Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/26/14
AREA FORECAST DISCUSSION
NWS ALBANY NY
927 PM EST TUE NOV 25 2014
.SYNOPSIS...
A COASTAL LOW WILL BRING A WIDESPREAD SNOWFALL TO THE AREA THAT WILL
SIGNIFICANTLY IMPACT HOLIDAY TRAVEL WEDNESDAY AND WEDNESDAY NIGHT.
HEAVY SNOWFALL IS EXPECTED ACROSS WESTERN NEW ENGLAND AND MUCH OF
EASTERN NEW YORK WITH THE HEAVIEST SNOW OCCURRING THE AFTERNOON INTO
THE EVENING. THE SNOW IS EXPECTED TO TAPER LATE WEDNESDAY
NIGHT...WITH SOME LINGERING SNOW SHOWERS ACROSS THE AREA FOR
THANKSGIVING DAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
COLDER AIR FILTERS IN HELPING TO SET THE STAGE FOR A WIDESPREAD
SNOWFALL. SATELLITE IMAGERY SHOWING MID AND HIGH CLOUDS BUILDING
NORTH AND NORTHEAST FROM THE SOUTHEASTERN U.S. AND STRATOCUMULUS
EDGING EAST FROM THE GREAT LAKES. MOST AREAS SHOULD BE CLOUDY
BEFORE MIDNIGHT...WHICH COULD LIMIT THE COOLING ACROSS THE REGION.
ALTHOUGH...STILL SOME COLD ADVECTION OCCURRING AS WEST LOW LEVEL
WIND FLOW AND COOLING BOUNDARY LAYER TEMPERATURES SPREAD ACROSS
THE REGION THROUGH THE NIGHT. SOME MINOR ADJUSTMENTS TO
TEMPERATURES THROUGH TONIGHT.
WILL BE TRACKING THE NORTHWESTERN EDGE OF THE UPPER DEFORMATION
ZONE DEVELOPING IN THE SOUTHEASTERN U.S. TO GET A FEEL FOR THE
NORTHWESTERN EXTENT OF THE HEAVIEST SNOW AS THE UPPER DEFORMATION
TRACKS TOWARD THE NORTHEASTERN U.S. INTERESTING WATER VAPOR
IMAGERY SHOWS 2 CLOSED UPPER VORTICITY CENTERS LINED UP FROM JUST
NORTH OF THE GREAT LAKES THROUGH EASTERN CANADA...SO WILL THE
EXTENSIVE LINE OF SHEAR ASSOCIATED WITH STRONG UPPER JET ENERGY
ALONG THE EASTERN U.S. HELP THE UPPER DEFORMATION IN THE UPCOMING
STORM TO BECOME A CLOSED VORTICITY CENTER LIKE THE ONES
DOWNSTREAM? IF SO...PERHAPS THE UPCOMING STORM COULD HAVE MORE
UPPER DYNAMICS AND BUILD THE HEAVIER PRECIPITATION FURTHER NORTH.
THAT WOULD BE A BIT DIFFERENT THAN THE OPEN WAVE ALL THE GUIDANCE
SUGGESTS ASSOCIATED WITH THE UPCOMING STORM...BUT JUST HAVE TO
WATCH TRENDS TO REFINE THE FORECAST THROUGH THE NIGHT. LOWS IN
THE 20S NORTH TO LOWER TO MID 30S CENTRAL AND SOUTH.
BASED ON THE LATEST RADAR AND SATELLITE TRENDS AND LATEST HRRR AND
LOCAL WRF...THE ONSET OF THE SNOW COULD BE MORE AROUND SUNRISE
RATHER THAN BEFORE SUNRISE IN SOUTHERN AND CENTRAL AREAS. CLOUDS
WILL ALSO THICKEN AND LOWER TONIGHT. SO...LIGHT PRECIPITATION
SHOULD BEGIN TO MOVE INTO THE CENTRAL AND SOUTHEASTERN
CATSKILLS...MID HUDSON VALLEY...LITCHFIELD COUNTY AND SOUTHERN
BERKSHIRES AROUND SUNRISE WITH SOME MIXED POSSIBLE OF SNOW...RAIN
AND SLEET TO START. SOME MINOR ADJUSTMENTS TO THE FORECASTED
ONSET LATER TONIGHT AND TOMORROW MORNING.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES REMAIN IN
EFFECT.
THE HIGHEST SNOWFALL AMOUNTS ARE EXPECTED ACROSS THE WESTERN NEW
ENGLAND...THE TACONICS...THE HIGHER TERRAIN OF THE CENTRAL AND
SOUTHEASTERN CATSKILLS AND PORTIONS OF THE MID HUDSON VALLEY.
AMOUNTS WILL DECREASE AS YOU HEAD NORTHWEST ACROSS THE FORECAST AREA
AWAY FROM THE COASTAL LOW WITH THE GRADIENT BETWEEN WARNING LEVEL
AND ADVISORY LEVEL SNOWFALL EXPECTED TO OCCUR IN THE VICINITY OF THE
SCHOHARIE VALLEY...CAPITAL DISTRICT AND LAKE GEORGE SARATOGA AREA.
THIS IS WHY THE WINTER STORM WATCH WAS IN EFFECT AS LONG AS IT WAS.
MILLER TYPE A COASTAL LOW TAPPING GULF MOISTURE. SOUTHERN STREAM
ENERGY IS INITIATING THE DEVELOPING OF A LOW ALONG THE GULF
COASTAL ALONG A STALLED FRONTAL BOUNDARY. THE LOW WILL TRACK
NORTHEASTWARD AND DEEPEN. THE GUIDANCE HAS COME INTO GOOD
AGREEMENT ON THE TRACK...POSITION AND STRENGTH OF THE STORM
PASSING THE LOW JUST SOUTH OF CAPE COD WEDNESDAY EVENING. THE
DIFFERENCES ARE OCCURRING IN THE QPF. GUIDANCE ALSO CONTINUES TO
INDICATE BANDING WILL OCCUR ESPECIALLY FOR AREAS TO THE SOUTH AND
EAST OF THE CAPITAL DISTRICT HENCE THE HIGHER SNOWFALL FORECAST.
SNOWFALL RATES OF UP TO AN INCH AN HOUR ARE EXPECTED EXPECTED AT
TIMES ACROSS PORTIONS OF THE WARNING AREA WITH AROUND 2 INCHES AN
HOUR POSSIBLE SOUTH AND EAST OF THE CAPITAL DISTRICT WHERE BANDING
IS MORE LIKELY.
SNOW RATIO WILL BE LOWER ACROSS THE MID HUDSON AND NORTHWESTERN
CONNECTICUT AND WITH THE HIGHER TOTALS AND STRONGER WINDS SOME
ISOLATED POWER OUTAGES CAN BE RULED OUT.
APPROACHING NORTHERN STREAM ENERGY DOES NOT PHASE WITH THE
SOUTHERN STREAM KEEPING STORM PROGRESSIVE BUT WILL BRING CHANCES
FOR SNOW SHOWERS TO THE REGION FOR THANKSGIVING DAY AND NIGHT
ESPECIALLY ACROSS THE HIGHER TERRAIN.
LITTLE RECOVERY IN TEMPERATURES WEDNESDAY UPPER 20S TO MID 30S.
MUCH COLDER AIR WILL NOT BE DRAWN INTO THE REGION UNDER AFTER THE
NORTHERN STREAM ENERGY MOVES OFF TO THE EAST.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE LONG TERM PERIOD WILL BE CHARACTERIZED BY PERIODS OF UNSETTLED
WEATHER...AS A SERIES OF FAST-MOVING SYSTEMS IMPACT THE REGION.
AT THE START OF THE LONG TERM PERIOD...IN THE WAKE OF THE COASTAL
STORM THAT IMPACTED THE REGION IN THE SHORT TERM PERIOD...THE
FORECAST AREA WILL BE UNDERNEATH A NORTHWEST FLOW REGIME THAT WILL
GRADUALLY BE DEAMPLIFYING HEADING INTO THE WEEKEND. BY THE
WEEKEND...THE FLOW WILL BECOME QUASI-ZONAL...ALLOWING FOR FAST
PIECES OF NORTHERN STREAM ENERGY TO MOVE THROUGH IT...IN WHICH THE
TIMING AND IMPACTS OF THESE FEATURES COULD CHANGE OVER THE NEXT FEW
DAYS AS MEDIUM-RANGE GUIDANCE OFTEN STRUGGLES HANDLING FAST ZONAL
FLOW. THE FIRST OF THESE PIECES OF ENERGY WILL AFFECT MAINLY AREAS
NORTH AND WEST OF THE CAPITAL REGION THURSDAY NIGHT...AS AN
UPPER-LEVEL SHORTWAVE RACES THROUGH THE NORTHWEST FLOW PROVIDING A
PERIOD OF SCATTERED LIGHT SNOW SHOWERS. ACCUMULATIONS WITH THIS
FEATURE WILL BE LIGHT...ON THE ORDER OF AN INCH OR TWO ACROSS
PORTIONS OF THE SOUTHERN ADIRONDACKS...AND A DUSTING TO PERHAPS AN
INCH ACROSS PORTIONS OF THE MOHAWK VALLEY AND LAKE GEORGE/SARATOGA
REGION.
MUCH OF THE REGION LOOKS TO BE DRY DURING THE DAY FRIDAY...EXCEPT
FOR SOME SCATTERED LAKE EFFECT SNOW SHOWERS THAT MAY SKIRT PORTIONS
OF HERKIMER COUNTY DOWNWIND OF LAKE ONTARIO. THE NEXT SYSTEM LOOKS
TO IMPACT THE REGION FOR MUCH OF THE WEEKEND AS AN AREA OF LOW
PRESSURE TRACKS NORTHEAST FROM THE CENTRAL PLAINS TO THE GREAT
LAKES. OUT AHEAD OF THIS LOW PRESSURE SYSTEM...WARM AIR ADVECTION
PRECIP AHEAD OF AN APPROACHING WARM FRONT MAY ALLOW FOR SCATTERED
RAIN/SNOW SHOWERS SATURDAY INTO SATURDAY NIGHT. NOT MUCH
MOISTURE/DYNAMICS WILL BE PRESENT WITH THIS BOUNDARY AS THE LOW
PRESSURE CENTER WILL BE LIFTING FAR NORTH AND WEST OF THE REGION.
DURING THE DAY SUNDAY...THE WARM FRONT SHOULD LIFT NORTH ACROSS THE
REGION...USHERING IN ANOTHER SHORT PERIOD OF MILD WEATHER WITH
SCATTERED RAIN/SNOW SHOWERS. HIGH PRESSURE LOOKS TO BUILD ACROSS THE
REGION FOR THE START OF NEXT WEEK RESULTING IN A PERIOD OF DRY
WEATHER INTO THE MIDDLE OF NEXT WEEK.
HIGH TEMPERATURES THROUGHOUT THE LONG TERM PERIOD WILL GENERALLY
RANGE FROM THE UPPER 20S TO UPPER 30S...EXCEPT ON SUNDAY WHERE HIGHS
WILL RANGE FROM THE UPPER 30S TO NEAR 50 IN VALLEY AREAS AND LOW 30S
TO MID 40S MONDAY. LOW TEMPERATURES WILL GENERALLY RANGE FROM THE
MID TEENS TO LOW 20S EXCEPT FOR UPPER 20S TO MID 30S SATURDAY AND
SUNDAY NIGHTS.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE EVENING HOURS. MID AND
HIGH LEVEL CLOUDS WILL CONTINUE TO INCREASE OVER THE AREA FROM THE
SOUTH. W-SW WINDS WILL BE AROUND 5-10 KTS FOR THIS EVENING DUE TO
THE LOSS OF DAYTIME HEATING/MIXING.
DURING THE OVERNIGHT HOURS...LOWER CLOUDS WILL CONTINUE TO INCREASE
FROM SOUTH TO NORTH...ESP BY LATE TONIGHT. VFR CONDITIONS WILL
CONTINUE THROUGH MOST OF THE OVERNIGHT HOURS. SOME LIGHT SNOWFALL
MAY START TO REACH TOWARDS KPOU TOWARDS DAYBREAK WEDNESDAY. ONCE
SNOW BEGINS...IT WILL QUICKLY REDUCE VSBY DOWN TO IFR CONDITIONS.
WINDS WILL BECOME LIGHT FOR LATE TONIGHT...AND BECOME N-NE FOR
WEDNESDAY MORNING...GENERALLY AROUND 5 KTS OR LESS.
SNOW WILL MOVE FROM SOUTH TO NORTH THROUGH THE MORNING HOURS...
REACHING KPSF AROUND 13Z...KALB AROUND 14Z AND KGFL AROUND 16Z.
ALL AREAS LOOK TO SEE IFR CONDITIONS SHORTLY AFTER SNOW BEGINS.
SNOW WILL INCREASE IN INTENSITY SEVERAL HOURS AFTER BEGINNING...
BECOMING MODERATE TO LOCALLY HEAVY FOR THE AFTN HOURS. WINDS
SHOULD TURN TO THE NORTH IN THE MORNING AND CONTINUE AT AROUND 5
KT THROUGH THE DAY.
OUTLOOK...
WED NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE SN.
THANKSGIVING DAY-NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
FRI: NO OPERATIONAL IMPACT. NO SIG WX.
SAT-SAT NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SUN: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDROLOGIC PROBLEMS ARE EXPECTED THROUGH THE
WEEKEND.
WIDESPREAD SNOWFALL AS COASTAL LOW IMPACTS REGION WEDNESDAY AND
WEDNESDAY NIGHT. WARMER TEMPERATURES SUNDAY WILL BE SHORT LIVED
AND WILL RESULT SOME SNOW MELT AND RIPENING OF SNOW PACK. HOWEVER
TEMPERATURES ARE EXPECTED TO BE IN THE MID 30S AND COLDER SATURDAY
NIGHT AND SUNDAY NIGHT SO MELT IS STOP.
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...WINTER STORM WARNING FROM 5 AM WEDNESDAY TO 7 AM EST THURSDAY
FOR CTZ001-013.
NY...WINTER STORM WARNING FROM 5 AM WEDNESDAY TO 7 AM EST THURSDAY
FOR NYZ058>061-063>066.
WINTER STORM WARNING FROM 7 AM WEDNESDAY TO 7 AM EST THURSDAY
FOR NYZ047>054-084.
WINTER WEATHER ADVISORY FROM 9 AM WEDNESDAY TO 7 AM EST
THURSDAY FOR NYZ032-033-038>043-082-083.
MA...WINTER STORM WARNING FROM 5 AM WEDNESDAY TO 7 AM EST THURSDAY
FOR MAZ001-025.
VT...WINTER STORM WARNING FROM 5 AM WEDNESDAY TO 7 AM EST THURSDAY
FOR VTZ013>015.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/NAS
SHORT TERM...IAA
LONG TERM...IRL
AVIATION...NAS
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
640 PM EST TUE NOV 25 2014
.SYNOPSIS...
LOW PRESSURE NEAR FLORIDA THIS EVENING WILL STRENGTHEN AS IT PASSES
NEAR THE MID ATLANTIC COAST WEDNESDAY, BEFORE RACING TO THE NORTHEAST
WEDNESDAY NIGHT. HIGH PRESSURE IS FORECAST TO BUILD ACROSS THE
EAST COAST FRIDAY INTO EARLY SATURDAY, BEFORE SQUEEZING TO THE
SOUTH SATURDAY NIGHT. A COLD FRONT IS EXPECTED TO SAG DOWN ACROSS
THE AREA SUNDAY NIGHT, BEFORE SLOWLY MOVING THROUGH THE AREA
MONDAY INTO MONDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
NO BIG CHANGES WITH THIS ESTF UPDATE. USED LATEST RAP RUNS TO MAKE
SOME MINOR POP ADJUSTMENTS OVERNIGHT. WHERE SKIES HAVE THINNED FAR
NORTHWEST, TEMPS HAVE DROPPED QUICKLY. BOTH THE 18Z GFS AND WRF-
NMMB HAVE CONTINUED THE WARMER TREND. WRF-NMMB IS NOW HALF SNOW AT
PHL AND IT WAS ALL SNOW WITH ITS 12Z RUN WHILE THE GFS IS MOSTLY
RAIN AT PHL EXCEPT FOR ONE DYNAMICALLY COOLED 3 HR PERIOD DURING
THE AFTERNOON. SOME OF THAT WARMTH HAS WAFTED AROUND 700MB
TEMPERATURES ABOVE FREEZING INTO THE I95 CORRIDOR AND SLEET IS
SHOWING UP AS A PTYPE. GOING TO WAIT AND SEE HOW THE MODELS
925MB/850MB FORECASTS VERIFY OFF THE 12Z SOUNDINGS, SO ONLY A
SLIGHT SHAVING OF SNOW TOTALS WAS DONE SOUTHEAST OF I95.
TONIGHT...THICKENING AND LOWERING CLOUDS AS DYNAMICS WITH THE
FLORIDA LOW AND GULF COAST SHORT WAVE FLOOD NORTHWARD. RAIN
DEVELOPS RAPIDLY FROM SOUTH SOUTHWEST TO NORTH NORTHEAST AFTER
MIDNIGHT AS LOW PRESSURE HEADS NEWD FOR THE NC COAST. NORTHERN
FRINGE REACHING KRDG/KABE AT 11Z MAY BEGIN AS RAIN/SNOW MIX PER
MARGINAL WARM BOUNDARY LAYER TEMPS (A WALL OF DEEP RH MOVING
NORTHWARD IN OUR CWA AFTER MIDNIGHT).
50 50 BLENDED 12Z/25 NCEP MOS GUIDANCE.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
UPDATE TO THIS SECTION COMING BY 330 PM.
**HIGH VISIBILITY HIGH IMPACT SNOW EVENT FOR ELEVATIONS OF E PA
AND NW NJ 9A-9P AND LIKELY A DEVELOPING IMPACT EVENT TO NEAR SEA
LEVEL JUST NW OF I-95 WEDNESDAY AFTERNOON/EVENING**
THIS FORECAST WAS A 50 50 BLEND OF THE 12Z/25 WARMER GFS AND COLDER
ECMWF PARTIAL THICKNESSES AND THEN ADJUSTING THE WET BULBING
12Z/25 BLENDED MOS TEMPS COLDER, ESPECIALLY WITH THE COLUMN ALL
SNOW DOWN TO 5000 FT AND ICE NUCLEI SEEDED FOR CRYSTALS BY CIRRUS.
LOW PRESSURE SYSTEM HAS BEEN TRENDING FASTER ONSET/DEPARTURE
SINCE FIRST DISCUSSED IN DETAILS THIS PAST WEEKEND.
SNOW GRIDS ARE POSTED.
WE SAW THE WARMER 18Z NAM (700MB ABOVE ZERO DOWN HERE NEAR PHL).
THE SNOW AMOUNTS NEAR I-95 FROM CECIL COUNTY MARYLAND THROUGH
WILMINGTON DELAWARE AND THEN NORTHEAST THROUGH PHILADELPHIA UP
TO NEW BRUNSWICK ARE HIGHLY UNCERTAIN. THE ADVISORY AREA SNOW
AMOUNTS ARE SHAKY AND WE MAY NOT MUCH MORE UNTIL NOON TOMORROW?
THE ADVISORY MAY NEED TO BE EXPANDED SOUTHWEST INTO NE MD IN
FUTURE FORECASTS.
POCKETS OF POWER OUTAGES A CONCERN...ESPECIALLY JUST NORTHWEST OF
INTERSTATE 95.
