY NIGHTITME LOWS IN THE 60S
EXPECTED.
MONDAY THROUGH WEDNESDAY...UPR RDG WILL BEGIN TO SHIFT BACK E
WITH MDLS SHOWING BACKDOOR FRONT DROPPING THRU THE REGION SUNDAY
NIGHT THEN LIFTING BACK N TUE AHEAD OF STRONGER APPROACHING
FRONT. CONT PREV FCST OF CHC POPS EARLY NEXT WEEK WITH STILL VERY
MILD TEMPS...MAINLY IN 60S MON WARMING BACK INTO THE 70S TUE/WED.
A COLD FRONT APPROACHES FROM THE WEST ON WEDNESDAY BUT TIMING OF
THE FRONTAL PASSAGE VERY MUCH IN QUESTION GIVEN THE POTENTIAL
ERROR IN THE DAY 7 FORECAST...WILL CONTINUE WITH CHC POPS THRU
MIDWEEK FOR NOW.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
SHORT TERM /THROUGH THURSDAY/...
AS OF 4 AM THURSDAY...MVFR CONDITIONS GENERALLY THE RULE WITH SCT
SHOWERS ACROSS RTES...THROUGH BRIEFLY SEEING CIGS LOWER TO IFR.
MODERATE SLY FLOW AROUND 5-10 KT THROUGH MID MORNING WHICH WILL
LIMIT FOG DEVELOPMENT. MOS GUIDANCE SUGGESTING MVFR CIGS
CONTINUING THROUGH ABOUT 15Z THIS MORNING. DISCOUNTED THE RUC/HRRR
THIS MORNING AS IT APPEARS TO BE AN OUTLIER IN DEVELOPING IFR
CONDITIONS AROUND 10Z THAT CONTINUES INTO THE AFTERNOON HOURS. THE
UPPER RIDGE OVER THE WESTERN ATLANTIC BUILDS TOWARD THE REGION
TODAY WHICH IS EXPECTED TO BRING A DECREASE IN SHOWERS AND
THUNDERSTORMS TODAY BUT A MOIST AND UNSTABLE AIRMASS WILL BE IN
PLACE AND CANNOT RULE OUT ISOLATED TO SCATTERED TSTMS THIS
AFTERNOON. GUSTY S/SW WINDS AROUND 15-20 KT EXPECTED AGAIN
TONIGHT. MODEL SOUNDINGS FAVORABLE FOR STRATUS DEVELOPMENT THIS
EVENING BRINING LIFR CONDITIONS AT THE TERMINALS WHICH IS
SUPPORTED IN MOS GUIDANCE. SW FLOW AROUND 5-10 KT EXPECTED TO
CONTINUE TONIGHT SO THINK MOS GUIDANCE IS TOO PESSIMISTIC WITH
VSBYS.
LONG TERM /FRI THROUGH MONDAY/...
AS OF 230 AM THU...WITH STRONG UPPER RIDGE BUILDING OVER THE
AREA, THE COVERAGE OF SHRA/TSRA WILL BE LIMITED THRU MUCH OF THE
UPCOMING WEEKEND. HOWEVER WITH LOW LEVELS REMAINING VERY MOIST
BOUTS OF SUB VFR STRATUS AND FOG WILL BE LIKELY LATE NIGHT/EARLY
MORN THRU SUNDAY. MAINLY VFR LATE MORN THRU EVENING HOURS WITH
ONLY SMALL CHC OF SHRA/TSRA THRU THE WEEKEND. A BACK DOOR COLD
FRONT DROPS THRU THE AREA SUNDAY NIGHT BRINGING A POTENTIAL FOR
LOW CLOUDS AND FOG BEHIND THE FRONT EARLY NEXT WEEK.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...LATEST OBS INDICATE S TO SSW WINDS
ACROSS THE EASTERN NC WATERS 15-25 KT WITH GUSTS AROUND 30 KT AT
DIAMOND BUOY. THE SURFACE RIDGE REMAINS CENTERED OFF THE
SOUTHEAST COAST WHILE A COLD FRONT APPROACHES FROM THE WEST.
SOUTHERLY WINDS WILL CONTINUE AROUND 15-25 KT THROUGH ABOUT MID
DAY, THEN SLOWLY DIMINISH AS THE PRESSURE GRADIENT RELAXES AS THE
AFOREMENTIONED FRONT STALLS ACROSS THE APPALACHIANS. SEAS
CURRENTLY AROUND 4-7 FT NORTH OF HATTERAS AND 6-10 FT SOUTH AND
THESE HEIGHTS WILL CONTINUE THROUGH ABOUT MID DAY AS WELL, THEN
GRADUALLY SUBSIDE THROUGH THE REST OF THE SHORT TERM. STRONGEST
WINDS/SEAS WILL OCCUR OVER THE COASTAL WATERS AND WILL MAINTAIN
THE SCA AS ADVERTISED. THE SOUNDS AND RIVERS ARE EXPECTED TO
REMAIN BELOW ADVISORY CRITERIA.
LONG TERM /FRI THROUGH MONDAY/...
AS OF 230 AM THU...WINDS AND SEAS WILL GRAD SUBSIDE FRI AS WEAK
FRONT STALLS TO THE NORTH AND SFC HIGH PRESSURE BUILDS OFF THE SE
COAST. CONT TO HAVE SCA ENDING CNTRL AND SRN WTRS BY MID DAY FRI. THE
PRESSURE GRADIENT WITH THE OFFSHORE HIGH WILL SUPPORT A LIGHT TO
MODERATE (10-15 KT) S/SW FLOW THRU MUCH OF THE UPCOMING WEEKEND
WITH SEAS MAINLY 3 TO 5 FT. MDLS MORE ROBUST WITH NE SURGE BEHIND
BACKDOOR FRONT MON WITH SPEEDS 15 TO 20 KTS AND SOME 6 FT SEAS
OUTER WTRS.
&&
.HYDROLOGY...
WIDESPREAD 3-4 INCHES OF RAIN HAS FALLEN ACROSS THE NC PIEDMONT
AND COASTAL PLAIN OVER THE PAST 3 DAYS WHICH IS CAUSING SEVERAL
MAIN STEM RIVERS TO RISE AND COULD SEE THEM REACH MINOR FLOOD
STAGE AND EARLY AS TONIGHT WITH OTHERS POSSIBLY REACHING FLOOD
STAGE THIS WEEKEND. THE LATEST RIVER FORECASTS HAVE CONTENTNEA
CREEK NEAR HOOKERTON RISING TO MINOR FLOOD STAGE BY LATE THIS
EVENING...THE NEUSE RIVER IN KINSTON SATURDAY AFTERNOON...AND THE
TAR RIVER AT GREENVILLE SATURDAY NIGHT. THE NE CAPE FEAR RIVER IS
EXPECTED TO CREST AT ACTION STAGE. A RIVER FLOOD WARNING MAY BE
ISSUED FOR CONTENTNEA CREEK NEAR HOOKERTON BY LATE THIS MORNING IF
THE LATEST RIVER FORECASTS CONTINUE TO INDICATE THE RIVER WILL
RISE ABOVE FLOOD STAGE.
&&
.CLIMATE...
RECORD BREAKING TEMPS EXPECTED THE REMAINDER OF CHRISTMAS WEEK.
THE FOLLOWING ARE RECORD HIGH MAX TEMPS, AS WELL AS RECORD HIGH
MIN TEMPS, FOR 12/24 THROUGH 12/27. ALSO INCLUDED ARE THE ALL-
TIME MAX HIGH, AND ALL-TIME MAX LOW TEMPS FOR DECEMBER.
RECORD HIGH MAX TEMPS F0R 12/24 THURSDAY
LOCATION TEMP/YEAR
NEW BERN 76/1964 (KEWN ASOS)
CAPE HATTERAS 72/1990 (KHSE ASOS)
GREENVILLE 73/1988 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 72/1990 (COOP - NOT KMRH ASOS)
KINSTON 78/2013 (COOP - NOT KISO AWOS)
JACKSONVILLE 74/1990 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/24 THURSDAY
LOCATION TEMP/YEAR
NEW BERN 55/2014 (KEWN ASOS)
CAPE HATTERAS 62/1986 (KHSE ASOS)
GREENVILLE 56/1956 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/1956 (COOP - NOT KMRH ASOS)
KINSTON 63/1990 (COOP - NOT KISO AWOS)
JACKSONVILLE 54/2014 (KNCA AWOS)
RECORD HIGH MAX TEMPS FOR 12/25 FRIDAY
LOCATION TEMP/YEAR
NEW BERN 78/1955 (KEWN ASOS)
CAPE HATTERAS 73/1964 (KHSE ASOS)
GREENVILLE 77/1964 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 74/1974 (COOP - NOT KMRH ASOS)
KINSTON 78/1932 (COOP - NOT KISO AWOS)
JACKSONVILLE 76/1974 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/25 FRIDAY
LOCATION TEMP/YEAR
NEW BERN 63/1964 (KEWN ASOS)
CAPE HATTERAS 61/1964 (KHSE ASOS)
GREENVILLE 59/1964 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/2008 (COOP - NOT KMRH ASOS)
KINSTON 61/1932 (COOP - NOT KISO AWOS)
JACKSONVILLE 61/1987 (KNCA AWOS)
RECORD HIGH MAX TEMPS FOR 12/26 SATURDAY
LOCATION TEMP/YEAR
NEW BERN 77/1987 (KEWN ASOS)
CAPE HATTERAS 74/1964 (KHSE ASOS)
GREENVILLE 77/1932 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 73/1982 (COOP - NOT KMRH ASOS)
KINSTON 77/1955 (COOP - NOT KISO AWOS)
JACKSONVILLE 82/1981 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/26 SATURDAY
LOCATION TEMP/YEAR
NEW BERN 65/1964 (KEWN ASOS)
CAPE HATTERAS 63/1964 (KHSE ASOS)
GREENVILLE 64/1932 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/1964 (COOP - NOT KMRH ASOS)
KINSTON 65/1964 (COOP - NOT KISO AWOS)
JACKSONVILLE 64/1964 (KNCA AWOS)
RECORD HIGH MAX TEMPS FOR 12/27 SUNDAY
LOCATION TEMP/YEAR
NEW BERN 74/1971 (KEWN ASOS)
CAPE HATTERAS 71/1982 (KHSE ASOS)
GREENVILLE 76/1964 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 74/1982 (COOP - NOT KMRH ASOS)
KINSTON 77/1964 (COOP - NOT KISO AWOS)
JACKSONVILLE 71/1982 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/27 SUNDAY
LOCATION TEMP/YEAR
NEW BERN 62/1949 (KEWN ASOS)
CAPE HATTERAS 62/1973 (KHSE ASOS)
GREENVILLE 62/1964 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 61/1949 (COOP - NOT KMRH ASOS)
KINSTON 62/1964 (COOP - NOT KISO AWOS)
JACKSONVILLE 60/1964 (KNCA AWOS)
**ALL-TIME RECORD HIGH MAXIMUM TEMPS FOR DECEMBER**
LOCATION TEMP/YEAR
NEW BERN 83/1971 (KEWN ASOS)
CAPE HATTERAS 78/1991 (KHSE ASOS)
GREENVILLE 82/1998 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 79/1998 (COOP - NOT KMRH ASOS)
KINSTON 87/1918 (COOP - NOT KISO AWOS)
JACKSONVILLE 82/1998 (KNCA AWOS)
**ALL-TIME RECORD HIGH MINIMUM TEMPS FOR DECEMBER**
LOCATION TEMP/YEAR
NEW BERN 69/2013 (KEWN ASOS)
CAPE HATTERAS 68/2015 (KHSE ASOS)
GREENVILLE 67/1991 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 67/2001 (COOP - NOT KMRH ASOS)
KINSTON 68/1991 (COOP - NOT KISO AWOS)
JACKSONVILLE 68/2013 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ150.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK
SHORT TERM...SK
LONG TERM...RF/BTC
AVIATION...RF/SK
MARINE...RF/SK
HYDROLOGY...MHX
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
250 PM EST THU DEC 24 2015
.SYNOPSIS...
A STRONG UPPER RIDGE WILL REMAIN ANCHORED OFF THE SOUTHEAST COAST
FOR THE NEXT WEEK. A SERIES OF SHORTWAVES RIDING ALONG THE WESTERN
PERIPHERY OF THE UPPER RIDGE WILL BRING BOUTS OF RAINFALL TO PA
THROUGH THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR LOOP AT 10Z SHOWING A WEAKENING LINE OF CONVECTION MOVING
THROUGH CENTRAL PA ALONG AXIS OF LL JET. SFC ANALYSIS INDICATES
COLD FRONT IS LAGGING TO THE WEST ACROSS EASTERN OHIO. RADAR
TRENDS AND LATEST HRRR SUPPORT THE IDEA OF THIS BAND OF SCT
SHOWERS PROGRESSES EASTWARD ACROSS THE REGION THIS MORNING...EXITING
ALL BUT EXTREME SE PA BY MIDDAY.
ALTHOUGH NO LIGHTNING STRIKES NOTED AT 10Z...WILL CONTINUE TO
MENTION A SLIGHT CHC OF THUNDER COINCIDENT WITH FROPA LATE
AM/EARLY AFTN ACROSS THE SE COUNTIES...WHERE MDLS DEVELOP SOME
MODEST CAPES.
GUIDANCE STILL SUGGESTING CLEARING SKIES WILL OVERSPREAD MUCH OF
CENTRAL PA BY AFTN...AS SFC RIDGING AND LOWER PWAT AIR MASS
ARRIVES BEHIND COLD FRONT. CLOUDS AND THE LINGERING CHC OF A
SHOWER MAY PERSIST THRU EVENING ACROSS THE SOUTHEAST IN THE
VICINITY OF STALLED OUT FRONT.
THE BIGGEST STORY OF THIS CHRISTMAS EVE REMAINS THE RECORD
BREAKING TEMPS. RECORDS HAVE ALREADY FALLEN AT KBFD/KIPT/KMDT AND
ARE VERY LIKELY TO FALL AT KAOO/KUNV. SREF PLUMES INDICATE STEADY
OR SLOWLY FALLING TEMPS TODAY ACROSS THE NW MTNS...WHERE FROPA
WILL OCCUR EARLY IN THE DAY. HOWEVER...READINGS SHOULD RISE
SEVERAL DEGREES ELSEWHERE...WITH SUPERBLEND AND ECME MOS
SUPPORTING MAX TEMPS FROM ARND 60F ACROSS THE NW MTNS...TO ARND
70F OVR THE LOWER SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WEAK RIDGE OF HIGH PRES AND ASSOC LOW PWAT AIR MASS SHOULD PROVIDE
FAIR WX FOR MOST OF CENTRAL PA TONIGHT. ACROSS THE SE
COUNTIES...CAN/T RULE OUT A FEW EVENING SHOWERS ASSOC WITH WEAK
WAVE OF LOW PRES RIDING ALONG STALLED FRONTAL BNDRY. LIKEWISE...A
WEAK SHORTWAVE RIDING ACROSS THE GRT LKS COULD SUPPORT AN ISOLD
SHOWER TOWARD DAWN OVR THE NW MTNS.
A WEAK WAVE RIDING ALONG STALLED FRONTAL BNDRY SOUTH OF PA COULD
SPREAD A BIT OF LGT RAIN INTO THE SOUTHERN PART OF THE STATE
DURING THE PM HOURS OF CHRISTMAS DAY. BLEND OF ENSEMBLE/OPER MDL
DATA SUPPORTS CHC POPS ACROSS THE SOUTHERN TIER AND SLGHT CHC OVR
THE NORTHERN HALF OF THE STATE. OTHERWISE...BIG STORY WILL
CONTINUE TO BE THE MILD WX. GEFS ENS MEAN 925 TEMPS NORTH OF FRONT REMAIN
VERY WARM FOR DECEMBER...LIKELY SUPPORTING MAX TEMPS FROM THE
L50S ACROSS THE NW MTNS...TO THE M60S OVR THE SE COUNTIES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A DEEP TROUGH MOVING THROUGH THE CENTRAL UNITED STATES AND LARGE
HIGH PRESSURE AT THE SFC OVER THE EAST COAST WILL DOMINATE THE
WEATHER THROUGH THE WEEKEND. THE STALLED FRONTAL BOUNDARY WILL
CONTINUE TO LIFT NORTH SATURDAY INTO SUNDAY AS A DEEPENING TROUGH
MOVES DOWN THROUGH THE SOUTHWESTERN UNITED STATES. THE INTERACTION
OF THE TROUGH...ALONG WITH THE LARGE HIGH LOCATED OVER THE
ATLANTICWILL COME IN THE FORM OF A QUASI- STATIONARY BOUNDARY
THAT WILL BRING THE NEXT BEST CHANCE FOR PRECIPITATION THIS
WEEKEND.
ALL MID TO LONG RANGE MODELS HAVE THE TROUGH FORM A CUT OFF LOW.
THE BIG QUESTION IS LOCATION HOWEVER THE GEFS/GFS/EC ARE COMING
MORE INTO AGREEMENT ON POSITION AND STRENGTH. ALL OPERATIONAL
RUNS DIG THE LOW THROUGH NORTHERN MEXICO BEFORE TRAVERSING TEXAS
AND LIFTING INTO THE SOUTHERN GREAT LAKES AND THEN MOVING EASTWARD
OVER THE RIDGE. THOUGH THE PREDOMINATE LOCATION IS OVER TEXAS. THE
MODELS ARE COMING INTO A COMMON SOLUTION FOR THE MOVEMENT OF THE
MOIST BOUNDARY THAT SHOULD EXTEND FROM THE TROUGH/LOW THROUGH NEW
ENGLAND. ALL PWATS ARE ANOMALOUS IN THE +3 TO +4 RANGE SO EXPECT
FOR MORE PRECIPITATION SATURDAY THROUGH SUNDAY.
ALL MED RANGE GUIDANCE TRACKS SFC LOW NORTH OF PA ACROSS THE E LAKES
SAT NIGHT...WITH TRAILING COLD FRONT COMING THRU PA EARLY SUNDAY.
COLD AIR DAMMING SCENARIO SATURDAY SHOULD RESULT IN A RELATIVE
COOL DAY /COMPARED TO THOSE RECENTLY/ WITH READINGS STUCK IN THE
40S OVR THE CENTRAL MTNS. WARMER CONDS EXPECTED SUNDAY...AS LOW
LVL COOL AIR IS SCOURED AHEAD OF COLD FRONT. GEFS 925 TEMPS AND EC
MOS SUGGEST TEMPS COULD APPROACH 70F ACROSS THE SE COUNTIES.
AFTER A VERY WARM WEEKEND...STRONG SIGNALS PERSIST FOR A BRIEF
PERIOD OF DRY/COOLER WX MONDAY...AS BULK OF MED RANGE GUIDANCE
INDICATES N STREAM SHORTWAVE WILL BEAT DOWN ATL RIDGE WITH SFC
HIGH BUILDING SE FROM ONTARIO. NEXT CHC OF PRECIP COMES MON
NIGHT/TUESDAY...WHEN ECENS/GEFS BOTH TRACK ANOTHER LOW WEST OF PA
THRU THE GRT LKS. HOWEVER...THIS TIME THERE WILL BE A SFC HIGH AND
ASSOC SUPPLY OF CHILLY LOW LVL AIR PARKED OVR NEW ENG. THUS...ODDS
FAVOR A WINTRY MIX OVR CENTRAL/NORTHERN COUNTIES...TURNING TO RAIN
TUESDAY. HAVE ADJUSTED THE POPS AND THE PRECIP TYPE ACCORDINGLY.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
VFR TO MVFR CIGS AND GENERALLY VFR VSBYS WILL CONTINUE ACROSS THE
REGION INTO THE LATE MORNING HOURS WITH SCATTERED SHOWERS RACING
NEWD AHEAD OF A WEAK COLD FRONT.
THE FRONT WILL CROSS THE WESTERN PENN AIRFIELDS LATE THIS
MORNING...AND THE SUSQ VALLEY TAF SITES EARLY THIS AFTERNOON.
LLWS WILL PERSIST FOR THE NEXT SVRL HOURS PRIOR TO THE ARRIVAL OF
THE COLD FRONT.
A BRIEF DROP TO THE IFR OR EVEN LIFR CIG IS EXPECTED IN THE 13-15Z
PERIOD INVOF KJST AS WINDS VEER TO THE SW THEN WSW...AND LIFT THE
MOIST AND SLIGHTLY COOLER AIR UP OVER THE LAUREL HIGHLANDS.
A FEW TO SVRL HOUR PERIOD OF GUSTY SW-WSW WINDS IS EXPECTED LATE
THIS MORNING AND THIS AFTERNOON...NEAR AND JUST IN THE WAKE OF THE
COLD FRONT.
EXPECT GRADUAL IMPROVEMENT DURING THE AFTERNOON HOURS WITH CLOUD
BASES LIFTING TO 5000 FT AGL OR HIGHER...AS WEAK HIGH PRESSURE
BUILDS TOWARD THE AREA.
OUTLOOK...
CHRISTMAS...NO SIG WX EXPECTED EARLY...MVFR CIGS WITH CHC R LATE
AFTERNOON AND AT NIGHT AS WARM FRONTAL FEATURE LIFTS BACK TO THE
NORTH.
SAT...MVFR/LCL IFR+ CIGS WITH CHC -SHRA.
SUN...RESTRICTIONS POSSIBLE AS FRONT AND -SHRA PASS.
MON...FAIR EARLY...CHC -SHRA LATE.
&&
.CLIMATE...
DECEMBER 2015 CONTINUES TO BE UNSEASONABLY MILD. ANOTHER ROUND OF
WELL ABOVE AVERAGE TEMPERATURES THIS WEEK WILL BRING POTENTIALLY
RECORD SETTING TEMPERATURES FOR WEDNESDAY AND THURSDAY /CHRISTMAS
EVE/. HERE ARE THE CURRENT RECORDS FOR WEDNESDAY THE 23RD AND
THURSDAY THE 24TH...
RECORD HIGH TEMPERATURES...
SITEWED RECORDTHU RECORDNORMAL
HARRISBURG65F (1990)62F (1990)39F
WILLIAMSPORT63F (1990)56F (1931)36F
ALTOONA62F (1957)62F (1965)36F
BRADFORD56F (1990)55F (1965)31F
STATE COLLEGE*65F (1933)63F (1933)36F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. WEDNESDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
RECORD HIGH LOW TEMPERATURES...
SITETHU RECORDFRI RECORDNORMAL
HARRISBURG49F (1931)45F (1891)25F
WILLIAMSPORT45F (2014)43F (1895)22F
ALTOONA41F (1972)42F (1987)21F
BRADFORD44F (1965)42F (1982)16F
STATE COLLEGE*45F (1931)46F (1893)22F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. THURSDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
WITH THE CONTINUED VERY MILD TEMPERATURES...DECEMBER 2015 IS ON
TRACK TO BE THE WARMEST DECEMBER ON RECORD AT ALL SITES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/CERU
AVIATION...LAMBERT/MARTIN
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
655 AM EST THU DEC 24 2015
.SYNOPSIS...
A STRONG UPPER RIDGE WILL REMAIN ANCHORED OFF THE SOUTHEAST COAST
FOR THE NEXT WEEK. A SERIES OF SHORTWAVES RIDING ALONG THE WESTERN
PERIPHERY OF THE UPPER RIDGE WILL BRING BOUTS OF RAINFALL TO PA
THROUGH THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR LOOP AT 10Z SHOWING A WEAKENING LINE OF CONVECTION MOVING
THROUGH CENTRAL PA ALONG AXIS OF LL JET. SFC ANALYSIS INDICATES
COLD FRONT IS LAGGING TO THE WEST ACROSS EASTERN OHIO. RADAR
TRENDS AND LATEST HRRR SUPPORT THE IDEA OF THIS BAND OF SCT
SHOWERS PROGRESSES EASTWARD ACROSS THE REGION THIS MORNING...EXITING
ALL BUT EXTREME SE PA BY MIDDAY.
ALTHOUGH NO LIGHTNING STRIKES NOTED AT 10Z...WILL CONTINUE TO
MENTION A SLIGHT CHC OF THUNDER COINCIDENT WITH FROPA LATE
AM/EARLY AFTN ACROSS THE SE COUNTIES...WHERE MDLS DEVELOP SOME
MODEST CAPES.
GUIDANCE STILL SUGGESTING CLEARING SKIES WILL OVERSPREAD MUCH OF
CENTRAL PA BY AFTN...AS SFC RIDGING AND LOWER PWAT AIR MASS
ARRIVES BEHIND COLD FRONT. CLOUDS AND THE LINGERING CHC OF A
SHOWER MAY PERSIST THRU EVENING ACROSS THE SOUTHEAST IN THE
VICINITY OF STALLED OUT FRONT.
THE BIGGEST STORY OF THIS CHRISTMAS EVE REMAINS THE RECORD
BREAKING TEMPS. RECORDS HAVE ALREADY FALLEN AT KBFD/KIPT/KMDT AND
ARE VERY LIKELY TO FALL AT KAOO/KUNV. SREF PLUMES INDICATE STEADY
OR SLOWLY FALLING TEMPS TODAY ACROSS THE NW MTNS...WHERE FROPA
WILL OCCUR EARLY IN THE DAY. HOWEVER...READINGS SHOULD RISE
SEVERAL DEGREES ELSEWHERE...WITH SUPERBLEND AND ECME MOS
SUPPORTING MAX TEMPS FROM ARND 60F ACROSS THE NW MTNS...TO ARND
70F OVR THE LOWER SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WEAK RIDGE OF HIGH PRES AND ASSOC LOW PWAT AIR MASS SHOULD PROVIDE
FAIR WX FOR MOST OF CENTRAL PA TONIGHT. ACROSS THE SE
COUNTIES...CAN/T RULE OUT A FEW EVENING SHOWERS ASSOC WITH WEAK
WAVE OF LOW PRES RIDING ALONG STALLED FRONTAL BNDRY. LIKEWISE...A
WEAK SHORTWAVE RIDING ACROSS THE GRT LKS COULD SUPPORT AN ISOLD
SHOWER TOWARD DAWN OVR THE NW MTNS.
A WEAK WAVE RIDING ALONG STALLED FRONTAL BNDRY SOUTH OF PA COULD
SPREAD A BIT OF LGT RAIN INTO THE SOUTHERN PART OF THE STATE
DURING THE PM HOURS OF CHRISTMAS DAY. BLEND OF ENSEMBLE/OPER MDL
DATA SUPPORTS CHC POPS ACROSS THE SOUTHERN TIER AND SLGHT CHC OVR
THE NORTHERN HALF OF THE STATE. OTHERWISE...BIG STORY WILL
CONTINUE TO BE THE MILD WX. GEFS ENS MEAN 925 TEMPS NORTH OF FRONT REMAIN
VERY WARM FOR DECEMBER...LIKELY SUPPORTING MAX TEMPS FROM THE L50S
ACROSS THE NW MTNS...TO THE M60S OVR THE SE COUNTIES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
ANOMALOUS UPPER RIDGE OFF THE EAST COAST WILL CONTINUE TO BE THE
DOMINANT PLAYER IN OUR WX THROUGH THE UPCOMING WEEKEND...EXTENDING
OUR STRETCH OF WELL ABOVE NORMAL TEMPS.
ALL MED RANGE GUIDANCE TRACKS SFC LOW NORTH OF PA ACROSS THE E
LAKES SAT NIGHT...WITH TRAILING COLD FRONT COMING THRU PA EARLY
SUNDAY. ALTHOUGH LG SCALE FORCING AND ASSOC SFC LOW APPEAR FAIRLY
WEAK...ABUNDANT MOISTURE /+3-4 SD GEFS PWATS/ IMPLY CLOUDY/WET WX
LATE FRIDAY INTO EARLY SUNDAY. COLD AIR DAMMING SCENARIO SATURDAY
SHOULD RESULT IN A RELATIVE COOL DAY /COMPARED TO THOSE RECENTLY/
WITH READINGS STUCK IN THE 40S OVR THE CENTRAL MTNS. WARMER CONDS
EXPECTED SUNDAY...AS LOW LVL COOL AIR IS SCOURED AHEAD OF COLD
FRONT. GEFS 925 TEMPS AND EC MOS SUGGEST TEMPS COULD APPROACH 70F
ACROSS THE SE COUNTIES.
AFTER A VERY WARM WEEKEND...STRONG SIGNALS FOR A BRIEF PERIOD OF
DRY/COOLER WX MONDAY...AS BULK OF MED RANGE GUIDANCE INDICATES N
STREAM SHORTWAVE WILL BEAT DOWN ATL RIDGE WITH SFC HIGH BUILDING SE
FROM ONTARIO. NEXT CHC OF PRECIP COMES MON NIGHT/TUESDAY...WHEN
ECENS/GEFS BOTH TRACK ANOTHER LOW WEST OF PA THRU THE GRT LKS.
HOWEVER...THIS TIME THERE WILL BE A SFC HIGH AND ASSOC SUPPLY OF
CHILLY LOW LVL AIR PARKED OVR NEW ENG. THUS...ODDS FAVOR A WINTRY
MIX OVR CENTRAL/NORTHERN COUNTIES...TURNING TO RAIN TUESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
VFR TO MVFR CIGS AND GENERALLY VFR VSBYS WILL CONTINUE ACROSS THE
REGION INTO THE LATE MORNING HOURS WITH SCATTERED SHOWERS RACING
NEWD AHEAD OF A WEAK COLD FRONT.
THE FRONT WILL CROSS THE WESTERN PENN AIRFIELDS LATE THIS
MORNING...AND THE SUSQ VALLEY TAF SITES EARLY THIS AFTERNOON.
LLWS WILL PERSIST FOR THE NEXT SVRL HOURS PRIOR TO THE ARRIVAL OF
THE COLD FRONT.
A BRIEF DROP TO THE IFR OR EVEN LIFR CIG IS EXPECTED IN THE 13-15Z
PERIOD INVOF KJST AS WINDS VEER TO THE SW THEN WSW...AND LIFT THE
MOIST AND SLIGHTLY COOLER AIR UP OVER THE LAUREL HIGHLANDS.
A FEW TO SVRL HOUR PERIOD OF GUSTY SW-WSW WINDS IS EXPECTED LATE
THIS MORNING AND THIS AFTERNOON...NEAR AND JUST IN THE WAKE OF THE
COLD FRONT.
EXPECT GRADUAL IMPROVEMENT DURING THE AFTERNOON HOURS WITH CLOUD
BASES LIFTING TO 5000 FT AGL OR HIGHER...AS WEAK HIGH PRESSURE
BUILDS TOWARD THE AREA.
OUTLOOK...
CHRISTMAS...NO SIG WX EXPECTED EARLY...MVFR CIGS WITH CHC R LATE
AFTERNOON AND AT NIGHT AS WARM FRONTAL FEATURE LIFTS BACK TO THE
NORTH.
SAT...MVFR/LCL IFR+ CIGS WITH CHC -SHRA.
SUN...RESTRICTIONS POSSIBLE AS FRONT AND -SHRA PASS.
MON...FAIR EARLY...CHC -SHRA LATE.
&&
.CLIMATE...
DECEMBER 2015 CONTINUES TO BE UNSEASONABLY MILD. ANOTHER ROUND OF
WELL ABOVE AVERAGE TEMPERATURES THIS WEEK WILL BRING POTENTIALLY
RECORD SETTING TEMPERATURES FOR WEDNESDAY AND THURSDAY /CHRISTMAS
EVE/. HERE ARE THE CURRENT RECORDS FOR WEDNESDAY THE 23RD AND
THURSDAY THE 24TH...
RECORD HIGH TEMPERATURES...
SITEWED RECORDTHU RECORDNORMAL
HARRISBURG65F (1990)62F (1990)39F
WILLIAMSPORT63F (1990)56F (1931)36F
ALTOONA62F (1957)62F (1965)36F
BRADFORD56F (1990)55F (1965)31F
STATE COLLEGE*65F (1933)63F (1933)36F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. WEDNESDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
RECORD HIGH LOW TEMPERATURES...
SITETHU RECORDFRI RECORDNORMAL
HARRISBURG49F (1931)45F (1891)25F
WILLIAMSPORT45F (2014)43F (1895)22F
ALTOONA41F (1972)42F (1987)21F
BRADFORD44F (1965)42F (1982)16F
STATE COLLEGE*45F (1931)46F (1893)22F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. THURSDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
WITH THE CONTINUED VERY MILD TEMPERATURES...DECEMBER 2015 IS ON
TRACK TO BE THE WARMEST DECEMBER ON RECORD AT ALL SITES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/CERU
AVIATION...LAMBERT/MARTIN
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
605 AM EST THU DEC 24 2015
.SYNOPSIS...
A STRONG UPPER RIDGE WILL REMAIN ANCHORED OFF THE SOUTHEAST COAST
FOR THE NEXT WEEK. A SERIES OF SHORTWAVES RIDING ALONG THE WESTERN
PERIPHERY OF THE UPPER RIDGE WILL BRING BOUTS OF RAINFALL TO PA
THROUGH THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR LOOP AT 10Z SHOWING A WEAKENING LINE OF CONVECTION MOVING
THROUGH CENTRAL PA ALONG AXIS OF LL JET. SFC ANALYSIS INDICATES
COLD FRONT IS LAGGING TO THE WEST ACROSS EASTERN OHIO. RADAR
TRENDS AND LATEST HRRR SUPPORT THE IDEA OF THIS BAND OF SCT
SHOWERS PROGRESSES EASTWARD ACROSS THE REGION THIS MORNING...EXITING
ALL BUT EXTREME SE PA BY MIDDAY.
ALTHOUGH NO LIGHTNING STRIKES NOTED AT 10Z...WILL CONTINUE TO
MENTION A SLIGHT CHC OF THUNDER COINCIDENT WITH FROPA LATE
AM/EARLY AFTN ACROSS THE SE COUNTIES...WHERE MDLS DEVELOP SOME
MODEST CAPES.
GUIDANCE STILL SUGGESTING CLEARING SKIES WILL OVERSPREAD MUCH OF
CENTRAL PA BY AFTN...AS SFC RIDGING AND LOWER PWAT AIR MASS
ARRIVES BEHIND COLD FRONT. CLOUDS AND THE LINGERING CHC OF A
SHOWER MAY PERSIST THRU EVENING ACROSS THE SOUTHEAST IN THE
VICINITY OF STALLED OUT FRONT.
THE BIGGEST STORY OF THIS CHRISTMAS EVE REMAINS THE RECORD
BREAKING TEMPS. RECORDS HAVE ALREADY FALLEN AT KBFD/KIPT/KMDT AND
ARE VERY LIKELY TO FALL AT KAOO/KUNV. SREF PLUMES INDICATE STEADY
OR SLOWLY FALLING TEMPS TODAY ACROSS THE NW MTNS...WHERE FROPA
WILL OCCUR EARLY IN THE DAY. HOWEVER...READINGS SHOULD RISE
SEVERAL DEGREES ELSEWHERE...WITH SUPERBLEND AND ECME MOS
SUPPORTING MAX TEMPS FROM ARND 60F ACROSS THE NW MTNS...TO ARND
70F OVR THE LOWER SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WEAK RIDGE OF HIGH PRES AND ASSOC LOW PWAT AIR MASS SHOULD PROVIDE
FAIR WX FOR MOST OF CENTRAL PA TONIGHT. ACROSS THE SE
COUNTIES...CAN/T RULE OUT A FEW EVENING SHOWERS ASSOC WITH WEAK
WAVE OF LOW PRES RIDING ALONG STALLED FRONTAL BNDRY. LIKEWISE...A
WEAK SHORTWAVE RIDING ACROSS THE GRT LKS COULD SUPPORT AN ISOLD
SHOWER TOWARD DAWN OVR THE NW MTNS.
A WEAK WAVE RIDING ALONG STALLED FRONTAL BNDRY SOUTH OF PA COULD
SPREAD A BIT OF LGT RAIN INTO THE SOUTHERN PART OF THE STATE
DURING THE PM HOURS OF CHRISTMAS DAY. BLEND OF ENSEMBLE/OPER MDL
DATA SUPPORTS CHC POPS ACROSS THE SOUTHERN TIER AND SLGHT CHC OVR
THE NORTHERN HALF OF THE STATE. OTHERWISE...BIG STORY WILL
CONTINUE TO BE THE MILD WX. GEFS ENS MEAN 925 TEMPS NORTH OF FRONT REMAIN
VERY WARM FOR DECEMBER...LIKELY SUPPORTING MAX TEMPS FROM THE L50S
ACROSS THE NW MTNS...TO THE M60S OVR THE SE COUNTIES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
ANOMALOUS UPPER RIDGE OFF THE EAST COAST WILL CONTINUE TO BE THE
DOMINANT PLAYER IN OUR WX THROUGH THE UPCOMING WEEKEND...EXTENDING
OUR STRETCH OF WELL ABOVE NORMAL TEMPS.
ALL MED RANGE GUIDANCE TRACKS SFC LOW NORTH OF PA ACROSS THE E
LAKES SAT NIGHT...WITH TRAILING COLD FRONT COMING THRU PA EARLY
SUNDAY. ALTHOUGH LG SCALE FORCING AND ASSOC SFC LOW APPEAR FAIRLY
WEAK...ABUNDANT MOISTURE /+3-4 SD GEFS PWATS/ IMPLY CLOUDY/WET WX
LATE FRIDAY INTO EARLY SUNDAY. COLD AIR DAMMING SCENARIO SATURDAY
SHOULD RESULT IN A RELATIVE COOL DAY /COMPARED TO THOSE RECENTLY/
WITH READINGS STUCK IN THE 40S OVR THE CENTRAL MTNS. WARMER CONDS
EXPECTED SUNDAY...AS LOW LVL COOL AIR IS SCOURED AHEAD OF COLD
FRONT. GEFS 925 TEMPS AND EC MOS SUGGEST TEMPS COULD APPROACH 70F
ACROSS THE SE COUNTIES.
AFTER A VERY WARM WEEKEND...STRONG SIGNALS FOR A BRIEF PERIOD OF
DRY/COOLER WX MONDAY...AS BULK OF MED RANGE GUIDANCE INDICATES N
STREAM SHORTWAVE WILL BEAT DOWN ATL RIDGE WITH SFC HIGH BUILDING SE
FROM ONTARIO. NEXT CHC OF PRECIP COMES MON NIGHT/TUESDAY...WHEN
ECENS/GEFS BOTH TRACK ANOTHER LOW WEST OF PA THRU THE GRT LKS.
HOWEVER...THIS TIME THERE WILL BE A SFC HIGH AND ASSOC SUPPLY OF
CHILLY LOW LVL AIR PARKED OVR NEW ENG. THUS...ODDS FAVOR A WINTRY
MIX OVR CENTRAL/NORTHERN COUNTIES...TURNING TO RAIN TUESDAY.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
FRAGMENTED REMNANTS OF THE WED EVENING SQUALL LINE ACROSS THE OHIO
VALLEY WAS MOVING OVER THE NW AND NORTH-CENTRAL MTNS OF PENN EARLY
TODAY AS A SFC TROUGH. THIS FEATURE WAS ACCOMPANIED BY AN AREA OF
MDT-HVY RAIN SHOWERS WITH A FEW EMBEDDED...FAST MOVING AND LOW-
TOPPED TSRA. BRIEF 25-30 KT WIND GUSTS FROM THE WEST OR NW ARE
POSSIBLE AT KUNV AND KIPT THROUGH 0830Z.
MAINLY MVFR CIGS AND VFR VSBYS WILL CONTINUE ACROSS THE SUSQ
VALLEY AND CENTRAL MTNS THIS MORNING...WHILE VFR TO MVFR WILL BE
FOUND OVER THE WESTERN TERMINALS KJST AND KBFD...WITH A LIKELY
DROP TO THE IFR OR EVEN LIFR CIG RANGE BY 12Z IN THE WAKE OF THE
AFOREMENTIONED SFC TROUGH AS WINDS BECOME SSWRLY THIS MORNING.
LOW LVL WIND SHEAR WILL OCCUR THROUGH AROUND 12Z OVER THE WESTERN
PENN AIRFIELDS...AND WILL CONTINUE UNTIL 14-16Z OVER THE CENTRAL
AND EASTERN PENN TAF SITES.
EXPECT SOME IMPROVEMENT DURING THE DAY TODAY...AS WEAK HIGH
PRESSURE BUILDS TOWARD THE AREA.
OUTLOOK...
CHRISTMAS...NO SIG WX EXPECTED EARLY...MVFR CIGS WITH CHC R LATE
AFTERNOON AND AT NIGHT AS WARM FRONTAL FEATURE LIFTS BACK TO THE
NORTH.
SAT...MVFR/LCL IFR+ CIGS WITH CHC -SHRA.
SUN...RESTRICTIONS POSSIBLE AS FRONT AND -SHRA PASS.
MON...FAIR EARLY...CHC -SHRA LATE.
&&
.CLIMATE...
DECEMBER 2015 CONTINUES TO BE UNSEASONABLY MILD. ANOTHER ROUND OF
WELL ABOVE AVERAGE TEMPERATURES THIS WEEK WILL BRING POTENTIALLY
RECORD SETTING TEMPERATURES FOR WEDNESDAY AND THURSDAY /CHRISTMAS
EVE/. HERE ARE THE CURRENT RECORDS FOR WEDNESDAY THE 23RD AND
THURSDAY THE 24TH...
RECORD HIGH TEMPERATURES...
SITEWED RECORDTHU RECORDNORMAL
HARRISBURG65F (1990)62F (1990)39F
WILLIAMSPORT63F (1990)56F (1931)36F
ALTOONA62F (1957)62F (1965)36F
BRADFORD56F (1990)55F (1965)31F
STATE COLLEGE*65F (1933)63F (1933)36F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. WEDNESDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
RECORD HIGH LOW TEMPERATURES...
SITETHU RECORDFRI RECORDNORMAL
HARRISBURG49F (1931)45F (1891)25F
WILLIAMSPORT45F (2014)43F (1895)22F
ALTOONA41F (1972)42F (1987)21F
BRADFORD44F (1965)42F (1982)16F
STATE COLLEGE*45F (1931)46F (1893)22F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. THURSDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
WITH THE CONTINUED VERY MILD TEMPERATURES...DECEMBER 2015 IS ON
TRACK TO BE THE WARMEST DECEMBER ON RECORD AT ALL SITES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/CERU
AVIATION...LAMBERT/MARTIN
CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
455 PM EST THU DEC 24 2015
.SYNOPSIS...
DEEP MOISTURE WILL FOCUS MAINLY ON THE SOUTHERN APPALACHIANS TONIGHT
BEFORE GRADUALLY RETREATING TO THE NORTH AND WEST FRIDAY THROUGH THE
WEEKEND. HIGH PRESSURE WILL BUILD IN FROM THE SOUTHEAST OVER THE
WEEKEND...BUT WITH CONTINUED LOW LEVEL MOISTURE IN PLACE. A STRONG
LOW PRESSURE SYSTEM MAY APPROACH FROM THE WEST EARLY NEXT WEEK TO
BRING ANOTHER ROUND OF HEAVY RAINFALL TO THE AREA.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 445 PM...STILL WORKING OFF THAT PRECIP LULL LATE THIS
AFTERNOON. STRONGER...POSSIBLY SEVERE...CONVECTION WAS RACING OUT
EASTWARD ACROSS E CENTRAL GA AND INTO THE MIDLANDS OF SC AHEAD OF
THE MAIN PRECIP BAND. THIS MIGHT BE HELPING TO KILL OFF THE PRECIP
ON THE BACK SIDE...WHICH WAS MOVING INTO NE GEORGIA AND THE UPSTATE.
WILL CUT BACK TEMPORARILY ON THE PRECIP CHANCE OVER THE NC MTNS AND
FOOTHILLS INTO THE EARLY EVENING. TIME WILL TELL SHORTLY IF
SCATTERED CONVECTION DEVELOPING AROUND METRO ATL WILL MAKE A RUN
TOWARD THE AREA AROUND SUNSET. THE HRRR IS NOT REALLY IMPRESSED.
MIGHT HAVE TO CUT BACK EVEN FURTHER ON NEXT UPDATE. DEEP LAYER SW
FLOW WILL PERSIST THROUGH THE PERIOD AS WEAK H5 VORT LOBES MOVE
THROUGH ALOFT. THE BEST MOISTURE WILL FOCUS BACK PRIMARILY ON THE
SRN APPALACHIANS TONIGHT THROUGH FRIDAY AS HEIGHTS SLOWLY BUILD
ACROSS THE SE. THE LOW LEVEL FLOW WILL VEER FARTHER SW AND FOCUS THE
UPSLOPE FORCING AROUND THE FAR SRN AND SW MTNS. THE FLASH FLOOD
WATCH WILL BE EXTENDED FOR THE MOUNTAINS AND ADJACENT FOOTHILLS
THROUGH FRIDAY. INSTABILITY FOR SCT CONVECTION WILL REMAIN BEST IN
PIEDMONT SECTIONS ON FRIDAY...BUT WITH COVERAGE PROBABLY TOO LOW TO
WARRANT A LONGER DURATION WATCH EXPANSITION THERE. MINS WILL BE 30
DEGREES ABOVE CLIMO TONIGHT WITH MAXES 20 DEGREES ABOVE CLIMO FRIDAY
AFTN.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AT 230 PM EST THURSDAY...A PROMINENT SE RIDGE WILL FORM OVER THE
WEEKEND AS THE SRN STREAM SYSTEM APPROACHING W TX CREATES TREMENDOUS
HEIGHT FALLS WELL TO THE WEST. THE DEEPER MOISTURE WILL GET PUSHED N
AND WEST OF THE FORECAST AREA OVER THE WEEKEND. HOWEVER...LOW LEVEL
UPGLIDE WILL PERSIST OVER WRN SECTIONS AND PERMIT CONTINUED LOW END
SHOWER CHANCES. EXPECT WARM TEMPS AND INSTABILITY THROUGH THE
WEEKEND UNDER THE RIDGE...WITH ISOLD TSTMS POSSIBLE. MAXES WILL BE
IN THE 70S...WITH HIGHER ELEVATION 60S. MINS WILL BE IN THE 50S MTNS
AND 60S PIEDMONT WITH CONTINUED WARM CONDITIONS THROUGH SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM THURSDAY...THE MEDIUM RANGE BEGINS 00Z MONDAY WITH AN
ATLANTIC SURFACE RIDGE BREAKING DOWN AND AN UPPER LEVEL TROUGH AND
ASSOCIATED CLOSED LOW DEEPENING OVER THE SOUTHERN PLAINS. THE LOW
WILL TRANSLATE ACROSS THE MIDWEST MONDAY AND TUESDAY...BRINGING A
SURFACE COLD FRONT JUST TO THE WEST OF THE AREA.
MOIST SOUTH/SOUTHEASTERLY LOW LEVEL FLOW WILL PROVIDE PLENTIFUL
MOISTURE AS A SURFACE WARM FRONT DRAGS NORTH OF THE CWA MONDAY...AND
A SURFACE HIGH POSITIONED OVER THE NORTHEAST CONUS WILL ALLOW A
WEDGE TO BRIEFLY BUILD IN LATE MONDAY THROUGH THE DAY ON TUESDAY.
THE PRESENCE OF THE WEDGE COMBINED WITH THE MOIST SOUTHEASTERLY FLOW
WILL PROVIDE A WINDOW MONDAY NIGHT AND TUESDAY FOR SOME POTENTIAL
ISENTROPIC UPGLIDE...SO HAVE RAISED POPS TO LIKELY FOR MOST OF THE
AREA DURING THAT TIME. THE SURFACE COLD FRONT WILL PASS BY LATE
TUESDAY EVENING...SO POPS ARE TAPERED TO CHANCE TUESDAY NIGHT.
THE LULL IN POPS WILL BE BRIEF TUESDAY NIGHT...AS A FRONTAL BOUNDARY
OVER THE GULF WILL LIFT NORTHWARD TO APPROACH OUR AREA ON WEDNESDAY.
A MOIST TAP OF GULF AIR NEVER REALLY CUTS OFF AFTER THE PREVIOUS
FRONTAL PASSAGE...BUT A LACK OF IMPRESSIVE UPPER LIFT OR OTHER
FORCING WILL KEEP POPS JUST BELOW THE LIKELY CATEGORY. A SECOND
UPPER TROUGH/WEAK LOW WILL PASS WEDNESDAY NIGHT...WITH SOMEWHAT
DRIER AIR ALLOWED TO MOVE IN BEHIND THE FRONT THURSDAY AND FRIDAY.
POPS WILL FINALLY BE LOWERED SUBSTANTIALLY OVERNIGHT THURSDAY AND
INTO FRIDAY MORNING. THERE IS STILL DISAGREEMENT ON THE DEPTH OF THE
FINAL UPPER TROUGH THAT WILL PASS THURSDAY AND FRIDAY...BUT OVERALL
HEIGHT FALLS WILL LEAD TO A GRADUAL DECLINE IN TEMPERATURES TO JUST
5 TO 10 DEGREES ABOVE NORMAL BY FRIDAY.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
AT KCLT...CONTINUED SHRA WILL AFFECT THE AIRFIELD THROUGH THE AFTN
AND EVENING HOURS...BUT WITH TSRA MUCH MORE DIFFICULT TO TIME.
ANTICIPATE MAINLY MVFR CIGS ON S TO SW MIXING WITH OCCASIONAL
GUSTS...AND THEN A RETURN TO IFR THEN LIFR CIGS OVERNIGHT AS THE
MIXING AND RAINFALL LESSEN. PERISTENT SRLY FLOW SHOULD KEEP VSBY
FROM CRASHING DESPITE THE VERY MOIST GROUND. MVFR CIGS/VSBY WILL BE
VERY SLOW TO IMPROVE THROUGH LATE MORNING FRIDAY.
ELSEWHERE...EXPECT CONTINUED FAIRLY WIDESPREAD SHRA ACROSS THE MTN
AND FOOTHILL TAF SITES...BUT WITH CONVECTIVE CHANCES APPEARING TO BE
A BIT LESS. THE LATEST HRRR DOES BRING SOME CONVECTION BACK TONIGHT
WHICH WILL NEED TO BE MONITORED FOR TEMPO TSRA AFTER 05Z.
OTHERWISE...MVFR TO VFR CIGS EARLY WILL RETURN TO IFR THEN LIFR
OVERNIGHT IN THE MOIST SRLY FLOW. UPSLOPE SHRA ARE LIKELY AT TIMES
THROUGH 18Z FRIDAY.
OUTLOOK...DEEP LAYER MOISTURE AHEAD OF A STALLED FRONT WILL PERSIST
OVER AT LEAST THE MOUNTAINS THROUGH LATE FRIDAY...BEFORE SOME MINOR
DRYING OCCURS OVER THE WEEKEND. SRLY UPSLOPE FLOW WILL PERSIST OVER
THE WEEKEND...HOWEVER...WITH SOME RESTRICTIONS ONCE AGAIN LIKELY.
ANOTHER WET SYSTEM WILL APPROACH FROM THE WEST EARLY NEXT WEEK.
CONFIDENCE TABLE...
22-04Z 04-10Z 10-16Z 16-18Z
KCLT MED 78% MED 72% MED 72% HIGH 84%
KGSP MED 75% MED 75% HIGH 83% HIGH 85%
KAVL MED 75% MED 75% HIGH 94% HIGH 100%
KHKY HIGH 89% LOW 58% HIGH 80% HIGH 84%
KGMU HIGH 80% HIGH 80% HIGH 86% HIGH 81%
KAND HIGH 89% MED 78% HIGH 86% HIGH 88%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.HYDROLOGY...
ONGOING AND DEVELOPING HYDRO ISSUES WILL BE EXACERBATED BY
ADDITIONAL MODERATE TO HEAVY RAINFALL IN THE EXTREME SOUTHERN
APPALCHIANS TONIGHT INTO FRIDAY. ADDITIONAL QPF OF 1.5 TO 2.5 INCHES
ARE POSSIBLE IN THE SRN ESCARPMENT AREAS...WITH 1 TO 2 INCHES
POSSIBLE ACROSS THE FOOTHILLS...AND AMOUNTS FALLING OFF QUICKLY
FARTHER EAST INTO THE PIEDMONT. LOCALLY HEAVY RAINFALL COULD
REDEVELOP JUST ABOUT ANYWHERE WITH SCATTERED CONVECTION...BUT THE NC
MOUNTAINS...GA MTNS...AND IMMEDIATELY ADJACENT FOOTHILLS SHOULD HAVE
THE LONGEST DURATION HYDRO ISSUES THROUGH FRIDAY. THE FLASH FLOOD
WATCH WILL BE EXTENDED IN THESE AREAS.
&&
.CLIMATE...
DAILY MAXIMUM TEMPERATURE RECORDS FOR FRIDAY DECEMBER 25...
AVL 67 1955...1944...1904
CLT 77 1955
GSP 78 1955
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR FRIDAY DEC 25...
AVL 55 1982
CLT 62 1932
GSP 56 1964
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR GAZ010-017-018-
026-028.
FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR GAZ029.
NC...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR NCZ033-035-
048>053-058-059-062>065-501>510.
FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR NCZ036-037-
056-057-068>072-082.
SC...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR SCZ001>007-010.
FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR SCZ008-009-
011>014-019.
&&
$$
SYNOPSIS...HG
NEAR TERM...HG/PM
SHORT TERM...HG
LONG TERM...LEV
AVIATION...HG
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
253 PM EST THU DEC 24 2015
.SYNOPSIS...
DEEP MOISTURE WILL FOCUS MAINLY ON THE SOUTHERN APPALACHIANS TONIGHT
BEFORE GRADUALLY RETREATING TO THE NORTH AND WEST FRIDAY THROUGH THE
WEEKEND. HIGH PRESSURE WILL BUILD IN FROM THE SOUTHEAST OVER THE
WEEKEND...BUT WITH CONTINUED LOW LEVEL MOISTURE IN PLACE. A STRONG
LOW PRESSURE SYSTEM MAY APPROACH FROM THE WEST EARLY NEXT WEEK TO
BRING ANOTHER ROUND OF HEAVY RAINFALL TO THE AREA.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 225 PM EST...PRECIPITATION RATES EXPERIENCED A BRIEF LULL THIS
AFTERNOON...BUT BETTER RATES ARE STEADILY RETURNING FROM THE MORE
UNSTABLE AIR ACROSS CENTRAL GA. THE POTENTIAL FOR STRONG CONVECTION
DOES NOT APPEAR IMPRESSIVE AS THE LOW LEVEL JET HAS WEAKENED
SUFFICIENTLY...BUT THUNDER WILL BE POSSIBLE GIVEN SB CAPE VALUES OF
500 TO 1500 J/KG MOST AREAS EAST OF THE MTNS. DEEP LAYER SW FLOW
WILL PERSIST THROUGH THE PERIOD AS WEAK H5 VORT LOBES MOVE THROUGH
ALOFT. THE BEST MOISTURE WILL FOCUS PRIMARILY ON THE SRN
APPALACHIANS TONIGHT THROUGH FRIDAY AS HEIGHTS SLOWLY BUILD ACROSS
THE SE. THE LOW LEVEL FLOW WILL VEER FARTHER SW AND FOCUS THE
UPSLOPE FORCING AROUND THE FAR SRN AND SW MTNS. THE FLASH FLOOD
WATCH WILL BE EXTENDED FOR THE MOUNTAINS AND ADJACENT FOOTHILLS
THROUGH FRIDAY. INSTABILITY FOR SCT CONVECTION WILL REMAIN BEST IN
PIEDMONT SECTIONS ON FRIDAY...BUT WITH COVERAGE PROBABLY TOO LOW TO
WARRANT A LONGER DURATION WATCH EXPANSITION THERE. MINS WILL BE 30
DEGREES ABOVE CLIMO TONIGHT WITH MAXES 20 DEGREES ABOVE CLIMO FRIDAY
AFTN.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AT 230 PM EST THURSDAY...A PROMINENT SE RIDGE WILL FORM OVER THE
WEEKEND AS THE SRN STREAM SYSTEM APPROACHING W TX CREATES TREMENDOUS
HEIGHT FALLS WELL TO THE WEST. THE DEEPER MOISTURE WILL GET PUSHED N
AND WEST OF THE FORECAST AREA OVER THE WEEKEND. HOWEVER...LOW LEVEL
UPGLIDE WILL PERSIST OVER WRN SECTIONS AND PERMIT CONTINUED LOW END
SHOWER CHANCES. EXPECT WARM TEMPS AND INSTABILITY THROUGH THE
WEEKEND UNDER THE RIDGE...WITH ISOLD TSTMS POSSIBLE. MAXES WILL BE
IN THE 70S...WITH HIGHER ELEVATION 60S. MINS WILL BE IN THE 50S MTNS
AND 60S PIEDMONT WITH CONTINUED WARM CONDITIONS THROUGH SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM THURSDAY...THE MEDIUM RANGE BEGINS 00Z MONDAY WITH AN
ATLANTIC SURFACE RIDGE BREAKING DOWN AND AN UPPER LEVEL TROUGH AND
ASSOCIATED CLOSED LOW DEEPENING OVER THE SOUTHERN PLAINS. THE LOW
WILL TRANSLATE ACROSS THE MIDWEST MONDAY AND TUESDAY...BRINGING A
SURFACE COLD FRONT JUST TO THE WEST OF THE AREA.
MOIST SOUTH/SOUTHEASTERLY LOW LEVEL FLOW WILL PROVIDE PLENTIFUL
MOISTURE AS A SURFACE WARM FRONT DRAGS NORTH OF THE CWA MONDAY...AND
A SURFACE HIGH POSITIONED OVER THE NORTHEAST CONUS WILL ALLOW A
WEDGE TO BRIEFLY BUILD IN LATE MONDAY THROUGH THE DAY ON TUESDAY.
THE PRESENCE OF THE WEDGE COMBINED WITH THE MOIST SOUTHEASTERLY FLOW
WILL PROVIDE A WINDOW MONDAY NIGHT AND TUESDAY FOR SOME POTENTIAL
ISENTROPIC UPGLIDE...SO HAVE RAISED POPS TO LIKELY FOR MOST OF THE
AREA DURING THAT TIME. THE SURFACE COLD FRONT WILL PASS BY LATE
TUESDAY EVENING...SO POPS ARE TAPERED TO CHANCE TUESDAY NIGHT.
THE LULL IN POPS WILL BE BRIEF TUESDAY NIGHT...AS A FRONTAL BOUNDARY
OVER THE GULF WILL LIFT NORTHWARD TO APPROACH OUR AREA ON WEDNESDAY.
A MOIST TAP OF GULF AIR NEVER REALLY CUTS OFF AFTER THE PREVIOUS
FRONTAL PASSAGE...BUT A LACK OF IMPRESSIVE UPPER LIFT OR OTHER
FORCING WILL KEEP POPS JUST BELOW THE LIKELY CATEGORY. A SECOND
UPPER TROUGH/WEAK LOW WILL PASS WEDNESDAY NIGHT...WITH SOMEWHAT
DRIER AIR ALLOWED TO MOVE IN BEHIND THE FRONT THURSDAY AND FRIDAY.
POPS WILL FINALLY BE LOWERED SUBSTANTIALLY OVERNIGHT THURSDAY AND
INTO FRIDAY MORNING. THERE IS STILL DISAGREEMENT ON THE DEPTH OF THE
FINAL UPPER TROUGH THAT WILL PASS THURSDAY AND FRIDAY...BUT OVERALL
HEIGHT FALLS WILL LEAD TO A GRADUAL DECLINE IN TEMPERATURES TO JUST
5 TO 10 DEGREES ABOVE NORMAL BY FRIDAY.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AT KCLT...CONTINUED SHRA WILL AFFECT THE AIRFIELD THROUGH THE AFTN
AND EVENING HOURS...BUT WITH TSRA MUCH MORE DIFFICULT TO TIME.
ANTICIPATE MAINLY MVFR CIGS ON S TO SW MIXING WITH OCCASIONAL
GUSTS...AND THEN A RETURN TO IFR THEN LIFR CIGS OVERNIGHT AS THE
MIXING AND RAINFALL LESSEN. PERISTENT SRLY FLOW SHOULD KEEP VSBY
FROM CRASHING DESPITE THE VERY MOIST GROUND. MVFR CIGS/VSBY WILL BE
VERY SLOW TO IMPROVE THROUGH LATE MORNING FRIDAY.
ELSEWHERE...EXPECT CONTINUED FAIRLY WIDESPREAD SHRA ACROSS THE MTN
AND FOOTHILL TAF SITES...BUT WITH CONVECTIVE CHANCES APPEARING TO BE
A BIT LESS. THE LATEST HRRR DOES BRING SOME CONVECTION BACK TONIGHT
WHICH WILL NEED TO BE MONITORED FOR TEMPO TSRA AFTER 05Z.
OTHERWISE...MVFR TO VFR CIGS EARLY WILL RETURN TO IFR THEN LIFR
OVERNIGHT IN THE MOIST SRLY FLOW. UPSLOPE SHRA ARE LIKELY AT TIMES
THROUGH 18Z FRIDAY.
OUTLOOK...DEEP LAYER MOISTURE AHEAD OF A STALLED FRONT WILL PERSIST
OVER AT LEAST THE MOUNTAINS THROUGH LATE FRIDAY...BEFORE SOME MINOR
DRYING OCCURS OVER THE WEEKEND. SRLY UPSLOPE FLOW WILL PERSIST OVER
THE WEEKEND...HOWEVER...WITH SOME RESTRICTIONS ONCE AGAIN LIKELY.
ANOTHER WET SYSTEM WILL APPROACH FROM THE WEST EARLY NEXT WEEK.
CONFIDENCE TABLE...
20-02Z 02-08Z 08-14Z 14-18Z
KCLT HIGH 90% HIGH 87% HIGH 83% HIGH 90%
KGSP HIGH 82% MED 75% HIGH 90% HIGH 90%
KAVL HIGH 85% MED 72% HIGH 83% HIGH 90%
KHKY HIGH 92% MED 64% HIGH 87% HIGH 90%
KGMU HIGH 89% MED 75% HIGH 83% HIGH 90%
KAND HIGH 94% MED 78% HIGH 88% HIGH 90%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.HYDROLOGY...
ONGOING AND DEVELOPING HYDRO ISSUES WILL BE EXACERBATED BY
ADDITIONAL MODERATE TO HEAVY RAINFALL IN THE EXTREME SOUTHERN
APPALCHIANS TONIGHT INTO FRIDAY. ADDITIONAL QPF OF 1.5 TO 2.5 INCHES
ARE POSSIBLE IN THE SRN ESCARPMENT AREAS...WITH 1 TO 2 INCHES
POSSIBLE ACROSS THE FOOTHILLS...AND AMOUNTS FALLING OFF QUICKLY
FARTHER EAST INTO THE PIEDMONT. LOCALLY HEAVY RAINFALL COULD
REDEVELOP JUST ABOUT ANYWHERE WITH SCATTERED CONVECTION...BUT THE NC
MOUNTAINS...GA MTNS...AND IMMEDIATELY ADJACENT FOOTHILLS SHOULD HAVE
THE LONGEST DURATION HYDRO ISSUES THROUGH FRIDAY. THE FLASH FLOOD
WATCH WILL BE EXTENDED IN THESE AREAS.
&&
.CLIMATE...
DAILY MAXIMUM TEMPERATURE RECORDS FOR FRIDAY DECEMBER 25...
AVL 67 1955...1944...1904
CLT 77 1955
GSP 78 1955
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR FRIDAY DEC 25...
AVL 55 1982
CLT 62 1932
GSP 56 1964
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR GAZ010-017-018-
026-028.
FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR GAZ029.
NC...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR NCZ033-035-
048>053-058-059-062>065-501>510.
FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR NCZ036-037-
056-057-068>072-082.
SC...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR SCZ001>007-010.
FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR SCZ008-009-
011>014-019.
&&
$$
SYNOPSIS...HG
NEAR TERM...HG
SHORT TERM...HG
LONG TERM...LEV
AVIATION...HG
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
227 PM EST THU DEC 24 2015
.SYNOPSIS...
DEEP MOISTURE WILL FOCUS MAINLY ON THE SOUTHERN APPALACHIANS TONIGHT
BEFORE GRADUALLY RETREATING TO THE NORTH AND WEST FRIDAY THROUGH THE
WEEKEND. HIGH PRESSURE WILL BUILD IN FROM THE SOUTHEAST OVER THE
WEEKEND...BUT WITH CONTINUED LOW LEVEL MOISTURE IN PLACE. A STRONG
LOW PRESSURE SYSTEM MAY APPROACH FROM THE WEST EARLY NEXT WEEK TO
BRING ANOTHER ROUND OF HEAVY RAINFALL TO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1255 PM EST...PRECIPITATION RATES ARE EXPERIENCING A RELATIVE
LULL EARLY THIS AFTERNOON AS THE BETTER RATES ARE SHIFTING OFF THE
NE...AND ALSO GATHER TO THE S ACROSS CENTRAL GA. THE LATEST HRRR
FEATURES THE LULL LASTING THROUGH THE EVENING...WITH FAIRLY HIGH
POPS FOR CONTINUED SRLY UPSLOPE...BUT WITH LOWER RATES AND WEAK
CONVECTION. ALSO...THE BEST LOW LEVEL JET HAS WEAKENED AND VEERED SO
THE TSTM THREAT SHOULD BE FAIRLY MINIMAL FOR ALL BUT LOCALLY HEAVY
RAINFALL AND ISOLD WIND GUSTS.
OTHERWISE...DEEP LAYER SW FLOW WILL PERSIST THROUGH THE PERIOD AS
WEAK H5 VORT LOBES MOVE THROUGH ALOFT. THE BEST MOISTURE WILL FOCUS
PRIMARILY ON THE SRN APPALACHIANS TONIGHT THROUGH FRIDAY AS HEIGHTS
SLOWLY BUILD ACROSS THE SE. THE LOW LEVEL FLOW WILL VEER FARTHER SW
AND FOCUS THE UPSLOPE FORCING AROUND THE FAR SRN AND SW MTNS. THE
FLASH FLOOD WATCH WILL LIKELY BE EXTENDED FOR AT LEAST THE
MOUNTAINS. INSTABILITY FOR SCT CONVECTION WILL REMAIN BEST IN
PIEDMONT SECTIONS ON FRIDAY...BUT WITH COVERAGE PROBABLY TOO LOW TO
WARRANT A LONGER DURATION WATCH EXPANSIION THERE. MINS WILL BE 30
DEGREES ABOVE CLIMO TONIGHT WITH MAXES 20 DEGREES ABOVE CLIMO FRIDAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AT 230 AM THURSDAY...ON FRIDAY MORNING AN UPPER RIDGE WILL BE
CENTERED OVER THE WESTERN ATLANTIC...WHILE AN UPPER TROUGH WILL BE
OVER THE ROCKIES. AN UPPER LOW CLOSES OFF IN THE SOUTHWEST USA...
WHILE NORTHERN STREAM PROGRESSES AND GOES OUT OF PHASE. BY SUNDAY
MORNING THE UPPER LOW IS OVER NORTH CENTRAL MX...WHILE THE ATLANTIC
UPPER RIDGE RETROGRESSES SLIGHTLY OVER THE SOUTHEAST USA. THIS PATTERN
RESULTS IN THE BULK OF UPPER LEVEL ENERGY BEING DIRECTED WELL TO OUR
WEST AND NORTH.
AT THE SURFACE...ON FRIDAY A NEARLY STATIONARY FRONT WILL BE OVER
THE SOUTHERN APPALACHIANS...WITH SOUTHWESTERLY GULF INFLOW AHEAD OF
THE BOUNDARY IMPACTING OUR AREA. THE FRONT MOVES NORTH TO THE OH AND
POTOMAC RIVER VALLEYS ON SATURDAY...WHILE GULF INFLOW CONTINUES. A
COLD FRONT WILL MOVE INTO THE OH AND MID MS RIVER VALLEYS BY SUNDAY
MORNING...WITH GULF INFLOW PERSISTING.
THE SOUTHWESTERLY ASPECT OF GULF INFLOW WILL HAMPER ISENTROPIC
UPGLIDE AND UPSLOPE FLOW...LIMITING PRECIPITATION PRODUCTION. BOTH
INSTABILITY AND SHEAR WILL BE PRESENT ON FRIDAY...AND THERE A
MARGINAL RISK FOR SEVERE WEATHER...MAINLY DURING THE DAY. WHILE
INSTABILITY IS PRESENT ON SATURDAY...SHEAR WILL BE MORE LIMITED.
TEMPERATURES WILL RUN WELL ABOVE NORMAL UNDER THE INFLUENCE OF THE
ATLANTIC RIDGE...WITH MINIMUMS EVEN MORE EXTREME DUE TO ROBUST
MOISTURE.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AT 230 AM THURSDAY...ON SUNDAY MORNING AN ATLANTIC UPPER RIDGE WILL
EXTEND WEST TO THE SOUTHEAST USA...WHILE A CLOSED UPPER LOW WILL BE
OVER NORTH CENTRAL MX. THE TROUGH MOVES OVER TX ON MONDAY...AND
APPROACHES THE GREAT LAKES ON TUESDAY...WHILE THE RIDGE TO THE EAST
GRADUALLY BREAKS DOWN. MEANWHILE...ANOTHER AN UPPER LOW MOVES INTO
THE BASE TO THE WEST TROUGH. THIS LOW NEVER DEEPENS LIKE THE
PREVIOUS ONE...AND FILLS AS IT CROSSES THE PLAINS ON WEDNESDAY.
AT THE SURFACE...THE COLD FRONT OVER THE OH RIVER VALLEY SUNDAY
MORNING IS EXPECTED TO PUSH SOUTH O THE CAROLINAS BY MONDAY AS HIGH
PRESSURE OVER CANADA EXTENDS SOUTH ALONG THE EAST COAST. MEANWHILE
GULF INFLOW AHEAD OF A COLD FRONT WILL IMPACT THE GULF STATES. THE
CAROLINA FRONT MOVES SLOWLY NORTH ON TUESDAY...WHILE THE COLD FRONT
TO OUR WEST CROSSES THE GULF STATES...AND GULF INFLOW INCREASES INTO
THE SOUTHERN APPALACHIANS. THE COLD FRONT CROSSES THE MOUNTAINS AND
STALLS OVER THE PIEDMONT ON WEDNESDAY...WHILE GULF MOISTURE
CONTINUES TO SPREAD NE ALONG AND OVER THE BOUNDARY.
ISENTROPIC UPGLIDE AND SOUTHERLY UPSLOPE FLOW WILL BE MAINLY
LIMITED TO MONDAY AHEAD TO THE APPROACHING COLD FRONT. OTHERWISE...
LOW LEVEL FLOW GENERALLY BE FROM THE SE...WITH LITTLE UPGLIDE UP
UPSLOPE COMPONENT. THIS WILL LIMIT PRECIPITATION PRODUCTION...
