Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/17/15
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1243 AM MST TUE DEC 15 2015
.UPDATE...
ISSUED AT 1240 AM MST TUE DEC 15 2015
STRONG VORT LOBE COMING ACROSS AREA ATTM. INCREASED POPS ACROSS
PUEBLO AND EL PASO COUNTIES BASED ON CURRENT RADAR TRENDS AND
HRRR. NOTE THAT HRRR GUIDANCE IS BEHIND BY A COUPLE OF HOURS BASED
ON WHAT IS GOING ON NOW...BUT I BELIEVE IT HAS THE RIGHT TRENDS.
UPDATE ISSUED AT 958 PM MST MON DEC 14 2015
UPDATED TO INCORPORATE LATEST OBS AND SATELLITE DATA. INCREASED
POPS ACROSS SOUTHERN EL PASO COUNTY TO LIKELY AND PUEBLO COUNTY TO
SCATTERED FOR A SMALL WINDOW OVERNIGHT. MOORE
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 316 PM MST MON DEC 14 2015
...PERIOD OF SNOW AND WIND TO IMPACT CONTINENTAL DIVIDE AND PIKES
PEAK REGION...
A PACIFIC STORM SYSTEM TRACKING ACROSS SOUTHERN UTAH THIS AFTERNOON
WILL TRACK ACROSS SOUTHERN COLORADO TONIGHT...AND THEN TURN
NORTHEAST ACROSS NORTHWEST KANSAS INTO NEBRASKA ON TUESDAY. THIS
TRACK IS NOT VERY GOOD FOR SNOWFALL ACROSS MOST OF SOUTHERN COLORADO.
HOWEVER...IT IS A GOOD TRAJECTORY FOR SNOW ALONG THE CONTINENTAL
DIVIDE...AND IT IS FAR ENOUGH SOUTH TO BRING A PERIOD OF WIND DRIVEN
SNOW TO NORTHERN PARTS OF THE PIKES PEAK REGION...PARTICULARLY THE
NORTHERN PARTS OF TELLER AND EL PASO COUNTIES ALONG THE PALMER
DIVIDE. THE HEAVIEST ACCUMULATION PERIOD FOR THE CONTINENTAL DIVIDE
WILL VARY FROM SOUTH TO THE NORTH ALONG THE DIVIDE. THE SOUTHWEST
MOUNTAINS WILL SEE THE GREATEST ACCUMULATIONS THIS AFTERNOON INTO
THIS EVENING. THE GREATEST ACCUMULATION PERIOD FOR THE CENTRAL
MOUNTAINS WILL BE OVERNIGHT INTO TUESDAY. FOR THE PIKES PEAK AND
PALMER DIVIDE...SNOWFALL IS EXPECTED TO START AFTER MIDNIGHT...BE
HEAVIEST BETWEEN 3 AM AND 9 AM...AND THEN GRADUALLY DECREASE THROUGH
THE DAY.
THE CONTINENTAL DIVIDE WILL LIKELY DO THE BEST IN TERMS OF SNOWFALL
ACCUMULATION WITH THIS STORM. ELEVATIONS ABOVE 10000 FEET ALONG THE
DIVIDE WILL GENERALLY SEE 8 TO 12 INCHES BY TUESDAY EVENING WITH
LOCALLY HEAVIER AMOUNTS POSSIBLE. NORTHERN PARTS OF TELLER AND EL
PASO COUNTIES ALONG THE PALMER DIVIDE COULD SEE 2 TO 5 INCHES OF
SNOW WITH LOCALLY HEAVIER AMOUNTS POSSIBLE. IN ADDITION...NORTH
WINDS 15 TO 30 GUSTING TO AROUND 40 MPH AT TIMES WILL RESULT IN
AREAS OF BLOWING SNOW AND REDUCED VISIBILITIES...CREATING HAZARDOUS
TRAVEL CONDITIONS. COMMUTERS ACROSS NORTHERN TELLER AND EL PASO
COUNTIES SHOULD PLAN ON WINTER DRIVING CONDITIONS FROM LATE TONIGHT
THROUGH TUESDAY. THIS IS ALSO TRUE FOR ANYONE COMMUTING OVER THE
CONTINENTAL DIVIDE PASSES DURING THE NEXT 24 HOURS.
FOR EVERYBODY ELSE...THIS DOESN`T LOOK LIKE A BIG SNOWFALL MAKER.
THERE COULD BE A FEW INCHES ALONG THE HIGHER ELEVATIONS OF THE
EASTERN MOUNTAINS WITH SOME SPOTTY LIGHT ACCUMULATIONS ACROSS THE
LOWER ELEVATIONS. BUT...IN GENERAL...JUST A FEW PASSING FLURRIES AT
BEST. WHAT THE STORM WILL BRING TO ALL AREAS IS SOME WIND AND COLDER
TEMPERATURES. GUSTY WINDS ON TUESDAY...COUPLED WITH TEMPERATURES 10
TO 15 DEGREES BELOW AVERAGE...WILL LEAD TO A RATHER RAW DAY ACROSS
MUCH OF SOUTHERN COLORADO.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 316 PM MST MON DEC 14 2015
SNOW WILL WIND DOWN TUESDAY NIGHT...THOUGH NORTHWEST FLOW WILL
KEEP SOME SCATTERED OROGRAPHIC SNOW SHOWERS CONTINUING ALONG THE
CONTDVD. NEXT FAST MOVING SYSTEM DROPS DOWN IN NORTHWEST FLOW
BRINGING ANOTHER QUICK SHOT OF SNOW TO THE CONTDVD ON WEDNESDAY.
SNOWFALL AMOUNTS AT THIS POINT LOOK FAIRLY LIGHT WITH THIS NEXT
SYSTEM. THIS ALSO SENDS ANOTHER COLD FRONT THROUGH THE PLAINS WEDNESDAY
NIGHT/EARLY THURS. STILL SOME DIFFERENCES IN THE MODELS ACROSS THE
PLAINS...WITH GFS DEPICTING A QUICK SHOT OF SNOW AND NAM12
REMAINING FAIRLY DRY. BEST CHANCE LOOKS TO BE ACROSS EXTREME
NORTHERN PORTIONS OF THE SOUTHEAST PLAINS FOR NOW...AND WILL
MAINTAIN ISOLATED POPS FOR THAT AREA. QUICK STORM MOVEMENT SHOULD
KEEP ANY SPOTTY ACCUMULATIONS ON THE LIGHT SIDE. TEMPERATURES ON
THURSDAY WILL PROBABLY NOT MAKE IT MUCH ABOVE FREEZING ACROSS THE
PLAINS.
UPPER RIDGE REBUILDS FOR FRIDAY INTO THE WEEKEND WITH TEMPERATURES
RETURNING TO ABOVE NORMAL. THEN ANOTHER FAST MOVING SYSTEM
CROSSES THE CO ROCKIES SUNDAY INTO MONDAY BRINGING ANOTHER QUICK
SHOT OF SNOW TO THE MOUNTAINS. -KT
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1024 PM MST MON DEC 14 2015
SHOULD SEE SNOW MOVE INTO THE KCOS AREA AROUND 09Z WITH DECREASED
VSBY AND CIGS INTO LATE MORNING...MAINLY MVFR CONDITIONS BUT WL
PROBABLY IFR AT TIMES. NORTHERLY WINDS ARE ALSO EXPECTED TO
INCREASE AT KCOS. KPUB MAY SEE SNOW IN THE VCNTY BY 10Z...BUT
PROBABLY A BETTER CHC TOWARD 12-14Z WITH DECREASED VSBY AND CIGS
IN THE MVFR CATEGORY AND MAY AT TIMES BE IFR INTO LATE MORNING.
NW TO N WINDS WL INCREASE AT KPUB LATER TONIGHT. KALS WL HAVE THE
POTENTIAL FOR SOME SNOW IN THE VCNTY TONIGHT THRU TUE
MORNING...WHICH WL PROBABLY RESULT IN MVFR CONDITIONS AT TIMES.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ058-
060-081-082-084.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR COZ066.
WINTER STORM WARNING UNTIL NOON MST TODAY FOR COZ068.
&&
$$
UPDATE...HODANISH
SHORT TERM...LW
LONG TERM...KT
AVIATION...28
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
910 PM MST MON DEC 14 2015
.UPDATE...
ISSUED AT 859 PM MST MON DEC 14 2015
STG UPPER LEVEL LOW OVER SWRN CO WILL MOVE INTO SERN CO BY 12Z AND
THEN LIFT NNE INTO SWRN NE BY 21Z TUE. SHORT RANGE DATA CONTINUES
TO SUGGEST HEAVY SNOW WILL OCCUR FURTHER WEST THAN EARLIER SHOWN
ALONG THE FRONT RANGE INTO THE FOOTHILLS AS LOW LEVEL FLOW WILL
HAVE A MORE NELY COMPONENT FM 09Z THRU 15Z AND THEN SWITCH TO MORE
NLY THEREAFTER. SINCE RAP AND HRRR HAVE BEEN RATHER CONSISTENT
SINCE MID AFTN WITH THESE TRENDS HAVE DECIDED TO UPGRADE TO A
WARNING ALONG THE FRONT RANGE URBAN CORRIDOR AND PALMER DIVIDE.
WILL ISSUE ADVISORIES FOR THE FOOTHILLS AND MTN AREAS ALONG AND
SOUTH OF I-70 AS WELL.
UPDATE ISSUED AT 547 PM MST MON DEC 14 2015
LATEST SHORT TERM DATA FM HRRR AND RAP ARE SHIFTING AXIS OF
HEAVIER SNOW FURTHER WEST INTO THE FOOTHILLS AND ALONG THE FRONT
RANGE URBAN CORRIDOR. IN ADDITION SREF PLUME DATA IS SHOWING
AVERAGE AMOUNTS UP TO 6 INCHES OVER MUCH OF THE URBAN CORRIDOR AS
WELL. THIS IS DUE TO LOW LVL FLOW BECOMING MORE NELY AFTER
MIDNIGHT WHICH LASTS THRU SUNRISE. IN ADDITION THERE WILL BE
DECENT MID LVL ASCENT AND FAVORABLE LAPSE RATES AS WELL. THUS
SNOWFALL AMOUNTS COULD MEET WARNING CRITERIA ALONG THE FRONT RANGE
URBAN CORRIDOR. AT THIS POINT WILL CONTINUE TO MONITOR TRENDS THE
NEXT FEW HOURS BEFORE UPGRADING OR ADDING ADVISORIES.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 257 PM MST MON DEC 14 2015
A LARGE UPPER LOW THAT WILL BE RESPONSIBLE FOR TONIGHT THROUGH
TUESDAYS WINTER STORM IS CURRENTLY SPINNING OVER UTAH. WATER VAPOR
AND IR SATELLITE SHOWING GOOD LIFT AHEAD OF IT OVER WESTERN
COLORADO. THIS AREA OF LIFT WILL PUSH EAST....WITH UPWARD QG
VERTICAL VELOCITIES OF 40-50 MB/HR EXPECTED OVERNIGHT...ACROSS
NORTHERN COLORADO. SNOW IS ALREADY PUSHING INTO TO THE NORTHERN
MOUNTAINS...WITH THE ADVISORY FOR ZONES 31 AND 33 BEGINNING AT 6
PM THIS EVENING. SNOW WILL PUSH EAST THROUGH THE EVENING...WITH A
FEW LIGHT SNOW SHOWERS OVER THE URBAN CORRIDOR POSSIBLE AFTER 8 OR
9 PM. NOT EXPECTING TO SEE MUCH ACCUMULATING SNOW FOR THE PLAINS
THOUGH UNTIL AFTER MIDNIGHT. RECENT MODEL GUIDANCE HAS INCREASED
THE MOISTURE WITH THIS SYSTEM AS WELL AS THE QG LIFT...AND BY
SEEING SOME OF THE SNOW ITS BEEN PRODUCING ALREADY OVER
UTAH...HAVE INCREASED THE EXPECTED SNOWFALL FOR THE PLAINS. LATEST
TWO RUNS OF THE NAM GUIDANCE PUTS ALMOST HALF AN INCH OF LIQUID
ALONG AND EAST OF THE URBAN CORRIDOR BETWEEN MIDNIGHT AND TUESDAY
MORNING. HAVE INCREASED AMOUNTS SLIGHTLY TO ACCOMMODATE THIS
TREND. NORTHERLY WINDS WILL INCREASE OVERNIGHT BUT ESPECIALLY
TUESDAY. THIS WILL NORMALLY DOWNSLOPE THE NORTHERN FRONT RANGE
URBAN CORRIDOR...BUT HAVE SIDED WITH THE MODERATE TO STRONG AMOUNT
OF QG TO OVERCOME SOME OF THIS. THEREFORE...EXPECTING 2 TO 5
INCHES OF SNOW ALONG THE URBAN CORRIDOR...GREATER AMOUNTS TO THE
NORTH AND EAST....THEN EXPECTING 3 TO 7 INCHES OVER THE FAR
NORTHEAST PLAINS. COMBINING THE INCREASING NORTHERLY WINDS WITH
GUSTS OF 25 TO 40 MPH ACROSS THE PLAINS...HAVE DECIDED TO ISSUE AN
ADVISORY FOR MOST OF THE URBAN CORRIDOR AND A WARNING FOR THE
NORTHEAST PLAINS. HAVE LEFT OUT ZONE 39 INCLUDING BOULDER AND
GOLDEN AS THE WINDS WILL BE MUCH LIGHTER AND LESS SNOW IS
EXPECTED. ZONE 41...THE PALMER DIVIDE WAS INCLUDED DUE TO THE
STRONG WINDS THAT WILL PRODUCE BLOWING SNOW...EVEN THOUGH ONLY 2
TO 4 INCHES OF SNOW IS EXPECTED THERE. EXPECT TUESDAYS WEATHER TO
BE DIFFICULT TO TRAVEL IN WITH THE BLOWING AND DRIFTING SNOW AS
WELL. TEMPERATURES WILL DROP INTO THE LOW TO MID 20S TONIGHT AND
BARELY WARM IF AT ALL TOMORROW. THIS WILL CREATE WIND CHILL
TEMPERATURES AROUND 10 DEGREES FOR THE EASTERN PLAINS.
FOR THE MOUNTAINS...STILL EXPECTING 6 TO 12 INCHES FOR THE NORTHERN
MOUNTAINS AND 5 TO 10 INCHES FOR THE MOUNTAINS ALONG AND SOUTH OF I-
70. HIGH MOUNTAIN VALLEYS AND FOOTHILLS SHOULD SEE 3 TO 6
INCHES...WITH SLIGHTLY HIGHER AMOUNTS POSSIBLE OVER NORTH PARK AND
THE NORTHERN FOOTHILLS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 257 PM MST MON DEC 14 2015
THE UPPER LEVEL LOW WILL BE MAKING ITS WAY OFF TO THE NE ENDING
SNOWFALL ON THE PLAINS BY WEDNESDAY MORNING. MODELS INDICATING
DOWNSLOPING OVER THE FOOTHILLS HELPING TO END SNOW AND KEEP
TEMPERATURES SLIGHTLY WARMER THAN FURTHER EAST...ALTHOUGH STILL
EXPECT TEMPERATURES TO STAY AROUND FREEZING. SNOW WILL REMAIN IN
THE MOUNTAINS UNDER A MOIST NW FLOW WITH AMOUNTS WILL BE VERY
LIGHT.
WEDNESDAY NIGHT INTO THURSDAY...A WEAK WAVE EMBEDDED IN THE FLOW
WITH AN UPPER LEVEL JET AND SOME WEAK QG WILL BRING INCREASING SNOW
AMOUNTS TO THE MOUNTAINS BY LATE WEDNESDAY NIGHT AND LIGHT SNOWFALL
FOR THE FRONT RANGE BY THURSDAY AFTERNOON. NAM AND GFS STILL
INDICATING SOME DOWNSLOPING THROUGH THURSDAY MORNING BUT UPPER LEVEL
JET AND QG COULD BE ENOUGH LIFT TO BRING LIGHT SNOW BY THE
AFTERNOON. WILL MAINTAIN A SLIGHT CHANCE WITH LITTLE ACCUMULATION IN
THIS AREA. TEMPERATURES WILL STAY BELOW NORMAL WITH HIGHS DROPPING
INTO THE 20S ON THURSDAY FOR THE PLAINS AND LOWS OVERNIGHT IN THE
LOW TEENS.
FRIDAY WILL BE A TRANSITIONAL DAY AS THE WAVE AND ACCOMPANYING JET
MOVE EASTWARD AND AN UPPER LEVEL RIDGE BUILDING IN FROM THE WEST.
THE PLAINS WILL BE DRY AS A LEE SIDE TROUGH SETS UP WITH TEMPERATURE
REBOUNDING BACK INTO THE 40S. THERE IS STILL SOME LINGERING MOISTURE
IN THE NW FLOW SO WILL MAINTAIN LIGHT POPS FOR THE MOUNTAINS BUT
SNOW WILL BE VERY LIGHT AND ENDING BY FRIDAY AFTERNOON.
FOR THE WEEKEND THE UPPER LEVEL RIDGE MOVES IN TURNING FLOW MORE
SOUTHWESTERLY. THIS WILL START A DRIER AND WARMER TREND TO THE
FORECAST. TEMPERATURES FOR SATURDAY AND SUNDAY WILL BE IN THE UPPER
40S TO LOWER 50S FOR THE PLAINS. FOR THE MOUNTAINS THE NEXT CHANCE
FOR SNOW WILL BE SUNDAY EVENING AS MOISTURE INCREASES AHEAD OF THE
NEXT SYSTEM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 859 PM MST MON DEC 14 2015
THREAT FOR HEAVIER SNOWFALL HAS INCREASED BASED ON LATEST DATA. MOST
LIKELY TIME FOR HEAVY SNOW WILL BE BETWEEN 10Z AND 16Z WITH
SNOWFALL UP TO ONE INCH PER HOUR AT TIMES. OTHERWISE FM 16Z-20Z
SNOW WILL BE OF LIGHTER INTENSITY. TOTAL SNOW AMOUNTS UP TO 6
INCHES WILL CERTAINLY BE POSSIBLE BY 18Z. NORTH WINDS OF 10 TO 20
MPH WILL DEVELOP BY SUNRISE WITH SOME GUSTS UP TO 30 MPH THROUGH
EARLY AFTERNOON SO THERE WILL BE BLOWING SNOW AND POOR
VISBILITIES.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 5 AM TO 5 PM MST TUESDAY FOR COZ042-
044-048>051.
WINTER WEATHER ADVISORY FROM 1 AM TUESDAY TO 2 PM MST WEDNESDAY
FOR COZ035-036.
WINTER WEATHER ADVISORY UNTIL 5 PM MST TUESDAY FOR COZ031-033-
034.
WINTER STORM WARNING FROM 1 AM TO 2 PM MST TUESDAY FOR
COZ038>041-043-045.
WINTER WEATHER ADVISORY FROM 5 AM TO 5 PM MST TUESDAY FOR COZ046.
&&
$$
UPDATE...RPK
SHORT TERM...KRIEDERMAN
LONG TERM...BOWEN
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
948 PM EST WED DEC 16 2015
.SYNOPSIS...
CANADIAN HIGH PRESSURE NOSING DOWN INTO OUR REGION WILL MOVE OFFSHORE
TONIGHT, FOLLOWED BY A COLD FRONTAL PASSAGE THURSDAY NIGHT, AS WAVES
OF LOW PRESSURE MOVING ALONG IT. HIGH PRESSURE WILL BEGIN TO BUILD
INTO THE REGION ON FRIDAY FROM THE SOUTHERN PLAINS, FINALLY SETTLING
OVER THE MIDDLE ATLANTIC ON SUNDAY. A WEAK COLD FRONT WILL CROSS OUR
REGION ON MONDAY NIGHT, THEN RETURN NORTH AS A WARM FRONT ON TUESDAY
NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
ONLY A FEW ADJUSTMENTS TO TEMPS/DEWPOINTS NEEDED AT LATE EVENING
WITH THE MAINLY CLOUDY CONDITIONS ACROSS THE REGION. HRRR AND RAP
GUIDANCE HAS BEEN CORRECT IN SUGGESTING SOME LIGHT RAIN/DRIZZLE
COMING IN OFF THE OCEAN ACROSS LONG ISLAND AND NORTHEAST NJ. WE
HAVE KEPT SOME LOW POPS IN PLACE FOR OUR NORTH/EAST NJ ZONES AND
COASTAL WATERS OVER THE NEXT FEW HOURS AS A RESULT. IN ADDITION,
WE ALSO BACKED OFF A BIT ON POPS AND SOME LIGHT RAIN ADVANCING IN
FROM THE SOUTHWEST AHEAD OF AN APPROACHING FRONTAL BOUNDARY TOWARD
DAYBREAK THURSDAY BASED ON THE LATEST HI-RES GUIDANCE.
PREVIOUS DISCUSSION...LOW CLOUD/STCU HAS BEEN INCREASING AND
FILLING IN OVER NRN NJ AND THE DELMARVA...SO MOST OF THE FCST AREA
IS NOW CLOUDY. THE SFC HIGH PRES RIDGE WILL CONTINUE TO MOVE
GRADUALLY OFFSHORE AND WINDS HAVE ALREADY VEERED TO THE E/SE. THIS
FLOW PATN WILL CONTNUE TO BRING LOW CLODUS AND MOISTURE ACROSS THE
REGION FOR TONIGHT SO WE EXPECT CLOUDS TO PERSIST TONIGHT...THO
SOME GUIDANCE SUGGESTS PARTIAL CLEARING FOR A TIME OVER DELMARVA.
THE CLOUD COVER WILL PREVENT TEMPS FROM FALLING MORE THAN A FEW
DEGREES OVERNIGHT.
THE CLOUDS ARE RATHER SHALLOW AND THE ATMOS IS QUITE DRY ABOVE THE
INVERSION AT 900-850 HPA. SO LITTLE IF ANY PCPN IS EXPECTED
OVERNIGHT...ALTHO SEVERAL MODELS ARE INDICATING A BAND OF LIGHT RAIN
DEVELOPING NWWD OFF THE ATLANTIC INTO THE NYC AREA AND NE NJ. RADAR
DOES INDICATE SOME PCPN S OF LONG IS... AND WE HAVE KEPT CHC POPS
OVERNIGHT FOR THAT AREA. ALSO...RAIN WILL BE APPROACHING FROM THE SW
AHEAD OF THE NEXT FRONTAL SYSTEM BUT WE DON`T EXPECT MUCH EAST OF
NRN CHES BAY UNTIL AFTER SUNRISE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
MOST GUIDANCE SUGGESTS RAIN WILL RAPIDLY OVERSPREAD THE AREA FROM SW
TO NE THURSDAY MORNING AS INCREASING SWLY FLOW ALOFT BRINGS DEEPER
MOISTURE ACROSS THE AREA. AS THE FAIRLY STRONG COLD FRONT APPROACHES
FROM THE WEST...A WAVE OF LOW PRESSURE IS FCST TO DEVELOP ALONG OR
JUST AHEAD OF THE FRONTAL ZONE AND MOVE RAPIDLY NEWD ACROSS DELMARVA
DURING THE AFTN. THE BEST UVV AND LIKELY HEAVIEST RAIN SHOULD BE
AHEAD OF THIS WAVE DURING THE AFTN. WITH LOW LEVEL WARM ADVECTION
AHEAD OF THE FRONT...MAX TEMPS ON THURS SHOULD BE A FEW DEGREES
WARMER THAN TODAY...ESPECIALLY S AND E OF PHL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
LONG-WAVE MID-LEVEL TROUGH DIGS IN THE EAST ON FRIDAY AND SATURDAY,
LIFTING INTO THE CANADIAN MARITIMES BY SUNDAY. THE MID-LEVEL RIDGE
WILL CREST OVER THE MIDDLE ATLANTIC SUNDAY NIGHT, WITH A SOUTHWEST
ALOFT SETTING UP THEREAFTER. AFTER NEAR "AVERAGE" TEMPERATURES THIS
WEEKEND, ABOVE NORMAL TEMPERATURES ARE EXPECTED TO RETURN NEXT WEEK.
THURSDAY NIGHT AND FRIDAY...A COLD FRONT WILL MOVE SLOWLY OFFSHORE,
WITH POPS FOR RAIN SHOWERS DECREASING FROM WEST TO EAST THU NIGHT.
ON FRIDAY, WE KEPT POPS OVER EASTERN NJ AND SOUTHERN DE, WHERE SOME
OVERRUNNING TAKES PLACE AS, LOW PRESSURE MOVES ALONG AFOREMENTIONED
FRONT.
FRIDAY NIGHT AND SATURDAY...CYCLONIC FLOW ALOFT AS STRONG COLD AIR
ADVECTION TAKES PLACE. THERE WILL BE PARTIAL CLEARING FRIDAY NIGHT
WITH PARTLY SUNNY SKIES EXPECTED FOR SATURDAY. WITH THE TRAJECTORY
OFF THE GREAT LAKES, CANNOT RULE OUT SOME SNOW SHOWERS MOVING INTO
THE POCONOS, WITH THE CURRENT FORECAST REFLECTING THIS. STEEP LOW-
LEVEL LAPSE RATES WILL ALSO LEAD TO NORTHWEST GUSTINESS, UP TO 35
MPH AT TIMES. HIGH TEMPERATURES WILL RANGE FROM THE LOWER 30S TO
LOWER 40S, MAKING FOR WIND CHILL FACTORS WILL BE IN THE 20S.
SUNDAY AND MONDAY...HIGH PRESSURE CRESTS OVER THE REGION ON SUNDAY,
WITH A RETURN SOUTHWEST FLOW ON MONDAY. THERE IS A LOW POTENTIAL OF
FOG BOTH MORNINGS, ESPECIALLY NORTHWEST OF I-95. OTHERWISE, MOSTLY
SUNNY ON SUNDAY AND DRY. A WEAK COLD FRONT APPROACHING WILL LEAD TO
INCREASING CLOUDS AND THE CHANCE OF RAIN SHOWERS ON MONDAY.
MONDAY NIGHT THROUGH WEDNESDAY...A WEAK COLD FRONT CROSSES THE AREA
MONDAY NIGHT, ONLY TO MOVE NORTHWARD AS A WARM FRONT TUESDAY NIGHT.
A WAVE OF LOW PRESSURE MAY MOVE ALONG THIS FRONT ON WEDNESDAY, WITH
THE POSSIBILITY OF HEAVIER RAIN, ALTHOUGH UNCERTAIN GIVEN THE DAY 7
TIME FRAME. OVERALL, A MOIST SOUTHWEST FLOW DURING THIS PERIOD MAY
INHIBIT TEMPERATURES FROM REACHING THEIR FULL /RECORD/ POTENTIAL.
THIS WAS NOT THE CASE THIS PAST WEEKEND INTO EARLIER THIS WEEK AS
THE WAS RIDGE OVERHEAD WITH SUBSEQUENT SUBSIDENCE.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY, AND SURROUNDING AREAS.
TONIGHT...CEILINGS CONTINUE TO HOVER RIGHT AROUND THE VFR/MVFR
THRESHOLD AT MOST TERMINALS. HOWEVER, WITH THE CONTINUING ONSHORE
LOW- LEVEL FLOW...CIGS ARE EXPECTED TO LOWER INTO MVFR RANGE INTO
THE OVERNIGHT HOURS. LIGHT BUT PERSISTENT ESE WINDS WILL CONTINUE.
ON THURSDAY...RAIN WILL MOVE IN RAPIDLY FROM THE SW DURING THE
MORNING. CONDS MAY BE LOWER-END MVFR BY THE TIME THE RAIN STARTS AND
WILL LIKELY DETERIORATE FURTHER FROM THERE INTO THE IFR RANGE BY MID
DAY. WINDS WILL BE FROM THE SE BUT SHOULD REMAIN GENLY LESS THAN 10
KT. A COLD FRONT WILL CROSS THE AREA LATE IN THE DAY WITH AN ASSOCD
WIND SHIFT TO THE WEST.
OUTLOOK...
THURSDAY NIGHT AND FRIDAY...MVFR POSSIBLE IN SHRA...OTHERWISE VFR.
FRIDAY NIGHT AND SATURDAY...VFR CONDIITONS. NORTHWEST WIND GUSTS TO
30 KNOTS POSSIBLE AT ALL TERMINALS.
SATURDAY NIGHT THRU SUNDAY NIGHT...VFR CONDITIONS EXPECTED.
MONDAY...MVFR IN SHRA...OTHERWISE VFR.
&&
.MARINE...
CONDS SHOULD REMAIN SUB-SCA FOR TONIGHT AND THURSDAY. A SFC RIDGE OF
HIGH PRES WILL MOVE OFFSHORE TONIGHT CAUSING WINDS TO VEER FROM NE
TO SE. WINDS TONIGHT SHOULD REMAIN AROUND 10 KT. ON THURSDAY A WAVE
OF LOW PRES WILL MOVE NEWD ACRS THE COASTAL WATERS DURING THE AFTN.
THERE WILL LIKELY BE PERIODS OF HEAVY RAIN WITH ASSOCIATED AREAS OF
REDUCED VSBY.
OUTLOOK...
THURSDAY NIGHT THRU FRIDAY...SUB SMALL CRAFT ADVISORY /SCA/
CONDITIONS EXPECTED.
FRIDAY NIGHT THRU SATURDAY NIGHT...NORTHWEST WINDS ARE EXPECTED TO
REACH SCA CRITERIA. THERE IS ALSO THE POTENTIAL FOR GALE FORCE
GUSTS.
SUNDAY...NORTHWEST WINDS ARE EXPECTED TO WEAKEN BUT MAY REMAIN AT
SCA CRITERIA.
MONDAY...THERE IS A LOW PROBABILITY THAT SOUTHWEST WINDS MAY REACH
SCA CRITERIA.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANCK
NEAR TERM...AMC/KLINE
SHORT TERM...AMC
LONG TERM...FRANCK
AVIATION...AMC/FRANCK/KLINE
MARINE...AMC/FRANCK
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1121 PM EST MON DEC 14 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE INTO SOUTHEAST CANADA OVERNIGHT. AN
ASSOCIATED COLD FRONT WILL CROSS THE MID ATLANTIC REGION
OVERNIGHT. THE LOW WILL CONTINUE EASTWARD THROUGH NOVA SCOTIA ON
TUESDAY FOLLOWED BY WEAK HIGH PRESSURE ON WEDNESDAY. A STRONGER
COLD FRONT WILL CROSS THE REGION LATE THURSDAY OR THURSDAY
NIGHT...FOLLOWED BY SEASONABLY COLD HIGH PRESSURE FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
RECORD WARMTH WAS EXPERIENCED EARLIER TODAY DURING THE DAYTIME
HOURS AS SKIES CLEARED OUT FOR A TIME ALLOWING QUICK TEMPERATURE
RISES ACROSS THE REGION. LATE THIS EVENING, WITH AN INCREASING
SOUTHWESTERLY FLOW AND LOW LEVEL JET, WE ARE AGAIN SEEING A RISE
IN TEMPERATURES ACROSS MUCH OF THE FORECAST AREA, AND NEAR OR
RECORD HIGHS ARE POSSIBLE FOR TUESDAY JUST AFTER MIDNIGHT BEFORE A
COLD FRONT CROSSES THE REGION DURING THE EARLY MORNING.
A STRONG COLD FRONT CONTINUES TO APPROACH FROM THE WEST LATE THIS
EVENING, AND AHEAD OF IT, SOME SPOTTY SHOWERS CONTINUE ACROSS THE
REGION, ESPECIALLY ACROSS THE NORTHERN HALF OF THE FORECAST AREA.
THERE WAS SOME INSTABILITY ALOFT EARLIER THIS EVENING, AND AT
LEAST ONE LIGHTNING STRIKE WAS NOTED AROUND THE LEHIGH VALLEY.
SINCE THEN, HOWEVER, ONLY SHOWERS HAVE PERSISTED ACROSS THE
REGION, AND WE THEREFORE HAVE REMOVED THE MENTION OF THUNDER FOR
THE REST OF THE NIGHT. THE HRRR AND RAP CONTINUE TO SHOW ONE MORE
SEMI-ORGANIZED LINE OF SHOWERS CROSSING THE FORECAST AREA AFTER
MIDNIGHT, BETWEEN ROUGHLY 05Z TO 08Z, AND WE HAVE TIMED POPS
ACCORDINGLY FROM WEST TO EAST ACROSS THE FORECAST AREA DURING THE
EARLY MORNING. OTHERWISE, WE HAVE ALSO USED THE LAV/LAMP GUIDANCE
TO CAPTURE THE LATEST TEMPERATURE AND DEWPOINT TRENDS OVER THE
NEXT SEVERAL HOURS.
PREVIOUS DISCUSSION...SHOWERS WILL GRADUALLY DEVELOP AHEAD OF THE
FRONT AND THEN AS WE HEAD INTO TONIGHT, WE SHOULD SEE IT
OVERSPREADING THE AREA. BEST LIFT DOESN`T ARRIVE UNTIL TONIGHT AND
IT SEEMS TO COINCIDE FAIRLY WELL WITH THE LOW LEVEL JET. THIS MAY
ALLOW FOR SOME HEAVIER RAIN TO DEVELOP FOR A SHORT PERIOD OF TIME.
WITH THE STRONG LOW LEVEL WINDS IN PLACE, WE COULD SEE SOME MIXING
DEVELOP, WHICH WOULD BRING SOME DECENT GUSTS TO THE SURFACE.
THE FRONT APPEARS TO BE PRETTY PROGRESSIVE, AND IT MOVES FAIRLY
QUICKLY THROUGH THE REGION. EXPECT US TO DRY OUT FROM WEST TO EAST
WITH ANY LIGHT SHOWERS EXITING THE REGION AND OFFSHORE PRIOR TO DAWN.
AS THE FRONT CROSSES THE REGION, WE WILL SEE WINDS QUICKLY CHANGE
FROM SOUTHWEST TO NORTHWEST.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
THE FRONT EXITS OFFSHORE AND AWAY FROM THE REGION BY EARLY
MORNING AND WITH HIGH PRESSURE BUILDING IN WE SHOULD SEE A QUICK
DRYING OUT OCCUR ACROSS THE AREA. WITH THE WINDS SHIFTING TO THE
NORTHWEST BY MORNING, WE WILL SEE THEM PICK UP QUICKLY AND BECOME
GUSTY THROUGH MUCH OF THE DAY. THE AIRMASS REMAINS ON THE WARM
SIDE BUT IT WILL NOT BE NEARLY AS WARM AS WE HAVE SEEN THE PAST
SEVERAL DAYS. EVEN WITH CLEARING SKIES, WE WILL ONLY SEE MAX TEMPS
RISE INTO THE 50S TO LOWER 60S ACROSS THE REGION. WITH THE WINDS
GUSTING ACROSS THE AREA, IT WILL FEEL A BIT COOLER. STILL A NICE
DECEMBER DAY WITH ABOVE NORMAL TEMPERATURES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
THE LONG TERM PERIOD STARTS OUT WITH A SHORTWAVE RIDGE ALOFT OVER
THE EASTERN US ALONG WITH WEAK HIGH PRESSURE AT THE SURFACE AND A
DRY AIRMASS OVERALL. THE AIRMASS IS ALSO STILL RATHER MILD FOR
DECEMBER...ALTHO NOT RECORD-BREAKING LIKE THE PAST COUPLE OF DAYS.
PLEASANT WEATHER WILL CONTINUE THROUGH WEDNESDAY BUT THEN CLOUDS
INCREASE WED NIGHT AHEAD OF A STRONG UPPER TROF AND ASSOCIATED
COLD FRONT MOVING INTO THE EASTERN US. PRECIP IN THE FORM OF RAIN
OR SHOWERS SHOULD SPREAD ACROSS THE AREA FROM WEST TO EAST
THURSDAY MORNING AND CONTINUE THROUGH THE AFTERNOON WHEN THE BEST
FORCING FOR UVV IS EXPECTED TO OCCUR.
THE COLD FRONT IS FCST TO MOVE ACROSS THE AREA THURSDAY NIGHT AND
WILL USHER IN A SEASONABLY COLD AIR MASS. STRONG LOW-LEVEL COLD
ADVECTION WILL CONTINUE ON FRIDAY BEHIND THE FRONT RESULTING IN
MUCH COOLER TEMPERATURES. THE UPPER LEVEL TROF WILL STILL BE TO
OUR WEST AND THERE APPEARS TO BE CONSIDERABLE SHRTWV ENERGY
ROTATING THRU THE TROF WITH SOME FORCING FOR UVV. MOISTURE AT THAT
TIME MAY BE LIMITED BY WE HAVE CHANCE POPS ACROSS THE AREA FOR
FRIDAY. AS COLDER 850 HPA TEMPS MOVE IN THERE COULD BE SOME SNOW
MIXING IN WITH ANY PRECIP ALTHO SFC TEMPS SHOULD BE TOO WARM FOR
ANY ACCUMULATION.
THE SHORTWAVE IS FCST TO INDUCE LOW PRES ALONG THE OFFSHORE COLD
FRONT ON FRIDAY AND THE WAVE WILL DEEPEN AS IT MOVES NE INTO THE
CANADIAN MARITIMES. CIRC AROUND THE LOW WOULD RESULT IN GUSTY NW
WINDS ON SATURDAY WITH RESULTANT WIND CHILLS IN THE 20S TO LOW
30S. A MODERATING TREND SHOULD DEVELOP FOR SUN AND MONDAY AS SFC
HIGH PRES MOVES OFF THE SE COAST AND WINDS BECOME SWLY OVER THE
MID ATLANTIC.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY, AND SURROUNDING AREAS.
MAINLY MVFR/IFR CONDITIONS ARE EXPECTED THROUGH MUCH OF THE
OVERNIGHT, WITH ADDITIONAL SCATTERED SHOWERS ACROSS THE REGION.
ANOTHER LINE OF MORE ORGANIZED SHOWERS WITH A WIND SHIFT FROM
SOUTHWEST TO WESTERLY IS EXPECTED WITH THE FRONTAL PASSAGE, AND
THIS WILL ROUGHLY OCCUR IN THE 05Z TO 08Z TIMEFRAME FROM WEST TO
EAST ACROSS THE REGION.
A STRONG LOW LEVEL JET WILL CROSS THE REGION TONIGHT. THIS MAY
CAUSE A PERIOD OF LOW LEVEL WIND SHEAR TO OCCUR, MAINLY SPEED
SHEAR FROM KPHL AND TO THE SOUTH AND EAST. THE SURFACE WINDS WILL
REMAIN AROUND 10 TO 12 KNOTS AND WINDS 2000 FEET ABOVE THE SURFACE
MAY APPROACH 48- 52 KNOTS, MAKING SHEAR MARGINAL. WITH THAT SAID,
CONFIDENCE IS NOT HIGH ENOUGH TO INCLUDE IN THE CURRENT TAF.
TUESDAY... BEHIND THE COLD FRONT, WINDS WILL VEER TO THE NORTHWEST
AND BECOME QUITE GUSTY. EXPECT WIND SPEEDS TO BE BETWEEN 15-20
KNOTS, WITH GUSTS UP TO 30 KNOTS THROUGH TUESDAY AFTERNOON. SKIES
ARE EXPECTED TO MOSTLY CLEAR WITH MAINLY VFR CONDITIONS EXPECTED.
OUTLOOK...
TUE NIGHT THROUGH WED NIGHT...VFR CONDS UNDER HIGH PRES. HIGH
CONFIDENCE...EXCEPT CONDS MAY BECOME MVFR LATE WED NIGHT.
THU AND THU NIGHT...MVFR/IFR CIGS AND VSBYS PSBL IN RAIN AND
HEAVIER SHRA. CFP WILL BRING AN ABRUPT WIND SHIFT TO NORTHWEST
WINDS THU NIGHT. HIGH CONFIDENCE
FRI...MAINLY VFR BUT SOME MVFR CONDS PSBL IN SHRA.
SAT...VFR CONDS BUT WITH NW WINDS GUSTING 20-30 KT.
&&
.MARINE...
A SOUTH TO SOUTHWEST FLOW CONTINUES FOR AWHILE TONIGHT, AND GUSTS
TO AROUND 25 KNOTS HAVE BEEN OCCURRING IN THE UPPER DELAWARE BAY.
THIS LOOKS TO CONTINUE WITH EVEN GUSTS TO ABOUT 25 KNOTS THROUGH
ABOUT MIDDAY TUESDAY WITH A WESTERLY FLOW. AS A RESULT, A SMALL
CRAFT ADVISORY HAS BEEN ISSUED FOR THE UPPER DELAWARE BAY THROUGH
18Z TUESDAY.
OTHERWISE, A SOUTH TO SOUTHWEST FLOW CONTINUES ACROSS THE AREA
WATERS LATE THIS EVENING AHEAD OF AN APPROACHING COLD FRONT. AS
THE COLD FRONT GETS CLOSER TO THE REGION, THE GRADIENT WILL
TIGHTEN UP AND WE WILL SEE BOTH SUSTAINED WINDS AND GUSTS
INCREASE. WITH THE SOUTHERLY FLOW BRINGING WARMER AIR OVER THE
COOL WATERS, DO NOT EXPECT WINDS TO ACHIEVE FULL GUST POTENTIAL
UNTIL WE START TO SEE MORE OF A SHIFT TO THE WEST. SEAS WILL
GRADUALLY BUILD IN THE SOUTHERLY FLOW.
THE COLD FRONT WILL CROSS THE REGION TONIGHT AND WE WILL SEE WINDS
QUICKLY GO FROM SOUTH OR SOUTHWEST TO WEST THEN NORTHWEST. WINDS
WILL INCREASE AND WE WILL SEE GUSTS OF 25 TO 30 KNOTS OVER THE
WATERS THROUGH TUESDAY. SOUNDINGS SHOW A SOLID LAYER OF GALE FORCE
GUSTS JUST ABOVE THE SURFACE BUT WITH THE WARM AIR BLOWING OVER THE
COOLER WATERS, WE EXPECT TO SEE DIMINISHED MIXING OCCUR. CAN NOT
COMPLETELY RULE OUT GALE FORCE GUSTS FOR A SHORT PERIOD OF TIME ON
TUESDAY BUT CONFIDENCE IS TOO LOW TO RAISE A GALE WARNING.
OUTLOOK...
TUE NIGHT...GUSTY NW WINDS MAY CONTINUE INTO TUE NIGHT BUT SHOULD
DIMINISH BELOW SCA LEVELS BY WED MORN. THE SCA MAY EVENTUALLY NEED
TO BE EXTENDED A FEW HOURS BEYOND 00Z WED.
WED THROUGH THU...SUB SCA CONDS ARE EXPECTED. HOWEVER SOUTH WINDS
WILL BE INCREASING ON THU AND MAY APPROACH SCA LEVELS LATE THU.
FRI THROUGH SAT...A COLD FRONT PASSAGE THU NIGHT WILL BE FOLLOWED
BY INCREASING NW WINDS. SCA WILL LIKELY BE NEEDED AND WIND COULD
APPROACH GALE FORCE ON SAT.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST TUESDAY FOR ANZ431-450>455.
SMALL CRAFT ADVISORY UNTIL 1 PM EST TUESDAY FOR ANZ430.
&&
$$
SYNOPSIS...AMC
NEAR TERM...KLINE/MEOLA
SHORT TERM...MEOLA
LONG TERM...AMC
AVIATION...AMC/KLINE/MEOLA
MARINE...AMC/GORSE/MEOLA
AREA FORECAST DISCUSSION
NWS MIAMI FL
111 PM EST TUE DEC 15 2015
.AVIATION...
VFR WILL CONTINUE AT ALL TERMINALS THIS AFTERNOON. A FEW SHRA ARE
FORECAST TO DEVELOP, BUT REMAIN WELL INLAND FROM THE TERMINALS.
ONSHORE WINDS OF 5-10 KT WILL PREVAIL. WINDS SLACKEN OVERNIGHT
WITH PATCHY FOG LIKELY DEVELOPING OVER THE INTERIOR AND TOWARDS
THE GULF COAST. WENT WITH NEAR IFR AT KAPF FOR EARLY WED MORNING.
THINKING IS THAT THE FOG WILL REMAIN INLAND FROM THE EAST COAST,
THOUGH WILL HAVE TO WATCH TRENDS AT KTMB. ANY FOG WILL LIFT BY
13-14Z WED WITH VFR PREVAILING THEREAFTER. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 1025 AM EST TUE DEC 15 2015/
UPDATE...
A RIDGE OF HIGH PRESSURE DOMINATES SOUTH FLORIDA...AND IT IS
STRONG. THE MORNING MIAMI SOUNDING SHOWED A VERY WARM THERMAL
PROFILE. IT RECORDED THE WARMEST H5 TEMP FOR THIS DATE AND TIED
FOR THE WARMEST H85 TEMP FOR DEC 15TH. THIS MEANS ANOTHER VERY
WARM AND HUMID DAY FOR SOUTH FLORIDA. GLOBAL AND HI-RES MODELS
THOUGH KEEP HIGHS A COUPLE OF DEGREES BELOW RECORDS EVEN DESPITE
THE VERY WARM THERMAL PROFILE. THIS A RESULT OF SEA BREEZES
DEVELOPING ALONG BOTH COASTS, WHICH LIKELY WILL KEEP MAX TEMPS
DOWN FROM WHAT COULD OCCUR ON AN OFFSHORE FLOW...BUT WILL MONITOR
TRENDS. DEWPOINTS IN THE 70-75F RANGE WILL COMBINE WITH THE WARM
TEMPS TO SEND HEAT INDICES TO NEAR 90F MANY AREAS THIS
AFTERNOON...FEELING NOTHING LIKE DECEMBER!
LOW CLOUDINESS OVER THE WESTERN INTERIOR WILL GRADUALLY LIFT AND
DISSIPATE THROUGH THE REST OF THE MORNING. A FEW SHOWERS ARE
FORECAST TO DEVELOP THIS AFTERNOON OVER THE INTERIOR AS THE SEA
BREEZE MOVE INLAND. THINKING THE HRRR A BIT BULLISH ON SHOWERS BUT
LIKE THE 20-30% POPS FOR THE INTERIOR THIS AFTERNOON, SO NO
SIGNIFICANT CHANGES TO THE FORECAST WILL BE MADE THIS MORNING.
/GREGORIA
PREV DISCUSSION... /ISSUED 651 AM EST TUE DEC 15 2015/
AVIATION...
PATCHY FOG WILL CONTINUE AT KAPF AND KTMB FOR ABOUT THE NEXT HOUR
BEFORE IMPROVING. OTHERWISE, VFR WILL PREVAIL ACROSS THE AREA.
WINDS WILL BECOME SE AT 5-10 KT, EXCEPT BECOMING SW 5-10 KT AT
KAPF. WINDS WILL AGAIN BECOME LIGHT TONIGHT. PATCHY FOG WILL
AGAIN BE POSSSIBLE LATE TONIGHT AT KAPF AND KTMB. /GREGORIA
PREV DISCUSSION... /ISSUED 434 AM EST TUE DEC 15 2015/
LIKELIHOOD OF FOG MAIN FORECAST CONCERN NEXT COUPLE OF DAYS
ACROSS INTERIOR...
VERY MUCH WELCOME SEASONAL COOL TEMPERATURES IN STORE FOR
SOUTH FLORIDA THIS WEEKEND BEHIND COLD FRONT MOVING THROUGH THE
REGION LATE IN THE WEEK...
DISCUSSION...
AMPLIFIED AND PROGRESSIVE PATTERN TAKING SHAPE ACROSS THE CONUS
THIS WEEK WILL BRING CHANGES TO SOUTH FLORIDA THIS WEEKEND. BUT
FIRST...SHORT TERM CHALLENGE IS THE LIKELIHOOD OF SOME FOG
FORMATION EARLY THIS MORNING, WEDNESDAY MORNING, AND AGAIN
THURSDAY MORNING ...PARTICULARLY ACROSS INTERIOR SECTIONS IN AREAS
ALONG AND NORTH OF ALLIGATOR ALLEY WEST TO NAPLES AND NORTH TO
AROUND THE LAKE OKEECHOBEE REGION INLAND FROM EAST COAST METRO
AREAS. LOW LEVEL MOIST SOUTHERLY FLOW ALONG WITH DEPTH OF SFC
LAYER AND WIND PROFILES WITHIN THAT LAYER AND JUST ABOVE FAVOR
BEST CHANCES FOR FOG WITH PATCHES OF REDUCED VISIBILITY TO LESS
THAN 1 MILE EARLY THIS MORNING AND WEDNESDAY MORNING WITH STILL A
LINGERING CHANCE THURSDAY MORNING. THIS IS SUPPORTED BY SREF
PROBABILITIES OF VISIBILITIES LESS THAN 1 MILE WHICH ARE AROUND
50% FOR PORTIONS OF THE NW INTERIOR THIS MORNING AND WEDNESDAY
MORNING AND AROUND 40% FOR THURSDAY MORNING. SO WILL PLACE PATCHY
FOG AND/OR COMBINATION OF AREAS OF FOG WITH PATCHY FOG IN GRIDS
FOR THOSE PERIODS WITH EMPHASIS IN INTERIOR AND PARTICULARLY NW
INTERIOR WEST OF LAKE OKE.
THE SURFACE FRONT ASSOCIATED WITH THE STORM SYSTEM LIFTING INTO THE
GREAT LAKES AT THIS TIME WILL STALL OUT NORTH OF THE FORECAST AREA
NEXT FEW DAYS...KEEPING THE AREA IN A WARM AND MOIST ENVIRONMENT.
PASSING SHOWERS WILL BE POSSIBLE AT JUST ABOUT ANY LOCATION THE
NEXT FEW DAYS...WITH BEST CHANCES OVER LAND ASSOCIATED WITH DIURNAL
HEATING. AS WAS OBSERVED ON MONDAY...THERE IS SOME SIGNAL IN THE
SHORT RANGE HIGH RESOLUTION MODELS OF THE ATLANTIC, LAKE OKE, AND
GULF SEA BREEZES HELPING SOME SHOWER DEVELOPMENT MIDDAY TODAY AND
POPS WILL BE HIGHEST IN THE INTERIOR. IN FACT, HIGH RES SHORT
RANGE GUIDANCE SIGNALS BEST CHANCES OF MAINLY DAYTIME SHOWERS ARE
ACROSS INTERIOR AND EAST COAST TODAY AS THAT IS WHEN INSTABILITY
IS BEST OVER NEXT FEW DAYS. THEN CHANCES GO DOWN FOR WED AND
THURSDAY BEFORE THEY INCREASE WITH FRONTAL PASSAGE ON FRIDAY.
INSTABILITY HOWEVER WILL REMAIN LIMITED FOR ANY THUNDERSTORMS NEXT
FEW DAYS. THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS WITH
FRONT ON FRIDAY.
VERY ENERGETIC FLOW CONTINUES OVER THE PACIFIC INTO THE WESTERN
US. ANOTHER SHORTWAVE TROUGH IS DIGGING INTO THE LONGWAVE TROUGH
OVER THE CENTRAL US. BEHIND THIS...HEIGHTS ARE RISING OVER THE
PACIFIC NORTHWEST AND WESTERN CANADA...DISLODGING SOME SEASONABLY
COLD AIR. THIS COLD FRONT WILL HAVE MORE MOMENTUM AND MEDIUM RANGE
MODELS CONTINUE TO BE IN VERY GOOD AGREEMENT THE FRONT WILL PASS
THROUGH THE FORECAST AREA ON OR ABOUT FRIDAY AFTERNOON/EVENING.
CONFIDENCE ON THIS SCENARIO CONTINUES TO INCREASE AS MODELS HAVE
BEEN CONSISTENT AND THIS CONTINUES TO BE THE CONSENSUS AMONG
ENSEMBLE SYSTEMS.
THE FRONTAL PASSAGE WILL BE ASSOCIATED WITH A MUCH DRIER AND
SOMEWHAT COOLER AIR MASS. TEMPERATURES WILL BE AROUND NORMAL FOR
THIS TIME OF THE YEAR FOR MORNING LOWS AND EVEN A FEW BELOW NORMAL
FOR DAYTIME HIGHS OVER THE WEEKEND. A GREAT WEEKEND IN STORE FOR
SOUTH FLORIDA. MORNING LOW TEMPERATURES IN THE LOWER 50S POSSIBLE
SATURDAY AND SUNDAY IN THE FAR NORTHWEST PART OF THE AREA. THE LOW
LEVEL FLOW WILL QUICKLY COME BACK AROUND TO THE EAST EARLY NEXT
WEEK...WITH GRADUAL RETURN TO WARMER AND MORE HUMID CONDITIONS IN
STORE NEXT WEEK.
ALSO THERE IS STILL A CHANCE RECORD HIGH MINIMUM TEMPERATURES WILL
BE APPROACHED OR EVEN TIED OR BROKEN NEXT FEW MORNINGS BEFORE
FRONTAL PASSAGE ON FRIDAY. ALTHOUGH LESS LIKELY HIGH TEMPS WILL BE
CLOSE TO RECORD LEVELS NEXT COUPLE OF DAYS TOO.
AVIATION...
LIGHT SELY BREEZES WILL PERSIST THROUGH NEXT 24 HOURS EXCEPT
LIGHT AND VARIABLE WINDS LIKELY OVERNIGHT AT ALL SITES EXCEPT
IMMEDIATE COASTAL SITES SUCH AS FLL WHERE LIGHT SELY ONSHORE FLOW
WILL LIKELY PREVAIL OVERNIGHT. MAIN CONCERN EARLY THIS MORNING AND
AGAIN TONIGHT WILL BE AT APF WITH PERIODS OF IFR CIG/VIS
CONDITIONS LIKELY ASSOCIATED WITH FOG DEVELOPMENT. SIMILAR
CONCERNS BUT TO SOMEWHAT LESSER EXTENT FOR TMB ALSO.
MARINE...
A LIGHT TO GENTLE BREEZE AND SMOOTH TO SLIGHT SEA STATE WILL BE
THE RULE FOR BOTH ATLANTIC AND GULF COASTAL WATERS THROUGH
WEDNESDAY. SOME INCREASE IN WINDS THURSDAY AS A FRONT APPROACHES.
BEHIND THE FRONT LATE FRIDAY INTO SATURDAY...AN INCREASE IN BOTH
WINDS AND SEA STATE CAN BE EXPECTED WITH DETERIORATING MARINE
CONDITIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 72 85 74 / 20 10 20 20
FORT LAUDERDALE 84 73 83 74 / 20 10 10 20
MIAMI 84 73 85 74 / 20 20 10 10
NAPLES 84 69 85 71 / 10 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
1025 AM EST TUE DEC 15 2015
.UPDATE...
A RIDGE OF HIGH PRESSURE DOMINATES SOUTH FLORIDA...AND IT IS
STRONG. THE MORNING MIAMI SOUNDING SHOWED A VERY WARM THERMAL
PROFILE. IT RECORDED THE WARMEST H5 TEMP FOR THIS DATE AND TIED
FOR THE WARMEST H85 TEMP FOR DEC 15TH. THIS MEANS ANOTHER VERY
WARM AND HUMID DAY FOR SOUTH FLORIDA. GLOBAL AND HI-RES MODELS
THOUGH KEEP HIGHS A COUPLE OF DEGREES BELOW RECORDS EVEN DESPITE
THE VERY WARM THERMAL PROFILE. THIS A RESULT OF SEA BREEZES
DEVELOPING ALONG BOTH COASTS, WHICH LIKELY WILL KEEP MAX TEMPS
DOWN FROM WHAT COULD OCCUR ON AN OFFSHORE FLOW...BUT WILL MONITOR
TRENDS. DEWPOINTS IN THE 70-75F RANGE WILL COMBINE WITH THE WARM
TEMPS TO SEND HEAT INDICES TO NEAR 90F MANY AREAS THIS
AFTERNOON...FEELING NOTHING LIKE DECEMBER!
LOW CLOUDINESS OVER THE WESTERN INTERIOR WILL GRADUALLY LIFT AND
DISSIPATE THROUGH THE REST OF THE MORNING. A FEW SHOWERS ARE
FORECAST TO DEVELOP THIS AFTERNOON OVER THE INTERIOR AS THE SEA
BREEZE MOVE INLAND. THINKING THE HRRR A BIT BULLISH ON SHOWERS BUT
LIKE THE 20-30% POPS FOR THE INTERIOR THIS AFTERNOON, SO NO
SIGNIFICANT CHANGES TO THE FORECAST WILL BE MADE THIS MORNING.
/GREGORIA
&&
.PREV DISCUSSION... /ISSUED 651 AM EST TUE DEC 15 2015/
AVIATION...
PATCHY FOG WILL CONTINUE AT KAPF AND KTMB FOR ABOUT THE NEXT HOUR
BEFORE IMPROVING. OTHERWISE, VFR WILL PREVAIL ACROSS THE AREA.
WINDS WILL BECOME SE AT 5-10 KT, EXCEPT BECOMING SW 5-10 KT AT
KAPF. WINDS WILL AGAIN BECOME LIGHT TONIGHT. PATCHY FOG WILL
AGAIN BE POSSSIBLE LATE TONIGHT AT KAPF AND KTMB. /GREGORIA
PREV DISCUSSION... /ISSUED 434 AM EST TUE DEC 15 2015/
.LIKELIHOOD OF FOG MAIN FORECAST CONCERN NEXT COUPLE OF DAYS
ACROSS INTERIOR...
.VERY MUCH WELCOME SEASONAL COOL TEMPERATURES IN STORE FOR
SOUTH FLORIDA THIS WEEKEND BEHIND COLD FRONT MOVING THROUGH THE
REGION LATE IN THE WEEK...
DISCUSSION...
AMPLIFIED AND PROGRESSIVE PATTERN TAKING SHAPE ACROSS THE CONUS
THIS WEEK WILL BRING CHANGES TO SOUTH FLORIDA THIS WEEKEND. BUT
FIRST...SHORT TERM CHALLENGE IS THE LIKELIHOOD OF SOME FOG
FORMATION EARLY THIS MORNING, WEDNESDAY MORNING, AND AGAIN
THURSDAY MORNING ...PARTICULARLY ACROSS INTERIOR SECTIONS IN AREAS
ALONG AND NORTH OF ALLIGATOR ALLEY WEST TO NAPLES AND NORTH TO
AROUND THE LAKE OKEECHOBEE REGION INLAND FROM EAST COAST METRO
AREAS. LOW LEVEL MOIST SOUTHERLY FLOW ALONG WITH DEPTH OF SFC
LAYER AND WIND PROFILES WITHIN THAT LAYER AND JUST ABOVE FAVOR
BEST CHANCES FOR FOG WITH PATCHES OF REDUCED VISIBILITY TO LESS
THAN 1 MILE EARLY THIS MORNING AND WEDNESDAY MORNING WITH STILL A
LINGERING CHANCE THURSDAY MORNING. THIS IS SUPPORTED BY SREF
PROBABILITIES OF VISIBILITIES LESS THAN 1 MILE WHICH ARE AROUND
50% FOR PORTIONS OF THE NW INTERIOR THIS MORNING AND WEDNESDAY
MORNING AND AROUND 40% FOR THURSDAY MORNING. SO WILL PLACE PATCHY
FOG AND/OR COMBINATION OF AREAS OF FOG WITH PATCHY FOG IN GRIDS
FOR THOSE PERIODS WITH EMPHASIS IN INTERIOR AND PARTICULARLY NW
INTERIOR WEST OF LAKE OKE.
THE SURFACE FRONT ASSOCIATED WITH THE STORM SYSTEM LIFTING INTO THE
GREAT LAKES AT THIS TIME WILL STALL OUT NORTH OF THE FORECAST AREA
NEXT FEW DAYS...KEEPING THE AREA IN A WARM AND MOIST ENVIRONMENT.
PASSING SHOWERS WILL BE POSSIBLE AT JUST ABOUT ANY LOCATION THE
NEXT FEW DAYS...WITH BEST CHANCES OVER LAND ASSOCIATED WITH DIURNAL
HEATING. AS WAS OBSERVED ON MONDAY...THERE IS SOME SIGNAL IN THE
SHORT RANGE HIGH RESOLUTION MODELS OF THE ATLANTIC, LAKE OKE, AND
GULF SEA BREEZES HELPING SOME SHOWER DEVELOPMENT MIDDAY TODAY AND
POPS WILL BE HIGHEST IN THE INTERIOR. IN FACT, HIGH RES SHORT
RANGE GUIDANCE SIGNALS BEST CHANCES OF MAINLY DAYTIME SHOWERS ARE
ACROSS INTERIOR AND EAST COAST TODAY AS THAT IS WHEN INSTABILITY
IS BEST OVER NEXT FEW DAYS. THEN CHANCES GO DOWN FOR WED AND
THURSDAY BEFORE THEY INCREASE WITH FRONTAL PASSAGE ON FRIDAY.
INSTABILITY HOWEVER WILL REMAIN LIMITED FOR ANY THUNDERSTORMS NEXT
FEW DAYS. THERE WILL BE A SLIGHT CHANCE OF THUNDERSTORMS WITH
FRONT ON FRIDAY.
VERY ENERGETIC FLOW CONTINUES OVER THE PACIFIC INTO THE WESTERN
US. ANOTHER SHORTWAVE TROUGH IS DIGGING INTO THE LONGWAVE TROUGH
OVER THE CENTRAL US. BEHIND THIS...HEIGHTS ARE RISING OVER THE
PACIFIC NORTHWEST AND WESTERN CANADA...DISLODGING SOME SEASONABLY
COLD AIR. THIS COLD FRONT WILL HAVE MORE MOMENTUM AND MEDIUM RANGE
MODELS CONTINUE TO BE IN VERY GOOD AGREEMENT THE FRONT WILL PASS
THROUGH THE FORECAST AREA ON OR ABOUT FRIDAY AFTERNOON/EVENING.
CONFIDENCE ON THIS SCENARIO CONTINUES TO INCREASE AS MODELS HAVE
BEEN CONSISTENT AND THIS CONTINUES TO BE THE CONSENSUS AMONG
ENSEMBLE SYSTEMS.
THE FRONTAL PASSAGE WILL BE ASSOCIATED WITH A MUCH DRIER AND
SOMEWHAT COOLER AIR MASS. TEMPERATURES WILL BE AROUND NORMAL FOR
THIS TIME OF THE YEAR FOR MORNING LOWS AND EVEN A FEW BELOW NORMAL
FOR DAYTIME HIGHS OVER THE WEEKEND. A GREAT WEEKEND IN STORE FOR
SOUTH FLORIDA. MORNING LOW TEMPERATURES IN THE LOWER 50S POSSIBLE
SATURDAY AND SUNDAY IN THE FAR NORTHWEST PART OF THE AREA. THE LOW
LEVEL FLOW WILL QUICKLY COME BACK AROUND TO THE EAST EARLY NEXT
WEEK...WITH GRADUAL RETURN TO WARMER AND MORE HUMID CONDITIONS IN
STORE NEXT WEEK.
ALSO THERE IS STILL A CHANCE RECORD HIGH MINIMUM TEMPERATURES WILL
BE APPROACHED OR EVEN TIED OR BROKEN NEXT FEW MORNINGS BEFORE
FRONTAL PASSAGE ON FRIDAY. ALTHOUGH LESS LIKELY HIGH TEMPS WILL BE
CLOSE TO RECORD LEVELS NEXT COUPLE OF DAYS TOO.
AVIATION...
LIGHT SELY BREEZES WILL PERSIST THROUGH NEXT 24 HOURS EXCEPT
LIGHT AND VARIABLE WINDS LIKELY OVERNIGHT AT ALL SITES EXCEPT
IMMEDIATE COASTAL SITES SUCH AS FLL WHERE LIGHT SELY ONSHORE FLOW
WILL LIKELY PREVAIL OVERNIGHT. MAIN CONCERN EARLY THIS MORNING AND
AGAIN TONIGHT WILL BE AT APF WITH PERIODS OF IFR CIG/VIS
CONDITIONS LIKELY ASSOCIATED WITH FOG DEVELOPMENT. SIMILAR
CONCERNS BUT TO SOMEWHAT LESSER EXTENT FOR TMB ALSO.
MARINE...
A LIGHT TO GENTLE BREEZE AND SMOOTH TO SLIGHT SEA STATE WILL BE
THE RULE FOR BOTH ATLANTIC AND GULF COASTAL WATERS THROUGH
WEDNESDAY. SOME INCREASE IN WINDS THURSDAY AS A FRONT APPROACHES.
BEHIND THE FRONT LATE FRIDAY INTO SATURDAY...AN INCREASE IN BOTH
WINDS AND SEA STATE CAN BE EXPECTED WITH DETERIORATING MARINE
CONDITIONS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 84 72 85 74 / 20 10 20 20
FORT LAUDERDALE 84 73 83 74 / 20 10 10 20
MIAMI 84 73 85 74 / 20 20 10 10
NAPLES 84 69 85 71 / 10 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1015 AM EST TUE DEC 15 2015
.DISCUSSION...
WIDESPREAD FOG THIS MRNG HAS LIFTED ACRS MOST OF THE AREA...THOUGH
LOW LVL STRATUS LINGERS OVER MUCH OF THE INTERIOR AREA. THESE CLOUDS
ARE EXPECTED TO BURN OFF THRU MIDDAY AS SFC HEATING ERODES A RATHER
SHARP SFC INVERSION.
FRONTAL BNDRY HAS ADVANCED TO THE FL BIG BEND/CAROLINA COAST...BUT
IS FACING A STEEP UPHILL BATTLE TO ADVANCE ANY FURTHER AS ITS PARENT
LOW IS ALREADY CENTERED OVER ERN CANADA AND WILL RACE ACRS THE
CANADIAN MARITIMES THRU THE DAY. AS IT DOES...IT WILL ABANDON THE
SRN PORTION OF ITS FRONT...LEAVING IT TO ITS OWN FORWARD MOMENTUM AS
IT PLOWS INTO THE WRN FLANK OF A DEEP HIGH PRES RIDGE OVER THE SW
ATLC/SE GOMEX.
MRNG RAOBS SHOW A SATURATED H100-H70 LYR AT KJAX WITH LYR PWAT
VALUES ARND 1.9"...DECREASING TO 1.3"-1.4" OVER CENTRAL FL...THEN
INCREASING INTO S FL TO BTWN 1.6"-1.7". H100-H70 MEAN RH OVER
CENTRAL/SOUTH FL IS NOT PARTICULARLY HIGH...AVERAGING ONLY 60-70PCT
AT BEST. MOISTURE WITHIN THE IMMEDIATE VCNTY OF THE FRONTAL BNDRY
INCREASES TO AOA 90PCT...WHICH IS IN LINE WITH THE KJAX RAOB.
HOWEVER...GIVEN THE DEEP SW FLOW THAT PRESIDES OVER FL...IT WILL BE
DIFFICULT FOR THIS MOISTURE TO WORK ITS WAY ANY FURTHER S THAN IT
ALREADY HAS.
NEITHER THE HRRR NOR THE 3SM WRF MODEL INDICATES MUCH IN THE WAY OF
PRECIP THRU THE AFTN. DIFFICULT TO ARGUE THESE SOLUTIONS GIVEN THE
LATEST RADAR TRENDS ACRS THE STATE...AS WELL AS THE GENERAL LACK OF
ANY MID LVL VORTICITY/UPR LVL DIVERGENCE OUTSIDE OF THE VCNTY OF THE
FRONT. MID LVL ANALYSIS SHOWS H50 TEMPS HAVE COOLED TO -7C/-8C ALONG
AND N OF THE I-4 CORRIDOR...RESULTING IN H70-H50 LAPSE RATES BTWN
5.5-6.0C/KM. MRNG FCST PACKAGE LOOKS GOOD WITH HIGHEST POPS (30PCT)
ACRS THIS AREA...DECREASING TO 20PCT S OF I-4. S/SW FLOW ONCE
AGAIN WILL SEND AFTN TEMPS INTO THE U70S/M80S ACRS CENTRAL FL.
&&
.AVIATION...THRU 16/12Z
SFC WNDS: THRU 15/16Z...S/SW 6-9KTS. BTWN 15/16Z-15/18Z...S OF KMLB-
KGIF BCMG S/SE 7-10KTS. BTWN 16/00Z-16/03Z...BCMG VRBL AOB 3KTS ALL
SITES.
VSBYS/WX/CIGS:
THRU 15/16Z...WDSPRD IFR/AREAS LIFR CIGS...AREAS IFR/LCL LIFR VSBYS
IN BR/FG...SLGT CHC SHRAS S OF KFPR. BTWN 15/16Z-16/03Z...N OF KISM-
KEVB CHC MVFR SHRAS...S OF KISM-KEVB SLGT CHC MVFR SHRAS. BTWN
16/03Z-16/06Z...N OF KISM-KMLB AREAS OF MVFR/LCL IFR VSBYS IN BR.
AFT 16/06Z...WDSPRD IFR/AREAS LIFR CIGS...N OF OF KISM-KMLB
WIDESPREAD IFR/AREAS LIFR VSBYS IN BR/FG...S OF KISM-KMLB AREAS
IFR/LCL LIFR VSBYS IN IN BR/FG.
&&
.MARINE...
WEAK FRONTAL TROF STALLED OVER THE FL BIG BEND/CAROLINA COAST HAS
WEAKENED THE LCL PGRAD SUFFICIENTLY TO DROP SFC/BNDRY LYR SWRLY WINDS
BLO 10KTS...AS EVIDENCED BY LCL DATA BUOY/SFC OB NETWORK. SEAS RUNNING
2-3FT...LARGELY IN A LONG PD ERLY SWELL. FAVORABLE BOATING CONDITIONS
TODAY AS THE RIDGE AXIS OVER S FL DRIFTS NWD AND FORCES THE FRONT BACK
TO THE N AS A WEAK WARM FRONT. LIGHT TO GENTLE S/SW BREEZE WILL BACK
TO THE S/SE THRU SUNSET...CONTG OVERNIGHT. SEAS GENERALLY 2-3FT...UP
TO 4FT IN THE GULF STREAM THRU SUNSET.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...CRISTALDI
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
327 AM EST TUE DEC 15 2015
.DISCUSSION...
...FOGGY IN PLACES THIS MORNING...
...WARM AGAIN ESPECIALLY ORLANDO SOUTHWARD...
TODAY-TONIGHT...FRONT MAKING SLOW PROGRESS ACROSS APALACHEE BAY
AS EVIDENT BY WEAK CONVECTIVE LINE AHEAD OF IT. HRRR MODEL
ENDEAVORS TO BRING ISOLATED SHOWERS TO N LAKE AND INLAND VOLUSIA
COUNTIES...AND PERHAPS EVEN BY SUNRISE. MORE INTERESTING IS THE
CONCERN FOR DENSE FOG AS WCFL HAS ALREADY SUCCUMBED AND TREND
SHOULD BE FOR CONTINUED NE ENCROACHMENT ACROSS THE KISSIMMEE RIVER
INTO OKEECHOBEE AND OSCEOLA COUNTIES...TO ENGULF PARTS OF LAKE...
ORANGE...AND SEMINOLE COUNTIES TOO. AREAS OF FOG WILL REDUCE
VISIBILITIES TO BELOW A MILE IN SEVERAL PLACES...WHICH WILL BE
SLOW TO BURN OFF AFTER SUNRISE. PATCHY DENSE FOG ELSEWHERE. WILL
HOLD OFF ON DENSE FOG ADVISORY FOR NOW...BUT MAY BECOME NECESSARY
BEFORE MORNING COMMUTE...ESPECIALLY FOR FL TURNPIKE JUST WEST OF
FORT PIERCE NW THRU ORLANDO TOWARD LEESBURG. SATELLITE FOG PRODUCT
SHOWS INTERIOR SECTIONS FILLING IN.
IT WILL BE WARMER THAN NORMAL AGAIN TODAY FOR PLACES SOUTH OF
ORLANDO TO LAKE OKEECHOBEE COURTESY OF S/SW WIND FLOW...TEMPS INTO
THE LOW/MID 80S. THE FRONT WILL STALL ACROSS THE N PENINSULA...
OFFERING CHANCE POPS N AND W OF INTERSTATE 4. SLIGHT POPS
ELSEWHERE.
WED...VERY WARM WEATHER CONTINUES ON WEDNESDAY WITH SOUTHERLY LOW
LVL FLOW SOUTH OF A SLOWLY LIFTING WARM FRONT ACROSS N FL. EXPECT
STRATUS AND AREAS OF FOG NEAR SUNRISE WHICH WILL BREAK UP INTO MID
MORNING. MOISTURE LEVELS WILL BE SUFFICIENT FOR AN ISOLATED SHOWER
CHANCE ACROSS SRN AREAS AND A CHANCE OF SHOWERS ACROSS THE NRN HALF
OF THE FORECAST AREA WITH SOME DEEPER MOISTURE IN THE LOW LEVELS
CLOSER TO THE LIFTING WARM FRONT. HIGHS WILL REACH THE MID 80S
INTERIOR TO LOWER 80S IMMEDIATE COAST.
WED NIGHT...LIGHT SOUTHERLY FLOW AND CLEARING SKIES IN THE MID
LEVELS ALONG WITH DWPTS IN THE UPR 60S TO AROUND 70 SHOULD ALLOW
AREAS OF LOW STRATUS AND FOG TO REDEVELOP AFTER MIDNIGHT AGAIN. WILL
FORECAST AREAS OF FOG FOR THE INTERIOR AND N CSTL SECTIONS AND
PATCHY FOG FOR S CSTL AREAS. LOWS IN THE UPPER 60S TO 70/LWR 70S S
CSTL AREAS.
THU...SFC LOW PRESSURE ACROSS N GA EARLY WILL RIDE QUICKLY NE AND
PULL A COLD FRONT FROM THE FL PANHANDLE TWD THE BIG BEND IN THE
AFTERNOON. GFS INDICATES PREFRONTAL MOISTENING MAINLY IN THE LATE
AFTERNOON SHOULD SUPPORT A LOW SHOWER CHANCE INTO THE EARLY TO MID
AFTERNOON AND A ISOLATED TO SCATTERED SHOWERS TOWARD EARLY
EVENING IN THE WARM SECTOR. WILL KEEP POPS IN THE 20-30 PCT RANGE.
HIGHS WILL REACH NEAR RECORD VALUES ONCE AGAIN INTO THE MID 80S
ACROSS MUCH OF THE AREA.
THU NIGHT...GFS/ECMWF ARE IN GOOD AGREEMENT WITH COLD FRONT TIMING
INTO NRN SECTIONS LATE THU NIGHT WITH A BAND OF PRE-FRONTAL
CONVECTION EXPECTED TO MOVE INTO FAR NRN AREAS IN THE EVENING AND
INTO CENTRAL SECTIONS THROUGH THE NIGHT. WILL CONTINUE THUNDER
CHANCES FOR MAINLY NRN AREAS IN THE EVENING AND DOWN TO OSCEOLA AND
BREVARD COUNTIES OVERNIGHT. WIND FIELDS WILL BE INCREASING WITH H8
WINDS TO 25 KNOTS/ H7 WINDS TO 35 KNOTS AND H5 WINDS TO 45-50 KNOTS
ACROSS THE NRN HALF OF THE FORECAST AREA. COULD BE A FEW HEAVIER
SHOWERS OR STORMS WITH GUSTY WINDS ACROSS NRN SECTIONS. POPS WILL BE
IN THE SCATTERED/LIKELY RANGE NORTH TO ISOLATED TO SCATTERED ACROSS
OKEECHOBEE AND THE TREASURE COAST. LOWS MAINLY IN THE 60S...EXCEPT
LOWER 70S S CSTL.
FRIDAY...THE FRONT WILL SWEEP SOUTH THROUGH E CENTRAL FL ON FRIDAY
WITH WINDS BECOMING NNW BEHIND THE FRONT IN THE AFTERNOON. ONGOING
SHOWERS AND ISOLATED STORMS IN THE EARLY MORNING WILL TRANSITION
SOUTH OF ORLANDO BY LATE AFTERNOON AS THE FRONT MOVES SOUTH. LARGE
TEMP GRADIENT EXPECTED WITH MORNING HIGHS EXPECTED ACROSS THE NORTH
IN THE UPPER 60S TO LOWER 70S WITH UPPER 70S/LOWER 80S ACROSS FAR
SRN SECTIONS BEFORE THE FRONT MOVES THROUGH AND DROPS TEMPERATURES.
EXPECT SOME HEAVIER SHOWERS OR ISOLATED STORMS WITH GUSTY WINDS BUT
NOT EXPECTING SEVERE WEATHER AS CONVECTION MOVES SOUTH OF THE AREA
INTO THE EVENING HOURS.
FRI NIGHT-SAT...SFC HIGH PRESSURE WILL BUILD FROM THE WRN GULF
TOWARD THE SE STATES SATURDAY. EVENING CONVECTION ACROSS FAR SRN
AREAS FRIDAY EVENING WILL MOVE WELL SOUTH OF THE AREA THROUGH THE
NIGHT WITH CLEARING SKIES AND FALLING TEMPERATURES. EXPECT SOME OF
THE COLDEST AIR OF THE WINTER SEASON WITH LOWS DROPPING INTO THE 40S
ACROSS THE NRN AREAS AND THE INTERIOR AND 50S FROM BREVARD SOUTH
ALONG THE COAST. MOSTLY SUNNY AND MUCH COOLER CONDITIONS ARE
EXPECTED SATURDAY WITH HIGHS INTO THE LOWER 60S NRN AREAS TO MID 60
CENTRAL AND UPPER 60S SOUTH.
SAT NIGHT...THE FLOW WILL START TO VEER SAT NIGHT BUT STILL EXPECT A
NORTHERLY COMPONENT INLAND TO KEEP TEMPS FROM BEING MODERATED MUCH
FROM THE ATLC. LOWS WILL DROP INTO THE MID-UPPER 40S ACROSS THE NRN
INTERIOR AND 50S CLOSER TO THE COAST.
SUN-TUE...SFC HIGH NEAR ERN NC SUNDAY WILL TRANSITION EASTWARD INTO
THE ATLC FOR EARLY NEXT WEEK ALLOWING FOR A RETURN TO ONSHORE FLOW
AND TEMPERATURES RISING BACK ABOVE NORMAL FOR MONDAY AND TUESDAY OF
NEXT WEEK. HIGHS SUNDAY AROUND 70 WILL REBOUND INTO THE UPPER
70S/AROUND 80 MON-TUE. WILL KEEP SUNDAY-MONDAY DRY AND INTRODUCE A
LOW SHOWER CHANCE ON TUESDAY WITH ISOLATED ONSHORE MOVING SHOWERS.
&&
.AVIATION...BTWN 09Z-14Z...INTERIOR SITES IFR CIGS WITH AREAS LIFR
CIGS/VSBYS IN BR/FG...COASTAL SITES MOSTLY VFR BUT TEMPO IFR WITH
PTCHY CIGS/VSBYS IN BR. AFT 15/14Z...CHC MVFR SHRAS N OF KISM-
KTIX...SLGT CHC S OF KISM-KTIX.
&&
.MARINE...
TODAY-TONIGHT...CONTINUED IMPROVEMENT TO BOATING CONDITIONS AS WINDS
FURTHER SLACKEN AND SEAS DAMPEN. FRONT STALLS JUST NORTH OF THE
LOCAL WATERS AND OF LITTLE CONSEQUENCE EXCEPT FOR SLIGHTLY BETTER
CHANCES FOR VICINITY SHOWERS N OF PORT CANAVERAL. GENTLE S/SW
WINDS 10 KNOTS OR LESS WITH DECREASING SEAS 4 FEET OR
LESS...EXCEPT 5 FEET WELL OFFSHORE N OF SEBASTIAN INLET THIS
MORNING.
SE WINDS WILL INCREASE SOME WED AFTERNOON TO NEAR 10 KNOTS AND
VEER TO SOUTHERLY AND INCREASE TO 15 KNOTS WED NIGHT AND 15-20
KNOTS OFFSHORE THU. STRONG COLD FRONT WILL MOVE ACROSS THE WATERS
LATE THU NIGHT INTO FRIDAY WITH GUSTY NORTHERLY WINDS EXPECTED TO
RAISE WINDS AND SEAS TO ADVISORY LEVELS FRIDAY NIGHT INTO SATURDAY
BEHIND THE FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 78 67 82 68 / 30 30 30 20
MCO 81 68 85 68 / 20 20 30 10
MLB 82 69 82 70 / 20 20 20 10
VRB 83 68 83 70 / 20 20 20 10
LEE 79 68 83 68 / 30 30 30 10
SFB 80 68 84 68 / 30 20 30 10
ORL 81 69 85 69 / 30 20 30 10
FPR 82 68 84 70 / 20 20 20 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...DWS
LONG TERM....MRV
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1019 PM EST WED DEC 16 2015
.SYNOPSIS...
INCREASING MOISTURE TONIGHT INTO THURSDAY AHEAD OF A COLD FRONT.
NUMEROUS SHOWERS AND A FEW THUNDERSTORMS EXPECTED THURSDAY
AFTERNOON AS THE FRONT APPROACHES. THE STRONG COLD FRONT WILL MOVE
THROUGH THE AREA THURSDAY NIGHT. COOLER AND DRY CONDITIONS WILL
SPREAD ACROSS THE AREA FRIDAY ON GUSTY WEST WINDS. A COOL AND DRY
AIR MASS WILL SETTLE OVER THE AREA THROUGH THE WEEKEND...WITH
WARMING EXPECTED NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM THURSDAY MORNING/...
SURFACE HIGH PRESSURE RETREATING OFFSHORE THIS EVENING.
A COLD FRONT WILL PUSH ACROSS THE OHIO/TENNESSEE VALLEY WITH
SHORTWAVE ENERGY MOVING INTO THE LOWER MISSISSIPPI VALLEY INDUCING
CYCLOGENESIS ALONG THE GULF COAST. MODELS BRING STRONG MOISTURE
ADVECTION AND ISENTROPIC LIFT INTO THE FORECAST AREA OVERNIGHT
AHEAD OF THE APPROACHING FRONT. CLOUDY SKIES EXTENDING FROM GA
INTO THE WESTERN HALF OF SOUTH CAROLINA WILL OVERSPREAD THE REGION
BY MIDNIGHT. PWAT VALUES TO INCREASE TO OVER 1.5 INCHES BY EARLY
MORNING.
SHOWERS CROSSING THE CSRA WILL CONTINUE SPREADING NORTHEAST MAINLY
AFFECTING THE WESTERN HALF OF THE FORECAST AREA THROUGH MIDNIGHT
THEN SPREADING EAST DURING THE EARLY MORNING HOURS. THE HIGH
RESOLUTIONS MODELS ARE INDICATING AREAS OF DENSE FOG DEVELOPING
ACROSS THE CENTRAL AND EASTERN MIDLANDS AS A WARM FRONT OVER
SOUTHERN GA THIS EVENING LIFTS NORTHWARD INTO THE FORECAST AREA
AFTER MIDNIGHT.
WILL CONTINUE WITH A POP GRADIENT OVERNIGHT...RANGING FROM
CATEGORICAL WEST TO CHANCE EAST. CLOUDS OVERNIGHT WILL HELP TO
MODERATE LOWS. TEMPERATURES OVERNIGHT EXPECTED IN THE MIDDLE TO
UPPER 50S.
&&
.SHORT TERM /7 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
A BROAD BUT AMPLIFIED UPPER TROUGH IN THE MIDWEST WILL BE MOVING
EAST AS DEEP LOW PRESSURE MOVES INTO SOUTHERN CANADA. A STRONG
SURFACE COLD FRONT WILL BE IN THE APPALACHIAN MOUNTAINS AND GULF
COAST AREA EARLY THURSDAY. A WARM FRONT WILL SET UP ACROSS THE
NORTH MIDLANDS SO MOST OF THE AREA SHOULD BE IN WARM SECTOR.
INCREASING MOISTURE/ISENTROPIC LIFT EARLY THURSDAY ALTHOUGH DEEPER
MOISTURE/STRONGER LIFT LIKELY IN THE UPSTATE REGION CLOSER TO
UPPER LEVEL JET DYNAMICS AND AREA OF WEAK LOW PRESSURE TRACKING
NORTHEAST. BASED ON LATEST HIGH RESOLUTION MODELS BACKED OFF ON
POPS EARLY IN THE DAY WITH FOCUS MAINLY WEST. AS FRONT APPROACHES
FROM THE WEST IN THE LATE AFTERNOON...LIFT EXPECTED TO INCREASE
AND INSTABILITY POSSIBLY MODERATE. STRONGEST INSTABILITY LIKELY IN
THE EAST. PRECIPITABLE WATER STILL EXPECTED TO BE ABOVE
NORMAL...NEAR 1.75 INCHES. MODEL QPF IS A LITTLE LOWER THAN
PREVIOUS RUNS...ALTHOUGH SREF STILL NEAR 1 INCH. FORECAST
CATEGORICAL POPS LATE AFTERNOON THROUGH EARLY EVENING. WITH 50KT
LOW LEVEL JET THERE IS POTENTIAL FOR A FEW SEVERE THUNDERSTORMS.
MILD CONDITIONS AHEAD OF FRONT MOS CONSENSUS ACCEPTED. FRONT
MOVING THROUGH AREA BETWEEN 05Z AND 09Z. SHOWERS MOVING EAST OF
AREA BY MORNING SO CUT POPS BACK LATE. COLD ADVECTION
FRIDAY...EXPECT BREEZY CONDITIONS. SECONDARY FRONT/UPPER TROUGH
MOVING THROUGH IN THE AFTERNOON ENHANCING COLD ADVECTION BUT
DOWNSLOPE SHOULD OFFSET IT SOMEWHAT. SO TEMPERATURE FORECAST
UPPER 50S TO MID 60S FRIDAY. DIMINISHING WIND FRIDAY NIGHT AND AIR
MASS COLD. 850MB TEMPERATURES -2C TO -5C. GUIDANCE TEMPERATURE
ACCEPTED NEAR OR BELOW FREEZING.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
COOL AND DRY AIR MASS IN PLACE THROUGH THE WEEKEND. TEMPERATURES
LIKELY AT OR BELOW NORMAL. MODERATING TEMPERATURES AND A RETURN
TO ACTIVE WEATHER EXPECTED EARLY NEXT WEEK.
THE COLDEST TEMPERATURES WILL OCCUR OVER THE WEEKEND AS 1030MB
SURFACE HIGH BUILDS IN AND SETTLES OVER THE FORECAST AREA. VERY
DRY AIR AND CLEAR SKIES WILL LEAD TO EXCELLENT RADIATIONAL COOLING
CONDITIONS AT NIGHT AND EXPECT LOWS TO FALL INTO THE UPPER 20S AND
LOWER 30S FRIDAY AND SATURDAY NIGHT...WHILE HIGHS ON SATURDAY WILL
BE IN THE LOWER TO MID 50S.
SURFACE HIGH PRESSURE WILL SHIFT OFFSHORE ON SUNDAY IN RESPONSE TO A
QUICK MOVING LOW AMPLITUDE SHORTWAVE MOVING INTO THE OHIO/TENNESSEE
VALLEY WITH A WEAK RETURN SOUTHERLY FLOW ALLOWING TEMPERATURES TO
MODERATE WARMER FOR SUNDAY. CHANCES FOR RAIN INCREASE EARLY NEXT
WEEK AS YET ANOTHER DEEP TROUGH SETS UP ACROSS THE MIDDLE PART OF
THE COUNTRY WITH BACKING SOUTHWESTERLY UPPER FLOW OVER THE
SOUTHEASTERN STATES. TEMPERATURES WILL CONTINUE TO WARM BACK ABOVE
NORMAL LATE IN THE PERIOD WITH SOUTHERLY FLOW DEVELOPING.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS DETERIORATING TO MVFR/IFR RESTRICTIONS TONIGHT
AND CONTINUING THROUGH MOST OF THE TAF PERIOD.
RAIN SHOWERS MOVING NORTH FROM CENTRAL GEORGIA AND THE CSRA WILL
CONTINUE TO MOVE INTO THE CENTRAL AND WESTERN MIDLANDS TONIGHT.
CURRENT TRENDS AND LATEST HRRR GUIDANCE KEEP THIS INITIAL AREA OF
SHOWERS JUST WEST OF OGB. EXPECT VFR CONDITIONS TO DETERIORATE
INTO MVFR/IFR BY LATE TONIGHT INTO THURSDAY MORNING. RAIN HAS BEEN
MODERATE AT TIMES RESULTING IN TEMPORARY VISIBILITY RESTRICTIONS.
MODELS CONTINUE TO SHIFT THE MAJORITY OF THE RAINFALL INTO THE
UPSTATE THROUGH THE MORNING HOURS. ALL TAF SITES SHOULD ENCOUNTER
PERIODS OF LIGHT RAIN...BR...ALONG WITH IFR/MVFR CEILINGS THROUGH
THE DAY THURSDAY AS RAIN CHANCES INCREASE TO NEAR 100 PERCENT BY
18Z. MODEL GUIDANCE SHOWS IMPROVEMENT TO VFR AT OGB BY THURSDAY
AFTERNOON...BUT CONFIDENCE IS TOO LOW TO INCLUDE ATTM. WINDS WILL
GENERALLY BE LIGHT TONIGHT AND OUT OF THE E/SE AND WILL INCREASE
TO 10 TO 15 KNOTS WITH GUSTS UP TO 20 KNOTS OUT OF THE S/SW AFTER
14Z THURSDAY.
EXTENDED AVIATION OUTLOOK...RAIN WITH MVFR TO IFR RESTRICTIONS
THURSDAY NIGHT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
914 PM EST WED DEC 16 2015
.SYNOPSIS...
INCREASING MOISTURE TONIGHT INTO THURSDAY AHEAD OF A COLD FRONT.
NUMEROUS SHOWERS AND A FEW THUNDERSTORMS EXPECTED THURSDAY
AFTERNOON AS THE FRONT APPROACHES. THE STRONG COLD FRONT WILL MOVE
THROUGH THE AREA THURSDAY NIGHT. COOLER AND DRY CONDITIONS WILL
SPREAD ACROSS THE AREA FRIDAY ON GUSTY WEST WINDS. A COOL AND DRY
AIR MASS WILL SETTLE OVER THE AREA THROUGH THE WEEKEND...WITH
WARMING EXPECTED NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM THURSDAY MORNING/...
SURFACE HIGH PRESSURE RETREATING OFFSHORE THIS EVENING.
A COLD FRONT WILL PUSH ACROSS THE OHIO/TENNESSEE VALLEY WITH
SHORTWAVE ENERGY MOVING INTO THE LOWER MISSISSIPPI VALLEY INDUCING
CYCLOGENESIS ALONG THE GULF COAST. MODELS BRING STRONG MOISTURE
ADVECTION AND ISENTROPIC LIFT INTO THE FORECAST AREA OVERNIGHT
AHEAD OF THE APPROACHING FRONT. CLOUDY SKIES EXTENDING FROM GA
INTO THE WESTERN HALF OF SOUTH CAROLINA WILL OVERSPREAD THE REGION
BY MIDNIGHT. PWAT VALUES TO INCREASE TO OVER 1.5 INCHES BY EARLY
MORNING.
SHOWERS CROSSING THE CSRA WILL CONTINUE SPREADING NORTHEAST MAINLY
AFFECTING THE WESTERN HALF OF THE FORECAST AREA THROUGH MIDNIGHT
...THEN SPREADING EAST DURING THE EARLY MORNING HOURS. THE HIGH
RESOLUTIONS MODELS ARE INDICATING AREAS OF DENSE FOG DEVELOPING
ACROSS THE CENTRAL AND EASTERN MIDLANDS AS A WARM FRONT OVER
SOUTHERN GA THIS EVENING LIFTS NORTHWARD INTO THE FORECAST AREA
AFTER MIDNIGHT.
WILL CONTINUE WITH A POP GRADIENT OVERNIGHT...RANGING FROM
CATEGORICAL WEST TO CHANCE EAST. CLOUDS OVERNIGHT WILL HELP TO
MODERATE LOWS. TEMPERATURES OVERNIGHT EXPECTED IN THE MIDDLE TO
UPPER 50S.
&&
.SHORT TERM /7 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
A BROAD BUT AMPLIFIED UPPER TROUGH IN THE MIDWEST WILL BE MOVING
EAST AS DEEP LOW PRESSURE MOVES INTO SOUTHERN CANADA. A STRONG
SURFACE COLD FRONT WILL BE IN THE APPALACHIAN MOUNTAINS AND GULF
COAST AREA EARLY THURSDAY. A WARM FRONT WILL SET UP ACROSS THE
NORTH MIDLANDS SO MOST OF THE AREA SHOULD BE IN WARM SECTOR.
INCREASING MOISTURE/ISENTROPIC LIFT EARLY THURSDAY ALTHOUGH DEEPER
MOISTURE/STRONGER LIFT LIKELY IN THE UPSTATE REGION CLOSER TO
UPPER LEVEL JET DYNAMICS AND AREA OF WEAK LOW PRESSURE TRACKING
NORTHEAST. BASED ON LATEST HIGH RESOLUTION MODELS BACKED OFF ON
POPS EARLY IN THE DAY WITH FOCUS MAINLY WEST. AS FRONT APPROACHES
FROM THE WEST IN THE LATE AFTERNOON...LIFT EXPECTED TO INCREASE
AND INSTABILITY POSSIBLY MODERATE. STRONGEST INSTABILITY LIKELY IN
THE EAST. PRECIPITABLE WATER STILL EXPECTED TO BE ABOVE
NORMAL...NEAR 1.75 INCHES. MODEL QPF IS A LITTLE LOWER THAN
PREVIOUS RUNS...ALTHOUGH SREF STILL NEAR 1 INCH. FORECAST
CATEGORICAL POPS LATE AFTERNOON THROUGH EARLY EVENING. WITH 50KT
LOW LEVEL JET THERE IS POTENTIAL FOR A FEW SEVERE THUNDERSTORMS.
MILD CONDITIONS AHEAD OF FRONT MOS CONSENSUS ACCEPTED. FRONT
MOVING THROUGH AREA BETWEEN 05Z AND 09Z. SHOWERS MOVING EAST OF
AREA BY MORNING SO CUT POPS BACK LATE. COLD ADVECTION
FRIDAY...EXPECT BREEZY CONDITIONS. SECONDARY FRONT/UPPER TROUGH
MOVING THROUGH IN THE AFTERNOON ENHANCING COLD ADVECTION BUT
DOWNSLOPE SHOULD OFFSET IT SOMEWHAT. SO TEMPERATURE FORECAST
UPPER 50S TO MID 60S FRIDAY. DIMINISHING WIND FRIDAY NIGHT AND AIR
MASS COLD. 850MB TEMPERATURES -2C TO -5C. GUIDANCE TEMPERATURE
ACCEPTED NEAR OR BELOW FREEZING.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
COOL AND DRY AIR MASS IN PLACE THROUGH THE WEEKEND. TEMPERATURES
LIKELY AT OR BELOW NORMAL. MODERATING TEMPERATURES AND A RETURN
TO ACTIVE WEATHER EXPECTED EARLY NEXT WEEK.
THE COLDEST TEMPERATURES WILL OCCUR OVER THE WEEKEND AS 1030MB
SURFACE HIGH BUILDS IN AND SETTLES OVER THE FORECAST AREA. VERY
DRY AIR AND CLEAR SKIES WILL LEAD TO EXCELLENT RADIATIONAL COOLING
CONDITIONS AT NIGHT AND EXPECT LOWS TO FALL INTO THE UPPER 20S AND
LOWER 30S FRIDAY AND SATURDAY NIGHT...WHILE HIGHS ON SATURDAY WILL
BE IN THE LOWER TO MID 50S.
SURFACE HIGH PRESSURE WILL SHIFT OFFSHORE ON SUNDAY IN RESPONSE TO A
QUICK MOVING LOW AMPLITUDE SHORTWAVE MOVING INTO THE OHIO/TENNESSEE
VALLEY WITH A WEAK RETURN SOUTHERLY FLOW ALLOWING TEMPERATURES TO
MODERATE WARMER FOR SUNDAY. CHANCES FOR RAIN INCREASE EARLY NEXT
WEEK AS YET ANOTHER DEEP TROUGH SETS UP ACROSS THE MIDDLE PART OF
THE COUNTRY WITH BACKING SOUTHWESTERLY UPPER FLOW OVER THE
SOUTHEASTERN STATES. TEMPERATURES WILL CONTINUE TO WARM BACK ABOVE
NORMAL LATE IN THE PERIOD WITH SOUTHERLY FLOW DEVELOPING.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS THIS EVENING WITH MVFR/IFR RESTRICTIONS DEVELOPING
TONIGHT AND CONTINUING THROUGH MOST OF THE TAF PERIOD.
RAIN SHOWERS OVER CENTRAL GA WILL CONTINUE SHIFTING NORTH THIS
EVENING...IMPACTING AGS/DNL BY AROUND 01Z AND CAE/CUB BY 04Z.
CURRENT TRENDS AND LATEST RAP GUIDANCE KEEP THIS INITIAL AREA OF
SHOWERS WEST OF OGB. EXPECT VFR CONDITIONS TO DETERIORATE INTO
MVFR/IFR BY LATE TONIGHT INTO THURSDAY MORNING. SHOWER COVERAGE
TONIGHT WILL BE SCATTERED OVER THE CSRA AND ISOLATED TO
SCATTERED OVER THE CENTRAL MIDLANDS. AFTER THIS INITIAL AREA OF
SHOWERS...MODELS KEEP MAJORITY OF THE RAINFALL IN THE UPSTATE
THROUGH THE MORNING HOURS. ALL TAF SITES SHOULD ENCOUNTER PERIODS
OF LIGHT RAIN...BR...ALONG WITH IFR/MVFR CEILINGS THROUGH THE DAY
THURSDAY AS RAIN CHANCES INCREASE TO NEAR 100 PERCENT BY 18Z.
MODEL GUIDANCE SHOWS IMPROVEMENT TO VFR AT OGB BY LATE THURSDAY
AFTERNOON...BUT CONFIDENCE IS TOO LOW TO INCLUDE ATTM. WINDS WILL
GENERALLY BE LIGHT TONIGHT AND OUT OF THE E/SE AND WILL INCREASE
TO 10 TO 15 KNOTS WITH GUSTS UP TO 20 KNOTS OUT OF THE S/SW AFTER
14Z THURSDAY.
EXTENDED AVIATION OUTLOOK...RAIN WITH MVFR TO IFR RESTRICTIONS
THURSDAY NIGHT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
643 PM EST WED DEC 16 2015
.SYNOPSIS...
INCREASING MOISTURE TONIGHT INTO THURSDAY AHEAD OF A COLD FRONT.
NUMEROUS SHOWERS AND A FEW THUNDERSTORMS EXPECTED THURSDAY
AFTERNOON AS THE FRONT APPROACHES. THE STRONG COLD FRONT WILL MOVE
THROUGH THE AREA THURSDAY NIGHT. COOLER AND DRY CONDITIONS WILL
SPREAD ACROSS THE AREA FRIDAY ON GUSTY WEST WINDS. A COOL AND DRY
AIR MASS WILL SETTLE OVER THE AREA THROUGH THE WEEKEND...WITH
WARMING EXPECTED NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
SURFACE HIGH PRESSURE RETREATING OFFSHORE THIS EVENING.
A COLD FRONT WILL PUSH ACROSS THE OHIO/TENNESSEE VALLEY WITH
SHORTWAVE ENERGY MOVING INTO THE LOWER MISSISSIPPI VALLEY INDUCING
CYCLOGENESIS ALONG THE GULF COAST. MODELS STILL BRING STRONG
MOISTURE ADVECTION AND ISENTROPIC LIFT INTO THE FORECAST AREA LATE
TONIGHT AHEAD OF THE APPROACHING FRONT. THIS WILL SPREAD CLOUDS
TO THE REGION TONIGHT. PWAT VALUES INCREASE FROM A HALF AN INCH
THIS EVENING...TO OVER 1.5 INCHES BY EARLY MORNING.
SHOWERS ACROSS EAST CENTRAL GA EARLY THIS EVENING RAPIDLY
SPREADING NORTHEAST. COULD SEE A FEW SHOWERS ACROSS THE
PIEDMONT/WESTERN MIDLANDS AND UPPER SAVANNAH RIVER AREA THIS
EVENING. STILL EXPECT THE BEST CHANCES FOR RAINFALL AFTER
MIDNIGHT. WILL CONTINUE WITH A POP GRADIENT FROM WEST TO EAST
OVERNIGHT. CLOUDS OVERNIGHT WILL HELP TO MODERATE LOWS.
TEMPERATURES OVERNIGHT EXPECTED IN THE MIDDLE TO UPPER 50S.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
A BROAD BUT AMPLIFIED UPPER TROUGH IN THE MIDWEST WILL BE MOVING
EAST AS DEEP LOW PRESSURE MOVES INTO SOUTHERN CANADA. A STRONG
SURFACE COLD FRONT WILL BE IN THE APPALACHIAN MOUNTAINS AND GULF
COAST AREA EARLY THURSDAY. A WARM FRONT WILL SET UP ACROSS THE
NORTH MIDLANDS SO MOST OF THE AREA SHOULD BE IN WARM SECTOR.
INCREASING MOISTURE/ISENTROPIC LIFT EARLY THURSDAY ALTHOUGH DEEPER
MOISTURE/STRONGER LIFT LIKELY IN THE UPSTATE REGION CLOSER TO
UPPER LEVEL JET DYNAMICS AND AREA OF WEAK LOW PRESSURE TRACKING
NORTHEAST. BASED ON LATEST HIGH RESOLUTION MODELS BACKED OFF ON
POPS EARLY IN THE DAY WITH FOCUS MAINLY WEST. AS FRONT APPROACHES
FROM THE WEST IN THE LATE AFTERNOON...LIFT EXPECTED TO INCREASE
AND INSTABILITY POSSIBLY MODERATE. STRONGEST INSTABILITY LIKELY IN
THE EAST. PRECIPITABLE WATER STILL EXPECTED TO BE ABOVE
NORMAL...NEAR 1.75 INCHES. MODEL QPF IS A LITTLE LOWER THAN
PREVIOUS RUNS...ALTHOUGH SREF STILL NEAR 1 INCH. FORECAST
CATEGORICAL POPS LATE AFTERNOON THROUGH EARLY EVENING. WITH 50KT
LOW LEVEL JET THERE IS POTENTIAL FOR A FEW SEVERE THUNDERSTORMS.
MILD CONDITIONS AHEAD OF FRONT MOS CONSENSUS ACCEPTED. FRONT
MOVING THROUGH AREA BETWEEN 05Z AND 09Z. SHOWERS MOVING EAST OF
AREA BY MORNING SO CUT POPS BACK LATE. COLD ADVECTION
FRIDAY...EXPECT BREEZY CONDITIONS. SECONDARY FRONT/UPPER TROUGH
MOVING THROUGH IN THE AFTERNOON ENHANCING COLD ADVECTION BUT
DOWNSLOPE SHOULD OFFSET IT SOMEWHAT. SO TEMPERATURE FORECAST
UPPER 50S TO MID 60S FRIDAY. DIMINISHING WIND FRIDAY NIGHT AND AIR
MASS COLD. 850MB TEMPERATURES -2C TO -5C. GUIDANCE TEMPERATURE
ACCEPTED NEAR OR BELOW FREEZING.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
COOL AND DRY AIR MASS IN PLACE THROUGH THE WEEKEND. TEMPERATURES
LIKELY AT OR BELOW NORMAL. MODERATING TEMPERATURES AND A RETURN
TO ACTIVE WEATHER EXPECTED EARLY NEXT WEEK.
THE COLDEST TEMPERATURES WILL OCCUR OVER THE WEEKEND AS 1030MB
SURFACE HIGH BUILDS IN AND SETTLES OVER THE FORECAST AREA. VERY
DRY AIR AND CLEAR SKIES WILL LEAD TO EXCELLENT RADIATIONAL COOLING
CONDITIONS AT NIGHT AND EXPECT LOWS TO FALL INTO THE UPPER 20S AND
LOWER 30S FRIDAY AND SATURDAY NIGHT...WHILE HIGHS ON SATURDAY WILL
BE IN THE LOWER TO MID 50S.
SURFACE HIGH PRESSURE WILL SHIFT OFFSHORE ON SUNDAY IN RESPONSE TO A
QUICK MOVING LOW AMPLITUDE SHORTWAVE MOVING INTO THE OHIO/TENNESSEE
VALLEY WITH A WEAK RETURN SOUTHERLY FLOW ALLOWING TEMPERATURES TO
MODERATE WARMER FOR SUNDAY. CHANCES FOR RAIN INCREASE EARLY NEXT
WEEK AS YET ANOTHER DEEP TROUGH SETS UP ACROSS THE MIDDLE PART OF
THE COUNTRY WITH BACKING SOUTHWESTERLY UPPER FLOW OVER THE
SOUTHEASTERN STATES. TEMPERATURES WILL CONTINUE TO WARM BACK ABOVE
NORMAL LATE IN THE PERIOD WITH SOUTHERLY FLOW DEVELOPING.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS THIS EVENING WITH MVFR/IFR RESTRICTIONS DEVELOPING
TONIGHT AND CONTINUING THROUGH MOST OF THE TAF PERIOD.
RAIN SHOWERS OVER CENTRAL GA WILL CONTINUE SHIFTING NORTH THIS
EVENING...IMPACTING AGS/DNL BY AROUND 01Z AND CAE/CUB BY 04Z.
CURRENT TRENDS AND LATEST RAP GUIDANCE KEEP THIS INITIAL AREA OF
SHOWERS WEST OF OGB. EXPECT VFR CONDITIONS TO DETERIORATE INTO
MVFR/IFR BY LATE TONIGHT INTO THURSDAY MORNING. SHOWER COVERAGE
TONIGHT WILL BE SCATTERED OVER THE CSRA AND ISOLATED TO
SCATTERED OVER THE CENTRAL MIDLANDS. AFTER THIS INITIAL AREA OF
SHOWERS...MODELS KEEP MAJORITY OF THE RAINFALL IN THE UPSTATE
THROUGH THE MORNING HOURS. ALL TAF SITES SHOULD ENCOUNTER PERIODS
OF LIGHT RAIN...BR...ALONG WITH IFR/MVFR CEILINGS THROUGH THE DAY
THURSDAY AS RAIN CHANCES INCREASE TO NEAR 100 PERCENT BY 18Z.