SUGGEST TRAVEL INTO EASTERN PENNSYLVANIA AND NORTHWEST NEW JERSEY
BE COMPLETED NO LATER THAN 7 AM WEDNESDAY, OR WAIT TIL AFTER 7 PM
WEDNESDAY NIGHT (IE...AFTER ROADS ARE CLEANED UP/CLEARED OF SLUSHY
SNOW). ITS THAT 12 HOUR WINDOW DURING THE DAY WEDNESDAY THAT IS
GOING TO BECOME A SIGNIFICANT TRAVEL PROBLEM, ESPECIALLY THE HILLY
AREAS.
ITS UNUSUAL TO FORECAST HEAVY WET SNOW IN A 1000-500MB 543-546 THICKNESS
WITHOUT A BIG (1030MB) SURFACE HIGH TO THE NORTH BUT THIS IS A SITUATION
THAT I THINK HEAVY SNOW WILL OCCUR, ESPECIALLY ELEVATIONS FOR REASONS
BELOW. THERMAL PROFILES AND PCPN MICROPHYSICS WITH CIRRUS SEEDING MARGINAL
-2 TO -8C BELOW 15,000 FEET!! THIS IS ANOTHER TEST OF THAT PRECIPITATION
MICROPHYSICS WHICH HAS WORKED SO WELL IN THE PAST.
AN INTENSIFYING 500MB 12HR 180 M HFC MOVING NEWD COMBINES WITH
ISALLOBARIC GRADIENT TO PULL 0-6KM 1C OR LESS WBZ AIR PROGRESSIVELY
SEWD TO NEAR I95 BY 18Z AND TO THE ATLANTIC COAST BY 00Z/27
(WEDNESDAY EVENING-TOO LATE FOR ANY SNOW SNJ AND DE COASTS).
ELEVATIONS CHANGE TO SNOW FIRST FROM NORTHWEST TO SOUTHEAST
WEDNESDAY MORNING.
PIVA AND COMMA HEAD SUGGEST SOME BANDING POTENTIAL VCNTY KRDG TO
KMPO DURING THE DAY. ALSO SUPPORT FROM CSI PRODUCT OF THE NAM BUT
AGAIN ITS THE NAM. THE MAX UVM RIGHT NOW IS TENDING TO SHOW UP BELOW
THE IDEAL DENDRITIC GROWTH ZONE IN THE MULTI MODEL PROFILES BUT
THAT CAN CHANGE.
A RECORD DAILY SNOWFALL FOR ALLENTOWN PA IS LIKELY TO OCCUR (A
VULNERABLE RECORD).
SNOW WATER RATIOS PER INTERNAL COLLABORATION 6 TO 1 I-95 MAYBE
8 TO 1 KRDG TO KABE AND 10 OR 12 TO 1 FOR THE POCONOS.
SMALL CHANCE OF MINOR TIDAL FLOODING ALONG THE DE COAST FOR
TOMORROW MORNINGS HIGH TIDE.
SMALL CHANCE WE`LL NEED A WIND ADVISORY FOR THE DELAWARE COAST
TOMORROW MORNING.
SNOW/PRECIPITATION ENDS FROM SW TO NE WEDNESDAY EVENING WITH SOME
REMAINING BANDING SNOW OVER NE PA AND NW NJ.
FLURRIES MAY OCCUR LATE AT NIGHT?
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
ON THANKSGIVING, THERE WILL REMAIN A CHANCE FOR ISOLATED SHOWERS FOR
PORTIONS OF THE AREA, ALTHOUGH WE EXPECT MOST AREAS TO REMAIN DRY.
THERE COULD REMAIN SOME SNOW SHOWERS IN THE NORTHERLY FLOW ACROSS
OUR NORTHERN AREAS, AND AS A SHORT WAVE ROUNDS THE BASE OF THE
TROUGH ALOFT, IT MAY HELP CREATE AN AREA OF SHOWERS ACROSS THE
SOUTHERN PORTIONS OF THE AREA AS WELL. MOST AREAS SHOULD STAY
PRECIP FREE, BUT IF IT DOES SNOW ACROSS THE NORTHERN ELEVATIONS, A
LIGHT ACCUMULATION COULD OCCUR WITH SOME SHOWERS. BY THURSDAY
NIGHT, ANY PRECIPITATION IS EXPECTED TO END AS WE BEGIN TO LOSE
GOOD MOISTURE ALOFT.
FRIDAY INTO EARLY SATURDAY, HIGH PRESSURE BEGINS TO BUILD ACROSS THE
EAST COAST, WHICH IS EXPECTED TO KEEP THE WEATHER MOSTLY
PRECIPITATION FREE. THE MODELS DO PUSH A WEAK SHORT WAVE/VORTICITY
IMPULSE ACROSS THE AREA FRIDAY NIGHT, WITH THE GFS SHOWING MORE
MOISTURE TO WORK WITH THAN THE ECMWF. FOR NOW WE WILL KEEP THE
WEATHER DRY UNTIL WE GET BETTER COLLABORATION BETWEEN THE TWO.
THE HIGH PRESSURE PUSHES TO OUR SOUTH LATER SATURDAY INTO EARLY
SUNDAY, BEFORE A FRONTAL BOUNDARY APPROACHES THE AREA SUNDAY NIGHT
INTO MONDAY. MODELS ARE HINTING AT A SLIGHT CHANCE OF SHOWERS
SATURDAY NIGHT INTO SUNDAY AS A COUPLE OF WEAK SHORT WAVE/VORTICITY
IMPULSES SLIDE ACROSS THE AREA. HOWEVER, THE GREATER THREAT IS
EXPECTED TO BE SUNDAY NIGHT INTO MONDAY NIGHT AS THE FRONTAL
BOUNDARY SAGS ACROSS THE AREA. MODELS INDICATE THAT SOME MOISTURE
IS LOST AS THE FRONT SAGS ACROSS THE AREA, BUT THERE WILL REMAIN A
CHANCE IN THE FORECAST FOR NOW.
AS HIGH PRESSURE BUILDS BACK ACROSS THE NORTHEAST ON TUESDAY, DRY
WEATHER SHOULD RETURN TO THE AREA THROUGH TUESDAY.
AFTER BELOW NORMAL TEMPERATURES FOR THE FIRST HALF OF THE
EXTENDED THROUGH SATURDAY, A WARMING TREND IS EXPECTED FOR THE
LATTER HALF OF OF THE WEEKEND INTO EARLY NEXT WEEK WITH
TEMPERATURES RETURNING ABOVE NORMAL.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
HIGH IMPACT IFR CONDITIONS PREDICTED FOR WEDNESDAY.
FOR TONIGHT PRIMARILY VFR (HIGH LEVEL AND THEN MID LEVEL CLOUDS),
POSSIBLY BECOMING MVFR TOWARD MORNING AS PCPN (MAINLY RAIN) MOVES
INTO THE AREA. WIND DIRECTION FORECAST IS MORE FOR THE OVERNIGHT.
WEDNESDAY, KABE AND KRDG IFR CONDITIONS WITH SNOW AS THE
PREDOMINATE PTYPE BY THE MIDDLE OF THE MORNING. ACCUMULATIONS ON
RUNWAYS LIKELY. SOME IMPROVEMENT LATE. NORTH WINDS WILL AVERAGE
AROUND 10 TO 15 KNOTS. KPHL/I95 CORRIDOR TERMINALS. MVFR
CONDITIONS IN RAIN DURING THE MORNING LOWERING TO IFR LATE MORNING
AS SNOW STARTS TO MIX IN AND PROBABLY BECOMES THE PREDOMINANT
PTYPE. SOME SLUSHY ACCUMS ON RUNWAYS POSSIBLE. WE ADDED THE
POSSIBILITY OF SLEET AS A PTYPE. MVFR IMPROVEMENT LATE. NORTHEAST
WINDS WILL AVERAGE 10 TO 20 KNOTS WITH PEAK GUSTS CLOSE TO 30
KNOTS. KMIV AND KACY AS WELL AS SHORE POINT AIRPORTS, IFR
CONDITIONS DUE TO PREDOMINATELY MODERATE RAIN. SOME SNOW MIGHT MIX
IN DURING THE AFTERNOON. NORTHEAST WINDS WILL AVERAGE 12 TO 18
KNOTS WITH PEAK GUSTS ALSO CLOSE TO 30 KNOTS, POSSIBLY HIGHER AT
COASTAL AIRPORTS.
OUTLOOK...
WEDNESDAY NIGHT...BECOMING VFR WITH DIMINISHING WINDS.
THURSDAY-THURSDAY NIGHT...MOSTLY VFR. ISOLATED RAIN OR SNOW SHOWERS
POSSIBLE DURING THE DAY WHICH MAY TEMPORARILY LOWER CONDITIONS.
FRIDAY-SUNDAY...MOSTLY VFR. WIND GUSTS 15-20 KNOTS EACH DAY; NW
FRIDAY, SW SATURDAY & SUNDAY.
&&
.MARINE...
EARLY TOMORROW MORNING, GALE CONDITIONS ARE FORECAST FOR THE
LOWER DELAWARE BAY AND THE ATLANTIC COASTAL WATERS...ESPECIALLY
SOUTHERN NJ AND THE DE COASTAL WATERS.
WED...A FULL BLOWN GALE WARNING IS IN EFFECT FOR THE COASTAL WATERS
AND LOWER DELAWARE BAY PER AN INTENSIFYING STORM MOVING NEWD FROM
THE NC COAST. SCA CONDITIONS EXPECTED ON THE UPPER DELAWARE BAY
WITH A POSSIBLE NEED FOR AN UPGRADE TO A SHORT FUSE GALE WARNING.
THE 06Z, 12 AND 18Z NAM ARE ADVERTISING A PERIOD OF STORM FORCE
WINDS VCNTY 44009 AROUND MIDDAY WEDNESDAY (NEAR 50 KT). WE WILL
NOT KNOW FOR SURE SINCE NO 44009 WIND DATA.
WED NIGHT...GALE CONDITIONS WILL CONTINUE EARLY, THEN SEAS AND WIND
WILL DECREASE AND AND SCA WILL BE LIKELY NEEDED AS THE STORM MOVES
NORTHEAST OF CAPE COD.
OUTLOOK...
THURSDAY-THURSDAY NIGHT...WINDS ARE EXPECTED TO BE BELOW SMALL CRAFT
ADVISORY LEVELS, BUT SEAS MAY REMAIN ELEVATED INTO THURSDAY NIGHT.
FRIDAY-FRIDAY NIGHT...SUB-SMALL CRAFT ADVISORY CONDITIONS EXPECTED
AS HIGH PRESSURE BUILDS OVER THE AREA.
SATURDAY-SUNDAY...NEAR SMALL CRAFT ADVISORY CONDITIONS POSSIBLE AS
HIGH PRESSURE PUSHES TO OUR SOUTH AND COLD FRONT APPROACHES LATE ON
SUNDAY NIGHT.
&&
.CLIMATE...
REGARDING THE MIDWEEK COASTAL STORM BRINGING SNOW TO A LARGE
PORTION OF OUR REGION, WE HAVE INCLUDED DAILY SNOWFALL RECORDS
BELOW FOR OUR FOUR PRIMARY CLIMATE SITES THAT HAVE A LONG-STANDING
UNBROKEN PERIOD OF RECORD (POR) WITH RESPECT TO HISTORICAL
SNOWFALL DATA.
DAILY SNOWFALL RECORDS:
NOVEMBER 26TH: NOVEMBER 27TH: PERIOD OF RECORD:
ACY: TRACE 1977,1957,1955 1.2 INCHES 1978 1874
PHL: 6.0 INCHES 1898 6.9 INCHES 1949,1938 1872
ILG: 0.1 INCHES 1950 4.5 INCHES 1978 1894
ABE: 1.7 INCHES 1925 7.0 INCHES 1938 1922
OTHER COOPERATIVE SITE SHORTER HISTORICAL RECORD CAN BE FOUND AT
THE NWS MOUNT HOLLY WEBSITE UNDER NOW DATA.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WARNING FROM 7 AM TO 10 PM EST WEDNESDAY FOR
PAZ054-055-060>062-101-103-105.
WINTER WEATHER ADVISORY FROM 9 AM TO 10 PM EST WEDNESDAY FOR
PAZ070-071-102-104-106.
NJ...WINTER STORM WARNING FROM 7 AM TO 10 PM EST WEDNESDAY FOR
NJZ001-007>010.
WINTER WEATHER ADVISORY FROM 9 AM TO 10 PM EST WEDNESDAY FOR
NJZ012-015.
DE...NONE.
MD...NONE.
MARINE...GALE WARNING FROM 4 AM TO 10 PM EST WEDNESDAY FOR ANZ431-
450>455.
SMALL CRAFT ADVISORY FROM 4 AM TO 10 PM EST WEDNESDAY FOR
ANZ430.
&&
$$
SYNOPSIS...ROBERTSON
NEAR TERM...DRAG/GIGI
SHORT TERM...DRAG
LONG TERM...ROBERTSON
AVIATION...GIGI/ROBERTSON
MARINE...DRAG/ROBERTSON
CLIMATE...
AREA FORECAST DISCUSSION
NWS MIAMI FL
1009 PM EST TUE NOV 25 2014
.UPDATE...
SHOWERS AND STORMS PROGRESSING MUCH SLOWER TO THE SOUTH AND EAST
THAN GUIDANCE PROJECTS, AND THIS HAS BEEN THE CASE FOR SEVERAL
RUNS. THEREFORE HAVE SLOWED CHC AND LIKELY POPS BY ABOUT 6HRS FROM
PREVIOUS FORECAST. ACROSS THE GULF WATERS AND EXTREME NW POPS WERE
LEFT ALONE. WITH THE DEEP WARM, MOIST SOUTHERLY FLOW ACROSS
SOUTH FLORIDA, SHOWERS HAVE DEVELOPED IN THE STRAITS AND PERHAPS
WILL CROSS INTO THE ATLANTIC WATERS AND MIAMI DADE OVER THE NEXT
SEVERAL HOURS ALTHOUGH SCATTERED. WITH THE FRONT CROSSING AT THE
MOST CLIMATOLOGICALLY UNFAVORABLE TIME TOMORROW MORNING, AND THE
MID LEVEL UVV/VORTICITY QUICKLY WEAKENING, NOT EXPECTING MUCH
LIFT WITH THE BOUNDARY TOMORROW MORNING. THIS SEEMS TO BE
REFLECTED IN THE MODELS, WITH QPF QUICKLY DROPPING OFF ACROSS THE
EAST COAST INTO TOMORROW MORNING. ANY CHANCE FOR A STRONGER STORM
WITH DECENT WIND GUSTS WILL REMAIN RESERVED ACROSS THE NW CWA AND
LAKE REGION LATE TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 656 PM EST TUE NOV 25 2014/
AVIATION...MVFR CIGS ARE LIKELY TO DEVELOP OVERNIGHT. IFR CIGS
ARE POSSIBLE, BUT LESS CERTAIN. GUIDANCE HAS BEEN TOO AGGRESSIVE
PAST TWO NIGHTS SHOWING IFR TO ONLY NOT OCCUR AT MOST LOCALES.
FOR THIS REASON, WENT WITH PREVAILING MVFR CIGS WITH A SCT005 AND
WILL CLOSELY MONITOR TRENDS.
IMPRESSIVE TROUGH DIGGING INTO THE GULF WITH CONVECTION ALL THE
WAY TO THE YUCATAN. AS THIS SLIDES EAST, THERE IS THE POTENTIAL
FOR A BROKEN LINE OF TSRA TO MOVE THROUGH SOUTH FL. HOWEVER, THE
STORMS IN THE GULF ARE ONLY SLOWLY PROGRESSING EASTWARD AND
POLYGON TIME TRACKING SUGGESTS A LATE NIGHT ARRIVAL AFTER MIDNIGHT
FOR KAPF AND NOT UNTIL DAWN FOR THE EAST COAST. LATEST HRRR RUN
SHOWS NO QPF EAST COAST UNTIL AFTER 10Z. THIS SEEMS REASONABLE
WITH OUR TIMING ANALYSIS, SO HAVE FOLLOWED THIS. IFR OR LIFR
VIS/CIGS ARE POSSIBLE IN ANY HEAVIER TSRA WHICH MOVES THROUGH WITH
IMPACT POTENTIAL HIGHEST FROM 05-09Z AT KAPF AND 09-14Z FOR THE
EAST COAST TERMINALS. GREATEST THREAT KAPF TO KFLL AND POINTS
NORTH. GUST WIND POTENTIAL ~40KT POSSIBLE. ANY SIGNIFICANT IMPACTS
WOULD BE BRIEF THOUGH. THX CWSU MIAMI FOR COLLABORATION! /GREGORIA
PREV DISCUSSION... /ISSUED 356 PM EST TUE NOV 25 2014/
.A FEW STRONG STORMS POSSIBLE LAKE OKEECHOBEE/WEST COAST TONIGHT...
.ROUGH MARINE CONDITIONS ON WEDNESDAY FOR ALL SOUTH FLORIDA WATERS...
.DRIER AND COOLER WEATHER THIS THANKSGIVING WEEKEND...
SHORT TERM... A MID TO UPPER LEVEL TROUGH OF LOW PRESSURE THAT
EXTENDED FROM THE GREAT LAKES SOUTHWEST INTO THE NORTHWEST GULF OF
MEXICO WILL CONTINUE TO MOVE TO THE EAST TONIGHT AND BE LOCATED OVER
THE EASTERN UNITED STATES BY WEDNESDAY MORNING. THIS WILL PUSH HIGH
PRESSURE OVER THE WESTERN ATLANTIC WATERS FURTHER EASTWARD INTO THE
ATLANTIC. LOW PRESSURE OVER THE EASTERN GULF OF MEXICO WILL THEN
MOVE NORTHEAST ALONG THE STATIONARY FRONT THAT IS LOCATED OVER
CENTRAL FLORIDA.
THIS WEATHER PATTERN WILL ALLOW FOR THE SURFACE WINDS TO BECOME MORE
SOUTHWEST OVER SOUTH FLORIDA TONIGHT BRINGING IN THE TROPICAL
MOISTURE FROM THE GULF OF MEXICO INTO SOUTH FLORIDA.
THEREFORE...POPS WILL BE ON AN INCREASE OVER SOUTH FLORIDA TONIGHT
FROM WEST TO EAST...SCATTERED TO NUMEROUS BY LATE TONIGHT WITH THE
HIGHEST POPS OVER THE LAKE OKEECHOBEE REGION AND WEST COAST METRO
AREAS.
THERE IS ALSO A THREAT OF A FEW STRONG STORMS OVER THE LAKE
OKEECHOBEE AND WEST COAST METRO AREAS LATE THIS AFTERNOON INTO
TONIGHT...AS THE LATEST SHORT RANGE MODELS CONTINUE TO INDICATE A
MID LEVEL JET OF 50 KNOTS MOVING THROUGH CENTRAL FLORIDA TONIGHT
ASSOCIATED WITH THE LOW. THE PRIMARY IMPACTS FROM THE STRONG
STORMS WILL BE FREQUENT LIGHTNING STRIKES...GUSTY WINDS...AND HEAVY
RAINFALL THIS AFTERNOON INTO EARLY THIS EVENING.