DESPITE THE PROLONGED NATURE OF MOIST INFLOW. TEMPERATURES WILL
REMAIN ABOVE NORMAL...BUT WITH A DOWNWARD TRENDS AS HEIGHT FALL
ALOFT WITH THE BREAKDOWN OF THE UPPER RIDGE.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AT KCLT...CONTINUED SHRA WILL AFFECT THE AIRFIELD THROUGH THE AFTN
AND EVENING HOURS...BUT WITH TSRA MUCH MORE DIFFICULT TO TIME.
ANTICIPATE MAINLY MVFR CIGS ON S TO SW MIXING WITH OCCASIONAL
GUSTS...AND THEN A RETURN TO IFR THEN LIFR CIGS OVERNIGHT AS THE
MIXING AND RAINFALL LESSEN. PERISTENT SRLY FLOW SHOULD KEEP VSBY
FROM CRASHING DESPITE THE VERY MOIST GROUND. MVFR CIGS/VSBY WILL BE
VERY SLOW TO IMPROVE THROUGH LATE MORNING FRIDAY.
ELSEWHERE...EXPECT CONTINUED FAIRLY WIDESPREAD SHRA ACROSS THE MTN
AND FOOTHILL TAF SITES...BUT WITH CONVECTIVE CHANCES APPEARING TO BE
A BIT LESS. THE LATEST HRRR DOES BRING SOME CONVECTION BACK TONIGHT
WHICH WILL NEED TO BE MONITORED FOR TEMPO TSRA AFTER 05Z.
OTHERWISE...MVFR TO VFR CIGS EARLY WILL RETURN TO IFR THEN LIFR
OVERNIGHT IN THE MOIST SRLY FLOW. UPSLOPE SHRA ARE LIKELY AT TIMES
THROUGH 18Z FRIDAY.
OUTLOOK...DEEP LAYER MOISTURE AHEAD OF A STALLED FRONT WILL PERSIST
OVER AT LEAST THE MOUNTAINS THROUGH LATE FRIDAY...BEFORE SOME MINOR
DRYING OCCURS OVER THE WEEKEND. SRLY UPSLOPE FLOW WILL PERSIST OVER
THE WEEKEND...HOWEVER...WITH SOME RESTRICTIONS ONCE AGAIN LIKELY.
ANOTHER WET SYSTEM WILL APPROACH FROM THE WEST EARLY NEXT WEEK.
CONFIDENCE TABLE...
19-01Z 01-07Z 07-13Z 13-18Z
KCLT HIGH 92% HIGH 85% HIGH 83% HIGH 83%
KGSP MED 79% MED 76% HIGH 88% HIGH 81%
KAVL MED 72% MED 76% HIGH 86% HIGH 80%
KHKY HIGH 93% MED 62% HIGH 81% HIGH 85%
KGMU HIGH 87% MED 74% MED 77% HIGH 85%
KAND HIGH 86% MED 68% HIGH 84% HIGH 83%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.HYDROLOGY...
ONGOING AND DEVELOPING HYDRO ISSUES WILL BE EXACERBATED BY
ADDITIONAL MODERATE TO HEAVY RAINFALL IN THE EXTREME SOUTHERN
APPALCHIANS TONIGHT INTO FRIDAY. ADDITIONAL QPF OF 1.5 TO 2 INCHES
IS LIKELY IN THE SRN ESCARPMENT AREAS...WITH AMOUNTS FALLING OFF
QUICKLY FARTHER EAST INTO THE PIEDMONT. LOCALLY HEAVY RAINFALL COULD
REDEVELOP JUST ABOUT ANYWHERE WITH SCATTERED CONVECTION...BUT THE NC
MOUNTAINS...GA MTNS...AND IMMEDIATELY ADJACENT FOOTHILLS SHOULD HAVE
THE LONGEST DURATION HYDRO ISSUES THROUGH FRIDAY.
&&
.CLIMATE...
DAILY MAXIMUM TEMPERATURE RECORDS FOR THURSDAY DECEMBER 24...
AVL 72 1955
CLT 71 1982...1931
GSP 71 1964
DAILY MAXIMUM TEMPERATURE RECORDS FOR FRIDAY DECEMBER 25...
AVL 67 1955...1944...1904
CLT 77 1955
GSP 78 1955
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR WEDNESDAY DEC 23...
AVL 59 1990
CLT 63 1990
GSP 61 1990
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR THURSDAY DEC 24...
AVL 54 1932
CLT 56 1891
GSP 55 1931
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR FRIDAY DEC 25...
AVL 55 1982
CLT 62 1932
GSP 56 1964
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR GAZ010-017-
018-026-028-029.
NC...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR NCZ033-
035>037-048>053-056>059-062>065-068>072-082-501>510.
SC...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR SCZ001>014-
019.
&&
$$
SYNOPSIS...JAT
NEAR TERM...HG
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...HG
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
115 PM EST THU DEC 24 2015
.SYNOPSIS...
UNSETTLED WEATHER AND ABOVE NORMAL TEMPERATURES WILL CONTINUE
THROUGH EARLY NEXT WEEK AHEAD OF A COLD FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM EST...THE LOW LEVEL SOUTHWESTERLY JET MAXIMIZED OVER
THE FORECAST AREA EARLY THIS MORNING...BUT NOW CONTINUES TO WEAKEN
SLIGHTLY AND VEER. THIS...COMBINED WITH THE SOMEWHAT LIMITED
INSTABILITY DUE TO THE WIDESPREAD CLOUDS...PRECIP...AND WARM
PROFILES...APPEARS TO BE LIMITING THE STRENGTH OF THE CONVECTION
THUS FAR. HOWEVER...CONTINUED S TO SW UPSLOPE FLOW WILL PERMIT THE
FOCUS OF ONGOING AND NEW HYDRO CONCERNS TO FOCUS MORE SOLIDLY ON THE
MTNS AND THE IMMEDIATELY ADJACENT FOOTHILLS GOING FORWARD. THE FLASH
FLOD WATCH WILL CONTINUE THROUGHOUT...BUT THE LANDSLIDE WORDING WILL
BE BEEFED UP FOR LOCATIONS IN AND NEAR THE HIGHER TERRAIN THE REST
OF TODAY THROUGH TONIGHT.
OTHERWISE...HIGHS TODAY WILL BE 20 TO 25 DEGREES ABOVE NORMAL AND
WILL THREATEN RECORDS. LOWS TONIGHT WILL BE 30 TO 35 DEGREES ABOVE
NORMAL AND WILL THREATEN RECORDS FOR HIGHEST MINIMUM TEMPERATURES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AT 230 AM THURSDAY...ON FRIDAY MORNING AN UPPER RIDGE WILL BE
CENTERED OVER THE WESTERN ATLANTIC...WHILE AN UPPER TROUGH WILL BE
OVER THE ROCKIES. AN UPPER LOW CLOSES OFF IN THE SOUTHWEST USA...
WHILE NORTHERN STREAM PROGRESSES AND GOES OUT OF PHASE. BY SUNDAY
MORNING THE UPPER LOW IS OVER NORTH CENTRAL MX...WHILE THE ATLANTIC
UPPER RIDGE RETROGRESSES SLIGHTLY OVER THE SOUTHEAST USA. THIS PATTERN
RESULTS IN THE BULK OF UPPER LEVEL ENERGY BEING DIRECTED WELL TO OUR
WEST AND NORTH.
AT THE SURFACE...ON FRIDAY A NEARLY STATIONARY FRONT WILL BE OVER
THE SOUTHERN APPALACHIANS...WITH SOUTHWESTERLY GULF INFLOW AHEAD OF
THE BOUNDARY IMPACTING OUR AREA. THE FRONT MOVES NORTH TO THE OH AND
POTOMAC RIVER VALLEYS ON SATURDAY...WHILE GULF INFLOW CONTINUES. A
COLD FRONT WILL MOVE INTO THE OH AND MID MS RIVER VALLEYS BY SUNDAY
MORNING...WITH GULF INFLOW PERSISTING.
THE SOUTHWESTERLY ASPECT OF GULF INFLOW WILL HAMPER ISENTROPIC
UPGLIDE AND UPSLOPE FLOW...LIMITING PRECIPITATION PRODUCTION. BOTH
INSTABILITY AND SHEAR WILL BE PRESENT ON FRIDAY...AND THERE A
MARGINAL RISK FOR SEVERE WEATHER...MAINLY DURING THE DAY. WHILE
INSTABILITY IS PRESENT ON SATURDAY...SHEAR WILL BE MORE LIMITED.
TEMPERATURES WILL RUN WELL ABOVE NORMAL UNDER THE INFLUENCE OF THE
ATLANTIC RIDGE...WITH MINIMUMS EVEN MORE EXTREME DUE TO ROBUST
MOISTURE.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AT 230 AM THURSDAY...ON SUNDAY MORNING AN ATLANTIC UPPER RIDGE WILL
EXTEND WEST TO THE SOUTHEAST USA...WHILE A CLOSED UPPER LOW WILL BE
OVER NORTH CENTRAL MX. THE TROUGH MOVES OVER TX ON MONDAY...AND
APPROACHES THE GREAT LAKES ON TUESDAY...WHILE THE RIDGE TO THE EAST
GRADUALLY BREAKS DOWN. MEANWHILE...ANOTHER AN UPPER LOW MOVES INTO
THE BASE TO THE WEST TROUGH. THIS LOW NEVER DEEPENS LIKE THE
PREVIOUS ONE...AND FILLS AS IT CROSSES THE PLAINS ON WEDNESDAY.
AT THE SURFACE...THE COLD FRONT OVER THE OH RIVER VALLEY SUNDAY
MORNING IS EXPECTED TO PUSH SOUTH O THE CAROLINAS BY MONDAY AS HIGH
PRESSURE OVER CANADA EXTENDS SOUTH ALONG THE EAST COAST. MEANWHILE
GULF INFLOW AHEAD OF A COLD FRONT WILL IMPACT THE GULF STATES. THE
CAROLINA FRONT MOVES SLOWLY NORTH ON TUESDAY...WHILE THE COLD FRONT
TO OUR WEST CROSSES THE GULF STATES...AND GULF INFLOW INCREASES INTO
THE SOUTHERN APPALACHIANS. THE COLD FRONT CROSSES THE MOUNTAINS AND
STALLS OVER THE PIEDMONT ON WEDNESDAY...WHILE GULF MOISTURE
CONTINUES TO SPREAD NE ALONG AND OVER THE BOUNDARY.
ISENTROPIC UPGLIDE AND SOUTHERLY UPSLOPE FLOW WILL BE MAINLY
LIMITED TO MONDAY AHEAD TO THE APPROACHING COLD FRONT. OTHERWISE...
LOW LEVEL FLOW GENERALLY BE FROM THE SE...WITH LITTLE UPGLIDE UP
UPSLOPE COMPONENT. THIS WILL LIMIT PRECIPITATION PRODUCTION...
DESPITE THE PROLONGED NATURE OF MOIST INFLOW. TEMPERATURES WILL
REMAIN ABOVE NORMAL...BUT WITH A DOWNWARD TRENDS AS HEIGHT FALL
ALOFT WITH THE BREAKDOWN OF THE UPPER RIDGE.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT...CONTINUED SHRA WILL AFFECT THE AIRFIELD THROUGH THE AFTN
AND EVENING HOURS...BUT WITH TSRA MUCH MORE DIFFICULT TO TIME.
ANTICIPATE MAINLY MVFR CIGS ON S TO SW MIXING WITH OCCASIONAL
GUSTS...AND THEN A RETURN TO IFR THEN LIFR CIGS OVERNIGHT AS THE
MIXING AND RAINFALL LESSEN. PERISTENT SRLY FLOW SHOULD KEEP VSBY
FROM CRASHING DESPITE THE VERY MOIST GROUND. MVFR CIGS/VSBY WILL BE
VERY SLOW TO IMPROVE THROUGH LATE MORNING FRIDAY.
ELSEWHERE...EXPECT CONTINUED FAIRLY WIDESPREAD SHRA ACROSS THE MTN
AND FOOTHILL TAF SITES...BUT WITH CONVECTIVE CHANCES APPEARING TO BE
A BIT LESS. THE LATEST HRRR DOES BRING SOME CONVECTION BACK TONIGHT
WHICH WILL NEED TO BE MONITORED FOR TEMPO TSRA AFTER 05Z.
OTHERWISE...MVFR TO VFR CIGS EARLY WILL RETURN TO IFR THEN LIFR
OVERNIGHT IN THE MOIST SRLY FLOW. UPSLOPE SHRA ARE LIKELY AT TIMES
THROUGH 18Z FRIDAY.
OUTLOOK...DEEP LAYER MOISTURE AHEAD OF A STALLED FRONT WILL PERSIST
OVER AT LEAST THE MOUNTAINS THROUGH LATE FRIDAY...BEFORE SOME MINOR
DRYING OCCURS OVER THE WEEKEND. SRLY UPSLOPE FLOW WILL PERSIST OVER
THE WEEKEND...HOWEVER...WITH SOME RESTRICTIONS ONCE AGAIN LIKELY.
ANOTHER WET SYSTEM WILL APPROACH FROM THE WEST EARLY NEXT WEEK.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 94% HIGH 80% HIGH 89% HIGH 84%
KGSP MED 78% HIGH 82% HIGH 90% HIGH 86%
KAVL HIGH 83% HIGH 81% HIGH 88% HIGH 83%
KHKY HIGH 100% MED 64% HIGH 81% HIGH 86%
KGMU HIGH 88% MED 78% MED 78% HIGH 86%
KAND HIGH 90% MED 79% HIGH 87% HIGH 84%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.HYDROLOGY...
ONGOING AND DEVELOPING HYDRO ISSUES WILL BE EXACERBATED BY
ADDITIONAL MODERATE TO HEAVY RAINFALL IN THE EXTREME SOUTHERN
APPALCHIANS TONIGHT INTO FRIDAY. ADDITIONAL QPF OF 1.5 TO 2 INCHES
IS LIKELY IN THE SRN ESCARPMENT AREAS...WITH AMOUNTS FALLING OFF
QUICKLY FARTHER EAST INTO THE PIEDMONT. LOCALLY HEAVY RAINFALL COULD
REDEVELOP JUST ABOUT ANYWHERE WITH SCATTERED CONVECTION...BUT THE NC
MOUNTAINS...GA MTNS...AND IMMEDIATELY ADJACENT FOOTHILLS SHOULD HAVE
THE LONGEST DURATION HYDRO ISSUES THROUGH FRIDAY.
&&
.CLIMATE...
DAILY MAXIMUM TEMPERATURE RECORDS FOR THURSDAY DECEMBER 24...
AVL 72 1955
CLT 71 1982...1931
GSP 71 1964
DAILY MAXIMUM TEMPERATURE RECORDS FOR FRIDAY DECEMBER 25...
AVL 67 1955...1944...1904
CLT 77 1955
GSP 78 1955
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR WEDNESDAY DEC 23...
AVL 59 1990
CLT 63 1990
GSP 61 1990
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR THURSDAY DEC 24...
AVL 54 1932
CLT 56 1891
GSP 55 1931
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR FRIDAY DEC 25...
AVL 55 1982
CLT 62 1932
GSP 56 1964
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR GAZ010-017-
018-026-028-029.
NC...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR NCZ033-
035>037-048>053-056>059-062>065-068>072-082-501>510.
SC...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR SCZ001>014-
019.
&&
$$
SYNOPSIS...JAT
NEAR TERM...HG
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...HG
HYDROLOGY...HG
CLIMATE...JAT
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
840 PM CST FRI DEC 25 2015
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...
WARM FRONT CONTINUES TO MOVE SLOWLY NORTHWARD ACROSS MIDDLE
TENNESSEE, WITH NASHVILLE STILL NORTH OF THE BOUNDARY. THE ONLY
PRECIPITATION SHOWING UP ON RADAR IS LOCATED ALONG THE PLATEAU,
ALTHOUGH THE HRRR SHOWS SOME RE-DEVELOPMENT AFTER MIDNIGHT WITH
THE PASSAGE OF THE WARM FRONT. WAS HOPING THE WARMER AIR MIGHT
LOWER RH VALUES AND REDUCE OUR CHANCE OF DENSE FOG, BUT DEW POINTS
ARE COMING RIGHT UP WITH THE TEMPS, SO DEW POINT SPREADS EVEN IN
THE WARM SECTOR ARE RUNNING ZERO OR CLOSE TO ZERO. HAVE ALREADY
INCLUDED PATCHY DENSE FOG IN THE GRIDS, AND WE WILL MONITOR IN
CASE AN ADVISORY IS NEEDED. HAVE MADE ADJUSTMENTS TO LOW TEMPS TO
COME MORE IN LINE WITH CURRENT OBS, AS TEMPS OVERNIGHT WILL LIKELY
INCREASE SLIGHTLY AS THE WARM FRONT LIFTS FARTHER NORTHWARD.
&&
.AVIATION...
00Z TAF DISCUSSION.
FLYING CONDITIONS WILL NOT BE FAVORABLE FOR ALL THREE TERMINALS
FOR THE TAF PERIOD. A WARM FRONT IS DRAPED ACROSS MIDDLE TN WITH
CSV BEING ON THE SOUTHERN SIDE OF THE BOUNDARY AND CKV AND BNA
BEING ON THE NORTHERN SIDE OF THE BOUNDARY. BNA AND CKV WILL
CONTINUE TO HAVE ISSUES WITH BR AND FG OVERNIGHT ALONG WITH LIFR
CIGS. CIGS SHOULD ONLY DIP TO IFR AT CSV. THE BIG QUESTION IS
PRECIP AS THE WARM FRONT MOVES NORTH. HRRR IS NOT PRODUCING MUCH
IN THE WAY OF TS AND RA UNTIL THE 10Z TIME FRAME FOR BNA AND CKV.
I AM NOT CONFIDENT ENOUGH WITH THE PRECIP CHANCES TO INCLUDE A
PREVAILING LINE. WILL HAVE TO MONITOR OVERNIGHT. WINDS WILL VEER
AND INCREASE FOR CKV AND BNA AS THE WARM FRONT MOVES NORTH.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH UNTIL 6 AM CST SATURDAY FOR BEDFORD-CANNON-CLAY-
COFFEE-CUMBERLAND-DAVIDSON-DE KALB-FENTRESS-GILES-GRUNDY-HICKMAN-
JACKSON-LAWRENCE-LEWIS-MACON-MARSHALL-MAURY-OVERTON-PERRY-
PICKETT-PUTNAM-RUTHERFORD-SMITH-TROUSDALE-VAN BUREN-WARREN-WAYNE-
WHITE-WILLIAMSON-WILSON.
&&
$$
SHORT TERM/AVIATION........10/REAGAN
LONG TERM..................08
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
549 PM CST FRI DEC 25 2015
.UPDATE...
FOR 00Z AVIATION DISCUSSION.
&&
.DISCUSSION...
A VERY ACTIVE MORNING WEATHER WISE HAS TURNED INTO A MUCH QUIETER
AFTERNOON WITH THE HEAVIEST PRECIPITATION SHIFTING SOUTH OF THE
STATE LINE INTO ALABAMA. RAINFALL AMOUNTS HAVE GENERALLY BEEN
AROUND 1 TO 2 INCHES SO FAR...WITH A FEW LOCATIONS IN SOUTHERN AND
EASTERN MIDDLE TENNESSEE IN THE 2 TO 4 INCH RANGE. NOT TOO MANY
SIGNIFICANT FLOODING ISSUES BEING REPORTED AT THIS TIME IN MIDDLE
TENNESSEE ESPECIALLY COMPARED TO OUR NEIGHBORS TO THE SOUTH.
THE MAIN QUESTION FOR TONIGHT WILL BE HOW MUCH OF THIS
PRECIPITATION WILL STAY TOGETHER ONCE THE WARM FRONT BEGINS TO
MOVE NORTH. WITH PW VALUES NEAR RECORD LEVELS FOR THIS TIME OF
YEAR AND A NICE LOW LEVEL JET SHAPING UP BEHIND THE WARM
FRONT...ONE WOULD THINK THAT A HALF INCH TO MAYBE 1-2 INCHES OF
RAINFALL WILL BE POSSIBLE AGAIN TONIGHT ESPECIALLY ACROSS
LOCATIONS ALONG AND SOUTH OF INTERSTATE 40. SHORT RANGE MODELS ARE
DEFINITELY NOT IN GOOD AGREEMENT ABOUT SHOWER AND THUNDERSTORM
DEVELOPMENT THIS EVENING AND OVERNIGHT...SO DECIDED TO HOLD ONTO
THE FLOOD WATCH SINCE IT WILL NOT TAKE MUCH TO CAUSE FLOODING
ISSUES ESPECIALLY AT NIGHT.
FOR THE WEEKEND...WITH MIDDLE TENNESSEE FIRMLY ENTRENCHED IN THE
WARM SECTOR...THERE WON`T BE TOO MANY WAYS TO NOTICE IT`S DECEMBER
EXCEPT FOR THE AFTER CHRISTMAS SALES. WHY? WELL HIGH TEMPERATURES
BOTH SATURDAY AND SUNDAY WILL LIKELY BREAK RECORDS...WITH
TEMPERATURES EXPECTED TO BE 25-30 DEGREES ABOVE NORMAL! THAT`S
RIGHT. THAT ISN`T A MISTYPE. A GOOD 25-30 DEGREES ABOVE SEASONAL
NORMALS. MY GUESS IS THAT WE WILL LIKELY PAY FOR THIS NICE WEATHER
IN THE MIDDLE OF FEBRUARY SOMETIME. ONLY TIME WILL TELL. SO EVEN
THOUGH THE KIDS MIGHT BE DISAPPOINTED TODAY FOR NOT BEING ABLE TO
PLAY WITH THEIR NEW TOYS OUTSIDE...THIS WEEKEND IS SHAPING UP TO
BE FAIRLY NICE AS THE BULK OF THE PRECIPITATION STAYS WEST AND
NORTHWEST OF THE FORECAST AREA WITH ONLY SMALL CHANCES FOR SHOWERS
AND THUNDERSTORMS BOTH DAYS.
FINALLY THE MAIN LOW PRESSURE SYSTEM AND COLD FRONT APPROACH
MIDDLE TENNESSEE SUNDAY NIGHT INTO MONDAY. CURRENTLY...THE SYSTEM
APPEARS TO BECOME OCCLUDED ONCE IT FINALLY REACHES THE AREA. AT
THIS TIME...IT LOOKS LIKE THE BEST SEVERE WEATHER CHANCES WILL
REMAIN WEST AND SOUTHWEST OF THE AREA...HOWEVER THIS IS SOMETHING
TO CONTINUE TO WATCH FOR AS MODEL SOLUTIONS COME INTO BETTER
AGREEMENT. RAIN WILL FINALLY END MONDAY NIGHT GIVING WAY TO MORE
SEASONABLE TEMPERATURES/COOLER AND DRIER AIR BY TUESDAY. THIS
LIKELY WON`T LAST LONG AS SOUTHERLY FLOW REDEVELOPS AGAIN
BRINGING THE NEXT CHANCE FOR RAIN JUST AFTER MID WEEK.
&&
.AVIATION...
00Z TAF DISCUSSION.
FLYING CONDITIONS WILL NOT BE FAVORABLE FOR ALL THREE TERMINALS
FOR THE TAF PERIOD. A WARM FRONT IS DRAPED ACROSS MIDDLE TN WITH
CSV BEING ON THE SOUTHERN SIDE OF THE BOUNDARY AND CKV AND BNA
BEING ON THE NORTHERN SIDE OF THE BOUNDARY. BNA AND CKV WILL
CONTINUE TO HAVE ISSUES WITH BR AND FG OVERNIGHT ALONG WITH LIFR
CIGS. CIGS SHOULD ONLY DIP TO IFR AT CSV. THE BIG QUESTION IS
PRECIP AS THE WARM FRONT MOVES NORTH. HRRR IS NOT PRODUCING MUCH
IN THE WAY OF TS AND RA UNTIL THE 10Z TIME FRAME FOR BNA AND CKV.
I AM NOT CONFIDENT ENOUGH WITH THE PRECIP CHANCES TO INCLUDE A
PREVAILING LINE. WILL HAVE TO MONITOR OVERNIGHT. WINDS WILL VEER
AND INCREASE FOR CKV AND BNA AS THE WARM FRONT MOVES NORTH.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH LATE TONIGHT FOR BEDFORD-CANNON-CLAY-COFFEE-
CUMBERLAND-DAVIDSON-DE KALB-FENTRESS-GILES-GRUNDY-HICKMAN-
JACKSON-LAWRENCE-LEWIS-MACON-MARSHALL-MAURY-OVERTON-PERRY-
PICKETT-PUTNAM-RUTHERFORD-SMITH-TROUSDALE-VAN BUREN-WARREN-WAYNE-
WHITE-WILLIAMSON-WILSON.
&&
$$
SHORT TERM/AVIATION........10/REAGAN
LONG TERM..................HURLEY
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1139 AM CST THU DEC 24 2015
.AVIATION...
A COLD FRONT HAS PASSED THROUGH ALL THE TAF SITES WITH NORTH-
NORTHEAST WINDS AROUND 10 TO 15 KTS. THE WINDS WILL SLOWLY COME
AROUND TO THE EAST AND DIMINISH BY EVENING. SOME MID TO UPPER
LEVEL CLOUDINESS IS EXPECTED BUT VFR CONDITIONS WILL CONTINUE FOR
THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 531 AM CST THU DEC 24 2015/
AVIATION...
A WEAK COLD FRONT PASSING THROUGH THE CENTRAL PANHANDLE WILL PASS
TAF SITES BY MID MORNING WITH MODEST NORTH TO NORTHEAST POST
FRONTAL BREEZES. WINDS MAY BRIEFLY EXCEED 12 KNOTS...ESPECIALLY AT
KCDS. WINDS WILL TURN TO SOUTHEAST LATER TODAY AT BOTH KLBB AND
KPVW. OTHERWISE VFR WITH AN INCREASE IN MID LEVEL MOISTURE
EXPECTED MAINLY OVER KPVW LATER TODAY. LIGHT SHOWER CHANCES SHOULD
REMAIN NORTHWEST OF KPVW. RMCQUEEN
PREV DISCUSSION... /ISSUED 456 AM CST THU DEC 24 2015/
SHORT TERM...
A WEAK COLD FRONT EXTENDING OUT OF THE DISTURBANCE IN EASTERN SOUTH
DAKOTA AND NEBRASKA...AND CROSSING THE PANHANDLE AT THIS TIME...WILL
SPREAD SOUTH ACROSS THE AREA SHORTLY AFTER DAYBREAK. NORTHERLY
BREEZES WILL BE STRONGEST OVER THE NORTHERN ROLLING PLAINS...NEAR 15
MPH LATE THIS MORNING...TRENDING LIGHTER LATER TODAY AND TURNING
SOUTHEAST ON THE CAPROCK. DRIER AIR ALSO WILL SPREAD SOUTH BEHIND
THE FRONT. ALOFT...A VERY ENERGETIC WESTERLY FLOW WILL BACK TO THE
SOUTHWEST AS POTENT STORM ENERGY CROSSES THE NORTHWEST COAST AND
STARTS DEEPENING OVER THE NORTHERN GREAT BASIN TONIGHT. BANDS OF MID
AND UPPER LEVEL MOISTURE WILL CONTINUE OVER OUR AREA TODAY AND
TONIGHT. HRRR SOLUTION AT LEAST TRIES TO BREAK OUT SPRITZY LIGHT
SHOWERS NEAR NORTHWESTERN ZONES LATER TODAY...CHANCES WILL BE SMALL
HOWEVER OWING TO THE DRIER LOWER LEVELS BEHIND THE FRONT MENTIONED
ABOVE. SLIGHTLY COOLER WITH THE FRONT TODAY AND SOME THICKENING OF
MID LEVEL CLOUDS EXPECTED DURING THE DAY...BUT STILL ABOVE NORMAL.
SLIGHTLY COOLER TONIGHT AS WELL YET ALSO STILL ABOVE NORMAL.
RMCQUEEN
LONG TERM...
LIKELIHOOD OF BLIZZARD CONDITIONS AND HEAVY SNOW CONTINUING FOR
LATE WEEKEND...
AFTER ONE MORE ABNORMALLY WARM DECEMBER DAY TO CELEBRATE
CHRISTMAS...INCREASING SOUTHWEST FLOW ALOFT BRINGING THIS WARMUP
WILL BE STERNLY UNDERCUT BY A STRONG COLD FRONT BLASTING SOUTH
ACROSS THE FRONT RANGE AND GREAT PLAINS. GIVEN THE MAGNITUDE OF THE
COLD AIR AHEAD OF A 1040 MB SURFACE RIDGE...WILL IN ALL LIKELIHOOD
SEE THIS BOUNDARY ARRIVE ACROSS THE FAR SOUTHERN TEXAS PANHANDLE BY
DAYBREAK SATURDAY WITH NORTH WINDS QUICKLY ACCELERATING TO 15-25
MPH AFTER SUNRISE. FALLING TEMPERATURES WILL RESULT THROUGHOUT THE
DAY VIA POTENT COLD AIR ADVECTION...WITH READINGS APPROACHING
FREEZING IN THE NORTHWEST BY LATE AFTERNOON. THE WESTERN EXTENT OF
SOME ENHANCED GULF MOISTURE MAY BE ABLE TO HOLD FIRM ACROSS THE
ROLLING PLAINS...SO HAVE THUS MAINTAINED SHOWER MENTION ALONG WITH
A SLIM CHANCE OF A THUNDERSTORM BEFORE THE COLD AIR POURS
IN...ALTHOUGH MAY BE ABLE TO EVENTUALLY PULL THUNDER PENDING THE
SPEED OF THE FRONT.
UPPER LOW DIGGING THROUGH ARIZONA WILL SLOWLY TRAVERSE EASTWARD WITH
DEEP LAYER LIFT INCREASING ACROSS THE WESTERN SOUTH PLAINS HEADING
INTO SATURDAY EVENING. TRENDS CONTINUE FOR THIS SYSTEM TO SLOW AS
IT PUSHES EASTWARD...WHICH IS TYPICAL OF A STORM OF THIS CALIBER.
PRECIPITATION SHOULD BEGIN TO FALL ACROSS THE SOUTH PLAINS AND FAR
SOUTHWEST PANHANDLE AS THE UPPER LEVEL AND ISENTROPIC LIFT
INCREASE SATURDAY EVENING...SPREADING EAST INTO THE OVERNIGHT
HOURS. SNOW LOOKS TO BE THE DOMINANT MODE ACROSS THE TYPICAL
SNOWBELT AT THE ONSET...WHILE A MIX WILL BE FOUND FARTHER SOUTH
AND EAST INITIALLY. RAPID DYNAMIC COOLING COMBINED WITH WET
BULBING SHOULD MEAN MORE SLEET AS OPPOSED TO FREEZING RAIN DURING
THE MIXED PHASE STAGE SATURDAY EVENING/NIGHT...WITH SNOW TAKING
OVER BY DAYBREAK SUNDAY. INSTABILITY AND SATURATION IN THE
DENDRITIC GROWTH LAYER CONTINUE TO LOOK FAVORABLE FOR THE THREAT
OF HEAVY SNOW...WITH AMOUNTS OF AT LEAST 4 INCHES LOOKING LIKE A
GOOD BET. WILL HOLD OFF ON WATCH ISSUANCE FOR ANOTHER PERIOD OR
TWO TO BETTER PINPOINT TIMING AND TRACK OF THE SYSTEM.
THE MAJORITY OF THE SNOW THAT FALLS WILL BE OF THE BLOWING/DRIFTING
VARIETY GIVEN THE PROLONGED PERIOD OF BRISK NORTHERLY WINDS EXPECTED
ON THE NORTH/NORTHWEST QUADRANT OF THE PARENT UPPER LOW. WHILE
TRAVEL IS HIGHLY DISCOURAGED SATURDAY NIGHT THROUGH AT LEAST EARLY
MONDAY...THOSE TRAVELING ON EAST-WEST ORIENTED HIGHWAYS WILL BE AT
GREATER RISK GIVEN THE PERPENDICULAR COMPONENT OF THE WINDS ALLOWING
FOR SNOW TO COVER ROADWAYS.
WIND CHILLS...INCLUDING SINGLE DIGIT AND BELOW ZERO READINGS...WILL
BE ANOTHER ISSUE OF CONCERN WITH TEMPERATURES REMAINING BELOW
FREEZING FROM LATE SATURDAY UNTIL LIKELY TUESDAY AFTERNOON. WIND
SPEEDS OF 25-35 MPH WILL PERSIST FROM SATURDAY NIGHT THROUGH
SUNDAY...WHILE STILL REMAINING ABOVE 20 MPH INTO MONDAY.
SPEED/TRACK OF THE UPPER LOW WILL DETERMINE HOW LONG SNOW PERSISTS INTO
MONDAY...BUT NONETHELESS SHOULD SEE THE SNOW AND WIND TAPER OFF
DURING THE DAY. HOWEVER...TRAVEL WILL STILL BE TREACHEROUS GIVEN
EXPECTED TEMPERATURES BELOW FREEZING AND SUBSEQUENT LACK OF
SNOWMELT. A SERIES OF DISTURBANCES THROUGH NEXT WEEK WILL LEAD TO
A COOL END TO THE YEAR...INCLUDING CRISP NIGHTS WHERE SNOWPACK
REMAINS IN PLACE. TRACK OF THESE SYSTEMS CURRENTLY APPEAR TOO FAR
NORTH TO WARRANT PRECIPITATION MENTION.
AS I SIGN OFF THIS MORNING...I WOULD LIKE TO LET EVERYONE KNOW WHAT
A PLEASURE IT HAS BEEN SERVING THE FOLKS OF THE SOUTH PLAINS REGION.
THANK YOU FOR MAKING MY TIME SPENT IN WEST TEXAS MEMORABLE AND
ENJOYABLE...AND I VERY MUCH LOOK FORWARD TO FUTURE RETURN VISITS. I
WISH ALL OF YOU A VERY MERRY CHRISTMAS AND A HAPPY NEW YEAR!
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1042 AM CST THU DEC 24 2015
.DISCUSSION...
KEEPING THE DENSE FOG ADVISORY UP FOR THE BAYS/NEARSHORE WATERS
FOR THE REST OF TODAY...LIKELY EXTENDING IT INTO MOST OF TOMOR-
ROW. INCREASED ONSHORE WINDS NOT EXPECTED UNTIL EARLY SAT SO WE
COULD SEE LIMITED VISIBILITIES THERE UNTIL THEN. OTHERWISE JUST
SOME TWEAKS WITH THE SHORT TERM POP/WX GRIDS WITH THE UPDATE. A
LOT OF CAPPING NOTED WITH REGIONAL 12Z SOUNDINGS AND NOT SEEING
TOO MUCH BY WAY OF SHORTWAVE ACTIVITY MOVING INTO THE AREA FROM
THE W/SW ATTM. HAVE LOWERED POPS A BIT FOR THIS AFTN/EARLY EVE-
NING AS IT LOOKS LIKE WE WILL NEED SOME TIME FOR THE AIRMASS TO
MOISTEN UP. AS SUCH STARTING TO HAVE SOME DOUBTS REGARDING POPS
FOR TONIGHT...BUT WILL LEAVE THIS AS IS FOR NOW. 41
&&
.PREV DISCUSSION... /ISSUED 744 AM CST THU DEC 24 2015/
UPDATE...
QUICK UPDATE TO EXTEND DENSE FOG ADVISORY NORTHWARD PER LATEST
SATELLITE AND OBSERVATION TRENDS. A WARM FRONT IS QUICKLY LIFTING
NORTH ACROSS THE REGION THIS MORNING... STRETCHING FROM FROM
ROUGHLY NORTHERN AUSTIN COUNTY INTO POLK COUNTY JUDGING BY THE DEW
POINT INCREASES... AND VISIBILITIES HAVE IMPROVED GENERALLY INTO
THE 3 TO 5 MILE RANGE BEHIND THE FRONT. CANCELLED SOUTHERN PORTION
OF DENSE FOG ADVISORY IN RESPONSE. HRRR HAS DONE REMARKABLY WELL
CAPTURING TRENDS THIS MORNING AND EXPECT THE DENSE FOG THREAT TO
BE SHORT LIVED GIVEN THE PROGRESS OF THE FRONT AND TIME OF DAY.
UPDATED PRODUCTS ALREADY OUT.
HUFFMAN
PREV DISCUSSION... /ISSUED 508 AM CST THU DEC 24 2015/
SHORT TERM /CHRISTMAS EVE THROUGH CHRISTMAS/...
GENERALLY QUIET CONDITIONS UNDERWAY EARLY THIS CHRISTMAS EVE
MORNING... WITH THE MAIN WEATHER CONCERN PRESENTLY DENSE FOG
ACROSS PORTION OF THE REGION. INFRARED SATELLITE IMAGERY SHOWS
THIS FOG SLOWLY EXPANDING NORTHWARD FROM THE COAST... WITH
VISIBILITIES FALLING TO LESS THAN ONE MILE. HIGH RESOLUTION
GUIDANCE SHOWS FOG CONTINUING INTO THE MID MORNING HOURS AND
CONCERNED THAT THE ADVISORY MAY NEED TO BE EXTENDED WITH FORECAST
SOUNDINGS NOT SHOWING A STOUT INVERSION LIFTING UNTIL LATE
MORNING. FOR THE MORNING FORECAST... DID EXTEND THE ADVISORY
NORTHWARD TO ROUGHLY A COLUMBUS TO LIVINGSTON LINE BASED ON
SATELLITE TRENDS.
THE REMAINDER OF THE SHORT TERM WILL BE WARM... WITH INCREASING
RAIN CHANCES. ANOTHER A DRY MORNING WILL GIVE WAY TO ISOLATED
SHOWERS THIS AFTERNOON AS A WARM FRONT BEGINS TO LIFT INLAND AND
DEEPER MOISTURE RETURNS TO THE REGION /PRECIPITABLE WATER VALUES
RISING BACK OVER ONE INCH THIS AFTERNOON AND EVENING/. NEAR RECORD
HIGH TEMPERATURES WILL BE POSSIBLE AGAIN TODAY /HIGHS IN THE MID
70S TO NEAR 80/ BUT INCREASING CLOUD COVER IS EXPECTED TO KEEP
SITES A DEGREE OR TWO COOLER THAN YESTERDAY.
FOR TONIGHT... INCREASING DIVERGENCE IN THE SOUTHWEST FLOW ALOFT
WILL RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT LATE TONIGHT
INTO EARLY CHRISTMAS MORNING. THERE IS A MARGINAL RISK THAT SOME
OF THESE STORMS MAY BECOME STRONG TO SEVERE AND CAPABLE OF
DAMAGING WINDS OR LARGE HAIL /ROUGHLY ALONG AND EAST OF A
MADISONVILLE TO HOUSTON LINE/ WITH ENOUGH SHEAR TO PROMOTE STORM
ORGANIZATION /0-6 KM BULK SHEAR AROUND 30 TO 40 KNOTS/. HOWEVER...
OVERALL WEAK FORCING WILL DO A GOOD JOB LIMITING THUNDERSTORM
COVERAGE AND FOR NOW ONLY COVERING THE AREA WITH 30-40 POPS. FOG
DEVELOPMENT... SOME POSSIBLY DENSE... IS ALSO EXPECTED AGAIN
OVERNIGHT AS OVERNIGHT LOWS FALL INTO THE 60S TO NEAR 70.
FOR CHRISTMAS DAY... ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL REMAIN POSSIBLE UNDER MOSTLY CLOUDY SKIES AS
SEVERAL WEAK DISTURBANCES CROSS THE REGION. EXPECT HIGH
TEMPERATURES TO TOP OUT IN THE UPPER 70S.
HUFFMAN
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
BY FRIDAY NIGHT... A WAVE LOCATED JUST OFF THE PACIFIC NORTHWEST
COAST EARLY THIS MORNING ON WATER VAPOR IMAGERY WILL BEGIN
TRAVELING DOWN THE WEST COAST. THIS WAVE IS EXPECTED TO CUTOFF
OVER THE DESERT SOUTHWEST ON SATURDAY... AND 00Z GUIDANCE HAS COME
INTO BETTER AGREEMENT REGARDING THE TRAJECTORY OF THIS SYSTEM. THE
CANADIAN...GFS...AND EUROPEAN ALL SWING THE UPPER LOW ACROSS
SOUTHWEST TEXAS TO NORTHEAST TEXAS LATE SUNDAY AND CLEAR THE
STATE ON MONDAY.
WHAT HAPPENS DURING THIS TIME IS EXPECTED TO BE A VERY ACTIVE
WEATHER PERIOD FOR SOUTHEAST TEXAS... AND WELL... MOST OF THE
STATE FOR THAT MATTER. AS A LEAD SHORTWAVE EJECTS OUT OF THE
TROUGH OVER THE WESTERN CONUS ACROSS COLORADO ON FRIDAY... IT
WILL DISLODGE A MUCH COLDER AIRMASS... SENDING A COLD FRONT SURGING
INTO TEXAS ON SATURDAY. AT THE SAME TIME... HEIGHT FALLS AHEAD OF
THE UPPER LOW OVER THE SOUTHWEST /ROUGHLY 5 TO 7 DECAMETERS/ ARE
EXPECTED TO INDUCE A SURFACE LOW OVER NORTHERN MEXICO. INCREASING
FORCING AHEAD OF THE UPPER LOW IS EXPECTED TO RESULT IN SCATTERED
SHOWERS AND THUNDERSTORMS ON SATURDAY... SOME OF WHICH COULD BE
STRONG TO SEVERE OVER THE NORTHERN COUNTIES AS THEY DEVELOP ALONG
AN APPROACHING COLD FRONT LATE SATURDAY INTO EARLY SUNDAY. ON SUNDAY...
THE SURFACE LOW OVER MEXICO WILL BE DRAGGED NORTHEAST WITH THE
UPPER LOW WITH A LINE OF STRONG TO SEVERE THUNDERSTORMS POSSIBLY
DEVELOPING ALONG AN ATTENDANT PACIFIC FRONT AND IMPACTING THE
REGION.
WHILE THIS EVENT IS STILL A FEW DAYS OUT... THIS PATTERN
CONTINUES TO REFLECT A SEVERE WEATHER THREAT AND HEAVY
RAIN/FLOODING THREAT FOR MUCH OF THE REGION. ALL SOUTHEAST TEXANS
ARE URGED TO CONTINUE MONITORING THE FORECAST... ESPECIALLY WITH
HOLIDAY TRAVEL POSSIBLE THIS WEEKEND.
DRIER CONDITIONS ARE EXPECTED TO SETTLE IN ACROSS THE REGION FROM
WEST TO EAST ON MONDAY AS THE SYSTEM CLEARS... WITH LITTLE TO NO
RAIN CHANCES EXPECTED THROUGH WEDNESDAY WITH VERY LITTLE MOISTURE
RECOVERY ANTICIPATED. MUCH COOLER AIR IN THE WAKE OF THE FRONT IS
EXPECTED TO DROP LOW TEMPERATURES INTO THE 30S FOR MUCH OF THE
REGION TUESDAY MORNING... WITH BELOW NORMAL TEMPERATURES
CONTINUING THROUGH THE END OF THE FORECAST.
HUFFMAN
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 77 65 77 70 78 / 10 30 40 50 50
HOUSTON (IAH) 79 68 79 70 77 / 10 40 40 40 50
GALVESTON (GLS) 74 67 73 68 73 / 10 30 40 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
744 AM CST THU DEC 24 2015
.UPDATE...
QUICK UPDATE TO EXTEND DENSE FOG ADVISORY NORTHWARD PER LATEST
SATELLITE AND OBSERVATION TRENDS. A WARM FRONT IS QUICKLY LIFTING
NORTH ACROSS THE REGION THIS MORNING... STRETCHING FROM FROM
ROUGHLY NORTHERN AUSTIN COUNTY INTO POLK COUNTY JUDGING BY THE DEW
POINT INCREASES... AND VISIBILITIES HAVE IMPROVED GENERALLY INTO
THE 3 TO 5 MILE RANGE BEHIND THE FRONT. CANCELLED SOUTHERN PORTION
OF DENSE FOG ADVISORY IN RESPONSE. HRRR HAS DONE REMARKABLY WELL
CAPTURING TRENDS THIS MORNING AND EXPECT THE DENSE FOG THREAT TO
BE SHORT LIVED GIVEN THE PROGRESS OF THE FRONT AND TIME OF DAY.
UPDATED PRODUCTS ALREADY OUT.
HUFFMAN
&&
.PREV DISCUSSION... /ISSUED 518 AM CST THU DEC 24 2015/
AVIATION...
VISIBILITIES CONTINUE TO FLUCTUATE ACROSS SE TX EARLY THIS
MORNING. A SWATH OF CIRRUS MOVING ACROSS THE REGION LOOKS LIKE
IT IS THE MECHANISM CAUSING THE DISRUPTION TO TO CIGS/VSBY.
POTENTIAL STILL EXISTS THIS MORNING FOR CIGS/VSBY TO CRASH ONCE
THE CIRRUS EXITS THE AREA. HRRR DID A GOOD JOB YESTERDAY AND WILL
STAY WITH THIS SOLUTION FOR TODAY. THIS MEANS LOW CIGS FOR MUCH OF
THE DAY AND PERIODS OF DENSE FOG AT KGLS. NAM/GFS FCST SOUNDINGS
SHOW VFR CONDS AT KCLL TRANSITIONING TO MVFR CIGS BY AFTN...WITH
TAF SITES TO SOUTH GENERALLY MVFR FOR MOST OF THE DAY BEFORE
TRANSITIONING TO IFR/LIFR TONIGHT. ADDED -DZ OVERNIGHT AS FCST
SOUNDINGS LOOK SATURATED TO AROUND 900 MB WITH DRY AIR ABOVE THIS
LAYER. S-SE WINDS WILL BE ON THE LIGHT SIDE TODAY WITH SOME
STRENGTHENING ALONG THE COAST TONIGHT AND AREAWIDE ON FRIDAY. 43
PREV DISCUSSION... /ISSUED 508 AM CST THU DEC 24 2015/
SHORT TERM /CHRISTMAS EVE THROUGH CHRISTMAS/...
GENERALLY QUIET CONDITIONS UNDERWAY EARLY THIS CHRISTMAS EVE
MORNING... WITH THE MAIN WEATHER CONCERN PRESENTLY DENSE FOG
ACROSS PORTION OF THE REGION. INFRARED SATELLITE IMAGERY SHOWS
THIS FOG SLOWLY EXPANDING NORTHWARD FROM THE COAST... WITH
VISIBILITIES FALLING TO LESS THAN ONE MILE. HIGH RESOLUTION
GUIDANCE SHOWS FOG CONTINUING INTO THE MID MORNING HOURS AND
CONCERNED THAT THE ADVISORY MAY NEED TO BE EXTENDED WITH FORECAST
SOUNDINGS NOT SHOWING A STOUT INVERSION LIFTING UNTIL LATE
MORNING. FOR THE MORNING FORECAST... DID EXTEND THE ADVISORY
NORTHWARD TO ROUGHLY A COLUMBUS TO LIVINGSTON LINE BASED ON
SATELLITE TRENDS.
THE REMAINDER OF THE SHORT TERM WILL BE WARM... WITH INCREASING
RAIN CHANCES. ANOTHER A DRY MORNING WILL GIVE WAY TO ISOLATED
SHOWERS THIS AFTERNOON AS A WARM FRONT BEGINS TO LIFT INLAND AND
DEEPER MOISTURE RETURNS TO THE REGION /PRECIPITABLE WATER VALUES
RISING BACK OVER ONE INCH THIS AFTERNOON AND EVENING/. NEAR RECORD
HIGH TEMPERATURES WILL BE POSSIBLE AGAIN TODAY /HIGHS IN THE MID
70S TO NEAR 80/ BUT INCREASING CLOUD COVER IS EXPECTED TO KEEP
SITES A DEGREE OR TWO COOLER THAN YESTERDAY.
FOR TONIGHT... INCREASING DIVERGENCE IN THE SOUTHWEST FLOW ALOFT
WILL RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT LATE TONIGHT
INTO EARLY CHRISTMAS MORNING. THERE IS A MARGINAL RISK THAT SOME
OF THESE STORMS MAY BECOME STRONG TO SEVERE AND CAPABLE OF
DAMAGING WINDS OR LARGE HAIL /ROUGHLY ALONG AND EAST OF A
MADISONVILLE TO HOUSTON LINE/ WITH ENOUGH SHEAR TO PROMOTE STORM
ORGANIZATION /0-6 KM BULK SHEAR AROUND 30 TO 40 KNOTS/. HOWEVER...
OVERALL WEAK FORCING WILL DO A GOOD JOB LIMITING THUNDERSTORM
COVERAGE AND FOR NOW ONLY COVERING THE AREA WITH 30-40 POPS. FOG
DEVELOPMENT... SOME POSSIBLY DENSE... IS ALSO EXPECTED AGAIN
OVERNIGHT AS OVERNIGHT LOWS FALL INTO THE 60S TO NEAR 70.
FOR CHRISTMAS DAY... ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL REMAIN POSSIBLE UNDER MOSTLY CLOUDY SKIES AS
SEVERAL WEAK DISTURBANCES CROSS THE REGION. EXPECT HIGH
TEMPERATURES TO TOP OUT IN THE UPPER 70S.
HUFFMAN
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
BY FRIDAY NIGHT... A WAVE LOCATED JUST OFF THE PACIFIC NORTHWEST
COAST EARLY THIS MORNING ON WATER VAPOR IMAGERY WILL BEGIN
TRAVELING DOWN THE WEST COAST. THIS WAVE IS EXPECTED TO CUTOFF
OVER THE DESERT SOUTHWEST ON SATURDAY... AND 00Z GUIDANCE HAS COME
INTO BETTER AGREEMENT REGARDING THE TRAJECTORY OF THIS SYSTEM. THE
CANADIAN...GFS...AND EUROPEAN ALL SWING THE UPPER LOW ACROSS
SOUTHWEST TEXAS TO NORTHEAST TEXAS LATE SUNDAY AND CLEAR THE
STATE ON MONDAY.
WHAT HAPPENS DURING THIS TIME IS EXPECTED TO BE A VERY ACTIVE
WEATHER PERIOD FOR SOUTHEAST TEXAS... AND WELL... MOST OF THE
STATE FOR THAT MATTER. AS A LEAD SHORTWAVE EJECTS OUT OF THE
TROUGH OVER THE WESTERN CONUS ACROSS COLORADO ON FRIDAY... IT
WILL DISLODGE A MUCH COLDER AIRMASS... SENDING A COLD FRONT SURGING
INTO TEXAS ON SATURDAY. AT THE SAME TIME... HEIGHT FALLS AHEAD OF
THE UPPER LOW OVER THE SOUTHWEST /ROUGHLY 5 TO 7 DECAMETERS/ ARE
EXPECTED TO INDUCE A SURFACE LOW OVER NORTHERN MEXICO. INCREASING
FORCING AHEAD OF THE UPPER LOW IS EXPECTED TO RESULT IN SCATTERED
SHOWERS AND THUNDERSTORMS ON SATURDAY... SOME OF WHICH COULD BE
STRONG TO SEVERE OVER THE NORTHERN COUNTIES AS THEY DEVELOP ALONG
AN APPROACHING COLD FRONT LATE SATURDAY INTO EARLY SUNDAY. ON SUNDAY...
THE SURFACE LOW OVER MEXICO WILL BE DRAGGED NORTHEAST WITH THE
UPPER LOW WITH A LINE OF STRONG TO SEVERE THUNDERSTORMS POSSIBLY
DEVELOPING ALONG AN ATTENDANT PACIFIC FRONT AND IMPACTING THE
REGION.
WHILE THIS EVENT IS STILL A FEW DAYS OUT... THIS PATTERN
CONTINUES TO REFLECT A SEVERE WEATHER THREAT AND HEAVY
RAIN/FLOODING THREAT FOR MUCH OF THE REGION. ALL SOUTHEAST TEXANS
ARE URGED TO CONTINUE MONITORING THE FORECAST... ESPECIALLY WITH
HOLIDAY TRAVEL POSSIBLE THIS WEEKEND.
DRIER CONDITIONS ARE EXPECTED TO SETTLE IN ACROSS THE REGION FROM
WEST TO EAST ON MONDAY AS THE SYSTEM CLEARS... WITH LITTLE TO NO
RAIN CHANCES EXPECTED THROUGH WEDNESDAY WITH VERY LITTLE MOISTURE
RECOVERY ANTICIPATED. MUCH COOLER AIR IN THE WAKE OF THE FRONT IS
EXPECTED TO DROP LOW TEMPERATURES INTO THE 30S FOR MUCH OF THE
REGION TUESDAY MORNING... WITH BELOW NORMAL TEMPERATURES
CONTINUING THROUGH THE END OF THE FORECAST.
HUFFMAN
MARINE...
AREAS OF FOG WILL CONTINUE TO AFFECT MARINE AREAS THROUGH THE DAY.
VSBY WILL VARY BETWEEN 1/2 AND 3 MILES AND DESPITE LIMITED IMPROVEMENT
IN VSBY TO ABOVE A MILE IN A FEW LOCATIONS PREFER TO MAINTAIN THE MARINE
DENSE FOG ADVISORY THROUGH 18Z. HRRR AND SREF ENSEMBLE GUIDANCE SUGGEST
DENSE FOG MAY LINGER NEAR THE COAST AND JUST OFFSHORE THROUGH CHRISTMAS
MORNING...AND PERHAPS LONGER.
LONG PERIOD SWELLS PROPAGATING INTO THE COASTAL WATERS WILL KEEP
SEAS SLIGHTLY ELEVATED AND WILL MAINTAIN THE SCA THROUGH 12Z FOR THE
20-60NM WATERS AND ISSUE AN SCEC FOR THE 0-20 NM THROUGH 12Z. WILL
CARRY CAUTION FLAGS FOR THE 20-60 NM WATERS FROM 12-18Z. LIGHTER
WINDS EXPECTED TODAY AND TONIGHT AS THE PRESSURE GRADIENT FLATTENS.
THE GRADIENT TIGHTENS AGAIN THIS EVENING AND ONSHORE WINDS WILL ONCE
AGAIN STRENGTHEN. ANOTHER SCEC WILL BE REQUIRED FOR THE OFFSHORE
WATERS TONIGHT. WINDS STRENGTHEN TO 20-25 KTS ON SATURDAY AS LOW
PRESSURE DEVELOPS IN WEST TEXAS. AN SCA WILL LIKELY BE REQUIRED
THROUGH SUNDAY AS THE LOW OVER WEST TEXAS SHIFTS SLOWLY EAST. A COLD
FRONT WILL CROSS THE COASTAL WATERS SUNDAY NIGHT WITH A LINE OF
STRONG STORMS AND A WIND SHIFT TO THE W-NW. ANOTHER SCA WILL BE
REQUIRED IN THE WAKE OF THE FRONT. WINDS WILL GENTLY VEER TO THE
NE-E BY TUESDAY AND DECREASE IN SPEED AS HIGH PRESSURE BUILDS TOWARD
THE NORTHERN GULF COAST.
TIDE LEVELS REMAIN AROUND A FOOT OR SO ABOVE NORMAL AND WITH A
CONTINUED STRONG ONSHORE FLOW...TIDE LEVELS SHOULD REMAIN ELEVATED
THROUGH THE WEEKEND. ATTM...COASTAL FLOODING IS NOT ANTICIPATED AS
HIGH TIDES ARE EXPECTED TO REMAIN 3.0 FEET OR LESS. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 77 65 77 70 78 / 10 30 40 50 50
HOUSTON (IAH) 79 68 79 70 77 / 20 40 40 40 50
GALVESTON (GLS) 74 67 73 68 73 / 20 30 40 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING
ZONES: BRAZOS...BURLESON...GRIMES...HOUSTON...MADISON...
POLK...SAN JACINTO...TRINITY...WALKER...WASHINGTON.
GM...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL NOON CST TODAY FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...14
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
531 AM CST THU DEC 24 2015
.AVIATION...
A WEAK COLD FRONT PASSING THROUGH THE CENTRAL PANHANDLE WILL PASS
TAF SITES BY MID MORNING WITH MODEST NORTH TO NORTHEAST POST
FRONTAL BREEZES. WINDS MAY BRIEFLY EXCEED 12 KNOTS...ESPECIALLY AT
KCDS. WINDS WILL TURN TO SOUTHEAST LATER TODAY AT BOTH KLBB AND
KPVW. OTHERWISE VFR WITH AN INCREASE IN MID LEVEL MOISTURE
EXPECTED MAINLY OVER KPVW LATER TODAY. LIGHT SHOWER CHANCES SHOULD
REMAIN NORTHWEST OF KPVW. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 456 AM CST THU DEC 24 2015/
SHORT TERM...
A WEAK COLD FRONT EXTENDING OUT OF THE DISTURBANCE IN EASTERN SOUTH
DAKOTA AND NEBRASKA...AND CROSSING THE PANHANDLE AT THIS TIME...WILL
SPREAD SOUTH ACROSS THE AREA SHORTLY AFTER DAYBREAK. NORTHERLY
BREEZES WILL BE STRONGEST OVER THE NORTHERN ROLLING PLAINS...NEAR 15
MPH LATE THIS MORNING...TRENDING LIGHTER LATER TODAY AND TURNING
SOUTHEAST ON THE CAPROCK. DRIER AIR ALSO WILL SPREAD SOUTH BEHIND
THE FRONT. ALOFT...A VERY ENERGETIC WESTERLY FLOW WILL BACK TO THE
SOUTHWEST AS POTENT STORM ENERGY CROSSES THE NORTHWEST COAST AND
STARTS DEEPENING OVER THE NORTHERN GREAT BASIN TONIGHT. BANDS OF MID
AND UPPER LEVEL MOISTURE WILL CONTINUE OVER OUR AREA TODAY AND
TONIGHT. HRRR SOLUTION AT LEAST TRIES TO BREAK OUT SPRITZY LIGHT
SHOWERS NEAR NORTHWESTERN ZONES LATER TODAY...CHANCES WILL BE SMALL
HOWEVER OWING TO THE DRIER LOWER LEVELS BEHIND THE FRONT MENTIONED
ABOVE. SLIGHTLY COOLER WITH THE FRONT TODAY AND SOME THICKENING OF
MID LEVEL CLOUDS EXPECTED DURING THE DAY...BUT STILL ABOVE NORMAL.
SLIGHTLY COOLER TONIGHT AS WELL YET ALSO STILL ABOVE NORMAL.
RMCQUEEN
LONG TERM...
LIKELIHOOD OF BLIZZARD CONDITIONS AND HEAVY SNOW CONTINUING FOR
LATE WEEKEND...
AFTER ONE MORE ABNORMALLY WARM DECEMBER DAY TO CELEBRATE
CHRISTMAS...INCREASING SOUTHWEST FLOW ALOFT BRINGING THIS WARMUP
WILL BE STERNLY UNDERCUT BY A STRONG COLD FRONT BLASTING SOUTH
ACROSS THE FRONT RANGE AND GREAT PLAINS. GIVEN THE MAGNITUDE OF THE
COLD AIR AHEAD OF A 1040 MB SURFACE RIDGE...WILL IN ALL LIKELIHOOD
SEE THIS BOUNDARY ARRIVE ACROSS THE FAR SOUTHERN TEXAS PANHANDLE BY
DAYBREAK SATURDAY WITH NORTH WINDS QUICKLY ACCELERATING TO 15-25
MPH AFTER SUNRISE. FALLING TEMPERATURES WILL RESULT THROUGHOUT THE
DAY VIA POTENT COLD AIR ADVECTION...WITH READINGS APPROACHING
FREEZING IN THE NORTHWEST BY LATE AFTERNOON. THE WESTERN EXTENT OF
SOME ENHANCED GULF MOISTURE MAY BE ABLE TO HOLD FIRM ACROSS THE
ROLLING PLAINS...SO HAVE THUS MAINTAINED SHOWER MENTION ALONG WITH
A SLIM CHANCE OF A THUNDERSTORM BEFORE THE COLD AIR POURS
IN...ALTHOUGH MAY BE ABLE TO EVENTUALLY PULL THUNDER PENDING THE
SPEED OF THE FRONT.
UPPER LOW DIGGING THROUGH ARIZONA WILL SLOWLY TRAVERSE EASTWARD WITH
DEEP LAYER LIFT INCREASING ACROSS THE WESTERN SOUTH PLAINS HEADING
INTO SATURDAY EVENING. TRENDS CONTINUE FOR THIS SYSTEM TO SLOW AS
IT PUSHES EASTWARD...WHICH IS TYPICAL OF A STORM OF THIS CALIBER.
PRECIPITATION SHOULD BEGIN TO FALL ACROSS THE SOUTH PLAINS AND FAR
SOUTHWEST PANHANDLE AS THE UPPER LEVEL AND ISENTROPIC LIFT
INCREASE SATURDAY EVENING...SPREADING EAST INTO THE OVERNIGHT
HOURS. SNOW LOOKS TO BE THE DOMINANT MODE ACROSS THE TYPICAL
SNOWBELT AT THE ONSET...WHILE A MIX WILL BE FOUND FARTHER SOUTH
AND EAST INITIALLY. RAPID DYNAMIC COOLING COMBINED WITH WET
BULBING SHOULD MEAN MORE SLEET AS OPPOSED TO FREEZING RAIN DURING
THE MIXED PHASE STAGE SATURDAY EVENING/NIGHT...WITH SNOW TAKING
OVER BY DAYBREAK SUNDAY. INSTABILITY AND SATURATION IN THE
DENDRITIC GROWTH LAYER CONTINUE TO LOOK FAVORABLE FOR THE THREAT
OF HEAVY SNOW...WITH AMOUNTS OF AT LEAST 4 INCHES LOOKING LIKE A
GOOD BET. WILL HOLD OFF ON WATCH ISSUANCE FOR ANOTHER PERIOD OR
TWO TO BETTER PINPOINT TIMING AND TRACK OF THE SYSTEM.
THE MAJORITY OF THE SNOW THAT FALLS WILL BE OF THE BLOWING/DRIFTING
VARIETY GIVEN THE PROLONGED PERIOD OF BRISK NORTHERLY WINDS EXPECTED
ON THE NORTH/NORTHWEST QUADRANT OF THE PARENT UPPER LOW. WHILE
TRAVEL IS HIGHLY DISCOURAGED SATURDAY NIGHT THROUGH AT LEAST EARLY
MONDAY...THOSE TRAVELING ON EAST-WEST ORIENTED HIGHWAYS WILL BE AT
GREATER RISK GIVEN THE PERPENDICULAR COMPONENT OF THE WINDS ALLOWING
FOR SNOW TO COVER ROADWAYS.
WIND CHILLS...INCLUDING SINGLE DIGIT AND BELOW ZERO READINGS...WILL
BE ANOTHER ISSUE OF CONCERN WITH TEMPERATURES REMAINING BELOW
FREEZING FROM LATE SATURDAY UNTIL LIKELY TUESDAY AFTERNOON. WIND
SPEEDS OF 25-35 MPH WILL PERSIST FROM SATURDAY NIGHT THROUGH
SUNDAY...WHILE STILL REMAINING ABOVE 20 MPH INTO MONDAY.
SPEED/TRACK OF THE UPPER LOW WILL DETERMINE HOW LONG SNOW PERSISTS INTO
MONDAY...BUT NONETHELESS SHOULD SEE THE SNOW AND WIND TAPER OFF
DURING THE DAY. HOWEVER...TRAVEL WILL STILL BE TREACHEROUS GIVEN
EXPECTED TEMPERATURES BELOW FREEZING AND SUBSEQUENT LACK OF
SNOWMELT. A SERIES OF DISTURBANCES THROUGH NEXT WEEK WILL LEAD TO
A COOL END TO THE YEAR...INCLUDING CRISP NIGHTS WHERE SNOWPACK
REMAINS IN PLACE. TRACK OF THESE SYSTEMS CURRENTLY APPEAR TOO FAR
NORTH TO WARRANT PRECIPITATION MENTION.
AS I SIGN OFF THIS MORNING...I WOULD LIKE TO LET EVERYONE KNOW WHAT
A PLEASURE IT HAS BEEN SERVING THE FOLKS OF THE SOUTH PLAINS REGION.
THANK YOU FOR MAKING MY TIME SPENT IN WEST TEXAS MEMORABLE AND
ENJOYABLE...AND I VERY MUCH LOOK FORWARD TO FUTURE RETURN VISITS. I
WISH ALL OF YOU A VERY MERRY CHRISTMAS AND A HAPPY NEW YEAR!
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
518 AM CST THU DEC 24 2015
.AVIATION...
VISIBILITIES CONTINUE TO FLUCTUATE ACROSS SE TX EARLY THIS
MORNING. A SWATH OF CIRRUS MOVING ACROSS THE REGION LOOKS LIKE
IT IS THE MECHANISM CAUSING THE DISRUPTION TO TO CIGS/VSBY.
POTENTIAL STILL EXISTS THIS MORNING FOR CIGS/VSBY TO CRASH ONCE
THE CIRRUS EXITS THE AREA. HRRR DID A GOOD JOB YESTERDAY AND WILL
STAY WITH THIS SOLUTION FOR TODAY. THIS MEANS LOW CIGS FOR MUCH OF
THE DAY AND PERIODS OF DENSE FOG AT KGLS. NAM/GFS FCST SOUNDINGS
SHOW VFR CONDS AT KCLL TRANSITIONING TO MVFR CIGS BY AFTN...WITH
TAF SITES TO SOUTH GENERALLY MVFR FOR MOST OF THE DAY BEFORE
TRANSITIONING TO IFR/LIFR TONIGHT. ADDED -DZ OVERNIGHT AS FCST
SOUNDINGS LOOK SATURATED TO AROUND 900 MB WITH DRY AIR ABOVE THIS
LAYER. S-SE WINDS WILL BE ON THE LIGHT SIDE TODAY WITH SOME
STRENGTHENING ALONG THE COAST TONIGHT AND AREAWIDE ON FRIDAY. 43
&&
.PREV DISCUSSION... /ISSUED 508 AM CST THU DEC 24 2015/
SHORT TERM /CHRISTMAS EVE THROUGH CHRISTMAS/...
GENERALLY QUIET CONDITIONS UNDERWAY EARLY THIS CHRISTMAS EVE
MORNING... WITH THE MAIN WEATHER CONCERN PRESENTLY DENSE FOG
ACROSS PORTION OF THE REGION. INFRARED SATELLITE IMAGERY SHOWS
THIS FOG SLOWLY EXPANDING NORTHWARD FROM THE COAST... WITH
VISIBILITIES FALLING TO LESS THAN ONE MILE. HIGH RESOLUTION
GUIDANCE SHOWS FOG CONTINUING INTO THE MID MORNING HOURS AND
CONCERNED THAT THE ADVISORY MAY NEED TO BE EXTENDED WITH FORECAST
SOUNDINGS NOT SHOWING A STOUT INVERSION LIFTING UNTIL LATE
MORNING. FOR THE MORNING FORECAST... DID EXTEND THE ADVISORY
NORTHWARD TO ROUGHLY A COLUMBUS TO LIVINGSTON LINE BASED ON
SATELLITE TRENDS.
THE REMAINDER OF THE SHORT TERM WILL BE WARM... WITH INCREASING
RAIN CHANCES. ANOTHER A DRY MORNING WILL GIVE WAY TO ISOLATED
SHOWERS THIS AFTERNOON AS A WARM FRONT BEGINS TO LIFT INLAND AND
DEEPER MOISTURE RETURNS TO THE REGION /PRECIPITABLE WATER VALUES
RISING BACK OVER ONE INCH THIS AFTERNOON AND EVENING/. NEAR RECORD
HIGH TEMPERATURES WILL BE POSSIBLE AGAIN TODAY /HIGHS IN THE MID
70S TO NEAR 80/ BUT INCREASING CLOUD COVER IS EXPECTED TO KEEP
SITES A DEGREE OR TWO COOLER THAN YESTERDAY.
FOR TONIGHT... INCREASING DIVERGENCE IN THE SOUTHWEST FLOW ALOFT
WILL RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT LATE TONIGHT
INTO EARLY CHRISTMAS MORNING. THERE IS A MARGINAL RISK THAT SOME
OF THESE STORMS MAY BECOME STRONG TO SEVERE AND CAPABLE OF
DAMAGING WINDS OR LARGE HAIL /ROUGHLY ALONG AND EAST OF A
MADISONVILLE TO HOUSTON LINE/ WITH ENOUGH SHEAR TO PROMOTE STORM
ORGANIZATION /0-6 KM BULK SHEAR AROUND 30 TO 40 KNOTS/. HOWEVER...
OVERALL WEAK FORCING WILL DO A GOOD JOB LIMITING THUNDERSTORM
COVERAGE AND FOR NOW ONLY COVERING THE AREA WITH 30-40 POPS. FOG
DEVELOPMENT... SOME POSSIBLY DENSE... IS ALSO EXPECTED AGAIN
OVERNIGHT AS OVERNIGHT LOWS FALL INTO THE 60S TO NEAR 70.
FOR CHRISTMAS DAY... ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL REMAIN POSSIBLE UNDER MOSTLY CLOUDY SKIES AS
SEVERAL WEAK DISTURBANCES CROSS THE REGION. EXPECT HIGH
TEMPERATURES TO TOP OUT IN THE UPPER 70S.
HUFFMAN
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
BY FRIDAY NIGHT... A WAVE LOCATED JUST OFF THE PACIFIC NORTHWEST
COAST EARLY THIS MORNING ON WATER VAPOR IMAGERY WILL BEGIN
TRAVELING DOWN THE WEST COAST. THIS WAVE IS EXPECTED TO CUTOFF
OVER THE DESERT SOUTHWEST ON SATURDAY... AND 00Z GUIDANCE HAS COME
INTO BETTER AGREEMENT REGARDING THE TRAJECTORY OF THIS SYSTEM. THE
CANADIAN...GFS...AND EUROPEAN ALL SWING THE UPPER LOW ACROSS
SOUTHWEST TEXAS TO NORTHEAST TEXAS LATE SUNDAY AND CLEAR THE
STATE ON MONDAY.
WHAT HAPPENS DURING THIS TIME IS EXPECTED TO BE A VERY ACTIVE
WEATHER PERIOD FOR SOUTHEAST TEXAS... AND WELL... MOST OF THE
STATE FOR THAT MATTER. AS A LEAD SHORTWAVE EJECTS OUT OF THE
TROUGH OVER THE WESTERN CONUS ACROSS COLORADO ON FRIDAY... IT
WILL DISLODGE A MUCH COLDER AIRMASS... SENDING A COLD FRONT SURGING
INTO TEXAS ON SATURDAY. AT THE SAME TIME... HEIGHT FALLS AHEAD OF
THE UPPER LOW OVER THE SOUTHWEST /ROUGHLY 5 TO 7 DECAMETERS/ ARE
EXPECTED TO INDUCE A SURFACE LOW OVER NORTHERN MEXICO. INCREASING
FORCING AHEAD OF THE UPPER LOW IS EXPECTED TO RESULT IN SCATTERED
SHOWERS AND THUNDERSTORMS ON SATURDAY... SOME OF WHICH COULD BE
STRONG TO SEVERE OVER THE NORTHERN COUNTIES AS THEY DEVELOP ALONG
AN APPROACHING COLD FRONT LATE SATURDAY INTO EARLY SUNDAY. ON SUNDAY...