MODEL GUIDANCE SHOWS IMPROVEMENT TO VFR AT OGB BY LATE THURSDAY
AFTERNOON...BUT CONFIDENCE IS TOO LOW TO INCLUDE ATTM. WINDS WILL
GENERALLY BE LIGHT TONIGHT AND OUT OF THE E/SE AND WILL INCREASE
TO 10 TO 15 KNOTS WITH GUSTS UP TO 20 KNOTS OUT OF THE S/SW AFTER
14Z THURSDAY.
EXTENDED AVIATION OUTLOOK...RAIN WITH MVFR TO IFR RESTRICTIONS
THURSDAY NIGHT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1137 PM CST MON DEC 14 2015
.UPDATE...
ISSUED AT 835 PM CST MON DEC 14 2015
The storm system that affected the area yesterday and last night
with rain and strong winds has shifted well to our northeast this
evening. In its wake, gusty westerly winds continue, although we
have seen a gradual decrease in the gusts over the past few
hours. In addition, a large area of clouds extended from central
Nebraska through the Dakotas south through southern Missouri and
Illinois. The area was not showing much movement in any direction
this evening which sheds some doubt to whether we are going to see
much, if any, sun on Tuesday.
High resolution forecast soundings continue to suggest the moisture
in the lower levels of the atmosphere will be trapped under a
subsidence inversion through most of the day. Have kept the clouds
in a bit longer for Tuesday and gradually decreased the cloud
cover across the far south as a weak ridge of high pressure slips
through the area during the day. Have made some minor tweaks to
the early evening temp trends and winds. Should have the update
out by 9 pm.
&&
.SHORT TERM...(Tonight)
ISSUED AT 252 PM CST MON DEC 14 2015
Main forecast challenge in the short term will be the extent of
lingering scattered showers and the spread of drizzle this evening,
and the extent of cloud cover overnight.
The latest surface analysis at 20Z (2 pm cst) indicated an area of
low pressure in northeast IA with a trough extending southwest into
extreme northwest MO. A short wave trough axis extended from an
upper low in northeast IL into west central IL. This was producing
scattered showers in western and central IL this afternoon. These
showers are expected to shift into NE-east central IL early this
evening as the trough axis rotates through the area. Lingering low
level moisture and weak lift should produce some patchy drizzle
during the evening mainly north of a Macomb-Bloomington-Danville
line.
The short range models are in a bit of a disagreement regarding the
amount of any breaks/clearing in the cloud cover overnight. The NAM,
SREF and HRRR indicate that the clouds shouldn`t start breaking up
until later Tuesday morning, while the GFS and RAP are trying to
clear things up around or just before daybreak. Prefer the slower
solutions of keeping the cloud cover over the forecast area into the
morning. Even if the quicker clearing models verify, the saturated
ground and lighter surface winds should allow for stratus and fog to
develop quickly. With the clouds and gradually decreasing westerly
winds, temperatures overnight will only drop slowly into the 36-40
degree range.
.LONG TERM...(Tuesday through Monday)
ISSUED AT 252 PM CST MON DEC 14 2015
After a dry period tomorrow, another weather system is forecast to
move out of the southern Rockies and northeast across the plains and
into the western Great Lakes region. A cold front associated with
this system will slide across the CWA on Wednesday. Ahead of the
front, tomorrow into tomorrow night, limited low level moisture will
be advected northward into the area. Based on this and limited
dynamics, showers will be possible late tomorrow night through
Wednesday, across the CWA. By Wed evening, the front will have
pushed east of the area and the pcpn will have ended, leaving Wed
night and Thur dry.
Temps will remain mild/above normal through Wed, but then fall to
around normal for Thursday, behind this brief system. Model guidance
looks good through the period.
The remainder of the week and into the weekend will be dry as a
large mid level trough tracks across the US. This trough and
associated sfc high pressure area will bring dry weather and colder
temps. Northwest flow will be temporary for Sat and then transition
back to southwest flow for Sunday and Monday. The southwest flow
will allow southerly winds to return on the sfc, bringing above
normal temps back to the area for Sun and Mon. Along with the warmer
temps, pcpn will return for Sunday night and Mon as another weather
system moves toward and through the area.
Temps will be around or just below normal for Fri and Sat, but then
with southerly winds returning, temps will return to above normal
levels for Sun and Mon.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1125 PM CST MON DEC 14 2015
A large area of mostly MVFR cigs was located over the Midwest
late this evening and is expected to continue into at least
Tuesday afternoon. A weak trof/wind shift line was pushing
across the area late this evening and has been responsible
for producing areas of very light rain/drizzle. That weather
system will track off to our east during the early morning
hours with the MVFR and possibly some occasional IFR cigs
into the morning hours.
With the expansive cloud cover and winds, which are forecast
to hold up a bit longer than expected...will pull back on any
significant lowering of vsbys in fog by morning. Forecast
soundings off the NAM not offering much if any hope of seeing
any significant break in the clouds thru tomorrow afternoon and
evening as low level moisture will remain trapped below an
inversion located around 2500 feet.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Smith
SHORT TERM...Miller
LONG TERM...Auten
AVIATION...Smith
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1135 PM CST MON DEC 14 2015
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Tuesday)
Issued at 329 PM CST MON DEC 14 2015
Upper ridge building in between the old upper system nearing the
Great Lakes and the next deep system developing over the Central
Rockies. Surface pressure rises rather strong just to the northeast,
though considerable falls occurring in eastern Colorado. Northwest
winds decreasing in eastern Kansas, with east winds already
developing in western portions of the state. Stratus, rather thin in
spots, was making only slow progress east on latest satellite loop
with local dewpoint depressions in the 3-10F range.
Main concerns into Tuesday are at the very low levels, unfortunately
where model skill is at its lowest. The next system crosses the
Rockies tonight with surface low entering Kansas. Winds will be
quite light between these systems much of the evening though pick up
toward dawn. With a very wet ground and wet boundary layer, a
favorable setup for radiational fog is in place...if clearing can
occur. So far, guidance has shown very poor skill in handling the
very slow clearing and where it is and is not occurring. Even 19 and
20Z RAP and 15Z SREF data is quite poor in its initial few hours of
progs. Skies could easily remain rather cloudy for especially
northern areas through the night, but think at least enough patches
of clearing are possible for some fog formation. Have kept any
mention limited to the late evening through 12Z as winds/mixing
increase late in the night. Guidance that is more pessimistic with
the stratus suggests some light drizzle could also occur, but the
thin nature of the cloud and little if any lift in it should keep it
from being notable, and temps/ground temps largely warm enough to
keep slick road issues at bay if it were to form. Have kept Tuesday
rather warm given temps in south central Kansas in the low-mid 50s
today. Moisture in the mid and upper levels is rather hard to come
by with the system this far southeast, but will keep a small PoP in
the far northwest nearer the better moisture.
.LONG TERM...(Tuesday Night through Monday)
Issued at 329 PM CST MON DEC 14 2015
Dry cold front moves through the forecast area Tuesday night, as
the next upper low moves across Nebraska and to the north
northeast dragging the front behind. Additional waves moving
through this upper trof keep the Central Plains in the colder air
through Friday. Highs drop to the upper 30s to near 40, with lows
falling into the 20s. Still on track to warm up a bit for the
weekend as upper ridge moves across the state and highs rise back
into the 40s and 50s. Next chance for rain starts Monday but wave
is low amplitude and part of a larger upper system that approaches
the Central Plains later in the week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1135 PM CST MON DEC 14 2015
MVFR cigs along with IFR cigs are expected to continue at the
terminals through 18Z then gradually transition to VFR by 21Z-22Z.
Deepening low pressure will cause winds to increase from the east
around 12 kts by 12Z then gradually increase to around 15 kts with
gusts to 24 kts by 18Z with winds gradually veering to the
southeast and then to the south by 00Z. Winds decrease to around
10 kts shortly after 00Z Wed.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...KP
LONG TERM...67
AVIATION...53
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1058 PM EST WED DEC 16 2015
.UPDATE...
ISSUED AT 1058 PM EST WED DEC 16 2015
FRESHENED UP THE HOURLY TEMPERATURES...DEW POINTS...AND POPS
ACCORDING TO THE LATEST TRENDS IN OBSERVATIONS. RAIN SHOWERS HAVE
EXPANDED IN AREAL COVERAGE AND CONTINUE TO ADVANCE TO THE
NORTHEAST. SOME EASTERN VALLEY TEMPERATURES ARE STILL IN THE
UPPER 40S...BUT THIS SHOULD CHANGE IN THE NEXT HOUR OR SO...AS
THE THICKER CLOUD COVER AND PRECIPITATION HELP TO MIX OUT THE
COOLER AIR. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 722 PM EST WED DEC 16 2015
ONLY LIGHT RETURNS HAVE MADE IT INTO OUR AREA THUS FAR THIS
EVENING...WITH THE LOW LEVEL DRY AIR IN PLACE ACROSS EASTERN
KENTUCKY KEEPING THE SHOWER ACTIVITY AT BAY. CLOUD THINNESS IN
THE EAST AND THE LOW DEW POINTS HAVE ALLOWED FOR A QUICK DROP IN
THE SHELTERED VALLEYS...WITH SOME UPPER 40 DEGREE READINGS
CURRENTLY BEING REPORTED. HAVE ADJUSTED THE TEMPERATURES
ACCORDINGLY...WITH A NICE REBOUND EXPECTED IN THE NEXT FEW HOURS
AS THICKER CLOUD COVER MOVES IN. THE LATEST HRRR LINES UP FAIRLY
WELL WITH THE CURRENT RADAR MOSAIC. THERE IS A NICE AREA OF
SHOWERS MOVING IN ACROSS WESTERN TENNESSEE...WHICH WILL BE MAKING
IT INTO OUR SOUTHWEST COUNTIES BETWEEN 9 AND 10 PM. HAVE ADJUSTED
THE POP TIMING A BIT TO CAPTURE THESE TRENDS. JUST BLENDED BACK
INTO THE EXISTING FORECAST THEREAFTER...WHICH REMAINS ON TRACK
FOR WIDESPREAD SHOWERS TO OVERTAKE THE REST OF EASTERN KENTUCKY
THROUGH THE OVERNIGHT HOURS. UPDATES WILL BE OUT SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 315 PM EST WED DEC 16 2015
AS OF MID AFTERNOON A MID LEVEL RIDGE EXTENDED FROM THE CARIBBEAN
NORTH AND NORTHWEST TOWARD THE JAMES BAY REGION WHILE ANOTHER
RIDGE WAS OVER PARTS OF THE EASTERN PACIFIC. IN BETWEEN...A RATHER
BROAD ENCOMPASSED MUCH OF THE ROCKIES AND CENTRAL AND NORTHERN
PLAINS. AN UPPER LEVEL LOW MOVING THROUGH THIS TROUGH IS LOCATED
OVER THE UPPER MS VALLEY WITH A TRAILING SHORTWAVE TROUGH INTO THE
MS VALLEY REGION WHILE ANOTHER SHORTWAVE TROUGH IS UPSTREAM OVER
THE SOUTHERN ROCKIES. YET ANOTHER SHORTWAVE OF NOTE IS DROPPING
THROUGH THE NORTHERN ROCKIES. AT THE SFC...AN AREA OF LOW PRESSURE
IS OVER THE UPPER MS VALLEY REGION WITH A WARM FRONT EXTENDING
INTO THE MID OH VALLEY REGION AND A COLD FRONT TRAILING SOUTH
THROUGH THE MS VALLEY. SHOWERS ARE CURRENTLY OCCURRING ALONG AND
IN ADVANCE OF THIS FRONT OVER WESTERN AND MIDDLE TN AND PARTS OF
CENTRAL KY AS WELL AS SOUTH INTO MS. IN ADVANCE OF THE COLD
FRONT...TEMPERATURES HAVE WARMED AND DRIER AIR HAS MIXED DOWN AT
BRIEFLY WITH TEMPERATURES HAVING REACHED THE 70 AT JKL...AND SOME
OF THE KY MESONET SITES ACROSS THE SOUTHEAST. THE RECORD HIGH HAS
ALREADY BEEN BROKEN AT JKL SO FAR THIS AFTERNOON.
THE TROUGH OVER THE PLAINS AND ROCKIES WILL MOVE INTO THE CENTRAL
AND EASTERN CONUS THROUGH THE PERIOD. THE INITIAL SHORTWAVE
TROUGH AXIS AND THE COLD FRONT WILL APPROACH THE AREA THIS EVENING
INTO THE OVERNIGHT HOURS AND AS THE NEXT UPSTREAM SHORTWAVE NOW OF
THE SOUTHERN ROCKIES MOVES INTO THE SOUTHERN PLAINS AND THE MS
VALLEY REGION...A WAVE OF LOW PRESSURE WILL DEVELOP ALONG THE
BOUNDARY AND MOVE ACROSS THE SOUTHEASTERN STATES. AS THIS
OCCURS...COVERAGE OF SHOWERS SHOULD INCREASE SIGNIFICANTLY AND
WITH THIS TRACKING TO THE SOUTHEAST OF THE AREA...THE HEAVIEST
RAINFALL SHOULD OCCUR CLOSER TO THE VA AND TN BORDERS. GIVEN THE
CURRENT LOWER DEW POINTS ACROSS THAT REGION...HAVE OPTED TO CUT
BACK ON OVERNIGHT QPF ACROSS THE FAR SOUTHEAST PART OF THE AREA.
THE SECOND SHORTWAVE TROUGH AXIS SHOULD CROSS THE AREA ON THU
AFTERNOON WHILE THE SHORTWAVE THAT IS NOW OVER THE NORTHERN
ROCKIES WILL DROP INTO THE CENTRAL PLAINS AND THEN INTO THE MS
VALLEY AND OH VALLEY LATE IN THE PERIOD. BEHIND THE COLD
FRONT...COLD AIR ADVECTION IS ANTICIPATED FOR THU INTO THU NIGHT
AND HAVE OPTED TO GO CLOSER TO A BLEND OF SUPERBLEND AND MOS
GUIDANCE RATHER THAN A CLIMATOLOGICALLY BASED TEMPERATURE CURVE.
LAPSE RATES MAY STEEPEN SUFFICIENTLY ENOUGH FOR SOME FLURRIES BY
LATE IN THE PERIOD...AND TEMPERATURES SHOULD REACH OR FALL BELOW
FREEZING IN WIDESPREAD FASHION ON THU NIGHT FOR THE FIRST TIME IN
ABOUT A WEEK. THE HEART OF THIS COLD AIRMASS THOUGH WILL HOLD OFF
UNTIL THE LONG TERM PERIOD.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 310 PM EST WED DEC 16 2015
AFTER A SFC COLD FRONT DEPARTS THE REGION LATE THURSDAY...AN
UPPER LEVEL TROUGH SHIFTS INTO THE AREA. POTENT ENERGY WILL BE
SWINGING THROUGH THE BASE OF THE TROUGH ON FRIDAY. THIS COULD
RESULT IN SOME LIGHT SNOW SHOWERS...ESPECIALLY IN THE EASTERN HIGH
TERRAIN. THE BEST CHANCE FOR SNOW SHOWERS WILL BE IN THE AFTERNOON AS
THE BEST UPPER LEVEL ENERGY PASSES THROUGH EASTERN KENTUCKY. EVEN
THOUGH THE COLD TEMPERATURES AND UPPER LEVEL ENERGY ARE
PRESENT...THE MOISTURE IS LACKING. SO DO NOT EXPECT SNOW
ACCUMULATIONS EXCEPT FOR MAYBE A LIGHT COATING OR DUSTING ON
ROOFTOPS/GRASSY AREAS AND IN THE EASTERN HIGH TERRAIN. ROADS
SHOULD STAY WARM ENOUGH TO MELT ANY SNOW THAT DOES FALL ON FRIDAY.
THE SNOW SHOWERS WILL TAPER OFF TO FLURRIES FRIDAY EVENING.
AS THE TROUGH MOVES EAST AND SFC HIGH PRESSURE BUILDS IN FROM THE
WEST...CLOUDS WILL DECREASE ON SATURDAY...BUT A VERY CHILLY AIR
MASS WILL BE IN PLACE. DEPENDENT ON THE CLOUD COVER...TEMPS WILL
GENERALLY FALL INTO THE LOW AND MID 20S FRIDAY NIGHT. THE SFC HIGH
WILL SHIFT SLIGHTLY TO OUR EAST SATURDAY NIGHT WITH WARMER AIR
BEGINNING TO WORK ITS WAY BACK INTO THE REGION. HOWEVER...SATURDAY
NIGHT WILL LIKELY BE THE COLDEST NIGHT WE HAVE SEEN IN AWHILE WITH
CLEAR SKIES AND LIGHT WINDS. THIS SET UP WILL ALLOW TEMPS IN THE
VALLEY LOCATIONS TO FALL INTO THE TEENS...AND RIDGE TEMPS TO DIP
INTO THE LOWER/MID 20S. FORTUNATELY...A SIGNIFICANT WARM UP WILL
OCCUR BEGINNING SUNDAY ALLOWING TEMPERATURES TO REBOUND INTO THE
50S...AND 60S BY MID WEEK.
A MORE ACTIVE WEATHER PATTERN WILL BE IN PLACE NEXT WEEK AS A
SERIES OF IMPULSES WORK THROUGH THE AREA. THE NEXT CHANCE OF RAIN
COMES ON MONDAY AS WE SEE AN INCREASE IN GULF MOISTURE AHEAD OF A
COLD FRONTAL SYSTEM. THE COLD FRONT IS EXPECTED TO STALL NEAR OUR
AREA...AND WITH A MOIST FLOW OFF THE GULF...RAIN CHANCES WILL ALSO
PERSIST THROUGH THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 722 PM EST WED DEC 16 2015
CEILINGS WILL BE DROPPING THROUGH 06Z...WITH RAIN SHOWERS MOVING
IN WEST OF I-75 BETWEEN 02 AND 03Z AS A COLD FRONT APPROACHES.
EXPECT VFR CONDITIONS TO HOLD ON THROUGH 06Z...WITH A QUICK
DETERIORATION DOWN TO IFR OR WORSE EXPECTED FROM WEST TO EAST
BETWEEN 06 AND 12Z AS WIDESPREAD SHOWERS OVERTAKE ALL OF EASTERN
KENTUCKY. CONDITIONS WILL THEN GRADUALLY IMPROVE THROUGH THE REST
OF THE PERIOD FROM WEST TO EAST...WITH SHOWERS COMING TO AN END
FOR MOST LOCATIONS BY EARLY THURSDAY AFTERNOON. SOUTH TO SOUTHWEST
WINDS AT AROUND 5 KTS...WILL SHIFT TO THE NORTHWEST OVERNIGHT FROM
WEST TO EAST AS THE COLD FRONT MOVES ACROSS THE AREA.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...JP
LONG TERM...JVM
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
722 PM EST WED DEC 16 2015
.UPDATE...
ISSUED AT 722 PM EST WED DEC 16 2015
ONLY LIGHT RETURNS HAVE MADE IT INTO OUR AREA THUS FAR THIS
EVENING...WITH THE LOW LEVEL DRY AIR IN PLACE ACROSS EASTERN
KENTUCKY KEEPING THE SHOWER ACTIVITY AT BAY. CLOUD THINNESS IN
THE EAST AND THE LOW DEW POINTS HAVE ALLOWED FOR A QUICK DROP IN
THE SHELTERED VALLEYS...WITH SOME UPPER 40 DEGREE READINGS
CURRENTLY BEING REPORTED. HAVE ADJUSTED THE TEMPERATURES
ACCORDINGLY...WITH A NICE REBOUND EXPECTED IN THE NEXT FEW HOURS
AS THICKER CLOUD COVER MOVES IN. THE LATEST HRRR LINES UP FAIRLY
WELL WITH THE CURRENT RADAR MOSAIC. THERE IS A NICE AREA OF
SHOWERS MOVING IN ACROSS WESTERN TENNESSEE...WHICH WILL BE MAKING
IT INTO OUR SOUTHWEST COUNTIES BETWEEN 9 AND 10 PM. HAVE ADJUSTED
THE POP TIMING A BIT TO CAPTURE THESE TRENDS. JUST BLENDED BACK
INTO THE EXISTING FORECAST THEREAFTER...WHICH REMAINS ON TRACK
FOR WIDESPREAD SHOWERS TO OVERTAKE THE REST OF EASTERN KENTUCKY
THROUGH THE OVERNIGHT HOURS. UPDATES WILL BE OUT SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 315 PM EST WED DEC 16 2015
AS OF MID AFTERNOON A MID LEVEL RIDGE EXTENDED FROM THE CARIBBEAN
NORTH AND NORTHWEST TOWARD THE JAMES BAY REGION WHILE ANOTHER
RIDGE WAS OVER PARTS OF THE EASTERN PACIFIC. IN BETWEEN...A RATHER
BROAD ENCOMPASSED MUCH OF THE ROCKIES AND CENTRAL AND NORTHERN
PLAINS. AN UPPER LEVEL LOW MOVING THROUGH THIS TROUGH IS LOCATED
OVER THE UPPER MS VALLEY WITH A TRAILING SHORTWAVE TROUGH INTO THE
MS VALLEY REGION WHILE ANOTHER SHORTWAVE TROUGH IS UPSTREAM OVER
THE SOUTHERN ROCKIES. YET ANOTHER SHORTWAVE OF NOTE IS DROPPING
THROUGH THE NORTHERN ROCKIES. AT THE SFC...AN AREA OF LOW PRESSURE
IS OVER THE UPPER MS VALLEY REGION WITH A WARM FRONT EXTENDING
INTO THE MID OH VALLEY REGION AND A COLD FRONT TRAILING SOUTH
THROUGH THE MS VALLEY. SHOWERS ARE CURRENTLY OCCURRING ALONG AND
IN ADVANCE OF THIS FRONT OVER WESTERN AND MIDDLE TN AND PARTS OF
CENTRAL KY AS WELL AS SOUTH INTO MS. IN ADVANCE OF THE COLD
FRONT...TEMPERATURES HAVE WARMED AND DRIER AIR HAS MIXED DOWN AT
BRIEFLY WITH TEMPERATURES HAVING REACHED THE 70 AT JKL...AND SOME
OF THE KY MESONET SITES ACROSS THE SOUTHEAST. THE RECORD HIGH HAS
ALREADY BEEN BROKEN AT JKL SO FAR THIS AFTERNOON.
THE TROUGH OVER THE PLAINS AND ROCKIES WILL MOVE INTO THE CENTRAL
AND EASTERN CONUS THROUGH THE PERIOD. THE INITIAL SHORTWAVE
TROUGH AXIS AND THE COLD FRONT WILL APPROACH THE AREA THIS EVENING
INTO THE OVERNIGHT HOURS AND AS THE NEXT UPSTREAM SHORTWAVE NOW OF
THE SOUTHERN ROCKIES MOVES INTO THE SOUTHERN PLAINS AND THE MS
VALLEY REGION...A WAVE OF LOW PRESSURE WILL DEVELOP ALONG THE
BOUNDARY AND MOVE ACROSS THE SOUTHEASTERN STATES. AS THIS
OCCURS...COVERAGE OF SHOWERS SHOULD INCREASE SIGNIFICANTLY AND
WITH THIS TRACKING TO THE SOUTHEAST OF THE AREA...THE HEAVIEST
RAINFALL SHOULD OCCUR CLOSER TO THE VA AND TN BORDERS. GIVEN THE
CURRENT LOWER DEW POINTS ACROSS THAT REGION...HAVE OPTED TO CUT
BACK ON OVERNIGHT QPF ACROSS THE FAR SOUTHEAST PART OF THE AREA.
THE SECOND SHORTWAVE TROUGH AXIS SHOULD CROSS THE AREA ON THU
AFTERNOON WHILE THE SHORTWAVE THAT IS NOW OVER THE NORTHERN
ROCKIES WILL DROP INTO THE CENTRAL PLAINS AND THEN INTO THE MS
VALLEY AND OH VALLEY LATE IN THE PERIOD. BEHIND THE COLD
FRONT...COLD AIR ADVECTION IS ANTICIPATED FOR THU INTO THU NIGHT
AND HAVE OPTED TO GO CLOSER TO A BLEND OF SUPERBLEND AND MOS
GUIDANCE RATHER THAN A CLIMATOLOGICALLY BASED TEMPERATURE CURVE.
LAPSE RATES MAY STEEPEN SUFFICIENTLY ENOUGH FOR SOME FLURRIES BY
LATE IN THE PERIOD...AND TEMPERATURES SHOULD REACH OR FALL BELOW
FREEZING IN WIDESPREAD FASHION ON THU NIGHT FOR THE FIRST TIME IN
ABOUT A WEEK. THE HEART OF THIS COLD AIRMASS THOUGH WILL HOLD OFF
UNTIL THE LONG TERM PERIOD.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 310 PM EST WED DEC 16 2015
AFTER A SFC COLD FRONT DEPARTS THE REGION LATE THURSDAY...AN
UPPER LEVEL TROUGH SHIFTS INTO THE AREA. POTENT ENERGY WILL BE
SWINGING THROUGH THE BASE OF THE TROUGH ON FRIDAY. THIS COULD
RESULT IN SOME LIGHT SNOW SHOWERS...ESPECIALLY IN THE EASTERN HIGH
TERRAIN. THE BEST CHANCE FOR SNOW SHOWERS WILL BE IN THE AFTERNOON AS
THE BEST UPPER LEVEL ENERGY PASSES THROUGH EASTERN KENTUCKY. EVEN
THOUGH THE COLD TEMPERATURES AND UPPER LEVEL ENERGY ARE
PRESENT...THE MOISTURE IS LACKING. SO DO NOT EXPECT SNOW
ACCUMULATIONS EXCEPT FOR MAYBE A LIGHT COATING OR DUSTING ON
ROOFTOPS/GRASSY AREAS AND IN THE EASTERN HIGH TERRAIN. ROADS
SHOULD STAY WARM ENOUGH TO MELT ANY SNOW THAT DOES FALL ON FRIDAY.
THE SNOW SHOWERS WILL TAPER OFF TO FLURRIES FRIDAY EVENING.
AS THE TROUGH MOVES EAST AND SFC HIGH PRESSURE BUILDS IN FROM THE
WEST...CLOUDS WILL DECREASE ON SATURDAY...BUT A VERY CHILLY AIR
MASS WILL BE IN PLACE. DEPENDENT ON THE CLOUD COVER...TEMPS WILL
GENERALLY FALL INTO THE LOW AND MID 20S FRIDAY NIGHT. THE SFC HIGH
WILL SHIFT SLIGHTLY TO OUR EAST SATURDAY NIGHT WITH WARMER AIR
BEGINNING TO WORK ITS WAY BACK INTO THE REGION. HOWEVER...SATURDAY
NIGHT WILL LIKELY BE THE COLDEST NIGHT WE HAVE SEEN IN AWHILE WITH
CLEAR SKIES AND LIGHT WINDS. THIS SET UP WILL ALLOW TEMPS IN THE
VALLEY LOCATIONS TO FALL INTO THE TEENS...AND RIDGE TEMPS TO DIP
INTO THE LOWER/MID 20S. FORTUNATELY...A SIGNIFICANT WARM UP WILL
OCCUR BEGINNING SUNDAY ALLOWING TEMPERATURES TO REBOUND INTO THE
50S...AND 60S BY MID WEEK.
A MORE ACTIVE WEATHER PATTERN WILL BE IN PLACE NEXT WEEK AS A
SERIES OF IMPULSES WORK THROUGH THE AREA. THE NEXT CHANCE OF RAIN
COMES ON MONDAY AS WE SEE AN INCREASE IN GULF MOISTURE AHEAD OF A
COLD FRONTAL SYSTEM. THE COLD FRONT IS EXPECTED TO STALL NEAR OUR
AREA...AND WITH A MOIST FLOW OFF THE GULF...RAIN CHANCES WILL ALSO
PERSIST THROUGH THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 722 PM EST WED DEC 16 2015
CEILINGS WILL BE DROPPING THROUGH 06Z...WITH RAIN SHOWERS MOVING
IN WEST OF I-75 BETWEEN 02 AND 03Z AS A COLD FRONT APPROACHES.
EXPECT VFR CONDITIONS TO HOLD ON THROUGH 06Z...WITH A QUICK
DETERIORATION DOWN TO IFR OR WORSE EXPECTED FROM WEST TO EAST
BETWEEN 06 AND 12Z AS WIDESPREAD SHOWERS OVERTAKE ALL OF EASTERN
KENTUCKY. CONDITIONS WILL THEN GRADUALLY IMPROVE THROUGH THE REST
OF THE PERIOD FROM WEST TO EAST...WITH SHOWERS COMING TO AN END
FOR MOST LOCATIONS BY EARLY THURSDAY AFTERNOON. SOUTH TO SOUTHWEST
WINDS AT AROUND 5 KTS...WILL SHIFT TO THE NORTHWEST OVERNIGHT FROM
WEST TO EAST AS THE COLD FRONT MOVES ACROSS THE AREA.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...JP
LONG TERM...JVM
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
354 PM EST TUE DEC 15 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 247 PM EST TUE DEC 15 2015
LAST OF THE CLOUDS NOW BREAKING UP NORTH OF I-64...SETTING UP
CLEAR SKIES FOR TONIGHT. THIS CLEARING AND A RIDGE SPREADING IN
OVERHEAD SHOULD ALLOW FOR EXCELLENT RADIATIONAL COOLING TONIGHT
WITH VALLEYS FALLING INTO THE LOW TO MID 30S TONIGHT. WITH CROSS
OVER TEMPERATURES SITTING AROUND 40...THIS SETS UP A GOOD
POTENTIAL FOR DENSE VALLEY FOG TONIGHT. THUS...WILL GO AHEAD AND
GO WITH A SPECIAL WEATHER STATEMENT TO COVER THE FOG THREAT LATE
TONIGHT THROUGH WEDNESDAY MORNING. FOG WON`T BE QUICK TO BURN OFF
WITH THE LOWER SUN ANGLE THIS TIME OF YEAR...SO PLAN TO LINGER FOG
IN THE VALLEYS UNTIL AT LEAST 10 AM. SOME FOG COULD LINGER EVEN
PAST 10. AFTER FOG DOES BURN OFF...WE SHOULD SEE ANOTHER MILD DAY
WITH HIGHS BACK INTO THE 60S. WENT CLOSER TO THE MET GUIDANCE IN
THE MID 60S FOR HIGHS AS THE LOW SUN ANGLE AND EARLY MORNING FOG
WILL MAKE IT HARD TO REACH THE MAV NUMBERS CLOSER TO 70. THIS WILL
ALSO MAKE IT DIFFICULT TO REACH OUR RECORD HIGHS TOMORROW...BUT
STILL NOT OUT OF THE QUESTION.
TOMORROW NIGHT...A COLD FRONT WILL PUSH INTO THE OHIO RIVER
VALLEY...AS A POTENT SHORTWAVE PUSHES NORTH OUT OF THE DEEP SOUTH.
THIS WAVE WILL BRING GULF MOISTURE NORTHWARD...LEADING TO
WIDESPREAD SHOWER ACTIVITY THROUGH MUCH OF THE NIGHT. IT APPEARS
RAINFALL WILL HOLD OFF UNTIL WELL AFTER SUNSET. WILL MAINTAIN AND
EXPAND THE CATEGORICAL RAIN CHANCES BACK THE NORTHWEST AS MOST
AREAS WILL SEE RAINFALL FROM THIS SYSTEM. THERE IS A SLIGHT CHANCE
A THUNDERSTORM COULD MAKE IT CLOSE TO THE VIRGINIA/KENTUCKY STATE
LINE...BUT OPTED TO LEAVE THE THUNDER OUT OF THE FORECAST. AS FAR
AS RAINFALL GOES...LOOKS LIKE ABOUT A HALF INCH IN THE SOUTHEAST
TO JUST UNDER A QUARTER OF AN INCH IN THE NORTHWEST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 345 PM EST TUE DEC 15 2015
THE PERIOD IS EXPECTED TO BEGIN WITH RIDGING OVER THE ATLANTIC AND
A RIDGE EXTENDING INTO THE DESERT SOUTHWEST AND PARTS OF THE
EASTERN CONUS WITH A TROUGH EXTENDING SOUTH FROM CENTRAL CANADA
INTO THE PLAINS. A LEAD SHORTWAVE WORKING THROUGH THIS TROUGH IS
EXPECTED TO BE MOVING INTO THE OH VALLEY TO START THE PERIOD. AT
THE SFC...AN AREA OF LOW PRESSURE IS EXPECTED TO BE MOVING THROUGH
ONTARIO WITH A COLD FRONT BECOMING STATIONARY TO A WAVE OF LOW
PRESSURE OVER THE SOUTHERN APPALACHIANS.
FROM THURSDAY INTO FRIDAY...THE LEAD SHORTWAVE WILL WORK ACROSS
THE AREA EARLY IN THE PERIOD ON THURSDAY WITH THE SFC WAVE
TRACKING INTO THE NORTHEAST WITH THE TRAILING COLD FRONT SWEEPING
TO THE EASTERN SEABOARD. MEANWHILE...THE MAIN TROUGH AXIS WILL
MOVE INTO THE EASTERN CONS ON THU NIGHT AND THEN MOVE ACROSS
COMMONWEALTH FRI INTO FRIDAY NIGHT. THIS TROUGH WILL USHER IN AN
AIRMASS AS COLD IF NOT SLIGHTLY COLDER THAN THE ONE THAT AFFECTED
THE AREA AROUND NOVEMBER 22ND TO 23RD. HOWEVER...THIS COLDER
AIRMASS WILL BE SHORT LIVED AS HEIGHTS WILL RISE OVER THE WEEKEND
AS RIDGING BUILDS FROM THE GULF OF MEXICO TOWARD BERMUDA AND
ACROSS THE SOUTHEAST. AT THE SAME TIME...A BROAD TROUGH WILL
SPREAD ACROSS MUCH OF THE WESTERN US TO THE PLAINS. THIS SHOULD
BRING MODERATING TEMPERATURES OVER THE WEEKEND...WITH ABOVE NORMAL
TEMPERATURES RETURNING ON SUNDAY. BY THE END OF THE PERIOD... THE
AXIS OF A BROAD TROUGH IS EXPECTED TO EXTEND THROUGH THE PLAINS
WITH A RIDGE CENTERED NEAR BERMUDA AND ANOTHER RIDGE OVER THE
PACIFIC. AS THE TROUGH MOVES EAST TO END THE WEEKEND AND EARLY
NEXT WEEK...A CORRESPONDING SFC LOW SHOULD TRACK TO THE NORTHWEST
OF THE AREA... WHILE RETURN MOISTURE SPREADS NORTH INTO THE MS AND
OH VALLEYS. THIS MILD AND MOIST SOUTHWEST FLOW PATTERN SHOULD
LINGER INTO THE MIDDLE OF NEXT WEEK.
AN AREA OF SHOWERS SHOULD LINGER INTO THE START OF THE LONG TERM
PERIOD ACROSS THE SOUTHEASTERN PART OF THE AREA ESPECIALLY. THEN
AS A SHORTWAVE MOVES IN FROM THE WEST AND 850 MB TEMPS COOL
LEADING TO INCREASING LAPSE RATES...ISOLATED TO POSSIBLY
SCATTERED SNOW SHOWERS AND FLURRIES WILL BE POSSIBLE MAINLY ON
FRIDAY. THERE REMAINS SOME MODEL DIFFERENCES IN WHEN CHANCES OF
THIS WILL BE BEST THOUGH SOME OF THE GUIDANCE POINTS TOWARD MIDDAY
INTO THE AFTERNOON WHICH WOULD ALSO CORRESPOND TO PEAK HEATING.
WITH COLD ADVECTION ANTICIPATED...THE NEW 12Z EC BASED MOS
GUIDANCE APPEAR MORE REASONABLE THAN THE 12Z MEX MOS OR SUPERBLEND
HIGHS FOR FRIDAY. FOR FRIDAY...HELD MAX T IN THE 30S. EVEN WITH
SFC TEMPERATURES POSSIBLY ABOVE FREEZING...FORECAST NEARLY DRY
ADIABATIC LAPSE RATES AND RATHER DRY SUB CLOUD LAYER SHOULD LEAD
TO ANYTHING THAT DOES FALL ON FRIDAY TO FALL AS SNOW.
THE COLDEST NIGHT OF THE LONG TERM PERIOD SHOULD BE ON SAT NIGHT
AS SFC AND UPPER LEVEL RIDGING BUILD ACROSS THE AREA. FOR THIS
PERIOD WE HAVE OPTED TO UNDERCUT THE SUPERBLEND GUIDANCE AND WENT
MORE IN LINE WITH COOP MOS GUIDANCE FOR LOWS IN VALLEYS ON SAT
NIGHT...WHERE TEENS WILL BE POSSIBLE. ABOVE NORMAL TEMPERATURES
ARE EXPECTED BY THE END OF THE WEEKEND AND CONTINUING INTO THE
FIRST HALF OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1252 PM EST TUE DEC 15 2015
OUTSIDE OF SOME MVFR CIGS NORTH OF I-64 OVER THE NEXT FEW
HOURS...VFR CONDITIONS ARE EXPECTED THROUGH MOST OF THE PERIOD.
SOME LOCALLY DENSE VALLEY FOG IS ANTICIPATED TONIGHT...BUT IS NOT
EXPECTED TO IMPACT OUR TAF SITES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KAS
LONG TERM...JP
AVIATION...KAS
Area Forecast Discussion
National Weather Service Louisville KY
250 PM EST TUE DEC 15 2015
.SHORT TERM (Now through Wednesday)...
Issued at 245 PM EST Tue Dec 15 2015
Cloud trends this evening, fog potential overnight and shower
chances Wednesday are the main forecast challenges in the short
term.
As of mid-afternoon, water vapor imagery and 500 mb heights showed
the lower Ohio Valley under a weak ridge, between two closed lows
over the CONUS. At the surface, high pressure axis was from north FL
through lower MI. A 50-100 mb thick stratus deck trapped around 2-3
kft has been slowly eroding and lifting northward thanks to
increasing south winds and daytime mixing. Temperatures were in the
50s.
Using visible satellite trends and the HRRR cloud fields, expecting
back edge of the cloud deck to continue work its way northward,
reaching our southern Indiana counties by sunset. The limited mixing
today coupled with light winds right at the surface and high
pressure overhead will promote patchy to areas of fog to develop
across the area overnight through early morning hours. The SREF
probabilities and hi-res model visibility plots show the highest
threat to be across the Lake Cumberland to Bluegrass regions,
especially in the river valleys and other typical fog prone areas.
The main limiting factor for dense fog looks to be increasing
south/southwest winds just off the deck overnight that could keep
the boundary layer mixed enough. Otherwise, plan on lows in the
upper 30s to mid 40s.
A surface low will track from the central Plains to the Upper
Midwest overnight into Wednesday. A moisture-limited cold front will
cross the forecast area late tomorrow morning into the afternoon
hours. Dynamics aren`t impressive and moisture transport is narrow
as it crosses the region, so continued to keep shower chances in the
20-40 percent range, mostly in the afternoon hours. We should warm
up nicely ahead of this system, topping out in the low to mid 60s
with steady south winds 10-20 mph.
.LONG TERM (Wednesday Night through Monday)...
Issued at 250 PM EST Tue Dec 15 2015
Wednesday Night - Thursday
The cold front will slow down Wednesday night as it crosses the
region, stalling somewhat over eastern Kentucky while a southern
stream impulse lifts more moisture back to the north. More
widespread rain will then overspread east of I-65, especially along
the I-75 corridor through the Thursday morning commute. Plan on lows
to range from the mid 30s west of I-65, to the low/mid 40s along the
I-75 corridor under deeper clouds and rain. Precipitation should
quickly end west to east Thursday morning.
A digging upper trough will bring seasonably cold air into the
region, as seen by crashing 850 mb temperatures throughout the day.
Temperatures won`t rise too much or even remain steady, especially
in our northwest. Highs in the mid 40s to low 50s.
Friday - Friday Night
The bulk of the cold airmass will be overhead during this time frame
as the upper trough axis swings through the lower Great Lakes into
the mid-Atlantic regions. A quick moving shortwave will round the
base of the trough. As the case with these clippers, moisture is
limited but some of that moisture does lie within the dendritic
growth zone /-10 to -15C/. A flurry or sprinkle, depending on
boundary layer temps, is possible across the northern forecast area,
say from Louisville metro and points east/north. Plan on highs in
the mid 30s to low 40s, and lows Friday night solidly in the 20s.
Saturday - Sunday
A dry and seasonable weekend is expected over the region. After a
slow start, temperatures will warm to the low and mid 40s on
Saturday under sunny skies. Surface high pressure moves east by
Saturday night, with light southerly flow returning.
This sets up our typical ridge/valley split nights where eastern
decoupled valleys stay in the low and mid 20s. Elsewhere, mixed
locations will see upper 20s to around 30. Milder conditions return
for Sunday under a steady south flow. Look for highs in the lower
50s.
Monday - Tuesday
A more active weather pattern is looking increasingly likely over
the area next week as a series of impulses lift out of the Plains to
the Great Lakes. Synoptically, a trough out west with ridging over
the east will favor above normal temperatures and chances of rain.
&&
.AVIATION (18Z TAF Update)...
Updated at 1228 PM EST Tue Dec 15 2015
MVFR conditions will persist at KSDF and KLEX for a few more hours
this afternoon before all sites return to VFR late this afternoon
into the overnight hours. MVFR stratus deck has shown some signs of
mixing out the past couple of hours via satellite imagery, thus will
trend more optimistically at KSDF/KLEX. Winds will go light and
variable tonight with just a few passing high clouds. Some guidance
suggests that fog is possible mainly at KLEX/KBWG. Given the
copious amounts of fog the past couple of weeks, don`t want to
completely discredit the more pessimistic solutions. Therefore,
will introduce a TEMPO vsby restriction at KLEX/KBWG, but ultimately
think an increasing pressure gradient and 15-20 knot winds at the
top of the low-level inversion will limit duration/density of any
fog.
Conditions will be VFR by Wednesday morning but mid-level clouds
will be on the increase out ahead of an approaching storm system
slated to move through late Wednesday afternoon into Wednesday night.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Short Term........ZT
Long Term.........ZT
Aviation..........KJD
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
1138 PM CST MON DEC 14 2015
.UPDATE...
Issued at 1138 PM CST MON DEC 14 2015
Update for 06Z TAFs only.
UPDATE Issued at 905 PM CST MON DEC 14 2015
Low stratus is the primary issue this evening. We originally
thought that there would be steady southwest to northeast clearing
trend through the evening, but that is not the case. Satellite
trends indicate that the low stratus is oozing southward now
reaching KCGI and just north of KPAH. This layer extends back to
near KSGF, so it is not going away quickly. The RAP 925mb RH
forecast has a decent handle on the situation, so followed it
fairly closely through the night. Figure that the clearing will
occur from southwest to northeast Wednesday morning.
Under the solid cloud cover, temperatures are not likely to fall
much, if at all, tonight. There will be a rather sharp gradient to
the south of the clouds where radiational cooling is likely, but
we are not sure where that southern edge of the clouds is going to
set up.
The AVIATION section has some mid-evening thoughts as well.
&&
.SHORT TERM...(This evening through Wednesday)
Issued at 143 PM CST MON DEC 14 2015
Our region will be under a brief period of ridging between
systems tonight and Tuesday. This will bring dry and more
tranquil conditions, with seasonably mild temperatures. Another
vigorous low pressure system will bring a cold front into the
region on Wednesday. Though the mid level trof looks formidable,
little chc for deep moisture return and weak convergence in the
lower levels will likely limit and any precip to very light rain.
Most locations should see from a few hundredths to less than a
tenth of an inch rain totals from this frontal passage.
.LONG TERM...(Wednesday night through Monday)
Issued at 143 PM CST MON DEC 14 2015
Surface high pressure will be centered to our southwest for the end
of the workweek. This will keep the winds across the PAH forecast
area from the northwest on Thursday and west on Friday, which will
continue to filter more seasonal air into the region. High
temperatures will be in the 40s on Thursday, and in the upper 30s to
upper 40s on Friday, with overnight lows in the 20s. A weak upper
level trof will move across the middle Mississippi and lower Ohio
valleys Thursday night, but this will do little more than give us an
increase in clouds.
By Saturday, models show the surface high moving over the southeast
U.S. This will cause winds to gradually shift back to the south on
Saturday. Along with a lot of sunshine, this will help temperatures
begin to rebound, with readings by Sunday and Sunday night back
to well above seasonal normals.
Models show a cold front approaching our area Sunday night, with
precipitation spreading across the PAH forecast area late Sunday
night and Monday. GFS is a bit faster than the ECMWF, but the
overall general timing is in decent agreement. Went with slight to
low chance pops for showers Sunday night in southeast Missouri and
portions of southern Illinois and far west Kentucky. Both models
show a little bit of low level CAPE on Monday, so included isolated
thunderstorms with our area wide shower chances.
&&
.AVIATION...
Issued at 1138 PM CST MON DEC 14 2015
MVFR stratus deck over MO has pushed east into the region and will
continue to plague KEVV/KOWB through the morning hrs and possibly
into some of the afternoon tmrw. KCGI will be on the edge of the
low stratus deck overnight before it pushes further north toward
morning. Right now KPAH expected to be just south of the MVFR cigs
but it will be close. Southerly winds will usher in drier air tmrw
afternoon which should eventually lead to the low clouds clearing
from KEVV/KOWB at some point tmrw PM.
&&
.PAH Watches/Warnings/Advisories...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SP
SHORT TERM...MEFFERT
LONG TERM...RST
AVIATION...SP
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
323 PM CST TUE DEC 15 2015
.DISCUSSION...CLEAR SKIES AND LOW RELATIVELY HUMIDITY VALUES TODAY
CAN BE VERY DECEIVING AS WEATHER CONDITIONS 24 HOURS FROM NOW WILL
BE QUITE DIFFERENT. A DEEP TROUGH HAS DROPPED SOUTHEAST FROM THE
PACIFIC NW WITH AN EMBEDDED CLOSED LOW RACING NORTHEAST ACROSS THE
CENTRAL PLAINS. MOISTURE LEVELS WILL BEGIN TO RISE ON OVERNIGHT AS
SFC RIDGE TO THE NORTHEAST BRINGS HAS ALLOWED WINDS BRING THE RETURN
OF ONSHORE FLOW. MODEL SOUNDS INDICATE PRECIP WATER VALUES RISING
FROM BARELY A QUARTER OF AN INCH TODAY TO WELL OVER 1.5 INCHES
MIDDAY WED. A COLD FRONT ASSOCIATED WITH THE UPPER LOW WILL BE
APPROACHING THE TX/LA BORDER EARLY WEDNESDAY MORNING. SHOWERS WILL
BEGIN TO DEVELOP OUT AHEAD OF THE SYSTEM BUT NOT UNTIL EARLY WED
MORNING. THE HRRR SHOWS LIGHT SHOWERS CLOSING IN ON THE CWA FROM THE
WEST AND GULF MAINLY AFTER 06Z TONIGHT...SO HAVE ADJUSTED POPS
ACCORDINGLY WITH SLIGHT CHANCE TO CHANCE ALONG THE COASTAL AREAS AND
LESS THAN ISOLATED FURTHER INLAND. MODELS IN GOOD AGREEMENT THAT THE
FRONT WILL REACH WESTERN PORTIONS OF THE CWA AROUND NOON WEDNESDAY.
NO SIGNIFICANT CHANGES MADE TO POPS FOR WEDNESDAY. PLUME OF MOISTURE
SATURATE THE COLUMN AND LIFT ALONG THE BOUNDARY COMBINED WITH
PRESSURE FALLS WILL PROMOTE WIDESPREAD SHOWER DEVELOPMENT. MODEL
SOUNDINGS SHOWING SLIGHTLY MORE INSTABILITY THAN PREVIOUS RUNS BUT
STILL FAIRLY MEAGER AND ALL ELEVATED. THE INSTABILITY WILL BE
GREATEST ALONG THE COAST IN THE "WARM SECTOR". IF THERE ARE ANY
STRONGER STORMS...IT WILL BE IN THIS REGION. MAIN THREAT WILL BE
STRONG DOWNDRAFT WINDS. THINKING IT WILL BE MORE OF AN SPS DAY
RATHER THAN SVR ONE IF ANY STORMS INTENSIFY.
BACK SIDE OF THE RAIN TO BE COMING ACROSS THE CWA THURSDAY MORNING.
ALTHOUGH THERE MAY STILL BE SHOWERS IMPACTING COASTAL PARISHES AND
COUNTIES OF LA AND MS....THIS ACTIVITY SHOULD BE OFFSHORE BY AROUND
NOON. STRONG HIGH PRESSURE WILL THEN BUILD IN THROUGH THE REST OF
THE WEEK AND MOST OF THE WEEKEND. A MORE SUBSTANTIAL DROP IN TEMPS
EXPECTED WITH THIS BOUNDARY AS THIS TROUGH WILL TRANSFER MORE
CONTINENTAL AIRMASS THAN PREVIOUS. LOOKING LIKE HIGHS IN THE UPPER
50S AND LOWER TO MID 30S FOR NIGHTTIME LOWS ALONG AND NORTH OF I-12
FOR A COUPLE DAYS BEFORE GRADUALLY MODERATING BACK TO CLIMO NORMS
LATE WEEKEND/EARLY NEXT WEEK.
MEFFER
&&
.AVIATION...VFR STATUS EXPECTED TO CONTINUE THROUGH 6Z AT ALL
TERMINALS. AFTER THAT LL MOISTURE WILL BEGIN TO INCREASE AND
INCREASE QUICKLY. BY 8/9Z MOST TERMINALS WILL BEGIN TO BE IMPACTED
BY STRATUS WITH CIGS GENERALLY B/T 1200-2500 FT. ALL TERMINALS WILL
BE IN MVFR STATUS DUE TO LOW CIGS BEFORE SUNRISE. IN ADDITION TO THE
LOW CIGS SOME PATCHY LIGHT FOG COULD ALSO DEVELOP IN A FEW LOCATIONS
THOUGH LL WINDS MAY BE JUST STRONG ENOUGH TO KEEP FOG FROM REALLY
DEVELOPING. /CAB/
&&
.MARINE... ERLY FLOW IS ALREADY DEVELOPING OVER THE COASTAL WATERS A
LOW PRESSURE WILL BEGIN TO TAKE SHAPE OVERNIGHT TONIGHT AND EARLY
TOMORROW IN THE NWRN GULF. THE SFC LOW WILL TRAVERSE ACROSS THE CWA
TOMORROW AND TOMORROW EVENING BEFORE PUSHING INTO AL OVERNIGHT WED.
AF THAT A COLD FRONT WILL MOVE THROUGH. AHEAD OF THE LOW MODERATE TO
BRIEF STRONG ONSHORE FLOW WILL DEVELOP BUT THE STRONGEST WINDS (20-
25KTS W/HIGHER GUSTS) AND HIGHEST SEAS(5-8FT) WILL BE POST FRONTAL
THU AND ESPECIALLY THU NIGHT AS THE STRONGEST CAA TAKES PLACE. SCY
ADV WILL BE NEEDED BEHIND THE COLD FRONT BUT EXERCISE CAUTION
HEADLINES MAY ONLY BE NEEDED AHEAD OF THE FRONT TOMORROW. /CAB/
&&
.DECISION SUPPORT...
DSS CODE....GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...NONE.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 53 70 49 62 / 10 80 70 10
BTR 57 72 51 63 / 10 80 60 10
ASD 58 72 58 63 / 20 80 70 10
MSY 62 74 59 63 / 10 80 70 10
GPT 59 70 61 65 / 20 80 80 20
PQL 58 72 63 66 / 20 80 90 30
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1244 PM EST TUE DEC 15 2015
.SYNOPSIS...
INTENSE LOW PRESSURE ALONG THE MAINE COAST THIS MORNING WILL
RAPIDLY MOVE EAST OF NOVA SCOTIA TONIGHT. HIGH PRESSURE WILL BUILD
IN WEDNESDAY AND MOVE EAST THURSDAY. A FRONTAL SYSTEM WILL
APPROACH THURSDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
1245 PM UPDATE...
SFC LOW IS DOWN TO 983 MB JUST ENTERING NOVA SCOTIA AT THIS TIME.
MOST OF CWA IS SNOW AT THIS TIME WITH PRECIP PIVOTING. BEST
BANDING LOOKS TO BE OVR ERN ZONES WITH ADDN/L BANDING OVR CNTRLPORTIONS
OF THE AREA. UPDATED WINTER HEADLINES TO ADD NRN WASHINGTON AND
CNTRL PENOBSCOT INTO WINTER WX ADVISORY AS THEY WILL CONTINUE WITH
MODERATE TO HVY SNOW FOR THE NEXT SVR HRS.
FURTHER TO THE SOUTHWEST PCPN IS WINDING DOWN AND WL LKLY GO TO
SNOW SHOWERS IN THE NEXT HR OR TWO. LATEST RUC HAS DONE AN
EXCELLENT JOB NAILING THE AREA OF FRONTOGENESIS ONGOING AND SHIFTS
IT EAST INTO NEW BRUNSWICK OVR THE NEXT SVRL HRS.
ZONES CLOSER TO THE COAST ARE JUST NOW BEGINNING TO MIX OVR PER
LATEST REPORTS AND THIS AGREES WITH RADAR POPUP SKEW-T. HV REVISED
POP, WX AND TEMP GRIDS WITH THIS UPDATE.
PREV DISCUSSION BLO...
INTENSE LOW PRESSURE IS CURRENTLY MOVING INTO THE SOUTHWESTERN
PORTION OF QUEBEC PROVINCE. THIS SYSTEM IS EXPECTED TO QUICKLY
FILL AS A SECONDARY LOW PRESSURE DEVELOPS ALONG THE MAINE COAST
THIS MORNING. WARM AIR HAS MOVED IN ACROSS THE MID LEVELS IN THE
NORTH AND ALL LEVELS SOUTH AS A RESULT OF THE FLOW AHEAD OF THE
PRIMARY LOW. AS THE SECONDARY LOW DEVELOPS COLD AIR WILL RETURN AT
ALL LEVELS LATER THIS MORNING AND AFTERNOON. A PROLONGED PERIOD OF
SLEET IS EXPECTED IN THE NORTH PRIOR TO THE RETURN OF THE COLD
AIR. SNOW IS EXPECTED IN THE NORTH DURING THE AFTERNOON. THE SNOW
IS THEN EXPECTED TO END BY LATE EVENING AS THE LOW PRESSURE SYSTEM
MOVES EASTWARD ACROSS NOVA SCOTIA INTO THE ATLANTIC. HIGH PRESSURE
WILL BUILD IN FROM THE NORTHWEST BEHIND THE LOW.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL BE IN CONTROL FOR WEDNESDAY AND THEN ANOTHER
SYSTEM IS FORECAST TO AFFECT THE REGION ON THURSDAY.
TEMPERATURES THIS TERM ARE EXPECTED TO BE ABOVE NORMAL BUT NOT
NEARLY AS WARM AS WE HAD SEEN OVER THE LAST WEEK. DRIER CONDITIONS
AND COLDER AIR WILL BE OVER THE REGION ON WEDNESDAY W/AT LEAST
PARTLY SUNNY SKIES ACROSS THE N AND W WHILE DOWNEAST AND THE COAST
WILL SEE MORE SUN DUE TO THE NW WIND AND DOWNSLOPE EFFECT. THE NW
FLOW COMING OFF THE OPEN ST. LAWRENCE WILL HELP KEEP THE CLOUDS IN
ACROSS THE N AND W W/THE POTENTIAL FOR SOME FLURRY ACTIVITY. ATTM,
DECIDED TO KEEP POPS BELOW 20% AS DEEP OF LLVL MOISTURE IS LIMITED
TO 900MBS AND BELOW. DAYTIME TEMPERATURES ON WEDNESDAY WILL BE IN
THE UPPER 20S TO LOWER 30S NORTHERN 1/2 OF THE CWA WHILE CENTRAL
AND DOWNEAST WILL SEE LOW TO MID 30S.
A SSE FLOW DEVELOP LATER WEDNESDAY NIGHT AS THE HIGH MOVES E. THIS
IN TURN WILL ALLOW FOR A LOW CLOUD DECK TO DEVELOP OVERNIGHT INTO
THURSDAY MORNING. A WARM FRONT AND A LLVL JET ALOFT WILL AID IN
SOME FORCING ALLOWING FOR LIGHT SNOW TO BREAK OUT FROM SW TO NE
DURING THE DAY ON THURSDAY. MDL SOUNDINGS SHOW THE COLUMN TO
MOISTEN BY LATE IN THE DAY W/WAA TAKING HOLD. GIVEN THE POSITION
OF THE HIGH, TEMPERATURES SHOULD WARM FAIRLY QUICKLY BY EARLY
THURSDAY EVENING W/MOST LOCATIONS INCLUDING THE ST. JOHN VALLEY
SEEING A CHANGE FROM SNOW TO RAIN. ATTM, SNOWFALL ACCUMULATIONS
ARE EXPECTED TO BE LIGHT. TEMPERATURES WILL CONTINUE TO CLIMB
THURSDAY NIGHT AS THE WARM FRONT LIFTS N. TEMPS WILL RISE WELL
INTO THE 30S ACROSS THE N WHILE CENTRAL AND DOWNEAST AREAS WILL
SEE LOWER 0S. WX ELEMENT WILL BE RAIN W/MUCH MELTING OF THE SNOW.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
TURNING COLDER FOR THE WEEKEND.
THE LATEST RUNS OF THE LONG RANGE GUIDANCE INCLUDING THE ECMWF AND
GFS SHOW LOW PRES DEVELOPING ON THE WARM FRONT FRIDAY MORNING AND
LIFTING NE INTO THE MARITIMES. THIS WILL ENHANCE RAINFALL
ESPECIALLY ACROSS EASTERN AREAS ON FRIDAY. THE ASSOCIATED COLD
FRONT IS FORECAST TO SWING ACROSS THE AREA FRIDAY AFTERNOON W/CAA
BEHIND THE FRIDAY. ANY LEFTOVER RAIN SHOWERS COULD CHANGE TO SNOW
SHOWERS BEFORE ENDING FRIDAY EVENING WITH LITTLE IF ANY
ACCUMULATION EXPECTED. THE 00Z RUN OF THE ECMWF HAS BACKED OFF ON
BRINGING A SECOND LOW PRES UP ALONG THE MAINE COAST FRIDAY NIGHT
INTO SATURDAY AND NOW PUSHES IT FURTHER E. THE 00Z GFS AND MOST OF
ITS ENSEMBLES SUPPORT JUST THE COLD FRONT SWEEPING THROUGH THE
REGION AS DOES THE CANADIAN GLOBAL RUN.
CAA COMES IN EARNEST FRIDAY NIGHT INTO SATURDAY W/A TROF OF LOW
PRES SLIDING ACROSS THE REGION FROM QUEBEC. THIS FEATURE COULD
KICK OFF SOME SNOW SHOWERS/SQUALLS PLUS ST. LAWRENCE OPEN FOR
BUSINESS IN REGARDS TO THE STREAMERS. GFS SOUNDINGS DO SHOW CAPES
ABOVE 50 JOULES AND DECENT LOW/MID LEVEL LAPSE RATES TO SUPPORT
INSTABILITY. STILL PLENTY OF TIME AS WE CLOSE IN ON THE WEEKEND.
TEMPERATURES LOOK TO BE AT SEASONAL LEVELS ON SATURDAY.
HIGH PRES IS FORECAST TO MOVE ACROSS THE CAROLINAS ON SUNDAY
ALLOWING FOR RIDGING TO OCCUR OVER THE NEW ENGLAND REGION. THIS
WILL LEAD TO SUNSHINE AND NEAR SEASONAL TEMPS TO CONTINUE.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
NEAR TERM: MVFR/IFR RESTRICTIONS EXPECTED NEXT 24 HOURS AT ALL
TERMINALS WITH EXCEPTION OF BHB. N-NE WINDS WILL GUST TO 20KTS
THIS EVENING THEN DIMINISH DURING THE OVERNIGHT.
SHORT TERM: MVFR CIGS ACROSS THE NORTHERN TERMINALS N OF KHUL
FOR WEDNESDAY. VFR ELSEWHERE. CONDITIONS DROP TO MVFR WEDNESDAY
NIGHT ACROSS THE NORTHERN TERMINALS INCLUDING KHUL AND THEN
POSSIBLE IFR BY THURSDAY AND POSSIBLY SOME LIGHT SNOW. MVFR CIGS
ARE POSSIBLE FOR KBGR AND KBHB THURSDAY MORNING W/IFR BY THE
AFTERNOON. IFR AND PERHAPS LIFR FOR ALL TERMINALS THURSDAY NIGHT
INTO FRIDAY W/RAIN.
&&
.MARINE...
NEAR TERM: HAVE USED THE NAM12 FOR SUSTAINED WIND SPEEDS. FOR
WAVES: A SOUTHEASTERLY FETCH WILL PERSIST ACROSS THE GULF OF MAINE
EARLY THIS MORNING UNTIL BROKEN UP BY A WIND SHIFT BEHIND THE
DEPARTING LOW PRESSURE LATER IN THE MORNING. WAVE HEIGHTS IN THE
SOUTHEASTERLY WAVE GROUP WILL BUILD TO 8 FEET/8-9 SECONDS BY LATE
THIS AFTERNOON THEN SUBSIDE TONIGHT. WIND WAVE IN AN OFF-SHORE
FETCH TONIGHT WILL THEN BECOME THE PRIMARY WAVE SYSTEM WITH WAVE
HEIGHTS A FUNCTION OF DISTANCE OFF SHORE. WILL KEEP TIMING OF GALE
AND SCA CONDITIONS. HAVE USED THE NEAR SHORE WAVE MODEL FOR WAVE
HEIGHTS.
SHORT TERM: SCA CONDITIONS EARLY WEDNESDAY. CONDITIONS WILL IMPROVE
BY MIDDAY W/WINDS AND SEAS DROPPING OFF AS HIGH PRES BUILDS ACROSS
THE WATERS DURING THE AFTERNOON. A RETURN TO SCA FOR LATER IN THE
DAY ON THURSDAY RIGHT INTO THURSDAY NIGHT. SSE WINDS EXPECTED TO
INCREASE TO 25 KTS W/SEAS BUILDING TO 6 TO 7 FT. LOW PRES
DEVELOPING ON THE WARM FRONT WILL LIFT NE ON FRIDAY W/A LULL AND
THEN WINDS WILL PICK UP AS A COLD FRONT SWINGS THROUGH THE REGION.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MEZ001-
002.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
MEZ003>006-010-011-032.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ052.
GALE WARNING UNTIL 1 AM EST WEDNESDAY FOR ANZ050-051.
&&
$$
NEAR TERM...FARRAR/MIGNONE
SHORT TERM...HEWITT
LONG TERM...HEWITT
AVIATION...FARRAR/MIGNONE/HEWITT
MARINE...FARRAR/MIGNONE/HEWITT
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
855 PM EST WED DEC 16 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. A WAVE OF LOW
PRESSURE MOVING ALONG A COLD FRONT WILL IMPACT THE REGION ON
THURSDAY. HIGH PRESSURE WILL RETURN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY NIGHT/...
SFC RIDGE EXTENDS WWD TO INCL THE CWFA THIS EVNG. VARIED CLDS
ATTM...MOSTLY HIGH DECK BUT SOME LWR CLDS INVOF NE MD. THUS FAR
/LT TAFTN-ELY EVNG/ THESE CLDS SHOW NO SIGNS OF INLAND MVMT. DONT
BELIEVE THAT WL CHG PER SE. HWVR...AS FNT APPROACHES...THERE WL BE
INLAND MSTR ADVCTN DUE TO ELY FLOW OVER THE ATLC. THINK THE BIGGER
CLD THREAT WL COME FM CLD DVLPMNT TWD DAWN IN RESPONSE TO INCRSD
OVERRUNNING. THAT WUD PLACE THE ERN SLOPES OF THE BLURDG FIRST.
THERE IS DECENT TIMING DIFFS WRT ARRIVAL OF PCPN. INDEED...LTST
RADAR COMPOSITE NOT THAT IMPRESSIVE. HRRR HAS BEEN BACKING OFF
WITH EACH CONSECUTIVE RUN...WHICH MATCHES THINKING OF 18Z GFS.
BELIEVE THEY/RE ONTO SOMETHING...AND HV EDGED TIMING LATER...MORE
INTO THU MRNG.
A FRONTAL WAVE WILL LIFT QUICKLY NNE FROM THE GULF STATES TO NYC
BY THU EVENING. GOOD MOISTURE TRANSPORT ALONG AND AHEAD OF THIS
WAVE. ONCE RAIN STARTS...IT WL PERSIST FOR THE BALANCE OF THE
DAY. LTST QPF FCSTS KEEP TTLS AOB AN INCH...WITH THE HIEST VALUES
ACRS CENTRAL VA/SRN MD.
RAIN WILL QUICKLY EXIT THE REGION THU EVENING AND SHOULD BE SOUTH
AND EAST OF THE AREA BY DAYBREAK FRI. COLDER AIR WILL START
FILTERING INTO THE MTNS LATE THU NIGHT WITH ANY PRECIP OVER THE
POTOMAC HIGHLANDS CHANGING TO SNOW SHOWERS ALTHOUGH MODEL
SOUNDINGS INDICATE LACK OF ICE CRYSTALS EARLY FOR ANY
ACCUMULATIONS THROUGH 12Z FRI.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
THE PARENT LOW PRESSURE SYSTEM RESPONSIBLE FOR BRINGING A COLD
FRONT INTO THE AREA THURSDAY WILL HAVE MOVED WELL INTO CANADA BY
FRIDAY MORNING. MEANWHILE...SECONDARY LOW PRESSURE WHICH WILL BE
RESPONSIBLE FOR THE WIDESPREAD RAIN ON THURSDAY WILL DEPART INTO
THE CANADIAN MARITIMES. THE UPPER-TROUGH DRIVING THESE FEATURES
WILL PIVOT ACROSS THE AREA FRIDAY. BOOSTED SKY COVER A BIT WITH
THE STRONG TROUGH AXIS/PVA MOVING ACROSS AND MOISTURE TRAPPED
BETWEEN 4000-7000 FEET.
OF NOTE...A FEW OUTLIER ENSEMBLE MEMBERS HAVE A BAND OF LIGHT
SNOW SPREADING ACROSS THE AREA FRIDAY IN ASSOCIATION WITH THE
AFOREMENTIONED STRONG SHORTWAVE. BUT THIS IS A LOW PROBABILITY
SOLUTION AT THIS TIME AND NOT REFLECTED IN THE DETERMINISTIC
FORECAST.
A MUCH COOLER AIRMASS WILL DIVE INTO THE REGION BEHIND THIS
SYSTEM...WITH 850 MB TEMPERATURES FALLING TO -10 TO -12 C BY
SATURDAY MORNING. THIS WILL SUPPORT WIDESPREAD LOWS IN THE 20S AND
LOWER 30S WITH WIND CHILLS IN THE TEENS AND 20S ON A GUSTY WEST WIND
OVERNIGHT. WESTERLY FLOW AND TRAPPED MOISTURE AMIDST THE COLD AIR
SHOULD BE ABLE TO SQUEEZE OUT SOME UPSLOPE SNOW SHOWERS ACROSS THE
WESTERN RIDGES FRIDAY AFTERNOON INTO FRIDAY NIGHT. DESPITE THE
STRONG PVA...THE LOW-LEVEL WIND DIRECTION IS LESS THAN IDEAL...SO
ALTHOUGH SNOW SHOWERS ARE LIKELY ACCUMULATIONS SHOULD BE RELATIVELY
LIGHT /GENERALLY 0.5 TO 1 INCH OR SO/.
COUPLED WITH THE STRONG COLD ADVECTION/PRESSURE SURGE IS A POTENTIAL
FOR GUSTY WINDS OVER THE RIDGELINES NEARING WIND ADVISORY CRITERIA
/I.E. 45 MPH/ BY EARLY SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MAIN WEATHER STORY THIS WEEKEND WILL BE BREEZY AND COOLER WEATHER
SATURDAY IN MODERATE CAA. HIGHS SATURDAY ONLY A FEW DEGREES COLDER
THAN NORMAL...THOUGH RECENT WARM WEATHER WILL MAKE IT FEEL MUCH
COOLER...ESPECIALLY WITH THE WIND. HIGH PRESSURE BUILDS TO OUR
SOUTH SATURDAY INTO SUNDAY...ALLOWING WINDS TO SUBSIDE AND
TEMPERATURES TO MODERATE SOME. HIGH MOVES OFFSHORE LATE
SUNDAY...WITH SOUTHERLY WINDS AND WAA COMMENCING. THIS WILL SET UP
ANOTHER EXTENDED STRETCH OF ABOVE NORMAL TEMPERATURES...WITH
TEMPERATURES BACK IN THE 60S BY NEXT TUESDAY. NEXT CHANCE OF
PRECIPITATION ARRIVES NEXT WEEK. UNCERTAINTY IS HIGH WITH
TIMING...AS LARGE SPREAD EXISTS IN GUIDANCE...THOUGH APPEARS RAIN
WILL BE LIKELY AT SOME POINT.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
VFR CONDS ATTM...WHICH SHUD PREVAIL TIL ELY MRNG. AFTER THAT THE
COMBO OF AN ADVCG FNT FM THE W AND ONSHORE /ELY/ SFC FLOW SHUD
LEAD TO RATHER RAPID CLD DVLPMNT. BELIEVE THAT THESE CLDS WL DVLP
FIRST ALONG THE ERN SLOPES OF THE BLURDG. THE END RSLT WL BE FOR
DVLPG IFR DURING THE MRNG PUSH...WHICH SHUD PERSIST FOR MUCH OF
THE DAY THU.
MAINLY VFR EXPCTD FRI-FRI NGT. GUSTY WLY FLOW 10-20 KT G 25 KT.
VFR CONDITIONS EXPECTED OVER THE WEEKEND AS HIGH PRESSURE BUILDS TO
OUR SOUTH. GUSTY WESTERLY WINDS UP TO 15-20 KNOTS POSSIBLE THROUGH
SATURDAY AFTERNOON IN THE MODERATE CAA.
&&
.MARINE...
WINDS MAINLY AOB 10 KT THROUGH THU EVE. THE PRIMARY DIRECTION WL
BE SELY THRU THE DAY THU...ALTHO THAT WL FLUCTUATE AT TIMES.
STRONG COLD AIR ADVECTION/PRESSURE SURGE BEHIND A DEPARTING COLD
FRONT WILL BRING WINDS UP WELL INTO SMALL CRAFT ADVISORY RANGE BY
LATER FRIDAY...PERSISTING THROUGH FRIDAY NIGHT. WINDS COULD
POSSIBLY APPROACH GALE FORCE BY SATURDAY MORNING.
SCA WINDS CONTINUE INTO SATURDAY...WITH SOME GALES POSSIBLE...BEFORE
SUBSIDING LATE SATURDAY. WINDS REMAIN BELOW SCA THROUGH REMAINDER OF
THE WEEKEND.
&&
.CLIMATE...
THE FIRST HALF OF DECEMBER HAS BEEN VERY MILD ACROSS OUR AREA.
BELOW IS A LIST OF WHERE WE RANK FOR THE WARMEST FIRST HALF OF
DECEMBER ON RECORD AT OUR THREE MAIN CLIMATE SITES.
DCA
1. 52.7 (2001)
2. 51.9 (1998)
3. 50.4 (2015)
BWI
1. 49.6 (2001)
2. 48.7 (1998)
3. 47.9 (2015)
IAD
1. 48.5 (2001)
2. 48.4 (1998)
3. 47.1 (2015)
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DFH
NEAR TERM...HTS/LFR
SHORT TERM...DFH
LONG TERM...MSE
AVIATION...HTS/DFH/MSE
MARINE...HTS/LFR/DFH/MSE
CLIMATE...DFH
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
655 PM EST WED DEC 16 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 357 PM EST WED DEC 16 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE PLAINS INTO THE WRN LAKES. A VIGOROUS SHORTWAVE LIFTING
THROUGH NW WI SUPPORTED A BAND OF SHOWERS NEAR THE WI BORDER INTO
ERN WI. INSTABILITY ASSOCIATED WITH THIS FEATURE WAS GREAT ENOUGH TO
SUPPORT SOME ISOLD TSRA. AT THE SFC...A 991 MB LOW OVER FAR NW WI
WITH AN OCCLUDED FRONT INTO CNTRL WI WAS LIFTING TO THE NORTHEAST.
TEMPS REMAINED IN THE MID 30S WITH MAINLY LIGHT RAIN BEHIND THE
FRONT OVER WRN WI. COLDER AIR WITH PCPN CHANGING TO SNOW HAD MOVED
TO NEAR KMSP.
TONIGHT...EXPECT THE SCT SHOWERS TO LIFT INTO UPPER MI LATE THIS
AFTERNOON. A RUMBLE OF THUNDER MAY ALSO BE POSSIBLE OVER THE WEST.
AS THE LOW LIFTS TO THE NE...ENOUGH COLDER AIR WILL SWEEP IN FROM
THE SW TO CHANGE THE PCPN OVER TO SNOW THIS EVENING. OTHERWISE...WITH
ONLY WEAK UPWARD MOTION WITH THE WRAP-AROUND MOISTURE MOVING
IN...ONLY CHANCE POPS WERE MENTIONED OVER THE WEST. AS WINDS VEER
FROM THE SW TO WSW AFT 06Z AND 850 MB TEMPS DROP TO NEAR -10C...LOW
LEVEL CONV WILL BE MORE FAVORABLE FOR LES OR LAKE ENHANCED SNOW INTO
THE W AND N PORTIONS OF THE KEWEENAW PENINSUSLA WHERE SNOWFALL
AMOUNTS AROUND AN INCH ARE POSSIBLE.
THURSDAY...CONDITIONS WILL GRADUALLY BECOME MORE FAVORABLE FOR LES
ACROSS THE KEWEENAW AS 850 MB TEMPS DROP TO AROUND -12C WITH THE
CONVECTIVE CLOUD LAYER IN THE DGZ. WHILE THERE IS STILL SOME
UNCERTAINTY ON WHERE THE STRONGEST LOW LEVEL CONV WILL
DEVELOP...EXPECT INCREASING LES COULD BRING 1 TO 3 INCHES. TO MAINLY
THE NRN KEWEENAW. OTHWERWISE...TEMPS WILL DROP BACK CLOSER TO NORMAL
WITH HIGHS FROM THE MID 20S WEST TO THE LOW 30S EAST.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 506 PM EST WED DEC 16 2015
IT/S A RETURN TO WINTER...WELL AT LEAST FOR THE KEWEENAW. A LAKE
EFFECT SNOW WATCH REMAINS IN EFFECT FOR THE KEWEENAW PENINSULA
THURSDAY NIGHT THROUGH FRIDAY EVENING...AS WE HAVE PROLONGED W-NW
WINDS AND PLENTY OF MOISTURE STUCK IN THE DGZ...AND 850MB TEMPS OF -
13 TO -17C. TAKING A LOOK AT THE OVERALL PATTERN...A 500MB LOW
SPINNING ACROSS MANITOBA AND THE W HALF OF ONTARIO AT 00Z FRIDAY
WILL HAVE A TROUGH EXTENDED ALL THE WAY THROUGH TX. EXPECT THIS LOW
TO SHIFT OVER JAMES BAY FRIDAY AFTERNOON AS THE TROUGH PUSHES ACROSS
THE GREAT LAKES STATES. LOOK FOR RIDGING TO BEGIN ALOFT ON SATURDAY
AS THE LOW EXITS ACROSS QUEBEC. A PROLONGED RIDGE WILL THEN STAY
ACROSS THE UPPER GREAT LAKES THROUGH SUNDAY.
WEAKER FEATURES WILL PUSH IN FOR THE START OF THE WORK WEEK...WITH A
BROAD BUT MAINLY FLAT TROUGH SET UP ACROSS MUCH OF THE NATION. THE
TROUGH WILL DEEPEN MONDAY NIGHT THROUGH WEDNESDAY...WITH SW FLOW
OVER OUR AREA.
AS FOR THE SFC FEATURES...THE SFC LOW OVER NE MN WILL BE OVER JAMES
BAY AT 00Z FRIDAY AND WILL STAY NEARLY IN PLACE THROUGH SATURDAY.
THIS WILL BE WHEN A SECONDARY LOW RIDING UP THE COLD FRONT OVER THE
ATLANTIC COAST DEEPENS OVER NE CANADA. MOISTURE QUICKLY DIMINISHES
AND INVERSION HEIGHTS LOWER DURING THE DAY SATURDAY AS A RIDGE
TEMPORARILY BUILDS IN. THE NEXT LOW OVER THE CENTRAL PLAINS SUNDAY
MORNING HAS SOME TIMING ISSUES TO RESOLVE...BUT LOOKS TO MOVE ACROSS
THE UPPER GREAT LAKES SOMETIME BETWEEN SUNDAY NIGHT AND MONDAY
EVENING. KEPT POPS IN THE CHANCE RANGE FOR NOW...WITH MAINLY SNOW
EXPECTED EXCEPT NEAR LAKE MI WHERE RAIN MAY MIX IN FROM TIME TO
TIME. THIS OF COURSE WILL GREATLY DEPEND ON THE TRACK. LOOK FOR A
RETURN OF ABOVE NORMAL TEMPERATURES FOR SUNDAY AFTERNOON THROUGH MID
WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 655 PM EST WED DEC 16 2015
PASSAGE OF OCCLUDED FRONT EARLY THIS EVENING WILL BRING IMPROVING
CONDITIONS TO KCMX/KSAW. DOWNSLOPE NATURE OF THE WIND VEERING TO THE
SW SHOULD ALLOW MVFR CONDITIONS TO BECOME VFR AT TIMES. AT KCMX...
LIFR CONDITIONS WILL IMPROVE TO MVFR AT THE START OF THE FCST
PERIOD. AT KIWD...MVFR CONDITIONS SHOULD PREVAIL THIS EVENING AS LOW-
LEVEL MOISTURE AND SCT -SHSN WRAP INTO THE AREA BEHIND DEPARTING SFC
LOW LIFTING TO THE NE. PASSAGE OF SECONDARY SFC TROF SHOULD BRING A
PERIOD OF IFR CONDITIONS TO KIWD AND ESPECIALLY TO KCMX OVERNIGHT
WHERE WINDS WILL INCREASE NOTABLY WITH GUSTS TO NEAR 35KT. MVFR
CONDITIONS/GUSTY WINDS SHOULD THEN BE THE RULE AT KIWD/KCMX LATE
TONIGHT THRU THU. WHILE SOME -SHSN MAY AFFECT KIWD...WESTERLY WIND
DIRECTION WILL FAVOR KCMX FOR INCREASING LAKE EFFECT SNOW SHOWER
INTENSITY DURING THE DAY...EVENTUALLY LEADING TO IFR OR PERHAPS
LOWER CONDITIONS LATE IN THE FCST PERIOD. AT KSAW...MVFR/OCNL VFR
CONDITIONS WILL PREVAIL UNDER A DOWNSLOPE WESTERLY WIND.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 357 PM EST WED DEC 16 2015
WINDS WILL QUICKLY SHIFT TO THE SOUTHWEST THIS EVENING AS LOW
PRESSURE OVER NW WI LIFTS TO THE NORTHEAST OF THE AREA. EXPECT
ANOTHER PERIOD OF GALES TO 35KTS OVER AT LEAST THE SOUTHWESTERN HALF
OF LAKE SUPERIOR TONIGHT INTO THURSDAY MORNING. AS THE LOW BECOMES
NEARLY STATIONARY OVER SOUTHERN HUDSON BAY...EXPECT WESTERLY WINDS
OF 25-35KTS TO PERSIST THURSDAY AFTERNOON INTO FRIDAY BEFORE
DIMINISHING DUE TO AN APPROACHING RIDGE. THIS RIDGE WILL QUICKLY
MOVE ACROSS THE UPPER GREAT LAKES REGION ON SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM THURSDAY EVENING THROUGH LATE FRIDAY
NIGHT FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 9 PM EST THIS EVENING FOR LSZ251-267.
GALE WARNING UNTIL 1 AM EST FRIDAY FOR LSZ244-245-263>266.
GALE WARNING FROM 11 PM EST /10 PM CST/ THIS EVENING TO 1 AM EST
/MIDNIGHT CST/ FRIDAY FOR LSZ162-240>243.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
539 PM EST TUE DEC 15 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 430 PM EST TUE DEC 15 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A HIGH AMPLITUDE PATTERN WITHA
A TROUGH IN THE WRN CONUS THROUGH THE ROCKIES INTO THE PLAINS AND A
RIDGE FROM THE SE INTO THE GREAT LAKES. THE MAIN UPSTREAM FEATURE IS
THE MID LEVEL LOW OVER SW NEBRASKA. AT THE SFC...ERLY FLOW PREVAILED
BTWN HIGH PRES OVER NRN ONTARIO AND THE SFC LOW OVER NW KS. DRIER
AIR FROM EAST OF LAKE SUPERIOR HAS HELPED SCOUR OUT THE LOWER CLOUDS
OVER THE ERN CWA AND HAS HELPED BRING AN END TO THE UPSLOPE LES INTO
N CNTRL UPPER MI.
TONIGHT...AS THE CNTRL PLAINS LOW LIFTS NE TO NEAR NW IA...SE LOW
LEVEL FLOW WILL INCREASE ACROSS THE CWA. THE COMBINATION OF 285K-
290K ISENTROPIC LIFT AND LOW LEVEL MOIST FLOW OFF OF LAKE MI WILL
SUPPORT INCREASING PCPN CHANCES LATE TONIGHT. WITH THE MOIST LAYER
EXTENDING ONLY TO AROUND -5C...MAINLY DZ/FZDZ IS EXPECTED. TEMPS
CLIMBING ABOVE FREEZING LATE TONIGHT SHOULD HELP MINIMIZE POTENTIAL
FOR FREEZING PCPN.
WEDNESDAY...AS THE MID LEVEL MOVES THROUGH CNTRL MN...A PERIOD OF
MODERATE TO STRONG 700-300 MB QVECTOR CONV WITH A BAND OF DEEPER
MOISTURE WILL SUPPORT LIKELY POPS ACROSS THROUGH THE AREA BTWN 15Z-
21Z. TEMPS IN THE ANTECDENT MID LEVEL DRY LAYER WILL DROP ENOUGH
WITH EVAPORATIVE COOLING TO SUPPORT SNOW. HOWEVER...EXPECT A DEEP
ENOUGH SFC WARM LAYER FOR MAINLY RAIN OVER MOST OF THE CWA EXCEPT
THE HIGHER TERRAIN IN THE WEST HALF. EVEN WITH QPF IN THE 0.15 TO
0.25 INCH RANGE...THE WARM SFC CONDITIONS IN THE MID 30S SHOULD
LIMIT ANY ACCUMULATIONS TO LESS THAN AN INCH. THE PCPN MAY REVERT
BACK TO DRIZZLE AS THE DEEPER MOISTURE MOVES OUT FROM WEST TO EAST
LATER IN THE AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 539 PM EST TUE DEC 15 2015
AT 00Z THU...A ROUGHLY 990MB SFC LOW AND CO-LOCATED UPPER LOW WILL
BE OVER WRN LAKE SUPERIOR OR JUST NW OF THE CWA. COLD AIR WILL BE
ADVECTING INTO THE AREA FROM THE SW...WITH 850MB TEMPS NEAR OR BELOW
0C BY 00Z THU AND WELL UNDER 0C BY 06Z THU. THE DRY SLOT WILL KEEP
SIGNIFICANT SNOWFALL AMOUNTS FROM OCCURING WED NIGHT...BUT WILL SEE
AN INCREASE IN LES IN WSW-W WIND SNOWBELTS LATE WED NIGHT THROUGH
THU...BECOMING LIKELY BY THU AFTERNOON AS 850MB TEMPS DROP BELOW
-10C. LES WILL PEAK THU NIGHT INTO FRI AS AN UPPER TROUGH MOVES
THROUGH AND 850MB TEMPS DROP TO AOB -15C. THIS WILL LEAD TO
INVERSION HEIGHTS AROUND 9-10KFT AND LIFT FAVORABLY LOCATED IN THE
DGZ...PROMOTING MODERATE TO POTENTIALLY HEAVY LES. LOW LEVEL WIND
DIRECTIONS REMAIN IN QUESTION...WITH MODEL SOLUTIONS BETWEEN WSW AND
WNW...WHICH MAKES LES POTENTIAL UNCERTAIN FOR EASTERN LES AREAS OF
ERN ALGER...NRN SCHOOLCRAFT AND LUCE COUNTIES. ALL MODELS DO SHOW
WINDS TURNING WNW-NW BY LATE FRI EVENING AND LASTING THROUGH MUCH OF
SAT BEFORE A SFC RIDGE MOVES THROUGH. STILL SEEMS THAT 1-2 SNOWFALL
AMOUNTS OF 8 PLUS INCHES IS LIKELY OVER THE W WIND SNOWBELTS. WILL
LIKELY NEED AN ADVISORY FOR THE KEWEENAW PENINSULA AREA AND WILL
CONTINUE TO HIGHLIGHT THE POTENTIAL FOR PLOW-ABLE SNOW IN THE HWO.
THE SNOW IS EXPECTED TO DIMINISH LATE SAT INTO SAT NIGHT AS DRY AIR
WITH A SURFACE RIDGE MOVES INTO THE AREA.
TEMPS LOOK TO WARM AGAIN EARLY TO MIDDLE OF NEXT WEEK...BUT WILL LET
CONSENSUS GUIDANCE POPULATE THAT PORTION OF THE FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 101 PM EST TUE DEC 15 2015
AS WINDS VEER FROM NE TO E AND DRIER AIR MOVES IN FROM TH
EAST...EXPECT THE LIGHT UPSLOPE/LES SNOW SHOWERS AT SAW TO DIMINISH
AND END THIS AFTERNOON WITH MAINLY MVFR CIGS. ERLY FLOW WILL ALSO
FAVOR LOW END MVFR CIGS AT CMX AND IWD. ANOTHER LOW PRESSURE
APPROACHING FROM THE CENTRAL PLAINS WILL BRING A CHANCE FOR SOME MORE
LIGHT SNOW OR PATCHY FREEZING DRIZZLE LATE TONIGHT AS CONDITIONS
LOWER TOWARD IFR ONCE MORE. A PERIOD OF RAIN AND SNOW IS ALSO
EXPECTED BY LATE MORNING. SE WINDS WILL SUPPORT LIFR CIGS AT SAW WITH
THE PCPN AND SOME FOG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 PM EST TUE DEC 15 2015
ANOTHER LOW PRESSURE SYSTEM WILL DEVELOP AND SLIDE THROUGH THE UPPER
GREAT LAKES WEDNESDAY INTO THURSDAY. NORTHEAST GALES ARE EXPECTED
OVER THE WEST HALF THIS EVENING INTO WED MORNING AND SOUTHEAST WINDS
WILL REACH GALE FORCE OVER THE CENTRAL AND EASTERN LAKE AHEAD OF THE
LOW LATE TONIGHT THROUGH WEDNESDAY FOLLOWED BY WESTERLY WINDS
APPROACHING GALES IN THE COLD ADVECTION BEHIND THE LOW ON THURSDAY
INTO FRIDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 7 AM TO 9 PM EST WEDNESDAY FOR LSZ267.
GALE WARNING FROM 4 AM TO 6 PM EST WEDNESDAY FOR LSZ263>266.
GALE WARNING UNTIL 9 AM EST /8 AM CST/ WEDNESDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
430 PM EST TUE DEC 15 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 430 PM EST TUE DEC 15 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A HIGH AMPLITUDE PATTERN WITHA
A TROUGH IN THE WRN CONUS THROUGH THE ROCKIES INTO THE PLAINS AND A
RIDGE FROM THE SE INTO THE GREAT LAKES. THE MAIN UPSTREAM FEATURE IS
THE MID LEVEL LOW OVER SW NEBRASKA. AT THE SFC...ERLY FLOW PREVAILED
BTWN HIGH PRES OVER NRN ONTARIO AND THE SFC LOW OVER NW KS. DRIER
AIR FROM EAST OF LAKE SUPERIOR HAS HELPED SCOUR OUT THE LOWER CLOUDS
OVER THE ERN CWA AND HAS HELPED BRING AN END TO THE UPSLOPE LES INTO
N CNTRL UPPER MI.
TONIGHT...AS THE CNTRL PLAINS LOW LIFTS NE TO NEAR NW IA...SE LOW
LEVEL FLOW WILL INCREASE ACROSS THE CWA. THE COMBINATION OF 285K-
290K ISENTROPIC LIFT AND LOW LEVEL MOIST FLOW OFF OF LAKE MI WILL
SUPPORT INCREASING PCPN CHANCES LATE TONIGHT. WITH THE MOIST LAYER
EXTENDING ONLY TO AROUND -5C...MAINLY DZ/FZDZ IS EXPECTED. TEMPS
CLIMBING ABOVE FREEZING LATE TONIGHT SHOULD HELP MINIMIZE POTENTIAL
FOR FREEZING PCPN.
WEDNESDAY...AS THE MID LEVEL MOVES THROUGH CNTRL MN...A PERIOD OF
MODERATE TO STRONG 700-300 MB QVECTOR CONV WITH A BAND OF DEEPER
MOISTURE WILL SUPPORT LIKELY POPS ACROSS THROUGH THE AREA BTWN 15Z-
21Z. TEMPS IN THE ANTECDENT MID LEVEL DRY LAYER WILL DROP ENOUGH
WITH EVAPORATIVE COOLING TO SUPPORT SNOW. HOWEVER...EXPECT A DEEP
ENOUGH SFC WARM LAYER FOR MAINLY RAIN OVER MOST OF THE CWA EXCEPT
THE HIGHER TERRAIN IN THE WEST HALF. EVEN WITH QPF IN THE 0.15 TO
0.25 INCH RANGE...THE WARM SFC CONDITIONS IN THE MID 30S SHOULD
LIMIT ANY ACCUMULATIONS TO LESS THAN AN INCH. THE PCPN MAY REVERT
BACK TO DRIZZLE AS THE DEEPER MOISTURE MOVES OUT FROM WEST TO EAST
LATER IN THE AFTERNOON.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 358 AM EST TUE DEC 15 2015
A FAIRLY ACTIVE LONG TERM FORECAST IS EXPECT ACROSS THE UPPER GREAT
LAKES REGION AS ANOTHER LOW PRESSURE SYSTEM WILL LIFT NORTHEAST
THROUGH THE WESTERN GREAT LAKES REGION WEDNESDAY INTO WEDNESDAY
NIGHT. MUCH COLDER AIR WILL ARRIVE BEHIND THE LOW AND LEAD TO A
PERIOD OF LAKE EFFECT SNOW AS THE LOW BECOMES STATIONARY OVER FAR
NORTHERN ONTARIO THURSDAY NIGHT AND REMAINS THERE INTO SATURDAY.
HIGH PRESSURE WILL FINALLY BUILD OVER THE REGION FOR THE SECOND
HALF OF THE WEEKEND BEFORE ANOTHER LOW MOVES THROUGH THE REGION
DURING THE MONDAY/TUESDAY TIME FRAME.
THE INITIAL LOW (UPPER WAVE CURRENTLY OVER THE SOUTHWESTERN CONUS)
WILL BE LOCATED OVER SOUTHERN MINNESOTA WEDNESDAY MORNING AND WILL
LIFT NORTH-NORTHEAST ACROSS FAR WESTERN LAKE SUPERIOR WEDNESDAY
EVENING. COOL SOUTHEASTERLY FLOW WILL BE IN PLACE AHEAD OF THE LOW
EARLY WEDNESDAY MORNING AND WILL LIKELY LEAD TO ABUNDANT LOW
CLOUDS...FOG...AND SOME DRIZZLE OVER MUCH OF THE CWA (ALTHOUGH THE
DOWNSLOPING WINDS OVER THE FAR WEST WILL LIKELY LIMIT THE COVERAGE
SOME). THE INITIAL PUSH OF PRECIPITATION SHOULD BE CROSSING THE
WISCONSIN BORDER AT THE START OF THE PERIOD AND LIFT NORTH-NORTHEAST
ACROSS THE REST OF THE AREA THROUGH THE DAY. EXPECT THE BEST FORCING
AND DEEP MOISTURE TO OCCUR OVER THE WESTERN THIRD TO HALF OF THE
U.P. FIRST WITH THE INITIAL WAVE WEDNESDAY MORNING AND AGAIN WITH
THE MID-LEVEL LOW MOVING THROUGH LATE WEDNESDAY AFTERNOON INTO
WEDNESDAY EVENING. WITH THAT BEING SAID...THERE DOES APPEAR TO BE
ENOUGH 925-700MB FORCING TO SUPPORT A WAVE OF STRONGER PRECIPITATION
TO MOVE THROUGH THE CENTRAL AND EASTERN HALF OF THE CWA THROUGH THE
DAY ON WEDNESDAY. THAT FORCING SHOULD BE ENOUGH TO GENERATE
0.15-0.25IN OF QPF AND THE CONCERN FALLS TO P-TYPE. MODELS STILL
VARYING IN THE THERMAL PROFILE...WHICH LEADS TO LOW CONFIDENCE ON
THE EXACT PRECIP. THERE IS A NOSE OF WARM AIR ALOFT WITH THE
INITIAL PRECIP...BUT EVAPORATIVE COOLING SHOULD LOWER TEMPERATURES
IN THE MID LEVELS TOWARDS THE WETBULB...WHICH IS BELOW ZERO.
THUS...EXPECT A PERIOD OF SNOW BEFORE THE DEEPER MOISTURE CUTS OUT
AND TRANSITIONS THE PRECIP TO DRIZZLE OR RAIN (ALSO AS THE LOW
LEVELS WARM). OVER THE EAST...DID INCLUDE SOME SNOW DURING THE
MORNING...BUT CHANCES ARE LOW AND EXPECT PRIMARILY RAIN. WITH
THE BRIEF PERIOD OF DRYING ALOFT...FOR A COUPLE HOURS DURING MID
DAY...THAT WILL LIKELY TRANSITION THINGS TO MORE OF A DRIZZLE AWAY
FROM THE STRONGER PRECIP. WILL CONTINUE TO SHOW PRECIPITATION
CHANCES DIMINISHING THROUGH THE EVENING EXCEPT OVER THE FAR WEST
CLOSEST TO THE MID LEVEL LOW MOVING THROUGH.
BEHIND THE LOW...A TRAILING TROUGH WILL INITIALLY BE OVER NORTHERN
LAKE SUPERIOR BEFORE SHIFTING EAST THROUGH THE DAY ON THURSDAY.
THIS WILL USHER IN MUCH COLDER AIR OVER THE REGION...850MB TEMPS
FALLING FROM -5C AT 06Z THURSDAY TO -15C BY 06Z FRIDAY. THAT COLD
AIR AND ABUNDANT LOW LEVEL MOISTURE WILL LEAD TO LAKE EFFECT FOR
AREAS FAVORED BY WESTERLY WINDS. WILL SHOW POPS INCREASING THROUGH
THE DAY THURSDAY FOR THE WESTERLY WINDS FAVORED AREAS OF THE
WESTERN U.P. AND ESPECIALLY THE KEWEENAW PENINSULA. OVER THE
EAST...WINDS LOOK TO TAKE A LITTLE LONGER TO TURN WESTERLY OR
SLIGHT WEST-NORTHWEST AND WILL HAVE POPS INCREASING LATER THERE.
THERE IS STILL SOME DIFFERENCES IN THE LOW LEVEL WINDS FOR AREAS
OVER THE EAST THURSDAY NIGHT INTO FRIDAY...WHETHER THEY WILL BE
WEST-SOUTHWEST OR WEST-NORTHWEST...SO CONFIDENCE IS ON THE LOW SIDE
FOR THE LAKE EFFECT FOR EASTERN ALGER AND NORTHERN LUCE COUNTY
UNTIL THE WINDS TURN MORE FAVORABLE FRIDAY NIGHT. BUT OVER THE
WEST...THE FAVORABLE WESTERLY WINDS...INVERSION HEIGHTS AROUND
9-10KFT AND A BULK OF THE FORCING WITHIN THE DGZ WOULD SUPPORT
MODERATE LAKE EFFECT SNOW LATER THURSDAY AND ESPECIALLY THURSDAY
NIGHT INTO FRIDAY EVENING. WILL FOCUS THE HIGHEST POPS (DEFINITE)
FROM THE KEWEENAW THROUGH NORTHERN ONTONAGON COUNTY AND MATCH THAT
AREA WITH THE GREATEST SNOWFALL AMOUNTS. IT IS STILL A LITTLE WAYS
OUT...BUT THE INITIAL FORECAST HAS MUCH NEEDED 1-2 DAY SNOWFALL
AMOUNTS OF 6 PLUS INCHES. WILL LIKELY NEED AN ADVISORY FOR THE
KEWEENAW PENINSULA AREA AND WILL CONTINUE TO HIGHLIGHT THE POTENTIAL
FOR PLOW-ABLE SNOW IN THE HWO. THE SNOW IS EXPECTED TO DIMINISH
SATURDAY NIGHT AS DRY AIR WITH A SURFACE RIDGE MOVES INTO THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 101 PM EST TUE DEC 15 2015
AS WINDS VEER FROM NE TO E AND DRIER AIR MOVES IN FROM TH
EAST...EXPECT THE LIGHT UPSLOPE/LES SNOW SHOWERS AT SAW TO DIMINISH
AND END THIS AFTERNOON WITH MAINLY MVFR CIGS. ERLY FLOW WILL ALSO
FAVOR LOW END MVFR CIGS AT CMX AND IWD. ANOTHER LOW PRESSURE
APPROACHING FROM THE CENTRAL PLAINS WILL BRING A CHANCE FOR SOME MORE
LIGHT SNOW OR PATCHY FREEZING DRIZZLE LATE TONIGHT AS CONDITIONS
LOWER TOWARD IFR ONCE MORE. A PERIOD OF RAIN AND SNOW IS ALSO
EXPECTED BY LATE MORNING. SE WINDS WILL SUPPORT LIFR CIGS AT SAW WITH
THE PCPN AND SOME FOG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 PM EST TUE DEC 15 2015
ANOTHER LOW PRESSURE SYSTEM WILL DEVELOP AND SLIDE THROUGH THE UPPER
GREAT LAKES WEDNESDAY INTO THURSDAY. NORTHEAST GALES ARE EXPECTED
OVER THE WEST HALF THIS EVENING INTO WED MORNING AND SOUTHEAST WINDS
WILL REACH GALE FORCE OVER THE CENTRAL AND EASTERN LAKE AHEAD OF THE
LOW LATE TONIGHT THROUGH WEDNESDAY FOLLOWED BY WESTERLY WINDS
APPROACHING GALES IN THE COLD ADVECTION BEHIND THE LOW ON THURSDAY
INTO FRIDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 7 AM TO 9 PM EST WEDNESDAY FOR LSZ267.
GALE WARNING FROM 4 AM TO 6 PM EST WEDNESDAY FOR LSZ263>266.
GALE WARNING UNTIL 9 AM EST /8 AM CST/ WEDNESDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
103 PM EST TUE DEC 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 529 AM EST TUE DEC 15 2015
WATER VAPOR LOOP AND RAP ANALYSIS SHOWS CLOSED LOW OVER SE ONTARIO
WITHIN MID-UPPER TROUGH. SOME MOISTURE WRAPPING BACK AROUND THE LOW
INTO THE UPPER GREAT LAKES IS HELPING TO SUSTAIN SOME UPSLOPE
ENHANCED LAKE EFFECT SNOW SHOWERS OVER NORTH CENTRAL UPPER MI IN
WEAKLY CYCLONIC NORTHERLY FLOW. MOISTURE BARELY REACHING TO -9/-10C
HAS RESULTED IN SMALL FLAKE SIZE EARLY THIS MORNING WHICH HAS
GENERALLY LIMITED ADDITIONAL ACCUMULATION TO AN INCH OR LESS MOST
PLACES...ALTHOUGH SMALLER FLAKE SIZE IS CONTRIBUTING TO BIT MORE
BLOWING OF SNOW NEAR LAKE SUPERIOR AS NORTH WINDS ARE STILL GUSTING
TO 25 TO 30 MPH. FARTHER UPSTREAM TO THE WEST...A MID-UPPER LEVEL
RIDGE IS OVER THE PLAINS WITH A BROAD TROUGH OVER THE ROCKIES AND A
CLOSED LOW OVER EASTERN CO.
TODAY...A MUCH QUIETER WEATHER DAY IS EXPECTED ACROSS THE U.P.
SURFACE LOW OVER SOUTHERN QUEBEC WILL CONTINUE TO MOVE EAST THROUGH
THE DAY AS SFC HIGH PRESSURE AND UPPER LEVEL RIDGING BUILD IN FROM
THE PLAINS. THIS RIDGING WILL ALLOW FOR DRIER CONDITIONS ACROSS
UPPER MICHIGAN...HOWEVER...CLOUD COVER WILL LINGER THROUGH THE DAY
AS LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE LOWERING SUBSIDENCE
INVERSION. LOWERING INVERSION HEIGHT WITH INCREASINGLY
ANTICYCLONIC/DIVERGENT FLOW FROM BUILDING RIDGE SHOULD HELP END ANY
LINGERING LES OVER NORTH CENTRAL UPPER MI BY LATE MORNING/EARLY
AFTERNOON. UPSLOPE NE FLOW COULD STILL CONTRIBUTE TO FLURRIES/PATCHY
FZDZ INTO EARLY AFTERNOON. TEMPERATURES WILL BE MUCH COOLER THAN
YESTERDAY...ESPECIALLY OVER THE EAST HALF...WITH HIGHS RANGING FROM
LOWER 30S WEST TO MID 30S SOUTH CENTRAL AND EAST.
TONIGHT...RIDGING OVER THE AREA SHOULD CONTINUE QUIET WEATHER INTO
THE EVENING HOURS BUT THEN INCREASED MID-LVL Q-VECT CONV AND UPPER
DIFFLUENCE IN ADVANCE OF LOW PRESSURE SYSTEM LIFTING THROUGH THE
CENTRAL PLAINS WILL BRING AN INCREASED CHANCE OF PRECIPITATION
ESPECIALLY LATE TONIGHT. FAIRLY SHALLOW MOISTURE GENERALLY EXTENDING
NO HIGHER THAN 800 MB LEVEL MAY LIMIT MUCH OF THE PRECIPITATION
INITIALLY TONIGHT TO DRIZZLE OR FREEZING DRIZZLE AS MOISTURE WILL
REMAIN BLO THE DGZ. BEST CHANCE OF PRECIPITATION WILL BE THOSE
LOCATIONS FAVORED BY INCREASINGLY CYCLONIC UPSLOPE E-SE FLOW. MIN
TEMPS WILL GENERALLY RANGE FROM THE MID TO UPPER 20S INLAND TO THE
LOWER 30S NEAR THE GREAT LAKES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 358 AM EST TUE DEC 15 2015
A FAIRLY ACTIVE LONG TERM FORECAST IS EXPECT ACROSS THE UPPER GREAT
LAKES REGION AS ANOTHER LOW PRESSURE SYSTEM WILL LIFT NORTHEAST
THROUGH THE WESTERN GREAT LAKES REGION WEDNESDAY INTO WEDNESDAY
NIGHT. MUCH COLDER AIR WILL ARRIVE BEHIND THE LOW AND LEAD TO A
PERIOD OF LAKE EFFECT SNOW AS THE LOW BECOMES STATIONARY OVER FAR
NORTHERN ONTARIO THURSDAY NIGHT AND REMAINS THERE INTO SATURDAY.
HIGH PRESSURE WILL FINALLY BUILD OVER THE REGION FOR THE SECOND
HALF OF THE WEEKEND BEFORE ANOTHER LOW MOVES THROUGH THE REGION
DURING THE MONDAY/TUESDAY TIME FRAME.
THE INITIAL LOW (UPPER WAVE CURRENTLY OVER THE SOUTHWESTERN CONUS)
WILL BE LOCATED OVER SOUTHERN MINNESOTA WEDNESDAY MORNING AND WILL
LIFT NORTH-NORTHEAST ACROSS FAR WESTERN LAKE SUPERIOR WEDNESDAY
EVENING. COOL SOUTHEASTERLY FLOW WILL BE IN PLACE AHEAD OF THE LOW
EARLY WEDNESDAY MORNING AND WILL LIKELY LEAD TO ABUNDANT LOW
CLOUDS...FOG...AND SOME DRIZZLE OVER MUCH OF THE CWA (ALTHOUGH THE
DOWNSLOPING WINDS OVER THE FAR WEST WILL LIKELY LIMIT THE COVERAGE
SOME). THE INITIAL PUSH OF PRECIPITATION SHOULD BE CROSSING THE
WISCONSIN BORDER AT THE START OF THE PERIOD AND LIFT NORTH-NORTHEAST
ACROSS THE REST OF THE AREA THROUGH THE DAY. EXPECT THE BEST FORCING
AND DEEP MOISTURE TO OCCUR OVER THE WESTERN THIRD TO HALF OF THE
U.P. FIRST WITH THE INITIAL WAVE WEDNESDAY MORNING AND AGAIN WITH
THE MID-LEVEL LOW MOVING THROUGH LATE WEDNESDAY AFTERNOON INTO
WEDNESDAY EVENING. WITH THAT BEING SAID...THERE DOES APPEAR TO BE
ENOUGH 925-700MB FORCING TO SUPPORT A WAVE OF STRONGER PRECIPITATION
TO MOVE THROUGH THE CENTRAL AND EASTERN HALF OF THE CWA THROUGH THE
DAY ON WEDNESDAY. THAT FORCING SHOULD BE ENOUGH TO GENERATE
0.15-0.25IN OF QPF AND THE CONCERN FALLS TO P-TYPE. MODELS STILL
VARYING IN THE THERMAL PROFILE...WHICH LEADS TO LOW CONFIDENCE ON
THE EXACT PRECIP. THERE IS A NOSE OF WARM AIR ALOFT WITH THE
INITIAL PRECIP...BUT EVAPORATIVE COOLING SHOULD LOWER TEMPERATURES
IN THE MID LEVELS TOWARDS THE WETBULB...WHICH IS BELOW ZERO.