THE LOW WILL CONTINUE TO MOVE NORTHEAST UP THE EAST COAST OF THE
UNITED STATES ON WEDNESDAY. THIS WILL ALLOW FOR THE STATIONARY
FRONT TO BECOME A COLD FRONT TONIGHT...AND PUSH SOUTHWARD THROUGH
SOUTH FLORIDA WEDNESDAY MORNING BEFORE MOVING INTO THE FLORIDA
KEYS WEDNESDAY AFTERNOON. THEREFORE...THE POPS WILL REMAIN IN THE
SCATTERED TO NUMEROUS RANGE WEDNESDAY MORNING BEFORE DECREASING IN
COVERAGE WEDNESDAY AFTERNOON.
HIGH PRESSURE WILL THEN BUILD INTO THE SOUTHEASTERN UNITED STATES
WEDNESDAY NIGHT THROUGH FRIDAY KEEPING A NORTHERLY WIND FLOW OVER
SOUTH FLORIDA. THIS NORTHERLY WIND FLOW WILL BRING IN DRIER AND
COOLER WEATHER TO SOUTH FLORIDA FOR THANKSGIVING AND FRIDAY.
LOWS WILL BE IN THE 40S OVER MOST OF SOUTH FLORIDA FOR WEDNESDAY
NIGHT AND THURSDAY NIGHT...EXCEPT FOR LOWER TO MID 50S EAST COAST
METRO AREAS. HIGHS WILL BE IN THE LOWER TO MID 70S FOR THANKSGIVING
DAY AND FOR FRIDAY.
LONG TERM...
THE HIGH WILL THEN MOVE SLOWLY EAST INTO THE WESTERN ATLANTIC
WATERS THIS THANKSGIVING WEEKEND ALLOWING FOR THE WINDS TO SLOWLY
SWING TO A EASTERLY DIRECTION AND BECOME BREEZY. THIS WILL KEEP
SOUTH FLORIDA DRY AND ALLOW FOR THE TEMPERATURES TO SLOWLY WARM UP
THROUGH THE WEEKEND...WITH HIGHS IN THE MID TO UPPER 70S AND LOWS IN
THE 50S EXCEPT 60S EAST COAST METRO AREAS.
MARINE...
THE WINDS WILL SWING FROM A SOUTHERLY DIRECTION OF 10 TO 15 KNOTS TONIGHT
TO A NORTHERLY DIRECTION ON WEDNESDAY AND INCREASE QUICKLY TO 20
TO 25 KNOTS WITH GUSTS GETTING CLOSE TO GALE FORCE IN THE OFFSHORE
GULF WATERS. THE NORTHERLY WINDS WILL CONTINUE WEDNESDAY NIGHT
INTO THANKSGIVING DAY AS THE WIND SPEEDS DECREASE TO 15 TO 20
KNOTS.
BOTH THE ATLANTIC AND GULF SEAS WILL REMAIN BELOW 6 FEET TONIGHT
BEFORE INCREASING TO AT LEAST 7 FEET ON WEDNESDAY. THE OFFSHORE
GULF WATERS COULD EVEN GET UP TO 9 TO 11 FEET ON WEDNESDAY.
THEREFORE...IT LOOKS LIKE AN SCA WILL BE NEEDED SOON FOR ALL OF THE
SOUTH FLORIDA WATERS FOR THE WINDS AND SEAS IN THE ATLANTIC AND GULF
WATERS...FOR WEDNESDAY INTO WEDNESDAY NIGHT.
THE THREAT OF RIP CURRENTS WILL ALSO CONTINUE ALONG THE EAST COAST
BEACHES THIS THANKSGIVING WEEKEND AND FOR THE GULF BEACHES OF
SOUTH FLORIDA FOR WEDNESDAY.
FIRE WEATHER... THE RELATIVE HUMIDITY SHOULD FALL BELOW THE 35
PERCENT CRITICAL VALUE ON THANKSGIVING DAY OVER SOUTH FLORIDA DUE TO
DRIER AIR WORKING INTO THE AREA FROM THE NORTH. HOWEVER...THE ERC
WILL REMAIN IN THE UPPER TEENS TO LOWER 20S AND THE 20 FOOT WINDS
WILL REMAIN BELOW 15 MPH ON THANKSGIVING DAY. THEREFORE...NO FIRE
DANGER STATEMENT WILL BE ISSUED FOR SOUTH FLORIDA FOR THANKSGIVING
DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 72 75 49 73 / 30 70 10 0
FORT LAUDERDALE 74 79 55 75 / 30 60 10 0
MIAMI 74 78 56 76 / 30 60 10 0
NAPLES 66 68 48 73 / 100 70 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...21/KM
LONG TERM....54/BNB
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
817 PM EST TUE NOV 25 2014
.DISCUSSION...
...FLOOD WATCH OSCEOLA AND BREVARD NORTHWARD INTO WEDNESDAY...
...NUMEROUS SHOWERS AND STORMS...
...TURNING COLDER AREA WIDE WEDNESDAY NIGHT...
...HAZARDOUS CONDITIONS COASTAL WATERS THROUGH THURSDAY AFTERNOON...
CURRENT-OVERNIGHT...MID LEVEL TROUGH CURRENTLY OVER THE SOUTHERN
PLAINS TRACKS TO THE LOWER MISSISSIPPI RIVER VALLEY AND THE
MISSISSIPPI RIVER DELTA TOWARD SUNRISE WEDNESDAY. THE PREVAILING
SOUTHWESTERLY FLOW ALOFT WILL CONTINUE TO PULL DEEP LAYER MOISTURE
OVER THE FLORIDA PENINSULA. MID LEVEL IMPULSES IN THE SOUTHWEST
FLOW ALOFT AND APPROACHING RIGHT REAR QUADRANT OF THE UPPER LEVEL
JET WILL KEEP CLOUDS AND RAIN OVERNIGHT. SETUP IS FAVORABLE FOR
MORE TRAINING HEAVY RAIN CELLS THEREFORE THE FLOOD WATCH FROM
OSCEOLA BREVARD NORTH STILL LOOKS GOOD. BOTH THE LATEST
GFS 25/18Z AND THE RUC ARE INDICATING A WAVE FORMING ALONG AN OLD
BOUNDARY AS IT LIFTS NORTH. BOTH CLOSE OFF THE LOW AND HAVE IT MOVING
RAPIDLY NORTHEAST OVERNIGHT ENDING UP OFF THE WILMINGTON NC AREA
AROUND SUNRISE WED WITH THE WINDS SHIFTING TO THE NORTHWEST BEHIND
THE FRONT.
UPDATED THE OVERNIGHT WIND AND ITS ASSOCIATED GRIDS AND REPLACED
THE SCATTERED/CHANCE OF STORMS WITH AN ISOLATED/SLIGHT CHANCE OF
STORMS. THE REST OF THE FORECAST REMAINS UNCHANGED.
PREVIOUS ZONES DISCUSSION
CURRENT-TONIGHT...WIDESPREAD SHOWERS AND SCATTERED STORMS ONGOING
ALONG AND NORTH OF THE I-4 CORRIDOR EARLY THIS AFTERNOON. MANY
LOCALES WITHIN THIS AREA REPORTING 2-5 INCH RAINS WITH NUISANCE
FLOODING. UNSEASONABLY WARM AND MOIST CONDITIONS ACROSS ECFL WITH
THE DEEP SOUTHERLY FLOW. ADDITIONAL HEAVY RAINFALL LIKELY ACROSS
EAST CENTRAL FLORIDA OVERNIGHT...HENCE THE FLOOD WATCH ISSUANCE FOR
BREVARD-OSCEOLA NORTHWARD THROUGH WED MORNING. THE AREA UNDER THE
GUN FOR HEAVY RAINFALL IN THE NEAR TERM REMAINS ALONG THE I-4
CORRIDOR AS ECHOES CONTINUE TO TRAIN HERE. THE FOCUS WILL GRADUALLY
SHIFT SLOWLY SOUTHWARD LATE THIS EVENING AND OVERNIGHT. AN
ADDITIONAL 2-4 INCHES OF RAINFALL LIKELY OVER MUCH OF THE FLOOD
WATCH COVERAGE AREA THROUGH WED MORNING WITH LOCALLY HIGHER AMOUNTS
POSSIBLE. LOCALIZED RUNOFF PROBLEMS WILL ALSO BE POSSIBLE. HEAVIEST
RAINFALL POTENTIAL FOR AREAS OF CENTRAL OSCEOLA-SOUTHERN BREVARD
SOUTHWARD WILL RANGE FROM LATE EVENING-OVERNIGHT-EARLY WED MORNING.
RECENT INFRARED SATELLITE IMAGERY SHOWS DEVELOPING COLDER CLOUD TOPS
ORGANIZING WITH HEAVY CONVECTION UNDERNEATH. KMLB NEXRAD 88D RADAR
SHOWS SCATTERED SHOWERS/ISOLATED STORMS DEVELOPING FURTHER SOUTH OF
I-4 WITH THESE CELLS ADVANCING NORTHWARD AT 20 TO 25 MPH.
THE SPC HAS KEPT A SLIGHT RISK OF SEVERE STORMS FOR THIS
AFTERNOON/TONIGHT ACROSS MUCH OF EAST CENTRAL FLORIDA. MANY FEATURES
REMAINING IN PLAY FOR DEEP CONVECTION/STRONG STORM POTENTIAL INCLUDE
DEEP MOISTURE/LOW-LEVEL SOUTHERLY FLOW...UNSEASONABLY WARM
TEMPERATURES...SUBTLE IMPULSES IN THE MID-LEVEL FLOW...MODEST
INSTABILITY AND STRONG UPPER JET OVER THE DEEP SOUTH PROVIDING
STRONG DIFFLUENCE ALOFT. HOW ALL OF THESE PARAMETERS COME TOGETHER
STILL REMAINS TO BE SEEN. THREATS FROM STORMS INCLUDE...TORRENTIAL
RAINFALL/NUISANCE FLOODING...FREQUENT LIGHTNING...GUSTY DOWNBURST
WINDS IN EXCESS OF 50 MPH...SMALL HAIL AND/OR A SHORT-LIVED WEAK
TORNADO OR TWO. A WEATHER WATCH MAY STILL BE NECESSARY LATER
TODAY/TONIGHT.
THE QUASI-STATIONARY FRONTAL BOUNDARY REMAINS HUNG UP ACROSS NORTH
CENTRAL FL THIS AFTERNOON BUT WILL EVENTUALLY GET A KICK SOUTH AND
EAST AS A VIGOROUS UPPER TROUGH MOVES EASTWARD ACROSS THE DEEP SOUTH
AND GOMEX. AN AREA OF LOW PRESSURE OVER THE EASTERN GULF WILL RIDE
UP ALONG THE BOUNDARY ACROSS NORTH FLORIDA THIS EVENING...THEN OFF
OF THE NORTHEAST FL COAST OVERNIGHT. CURRENT THINKING IS THAT THE
FRONT WILL BE SOMEWHERE ACROSS OUR CENTRAL/SOUTHERN CWA BY AROUND
SUNRISE WED MORNING. WHILE THE HEAVIEST BANDS OF PRECIPITATION WILL
BE ALONG AND JUST OUT AHEAD OF THIS BOUNDARY...SOME SCATTERED
SHOWERS WILL STILL LINGER AROUND BEHIND IT WITH SHOWERY
PRECIPITATION ENDING FROM NORTH TO SOUTH FROM LATE MORNING THROUGH
THE AFTERNOON WED. SOUTHERLY WINDS AHEAD OF THE FRONT WILL BECOME W/NW
BEHIND IT WITH BREEZY/GUSTY CONDITIONS LASTING FOR AT LEAST A FEW
HOURS AFTER PASSAGE. TIMING OF FRONT ALONG WITH THICK
CLOUDS/PRECIPITATION WILL MAKE OVERNIGHT LOWS CHALLENGING.
TEMPERATURES ALONG/NORTH OF I-4 ARE FORECAST TO DROP LATE OVERNIGHT
INTO THE MIDDLE/UPPER 50S WITH 60S FURTHER SOUTHWARD...EXCEPT LOWER
70S POSSIBLE ALONG THE IMMEDIATE TREASURE COAST.
WED...THE FRONT WILL CONTINUE THROUGH ECFL THROUGH THE MORNING WITH
THE HEAVIEST SHOWER/STORM ACTIVITY MOVING OFF OF THE EAST COAST AND
OUT ACROSS THE COASTAL WATERS BY LATE MORNING/EARLY AFTERNOON. THE
AFOREMENTIONED SURFACE LOW WILL RACE UP THE ATLANTIC EAST COAST
DURING THE DAY. THE UPPER TROUGH IS FORECAST TO WEAKEN SIGNIFICANT
AS IT PUSHES THROUGH BETWEEN 12Z-18Z...SO EXPECT DECREASING TREND
FOR BOTH COVERAGE/INTENSITY OF PRECIPITATION NEAR THIS TIME.
BREEZY/GUSTY W/NW WINDS WILL FOLLOW BRIEFLY WITH WIND SPEEDS
SETTLING DOWN TO 10-15 MPH DURING THE DAY WITH OCNL HIGHER WIND
GUSTS. TEMPERATURES AT SUNRISE WILL BE THE HIGHEST WE WILL SEE
DURING THE DAYLIGHT HOURS AS COOLER AIR FILTERS DOWN AND
TEMPERATURES FALL BEHIND THE BOUNDARY. DAYTIME HIGHS MAINLY IN THE
60S AREAWIDE...BUT THIS DAY WILL FEEL BOTH COOLER/DRIER THAN THE
PREVIOUS COUPLE OF DAYS.
WED NIGHT...(MODIFIED PREV DISC) STRONG COLD ADVECTION BEHIND THE
DEPARTING LOW PRESSURE CENTER WILL PUSH LOWS WELL INTO THE 40S
AREAWIDE WITH CLEARING SKIES. WINDS ARE FORECAST TO DIMINISH
RATHER QUICKLY TO LESS THAN 10 MPH PAST DUSK SO WIND CHILL ISSUES
ARE NOT EXPECTED TO BECOME HAZARDOUS DESPITE THE LOWER READINGS.
THU-THU NIGHT...REMAINING NOTICEABLY COOLER DESPITE FULL SUN THU
AS A DEEP NW FLOW PUSHES A DRY/STABLE AIRMASS ACRS THE FL
PENINSULA. TEMPS 5-10F BLO CLIMO. MAX TEMPS WILL STRUGGLE TO REACH
THE 70F MARK...RANGING FROM THE M/U60S ALONG AND N OF I-4 TO ARND
70F ALONG THE TREASURE COAST. MIN TEMPS WILL BE IN THE L/M40S OVER
THE INTERIOR AND IN THE U40S/L50S ALNG THE COAST.
FRI-MON...SLOW WARMING TREND WILL PREVAIL INTO EARLY NEXT WEEK AS
THE POST FRONTAL RIDGE DRIFTS ACRS THE GOMEX/DEEP SOUTH AND INTO
THE W ATLC. N/NWRLY FLOW WILL KEEP TEMPS AOB CLIMO AVG THRU SAT
NIGHT WITH MAX TEMPS M60S/L70S...MIN TEMPS M/U40S INTERIOR AND
U40/M50S ALONG THE COAST. WINDS WILL VEER TO ENE ON SAT THEN TO
THE E ON SUN AS THE RIDGE BUILDS INTO THE W ATLC. THE ONSHORE
COMPONENT WILL PUSH OCEAN MODIFIED AIR BACK ONSHORE...ALLOWING MAX
TEMPS TO RECOVER TO CLIMO BY SUN AFTN WITH MAXES L/M70S...MINS
M/U50S INTERIOR AND U50/L60S ALONG THE COAST.
&&
.AVIATION...
CURRENT-OVERNIGHT...REVAILING MVFR CONDITIONS THROUGH MIDNIGHT
THEN IFR IS AREAS OF RAIN THE REMAINDER OF THE NIGHT. GUIDANCE
SUGGESTING MVFR CONDITIONS WITH PERIODS OF RAIN AND ISOLATED
STORMS AFTER 26/12Z.
PREVIOUS AVIATION DISCUSSION
TORRENTIAL RAINFALL ALONG I-4 CORRIDOR INTO TONIGHT WITH FRONT
CROSSING INTO THE CENTRAL PENINSULA LATE OVERNIGHT INTO EARLY WED
MORNING. CURRENT...PREVAILING MVFR VSBYS/CIGS MANY SITES WITH
WIDESPREAD PRECIP CONTINUING TONIGHT. LCL IFR VSBYS IN +SHRA/TS.
GRADUAL IMPROVING CONDITIONS FROM NORTH TO SOUTH DURING THE DAY ON
WED BEHIND FRONT. BREEZY/GUSTY W/NW WINDS FOR A FEW HOURS
IMMEDIATELY AS FRONT PASSES.
&&
.MARINE...
CURRENT-OVERNIGHT...NOAA BUOYS 009/010 WERE SOUTH SOUTHEAST WINDS 23
KNOTS/17 KNOTS 6/7 FOOT SEAS RESPECTIVELY. THE TWO NEARSHORE SCRIPPS
BUOYS WERE RECORDING 5 FOOT SEAS OUT TO 6NM.
SMALL CRAFT ADVISORY FOR ALL MARINE ZONES THROUGH 4 PM WEDNESDAY.
PREVIOUS MARINE DISCUSSION
AFTERNOON-TONIGHT...WILL START OFF WITH STRONGLY WORDED CAUTIONARY
STATEMENTS OFFSHORE FOR SOUTHERLY WINDS 15-20 KTS/GUSTY AND SEAS
BUILDING TO 4-6 FT. AS FRONT ENTERS THE WATERS LATER THIS
EVENING/OVERNIGHT NORTHWEST WINDS QUICKLY BECOME 25-30 KTS AND
GUSTY OVER THE OPEN ATLANTIC SPREADING NORTH TO SOUTH. SEAS
BUILDING TO 6-9 FT OFFSHORE/NORTH OF SEBASTIAN INLET BY DAYBREAK.
SMALL CRAFT ADVISORY CONDITIONS ACROSS ALL MARINE LEGS NEAR
DAYBREAK WED MORNING. CONDITIONS WILL BE HAZARDOUS FOR SMALL CRAFT
BOATING.
WIDESPREAD (OFFSHORE MOVING) SHOWERS/SCT STRONG STORMS FROM CAPE
NORTHWARD WILL EVENTUALLY SPREAD SOUTHWARD DOWN THE COASTAL WATERS
LATER THIS EVENING AND OVERNIGHT. ANY STRONGER CELLS ARE CAPABLE OF
TORRENTIAL DOWNPOURS...WINDS IN EXCESS OF 35 KTS...FREQUENT CLOUD TO
WATER LIGHTNING...SMALL HAIL AND/OR WATERSPOUT. A WEATHER WATCH MAY
BECOME NECESSARY.
WED...COLD FRONT WILL CROSS THE COASTAL WATERS BY LATE MORNING/EARLY
AFTERNOON. OCCASIONAL GUSTS TO GALE FORCE OVER THE OPEN ATLANTIC ARE
LIKELY. SMALL CRAFT ADVISORY CONDITIONS ALL LEGS. HAZARDOUS BOATING
CONDITIONS FOR SMALL CRAFT. SEAS BUILDING 6-9 FT OFFSHORE/5-7 FT
NEAR SHORE. SHOWERS/STORMS GRADUALLY ENDING FROM NORTH TO SOUTH IN
THE AFTERNOON.