THE SURFACE LOW OVER MEXICO WILL BE DRAGGED NORTHEAST WITH THE
UPPER LOW WITH A LINE OF STRONG TO SEVERE THUNDERSTORMS POSSIBLY
DEVELOPING ALONG AN ATTENDANT PACIFIC FRONT AND IMPACTING THE
REGION.
WHILE THIS EVENT IS STILL A FEW DAYS OUT... THIS PATTERN
CONTINUES TO REFLECT A SEVERE WEATHER THREAT AND HEAVY
RAIN/FLOODING THREAT FOR MUCH OF THE REGION. ALL SOUTHEAST TEXANS
ARE URGED TO CONTINUE MONITORING THE FORECAST... ESPECIALLY WITH
HOLIDAY TRAVEL POSSIBLE THIS WEEKEND.
DRIER CONDITIONS ARE EXPECTED TO SETTLE IN ACROSS THE REGION FROM
WEST TO EAST ON MONDAY AS THE SYSTEM CLEARS... WITH LITTLE TO NO
RAIN CHANCES EXPECTED THROUGH WEDNESDAY WITH VERY LITTLE MOISTURE
RECOVERY ANTICIPATED. MUCH COOLER AIR IN THE WAKE OF THE FRONT IS
EXPECTED TO DROP LOW TEMPERATURES INTO THE 30S FOR MUCH OF THE
REGION TUESDAY MORNING... WITH BELOW NORMAL TEMPERATURES
CONTINUING THROUGH THE END OF THE FORECAST.
HUFFMAN
MARINE...
AREAS OF FOG WILL CONTINUE TO AFFECT MARINE AREAS THROUGH THE DAY.
VSBY WILL VARY BETWEEN 1/2 AND 3 MILES AND DESPITE LIMITED IMPROVEMENT
IN VSBY TO ABOVE A MILE IN A FEW LOCATIONS PREFER TO MAINTAIN THE MARINE
DENSE FOG ADVISORY THROUGH 18Z. HRRR AND SREF ENSEMBLE GUIDANCE SUGGEST
DENSE FOG MAY LINGER NEAR THE COAST AND JUST OFFSHORE THROUGH CHRISTMAS
MORNING...AND PERHAPS LONGER.
LONG PERIOD SWELLS PROPAGATING INTO THE COASTAL WATERS WILL KEEP
SEAS SLIGHTLY ELEVATED AND WILL MAINTAIN THE SCA THROUGH 12Z FOR THE
20-60NM WATERS AND ISSUE AN SCEC FOR THE 0-20 NM THROUGH 12Z. WILL
CARRY CAUTION FLAGS FOR THE 20-60 NM WATERS FROM 12-18Z. LIGHTER
WINDS EXPECTED TODAY AND TONIGHT AS THE PRESSURE GRADIENT FLATTENS.
THE GRADIENT TIGHTENS AGAIN THIS EVENING AND ONSHORE WINDS WILL ONCE
AGAIN STRENGTHEN. ANOTHER SCEC WILL BE REQUIRED FOR THE OFFSHORE
WATERS TONIGHT. WINDS STRENGTHEN TO 20-25 KTS ON SATURDAY AS LOW
PRESSURE DEVELOPS IN WEST TEXAS. AN SCA WILL LIKELY BE REQUIRED
THROUGH SUNDAY AS THE LOW OVER WEST TEXAS SHIFTS SLOWLY EAST. A COLD
FRONT WILL CROSS THE COASTAL WATERS SUNDAY NIGHT WITH A LINE OF
STRONG STORMS AND A WIND SHIFT TO THE W-NW. ANOTHER SCA WILL BE
REQUIRED IN THE WAKE OF THE FRONT. WINDS WILL GENTLY VEER TO THE
NE-E BY TUESDAY AND DECREASE IN SPEED AS HIGH PRESSURE BUILDS TOWARD
THE NORTHERN GULF COAST.
TIDE LEVELS REMAIN AROUND A FOOT OR SO ABOVE NORMAL AND WITH A
CONTINUED STRONG ONSHORE FLOW...TIDE LEVELS SHOULD REMAIN ELEVATED
THROUGH THE WEEKEND. ATTM...COASTAL FLOODING IS NOT ANTICIPATED AS
HIGH TIDES ARE EXPECTED TO REMAIN 3.0 FEET OR LESS. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 77 65 77 70 78 / 10 30 40 50 50
HOUSTON (IAH) 79 68 79 70 77 / 20 40 40 40 50
GALVESTON (GLS) 74 67 73 68 73 / 20 30 40 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...CHAMBERS...COLORADO...FORT
BEND...GALVESTON...HARRIS...JACKSON...LIBERTY...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...WALLER...WHARTON.
GM...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 AM CST EARLY THIS
MORNING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL NOON CST TODAY FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...14
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
508 AM CST THU DEC 24 2015
.SHORT TERM /CHRISTMAS EVE THROUGH CHRISTMAS/...
GENERALLY QUIET CONDITIONS UNDERWAY EARLY THIS CHRISTMAS EVE
MORNING... WITH THE MAIN WEATHER CONCERN PRESENTLY DENSE FOG
ACROSS PORTION OF THE REGION. INFRARED SATELLITE IMAGERY SHOWS
THIS FOG SLOWLY EXPANDING NORTHWARD FROM THE COAST... WITH
VISIBILITIES FALLING TO LESS THAN ONE MILE. HIGH RESOLUTION
GUIDANCE SHOWS FOG CONTINUING INTO THE MID MORNING HOURS AND
CONCERNED THAT THE ADVISORY MAY NEED TO BE EXTENDED WITH FORECAST
SOUNDINGS NOT SHOWING A STOUT INVERSION LIFTING UNTIL LATE
MORNING. FOR THE MORNING FORECAST... DID EXTEND THE ADVISORY
NORTHWARD TO ROUGHLY A COLUMBUS TO LIVINGSTON LINE BASED ON
SATELLITE TRENDS.
THE REMAINDER OF THE SHORT TERM WILL BE WARM... WITH INCREASING
RAIN CHANCES. ANOTHER A DRY MORNING WILL GIVE WAY TO ISOLATED
SHOWERS THIS AFTERNOON AS A WARM FRONT BEGINS TO LIFT INLAND AND
DEEPER MOISTURE RETURNS TO THE REGION /PRECIPITABLE WATER VALUES
RISING BACK OVER ONE INCH THIS AFTERNOON AND EVENING/. NEAR RECORD
HIGH TEMPERATURES WILL BE POSSIBLE AGAIN TODAY /HIGHS IN THE MID
70S TO NEAR 80/ BUT INCREASING CLOUD COVER IS EXPECTED TO KEEP
SITES A DEGREE OR TWO COOLER THAN YESTERDAY.
FOR TONIGHT... INCREASING DIVERGENCE IN THE SOUTHWEST FLOW ALOFT
WILL RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT LATE TONIGHT
INTO EARLY CHRISTMAS MORNING. THERE IS A MARGINAL RISK THAT SOME
OF THESE STORMS MAY BECOME STRONG TO SEVERE AND CAPABLE OF
DAMAGING WINDS OR LARGE HAIL /ROUGHLY ALONG AND EAST OF A
MADISONVILLE TO HOUSTON LINE/ WITH ENOUGH SHEAR TO PROMOTE STORM
ORGANIZATION /0-6 KM BULK SHEAR AROUND 30 TO 40 KNOTS/. HOWEVER...
OVERALL WEAK FORCING WILL DO A GOOD JOB LIMITING THUNDERSTORM
COVERAGE AND FOR NOW ONLY COVERING THE AREA WITH 30-40 POPS. FOG
DEVELOPMENT... SOME POSSIBLY DENSE... IS ALSO EXPECTED AGAIN
OVERNIGHT AS OVERNIGHT LOWS FALL INTO THE 60S TO NEAR 70.
FOR CHRISTMAS DAY... ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL REMAIN POSSIBLE UNDER MOSTLY CLOUDY SKIES AS
SEVERAL WEAK DISTURBANCES CROSS THE REGION. EXPECT HIGH
TEMPERATURES TO TOP OUT IN THE UPPER 70S.
HUFFMAN
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
BY FRIDAY NIGHT... A WAVE LOCATED JUST OFF THE PACIFIC NORTHWEST
COAST EARLY THIS MORNING ON WATER VAPOR IMAGERY WILL BEGIN
TRAVELING DOWN THE WEST COAST. THIS WAVE IS EXPECTED TO CUTOFF
OVER THE DESERT SOUTHWEST ON SATURDAY... AND 00Z GUIDANCE HAS COME
INTO BETTER AGREEMENT REGARDING THE TRAJECTORY OF THIS SYSTEM. THE
CANADIAN...GFS...AND EUROPEAN ALL SWING THE UPPER LOW ACROSS
SOUTHWEST TEXAS TO NORTHEAST TEXAS LATE SUNDAY AND CLEAR THE
STATE ON MONDAY.
WHAT HAPPENS DURING THIS TIME IS EXPECTED TO BE A VERY ACTIVE
WEATHER PERIOD FOR SOUTHEAST TEXAS... AND WELL... MOST OF THE
STATE FOR THAT MATTER. AS A LEAD SHORTWAVE EJECTS OUT OF THE
TROUGH OVER THE WESTERN CONUS ACROSS COLORADO ON FRIDAY... IT
WILL DISLODGE A MUCH COLDER AIRMASS... SENDING A COLD FRONT SURGING
INTO TEXAS ON SATURDAY. AT THE SAME TIME... HEIGHT FALLS AHEAD OF
THE UPPER LOW OVER THE SOUTHWEST /ROUGHLY 5 TO 7 DECAMETERS/ ARE
EXPECTED TO INDUCE A SURFACE LOW OVER NORTHERN MEXICO. INCREASING
FORCING AHEAD OF THE UPPER LOW IS EXPECTED TO RESULT IN SCATTERED
SHOWERS AND THUNDERSTORMS ON SATURDAY... SOME OF WHICH COULD BE
STRONG TO SEVERE OVER THE NORTHERN COUNTIES AS THEY DEVELOP ALONG
AN APPROACHING COLD FRONT LATE SATURDAY INTO EARLY SUNDAY. ON SUNDAY...
THE SURFACE LOW OVER MEXICO WILL BE DRAGGED NORTHEAST WITH THE
UPPER LOW WITH A LINE OF STRONG TO SEVERE THUNDERSTORMS POSSIBLY
DEVELOPING ALONG AN ATTENDANT PACIFIC FRONT AND IMPACTING THE
REGION.
WHILE THIS EVENT IS STILL A FEW DAYS OUT... THIS PATTERN
CONTINUES TO REFLECT A SEVERE WEATHER THREAT AND HEAVY
RAIN/FLOODING THREAT FOR MUCH OF THE REGION. ALL SOUTHEAST TEXANS
ARE URGED TO CONTINUE MONITORING THE FORECAST... ESPECIALLY WITH
HOLIDAY TRAVEL POSSIBLE THIS WEEKEND.
DRIER CONDITIONS ARE EXPECTED TO SETTLE IN ACROSS THE REGION FROM
WEST TO EAST ON MONDAY AS THE SYSTEM CLEARS... WITH LITTLE TO NO
RAIN CHANCES EXPECTED THROUGH WEDNESDAY WITH VERY LITTLE MOISTURE
RECOVERY ANTICIPATED. MUCH COOLER AIR IN THE WAKE OF THE FRONT IS
EXPECTED TO DROP LOW TEMPERATURES INTO THE 30S FOR MUCH OF THE
REGION TUESDAY MORNING... WITH BELOW NORMAL TEMPERATURES
CONTINUING THROUGH THE END OF THE FORECAST.
HUFFMAN
&&
.MARINE...
AREAS OF FOG WILL CONTINUE TO AFFECT MARINE AREAS THROUGH THE DAY.
VSBY WILL VARY BETWEEN 1/2 AND 3 MILES AND DESPITE LIMITED IMPROVEMENT
IN VSBY TO ABOVE A MILE IN A FEW LOCATIONS PREFER TO MAINTAIN THE MARINE
DENSE FOG ADVISORY THROUGH 18Z. HRRR AND SREF ENSEMBLE GUIDANCE SUGGEST
DENSE FOG MAY LINGER NEAR THE COAST AND JUST OFFSHORE THROUGH CHRISTMAS
MORNING...AND PERHAPS LONGER.
LONG PERIOD SWELLS PROPAGATING INTO THE COASTAL WATERS WILL KEEP
SEAS SLIGHTLY ELEVATED AND WILL MAINTAIN THE SCA THROUGH 12Z FOR THE
20-60NM WATERS AND ISSUE AN SCEC FOR THE 0-20 NM THROUGH 12Z. WILL
CARRY CAUTION FLAGS FOR THE 20-60 NM WATERS FROM 12-18Z. LIGHTER
WINDS EXPECTED TODAY AND TONIGHT AS THE PRESSURE GRADIENT FLATTENS.
THE GRADIENT TIGHTENS AGAIN THIS EVENING AND ONSHORE WINDS WILL ONCE
AGAIN STRENGTHEN. ANOTHER SCEC WILL BE REQUIRED FOR THE OFFSHORE
WATERS TONIGHT. WINDS STRENGTHEN TO 20-25 KTS ON SATURDAY AS LOW
PRESSURE DEVELOPS IN WEST TEXAS. AN SCA WILL LIKELY BE REQUIRED
THROUGH SUNDAY AS THE LOW OVER WEST TEXAS SHIFTS SLOWLY EAST. A COLD
FRONT WILL CROSS THE COASTAL WATERS SUNDAY NIGHT WITH A LINE OF
STRONG STORMS AND A WIND SHIFT TO THE W-NW. ANOTHER SCA WILL BE
REQUIRED IN THE WAKE OF THE FRONT. WINDS WILL GENTLY VEER TO THE
NE-E BY TUESDAY AND DECREASE IN SPEED AS HIGH PRESSURE BUILDS TOWARD
THE NORTHERN GULF COAST.
TIDE LEVELS REMAIN AROUND A FOOT OR SO ABOVE NORMAL AND WITH A
CONTINUED STRONG ONSHORE FLOW...TIDE LEVELS SHOULD REMAIN ELEVATED
THROUGH THE WEEKEND. ATTM...COASTAL FLOODING IS NOT ANTICIPATED AS
HIGH TIDES ARE EXPECTED TO REMAIN 3.0 FEET OR LESS. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 77 65 77 70 78 / 10 30 40 50 50
HOUSTON (IAH) 79 68 79 70 77 / 20 40 40 40 50
GALVESTON (GLS) 74 67 73 68 73 / 20 30 40 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...CHAMBERS...COLORADO...FORT
BEND...GALVESTON...HARRIS...JACKSON...LIBERTY...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...WALLER...WHARTON.
GM...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 AM CST EARLY THIS
MORNING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL NOON CST TODAY FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...14
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
456 AM CST THU DEC 24 2015
.SHORT TERM...
A WEAK COLD FRONT EXTENDING OUT OF THE DISTURBANCE IN EASTERN SOUTH
DAKOTA AND NEBRASKA...AND CROSSING THE PANHANDLE AT THIS TIME...WILL
SPREAD SOUTH ACROSS THE AREA SHORTLY AFTER DAYBREAK. NORTHERLY
BREEZES WILL BE STRONGEST OVER THE NORTHERN ROLLING PLAINS...NEAR 15
MPH LATE THIS MORNING...TRENDING LIGHTER LATER TODAY AND TURNING
SOUTHEAST ON THE CAPROCK. DRIER AIR ALSO WILL SPREAD SOUTH BEHIND
THE FRONT. ALOFT...A VERY ENERGETIC WESTERLY FLOW WILL BACK TO THE
SOUTHWEST AS POTENT STORM ENERGY CROSSES THE NORTHWEST COAST AND
STARTS DEEPENING OVER THE NORTHERN GREAT BASIN TONIGHT. BANDS OF MID
AND UPPER LEVEL MOISTURE WILL CONTINUE OVER OUR AREA TODAY AND
TONIGHT. HRRR SOLUTION AT LEAST TRIES TO BREAK OUT SPRITZY LIGHT
SHOWERS NEAR NORTHWESTERN ZONES LATER TODAY...CHANCES WILL BE SMALL
HOWEVER OWING TO THE DRIER LOWER LEVELS BEHIND THE FRONT MENTIONED
ABOVE. SLIGHTLY COOLER WITH THE FRONT TODAY AND SOME THICKENING OF
MID LEVEL CLOUDS EXPECTED DURING THE DAY...BUT STILL ABOVE NORMAL.
SLIGHTLY COOLER TONIGHT AS WELL YET ALSO STILL ABOVE NORMAL.
RMCQUEEN
.LONG TERM...
.LIKELIHOOD OF BLIZZARD CONDITIONS AND HEAVY SNOW CONTINUING FOR
LATE WEEKEND...
AFTER ONE MORE ABNORMALLY WARM DECEMBER DAY TO CELEBRATE
CHRISTMAS...INCREASING SOUTHWEST FLOW ALOFT BRINGING THIS WARMUP
WILL BE STERNLY UNDERCUT BY A STRONG COLD FRONT BLASTING SOUTH
ACROSS THE FRONT RANGE AND GREAT PLAINS. GIVEN THE MAGNITUDE OF THE
COLD AIR AHEAD OF A 1040 MB SURFACE RIDGE...WILL IN ALL LIKELIHOOD
SEE THIS BOUNDARY ARRIVE ACROSS THE FAR SOUTHERN TEXAS PANHANDLE BY
DAYBREAK SATURDAY WITH NORTH WINDS QUICKLY ACCELERATING TO 15-25
MPH AFTER SUNRISE. FALLING TEMPERATURES WILL RESULT THROUGHOUT THE
DAY VIA POTENT COLD AIR ADVECTION...WITH READINGS APPROACHING
FREEZING IN THE NORTHWEST BY LATE AFTERNOON. THE WESTERN EXTENT OF
SOME ENHANCED GULF MOISTURE MAY BE ABLE TO HOLD FIRM ACROSS THE
ROLLING PLAINS...SO HAVE THUS MAINTAINED SHOWER MENTION ALONG WITH
A SLIM CHANCE OF A THUNDERSTORM BEFORE THE COLD AIR POURS
IN...ALTHOUGH MAY BE ABLE TO EVENTUALLY PULL THUNDER PENDING THE
SPEED OF THE FRONT.
UPPER LOW DIGGING THROUGH ARIZONA WILL SLOWLY TRAVERSE EASTWARD WITH
DEEP LAYER LIFT INCREASING ACROSS THE WESTERN SOUTH PLAINS HEADING
INTO SATURDAY EVENING. TRENDS CONTINUE FOR THIS SYSTEM TO SLOW AS
IT PUSHES EASTWARD...WHICH IS TYPICAL OF A STORM OF THIS CALIBER.
PRECIPITATION SHOULD BEGIN TO FALL ACROSS THE SOUTH PLAINS AND FAR
SOUTHWEST PANHANDLE AS THE UPPER LEVEL AND ISENTROPIC LIFT
INCREASE SATURDAY EVENING...SPREADING EAST INTO THE OVERNIGHT
HOURS. SNOW LOOKS TO BE THE DOMINANT MODE ACROSS THE TYPICAL
SNOWBELT AT THE ONSET...WHILE A MIX WILL BE FOUND FARTHER SOUTH
AND EAST INITIALLY. RAPID DYNAMIC COOLING COMBINED WITH WET
BULBING SHOULD MEAN MORE SLEET AS OPPOSED TO FREEZING RAIN DURING
THE MIXED PHASE STAGE SATURDAY EVENING/NIGHT...WITH SNOW TAKING
OVER BY DAYBREAK SUNDAY. INSTABILITY AND SATURATION IN THE
DENDRITIC GROWTH LAYER CONTINUE TO LOOK FAVORABLE FOR THE THREAT
OF HEAVY SNOW...WITH AMOUNTS OF AT LEAST 4 INCHES LOOKING LIKE A
GOOD BET. WILL HOLD OFF ON WATCH ISSUANCE FOR ANOTHER PERIOD OR
TWO TO BETTER PINPOINT TIMING AND TRACK OF THE SYSTEM.
THE MAJORITY OF THE SNOW THAT FALLS WILL BE OF THE BLOWING/DRIFTING
VARIETY GIVEN THE PROLONGED PERIOD OF BRISK NORTHERLY WINDS EXPECTED
ON THE NORTH/NORTHWEST QUADRANT OF THE PARENT UPPER LOW. WHILE
TRAVEL IS HIGHLY DISCOURAGED SATURDAY NIGHT THROUGH AT LEAST EARLY
MONDAY...THOSE TRAVELING ON EAST-WEST ORIENTED HIGHWAYS WILL BE AT
GREATER RISK GIVEN THE PERPENDICULAR COMPONENT OF THE WINDS ALLOWING
FOR SNOW TO COVER ROADWAYS.
WIND CHILLS...INCLUDING SINGLE DIGIT AND BELOW ZERO READINGS...WILL
BE ANOTHER ISSUE OF CONCERN WITH TEMPERATURES REMAINING BELOW
FREEZING FROM LATE SATURDAY UNTIL LIKELY TUESDAY AFTERNOON. WIND
SPEEDS OF 25-35 MPH WILL PERSIST FROM SATURDAY NIGHT THROUGH
SUNDAY...WHILE STILL REMAINING ABOVE 20 MPH INTO MONDAY.
SPEED/TRACK OF THE UPPER LOW WILL DETERMINE HOW LONG SNOW PERSISTS INTO
MONDAY...BUT NONETHELESS SHOULD SEE THE SNOW AND WIND TAPER OFF
DURING THE DAY. HOWEVER...TRAVEL WILL STILL BE TREACHEROUS GIVEN
EXPECTED TEMPERATURES BELOW FREEZING AND SUBSEQUENT LACK OF
SNOWMELT. A SERIES OF DISTURBANCES THROUGH NEXT WEEK WILL LEAD TO
A COOL END TO THE YEAR...INCLUDING CRISP NIGHTS WHERE SNOWPACK
REMAINS IN PLACE. TRACK OF THESE SYSTEMS CURRENTLY APPEAR TOO FAR
NORTH TO WARRANT PRECIPITATION MENTION.
AS I SIGN OFF THIS MORNING...I WOULD LIKE TO LET EVERYONE KNOW WHAT
A PLEASURE IT HAS BEEN SERVING THE FOLKS OF THE SOUTH PLAINS REGION.
THANK YOU FOR MAKING MY TIME SPENT IN WEST TEXAS MEMORABLE AND
ENJOYABLE...AND I VERY MUCH LOOK FORWARD TO FUTURE RETURN VISITS. I
WISH ALL OF YOU A VERY MERRY CHRISTMAS AND A HAPPY NEW YEAR!
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/31...END...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1013 PM EST FRI DEC 25 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL STALL OVER THE MID ATLANTIC REGION TONIGHT
AND LIFT NORTHWARD ON SATURDAY. SUNDAY AND MONDAY...A SERIES OF
STRONG LOW PRESSURE SYSTEMS WILL TRACK FROM THE SOUTHERN PLAINS TO
THE GREAT LAKES.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 1005 PM EST FRIDAY...
CANCELLED THE FLASH FLOOD WATCH...AS HEAVIER RAIN THREAT HAS ENDED
AND DO NOT SEE ANY GOOD SIGNALS UPSTREAM FOR A NEAR TERM FLASH
FLOOD THREAT THROUGH TONIGHT. WILL HAVE TO WATCH OVER THE NC
MOUNTAINS IF SURGE OF MOISTURE WITH NEXT AREA OF UPPER DIVERGENCE
OVER GA/AL CAN GET ENHANCED OVERNIGHT. THINK THE RAIN WILL BE
MODERATE AT BEST...BUT IF TRENDS FOR DEEPER CONVECTION OCCUR
ANOTHER FLASH FLOOD WATCH WOULD BE NEEDED.
SAME GOES FOR SE WV INTO THE MOUNTAINS OF FAR SW VA FOR
SATURDAY...AS MODEL TRENDS GIVE THIS AREA ANOTHER ONE HALF TO ONE
INCH POTENTIALLY SATURDAY.
CUT BACK POPS OVERNIGHT FAVORING THE FAR SW VA/NW NC MTNS INTO SRN
VA AS HIGHER CORRIDOR OF RAINFALL CHANCES. FOG IS STILL LIKELY AS
SOME LOW LVL CLOUD COVER SCATTERS OUT ESPECIALLY OVER THE
GREENBRIER VALLEY INTO THE NEW RIVER VALLEY. ATTM...STILL NOT
SEEING ANY DECENT LOW VSBY COVERAGE FOR DENSE FOG ADVISORY OR
EVENT A STATEMENT.
PREVIOUS DISCUSSION FROM EARLY EVENING...
GOING TO CUT POPS BACK SOME OVER THE NW AS NARROW BAND OF SHOWERS
IS MAINLY LINED UP ALONG A ZONE OF LOW LVL CONVERGENCE FROM TRI-
BCB...EAST TO LYH. THE LATEST GFS PLUS HIGH-RES MODELS SHOWING
MORE OF A SWD SHIFT THROUGH THIS EVENING. WILL HAVE TO WATCH THE
DEEPER CONVECTION OVER MID TN EARLY THIS EVENING...AND SEE HOW IT
SHIFTS EAST OR NORTHEAST ALONG THE FRONTAL BOUNDARY.
STILL THINK FOG WILL BECOME AN ISSUE OVER THE WEST THROUGH
TONIGHT. WILL HAVE TO MONITOR HOW WIDESPREAD AND DENSE FOG
GETS...TO DECIDE BETWEEN A DENSE FOG ADVISORY VS SPECIAL WX
STATEMENT.
PREVIOUS AFTERNOON DISCUSSION...
A FRONTAL BOUNDARY WITH SEVERAL WAVES OF LOW PRESSURE STALLS THIS
EVENING INTO TONIGHT ACROSS THE REGION AND THEN PUSHES NORTHWARD ON
SATURDAY. AN AREA OF LOW PRESSURE IN WEST VIRGINIA THIS AFTERNOON
WILL LIFT NORTHEAST AND REACH THE JERSEY SHORE TONIGHT. A SECOND
AREA OF LOW PRESSURE WILL ROTATE NORTHWARD ALONG THE BOUNDARY
TONIGHT WITH ADDITIONAL SHOWERS. THE DAY 1 EXCESSIVE RAINFALL PLACED
THE WESTERN HALF OF THE FORECAST AREA UNDER A SLIGHT RISK. CURRENT
WSR-88D SHOWED A BAND OF SHOWERS AND THUNDERSTORMS FROM WEST
VIRGINIA SOUTHWARD TO EASTERN AND MIDDLE TENNESSEE. ELECTED TO
EXTEND OUR FLASH FLOOD WATCH UNTIL MIDNIGHT...GIVEN THAT WITH RECENT
RAINFALL AND LOW FFG...IT WILL NOT TAKE MUCH TO PRODUCE FLASH
FLOODING IN THE REGION. DAY ONE CONVECTIVE OUTLOOK STILL SHOWS A
MRGL THREAT FOR SEVERE...WITH THE POTENTIAL FOR LOCALLY STRONG WIND
GUSTS INTO THIS EVENING. MCS OVER EASTERN KENTUCKY/TENNESSEE IS
PROGGED TO SPREAD EAST OF THE BLUE RIDGE LATER TODAY...WHERE IT WILL
INTERACT WITH A SEASONABLY WARM AND MOIST AIR MASS. SEVERE THREAT
WILL BE HINDER BY POOR WEAK INSTABILITY...AND POOR LAPSE RATES OVER
OUR AREA. THE HIRESW-ARW...RNK WRF AND HRRR TAKE THE AREA OF
CONVECTION TO OUR WEST AND MOVED IT EASTWARD ACROSS OUR FORECAST
AREA THIS AFTERNOON INTO TONIGHT. THE GFS...NAM AND ECMWF DROP THE
CONVECTION WITH THE FRONTAL BOUNDARY SOUTH THROUGH 00Z TO 03Z THIS
EVENING. IN ANY CASE...PLAYED THE HIGHEST POPS ACROSS THE
NORTHWEST...WITH THE LOWEST ALONG THE EASTERN SLOPES OF THE
SOUTHERN BLUE RIDGE MOUNTAINS. IT WILL BE ANOTHER MILD
NIGHT...WITH LOW TEMPERATURES FROM THE LOWER 50S IN THE NORTHERN
MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT.
OUR UNSEASONABLY WARM AND UNSETTLED PATTERN WILL CONTINUE SATURDAY.
THE UPPER PATTERN WILL FEATURE AN EASTERN RIDGE AS A CLOSED LOW
DEVELOPS OVER TEXAS AND THEN EJECTS INTO THE OHIO VALLEY. THIS WILL
PUSH THE FRONTAL BOUNDARY...WHICH HAS BEEN WAVERING AROUND THE
REGION FOR THE LAST SEVERAL DAYS...BACK TO THE NORTH AND KEEP THE
BEST CHANCES FOR PRECIPITATION...MAINLY NORTH OF ROUTE 460. HIGH
TEMPERATURES SATURDAY WILL RANGE FROM THE LOWER 60S IN THE NORTHERN
MOUNTAINS TO LOWER AND MID 70S IN THE PIEDMONT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 130 PM EST FRIDAY...
RELATIVE BREAK IN THE WET WEATHER EXPECTED OVER THE BLACKSBURG
FORECAST AREA FROM SATURDAY NIGHT THROUGH AT LEAST EARLY SUNDAY
NIGHT WITH ONLY SPOTTY WARM SECTOR SHOWERS POSSIBLE AS VERY STRONG
TROPICAL RIDGE OF HIGH PRESSURE OFF THE SE COAST OF THE NATION
DEFLECTS NORTHERN STREAM ENERGY AND MORE ROBUST PRECIPITATION FIELDS
CLOSER TO BAROCLINIC ZONE TO THE NORTH OF THE AREA. ANY RESIDUAL
COOL WEDGE ACROSS NORTHEASTERN PORTION OF THE FORECAST AREA SHOULD
RETREAT NORTH AND OUT OF THE AREA BY OR SHORTLY AFTER DAYBREAK ON
SUNDAY AS SE COASTAL RIDGE STRENGTHENS.
HOWEVER...SITUATION WILL BEGIN TO CHANGE LATER SUNDAY NIGHT INTO
MONDAY AS YET ANOTHER...AND THIS TIME STRONGER NORTHERN STREAM WAVE
MOVES EAST THROUGH THE GREAT LAKES AND NEW ENGLAND...SUPPORTING
SOUTHEASTWARD PUSH OF COOLER HIGH PRESSURE INTO SOUTHEASTERN
CANADA...WHICH THEN RIDGES SOUTHWEST INTO THE MID ATLANTIC REGION
MONDAY AFTERNOON INTO MONDAY NIGHT. MEANWHILE...YET ANOTHER
FORMIDABLE LOW LATITUDE CLOSED LOW WILL DRIFT NORTHEAST ON THE
WESTERN PERIPHERY OF THE UPPER RIDGE ALONG THE SE COAST...GRADUALLY
LIFTING AND FILLING AS IT MOVES UP THROUGH THE MS/TN/OH VALLEYS.
APPROACH OF THE WESTERN SYSTEM...AND MOVEMENT OF COOL SURFACE HIGH
PRESSURE TO AN OFFSHORE POSITION TO OUR NORTHEAST WILL RESULT IN
SLOWLY VEERING LOWER TROPOSPHERIC WINDS BACK INTO AN UPSLOPE
COMPONENT ON MONDAY...WHICH SHOULD BEGIN THE NEXT ROUND OF
WIDESPREAD PRECIPITATION FOR THE REGION. PRECIPITATION WILL
INITIALLY BE CONFINED TO LIGHT RAIN AND DRIZZLE ACROSS THE EASTERN
FLANKS OF THE APPALACHIANS LATE SUNDAY NIGHT INTO EARLY MONDAY AS
UPSLOPE COMPONENT INCREASES...BUT THEN EXPAND TO A WIDESPREAD
COVERAGE ACROSS THE ENTIRE FORECAST AREA MONDAY AFTERNOON INTO
MONDAY NIGHT AS UPWARD VERTICAL MOTION FIELDS INTENSIFY AS A RESULT
OF INCREASING WARM MOIST ADVECTION AND APPROACH OF RIGHT ENTRANCE
REGION OF UPPER JET MAXIMA.
WITH GROUND CONDITIONS ALREADY SATURATED...AND WATER LEVELS IN AREA
STREAMS/CREEKS AND RIVERS ALREADY RUNNING HIGH FROM RECENT RAINS...
THREAT FOR ADDITIONAL FLOODING/FLASH FLOODING WILL AGAIN EXIST FROM
MONDAY AFTERNOON INTO MONDAY NIGHT UNTIL CHANGE OF AIRMASS OCCURS
WITH COLD FRONTAL PASSAGE LATE MONDAY NIGHT OR AROUND DAYBREAK ON
TUESDAY.
UNTIL THEN...TEMPERATURES THROUGH THE ENTIRE SHORT TERM PERIOD WILL
CONTINUE TO REMAIN CLOSE TO OR EXCEED RECORD LEVELS...BOTH FOR VERY
HIGH NIGHTTIME LOWS...WHICH WILL REMAIN NEARLY 30F ABOVE SEASONAL
NORMALS AND AROUND 15F HIGHER THAN WHAT WOULD NORMALLY BE EXPECTED
FOR A DAYTIME HIGH TEMPERATURE...WITH DAYTIME HIGH TEMPERATURES AT
LEAST 20F ABOVE SEASONAL NORMALS...AGAIN BREAKING RECORDS. REFER TO
CLIMATOLOGICAL SECTION FOR SPECIFICS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 140 PM EST FRIDAY...
TUESDAY WILL FEATURE SOME LEFT OVER RAIN SHOWERS BEFORE THE FRONT
CAN MAKE ITS PUSH THROUGH THE REGION. WEDNESDAY LOOKS TO BE A DRIER
DAY EARLY BEFORE THE NEXT SYSTEM MOVES UP AND BRINGS ADDITIONAL RAIN
SHOWERS LATE WEDNESDAY NIGHT AND INTO THE DAY ON THURSDAY. TEMPS
TUESDAY THROUGH THURSDAY WILL REMAIN ABOVE NORMAL. TUESDAY LOOKS TO
BE THE WARMEST DAY OF THE PERIOD WITH HIGHS IN THE UPPER 50S TO
LOWER 60S...AND THEN ABOUT 5 DEGREES COOLER ON WEDNESDAY AND
THURSDAY.
A BIG PATTERN SHIFT SETS UP FOR LATE IN THE WEEK AS A
STRONG RIDGE SETS UP OUT WEST AND A TROUGH BEGINS TO DIG IN ACROSS
THE EASTERN HALF OF THE COUNTRY BRINGING MUCH COLDER AIR TO THE
REGION. SEVERAL WAVES OF ENERGY WILL RIPPLE ACROSS THROUGH NEXT
WEEKEND. MOISTURE LOOKS LIMITED BUT COULD BE ENOUGH TO SQUEAK OUT
SOME NORTHWEST FLOW PRECIP ACROSS THE WESTERN UPSLOPE
AREAS...OTHERWISE THE REST OF THE REGION LOOKS TO BE COOLER AND DRY
FOR NEXT WEEKEND.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
AS OF 633 PM EST FRIDAY...
GOING TO SEE VARIABILITY ONCE AGAIN THIS EVENING BUT OVERALL
TRENDS FROM MODELS SHOW CIGS AND VSBYS DROPPING TO MVFR OR LOWER
ESPECIALLY OVER THE MOUNTAIN TERMINALS. MAIN THREAT OF SHOWERS
WILL BE FROM TRI-BCB-ROA THIS EVENING AND AT TIMES LYH/DAN.
UPSTREAM CONVECTION OVER MID TN IS EXPECTED TO SHIFT EAST AND OR
NORTHEAST THROUGH THE NIGHT. MODELS ARE VARYING ON WHERE THIS
GOES AND INTENSITY BUT CONSENSUS IS THAT BLF-BCB-TNB WILL BE IN
THE BETTER RAINFALL CORRIDOR OVERNIGHT. UNTIL THEN WILL BE DEALING
WITH FOG FORMATION ESPECIALLY AT BCB/LWB AND AT TIMES ROA/LYH/DAN.
OVERALL CONFIDENCE IS HIGH THAT SUB VFR CONDITIONS WILL REPEAT
LIKE LAST NIGHT IN TERMS OF VSBYS...THOUGH IFFY ON WHETHER CIGS
MAINTAIN IFR/MVFR OR SWING TO VFR AT TIMES.
AS WE HEAD INTO SATURDAY...LOOKING AT AXIS OF HEAVIER RAIN TO MOVE
ACROSS KY/WV INTO OHIO BUT EAST ENOUGH TO KEEP AFFECTING LWB/BLF
AND MAYBE BCB. WITH WARM SECTOR MORE OVER THE WEST THINK BLF/LWB
COULD SWING MORE VFR IN THE AFTERNOON THOUGH HIGH PRESSURE OVER
THE NE COULD WEDGE INTO THE MID ATLANTIC KEEPING CIGS LOWER FROM
BCB/ROA EAST.
.EXTENDED AVIATION DISCUSSION...
THE CHANCE OF SHOWERS AND SUB-VFR CONDITIONS WILL CONTINUE INTO
SAT NIGHT SUNDAY THOUGH SHOWERS WILL BE LIMITED. WE ARE LESS
LIKELY TO PERSIST IN THE IFR OR WORSE VALUES AS ATMOSPHERE WILL BE
A LITTLE BETTER MIXED AND FREQUENCY OF SHOWERS MUCH LESS WITH NO
KEY FEATURES TO HELP LIFT THE MOIST ATMOSPHERE.
BEYOND THIS WEEKEND...MODELS CONTINUE TO VARY BUT SHOWING BETTER
THREAT OF SHOWERS AGAIN BY LATE MONDAY INTO TUESDAY WITH VFR TO
IFR AT TIMES.
&&
.HYDROLOGY...
AS OF 1006 PM EST FRIDAY...
FLASH FLOOD WATCH CANCELLED...BUT STILL FLOOD WARNINGS ALONG THE
DAN RIVER AND AT RANDOLPH ON THE ROANOKE RIVER. THE CLINCH AND
NORTH FORK OF THE HOLSTON IN FAR SW VA ARE ALSO RISING BUT WITH
LACK OF APPRECIABLE RAIN THROUGH EARLY OVERNIGHT...THINK THESE
RIVERS STAY BELOW FLOOD STAGE.
&&
.CLIMATE...
AS OF 230 PM EST FRIDAY...
WITH THE CONTINUING VERY WARM AIRMASS IN PLACE FOR THE NEXT
SEVERAL DAYS... MANY DAILY MAX TEMPERATURE RECORDS AS WELL AS HIGH
MIN TEMPERATURE RECORDS ARE LIKELY TO BE SET. FOR REFERENCE...HERE
ARE RECORDS FOR OUR CLIMATE STATIONS FOR THE NEXT SEVERAL DAYS.
SATURDAY 12/26/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 62 1987 -3 1983 16 1977 55 1982
KDAN 75 1982 2 1983 18 1983 57 1964
KLYH 72 1922 1 1983 22 1914 58 1964
KROA 70 1964 3 1980 23 1985 56 1982
KRNK 64 1982 -8 1985 9 1983 50 1982
SUNDAY 12/27/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 69 2008 9 1977 20 2010 52 1982
KDAN 77 1982 6 1983 27 1985 54 1964
KLYH 71 1971 0 1914 21 1925 50 1940
KROA 69 1984 -3 1914 25 1935 52 1940
KRNK 67 2008 -6 1985 20 1985 52 1964
MONDAY 12/28/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 67 1984 4 1977 20 1995 53 1984
KDAN 72 1971 13 1966 28 1950 54 2008
KLYH 76 1984 6 1977 26 1950 51 1959
KROA 75 1984 4 1925 25 1925 51 1984
KRNK 66 1984 6 1977 28 1995 42 1959
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK/WP
SHORT TERM...WERT
LONG TERM...CF
AVIATION...AMS/KK/WP
HYDROLOGY...AMS/KK/WP
CLIMATE...AMS/RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
650 PM EST FRI DEC 25 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL STALL OVER THE MID ATLANTIC REGION TONIGHT
AND LIFT NORTHWARD ON SATURDAY. SUNDAY AND MONDAY...A SERIES OF
STRONG LOW PRESSURE SYSTEMS WILL TRACK FROM THE SOUTHERN PLAINS TO
THE GREAT LAKES.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 550 PM EST FRIDAY...
GOING TO CUT POPS BACK SOME OVER THE NW AS NARROW BAND OF SHOWERS
IS MAINLY LINED UP ALONG A ZONE OF LOW LVL CONVERGENCE FROM TRI-
BCB...EAST TO LYH. THE LATEST GFS PLUS HIGH-RES MODELS SHOWING
MORE OF A SWD SHIFT THROUGH THIS EVENING. WILL HAVE TO WATCH THE
DEEPER CONVECTION OVER MID TN EARLY THIS EVENING...AND SEE HOW IT
SHIFTS EAST OR NORTHEAST ALONG THE FRONTAL BOUNDARY.
STILL THINK FOG WILL BECOME AN ISSUE OVER THE WEST THROUGH
TONIGHT. WILL HAVE TO MONITOR HOW WIDESPREAD AND DENSE FOG
GETS...TO DECIDE BETWEEN A DENSE FOG ADVISORY VS SPECIAL WX
STATEMENT.
PREVIOUS AFTERNOON DISCUSSION...
A FRONTAL BOUNDARY WITH SEVERAL WAVES OF LOW PRESSURE STALLS THIS
EVENING INTO TONIGHT ACROSS THE REGION AND THEN PUSHES NORTHWARD ON
SATURDAY. AN AREA OF LOW PRESSURE IN WEST VIRGINIA THIS AFTERNOON
WILL LIFT NORTHEAST AND REACH THE JERSEY SHORE TONIGHT. A SECOND
AREA OF LOW PRESSURE WILL ROTATE NORTHWARD ALONG THE BOUNDARY
TONIGHT WITH ADDITIONAL SHOWERS. THE DAY 1 EXCESSIVE RAINFALL PLACED
THE WESTERN HALF OF THE FORECAST AREA UNDER A SLIGHT RISK. CURRENT
WSR-88D SHOWED A BAND OF SHOWERS AND THUNDERSTORMS FROM WEST
VIRGINIA SOUTHWARD TO EASTERN AND MIDDLE TENNESSEE. ELECTED TO
EXTEND OUR FLASH FLOOD WATCH UNTIL MIDNIGHT...GIVEN THAT WITH RECENT
RAINFALL AND LOW FFG...IT WILL NOT TAKE MUCH TO PRODUCE FLASH
FLOODING IN THE REGION. DAY ONE CONVECTIVE OUTLOOK STILL SHOWS A
MRGL THREAT FOR SEVERE...WITH THE POTENTIAL FOR LOCALLY STRONG WIND
GUSTS INTO THIS EVENING. MCS OVER EASTERN KENTUCKY/TENNESSEE IS
PROGGED TO SPREAD EAST OF THE BLUE RIDGE LATER TODAY...WHERE IT WILL
INTERACT WITH A SEASONABLY WARM AND MOIST AIR MASS. SEVERE THREAT
WILL BE HINDER BY POOR WEAK INSTABILITY...AND POOR LAPSE RATES OVER
OUR AREA. THE HIRESW-ARW...RNK WRF AND HRRR TAKE THE AREA OF
CONVECTION TO OUR WEST AND MOVED IT EASTWARD ACROSS OUR FORECAST
AREA THIS AFTERNOON INTO TONIGHT. THE GFS...NAM AND ECMWF DROP THE
CONVECTION WITH THE FRONTAL BOUNDARY SOUTH THROUGH 00Z TO 03Z THIS
EVENING. IN ANY CASE...PLAYED THE HIGHEST POPS ACROSS THE
NORTHWEST...WITH THE LOWEST ALONG THE EASTERN SLOPES OF THE
SOUTHERN BLUE RIDGE MOUNTAINS. IT WILL BE ANOTHER MILD
NIGHT...WITH LOW TEMPERATURES FROM THE LOWER 50S IN THE NORTHERN
MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT.
OUR UNSEASONABLY WARM AND UNSETTLED PATTERN WILL CONTINUE SATURDAY.
THE UPPER PATTERN WILL FEATURE AN EASTERN RIDGE AS A CLOSED LOW
DEVELOPS OVER TEXAS AND THEN EJECTS INTO THE OHIO VALLEY. THIS WILL
PUSH THE FRONTAL BOUNDARY...WHICH HAS BEEN WAVERING AROUND THE
REGION FOR THE LAST SEVERAL DAYS...BACK TO THE NORTH AND KEEP THE
BEST CHANCES FOR PRECIPITATION...MAINLY NORTH OF ROUTE 460. HIGH
TEMPERATURES SATURDAY WILL RANGE FROM THE LOWER 60S IN THE NORTHERN
MOUNTAINS TO LOWER AND MID 70S IN THE PIEDMONT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 130 PM EST FRIDAY...
RELATIVE BREAK IN THE WET WEATHER EXPECTED OVER THE BLACKSBURG
FORECAST AREA FROM SATURDAY NIGHT THROUGH AT LEAST EARLY SUNDAY
NIGHT WITH ONLY SPOTTY WARM SECTOR SHOWERS POSSIBLE AS VERY STRONG
TROPICAL RIDGE OF HIGH PRESSURE OFF THE SE COAST OF THE NATION
DEFLECTS NORTHERN STREAM ENERGY AND MORE ROBUST PRECIPITATION FIELDS
CLOSER TO BAROCLINIC ZONE TO THE NORTH OF THE AREA. ANY RESIDUAL
COOL WEDGE ACROSS NORTHEASTERN PORTION OF THE FORECAST AREA SHOULD
RETREAT NORTH AND OUT OF THE AREA BY OR SHORTLY AFTER DAYBREAK ON
SUNDAY AS SE COASTAL RIDGE STRENGTHENS.
HOWEVER...SITUATION WILL BEGIN TO CHANGE LATER SUNDAY NIGHT INTO
MONDAY AS YET ANOTHER...AND THIS TIME STRONGER NORTHERN STREAM WAVE
MOVES EAST THROUGH THE GREAT LAKES AND NEW ENGLAND...SUPPORTING
SOUTHEASTWARD PUSH OF COOLER HIGH PRESSURE INTO SOUTHEASTERN
CANADA...WHICH THEN RIDGES SOUTHWEST INTO THE MID ATLANTIC REGION
MONDAY AFTERNOON INTO MONDAY NIGHT. MEANWHILE...YET ANOTHER
FORMIDABLE LOW LATITUDE CLOSED LOW WILL DRIFT NORTHEAST ON THE
WESTERN PERIPHERY OF THE UPPER RIDGE ALONG THE SE COAST...GRADUALLY
LIFTING AND FILLING AS IT MOVES UP THROUGH THE MS/TN/OH VALLEYS.
APPROACH OF THE WESTERN SYSTEM...AND MOVEMENT OF COOL SURFACE HIGH
PRESSURE TO AN OFFSHORE POSITION TO OUR NORTHEAST WILL RESULT IN
SLOWLY VEERING LOWER TROPOSPHERIC WINDS BACK INTO AN UPSLOPE
COMPONENT ON MONDAY...WHICH SHOULD BEGIN THE NEXT ROUND OF
WIDESPREAD PRECIPITATION FOR THE REGION. PRECIPITATION WILL
INITIALLY BE CONFINED TO LIGHT RAIN AND DRIZZLE ACROSS THE EASTERN
FLANKS OF THE APPALACHIANS LATE SUNDAY NIGHT INTO EARLY MONDAY AS
UPSLOPE COMPONENT INCREASES...BUT THEN EXPAND TO A WIDESPREAD
COVERAGE ACROSS THE ENTIRE FORECAST AREA MONDAY AFTERNOON INTO
MONDAY NIGHT AS UPWARD VERTICAL MOTION FIELDS INTENSIFY AS A RESULT
OF INCREASING WARM MOIST ADVECTION AND APPROACH OF RIGHT ENTRANCE
REGION OF UPPER JET MAXIMA.
WITH GROUND CONDITIONS ALREADY SATURATED...AND WATER LEVELS IN AREA
STREAMS/CREEKS AND RIVERS ALREADY RUNNING HIGH FROM RECENT RAINS...
THREAT FOR ADDITIONAL FLOODING/FLASH FLOODING WILL AGAIN EXIST FROM
MONDAY AFTERNOON INTO MONDAY NIGHT UNTIL CHANGE OF AIRMASS OCCURS
WITH COLD FRONTAL PASSAGE LATE MONDAY NIGHT OR AROUND DAYBREAK ON
TUESDAY.
UNTIL THEN...TEMPERATURES THROUGH THE ENTIRE SHORT TERM PERIOD WILL
CONTINUE TO REMAIN CLOSE TO OR EXCEED RECORD LEVELS...BOTH FOR VERY
HIGH NIGHTTIME LOWS...WHICH WILL REMAIN NEARLY 30F ABOVE SEASONAL
NORMALS AND AROUND 15F HIGHER THAN WHAT WOULD NORMALLY BE EXPECTED
FOR A DAYTIME HIGH TEMPERATURE...WITH DAYTIME HIGH TEMPERATURES AT
LEAST 20F ABOVE SEASONAL NORMALS...AGAIN BREAKING RECORDS. REFER TO
CLIMATOLOGICAL SECTION FOR SPECIFICS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 140 PM EST FRIDAY...
TUESDAY WILL FEATURE SOME LEFT OVER RAIN SHOWERS BEFORE THE FRONT
CAN MAKE ITS PUSH THROUGH THE REGION. WEDNESDAY LOOKS TO BE A DRIER
DAY EARLY BEFORE THE NEXT SYSTEM MOVES UP AND BRINGS ADDITIONAL RAIN
SHOWERS LATE WEDNESDAY NIGHT AND INTO THE DAY ON THURSDAY. TEMPS
TUESDAY THROUGH THURSDAY WILL REMAIN ABOVE NORMAL. TUESDAY LOOKS TO
BE THE WARMEST DAY OF THE PERIOD WITH HIGHS IN THE UPPER 50S TO
LOWER 60S...AND THEN ABOUT 5 DEGREES COOLER ON WEDNESDAY AND
THURSDAY.
A BIG PATTERN SHIFT SETS UP FOR LATE IN THE WEEK AS A
STRONG RIDGE SETS UP OUT WEST AND A TROUGH BEGINS TO DIG IN ACROSS
THE EASTERN HALF OF THE COUNTRY BRINGING MUCH COLDER AIR TO THE
REGION. SEVERAL WAVES OF ENERGY WILL RIPPLE ACROSS THROUGH NEXT
WEEKEND. MOISTURE LOOKS LIMITED BUT COULD BE ENOUGH TO SQUEAK OUT
SOME NORTHWEST FLOW PRECIP ACROSS THE WESTERN UPSLOPE
AREAS...OTHERWISE THE REST OF THE REGION LOOKS TO BE COOLER AND DRY
FOR NEXT WEEKEND.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 633 PM EST FRIDAY...
GOING TO SEE VARIABILITY ONCE AGAIN THIS EVENING BUT OVERALL
TRENDS FROM MODELS SHOW CIGS AND VSBYS DROPPING TO MVFR OR LOWER
ESPECIALLY OVER THE MOUNTAIN TERMINALS. MAIN THREAT OF SHOWERS
WILL BE FROM TRI-BCB-ROA THIS EVENING AND AT TIMES LYH/DAN.
UPSTREAM CONVECTION OVER MID TN IS EXPECTED TO SHIFT EAST AND OR
NORTHEAST THROUGH THE NIGHT. MODELS ARE VARYING ON WHERE THIS
GOES AND INTENSITY BUT CONSENSUS IS THAT BLF-BCB-TNB WILL BE IN
THE BETTER RAINFALL CORRIDOR OVERNIGHT. UNTIL THEN WILL BE DEALING
WITH FOG FORMATION ESPECIALLY AT BCB/LWB AND AT TIMES ROA/LYH/DAN.
OVERALL CONFIDENCE IS HIGH THAT SUB VFR CONDITIONS WILL REPEAT
LIKE LAST NIGHT IN TERMS OF VSBYS...THOUGH IFFY ON WHETHER CIGS
MAINTAIN IFR/MVFR OR SWING TO VFR AT TIMES.
AS WE HEAD INTO SATURDAY...LOOKING AT AXIS OF HEAVIER RAIN TO MOVE
ACROSS KY/WV INTO OHIO BUT EAST ENOUGH TO KEEP AFFECTING LWB/BLF
AND MAYBE BCB. WITH WARM SECTOR MORE OVER THE WEST THINK BLF/LWB
COULD SWING MORE VFR IN THE AFTERNOON THOUGH HIGH PRESSURE OVER
THE NE COULD WEDGE INTO THE MID ATLANTIC KEEPING CIGS LOWER FROM
BCB/ROA EAST.
.EXTENDED AVIATION DISCUSSION...
THE CHANCE OF SHOWERS AND SUB-VFR CONDITIONS WILL CONTINUE INTO
SAT NIGHT SUNDAY THOUGH SHOWERS WILL BE LIMITED. WE ARE LESS
LIKELY TO PERSIST IN THE IFR OR WORSE VALUES AS ATMOSPHERE WILL BE
A LITTLE BETTER MIXED AND FREQUENCY OF SHOWERS MUCH LESS WITH NO
KEY FEATURES TO HELP LIFT THE MOIST ATMOSPHERE.
BEYOND THIS WEEKEND...MODELS CONTINUE TO VARY BUT SHOWING BETTER
THREAT OF SHOWERS AGAIN BY LATE MONDAY INTO TUESDAY WITH VFR TO
IFR AT TIMES.
&&
.HYDROLOGY...
AS OF 600 PM EST FRIDAY...
FLASH FLOOD WATCH UNTIL MIDNIGHT. HIGHEST THREAT LOOKS TO BE
SHIFTED MORE TOWARD THE MOUNTAIN EMPIRE SOUTHWARD INTO NW NC. PRECIPITABLE
WATER VALUES REMAIN UNSEASONABLY HIGH WITH A DEEP LAYER OF THE
ATMOSPHERE SUPPORTING EFFICIENT WARM RAIN PROCESSES. SO SIMILAR TO
THURSDAY...RAINFALL RATES MAY REACH ONE TO TWO INCHES PER HOUR.
FOR MAINSTEM RIVERS... FLOOD WARNINGS REMAIN IN EFFECT ALONG THE
DAN RIVER FROM DANVILLE THROUGH SOUTH BOSTON.
ON THE ROANOKE RIVER A FLOOD WARNING CONTINUES FOR RANDOLPH. AT
RANDOLPH...THE RIVER WAS EXPERIENCING MODERATE FLOODING BUT THE
RIVER IS FALLING.
&&
.CLIMATE...
AS OF 230 PM EST FRIDAY...
WITH THE CONTINUING VERY WARM AIRMASS IN PLACE FOR THE NEXT
SEVERAL DAYS... MANY DAILY MAX TEMPERATURE RECORDS AS WELL AS HIGH
MIN TEMPERATURE RECORDS ARE LIKELY TO BE SET. FOR REFERENCE...HERE
ARE RECORDS FOR OUR CLIMATE STATIONS FOR THE NEXT SEVERAL DAYS.
SATURDAY 12/26/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 62 1987 -3 1983 16 1977 55 1982
KDAN 75 1982 2 1983 18 1983 57 1964
KLYH 72 1922 1 1983 22 1914 58 1964
KROA 70 1964 3 1980 23 1985 56 1982
KRNK 64 1982 -8 1985 9 1983 50 1982
SUNDAY 12/27/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 69 2008 9 1977 20 2010 52 1982
KDAN 77 1982 6 1983 27 1985 54 1964
KLYH 71 1971 0 1914 21 1925 50 1940
KROA 69 1984 -3 1914 25 1935 52 1940
KRNK 67 2008 -6 1985 20 1985 52 1964
MONDAY 12/28/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 67 1984 4 1977 20 1995 53 1984
KDAN 72 1971 13 1966 28 1950 54 2008
KLYH 76 1984 6 1977 26 1950 51 1959
KROA 75 1984 4 1925 25 1925 51 1984
KRNK 66 1984 6 1977 28 1995 42 1959
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH UNTIL MIDNIGHT EST TONIGHT FOR VAZ007-
009>020-022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH UNTIL MIDNIGHT EST TONIGHT FOR NCZ001>006-
018>020.
WV...FLASH FLOOD WATCH UNTIL MIDNIGHT EST TONIGHT FOR WVZ042>044-
507-508.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK/WP
SHORT TERM...WERT
LONG TERM...CF
AVIATION...AMS/KK/WP
HYDROLOGY...AMS/KK/WP
CLIMATE...AMS/RCS
AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION CAN BE SEEN AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 327 PM CST THU DEC 24 2015
LINGERING GUSTY WINDS WILL END DURING THE REST OF THE AFTERNOON
AS THE DEEP STORM SYSTEM WHICH PRODUCED STRONG WINDS OVERNIGHT
MOVES FURTHER NORTHEAST.
WITH THE EXCEPTION OF SOME HOLES IN THE CLOUD COVER FOR AREAS EAST
OF THE FOX RIVER EARLY THIS AFTERNOON...CLOUDS WERE PERSISTENT
ACROSS THE AREA. WHERE LOW LEVEL CLOUDS HAVE SCOURED OVER EAST
CENTRAL WISCONSIN...LOWERING MID LEVEL CLOUDS WILL BE ON THE
INCREASE THIS AFTERNOON AND EVENING AS A WEAK SHORT WAVE TRACKS
FROM IOWA TO SOUTHERN WISCONSIN. THE MODELS ARE IN SOME AGREEMENT
WITH THE NORTHERN FRINGE OF THE LIGHT SNOW BRUSHING OVER PARTS OF
CENTRAL AND EAST CENTRAL WISCONSIN THIS EVENING BEFORE DEPARTING
JUST AFTER MIDNIGHT. HRRR DIMINISHES THIS AREA OF LIGHT SNOW WHILE
WORKING NORTHWARD SO WILL MAINLY GO WITH HIGHER END CHC POPS SOUTH
OF HIGHWAY 10.
SURFACE HIGH PRESSURE REGION AND UPPER REGION BUILDS INTO THE AREA
FRIDAY FOR A QUIET XMAS DAY.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 327 PM CST THU DEC 24 2015
THE MAIN CONCERNS DURING THIS PART OF THE FORECAST ARE A COUPLE OF
SYSTEMS WITH THE POTENTIAL TO PRODUCE SEVERAL INCHES OF SNOWFALL
IN THE FORECAST AREA. THE FIRST ARRIVES LATE FRIDAY NIGHT AND THE
NEXT LOOKS TO BE EARLY IN THE UPCOMING WORK WEEK.
MODELS ONCE AGAIN SHOWED A STRONG UPPER JET STREAK NORTH OF
WISCONSIN. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE JET WILL
ASSIST AN APPROACHING MID LEVEL SHORT WAVE TROUGH IN DEVELOPING
SNOW ACROSS NORTHERN WISCONSIN FRIDAY NIGHT AND SATURDAY. HIGHEST
QPF VALUES WERE FORECAST IN THE NORTH AND THERE MAY BE SEVERAL
INCHES OF SNOW BEFORE THINGS WIND DOWN SATURDAY EVENING. MOST OF
THE 12Z MODELS SHOWED ONE LARGE AREA OF QPF DEVELOPING...THE NAM
KEPT TWO SEPARATE AREAS...AS A SURFACE LOW MOVING ALONG A COLD
FRONT ENTERS THE REGION. PRECIPITATION AMOUNTS SHOULD BE LIGHTER
BETWEEN THE TWO MAXIMA AND SOME WILL FALL AS RAIN IN PARTS OF
EASTERN WISCONSIN. SO...SNOWFALL NUMBERS ARE RATHER QUESTIONABLE
IN CENTRAL AND EASTERN WISCONSIN. SURFACE HIGH PRESSURE BUILDING
INTO THE AREA WILL KEEP A CHANCE FOR LAKE EFFECT SNOW SHOWERS IN
FAR NORTH CENTRAL WISCONSIN THROUGH AT LEAST SUNDAY.
SURFACE AND 500MB LOWS MOVING FROM THE PLAINS TO THE GREAT LAKES
REGION COULD BRING SIGNIFICANT SNOWFALL TO THE AREA...BUT THERE IS
TOO MUCH DISAGREEMENT AMONG THE MODELS TO GO WITH ANYTHING HIGHER
THAN A CHANCE FOR SNOW ON MONDAY NIGHT AND TUESDAY. THE 12Z
CANADIAN-NH BRINGS LITTLE OR NO PRECIPITATION TO THE AREA AT
ALL...WHILE THE ECMWF HAD MORE THAN 0.50 INCH OF QPF IN THE
SOUTHERN PART OF THE AREA. THE GFS LOOKED MORE SIMILAR TO THE
CANADIAN THAN TO THE EC. WILL HAVE TO KEEP A CLOSE WATCH ON THE
SYSTEM.
TEMPERATURES WILL BE ABOVE NORMAL FOR THIS TIME OF YEAR...BUT NOT
NEARLY AS WARM AS THEY HAVE BEEN IN THE RECENTLY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1131 AM CST THU DEC 24 2015
MAINLY MVFR CONDITIONS TODAY INTO TONIGHT. A PERIOD OF VFR CIGS
MAY LINGER OVER EAST CENTRAL WISCONSIN THIS AFTERNOON...BUT A
WEAK UPPER SYSTEM TRACKING OVER SOUTHERN WISCONSIN TONIGHT WILL
RETURN CIGS TO MVFR...WITH PATCHY MVFR VSBYS DUE TO SNOW FOR THE
ATW AND MTW TAFS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TDH
LONG TERM......MG
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
315 PM CST THU DEC 23 2015
.TONIGHT AND FRIDAY - CONFIDENCE...MEDIUM.
MODELS GENERALLY IN GOOD AGREEMENT IN DIMINISHING AREA OF UPSTREAM
SNOW AS IT APPROACHES THE FROM THE SOUTHWEST BY LATE AFTERNOON. MOST
MODELS INDICATE BEST CHANCE FOR ANY VERY LIGHT ACCUMULATIONS THIS
EVENING WOULD BE ACROSS THE NORTHWEST FORECAST AREA AS A SHORTWAVE
PUSHES THROUGH. LATEST NAM AND HRRR ARE SHOWING SOME ADDITIONAL
DEVELOPMENT LATE EVENING...THOUGH DEEPER MOISTURE IS DEPARTING AT
THAT TIME. COULD BE SOME DRIZZLE MIXED IN THERE IF SATURATION IS NOT
DEEP ENOUGH FOR ICE CRYSTAL FORMATION. ANY LINGERING PRECIP SHOULD
EXIT THE EAST BY AROUND 3 AM...WITH DECREASING CLOUDS TOWARD
DAYBREAK AS HIGH PRESSURE BUILDS INTO THE AREA.
HIGH PRESSURE WILL THEN BRING DRY WEATHER AND A FAIR AMOUNT OF
SUNSHINE FRIDAY...WITH HIGH TEMPERATURES REMAINING ABOVE NORMAL IN
THE UPPER 30S TO LOW 40S.
.FRIDAY NIGHT THROUGH SUNDAY - FORECAST CONFIDENCE...LOW TO MEDIUM.
DRIER EASTERLY FLOW AND LINGERING SHORT WAVE RIDGING WILL SLOW DOWN
THREAT OF LIGHT PRECIPITATION SPREADING BACK INTO SRN WI. HENCE WL
REMOVE POPS FOR MOST OF FRIDAY NIGHT...BUT KEEP SMALL CHANCE IN THE
WEST WELL AFTER 06Z.
OVER THE NEXT 24 HOURS...UPPER JET AXIS SHIFTS FROM OVER SRN WI TO
NORTHERN WI IN RESPONSE TO AMPLIFYING UPSTREAM LONG-WAVE TROFFING.
SRN WI WILL REMAIN BETWEEN TWO ACTION AREAS ON SATURDAY. ENHANCED
SYNOPTIC FORCING FROM LEFT ENTRANCE REGION OF UPPER JET WL FOCUS TO
THE NORTHWEST OF CWA ACROSS MORE OF SRN MN INTO CENTRAL/NRN WI. IN
ADDITION...THIS AREA WILL EXPERIENCE BETTER LOW LEVEL CONVERGENCE
ALONG TIGHTENING BAROCLINIC ZONE. MEANWHILE...WELL TO THE
SOUTH...STRONG FRONTAL BOUNDARY WILL REMAIN ACTIVE FROM THE OHIO
VALLEY INTO THE CENTRAL MS VALLEY REGION. WEAK LAYER Q-VECTOR
CONVERGENCE DOES PASS ACROSS SRN WI ON SAT AND EXITS THE AREA SAT
NGT. WL CONTINUE HIGHER CHANCE TO LIKELY POPS IN NORTHWEST CWA FOR
LATER FRIDAY NIGHT INTO SATURDAY AS BOTH GFS AND NAM SHOWING
MODERATE ISENTROPIC OMEGA ON 300 THETA SURFACE BRUSHING THIS AREA.
CONDENSATION PRESSURE DEFICITS DECREASE TO LESS THAN 10 MB DURING
THIS TIME. FORECAST SOUNDINGS AND TOP-DOWN APPROACH SHOW POTENTIAL
FOR A PERIOD OF -SN AND -IP INITIALLY...CHANGING OVER TO MOSTLY -RA
IN THE AFTN. 85H TEMPS DROP 10C BY SUN MRNG AS COLDER AIR SETTLES
OVER SRN WI. SOME -RA OR -SN IS POSSIBLE SAT NGT AS REMNANTS OF
UPSTREAM SHORT WAVE TROF MOVE THRU ERN AND SRN WI. BUILDING SHORT
WAVE RIDGING WL RESULT IN MOSTLY DRY AND COLDER CONDITIONS TO FINISH
OFF THE HOLIDAY WEEKEND. WL NEED TO KEEP ONE EYE ON LINGERING LOW
LEVEL MOISTURE AND POTENTIAL LAKE EFFECT LIGHT RAIN OR SNOW SHOWERS
AS DELTA-T INCREASES TO AROUND 11C BEFORE LOW LEVEL WINDS WEAKEN AND
BACK MORE TO THE NORTH. GFS AND NAM FOCUS LOW LEVEL WINDS MORE INTO
NE IL SUN MRNG HOWEVER SO KEPT SUN MRNG DRY ALONG THE LAKE FOR NOW.
.EXTENDED PERIOD...
SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE - INITIALLY HIGH
TRENDING TO LOW.
QUIET WEATHER IS EXPECTED TO START THE EXTENDED PERIOD AS THE SHORT
WAVE RIDGING THAT WILL HAVE BUILT INTO THE WESTERN GTLAKES LATER
SUNDAY LINGERS OVER THE WESTERN GTLAKES INTO MONDAY. THE COLDER
TEMPERATURES WILL PERSIST THROUGH THE EXTENDED PERIOD...BUT WILL
STILL BE ABOVE NORMAL FOR LATE DEC. THE QUIETER WEATHER LOOKS TO BE
SHORT-LIVED AS MEDIUM RANGE GUIDANCE IN GOOD AGREEMENT ON CARRYING
SOUTHERN PLAINS SHORT WAVE ON NORTHERLY PATH INTO THE VICINITY OF
THE NRN IL/IN REGION BY 12Z/TUE. HOWEVER ECMWF AND GFS DIVERGE ON
PATH OF WEATHER SYSTEM. ECMWF HAD BEEN TRENDING MORE WEST AND
WARMER OVER EARLIER MODEL RUNS...HOWEVER NEW 12Z DETERMINISTIC RUN
NOW TRENDING FARTHER EAST AND COLDER WITH THIS SYSTEM. CRITICAL
THICKNESSES SHOWING POTENTIAL FOR ICING MON NGT WITH THIS SOLUTION.
GFS AND GEM-NH SHOWING BETTER RUN TO RUN CONSISTENCY WITH COLDER
SOLUTION AND ARE TRENDING FARTHER SOUTH AND EAST...MORE TOWARD NRN
IN WITH LESS EFFECT ON SRN WI. MREF ENSEMBLE BASED ON GFS SHOWS
CONSIDERABLE VARIABILITY WITH SOME OF THE SOLUTIONS TRENDING FARTHER
WEST. WPC BLENDED FIELDS FAVOR 00Z DETERMINISTIC ECMWF AND ECMWF
BLEND WHILE NEW 12Z NH-GEM IS TRENDING TOWARD DRIER GFS. HENCE ALOT
OF UNCERTAINTY AT THIS POINT AND LOW CONFIDENCE IN SOLUTIONS FOR
THIS EARLY WEEK SYSTEM. FOR NOW WL CONTINUE LIKELY WORDING FOR SNOW
IN THE SOUTHEAST CWA WITH A CHANCE FOR SOME SLEET OR RAIN IN THE FAR
SOUTHEAST. NEED BETTER AGREEMENT BEFORE HITTING FREEZING RAIN
THREAT HARDER AT THIS POINT. WL CONTINUE POTENTIAL SNOWFALL
AND MIX MENTION IN HWO.
TUESDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE - MEDIUM.
LOOKS LIKE UNSETTLED CONDITIONS WILL CONTINUE THROUGH MID-WEEK AND
THE END OF THE EXTENDED PERIOD. LINGERING UPSTREAM TROF OVER UPPER
MIDWEST LOOKS TO SEND SEVERAL WEAK SHORT WAVES ACROSS THE WESTERN
GTLAKES DURING THE PERIOD. COLDER...MORE SEASONAL CONDITIONS SHOULD
SETTLE INTO THE REGION EARLY NEXT WEEK SO MAY BE ABLE TO FINALLY
BUILD UP SOME SNOW COVER.
&&
.AVIATION/00Z TAFS/...
WILL LIKELY SEE A LITTLE SNOW THIS EVENING...MAINLY ACROSS THE
NORTHWEST HALF OF THE FORECAST AREA AS A SHORTWAVE MOVES THROUGH THE
AREA. SNOW TOTALS LOOK LIKE A DUSTING TO A COUPLE TENTHS OF AN INCH
AT BEST. LATEST HRRR AND NAM DO SHOW SOME ADDITIONAL DEVELOPMENT
FARTHER SOUTHEAST BY LATE EVENING...POSSIBLY MIXED WITH DRIZZLE AS
DEEPER MOISTURE IS LOST. ANY LINGERING PRECIP SHOULD EXIT THE EAST
BY AROUND 09Z. THE SHORTWAVE WILL LIKELY BRING SOME LOWER CIGS FOR A
TIME...WITH VFR CONDITIONS RETURNING FOR FRIDAY UNDER HIGH PRESSURE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
$$
TONIGHT AND FRIDAY/AVIATION...DDV
FRIDAY NIGHT THROUGH THURSDAY...MBK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1010 PM CST WED DEC 23 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
AND NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 945 PM CST WED DEC 23 2015
FORECAST APPEARS TO BE ON TRACK. PCPN WAS CHANGING OVER TO SNOW
IN THE FAR WEST LATE THIS EVG...AND GIVEN THAT THE ENHANCED
SE EDGE OF THE DEFORMATION ZONE (AND SOME EMBEDDED CONVECTION)
WILL TRACK RIGHT OVER VILAS/ONEIDA COUNTIES OVER THE NEXT 3 TO 4
HOURS...EXPECT SOME GOOD ACCUMS TO OCCUR THERE. SNOW SHOULD
DIMINISH QUICK ENOUGH TO PREVENT SIGNIFICANT ACCUMS SOUTH OF THE
WINTER WX ADVISORY AREA.