THUS...EXPECT A PERIOD OF SNOW BEFORE THE DEEPER MOISTURE CUTS OUT
AND TRANSITIONS THE PRECIP TO DRIZZLE OR RAIN (ALSO AS THE LOW
LEVELS WARM). OVER THE EAST...DID INCLUDE SOME SNOW DURING THE
MORNING...BUT CHANCES ARE LOW AND EXPECT PRIMARILY RAIN. WITH
THE BRIEF PERIOD OF DRYING ALOFT...FOR A COUPLE HOURS DURING MID
DAY...THAT WILL LIKELY TRANSITION THINGS TO MORE OF A DRIZZLE AWAY
FROM THE STRONGER PRECIP. WILL CONTINUE TO SHOW PRECIPITATION
CHANCES DIMINISHING THROUGH THE EVENING EXCEPT OVER THE FAR WEST
CLOSEST TO THE MID LEVEL LOW MOVING THROUGH.
BEHIND THE LOW...A TRAILING TROUGH WILL INITIALLY BE OVER NORTHERN
LAKE SUPERIOR BEFORE SHIFTING EAST THROUGH THE DAY ON THURSDAY.
THIS WILL USHER IN MUCH COLDER AIR OVER THE REGION...850MB TEMPS
FALLING FROM -5C AT 06Z THURSDAY TO -15C BY 06Z FRIDAY. THAT COLD
AIR AND ABUNDANT LOW LEVEL MOISTURE WILL LEAD TO LAKE EFFECT FOR
AREAS FAVORED BY WESTERLY WINDS. WILL SHOW POPS INCREASING THROUGH
THE DAY THURSDAY FOR THE WESTERLY WINDS FAVORED AREAS OF THE
WESTERN U.P. AND ESPECIALLY THE KEWEENAW PENINSULA. OVER THE
EAST...WINDS LOOK TO TAKE A LITTLE LONGER TO TURN WESTERLY OR
SLIGHT WEST-NORTHWEST AND WILL HAVE POPS INCREASING LATER THERE.
THERE IS STILL SOME DIFFERENCES IN THE LOW LEVEL WINDS FOR AREAS
OVER THE EAST THURSDAY NIGHT INTO FRIDAY...WHETHER THEY WILL BE
WEST-SOUTHWEST OR WEST-NORTHWEST...SO CONFIDENCE IS ON THE LOW SIDE
FOR THE LAKE EFFECT FOR EASTERN ALGER AND NORTHERN LUCE COUNTY
UNTIL THE WINDS TURN MORE FAVORABLE FRIDAY NIGHT. BUT OVER THE
WEST...THE FAVORABLE WESTERLY WINDS...INVERSION HEIGHTS AROUND
9-10KFT AND A BULK OF THE FORCING WITHIN THE DGZ WOULD SUPPORT
MODERATE LAKE EFFECT SNOW LATER THURSDAY AND ESPECIALLY THURSDAY
NIGHT INTO FRIDAY EVENING. WILL FOCUS THE HIGHEST POPS (DEFINITE)
FROM THE KEWEENAW THROUGH NORTHERN ONTONAGON COUNTY AND MATCH THAT
AREA WITH THE GREATEST SNOWFALL AMOUNTS. IT IS STILL A LITTLE WAYS
OUT...BUT THE INITIAL FORECAST HAS MUCH NEEDED 1-2 DAY SNOWFALL
AMOUNTS OF 6 PLUS INCHES. WILL LIKELY NEED AN ADVISORY FOR THE
KEWEENAW PENINSULA AREA AND WILL CONTINUE TO HIGHLIGHT THE POTENTIAL
FOR PLOW-ABLE SNOW IN THE HWO. THE SNOW IS EXPECTED TO DIMINISH
SATURDAY NIGHT AS DRY AIR WITH A SURFACE RIDGE MOVES INTO THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 101 PM EST TUE DEC 15 2015
AS WINDS VEER FROM NE TO E AND DRIER AIR MOVES IN FROM TH
EAST...EXPECT THE LIGHT UPSLOPE/LES SNOW SHOWERS AT SAW TO DIMINISH
AND END THIS AFTERNOON WITH MAINLY MVFR CIGS. ERLY FLOW WILL ALSO
FAVOR LOW END MVFR CIGS AT CMX AND IWD. ANOTHER LOW PRESSURE
APPROACHING FROM THE CENTRAL PLAINS WILL BRING A CHANCE FOR SOME MORE
LIGHT SNOW OR PATCHY FREEZING DRIZZLE LATE TONIGHT AS CONDITIONS
LOWER TOWARD IFR ONCE MORE. A PERIOD OF RAIN AND SNOW IS ALSO
EXPECTED BY LATE MORNING. SE WINDS WILL SUPPORT LIFR CIGS AT SAW WITH
THE PCPN AND SOME FOG.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 529 AM EST TUE DEC 15 2015
N-NE WINDS WILL SUBSIDE TEMPORARILY ON THIS MORNING AS GRADIENT
WEAKENS BEFORE ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND SLIDES
THROUGH THE UPPER GREAT LAKES WEDNESDAY INTO THURSDAY. NORTHEAST
WINDS WILL INCREASE TO GALES OVER THE WEST HALF THIS EVENING INTO
WED MORNING AND SOUTHEAST WINDS SHOULD REACH GALE FORCE OVER THE
CENTRAL AND EASTERN LAKE AHEAD OF THE LOW LATE TONIGHT THROUGH
WEDNESDAY FOLLOWED BY WESTERLY WINDS APPROACHING GALES IN THE COLD
ADVECTION BEHIND THE LOW ON THURSDAY INTO FRIDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM 7 AM TO 9 PM EST WEDNESDAY FOR LSZ267.
GALE WARNING FROM 4 AM TO 6 PM EST WEDNESDAY FOR LSZ263>266.
GALE WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 9 AM EST
/8 AM CST/ WEDNESDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
626 AM EST TUE DEC 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 529 AM EST TUE DEC 15 2015
WATER VAPOR LOOP AND RAP ANALYSIS SHOWS CLOSED LOW OVER SE ONTARIO
WITHIN MID-UPPER TROUGH. SOME MOISTURE WRAPPING BACK AROUND THE LOW
INTO THE UPPER GREAT LAKES IS HELPING TO SUSTAIN SOME UPSLOPE
ENHANCED LAKE EFFECT SNOW SHOWERS OVER NORTH CENTRAL UPPER MI IN
WEAKLY CYCLONIC NORTHERLY FLOW. MOISTURE BARELY REACHING TO -9/-10C
HAS RESULTED IN SMALL FLAKE SIZE EARLY THIS MORNING WHICH HAS
GENERALLY LIMITED ADDITIONAL ACCUMULATION TO AN INCH OR LESS MOST
PLACES...ALTHOUGH SMALLER FLAKE SIZE IS CONTRIBUTING TO BIT MORE
BLOWING OF SNOW NEAR LAKE SUPERIOR AS NORTH WINDS ARE STILL GUSTING
TO 25 TO 30 MPH. FARTHER UPSTREAM TO THE WEST...A MID-UPPER LEVEL
RIDGE IS OVER THE PLAINS WITH A BROAD TROUGH OVER THE ROCKIES AND A
CLOSED LOW OVER EASTERN CO.
TODAY...A MUCH QUIETER WEATHER DAY IS EXPECTED ACROSS THE U.P.
SURFACE LOW OVER SOUTHERN QUEBEC WILL CONTINUE TO MOVE EAST THROUGH
THE DAY AS SFC HIGH PRESSURE AND UPPER LEVEL RIDGING BUILD IN FROM
THE PLAINS. THIS RIDGING WILL ALLOW FOR DRIER CONDITIONS ACROSS
UPPER MICHIGAN...HOWEVER...CLOUD COVER WILL LINGER THROUGH THE DAY
AS LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE LOWERING SUBSIDENCE
INVERSION. LOWERING INVERSION HEIGHT WITH INCREASINGLY
ANTICYCLONIC/DIVERGENT FLOW FROM BUILDING RIDGE SHOULD HELP END ANY
LINGERING LES OVER NORTH CENTRAL UPPER MI BY LATE MORNING/EARLY
AFTERNOON. UPSLOPE NE FLOW COULD STILL CONTRIBUTE TO FLURRIES/PATCHY
FZDZ INTO EARLY AFTERNOON. TEMPERATURES WILL BE MUCH COOLER THAN
YESTERDAY...ESPECIALLY OVER THE EAST HALF...WITH HIGHS RANGING FROM
LOWER 30S WEST TO MID 30S SOUTH CENTRAL AND EAST.
TONIGHT...RIDGING OVER THE AREA SHOULD CONTINUE QUIET WEATHER INTO
THE EVENING HOURS BUT THEN INCREASED MID-LVL Q-VECT CONV AND UPPER
DIFFLUENCE IN ADVANCE OF LOW PRESSURE SYSTEM LIFTING THROUGH THE
CENTRAL PLAINS WILL BRING AN INCREASED CHANCE OF PRECIPITATION
ESPECIALLY LATE TONIGHT. FAIRLY SHALLOW MOISTURE GENERALLY EXTENDING
NO HIGHER THAN 800 MB LEVEL MAY LIMIT MUCH OF THE PRECIPITATION
INITIALLY TONIGHT TO DRIZZLE OR FREEZING DRIZZLE AS MOISTURE WILL
REMAIN BLO THE DGZ. BEST CHANCE OF PRECIPITATION WILL BE THOSE
LOCATIONS FAVORED BY INCREASINGLY CYCLONIC UPSLOPE E-SE FLOW. MIN
TEMPS WILL GENERALLY RANGE FROM THE MID TO UPPER 20S INLAND TO THE
LOWER 30S NEAR THE GREAT LAKES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 358 AM EST TUE DEC 15 2015
A FAIRLY ACTIVE LONG TERM FORECAST IS EXPECT ACROSS THE UPPER GREAT
LAKES REGION AS ANOTHER LOW PRESSURE SYSTEM WILL LIFT NORTHEAST
THROUGH THE WESTERN GREAT LAKES REGION WEDNESDAY INTO WEDNESDAY
NIGHT. MUCH COLDER AIR WILL ARRIVE BEHIND THE LOW AND LEAD TO A
PERIOD OF LAKE EFFECT SNOW AS THE LOW BECOMES STATIONARY OVER FAR
NORTHERN ONTARIO THURSDAY NIGHT AND REMAINS THERE INTO SATURDAY.
HIGH PRESSURE WILL FINALLY BUILD OVER THE REGION FOR THE SECOND
HALF OF THE WEEKEND BEFORE ANOTHER LOW MOVES THROUGH THE REGION
DURING THE MONDAY/TUESDAY TIME FRAME.
THE INITIAL LOW (UPPER WAVE CURRENTLY OVER THE SOUTHWESTERN CONUS)
WILL BE LOCATED OVER SOUTHERN MINNESOTA WEDNESDAY MORNING AND WILL
LIFT NORTH-NORTHEAST ACROSS FAR WESTERN LAKE SUPERIOR WEDNESDAY
EVENING. COOL SOUTHEASTERLY FLOW WILL BE IN PLACE AHEAD OF THE LOW
EARLY WEDNESDAY MORNING AND WILL LIKELY LEAD TO ABUNDANT LOW
CLOUDS...FOG...AND SOME DRIZZLE OVER MUCH OF THE CWA (ALTHOUGH THE
DOWNSLOPING WINDS OVER THE FAR WEST WILL LIKELY LIMIT THE COVERAGE
SOME). THE INITIAL PUSH OF PRECIPITATION SHOULD BE CROSSING THE
WISCONSIN BORDER AT THE START OF THE PERIOD AND LIFT NORTH-NORTHEAST
ACROSS THE REST OF THE AREA THROUGH THE DAY. EXPECT THE BEST FORCING
AND DEEP MOISTURE TO OCCUR OVER THE WESTERN THIRD TO HALF OF THE
U.P. FIRST WITH THE INITIAL WAVE WEDNESDAY MORNING AND AGAIN WITH
THE MID-LEVEL LOW MOVING THROUGH LATE WEDNESDAY AFTERNOON INTO
WEDNESDAY EVENING. WITH THAT BEING SAID...THERE DOES APPEAR TO BE
ENOUGH 925-700MB FORCING TO SUPPORT A WAVE OF STRONGER PRECIPITATION
TO MOVE THROUGH THE CENTRAL AND EASTERN HALF OF THE CWA THROUGH THE
DAY ON WEDNESDAY. THAT FORCING SHOULD BE ENOUGH TO GENERATE
0.15-0.25IN OF QPF AND THE CONCERN FALLS TO P-TYPE. MODELS STILL
VARYING IN THE THERMAL PROFILE...WHICH LEADS TO LOW CONFIDENCE ON
THE EXACT PRECIP. THERE IS A NOSE OF WARM AIR ALOFT WITH THE
INITIAL PRECIP...BUT EVAPORATIVE COOLING SHOULD LOWER TEMPERATURES
IN THE MID LEVELS TOWARDS THE WETBULB...WHICH IS BELOW ZERO.
THUS...EXPECT A PERIOD OF SNOW BEFORE THE DEEPER MOISTURE CUTS OUT
AND TRANSITIONS THE PRECIP TO DRIZZLE OR RAIN (ALSO AS THE LOW
LEVELS WARM). OVER THE EAST...DID INCLUDE SOME SNOW DURING THE
MORNING...BUT CHANCES ARE LOW AND EXPECT PRIMARILY RAIN. WITH
THE BRIEF PERIOD OF DRYING ALOFT...FOR A COUPLE HOURS DURING MID
DAY...THAT WILL LIKELY TRANSITION THINGS TO MORE OF A DRIZZLE AWAY
FROM THE STRONGER PRECIP. WILL CONTINUE TO SHOW PRECIPITATION
CHANCES DIMINISHING THROUGH THE EVENING EXCEPT OVER THE FAR WEST
CLOSEST TO THE MID LEVEL LOW MOVING THROUGH.
BEHIND THE LOW...A TRAILING TROUGH WILL INITIALLY BE OVER NORTHERN
LAKE SUPERIOR BEFORE SHIFTING EAST THROUGH THE DAY ON THURSDAY.
THIS WILL USHER IN MUCH COLDER AIR OVER THE REGION...850MB TEMPS
FALLING FROM -5C AT 06Z THURSDAY TO -15C BY 06Z FRIDAY. THAT COLD
AIR AND ABUNDANT LOW LEVEL MOISTURE WILL LEAD TO LAKE EFFECT FOR
AREAS FAVORED BY WESTERLY WINDS. WILL SHOW POPS INCREASING THROUGH
THE DAY THURSDAY FOR THE WESTERLY WINDS FAVORED AREAS OF THE
WESTERN U.P. AND ESPECIALLY THE KEWEENAW PENINSULA. OVER THE
EAST...WINDS LOOK TO TAKE A LITTLE LONGER TO TURN WESTERLY OR
SLIGHT WEST-NORTHWEST AND WILL HAVE POPS INCREASING LATER THERE.
THERE IS STILL SOME DIFFERENCES IN THE LOW LEVEL WINDS FOR AREAS
OVER THE EAST THURSDAY NIGHT INTO FRIDAY...WHETHER THEY WILL BE
WEST-SOUTHWEST OR WEST-NORTHWEST...SO CONFIDENCE IS ON THE LOW SIDE
FOR THE LAKE EFFECT FOR EASTERN ALGER AND NORTHERN LUCE COUNTY
UNTIL THE WINDS TURN MORE FAVORABLE FRIDAY NIGHT. BUT OVER THE
WEST...THE FAVORABLE WESTERLY WINDS...INVERSION HEIGHTS AROUND
9-10KFT AND A BULK OF THE FORCING WITHIN THE DGZ WOULD SUPPORT
MODERATE LAKE EFFECT SNOW LATER THURSDAY AND ESPECIALLY THURSDAY
NIGHT INTO FRIDAY EVENING. WILL FOCUS THE HIGHEST POPS (DEFINITE)
FROM THE KEWEENAW THROUGH NORTHERN ONTONAGON COUNTY AND MATCH THAT
AREA WITH THE GREATEST SNOWFALL AMOUNTS. IT IS STILL A LITTLE WAYS
OUT...BUT THE INITIAL FORECAST HAS MUCH NEEDED 1-2 DAY SNOWFALL
AMOUNTS OF 6 PLUS INCHES. WILL LIKELY NEED AN ADVISORY FOR THE
KEWEENAW PENINSULA AREA AND WILL CONTINUE TO HIGHLIGHT THE POTENTIAL
FOR PLOW-ABLE SNOW IN THE HWO. THE SNOW IS EXPECTED TO DIMINISH
SATURDAY NIGHT AS DRY AIR WITH A SURFACE RIDGE MOVES INTO THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 623 AM EST TUE DEC 15 2015
A STRONG LOW PRESSURE SYSTEM MOVING INTO QUEBEC WILL KEEP LGT SNOW
AND POSSIBLE FREEZING DRIZZLE ACROSS THE TAF SITES THIS
MORNING...MAINLY AT KSAW. IFR CIGS AND VSBY ARE EXPECTED. VSBY WILL
IMPROVE TO VFR LATE TUE MORNING WITH CIGS RISING TO THE MVFR RANGE
TUE AFTN INTO TUE EVENING. ANOTHER LOW PRESSURE APPROACHING FROM THE
CENTRAL PLAINS WILL BRING A CHANCE FOR SOME MORE LIGHT SNOW OR PATCHY
FREEZING DRIZZLE LATE TONIGHT AS CONDITIONS LOWER TOWARD IFR ONCE
MORE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 529 AM EST TUE DEC 15 2015
N-NE WINDS WILL SUBSIDE TEMPORARILY ON THIS MORNING AS GRADIENT
WEAKENS BEFORE ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND SLIDES
THROUGH THE UPPER GREAT LAKES WEDNESDAY INTO THURSDAY. NORTHEAST
WINDS WILL INCREASE TO GALES OVER THE WEST HALF THIS EVENING INTO
WED MORNING AND SOUTHEAST WINDS SHOULD REACH GALE FORCE OVER THE
CENTRAL AND EASTERN LAKE AHEAD OF THE LOW LATE TONIGHT THROUGH
WEDNESDAY FOLLOWED BY WESTERLY WINDS APPROACHING GALES IN THE COLD
ADVECTION BEHIND THE LOW ON THURSDAY INTO FRIDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
263-264-267.
GALE WARNING FROM 7 AM TO 9 PM EST WEDNESDAY FOR LSZ267.
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ265-266.
GALE WARNING FROM 4 AM TO 6 PM EST WEDNESDAY FOR LSZ263>266.
GALE WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 9 AM EST
/8 AM CST/ WEDNESDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
532 AM EST TUE DEC 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 529 AM EST TUE DEC 15 2015
WATER VAPOR LOOP AND RAP ANALYSIS SHOWS CLOSED LOW OVER SE ONTARIO
WITHIN MID-UPPER TROUGH. SOME MOISTURE WRAPPING BACK AROUND THE LOW
INTO THE UPPER GREAT LAKES IS HELPING TO SUSTAIN SOME UPSLOPE
ENHANCED LAKE EFFECT SNOW SHOWERS OVER NORTH CENTRAL UPPER MI IN
WEAKLY CYCLONIC NORTHERLY FLOW. MOISTURE BARELY REACHING TO -9/-10C
HAS RESULTED IN SMALL FLAKE SIZE EARLY THIS MORNING WHICH HAS
GENERALLY LIMITED ADDITIONAL ACCUMULATION TO AN INCH OR LESS MOST
PLACES...ALTHOUGH SMALLER FLAKE SIZE IS CONTRIBUTING TO BIT MORE
BLOWING OF SNOW NEAR LAKE SUPERIOR AS NORTH WINDS ARE STILL GUSTING
TO 25 TO 30 MPH. FARTHER UPSTREAM TO THE WEST...A MID-UPPER LEVEL
RIDGE IS OVER THE PLAINS WITH A BROAD TROUGH OVER THE ROCKIES AND A
CLOSED LOW OVER EASTERN CO.
TODAY...A MUCH QUIETER WEATHER DAY IS EXPECTED ACROSS THE U.P.
SURFACE LOW OVER SOUTHERN QUEBEC WILL CONTINUE TO MOVE EAST THROUGH
THE DAY AS SFC HIGH PRESSURE AND UPPER LEVEL RIDGING BUILD IN FROM
THE PLAINS. THIS RIDGING WILL ALLOW FOR DRIER CONDITIONS ACROSS
UPPER MICHIGAN...HOWEVER...CLOUD COVER WILL LINGER THROUGH THE DAY
AS LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE LOWERING SUBSIDENCE
INVERSION. LOWERING INVERSION HEIGHT WITH INCREASINGLY
ANTICYCLONIC/DIVERGENT FLOW FROM BUILDING RIDGE SHOULD HELP END ANY
LINGERING LES OVER NORTH CENTRAL UPPER MI BY LATE MORNING/EARLY
AFTERNOON. UPSLOPE NE FLOW COULD STILL CONTRIBUTE TO FLURRIES/PATCHY
FZDZ INTO EARLY AFTERNOON. TEMPERATURES WILL BE MUCH COOLER THAN
YESTERDAY...ESPECIALLY OVER THE EAST HALF...WITH HIGHS RANGING FROM
LOWER 30S WEST TO MID 30S SOUTH CENTRAL AND EAST.
TONIGHT...RIDGING OVER THE AREA SHOULD CONTINUE QUIET WEATHER INTO
THE EVENING HOURS BUT THEN INCREASED MID-LVL Q-VECT CONV AND UPPER
DIFFLUENCE IN ADVANCE OF LOW PRESSURE SYSTEM LIFTING THROUGH THE
CENTRAL PLAINS WILL BRING AN INCREASED CHANCE OF PRECIPITATION
ESPECIALLY LATE TONIGHT. FAIRLY SHALLOW MOISTURE GENERALLY EXTENDING
NO HIGHER THAN 800 MB LEVEL MAY LIMIT MUCH OF THE PRECIPITATION
INITIALLY TONIGHT TO DRIZZLE OR FREEZING DRIZZLE AS MOISTURE WILL
REMAIN BLO THE DGZ. BEST CHANCE OF PRECIPITATION WILL BE THOSE
LOCATIONS FAVORED BY INCREASINGLY CYCLONIC UPSLOPE E-SE FLOW. MIN
TEMPS WILL GENERALLY RANGE FROM THE MID TO UPPER 20S INLAND TO THE
LOWER 30S NEAR THE GREAT LAKES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 358 AM EST TUE DEC 15 2015
A FAIRLY ACTIVE LONG TERM FORECAST IS EXPECT ACROSS THE UPPER GREAT
LAKES REGION AS ANOTHER LOW PRESSURE SYSTEM WILL LIFT NORTHEAST
THROUGH THE WESTERN GREAT LAKES REGION WEDNESDAY INTO WEDNESDAY
NIGHT. MUCH COLDER AIR WILL ARRIVE BEHIND THE LOW AND LEAD TO A
PERIOD OF LAKE EFFECT SNOW AS THE LOW BECOMES STATIONARY OVER FAR
NORTHERN ONTARIO THURSDAY NIGHT AND REMAINS THERE INTO SATURDAY.
HIGH PRESSURE WILL FINALLY BUILD OVER THE REGION FOR THE SECOND
HALF OF THE WEEKEND BEFORE ANOTHER LOW MOVES THROUGH THE REGION
DURING THE MONDAY/TUESDAY TIME FRAME.
THE INITIAL LOW (UPPER WAVE CURRENTLY OVER THE SOUTHWESTERN CONUS)
WILL BE LOCATED OVER SOUTHERN MINNESOTA WEDNESDAY MORNING AND WILL
LIFT NORTH-NORTHEAST ACROSS FAR WESTERN LAKE SUPERIOR WEDNESDAY
EVENING. COOL SOUTHEASTERLY FLOW WILL BE IN PLACE AHEAD OF THE LOW
EARLY WEDNESDAY MORNING AND WILL LIKELY LEAD TO ABUNDANT LOW
CLOUDS...FOG...AND SOME DRIZZLE OVER MUCH OF THE CWA (ALTHOUGH THE
DOWNSLOPING WINDS OVER THE FAR WEST WILL LIKELY LIMIT THE COVERAGE
SOME). THE INITIAL PUSH OF PRECIPITATION SHOULD BE CROSSING THE
WISCONSIN BORDER AT THE START OF THE PERIOD AND LIFT NORTH-NORTHEAST
ACROSS THE REST OF THE AREA THROUGH THE DAY. EXPECT THE BEST FORCING
AND DEEP MOISTURE TO OCCUR OVER THE WESTERN THIRD TO HALF OF THE
U.P. FIRST WITH THE INITIAL WAVE WEDNESDAY MORNING AND AGAIN WITH
THE MID-LEVEL LOW MOVING THROUGH LATE WEDNESDAY AFTERNOON INTO
WEDNESDAY EVENING. WITH THAT BEING SAID...THERE DOES APPEAR TO BE
ENOUGH 925-700MB FORCING TO SUPPORT A WAVE OF STRONGER PRECIPITATION
TO MOVE THROUGH THE CENTRAL AND EASTERN HALF OF THE CWA THROUGH THE
DAY ON WEDNESDAY. THAT FORCING SHOULD BE ENOUGH TO GENERATE
0.15-0.25IN OF QPF AND THE CONCERN FALLS TO P-TYPE. MODELS STILL
VARYING IN THE THERMAL PROFILE...WHICH LEADS TO LOW CONFIDENCE ON
THE EXACT PRECIP. THERE IS A NOSE OF WARM AIR ALOFT WITH THE
INITIAL PRECIP...BUT EVAPORATIVE COOLING SHOULD LOWER TEMPERATURES
IN THE MID LEVELS TOWARDS THE WETBULB...WHICH IS BELOW ZERO.
THUS...EXPECT A PERIOD OF SNOW BEFORE THE DEEPER MOISTURE CUTS OUT
AND TRANSITIONS THE PRECIP TO DRIZZLE OR RAIN (ALSO AS THE LOW
LEVELS WARM). OVER THE EAST...DID INCLUDE SOME SNOW DURING THE
MORNING...BUT CHANCES ARE LOW AND EXPECT PRIMARILY RAIN. WITH
THE BRIEF PERIOD OF DRYING ALOFT...FOR A COUPLE HOURS DURING MID
DAY...THAT WILL LIKELY TRANSITION THINGS TO MORE OF A DRIZZLE AWAY
FROM THE STRONGER PRECIP. WILL CONTINUE TO SHOW PRECIPITATION
CHANCES DIMINISHING THROUGH THE EVENING EXCEPT OVER THE FAR WEST
CLOSEST TO THE MID LEVEL LOW MOVING THROUGH.
BEHIND THE LOW...A TRAILING TROUGH WILL INITIALLY BE OVER NORTHERN
LAKE SUPERIOR BEFORE SHIFTING EAST THROUGH THE DAY ON THURSDAY.
THIS WILL USHER IN MUCH COLDER AIR OVER THE REGION...850MB TEMPS
FALLING FROM -5C AT 06Z THURSDAY TO -15C BY 06Z FRIDAY. THAT COLD
AIR AND ABUNDANT LOW LEVEL MOISTURE WILL LEAD TO LAKE EFFECT FOR
AREAS FAVORED BY WESTERLY WINDS. WILL SHOW POPS INCREASING THROUGH
THE DAY THURSDAY FOR THE WESTERLY WINDS FAVORED AREAS OF THE
WESTERN U.P. AND ESPECIALLY THE KEWEENAW PENINSULA. OVER THE
EAST...WINDS LOOK TO TAKE A LITTLE LONGER TO TURN WESTERLY OR
SLIGHT WEST-NORTHWEST AND WILL HAVE POPS INCREASING LATER THERE.
THERE IS STILL SOME DIFFERENCES IN THE LOW LEVEL WINDS FOR AREAS
OVER THE EAST THURSDAY NIGHT INTO FRIDAY...WHETHER THEY WILL BE
WEST-SOUTHWEST OR WEST-NORTHWEST...SO CONFIDENCE IS ON THE LOW SIDE
FOR THE LAKE EFFECT FOR EASTERN ALGER AND NORTHERN LUCE COUNTY
UNTIL THE WINDS TURN MORE FAVORABLE FRIDAY NIGHT. BUT OVER THE
WEST...THE FAVORABLE WESTERLY WINDS...INVERSION HEIGHTS AROUND
9-10KFT AND A BULK OF THE FORCING WITHIN THE DGZ WOULD SUPPORT
MODERATE LAKE EFFECT SNOW LATER THURSDAY AND ESPECIALLY THURSDAY
NIGHT INTO FRIDAY EVENING. WILL FOCUS THE HIGHEST POPS (DEFINITE)
FROM THE KEWEENAW THROUGH NORTHERN ONTONAGON COUNTY AND MATCH THAT
AREA WITH THE GREATEST SNOWFALL AMOUNTS. IT IS STILL A LITTLE WAYS
OUT...BUT THE INITIAL FORECAST HAS MUCH NEEDED 1-2 DAY SNOWFALL
AMOUNTS OF 6 PLUS INCHES. WILL LIKELY NEED AN ADVISORY FOR THE
KEWEENAW PENINSULA AREA AND WILL CONTINUE TO HIGHLIGHT THE POTENTIAL
FOR PLOW-ABLE SNOW IN THE HWO. THE SNOW IS EXPECTED TO DIMINISH
SATURDAY NIGHT AS DRY AIR WITH A SURFACE RIDGE MOVES INTO THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY MORNING) ISSUED
AT 414 AM EST TUE DEC 15 2015
A STRONG LOW PRESSURE SYSTEM MOVING INTO QUEBEC WILL KEEP LGT SNOW
AND POSSIBLE FREEZING DRIZZLE ACROSS THE TAF SITES OVERNIGHT INTO
TUE MORNING. IFR CIGS AND VSBY ARE EXPECTED. VSBY WILL IMPROVE TO
VFR LATER TUE MORNING WITH CIGS RISING TO THE MVFR RANGE TUE AFTN
INTO TUE EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 529 AM EST TUE DEC 15 2015
N-NE WINDS WILL SUBSIDE TEMPORARILY ON THIS MORNING AS GRADIENT
WEAKENS BEFORE ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND SLIDES
THROUGH THE UPPER GREAT LAKES WEDNESDAY INTO THURSDAY. NORTHEAST
WINDS WILL INCREASE TO GALES OVER THE WEST HALF THIS EVENING INTO
WED MORNING AND SOUTHEAST WINDS SHOULD REACH GALE FORCE OVER THE
CENTRAL AND EASTERN LAKE AHEAD OF THE LOW LATE TONIGHT THROUGH
WEDNESDAY FOLLOWED BY WESTERLY WINDS APPROACHING GALES IN THE COLD
ADVECTION BEHIND THE LOW ON THURSDAY INTO FRIDAY NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
263-264-267.
GALE WARNING FROM 7 AM TO 9 PM EST WEDNESDAY FOR LSZ267.
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ265-266.
GALE WARNING FROM 4 AM TO 6 PM EST WEDNESDAY FOR LSZ263>266.
GALE WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 9 AM EST
/8 AM CST/ WEDNESDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...JLA
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
414 AM EST TUE DEC 15 2015
.UPDATE...
ISSUED AT 547 PM EST MON DEC 14 2015
EXPANDED WINTER WEATHER ADVISORY ACROSS REST OF WESTERN UPR MICHIGAN
THIS EVENING AS REPORTS ARE INDICATING MAINLY SLEET IS OCCURRING IN
DEFORMATION BAND OF WINTRY PRECIP ON WEST SIDE OF SFC LOW VCNTY OF
KISQ AS OF 5 PM. 21Z RAP PEGGING LOCATION OF DEFORMATION BAND WELL
THOUGH SOUNDINGS ARE A BIT TOO COLD ALOFT COMPARED TO REALITY. RAP
SHOWS DEFORMATION BAND WITH QPF AMOUNTS TO 0.15 INCHES THROUGH 00Z
THEN BEGINS TO TAPER. GIVEN MOST OF THE PRECIP IS FALLING AS SLEET
WHICH IS REALLY LEADING TO ROUGH ROAD CONDITIONS PER REPORTS FM
SPOTTERS IN ONTONAGON COUNTY AND SHERIFF IN BARAGA COUNTY...EXPANDED
THE ADVY. A COLD RAIN FARTHER EAST...WITH NWS OFFICE SITTING AT 32-33
AS OF 530 PM. FOR NOW SPS IS OUT FOR IRON/DICKINSON/MARQUETTE AND
THAT PROBABLY WILL HOLD UNLESS HEAVIER DEFORMATION PRECIP SLIDES
FARTHER EAST. WILL KEEP MONITORING THIS. HIGHEST SNOW/SLEET TOTAL WAS
AROUND 2 INCHES FAR WEST...BUT ALREADY SEEING 1-2 INCHES HIGHER
TERRAIN BETWEEN ONTONAGON AND HOUGHTON AND MOST RECENTLY NEAR HERMAN
IN HIGHER TERRAIN OF BARAGA COUNTY. ALL AREAS CURRENTLY SEEING THE
SNOW/SLEET MAY SEE ADDITIONAL 1-2 INCHES BEFORE THE EVENING IS OUT SO
ROADS WILL CONTINUE TO BE IN ROUGH SHAPE.
CURRENT WINTER WEATHER ADVISORIES GO UNTIL 06Z. MAYBE A BIT
LONG...BUT CAN EVALUATE THAT LATER THIS EVENING. COULD SEE THIS
WHOLE WINTRY MIX CHANGE TO DRIZZLE/FREEZING DRIZZLE LATER TONIGHT.
OVERALL A MESSY NIGHT...ESPECIALLY FOR THE HIGHLANDS OF WESTERN UPR
MICHIGAN.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 402 PM EST MON DEC 14 2015
TRICKY FORECAST WITH PRECIPITATION TYPE LATE THIS AFTERNOON INTO
THIS EVENING. WINTER WEATHER ADVISORY IN EFFECT THROUGH 06Z/15FOR
GOGEBIC AND ONTONAGON COUNTIES.
RADAR IMAGERY CONTINUES TO SHOW A WIDE SWATH OF PRECIPITATION ACROSS
THE U.P. STRETCHING BACK INTO THROUGH PORTIONS OF NORTHERN AND
WESTERN WI. SATELLITE IMAGERY SHOWS EXTENSIVE CLOUD COVER ACROSS THE
UPPER GREAT LAKES. WV IMAGERY SHOWS THE UPPER LEVEL LOW CENTERED
OVER SOUTHERN WI THIS AFTERNOON WITH PLENTY OF MOISTURE TO THE NORTH
AND WEST OF THE LOW. THE DRY SLOT ASSOCIATED WITH THE LOW IS WORKING
IN ACROSS SOUTHERN LOWER MI AND THE OHIO VALLEY. SURFACE
OBSERVATIONS...OBSERVERS AND WEBCAMS HAVE BEEN SHOWING A MIX OF
FREEZING RAIN...SLEET AND SNOW ACROSS FAR WESTERN PORTIONS OF THE
U.P. SPECIFICALLY AROUND GOGEBIC AND ONTONAGON COUNTIES.
LATE THIS AFTERNOON THROUGH TONIGHT...THE FAIRLY STRONG SURFACE LOW
SLIDING THROUGH THE U.P. THIS AFTERNOON WILL CONTINUE TO PRODUCE
WIDESPREAD RAINFALL ACROSS THE NORTH HALF OF THE U.P. THESE AREAS
COULD SEE AN ADDITIONAL 0.5 INCH TO 0.75 INCH OF QPF DURING THE MID
TO LATE AFTERNOON HOURS. THE DEEP LAYER FORCING ASSOCIATED WITH THE
LOW WILL LINGER BETWEEN 18Z/14 AND 00Z/15 BEFORE EXITING TO THE
NORTH AND EAST OF THE AREA DURING THE EVENING AND OVERNIGHT HOURS.
THIS CAN BE SEEN BY ANALYZING THE DEEP LAYER QCONV ALONG WITH 1000-
500MB RH. THE BIG ISSUE...HOWEVER...IS PRECIPITATION TYPE. MODELS
HAVE A WARM NOSE ALOFT BETWEEN 800MB AND 850MB...AND A COLDER LAYER
BELOW WHICH HAS LED TO A MIXED BAG OF PRECIPITATION OVER THE FAR
WESTERN U.P. THIS HAS RESULTED IN MAINLY SLEET...HOWEVER...SOME
FREEZING RAIN HAS BEEN REPORTED ACROSS THE FAR WEST AREA AS SURFACE
TEMPERATURES HOVER AROUND 32F.
TIMING OF TRANSITION ACROSS THE U.P. WILL BE A BIT TRICKY...BUT
LATEST MODEL DATA SUGGESTS THAT RAIN WILL MIX WITH SLEET OVER
CENTRAL PORTIONS OF THE U.P. BY 21Z-22Z AND THEN OVER TO SNOW LATER
IN THE EVENING. OVER THE EAST HALF OF THE UPPER
PENINSULA...TEMPERATURES SHOULD REMAIN WARM ENOUGH TO KEEP THE
PRECIPITATION IN THE FORM OF RAIN UNTIL LATE EVENING...WHEN THE
DEEPER MOISTURE PULLS AWAY FROM THE REGION. THE HEAVIEST SLEET/SNOW
TOTALS WILL LIKELY REMAIN CONFINED TO THE GOGEBIC AND ONTONAGON
AREAS AND UP THROUGH THE KEEWEENAW PENINSULA...WHERE THE DEFORMATION
BAND HAS SET UP UNDER THE COMMA HEAD OF THE LOW PRESSURE SYSTEM THIS
AFTERNOON. THIS DEFORMATION BAND IS ON A PIVOT POINT AS THE SURFACE
LOW TAKES ON A MORE EAST TO EAST-NORTHEASTERLY TRACK...HELPING TO
CONCENTRATE THE SNOW/SLEET TOTALS IN THAT AREA. THE FORCING IN THAT
AREA IS ACTUALLY PROVIDING ENOUGH LIFT THIS AFTERNOON TO MIX SOME
SNOWFALL IN WITH THE SLEET. AS FAR AS TOTALS...BY THE TIME THE
DEEPER MOISTURE LEAVE THIS EVENING...WILL BE AROUND 2 TO 4 INCHES IN
ONTONAGON AND GOGEBIC COUNTIES. FARTHER NORTH IN THE KEWEENAW LOOKS
LIKE AROUND 1 TO 2 INCHES...WHILE CENTRAL AREAS WILL LIKELY SEE AN
INCH OR LESS AS THE DEFORMATION SLIDES THROUGH AT A FASTER PACE IN
THOSE AREAS. ONCE THE DEEPER MOISTURE DEPARTS TONIGHT...EXPECT MOST
OF THE PRECIPITATION TO TRANSITION TO DRIZZLE OR FREEZING
DRIZZLE...BUT SNOW WILL ALSO MIX IN OVER THE HIGHER TERRAIN OF THE
WEST...ESPECIALLY ALONG LAKE SUPERIOR WHERE UPSLOPE COULD PROVIDE
ENOUGH LIFT TO INTRODUCE ICE CRYSTALS INTO THE LAYER.
TUESDAY...A MUCH QUIETER WEATHER DAY CAN BE EXPECTED ACROSS THE U.P.
AS THE SURFACE LOW AND UPPER LEVEL LOW PRESSURE SLIDE INTO SOUTHERN
QUEBEC. HIGH PRESSURE AND UPPER LEVEL RIDGING WILL SLIDE IN BEHIND
THE LOW. THIS WILL ALLOW FOR DRIER CONDITIONS ACROSS UPPER
MICHIGAN...HOWEVER...CLOUD COVER WILL LINGER THROUGH THE DAY WITH
CONTINUED LOW LEVEL MOISTURE TRAPPED BELOW THE INVERSION IN PLACE
FROM THE UPPER LEVEL RIDGING SLIDING INTO THE AREA. TEMPERATURESWILL
BE MUCH COOLER...ESPECIALLY OVER THE EAST HALF WITH HIGHS ONLY
REACHING INTO THE LOW TO MID 30S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 358 AM EST TUE DEC 15 2015
A FAIRLY ACTIVE LONG TERM FORECAST IS EXPECT ACROSS THE UPPER GREAT
LAKES REGION AS ANOTHER LOW PRESSURE SYSTEM WILL LIFT NORTHEAST
THROUGH THE WESTERN GREAT LAKES REGION WEDNESDAY INTO WEDNESDAY
NIGHT. MUCH COLDER AIR WILL ARRIVE BEHIND THE LOW AND LEAD TO A
PERIOD OF LAKE EFFECT SNOW AS THE LOW BECOMES STATIONARY OVER FAR
NORTHERN ONTARIO THURSDAY NIGHT AND REMAINS THERE INTO SATURDAY.
HIGH PRESSURE WILL FINALLY BUILD OVER THE REGION FOR THE SECOND
HALF OF THE WEEKEND BEFORE ANOTHER LOW MOVES THROUGH THE REGION
DURING THE MONDAY/TUESDAY TIME FRAME.
THE INITIAL LOW (UPPER WAVE CURRENTLY OVER THE SOUTHWESTERN CONUS)
WILL BE LOCATED OVER SOUTHERN MINNESOTA WEDNESDAY MORNING AND WILL
LIFT NORTH-NORTHEAST ACROSS FAR WESTERN LAKE SUPERIOR WEDNESDAY
EVENING. COOL SOUTHEASTERLY FLOW WILL BE IN PLACE AHEAD OF THE LOW
EARLY WEDNESDAY MORNING AND WILL LIKELY LEAD TO ABUNDANT LOW
CLOUDS...FOG...AND SOME DRIZZLE OVER MUCH OF THE CWA (ALTHOUGH THE
DOWNSLOPING WINDS OVER THE FAR WEST WILL LIKELY LIMIT THE COVERAGE
SOME). THE INITIAL PUSH OF PRECIPITATION SHOULD BE CROSSING THE
WISCONSIN BORDER AT THE START OF THE PERIOD AND LIFT NORTH-NORTHEAST
ACROSS THE REST OF THE AREA THROUGH THE DAY. EXPECT THE BEST FORCING
AND DEEP MOISTURE TO OCCUR OVER THE WESTERN THIRD TO HALF OF THE
U.P. FIRST WITH THE INITIAL WAVE WEDNESDAY MORNING AND AGAIN WITH
THE MID-LEVEL LOW MOVING THROUGH LATE WEDNESDAY AFTERNOON INTO
WEDNESDAY EVENING. WITH THAT BEING SAID...THERE DOES APPEAR TO BE
ENOUGH 925-700MB FORCING TO SUPPORT A WAVE OF STRONGER PRECIPITATION
TO MOVE THROUGH THE CENTRAL AND EASTERN HALF OF THE CWA THROUGH THE
DAY ON WEDNESDAY. THAT FORCING SHOULD BE ENOUGH TO GENERATE
0.15-0.25IN OF QPF AND THE CONCERN FALLS TO P-TYPE. MODELS STILL
VARYING IN THE THERMAL PROFILE...WHICH LEADS TO LOW CONFIDENCE ON
THE EXACT PRECIP. THERE IS A NOSE OF WARM AIR ALOFT WITH THE
INITIAL PRECIP...BUT EVAPORATIVE COOLING SHOULD LOWER TEMPERATURES
IN THE MID LEVELS TOWARDS THE WETBULB...WHICH IS BELOW ZERO.
THUS...EXPECT A PERIOD OF SNOW BEFORE THE DEEPER MOISTURE CUTS OUT
AND TRANSITIONS THE PRECIP TO DRIZZLE OR RAIN (ALSO AS THE LOW
LEVELS WARM). OVER THE EAST...DID INCLUDE SOME SNOW DURING THE
MORNING...BUT CHANCES ARE LOW AND EXPECT PRIMARILY RAIN. WITH
THE BRIEF PERIOD OF DRYING ALOFT...FOR A COUPLE HOURS DURING MID
DAY...THAT WILL LIKELY TRANSITION THINGS TO MORE OF A DRIZZLE AWAY
FROM THE STRONGER PRECIP. WILL CONTINUE TO SHOW PRECIPITATION
CHANCES DIMINISHING THROUGH THE EVENING EXCEPT OVER THE FAR WEST
CLOSEST TO THE MID LEVEL LOW MOVING THROUGH.
BEHIND THE LOW...A TRAILING TROUGH WILL INITIALLY BE OVER NORTHERN
LAKE SUPERIOR BEFORE SHIFTING EAST THROUGH THE DAY ON THURSDAY.
THIS WILL USHER IN MUCH COLDER AIR OVER THE REGION...850MB TEMPS
FALLING FROM -5C AT 06Z THURSDAY TO -15C BY 06Z FRIDAY. THAT COLD
AIR AND ABUNDANT LOW LEVEL MOISTURE WILL LEAD TO LAKE EFFECT FOR
AREAS FAVORED BY WESTERLY WINDS. WILL SHOW POPS INCREASING THROUGH
THE DAY THURSDAY FOR THE WESTERLY WINDS FAVORED AREAS OF THE
WESTERN U.P. AND ESPECIALLY THE KEWEENAW PENINSULA. OVER THE
EAST...WINDS LOOK TO TAKE A LITTLE LONGER TO TURN WESTERLY OR
SLIGHT WEST-NORTHWEST AND WILL HAVE POPS INCREASING LATER THERE.
THERE IS STILL SOME DIFFERENCES IN THE LOW LEVEL WINDS FOR AREAS
OVER THE EAST THURSDAY NIGHT INTO FRIDAY...WHETHER THEY WILL BE
WEST-SOUTHWEST OR WEST-NORTHWEST...SO CONFIDENCE IS ON THE LOW SIDE
FOR THE LAKE EFFECT FOR EASTERN ALGER AND NORTHERN LUCE COUNTY
UNTIL THE WINDS TURN MORE FAVORABLE FRIDAY NIGHT. BUT OVER THE
WEST...THE FAVORABLE WESTERLY WINDS...INVERSION HEIGHTS AROUND
9-10KFT AND A BULK OF THE FORCING WITHIN THE DGZ WOULD SUPPORT
MODERATE LAKE EFFECT SNOW LATER THURSDAY AND ESPECIALLY THURSDAY
NIGHT INTO FRIDAY EVENING. WILL FOCUS THE HIGHEST POPS (DEFINITE)
FROM THE KEWEENAW THROUGH NORTHERN ONTONAGON COUNTY AND MATCH THAT
AREA WITH THE GREATEST SNOWFALL AMOUNTS. IT IS STILL A LITTLE WAYS
OUT...BUT THE INITIAL FORECAST HAS MUCH NEEDED 1-2 DAY SNOWFALL
AMOUNTS OF 6 PLUS INCHES. WILL LIKELY NEED AN ADVISORY FOR THE
KEWEENAW PENINSULA AREA AND WILL CONTINUE TO HIGHLIGHT THE POTENTIAL
FOR PLOW-ABLE SNOW IN THE HWO. THE SNOW IS EXPECTED TO DIMINISH
SATURDAY NIGHT AS DRY AIR WITH A SURFACE RIDGE MOVES INTO THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY MORNING) ISSUED
AT 414 AM EST TUE DEC 15 2015
A STRONG LOW PRESSURE SYSTEM MOVING INTO QUEBEC WILL KEEP LGT SNOW
AND POSSIBLE FREEZING DRIZZLE ACROSS THE TAF SITES OVERNIGHT INTO
TUE MORNING. IFR CIGS AND VSBY ARE EXPECTED. VSBY WILL IMPROVE TO
VFR LATER TUE MORNING WITH CIGS RISING TO THE MVFR RANGE TUE AFTN
INTO TUE EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 PM EST MON DEC 14 2015
AS LOW PRESSURE SLIDES ACROSS THE EASTERN UP THIS AFTERNOON INTO
TONIGHT...NORTHEAST GALES WILL TRANSITION TO NORTH GALES ACROSS LAKE
SUPERIOR AS COLDER AIR FILTERS ACROSS THE LAKE. THERE IS A POTENTIAL
FOR A FEW STORM FORCE GUSTS LATE THIS AFTERNOON INTO THE EARLY
EVENING HOURS...ESPECIALLY BETWEEN ISLE ROYALE AND THE KEWEENAW.
WINDS WILL SUBSIDE TEMPORARILY ON TUESDAY MORNING BEFORE ANOTHER LOW
PRESSURE SYSTEM DEVELOPS AND SLIDES THROUGH THE UPPER GREAT LAKES
WEDNESDAY INTO THURSDAY. NORTHEAST WINDS WILL INCREASE TO GALES OVER
THE WEST HALF LATE TUE INTO WED MORNING AND SOUTHEAST WINDS SHOULD
REACH GALE FORCE OVER THE CENTRAL AND EASTERN LAKE AHEAD OF THE LOW
ON WEDNESDAY FOLLOWED BY WESTERLY WINDS APPROACHING GALES IN THECOLD
ADVECTION BEHIND THE LOW ON THURSDAY INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
263-264-267.
GALE WARNING FROM 7 AM TO 9 PM EST WEDNESDAY FOR LSZ267.
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ265-266.
GALE WARNING FROM 4 AM TO 6 PM EST WEDNESDAY FOR LSZ263>266.
GALE WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 9 AM EST
/8 AM CST/ WEDNESDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...KEC
LONG TERM...SRF
AVIATION...JLA
MARINE...KEC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
359 AM EST TUE DEC 15 2015
.UPDATE...
ISSUED AT 547 PM EST MON DEC 14 2015
EXPANDED WINTER WEATHER ADVISORY ACROSS REST OF WESTERN UPR MICHIGAN
THIS EVENING AS REPORTS ARE INDICATING MAINLY SLEET IS OCCURRING IN
DEFORMATION BAND OF WINTRY PRECIP ON WEST SIDE OF SFC LOW VCNTY OF
KISQ AS OF 5 PM. 21Z RAP PEGGING LOCATION OF DEFORMATION BAND WELL
THOUGH SOUNDINGS ARE A BIT TOO COLD ALOFT COMPARED TO REALITY. RAP
SHOWS DEFORMATION BAND WITH QPF AMOUNTS TO 0.15 INCHES THROUGH 00Z
THEN BEGINS TO TAPER. GIVEN MOST OF THE PRECIP IS FALLING AS SLEET
WHICH IS REALLY LEADING TO ROUGH ROAD CONDITIONS PER REPORTS FM
SPOTTERS IN ONTONAGON COUNTY AND SHERIFF IN BARAGA COUNTY...EXPANDED
THE ADVY. A COLD RAIN FARTHER EAST...WITH NWS OFFICE SITTING AT 32-33
AS OF 530 PM. FOR NOW SPS IS OUT FOR IRON/DICKINSON/MARQUETTE AND
THAT PROBABLY WILL HOLD UNLESS HEAVIER DEFORMATION PRECIP SLIDES
FARTHER EAST. WILL KEEP MONITORING THIS. HIGHEST SNOW/SLEET TOTAL WAS
AROUND 2 INCHES FAR WEST...BUT ALREADY SEEING 1-2 INCHES HIGHER
TERRAIN BETWEEN ONTONAGON AND HOUGHTON AND MOST RECENTLY NEAR HERMAN
IN HIGHER TERRAIN OF BARAGA COUNTY. ALL AREAS CURRENTLY SEEING THE
SNOW/SLEET MAY SEE ADDITIONAL 1-2 INCHES BEFORE THE EVENING IS OUT SO
ROADS WILL CONTINUE TO BE IN ROUGH SHAPE.
CURRENT WINTER WEATHER ADVISORIES GO UNTIL 06Z. MAYBE A BIT
LONG...BUT CAN EVALUATE THAT LATER THIS EVENING. COULD SEE THIS
WHOLE WINTRY MIX CHANGE TO DRIZZLE/FREEZING DRIZZLE LATER TONIGHT.
OVERALL A MESSY NIGHT...ESPECIALLY FOR THE HIGHLANDS OF WESTERN UPR
MICHIGAN.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 402 PM EST MON DEC 14 2015
TRICKY FORECAST WITH PRECIPITATION TYPE LATE THIS AFTERNOON INTO
THIS EVENING. WINTER WEATHER ADVISORY IN EFFECT THROUGH 06Z/15FOR
GOGEBIC AND ONTONAGON COUNTIES.
RADAR IMAGERY CONTINUES TO SHOW A WIDE SWATH OF PRECIPITATION ACROSS
THE U.P. STRETCHING BACK INTO THROUGH PORTIONS OF NORTHERN AND
WESTERN WI. SATELLITE IMAGERY SHOWS EXTENSIVE CLOUD COVER ACROSS THE
UPPER GREAT LAKES. WV IMAGERY SHOWS THE UPPER LEVEL LOW CENTERED
OVER SOUTHERN WI THIS AFTERNOON WITH PLENTY OF MOISTURE TO THE NORTH
AND WEST OF THE LOW. THE DRY SLOT ASSOCIATED WITH THE LOW IS WORKING
IN ACROSS SOUTHERN LOWER MI AND THE OHIO VALLEY. SURFACE
OBSERVATIONS...OBSERVERS AND WEBCAMS HAVE BEEN SHOWING A MIX OF
FREEZING RAIN...SLEET AND SNOW ACROSS FAR WESTERN PORTIONS OF THE
U.P. SPECIFICALLY AROUND GOGEBIC AND ONTONAGON COUNTIES.
LATE THIS AFTERNOON THROUGH TONIGHT...THE FAIRLY STRONG SURFACE LOW
SLIDING THROUGH THE U.P. THIS AFTERNOON WILL CONTINUE TO PRODUCE
WIDESPREAD RAINFALL ACROSS THE NORTH HALF OF THE U.P. THESE AREAS
COULD SEE AN ADDITIONAL 0.5 INCH TO 0.75 INCH OF QPF DURING THE MID
TO LATE AFTERNOON HOURS. THE DEEP LAYER FORCING ASSOCIATED WITH THE
LOW WILL LINGER BETWEEN 18Z/14 AND 00Z/15 BEFORE EXITING TO THE
NORTH AND EAST OF THE AREA DURING THE EVENING AND OVERNIGHT HOURS.
THIS CAN BE SEEN BY ANALYZING THE DEEP LAYER QCONV ALONG WITH 1000-
500MB RH. THE BIG ISSUE...HOWEVER...IS PRECIPITATION TYPE. MODELS
HAVE A WARM NOSE ALOFT BETWEEN 800MB AND 850MB...AND A COLDER LAYER
BELOW WHICH HAS LED TO A MIXED BAG OF PRECIPITATION OVER THE FAR
WESTERN U.P. THIS HAS RESULTED IN MAINLY SLEET...HOWEVER...SOME
FREEZING RAIN HAS BEEN REPORTED ACROSS THE FAR WEST AREA AS SURFACE
TEMPERATURES HOVER AROUND 32F.
TIMING OF TRANSITION ACROSS THE U.P. WILL BE A BIT TRICKY...BUT
LATEST MODEL DATA SUGGESTS THAT RAIN WILL MIX WITH SLEET OVER
CENTRAL PORTIONS OF THE U.P. BY 21Z-22Z AND THEN OVER TO SNOW LATER
IN THE EVENING. OVER THE EAST HALF OF THE UPPER
PENINSULA...TEMPERATURES SHOULD REMAIN WARM ENOUGH TO KEEP THE
PRECIPITATION IN THE FORM OF RAIN UNTIL LATE EVENING...WHEN THE
DEEPER MOISTURE PULLS AWAY FROM THE REGION. THE HEAVIEST SLEET/SNOW
TOTALS WILL LIKELY REMAIN CONFINED TO THE GOGEBIC AND ONTONAGON
AREAS AND UP THROUGH THE KEEWEENAW PENINSULA...WHERE THE DEFORMATION
BAND HAS SET UP UNDER THE COMMA HEAD OF THE LOW PRESSURE SYSTEM THIS
AFTERNOON. THIS DEFORMATION BAND IS ON A PIVOT POINT AS THE SURFACE
LOW TAKES ON A MORE EAST TO EAST-NORTHEASTERLY TRACK...HELPING TO
CONCENTRATE THE SNOW/SLEET TOTALS IN THAT AREA. THE FORCING IN THAT
AREA IS ACTUALLY PROVIDING ENOUGH LIFT THIS AFTERNOON TO MIX SOME
SNOWFALL IN WITH THE SLEET. AS FAR AS TOTALS...BY THE TIME THE
DEEPER MOISTURE LEAVE THIS EVENING...WILL BE AROUND 2 TO 4 INCHES IN
ONTONAGON AND GOGEBIC COUNTIES. FARTHER NORTH IN THE KEWEENAW LOOKS
LIKE AROUND 1 TO 2 INCHES...WHILE CENTRAL AREAS WILL LIKELY SEE AN
INCH OR LESS AS THE DEFORMATION SLIDES THROUGH AT A FASTER PACE IN
THOSE AREAS. ONCE THE DEEPER MOISTURE DEPARTS TONIGHT...EXPECT MOST
OF THE PRECIPITATION TO TRANSITION TO DRIZZLE OR FREEZING
DRIZZLE...BUT SNOW WILL ALSO MIX IN OVER THE HIGHER TERRAIN OF THE
WEST...ESPECIALLY ALONG LAKE SUPERIOR WHERE UPSLOPE COULD PROVIDE
ENOUGH LIFT TO INTRODUCE ICE CRYSTALS INTO THE LAYER.
TUESDAY...A MUCH QUIETER WEATHER DAY CAN BE EXPECTED ACROSS THE U.P.
AS THE SURFACE LOW AND UPPER LEVEL LOW PRESSURE SLIDE INTO SOUTHERN
QUEBEC. HIGH PRESSURE AND UPPER LEVEL RIDGING WILL SLIDE IN BEHIND
THE LOW. THIS WILL ALLOW FOR DRIER CONDITIONS ACROSS UPPER
MICHIGAN...HOWEVER...CLOUD COVER WILL LINGER THROUGH THE DAY WITH
CONTINUED LOW LEVEL MOISTURE TRAPPED BELOW THE INVERSION IN PLACE
FROM THE UPPER LEVEL RIDGING SLIDING INTO THE AREA. TEMPERATURESWILL
BE MUCH COOLER...ESPECIALLY OVER THE EAST HALF WITH HIGHS ONLY
REACHING INTO THE LOW TO MID 30S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 358 AM EST TUE DEC 15 2015
A FAIRLY ACTIVE LONG TERM FORECAST IS EXPECT ACROSS THE UPPER GREAT
LAKES REGION AS ANOTHER LOW PRESSURE SYSTEM WILL LIFT NORTHEAST
THROUGH THE WESTERN GREAT LAKES REGION WEDNESDAY INTO WEDNESDAY
NIGHT. MUCH COLDER AIR WILL ARRIVE BEHIND THE LOW AND LEAD TO A
PERIOD OF LAKE EFFECT SNOW AS THE LOW BECOMES STATIONARY OVER FAR
NORTHERN ONTARIO THURSDAY NIGHT AND REMAINS THERE INTO SATURDAY.
HIGH PRESSURE WILL FINALLY BUILD OVER THE REGION FOR THE SECOND
HALF OF THE WEEKEND BEFORE ANOTHER LOW MOVES THROUGH THE REGION
DURING THE MONDAY/TUESDAY TIME FRAME.
THE INITIAL LOW (UPPER WAVE CURRENTLY OVER THE SOUTHWESTERN CONUS)
WILL BE LOCATED OVER SOUTHERN MINNESOTA WEDNESDAY MORNING AND WILL
LIFT NORTH-NORTHEAST ACROSS FAR WESTERN LAKE SUPERIOR WEDNESDAY
EVENING. COOL SOUTHEASTERLY FLOW WILL BE IN PLACE AHEAD OF THE LOW
EARLY WEDNESDAY MORNING AND WILL LIKELY LEAD TO ABUNDANT LOW
CLOUDS...FOG...AND SOME DRIZZLE OVER MUCH OF THE CWA (ALTHOUGH THE
DOWNSLOPING WINDS OVER THE FAR WEST WILL LIKELY LIMIT THE COVERAGE
SOME). THE INITIAL PUSH OF PRECIPITATION SHOULD BE CROSSING THE
WISCONSIN BORDER AT THE START OF THE PERIOD AND LIFT NORTH-NORTHEAST
ACROSS THE REST OF THE AREA THROUGH THE DAY. EXPECT THE BEST FORCING
AND DEEP MOISTURE TO OCCUR OVER THE WESTERN THIRD TO HALF OF THE
U.P. FIRST WITH THE INITIAL WAVE WEDNESDAY MORNING AND AGAIN WITH
THE MID-LEVEL LOW MOVING THROUGH LATE WEDNESDAY AFTERNOON INTO
WEDNESDAY EVENING. WITH THAT BEING SAID...THERE DOES APPEAR TO BE
ENOUGH 925-700MB FORCING TO SUPPORT A WAVE OF STRONGER PRECIPITATION
TO MOVE THROUGH THE CENTRAL AND EASTERN HALF OF THE CWA THROUGH THE
DAY ON WEDNESDAY. THAT FORCING SHOULD BE ENOUGH TO GENERATE
0.15-0.25IN OF QPF AND THE CONCERN FALLS TO P-TYPE. MODELS STILL
VARYING IN THE THERMAL PROFILE...WHICH LEADS TO LOW CONFIDENCE ON
THE EXACT PRECIP. THERE IS A NOSE OF WARM AIR ALOFT WITH THE
INITIAL PRECIP...BUT EVAPORATIVE COOLING SHOULD LOWER TEMPERATURES
IN THE MID LEVELS TOWARDS THE WETBULB...WHICH IS BELOW ZERO.
THUS...EXPECT A PERIOD OF SNOW BEFORE THE DEEPER MOISTURE CUTS OUT
AND TRANSITIONS THE PRECIP TO DRIZZLE OR RAIN (ALSO AS THE LOW
LEVELS WARM). OVER THE EAST...DID INCLUDE SOME SNOW DURING THE
MORNING...BUT CHANCES ARE LOW AND EXPECT PRIMARILY RAIN. WITH
THE BRIEF PERIOD OF DRYING ALOFT...FOR A COUPLE HOURS DURING MID
DAY...THAT WILL LIKELY TRANSITION THINGS TO MORE OF A DRIZZLE AWAY
FROM THE STRONGER PRECIP. WILL CONTINUE TO SHOW PRECIPITATION
CHANCES DIMINISHING THROUGH THE EVENING EXCEPT OVER THE FAR WEST
CLOSEST TO THE MID LEVEL LOW MOVING THROUGH.
BEHIND THE LOW...A TRAILING TROUGH WILL INITIALLY BE OVER NORTHERN
LAKE SUPERIOR BEFORE SHIFTING EAST THROUGH THE DAY ON THURSDAY.
THIS WILL USHER IN MUCH COLDER AIR OVER THE REGION...850MB TEMPS
FALLING FROM -5C AT 06Z THURSDAY TO -15C BY 06Z FRIDAY. THAT COLD
AIR AND ABUNDANT LOW LEVEL MOISTURE WILL LEAD TO LAKE EFFECT FOR
AREAS FAVORED BY WESTERLY WINDS. WILL SHOW POPS INCREASING THROUGH
THE DAY THURSDAY FOR THE WESTERLY WINDS FAVORED AREAS OF THE
WESTERN U.P. AND ESPECIALLY THE KEWEENAW PENINSULA. OVER THE
EAST...WINDS LOOK TO TAKE A LITTLE LONGER TO TURN WESTERLY OR
SLIGHT WEST-NORTHWEST AND WILL HAVE POPS INCREASING LATER THERE.
THERE IS STILL SOME DIFFERENCES IN THE LOW LEVEL WINDS FOR AREAS
OVER THE EAST THURSDAY NIGHT INTO FRIDAY...WHETHER THEY WILL BE
WEST-SOUTHWEST OR WEST-NORTHWEST...SO CONFIDENCE IS ON THE LOW SIDE
FOR THE LAKE EFFECT FOR EASTERN ALGER AND NORTHERN LUCE COUNTY
UNTIL THE WINDS TURN MORE FAVORABLE FRIDAY NIGHT. BUT OVER THE
WEST...THE FAVORABLE WESTERLY WINDS...INVERSION HEIGHTS AROUND
9-10KFT AND A BULK OF THE FORCING WITHIN THE DGZ WOULD SUPPORT
MODERATE LAKE EFFECT SNOW LATER THURSDAY AND ESPECIALLY THURSDAY
NIGHT INTO FRIDAY EVENING. WILL FOCUS THE HIGHEST POPS (DEFINITE)
FROM THE KEWEENAW THROUGH NORTHERN ONTONAGON COUNTY AND MATCH THAT
AREA WITH THE GREATEST SNOWFALL AMOUNTS. IT IS STILL A LITTLE WAYS
OUT...BUT THE INITIAL FORECAST HAS MUCH NEEDED 1-2 DAY SNOWFALL
AMOUNTS OF 6 PLUS INCHES. WILL LIKELY NEED AN ADVISORY FOR THE
KEWEENAW PENINSULA AREA AND WILL CONTINUE TO HIGHLIGHT THE POTENTIAL
FOR PLOW-ABLE SNOW IN THE HWO. THE SNOW IS EXPECTED TO DIMINISH
SATURDAY NIGHT AS DRY AIR WITH A SURFACE RIDGE MOVES INTO THE AREA.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 700 PM EST MON DEC 14 2015
A STRONG LOW PRESSURE SYSTEM MOVING ACROSS EASTERN UPPER MICHIGAN
THIS EVENING THEN ACROSS ONTARIO AND SOUTHERN QUEBEC LATE TONIGHT
WILL BRING A MIX OF SNOW/SLEET TO KIWD AND KCMX AND RAIN TO KSAW.
ALL PRECIPITATION WILL CHANGE TO SNOW OVERNIGHT. CONDITIONS WILL
REMAIN IFR/LIFR DUE TO COMBINATION OF SUB 1KFT FEET CIGS AND 1-3SM
VSBY. SNOW WILL MIX WITH DRIZZLE AND FREEZING DRIZZLE LATE TONIGHT.
CIGS AND VSBY STAY LOW ON TUE MORNING BUT WILL GRADUALLY IMPROVE ON
TUE AFTN WITH CIGS LIKELY RISING TO LOW MVFR RANGE.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 PM EST MON DEC 14 2015
AS LOW PRESSURE SLIDES ACROSS THE EASTERN UP THIS AFTERNOON INTO
TONIGHT...NORTHEAST GALES WILL TRANSITION TO NORTH GALES ACROSS LAKE
SUPERIOR AS COLDER AIR FILTERS ACROSS THE LAKE. THERE IS A POTENTIAL
FOR A FEW STORM FORCE GUSTS LATE THIS AFTERNOON INTO THE EARLY
EVENING HOURS...ESPECIALLY BETWEEN ISLE ROYALE AND THE KEWEENAW.
WINDS WILL SUBSIDE TEMPORARILY ON TUESDAY MORNING BEFORE ANOTHER LOW
PRESSURE SYSTEM DEVELOPS AND SLIDES THROUGH THE UPPER GREAT LAKES
WEDNESDAY INTO THURSDAY. NORTHEAST WINDS WILL INCREASE TO GALES OVER
THE WEST HALF LATE TUE INTO WED MORNING AND SOUTHEAST WINDS SHOULD
REACH GALE FORCE OVER THE CENTRAL AND EASTERN LAKE AHEAD OF THE LOW
ON WEDNESDAY FOLLOWED BY WESTERLY WINDS APPROACHING GALES IN THECOLD
ADVECTION BEHIND THE LOW ON THURSDAY INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
263-264-267.
GALE WARNING FROM 7 AM TO 9 PM EST WEDNESDAY FOR LSZ267.
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ265-266.
GALE WARNING FROM 4 AM TO 6 PM EST WEDNESDAY FOR LSZ263>266.
GALE WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 9 AM EST
/8 AM CST/ WEDNESDAY FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...KEC
LONG TERM...SRF
AVIATION...JLA
MARINE...KEC
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1207 PM CST TUE DEC 15 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 316 AM CST Tue Dec 15 2015
Clouds and resultant temps are the primary concern for today. Low
clouds have blanketed most of the CWA during the predawn hours,
although low cloud satellite imagery indicates that the edge of
this cloudiness is slowly working northeast across the Ozarks.
Extrapolation of this clearing line suggests the edge of of the
clouds will stretch from just south of KCOU to just north of FAM
by 12z. Latest HRRR sky cover forecasts have picked up on this
trend, but it also wants to redevelop some cloudiness over the
eastern Ozarks during the morning, which may be an indication of
some redevelopment of fog and stratus in areas that clear early
today.
In any event, increasing southeast flow ahead of next system
should cause fairly rapid northward clearing/erosion of this low
cloudiness during the afternoon over about the southeast half of
the CWA, with the expectation that the edge of the clouds will be
roughly from KMYJ-KSTL-KSLO by mid afternoon.
Obviously, high temps will be highly dependent on the exact
clouds trends. Generally went towards the warmest MAV guidance
over our southwest counties while leaning to the cooler MET
numbers over the northeast part of our CWA. This yields a tight
temp gradient of about 15 degrees from north to south across the
FA...which seems appropriate for this situation.
Truett
.LONG TERM: (Tonight through Monday)
Issued at 316 AM CST Tue Dec 15 2015
A large low pressure system over the central plains will lift
northeastward tonight, bringing a chance of rain to parts of
MO/IL after midnight. The trailing cold front then moves across
the CWA on Wed and Wed night while the parent low pressure system
begins to occlude over IA/MN/WI. There are some hints that a
smaller secondary vort max may move through the base of the
trough and pass through AR on Wed night and Thu, but no impact is
expected for the LSX CWA attm. Temperatures on Thu and Fri will
be closer to seasonal values compared to the record-setting warm
temperatures over the last few days.
Meanwhile, a separate and distinct vort max dives southeastward
out of BC on Wed and reinforces the trough over the central CONUS
on Thu. A couple of vorticity maxima are expected to move across
the area on Thu night into Fri, but no pcpn is expected from
these features attm because moisture will have been shunted off
to the east by the previous system. Skies may be slow to clear
towards the end of the week due to persistent cyclonic flow aloft
through early Friday evening.
By 12z Sat, a surface ridge axis will be centered over central
MO, and both the surface high pressure center and an upper ridge
will be shifting eastward during the day. This will bring a
return of southerly to southwesterly flow across the CWA on Sat
night and especially on Sun which will contribute to a
significant warm-up. Another low pressure system is expected to
move across the area early next, bringing a chance of rain and
perhaps some isolated thunderstorms to the area.
Kanofsky
&&
.AVIATION: (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 1146 AM CST Tue Dec 15 2015
Primary concern for today is low ceilings across much of the area.
Seeing erosion in the stratus from the southwest...however moist
low level flow from the southeast is fighting with the clearing.
Think the clearing will continue from the southwest, but may slow
as it encounters deeper moisture...and it may not get much further
north than a line from KIRK to KSTL to KSLO before 00Z. A strong
low pressure system will move north of the region tonight. Showers
will precede the cold front associated with the low...and ceilings
will likely be MVFR...probably with some areas of IFR as well.
Cooler and much drier air will move in behind the front on
Wednesday which should finally scour out the low level moisture.
Specifics for KSTL:
Watching low clouds trying to clear from the southwest very
closely this afternoon. Am concerned that cool moist southeast
flow will keep stratus around longer than currently forecast, but
the latest satellite trends do indicate that the clouds should
scatter out around 22Z. Once ceilings do scatter out, VFR
conditions should prevail until late this evening or overnight
when showers will develop ahead of the cold front. May see
conditions drop down to MVFR with the showers and the front...but
prefered to be optomistic at this time. Gusty southwest flow will
prevail Wednesday behind the front which will cause crosswind
issues on the main runways.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
544 AM CST TUE DEC 15 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 316 AM CST Tue Dec 15 2015
Clouds and resultant temps are the primary concern for today. Low
clouds have blanketed most of the CWA during the predawn hours,
although low cloud satellite imagery indicates that the edge of
this cloudiness is slowly working northeast across the Ozarks.
Extrapolation of this clearing line suggests the edge of of the
clouds will stretch from just south of KCOU to just north of FAM
by 12z. Latest HRRR sky cover forecasts have picked up on this
trend, but it also wants to redevelop some cloudiness over the
eastern Ozarks during the morning, which may be an indication of
some redevelopment of fog and stratus in areas that clear early
today.
In any event, increasing southeast flow ahead of next system
should cause fairly rapid northward clearing/erosion of this low
cloudiness during the afternoon over about the southeast half of
the CWA, with the expectation that the edge of the clouds will be
roughly from KMYJ-KSTL-KSLO by mid afternoon.
Obviously, high temps will be highly dependent on the exact
clouds trends. Generally went towards the warmest MAV guidance
over our southwest counties while leaning to the cooler MET
numbers over the northeast part of our CWA. This yields a tight
temp gradient of about 15 degrees from north to south across the
FA...which seems appropriate for this situation.
Truett
.LONG TERM: (Tonight through Monday)
Issued at 316 AM CST Tue Dec 15 2015
A large low pressure system over the central plains will lift
northeastward tonight, bringing a chance of rain to parts of
MO/IL after midnight. The trailing cold front then moves across
the CWA on Wed and Wed night while the parent low pressure system
begins to occlude over IA/MN/WI. There are some hints that a
smaller secondary vort max may move through the base of the
trough and pass through AR on Wed night and Thu, but no impact is
expected for the LSX CWA attm. Temperatures on Thu and Fri will
be closer to seasonal values compared to the record-setting warm
temperatures over the last few days.
Meanwhile, a separate and distinct vort max dives southeastward
out of BC on Wed and reinforces the trough over the central CONUS
on Thu. A couple of vorticity maxima are expected to move across
the area on Thu night into Fri, but no pcpn is expected from
these features attm because moisture will have been shunted off
to the east by the previous system. Skies may be slow to clear
towards the end of the week due to persistent cyclonic flow aloft
through early Friday evening.
By 12z Sat, a surface ridge axis will be centered over central
MO, and both the surface high pressure center and an upper ridge
will be shifting eastward during the day. This will bring a
return of southerly to southwesterly flow across the CWA on Sat
night and especially on Sun which will contribute to a
significant warm-up. Another low pressure system is expected to
move across the area early next, bringing a chance of rain and
perhaps some isolated thunderstorms to the area.
Kanofsky
&&
.AVIATION: (For the 12z TAFs through 12z Wednesday Morning)
Issued at 528 AM CST Tue Dec 15 2015
Clearing trend over eastern Ozarks has come to a screeching halt
over the past several hours, and in fact cloud deck has
retrograted to the southwest. This seems to be in response to
boundary layer flow becoming more northerly as surface ridge
builds into the region, and a trend that has been picked up by
the last few runs of the HRRR. So, it appears that low end MVFR
and IFR cigs will dominate the entire CWA throughout the morning
hours. With the increasing southerly component to the low level
flow, still expect the clearing to surge north during the
afternoon, first reaching the KCOU area by early afternoon and
then arriving in the STL Metro in the 21-23z time frame. At KUIN,
it appears MVFR cigs will dominate throughout the afternoon and
into the evening, with cigs finally increasing above 3000 feet
later this evening as increasing southerly winds finally erodes
the low level moisture.
Specifics for KSTL: Ceilings of 800-1200 feet are expected
through late morning, with cigs of 1200-1500 feet then holding
tough over the area until late in the afternoon when the edge of
the cloudiness pushes across the area and scatters out the low
deck.
Truett
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
355 AM CST TUE DEC 15 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 316 AM CST Tue Dec 15 2015
Clouds and resultant temps are the primary concern for today. Low
clouds have blanketed most of the CWA during the predawn hours,
although low cloud satellite imagery indicates that the edge of
this cloudiness is slowly working northeast across the Ozarks.
Extrapolation of this clearing line suggests the edge of of the
clouds will stretch from just south of KCOU to just north of FAM
by 12z. Latest HRRR sky cover forecasts have picked up on this
trend, but it also wants to redevelop some cloudiness over the
eastern Ozarks during the morning, which may be an indication of
some redevelopment of fog and stratus in areas that clear early
today.
In any event, increasing southeast flow ahead of next system
should cause fairly rapid northward clearing/erosion of this low
cloudiness during the afternoon over about the southeast half of
the CWA, with the expectation that the edge of the clouds will be
roughly from KMYJ-KSTL-KSLO by mid afternoon.
Obviously, high temps will be highly dependent on the exact
clouds trends. Generally went towards the warmest MAV guidance
over our southwest counties while leaning to the cooler MET
numbers over the northeast part of our CWA. This yields a tight
temp gradient of about 15 degrees from north to south across the
FA...which seems appropriate for this situation.
Truett
.LONG TERM: (Tonight through Monday)
Issued at 316 AM CST Tue Dec 15 2015
A large low pressure system over the central plains will lift
northeastward tonight, bringing a chance of rain to parts of
MO/IL after midnight. The trailing cold front then moves across
the CWA on Wed and Wed night while the parent low pressure system
begins to occlude over IA/MN/WI. There are some hints that a
smaller secondary vort max may move through the base of the
trough and pass through AR on Wed night and Thu, but no impact is
expected for the LSX CWA attm. Temperatures on Thu and Fri will
be closer to seasonal values compared to the record-setting warm
temperatures over the last few days.
Meanwhile, a separate and distinct vort max dives southeastward
out of BC on Wed and reinforces the trough over the central CONUS
on Thu. A couple of vorticity maxima are expected to move across
the area on Thu night into Fri, but no pcpn is expected from
these features attm because moisture will have been shunted off
to the east by the previous system. Skies may be slow to clear
towards the end of the week due to persistent cyclonic flow aloft
through early Friday evening.
By 12z Sat, a surface ridge axis will be centered over central
MO, and both the surface high pressure center and an upper ridge
will be shifting eastward during the day. This will bring a
return of southerly to southwesterly flow across the CWA on Sat
night and especially on Sun which will contribute to a
significant warm-up. Another low pressure system is expected to
move across the area early next, bringing a chance of rain and
perhaps some isolated thunderstorms to the area.
Kanofsky
&&
.AVIATION: (For the 06z TAFs through 06z Tuesday Night)
Issued at 1133 PM CST Mon Dec 14 2015
Not many changes to the prev TAFs. Still expect clouds to remain
in place overnight and thru the morning hours. Believe IFR cigs
will advect into the region as the ridge moves over the area.
The srn edge of the cloud deck over swrn MO does appear to be
moving newd, which may allow COU to sct out briefly. However, even
if this occurs, expect either FG or ST to develop and build back
into the area. Winds will become sely as the ridge moves E of each
terminal. Lots of questions regarding clouds Tues evening/night,
which will depend on if/when clouds break up Tues afternoon.
Tilly
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
353 PM CST TUE DEC 15 2015
.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 338 PM CST TUE DEC 15 2015
FORECAST CONCERNS THROUGH WEDNESDAY WILL BE HOW FAR NORTH THE
DRYSLOT MAKES IT...PRECIPITATION TYPE ACROSS THE FORECAST
AREA...ALONG WITH EXTENT OF FREEZING PRECIPITATION...SNOW
ACCUMULATIONS AND GUSTY WINDS RELATED TO THE STORM SYSTEM MOVING
THROUGH THE HIGH PLAINS.
SURFACE LOW PRESSURE WAS LOCATED OVER EASTERN COLORADO THIS MORNING
WITH EASTERLY FLOW...FOG...AND DRIZZLE ACROSS THE FORECAST AREA.
SURFACE TEMPERATURES WERE MOSTLY AT OR ABOVE FREEZING. ON THE EDGE
OF THE PRECIPITATION SHIELD NEAR NELIGH AND ROYAL...THEY PICKED UP A
HALF AN INCH TO 1 INCH OF WET SNOW BETWEEN 4AM AND 7AM...BUT HAD
SWITCHED OVER THE DRIZZLE/FREEZING DRIZZLE.
THE 12Z OAX SOUNDING WAS SATURATED IN THE LOWEST 2500FT WITH 0.36
PWAT. SURFACE TEMPERATURES WERE ABOVE FREEZING...HOWEVER ABOVE
800FT...TEMPERATURES WERE BELOW FREEZING.
THIS AFTERNOON...THERE IS A 45KT H85 WIND MAX MOVING THROUGH WITH
STRONG WARM ADVECTION THIS SHOULD LIFT ONE AREA OF PRECIPITATION
INTO SOUTH DAKOTA.
BY 00Z THIS EVENING...THE SURFACE LOW PRESSURE SYSTEM IS FORECAST TO
BE NEAR THE KANSAS/NEBRASKA BORDER WITH THE CLOSED H5 LOW OVER
CENTRAL NEBRASKA. THE FORECAST AREA THERMAL PROFILE IS STILL
MILD...HOWEVER THE COLD AIR IS PRESENT IN NORTHEAST NEBRASKA. THE
H85 TEMPERATURES ARE FORECAST TO VARY FROM 0 TO -4C IN NORTHEAST
NEBRASKA...WITH MILDER 0 TO +4 DEG C FARTHER SOUTHEAST. THE
-10 DEG C H7 TEMPERATURES ARE PROGRESSING EASTWARD. MEANWHILE...A
DRY SLOT IF WORKING FROM SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
THROUGH 06Z...LAPSE RATES STEEPEN...FRONTOGENESIS INCREASES OVER
NORTHEAST NEBRASKA...AND THE COLD POCKET RESIDES OVER THE
NORTHWESTERN HALF OF THE FORECAST AREA...ALONG WITH THIS AREA
BEING SATURATED...THESE CONDITIONS CONTINUE THROUGH 12Z FOR
NORTHEAST NEBRASKA AS THE STORM SYSTEM/SURFACE LOW TRACKS ACROSS
EAST CENTRAL/NORTHEAST NEBRASKA INTO SOUTHERN MINNESOTA. SPECIFIC
HUMIDITY VALUES ARE 2 TO 3 G/KG...WITH 3 TO 6 HRS FAVORABLE
LIFT/DEEP SATURATION. THE HRRR EXP SHOWS THAT THE SNOW INCREASES
IN NORTHEAST NEBRASKA AFTER 04Z...AND LASTS INTO WEDNESDAY
MORNING. THE RAP IS SUPPORTIVE IN TYING IN DECENT H85 TRANSPORT OF
MOISTURE FROM THE GULF...ACROSS MISSOURI...INTO IOWA...AND IN A
BAND INTO NORTHEAST NEBRASKA. THIS PATTERN SETS THE STAGE FOR A
FRONTGENETIC BAND OF SNOW TO DEVELOP IN NORTHEAST NEBRASKA
OVERNIGHT.
THE NORTHEAST PART OF THE FORECAST SHOULD BEGIN TO SEE SNOW
DEVELOP WITH LIGHT RAIN...DRIZZLE...FOG FOR THE REST OF THE AREA.
AS THE SURFACE LOW TRACKS NORTHEAST...SHOULD SEE SNOW CONTINUE
ACROSS PARTS OF NORTHEAST NEBRASKA AND MAY BE HEAVY FOR A COUPLE
OF HOURS WITH THE STRONGER FRONTOGENETIC FORCING. THE SNOW
CONTINUES TO WRAP AROUND THE SYSTEM AFTER 09Z AS THE NORTHWEST
WINDS INCREASE...HOWEVER THE STORM QUICKLY LIFTS NORTHEAST.
WILL NEED TO MONITOR THE DEVELOPMENT OF THIS ENHANCED BAND OF SNOW
AS IT MOVES ACROSS CENTRAL NEBRASKA INTO NORTHEAST NEBRASKA. DO
INCLUDE 2 TO 4 INCHES OF SNOW IN NORTHEAST NEBRASKA AND HAVE A
WINTER WEATHER ADVISORY FOR THE SNOW AND BLOWING SNOW WITH THE
GUSTY WINDS. DID DISCUSS WITH WWD ABOUT POTENTIAL 6 INCH AMOUNTS.
TOUGH TO PIN DOWN...HOWEVER 4KM WRF/NAM AND OTHER MODELS SHOW
POTENTIAL FOR AN ENHANCED AREA.
TEMPERATURES WILL BE COLD ALOFT...THUS SOME LIGHT SNOW AND
FLURRIES WHEREVER CLOUDS ARE SUPPORTED AS THE COLD AIR ADVECTION
CONTINUES WEDNESDAY AFTERNOON. NORTHWEST WINDS 15 TO 30 MPH...WITH
THE STRONGEST WINDS IN NORTHEAST NEBRASKA AND WEST CENTRAL IOWA.
HIGHS IN THE UPPER 20S TO LOWER 30S WEDNESDAY.
CYCLONIC FLOW WITH SOME ADDITIONAL FLURRIES POSSIBLE INTO THURSDAY
DEPENDING ON CLOUD COVER. HIGHS THURSDAY AND FRIDAY SIMILAR TO
WEDNESDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 338 PM CST TUE DEC 15 2015
THE RIDGE OVER THE ROCKIES SHIFTS INTO THE PLAINS FOR SATURDAY.
SUNDAY...A H5 TROUGH OVER THE ROCKIES BREAKS THE RIDGE DOWN...WITH
A FRONT MOVING ACROSS THE FORECAST AREA INTO SUNDAY NIGHT. EC/GFS
ARE MAINLY DRY...HOWEVER THE GFS IS COLDER WITH A LITTLE LIGHT
SNOW POSSIBLE SUNDAY AFTERNOON/SUNDAY NIGHT IN NORTHEAST NEBRASKA.
THE GFS WASHES OUT THE NEXT FRONT MONDAY NIGHT...HOWEVER A FRONT
IN THE AREA COULD GENERATE SOME SHOWERS IN WESTERN IOWA TUESDAY.
TEMPERATURES SATURDAY THROUGH TUESDAY REMAIN ABOVE NORMAL.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1130 AM CST TUE DEC 15 2015
AREA OF CLEARING DOWN ACROSS KS WILL LIKELY LIFT INTO SERN NE
LATER THIS AFTN...WITH VFR CONDITIONS LIKELY MOVING INTO THE THE
KLNK AREA AND THEN LASTING PART OF THE EVENING. MOISTURE SHOULD
WRAP BACK IN THOUGH LATER TONIGHT...REDUCING CONDITIONS BACK TO
MVFR. SIMILAR SITUATION EXPECTED FOR KOMA...BUT MORE IN THE
EVENING. DRY SLOT DEPICTED FAIRLY WELL BE EXPERIMENTAL HRRR CLOUD
AND LOW LEVEL RH FCSTS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR NEZ011-016.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO NOON CST
WEDNESDAY FOR NEZ012-017.
IA...NONE.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1130 AM CST TUE DEC 15 2015
.UPDATE...
ISSUED AT 1130 AM CST TUE DEC 15 2015
RATHER IMPRESSIVE CLOSED LOW AT 500 MB WAS OVER THE ERN CO/NWRN KS
BORDER AREA LATE THIS MORNING. 12 HOUR HEIGHT FALLS WERE ESTIMATED
TO BE UP TO 200 METERS AT 500 MB AT 12Z. DECENT 300 MB JET NOTED
SOUTH OF THE LOW FROM SONORA MEXICO INTO THE TX PNHDL. THIS LOW
WILL TRACK NEWD THIS AFTN AND TONIGHT...PROBABLY REACHING ERN SD
BY 12Z WED. THIS WILL BE ALONG FAIRLY TIGHT BAROCLINIC ZONE...WITH
SOME FRONTOGENETICAL FORCING LEADING TO A BAND OF SNOW TONIGHT.
PRIOR TO THAT...THIS AFTN...WARM ADVECTION WING TYPE LIFT WILL
MOVE THROUGH THE AREA. THIS WILL MAINLY AFFECT NERN NE BUT SOME
LIGHT PCPN...DRIZZLE OR LIGHT RAIN...IS POSSIBLE EVEN ACROSS
ECNTRL NE INTO PARTS OF WRN IA.
TWEAKED FCST A BIT EARLIER THIS MORNING AND WILL DO SO AT LEAST
ONE MORE TIME BEFORE NOON...THEN AGAIN BETWEEN 1 AND 2 PM FOR
THE REST OF TODAY.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 358 AM CST TUE DEC 15 2015
SURFACE LOW PRESSURE CURRENTLY OVER NORTHEAST COLORADO WILL TRACK
TO SOUTHERN MINNESOTA BY WEDNESDAY MORNING. THIS SYSTEM HAS SOME
BITE TO IT...THOUGH MOST OF THE EFFECTS WILL BE FOCUSED OVER NORTH
CENTRAL NEBRASKA AND MUCH OF THE DAKOTAS INTO NORTHERN MINNESOTA.
FOR EASTERN NEBRASKA AND WESTERN IOWA THE MAIN CONCERN WITH THIS
SYSTEM WILL BE PRECIPITATION TYPE. OVERALL MOISTURE PROFILES ARE
SOMEWHAT LACKING IN DEPTH. AT LEAST INITIALLY MOST OF THE MOISTURE
IS BELOW THE PREFERRED SNOW GROWTH REGION...THUS EXPECT DRIZZLE
OR FREEZING DRIZZLE AS LARGE SCALE LIFT MOVES INTO THE AREA
THROUGHOUT THE DAY TODAY. ACROSS NORTHEAST NEBRASKA...CLOSER TO
THE DEEP SYSTEM MOISTURE ALONG WITH ACCESS TO COLDER AIR...MODEST
SNOW ACCUMULATIONS ARE POSSIBLE. RIGHT NOW WE ARE ANTICIPATING 2
TO 4 INCHES OF SNOW THROUGH TONIGHT OVER PORTIONS OF
KNOX...ANTELOPE AND WESTERN CEDAR COUNTIES. PRECIPITATION SHOULD
END EARLY WEDNESDAY MORNING WITH DRY WEATHER EXPECTED THEREAFTER.
THE ARRIVAL OF THIS SYSTEM ALSO SIGNALS AN AIRMASS CHANGE TO MUCH
COLDER AIR. ABOVE NORMAL HIGH TEMPERATURES ARE EXPECTED
TODAY...SOME 5 TO 10 DEGREES ABOVE NORMAL. FOR WEDNESDAY AND
THURSDAY DAYTIME HIGHS WILL STRUGGLE TO CLIMB ABOVE FREEZING AS
850MB TEMPERATURES DROP TO -8 TO -10 CELSIUS.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 358 AM CST TUE DEC 15 2015
THIS FORECAST PERIOD STARTS OFF COLD AS WE ARE STILL UNDER A MUCH
COLDER AIRMASS THAN WE WERE USED TO. TEMPERATURES WILL ACTUALLY BE
NEAR NORMAL FOR FRIDAY WITH DAYTIME HIGHS IN THE UPPER 20S NORTH
TO THE MID 30S SOUTH. NO SENSIBLE WEATHER TO SPEAK OF THROUGH THE
WEEKEND AS UPPER LEVEL HIGH PRESSURE DOMINATES. UNDER THESE RISING
HEIGHTS EXPECT THE AIRMASS TO WARM SIGNIFICANTLY. 850MB
TEMPERATURES ARE FORECAST OR RISE TO NEAR 10 CELSIUS BY SUNDAY.
THIS SHOULD SUPPORT DAYTIME HIGHS IN THE 40S AND POSSIBLY INTO THE
LOW 50S FOR SATURDAY AND ESPECIALLY SUNDAY.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1130 AM CST TUE DEC 15 2015
AREA OF CLEARING DOWN ACROSS KS WILL LIKELY LIFT INTO SERN NE
LATER THIS AFTN...WITH VFR CONDITIONS LIKELY MOVING INTO THE THE
KLNK AREA AND THEN LASTING PART OF THE EVENING. MOISTURE SHOULD
WRAP BACK IN THOUGH LATER TONIGHT...REDUCING CONDITIONS BACK TO
MVFR. SIMILAR SITUATION EXPECTED FOR KOMA...BUT MORE IN THE
EVENING. DRY SLOT DEPICTED FAIRLY WELL BE EXPERIMENTAL HRRR CLOUD
AND LOW LEVEL RH FCSTS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...MILLER
SHORT TERM...PEARSON
LONG TERM...PEARSON
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1000 PM PST MON DEC 14 2015
.SYNOPSIS...NORTHERLY FLOW WILL RESULT IN COLD CONDITIONS THROUGH
THURSDAY. TEMPERATURES WILL START TO MODERATE BACK CLOSER TO NORMAL
ON FRIDAY AS HIGH PRESSURE ALOFT BUILDS BACK INTO THE AREA. A FEW
SYSTEMS LOOK TO SWEEP ACROSS THE AREA BETWEEN SATURDAY NIGHT AND
MONDAY BRINGING MORE CLOUDS AND THE POSSIBILITY OF PRECIPITATION.
&&
.UPDATE...CLOUDS HAVE GENERALLY BEEN DISSIPATING ACROSS AREAS AWAY
FROM LINCOLN...SOUTHERN NYE AND NORTHERN MOHAVE COUNTIES. WENT
AHEAD AND MADE A FEW ADJUSTMENTS TO THE GRIDS TO REFLECT CURRENT
TRENDS. EVERYTHING ELSE IN GOOD SHAPE.
&&
PREV DISCUSSION
340 PM PST MON DEC 14 2015
.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT.
LINGERING LOW AND MID-LEVEL MOISTURE AND ENERGY DIVING DOWN THE BACK
SIDE OF DEPARTING MID/UPPER TROUGH ARE STILL KEEPING QUITE A BIT OF
CLOUDS AROUND ACROSS MOHAVE, CLARK, LINCOLN AND CENTRAL NYE
COUNTIES. RADAR STILL SHOWS A FEW WEAK RETURNS ACROSS THE AREA AND
WE HAVE HAD A FEW REPORTS OF LIGHT SHOWERS. SOME OF THE ACTIVITY IS
LOW-TOPPED ENOUGH THAT THE RADAR IS OVERSHOOTING IT AS IS THE CASE
AT COLORADO CITY WHERE LIGHT SNOW IS STILL BEING REPORTED BY THE
AWOS. MOST OF THIS ACTIVITY SHOULD GO AWAY IN THE NEXT 2-3 HOURS
WITH THE LOSS OF ANY DAYTIME HEATING AS THIS WILL HELP THE
ATMOSPHERE TO STABILIZE AT BIT MORE AS WELL. THE HRRR SUPPORTS THIS
GENERAL TREND.
OTHERWISE, THE COLD IS IN CONTROL THROUGH WEDNESDAY NIGHT AS A
NORTHWEST FLOW ALOFT DOMINATES ACROSS THE AREA. 700 MB TEMPS OF -12C
ARE EXPECTED TO BE IN PLACE TONIGHT INTO TUESDAY ACROSS THE AREA PER
THE 12Z OPERATIONAL RUNS OF THE ECMWF AND GFS AND EVEN BY WEDNESDAY
MORNING MODIFY TO -8C. CLOUDS AND WIND WILL KEEP TEMPS UP SOME
TONIGHT THOUGH MANY SPOTS SAW FRESH SNOW AND STILL HAVE IT ON THE
GROUND SO LOW TEMPS WERE DROPPED SIGNIFICANTLY IN THESE AREAS,
ESPECIALLY IN THE HIGHER TERRAIN OF MOHAVE COUNTY AND ON MOUNT
CHARLESTON. TOMORROW NIGHT AND WEDNESDAY NIGHT WILL BE EVEN COLDER
AS WE LOOSE MUCH OF OUR CLOUD COVER. A HARD FREEZE WATCH WAS POSTED
FOR BOTH NIGHTS FOR THE KINGMAN-GOLDEN VALLEY-DOLAN SPRINGS AREA AS
LOWS DROP INTO THE TEENS OR CLOSE TO 20 DEGREES. FOR WEDNESDAY
NIGHT, A FREEZE WATCH WAS POSTED FOR THE POTENTIAL FIRST FREEZE OF
THE SEASON FOR AREAS AWAY FROM THE WATERFRONT IN BULLHEAD CITY AND
LAKE HAVASU CITY AS WELL AS NEEDLES AND ADJACENT SOUTHEAST PARTS OF
SAN BERNARDINO COUNTY. BIAS CORRECTED GUIDANCE WAS WAY TOO WARM AND
THUS LOWS WERE TRENDED TOWARD AN AVERAGE OF STATISTICAL GUIDANCE
WHICH WAS COLDER. THERE MAY BE SOME HIGH CLOUDS THAT RETURN ACROSS
THE AREA ON WEDNESDAY BUT THESE LOOK RELATIVELY THIN.
.LONG TERM...THURSDAY THROUGH MONDAY.
AN UPPER RIDGE WILL BRIEFLY TRAVERSE THE AREA THURSDAY THROUGH
THURSDAY NIGHT. DRY CONDITIONS ARE EXPECTED BUT THERE WILL BE SOME
HIGH CLOUDS MAINLY ACROSS THE NORTHERN HALF OF THE CWA. WINDS WILL
MAINLY BE LIGHT BUT THERE COULD BE A BIT OF A NORTHERLY WIND DOWN
THE COLORADO RIVER. TEMPERATURES WILL REMAIN RATHER COOL.
THE MODELS ARE IN GOOD AGREEMENT FOR FRIDAY THROUGH SATURDAY
DEPICTING A GRADUALLY INCREASING SOUTHWEST FLOW OVER THE FORECAST
AREA AS THE NEXT PACIFIC TROUGH MOVES TO THE NORTHERN CALIFORNIA
COAST BY LATE SATURDAY. THE AREA SHOULD REMAIN DRY ALTHOUGH THERE
WILL BE AN INCREASE IN MAINLY HIGH CLOUDS SATURDAY AFTERNOON. WE
SHOULD ALSO SEE AN INCREASE IN SOUTHERLY WINDS SATURDAY AFTERNOON
ACROSS MAINLY INYO...ESMERALDA AND CENTRAL NYE COUNTIES.
THERE IS MUCH LESS CONFIDENCE IN THE FORECAST FOR SUNDAY THROUGH
MONDAY. THE PATTERN NOW LOOKS MUCH MORE PROGRESSIVE THAN YESTERDAY
WITH A COUPLE OF SHORTWAVES POTENTIALLY IMPACTING THE AREA. THE
MODELS DIFFER WITH TIMING AND DEPTH OF THESE SHORTWAVES AND ALSO
DIFFER WITH PRECIPITATION PLACEMENT THROUGH THE TWO DAY PERIOD.
GENERALLY IT LOOKS UNSETTLED AND REMAINING COOL. I CHOSE TO GO WITH
A BROAD BRUSHED APPROACH FOR NOW INDICATING A SLIGHT CHANCE OF
PRECIPITATION JUST ABOUT ALL AREAS SUNDAY THROUGH MONDAY WITH
SOMEWHAT HIGHER POPS IN THE MOUNTAINS. HOPEFULLY WE WILL BE ABLE TO
FINE TUNE THINGS AFTER ANOTHER MODEL RUN OR TWO.
&&
.AVIATION...FOR MCCARRAN...NORTHWEST WINDS GUSTING 25-35 KTS ARE
WILL BEGIN TO DECREASE THIS EVENING. CIGS REMAINING MAINLY ABOVE 10K
FEET. OVERNIGHT WIND DIRECTION COULD VARY BETWEEN NORTHWEST AND
SOUTHWEST AT TIMES AFTER 03Z...BUT ARE EXPECTED TO PREDOMINANTLY
FAVOR A NORTHWEST DIRECTION. FOR TUESDAY AND WEDNESDAY...EXPECT
WINDS TO CONTINUE TO FAVOR A NORTHERLY DIRECTION BETWEEN 330 AND
030...GRADUALLY DECREASING IN STRENGTH. THE NEXT STORM SYSTEM WILL
MOVE THROUGH THE REGION NEXT WEEKEND.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...NORTHWEST WINDS OF 15-25 KTS WITH GUSTS 25-35 KTS
ACROSS MUCH OF THE REGION WILL BEGIN TO DECREASE THIS EVENING.
ISOLATED RAIN AND SNOW SHOWERS WILL TAPER OFF AS WELL WITH CIGS
IMPROVING TO ABOVE 10K FEET IN MOST AREAS. WINDS WILL DECREASE
TUESDAY AND WEDNESDAY...BUT WILL CONTINUE TO FAVOR A NORTHERLY
DIRECTION. THE NEXT STORM SYSTEM WILL MOVE THROUGH THE REGION NEXT
WEEKEND.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE...GORELOW
SHORT TERM...STACHELSKI
LONG TERM...HARRISON
AVIATION...WOLCOTT
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1147 PM CST MON DEC 14 2015
.UPDATE...
ISSUED AT 1147 PM CST MON DEC 14 2015
LATEST SURFACE OBSERVATIONS INDICATING LIGHT FREEZING DRIZZLE AT
MINOT AND BISMARCK WHICH IS BEING GENERATED DUE TO VERTICAL
MOTION WITHIN THE SATURATED LOW LEVEL AIR MASS WARMER THAN -10C.
BUFKIT SOUNDINGS CONTINUE TO SHOW THIS AND PREVIOUS FORECASTS HAVE
HAD THIS HANDLED WELL. BUFKIT SOUNDINGS SHOW THIS THREAT WILL
CONTINUE INTO TUESDAY AFTERNOON ACROSS CENTRAL NORTH DAKOTA. WATER
VAPOR SHOWS THE UPPER LOW SHIFTING/TRANSLATING ITS ENERGY FROM
EASTERN UTAH INTO CENTRAL COLORADO EARLY THIS MORNING. A COUPLE OF
WEAK SHORTWAVES OUT AHEAD OF THE MAIN UPPER LOW ARE MOVING NORTH
ALONG THE MONTANA/NORTH DAKOTA BORDER. THIS CONTINUES TO RESULT
IN POCKETS OF LIGHT SNOW FROM WILLISTON SOUTH TO DICKINSON. EXPECT
THIS TO CONTINUE OVERNIGHT.
MAIN FOCUS WILL BE SNOWFALL TOTALS AND RESULTANT DECISIONS TO
CURRENT WINTER STORM WATCH. THIS WILL BE ADDRESSED IN THE NEXT
FORECAST CYCLE.
UPDATE ISSUED AT 1008 PM CST MON DEC 14 2015
GIVEN THE LACK OF CRYSTALS FORECAST TONIGHT INTO EARLY TUESDAY
AFTERNOON ACROSS CENTRAL NORTH DAKOTA WITH A DRY LAYER ABOVE THE
STRATUS LEADING TO THE SUBLIMATION OF ANY CRYSTALS BEFORE THEY
ENTER THE LOW LEVEL SUPER-COOLED WATER...ADDED A MENTION OF PATCHY
FREEZING DRIZZLE TO CENTRAL NORTH DAKOTA WITH THIS UPDATE. THIS IS
SUPPORTED BY THE 00 UTC NAM/GFS BUFR SOUNDINGS. ACROSS THE
WEST...LIGHT SNOW IS ALREADY FALLING WITH SUFFICIENT ICE CRYSTALS
FORECAST THROUGH THE NIGHT TO POSE A MUCH LOWER THREAT FOR
FREEZING DRIZZLE.
UPDATE ISSUED AT 630 PM CST MON DEC 14 2015
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE...OTHER THAN TO
BLEND TO OBSERVED TRENDS THROUGH 00 UTC. WILL CONTINUE TO MONITOR
THE FOG ACROSS SOUTHWEST NORTH DAKOTA THROUGH THE EVENING.
HOWEVER...WEBCAMS SUGGEST DENSE FOG IS RELATIVELY PATCHY WITH THE
VISIBILITY SIGNAL IN THE 22-23 UTC HRRR ITERATIONS NOT AS STRONG
TO SUPPORT DENSE FOG AS THE PAST FEW NIGHTS. PATCHY FREEZING
DRIZZLE IS ALSO POSSIBLE TONIGHT WITH A DRY LAYER ABOVE THE STRATUS.
HOWEVER...OVERALL THE THREAT IS LOWER COMPARED TO PREVIOUS
NIGHTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 300 PM CST MON DEC 14 2015
CONCERNS IN THE SHORT TERM ARE FOG FORMATION TONIGHT ALONG
WITH SOME POSSIBLE FREEZING RAIN AHEAD OF THE WINTER STORM ON
TUESDAY AFTERNOON.
AM NOT AT THIS TIME CONTEMPLATING A DENSE FOG ADVISORY
HOWEVER CONDITIONS WILL SUPPORT SOME LOW VISIBILITIES AND RIMING
ON ROADS. SOME LIGHT PRECIPITATION WILL BEGIN ACROSS THE WEST AND
SOUTH TONIGHT AND WITH A LACK OF ICE CRYSTALS ALOFT THERE COULD
BE SOME SCATTERED LIGHT FREEZING RAIN AREAS BUT LITTLE
ACCUMULATION.
ON TUESDAY...WILL UPGRADE WATCH TO AN ADVISORY ACROSS THE
SOUTHWEST AND ADD SLOPE AND HETTINGER COUNTIES TO THE ADVISORY.
SUFFICIENT UNCERTAINTY BEYOND 6 PM TUESDAY SO WILL KEEP WINTER
STORM WATCH IN EFFECT ACROSS THE SOUTH CENTRAL AND EAST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 300 PM CST
MON DEC 14 2015
THE MAIN FOCUS OF THE LONG TERM IS A WINTER STORM TUESDAY NIGHT
AND WEDNESDAY.
THE 12 UTC MODEL SUITE CONTINUES TO INDICATE WIDESPREAD SNOW ACCUMULATIONS
TUESDAY INTO WEDNESDAY. A NEGATIVELY TILTED TROUGH WILL PROPAGATE
ACROSS THE NORTHERN PLAINS TUESDAY AND WEDNESDAY. THE
GFS/ECMWF/CANADIAN/SREF/NAM ALL HAVE THE CENTER OF THE LOW TAKING A
TRACK THROUGH EASTERN SOUTH DAKOTA. THIS WOULD PUT PORTIONS OF
CENTRAL AND EASTERN NORTH DAKOTA UNDER A TROWAL AND
DEFORMATION BANDED SNOW.