THU-SAT...(PREV DISC) IMPROVING CONDITIONS THRU THE END OF THE WEEK AS
A POST FRONTAL HI PRES RIDGE BUILDS FROM THE CENTRAL CONUS INTO
THE W ATLC. SFC PGRAD WILL SLACKEN...ALLOWING WINDS TO VEER FROM
NW TO E AND DIMINISH... MODERATE TO FRESH NW BREEZE ON THU...BCMG
A GENTLE TO MODERATE N/NE BREEZE ON FRI...THEN A LIGHT TO GENTLE
E/NE BREEZE ON SAT. SEAS WILL WILL REMAIN HAZARDOUS THRU FRI AS
WINDS SWING THRU NE...ESPECIALLY IN THE GULF STREAM WHERE THE NRLY
WIND/SRLY CURRENT COMPONENT WILL GENERATE SQUARE WAVES. SEAS 4-6FT
NEARSHORE AND 6-8FT OFFSHORE ON THU...SUBSIDING TO 3-5FT NEARSHORE
AND 5-6FT OFFSHORE ON FRI...THRU SUNSET THU...THEN 3-4FT NEARSHORE
AND 4-5FT OFFSHORE ON SAT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 57 65 44 66 / 100 80 0 0
MCO 58 65 43 67 / 90 80 0 0
MLB 61 65 46 70 / 80 80 0 0
VRB 64 69 46 71 / 70 80 10 0
LEE 57 65 43 66 / 100 80 0 0
SFB 58 66 44 67 / 90 80 0 0
ORL 58 65 44 68 / 90 80 0 0
FPR 65 68 47 72 / 70 80 10 0
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH THROUGH WEDNESDAY MORNING FOR COASTAL VOLUSIA-INLAND
VOLUSIA-NORTHERN BREVARD-NORTHERN LAKE-ORANGE-OSCEOLA-
SEMINOLE-SOUTHERN BREVARD-SOUTHERN LAKE.
AM...SMALL CRAFT ADVISORY UNTIL 4 PM EST WEDNESDAY FOR COASTAL WATERS
FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE OUT 20 NM-
COASTAL WATERS FROM SEBASTIAN INLET TO JUPITER INLET OUT 20
NM-COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THURSDAY FOR WATERS FROM
FLAGLER BEACH TO VOLUSIA BREVARD COUNTY LINE 20 TO 60 NM
OFFSHORE-WATERS FROM SEBASTIAN INLET TO JUPITER INLET 20 TO
60 NM OFFSHORE-WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET 20 TO 60 NM OFFSHORE.
&&
$$
IMPACT WX...VOLKMER
FORECASTS...WIMMER
86/99
AREA FORECAST DISCUSSION
NWS MIAMI FL
656 PM EST TUE NOV 25 2014
.AVIATION...MVFR CIGS ARE LIKELY TO DEVELOP OVERNIGHT. IFR CIGS
ARE POSSIBLE, BUT LESS CERTAIN. GUIDANCE HAS BEEN TOO AGGRESSIVE
PAST TWO NIGHTS SHOWING IFR TO ONLY NOT OCCUR AT MOST LOCALES.
FOR THIS REASON, WENT WITH PREVAILING MVFR CIGS WITH A SCT005 AND
WILL CLOSELY MONITOR TRENDS.
IMPRESSIVE TROUGH DIGGING INTO THE GULF WITH CONVECTION ALL THE
WAY TO THE YUCATAN. AS THIS SLIDES EAST, THERE IS THE POTENTIAL
FOR A BROKEN LINE OF TSRA TO MOVE THROUGH SOUTH FL. HOWEVER, THE
STORMS IN THE GULF ARE ONLY SLOWLY PROGRESSING EASTWARD AND
POLYGON TIME TRACKING SUGGESTS A LATE NIGHT ARRIVAL AFTER MIDNIGHT
FOR KAPF AND NOT UNTIL DAWN FOR THE EAST COAST. LATEST HRRR RUN
SHOWS NO QPF EAST COAST UNTIL AFTER 10Z. THIS SEEMS REASONABLE
WITH OUR TIMING ANALYSIS, SO HAVE FOLLOWED THIS. IFR OR LIFR
VIS/CIGS ARE POSSIBLE IN ANY HEAVIER TSRA WHICH MOVES THROUGH WITH
IMPACT POTENTIAL HIGHEST FROM 05-09Z AT KAPF AND 09-14Z FOR THE
EAST COAST TERMINALS. GREATEST THREAT KAPF TO KFLL AND POINTS
NORTH. GUST WIND POTENTIAL ~40KT POSSIBLE. ANY SIGNIFICANT IMPACTS
WOULD BE BRIEF THOUGH. THX CWSU MIAMI FOR COLLABORATION! /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 356 PM EST TUE NOV 25 2014/
..A FEW STRONG STORMS POSSIBLE LAKE OKEECHOBEE/WEST COAST TONIGHT...
..ROUGH MARINE CONDITIONS ON WEDNESDAY FOR ALL SOUTH FLORIDA WATERS...
..DRIER AND COOLER WEATHER THIS THANKSGIVING WEEKEND...
SHORT TERM... A MID TO UPPER LEVEL TROUGH OF LOW PRESSURE THAT
EXTENDED FROM THE GREAT LAKES SOUTHWEST INTO THE NORTHWEST GULF OF
MEXICO WILL CONTINUE TO MOVE TO THE EAST TONIGHT AND BE LOCATED OVER
THE EASTERN UNITED STATES BY WEDNESDAY MORNING. THIS WILL PUSH HIGH
PRESSURE OVER THE WESTERN ATLANTIC WATERS FURTHER EASTWARD INTO THE
ATLANTIC. LOW PRESSURE OVER THE EASTERN GULF OF MEXICO WILL THEN
MOVE NORTHEAST ALONG THE STATIONARY FRONT THAT IS LOCATED OVER
CENTRAL FLORIDA.
THIS WEATHER PATTERN WILL ALLOW FOR THE SURFACE WINDS TO BECOME MORE
SOUTHWEST OVER SOUTH FLORIDA TONIGHT BRINGING IN THE TROPICAL
MOISTURE FROM THE GULF OF MEXICO INTO SOUTH FLORIDA.
THEREFORE...POPS WILL BE ON AN INCREASE OVER SOUTH FLORIDA TONIGHT
FROM WEST TO EAST...SCATTERED TO NUMEROUS BY LATE TONIGHT WITH THE
HIGHEST POPS OVER THE LAKE OKEECHOBEE REGION AND WEST COAST METRO
AREAS.
THERE IS ALSO A THREAT OF A FEW STRONG STORMS OVER THE LAKE
OKEECHOBEE AND WEST COAST METRO AREAS LATE THIS AFTERNOON INTO
TONIGHT...AS THE LATEST SHORT RANGE MODELS CONTINUE TO INDICATE A
MID LEVEL JET OF 50 KNOTS MOVING THROUGH CENTRAL FLORIDA TONIGHT
ASSOCIATED WITH THE LOW. THE PRIMARY IMPACTS FROM THE STRONG
STORMS WILL BE FREQUENT LIGHTNING STRIKES...GUSTY WINDS...AND HEAVY
RAINFALL THIS AFTERNOON INTO EARLY THIS EVENING.
THE LOW WILL CONTINUE TO MOVE NORTHEAST UP THE EAST COAST OF THE
UNITED STATES ON WEDNESDAY. THIS WILL ALLOW FOR THE STATIONARY
FRONT TO BECOME A COLD FRONT TONIGHT...AND PUSH SOUTHWARD THROUGH
SOUTH FLORIDA WEDNESDAY MORNING BEFORE MOVING INTO THE FLORIDA
KEYS WEDNESDAY AFTERNOON. THEREFORE...THE POPS WILL REMAIN IN THE
SCATTERED TO NUMEROUS RANGE WEDNESDAY MORNING BEFORE DECREASING IN
COVERAGE WEDNESDAY AFTERNOON.
HIGH PRESSURE WILL THEN BUILD INTO THE SOUTHEASTERN UNITED STATES
WEDNESDAY NIGHT THROUGH FRIDAY KEEPING A NORTHERLY WIND FLOW OVER
SOUTH FLORIDA. THIS NORTHERLY WIND FLOW WILL BRING IN DRIER AND
COOLER WEATHER TO SOUTH FLORIDA FOR THANKSGIVING AND FRIDAY.
LOWS WILL BE IN THE 40S OVER MOST OF SOUTH FLORIDA FOR WEDNESDAY
NIGHT AND THURSDAY NIGHT...EXCEPT FOR LOWER TO MID 50S EAST COAST
METRO AREAS. HIGHS WILL BE IN THE LOWER TO MID 70S FOR THANKSGIVING
DAY AND FOR FRIDAY.
LONG TERM...
THE HIGH WILL THEN MOVE SLOWLY EAST INTO THE WESTERN ATLANTIC
WATERS THIS THANKSGIVING WEEKEND ALLOWING FOR THE WINDS TO SLOWLY
SWING TO A EASTERLY DIRECTION AND BECOME BREEZY. THIS WILL KEEP
SOUTH FLORIDA DRY AND ALLOW FOR THE TEMPERATURES TO SLOWLY WARM UP
THROUGH THE WEEKEND...WITH HIGHS IN THE MID TO UPPER 70S AND LOWS IN
THE 50S EXCEPT 60S EAST COAST METRO AREAS.
MARINE...
THE WINDS WILL SWING FROM A SOUTHERLY DIRECTION OF 10 TO 15 KNOTS TONIGHT
TO A NORTHERLY DIRECTION ON WEDNESDAY AND INCREASE QUICKLY TO 20
TO 25 KNOTS WITH GUSTS GETTING CLOSE TO GALE FORCE IN THE OFFSHORE
GULF WATERS. THE NORTHERLY WINDS WILL CONTINUE WEDNESDAY NIGHT
INTO THANKSGIVING DAY AS THE WIND SPEEDS DECREASE TO 15 TO 20
KNOTS.
BOTH THE ATLANTIC AND GULF SEAS WILL REMAIN BELOW 6 FEET TONIGHT
BEFORE INCREASING TO AT LEAST 7 FEET ON WEDNESDAY. THE OFFSHORE
GULF WATERS COULD EVEN GET UP TO 9 TO 11 FEET ON WEDNESDAY.
THEREFORE...IT LOOKS LIKE AN SCA WILL BE NEEDED SOON FOR ALL OF THE
SOUTH FLORIDA WATERS FOR THE WINDS AND SEAS IN THE ATLANTIC AND GULF
WATERS...FOR WEDNESDAY INTO WEDNESDAY NIGHT.
THE THREAT OF RIP CURRENTS WILL ALSO CONTINUE ALONG THE EAST COAST
BEACHES THIS THANKSGIVING WEEKEND AND FOR THE GULF BEACHES OF
SOUTH FLORIDA FOR WEDNESDAY.
FIRE WEATHER... THE RELATIVE HUMIDITY SHOULD FALL BELOW THE 35
PERCENT CRITICAL VALUE ON THANKSGIVING DAY OVER SOUTH FLORIDA DUE TO
DRIER AIR WORKING INTO THE AREA FROM THE NORTH. HOWEVER...THE ERC
WILL REMAIN IN THE UPPER TEENS TO LOWER 20S AND THE 20 FOOT WINDS
WILL REMAIN BELOW 15 MPH ON THANKSGIVING DAY. THEREFORE...NO FIRE
DANGER STATEMENT WILL BE ISSUED FOR SOUTH FLORIDA FOR THANKSGIVING
DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 72 74 49 73 / 50 70 10 0
FORT LAUDERDALE 74 76 55 75 / 40 60 10 0
MIAMI 74 76 56 76 / 40 50 10 0
NAPLES 66 69 48 73 / 70 70 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1207 PM CST MON NOV 24 2014
.UPDATE...1109 AM CST
NO CHANGES TO GOING WINTER WEATHER ADVISORY. DUAL POL HAS SHOWN
PROGRESSION OF RAIN/SNOW LINE NICELY THIS MORNING AS COLD AIR HAS
WRAPPED IN FROM SOUTHWEST. HAVE OBSERVED SLUSHY ACCUMULATION ON
PAVEMENT HERE AT OFFICE AND ALSO RECEIVING SIMILAR REPORTS VIA
SPOTTERS AND SOCIAL MEDIA. AS SECONDARY DEFORMATION AXIS LIFTS
NORTH...CONDITIONS WILL LIKELY IMPROVE FOR SOUTHWEST CHI METRO TO
DOWNTOWN WITHIN NEXT ONE TO TWO HOURS. MEANWHILE...WORST OF
CONDITIONS WILL SETTLE INTO FAR NORTHERN IL...INCLUDING NORTH AND
NORTHWEST CHICAGO METRO AND ROCKFORD AREA. GIVEN VISIBILITY IN
HEAVIEST PORTION OF BAND DOWN AROUND 1/4 MILES AS OF 11AM...WIND
AND SNOW ACCUMS ON ROADWAY WILL RESULT IN HAZARDOUS TRAVEL AS
TEMPERATURES CONTINUE TO FALL TO AND BELOW FREEZING. IT APPEARS
SOME PORTIONS OF NORTHWEST/NORTH CENTRAL IL HAVE ALREADY RECEIVED
ONE INCH OR SO OF ACCUMULATION...SO STILL LOOKING AT ACCUMULATIONS
GENERALLY IN THE 2 TO 4 INCH RANGE IN THE ADVISORY AREA.
STRONG WESTERLY WINDS ARE AN ISSUE AREA WIDE...BUT PARTICULARLY IN
SOUTH/SOUTHEAST CWA WHERE MAX 3 HR PRESSURE RISES ~8MB ARE
FOCUSING. EXPECT WIND GUSTS TO 40 TO 45 MPH THROUGH EARLY TO MID
AFTERNOON. WILL HOLD OFF ON ISSUING AN ADVISORY...AS EXPECTING
ONLY SPORADIC GUSTS TO 45 MPH.
RC
&&
.SHORT TERM...
313 AM CST
THROUGH TONIGHT...
COMPLEX STORM SYSTEM WILL CONTINUE TO INFLUENCE OUR WEATHER THROUGH
TONIGHT WITH A TRANSITION FROM MILD AND RAINY TOWARD COLD AND
POTENTIALLY SNOWY LIKELY TO TAKE PLACE LATER THIS MORNING.
DEEPENING SURFACE LOW FROM CENTRAL LAKE MICHIGAN EAST INTO LOWER
MICHIGAN WILL CONTINUE TO LIFT NORTHEAST TODAY AND DEEPEN FURTHER.
COLD FRONT TRAILING THIS BROAD LOW IS CROSSING THE MISSISSIPPI RIVER
NOW AND WILL STEADILY MARCH EAST ACROSS OUR CWA THIS MORNING
RESULTING IN STEADILY FALLING TEMPERATURES FROM THE POINT OF FROPA
THROUGH TONIGHT.
THE PRIMARY DEFORMATION ZONE WITH THIS SYSTEM IS MOVING OUT OF THE
AREA AT THIS TIME...HOWEVER THERE ARE A COUPLE ADDITIONAL VORTICITY
MAXIMA UPSTREAM. THE FIRST WELL DEFINED VORT IS NEAR STL WITH A SLUG
OF RAIN AND EVEN A COUPLE OF ISOLATED THUNDERSTORMS. THIS VORT IS
PROGGED TO SHEAR ENE CENTRAL ILLINOIS INTO NORTHERN OHIO TODAY. A
SECOND VORT MAX IS LOCATED UPSTREAM OVER KANSAS AND PIVOTING AROUND
THE BASE OF THE TROUGH AND EVENTUALLY PHASE WITH THE SHEARING OUT
VORT OVER INDIANA AND OHIO THIS AFTERNOON. AS THIS PROCESS TAKES
PLACE...THE RAIN ASSOCIATED WITH VORT ONE WILL SPREAD NORTHEAST
ACROSS OUR CWA THIS MORNING. AS THE SECOND VORT BEGINS TO PHASE WITH
THE FIRST A ZONE OF MID-LEVEL FRONTOGENESIS WILL DEVELOP ACROSS THE
LOWER LAKES THIS AFTERNOON AND ALLOW PRECIP WITH FIRST VORT TO
MAINTAIN ITSELF AND EVEN DEVELOP UPSTREAM (WESTWARD) INTO FAR
NORTHERN ILLINOIS AND ESPECIALLY INTO SOUTHERN WISCONSIN.
GUIDANCE HAS ALL SHIFTED NORTHWARD WITH THIS PROCESS COMPARED WITH
EARLIER RUNS AND ITS DIFFICULT TO FIND ANY MODEL THAT STILL SUPPORTS
THE 3-5" FORECAST TOTALS WE HAVE GOING IN THE ADVISORY AREA. AM VERY
LEARY ABOUT OVER CORRECTING THINGS SO DID A LOT OF FUZZY MATH AND
FUDGING OF GRIDS TO MAINTAIN AMOUNTS IN THE 2-5" RANGE IN THE
ADVISORY AREA...THOUGH SUSPECT MAJORITY OF THE ADVISORY AREA WILL
END UP WITH TOTALS ON THE BOTTOM END OF THE RANGE. SOUTH OF THE
ADVISORY AREA STILL THINK THERE COULD BE A CHANGEOVER TO SNOW BEFORE
THE DEFORMATION AXIS SHIFTS NORTHWARD AND PRECIP TAPER OFF THIS
AFTERNOON. IF CHANGE OVER ISNT FAST ENOUGH THEN COULD END UP WITH
JUST A TRACE OF SNOW...THOUGH FASTER CHANGE OVER AND BRIEF HEAVIER
INTENSITY COULD SUPPORT AMOUNTS AROUND AN INCH. BEFORE THE ENTIRE
CHANNELED VORT MAX TRANSLATES NORTHEAST OUT OF THE AREA COULD SEE
WESTERN EXTENT OF THE AXIS PIVOT BACK SOUTHWARD A BIT THIS AFTERNOON
INTO OUR NORTHWEST CWA...AND THIS WOULD BE NECESSARY TO GET FORECAST
AMOUNTS.
STRONG WESTERLY WINDS DEVELOP THIS MORNING BEHIND THE COLD FRONT AND
WILL CONTINUE INTO THIS EVENING. THE WINDS WILL WHIP AROUND ANY
FALLING SNOW LEADING TO GREATER REDUCTIONS IN VSBY. IN ADDITION...AS
TEMPS CONTINUE TO FALL FARTHER BELOW FREEZING LATER THIS AFTERNOON
SOME OF THE SNOW ON THE GROUND COULD GET BLOWN AROUND AS SNOW LIKELY
BECOMES MORE POWDERY IN NATURE.
IZZI
&&
.LONG TERM...
313 AM CST
TUESDAY ONWARD...
EXPANSIVE STRATUS DECK LIKELY TO BECOME ESTABLISHED OVER THE AREA
TUESDAY AND WHILE LOW LEVEL FLOW WILL BEGIN TO TRANSITION TO
ANTICYCLONIC TUESDAY AFTERNOON AHEAD OF THE NEXT CLIPPER...NOT SURE
HOW MUCH CLEARING THERE WILL BE AS DRY AIR ADVECTION WILL BE WEAK
WITH DIMINISHING FLOW. IN ADDITION...SUBSIDENCE WILL FURTHER SHARPEN
THE INVERSION CLOUDS ARE TRAPPED BENEATH SO HAVE INCREASED SKY COVER
TUESDAY AND NO LONGER SHOW ANY SUBSTANTIAL CLEARING BEFORE THE MID
WEEK CLIPPER COMES ZIPPING DOWN. GIVEN THE ANTICIPATED CLOUD COVER
HAVE GONE WITH SMALLER DIURNAL TEMP SWINGS WITH CLOUDS PROBABLY
KEEPING TEMPS UP A SMIDGE OVER GUIDANCE AT NIGHT AND A BIT LOWER
DURING THE DAY.