WIND ADVISORY IS LOOKING GOOD TOO. THE PRESSURE GRADIENT HAS
REALLY TIGHTENED UP OVER NE IA/NW IL AND SW WI LATE THIS
EVG...ALONG WITH AN INTENSE ISALLOBARIC GRADIENT. NUMEROUS
GUSTS TO 35 TO 45 KTS WERE OCCURRING IN THIS REGION...AND
THESE SHOULD TRANSLATE INTO THE SE HALF OF GRB CWA AS THE
COLD FRONT MOVES THROUGH AROUND THE MIDNIGHT HOUR. STILL
UNCERTAIN IF WE WILL SEE SUSTAINED WINDS TO 40 MPH OR GUSTS
OVER 58 MPH OVER DOOR COUNTY...ESPECIALLY GIVEN A SW-WSW WIND
DIRECTION. DECIDED TO KEEP THE HIGH WIND WARNING GOING...BUT
TONED DOWN THE WORDING SLIGHTLY IN THE STATEMENT.
UPDATE
ISSUED AT 550 PM CST WED DEC 23 2015
MADE SOME EARLIER ADJUSTMENTS TO POPS/WX TO ACCOUNT FOR DRY
SLOTTING THAT WAS OCCURRING. SHOWERS AND SCT TSTMS WILL FILL
BACK IN OVER THE REGION IN ASSOCIATION WITH THE ARRIVAL OF THE
POTENT NEGATIVELY-TILTED S/W TROF...SFC LOW AND COLD FRONT THIS
EVG. SBCAPE/MUCAPE HAS BEEN WANING THE PAST FEW HOURS...SO NOT
CONVINCED THAT WE WILL HAVE ANY SIGNIFICANT PROBLEMS WITH THE
CONVECTION LIFTING NE OUT OF NE IA/NW IL. NEVERTHELESS...WILL
KEEP A CLOSE EYE ON IT. SUSPECT THAT RAIN WILL RAPIDLY CHANGE TO
SLEET/SNOW OVER OUR FAR WESTERN COUNTIES BETWEEN 03Z-05Z...WITH
A PERIOD OF MODERATE SNOW EXPECTED OVER FAR NC WI DURING THE
LATE EVENING/EARLY OVERNIGHT HOURS. THUS...THE WINTER WX ADVISORY
FOR VILAS/ONEIDA COUNTIES LOOKS ON TARGET. GUSTY WINDS SHOULD
QUICKLY INCREASE LATE THIS EVG...IN THE WAKE OF THE COLD FRONTAL
PASSAGE. ADVISORY CRITERIA WINDS LOOK LIKE A GOOD BET...AT LEAST
IN THE FOX VALLEY/LKSHR AREAS. NOT SURE THAT WE WILL REACH
WARNING CRITERIA FOR DOOR COUNTY...BUT NOT PLANNING ANY CHANGES
TO THE HIGH WIND WARNING AT THIS TIME.
&&
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 309 PM CST WED DEC 23 2015
PLENTY OF FORECAST CHALLENGES NEXT 24 HOURS CONCERNING WITH GUST
POTENTIAL AND AMOUNT OF RAINFALL AND RAINFALL RATES WHICH MAY
IMPACT ANY LINGERING RIVER FLOOD PROBLEMS AS WELL AS PRODUCE ANY
SMALL STREAM URBAN FLOODING ISSUES. SEE THE HYDROLOGY SECTION
BELOW FOR THE LATEST DETAIL ON FLOODING ISSUES. OTHER ISSUES
CONCERN CHANGE OVER TO SNOW TONIGHT.
A STRONG SHORT WAVE LIFTS NORTHEAST OVER THE GREAT LAKES REGION
THROUGH TONIGHT. AN ASSOCIATED SURFACE LOW WILL TRACK FROM IOWA
LATE THIS AFTERNOON TO CENTRAL UPPER MICHIGAN AROUND MIDNIGHT AND
DEEPEN. THE LOW WILL ALSO A DRAG WARM FRONT OVER NORTHEAST
WISCONSIN THIS AFTERNOON INTO THIS EVENING. MILDER AIR SPREADING
INTO EAST CENTRAL AND FAR NORTHEAST WISCONSIN WILL ALLOW A VERY
MILD AIR MASS WITH POSSIBLE RECORD HIGHS TO INVADE THE AREA.
HIGHEST TOTAL TOTALS NUMBERS IN THE LOWER 50S MID EVENING AS PER
GRB BUFKIT DATA. THIS WILL ALSO RESULT IN A MORE UNSTABLE AIR
MASS AND MAY PROMOTE BETTER MIXING OF STRONG WINDS TO THE
SURFACE...ESPECIALLY WITH ANY CONVECTION. HRRR PROGGED DEVELOPMENT
OF THIS CONVECTION OF CONCERN ALONG AND AHEAD OF THE FRONT OVER
NORTHERN MO AND SOUTHERN IOWA AND SO FAR IS VERIFYING. THIS NEXT
ROUND IS PROGGED TO SWEEP OVER THE AREA THIS EVENING.
PROBLEM 2 WITH THE WINDS OCCUR LATE TONIGHT AS THE DEEPENING LOW
PRESSURE DEPARTS NORTHEAST AND LEAVES A STRONG PRESSURE GRADIENT
OVER MUCH OF THE STATE. A STRONG PRESSURE CHANGE COUPLET SLIDES
OVER NORTHEAST WISCONSIN IN THE WAKE OF THE SURFACE LOW. WILL
CONTINUE WITH THE WIND ADVISORY AND WILL ISSUE FOR DOOR DUE TO THE
WESTERLY COMPONENT. ITS POSSIBLE THE HIGH WIND ADVISORIES AND
WARNINGS MAY NEED TO BE EXPANDED DEPENDING ON THE LOW PRESSURE
TRACK.
PCPN TYPE INITIALLY NOT AN ISSUE BUT COULD SEE SOME HAIL OR
GRAUPEL WITH ANY CONVECTION THIS EVENING. LATER EVENING INTO THE
MORNING...COLDER AIR POURING IN WILL CHANGE THE PCPN TYPE TO
SNOW. WHILE SNOW RANGES MOSTLY IN THE 2-4 RANGES FOR NC WI...THE
SNOW WIND COMBO WARRANTS AN ADVISORY LATER TONIGHT. RADAR SOUTHERN
LOOP SUGGESTS REACHING NC WI AND CHANGEOVER AND ISSUE. BUT DID
NOTICE SOME THUNDER WITH THE SURFACE LOW OVER IOWA.
SYSTEM GRADUALLY DEPARTS THURSDAY WITH DIMINISHING WINDS IN THE
MORNING. TEMPERATURES NEAR STEADY ON THURSDAY.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 309 PM CST WED DEC 23 2015
AMPLIFIED MEAN FLOW TO REMAIN INTACT THRU THE END OF THE WORK WEEK
WITH AN ERN PACIFIC UPR RDG...WRN CONUS UPR TROF AND BERMUDA UPR
RDG. THE UPR TROF IS FCST TO CLOSE OFF INTO AN UPR LOW OVER WEST
TX THIS WEEKEND BEFORE LIFTING NE INTO THE GREAT LAKES EARLY NEXT
WEEK. PCPN CHCS WL BE FOCUSED FRI NGT/SAT ASSOCIATED WITH A TIGHT
BAROCLINIC ZONE/JET ENERGY AND MON NGT/TUE WITH THE UPR LOW/
ASSOCIATED SFC LOW. PCPN TYPE ISSUES WL ALSO BE A PROBLEM WITH
BOTH OF THESE SYSTEMS AS TEMPS FLUCTUATE BELOW FREEZING AT NGT AND
RISE ABOVE FREEZING IN PLACES DURING THE DAY. THERE IS SNOW
ACCUMULATION POTENTIAL FOR CNTRL/NRN WI FRI NGT AND OVER THE
ENTIRE AREA MON NGT/TUE.
A WEAK AREA OF HI PRES IS FCST TO APPROACH SRN SECTIONS OF THE
GREAT LAKES THU NGT AND SHOULD KEEP THE FCST AREA DRY. IT MAY TAKE
MOST OF THE NGT TO TRY AND SCOUR OUT LINGERING LOW/MID-LEVEL
MOISTURE...THUS PARTLY TO MOSTLY CLOUDY SKIES SHOULD SUFFICE. MIN
TEMPS TO RANGE FROM THE MID TO UPR TEENS NORTH...LWR 20S CNTRL...
AND MID TO UPR 20S E-CNTRL WI. THESE DRY CONDITIONS ARE EXPECTED
TO PERSIST THRU CHRISTMAS DAY AS THE SFC HI SLIDES EAST TOWARD THE
ERN GREAT LAKES. UNDER PARTLY CLOUDY SKIES AND RELATIVELY LIGHT
WINDS...LOOK FOR MAX TEMPS TO REACH THE LWR TO MID 30S NORTH...
MID TO UPR 30S SOUTH.
FCST CONFIDENCE DROPS RATHER QUICKLY LATE FRI NGT INTO SAT AS AN
UPR TROF DEEPENS OVER THE ROCKIES...INDIVIDUAL SHORTWAVES EJECT
OUT OF THIS TROF NEWD THRU THE CNTRL CONUS...A STALLED FRONTAL
BOUNDARY TO OUR SOUTH BECOMES MORE ACTIVE AND GULF MOISTURE LIFTS
NORTH ALONG THIS FRONTAL BOUNDARY TOWARD THE GREAT LAKES. MODELS
BRING THE LEADING EDGE OF PCPN INTO NE WI LATE FRI NGT WHEN TEMPS
WL BE COLD ENUF TO ALLOW PCPN TO FALL AS ALL SNOW. THE ISSUES FOR
SAT ARE WHERE THE HIGHEST QPF WL FALL AND WHAT THE PCPN TYPE WL
BE. THIS IS WHERE THE MODELS DIFFER AS THE GFS/ECMWF FOCUS THE
HEAVIER PCPN TO THE NORTH AND ALLOW FOR WARMER AIR TO LIFT FARTHER
NORTH INTO WI...THUS A MIXED PCPN EVENT FOR CNTRL/E-CNTRL WI WITH
SNOW NORTH. THE GEM IS FARTHEST SOUTH WITH THE HEAVIER PCPN (SRN
WI) AND COOLER AIR...THUS KEEPING ALL OUR PCPN AS ALL SNOW. THE
BETTER FRONTOGENETICAL FORCING SIGNAL AND LOCATION OF THE BEST
LIFT FROM THE RIGHT ENTRANCE REGION OF THE UPR JET FAVOR NRN WI
WITH THE HIGHER QPF...THUS WL CONT THE MENTION OF SNOW NORTH AND
SNOW BECOMING MIXED WITH RAIN FOR CNTRL/E-CNTRL WI. POTENTIAL SNOW
ACCUMULATION OF 3-5" IS POSSIBLE OVER THE NORTH FRI NGT INTO
SAT...BUT ANY WAVERING ON THE STRONGER LIFT/FORCING COUDL ALTER
THESE VALUES.
AS THE STRONGER DYNAMICS SHIFT TO THE EAST SAT NGT...MODELS
INDICATE CAA TO TAKE OVER ACROSS WI...THUS ANY LINGERING RAIN OVER
CNTRL OR E-CNTRL WI WL TRANSITION TO ALL SNOW. DO NOT ANTICIPATE
MUCH (IF ANY) ADDITIONAL ACCUMULATION SAT NGT AS MOST OF THE
MOISTURE TO HAVE BEEN SHUNTED EAST. A STRONG AREA OF HI PRES IS
FCST TO BUILD ACROSS THE UPR MS VALLEY ON SUNDAY AND SEND ENUF DRY
AIR INTO WI TO ALLOW SKIES TO BECOME AT LEAST PARTLY CLOUDY.
DESPITE THE CAA AND NORTH WINDS AT 5 TO 15 MPH...MAX TEMPS ARE
FCST TO REMAIN ABOVE NORMAL ON SUNDAY BY AROUND 5 DEGS (MID 20S
N-CNTRL TO LWR 30S E-CNTRL WI).
THE CORE OF THIS STRONG HI PRES IS PROGGED TO MOVE ACROSS WRN
ONTARIO SUNDAY NGT AND VEER THE WINDS TO THE NE. WL HAVE TO WATCH
FOR POTENTIAL OF LK EFFECT SNOW SHWRS FROM LK MI AS TEMPS/DELTA-T
VALUES WOULD SUPPORT THE DEVELOPMENT OF LIGHT SNOW. ONE NEGATIVE
IS THAT THE WINDS CONT TO VEER THRU THE NGT (FROM NORTH TO
E-NE)...THUS IT MAY PROVE DIFFICULT FOR SNOW BANDS TO FOCUS ON ANY
ONE PARTICULAR AREA. OTHERWISE...THE OTHER BIG STORY WL BE THE
APPROACH OF ANOTHER STRONG AREA OF LOW PRES/CLOSED UPR LOW INTO
THE MID-MS VALLEY ON MON. LATEST THINKING IS THAT THERE WL BE ENUF
DRY AIR ON GUSTY EAST WINDS FROM ONTARIO HI PRES TO DELAY THE
ONSET OF ANY PCPN INTO NE WI ON MON. HAVE REDUCED POPS AND WOULD
EXPECT ALMOST A COMPLETELY DRY DAY FOR MON WITH MAX TEMPS IN THE
UPR 20S TO LWR 30S.
MODELS CONT TO DIFFER WITH THE TIMING/EVENTUAL TRACK OF THIS
STRONG SYSTEM MON NGT INTO TUE WITH THE GFS/GEM FAVORING A
QUICKER/FARTHER EAST TRACK VERSUS THE SLOWER/FARTHER WEST TRACK OF
THE ECMWF. THE GFS/GEM SOLUTION WOULD PROVIDE A QUICK-HITTING SNOW
EVENT FOR MAINLY THE SE HALF OF WI MON NGT BEFORE PULLING AWAY ON
TUE. THE ECMWF SOLUTION WOULD BRING A SWATH OF SNOW ACROSS ALL
OF NE WI MON NGT BEFORE MIXING IN RAIN OVER CNTRL/E-CNTRL WI ON
TUE WITH ADDITIONAL SNOWS FOR NRN WI. IF THE ECMWF SOLUTION
PREVAILS...WE WOULD BE LOOKING AT HEADLINES FOR SNOW...HOWEVER
THERE IS TOO MUCH UNCERTAINTY YET SO HAVE FOLLOWED A MODEL BLEND
FOR NOW WITH HIGHER CHC POPS IN THE FCST FOR BOTH MON NGT AND TUE.
EVEN GOING INTO WED...THERE IS MODEL DISAGREEMENT WITH RESPECT TO
THE TRACK OF THE SECONDARY/WEAKER UPR LOW THAT WOULD LIFT NE INTO
THE REGION. SINCE MODELS ARE INCONSISTENT WITH THIS
FEATURE...PREFER TO KEEP THE FCST DRY FOR NOW...BUT WOULD EXPECT
SOME SMALL POPS TO BE ADDED AS WE GET CLOSER TO WED.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 945 PM CST WED DEC 23 2015
A STEADY RAIN WAS CHANGING TO SNOW OVER NC/C WI LATE THIS EVG.
MODERATE SNOW WILL LIKELY OCCUR OVER FAR NC WI...INCLUDING THE
RHI TAF SITE...FOR THE FIRST COUPLE HOURS OF THE TAF PERIOD.
FARTHER EAST...SHOWERS AND ISOLD TSTMS WILL TAPER OFF
OVERNIGHT...AND SHOULD END AT GRB/ATW/MTW BEFORE THE AIR MASS IS
COLD ENOUGH TO SUPPORT SNOW. FLIGHT CONDITIONS SHOULD IMPROVE
TO MVFR/VFR AS THE PCPN ENDS OVERNIGHT.
STRONG GUSTY SW-W WINDS WILL DEVELOP IN THE WAKE OF A COLD
FRONTAL PASSAGE...AND CONTINUE THROUGH THURSDAY MORNING BEFORE
DIMINISHING. GUSTS AS HIGH AS 35 TO 45 KTS ARE EXPECTED IN THE
FOX VALLEY/LKSHR AREAS.
&&
.MARINE...
ISSUED AT 309 PM CST WED DEC 23 2015
HIGH-END GALES ARE STILL LIKELY WITH THIS STORM....BUT WILL
MENTION STORM FORCE WIND GUSTS. IN ADDITION WILL ALSO MENTION A
PERIOD OF FOG THOUGH THE EVENING HOURS.
&&
.HYDROLOGY...
ISSUED AT 309 PM CST WED DEC 23 2015
MOST RIVERS HAVE RECOVERED FROM THE HEAVY RAINS OVER A WEEK
AGO...EXCEPT FOR THE LOW LYING AREAS ALONG THE WOLF RIVER SOUTH OF
SHAWANO TO LAKE POYGAN. WITH THIS RAINFALL EXPECTED TO BE IN A
SHORTER TIME FRAME...AN INCH OF RAIN COULD PRODUCE ENOUGH RUN OFF
FOR SOME MINOR URBAN SMALL STREAM FLOODING. THIS WOLF RIVER LEVELS
MAY HOLD STEADY FOR A FEW MORE DAYS WITH THIS ADDITIONAL RAINFALL.
BUT LATEST RADAR TRENDS SUGGEST SOME DRY SLOTTING AS AN AREA OF
ELEVATED CONVECTION IS SWEEPING NORTHEAST OF THE AREA...WITH THE
NEXT ROUND OF CONVECTION APPROACHING FROM IOWA. AS A RESULT RAIN
AMOUNTS TO BE LESS ROUGHLY FORM 0.30 TO 0.50. SEE
WEATHER.GOV/AHPS FOR AVAILABLE FORECASTS FOR NORTHEAST WISCONSIN
RIVERS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL NOON CST THURSDAY FOR WIZ020-021-031-037>040-
045-048>050-073-074.
HIGH WIND WARNING UNTIL NOON CST THURSDAY FOR WIZ022.
WINTER WEATHER ADVISORY UNTIL 4 AM CST THURSDAY FOR WIZ005-010.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....TDH
LONG TERM......AK
AVIATION.......KIECKBUSCH
MARINE.........TDH
HYDROLOGY......TDH
AREA FORECAST DISCUSSION
NWS TUCSON AZ
258 AM MST SAT DEC 26 2015
.SYNOPSIS...A COLD STORM SYSTEM WILL IMPACT PARTS OF SOUTHEAST
ARIZONA THROUGH THE WEEKEND...WITH MOST OF THE PRECIPITATION
OCCURRING EAST OF TUCSON AND IN THE MOUNTAINS. WIND WILL BE GUSTY
WINDS AT TIMES AND MUCH COLDER TEMPERATURES ARE EXPECTED THIS
WEEKEND. ANOTHER SYSTEM COULD BRING A CHANCE OF VALLEY RAIN AND
MOUNTAIN SNOW MONDAY NIGHT INTO TUESDAY.
&&
.DISCUSSION...AN UPPER LOW CONTINUED TO EVOLVE OVER THE STATE EARLY
THIS MORNING...WITH A NICE TAP OF MOISTURE BEING PULLED NORTHWARD
THROUGH SOUTHEAST ARIZONA INTO THE CENTRAL PLAINS. RECENT SATELLITE
AND RADAR IMAGERY WERE SHOWING A BAND OF LOW CLOUDS EXTENDING FROM
THE WHITE MOUNTAINS SOUTHWEST TO TUCSON AND NOGALES. SPRINKLES AND
SNOW FLURRIES HAVE BEEN REPORTED NEAR TUCSON AND IN THE SIERRA VISTA
AREA. LATEST HRRR SOLUTIONS SHIFT THIS BAND OF CLOUDS AND LIGHT
PRECIPITATION EASTWARD...EXITING THE AREA THIS AFTERNOON. WILL
LIKELY SEE SOME WRAP AROUND CLOUDINESS AND SHOWERS THIS AFTERNOON
AND EVENING EAST OF TUCSON AS THE UPPER LOW TRACKS SOUTHEAST OF THE
AREA. STORM TOTAL SNOW ACCUMULATIONS WILL RANGE FROM LIGHT AMOUNTS
WITH ISOLATED SPOTS UP TO 1 INCH IN THE VALLEYS OF COCHISE AND
GRAHAM COUNTIES TO 3 TO 6 INCHES ABOVE 6500 FEET IN THE EASTERN
MOUNTAINS. THE LOW PRESSURE SYSTEM WILL ALSO USHER IN A MUCH COLDER
AIR MASS TODAY WITH HIGHS ABOUT 10 TO 15 DEGREES BELOW NORMAL.
CLEARING SKIES TONIGHT IN COMBINATION WITH THE COLDER AIR MASS WILL
RESULT IN A WIDESPREAD HARD FREEZE IN THE LOWER DESERTS
TONIGHT/SUNDAY MORNING. A HARD FREEZE WARNING HAS BEEN POSTED FOR
PARTS OF PINAL AND PIMA COUNTIES FROM MIDNIGHT TONIGHT UNTIL 8 AM
MST SUNDAY. ALONG WITH THE PRECIPITATION AND COLDER TEMPERATURES...
STRONG AND GUSTY WINDS CAN BE ANTICIPATED TODAY ESPECIALLY IN THE
UPPER GILA RIVER VALLEY AROUND SAFFORD. A SECONDARY SYSTEM WILL
BRING ANOTHER CHANCE OF SHOWERS AND COOLER TEMPERATURES LATE MONDAY
INTO TUESDAY.
&&
.AVIATION...VALID THRU 27/12Z.
EXPECT ISOLATED TO SCATTERED -SHRASN EAST OF KTUS THRU THE FORECAST
PERIOD. MOUNTAIN TOPS WILL BE OBSCURED AT TIMES IN CLOUDS/PRECIP AND
MVFR CIGS/VSBYS ARE POSSIBLE IN VALLEYS NEAR NM STATE LINE AFT
26/18Z. DRY CONDITIONS WILL PREVAIL FROM KTUS VICINITY WEST AND
NORTHWEST TOWARD KPHX. OTHERWISE VALLEY CLOUD BASES WILL MAINLY
RANGE FROM 4K-8K FT AGL. SFC WIND WLY/NWLY AT 10-15 KTS TIL 26/18Z.
AFT 26/18Z...NWLY SFC WIND INCREASING TO 15-25 KTS IN FAVORED VALLEY
LOCATIONS...WITH GUSTS TO 30-35 KTS...STRONGER IN THE VCNTY OF KSAD.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THERE WILL BE A CHANCE OF VALLEY RAIN AND MOUNTAIN
SNOW SHOWERS EAST OF TUCSON THROUGH TONIGHT. DRY CONDITIONS WILL
PREVAIL FROM TUCSON WESTWARD INTO WESTERN PIMA COUNTY AND SOUTHERN
PINAL COUNTY. A SLIGHT CHANCE OF VALLEY RAIN AND MOUNTAIN SNOW
SHOWERS CONTINUES MAINLY NEAR THE NEW MEXICO BORDER ON SUNDAY...THEN
DRY CONDITIONS ARE EXPECTED AREA-WIDE SUNDAY NIGHT INTO MONDAY. A
FAST MOVING SYSTEM WILL BRING ISOLATED TO SCATTERED VALLEY RAIN AND
MOUNTAIN SNOW SHOWERS FROM TUCSON EASTWARD MONDAY NIGHT AND TUESDAY.
DRY CONDITIONS WILL THEN PREVAIL NEXT WEDNESDAY THROUGH FRIDAY.
EXPECT GUSTY NORTHWEST WINDS TODAY...WITH THE STRONGEST WINDS DURING
THE AFTERNOON HOURS...AND ESPECIALLY IN THE UPPER GILA VALLEY
INCLUDING SAFFORD...WITH GUSTS OF 30-40 MPH POSSIBLE. GENERALLY
LIGHT TERRAIN DRIVEN WINDS WILL THEN PREVAIL DURING MUCH OF THE
UPCOMING WEEK. THE EXCEPTION IS NEXT FRIDAY WHEN GUSTY EAST WINDS
MAY DEVELOP.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...HARD FREEZE WARNING SUNDAY
MORNING FOR AZZ502-504>506.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1101 PM CST FRI DEC 25 2015
.UPDATE...
ISSUED AT 845 PM CST FRI DEC 25 2015
Surface high pressure located well north of our area will shift
slowly east overnight while high and mid level clouds increase
from the southwest ahead of our next weather system. Thunderstorms
that were occurring today along a stalled frontal boundary over
the southern Mississippi Valley have kept that boundary further
south than indicated by models yesterday at this time. Just what
affect, if any, that will have on the placement of the front
in southeast Illinois tomorrow remains to be seen, and that will
be the key to where the heavy rainfall sets up as a plume of deep
subtropical moisture, seen on our evening water vapor loop, streams
northeast into the region on Saturday into Saturday night. The 00z
ILX sounding showing quite a bit of dry air in place in the low
and mid levels of the atmosphere. The latest RAP model suggests
any rain on Saturday will hold off until dawn across southeast
Illinois, and over the remainder of our area by late morning.
Temperatures early this evening have dropped off quicker than
earlier thought so we had to make some adjustments to the overnight
lows. Based on the latest satellite trends, it appears with the
thicker cloud cover moving up from the southwest, we may have seen
our overnight lows reached in some areas already with a steady or
slowly rising trend late tonight. Should have the updated zones
out by 900 pm.
&&
.SHORT TERM...(Tonight)
ISSUED AT 333 PM CST FRI DEC 25 2015
Early afternoon surface map showing high pressure centered over
Wisconsin, providing a dry north/northeast flow into central
Illinois. Expansive area of stratus has extended southwest from the
high and did clip the far western CWA earlier this morning, but the
southern and eastern edges have eroded some. However, there has been
some diurnal type development a bit further to the south. Most of
the forecast area has had a fairly nice day, with temperatures
reaching the mid 40s to lower 50s with a good deal of sunshine. The
far northwest corner was still below 40 degrees early this afternoon
due to the more extensive clouds.
Main focus for tonight will be with the timing of precipitation.
There has been quite a bit of convection this afternoon from
Louisiana northeast into eastern Tennessee, which is slowing the
northward push of the frontal boundary. Most of the morning models
generally bring the front into the southern tip of Illinois by
morning, as the southwest upper flow begins to sharpen with an upper
low forms over Arizona. Have maintained the chance PoP`s across the
far southeast CWA, as forecast soundings near Lawrenceville show a
nice moistening of the lower layers between midnight and 3 am. Areas
further north do not see this happening until closer to morning, so
have kept the forecast dry from about Rushville-Mattoon northward.
Temperatures will be relatively steady through the night.
.LONG TERM...(Saturday through Friday)
ISSUED AT 333 PM CST FRI DEC 25 2015
Several weather concerns over the next few days for central IL:
First, A major rain event continues to set up for central/SE IL and
surrounding areas. Two periods of heaviest rainfall appear likely at
this point. First will start Saturday morning south of I-70, spread
northward through the early afternoon encompassing much of the I-72
corridor, and continue into Sunday morning. A lull Sunday afternoon-
evening...then re-intensification Sunday night through Monday
afternoon. A flash flood watch is in effect from Saturday at noon to
Monday evening for areas from Scott County through Springfield to
Champaign county and areas south/eastward.
Second, thunderstorms with some severe potential Saturday afternoon
through Saturday night...mainly southeast of a Springfield to
Champaign line.
Third, potential for freezing rain Sunday night/Monday
morning...mainly north of I-72.
Synopsis...A frontal boundary will start the day near or south of
the Ohio River Saturday morning...lifting northward rapidly through
the day as strong southwesterly flow sets up ahead of a deepening
upper low over the Southwestern states. A plume of near 1.5 inch
precipitable water (near record for this time of year) will be
interacting with the warm frontal zone creating a plume of heavy
rain through central IL. Rainfall amounts of 2 to 3 inches can be
expected Saturday afternoon through Sunday morning from around
Springfield to Champaign southward through Flora and Lawrenceville.
Enough instability is indicated by model solutions for thunderstorms
in this area as well, and there will be enough shear for a concern
of severe storms...however instability is somewhat on the weak side.
The next feature will be a vigorous low ejecting out of the
Southwestern states...providing widespread lift by Sunday night and
another round of heavy precipitation...this time another 2 inches
across central IL. All told...4 to 6 inches possible I-72
southward...with 2 to 4 inches to the north by Tuesday morning.
The low track has trended somewhat northwest of previous runs at
this point...which diminishes the freezing rain and snow threat
somewhat through central IL For Monday/Monday night. Latest trends
would suggest freezing rain will be limited more toward areas north
of I-72 than previous runs as cold air would be confined to areas
farther northwest.
Temps will edge above freezing everywhere toward midday Monday,
resulting in a change over to all rain. Once the low tracks into
the southern Great Lakes, enough cold air will be pulled down behind
it to support a change over to snow or a rain/snow mix north of I-70
Monday night. Will need to keep an eye on this, as any eastward
deviation of the low track will lead to more snow and possible
accumulations across the area.
A break in precipitation is expected Wednesday, then another system
could bring some light precipitation...mainly snow...back late
wednesday into Wednesday night.
Temperatures quite mild Saturday with highs ranging from 46 in
Galesburg to 64 in Lawrencevile...then following a cooling trend
through midweek. Eventually...Highs should be near or slightly below
normal with highs ranging from the upper 20s to upper 30s by
Thursday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
ISSUED AT 1100 PM CST FRI DEC 25 2015
Timing of MVFR/IFR clouds and rain into the forecast area is the
main forecast concern this period. Once the rain and low cigs
arrive, they will be here thru Saturday night/Sunday morning.
Currently, the MVFR cigs were located south of I-70 but were
tracking to the north at 15-20 kts. Based on the present
movement, it appears the MVFR cigs will arrive at SPI and DEC
around 09z, CMI by 10z, BMI and PIA by 11-12z. The rain will
follow during the morning hours which will effectively moisten
the lower layers resulting in IFR/LIFR cigs by late morning
or early afternoon. Surface winds will continue from an easterly
direction at 10 to 15 kts overnight and turn more into a
southeast direction on Saturday at 10 to 15 kts before winds
back more into a northeast direction at 8 to 15 kts in the
01z-04z time frame.
&&
.ILX Watches/Warnings/Advisories...
Flash Flood Watch from Saturday afternoon through Monday
afternoon for ILZ044>046-049>057-061>063-066>068-071>073.
&&
$$
UPDATE...Smith
SHORT TERM...Geelhart
LONG TERM...Onton
AVIATION...Smith
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1147 PM CST FRI DEC 25 2015
.UPDATE:
Issued at 825 PM CST Fri Dec 25 2015
Very little change made to the forecast other than to tweak sky
cover. After examining the 00z NAM and most recent HRRR and RAP
versus current satellite and radar trends, we still anticipate the
currently pcpn echo-free radar to rapidly fill in for most of our
forecast area late tonight and Saturday morning, of which trends
were handled well by the previous forecast.
Temps will likely bottom out and hit their min values this evening
with a slow rise overnight as clouds thicken and dewpoints rise.
TES
&&
.SHORT TERM: (Through Late Tonight)
Issued at 335 PM CST Fri Dec 25 2015
Currently experiencing the calm before the storm across the CWA
with high pressure to our north bringing tranquil conditions and
above average temperatures. Main activity at this time is the
frontal boundary draped from the TN Valley into lower MS Valley.
All indications are that fall heights and surface pressure tonight
across the high Plains along with the eastward retreat of the
surface high to our north will allow for a sizable response in
the atmosphere. Low level flow above the boundary layer is
forecast to veer and strengthen, with a veering 30-40+ kt south-
southwesterly LLJ transporting anomalously deep moisture northward
into the area while the surface boundary gradually retreats
northward as well. Precipitation should develop in response
although it appears to be delayed until overnight. The best threat
appears to be after 08-09z when elevated showers and thunderstorms
are expected primarily south of I-70 across southern MO into SW
IL.
Glass
.LONG TERM: (Saturday through Next Friday)
Issued at 335 PM CST Fri Dec 25 2015
...Very Serious-High Impact and Potentially Historic Heavy Rain/Flood
Event Likely Saturday Afternoon into Monday...
High Points...
Confidence is growing and high at this point in time that a very
serious high-impact and potentially historic heavy rain/flood
event will occur in the Saturday night into Monday. This event
will feature life-threatening flash flooding on creeks/streams and
poor drainage areas, and major to historic flooding on area
rivers. The Meramec River is a huge concern.
Widespread area average storm total rainfall is now forecast in the
5-8 inch range across the southeast half of the CWA. The Bullseye
for heaviest rainfall would be late Saturday afternoon and Saturday
night with embedded convection/high rainfall rates and training,
however this will also be a prolonged event lasting well into
Monday. A flash flood watch is already in place and we have now
expanded it northward some to account for greater northward spread
of significant precipitation during the event.
Discussion...
The rapid evolution and expansion of a wide wsw-ene oriented band
of rain and thunderstorms is expected on Saturday along and north
of the lifting frontal zone. This will be in response to strong
deep layer ascent associated with a 40+ s/swly LLJ, disturbances
with the SW flow aloft and divergence aloft within the entrance
region of an anticyclonically curved ULJ. All the models have a
strong signal just differ some on the boundary location. Prefer
a blend of the GFS/ECMWF with this aspect and QPF placement with
the front near the I-44 corridor in MO and I-70 in IL at 00z
Sunday, feeling the NAM is too far north lifting the boundary
into cooler air.
The worst of this prolonged event appears to have a bullseye on
late Saturday afternoon into Saturday night. PWs are forecast to
exceed 1.5 inches which is 5 standard deviations above normal!
Strong deep layer ascent is focused in a broad region along and
north of the surface front resulting from frontogenesis, low level
MCON/lift, upper level disturbances and the ULJ entrance region.
This focused elongated forcing and flow aloft parallel to the
frontal zone favors training with elevated instability supporting
embedded convection. Along and south of the frontal zone there
could also be a few severe storms Saturday afternoon and evening.
The front then sags southeastward late Saturday night and this
will shift some of the focus of the axis of heaviest rainfall on
Sunday to the southeast third of the CWA. Finally late Sunday into
Monday will be the last aspect of the event as a strong closed upper
low and the associated vertically stacked system lifts north/northeast
through the MS Valley. This will lead a renewed northward spread
in rain, although rates appear lower with this round. While there
are differences in the system track, the most favored is a
western track which would largely keep any wintry precipitation at
bay to the west, with some chance of snow Monday night across
northeast and central MO in the cyclonic flow/CAA in the wake of
the departing system.
Glass
&&
.AVIATION: (For the 06z TAFs through 06z Saturday Night)
Issued at 1137 PM CST Fri Dec 25 2015
MVFR clouds will spread northward over the next 0-6 hours ahead of
an approaching low pressure system. This system will bring a
prolonged period of moderate/heavy rain along with reduced cigs
and vsbys, especially after 18z. Embedded thunderstorms are also
possible, especially between 18-22z when instability values are
highest. Rain will persist through the remainder of the valid TAF
period.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...Flash Flood Watch from Saturday afternoon through Monday
afternoon FOR Audrain MO-Boone MO-Callaway MO-Cole MO-
Crawford MO-Franklin MO-Gasconade MO-Iron MO-Jefferson MO-
Lincoln MO-Madison MO-Moniteau MO-Monroe MO-Montgomery MO-
Osage MO-Pike MO-Ralls MO-Reynolds MO-St. Charles MO-St.
Francois MO-St. Louis City MO-St. Louis MO-Ste. Genevieve
MO-Warren MO-Washington MO.
IL...Flash Flood Watch from Saturday afternoon through Monday
afternoon FOR Bond IL-Calhoun IL-Clinton IL-Fayette IL-
Greene IL-Jersey IL-Macoupin IL-Madison IL-Marion IL-Monroe
IL-Montgomery IL-Pike IL-Randolph IL-St. Clair IL-
Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
331 AM CST SAT DEC 26 2015
.SYNOPSIS...
ISSUED AT 330 AM CST SAT DEC 26 2015
LEAD PV ANOMALY FROM EVOLVING POSITIVELY TITLED LONG WAVE TROUGH
OVER THE WRN STATES MOVING QUICKLY NEWD THIS MORNING INTO WRN SD.
EARLIER LIGHTNING STRIKES ACROSS C NEB HAVE DISSIPATED ALTHOUGH
STILL SOME CONVECTIVE ELEMENTS SEEN IN RADAR ECHOES ACROSS ERN
NEB. IN RESPONSE PV DESTRUCTION INCREASING FROM KS INTO NEB AND
IA WHICH WILL EVENTUALLY CHANGE THE TILT OF THE TROUGH IN THE
NEXT 24-48 HRS. ULTIMATELY THE ONGOING WINTER STORM ACROSS THE
WRN PORTION OF THE STATE FIGHTING DRY AIR WHICH HAS HELPED THE
CONVECTIVE ELEMENT OF THE STORM...BUT DECREASED THE OVERALL
COVERAGE OF THE HEAVIEST SNOW TO SMALLER FRONTOGENETIC BANDS.
SNOW HAS MOSTLY ENDED ACROSS SWRN NEB WHILE WINDS PICKING UP
ALONG THE FRONT RANGE AND PLAINS OF CO AND NWD INTO WRN NEB AND
SERN WY INDICATIVE OF A BARRIER JET ON NWRN SIDE OF LOW PRESSURE
SYSTEM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CST SAT DEC 26 2015
HAVE ADJUSTED THE TIMING OF THE WINTER WEATHER ADVISORY TO END
EARLIER ALONG THE INTERSTATE 80 CORRIDOR AS RADAR ECHO TRENDS AND
SHORT RANGE MODELS SUGGEST NO NEW SNOW DEVELOPMENT EXPECTED AS
THE SYSTEM MOVES NEWD THIS MORNING. ALTHOUGH FRONTOGENESIS
REMAINS STRONG IN THE MID LEVELS FROM MN SWWD INTO C NEB...DRY
AIR AND LARGE SCALE SUBSIDENCE WILL OVERTAKE THE SRN END AND SHUT
OFF THE ACCUMULATING SNOW THIS AFTERNOON ACROSS ALL BUT NRN AREAS
OF THE STATE. MEANWHILE NRN STREAM SHORT WAVE DROPS QUICKLY SEWD
ACROSS THE NRN PLAINS WHICH WILL INCREASE THE SUBSIDENCE FURTHER
NWD LATER THIS AFTERNOON ENDING THE PRECIP FOR THE REMAINDER OF
THE AREA. AS THIS OCCURS...STRONG COLD FRONT WILL PUSH QUICKLY
SEWD ACROSS THE AREA THIS MORNING AND EARLY AFTERNOON. THIS FRONT
DOES ORIGINATE FROM POLAR REGIONS AND WILL DROP TEMPS THROUGHOUT
THE DAY. HIGHS IN MOST PLACES WILL BE REACHED BEFORE NOON AND
WITH THE INCREASING WIND WILL MAKE IT FEEL MUCH COLDER AND WIND
CHILLS BELOW ZERO CAN BE EXPECTED MOST AREAS BY LATE AFTERNOON.
SOME AREAS OF BLOWING SNOW AS WELL ACROSS THE N THIS AFTERNOON AS
WINDS PICK UP. SKIES SHOULD CLEAR MOST OF THE WAY BY EARLY SUNDAY
MORNING LEADING TO VERY COLD ACTUAL TEMPS ESPECIALLY WHERE A
DEEPER SNOW PACK EXISTS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 330 AM CST SAT DEC 26 2015
THE LONG TERM SUMMED UP...A COLD END TO 2015 CAN BE EXPECTED. A
SERIES OF LONG WAVE TROUGHS ACROSS THE HEART OF THE NATION TO
COMBINE WITH SNOWPACK ACROSS MUCH OF THE AREA RESULTING IN TEMPS
TO REMAIN WELL BELOW NORMAL. HIGHS GENERALLY IN THE TEENS AND 20S
WITH LOWS IN THE SINGLE DIGITS TO LOWER TEENS...LOCALLY A FEW
NIGHTS COULD SEE TEMPS DIP BELOW ZERO.
AN UPPER LEVEL LOW WILL TRACK ACROSS THE SOUTHERN ROCKIES SUNDAY
THEN LIFT NORTHEAST ACROSS THE PLAINS EARLY IN THE WEEK. THE GFS
CONTINUES TO BE THE FURTHEST EAST WITH THE TRACK...WHILE THE NAM
IS THE FURTHEST TO THE WEST. THE FORECAST CONTINUES TO FOLLOW A
BLEND...WHICH IS CLOSE TO THE TRACK FROM THE ECMWF. THIS RESULTS
IN SOME WRAP AROUND MOISTURE MAKING IT INTO THE CWA MONDAY INTO
MONDAY NIGHT...AND COULD LINGER INTO EARLY TUESDAY. THE TRACK
FAVORS THE HIGHEST PRECIP TO THE SOUTHEAST OF THE CWA...AND WOULD
NOT BE SURPRISE IF ONLY THE FAR EASTERN ZONES MANAGED TO MEASURE.
A CLIPPER QUICKLY FOLLOWS FOR TUESDAY INTO TUESDAY NIGHT. MOISTURE
IS LIMITED AND TOP DOWN SATURATION WILL LIMIT PRECIP REACHING THE
GROUND...THUS WILL KEEP POPS LOW.
ANOTHER CLIPPER FOR WEDNESDAY NIGHT INTO THURSDAY. MODELS ARE IN
AGREEMENT WITH LESS MOISTURE TO WORK WITH AND FORECAST WILL REMAIN
DRY AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1129 PM CST FRI DEC 25 2015
IFR/LOCAL LIFR IN SNOW AND LOW CIGS IS EXPECTED TONIGHT THROUGH
15Z SATURDAY...MAINLY NORTH OF INTERSTATE 80 TO THE SD BORDER.
MVFR/VFR CIGS ARE EXPECTED SATURDAY FROM 18Z ONWARD. THE MVFR IS
MOST LIKELY ALONG AND NORTH OF HIGHWAY 20.
MVFR/VFR CIGS ARE EXPECTED SATURDAY EVENING THROUGH 06Z.
CONFIDENCE IS GOOD AND THE RAP AND NAM MODELS WERE THE BASIS FOR
THE FORECAST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 PM CST /5 PM MST/ THIS EVENING FOR
NEZ004>007-094.
WINTER WEATHER ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NEZ056-057-059.
WINTER WEATHER ADVISORY UNTIL 6 PM CST /5 PM MST/ THIS EVENING
FOR NEZ008>010-022>029-035>038.
&&
$$
SYNOPSIS...STOPPKOTTE
SHORT TERM...STOPPKOTTE
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1130 PM CST FRI DEC 25 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 258 PM CST FRI DEC 25 2015
STORM SYSTEM TO AFFECT THE AREA IS ON TRACK FOR TONIGHT INTO
SATURDAY. LATE THIS AFTERNOON...WATER VAPOR IMAGERY INDICATES THE PV
ANOMALY LOCATED OVER GRAND JUNCTION IN WESTERN COLORADO. MODELS
AGREE THAT THE ANOMALY WILL MOVE EAST-NORTHEAST INTO WESTERN
NEBRASKA THIS EVENING. A STRONG JET STREAK WILL MOVE NORTHEAST
ACROSS KANSAS INTO EASTERN NEBRASKA AHEAD OF THE SYSTEM TONIGHT. A
CROSS SECTION FROM NORTHWEST TO SOUTHEAST ACROSS THE REGION SHOWS A
CLASSIC AGEOSTROPHIC RESPONSE AS THE JET STREAK MOVES ACROSS...WITH
DEEP LIFT ACROSS MOST OF THE AREA. CONCERNS WITH SATURATION IN THE
MID LEVELS OF THE ATMOSPHERE ACROSS SOUTHWEST INTO PORTIONS OF
CENTRAL NEBRASKA...BUT THAT WILL NOT BE AN ISSUE ACROSS THE
PANHANDLE INTO NORTH CENTRAL NEBRASKA.
SNOW SHOULD INCREASE RAPIDLY ACROSS THE PANHANDLE INTO NORTH CENTRAL
NEBRASKA TONIGHT...AND CURRENT HEADLINES FOR WINTER WEATHER ADVISORY
AND WINTER STORM WARNING LOOK GOOD. DID EXPAND THE WARNING INTO BOYD
COUNTY...BUT OTHERWISE NO CHANGES.
AS MENTIONED MID LEVEL DRY AIR WILL ADVECT INTO SOUTHWEST AND
CENTRAL NEBRASKA...SO NOT EXPECTING AS MUCH SNOW IN THESE AREAS.
COULD HAVE SOME LIGHT FREEZING DRIZZLE HOWEVER.
SATURDAY MORNING A STRONG ARCTIC COLD FRONT WILL MOVE SOUTH THROUGH
THE AREA. H850MB WINDS INCREASE THROUGH THE DAY TO AROUND 45 KTS BY
AFTERNOON. BLOWING SNOW WILL LIKELY BE AN ISSUE ACROSS NORTH CENTRAL
NEBRASKA AND INTO THE PANHANDLE...AS NORTH WIND GUSTS OVER 30 MPH
ARE LIKELY. OTHERWISE FALLING TEMPERATURES THROUGH THE TEENS
EXPECTED.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 258 PM CST FRI DEC 25 2015
VERY COLD TEMPERATURES ARE LIKELY BY SUNDAY MORNING WITH LOWS IN THE
SINGLE DIGITS ABOVE ZERO CENTRAL AND SOUTHWEST NEBRASKA AND THE
SINGLE DIGITS BELOW ZERO IN THE NORTHERN SANDHILLS AND THE NEBRASKA
PANHANDLE. COMPARABLE TEMPERATURES ARE EXPECTED AGAIN SUNDAY NIGHT
AND EARLY MONDAY.
THERE IS STILL CONSIDERABLE UNCERTAINTY REGARDING THE IMPACT OF THE
MONDAY-TUESDAY SYSTEM ON CENTRAL AND WESTERN NEBRASKA. THE NAM12 IS
ABOUT 4 DEGREES LONGITUDE FARTHER WEST THAN THE GFS40 WITH THE TRACK
OF THE CYCLONE. THIS DIFFERENCE IS SIGNIFICANT WITH THE MORE
WESTERLY TRACK GIVING ISENTROPIC UPGLIDE OVER THE COLD DOME REACHING
THE NEBRASKA SANDHILLS WHILE THE MORE EASTERLY TRACK LEAVING CENTRAL
AND WESTERN NEBRASKA OUT OF THE PRECIPITATION COMPLETELY. ACCOUNTING
FOR THE UNCERTAINTY...WE WILL KEEP THE PROBABILITY LOW. AGAIN...
SIGNIFICANT DIFFERENCES IN THE EXTENDED SOLUTIONS CONTINUE EVEN
THROUGH TUESDAY NIGHT. THE ECMWF TAKES THE CYCLONE ALMOST DUE NORTH
INTO NORTHERN IOWA BEFORE TURNING IT EAST. AS A RESULT...SOME CHANCE
OF SNOWFALL WILL CONTINUE UNTIL TUESDAY EVENING IN NORTHERN
NEBRASKA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1129 PM CST FRI DEC 25 2015
IFR/LOCAL LIFR IN SNOW AND LOW CIGS IS EXPECTED TONIGHT THROUGH
15Z SATURDAY...MAINLY NORTH OF INTERSTATE 80 TO THE SD BORDER.
MVFR/VFR CIGS ARE EXPECTED SATURDAY FROM 18Z ONWARD. THE MVFR IS
MOST LIKELY ALONG AND NORTH OF HIGHWAY 20.
MVFR/VFR CIGS ARE EXPECTED SATURDAY EVENING THROUGH 06Z.
CONFIDENCE IS GOOD AND THE RAP AND NAM MODELS WERE THE BASIS FOR
THE FORECAST.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 PM CST /5 PM MST/ SATURDAY FOR
NEZ004>007-094.
WINTER WEATHER ADVISORY UNTIL 6 PM CST /5 PM MST/ SATURDAY FOR
NEZ008>010-022>029-035>038-056-057-059.
&&
$$
SHORT TERM...TAYLOR
LONG TERM...SPRINGER
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1134 PM CST FRI DEC 25 2015
.UPDATE...
FOR 06Z AVIATION DISCUSSION.
&&
.DISCUSSION...
WARM FRONT CONTINUES TO MOVE SLOWLY NORTHWARD ACROSS MIDDLE
TENNESSEE, WITH NASHVILLE STILL NORTH OF THE BOUNDARY. THE ONLY
PRECIPITATION SHOWING UP ON RADAR IS LOCATED ALONG THE PLATEAU,
ALTHOUGH THE HRRR SHOWS SOME RE-DEVELOPMENT AFTER MIDNIGHT WITH
THE PASSAGE OF THE WARM FRONT. WAS HOPING THE WARMER AIR MIGHT
LOWER RH VALUES AND REDUCE OUR CHANCE OF DENSE FOG, BUT DEW POINTS
ARE COMING RIGHT UP WITH THE TEMPS, SO DEW POINT SPREADS EVEN IN
THE WARM SECTOR ARE RUNNING ZERO OR CLOSE TO ZERO. HAVE ALREADY
INCLUDED PATCHY DENSE FOG IN THE GRIDS, AND WE WILL MONITOR IN
CASE AN ADVISORY IS NEEDED. HAVE MADE ADJUSTMENTS TO LOW TEMPS TO
COME MORE IN LINE WITH CURRENT OBS, AS TEMPS OVERNIGHT WILL LIKELY
INCREASE SLIGHTLY AS THE WARM FRONT LIFTS FARTHER NORTHWARD.
&&
.AVIATION...
06Z TAF DISCUSSION.
THE WARM FRONT IS SLOWLY WORKING NORTH ACROSS THE AREA. VIS
SHOULD IMPROVE SLOWLY OVERNIGHT FOR BNA AND INTO THE DAWN HOURS
FOR CKV AS THE FRONT SLIDES NORTH. WITH THE FRONT.. SOME
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE AROUND. CIGS SHOULD
IMPROVE TO MVFR FOR THE AFTERNOON AND EVENING HOURS AT ALL THREE
TERMINALS. WINDS WILL CONTINUE TO VEER FOR CKV AND BNA TO THE
SOUTH AND INCREASE TO THE 5-10 KT RANGE. CSV IS ALREADY SOUTH OF
THE BOUNDARY AND IS EXPERIENCING SOUTH WINDS AND VFR CIG AND VIS.
CSV VIS MAY DROP WITH A COUPLE PASSING SHOWERS AND THUNDERSTORMS
DURING THE MORNING HOURS.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH UNTIL 6 AM CST SATURDAY FOR BEDFORD-CANNON-CLAY-
COFFEE-CUMBERLAND-DAVIDSON-DE KALB-FENTRESS-GILES-GRUNDY-HICKMAN-
JACKSON-LAWRENCE-LEWIS-MACON-MARSHALL-MAURY-OVERTON-PERRY-
PICKETT-PUTNAM-RUTHERFORD-SMITH-TROUSDALE-VAN BUREN-WARREN-WAYNE-
WHITE-WILLIAMSON-WILSON.
&&
$$
SHORT TERM/AVIATION........10/REAGAN
LONG TERM..................08
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1149 PM EST FRI DEC 25 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL STALL OVER THE MID ATLANTIC REGION TONIGHT
AND LIFT NORTHWARD ON SATURDAY. SUNDAY AND MONDAY...A SERIES OF
STRONG LOW PRESSURE SYSTEMS WILL TRACK FROM THE SOUTHERN PLAINS TO
THE GREAT LAKES.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 1135 PM EST FRIDAY...
EXPECT A NARROW SLIVER OF SHOWERS FROM NE TN INTO THE FOOTHILLS OF
VA EARLY OVERNIGHT...WITH SOME INCREASE TOWARD MORNING OVER THE NC
MTNS AS BETTER UPPER DIVERGENCE ARRIVES. STILL LOOKS MOSTLY A
LIGHT TO AT TIMES MODERATE RAIN...WITH NEWER MODELS COMING IN
INDICATING BEST SLUG OF RAINFALL SATURDAY TO PUSH ACROSS ERN KY
INTO CENTRAL WV...SKIRTING THE SE WV MTNS. FOR THE REST OF THE
NIGHT CUT POPS BACK MORE AND LOWERED QPF.
PREVIOUS MID EVENING DISCUSSION...
CANCELLED THE FLASH FLOOD WATCH...AS HEAVIER RAIN THREAT HAS ENDED
AND DO NOT SEE ANY GOOD SIGNALS UPSTREAM FOR A NEAR TERM FLASH
FLOOD THREAT THROUGH TONIGHT. WILL HAVE TO WATCH OVER THE NC
MOUNTAINS IF SURGE OF MOISTURE WITH NEXT AREA OF UPPER DIVERGENCE
OVER GA/AL CAN GET ENHANCED OVERNIGHT. THINK THE RAIN WILL BE
MODERATE AT BEST...BUT IF TRENDS FOR DEEPER CONVECTION OCCUR
ANOTHER FLASH FLOOD WATCH WOULD BE NEEDED.
SAME GOES FOR SE WV INTO THE MOUNTAINS OF FAR SW VA FOR
SATURDAY...AS MODEL TRENDS GIVE THIS AREA ANOTHER ONE HALF TO ONE
INCH POTENTIALLY SATURDAY.
CUT BACK POPS OVERNIGHT FAVORING THE FAR SW VA/NW NC MTNS INTO SRN
VA AS HIGHER CORRIDOR OF RAINFALL CHANCES. FOG IS STILL LIKELY AS
SOME LOW LVL CLOUD COVER SCATTERS OUT ESPECIALLY OVER THE
GREENBRIER VALLEY INTO THE NEW RIVER VALLEY. ATTM...STILL NOT
SEEING ANY DECENT LOW VSBY COVERAGE FOR DENSE FOG ADVISORY OR
EVENT A STATEMENT.
PREVIOUS DISCUSSION FROM EARLY EVENING...
GOING TO CUT POPS BACK SOME OVER THE NW AS NARROW BAND OF SHOWERS
IS MAINLY LINED UP ALONG A ZONE OF LOW LVL CONVERGENCE FROM TRI-
BCB...EAST TO LYH. THE LATEST GFS PLUS HIGH-RES MODELS SHOWING
MORE OF A SWD SHIFT THROUGH THIS EVENING. WILL HAVE TO WATCH THE
DEEPER CONVECTION OVER MID TN EARLY THIS EVENING...AND SEE HOW IT
SHIFTS EAST OR NORTHEAST ALONG THE FRONTAL BOUNDARY.
STILL THINK FOG WILL BECOME AN ISSUE OVER THE WEST THROUGH
TONIGHT. WILL HAVE TO MONITOR HOW WIDESPREAD AND DENSE FOG
GETS...TO DECIDE BETWEEN A DENSE FOG ADVISORY VS SPECIAL WX
STATEMENT.
PREVIOUS AFTERNOON DISCUSSION...
A FRONTAL BOUNDARY WITH SEVERAL WAVES OF LOW PRESSURE STALLS THIS
EVENING INTO TONIGHT ACROSS THE REGION AND THEN PUSHES NORTHWARD ON
SATURDAY. AN AREA OF LOW PRESSURE IN WEST VIRGINIA THIS AFTERNOON
WILL LIFT NORTHEAST AND REACH THE JERSEY SHORE TONIGHT. A SECOND
AREA OF LOW PRESSURE WILL ROTATE NORTHWARD ALONG THE BOUNDARY
TONIGHT WITH ADDITIONAL SHOWERS. THE DAY 1 EXCESSIVE RAINFALL PLACED
THE WESTERN HALF OF THE FORECAST AREA UNDER A SLIGHT RISK. CURRENT
WSR-88D SHOWED A BAND OF SHOWERS AND THUNDERSTORMS FROM WEST
VIRGINIA SOUTHWARD TO EASTERN AND MIDDLE TENNESSEE. ELECTED TO
EXTEND OUR FLASH FLOOD WATCH UNTIL MIDNIGHT...GIVEN THAT WITH RECENT
RAINFALL AND LOW FFG...IT WILL NOT TAKE MUCH TO PRODUCE FLASH
FLOODING IN THE REGION. DAY ONE CONVECTIVE OUTLOOK STILL SHOWS A
MRGL THREAT FOR SEVERE...WITH THE POTENTIAL FOR LOCALLY STRONG WIND
GUSTS INTO THIS EVENING. MCS OVER EASTERN KENTUCKY/TENNESSEE IS
PROGGED TO SPREAD EAST OF THE BLUE RIDGE LATER TODAY...WHERE IT WILL
INTERACT WITH A SEASONABLY WARM AND MOIST AIR MASS. SEVERE THREAT
WILL BE HINDER BY POOR WEAK INSTABILITY...AND POOR LAPSE RATES OVER
OUR AREA. THE HIRESW-ARW...RNK WRF AND HRRR TAKE THE AREA OF
CONVECTION TO OUR WEST AND MOVED IT EASTWARD ACROSS OUR FORECAST
AREA THIS AFTERNOON INTO TONIGHT. THE GFS...NAM AND ECMWF DROP THE
CONVECTION WITH THE FRONTAL BOUNDARY SOUTH THROUGH 00Z TO 03Z THIS
EVENING. IN ANY CASE...PLAYED THE HIGHEST POPS ACROSS THE
NORTHWEST...WITH THE LOWEST ALONG THE EASTERN SLOPES OF THE
SOUTHERN BLUE RIDGE MOUNTAINS. IT WILL BE ANOTHER MILD
NIGHT...WITH LOW TEMPERATURES FROM THE LOWER 50S IN THE NORTHERN
MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT.
OUR UNSEASONABLY WARM AND UNSETTLED PATTERN WILL CONTINUE SATURDAY.
THE UPPER PATTERN WILL FEATURE AN EASTERN RIDGE AS A CLOSED LOW
DEVELOPS OVER TEXAS AND THEN EJECTS INTO THE OHIO VALLEY. THIS WILL
PUSH THE FRONTAL BOUNDARY...WHICH HAS BEEN WAVERING AROUND THE
REGION FOR THE LAST SEVERAL DAYS...BACK TO THE NORTH AND KEEP THE
BEST CHANCES FOR PRECIPITATION...MAINLY NORTH OF ROUTE 460. HIGH
TEMPERATURES SATURDAY WILL RANGE FROM THE LOWER 60S IN THE NORTHERN
MOUNTAINS TO LOWER AND MID 70S IN THE PIEDMONT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 130 PM EST FRIDAY...
RELATIVE BREAK IN THE WET WEATHER EXPECTED OVER THE BLACKSBURG
FORECAST AREA FROM SATURDAY NIGHT THROUGH AT LEAST EARLY SUNDAY
NIGHT WITH ONLY SPOTTY WARM SECTOR SHOWERS POSSIBLE AS VERY STRONG
TROPICAL RIDGE OF HIGH PRESSURE OFF THE SE COAST OF THE NATION
DEFLECTS NORTHERN STREAM ENERGY AND MORE ROBUST PRECIPITATION FIELDS
CLOSER TO BAROCLINIC ZONE TO THE NORTH OF THE AREA. ANY RESIDUAL
COOL WEDGE ACROSS NORTHEASTERN PORTION OF THE FORECAST AREA SHOULD
RETREAT NORTH AND OUT OF THE AREA BY OR SHORTLY AFTER DAYBREAK ON
SUNDAY AS SE COASTAL RIDGE STRENGTHENS.
HOWEVER...SITUATION WILL BEGIN TO CHANGE LATER SUNDAY NIGHT INTO
MONDAY AS YET ANOTHER...AND THIS TIME STRONGER NORTHERN STREAM WAVE
MOVES EAST THROUGH THE GREAT LAKES AND NEW ENGLAND...SUPPORTING
SOUTHEASTWARD PUSH OF COOLER HIGH PRESSURE INTO SOUTHEASTERN
CANADA...WHICH THEN RIDGES SOUTHWEST INTO THE MID ATLANTIC REGION
MONDAY AFTERNOON INTO MONDAY NIGHT. MEANWHILE...YET ANOTHER
FORMIDABLE LOW LATITUDE CLOSED LOW WILL DRIFT NORTHEAST ON THE
WESTERN PERIPHERY OF THE UPPER RIDGE ALONG THE SE COAST...GRADUALLY
LIFTING AND FILLING AS IT MOVES UP THROUGH THE MS/TN/OH VALLEYS.
APPROACH OF THE WESTERN SYSTEM...AND MOVEMENT OF COOL SURFACE HIGH
PRESSURE TO AN OFFSHORE POSITION TO OUR NORTHEAST WILL RESULT IN
SLOWLY VEERING LOWER TROPOSPHERIC WINDS BACK INTO AN UPSLOPE
COMPONENT ON MONDAY...WHICH SHOULD BEGIN THE NEXT ROUND OF
WIDESPREAD PRECIPITATION FOR THE REGION. PRECIPITATION WILL
INITIALLY BE CONFINED TO LIGHT RAIN AND DRIZZLE ACROSS THE EASTERN
FLANKS OF THE APPALACHIANS LATE SUNDAY NIGHT INTO EARLY MONDAY AS
UPSLOPE COMPONENT INCREASES...BUT THEN EXPAND TO A WIDESPREAD
COVERAGE ACROSS THE ENTIRE FORECAST AREA MONDAY AFTERNOON INTO
MONDAY NIGHT AS UPWARD VERTICAL MOTION FIELDS INTENSIFY AS A RESULT
OF INCREASING WARM MOIST ADVECTION AND APPROACH OF RIGHT ENTRANCE
REGION OF UPPER JET MAXIMA.
WITH GROUND CONDITIONS ALREADY SATURATED...AND WATER LEVELS IN AREA
STREAMS/CREEKS AND RIVERS ALREADY RUNNING HIGH FROM RECENT RAINS...
THREAT FOR ADDITIONAL FLOODING/FLASH FLOODING WILL AGAIN EXIST FROM
MONDAY AFTERNOON INTO MONDAY NIGHT UNTIL CHANGE OF AIRMASS OCCURS
WITH COLD FRONTAL PASSAGE LATE MONDAY NIGHT OR AROUND DAYBREAK ON
TUESDAY.
UNTIL THEN...TEMPERATURES THROUGH THE ENTIRE SHORT TERM PERIOD WILL
CONTINUE TO REMAIN CLOSE TO OR EXCEED RECORD LEVELS...BOTH FOR VERY
HIGH NIGHTTIME LOWS...WHICH WILL REMAIN NEARLY 30F ABOVE SEASONAL
NORMALS AND AROUND 15F HIGHER THAN WHAT WOULD NORMALLY BE EXPECTED
FOR A DAYTIME HIGH TEMPERATURE...WITH DAYTIME HIGH TEMPERATURES AT
LEAST 20F ABOVE SEASONAL NORMALS...AGAIN BREAKING RECORDS. REFER TO
CLIMATOLOGICAL SECTION FOR SPECIFICS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 140 PM EST FRIDAY...
TUESDAY WILL FEATURE SOME LEFT OVER RAIN SHOWERS BEFORE THE FRONT
CAN MAKE ITS PUSH THROUGH THE REGION. WEDNESDAY LOOKS TO BE A DRIER
DAY EARLY BEFORE THE NEXT SYSTEM MOVES UP AND BRINGS ADDITIONAL RAIN
SHOWERS LATE WEDNESDAY NIGHT AND INTO THE DAY ON THURSDAY. TEMPS
TUESDAY THROUGH THURSDAY WILL REMAIN ABOVE NORMAL. TUESDAY LOOKS TO
BE THE WARMEST DAY OF THE PERIOD WITH HIGHS IN THE UPPER 50S TO
LOWER 60S...AND THEN ABOUT 5 DEGREES COOLER ON WEDNESDAY AND
THURSDAY.
A BIG PATTERN SHIFT SETS UP FOR LATE IN THE WEEK AS A
STRONG RIDGE SETS UP OUT WEST AND A TROUGH BEGINS TO DIG IN ACROSS
THE EASTERN HALF OF THE COUNTRY BRINGING MUCH COLDER AIR TO THE
REGION. SEVERAL WAVES OF ENERGY WILL RIPPLE ACROSS THROUGH NEXT
WEEKEND. MOISTURE LOOKS LIMITED BUT COULD BE ENOUGH TO SQUEAK OUT
SOME NORTHWEST FLOW PRECIP ACROSS THE WESTERN UPSLOPE
AREAS...OTHERWISE THE REST OF THE REGION LOOKS TO BE COOLER AND DRY
FOR NEXT WEEKEND.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1143 PM EST FRIDAY...
EXPECT TO SEE A VARIABLE AVIATION FORECAST OVERNIGHT WITH SOME
LOCATIONS DROPPING TO IFR OR WORSE VSBYS AND/OR CIGS. RAIN SHOWERS
WILL BE LIMITED BUT THERE IS STILL PLENTY OF MOISTURE IN ALL
LEVELS AT TIMES. SOME BREAKS IN THE LOWER CLOUD COVER HAS ALLOWED
FOR DENSE FOG TO FORM AT LWB...WITH THINK BCB AND POTENTIALL ROA
TO LYH/DAN COULD DROP TO 1/2 TO 1SM EARLY IN THE MORNING.
BEST BET FOR RAIN SHOWER WILL BE IN THE LWB/BLF CORRIDOR SATURDAY
WITH SCATTERED THREAT FURTHER EAST. AS HIGH PRESSURE MOVES OVER
THE NORTHEAST IT WEDGES SOUTHWEST INTO THE MOUNTAINS...AND NOW THE
NAM/GFS INDICATE THAT MOST TAF SITES WILL NOT BREAK OUT OF LOW END
MVFR SATURDAY...SO WENT A LITTLE MORE PESSIMISTIC IN THE
TERMINALS.
CONFIDENCE IS HIGH THAT MOST...IF NOT ALL TAF SITES STAY MVFR OR
WORSE THIS PERIOD...THOUGH COULD SEE BLF GO VFR THROUGH THE
MORNING.
.EXTENDED AVIATION DISCUSSION...
THE CHANCE OF SHOWERS AND SUB-VFR CONDITIONS WILL CONTINUE INTO
SAT NIGHT ANS SUNDAY THOUGH SHOWERS WILL BE LIMITED. WE ARE LESS
LIKELY TO PERSIST IN THE IFR OR WORSE VALUES AS ATMOSPHERE WILL BE
A LITTLE BETTER MIXED AND FREQUENCY OF SHOWERS MUCH LESS WITH NO
KEY FEATURES TO HELP LIFT THE MOIST ATMOSPHERE.
BEYOND THIS WEEKEND...MODELS CONTINUE TO VARY BUT SHOWING BETTER
THREAT OF SHOWERS AGAIN BY LATE MONDAY INTO TUESDAY WITH VFR TO
IFR AT TIMES.
&&
.HYDROLOGY...
AS OF 1006 PM EST FRIDAY...
FLASH FLOOD WATCH CANCELLED...BUT STILL FLOOD WARNINGS ALONG THE
DAN RIVER AND AT RANDOLPH ON THE ROANOKE RIVER. THE CLINCH AND
NORTH FORK OF THE HOLSTON IN FAR SW VA ARE ALSO RISING BUT WITH
LACK OF APPRECIABLE RAIN THROUGH EARLY OVERNIGHT...THINK THESE
RIVERS STAY BELOW FLOOD STAGE.
&&
.CLIMATE...
AS OF 230 PM EST FRIDAY...
WITH THE CONTINUING VERY WARM AIRMASS IN PLACE FOR THE NEXT
SEVERAL DAYS... MANY DAILY MAX TEMPERATURE RECORDS AS WELL AS HIGH
MIN TEMPERATURE RECORDS ARE LIKELY TO BE SET. FOR REFERENCE...HERE
ARE RECORDS FOR OUR CLIMATE STATIONS FOR THE NEXT SEVERAL DAYS.
SATURDAY 12/26/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 62 1987 -3 1983 16 1977 55 1982
KDAN 75 1982 2 1983 18 1983 57 1964
KLYH 72 1922 1 1983 22 1914 58 1964
KROA 70 1964 3 1980 23 1985 56 1982
KRNK 64 1982 -8 1985 9 1983 50 1982
SUNDAY 12/27/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 69 2008 9 1977 20 2010 52 1982
KDAN 77 1982 6 1983 27 1985 54 1964
KLYH 71 1971 0 1914 21 1925 50 1940
KROA 69 1984 -3 1914 25 1935 52 1940
KRNK 67 2008 -6 1985 20 1985 52 1964
MONDAY 12/28/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 67 1984 4 1977 20 1995 53 1984
KDAN 72 1971 13 1966 28 1950 54 2008
KLYH 76 1984 6 1977 26 1950 51 1959
KROA 75 1984 4 1925 25 1925 51 1984
KRNK 66 1984 6 1977 28 1995 42 1959
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK/WP
SHORT TERM...WERT
LONG TERM...CF
AVIATION...AMS/KK/WP
HYDROLOGY...AMS/KK/WP
CLIMATE...AMS/RCS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
651 AM EST SAT DEC 26 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 552 AM EST SAT DEC 26 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A SRN STREAM TROF OVER THE
ROCKIES WITH SW FLOW DOWNSTREAM INTO THE UPPER GREAT LAKES. TO THE N
IN THE NRN STREAM...A BROADER TROF COVERS MUCH OF CANADA. TIGHTENING
CONFLUENT FLOW BTWN THE 2 BRANCHES IS SETTING UP A STRENGTHENING
UPPER JET IN THE VCNTY OF THE UPPER GREAT LAKES INTO SE CANADA.
MEANWHILE...SHORTWAVE FROM THE SRN STREAM TROF IS EJECTING NE ACROSS
THE WRN PLAINS. COMBINATION OF STRENGTHENING RIGHT ENTRANCE UPPER
JET FORCING AND EJECTING ENERGY HAS LED TO PCPN DEVELOPMENT FROM
NEBRASKA NE INTO ECNTRL MN.
INHERITED FCST IS GENERALLY ON TRACK...BUT SOME REFINEMENTS HAVE
BEEN NEEDED. STRENGTHENING FGEN IN RESPONSE TO STRENGTHENING UPPER
JET AND SHARPENING ISOTACH GRADIENT WILL SUPPORT CONTINUED SPREAD OF
PCPN NE INTO THE UPPER GREAT LAKES TODAY. THE MOST ACTIVE FGEN
RESPONSE/STRENGTHENING IS A BIT HIGHER INTO THE MID LEVELS THAN
TYPICALLY SEEN SO THE HEAVIER BAND OF SNOW WILL BE DISPLACED QUITE A
BIT FARTHER N OF THE SFC/850MB FRONT THAN ONE WOULD NORMALLY SEE.