HOWEVER...A NEW FEATURE THAT IS DEPICTED IN THE LATEST RUNS IS A
DRY SLOT. THE LOCATION AND INTENSITY OF THIS DRY SLOT WILL PLAY A
LARGER ROLE IN SNOW ACCUMULATIONS. AT THIS TIME THE DRY SLOT IS
DEPICTED ACROSS THE EASTERN DAKOTAS...LEAVING MOST OF CENTRAL
NORTH DAKOTA AND THE JAMES VALLEY WITH A DEFORMATION BAND OF
PRECIP. FOR THIS FORECAST UTILIZED A BLEND OF THE OPERATIONAL
MODELS. THIS IN TURN YIELDED SNOWFALL AMOUNTS OF 5 TO 6 INCHES
ACROSS THE JAMES VALLEY AND 3 TO 4 INCHES FROM MINOT...BISMARCK
AND DICKINSON. NORTHWEST NORTH DAKOTA MAY ONLY SEE A FEW INCHES.
THERE IS SOME UNCERTAINTY ON THE HIGHER SNOW AMOUNTS ACROSS THE
JAMES VALLEY DEPENDING ON THE TROWAL...DRY SLOT AND DEFORMATION
SETUP. SOLID WINTER WEATHER ADVISORY CRITERIA SNOWFALL IS
EXPECTED... HOWEVER...WILL LET THE WINTER STORM WATCH CONTINUE AS
THERE IS THE POTENTIAL FOR WINTER STORM WARNING
ACCUMULATIONS...BUT CONFIDENCE ISN`T HIGH ENOUGH TO WARRANT
PULLING THE TRIGGER ON A WARNING AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1147 PM CST MON DEC 14 2015
LIFR TO IFR CIGS CONTINUE THROUGH THIS TAF PERIOD AT ALL TERMINALS.
-FZDZ CAN BE EXPECTED OVER THE CENTRAL TERMINALS OF KMOT/KBIS/KJMS
THROUGH TUESDAY AFTERNOON. IN THE WEST...AT KISN/KDIK...EXPECT
PERIODS OF -SN/BR REDUCING VSBYS INTO THE IFR/MVFR RANGE.
WIDESPREAD SNOW WILL DEVELOP AT KBIS/KJMS BY AROUND 03Z WEDNESDAY
AND WILL CONTINUE BEYOND THIS TAF PERIOD...INTO WEDNESDAY MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR NDZ013-020-022-023-025-034>037-042-045>048-050-051.
WINTER WEATHER ADVISORY FROM 5 AM TUESDAY TO 5 PM MST WEDNESDAY
FOR NDZ040-041-043-044.
&&
$$
UPDATE...KS
SHORT TERM...WAA
LONG TERM...AJ
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1015 PM CST MON DEC 14 2015
.UPDATE...
ISSUED AT 1008 PM CST MON DEC 14 2015
GIVEN THE LACK OF CRYSTALS FORECAST TONIGHT INTO EARLY TUESDAY
AFTERNOON ACROSS CENTRAL NORTH DAKOTA WITH A DRY LAYER ABOVE THE
STRATUS LEADING TO THE SUBLIMATION OF ANY CRYSTALS BEFORE THEY
ENTER THE LOW LEVEL SUPER-COOLED WATER...ADDED A MENTION OF PATCHY
FREEZING DRIZZLE TO CENTRAL NORTH DAKOTA WITH THIS UPDATE. THIS IS
SUPPORTED BY THE 00 UTC NAM/GFS BUFR SOUNDINGS. ACROSS THE
WEST...LIGHT SNOW IS ALREADY FALLING WITH SUFFICIENT ICE CRYSTALS
FORECAST THROUGH THE NIGHT TO POSE A MUCH LOWER THREAT FOR
FREEZING DRIZZLE.
UPDATE ISSUED AT 630 PM CST MON DEC 14 2015
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE...OTHER THAN TO
BLEND TO OBSERVED TRENDS THROUGH 00 UTC. WILL CONTINUE TO MONITOR
THE FOG ACROSS SOUTHWEST NORTH DAKOTA THROUGH THE EVENING.
HOWEVER...WEBCAMS SUGGEST DENSE FOG IS RELATIVELY PATCHY WITH THE
VISIBILITY SIGNAL IN THE 22-23 UTC HRRR ITERATIONS NOT AS STRONG
TO SUPPORT DENSE FOG AS THE PAST FEW NIGHTS. PATCHY FREEZING
DRIZZLE IS ALSO POSSIBLE TONIGHT WITH A DRY LAYER ABOVE THE STRATUS.
HOWEVER...OVERALL THE THREAT IS LOWER COMPARED TO PREVIOUS
NIGHTS.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 300 PM CST MON DEC 14 2015
CONCERNS IN THE SHORT TERM ARE FOG FORMATION TONIGHT ALONG
WITH SOME POSSIBLE FREEZING RAIN AHEAD OF THE WINTER STORM ON
TUESDAY AFTERNOON.
AM NOT AT THIS TIME CONTEMPLATING A DENSE FOG ADVISORY
HOWEVER CONDITIONS WILL SUPPORT SOME LOW VISIBILITIES AND RIMING
ON ROADS. SOME LIGHT PRECIPITATION WILL BEGIN ACROSS THE WEST AND
SOUTH TONIGHT AND WITH A LACK OF ICE CRYSTALS ALOFT THERE COULD
BE SOME SCATTERED LIGHT FREEZING RAIN AREAS BUT LITTLE
ACCUMULATION.
ON TUESDAY...WILL UPGRADE WATCH TO AN ADVISORY ACROSS THE
SOUTHWEST AND ADD SLOPE AND HETTINGER COUNTIES TO THE ADVISORY.
SUFFICIENT UNCERTAINTY BEYOND 6 PM TUESDAY SO WILL KEEP WINTER
STORM WATCH IN EFFECT ACROSS THE SOUTH CENTRAL AND EAST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY) ISSUED AT 300 PM CST
MON DEC 14 2015
THE MAIN FOCUS OF THE LONG TERM IS A WINTER STORM TUESDAY NIGHT
AND WEDNESDAY.
THE 12 UTC MODEL SUITE CONTINUES TO INDICATE WIDESPREAD SNOW ACCUMULATIONS
TUESDAY INTO WEDNESDAY. A NEGATIVELY TILTED TROUGH WILL PROPAGATE
ACROSS THE NORTHERN PLAINS TUESDAY AND WEDNESDAY. THE
GFS/ECMWF/CANADIAN/SREF/NAM ALL HAVE THE CENTER OF THE LOW TAKING A
TRACK THROUGH EASTERN SOUTH DAKOTA. THIS WOULD PUT PORTIONS OF
CENTRAL AND EASTERN NORTH DAKOTA UNDER A TROWL AND
DEFORMATION BANDED SNOW.
HOWEVER...A NEW FEATURE THAT IS DEPICTED IN THE LATEST RUNS IS A
DRY SLOT. THE LOCATION AND INTENSITY OF THIS DRY SLOT WILL PLAY A
LARGER ROLE IN SNOW ACCUMULATIONS. AT THIS TIME THE DRY SLOT IS
DEPICTED ACROSS THE EASTERN DAKOTAS...LEAVING MOST OF CENTRAL
NORTH DAKOTA AND THE JAMES VALLEY WITH A DEFORMATION BAND OF
PRECIP. FOR THIS FORECAST UTILIZED A BLEND OF THE OPERATIONAL
MODELS. THIS IN TURN YIELDED SNOWFALL AMOUNTS OF 5 TO 6 INCHES
ACROSS THE JAMES VALLEY AND 3 TO 4 INCHES FROM MINOT...BISMARCK
AND DICKINSON. NORTHWEST NORTH DAKOTA MAY ONLY SEE A FEW INCHES.
THERE IS SOME UNCERTAINTY ON THE HIGHER SNOW AMOUNTS ACROSS THE
JAMES VALLEY DEPENDING ON THE TROWL...DRY SLOT AND DEFORMATION SETUP.
SOLID WINTER WEATHER ADVISORY CRITERIA SNOWFALL IS EXPECTED...
HOWEVER...WILL LET THE WINTER STORM WATCH CONTINUE AS THERE IS
THE POTENTIAL FOR WINTER STORM WARNING ACCUMULATIONS...BUT
CONFIDENCE ISN`T HIGH ENOUGH TO WARRANT PULLING THE TRIGGER ON
A WARNING AT THIS TIME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 1008 PM CST MON DEC 14 2015
WIDESPREAD IFR/LIFR CONDITIONS IN STRATUS TONIGHT THROUGH TUESDAY
ACROSS WESTERN AND CENTRAL NORTH DAKOTA. LIGHT SNOW WILL CONTINUE
ACROSS WESTERN NORTH DAKOTA TONIGHT INTO TUESDAY. WIDESPREAD SNOW
IS EXPECTED TO DEVELOP ACROSS CENTRAL NORTH DAKOTA TUESDAY LATE
AFTERNOON THROUGH WEDNESDAY. PATCHY FREEZING DRIZZLE IS POSSIBLE
CENTRAL TONIGHT THROUGH EARLY TUESDAY AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR NDZ013-020-022-023-025-034>037-042-045>048-050-051.
WINTER WEATHER ADVISORY FROM 5 AM TUESDAY TO 5 PM MST WEDNESDAY
FOR NDZ040-041-043-044.
&&
$$
UPDATE...AYD
SHORT TERM...WAA
LONG TERM...AJ
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
951 PM EST WED DEC 16 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT. WESTERLY WINDS
WILL SET UP BEHIND THE COLD FRONT. A SECONDARY COLD FRONT WILL
MOVE ACROSS THE REGION FRIDAY AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH THURSDAY/...
PRE FRONTAL SHOWERS HAVE CONTINUED THIS EVENING AHEAD OF A SURFACE
COLD FRONT WHICH IS CURRENTLY MOVING THROUGH INDIANAPOLIS. AN
UPPER LEVEL DISTURBANCE CAN ALSO BE SEEN ON WATER VAPOR THIS
EVENING EJECTING OFF TOWARDS THE NORTHEAST. ALONG AND AHEAD OF THE
DISTURBANCE WIDESPREAD SHOWERS HAVE FORMED. THE MAIN QUESTION WILL
BE WHERE EXACTLY THE UPPER LEVEL DISTURBANCE TRACKS. LATEST HRRR
AND RAP CONTINUE TO SHOW MOST OF THE PRECIP MOVING ACROSS THE
EASTERN ZONES BUT DON`T APPEAR TO BE HANDLING LATEST RADAR TRENDS
THAT WELL. HAVE GONE AHEAD AND MOVED HIGHER POPS SLIGHTLY WEST TO
ACCOUNT FOR ONGOING TRENDS.
DURING THE DAY THURSDAY MUCH COLDER 850 TEMPERATURES ARE
FORECASTED TO COME AS THE UPPER LEVEL LOW EJECTS OFF TOWARDS THE
NORTHEAST. THE GFS IS MORE PROGRESSIVE PUSHING COLDER 850 TEMPS IN
QUICKER THAN THE NAM (-2 DEGREES C LOOKS LIKELY BY THURSDAY
AFTERNOON). EVEN THOUGH TEMPERATURES WILL FEEL MUCH COLDER HIGHS
WILL BE NEAR NORMAL VALUES FOR THIS TIME OF YEAR. CLOUDS LOOK TO
ALSO WILL HANG AROUND IN THE MORNING WITH CU DEVELOPMENT EXPECTED
DURING THE AFTERNOON AS LOW LEVEL LAPSE RATES STEEPEN A BIT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
SHOWERS MAY STILL BE ONGOING IN THE SOUTHEAST COUNTIES AT THE
BEGINNING OF THE PERIOD BEFORE CLEARING OUT IN THE MORNING.
CLOUDS WILL DIMINISH BUT THEN THERE WILL PROBABLY BE SOME
REDEVELOPMENT OF STRATOCUMULUS WITH COLD AIR ADVECTION AND
HEATING. TEMPERATURES WILL LIKELY NOT RISE MUCH FROM THE MORNING
LOWS.
LONG WAVE TROUGH AXIS WILL REMAIN WEST OF THE REGION UNTIL SHORT
WAVE ENERGY MOVING THROUGH THE TROUGH CAUSES IT TO SHIFT EAST ON
FRIDAY NIGHT. THIS WILL RESULT IN A SECONDARY COLD FRONT MOVING
THROUGH THE AREA FRIDAY AFTERNOON AND EVENING. WHILE MOISTURE WILL
BE LIMITED...IT LOOKS LIKE SOME SNOW SHOWERS MAY DEVELOP AS THE
COLD FRONT AND STRONGER SHORT WAVE MOVES THROUGH. APPEARS THAT
THIS DEVELOPMENT WILL OCCUR AS THE SYSTEM IS TRACKING ACROSS THE
AREA. SO POPS INCREASE FROM WEST TO EAST FRIDAY AFTERNOON AND
THEN DIMINISH QUICKLY FRIDAY EVENING. CANNOT RULE OUT SOME
LINGERING FLURRIES ON FRIDAY NIGHT. WENT A BIT ABOVE MOS FOR LOWS
BOTH THURSDAY NIGHT AND FRIDAY NIGHT. STAYED CLOSE TO MOS FOR
FRIDAY HIGHS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
ALTHOUGH THE LONG TERM WILL START OUT DRY AN UNSETTLED WEATHER
PATTERN IS TAKING SHAPE FOR NEXT WEEK. HIGH PRESSURE WILL BE
SITUATED ACROSS THE FA ON SATURDAY BEFORE BEGINNING TO SHIFT OFF TO
THE EAST ON SUNDAY. THIS WILL ALLOW FOR A DECENT INCREASE IN HIGH
TEMPERATURE VALUES FROM SATURDAY TO SUNDAY.
WITH AN INCREASE IN CLOUDS SUNDAY NIGHT DO NOT EXPECT TEMPERATURES
TO DROP TOO MUCH OVERNIGHT. ALTHOUGH THERE ARE SOME SUBTLE TIMING
DIFFERENCES WITH THE START OF THE RAIN OVERNIGHT SUNDAY NIGHT INTO
MONDAY MORNING THERE IS GENERAL AGREEMENT WITH THE BULK OF THE
PRECIPITATION BEGINNING TO MOVE INTO THE AREA AFTER MIDNIGHT SUNDAY
NIGHT AND BEFORE SUNRISE MONDAY MORNING.
SEVERAL ROUNDS OF PRECIPITATION ARE THEN EXPECTED FROM THE SUNDAY
NIGHT INTO WEDNESDAY TIME PERIOD. TEMPERATURE PROFILES ARE
INDICATING THAT PRECIPITATION IS EXPECTED TO BE IN THE FORM OF
RAIN FOR THIS EVENT. DEPENDING ON THE WHERE THE EXACT MOISTURE
PLUMES SET UP...WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR
FLOODING DUE TO SEVERAL ROUNDS OF EXPECTED RAINFALL. OVERALL
EXPECT ABOVE NORMAL TEMPERATURES AND PRECIPITATION FOR THIS TIME
PERIOD.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
WEAK PRE FRONTAL SHOWERS CONTINUE TO PROGRESS ACROSS THE WESTERN
TAF SITES THIS EVENING WITH MAIN COLD FRONT MOVING INTO WESTERN
INDIANA CURRENTLY. WEAK UPPER LEVEL FORCING AND DRIER AIR WILL
HELP TO KEEP SHOWERS IN CHECK ACROSS THE WESTERN TAF SITES BEFORE
AN UPPER LEVEL DISTURBANCE RIDES ALONG THE FRONT ACROSS EASTERN
OHIO. MOST OF THE MORE ORGANIZED SHOWERS WILL LIKELY JUST AFFECT
KILN/ KCMH/ AND KLCK. BEHIND THE FRONT AM NOT CURRENTLY SEEING TO
MANY MVFR CIGS BUT FORECAST SOUNDINGS CONTINUE TO ADVERTISE
WIDESPREAD MVFR CIGS. TOWARDS OUR EASTERN TAF SITES WHERE MORE
MOIST AIR IS FORECASTED TO MOVE IN FROM THE SOUTH IFR CIGS ARE
POSSIBLE.
GFS IS STILL SHOWING A BRIEF TRANSITION OF RAIN TO SNOW BEHIND THE
FRONT BUT FORECAST SOUNDINGS SHOW WAY TO MUCH DRY AIR TO SUPPORT
THIS. GIVEN THE ABOVE HAVE KEPT TERMINALS ALL RAIN. THURSDAY
AFTERNOON STRONG LOW LEVEL COLD AIR ADVECTION WILL HELP TO KEEP
WINDS ABOVE 10 KTS AS STEEP LAPSE RATES WILL PROMOTE MIXING. THIS
MIXING ALONG WITH SOME LOW LEVEL MOISTURE REMAINING WILL LIKELY
KEEP SOME CU AROUND. NAM FORECAST SOUNDINGS ARE MUCH MORE
AGGRESSIVE SHOWING AN OVC DECK WHILE THE GFS ONLY SHOWS FEW AT
BEST. FOR NOW HAVE SPLIT THE DIFFERENCE BUT CAN`T COMPLETELY RULE
OUT SOME BRIEF RESTRICTIONS IN CIGS TO MVFR TOMORROW AFTERNOON.
OUTLOOK...MVFR CEILINGS POSSIBLE THURSDAY NIGHT INTO FRIDAY AND
AGAIN ON MONDAY. ISOLATED SNOW SHOWERS POSSIBLE FRIDAY AFTERNOON.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HAINES
NEAR TERM...HAINES
SHORT TERM...
LONG TERM...NOVAK
AVIATION...HAINES
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
702 AM EST TUE DEC 15 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST OF THE AREA TODAY. A RIDGE OF HIGH
PRESSURE WILL MOVE EAST ACROSS THE LOCAL AREA TONIGHT FOLLOWED BY
YET ANOTHER LOW PRESSURE SYSTEM. THE LOW WILL MOVE NORTHEAST INTO
THE WESTERN GREAT LAKES BY WEDNESDAY NIGHT FORCING A COLD FRONT
EAST ACROSS THE REGION THURSDAY MORNING. HIGH PRESSURE WILL BUILD
EAST ACROSS THE SOUTHERN GULF COAST STATES WITH A WEAK RIDGE
EXTENDING NORTH OVER THE LOCAL AREA BY FRIDAY NIGHT. A STRONGER
RIDGE WILL BUILD EAST OVER THE AREA OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A REINFORCING COLD FRONT WILL MOVE SOUTHEAST ACROSS THE AREA THIS
MORNING. THIS FEATURE SHOWS UP WELL ON RADAR UP IN MICHIGAN FROM
THE THUMB TO SOUTHERN LAKE MICHIGAN. THERE IS A POSSIBILITY THAT
THE FRONT WILL PUSH ONLY AS FAR SOUTH AS ERIE AND THEN GET SHUNTED
EAST WITH THE LOW. THEN BY THIS EVENING THE FRONT WILL GET PUSHED
A TAD FURTHER SOUTH ACROSS MANSFIELD. SO WILL KEEP MENTION OF
SLIGHT CHANCE OF SHOWERS IN ERIE FOR THIS MORNING WITH THIS
FRONTAL BOUNDARY. SOME LIGHT STUFF COULD SNEAK ACROSS PORTIONS OF
THE SOUTHEAST COUNTY WARNING AREA THIS MORNING AS WELL.
PREVIOUS DISCUSSION...
AS SURFACE LOW PRESSURE PULLS OFF TO THE
EAST LATER TODAY...A TROUGH OF LOW PRESSURE WILL EXTEND BACK OVER
THE LOWER GREAT LAKES BY THIS AFTERNOON. REMNANT SHOWER ACTIVITY
WILL PUSH EAST WITH THE LOW TODAY AS WELL. AS DRIER AIR PUSHES
INTO THE REGION...THIS SHOULD COUNTER THE EFFECTS OF THE SURFACE
TROUGH MOVING SOUTH ACROSS THE AREA. HRRR MODEL SUGGESTS SOME WEAK
PRECIPITATION ACTIVITY PUSHING SOUTH ACROSS THE LAKE BUT APPEARS
TO DISSIPATE AS IT ENCOUNTERS THE DRIER AIR OVER THE FORECAST AREA
THIS AFTERNOON. OTHERWISE...BREAKS IN THE OVERCAST WILL DEVELOP
THROUGHOUT THE DAY ALLOWING FOR SOME SUN TO POKE THROUGH THE
CLOUDS. I AM EXPECTING TEMPERATURES TO REMAIN NEARLY STEADY IN THE
MIDDLE TO UPPER 40S ACROSS THE FORECAST AREA TODAY IN THE COLD AIR
ADVECTION THAT WILL TAKE PLACE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
UPPER LEVEL PATTERN QUICKLY TRANSITIONS INTO AN EXTENSIVE RIDGE
THAT WILL BUILD EAST ACROSS THE AREA BY THIS EVENING. THE UPPER
LEVEL RIDGE BECOMES NEARLY STATIONARY ALONG THE EAST COAST INTO
THE WEEKEND. AN EXTENSIVE UPPER LEVEL LOW PRESSURE SYSTEM WILL
SLIDE SOUTHEAST AND BECOME NEARLY STATIONARY JUST WEST OF ONTARIO
CANADA BY THURSDAY NIGHT. THIS FEATURE WILL ROTATE AN EXTENSIVE
UPPER LEVEL TROUGH EAST TOWARD THE LOCAL AREA. CYCLOGENESIS AND
SLOW DEEPENING OF THE LOW PRESSURE SYSTEM WILL TAKE PLACE AS THE
LOW MOVES NORTHEAST INTO THE WESTERN GREAT LAKES AND THEN CENTRAL
ONTARIO CANADA BY THURSDAY AFTERNOON. A COLD FRONT WILL PUSH EAST
ACROSS THE AREA THURSDAY MORNING USHERING IN COLDER AIR TO THE
FORECAST AREA. THE COLDEST PUSH OF AIR REALLY DOES NOT ARRIVE
UNTIL FRIDAY MORNING. 850 MB TEMPERATURES DROP TO AROUND -10 C BY
FRIDAY MORNING. THIS WILL RESULT IN MARGINAL INSTABILITY.
EXPECTING LAKE EFFECT SNOW TO DEVELOP LATE THURSDAY NIGHT INTO
FRIDAY FOR SNOW BELT AREAS TO THE EAST. EXPECTING SOME LIGHT
ACCUMULATIONS AT THIS TIME. WILL CONTINUE TO MONITOR THE LAKE
EFFECT SNOW SITUATION FOR POSSIBLE HEADLINES. 850 MB WARM AIR
ADVECTION BEGINS TO DEVELOP LATE FRIDAY NIGHT OR SATURDAY AND
WILL GRADUALLY TAPER OFF LAKE SNOW THREAT. OTHERWISE...FAIR
WEATHER IS EXPECTED OVER THE REST OF THE FORECAST AREA.
TEMPERATURES WILL BE DROPPING ACROSS THE AREA AS STRONG COLD AIR
ADVECTION TAKES PLACE FRIDAY AND SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
LAKE EFFECT SNOW WILL LINGER IN THE SNOW BELT ON SATURDAY WITH A
WESTERLY FETCH OFF LAKE ERIE. MOISTURE DEPTH DOES DECREASE WITH THE
UPPER TROUGH AXIS ALREADY TO THE EAST BUT FAVORABLE LOW LEVEL
INSTABILITY WILL BE IN PLACE. WITH TIME...A RIDGE EXPANDS NORTH UP
THE OHIO VALLEY AND SNOW SHOULD TAPER OFF SATURDAY NIGHT.
TEMPERATURES ON SATURDAY SHOULD PEAK AROUND 30 DEGREES...RUNNING A
FEW DEGREES HIGHER NEAR THE LAKESHORE.
SOUTHWESTERLY FLOW AND WARM ADVECTION GET UNDERWAY BY SUNDAY AS THE
RIDGE STARTS TO BUILD ALOFT. TEMPERATURES WILL BE BACK IN THE LOW TO
MID 40S AGAIN BY MONDAY WITH DEEP SOUTHERLY FLOW BRINGING MOISTURE
AND A CHANCE OF RAIN FOR MONDAY AND MONDAY NIGHT.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
A TROUGH REMAINS ACROSS THE EASTERN GREAT LAKES WITH A
CONSIDERABLE STRATUS DECK IN PLACE ACROSS THE REGION. WINDS HAVE
PICKED UP OVER THE LAST HOUR AND ARE GUSTING TO 20-30 KNOTS AT
MOST SITES. THE GUSTS SHOULD START TO DROP OFF AS THE TROUGH
STARTS TO RELAX AFTER 14-15Z. EXPECTING GENERALLY MVFR CEILINGS
TODAY ALTHOUGH A BREAK IN THE CLOUDS OVER LAKE ERIE MAY ALLOW FOR
SOME BRIEF CLEARING AT CLE/ERI THIS MORNING BEFORE FILLING BACK
IN. A COLD FRONT OVER LAKE HURON IS EXPECTED TO SETTLE IN NE OH/NW
PA TONIGHT WITH CEILINGS LOWERING TO IFR. THERE IS A CHANCE OF
SEEING SOME AREAS OF FOG DEVELOP AFTER 06Z BUT NOT A LOT OF
CONFIDENCE IN THAT AT THIS POINT.
OUTLOOK...NON-VFR PROBABLE WEDNESDAY NIGHT INTO THURSDAY IN
-SHRA. NON VFR NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA FRIDAY
THRU SAT NIGHT IN LAKE EFFECT SNOW.
&&
.MARINE...
A TROUGH REMAINS ACROSS THE GREAT LAKES REGION EXTENDING
FROM LOW PRESSURE OVER SOUTHERN QUEBEC. WESTERLY WINDS WILL RANGE
FROM 15-25 KNOTS ON THE WESTERN BASIN...AND LOCALLY UP TO 30 KNOTS
ON THE EASTERN BASIN. A SMALL CRAFT ADVISORY REMAINS IN EFFECT BUT
ADJUSTED THE ENDING TIME WEST OF VERMILION TO EXPIRE AT 10 AM WHILE
IT REMAINS IN EFFECT EAST OF VERMILION UNTIL 4 PM. A RIDGE WILL
BUILD OVER THE LAKE BY THIS EVENING WITH CONDITIONS RAPIDLY
IMPROVING.
THE NEXT LOW PRESSURE SYSTEM WILL MOVE NORTHEAST ACROSS THE UPPER
GREAT LAKES FROM WEDNESDAY INTO THURSDAY. THIS SYSTEM WILL PULL A
STRONGER COLD FRONT EAST ACROSS LAKE ERIE ON WEDNESDAY NIGHT. COOLER
AIR WILL FILTER INTO THE REGION WITH A RE-ENFORCING COLD FRONT ON
FRIDAY AND WESTERLY WINDS INCREASING TO 15 TO 25 KNOTS FRIDAY INTO
SATURDAY. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED AGAIN ON THE
EAST HALF OF THE LAKE AS CONDITIONS BECOME MORE UNSTABLE AND WAVES
BUILD DOWN THE LONG FETCH OF THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
LEZ145>149.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR
LEZ142>144.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
422 AM EST TUE DEC 15 2015
.SYNOPSIS...
LOW PRESSURE WILL MOVE EAST OF THE AREA TODAY. A RIDGE OF HIGH
PRESSURE WILL MOVE EAST ACROSS THE LOCAL AREA TONIGHT FOLLOWED BY
YET ANOTHER LOW PRESSURE SYSTEM. THE LOW WILL MOVE NORTHEAST INTO
THE WESTERN GREAT LAKES BY WEDNESDAY NIGHT FORCING A COLD FRONT
EAST ACROSS THE REGION THURSDAY MORNING. HIGH PRESSURE WILL BUILD
EAST ACROSS THE SOUTHERN GULF COAST STATES WITH A WEAK RIDGE
EXTENDING NORTH OVER THE LOCAL AREA BY FRIDAY NIGHT. A STRONGER
RIDGE WILL BUILD EAST OVER THE AREA OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS SURFACE LOW PRESSURE PULLS OFF TO THE EAST LATER TODAY...A
TROUGH OF LOW PRESSURE WILL EXTEND BACK OVER THE LOWER GREAT LAKES
BY THIS AFTERNOON. REMNANT SHOWER ACTIVITY WILL PUSH EAST WITH THE
LOW TODAY AS WELL. AS DRIER AIR PUSHES INTO THE REGION...THIS
SHOULD COUNTER THE EFFECTS OF THE SURFACE TROUGH MOVING SOUTH
ACROSS THE AREA. HRRR MODEL SUGGESTS SOME WEAK PRECIPITATION
ACTIVITY PUSHING SOUTH ACROSS THE LAKE BUT APPEARS TO DISSIPATE AS
IT ENCOUNTERS THE DRIER AIR OVER THE FORECAST AREA THIS AFTERNOON.
OTHERWISE...BREAKS IN THE OVERCAST WILL DEVELOP THROUGHOUT THE DAY
ALLOWING FOR SOME SUN TO POKE THROUGH THE CLOUDS. I AM EXPECTING
TEMPERATURES TO REMAIN NEARLY STEADY IN THE MIDDLE TO UPPER 40S
ACROSS THE FORECAST AREA TODAY IN THE COLD AIR ADVECTION THAT WILL
TAKE PLACE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
UPPER LEVEL PATTERN QUICKLY TRANSITIONS INTO AN EXTENSIVE RIDGE
THAT WILL BUILD EAST ACROSS THE AREA BY THIS EVENING. THE UPPER
LEVEL RIDGE BECOMES NEARLY STATIONARY ALONG THE EAST COAST INTO
THE WEEKEND. AN EXTENSIVE UPPER LEVEL LOW PRESSURE SYSTEM WILL
SLIDE SOUTHEAST AND BECOME NEARLY STATIONARY JUST WEST OF ONTARIO
CANADA BY THURSDAY NIGHT. THIS FEATURE WILL ROTATE AN EXTENSIVE
UPPER LEVEL TROUGH EAST TOWARD THE LOCAL AREA. CYCLOGENESIS AND
SLOW DEEPENING OF THE LOW PRESSURE SYSTEM WILL TAKE PLACE AS THE
LOW MOVES NORTHEAST INTO THE WESTERN GREAT LAKES AND THEN CENTRAL
ONTARIO CANADA BY THURSDAY AFTERNOON. A COLD FRONT WILL PUSH EAST
ACROSS THE AREA THURSDAY MORNING USHERING IN COLDER AIR TO THE
FORECAST AREA. THE COLDEST PUSH OF AIR REALLY DOES NOT ARRIVE
UNTIL FRIDAY MORNING. 850 MB TEMPERATURES DROP TO AROUND -10 C BY
FRIDAY MORNING. THIS WILL RESULT IN MARGINAL INSTABILITY.
EXPECTING LAKE EFFECT SNOW TO DEVELOP LATE THURSDAY NIGHT INTO
FRIDAY FOR SNOW BELT AREAS TO THE EAST. EXPECTING SOME LIGHT
ACCUMULATIONS AT THIS TIME. WILL CONTINUE TO MONITOR THE LAKE
EFFECT SNOW SITUATION FOR POSSIBLE HEADLINES. 850 MB WARM AIR
ADVECTION BEGINS TO DEVELOP LATE FRIDAY NIGHT OR SATURDAY AND
WILL GRADUALLY TAPER OFF LAKE SNOW THREAT. OTHERWISE...FAIR
WEATHER IS EXPECTED OVER THE REST OF THE FORECAST AREA.
TEMPERATURES WILL BE DROPPING ACROSS THE AREA AS STRONG COLD AIR
ADVECTION TAKES PLACE FRIDAY AND SATURDAY MORNING.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
LAKE EFFECT SNOW WILL LINGER IN THE SNOW BELT ON SATURDAY WITH A
WESTERLY FETCH OFF LAKE ERIE. MOISTURE DEPTH DOES DECREASE WITH THE
UPPER TROUGH AXIS ALREADY TO THE EAST BUT FAVORABLE LOW LEVEL
INSTABILITY WILL BE IN PLACE. WITH TIME...A RIDGE EXPANDS NORTH UP
THE OHIO VALLEY AND SNOW SHOULD TAPER OFF SATURDAY NIGHT.
TEMPERATURES ON SATURDAY SHOULD PEAK AROUND 30 DEGREES...RUNNING A
FEW DEGREES HIGHER NEAR THE LAKESHORE.
SOUTHWESTERLY FLOW AND WARM ADVECTION GET UNDERWAY BY SUNDAY AS THE
RIDGE STARTS TO BUILD ALOFT. TEMPERATURES WILL BE BACK IN THE LOW TO
MID 40S AGAIN BY MONDAY WITH DEEP SOUTHERLY FLOW BRINGING MOISTURE
AND A CHANCE OF RAIN FOR MONDAY AND MONDAY NIGHT.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
BANDS OF SCT SHRA WILL CONTINUE TO ROTATE EAST ACROSS THE AREA
TONIGHT...WITH ONLY A LINGERING SLIGHT CHC AT ERI BY TUE MORNING.
CIGS WILL VARY FROM VFR TO MVFR IN AND AROUND THE SHRA WITH MOST
SITES SETTLING INTO MOSTLY MVFR BY LATE TONIGHT AS THE AIRMASS
COOLS. THE MODELS SHOW A LOT OF LOW LEVEL MOISTURE STAYING OVER
THE AREA TUE SO THINK MVFR STRATOCU LIKELY TO STAY TRAPPED UNDER
THE INVERSION AND PERSIST THRU THE DAY TUE AND EARLY TUE NIGHT.
SW TO WEST WINDS COULD STILL GUST 20 TO 25 KNOTS AT ERI INTO THU
AFTERNOON.
OUTLOOK...NON-VFR PROBABLE WEDNESDAY NIGHT INTO THURSDAY IN
-SHRA. NON VFR NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA FRIDAY
THRU SAT NIGHT IN LAKE EFFECT SNOW.
&&
.MARINE...
A TROUGH REMAINS ACROSS THE GREAT LAKES REGION EXTENDING
FROM LOW PRESSURE OVER SOUTHERN QUEBEC. WESTERLY WINDS WILL RANGE
FROM 15-25 KNOTS ON THE WESTERN BASIN...AND LOCALLY UP TO 30 KNOTS
ON THE EASTERN BASIN. A SMALL CRAFT ADVISORY REMAINS IN EFFECT BUT
ADJUSTED THE ENDING TIME WEST OF VERMILION TO EXPIRE AT 10 AM WHILE
IT REMAINS IN EFFECT EAST OF VERMILION UNTIL 4 PM. A RIDGE WILL
BUILD OVER THE LAKE BY THIS EVENING WITH CONDITIONS RAPIDLY
IMPROVING.
THE NEXT LOW PRESSURE SYSTEM WILL MOVE NORTHEAST ACROSS THE UPPER
GREAT LAKES FROM WEDNESDAY INTO THURSDAY. THIS SYSTEM WILL PULL A
STRONGER COLD FRONT EAST ACROSS LAKE ERIE ON WEDNESDAY NIGHT. COOLER
AIR WILL FILTER INTO THE REGION WITH A RE-ENFORCING COLD FRONT ON
FRIDAY AND WESTERLY WINDS INCREASING TO 15 TO 25 KNOTS FRIDAY INTO
SATURDAY. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED AGAIN ON THE
EAST HALF OF THE LAKE AS CONDITIONS BECOME MORE UNSTABLE AND WAVES
BUILD DOWN THE LONG FETCH OF THE LAKE.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
LEZ145>149.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THIS MORNING FOR
LEZ142>144.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KEC
AVIATION...ADAMS
MARINE...KEC
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
246 PM CST TUE DEC 15 2015
.SHORT TERM (TONIGHT THROUGH WEDNESDAY)...
LOW-END LIGHT RAIN CHANCES ARE ONGOING THIS AFTERNOON AND WILL
PERSIST THROUGH THE EARLY MORNING HOURS WEDNESDAY FOR EASTERN
ZONES AS A FRONT SLOWLY MOVES THROUGH THE AREA. OUTSIDE OF THIS
WEATHER...QUIET CONDITIONS ARE EXPECTED THROUGH TOMORROW.
A COLD FRONT IS LOCATED ACROSS THE HILL COUNTRY MOVING SOUTHEAST
THIS AFTERNOON. GIVEN THE FRONTAL MOVEMENT DURING PEAK HEATING AND
CLOUDS BREAKING UP...THE DIURNAL TEMPERATURE RISE IS MASKING THE
TEMPERATURE EFFECTS FROM THE FRONT. CLOUDS CONTINUE TO SLOWLY
CLEAR ALONG AND AHEAD OF THE FRONT WITH TEMPERATURES RISING INTO
THE MID 60S FOR THE HILL COUNTRY TO LOW AND EVEN SOME UPPER 70S
ACROSS THE I-35 CORRIDOR TO THE COASTAL PLAINS. AS A RESULT OF
THIS BETTER HEATING AND WHERE HIGHER MOISTURE CONTENT RESIDES...
SOME LIGHT RAIN SHOWERS ARE OCCURRING OVER THE COASTAL PLAINS
NORTH TOWARDS TEMPLE. THE SCATTERED SHOWERS WILL PERSIST THROUGH
THE AFTERNOON AND EVENING AHEAD OF THE FRONT MAINLY ACROSS EASTERN
LOCATIONS INTO FAYETTE...LEE...AND LAVACA COUNTIES. SHOWERS WILL
END FROM WEST TO EAST BY DAWN WEDNESDAY AS THE FRONT PUSHES
THROUGH.
EXPECT A SUNNY DAY WEDNESDAY BUT TEMPERATURES WILL BE NOTICEABLY COOLER
AS 925MB TEMPS FALL FROM NEAR 16-18C TODAY DOWN TO 10-12C
TOMORROW. BUFR SOUNDINGS ALSO INDICATE SHALLOWER MIXING HEIGHTS
AND THIS WILL RESULT IN ABOUT A 10F DEGREE COOL-OFF FROM TODAYS
HIGHS.
&&
.LONG TERM (THURSDAY THROUGH TUESDAY)...
NO HAZARDS EXPECTED MINUS A FEW FREEZING TEMPERATURES IN THE HILL
COUNTRY AS QUIET CONDITIONS PERSIST THROUGH THE LATE WEEK AND
WEEKEND. A MORE UNSETTLED PATTERN MAY TAKE FORM EARLY NEXT WEEK
BUT LONG RANGE MODELS HAVE NOT QUITE LOCKED ON TO AN AGREED UPON
SOLUTION.
THURSDAY AND FRIDAY MORNING WILL BE THE COOLEST OF THE WEEK AS THE
DRY AIR BEHIND THE FRONT TODAY AND A REINFORCING SHOT OF COOLER
DRIER AIR OCCURS THURSDAY NIGHT. LOCATIONS ACROSS THE HILL COUNTRY
AND SELECT SPOTS ALONG THE I-35 CORRIDOR WILL DROP BELOW TO NEAR
FREEZING. PWATS WILL REMAIN LOW THROUGH THIS TIME FRAME WITH ONLY
0.3" OR LESS. WITH SUCH LITTLE MOISTURE IN PLACE...THE FRONT THAT
MOVES THROUGH LATE THURSDAY WILL BE DRY. 925MB TEMPS FRIDAY WILL
ONLY BE 5-10C EAST TO WEST THAT WILL RESULT IN HIGHS LIKELY ONLY
REACHING THE MID AND UPPER 50S WITH SOME 60S IN THE FAR SOUTH
TOWARDS COTULLA.
SURFACE AND H5 HEIGHT RIDGING WILL OCCUR INTO THE WEEKEND AND
ALLOW FOR THE AIRMASS TO WARM WITH NEAR TO ABOVE NORMAL
TEMPERATURES. RAIN CHANCES REMAIN LOW OVER THE WEEKEND AS THE
SURFACE HIGH SLOWLY SHIFTS TO US EAST COAST AND GENERAL FLOW
OCCURS AHEAD OF DAMPENED SHORTWAVE TROUGH OVER THE FOUR CORNERS.
THIS WEAK SHORTWAVE AND ATTENDANT SURFACE LOW WILL ATTEMPTED TO
BRING A SURFACE FRONT TOWARDS THE REGION LATE SUNDAY INTO MONDAY
BUT IT MAY GET HUNG UP JUST NORTH OR EAST WITH LIMITED FORCING AND
LOW-LVL CONVERGENCE UNDER THE NEARLY PARALLEL SOUTHWEST FLOW. ONE
THING THIS PATTERN WILL HELP WITH IS MODERATING TEMPS AND MOISTURE
WITH PWATS RISING TO 1.3-1.4" BY LATE SUNDAY. HAVE KEPT RAIN
CHANCES LOW MONDAY INTO TUESDAY FOR NOW GIVEN THIS WEAKLY FORCED
SET-UP. MODELS DIVERGE STARTING TUESDAY WITH EC DEPICTING A
SLIGHTLY STRONGER/DEEPER LONGWAVE TROUGH OVER THE CENTRAL CONUS
AND THE PLACEMENT OF AN EJECTING SHORTWAVE IMPULSE. THIS IS A
WETTER SOLUTION THAN THE GFS PRESENTS WHICH KEEPS THE SHORTWAVE
IMPULSE FARTHER SOUTH. THIS FEATURE WILL NEED TO BE WATCHED
CLOSELY AS WE WILL BE ABOVE NORMAL IN TEMPERATURES AND MOISTURE
AND HEAVY RAINS COULD POTENTIALLY RESULT IN THIS ENVIRONMENT IF
THE LIFTING MECHANISMS LINE UP CORRECTLY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 48 62 37 63 37 / 20 - 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 47 63 33 63 33 / 20 - 0 0 0
NEW BRAUNFELS MUNI AIRPORT 48 63 36 65 34 / 20 - 0 0 0
BURNET MUNI AIRPORT 43 60 33 61 33 / 10 0 0 0 0
DEL RIO INTL AIRPORT 41 65 34 65 33 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 45 61 33 62 33 / 10 - 0 0 0
HONDO MUNI AIRPORT 45 66 33 66 32 / 10 0 0 0 0
SAN MARCOS MUNI AIRPORT 48 62 36 63 35 / 20 - 0 0 0
LA GRANGE - FAYETTE REGIONAL 51 64 38 63 37 / 40 10 - 0 0
SAN ANTONIO INTL AIRPORT 50 65 37 66 36 / 10 - 0 0 0
STINSON MUNI AIRPORT 51 66 38 66 35 / 20 - 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...TB3
SYNOPTIC/GRIDS...ALLEN
PUBLIC SERVICE/DATA COLLECTION...30
Area Forecast Discussion
National Weather Service Midland/Odessa TX
245 PM CST TUE DEC 15 2015
.DISCUSSION...
WV imagery shows the upper trough ejecting into the upper Midwest,
trailing a Pac front which sfc analysis places in central Texas at
18Z. This has resulted in a brisk day across West Texas and
Southeast New Mexico, w/temps most locations struggling to get out
of the 50s. Out in the Guadalupes, west winds are right at high
wind warning criteria, and the HWW for this afternoon looks good.
HRRR, NAM, and RAP soundings for KGDP all stay mixed to H7 or so
this afternoon, then rapidly decouple after 23Z. Therefore, we have
no problem letting the HWW expire as planned.
Overnight, under clear skies and relaxing pressure gradients, the
first significant freeze for December is in store for much of the
FA, w/the NW half having a hard freeze. Model performance and
reality the past couple of days suggest guidance temps--especially
the MET--may be too cold. Indeed, NAM H85 temps are colder than
both the GFS and ECMWF in the short term, and so we`ve opted to stay
toward the warmer end of guidance.
That said, temps will still stay below normal thru Friday, as
another trough Thursday send a reinforcing shot of cold air our way.
Upper-lvl ridging follows the trough, allowing temps into next week
to climb into the 60s most locations. A series of dry trough will
pass to the north beginning Sunday, but the net result of these attm
just looking to be windy days and maybe a fire wx concern,
especially Sunday.
&&
.PRELIMINARY POINT TEMPS/POPS...
BIG SPRING TX 29 55 30 50 / 0 0 0 0
CARLSBAD NM 26 53 26 52 / 0 0 0 0
DRYDEN TX 39 62 33 63 / 0 0 0 0
FORT STOCKTON TX 32 54 30 54 / 0 0 0 0
GUADALUPE PASS TX 25 45 24 46 / 0 0 0 0
HOBBS NM 25 52 28 49 / 0 0 0 0
MARFA TX 22 46 19 49 / 0 0 0 0
MIDLAND INTL AIRPORT TX 28 55 29 52 / 0 0 0 0
ODESSA TX 26 52 29 53 / 0 0 0 0
WINK TX 28 56 27 55 / 0 0 0 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...High Wind Warning until 5 PM MST this afternoon FOR THE
FOLLOWING ZONES... Guadalupe Mountains NP/Lincoln NF/LNZ...
Guadalupe Mountains of Eddy County.
TX...High Wind Warning until 5 PM MST this afternoon FOR THE
FOLLOWING ZONES... Guadalupe Mountains.
&&
$$
70/44
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1122 PM CST MON DEC 14 2015
.DISCUSSION...
VFR EXPECTED FOR MOST AREAS TONIGHT. THE LATEST HRRR AND SREF
STILL FORECAST CHANCES FOR FOG OVER KCLL AND POSSIBLY KUTS AND
KCXO. PATCHY GROUND FOG IS LIKELY AT KLBX.
BY THURSDAY AFTERNOON WARM AIR ADVECTION AND MOIST ADVECTION
CLOUDS AND SHOWERS WILL BEGIN AFFECTING THE SITES. THE NAM AND
HIGH RESOLUTION MODELS SHOW THE BEST CHANCES FOR RAIN WILL BEGIN
AFTER 21Z AT KCLL AND KUTS...AND AFTER 00Z AT MOST OF THE
REMAINING INLAND SITES. A MODEL CONSENSUS ALSO FORECASTS MVFR
CONDITIONS TO DEVELOP AFTER 00Z FROM KHOU AND KSGR TO THE COAST.
40
&&
.PREV DISCUSSION... /ISSUED 956 PM CST MON DEC 14 2015/
DISCUSSION...
MADE FEW TWEEKS TO MIN TEMPS AND SKY BASED ON LATEST SATELLITE AND
OBS DATA...OTHERWISE NO CHANGES. FOG FORECAST STILL A LITTLE
TRICKY. LIGHT WINDS AND CLEAR SKY SEEM TO FAVOR RADIATION
FOG...BUT MOIST LAYER VERY SHALLOW. THINK CURRENT GRIDS INDICATING
PATCHY FOG HAVE THE RIGHT IDEA...WITH SOME PATCHES OF SHALLOW FOG
BUT NOTHING WIDESPREAD. 46
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 52 74 53 62 41 / 0 40 50 10 10
HOUSTON (IAH) 51 77 60 67 44 / 0 10 50 20 10
GALVESTON (GLS) 63 74 65 67 51 / 0 10 50 30 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...46
AVIATION/MARINE...40
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1050 PM CST MON DEC 14 2015
.AVIATION.../06Z UPDATE/
VFR CONDITIONS ARE EXPECTED THROUGH EARLY TUESDAY MORNING. AS LOW
LEVEL MOISTURE ACROSS NORTHERN MEXICO AND DEEP SOUTH TEXAS SURGES
NORTHWARD EXPECT TO SEE MVFR CIGS DEVELOP 12Z-14Z. NUMERICAL
GUIDANCE IS INDICATING CIGS FALLING TO IFR. COULD SEE A PERIOD OF
IFR CIGS FROM 14Z-18Z BUT FOR NOW HAVE LEFT OUT OF FORECAST. WITH
PLENTY OF MOISTURE AND WEAK FRONT IN THE AREA ON TUESDAY WE SHOULD
MAINTAIN THE MVFR CIGS UNTIL AFTER 00Z. WINDS WILL BE SOUTHERLY
TONIGHT AND THROUGH ABOUT 20Z TUESDAY WHEN THE WINDS BECOME
NORTHERLY NEAR 10 KNOTS. KDRT WILL LIKELY SEE THE WIND SHIFT
AROUND 14Z. AFTER 12Z PATCHY FOG AND DRIZZLE IS EXPECTED AS
MOISTURE RETURNS THEN LIGHT RAIN OR RAIN SHOWERS ARE POSSIBLE
ALONG AND TO THE EAST OF I-35 AFTER 18Z. ONLY INCLUDED MENTION OF
SHOWERS IN KAUS FORECAST DUE TO BETTER PROBABILITIES.
&&
.PREV DISCUSSION... /ISSUED 840 PM CST MON DEC 14 2015/
UPDATE...
SOME AREAS ARE ALREADY APPROACHING FORECASTED LOW TEMPERATURES.
EVEN THOUGH A SOUTHERLY FLOW HAS RESUMED...DEWPOINTS ARE ONLY
SLOWLY INCREASING AND LOW CLOUD DECK IS STILL SOUTH OF THE LOWER
RIO GRANDE VALLEY OVER FAR NORTHEASTERN MEXICO AND WILL NOT REACH
SOUTH CENTRAL TEXAS UNTIL MORNING. AS A RESULT...WILL LOWER LOW
TEMPERATURES SLIGHTLY IN THOSE AREAS FOR TONIGHT. HAVE ALSO
REESTABLISHED DEWPOINT/RELATIVE HUMIDITY AND WIND TRENDS FOR
TONIGHT. REMAINDER OF THE SOUTH CENTRAL TEXAS FORECAST IS ON
TRACK. 18Z MODELS AND NEW 00Z NAM CONTINUE TO INDICATE SUFFICIENT
MOISTURE CONVERGENCE ALONG THE FRONT TO GENERATE SHOWERS ACROSS
EASTERN PARTS OF SOUTH CENTRAL TEXAS TUESDAY AND TUESDAY NIGHT.
PREV DISCUSSION... /ISSUED 526 PM CST MON DEC 14 2015/
AVIATION.../00Z UPDATE/
VFR CONDITIONS WILL PREVAIL THIS EVENING AND INTO EARLY TUESDAY
MORNING. LOW LEVEL JET OF AT LEAST 30 KNOTS WILL CAUSE A RAPID
INCREASE IN LOW LEVEL MOISTURE AFTER 12Z WHICH WILL LEAD TO MVFR
CIGS DEVELOPING. WEAK FRONT WILL IMPACT THE AREA STARTING OUT WEST
IN THE MORNING TUESDAY AND THEN PROGRESSING EAST THROUGH THE DAY.
WITH ABUNDANT MOISTURE AND WEAK FRONT IN THE AREA WILL CONTINUE
TO SEE MVFR CIGS THROUGH AT LEAST 03Z WEDNESDAY. LIKELY TO SEE A
WINDSHIFT TO THE NW AT KDRT AROUND 13Z. FOR THIS REASON HAVE NOT
INCLUDED MVFR CIGS IN THE FORECAST. WILL MONITOR TRENDS AND MAKE
UPDATES TO LATER FORECAST. THE I-35 SITES WILL SEE THE WINDSHIFT
AROUND 20Z-21Z. AREAS ALONG AND TO THE EAST OF I-35 MAY SEE SOME
SCATTERED LIGHT RAIN/SHOWERS. DID NOT INCLUDE IN THIS FORECAST DUE
TO UNCERTAINTIES IN COVERAGE AND TIMING. WINDS TONIGHT INTO
TUESDAY MORNING WILL BE SOUTHERLY AT 5-10 KNOTS. WITH THE ARRIVAL
OF THE WEAK FRONT WINDS BECOME NORTHERLY AT 7-12 KNOTS.
PREV DISCUSSION... /ISSUED 253 PM CST MON DEC 14 2015/
SHORT TERM (TONIGHT THROUGH TUESDAY)...
FOCUS FOR THE SHORT TERM WILL CENTER AROUND A FRONTAL PASSAGE
TOMORROW INTO EARLY WEDNESDAY THAT WILL HELP GENERATE ISOLATED TO
SCATTERED (20-40% CHANCE) LIGHT RAIN SHOWERS FOR CENTRAL AND
MAINLY EASTERN LOCATIONS.
WATER VAPOR AND RAP ANALYSIS DEPICT AN EXITING SHORTWAVE TROUGH
OVER THE GREAT LAKES REGION AND AN INCOMING LONGWAVE TROUGH OVER
THE WESTERN BASIN. THIS WESTERN BASIN TROUGH IS NOT NEARLY AS
STRONG OR AS DEEP EQUATORWARD AS THE PREVIOUS SYSTEM BUT IT WILL
SEND A COLD FRONT THROUGH THE REGION LATE TUESDAY INTO WEDNESDAY
MORNING. FOR TODAY HOWEVER...DRIER AIR IS IN PLACE WITH A NICE
WARM UP OCCURRING. TEMPERATURES ARE IN THE LOW TO MID 70S AREAWIDE
WITH SOME LOCATIONS IN THE UPPER 70S ACROSS THE RIO GRANDE. EXPECT
ANOTHER 2-3F DEGREES FROM CURRENT READINGS WITH THE AMPLE SUN.
HAVE INCREASED MAX HIGHS FOR THIS AFTERNOON IN CONCERT WITH THESE
TRENDS.
OVERNIGHT AND INTO TUESDAY...MOISTURE IS SLATED TO RETURN BACK
INTO THE REGION FROM THE SOUTH BUT VALUES WILL BE SUBDUED.
CURRENT PWATS NEAR 0.3" WILL ONLY RECOVER TO 0.8" BY TUESDAY
AFTERNOON BEFORE THE FRONT ARRIVES. TUESDAY MORNING WILL BE WARMER
GIVEN A BLANKETING CLOUD COVER THAT WILL ALSO HELP GENERATE SOME
LIGHT PATCHY DRIZZLE. THIS LIGHT DRIZZLE AND LIGHT RAIN WILL
PERSIST INTO THE AFTERNOON ALONG AND AHEAD OF THE FRONT THAT MOVES
THROUGH LATE TUESDAY INTO WEDNESDAY MORNING. OVERALL RAINFALL
AMOUNTS ARE EXPECTED TO BE LIGHT WITH AT OR LESS THAN ONE QUARTER
OF AN INCH EXPECTED. CLOUDS LOOK TO HANG ON MOST OF THE DAY
TUESDAY SO LOWER HIGH TEMPERATURES ARE EXPECTED GIVEN NAM/GFS BUFR
SOUNDING OUTPUT.
LONG TERM (WEDNESDAY THROUGH MONDAY)...
A GENERALLY QUIET AND NEAR NORMAL TEMPERATURE REGIME WILL BE IN
STORE FOR THE REGION THROUGH THE END OF THE WEEK. CLOUDS WILL
RETURN OVER THE WEEKEND WITH A LOW-END RAIN CHANCE BY MONDAY WITH
THE PASSAGE OF ANOTHER DISTURBANCE IN THE CENTRAL PLAINS.
MID TO LATE WEEK WILL BE PLEASANT WITH SUNNY SKIES AND NEAR NORMAL
TEMPERATURES WITH LOWS IN THE LOWER TO MID 40S AND HIGHS IN THE
MID 60S. FRIDAY WILL BE SLIGHTLY COOLER AS RESIDUAL COOL AIR
ADVECTION CONTINUES JUST BEFORE WINDS TURN BACK OUT OF THE SOUTH.
PWATS WILL REMAIN QUITE LOW /0.15-0.3"/ THROUGH FRIDAY BEFORE
INCREASING TO 0.6-0.7" ON SATURDAY. SOUTH WINDS WILL AID THIS PWAT
INCREASE AS A H5 SHORTWAVE TROUGH AND ASSOCIATED SURFACE TROUGH
HELP GENERATE SOUTH FLOW OVER THE REGION. THE EC IS SLIGHTLY
DRIER AS IT DEPICTS ENERGY FARTHER NORTH VS. THE GFS. HAVE HELD
OFF ON INTRODUCING RAIN CHANCES FOR SATURDAY AND SUNDAY AT THIS
TIME BUT DID PLACE A LOW-END 20% FOR MONDAY WHERE BETTER MODEL
AGREEMENT OCCURS. AT THIS PARTICULAR STAGE...PWATS MAY REACH
UPWARDS OF 1.3-1.5" IN THE FAR EAST BEFORE THIS FRONT MOVES
THROUGH MONDAY AND THIS WOULD LIKELY SUPPORT SOME SHOWER ACTIVITY
DESPITE THE SIDESWIPE OF THE TROUGH ENERGY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 49 72 49 64 38 / 0 30 20 0 -
AUSTIN BERGSTROM INTL AIRPORT 43 73 48 64 35 / 0 30 20 - -
NEW BRAUNFELS MUNI AIRPORT 47 73 50 64 37 / 0 30 20 - -
BURNET MUNI AIRPORT 47 68 43 60 35 / 0 20 10 0 -
DEL RIO INTL AIRPORT 45 66 41 65 36 / 0 - 0 0 0
GEORGETOWN MUNI AIRPORT 46 71 45 61 35 / 0 30 10 0 -
HONDO MUNI AIRPORT 47 71 48 66 35 / 0 20 10 0 0
SAN MARCOS MUNI AIRPORT 48 72 49 64 36 / 0 30 20 - -
LA GRANGE - FAYETTE REGIONAL 50 77 54 64 39 / 0 30 40 - -
SAN ANTONIO INTL AIRPORT 49 73 51 65 38 / 0 20 10 0 -
STINSON MUNI AIRPORT 49 75 53 66 39 / 0 20 10 0 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...10
SYNOPTIC/GRIDS...04
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1139 AM CST TUE DEC 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CST TUE DEC 15 2015
LOOKING LIKE A WIDESPREAD LIGHT PRECIPITATION SYSTEM COMING IN
OVERNIGHT WITH SOME FREEZING RAIN CHANCES IN THE FAR NORTH...NORTH
OF HIGHWAY 29. OTHERWISE...A QUIET FORECAST THE NEXT 7 DAYS.
GOES FOG PRODUCT IMAGERY SHOWING A LARGE AND EXPANSIVE LOW CLOUD
AREA ACROSS THE REGION WITH THE SOUTHERN EXTENT DEFINED BY A
STATIONARY FRONTAL BOUNDARY PARALLELING AND SOUTH OF I-70. RAOBS
FROM 15.00Z SHOW A 1.5-3KM DEEP SURFACE-BASED SATURATED LAYER IN
PLACE /INCREASING NORTHWARD/. WATER VAPOR IMAGERY SHOWING THE
NEXT VIGOROUS SHORTWAVE TROUGH OVER SE COLORADO EJECTING N-NE
TOWARD THE REGION. THE RAP ANALYZES A TROPOPAUSE FOLD DOWN TO
700MB WITH THAT FEATURE...PRETTY IMPRESSIVE. SURFACE PRESSURES
HAVE BEEN FALLING IN THAT SAME AREA AS LOW PRESSURE WILL EJECT
THROUGH MN...WITH 00Z MODELS ALL LOOKING VERY SIMILAR IN THEIR
EVOLUTION THROUGH 24/30 HOURS.
WITHIN THE SATURATED SURFACE-BASED LAYER...WARM ADVECTION OR
ISENTROPIC LIFT...ALONG WITH A BIT OF MOISTURE TRANSPORT
CONVERGENCE WILL MOVE IN TONIGHT AFTER 9 PM. THE FRONTAL BOUNDARY
NEAR I-70 WILL BE WORKED NORTH WITH A MOIST SURGE SOUTHEAST OF THE
CYCLONE TRACK. 300-500MB QG FORCING IS QUITE STRONG AS EXPECTED
WITH THIS SHORTWAVE...AND MOST OF THE FORECAST AREA WILL FEEL
THIS...ALBEIT THOSE FURTHER NW MORE AS THE MID-LEVEL LOW TRACKS
THROUGH MN. THIS IS WELL AGREED UPON WITH THE DETERMINISTIC
MODELS.
FORECAST CHANGES...
WITH FORCING MOVING IN...ESPECIALLY IN THE LOW-LEVELS...IN
CONCERT WITH AN ALREADY PRESENT MOIST LAYER TO 1.5-3KM...AND EVEN
MORE MOISTURE WORKING NORTH TO DEEPEN THE LAYER FURTHER...WIDESPREAD
LIGHT PRECIPITATION SHOULD BE PRODUCED. HAVE ADJUSTED CHANCES
OVERNIGHT ACCORDINGLY. PRECIPITATION TYPE LOOKS TO BE
LIQUID...WITH VERY LOW PROBABILITIES OF CLOUD ICE IN THE -10C OR
COLDER REGIME ALOFT SHOWN IN THE MODEL SOUNDINGS. BELIEVE MOST OF
THE AREA WILL BE ABOVE FREEZING...EXCEPT FOR NORTH CENTRAL WI.
AREAS NORTH OF ABOUT HIGHWAY 29 COULD SEE A PERIOD OF LIGHT FZRA
AT THE ONSET...BEFORE WARM ADVECTION KICKS TEMPERATURES ABOVE
FREEZING /AFTER 09Z/. HAVE CONTINUED A MINOR GLAZE OF ICE IN THE
FORECAST GRIDS.
WHAT COULD GO WRONG...
TEMPERATURES COULD WARM RAPIDLY TONIGHT AND THE GLAZE ICE THREAT
NORTH OF HIGHWAY 29 COULD DIMINISH. ALSO WITH SUCH A STRONG
SHORTWAVE TROUGH ALOFT MOVING THROUGH MN...AND QG SIGNAL IN THE
MID-UPPER TROPOSPHERE...HAVING A BIT OF TROUBLE WITH MODELS NOT
SATURATING ALOFT FOR ICE. HIGHEST PROBABILITIES WOULD BE TO THE
NORTHWEST WITH FORCING MAX IN MN...AND THE OUTCOME WOULD BE A
PERIOD OF LIGHT SNOW OR SLEET /VERSUS -RA-FZRA/.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 332 AM CST TUE DEC 15 2015
LARGE SCALE SHOWING AN ACTIVE LONG WAVE 5 PATTERN ACROSS THE
NORTHERN HEMISPHERE AND THE PACIFIC JUST KEEPS ENERGY COMING INTO
NORTH AMERICA. AFTER THE SHORTWAVE TROUGH EJECTS THROUGH THE GREAT
LAKES THROUGH WEDNESDAY THE LONG WAVE TROUGH OVER THE WRN CONUS
MOVES OVERHEAD FOR THURSDAY-FRIDAY. COLD ADVECTION AND MORE NORMAL
OR BELOW NORMAL TEMPERATURES? THIS WILL REALLY HAMPER THE PALM
TREES GROWING MY FRONT YARD. SOME SNOW SHOWER ACTIVITY MAY BE
FOUND OVER NORTHERN WISCONSIN...OTHERWISE A DRIER AND COLDER
PERIOD.
SATURDAY THROUGH MONDAY...
AS THE NEXT LONG WAVE THEN DIGS INTO THE WRN CONUS /AGAIN/...THE
NORTHERN PLAINS THROUGH GREAT LAKES WILL SEE LONG WAVE RIDGING
AND FAIR CONDITIONS. PROGRESSION IS YOUR FRIEND...AND TEMPERATURES
WILL REBOUND TO ABOVE NORMAL BY SUNDAY. MOST IMPORTANTLY...NO
IMPACTS ACROSS THE REGION FOR WEEKEND TRAVEL. MORE TROUGH ENERGY
LOOKS TO MOVE IN FOR THE EARLY PART OF THE HOLIDAY WEEK...AND
PRECIPITATION LOOKS TO BE RAIN INSTEAD OF SNOW /AGAIN/.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1139 AM CST TUE DEC 15 2015
WIDESPREAD STRATUS WILL CONTINUE TO IMPACT THE TAF SITES OVER THE
NEXT 24 HOURS...WITH INCREASINGLY SOUTHERLY FLOW OUT AHEAD OF LOW
PRESSURE EXPECTED TO PASS THROUGH SOUTHERN MINNESOTA BY WEDNESDAY
MORNING. INCREASING LIFT AND SATURATION (THOUGH STILL SHALLOW)
SHOULD BRING SLOWLY LOWERING CEILINGS ALONG WITH SOME DRIZZLE
DEVELOPMENT...BEFORE A PERIOD OF LIGHT RAIN ARRIVES FOR MANY AREAS
BETWEEN 06Z AND 12Z JUST AHEAD OF AN INCOMING COLD FRONT...WITH
IFR CONDITIONS EXPECTED FOR BOTH LSE AND RST. IMPROVEMENT WILL
COME DURING THE LATER MORNING HOURS AS THAT FRONT PASSES...WITH
CEILINGS BACK TO MVFR LEVELS BUT WINDS BECOMING RATHER GUSTY FROM
THE SOUTH UP TO 30 KNOTS.
&&
.HYDROLOGY...
ISSUED AT 332 AM CST TUE DEC 15 2015
THE RIVERS ACROSS THE AREA ARE STILL RISING AT MANY LOCATIONS...WITH
A FEW MORE MODERATE FLOOD LEVELS EXPECTED BASED ON THE MONDAY
EVENING FORECAST. WITH ADDITIONAL RAINFALL IN THE NEXT 5 DAYS
MINIMAL...WOULD EXPECT CURRENT FORECASTS AND RIVER SITUATION TO BE
STABILIZED AND ROUTING FAIRLY PREDICTABLE. WITH THAT SAID...IF
THIS PATTERN CONTINUES LONGER TERM...IT COULD BE ONE WINTER FOR
THE RECORD BOOKS WITH PRECIPITATION AMOUNTS AND RENEWED FLOODING
THREATS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...LAWRENCE
HYDROLOGY...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
536 AM CST TUE DEC 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CST TUE DEC 15 2015
LOOKING LIKE A WIDESPREAD LIGHT PRECIPITATION SYSTEM COMING IN
OVERNIGHT WITH SOME FREEZING RAIN CHANCES IN THE FAR NORTH...NORTH
OF HIGHWAY 29. OTHERWISE...A QUIET FORECAST THE NEXT 7 DAYS.
GOES FOG PRODUCT IMAGERY SHOWING A LARGE AND EXPANSIVE LOW CLOUD
AREA ACROSS THE REGION WITH THE SOUTHERN EXTENT DEFINED BY A
STATIONARY FRONTAL BOUNDARY PARALLELING AND SOUTH OF I-70. RAOBS
FROM 15.00Z SHOW A 1.5-3KM DEEP SURFACE-BASED SATURATED LAYER IN
PLACE /INCREASING NORTHWARD/. WATER VAPOR IMAGERY SHOWING THE
NEXT VIGOROUS SHORTWAVE TROUGH OVER SE COLORADO EJECTING N-NE
TOWARD THE REGION. THE RAP ANALYZES A TROPOPAUSE FOLD DOWN TO
700MB WITH THAT FEATURE...PRETTY IMPRESSIVE. SURFACE PRESSURES
HAVE BEEN FALLING IN THAT SAME AREA AS LOW PRESSURE WILL EJECT
THROUGH MN...WITH 00Z MODELS ALL LOOKING VERY SIMILAR IN THEIR
EVOLUTION THROUGH 24/30 HOURS.
WITHIN THE SATURATED SURFACE-BASED LAYER...WARM ADVECTION OR
ISENTROPIC LIFT...ALONG WITH A BIT OF MOISTURE TRANSPORT
CONVERGENCE WILL MOVE IN TONIGHT AFTER 9 PM. THE FRONTAL BOUNDARY
NEAR I-70 WILL BE WORKED NORTH WITH A MOIST SURGE SOUTHEAST OF THE
CYCLONE TRACK. 300-500MB QG FORCING IS QUITE STRONG AS EXPECTED
WITH THIS SHORTWAVE...AND MOST OF THE FORECAST AREA WILL FEEL
THIS...ALBEIT THOSE FURTHER NW MORE AS THE MID-LEVEL LOW TRACKS
THROUGH MN. THIS IS WELL AGREED UPON WITH THE DETERMINISTIC
MODELS.
FORECAST CHANGES...
WITH FORCING MOVING IN...ESPECIALLY IN THE LOW-LEVELS...IN
CONCERT WITH AN ALREADY PRESENT MOIST LAYER TO 1.5-3KM...AND EVEN
MORE MOISTURE WORKING NORTH TO DEEPEN THE LAYER FURTHER...WIDESPREAD
LIGHT PRECIPITATION SHOULD BE PRODUCED. HAVE ADJUSTED CHANCES
OVERNIGHT ACCORDINGLY. PRECIPITATION TYPE LOOKS TO BE
LIQUID...WITH VERY LOW PROBABILITIES OF CLOUD ICE IN THE -10C OR
COLDER REGIME ALOFT SHOWN IN THE MODEL SOUNDINGS. BELIEVE MOST OF
THE AREA WILL BE ABOVE FREEZING...EXCEPT FOR NORTH CENTRAL WI.
AREAS NORTH OF ABOUT HIGHWAY 29 COULD SEE A PERIOD OF LIGHT FZRA
AT THE ONSET...BEFORE WARM ADVECTION KICKS TEMPERATURES ABOVE
FREEZING /AFTER 09Z/. HAVE CONTINUED A MINOR GLAZE OF ICE IN THE
FORECAST GRIDS.
WHAT COULD GO WRONG...
TEMPERATURES COULD WARM RAPIDLY TONIGHT AND THE GLAZE ICE THREAT
NORTH OF HIGHWAY 29 COULD DIMINISH. ALSO WITH SUCH A STRONG
SHORTWAVE TROUGH ALOFT MOVING THROUGH MN...AND QG SIGNAL IN THE
MID-UPPER TROPOSPHERE...HAVING A BIT OF TROUBLE WITH MODELS NOT
SATURATING ALOFT FOR ICE. HIGHEST PROBABILITIES WOULD BE TO THE
NORTHWEST WITH FORCING MAX IN MN...AND THE OUTCOME WOULD BE A
PERIOD OF LIGHT SNOW OR SLEET /VERSUS -RA-FZRA/.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 332 AM CST TUE DEC 15 2015
LARGE SCALE SHOWING AN ACTIVE LONG WAVE 5 PATTERN ACROSS THE
NORTHERN HEMISPHERE AND THE PACIFIC JUST KEEPS ENERGY COMING INTO
NORTH AMERICA. AFTER THE SHORTWAVE TROUGH EJECTS THROUGH THE GREAT
LAKES THROUGH WEDNESDAY THE LONG WAVE TROUGH OVER THE WRN CONUS
MOVES OVERHEAD FOR THURSDAY-FRIDAY. COLD ADVECTION AND MORE NORMAL
OR BELOW NORMAL TEMPERATURES? THIS WILL REALLY HAMPER THE PALM
TREES GROWING MY FRONT YARD. SOME SNOW SHOWER ACTIVITY MAY BE
FOUND OVER NORTHERN WISCONSIN...OTHERWISE A DRIER AND COLDER
PERIOD.
SATURDAY THROUGH MONDAY...
AS THE NEXT LONG WAVE THEN DIGS INTO THE WRN CONUS /AGAIN/...THE
NORTHERN PLAINS THROUGH GREAT LAKES WILL SEE LONG WAVE RIDGING
AND FAIR CONDITIONS. PROGRESSION IS YOUR FRIEND...AND TEMPERATURES
WILL REBOUND TO ABOVE NORMAL BY SUNDAY. MOST IMPORTANTLY...NO
IMPACTS ACROSS THE REGION FOR WEEKEND TRAVEL. MORE TROUGH ENERGY
LOOKS TO MOVE IN FOR THE EARLY PART OF THE HOLIDAY WEEK...AND
PRECIPITATION LOOKS TO BE RAIN INSTEAD OF SNOW /AGAIN/. A BLEND OF
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 536 AM CST TUE DEC 15 2015
EXPANSIVE MVFR/IFR CLOUD DECK ACROSS THE UPPER MIDWEST THIS
MORNING NOT LIKELY TO GO FAR THROUGH THE PERIOD...ALTHOUGH CURIOUS
CLEARING HOLE ACROSS SOUTH-CENTRAL WI AS OF 15.1130Z SHOULD FILL
BACK IN RATHER QUICKLY. WILL COVER KLSE WITH A VFR TEMPO GROUP FOR
A COUPLE HOURS BEFORE RETURNING TO PREDOMINANT MVFR CEILINGS AFTER
15.14Z.
EXPECT A LOWERING OF CEILINGS THIS EVENING AND ESPECIALLY OVERNIGHT
AS THE NEXT STORM SYSTEM MOVES ACROSS THE REGION. LIGHT DRIZZLE
LATE THIS EVENING SHOULD CHANGE OVER TO PURE RAIN OVERNIGHT WITH
MAINLY IFR CEILINGS/MVFR VISIBILITY RESTRICTIONS...CONTINUING
THROUGH 16.12Z. LIGHT NORTHERLY WINDS THIS MORNING WILL GRADUALLY
TURN TO THE EAST...GUSTING INTO THE LOW 20 KT RANGE BEGINNING LATE
AFTERNOON AND INTO THE OVERNIGHT HOURS AS PRESSURE GRADIENT
TIGHTENS AHEAD OF THE APPROACHING SURFACE LOW.
&&
.HYDROLOGY...
ISSUED AT 332 AM CST TUE DEC 15 2015
THE RIVERS ACROSS THE AREA ARE STILL RISING AT MANY LOCATIONS...WITH
A FEW MORE MODERATE FLOOD LEVELS EXPECTED BASED ON THE MONDAY
EVENING FORECAST. WITH ADDITIONAL RAINFALL IN THE NEXT 5 DAYS
MINIMAL...WOULD EXPECT CURRENT FORECASTS AND RIVER SITUATION TO BE
STABILIZED AND ROUTING FAIRLY PREDICTABLE. WITH THAT SAID...IF
THIS PATTERN CONTINUES LONGER TERM...IT COULD BE ONE WINTER FOR
THE RECORD BOOKS WITH PRECIPITATION AMOUNTS AND RENEWED FLOODING
THREATS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...ROGERS
HYDROLOGY...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
332 AM CST TUE DEC 15 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CST TUE DEC 15 2015
LOOKING LIKE A WIDESPREAD LIGHT PRECIPITATION SYSTEM COMING IN
OVERNIGHT WITH SOME FREEZING RAIN CHANCES IN THE FAR NORTH...NORTH
OF HIGHWAY 29. OTHERWISE...A QUIET FORECAST THE NEXT 7 DAYS.
GOES FOG PRODUCT IMAGERY SHOWING A LARGE AND EXPANSIVE LOW CLOUD
AREA ACROSS THE REGION WITH THE SOUTHERN EXTENT DEFINED BY A
STATIONARY FRONTAL BOUNDARY PARALLELING AND SOUTH OF I-70. RAOBS
FROM 15.00Z SHOW A 1.5-3KM DEEP SURFACE-BASED SATURATED LAYER IN
PLACE /INCREASING NORTHWARD/. WATER VAPOR IMAGERY SHOWING THE
NEXT VIGOROUS SHORTWAVE TROUGH OVER SE COLORADO EJECTING N-NE
TOWARD THE REGION. THE RAP ANALYZES A TROPOPAUSE FOLD DOWN TO
700MB WITH THAT FEATURE...PRETTY IMPRESSIVE. SURFACE PRESSURES
HAVE BEEN FALLING IN THAT SAME AREA AS LOW PRESSURE WILL EJECT
THROUGH MN...WITH 00Z MODELS ALL LOOKING VERY SIMILAR IN THEIR
EVOLUTION THROUGH 24/30 HOURS.
WITHIN THE SATURATED SURFACE-BASED LAYER...WARM ADVECTION OR
ISENTROPIC LIFT...ALONG WITH A BIT OF MOISTURE TRANSPORT
CONVERGENCE WILL MOVE IN TONIGHT AFTER 9 PM. THE FRONTAL BOUNDARY
NEAR I-70 WILL BE WORKED NORTH WITH A MOIST SURGE SOUTHEAST OF THE
CYCLONE TRACK. 300-500MB QG FORCING IS QUITE STRONG AS EXPECTED
WITH THIS SHORTWAVE...AND MOST OF THE FORECAST AREA WILL FEEL
THIS...ALBEIT THOSE FURTHER NW MORE AS THE MID-LEVEL LOW TRACKS
THROUGH MN. THIS IS WELL AGREED UPON WITH THE DETERMINISTIC
MODELS.
FORECAST CHANGES...
WITH FORCING MOVING IN...ESPECIALLY IN THE LOW-LEVELS...IN
CONCERT WITH AN ALREADY PRESENT MOIST LAYER TO 1.5-3KM...AND EVEN
MORE MOISTURE WORKING NORTH TO DEEPEN THE LAYER FURTHER...WIDESPREAD
LIGHT PRECIPITATION SHOULD BE PRODUCED. HAVE ADJUSTED CHANCES
OVERNIGHT ACCORDINGLY. PRECIPITATION TYPE LOOKS TO BE
LIQUID...WITH VERY LOW PROBABILITIES OF CLOUD ICE IN THE -10C OR
COLDER REGIME ALOFT SHOWN IN THE MODEL SOUNDINGS. BELIEVE MOST OF
THE AREA WILL BE ABOVE FREEZING...EXCEPT FOR NORTHCENTRAL WI.
AREAS NORTH OF ABOUT HIGHWAY 29 COULD SEE A PERIOD OF LIGHT FZRA
AT THE ONSET...BEFORE WARM ADVECTION KICKS TEMPERATURES ABOVE
FREEZING /AFTER 09Z/. HAVE CONTINUED A MINOR GLAZE OF ICE IN THE
FORECAST GRIDS.
WHAT COULD GO WRONG...
TEMPERATURES COULD WARM RAPIDLY TONIGHT AND THE GLAZE ICE THREAT
NORTH OF HIGHWAY 29 COULD DIMINISH. ALSO WITH SUCH A STRONG
SHORTWAVE TROUGH ALOFT MOVING THROUGH MN...AND QG SIGNAL IN THE
MID-UPPER TROPOSPHERE...HAVING A BIT OF TROUBLE WITH MODELS NOT
SATURATING ALOFT FOR ICE. HIGHEST PROBABILITIES WOULD BE TO THE
NORTHWEST WITH FORCING MAX IN MN...AND THE OUTCOME WOULD BE A
PERIOD OF LIGHT SNOW OR SLEET /VERSUS -RA-FZRA/.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 332 AM CST TUE DEC 15 2015
LARGE SCALE SHOWING AN ACTIVE LONG WAVE 5 PATTERN ACROSS THE
NORTHERN HEMISPHERE AND THE PACIFIC JUST KEEPS ENERGY COMING INTO
NORTH AMERICA. AFTER THE SHORTWAVE TROUGH EJECTS THROUGH THE GREAT
LAKES THROUGH WEDNESDAY THE LONG WAVE TROUGH OVER THE WRN CONUS
MOVES OVERHEAD FOR THURSDAY-FRIDAY. COLD ADVECTION AND MORE NORMAL
OR BELOW NORMAL TEMPERATURES? THIS WILL REALLY HAMPER THE PALM
TREES GROWING MY FRONT YARD. SOME SNOW SHOWER ACTIVITY MAY BE
FOUND OVER NORTHERN WISCONSIN...OTHERWISE A DRIER AND COLDER
PERIOD.
SATURDAY THROUGH MONDAY...
AS THE NEXT LONG WAVE THEN DIGS INTO THE WRN CONUS /AGAIN/...THE
NORTHERN PLAINS THROUGH GREAT LAKES WILL SEE LONG WAVE RIDGING
AND FAIR CONDITIONS. PROGRESSION IS YOUR FRIEND...AND TEMPERATURES
WILL REBOUND TO ABOVE NORMAL BY SUNDAY. MOST IMPORTANTLY...NO
IMPACTS ACROSS THE REGION FOR WEEKEND TRAVEL. MORE TROUGH ENERGY
LOOKS TO MOVE IN FOR THE EARLY PART OF THE HOLIDAY WEEK...AND
PRECIPITATION LOOKS TO BE RAIN INSTEAD OF SNOW /AGAIN/. A BLEND OF
MODEL GUIDANCE WAS USED FOR THIS PERIOD OF FORECASTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1110 PM CST MON DEC 14 2015
LOW LEVEL MOISTURE IS GOING TO REMAIN TRAPPED BELOW A TEMP
INVERSION...THUS KEEPING LOW CIGS HANGING AROUND THROUGH AT LEAST
WED. EXPECT MOSTLY MVFR INTO TUE NIGHT...WITH A DIP DOWN AS ANOTHER
LOW PRESSURE SYSTEM MOVES IN FROM THE SOUTHWEST. WHILE THE BULK OF
THE ACCUMULATING PCPN WITH THIS LOW WILL HOLD NORTH...ENOUGH LIFT
THAT -DZ/RA IS LOOKING LIKELY TUE NIGHT-WED FOR KRST/KLSE.
&&
.HYDROLOGY...
ISSUED AT 332 AM CST TUE DEC 15 2015
THE RIVERS ACROSS THE AREA ARE STILL RISING AT MANY LOCATIONS...WITH
A FEW MORE MODERATE FLOOD LEVELS EXPECTED BASED ON THE MONDAY
EVENING FORECAST. WITH ADDITIONAL RAINFALL IN THE NEXT 5 DAYS
MINIMAL...WOULD EXPECT CURRENT FORECASTS AND RIVER SITUATION TO BE
STABILIZED AND ROUTING FAIRLY PREDICTABLE. WITH THAT SAID...IF
THIS PATTERN CONTINUES LONGER TERM...IT COULD BE ONE WINTER FOR
THE RECORD BOOKS WITH PRECIPITATION AMOUNTS AND RENEWED FLOODING
THREATS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1146 AM MST TUE DEC 15 2015
.UPDATE...
ISSUED AT 940 AM MST TUE DEC 15 2015
CONSENSUS DECISION AMONGST OUR TEAM THIS MORNING WAS TO UPGRADE
TO A WINTER STORM WARNING FOR OUR FOUR ZONES FROM THE SOUTHERN
LARAMIE RANGE AND SUMMIT...TO THE SOUTHERN LARAMIE RANGE
FOOTHILLS...CENTRAL AND EASTERN LARAMIE COUNTY INCLUDING CHEYENNE.
LATEST MEASUREMENTS INCLUDE 5 1/2 INCHES OF SNOW OFFICIALLY
IN CHEYENNE...AND WITH THE UPPER LOW SOMEWHAT SLOWER THAN MODELS
EARLIER DEPICTED...NICE SNOWFALL BANDING AS SEEN ON WSR-88D
REFLECTIVITY...AND PROJECTED HRRR HOURLY SNOWFALL RATES...WE FEEL
IT IS PRUDENT TO UPGRADE TO A WINTER STORM WARNING FOR
AFOREMENTIONED ZONES. PRESSURE GRADIENTS WILL SLOWLY INCREASE
THIS AFTERNOON AND NORTH WINDS EXPECTED TO INCREASE SLOWLY AND
COMBINED WITH WINDS AND TEMPERATURES FALLING INTO THE TEENS...
ALONG WITH FALLING AND BLOWING SNOW...VISIBILITIES WILL BE
OCCASIONALLY NEAR ZERO AT TIMES...ESPECIALLY WITH THE POWDERY
NATURE OF THE SNOW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 436 AM MST TUE DEC 15 2015
STORM SYSTEM OVER COLORADO STILL ON TRACK TO PICK UP SPEED AND
SHIFT QUICKLY EAST INTO THE PLAINS TODAY. THE MAIN QUESTION AT
THIS TIME IS HOW MUCH WARP AROUND PRECIPITATION WILL OCCUR OVER
THE FORECAST AREA. ONE AREA THAT HAS NOT PICKED UP AS MUCH SNOW
AS EXPECTED IS INTO EAST CENTRAL WYOMING SUCH AS AROUND DOUGLAS.
AS OF 4 AM ONLY A DUSTING TO A HALF AN INCH OF SNOW WAS REPORTED
ACROSS CONVERSE COUNTY. THIS COMPARES TO 2 OR 5 INCHES THAT
SHOULD HAVE BEEN ON THE GROUND ACCORDING TO YESTERDAYS NUMERICAL
MODELS.
DOWNGRADED THE WINTER STORM WARNING TO AN ADVISORY FOR NIOBRARA
AND CONVERSE COUNTIES. ALSO THE NORTHERN LARAMIE RANGE IN THE
CHEYENNE FORECAST AREA IS ONLY SHOWING 3 TO 5 INCHES BASED ON
SNOTELS WHILE 6 TO 9 INCHES SHOULD HAVE ALREADY FALLEN. SHOULD
STILL SEE SOME LIGHT WRAP AROUND PRECIPITATION OVER THIS AREA
THROUGH THIS AFTERNOON BUT AGAIN THE MODELS ARE LIKELY OVERDOING
THE PRECIPITATION AMOUNTS...ESPECIALLY CONSIDERING HOW QUICKLY
THIS SYSTEM WILL SHIFT EAST AND LACK OF A DEEP MOISTURE SOURCE.
THE MAIN UPPER LEVEL SUPPORT CURRENTLY OVER FAR SOUTHEAST WYOMING
AND NE PANHANDLE WILL DECREASE THE REST OF TODAY...AND BY LATER
THIS MORNING DOWNSLOPE NORTHWEST WINDS WILL DEVELOP...MAKING IT
MORE DIFFICULT FOR ACCUMULATING SNOWS TO OCCUR IN SOUTHEAST
WYOMING. OF COURSE NORTHWEST WINDS FAVOR PLACES LIKE THE PINE
RIDGE FOR UPSLOPE SNOW ENHANCEMENT.
THE HIGHER SNOW AMOUNTS SHOULD GENERALLY BE FOUND OVER THE
NEBRASKA PANHANDLE. MODELS STILL PAINTING A LOT OF PRECIPITATION...
ESPECIALLY OVER THE SOUTHERN NEBRASKA PANHANDLE WHERE THE
STRONGEST LOWER TO MID LEVEL THETAE ADVECTION WILL OCCUR. GIVEN
THE FACT THAT SIDNEY SHOULD ALREADY HAVE .15 INCHES OF LIQUID AND
IS ONLY NOW STARTING TO SNOW...IT DOES NOT BODE WELL FOR THE
MODELS HAVING A GOOD HANDLE ON THE AMOUNT OF MOISTURE AVAILABLE.
THEREFORE THE CURRENT SNOW FORECAST VERY WELL COULD BE A FEW
INCHES TOO GENEROUS. REGARDLESS...THERE WILL BE ACCUMULATIONS OF
SNOW MAKING ROADS SNOW COVERED AND SLIPPERY. NOT EXPECTING MUCH IN
THE WAY OF BLOWING SNOW TODAY. OF COURSE THE SNOW WILL BE BLOWING
AS IT IS FALLING BUT AS FOR SNOW ON THE GROUND BE RELOFTED INTO
THE AIR THERE WILL GENERALLY NOT BE ENOUGH SNOW ON THE GROUND FOR
THAT TO OCCUR. GRANTED SOME BLOWING SNOW WILL OCCUR BUT THE BIGGER
FACTOR WILL BE DRIFTING. WINDS WILL BE STRONG ENOUGH TODAY TO
PRODUCE DRIFTS. SHOULD SEE ONE TO THREE FOOT HIGH DRIFTS DEPENDING
OF COURSE ON HOW MUCH SNOW FALLS AT ANY GIVEN LOCATION.
SNOW WILL BEGIN TO TAPER OFF FROM WEST TO EAST TODAY. MOST SNOW
ACCUMULATION WILL END BY EARLY THIS EVENING WITH SOME LIGHT SNOW
LINGERING INTO THE NORTHERN NEBRASKA PANHANDLE. WINDS WILL REMAINS
GUSTY THROUGH TONIGHT ACROSS THE PLAINS WITH RELATIVELY LIGHT
WINDS INTO SOUTH CENTRAL WY. WINDS WILL INCREASE ACROSS THE
ARLINGTON AREA TOMORROW NIGHT INTO WEDNESDAY. THAT IS A CONCERN
GIVEN THE NEW SNOW FALL IN THAT AREA. BLOWING SNOW MAY BECOME AN
ISSUE FOR SEVERAL HOURS WEDNESDAY MORNING AROUND ARLINGTON.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 340 AM MST TUE DEC 15 2015
THE MODELS HAVE BEEN PRETTY CONSISTENT AT SHOWING A SHORTWAVE DIVING
SOUTHEASTWARD FROM WYOMING INTO COLORADO ON THURS. THERE IS SOME
DECENT ASCENT IN AREAS ALONG INTERSTATE 80 ON THURS MORNING BEFORE
SUBSIDENCE ENSUES DURING THE AFTN. 700MB TEMPS ARE QUITE COLD (-
18C) BEHIND THE UPPER WAVE SO HIGHS WILL STRUGGLE TO GET OUT OF THE
LOW 20S. HEIGHTS RISE BY FRI AND A SFC TROUGH DEVELOPS ALONG THE
LARAMIE RANGE. THE 850MB CAG-CPR GRADIENT RISES TO AROUND 60 MTRS
AND WITH WARM AIR ADVECTION ALOFT...COULD SEE HIGH WINDS DEVELOP IN
THE ARLINGTON/VEDAUWOO AREAS. THE REAL WARMUP COMES ON SAT AS 700MB
TEMPS RISE TO 0C AND HIGHS WILL BE BACK INTO THE UPPER 40S TO THE
EAST OF THE LARAMIE RANGE. WHILE THERE COULD BE SOME STRONG WIND
GUSTS IN THE WIND PRONE AREAS...THE LLVL GRADIENT DOES NOT LOOK
STRONG ENOUGH TO SUPPORT A WIDESPREAD HIGH WIND EVENT OVER THESE
AREAS. TEMPS ON SUN/MON WILL BE SLIGHTLY COOLER AND THERE WILL BE
A CHANCE OF OROGRAPHIC SNOW IN THE SIERRA MADRE AND SNOWY RANGES
AS PACIFIC MOISTURE STREAMS INTO THE REGION IN INCREASING ZONAL
FLOW ALOFT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1146 AM MST TUE DEC 15 2015
WIDESPREAD IFR/LIFR CONDITIONS DUE TO SNOW AND BLOWING SNOW WILL
OCCUR THROUGH THE EARLY EVENING FOR MOST TERMINALS. PERIODS OF
MODERATE SNOW WILL BE POSSIBLE ESPECIALLY TO THE EAST OF THE
LARAMIE RANGE...REDUCING VIS DOWN TO LESS THAN ONE HALF MILE AT
TIMES. BREEZY NORTH WINDS WILL OCCUR WITH GUSTS TO 25-30 KTS. THE
SNOW WILL GRADUALLY TAPER OFF BY THE EVENING.
&&
.FIRE WEATHER...
ISSUED AT 430 AM MST TUE DEC 15 2015
SNOW WILL SLOWLY TAPER OFF FROM WEST TO EAST ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA PANHANDLE TODAY INTO TONIGHT.
BLOWING AND DRIFTING SNOW.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR
WYZ101>103-106>108-115.
WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR WYZ116>119.
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR WYZ104-
105-109-111-113.
WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ110-
112-114.
NE...WINTER STORM WARNING UNTIL 3 AM MST WEDNESDAY FOR NEZ002-003-
019>021-054-055-095-096.
&&
$$
UPDATE...RUBIN
SHORT TERM...SML
LONG TERM...ZF
AVIATION...RJM
FIRE WEATHER...SML
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
957 AM MST TUE DEC 15 2015
.UPDATE...
ISSUED AT 940 AM MST TUE DEC 15 2015
CONSENSUS DECISION AMONGST OUR TEAM THIS MORNING WAS TO UPGRADE
TO A WINTER STORM WARNING FOR OUR FOUR ZONES FROM THE SOUTHERN
LARAMIE RANGE AND SUMMIT...TO THE SOUTHERN LARAMIE RANGE
FOOTHILLS...CENTRAL AND EASTERN LARAMIE COUNTY INCLUDING CHEYENNE.
LATEST MEASUREMENTS INCLUDE 5 1/2 INCHES OF SNOW OFFICIALLY
IN CHEYENNE...AND WITH THE UPPER LOW SOMEWHAT SLOWER THAN MODELS
EARLIER DEPICTED...NICE SNOWFALL BANDING AS SEEN ON WSR-88D
REFLECTIVITY...AND PROJECTED HRRR HOURLY SNOWFALL RATES...WE FEEL
IT IS PRUDENT TO UPGRADE TO A WINTER STORM WARNING FOR
AFOREMENTIONED ZONES. PRESSURE GRADIENTS WILL SLOWLY INCREASE
THIS AFTERNOON AND NORTH WINDS EXPECTED TO INCREASE SLOWLY AND
COMBINED WITH WINDS AND TEMPERATURES FALLING INTO THE TEENS...
ALONG WITH FALLING AND BLOWING SNOW...VISIBILITIES WILL BE
OCCASIONALLY NEAR ZERO AT TIMES...ESPECIALLY WITH THE POWDERY
NATURE OF THE SNOW.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 436 AM MST TUE DEC 15 2015
STORM SYSTEM OVER COLORADO STILL ON TRACK TO PICK UP SPEED AND
SHIFT QUICKLY EAST INTO THE PLAINS TODAY. THE MAIN QUESTION AT
THIS TIME IS HOW MUCH WARP AROUND PRECIPITATION WILL OCCUR OVER
THE FORECAST AREA. ONE AREA THAT HAS NOT PICKED UP AS MUCH SNOW
AS EXPECTED IS INTO EAST CENTRAL WYOMING SUCH AS AROUND DOUGLAS.
AS OF 4 AM ONLY A DUSTING TO A HALF AN INCH OF SNOW WAS REPORTED
ACROSS CONVERSE COUNTY. THIS COMPARES TO 2 OR 5 INCHES THAT
SHOULD HAVE BEEN ON THE GROUND ACCORDING TO YESTERDAYS NUMERICAL
MODELS.
DOWNGRADED THE WINTER STORM WARNING TO AN ADVISORY FOR NIOBRARA
AND CONVERSE COUNTIES. ALSO THE NORTHERN LARAMIE RANGE IN THE
CHEYENNE FORECAST AREA IS ONLY SHOWING 3 TO 5 INCHES BASED ON
SNOTELS WHILE 6 TO 9 INCHES SHOULD HAVE ALREADY FALLEN. SHOULD
STILL SEE SOME LIGHT WRAP AROUND PRECIPITATION OVER THIS AREA
THROUGH THIS AFTERNOON BUT AGAIN THE MODELS ARE LIKELY OVERDOING
THE PRECIPITATION AMOUNTS...ESPECIALLY CONSIDERING HOW QUICKLY
THIS SYSTEM WILL SHIFT EAST AND LACK OF A DEEP MOISTURE SOURCE.
THE MAIN UPPER LEVEL SUPPORT CURRENTLY OVER FAR SOUTHEAST WYOMING
AND NE PANHANDLE WILL DECREASE THE REST OF TODAY...AND BY LATER
THIS MORNING DOWNSLOPE NORTHWEST WINDS WILL DEVELOP...MAKING IT
MORE DIFFICULT FOR ACCUMULATING SNOWS TO OCCUR IN SOUTHEAST
WYOMING. OF COURSE NORTHWEST WINDS FAVOR PLACES LIKE THE PINE
RIDGE FOR UPSLOPE SNOW ENHANCEMENT.
THE HIGHER SNOW AMOUNTS SHOULD GENERALLY BE FOUND OVER THE
NEBRASKA PANHANDLE. MODELS STILL PAINTING A LOT OF PRECIPITATION...
ESPECIALLY OVER THE SOUTHERN NEBRASKA PANHANDLE WHERE THE
STRONGEST LOWER TO MID LEVEL THETAE ADVECTION WILL OCCUR. GIVEN
THE FACT THAT SIDNEY SHOULD ALREADY HAVE .15 INCHES OF LIQUID AND
IS ONLY NOW STARTING TO SNOW...IT DOES NOT BODE WELL FOR THE
MODELS HAVING A GOOD HANDLE ON THE AMOUNT OF MOISTURE AVAILABLE.
THEREFORE THE CURRENT SNOW FORECAST VERY WELL COULD BE A FEW
INCHES TOO GENEROUS. REGARDLESS...THERE WILL BE ACCUMULATIONS OF
SNOW MAKING ROADS SNOW COVERED AND SLIPPERY. NOT EXPECTING MUCH IN
THE WAY OF BLOWING SNOW TODAY. OF COURSE THE SNOW WILL BE BLOWING
AS IT IS FALLING BUT AS FOR SNOW ON THE GROUND BE RELOFTED INTO
THE AIR THERE WILL GENERALLY NOT BE ENOUGH SNOW ON THE GROUND FOR
THAT TO OCCUR. GRANTED SOME BLOWING SNOW WILL OCCUR BUT THE BIGGER
FACTOR WILL BE DRIFTING. WINDS WILL BE STRONG ENOUGH TODAY TO
PRODUCE DRIFTS. SHOULD SEE ONE TO THREE FOOT HIGH DRIFTS DEPENDING
OF COURSE ON HOW MUCH SNOW FALLS AT ANY GIVEN LOCATION.
SNOW WILL BEGIN TO TAPER OFF FROM WEST TO EAST TODAY. MOST SNOW
ACCUMULATION WILL END BY EARLY THIS EVENING WITH SOME LIGHT SNOW
LINGERING INTO THE NORTHERN NEBRASKA PANHANDLE. WINDS WILL REMAINS
GUSTY THROUGH TONIGHT ACROSS THE PLAINS WITH RELATIVELY LIGHT
WINDS INTO SOUTH CENTRAL WY. WINDS WILL INCREASE ACROSS THE
ARLINGTON AREA TOMORROW NIGHT INTO WEDNESDAY. THAT IS A CONCERN
GIVEN THE NEW SNOW FALL IN THAT AREA. BLOWING SNOW MAY BECOME AN
ISSUE FOR SEVERAL HOURS WEDNESDAY MORNING AROUND ARLINGTON.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 340 AM MST TUE DEC 15 2015
THE MODELS HAVE BEEN PRETTY CONSISTENT AT SHOWING A SHORTWAVE DIVING
SOUTHEASTWARD FROM WYOMING INTO COLORADO ON THURS. THERE IS SOME
DECENT ASCENT IN AREAS ALONG INTERSTATE 80 ON THURS MORNING BEFORE
SUBSIDENCE ENSUES DURING THE AFTN. 700MB TEMPS ARE QUITE COLD (-
18C) BEHIND THE UPPER WAVE SO HIGHS WILL STRUGGLE TO GET OUT OF THE
LOW 20S. HEIGHTS RISE BY FRI AND A SFC TROUGH DEVELOPS ALONG THE
LARAMIE RANGE. THE 850MB CAG-CPR GRADIENT RISES TO AROUND 60 MTRS
AND WITH WARM AIR ADVECTION ALOFT...COULD SEE HIGH WINDS DEVELOP IN
THE ARLINGTON/VEDAUWOO AREAS. THE REAL WARMUP COMES ON SAT AS 700MB
TEMPS RISE TO 0C AND HIGHS WILL BE BACK INTO THE UPPER 40S TO THE
EAST OF THE LARAMIE RANGE. WHILE THERE COULD BE SOME STRONG WIND
GUSTS IN THE WIND PRONE AREAS...THE LLVL GRADIENT DOES NOT LOOK
STRONG ENOUGH TO SUPPORT A WIDESPREAD HIGH WIND EVENT OVER THESE
AREAS. TEMPS ON SUN/MON WILL BE SLIGHTLY COOLER AND THERE WILL BE
A CHANCE OF OROGRAPHIC SNOW IN THE SIERRA MADRE AND SNOWY RANGES
AS PACIFIC MOISTURE STREAMS INTO THE REGION IN INCREASING ZONAL
FLOW ALOFT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 453 AM MST TUE DEC 15 2015
WIDESPREAD IFR/LIFR CONDITIONS DUE TO SNOW WILL OCCUR THROUGH THE
AFTERNOON FOR MUCH OF THE SITES. BRIEF PERIODS OF MODERATE SNOW
WILL BE POSSIBLE ESPECIALLY TO THE EAST OF THE LARAMIE RANGE
...REDUCING VIS DOWN TO ONE HALF MILE. BREEZY NORTH WINDS WILL
ALSO OCCUR WITH GUSTS TO 25-30 KTS. THE SNOW WILL GRADUALLY TAPER
OFF BY THE AFTERNOON/EVENING.
&&
.FIRE WEATHER...
ISSUED AT 430 AM MST TUE DEC 15 2015
SNOW WILL SLOWLY TAPER OFF FROM WEST TO EAST ACROSS SOUTHEAST
WYOMING AND WESTERN NEBRASKA PANHANDLE TODAY INTO TONIGHT.
BLOWING AND DRIFTING SNOW.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR
WYZ101>103-106>108-115.
WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR WYZ116>119.
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR WYZ104-
105-109-111-113.
WINTER STORM WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ110-
112-114.
NE...WINTER STORM WARNING UNTIL 3 AM MST WEDNESDAY FOR NEZ002-003-
019>021-054-055-095-096.
&&
$$
UPDATE...RUBIN
SHORT TERM...SML
LONG TERM...ZF
AVIATION...ZF
FIRE WEATHER...SML
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
326 AM EST THU DEC 17 2015
.SYNOPSIS...
LOW PRESSURE AND A COLD FRONT WILL MOVE ACROSS OUR AREA LATE TODAY
AND EARLY TONIGHT. A STRONG AREA OF HIGH PRESSURE BUILDS TO OUR
SOUTH AND WEST FRIDAY AND SATURDAY, THEN BRIEFLY SETTLES OVER OUR
REGION SUNDAY BEFORE MOVING OFFSHORE. A WEAK COLD FRONT WILL
APPROACH ON TUESDAY, HOWEVER IT MAY STALL JUST TO OUR WEST BEFORE
ANOTHER COLD FRONT APPROACHES LATE WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DRY EARLY THIS MORNING. FOG SHOULD DEVELOP POCONOS AROUND 11Z.
RAIN HAS BEEN POPPED PER HRRR ONSET 12Z-15Z E PA THIS MORNING...
DELAYED SLIGHTLY FROM EARLIER FORECASTS THEN ROBUST 3-6 HR PERIOD
OF SHOWERY RAINS MIDDAY/MID AFTN EVERYWHERE.
SOME OF THE RAIN BRIEFLY HEAVY NEAR THE PATH OF THE SFC LOW IN
THE SLIGHTLY MORE UNSTABLE AIR AND THAT SHOULD BE NJ/DE AS PER THE
WPC QPF. MOST OF THE RAIN IN THE 15Z- 22Z TIME FRAME. SE WIND
BRIEFLY INCREASES DURING MIDDAY WITH GUSTS 20 MPH S NJ COAST AS
WELL AS DELAWARE, WHILE THE WIND IN E PA MAY TURN LIGHT NE. A WIND
SHIFT EVERYWHERE TO SOUTHWEST OR WEST LATE IN THE DAY WITH LOW
PRES AND A BROAD CFP PASSING THROUGH AND THEN EAST OF OUR COASTS.
HAVE ADDED FOG TO THE FORECAST THIS AFTN IN THE BROAD PATH OF LOW
PRES GRADIENT, ESPECIALLY SUNSET ONWARD WHEN DRY SLOT PASSES
THROUGH ALOFT. SOME OF THAT FOG COULD BE DENSE AND FORESEE A SPS
POTENTIAL FOR FOG LATE IN THE DAY.
FORECAST ELEMENTS WERE DERIVED FROM A 50 50 BLEND OF THE 00Z/17
GFS/NAM MOS. HOWEVER, BECAUSE OF WETBULBING AND RAIN, I BLENDED
THE TEMPS WITH THE COOLER NAM 2 M TEMPS.
AS FOR CLIMO...AM SO USED TO THIS WONDERFUL WONDERFUL WEATHERWE`VE
ENJOYED THIS UNUSUALLY WARM NOVEMBER-DECEMBER THAT I NEGLECT TO
MENTION...MAX TEMPS ABOUT 10F ABOVE NORMAL, AS IF THIS ISN`T
SPECIAL IN OUR NECK OF THE WOODS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
PROBABLY PATCHY FOG, POSSIBLY DENSE ALONG AND SE OF I-95 DURING THE
EVENING. LEFTOVER SHOWERS ALONG THE COASTS DURING THE EVENING.
DOUBTING IF ANY MEASURABLE RAIN AFTER MIDNIGHT. OTRW...MO CLOUDY.
WIND BECOMING NORTHWEST AND INCREASING AFTER MIDNIGHT WHEN THE
DEWPOINTS TUMBLE AND VSBY IMPROVES CONSIDERABLY.
FORECAST ELEMENTS WERE DERIVED FROM A 50 50 BLEND OF THE 00Z/17
GFS/NAM MOS.
CLIMO: LOWS ABOUT 15F WARMER THAN NORMAL.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF AN AMPLIFIED UPPER-LEVEL TROUGH
SETTLING INTO THE EAST FRIDAY NIGHT AND SATURDAY BEFORE LIFTING
NORTHEASTWARD SUNDAY. THIS DELIVERS MUCH COLDER AIR INTO THE EAST,
HOWEVER THE FLOW IS PROGRESSIVE AND THEREFORE THE COLD SHOT IS SHORT
IN DURATION. AS ENERGY ACROSS THE WEST MOVES INTO THE CENTRAL PLAINS
LATER IN THE WEEKEND, RIDGING RETURNS ACROSS THE EAST. THIS WILL
ALLOW A WARMING TREND TO OCCUR NEXT WEEK, WITH POTENTIALLY NEAR
RECORD WARMTH STARTING ON WEDNESDAY. THE MAIN WEATHER FEATURE IS A
FRONTAL ZONE WITH WAVES OF LOW PRESSURE ALONG IT OFFSHORE FRIDAY
NIGHT, THEN A POTENTIALLY SLOW MOVING FRONT ARRIVING TUESDAY INTO
THURSDAY. WE USED A MODEL BLEND FRIDAY THROUGH SUNDAY, THEN A 00Z
WPC/CONTINUITY BLEND THEREAFTER. SOME ADJUSTMENTS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.