SPEAKING OF THE MID WEEK CLIPPER...GUIDANCE REMAINS INCONSISTENT RUN
TO RUN AND MODEL TO MODEL. THERE HAS BEEN A DISTINCT SOUTHWARD SHIFT
IN GUIDANCE WITH THIS SYSTEM WHICH IF IT WERE TO PAN OUT WOULD PLACE
THE ACCUMULATING SNOW OVER MAINLY OUR SOUTHERN CWA AND POTENTIALLY
BYPASS NORTHERN CWA. THIS CLIPPER IS ORIGINATING AS A PIECE OF
ENERGY BREAKING OFF AN UPPER LOW NEAR THE NORTHERN ALEUTIANS AND
SEEING AS IT HADNT EVEN BROKEN OFF THE LOW AND BEEN WELL SAMPLED YET
AM NOT READY TO THROW MY EGGS IN THE MORE SOUTHERLY TRACK BASKET
JUST YET. BY 12Z WEDNESDAY THE GFS ENSEMBLES HAVE SURFACE LOW
POSITIONS RANGING FROM WESTERN WISCONSIN TO NORTHWEST ARKANSAS...SO
NEEDLESS TO SAY FURTHER CHANGES ARE LIKELY THE NEXT SEVERAL GUIDANCE
CYCLES WITH THIS SYSTEM AND IT IS TOO SOON TO WRITE OFF THE THREAT
OF LIGHT ACCUMULATING SNOW ANYWHERE IN OUR CWA.
ANOTHER INTERESTING TWIST IN THE LATEST MEDIUM RANGE GUIDANCE IS
LESS OF A COLD INTRUSION IN THE WAKE OF THIS CLIPPER FOLLOWED BY A
RAPID TRANSITION TO ZONAL FLOW BY FRIDAY AND INTO THE WEEKEND.
GFS...GEM...AND ECMWF ALL TRACK A SFC LOW OF VARYING STRENGTHS
ACROSS THE UPPER GREAT LAKES SATURDAY PLACING OUR AREA IN WHAT WOULD
BE A VERY MILD SOUTHERLY FLOW. THE 00Z ECMWF THERMAL FIELDS WOULD
SUPPORT HIGHS WELL INTO THE 50S BY SATURDAY...BUT OBVIOUSLY DIDN`T
MAKE THAT DRASTIC OF A CHANGE TO THE GOING FORECAST BUT IF MODELS
REMAIN CONSISTENT WITH THIS LATEST TREND THEN A MILD WEEKEND COULD
BE ON TAP FOR THE REGION.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* PATCHY IFR CIGS SLOWLY LIFTING TO LOW END MVFR ARND 20Z.
* MVFR VSBYS WITH LGT SNOW...LIFTING TO VFR AS SNOW BEGINS TO
DIMINISH TO FLURRIES AFT 00Z.
* WEST WINDS 20-24KT WITH GUSTS 30-35KT.
BEACHLER
//DISCUSSION...UPDATED 18Z...
RAIN QUICKLY CHANGED OVER TO ALL SNOW LATE THIS MORNING...WITH A
FEW BANDS OF MODERATE SNOW REDUCING VSBYS TO 1/2SM TEMPORARILY AT
ORD/MDW/RFD. BASED ON RADAR TRENDS THE HEAVIEST PRECIP WAS QUICKLY
LIFTING NORTHEAST OF ORD/MDW...AND SHUD ALLOW VSBYS TO RETURN TO
ABOVE 1SM BY 19Z. CIGS WILL REMAIN ARND IFR CONDS...BUT SHUD
IMPROVE TO LOW END MVFR CONDS SHORTLY AFT THE HEAVIER SNOW ENDS.
THEN MVFR CIGS WILL LIKELY PERSIST THRU THIS EVE UNTIL MUCH DRIER
AIR ARRIVES AND CIGS BEGIN TO SCATTER OUT TO BKN DECK
OVERNIGHT/EARLY TUE. WINDS WILL CONTINUE TO BE GUSTY FROM THE
WEST. SUSTAINED WINDS HAVE REMAINED ARND 20-24KT WITH GUSTS
APPROACHING 34-38KT AT TIMES.
AS THE PRESSURE BEGINS TO INCREASE TONIGHT...WINDS WILL STEADILY
DIMINISH BUT REMAIN WESTERLY THROUGH THE OVERNIGHT HOURS. CURRENT
INDICATIONS ARE THAT SCATTERED FLURRIES WILL CONTINUE UNTIL ARND
MIDNIGHT.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN THE VSBYS IMPROVING ABOVE 1SM ARND 19Z.
* MEDIUM CONFIDENCE IN TIMING OF CIGS LIFTING FROM LOW END MVFR TO
VFR CONDS OVERNIGHT.
* HIGH CONFIDENCE IN THE STEADIER HEAVIER SNOW ENDING BEFORE
20Z...WITH MEDIUM/HIGH CONFIDENCE IN THE ACCUMULATING SNOW
ENDING BY 23Z.
* LOW CONFIDENCE IN PRECISE ENDING TIME OF LGT SNOW/FLURRIES ARND
6Z.
* HIGH CONFIDENCE IN WIND DIR/SPEED/GUSTS FORECAST. MEDIUM/HIGH
CONFIDENCE IN TIMING OF GUSTS ENDING.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR.
WEDNESDAY...SCHC SNOW. OTHERWISE VFR. SOUTHEAST TO EAST WINDS.
THURSDAY...A FEW FLURRIES POSSIBLE...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SSW WINDS.
SATURDAY...VFR. WEST-SOUTHWEST WINDS.
SUNDAY...VFR. NORTH WINDS.
KMD
&&
.MARINE...
154 AM CST
DEEPENING LOW PRESSURE IS PASSING OVER THE LAKE EARLY THIS MORNING
BRINGING A LULL IN WINDS AND WAVES. THE LOW WILL CONTINUE NORTHEAST
INTO SOUTHWEST QUEBEC LATER THIS AFTERNOON THEN REMAIN STEADY AS IT
PUSHES OFFSHORE OVER NOVA SCOTIA. A STRONG SOUTHWEST TO NORTHEAST
ORIENTED PRESSURE GRADIENT WILL REACH THE SOUTH TIP OF THE LAKE BY
15Z...THEN SPREAD OVER THE REMAINDER OF THE LAKE IN THE AFTERNOON.
GALES LOOK SOLID FOR THE SOUTH HALF OF THE THE LAKE...BUT DUE TO A
WEAKENING PRESSURE GRADIENT WITH TIME TODAY AND A MODEST HIGH
BUILDING INTO THE CANADIAN PRARIES AND UPPER MIDWEST...FEEL THAT
WINDS WILL LIKELY PEAK JUST UNDER GALES FOR THE NORTH HALF. A FEW
GALE FORCE GUSTS ARE POSSIBLE...ESPECIALLY LATE AFTERNOON/EARLY
EVENING.
WEAK HIGH PRESSSURE EXTENDING FROM THE NORTH TIP OF LAKE SUPERIOR TO
THE OHIO VALLEY PASSES OVER THE LAKE TUESDAY AFTERNOON. ANOTHER
WEAKENING LOW EMERGING FROM THE CANADIAN ROCKIES WILL PASS JUST
SOUTH OF THE TIP OF LAKE MICHIGAN WITH THE REMNANT INVERTED TROUGH
CLEARING THE LAKE BY THURSDAY MORNING. THIS WILL BE FOLLOWED BY WEAK
HIGH PRESSSURE FOR A FEW DAYS.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012 UNTIL MIDNIGHT TUESDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 3 AM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
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WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1148 AM CST Mon Nov 24 2014
.UPDATE...
ISSUED AT 1045 AM CST MON NOV 24 2014
Updated the forecast to adjust winds and precipitation chances
today. Kept the wind advisory going into the afternoon for eastern
IL but will likely be able to cancel early as very strong and
still deepening 977 mb low pressure over eastern Ontario pulls
ne away from the Great Lakes region. Still getting some sustained
winds 25 to 30 mph with gusts of 35 to 45 mph in our ne counties
late this morning. Light snow north of I-72 is starting to
diminish and expect this trend to continue into this afternoon as
light snow chances diminish to slight chance and flurries. Highs
have already been reached early this morning with current temps
ranging from 30F at Galesburg to 45F at Mount Carmel airport.
Temps to mostly be in the low to mid 30s today and settle into the
upper 30s to near 40F in southeast IL this afternoon.
&&
.SHORT TERM...(Today)
ISSUED AT 329 AM CST MON NOV 24 2014
Several short-term forecast challenges today, as a potent storm
system tracks through the area. Of particular concern are
strong/gusty winds behind a departing frontal boundary and the
potential for a light accumulation of snow across the W/NW KILX
CWA.
08z/2am surface analysis shows cold front extending from southern
Lake Michigan to the Ozarks. An area of low pressure along the
boundary over southeast Missouri is currently enhancing lift and
triggering a few thunderstorms along/south of the I-70 corridor.
This activity will push E/NE into Indiana by dawn. Further west, an
area of precipitation along/behind the front will continue to lift
northward, mainly impacting locations along/west of I-57. As colder
air streams into the region, the rain will gradually mix with and
change to snow by mid-morning. Based on upstream temp falls across
Iowa/Missouri, readings will drop into the middle 30s across the
Illinois River Valley by 12z/6am, then further east to the I-55
corridor by 15z/9am. At the same time, the precip will be pulling
northeastward out of the area, so there appears to be only a narrow
window of opportunity for snow across the W/NW. Will carry likely
to categorical PoPs across the western half of the CWA for rain
changing to snow this morning, with lower rain chances further east
and south across the remainder of the region. Main area of snow
will lift into northern Illinois by midday, with only a few
flurries/snow-showers persisting along/north of I-72 this
afternoon. Total snow accumulation will be limited due to light QPF
and marginally favorable temps. Around 1 inch is expected
along/north of a Canton to Bloomington-Normal line, with trace
amounts as far southeast as a Litchfield to Champaign-Urbana
line.
Other big story today will be the strong winds behind the cold
front. Upstream obs have already shown gusts as high as 30-40mph
and think these will translate eastward across central Illinois this
morning. Main question will be whether there may be a corridor of
enhanced winds approaching Wind Advisory criteria across the E/SE
CWA. Current MSAS analysis shows max 3-hour pressure rises of 6mb
over southern Missouri/northern Arkansas. Both the 00z and 06z runs
of the NAM have shown these rises tracking northeastward and
increasing to around 9mb over southeast Illinois later this
morning. HRRR 10m wind gust graphic also indicates increasing winds
ahead of the pressure change couplet as it moves across the
southeast CWA between 12z and 18z. Given this consistent signal,
think it is prudent to issue a Wind Advisory for locations
along/southeast of a Champaign to Taylorville line. While all of
central Illinois will experience wind gusts of 30 to 35 mph, this
particular area may see higher gusts exceeding 40 mph.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 329 AM CST MON NOV 24 2014
Low pressure will lift into the Great Lakes tonight, taking the bulk
of the precip with it. Wrap around moisture may brush across the
northern CWA, so have included scattered flurries in the forecast
this evening along/north of I-72. Forecast soundings indicate low
clouds will persist tonight and may even be slow to clear on
Tuesday, despite approaching surface ridge axis. Have therefore
slowed the clearing trend, with cloudy skies tonight followed by
decreasing clouds on Tuesday.
Fast-moving clipper system is still on target for mid-week, with
model consensus bringing the system across central Illinois on
Wednesday. This particular track is slightly further south than
previously advertised, so WAA ahead of the wave may not be quite as
pronounced as once thought. Even still, high temperatures will
climb well into the 30s and into the lower 40s across the southeast
CWA. End result will be light snow across the far north from the
Peoria area northward, a mix of light rain/snow across much of the
area, and mainly rain south of I-70. Due to the limited period of
light precip and warm temps, snow accumulations will be minimal.
Once this system passes to the east, another shot of cold air will
arrive for Thursday. After that, signs are still pointing to warmer
conditions by the end of the week, with temps climbing well into the
40s by Saturday. Both the GFS and ECMWF indicate a cold front will
drop through the region Saturday night, so temps will likely drop
back into the upper 30s/lower 40s by Sunday/Monday. Moisture will
be limited, so will maintain a dry FROPA at this time.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1150 AM CST MON NOV 24 2014
Light snow showers and flurries will occur into mid afternoon over
mainly northern TAF sites of PIA and BMI where MVFR vsbys 3-5 miles
to occur at times. Have just flurries further south along I-72 TAF
sites this afternoon with vsbys generally above 5 miles. MVFR overcast
ceilings to continue through tonight with BMI as low as 900 ft at
midday. Strong and deeping 976 mb low pressure near the
Ontario/Quebec province line continue to pull northeast away from
the Great Lakes region as it lifts across Quebec but still have
cyclonic flow over IL through tonight. This will likely keep
broken to overcast low clouds over central IL through tonight and
have ceilings lifting up to VFR during mid/late Tue morning.
Strong WSW winds 17-25 kts and gusts of 28-35 kts early this
afternoon to gradually diminish later this afternoon and evening
reaching speeds of 10-15 kts after 02Z with west winds around 10
kts overnight into Tue morning.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 6 PM CST this evening FOR ILZ044>046-052>057-
061>063-066>068-071>073.
&&
$$
UPDATE...07
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1109 AM CST MON NOV 24 2014
.UPDATE...
1109 AM CST
NO CHANGES TO GOING WINTER WEATHER ADVISORY. DUAL POL HAS SHOWN
PROGRESSION OF RAIN/SNOW LINE NICELY THIS MORNING AS COLD AIR HAS
WRAPPED IN FROM SOUTHWEST. HAVE OBSERVED SLUSHY ACCUMULATION ON
PAVEMENT HERE AT OFFICE AND ALSO RECEIVING SIMILAR REPORTS VIA
SPOTTERS AND SOCIAL MEDIA. AS SECONDARY DEFORMATION AXIS LIFTS
NORTH...CONDITIONS WILL LIKELY IMPROVE FOR SOUTHWEST CHI METRO TO
DOWNTOWN WITHIN NEXT ONE TO TWO HOURS. MEANWHILE...WORST OF
CONDITIONS WILL SETTLE INTO FAR NORTHERN IL...INCLUDING NORTH AND
NORTHWEST CHICAGO METRO AND ROCKFORD AREA. GIVEN VISIBILITY IN
HEAVIEST PORTION OF BAND DOWN AROUND 1/4 MILES AS OF 11AM...WIND
AND SNOW ACCUMS ON ROADWAY WILL RESULT IN HAZARDOUS TRAVEL AS
TEMPERATURES CONTINUE TO FALL TO AND BELOW FREEZING. IT APPEARS
SOME PORTIONS OF NORTHWEST/NORTH CENTRAL IL HAVE ALREADY RECEIVED
ONE INCH OR SO OF ACCUMULATION...SO STILL LOOKING AT ACCUMULATIONS
GENERALLY IN THE 2 TO 4 INCH RANGE IN THE ADVISORY AREA.
STRONG WESTERLY WINDS ARE AN ISSUE AREA WIDE...BUT PARTICULARLY IN
SOUTH/SOUTHEAST CWA WHERE MAX 3 HR PRESSURE RISES ~8MB ARE
FOCUSING. EXPECT WIND GUSTS TO 40 TO 45 MPH THROUGH EARLY TO MID
AFTERNOON. WILL HOLD OFF ON ISSUING AN ADVISORY...AS EXPECTING
ONLY SPORADIC GUSTS TO 45 MPH.
RC
&&
.SHORT TERM...
313 AM CST
THROUGH TONIGHT...
COMPLEX STORM SYSTEM WILL CONTINUE TO INFLUENCE OUR WEATHER THROUGH
TONIGHT WITH A TRANSITION FROM MILD AND RAINY TOWARD COLD AND
POTENTIALLY SNOWY LIKELY TO TAKE PLACE LATER THIS MORNING.
DEEPENING SURFACE LOW FROM CENTRAL LAKE MICHIGAN EAST INTO LOWER
MICHIGAN WILL CONTINUE TO LIFT NORTHEAST TODAY AND DEEPEN FURTHER.
COLD FRONT TRAILING THIS BROAD LOW IS CROSSING THE MISSISSIPPI RIVER
NOW AND WILL STEADILY MARCH EAST ACROSS OUR CWA THIS MORNING
RESULTING IN STEADILY FALLING TEMPERATURES FROM THE POINT OF FROPA
THROUGH TONIGHT.
THE PRIMARY DEFORMATION ZONE WITH THIS SYSTEM IS MOVING OUT OF THE
AREA AT THIS TIME...HOWEVER THERE ARE A COUPLE ADDITIONAL VORTICITY
MAXIMA UPSTREAM. THE FIRST WELL DEFINED VORT IS NEAR STL WITH A SLUG
OF RAIN AND EVEN A COUPLE OF ISOLATED THUNDERSTORMS. THIS VORT IS
PROGGED TO SHEAR ENE CENTRAL ILLINOIS INTO NORTHERN OHIO TODAY. A
SECOND VORT MAX IS LOCATED UPSTREAM OVER KANSAS AND PIVOTING AROUND
THE BASE OF THE TROUGH AND EVENTUALLY PHASE WITH THE SHEARING OUT
VORT OVER INDIANA AND OHIO THIS AFTERNOON. AS THIS PROCESS TAKES
PLACE...THE RAIN ASSOCIATED WITH VORT ONE WILL SPREAD NORTHEAST
ACROSS OUR CWA THIS MORNING. AS THE SECOND VORT BEGINS TO PHASE WITH
THE FIRST A ZONE OF MID-LEVEL FRONTOGENESIS WILL DEVELOP ACROSS THE
LOWER LAKES THIS AFTERNOON AND ALLOW PRECIP WITH FIRST VORT TO
MAINTAIN ITSELF AND EVEN DEVELOP UPSTREAM (WESTWARD) INTO FAR
NORTHERN ILLINOIS AND ESPECIALLY INTO SOUTHERN WISCONSIN.
GUIDANCE HAS ALL SHIFTED NORTHWARD WITH THIS PROCESS COMPARED WITH
EARLIER RUNS AND ITS DIFFICULT TO FIND ANY MODEL THAT STILL SUPPORTS
THE 3-5" FORECAST TOTALS WE HAVE GOING IN THE ADVISORY AREA. AM VERY
LEARY ABOUT OVER CORRECTING THINGS SO DID A LOT OF FUZZY MATH AND
FUDGING OF GRIDS TO MAINTAIN AMOUNTS IN THE 2-5" RANGE IN THE
ADVISORY AREA...THOUGH SUSPECT MAJORITY OF THE ADVISORY AREA WILL
END UP WITH TOTALS ON THE BOTTOM END OF THE RANGE. SOUTH OF THE
ADVISORY AREA STILL THINK THERE COULD BE A CHANGEOVER TO SNOW BEFORE
THE DEFORMATION AXIS SHIFTS NORTHWARD AND PRECIP TAPER OFF THIS
AFTERNOON. IF CHANGE OVER ISNT FAST ENOUGH THEN COULD END UP WITH
JUST A TRACE OF SNOW...THOUGH FASTER CHANGE OVER AND BRIEF HEAVIER
INTENSITY COULD SUPPORT AMOUNTS AROUND AN INCH. BEFORE THE ENTIRE
CHANNELED VORT MAX TRANSLATES NORTHEAST OUT OF THE AREA COULD SEE
WESTERN EXTENT OF THE AXIS PIVOT BACK SOUTHWARD A BIT THIS AFTERNOON
INTO OUR NORTHWEST CWA...AND THIS WOULD BE NECESSARY TO GET FORECAST
AMOUNTS.