BIGGEST CONCERN THIS MORNING IS LOW-LEVEL EASTERLY FLOW HOLDING IN
DRIER AIR AT THE LOW LEVELS ACROSS CNTRL AND ERN UPPER MI. MOST OF
THE 00Z HIGH RES MODEL GUIDANCE HAS MAINTAINED ENOUGH DRY AIR TO
SHIFT MAIN AREA OF SNOW A BIT W AND N OF WHAT WAS PREVIOUSLY
EXPECTED. HOURLY RAP/HRRR MODEL RUNS THRU THE NIGHT HAVE CONTINUED
TO MAINTAIN OR EVEN STRENGTHEN THE LOW LEVEL DRY AIR AS HAS THE 06Z
NAM. AS A RESULT...THIS MORNINGS FCST HAS TRENDED POPS/HEAVIEST SNOW
A BIT W AND N...RESULTING IN IRON COUNTY WINTER WX ADVY BEING
DROPPED. MARQUETTE COUNTY COULD SEE QUITE A GRADIENT FROM SE TO NW
TODAY...WITH POTENTIAL FOR AREAS S AND E OF MARQUETTE TO SEE LITTLE
OR NOTHING WHILE SEVERAL INCHES OF SNOW FALL N AND W OF NEGAUNEE.
FARTHER W AND NW...LOOKS LIKE A SOLID ADVY SNOWFALL TODAY OF 3-6
INCHES. BIGGEST CONCERN IS THE KEWEENAW WHERE SOME LAKE ENHANCEMENT
COULD OCCUR UNDER ENE LOW-LEVEL WINDS...POTENTIALLY REQUIRING
UPGRADING OF HEADLINE. WILL NEED TO MONITOR SNOW TRENDS AFTER
SYNOPTIC SNOW ARRIVES TO SEE WHERE OR IF ENHANCEMENT TAKES SHAPE.
LATE THIS AFTN/EVENING...PCPN SHOULD EXPAND ACROSS THE CNTRL AND ERN
FCST AREA AS A PUSH OF STRONGER ISENTROPIC ASCENT/MOISTURE ADVECTION
SHIFTS ACROSS THE AREA. PCPN DURATION SHOULD BE BRIEF ENOUGH TO
PRECLUDE ANY NEED FOR HEADLINES ACROSS THE SCNTRL/E WITH ONLY 1-2
INCHES OF SNOW. CLOSE TO LAKE MI IN MENOMINEE COUNTY...PCPN MAY MIX
WITH RAIN FOR A TIME. BACK TO WRN AND NCNTRL UPPER MI...SYNOPTIC
SNOW WILL WIND DOWN...BUT LAKE/UPSLOPE ENHANCEMENT SHOULD SUPPORT AS
MUCH AS 3-4 INCHES OF ADDITIONAL SNOW IN THE FAVORED HIGH TERRAIN
AREAS AS WINDS BACK FROM NE TO N.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 459 AM EST SAT DEC 26 2015
A SIGNIFICANT LARGE-SCALE PATTERN CHANGE WILL BE UNDERWAY AT THE
START OF THE FORECAST PERIOD AS DEEP TROUGHING DEVELOPS ACROSS THE
CENTRAL CONUS FOR THE UPCOMING WEEK.
SUNDAY...SHORTWAVE TROUGHING OVER THE UPPER MS VALLEY WILL BE
SHIFTING EASTWARD WHILE PHASING WITH A PIECE OF ENEGERY THAT EJECTED
FROM A CLOSED LOW OVER THE SW STATES. WITH SYNOPTIC MOISTURE FROM
TODAYS SYSTEM HAVING ALREADY DEPARTED...PRECIP WILL BE CONFINED TO
LES ALONG LAKE SUPERIOR. WITH INVERSIONS LOWERING TO UNDER 4KFT AND
DEEP DRY AIR ADVECTING ACROSS THE UPPER GREAT LAKES...DO NOT EXPECT
ANY INTENSE LES. RATHER...THE SHALLOW CLOUD MOSTLY LOCATED WITHIN
THE DGZ SUPPORTS PERIODS OF LIGHT TO INFREQUENTLY MODERATE FLUFFY
LES FOR MAINLY THE NW-WIND SNOW BELTS...ESPECIALLY EAST WHERE LOW-
LEVEL CONV IS ENHANCED BY A LINGERING LOW-LEVEL THERMALLY INDUCED
TROUGH OVER LAKE SUPERIOR.
SUNDAY NIGHT THROUGH TUESDAY...MODEL GUIDANCE HAS HAD SOME SERIOUS
STRUGGLES WITH HOW TO HANDLE THE CUTOFF LOW OVER THE SW STATES. 24
HOURS AGO...GUIDANCE WAS TRENDING TOWARD SENDING THE LOW WELL TO THE
SE. NOW...NEARLY THE WHOLE MODEL SUITE HAS SHIFTED WELL TO THE NW.
THE SFC LOW IS NOW PROGGED TO TRACK ACROSS THE UPPER GREAT LAKES
MONDAY NIGHT INTO TUESDAY MORNING.
AS THE SFC LOW APPROACHES...LES ALONG LAKE SUPERIOR WILL SHIFT TO
THE NE WIND BELTS BY DAYBREAK MONDAY...AND THE EAST WIND BELTS BY
MONDAY AFTERNOON. SIGNIFICANT LOW LEVEL DRYING ASSOCIATED WITH A
STRONG 1040 MB HIGH OVER ONTARIO WILL LIKELY LIMIT LES ACTIVITY TO
JUST SOME ISOLATED TO SCATTERED LIGHT SHOWERS.
THE BEST FORCING FROM COUPLED UPPER JET STREAKS AND MID-LEVEL Q-
VECTOR CONV ARE STILL FORECAST TO REMAIN SOUTHEAST OF THE CWA...BUT
A MODEST DEFORMATION BAND ON THE NW SIDE OF THE WILL HAVE THE
POTNETIAL TO BRING SEVERAL INCHES OF ACCUMULATING SNOW ACROSS THE
CWA MONDAY NIGHT INTO EARLY TUESDAY MORNING. THE AFFORMENTED DRY NE
FLOW OFF ONTARIO WILL LIKELY LIMIT SNOWFALL TOTALS...SO DO NOT SEE
ANYTHING MORE THAN AN ADVISORY-LEVEL SNOW AT THIS TIME.
EAST WINDS WILL QUICKLY INCREASE ON MONDAY WITH THE TIGHTENING
PRESSURE GRADIENT BETWEEN THE APPROACHING LOW AND ONTARIO HIGH.
EXPOSED LOCATIONS TO EAST WINDS ALONG THE GREAT LAKES AND HIGH
TERRAIN SHOULD EXPERIENCE FREQUENT GUSTS TO 35 MPH LATE IN THE
AFTERNOON AND WELL INTO MONDAY NIGHT.
WEDNESDAY THROUGH FRIDAY...A PAIR OF MID-LEVEL TROUGHS ARE SET TO
CROSS THE UPPER GREAT LAKES ON WEDNESDAY AND THURSDAY. WITH RATHER
BROAD FORCING AND LIMITED MOISTURE...NEITHER LOOK TO BRING MORE THAN
A COUPLE INCHES OF SNOW. LES FOR THE NW WIND SNOW BELTS THEN
DEVELOPS BEHIND THESE TROUGHS ON FRIDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 651 AM EST SAT DEC 26 2015
AREA OF SNOW SPREADING INTO THE UPPER GREAT LAKES WILL AFFECT
KIWD/KCMX MORE SO THAN KSAW TODAY. AT KIWD/KCMX...EXPECT CONDITIONS
TO DETERIORATE TO IFR THIS MORNING. NOT OUT OF THE QUESTION FOR LIFR
CONDITIONS TO DEVELOP AS WELL...ESPECIALLY AT KCMX WHERE EASTERLY
WIND MAY LAKE ENHANCE THE SNOW. AT KSAW...MVFR CONDITIONS SHOULD
PREVAIL TODAY WITH SOME -SN AT TIMES. TONIGHT...IFR CONDITIONS
SHOULD PERSIST AT KIWD/KCMX WITH KSAW ALSO FALLING TO IFR AS BACKING
WINDS LEAD TO UPSLOPING AND LAKE ENHANCEMENT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 552 AM EST SAT DEC 26 2015
E TO NE WINDS WILL INCREASE TODAY UNDER TIGHTENING PRES GRADIENT
BTWN HIGH PRES RIDGE LIFTING N INTO NRN ONTARIO AND LOW PRES TROF
ORGANIZING FROM THE SRN PLAINS TO THE LOWER LAKES. EXPECT WINDS OF
20-30KT OVER WRN LAKE SUPERIOR AND 15-25KT ACROSS THE E. WINDS WILL
DIMINISH A LITTLE TONIGHT BEFORE INCREASING AGAIN ON SUN...THIS TIME
OVER ERN LAKE SUPERIOR WHERE WINDS WILL REACH 20-30KT. HEADING INTO
MON/MON NIGHT...LATEST INDICATIONS ARE FOR A WEAKENING LOW PRES
SYSTEM TO LIFT INTO THE GREAT LAKES WHILE STRONG HIGH PRES RESIDES N
AND NE OF LAKE SUPERIOR. THIS SHOULD RESULT IN A PERIOD OF EASTERLY
GALES DEVELOPING MON/MON EVENING. WINDS WILL THEN DIMINISH TUE AND
BECOME LIGHT...MAINLY UNDER 15KT ON WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 10 AM EST SUNDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 10 AM EST /9 AM CST/ SUNDAY FOR
MIZ001>003-009-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KLUBER
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
552 AM EST SAT DEC 26 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 552 AM EST SAT DEC 26 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A SRN STREAM TROF OVER THE
ROCKIES WITH SW FLOW DOWNSTREAM INTO THE UPPER GREAT LAKES. TO THE N
IN THE NRN STREAM...A BROADER TROF COVERS MUCH OF CANADA. TIGHTENING
CONFLUENT FLOW BTWN THE 2 BRANCHES IS SETTING UP A STRENGTHENING
UPPER JET IN THE VCNTY OF THE UPPER GREAT LAKES INTO SE CANADA.
MEANWHILE...SHORTWAVE FROM THE SRN STREAM TROF IS EJECTING NE ACROSS
THE WRN PLAINS. COMBINATION OF STRENGTHENING RIGHT ENTRANCE UPPER
JET FORCING AND EJECTING ENERGY HAS LED TO PCPN DEVELOPMENT FROM
NEBRASKA NE INTO ECNTRL MN.
INHERITED FCST IS GENERALLY ON TRACK...BUT SOME REFINEMENTS HAVE
BEEN NEEDED. STRENGTHENING FGEN IN RESPONSE TO STRENGTHENING UPPER
JET AND SHARPENING ISOTACH GRADIENT WILL SUPPORT CONTINUED SPREAD OF
PCPN NE INTO THE UPPER GREAT LAKES TODAY. THE MOST ACTIVE FGEN
RESPONSE/STRENGTHENING IS A BIT HIGHER INTO THE MID LEVELS THAN
TYPICALLY SEEN SO THE HEAVIER BAND OF SNOW WILL BE DISPLACED QUITE A
BIT FARTHER N OF THE SFC/850MB FRONT THAN ONE WOULD NORMALLY SEE.
BIGGEST CONCERN THIS MORNING IS LOW-LEVEL EASTERLY FLOW HOLDING IN
DRIER AIR AT THE LOW LEVELS ACROSS CNTRL AND ERN UPPER MI. MOST OF
THE 00Z HIGH RES MODEL GUIDANCE HAS MAINTAINED ENOUGH DRY AIR TO
SHIFT MAIN AREA OF SNOW A BIT W AND N OF WHAT WAS PREVIOUSLY
EXPECTED. HOURLY RAP/HRRR MODEL RUNS THRU THE NIGHT HAVE CONTINUED
TO MAINTAIN OR EVEN STRENGTHEN THE LOW LEVEL DRY AIR AS HAS THE 06Z
NAM. AS A RESULT...THIS MORNINGS FCST HAS TRENDED POPS/HEAVIEST SNOW
A BIT W AND N...RESULTING IN IRON COUNTY WINTER WX ADVY BEING
DROPPED. MARQUETTE COUNTY COULD SEE QUITE A GRADIENT FROM SE TO NW
TODAY...WITH POTENTIAL FOR AREAS S AND E OF MARQUETTE TO SEE LITTLE
OR NOTHING WHILE SEVERAL INCHES OF SNOW FALL N AND W OF NEGAUNEE.
FARTHER W AND NW...LOOKS LIKE A SOLID ADVY SNOWFALL TODAY OF 3-6
INCHES. BIGGEST CONCERN IS THE KEWEENAW WHERE SOME LAKE ENHANCEMENT
COULD OCCUR UNDER ENE LOW-LEVEL WINDS...POTENTIALLY REQUIRING
UPGRADING OF HEADLINE. WILL NEED TO MONITOR SNOW TRENDS AFTER
SYNOPTIC SNOW ARRIVES TO SEE WHERE OR IF ENHANCEMENT TAKES SHAPE.
LATE THIS AFTN/EVENING...PCPN SHOULD EXPAND ACROSS THE CNTRL AND ERN
FCST AREA AS A PUSH OF STRONGER ISENTROPIC ASCENT/MOISTURE ADVECTION
SHIFTS ACROSS THE AREA. PCPN DURATION SHOULD BE BRIEF ENOUGH TO
PRECLUDE ANY NEED FOR HEADLINES ACROSS THE SCNTRL/E WITH ONLY 1-2
INCHES OF SNOW. CLOSE TO LAKE MI IN MENOMINEE COUNTY...PCPN MAY MIX
WITH RAIN FOR A TIME. BACK TO WRN AND NCNTRL UPPER MI...SYNOPTIC
SNOW WILL WIND DOWN...BUT LAKE/UPSLOPE ENHANCEMENT SHOULD SUPPORT AS
MUCH AS 3-4 INCHES OF ADDITIONAL SNOW IN THE FAVORED HIGH TERRAIN
AREAS AS WINDS BACK FROM NE TO N.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 459 AM EST SAT DEC 26 2015
A SIGNIFICANT LARGE-SCALE PATTERN CHANGE WILL BE UNDERWAY AT THE
START OF THE FORECAST PERIOD AS DEEP TROUGHING DEVELOPS ACROSS THE
CENTRAL CONUS FOR THE UPCOMING WEEK.
SUNDAY...SHORTWAVE TROUGHING OVER THE UPPER MS VALLEY WILL BE
SHIFTING EASTWARD WHILE PHASING WITH A PIECE OF ENEGERY THAT EJECTED
FROM A CLOSED LOW OVER THE SW STATES. WITH SYNOPTIC MOISTURE FROM
TODAYS SYSTEM HAVING ALREADY DEPARTED...PRECIP WILL BE CONFINED TO
LES ALONG LAKE SUPERIOR. WITH INVERSIONS LOWERING TO UNDER 4KFT AND
DEEP DRY AIR ADVECTING ACROSS THE UPPER GREAT LAKES...DO NOT EXPECT
ANY INTENSE LES. RATHER...THE SHALLOW CLOUD MOSTLY LOCATED WITHIN
THE DGZ SUPPORTS PERIODS OF LIGHT TO INFREQUENTLY MODERATE FLUFFY
LES FOR MAINLY THE NW-WIND SNOW BELTS...ESPECIALLY EAST WHERE LOW-
LEVEL CONV IS ENHANCED BY A LINGERING LOW-LEVEL THERMALLY INDUCED
TROUGH OVER LAKE SUPERIOR.
SUNDAY NIGHT THROUGH TUESDAY...MODEL GUIDANCE HAS HAD SOME SERIOUS
STRUGGLES WITH HOW TO HANDLE THE CUTOFF LOW OVER THE SW STATES. 24
HOURS AGO...GUIDANCE WAS TRENDING TOWARD SENDING THE LOW WELL TO THE
SE. NOW...NEARLY THE WHOLE MODEL SUITE HAS SHIFTED WELL TO THE NW.
THE SFC LOW IS NOW PROGGED TO TRACK ACROSS THE UPPER GREAT LAKES
MONDAY NIGHT INTO TUESDAY MORNING.
AS THE SFC LOW APPROACHES...LES ALONG LAKE SUPERIOR WILL SHIFT TO
THE NE WIND BELTS BY DAYBREAK MONDAY...AND THE EAST WIND BELTS BY
MONDAY AFTERNOON. SIGNIFICANT LOW LEVEL DRYING ASSOCIATED WITH A
STRONG 1040 MB HIGH OVER ONTARIO WILL LIKELY LIMIT LES ACTIVITY TO
JUST SOME ISOLATED TO SCATTERED LIGHT SHOWERS.
THE BEST FORCING FROM COUPLED UPPER JET STREAKS AND MID-LEVEL Q-
VECTOR CONV ARE STILL FORECAST TO REMAIN SOUTHEAST OF THE CWA...BUT
A MODEST DEFORMATION BAND ON THE NW SIDE OF THE WILL HAVE THE
POTNETIAL TO BRING SEVERAL INCHES OF ACCUMULATING SNOW ACROSS THE
CWA MONDAY NIGHT INTO EARLY TUESDAY MORNING. THE AFFORMENTED DRY NE
FLOW OFF ONTARIO WILL LIKELY LIMIT SNOWFALL TOTALS...SO DO NOT SEE
ANYTHING MORE THAN AN ADVISORY-LEVEL SNOW AT THIS TIME.
EAST WINDS WILL QUICKLY INCREASE ON MONDAY WITH THE TIGHTENING
PRESSURE GRADIENT BETWEEN THE APPROACHING LOW AND ONTARIO HIGH.
EXPOSED LOCATIONS TO EAST WINDS ALONG THE GREAT LAKES AND HIGH
TERRAIN SHOULD EXPERIENCE FREQUENT GUSTS TO 35 MPH LATE IN THE
AFTERNOON AND WELL INTO MONDAY NIGHT.
WEDNESDAY THROUGH FRIDAY...A PAIR OF MID-LEVEL TROUGHS ARE SET TO
CROSS THE UPPER GREAT LAKES ON WEDNESDAY AND THURSDAY. WITH RATHER
BROAD FORCING AND LIMITED MOISTURE...NEITHER LOOK TO BRING MORE THAN
A COUPLE INCHES OF SNOW. LES FOR THE NW WIND SNOW BELTS THEN
DEVELOPS BEHIND THESE TROUGHS ON FRIDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1210 AM EST SAT DEC 26 2015
MVFR CLOUDS AT ALL TAF SITES OVERNIGHT ARE EXPECTED TO LOWER TO
IFR/LIFR TODAY AS A BAND OF SNOW MOVES INTO THE AREA AND LAKE
ENHANCEMENT COMMENCES. NOT PRECISELY SURE WHERE HEAVIEST SNOW/LOWER
VIS WILL BE...BUT SHOULD SEE LOW CIGS/VIS AT ALL SITES...WITH THE
POTENTIAL FOR HEAVY SNOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 552 AM EST SAT DEC 26 2015
E TO NE WINDS WILL INCREASE TODAY UNDER TIGHTENING PRES GRADIENT
BTWN HIGH PRES RIDGE LIFTING N INTO NRN ONTARIO AND LOW PRES TROF
ORGANIZING FROM THE SRN PLAINS TO THE LOWER LAKES. EXPECT WINDS OF
20-30KT OVER WRN LAKE SUPERIOR AND 15-25KT ACROSS THE E. WINDS WILL
DIMINISH A LITTLE TONIGHT BEFORE INCREASING AGAIN ON SUN...THIS TIME
OVER ERN LAKE SUPERIOR WHERE WINDS WILL REACH 20-30KT. HEADING INTO
MON/MON NIGHT...LATEST INDICATIONS ARE FOR A WEAKENING LOW PRES
SYSTEM TO LIFT INTO THE GREAT LAKES WHILE STRONG HIGH PRES RESIDES N
AND NE OF LAKE SUPERIOR. THIS SHOULD RESULT IN A PERIOD OF EASTERLY
GALES DEVELOPING MON/MON EVENING. WINDS WILL THEN DIMINISH TUE AND
BECOME LIGHT...MAINLY UNDER 15KT ON WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 10 AM EST SUNDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 10 AM EST /9 AM CST/ SUNDAY FOR
MIZ001>003-009-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KLUBER
AVIATION...VOSS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
959 AM EST SAT DEC 26 2015
.SYNOPSIS...
A WARM FRONT WILL MOVE SLOWLY NORTHWARD THROUGH THE REGION TODAY
AND OVERNIGHT. SUNDAY LOOKS ANOTHER RECORD SETTING WARM DAY BEFORE
COLDER AIR MAKES A RETURN SUNDAY NIGHT INTO MONDAY.
A STORM DURING THE FIRST PART OF THE WORK WEEK COULD START OUT AS
A LIGHT WINTRY MIX OVER THE NORTHERN MOUNTAINS BEFORE CHANGING TO
BACK TO JUST RAIN BEFORE ENDING. TEMPERATURES WILL COOL OFF TO
NEAR NORMAL THROUGH THE REST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE RADAR SHOWS A DISORGANIZED AREA OF MAINLY LIGHT RAIN FROM THE
CENTRAL MOUNTAINS NORTH AND EAST. THE HRRR SHOWS THIS DISORGANIZED
ACTIVITY MORE OR LESS CONTINUING THROUGHOUT THE DAY BEFORE A
STEADIER AND MORE WIDESPREAD SHIELD OF RAIN SPREADS INTO THE
REGION AFTER DARK.
LOOK FOR AN UNSETTLED DAY WITH HIGHS GENERALLY IN THE 40S TO
LOWER 50S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
FRONT STAYS PRETTY MUCH STUCK TO THE SOUTH OF THE STATE UNTIL
LATER AT NIGHT WHEN IT COULD SLIDE THRU THE WRN MTNS AND THE SE.
HAVE PAINTED NEAR STEADY/RISING TEMPS FOR THE LATTER HALF OF THE
NIGHT THERE. THE AIRMASS WILL ONCE AGAIN HAVE THE POTENTIAL TO
PRODUCE RECORD MAXES - ESP CONSIDERING THE LOW-HANGING FRUIT OF
52F AT IPT AND 59F AT MDT FOR CURRENT RECORD MAXES ON THE 27TH.
HAVE PAINTED MAXES WELL ABOVE THE CURRENT RECORDS. BUST POTENTIAL
LIES IN HOW MUCH CLOUD COVER AND WHEN ANY RAIN SHOWERS DROP DOWN
FROM THE NW. SPEAKING OF POPS/WX...THE FRONT DOES NOT GO
FAR...STOPPING ABOUT LAKE ERIE AND A WAVE RIDES NE ALONG IT ON
SUNDAY/NIGHT. THIS WAVE SHOVES THE COLDER AIRMASS IN FROM THE WEST
SUNDAY NIGHT. BUT MINS WILL REMAIN 10-15F ABOVE NORMALS.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
MON-DAY WILL BE QUITE CHILLY - BUT VERY NEARLY NORMAL - AS TEMPS
GO LITTLE UPWARD THROUGH THE DAY. NORTH WINDS WILL BRING IN SOME
DECENTLY COLD AIR FROM A LARGE HIGH PRESSURE AREA MOVING ACROSS
CANADA AND INTO NEW ENGLAND. THE COLD AIR IS THE MOST INTERESTING
CHALLENGE IN THIS FORECAST...AND MAYBE FOR THE NEXT WEEK-PLUS. HOW
DEEP THE COLD AIR CAN GET AND HOW PERSISTENT IT WILL BE AGAINST
THE WARM AIR ADVECTION FROM A VERY STRONG LOW PRESSURE AREA MOVING
UP FROM THE LOWER MS VALLEY. SE WINDS OF 40KTS AT 8H MONDAY WILL
INCREASE TO 60KTS AS THEY VEER TO COME FROM DUE SOUTH. THE
MOISTURE TRANSPORT RESULTS IN PWATS OF 3 STANDARD DEVIATIONS ABOVE
NORMAL...WHICH IS NOT MUCH COMPARED TO SUNDAY/S LOFTY VALUES.
HOWEVER...THE MOISTURE ROLLING OVERHEAD WILL LIKELY BE LIQUID
FALLING INTO THE SUB- FREEZING AIR IN THE LOWEST 2-4KFT.
THE TROUBLE WOULD BE RE-FROZEN/FREEZING PRECIP LATE IN THE DAY ON
MONDAY AND MONDAY NIGHT. THE COLDEST/DEEPEST COLD AIR WILL BE IN
THE NERN MTNS AND MAY GET TRAPPED IN CENTRAL PA. HOWEVER...THE
TEMP GUIDANCE AT THIS POINT IS SOLID WITH CONTINUITY AND KEEPS THE
SRN HALF OF THE AREA ABOVE FREEZING THROUGH THE PERIOD. THE RECORD
WARMTH OF RECENT TIMES AND WARM/WET GROUND WILL BE NEGATIVES TO
FREEZING RAIN. SREF MEMBER P-TYPES PAINT A HIGH LIKELIHOOD OF
SLEET VS. FZRA. IN THE PAST...FORECASTS OF IP HAVE BEEN OVERDONE
BY THE SREFS AND A GREAT UNCERTAINTY REMAINS AS TO WHAT THE P-TYPE
WILL BE AND HOW LONG IT COULD STAY SOMETHING OTHER THAN PLAIN
RAIN. WILL KEEP IT CLOSE TO THE GOING FCST...BUT MENTION LESS
FZRA. BY TUESDAY MORNING....THE TEMP PROFILES ARE ENTIRELY RAIN
SAVE FOR PERHAPS TIOGA CO. THE PRECIP DOES PASS THROUGH IN
12-15HRS. THE STORM DEVELOPS A SECONDARY LOW OVER MD/DE AND SHOULD
CUT THINGS OFF TUESDAY MORNING. HELD SOME CHC POPS THRU THE AFTN
TO ACCOUNT FOR TIMING UNCERTAINTY.
ANOTHER UPPER SHORT WAVE IS IN STORE FOR EARLY THU AND BRINGS
RAIN...THEN COLDER AIR FOR THE LATER PART OF THE WEEK. TEMPS
FINALLY GET COLD ENOUGH AND FLOW OUT OF THE W/NW TO GENERATE LOTS
OF LAKE EFFECT SNOW. LAKES TEMPS HAVE GOT TO BE MUCH ABOVE
NORMAL...WHICH SHOULD HELP GENERATE PLENTY OF INSTABILITY AND
MOISTURE FLUX. 8H TEMPS DROP INTO THE NEGATIVE DOUBLE-DIGITS FRI-
MON UNDER A VERY DEEP UPPER TROUGH.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
CONDITIONS WILL DETERIORATE FROM SW TO NE AS A SLOWLY ADVANCING
WARM FRONT APPROACHES FROM THE SOUTH. NORTHERN AND EASTERN
TERMINALS WILL REMAIN VFR INTO THE AFTERNOON BEFORE CONDITIONS
DROP THERE AS WELL.
OUTLOOK...
SUN...IFR/MVFR WITH PERIODS OF RAIN. IMPROVING CONDITIONS SE ON
SUN. LLWS.
MON...VFR WITH AREAS MVFR.
MON NIGHT...DETERIORATING CONDITIONS. RAIN DEVELOPING /POSSIBLY A
WINTRY MIX NORTH/. LLWS.
TUE...RAIN SHOWERS LIKELY. GENERALLY MVFR WITH SLOWLY IMPROVING
CONDITIONS.
WED...MVFR LIKELY NW. VFR SE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO/LA CORTE
SHORT TERM...DANGELO
LONG TERM...DANGELO/MARTIN
AVIATION...ROSS/LA CORTE
AREA FORECAST DISCUSSION
NWS TUCSON AZ
910 AM MST SAT DEC 26 2015
.SYNOPSIS...A COLD STORM SYSTEM WILL BRING SCATTERED SNOW SHOWERS
MAINLY NEAR THE NEW MEXICO BORDER INTO SUNDAY. EXPECT WIDESPREAD
FREEZING TEMPERATURES TONIGHT...WITH A HARD FREEZE WARNING FOR
PORTIONS OF PIMA COUNTY AND SOUTHERN PINAL COUNTY. SCATTERED VALLEY
RAIN AND MOUNTAIN SNOW SHOWERS WILL OCCUR MONDAY NIGHT INTO TUESDAY
AS ANOTHER SYSTEM MOVES ACROSS THE AREA. DRY CONDITIONS WITH A
WARMING TREND WILL THEN PREVAIL WEDNESDAY THROUGH FRIDAY.
&&
.DISCUSSION...IR/VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS
DEPICTED PARTLY CLOUDY TO CLOUDY SKIES FROM THE TUCSON METRO AREA
EASTWARD TO THE NEW MEXICO BORDER AT THIS TIME. CLEAR SKIES WERE
ONGOING ACROSS WRN/CENTRAL PIMA COUNTY AND SOUTH CENTRAL PINAL
COUNTY WEST-TO-NORTHWEST OF TUCSON. 26/12Z KTWC SOUNDING TOTAL
PRECIP WATER VALUE WAS ONLY 0.18 INCH...INDICATIVE OF A VERY DRY
ENVIRONMENT. HOWEVER...A NEARLY SATURATED LAYER WAS OBSERVED AROUND
700 MB. 26/12Z UPPER AIR PLOTS DEPICTED A DEEP TROUGH THAT EXTENDED
FROM THE NRN ROCKIES SOUTHWESTWARD INTO THE SWRN CONUS...AND A
541 DM LOW WAS ANALYZED OVER EAST CENTRAL ARIZONA NEAR SHOW LOW/
KSOW. MODERATE TO STRONG WLY/SWLY FLOW PREVAILED ABOVE 600 MB.
THE UPPER LOW WILL MOVE SEWD TO NEAR THE FAR SE ARIZONA/SW NEW
MEXICO BORDER LATE THIS AFTERNOON. THE UPPER LOW WILL THEN MOVE EWD
INTO WEST TEXAS BY MIDDAY SUN. 26/12Z NAM/GFS AND 2-3 HRRR SOLUTIONS
WERE VERY SIMILAR WITH DEPICTING MEASURABLE PRECIP TO OCCUR MAINLY
NEAR THE NEW MEXICO BORDER THRU SUN MORNING. THE BULK OF THIS PRECIP
SHOULD OCCUR IN THE FORM OF SNOW SHOWERS. HOWEVER...SNOW ACCUMS
WILL BE FAIRLY LIGHT...WITH A FEW VALLEY LOCALES PERHAPS POISED TO
RECEIVE AROUND ONE INCH...AND 3-6 INCHES OF SNOW MAY ACCUMULATE ABOVE
6500 FEET IN THE MOUNTAINS.
GUSTY NORTHWEST WINDS WILL ACCOMPANY THIS LOW PRESSURE SYSTEM THIS
AFTERNOON AND EVENING...ESPECIALLY FROM TUCSON EWD TO THE NEW MEXICO
BORDER. THE UPPER GILA RIVER VALLEY...INCLUDING SAFFORD...APPEARS TO
THE FAVORED AREA FOR THE STRONGEST WIND SPEEDS. BELIEVE THAT
WIDESPREAD AND LONG-LIVED WIND ADVISORY CRITERIA WILL NOT BE
MET...GIVEN THE PROGRESSIVELY DECREASED WIND SPEEDS PER 3-4 RECENT
MODEL SOLUTIONS.
HIGH TEMPS THIS AFTERNOON ARE FORECAST TO AVERAGE NEARLY 10-20 DEGS
BELOW NORMAL. LOW TEMPS TONIGHT WILL ALSO BE WELL BELOW NORMAL. A
HARD FREEZE WARNING IS IN EFFECT FROM MIDNIGHT TONIGHT TO 8 AM MST
SUNDAY FOR THE TUCSON METRO AREA...MUCH OF THE TOHONO O`ODHAM
NATION...AND SOUTH CENTRAL/SE PINAL COUNTY. PLEASE REFER TO AWIPS
PRODUCT PHXNPWTWC /WMO HEADER WWUS75 KTWC/ FOR ADDITIONAL
INFORMATION.
DRY CONDITIONS WILL PREVAIL SUN NIGHT AND MON AS A SHORTWAVE RIDGE
FLATTENS AND MOVES EAST OF THE AREA. THE NEXT UPPER LOW IS THEN
PROGGED TO MOVE EWD ACROSS NRN ARIZONA INTO NRN NEW MEXICO LATE MON
NIGHT INTO TUE. THIS SYSTEM WILL BRING ISOLATED TO SCATTERED VALLEY
RAIN/MOUNTAIN SNOW SHOWERS TO THE AREA. THE INHERITED OFFICIAL
FORECAST DEPICTS SNOW LEVELS OF 5000-6500 LATE MON EVENING TO FALL TO
AROUND 4000-5000 FEET MIDDAY TUE. RAINFALL/SNOWFALL AMOUNTS SHOULD BE
FAIRLY LIGHT GIVEN THE RAPID MOVEMENT OF THIS SYSTEM. DRY CONDITIONS
WITH A MODEST WARMING TREND WILL THEN PREVAIL WED-FRI IN RESPONSE TO
A STRONG HIGH PRESSURE RIDGE ADJACENT THE WEST COAST.
&&
.AVIATION...VALID THRU 27/18Z.
SCATTERED -SHSN WILL OCCUR MAINLY NEAR THE NEW MEXICO BORDER INTO
SUNDAY MORNING. EXPECT OCCASIONAL MVFR CONDITIONS AND PERHAPS IFR
CONDITIONS DUE TO RESTRICTED CEILINGS AND VISIBILITIES. OTHERWISE...
CLEAR SKIES WILL PREVAIL WEST OF KTUS THRU THE PERIOD. KTUS VICINITY
EASTWARD...CLOUD BASES WILL MOSTLY RANGE FROM 8K-12K FT MSL. SURFACE
WIND THIS AFTERNOON AND EVENING WILL BE NWLY 12-25 KTS WITH GUSTS TO
AROUND 35 KTS. THE STRONGEST SPEEDS WILL BE NE OF KTUS NEAR KSAD.
THEREAFTER...SURFACE WIND WILL DIMINISH TO GENERALLY LESS THAN 10
KTS AND CONTINUE INTO SUNDAY MORNING. AVIATION DISCUSSION NOT
UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THERE IS A CHANCE OF SNOW SHOWERS MAINLY NEAR THE
NEW MEXICO BORDER INTO SUNDAY. SCATTERED VALLEY RAIN AND MOUNTAIN
SNOW SHOWERS WILL OCCUR MONDAY NIGHT INTO TUESDAY. OTHERWISE...
DRY CONDITIONS WILL PREVAIL DURING THE UPCOMING WORK WEEK.
EXPECT GUSTY NORTHWEST WINDS THIS AFTERNOON...AND ESPECIALLY IN THE
UPPER GILA VALLEY INCLUDING SAFFORD...WITH GUSTS OF 30-40 MPH
POSSIBLE. GENERALLY LIGHT TERRAIN DRIVEN WINDS WILL THEN PREVAIL
DURING MUCH OF THE UPCOMING WEEK. THE EXCEPTION IS NEXT FRIDAY WHEN
GUSTY EAST WINDS MAY DEVELOP.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
HARD FREEZE WARNING FROM MIDNIGHT TONIGHT TO 8 AM MST SUNDAY
FOR AZZ502-504>506.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
FRANCIS
AREA FORECAST DISCUSSION
NWS TAUNTON MA
333 PM EST SAT DEC 26 2015
.SYNOPSIS...
A STORM SYSTEM BRINGS PERIODS OF RAIN AND AREAS OF FOG TO THE
REGION LATE TONIGHT INTO SUNDAY. HIGH PRESSURE WILL BRING COLDER
AIR INTO THE REGION LATE SUNDAY NIGHT INTO MONDAY. A WINTRY MIX
FOR LATE MONDAY NIGHT ON INTO TUESDAY WHICH WILL POSE HAZARDS FOR
THE TUESDAY MORNING COMMUTE ESPECIALLY. PERHAPS A BRIEF REPRIEVE
PRIOR TO ANOTHER STORM SYSTEM THROUGH THE AREA ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
MAIN ISSUE IS TIMING OF PRECIPITATION ONSET. LATEST HRRR HAS RAIN
APPROACHING THE CT RIVER VALLEY AROUND 06Z. ALTHOUGH THERE COULD BE
SPRINKLES PRIOR TO THAT TIME...IT WILL TAKE A WHILE TO OVERCOME DRY
AIR BELOW THE CLOUD BASE AND SATURATE THE COLUMN. BELIEVE THE
MEASURABLE RAIN WILL REACH THE E COAST AROUND OR SHORTLY AFTER 08Z.
THICKENING CLOUDS SHOULD LIMIT RADIATIONAL COOLING. COULD SEE TEMPS
REACH DOWN AT MOST INTO THE MID 30S IN A FEW SPOTS ACROSS FRANKLIN
AND NW WORCESTER COUNTIES...AND DO NOT PERCEIVE A FREEZING RAIN RISK
TONIGHT. FEEL CONFIDENT IN CATEGORICAL POPS FOR LATE TONIGHT.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
SUNDAY...MOST OF FORECAST AREA SHOULD START OUT WITH RAIN FALLING
BUT PRECIPITATION SHOULD TAPER OFF TO SCATTERED SHOWERS OR PATCHY
DRIZZLE BY AFTERNOON. COLUMN STAYS QUITE MOIST ACROSS NORTHERN ZONES
BUT POSSIBILITY OF A FEW BREAKS OF SUNSHINE S OF THE MASS PIKE.
ANOMALOUSLY WARM AIR MASS BUT THINK CLOUDS WILL PROBABLY HOLD MAX
TEMPS IN THE LOW TO MID 50S ACROSS NORTHERN MA. ACROSS CT...RI AND
SE MA...MAY SEE TEMPS JUMP INTO THE LOWER 60S DURING THE
AFTERNOON...AND HI TEMP RECORDS IN PROVIDENCE AND HARTFORD HAVE
A CHANCE OF BEING REACHED OR EXCEEDED.
SUNDAY NIGHT...GOOD MODEL CONSISTENCY OF COLD FRONT PASSING THROUGH
SOUTHERN NEW ENGLAND IN THE EARLY EVENING...FOLLOWED BY CLEARING AND
STEADILY DROPPING TEMPERATURES AND DEWPOINTS OVERNIGHT. N WIND
SHOULD GIVE NOTICEABLE BRISK FEEL TO THE AIR.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
*/ HIGHLIGHTS ...
- WINTRY MIX BEGINNING AFTER MIDNIGHT TUESDAY AND THROUGH THE DAY
- ADVISORY LEVEL SNOWS N OF THE MASS-PIKE FAVORED
- INTERIOR MIX-OVER TO SLEET AND FREEZING RAIN
- MIX-OVER FROM SNOW TO RAIN ALONG THE SHORES
*/ OVERVIEW ...
MAJORITY OF DISCUSSION FOCUSED ON THE EARLY WEEK PERIOD EVALUATING
UPON MULTIPLE PIECES OF FORECAST GUIDANCE: ENSEMBLE PROBABILITIES
AND THREATS / CIPS ANALOGS / DETERMINISTIC TRENDS AND OUTPUT.
INTANGIBLES TO CONSIDER WHICH WILL LIKELY RESULT IN AN INDIRECT
MEASURE OF IMPACT OF THE STORM ITSELF: PROLONGED PERIOD OF 2-MONTHS
OF WELL-ABOVE AVERAGE TEMPERATURES / WATERS WARMER THAN NORMAL THAT
REQUIRE A LOT OF LATENT HEAT RELEASE TO FALL AT OR BELOW FREEZING /
2-5 CM SOIL TEMPERATURES AROUND THE UPPER 40S TO LOW 50S / A COASTAL
FRONT SETUP BETWEEN N INTERIOR AGEOSTROPHIC-ISALLOBARIC FLOW AGAINST
ONSHORE E-FLOW / ABSENCE OF ICE ALOFT TOWARDS THE END OF THE STORM
AS DRIER AIR WORKS IN ALOFT / PRECIPITATION INTENSITY / WET-BULB
TEMPERATURES.
LOOKING LIKE A SOLID ADVISORY-LEVEL EVENT. MAIN CONCERNS: ELEVATED
SURFACES /I.E. BRIDGES/ WHICH ARE FIRST TO FREEZE AS WELL AS IMPACTS
TAKING PLACE DURING THE TUESDAY MORNING COMMUTE AND LINGERING INTO
THE AFTERNOON AND EVENING.
OVERALL ... FORGET ABOUT ACCUMULATIONS AND WHAT IS GOING TO HAPPEN
IN YOUR BACKYARD SPECIFICALLY. FOCUS ON THE IMPACTS AND TRENDS ...
THE TIMING OF ASSOCIATED HAZARDS. IT TAKES ONLY A TRACE OF SNOW
AND/OR ICE TO MAKE ROADS SLICK. ADDITIONAL AMOUNTS ONLY MAGNIFY THE
MAGNITUDE OF THE IMPACT ... BUT THE THREAT TO LIFE AND PROPERTY IS
MOSTLY THE SAME WITH RESPECT TO THIS EVENT ... ESPECIALLY ALONG AREA
ROADWAYS.
WILL EXTEND ON FORECAST THINKING / SPECIFICS IN THE DISCUSSION BELOW.
*/ DISCUSSION ...
MONDAY ...
QUIET WITH COLD AIR IN PLACE PER 1040 CANADIAN HIGH PRESSURE TO THE
N. N-WINDS DRIVING COLDER AIR S. INCREASING CLOUDS THROUGH THE DAY
LOWERING AND THICKENING WITH TIME. DRY FORECAST. COOLER THAN AVERAGE
DAY ... FINALLY A TOUCH OF WINTER ... WITH HIGHS AROUND THE MID-30S.
MONDAY NIGHT INTO TUESDAY NIGHT ...
BROADSCALE OVER-RUNNING EVENT. FORCING / LIFT OF AVAILABLE MOISTURE
IS NOT OUT OF THE QUESTION AS THE THERMAL PROFILE TRANSITIONS FROM
COLD TO WARM ... AND SHALLOW SURFACE COLD AIR IS GRADUALLY SCOURED
OUT ... A LIKELY WINTRY MESS BEGINNING AFTER MIDNIGHT AND THROUGH
THE DAY TUESDAY.
NAM APPEARS THE OUTLIER. HOLDING COLDER AIR IN LONGER WITHIN THE LOW-
TO MID-LEVELS WHILE HOLDING DRIER AIR TO THE W KEEPING ICE PRESENT
THROUGH MUCH OF THE DAY TUESDAY ... WHEREAS THE GFS/EC TRANSITION
DURING THE MORNING PERIOD AND ICE BECOMES ABSENT AROUND MID-MORNING.
SIMILAR TRENDS OBSERVED WITH SURFACE 2M TEMPERATURES AND DEWPOINTS
WITH THE NAM HOLDING COLDER AND DRIER AIR IN LONGER OVER THE GFS/EC.
DOES NOT MAKE ABSOLUTE SENSE CONSIDERING THE CANADIAN HIGH SHIFTING
E AND THE LIKELY VEERING OF AGEOSTROPHIC FLOW OUT OF THE E AS WELL
OFF THE WARMER OCEAN WATERS.
THIS MAY ALL BE DUE TO THE VARIABILITY OF THE STRENGTH AND EVOLUTION
OF N-AND S-STREAM LOW CENTERS. NAM APPEARS MORE STOUT WHEREAS THE
GFS/EC DEAMPLIFIES THE H5 IMPULSE OUT OF THE SW-CONUS WHICH MAKES
MORE SENSE BASED ON THE BROADER-SCALE PATTERN AS OF LATE OF MORE
FAVORABLE RIDGING OVER THE E-CONUS. EVEN CONVERGENT LOW-LEVEL WIND
FIELDS DIFFER BETWEEN THE TWO CAMPS OF THE NAM AND GFS/EC.
WILL LEAN A GFS/EC BLEND WITH THIS FORECAST. TRANSITION THE LOW- TO
MID-LEVELS WARMER DURING THE MORNING WHILE USHERING DRIER AIR FROM
THE W. GRADUAL EROSION OF COLDER AIR AT THE SURFACE N/E AS A COASTAL
FRONT SETUP PUSHES N. THIS SUBSEQUENT AS THE AGEOSTROPHIC FLOW NEAR
THE SURFACE VEERS E OVER TIME ... ESPECIALLY WITH HEIGHT ... AS THE
CANADIAN HIGH SHIFTS TO THE E.
SO INITIAL SNOWS CHANGING TO SLEET DURING THE EARLY- TO MID-MORNING
SW TO NE ... THEN CHANGING OVER TO FREEZING RAIN ACROSS THE INTERIOR
FOR THOSE LOCALES BELOW FREEZING AS WARMER AIR INTRUDES ALOFT AND
ICE BECOMES ABSENT. MAY VERY WELL BE DURING THE INITIAL DEVELOPMENT
PHASE OF THE COASTAL FRONT THAT SHORE-LINE COMMUNITIES SIMPLY CHANGE
FROM SNOW TO RAIN. ALL LOCATIONS CHANGED OVER TO RAIN BY MID- TO
LATE-AFTERNOON.
EVALUATING PROBABILITIES ... ADVISORY-LEVEL SNOWS ARE FAVORED ALONG
AND N OF THE MASS-PIKE WITH A LOW-RISK OF WARNING LEVEL SNOWS OVER N
MASS. A DECENT SLEET POSSIBILITY WITH THE POTENTIAL FOR A PROLONGED
PERIOD OF FREEZING RAIN PERHAPS GREATER THAN 6-HOURS AS SUGGESTED
PER CIPS ANALOGS. WILL UPDATE OUR WINTER WEATHER WEBPAGE ACCORDINGLY.
NOT OVERLY CONFIDENT WITH THE SNOW- AND ICE-TOTAL OUTPUT ... FEEL
THERE IS GOING TO BE SOME FLUX OF LESSER TOTALS ALONG THE IMMEDIATE
E-COAST WITH BRISK ONSHORE FLOW. IN IS IN THESE AREAS THAT ALSO TOO
SNOW MAY SIMPLY CHANGE TO RAIN. AS WE GET HIGHER-RES GUIDANCE AND
CLOSER TO THE EVENT ... SHOULD HAVE A BETTER HANDLE OVERALL.
NO HAZARDS AT THIS TIME. CONTINUED MENTION IN THE HAZARDOUS WEATHER
OUTLOOK. PLEASE SEE THE OVERVIEW ABOVE FOR THE BROADER OVERVIEW OF
CONCERNS AND CHALLENGES TO THIS FORECAST.
WEDNESDAY THROUGH FRIDAY...
HIGH PRESSURE GIVES US A BREAK ON WEDNESDAY. THE NEXT SHORTWAVE
RACES THROUGH THE UPPER FLOW AND BRINGS PRECIPITATION OUR WAY
THURSDAY. LOW CONFIDENCE ON STORM TRACK...WITH TEMPERATURES
BORDERLINE FOR ICE INLAND...BUT MAINLY RAIN EXPECTED OVER OUR AREA.
DRY WEATHER RETURNS FOR FRIDAY.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SUNDAY NIGHT/...
TONIGHT...MODERATE TO HIGH CONFIDENCE. ANTICIPATING VFR CONDITIONS
TO PREVAIL MOST OF THE EVENING BUT STARTING TO DETERIORATE TOWARD
MIDNIGHT CT RIVER VALLEY AND THE EAST SLOPES OF THE BERKSHIRES. MVFR
CIGS AND VSBYS IN RAIN AND FOG WILL SPREAD EAST TO REACH THE MA EAST
COAST AROUND 08Z OR 09Z. AREAS OF IFR CIGS/VSBYS LIKELY DEVELOPING
TOWARD DAYBREAK FROM WEST TO EAST.
SUNDAY...MODERATE CONFIDENCE. WIDESPREAD IFR CIGS AND MVFR VSBYS
WITH AREAS OF IFR VSBYS IN RAIN AND FOG IN THE MORNING IMPROVING TO
MVFR OR LOW VFR CIGS IN THE AFTERNOON.
SUNDAY NIGHT...HIGH CONFIDENCE. AREAS OF MVFR CIGS LINGERING DURING
THE EVENING ACROSS CT...RI AND SE MA BUT BECOMING VFR OVERNIGHT.
KBOS TERMINAL...MODERATE TO HIGH CONFIDENCE IN TAF. VFR CONDITIONS SHOULD
PERSIST TO ABOUT 08Z AND THEN LOWERING TO MVFR CIGS/VSBYS AND LIKELY
IFR CIGS/VSBYS BY DABREAK IN RAIN AND FOG. IMPROVING TO MVFR OR LOW
VFR CIGS DURING THE AFTERNOON.
KBDL TERMINAL...MODERATE TO HIGH CONFIDENCE IN TAF. EXPECT VFR CONDITIONS
TO PREVAIL THROUGH ABOUT 05Z AND THEN DETERIORATING THEREAFTER AS
PER TAF.
OUTLOOK /MONDAY THROUGH THURSDAY/...
MONDAY ... HIGH CONFIDENCE.
VFR. BLUSTERY N-WINDS WITH GUSTS TO 25 KTS ALONG THE CAPE / ISLANDS
GRADUALLY VEERING NE.
MONDAY NIGHT INTO TUESDAY ... MODERATE CONFIDENCE.
MIX OF MVFR-VLIFR. SNOW TRANSITIONING TO SLEET / FREEZING RAIN SW TO
NE WITH A TRANSITION TO RAIN ALONG THE SHORES. SNOW / ICE ACCUM
LIKELY OVER INTERIOR TERMINALS. N-WINDS ACROSS THE INTERIOR WITH
BLUSTERY ONSHORE FLOW WITH GUSTS UP TO 30 KTS ALONG THE COAST.
BACKING NW LATE.
WEDNESDAY ... MODERATE CONFIDENCE.
VFR. LIGHT AND VARIABLE WINDS.
THURSDAY ... LOW CONFIDENCE.
ANOTHER STORM SETUP WITH A MIX OF MVFR-IFR CONDITIONS AND RAIN.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SUNDAY NIGHT/...MODERATE CONFIDENCE
MODERATE TO HIGH CONFIDENCE.
REST OF THIS AFTERNOON AND TONIGHT...SEAS HAVE FINALLY DROPPED BELOW
5 FEET AT BUOY 44018 BUT REMAINING 5 TO 7 FEET ACROSS NANTUCKET
SHOALS AS WELL AS THE WATERS S OF LONG ISLAND. WILL START THE SCA
HEADLINE FOR THE OUTER SOUTH COAST WATERS LATE THIS AFTERNOON TO
ACCOUNT FOR CURRENT CONDITIONS.
SUNDAY...SW GRADIENT STRENGTHENS ON SUNDAY AND WILL KEEP THE SCA
HEADLINE UP FOR THE BLOCK ISLAND AND RI SOUNDS.
SUNDAY NIGHT...N TO NNE WIND INCREASES BEHIND DEPARTING LOW AND COLD
FRONT. SURFACE GRADIENT COUPLED WITH MODERATELY STRONG COLD
ADVECTION WILL LIKELY RESULT IN WIND GUSTS 25 TO 30 KT ACROSS MOST
OF THE WATERS DEVELOPING SOMETIME SUNDAY NIGHT. THIS IS FAR ENOUGH
AHEAD AND SO WILL HOLD OFF ON HEADLINES FOR NOW BUT PROBABLY NEEDED
BEFORE TOO LONG. THERE IS A SMALL RISK BUT WITH CONFIDENCE BELOW 50
PERCENT OF GALE GUSTS TOWARD DAYBREAK MONDAY.
ADJUSTED STORM SURGE UP FROM GUIDANCE FOR MONDAY AM TIME FRAME
BUT NOT ENOUGH TO CAUSE ANY COASTAL FLOOD CONCERNS.
OUTLOOK /MONDAY THROUGH THURSDAY/...MODERATE CONFIDENCE.
MONDAY ... HIGH CONFIDENCE.
BLUSTERY N-WINDS WITH GUSTS TO 25 KTS ALONG THE CAPE / ISLANDS
GRADUALLY VEERING NE. SEAS OF AROUND 6-8 FEET MAINTAIN ON THE OUTER
WATERS AND ALONG THE NEAR-SHORES TO THE E.
MONDAY NIGHT INTO TUESDAY ... MODERATE CONFIDENCE.
SNOW TRANSITIONING TO RAIN SW TO NE. LIKELY VISIBILITY IMPACTS. E-
WINDS INCREASING AS LOW PRESSURE DEVELOPS ALONG THE NEAR-SHORE.
GUSTS UP TO 30 KTS POSSIBLE DURING THE DAY ... BACKING OUT OF THE NW
LATE. CHOPPY SEAS WITH N-SWELL AND E-WINDS. WAVES BUILD UP TO 10
FEET ON THE S-OUTER WATERS.
WEDNESDAY ... MODERATE CONFIDENCE.
LIGHT AND VARIABLE WINDS BENEATH HIGH PRESSURE. SEAS ALLOWED TO
RELAX.
THURSDAY ... LOW CONFIDENCE.
ANOTHER STORM SETUP WITH RAIN. WINDS COULD BECOME BLUSTERY LENDING
TO WAVE HEIGHTS BACK UP TO 5-FEET.
&&
.CLIMATE...
RECORD HIGH TEMPERATURES FOR SUNDAY 12/27...
BOSTON 61/1949
PROVIDENCE59/1973
HARTFORD60/1949
WORCESTER 58/1895
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST SUNDAY FOR ANZ254>256.
SMALL CRAFT ADVISORY FROM NOON TO 6 PM EST SUNDAY FOR ANZ235-
237.
&&
$$
SYNOPSIS...SIPPRELL/THOMPSON
NEAR TERM...THOMPSON
SHORT TERM...THOMPSON
LONG TERM...SIPPRELL/THOMPSON
AVIATION...SIPPRELL/THOMPSON
MARINE...SIPPRELL/THOMPSON
CLIMATE...
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
221 PM EST SAT DEC 26 2015
.NEAR TERM / THRU SUNDAY /...
MODEL GUIDANCE SUGGESTS LOW PROBABILITY OF SHOWERS LATE THIS
AFTERNOON AND EVENING SPREADING FROM S TO N. UNCERTAIN OF CAUSAL
MECHANISM FOR THE SHOWERS...WITH JUST GO WITH 20 POP INLAND AREAS
AND 30 POP COASTAL WATERS WHERE THERE ARE SOME WIDELY SCATTERED
SMALL SHOWERS.
ANOTHER CHALLENGING FORECAST OF LOW CLOUDS/FOG TONIGHT. HRRR NOT
AGGRESSIVE IN OUR FORECAST AREA...SREF SHOWING SOME POTENTIAL FOR
EASTERN SE GA COUNTIES WITH HIGHER PROBABILITIES OF LOW CLOUDINESS
ACROSS FORECAST AREA FROM I-10 NORTHWARD. MAY BE A LITTLE MORE IN
THE WAY OF WIND/MIXING JUST ABOVE THE SURFACE TO SUPPORT LOW
CLOUDS RATHER THAN DENSE FOG. FOR THIS FORECAST...WENT WITH
PATCHY FOG LATER TONIGHT...EXCEPT AREAS OF FOG ACROSS EASTERN HALF
OF OUR SE GA FORECAST AREA WHERE GREATER FOG POTENTIAL. ANOTHER
MILD NIGHT WITH LOW TEMPS IN THE MID TO UPPER 60S.
FOR SUNDAY...LOW CLOUDINESS AND PATCHY FOG IN THE MORNING SHOULD
GIVE WAY TO PARTLY CLOUDY SKIES WITH ANOTHER AFTERNOON OF NEAR
RECORD HIGH TEMPS...LOW-MID 80S INLAND...UPR 70S IMMEDIATE COAST.
.SHORT TERM...SUNDAY NIGHT THRU TUESDAY...SOUTHERN PLAINS LOW WILL
LIFT NE TO THE GREAT LAKES MONDAY NIGHT/TUESDAY WITH TRAILING COLD
FRONT STALLING JUST TO OUR NW. ISOLATED TO SCATTERED SHOWERS WILL BE
POSSIBLE OVER NE FL/SE GA AS MOISTURE INCREASES IN MID/UPPER LEVELS.
NEAR RECORD TEMPERATURES WILL PERSIST. HIGH HUMIDITY WILL ALSO
CONTINUE THE CHANCE FOR NIGHTLY FOG AND SEA FOG.
.LONG TERM...WEDNESDAY THROUGH SATURDAY...SURFACE FRONT WILL SHIFT
FURTHER NORTH OF THE AREA AS A LOW TO THE NW MOVES NE ALONG
BOUNDARY. AS SURFACE LOW AND UPPER TROUGH LIFT AWAY TO THE NE THE
FRONTAL BOUNDARY WILL SHIFT BACK TO THE SE REACHING SE GA LATE
THURSDAY. ADDITIONAL SHORT WAVE ENERGY WILL CARVE OUT A LONG WAVE
TROUGH OVER THE EAST THROUGH THE WEEKEND. THIS WILL ALLOW THE SLOW
MOVING COLD FRONT ACCOMPANIED BY SCATTERED TO NUMEROUS SHOWERS TO
MOVE ACROSS NE FL THURSDAY NIGHT BRINGING COOLER TEMPERATURES.
ABOVE NORMAL TEMPERATURES WEDNESDAY AND THURSDAY WILL COOL TO NEAR
AVERAGE LEVELS FOR THE NEW YEAR. POST FRONTAL RAIN WILL END FROM THE
NW BY FRIDAY NIGHT AS SHALLOW COLD FRONT SHIFTS SOUTH INTO S FL.
&&
.AVIATION...GENERALLY VFR CONDITIONS THROUGH EARLY EVENING. LATEST
MODEL GUIDANCE CONTINUES TO POINT TO DECENT POTENTIAL FOR LOW CIGS
TO DEVELOP BY LATE EVENING AND OVERNIGHT OVER TAF SITES...WITH
POTENTIAL FOR DENSE FOG KSSI BUT BETTER POTENTIAL FOR LOW CIGS
THAN DENSE FOG AT OTHER TAF SITES. NEVERTHELESS STILL ANTICIPATE
IFR CONDITIONS AT TAF SITES ESP 06-14Z. IMPROVING CONDITIONS
AFTER 14Z SUNDAY.
&&
.MARINE...INCREASING PRESSURE GRADIENT OVER WATERS BETWEEN HIGH
PRESSURE WELL NE OF WATERS AND DEVELOPING STORM SYSTEM OVER THE
SOUTHERN PLAINS WILL SUPPORT INCREASING WINDS AND SEAS. WILL GO
WITH EXERCISE CAUTION TONIGHT OFFSHORE COMPONENT FOR WINDS
INCREASING TO 15 KTS AND 4-6 FT SEAS. LITTLE CHANGE EXPECTED
THRU THE MIDDLE OF NEXT WEEK WITH CONTINUED S TO SE WINDS OVER
THE WATERS.
RIP CURRENTS: MODERATE RISK THIS WEEKEND.
.CLIMATE...
RECORD WARM MINIMUM TEMPS FOR DECEMBER 26TH...
JAX...66/1941...GNV...66/1964...AMG...65/1964...SSI...61/1987
RECORD MAX TEMPS FOR DECEMBER 26TH...
JAX...83/1987...GNV...82/2008...AMG...79/1987...SSI...79/1971
RECORD WARM MINIMUM TEMPS FOR DECEMBER 27TH...
JAX...68/1942...GNV...66/1911...AMG...62/2008...SSI...63/1982
RECORD MAX TEMPS FOR DECEMBER 27TH...
JAX...81/2008...GNV...84/1942...AMG...80/1987...SSI...78/1971
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 66 82 64 82 / 20 10 10 40
SSI 65 77 61 75 / 30 10 40 30
JAX 67 83 67 81 / 20 10 20 30
SGJ 68 80 67 80 / 20 10 20 30
GNV 66 83 66 83 / 20 10 10 30
OCF 66 84 67 84 / 20 10 10 40
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
WOLF/ZIBURA/GUILLET
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
314 PM CST SAT DEC 26 2015
.UPDATE...
1108 AM CST
TSRA COVERAGE SEEMS TO BE ON A DOWNWARD TREND LATE THIS MORNING
AFTER A LITTLE MORE ACTIVITY SOUTH AND WEST THAN MIGHT HAVE BEEN
EXPECTED EARLIER TODAY. FOCUS FOR ADDITIONAL TSRA WILL SHIFT
WELL SOUTH OF THE CHICAGO METRO AREA MAINLY TO PORTIONS OF NW
INDIANA ALONG WITH THE ANTICIPATED AXIS OF HEAVIER RAINFALL. MAY
EVEN BE ABLE TO LOWER POPS IN NORTHERN PORTIONS OF THE AREA TOWARD
ROCKFORD AND THE WI LINE THIS AFTERNOON...OR CARRY JUST A MENTION
OF DRIZZLE. EVEN IN THE CHICAGO METRO AREA...DRIZZLE MIGHT BE THE
MAIN WEATHER TYPE THIS AFTERNOON AS THE LATEST AMDAR SOUNDINGS OUT
OF MDW ARE SHOWING JUST A RELATIVELY SHALLOW SATURATED LAYER TO
ABOUT 850 MB WITH DRY AIR ABOVE THAT. THIS ALSO CORRESPONDS TO
WHAT THE RAP IS SHOWING...WITH AN INCREASINGLY SHALLOW SATURATED
LAYER AS THE AFTERNOON PROGRESSES.
WINDS WILL RELAX THIS AFTERNOON AND TONIGHT BEFORE PICKING UP
CONSIDERABLY AGAIN TOMORROW MORNING.
LENNING
&&
.SHORT TERM...
411 AM CST
THROUGH TONIGHT...
FOCUS IS ON MODERATE TO LOCALLY HEAVY RAINFALL LATE THIS AFTERNOON
THROUGH TONIGHT.
DEEP UPPER LEVEL LOW PRESSURE CONTINUES TO STRENGTHEN OVER THE
DESTER SOUTHWEST...WITH STRONG AND UNSEASONABLY MOIST/WARM
ADVECTION OCCURRING OUT AHEAD OF THE LOW. SEVERAL COMPLEXES OF
THUNDERSTORMS ARE ONGOING IN THE WARM ADVECTIVE REGIME NORTH OF A
WARM FRONTAL BOUNDARY DRAPED FROM THE ARKLATEX REGION THEN
NORTHEAST INTO THE TENNESSEE VALLEY IN AN AREA OF ELEVATED MID
LEVEL LAPSE RATES. AN ADDITIONAL AREA OF PRECIPITATION IS
OCCURRING NORTH OF AN INVERTED SURFACE TROUGH.
THIS WARM/MOIST BOUNDARY CONTINUES TO ADVECT NORTHWARD THIS
MORNING WITH A PLUME OF NEAR RECORD PRECIPITABLE WATER VALUES.
WITH COOL NORTHEAST WINDS IN PLACE AHEAD ANCHORING THE LOW LEVEL
FRONTAL BOUNDARY TO OUR SOUTH WILL CREATE A RECIPE FOR LOW CLOUDS
TO OVERSPREAD THE AREA THIS MORNING...AS FORECAST SOUNDINGS
DEPICT RAPID SATURATION OF THE LOWER LEVELS WHICH HAS BEEN
OCCURRING DOWNSTATE. AS CLOUDS LOWER...EXPECT SOME FOG TO DEVELOP
AS WELL.
THE INVERTED TROUGH AXIS SHIFTS AND IS POINTED AT OUR AREA AROUND
MIDDAY. AS THIS OCCURS IN CONJUNCTION WITH ISENTROPIC
ASCENT...EXPECT AN INCREASE IN INITIALLY LIGHTER RAIN SHOWERS THIS
MORNING DUE TO LACK OF DEEPER SATURATION...THEN AS FORCING
INCREASES AHEAD OF A NORTHERN STREAM SHORTWAVE...STRENGTHENING
UPPER LEVEL JET MAXIMUM TO OUR NORTHWEST...AND A STRONG LOW TO MID
LEVEL FRONTOGENESIS OCCURRING DUE TO THE AIRMASS CLASH...EXPECT
SHOWERS TO BLOSSOM THIS AFTERNOON AND EVENING. PRECIPITATION MAY
DWINDLE TO LIGHTER RAIN/DRIZZLE FARTHER NORTH...BUT THERE ARE
ADDITIONAL WAVES THAT WILL RIDE ALONG THE LOW AND ELEVATED
BAROCLINIC ZONES TO KEEP A MENTION OF RAIN GOING AREA-WIDE TONIGHT.
THE FRONT LOOKS TO BE MOST ACTIVE ALONG OUR SOUTHERN COUNTIES
WHERE EXTREME FRONTOGENESIS COMBINED WITH THE RECORD PWATS WILL
LEAD TO PERIODS OF MODERATE TO HEAVY RAINFALL. THUNDER IS
CERTAINLY POSSIBLE EVEN AS FAR NORTH AS CHICAGO OR LAKE MICHIGAN
AS THE PLUME OF ELEVATED LAPSE RATES SPREADS OVERHEAD...BUT MORE
LIKELY FARTHER SOUTH CLOSER TO THE STRONGER COMBINED FORCING.
THERE LOOKS TO BE A VERY TIGHT GRADIENT IN THE HEAVY PRECIP AXIS.
HAVE ELECTED TO ISSUE A FLOOD WATCH SIMILAR TO OUR NEIGHBORS DUE
TO THIS POTENTIAL GIVEN THE CONVECTIVE ELEMENTS PRESENT. THERE IS
STILL WITH SOME UNCERTAINTY AS TO IF THIS WILL REMAIN SOUTH OF THE
AREA AS SUGGESTED BY SOME HI-RES GUIDANCE MEMBERS. HAVE CARRIED
THIS WATCH OUT THROUGH THE SECOND EVENT (LONG TERM)...THOUGH THERE
WILL BE A GAP ON SUNDAY. MORE ON THIS IN THE HYDROLOGY SECTION
FORTHCOMING.
KMD
&&
.LONG TERM...
SUNDAY NIGHT THROUGH SATURDAY...
314 PM...FORECAST FOCUS AND CHALLENGE REMAINS FREEZING RAIN AND
ICE ACCUMULATIONS MONDAY ALONG WITH VERY STRONG WINDS AND LAKE
SHORE FLOODING POTENTIAL.
STRONG LOW PRESSURE OVER THE ARKLATEX SUNDAY EVENING WILL MOVE NORTH
TO NORTHWEST IL OR NORTHEAST IA MONDAY NIGHT. GUIDANCE IS SLOWLY
CONVERGING ON THIS TRACK THOUGH SPEED OF THE LOW HAS SLOWED JUST A
BIT...WHICH WILL DELAY THE ONSET OF PRECIP UNTIL AFTER MIDNIGHT
SUNDAY NIGHT/EARLY MONDAY MORNING.
TEMPERATURES WILL START IN THE MID 30S SUNDAY EVENING AND SLOWLY
DROP INTO THE UPPER 20S NORTHWEST TO NEAR FREEZING FROM THE CHICAGO
LAKEFRONT INTO THE SOUTHERN CWA. AS PRECIP BEGINS TO FALL EARLY
MONDAY MORNING...EXPECT A SHORT PERIOD OF MAINLY SLEET...POSSIBLY
MIXED WITH SOME SNOW...BEFORE CHANGING TO MAINLY RAIN/FREEZING RAIN.
TEMPS WILL SLOWLY RISE ABOVE FREEZING FROM SOUTH TO NORTH MONDAY...
TRANSITIONING PRECIP OVER TO JUST RAIN AND HAVE SPED UP THIS CHANGE
OVER TO RAIN JUST A BIT IN THE GRIDS.
THE MAIN QUESTION IS HOW MUCH QPF WILL BE FALLING WHILE TEMPS ARE
STILL AT OR BELOW FREEZING AND CAN THE STRONG EASTERLY WINDS KEEP
ENOUGH COLDER/DRIER AIR ADVECTING IN UNDER THE FALLING PRECIP TO
KEEP IT COLD ENOUGH FOR SIGNIFICANT ICE ACCUMULATIONS. ITS GOING TO
BE A BATTLE BETWEEN THE WARMER AIR SPREADING NORTH ALONG WITH WARMER
RAIN FALLING VS THE COLDER AIR ADVECTING IN. IN ADDITION...TEMPS
ALONG THE LAKE MICHIGAN SHORE AND SOME DISTANCE INLAND...MAY REMAIN
AT OR ABOVE FREEZING. HAVE MAINTAINED ICE AMOUNTS MAINLY IN THE 0.1
TO 0.2 INCH RANGE. THERE IS SOME POTENTIAL FOR HIGHER AMOUNTS MAINLY
ACROSS FAR NORTHERN IL AND NORTHWEST IL. WITH THESE AMOUNTS...AND
GIVEN THE UNCERTAINTY OF HOW LONG PRECIP CAN REMAIN FREEZING
RAIN...HAVE OPTED TO ISSUE A WINTER STORM WATCH FOR PART OF THE
NORTHERN CWA. AN ADVISORY WILL LIKELY BE NEEDED SOUTH OF THE WATCH
AREA AS THE EVENT NEARS.
AS THE PRECIPITATION CHANGES OVER TO RAIN...THERE COULD BE ANOTHER
PERIOD OF MODERATE RAINFALL. TOTAL QPF FOR THIS EVENT FROM EARLY
MONDAY MORNING THROUGH EARLY TUESDAY MORNING IS LIKELY TO BE IN THE
1 TO 1.5 INCH RANGE...THUS THIS COULD CAUSE ADDITIONAL RISES ON
ALREADY HIGH/ELEVATED RIVER LEVELS.
AS THIS LOW APPROACHES SUNDAY NIGHT INTO MONDAY...THE GRADIENT WILL
RAPIDLY TIGHTEN WITH VERY STRONG EASTERLY WINDS DEVELOPING.
CURRENTLY HAVE WIND GUSTS 40-45 MPH MONDAY BUT ITS POSSIBLE WINDS
GUSTS MAY BE AS HIGH AS 50 TO 55 MPH...ESPECIALLY ACROSS NORTHERN IL
AND ALONG THE LAKE FRONT. NO HEADLINES FOR THESE WINDS YET EITHER...
BUT WIND ADVISORY CRITERIA IS CERTAINLY POSSIBLE. THIS LOW WILL
BEGIN TO WEAKEN MONDAY NIGHT AS IT LIFTS NORTH OF THE CWA...THUS
WINDS ARE EXPECTED TO QUICKLY DIMINISH MONDAY EVENING.
THESE STRONG EASTERLY WINDS WILL PILE UP THE WAVES ALONG THE IL LAKE
MICHIGAN SHORE AND ITS POSSIBLE WAVES MAY REACH 14 TO 18 FEET...
ESPECIALLY NORTH OF NORTHERLY ISLAND AND WILL BE ISSUING A LAKE
SHORE FLOOD WATCH FOR COOK AND LAKE COUNTIES IN IL FROM MONDAY
MORNING THROUGH MONDAY EVENING.
A WEAK SYSTEM WILL MOVE ACROSS THE UPPER MIDWEST/GREAT LAKES REGION
WEDNESDAY INTO WEDNESDAY NIGHT WITH A PERIOD OF LIGHT SNOW POSSIBLE
ACROSS PARTS OF THE AREA...MAYBE MIXED WITH A LITTLE LIGHT RAIN.