FOR FRIDAY...THERE SHOULD BE GRADUAL CLEARING AS THE FRONT AND
SURFACE WAVE IS OFFSHORE, HOWEVER SOME OVERRUNNING WEST OF THE
BOUNDARY AS ANOTHER LOW RUNS UP THE FRONT COULD LINGER SOME SHOWERS
NEAR THE COAST IN THE MORNING. OVERALL THOUGH THE BULK OF THE
PRECIPITATION SHOULD REMAIN OFFSHORE, THEREFORE HELD ONTO SOME
SLIGHT CHC TO LOW CHC POPS IN THE MORNING MAINLY FROM THE COAST ON
EASTWARD. CAA ARRIVES THROUGH THE DAY AND REALLY KICKS IN BY LATE IN
THE DAY. THERE IS THE POTENTIAL FOR SOME FLURRIES OR SNOW SHOWERS
GETTING TO THE POCONOS LATER AT NIGHT AS A MUCH COLDER AIRMASS TURNS
THE LAKE EFFECT MACHINE ON. WE ARE ANTICIPATING A BREEZE, WHICH MAY
INCREASE SOME AS THE CAA DEEPENS AND THE PRESSURE GRADIENT TIGHTENS.
FOR SATURDAY AND SUNDAY...A STRONG UPPER-LEVEL TROUGH SWINGS ACROSS
THE EAST SATURDAY BEFORE LIFTING NORTHEASTWARD SUNDAY. THIS FEATURE
WILL HAVE MUCH COLDER AIR WITH IT, WITH STRONG CAA OCCURRING
SATURDAY WHICH THEN WEAKENS SATURDAY NIGHT AND THEN TRANSITIONS TO
WAA THEREAFTER. THE 850 MB TEMPERATURES ARE FORECAST TO BE NEAR
-12C SATURDAY BEFORE MODERATING, THEREFORE A MUCH COLDER DAY IS
EXPECTED. THE COMBINATION OF CAA AND A TIGHT PRESSURE GRADIENT WITH
STRONG HIGH PRESSURE TO OUR SOUTHWEST WILL RESULT IN BREEZY TO WINDY
CONDITIONS SATURDAY. THE FORECAST SOUNDINGS SHOW ABOUT 35 KNOTS OF
WIND IN THE MIXING LAYER, AND ATTM WE BUMPED THE GUSTS UP TO 30
KNOTS AT THE SURFACE. THE COMBINATION OF TEMPERATURES IN THE 30S AND
40S AND GUSTY WINDS WILL BRING COLD WIND CHILLS INTO THE PICTURE.
WHILE THIS COLD SHOT IS NOT VERY SIGNIFICANT FOR THIS TIME OF YEAR,
IT WILL BE A SHOCK GIVEN HOW WARM IT HAS BEEN THIS MONTH. IT LOOKS
LIKE PHILADELPHIA /THE AIRPORT/ SHOULD FINALLY GET BELOW 32 DEGREES
SATURDAY NIGHT.
THE COLD WEST TO NORTHWEST FLOW IS EXPECTED TO RESULT IN LAKE EFFECT
SNOW AND SOME OF THIS ACTIVITY SHOULD GET PULLED INTO NORTHEASTERN
PENNSYLVANIA SATURDAY, ALLOWING FOR SOME SNOW SHOWERS INTO AT LEAST
THE POCONOS. THERE COULD EVEN BE SOME FLURRIES FARTHER SOUTH AND
EAST, HOWEVER THE SUB-CLOUD LAYER /DEW POINTS DROPPING THROUGH THE
TEENS SATURDAY/ MAY BE TO DRY WITH A SOUTHERN EXTENT AND THEREFORE
DID NOT CARRY A MENTION TO FAR SOUTH AND EAST. IT IS POSSIBLE THAT A
SNOW SQUALL GETS TO THE POCONOS GIVEN THE INVERSION HEIGHT RISING
SOME AND THE LOW-LEVEL LAPSE RATES STEEPENING. HIGH PRESSURE THEN
BRIEFLY ARRIVES SUNDAY WITH LESS WIND AS THE UPPER-LEVEL TROUGH
LIFTS OUT, HOWEVER WE SHOULD START TO HAVE A RETURN FLOW BECOME
ESTABLISHED DURING SUNDAY AS THE UPPER-LEVEL FLOW IS PROGRESSIVE.
THIS ALLOWS FOR WAA TO OCCUR AND THEREFORE A REBOUND IN AFTERNOON
TEMPERATURES /MIXING WILL BE LESS THOUGH/.
FOR MONDAY THROUGH WEDNESDAY...AN UPPER-LEVEL RIDGE ACROSS THE EAST
WILL ALLOW FOR MILDER AIR, HOWEVER A SHORT WAVE TROUGH MAY SLIDE
NEARBY LATER MONDAY AND TUESDAY. THIS SHOULD SEND A WEAKENING COLD
FRONT TOWARD OUR AREA, HOWEVER IT MAY NOT COMPLETELY MAKE IT.
OVERALL A MILDER PATTERN IS EXPECTED AND THIS COULD RESULT IN NEAR
RECORD WARMTH STARTING WEDNESDAY. THERE IS MORE UNCERTAINTY HOWEVER
AS AT LEAST SOME MODEL GUIDANCE SHOWS A MORE ACTIVE FRONT TUESDAY
AND WEDNESDAY WITH SOME RIPPLES OF LOW PRESSURE ALONG IT. IF THIS
WERE TO OCCUR AND THEREFORE NOT KEEPING OUR AREA MORE INTO A CLEAN
WARM SECTOR, COOLER TEMPERATURES WILL RESULT /OUR SUPERBLEND TOOL IS
COOLER FOR WEDNESDAY/. WE OPTED TO LEAN CLOSER TO THE WPC GUIDANCE
ATTM WHICH FAVORS SOME SLOWNESS OF THE MAIN FRONT AS THE UPPER-LEVEL
FLOW COULD BE MORE AMPLIFIED AND THE SOUTHEAST RIDGE SHOULD PLAY A
ROLE.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY, AND SURROUNDING AREAS.
EARLY THIS MORNING PRIOR TO 12Z...MVFR CEILINGS N OF KPHL WHILE
ITS TEMPO VFR CIGS ELSEWHERE AS MID DECK CLOUDINESS ARRIVES
DELMARVA AND S NJ. LIGHT WIND.
TODAY AFTER 12Z...RAIN WILL MOVE IN RAPIDLY FROM THE SW DURING THE
MORNING. CONDS MAY BE LOWER-END MVFR BY THE TIME THE RAIN STARTS
AND WILL LIKELY DETERIORATE FURTHER FROM THERE INTO THE IFR RANGE
BY MID DAY WITH POTENTIAL FOR BRIEF LIFR CONDS IN ST/FOG NEAR THE
PATH OF THE LOW DURING THE AFTERNOON WHICH WOULD BE PHILLY AREA.
WINDS WILL BE FROM THE E TO SE BUT SHOULD REMAIN GENLY LESS THAN
10 KT EXCEPT POSSIBLY GUST 20 KT KACY MIDDAY. A COLD FRONT WILL
CROSS THE AREA LATE IN THE DAY WITH AN ASSOCD WIND SHIFT TO THE
SOUTHWEST OR WEST BUT LIGHT.
TONIGHT...PATCHY IFR/LIFR CONDS IN ST/FOG DURING THE EVENING,
ESPECIALLY KPHL SEWD. ANY LEFTOVER SHOWERS SHOULD END BY 02Z
VCNTY KACY. CONDITIONS IMPROVE TO VFR CIGS AOA 5000 FT LATE AT
NIGHT. WIND BECOMING NORTHWEST AND GRADUALLY INCREASES OVERNIGHT
WITH VSBY IMPROVING CONSIDERABLY AFTER 05Z/18.
OUTLOOK...
FRIDAY...OVERALL VFR AS SOME CLEARING TAKES PLACE FROM WEST TO EAST.
NORTHWESTERLY WINDS 10-15 KNOTS AND GUSTY AT TIMES.
SATURDAY...VFR. WEST-NORTHWEST WINDS 15-20 KNOTS WITH GUSTS TO 30
KNOTS, DIMINISHING AT NIGHT AND BECOMING WEST-SOUTHWEST.
SUNDAY AND MONDAY...VFR OVERALL, ALTHOUGH A FEW SHOWERS ARE
POSSIBLE LATE MONDAY. SOUTH-SOUTHWEST WINDS NEAR 10 KNOTS.
&&
.MARINE...
ISSUING A FIRST PERIOD SCA FOR THE COASTAL WATERS OF LITTLE EGG
INLET NJ (VCNTY KACY) SOUTHWARD TO DE IN THE MIDDAY-AFTERNOON HOURS
FOR BRIEF INFLOW GUST 20-25 KT AND SEAS RISING TO NEAR 5 FT ON THE
ATLC WATERS. THIS IS ISSUED WITH LESS THAN 80 PCT CONFIDENCE OF
OCCURRENCE BUT ITS BASICALLY OFFERED AS SOME LEAD TIME. THE HRRR
HAS SOME DECENT INFLOW WIND AROUND 17Z-20Z. USUALLY HRRR WINDS ARE
A BIT OVERDONE BUT IN THIS CASE, SHAVED 5 FT AND STILL GET 25 KT
GUSTS.
OTRW...CONDS SHOULD REMAIN SUB-SCA THROUGH TODAY NNJ WATERS AS
WELL AS DELAWARE BAY.
FOG MAY BECOME A MARINE TRANSPORTATION HAZARD LATE THIS AFTERNOON?
TONIGHT...NO SCA ANTICIPATED IN DEVELOPING NORTHWEST FLOW FOR THE
NNJ AND DE BAY WATERS BUT THE SCA MAY STILL BE NEEDED FOR THE ATLC
WATERS OF S NJ AND DE WHERE SEAS WILL BE AROUND 5 FT. DENSE FOG
MAY BE A MARINE TRANSPORTATION FACTOR THIS EVENING.
OUTLOOK...
FRIDAY THROUGH SATURDAY NIGHT...STRONG CAA AND A TIGHTENING PRESSURE
GRADIENT WILL ALLOW THE MIXING TO DEEPEN. THIS WILL RESULT IN GUSTS
TO 30 KNOTS MAINLY STARTING FRIDAY EVENING, HOWEVER A PERIOD OF
GALE FORCE GUSTS MAY OCCUR FRIDAY NIGHT AND SATURDAY. A SMALL
CRAFT ADVISORY IS LIKELY AND A GALE WATCH IS POSSIBLE. THE WINDS
DIMINISH SOME BY LATE SATURDAY NIGHT.
SUNDAY...NORTHWEST WINDS ARE EXPECTED TO WEAKEN AND SHIFT TO
SOUTHWESTERLY, HOWEVER CONDITIONS MAY BE CLOSE TO SMALL CRAFT
ADVISORY CRITERIA FOR A TIME.
MONDAY...A SOUTHWESTERLY FLOW SHOULD GUST TO ABOUT 25 KNOTS, HOWEVER
THE AIRMASS IS WARMING AND THIS COULD REDUCE THE OVERALL MIXING.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 PM EST THIS
AFTERNOON FOR ANZ452>455.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG
SHORT TERM...DRAG
LONG TERM...GORSE
AVIATION...DRAG/GORSE
MARINE...DRAG/GORSE
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
238 AM EST THU DEC 17 2015
.SYNOPSIS...
LOW PRESSURE AND A COLD FRONT PASS THROUGH THE MID ATLANTIC STATES
LATE TODAY AND TONIGHT. HIGH PRESSURE WILL BEGIN TO BUILD INTO
THE REGION ON FRIDAY FROM THE SOUTHERN PLAINS, FINALLY SETTLING
OVER THE MIDDLE ATLANTIC ON SUNDAY. A WEAK COLD FRONT WILL CROSS
OUR REGION ON MONDAY NIGHT, THEN RETURN NORTH AS A WARM FRONT ON
TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TODAY/...
DRY EARLY THIS MORNING. FOG SHOULD DEVELOP POCONOS AROUND 11Z.
RAIN HAS BEEN POPPED PER HRRR ONSET 12Z-15Z E PA THIS MORNING...
DELAYED SLIGHTLY FROM EARLIER FORECASTS THEN ROBUST 3-6 HR PERIOD
OF SHOWERY RAINS MIDDAY/MID AFTN EVERYWHERE.
SOME OF THE RAIN BRIEFLY HEAVY NEAR THE PATH OF THE SFC LOW IN
THE SLIGHTLY MORE UNSTABLE AIR AND THAT SHOULD BE NJ/DE AS PER THE
WPC QPF. MOST OF THE RAIN IN THE 15Z- 22Z TIME FRAME. SE WIND
BRIEFLY INCREASES DURING MIDDAY WITH GUSTS 20 MPH S NJ COAST AS
WELL AS DELAWARE, WHILE THE WIND IN E PA MAY TURN LIGHT NE. A WIND
SHIFT EVERYWHERE TO SOUTHWEST OR WEST LATE IN THE DAY WITH LOW
PRES AND A BROAD CFP PASSING THROUGH AND THEN EAST OF OUR COASTS.
HAVE ADDED FOG TO THE FORECAST THIS AFTN IN THE BROAD PATH OF LOW
PRES GRADIENT, ESPECIALLY SUNSET ONWARD WHEN DRY SLOT PASSES
THROUGH ALOFT. SOME OF THAT FOG COULD BE DENSE AND FORESEE A SPS
POTENTIAL FOR FOG LATE IN THE DAY.
FORECAST ELEMENTS WERE DERIVED FROM A 50 50 BLEND OF THE 00Z/17
GFS/NAM MOS. HOWEVER, BECAUSE OF WETBULBING AND RAIN, I BLENDED
THE TEMPS WITH THE COOLER NAM 2 M TEMPS.
AS FOR CLIMO...AM SO USED TO THIS WONDERFUL WONDERFUL WEATHERWE`VE
ENJOYED THIS UNUSUALLY WARM NOVEMBER-DECEMBER THAT I NEGLECT TO
MENTION...MAX TEMPS ABOUT 10F ABOVE NORMAL, AS IF THIS ISN`T
SPECIAL IN OUR NECK OF THE WOODS.
&&
.SHORT TERM /TONIGHT/...
PROBABLY PATCHY FOG, POSSIBLY DENSE ALONG AND SE OF I-95 DURING THE
EVENING. LEFTOVER SHOWERS ALONG THE COASTS DURING THE EVENING.
DOUBTING IF ANY MEASURABLE RAIN AFTER MIDNIGHT. OTRW...MO CLOUDY.
WIND BECOMING NORTHWEST AND INCREASING AFTER MIDNIGHT WHEN THE
DEWPOINTS TUMBLE AND VSBY IMPROVES CONSIDERABLY.
FORECAST ELEMENTS WERE DERIVED FROM A 50 50 BLEND OF THE 00Z/17
GFS/NAM MOS.
CLIMO: LOWS ABOUT 15F WARMER THAN NORMAL.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
LONG-WAVE MID-LEVEL TROUGH DIGS IN THE EAST ON FRIDAY AND SATURDAY,
LIFTING INTO THE CANADIAN MARITIMES BY SUNDAY. THE MID-LEVEL RIDGE
WILL CREST OVER THE MIDDLE ATLANTIC SUNDAY NIGHT, WITH A SOUTHWEST
ALOFT SETTING UP THEREAFTER. AFTER NEAR "AVERAGE" TEMPERATURES THIS
WEEKEND, ABOVE NORMAL TEMPERATURES ARE EXPECTED TO RETURN NEXT WEEK.
THURSDAY NIGHT AND FRIDAY...A COLD FRONT WILL MOVE SLOWLY OFFSHORE,
WITH POPS FOR RAIN SHOWERS DECREASING FROM WEST TO EAST THU NIGHT.
ON FRIDAY, WE KEPT POPS OVER EASTERN NJ AND SOUTHERN DE, WHERE SOME
OVERRUNNING TAKES PLACE AS, LOW PRESSURE MOVES ALONG AFOREMENTIONED
FRONT.
FRIDAY NIGHT AND SATURDAY...CYCLONIC FLOW ALOFT AS STRONG COLD AIR
ADVECTION TAKES PLACE. THERE WILL BE PARTIAL CLEARING FRIDAY NIGHT
WITH PARTLY SUNNY SKIES EXPECTED FOR SATURDAY. WITH THE TRAJECTORY
OFF THE GREAT LAKES, CANNOT RULE OUT SOME SNOW SHOWERS MOVING INTO
THE POCONOS, WITH THE CURRENT FORECAST REFLECTING THIS. STEEP LOW-
LEVEL LAPSE RATES WILL ALSO LEAD TO NORTHWEST GUSTINESS, UP TO 35
MPH AT TIMES. HIGH TEMPERATURES WILL RANGE FROM THE LOWER 30S TO
LOWER 40S, MAKING FOR WIND CHILL FACTORS WILL BE IN THE 20S.
SUNDAY AND MONDAY...HIGH PRESSURE CRESTS OVER THE REGION ON SUNDAY,
WITH A RETURN SOUTHWEST FLOW ON MONDAY. THERE IS A LOW POTENTIAL OF
FOG BOTH MORNINGS, ESPECIALLY NORTHWEST OF I-95. OTHERWISE, MOSTLY
SUNNY ON SUNDAY AND DRY. A WEAK COLD FRONT APPROACHING WILL LEAD TO
INCREASING CLOUDS AND THE CHANCE OF RAIN SHOWERS ON MONDAY.
MONDAY NIGHT THROUGH WEDNESDAY...A WEAK COLD FRONT CROSSES THE AREA
MONDAY NIGHT, ONLY TO MOVE NORTHWARD AS A WARM FRONT TUESDAY NIGHT.
A WAVE OF LOW PRESSURE MAY MOVE ALONG THIS FRONT ON WEDNESDAY, WITH
THE POSSIBILITY OF HEAVIER RAIN, ALTHOUGH UNCERTAIN GIVEN THE DAY 7
TIME FRAME. OVERALL, A MOIST SOUTHWEST FLOW DURING THIS PERIOD MAY
INHIBIT TEMPERATURES FROM REACHING THEIR FULL /RECORD/ POTENTIAL.
THIS WAS NOT THE CASE THIS PAST WEEKEND INTO EARLIER THIS WEEK AS
THE WAS RIDGE OVERHEAD WITH SUBSEQUENT SUBSIDENCE.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY, AND SURROUNDING AREAS.
EARLY THIS MORNING PRIOR TO 12Z...MVFR CEILINGS N OF KPHL WHILE
ITS TEMPO VFR CIGS ELSEWHERE AS MID DECK CLOUDINESS ARRIVES
DELMARVA AND S NJ. LIGHT WIND.
TODAY AFTER 12Z...RAIN WILL MOVE IN RAPIDLY FROM THE SW DURING THE
MORNING. CONDS MAY BE LOWER-END MVFR BY THE TIME THE RAIN STARTS
AND WILL LIKELY DETERIORATE FURTHER FROM THERE INTO THE IFR RANGE
BY MID DAY WITH POTENTIAL FOR BRIEF LIFR CONDS IN ST/FOG NEAR THE
PATH OF THE LOW DURING THE AFTERNOON WHICH WOULD BE PHILLY AREA.
WINDS WILL BE FROM THE E TO SE BUT SHOULD REMAIN GENLY LESS THAN
10 KT EXCEPT POSSIBLY GUST 20 KT KACY MIDDAY. A COLD FRONT WILL
CROSS THE AREA LATE IN THE DAY WITH AN ASSOCD WIND SHIFT TO THE
SOUTHWEST OR WEST BUT LIGHT.
TONIGHT...PATCHY IFR/LIFR CONDS IN ST/FOG DURING THE EVENING,
ESPECIALLY KPHL SEWD. ANY LEFTOVER SHOWERS SHOULD END BY 02Z
VCNTY KACY. CONDITIONS IMPROVE TO VFR CIGS AOA 5000 FT LATE AT
NIGHT. WIND BECOMING NORTHWEST AND GRADUALLY INCREASES OVERNIGHT
WITH VSBY IMPROVING CONSIDERABLY AFTER 05Z/18.
OUTLOOK...
FRIDAY...MVFR POSSIBLE IN SHRA...OTHERWISE VFR.
FRIDAY NIGHT AND SATURDAY...VFR CONDITIONS. NORTHWEST WIND GUSTS
TO 30 KNOTS POSSIBLE AT ALL TERMINALS.
SATURDAY NIGHT THRU SUNDAY NIGHT...VFR CONDITIONS EXPECTED.
MONDAY...MVFR IN SHRA...OTHERWISE VFR.
&&
.MARINE...
ISSUING A FIRST PERIOD SCA FOR THE COASTAL WATERS OF LITTLE EGG
INLET NJ (VCNTY KACY) SOUTHWARD TO DE IN THE MIDDAY-AFTERNOON HOURS
FOR BRIEF INFLOW GUST 20-25 KT AND SEAS RISING TO NEAR 5 FT ON THE
ATLC WATERS. THIS IS ISSUED WITH LESS THAN 80 PCT CONFIDENCE OF
OCCURRENCE BUT ITS BASICALLY OFFERED AS SOME LEAD TIME. THE HRRR
HAS SOME DECENT INFLOW WIND AROUND 17Z-20Z. USUALLY HRRR WINDS ARE
A BIT OVERDONE BUT IN THIS CASE, SHAVED 5 FT AND STILL GET 25 KT
GUSTS.
OTRW...CONDS SHOULD REMAIN SUB-SCA THROUGH TODAY NNJ WATERS AS
WELL AS DELAWARE BAY.
FOG MAY BECOME A MARINE TRANSPORTATION HAZARD LATE THIS AFTERNOON?
TONIGHT...NO SCA ANTICIPATED IN DEVELOPING NORTHWEST FLOW FOR THE
NNJ AND DE BAY WATERS BUT THE SCA MAY STILL BE NEEDED FOR THE ATLC
WATERS OF S NJ AND DE WHERE SEAS WILL BE AROUND 5 FT. DENSE FOG
MAY BE A MARINE TRANSPORTATION FACTOR THIS EVENING.
OUTLOOK...
FRIDAY...SUB SMALL CRAFT ADVISORY /SCA/ CONDITIONS EXPECTED.
FRIDAY NIGHT THRU SATURDAY NIGHT...NORTHWEST WINDS ARE EXPECTED TO
REACH SCA CRITERIA. THERE IS ALSO THE POTENTIAL FOR GALE FORCE
GUSTS.
SUNDAY...NORTHWEST WINDS ARE EXPECTED TO WEAKEN BUT MAY REMAIN AT
SCA CRITERIA.
MONDAY...THERE IS A LOW PROBABILITY THAT SOUTHWEST WINDS MAY REACH
SCA CRITERIA.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...FRANCK
NEAR TERM...DRAG 239
SHORT TERM...DRAG 239
LONG TERM...FRANCK
AVIATION...DRAG/FRANCK 239
MARINE...DRAG/FRANCK 239
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
316 AM CST THU DEC 17 2015
.SHORT TERM...(Today)
ISSUED AT 316 AM CST THU DEC 17 2015
Cold front has passed well east of Illinois early this morning:
however, a large area of low clouds behind the boundary is
currently filtering into the area from the northwest. 09z/3am IR
satellite imagery shows the leading edge of the clouds along a
Champaign to Taylorville line...with overcast conditions upstream
across Iowa into the eastern Dakotas. HRRR has been handling the
clouds relatively well throughout the evening and shows them
spreading across the entire KILX CWA by 14/15z. Once the clouds
arrive, they will be very slow to depart...as NAM forecast
soundings indicate a persistent moist layer at around 925mb
through Friday morning. Thanks to cloudy skies and a chilly
northwesterly breeze of 10 to 15mph, high temperatures will be
near normal for this time of year. Have undercut MAV guidance
numbers by a couple of degrees, with readings mainly in the middle
to upper 30s.
&&
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 316 AM CST THU DEC 17 2015
As mentioned in the short-term discussion, forecast soundings
suggest clouds will stick around through tonight before slowly
clearing from southwest to northeast across the area on Friday.
Short-wave trough evident on latest water vapor imagery over western
Wyoming will track southeastward into the Southern Plains this
evening then into the Tennessee River Vally by Friday morning. This
feature will remain well to the S/SW of Illinois and will not play a
factor in the weather across the KILX CWA. As a result, am
expecting a cold/dry day on Friday with highs once again remaining
in the 30s. As surface high pressure approaches from the west,
clearing skies and diminishing winds will allow low temperatures
Saturday morning to bottom out in the teens and lower 20s.
Once high pressure shifts east of the region, southerly return flow
will lead to a warming trend by Sunday. Gusty southwesterly
winds ahead of the next approaching cold front will boost high
temperatures into the upper 40s and lower 50s. 00z Dec 17 models
are in excellent agreement concerning the frontal boundary
expected to pass through central Illinois early Monday. Thanks
to a strong flow northward from the Gulf of Mexico, it appears
the front will have enough moisture to work with to trigger
scattered showers Sunday night into Monday morning. Front will
then quickly exit into Indiana, leading to a period of dry
weather Monday afternoon/night.
After that, model solutions diverge next week as W/SW upper flow
allows a series of systems to impact the region. Timing and
strength of these features remain in question, with the GFS showing
dry conditions Tuesday followed by a period of rain Wednesday into
early Thursday...while the ECMWF shows rain on Tuesday and again on
Wednesday. With such significant model spread still present, opted
to make only minor changes to the extended forecast beyond Monday.
Will keep PoPs in the slight chance category through much of the
period...but will highlight Tuesday night through Wednesday night as
the most likely period for rain with 40-50 PoPs. Regardless of
which model verifies, the main story next week will be the warmer
temperatures. All solutions show ridging across the eastern CONUS
and unseasonably warm 850mb temps, which will lead to highs well
into the 40s and 50s Monday through Wednesday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1152 PM CST WED DEC 16 2015
Mostly VFR conditions this evening will be replaced by MVFR
ceilings late in the night as low level cloud cover continues to
push into central IL in NW flow. Front edge of this cloud cover
has tended to erode through central IL this evening and aside from
KPIA-KBMI northward has continued with VFR category ceilings. As
the pattern continues overnight...cloud cover should continue to
become more continuous and spread farther southeast. By
12Z...expecting MVFR cigs across the central IL terminals
according to model data and progression of upstream observations.
Winds WNW 10-15 kts through the next 24 hours.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Onton
AREA FORECAST DISCUSSION
NWS DES MOINES IA
321 AM CST THU DEC 17 2015
.SHORT TERM /TODAY/...
ISSUED AT 315 AM CST THU DEC 17 2015
CLOUDS EXPECTED TO HOLD ON THROUGH AREA GOOD HARE OF THE
DAY...THOUGH DRIER AIR ATTEMPTING TO PUNCH INTO WESTERN PORTION OF
THE FORECAST AREA BETWEEN 16Z AND 21Z THIS AFTERNOON. HRRR AND
RAP13 BOTH HINT AT CLEARING AREA IN WESTERN DAKOTAS NOW WILL REACH
THE WEST BY LATE MORNING. COMPLICATING MATTERS...IS ANOTHER WEAK
SHORT WAVE BEHIND THE MAIN UPPER LOW. THIS WILL REACH THE NORTHERN
COUNTIES BETWEEN 21 AND 00Z THIS AFTERNOON. NAM SHOWS SLIGHTLY
BETTER MOISTURE WITH THE FEATURE AND A HINT AT SOME MINOR
INSTABILITY BY THEN AS WELL. UPSTREAM NOW...SCATTERED LIGHT
FLURRIES AND SOME BLOWING SNOW REPORTED. WILL ADD FLURRIES FAR
NORTHWEST BETWEEN 21 AND 00Z AS THE WEAK WAVE APPROACHES.
OTHERWISE ...TEMPERATURES WILL BE MORE SEASONAL WITH HIGHS IN THE
UPPER 20S NORTH TO MID 30S IN THE SOUTH. NORTHWEST WINDS WILL
INCREASE AGAIN THIS AFTERNOON AS MIXING BEGINS. BETTER WINDS AND
GUSTS ACROSS THE NORTH WITH AMBIENT FLOW OF AROUND 20 MPH AND
GUSTS TO NEARER 30 MPH AT TIMES TODAY.
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 315 AM CST THU DEC 17 2015
MAIN FORECAST CONCERN WAS FOCUSED ON SNOW SQUALL POTENTIAL AND
GUSTY WINDS FRIDAY OVER NORTHERN IOWA AND TEMPERATURES THROUGH
THE WEEKEND AND INTO NEXT WEEK. MODELS ARE COMING INTO SLIGHTLY
BETTER AGREEMENT WITH SYSTEM SUNDAY NIGHT INTO MONDAY AND UTILIZED
A GFS20/ECMWF BLEND SUNDAY INTO NEXT WEEK. TONIGHT INTO
SATURDAY...USED A NAM12/SREF/GFS20 BLEND.
TONIGHT INTO FRIDAY...UPPER LEVEL TROUGH WILL CONTINUE TO MOVE
ACROSS THE REGION TONIGHT INTO FRIDAY...WITH A SECONDARY PUSH OF CAA
ANTICIPATED VIA A FAIRLY STRONG PV ANOMALY IS EXPECTED LATE FRIDAY
MORNING. CONCERNED FOR POTENTIAL FOR SNOW SQUALLS OVER NORTHERN
IOWA LATE FRIDAY MORNING INTO THE AFTERNOON. NAM/GFS BUFR
SOUNDINGS SATURATE THE DENDRITIC LAYER B/T 15-21Z AND WINDS ATOP
THE MIXED LAYER RANGE AROUND 30-35 KNOTS. DECENT FORCING
ASSOCIATED WITH THE PV ANOMALY ALONG WITH SOME WEAK ELEVATED
INSTABILITY PRESENT TOWARDS THE AFTERNOON HOURS OVER NORTHERN
IOWA. ALBEIT THE NAM12 IS LIKELY OVERDOING THE INSTABILITY.
HOWEVER...THERE WAS ENOUGH OF A SIGNAL TO AT LEAST INCREASE
WORDING TO PERIODS OF SNOW SHOWERS ON FRIDAY. LOW CONFIDENCE IN
ANY SNOW ACCUMULATION AND THUS LEFT OUT POPS. CERTAINLY COULD HAVE
GONE WITH THE CATEGORICAL POPS/LOW QPF SCENARIO AND SOMETHING TO
CONSIDER NEXT FORECAST PACKAGE IF MODELS CONTINUE WITH THIS
SIGNAL. SOUNDINGS QUICKLY LOSE THEIR MOISTURE PAST 21Z FRIDAY AND
ONLY HAVE FLURRIES MENTIONED AFTER THIS TIME FRAME.
FRIDAY NIGHT INTO SUNDAY...SURFACE HIGH PRESSURE BUILDS INTO THE
STATE AND CENTERS ITSELF OVER THE FORECAST AREA BY SATURDAY MORNING.
THIS WILL PROVIDE GOOD RADIATION COOLING AND LOWERED TEMPERATURES
2 TO 4 DEGREES ACROSS THE FORECAST AREA. THINKING THE GFS IS TOO
COLD...BUT ECMWF/NAM WERE IN GOOD AGREEMENT FOR LOWS SATURDAY
MORNING.
TEMPERATURES LOOK TO QUICKLY REBOUND ON SATURDAY AS WAA DEVELOPS
LATE SATURDAY MORNING AS THE SURFACE MOVES EAST. THE WAA PERSISTS
INTO SUNDAY AND HAVE A NON-DIURNAL TEMPERATURE TREND GOING
SATURDAY NIGHT INTO SUNDAY. THIS RESULTED IN INCREASING MINIMUM
TEMPERATURES SATURDAY NIGHT AND MAXIMUM TEMPERATURES ON SUNDAY.
SURFACE LOW PRESSURE EJECTS OUT OF THE CENTRAL ROCKIES WITH A
POTENT 500MB VORT MAX TRAILING BEHIND IT ON SUNDAY. THE PHASING
BETWEEN THE TWO COME TOGETHER EAST OF THE FORECAST AREA BY SUNDAY
NIGHT AS THE LOW DEEPENS OVER THE GREAT LAKES REGION. THUS...THE
BEST FORCING TRAILS BEHIND THE DEEPEST MOISTURE IN EASTERN IOWA
AND HAVE LOW POPS GOING SUNDAY INTO SUNDAY NIGHT.
MONDAY INTO WEDNESDAY...MONDAY WILL BE COOLER AS CAA CONTINUES
THROUGH MUCH OF THE DAY BEFORE WEAKENING BY THE LATE AFTERNOON.
AFTER A QUIET DAY TUESDAY...STRONG WAA AND THETA-E ADVECTION
DEVELOP ON WEDNESDAY AHEAD OF A DEEPENING LOW PRESSURE SYSTEM OVER
THE DAKOTAS. HOWEVER...GFS/ECMWF REMAIN IN DISAGREEMENT TIMING AND
LOCATION AS ECMWF IS FURTHER NORTH AND SLIGHTLY FASTER IN THE
PROGRESSION. POTENTIAL FOR SOME LIGHT PRECIP OVER EASTERN AND
NORTHERN PORTIONS OF THE FORECAST AREA WEDNESDAY INTO THURSDAY.
&&
.AVIATION...17/06Z
ISSUED AT 1124 PM CST WED DEC 16 2015
STRATUS WILL KEEP CONDITIONS MVFR THROUGH BEGINNING OF PERIOD AT
SITES. EXPECT CEILINGS TO LIFT TO VFR NEAR 00Z AT SITES...THOUGH
SOONER AT KOTM. WINDS WILL BE FROM THE NORTHWEST AND STRONG...WITH
GUSTS UP TO 25KTS POSSIBLE. WINDS WILL REMAIN STRONG THROUGH
PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...PODRAZIK
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
206 AM MST THU DEC 17 2015
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 205 AM MST THU DEC 17 2015
EARLY MORNING WV IMAGERY SLOWS SHORTWAVE TROUGH OVER
WYOMING/NORTH CENTRAL COLORADO MOVING TO THE SOUTHEAST. RAP UPPER
LEVEL ANALYSIS SHOWS STRONG H3 JET (100-120KT) UPSTREAM OF THIS
FEATURE MOVING INTO WESTERN WYOMING. LARGE SCALE PATTERN IS
DOMINATED BY AMPLIFYING RIDGE ALONG WESTERN US COAST AND LONGWAVE
TROUGH ACROSS THE CENTRAL US. LIGHT SNOW IS ALREADY BEING REPORTED
AT AKRON COLORADO UPSTREAM FROM OUR CWA.
TODAY-TONIGHT...UPPER LEVEL SHORTWAVE TROUGH IS SHOWN TO SPLIT
AROUND OUR CWA WITH STRONGEST FORCING STARTING TO OUR
WEST/NORTHWEST AND THEN TRENDING TO THE SOUTHEAST WITH MEAN FLOW
THROUGH THIS AFTERNOON AND EVENING. BEST FORCING APPEARS TO BE
MIDDAY THROUGH THE AFTERNOON...THOUGH NOSE OF UPPER LEVEL JET WILL
ACTUALLY BE PASSING THROUGH THE REGION THIS EVENING. GFS INITIATED
WITH A LITTLE MORE MOISTURE THAN 00Z SOUNDINGS WOULD HAVE
INDICATED AND NAM/RAP MOISTURE PROFILES WERE FAVORED. THIS WILL BE
CRITICAL AS MOISTURE APPEARS TO BE THE LIMITING FACTOR OF
DURATION/EXTENT OF SNOWFALL TODAY. RAP/NAM SUPPORT SATURATION
AROUND OR AFTER 18Z IN THE CENTRAL PART OF OUR FORECAST
AREA...WITH A 3HR PERIOD OF LIGHT QPF TRANSLATING ACROSS THE
AREA. WITH UPSTREAM OBS ALREADY SHOWING LIGHT SNOW I SHOWED A
SLIGHTLY FASTER TREND IN THE NORTHWEST. I THEN USED 925-700 MB
LAYER QG FRONTOGENESIS AND RH A GOOD PROXY FOR TRACK OF THIS AREA
OF SNOWFALL.
THE AIR MASS ALREADY IN PLACE IS COLD ENOUGH THAT WHEN SATURATED WE
SHOULD SEE ALL SNOW...AND WITH CAA THROUGH THE AFTERNOON HIGHER
RATIOS SHOULD BE SUPPORTED. VERY DRY AIR ADVECTS BACK INTO THE
REGION BEHIND THIS FAST MOVING SHORTWAVE SO BY EARLY THIS EVENING
PRECIP SHOULD BE WINDING DOWN FROM THE NORTHWEST TO THE SOUTHEAST.
BASED ON LATEST CONSENSUS QPF AND SNOW-LIQUID RATIOS IN THE 15-18
RANGE WE SHOULD SEE ACCUMULATIONS IN THE 0.5-1.5" RANGE...BEST
CHANCES ALONG A WRAY TO RUSSEL SPRINGS LINE. WHILE BRIEF
VISIBILITY REDUCTIONS ARE POSSIBLE...THEY SHOULDN`T BE WIDESPREAD
OR PERSISTENT CONSIDERING LIMITED WINDS DURING THE EVENT (WINDS DO
INCREASE SOME BEHIND SHORTWAVE). I PLAN ON KEEPING MENTION
LIMITED TO HWO.
FRIDAY-SATURDAY NIGHT...UPPER LEVEL RIDGING BUILDS ACROSS THE
CENTRAL ROCKIES/PLAINS FRIDAY AND SHIFTS EAST WITH SW FLOW
DEVELOPING SATURDAY. THIS WILL SUPPORT DRY CONDITIONS THROUGH THESE
PERIODS WITH WARMER TEMPERATURES. DEPENDING ON ANY SNOW PACK FRIDAY
WARM UP MAY BE TEMPERED SLIGHTLY...THOUGH POTENTIAL FOR HIGHS IN THE
LOWER 50S EXISTS. SATURDAY SHOULD BE MILD WITH STRONGER LEE TROUGH
DEVELOPMENT AND SW FLOW SUPPORTING STRONGER WAA. STATISTICAL
GUIDANCE HAS TRENDED TOWARDS LOW TO MID 50S...AND THIS SEEMS
REASONABLE CONSIDERING TEMPS ALOFT AND PATTERN.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 144 AM MST THU DEC 17 2015
FORECAST PROBLEM...ALBEIT A MINOR ONE...IS A LOW CHANCE OF
PRECIPITATION TOWARD THE END OF THIS PERIOD. SATELLITE CURRENTLY
SHOWING AN AMPLIFIED PATTERN FROM THE CENTRAL PACIFIC INTO THE
CENTRAL ATLANTIC.
IN GENERAL THE PATTERN THIS PERIOD WILL BE PROGRESSIVE AND NEARLY
ZONAL AT TIMES. A NUMBER OF FAST MOVING OPEN TROUGHS MOVE THROUGH
DURING THIS TIME. THE FIRST ONE IS ON SUNDAY. THE ECMWF/GFS SPIT OUT
A FEW HUNDREDTHS OF QPF. HOWEVER LOOKING AT THE SOUNDINGS THERE IS A
VERY DEEP DRY LAYER IN PLACE. SO LEFT ALONE THE DRY FORECAST THE
INIT GAVE ME.
A TROUGH COMES ACROSS ON WEDNESDAY AND THE INIT GAVE ME SOME SLIGHT
CHANCE POPS IN THE WEST AND THAT LOOKS REASONABLE. OVERALL MADE NO
CHANGES TO WHAT THE INIT GAVE ME. HOWEVER GIVEN THE FAST WESTERLY
PATTERN WOULD NOT BE SURPRISED IF HIGH TEMPERATURES END UP BEING
A LITTLE WARMER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1030 PM MST WED DEC 16 2015
KGLD...VFR CONDITIONS EXPECTED FROM TAF ISSUANCE THROUGH 17Z.
WINDS BEGIN FROM THE NORTHWEST UNDER 10KTS BECOMING NORTH AROUND
6KTS BY 16Z. FROM 17Z-23Z CONFIDENCE INCREASING FOR CIGS TO LOWER
INTO THE IFR CATEGORY WITH LIGHT TO POSSIBLY MODERATE SNOW AND
REDUCED VISIBILITIES FOR A FEW HOURS AS A WEATHER DISTURBANCE
MOVES SOUTHEAST ACROSS THE AREA. WINDS FROM THE NORTH GUSTING NEAR
20KTS. FROM 00Z-01Z CIGS SLIGHTLY IMPROVE TO MVFR CATEGORY WITH
WINDS FROM THE NORTHWEST AROUND 6KTS. AFTER 02Z VFR CONDITIONS
RETURN AS THE WEATHER DISTURBANCE CLEARS THE AREA AND WINDS BACK
TO THE WEST NEAR 6KTS.
KMCK...VFR CONDITIONS EXPECTED FROM TAF ISSUANCE THROUGH 16Z.
WINDS BEGIN THE PERIOD FROM THE WEST NEAR 7KTS BUT SHIFT TO THE
NORTHWEST 5-10KTS AFTER 10Z. FROM 17Z-21Z SIMILAR SCENARIO AS KGLD
WITH MVFR CATEGORY CIGS/VIS AS LIGHT SNOW MOVES ACROSS THE AREA.
WINDS GENERALLY FROM THE NORTHWEST NEAR 10KTS. VFR CONDITIONS
RETURN AROUND 22Z WITH WINDS CONTINUING FROM THE NORTHWEST NEAR
10KTS. AFTER 00Z WINDS BACK TO THE WEST NEAR 7KTS WITH A CLEAR SKY
OVERHEAD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...99
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
135 AM CST THU DEC 17 2015
...updated short and long...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 123 AM CST THU DEC 17 2015
An upper level disturbance will approach the region from the northwest
this morning and move across the state through today. This will lead
to some snow showers across the region. Moisture is mainly rooted in
the 850-600-hPa layer, so a significant precip maker is not expected.
Increased pops to high chance category given decent agreement between
global and mesoscale models. Largely followed the ARW for pop arrangement
with a slight bias towards the ECMWF as well. Have 1" snow accumulations
within a polygon from Syracuse to Dodge City to Dighton. This is mostly
in agreement with WPC. The ARW and HRRR show amounts over 2". Will not
issue a winter weather advisory since grid values are below criteria.
Not expecting a major impact as well in terms of hazardous travel conditions.
Also have undercut highs for today as plenty of cloud cover is expected.
Lows heading into Friday morning will be mainly in the teens as high
pressure builds in and the sky clears.
.LONG TERM...(Friday THROUGH Wednesday)
ISSUED AT 123 AM CST THU DEC 17 2015
A dry forecast is expected through the rest of the forecast domain.
There is still some chatter about a significant storm system by the
end of December. This is not an official NWS forecast and was only based
on one model solution (a poor performing model at that). FWIW, that
snow storm is not even shown anymore for SW Kansas on said model. Anyway,
pops will remain aob 14 percent. No significant precipitation is expected
to close out the extended. A frontal system will move through Sunday,
however, wind is mainly associated with this system. Any precip should
remain in eastern Kansas. Beyond this, a zonal flow pattern sets up.
This will favor near to above normal temperatures. Another dry system
might move across towards the holiday. Ahead of this system, might
end up fairly warm for xmas.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Thursday NIGHT)
ISSUED AT 1100 PM CST WED DEC 16 2015
An upper level disturbance will move across the region today. This
will lead to some light snow showers across the terminals. Some of the
models are very aggressive with a reduction of cigs associated with
said feature. Moisture upstream seems to be fairly limited. Will have
MVFR cigs in for now and tempo group with -sn. Flight conditions will
improve to VFR tonight. Winds NW/W 5-15 kt.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 15 41 25 / 50 20 0 0
GCK 31 14 46 23 / 50 20 0 0
EHA 31 14 46 26 / 30 10 0 0
LBL 32 15 43 24 / 40 10 0 0
HYS 31 16 43 22 / 20 20 0 0
P28 37 18 47 25 / 30 20 0 0
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Sugden
LONG TERM...Sugden
AVIATION...Sugden
AREA FORECAST DISCUSSION
NWS JACKSON KY
129 AM EST THU DEC 17 2015
.UPDATE...
ISSUED AT 129 AM EST THU DEC 17 2015
WSR-88D RADAR SHOWING SEVERAL BANDS OF SHOWERS TRAVERSING EASTERN
KY THIS HOUR. IT HAS TAKEN SOME TIME TO MOISTEN THE SURFACE GIVEN
DRY AIR IN PLACE TODAY. THAT SAID AREAS ACROSS THE FAR EAST ARE
STILL HAVING TROUBLE MOISTENING AND SOME OF THE RETURNS IN THOSE
SPOTS ARE STILL VIRGA. WHILE MOST PORTIONS OF THE REGION ARE
SEEING SHOWERS WITH BREAKS POSSIBLE HERE AND THERE. SOME OF THE
BETTER RETURNS THIS HOUR ARE RESIDING NEARER THE LAKE CUMBERLAND
REGION. MADE SOME MINOR ADJUSTMENTS TO POPS/SKY...AND THEN MADE
ADJUSTMENTS TO TEMP/DEW/WINDS TO LATEST OBS AND TRENDS. OTHERWISE
SHOULD BE IN GOOD SHAPE FORECAST WISE AT THIS JUNCTURE.
UPDATE ISSUED AT 1058 PM EST WED DEC 16 2015
FRESHENED UP THE HOURLY TEMPERATURES...DEW POINTS...AND POPS
ACCORDING TO THE LATEST TRENDS IN OBSERVATIONS. RAIN SHOWERS HAVE
EXPANDED IN AREAL COVERAGE AND CONTINUE TO ADVANCE TO THE
NORTHEAST. SOME EASTERN VALLEY TEMPERATURES ARE STILL IN THE
UPPER 40S...BUT THIS SHOULD CHANGE IN THE NEXT HOUR OR SO...AS
THE THICKER CLOUD COVER AND PRECIPITATION HELP TO MIX OUT THE
COOLER AIR. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 722 PM EST WED DEC 16 2015
ONLY LIGHT RETURNS HAVE MADE IT INTO OUR AREA THUS FAR THIS
EVENING...WITH THE LOW LEVEL DRY AIR IN PLACE ACROSS EASTERN
KENTUCKY KEEPING THE SHOWER ACTIVITY AT BAY. CLOUD THINNESS IN
THE EAST AND THE LOW DEW POINTS HAVE ALLOWED FOR A QUICK DROP IN
THE SHELTERED VALLEYS...WITH SOME UPPER 40 DEGREE READINGS
CURRENTLY BEING REPORTED. HAVE ADJUSTED THE TEMPERATURES
ACCORDINGLY...WITH A NICE REBOUND EXPECTED IN THE NEXT FEW HOURS
AS THICKER CLOUD COVER MOVES IN. THE LATEST HRRR LINES UP FAIRLY
WELL WITH THE CURRENT RADAR MOSAIC. THERE IS A NICE AREA OF
SHOWERS MOVING IN ACROSS WESTERN TENNESSEE...WHICH WILL BE MAKING
IT INTO OUR SOUTHWEST COUNTIES BETWEEN 9 AND 10 PM. HAVE ADJUSTED
THE POP TIMING A BIT TO CAPTURE THESE TRENDS. JUST BLENDED BACK
INTO THE EXISTING FORECAST THEREAFTER...WHICH REMAINS ON TRACK
FOR WIDESPREAD SHOWERS TO OVERTAKE THE REST OF EASTERN KENTUCKY
THROUGH THE OVERNIGHT HOURS. UPDATES WILL BE OUT SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 315 PM EST WED DEC 16 2015
AS OF MID AFTERNOON A MID LEVEL RIDGE EXTENDED FROM THE CARIBBEAN
NORTH AND NORTHWEST TOWARD THE JAMES BAY REGION WHILE ANOTHER
RIDGE WAS OVER PARTS OF THE EASTERN PACIFIC. IN BETWEEN...A RATHER
BROAD ENCOMPASSED MUCH OF THE ROCKIES AND CENTRAL AND NORTHERN
PLAINS. AN UPPER LEVEL LOW MOVING THROUGH THIS TROUGH IS LOCATED
OVER THE UPPER MS VALLEY WITH A TRAILING SHORTWAVE TROUGH INTO THE
MS VALLEY REGION WHILE ANOTHER SHORTWAVE TROUGH IS UPSTREAM OVER
THE SOUTHERN ROCKIES. YET ANOTHER SHORTWAVE OF NOTE IS DROPPING
THROUGH THE NORTHERN ROCKIES. AT THE SFC...AN AREA OF LOW PRESSURE
IS OVER THE UPPER MS VALLEY REGION WITH A WARM FRONT EXTENDING
INTO THE MID OH VALLEY REGION AND A COLD FRONT TRAILING SOUTH
THROUGH THE MS VALLEY. SHOWERS ARE CURRENTLY OCCURRING ALONG AND
IN ADVANCE OF THIS FRONT OVER WESTERN AND MIDDLE TN AND PARTS OF
CENTRAL KY AS WELL AS SOUTH INTO MS. IN ADVANCE OF THE COLD
FRONT...TEMPERATURES HAVE WARMED AND DRIER AIR HAS MIXED DOWN AT
BRIEFLY WITH TEMPERATURES HAVING REACHED THE 70 AT JKL...AND SOME
OF THE KY MESONET SITES ACROSS THE SOUTHEAST. THE RECORD HIGH HAS
ALREADY BEEN BROKEN AT JKL SO FAR THIS AFTERNOON.
THE TROUGH OVER THE PLAINS AND ROCKIES WILL MOVE INTO THE CENTRAL
AND EASTERN CONUS THROUGH THE PERIOD. THE INITIAL SHORTWAVE
TROUGH AXIS AND THE COLD FRONT WILL APPROACH THE AREA THIS EVENING
INTO THE OVERNIGHT HOURS AND AS THE NEXT UPSTREAM SHORTWAVE NOW OF
THE SOUTHERN ROCKIES MOVES INTO THE SOUTHERN PLAINS AND THE MS
VALLEY REGION...A WAVE OF LOW PRESSURE WILL DEVELOP ALONG THE
BOUNDARY AND MOVE ACROSS THE SOUTHEASTERN STATES. AS THIS
OCCURS...COVERAGE OF SHOWERS SHOULD INCREASE SIGNIFICANTLY AND
WITH THIS TRACKING TO THE SOUTHEAST OF THE AREA...THE HEAVIEST
RAINFALL SHOULD OCCUR CLOSER TO THE VA AND TN BORDERS. GIVEN THE
CURRENT LOWER DEW POINTS ACROSS THAT REGION...HAVE OPTED TO CUT
BACK ON OVERNIGHT QPF ACROSS THE FAR SOUTHEAST PART OF THE AREA.
THE SECOND SHORTWAVE TROUGH AXIS SHOULD CROSS THE AREA ON THU
AFTERNOON WHILE THE SHORTWAVE THAT IS NOW OVER THE NORTHERN
ROCKIES WILL DROP INTO THE CENTRAL PLAINS AND THEN INTO THE MS
VALLEY AND OH VALLEY LATE IN THE PERIOD. BEHIND THE COLD
FRONT...COLD AIR ADVECTION IS ANTICIPATED FOR THU INTO THU NIGHT
AND HAVE OPTED TO GO CLOSER TO A BLEND OF SUPERBLEND AND MOS
GUIDANCE RATHER THAN A CLIMATOLOGICALLY BASED TEMPERATURE CURVE.
LAPSE RATES MAY STEEPEN SUFFICIENTLY ENOUGH FOR SOME FLURRIES BY
LATE IN THE PERIOD...AND TEMPERATURES SHOULD REACH OR FALL BELOW
FREEZING IN WIDESPREAD FASHION ON THU NIGHT FOR THE FIRST TIME IN
ABOUT A WEEK. THE HEART OF THIS COLD AIRMASS THOUGH WILL HOLD OFF
UNTIL THE LONG TERM PERIOD.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 310 PM EST WED DEC 16 2015
AFTER A SFC COLD FRONT DEPARTS THE REGION LATE THURSDAY...AN
UPPER LEVEL TROUGH SHIFTS INTO THE AREA. POTENT ENERGY WILL BE
SWINGING THROUGH THE BASE OF THE TROUGH ON FRIDAY. THIS COULD
RESULT IN SOME LIGHT SNOW SHOWERS...ESPECIALLY IN THE EASTERN HIGH
TERRAIN. THE BEST CHANCE FOR SNOW SHOWERS WILL BE IN THE AFTERNOON AS
THE BEST UPPER LEVEL ENERGY PASSES THROUGH EASTERN KENTUCKY. EVEN
THOUGH THE COLD TEMPERATURES AND UPPER LEVEL ENERGY ARE
PRESENT...THE MOISTURE IS LACKING. SO DO NOT EXPECT SNOW
ACCUMULATIONS EXCEPT FOR MAYBE A LIGHT COATING OR DUSTING ON
ROOFTOPS/GRASSY AREAS AND IN THE EASTERN HIGH TERRAIN. ROADS
SHOULD STAY WARM ENOUGH TO MELT ANY SNOW THAT DOES FALL ON FRIDAY.
THE SNOW SHOWERS WILL TAPER OFF TO FLURRIES FRIDAY EVENING.
AS THE TROUGH MOVES EAST AND SFC HIGH PRESSURE BUILDS IN FROM THE
WEST...CLOUDS WILL DECREASE ON SATURDAY...BUT A VERY CHILLY AIR
MASS WILL BE IN PLACE. DEPENDENT ON THE CLOUD COVER...TEMPS WILL
GENERALLY FALL INTO THE LOW AND MID 20S FRIDAY NIGHT. THE SFC HIGH
WILL SHIFT SLIGHTLY TO OUR EAST SATURDAY NIGHT WITH WARMER AIR
BEGINNING TO WORK ITS WAY BACK INTO THE REGION. HOWEVER...SATURDAY
NIGHT WILL LIKELY BE THE COLDEST NIGHT WE HAVE SEEN IN AWHILE WITH
CLEAR SKIES AND LIGHT WINDS. THIS SET UP WILL ALLOW TEMPS IN THE
VALLEY LOCATIONS TO FALL INTO THE TEENS...AND RIDGE TEMPS TO DIP
INTO THE LOWER/MID 20S. FORTUNATELY...A SIGNIFICANT WARM UP WILL
OCCUR BEGINNING SUNDAY ALLOWING TEMPERATURES TO REBOUND INTO THE
50S...AND 60S BY MID WEEK.
A MORE ACTIVE WEATHER PATTERN WILL BE IN PLACE NEXT WEEK AS A
SERIES OF IMPULSES WORK THROUGH THE AREA. THE NEXT CHANCE OF RAIN
COMES ON MONDAY AS WE SEE AN INCREASE IN GULF MOISTURE AHEAD OF A
COLD FRONTAL SYSTEM. THE COLD FRONT IS EXPECTED TO STALL NEAR OUR
AREA...AND WITH A MOIST FLOW OFF THE GULF...RAIN CHANCES WILL ALSO
PERSIST THROUGH THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1242 AM EST THU DEC 17 2015
TIME HEIGHTS SHOWING THAT DRIER AIR AT THE SURFACE IS ATTEMPTING
TO STICK IN...HOWEVER WE WILL MOISTEN AS WE MOVE THROUGH THE
OVERNIGHT HOURS. THAT SAID MOST SITES ARE SEEING SOME SHOWERS TO
START THE TAF PERIOD...HOWEVER MUCH OF THIS HAS BEEN HIGH BASED
ACTIVITY. SYM IS SEEING A GUSTIER SHOWER TO BEGIN THE PERIOD WITH
A BRIEF GUST TO 15 TO 20 POSSIBLE...AS THEY ARE ABLE TO MIX DOWN
SOME OF THE LOW LEVEL JET. THIS IS ALSO LEADING TO A MVFR START
FOR THEM IN TERMS OF VIS. OTHERWISE AS WE MOISTEN CIGS WILL LOWER
WITH IFR LOOKING LIKELY TOWARD DAWN AT ALL TAF SITES. BY THIS
AFTERNOON WE ARE EXPECTED TO SEE IMPROVING CONDITIONS AS FRONT
MOVES EAST OF THE REGION. WINDS SHOULD REMAIN MOSTLY LIGHT THROUGH
THE PERIOD STARTING OFF MORE SOUTH TO SOUTHWEST AND SHIFTING TO
MORE OF A NW COMPONENT AFTER FRONTAL PASSAGE AS MENTIONED IN LAST
TAF UPDATE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...JP
LONG TERM...JVM
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
1242 AM EST THU DEC 17 2015
.UPDATE...
ISSUED AT 1058 PM EST WED DEC 16 2015
FRESHENED UP THE HOURLY TEMPERATURES...DEW POINTS...AND POPS
ACCORDING TO THE LATEST TRENDS IN OBSERVATIONS. RAIN SHOWERS HAVE
EXPANDED IN AREAL COVERAGE AND CONTINUE TO ADVANCE TO THE
NORTHEAST. SOME EASTERN VALLEY TEMPERATURES ARE STILL IN THE
UPPER 40S...BUT THIS SHOULD CHANGE IN THE NEXT HOUR OR SO...AS
THE THICKER CLOUD COVER AND PRECIPITATION HELP TO MIX OUT THE
COOLER AIR. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 722 PM EST WED DEC 16 2015
ONLY LIGHT RETURNS HAVE MADE IT INTO OUR AREA THUS FAR THIS
EVENING...WITH THE LOW LEVEL DRY AIR IN PLACE ACROSS EASTERN
KENTUCKY KEEPING THE SHOWER ACTIVITY AT BAY. CLOUD THINNESS IN
THE EAST AND THE LOW DEW POINTS HAVE ALLOWED FOR A QUICK DROP IN
THE SHELTERED VALLEYS...WITH SOME UPPER 40 DEGREE READINGS
CURRENTLY BEING REPORTED. HAVE ADJUSTED THE TEMPERATURES
ACCORDINGLY...WITH A NICE REBOUND EXPECTED IN THE NEXT FEW HOURS
AS THICKER CLOUD COVER MOVES IN. THE LATEST HRRR LINES UP FAIRLY
WELL WITH THE CURRENT RADAR MOSAIC. THERE IS A NICE AREA OF
SHOWERS MOVING IN ACROSS WESTERN TENNESSEE...WHICH WILL BE MAKING
IT INTO OUR SOUTHWEST COUNTIES BETWEEN 9 AND 10 PM. HAVE ADJUSTED
THE POP TIMING A BIT TO CAPTURE THESE TRENDS. JUST BLENDED BACK
INTO THE EXISTING FORECAST THEREAFTER...WHICH REMAINS ON TRACK
FOR WIDESPREAD SHOWERS TO OVERTAKE THE REST OF EASTERN KENTUCKY
THROUGH THE OVERNIGHT HOURS. UPDATES WILL BE OUT SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 315 PM EST WED DEC 16 2015
AS OF MID AFTERNOON A MID LEVEL RIDGE EXTENDED FROM THE CARIBBEAN
NORTH AND NORTHWEST TOWARD THE JAMES BAY REGION WHILE ANOTHER
RIDGE WAS OVER PARTS OF THE EASTERN PACIFIC. IN BETWEEN...A RATHER
BROAD ENCOMPASSED MUCH OF THE ROCKIES AND CENTRAL AND NORTHERN
PLAINS. AN UPPER LEVEL LOW MOVING THROUGH THIS TROUGH IS LOCATED
OVER THE UPPER MS VALLEY WITH A TRAILING SHORTWAVE TROUGH INTO THE
MS VALLEY REGION WHILE ANOTHER SHORTWAVE TROUGH IS UPSTREAM OVER
THE SOUTHERN ROCKIES. YET ANOTHER SHORTWAVE OF NOTE IS DROPPING
THROUGH THE NORTHERN ROCKIES. AT THE SFC...AN AREA OF LOW PRESSURE
IS OVER THE UPPER MS VALLEY REGION WITH A WARM FRONT EXTENDING
INTO THE MID OH VALLEY REGION AND A COLD FRONT TRAILING SOUTH
THROUGH THE MS VALLEY. SHOWERS ARE CURRENTLY OCCURRING ALONG AND
IN ADVANCE OF THIS FRONT OVER WESTERN AND MIDDLE TN AND PARTS OF
CENTRAL KY AS WELL AS SOUTH INTO MS. IN ADVANCE OF THE COLD
FRONT...TEMPERATURES HAVE WARMED AND DRIER AIR HAS MIXED DOWN AT
BRIEFLY WITH TEMPERATURES HAVING REACHED THE 70 AT JKL...AND SOME
OF THE KY MESONET SITES ACROSS THE SOUTHEAST. THE RECORD HIGH HAS
ALREADY BEEN BROKEN AT JKL SO FAR THIS AFTERNOON.
THE TROUGH OVER THE PLAINS AND ROCKIES WILL MOVE INTO THE CENTRAL
AND EASTERN CONUS THROUGH THE PERIOD. THE INITIAL SHORTWAVE
TROUGH AXIS AND THE COLD FRONT WILL APPROACH THE AREA THIS EVENING
INTO THE OVERNIGHT HOURS AND AS THE NEXT UPSTREAM SHORTWAVE NOW OF
THE SOUTHERN ROCKIES MOVES INTO THE SOUTHERN PLAINS AND THE MS
VALLEY REGION...A WAVE OF LOW PRESSURE WILL DEVELOP ALONG THE
BOUNDARY AND MOVE ACROSS THE SOUTHEASTERN STATES. AS THIS
OCCURS...COVERAGE OF SHOWERS SHOULD INCREASE SIGNIFICANTLY AND
WITH THIS TRACKING TO THE SOUTHEAST OF THE AREA...THE HEAVIEST
RAINFALL SHOULD OCCUR CLOSER TO THE VA AND TN BORDERS. GIVEN THE
CURRENT LOWER DEW POINTS ACROSS THAT REGION...HAVE OPTED TO CUT
BACK ON OVERNIGHT QPF ACROSS THE FAR SOUTHEAST PART OF THE AREA.
THE SECOND SHORTWAVE TROUGH AXIS SHOULD CROSS THE AREA ON THU
AFTERNOON WHILE THE SHORTWAVE THAT IS NOW OVER THE NORTHERN
ROCKIES WILL DROP INTO THE CENTRAL PLAINS AND THEN INTO THE MS
VALLEY AND OH VALLEY LATE IN THE PERIOD. BEHIND THE COLD
FRONT...COLD AIR ADVECTION IS ANTICIPATED FOR THU INTO THU NIGHT
AND HAVE OPTED TO GO CLOSER TO A BLEND OF SUPERBLEND AND MOS
GUIDANCE RATHER THAN A CLIMATOLOGICALLY BASED TEMPERATURE CURVE.
LAPSE RATES MAY STEEPEN SUFFICIENTLY ENOUGH FOR SOME FLURRIES BY
LATE IN THE PERIOD...AND TEMPERATURES SHOULD REACH OR FALL BELOW
FREEZING IN WIDESPREAD FASHION ON THU NIGHT FOR THE FIRST TIME IN
ABOUT A WEEK. THE HEART OF THIS COLD AIRMASS THOUGH WILL HOLD OFF
UNTIL THE LONG TERM PERIOD.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 310 PM EST WED DEC 16 2015
AFTER A SFC COLD FRONT DEPARTS THE REGION LATE THURSDAY...AN
UPPER LEVEL TROUGH SHIFTS INTO THE AREA. POTENT ENERGY WILL BE
SWINGING THROUGH THE BASE OF THE TROUGH ON FRIDAY. THIS COULD
RESULT IN SOME LIGHT SNOW SHOWERS...ESPECIALLY IN THE EASTERN HIGH
TERRAIN. THE BEST CHANCE FOR SNOW SHOWERS WILL BE IN THE AFTERNOON AS
THE BEST UPPER LEVEL ENERGY PASSES THROUGH EASTERN KENTUCKY. EVEN
THOUGH THE COLD TEMPERATURES AND UPPER LEVEL ENERGY ARE
PRESENT...THE MOISTURE IS LACKING. SO DO NOT EXPECT SNOW
ACCUMULATIONS EXCEPT FOR MAYBE A LIGHT COATING OR DUSTING ON
ROOFTOPS/GRASSY AREAS AND IN THE EASTERN HIGH TERRAIN. ROADS
SHOULD STAY WARM ENOUGH TO MELT ANY SNOW THAT DOES FALL ON FRIDAY.
THE SNOW SHOWERS WILL TAPER OFF TO FLURRIES FRIDAY EVENING.
AS THE TROUGH MOVES EAST AND SFC HIGH PRESSURE BUILDS IN FROM THE
WEST...CLOUDS WILL DECREASE ON SATURDAY...BUT A VERY CHILLY AIR
MASS WILL BE IN PLACE. DEPENDENT ON THE CLOUD COVER...TEMPS WILL
GENERALLY FALL INTO THE LOW AND MID 20S FRIDAY NIGHT. THE SFC HIGH
WILL SHIFT SLIGHTLY TO OUR EAST SATURDAY NIGHT WITH WARMER AIR
BEGINNING TO WORK ITS WAY BACK INTO THE REGION. HOWEVER...SATURDAY
NIGHT WILL LIKELY BE THE COLDEST NIGHT WE HAVE SEEN IN AWHILE WITH
CLEAR SKIES AND LIGHT WINDS. THIS SET UP WILL ALLOW TEMPS IN THE
VALLEY LOCATIONS TO FALL INTO THE TEENS...AND RIDGE TEMPS TO DIP
INTO THE LOWER/MID 20S. FORTUNATELY...A SIGNIFICANT WARM UP WILL
OCCUR BEGINNING SUNDAY ALLOWING TEMPERATURES TO REBOUND INTO THE
50S...AND 60S BY MID WEEK.
A MORE ACTIVE WEATHER PATTERN WILL BE IN PLACE NEXT WEEK AS A
SERIES OF IMPULSES WORK THROUGH THE AREA. THE NEXT CHANCE OF RAIN
COMES ON MONDAY AS WE SEE AN INCREASE IN GULF MOISTURE AHEAD OF A
COLD FRONTAL SYSTEM. THE COLD FRONT IS EXPECTED TO STALL NEAR OUR
AREA...AND WITH A MOIST FLOW OFF THE GULF...RAIN CHANCES WILL ALSO
PERSIST THROUGH THE END OF THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1242 AM EST THU DEC 17 2015
TIME HEIGHTS SHOWING THAT DRIER AIR AT THE SURFACE IS ATTEMPTING
TO STICK IN...HOWEVER WE WILL MOISTEN AS WE MOVE THROUGH THE
OVERNIGHT HOURS. THAT SAID MOST SITES ARE SEEING SOME SHOWERS TO
START THE TAF PERIOD...HOWEVER MUCH OF THIS HAS BEEN HIGH BASED
ACTIVITY. SYM IS SEEING A GUSTIER SHOWER TO BEGIN THE PERIOD WITH
A BRIEF GUST TO 15 TO 20 POSSIBLE...AS THEY ARE ABLE TO MIX DOWN
SOME OF THE LOW LEVEL JET. THIS IS ALSO LEADING TO A MVFR START
FOR THEM IN TERMS OF VIS. OTHERWISE AS WE MOISTEN CIGS WILL LOWER
WITH IFR LOOKING LIKELY TOWARD DAWN AT ALL TAF SITES. BY THIS
AFTERNOON WE ARE EXPECTED TO SEE IMPROVING CONDITIONS AS FRONT
MOVES EAST OF THE REGION. WINDS SHOULD REMAIN MOSTLY LIGHT THROUGH
THE PERIOD STARTING OFF MORE SOUTH TO SOUTHWEST AND SHIFTING TO
MORE OF A NW COMPONENT AFTER FRONTAL PASSAGE AS MENTIONED IN LAST
TAF UPDATE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...JP
LONG TERM...JVM
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1240 AM EST THU DEC 17 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION WILL MOVE EAST LATE TONIGHT.
INTENSE LOW PRESSURE WILL MOVE NORTH OF THE GREAT LAKES INTO
WESTERN QUEBEC PROVINCE THURSDAY...WHILE A WEAK SECONDARY LOW
FROM THE SOUTHWEST MOVES NORTHEAST ALONG THE MAINE COAST THURSDAY
NIGHT AND EARLY FRIDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1230 AM UPDATE...PER COORDINATION CALL W/GYX, DECIDED TO GO W/THE
FREEZING RAIN ADVISORY FOR THE CENTRAL AND DOWNEAST AREAS
INCLUDING THE COAST THROUGH 9 AM. SOME SITES ACROSS GYX`S CWA
REPORTING -SN SUCH AS KIWI. MRMS AND REGIONAL RADAR INDICATED
LIGHT RETURNS EDGING N ATTM AND THE LATEST HI RES ARW AND HRRR 3KM
MODEL MATCHING UP WELL W/THE CURRENT CONDITIONS. THEIR TREND IS
BRING PRECIP N INTO THE DOWNEAST AND COASTAL AREAS W/IN THE NEXT
FEW HRS. SOUNDINGS INDICATE VERY LIGHT SNOW OR EVEN LIGHT FREEZING
DRIZZLE. DECIDED TO CARRY FREEZING DRIZZLE INTO CENTRAL AND
DOWNEAST AREAS THROUGH THE MORNING. TEMPS ARE BELOW FREEZING ALL
THE WAY TO THE COAST AND COULD ACTUALLY DROP A BIT WHEN LIGHT
PRECIP STARTS BEFORE WARMING LATER ON. ROAD SURFACES ARE WELL
BELOW FREEZING. THEREFORE, ANY LIQUID PRECIP WILL FREEZE ON
CONTACT. THE FREEZING RAIN ADVISORY ACROSS THE NORTHERN CWA
REMAINS IN PLACE.
PREVIOUS DISCUSSION...
ATTN SHIFTS TO LLVL MOISTURE ADVCNG INTO THE FA FROM THE SW BY
THU MORN. WITH TEMPS ONLY XPCTD TO SLOWLY RISE AFTN ARND MDNGT
LOWS...THE POTENTIAL EXISTS FOR A PD OF LGT SLEET AND FZG RN OVR
THE N WHERE WE ISSUED A FZG RN ADV...SPCLY LATE MORNING INTO THE
AFTN...WITH LONGEST POTENTIAL OR THE XTRM N. ANOTHER CONCERN IS
THE POSSIBILITY OF PATCHY LGT FZG DZ S OF THE ADV AREA BY ERLY THU
MORN INLAND OF THE IMMEDIATE COAST. SINCE WE ARE UNCERTAIN OF CVRG
OF FZG PRECIP AND WHETHER THERE WILL BE ENOUGH FOR MEASURABLE
PRECIP...WE HELD OFF ON ISSUING A AN ADV ATTM...SINCE AN SPS MIGHT
SUFFICE...BUT WE CANNOT RULE OUT AN XTNSN OF THE CURRENT FZG RN
ADV SWRD TO JUST N OF THE IMMEDIATE COAST WITH LATER FCST UPDATES.
TEMPS WILL BE SLOWEST TO RISE ABV FZG ACROSS THE N WHERE LGT FZRA
WILL BE LAST TO CHG TO ALL RN LATE IN THE AFTN. FOR TEMPS ON
THU...WE USED A BLEND OF RAW MODEL TEMPS SHOWING A HI TEMP AT THE
END OF THE DAY. WE ALSO USED THE WX FROM THICKNESS TOOL TO CREATE
THE PRECIP TYPES ON THU...TAKING A 65/35 GFS/ECMWF BLEND. MAX ICE
ACCUM LOOKS TO BE MSLY BLO A TENTH OF AN INCH IN THE ADV AREA WITH
MANY LCTNS JUST GETTING A TRACE.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
AN OCCLUDED FRONT WILL CROSS THE REGION THURSDAY NIGHT WHILE LOW
PRESSURE DEVELOPS ALONG THE FRONT ACROSS THE GULF OF MAINE.
GENERALLY EXPECT RAIN ACROSS THE REGION IN ADVANCE OF THE FRONT
THURSDAY NIGHT ALONG WITH AREAS OF FOG...THEN TAPERING TO SHOWERS
IN THE WAKE OF THE FRONT. GENERALLY EXPECT PRECIPITATION TO REMAIN
IN THE FORM OF RAIN THURSDAY NIGHT...THOUGH SNOW COULD MIX WITH
THE RAIN SHOWERS ACROSS NORTHERN AREAS LATE. A FRONTAL BOUNDARY
WILL REMAIN ACROSS THE GULF OF MAINE FRIDAY WHILE THE LOW EXITS
ACROSS THE MARITIMES. SKIES WILL REMAIN MOSTLY CLOUDY ACROSS THE
REGION FRIDAY WITH A SLIGHT CHANCE OF MOSTLY AFTERNOON RAIN
SHOWERS. MODELS INDICATE THAT A FAST MOVING LOW COULD FORM ALONG
THE FRONT EARLY FRIDAY NIGHT THEN EXIT ACROSS THE MARITIMES
OVERNIGHT. HOWEVER...THE TRACK OF THE LOW IS STILL UNCERTAIN. A
TRACK ACROSS THE GULF OF MAINE COULD ALLOW ENOUGH COLD AIR TO WRAP
AROUND THE STORM TO PRODUCE LIGHT SNOW ACCUMULATIONS ACROSS
DOWNEAST AREAS EARLY FRIDAY NIGHT. A MORE EASTERLY TRACK WOULD
LIMIT PRECIPITATION AND SNOW POTENTIAL. THE LOW WILL EXIT ACROSS
THE MARITIMES OVERNIGHT DRAWING COLDER AIR ACROSS THE REGION.
EXPECT MOSTLY CLOUDY SKIES ALONG WITH A CHANCE OF SNOW SHOWERS
ACROSS THE NORTH AND MOUNTAINS SATURDAY...WITH LOCALLY HEAVIER
SNOW SHOWERS POSSIBLE. EXPECT PARTLY CLOUDY SKIES ALONG WITH
LESSER SNOW SHOWER CHANCES DOWNEAST SATURDAY. TEMPERATURES WILL
BE AT ABOVE NORMAL LEVELS FRIDAY...WITH SLIGHTLY ABOVE NORMAL
LEVEL TEMPERATURES SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
A GENERALLY MILD WEATHER PATTERN WILL CONTINUE THROUGH NEXT WEEK
ALTHOUGH THE WEEKEND WILL END A BIT COOL. SATURDAY NIGHT AND SUNDAY
WILL BE BREEZY AND DRY WITH INCREASING CLOUDS SUNDAY AS A LARGE AREA
OF HIGH PRESSURE MOVES OFF THE EAST COAST AND A BAND OF WARM
ADVECTION CLOUDS LIFTS ACROSS THE AREA. LOW PRESSURE LIFTING THROUGH
THE GREAT LAKES COMBINED WITH HIGH PRESSURE MOVING OFF THE EAST
COAST WILL THEN BRING A MILDER SOUTHWESTERLY FLOW OF AIR INTO THE
REGION ON MONDAY. SOME RAIN SHOWERS, POSSIBLY MIXED WITH SOME WET
SNOW OVER THE FAR NORTH, WILL COME THROUGH LATE MONDAY INTO MONDAY
NIGHT AS THE LOW LIFTS INTO QUEBEC. COOLER AIR WILL FOLLOW ON GUSTY
NORTHWESTERLY WINDS MONDAY NIGHT INTO TUESDAY FOLLOWED BY MORE
TRANQUIL CONDITIONS TUESDAY NIGHT AS HIGH PRESSURE BUILDS OVER. LOW
PRESSURE WILL APPROACH WEDNESDAY WITH INCREASING CLOUDS. SOME SNOW
OR MIXED PRECIPITATION WEDNESDAY NIGHT WILL THEN LIKELY CHANGE TO
RAIN ON THURSDAY AS STRONG RIDGING ALONG THE EAST COAST COMBINED
WITH A LOW TO OUR WEST ONCE AGAIN PULLS WARMER AIR NORTH INTO THE
REGION.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
NEAR TERM: 1230 AM UPDATE: WILL MONITOR KBGR FOR POSSIBLE AWW DUE
TO FREEZING DRIZZLE AND VERY LIGHT SNOW WHICH COULD LEAD TO SOME
LIGHT ICING.
MVFR CONDITIONS CONTINUE TO PERSIST TONIGHT WITH
POCKETS OF IFR ACROSS FAR NORTHERN MAINE AS STRATUS REMAINS
TRAPPED UNDER A STRONG INVERSION. ADDITIONAL LOW CEILINGS ARE
LIKELY ADVCG FROM THE S LATE TNGT AS OCEAN ST ENCOMPASSES THE
REGION WITH DEEP LAYER RETURN SRLY FLOW. CLGS SHOULD LOWER TO IFR
BY THU MORN OVR THE S HLF OF THE FA AND BY AFTN ACROSS THE N.
SHORT TERM: IFR/LIFR CONDITIONS ARE EXPECTED ACROSS THE REGION
THURSDAY NIGHT. OCCASIONAL MVFR CONDITIONS ARE THEN POSSIBLE
FRIDAY THROUGH SATURDAY. GENERALLY EXPECT VFR CONDITIONS SUNDAY.
OCCASIONAL MVFR CONDITIONS ARE POSSIBLE MONDAY.
&&
.MARINE...
NEAR TERM: 1230 AM UPDATE: ADDED AREAS OF FOG AS VSBYS FROM THE
OBS ARE BELOW 1 NM.
THE WIND AND SEAS WILL REMAIN BELOW SCA LEVELS OVERNIGHT AND
THU MORNING...THEN THE WIND WILL INCREASE THE THE SEAS WILL SLOWLY
BUILD LATE THU AFTN WITH INCREASING SRLY WINDS TO NEAR SCA LVLS
LATE IN THE AFTN. GIVEN THAT SCA CONDITIONS WILL NOT LIKELY ONSET
UNTIL ERLY THU EVE (PD 3)...WE WILL HOLD OFF ON ISSUING AN SCA
UNTIL LIKELY THE ERLY MORN FCST UPDATE.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED ACROSS
THE WATERS THURSDAY NIGHT THROUGH FRIDAY NIGHT. GALE CONDITIONS
ARE THEN POSSIBLE SATURDAY. VISIBILITIES WILL BE REDUCED IN RAIN
AND FOG THURSDAY NIGHT...WITH RAIN AGAIN FRIDAY NIGHT.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...FREEZING RAIN ADVISORY FROM 8 AM THIS MORNING TO 6 PM EST THIS
EVENING FOR MEZ001>006.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR MEZ011-
015>017-029>032.
FREEZING RAIN ADVISORY UNTIL 6 PM EST THIS EVENING FOR MEZ010.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1156 PM EST WED DEC 16 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 357 PM EST WED DEC 16 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE PLAINS INTO THE WRN LAKES. A VIGOROUS SHORTWAVE LIFTING
THROUGH NW WI SUPPORTED A BAND OF SHOWERS NEAR THE WI BORDER INTO
ERN WI. INSTABILITY ASSOCIATED WITH THIS FEATURE WAS GREAT ENOUGH TO
SUPPORT SOME ISOLD TSRA. AT THE SFC...A 991 MB LOW OVER FAR NW WI
WITH AN OCCLUDED FRONT INTO CNTRL WI WAS LIFTING TO THE NORTHEAST.
TEMPS REMAINED IN THE MID 30S WITH MAINLY LIGHT RAIN BEHIND THE
FRONT OVER WRN WI. COLDER AIR WITH PCPN CHANGING TO SNOW HAD MOVED
TO NEAR KMSP.
TONIGHT...EXPECT THE SCT SHOWERS TO LIFT INTO UPPER MI LATE THIS
AFTERNOON. A RUMBLE OF THUNDER MAY ALSO BE POSSIBLE OVER THE WEST.
AS THE LOW LIFTS TO THE NE...ENOUGH COLDER AIR WILL SWEEP IN FROM
THE SW TO CHANGE THE PCPN OVER TO SNOW THIS EVENING. OTHERWISE...WITH
ONLY WEAK UPWARD MOTION WITH THE WRAP-AROUND MOISTURE MOVING
IN...ONLY CHANCE POPS WERE MENTIONED OVER THE WEST. AS WINDS VEER
FROM THE SW TO WSW AFT 06Z AND 850 MB TEMPS DROP TO NEAR -10C...LOW
LEVEL CONV WILL BE MORE FAVORABLE FOR LES OR LAKE ENHANCED SNOW INTO
THE W AND N PORTIONS OF THE KEWEENAW PENINSUSLA WHERE SNOWFALL
AMOUNTS AROUND AN INCH ARE POSSIBLE.
THURSDAY...CONDITIONS WILL GRADUALLY BECOME MORE FAVORABLE FOR LES
ACROSS THE KEWEENAW AS 850 MB TEMPS DROP TO AROUND -12C WITH THE
CONVECTIVE CLOUD LAYER IN THE DGZ. WHILE THERE IS STILL SOME
UNCERTAINTY ON WHERE THE STRONGEST LOW LEVEL CONV WILL
DEVELOP...EXPECT INCREASING LES COULD BRING 1 TO 3 INCHES. TO MAINLY
THE NRN KEWEENAW. OTHWERWISE...TEMPS WILL DROP BACK CLOSER TO NORMAL
WITH HIGHS FROM THE MID 20S WEST TO THE LOW 30S EAST.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 506 PM EST WED DEC 16 2015
IT/S A RETURN TO WINTER...WELL AT LEAST FOR THE KEWEENAW. A LAKE
EFFECT SNOW WATCH REMAINS IN EFFECT FOR THE KEWEENAW PENINSULA
THURSDAY NIGHT THROUGH FRIDAY EVENING...AS WE HAVE PROLONGED W-NW
WINDS AND PLENTY OF MOISTURE STUCK IN THE DGZ...AND 850MB TEMPS OF -
13 TO -17C. TAKING A LOOK AT THE OVERALL PATTERN...A 500MB LOW
SPINNING ACROSS MANITOBA AND THE W HALF OF ONTARIO AT 00Z FRIDAY
WILL HAVE A TROUGH EXTENDED ALL THE WAY THROUGH TX. EXPECT THIS LOW
TO SHIFT OVER JAMES BAY FRIDAY AFTERNOON AS THE TROUGH PUSHES ACROSS
THE GREAT LAKES STATES. LOOK FOR RIDGING TO BEGIN ALOFT ON SATURDAY
AS THE LOW EXITS ACROSS QUEBEC. A PROLONGED RIDGE WILL THEN STAY
ACROSS THE UPPER GREAT LAKES THROUGH SUNDAY.
WEAKER FEATURES WILL PUSH IN FOR THE START OF THE WORK WEEK...WITH A
BROAD BUT MAINLY FLAT TROUGH SET UP ACROSS MUCH OF THE NATION. THE
TROUGH WILL DEEPEN MONDAY NIGHT THROUGH WEDNESDAY...WITH SW FLOW
OVER OUR AREA.
AS FOR THE SFC FEATURES...THE SFC LOW OVER NE MN WILL BE OVER JAMES
BAY AT 00Z FRIDAY AND WILL STAY NEARLY IN PLACE THROUGH SATURDAY.
THIS WILL BE WHEN A SECONDARY LOW RIDING UP THE COLD FRONT OVER THE
ATLANTIC COAST DEEPENS OVER NE CANADA. MOISTURE QUICKLY DIMINISHES
AND INVERSION HEIGHTS LOWER DURING THE DAY SATURDAY AS A RIDGE
TEMPORARILY BUILDS IN. THE NEXT LOW OVER THE CENTRAL PLAINS SUNDAY
MORNING HAS SOME TIMING ISSUES TO RESOLVE...BUT LOOKS TO MOVE ACROSS
THE UPPER GREAT LAKES SOMETIME BETWEEN SUNDAY NIGHT AND MONDAY
EVENING. KEPT POPS IN THE CHANCE RANGE FOR NOW...WITH MAINLY SNOW
EXPECTED EXCEPT NEAR LAKE MI WHERE RAIN MAY MIX IN FROM TIME TO
TIME. THIS OF COURSE WILL GREATLY DEPEND ON THE TRACK. LOOK FOR A
RETURN OF ABOVE NORMAL TEMPERATURES FOR SUNDAY AFTERNOON THROUGH MID
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1156 PM EST WED DEC 16 2015
INCREASINGLY COLDER AIR FLOWING INTO THE UPPER LAKES BEHIND
DEPARTING LOW PRES WILL RESULT IN INCREASING LAKE EFFECT SNOW
SHOWERS DURING THIS FCST PERIOD. UNDER WESTERLY WINDS...KCMX WILL BE
THE ONLY TERMINAL AFFECTED BY THE SNOW. AT KCMX...MVFR CONDITIONS
WILL BE THE RULE INTO THE MORNING HRS WITH WINDS BECOMING GUSTY TO
AOA 30KT AFTER THE PASSAGE OF A SFC TROF AROUND 07Z. CONDITIONS WILL
DETERIORATE TO IFR IN THE AFTN WITH THE POTENTIAL FOR LIFR LATE AFTN
AND EVENING. AT KIWD...MVFR CONDITIONS WILL GENERALLY PREVAIL THRU
THE FCST PERIOD WITH THE EXCEPTION OF A POSSIBLE PERIOD OF IFR
OVERNIGHT FOLLOWING SFC TROF PASSAGE. EXPECTED WIND DIRECTION SHOULD
KEEP THE INCREASING LAKE EFFECT SNOW SHOWERS JUST N OF KIWD THRU
THIS FCST PERIOD. AT KSAW...MVFR CONDITIONS WILL BE THE RULE
OVERNIGHT. DOWNSLOPE COMPONENT TO THE WIND TODAY THRU THIS EVENING
SHOULD RESULT IN VFR BECOMING THE PREVAILING CONDITION.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 357 PM EST WED DEC 16 2015
WINDS WILL QUICKLY SHIFT TO THE SOUTHWEST THIS EVENING AS LOW
PRESSURE OVER NW WI LIFTS TO THE NORTHEAST OF THE AREA. EXPECT
ANOTHER PERIOD OF GALES TO 35KTS OVER AT LEAST THE SOUTHWESTERN HALF
OF LAKE SUPERIOR TONIGHT INTO THURSDAY MORNING. AS THE LOW BECOMES
NEARLY STATIONARY OVER SOUTHERN HUDSON BAY...EXPECT WESTERLY WINDS
OF 25-35KTS TO PERSIST THURSDAY AFTERNOON INTO FRIDAY BEFORE
DIMINISHING DUE TO AN APPROACHING RIDGE. THIS RIDGE WILL QUICKLY
MOVE ACROSS THE UPPER GREAT LAKES REGION ON SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM THURSDAY EVENING THROUGH LATE FRIDAY
NIGHT FOR MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 1 AM EST /MIDNIGHT CST/ FRIDAY FOR LSZ162-
240>245-263>266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
302 AM CST THU DEC 17 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 302 AM CST Thu Dec 17 2015
In spite of surface low working its way into southern Canada, low
level flow over our region has taken on much more of a northwest
component than indicated by yesterday`s model runs. This, in turn,
has allowed cold air SC in the wake of the low to advect much
further s, with the leading edge of the clouds near the I-70
corridor at 08z.
RUC 900MB RH prog seems to have a fairly good handle on current
cloud trends, and based on its forecast it appears that the low
clouds will continue to drop into southern sections of our CWA
during the day, although I do expect some slowing of the southward
progression as sunshine works on the leading edge of the cloud deck.
Have leaned heavily towards the cooler MET guidance for max temps,
as GFS MOS is oblivious to ongoing low cloudiness.
Truett
.LONG TERM: (Tonight through Wednesday)
Issued at 302 AM CST Thu Dec 17 2015
Not many changes from the prev forecast. With no measurable precip
expected, focus will be temps.
Given the pattern and verification lately, warm seems to be the way
to go and have continued a trend twd the warmer guidance. However,
did not go as warm as the warmest guidance for Fri yet with lower
heights in place. That said, may need to eventually trend warmer
with strong wly to wswly winds in low levels.
Some question about needing to mention flurries for late tonight
into Fri morning as the main trof moves thru the region. Have held
off mention for now as mdl forecast sounds suggest a lack of
moisture below the mid-deck. That said, mdl guidance has been less
than optimal lately regarding low level moisture profiles.
For the extd...mdl solns begin to differ, mainly regarding low level
features. Have kept low PoPs for Tues and beyond as the ECMWF pulls
a sfc wave further nwd with a slightly more amplified flow. The GFS
seems to be about 12 hrs behind picking up on these sorts of
features and have therefore trended twd the ECMWF. Will monitor to
see if these trends continue. Regardless, low level thermal profiles
suggest temps too warm for anything other than liquid precip.
Tilly
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1125 PM CST Wed Dec 16 2015
Stratus which began across northern MO early late this afternoon has
continued to sink slowly southward through the evening as low
level winds gradually veer to northwesterly. The RAP alone had
been doing a fair job resolving these clouds, but now none of the
guidance appears to be doing well. This forecast is largely based
on extrapolation of the current extensive stratus whose leading
edge runs from roughly KCOU to about 40 miles north of KSTL. The
stratus will continue to spread south/southeast overnight with
cig heights initially low-end VFR lowering to MVFR. Once the
overcast cigs move into the terminals, it should persist through
the remainder of the forecast period.
Specifics for KSTL:
Stratus will move into the terminal overnight with cig heights
initially low-end VFR, lowering to MVFR by daybreak Thursday.
MVFR cigs should then persist through the remainder of the
forecast period.
Glass
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 40 27 43 26 / 5 5 0 0
Quincy 37 24 38 20 / 5 0 0 0
Columbia 38 24 41 25 / 5 5 0 0
Jefferson City 40 23 42 24 / 5 5 0 0
Salem 40 28 40 24 / 5 5 0 0
Farmington 41 24 42 23 / 5 5 0 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1137 PM CST WED DEC 16 2015
.UPDATE:
Issued at 1016 PM CST Wed Dec 16 2015
Increased clouds late tonight through Thursday, as strato cu deck
slowly slides southeast. RAP and HRRR have good handle on this and
used as a guide. Otherwise, chilly conditions tonight with lows
in the upper 20s to low 30s.
Byrd
&&
.SHORT TERM: (Through Late Tonight)
Issued at 333 PM CST Wed Dec 16 2015
(Tonight)
Surface low across north-central Minnesota will northeastward toward
the US-Canadian border tonight. Trailing occluded front will have
passed through the far eastern CWA before this evening begins with
cold advection in its wake. Stratus/stratocu deck has struggled with
its eastward progression today and expect cumulus elements to
dissipate with loss of daytime heating with stratus remaining up
across mainly portions of northeast Missouri tonight. Low
temperatures are expected to range from the mid 20s to around 30
degrees tonight and is a blend of available guidance.
Gosselin
.LONG TERM: (Thursday through Next Wednesday)
Issued at 333 PM CST Wed Dec 16 2015
Cool high pressure will continue building southeast across the Great
Plains on Thursday and into the lower Mississippi Valley on Friday.
Looks like there will be quite a bit of strato-cu on Thursday
afternoon as the the next shortwave digs into the mean long wave
pattern over the Mississippi Valley. This should help to keep
temperatures cool...so I leaned toward the cooler side of guidance
for highs Thursday. The secondary cold front associated with the
shortwave will pass through the area late Thursday, and the second
cooler shot of cold air will slide in on top of us Friday into
Saturday. Temperatures through Saturday morning will be closer to
normal (tho still a bit above) with highs in the low to mid 40s and
lows mainly in the low to mid 20s. The center of the high will move
east of the area by late Saturday bringing southerly flow and
milder temperatures back to the Mid Mississippi Valley.
Sunday through Tuesday will be mild with quasi-zonal flow aloft.
Rain chances increase Sunday into Monday as another cold front moves
through the area. Medium range guidance stalls the front over
southern Missouri/northern Arkansas Monday night. The chance for
precipitation diminishes north of the front, but never really ends.
The front moves back north Tuesday and Tuesday night with rain
chances increasing again through Wednesday. Temperatures look to
remain well above normal...mainly in the 50s and even low 60s for
highs and 30s-40s for lows.
Carney
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1125 PM CST Wed Dec 16 2015
Stratus which began across northern MO early late this afternoon has
continued to sink slowly southward through the evening as low
level winds gradually veer to northwesterly. The RAP alone had
been doing a fair job resolving these clouds, but now none of the
guidance appears to be doing well. This forecast is largely based
on extrapolation of the current extensive stratus whose leading
edge runs from roughly KCOU to about 40 miles north of KSTL. The
stratus will continue to spread south/southeast overnight with
cig heights initially low-end VFR lowering to MVFR. Once the
overcast cigs move into the terminals, it should persist through
the remainder of the forecast period.
Specifics for KSTL:
Stratus will move into the terminal overnight with cig heights
initially low-end VFR, lowering to MVFR by daybreak Thursday.
MVFR cigs should then persist through the remainder of the
forecast period.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1017 PM CST WED DEC 16 2015
.UPDATE:
Issued at 1016 PM CST Wed Dec 16 2015
Increased clouds late tonight through Thursday, as strato cu deck
slowly slides southeast. RAP and HRRR have good handle on this and
used as a guide. Otherwise, chilly conditions tonight with lows
in the upper 20s to low 30s.
Byrd
&&
.SHORT TERM: (Through Late Tonight)
Issued at 333 PM CST Wed Dec 16 2015
(Tonight)
Surface low across north-central Minnesota will northeastward toward
the US-Canadian border tonight. Trailing occluded front will have
passed through the far eastern CWA before this evening begins with
cold advection in its wake. Stratus/stratocu deck has struggled with
its eastward progression today and expect cumulus elements to
dissipate with loss of daytime heating with stratus remaining up
across mainly portions of northeast Missouri tonight. Low
temperatures are expected to range from the mid 20s to around 30
degrees tonight and is a blend of available guidance.
Gosselin
.LONG TERM: (Thursday through Next Wednesday)
Issued at 333 PM CST Wed Dec 16 2015
Cool high pressure will continue building southeast across the Great
Plains on Thursday and into the lower Mississippi Valley on Friday.
Looks like there will be quite a bit of strato-cu on Thursday
afternoon as the the next shortwave digs into the mean long wave
pattern over the Mississippi Valley. This should help to keep
temperatures cool...so I leaned toward the cooler side of guidance
for highs Thursday. The secondary cold front associated with the
shortwave will pass through the area late Thursday, and the second
cooler shot of cold air will slide in on top of us Friday into
Saturday. Temperatures through Saturday morning will be closer to
normal (tho still a bit above) with highs in the low to mid 40s and
lows mainly in the low to mid 20s. The center of the high will move
east of the area by late Saturday bringing southerly flow and
milder temperatures back to the Mid Mississippi Valley.
Sunday through Tuesday will be mild with quasi-zonal flow aloft.
Rain chances increase Sunday into Monday as another cold front moves
through the area. Medium range guidance stalls the front over
southern Missouri/northern Arkansas Monday night. The chance for
precipitation diminishes north of the front, but never really ends.
The front moves back north Tuesday and Tuesday night with rain
chances increasing again through Wednesday. Temperatures look to
remain well above normal...mainly in the 50s and even low 60s for
highs and 30s-40s for lows.
Carney
&&
.AVIATION: (For the 00z TAFs through 00z Thursday Evening)
Issued at 526 PM CST Wed Dec 16 2015
Main concern through the forecast period is potential for stratus
or stratocu. Currently a very large area of stratus exists within
the cyclonic flow from northern MO through the northern Plains and
upper MS Valley. The southern portion of this stratus consists of
low-end VFR cig heights and those will impact KUIN this evening.
Overnight the low level flow will veer to northwesterly and this
should allow the stratus to advance southward some and MVFR cigs
to spread into KUIN. The extent of the southward spread is the
big unknown and present plans will have the southern edge north of
I-70 at 12z, and then developing southward into KCOU and the St.
Louis terminals during the day on Thursday. Will monitor trends
closely tonight as at least one piece of guidance suggests the
stratus may move into KCOU/KSTL closer to 09-10z.
Specifics for KSTL:
Watching a large area of stratus to the north carefully. Current plans
are to keep it north of the terminal tonight into Thursday morning,
with overcast MVFR cigs by midday Thursday. Will monitor trends
closely tonight as at least one piece of guidance suggests the
stratus may move into closer to 09-10z.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1152 PM CST WED DEC 16 2015
.UPDATE...
ISSUED AT 1152 PM CST WED DEC 16 2015
SATELLITE SHOWS THE BANK OF STRATUS HAS MOVED BACK IN AND WAS
DROPPING SSE AROUND 20 KTS. USED THE TIMING TOOL TO INCREASE
CLOUDS THE REST OF THE NIGHT AS THE MODELS OTHER THAN THE RAP ARE
NOT HANDLING THIS STRATUS WELL AT ALL. WE MAY NEED TO MAKE SOME
ADJUSTMENTS TO TEMPS BASED ON THIS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 351 PM CST WED DEC 16 2015
MAINLY A TEMPERATURE FORECAST ALONG WITH DEALING WITH THE
POSSIBILITY OF SOME FLURRIES IN OUR SOUTHWEST ON THURSDAY.
AS THE CLOSED LOW IN THE NORTHERN PLAINS CONTINUES TO PULL
NORTHEAST...OUR SURFACE PRESSURE GRADIENT WILL RELAX. ALONG WITH
DECREASED LOW-LEVEL LAPSE RATES AS THE SUN SETS THIS EVENING...
THIS SHOULD ALLOW WIND SPEEDS TO DECREASE SOME FOR TONIGHT. MOST
CUMULUS THAT WE HAVE AROUND IN THE LATE AFTERNOON WILL DISSIPATE
AS LOW- LEVEL LAPSE RATES RELAX.
MID AND HIGH LEVEL CLOUDS WILL EVENTUALLY BE ON THE INCREASE BY
LATE TONIGHT AS A SHORTWAVE TROUGH CURRENTLY ABOUT TO ENTER THE
NORTHERN ROCKIES WILL DIVE SOUTHEAST INTO THE CENTRAL/SOUTHERN
PLAINS BY THURSDAY MORNING. WE MAY BE CLOSE ENOUGH TO THE MAIN
FORCING OF THIS WAVE TO GET SOME SNOW FLURRIES IN OUR SOUTHWESTERN
CWA DURING THE DAY ON THURSDAY. THE AXIS OF THE SHORTWAVE TROUGH
WILL EXTEND NORTH INTO OUR CWA ON THURSDAY...AS WE CONTINUE TO BE
WITHIN THE MEAN LONGWAVE TROUGH...AS IT TOO MAKES ITS WAY EAST.
THIS WILL MAKE FOR A RATHER CLOUDY DAY FOR THURSDAY...AND ALONG
WITH FAIRLY BRISK NORTHWEST WIND...WILL NOT BE EXACTLY THE MOST
PLEASANT DAY AS HIGHS STRUGGLE INTO THE 20S WITH WIND SPEEDS IN
THE 10 TO 20 MPH RANGE. KEPT TEMPERATURES SIMILAR TO PREVIOUS
FORECAST...ALTHOUGH I DID BUMP DOWN TEMPERATURES A BIT IN OUR
WEST/NORTH FOR TONIGHT WHERE THERE IS MORE SNOW COVER.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 351 PM CST WED DEC 16 2015
MODELS ARE IN GOOD AGREEMENT AT THE START OF THE LONG TERM PERIOD
THURSDAY NIGHT...SHOWING MORE SHARP NWRLY FLOW BUILDING IN FROM
THE WEST...SET UP BETWEEN A DEPARTING TROUGH INTO THE GREAT
LAKES/MIDWEST AND A RIDGE AXIS PUSHING EAST THROUGH THE ROCKIES.
AT THE SFC...EXPECTING WRLY WINDS TO BE IN PLACE...AS THE CWA SITS
ON THE NRN EDGE OF AN AREA OF HIGH PRESSURE SLIDING INTO THE SRN
PLAINS. THE FORECAST REMAINS DRY WITH NO NOTABLE DISTURBANCES IN
THE AREA. EXPECTING LITTLE OVERALL CHANGE AS WE GO THROUGH THE
DAYTIME HOURS FRIDAY...BUT SHOULD SEE A LITTLE BIT OF A BUMP IN
TEMPERATURES...WITH MODELS SHOWING THE AIRMASS OVER THE AREA
WARMING SOME. CURRENT FORECAST CALLS FOR NEAR 30 IN THE NORTH TO
NEAR 40 IN THE SOUTH.
LOOKING AHEAD TO THE UPCOMING WEEKEND...NO CHANGES WERE MADE TO
THE DRY FORECAST...THOUGH CONFIDENCE IN SUNDAY IS NOT THE HIGHEST.
BY SUNRISE SATURDAY...MODELS REMAIN IN GOOD AGREEMENT...SHOWING
THE UPPER LEVEL RIDGING HAVING SHIFTED EAST INTO THE PLAINS
STATES. WINDS FRIDAY NIGHT BECOME MORE LIGHT/VARIABLE...TURNING
MORE SOUTHERLY WITH TIME AS THE CWA COMES UNDER INCREASING
INFLUENCE OF A TROUGH OF LOW PRESSURE DEVELOPING OVER THE HIGH
PLAINS. EXPECTING ADDITIONAL MODERATION OF THE AIRMASS OVER THE
REGION...AND AT THIS TIME SATURDAY IS FORECAST TO BE THE WARMEST
DAY OF THE PERIOD...WITH HIGHS IN THE MID 40S TO NEAR 50. THE
UPPER LEVEL RIDGING CONTINUES SHIFTING EAST...PUSHED BY A
DISTURBANCE WHICH BY SUNDAY MORNING IS MAKING ITS WAY THROUGH CO.
DURING THE AFTERNOON/EARLY EVENING HOURS...THIS DISTURBANCE LOOKS
TO CROSS THE CENTRAL PLAINS...BUT WITH AN OVERALL LACK OF
MOISTURE...MODELS ARE NOT PUTTING OUT MUCH QPF. AT THIS POINT KEPT
EVEN THE MENTION OF SPRINKLES/FLURRIES OUT...BUT WILL HOW MODELS
TREND WITH THIS FEATURE. THIS DISTURBANCE IS EXPECTED TO PUSH A
COLD FRONT THROUGH THE REGION DURING THE DAYTIME HOURS...MAKING
FOR A LOWER CONFIDENCE TEMP FORECAST. HIGHS CURRENT FORECAST TO
RANGE FROM THE UPPER 30S IN THE NORTH TO NEAR 50 IN THE FAR SOUTH.
THROUGH THE FIRST HALF OF THE NEXT WORK WEEK...THE UPPER LEVEL
PATTERN REMAINS MORE ZONAL IN NATURE. WHILE THERE IS DECENT
AGREEMENT WITH MONDAY STAYING DRY...THERE IS A LITTLE MORE
UNCERTAINTY FOR TUE/WED. MODELS SHOWING THE POTENTIAL FOR WEAK
DISTURBANCES AROUND...BUT DIFFER SOME WITH TIMING/LOCATION. KEPT
THINGS DRY...WILL SEE WHAT THE TREND GOES TOWARD. FORECAST TEMPS
ARE A BLEND...GENERALLY NEAR 40 IN THE NORTH...MID 40S SOUTH.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z THU NIGHT)
ISSUED AT 1152 PM CST WED DEC 16 2015
SIGNIFICANT WEATHER: MVFR CIGS THRU SUNRISE.
REST OF TONIGHT: MVFR OVC. NW WINDS UNDER 10 KTS. CONFIDENCE: HIGH
THU: MVFR OVC SHOULD DEPART 12Z-15Z. EXACT TIMING IS UNCERTAIN.
THEN VFR CIGS AROUND 8K FT. NW WINDS AROUND 10 KTS. CONFIDENCE:
MEDIUM
THU EVE: VFR CLOUDS DECREASE. W WINDS JUST UNDER 10 KTS.
CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...HEINLEIN
LONG TERM...ADP
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1155 PM CST WED DEC 16 2015
.UPDATE...
ISSUED AT 1155 PM CST WED DEC 16 2015
LATEST SUITE OF SATELLITE IMAGERY SHOWS OVERCAST CONDITIONS
NORTH/SOUTH CENTRAL WITH A CLEARING POCKET WEST. A SHORTWAVE WAS
SEEN SLIDING INTO NORTHEAST MONTANA WITH A TRACE OF PRECIPIATION
AT GLASGOW IN THE LAST HOUR. THIS SHORTWAVE AND PRECIPITATION
SHOULD JUST FALL SHORT OF CLIPPING FAR SOUTHWEST NORTH DAKOTA
OVERNIGHT. HOWEVER ANOTHER AREA OF CLOUDS WILL FOLLOW THIS
SHORTWAVE...SO THE CLEAR CONDITIONS WEST WILL BE TEMPORARY.
FOLLOWED THE LATEST HRRR FOR SKY GRIDS AND THIS WAS IN LINE WITH
THE PREVIOUS FORECAST. COLD AIR ADVECTION CONTINUES OVERNIGHT
THROUGH THURSDAY MORNING WITH AN H85 POCKET OF -16C CURRENTLY OVER
NORTHWEST NORTH DAKOTA...SPREADING INTO SOUTH CENTRAL BY 18Z
THURSDAY. BRISK NORTHWEST WINDS OF 15 TO 30 MPH WILL PERSIST
OVERNIGHT WITH ISOLATED TO SCATTERED FLURRIES AS CYCLONIC FLOW
DOMINATES.
UPDATE ISSUED AT 929 PM CST WED DEC 16 2015
UPDATES WITH THIS CYCLE INCLUDED SLIGHTLY REFINING POPS/WEATHER IN
EAST CENTRAL AND NORTH CENTRAL ND TO REFLECT A GRADUAL DROP-OFF IN
LIGHT SNOW THROUGH 06 UTC...WITH RENEWED FLURRY/LIGHT SNOW CHANCES
AGAIN LATE TONIGHT...AND ADJUSTING SKY COVER IN WESTERN ND WHERE A
DISTINCT CLEARING LINE HAS ADVANCED EASTWARD AS OF 03 UTC. RECENT
HRRR SIMULATIONS CAPTURE BOTH ONGOING OBSERVED TRENDS AND ANOTHER
WEAK SHORTWAVE TROUGH WHICH WILL APPROACH OUT OF CANADA AFTER 06
UTC. THAT WAVE WILL CAUSE CLOUDS TO INCREASE ONCE MORE IN WESTERN
ND AND MAY OFFER UP MORE FLURRIES OR LIGHT SNOW IN NORTH CENTRAL
ND THANKS TO MODEST QG-FORCING.
UPDATE ISSUED AT 550 PM CST WED DEC 16 2015
WE WILL LET THE WINTER WEATHER ADVISORY AND WINTER STORM WARNING
EXPIRE AS PLANNED AT 6 PM CST AS CONDITIONS ARE SLOWLY IMPROVING
OVER EAST CENTRAL ND AND THE JAMES RIVER VALLEY.