STRONG WESTERLY WINDS DEVELOP THIS MORNING BEHIND THE COLD FRONT AND
WILL CONTINUE INTO THIS EVENING. THE WINDS WILL WHIP AROUND ANY
FALLING SNOW LEADING TO GREATER REDUCTIONS IN VSBY. IN ADDITION...AS
TEMPS CONTINUE TO FALL FARTHER BELOW FREEZING LATER THIS AFTERNOON
SOME OF THE SNOW ON THE GROUND COULD GET BLOWN AROUND AS SNOW LIKELY
BECOMES MORE POWDERY IN NATURE.
IZZI
&&
.LONG TERM...
313 AM CST
TUESDAY ONWARD...
EXPANSIVE STRATUS DECK LIKELY TO BECOME ESTABLISHED OVER THE AREA
TUESDAY AND WHILE LOW LEVEL FLOW WILL BEGIN TO TRANSITION TO
ANTICYCLONIC TUESDAY AFTERNOON AHEAD OF THE NEXT CLIPPER...NOT SURE
HOW MUCH CLEARING THERE WILL BE AS DRY AIR ADVECTION WILL BE WEAK
WITH DIMINISHING FLOW. IN ADDITION...SUBSIDENCE WILL FURTHER SHARPEN
THE INVERSION CLOUDS ARE TRAPPED BENEATH SO HAVE INCREASED SKY COVER
TUESDAY AND NO LONGER SHOW ANY SUBSTANTIAL CLEARING BEFORE THE MID
WEEK CLIPPER COMES ZIPPING DOWN. GIVEN THE ANTICIPATED CLOUD COVER
HAVE GONE WITH SMALLER DIURNAL TEMP SWINGS WITH CLOUDS PROBABLY
KEEPING TEMPS UP A SMIDGE OVER GUIDANCE AT NIGHT AND A BIT LOWER
DURING THE DAY.
SPEAKING OF THE MID WEEK CLIPPER...GUIDANCE REMAINS INCONSISTENT RUN
TO RUN AND MODEL TO MODEL. THERE HAS BEEN A DISTINCT SOUTHWARD SHIFT
IN GUIDANCE WITH THIS SYSTEM WHICH IF IT WERE TO PAN OUT WOULD PLACE
THE ACCUMULATING SNOW OVER MAINLY OUR SOUTHERN CWA AND POTENTIALLY
BYPASS NORTHERN CWA. THIS CLIPPER IS ORIGINATING AS A PIECE OF
ENERGY BREAKING OFF AN UPPER LOW NEAR THE NORTHERN ALEUTIANS AND
SEEING AS IT HADNT EVEN BROKEN OFF THE LOW AND BEEN WELL SAMPLED YET
AM NOT READY TO THROW MY EGGS IN THE MORE SOUTHERLY TRACK BASKET
JUST YET. BY 12Z WEDNESDAY THE GFS ENSEMBLES HAVE SURFACE LOW
POSITIONS RANGING FROM WESTERN WISCONSIN TO NORTHWEST ARKANSAS...SO
NEEDLESS TO SAY FURTHER CHANGES ARE LIKELY THE NEXT SEVERAL GUIDANCE
CYCLES WITH THIS SYSTEM AND IT IS TOO SOON TO WRITE OFF THE THREAT
OF LIGHT ACCUMULATING SNOW ANYWHERE IN OUR CWA.
ANOTHER INTERESTING TWIST IN THE LATEST MEDIUM RANGE GUIDANCE IS
LESS OF A COLD INTRUSION IN THE WAKE OF THIS CLIPPER FOLLOWED BY A
RAPID TRANSITION TO ZONAL FLOW BY FRIDAY AND INTO THE WEEKEND.
GFS...GEM...AND ECMWF ALL TRACK A SFC LOW OF VARYING STRENGTHS
ACROSS THE UPPER GREAT LAKES SATURDAY PLACING OUR AREA IN WHAT WOULD
BE A VERY MILD SOUTHERLY FLOW. THE 00Z ECMWF THERMAL FIELDS WOULD
SUPPORT HIGHS WELL INTO THE 50S BY SATURDAY...BUT OBVIOUSLY DIDN`T
MAKE THAT DRASTIC OF A CHANGE TO THE GOING FORECAST BUT IF MODELS
REMAIN CONSISTENT WITH THIS LATEST TREND THEN A MILD WEEKEND COULD
BE ON TAP FOR THE REGION.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* WEST WINDS TO 10 KT WITH GUSTS TO 30 KT WITH A PERIOD OF 35 KT
GUSTS POSSIBLE MIDDAY/EARLY AFTERNOON.
* SOME LIGHT ACCUMULATION POSSIBLE...ESPECIALLY AROUND MIDDAY.
LIGHTER -SHSN CONTINUE INTO THE EVENING WITH SOME ADDITIONAL
LIGHT ACCUMULATIONS.
* PATCHY IFR TRENDING TO MVFR CIGS.
KMD/BEACHLER
//DISCUSSION...UPDATED 12Z...
THE NEXT BATCH OF PRECIPIATION IS FORECAST TO MOVE TSHORTLY WITH INITIAL
PRECIPITATION TYPE AS -RA. EXPECT CIGS TO REMAIN IFR BUT PROBABLY
LIFT SOME AS WEST WINDS BEGIN TO PICK UP WITH LOW PRESSURE MOVING
NORTHEASTWARD WITH -RASN MIX AROUND 15Z AT KRFD AND A FEW HOURS
LATER IN THE CHICAGO AREA...TURNING TO ALL -SN AROUND 18Z OR SO. THE
COLD AIR IS MAKING A GOOD RUN AT THE AREA SO SPED UP THE TIMING TO
TRANSITION TO -SN. MOISTURE WIL BE DECREASING FROM SOUTH TO NORTH
AS THE TRANSITION FROM -RA TO -SN OCCURS...SO SOME UNCERTAINTY AS
TO HOW LONG THE MODERATE SNOW WILL LAST THE HIGHEST LIKELIHOOD
FOR ACCUMS IS WEST AND NORTH OF THE MAIN CHICAGO TERMINALS TOWARD
ROCKFORD...BUT SOME ACCUMS ARE CERTAINLY STILL PLAUSIBLE
EVERYWHERE..ESPECIALLY IN THE 17Z-20Z TIME FRAME BEFORE THE MAIN
BATCH OF PRECIPITATION SHIFTS NORTHWARD. EXPECT IFR IN THE FIRST
SHOT OF SNOW THEN A TRANSITION TO MVFR WITH LIGHTER SNOW THROUGH
THE AFTERNOON. DURING THIS SAME TIME WINDS WILL BE RAMPING UP WITH
GUSTS TO 30 KT LIKELY...AND POSSIBLY GUSTS TO 35 KT FOR A TIME.
AFTERWARDS...WINDS SLOWLY SUBSIDE...AND THEN A FEW SNOW SHOWERS BUT
MOST LIKELY POSSIBLY JUST FLURRIES OVERNIGHT OR EVEN DRY CONDITIONS
WITH MVFR AND BREEZY WEST WINDS.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH CONFIDENCE IN WIND SPEED/DIR/GUSTS.
* HIGH CONFIDENCE IN PRECIP TYPE BEING ALL SNOW BY 18Z.
* HIGH CONFIDENCE ON CIG TRENDS.
KMD/BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR.
WEDNESDAY...SCHC SNOW. OTHERWISE VFR. SOUTHEAST TO EAST WINDS.
THURSDAY...A FEW FLURRIES POSSIBLE...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SSW WINDS.
SATURDAY...VFR. WEST-SOUTHWEST WINDS.
SUNDAY...VFR. NORTH WINDS.
KMD
&&
.MARINE...
154 AM CST
DEEPENING LOW PRESSURE IS PASSING OVER THE LAKE EARLY THIS MORNING
BRINGING A LULL IN WINDS AND WAVES. THE LOW WILL CONTINUE NORTHEAST
INTO SOUTHWEST QUEBEC LATER THIS AFTERNOON THEN REMAIN STEADY AS IT
PUSHES OFFSHORE OVER NOVA SCOTIA. A STRONG SOUTHWEST TO NORTHEAST
ORIENTED PRESSURE GRADIENT WILL REACH THE SOUTH TIP OF THE LAKE BY
15Z...THEN SPREAD OVER THE REMAINDER OF THE LAKE IN THE AFTERNOON.
GALES LOOK SOLID FOR THE SOUTH HALF OF THE THE LAKE...BUT DUE TO A
WEAKENING PRESSURE GRADIENT WITH TIME TODAY AND A MODEST HIGH
BUILDING INTO THE CANADIAN PRARIES AND UPPER MIDWEST...FEEL THAT
WINDS WILL LIKELY PEAK JUST UNDER GALES FOR THE NORTH HALF. A FEW
GALE FORCE GUSTS ARE POSSIBLE...ESPECIALLY LATE AFTERNOON/EARLY
EVENING.
WEAK HIGH PRESSSURE EXTENDING FROM THE NORTH TIP OF LAKE SUPERIOR TO
THE OHIO VALLEY PASSES OVER THE LAKE TUESDAY AFTERNOON. ANOTHER
WEAKENING LOW EMERGING FROM THE CANADIAN ROCKIES WILL PASS JUST
SOUTH OF THE TIP OF LAKE MICHIGAN WITH THE REMNANT INVERTED TROUGH
CLEARING THE LAKE BY THURSDAY MORNING. THIS WILL BE FOLLOWED BY WEAK
HIGH PRESSSURE FOR A FEW DAYS.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012 UNTIL MIDNIGHT TUESDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 3 AM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1046 AM CST Mon Nov 24 2014
.UPDATE...
ISSUED AT 1045 AM CST MON NOV 24 2014
Updated the forecast to adjust winds and precipitation chances
today. Kept the wind advisory going into the afternoon for eastern
IL but will likely be able to cancel early as very strong and
still deepening 977 mb low pressure over eastern Ontario pulls
ne away from the Great Lakes region. Still getting some sustained
winds 25 to 30 mph with gusts of 35 to 45 mph in our ne counties
late this morning. Light snow north of I-72 is starting to
diminish and expect this trend to continue into this afternoon as
light snow chances diminish to slight chance and flurries. Highs
have already been reached early this morning with current temps
ranging from 30F at Galesburg to 45F at Mount Carmel airport.
Temps to mostly be in the low to mid 30s today and settle into the
upper 30s to near 40F in southeast IL this afternoon.
&&
.SHORT TERM...(Today)
ISSUED AT 329 AM CST MON NOV 24 2014
Several short-term forecast challenges today, as a potent storm
system tracks through the area. Of particular concern are
strong/gusty winds behind a departing frontal boundary and the
potential for a light accumulation of snow across the W/NW KILX
CWA.
08z/2am surface analysis shows cold front extending from southern
Lake Michigan to the Ozarks. An area of low pressure along the
boundary over southeast Missouri is currently enhancing lift and
triggering a few thunderstorms along/south of the I-70 corridor.
This activity will push E/NE into Indiana by dawn. Further west, an
area of precipitation along/behind the front will continue to lift
northward, mainly impacting locations along/west of I-57. As colder
air streams into the region, the rain will gradually mix with and
change to snow by mid-morning. Based on upstream temp falls across
Iowa/Missouri, readings will drop into the middle 30s across the
Illinois River Valley by 12z/6am, then further east to the I-55
corridor by 15z/9am. At the same time, the precip will be pulling
northeastward out of the area, so there appears to be only a narrow
window of opportunity for snow across the W/NW. Will carry likely
to categorical PoPs across the western half of the CWA for rain
changing to snow this morning, with lower rain chances further east
and south across the remainder of the region. Main area of snow
will lift into northern Illinois by midday, with only a few
flurries/snow-showers persisting along/north of I-72 this
afternoon. Total snow accumulation will be limited due to light QPF
and marginally favorable temps. Around 1 inch is expected
along/north of a Canton to Bloomington-Normal line, with trace
amounts as far southeast as a Litchfield to Champaign-Urbana
line.
Other big story today will be the strong winds behind the cold
front. Upstream obs have already shown gusts as high as 30-40mph
and think these will translate eastward across central Illinois this
morning. Main question will be whether there may be a corridor of
enhanced winds approaching Wind Advisory criteria across the E/SE
CWA. Current MSAS analysis shows max 3-hour pressure rises of 6mb
over southern Missouri/northern Arkansas. Both the 00z and 06z runs
of the NAM have shown these rises tracking northeastward and
increasing to around 9mb over southeast Illinois later this
morning. HRRR 10m wind gust graphic also indicates increasing winds
ahead of the pressure change couplet as it moves across the
southeast CWA between 12z and 18z. Given this consistent signal,
think it is prudent to issue a Wind Advisory for locations
along/southeast of a Champaign to Taylorville line. While all of
central Illinois will experience wind gusts of 30 to 35 mph, this
particular area may see higher gusts exceeding 40 mph.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 329 AM CST MON NOV 24 2014
Low pressure will lift into the Great Lakes tonight, taking the bulk
of the precip with it. Wrap around moisture may brush across the
northern CWA, so have included scattered flurries in the forecast
this evening along/north of I-72. Forecast soundings indicate low
clouds will persist tonight and may even be slow to clear on
Tuesday, despite approaching surface ridge axis. Have therefore
slowed the clearing trend, with cloudy skies tonight followed by
decreasing clouds on Tuesday.
Fast-moving clipper system is still on target for mid-week, with
model consensus bringing the system across central Illinois on
Wednesday. This particular track is slightly further south than
previously advertised, so WAA ahead of the wave may not be quite as
pronounced as once thought. Even still, high temperatures will
climb well into the 30s and into the lower 40s across the southeast
CWA. End result will be light snow across the far north from the
Peoria area northward, a mix of light rain/snow across much of the
area, and mainly rain south of I-70. Due to the limited period of
light precip and warm temps, snow accumulations will be minimal.
Once this system passes to the east, another shot of cold air will
arrive for Thursday. After that, signs are still pointing to warmer
conditions by the end of the week, with temps climbing well into the
40s by Saturday. Both the GFS and ECMWF indicate a cold front will
drop through the region Saturday night, so temps will likely drop
back into the upper 30s/lower 40s by Sunday/Monday. Moisture will
be limited, so will maintain a dry FROPA at this time.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 534 AM CST MON NOV 24 2014
A strong cold front has surged across the central Illinois
terminals within the past few hours. Strong westerly winds, with
gusts approaching 35-40 kts at times, will linger through the day
before diminishing this evening. The lingering precipitation
wrapping in behind the front will quickly change over to snow this
morning before ending around midday. IFR or low end MVFR conditions
to start the period will climb into or further into the MVFR
category as the snow comes to an end. While it is possible cigs
may improve to VFR tonight, the better odds are that they will
remain in the MVFR category.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 6 PM CST this evening FOR ILZ044>046-052>057-
061>063-066>068-071>073.
&&
$$
UPDATE...07
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Bak
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
808 AM CST MON NOV 24 2014
.SHORT TERM...
313 AM CST
THROUGH TONIGHT...
COMPLEX STORM SYSTEM WILL CONTINUE TO INFLUENCE OUR WEATHER THROUGH
TONIGHT WITH A TRANSITION FROM MILD AND RAINY TOWARD COLD AND
POTENTIALLY SNOWY LIKELY TO TAKE PLACE LATER THIS MORNING.
DEEPENING SURFACE LOW FROM CENTRAL LAKE MICHIGAN EAST INTO LOWER
MICHIGAN WILL CONTINUE TO LIFT NORTHEAST TODAY AND DEEPEN FURTHER.
COLD FRONT TRAILING THIS BROAD LOW IS CROSSING THE MISSISSIPPI RIVER
NOW AND WILL STEADILY MARCH EAST ACROSS OUR CWA THIS MORNING
RESULTING IN STEADILY FALLING TEMPERATURES FROM THE POINT OF FROPA
THROUGH TONIGHT.
THE PRIMARY DEFORMATION ZONE WITH THIS SYSTEM IS MOVING OUT OF THE
AREA AT THIS TIME...HOWEVER THERE ARE A COUPLE ADDITIONAL VORTICITY
MAXIMA UPSTREAM. THE FIRST WELL DEFINED VORT IS NEAR STL WITH A SLUG
OF RAIN AND EVEN A COUPLE OF ISOLATED THUNDERSTORMS. THIS VORT IS
PROGGED TO SHEAR ENE CENTRAL ILLINOIS INTO NORTHERN OHIO TODAY. A
SECOND VORT MAX IS LOCATED UPSTREAM OVER KANSAS AND PIVOTING AROUND
THE BASE OF THE TROUGH AND EVENTUALLY PHASE WITH THE SHEARING OUT
VORT OVER INDIANA AND OHIO THIS AFTERNOON. AS THIS PROCESS TAKES
PLACE...THE RAIN ASSOCIATED WITH VORT ONE WILL SPREAD NORTHEAST
ACROSS OUR CWA THIS MORNING. AS THE SECOND VORT BEGINS TO PHASE WITH
THE FIRST A ZONE OF MID-LEVEL FRONTOGENESIS WILL DEVELOP ACROSS THE
LOWER LAKES THIS AFTERNOON AND ALLOW PRECIP WITH FIRST VORT TO
MAINTAIN ITSELF AND EVEN DEVELOP UPSTREAM (WESTWARD) INTO FAR
NORTHERN ILLINOIS AND ESPECIALLY INTO SOUTHERN WISCONSIN.
GUIDANCE HAS ALL SHIFTED NORTHWARD WITH THIS PROCESS COMPARED WITH
EARLIER RUNS AND ITS DIFFICULT TO FIND ANY MODEL THAT STILL SUPPORTS
THE 3-5" FORECAST TOTALS WE HAVE GOING IN THE ADVISORY AREA. AM VERY
LEARY ABOUT OVER CORRECTING THINGS SO DID A LOT OF FUZZY MATH AND
FUDGING OF GRIDS TO MAINTAIN AMOUNTS IN THE 2-5" RANGE IN THE
ADVISORY AREA...THOUGH SUSPECT MAJORITY OF THE ADVISORY AREA WILL
END UP WITH TOTALS ON THE BOTTOM END OF THE RANGE. SOUTH OF THE
ADVISORY AREA STILL THINK THERE COULD BE A CHANGEOVER TO SNOW BEFORE
THE DEFORMATION AXIS SHIFTS NORTHWARD AND PRECIP TAPER OFF THIS
AFTERNOON. IF CHANGE OVER ISNT FAST ENOUGH THEN COULD END UP WITH
JUST A TRACE OF SNOW...THOUGH FASTER CHANGE OVER AND BRIEF HEAVIER
INTENSITY COULD SUPPORT AMOUNTS AROUND AN INCH. BEFORE THE ENTIRE
CHANNELED VORT MAX TRANSLATES NORTHEAST OUT OF THE AREA COULD SEE
WESTERN EXTENT OF THE AXIS PIVOT BACK SOUTHWARD A BIT THIS AFTERNOON
INTO OUR NORTHWEST CWA...AND THIS WOULD BE NECESSARY TO GET FORECAST
AMOUNTS.
STRONG WESTERLY WINDS DEVELOP THIS MORNING BEHIND THE COLD FRONT AND
WILL CONTINUE INTO THIS EVENING. THE WINDS WILL WHIP AROUND ANY
FALLING SNOW LEADING TO GREATER REDUCTIONS IN VSBY. IN ADDITION...AS
TEMPS CONTINUE TO FALL FARTHER BELOW FREEZING LATER THIS AFTERNOON
SOME OF THE SNOW ON THE GROUND COULD GET BLOWN AROUND AS SNOW LIKELY
BECOMES MORE POWDERY IN NATURE.