COLDER AIR THEN SPREADS ACROSS THE REGION THURSDAY AND FRIDAY. CMS
&&
.HYDROLOGY...
RAIN DEVELOPING ALONG A STATIONARY FRONT DURING THE DAY
TODAY...AND POSSIBLY HEAVY AT TIMES LATE THIS AFTERNOON TONIGHT...IS
LIKELY TO PERSIST THROUGH EARLY SUNDAY MORNING. THUNDERSTORMS
ALSO ARE POSSIBLE ACROSS SOUTHERN PORTIONS OF THE AREA MAINLY
SOUTH OF THE KANKAKEE RIVER...WHERE WIDESPREAD 1.5 TO 2 INCH
RAINFALL AMOUNTS ARE MOST LIKELY. LOCALIZED AMOUNTS IN EXCESS OF 3
INCHES REMAIN POSSIBLE...THOUGH AT THIS TIME THIS MAY OCCUR JUST
SOUTH OF THE LOCAL AREA. REGARDLESS...THESE RAINFALL AMOUNTS MAY
RESULT IN SIGNIFICANT RISES AND POSSIBLE FLOODING ALONG AREA
RIVERS AND STREAMS...INCLUDING THE IROQUOIS AND KANKAKEE RIVERS AS
WELL AS SUGAR CREEK. IN ADDITION...THE HEAVY RAIN WILL LIKELY
RESULT IN SOME PONDING OF WATER IN LOW LYING AND POOR DRAINAGE
AREAS. SEE THE CURRENT FFALOT FOR MORE DETAILS. THIS APPEARS TO BE
MORE OF A FLOODING SITUATION THAN A TRUE FLASH FLOOD
SITUATION...BUT GIVEN THE CONVECTIVE ELEMENT TO THE PRECIPITATION
AND THE EFFICIENCY OF THE PRECIPITATION EXPECTED TONIGHT AND
SATURATED GROUND...FLOODING COULD OCCUR QUICKLY FOR AREAS STUCK
UNDER HEAVY RAINFALL. THE FLOOD WATCH FOR OUR SOUTHERN COUNTIES WILL
ALSO ACCOUNT FOR ANOTHER 1-1.5 INCHES OF RAINFALL EXPECTED ON
MONDAY.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* -RA/SHRA TRANSITIONING OVER TO DRIZZLE FOR THE REMAINDER OF THE
AFTERNOON THROUGH LATE TONIGHT...THOUGH A FEW LINGERING RAIN
SHOWERS WILL BE POSSIBLE THROUGH AROUND SUNSET. ANOTHER PERIOD
OF -RA LATE TONIGHT.
* IFR CIGS LIKELY THROUGH EARLY EVENING...THEN LIFR CIGS LIKELY
FOR THE LATE EVENING HOURS...BUT IMPROVING TO MVFR DURG THE LATE
NIGHT HOURS.
* EAST WINDS REMAIN ARND 5 TO 10 KT THROUGH LATE AFTERNOON
BACKING NNELY THIS EVENING. WINDS STRENGTHENING AND BECOMING
GUSTY TO ARND 25KT LATE TONIGHT AND TOMORROW.
KREIN
//DISCUSSION...UPDATED 18Z...
A MID LEVEL IMPULSE TRACKING ACROSS THE REGION HAS BROUGHT AN AREA
OF RAIN WITH MVFR CIGS/VIS AND OCNL IFR VIS IN HEAVIER SHOWERS.
SOME ISOLD EMBEDDED TS HAS BEEN OBSERVED WITHIN THE RAIN
AREA...BUT ANY TS HAVE REMAINED SOUTH AND EAST OF THE TERMINALS.
TS POTENTIAL SHOULD END BY 19-20Z AS THE IMPULSE MOVES OFF TO THE
NORTHEAST. MID LEVEL DRY AIR WILL OVERSPREAD THE REGION BEHIND THE
EXITING MID LEVEL IMPULSE...AND RAIN SHOULD TRANSITION OVER TO
DRIZZLE. WITH THE LOWER LEVELS REMAINING VERY MOIST...EXPECT THAT
CIGS/VIS SHOULD LOWER TO PREVAILING IFR BY SUNSET...WITH THE
POTENTIAL FOR LIFR CIGS OVERNIGHT. A MODEST PRESSURE GRADIENT
SHOULD KEEP NNELY WINDS OF 5-10KT THROUGH THE LATE NIGHT
HOURS...SO DO NOT EXPECT DENSE FOG TO FORM. DURG THE EARLY MORNING
HOURS...AS DEEPENING LOW PRESSURE LIFTS NORTHEAST OUT OF ERN
OKLAHOMA THROUGH MISSOURI TOMORROW...EXPECT A STRENGTHENING NNELY
PRESSURE GRADIENT...WITH WINDS GUSTING TO 25KT BY ARND 12Z
TOMORROW MORNING AND SUSTAINED WINDS AND GUSTS LIKELY INCREASING
THROUGH THE DAY TOMORROW AS THE LOW MOVES TO SERN IOWA LATE
TOMORROW AFTERNOON.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN PRECIP/VISBY TRENDS.
* HIGH CONFIDENCE IN IFR/LIFR CIGS...MEDIUM CONFIDENCE IN TIMING
OF IFR/LIFR CIGS.
* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...WINTRY MIX POSSIBLE LATE. MVFR CIGS PSBL.
MONDAY...WINTRY MIX TURNING TO RAIN. MVFR CIGS AND VSBYS.
TUESDAY...MVFR CIGS. CHANCE OF -SN/RA IN THE MORNING.
WEDNESDAY...MVFR CIGS. CHANCE OF -SN.
THURSDAY...MVFR CIGS.
FRIDAY...DRY. VFR.
KMD
&&
.MARINE...
213 PM CST
QUITE A FEW QUESTIONS FOR THE MARINE FORECAST OVER THE NEXT TWO OR
THREE DAYS. THE MAIN EVENT OF CONCERN WILL BE ON MONDAY WITH A PROLONGED
PERIOD OF NORTHEAST GALES...WITH POSSIBLE STORM FORCE GUSTS ACROSS THE
SOUTH HALF. AT THE PRESENT TIME A SMALL CRAFT ADVISORY IN EFFECT FOR
THE IL WATERS WILL BE EXTENDED THROUGH TOMORROW NIGHT...UP UNTIL THE
TIME OF THE GALES ON MONDAY. AN ADDITIONAL ADVISORY FOR THE INDIANA
WATERS WILL GO INTO EFFECT FOR THE SAME PERIOD STARTING THIS
EVENING. WINDS AND WAVES WILL BOTH BE A CONCERN. THERE ALSO IS A
CONCERN THAT LOW END GALES MAY DEVELOP FOR A TIME TOMORROW
AFTERNOON...BUT THIS WOULD BE MAINLY IN THE GUSTS AND NOWHERE
CLOSE TO THE STRENGTH OF WINDS ON MONDAY.
FOR MONDAY THERE WAS QUITE A BIT OF THOUGHT AND DISCUSSION ABOUT
GOING WITH A STORM WATCH ACROSS THE SOUTH HALF...BUT FOR NOW WILL
GO WITH A WATCH FOR HIGH END GALES AND JUST MENTION THE
POSSIBILITY OF OCCASIONAL STORM FORCE GUSTS ACROSS THE SOUTH HALF.
THIS MAY NEED TO BE UPGRADED AS THE EVENT APPROACHES.
AFTER THE EVENT TO START THE WEEK...WINDS DIMINISH AND TURN WEST
ON TUESDAY THEN GENERALLY MAINTAIN A WESTERLY COMPONENT FOR THE
REMAINDER OF THE WEEK.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ033-ILZ039 UNTIL 6 PM MONDAY.
LAKESHORE FLOOD WATCH...ILZ006-ILZ014...9 AM MONDAY TO 9 PM
MONDAY.
IN...FLASH FLOOD WATCH...INZ010-INZ011-INZ019 UNTIL 6 PM MONDAY.
LM...GALE WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...3 AM MONDAY TO 3 AM TUESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 3 AM MONDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 3 AM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
218 PM CST SAT DEC 26 2015
.UPDATE...
1108 AM CST
TSRA COVERAGE SEEMS TO BE ON A DOWNWARD TREND LATE THIS MORNING
AFTER A LITTLE MORE ACTIVITY SOUTH AND WEST THAN MIGHT HAVE BEEN
EXPECTED EARLIER TODAY. FOCUS FOR ADDITIONAL TSRA WILL SHIFT
WELL SOUTH OF THE CHICAGO METRO AREA MAINLY TO PORTIONS OF NW
INDIANA ALONG WITH THE ANTICIPATED AXIS OF HEAVIER RAINFALL. MAY
EVEN BE ABLE TO LOWER POPS IN NORTHERN PORTIONS OF THE AREA TOWARD
ROCKFORD AND THE WI LINE THIS AFTERNOON...OR CARRY JUST A MENTION
OF DRIZZLE. EVEN IN THE CHICAGO METRO AREA...DRIZZLE MIGHT BE THE
MAIN WEATHER TYPE THIS AFTERNOON AS THE LATEST AMDAR SOUNDINGS OUT
OF MDW ARE SHOWING JUST A RELATIVELY SHALLOW SATURATED LAYER TO
ABOUT 850 MB WITH DRY AIR ABOVE THAT. THIS ALSO CORRESPONDS TO
WHAT THE RAP IS SHOWING...WITH AN INCREASINGLY SHALLOW SATURATED
LAYER AS THE AFTERNOON PROGRESSES.
WINDS WILL RELAX THIS AFTERNOON AND TONIGHT BEFORE PICKING UP
CONSIDERABLY AGAIN TOMORROW MORNING.
LENNING
&&
.SHORT TERM...
411 AM CST
THROUGH TONIGHT...
FOCUS IS ON MODERATE TO LOCALLY HEAVY RAINFALL LATE THIS AFTERNOON
THROUGH TONIGHT.
DEEP UPPER LEVEL LOW PRESSURE CONTINUES TO STRENGTHEN OVER THE
DESTER SOUTHWEST...WITH STRONG AND UNSEASONABLY MOIST/WARM
ADVECTION OCCURRING OUT AHEAD OF THE LOW. SEVERAL COMPLEXES OF
THUNDERSTORMS ARE ONGOING IN THE WARM ADVECTIVE REGIME NORTH OF A
WARM FRONTAL BOUNDARY DRAPED FROM THE ARKLATEX REGION THEN
NORTHEAST INTO THE TENNESSEE VALLEY IN AN AREA OF ELEVATED MID
LEVEL LAPSE RATES. AN ADDITIONAL AREA OF PRECIPITATION IS
OCCURRING NORTH OF AN INVERTED SURFACE TROUGH.
THIS WARM/MOIST BOUNDARY CONTINUES TO ADVECT NORTHWARD THIS
MORNING WITH A PLUME OF NEAR RECORD PRECIPITABLE WATER VALUES.
WITH COOL NORTHEAST WINDS IN PLACE AHEAD ANCHORING THE LOW LEVEL
FRONTAL BOUNDARY TO OUR SOUTH WILL CREATE A RECIPE FOR LOW CLOUDS
TO OVERSPREAD THE AREA THIS MORNING...AS FORECAST SOUNDINGS
DEPICT RAPID SATURATION OF THE LOWER LEVELS WHICH HAS BEEN
OCCURRING DOWNSTATE. AS CLOUDS LOWER...EXPECT SOME FOG TO DEVELOP
AS WELL.
THE INVERTED TROUGH AXIS SHIFTS AND IS POINTED AT OUR AREA AROUND
MIDDAY. AS THIS OCCURS IN CONJUNCTION WITH ISENTROPIC
ASCENT...EXPECT AN INCREASE IN INITIALLY LIGHTER RAIN SHOWERS THIS
MORNING DUE TO LACK OF DEEPER SATURATION...THEN AS FORCING
INCREASES AHEAD OF A NORTHERN STREAM SHORTWAVE...STRENGTHENING
UPPER LEVEL JET MAXIMUM TO OUR NORTHWEST...AND A STRONG LOW TO MID
LEVEL FRONTOGENESIS OCCURRING DUE TO THE AIRMASS CLASH...EXPECT
SHOWERS TO BLOSSOM THIS AFTERNOON AND EVENING. PRECIPITATION MAY
DWINDLE TO LIGHTER RAIN/DRIZZLE FARTHER NORTH...BUT THERE ARE
ADDITIONAL WAVES THAT WILL RIDE ALONG THE LOW AND ELEVATED
BAROCLINIC ZONES TO KEEP A MENTION OF RAIN GOING AREA-WIDE TONIGHT.
THE FRONT LOOKS TO BE MOST ACTIVE ALONG OUR SOUTHERN COUNTIES
WHERE EXTREME FRONTOGENESIS COMBINED WITH THE RECORD PWATS WILL
LEAD TO PERIODS OF MODERATE TO HEAVY RAINFALL. THUNDER IS
CERTAINLY POSSIBLE EVEN AS FAR NORTH AS CHICAGO OR LAKE MICHIGAN
AS THE PLUME OF ELEVATED LAPSE RATES SPREADS OVERHEAD...BUT MORE
LIKELY FARTHER SOUTH CLOSER TO THE STRONGER COMBINED FORCING.
THERE LOOKS TO BE A VERY TIGHT GRADIENT IN THE HEAVY PRECIP AXIS.
HAVE ELECTED TO ISSUE A FLOOD WATCH SIMILAR TO OUR NEIGHBORS DUE
TO THIS POTENTIAL GIVEN THE CONVECTIVE ELEMENTS PRESENT. THERE IS
STILL WITH SOME UNCERTAINTY AS TO IF THIS WILL REMAIN SOUTH OF THE
AREA AS SUGGESTED BY SOME HI-RES GUIDANCE MEMBERS. HAVE CARRIED
THIS WATCH OUT THROUGH THE SECOND EVENT (LONG TERM)...THOUGH THERE
WILL BE A GAP ON SUNDAY. MORE ON THIS IN THE HYDROLOGY SECTION
FORTHCOMING.
KMD
&&
.LONG TERM...
333 AM CST
SUNDAY THROUGH FRIDAY...
THE FOCUS ON THE LONGER RANGE FORECAST IS CERTAINLY WITH THE SUNDAY
NIGHT THROUGH MONDAY NIGHT PRECIPITATION EVENT...WHICH IS TRENDING
MORE TOWARD A RAIN/FREEZING RAIN EVENT. THIS STILL LOOKS TO BE LARGE
CONCERNS OF ICING FROM FREEZING RAIN FOR AT LEAST A PORTION OF THE
AREA...ESPECIALLY AREAS ALONG AND NORTH OF I-80. THERE ALSO IS
CONCERNS THAT THE AMOUNT OF RAIN /WHETHER INITIALLY FREEZING OR NOT/
COULD CAUSE LOCALIZED FLOODING ISSUES AS MONDAY PROGRESSES AND
CERTAINLY SOME QUICK RIVER RISES. IT IS A BIT CLEARER PICTURE THAT
THE POTENTIAL FOR SNOW IS LESS LIKELY THROUGH MONDAY NIGHT. HAVE
ADDED A LITTLE MORE DETAIL IN THE FORECAST...BUT OVERALL KEPT SOME
RANGE OF UNCERTAINTY DUE TO THE SPECIFIC SURFACE TEMPERATURE
FORECASTS AS WELL AS THE LARGER SCALE EXACT TRACK OF THE SYSTEM.
LAST EVENINGS RAOBS INDICATED A STRONG JET STREAM MAXIMUM OF AROUND
150 KT DIGGING SOUTH ACROSS THE WESTERN U.S. WHICH WILL CUT OFF A
CLOSED LOW ACROSS THE DESERT SOUTHWEST/MEXICO BORDER BY TONIGHT.
THIS WILL EVOLVE NORTHEAST IN RESPONSE TO ANOTHER JET MAXIMUM
DIGGING UPSTREAM. A CUTOFF FEATURE SUCH AS THIS LOW AND BEING
FAIRLY FAR SOUTH IN LATITUDE TENDS TO END UP BEING SLOWER THAN A
MEAN MODEL SOLUTION AND WE HAVE SEEN THAT OVER THE PAST COUPLE
MONTHS WITH SYSTEMS LOCATED EVEN FURTHER NORTH. SUCH A SLOWER
EVOLUTION WOULD RESULT IN A FURTHER WEST TRACK AS THE SYSTEM LIFTS
NORTHEAST WHICH IS ADVERTISED BY THE PREFERRED EC...NAM...AND
SREF MORE SO THAN THE GFS...ITS ENSEMBLE...AND THE GEM. THE
OVERALL TREND IN A MEAN OF ALL THESE GUIDANCE HAS ALSO SHIFTED
SLIGHTLY SLOWER AND FURTHER WEST WITH THIS SYSTEM...FURTHER
SUPPORTING LEANING THIS ROUTE. IN ADDITION...THE STRONG CANADIAN
HIGH PRESSURE OVER THE NORTHERN PLAINS THAT COULD OFFER SOME
BLOCKING AND SUPPORT A FURTHER EAST TRACK IN THE LOW IS TRENDING
SLIGHTLY FURTHER NORTH...AGAIN FAVORING LEANING WEST.
FOR SUNDAY...LOW-LEVEL COLD ADVECTION ON GUSTY NORTHERLY WINDS
WILL BE UNDERCUTTING THE ELEVATED BAROCLINIC ZONE AND EXPECT
TEMPERATURES TO REMAIN IN THE 30S BUT FEELING EVEN COLDER. THERE
PROBABLY WILL BE LAKE EFFECT CLOUDS AND MAYBE EVEN SOME DRIZZLE
FROM THAT DURING THE MORNING INTO CHICAGO AND OTHER LAKE ADJACENT
AREAS. AS FOR THE PREVAILING RAIN IN THE SOUTHERN AND EASTERN
FORECAST AREA SUNDAY MORNING...THAT SHOULD EASE SOUTHEASTWARD IN
THE AFTERNOON AS FRONTOGENESIS TEMPORARILY WEAKENS.
THE WARM AND MOIST ADVECTION ALOFT GRADUALLY STRENGTHENS SUNDAY
EVENING IN RESPONSE TO THE UPPER LOW APPROACHING AND REALLY RAMPS UP
EITHER LATE THAT NIGHT OR MONDAY MORNING OVER THE AREA. THE NAM
IS THE SLOWEST ADVANCING ITS PRECIPITATION AND IF CORRECT WOULD
INDICATE NOT MUCH IN THE AREA PRIOR TO DAYBREAK MONDAY...BUT HAVE
LEANED A LITTLE QUICKER THAN ITS SOLUTION GIVEN THE STRENGTH OF
THE MOISTURE ADVECTION.
EASTERLY SURFACE WINDS WILL STRENGTHEN OVERNIGHT GIVEN THE
PRESSURE GRADIENT RAPIDLY TIGHTENING. THIS ALONG WITH CLOUDS
SHOULD KEEP TEMPERATURES FAIRLY STEADY...THOUGH AS MENTIONED IN
PRIOR AFD THAT AT PRECIP ONSET...WHETHER LATE SUNDAY NIGHT OR
MONDAY MORNING...MAY RESULT IN A COUPLE DEGREE TEMPERATURE DROP.
THIS COULD MEAN A WINDOW OF SOME SLEET BUT OVERALL NOT EXPECTING
THAT TO BE THE DOMINANT TYPE OF PRECIPITATION FOR ANY EXTENDED
PERIOD. WITH BIG TIME UPPER SUPPORT FOR LIFT...PRECIPITATION
SHOULD BE AT ITS MAXIMUM COVERAGE AND INTENSITY DURING THE DAY
MONDAY AND AT LEAST EARLY MONDAY EVENING...IF NOT MUCH OF IT.
MIXING RATIOS OF 6-8 G/KG SHOULD SUPPORT MODEST IF NOT TEMPORARILY
HEAVY RATES...AND OBVIOUSLY THATS WHERE CONCERNS ARE REALLY
HEIGHTENED WITH ANY FREEZING RAIN.
GIVEN THE QUICK UPTICK IN INTENSITY OF RAINFALL AND EASTERLY
SURFACE WINDS...HAVE CONTINUED TO KEEP TEMPERATURES SLOW TO WARM
DURING THE DAY. TEMPERATURES STILL SHOULD BE INCHING UP TO OR EVEN
ABOVE FREEZING FROM SOUTH TO NORTH ACROSS THE AREA...BUT THAT
LOOKS LIKE IT WILL LAG THE ONSET OF MODERATE PRECIPITATION AND
THUS CONTINUE WITH FORECAST ICE ACCUMULATION IN THE CWA...NAMELY
THE NORTHERN HALF AWAY FROM THE IMMEDIATE LAKE. FOR AREAS ADJACENT
TO LAKE MICHIGAN...INCLUDING DOWNTOWN CHICAGO...STIFF ONSHORE FLOW
GUSTING TO 40 MPH PLUS /ESPECIALLY NEAR THE LAKE SHORE/ SHOULD
KEEP TEMPERATURES JUST ABOVE FREEZING. TEMPERATURES DO NOT LOOK TO
BE SIGNIFICANTLY BELOW FREEZING WHERE THEY ARE SUB 32...WHICH IS
ONE THING THAT COULD HELP EASE IMPACTS. IF HOWEVER ICE ACCRETION
DOES BEGIN ON LIMBS OR POWER LINES AND OVER SEVERAL HOURS...THE
STRONG WINDS COULD ALLOW FOR HIGHER IMPACTS.
AGAIN IN SUMMARY...THINGS GOING FOR THIS EVENT ARE A STIFF EAST WIND
AND A WIDESPREAD PRECIPITATION SHIELD TO KEEP THE SURFACE
TEMPERATURES FROM WARMING RAPIDLY...OR AT LEAST MORE RAPIDLY THAN
EVEN THE WARMEST GUIDANCE...AND THUS ALLOW FOR WHAT APPEARS TO BE
SEVERAL HOUR DURATION OF FREEZING RAIN. MOST CONCERNED FOR NORTH
CENTRAL ILLINOIS...INCLUDING ROCKFORD...WHERE COLLABORATED ICE
FORECASTS WITH WPC AND ADJACENT WFOS IS PRESENTLY AT OR ABOVE 0.20
OF AN INCH.
TUESDAY STILL LOOKS TO OFFER SOME SNOW POSSIBILITY ON THE
BACKSIDE OF THE SYSTEM...THOUGH WITH IT FILLING AM NOT EXPECTING A
WELL- DEFINED DEFORMATION/WRAPAROUND AS FAR EAST AS THE CWA.
TEMPERATURES LOOK TO EASE DOWN THROUGH THE WEEK INTO UNFAMILIAR
TERRITORY OF BELOW NORMAL BY THE START TO 2016. THERE CONTINUES
TO BE A CHANCE OF SNOW ON WEDNESDAY BUT HAVE GONE WITH A WELL-
VERIFYING MODEL BLEND AT THIS TIME TO FOCUS ON THE PREVIOUS
SYSTEMS.
MTF
&&
.HYDROLOGY...
RAIN DEVELOPING ALONG A STATIONARY FRONT DURING THE DAY
TODAY...AND POSSIBLY HEAVY AT TIMES LATE THIS AFTERNOON TONIGHT...IS
LIKELY TO PERSIST THROUGH EARLY SUNDAY MORNING. THUNDERSTORMS
ALSO ARE POSSIBLE ACROSS SOUTHERN PORTIONS OF THE AREA MAINLY
SOUTH OF THE KANKAKEE RIVER...WHERE WIDESPREAD 1.5 TO 2 INCH
RAINFALL AMOUNTS ARE MOST LIKELY. LOCALIZED AMOUNTS IN EXCESS OF 3
INCHES REMAIN POSSIBLE...THOUGH AT THIS TIME THIS MAY OCCUR JUST
SOUTH OF THE LOCAL AREA. REGARDLESS...THESE RAINFALL AMOUNTS MAY
RESULT IN SIGNIFICANT RISES AND POSSIBLE FLOODING ALONG AREA
RIVERS AND STREAMS...INCLUDING THE IROQUOIS AND KANKAKEE RIVERS AS
WELL AS SUGAR CREEK. IN ADDITION...THE HEAVY RAIN WILL LIKELY
RESULT IN SOME PONDING OF WATER IN LOW LYING AND POOR DRAINAGE
AREAS. SEE THE CURRENT FFALOT FOR MORE DETAILS. THIS APPEARS TO BE
MORE OF A FLOODING SITUATION THAN A TRUE FLASH FLOOD
SITUATION...BUT GIVEN THE CONVECTIVE ELEMENT TO THE PRECIPITATION
AND THE EFFICIENCY OF THE PRECIPITATION EXPECTED TONIGHT AND
SATURATED GROUND...FLOODING COULD OCCUR QUICKLY FOR AREAS STUCK
UNDER HEAVY RAINFALL. THE FLOOD WATCH FOR OUR SOUTHERN COUNTIES WILL
ALSO ACCOUNT FOR ANOTHER 1-1.5 INCHES OF RAINFALL EXPECTED ON
MONDAY.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* -RA/SHRA TRANSITIONING OVER TO DRIZZLE FOR THE REMAINDER OF THE
AFTERNOON THROUGH LATE TONIGHT...THOUGH A FEW LINGERING RAIN
SHOWERS WILL BE POSSIBLE THROUGH AROUND SUNSET. ANOTHER PERIOD
OF -RA LATE TONIGHT.
* IFR CIGS LIKELY THROUGH EARLY EVENING...THEN LIFR CIGS LIKELY
FOR THE LATE EVENING HOURS...BUT IMPROVING TO MVFR DURG THE LATE
NIGHT HOURS.
* EAST WINDS REMAIN ARND 5 TO 10 KT THROUGH LATE AFTERNOON
BACKING NNELY THIS EVENING. WINDS STRENGTHENING AND BECOMING
GUSTY TO ARND 25KT LATE TONIGHT AND TOMORROW.
KREIN
//DISCUSSION...UPDATED 18Z...
A MID LEVEL IMPULSE TRACKING ACROSS THE REGION HAS BROUGHT AN AREA
OF RAIN WITH MVFR CIGS/VIS AND OCNL IFR VIS IN HEAVIER SHOWERS.
SOME ISOLD EMBEDDED TS HAS BEEN OBSERVED WITHIN THE RAIN
AREA...BUT ANY TS HAVE REMAINED SOUTH AND EAST OF THE TERMINALS.
TS POTENTIAL SHOULD END BY 19-20Z AS THE IMPULSE MOVES OFF TO THE
NORTHEAST. MID LEVEL DRY AIR WILL OVERSPREAD THE REGION BEHIND THE
EXITING MID LEVEL IMPULSE...AND RAIN SHOULD TRANSITION OVER TO
DRIZZLE. WITH THE LOWER LEVELS REMAINING VERY MOIST...EXPECT THAT
CIGS/VIS SHOULD LOWER TO PREVAILING IFR BY SUNSET...WITH THE
POTENTIAL FOR LIFR CIGS OVERNIGHT. A MODEST PRESSURE GRADIENT
SHOULD KEEP NNELY WINDS OF 5-10KT THROUGH THE LATE NIGHT
HOURS...SO DO NOT EXPECT DENSE FOG TO FORM. DURG THE EARLY MORNING
HOURS...AS DEEPENING LOW PRESSURE LIFTS NORTHEAST OUT OF ERN
OKLAHOMA THROUGH MISSOURI TOMORROW...EXPECT A STRENGTHENING NNELY
PRESSURE GRADIENT...WITH WINDS GUSTING TO 25KT BY ARND 12Z
TOMORROW MORNING AND SUSTAINED WINDS AND GUSTS LIKELY INCREASING
THROUGH THE DAY TOMORROW AS THE LOW MOVES TO SERN IOWA LATE
TOMORROW AFTERNOON.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN PRECIP/VISBY TRENDS.
* HIGH CONFIDENCE IN IFR/LIFR CIGS...MEDIUM CONFIDENCE IN TIMING
OF IFR/LIFR CIGS.
* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...WINTRY MIX POSSIBLE LATE. MVFR CIGS PSBL.
MONDAY...WINTRY MIX TURNING TO RAIN. MVFR CIGS AND VSBYS.
TUESDAY...MVFR CIGS. CHANCE OF -SN/RA IN THE MORNING.
WEDNESDAY...MVFR CIGS. CHANCE OF -SN.
THURSDAY...MVFR CIGS.
FRIDAY...DRY. VFR.
KMD
&&
.MARINE...
213 PM CST
QUITE A FEW QUESTIONS FOR THE MARINE FORECAST OVER THE NEXT TWO OR
THREE DAYS. THE MAIN EVENT OF CONCERN WILL BE ON MONDAY WITH A PROLONGED
PERIOD OF NORTHEAST GALES...WITH POSSIBLE STORM FORCE GUSTS ACROSS THE
SOUTH HALF. AT THE PRESENT TIME A SMALL CRAFT ADVISORY IN EFFECT FOR
THE IL WATERS WILL BE EXTENDED THROUGH TOMORROW NIGHT...UP UNTIL THE
TIME OF THE GALES ON MONDAY. AN ADDITIONAL ADVISORY FOR THE INDIANA
WATERS WILL GO INTO EFFECT FOR THE SAME PERIOD STARTING THIS
EVENING. WINDS AND WAVES WILL BOTH BE A CONCERN. THERE ALSO IS A
CONCERN THAT LOW END GALES MAY DEVELOP FOR A TIME TOMORROW
AFTERNOON...BUT THIS WOULD BE MAINLY IN THE GUSTS AND NOWHERE
CLOSE TO THE STRENGTH OF WINDS ON MONDAY.
FOR MONDAY THERE WAS QUITE A BIT OF THOUGHT AND DISCUSSION ABOUT
GOING WITH A STORM WATCH ACROSS THE SOUTH HALF...BUT FOR NOW WILL
GO WITH A WATCH FOR HIGH END GALES AND JUST MENTION THE
POSSIBILITY OF OCCASIONAL STORM FORCE GUSTS ACROSS THE SOUTH HALF.
THIS MAY NEED TO BE UPGRADED AS THE EVENT APPROACHES.
AFTER THE EVENT TO START THE WEEK...WINDS DIMINISH AND TURN WEST
ON TUESDAY THEN GENERALLY MAINTAIN A WESTERLY COMPONENT FOR THE
REMAINDER OF THE WEEK.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ033-ILZ039...6 PM SATURDAY TO 6 PM MONDAY.
LAKESHORE FLOOD WATCH...ILZ006-ILZ014...9 AM MONDAY TO 9 PM
MONDAY.
IN...FLASH FLOOD WATCH...INZ010-INZ011-INZ019...6 PM SATURDAY TO 6 PM
MONDAY.
LM...GALE WATCH...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...3 AM MONDAY TO 3 AM TUESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 3 AM MONDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...6 PM SATURDAY TO 3
AM MONDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
148 PM CST SAT DEC 26 2015
.UPDATE...
1108 AM CST
TSRA COVERAGE SEEMS TO BE ON A DOWNWARD TREND LATE THIS MORNING
AFTER A LITTLE MORE ACTIVITY SOUTH AND WEST THAN MIGHT HAVE BEEN
EXPECTED EARLIER TODAY. FOCUS FOR ADDITIONAL TSRA WILL SHIFT
WELL SOUTH OF THE CHICAGO METRO AREA MAINLY TO PORTIONS OF NW
INDIANA ALONG WITH THE ANTICIPATED AXIS OF HEAVIER RAINFALL. MAY
EVEN BE ABLE TO LOWER POPS IN NORTHERN PORTIONS OF THE AREA TOWARD
ROCKFORD AND THE WI LINE THIS AFTERNOON...OR CARRY JUST A MENTION
OF DRIZZLE. EVEN IN THE CHICAGO METRO AREA...DRIZZLE MIGHT BE THE
MAIN WEATHER TYPE THIS AFTERNOON AS THE LATEST AMDAR SOUNDINGS OUT
OF MDW ARE SHOWING JUST A RELATIVELY SHALLOW SATURATED LAYER TO
ABOUT 850 MB WITH DRY AIR ABOVE THAT. THIS ALSO CORRESPONDS TO
WHAT THE RAP IS SHOWING...WITH AN INCREASINGLY SHALLOW SATURATED
LAYER AS THE AFTERNOON PROGRESSES.
WINDS WILL RELAX THIS AFTERNOON AND TONIGHT BEFORE PICKING UP
CONSIDERABLY AGAIN TOMORROW MORNING.
LENNING
&&
.SHORT TERM...
411 AM CST
THROUGH TONIGHT...
FOCUS IS ON MODERATE TO LOCALLY HEAVY RAINFALL LATE THIS AFTERNOON
THROUGH TONIGHT.
DEEP UPPER LEVEL LOW PRESSURE CONTINUES TO STRENGTHEN OVER THE
DESTER SOUTHWEST...WITH STRONG AND UNSEASONABLY MOIST/WARM
ADVECTION OCCURRING OUT AHEAD OF THE LOW. SEVERAL COMPLEXES OF
THUNDERSTORMS ARE ONGOING IN THE WARM ADVECTIVE REGIME NORTH OF A
WARM FRONTAL BOUNDARY DRAPED FROM THE ARKLATEX REGION THEN
NORTHEAST INTO THE TENNESSEE VALLEY IN AN AREA OF ELEVATED MID
LEVEL LAPSE RATES. AN ADDITIONAL AREA OF PRECIPITATION IS
OCCURRING NORTH OF AN INVERTED SURFACE TROUGH.
THIS WARM/MOIST BOUNDARY CONTINUES TO ADVECT NORTHWARD THIS
MORNING WITH A PLUME OF NEAR RECORD PRECIPITABLE WATER VALUES.
WITH COOL NORTHEAST WINDS IN PLACE AHEAD ANCHORING THE LOW LEVEL
FRONTAL BOUNDARY TO OUR SOUTH WILL CREATE A RECIPE FOR LOW CLOUDS
TO OVERSPREAD THE AREA THIS MORNING...AS FORECAST SOUNDINGS
DEPICT RAPID SATURATION OF THE LOWER LEVELS WHICH HAS BEEN
OCCURRING DOWNSTATE. AS CLOUDS LOWER...EXPECT SOME FOG TO DEVELOP
AS WELL.
THE INVERTED TROUGH AXIS SHIFTS AND IS POINTED AT OUR AREA AROUND
MIDDAY. AS THIS OCCURS IN CONJUNCTION WITH ISENTROPIC
ASCENT...EXPECT AN INCREASE IN INITIALLY LIGHTER RAIN SHOWERS THIS
MORNING DUE TO LACK OF DEEPER SATURATION...THEN AS FORCING
INCREASES AHEAD OF A NORTHERN STREAM SHORTWAVE...STRENGTHENING
UPPER LEVEL JET MAXIMUM TO OUR NORTHWEST...AND A STRONG LOW TO MID
LEVEL FRONTOGENESIS OCCURRING DUE TO THE AIRMASS CLASH...EXPECT
SHOWERS TO BLOSSOM THIS AFTERNOON AND EVENING. PRECIPITATION MAY
DWINDLE TO LIGHTER RAIN/DRIZZLE FARTHER NORTH...BUT THERE ARE
ADDITIONAL WAVES THAT WILL RIDE ALONG THE LOW AND ELEVATED
BAROCLINIC ZONES TO KEEP A MENTION OF RAIN GOING AREA-WIDE TONIGHT.
THE FRONT LOOKS TO BE MOST ACTIVE ALONG OUR SOUTHERN COUNTIES
WHERE EXTREME FRONTOGENESIS COMBINED WITH THE RECORD PWATS WILL
LEAD TO PERIODS OF MODERATE TO HEAVY RAINFALL. THUNDER IS
CERTAINLY POSSIBLE EVEN AS FAR NORTH AS CHICAGO OR LAKE MICHIGAN
AS THE PLUME OF ELEVATED LAPSE RATES SPREADS OVERHEAD...BUT MORE
LIKELY FARTHER SOUTH CLOSER TO THE STRONGER COMBINED FORCING.
THERE LOOKS TO BE A VERY TIGHT GRADIENT IN THE HEAVY PRECIP AXIS.
HAVE ELECTED TO ISSUE A FLOOD WATCH SIMILAR TO OUR NEIGHBORS DUE
TO THIS POTENTIAL GIVEN THE CONVECTIVE ELEMENTS PRESENT. THERE IS
STILL WITH SOME UNCERTAINTY AS TO IF THIS WILL REMAIN SOUTH OF THE
AREA AS SUGGESTED BY SOME HI-RES GUIDANCE MEMBERS. HAVE CARRIED
THIS WATCH OUT THROUGH THE SECOND EVENT (LONG TERM)...THOUGH THERE
WILL BE A GAP ON SUNDAY. MORE ON THIS IN THE HYDROLOGY SECTION
FORTHCOMING.
KMD
&&
.LONG TERM...
333 AM CST
SUNDAY THROUGH FRIDAY...
THE FOCUS ON THE LONGER RANGE FORECAST IS CERTAINLY WITH THE SUNDAY
NIGHT THROUGH MONDAY NIGHT PRECIPITATION EVENT...WHICH IS TRENDING
MORE TOWARD A RAIN/FREEZING RAIN EVENT. THIS STILL LOOKS TO BE LARGE
CONCERNS OF ICING FROM FREEZING RAIN FOR AT LEAST A PORTION OF THE
AREA...ESPECIALLY AREAS ALONG AND NORTH OF I-80. THERE ALSO IS
CONCERNS THAT THE AMOUNT OF RAIN /WHETHER INITIALLY FREEZING OR NOT/
COULD CAUSE LOCALIZED FLOODING ISSUES AS MONDAY PROGRESSES AND
CERTAINLY SOME QUICK RIVER RISES. IT IS A BIT CLEARER PICTURE THAT
THE POTENTIAL FOR SNOW IS LESS LIKELY THROUGH MONDAY NIGHT. HAVE
ADDED A LITTLE MORE DETAIL IN THE FORECAST...BUT OVERALL KEPT SOME
RANGE OF UNCERTAINTY DUE TO THE SPECIFIC SURFACE TEMPERATURE
FORECASTS AS WELL AS THE LARGER SCALE EXACT TRACK OF THE SYSTEM.
LAST EVENINGS RAOBS INDICATED A STRONG JET STREAM MAXIMUM OF AROUND
150 KT DIGGING SOUTH ACROSS THE WESTERN U.S. WHICH WILL CUT OFF A
CLOSED LOW ACROSS THE DESERT SOUTHWEST/MEXICO BORDER BY TONIGHT.
THIS WILL EVOLVE NORTHEAST IN RESPONSE TO ANOTHER JET MAXIMUM
DIGGING UPSTREAM. A CUTOFF FEATURE SUCH AS THIS LOW AND BEING
FAIRLY FAR SOUTH IN LATITUDE TENDS TO END UP BEING SLOWER THAN A
MEAN MODEL SOLUTION AND WE HAVE SEEN THAT OVER THE PAST COUPLE
MONTHS WITH SYSTEMS LOCATED EVEN FURTHER NORTH. SUCH A SLOWER
EVOLUTION WOULD RESULT IN A FURTHER WEST TRACK AS THE SYSTEM LIFTS
NORTHEAST WHICH IS ADVERTISED BY THE PREFERRED EC...NAM...AND
SREF MORE SO THAN THE GFS...ITS ENSEMBLE...AND THE GEM. THE
OVERALL TREND IN A MEAN OF ALL THESE GUIDANCE HAS ALSO SHIFTED
SLIGHTLY SLOWER AND FURTHER WEST WITH THIS SYSTEM...FURTHER
SUPPORTING LEANING THIS ROUTE. IN ADDITION...THE STRONG CANADIAN
HIGH PRESSURE OVER THE NORTHERN PLAINS THAT COULD OFFER SOME
BLOCKING AND SUPPORT A FURTHER EAST TRACK IN THE LOW IS TRENDING
SLIGHTLY FURTHER NORTH...AGAIN FAVORING LEANING WEST.
FOR SUNDAY...LOW-LEVEL COLD ADVECTION ON GUSTY NORTHERLY WINDS
WILL BE UNDERCUTTING THE ELEVATED BAROCLINIC ZONE AND EXPECT
TEMPERATURES TO REMAIN IN THE 30S BUT FEELING EVEN COLDER. THERE
PROBABLY WILL BE LAKE EFFECT CLOUDS AND MAYBE EVEN SOME DRIZZLE
FROM THAT DURING THE MORNING INTO CHICAGO AND OTHER LAKE ADJACENT
AREAS. AS FOR THE PREVAILING RAIN IN THE SOUTHERN AND EASTERN
FORECAST AREA SUNDAY MORNING...THAT SHOULD EASE SOUTHEASTWARD IN
THE AFTERNOON AS FRONTOGENESIS TEMPORARILY WEAKENS.
THE WARM AND MOIST ADVECTION ALOFT GRADUALLY STRENGTHENS SUNDAY
EVENING IN RESPONSE TO THE UPPER LOW APPROACHING AND REALLY RAMPS UP
EITHER LATE THAT NIGHT OR MONDAY MORNING OVER THE AREA. THE NAM
IS THE SLOWEST ADVANCING ITS PRECIPITATION AND IF CORRECT WOULD
INDICATE NOT MUCH IN THE AREA PRIOR TO DAYBREAK MONDAY...BUT HAVE
LEANED A LITTLE QUICKER THAN ITS SOLUTION GIVEN THE STRENGTH OF
THE MOISTURE ADVECTION.
EASTERLY SURFACE WINDS WILL STRENGTHEN OVERNIGHT GIVEN THE
PRESSURE GRADIENT RAPIDLY TIGHTENING. THIS ALONG WITH CLOUDS
SHOULD KEEP TEMPERATURES FAIRLY STEADY...THOUGH AS MENTIONED IN
PRIOR AFD THAT AT PRECIP ONSET...WHETHER LATE SUNDAY NIGHT OR
MONDAY MORNING...MAY RESULT IN A COUPLE DEGREE TEMPERATURE DROP.
THIS COULD MEAN A WINDOW OF SOME SLEET BUT OVERALL NOT EXPECTING
THAT TO BE THE DOMINANT TYPE OF PRECIPITATION FOR ANY EXTENDED
PERIOD. WITH BIG TIME UPPER SUPPORT FOR LIFT...PRECIPITATION
SHOULD BE AT ITS MAXIMUM COVERAGE AND INTENSITY DURING THE DAY
MONDAY AND AT LEAST EARLY MONDAY EVENING...IF NOT MUCH OF IT.
MIXING RATIOS OF 6-8 G/KG SHOULD SUPPORT MODEST IF NOT TEMPORARILY
HEAVY RATES...AND OBVIOUSLY THATS WHERE CONCERNS ARE REALLY
HEIGHTENED WITH ANY FREEZING RAIN.
GIVEN THE QUICK UPTICK IN INTENSITY OF RAINFALL AND EASTERLY
SURFACE WINDS...HAVE CONTINUED TO KEEP TEMPERATURES SLOW TO WARM
DURING THE DAY. TEMPERATURES STILL SHOULD BE INCHING UP TO OR EVEN
ABOVE FREEZING FROM SOUTH TO NORTH ACROSS THE AREA...BUT THAT
LOOKS LIKE IT WILL LAG THE ONSET OF MODERATE PRECIPITATION AND
THUS CONTINUE WITH FORECAST ICE ACCUMULATION IN THE CWA...NAMELY
THE NORTHERN HALF AWAY FROM THE IMMEDIATE LAKE. FOR AREAS ADJACENT
TO LAKE MICHIGAN...INCLUDING DOWNTOWN CHICAGO...STIFF ONSHORE FLOW
GUSTING TO 40 MPH PLUS /ESPECIALLY NEAR THE LAKE SHORE/ SHOULD
KEEP TEMPERATURES JUST ABOVE FREEZING. TEMPERATURES DO NOT LOOK TO
BE SIGNIFICANTLY BELOW FREEZING WHERE THEY ARE SUB 32...WHICH IS
ONE THING THAT COULD HELP EASE IMPACTS. IF HOWEVER ICE ACCRETION
DOES BEGIN ON LIMBS OR POWER LINES AND OVER SEVERAL HOURS...THE
STRONG WINDS COULD ALLOW FOR HIGHER IMPACTS.
AGAIN IN SUMMARY...THINGS GOING FOR THIS EVENT ARE A STIFF EAST WIND
AND A WIDESPREAD PRECIPITATION SHIELD TO KEEP THE SURFACE
TEMPERATURES FROM WARMING RAPIDLY...OR AT LEAST MORE RAPIDLY THAN
EVEN THE WARMEST GUIDANCE...AND THUS ALLOW FOR WHAT APPEARS TO BE
SEVERAL HOUR DURATION OF FREEZING RAIN. MOST CONCERNED FOR NORTH
CENTRAL ILLINOIS...INCLUDING ROCKFORD...WHERE COLLABORATED ICE
FORECASTS WITH WPC AND ADJACENT WFOS IS PRESENTLY AT OR ABOVE 0.20
OF AN INCH.
TUESDAY STILL LOOKS TO OFFER SOME SNOW POSSIBILITY ON THE
BACKSIDE OF THE SYSTEM...THOUGH WITH IT FILLING AM NOT EXPECTING A
WELL- DEFINED DEFORMATION/WRAPAROUND AS FAR EAST AS THE CWA.
TEMPERATURES LOOK TO EASE DOWN THROUGH THE WEEK INTO UNFAMILIAR
TERRITORY OF BELOW NORMAL BY THE START TO 2016. THERE CONTINUES
TO BE A CHANCE OF SNOW ON WEDNESDAY BUT HAVE GONE WITH A WELL-
VERIFYING MODEL BLEND AT THIS TIME TO FOCUS ON THE PREVIOUS
SYSTEMS.
MTF
&&
.HYDROLOGY...
RAIN DEVELOPING ALONG A STATIONARY FRONT DURING THE DAY
TODAY...AND POSSIBLY HEAVY AT TIMES LATE THIS AFTERNOON TONIGHT...IS
LIKELY TO PERSIST THROUGH EARLY SUNDAY MORNING. THUNDERSTORMS
ALSO ARE POSSIBLE ACROSS SOUTHERN PORTIONS OF THE AREA MAINLY
SOUTH OF THE KANKAKEE RIVER...WHERE WIDESPREAD 1.5 TO 2 INCH
RAINFALL AMOUNTS ARE MOST LIKELY. LOCALIZED AMOUNTS IN EXCESS OF 3
INCHES REMAIN POSSIBLE...THOUGH AT THIS TIME THIS MAY OCCUR JUST
SOUTH OF THE LOCAL AREA. REGARDLESS...THESE RAINFALL AMOUNTS MAY
RESULT IN SIGNIFICANT RISES AND POSSIBLE FLOODING ALONG AREA
RIVERS AND STREAMS...INCLUDING THE IROQUOIS AND KANKAKEE RIVERS AS
WELL AS SUGAR CREEK. IN ADDITION...THE HEAVY RAIN WILL LIKELY
RESULT IN SOME PONDING OF WATER IN LOW LYING AND POOR DRAINAGE
AREAS. SEE THE CURRENT FFALOT FOR MORE DETAILS. THIS APPEARS TO BE
MORE OF A FLOODING SITUATION THAN A TRUE FLASH FLOOD
SITUATION...BUT GIVEN THE CONVECTIVE ELEMENT TO THE PRECIPITATION
AND THE EFFICIENCY OF THE PRECIPITATION EXPECTED TONIGHT AND
SATURATED GROUND...FLOODING COULD OCCUR QUICKLY FOR AREAS STUCK
UNDER HEAVY RAINFALL. THE FLOOD WATCH FOR OUR SOUTHERN COUNTIES WILL
ALSO ACCOUNT FOR ANOTHER 1-1.5 INCHES OF RAINFALL EXPECTED ON
MONDAY.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* -RA/SHRA TRANSITIONING OVER TO DRIZZLE FOR THE REMAINDER OF THE
AFTERNOON THROUGH LATE TONIGHT...THOUGH A FEW LINGERING RAIN
SHOWERS WILL BE POSSIBLE THROUGH AROUND SUNSET. ANOTHER PERIOD
OF -RA LATE TONIGHT.
* IFR CIGS LIKELY THROUGH EARLY EVENING...THEN LIFR CIGS LIKELY
FOR THE LATE EVENING HOURS...BUT IMPROVING TO MVFR DURG THE LATE
NIGHT HOURS.
* EAST WINDS REMAIN ARND 5 TO 10 KT THROUGH LATE AFTERNOON
BACKING NNELY THIS EVENING. WINDS STRENGTHENING AND BECOMING
GUSTY TO ARND 25KT LATE TONIGHT AND TOMORROW.
KREIN
//DISCUSSION...UPDATED 18Z...
A MID LEVEL IMPULSE TRACKING ACROSS THE REGION HAS BROUGHT AN AREA
OF RAIN WITH MVFR CIGS/VIS AND OCNL IFR VIS IN HEAVIER SHOWERS.
SOME ISOLD EMBEDDED TS HAS BEEN OBSERVED WITHIN THE RAIN
AREA...BUT ANY TS HAVE REMAINED SOUTH AND EAST OF THE TERMINALS.
TS POTENTIAL SHOULD END BY 19-20Z AS THE IMPULSE MOVES OFF TO THE
NORTHEAST. MID LEVEL DRY AIR WILL OVERSPREAD THE REGION BEHIND THE
EXITING MID LEVEL IMPULSE...AND RAIN SHOULD TRANSITION OVER TO
DRIZZLE. WITH THE LOWER LEVELS REMAINING VERY MOIST...EXPECT THAT
CIGS/VIS SHOULD LOWER TO PREVAILING IFR BY SUNSET...WITH THE
POTENTIAL FOR LIFR CIGS OVERNIGHT. A MODEST PRESSURE GRADIENT
SHOULD KEEP NNELY WINDS OF 5-10KT THROUGH THE LATE NIGHT
HOURS...SO DO NOT EXPECT DENSE FOG TO FORM. DURG THE EARLY MORNING
HOURS...AS DEEPENING LOW PRESSURE LIFTS NORTHEAST OUT OF ERN
OKLAHOMA THROUGH MISSOURI TOMORROW...EXPECT A STRENGTHENING NNELY
PRESSURE GRADIENT...WITH WINDS GUSTING TO 25KT BY ARND 12Z
TOMORROW MORNING AND SUSTAINED WINDS AND GUSTS LIKELY INCREASING
THROUGH THE DAY TOMORROW AS THE LOW MOVES TO SERN IOWA LATE
TOMORROW AFTERNOON.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN PRECIP/VISBY TRENDS.
* HIGH CONFIDENCE IN IFR/LIFR CIGS...MEDIUM CONFIDENCE IN TIMING
OF IFR/LIFR CIGS.
* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...WINTRY MIX POSSIBLE LATE. MVFR CIGS PSBL.
MONDAY...WINTRY MIX TURNING TO RAIN. MVFR CIGS AND VSBYS.
TUESDAY...MVFR CIGS. CHANCE OF -SN/RA IN THE MORNING.
WEDNESDAY...MVFR CIGS. CHANCE OF -SN.
THURSDAY...MVFR CIGS.
FRIDAY...DRY. VFR.
KMD
&&
.MARINE...
456 AM CST
.HIGH PRESSURE OVER THE NORTHERN LAKES WILL QUICKLY MOVE EAST
TODAY...WHILE LOW PRESSURE DEVELOPS OVER THE SOUTHERN PLAINS. THIS
LOW WILL MOVE QUICKLY NORTHEAST ACROSS THE MIDWEST THIS AFTERNOON
AND INTO NEW ENGLAND BY EARLY SUNDAY. EXPECT WINDS TO RAMP UP
BETWEEN THESE TWO FEATURES RESULTING IN SOME HIGHER WAVES ALONG
THE ILLINOIS SIDE TODAY. STRONG HIGH PRESSURE OVER THE UPPER
MIDWEST EXTENDING INTO SOUTHERN MANITOBA WILL BUILD EAST ACROSS
ONTARIO LATE IN THE WEEKEND...WHILE ANOTHER DEEP LOW DEVELOPS
ACROSS TEXAS. AHEAD OF THE STRONG HIGH...A SURGE OF NORTH WINDS TO
30 KT...POSSIBLY A FEW GALE GUSTS...WILL OCCUR LATE TONIGHT INTO
SUNDAY.
THIS SECOND LOW WILL THEN DEEPEN OVER THE LOWER MISSOURI VALLEY
MONDAY MORNING...THEN WILL LIFT NORTHEAST ACROSS WESTERN GREAT
LAKES BY EARLY TUESDAY BEFORE FILLING. THE GRADIENT BETWEEN THIS
LOW AND THE VERY STRONG HIGH WHICH ONLY SLOWLY MOVES EAST WILL
RESULT IN A PERIOD OF STRONG GALES MONDAY...POSSIBLY WITH A FEW
STORM FORCE WIND GUSTS ALONG WITH COASTAL FLOODING ISSUES ALONG
THE ILLINOIS NEARSHORE. ANOTHER WEAK LOW WILL MOVE OVER THE
NORTHERN HALF OF THE LAKE WEDNESDAY FOLLOWED BY COOL HIGH
PRESSURE.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ033-ILZ039...6 PM SATURDAY TO 6 PM MONDAY.
IN...FLASH FLOOD WATCH...INZ010-INZ011-INZ019...6 PM SATURDAY TO 6 PM
MONDAY.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 6 PM SATURDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1155 AM CST SAT DEC 26 2015
.UPDATE...
1108 AM CST
TSRA COVERAGE SEEMS TO BE ON A DOWNWARD TREND LATE THIS MORNING
AFTER A LITTLE MORE ACTIVITY SOUTH AND WEST THAN MIGHT HAVE BEEN
EXPECTED EARLIER TODAY. FOCUS FOR ADDITIONAL TSRA WILL SHIFT
WELL SOUTH OF THE CHICAGO METRO AREA MAINLY TO PORTIONS OF NW
INDIANA ALONG WITH THE ANTICIPATED AXIS OF HEAVIER RAINFALL. MAY
EVEN BE ABLE TO LOWER POPS IN NORTHERN PORTIONS OF THE AREA TOWARD
ROCKFORD AND THE WI LINE THIS AFTERNOON...OR CARRY JUST A MENTION
OF DRIZZLE. EVEN IN THE CHICAGO METRO AREA...DRIZZLE MIGHT BE THE
MAIN WEATHER TYPE THIS AFTERNOON AS THE LATEST AMDAR SOUNDINGS OUT
OF MDW ARE SHOWING JUST A RELATIVELY SHALLOW SATURATED LAYER TO
ABOUT 850 MB WITH DRY AIR ABOVE THAT. THIS ALSO CORRESPONDS TO
WHAT THE RAP IS SHOWING...WITH AN INCREASINGLY SHALLOW SATURATED
LAYER AS THE AFTERNOON PROGRESSES.
WINDS WILL RELAX THIS AFTERNOON AND TONIGHT BEFORE PICKING UP
CONSIDERABLY AGAIN TOMORROW MORNING.
LENNING
&&
.SHORT TERM...
411 AM CST
THROUGH TONIGHT...
FOCUS IS ON MODERATE TO LOCALLY HEAVY RAINFALL LATE THIS AFTERNOON
THROUGH TONIGHT.
DEEP UPPER LEVEL LOW PRESSURE CONTINUES TO STRENGTHEN OVER THE
DESTER SOUTHWEST...WITH STRONG AND UNSEASONABLY MOIST/WARM
ADVECTION OCCURRING OUT AHEAD OF THE LOW. SEVERAL COMPLEXES OF
THUNDERSTORMS ARE ONGOING IN THE WARM ADVECTIVE REGIME NORTH OF A
WARM FRONTAL BOUNDARY DRAPED FROM THE ARKLATEX REGION THEN
NORTHEAST INTO THE TENNESSEE VALLEY IN AN AREA OF ELEVATED MID
LEVEL LAPSE RATES. AN ADDITIONAL AREA OF PRECIPITATION IS
OCCURRING NORTH OF AN INVERTED SURFACE TROUGH.
THIS WARM/MOIST BOUNDARY CONTINUES TO ADVECT NORTHWARD THIS
MORNING WITH A PLUME OF NEAR RECORD PRECIPITABLE WATER VALUES.
WITH COOL NORTHEAST WINDS IN PLACE AHEAD ANCHORING THE LOW LEVEL
FRONTAL BOUNDARY TO OUR SOUTH WILL CREATE A RECIPE FOR LOW CLOUDS
TO OVERSPREAD THE AREA THIS MORNING...AS FORECAST SOUNDINGS
DEPICT RAPID SATURATION OF THE LOWER LEVELS WHICH HAS BEEN
OCCURRING DOWNSTATE. AS CLOUDS LOWER...EXPECT SOME FOG TO DEVELOP
AS WELL.
THE INVERTED TROUGH AXIS SHIFTS AND IS POINTED AT OUR AREA AROUND
MIDDAY. AS THIS OCCURS IN CONJUNCTION WITH ISENTROPIC
ASCENT...EXPECT AN INCREASE IN INITIALLY LIGHTER RAIN SHOWERS THIS
MORNING DUE TO LACK OF DEEPER SATURATION...THEN AS FORCING
INCREASES AHEAD OF A NORTHERN STREAM SHORTWAVE...STRENGTHENING
UPPER LEVEL JET MAXIMUM TO OUR NORTHWEST...AND A STRONG LOW TO MID
LEVEL FRONTOGENESIS OCCURRING DUE TO THE AIRMASS CLASH...EXPECT
SHOWERS TO BLOSSOM THIS AFTERNOON AND EVENING. PRECIPITATION MAY
DWINDLE TO LIGHTER RAIN/DRIZZLE FARTHER NORTH...BUT THERE ARE
ADDITIONAL WAVES THAT WILL RIDE ALONG THE LOW AND ELEVATED
BAROCLINIC ZONES TO KEEP A MENTION OF RAIN GOING AREA-WIDE TONIGHT.
THE FRONT LOOKS TO BE MOST ACTIVE ALONG OUR SOUTHERN COUNTIES
WHERE EXTREME FRONTOGENESIS COMBINED WITH THE RECORD PWATS WILL
LEAD TO PERIODS OF MODERATE TO HEAVY RAINFALL. THUNDER IS
CERTAINLY POSSIBLE EVEN AS FAR NORTH AS CHICAGO OR LAKE MICHIGAN
AS THE PLUME OF ELEVATED LAPSE RATES SPREADS OVERHEAD...BUT MORE
LIKELY FARTHER SOUTH CLOSER TO THE STRONGER COMBINED FORCING.
THERE LOOKS TO BE A VERY TIGHT GRADIENT IN THE HEAVY PRECIP AXIS.
HAVE ELECTED TO ISSUE A FLOOD WATCH SIMILAR TO OUR NEIGHBORS DUE
TO THIS POTENTIAL GIVEN THE CONVECTIVE ELEMENTS PRESENT. THERE IS
STILL WITH SOME UNCERTAINTY AS TO IF THIS WILL REMAIN SOUTH OF THE
AREA AS SUGGESTED BY SOME HI-RES GUIDANCE MEMBERS. HAVE CARRIED
THIS WATCH OUT THROUGH THE SECOND EVENT (LONG TERM)...THOUGH THERE
WILL BE A GAP ON SUNDAY. MORE ON THIS IN THE HYDROLOGY SECTION
FORTHCOMING.
KMD
&&
.LONG TERM...
333 AM CST
SUNDAY THROUGH FRIDAY...
THE FOCUS ON THE LONGER RANGE FORECAST IS CERTAINLY WITH THE SUNDAY
NIGHT THROUGH MONDAY NIGHT PRECIPITATION EVENT...WHICH IS TRENDING
MORE TOWARD A RAIN/FREEZING RAIN EVENT. THIS STILL LOOKS TO BE LARGE
CONCERNS OF ICING FROM FREEZING RAIN FOR AT LEAST A PORTION OF THE
AREA...ESPECIALLY AREAS ALONG AND NORTH OF I-80. THERE ALSO IS
CONCERNS THAT THE AMOUNT OF RAIN /WHETHER INITIALLY FREEZING OR NOT/
COULD CAUSE LOCALIZED FLOODING ISSUES AS MONDAY PROGRESSES AND
CERTAINLY SOME QUICK RIVER RISES. IT IS A BIT CLEARER PICTURE THAT
THE POTENTIAL FOR SNOW IS LESS LIKELY THROUGH MONDAY NIGHT. HAVE
ADDED A LITTLE MORE DETAIL IN THE FORECAST...BUT OVERALL KEPT SOME
RANGE OF UNCERTAINTY DUE TO THE SPECIFIC SURFACE TEMPERATURE
FORECASTS AS WELL AS THE LARGER SCALE EXACT TRACK OF THE SYSTEM.
LAST EVENINGS RAOBS INDICATED A STRONG JET STREAM MAXIMUM OF AROUND
150 KT DIGGING SOUTH ACROSS THE WESTERN U.S. WHICH WILL CUT OFF A
CLOSED LOW ACROSS THE DESERT SOUTHWEST/MEXICO BORDER BY TONIGHT.
THIS WILL EVOLVE NORTHEAST IN RESPONSE TO ANOTHER JET MAXIMUM
DIGGING UPSTREAM. A CUTOFF FEATURE SUCH AS THIS LOW AND BEING
FAIRLY FAR SOUTH IN LATITUDE TENDS TO END UP BEING SLOWER THAN A
MEAN MODEL SOLUTION AND WE HAVE SEEN THAT OVER THE PAST COUPLE
MONTHS WITH SYSTEMS LOCATED EVEN FURTHER NORTH. SUCH A SLOWER
EVOLUTION WOULD RESULT IN A FURTHER WEST TRACK AS THE SYSTEM LIFTS
NORTHEAST WHICH IS ADVERTISED BY THE PREFERRED EC...NAM...AND
SREF MORE SO THAN THE GFS...ITS ENSEMBLE...AND THE GEM. THE
OVERALL TREND IN A MEAN OF ALL THESE GUIDANCE HAS ALSO SHIFTED
SLIGHTLY SLOWER AND FURTHER WEST WITH THIS SYSTEM...FURTHER
SUPPORTING LEANING THIS ROUTE. IN ADDITION...THE STRONG CANADIAN
HIGH PRESSURE OVER THE NORTHERN PLAINS THAT COULD OFFER SOME
BLOCKING AND SUPPORT A FURTHER EAST TRACK IN THE LOW IS TRENDING
SLIGHTLY FURTHER NORTH...AGAIN FAVORING LEANING WEST.
FOR SUNDAY...LOW-LEVEL COLD ADVECTION ON GUSTY NORTHERLY WINDS
WILL BE UNDERCUTTING THE ELEVATED BAROCLINIC ZONE AND EXPECT
TEMPERATURES TO REMAIN IN THE 30S BUT FEELING EVEN COLDER. THERE
PROBABLY WILL BE LAKE EFFECT CLOUDS AND MAYBE EVEN SOME DRIZZLE
FROM THAT DURING THE MORNING INTO CHICAGO AND OTHER LAKE ADJACENT
AREAS. AS FOR THE PREVAILING RAIN IN THE SOUTHERN AND EASTERN
FORECAST AREA SUNDAY MORNING...THAT SHOULD EASE SOUTHEASTWARD IN
THE AFTERNOON AS FRONTOGENESIS TEMPORARILY WEAKENS.
THE WARM AND MOIST ADVECTION ALOFT GRADUALLY STRENGTHENS SUNDAY
EVENING IN RESPONSE TO THE UPPER LOW APPROACHING AND REALLY RAMPS UP
EITHER LATE THAT NIGHT OR MONDAY MORNING OVER THE AREA. THE NAM
IS THE SLOWEST ADVANCING ITS PRECIPITATION AND IF CORRECT WOULD
INDICATE NOT MUCH IN THE AREA PRIOR TO DAYBREAK MONDAY...BUT HAVE
LEANED A LITTLE QUICKER THAN ITS SOLUTION GIVEN THE STRENGTH OF
THE MOISTURE ADVECTION.
EASTERLY SURFACE WINDS WILL STRENGTHEN OVERNIGHT GIVEN THE
PRESSURE GRADIENT RAPIDLY TIGHTENING. THIS ALONG WITH CLOUDS
SHOULD KEEP TEMPERATURES FAIRLY STEADY...THOUGH AS MENTIONED IN
PRIOR AFD THAT AT PRECIP ONSET...WHETHER LATE SUNDAY NIGHT OR
MONDAY MORNING...MAY RESULT IN A COUPLE DEGREE TEMPERATURE DROP.
THIS COULD MEAN A WINDOW OF SOME SLEET BUT OVERALL NOT EXPECTING
THAT TO BE THE DOMINANT TYPE OF PRECIPITATION FOR ANY EXTENDED
PERIOD. WITH BIG TIME UPPER SUPPORT FOR LIFT...PRECIPITATION
SHOULD BE AT ITS MAXIMUM COVERAGE AND INTENSITY DURING THE DAY
MONDAY AND AT LEAST EARLY MONDAY EVENING...IF NOT MUCH OF IT.
MIXING RATIOS OF 6-8 G/KG SHOULD SUPPORT MODEST IF NOT TEMPORARILY
HEAVY RATES...AND OBVIOUSLY THATS WHERE CONCERNS ARE REALLY
HEIGHTENED WITH ANY FREEZING RAIN.
GIVEN THE QUICK UPTICK IN INTENSITY OF RAINFALL AND EASTERLY
SURFACE WINDS...HAVE CONTINUED TO KEEP TEMPERATURES SLOW TO WARM
DURING THE DAY. TEMPERATURES STILL SHOULD BE INCHING UP TO OR EVEN
ABOVE FREEZING FROM SOUTH TO NORTH ACROSS THE AREA...BUT THAT
LOOKS LIKE IT WILL LAG THE ONSET OF MODERATE PRECIPITATION AND
THUS CONTINUE WITH FORECAST ICE ACCUMULATION IN THE CWA...NAMELY
THE NORTHERN HALF AWAY FROM THE IMMEDIATE LAKE. FOR AREAS ADJACENT
TO LAKE MICHIGAN...INCLUDING DOWNTOWN CHICAGO...STIFF ONSHORE FLOW
GUSTING TO 40 MPH PLUS /ESPECIALLY NEAR THE LAKE SHORE/ SHOULD
KEEP TEMPERATURES JUST ABOVE FREEZING. TEMPERATURES DO NOT LOOK TO
BE SIGNIFICANTLY BELOW FREEZING WHERE THEY ARE SUB 32...WHICH IS
ONE THING THAT COULD HELP EASE IMPACTS. IF HOWEVER ICE ACCRETION
DOES BEGIN ON LIMBS OR POWER LINES AND OVER SEVERAL HOURS...THE
STRONG WINDS COULD ALLOW FOR HIGHER IMPACTS.
AGAIN IN SUMMARY...THINGS GOING FOR THIS EVENT ARE A STIFF EAST WIND
AND A WIDESPREAD PRECIPITATION SHIELD TO KEEP THE SURFACE
TEMPERATURES FROM WARMING RAPIDLY...OR AT LEAST MORE RAPIDLY THAN
EVEN THE WARMEST GUIDANCE...AND THUS ALLOW FOR WHAT APPEARS TO BE
SEVERAL HOUR DURATION OF FREEZING RAIN. MOST CONCERNED FOR NORTH
CENTRAL ILLINOIS...INCLUDING ROCKFORD...WHERE COLLABORATED ICE
FORECASTS WITH WPC AND ADJACENT WFOS IS PRESENTLY AT OR ABOVE 0.20
OF AN INCH.
TUESDAY STILL LOOKS TO OFFER SOME SNOW POSSIBILITY ON THE
BACKSIDE OF THE SYSTEM...THOUGH WITH IT FILLING AM NOT EXPECTING A
WELL- DEFINED DEFORMATION/WRAPAROUND AS FAR EAST AS THE CWA.
TEMPERATURES LOOK TO EASE DOWN THROUGH THE WEEK INTO UNFAMILIAR
TERRITORY OF BELOW NORMAL BY THE START TO 2016. THERE CONTINUES
TO BE A CHANCE OF SNOW ON WEDNESDAY BUT HAVE GONE WITH A WELL-
VERIFYING MODEL BLEND AT THIS TIME TO FOCUS ON THE PREVIOUS
SYSTEMS.
MTF
&&
.HYDROLOGY...
RAIN DEVELOPING ALONG A STATIONARY FRONT DURING THE DAY
TODAY...AND POSSIBLY HEAVY AT TIMES LATE THIS AFTERNOON TONIGHT...IS
LIKELY TO PERSIST THROUGH EARLY SUNDAY MORNING. THUNDERSTORMS
ALSO ARE POSSIBLE ACROSS SOUTHERN PORTIONS OF THE AREA MAINLY
SOUTH OF THE KANKAKEE RIVER...WHERE WIDESPREAD 1.5 TO 2 INCH
RAINFALL AMOUNTS ARE MOST LIKELY. LOCALIZED AMOUNTS IN EXCESS OF 3
INCHES REMAIN POSSIBLE...THOUGH AT THIS TIME THIS MAY OCCUR JUST
SOUTH OF THE LOCAL AREA. REGARDLESS...THESE RAINFALL AMOUNTS MAY
RESULT IN SIGNIFICANT RISES AND POSSIBLE FLOODING ALONG AREA
RIVERS AND STREAMS...INCLUDING THE IROQUOIS AND KANKAKEE RIVERS AS
WELL AS SUGAR CREEK. IN ADDITION...THE HEAVY RAIN WILL LIKELY
RESULT IN SOME PONDING OF WATER IN LOW LYING AND POOR DRAINAGE
AREAS. SEE THE CURRENT FFALOT FOR MORE DETAILS. THIS APPEARS TO BE
MORE OF A FLOODING SITUATION THAN A TRUE FLASH FLOOD
SITUATION...BUT GIVEN THE CONVECTIVE ELEMENT TO THE PRECIPITATION
AND THE EFFICIENCY OF THE PRECIPITATION EXPECTED TONIGHT AND
SATURATED GROUND...FLOODING COULD OCCUR QUICKLY FOR AREAS STUCK
UNDER HEAVY RAINFALL. THE FLOOD WATCH FOR OUR SOUTHERN COUNTIES WILL
ALSO ACCOUNT FOR ANOTHER 1-1.5 INCHES OF RAINFALL EXPECTED ON
MONDAY.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* RA/SHRA THROUGH EARLY AFTERNOON AND THEN TRANSITIONING OVER TO
DRIZZLE FOR THE EARLY EVENING THROUGH LATE TONIGHT. ANOTHER
POSSIBLE PERIOD OF -RA LATE TONIGHT.
* MVFR CIGS DROPPING TO IFR EARLY THIS EVENING. LIFR CIGS LIKELY
FOR THE LATE EVENING HOURS...BUT IMPROVING TO MVFR DURG THE LATE
NIGHT HOURS.
* EAST WINDS REMAIN ABOVE 10 KT THROUGH LATE AFTERNOON BACKING
NNELY THIS EVENING. WINDS STRENGTHENING AND BECOMING GUSTY TO
ARND 25KT LATE TONIGHT AND TOMORROW.
KREIN
//DISCUSSION...UPDATED 18Z...