OTHERWISE...FOR THIS UPDATE WE DID CHOOSE TO CARRY LIKELY POPS
FOR LIGHT SNOW FROM BOTTINEAU TOWARD JAMESTOWN FOR A FEW MORE
HOURS IN RESPECT TO RADAR AND AWOS/ASOS OBSERVATIONS. THERE WILL
BE LITTLE IF ANY ADDITIONAL ACCUMULATION THOUGH. WE ALSO DECIDED
TO ADD FLURRIES TO THE FORECAST OVERNIGHT FOR MUCH OF NORTHWEST
AND CENTRAL ND GIVEN PERSISTENCE OF A SATURATED/STRATUS LAYER IN
THE DENDRITIC GROWTH ZONE PER MODEL-FORECAST SOUNDINGS...AND AT
LEAST WEAK VERTICAL MOTION IN THAT LAYER TOO.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 256 PM CST WED DEC 16 2015
THE SHORT TERM PERIOD WILL SEE THE WINTER STORM DIMINISH THIS
AFTERNOON. ALL WARNINGS/ADVISORIES SHOULD BE DONE BY 6 PM CST. FOR
THE REMAINDER OF THE AFTERNOON THE SNOW WILL DIMINISH BUT AREAS OF
BLOWING SNOW WILL CONTINUE...ESPECIALLY IN OPEN COUNTRY
TONIGHT IT WILL CONTINUE TO BE BREEZY ACROSS THE WEST AND CENTRAL.
BUFKIT SOUNDINGS SHOW CONTINUED MOMENTUM TRANSFER TO THE SURFACE
THROUGH THE BOUNDARY LAYER AIDED BY STRONG COLD ADVECTION.
SKIES WILL REMAIN CLOUDY ACROSS THE REGION WITH A SLOW DECREASE IN
CLOUDS AFTER MIDNIGHT. WITH MIN TEMPERATURES IN THE SINGLE DIGITS
NORTH WIND CHILLS WILL FALL AS LOW AS 15 BELOW NORTH.
ON THURSDAY THE REGION MAY GET A PEAK AT THE SUN FINALLY AS CLOUDS
DECREASE. HIGHS WILL BE COOL RANGING FROM 12 NORTH CENTRAL TO AROUND
20 SOUTHWEST.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 256 PM CST WED DEC 16 2015
THE LONG TERM STARTS COLD AND ENDS WARM.
HIGH PRESSURE AND NORTHWEST WINDS WILL USHER IN COLD AIR THURSDAY
AND FRIDAY. TEMPERATURES IN THE TEENS FOR HIGHS AND BELOW ZERO FOR
LOWS ARE LIKELY THURSDAY AND FRIDAY. WIND CHILLS WILL ALSO BECOME
A FACTOR ON FRIDAY MORNING. READINGS AROUND 20 BELOW ARE POSSIBLE.
WARM AIR ADVECTION WILL KICK IN BY THE WEEKEND. ABOVE NORMAL
TEMPERATURES ARE EXPECTED THROUGH THE MIDDLE OF NEXT WEEK. SEVERAL
WEAK UPPER LEVEL SHORT WAVE TROUGHS ARE DEPICTED IN THE
MODELS...HOWEVER...THERE IS A GREAT DEAL OF DISPARITY FROM ONE
MODEL TO THE NEXT. THEREFORE...SLIGHT CHANCES FOR PRECIPITATION
EXIST THIS WEEKEND INTO EARLY NEXT WEEK...BUT THERE IS TOO MUCH
UNCERTAINTY TO PINPOINT EXACT TIMING OR LOCATIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1155 PM CST WED DEC 16 2015
MVFR TO VFR CIGS EXPECTED THROUGH 18Z THURSDAY...THEN VFR CONDITIONS
AT ALL TERMINALS. BRISK NORTHWEST WINDS 15KT TO 25KT WILL CONTINUE
THROUGH 00Z SATURDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...WAA
LONG TERM...AJ
AVIATION...KS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
126 AM EST THU DEC 17 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT. WESTERLY WINDS
WILL SET UP BEHIND THE COLD FRONT. A SECONDARY COLD FRONT WILL
MOVE ACROSS THE REGION FRIDAY AFTERNOON AND EVENING.
&&
.NEAR TERM /THROUGH TODAY/...
PRE FRONTAL SHOWERS HAVE CONTINUED THIS EVENING AHEAD OF A SURFACE
COLD FRONT WHICH IS CURRENTLY MOVING THROUGH INDIANAPOLIS. AN
UPPER LEVEL DISTURBANCE CAN ALSO BE SEEN ON WATER VAPOR THIS
EVENING EJECTING OFF TOWARDS THE NORTHEAST. ALONG AND AHEAD OF THE
DISTURBANCE WIDESPREAD SHOWERS HAVE FORMED. THE MAIN QUESTION WILL
BE WHERE EXACTLY THE UPPER LEVEL DISTURBANCE TRACKS. LATEST HRRR
AND RAP CONTINUE TO SHOW MOST OF THE PRECIP MOVING ACROSS THE
EASTERN ZONES BUT DON`T APPEAR TO BE HANDLING LATEST RADAR TRENDS
THAT WELL. HAVE GONE AHEAD AND MOVED HIGHER POPS SLIGHTLY WEST TO
ACCOUNT FOR ONGOING TRENDS.
DURING THE DAY THURSDAY MUCH COLDER 850 TEMPERATURES ARE
FORECASTED TO COME AS THE UPPER LEVEL LOW EJECTS OFF TOWARDS THE
NORTHEAST. THE GFS IS MORE PROGRESSIVE PUSHING COLDER 850 TEMPS IN
QUICKER THAN THE NAM (-2 DEGREES C LOOKS LIKELY BY THURSDAY
AFTERNOON). EVEN THOUGH TEMPERATURES WILL FEEL MUCH COLDER HIGHS
WILL BE NEAR NORMAL VALUES FOR THIS TIME OF YEAR. CLOUDS LOOK TO
ALSO WILL HANG AROUND IN THE MORNING WITH CU DEVELOPMENT EXPECTED
DURING THE AFTERNOON AS LOW LEVEL LAPSE RATES STEEPEN A BIT.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
SHOWERS MAY STILL BE ONGOING IN THE SOUTHEAST COUNTIES AT THE
BEGINNING OF THE PERIOD BEFORE CLEARING OUT IN THE MORNING.
CLOUDS WILL DIMINISH BUT THEN THERE WILL PROBABLY BE SOME
REDEVELOPMENT OF STRATOCUMULUS WITH COLD AIR ADVECTION AND
HEATING. TEMPERATURES WILL LIKELY NOT RISE MUCH FROM THE MORNING
LOWS.
LONG WAVE TROUGH AXIS WILL REMAIN WEST OF THE REGION UNTIL SHORT
WAVE ENERGY MOVING THROUGH THE TROUGH CAUSES IT TO SHIFT EAST ON
FRIDAY NIGHT. THIS WILL RESULT IN A SECONDARY COLD FRONT MOVING
THROUGH THE AREA FRIDAY AFTERNOON AND EVENING. WHILE MOISTURE WILL
BE LIMITED...IT LOOKS LIKE SOME SNOW SHOWERS MAY DEVELOP AS THE
COLD FRONT AND STRONGER SHORT WAVE MOVES THROUGH. APPEARS THAT
THIS DEVELOPMENT WILL OCCUR AS THE SYSTEM IS TRACKING ACROSS THE
AREA. SO POPS INCREASE FROM WEST TO EAST FRIDAY AFTERNOON AND
THEN DIMINISH QUICKLY FRIDAY EVENING. CANNOT RULE OUT SOME
LINGERING FLURRIES ON FRIDAY NIGHT. WENT A BIT ABOVE MOS FOR LOWS
BOTH THURSDAY NIGHT AND FRIDAY NIGHT. STAYED CLOSE TO MOS FOR
FRIDAY HIGHS.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
ALTHOUGH THE LONG TERM WILL START OUT DRY AN UNSETTLED WEATHER
PATTERN IS TAKING SHAPE FOR NEXT WEEK. HIGH PRESSURE WILL BE
SITUATED ACROSS THE FA ON SATURDAY BEFORE BEGINNING TO SHIFT OFF TO
THE EAST ON SUNDAY. THIS WILL ALLOW FOR A DECENT INCREASE IN HIGH
TEMPERATURE VALUES FROM SATURDAY TO SUNDAY.
WITH AN INCREASE IN CLOUDS SUNDAY NIGHT DO NOT EXPECT TEMPERATURES
TO DROP TOO MUCH OVERNIGHT. ALTHOUGH THERE ARE SOME SUBTLE TIMING
DIFFERENCES WITH THE START OF THE RAIN OVERNIGHT SUNDAY NIGHT INTO
MONDAY MORNING THERE IS GENERAL AGREEMENT WITH THE BULK OF THE
PRECIPITATION BEGINNING TO MOVE INTO THE AREA AFTER MIDNIGHT SUNDAY
NIGHT AND BEFORE SUNRISE MONDAY MORNING.
SEVERAL ROUNDS OF PRECIPITATION ARE THEN EXPECTED FROM THE SUNDAY
NIGHT INTO WEDNESDAY TIME PERIOD. TEMPERATURE PROFILES ARE
INDICATING THAT PRECIPITATION IS EXPECTED TO BE IN THE FORM OF
RAIN FOR THIS EVENT. DEPENDING ON THE WHERE THE EXACT MOISTURE
PLUMES SET UP...WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR
FLOODING DUE TO SEVERAL ROUNDS OF EXPECTED RAINFALL. OVERALL
EXPECT ABOVE NORMAL TEMPERATURES AND PRECIPITATION FOR THIS TIME
PERIOD.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AREA OF SHRA CONTINUES TO LIFT N ACROSS ERN KY INTO SOUTH CENTRAL
OHIO...AFFECTING AREAS MAINLY SE OF I-71. PCPN HAS ALREADY ENDED
AT THE WRN TAFS...LEAVING JUST KILN/KCMH/KLCK TO GET GRAZED BY
THE PCPN. CIGS ARE MAINLY VFR...BUT THERE ARE POCKETS OF MVFR CIGS
ACROSS THE REGION ALSO.
CDFNT IN ERN INDIANA WILL PUSH ACROSS THE TAFS THIS
MORNING...TURNING THE WINDS TO THE W/NW. CLOUDS WILL SCATTER OUT A
COUPLE OF HOURS AFTER FROPA.
QUESTION THEN BECOMES...WILL WRAP AROUND CLOUDS WORK BACK INTO
THE TAFS. LOOKING AT NAM MOISTURE TIME SECTIONS...MVFR CIGS WILL
WORK INTO KDAY AROUND 18Z...AND WILL GRADUALLY PROGRESS INTO THE
REST OF THE TAFS BY 00Z. THE EXCEPTION IS KCVG/KLUK WHERE THE CIGS
COULD COME BACK IN VFR. CIGS ARE EXPECTED TO LOWER INTO MVFR AFT
00Z FRIDAY.
OUTLOOK...MVFR CEILINGS POSSIBLE TONIGHT INTO FRIDAY. MVFR
CEILINGS AND VISIBILITIES ARE POSSIBLE ON MONDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HAINES
NEAR TERM...HAINES
SHORT TERM...
LONG TERM...NOVAK
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
331 AM CST THU DEC 17 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CST THU DEC 17 2015
FOCUSED ON WIND FORECASTS THROUGH FRIDAY WITH STEEP BOUNDARY LAYER
LAPSE RATES...AND CLOUDS AND LIGHT SNOW CHANCES ALSO COME WITH
THAT.
GOES WATER VAPOR SHOWING NUMEROUS OVERHEAD AND UPSTREAM WEAK
SHORTWAVE TROUGHS...WITH THE STRONGEST CLEARLY VISIBLE OVER
NORTHERN SASKATCHEWAN /WHICH ARRIVES FRIDAY MID-DAY/. REGIONAL
RADARS SHOWING BATCHES OF FLURRIES ACROSS THE NORTHERN STATES IN
CYCLONIC FLOW WITH 3SM+ -SN. BEST ECHO IS IN ERN ND WHICH FITS
WELL WITH RAP ANALYSIS OF LOW-LEVEL COLD ADVECTION AREA. IR
IMAGERY DEPICTING STRATUS OVER MUCH OF THE REGION HOWEVER A
CLEARING LINE WAS WORKING EAST THROUGH THE DAKOTAS AT 09Z WHICH
DOES HAVE MY INTEREST.
NORTHWEST FLOW WILL BRING A NUMBER OF WEAKER SHORTWAVE TROUGHS
THROUGH THE REGION ALONG WITH WAVES OF COLD AIR ADVECTION /CAA/.
THE CAA WAVES WILL STEEPEN LAPSE RATES AND ALLOW MIXING TO ENHANCE
WINDS AND PRECIPITATION CHANCES /FLURRIES/ THROUGH FRIDAY BEFORE
RIDGE BUILDING BEGINS SATURDAY. A COLD ADVECTION PUSH ARRIVES FROM
THE ERN DAKOTAS THIS AFTERNOON WHICH WILL ENHANCE WINDS
AGAIN...ALTHOUGH NOT AS STRONG AS WEDNESDAY GUSTS...BUT 30 MPH IS
POSSIBLE. HAVE ADDED FLURRIES SOUTH TO AROUND I-90 TODAY. THE
SNOW SQUALL PARAMETER IN THE NAM IS VERY /OVERLY?/ EXCITED NORTH
OF I-90 THIS AFTERNOON WITH STEEP LAPSE RATES. BUT THE NAM DOESNT
PRODUCE MEASURABLE PRECIPITATION. RAP FORECASTS HAVE BEEN LESS
THAN ENTHUSED. FORECAST SPLITS THE DIFFERENCE WITH FLURRIES.
CONSENSUS MODEL FORECAST IS TO POSSIBLY TRY TO BREAK SOME SUN
INTO THE SOUTHERN FORECAST AREA TODAY...POSSIBLY THE CLEARING LINE
FROM THE DAKOTAS. WOULD THINK WITH LAPSE RATES AS STEEP IN THE
BOUNDARY LAYER...BREAKS WOULD FILL IN WITH BKN SKIES. HAVE COME
DOWN A BIT IN SKY COVER...BUT STILL IN THE CLOUDY/MOSTLY CLOUDY
RANGE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 331 AM CST THU DEC 17 2015
WAVES OF COLD ADVECTION CONTINUE WITH STEEPER LAPSE RATES INTO
FRIDAY. SASKA SHORTWAVE TROUGH ARRIVES FRIDAY TO ENHANCE LIFT AND
PROVIDE AGAIN A BURST OF FLURRIES...AND DEEPER MIXING. WIND GUSTS
COULD BE IN THE 30 TO 35 MPH RANGE IF REALIZED...AND THE FORECAST
WINDS WERE BUMPED UP SOME. HAVE CONTINUED THE FLURRIES THROUGH
THAT PERIOD..BUT BEST SIGNAL /LOW-LEVEL LAPSE RATES AND WEAK QG
FORCING IN THAT LAYER/ FOR MEASURABLE SNOW IS THROUGH IA AND SWRN
WI. AGAIN...17.00Z NAM MOST AGGRESSIVE ON THIS...BUT 17.06Z NAM
HAS STEPPED BACK FROM MORE AGGRESSIVE PARAMETER SPACE.
SUNDAY INTO MONDAY...
BETTER GROUPING IN THE DETERMINISTIC SUITE ON A MODERATE OPEN
SHORTWAVE TROUGH MOVING THROUGH THE REGION. WARM ADVECTION AND
MOISTURE TRANSPORT CONVERGENT SIGNALS INCREASE SUNDAY...MAINLY
INTO IL/WI WITH PRECIPITATION LOOKING LIKELY THERE /TO OUR EAST/.
17.00Z GFS SOUNDINGS SHOW ANOTHER 2KM SATURATED LAYER WITH NO ICE
INTRODUCTION...AND TEMPERATURES SUPPORTING MAINLY RAIN. FREEZING
RAIN MAY BE POSSIBLE FOR A PERIOD SHOULD THE COLD AIR NOT SCOUR
OUT IN THE WARM ADVECTION EARLY SUNDAY. COLD FRONT WILL MOVE
THROUGH SUNDAY NIGHT WITH A CHANGE OVER TO ALL SNOW. IF THIS WAVE
WERE MORE OF A CLOSED LOW...THERE WOULD BE CONCERN FOR DEFORMATION
SNOW ON THE WEST SIDE OF THE CYCLONE /MN...IA/ DUE TO
PRECIPITATION RATE COOLING...BUT THAT ISNT THE CASE. OVERALL WIND
MAY BE THE MOST IMPACT AGAIN FROM THIS CYCLONE...FORECAST WAS
BOOSTED ABOVE CONSENSUS...BUT LIKELY NOT ENOUGH FOR POST-COLD
FRONT WINDS MONDAY WHICH LOOK LIKE THEY COULD GUST OVER 30 MPH.
WILL TREND THE WIND FORECAST IN THE NEXT DAYS AS NEEDED.
THE REMAINDER OF THE WEEK LOOKS ACTIVE WITH LITTLE IN THE WAY OF
PREDICTABILITY. THERE COULD BE HOLIDAY WEATHER BUT TOO EARLY TO
PROVIDE ANY DETAILS. MILD WEATHER CONTINUES IT SEEMS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1119 PM CST WED DEC 16 2015
THE AREA OF LOW PRESSURE AT THE SURFACE WAS ALONG THE LAKE
SUPERIOR NORTH SHORE LATE THIS EVENING. A BROAD AREA OF CYCLONIC
FLOW REMAINS IN PLACE BEHIND THE LOW WITH MOISTURE AND CLOUDS
TRAPPED BELOW THE INVERSION COVERING MUCH OF THE UPPER MIDWEST.
THE BACK EDGE OF THESE CLOUDS WAS OVER THE CENTRAL DAKOTAS INTO
EASTERN NEBRASKA...ALTHOUGH THERE WERE SOME BREAKS OVER CENTRAL
AND WESTERN MINNESOTA. THE SURFACE LOW WILL CONTINUE TO MOVE
SLOWLY NORTHEAST AWAY FROM THE REGION...BUT THE CYCLONIC
FLOW...MOISTURE AND CLOUDS ARE EXPECTED TO REMAIN THROUGH THURSDAY
EVENING. WILL NOT ATTEMPT TO TIME ANY SHORT LIVED BREAKS THAT MAY
OCCUR AND JUST STAY WITH MVFR CEILINGS FOR BOTH SITES THROUGH THE
PERIOD. THE WEST TO NORTHWEST WINDS WILL REMAIN GUSTY WITH GOOD
LOW LEVEL LAPSE RATES REMAINING IN PLACE...BUT LOOK FOR BOTH THE
SUSTAINED AND GUST SPEEDS TO SLOWLY COME DOWN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...04
AREA FORECAST DISCUSSION
NWS NEW YORK NY
701 AM EST THU DEC 17 2015
.SYNOPSIS...
A WARM FRONT LIFTS TO THE NORTH BY LATE THIS AFTERNOON...FOLLOWED
BY LOW PRESSURE TRACKING OVER THE AREA TONIGHT. THE PASSING LOW
BRINGS A COLD FRONT THROUGH THE REGION LATE TONIGHT...AS THE LOW
TRACKS INTO THE GULF OF MAINE. WEAK LOW PRESSURE DEVELOPS ALONG
THE FRONT ON FRIDAY AS IT SLOWLY TRACKS TO THE EAST. HIGH
PRESSURE BUILDS IN FROM FRIDAY NIGHT THROUGH MONDAY. LOW PRESSURE
APPROACHES FROM THE OHIO VALLEY LATE TUESDAY AND PASSES UP THE ST
LAWRENCE VALLEY ON WEDNESDAY SLOWLY DRAGGING A COLD FRONT ACROSS
THE LOCAL REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE: RADAR SUPPORTS LIGHT PCPN OVER LI AND CT. HAVE DECIDED TO
CALL THIS DRIZZLE AND HAVE ADJUSTED GRIDS TO SHOW THE "MAIN EVENT"
FOR THIS AFTERNOON. LATEST HRRR APPEARS TO HAVE GOOD HANDLE ON IT.
LOOKS LIKE RAIN RAPIDLY OVERSPREADS THE REGION FROM SW TO NE
AROUND NOON.
HAVE ALSO RAISED HOURLY TEMPS BASED ON OBSERVATIONAL TRENDS AND
LATEST LAMP GUIDANCE.
STRONG SHORTWAVE MOVES IN THIS AFTERNOON RESULTING IN MODERATED
RAIN.
FOR HIGHS TODAY ARE A BLEND OF MAV/MET/ECS GUIDANCE WITH NAM
2-METER AND A MIX DOWN FROM 975 HPA PER BUFKIT SOUNDINGS. HIGHS
SHOULD BE AROUND 10-15 DEGREES ABOVE NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
PRECIPITATION TAPPERS OFF FROM SW TO NE TONIGHT AS 700-500 HPA
SHORTWAVES EXIT TO THE NORTHEAST. ANOTHER 700-500 HPA SHORTWAVE
MOVES IN ON FRIDAY. HOWEVER...THE LOW LEVELS WILL BE DRYING OUT ON
WNW-NW DOWNSLOPING LOW LEVEL WINDS. SO HAVE SLIGHT CHANCE TO
CHANCE POPS OVER MAINLY OVER THE SE 1/4 OF THE CWA ON
FRIDAY...CLOSEST TO AN EXITING FRONTAL BOUNDARY WITH A WAVE OF LOW
PRESSURE RIDING ALONG IT. THERE ARE INCREASING INDICATIONS THAT
FRIDAY COULD END UP DRY...JUST DID NOT HAVE THE CONFIDENCE TO GO
WITH A COMPLETELY DRY FORECAST AT THIS TIME.
FOR LOWS TONIGHT...A BLEND OF ECS/MET/MAV GUIDANCE AND NAM 2-METER
TEMPERATURES WAS USED. VALUES SHOULD BE AROUND 15-20 DEGREES ABOVE
NORMAL. RECORD HIGH MINIMUM TEMPERATURES ARE POSSIBLE FOR THURSDAY
AS A RESULT. SEE THE CLIMATE SECTION OF THE AFD FOR DETAILS.
A BLEND OF MET/ECS/MAV GUIDANCE...NAM 2-METER TEMPERATURES AND A
MIX DOWN FROM 925-875 HPA WAS USED FOR HIGHS ON FRIDAY...WITH
READINGS FORECAST TO BE AROUND 10 DEGREES ABOVE NORMAL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
NO MAJOR CHANGES IN THE LONG TERM AT THIS TIME.
UPPER TROUGH AXIS IS OVER THE NORTHEAST ON SATURDAY WITH NW SFC FLOW
AND MODERATELY COLD ADVECTION. LOW LEVEL LAPSE RATES ARE NEAR 9C/KM
UP TO AROUND 800 HPA. THUS...EXPECT A GOOD DEAL OF STRATO
CU...ESPECIALLY INLAND. WITH TEMPS AROUND -15 C IN THE
CLOUDS...EXPECT FLURRIES OR EVEN SNOW SHOWERS OVER THE HUDSON
VALLEY. THESE COULD SPREAD DOWN TO THE COAST AS WELL...THOUGH WOULD
EXPECT MOSTLY VIRGA DUE TO THE HIGH CLOUD BASE.
IT WILL BE A BLUSTERY DAY WITH A WESTERLY FLOW AND HIGH TEMPERATURES
SLIGHTLY BELOW NORMAL. CERTAINLY A MAJOR CHANGE FROM RECENTLY.
DEEP-LAYERED RIDGING ON SUNDAY BRINGS US A SUNNY DAY...AND HIGH
TEMPERATURES WILL BE NEAR NORMAL. HIGH TEMPS WARM UP ON MONDAY ON A
SW FLOW AS HIGH PRESSURE WILL BE OFFSHORE.
WEAKENING LOW PRESSURE OVER THE GREAT LAKES ON MONDAY SPREADS WARM
AIR ADVECTION OVER OUR REGION WITH MID/HIGH CLOUDS. ANOTHER AREA
OF LOW PRESSURE FORMS BY LATE TUESDAY OVER THE OHIO VALLEY AND
SETS UP STRONGER WARM ADVECTION. WHILE UNCERTAINTY IN DETAILS IS
HIGH IT DOES APPEAR THAT RAIN BECOMES LIKELY TUESDAY NIGHT INTO
WEDNESDAY AS THE LOW TRACKS WEST OF THE REGION. LATEST GEFS AND
DETERMINISTIC MODELS SUGGEST THAT DEPTH OF THE SHORTWAVE FORCING
THIS SYSTEM REMAINS RATHER UNCERTAIN. THUS TIMING AND AMOUNT OF
PRECIPITATION REMAINS MAIN AREA OF UNCERTAINTY. LATEST NWP BLEND
DOES SUPPORT INCREASING POPS TO LIKELY FOR TUESDAY NIGHT INTO
WEDNESDAY. WITH TEMPERATURES ABOVE NORMAL...RAIN IS THE ONLY
PRECIPITATION TYPE.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
HIGHLY UNCERTAIN...LOW CONFIDENCE FORECAST AS LOW PRESSURE MOVES
ACROSS THE AREA TERMINALS CAUSING RAPIDLY CHANGING CONDITIONS.
CONDITIONS ACROSS THE REGION CONTINUE TO VARY FROM VFR TO LIFR. VFR
CONDITIONS ARE CURRENTLY BEING OBSERVED AT THE NYC TERMINALS.
THINKING AT THIS TIME THAT THE CITY TERMINALS WILL REMAIN VFR TIL
AROUND 16Z OR SO. THEN ONCE THE RAIN MOVES IN...CONDITIONS BEGIN TO
DETERIORATE. BEFORE 16Z...THERE MAY BE BRIEF PERIODS WHERE
CONDITIONS FALL TO MVFR OR IFR...AS THEY HAVE DONE ALL NIGHT.
OUTSIDE OF THE NYC TERMINALS...CONDITIONS RANGE FROM MVFR TO LIFR.
CONDITIONS MAY VARY BIT THIS MORNING...BUT NO SIGNIFICANT
IMPROVEMENT IS EXPECTED.
CONDITIONS LOWER TO IFR OR LESS EVERYWHERE DURING THE LATE MORNING
AND AFTERNOON WITH THE DEVELOPMENT OF RAIN. AREA OF FOG THEN DEVELOP
LATE THIS AFTERNOON AND EVENING. SOME OF THE FOG MAY BECOME LOCALLY
DENSE...RESTRICTING VSBYS TO LESS THAN A MILE.
A GENERAL SE FLOW 5-10 KT IS EXPECTED TODAY. WINDS BECOME WESTERLY
TONIGHT...THEN NORTHWESTERLY LATE. ONCE THE WINDS BECOME
NORTHWESTERLY...CONDITIONS SHOULD IMPROVE TO MVFR...THEN VFR LATE.
...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 TODAY FOR CHANGING FLIGHT
CATEGORIES IN STRATUS...RAIN...AND FOG. VSBYS MAY FALL BELOW 1 MILE
THIS EVENING.
KLGA FCSTER COMMENTS: AMENDMENTS LIKELY TODAY FOR CHANGING FLIGHT
CATEGORIES IN STRATUS...RAIN...AND FOG. VSBYS MAY FALL BELOW 1
MILE THIS EVENING.
KEWR FCSTER COMMENTS: AMENDMENTS LIKELY TODAY FOR CHANGING FLIGHT
CATEGORIES IN STRATUS...RAIN...AND FOG. VSBYS MAY FALL BELOW 1
MILE THIS EVENING.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH IMPLIES
SLANT RANGE VISIBILITY 4-6SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMENDMENTS LIKELY TODAY FOR CHANGING FLIGHT
CATEGORIES IN STRATUS...RAIN...AND FOG. VSBYS MAY FALL BELOW 1
MILE THIS EVENING.
KHPN FCSTER COMMENTS: AMENDMENTS LIKELY TODAY FOR CHANGING FLIGHT
CATEGORIES IN STRATUS...RAIN...AND FOG.
KISP FCSTER COMMENTS: AMENDMENTS LIKELY TODAY FOR CHANGING FLIGHT
CATEGORIES IN STRATUS...RAIN...AND FOG.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRIDAY...MVFR OR LOWER POSSIBLE WITH A CHANCE OF RAIN FOR TERMINALS
NEAR THE COAST.
.FRIDAY NIGHT...MAINLY VFR. WNW WINDS G20-25KT.
.SATURDAY THROUGH SATURDAY NIGHT...VFR. WNW-W WINDS G25-35KT
DURING THE DAY AND G20-25 KT AT NIGHT.
.SUNDAY-SUNDAY NIGHT...VFR. W WINDS G15-20KT.
.MONDAY...VFR. SW WINDS G15-25KT. SLIGHT CHANCE OF SHOWERS MON
AFT/NIGHT.
&&
.MARINE...
A RELATIVELY RELAXED PRESSURE GRADIENT OVER THE WATERS TODAY WILL
KEEP WINDS TO 15 KT OR LESS. WINDS INCREASE WITH A COLD FRONTAL
PASSAGE TONIGHT...WITH GUSTS TO 25 KT AND SEAS BUILDING TO 5 FT ON
THE COASTAL OCEAN WATERS...HOWEVER SUB-SCA CONDITIONS ARE EXPECTED
ON THE NON-OCEAN ZONES TONIGHT. COLD AIR ADVECTION ON FRIDAY WILL
LEAD TO CONTINUED SCA CONDITIONS ON THE COASTAL OCEAN WATERS...AND
POSSIBLY ON THE NON-OCEAN WATERS.
FOR FRIDAY NIGHT...SCA CONDITIONS ARE EXPECTED AND GALES ARE
POSSIBLE ON THE COASTAL OCEAN WATERS...WITH SMALL CRAFT CONDITIONS
LIKELY ON THE NON-OCEAN ZONES.
AS A RESULT HAVE ISSUED A SMALL CRAFT ADVISORY FROM AFTER
MIDNIGHT TONIGHT THROUGH FRIDAY NIGHT ON THE COASTAL OCEAN
WATERS. AT THIS TIME CONFIDENCE IS NOT HIGH ENOUGH TO ISSUE A GALE
WATCH FOR THE COASTAL OCEAN WATERS FOR FRIDAY NIGHT.
LONG TERM...WESTERLY GALES APPEAR LIKELY BY SATURDAY AFTERNOON.
WINDS THEN DIMINISH ON SUNDAY WITH A HIGH PRESSURE RIDGE SHIFTING
THROUGH. THIS RELATIVELY SHORT-LIVED TRANQUIL PERIOD THEN ENDS ON
MONDAY WITH THE PRESSURE GRADIENT/WINDS/SEAS INCREASING ONCE AGAIN
ON A SW FLOW.
&&
.HYDROLOGY...
FROM AROUND 1/2 TO 3/4 OF INCH OF RAIN IS FORECAST THROUGH THIS
EVENING...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. LOCALIZED PONDING
OF WATER ON ROADWAYS...MAINLY IN URBAN/POOR DRAINAGE AREAS IS
POSSIBLE AS A RESULT.
THE NEXT RAINFALL IS FORECAST LATE TUESDAY INTO WEDNESDAY. THIS
COULD BE A PROLONGED EVENT WITH BASIN TOTALS OF UP TO 1.5 INCHES.
NO HYDROLOGIC PROBLEMS THOUGH ARE FORESEEN OTHER THAN POSSIBLE
URBAN PONDING.
&&
.CLIMATE...
RECORD HIGH MINIMUM TEMPERATURES FOR TODAY...DECEMBER 17
LOCATION...RECORD/YEAR...FORECAST LOW
NEWARK.........45/1992........46
BRIDGEPORT.....43/1992*.......43
CENTRAL PARK...48/1984*.......47
LAGUARDIA......48/1984........47
J.F. KENNEDY...48/1984........48
ISLIP..........46/1984........49
* AND IN PREVIOUS YEARS
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EST
SATURDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...MALOIT/TONGUE
NEAR TERM...MALOIT/TONGUE
SHORT TERM...MALOIT
LONG TERM...TONGUE
AVIATION...BC
MARINE...MALOIT/TONGUE
HYDROLOGY...MALOIT/TONGUE
CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1010 AM EST THU DEC 17 2015
.SYNOPSIS...
LOW PRESSURE AND A COLD FRONT WILL MOVE ACROSS OUR AREA LATE TODAY
AND EARLY TONIGHT. A STRONG AREA OF HIGH PRESSURE BUILDS TO OUR SOUTH
AND WEST FRIDAY AND SATURDAY, THEN BRIEFLY SETTLES OVER OUR REGION
SUNDAY BEFORE MOVING OFFSHORE. A WEAK COLD FRONT WILL APPROACH ON
TUESDAY, HOWEVER IT MAY STALL JUST TO OUR WEST BEFORE ANOTHER COLD
FRONT APPROACHES LATE WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RAIN IS IN THE PROCESS OF ARRIVING AND VERY LITTLE CHANGE TO
TIMING MADE ON THE MID-MORNING UPDATE. TEMPERATURES WERE RUNNING
A LITTLE HIGHER THAN FORECAST EARLIER THIS MORNING BUT EVAPORATIVE
COOLING AS RAIN ARRIVES HAS KICKED IN AND FORECAST TEMPERATURES
LOOK GOOD FOR THE REMAINDER OF THIS TIME PERIOD.
PREVIOUS DISCUSSION. RAIN HAS BEEN POPPED PER HRRR ONSET 12Z- 15Z
E PA THIS MORNING... DELAYED SLIGHTLY FROM EARLIER FORECASTS THEN
ROBUST 3-6 HR PERIOD OF SHOWERY RAINS MIDDAY/MID AFTN EVERYWHERE.
SOME OF THE RAIN WILL BE BRIEFLY HEAVY NEAR THE PATH OF THE SFC
LOW IN THE SLIGHTLY MORE UNSTABLE AIR AND THAT SHOULD BE NJ/DE AS
PER THE WPC QPF. MOST OF THE RAIN IN THE 15Z-22Z TIME FRAME.
QPF GENERALLY .3 TO .8 INCHES WITH A FEW 1.25 INCH AMOUNTS
POSSIBLE, ESPECIALLY NJ/DE. HWO FB AND TWEET HAS THE HEAVY RAIN
HAZARD.
SE WIND BRIEFLY INCREASES DURING MIDDAY WITH GUSTS 20 MPH S NJ
COAST AS WELL AS DELAWARE, WHILE THE WIND IN E PA MAY TURN LIGHT
NE. A WIND SHIFT EVERYWHERE TO SOUTHWEST OR WEST LATE IN THE DAY
WITH LOW PRES AND A BROAD CFP PASSING THROUGH AND THEN EAST OF OUR
COASTS.
FOG IN THE FORECAST THIS AFTN IN THE BROAD PATH OF LOW PRES AND A
WEAK GRADIENT, ESPECIALLY SUNSET ONWARD WHEN DRY SLOT PASSES THROUGH
ALOFT. SOME OF THAT FOG COULD BE DENSE AND FORESEE A SPS POTENTIAL
FOR FOG LATE IN THE DAY.
FORECAST ELEMENTS WERE DERIVED FROM A 50 50 BLEND OF THE 00Z/17
GFS/NAM MOS. HOWEVER, BECAUSE OF WETBULBING AND RAIN, I BLENDED
THE TEMPS WITH THE COOLER NAM 2 M TEMPS. CONFIDENCE ON LOWERING
TEMPS FROM GUIDANCE I-95 NWWD IS ONLY AVERAGE.
AS FOR CLIMO...MAX TEMPS ABOUT 10F ABOVE NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
PROBABLY PATCHY FOG, POSSIBLY DENSE ALONG AND SE OF I-95 DURING THE
EVENING. LEFTOVER SHOWERS ALONG THE COASTS DURING THE EVENING.
DOUBTING IF ANY MEASURABLE RAIN AFTER MIDNIGHT. OTRW...MO CLOUDY.
WIND BECOMING NORTHWEST AND INCREASING AFTER MIDNIGHT WHEN THE
DEWPOINTS TUMBLE AND VSBY IMPROVES CONSIDERABLY.
FORECAST ELEMENTS WERE DERIVED FROM A 50 50 BLEND OF THE 00Z/17
GFS/NAM MOS.
CLIMO: LOWS ABOUT 15F WARMER THAN NORMAL.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF AN AMPLIFIED UPPER-LEVEL TROUGH
SETTLING INTO THE EAST FRIDAY NIGHT AND SATURDAY BEFORE LIFTING
NORTHEASTWARD SUNDAY. THIS DELIVERS MUCH COLDER AIR INTO THE EAST,
HOWEVER THE FLOW IS PROGRESSIVE AND THEREFORE THE COLD SHOT IS SHORT
IN DURATION. AS ENERGY ACROSS THE WEST MOVES INTO THE CENTRAL PLAINS
LATER IN THE WEEKEND, RIDGING RETURNS ACROSS THE EAST. THIS WILL
ALLOW A WARMING TREND TO OCCUR NEXT WEEK, WITH POTENTIALLY NEAR
RECORD WARMTH STARTING ON WEDNESDAY. THE MAIN WEATHER FEATURE IS A
FRONTAL ZONE WITH WAVES OF LOW PRESSURE ALONG IT OFFSHORE FRIDAY
NIGHT, THEN A POTENTIALLY SLOW MOVING FRONT ARRIVING TUESDAY INTO
THURSDAY. WE USED A MODEL BLEND FRIDAY THROUGH SUNDAY, THEN A 00Z
WPC/CONTINUITY BLEND THEREAFTER. SOME ADJUSTMENTS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.
FOR FRIDAY...THERE SHOULD BE GRADUAL CLEARING AS THE FRONT AND
SURFACE WAVE IS OFFSHORE, HOWEVER SOME OVERRUNNING WEST OF THE
BOUNDARY AS ANOTHER LOW RUNS UP THE FRONT COULD LINGER SOME SHOWERS
NEAR THE COAST IN THE MORNING. OVERALL THOUGH THE BULK OF THE
PRECIPITATION SHOULD REMAIN OFFSHORE, THEREFORE HELD ONTO SOME
SLIGHT CHC TO LOW CHC POPS IN THE MORNING MAINLY FROM THE COAST ON
EASTWARD. CAA ARRIVES THROUGH THE DAY AND REALLY KICKS IN BY LATE IN
THE DAY. THERE IS THE POTENTIAL FOR SOME FLURRIES OR SNOW SHOWERS
GETTING TO THE POCONOS LATER AT NIGHT AS A MUCH COLDER AIRMASS TURNS
THE LAKE EFFECT MACHINE ON. WE ARE ANTICIPATING A BREEZE, WHICH MAY
INCREASE SOME AS THE CAA DEEPENS AND THE PRESSURE GRADIENT TIGHTENS.
FOR SATURDAY AND SUNDAY...A STRONG UPPER-LEVEL TROUGH SWINGS ACROSS
THE EAST SATURDAY BEFORE LIFTING NORTHEASTWARD SUNDAY. THIS FEATURE
WILL HAVE MUCH COLDER AIR WITH IT, WITH STRONG CAA OCCURRING
SATURDAY WHICH THEN WEAKENS SATURDAY NIGHT AND THEN TRANSITIONS TO
WAA THEREAFTER. THE 850 MB TEMPERATURES ARE FORECAST TO BE NEAR
-12C SATURDAY BEFORE MODERATING, THEREFORE A MUCH COLDER DAY IS
EXPECTED. THE COMBINATION OF CAA AND A TIGHT PRESSURE GRADIENT WITH
STRONG HIGH PRESSURE TO OUR SOUTHWEST WILL RESULT IN BREEZY TO WINDY
CONDITIONS SATURDAY. THE FORECAST SOUNDINGS SHOW ABOUT 35 KNOTS OF
WIND IN THE MIXING LAYER, AND ATTM WE BUMPED THE GUSTS UP TO 30
KNOTS AT THE SURFACE. THE COMBINATION OF TEMPERATURES IN THE 30S AND
40S AND GUSTY WINDS WILL BRING COLD WIND CHILLS INTO THE PICTURE.
WHILE THIS COLD SHOT IS NOT VERY SIGNIFICANT FOR THIS TIME OF YEAR,
IT WILL BE A SHOCK GIVEN HOW WARM IT HAS BEEN THIS MONTH. IT LOOKS
LIKE PHILADELPHIA /THE AIRPORT/ SHOULD FINALLY GET BELOW 32 DEGREES
SATURDAY NIGHT.
THE COLD WEST TO NORTHWEST FLOW IS EXPECTED TO RESULT IN LAKE EFFECT
SNOW AND SOME OF THIS ACTIVITY SHOULD GET PULLED INTO NORTHEASTERN
PENNSYLVANIA SATURDAY, ALLOWING FOR SOME SNOW SHOWERS INTO AT LEAST
THE POCONOS. THERE COULD EVEN BE SOME FLURRIES FARTHER SOUTH AND
EAST, HOWEVER THE SUB-CLOUD LAYER /DEW POINTS DROPPING THROUGH THE
TEENS SATURDAY/ MAY BE TO DRY WITH A SOUTHERN EXTENT AND THEREFORE
DID NOT CARRY A MENTION TO FAR SOUTH AND EAST. IT IS POSSIBLE THAT A
SNOW SQUALL GETS TO THE POCONOS GIVEN THE INVERSION HEIGHT RISING
SOME AND THE LOW-LEVEL LAPSE RATES STEEPENING. HIGH PRESSURE THEN
BRIEFLY ARRIVES SUNDAY WITH LESS WIND AS THE UPPER-LEVEL TROUGH
LIFTS OUT, HOWEVER WE SHOULD START TO HAVE A RETURN FLOW BECOME
ESTABLISHED DURING SUNDAY AS THE UPPER-LEVEL FLOW IS PROGRESSIVE.
THIS ALLOWS FOR WAA TO OCCUR AND THEREFORE A REBOUND IN AFTERNOON
TEMPERATURES /MIXING WILL BE LESS THOUGH/.
FOR MONDAY THROUGH WEDNESDAY...AN UPPER-LEVEL RIDGE ACROSS THE EAST
WILL ALLOW FOR MILDER AIR, HOWEVER A SHORT WAVE TROUGH MAY SLIDE
NEARBY LATER MONDAY AND TUESDAY. THIS SHOULD SEND A WEAKENING COLD
FRONT TOWARD OUR AREA, HOWEVER IT MAY NOT COMPLETELY MAKE IT.
OVERALL A MILDER PATTERN IS EXPECTED AND THIS COULD RESULT IN NEAR
RECORD WARMTH STARTING WEDNESDAY. THERE IS MORE UNCERTAINTY HOWEVER
AS AT LEAST SOME MODEL GUIDANCE SHOWS A MORE ACTIVE FRONT TUESDAY
AND WEDNESDAY WITH SOME RIPPLES OF LOW PRESSURE ALONG IT. IF THIS
WERE TO OCCUR AND THEREFORE NOT KEEPING OUR AREA MORE INTO A CLEAN
WARM SECTOR, COOLER TEMPERATURES WILL RESULT /OUR SUPERBLEND TOOL IS
COOLER FOR WEDNESDAY/. WE OPTED TO LEAN CLOSER TO THE WPC GUIDANCE
ATTM WHICH FAVORS SOME SLOWNESS OF THE MAIN FRONT AS THE UPPER-LEVEL
FLOW COULD BE MORE AMPLIFIED AND THE SOUTHEAST RIDGE SHOULD PLAY A
ROLE.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY, AND SURROUNDING AREAS.
TODAY...RAIN IS MOVING IN RAPIDLY FROM THE SW DURING THE MORNING.
VFR OR MVFR CIGS TO START WITH. CONDITIONS WILL DETERIORATE TO
IFR DURING MID DAY IN RAIN WITH POTENTIAL FOR BRIEF LIFR CONDS IN
ST/FOG NEAR THE PATH OF THE LOW DURING THE AFTERNOON WHICH WOULD
BE PHILLY AREA. WINDS WILL BE FROM THE E TO SE BUT SHOULD REMAIN
GENLY LESS THAN 10 KT EXCEPT POSSIBLY GUST 20 KT KACY MIDDAY. A
COLD FRONT WILL CROSS THE AREA LATE IN THE DAY WITH AN ASSOCD WIND
SHIFT TO THE SOUTHWEST OR WEST BUT LIGHT.
TONIGHT...PATCHY IFR/LIFR CONDS IN ST/FOG DURING THE EVENING,
ESPECIALLY KPHL SEWD. ANY LEFTOVER SHOWERS SHOULD END BY 02Z
VCNTY KACY. CONDITIONS IMPROVE TO VFR CIGS AOA 5000 FT LATE AT
NIGHT. WIND BECOMING NORTHWEST AND GRADUALLY INCREASES OVERNIGHT
WITH VSBY IMPROVING CONSIDERABLY AFTER 05Z/18.
OUTLOOK...
FRIDAY...OVERALL VFR AS SOME CLEARING TAKES PLACE FROM WEST TO EAST.
NORTHWESTERLY WINDS 10-15 KNOTS AND GUSTY AT TIMES.
SATURDAY...VFR. WEST-NORTHWEST WINDS 15-20 KNOTS WITH GUSTS TO 30
KNOTS, DIMINISHING AT NIGHT AND BECOMING WEST-SOUTHWEST.
SUNDAY AND MONDAY...VFR OVERALL, ALTHOUGH A FEW SHOWERS ARE
POSSIBLE LATE MONDAY. SOUTH-SOUTHWEST WINDS NEAR 10 KNOTS.
&&
.MARINE...
NO CHANGES ON THE MID-MORNING UPDATE.
FIRST PERIOD SCA FOR THE COASTAL WATERS FROM LITTLE EGG INLET NJ
(VCNTY KACY) SOUTHWARD TO DE. EXPECTING DURING THE MIDDAY-EARLY
AFTERNOON HOURS A BRIEF PERIOD OF SOUTHEAST INFLOW GUSTS 20-25 KT
AND SEAS INCREASING TO NEAR 5 FT ON THE ATLC WATERS. THIS IS
ISSUED WITH LESS THAN 80 PCT CONFIDENCE OF OCCURRENCE BUT ITS
BASICALLY OFFERED WITH SOME LEAD TIME. THE HRRR HAS SOME DECENT
INFLOW WIND AROUND 17Z-20Z. USUALLY HRRR WINDS ARE A BIT OVERDONE
BUT IN THIS CASE, SHAVED 5 FT AND STILL GET 25 KT GUSTS.
OTRW...CONDS SHOULD REMAIN SUB-SCA THROUGH TODAY NNJ WATERS AS
WELL AS DELAWARE BAY.
FOG MAY BECOME A MARINE TRANSPORTATION HAZARD LATE THIS AFTERNOON?
TONIGHT...NO SCA ANTICIPATED IN DEVELOPING NORTHWEST FLOW FOR THE
NNJ AND DE BAY WATERS BUT THE SCA MAY STILL BE NEEDED FOR THE ATLC
WATERS OF S NJ AND DE WHERE SEAS WILL BE AROUND 5 FT. DENSE FOG
MAY BE A MARINE TRANSPORTATION FACTOR THIS EVENING.
OUTLOOK...
FRIDAY THROUGH SATURDAY NIGHT...STRONG CAA AND A TIGHTENING PRESSURE
GRADIENT WILL ALLOW THE MIXING TO DEEPEN. THIS WILL RESULT IN GUSTS
TO 30 KNOTS MAINLY STARTING FRIDAY EVENING, HOWEVER A PERIOD OF
GALE FORCE GUSTS MAY OCCUR FRIDAY NIGHT AND SATURDAY. A SMALL
CRAFT ADVISORY IS LIKELY AND A GALE WATCH IS POSSIBLE. THE WINDS
DIMINISH SOME BY LATE SATURDAY NIGHT.
SUNDAY...NORTHWEST WINDS ARE EXPECTED TO WEAKEN AND SHIFT TO
SOUTHWESTERLY, HOWEVER CONDITIONS MAY BE CLOSE TO SMALL CRAFT
ADVISORY CRITERIA FOR A TIME.
MONDAY...A SOUTHWESTERLY FLOW SHOULD GUST TO ABOUT 25 KNOTS, HOWEVER
THE AIRMASS IS WARMING AND THIS COULD REDUCE THE OVERALL MIXING.
&&
.CLIMATE...
**DECEMBERS RECORD WARMTH MAY BE REINFORCED WITH MORE DAILY RECORDS
TOWARD CHRISTMAS**
WE ARE BEGINNING THE PROCESS OF POSTING RECORD MAXIMUM TEMPERATURES
THAT MAY BE APPROACHED OR EXCEEDED, AS OUR FORECAST NUMBERS AND OR
MODEL OUTPUT STATISTICAL GUIDANCE (SOMETIMES REFERRED TO AS MOS OR
STAT GUIDE) APPROACH OR EXCEED THE RECORDS.
IF YOU REMEMBER, TEMPERATURES PEAKED GENERALLY IN THE 60S ON DECEMBER
24-25 LAST YEAR AND AROUND DECEMBER 21-23 2013 (60S) AS WELL.
RECORD DAILY MAX TEMPERATURES BELOW
12/23
ACY 65-1990
PHL 66-1990
ILG 66-1990
ABE 64-1990
TTN 70-1891
GED 68-2013 AND 1949
RDG 63-2007 AND 1990
MPO 58-1990
TEMPERATURES HAVE BEEN SO WARM THE FIRST 16 DAYS OF THE MONTH (9
TO 13 DEGREES ABOVE NORMAL) THAT IT WILL TAKE QUITE A SUBSTANTIAL
COLD SPELL TO PREVENT A RECORD WARM DECEMBER, AND THIS AFTER A TOP
8 WARMEST NOVEMBER ON RECORD. HOWEVER, WE SUGGEST NOT EXTRAPOLATING
THIS WARMTH FOR THE REST OF OUR WINTER.
GEFS AND EC ENSEMBLES ARE CONTINUING AN TO WARM US TO RECORD WARM
DAILY VALUES AGAIN TOWARD CHRISTMAS.
THEREAFTER, THE 00Z/17 GEFS CONTINUES A NOTABLE EAST COAST RIDGE!
FAST WESTERLY FLOW ACROSS THE NORTH ATLANTIC AND NO SIGN OF SUBSTANTIAL
RIDGING IN WESTERN NORTH AMERICA OR ANY DEPRESSED JET ACROSS THE
SOUTHERN USA ALL SUGGEST THAT BELOW NORMAL COLD IS NOT LIKELY HERE FOR
MORE THAN A DAY OR 2 (IF THAT), BETWEEN NOW AND THE NEW YEAR.
UNTIL SOMETHING WITHIN THAT OVERALL PATTERN CHANGES SUBSTANTIALLY,
WE WILL CONTINUE TO HOPEFULLY ENJOY GENERALLY ABNORMALLY MILD
WEATHER. THE LACK OF SNOW COVER ALSO CONTRIBUTES TO THE POSITIVE
DAILY DEPARTURE FROM CLIMATOLOGY.
PROJECTIONS EVALUATED WITH THIS MORNINGS 330 AM THURSDAY DECEMBER
17 FORECAST ARE EASILY 8 TO 11 DEGREES ABOVE NORMAL FOR THE
ENTIRE MONTH.
DECEMBER PROJECTED BELOW
ABE NORMAL DECEMBER AVERAGE TEMPERATURE IS 32.3. WE ARE EXPECTING AROUND
43.0. THAT WOULD BE THE WARMEST SINCE RECORDS BEGAN IN 1922, AND 3
DEGREES WARMER THAN THE PREVIOUS WARMEST, DECEMBER 1923, WHEN THE
AVERAGE WAS 40.0
PHL NORMAL DECEMBER AVERAGE TEMPERATURE IS 37.5. WE ARE EXPECTING
AROUND 47.0. THAT WOULD BE THE WARMEST SINCE TEMPERATURE RECORDS
BEGAN IN 1874 (PRECIP RECORDS BEGAN THERE IN 1872). AND THIS WOULD
BE ALMOST 3 DEGREES WARMER THAN THE PREVIOUS WARMEST DECEMBER
1923, WHEN THE AVERAGE WAS 44.5 DEGREES.
THESE VALUES WERE CALCULATED USING OUR PHI 09Z/17 FORECAST
THROUGH D7, THEN ADDING ON THE D8-11 TEMPS FROM THE 00Z/17
NMCFTPRHA (GFS 2M MAX/MIN TEMPS) AND FINALLY, FOR THE LAST 4 DAYS
OF THE MONTH, WE JUST USED STRAIGHT DAILY NORMALS FOR EACH
LOCATION.
THE NUMBERS ABOVE WILL VARY FROM CURRENTLY PROJECTED... AND WE COULD
SEE CHANGES OF 2 DEGREES EITHER WAY, BUT OVERALL WHEN ALL THE DAILIES
ARE AVERAGED... WE WILL PROBABLY EXPERIENCE OUR WARMEST DECEMBER ON
RECORD, THROUGH 2015. THE VALUES POSTED HERE MAY BE CONSERVATIVELY
TOO COOL.
PHL HAS NOT BEEN BELOW NORMAL SINCE NOV 24TH.
PHILADELPHIA`S FIRST SUBFREEZING TEMPERATURE OF THE COOL SEASON SHOULD
OCCUR SUNDAY MORNING...THE LAST DAY OF FALL (DEC 20), EASILY EXCEEDING
THE PREVIOUS LATEST SUBFREEZING DATE OF DECEMBER 12 1998. OFFICIAL
TEMPERATURE RECORDS FOR PHILADELPHIA DATE BACK TO 1874.
PORTIONS OF ALL OF THIS CLIMATE SECTION OF THE AFD WILL BE DISCONTINUED
LATER TODAY BUT WILL BE UPDATED AGAIN FRIDAY MORNING AND THEN AGAIN
ON CHRISTMAS DAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
ANZ452>455.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG/SZATKOWSKI
SHORT TERM...DRAG
LONG TERM...GORSE
AVIATION...DRAG/GORSE/SZATKOWSKI
MARINE...DRAG/GORSE/SZATKOWSKI
CLIMATE...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
655 AM EST THU DEC 17 2015
.SYNOPSIS...
LOW PRESSURE AND A COLD FRONT WILL MOVE ACROSS OUR AREA LATE TODAY
AND EARLY TONIGHT. A STRONG AREA OF HIGH PRESSURE BUILDS TO OUR SOUTH
AND WEST FRIDAY AND SATURDAY, THEN BRIEFLY SETTLES OVER OUR REGION
SUNDAY BEFORE MOVING OFFSHORE. A WEAK COLD FRONT WILL APPROACH ON
TUESDAY, HOWEVER IT MAY STALL JUST TO OUR WEST BEFORE ANOTHER COLD
FRONT APPROACHES LATE WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RAIN HAS BEEN POPPED PER HRRR ONSET 12Z-15Z E PA THIS MORNING...
DELAYED SLIGHTLY FROM EARLIER FORECASTS THEN ROBUST 3-6 HR PERIOD
OF SHOWERY RAINS MIDDAY/MID AFTN EVERYWHERE.
SOME OF THE RAIN WILL BE BRIEFLY HEAVY NEAR THE PATH OF THE SFC
LOW IN THE SLIGHTLY MORE UNSTABLE AIR AND THAT SHOULD BE NJ/DE AS
PER THE WPC QPF. MOST OF THE RAIN IN THE 15Z-22Z TIME FRAME.
QPF GENERALLY .3 TO .8 INCHES WITH A FEW 1.25 INCH AMOUNTS
POSSIBLE, ESPECIALLY NJ/DE. HWO FB AND TWEET HAS THE HEAVY RAIN
HAZARD.
SE WIND BRIEFLY INCREASES DURING MIDDAY WITH GUSTS 20 MPH S NJ
COAST AS WELL AS DELAWARE, WHILE THE WIND IN E PA MAY TURN LIGHT
NE. A WIND SHIFT EVERYWHERE TO SOUTHWEST OR WEST LATE IN THE DAY
WITH LOW PRES AND A BROAD CFP PASSING THROUGH AND THEN EAST OF OUR
COASTS.
FOG IN THE FORECAST THIS AFTN IN THE BROAD PATH OF LOW PRES AND A
WEAK GRADIENT, ESPECIALLY SUNSET ONWARD WHEN DRY SLOT PASSES THROUGH
ALOFT. SOME OF THAT FOG COULD BE DENSE AND FORESEE A SPS POTENTIAL
FOR FOG LATE IN THE DAY.
FORECAST ELEMENTS WERE DERIVED FROM A 50 50 BLEND OF THE 00Z/17
GFS/NAM MOS. HOWEVER, BECAUSE OF WETBULBING AND RAIN, I BLENDED
THE TEMPS WITH THE COOLER NAM 2 M TEMPS. CONFIDENCE ON LOWERING
TEMPS FROM GUIDANCE I-95 NWWD IS ONLY AVERAGE.
AS FOR CLIMO...MAX TEMPS ABOUT 10F ABOVE NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
PROBABLY PATCHY FOG, POSSIBLY DENSE ALONG AND SE OF I-95 DURING THE
EVENING. LEFTOVER SHOWERS ALONG THE COASTS DURING THE EVENING.
DOUBTING IF ANY MEASURABLE RAIN AFTER MIDNIGHT. OTRW...MO CLOUDY.
WIND BECOMING NORTHWEST AND INCREASING AFTER MIDNIGHT WHEN THE
DEWPOINTS TUMBLE AND VSBY IMPROVES CONSIDERABLY.
FORECAST ELEMENTS WERE DERIVED FROM A 50 50 BLEND OF THE 00Z/17
GFS/NAM MOS.
CLIMO: LOWS ABOUT 15F WARMER THAN NORMAL.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF AN AMPLIFIED UPPER-LEVEL TROUGH
SETTLING INTO THE EAST FRIDAY NIGHT AND SATURDAY BEFORE LIFTING
NORTHEASTWARD SUNDAY. THIS DELIVERS MUCH COLDER AIR INTO THE EAST,
HOWEVER THE FLOW IS PROGRESSIVE AND THEREFORE THE COLD SHOT IS SHORT
IN DURATION. AS ENERGY ACROSS THE WEST MOVES INTO THE CENTRAL PLAINS
LATER IN THE WEEKEND, RIDGING RETURNS ACROSS THE EAST. THIS WILL
ALLOW A WARMING TREND TO OCCUR NEXT WEEK, WITH POTENTIALLY NEAR
RECORD WARMTH STARTING ON WEDNESDAY. THE MAIN WEATHER FEATURE IS A
FRONTAL ZONE WITH WAVES OF LOW PRESSURE ALONG IT OFFSHORE FRIDAY
NIGHT, THEN A POTENTIALLY SLOW MOVING FRONT ARRIVING TUESDAY INTO
THURSDAY. WE USED A MODEL BLEND FRIDAY THROUGH SUNDAY, THEN A 00Z
WPC/CONTINUITY BLEND THEREAFTER. SOME ADJUSTMENTS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.
FOR FRIDAY...THERE SHOULD BE GRADUAL CLEARING AS THE FRONT AND
SURFACE WAVE IS OFFSHORE, HOWEVER SOME OVERRUNNING WEST OF THE
BOUNDARY AS ANOTHER LOW RUNS UP THE FRONT COULD LINGER SOME SHOWERS
NEAR THE COAST IN THE MORNING. OVERALL THOUGH THE BULK OF THE
PRECIPITATION SHOULD REMAIN OFFSHORE, THEREFORE HELD ONTO SOME
SLIGHT CHC TO LOW CHC POPS IN THE MORNING MAINLY FROM THE COAST ON
EASTWARD. CAA ARRIVES THROUGH THE DAY AND REALLY KICKS IN BY LATE IN
THE DAY. THERE IS THE POTENTIAL FOR SOME FLURRIES OR SNOW SHOWERS
GETTING TO THE POCONOS LATER AT NIGHT AS A MUCH COLDER AIRMASS TURNS
THE LAKE EFFECT MACHINE ON. WE ARE ANTICIPATING A BREEZE, WHICH MAY
INCREASE SOME AS THE CAA DEEPENS AND THE PRESSURE GRADIENT TIGHTENS.
FOR SATURDAY AND SUNDAY...A STRONG UPPER-LEVEL TROUGH SWINGS ACROSS
THE EAST SATURDAY BEFORE LIFTING NORTHEASTWARD SUNDAY. THIS FEATURE
WILL HAVE MUCH COLDER AIR WITH IT, WITH STRONG CAA OCCURRING
SATURDAY WHICH THEN WEAKENS SATURDAY NIGHT AND THEN TRANSITIONS TO
WAA THEREAFTER. THE 850 MB TEMPERATURES ARE FORECAST TO BE NEAR
-12C SATURDAY BEFORE MODERATING, THEREFORE A MUCH COLDER DAY IS
EXPECTED. THE COMBINATION OF CAA AND A TIGHT PRESSURE GRADIENT WITH
STRONG HIGH PRESSURE TO OUR SOUTHWEST WILL RESULT IN BREEZY TO WINDY
CONDITIONS SATURDAY. THE FORECAST SOUNDINGS SHOW ABOUT 35 KNOTS OF
WIND IN THE MIXING LAYER, AND ATTM WE BUMPED THE GUSTS UP TO 30
KNOTS AT THE SURFACE. THE COMBINATION OF TEMPERATURES IN THE 30S AND
40S AND GUSTY WINDS WILL BRING COLD WIND CHILLS INTO THE PICTURE.
WHILE THIS COLD SHOT IS NOT VERY SIGNIFICANT FOR THIS TIME OF YEAR,
IT WILL BE A SHOCK GIVEN HOW WARM IT HAS BEEN THIS MONTH. IT LOOKS
LIKE PHILADELPHIA /THE AIRPORT/ SHOULD FINALLY GET BELOW 32 DEGREES
SATURDAY NIGHT.
THE COLD WEST TO NORTHWEST FLOW IS EXPECTED TO RESULT IN LAKE EFFECT
SNOW AND SOME OF THIS ACTIVITY SHOULD GET PULLED INTO NORTHEASTERN
PENNSYLVANIA SATURDAY, ALLOWING FOR SOME SNOW SHOWERS INTO AT LEAST
THE POCONOS. THERE COULD EVEN BE SOME FLURRIES FARTHER SOUTH AND
EAST, HOWEVER THE SUB-CLOUD LAYER /DEW POINTS DROPPING THROUGH THE
TEENS SATURDAY/ MAY BE TO DRY WITH A SOUTHERN EXTENT AND THEREFORE
DID NOT CARRY A MENTION TO FAR SOUTH AND EAST. IT IS POSSIBLE THAT A
SNOW SQUALL GETS TO THE POCONOS GIVEN THE INVERSION HEIGHT RISING
SOME AND THE LOW-LEVEL LAPSE RATES STEEPENING. HIGH PRESSURE THEN
BRIEFLY ARRIVES SUNDAY WITH LESS WIND AS THE UPPER-LEVEL TROUGH
LIFTS OUT, HOWEVER WE SHOULD START TO HAVE A RETURN FLOW BECOME
ESTABLISHED DURING SUNDAY AS THE UPPER-LEVEL FLOW IS PROGRESSIVE.
THIS ALLOWS FOR WAA TO OCCUR AND THEREFORE A REBOUND IN AFTERNOON
TEMPERATURES /MIXING WILL BE LESS THOUGH/.
FOR MONDAY THROUGH WEDNESDAY...AN UPPER-LEVEL RIDGE ACROSS THE EAST
WILL ALLOW FOR MILDER AIR, HOWEVER A SHORT WAVE TROUGH MAY SLIDE
NEARBY LATER MONDAY AND TUESDAY. THIS SHOULD SEND A WEAKENING COLD
FRONT TOWARD OUR AREA, HOWEVER IT MAY NOT COMPLETELY MAKE IT.
OVERALL A MILDER PATTERN IS EXPECTED AND THIS COULD RESULT IN NEAR
RECORD WARMTH STARTING WEDNESDAY. THERE IS MORE UNCERTAINTY HOWEVER
AS AT LEAST SOME MODEL GUIDANCE SHOWS A MORE ACTIVE FRONT TUESDAY
AND WEDNESDAY WITH SOME RIPPLES OF LOW PRESSURE ALONG IT. IF THIS
WERE TO OCCUR AND THEREFORE NOT KEEPING OUR AREA MORE INTO A CLEAN
WARM SECTOR, COOLER TEMPERATURES WILL RESULT /OUR SUPERBLEND TOOL IS
COOLER FOR WEDNESDAY/. WE OPTED TO LEAN CLOSER TO THE WPC GUIDANCE
ATTM WHICH FAVORS SOME SLOWNESS OF THE MAIN FRONT AS THE UPPER-LEVEL
FLOW COULD BE MORE AMPLIFIED AND THE SOUTHEAST RIDGE SHOULD PLAY A
ROLE.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY, AND SURROUNDING AREAS.
TODAY...RAIN WILL MOVE IN RAPIDLY FROM THE SW DURING THE MORNING. VFR
OR MVFR CIGS TO START WITH THE IFR VCNTY KTTN PROBABLY DISSIPATING
BY 14Z. CONDITIONS WILL DETERIORATE TO IFR DURING MID DAY IN RAIN
WITH POTENTIAL FOR BRIEF LIFR CONDS IN ST/FOG NEAR THE PATH OF THE
LOW DURING THE AFTERNOON WHICH WOULD BE PHILLY AREA. WINDS WILL BE
FROM THE E TO SE BUT SHOULD REMAIN GENLY LESS THAN 10 KT EXCEPT
POSSIBLY GUST 20 KT KACY MIDDAY. A COLD FRONT WILL CROSS THE AREA
LATE IN THE DAY WITH AN ASSOCD WIND SHIFT TO THE SOUTHWEST OR WEST
BUT LIGHT.
TONIGHT...PATCHY IFR/LIFR CONDS IN ST/FOG DURING THE EVENING,
ESPECIALLY KPHL SEWD. ANY LEFTOVER SHOWERS SHOULD END BY 02Z
VCNTY KACY. CONDITIONS IMPROVE TO VFR CIGS AOA 5000 FT LATE AT
NIGHT. WIND BECOMING NORTHWEST AND GRADUALLY INCREASES OVERNIGHT
WITH VSBY IMPROVING CONSIDERABLY AFTER 05Z/18.
OUTLOOK...
FRIDAY...OVERALL VFR AS SOME CLEARING TAKES PLACE FROM WEST TO EAST.
NORTHWESTERLY WINDS 10-15 KNOTS AND GUSTY AT TIMES.
SATURDAY...VFR. WEST-NORTHWEST WINDS 15-20 KNOTS WITH GUSTS TO 30
KNOTS, DIMINISHING AT NIGHT AND BECOMING WEST-SOUTHWEST.
SUNDAY AND MONDAY...VFR OVERALL, ALTHOUGH A FEW SHOWERS ARE
POSSIBLE LATE MONDAY. SOUTH-SOUTHWEST WINDS NEAR 10 KNOTS.
&&
.MARINE...
FIRST PERIOD SCA FOR THE COASTAL WATERS FROM LITTLE EGG INLET NJ
(VCNTY KACY) SOUTHWARD TO DE. EXPECTING DURING THE MIDDAY-EARLY
AFTERNOON HOURS A BRIEF PERIOD OF SOUTHEAST INFLOW GUSTS 20-25 KT
AND SEAS INCREASING TO NEAR 5 FT ON THE ATLC WATERS. THIS IS
ISSUED WITH LESS THAN 80 PCT CONFIDENCE OF OCCURRENCE BUT ITS
BASICALLY OFFERED WITH SOME LEAD TIME. THE HRRR HAS SOME DECENT
INFLOW WIND AROUND 17Z-20Z. USUALLY HRRR WINDS ARE A BIT OVERDONE
BUT IN THIS CASE, SHAVED 5 FT AND STILL GET 25 KT GUSTS.
OTRW...CONDS SHOULD REMAIN SUB-SCA THROUGH TODAY NNJ WATERS AS
WELL AS DELAWARE BAY.
FOG MAY BECOME A MARINE TRANSPORTATION HAZARD LATE THIS AFTERNOON?
TONIGHT...NO SCA ANTICIPATED IN DEVELOPING NORTHWEST FLOW FOR THE
NNJ AND DE BAY WATERS BUT THE SCA MAY STILL BE NEEDED FOR THE ATLC
WATERS OF S NJ AND DE WHERE SEAS WILL BE AROUND 5 FT. DENSE FOG
MAY BE A MARINE TRANSPORTATION FACTOR THIS EVENING.
OUTLOOK...
FRIDAY THROUGH SATURDAY NIGHT...STRONG CAA AND A TIGHTENING PRESSURE
GRADIENT WILL ALLOW THE MIXING TO DEEPEN. THIS WILL RESULT IN GUSTS
TO 30 KNOTS MAINLY STARTING FRIDAY EVENING, HOWEVER A PERIOD OF
GALE FORCE GUSTS MAY OCCUR FRIDAY NIGHT AND SATURDAY. A SMALL
CRAFT ADVISORY IS LIKELY AND A GALE WATCH IS POSSIBLE. THE WINDS
DIMINISH SOME BY LATE SATURDAY NIGHT.
SUNDAY...NORTHWEST WINDS ARE EXPECTED TO WEAKEN AND SHIFT TO
SOUTHWESTERLY, HOWEVER CONDITIONS MAY BE CLOSE TO SMALL CRAFT
ADVISORY CRITERIA FOR A TIME.
MONDAY...A SOUTHWESTERLY FLOW SHOULD GUST TO ABOUT 25 KNOTS, HOWEVER
THE AIRMASS IS WARMING AND THIS COULD REDUCE THE OVERALL MIXING.
&&
.CLIMATE...
**DECEMBERS RECORD WARMTH MAY BE REINFORCED WITH MORE DAILY RECORDS
TOWARD CHRISTMAS**
WE ARE BEGINNING THE PROCESS OF POSTING RECORD MAXIMUM TEMPERATURES
THAT MAY BE APPROACHED OR EXCEEDED, AS OUR FORECAST NUMBERS AND OR
MODEL OUTPUT STATISTICAL GUIDANCE (SOMETIMES REFERRED TO AS MOS OR
STAT GUIDE) APPROACH OR EXCEED THE RECORDS.
IF YOU REMEMBER, TEMPERATURES PEAKED GENERALLY IN THE 60S ON DECEMBER
24-25 LAST YEAR AND AROUND DECEMBER 21-23 2013 (60S) AS WELL.
RECORD DAILY MAX TEMPERATURES BELOW
12/23
ACY 65-1990
PHL 66-1990
ILG 66-1990
ABE 64-1990
TTN 70-1891
GED 68-2013 AND 1949
RDG 63-2007 AND 1990
MPO 58-1990
TEMPERATURES HAVE BEEN SO WARM THE FIRST 16 DAYS OF THE MONTH (9
TO 13 DEGREES ABOVE NORMAL) THAT IT WILL TAKE QUITE A SUBSTANTIAL
COLD SPELL TO PREVENT A RECORD WARM DECEMBER, AND THIS AFTER A TOP
8 WARMEST NOVEMBER ON RECORD. HOWEVER, WE SUGGEST NOT EXTRAPOLATING
THIS WARMTH FOR THE REST OF OUR WINTER.
GEFS AND EC ENSEMBLES ARE CONTINUING AN TO WARM US TO RECORD WARM
DAILY VALUES AGAIN TOWARD CHRISTMAS.
THEREAFTER, THE 00Z/17 GEFS CONTINUES A NOTABLE EAST COAST RIDGE!
FAST WESTERLY FLOW ACROSS THE NORTH ATLANTIC AND NO SIGN OF SUBSTANTIAL
RIDGING IN WESTERN NORTH AMERICA OR ANY DEPRESSED JET ACROSS THE
SOUTHERN USA ALL SUGGEST THAT BELOW NORMAL COLD IS NOT LIKELY HERE FOR
MORE THAN A DAY OR 2 (IF THAT), BETWEEN NOW AND THE NEW YEAR.
UNTIL SOMETHING WITHIN THAT OVERALL PATTERN CHANGES SUBSTANTIALLY,
WE WILL CONTINUE TO HOPEFULLY ENJOY GENERALLY ABNORMALLY MILD
WEATHER. THE LACK OF SNOW COVER ALSO CONTRIBUTES TO THE POSITIVE
DAILY DEPARTURE FROM CLIMATOLOGY.
PROJECTIONS EVALUATED WITH THIS MORNINGS 330 AM THURSDAY DECEMBER
17 FORECAST ARE EASILY 8 TO 11 DEGREES ABOVE NORMAL FOR THE
ENTIRE MONTH.
DECEMBER PROJECTED BELOW
ABE NORMAL DECEMBER AVERAGE TEMPERATURE IS 32.3. WE ARE EXPECTING AROUND
43.0. THAT WOULD BE THE WARMEST SINCE RECORDS BEGAN IN 1922, AND 3
DEGREES WARMER THAN THE PREVIOUS WARMEST, DECEMBER 1923, WHEN THE
AVERAGE WAS 40.0
PHL NORMAL DECEMBER AVERAGE TEMPERATURE IS 37.5. WE ARE EXPECTING
AROUND 47.0. THAT WOULD BE THE WARMEST SINCE TEMPERATURE RECORDS
BEGAN IN 1874 (PRECIP RECORDS BEGAN THERE IN 1872). AND THIS WOULD
BE ALMOST 3 DEGREES WARMER THAN THE PREVIOUS WARMEST DECEMBER
1923, WHEN THE AVERAGE WAS 44.5 DEGREES.
THESE VALUES WERE CALCULATED USING OUR PHI 09Z/17 FORECAST
THROUGH D7, THEN ADDING ON THE D8-11 TEMPS FROM THE 00Z/17
NMCFTPRHA (GFS 2M MAX/MIN TEMPS) AND FINALLY, FOR THE LAST 4 DAYS
OF THE MONTH, WE JUST USED STRAIGHT DAILY NORMALS FOR EACH
LOCATION.
THE NUMBERS ABOVE WILL VARY FROM CURRENTLY PROJECTED... AND WE COULD
SEE CHANGES OF 2 DEGREES EITHER WAY, BUT OVERALL WHEN ALL THE DAILIES
ARE AVERAGED... WE WILL PROBABLY EXPERIENCE OUR WARMEST DECEMBER ON
RECORD, THROUGH 2015. THE VALUES POSTED HERE MAY BE CONSERVATIVELY
TOO COOL.
PHL HAS NOT BEEN BELOW NORMAL SINCE NOV 24TH.
PHILADELPHIA`S FIRST SUBFREEZING TEMPERATURE OF THE COOL SEASON SHOULD
OCCUR SUNDAY MORNING...THE LAST DAY OF FALL (DEC 20), EASILY EXCEEDING
THE PREVIOUS LATEST SUBFREEZING DATE OF DECEMBER 12 1998. OFFICIAL
TEMPERATURE RECORDS FOR PHILADELPHIA DATE BACK TO 1874.
PORTIONS OF ALL OF THIS CLIMATE SECTION OF THE AFD WILL BE DISCONTINUED
LATER TODAY BUT WILL BE UPDATED AGAIN FRIDAY MORNING AND THEN AGAIN
ON CHRISTMAS DAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 PM EST THIS
AFTERNOON FOR ANZ452>455.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG 655
SHORT TERM...DRAG 655
LONG TERM...GORSE
AVIATION...DRAG/GORSE 655
MARINE...DRAG/GORSE 655
CLIMATE...655
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
531 AM EST THU DEC 17 2015
.SYNOPSIS...
LOW PRESSURE AND A COLD FRONT WILL MOVE ACROSS OUR AREA LATE TODAY
AND EARLY TONIGHT. A STRONG AREA OF HIGH PRESSURE BUILDS TO OUR
SOUTH AND WEST FRIDAY AND SATURDAY, THEN BRIEFLY SETTLES OVER OUR
REGION SUNDAY BEFORE MOVING OFFSHORE. A WEAK COLD FRONT WILL
APPROACH ON TUESDAY, HOWEVER IT MAY STALL JUST TO OUR WEST BEFORE
ANOTHER COLD FRONT APPROACHES LATE WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DRY EARLY THIS MORNING. FOG SHOULD DEVELOP POCONOS AROUND 12Z.
RAIN HAS BEEN POPPED PER HRRR ONSET 12Z-15Z E PA THIS MORNING...
DELAYED SLIGHTLY FROM EARLIER FORECASTS THEN ROBUST 3-6 HR PERIOD
OF SHOWERY RAINS MIDDAY/MID AFTN EVERYWHERE.
SOME OF THE RAIN WILL BE BRIEFLY HEAVY NEAR THE PATH OF THE SFC
LOW IN THE SLIGHTLY MORE UNSTABLE AIR AND THAT SHOULD BE NJ/DE AS
PER THE WPC QPF. MOST OF THE RAIN IN THE 15Z- 22Z TIME FRAME. SE
WIND BRIEFLY INCREASES DURING MIDDAY WITH GUSTS 20 MPH S NJ COAST
AS WELL AS DELAWARE, WHILE THE WIND IN E PA MAY TURN LIGHT NE. A
WIND SHIFT EVERYWHERE TO SOUTHWEST OR WEST LATE IN THE DAY WITH
LOW PRES AND A BROAD CFP PASSING THROUGH AND THEN EAST OF OUR
COASTS.
HAVE ADDED FOG TO THE FORECAST THIS AFTN IN THE BROAD PATH OF LOW
PRES GRADIENT, ESPECIALLY SUNSET ONWARD WHEN DRY SLOT PASSES
THROUGH ALOFT. SOME OF THAT FOG COULD BE DENSE AND FORESEE A SPS
POTENTIAL FOR FOG LATE IN THE DAY.
FORECAST ELEMENTS WERE DERIVED FROM A 50 50 BLEND OF THE 00Z/17
GFS/NAM MOS. HOWEVER, BECAUSE OF WETBULBING AND RAIN, I BLENDED
THE TEMPS WITH THE COOLER NAM 2 M TEMPS.
AS FOR CLIMO...AM SO USED TO THIS WONDERFUL WONDERFUL WEATHERWE`VE
ENJOYED THIS UNUSUALLY WARM NOVEMBER-DECEMBER THAT I NEGLECT TO
MENTION...MAX TEMPS ABOUT 10F ABOVE NORMAL, AS IF THIS ISN`T
SPECIAL IN OUR NECK OF THE WOODS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
PROBABLY PATCHY FOG, POSSIBLY DENSE ALONG AND SE OF I-95 DURING THE
EVENING. LEFTOVER SHOWERS ALONG THE COASTS DURING THE EVENING.
DOUBTING IF ANY MEASURABLE RAIN AFTER MIDNIGHT. OTRW...MO CLOUDY.
WIND BECOMING NORTHWEST AND INCREASING AFTER MIDNIGHT WHEN THE
DEWPOINTS TUMBLE AND VSBY IMPROVES CONSIDERABLY.
FORECAST ELEMENTS WERE DERIVED FROM A 50 50 BLEND OF THE 00Z/17
GFS/NAM MOS.
CLIMO: LOWS ABOUT 15F WARMER THAN NORMAL.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF AN AMPLIFIED UPPER-LEVEL TROUGH
SETTLING INTO THE EAST FRIDAY NIGHT AND SATURDAY BEFORE LIFTING
NORTHEASTWARD SUNDAY. THIS DELIVERS MUCH COLDER AIR INTO THE EAST,
HOWEVER THE FLOW IS PROGRESSIVE AND THEREFORE THE COLD SHOT IS SHORT
IN DURATION. AS ENERGY ACROSS THE WEST MOVES INTO THE CENTRAL PLAINS
LATER IN THE WEEKEND, RIDGING RETURNS ACROSS THE EAST. THIS WILL
ALLOW A WARMING TREND TO OCCUR NEXT WEEK, WITH POTENTIALLY NEAR
RECORD WARMTH STARTING ON WEDNESDAY. THE MAIN WEATHER FEATURE IS A
FRONTAL ZONE WITH WAVES OF LOW PRESSURE ALONG IT OFFSHORE FRIDAY
NIGHT, THEN A POTENTIALLY SLOW MOVING FRONT ARRIVING TUESDAY INTO
THURSDAY. WE USED A MODEL BLEND FRIDAY THROUGH SUNDAY, THEN A 00Z
WPC/CONTINUITY BLEND THEREAFTER. SOME ADJUSTMENTS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.
FOR FRIDAY...THERE SHOULD BE GRADUAL CLEARING AS THE FRONT AND
SURFACE WAVE IS OFFSHORE, HOWEVER SOME OVERRUNNING WEST OF THE
BOUNDARY AS ANOTHER LOW RUNS UP THE FRONT COULD LINGER SOME SHOWERS
NEAR THE COAST IN THE MORNING. OVERALL THOUGH THE BULK OF THE
PRECIPITATION SHOULD REMAIN OFFSHORE, THEREFORE HELD ONTO SOME
SLIGHT CHC TO LOW CHC POPS IN THE MORNING MAINLY FROM THE COAST ON
EASTWARD. CAA ARRIVES THROUGH THE DAY AND REALLY KICKS IN BY LATE IN
THE DAY. THERE IS THE POTENTIAL FOR SOME FLURRIES OR SNOW SHOWERS
GETTING TO THE POCONOS LATER AT NIGHT AS A MUCH COLDER AIRMASS TURNS
THE LAKE EFFECT MACHINE ON. WE ARE ANTICIPATING A BREEZE, WHICH MAY
INCREASE SOME AS THE CAA DEEPENS AND THE PRESSURE GRADIENT TIGHTENS.
FOR SATURDAY AND SUNDAY...A STRONG UPPER-LEVEL TROUGH SWINGS ACROSS
THE EAST SATURDAY BEFORE LIFTING NORTHEASTWARD SUNDAY. THIS FEATURE
WILL HAVE MUCH COLDER AIR WITH IT, WITH STRONG CAA OCCURRING
SATURDAY WHICH THEN WEAKENS SATURDAY NIGHT AND THEN TRANSITIONS TO
WAA THEREAFTER. THE 850 MB TEMPERATURES ARE FORECAST TO BE NEAR
-12C SATURDAY BEFORE MODERATING, THEREFORE A MUCH COLDER DAY IS
EXPECTED. THE COMBINATION OF CAA AND A TIGHT PRESSURE GRADIENT WITH
STRONG HIGH PRESSURE TO OUR SOUTHWEST WILL RESULT IN BREEZY TO WINDY
CONDITIONS SATURDAY. THE FORECAST SOUNDINGS SHOW ABOUT 35 KNOTS OF
WIND IN THE MIXING LAYER, AND ATTM WE BUMPED THE GUSTS UP TO 30
KNOTS AT THE SURFACE. THE COMBINATION OF TEMPERATURES IN THE 30S AND
40S AND GUSTY WINDS WILL BRING COLD WIND CHILLS INTO THE PICTURE.
WHILE THIS COLD SHOT IS NOT VERY SIGNIFICANT FOR THIS TIME OF YEAR,
IT WILL BE A SHOCK GIVEN HOW WARM IT HAS BEEN THIS MONTH. IT LOOKS
LIKE PHILADELPHIA /THE AIRPORT/ SHOULD FINALLY GET BELOW 32 DEGREES
SATURDAY NIGHT.
THE COLD WEST TO NORTHWEST FLOW IS EXPECTED TO RESULT IN LAKE EFFECT
SNOW AND SOME OF THIS ACTIVITY SHOULD GET PULLED INTO NORTHEASTERN
PENNSYLVANIA SATURDAY, ALLOWING FOR SOME SNOW SHOWERS INTO AT LEAST
THE POCONOS. THERE COULD EVEN BE SOME FLURRIES FARTHER SOUTH AND
EAST, HOWEVER THE SUB-CLOUD LAYER /DEW POINTS DROPPING THROUGH THE
TEENS SATURDAY/ MAY BE TO DRY WITH A SOUTHERN EXTENT AND THEREFORE
DID NOT CARRY A MENTION TO FAR SOUTH AND EAST. IT IS POSSIBLE THAT A
SNOW SQUALL GETS TO THE POCONOS GIVEN THE INVERSION HEIGHT RISING
SOME AND THE LOW-LEVEL LAPSE RATES STEEPENING. HIGH PRESSURE THEN
BRIEFLY ARRIVES SUNDAY WITH LESS WIND AS THE UPPER-LEVEL TROUGH
LIFTS OUT, HOWEVER WE SHOULD START TO HAVE A RETURN FLOW BECOME
ESTABLISHED DURING SUNDAY AS THE UPPER-LEVEL FLOW IS PROGRESSIVE.
THIS ALLOWS FOR WAA TO OCCUR AND THEREFORE A REBOUND IN AFTERNOON
TEMPERATURES /MIXING WILL BE LESS THOUGH/.
FOR MONDAY THROUGH WEDNESDAY...AN UPPER-LEVEL RIDGE ACROSS THE EAST
WILL ALLOW FOR MILDER AIR, HOWEVER A SHORT WAVE TROUGH MAY SLIDE
NEARBY LATER MONDAY AND TUESDAY. THIS SHOULD SEND A WEAKENING COLD
FRONT TOWARD OUR AREA, HOWEVER IT MAY NOT COMPLETELY MAKE IT.
OVERALL A MILDER PATTERN IS EXPECTED AND THIS COULD RESULT IN NEAR
RECORD WARMTH STARTING WEDNESDAY. THERE IS MORE UNCERTAINTY HOWEVER
AS AT LEAST SOME MODEL GUIDANCE SHOWS A MORE ACTIVE FRONT TUESDAY
AND WEDNESDAY WITH SOME RIPPLES OF LOW PRESSURE ALONG IT. IF THIS
WERE TO OCCUR AND THEREFORE NOT KEEPING OUR AREA MORE INTO A CLEAN
WARM SECTOR, COOLER TEMPERATURES WILL RESULT /OUR SUPERBLEND TOOL IS
COOLER FOR WEDNESDAY/. WE OPTED TO LEAN CLOSER TO THE WPC GUIDANCE
ATTM WHICH FAVORS SOME SLOWNESS OF THE MAIN FRONT AS THE UPPER-LEVEL
FLOW COULD BE MORE AMPLIFIED AND THE SOUTHEAST RIDGE SHOULD PLAY A
ROLE.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY, AND SURROUNDING AREAS.
EARLY THIS MORNING PRIOR TO 12Z...MVFR CEILINGS N OF KPHL WHILE
ITS TEMPO VFR CIGS ELSEWHERE AS MID DECK CLOUDINESS ARRIVES
DELMARVA AND S NJ. LIGHT WIND.
TODAY AFTER 12Z...RAIN WILL MOVE IN RAPIDLY FROM THE SW DURING THE
MORNING. CONDS MAY BE LOWER-END MVFR BY THE TIME THE RAIN STARTS
AND WILL LIKELY DETERIORATE FURTHER FROM THERE INTO THE IFR RANGE
BY MID DAY WITH POTENTIAL FOR BRIEF LIFR CONDS IN ST/FOG NEAR THE
PATH OF THE LOW DURING THE AFTERNOON WHICH WOULD BE PHILLY AREA.
WINDS WILL BE FROM THE E TO SE BUT SHOULD REMAIN GENLY LESS THAN
10 KT EXCEPT POSSIBLY GUST 20 KT KACY MIDDAY. A COLD FRONT WILL
CROSS THE AREA LATE IN THE DAY WITH AN ASSOCD WIND SHIFT TO THE
SOUTHWEST OR WEST BUT LIGHT.
TONIGHT...PATCHY IFR/LIFR CONDS IN ST/FOG DURING THE EVENING,
ESPECIALLY KPHL SEWD. ANY LEFTOVER SHOWERS SHOULD END BY 02Z
VCNTY KACY. CONDITIONS IMPROVE TO VFR CIGS AOA 5000 FT LATE AT
NIGHT. WIND BECOMING NORTHWEST AND GRADUALLY INCREASES OVERNIGHT
WITH VSBY IMPROVING CONSIDERABLY AFTER 05Z/18.
OUTLOOK...
FRIDAY...OVERALL VFR AS SOME CLEARING TAKES PLACE FROM WEST TO EAST.
NORTHWESTERLY WINDS 10-15 KNOTS AND GUSTY AT TIMES.
SATURDAY...VFR. WEST-NORTHWEST WINDS 15-20 KNOTS WITH GUSTS TO 30
KNOTS, DIMINISHING AT NIGHT AND BECOMING WEST-SOUTHWEST.
SUNDAY AND MONDAY...VFR OVERALL, ALTHOUGH A FEW SHOWERS ARE
POSSIBLE LATE MONDAY. SOUTH-SOUTHWEST WINDS NEAR 10 KNOTS.
&&
.MARINE...
ISSUING A FIRST PERIOD SCA FOR THE COASTAL WATERS OF LITTLE EGG
INLET NJ (VCNTY KACY) SOUTHWARD TO DE IN THE MIDDAY-AFTERNOON HOURS
FOR BRIEF INFLOW GUST 20-25 KT AND SEAS RISING TO NEAR 5 FT ON THE
ATLC WATERS. THIS IS ISSUED WITH LESS THAN 80 PCT CONFIDENCE OF
OCCURRENCE BUT ITS BASICALLY OFFERED AS SOME LEAD TIME. THE HRRR
HAS SOME DECENT INFLOW WIND AROUND 17Z-20Z. USUALLY HRRR WINDS ARE
A BIT OVERDONE BUT IN THIS CASE, SHAVED 5 FT AND STILL GET 25 KT
GUSTS.
OTRW...CONDS SHOULD REMAIN SUB-SCA THROUGH TODAY NNJ WATERS AS
WELL AS DELAWARE BAY.
FOG MAY BECOME A MARINE TRANSPORTATION HAZARD LATE THIS AFTERNOON?
TONIGHT...NO SCA ANTICIPATED IN DEVELOPING NORTHWEST FLOW FOR THE
NNJ AND DE BAY WATERS BUT THE SCA MAY STILL BE NEEDED FOR THE ATLC
WATERS OF S NJ AND DE WHERE SEAS WILL BE AROUND 5 FT. DENSE FOG
MAY BE A MARINE TRANSPORTATION FACTOR THIS EVENING.
OUTLOOK...
FRIDAY THROUGH SATURDAY NIGHT...STRONG CAA AND A TIGHTENING PRESSURE
GRADIENT WILL ALLOW THE MIXING TO DEEPEN. THIS WILL RESULT IN GUSTS
TO 30 KNOTS MAINLY STARTING FRIDAY EVENING, HOWEVER A PERIOD OF
GALE FORCE GUSTS MAY OCCUR FRIDAY NIGHT AND SATURDAY. A SMALL
CRAFT ADVISORY IS LIKELY AND A GALE WATCH IS POSSIBLE. THE WINDS
DIMINISH SOME BY LATE SATURDAY NIGHT.
SUNDAY...NORTHWEST WINDS ARE EXPECTED TO WEAKEN AND SHIFT TO
SOUTHWESTERLY, HOWEVER CONDITIONS MAY BE CLOSE TO SMALL CRAFT
ADVISORY CRITERIA FOR A TIME.
MONDAY...A SOUTHWESTERLY FLOW SHOULD GUST TO ABOUT 25 KNOTS, HOWEVER
THE AIRMASS IS WARMING AND THIS COULD REDUCE THE OVERALL MIXING.
&&
.CLIMATE...
**DECEMBERS RECORD WARMTH MAY BE REINFORCED WITH MORE DAILY
RECORDS TOWARD CHRISTMAS**
WE ARE BEGINNING THE PROCESS OF POSTING RECORD MAXIMUM TEMPERATURES
THAT MAY BE APPROACHED OR EXCEEDED, AS OUR FORECAST NUMBERS AND OR
MODEL OUTPUT STATISTICAL GUIDANCE (SOMETIMES REFERRED TO AS MOS OR
STAT GUIDE) APPROACH OR EXCEED THE RECORDS.
IF YOU REMEMBER, TEMPERATURES PEAKED GENERALLY IN THE 60S ON
DECEMBER 24-25 LAST YEAR AND AROUND DECEMBER 21-23 2013 (60S) AS
WELL.
12/23
ACY 65-1990
PHL 66-1990
ILG 66-1990
ABE 64-1990
TTN 70-1891
GED 68-2013 AND 1949
RDG 63-2007 AND 1990
MPO 58-1990
TEMPERATURES HAVE BEEN SO WARM THE FIRST 16 DAYS OF THE MONTH (9
TO 13 DEGREES ABOVE NORMAL) THAT IT WILL TAKE QUITE A SUBSTANTIAL
COLD SPELL TO PREVENT A RECORD WARM DECEMBER, AND THIS AFTER A TOP
8 NOVEMBER. HOWEVER, WE SUGGEST NOT EXTRAPOLATING WHAT IS AND HAS
HAPPENED AROUND HERE THESE PAST TWO MONTHS, FOR THE REST OF OUR
WINTER.
GEFS AND EC ENSEMBLES ARE CONTINUING AN ATTEMPT TO WARM US TO
RECORD WARM DAILY VALUES AGAIN TOWARD CHRISTMAS.
THEREAFTER, THE 00Z/17 GEFS CONTINUES A NOTABLE EAST COAST RIDGE!
FAST WESTERLY FLOW ACROSS THE NORTH ATLANTIC AND NO SIGN OF SUBSTANTIAL
RIDGING IN WESTERN NORTH AMERICA OR ANY DEPRESSED JET ACROSS THE
SOUTHERN USA ALL SUGGEST THAT BELOW NORMAL COLD IS NOT LIKELY HERE FOR
MORE THAN A DAY OR 2 (IF THAT), BETWEEN NOW AND THE NEW YEAR.
UNTIL SOMETHING WITHIN THAT OVERALL PATTERN CHANGES SUBSTANTIALLY,
WE WILL CONTINUE A GENERALLY ABNORMALLY MILD WEATHER. THE LACK OF
SNOW COVER ALSO CONTRIBUTES TO A POSITIVE DAILY DEPARTURE FROM
CLIMATOLOGY.
PROJECTIONS EVALUATED WITH THIS MORNINGS 330 AM FORECAST ARE
EASILY 8 TO 11 DEGREES ABOVE NORMAL FOR THE ENTIRE MONTH.
ABE NORMAL DECEMBER AVERAGE TEMPERATURE IS 32.3. WE ARE EXPECTING AROUND
43.0. THAT WOULD BE THE WARMEST SINCE RECORDS BEGAN IN 1922, AND
3 DEGREES WARMER THAN THE PREVIOUS WARMEST, DECEMBER 1923, WHEN
THE AVERAGE WAS 40.0
PHL NORMAL DECEMBER AVERAGE TEMPERATURE IS 37.5. WE ARE EXPECTING
AROUND 47.0. THAT WOULD BE THE WARMEST SINCE TEMPERATURE RECORDS
BEGAN IN 1874 (PRECIP RECORDS BEGAN THERE IN 1872). AND THIS WOULD
BE ALMOST 3 DEGREES WARMER THAN THE PREVIOUS WARMEST DECEMBER
1923, WHEN THE AVERAGE WAS 44.5 DEGREES.
THIS WAS CALCULATED USING OUR PHI 09Z/17 FORECAST THROUGH D7,
THEN ADDING ON THE D8-11 TEMPS FROM THE 00Z/17 NMCFTPRHA (GFS 2M
MAX/MIN TEMPS) AND FINALLY, FOR THE LAST 4 DAYS OF THE MONTH, WE
JUST USED STRAIGHT DAILY NORMALS FOR EACH LOCATION.
THE NUMBERS ABOVE WILL VARY FROM CURRENTLY PROJECTED... COULD SEE
CHANGES OF 2 DEGREES EITHER WAY, BUT OVERALL WHEN ALL THE DAILIES
ARE AVERAGED... IT APPEARS THERE IS CONSIDERABLE AND INCREASING
CUSHION ABOVE THE 2ND WARMEST EVER DECEMBER IN OUR AREA, FOR US TO
END UP EXPERIENCING OUR WARMEST DECEMBER ON RECORD, THROUGH 2015.
THE VALUES POSTED HERE MAY BE CONSERVATIVELY TOO COOL.
PHL HAS NOT BEEN BELOW NORMAL SINCE NOV 24TH. AND
PHILADELPHIA`S FIRST SUBFREEZING TEMPERATURE OF THE COOL SEASON SHOULD
OCCUR SUNDAY MORNING...THE LAST DAY OF FALL (DEC 20), EASILY EXCEEDING
THE PREVIOUS LATEST SUBFREEZING DATE OF DECEMBER 12 1998. OFFICIAL
TEMPERATURE RECORDS FOR PHILADELPHIA DATE BACK TO 1874.
PORTIONS OF ALL OF THIS SECTION OF THE AFD WILL BE DISCONTINUED
LATER TODAY BUT WILL BE UPDATED AGAIN FRIDAY MORNING AND THEN
AGAIN ON CHRISTMAS DAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 4 PM EST THIS
AFTERNOON FOR ANZ452>455.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG 531
SHORT TERM...DRAG 531
LONG TERM...GORSE
AVIATION...DRAG/GORSE 531
MARINE...DRAG/GORSE 531
CLIMATE...531
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
540 AM CST THU DEC 17 2015
.SHORT TERM...(Today)
ISSUED AT 316 AM CST THU DEC 17 2015
Cold front has passed well east of Illinois early this morning:
however, a large area of low clouds behind the boundary is
currently filtering into the area from the northwest. 09z/3am IR
satellite imagery shows the leading edge of the clouds along a
Champaign to Taylorville line...with overcast conditions upstream
across Iowa into the eastern Dakotas. HRRR has been handling the
clouds relatively well throughout the evening and shows them
spreading across the entire KILX CWA by 14/15z. Once the clouds
arrive, they will be very slow to depart...as NAM forecast
soundings indicate a persistent moist layer at around 925mb
through Friday morning. Thanks to cloudy skies and a chilly
northwesterly breeze of 10 to 15mph, high temperatures will be
near normal for this time of year. Have undercut MAV guidance
numbers by a couple of degrees, with readings mainly in the middle
to upper 30s.
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 316 AM CST THU DEC 17 2015
As mentioned in the short-term discussion, forecast soundings
suggest clouds will stick around through tonight before slowly
clearing from southwest to northeast across the area on Friday.
Short-wave trough evident on latest water vapor imagery over western
Wyoming will track southeastward into the Southern Plains this
evening then into the Tennessee River Vally by Friday morning. This
feature will remain well to the S/SW of Illinois and will not play a
factor in the weather across the KILX CWA. As a result, am
expecting a cold/dry day on Friday with highs once again remaining
in the 30s. As surface high pressure approaches from the west,
clearing skies and diminishing winds will allow low temperatures
Saturday morning to bottom out in the teens and lower 20s.
Once high pressure shifts east of the region, southerly return flow
will lead to a warming trend by Sunday. Gusty southwesterly
winds ahead of the next approaching cold front will boost high
temperatures into the upper 40s and lower 50s. 00z Dec 17 models
are in excellent agreement concerning the frontal boundary
expected to pass through central Illinois early Monday. Thanks
to a strong flow northward from the Gulf of Mexico, it appears
the front will have enough moisture to work with to trigger
scattered showers Sunday night into Monday morning. Front will
then quickly exit into Indiana, leading to a period of dry
weather Monday afternoon/night.
After that, model solutions diverge next week as W/SW upper flow
allows a series of systems to impact the region. Timing and
strength of these features remain in question, with the GFS showing
dry conditions Tuesday followed by a period of rain Wednesday into
early Thursday...while the ECMWF shows rain on Tuesday and again on
Wednesday. With such significant model spread still present, opted
to make only minor changes to the extended forecast beyond Monday.
Will keep PoPs in the slight chance category through much of the
period...but will highlight Tuesday night through Wednesday night as
the most likely period for rain with 40-50 PoPs. Regardless of
which model verifies, the main story next week will be the warmer
temperatures. All solutions show ridging across the eastern CONUS
and unseasonably warm 850mb temps, which will lead to highs well
into the 40s and 50s Monday through Wednesday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 536 AM CST THU DEC 17 2015
MVFR CIGS will prevail across the central Illinois terminals
through the bulk of the 12Z TAF valid time. Low level moisture
trapped beneath an inversion will be slow to clear, although some
clearing is possible by late tonight. Westerly winds will prevail
through the period as well, and will initially be a little gusty
this morning.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...BAK
AREA FORECAST DISCUSSION..CORRECTION
NWS DES MOINES IA
535 AM CST THU DEC 17 2015
.SHORT TERM /TODAY/...
ISSUED AT 315 AM CST THU DEC 17 2015
CLOUDS EXPECTED TO HOLD ON THROUGH AREA GOOD SHARE OF THE
DAY...THOUGH DRIER AIR ATTEMPTING TO PUNCH INTO WESTERN PORTION OF
THE FORECAST AREA BETWEEN 16Z AND 21Z THIS AFTERNOON. HRRR AND RAP13
BOTH HINT AT CLEARING AREA IN WESTERN DAKOTAS NOW WILL REACH THE
WEST BY LATE MORNING. COMPLICATING MATTERS...IS ANOTHER WEAK SHORT
WAVE BEHIND THE MAIN UPPER LOW. THIS WILL REACH THE NORTHERN
COUNTIES BETWEEN 21 AND 00Z THIS AFTERNOON. NAM SHOWS SLIGHTLY
BETTER MOISTURE WITH THE FEATURE AND A HINT AT SOME MINOR
INSTABILITY BY THEN AS WELL. UPSTREAM NOW...SCATTERED LIGHT FLURRIES
AND SOME BLOWING SNOW REPORTED. WILL ADD FLURRIES FAR NORTHWEST
BETWEEN 21 AND 00Z AS THE WEAK WAVE APPROACHES.
OTHERWISE ...TEMPERATURES WILL BE MORE SEASONAL WITH HIGHS IN THE
UPPER 20S NORTH TO MID 30S IN THE SOUTH. NORTHWEST WINDS WILL
INCREASE AGAIN THIS AFTERNOON AS MIXING BEGINS. BETTER WINDS AND
GUSTS ACROSS THE NORTH WITH AMBIENT FLOW OF AROUND 20 MPH AND
GUSTS TO NEARER 30 MPH AT TIMES TODAY.
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 315 AM CST THU DEC 17 2015
MAIN FORECAST CONCERN WAS FOCUSED ON SNOW SQUALL POTENTIAL AND
GUSTY WINDS FRIDAY OVER NORTHERN IOWA AND TEMPERATURES THROUGH
THE WEEKEND AND INTO NEXT WEEK. MODELS ARE COMING INTO SLIGHTLY
BETTER AGREEMENT WITH SYSTEM SUNDAY NIGHT INTO MONDAY AND UTILIZED
A GFS20/ECMWF BLEND SUNDAY INTO NEXT WEEK. TONIGHT INTO
SATURDAY...USED A NAM12/SREF/GFS20 BLEND.
TONIGHT INTO FRIDAY...UPPER LEVEL TROUGH WILL CONTINUE TO MOVE
ACROSS THE REGION TONIGHT INTO FRIDAY...WITH A SECONDARY PUSH OF CAA
ANTICIPATED VIA A FAIRLY STRONG PV ANOMALY IS EXPECTED LATE FRIDAY
MORNING. CONCERNED FOR POTENTIAL FOR SNOW SQUALLS OVER NORTHERN
IOWA LATE FRIDAY MORNING INTO THE AFTERNOON. NAM/GFS BUFR
SOUNDINGS SATURATE THE DENDRITIC LAYER B/T 15-21Z AND WINDS ATOP
THE MIXED LAYER RANGE AROUND 30-35 KNOTS. DECENT FORCING
ASSOCIATED WITH THE PV ANOMALY ALONG WITH SOME WEAK ELEVATED
INSTABILITY PRESENT TOWARDS THE AFTERNOON HOURS OVER NORTHERN
IOWA. ALBEIT THE NAM12 IS LIKELY OVERDOING THE INSTABILITY.
HOWEVER...THERE WAS ENOUGH OF A SIGNAL TO AT LEAST INCREASE
WORDING TO PERIODS OF SNOW SHOWERS ON FRIDAY. LOW CONFIDENCE IN
ANY SNOW ACCUMULATION AND THUS LEFT OUT POPS. CERTAINLY COULD HAVE
GONE WITH THE CATEGORICAL POPS/LOW QPF SCENARIO AND SOMETHING TO
CONSIDER NEXT FORECAST PACKAGE IF MODELS CONTINUE WITH THIS
SIGNAL. SOUNDINGS QUICKLY LOSE THEIR MOISTURE PAST 21Z FRIDAY AND
ONLY HAVE FLURRIES MENTIONED AFTER THIS TIME FRAME.
FRIDAY NIGHT INTO SUNDAY...SURFACE HIGH PRESSURE BUILDS INTO THE
STATE AND CENTERS ITSELF OVER THE FORECAST AREA BY SATURDAY MORNING.
THIS WILL PROVIDE GOOD RADIATION COOLING AND LOWERED TEMPERATURES
2 TO 4 DEGREES ACROSS THE FORECAST AREA. THINKING THE GFS IS TOO
COLD...BUT ECMWF/NAM WERE IN GOOD AGREEMENT FOR LOWS SATURDAY
MORNING.
TEMPERATURES LOOK TO QUICKLY REBOUND ON SATURDAY AS WAA DEVELOPS
LATE SATURDAY MORNING AS THE SURFACE MOVES EAST. THE WAA PERSISTS
INTO SUNDAY AND HAVE A NON-DIURNAL TEMPERATURE TREND GOING
SATURDAY NIGHT INTO SUNDAY. THIS RESULTED IN INCREASING MINIMUM
TEMPERATURES SATURDAY NIGHT AND MAXIMUM TEMPERATURES ON SUNDAY.
SURFACE LOW PRESSURE EJECTS OUT OF THE CENTRAL ROCKIES WITH A
POTENT 500MB VORT MAX TRAILING BEHIND IT ON SUNDAY. THE PHASING
BETWEEN THE TWO COME TOGETHER EAST OF THE FORECAST AREA BY SUNDAY
NIGHT AS THE LOW DEEPENS OVER THE GREAT LAKES REGION. THUS...THE
BEST FORCING TRAILS BEHIND THE DEEPEST MOISTURE IN EASTERN IOWA
AND HAVE LOW POPS GOING SUNDAY INTO SUNDAY NIGHT.
MONDAY INTO WEDNESDAY...MONDAY WILL BE COOLER AS CAA CONTINUES
THROUGH MUCH OF THE DAY BEFORE WEAKENING BY THE LATE AFTERNOON.