IZZI
&&
.LONG TERM...
313 AM CST
TUESDAY ONWARD...
EXPANSIVE STRATUS DECK LIKELY TO BECOME ESTABLISHED OVER THE AREA
TUESDAY AND WHILE LOW LEVEL FLOW WILL BEGIN TO TRANSITION TO
ANTICYCLONIC TUESDAY AFTERNOON AHEAD OF THE NEXT CLIPPER...NOT SURE
HOW MUCH CLEARING THERE WILL BE AS DRY AIR ADVECTION WILL BE WEAK
WITH DIMINISHING FLOW. IN ADDITION...SUBSIDENCE WILL FURTHER SHARPEN
THE INVERSION CLOUDS ARE TRAPPED BENEATH SO HAVE INCREASED SKY COVER
TUESDAY AND NO LONGER SHOW ANY SUBSTANTIAL CLEARING BEFORE THE MID
WEEK CLIPPER COMES ZIPPING DOWN. GIVEN THE ANTICIPATED CLOUD COVER
HAVE GONE WITH SMALLER DIURNAL TEMP SWINGS WITH CLOUDS PROBABLY
KEEPING TEMPS UP A SMIDGE OVER GUIDANCE AT NIGHT AND A BIT LOWER
DURING THE DAY.
SPEAKING OF THE MID WEEK CLIPPER...GUIDANCE REMAINS INCONSISTENT RUN
TO RUN AND MODEL TO MODEL. THERE HAS BEEN A DISTINCT SOUTHWARD SHIFT
IN GUIDANCE WITH THIS SYSTEM WHICH IF IT WERE TO PAN OUT WOULD PLACE
THE ACCUMULATING SNOW OVER MAINLY OUR SOUTHERN CWA AND POTENTIALLY
BYPASS NORTHERN CWA. THIS CLIPPER IS ORIGINATING AS A PIECE OF
ENERGY BREAKING OFF AN UPPER LOW NEAR THE NORTHERN ALEUTIANS AND
SEEING AS IT HADNT EVEN BROKEN OFF THE LOW AND BEEN WELL SAMPLED YET
AM NOT READY TO THROW MY EGGS IN THE MORE SOUTHERLY TRACK BASKET
JUST YET. BY 12Z WEDNESDAY THE GFS ENSEMBLES HAVE SURFACE LOW
POSITIONS RANGING FROM WESTERN WISCONSIN TO NORTHWEST ARKANSAS...SO
NEEDLESS TO SAY FURTHER CHANGES ARE LIKELY THE NEXT SEVERAL GUIDANCE
CYCLES WITH THIS SYSTEM AND IT IS TOO SOON TO WRITE OFF THE THREAT
OF LIGHT ACCUMULATING SNOW ANYWHERE IN OUR CWA.
ANOTHER INTERESTING TWIST IN THE LATEST MEDIUM RANGE GUIDANCE IS
LESS OF A COLD INTRUSION IN THE WAKE OF THIS CLIPPER FOLLOWED BY A
RAPID TRANSITION TO ZONAL FLOW BY FRIDAY AND INTO THE WEEKEND.
GFS...GEM...AND ECMWF ALL TRACK A SFC LOW OF VARYING STRENGTHS
ACROSS THE UPPER GREAT LAKES SATURDAY PLACING OUR AREA IN WHAT WOULD
BE A VERY MILD SOUTHERLY FLOW. THE 00Z ECMWF THERMAL FIELDS WOULD
SUPPORT HIGHS WELL INTO THE 50S BY SATURDAY...BUT OBVIOUSLY DIDN`T
MAKE THAT DRASTIC OF A CHANGE TO THE GOING FORECAST BUT IF MODELS
REMAIN CONSISTENT WITH THIS LATEST TREND THEN A MILD WEEKEND COULD
BE ON TAP FOR THE REGION.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* IFR CIGS PERSIST THROUGH THE COMING HOURS AND MAY LOWER TO 500 FT
AT TIMES.
* STEADIER RAIN RETURNING JUST AFTER DAYBREAK.
* SOUTHWEST WINDS TO 10 KT SHIFT WEST THIS MORNING THEN SOUTHWEST
WITH GUSTS TO 30 KT WITH A PERIOD OF 35 KT GUSTS POSSIBLE
MIDDAY/EARLY AFTERNOON.
* RAIN CHANGES TO SNOW LATE MORNING..SOME LIGHT ACCUMULATION
POSSIBLE...ESPECIALLY AROUND MIDDAY. LIGHTER -SHSN CONTINUE INTO
THE EVENING WITH SOME ADDITIONAL LIGHT ACCUMULATIONS.
* IFR CIGS LIFTING TO MVFR THIS AFTERNOON.
KMD/BEACHLER
//DISCUSSION...UPDATED 12Z...
THE NEXT BATCH OF PRECIPIATION IS FORECAST TO MOVE TSHORTLY WITH INITIAL
PRECIPITATION TYPE AS -RA. EXPECT CIGS TO REMAIN IFR BUT PROBABLY
LIFT SOME AS WEST WINDS BEGIN TO PICK UP WITH LOW PRESSURE MOVING
NORTHEASTWARD WITH -RASN MIX AROUND 15Z AT KRFD AND A FEW HOURS
LATER IN THE CHICAGO AREA...TURNING TO ALL -SN AROUND 18Z OR SO. THE
COLD AIR IS MAKING A GOOD RUN AT THE AREA SO SPED UP THE TIMING TO
TRANSITION TO -SN. MOISTURE WIL BE DECREASING FROM SOUTH TO NORTH
AS THE TRANSITION FROM -RA TO -SN OCCURS...SO SOME UNCERTAINTY AS
TO HOW LONG THE MODERATE SNOW WILL LAST THE HIGHEST LIKELIHOOD
FOR ACCUMS IS WEST AND NORTH OF THE MAIN CHICAGO TERMINALS TOWARD
ROCKFORD...BUT SOME ACCUMS ARE CERTAINLY STILL PLAUSIBLE
EVERYWHERE..ESPECIALLY IN THE 17Z-20Z TIME FRAME BEFORE THE MAIN
BATCH OF PRECIPITATION SHIFTS NORTHWARD. EXPECT IFR IN THE FIRST
SHOT OF SNOW THEN A TRANSITION TO MVFR WITH LIGHTER SNOW THROUGH
THE AFTERNOON. DURING THIS SAME TIME WINDS WILL BE RAMPING UP WITH
GUSTS TO 30 KT LIKELY...AND POSSIBLY GUSTS TO 35 KT FOR A TIME.
AFTERWARDS...WINDS SLOWLY SUBSIDE...AND THEN A FEW SNOW SHOWERS BUT
MOST LIKELY POSSIBLY JUST FLURRIES OVERNIGHT OR EVEN DRY CONDITIONS
WITH MVFR AND BREEZY WEST WINDS.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH IN IFR CONTINUING WITH SOME LOWERING IN MODERATE RAIN THIS
MORNING.
* MEDIUM-HIGH CONFIDENCE IN VSBY HOLDING AT MVFR THOUGH OCCASIONAL
IFR MIXED IN. MVFR/IFR IN FIRST BATCH OF SNOW.
* HIGH CONFIDENCE IN WIND FORECAST MONDAY AND 30+ KT GUSTS. MEDIUM
CONFIDENCE IN SPORADICALLY REACHING 35 KT OR SO.
* HIGH CONFIDENCE IN RAIN CHANGING TO SNOW BUT LOW CONFIDENCE IN
HOW MUCH PRECIP COVERAGE THERE WILL BE THROUGH THE
AFTERNOON/EVENING.
* HIGH CONFIDENCE ON CIG TRENDS...LOW-MEDIUM ON WHEN IFR LIFTS TO
MVFR AND HOW LONG MVFR LASTS.
KMD/BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR.
WEDNESDAY...SCHC SNOW. OTHERWISE VFR. SOUTHEAST TO EAST WINDS.
THURSDAY...A FEW FLURRIES POSSIBLE...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SSW WINDS.
SATURDAY...VFR. WEST-SOUTHWEST WINDS.
SUNDAY...VFR. NORTH WINDS.
KMD
&&
.MARINE...
154 AM CST
DEEPENING LOW PRESSURE IS PASSING OVER THE LAKE EARLY THIS MORNING
BRINGING A LULL IN WINDS AND WAVES. THE LOW WILL CONTINUE NORTHEAST
INTO SOUTHWEST QUEBEC LATER THIS AFTERNOON THEN REMAIN STEADY AS IT
PUSHES OFFSHORE OVER NOVA SCOTIA. A STRONG SOUTHWEST TO NORTHEAST
ORIENTED PRESSURE GRADIENT WILL REACH THE SOUTH TIP OF THE LAKE BY
15Z...THEN SPREAD OVER THE REMAINDER OF THE LAKE IN THE AFTERNOON.
GALES LOOK SOLID FOR THE SOUTH HALF OF THE THE LAKE...BUT DUE TO A
WEAKENING PRESSURE GRADIENT WITH TIME TODAY AND A MODEST HIGH
BUILDING INTO THE CANADIAN PRARIES AND UPPER MIDWEST...FEEL THAT
WINDS WILL LIKELY PEAK JUST UNDER GALES FOR THE NORTH HALF. A FEW
GALE FORCE GUSTS ARE POSSIBLE...ESPECIALLY LATE AFTERNOON/EARLY
EVENING.
WEAK HIGH PRESSSURE EXTENDING FROM THE NORTH TIP OF LAKE SUPERIOR TO
THE OHIO VALLEY PASSES OVER THE LAKE TUESDAY AFTERNOON. ANOTHER
WEAKENING LOW EMERGING FROM THE CANADIAN ROCKIES WILL PASS JUST
SOUTH OF THE TIP OF LAKE MICHIGAN WITH THE REMNANT INVERTED TROUGH
CLEARING THE LAKE BY THURSDAY MORNING. THIS WILL BE FOLLOWED BY WEAK
HIGH PRESSSURE FOR A FEW DAYS.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012 UNTIL MIDNIGHT TUESDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 3 AM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
543 AM CST Mon Nov 24 2014
.SHORT TERM...(Today)
ISSUED AT 329 AM CST MON NOV 24 2014
Several short-term forecast challenges today, as a potent storm
system tracks through the area. Of particular concern are
strong/gusty winds behind a departing frontal boundary and the
potential for a light accumulation of snow across the W/NW KILX
CWA.
08z/2am surface analysis shows cold front extending from southern
Lake Michigan to the Ozarks. An area of low pressure along the
boundary over southeast Missouri is currently enhancing lift and
triggering a few thunderstorms along/south of the I-70 corridor.
This activity will push E/NE into Indiana by dawn. Further west, an
area of precipitation along/behind the front will continue to lift
northward, mainly impacting locations along/west of I-57. As colder
air streams into the region, the rain will gradually mix with and
change to snow by mid-morning. Based on upstream temp falls across
Iowa/Missouri, readings will drop into the middle 30s across the
Illinois River Valley by 12z/6am, then further east to the I-55
corridor by 15z/9am. At the same time, the precip will be pulling
northeastward out of the area, so there appears to be only a narrow
window of opportunity for snow across the W/NW. Will carry likely
to categorical PoPs across the western half of the CWA for rain
changing to snow this morning, with lower rain chances further east
and south across the remainder of the region. Main area of snow
will lift into northern Illinois by midday, with only a few
flurries/snow-showers persisting along/north of I-72 this
afternoon. Total snow accumulation will be limited due to light QPF
and marginally favorable temps. Around 1 inch is expected
along/north of a Canton to Bloomington-Normal line, with trace
amounts as far southeast as a Litchfield to Champaign-Urbana
line.
Other big story today will be the strong winds behind the cold
front. Upstream obs have already shown gusts as high as 30-40mph
and think these will translate eastward across central Illinois this
morning. Main question will be whether there may be a corridor of
enhanced winds approaching Wind Advisory criteria across the E/SE
CWA. Current MSAS analysis shows max 3-hour pressure rises of 6mb
over southern Missouri/northern Arkansas. Both the 00z and 06z runs
of the NAM have shown these rises tracking northeastward and
increasing to around 9mb over southeast Illinois later this
morning. HRRR 10m wind gust graphic also indicates increasing winds
ahead of the pressure change couplet as it moves across the
southeast CWA between 12z and 18z. Given this consistent signal,
think it is prudent to issue a Wind Advisory for locations
along/southeast of a Champaign to Taylorville line. While all of
central Illinois will experience wind gusts of 30 to 35 mph, this
particular area may see higher gusts exceeding 40 mph.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 329 AM CST MON NOV 24 2014
Low pressure will lift into the Great Lakes tonight, taking the bulk
of the precip with it. Wrap around moisture may brush across the
northern CWA, so have included scattered flurries in the forecast
this evening along/north of I-72. Forecast soundings indicate low
clouds will persist tonight and may even be slow to clear on
Tuesday, despite approaching surface ridge axis. Have therefore
slowed the clearing trend, with cloudy skies tonight followed by
decreasing clouds on Tuesday.
Fast-moving clipper system is still on target for mid-week, with
model consensus bringing the system across central Illinois on
Wednesday. This particular track is slightly further south than
previously advertised, so WAA ahead of the wave may not be quite as
pronounced as once thought. Even still, high temperatures will
climb well into the 30s and into the lower 40s across the southeast
CWA. End result will be light snow across the far north from the
Peoria area northward, a mix of light rain/snow across much of the
area, and mainly rain south of I-70. Due to the limited period of
light precip and warm temps, snow accumulations will be minimal.
Once this system passes to the east, another shot of cold air will
arrive for Thursday. After that, signs are still pointing to warmer
conditions by the end of the week, with temps climbing well into the
40s by Saturday. Both the GFS and ECMWF indicate a cold front will
drop through the region Saturday night, so temps will likely drop
back into the upper 30s/lower 40s by Sunday/Monday. Moisture will
be limited, so will maintain a dry FROPA at this time.
&&
.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
ISSUED AT 534 AM CST MON NOV 24 2014
A strong cold front has surged across the central Illinois
terminals within the past few hours. Strong westerly winds, with
gusts approaching 35-40 kts at times, will linger through the day
before diminishing this evening. The lingering precipitation
wrapping in behind the front will quickly change over to snow this
morning before ending around midday. IFR or low end MVFR conditions
to start the period will climb into or further into the MVFR
category as the snow comes to an end. While it is possible cigs
may improve to VFR tonight, the better odds are that they will
remain in the MVFR category.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 6 PM CST this evening FOR ILZ044>046-052>057-
061>063-066>068-071>073.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Bak
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
542 AM CST MON NOV 24 2014
.SHORT TERM...
313 AM CST
THROUGH TONIGHT...
COMPLEX STORM SYSTEM WILL CONTINUE TO INFLUENCE OUR WEATHER THROUGH
TONIGHT WITH A TRANSITION FROM MILD AND RAINY TOWARD COLD AND
POTENTIALLY SNOWY LIKELY TO TAKE PLACE LATER THIS MORNING.
DEEPENING SURFACE LOW FROM CENTRAL LAKE MICHIGAN EAST INTO LOWER
MICHIGAN WILL CONTINUE TO LIFT NORTHEAST TODAY AND DEEPEN FURTHER.
COLD FRONT TRAILING THIS BROAD LOW IS CROSSING THE MISSISSIPPI RIVER
NOW AND WILL STEADILY MARCH EAST ACROSS OUR CWA THIS MORNING
RESULTING IN STEADILY FALLING TEMPERATURES FROM THE POINT OF FROPA
THROUGH TONIGHT.
THE PRIMARY DEFORMATION ZONE WITH THIS SYSTEM IS MOVING OUT OF THE
AREA AT THIS TIME...HOWEVER THERE ARE A COUPLE ADDITIONAL VORTICITY
MAXIMA UPSTREAM. THE FIRST WELL DEFINED VORT IS NEAR STL WITH A SLUG
OF RAIN AND EVEN A COUPLE OF ISOLATED THUNDERSTORMS. THIS VORT IS
PROGGED TO SHEAR ENE CENTRAL ILLINOIS INTO NORTHERN OHIO TODAY. A
SECOND VORT MAX IS LOCATED UPSTREAM OVER KANSAS AND PIVOTING AROUND
THE BASE OF THE TROUGH AND EVENTUALLY PHASE WITH THE SHEARING OUT
VORT OVER INDIANA AND OHIO THIS AFTERNOON. AS THIS PROCESS TAKES
PLACE...THE RAIN ASSOCIATED WITH VORT ONE WILL SPREAD NORTHEAST
ACROSS OUR CWA THIS MORNING. AS THE SECOND VORT BEGINS TO PHASE WITH
THE FIRST A ZONE OF MID-LEVEL FRONTOGENESIS WILL DEVELOP ACROSS THE
LOWER LAKES THIS AFTERNOON AND ALLOW PRECIP WITH FIRST VORT TO
MAINTAIN ITSELF AND EVEN DEVELOP UPSTREAM (WESTWARD) INTO FAR
NORTHERN ILLINOIS AND ESPECIALLY INTO SOUTHERN WISCONSIN.
GUIDANCE HAS ALL SHIFTED NORTHWARD WITH THIS PROCESS COMPARED WITH
EARLIER RUNS AND ITS DIFFICULT TO FIND ANY MODEL THAT STILL SUPPORTS
THE 3-5" FORECAST TOTALS WE HAVE GOING IN THE ADVISORY AREA. AM VERY
LEARY ABOUT OVER CORRECTING THINGS SO DID A LOT OF FUZZY MATH AND
FUDGING OF GRIDS TO MAINTAIN AMOUNTS IN THE 2-5" RANGE IN THE
ADVISORY AREA...THOUGH SUSPECT MAJORITY OF THE ADVISORY AREA WILL
END UP WITH TOTALS ON THE BOTTOM END OF THE RANGE. SOUTH OF THE
ADVISORY AREA STILL THINK THERE COULD BE A CHANGEOVER TO SNOW BEFORE
THE DEFORMATION AXIS SHIFTS NORTHWARD AND PRECIP TAPER OFF THIS
AFTERNOON. IF CHANGE OVER ISNT FAST ENOUGH THEN COULD END UP WITH
JUST A TRACE OF SNOW...THOUGH FASTER CHANGE OVER AND BRIEF HEAVIER
INTENSITY COULD SUPPORT AMOUNTS AROUND AN INCH. BEFORE THE ENTIRE
CHANNELED VORT MAX TRANSLATES NORTHEAST OUT OF THE AREA COULD SEE
WESTERN EXTENT OF THE AXIS PIVOT BACK SOUTHWARD A BIT THIS AFTERNOON
INTO OUR NORTHWEST CWA...AND THIS WOULD BE NECESSARY TO GET FORECAST
AMOUNTS.
STRONG WESTERLY WINDS DEVELOP THIS MORNING BEHIND THE COLD FRONT AND
WILL CONTINUE INTO THIS EVENING. THE WINDS WILL WHIP AROUND ANY
FALLING SNOW LEADING TO GREATER REDUCTIONS IN VSBY. IN ADDITION...AS
TEMPS CONTINUE TO FALL FARTHER BELOW FREEZING LATER THIS AFTERNOON
SOME OF THE SNOW ON THE GROUND COULD GET BLOWN AROUND AS SNOW LIKELY
BECOMES MORE POWDERY IN NATURE.
IZZI
&&
.LONG TERM...
313 AM CST
TUESDAY ONWARD...