A MID LEVEL IMPULSE TRACKING ACROSS THE REGION HAS BROUGHT AN AREA
OF RAIN WITH MVFR CIGS/VIS AND OCNL IFR VIS IN HEAVIER SHOWERS.
SOME ISOLD EMBEDDED TS HAS BEEN OBSERVED WITHIN THE RAIN
AREA...BUT ANY TS HAVE REMAINED SOUTH AND EAST OF THE TERMINALS.
TS POTENTIAL SHOULD END BY 19-20Z AS THE IMPULSE MOVES OFF TO THE
NORTHEAST. MID LEVEL DRY AIR WILL OVERSPREAD THE REGION BEHIND THE
EXITING MID LEVEL IMPULSE...AND RAIN SHOULD TRANSITION OVER TO
DRIZZLE. WITH THE LOWER LEVELS REMAINING VERY MOIST...EXPECT THAT
CIGS/VIS SHOULD LOWER TO PREVAILING IFR BY SUNSET...WITH THE
POTENTIAL FOR LIFR CIGS OVERNIGHT. A MODEST PRESSURE GRADIENT
SHOULD KEEP NNELY WINDS OF 5-10KT THROUGH THE LATE NIGHT
HOURS...SO DO NOT EXPECT DENSE FOG TO FORM. DURG THE EARLY MORNING
HOURS...AS DEEPENING LOW PRESSURE LIFTS NORTHEAST OUT OF ERN
OKLAHOMA THROUGH MISSOURI TOMORROW...EXPECT A STRENGTHENING NNELY
PRESSURE GRADIENT...WITH WINDS GUSTING TO 25KT BY ARND 12Z
TOMORROW MORNING AND SUSTAINED WINDS AND GUSTS LIKELY INCREASING
THROUGH THE DAY TOMORROW AS THE LOW MOVES TO SERN IOWA LATE
TOMORROW AFTERNOON.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE IN PRECIP/VISBY TRENDS.
* HIGH CONFIDENCE IN CIGS DROPPING TO IFR/LIFR...MEDIUM CONFIDENCE
IN TIMING OF IFR/LIFR CIGS.
* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...WINTRY MIX POSSIBLE LATE. MVFR CIGS PSBL.
MONDAY...WINTRY MIX TURNING TO RAIN. MVFR CIGS AND VSBYS.
TUESDAY...MVFR CIGS. CHANCE OF -SN/RA IN THE MORNING.
WEDNESDAY...MVFR CIGS. CHANCE OF -SN.
THURSDAY...MVFR CIGS.
FRIDAY...DRY. VFR.
KMD
&&
.MARINE...
456 AM CST
.HIGH PRESSURE OVER THE NORTHERN LAKES WILL QUICKLY MOVE EAST
TODAY...WHILE LOW PRESSURE DEVELOPS OVER THE SOUTHERN PLAINS. THIS
LOW WILL MOVE QUICKLY NORTHEAST ACROSS THE MIDWEST THIS AFTERNOON
AND INTO NEW ENGLAND BY EARLY SUNDAY. EXPECT WINDS TO RAMP UP
BETWEEN THESE TWO FEATURES RESULTING IN SOME HIGHER WAVES ALONG
THE ILLINOIS SIDE TODAY. STRONG HIGH PRESSURE OVER THE UPPER
MIDWEST EXTENDING INTO SOUTHERN MANITOBA WILL BUILD EAST ACROSS
ONTARIO LATE IN THE WEEKEND...WHILE ANOTHER DEEP LOW DEVELOPS
ACROSS TEXAS. AHEAD OF THE STRONG HIGH...A SURGE OF NORTH WINDS TO
30 KT...POSSIBLY A FEW GALE GUSTS...WILL OCCUR LATE TONIGHT INTO
SUNDAY.
THIS SECOND LOW WILL THEN DEEPEN OVER THE LOWER MISSOURI VALLEY
MONDAY MORNING...THEN WILL LIFT NORTHEAST ACROSS WESTERN GREAT
LAKES BY EARLY TUESDAY BEFORE FILLING. THE GRADIENT BETWEEN THIS
LOW AND THE VERY STRONG HIGH WHICH ONLY SLOWLY MOVES EAST WILL
RESULT IN A PERIOD OF STRONG GALES MONDAY...POSSIBLY WITH A FEW
STORM FORCE WIND GUSTS ALONG WITH COASTAL FLOODING ISSUES ALONG
THE ILLINOIS NEARSHORE. ANOTHER WEAK LOW WILL MOVE OVER THE
NORTHERN HALF OF THE LAKE WEDNESDAY FOLLOWED BY COOL HIGH
PRESSURE.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ033-ILZ039...6 PM SATURDAY TO 6 PM MONDAY.
IN...FLASH FLOOD WATCH...INZ010-INZ011-INZ019...6 PM SATURDAY TO 6 PM
MONDAY.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 6 PM SATURDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1129 AM CST SAT DEC 26 2015
.UPDATE...
1108 AM CST
TSRA COVERAGE SEEMS TO BE ON A DOWNWARD TREND LATE THIS MORNING
AFTER A LITTLE MORE ACTIVITY SOUTH AND WEST THAN MIGHT HAVE BEEN
EXPECTED EARLIER TODAY. FOCUS FOR ADDITIONAL TSRA WILL SHIFT
WELL SOUTH OF THE CHICAGO METRO AREA MAINLY TO PORTIONS OF NW
INDIANA ALONG WITH THE ANTICIPATED AXIS OF HEAVIER RAINFALL. MAY
EVEN BE ABLE TO LOWER POPS IN NORTHERN PORTIONS OF THE AREA TOWARD
ROCKFORD AND THE WI LINE THIS AFTERNOON...OR CARRY JUST A MENTION
OF DRIZZLE. EVEN IN THE CHICAGO METRO AREA...DRIZZLE MIGHT BE THE
MAIN WEATHER TYPE THIS AFTERNOON AS THE LATEST AMDAR SOUNDINGS OUT
OF MDW ARE SHOWING JUST A RELATIVELY SHALLOW SATURATED LAYER TO
ABOUT 850 MB WITH DRY AIR ABOVE THAT. THIS ALSO CORRESPONDS TO
WHAT THE RAP IS SHOWING...WITH AN INCREASINGLY SHALLOW SATURATED
LAYER AS THE AFTERNOON PROGRESSES.
WINDS WILL RELAX THIS AFTERNOON AND TONIGHT BEFORE PICKING UP
CONSIDERABLY AGAIN TOMORROW MORNING.
LENNING
&&
.SHORT TERM...
411 AM CST
THROUGH TONIGHT...
FOCUS IS ON MODERATE TO LOCALLY HEAVY RAINFALL LATE THIS AFTERNOON
THROUGH TONIGHT.
DEEP UPPER LEVEL LOW PRESSURE CONTINUES TO STRENGTHEN OVER THE
DESTER SOUTHWEST...WITH STRONG AND UNSEASONABLY MOIST/WARM
ADVECTION OCCURRING OUT AHEAD OF THE LOW. SEVERAL COMPLEXES OF
THUNDERSTORMS ARE ONGOING IN THE WARM ADVECTIVE REGIME NORTH OF A
WARM FRONTAL BOUNDARY DRAPED FROM THE ARKLATEX REGION THEN
NORTHEAST INTO THE TENNESSEE VALLEY IN AN AREA OF ELEVATED MID
LEVEL LAPSE RATES. AN ADDITIONAL AREA OF PRECIPITATION IS
OCCURRING NORTH OF AN INVERTED SURFACE TROUGH.
THIS WARM/MOIST BOUNDARY CONTINUES TO ADVECT NORTHWARD THIS
MORNING WITH A PLUME OF NEAR RECORD PRECIPITABLE WATER VALUES.
WITH COOL NORTHEAST WINDS IN PLACE AHEAD ANCHORING THE LOW LEVEL
FRONTAL BOUNDARY TO OUR SOUTH WILL CREATE A RECIPE FOR LOW CLOUDS
TO OVERSPREAD THE AREA THIS MORNING...AS FORECAST SOUNDINGS
DEPICT RAPID SATURATION OF THE LOWER LEVELS WHICH HAS BEEN
OCCURRING DOWNSTATE. AS CLOUDS LOWER...EXPECT SOME FOG TO DEVELOP
AS WELL.
THE INVERTED TROUGH AXIS SHIFTS AND IS POINTED AT OUR AREA AROUND
MIDDAY. AS THIS OCCURS IN CONJUNCTION WITH ISENTROPIC
ASCENT...EXPECT AN INCREASE IN INITIALLY LIGHTER RAIN SHOWERS THIS
MORNING DUE TO LACK OF DEEPER SATURATION...THEN AS FORCING
INCREASES AHEAD OF A NORTHERN STREAM SHORTWAVE...STRENGTHENING
UPPER LEVEL JET MAXIMUM TO OUR NORTHWEST...AND A STRONG LOW TO MID
LEVEL FRONTOGENESIS OCCURRING DUE TO THE AIRMASS CLASH...EXPECT
SHOWERS TO BLOSSOM THIS AFTERNOON AND EVENING. PRECIPITATION MAY
DWINDLE TO LIGHTER RAIN/DRIZZLE FARTHER NORTH...BUT THERE ARE
ADDITIONAL WAVES THAT WILL RIDE ALONG THE LOW AND ELEVATED
BAROCLINIC ZONES TO KEEP A MENTION OF RAIN GOING AREA-WIDE TONIGHT.
THE FRONT LOOKS TO BE MOST ACTIVE ALONG OUR SOUTHERN COUNTIES
WHERE EXTREME FRONTOGENESIS COMBINED WITH THE RECORD PWATS WILL
LEAD TO PERIODS OF MODERATE TO HEAVY RAINFALL. THUNDER IS
CERTAINLY POSSIBLE EVEN AS FAR NORTH AS CHICAGO OR LAKE MICHIGAN
AS THE PLUME OF ELEVATED LAPSE RATES SPREADS OVERHEAD...BUT MORE
LIKELY FARTHER SOUTH CLOSER TO THE STRONGER COMBINED FORCING.
THERE LOOKS TO BE A VERY TIGHT GRADIENT IN THE HEAVY PRECIP AXIS.
HAVE ELECTED TO ISSUE A FLOOD WATCH SIMILAR TO OUR NEIGHBORS DUE
TO THIS POTENTIAL GIVEN THE CONVECTIVE ELEMENTS PRESENT. THERE IS
STILL WITH SOME UNCERTAINTY AS TO IF THIS WILL REMAIN SOUTH OF THE
AREA AS SUGGESTED BY SOME HI-RES GUIDANCE MEMBERS. HAVE CARRIED
THIS WATCH OUT THROUGH THE SECOND EVENT (LONG TERM)...THOUGH THERE
WILL BE A GAP ON SUNDAY. MORE ON THIS IN THE HYDROLOGY SECTION
FORTHCOMING.
KMD
&&
.LONG TERM...
333 AM CST
SUNDAY THROUGH FRIDAY...
THE FOCUS ON THE LONGER RANGE FORECAST IS CERTAINLY WITH THE SUNDAY
NIGHT THROUGH MONDAY NIGHT PRECIPITATION EVENT...WHICH IS TRENDING
MORE TOWARD A RAIN/FREEZING RAIN EVENT. THIS STILL LOOKS TO BE LARGE
CONCERNS OF ICING FROM FREEZING RAIN FOR AT LEAST A PORTION OF THE
AREA...ESPECIALLY AREAS ALONG AND NORTH OF I-80. THERE ALSO IS
CONCERNS THAT THE AMOUNT OF RAIN /WHETHER INITIALLY FREEZING OR NOT/
COULD CAUSE LOCALIZED FLOODING ISSUES AS MONDAY PROGRESSES AND
CERTAINLY SOME QUICK RIVER RISES. IT IS A BIT CLEARER PICTURE THAT
THE POTENTIAL FOR SNOW IS LESS LIKELY THROUGH MONDAY NIGHT. HAVE
ADDED A LITTLE MORE DETAIL IN THE FORECAST...BUT OVERALL KEPT SOME
RANGE OF UNCERTAINTY DUE TO THE SPECIFIC SURFACE TEMPERATURE
FORECASTS AS WELL AS THE LARGER SCALE EXACT TRACK OF THE SYSTEM.
LAST EVENINGS RAOBS INDICATED A STRONG JET STREAM MAXIMUM OF AROUND
150 KT DIGGING SOUTH ACROSS THE WESTERN U.S. WHICH WILL CUT OFF A
CLOSED LOW ACROSS THE DESERT SOUTHWEST/MEXICO BORDER BY TONIGHT.
THIS WILL EVOLVE NORTHEAST IN RESPONSE TO ANOTHER JET MAXIMUM
DIGGING UPSTREAM. A CUTOFF FEATURE SUCH AS THIS LOW AND BEING
FAIRLY FAR SOUTH IN LATITUDE TENDS TO END UP BEING SLOWER THAN A
MEAN MODEL SOLUTION AND WE HAVE SEEN THAT OVER THE PAST COUPLE
MONTHS WITH SYSTEMS LOCATED EVEN FURTHER NORTH. SUCH A SLOWER
EVOLUTION WOULD RESULT IN A FURTHER WEST TRACK AS THE SYSTEM LIFTS
NORTHEAST WHICH IS ADVERTISED BY THE PREFERRED EC...NAM...AND
SREF MORE SO THAN THE GFS...ITS ENSEMBLE...AND THE GEM. THE
OVERALL TREND IN A MEAN OF ALL THESE GUIDANCE HAS ALSO SHIFTED
SLIGHTLY SLOWER AND FURTHER WEST WITH THIS SYSTEM...FURTHER
SUPPORTING LEANING THIS ROUTE. IN ADDITION...THE STRONG CANADIAN
HIGH PRESSURE OVER THE NORTHERN PLAINS THAT COULD OFFER SOME
BLOCKING AND SUPPORT A FURTHER EAST TRACK IN THE LOW IS TRENDING
SLIGHTLY FURTHER NORTH...AGAIN FAVORING LEANING WEST.
FOR SUNDAY...LOW-LEVEL COLD ADVECTION ON GUSTY NORTHERLY WINDS
WILL BE UNDERCUTTING THE ELEVATED BAROCLINIC ZONE AND EXPECT
TEMPERATURES TO REMAIN IN THE 30S BUT FEELING EVEN COLDER. THERE
PROBABLY WILL BE LAKE EFFECT CLOUDS AND MAYBE EVEN SOME DRIZZLE
FROM THAT DURING THE MORNING INTO CHICAGO AND OTHER LAKE ADJACENT
AREAS. AS FOR THE PREVAILING RAIN IN THE SOUTHERN AND EASTERN
FORECAST AREA SUNDAY MORNING...THAT SHOULD EASE SOUTHEASTWARD IN
THE AFTERNOON AS FRONTOGENESIS TEMPORARILY WEAKENS.
THE WARM AND MOIST ADVECTION ALOFT GRADUALLY STRENGTHENS SUNDAY
EVENING IN RESPONSE TO THE UPPER LOW APPROACHING AND REALLY RAMPS UP
EITHER LATE THAT NIGHT OR MONDAY MORNING OVER THE AREA. THE NAM
IS THE SLOWEST ADVANCING ITS PRECIPITATION AND IF CORRECT WOULD
INDICATE NOT MUCH IN THE AREA PRIOR TO DAYBREAK MONDAY...BUT HAVE
LEANED A LITTLE QUICKER THAN ITS SOLUTION GIVEN THE STRENGTH OF
THE MOISTURE ADVECTION.
EASTERLY SURFACE WINDS WILL STRENGTHEN OVERNIGHT GIVEN THE
PRESSURE GRADIENT RAPIDLY TIGHTENING. THIS ALONG WITH CLOUDS
SHOULD KEEP TEMPERATURES FAIRLY STEADY...THOUGH AS MENTIONED IN
PRIOR AFD THAT AT PRECIP ONSET...WHETHER LATE SUNDAY NIGHT OR
MONDAY MORNING...MAY RESULT IN A COUPLE DEGREE TEMPERATURE DROP.
THIS COULD MEAN A WINDOW OF SOME SLEET BUT OVERALL NOT EXPECTING
THAT TO BE THE DOMINANT TYPE OF PRECIPITATION FOR ANY EXTENDED
PERIOD. WITH BIG TIME UPPER SUPPORT FOR LIFT...PRECIPITATION
SHOULD BE AT ITS MAXIMUM COVERAGE AND INTENSITY DURING THE DAY
MONDAY AND AT LEAST EARLY MONDAY EVENING...IF NOT MUCH OF IT.
MIXING RATIOS OF 6-8 G/KG SHOULD SUPPORT MODEST IF NOT TEMPORARILY
HEAVY RATES...AND OBVIOUSLY THATS WHERE CONCERNS ARE REALLY
HEIGHTENED WITH ANY FREEZING RAIN.
GIVEN THE QUICK UPTICK IN INTENSITY OF RAINFALL AND EASTERLY
SURFACE WINDS...HAVE CONTINUED TO KEEP TEMPERATURES SLOW TO WARM
DURING THE DAY. TEMPERATURES STILL SHOULD BE INCHING UP TO OR EVEN
ABOVE FREEZING FROM SOUTH TO NORTH ACROSS THE AREA...BUT THAT
LOOKS LIKE IT WILL LAG THE ONSET OF MODERATE PRECIPITATION AND
THUS CONTINUE WITH FORECAST ICE ACCUMULATION IN THE CWA...NAMELY
THE NORTHERN HALF AWAY FROM THE IMMEDIATE LAKE. FOR AREAS ADJACENT
TO LAKE MICHIGAN...INCLUDING DOWNTOWN CHICAGO...STIFF ONSHORE FLOW
GUSTING TO 40 MPH PLUS /ESPECIALLY NEAR THE LAKE SHORE/ SHOULD
KEEP TEMPERATURES JUST ABOVE FREEZING. TEMPERATURES DO NOT LOOK TO
BE SIGNIFICANTLY BELOW FREEZING WHERE THEY ARE SUB 32...WHICH IS
ONE THING THAT COULD HELP EASE IMPACTS. IF HOWEVER ICE ACCRETION
DOES BEGIN ON LIMBS OR POWER LINES AND OVER SEVERAL HOURS...THE
STRONG WINDS COULD ALLOW FOR HIGHER IMPACTS.
AGAIN IN SUMMARY...THINGS GOING FOR THIS EVENT ARE A STIFF EAST WIND
AND A WIDESPREAD PRECIPITATION SHIELD TO KEEP THE SURFACE
TEMPERATURES FROM WARMING RAPIDLY...OR AT LEAST MORE RAPIDLY THAN
EVEN THE WARMEST GUIDANCE...AND THUS ALLOW FOR WHAT APPEARS TO BE
SEVERAL HOUR DURATION OF FREEZING RAIN. MOST CONCERNED FOR NORTH
CENTRAL ILLINOIS...INCLUDING ROCKFORD...WHERE COLLABORATED ICE
FORECASTS WITH WPC AND ADJACENT WFOS IS PRESENTLY AT OR ABOVE 0.20
OF AN INCH.
TUESDAY STILL LOOKS TO OFFER SOME SNOW POSSIBILITY ON THE
BACKSIDE OF THE SYSTEM...THOUGH WITH IT FILLING AM NOT EXPECTING A
WELL- DEFINED DEFORMATION/WRAPAROUND AS FAR EAST AS THE CWA.
TEMPERATURES LOOK TO EASE DOWN THROUGH THE WEEK INTO UNFAMILIAR
TERRITORY OF BELOW NORMAL BY THE START TO 2016. THERE CONTINUES
TO BE A CHANCE OF SNOW ON WEDNESDAY BUT HAVE GONE WITH A WELL-
VERIFYING MODEL BLEND AT THIS TIME TO FOCUS ON THE PREVIOUS
SYSTEMS.
MTF
&&
.HYDROLOGY...
RAIN DEVELOPING ALONG A STATIONARY FRONT DURING THE DAY
TODAY...AND POSSIBLY HEAVY AT TIMES LATE THIS AFTERNOON TONIGHT...IS
LIKELY TO PERSIST THROUGH EARLY SUNDAY MORNING. THUNDERSTORMS
ALSO ARE POSSIBLE ACROSS SOUTHERN PORTIONS OF THE AREA MAINLY
SOUTH OF THE KANKAKEE RIVER...WHERE WIDESPREAD 1.5 TO 2 INCH
RAINFALL AMOUNTS ARE MOST LIKELY. LOCALIZED AMOUNTS IN EXCESS OF 3
INCHES REMAIN POSSIBLE...THOUGH AT THIS TIME THIS MAY OCCUR JUST
SOUTH OF THE LOCAL AREA. REGARDLESS...THESE RAINFALL AMOUNTS MAY
RESULT IN SIGNIFICANT RISES AND POSSIBLE FLOODING ALONG AREA
RIVERS AND STREAMS...INCLUDING THE IROQUOIS AND KANKAKEE RIVERS AS
WELL AS SUGAR CREEK. IN ADDITION...THE HEAVY RAIN WILL LIKELY
RESULT IN SOME PONDING OF WATER IN LOW LYING AND POOR DRAINAGE
AREAS. SEE THE CURRENT FFALOT FOR MORE DETAILS. THIS APPEARS TO BE
MORE OF A FLOODING SITUATION THAN A TRUE FLASH FLOOD
SITUATION...BUT GIVEN THE CONVECTIVE ELEMENT TO THE PRECIPITATION
AND THE EFFICIENCY OF THE PRECIPITATION EXPECTED TONIGHT AND
SATURATED GROUND...FLOODING COULD OCCUR QUICKLY FOR AREAS STUCK
UNDER HEAVY RAINFALL. THE FLOOD WATCH FOR OUR SOUTHERN COUNTIES WILL
ALSO ACCOUNT FOR ANOTHER 1-1.5 INCHES OF RAINFALL EXPECTED ON
MONDAY.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* RA/SHRA DEVELOP LATER THIS MORNING...LIKELY TAPER TO DZ
LATE...WITH ANOTHER POSSIBLE PERIOD OF -RA OVERNIGHT.
* VERY SLIGHT CHANCE EMBEDDED TS WITH THE -SHRA TODAY.
* MVFR CIGS QUICKLY DROPPING TO IFR/LIFR LATE THIS MORNING WITH
FOG POSSIBLE.
* EAST WINDS GUSTING TO AROUND 20 KT THIS MORNING. EAST WINDS
REMAIN ABOVE 10 KT THROUGH MID AFTERNOON THEN SHIFT NNE AND
INCREASING AGAIN LATE TONIGHT.
KREIN
//DISCUSSION...UPDATED 12Z...
LOW CLOUDS CONTINUE TO SPREAD NORTH OF WARM FRONTAL BOUNDARY
DRAPED WELL SOUTH OF THE AREA. UPSTREAM OBS SUGGEST A BRIEF PERIOD
OF MVFR FOLLOWED BY A CONTINUED DETERIORATION TO IFR AND THEN LIFR
THROUGH THE MORNING AND EARLY AFTERNOON. MEAWNWHILE...EAST WINDS
ARE RAMPING UP AS HIGH PRESSURE DEPARTS EAST AND A LOW LEVEL
TROUGH AXIS SHIFTS NORTH AND EAST. THE CENTER OF LOW PRESSURE WILL
PASS SOUTH OF THE TERMINALS THIS EVENING AND EAST
OVERNIGHT...RESULTING IN A SHIFT TO NORTH WINDS WITH AN INCREASE
IN INTENSITY AS STRONG HIGH PRESSURE BUILDS SOUTH FROM CANADA.
REGARDING PRECIPITATION...SEVERAL WAVES ARE EXPECTED. THE FIRST
BEING LATER THIS MORNING/EARLY AFTERNOON AS WARM/MOIST ADVECTION
INCREASES. THE AREA OF SHOWERS AND THUNDERSTORMS LOOKS OVER
MISSOURI APPEARS TO BE THE FIRST WAVE...BUT LOW CONFIDENCE ON TS
OCCURRENCE AT THE TERMINALS. LAPSE RATES ALOFT ARE ELEVATED ENOUGH
TO SUPPORT IT SO CERTAINLY A POSSIBILITY BUT NOT IN THE TAF AT THE
MOMENT. CIGS THEN STAY DOWN MOST OF THE NIGHT AND LIKELY SOME
VSBY REDUCTIONS AS WELL. FEEL PRETTY CONFIDENT THAT THERE WILL BE
A PERIOD OF 1SM VSBY REDUCTIONS...WITH SOME GUIDANCE HINTING A BIT
LOWER...SO THIS WILL BEAR MONITORING. ADDITIONAL BOUTS OF MODERATE
TO HEAVY RAINFALL ARE EXPECTED THIS EVENING AS THE LOW LEVEL
THERMAL ZONE STRENGHTENS...WITH THE AXIS SHIFTING SOUTHEAST AS THE
NIGHT GOES ON. GUSTY NE WINDS PERSIST INTO SUNDAY MORNING WITH
SOME SLIGHT LIFTING TO CIGS.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE IN PRECIP TRENDS TODAY.
* LOW CONFIDENCE IN TS OCCURRENCE AT THE TERMINALS.
* HIGH CONFIDENCE IN CIGS DROPPING TO IFR/LIFR...MEDIUM CONFIDENCE
IN TIMING OF IFR CIGS +/- A COUPLE HOURS.
* LOW CONFIDENCE IN HOW LOW VSBY WILL DROP IN FOG TODAY.
* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...WINTRY MIX POSSIBLE LATE. MVFR CIGS PSBL.
MONDAY...WINTRY MIX TURNING TO RAIN. MVFR CIGS AND VSBYS.
TUESDAY...MVFR CIGS. CHANCE OF -SN/RA IN THE MORNING.
WEDNESDAY...MVFR CIGS. CHANCE OF -SN.
THURSDAY...MVFR CIGS.
FRIDAY...DRY. VFR.
KMD
&&
.MARINE...
456 AM CST
.HIGH PRESSURE OVER THE NORTHERN LAKES WILL QUICKLY MOVE EAST
TODAY...WHILE LOW PRESSURE DEVELOPS OVER THE SOUTHERN PLAINS. THIS
LOW WILL MOVE QUICKLY NORTHEAST ACROSS THE MIDWEST THIS AFTERNOON
AND INTO NEW ENGLAND BY EARLY SUNDAY. EXPECT WINDS TO RAMP UP
BETWEEN THESE TWO FEATURES RESULTING IN SOME HIGHER WAVES ALONG
THE ILLINOIS SIDE TODAY. STRONG HIGH PRESSURE OVER THE UPPER
MIDWEST EXTENDING INTO SOUTHERN MANITOBA WILL BUILD EAST ACROSS
ONTARIO LATE IN THE WEEKEND...WHILE ANOTHER DEEP LOW DEVELOPS
ACROSS TEXAS. AHEAD OF THE STRONG HIGH...A SURGE OF NORTH WINDS TO
30 KT...POSSIBLY A FEW GALE GUSTS...WILL OCCUR LATE TONIGHT INTO
SUNDAY.
THIS SECOND LOW WILL THEN DEEPEN OVER THE LOWER MISSOURI VALLEY
MONDAY MORNING...THEN WILL LIFT NORTHEAST ACROSS WESTERN GREAT
LAKES BY EARLY TUESDAY BEFORE FILLING. THE GRADIENT BETWEEN THIS
LOW AND THE VERY STRONG HIGH WHICH ONLY SLOWLY MOVES EAST WILL
RESULT IN A PERIOD OF STRONG GALES MONDAY...POSSIBLY WITH A FEW
STORM FORCE WIND GUSTS ALONG WITH COASTAL FLOODING ISSUES ALONG
THE ILLINOIS NEARSHORE. ANOTHER WEAK LOW WILL MOVE OVER THE
NORTHERN HALF OF THE LAKE WEDNESDAY FOLLOWED BY COOL HIGH
PRESSURE.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ033-ILZ039...6 PM SATURDAY TO 6 PM MONDAY.
IN...FLASH FLOOD WATCH...INZ010-INZ011-INZ019...6 PM SATURDAY TO 6 PM
MONDAY.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 6 PM SATURDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS JACKSON KY
358 PM EST SAT DEC 26 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 300 PM EST SAT DEC 26 2015
19Z SFC ANALYSIS SHOWS DEEP LOW PRESSURE OFF TO THE SOUTHWEST OF
THE AREA WITH A WARM FRONT NOW LIFTING INTO AND THOUGH KENTUCKY.
SOME HEALTHY SHOWERS AND A FEW THUNDERSTORMS ARE BEING PUSHED
NORTH THROUGH THE AREA AHEAD OF THIS BOUNDARY. THE STRONGER
PORTIONS OF THIS CLUSTER IS FOUND JUST TO THE WEST OF THE JKL
CWA...BUT THE ENTIRE AREA IS PROGRESSIVE ENOUGH TO LIMIT ANY
RENEWED FLOODING CONCERNS FOR NORTHERN PARTS OF OUR AREA OF
RESPONSIBILITY. FOR THE SOUTHEAST PART OF EASTERN KENTUCKY THE
CLOUDS ARE SCATTERING OUT ALLOWING FOR MORE SUNSHINE WHILE THE
NORTHWEST REMAINS FAIRLY CLOUDY. THIS IS HAVING AN EFFECT ON
TEMPERATURES ACROSS WITH THE SOUTHEAST REACHING NEAR 70 DEGREES
WHILE THE NORTHWEST STILL HAS A FEW LOCATIONS IN THE UPPER 50S.
JKL HAS ALREADY SMASHED ITS RECORD HIGH FOR THE DAY...BUT LOZ MAY
NEED SOME GOOD CLOUD BREAKS TO EXCEED ITS RECORD. DEWPOINTS ALSO
VARY FROM SOUTHEAST TO NORTHWEST WITH LOWER 60S CLOSER TO
TENNESSEE AND VIRGINIA WHILE MID 50S ARE FOUND NORTH OF INTERSTATE
64. WINDS...MEANWHILE...ARE GENERALLY LIGHT FROM THE SOUTH TO
SOUTHEAST.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM.
THEY ALL DEPICT THE ANOMALOUSLY DEEP TROUGH CLOSING OFF ABOVE
NORTHERN MEXICO THIS EVENING HELPING TO PUMP THE SOUTHEAST RIDGE
DOWNSTREAM OVER KENTUCKY. ON SUNDAY...THE MODELS ROLL THIS UPPER
LOW INTO CENTRAL TEXAS WITH THE NAM SLIGHTLY STRONGER AND FURTHER
NORTH THAN THE GFS AND LATEST ECMWF. FOR KENTUCKY THIS YIELDS
HEIGHTS A SMIDGE HIGHER HEADING INTO SUNDAY NIGHT. THE GFS IS MORE
PROGRESSIVE WITH THE UPPER LOW INTO MONDAY MORNING WHILE THE ECMWF
AND NAM ARE IN BETTER AGREEMENT WITH A SLOWER MOVEMENT....REACHING
SOUTH CENTRAL OKLAHOMA BY 12Z VERSUS THE GFS POSITION OF THE LOW
CROSSING INTO ARKANSAS. HEIGHT DIFFERENCES REMAIN FOR EASTERN
KENTUCKY DOWNSTREAM WITH THE NAM/ECMWF ABOUT 30 DECAMETERS HIGHER
THAN THE GFS SOLUTION. THE BETTER AGREEMENT BETWEEN THE MORE
CONSISTENT ECMWF AND NAM LEND SUPPORT TO FAVORING THE NAM12 ON WX
DETAILS FOR THE SHORT TERM...IN CONJUNCTION WITH THE HRRR EARLY
ON.
SENSIBLE WEATHER WILL FEATURE THE MAJORITY OF ANY PCPN LIFTING
NORTH OF THE AREA BY EVENING WITH JUST A FEW STRAY SHOWERS
POSSIBLE INTO THE NIGHT...MAINLY CONFINED TO THE NORTHERN PARTS OF
THE AREA. GIVEN THE POSITION OF THE PCPN AND THICKER CLOUDS...
EXPECT A SMALL TO MODERATE RIDGE AND VALLEY SPLIT TO DEVELOP FOR
AT LEAST THE SOUTHERN 2/3RDS OF THE CWA. PATCHY VALLEY FOG WILL
ALSO BE POSSIBLE IN PLACES THAT HAVE THE THINNEST CLOUDS. FOR
SUNDAY...OUR WARMEST TEMPERATURES EVER RECORDED FOR DECEMBER
COULD BE THREATENED...DEPENDING ON THE QUALITY OF THE SUNSHINE
SEEN. HIGHS SHOULD EASILY BE IN THE MID 70S WITH UPPER 70S
POSSIBLE. DECEMBER/S RECORD HIGH FOR JKL IS 79 AND LOZ IS 78...
CERTAINLY WITHIN THE REALM OF POSSIBILITIES. ANY CONVECTION IN
THE WARM SECTOR SOUTH OF THE FRONT...LYING NORTH OF THE OHIO
RIVER...COULD END UP AS A THUNDERSTORM PARTICULARLY FOR LOCATIONS
NORTH OF THE MOUNTAIN PARKWAY. FOR SUNDAY AFTERNOON AND EVENING...
THE FRONT WILL START TO SHIFT SOUTH IN RESPONSE TO THE DEVELOPING
SFC LOW TO THE WEST. THIS WILL BRING A THREAT OF CONVECTION AND
HEAVY/TRAINING RAINS BACK INTO AT LEAST THE NORTHERN PARTS OF THE
AREA. THAT NIGHT THE CONVECTION WITH THE FRONT SHOULD WEAKEN AS
THE LOW APPROACHES WITH A STRIATION TO LOW TEMPERATURES DUE TO THE
WAGGLE OF THE BOUNDARY WITH SOME UPPER 40S POSSIBLE NORTH WHILE
THE SOUTH SETTLES INTO THE MID AND UPPER 50S.
FOR TEMPERATURES AND DEWPOINTS...AGAIN STARTED WITH THE SHORTBLEND
GUIDANCE THROUGH SUNDAY MORNING AND THEN THE SUPERBLEND INTO
MONDAY MORNING. MADE MORE SIGNIFICANT CHANGES TO THE LOWS TONIGHT
WITH A BETTER CHANCE FOR A RIDGE AND VALLEY DISTINCTION THROUGH
THE NIGHT FOR MUCH OF THE AREA. AS FOR POPS...ENDED UP CLOSER TO
THE WETTER MET NUMBERS FOR SUNDAY AND SUNDAY NIGHT.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 358 PM EST SAT DEC 26 2015
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE PERIOD...WITH AN
AMPLIFIED PATTERN TO CONTINUE. A DEEP CUT OFF LOW WILL START OUT
ON MONDAY DOWN IN THE ARKLATEX REGION. THIS WILL SWING NORTHEAST
INTO THE GREAT LAKES BY MONDAY NIGHT...WITH ANOTHER SHORT WAVE
TROUGH DIGGING ACROSS THE DESERT SOUTHWEST AND THEN LIFTING
NORTHEAST ACROSS THE PLAINS AND EVENTUALLY THROUGH THE OHIO VALLEY
BY MID-WEEK. THE NORTHERN STREAM FINALLY MAKES A COMEBACK ACROSS
THE OHIO/TENNESSEE VALLEYS TOWARDS THE NEW YEAR...FINALLY BREAKING
THE WAY ABOVE NORMAL READINGS WE HAVE BEEN SEEING FOR THE PAST 1
TO 2 WEEKS.
A SURFACE COLD FRONT WILL BE SWINGING THROUGH EASTERN KENTUCKY
LATE IN THE DAY ON MONDAY AND INTO MONDAY NIGHT. INSTABILITY
CONTINUES TO LOOK WEAK...SO WILL KEEP JUST A SLIGHT CHANCE OF
THUNDER GOING. THE PROGRESSIVE NATURE OF THE COLD FRONT WILL KEEP
SHORT FUSE HYDRO PROBLEMS IN CHECK...BUT WILL LIKELY KEEP LARGER
CREEKS AND RIVERS UP. ONCE THE MAIN FRONT EXITS ON TUESDAY...A
SECONDARY SURGE OF MOISTURE AND FORCING WILL ARRIVE ON THE
EXISTING BAROCLINIC ZONE NEARBY OR JUST TO OUR SOUTHEAST. THE
ECMWF AND GFS DIFFER ON THE NORTHERN EXTENT OF THE FORCING AND
MOISTURE ON WEDNESDAY...BUT THE BLENDED POPS HAVE OVERALL BEEN
TRENDING HIGHER. HAVE FOLLOWED SUIT FOR NOW...BUT THERE IS LESS
CONFIDENCE IN THE QPF AMOUNTS AT THIS POINT. AS SUCH...WILL FOCUS
THE CONTINUATION OF THE ESF FOR EARLY NEXT WEEK...AND BECOME MORE
GENERALIZED WITH THE UNCERTAINTY FOR THE MIDDLE OF NEXT WEEK.
BY THURSDAY...THINGS LOOK TO FINALLY DRY OUT AS SURFACE RIDGING
NOSES IN FROM THE SOUTHWEST. MUCH COLDER AIR WILL ALSO BE MOVING
BACK IN BY THE END OF THE WORK WEEK AND INTO NEXT WEEKEND...BUT
NOT COUPLED WITH DEEPER MOISTURE...SO NO MORE MEASURABLE SNOW FOR
THE END OF THE YEAR CONTINUES TO LOOK VERY LIKELY. HIGHS WILL
DROP BACK INTO THE UPPER 30S AND LOWER 40S FOR MOST LOCATIONS BY
FRIDAY AND SATURDAY...WITH LOWS IN THE 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 150 PM EST SAT DEC 26 2015
A DEVELOPING WARM FRONT PUSHING INTO THE AREA IS LIFTING MOST OF
THE CONVECTION NORTH ALONG WITH IT. THIS IS BRUSHING THE LOZ AND
JKL TAF SITES AFTER DEPARTING SME. SYM WILL BE DEALING WITH THIS
AREA FOR THE LONGEST TIME INTO THE EARLY EVENING WHILE SJS MAY
MISS IT ALL TOGETHER AS THE MAIN PCPN STAYS TO THE WEST. WITH THIS
CONVECTION MVFR CIGS WILL BE POSSIBLE...ALONG WITH VIS AS LOW AS
IFR. HOWEVER...THIS ALL SHOULD LIFT FURTHER NORTH WITH TIME AND
SPARE THE AIRPORTS ACROSS EAST KENTUCKY MUCH IN THE WAY OF PCPN
THROUGH THE NIGHT AND INTO THE DAY SUNDAY. ACCORDINGLY...
CONDITIONS WILL BE MAINLY VFR THROUGH THE REST OF THE TAF
CYCLE...THOUGH SOME PATCHY FOG MAY BRING MVFR VIS TO THE SME AND
LOZ SITES IN THE EARLY MORNING HOURS. WINDS FOR THE AREA WILL BE
LIGHT AND VARIABLE THROUGH THE PERIOD...MAINLY FAVORING THE SOUTH
DIRECTION.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...GEOGERIAN
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
300 PM EST SAT DEC 26 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 300 PM EST SAT DEC 26 2015
19Z SFC ANALYSIS SHOWS DEEP LOW PRESSURE OFF TO THE SOUTHWEST OF
THE AREA WITH A WARM FRONT NOW LIFTING INTO AND THOUGH KENTUCKY.
SOME HEALTHY SHOWERS AND A FEW THUNDERSTORMS ARE BEING PUSHED
NORTH THROUGH THE AREA AHEAD OF THIS BOUNDARY. THE STRONGER
PORTIONS OF THIS CLUSTER IS FOUND JUST TO THE WEST OF THE JKL
CWA...BUT THE ENTIRE AREA IS PROGRESSIVE ENOUGH TO LIMIT ANY
RENEWED FLOODING CONCERNS FOR NORTHERN PARTS OF OUR AREA OF
RESPONSIBILITY. FOR THE SOUTHEAST PART OF EASTERN KENTUCKY THE
CLOUDS ARE SCATTERING OUT ALLOWING FOR MORE SUNSHINE WHILE THE
NORTHWEST REMAINS FAIRLY CLOUDY. THIS IS HAVING AN EFFECT ON
TEMPERATURES ACROSS WITH THE SOUTHEAST REACHING NEAR 70 DEGREES
WHILE THE NORTHWEST STILL HAS A FEW LOCATIONS IN THE UPPER 50S.
JKL HAS ALREADY SMASHED ITS RECORD HIGH FOR THE DAY...BUT LOZ MAY
NEED SOME GOOD CLOUD BREAKS TO EXCEED ITS RECORD. DEWPOINTS ALSO
VARY FROM SOUTHEAST TO NORTHWEST WITH LOWER 60S CLOSER TO
TENNESSEE AND VIRGINIA WHILE MID 50S ARE FOUND NORTH OF INTERSTATE
64. WINDS...MEANWHILE...ARE GENERALLY LIGHT FROM THE SOUTH TO
SOUTHEAST.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM.
THEY ALL DEPICT THE ANOMALOUSLY DEEP TROUGH CLOSING OFF ABOVE
NORTHERN MEXICO THIS EVENING HELPING TO PUMP THE SOUTHEAST RIDGE
DOWNSTREAM OVER KENTUCKY. ON SUNDAY...THE MODELS ROLL THIS UPPER
LOW INTO CENTRAL TEXAS WITH THE NAM SLIGHTLY STRONGER AND FURTHER
NORTH THAN THE GFS AND LATEST ECMWF. FOR KENTUCKY THIS YIELDS
HEIGHTS A SMIDGE HIGHER HEADING INTO SUNDAY NIGHT. THE GFS IS MORE
PROGRESSIVE WITH THE UPPER LOW INTO MONDAY MORNING WHILE THE ECMWF
AND NAM ARE IN BETTER AGREEMENT WITH A SLOWER MOVEMENT....REACHING
SOUTH CENTRAL OKLAHOMA BY 12Z VERSUS THE GFS POSITION OF THE LOW
CROSSING INTO ARKANSAS. HEIGHT DIFFERENCES REMAIN FOR EASTERN
KENTUCKY DOWNSTREAM WITH THE NAM/ECMWF ABOUT 30 DECAMETERS HIGHER
THAN THE GFS SOLUTION. THE BETTER AGREEMENT BETWEEN THE MORE
CONSISTENT ECMWF AND NAM LEND SUPPORT TO FAVORING THE NAM12 ON WX
DETAILS FOR THE SHORT TERM...IN CONJUNCTION WITH THE HRRR EARLY
ON.
SENSIBLE WEATHER WILL FEATURE THE MAJORITY OF ANY PCPN LIFTING
NORTH OF THE AREA BY EVENING WITH JUST A FEW STRAY SHOWERS
POSSIBLE INTO THE NIGHT...MAINLY CONFINED TO THE NORTHERN PARTS OF
THE AREA. GIVEN THE POSITION OF THE PCPN AND THICKER CLOUDS...
EXPECT A SMALL TO MODERATE RIDGE AND VALLEY SPLIT TO DEVELOP FOR
AT LEAST THE SOUTHERN 2/3RDS OF THE CWA. PATCHY VALLEY FOG WILL
ALSO BE POSSIBLE IN PLACES THAT HAVE THE THINNEST CLOUDS. FOR
SUNDAY...OUR WARMEST TEMPERATURES EVER RECORDED FOR DECEMBER
COULD BE THREATENED...DEPENDING ON THE QUALITY OF THE SUNSHINE
SEEN. HIGHS SHOULD EASILY BE IN THE MID 70S WITH UPPER 70S
POSSIBLE. DECEMBER/S RECORD HIGH FOR JKL IS 79 AND LOZ IS 78...
CERTAINLY WITHIN THE REALM OF POSSIBILITIES. ANY CONVECTION IN
THE WARM SECTOR SOUTH OF THE FRONT...LYING NORTH OF THE OHIO
RIVER...COULD END UP AS A THUNDERSTORM PARTICULARLY FOR LOCATIONS
NORTH OF THE MOUNTAIN PARKWAY. FOR SUNDAY AFTERNOON AND EVENING...
THE FRONT WILL START TO SHIFT SOUTH IN RESPONSE TO THE DEVELOPING
SFC LOW TO THE WEST. THIS WILL BRING A THREAT OF CONVECTION AND
HEAVY/TRAINING RAINS BACK INTO AT LEAST THE NORTHERN PARTS OF THE
AREA. THAT NIGHT THE CONVECTION WITH THE FRONT SHOULD WEAKEN AS
THE LOW APPROACHES WITH A STRIATION TO LOW TEMPERATURES DUE TO THE
WAGGLE OF THE BOUNDARY WITH SOME UPPER 40S POSSIBLE NORTH WHILE
THE SOUTH SETTLES INTO THE MID AND UPPER 50S.
FOR TEMPERATURES AND DEWPOINTS...AGAIN STARTED WITH THE SHORTBLEND
GUIDANCE THROUGH SUNDAY MORNING AND THEN THE SUPERBLEND INTO
MONDAY MORNING. MADE MORE SIGNIFICANT CHANGES TO THE LOWS TONIGHT
WITH A BETTER CHANCE FOR A RIDGE AND VALLEY DISTINCTION THROUGH
THE NIGHT FOR MUCH OF THE AREA. AS FOR POPS...ENDED UP CLOSER TO
THE WETTER MET NUMBERS FOR SUNDAY AND SUNDAY NIGHT.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 423 AM EST SAT DEC 26 2015
THE FEATURE OF CONCERN DURING THE EXTENDED PORTION OF THE FORECAST
WILL BE A STRONG WRAPPED UP UPPER LEVEL LOW...LOCATED OVER
NORTHERN MEXICO AND TX AS OF 18Z SUNDAY. WITH A HIGH PRESSURE
RIDGE OVER THE ATLANTIC JUST OFF THE SOUTHEAST CONUS...THIS WILL
ALLOW STRONG SW TO NE FLOW OF MOIST WARM AIR FROM THE GULF OF
MEXICO INTO THE OHIO RIVER VALLEY TO START OF THE
PERIOD...INCREASING AS THE LOW SLIDES EASTWARD TOWARD THE
SOUTHERN MISSISSIPPI RIVER VALLEY BY MONDAY MORNING. FROM
HERE...THE LOW IS EXPECTED TO INCREASE IN STRENGTH AS IT MAKES A
QUICK SHIFT NORTHEASTWARD UP THE MISSISSIPPI RIVER
VALLEY...REACHING FAR WESTERN KY BY 18Z MONDAY...AND THE UPPER
GREAT LAKES BY MONDAY NIGHT. FROM HERE IT WILL CONTINUE TRAVELING
NORTHEASTWARD WHILE LOSING CONSIDERABLE STRENGTH AND EVENTUALLY
FALLING APART. MEANWHILE...A NEW TROUGH WILL BEGIN DIGGING INTO
THE NORTHERN PLAINS TUESDAY NIGHT INTO WEDNESDAY...WITH DECREASING
HEIGHTS EXPECTED ACROSS THE OHIO RIVER VALLEY THROUGH THE REST OF
THE EXTENDED AS THE TROUGH SLOWLY SHIFTS EASTWARD WHILE BECOMING
SOMEWHAT DEAMPLIFIED.
AS FOR SENSIBLE WEATHER...A STRONG SURFACE LOW PRESSURE SYSTEM WILL
ACCOMPANY THE UPPER LEVEL LOW...CONTINUING THE PULL OF
WARM...MOIST...AND UNSTABLE AIR INTO THE OHIO RIVER VALLEY AT THE
SURFACE AS WELL...CORRELATING WELL WITH THE WARM FRONT WHICH WILL
EXTEND ACROSS MUCH OF KY SUNDAY NIGHT INTO MONDAY. THE ASSOCIATED
COLD FRONT WILL QUICKLY PASS THROUGH KENTUCKY AS THE SURFACE LOW AND
UPPER LEVEL LOW MAKE THE QUICK TRANSITION NORTH OF THE OHIO RIVER
VALLEY MONDAY INTO MONDAY NIGHT. THIS WILL CREATE A GOOD SCENARIO
FOR RAIN AND EVEN SOME THUNDER CHANCES MOVING INTO THE REGION LATE
SUNDAY NIGHT...MONDAY...AND INCREASING MONDAY AFTERNOON AND EVENING
ALONG AND JUST AHEAD OF THIS COLD FRONT. GIVEN THE STRENGTH AND
SPEED OF THIS SYSTEM...HIGH WIND GUSTS MAY BE OF A CONCERN AS THE
FRONT PASSES THROUGH. DRIER AIR WILL THEN FILTER IN BEHIND THE
FRONTAL PASSAGE MONDAY NIGHT INTO TUESDAY...WITH POPS SLOWLY
FALLING OFF THROUGH TUESDAY MORNING...AND TUESDAY AFTERNOON IN THE
HIGH TERRAIN.
SEVERAL SHORTWAVES ARE EXPECTED TO MOVE ACROSS THE EASTERN PORTION
OF THE CONUS AS GENERAL UPPER LEVEL TROUGHING TAKES HOLD ONCE MORE
FOR THE REST OF THE EXTENDED PERIOD. LONG RANGE MODELS ARE STILL
FAIRLY UN-AGREED UPON FOR WHEN AND TO WHAT EXTENT THESE SHORTWAVES
WILL AFFECT THE OHIO RIVER VALLEY AND EASTERN KY IN TERMS OF PRECIP.
AS SUCH...STUCK WITH THE MODEL BLEND AT THIS TIME...WHICH PULLS SOME
CHANCES OF RAIN BACK INTO THE REGION DURING THE DAY WEDNESDAY.
ANOTHER WEAKER SYSTEM MAY BRING SOME SLIGHT CHANCES BACK BY FRIDAY.
AS FOR TEMPERATURES...AFTER THE STRONG COLD FRONT MOVES THROUGH AT
THE BEGINNING OF THE PERIOD...AND WITH GENERAL TROUGHING TAKING HOLD
THEREAFTER...EXPECT A SLOW DECLINE IN TEMPERATURES THROUGHOUT THE
EXTENDED. THIS WILL BE AIDED BY GENERAL CLOUDINESS THROUGH A GOOD
PORTION OF THE FORECAST. WHILE SOME UPPER 60S ARE FORECAST ALONG THE
WARM FRONT DURING THE DAY MONDAY...BY THE WEEKEND...WE WILL LIKELY
DROP BELOW 40 DEGREES FOR HIGH TEMPERATURES. THIS WILL ALSO RESULT
IN OVERNIGHT BELOW FREEZING TEMPERATURES FOR THE NEW YEARS WEEKEND
AS WELL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 150 PM EST SAT DEC 26 2015
A DEVELOPING WARM FRONT PUSHING INTO THE AREA IS LIFTING MOST OF
THE CONVECTION NORTH ALONG WITH IT. THIS IS BRUSHING THE LOZ AND
JKL TAF SITES AFTER DEPARTING SME. SYM WILL BE DEALING WITH THIS
AREA FOR THE LONGEST TIME INTO THE EARLY EVENING WHILE SJS MAY
MISS IT ALL TOGETHER AS THE MAIN PCPN STAYS TO THE WEST. WITH THIS
CONVECTION MVFR CIGS WILL BE POSSIBLE...ALONG WITH VIS AS LOW AS
IFR. HOWEVER...THIS ALL SHOULD LIFT FURTHER NORTH WITH TIME AND
SPARE THE AIRPORTS ACROSS EAST KENTUCKY MUCH IN THE WAY OF PCPN
THROUGH THE NIGHT AND INTO THE DAY SUNDAY. ACCORDINGLY...
CONDITIONS WILL BE MAINLY VFR THROUGH THE REST OF THE TAF
CYCLE...THOUGH SOME PATCHY FOG MAY BRING MVFR VIS TO THE SME AND
LOZ SITES IN THE EARLY MORNING HOURS. WINDS FOR THE AREA WILL BE
LIGHT AND VARIABLE THROUGH THE PERIOD...MAINLY FAVORING THE SOUTH
DIRECTION.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
339 PM EST SAT DEC 26 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 552 AM EST SAT DEC 26 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A SRN STREAM TROF OVER THE
ROCKIES WITH SW FLOW DOWNSTREAM INTO THE UPPER GREAT LAKES. TO THE N
IN THE NRN STREAM...A BROADER TROF COVERS MUCH OF CANADA. TIGHTENING
CONFLUENT FLOW BTWN THE 2 BRANCHES IS SETTING UP A STRENGTHENING
UPPER JET IN THE VCNTY OF THE UPPER GREAT LAKES INTO SE CANADA.
MEANWHILE...SHORTWAVE FROM THE SRN STREAM TROF IS EJECTING NE ACROSS
THE WRN PLAINS. COMBINATION OF STRENGTHENING RIGHT ENTRANCE UPPER
JET FORCING AND EJECTING ENERGY HAS LED TO PCPN DEVELOPMENT FROM
NEBRASKA NE INTO ECNTRL MN.
INHERITED FCST IS GENERALLY ON TRACK...BUT SOME REFINEMENTS HAVE
BEEN NEEDED. STRENGTHENING FGEN IN RESPONSE TO STRENGTHENING UPPER
JET AND SHARPENING ISOTACH GRADIENT WILL SUPPORT CONTINUED SPREAD OF
PCPN NE INTO THE UPPER GREAT LAKES TODAY. THE MOST ACTIVE FGEN
RESPONSE/STRENGTHENING IS A BIT HIGHER INTO THE MID LEVELS THAN
TYPICALLY SEEN SO THE HEAVIER BAND OF SNOW WILL BE DISPLACED QUITE A
BIT FARTHER N OF THE SFC/850MB FRONT THAN ONE WOULD NORMALLY SEE.
BIGGEST CONCERN THIS MORNING IS LOW-LEVEL EASTERLY FLOW HOLDING IN
DRIER AIR AT THE LOW LEVELS ACROSS CNTRL AND ERN UPPER MI. MOST OF
THE 00Z HIGH RES MODEL GUIDANCE HAS MAINTAINED ENOUGH DRY AIR TO
SHIFT MAIN AREA OF SNOW A BIT W AND N OF WHAT WAS PREVIOUSLY
EXPECTED. HOURLY RAP/HRRR MODEL RUNS THRU THE NIGHT HAVE CONTINUED
TO MAINTAIN OR EVEN STRENGTHEN THE LOW LEVEL DRY AIR AS HAS THE 06Z
NAM. AS A RESULT...THIS MORNINGS FCST HAS TRENDED POPS/HEAVIEST SNOW
A BIT W AND N...RESULTING IN IRON COUNTY WINTER WX ADVY BEING
DROPPED. MARQUETTE COUNTY COULD SEE QUITE A GRADIENT FROM SE TO NW
TODAY...WITH POTENTIAL FOR AREAS S AND E OF MARQUETTE TO SEE LITTLE
OR NOTHING WHILE SEVERAL INCHES OF SNOW FALL N AND W OF NEGAUNEE.
FARTHER W AND NW...LOOKS LIKE A SOLID ADVY SNOWFALL TODAY OF 3-6
INCHES. BIGGEST CONCERN IS THE KEWEENAW WHERE SOME LAKE ENHANCEMENT
COULD OCCUR UNDER ENE LOW-LEVEL WINDS...POTENTIALLY REQUIRING
UPGRADING OF HEADLINE. WILL NEED TO MONITOR SNOW TRENDS AFTER
SYNOPTIC SNOW ARRIVES TO SEE WHERE OR IF ENHANCEMENT TAKES SHAPE.
LATE THIS AFTN/EVENING...PCPN SHOULD EXPAND ACROSS THE CNTRL AND ERN
FCST AREA AS A PUSH OF STRONGER ISENTROPIC ASCENT/MOISTURE ADVECTION
SHIFTS ACROSS THE AREA. PCPN DURATION SHOULD BE BRIEF ENOUGH TO
PRECLUDE ANY NEED FOR HEADLINES ACROSS THE SCNTRL/E WITH ONLY 1-2
INCHES OF SNOW. CLOSE TO LAKE MI IN MENOMINEE COUNTY...PCPN MAY MIX
WITH RAIN FOR A TIME. BACK TO WRN AND NCNTRL UPPER MI...SYNOPTIC
SNOW WILL WIND DOWN...BUT LAKE/UPSLOPE ENHANCEMENT SHOULD SUPPORT AS
MUCH AS 3-4 INCHES OF ADDITIONAL SNOW IN THE FAVORED HIGH TERRAIN
AREAS AS WINDS BACK FROM NE TO N.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 339 PM EST SAT DEC 26 2015
NAM SHOWS A CLOSED 500 MB LOW OVER CENTRAL TX 00Z MON THAT HEADS
NORTHEAST TO CENTRAL MISSOURI BY 00Z TUE. THIS CLOSED LOW HEADS DUE
NORTH INTO NE WI 12Z TUE AND TO ERN ONTARIO BY 00Z WED. NAM BRINGS
IN SOME 850-500 MB Q-VECTOR CONVERGENCE AND DEEPER MOISTURE INTO THE
AREA MON NIGHT INTO TUE MORNING.
THIS STORM LOOKS TO BE SIGNIFICANT WITH HEAVY SNOW AND THIS WOULD BE
A 5TH PERIOD WATCH IF ONE WAS ISSUED. WILL HOLD OFF FOR NOW AS
TIMING COULD BE A BIT OF AN ISSUE COMING UP FROM THE SOUTHWEST...BUT
QPF WOULD BE 0.50-0.90 INCH WHICH WOULD TRANSLATE TO ABOUT 4.5 TO 9
INCHES OF SNOW FOR THE AREA. WINDS WILL BE FROM THE NORTH NORTHEAST
AND IS COLD ENOUGH FOR SOME LAKE ENHANCEMENT AS WELL. WILL MENTION
THIS IN THE HWO. OTHERWISE...LAKE EFFECT SNOW SHOWERS WILL CONTINUE
THIS PERIOD WITH A DIMINISHING TREND. DID NOT MAKE TOO MANY CHANGES
TO THE GOING TEMPERATURES.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE PLAINS
12Z WED WHICH MOVES INTO THE UPPER GREAT LAKES 12Z THU WITH
TROUGHING REMAINING INTO 12Z SAT WITH COLDER AIR AT 850 MB FLOWING
ACROSS LAKE SUPERIOR. WATER TEMPERATURES ARE AROUND 4C AND 850 MB
TEMPERATURES DROP TO -12C WHICH IS ENOUGH FOR LAKE EFFECT SNOW FOR
00Z FRI. TEMPERATURES LOOK TO BE NEAR NORMAL FOR THIS FORECAST
PERIOD WITH LAKE EFFECT SNOW SHOWERS THE GENERAL RULE NEAR LAKE
SUPERIOR.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1244 PM EST SAT DEC 26 2015
KIWD...BEST SYSTEM SNOW HAS PASSED...BUT WILL SEE WORSENING
CONDITIONS AS LAKE EFFECT PICKS UP TONIGHT INTO SUNDAY.
KCMX...SHOULD SEE CONTINUED LIGHT TO POSSIBLY MODERATE SNOW AS
SYSTEM SNOW IS ENHANCED BY UPSLOPE/LAKE ENHANCEMENT. SOME MODELS
HINTED AT LOWER VIS TO AROUND A HALF MILE...BUT THINK THAT WILL NOT
BE COMMON ENOUGH TO INCLUDE IN THE TAF. WILL SEE SOME IMPROVEMENT AS
SYSTEM SNOW MOVES OUT AND LAKE EFFECT INCREASES TONIGHT INTO SUNDAY.
KSAW...DRY AIR CONTINUES TO WIND OUT SOUTH OF A STRONG SNOW BAND.
EXPECT MOISTURE TO MOVE IN AND ALLOW SNOW AND REDUCED CIG/VIS LATE
THIS AFTERNOON AND EVENING. CONDITIONS WILL STAY POOR INTO SUNDAY AS
LAKE EFFECT STARTS UP.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 552 AM EST SAT DEC 26 2015
E TO NE WINDS WILL INCREASE TODAY UNDER TIGHTENING PRES GRADIENT
BTWN HIGH PRES RIDGE LIFTING N INTO NRN ONTARIO AND LOW PRES TROF
ORGANIZING FROM THE SRN PLAINS TO THE LOWER LAKES. EXPECT WINDS OF
20-30KT OVER WRN LAKE SUPERIOR AND 15-25KT ACROSS THE E. WINDS WILL
DIMINISH A LITTLE TONIGHT BEFORE INCREASING AGAIN ON SUN...THIS TIME
OVER ERN LAKE SUPERIOR WHERE WINDS WILL REACH 20-30KT. HEADING INTO
MON/MON NIGHT...LATEST INDICATIONS ARE FOR A WEAKENING LOW PRES
SYSTEM TO LIFT INTO THE GREAT LAKES WHILE STRONG HIGH PRES RESIDES N
AND NE OF LAKE SUPERIOR. THIS SHOULD RESULT IN A PERIOD OF EASTERLY
GALES DEVELOPING MON/MON EVENING. WINDS WILL THEN DIMINISH TUE AND
BECOME LIGHT...MAINLY UNDER 15KT ON WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 10 AM EST /9 AM CST/ SUNDAY FOR
MIZ001>005-009-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...07
AVIATION...TITUS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1246 PM EST SAT DEC 26 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 552 AM EST SAT DEC 26 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A SRN STREAM TROF OVER THE
ROCKIES WITH SW FLOW DOWNSTREAM INTO THE UPPER GREAT LAKES. TO THE N
IN THE NRN STREAM...A BROADER TROF COVERS MUCH OF CANADA. TIGHTENING
CONFLUENT FLOW BTWN THE 2 BRANCHES IS SETTING UP A STRENGTHENING
UPPER JET IN THE VCNTY OF THE UPPER GREAT LAKES INTO SE CANADA.
MEANWHILE...SHORTWAVE FROM THE SRN STREAM TROF IS EJECTING NE ACROSS
THE WRN PLAINS. COMBINATION OF STRENGTHENING RIGHT ENTRANCE UPPER
JET FORCING AND EJECTING ENERGY HAS LED TO PCPN DEVELOPMENT FROM
NEBRASKA NE INTO ECNTRL MN.
INHERITED FCST IS GENERALLY ON TRACK...BUT SOME REFINEMENTS HAVE
BEEN NEEDED. STRENGTHENING FGEN IN RESPONSE TO STRENGTHENING UPPER
JET AND SHARPENING ISOTACH GRADIENT WILL SUPPORT CONTINUED SPREAD OF
PCPN NE INTO THE UPPER GREAT LAKES TODAY. THE MOST ACTIVE FGEN
RESPONSE/STRENGTHENING IS A BIT HIGHER INTO THE MID LEVELS THAN
TYPICALLY SEEN SO THE HEAVIER BAND OF SNOW WILL BE DISPLACED QUITE A
BIT FARTHER N OF THE SFC/850MB FRONT THAN ONE WOULD NORMALLY SEE.
BIGGEST CONCERN THIS MORNING IS LOW-LEVEL EASTERLY FLOW HOLDING IN
DRIER AIR AT THE LOW LEVELS ACROSS CNTRL AND ERN UPPER MI. MOST OF
THE 00Z HIGH RES MODEL GUIDANCE HAS MAINTAINED ENOUGH DRY AIR TO
SHIFT MAIN AREA OF SNOW A BIT W AND N OF WHAT WAS PREVIOUSLY
EXPECTED. HOURLY RAP/HRRR MODEL RUNS THRU THE NIGHT HAVE CONTINUED
TO MAINTAIN OR EVEN STRENGTHEN THE LOW LEVEL DRY AIR AS HAS THE 06Z
NAM. AS A RESULT...THIS MORNINGS FCST HAS TRENDED POPS/HEAVIEST SNOW
A BIT W AND N...RESULTING IN IRON COUNTY WINTER WX ADVY BEING
DROPPED. MARQUETTE COUNTY COULD SEE QUITE A GRADIENT FROM SE TO NW
TODAY...WITH POTENTIAL FOR AREAS S AND E OF MARQUETTE TO SEE LITTLE
OR NOTHING WHILE SEVERAL INCHES OF SNOW FALL N AND W OF NEGAUNEE.
FARTHER W AND NW...LOOKS LIKE A SOLID ADVY SNOWFALL TODAY OF 3-6
INCHES. BIGGEST CONCERN IS THE KEWEENAW WHERE SOME LAKE ENHANCEMENT
COULD OCCUR UNDER ENE LOW-LEVEL WINDS...POTENTIALLY REQUIRING
UPGRADING OF HEADLINE. WILL NEED TO MONITOR SNOW TRENDS AFTER
SYNOPTIC SNOW ARRIVES TO SEE WHERE OR IF ENHANCEMENT TAKES SHAPE.
LATE THIS AFTN/EVENING...PCPN SHOULD EXPAND ACROSS THE CNTRL AND ERN
FCST AREA AS A PUSH OF STRONGER ISENTROPIC ASCENT/MOISTURE ADVECTION
SHIFTS ACROSS THE AREA. PCPN DURATION SHOULD BE BRIEF ENOUGH TO
PRECLUDE ANY NEED FOR HEADLINES ACROSS THE SCNTRL/E WITH ONLY 1-2
INCHES OF SNOW. CLOSE TO LAKE MI IN MENOMINEE COUNTY...PCPN MAY MIX
WITH RAIN FOR A TIME. BACK TO WRN AND NCNTRL UPPER MI...SYNOPTIC
SNOW WILL WIND DOWN...BUT LAKE/UPSLOPE ENHANCEMENT SHOULD SUPPORT AS
MUCH AS 3-4 INCHES OF ADDITIONAL SNOW IN THE FAVORED HIGH TERRAIN
AREAS AS WINDS BACK FROM NE TO N.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 459 AM EST SAT DEC 26 2015
A SIGNIFICANT LARGE-SCALE PATTERN CHANGE WILL BE UNDERWAY AT THE
START OF THE FORECAST PERIOD AS DEEP TROUGHING DEVELOPS ACROSS THE
CENTRAL CONUS FOR THE UPCOMING WEEK.
SUNDAY...SHORTWAVE TROUGHING OVER THE UPPER MS VALLEY WILL BE
SHIFTING EASTWARD WHILE PHASING WITH A PIECE OF ENEGERY THAT EJECTED
FROM A CLOSED LOW OVER THE SW STATES. WITH SYNOPTIC MOISTURE FROM
TODAYS SYSTEM HAVING ALREADY DEPARTED...PRECIP WILL BE CONFINED TO
LES ALONG LAKE SUPERIOR. WITH INVERSIONS LOWERING TO UNDER 4KFT AND
DEEP DRY AIR ADVECTING ACROSS THE UPPER GREAT LAKES...DO NOT EXPECT
ANY INTENSE LES. RATHER...THE SHALLOW CLOUD MOSTLY LOCATED WITHIN
THE DGZ SUPPORTS PERIODS OF LIGHT TO INFREQUENTLY MODERATE FLUFFY
LES FOR MAINLY THE NW-WIND SNOW BELTS...ESPECIALLY EAST WHERE LOW-
LEVEL CONV IS ENHANCED BY A LINGERING LOW-LEVEL THERMALLY INDUCED
TROUGH OVER LAKE SUPERIOR.
SUNDAY NIGHT THROUGH TUESDAY...MODEL GUIDANCE HAS HAD SOME SERIOUS
STRUGGLES WITH HOW TO HANDLE THE CUTOFF LOW OVER THE SW STATES. 24
HOURS AGO...GUIDANCE WAS TRENDING TOWARD SENDING THE LOW WELL TO THE
SE. NOW...NEARLY THE WHOLE MODEL SUITE HAS SHIFTED WELL TO THE NW.
THE SFC LOW IS NOW PROGGED TO TRACK ACROSS THE UPPER GREAT LAKES
MONDAY NIGHT INTO TUESDAY MORNING.
AS THE SFC LOW APPROACHES...LES ALONG LAKE SUPERIOR WILL SHIFT TO
THE NE WIND BELTS BY DAYBREAK MONDAY...AND THE EAST WIND BELTS BY
MONDAY AFTERNOON. SIGNIFICANT LOW LEVEL DRYING ASSOCIATED WITH A
STRONG 1040 MB HIGH OVER ONTARIO WILL LIKELY LIMIT LES ACTIVITY TO
JUST SOME ISOLATED TO SCATTERED LIGHT SHOWERS.
THE BEST FORCING FROM COUPLED UPPER JET STREAKS AND MID-LEVEL Q-
VECTOR CONV ARE STILL FORECAST TO REMAIN SOUTHEAST OF THE CWA...BUT
A MODEST DEFORMATION BAND ON THE NW SIDE OF THE WILL HAVE THE
POTNETIAL TO BRING SEVERAL INCHES OF ACCUMULATING SNOW ACROSS THE
CWA MONDAY NIGHT INTO EARLY TUESDAY MORNING. THE AFFORMENTED DRY NE
FLOW OFF ONTARIO WILL LIKELY LIMIT SNOWFALL TOTALS...SO DO NOT SEE
ANYTHING MORE THAN AN ADVISORY-LEVEL SNOW AT THIS TIME.
EAST WINDS WILL QUICKLY INCREASE ON MONDAY WITH THE TIGHTENING
PRESSURE GRADIENT BETWEEN THE APPROACHING LOW AND ONTARIO HIGH.
EXPOSED LOCATIONS TO EAST WINDS ALONG THE GREAT LAKES AND HIGH
TERRAIN SHOULD EXPERIENCE FREQUENT GUSTS TO 35 MPH LATE IN THE
AFTERNOON AND WELL INTO MONDAY NIGHT.
WEDNESDAY THROUGH FRIDAY...A PAIR OF MID-LEVEL TROUGHS ARE SET TO
CROSS THE UPPER GREAT LAKES ON WEDNESDAY AND THURSDAY. WITH RATHER
BROAD FORCING AND LIMITED MOISTURE...NEITHER LOOK TO BRING MORE THAN
A COUPLE INCHES OF SNOW. LES FOR THE NW WIND SNOW BELTS THEN
DEVELOPS BEHIND THESE TROUGHS ON FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1244 PM EST SAT DEC 26 2015
KIWD...BEST SYSTEM SNOW HAS PASSED...BUT WILL SEE WORSENING
CONDITIONS AS LAKE EFFECT PICKS UP TONIGHT INTO SUNDAY.
KCMX...SHOULD SEE CONTINUED LIGHT TO POSSIBLY MODERATE SNOW AS
SYSTEM SNOW IS ENHANCED BY UPSLOPE/LAKE ENHANCEMENT. SOME MODELS
HINTED AT LOWER VIS TO AROUND A HALF MILE...BUT THINK THAT WILL NOT
BE COMMON ENOUGH TO INCLUDE IN THE TAF. WILL SEE SOME IMPROVEMENT AS
SYSTEM SNOW MOVES OUT AND LAKE EFFECT INCREASES TONIGHT INTO SUNDAY.
KSAW...DRY AIR CONTINUES TO WIND OUT SOUTH OF A STRONG SNOW BAND.