AFTER A QUIET DAY TUESDAY...STRONG WAA AND THETA-E ADVECTION
DEVELOP ON WEDNESDAY AHEAD OF A DEEPENING LOW PRESSURE SYSTEM OVER
THE DAKOTAS. HOWEVER...GFS/ECMWF REMAIN IN DISAGREEMENT TIMING AND
LOCATION AS ECMWF IS FURTHER NORTH AND SLIGHTLY FASTER IN THE
PROGRESSION. POTENTIAL FOR SOME LIGHT PRECIP OVER EASTERN AND
NORTHERN PORTIONS OF THE FORECAST AREA WEDNESDAY INTO THURSDAY.
&&
.AVIATION...17/12Z
ISSUED AT 534 AM CST THU DEC 17 2015
MVFR CONDITIONS CONTINUE...WITH A FEW BREAKS ACROSS NC SECTIONS
BETWEEN 12-15Z. GRADUALLY LIFTING CIGS TO VFR WILL OCCUR AT KFOD
AND KDSM AFT 19Z-21Z WITH VFR CONDITIONS TO REMAINDER SITES AFT
21Z MOST AREAS. SOME SCT --SW NORTH AFT 21Z. WINDS INCREASE...
ESPECIALLY NORTH AT KMCW WITH 20KT GUSTS 26KTS AFT 21Z. /REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...PODRAZIK
AVIATION...REV
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
530 AM CST THU DEC 17 2015
...Updated for Aviation...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 123 AM CST THU DEC 17 2015
An upper level disturbance will approach the region from the northwest
this morning and move across the state through today. This will lead
to some snow showers across the region. Moisture is mainly rooted in
the 850-600-hPa layer, so a significant precip maker is not expected.
Increased pops to high chance category given decent agreement between
global and mesoscale models. Largely followed the ARW for pop arrangement
with a slight bias towards the ECMWF as well. Have 1" snow accumulations
within a polygon from Syracuse to Dodge City to Dighton. This is mostly
in agreement with WPC. The ARW and HRRR show amounts over 2". Will not
issue a winter weather advisory since grid values are below criteria.
Not expecting a major impact as well in terms of hazardous travel conditions.
Also have undercut highs for today as plenty of cloud cover is expected.
Lows heading into Friday morning will be mainly in the teens as high
pressure builds in and the sky clears.
.LONG TERM...(Friday THROUGH Wednesday)
ISSUED AT 123 AM CST THU DEC 17 2015
A dry forecast is expected through the rest of the forecast domain.
There is still some chatter about a significant storm system by the
end of December. This is not an official NWS forecast and was only based
on one model solution (a poor performing model at that). FWIW, that
snow storm is not even shown anymore for SW Kansas on said model. Anyway,
pops will remain aob 14 percent. No significant precipitation is expected
to close out the extended. A frontal system will move through Sunday,
however, wind is mainly associated with this system. Any precip should
remain in eastern Kansas. Beyond this, a zonal flow pattern sets up.
This will favor near to above normal temperatures. Another dry system
might move across towards the holiday. Ahead of this system, might
end up fairly warm for xmas.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Friday MORNING)
ISSUED AT 522 AM CST THU DEC 17 2015
An upper level shortwave trough will move across southwestern
Kansas today bringing areas of light snow and minor accumulations.
The snow should begin in the KGCK area around 13-15Z, KDDC from
14-16Z and KHYS around 16-18Z and last through 18-22Z. Some cigs
of IFR/MVFR with 3 to 5 mile vsbys are expected with the snow
followed by clearing and light and variable winds.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 15 41 25 / 50 20 0 0
GCK 31 14 46 23 / 50 20 0 0
EHA 31 14 46 26 / 30 10 0 0
LBL 32 15 43 24 / 40 10 0 0
HYS 31 16 43 22 / 20 20 0 0
P28 37 18 47 25 / 30 20 0 0
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Sugden
LONG TERM...Sugden
AVIATION...Kruse
AREA FORECAST DISCUSSION
NWS GOODLAND KS
419 AM MST THU DEC 17 2015
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 205 AM MST THU DEC 17 2015
EARLY MORNING WV IMAGERY SLOWS SHORTWAVE TROUGH OVER
WYOMING/NORTH CENTRAL COLORADO MOVING TO THE SOUTHEAST. RAP UPPER
LEVEL ANALYSIS SHOWS STRONG H3 JET (100-120KT) UPSTREAM OF THIS
FEATURE MOVING INTO WESTERN WYOMING. LARGE SCALE PATTERN IS
DOMINATED BY AMPLIFYING RIDGE ALONG WESTERN US COAST AND LONGWAVE
TROUGH ACROSS THE CENTRAL US. LIGHT SNOW IS ALREADY BEING REPORTED
AT AKRON COLORADO UPSTREAM FROM OUR CWA.
TODAY-TONIGHT...UPPER LEVEL SHORTWAVE TROUGH IS SHOWN TO SPLIT
AROUND OUR CWA WITH STRONGEST FORCING STARTING TO OUR
WEST/NORTHWEST AND THEN TRENDING TO THE SOUTHEAST WITH MEAN FLOW
THROUGH THIS AFTERNOON AND EVENING. BEST FORCING APPEARS TO BE
MIDDAY THROUGH THE AFTERNOON...THOUGH NOSE OF UPPER LEVEL JET WILL
ACTUALLY BE PASSING THROUGH THE REGION THIS EVENING. GFS INITIATED
WITH A LITTLE MORE MOISTURE THAN 00Z SOUNDINGS WOULD HAVE
INDICATED AND NAM/RAP MOISTURE PROFILES WERE FAVORED. THIS WILL BE
CRITICAL AS MOISTURE APPEARS TO BE THE LIMITING FACTOR OF
DURATION/EXTENT OF SNOWFALL TODAY. RAP/NAM SUPPORT SATURATION
AROUND OR AFTER 18Z IN THE CENTRAL PART OF OUR FORECAST
AREA...WITH A 3HR PERIOD OF LIGHT QPF TRANSLATING ACROSS THE
AREA. WITH UPSTREAM OBS ALREADY SHOWING LIGHT SNOW I SHOWED A
SLIGHTLY FASTER TREND IN THE NORTHWEST. I THEN USED 925-700 MB
LAYER QG FRONTOGENESIS AND RH A GOOD PROXY FOR TRACK OF THIS AREA
OF SNOWFALL.
THE AIR MASS ALREADY IN PLACE IS COLD ENOUGH THAT WHEN SATURATED WE
SHOULD SEE ALL SNOW...AND WITH CAA THROUGH THE AFTERNOON HIGHER
RATIOS SHOULD BE SUPPORTED. VERY DRY AIR ADVECTS BACK INTO THE
REGION BEHIND THIS FAST MOVING SHORTWAVE SO BY EARLY THIS EVENING
PRECIP SHOULD BE WINDING DOWN FROM THE NORTHWEST TO THE SOUTHEAST.
BASED ON LATEST CONSENSUS QPF AND SNOW-LIQUID RATIOS IN THE 15-18
RANGE WE SHOULD SEE ACCUMULATIONS IN THE 0.5-1.5" RANGE...BEST
CHANCES ALONG A WRAY TO RUSSEL SPRINGS LINE. WHILE BRIEF
VISIBILITY REDUCTIONS ARE POSSIBLE...THEY SHOULDN`T BE WIDESPREAD
OR PERSISTENT CONSIDERING LIMITED WINDS DURING THE EVENT (WINDS DO
INCREASE SOME BEHIND SHORTWAVE). I PLAN ON KEEPING MENTION
LIMITED TO HWO.
FRIDAY-SATURDAY NIGHT...UPPER LEVEL RIDGING BUILDS ACROSS THE
CENTRAL ROCKIES/PLAINS FRIDAY AND SHIFTS EAST WITH SW FLOW
DEVELOPING SATURDAY. THIS WILL SUPPORT DRY CONDITIONS THROUGH THESE
PERIODS WITH WARMER TEMPERATURES. DEPENDING ON ANY SNOW PACK FRIDAY
WARM UP MAY BE TEMPERED SLIGHTLY...THOUGH POTENTIAL FOR HIGHS IN THE
LOWER 50S EXISTS. SATURDAY SHOULD BE MILD WITH STRONGER LEE TROUGH
DEVELOPMENT AND SW FLOW SUPPORTING STRONGER WAA. STATISTICAL
GUIDANCE HAS TRENDED TOWARDS LOW TO MID 50S...AND THIS SEEMS
REASONABLE CONSIDERING TEMPS ALOFT AND PATTERN.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 144 AM MST THU DEC 17 2015
FORECAST PROBLEM...ALBEIT A MINOR ONE...IS A LOW CHANCE OF
PRECIPITATION TOWARD THE END OF THIS PERIOD. SATELLITE CURRENTLY
SHOWING AN AMPLIFIED PATTERN FROM THE CENTRAL PACIFIC INTO THE
CENTRAL ATLANTIC.
IN GENERAL THE PATTERN THIS PERIOD WILL BE PROGRESSIVE AND NEARLY
ZONAL AT TIMES. A NUMBER OF FAST MOVING OPEN TROUGHS MOVE THROUGH
DURING THIS TIME. THE FIRST ONE IS ON SUNDAY. THE ECMWF/GFS SPIT OUT
A FEW HUNDREDTHS OF QPF. HOWEVER LOOKING AT THE SOUNDINGS THERE IS A
VERY DEEP DRY LAYER IN PLACE. SO LEFT ALONE THE DRY FORECAST THE
INIT GAVE ME.
A TROUGH COMES ACROSS ON WEDNESDAY AND THE INIT GAVE ME SOME SLIGHT
CHANCE POPS IN THE WEST AND THAT LOOKS REASONABLE. OVERALL MADE NO
CHANGES TO WHAT THE INIT GAVE ME. HOWEVER GIVEN THE FAST WESTERLY
PATTERN WOULD NOT BE SURPRISED IF HIGH TEMPERATURES END UP BEING
A LITTLE WARMER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 419 AM MST THU DEC 17 2015
LOW LEVEL MOISTURE POOLING ALONG HIGH PRESSURE AXIS HAS LED TO
STRATUS AROUND 1200-2000 KFT AGL OVER SOUTHWEST NEBRASKA IMPACTING
KMCK. SHORT RANGE GUIDANCE SHOWS THIS LIFTING AROUND 15Z. AN
UPPER LEVEL DISTURBANCE IS STILL EXPECTED TO BRING LIGHT SNOW TO
THE REGION TODAY WITH BEST CHANCES AROUND MIDDAY TRANSITIONING TO
THE SOUTHEAST THROUGH THE AFTERNOON. FLURRIES COULD OCCUR BEFORE
MAIN AREA OF SNOW DEVELOPS LATER THIS MORNING. LIGHT SNOW
ACCUMULATIONS WILL BE POSSIBLE AT BOTH TERMINALS WITH BEST CHANCE
AT KGLD. MVFR VIS AND CIGS ARE EXPECTED WITH MAIN AREA OF SNOW.
WHILE IFR CONDITIONS ARE POSSIBLE...CONFIDENCE IS TOO LOW IN
DURATION AND TIMING TO KEEP MENTION IN TEMPO THIS AFTERNOON. WILL
NEED TO MONITOR SHORT RANGE TRENDS. VFR CONDITIONS SHOULD RETURN
TO BOTH KGLD AND KMCK LATE THIS AFTERNOON (BY 00Z) AND PREVAIL
THROUGH THE REMAINING TAF PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...DR
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
554 AM CST THU DEC 17 2015
.DISCUSSION...
Issued at 408 AM CST THU DEC 17 2015
Despite the presence of a larger meridional upper trough centered
over Plains other than an extensive region of stratus expect benign
but seasonably cold conditions today. Water vapor satellite imagery
does show an elongated shortwave trough diving southeast on the
backside of the trough. All we can expect to see from this feature
is broken mid clouds later today. Of greater importance will be cold
advection stratus spreading across the CWA this morning. Following
the RUC as it`s handling these low clouds best. With the low clouds
likely to last for most if not all day the diurnal range should be
limited to around 5F.
Coldest readings of the season expected tonight as clouds clear and
drier air advects into the region. Abundant sunshine on Friday will
help temperatures recover to normal readings. However, a secondary
area of high pressure will overspread the region Friday night.
Overnight lows will dip into the middle/upper teens across the
northern 1/2 of the CWA where winds will likely go calm as the
center of the high passes overhead.
As has been advertised for the past several days warm advection will
reassert itself over the weekend as upstream upper level ridging
builds and advances eastward. Medium range models continue to
maintain run-to-run consistency in bringing a shallow fast-moving
shortwave through the Central Plains late in the weekend. They
develop an impressive low-level jet in excess of 50kts which will
pull up modified gulf moisture. The moisture remains suspect over
western MO while central MO has a much better chance of seeing rain
form due to better quality/depth of the moisture return.
The overall pattern next week remains unsettled although Monday and
Tuesday are looking dry with above average temperatures before a
progressive shortwave trough brings a chance for precipitation. With
temperatures expected to remain above freezing Tuesday night and
Wednesday rain is the preferred precipitation type.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 551 AM CST THU DEC 17 2015
An extensive area of MVFR ceilings will remain over northern into
central MO as well as adjacent east central KS through most of the
afternoon. Should see this cloud shield clear from northwest to
southeast starting over northwest MO by late afternoon. VFR
conditions will replace this cloud cover as it clears.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...MJ
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
408 AM CST THU DEC 17 2015
.DISCUSSION...
Issued at 408 AM CST THU DEC 17 2015
Despite the presence of a larger meridional upper trough centered
over Plains other than an extensive region of stratus expect benign
but seasonably cold conditions today. Water vapor satellite imagery
does show an elongated shortwave trough diving southeast on the
backside of the trough. All we can expect to see from this feature
is broken mid clouds later today. Of greater importance will be cold
advection stratus spreading across the CWA this morning. Following
the RUC as it`s handling these low clouds best. With the low clouds
likely to last for most if not all day the diurnal range should be
limited to around 5F.
Coldest readings of the season expected tonight as clouds clear and
drier air advects into the region. Abundant sunshine on Friday will
help temperatures recover to normal readings. However, a secondary
area of high pressure will overspread the region Friday night.
Overnight lows will dip into the middle/upper teens across the
northern 1/2 of the CWA where winds will likely go calm as the
center of the high passes overhead.
As has been advertised for the past several days warm advection will
reassert itself over the weekend as upstream upper level ridging
builds and advances eastward. Medium range models continue to
maintain run-to-run consistency in bringing a shallow fast-moving
shortwave through the Central Plains late in the weekend. They
develop an impressive low-level jet in excess of 50kts which will
pull up modified gulf moisture. The moisture remains suspect over
western MO while central MO has a much better chance of seeing rain
form due to better quality/depth of the moisture return.
The overall pattern next week remains unsettled although Monday and
Tuesday are looking dry with above average temperatures before a
progressive shortwave trough brings a chance for precipitation. With
temperatures expected to remain above freezing Tuesday night and
Wednesday rain is the preferred precipitation type.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 948 PM CST WED DEC 16 2015
Light westerly winds overnight will increase tomorrow and low clouds
will be increasing ahead on an incoming upper level trough. Cigs are
expected to remain VFR but may decrease into upper MVFR at a few
terminals. The system will quickly move across the region with cloud
cover clearing out by late in the prevailing TAF period.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...PMM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1050 AM EST THU DEC 17 2015
.SYNOPSIS...
A COLD FRONT CROSSES THE AREA TODAY WITH WIDESPREAD RAINFALL. THIS
FRONT WILL BE ALONG THE COAST BY FRIDAY MORNING. A STRONG UPPER
LEVEL TROUGH WILL BRING US BACK COLDER TEMPERATURES INTO THE
WEEKEND...BUT THIS WILL BE SHORT-LIVED. ANOTHER COLD FRONT WILL
MAKE ITS WAY TOWARDS THE REGION AND IMPACT THE AREA MONDAY INTO
TUESDAY OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM EST THURSDAY...
WIDESPREAD LIGHT TO MODERATE RAIN WAS STILL OCCURRING ACROSS THE
REGION AS A COLD FRONT ENTERS THE FAR WESTERN SECTION OF THE
FORECAST AREA. PRECIPITATION WILL CONTINUE IN ADVANCE OF THIS
FRONT HEADING INTO THE AFTERNOON. DURING THE AFTERNOON HOURS...THE
FRONT WILL CROSS THE REGION...AND AS A RESULT...THE ASSOCIATION
PRECIPITATION SHIELD WILL ALSO PROGRESS EASTWARD WITH
IT...BRINGING DECREASING COVERAGE OF PRECIPITATION TO WESTERN
PARTS OF THE AREA FIRST. LATER IN THE AFTERNOON...PRECIPITATION IS
EXPECTED TO INCREASE AGAIN ACROSS THE PREFERRED UPSLOPE AREAS OF
SOUTHEAST WEST VIRGINIA...SOUTH INTO THE NORTHERN MOUNTAINS OF
NORTH CAROLINA AS NORTHWEST FLOW BEHIND THE FRONT STARTS TO
INCREASE.
AS OF 622 AM EST THURSDAY...
LATEST RADAR SHOWING BROAD AREA OF RAIN OVER MOST OF THE FORECAST
AREA. THE 11Z RAP MESOANALYSIS SHOWED BEST UPPER DIVERGENCE NOW
OVER SE WV EAST TO LYH-RIC. THERE IS SOME WEAKENING TO THE SOUTH
TO THE RAIN. AT THIS TIME...HRRR DEPICTING THINGS THE BEST. GIVEN
THIS...WILL STILL SEE GREATEST CONCENTRATION OF RAIN THROUGH EARLY
AFTERNOON...THEN SHOULD SEE A DRYING TREND IN THE WEST...AND
FASTER MOVING OUT THIS EVENING OF THE RAIN...SO SPED UP THE DRYING
WITH THIS UPDATE.
PREVIOUS DISCUSSION FROM EARLY THIS MORNING...
FRONTAL BOUNDARY EARLY THIS MORNING STRETCHES FROM A 990MB LOW
OVER THE NRN TIP OF LAKE SUPERIOR SOUTHWARD INTO CENTRAL KY/MID
TN...WITH A WEAK LOW PRESSURE WAVE OVER ERN KY ALONG A WARM
FRONTAL BOUNDARY. RADAR INDICATING LIGHT TO AT TIMES MODERATE RAIN
MOVING NNE ACROSS THE NC INTO SOUTHSIDE VA AND OVER WV/FAR SW VA.
MODELS IN AGREEMENT ON THE SYNOPTICS...THOUGH SOME DIFFERENCES ON
PLACEMENT OF HIGHER QPF...WITH THE NAM A LITTLE WEST OF THE
GFS/ECMWF.
EARLY THIS MORNING THE BEST UPPER DIVERGENCE WITH THE 140KT 300MB
JET WAS OVER ERN TN INTO THE NC PIEDMONT. THE GFS PICKED UP ON THIS
UPPER PATTERN WELL AND GENERALLY FOLLOWED ITS SOLUTION BLENDED WITH
THE ECMWF. THE QPF WILL BE HIGHEST ALONG AND EAST OF THE BLUE RIDGE
WHICH WE HAVE BEEN ADVERTISING THE PAST 2 DAYS. EXPECT THE RAIN TO
BE HEAVY AT TIMES TODAY IN ASSOCIATION WITH A STRONGER LOW LVL JET
MOVING IN FROM UPSTATE SC AT 7AM INTO THE VA/NC PIEDMONT BY NOON.
STRONG PRESSURE FALLS OVER THE MID ATLANTIC THIS AFTERNOON INDICATES
POTENTIAL FOR THAN ONE WAVE OF LOW PRESSURE TO FORM ALONG THE FRONT.
DIFFICULT TO SEE HOW SLOW AND HOW FAR WEST THE RAIN WILL LINGER INTO
THE PIEDMONT INTO EARLY EVENING...SO KEPT SOME HIGHER POPS EAST OF A
LYNCHBURG TO MARTINSVILLE LINE...THEN TAPER TO CHANCE BY MIDNIGHT.
EXPECT CATEGORICAL POPS AREA WIDE THROUGH MOST OF THE DAY WITH
DEEPER MOISTURE POISED TO MOVE OUT OF THE MOUNTAINS BY DUSK...THOUGH
LOW LVL MOISTURE REMAIN ACROSS THE WESTERN SLOPES THROUGH TONIGHT.
ALTHOUGH THE STORM PREDICTION CENTER HAS A GENERAL THUNDER RISK INTO
THE PIEDMONT...APPEARS THAT INSTABILITY IS NIL...AND MAINLY HAVING
STRONG JET DYNAMICS TO AID IN LIFT...SO ANY THUNDER WOULD BE PRESSED
FURTHER EAST TOWARD THE COAST WHERE THERE IS A BETTER ENVIRONMENT
FOR THAT THIS AFTERNOON. STILL SOME STRONGER CONVECTIVE ELEMENTS
COULD MOVE ACROSS THE PIEDMONT OF VA/NC THROUGH MID AFTERNOON.
RAINFALL AMOUNTS FROM EARLY THIS MORNING THROUGH THURSDAY EVENING
WILL RANGE FROM 1 TO 1.25 ALONG/EAST OF THE BLUE RIDGE WITH LOCALLY
HIGHER AMOUNTS POSSIBLE. WEST...EXPECT THREE QUARTERS TO AN INCH.
SEE HYDRO SECTION BELOW FOR COMMENTS ABOUT IMPACTS ON
STREAMS/RIVERS.
TEMPERATURES THIS MORNING WILL STAY STEADY OR SLOWLY RISE BUT WITH
RAINFALL MOVING IN...GOING TO SEE HIGHS HELD IN CHECK WITH LOWER TO
MID 50S MOST AREAS...AND UP TO 60 IN SOUTHSIDE VA INTO NW NC
PIEDMONT. STILL THIS ABOUT 5-10 DEGREES ABOVE NORMAL.
TONIGHT...AS THE 8H FRONT MOVES EAST...STRONGER COLD ADVECTION
SLIDES INTO THE MOUNTAINS. MOISTURE DEPTH OVERALL IS SUFFICIENT FOR
SOME LIGHT RAIN CHANGING TO SNOW SHOWERS AFTER MIDNIGHT...THOUGH
ACCUMULATION THROUGH DAWN IS GOING TO BE LITTLE/NONE. TEMPS MAY
STAY ELEVATED ACROSS THE PIEDMONT UNTIL A LATE DROP. AS SUCH HAVE
LOWS RANGING FROM THE LOWER 30S ACROSS THE WESTERN SLOPES TO MID
30S NEW RIVER VALLEY/BLUE RIDGE...UPPER 30S TO LOWER 40S ROANOKE
TO LYNCHBURG...AND FOOTHILLS...WITH MID TO UPPER 40S FROM
FARMVILLE TO YADKINVILLE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 249 AM EST THURSDAY...
A COLD FRONT WILL MOVE OFF THE EAST COAST FRIDAY SENDING
TEMPERATURES DOWN INTO THE 30S AND 40S FRIDAY AFTERNOON. SINCE THE
WEATHER HAS BEEN VERY WARM FOR THE LAST COUPLE OF WEEK...THIS DROP
IN TEMPERATURES WILL SEEM LIKE AN ARCTIC AIRMASS...BUT IN REALITY
TEMPERATURES WILL BE SEASONAL FOR ONCE. THOSE WHO ARE NOT FANS OF
COLD WEATHER WILL BE HAPPY WHEN WARMER THAN NORMAL TEMPERATURES
RETURN ON SUNDAY.
THROUGH THE DAY FRIDAY...85H TEMPERATURES WILL CONTINUE TO FALL AS
COLD AIR RUSHES IN ON NORTHWEST FLOW. HIGH TEMPERATURES FRIDAY WILL
LIKELY OCCUR DURING THE MORNING FOR THE MOUNTAINS AND EARLY
AFTERNOON IN THE PIEDMONT. DESPITE MORNING TEMPERATURES BEING IN THE
UPPER 30S TO LOWER 40S...WILL KEEP ANY MOUNTAIN PRECIPITATION AS
SNOW AS LOW LEVEL WARM BOUNDARY LAYER WILL BE SHALLOW. SOME SNOW
ACCUMULATIONS ARE POSSIBLE DURING THE DAY FRIDAY FOR THE HIGHER
ELEVATIONS OF SE WV ABOVE 3000 FEET. BELOW 3000 FEET...GROUND
TEMPERATURES SHOULD REMAIN WARM THROUGH THE DAY TO KEEP ANY
ACCUMULATION TO A DUSTING OR LESS ON ELEVATED SURFACES AND ONLY
ALONG WESTERN SLOPES. AROUND 400 PM INTO THE NIGHT...ACCUMULATIONS
CHANCES INCREASE ALONG HIGHER ELEVATIONS AND WESTERN SLOPES FROM SE
WV...MOUNTAIN EMPIRE AND GRAYSON HIGHLAND OF SW VA AND THE NC HIGH
COUNTY. THIS UPSLOPE EVENT IS LACKING MOISTURE AND ACCUMULATIONS MAY
AMOUNT TO AN INCH OR SO FROM DRY SNOW. THE UPPER LEVEL TROUGH PIVOTS
TO THE MID ATLANTIC COAST SATURDAY MORNING...ENDING THIS BRIEF
UPSLOPE EVENT. PRESSURE RISES BEHIND THE FRONT FRIDAY AND FRIDAY
NIGHT WILL ALSO BRING BREEZY AND GUSTY WINDS TO THE FORECAST AREA.
THIS WIND MAY BE ENOUGH TO PUSH FLURRIES TO THE BLUE RIDGE FRIDAY
AFTERNOON AND EVENING. WIND SPEEDS WILL BE BORDER-LINE FOR AN
ADVISORY FRIDAY...BUT THINK CLOUDS WILL LIMIT HIGHER SPEEDS FROM
MIXING TO THE GROUND. ANOTHER SURGE IN WINDS IS EXPECTED SATURDAY
BUT THE 85H JET IS WEAKER THAN FRIDAY. CONFIDENCE ON AREAL COVERAGE
FOR STRONG WINDS IS LOW TO ISSUE HEADLINES AT THIS TIME. HIGH
PRESSURE BUILDS IN FROM THE SOUTHWEST SATURDAY AFTERNOON TO RELAX
THE WINDS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 PM EST WEDNESDAY...
THE COOL DOWN LOOKS TO BE SHORT-LIVED AS UPPER HEIGHTS BEGIN TO
BUILD YET AGAIN ON SUNDAY WITH 850 TEMPS BOUNCING BACK TO +4C TO +8C
BY LATE IN THE DAY AND SURFACE TEMPS BACK SLIGHTLY ABOVE
CLIMO...REACHING UPPER 40S NW TO LOW 50S SE. CLOUDS BEGIN TO
INCREASE FROM LATE SUNDAY INTO MONDAY AS THE SURFACE RIDGE MOVES
OFF THE EAST COAST AND TAKES UP RESIDENCE OVER THE WESTERN
ATLANTIC. A COOL FRONT ASSOCIATED WITH A GREAT LAKES LOW WILL
APPROACH THE REGION BUT THEN BECOMES RATHER DIFFUSE AND POORLY
ORGANIZED INTO TUESDAY AS HEIGHTS BUILD OFF THE EAST COAST AND
ANOTHER WESTERN TROUGH BEGINS TO DEVELOP. WILL SEE GRADUAL UPSWING
IN TEMPS/POPS THROUGH THE MID- WEEK PERIOD AS SW FLOW ALOFT BRINGS
WARMTH/MOISTURE NORTHWARD. SHOULD SEE VERY MILD HIGHS IN THE 50S
AND 60S AND LOWS MAINLY IN THE 40S OR EVEN LOW 50S. THESE NUMBERS
ARE ROUGHLY 10 TO 15F ABOVE NORMAL AND WILL KEEP US ON TRACK FOR
WHAT COULD BE A RECORD- BREAKING WARM DECEMBER. THROUGH MID-MONTH
(DEC. 1-15) ALL 5 CLIMATE SITES ARE IN THE TOP 5 ALL-TIME AND
BLUEFIELD IN 1ST PLACE (SINCE 1959). COULD ALSO SEE MODERATE TO
POSSIBLY HEAVY RAINFALL DURING MUCH OF THIS PERIOD...UP TO AN INCH
OR MORE POSSIBLE...BUT FOCUS FOR HEAVIEST RAINS STILL APPEARS TO
BE FURTHER TO THE SOUTHWEST ALONG THE GULF COAST.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
AS OF 640 AM EST THURSDAY...
CIGS THIS MORNING VARY FROM IFR TO VFR WITH LIGHT TO MODERATE RAIN
MOVING ACROSS. MAJORITY OF THE DAY WILL SEE RAIN WITH MVFR OR
LOWER CIGS/VSBYS AT ALL SITES. HIGH RES MODELS BRING AN END TO THE
RAIN IN THE LWB/BLF AREA BY 20Z...BCB/ROA BETWEEN 21-00Z...AND
EAST OF LYH/DAN BY 00-01Z. WINDS WILL SHIFT FROM VARIABLE TO SOUTH
THIS MORNING THEN AS THE FRONT MOVES ACROSS TO THE WNW. WINDS WILL
STAY AROUND 10KTS OR LESS. A STRONG LOW LVL JET MOVES ACROSS THIS
MORNING MAINLY EAST OF THE BLUE RIDGE SO LOW LVL WIND SHEAR WAS
KEPT IN LYH/DAN/BCB AROUND 15-19Z.
ONCE THE WINDS SHIFT AROUND TO THE WEST ANTICIPATE CIGS TO LIFT TO
VFR THIS EVENING ROA/LYH/DAN AND BY 06Z AT BCB...WHILE BLF/LWB
KEEP MVFR/IFR CIGS AROUND 1KFT THROUGH THE NIGHT. ATTM...LEFT OUT
SNOW SHOWERS OR DRIZZLE AS MOISTURE AT LWB/BLF LOOKS LACKING.
.EXTENDED AVIATION DISCUSSION...
GUSTY NORTHWEST WINDS FRIDAY INTO FRIDAY NIGHT ON THE BACKSIDE OF
THE DEPARTING SYSTEM WILL KEEP UPSLOPE IFR/MVFR CLOUDS AND
ISOLATED RAIN OR SNOW SHOWERS ACROSS THE MOUNTAINS...ESPECIALLY
PARTS OF SOUTHEAST WEST VIRGINIA INTO THE NORTHERN MOUNTAINS OF
NORTH CAROLINA. SNOW SHOWERS ALONG WITH MVFR CEILINGS ARE LIKELY
IN SOUTHEAST WEST VIRGINIA ON FRIDAY AND SATURDAY.
THE PRESSURE GRADIENT WILL SLACKEN SATURDAY NIGHT INTO SUNDAY AS
THE CENTER OF HIGH PRESSURE BUILDS INTO THE REGION. THIS WILL ALSO
BRING AN END TO UPSLOPE CLOUDS AND LIGHT PRECIPITATION. VFR
CONDITIONS ARE EXPECTED SUNDAY.
BY LATE SUNDAY NIGHT INTO MONDAY...THE NEXT COLD FRONT WILL BE ON
OUR WESTERN EDGES OF THE FORECAST AREA. LOOK FOR A RETURN OF MVFR
CLOUD COVER...STRONGER LOW LEVEL WINDS...AND PRECIPITATION WITH
THE APPROACH AND PASSAGE OF THIS FRONT.
&&
.HYDROLOGY...
AS OF 300 AM THURSDAY...
FORECAST RAINFALL AMOUNTS OF THREE QUARTERS TO 1.5 INCHES WILL
BRING RISES ON THE SMALLER CREEKS AND STREAMS LATER TODAY BUT
OVERALL THE THREAT OF FLOODING WILL BE LOW. STILL CANNOT RULE OUT
SOME HIGHER RAINFALL RATES THAT COULD BRING PONDING OF WATER OR
POOR DRAINAGE FLOODING TO URBAN AREAS...BUT THIS DOES NOT WARRANT
A FLOOD WATCH.
IMPACTS ON THE MAIN STEM RIVERS INTO FRIDAY TO SATURDAY SHOWS ONLY
SOUTH BOSTON REACHING ACTION STAGE WITH A FORECAST TO RISE TO 18.1
FEET...JUST UNDER A FOOT FROM FLOOD STAGE BY FRIDAY NIGHT.
ENSEMBLES ALSO KEEP THE THREAT OF RIVER FLOODING LOW WITH THE 18Z
GEFS SHOWING THE HIGHER PROBABILITY OF THE ENSEMBLES WITH A 30
PERCENT CHANCE THAT DANVILLE AND SOUTH BOSTON REACH FLOOD STAGE.
RIVER FORECAST CENTERS AND OUR OFFICE ARE FORECASTING LOWER.
&&
.EQUIPMENT...
AS OF 330 AM EST THURSDAY...
THE NOAA WEATHER RADIO AT RICHLANDS...WZ-2543...REMAINS DOWN.
TECHNICIANS ARE EXPECTED TO WORK ON THIS TODAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/WP
NEAR TERM...DS/WP
SHORT TERM...RCS
LONG TERM...PC
AVIATION...AMS/DS/WP
HYDROLOGY...PC/WP
EQUIPMENT...WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
654 AM EST THU DEC 17 2015
.SYNOPSIS...
A COLD FRONT CROSSES THE AREA TODAY WITH WIDESPREAD RAINFALL. THIS
FRONT WILL BE ALONG THE COAST BY FRIDAY MORNING. A STRONG UPPER
LEVEL TROUGH WILL BRING US BACK COLDER TEMPERATURES INTO THE
WEEKEND...BUT THIS WILL BE SHORT-LIVED. ANOTHER COLD FRONT WILL
MAKE ITS WAY TOWARDS THE REGION AND IMPACT THE AREA MONDAY INTO
TUESDAY OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 622 AM EST THURSDAY...
LATEST RADAR SHOWING BROAD AREA OF RAIN OVER MOST OF THE FORECAST
AREA. THE 11Z RAP MESOANALYSIS SHOWED BEST UPPER DIVERGENCE NOW
OVER SE WV EAST TO LYH-RIC. THERE IS SOME WEAKENING TO THE SOUTH
TO THE RAIN. AT THIS TIME...HRRR DEPICTING THINGS THE BEST. GIVEN
THIS...WILL STILL SEE GREATEST CONCENTRATION OF RAIN THROUGH EARLY
AFTERNOON...THEN SHOULD SEE A DRYING TREND IN THE WEST...AND
FASTER MOVING OUT THIS EVENING OF THE RAIN...SO SPED UP THE DRYING
WITH THIS UPDATE.
PREVIOUS DISCUSSION FROM EARLY THIS MORNING...
FRONTAL BOUNDARY EARLY THIS MORNING STRETCHES FROM A 990MB LOW
OVER THE NRN TIP OF LAKE SUPERIOR SOUTHWARD INTO CENTRAL KY/MID
TN...WITH A WEAK LOW PRESSURE WAVE OVER ERN KY ALONG A WARM
FRONTAL BOUNDARY. RADAR INDICATING LIGHT TO AT TIMES MODERATE RAIN
MOVING NNE ACROSS THE NC INTO SOUTHSIDE VA AND OVER WV/FAR SW VA.
MODELS IN AGREEMENT ON THE SYNOPTICS...THOUGH SOME DIFFERENCES ON
PLACEMENT OF HIGHER QPF...WITH THE NAM A LITTLE WEST OF THE
GFS/ECMWF.
EARLY THIS MORNING THE BEST UPPER DIVERGENCE WITH THE 140KT 300MB
JET WAS OVER ERN TN INTO THE NC PIEDMONT. THE GFS PICKED UP ON THIS
UPPER PATTERN WELL AND GENERALLY FOLLOWED ITS SOLUTION BLENDED WITH
THE ECMWF. THE QPF WILL BE HIGHEST ALONG AND EAST OF THE BLUE RIDGE
WHICH WE HAVE BEEN ADVERTISING THE PAST 2 DAYS. EXPECT THE RAIN TO
BE HEAVY AT TIMES TODAY IN ASSOCIATION WITH A STRONGER LOW LVL JET
MOVING IN FROM UPSTATE SC AT 7AM INTO THE VA/NC PIEDMONT BY NOON.
STRONG PRESSURE FALLS OVER THE MID ATLANTIC THIS AFTERNOON INDICATES
POTENTIAL FOR THAN ONE WAVE OF LOW PRESSURE TO FORM ALONG THE FRONT.
DIFFICULT TO SEE HOW SLOW AND HOW FAR WEST THE RAIN WILL LINGER INTO
THE PIEDMONT INTO EARLY EVENING...SO KEPT SOME HIGHER POPS EAST OF A
LYNCHBURG TO MARTINSVILLE LINE...THEN TAPER TO CHANCE BY MIDNIGHT.
EXPECT CATEGORICAL POPS AREA WIDE THROUGH MOST OF THE DAY WITH
DEEPER MOISTURE POISED TO MOVE OUT OF THE MOUNTAINS BY DUSK...THOUGH
LOW LVL MOISTURE REMAIN ACROSS THE WESTERN SLOPES THROUGH TONIGHT.
ALTHOUGH THE STORM PREDICTION CENTER HAS A GENERAL THUNDER RISK INTO
THE PIEDMONT...APPEARS THAT INSTABILITY IS NIL...AND MAINLY HAVING
STRONG JET DYNAMICS TO AID IN LIFT...SO ANY THUNDER WOULD BE PRESSED
FURTHER EAST TOWARD THE COAST WHERE THERE IS A BETTER ENVIRONMENT
FOR THAT THIS AFTERNOON. STILL SOME STRONGER CONVECTIVE ELEMENTS
COULD MOVE ACROSS THE PIEDMONT OF VA/NC THROUGH MID AFTERNOON.
RAINFALL AMOUNTS FROM EARLY THIS MORNING THROUGH THURSDAY EVENING
WILL RANGE FROM 1 TO 1.25 ALONG/EAST OF THE BLUE RIDGE WITH LOCALLY
HIGHER AMOUNTS POSSIBLE. WEST...EXPECT THREE QUARTERS TO AN INCH.
SEE HYDRO SECTION BELOW FOR COMMENTS ABOUT IMPACTS ON
STREAMS/RIVERS.
TEMPERATURES THIS MORNING WILL STAY STEADY OR SLOWLY RISE BUT WITH
RAINFALL MOVING IN...GOING TO SEE HIGHS HELD IN CHECK WITH LOWER TO
MID 50S MOST AREAS...AND UP TO 60 IN SOUTHSIDE VA INTO NW NC
PIEDMONT. STILL THIS ABOUT 5-10 DEGREES ABOVE NORMAL.
TONIGHT...AS THE 8H FRONT MOVES EAST...STRONGER COLD ADVECTION
SLIDES INTO THE MOUNTAINS. MOISTURE DEPTH OVERALL IS SUFFICIENT FOR
SOME LIGHT RAIN CHANGING TO SNOW SHOWERS AFTER MIDNIGHT...THOUGH
ACCUMULATION THROUGH DAWN IS GOING TO BE LITTLE/NONE. TEMPS MAY
STAY ELEVATED ACROSS THE PIEDMONT UNTIL A LATE DROP. AS SUCH HAVE
LOWS RANGING FROM THE LOWER 30S ACROSS THE WESTERN SLOPES TO MID
30S NEW RIVER VALLEY/BLUE RIDGE...UPPER 30S TO LOWER 40S ROANOKE
TO LYNCHBURG...AND FOOTHILLS...WITH MID TO UPPER 40S FROM
FARMVILLE TO YADKINVILLE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 249 AM EST THURSDAY...
A COLD FRONT WILL MOVE OFF THE EAST COAST FRIDAY SENDING
TEMPERATURES DOWN INTO THE 30S AND 40S FRIDAY AFTERNOON. SINCE THE
WEATHER HAS BEEN VERY WARM FOR THE LAST COUPLE OF WEEK...THIS DROP
IN TEMPERATURES WILL SEEM LIKE AN ARCTIC AIRMASS...BUT IN REALITY
TEMPERATURES WILL BE SEASONAL FOR ONCE. THOSE WHO ARE NOT FANS OF
COLD WEATHER WILL BE HAPPY WHEN WARMER THAN NORMAL TEMPERATURES
RETURN ON SUNDAY.
THROUGH THE DAY FRIDAY...85H TEMPERATURES WILL CONTINUE TO FALL AS
COLD AIR RUSHES IN ON NORTHWEST FLOW. HIGH TEMPERATURES FRIDAY WILL
LIKELY OCCUR DURING THE MORNING FOR THE MOUNTAINS AND EARLY
AFTERNOON IN THE PIEDMONT. DESPITE MORNING TEMPERATURES BEING IN THE
UPPER 30S TO LOWER 40S...WILL KEEP ANY MOUNTAIN PRECIPITATION AS
SNOW AS LOW LEVEL WARM BOUNDARY LAYER WILL BE SHALLOW. SOME SNOW
ACCUMULATIONS ARE POSSIBLE DURING THE DAY FRIDAY FOR THE HIGHER
ELEVATIONS OF SE WV ABOVE 3000 FEET. BELOW 3000 FEET...GROUND
TEMPERATURES SHOULD REMAIN WARM THROUGH THE DAY TO KEEP ANY
ACCUMULATION TO A DUSTING OR LESS ON ELEVATED SURFACES AND ONLY
ALONG WESTERN SLOPES. AROUND 400 PM INTO THE NIGHT...ACCUMULATIONS
CHANCES INCREASE ALONG HIGHER ELEVATIONS AND WESTERN SLOPES FROM SE
WV...MOUNTAIN EMPIRE AND GRAYSON HIGHLAND OF SW VA AND THE NC HIGH
COUNTY. THIS UPSLOPE EVENT IS LACKING MOISTURE AND ACCUMULATIONS MAY
AMOUNT TO AN INCH OR SO FROM DRY SNOW. THE UPPER LEVEL TROUGH PIVOTS
TO THE MID ATLANTIC COAST SATURDAY MORNING...ENDING THIS BRIEF
UPSLOPE EVENT. PRESSURE RISES BEHIND THE FRONT FRIDAY AND FRIDAY
NIGHT WILL ALSO BRING BREEZY AND GUSTY WINDS TO THE FORECAST AREA.
THIS WIND MAY BE ENOUGH TO PUSH FLURRIES TO THE BLUE RIDGE FRIDAY
AFTERNOON AND EVENING. WIND SPEEDS WILL BE BORDER-LINE FOR AN
ADVISORY FRIDAY...BUT THINK CLOUDS WILL LIMIT HIGHER SPEEDS FROM
MIXING TO THE GROUND. ANOTHER SURGE IN WINDS IS EXPECTED SATURDAY
BUT THE 85H JET IS WEAKER THAN FRIDAY. CONFIDENCE ON AREAL COVERAGE
FOR STRONG WINDS IS LOW TO ISSUE HEADLINES AT THIS TIME. HIGH
PRESSURE BUILDS IN FROM THE SOUTHWEST SATURDAY AFTERNOON TO RELAX
THE WINDS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 PM EST WEDNESDAY...
THE COOL DOWN LOOKS TO BE SHORT-LIVED AS UPPER HEIGHTS BEGIN TO
BUILD YET AGAIN ON SUNDAY WITH 850 TEMPS BOUNCING BACK TO +4C TO +8C
BY LATE IN THE DAY AND SURFACE TEMPS BACK SLIGHTLY ABOVE
CLIMO...REACHING UPPER 40S NW TO LOW 50S SE. CLOUDS BEGIN TO
INCREASE FROM LATE SUNDAY INTO MONDAY AS THE SURFACE RIDGE MOVES
OFF THE EAST COAST AND TAKES UP RESIDENCE OVER THE WESTERN
ATLANTIC. A COOL FRONT ASSOCIATED WITH A GREAT LAKES LOW WILL
APPROACH THE REGION BUT THEN BECOMES RATHER DIFFUSE AND POORLY
ORGANIZED INTO TUESDAY AS HEIGHTS BUILD OFF THE EAST COAST AND
ANOTHER WESTERN TROUGH BEGINS TO DEVELOP. WILL SEE GRADUAL UPSWING
IN TEMPS/POPS THROUGH THE MID- WEEK PERIOD AS SW FLOW ALOFT BRINGS
WARMTH/MOISTURE NORTHWARD. SHOULD SEE VERY MILD HIGHS IN THE 50S
AND 60S AND LOWS MAINLY IN THE 40S OR EVEN LOW 50S. THESE NUMBERS
ARE ROUGHLY 10 TO 15F ABOVE NORMAL AND WILL KEEP US ON TRACK FOR
WHAT COULD BE A RECORD- BREAKING WARM DECEMBER. THROUGH MID-MONTH
(DEC. 1-15) ALL 5 CLIMATE SITES ARE IN THE TOP 5 ALL-TIME AND
BLUEFIELD IN 1ST PLACE (SINCE 1959). COULD ALSO SEE MODERATE TO
POSSIBLY HEAVY RAINFALL DURING MUCH OF THIS PERIOD...UP TO AN INCH
OR MORE POSSIBLE...BUT FOCUS FOR HEAVIEST RAINS STILL APPEARS TO
BE FURTHER TO THE SOUTHWEST ALONG THE GULF COAST.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 640 AM EST THURSDAY...
CIGS THIS MORNING VARY FROM IFR TO VFR WITH LIGHT TO MODERATE RAIN
MOVING ACROSS. MAJORITY OF THE DAY WILL SEE RAIN WITH MVFR OR
LOWER CIGS/VSBYS AT ALL SITES. HIGH RES MODELS BRING AN END TO THE
RAIN IN THE LWB/BLF AREA BY 20Z...BCB/ROA BETWEEN 21-00Z...AND
EAST OF LYH/DAN BY 00-01Z. WINDS WILL SHIFT FROM VARIABLE TO SOUTH
THIS MORNING THEN AS THE FRONT MOVES ACROSS TO THE WNW. WINDS WILL
STAY AROUND 10KTS OR LESS. A STRONG LOW LVL JET MOVES ACROSS THIS
MORNING MAINLY EAST OF THE BLUE RIDGE SO LOW LVL WIND SHEAR WAS
KEPT IN LYH/DAN/BCB AROUND 15-19Z.
ONCE THE WINDS SHIFT AROUND TO THE WEST ANTICIPATE CIGS TO LIFT TO
VFR THIS EVENING ROA/LYH/DAN AND BY 06Z AT BCB...WHILE BLF/LWB
KEEP MVFR/IFR CIGS AROUND 1KFT THROUGH THE NIGHT. ATTM...LEFT OUT
SNOW SHOWERS OR DRIZZLE AS MOISTURE AT LWB/BLF LOOKS LACKING.
.EXTENDED AVIATION DISCUSSION...
GUSTY NORTHWEST WINDS FRIDAY INTO FRIDAY NIGHT ON THE BACKSIDE OF
THE DEPARTING SYSTEM WILL KEEP UPSLOPE IFR/MVFR CLOUDS AND
ISOLATED RAIN OR SNOW SHOWERS ACROSS THE MOUNTAINS...ESPECIALLY
PARTS OF SOUTHEAST WEST VIRGINIA INTO THE NORTHERN MOUNTAINS OF
NORTH CAROLINA. SNOW SHOWERS ALONG WITH MVFR CEILINGS ARE LIKELY
IN SOUTHEAST WEST VIRGINIA ON FRIDAY AND SATURDAY.
THE PRESSURE GRADIENT WILL SLACKEN SATURDAY NIGHT INTO SUNDAY AS
THE CENTER OF HIGH PRESSURE BUILDS INTO THE REGION. THIS WILL ALSO
BRING AN END TO UPSLOPE CLOUDS AND LIGHT PRECIPITATION. VFR
CONDITIONS ARE EXPECTED SUNDAY.
BY LATE SUNDAY NIGHT INTO MONDAY...THE NEXT COLD FRONT WILL BE ON
OUR WESTERN EDGES OF THE FORECAST AREA. LOOK FOR A RETURN OF MVFR
CLOUD COVER...STRONGER LOW LEVEL WINDS...AND PRECIPITATION WITH
THE APPROACH AND PASSAGE OF THIS FRONT.
&&
.HYDROLOGY...
AS OF 300 AM THURSDAY...
FORECAST RAINFALL AMOUNTS OF THREE QUARTERS TO 1.5 INCHES WILL
BRING RISES ON THE SMALLER CREEKS AND STREAMS LATER TODAY BUT
OVERALL THE THREAT OF FLOODING WILL BE LOW. STILL CANNOT RULE OUT
SOME HIGHER RAINFALL RATES THAT COULD BRING PONDING OF WATER OR
POOR DRAINAGE FLOODING TO URBAN AREAS...BUT THIS DOES NOT WARRANT
A FLOOD WATCH.
IMPACTS ON THE MAIN STEM RIVERS INTO FRIDAY TO SATURDAY SHOWS ONLY
SOUTH BOSTON REACHING ACTION STAGE WITH A FORECAST TO RISE TO 18.1
FEET...JUST UNDER A FOOT FROM FLOOD STAGE BY FRIDAY NIGHT.
ENSEMBLES ALSO KEEP THE THREAT OF RIVER FLOODING LOW WITH THE 18Z
GEFS SHOWING THE HIGHER PROBABILITY OF THE ENSEMBLES WITH A 30
PERCENT CHANCE THAT DANVILLE AND SOUTH BOSTON REACH FLOOD STAGE.
RIVER FORECAST CENTERS AND OUR OFFICE ARE FORECASTING LOWER.
&&
.EQUIPMENT...
AS OF 330 AM EST THURSDAY...
THE NOAA WEATHER RADIO AT RICHLANDS...WZ-2543...REMAINS DOWN.
TECHNICIANS ARE EXPECTED TO WORK ON THIS TODAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/WP
NEAR TERM...WP
SHORT TERM...RCS
LONG TERM...PC
AVIATION...AMS/DS/WP
HYDROLOGY...PC/WP
EQUIPMENT...WP
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
357 AM MST THU DEC 17 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM MST THU DEC 17 2015
WEBCAMS SHOW SNOW CONTINUING TO FALL FROM RAWLINS TO THE ARLINGTON
AREA WITH VIS MOSTLY IN THE ONE TO TWO MILE RANGE. SNOTELS IN THE
SIERRA MADRE AND SNOWY RANGES SHOW AROUND 4-6 INCHES OF SNOW HAS
FALLEN SINCE LAST AFTERNOON. THE WINTER WEATHER ADVISORIES LOOK ON
TRACK RIGHT NOW. THE SHORTWAVE RESPONSIBLE FOR THE SNOW TO THE
WEST OF THE LARAMIE RANGE WILL SLIDE SOUTHEASTWARD INTO COLORADO
BY MIDDAY. THE BEST FORCING WILL QUICKLY EXIT THE CWA AFTER 15-18Z
WITH THE SNOW LARGELY COMING TO AN END. WILL KEEP SNOW
ACCUMULATIONS GENERALLY LESS THAN 1-2 INCHES OVER LOWER ELEVATIONS
OF SOUTHEAST WYOMING. WIND GUSTS IN THE ARLINGTON AREA HAVE
DROPPED TO AROUND 25 MPH SO NOT EXPECTING MUCH BLOWING SNOW
THROUGH THE MORNING AS THE GRADIENT IS RATHER WEAK. IT WILL BE
QUITE COLD BEHIND THE MORNING FROPA WITH HIGHS STRUGGLING TO GET
OUT OF THE 20S.
ATTENTION TONIGHT THEN TURNS TO THE HIGH WIND EVENT THAT WILL
OCCUR IN THE WIND PRONE AREAS OF SOUTHEAST WY. HEIGHTS RISE
OVERNIGHT WITH WARM AIR ADVECTION. A CROSS SECTION OVER THE WIND
PRONE AREAS SHOWS A PRONOUNCED INVERSION A FEW THOUSAND FEET ABOVE
THE SFC. THE LLVL GRADIENT IS PRETTY IMPRESSIVE...RISING QUICKLY
TO 70-75 METERS BY LATE TONIGHT. THUS...CONFIDENCE WAS THERE TO
UPGRADE THE HIGH WIND WATCH TO A WARNING FOR THE WIND PRONE AREAS
AND LARAMIE VALLEY. THE CAG-CPR GRADIENT DOES DECREASE BELOW 55
METERS BY FRI AFTN SO HIGH WINDS WILL LIKELY BE ON THE DECREASE
ESPECIALLY BY THE EVENING.
STILL CONCERNED ABOUT BLOWING SNOW TONIGHT AS THE OFFICE BLOWING
SNOW MODEL IS GIVING REALLY HIGH PROBABILITIES AT ARLINGTON AND
THE SOUTHERN LARAMIE RANGE THROUGH MID MORNING FRIDAY. THE
SNOWPACK HAS LIKELY BECOME MORE COMPACT OVER THE PAST DAY AND THIS
MORNINGS SNOW WILL BE A FEW INCHES AT BEST. STILL WITH GUSTS TO
60-65 MPH...THERE WILL LIKELY BE AREAS OF BLOWING SNOW ALONG
INTERSTATE 80 FROM CHEYENNE TO RAWLINS...CREATING TRAVEL CONCERNS.
SAW REDUCTIONS IN VIS TO AROUND THREE QUARTERS OF A MILE YESTERDAY
WITH GUSTS TO 50 MPH OVER THE SUMMIT. MENTIONED THE BLOWING SNOW
THREAT IN THE HIGH WIND WARNING. THE BLOWING SNOW THREAT WILL END
AFTER MIDDAY AS THE TEMPS MOSTLY WARM TO ABOVE FREEZING.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 300 AM MST THU DEC 17 2015
GOING TO STAY WINDY AT LEAST THROUGH SATURDAY NIGHT BEFORE WINDS
EASE. GFS 700MB WINDS OF 45 TO 55KTS WITH 700MB CRAIG TO CASPER
HEIGHT GRADIENTS CLOSE TO 60MTRS. WILL PROBABLY NEED WIND
HEADLINES FOR THE WIND PRONE AREAS THROUGH SATURDAY NIGHT.
BY SATURDAY NIGHT INTO SUNDAY...OUR NEXT SHORTWAVE BEGINS TO MOVE
INTO THE AREA. GFS HAS MORE WIDESPREAD QPF OVER THE CWFA THAN THE
ECMWF HAS. BOTH THOUGH SHOW THE MAIN ENERGY WITH THIS SYSTEM OVER
COLORADO...SO CONFINED POPS TO OUR WESTERN MOUNTAINS FOR THE MOST
PART.
ANOTHER WIND EVENT SUNDAY NIGHT INTO MONDAY AS 700MB WINDS
INCREASE TO 60KTS. WINDS STAY UP THROUGH THE MIDDLE OF NEXT WEEK
BEFORE ANOTHER SHORTWAVE MOVES THROUGH. PERSISTENT SHOWERS OVER
THE SNOWY AND SIERRA MADRE RANGES. THEY COULD BE LOOKING AT A LOT
OF SNOW UP THERE THROUGH THE LONG TERM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 354 AM MST THU DEC 17 2015
LATEST RADAR IMAGERY SHOWING AREA OF SNOW JUST NORTH OF CHEYENNE
OUT TO KIMBALL NEBRASKA THIS MORNING. DO BELIEVE WE WILL SEE
IMPACTS FROM THIS SNOW AT KCYS AND EVENTUALLY IN THE PANHANDLE FOR
A TIME THIS MORNING. HRRR SHOWING IFR/LIFR CONDITIONS FOR SOME
AIRPORTS IN THE PANHANDLE THROUGH 16Z TODAY. BASICALLY MIRRORED
ITS SOLUTION IN OUR 12Z TAFS. SNOW TO END AFTER 16Z WITH STRONG
WINDS DEVELOPING AT KRWL AND KLAR LATER TODAY.
&&
.FIRE WEATHER...
ISSUED AT 224 AM MST THU DEC 17 2015
NO FIRE WEATHER CONCERNS THROUGH THE WEEKEND. STRONG WINDS WILL
DEVELOP IN THE WIND PRONE AREAS TONIGHT INTO FRIDAY AFTERNOON.
MINIMUM AFTERNOON HUMIDITY VALUES WILL GENERALLY BE GREATER THAN
40 PERCENT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER WEATHER ADVISORY UNTIL 8 AM MST THIS MORNING FOR WYZ112-
114.
HIGH WIND WARNING FROM 5 PM THIS AFTERNOON TO 3 PM MST FRIDAY
FOR WYZ106-110-116-117.
WINTER WEATHER ADVISORY UNTIL 5 AM MST EARLY THIS MORNING FOR
WYZ110.
HIGH WIND WARNING FROM 11 PM THIS EVENING TO 3 PM MST FRIDAY FOR
WYZ115.
NE...NONE.
&&
$$
SHORT TERM...ZF
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...ZF
AREA FORECAST DISCUSSION
NWS ALBANY NY
400 PM EST THU DEC 17 2015
.SYNOPSIS...
AS A FRONTAL SYSTEM MOVES ACROSS THE AREA...STEADY LIGHT
RAINFALL WILL TAPER OFF BY LATE THIS EVENING. SOMEWHAT COOLER
TEMPERATURES...ALONG WITH A LINGERING SHOWER IN SPOTS...WILL BE IN
PLACE FOR FRIDAY. MORE SEASONABLE TEMPERATURES...ALONG WITH SOME
LAKE EFFECT SNOW SHOWERS AND SQUALLS...WILL ARRIVE FOR THE
WEEKEND...ALTHOUGH TEMPERATURES WILL RETURN ABOVE NORMAL NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS OF 400 PM EST...OUR REGION REMAINS IN BROAD SW FLOW
ALOFT...WITH A LARGE TROUGH OVER THE CENTRAL PART OF THE US AND
RIDGING OFF THE EASTERN SEABOARD. PLENTY OF MOISTURE HAS BEEN
STREAMING UP THE COAST...EXTENDING BACK ALL THE WAY FROM THE
PACIFIC OCEAN.
A SFC COLD FRONT IS IN THE PROCESS OF SLOWLY MOVING EASTWARD
TOWARDS THE AREA. A WAVE OF LOW PRESSURE IS LOCATED ALONG THIS
BOUNDARY OVER THE MID ATLANTIC REGION. AS SHOW IN THE REGIONAL
MOSAIC RADAR...STEADY LIGHT RAIN IS ONGOING ACROSS THE ENTIRE CWA
THIS AFTERNOON. AS THE WHOLE FRONTAL SYSTEM SHIFTS EASTWARD AND
THE LOW PRESSURE AREA RIDES UP THE BOUNDARY...THIS RAINFALL LOOKS
TO CONTINUE THROUGH THE EVENING HOURS. RAINFALL RATES ARE
GENERALLY LIGHT /MAINLY 0.10 OF AN INCH OR LESS PER HOUR/ ALTHOUGH
THERE HAVE BEEN A FEW BRIEF MODERATE BURSTS IN SOME AREAS AT
TIMES.
THE 19Z RUN OF THE 3KM HRRR SUGGEST RAINFALL SHOULD BE TAPERING
OFF FROM SOUTHWEST TO NORTHEAST BETWEEN 8 PM AND 11 PM...WITH JUST
A FEW LINGERING RAIN SHOWERS FOR THE REMAINDER OF THE OVERNIGHT
HOURS FOR THE HIGH TERRAIN AREAS /MAINLY FOR THE WESTERN
ADIRONDACKS/. AS THE FRONT SHIFTS EASTWARD...THE BULK OF THE DEEP
MOISTURE WILL ALSO MOVE AWAY FROM THE REGION AND SOME PARTIAL
CLEARING IS POSSIBLE LATE TONIGHT. WITH WESTERLY FLOW TAKING
OVER...THERE COULD BE SOME AREAS OF DRIZZLE IN UPSLOPE FAVORED
AREAS OF THE WESTERN ADIRONDACKS. TEMPS SHOULD REMAIN ABOVE
FREEZING FOR MOST OF THE NIGHT...BUT CANNOT RULE OUT AN ISOLATED
PATCH OF FREEZING DRIZZLE IN THE WESTERN ADIRONDACKS BY LATE
TONIGHT AS TEMPS DROP TO NEAR FREEZING. ELSEWHERE...OVERNIGHT LOWS
WILL FALL TO THE MID 30S TO LOW 40S BY DAYBREAK FRIDAY.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
LAKE EFFECT SNOW WATCH NOW IN EFFECT FOR NORTHERN HERKIMER COUNTY
FOR FRIDAY NIGHT THROUGH LATE SATURDAY NIGHT.
FRIDAY WILL BE A TRANSITION DAY FOR THE REGION. ALTHOUGH OUR AREA
WILL BE IN THE WAKE OF THE COLD FRONT...THE CORE OF THE UPPER
LEVEL TROUGH WILL STILL BE UPSTREAM OF THE AREA OVER THE GREAT
LAKES. COLD ADVECTION WILL BE ONGOING ALOFT...ESP BY THE AFTN
HOURS. MOST AREAS LOOK TO REMAIN DRY WITH A PARTLY TO MOSTLY
CLOUDY SKY. THERE COULD BE A RAIN OR SNOW SHOWER FOR FAR WESTERN
AREAS...ESP BY AFTN...AS THE UPPER LEVEL TROUGH AXIS STARTS TO
APPROACH AND TEMPS ALOFT COOL OFF ENOUGH TO ALLOW LAKE EFFECT TO
BEGIN.
WITH THE UPPER LEVEL TROUGH MOVING OVERHEAD FOR FRIDAY
NIGHT...TEMPS ALOFT WILL CRASH. 850 HPA TEMPS WILL FALL TO -10 TO
-12 DEGREES C BY SATURDAY MORNING. MEANWHILE...WITH WATER TEMPS ON
LAKE ONTARIO STILL AROUND +7 TO +8 DEGREES C...THERE WILL PLENTY
OF A TEMP DIFFERENTIAL TO ALLOW LAKE EFFECT SNOW TO OCCUR. WITH A
MULTI-LAKE CONNECTION IN PLACE...INVERSION HEIGHT ALL THE WAY UP
TO 600 HPA....AND WIND ORIENTATION TO REMAIN FAIRLY STEADY
/GENERALLY 280 TO 285 DEGREES FOR THE 0-3 KM LAYER/...A BAND OF
STEADY LAKE EFFECT SNOW LOOKS TO IMPACT THE TUG HILL PLATEAU INTO
THE WESTERN ADIRONDACKS FOR FRIDAY NIGHT THROUGH MUCH OF THE DAY
ON SATURDAY. AREAS AROUND OLD FORGE CAN EXPECT AT LEAST 6 INCHES
OF SNOW...AND AREAS THAT REMAIN UNDER THE CORE OF THE BAND WILL
HAVE THE POTENTIAL TO SEE OVER 9 INCHES. AS A RESULT...A LAKE
EFFECT SNOW WATCH HAS BEEN ISSUED FOR NORTHERN HERKIMER COUNTY.
THE KVIE INLAND EXTENT TOOL AVAILABLE THANKS TO CSTAR RESEARCH
SUGGESTS THE LAKE BAND COULD REACH AS FAR AS 120 MILES INLAND FROM
THE LAKESHORE WITH A MULTI LAKE CONNECTION IN PLACE...SO THERE/S
THE POTENTIAL FOR THE BAND TO REACH INTO THE CENTRAL ADIRONDACKS. WILL
MENTION THE POTENTIAL IN THE HWO FOR LAKE EFFECT HEADLINES TO BE
NEEDED INTO HAMILTON COUNTY AS WELL.
OUTSIDE OF THE LAKE EFFECT SNOW BAND...THERE WILL BE SOME PASSING
CLOUDS FROM TIME TO TIME. TEMPS LOOK TO FALL INTO THE 20S ON
FRIDAY NIGHT FOR THE FIRST NIGHT IN OVER A WEEK. OUTSIDE OF LAKE
EFFECT...MOISTURE WILL BE LIMITED...BUT WITH THE COLD AIR
ALOFT...CANNOT RULE OUT SOME ADDITIONAL SNOW SHOWERS OR FLURRIES
OVER THE REMAINDER OF THE AREA FOR FRI NIGHT INTO SATURDAY...ESP
FOR THE MOHAWK VALLEY...CATSKILLS...AND UPSLOPE AREAS OF THE
TACONICS/WESTERN NEW ENGLAND. UPSLOPE AREAS...ESP IN SOUTHERN
VERMONT...WILL HAVE THE POTENTIAL FOR 1-3 INCHES OF SNOW FRI NIGHT
INTO SAT WITH THE PERSISTENT WESTERLY FLOW. ALSO...WILL NEED TO
ALSO MONITOR THE POTENTIAL FOR SOME SNOW SQUALLS FOR DURING THE
DAY SATURDAY DUE TO THE DECENT INSTABILITY IN PLACE...ALTHOUGH THE
LACK OF A SFC ARCTIC BOUNDARY TO PROVIDE STRONG CONVERGENCE AND
SMALL AMOUNTS OF LOW LEVEL MOISTURE DUE TO THE GOOD MIXING WILL BE
A LIMITING FACTOR IN KEEPING THE COVERAGE ISOLD TO SCATTERED.
HIGHS ON SATURDAY WILL BE IN THE UPPER 20S TO UPPER 30S ACROSS THE
AREA. WHILE THESE TEMPS ARE CLOSE TO NORMAL...IT WILL FEEL MUCH
COLDER DUE TO THE RECENT WARM WEATHER AND BREEZY CONDITIONS. IN
FACT...WINDS MAY BECOME RATHER GUSTY FOR SATURDAY DUE TO THE
DECENT MIXING IN PLACE. WEST WINDS WILL BE 10 TO 20 MPH...AND SOME
GUSTS MAY REACH 25-35 MPH AT TIMES...ESP FOR THE HIGH TERRAIN AND
AREAS THAT CHANNEL WESTERLY FLOW.
THE LAKE BAND WILL FINALLY BE SHIFTING SOUTHWARD OUT OF THE
WESTERN ADIRONDACKS FOR SAT EVENING AND MAY IMPACT THE WESTERN
MOHAWK VALLEY FOR SAT NIGHT. A FEW INCHES OF SNOW MAY BE POSSIBLE
FOR SOUTHERN HERKIMER COUNTY...SO WILL MENTION THIS POTENTIAL
IN THE HWO AS WELL. CANNOT RULE OUT A LAKE ENHANCED SNOW SHOWER
MAKING ITS WAY DOWN THE MOHAWK VALLEY TOWARDS THE CAPITAL REGION
AS WELL. OTHERWISE...IT LOOKS SEASONABLE WITH LOWS IN THE LOW TO
MID 20S AND A PARTLY TO MOSTLY CLOUDY SKY.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
THE EXTENDED BEGINS WITH SEASONABLY CHILLY TEMPERATURES ON SUNDAY.
ANY LAKE EFFECT ON SUNDAY SHOULD BEGIN SHUTTING DOWN AS
THE FLOW BEGINS TO BACK TO A MORE SOUTHWESTERLY FLOW
ALOFT...AND THE SUBSIDENCE INVERSION LOWERS.
IT LOOKS TO BE MAINLY DRY ON SUNDAY WITH A PARTLY TO MOSTLY SUNNY
SKY AND TEMPERATURES RANGING FROM AROUND 30 IN OUR NORTHWESTERN
AREAS...TO AROUND 40 IN OUR SOUTHEASTERN ZONES...LOCALLY UPPER 30S
IN THE CAPITAL REGION.
AFTER SUNDAY...THE BROAD UPPER LEVEL RIDGE WHICH HAS BEEN PERSISTENT
ACROSS THE EASTERN CONUS FOR THE PAST TWO MONTHS...LOOKS TO DEVELOP
ONCE MORE...AS HEIGHTS BEGIN TO RISE AND WILL CONTINUE TO DO SO
THROUGH THE REMAINDER OF THE EXTENDED PERIOD.
SURFACE HIGH PRESSURE WILL BUILD OFFSHORE...CREATING AN INCREASINGLY
MILD AS WELL AS MOIST SOUTHWESTERLY FLOW. THE LEADING EDGE OF WARMER
AIR WILL COULD PRODUCE A ROUND OF LIGHT PRECIPITATION ON MONDAY.
INITIALLY IT MIGHT BE JUST COLD ENOUGH FOR THIS PRECIPITATION TO
BEGIN AS A LITTLE SNOW OR A WINTRY MIX...ESPECIALLY IF IT ARRIVES
EARLY ON MONDAY. HOWEVER...ANY WINTRY MIX SHOULD CHANGE TO ALL RAIN
AS TEMPERATURES EVEN ON MONDAY WILL NUDGE UP TO THE UPPER 30S TO MID
40S.
AFTER THIS FIRST THRUST OF WARM AIR ADVECTION...TIMING OF SPECIFIC
DISTURBANCES WILL BE DIFFICULT IN THE INCREASINGLY MOIST
SOUTHWESTERLY FLOW. WHILE SOME OF THE TIME TUESDAY THROUGH EARLY
THURSDAY COULD ACTUALLY BE RAIN FREE...THERE LOOKS TO BE PLENTY OF
CLOUDS AROUND AND PERHAPS AREAS OF DRIZZLE. ANOTHER DISTINCT
DISTURBANCE (A SECONDARY WARM FRONT) LOOKS TO LIFT NORTHWARD
SOMETIME ON WEDNESDAY SO WE INCREASED CHANCES TO AROUND 50 PERCENT.
A COLD OR OCCLUDED FRONT LOOKS TO WORK ACROSS THE REGION ON
THURSDAY WITH MORE OPPORTUNITY FOR SHOWERS.
THE BIG THEME FOR THE EXTENDED (ESPECIALLY FROM TUESDAY ON) WILL BE
A RETURN TO UNSEASONABLE MILD TEMPERATURES. EVEN WITH
CLOUDS...PATCHY DRIZZLE AND THE CHANCE FOR SHOWERS...TEMPERATURES
LOOK TO REACH THE MID 40S TO MID 50S REGION WIDE ON TUESDAY AND
WEDNESDAY...AND WELL INTO THE 50S ON WEDNESDAY AND
THURSDAY...POSSIBLY EVEN TOUCHING AROUND 60 SOUTH OF ALBANY BY LATE
THURSDAY.
THE CLOUDS AND A SOUTHERLY BREEZE WILL KEEP TEMPERATURES ABOVE
FREEZING MONDAY NIGHT THROUGH WEDNESDAY NIGHT...LOWS IN THE
30S AND EVEN 40S (ESPECIALLY WEDNESDAY NIGHT).
THE AVERAGE TEMPERATURES DURING THE EXTENDED PERIOD WILL LIKELY BE
AT LEAST 10 TO 15 DEGREES ABOVE NORMAL TEMPERATURES EVERYWHERE IN
OUR REGION.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AN APPROACHING LOW PRESSURE SYSTEM WILL BRING WIDESPREAD RAINFALL
TO THE REGION THIS AFTERNOON AND EARLY EVENING. WITH A MOIST
SOUTHEAST LOW LEVEL FLOW IN PLACE...BORDERLINE IFR CIGS ARE
OCCURRING AT KALB/KPSF/KPOU AS OF MIDDAY...WITH LOWERING TRENDS
EXPECTED AS THE AFTERNOON PROGRESSES.
A STEADY RAIN HAS ALREADY DEVELOPED AT KPOU...AND SHOULD OVERSPREAD
THE REMAINDER OF THE TAF SITES THROUGH 20Z. THEN...EXPECT A STEADY
LIGHT TO MODERATE RAIN THROUGH AT LEAST 00Z-04Z/FRI...BEFORE
TAPERING OFF FROM SOUTHWEST TO NORTHEAST. MAINLY IFR/LIFR CONDITIONS
ARE EXPECTED THROUGH THIS TIME...BOTH FOR CIGS AND VSBYS.
CONDITIONS SHOULD SLOWLY IMPROVE AFTER 04Z/FRI...ALTHOUGH FOG/LOW
CIGS MAY DEVELOP AFTER THE STEADY RAIN ENDS AT KPOU FOR AT LEAST A
FEW HOURS. BY DAYBREAK...EXPECT MAINLY MVFR TO VFR CIGS...WITH VFR
VSBYS.
WINDS THIS AFTERNOON WILL BE MAINLY SOUTH-SOUTHEAST AROUND 4-11
KTS...WITH SOME LOCALLY HIGHER GUSTS AT KALB. WINDS MAY BECOME
LIGHT/VARIABLE FOR SEVERAL HOURS THIS EVENING...BEFORE SHIFTING INTO
THE WEST TO NORTHWEST AT 5-10 KT AFTER MIDNIGHT INTO FRIDAY MORNING.
SOME SLIGHTLY HIGHER GUSTS OF 15-20 KT COULD OCCUR BY MID MORNING
FRIDAY AT KALB AND KPSF.
OUTLOOK...
FRIDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SATURDAY: MODERATE OPERATIONAL IMPACT. BREEZY CHANCE OF SHSN.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
SUNDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
&&
.HYDROLOGY...
STEADY LIGHT RAIN WILL CONTINUE THROUGH THE LATE EVENING HOURS.
ADDITIONAL PRECIP AMOUNTS LOOK TO BE A QUARTER TO A HALF INCH.
THIS RAINFALL WILL ALLOW FOR SOME SMALL RISES ON RIVERS AND
STREAMS...BUT ALL WATERWAYS ARE EXPECTED TO REMAIN WELL WITHIN
THEIR BANKS.
A FEW LINGERING SHOWERS ARE POSSIBLE FRIDAY...WITH SOME ADDITIONAL
LAKE EFFECT SNOW SHOWERS FRIDAY NIGHT INTO SATURDAY. ANY OF THIS
ADDITIONAL PRECIP WILL BE MAINLY SCATTERED IN NATURE AND FAIRLY
LIGHT...AND WILL HAVE LITTLE TO NO IMPACT ON AREA STREAMS AND
RIVERS.
DRY WEATHER WILL RETURN BRIEFLY FOR SUNDAY...WITH ANOTHER CHANCE
FOR LIGHT RAIN SHOWERS EARLY NEXT WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...LAKE EFFECT SNOW WATCH FROM FRIDAY EVENING THROUGH SUNDAY
MORNING FOR NYZ032.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...HWJIV
AVIATION...KL/JPV
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
100 PM EST THU DEC 17 2015
.SYNOPSIS...
LOW PRESSURE AND A COLD FRONT WILL MOVE ACROSS OUR AREA LATE TODAY
AND EARLY TONIGHT. A STRONG AREA OF HIGH PRESSURE BUILDS TO OUR SOUTH
AND WEST FRIDAY AND SATURDAY, THEN BRIEFLY SETTLES OVER OUR REGION
SUNDAY BEFORE MOVING OFFSHORE. A WEAK COLD FRONT WILL APPROACH ON
TUESDAY, HOWEVER IT MAY STALL JUST TO OUR WEST BEFORE ANOTHER COLD
FRONT APPROACHES LATE WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RAIN HAS ARRIVED AND VERY LITTLE CHANGE TO TIMING MADE WITH THE
AFTERNOON UPDATE, PERHAPS LINGERING INTO THE EARLY EVENING. TEMPERATURES
WERE RAISED A HAIR BOTH NOW AND WITH THE HIGH TEMPERATURES,
THOUGH EVAPORATIONAL COOLING WILL KEEP TEMPERATURES FROM RISINGTO
MUCH.
PREVIOUS DISCUSSION. RAIN HAS BEEN POPPED PER HRRR ONSET 12Z- 15Z
E PA THIS MORNING... DELAYED SLIGHTLY FROM EARLIER FORECASTS THEN
ROBUST 3-6 HR PERIOD OF SHOWERY RAINS MIDDAY/MID AFTN EVERYWHERE.
SOME OF THE RAIN WILL BE BRIEFLY HEAVY NEAR THE PATH OF THE SFC
LOW IN THE SLIGHTLY MORE UNSTABLE AIR AND THAT SHOULD BE NJ/DE AS
PER THE WPC QPF. MOST OF THE RAIN IN THE 15Z-22Z TIME FRAME.
QPF GENERALLY .3 TO .8 INCHES WITH A FEW 1.25 INCH AMOUNTS
POSSIBLE, ESPECIALLY NJ/DE. HWO FB AND TWEET HAS THE HEAVY RAIN
HAZARD.
SE WIND BRIEFLY INCREASES DURING MIDDAY WITH GUSTS 20 MPH S NJ
COAST AS WELL AS DELAWARE, WHILE THE WIND IN E PA MAY TURN LIGHT
NE. A WIND SHIFT EVERYWHERE TO SOUTHWEST OR WEST LATE IN THE DAY
WITH LOW PRES AND A BROAD CFP PASSING THROUGH AND THEN EAST OF OUR
COASTS.
FOG IN THE FORECAST THIS AFTN IN THE BROAD PATH OF LOW PRES AND A
WEAK GRADIENT, ESPECIALLY SUNSET ONWARD WHEN DRY SLOT PASSES THROUGH
ALOFT. SOME OF THAT FOG COULD BE DENSE AND FORESEE A SPS POTENTIAL
FOR FOG LATE IN THE DAY.
FORECAST ELEMENTS WERE DERIVED FROM A 50 50 BLEND OF THE 00Z/17
GFS/NAM MOS. HOWEVER, BECAUSE OF WETBULBING AND RAIN, I BLENDED
THE TEMPS WITH THE COOLER NAM 2 M TEMPS. CONFIDENCE ON LOWERING
TEMPS FROM GUIDANCE I-95 NWWD IS ONLY AVERAGE.
AS FOR CLIMO...MAX TEMPS ABOUT 10F ABOVE NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
PROBABLY PATCHY FOG, POSSIBLY DENSE ALONG AND SE OF I-95 DURING THE
EVENING. LEFTOVER SHOWERS ALONG THE COASTS DURING THE EVENING.
DOUBTING IF ANY MEASURABLE RAIN AFTER MIDNIGHT. OTRW...MO CLOUDY.
WIND BECOMING NORTHWEST AND INCREASING AFTER MIDNIGHT WHEN THE
DEWPOINTS TUMBLE AND VSBY IMPROVES CONSIDERABLY.
FORECAST ELEMENTS WERE DERIVED FROM A 50 50 BLEND OF THE 00Z/17
GFS/NAM MOS.
CLIMO: LOWS ABOUT 15F WARMER THAN NORMAL.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF AN AMPLIFIED UPPER-LEVEL TROUGH
SETTLING INTO THE EAST FRIDAY NIGHT AND SATURDAY BEFORE LIFTING
NORTHEASTWARD SUNDAY. THIS DELIVERS MUCH COLDER AIR INTO THE EAST,
HOWEVER THE FLOW IS PROGRESSIVE AND THEREFORE THE COLD SHOT IS SHORT
IN DURATION. AS ENERGY ACROSS THE WEST MOVES INTO THE CENTRAL PLAINS
LATER IN THE WEEKEND, RIDGING RETURNS ACROSS THE EAST. THIS WILL
ALLOW A WARMING TREND TO OCCUR NEXT WEEK, WITH POTENTIALLY NEAR
RECORD WARMTH STARTING ON WEDNESDAY. THE MAIN WEATHER FEATURE IS A
FRONTAL ZONE WITH WAVES OF LOW PRESSURE ALONG IT OFFSHORE FRIDAY
NIGHT, THEN A POTENTIALLY SLOW MOVING FRONT ARRIVING TUESDAY INTO
THURSDAY. WE USED A MODEL BLEND FRIDAY THROUGH SUNDAY, THEN A 00Z
WPC/CONTINUITY BLEND THEREAFTER. SOME ADJUSTMENTS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.
FOR FRIDAY...THERE SHOULD BE GRADUAL CLEARING AS THE FRONT AND
SURFACE WAVE IS OFFSHORE, HOWEVER SOME OVERRUNNING WEST OF THE
BOUNDARY AS ANOTHER LOW RUNS UP THE FRONT COULD LINGER SOME SHOWERS
NEAR THE COAST IN THE MORNING. OVERALL THOUGH THE BULK OF THE
PRECIPITATION SHOULD REMAIN OFFSHORE, THEREFORE HELD ONTO SOME
SLIGHT CHC TO LOW CHC POPS IN THE MORNING MAINLY FROM THE COAST ON
EASTWARD. CAA ARRIVES THROUGH THE DAY AND REALLY KICKS IN BY LATE IN
THE DAY. THERE IS THE POTENTIAL FOR SOME FLURRIES OR SNOW SHOWERS
GETTING TO THE POCONOS LATER AT NIGHT AS A MUCH COLDER AIRMASS TURNS
THE LAKE EFFECT MACHINE ON. WE ARE ANTICIPATING A BREEZE, WHICH MAY
INCREASE SOME AS THE CAA DEEPENS AND THE PRESSURE GRADIENT TIGHTENS.
FOR SATURDAY AND SUNDAY...A STRONG UPPER-LEVEL TROUGH SWINGS ACROSS
THE EAST SATURDAY BEFORE LIFTING NORTHEASTWARD SUNDAY. THIS FEATURE
WILL HAVE MUCH COLDER AIR WITH IT, WITH STRONG CAA OCCURRING
SATURDAY WHICH THEN WEAKENS SATURDAY NIGHT AND THEN TRANSITIONS TO
WAA THEREAFTER. THE 850 MB TEMPERATURES ARE FORECAST TO BE NEAR
-12C SATURDAY BEFORE MODERATING, THEREFORE A MUCH COLDER DAY IS
EXPECTED. THE COMBINATION OF CAA AND A TIGHT PRESSURE GRADIENT WITH
STRONG HIGH PRESSURE TO OUR SOUTHWEST WILL RESULT IN BREEZY TO WINDY
CONDITIONS SATURDAY. THE FORECAST SOUNDINGS SHOW ABOUT 35 KNOTS OF
WIND IN THE MIXING LAYER, AND ATTM WE BUMPED THE GUSTS UP TO 30
KNOTS AT THE SURFACE. THE COMBINATION OF TEMPERATURES IN THE 30S AND
40S AND GUSTY WINDS WILL BRING COLD WIND CHILLS INTO THE PICTURE.
WHILE THIS COLD SHOT IS NOT VERY SIGNIFICANT FOR THIS TIME OF YEAR,
IT WILL BE A SHOCK GIVEN HOW WARM IT HAS BEEN THIS MONTH. IT LOOKS
LIKE PHILADELPHIA /THE AIRPORT/ SHOULD FINALLY GET BELOW 32 DEGREES
SATURDAY NIGHT.
THE COLD WEST TO NORTHWEST FLOW IS EXPECTED TO RESULT IN LAKE EFFECT
SNOW AND SOME OF THIS ACTIVITY SHOULD GET PULLED INTO NORTHEASTERN
PENNSYLVANIA SATURDAY, ALLOWING FOR SOME SNOW SHOWERS INTO AT LEAST
THE POCONOS. THERE COULD EVEN BE SOME FLURRIES FARTHER SOUTH AND
EAST, HOWEVER THE SUB-CLOUD LAYER /DEW POINTS DROPPING THROUGH THE
TEENS SATURDAY/ MAY BE TO DRY WITH A SOUTHERN EXTENT AND THEREFORE
DID NOT CARRY A MENTION TO FAR SOUTH AND EAST. IT IS POSSIBLE THAT A
SNOW SQUALL GETS TO THE POCONOS GIVEN THE INVERSION HEIGHT RISING
SOME AND THE LOW-LEVEL LAPSE RATES STEEPENING. HIGH PRESSURE THEN
BRIEFLY ARRIVES SUNDAY WITH LESS WIND AS THE UPPER-LEVEL TROUGH
LIFTS OUT, HOWEVER WE SHOULD START TO HAVE A RETURN FLOW BECOME
ESTABLISHED DURING SUNDAY AS THE UPPER-LEVEL FLOW IS PROGRESSIVE.
THIS ALLOWS FOR WAA TO OCCUR AND THEREFORE A REBOUND IN AFTERNOON
TEMPERATURES /MIXING WILL BE LESS THOUGH/.
FOR MONDAY THROUGH WEDNESDAY...AN UPPER-LEVEL RIDGE ACROSS THE EAST
WILL ALLOW FOR MILDER AIR, HOWEVER A SHORT WAVE TROUGH MAY SLIDE
NEARBY LATER MONDAY AND TUESDAY. THIS SHOULD SEND A WEAKENING COLD
FRONT TOWARD OUR AREA, HOWEVER IT MAY NOT COMPLETELY MAKE IT.
OVERALL A MILDER PATTERN IS EXPECTED AND THIS COULD RESULT IN NEAR
RECORD WARMTH STARTING WEDNESDAY. THERE IS MORE UNCERTAINTY HOWEVER
AS AT LEAST SOME MODEL GUIDANCE SHOWS A MORE ACTIVE FRONT TUESDAY
AND WEDNESDAY WITH SOME RIPPLES OF LOW PRESSURE ALONG IT. IF THIS
WERE TO OCCUR AND THEREFORE NOT KEEPING OUR AREA MORE INTO A CLEAN
WARM SECTOR, COOLER TEMPERATURES WILL RESULT /OUR SUPERBLEND TOOL IS
COOLER FOR WEDNESDAY/. WE OPTED TO LEAN CLOSER TO THE WPC GUIDANCE
ATTM WHICH FAVORS SOME SLOWNESS OF THE MAIN FRONT AS THE UPPER-LEVEL
FLOW COULD BE MORE AMPLIFIED AND THE SOUTHEAST RIDGE SHOULD PLAY A
ROLE.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY, AND SURROUNDING AREAS.
TODAY...RAIN IS MOVING IN RAPIDLY FROM THE SW DURING THE MORNING.
VFR OR MVFR CIGS TO START WITH. CONDITIONS WILL DETERIORATE TO
IFR DURING MID DAY IN RAIN WITH POTENTIAL FOR BRIEF LIFR CONDS IN
ST/FOG NEAR THE PATH OF THE LOW DURING THE AFTERNOON WHICH WOULD
BE PHILLY AREA. WINDS WILL BE FROM THE E TO SE BUT SHOULD REMAIN
GENLY LESS THAN 10 KT EXCEPT POSSIBLY GUST 20 KT KACY MIDDAY. A
COLD FRONT WILL CROSS THE AREA LATE IN THE DAY WITH AN ASSOCD WIND
SHIFT TO THE SOUTHWEST OR WEST BUT LIGHT.
TONIGHT...PATCHY IFR/LIFR CONDS IN ST/FOG DURING THE EVENING,
ESPECIALLY KPHL SEWD. ANY LEFTOVER SHOWERS SHOULD END BY 02Z
VCNTY KACY. CONDITIONS IMPROVE TO VFR CIGS AOA 5000 FT LATE AT
NIGHT. WIND BECOMING NORTHWEST AND GRADUALLY INCREASES OVERNIGHT
WITH VSBY IMPROVING CONSIDERABLY AFTER 05Z/18.
OUTLOOK...
FRIDAY...OVERALL VFR AS SOME CLEARING TAKES PLACE FROM WEST TO EAST.
NORTHWESTERLY WINDS 10-15 KNOTS AND GUSTY AT TIMES.
SATURDAY...VFR. WEST-NORTHWEST WINDS 15-20 KNOTS WITH GUSTS TO 30
KNOTS, DIMINISHING AT NIGHT AND BECOMING WEST-SOUTHWEST.
SUNDAY AND MONDAY...VFR OVERALL, ALTHOUGH A FEW SHOWERS ARE
POSSIBLE LATE MONDAY. SOUTH-SOUTHWEST WINDS NEAR 10 KNOTS.
&&
.MARINE...
NO CHANGES ON THE MID-MORNING UPDATE.
FIRST PERIOD SCA FOR THE COASTAL WATERS FROM LITTLE EGG INLET NJ
(VCNTY KACY) SOUTHWARD TO DE. EXPECTING DURING THE MIDDAY-EARLY
AFTERNOON HOURS A BRIEF PERIOD OF SOUTHEAST INFLOW GUSTS 20-25 KT
AND SEAS INCREASING TO NEAR 5 FT ON THE ATLC WATERS. THIS IS
ISSUED WITH LESS THAN 80 PCT CONFIDENCE OF OCCURRENCE BUT ITS
BASICALLY OFFERED WITH SOME LEAD TIME. THE HRRR HAS SOME DECENT
INFLOW WIND AROUND 17Z-20Z. USUALLY HRRR WINDS ARE A BIT OVERDONE
BUT IN THIS CASE, SHAVED 5 FT AND STILL GET 25 KT GUSTS.
OTRW...CONDS SHOULD REMAIN SUB-SCA THROUGH TODAY NNJ WATERS AS
WELL AS DELAWARE BAY.
FOG MAY BECOME A MARINE TRANSPORTATION HAZARD LATE THIS AFTERNOON?
TONIGHT...NO SCA ANTICIPATED IN DEVELOPING NORTHWEST FLOW FOR THE
NNJ AND DE BAY WATERS BUT THE SCA MAY STILL BE NEEDED FOR THE ATLC
WATERS OF S NJ AND DE WHERE SEAS WILL BE AROUND 5 FT. DENSE FOG
MAY BE A MARINE TRANSPORTATION FACTOR THIS EVENING.
OUTLOOK...
FRIDAY THROUGH SATURDAY NIGHT...STRONG CAA AND A TIGHTENING PRESSURE
GRADIENT WILL ALLOW THE MIXING TO DEEPEN. THIS WILL RESULT IN GUSTS
TO 30 KNOTS MAINLY STARTING FRIDAY EVENING, HOWEVER A PERIOD OF
GALE FORCE GUSTS MAY OCCUR FRIDAY NIGHT AND SATURDAY. A SMALL
CRAFT ADVISORY IS LIKELY AND A GALE WATCH IS POSSIBLE. THE WINDS
DIMINISH SOME BY LATE SATURDAY NIGHT.
SUNDAY...NORTHWEST WINDS ARE EXPECTED TO WEAKEN AND SHIFT TO
SOUTHWESTERLY, HOWEVER CONDITIONS MAY BE CLOSE TO SMALL CRAFT
ADVISORY CRITERIA FOR A TIME.
MONDAY...A SOUTHWESTERLY FLOW SHOULD GUST TO ABOUT 25 KNOTS, HOWEVER
THE AIRMASS IS WARMING AND THIS COULD REDUCE THE OVERALL MIXING.
&&
.CLIMATE...
**DECEMBERS RECORD WARMTH MAY BE REINFORCED WITH MORE DAILY RECORDS
TOWARD CHRISTMAS**
WE ARE BEGINNING THE PROCESS OF POSTING RECORD MAXIMUM TEMPERATURES
THAT MAY BE APPROACHED OR EXCEEDED, AS OUR FORECAST NUMBERS AND OR
MODEL OUTPUT STATISTICAL GUIDANCE (SOMETIMES REFERRED TO AS MOS OR
STAT GUIDE) APPROACH OR EXCEED THE RECORDS.
IF YOU REMEMBER, TEMPERATURES PEAKED GENERALLY IN THE 60S ON DECEMBER
24-25 LAST YEAR AND AROUND DECEMBER 21-23 2013 (60S) AS WELL.
RECORD DAILY MAX TEMPERATURES BELOW
12/23
ACY 65-1990
PHL 66-1990
ILG 66-1990
ABE 64-1990
TTN 70-1891
GED 68-2013 AND 1949
RDG 63-2007 AND 1990
MPO 58-1990
TEMPERATURES HAVE BEEN SO WARM THE FIRST 16 DAYS OF THE MONTH (9
TO 13 DEGREES ABOVE NORMAL) THAT IT WILL TAKE QUITE A SUBSTANTIAL
COLD SPELL TO PREVENT A RECORD WARM DECEMBER, AND THIS AFTER A TOP
8 WARMEST NOVEMBER ON RECORD. HOWEVER, WE SUGGEST NOT EXTRAPOLATING
THIS WARMTH FOR THE REST OF OUR WINTER.
GEFS AND EC ENSEMBLES ARE CONTINUING AN TO WARM US TO RECORD WARM
DAILY VALUES AGAIN TOWARD CHRISTMAS.
THEREAFTER, THE 00Z/17 GEFS CONTINUES A NOTABLE EAST COAST RIDGE!
FAST WESTERLY FLOW ACROSS THE NORTH ATLANTIC AND NO SIGN OF SUBSTANTIAL
RIDGING IN WESTERN NORTH AMERICA OR ANY DEPRESSED JET ACROSS THE
SOUTHERN USA ALL SUGGEST THAT BELOW NORMAL COLD IS NOT LIKELY HERE FOR
MORE THAN A DAY OR 2 (IF THAT), BETWEEN NOW AND THE NEW YEAR.
UNTIL SOMETHING WITHIN THAT OVERALL PATTERN CHANGES SUBSTANTIALLY,
WE WILL CONTINUE TO HOPEFULLY ENJOY GENERALLY ABNORMALLY MILD
WEATHER. THE LACK OF SNOW COVER ALSO CONTRIBUTES TO THE POSITIVE
DAILY DEPARTURE FROM CLIMATOLOGY.
PROJECTIONS EVALUATED WITH THIS MORNINGS 330 AM THURSDAY DECEMBER
17 FORECAST ARE EASILY 8 TO 11 DEGREES ABOVE NORMAL FOR THE
ENTIRE MONTH.
DECEMBER PROJECTED BELOW
ABE NORMAL DECEMBER AVERAGE TEMPERATURE IS 32.3. WE ARE EXPECTING AROUND
43.0. THAT WOULD BE THE WARMEST SINCE RECORDS BEGAN IN 1922, AND 3
DEGREES WARMER THAN THE PREVIOUS WARMEST, DECEMBER 1923, WHEN THE
AVERAGE WAS 40.0
PHL NORMAL DECEMBER AVERAGE TEMPERATURE IS 37.5. WE ARE EXPECTING
AROUND 47.0. THAT WOULD BE THE WARMEST SINCE TEMPERATURE RECORDS
BEGAN IN 1874 (PRECIP RECORDS BEGAN THERE IN 1872). AND THIS WOULD
BE ALMOST 3 DEGREES WARMER THAN THE PREVIOUS WARMEST DECEMBER
1923, WHEN THE AVERAGE WAS 44.5 DEGREES.
THESE VALUES WERE CALCULATED USING OUR PHI 09Z/17 FORECAST
THROUGH D7, THEN ADDING ON THE D8-11 TEMPS FROM THE 00Z/17
NMCFTPRHA (GFS 2M MAX/MIN TEMPS) AND FINALLY, FOR THE LAST 4 DAYS
OF THE MONTH, WE JUST USED STRAIGHT DAILY NORMALS FOR EACH
LOCATION.
THE NUMBERS ABOVE WILL VARY FROM CURRENTLY PROJECTED... AND WE COULD
SEE CHANGES OF 2 DEGREES EITHER WAY, BUT OVERALL WHEN ALL THE DAILIES
ARE AVERAGED... WE WILL PROBABLY EXPERIENCE OUR WARMEST DECEMBER ON
RECORD, THROUGH 2015. THE VALUES POSTED HERE MAY BE CONSERVATIVELY
TOO COOL.
PHL HAS NOT BEEN BELOW NORMAL SINCE NOV 24TH.
PHILADELPHIA`S FIRST SUBFREEZING TEMPERATURE OF THE COOL SEASON SHOULD
OCCUR SUNDAY MORNING...THE LAST DAY OF FALL (DEC 20), EASILY EXCEEDING
THE PREVIOUS LATEST SUBFREEZING DATE OF DECEMBER 12 1998. OFFICIAL
TEMPERATURE RECORDS FOR PHILADELPHIA DATE BACK TO 1874.
PORTIONS OF ALL OF THIS CLIMATE SECTION OF THE AFD WILL BE DISCONTINUED
LATER TODAY BUT WILL BE UPDATED AGAIN FRIDAY MORNING AND THEN AGAIN
ON CHRISTMAS DAY.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
ANZ452>455.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...DRAG/GAINES/SZATKOWSKI
SHORT TERM...DRAG
LONG TERM...GORSE
AVIATION...DRAG/GORSE/SZATKOWSKI
MARINE...DRAG/GORSE/SZATKOWSKI
CLIMATE...
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1158 AM CST THU DEC 17 2015
.UPDATE...
ISSUED AT 1045 AM CST THU DEC 17 2015
Updating the forecast for stronger winds today and also low clouds
have spread quicker into southeast IL this morning, now MVFR
ceilings 2200-2600 feet covering central and southeast IL. NW
winds of 8-18 mph and gusts of 18-25 mph into early afternoon to
gradually diminish to 7-12 mph by 5 pm.
Strong 515 dm 500 mb low near the southern Manitoba and Ontario
province line was embedded in deep upper level trof over the Great
Plains which will track east into the MS river valley by 12Z/6 am
Friday. HRRR shows overcast MVFR clouds to continue across central
and southeast IL rest of today with some breaks developing in
western CWA during the evening. As surface 1031 mb Canadian high
pressure over the high plains and central Rockies to settled
southward toward southern plains through Friday morning keeping IL
in a seasonably cool nw wind flow. Though winds will be lighter by
sunset. Temperatures at 10 am were in the low to mid 30s and will
not rise too much today with low overcast clouds and nw winds. Highs
today in the mid to upper 30s over central IL with areas southeast
of I-70 near 40F, which is close to normal for mid Dec.
&&
.SHORT TERM...(Today)
ISSUED AT 316 AM CST THU DEC 17 2015
Cold front has passed well east of Illinois early this morning:
however, a large area of low clouds behind the boundary is
currently filtering into the area from the northwest. 09z/3am IR
satellite imagery shows the leading edge of the clouds along a
Champaign to Taylorville line...with overcast conditions upstream
across Iowa into the eastern Dakotas. HRRR has been handling the
clouds relatively well throughout the evening and shows them
spreading across the entire KILX CWA by 14/15z. Once the clouds
arrive, they will be very slow to depart...as NAM forecast
soundings indicate a persistent moist layer at around 925mb
through Friday morning. Thanks to cloudy skies and a chilly
northwesterly breeze of 10 to 15mph, high temperatures will be
near normal for this time of year. Have undercut MAV guidance
numbers by a couple of degrees, with readings mainly in the middle
to upper 30s.
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 316 AM CST THU DEC 17 2015
As mentioned in the short-term discussion, forecast soundings
suggest clouds will stick around through tonight before slowly
clearing from southwest to northeast across the area on Friday.
Short-wave trough evident on latest water vapor imagery over western
Wyoming will track southeastward into the Southern Plains this
evening then into the Tennessee River Vally by Friday morning. This
feature will remain well to the S/SW of Illinois and will not play a
factor in the weather across the KILX CWA. As a result, am
expecting a cold/dry day on Friday with highs once again remaining
in the 30s. As surface high pressure approaches from the west,
clearing skies and diminishing winds will allow low temperatures
Saturday morning to bottom out in the teens and lower 20s.
Once high pressure shifts east of the region, southerly return flow
will lead to a warming trend by Sunday. Gusty southwesterly
winds ahead of the next approaching cold front will boost high
temperatures into the upper 40s and lower 50s. 00z Dec 17 models
are in excellent agreement concerning the frontal boundary
expected to pass through central Illinois early Monday. Thanks
to a strong flow northward from the Gulf of Mexico, it appears
the front will have enough moisture to work with to trigger
scattered showers Sunday night into Monday morning. Front will
then quickly exit into Indiana, leading to a period of dry
weather Monday afternoon/night.
After that, model solutions diverge next week as W/SW upper flow
allows a series of systems to impact the region. Timing and
strength of these features remain in question, with the GFS showing
dry conditions Tuesday followed by a period of rain Wednesday into
early Thursday...while the ECMWF shows rain on Tuesday and again on
Wednesday. With such significant model spread still present, opted
to make only minor changes to the extended forecast beyond Monday.
Will keep PoPs in the slight chance category through much of the
period...but will highlight Tuesday night through Wednesday night as
the most likely period for rain with 40-50 PoPs. Regardless of
which model verifies, the main story next week will be the warmer
temperatures. All solutions show ridging across the eastern CONUS
and unseasonably warm 850mb temps, which will lead to highs well
into the 40s and 50s Monday through Wednesday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1155 AM CST THU DEC 17 2015
MVFR ceilings of 2-3k ft will continue with stratocumulus cloud
deck across the central IL airports into this evening, though
some breaks to appear nw by PIA later today. Have low clouds
scattering out at times from nw to se between 04Z-08Z, but some
broken mid level clouds 10-12k ft to pass through later this
evening and overnight. Another batch of stratocumulus clouds from
2.5-4k ft to skirt areas from I-74 north late tonight and Fri
morning and be more scattered further south at SPI and DEC. WNW
winds 10-15 kts with gusts near 20 kts into mid afternoon to
diminish to 6-10 kts this evening and veer more westerly. West
winds increase to 12-16 kts with gusts of 17-22 kts Friday
morning. Strong upper level trof over the Great Plains to shift
eastward to near the IL/IN border by 18Z/noon Friday. At the
surface 1031 mb Canadian high pressure over the central Rockies
and high plains to ridge into the southern Plains Friday morning
keeping IL in a westerly flow.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...07
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...07
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1045 AM CST THU DEC 17 2015
.UPDATE...
ISSUED AT 1045 AM CST THU DEC 17 2015
Updating the forecast for stronger winds today and also low clouds
have spread quicker into southeast IL this morning, now MVFR
ceilings 2200-2600 feet covering central and southeast IL. NW
winds of 8-18 mph and gusts of 18-25 mph into early afternoon to
gradually diminish to 7-12 mph by 5 pm.
Strong 515 dm 500 mb low near the southern Manitoba and Ontario
province line was embedded in deep upper level trof over the Great
Plains which will track east into the MS river valley by 12Z/6 am
Friday. HRRR shows overcast MVFR clouds to continue across central
and southeast IL rest of today with some breaks developing in
western CWA during the evening. As surface 1031 mb Canadian high
pressure over the high plains and central Rockies to settled
southward toward southern plains through Friday morning keeping IL
in a seasonably cool nw wind flow. Though winds will be lighter by
sunset. Highs today in the mid to upper 30s with areas southeast
of I-70 near 40F which is close to normal for mid Dec.
&&
.SHORT TERM...(Today)
ISSUED AT 316 AM CST THU DEC 17 2015
Cold front has passed well east of Illinois early this morning:
however, a large area of low clouds behind the boundary is
currently filtering into the area from the northwest. 09z/3am IR
satellite imagery shows the leading edge of the clouds along a
Champaign to Taylorville line...with overcast conditions upstream
across Iowa into the eastern Dakotas. HRRR has been handling the
clouds relatively well throughout the evening and shows them
spreading across the entire KILX CWA by 14/15z. Once the clouds
arrive, they will be very slow to depart...as NAM forecast
soundings indicate a persistent moist layer at around 925mb
through Friday morning. Thanks to cloudy skies and a chilly
northwesterly breeze of 10 to 15mph, high temperatures will be
near normal for this time of year. Have undercut MAV guidance
numbers by a couple of degrees, with readings mainly in the middle
to upper 30s.
.LONG TERM...(Tonight through Wednesday)
ISSUED AT 316 AM CST THU DEC 17 2015
As mentioned in the short-term discussion, forecast soundings
suggest clouds will stick around through tonight before slowly
clearing from southwest to northeast across the area on Friday.
Short-wave trough evident on latest water vapor imagery over western
Wyoming will track southeastward into the Southern Plains this
evening then into the Tennessee River Vally by Friday morning. This
feature will remain well to the S/SW of Illinois and will not play a
factor in the weather across the KILX CWA. As a result, am
expecting a cold/dry day on Friday with highs once again remaining
in the 30s. As surface high pressure approaches from the west,
clearing skies and diminishing winds will allow low temperatures
Saturday morning to bottom out in the teens and lower 20s.
Once high pressure shifts east of the region, southerly return flow
will lead to a warming trend by Sunday. Gusty southwesterly
winds ahead of the next approaching cold front will boost high
temperatures into the upper 40s and lower 50s. 00z Dec 17 models
are in excellent agreement concerning the frontal boundary
expected to pass through central Illinois early Monday. Thanks
to a strong flow northward from the Gulf of Mexico, it appears
the front will have enough moisture to work with to trigger
scattered showers Sunday night into Monday morning. Front will
then quickly exit into Indiana, leading to a period of dry
weather Monday afternoon/night.
After that, model solutions diverge next week as W/SW upper flow
allows a series of systems to impact the region. Timing and
strength of these features remain in question, with the GFS showing
dry conditions Tuesday followed by a period of rain Wednesday into
early Thursday...while the ECMWF shows rain on Tuesday and again on
Wednesday. With such significant model spread still present, opted
to make only minor changes to the extended forecast beyond Monday.
Will keep PoPs in the slight chance category through much of the
period...but will highlight Tuesday night through Wednesday night as
the most likely period for rain with 40-50 PoPs. Regardless of
which model verifies, the main story next week will be the warmer
temperatures. All solutions show ridging across the eastern CONUS
and unseasonably warm 850mb temps, which will lead to highs well
into the 40s and 50s Monday through Wednesday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 536 AM CST THU DEC 17 2015
MVFR CIGS will prevail across the central Illinois terminals
through the bulk of the 12Z TAF valid time. Low level moisture
trapped beneath an inversion will be slow to clear, although some
clearing is possible by late tonight. Westerly winds will prevail
through the period as well, and will initially be a little gusty
this morning.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...07
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1136 AM CST THU DEC 17 2015
.SHORT TERM /TODAY/...
ISSUED AT 315 AM CST THU DEC 17 2015
CLOUDS EXPECTED TO HOLD ON THROUGH AREA GOOD SHARE OF THE
DAY...THOUGH DRIER AIR ATTEMPTING TO PUNCH INTO WESTERN PORTION OF
THE FORECAST AREA BETWEEN 16Z AND 21Z THIS AFTERNOON. HRRR AND RAP13
BOTH HINT AT CLEARING AREA IN WESTERN DAKOTAS NOW WILL REACH THE
WEST BY LATE MORNING. COMPLICATING MATTERS...IS ANOTHER WEAK SHORT
WAVE BEHIND THE MAIN UPPER LOW. THIS WILL REACH THE NORTHERN
COUNTIES BETWEEN 21 AND 00Z THIS AFTERNOON. NAM SHOWS SLIGHTLY
BETTER MOISTURE WITH THE FEATURE AND A HINT AT SOME MINOR
INSTABILITY BY THEN AS WELL. UPSTREAM NOW...SCATTERED LIGHT FLURRIES
AND SOME BLOWING SNOW REPORTED. WILL ADD FLURRIES FAR NORTHWEST
BETWEEN 21 AND 00Z AS THE WEAK WAVE APPROACHES.
OTHERWISE ...TEMPERATURES WILL BE MORE SEASONAL WITH HIGHS IN THE
UPPER 20S NORTH TO MID 30S IN THE SOUTH. NORTHWEST WINDS WILL
INCREASE AGAIN THIS AFTERNOON AS MIXING BEGINS. BETTER WINDS AND
GUSTS ACROSS THE NORTH WITH AMBIENT FLOW OF AROUND 20 MPH AND
GUSTS TO NEARER 30 MPH AT TIMES TODAY.
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 315 AM CST THU DEC 17 2015
MAIN FORECAST CONCERN WAS FOCUSED ON SNOW SQUALL POTENTIAL AND
GUSTY WINDS FRIDAY OVER NORTHERN IOWA AND TEMPERATURES THROUGH
THE WEEKEND AND INTO NEXT WEEK. MODELS ARE COMING INTO SLIGHTLY
BETTER AGREEMENT WITH SYSTEM SUNDAY NIGHT INTO MONDAY AND UTILIZED
A GFS20/ECMWF BLEND SUNDAY INTO NEXT WEEK. TONIGHT INTO
SATURDAY...USED A NAM12/SREF/GFS20 BLEND.
TONIGHT INTO FRIDAY...UPPER LEVEL TROUGH WILL CONTINUE TO MOVE
ACROSS THE REGION TONIGHT INTO FRIDAY...WITH A SECONDARY PUSH OF CAA
ANTICIPATED VIA A FAIRLY STRONG PV ANOMALY IS EXPECTED LATE FRIDAY
MORNING. CONCERNED FOR POTENTIAL FOR SNOW SQUALLS OVER NORTHERN
IOWA LATE FRIDAY MORNING INTO THE AFTERNOON. NAM/GFS BUFR
SOUNDINGS SATURATE THE DENDRITIC LAYER B/T 15-21Z AND WINDS ATOP
THE MIXED LAYER RANGE AROUND 30-35 KNOTS. DECENT FORCING
ASSOCIATED WITH THE PV ANOMALY ALONG WITH SOME WEAK ELEVATED
INSTABILITY PRESENT TOWARDS THE AFTERNOON HOURS OVER NORTHERN
IOWA. ALBEIT THE NAM12 IS LIKELY OVERDOING THE INSTABILITY.
HOWEVER...THERE WAS ENOUGH OF A SIGNAL TO AT LEAST INCREASE
WORDING TO PERIODS OF SNOW SHOWERS ON FRIDAY. LOW CONFIDENCE IN
ANY SNOW ACCUMULATION AND THUS LEFT OUT POPS. CERTAINLY COULD HAVE
GONE WITH THE CATEGORICAL POPS/LOW QPF SCENARIO AND SOMETHING TO
CONSIDER NEXT FORECAST PACKAGE IF MODELS CONTINUE WITH THIS
SIGNAL. SOUNDINGS QUICKLY LOSE THEIR MOISTURE PAST 21Z FRIDAY AND
ONLY HAVE FLURRIES MENTIONED AFTER THIS TIME FRAME.
FRIDAY NIGHT INTO SUNDAY...SURFACE HIGH PRESSURE BUILDS INTO THE
STATE AND CENTERS ITSELF OVER THE FORECAST AREA BY SATURDAY MORNING.
THIS WILL PROVIDE GOOD RADIATION COOLING AND LOWERED TEMPERATURES
2 TO 4 DEGREES ACROSS THE FORECAST AREA. THINKING THE GFS IS TOO
COLD...BUT ECMWF/NAM WERE IN GOOD AGREEMENT FOR LOWS SATURDAY
MORNING.
TEMPERATURES LOOK TO QUICKLY REBOUND ON SATURDAY AS WAA DEVELOPS
LATE SATURDAY MORNING AS THE SURFACE MOVES EAST. THE WAA PERSISTS
INTO SUNDAY AND HAVE A NON-DIURNAL TEMPERATURE TREND GOING
SATURDAY NIGHT INTO SUNDAY. THIS RESULTED IN INCREASING MINIMUM
TEMPERATURES SATURDAY NIGHT AND MAXIMUM TEMPERATURES ON SUNDAY.
SURFACE LOW PRESSURE EJECTS OUT OF THE CENTRAL ROCKIES WITH A
POTENT 500MB VORT MAX TRAILING BEHIND IT ON SUNDAY. THE PHASING
BETWEEN THE TWO COME TOGETHER EAST OF THE FORECAST AREA BY SUNDAY
NIGHT AS THE LOW DEEPENS OVER THE GREAT LAKES REGION. THUS...THE
BEST FORCING TRAILS BEHIND THE DEEPEST MOISTURE IN EASTERN IOWA
AND HAVE LOW POPS GOING SUNDAY INTO SUNDAY NIGHT.
MONDAY INTO WEDNESDAY...MONDAY WILL BE COOLER AS CAA CONTINUES
THROUGH MUCH OF THE DAY BEFORE WEAKENING BY THE LATE AFTERNOON.
AFTER A QUIET DAY TUESDAY...STRONG WAA AND THETA-E ADVECTION
DEVELOP ON WEDNESDAY AHEAD OF A DEEPENING LOW PRESSURE SYSTEM OVER
THE DAKOTAS. HOWEVER...GFS/ECMWF REMAIN IN DISAGREEMENT TIMING AND
LOCATION AS ECMWF IS FURTHER NORTH AND SLIGHTLY FASTER IN THE
PROGRESSION. POTENTIAL FOR SOME LIGHT PRECIP OVER EASTERN AND
NORTHERN PORTIONS OF THE FORECAST AREA WEDNESDAY INTO THURSDAY.
&&
.AVIATION...17/18Z
ISSUED AT 1136 AM CST THU DEC 17 2015
CLEARING OCCURRING FROM WEST TO EAST AS HIGH PRESSURE NOSES INTO IA.
A WEAK WAVE WILL BRING MVFR CIGS BRIEFLY BACK ACROSS THE NORTH WITH
SOME FLURRIES POSSIBLE 21Z THROUGH 02Z. IT WILL ALSO BE BREEZY
ACROSS TAF LOCATIONS TODAY INTO TONIGHT. A STRONGER WAVE WILL
IMPACT THE NORTHERN TAF LOCATIONS AFT 08Z BRINGING LOWER CIGS BACK
AFT 11Z WITH SNOW SHOWERS POSSIBLE FOR KMCW AND KALO.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...PODRAZIK
AVIATION...FAB
AREA FORECAST DISCUSSION
NWS GOODLAND KS
212 PM MST THU DEC 17 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 209 PM MST THU DEC 17 2015
THE SHORTWAVE TROUGH THAT HAS BEEN MOVING OVER THE CWA TODAY WILL BE
SOUTHEAST OF THE REGION BY 00Z TONIGHT...THIS ALONG WITH DRY
AIR BEING ADVECTED INTO THE REGION WILL END THE LIGHT SNOWFALL AND
FLURRIES OVER THE AREA. SATELLITE VISIBILITY SHOWS CLOUD COVER OVER
THE REGION IN ASSOCIATION WITH THE SHORTWAVE AND SNOWFALL BUT WILL
START TO CLEAR OUT FROM THE NORTHWEST TO SOUTHEAST AROUND 22Z
THURSDAY. SKIES WILL BE MOSTLY CLEAR WITH LIGHT WINDS OVERNIGHT
...THIS WILL DROP THE TEMPERATURES TO NEARLY ZERO DEGREES F UP TO
THE MID TEENS.
THE CURRENT MODEL RUNS AND FORECAST HAVE NO FOG EXPECTED TO DEVELOP
OVER THE CWA...BUT THE SREF HAS SOME REDUCED VISIBILITIES OF LESS
THAN 3 MILES FRIDAY MORNING IN SOUTHWEST KANSAS...THE HRRR ALSO
SHOWS SOMETHING DEVELOPING OVER THE SAME AREA...BUT CONFIDENCE IS
LOW THAT FOG WILL MAKE IT UP INTO OUR AREA DUE TO THE 10 KTS
SOUTHWEST WINDS. WILL HAVE TO KEEP AN EYE OUT ON THIS...IF THERE IS
ANY FOG TO DEVELOP IT WILL BE IN THE SOUTHERN CWA COUNTIES.
A RIDGE WILL START TO PUSH INTO THE CWA THURSDAY EVENING INTO
FRIDAY...BRING WITH IT DRY CONDITONS AND WINDS FROM THE
SOUTHWEST...THIS WILL FAVOR MUCH WARMER TEMPERATURES IN THE MID 40S
TO LOW 50S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 209 PM MST THU DEC 17 2015
A RIDGE WILL MOVE INTO THE PLAINS FRIDAY NIGHT AND SATURDAY. THE
RIDGE WILL SHIFT EAST SATURDAY NIGHT AHEAD OF A TROUGH THAT IS
PROGGED TO SHIFT EAST INTO CENTRAL COLORADO SUNDAY. SURFACE HIGH
PRESSURE WILL CONTINUE OVER THE PLAINS FRIDAY NIGHT. A TROUGH WILL
MOVE INTO EASTERN COLORADO SATURDAY AND THEN SHIFT EAST INTO
NORTHWEST KANSAS SUNDAY.
SUBSIDENCE WILL CONTINUE THROUGH SATURDAY. LACK OF SUFFICIENT
MOISTURE WILL PERSIST THROUGH SATURDAY NIGHT AND SUNDAY AS DYNAMICS
FROM A SHORTWAVE TROUGH START TO MOVE INTO THE AREA. AS A RESULT,
DRY CONDITIONS SHOULD CONTINUE THROUGH SUNDAY. POPS WILL BE NIL FOR
THESE PERIODS.
MIN TEMPERATURES SHOULD COOL TO THE LOWER 20S FRIDAY NIGHT AND THEN
MODERATE TO THE MID AND UPPER 20S SATURDAY NIGHT. MAX TEMPERATURES
FRIDAY SHOULD REACH THE MID 50S BUT COOLER READINGS ARE EXPECTED
SUNDAY IN THE MID TO UPPER 40S.
IN THE EXTENDED...(SUNDAY NIGHT THROUGH THURSDAY)...
UPPER FLOW WILL BE NORTHWEST SUNDAY NIGHT AND THEN BECOME ZONAL
MONDAY. A TROUGH WILL MOVE THROUGH THE PLAINS TUESDAY AND
WEDNESDAY. NORTHWEST FLOW WILL RESUME THURSDAY BEHIND THE EXITING
TROUGH. SURFACE HIGH PRESSURE WILL MOVE INTO THE AREA SUNDAY NIGHT
AND THEN SHIFT EAST MONDAY AS A TROUGH MOVES INTO EASTERN COLORADO.
THE TROUGH WILL REMAIN OVER THE AREA THROUGH TUESDAY AND THEN SHIFT
SOUTH WEDNESDAY AHEAD OF A COLD FRONT MOVING INTO THE AREA. HIGH
PRESSURE WILL BUILD INTO NORTHWEST KANSAS THURSDAY BEHIND THE
EXITING TROUGH.
THE EXTENDED FORECAST WILL REMAIN DRY DUE TO SUSSIDENCE SUNDAY NIGHT
AND MONDAY. MODEL DIFFERENCES DUE TO TIMING AND/OR AVAILABLE
MOISTURE FOR TUESDAY THROUGH THURSDAY RESULT IN A DRY FORECAST FOR
THOSE PERIODS AS WELL.
MIN TEMPERATURES ARE EXPECTED IN THE LOWER TO MIDDLE 20S WITH SOME
UPPER 20S POSSIBLE IN THE FAR EAST TUESDAY NIGHT. MAX TEMPERATURES
SHOULD REACH THE MID AND UPPER 40S MOST DAYS WITH THE EXCEPTIONS OF
MONDAY AND THURSDAY WHEN SLIGHTLY COOLER TEMPERATURES ARE EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1037 AM MST THU DEC 17 2015
KGLD...A SHORTWAVE TROUGH IS MOVING OVER THE REGION AND WILL BE
THROUGH THE AREA BY 00Z FRIDAY. RADAR IS INDICATING LIGHT
SNOWFALL MOVING THROUGH THE REGION FROM NORTHWEST TO SOUTHEAST.
THERE WILL BE A PERIOD OF IFR CONDITIONS THROUGH MID AFTERNOON
DURING THE SNOWFALL. VFR CONDITIONS WILL PREVAIL ONCE THIS
DISTURBANCE PASSES THIS EVENING.
KMCK...AREAS OF SNOWFALL ARE EXPECTED TO STAY SOUTH OF THE
TERMINAL...BUT CAN NOT RULE OUT A BRIEF SNOW SHOWER THIS
AFTERNOON. OVERALL VFR CONDITIONS ARE EXPECTED TO PREVAIL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLT
LONG TERM...FS
AVIATION...CLT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1104 AM MST THU DEC 17 2015
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 205 AM MST THU DEC 17 2015
EARLY MORNING WV IMAGERY SLOWS SHORTWAVE TROUGH OVER
WYOMING/NORTH CENTRAL COLORADO MOVING TO THE SOUTHEAST. RAP UPPER
LEVEL ANALYSIS SHOWS STRONG H3 JET (100-120KT) UPSTREAM OF THIS
FEATURE MOVING INTO WESTERN WYOMING. LARGE SCALE PATTERN IS
DOMINATED BY AMPLIFYING RIDGE ALONG WESTERN US COAST AND LONGWAVE
TROUGH ACROSS THE CENTRAL US. LIGHT SNOW IS ALREADY BEING REPORTED
AT AKRON COLORADO UPSTREAM FROM OUR CWA.
TODAY-TONIGHT...UPPER LEVEL SHORTWAVE TROUGH IS SHOWN TO SPLIT
AROUND OUR CWA WITH STRONGEST FORCING STARTING TO OUR
WEST/NORTHWEST AND THEN TRENDING TO THE SOUTHEAST WITH MEAN FLOW
THROUGH THIS AFTERNOON AND EVENING. BEST FORCING APPEARS TO BE
MIDDAY THROUGH THE AFTERNOON...THOUGH NOSE OF UPPER LEVEL JET WILL
ACTUALLY BE PASSING THROUGH THE REGION THIS EVENING. GFS INITIATED
WITH A LITTLE MORE MOISTURE THAN 00Z SOUNDINGS WOULD HAVE
INDICATED AND NAM/RAP MOISTURE PROFILES WERE FAVORED. THIS WILL BE
CRITICAL AS MOISTURE APPEARS TO BE THE LIMITING FACTOR OF
DURATION/EXTENT OF SNOWFALL TODAY. RAP/NAM SUPPORT SATURATION
AROUND OR AFTER 18Z IN THE CENTRAL PART OF OUR FORECAST
AREA...WITH A 3HR PERIOD OF LIGHT QPF TRANSLATING ACROSS THE
AREA. WITH UPSTREAM OBS ALREADY SHOWING LIGHT SNOW I SHOWED A
SLIGHTLY FASTER TREND IN THE NORTHWEST. I THEN USED 925-700 MB
LAYER QG FRONTOGENESIS AND RH A GOOD PROXY FOR TRACK OF THIS AREA
OF SNOWFALL.
THE AIR MASS ALREADY IN PLACE IS COLD ENOUGH THAT WHEN SATURATED WE
SHOULD SEE ALL SNOW...AND WITH CAA THROUGH THE AFTERNOON HIGHER
RATIOS SHOULD BE SUPPORTED. VERY DRY AIR ADVECTS BACK INTO THE
REGION BEHIND THIS FAST MOVING SHORTWAVE SO BY EARLY THIS EVENING
PRECIP SHOULD BE WINDING DOWN FROM THE NORTHWEST TO THE SOUTHEAST.
BASED ON LATEST CONSENSUS QPF AND SNOW-LIQUID RATIOS IN THE 15-18
RANGE WE SHOULD SEE ACCUMULATIONS IN THE 0.5-1.5" RANGE...BEST
CHANCES ALONG A WRAY TO RUSSEL SPRINGS LINE. WHILE BRIEF
VISIBILITY REDUCTIONS ARE POSSIBLE...THEY SHOULDN`T BE WIDESPREAD
OR PERSISTENT CONSIDERING LIMITED WINDS DURING THE EVENT (WINDS DO
INCREASE SOME BEHIND SHORTWAVE). I PLAN ON KEEPING MENTION
LIMITED TO HWO.
FRIDAY-SATURDAY NIGHT...UPPER LEVEL RIDGING BUILDS ACROSS THE
CENTRAL ROCKIES/PLAINS FRIDAY AND SHIFTS EAST WITH SW FLOW
DEVELOPING SATURDAY. THIS WILL SUPPORT DRY CONDITIONS THROUGH THESE
PERIODS WITH WARMER TEMPERATURES. DEPENDING ON ANY SNOW PACK FRIDAY
WARM UP MAY BE TEMPERED SLIGHTLY...THOUGH POTENTIAL FOR HIGHS IN THE
LOWER 50S EXISTS. SATURDAY SHOULD BE MILD WITH STRONGER LEE TROUGH
DEVELOPMENT AND SW FLOW SUPPORTING STRONGER WAA. STATISTICAL
GUIDANCE HAS TRENDED TOWARDS LOW TO MID 50S...AND THIS SEEMS
REASONABLE CONSIDERING TEMPS ALOFT AND PATTERN.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 144 AM MST THU DEC 17 2015
FORECAST PROBLEM...ALBEIT A MINOR ONE...IS A LOW CHANCE OF
PRECIPITATION TOWARD THE END OF THIS PERIOD. SATELLITE CURRENTLY
SHOWING AN AMPLIFIED PATTERN FROM THE CENTRAL PACIFIC INTO THE
CENTRAL ATLANTIC.
IN GENERAL THE PATTERN THIS PERIOD WILL BE PROGRESSIVE AND NEARLY
ZONAL AT TIMES. A NUMBER OF FAST MOVING OPEN TROUGHS MOVE THROUGH
DURING THIS TIME. THE FIRST ONE IS ON SUNDAY. THE ECMWF/GFS SPIT OUT
A FEW HUNDREDTHS OF QPF. HOWEVER LOOKING AT THE SOUNDINGS THERE IS A
VERY DEEP DRY LAYER IN PLACE. SO LEFT ALONE THE DRY FORECAST THE
INIT GAVE ME.
A TROUGH COMES ACROSS ON WEDNESDAY AND THE INIT GAVE ME SOME SLIGHT
CHANCE POPS IN THE WEST AND THAT LOOKS REASONABLE. OVERALL MADE NO
CHANGES TO WHAT THE INIT GAVE ME. HOWEVER GIVEN THE FAST WESTERLY
PATTERN WOULD NOT BE SURPRISED IF HIGH TEMPERATURES END UP BEING
A LITTLE WARMER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1037 AM MST THU DEC 17 2015
KGLD...A SHORTWAVE TROUGH IS MOVING OVER THE REGION AND WILL BE
THROUGH THE AREA BY 00Z FRIDAY. RADAR IS INDICATING LIGHT
SNOWFALL MOVING THROUGH THE REGION FROM NORTHWEST TO SOUTHEAST.
THERE WILL BE A PERIOD OF IFR CONDITIONS THROUGH MID AFTERNOON
DURING THE SNOWFALL. VFR CONDITIONS WILL PREVAIL ONCE THIS
DISTURBANCE PASSES THIS EVENING.
KMCK...AREAS OF SNOWFALL ARE EXPECTED TO STAY SOUTH OF THE
TERMINAL...BUT CAN NOT RULE OUT A BRIEF SNOW SHOWER THIS
AFTERNOON. OVERALL VFR CONDITIONS ARE EXPECTED TO PREVAIL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...CLT
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
1139 AM CST THU DEC 17 2015
...Updated Aviation Section...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 123 AM CST THU DEC 17 2015
An upper level disturbance will approach the region from the northwest
this morning and move across the state through today. This will lead
to some snow showers across the region. Moisture is mainly rooted in
the 850-600-hPa layer, so a significant precip maker is not expected.
Increased pops to high chance category given decent agreement between
global and mesoscale models. Largely followed the ARW for pop arrangement
with a slight bias towards the ECMWF as well. Have 1" snow accumulations
within a polygon from Syracuse to Dodge City to Dighton. This is mostly
in agreement with WPC. The ARW and HRRR show amounts over 2". Will not
issue a winter weather advisory since grid values are below criteria.
Not expecting a major impact as well in terms of hazardous travel conditions.
Also have undercut highs for today as plenty of cloud cover is expected.
Lows heading into Friday morning will be mainly in the teens as high
pressure builds in and the sky clears.
.LONG TERM...(Friday THROUGH Wednesday)
ISSUED AT 123 AM CST THU DEC 17 2015
A dry forecast is expected through the rest of the forecast domain.
There is still some chatter about a significant storm system by the
end of December. This is not an official NWS forecast and was only based
on one model solution (a poor performing model at that). FWIW, that
snow storm is not even shown anymore for SW Kansas on said model. Anyway,
pops will remain aob 14 percent. No significant precipitation is expected
to close out the extended. A frontal system will move through Sunday,
however, wind is mainly associated with this system. Any precip should
remain in eastern Kansas. Beyond this, a zonal flow pattern sets up.
This will favor near to above normal temperatures. Another dry system
might move across towards the holiday. Ahead of this system, might
end up fairly warm for xmas.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Friday AFTERNOON)
ISSUED AT 1136 AM CST THU DEC 17 2015
The first little wave of snow was moving away from the southwest
KS terminals (DDC, GCK), but ceiling will most likely remain in
the MVFR category anywhere from 1000 to 2500 feet. Some remaining
very light snow or flurries will temporarily reduce visibility to
4 to 6 miles and ceiling around 800 or 900 feet. This afternoon,
another small round of snow showers will move southeast, but the
track of this small batch will likely only affect GCK terminal
this afternoon with a couple hours of potential IFR in light snow.
The light snow event will pull away this evening with VFR resuming
and winds remaining at or below 10 knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 31 15 41 25 / 50 30 0 0
GCK 33 14 46 23 / 60 20 0 0
EHA 31 14 46 26 / 20 10 0 0
LBL 32 15 43 24 / 60 10 0 0
HYS 32 16 43 22 / 10 20 0 0
P28 37 18 47 25 / 50 20 0 0
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Sugden
LONG TERM...Sugden
AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS JACKSON KY
320 PM EST THU DEC 17 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 315 PM EST THU DEC 17 2015
AN DRY SLOT BETWEEN A DEPARTING COLD FRONT AND INITIAL SHORTWAVE
AND AN APPROACHING UPPER TROUGH IS GRADUALLY SPREADING INTO
EASTERN KY ATTM. THIS CLEARING HAS WORKED INTO THE WESTERN HALF OF
THE AREA...WHILE LOW CLOUDS LINGER ACROSS THE FAR SOUTHEAST WHERE
A FEW WEAK RETURNS LIKELY FORM DRIZZLE LINGER NEAR THE VA BORDER
FROM PIKE COUNTY SOUTHWEST TO HARLAN COUNTY. TEMPERATURES THAT HAD
DROPPED INTO THE LOWER 40S ACROSS THE WESTERN PART OF THE AREA
HAVE RECOVERED BACK TO THE MID TO UPPER 40S.
FROM TONIGHT INTO FRIDAY...A RIDGE OVER PARTS OF THE ATLANTIC WILL
SHIFT EAST WHILE A RIDGE OVER PARTS OF THE PACIFIC BUILDS TOWARD
THE SOUTHWESTERN US. IN BETWEEN A MID LEVEL TROUGH WILL MOVE INTO
THE EASTERN CONUS WITH A SHORTWAVE APPROACHING THE LOWER OH VALLEY
TONIGHT AND THEN MOVING ACROSS THE AREA ON FRIDAY. THE HEART OF
THE COLDER AIRMASS WILL MOVE ACROSS THE AREA AT THAT POINT. AS THE
TROUGH DEPARTS ON FRIDAY EVENING AND FRIDAY NIGHT...RIDGING AT THE
SFC AND ALOFT WILL BUILD INTO THE AREA.
THE 12Z NAM AND A COUPLE OF RECENT RAP RUNS SUGGEST MOISTURE MAY
BECOME SUFFICIENTLY DEEP FOR LIGHT NON MEASURABLE PRECIPITATION
OVERNIGHT...TOWARD DAWN. TOP DOWN APPROACH OF THE FORECAST
SOUNDINGS INDICATE THAT CLOUDS WILL BE BORDERLINE INITIALLY FOR
THE PRESENCE OF ICE CRYSTALS SO IF ANYTHING FALLS LATE TONIGHT IT
MIGHT BE A FEW SPRINKLES OR VERY LIGHT DRIZZLE OR FLURRIES OR A
MIXTURE OF BOTH. HOWEVER...MODEL GUIDANCE ALSO INDICATE THAT THE
MOISTURE SHOULD BE SUFFICIENTLY DEEP FOR ICE TO BE PRESENT IN THE
CLOUDS BY AROUND DAWN ON FRIDAY. ALSO...EVEN WHERE SFC TEMPS ARE A
LITTLE BIT ABOVE THE FREEZING MARK...DRY ADIABATIC LAPSE RATES AND
RELATIVELY DRY SUB CLOUDS LAYER SHOULD LEAD TO ANY PRECIPITATION
ON FRIDAY FALLING AS SNOW. HIGHER MOMENTUM FROM STRONGER WINDS
ALOFT SHOULD ALSO MIX DOWN...WITH GUSTS AS HIGH AS 25 TO 30 MPH
POSSIBLE. THE PATTERN WILL FAVOR THE SW VALLEYS BEING A BIT
COLDER THAN AREAS TO THE NORTHEAST DUE TO EARLIER CLEARING AND A
QUICKER SLACKENING TO THE WINDS. THE COLDEST NIGHT OF THE NEXT
SEVERAL SHOULD NOT OCCUR UNTIL THE LONG TERM PERIOD...ON SATURDAY
NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 PM EST THU DEC 17 2015
THE WEEKEND WILL FEATURE A PROGRESSIVE UPPER LEVEL RIDGE AXIS
SITUATED OVER THE OH VALLEY...ALONG WITH SFC HIGH PRESSURE. THIS
WILL PROVIDE US WITH A DRY AND SUN-FILLED WEEKEND. FRIDAY NIGHT
TEMPERATURES WILL BE ON THE CHILLY SIDE WITH MOST LOCATIONS
DIPPING INTO THE MID 20S. HOWEVER...WITH AMPLE
SUNSHINE...AFTERNOON TEMPS SHOULD RECOVER INTO THE 40S WHICH IS
NEAR NORMAL FOR THIS TIME OF YEAR. WITH THE HIGH PRESSURE CENTERED
OVER US SATURDAY NIGHT...TEMPS WILL BE THE COLDEST OF THE MONTH
WITH VALLEY LOCATIONS FALLING NEAR 20 DEGREES. AS SOUTHERLY FLOW
RETURNS ON SUNDAY...TEMPS WILL BE ABOVE NORMAL YET AGAIN WITH
HIGHS WARMING INTO THE LOW 50S.
A MILD AND WET PERIOD OF WEATHER IS EXPECTED AS WE MOVE INTO THE
WORK WEEK. UPPER LEVEL FLOW WILL BE FAIRLY ZONAL WITH A SERIES OF
WEAK IMPULSES/TROUGHS MOVING THROUGH KENTUCKY. THE 12Z GFS AND 00Z
ECMWF DISAGREE ON TIMING AND AMPLIFICATION OF MANY OF THESE
IMPULSES SO HAVE CONTINUED TO BE GENERAL WITH RAIN CHANCES. THAT
BEING SAID...THE FIRST CHANCE FOR RAIN COMES ON MONDAY AS A COLD
FRONT APPROACHES THE REGION. THE FRONT IS PROGGED TO STALL OVER
KENTUCKY AS A SERIES OF WAVES MOVE ALONG THE BOUNDARY. THIS WILL
BRING CONTINUED RAIN CHANCES THROUGH THE END OF THE PERIOD. THERE
WILL BE AMPLE GULF MOISTURE FOR THESE WAVES TO TAP INTO SO RAIN
AMOUNTS COULD AMOUNT UP TO 2 OR 3 INCHES OVER THE COURSE OF THE
WEEK.
TEMPERATURES NEXT WEEK WILL AVERAGE 10-20 DEGREES ABOVE
NORMAL...POSSIBLE MAKING A RUN AT BREAKING RECORD HIGH TEMPS NEXT
WEDNESDAY AND THURSDAY. ALSO...IF WE DON/T GET ANY SNOW
ACCUMULATION ON FRIDAY...WE WILL MAKE A RUN AT THE ALL TIME LATEST
MEASURABLE SNOW AT JACKSON WHICH WAS ON DECEMBER 29TH...2001.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 135 PM EST THU DEC 17 2015
A DRY SLOT BEHIND THE COLD FRONT AND AHEAD OF AN UPPER LEVEL
TROUGH IS GRADUALLY WORKING INTO EASTERN KY AS THE LAST BIT OF
DRIZZLE AND SHOWERS HAS EXITED THE TAF SITES. A FEW HOURS OF
IMPROVEMENT TO VFR IS ANTICIPATED AT THE TAF SITES...HOWEVER THIS
MAY BE SHORT LIVED. THE LOW CLOUDS IN THE MVFR RANGE CLOSER TO
THE UPPER SYSTEM ARE ALREADY NEARING A DAY TO CVG TO SDF LINE.
THESE STRATUS AND STRATOCU SHOULD RETURN TONIGHT AND LINGER
THROUGH THE END OF THE PERIOD. SOME ISOLATED SNOW SHOWERS AND
FLURRIES WILL BE POSSIBLE GENERALLY AFTER 12Z. WINDS WILL
REMAIN 10KT OR LESS FOR MOST OF THE PERIOD OUT OF THE NORTHWEST TO
WEST...THOUGH THEY COULD INCREASE TO THE 10 TO 15KT RANGE LATE IN
THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JP
LONG TERM...JVM
AVIATION...JP
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
1116 AM CST THU DEC 17 2015
.DISCUSSION...
Issued at 408 AM CST THU DEC 17 2015
Despite the presence of a larger meridional upper trough centered
over Plains other than an extensive region of stratus expect benign
but seasonably cold conditions today. Water vapor satellite imagery
does show an elongated shortwave trough diving southeast on the
backside of the trough. All we can expect to see from this feature
is broken mid clouds later today. Of greater importance will be cold
advection stratus spreading across the CWA this morning. Following
the RUC as it`s handling these low clouds best. With the low clouds
likely to last for most if not all day the diurnal range should be
limited to around 5F.
Coldest readings of the season expected tonight as clouds clear and
drier air advects into the region. Abundant sunshine on Friday will
help temperatures recover to normal readings. However, a secondary
area of high pressure will overspread the region Friday night.
Overnight lows will dip into the middle/upper teens across the
northern 1/2 of the CWA where winds will likely go calm as the
center of the high passes overhead.
As has been advertised for the past several days warm advection will
reassert itself over the weekend as upstream upper level ridging
builds and advances eastward. Medium range models continue to
maintain run-to-run consistency in bringing a shallow fast-moving
shortwave through the Central Plains late in the weekend. They
develop an impressive low-level jet in excess of 50kts which will
pull up modified gulf moisture. The moisture remains suspect over
western MO while central MO has a much better chance of seeing rain
form due to better quality/depth of the moisture return.
The overall pattern next week remains unsettled although Monday and
Tuesday are looking dry with above average temperatures before a
progressive shortwave trough brings a chance for precipitation. With
temperatures expected to remain above freezing Tuesday night and
Wednesday rain is the preferred precipitation type.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1115 AM CST THU DEC 17 2015
MVFR ceilings are expected to persist through the afternoon before
they slide south of the terminals by this evening. Once the lower
clouds move away, VFR conditions are expected through the rest of the
forecast. Southwesterly winds will pick up by late tomorrow morning
and may gust into the 20 to 25 kt range.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...MJ
AVIATION...CDB
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
251 PM EST THU DEC 17 2015
.SYNOPSIS...
A COLD FRONT WILL CLEAR THE AREA EARLY FRIDAY...ALLOWING MUCH COOLER
AIR TO FILL IN THROUGH THE WEEKEND. WET WEATHER WILL LIKELY RETURN
EARLY NEXT WEEK...WITH TEMPERATURES SLOWLY REBOUNDING.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 215 PM...COLD FRONT EXTENDING OUT OF SFC LOW OVER NRN
ONTARIO IS NOW JUST WEST OF THE APPALACHIAN CHAIN...AND WILL
PROGRESS SLOWLY EWD INTO OUR AREA TONIGHT. A VERY SHALLOW AND MOIST
WEDGE-LIKE AIRMASS CURRENTLY SITS OVER THE CAROLINAS...SUPPORTING
WIDESPREAD LOW STRATUS WHICH HAS KEPT US COOL AND DAMP TODAY. FRONT
WILL EVENTUALLY DISPLACE THE INCUMBENT AIRMASS AND USHER IN
DRIER CONTINENTAL AIR FOR FRIDAY. WARM ADVECTION IS OCCURRING
DOWN TO WITHIN A FEW HUNDRED FEET OF THE SFC...BUT WITH THE SFC
THERMAL-MOISTURE BOUNDARY HUNG UP ALONG THE SRN BORDER OF THE CWFA
ANY CHANCE OF SURFACE BASED CONVECTION BEING INITIATED AS THE
FRONT IS VERY LOW. LATEST RAP DID RE-INTRODUCE A COUPLE HUNDRED
JOULES INTO GREENWOOD COUNTY IN THE NEXT COUPLE OF HOURS BUT THIS
IS AFTER EARLIER GUIDANCE TRENDED DOWN. EFFECTIVE SHEAR COULD
RAPIDLY REACH 40 KT OR MORE IF THE TMB DOES SNEAK NORTHWARD...BUT
THE WINDOW FOR INITIATION WILL BE SHORT. NEVERTHELESS WE CONTINUE
TO KEEP AN EYE ON THE RADAR THIS AFTERNOON FOR ANY SIGNATURES THAT
WOULD INDICATE THE SHEAR IS BEING REALIZED.
LOW-LEVEL TEMP FIELDS TONIGHT INDICATE COLD ADVECTION WILL GET
UNDERWAY GRADUALLY...TAKING FROM 00Z TO 12Z TO SET UP ACROSS THE
AREA. DRYING OCCURS EVEN MORE SLOWLY. HENCE THE EXPECTATION IS
THAT A LOT OF THE STRATUS AND PATCHY FOG WILL LINGER UNTIL AROUND
DAYBREAK IF NOT A LITTLE AFTER. NW FLOW PRECIP POTENTIAL IS SMALL
GIVEN THE VERY SHALLOW NATURE OF THE PROGGED MOISTURE ALONG THE
TENN BORDER. TEMPS WILL BE TOO WARM FOR SNOW MUCH OF THE NIGHT
ANYWAY. HOWEVER...CONTINUED CAA THRU THE DAY AND A SECOND SHOT OF
MOISTURE ARRIVING IN THE AFTERNOON WILL EVENTUALLY SUPPORT SOME
PRECIP...WHICH MOSTLY WILL FALL AS SNOW. AS WE OFTEN SEE...THE WINDS
ARE BECOMING MOST FAVORABLE RIGHT AS THE RH TAPERS OFF. A COUPLE
TENTHS MIGHT RESULT IN THE LATE AFTERNOON NEAR THE BORDER...BUT NO
ADVISORY CURRENTLY IS WARRANTED. WINDS WILL BECOME GUSTY ACROSS
THE AREA AS THE CAA SETS IN. INVERSION ATOP THE BOUNDARY LAYER
LOOKS TO LIMIT MIXING JUST ENOUGH TO KEEP WINDS BELOW ADVISORY
CRITERIA...THOUGH A FEW GUSTS TO NEAR 40 KT ARE POSSIBLE ON THE
HIGHEST RIDGES.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 130 PM...THE NAM AND SOME OF THE HIGH RES MODELS SHOW THAT
PERHAPS OUR BEST WINDOW FOR ANY ACCUMULATING SNOW SHWRS WILL BE
EARLY FRIDAY EVENING...AS FLOW VEERS MORE DUE NWLY AND ORTHOGONAL TO
THE TN/NC BORDER WHILE 850 MB TEMPS PLUMMET TO AROUND -8C. FROM
THERE...THE RH DEPTH DECREASES AND FLOW BEGINS TO DIMINISH AS WELL.
SO WILL START OUT WITH A SLGT CHC OF SNOW SHWRS IN THE EVENING...BUT
GOING DRY BY DAYBREAK SATURDAY. ONLY A DUSTING TO HALF INCH OF SNOW
EXPECTED...MAINLY ABOVE 3500 FT. IT WILL BE BREEZY IN THE
MTNS...WITH POTENTIAL FOR NEAR WIND ADV CRITERIA GUSTS ABOVE 3500 FT
OVERNIGHT. TEMPS WILL DROP INTO THE TEENS AND 20S IN THE MTNS UNDER
THE STRONG CAA...AND GENERALLY UPR 20 TO LWR 30S ACRS THE PIEDMONT.
SATURDAY THRU SUNDAY...COOL HIGH PRES WILL QUICKLY BUILD IN FROM THE
WEST...RESULTING IN MAINLY CLEAR SKIES AND BELOW NORMAL TEMPS. HIGHS
WILL BE 30S TO MID 40S IN THE MTNS ON SATURDAY...WITH UPR 40S TO LWR
50S IN THE PIEDMONT. LOWS IN THE 20S TO LWR 30S SATURDAY NIGHT. THEN
SLIGHTLY WARMER ON SUNDAY (40S TO LWR 50S MTNS AND LWR 50S NW
PIEDMONT TO UPR 50S IN THE UPR SAVANNAH VALLEY).
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 210 PM EST THURSDAY...THE MEDIUM RANGE FCST PICKS UP AT 00Z ON
MONDAY WITH BROAD UPPER RIDGING MOVING ACROSS THE EASTERN CONUS AS
AN UPPER SHORTWAVE RIPPLES ACROSS THE CENTRAL PLAINS. OVER THE NEXT
DAY OR TWO...THE RIDGE AXIS WILL MOVE OFFSHORE AS HEIGHTS FALL OVER
THE SE REGION. SIMULTANEOUSLY...BROAD AND DEEP UPPER TROFFING WILL
BEGIN TO DEVELOP OVER THE CENTRAL CONUS AS A VERY STRONG UPPER HIGH
PERSISTS OVER BERMUDA. BY THE END OF THE MEDIUM RANGE ON THURS...THE
LONG RANGE MODELS BEGIN TO DIVERGE WRT TO THE DISSIPATION OF THE
UPPER TROF. THE LATEST 12Z GFS RUN HAS A MORE AMPLIFIED TROF
PERSISTING THRU THURS COMPARED TO THE 00Z ECMWF WHICH IS FASTER TO
LIFT THE TROF AND TRIES TO REBUILD RIDGING OVER THE GULF OF MEX
SOONER.
AT THE SFC...STRONG HIGH PRESSURE WILL BE SLIDING EAST OF THE REGION
BY EARLY MON AS THE NEXT COLD FRONT APPROACHES THE CAROLINAS FROM
THE WEST. THERE IS GOOD AGREEMENT AMONG THE LONG RANGE MODELS THAT
THE COLD FRONT SHOULD MOVE INTO THE CWFA BY LATE MON...HOWEVER
BEYOND THIS POINT THE MODELS DIVERGE FOR THE REMAINDER OF THE
PERIOD. THE GFS HAS A CLEANER FROPA OVERALL AND BRIEFLY RETURNS HIGH
PRESSURE OVER THE AREA FOR TUES. DURING THE REST OF THE PERIOD...IT
DEVELOPS A SERIES OF LOWS TO OUR WEST AND NW AND FINALLY MOVES
ANOTHER COLD FRONT TO OUR DOORSTEP BY THE VERY END OF THE PERIOD.
THE ECMWF...ON THE OTHER HAND...MAINTAINS A STRONGER SUBTROPICAL SFC
HIGH TO OUR EAST AND LAYS THE INITIAL COLD FRONT ACROSS OUR NORTHERN
FRINGE ON MON/TUES. IT ALSO TRIES TO DEVELOP NUMEROUS SFC LOWS TO
OUR WEST OVER THE NEXT FEW DAYS WHILE SIMULTANEOUSLY KEEPING MOIST
SELY FLOW OVER THE REGION. I BELIEVE IT IS STILL TOO EARLY TO HAVE A
FIRM GRASP WRT HOW THE SFC PATTERN WILL PLAY OUT...BUT THE OVERALL
PATTERN SHOULD RESULT IN WARMING TEMPS AND SOLID TO LIKELY CHANCES
FOR PRECIP FOR MOST OF THE PERIOD.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AT KCLT...TOUGH FCST THRU TONIGHT AS COLD FRONT ATTEMPTS TO
DISPLACE A WEAK WEDGE OF HIGH PRESSURE. PATTERN IS GENERALLY NOT
BEING HANDLED WELL BY ANY OF THE AVN GUIDANCE...BUT LAMP CIG
TRENDS APPEAR TO BE DOING BEST. IT APPEARS THE WEDGE BOUNDARY
WILL REMAIN SOUTH OF THE FIELD THRU THE EVENING...WITH COLD FRONT
LOSING STEAM AS IT ENTERS THE PIEDMONT TONIGHT. FOR THESE REASONS
LIFR TO IFR CIGS ARE NOT EXPECTED TO IMPROVE FOR GOOD UNTIL AFTER
DAYBREAK FRI...WHEN SCOURING COLD ADVECTION FINALLY BEGINS. IT IS
POSSIBLE SFC WARMING WILL BE ENOUGH TO BRIEFLY MIX CIG UP TO IFR
FOR A TIME THIS AFTN...BUT ANY IMPROVEMENT WILL BE BRIEF. WINDS ARE
PARTICULARLY HARD TO PIN DOWN WITH NO GUIDANCE CORRECTLY DEPICTING
THE LIGHT MAINLY NE-LY WINDS IN THE WEDGE. MOST LIKELY DIR IS N
TO NE UNTIL TONIGHT WHEN THEY SHOULD GO SOUTHERLY JUST PRIOR TO
FROPA...EVENTUALLY NW AFTER FROPA. GUSTS WILL THEN PICK UP AS WELL
IN THE COLD ADVECTIVE PATTERN.
ELSEWHERE...CONCERNS ARE SIMILAR TO KCLT...THE REMNANT WEDGE
AIRMASS ALLOWING POOR FLIGHT CONDITIONS TO HANG ON. IMPROVEMENT
DOES APPEAR A LITTLE MORE LIKELY WITH PRECIP PLAYING LESS OF A ROLE
IN THE FCST...ALLOWING FOR MAINLY MVFR VSBY AND POTENTIAL FOR CIGS
TO LIFT TO IFR. HOWEVER SAME STORY AS FAR AS THE LIMITED ABILITY
OF THE SLOW-MOVING FRONT TO SCOUR CIGS OVERNIGHT. WINDS WILL BE
LIGHT AND VARIABLE...BECOMING SW PRIOR TO FROPA AND VEERING TO
W/NW FOLLOWING. DECENT GUSTS WILL OCCUR OVERNIGHT AT KAVL AND
CONTINUE INTO FRIDAY UNDER COLD ADVECTION. SOME POTENTIAL FOR
A GAP WIND DOES EXIST SO KGSP/KGMU MAY SEE BREEZY CONDITIONS
OVERNIGHT. BECOMING VFR SOON AFTER DAYBREAK.
OUTLOOK...HIGH PRESSURE WILL BUILD OVER THE SE CONUS FRI INTO THE
WEEKEND. CONDITIONS SHOULD FAVOR VFR...WITH THE POSSIBILITY OF MTN
VALLEY FOG EACH MORNING. A COLD FRONT COUPLED WITH LOW PRESSURE
PASSING NEARBY WILL SPREAD LOW CEILINGS AND RAIN ACROSS THE REGION
EARLY NEXT WEEK.
CONFIDENCE TABLE...
20-02Z 02-08Z 08-14Z 14-18Z
KCLT HIGH 80% MED 70% MED 64% HIGH 91%
KGSP MED 76% LOW 59% LOW 49% HIGH 100%
KAVL MED 64% LOW 58% HIGH 83% HIGH 100%
KHKY MED 68% LOW 51% LOW 52% HIGH 100%
KGMU MED 68% MED 63% MED 73% HIGH 100%
KAND LOW 54% LOW 47% HIGH 97% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...WIMBERLEY
NEAR TERM...WIMBERLEY
SHORT TERM...HG
LONG TERM...HG
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
352 PM CST THU DEC 17 2015
.DISCUSSION...
CURRENTLY...AS OF 3PM...
TEMPERATURES ACROSS THE MID-SOUTH ARE MUCH COOLER THAN THEY HAVE
BEEN OVER THE LAST WEEK OR SO WITH READINGS IN THE MID 40S TO MID
50S. LATEST WATER VAPOR IMAGERY SHOWS A LARGE TROUGH DOMINATING
THE MIDDLE UNITED STATES WITH RIDGING OVER THE WEST COAST AND
JUST OFF THE EAST COAST. SURFACE ANALYSIS PLACES A COLD FRONT OVER
THE APPALACHIAN MOUNTAINS WITH AN AREA OF LOW PRESSURE NEAR THE
TEXARKANA ALONG WITH A WEAK SURFACE COLD FRONT.
SHORT TERM...TONIGHT THROUGH SUNDAY...
DRY AND SEASONABLE WEATHER IS EXPECTED THROUGH THIS PERIOD AS HIGH
PRESSURE WILL BUILD INTO THE REGION BOTH ALOFT AND AT THE SURFACE.
FOR TONIGHT...A WEAK COLD FRONT WILL PUSH THROUGH THE MID-SOUTH.
LIMITED LOW LEVEL MOISTURE WILL RESULT IN ONLY MID AND UPPER LEVEL
CLOUDINESS THROUGH SUNRISE TOMORROW. BEHIND THE FRONT...SLIGHTLY
COLDER AND DRIER AIR WILL MOVE INTO THE REGION DURING THE
AFTERNOON TOMORROW. WENT AHEAD AND SLIGHTLY UNDERCUT GUIDANCE
HIGHS FOR FRIDAY AS 850 MB TEMPS WILL REMAIN IN THE -5 TO -8 C
RANGE.
SATURDAY WILL BE ABOUT 10 DEGREES WARMER WITH HIGHS MAINLY
IN THE MIDDLE 50S UNDER ABUNDANTLY SUNNY SKIES. SURFACE HIGH
PRESSURE WILL BEGIN TO PUSH EAST BY LATE SATURDAY NIGHT. WEAK
RETURN FLOW WILL SETUP ACROSS THE REGION SUNDAY AFTERNOON AND
TEMPERATURES WILL BE SLIGHTLY WARMER WITH READINGS IN MID TO
UPPER 50S. UPPER LEVEL FLOW WILL SHIFT SOUTHWESTERLY AS A
SHORTWAVE TROUGH DIGS ACROSS THE CENTRAL PLAINS.
LONG TERM...SUNDAY NIGHT THROUGH LATE NEXT WEEK...
MILD AND UNSETTLED WEATHER WILL BE THE STORY FOR MUCH OF
CHRISTMAS WEEK. A DEEPENING SURFACE LOW AND ASSOCIATED COLD FRONT
WILL BEGIN TO PUSH ACROSS THE MISSISSIPPI VALLEY ON MONDAY.
NUMEROUS SHOWERS WILL BE POSSIBLE ACROSS THE MID-SOUTH FOR MUCH OF
THE DAY ON MONDAY. LATEST GUIDANCE SUGGESTS THAT THE FRONT MAY
BECOME STALLED ACROSS THE AREA AND SERVE AS A FOCUS FOR MORE
SHOWER AND STORM INITIATION ON BOTH TUESDAY AND WEDNESDAY.
MULTIPLE UPPER LEVEL DISTURBANCES EMBEDDED IN SOUTHWEST FLOW
ALOFT WILL MOVE THROUGH THE REGION ON TUESDAY AND WEDNESDAY
KICKING OFF SHOWERS AND THUNDERSTORMS. LATEST GUIDANCE SHOWS
INSTABILITY INCREASING AS DEWPOINTS APPROACH THE LOWER 60S.
TEMPERATURES WILL REMAIN VERY MILD WITH HIGH TEMPERATURES IN THE
MID TO UPPER 60S THROUGH LATE NEXT WEEK.
AC3
&&
.AVIATION...
18Z TAFS
12Z NAM BUFR SOUNDINGS AND HRRR CIG PRODUCTS SUGGEST MVFR DECK
OVER MO/IL WILL PASS MAINLY TO THE EAST OF MEM LATE THIS EVENING.
IN THE INTERIM... MEM NORTH WIND COMPONENT SHOULD FALL BELOW THE
7KT THRESHOLD BY MIDAFTERNOON...WITH VFR PREVAILING.
VFR ANTICIPATED EVENING MEM ARRIVAL PUSH...WITH LIGHT WINDS.
SHOULD A POST FRONTAL BKN MVFR CLOUD DECK DEVELOP AT MEM AFTER
06Z...IT SHOULD PREVAIL ABOVE FL015.
CLEAR SKIES AND INCREASED NORTHWEST WINDS WILL DAYTIME MIXING
AFTER SUNRISE FRIDAY. WINDS SHOULD DIMINISH BY LATE FRIDAY
AFTERNOON...WITH CLEAR AND NEARLY CALM CONDITIONS FRIDAY EVENING.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
317 PM EST THU DEC 17 2015
.SHORT TERM (TONIGHT THROUGH TOMORROW)...
IT HAS BEEN A CLOUDY-RAINY DAY ACROSS THE FORECAST AREA WITH A COLD
FRONT TRYING TO MAKE ITS WAY THROUGH THE MOUNTAINS. CURRENT WATER
VAPOR AND RAP UPPER AIR ANALYSIS INDICATE A LONGWAVE TROUGH ACROSS
THE CENTRAL U.S. WITH A RIDGE ALONG THE EASTERN SEABOARD AND ANOTHER
RIDGE BACK TO THE WEST ACROSS THE PACIFIC COAST. LOOKING AT THE
RADAR...SCATTERED SHOWERS CONTINUE ACROSS THE EASTERN HALF OFF THE
AREA BUT ARE COMING TO AN END FROM WEST TO EAST. THERE ARE A FEW PEAKS
OF SUNSHINE ACROSS THE WESTERN COUNTIES AND THERE WILL CONTINUE TO
BE SOME GRADUAL CLEARING THROUGH SUNSET. FURTHER TO
THE NORTHWEST...CLOUD COVER CAN BE NOTED ALONG A SECONDARY COLD
FRONT THAT IS NEARING THE OHIO RIVER. WITH THIS SAID...CLOUD COVER
SHOULD BUILD BACK INTO THE REGION OVERNIGHT WITH A REINFORCING
SHOT OF COLD AIR. OVERNIGHT LOWS WILL BE NOTICEABLY COOLER WITH
TEMPERATURES TOMORROW MORNING STARTING OUT IN THE MID 20S TO LOW
30S.
THE TROUGH AXIS WILL PASS THROUGH THE AREA TOMORROW WITH 850MB
TEMPERATURES DROPPING DOWN INTO THE -7 TO -9 DEGREES CELSIUS RANGE.
MODEL SOUNDINGS INDICATE THAT MOISTURE WILL LINGER IN THE LOW
LEVELS BELOW 800-850MB. OROGRAPHIC LIFT WITH LOW LEVEL AND MID-
LEVEL WINDS FROM THE NORTHWEST WILL AID IN THE DEVELOPMENT OF SNOW
SHOWERS ACROSS THE HIGH TERRAIN DURING THE DAY TOMORROW. THE
MOISTURE IS RATHER SHALLOW AND THE LIFT NOT ALL THAT IMPRESSIVE
AND OVERALL THINK THE SNOWFALL WILL BE LIGHT. COLD AIR WILL
CONTINUE TO ADVECT INTO THE AREA AND THE ATMOSPHERE SHOULD BE
COMPLETELY BELOW FREEZING ACROSS THE HIGHER ELEVATIONS.
OVERALL...EXPECT SNOWFALL ACCUMULATIONS OF UP A HALF AN INCH WILL
BE POSSIBLE FOR THE HIGHEST PEAKS SUCH AS LECONTE. MOISTURE WILL
EXIT THE REGION AROUND 00Z SATURDAY.
.LONG TERM (FRIDAY NIGHT THROUGH THURSDAY)...
ANY LINGERING SHOWERS FROM AN EXITING WEATHER SYSTEM SHOULD END BY
FRIDAY EVENING WITH DRY AIR MOVING IN. THEREFORE...THE EARLY PART
OF THE EXTENDED WILL BEGIN WITH DRY CONDITIONS. THIS WILL CONTINUE
THROUGH THE WEEKEND. COOLER AIR BEHIND THE SYSTEM WILL BE SHORT
LIVED AS A WARMING TREND DEVELOPS OVER THE SOUTHERN APPALACHIAN
REGION SATURDAY AND SUNDAY. THE NEXT SYSTEM OF CONCERN WILL BE A
COLD FRONT MOVING IN ON MONDAY. THE FRONTAL BOUNDARY WILL BRIEFLY
LINGER TO OUR SOUTH BEFORE PULLING NORTH THEN EAST AND BACK INTO
THE MRX CWA LATE TUESDAY INTO WEDNESDAY. THIS WILL PROVIDE THE AREA
WITH ADDITIONAL BANDS OF SHOWERS THROUGH THE REST OF THE EXTENDED.
WITH THE ONGOING WARMING TREND...DAYTIME HIGHS SHOULD REACH INTO
THE 60S ACROSS MUCH OF THE TN VALLEY FOR MID WEEK. WITH THE WARM
DECEMBER TEMPERATURES... PRECIP SHOULD FALL AS RAIN.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 33 46 29 50 / 10 10 10 10
KNOXVILLE MCGHEE TYSON AIRPORT, TN 33 42 27 47 / 10 10 10 10
OAK RIDGE, TN 32 43 27 47 / 0 10 10 10
TRI CITIES AIRPORT, TN 34 39 23 41 / 10 10 10 10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
MA/MJB
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1154 AM CST THU DEC 17 2015
.UPDATE...
UPDATED FOR 18Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 1009 AM CST THU DEC 17 2015/
UPDATE...
QUICK UPDATE TO REMOVE MORNING WORDING FROM THE ZONES AND CLOUDS
OVER NORTHEAST MISSISSIPPI. THE REST OF THE FORECAST IS IN GREAT
SHAPE WITH HIGHS TOPPING OUT IN THE UPPER 40S AREAWIDE UNDER
ABUNDANTLY SUNNY SKIES.
AC3
PREV DISCUSSION... /ISSUED 342 AM CST THU DEC 17 2015/
DISCUSSION...
AFTER A FRONTAL PASSAGE ON WEDNESDAY...COOLER AND DRIER WEATHER
IS FORECAST FOR FRIDAY THROUGH THE WEEKEND. BY NEXT
WEEK...SIGNIFICANTLY WARMER TEMPERATURES ARE EXPECTED WITH
MULTIPLE CHANCES FOR RAIN AND THUNDERSTORMS AS ACTIVE WEATHER
RETURNS TO THE MID-SOUTH...
ALOFT...A MEAN LONGWAVE TROUGH WAS CENTERED THROUGH THE CONUS WITH
A MATURE AND FILLING CYCLONE EXITING INTO THE CANADIAN PROVINCES.
AT THE SURFACE...A FRONTAL BOUNDARY EXTENDING FROM THE
AFOREMENTIONED LOW PRESSURE WAS LOCATED IN SOUTHEAST
AL...EXTENDING TO POINTS NORTHEAST. A FEW SHOWERS WERE LINGERING
ACROSS NORTHEAST MISSISSIPPI BUT THE MAJORITY OF THE PRECIP HAS
EXITED THE MID-SOUTH. A PROGRESSIVE SURFACE HIGH PRESSURE WAS
BEGINNING TO BUILD INTO THE SOUTHERN PLAINS WITH RISING PRESSURES
THROUGHOUT THE MID-SOUTH.
THURSDAY BEGINS A STRETCH OF COOLER AND DRIER WEATHER LASTING
THROUGH MUCH OF THE WEEKEND. A STRONG SURFACE HIGH PRESSURE WILL
BUILD INTO THE MID-SOUTH ON THURSDAY IN THE WAKE OF A DEPARTING
LOW PRESSURE SYSTEM. THURSDAY WILL FEEL COOLER...BUT TEMPERATURES
WILL ACTUALLY BE CLOSE TO SEASONAL NORMALS. LOW TEMPERATURES ON
THURSDAY NIGHT WILL DROP INTO THE UPPER 20S AND LOWER 30S FOR
MOST...BUT RADIATIONAL COOLING WILL NOT BE OPTIMIZED GIVEN
WESTWARD DISPLACEMENT OF THE SURFACE HIGH.
ON FRIDAY...A SECONDARY PUSH OF COLDER AIR MOVES INTO THE MID-
SOUTH WITH 850 MB TEMPERATURES STILL FORECAST TO DROP TO NEAR -5 C
AROUND NOON. CONTINUED THE TREND OF LOWERING HIGHS FOR FRIDAY
GIVEN THAT THE APEX OF COLD AIR WILL BE OVERHEAD DURING PEAK
HEATING. SUNSHINE SHOULD ALLOW HIGH TEMPERATURES TO BREAK 40
DEGREES IN MOST LOCATIONS...BUT THIS WILL CERTAINLY BE THE COOLEST
DAY OF THE PERIOD. FRIDAY NIGHT WILL ALSO BE THE COLDEST NIGHT OF
THE PERIOD WITH THE SURFACE HIGH CENTERING ITSELF OVER THE MID-
SOUTH. MID TO UPPER 20S ARE EXPECTED ACROSS FAVORED AREAS OF THE
TENNESSEE RIVER VALLY AND NORTHEAST MISSISSIPPI. WEAK RETURN FLOW
DOES ATTEMPT TO ESTABLISH ITSELF FRIDAY MORNING FOR AREAS ALONG
AND WEST OF THE MISSISSIPPI RIVER...BUT A COLD NIGHT IS STILL
EXPECTED HERE.
SATURDAY AND SUNDAY WILL BE SUNNY AND COOL WITH HIGHS IN THE 50S
AND LOWS IN THE 30S. SUNDAY WILL MOST LIKELY BE A BIT WARMER THAN
SATURDAY AS RETURN FLOW AND STRONGER WARM AIR ADVECTION
ESTABLISHES ITSELF ACROSS THE MID-SOUTH...ESPECIALLY WEST OF THE
MISSISSIPPI RIVER AS A PRESSURE GRADIENT TIGHTENS CONSEQUENCE OF A
DEEPENING LEE LOW PRESSURE SYSTEM. THIS WILL MARK THE BEGINNING OF
AN EXCEPTIONALLY WARM PERIOD THAT WILL LIKELY EXTEND INTO AND
PERHAPS PAST THE 8-14 DAY TIME RANGE.
IN THE LONG-TERM...SEVERAL SYSTEMS OF CONSEQUENCE WILL MOVE
THROUGH THE MIDSOUTH. WHILE TOO EARLY TO FOCUS ON DETAILS...IT
DOES LOOK AS THOUGH MOISTURE WILL HAVE AMPLE TIME TO RETURN TO THE
MID-SOUTH AS THE GULF OF MEXICO OPENS. A RETREATING WARM FRONT
WILL WAVER THROUGH THE AREA WHICH WILL LIKELY BE THE FOCUS OF
SHOWERS AND THUNDERSTORMS. A VERY STRONG SHORTWAVE WILL EJECT AND
ALSO ACT TO AMPLIFY A PROGRESSIVE LONG-WAVE TROUGH SOMETIME AROUND
MID-WEEK. AN ASSOCIATED SURFACE LOW WILL DEVELOP ACROSS THE
CENTRAL HIGH PLAINS AND TRACK INTO THE GREAT LAKES REGION AROUND
THE WEDNESDAY TIME FRAME. THIS LOOKS LIKE THE BEST PERIOD FOR
SHOWERS AND THUNDERSTORMS AS CONSISTENCY BETWEEN MODELS AND
BETWEEN MODEL RUNS HAS BEEN RELATIVELY GOOD. IT IS TOO EARLY TO
ASSESS SEVERE POTENTIAL AT THIS TIME...HOWEVER.
TVT
&&
.AVIATION...
18Z TAFS
12Z NAM BUFR SOUNDINGS AND HRRR CIG PRODUCTS SUGGEST MVFR DECK
OVER MO/IL WILL PASS MAINLY TO THE EAST OF MEM LATE THIS EVENING.
IN THE INTERIM... MEM NORTH WIND COMPONENT SHOULD FALL BELOW THE
7KT THRESHOLD BY MIDAFTERNOON...WITH VFR PREVAILING.
VFR ANTICIPATED EVENING MEM ARRIVAL PUSH...WITH LIGHT WINDS.
SHOULD A POST FRONTAL BKN MVFR CLOUD DECK DEVELOP AT MEM AFTER
06Z...IT SHOULD PREVAIL ABOVE FL015.
CLEAR SKIES AND INCREASED NORTHWEST WINDS WILL DAYTIME MIXING
AFTER SUNRISE FRIDAY. WINDS SHOULD DIMINISH BY LATE FRIDAY
AFTERNOON...WITH CLEAR AND NEARLY CALM CONDITIONS FRIDAY EVENING.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
145 PM EST THU DEC 17 2015
.SYNOPSIS...
A COLD FRONT CROSSES THE AREA TODAY WITH WIDESPREAD RAINFALL. THIS
FRONT WILL BE ALONG THE COAST BY FRIDAY MORNING. A STRONG UPPER
LEVEL TROUGH WILL BRING US BACK COLDER TEMPERATURES INTO THE
WEEKEND...BUT THIS WILL BE SHORT-LIVED. ANOTHER COLD FRONT WILL
MAKE ITS WAY TOWARDS THE REGION AND IMPACT THE AREA MONDAY INTO
TUESDAY OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM EST THURSDAY...
A COLD FRONT WILL CONTINUE PROGRESSING EASTWARD ACROSS THE REGION
THIS AFTERNOON. LIGHT TO MODERATE RAIN WILL CONTINUE IN ADVANCE OF
IT...BUT THE BULK OF IT IS EXPECTED TO EXIT THE EASTERN PORTION OF
THE AREA WITHIN THE NEXT FEW HOURS. ADDITIONAL LIGHT RAIN SHOWERS
ARE EXPECTED BEHIND THE FRONT AS NORTHWEST UPSLOPE CONDITIONS
DEVELOP. MOST OF THESE WOULD BE OVER SOUTHEAST WEST
VIRGINIA...SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA.
WHILE MOST AREAS WILL EXPERIENCE CLOUDY SKIES...SOME BREAKS IN THE
OVERCAST WILL BEING TO BE POSSIBLE AS A DOWNSLOPE COMPONENT BEGINS
TO FORM EAST OF THE CREST OF THE BLUE RIDGE.
AS OF 1030 AM EST THURSDAY...
WIDESPREAD LIGHT TO MODERATE RAIN WAS STILL OCCURRING ACROSS THE
REGION AS A COLD FRONT ENTERS THE FAR WESTERN SECTION OF THE
FORECAST AREA. PRECIPITATION WILL CONTINUE IN ADVANCE OF THIS
FRONT HEADING INTO THE AFTERNOON. DURING THE AFTERNOON HOURS...THE
FRONT WILL CROSS THE REGION...AND AS A RESULT...THE ASSOCIATION
PRECIPITATION SHIELD WILL ALSO PROGRESS EASTWARD WITH
IT...BRINGING DECREASING COVERAGE OF PRECIPITATION TO WESTERN
PARTS OF THE AREA FIRST. LATER IN THE AFTERNOON...PRECIPITATION IS
EXPECTED TO INCREASE AGAIN ACROSS THE PREFERRED UPSLOPE AREAS OF
SOUTHEAST WEST VIRGINIA...SOUTH INTO THE NORTHERN MOUNTAINS OF
NORTH CAROLINA AS NORTHWEST FLOW BEHIND THE FRONT STARTS TO
INCREASE.
AS OF 622 AM EST THURSDAY...
LATEST RADAR SHOWING BROAD AREA OF RAIN OVER MOST OF THE FORECAST
AREA. THE 11Z RAP MESOANALYSIS SHOWED BEST UPPER DIVERGENCE NOW
OVER SE WV EAST TO LYH-RIC. THERE IS SOME WEAKENING TO THE SOUTH
TO THE RAIN. AT THIS TIME...HRRR DEPICTING THINGS THE BEST. GIVEN
THIS...WILL STILL SEE GREATEST CONCENTRATION OF RAIN THROUGH EARLY
AFTERNOON...THEN SHOULD SEE A DRYING TREND IN THE WEST...AND
FASTER MOVING OUT THIS EVENING OF THE RAIN...SO SPED UP THE DRYING
WITH THIS UPDATE.
PREVIOUS DISCUSSION FROM EARLY THIS MORNING...
FRONTAL BOUNDARY EARLY THIS MORNING STRETCHES FROM A 990MB LOW
OVER THE NRN TIP OF LAKE SUPERIOR SOUTHWARD INTO CENTRAL KY/MID
TN...WITH A WEAK LOW PRESSURE WAVE OVER ERN KY ALONG A WARM
FRONTAL BOUNDARY. RADAR INDICATING LIGHT TO AT TIMES MODERATE RAIN
MOVING NNE ACROSS THE NC INTO SOUTHSIDE VA AND OVER WV/FAR SW VA.
MODELS IN AGREEMENT ON THE SYNOPTICS...THOUGH SOME DIFFERENCES ON
PLACEMENT OF HIGHER QPF...WITH THE NAM A LITTLE WEST OF THE
GFS/ECMWF.
EARLY THIS MORNING THE BEST UPPER DIVERGENCE WITH THE 140KT 300MB
JET WAS OVER ERN TN INTO THE NC PIEDMONT. THE GFS PICKED UP ON THIS
UPPER PATTERN WELL AND GENERALLY FOLLOWED ITS SOLUTION BLENDED WITH
THE ECMWF. THE QPF WILL BE HIGHEST ALONG AND EAST OF THE BLUE RIDGE
WHICH WE HAVE BEEN ADVERTISING THE PAST 2 DAYS. EXPECT THE RAIN TO
BE HEAVY AT TIMES TODAY IN ASSOCIATION WITH A STRONGER LOW LVL JET
MOVING IN FROM UPSTATE SC AT 7AM INTO THE VA/NC PIEDMONT BY NOON.
STRONG PRESSURE FALLS OVER THE MID ATLANTIC THIS AFTERNOON INDICATES
POTENTIAL FOR THAN ONE WAVE OF LOW PRESSURE TO FORM ALONG THE FRONT.
DIFFICULT TO SEE HOW SLOW AND HOW FAR WEST THE RAIN WILL LINGER INTO
THE PIEDMONT INTO EARLY EVENING...SO KEPT SOME HIGHER POPS EAST OF A
LYNCHBURG TO MARTINSVILLE LINE...THEN TAPER TO CHANCE BY MIDNIGHT.
EXPECT CATEGORICAL POPS AREA WIDE THROUGH MOST OF THE DAY WITH
DEEPER MOISTURE POISED TO MOVE OUT OF THE MOUNTAINS BY DUSK...THOUGH
LOW LVL MOISTURE REMAIN ACROSS THE WESTERN SLOPES THROUGH TONIGHT.
ALTHOUGH THE STORM PREDICTION CENTER HAS A GENERAL THUNDER RISK INTO
THE PIEDMONT...APPEARS THAT INSTABILITY IS NIL...AND MAINLY HAVING
STRONG JET DYNAMICS TO AID IN LIFT...SO ANY THUNDER WOULD BE PRESSED
FURTHER EAST TOWARD THE COAST WHERE THERE IS A BETTER ENVIRONMENT
FOR THAT THIS AFTERNOON. STILL SOME STRONGER CONVECTIVE ELEMENTS
COULD MOVE ACROSS THE PIEDMONT OF VA/NC THROUGH MID AFTERNOON.
RAINFALL AMOUNTS FROM EARLY THIS MORNING THROUGH THURSDAY EVENING
WILL RANGE FROM 1 TO 1.25 ALONG/EAST OF THE BLUE RIDGE WITH LOCALLY
HIGHER AMOUNTS POSSIBLE. WEST...EXPECT THREE QUARTERS TO AN INCH.
SEE HYDRO SECTION BELOW FOR COMMENTS ABOUT IMPACTS ON
STREAMS/RIVERS.
TEMPERATURES THIS MORNING WILL STAY STEADY OR SLOWLY RISE BUT WITH
RAINFALL MOVING IN...GOING TO SEE HIGHS HELD IN CHECK WITH LOWER TO
MID 50S MOST AREAS...AND UP TO 60 IN SOUTHSIDE VA INTO NW NC
PIEDMONT. STILL THIS ABOUT 5-10 DEGREES ABOVE NORMAL.
TONIGHT...AS THE 8H FRONT MOVES EAST...STRONGER COLD ADVECTION
SLIDES INTO THE MOUNTAINS. MOISTURE DEPTH OVERALL IS SUFFICIENT FOR
SOME LIGHT RAIN CHANGING TO SNOW SHOWERS AFTER MIDNIGHT...THOUGH
ACCUMULATION THROUGH DAWN IS GOING TO BE LITTLE/NONE. TEMPS MAY
STAY ELEVATED ACROSS THE PIEDMONT UNTIL A LATE DROP. AS SUCH HAVE
LOWS RANGING FROM THE LOWER 30S ACROSS THE WESTERN SLOPES TO MID
30S NEW RIVER VALLEY/BLUE RIDGE...UPPER 30S TO LOWER 40S ROANOKE
TO LYNCHBURG...AND FOOTHILLS...WITH MID TO UPPER 40S FROM
FARMVILLE TO YADKINVILLE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 249 AM EST THURSDAY...
A COLD FRONT WILL MOVE OFF THE EAST COAST FRIDAY SENDING
TEMPERATURES DOWN INTO THE 30S AND 40S FRIDAY AFTERNOON. SINCE THE
WEATHER HAS BEEN VERY WARM FOR THE LAST COUPLE OF WEEK...THIS DROP
IN TEMPERATURES WILL SEEM LIKE AN ARCTIC AIRMASS...BUT IN REALITY
TEMPERATURES WILL BE SEASONAL FOR ONCE. THOSE WHO ARE NOT FANS OF
COLD WEATHER WILL BE HAPPY WHEN WARMER THAN NORMAL TEMPERATURES
RETURN ON SUNDAY.
THROUGH THE DAY FRIDAY...85H TEMPERATURES WILL CONTINUE TO FALL AS
COLD AIR RUSHES IN ON NORTHWEST FLOW. HIGH TEMPERATURES FRIDAY WILL
LIKELY OCCUR DURING THE MORNING FOR THE MOUNTAINS AND EARLY
AFTERNOON IN THE PIEDMONT. DESPITE MORNING TEMPERATURES BEING IN THE
UPPER 30S TO LOWER 40S...WILL KEEP ANY MOUNTAIN PRECIPITATION AS
SNOW AS LOW LEVEL WARM BOUNDARY LAYER WILL BE SHALLOW. SOME SNOW
ACCUMULATIONS ARE POSSIBLE DURING THE DAY FRIDAY FOR THE HIGHER
ELEVATIONS OF SE WV ABOVE 3000 FEET. BELOW 3000 FEET...GROUND
TEMPERATURES SHOULD REMAIN WARM THROUGH THE DAY TO KEEP ANY
ACCUMULATION TO A DUSTING OR LESS ON ELEVATED SURFACES AND ONLY
ALONG WESTERN SLOPES. AROUND 400 PM INTO THE NIGHT...ACCUMULATIONS
CHANCES INCREASE ALONG HIGHER ELEVATIONS AND WESTERN SLOPES FROM SE
WV...MOUNTAIN EMPIRE AND GRAYSON HIGHLAND OF SW VA AND THE NC HIGH
COUNTY. THIS UPSLOPE EVENT IS LACKING MOISTURE AND ACCUMULATIONS MAY
AMOUNT TO AN INCH OR SO FROM DRY SNOW. THE UPPER LEVEL TROUGH PIVOTS
TO THE MID ATLANTIC COAST SATURDAY MORNING...ENDING THIS BRIEF
UPSLOPE EVENT. PRESSURE RISES BEHIND THE FRONT FRIDAY AND FRIDAY
NIGHT WILL ALSO BRING BREEZY AND GUSTY WINDS TO THE FORECAST AREA.
THIS WIND MAY BE ENOUGH TO PUSH FLURRIES TO THE BLUE RIDGE FRIDAY
AFTERNOON AND EVENING. WIND SPEEDS WILL BE BORDER-LINE FOR AN
ADVISORY FRIDAY...BUT THINK CLOUDS WILL LIMIT HIGHER SPEEDS FROM
MIXING TO THE GROUND. ANOTHER SURGE IN WINDS IS EXPECTED SATURDAY
BUT THE 85H JET IS WEAKER THAN FRIDAY. CONFIDENCE ON AREAL COVERAGE
FOR STRONG WINDS IS LOW TO ISSUE HEADLINES AT THIS TIME. HIGH
PRESSURE BUILDS IN FROM THE SOUTHWEST SATURDAY AFTERNOON TO RELAX
THE WINDS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 PM EST WEDNESDAY...
THE COOL DOWN LOOKS TO BE SHORT-LIVED AS UPPER HEIGHTS BEGIN TO
BUILD YET AGAIN ON SUNDAY WITH 850 TEMPS BOUNCING BACK TO +4C TO +8C
BY LATE IN THE DAY AND SURFACE TEMPS BACK SLIGHTLY ABOVE
CLIMO...REACHING UPPER 40S NW TO LOW 50S SE. CLOUDS BEGIN TO
INCREASE FROM LATE SUNDAY INTO MONDAY AS THE SURFACE RIDGE MOVES
OFF THE EAST COAST AND TAKES UP RESIDENCE OVER THE WESTERN
ATLANTIC. A COOL FRONT ASSOCIATED WITH A GREAT LAKES LOW WILL
APPROACH THE REGION BUT THEN BECOMES RATHER DIFFUSE AND POORLY
ORGANIZED INTO TUESDAY AS HEIGHTS BUILD OFF THE EAST COAST AND
ANOTHER WESTERN TROUGH BEGINS TO DEVELOP. WILL SEE GRADUAL UPSWING
IN TEMPS/POPS THROUGH THE MID- WEEK PERIOD AS SW FLOW ALOFT BRINGS
WARMTH/MOISTURE NORTHWARD. SHOULD SEE VERY MILD HIGHS IN THE 50S
AND 60S AND LOWS MAINLY IN THE 40S OR EVEN LOW 50S. THESE NUMBERS
ARE ROUGHLY 10 TO 15F ABOVE NORMAL AND WILL KEEP US ON TRACK FOR
WHAT COULD BE A RECORD- BREAKING WARM DECEMBER. THROUGH MID-MONTH
(DEC. 1-15) ALL 5 CLIMATE SITES ARE IN THE TOP 5 ALL-TIME AND
BLUEFIELD IN 1ST PLACE (SINCE 1959). COULD ALSO SEE MODERATE TO
POSSIBLY HEAVY RAINFALL DURING MUCH OF THIS PERIOD...UP TO AN INCH
OR MORE POSSIBLE...BUT FOCUS FOR HEAVIEST RAINS STILL APPEARS TO
BE FURTHER TO THE SOUTHWEST ALONG THE GULF COAST.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
AS OF 1240 PM EST THURSDAY...
A COLD FRONT WILL CONTINUE PROGRESSING EASTWARD ACROSS THE REGION
THIS AFTERNOON. LIGHT TO MODERATE RAIN WILL CONTINUE IN ADVANCE OF
IT...BUT THE BULK OF IT IS EXPECTED TO EXIT THE EASTERN PORTION OF
THE AREA WITHIN THE NEXT FEW HOURS. ADDITIONAL LIGHT RAIN SHOWERS
ARE EXPECTED BEHIND THE FRONT AS NORTHWEST UPSLOPE CONDITIONS
DEVELOP. MOST OF THESE WOULD BE OVER SOUTHEAST WEST
VIRGINIA...SOUTH INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA.
EXPECT IFR/MVFR CIGS AND VSBYS TO CONTINUE IN ADVANCE OF THE
FRONT. BEHIND THE FRONT...DRIER AIR WILL WORK ITS WAY INTO THE
AREA THIS EVENING LIMITING THE FOG AT THE SURFACE. IFR/MVFR CIGS
WILL CONTINUE TO BE POSSIBLE...ESPECIALLY ACROSS THE PREFERRED
UPSLOPE REGION IN THE WEST. COLDER AIR WILL ARRIVE
OVERNIGHT...ALLOWING FOR THE POTENTIAL OF A CHANGE FROM LIGHT RAIN
SHOWERS TO LIGHT SNOW SHOWERS IN THE FAR WEST. THESE WOULD
CONTINUE INTO FRIDAY. AFTER SUNRISE FRIDAY....VSBYS ARE EXPECTED
TO IMPROVE TO VFR WITH CIGS SLOWLY IMPROVING THROUGH MID-DAY.
SURFACE GUSTS WILL BE ON THE INCREASE FRIDAY MORNING WITH 850 MB
WINDS AROUND 40 KTS BY 18Z/1PM.
.EXTENDED AVIATION DISCUSSION...
GUSTY NORTHWEST WINDS FRIDAY INTO FRIDAY NIGHT ON THE BACKSIDE OF
THE DEPARTING SYSTEM WILL KEEP UPSLOPE IFR/MVFR CLOUDS AND
ISOLATED RAIN OR SNOW SHOWERS ACROSS THE MOUNTAINS...ESPECIALLY
PARTS OF SOUTHEAST WEST VIRGINIA INTO THE NORTHERN MOUNTAINS OF
NORTH CAROLINA. SNOW SHOWERS ALONG WITH MVFR CEILINGS ARE LIKELY
IN SOUTHEAST WEST VIRGINIA ON FRIDAY AND SATURDAY.
THE PRESSURE GRADIENT WILL SLACKEN SATURDAY NIGHT INTO SUNDAY AS
THE CENTER OF HIGH PRESSURE BUILDS INTO THE REGION. THIS WILL ALSO
BRING AN END TO UPSLOPE CLOUDS AND LIGHT PRECIPITATION. VFR
CONDITIONS ARE EXPECTED SUNDAY.
BY LATE SUNDAY NIGHT INTO MONDAY...THE NEXT COLD FRONT WILL BE ON
OUR WESTERN EDGES OF THE FORECAST AREA. LOOK FOR A RETURN OF MVFR
CLOUD COVER...STRONGER LOW LEVEL WINDS...AND PRECIPITATION WITH
THE APPROACH AND PASSAGE OF THIS FRONT.
MONDAY NIGHT INTO TUESDAY...THE FRONT CROSSES THE AREA WITH ITS
ASSOCIATED PRECIPITAITON AND SUB-VFR CIGS AND VSBYS.
&&
.HYDROLOGY...
AS OF 300 AM THURSDAY...
FORECAST RAINFALL AMOUNTS OF THREE QUARTERS TO 1.5 INCHES WILL
BRING RISES ON THE SMALLER CREEKS AND STREAMS LATER TODAY BUT
OVERALL THE THREAT OF FLOODING WILL BE LOW. STILL CANNOT RULE OUT
SOME HIGHER RAINFALL RATES THAT COULD BRING PONDING OF WATER OR
POOR DRAINAGE FLOODING TO URBAN AREAS...BUT THIS DOES NOT WARRANT
A FLOOD WATCH.
IMPACTS ON THE MAIN STEM RIVERS INTO FRIDAY TO SATURDAY SHOWS ONLY
SOUTH BOSTON REACHING ACTION STAGE WITH A FORECAST TO RISE TO 18.1
FEET...JUST UNDER A FOOT FROM FLOOD STAGE BY FRIDAY NIGHT.
ENSEMBLES ALSO KEEP THE THREAT OF RIVER FLOODING LOW WITH THE 18Z
GEFS SHOWING THE HIGHER PROBABILITY OF THE ENSEMBLES WITH A 30
PERCENT CHANCE THAT DANVILLE AND SOUTH BOSTON REACH FLOOD STAGE.
RIVER FORECAST CENTERS AND OUR OFFICE ARE FORECASTING LOWER.
&&
.EQUIPMENT...
AS OF 1100 AM EST THURSDAY...
NOAA WEATHER RADIO...
THE NOAA WEATHER RADIO AT RICHLANDS...WZ-2543...REMAINS DOWN.
TECHNICIANS ARE EXPECTED TO WORK ON THIS TODAY.
ASOS...
A COMMUNICATION OUTAGE HAS LIMITED THE DISTRIBUTION OF THE
OBSERVATION FROM THE BLUEFIELD AUTOMATED SURFACE OBSERVATION
SYSTEM. THERE IS NO ESTIMATE FOR WHEN THIS OUTAGE WILL BE
REPAIRED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/WP
NEAR TERM...DS/WP
SHORT TERM...RCS
LONG TERM...PC
AVIATION...DS
HYDROLOGY...PC/WP
EQUIPMENT...PM/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1123 AM EST THU DEC 17 2015
.SYNOPSIS...
A COLD FRONT CROSSES THE AREA TODAY WITH WIDESPREAD RAINFALL. THIS
FRONT WILL BE ALONG THE COAST BY FRIDAY MORNING. A STRONG UPPER
LEVEL TROUGH WILL BRING US BACK COLDER TEMPERATURES INTO THE
WEEKEND...BUT THIS WILL BE SHORT-LIVED. ANOTHER COLD FRONT WILL
MAKE ITS WAY TOWARDS THE REGION AND IMPACT THE AREA MONDAY INTO
TUESDAY OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM EST THURSDAY...
WIDESPREAD LIGHT TO MODERATE RAIN WAS STILL OCCURRING ACROSS THE
REGION AS A COLD FRONT ENTERS THE FAR WESTERN SECTION OF THE
FORECAST AREA. PRECIPITATION WILL CONTINUE IN ADVANCE OF THIS
FRONT HEADING INTO THE AFTERNOON. DURING THE AFTERNOON HOURS...THE
FRONT WILL CROSS THE REGION...AND AS A RESULT...THE ASSOCIATION
PRECIPITATION SHIELD WILL ALSO PROGRESS EASTWARD WITH
IT...BRINGING DECREASING COVERAGE OF PRECIPITATION TO WESTERN
PARTS OF THE AREA FIRST. LATER IN THE AFTERNOON...PRECIPITATION IS
EXPECTED TO INCREASE AGAIN ACROSS THE PREFERRED UPSLOPE AREAS OF
SOUTHEAST WEST VIRGINIA...SOUTH INTO THE NORTHERN MOUNTAINS OF
NORTH CAROLINA AS NORTHWEST FLOW BEHIND THE FRONT STARTS TO
INCREASE.
AS OF 622 AM EST THURSDAY...
LATEST RADAR SHOWING BROAD AREA OF RAIN OVER MOST OF THE FORECAST
AREA. THE 11Z RAP MESOANALYSIS SHOWED BEST UPPER DIVERGENCE NOW
OVER SE WV EAST TO LYH-RIC. THERE IS SOME WEAKENING TO THE SOUTH
TO THE RAIN. AT THIS TIME...HRRR DEPICTING THINGS THE BEST. GIVEN
THIS...WILL STILL SEE GREATEST CONCENTRATION OF RAIN THROUGH EARLY
AFTERNOON...THEN SHOULD SEE A DRYING TREND IN THE WEST...AND
FASTER MOVING OUT THIS EVENING OF THE RAIN...SO SPED UP THE DRYING
WITH THIS UPDATE.
PREVIOUS DISCUSSION FROM EARLY THIS MORNING...
FRONTAL BOUNDARY EARLY THIS MORNING STRETCHES FROM A 990MB LOW
OVER THE NRN TIP OF LAKE SUPERIOR SOUTHWARD INTO CENTRAL KY/MID
TN...WITH A WEAK LOW PRESSURE WAVE OVER ERN KY ALONG A WARM
FRONTAL BOUNDARY. RADAR INDICATING LIGHT TO AT TIMES MODERATE RAIN
MOVING NNE ACROSS THE NC INTO SOUTHSIDE VA AND OVER WV/FAR SW VA.
MODELS IN AGREEMENT ON THE SYNOPTICS...THOUGH SOME DIFFERENCES ON
PLACEMENT OF HIGHER QPF...WITH THE NAM A LITTLE WEST OF THE
GFS/ECMWF.
EARLY THIS MORNING THE BEST UPPER DIVERGENCE WITH THE 140KT 300MB
JET WAS OVER ERN TN INTO THE NC PIEDMONT. THE GFS PICKED UP ON THIS
UPPER PATTERN WELL AND GENERALLY FOLLOWED ITS SOLUTION BLENDED WITH
THE ECMWF. THE QPF WILL BE HIGHEST ALONG AND EAST OF THE BLUE RIDGE
WHICH WE HAVE BEEN ADVERTISING THE PAST 2 DAYS. EXPECT THE RAIN TO
BE HEAVY AT TIMES TODAY IN ASSOCIATION WITH A STRONGER LOW LVL JET
MOVING IN FROM UPSTATE SC AT 7AM INTO THE VA/NC PIEDMONT BY NOON.
STRONG PRESSURE FALLS OVER THE MID ATLANTIC THIS AFTERNOON INDICATES
POTENTIAL FOR THAN ONE WAVE OF LOW PRESSURE TO FORM ALONG THE FRONT.
DIFFICULT TO SEE HOW SLOW AND HOW FAR WEST THE RAIN WILL LINGER INTO
THE PIEDMONT INTO EARLY EVENING...SO KEPT SOME HIGHER POPS EAST OF A
LYNCHBURG TO MARTINSVILLE LINE...THEN TAPER TO CHANCE BY MIDNIGHT.
EXPECT CATEGORICAL POPS AREA WIDE THROUGH MOST OF THE DAY WITH
DEEPER MOISTURE POISED TO MOVE OUT OF THE MOUNTAINS BY DUSK...THOUGH
LOW LVL MOISTURE REMAIN ACROSS THE WESTERN SLOPES THROUGH TONIGHT.
ALTHOUGH THE STORM PREDICTION CENTER HAS A GENERAL THUNDER RISK INTO
THE PIEDMONT...APPEARS THAT INSTABILITY IS NIL...AND MAINLY HAVING
STRONG JET DYNAMICS TO AID IN LIFT...SO ANY THUNDER WOULD BE PRESSED
FURTHER EAST TOWARD THE COAST WHERE THERE IS A BETTER ENVIRONMENT
FOR THAT THIS AFTERNOON. STILL SOME STRONGER CONVECTIVE ELEMENTS
COULD MOVE ACROSS THE PIEDMONT OF VA/NC THROUGH MID AFTERNOON.
RAINFALL AMOUNTS FROM EARLY THIS MORNING THROUGH THURSDAY EVENING
WILL RANGE FROM 1 TO 1.25 ALONG/EAST OF THE BLUE RIDGE WITH LOCALLY
HIGHER AMOUNTS POSSIBLE. WEST...EXPECT THREE QUARTERS TO AN INCH.
SEE HYDRO SECTION BELOW FOR COMMENTS ABOUT IMPACTS ON
STREAMS/RIVERS.
TEMPERATURES THIS MORNING WILL STAY STEADY OR SLOWLY RISE BUT WITH
RAINFALL MOVING IN...GOING TO SEE HIGHS HELD IN CHECK WITH LOWER TO
MID 50S MOST AREAS...AND UP TO 60 IN SOUTHSIDE VA INTO NW NC
PIEDMONT. STILL THIS ABOUT 5-10 DEGREES ABOVE NORMAL.
TONIGHT...AS THE 8H FRONT MOVES EAST...STRONGER COLD ADVECTION
SLIDES INTO THE MOUNTAINS. MOISTURE DEPTH OVERALL IS SUFFICIENT FOR
SOME LIGHT RAIN CHANGING TO SNOW SHOWERS AFTER MIDNIGHT...THOUGH
ACCUMULATION THROUGH DAWN IS GOING TO BE LITTLE/NONE. TEMPS MAY
STAY ELEVATED ACROSS THE PIEDMONT UNTIL A LATE DROP. AS SUCH HAVE
LOWS RANGING FROM THE LOWER 30S ACROSS THE WESTERN SLOPES TO MID
30S NEW RIVER VALLEY/BLUE RIDGE...UPPER 30S TO LOWER 40S ROANOKE
TO LYNCHBURG...AND FOOTHILLS...WITH MID TO UPPER 40S FROM
FARMVILLE TO YADKINVILLE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 249 AM EST THURSDAY...
A COLD FRONT WILL MOVE OFF THE EAST COAST FRIDAY SENDING
TEMPERATURES DOWN INTO THE 30S AND 40S FRIDAY AFTERNOON. SINCE THE
WEATHER HAS BEEN VERY WARM FOR THE LAST COUPLE OF WEEK...THIS DROP
IN TEMPERATURES WILL SEEM LIKE AN ARCTIC AIRMASS...BUT IN REALITY
TEMPERATURES WILL BE SEASONAL FOR ONCE. THOSE WHO ARE NOT FANS OF
COLD WEATHER WILL BE HAPPY WHEN WARMER THAN NORMAL TEMPERATURES
RETURN ON SUNDAY.
THROUGH THE DAY FRIDAY...85H TEMPERATURES WILL CONTINUE TO FALL AS
COLD AIR RUSHES IN ON NORTHWEST FLOW. HIGH TEMPERATURES FRIDAY WILL
LIKELY OCCUR DURING THE MORNING FOR THE MOUNTAINS AND EARLY
AFTERNOON IN THE PIEDMONT. DESPITE MORNING TEMPERATURES BEING IN THE
UPPER 30S TO LOWER 40S...WILL KEEP ANY MOUNTAIN PRECIPITATION AS
SNOW AS LOW LEVEL WARM BOUNDARY LAYER WILL BE SHALLOW. SOME SNOW
ACCUMULATIONS ARE POSSIBLE DURING THE DAY FRIDAY FOR THE HIGHER
ELEVATIONS OF SE WV ABOVE 3000 FEET. BELOW 3000 FEET...GROUND
TEMPERATURES SHOULD REMAIN WARM THROUGH THE DAY TO KEEP ANY
ACCUMULATION TO A DUSTING OR LESS ON ELEVATED SURFACES AND ONLY
ALONG WESTERN SLOPES. AROUND 400 PM INTO THE NIGHT...ACCUMULATIONS
CHANCES INCREASE ALONG HIGHER ELEVATIONS AND WESTERN SLOPES FROM SE
WV...MOUNTAIN EMPIRE AND GRAYSON HIGHLAND OF SW VA AND THE NC HIGH
COUNTY. THIS UPSLOPE EVENT IS LACKING MOISTURE AND ACCUMULATIONS MAY
AMOUNT TO AN INCH OR SO FROM DRY SNOW. THE UPPER LEVEL TROUGH PIVOTS
TO THE MID ATLANTIC COAST SATURDAY MORNING...ENDING THIS BRIEF
UPSLOPE EVENT. PRESSURE RISES BEHIND THE FRONT FRIDAY AND FRIDAY
NIGHT WILL ALSO BRING BREEZY AND GUSTY WINDS TO THE FORECAST AREA.
THIS WIND MAY BE ENOUGH TO PUSH FLURRIES TO THE BLUE RIDGE FRIDAY
AFTERNOON AND EVENING. WIND SPEEDS WILL BE BORDER-LINE FOR AN
ADVISORY FRIDAY...BUT THINK CLOUDS WILL LIMIT HIGHER SPEEDS FROM
MIXING TO THE GROUND. ANOTHER SURGE IN WINDS IS EXPECTED SATURDAY
BUT THE 85H JET IS WEAKER THAN FRIDAY. CONFIDENCE ON AREAL COVERAGE
FOR STRONG WINDS IS LOW TO ISSUE HEADLINES AT THIS TIME. HIGH
PRESSURE BUILDS IN FROM THE SOUTHWEST SATURDAY AFTERNOON TO RELAX
THE WINDS.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 PM EST WEDNESDAY...
THE COOL DOWN LOOKS TO BE SHORT-LIVED AS UPPER HEIGHTS BEGIN TO
BUILD YET AGAIN ON SUNDAY WITH 850 TEMPS BOUNCING BACK TO +4C TO +8C
BY LATE IN THE DAY AND SURFACE TEMPS BACK SLIGHTLY ABOVE
CLIMO...REACHING UPPER 40S NW TO LOW 50S SE. CLOUDS BEGIN TO
INCREASE FROM LATE SUNDAY INTO MONDAY AS THE SURFACE RIDGE MOVES
OFF THE EAST COAST AND TAKES UP RESIDENCE OVER THE WESTERN
ATLANTIC. A COOL FRONT ASSOCIATED WITH A GREAT LAKES LOW WILL
APPROACH THE REGION BUT THEN BECOMES RATHER DIFFUSE AND POORLY
ORGANIZED INTO TUESDAY AS HEIGHTS BUILD OFF THE EAST COAST AND
ANOTHER WESTERN TROUGH BEGINS TO DEVELOP. WILL SEE GRADUAL UPSWING
IN TEMPS/POPS THROUGH THE MID- WEEK PERIOD AS SW FLOW ALOFT BRINGS
WARMTH/MOISTURE NORTHWARD. SHOULD SEE VERY MILD HIGHS IN THE 50S
AND 60S AND LOWS MAINLY IN THE 40S OR EVEN LOW 50S. THESE NUMBERS
ARE ROUGHLY 10 TO 15F ABOVE NORMAL AND WILL KEEP US ON TRACK FOR
WHAT COULD BE A RECORD- BREAKING WARM DECEMBER. THROUGH MID-MONTH
(DEC. 1-15) ALL 5 CLIMATE SITES ARE IN THE TOP 5 ALL-TIME AND
BLUEFIELD IN 1ST PLACE (SINCE 1959). COULD ALSO SEE MODERATE TO
POSSIBLY HEAVY RAINFALL DURING MUCH OF THIS PERIOD...UP TO AN INCH
OR MORE POSSIBLE...BUT FOCUS FOR HEAVIEST RAINS STILL APPEARS TO
BE FURTHER TO THE SOUTHWEST ALONG THE GULF COAST.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
AS OF 640 AM EST THURSDAY...
CIGS THIS MORNING VARY FROM IFR TO VFR WITH LIGHT TO MODERATE RAIN
MOVING ACROSS. MAJORITY OF THE DAY WILL SEE RAIN WITH MVFR OR
LOWER CIGS/VSBYS AT ALL SITES. HIGH RES MODELS BRING AN END TO THE
RAIN IN THE LWB/BLF AREA BY 20Z...BCB/ROA BETWEEN 21-00Z...AND
EAST OF LYH/DAN BY 00-01Z. WINDS WILL SHIFT FROM VARIABLE TO SOUTH
THIS MORNING THEN AS THE FRONT MOVES ACROSS TO THE WNW. WINDS WILL
STAY AROUND 10KTS OR LESS. A STRONG LOW LVL JET MOVES ACROSS THIS
MORNING MAINLY EAST OF THE BLUE RIDGE SO LOW LVL WIND SHEAR WAS
KEPT IN LYH/DAN/BCB AROUND 15-19Z.
ONCE THE WINDS SHIFT AROUND TO THE WEST ANTICIPATE CIGS TO LIFT TO
VFR THIS EVENING ROA/LYH/DAN AND BY 06Z AT BCB...WHILE BLF/LWB
KEEP MVFR/IFR CIGS AROUND 1KFT THROUGH THE NIGHT. ATTM...LEFT OUT
SNOW SHOWERS OR DRIZZLE AS MOISTURE AT LWB/BLF LOOKS LACKING.
.EXTENDED AVIATION DISCUSSION...
GUSTY NORTHWEST WINDS FRIDAY INTO FRIDAY NIGHT ON THE BACKSIDE OF
THE DEPARTING SYSTEM WILL KEEP UPSLOPE IFR/MVFR CLOUDS AND
ISOLATED RAIN OR SNOW SHOWERS ACROSS THE MOUNTAINS...ESPECIALLY
PARTS OF SOUTHEAST WEST VIRGINIA INTO THE NORTHERN MOUNTAINS OF
NORTH CAROLINA. SNOW SHOWERS ALONG WITH MVFR CEILINGS ARE LIKELY
IN SOUTHEAST WEST VIRGINIA ON FRIDAY AND SATURDAY.
THE PRESSURE GRADIENT WILL SLACKEN SATURDAY NIGHT INTO SUNDAY AS
THE CENTER OF HIGH PRESSURE BUILDS INTO THE REGION. THIS WILL ALSO
BRING AN END TO UPSLOPE CLOUDS AND LIGHT PRECIPITATION. VFR
CONDITIONS ARE EXPECTED SUNDAY.
BY LATE SUNDAY NIGHT INTO MONDAY...THE NEXT COLD FRONT WILL BE ON
OUR WESTERN EDGES OF THE FORECAST AREA. LOOK FOR A RETURN OF MVFR
CLOUD COVER...STRONGER LOW LEVEL WINDS...AND PRECIPITATION WITH
THE APPROACH AND PASSAGE OF THIS FRONT.
&&
.HYDROLOGY...
AS OF 300 AM THURSDAY...
FORECAST RAINFALL AMOUNTS OF THREE QUARTERS TO 1.5 INCHES WILL
BRING RISES ON THE SMALLER CREEKS AND STREAMS LATER TODAY BUT
OVERALL THE THREAT OF FLOODING WILL BE LOW. STILL CANNOT RULE OUT
SOME HIGHER RAINFALL RATES THAT COULD BRING PONDING OF WATER OR
POOR DRAINAGE FLOODING TO URBAN AREAS...BUT THIS DOES NOT WARRANT
A FLOOD WATCH.
IMPACTS ON THE MAIN STEM RIVERS INTO FRIDAY TO SATURDAY SHOWS ONLY
SOUTH BOSTON REACHING ACTION STAGE WITH A FORECAST TO RISE TO 18.1
FEET...JUST UNDER A FOOT FROM FLOOD STAGE BY FRIDAY NIGHT.
ENSEMBLES ALSO KEEP THE THREAT OF RIVER FLOODING LOW WITH THE 18Z
GEFS SHOWING THE HIGHER PROBABILITY OF THE ENSEMBLES WITH A 30
PERCENT CHANCE THAT DANVILLE AND SOUTH BOSTON REACH FLOOD STAGE.
RIVER FORECAST CENTERS AND OUR OFFICE ARE FORECASTING LOWER.
&&
.EQUIPMENT...
AS OF 1100 AM EST THURSDAY...
NOAA WEATHER RADIO...
THE NOAA WEATHER RADIO AT RICHLANDS...WZ-2543...REMAINS DOWN.
TECHNICIANS ARE EXPECTED TO WORK ON THIS TODAY.
ASOS...
A COMMUNICATION OUTAGE HAS LIMITED THE DISTRIBUTION OF THE
OBSERVATION FROM THE BLUEFIELD AUTOMATED SURFACE OBSERVATION
SYSTEM. THERE IS NO ESTIMATE FOR WHEN THIS OUTAGE WILL BE
REPAIRED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/WP
NEAR TERM...DS/WP
SHORT TERM...RCS
LONG TERM...PC
AVIATION...AMS/DS/WP
HYDROLOGY...PC/WP
EQUIPMENT...PM/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 AM CST THU DEC 17 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 331 AM CST THU DEC 17 2015
FOCUSED ON WIND FORECASTS THROUGH FRIDAY WITH STEEP BOUNDARY LAYER
LAPSE RATES...AND CLOUDS AND LIGHT SNOW CHANCES ALSO COME WITH
THAT.
GOES WATER VAPOR SHOWING NUMEROUS OVERHEAD AND UPSTREAM WEAK
SHORTWAVE TROUGHS...WITH THE STRONGEST CLEARLY VISIBLE OVER
NORTHERN SASKATCHEWAN /WHICH ARRIVES FRIDAY MID-DAY/. REGIONAL
RADARS SHOWING BATCHES OF FLURRIES ACROSS THE NORTHERN STATES IN
CYCLONIC FLOW WITH 3SM+ -SN. BEST ECHO IS IN ERN ND WHICH FITS
WELL WITH RAP ANALYSIS OF LOW-LEVEL COLD ADVECTION AREA. IR
IMAGERY DEPICTING STRATUS OVER MUCH OF THE REGION HOWEVER A
CLEARING LINE WAS WORKING EAST THROUGH THE DAKOTAS AT 09Z WHICH
DOES HAVE MY INTEREST.
NORTHWEST FLOW WILL BRING A NUMBER OF WEAKER SHORTWAVE TROUGHS
THROUGH THE REGION ALONG WITH WAVES OF COLD AIR ADVECTION /CAA/.
THE CAA WAVES WILL STEEPEN LAPSE RATES AND ALLOW MIXING TO ENHANCE
WINDS AND PRECIPITATION CHANCES /FLURRIES/ THROUGH FRIDAY BEFORE
RIDGE BUILDING BEGINS SATURDAY. A COLD ADVECTION PUSH ARRIVES FROM
THE ERN DAKOTAS THIS AFTERNOON WHICH WILL ENHANCE WINDS
AGAIN...ALTHOUGH NOT AS STRONG AS WEDNESDAY GUSTS...BUT 30 MPH IS
POSSIBLE. HAVE ADDED FLURRIES SOUTH TO AROUND I-90 TODAY. THE
SNOW SQUALL PARAMETER IN THE NAM IS VERY /OVERLY?/ EXCITED NORTH
OF I-90 THIS AFTERNOON WITH STEEP LAPSE RATES. BUT THE NAM DOESNT
PRODUCE MEASURABLE PRECIPITATION. RAP FORECASTS HAVE BEEN LESS
THAN ENTHUSED. FORECAST SPLITS THE DIFFERENCE WITH FLURRIES.
CONSENSUS MODEL FORECAST IS TO POSSIBLY TRY TO BREAK SOME SUN
INTO THE SOUTHERN FORECAST AREA TODAY...POSSIBLY THE CLEARING LINE
FROM THE DAKOTAS. WOULD THINK WITH LAPSE RATES AS STEEP IN THE
BOUNDARY LAYER...BREAKS WOULD FILL IN WITH BKN SKIES. HAVE COME
DOWN A BIT IN SKY COVER...BUT STILL IN THE CLOUDY/MOSTLY CLOUDY
RANGE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 331 AM CST THU DEC 17 2015
WAVES OF COLD ADVECTION CONTINUE WITH STEEPER LAPSE RATES INTO
FRIDAY. SASKA SHORTWAVE TROUGH ARRIVES FRIDAY TO ENHANCE LIFT AND
PROVIDE AGAIN A BURST OF FLURRIES...AND DEEPER MIXING. WIND GUSTS
COULD BE IN THE 30 TO 35 MPH RANGE IF REALIZED...AND THE FORECAST
WINDS WERE BUMPED UP SOME. HAVE CONTINUED THE FLURRIES THROUGH
THAT PERIOD..BUT BEST SIGNAL /LOW-LEVEL LAPSE RATES AND WEAK QG
FORCING IN THAT LAYER/ FOR MEASURABLE SNOW IS THROUGH IA AND SWRN
WI. AGAIN...17.00Z NAM MOST AGGRESSIVE ON THIS...BUT 17.06Z NAM
HAS STEPPED BACK FROM MORE AGGRESSIVE PARAMETER SPACE.
SUNDAY INTO MONDAY...
BETTER GROUPING IN THE DETERMINISTIC SUITE ON A MODERATE OPEN
SHORTWAVE TROUGH MOVING THROUGH THE REGION. WARM ADVECTION AND
MOISTURE TRANSPORT CONVERGENT SIGNALS INCREASE SUNDAY...MAINLY
INTO IL/WI WITH PRECIPITATION LOOKING LIKELY THERE /TO OUR EAST/.
17.00Z GFS SOUNDINGS SHOW ANOTHER 2KM SATURATED LAYER WITH NO ICE
INTRODUCTION...AND TEMPERATURES SUPPORTING MAINLY RAIN. FREEZING
RAIN MAY BE POSSIBLE FOR A PERIOD SHOULD THE COLD AIR NOT SCOUR
OUT IN THE WARM ADVECTION EARLY SUNDAY. COLD FRONT WILL MOVE
THROUGH SUNDAY NIGHT WITH A CHANGE OVER TO ALL SNOW. IF THIS WAVE
WERE MORE OF A CLOSED LOW...THERE WOULD BE CONCERN FOR DEFORMATION
SNOW ON THE WEST SIDE OF THE CYCLONE /MN...IA/ DUE TO
PRECIPITATION RATE COOLING...BUT THAT ISNT THE CASE. OVERALL WIND
MAY BE THE MOST IMPACT AGAIN FROM THIS CYCLONE...FORECAST WAS
BOOSTED ABOVE CONSENSUS...BUT LIKELY NOT ENOUGH FOR POST-COLD
FRONT WINDS MONDAY WHICH LOOK LIKE THEY COULD GUST OVER 30 MPH.
WILL TREND THE WIND FORECAST IN THE NEXT DAYS AS NEEDED.
THE REMAINDER OF THE WEEK LOOKS ACTIVE WITH LITTLE IN THE WAY OF
PREDICTABILITY. THERE COULD BE HOLIDAY WEATHER BUT TOO EARLY TO
TELL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1100 AM CST THU DEC 17 2015
LOW PRESSURE WAS PULLING NORTHEAST INTO EASTERN CANADA...WHILE AN
UPPER LEVEL SHORTWAVE TROUGH WAS DROPPING SOUTHEAST TOWARD THE
NORTHERN PLAINS. EXTENSIVE CLOUD SHIELD ASSOCIATED WITH BOTH
FEATURES...MOSTLY VFR/MVFR HOVERING NEAR 3 KFT. THAT
SAID...SATELLITE IMAGERY/SFC OBS POINT TO A CLEAR SLOT BETWEEN THE
TWO CLOUD MASSES...IN A REGION OF SINKING AIR. MESO MODELS SUGGEST
THAT THIS WILL SLIDE ACROSS THE LOCAL AREA THIS AFTERNOON/EARLY
EVENING...AND COULD BRING A 3-6 HOUR WINDOW OF SCT SKIES. LOW LEVEL
LAPSE RATES HINT THAT SCT-BKN CU COULD DEVELOP IN THE CLEAR
SLOT...BUT UNSURE WHETHER THIS UPWARD MOTION WOULD OVERCOME THE
SUBSIDENCE. WILL ADD SOME SCT INTO THE FORECAST.
TIGHT PRESSURE GRADIENT LOOKS TO KEEP BLUSTERY WEST WINDS UP THROUGH
TODAY/TONIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...RIECK