EXPECT MOISTURE TO MOVE IN AND ALLOW SNOW AND REDUCED CIG/VIS LATE
THIS AFTERNOON AND EVENING. CONDITIONS WILL STAY POOR INTO SUNDAY AS
LAKE EFFECT STARTS UP.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 552 AM EST SAT DEC 26 2015
E TO NE WINDS WILL INCREASE TODAY UNDER TIGHTENING PRES GRADIENT
BTWN HIGH PRES RIDGE LIFTING N INTO NRN ONTARIO AND LOW PRES TROF
ORGANIZING FROM THE SRN PLAINS TO THE LOWER LAKES. EXPECT WINDS OF
20-30KT OVER WRN LAKE SUPERIOR AND 15-25KT ACROSS THE E. WINDS WILL
DIMINISH A LITTLE TONIGHT BEFORE INCREASING AGAIN ON SUN...THIS TIME
OVER ERN LAKE SUPERIOR WHERE WINDS WILL REACH 20-30KT. HEADING INTO
MON/MON NIGHT...LATEST INDICATIONS ARE FOR A WEAKENING LOW PRES
SYSTEM TO LIFT INTO THE GREAT LAKES WHILE STRONG HIGH PRES RESIDES N
AND NE OF LAKE SUPERIOR. THIS SHOULD RESULT IN A PERIOD OF EASTERLY
GALES DEVELOPING MON/MON EVENING. WINDS WILL THEN DIMINISH TUE AND
BECOME LIGHT...MAINLY UNDER 15KT ON WED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 10 AM EST /9 AM CST/ SUNDAY FOR
MIZ001>005-009-084.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KLUBER
AVIATION...TITUS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
449 PM EST SAT DEC 26 2015
.SYNOPSIS...
A WARM FRONT WILL MOVE SLOWLY NORTHWARD THROUGH THE REGION
OVERNIGHT. SUNDAY LOOKS ANOTHER RECORD SETTING WARM DAY BEFORE
COLDER AIR MAKES A RETURN SUNDAY NIGHT INTO MONDAY.
A STORM DURING THE FIRST PART OF THE WORK WEEK COULD START OUT AS
A LIGHT WINTRY MIX OVER NORTHERN AREAS BEFORE CHANGING TO BACK TO
JUST RAIN BEFORE ENDING. TEMPERATURES WILL COOL OFF TO NEAR NORMAL
THROUGH THE REST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THE RADAR CONTINUES TO SHOW A DISORGANIZED AREA OF MAINLY LIGHT
RAIN FROM THE CENTRAL MOUNTAINS NORTH AND EAST. THE HRRR SHOWS
THIS DISORGANIZED ACTIVITY MORE OR LESS CONTINUING THROUGHOUT THE
DAY...STILL FAVORING THESE NORTHERN AREAS...BEFORE A STEADIER AND
MORE WIDESPREAD SHIELD OF RAIN SPREADS INTO THE REGION AFTER DARK.
THE WARM FRONT TO OUR SOUTH WILL PROGRESS NORTHWARD OVERNIGHT.
ON FIRST GLANCE THE SURFACE PRESSURE TROUGH LOOKS LIKE IT SHOULD
PASS TO OUR NORTH BY MIDNIGHT OR SO...BUT A CLOSER LOOKS SHOWS A
FAIRLY SUBSTANTIAL COLD AIR DAMMING SIGNATURE THAT WILL SLOW THE
WARMUP. THE NAM/GFS BOTH SHOW A VIGOROUS NORTHEASTERLY COMPONENT
TO THE LOW LEVEL AGEOSTROPHIC FLOW AND THE SURFACE BASED LIFTED
INDICES SHOW THE CLASSIC STABLE WEDGE HOLDING THROUGH 12Z BEFORE
MIXING OUT JUST AHEAD OF THE FRONT AS IT RE-ENTERS THE REGION AS
A COLD FRONT FROM THE WEST.
I DID KEEP THE MENTION OF A SMALL CHANCE OF A RUMBLE OF THUNDER
OVER NWRN AREAS LATER TONIGHT AS THAT`S WHERE THE STABILITY ERODES
MOST SIGNIFICANTLY. LI`S ARE FORECAST TO APPROACH ZERO AND MID
LEVEL LAPSE RATES EXCEED 6C/KM.
THE SLOW PROGRESS OF THE WARM AIR ARGUES FOR NEAR STEADY/SLOWLY
RISING TEMPS FOR THE LATTER HALF OF THE NIGHT. OVERALL STILL MUCH
MILDER THAN NORMAL FOR LATE DECEMBER.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
THE COLD FRONT WILL BE ENTERING MY WESTERN ZONES EARLY IN THE
DAY...BUT PROBABLY WILL NOT BE FAST ENOUGH TO PREVENT HIGH TEMPS
FROM SOARING INTO THE 60S OR EVEN LOWER 70S OVER MUCH OF THE
SOUTHERN 2/3 OR SO OF THE REGION. SHORT RANGE GUIDANCE AGREES THAT
THE FRONT WILL CLEAR MY SERN ZONES BY NIGHTFALL BEFORE BECOMING
STATIONARY YET AGAIN JUST SOUTH OF THE STATE.
THE BEST CHANCE FOR RAIN WILL BE OVER THE NORTHERN 1/2 OF THE CWA
AS THE FRONT SAGS SOUTH...WITH SHOWERS BEING MORE SPOTTY OVER
SOUTHERN LOCATIONS.
RECORD HIGHS FOR THE 27TH...
52F AT IPT AND 59F AT MDT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
VERY MOIST STREAM OF AIR WILL BE AIMED AT PA...VIA SOUTHWESTERLY
FLOW...THROUGH MUCH OF THE LONG TERM PERIOD. UPPER RIDGE ALONG
THE EAST COAST WILL BE PUSHED EAST BY NRN STREAM SHORTWAVE
ENERGY...AND THE SLOW EASTWARD PROGRESSION OF LARGER SCALE TROF
NOW OVER THE SWRN U.S...AIDED ALSO BY SHORTWAVE WITHIN.
MON-DAY WILL BE QUITE CHILLY - BUT VERY NEARLY NORMAL - AS TEMPS
GO LITTLE UPWARD THROUGH THE DAY. NORTH WINDS WILL BRING IN SOME
DECENTLY COLD AIR FROM A LARGE HIGH PRESSURE AREA MOVING ACROSS
CANADA AND INTO NEW ENGLAND. THE COLD AIR IS THE MOST INTERESTING
CHALLENGE IN THIS FORECAST...AND MAYBE FOR THE NEXT WEEK-PLUS. HOW
DEEP THE COLD AIR CAN GET AND HOW PERSISTENT IT WILL BE AGAINST
THE WARM AIR ADVECTION FROM A VERY STRONG LOW PRESSURE AREA MOVING
UP FROM THE LOWER MS VALLEY. SE WINDS OF 40KTS AT 8H MONDAY WILL
INCREASE TO 60KTS AS THEY VEER TO COME FROM DUE SOUTH. THE
MOISTURE TRANSPORT RESULTS IN PWATS OF 3 STANDARD DEVIATIONS ABOVE
NORMAL...WHICH IS NOT MUCH COMPARED TO SUNDAY/S LOFTY VALUES.
HOWEVER...THE MOISTURE ROLLING OVERHEAD WILL LIKELY BE LIQUID
FALLING INTO THE SUB- FREEZING AIR IN THE LOWEST 2-4KFT.
THE TROUBLE WOULD BE RE-FROZEN/FREEZING PRECIP LATE IN THE DAY ON
MONDAY AND MONDAY NIGHT. THE COLDEST/DEEPEST COLD AIR WILL BE IN
THE NERN MTNS AND MAY GET TRAPPED IN CENTRAL PA. HOWEVER...THE
TEMP GUIDANCE AT THIS POINT IS SOLID WITH CONTINUITY AND KEEPS THE
SRN HALF OF THE AREA ABOVE FREEZING THROUGH THE PERIOD. THE RECORD
WARMTH OF RECENT TIMES AND WARM/WET GROUND WILL BE NEGATIVES TO
FREEZING RAIN. SREF MEMBER P-TYPES PAINT A HIGH LIKELIHOOD OF
SLEET VS. FZRA. IN THE PAST...FORECASTS OF IP HAVE BEEN OVERDONE
BY THE SREFS AND A GREAT UNCERTAINTY REMAINS AS TO WHAT THE P-TYPE
WILL BE AND HOW LONG IT COULD STAY SOMETHING OTHER THAN PLAIN
RAIN. WILL KEEP IT CLOSE TO THE GOING FCST...BUT MENTION LESS
FZRA. BY TUESDAY MORNING....THE TEMP PROFILES ARE ENTIRELY RAIN
SAVE FOR PERHAPS TIOGA CO. THE PRECIP DOES PASS THROUGH IN
12-15HRS. THE STORM DEVELOPS A SECONDARY LOW OVER MD/DE AND SHOULD
CUT THINGS OFF TUESDAY MORNING. HELD SOME CHC POPS THRU THE AFTN
TO ACCOUNT FOR TIMING UNCERTAINTY.
ANOTHER UPPER SHORT WAVE IS IN STORE FOR EARLY THU AND BRINGS
RAIN...THEN COLDER AIR FOR THE LATER PART OF THE WEEK. TEMPS
FINALLY GET COLD ENOUGH AND FLOW OUT OF THE W/NW TO GENERATE LOTS
OF LAKE EFFECT SNOW. LAKES TEMPS HAVE GOT TO BE MUCH ABOVE
NORMAL...WHICH SHOULD HELP GENERATE PLENTY OF INSTABILITY AND
MOISTURE FLUX. 8H TEMPS DROP INTO THE NEGATIVE DOUBLE-DIGITS FRI-
MON UNDER A VERY DEEP UPPER TROUGH.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
AS EXPECTED...NOT A LOT OF RAIN OR FOG SO FAR. ONLY A FEW
SPRINKLES. WHILE CIGS ARE LOW...FOG AND HZ NOT WIDESPREAD.
A FAST MOVING BAND OF RAIN TO THE SW WILL QUICKLY LIFT NE
ACROSS THE REGION THIS EVENING.
MINOR ADJUSTMENTS MADE TO 21Z TAFS.
EARLIER DISCUSSION BELOW.
CONDITIONS WILL DETERIORATE FROM SW TO NE AS A SLOWLY ADVANCING
WARM FRONT APPROACHES FROM THE SOUTH. EASTERN TERMINALS WILL
REMAIN VFR INTO THE LATE AFTERNOON BEFORE CONDITIONS DROP THERE
AS WELL.
EXPECT WIDESPREAD IFR/MVFR OVERNIGHT ALONG WITH AREAS OF RAIN.
THERE COULD BE A THUNDERSTORM OVER NWRN AREAS AHEAD OF A COLD
FRONT THAT WILL ENTER THE AREA SUNDAY MORNING.
OUTLOOK...
SUN...IFR/MVFR WITH PERIODS OF RAIN. IMPROVING CONDITIONS...ESPECIALLY
OVER SOUTHERN TERMINALS.
MON...VFR EARLY WITH AREAS MVFR AND RAIN DEVELOPING FROM WEST TO
EAST IN THE AFTERNOON.
MON NIGHT...DETERIORATING CONDITIONS. RAIN DEVELOPING /POSSIBLY A
WINTRY MIX NORTH/.
TUE...RAIN SHOWERS TAPERING OFF. GENERALLY MVFR WITH SLOWLY
IMPROVING CONDITIONS.
WED-THU...MVFR LIKELY NW. VFR SE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...DANGELO/GARTNER
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
353 PM EST SAT DEC 26 2015
.SYNOPSIS...
A WARM FRONT WILL MOVE SLOWLY NORTHWARD THROUGH THE REGION
OVERNIGHT. SUNDAY LOOKS ANOTHER RECORD SETTING WARM DAY BEFORE
COLDER AIR MAKES A RETURN SUNDAY NIGHT INTO MONDAY.
A STORM DURING THE FIRST PART OF THE WORK WEEK COULD START OUT AS
A LIGHT WINTRY MIX OVER NORTHERN AREAS BEFORE CHANGING TO BACK TO
JUST RAIN BEFORE ENDING. TEMPERATURES WILL COOL OFF TO NEAR NORMAL
THROUGH THE REST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THE RADAR CONTINUES TO SHOW A DISORGANIZED AREA OF MAINLY LIGHT
RAIN FROM THE CENTRAL MOUNTAINS NORTH AND EAST. THE HRRR SHOWS
THIS DISORGANIZED ACTIVITY MORE OR LESS CONTINUING THROUGHOUT THE
DAY...STILL FAVORING THESE NORTHERN AREAS...BEFORE A STEADIER AND
MORE WIDESPREAD SHIELD OF RAIN SPREADS INTO THE REGION AFTER DARK.
THE WARM FRONT TO OUR SOUTH WILL PROGRESS NORTHWARD OVERNIGHT. ON
FIRST GLANCE THE SURFACE PRESSURE TROUGH LOOKS LIKE IT SHOULD
PASS TO OUR NORTH BY MIDNIGHT OR SO...BUT A CLOSER LOOKS SHOWS A
FAIRLY SUBSTANTIAL COLD AIR DAMMING SIGNATURE THAT WILL SLOW THE
WARMUP. THE NAM/GFS BOTH SHOW A VIGOROUS NORTHEASTERLY COMPONENT
TO THE LOW LEVEL AGEOSTROPHIC FLOW AND THE SURFACE BASED LIFTED
INDICES SHOW THE CLASSIC STABLE WEDGE HOLDING THROUGH 12Z BEFORE
MIXING OUT JUST AHEAD OF THE FRONT AS IT RE-ENTERS THE REGION AS A
COLD FRONT FROM THE WEST.
I DID KEEP THE MENTION OF A SMALL CHANCE OF A RUMBLE OF THUNDER
OVER NWRN AREAS LATER TONIGHT AS THAT`S WHERE THE STABILITY ERODES
MOST SIGNIFICANTLY. LI`S ARE FORECAST TO APPROACH ZERO AND MID
LEVEL LAPSE RATES EXCEED 6C/KM.
THE SLOW PROGRESS OF THE WARM AIR ARGUES FOR NEAR STEADY/SLOWLY
RISING TEMPS FOR THE LATTER HALF OF THE NIGHT. OVERALL STILL MUCH
MILDER THAN NORMAL FOR LATE DECEMBER.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
THE COLD FRONT WILL BE ENTERING MY WESTERN ZONES EARLY IN THE
DAY...BUT PROBABLY WILL NOT BE FAST ENOUGH TO PREVENT HIGH TEMPS
FROM SOARING INTO THE 60S OR EVEN LOWER 70S OVER MUCH OF THE
SOUTHERN 2/3 OR SO OF THE REGION. SHORT RANGE GUIDANCE AGREES THAT
THE FRONT WILL CLEAR MY SERN ZONES BY NIGHTFALL BEFORE BECOMING
STATIONARY YET AGAIN JUST SOUTH OF THE STATE.
THE BEST CHANCE FOR RAIN WILL BE OVER THE NORTHERN 1/2 OF THE CWA
AS THE FRONT SAGS SOUTH...WITH SHOWERS BEING MORE SPOTTY OVER
SOUTHERN LOCATIONS.
RECORD HIGHS FOR THE 27TH...
52F AT IPT AND 59F AT MDT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
VERY MOIST STREAM OF AIR WILL BE AIMED AT PA...VIA SOUTHWESTERLY
FLOW...THROUGH MUCH OF THE LONG TERM PERIOD. UPPER RIDGE ALONG
THE EAST COAST WILL BE PUSHED EAST BY NRN STREAM SHORTWAVE
ENERGY...AND THE SLOW EASTWARD PROGRESSION OF LARGER SCALE TROF
NOW OVER THE SWRN U.S...AIDED ALSO BY SHORTWAVE WITHIN.
MON-DAY WILL BE QUITE CHILLY - BUT VERY NEARLY NORMAL - AS TEMPS
GO LITTLE UPWARD THROUGH THE DAY. NORTH WINDS WILL BRING IN SOME
DECENTLY COLD AIR FROM A LARGE HIGH PRESSURE AREA MOVING ACROSS
CANADA AND INTO NEW ENGLAND. THE COLD AIR IS THE MOST INTERESTING
CHALLENGE IN THIS FORECAST...AND MAYBE FOR THE NEXT WEEK-PLUS. HOW
DEEP THE COLD AIR CAN GET AND HOW PERSISTENT IT WILL BE AGAINST
THE WARM AIR ADVECTION FROM A VERY STRONG LOW PRESSURE AREA MOVING
UP FROM THE LOWER MS VALLEY. SE WINDS OF 40KTS AT 8H MONDAY WILL
INCREASE TO 60KTS AS THEY VEER TO COME FROM DUE SOUTH. THE
MOISTURE TRANSPORT RESULTS IN PWATS OF 3 STANDARD DEVIATIONS ABOVE
NORMAL...WHICH IS NOT MUCH COMPARED TO SUNDAY/S LOFTY VALUES.
HOWEVER...THE MOISTURE ROLLING OVERHEAD WILL LIKELY BE LIQUID
FALLING INTO THE SUB- FREEZING AIR IN THE LOWEST 2-4KFT.
THE TROUBLE WOULD BE RE-FROZEN/FREEZING PRECIP LATE IN THE DAY ON
MONDAY AND MONDAY NIGHT. THE COLDEST/DEEPEST COLD AIR WILL BE IN
THE NERN MTNS AND MAY GET TRAPPED IN CENTRAL PA. HOWEVER...THE
TEMP GUIDANCE AT THIS POINT IS SOLID WITH CONTINUITY AND KEEPS THE
SRN HALF OF THE AREA ABOVE FREEZING THROUGH THE PERIOD. THE RECORD
WARMTH OF RECENT TIMES AND WARM/WET GROUND WILL BE NEGATIVES TO
FREEZING RAIN. SREF MEMBER P-TYPES PAINT A HIGH LIKELIHOOD OF
SLEET VS. FZRA. IN THE PAST...FORECASTS OF IP HAVE BEEN OVERDONE
BY THE SREFS AND A GREAT UNCERTAINTY REMAINS AS TO WHAT THE P-TYPE
WILL BE AND HOW LONG IT COULD STAY SOMETHING OTHER THAN PLAIN
RAIN. WILL KEEP IT CLOSE TO THE GOING FCST...BUT MENTION LESS
FZRA. BY TUESDAY MORNING....THE TEMP PROFILES ARE ENTIRELY RAIN
SAVE FOR PERHAPS TIOGA CO. THE PRECIP DOES PASS THROUGH IN
12-15HRS. THE STORM DEVELOPS A SECONDARY LOW OVER MD/DE AND SHOULD
CUT THINGS OFF TUESDAY MORNING. HELD SOME CHC POPS THRU THE AFTN
TO ACCOUNT FOR TIMING UNCERTAINTY.
ANOTHER UPPER SHORT WAVE IS IN STORE FOR EARLY THU AND BRINGS
RAIN...THEN COLDER AIR FOR THE LATER PART OF THE WEEK. TEMPS
FINALLY GET COLD ENOUGH AND FLOW OUT OF THE W/NW TO GENERATE LOTS
OF LAKE EFFECT SNOW. LAKES TEMPS HAVE GOT TO BE MUCH ABOVE
NORMAL...WHICH SHOULD HELP GENERATE PLENTY OF INSTABILITY AND
MOISTURE FLUX. 8H TEMPS DROP INTO THE NEGATIVE DOUBLE-DIGITS FRI-
MON UNDER A VERY DEEP UPPER TROUGH.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
CONDITIONS WILL DETERIORATE FROM SW TO NE AS A SLOWLY ADVANCING
WARM FRONT APPROACHES FROM THE SOUTH. EASTERN TERMINALS WILL
REMAIN VFR INTO THE LATE AFTERNOON BEFORE CONDITIONS DROP THERE
AS WELL.
EXPECT WIDESPREAD IFR/MVFR OVERNIGHT ALONG WITH AREAS OF RAIN.
THERE COULD BE A THUNDERSTORM OVER NWRN AREAS AHEAD OF A COLD
FRONT THAT WILL ENTER THE AREA SUNDAY MORNING.
OUTLOOK...
SUN...IFR/MVFR WITH PERIODS OF RAIN. IMPROVING CONDITIONS...ESPECIALLY
OVER SOUTHERN TERMINALS.
MON...VFR EARLY WITH AREAS MVFR AND RAIN DEVELOPING FROM WEST TO
EAST IN THE AFTERNOON.
MON NIGHT...DETERIORATING CONDITIONS. RAIN DEVELOPING /POSSIBLY A
WINTRY MIX NORTH/.
TUE...RAIN SHOWERS TAPERING OFF. GENERALLY MVFR WITH SLOWLY
IMPROVING CONDITIONS.
WED-THU...MVFR LIKELY NW. VFR SE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...DANGELO/GARTNER
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
239 PM EST SAT DEC 26 2015
.SYNOPSIS...
A WARM FRONT WILL MOVE SLOWLY NORTHWARD THROUGH THE REGION
OVERNIGHT. SUNDAY LOOKS ANOTHER RECORD SETTING WARM DAY BEFORE
COLDER AIR MAKES A RETURN SUNDAY NIGHT INTO MONDAY.
A STORM DURING THE FIRST PART OF THE WORK WEEK COULD START OUT AS
A LIGHT WINTRY MIX OVER NORTHERN AREAS BEFORE CHANGING TO BACK TO
JUST RAIN BEFORE ENDING. TEMPERATURES WILL COOL OFF TO NEAR NORMAL
THROUGH THE REST OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE RADAR CONTINUES TO SHOW A DISORGANIZED AREA OF MAINLY LIGHT
RAIN FROM THE CENTRAL MOUNTAINS NORTH AND EAST. THE HRRR SHOWS
THIS DISORGANIZED ACTIVITY MORE OR LESS CONTINUING THROUGHOUT THE
DAY...STILL FAVORING THESE NORTHERN AREAS...BEFORE A STEADIER AND
MORE WIDESPREAD SHIELD OF RAIN SPREADS INTO THE REGION AFTER DARK.
THE WARM FRONT TO OUR SOUTH WILL PROGRESS NORTHWARD OVERNIGHT. ON
FIRST GLANCE THE SURFACE PRESSURE TROUGH LOOKS LIKE IT SHOULD
PASS TO OUR NORTH BY MIDNIGHT OR SO...BUT A CLOSER LOOKS SHOWS A
FAIRLY SUBSTANTIAL COLD AIR DAMMING SIGNATURE THAT WILL SLOW THE
WARMUP. THE NAM/GFS BOTH SHOW A VIGOROUS NORTHEASTERLY COMPONENT
TO THE LOW LEVEL AGEOSTROPHIC FLOW AND THE SURFACE BASED LIFTED
INDICES SHOW THE CLASSIC STABLE WEDGE HOLDING THROUGH 12Z BEFORE
MIXING OUT JUST AHEAD OF THE FRONT AS IT RE-ENTERS THE REGION AS A
COLD FRONT FROM THE WEST.
I DID KEEP THE MENTION OF A SMALL CHANCE OF A RUMBLE OF THUNDER
OVER NWRN AREAS LATER TONIGHT AS THAT`S WHERE THE STABILITY ERODES
MOST SIGNIFICANTLY. LI`S ARE FORECAST TO APPROACH ZERO AND MID
LEVEL LAPSE RATES EXCEED 6C/KM.
THE SLOW PROGRESS OF THE WARM AIR ARGUES FOR NEAR STEADY/SLOWLY
RISING TEMPS FOR THE LATTER HALF OF THE NIGHT. OVERALL STILL MUCH
MILDER THAN NORMAL FOR LATE DECEMBER.
&&
.SHORT TERM /SUNDAY/...
THE COLD FRONT WILL BE ENTERING MY WESTERN ZONES EARLY IN THE
DAY...BUT PROBABLY WILL NOT BE FAST ENOUGH TO PREVENT HIGH TEMPS
FROM SOARING INTO THE 60S OR EVEN LOWER 70S OVER MUCH OF THE
SOUTHERN 2/3 OR SO OF THE REGION. SHORT RANGE GUIDANCE AGREES THAT
THE FRONT WILL CLEAR MY SERN ZONES BY NIGHTFALL BEFORE BECOMING
STATIONARY YET AGAIN JUST SOUTH OF THE STATE.
THE BEST CHANCE FOR RAIN WILL BE OVER THE NORTHERN 1/2 OF THE CWA
AS THE FRONT SAGS SOUTH...WITH SHOWERS BEING MORE SPOTTY OVER
SOUTHERN LOCATIONS.
RECORD HIGHS FOR THE 27TH...
52F AT IPT AND 59F AT MDT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
MON-DAY WILL BE QUITE CHILLY - BUT VERY NEARLY NORMAL - AS TEMPS
GO LITTLE UPWARD THROUGH THE DAY. NORTH WINDS WILL BRING IN SOME
DECENTLY COLD AIR FROM A LARGE HIGH PRESSURE AREA MOVING ACROSS
CANADA AND INTO NEW ENGLAND. THE COLD AIR IS THE MOST INTERESTING
CHALLENGE IN THIS FORECAST...AND MAYBE FOR THE NEXT WEEK-PLUS. HOW
DEEP THE COLD AIR CAN GET AND HOW PERSISTENT IT WILL BE AGAINST
THE WARM AIR ADVECTION FROM A VERY STRONG LOW PRESSURE AREA MOVING
UP FROM THE LOWER MS VALLEY. SE WINDS OF 40KTS AT 8H MONDAY WILL
INCREASE TO 60KTS AS THEY VEER TO COME FROM DUE SOUTH. THE
MOISTURE TRANSPORT RESULTS IN PWATS OF 3 STANDARD DEVIATIONS ABOVE
NORMAL...WHICH IS NOT MUCH COMPARED TO SUNDAY/S LOFTY VALUES.
HOWEVER...THE MOISTURE ROLLING OVERHEAD WILL LIKELY BE LIQUID
FALLING INTO THE SUB- FREEZING AIR IN THE LOWEST 2-4KFT.
THE TROUBLE WOULD BE RE-FROZEN/FREEZING PRECIP LATE IN THE DAY ON
MONDAY AND MONDAY NIGHT. THE COLDEST/DEEPEST COLD AIR WILL BE IN
THE NERN MTNS AND MAY GET TRAPPED IN CENTRAL PA. HOWEVER...THE
TEMP GUIDANCE AT THIS POINT IS SOLID WITH CONTINUITY AND KEEPS THE
SRN HALF OF THE AREA ABOVE FREEZING THROUGH THE PERIOD. THE RECORD
WARMTH OF RECENT TIMES AND WARM/WET GROUND WILL BE NEGATIVES TO
FREEZING RAIN. SREF MEMBER P-TYPES PAINT A HIGH LIKELIHOOD OF
SLEET VS. FZRA. IN THE PAST...FORECASTS OF IP HAVE BEEN OVERDONE
BY THE SREFS AND A GREAT UNCERTAINTY REMAINS AS TO WHAT THE P-TYPE
WILL BE AND HOW LONG IT COULD STAY SOMETHING OTHER THAN PLAIN
RAIN. WILL KEEP IT CLOSE TO THE GOING FCST...BUT MENTION LESS
FZRA. BY TUESDAY MORNING....THE TEMP PROFILES ARE ENTIRELY RAIN
SAVE FOR PERHAPS TIOGA CO. THE PRECIP DOES PASS THROUGH IN
12-15HRS. THE STORM DEVELOPS A SECONDARY LOW OVER MD/DE AND SHOULD
CUT THINGS OFF TUESDAY MORNING. HELD SOME CHC POPS THRU THE AFTN
TO ACCOUNT FOR TIMING UNCERTAINTY.
ANOTHER UPPER SHORT WAVE IS IN STORE FOR EARLY THU AND BRINGS
RAIN...THEN COLDER AIR FOR THE LATER PART OF THE WEEK. TEMPS
FINALLY GET COLD ENOUGH AND FLOW OUT OF THE W/NW TO GENERATE LOTS
OF LAKE EFFECT SNOW. LAKES TEMPS HAVE GOT TO BE MUCH ABOVE
NORMAL...WHICH SHOULD HELP GENERATE PLENTY OF INSTABILITY AND
MOISTURE FLUX. 8H TEMPS DROP INTO THE NEGATIVE DOUBLE-DIGITS FRI-
MON UNDER A VERY DEEP UPPER TROUGH.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CONDITIONS WILL DETERIORATE FROM SW TO NE AS A SLOWLY ADVANCING
WARM FRONT APPROACHES FROM THE SOUTH. EASTERN TERMINALS WILL
REMAIN VFR INTO THE LATE AFTERNOON BEFORE CONDITIONS DROP THERE
AS WELL.
EXPECT WIDESPREAD IFR/MVFR OVERNIGHT ALONG WITH AREAS OF RAIN.
THERE COULD BE A THUNDERSTORM OVER NWRN AREAS AHEAD OF A COLD
FRONT THAT WILL ENTER THE AREA SUNDAY MORNING.
OUTLOOK...
SUN...IFR/MVFR WITH PERIODS OF RAIN. IMPROVING CONDITIONS...ESPECIALLY
OVER SOUTHERN TERMINALS.
MON...VFR EARLY WITH AREAS MVFR AND RAIN DEVELOPING FROM WEST TO
EAST IN THE AFTERNOON.
MON NIGHT...DETERIORATING CONDITIONS. RAIN DEVELOPING /POSSIBLY A
WINTRY MIX NORTH/.
TUE...RAIN SHOWERS TAPERING OFF. GENERALLY MVFR WITH SLOWLY
IMPROVING CONDITIONS.
WED-THU...MVFR LIKELY NW. VFR SE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...DANGELO/MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS SEATTLE WA
902 AM PST SAT DEC 26 2015
.SYNOPSIS...AN UPPER LEVEL RIDGE CROSSING WESTERN WASHINGTON SHOULD
PRODUCE MOSTLY CLOUDY AND MAINLY DRY WEATHER TODAY. A WEAKENING
FRONTAL SYSTEM WILL SPREAD RAIN INLAND LATER TONIGHT AND SUNDAY
MORNING. TEMPERATURES WILL BE COLD ENOUGH FOR A RAIN SNOW MIX IN
PLACES. A WEAK UPPER LEVEL TROUGH WILL FOLLOW WITH SCATTERED SHOWERS
SUNDAY AFTERNOON. SHOWERS WILL DIMINISH ON MONDAY. ANOTHER WEAK
SYSTEM MAY BRING A LITTLE RAIN TO THE AREA TUESDAY AFTERNOON THROUGH
WEDNESDAY. A STRONG UPPER LEVEL RIDGE SHOULD BRING DRY WEATHER LATE
THIS WEEK.
&&
.SHORT TERM...A PROGRESSIVE UPPER RIDGE EXTENDS FROM NORTHERN
BRITISH COLUMBIA INTO THE OFFSHORE WATERS OF CENTRAL CALIFORNIA THIS
MORNING. THERE IS ENOUGH FLOW THROUGH THE RIDGE FOR MOISTURE TO
STREAM THROUGH...AND ABUNDANT CLOUD COVER IS SEEN OVER THE AREA THIS
MORNING. LITTLE IN THE WAY OF FOG IS BEING SEEN.
KLGX RADAR SHOWS AN AREA OF LIGHT RAIN EXTENDING FROM CENTRAL
VANCOUVER ISLAND SOUTHWARD THROUGH THE FAR OUTER COASTAL ZONES THIS
MORNING AND A NARROW BAND OF VERY LIGHT RAIN EXTENDS FROM ABOUT KUIL
SOUTHWESTWARD. THE INCOMING 12Z NAM...12Z GFS20...AND HRRR SHOW THIS
VERY LIGHT PRECIPITATION REMAINING FROM AROUND THE NORTH COASTAL
ZONE OFFSHORE THROUGH EARLY THIS EVENING.
WILL UPDATE THE FORECAST FOR TODAY TO REMOVE FOG FROM ALL AREAS
EXCEPT THE CHEHALIS GAP FROM ABOUT SHELTON AND BRINNON TO HOQUIAM
AND TO REMOVE PRECIPITATION FROM THE INTERIOR ZONES THIS AFTERNOON.
RIDGING OVER THE PACNW AND COLD AIR ALOFT FROM ABOUT 40N NORTHWARD
AT 145W PROMISES TO TAKE THE INCOMING TROUGH AND SPLIT IT TAKING THE
BRUNT OF IT DOWN INTO OREGON AND CALIFORNIA. THE NEGATIVE TILT OF
THE INCOMING SPLITTING SYSTEM WILL RESULT IN LOW LEVEL PRES
GRADIENTS REMAINING RATHER NELY. THIS MEANS THAT COOL AIR FLOWING
OUT FROM THE FRASER RIVER VALLEY IN WESTERN WHATCOM COUNTY MAY ALLOW
PRECIPITATION TO START BRIEFLY AS SNOW OR A RAIN SNOW MIX AROUND THE
BELLINGHAM AREA...AND COLD AIR DAMMING AROUND THE HOOD CANAL WHERE
1000-850 MB THICKNESSES AROUND 1299M ARE EXPECTED SUNDAY MORNING
WITH ABOUT 0.3 INCHES OF PRECIPITATION...MAY RESULT IN SOME SNOW OR
A RAIN SNOW MIX AROUND SHELTON AND BRINNON SUNDAY MORNING.
PRECIPITATION WILL SPREAD INTO WESTERN WASHINGTON SUNDAY MORNING AS
A COLD RAIN WITH LOW LEVEL THICKNESSES AROUND 1304M. THE FRONT WILL
MOVE INTO THE CASCADES SUNDAY EVENING TURNING PRECIPITATION TO
SCATTERED SHOWERS...THEN SHOWERS WILL BECOME ISOLATED ON MONDAY WITH
A WEAK TROUGH PUSHING INLAND.
MONDAY NIGHT WILL BE MAINLY DRY AS A WEAK AND DIRTY UPPER RIDGE
MOVES ACROSS THE AREA.
OTHER THAN CHANGES TO THE FIRST PERIOD MENTIONED ABOVE...CURRENT
FORECASTS LOOK GOOD. ALBRECHT
.LONG TERM...FROM THE PREVIOUS LONG TERM DISCUSSION...THE GFS AND
ECMWF HAVE A SMALL WEAK UPPER LEVEL LOW MOVING SE ALONG THE B.C.
COAST ON TUESDAY WITH A LITTLE LIGHT PRECIP OUT AHEAD OF IT. THE
ECMWF IS A LITTLE FASTER WITH THE LOW...BUT AT LEAST THE MODELS HAVE
THE SAME GENERAL IDEA.
A MODERATELY HIGH AMPLITUDE UPPER LEVEL RIDGE FORMS OFFSHORE BEHIND
THE LOW...THEN MOVES OVER THE COAST BY WEDNESDAY AFTERNOON TO START
A DRY PERIOD. OVERALL THE MODELS HAVE THE RIDGE DOMINATING THROUGH
NEXT WEEKEND...BUT THERE APPEAR TO BE A COUPLE OF CLOSE CALLS WITH
VERY WEAK SYSTEMS. WITH LESS CLOUD COVER UNDER THE RIDGE IT LOOKS
LIKE A GOOD FOG PRODUCER. THERE WILL BE OFFSHORE FLOW BUT PROBABLY
NOT ENOUGH WIND TO COMPLETELY SCOUR OUT THE MORNING FOG IN SOME
AREAS. KAM
&&
.AVIATION...WESTERLY FLOW ALOFT TODAY WILL TURN SOUTHWESTERLY
TONIGHT AS A FRONT APPROACHES THE REGION. SOUTHEAST SURFACE WINDS
WILL INCREASE THIS AFTERNOON AND TONIGHT. AIR MASS IS MOIST AND
STABLE.
CLOUDS FROM THE APPROACHING SYSTEM HAVE BROUGHT CEILINGS INTO
WESTERN WASHINGTON...MAINLY AROUND 5K FT...WITH MORE CLOUD LAYERS
ABOVE THAT. THERE IS PATCHY IFR STRATUS AS WELL. THE STRATUS WILL
EVAPORATE BUT SOME LOWERING OF CEILINGS OVERALL WILL OCCUR TODAY...
AND MVFR CEILINGS WILL DEVELOP TONIGHT AS RAIN SLOWLY SPREADS
INLAND.
KSEA...DISCUSSION ABOVE APPLIES WITH VFR EXPECTED MOST OF TODAY AND
MVFR TONIGHT. RAIN LIKELY TO BEGIN AROUND 15Z SUNDAY AND CONTINUE
THROUGH THE DAY. SE WIND 4-8 KT THIS MORNING WILL INCREASE TO 8-12
KT THIS EVENING. CHB
&&
.MARINE...AN APPROACHING FRONT WILL INCREASE SOUTHEASTERLY WINDS TO
SMALL CRAFT ADVISORY STRENGTH OVER MOST WATERS TODAY. AS THE FRONT
NEARS THE COAST THERE WILL BE SOME HOURS OF GALE FORCE WINDS OVER
THE COAST. SOME RECENT MODELS ALSO HAVE GALE FORCE WINDS FOR A FEW
HOURS SUNDAY MORNING FOR THE EAST ENTRANCE AND NORTHERN INLAND
WATERS. A GALE WARNING IS IN EFFECT FOR THE COAST AND A GALE WATCH
HAS BEEN ISSUED FOR THE EAST ENTRANCE AND NORTHERN INLAND WATERS.
FLOW APPEARS RELATIVELY LIGHT ON MONDAY AND TUESDAY. CURRENT MODELS
BRING ANOTHER FRONT TUESDAY NIGHT AND WEDNESDAY. SMALL CRAFT
ADVISORIES OR GALE WARNINGS MAY BE NEEDED FOR THIS SYSTEM. CHB
&&
.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED THE NEXT 7 DAYS.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR COASTAL
WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-
COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-
COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO
60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE
OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE
SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE
TO CAPE SHOALWATER OUT 10 NM.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 4 PM PST SUNDAY FOR
COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60
NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10
NM-COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10
TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT
GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO
CAPE SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT
GRENVILLE TO CAPE SHOALWATER OUT 10 NM.
SMALL CRAFT ADVISORY FOR ROUGH BAR FROM 3 PM THIS AFTERNOON TO 7
PM PST THIS EVENING FOR GRAYS HARBOR BAR.
GALE WATCH FROM LATE TONIGHT THROUGH SUNDAY AFTERNOON FOR EAST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA-NORTHERN INLAND
WATERS INCLUDING THE SAN JUAN ISLANDS.
SMALL CRAFT ADVISORY UNTIL 4 AM PST SUNDAY FOR EAST ENTRANCE
U.S. WATERS STRAIT OF JUAN DE FUCA-NORTHERN INLAND WATERS
INCLUDING THE SAN JUAN ISLANDS.
SMALL CRAFT ADVISORY UNTIL 4 PM PST SUNDAY FOR ADMIRALTY INLET-
WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
345 PM CST SAT DEC 26 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 345 PM CST SAT DEC 26 2015
AT 3 PM...A NORTHERN STREAM SHORT WAVE WAS MOVING THROUGH NORTHERN
MINNESOTA. AHEAD OF THIS WAVE...THERE IS WEAK 290K ISENTROPIC LIFT
AND OMEGA UP TO 850 MB. WITH NO ICE CRYSTAL SEEDING FROM ALOFT...
THIS WILL KEEP AREAS OF DRIZZLE OR FREEZING DRIZZLE CONTINUING
THROUGH 27.03Z. THE FREEZING DRIZZLE WILL BE MAINLY NORTH OF A
INTERSTATE 90. WITH ROAD TEMPERATURE RANGING FROM 33 TO 35F AND
APPLIED ROAD TREATMENTS...NOT ANTICIPATING TOO MANY ISSUES FOR
THOSE TRAVELING...THUS...NOT PLANNING ON ISSUING ANOTHER WINTER
WEATHER ADVISORY.
FOR TONIGHT AND SUNDAY...A CANADIAN HIGH WILL BUILD INTO THE
REGION. THIS WILL KEEP THE AREA DRY. WITH INCREASED SUBSIDENCE AND
DRY AIR ADVECTING INTO THE REGION...EXPECT SOME CLEARING TO OCCUR
ACROSS THE AREA LATE SUNDAY MORNING AND AFTERNOON. WITH SOME
SUNSHINE...TEMPERATURES WILL RANGE FROM THE MID 20S TO MID 30S.
THIS IS A COUPLE OF DEGREES ABOVE NORMAL.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 345 PM CST SAT DEC 26 2015
FROM MONDAY INTO MONDAY NIGHT...THE 26.12Z AND 26.18Z MODELS ARE
IN GOOD AGREEMENT THAT A CLOSED LOW WILL LIFT NORTH NORTHEAST FROM
MISSOURI INTO NORTHERN WISCONSIN AND UPPER MICHIGAN. WHILE IT IS
MOVING THROUGH THE UPPER MISSISSIPPI RIVER VALLEY...IT WILL BE
GRADUALLY FILLING. THIS WILL LIMIT THE WINDS AHEAD OF THE SYSTEM
TO 15 TO 25 MPH...AND FROM 10 TO 15 MPH ON TUESDAY. AS WITH THE
PREVIOUS COUPLE OF DAYS...THE MODELS CONTINUE TO STRUGGLE ON HOW
MUCH WARM AIR WILL ADVECT NORTHWARD AHEAD OF THE UPPER LEVEL LOW
ON MONDAY. THE NAM CONTINUES TO BRING THE WARMEST AIR ALOFT INTO
THE REGION. IF THIS SOLUTION VERIFIED...NORTHEAST IOWA AND
WESTERN WISCONSIN WOULD SEE A MIX OF RAIN...FREEZING RAIN...AND
SLEET FROM MONDAY MORNING THROUGH MID AFTERNOON...AND THEN IT
WOULD TRANSITION TO SNOW LATE MONDAY AFTERNOON AND CONTINUE INTO
MONDAY NIGHT. THE GFS CONTINUES TO BE THE COLDEST AND THE
PRECIPITATION WOULD BE SNOW FROM MONDAY INTO MONDAY NIGHT. SNOW
TOTALS WOULD RANGE FROM 4 TO 10 INCHES. MEANWHILE THE ECMWF WAS A
GOOD COMPROMISE BETWEEN THESE 2 SOLUTIONS AND IT WAS USED TO HELP
DELINEATE WHERE THERE WOULD BE THE BEST CHANCE OF A WINTRY MIX
WOULD OCCUR. IN THIS SCENARIO...IT WOULD OCCUR ACROSS THE EASTERN
PORTIONS OF NORTHEAST IOWA AND IN SOUTHWEST WISCONSIN. FREEZING
RAIN COULD ACCUMULATE UP TO A TENTH OF AN INCH OF ICE ACROSS
FAYETTE AND CLAYTON COUNTIES IN NORTHEAST IOWA AND GRANT COUNTY IN
SOUTHWEST WISCONSIN. SNOW TOTALS WOULD RANGE FROM 4 TO 8 INCHES.
AT THIS TIME THE HIGHEST TOTALS LOOK TO BE NORTH OF INTERSTATE 90.
WITH THE COLD AIR OVER THE CENTRAL AND NORTHERN PLAINS...THINKING
THAT IF THERE WAS ANY SHIFT TO OCCUR TO THIS LOW TRACK...IT WOULD
BE MORE LIKELY TO BE A BIT FURTHER NORTHWEST. JUST A SHIFT OF 100
MILES IN THIS DIRECTION WOULD RESULT IN MORE RAIN/FREEZING RAIN IN
SOUTHWEST WISCONSIN AND NORTHEAST IOWA...AND MORE OF A MIX FOR THE
REMAINDER OF THE AREA.
ON WEDENESDAY...ANOTHER COLD FRONT WILL MOVE THROUGH THE REGION.
WITH THIS SYSTEM HAVING MORE CONTINENTAL POLAR AIR MASS THAN THE
MARITIME POLAR AIR MASS THAT WE HAVE BECOME ACCUSTOMED TO THIS
WINTER...ONE OF THE COLDEST AIR MASSES OF THE 2015-16 WINTER WILL
MOVE INTO THE REGION. HIGHS ON NEW YEARS EVE AND DAY MAY NOT EVEN
REACH 20 DEGREES. EVEN THOUGH THE AIR MASS WILL WARM INTO THE
WEEKEND...TEMPERATURES WILL REMAIN NEAR TO SLIGHTLY BELOW NORMAL.
THIS CHANGE IN THE UPPER AIR FLOW IS DUE TO A STRONG COHERENT
MADDEN JULIAN OSCILLATION DISRUPTING THE STRONG EL NINO. THIS WILL
LIKELY LAST INTO THE FIRST WEEK OF THE NEW YEAR...AND THEN THE
STRONG EL NINO WILL ONCE AGAIN TAKE OVER AGAIN WITH TEMPERATURES
RETURN TO WARMER THAN NORMAL FOR MUCH OF JANUARY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1129 AM CST SAT DEC 26 2015
THE MAIN BAND OF PRECIPITATION IS JUST ABOUT TO THE MISSISSIPPI
RIVER AND EXPECT IT TO BE PAST KLSE BY 19Z. AFTER THAT...THE
26.15Z RAP AND THE 26.16Z RUNS OF THE HRRR AND CR-HRRR SUGGEST ANY
PRECIPITATION THROUGH THE AFTERNOON WILL BE LIGHT WITH THE
POSSIBILITY OF SOME LIGHT SNOW TO ROTATE THROUGH KRST WITH ALL THE
PRECIPITATION ENDING BY 00Z. PRIMARILY EXPECTING MVFR CEILINGS
THIS AFTERNOON INTO THE OVERNIGHT HOURS...BUT CANNOT RULE OUT SOME
IFR AT KRST IF THE LIGHT SNOW DOES GET IN THERE. SUBSIDENCE AND
DRYING BEHIND THE SHORT WAVE TROUGH WILL START TO MOVE IN LATE
TONIGHT INTO SUNDAY MORNING AND WILL BE ENOUGH TO BREAK UP THE
CLOUDS...BUT THE QUESTION BECOMES WHEN. THE 26.12Z NAM SUGGESTS
THIS COULD HAPPEN BEFORE 12Z...BUT THIS LOOKS RATHER AGGRESSIVE
AND WENT WITH THE TIMING SHOWN BY THE 26.09Z SREF MEAN BUFKIT
SOUNDINGS FOR THE MIDDLE OF SUNDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT
FOR WIZ054-055-061.
WINTER STORM WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY
NIGHT FOR WIZ017-029-032>034-041>044-053.
MN...WINTER STORM WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY
NIGHT FOR MNZ079-086>088-094>096.
IA...WINTER STORM WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT
FOR IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 231 PM CST SAT DEC 26 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A WARM
FRONT POSITIONED OVER THE MID-MISSISSIPPI VALLEY AND AN ARCTIC COLD
FRONT DRAPED ACROSS THE UPPER PENINSULA INTO CENTRAL MINNESOTA.
NORTHERN WISCONSIN LIES BETWEEN THESE TWO FEATURES IN A REGION OF
CONFLUENT MID-LEVEL FLOW. ALTHOUGH A MORE PERSISTENT BAND OF SNOW
EXISTS ALONG THE COLD FRONT NORTHWEST OF THE REGION...AREAS OF LIGHT
WINTRY PRECIP ARE PASSING OVER NORTH-CENTRAL AND NORTHEAST WISCONSIN
EARLY THIS AFTERNOON. SO FAR...NO REPORTS OF SLIPPERY ROADS WHERE
TEMPERATURES ARE BELOW FREEZING...GENERALLY NORTH OF A LINE FROM
MARSHFIELD TO IRON MOUNTAIN. THERE WERE SOME ISOLATED REPORTS OF
LIGHT ICING OVER SOUTHWEST WISCONSIN FROM EARLIER TODAY...SO NO
PLANS TO CHANGE HEADLINES AT THIS POINT. PRECIPITATION IS SHOWERY
IN NATURE...WHICH IS HAMPERING SNOWFALL ACCUMULATIONS ACROSS THE FAR
NORTH. SOME SLEET IS ALSO MIXING IN WITH THE LIGHT RAIN OVER
CENTRAL WISCONSIN. AS THE WINTRY PRECIP CONTINUES INTO
TONIGHT...PRECIP TRENDS AND IMPACTS REMAIN THE MAIN FORECAST
CONCERNS.
TONIGHT...A WEAK 850MB LOW WILL TRAVERSE THE REGION THROUGH EARLY
THIS EVENING. MID-LEVEL FGEN AHEAD OF THE LOW AND ALONG THE
TRAILING COLD FRONT...COMBINED WITH UPPER DIVERGENCE IN THE REAR
RIGHT QUAD OF A JET STREAK...WILL CONTINUE TO GENERATE LIGHT PRECIP
THROUGH THE LATE EVENING OR EARLY OVERNIGHT HOURS. PROGGED
SOUNDINGS CONTINUE TO INDICATE THAT TEMPERATURES ALOFT STRUGGLE TO
SATURATE ABOVE THE -10C ISOTHERM THIS EVENING. SO A WINTRY MIX OF
FREEZING DRIZZLE AND LIGHT SNOW REMAINS POSSIBLE NORTH OF A
MARSHFIELD TO IRON MOUNTAIN LINE. IMPACTS ARE TOUGH TO GAUGE...BUT
DID CUT DOWN SNOW ACCUMS TO 1-2 INCHES FOR THE FAR NORTH TONIGHT
GIVEN THE SHOWERY NATURE OF THE PRECIP. SOME LIGHT ICING COULD STILL
OCCUR THOUGH...ESPECIALLY WHEN TEMPERATURES FALL TONIGHT. PLENTY OF
OBS UPSTREAM OVER IOWA AND SOUTHERN MINNESOTA ALSO INDICATE POSSIBLE
DRIZZLE...WHICH WILL BE MOVING THROUGH DURING THE EVENING. THE
ENDING TIME OF THE ADVISORY LOOKS ABOUT RIGHT...DEPENDING UPON IF
ANY ICING CONDITIONS MATERIALIZES. ONCE THE PRECIP PULLS
OUT...COLDER AIR WILL FILTER IN FROM THE NORTHWEST. LIGHT LAKE
EFFECT SNOW SHOWERS WILL IMPACT VILAS COUNTY WITHOUT MUCH
ACCUMULATIONS. BUT LOW INVERSION HEIGHTS SHOULD BRING IN CLOUDS OFF
LAKE SUPERIOR TO REINFORCE THE CLOUDY CONDITIONS. LOWS IN THE MID
20S NORTH TO LOW 30S SOUTH.
SUNDAY...DRIER ARCTIC AIR WILL GRADUALLY SHIFT SOUTHEAST ACROSS THE
STATE...ORIGINATING FROM A 1040MB HIGH OVER THE NORTHERN PLAINS.
LIGHT SNOW SHOWERS AND FLURRIES WILL LIKELY IMPACT VILAS COUNTY
THROUGH THE DAY WITHOUT MUCH ACCUMULATIONS. OTHERWISE...EXPECTING A
RATHER CLOUDY START TO THE DAY...BUT BREAKS IN THE CLOUDS SHOULD
ONLY INCREASE THROUGH THE AFTERNOON. TEMPS WILL REMAIN RELATIVELY
STEADY ACROSS THE NORTH...AND ONLY WARM INTO THE MID 30S SOUTH.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY
ISSUED AT 231 PM CST SAT DEC 26 2015
A LOW PRESSURE SYSTEM WILL HOOK NORTH-NORTHEAST FROM SOUTHERN
TEXAS ON SUNDAY AND BE CENTERED OVER WISCONSIN BY EARLY TUESDAY.
THE POSITION OF THE "TEXAS SLINGER" TRACK WILL SIGNIFICANTLY
INFLUENCE PRECIPITATION TYPE...AND MODELS VARY ENOUGH ON THE TRACK
AND TIMING OF THIS SYSTEM TO REDUCE CONFIDENCE IN ISSUING A WINTER
STORM WATCH. HIGH PRESSURE RIDGING IN PLACE OVER THE NORTHERN
MIDWEST AHEAD OF THE APPROACHING LOW SHOULD HELP SQUEEZE THE
PRESSUE GRADIENT ACROSS OUR AREA AS THE LOW APPROACHES AND
HEIGHTENS EXPECTATIONS FOR GUSTY WINDS IN THE WISCONSIN MONDAY
NIGHT.
A SECOND SYSTEM IS EXPECTED TO AFFECT THE AREA LATE TUESDAY NIGHT
THROUGH WEDNESDAY EVENING...BRINGING A CHANCE OF LIGHT SNOW TO
THE REGION. TEMPERATURES WILL START OUT ABOVE NORMAL...BUT RETURN
CLOSER AND PERHAPS A FEW DEGREES BELOW NORMAL BY THE END OF NEXT
WEEK.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1137 AM CST SAT DEC 26 2015
A WEAK STORM SYSTEM WILL MOVE ACROSS THE AREA THROUGH
THE EVENING. TEMPERATURES REMAIN BELOW FREEZING FROM MARSHFIELD AND
STEVENS POINT TO IRON MOUNTAIN LATE THIS MORNING. AS PRECIPITATION
SPREADS ACROSS THE AREA THIS AFTERNOON...SNOW AND FREEZING DRIZZLE
WILL IMPACT AREAS NORTH OF THIS LINE. LIGHT ICING IS POSSIBLE HERE.
TO THE SOUTH...MAINLY RAIN/DRIZZLE IS EXPECTED. PRECIPITATION WILL
PULL OUT LATE THIS EVENING. BUT NORTH FLOW OFF LAKE SUPERIOR AND
LOW INVERSION HEIGHTS WILL SUPPORT IFR/MVFR BROKEN CIGS THROUGH
MIDDAY SUNDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR WIZ010-
011-018-019-030.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ005.
&&
$$
SHORT TERM.....MPC
LONG TERM......ML
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
220 PM CST SAT DEC 26 2015
.UPDATE...
ISSUED AT 220 PM CST SAT DEC 26 2015
THE REMAINING AREAS OF THE LIGHT SNOW AND FREEZING RAIN HAVE MOVED
EAST OF THE AREA. THERE COULD STILL BE A LITTLE BIT OF LIGHT
FREEZING DRIZZLE AT TIMES THROUGH THE AFTERNOON AS THERE IS STILL
SOME WEAK FRONTOGENESIS IN THE 850-700 MB LAYER...BUT THIS NOT
EXPECTED TO BE ENOUGH TO CAUSE ANY PROBLEMS.
UPDATE ISSUED AT 1237 PM CST SAT DEC 26 2015
THE MAIN BAND OF LIGHT SNOW AND FREEZING RAIN HAS BECOME CONFINED
FROM NORTHERN LA CROSSE AND MONROE COUNTIES NORTHWARD INTO TAYLOR
COUNTY. THERE HAS BEEN JUST ENOUGH FREEZING RAIN TO CREATE A LIGHT
COATING OF ICE ON UNTREATED SURFACES SO WILL CONTINUE THE ADVISORY
UNTIL AT LEAST THE MIDDLE OF THE AFTERNOON UNTIL THIS
PRECIPITATION MOVES OFF TO THE EAST. FARTHER TO THE WEST...NOT
MUCH GOING ON AT THIS POINT. THE 26.12Z NAM DOES SHOW A BIT OF
FRONTOGENESIS CONTINUING IN THE 850-700 MB LAYER WHICH IS HELPING
TO PRODUCE THE LIGHT SNOW ACROSS CENTRAL MINNESOTA. THE 26.16Z
HRRR SUGGESTS THERE IS A POSSIBILITY OF SOME OF THIS LIGHT SNOW
GETTING INTO SOUTHEAST MINNESOTA...SO HAVE LEFT SOME HIGHER
PRECIPITATION CHANCES IN THAT AREA...BUT NOT EXPECTING IT TO BE
ENOUGH TO CAUSE ANY PROBLEMS AND HAVE DROPPED THE ADVISORY FOR
SOUTHEAST MINNESOTA AND NORTHEAST IOWA.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 240 AM CST SAT DEC 26 2015
UPPER LEVEL SHORTWAVE TROUGH WAS LIFTING NORTHEAST INTO THE CENTRAL
PLAINS...PER LATEST WATER VAPOR IMAGERY...HELPING POWER AN AREA
OF SNOW AND RAIN ACROSS SOUTHWEST MN/WESTERN IA INTO THE PLAINS.
STRONG ISENTROPIC UPGLIDE WAS ALSO HAVING A HAND IN PRECIPITATION
PRODUCTION...WHICH WILL SLIDE ACROSS AND NORTHEAST OF THE AREA BY
00Z THIS EVENING. SOME FRONTOGENETIC BANDING...MORE NORTH...AS
WILL BE THE UPPER LEVEL JET DYNAMICS. SO LOCALLY...MUCH OF THE
PRECIPITATION WILL BE TIED TO THE LOW LEVEL WARMING. WHAT TYPE
WILL FALL WILL BE BASED ON WHETHER ICE IS AVAILABLE IN THE CLOUD
AND WHAT THE TEMP PROFILE LOOKS LIKE. MOSTLY...ITS A QUESTION OF
ICE.
TIME/HEIGHT X-SECTIONS AND BUFKIT SOUNDINGS SUGGEST ICE IS GOING TO
BE HARD TO COME BY FOR A BULK OF THE LOCAL FORECAST AREA...MAKING
DRIZZLE/RAIN...OR FREEZING DEPENDING ON SFC TEMPS...THE
PRECIPITATION TYPE. THE FARTHER WEST/NORTH YOU GO THE MORE LIKELY
THE CLOUD WILL BE DEEP ENOUGH FOR ICE...WITH SNOW THEN MOST
LIKELY. LIGHT ICING COULD OCCUR ON UNTREATED ROAD AND SIDEWALKS.
SNOW ACCUMULATIONS LOOK MINIMAL...WITH MOST IN NORTH-CENTRAL WI.
OVERALL...THE GREATER THREAT WILL BE THE POTENTIAL FOR ICING. WILL
CONTINUE THE WINTER WEATHER ADV AS IS FOR NOW.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 240 AM CST SAT DEC 26 2015
WELL...THE CONSISTENCY OF THE ECMWF MAY BE WINNING OUT FOR A STORM
SYSTEM SLATED TO IMPACT PARTS OF THE REGION MONDAY-MONDAY NIGHT. THE
PREVIOUS QUICK/MORE EAST GFS AND GEM HAVE NOW TRENDED TOWARD THE
FARTHER WEST SOLUTION OF THE EC...LENDING GREATER CONFIDENCE TO A
SWATH OF PRECIPITATION FOR MON/MON NIGHT.
CLOSED UPPER LOW WILL LIFT OUT OF TX SUNDAY NIGHT...DRIVING UP INTO
THE EASTERN GREAT LAKES MONDAY NIGHT. WHILE COMING CLOSER
TOGETHER...STILL SOME VARIANCES WITH THE SYSTEM/S SFC LOW
PLACEMENT...WITH THE EC OVER CENTRAL IA BY 06Z TUE AND THE GFS OVER
NORTHERN ILL AT THAT TIME. WEST-EAST ORIENTATED SLOPING
FRONTOGENETIC LIFT WITH STRONG LOW LEVEL THERMODYNAMICS LEADING THE
UPPER LEVEL LOW INTO THE REGION...AND THE LEFT EXIT REGION OF A 100+
KT UPPER LEVEL JET ENHANCING THE LIFT. UNLIKE THE RECENT
PRECIPITATION EVENTS WHERE ICE IN THE CLOUD HAS BEEN
QUESTIONABLE...SATURATION IS MUCH DEEPER AND THERE IS A FETCH OF
GULF MOISTURE TO PLAY WITH. WHAT IS A CONCERN IS THE AMOUNT OF LOW
LEVEL WARMING. THE NAM BRINGS A NOSE OF 800-850 MB WARM AIR
UPWARDS OF 7 C ACROSS PARTS OF THE AREA. THE GFS IS NOT AS A
ROBUST...ALTHOUGH ITS 00Z SOLUTION IS NOW TRENDING A BIT WARMER IN
THAT LAYER THAN ITS PREVIOUS RUNS. WITH COLD AIR IN PLACE AT THE
SFC BY THIS TIME...FREEZING RAIN/SLEET ENTER THE PICTURE...WITH
THE POTENTIAL FOR IMPACTFUL AMOUNTS. SEVERAL INCHES OF SNOW
ACCUMULATION ALSO LIKELY. AGAIN THOUGH - MUCH OF WHAT FALLS AND
WHERE IS GOING TO HINGE ON JUST HOW WARM THIS WARM LAYER
IS...COUPLED WITH THE POSITIONING OF THE SFC LOW. DIFFICULT
QUESTIONS TO ANSWER AT THIS TIME...BUT ITS A STORM SYSTEM THAT
WILL HAVE IMPACTS TO TRAVEL. IN ADDITION...IF ITS ENDS UP BEING
MORE FREEZING RAIN...WINDS LOOK STRONG AND GUSTY MONDAY. ICE
ACCUMULATIONS ON TREES AND POWERLINES WOULD OCCUR...AND WITH THOSE
WINDS...DAMAGE TO LIMBS/POWER LINES WOULD BE HIGHLY LIKELY. A
SCENARIO THAT BEARS A VERY CLOSE WATCH. WILL TAKE A MIDDLE OF THE
ROAD/CONSENSUS APPROACH TO PRECIPITATION CHANCES AND PRECIPITATION
TYPES FOR NOW. THINK A WINTER STORM WATCH WILL EVENTUALLY BE
NEEDED FOR A PORTION OF THE AREA IF CURRENT MODEL SOLUTIONS
PERSIST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1129 AM CST SAT DEC 26 2015
THE MAIN BAND OF PRECIPITATION IS JUST ABOUT TO THE MISSISSIPPI
RIVER AND EXPECT IT TO BE PAST KLSE BY 19Z. AFTER THAT...THE
26.15Z RAP AND THE 26.16Z RUNS OF THE HRRR AND CR-HRRR SUGGEST ANY
PRECIPITATION THROUGH THE AFTERNOON WILL BE LIGHT WITH THE
POSSIBILITY OF SOME LIGHT SNOW TO ROTATE THROUGH KRST WITH ALL THE
PRECIPITATION ENDING BY 00Z. PRIMARILY EXPECTING MVFR CEILINGS
THIS AFTERNOON INTO THE OVERNIGHT HOURS...BUT CANNOT RULE OUT SOME
IFR AT KRST IF THE LIGHT SNOW DOES GET IN THERE. SUBSIDENCE AND
DRYING BEHIND THE SHORT WAVE TROUGH WILL START TO MOVE IN LATE
TONIGHT INTO SUNDAY MORNING AND WILL BE ENOUGH TO BREAK UP THE
CLOUDS...BUT THE QUESTION BECOMES WHEN. THE 26.12Z NAM SUGGESTS
THIS COULD HAPPEN BEFORE 12Z...BUT THIS LOOKS RATHER AGGRESSIVE
AND WENT WITH THE TIMING SHOWN BY THE 26.09Z SREF MEAN BUFKIT
SOUNDINGS FOR THE MIDDLE OF SUNDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...04
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1237 PM CST SAT DEC 26 2015
.UPDATE...
ISSUED AT 1237 PM CST SAT DEC 26 2015
THE MAIN BAND OF LIGHT SNOW AND FREEZING RAIN HAS BECOME CONFINED
FROM NORTHERN LA CROSSE AND MONROE COUNTIES NORTHWARD INTO TAYLOR
COUNTY. THERE HAS BEEN JUST ENOUGH FREEZING RAIN TO CREATE A LIGHT
COATING OF ICE ON UNTREATED SURFACES SO WILL CONTINUE THE ADVISORY
UNTIL AT LEAST THE MIDDLE OF THE AFTERNOON UNTIL THIS
PRECIPITATION MOVES OFF TO THE EAST. FARTHER TO THE WEST...NOT
MUCH GOING ON AT THIS POINT. THE 26.12Z NAM DOES SHOW A BIT OF
FRONTOGENESIS CONTINUING IN THE 850-700 MB LAYER WHICH IS HELPING
TO PRODUCE THE LIGHT SNOW ACROSS CENTRAL MINNESOTA. THE 26.16Z
HRRR SUGGESTS THERE IS A POSSIBILITY OF SOME OF THIS LIGHT SNOW
GETTING INTO SOUTHEAST MINNESOTA...SO HAVE LEFT SOME HIGHER
PRECIPITATION CHANCES IN THAT AREA...BUT NOT EXPECTING IT TO BE
ENOUGH TO CAUSE ANY PROBLEMS AND HAVE DROPPED THE ADVISORY FOR
SOUTHEAST MINNESOTA AND NORTHEAST IOWA.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 240 AM CST SAT DEC 26 2015
UPPER LEVEL SHORTWAVE TROUGH WAS LIFTING NORTHEAST INTO THE CENTRAL
PLAINS...PER LATEST WATER VAPOR IMAGERY...HELPING POWER AN AREA
OF SNOW AND RAIN ACROSS SOUTHWEST MN/WESTERN IA INTO THE PLAINS.
STRONG ISENTROPIC UPGLIDE WAS ALSO HAVING A HAND IN PRECIPITATION
PRODUCTION...WHICH WILL SLIDE ACROSS AND NORTHEAST OF THE AREA BY
00Z THIS EVENING. SOME FRONTOGENETIC BANDING...MORE NORTH...AS
WILL BE THE UPPER LEVEL JET DYNAMICS. SO LOCALLY...MUCH OF THE
PRECIPITATION WILL BE TIED TO THE LOW LEVEL WARMING. WHAT TYPE
WILL FALL WILL BE BASED ON WHETHER ICE IS AVAILABLE IN THE CLOUD
AND WHAT THE TEMP PROFILE LOOKS LIKE. MOSTLY...ITS A QUESTION OF
ICE.
TIME/HEIGHT X-SECTIONS AND BUFKIT SOUNDINGS SUGGEST ICE IS GOING TO
BE HARD TO COME BY FOR A BULK OF THE LOCAL FORECAST AREA...MAKING
DRIZZLE/RAIN...OR FREEZING DEPENDING ON SFC TEMPS...THE
PRECIPITATION TYPE. THE FARTHER WEST/NORTH YOU GO THE MORE LIKELY
THE CLOUD WILL BE DEEP ENOUGH FOR ICE...WITH SNOW THEN MOST
LIKELY. LIGHT ICING COULD OCCUR ON UNTREATED ROAD AND SIDEWALKS.
SNOW ACCUMULATIONS LOOK MINIMAL...WITH MOST IN NORTH-CENTRAL WI.
OVERALL...THE GREATER THREAT WILL BE THE POTENTIAL FOR ICING. WILL
CONTINUE THE WINTER WEATHER ADV AS IS FOR NOW.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 240 AM CST SAT DEC 26 2015
WELL...THE CONSISTENCY OF THE ECMWF MAY BE WINNING OUT FOR A STORM
SYSTEM SLATED TO IMPACT PARTS OF THE REGION MONDAY-MONDAY NIGHT. THE
PREVIOUS QUICK/MORE EAST GFS AND GEM HAVE NOW TRENDED TOWARD THE
FARTHER WEST SOLUTION OF THE EC...LENDING GREATER CONFIDENCE TO A
SWATH OF PRECIPITATION FOR MON/MON NIGHT.
CLOSED UPPER LOW WILL LIFT OUT OF TX SUNDAY NIGHT...DRIVING UP INTO
THE EASTERN GREAT LAKES MONDAY NIGHT. WHILE COMING CLOSER
TOGETHER...STILL SOME VARIANCES WITH THE SYSTEM/S SFC LOW
PLACEMENT...WITH THE EC OVER CENTRAL IA BY 06Z TUE AND THE GFS OVER
NORTHERN ILL AT THAT TIME. WEST-EAST ORIENTATED SLOPING
FRONTOGENETIC LIFT WITH STRONG LOW LEVEL THERMODYNAMICS LEADING THE
UPPER LEVEL LOW INTO THE REGION...AND THE LEFT EXIT REGION OF A 100+
KT UPPER LEVEL JET ENHANCING THE LIFT. UNLIKE THE RECENT
PRECIPITATION EVENTS WHERE ICE IN THE CLOUD HAS BEEN
QUESTIONABLE...SATURATION IS MUCH DEEPER AND THERE IS A FETCH OF
GULF MOISTURE TO PLAY WITH. WHAT IS A CONCERN IS THE AMOUNT OF LOW
LEVEL WARMING. THE NAM BRINGS A NOSE OF 800-850 MB WARM AIR
UPWARDS OF 7 C ACROSS PARTS OF THE AREA. THE GFS IS NOT AS A
ROBUST...ALTHOUGH ITS 00Z SOLUTION IS NOW TRENDING A BIT WARMER IN
THAT LAYER THAN ITS PREVIOUS RUNS. WITH COLD AIR IN PLACE AT THE
SFC BY THIS TIME...FREEZING RAIN/SLEET ENTER THE PICTURE...WITH
THE POTENTIAL FOR IMPACTFUL AMOUNTS. SEVERAL INCHES OF SNOW
ACCUMULATION ALSO LIKELY. AGAIN THOUGH - MUCH OF WHAT FALLS AND
WHERE IS GOING TO HINGE ON JUST HOW WARM THIS WARM LAYER
IS...COUPLED WITH THE POSITIONING OF THE SFC LOW. DIFFICULT
QUESTIONS TO ANSWER AT THIS TIME...BUT ITS A STORM SYSTEM THAT
WILL HAVE IMPACTS TO TRAVEL. IN ADDITION...IF ITS ENDS UP BEING
MORE FREEZING RAIN...WINDS LOOK STRONG AND GUSTY MONDAY. ICE
ACCUMULATIONS ON TREES AND POWERLINES WOULD OCCUR...AND WITH THOSE
WINDS...DAMAGE TO LIMBS/POWER LINES WOULD BE HIGHLY LIKELY. A
SCENARIO THAT BEARS A VERY CLOSE WATCH. WILL TAKE A MIDDLE OF THE
ROAD/CONSENSUS APPROACH TO PRECIPITATION CHANCES AND PRECIPITATION
TYPES FOR NOW. THINK A WINTER STORM WATCH WILL EVENTUALLY BE
NEEDED FOR A PORTION OF THE AREA IF CURRENT MODEL SOLUTIONS
PERSIST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1129 AM CST SAT DEC 26 2015
THE MAIN BAND OF PRECIPITATION IS JUST ABOUT TO THE MISSISSIPPI
RIVER AND EXPECT IT TO BE PAST KLSE BY 19Z. AFTER THAT...THE
26.15Z RAP AND THE 26.16Z RUNS OF THE HRRR AND CR-HRRR SUGGEST ANY
PRECIPITATION THROUGH THE AFTERNOON WILL BE LIGHT WITH THE
POSSIBILITY OF SOME LIGHT SNOW TO ROTATE THROUGH KRST WITH ALL THE
PRECIPITATION ENDING BY 00Z. PRIMARILY EXPECTING MVFR CEILINGS
THIS AFTERNOON INTO THE OVERNIGHT HOURS...BUT CANNOT RULE OUT SOME
IFR AT KRST IF THE LIGHT SNOW DOES GET IN THERE. SUBSIDENCE AND
DRYING BEHIND THE SHORT WAVE TROUGH WILL START TO MOVE IN LATE
TONIGHT INTO SUNDAY MORNING AND WILL BE ENOUGH TO BREAK UP THE
CLOUDS...BUT THE QUESTION BECOMES WHEN. THE 26.12Z NAM SUGGESTS
THIS COULD HAPPEN BEFORE 12Z...BUT THIS LOOKS RATHER AGGRESSIVE
AND WENT WITH THE TIMING SHOWN BY THE 26.09Z SREF MEAN BUFKIT
SOUNDINGS FOR THE MIDDLE OF SUNDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ017-
029-033-034-041.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...04
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04