EXPANSIVE STRATUS DECK LIKELY TO BECOME ESTABLISHED OVER THE AREA
TUESDAY AND WHILE LOW LEVEL FLOW WILL BEGIN TO TRANSITION TO
ANTICYCLONIC TUESDAY AFTERNOON AHEAD OF THE NEXT CLIPPER...NOT SURE
HOW MUCH CLEARING THERE WILL BE AS DRY AIR ADVECTION WILL BE WEAK
WITH DIMINISHING FLOW. IN ADDITION...SUBSIDENCE WILL FURTHER SHARPEN
THE INVERSION CLOUDS ARE TRAPPED BENEATH SO HAVE INCREASED SKY COVER
TUESDAY AND NO LONGER SHOW ANY SUBSTANTIAL CLEARING BEFORE THE MID
WEEK CLIPPER COMES ZIPPING DOWN. GIVEN THE ANTICIPATED CLOUD COVER
HAVE GONE WITH SMALLER DIURNAL TEMP SWINGS WITH CLOUDS PROBABLY
KEEPING TEMPS UP A SMIDGE OVER GUIDANCE AT NIGHT AND A BIT LOWER
DURING THE DAY.
SPEAKING OF THE MID WEEK CLIPPER...GUIDANCE REMAINS INCONSISTENT RUN
TO RUN AND MODEL TO MODEL. THERE HAS BEEN A DISTINCT SOUTHWARD SHIFT
IN GUIDANCE WITH THIS SYSTEM WHICH IF IT WERE TO PAN OUT WOULD PLACE
THE ACCUMULATING SNOW OVER MAINLY OUR SOUTHERN CWA AND POTENTIALLY
BYPASS NORTHERN CWA. THIS CLIPPER IS ORIGINATING AS A PIECE OF
ENERGY BREAKING OFF AN UPPER LOW NEAR THE NORTHERN ALEUTIANS AND
SEEING AS IT HADNT EVEN BROKEN OFF THE LOW AND BEEN WELL SAMPLED YET
AM NOT READY TO THROW MY EGGS IN THE MORE SOUTHERLY TRACK BASKET
JUST YET. BY 12Z WEDNESDAY THE GFS ENSEMBLES HAVE SURFACE LOW
POSITIONS RANGING FROM WESTERN WISCONSIN TO NORTHWEST ARKANSAS...SO
NEEDLESS TO SAY FURTHER CHANGES ARE LIKELY THE NEXT SEVERAL GUIDANCE
CYCLES WITH THIS SYSTEM AND IT IS TOO SOON TO WRITE OFF THE THREAT
OF LIGHT ACCUMULATING SNOW ANYWHERE IN OUR CWA.
ANOTHER INTERESTING TWIST IN THE LATEST MEDIUM RANGE GUIDANCE IS
LESS OF A COLD INTRUSION IN THE WAKE OF THIS CLIPPER FOLLOWED BY A
RAPID TRANSITION TO ZONAL FLOW BY FRIDAY AND INTO THE WEEKEND.
GFS...GEM...AND ECMWF ALL TRACK A SFC LOW OF VARYING STRENGTHS
ACROSS THE UPPER GREAT LAKES SATURDAY PLACING OUR AREA IN WHAT WOULD
BE A VERY MILD SOUTHERLY FLOW. THE 00Z ECMWF THERMAL FIELDS WOULD
SUPPORT HIGHS WELL INTO THE 50S BY SATURDAY...BUT OBVIOUSLY DIDN`T
MAKE THAT DRASTIC OF A CHANGE TO THE GOING FORECAST BUT IF MODELS
REMAIN CONSISTENT WITH THIS LATEST TREND THEN A MILD WEEKEND COULD
BE ON TAP FOR THE REGION.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* IFR CIGS PERSIST THROUGH THE COMING HOURS AND MAY LOWER TO 500 FT
AT TIMES.
* STEADIER RAIN RETURNING JUST AFTER DAYBREAK.
* SOUTHWEST WINDS TO 10 KT SHIFT WEST THIS MORNING THEN SOUTHWEST
WITH GUSTS TO 30 KT WITH A PERIOD OF 35 KT GUSTS POSSIBLE
MIDDAY/EARLY AFTERNOON.
* RAIN CHANGES TO SNOW LATE MORNING..SOME LIGHT ACCUMULATION
POSSIBLE...ESPECIALLY AROUND MIDDAY. LIGHTER -SHSN CONTINUE INTO
THE EVENING WITH SOME ADDITIONAL LIGHT ACCUMULATIONS.
* IFR CIGS LIFTING TO MVFR THIS AFTERNOON.
KMD
//DISCUSSION...UPDATED 12Z...
THE NEXT BATCH OF PRECIPIATION IS FORECAST TO MOVE TSHORTLY WITH INITIAL
PRECIPITATION TYPE AS -RA. EXPECT CIGS TO REMAIN IFR BUT PROBABLY
LIFT SOME AS WEST WINDS BEGIN TO PICK UP WITH LOW PRESSURE MOVING
NORTHEASTWARD WITH -RASN MIX AROUND 15Z AT KRFD AND A FEW HOURS
LATER IN THE CHICAGO AREA...TURNING TO ALL -SN AROUND 18Z OR SO. THE
COLD AIR IS MAKING A GOOD RUN AT THE AREA SO SPED UP THE TIMING TO
TRANSITION TO -SN. MOISTURE WIL BE DECREASING FROM SOUTH TO NORTH
AS THE TRANSITION FROM -RA TO -SN OCCURS...SO SOME UNCERTAINTY AS
TO HOW LONG THE MODERATE SNOW WILL LAST THE HIGHEST LIKELIHOOD
FOR ACCUMS IS WEST AND NORTH OF THE MAIN CHICAGO TERMINALS TOWARD
ROCKFORD...BUT SOME ACCUMS ARE CERTAINLY STILL PLAUSIBLE
EVERYWHERE..ESPECIALLY IN THE 17Z-20Z TIME FRAME BEFORE THE MAIN
BATCH OF PRECIPITATION SHIFTS NORTHWARD. EXPECT IFR IN THE FIRST
SHOT OF SNOW THEN A TRANSITION TO MVFR WITH LIGHTER SNOW THROUGH
THE AFTERNOON. DURING THIS SAME TIME WINDS WILL BE RAMPING UP WITH
GUSTS TO 30 KT LIKELY...AND POSSIBLY GUSTS TO 35 KT FOR A TIME.
AFTERWARDS...WINDS SLOWLY SUBSIDE...AND THEN A FEW SNOW SHOWERS BUT
MOST LIKELY POSSIBLY JUST FLURRIES OVERNIGHT OR EVEN DRY CONDITIONS
WITH MVFR AND BREEZY WEST WINDS.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH IN IFR CONTINUING WITH SOME LOWERING IN MODERATE RAIN THIS
MORNING.
* MEDIUM-HIGH CONFIDENCE IN VSBY HOLDING AT MVFR THOUGH OCCASIONAL
IFR MIXED IN. MVFR/IFR IN FIRST BATCH OF SNOW.
* HIGH CONFIDENCE IN WIND FORECAST MONDAY AND 30+ KT GUSTS. MEDIUM
CONFIDENCE IN SPORADICALLY REACHING 35 KT OR SO.
* HIGH CONFIDENCE IN RAIN CHANGING TO SNOW BUT LOW CONFIDENCE IN
HOW MUCH PRECIP COVERAGE THERE WILL BE THROUGH THE
AFTERNOON/EVENING.
* HIGH CONFIDENCE ON CIG TRENDS...LOW-MEDIUM ON WHEN IFR LIFTS TO
MVFR AND HOW LONG MVFR LASTS.
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...VFR.
WEDNESDAY...SCHC SNOW. OTHERWISE VFR. SOUTHEAST TO EAST WINDS.
THURSDAY...A FEW FLURRIES POSSIBLE...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SSW WINDS.
SATURDAY...VFR. WEST-SOUTHWEST WINDS.
SUNDAY...VFR. NORTH WINDS.
KMD
&&
.MARINE...
154 AM CST
DEEPENING LOW PRESSURE IS PASSING OVER THE LAKE EARLY THIS MORNING
BRINGING A LULL IN WINDS AND WAVES. THE LOW WILL CONTINUE NORTHEAST
INTO SOUTHWEST QUEBEC LATER THIS AFTERNOON THEN REMAIN STEADY AS IT
PUSHES OFFSHORE OVER NOVA SCOTIA. A STRONG SOUTHWEST TO NORTHEAST
ORIENTED PRESSURE GRADIENT WILL REACH THE SOUTH TIP OF THE LAKE BY
15Z...THEN SPREAD OVER THE REMAINDER OF THE LAKE IN THE AFTERNOON.
GALES LOOK SOLID FOR THE SOUTH HALF OF THE THE LAKE...BUT DUE TO A
WEAKENING PRESSURE GRADIENT WITH TIME TODAY AND A MODEST HIGH
BUILDING INTO THE CANADIAN PRARIES AND UPPER MIDWEST...FEEL THAT
WINDS WILL LIKELY PEAK JUST UNDER GALES FOR THE NORTH HALF. A FEW
GALE FORCE GUSTS ARE POSSIBLE...ESPECIALLY LATE AFTERNOON/EARLY
EVENING.
WEAK HIGH PRESSSURE EXTENDING FROM THE NORTH TIP OF LAKE SUPERIOR TO
THE OHIO VALLEY PASSES OVER THE LAKE TUESDAY AFTERNOON. ANOTHER
WEAKENING LOW EMERGING FROM THE CANADIAN ROCKIES WILL PASS JUST
SOUTH OF THE TIP OF LAKE MICHIGAN WITH THE REMNANT INVERTED TROUGH
CLEARING THE LAKE BY THURSDAY MORNING. THIS WILL BE FOLLOWED BY WEAK
HIGH PRESSSURE FOR A FEW DAYS.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012...9 AM MONDAY TO MIDNIGHT TUESDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 AM MONDAY TO 3 AM TUESDAY.
&&
$$
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
329 AM CST Mon Nov 24 2014
.SHORT TERM...(Today)
ISSUED AT 329 AM CST MON NOV 24 2014
Several short-term forecast challenges today, as a potent storm
system tracks through the area. Of particular concern are
strong/gusty winds behind a departing frontal boundary and the
potential for a light accumulation of snow across the W/NW KILX
CWA.
08z/2am surface analysis shows cold front extending from southern
Lake Michigan to the Ozarks. An area of low pressure along the
boundary over southeast Missouri is currently enhancing lift and
triggering a few thunderstorms along/south of the I-70 corridor.
This activity will push E/NE into Indiana by dawn. Further west, an
area of precipitation along/behind the front will continue to lift
northward, mainly impacting locations along/west of I-57. As colder
air streams into the region, the rain will gradually mix with and
change to snow by mid-morning. Based on upstream temp falls across
Iowa/Missouri, readings will drop into the middle 30s across the
Illinois River Valley by 12z/6am, then further east to the I-55
corridor by 15z/9am. At the same time, the precip will be pulling
northeastward out of the area, so there appears to be only a narrow
window of opportunity for snow across the W/NW. Will carry likely
to categorical PoPs across the western half of the CWA for rain
changing to snow this morning, with lower rain chances further east
and south across the remainder of the region. Main area of snow
will lift into northern Illinois by midday, with only a few
flurries/snow-showers persisting along/north of I-72 this
afternoon. Total snow accumulation will be limited due to light QPF
and marginally favorable temps. Around 1 inch is expected
along/north of a Canton to Bloomington-Normal line, with trace
amounts as far southeast as a Litchfield to Champaign-Urbana
line.
Other big story today will be the strong winds behind the cold
front. Upstream obs have already shown gusts as high as 30-40mph
and think these will translate eastward across central Illinois this
morning. Main question will be whether there may be a corridor of
enhanced winds approaching Wind Advisory criteria across the E/SE
CWA. Current MSAS analysis shows max 3-hour pressure rises of 6mb
over southern Missouri/northern Arkansas. Both the 00z and 06z runs
of the NAM have shown these rises tracking northeastward and
increasing to around 9mb over southeast Illinois later this
morning. HRRR 10m wind gust graphic also indicates increasing winds
ahead of the pressure change couplet as it moves across the
southeast CWA between 12z and 18z. Given this consistent signal,
think it is prudent to issue a Wind Advisory for locations
along/southeast of a Champaign to Taylorville line. While all of
central Illinois will experience wind gusts of 30 to 35 mph, this
particular area may see higher gusts exceeding 40 mph.
&&
.LONG TERM...(Tonight through Sunday)
ISSUED AT 329 AM CST MON NOV 24 2014
Low pressure will lift into the Great Lakes tonight, taking the bulk
of the precip with it. Wrap around moisture may brush across the
northern CWA, so have included scattered flurries in the forecast
this evening along/north of I-72. Forecast soundings indicate low
clouds will persist tonight and may even be slow to clear on
Tuesday, despite approaching surface ridge axis. Have therefore
slowed the clearing trend, with cloudy skies tonight followed by
decreasing clouds on Tuesday.
Fast-moving clipper system is still on target for mid-week, with
model consensus bringing the system across central Illinois on
Wednesday. This particular track is slightly further south than
previously advertised, so WAA ahead of the wave may not be quite as
pronounced as once thought. Even still, high temperatures will
climb well into the 30s and into the lower 40s across the southeast
CWA. End result will be light snow across the far north from the
Peoria area northward, a mix of light rain/snow across much of the
area, and mainly rain south of I-70. Due to the limited period of
light precip and warm temps, snow accumulations will be minimal.
Once this system passes to the east, another shot of cold air will
arrive for Thursday. After that, signs are still pointing to warmer
conditions by the end of the week, with temps climbing well into the
40s by Saturday. Both the GFS and ECMWF indicate a cold front will
drop through the region Saturday night, so temps will likely drop
back into the upper 30s/lower 40s by Sunday/Monday. Moisture will
be limited, so will maintain a dry FROPA at this time.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1147 PM CST SUN NOV 23 2014
The pair of surface low centers have merged and lifted to the NE
of our forecast area, with a trailing cold front to the SW across
IL into southeast Missouri. Drizzle, fog and low clouds are
lingering behind the departing low along that trough, with VLIFR
ceilings at BMI, and LIFR ceilings at the remaining TAF sites.
Expect ceilings to improve slightly with the return redevelopment
of showers well behind the low, but remaining LIFR until Monday
afternoon when levels possibly climb all the way to MVFR.
Cold air will filter into central IL late tonight and Monday
morning, causing the rain showers to mix with or change to light
snow from west to east toward 6 am for PIA/SPI, 8 am for BMI, and
10 am for CMI/DEC. As the precipitation becomes all snow, vsbys
could drop below 1 mile at PIA and BMI where snowfall accumulation
could climb up as high as 1 inch. Vsbys should remain 2-4 miles
farther south toward I-72 where snowfall will be lighter. Snowfall
rates will diminish quickly after 18z-19z, with high winds blowing
any snow around and possibly keeping visibility low at times.
Winds have already become SW behind the low. Pressure rises will
climb to 6 mb/3 hours in at least the southeast half of our
forecast area, which would include DEC/CMI. Wind speeds in our
southeast areas could climb as high as 30g40kt between 12z and 15z
this morning, with other areas 25g35kt. Those speeds could
continue into early afternoon, but we should see some decrease in
peak gusts as the afternoon progresses.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until 6 PM CST this evening FOR ILZ044>046-052>057-
061>063-066>068-071>073.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
155 AM CST MON NOV 24 2014
.UPDATE...
FOR EVENING UPDATE...
ONLY MINOR ADJUSTMENTS MADE TO GOING FORECAST TONIGHT...PRIMARILY
TO ADD AREAS OF FOG ALONG THE LAKE AND ACROSS PARTS OF NORTHERN
ILLINOIS OVERNIGHT.
COMPLEX UPPER PATTERN CONTINUES TO EVOLVE ACROSS THE REGION THIS
EVENING AS A SERIES OF MID-LEVEL SHORT WAVES ROTATE THROUGH THE
LARGER-SCALE UPPER TROUGH OVER THE CENTRAL AND EASTERN PARTS OF
NORTH AMERICA. AT THE SURFACE...AN AREA OF LOW PRESSURE WITH A
COUPLE OF INDIVIDUAL LOW CENTERS WAS OVER IL AT 02Z/8 PM CST...
WITH STRONG (6 MB/3 HRS) SURFACE PRESSURE FALLS ACROSS MUCH OF THE
MIDWEST AND SOUTHERN GREAT LAKES REGION. THE LATEST MODEL GUIDANCE
CONTINUES TO CONSOLIDATE A SURFACE LOW OVER FAR NORTHEAST IL OVER
THE NEXT SEVERAL HOURS...LIFTING IT NORTHEAST AND DEEPENING IT
OVERNIGHT AND EARLY MONDAY AS IT PULLS AWAY FROM THE AREA.
REGIONAL RADAR MOSAICS INDICATE A LARGE SHIELD OF RAIN ACROSS THE
EASTERN HALF OF ILLINOIS AND MUCH OF THE GREAT LAKES REGION
PRIMARILY ASSOCIATED WITH A STRONG SHORT WAVE LIFTING NORTHEAST
CROSS THE OHIO VALLEY. ANOTHER AREA OF RAIN AND EMBEDDED THUNDER
WS NOTED BACK ACROSS THE LOWER MISSOURI VALLEY WITH ANOTHER STRONG
WAVE. RAIN MAY TAPER OFF TO OCCASIONAL LIGHT RAIN OR DRIZZLE
ACROSS SOME AREAS WITH A BIT OF A BREAK BETWEEN THE SOLID RAIN
WITH THESE SYSTEMS...THOUGH A PERSISTENT DRIZZLE WILL LIKELY MAKE
IT SEEM LIKE ITS RAINING MOST OF THE TIME ANYWAYS. IN ADDITION TO
THE RAIN...HIGH DEWPOINT AIR WRAPPING NORTHWESTWARD AHEAD OF THE
SURFACE LOW WAS PRODUCING FOG ACROSS SOUTHERN LAKE MICHIGAN WHERE
LAKE WATER TEMPS WERE IN THE MID-40S...AND AFFECTING AREAS ALONG
THE ILLINOIS SHORE. WILL ALSO LIKELY SEE SOME PATCHES OF FOG WHERE
PRECIP DIMINISHES TO DRIZZLE OVERNIGHT...ESPECIALLY IN BAGGY
PRESSURE GRADIENT AND WEAKER WINDS IN VICINITY OF THE SURFACE LOW.
WEST WINDS WILL KICK IN EARLY MONDAY MORNING AS THE LOW PULLS
NORTH AND A COLD FRONT PUSHES EAST ACROSS THE AREA. THIS SHOULD
HELP PUSH SOME OF THE FOG OUT EARLY IN THE MORNING. COLDER AIR AND
WIND GUSTS TO 40 MPH BECOME AN ISSUE DURING THE DAY...ALONG WITH
PRECIPITATION CHANGE FROM LIQUID TO FROZEN AS THE COLUMN COOLS.
POTENTIAL FOR A PERIOD OF MODERATE/LOCALLY HEAVY WET SNOW EXISTS
OVER NORTH CENTRAL/PARTS OF NORTHEAST IL WHERE SOUTHERN PERIPHERY
OF DEFORMATION BAND PASSES. CONFIDENCE NOT SUPER HIGH WITH AMOUNTS
AT THIS POINT...THOUGH NO CHANGES TO WSW HEADLINES AT THIS TIME.
RATZER
&&
.SHORT TERM...
244 PM CST
UNSEASONABLY WARM/MOIST AIRMASS CONTINUES TO ADVECT NORTH ACROSS THE
REGION THIS AFTN...AND LOOKS TO CONTINUE THROUGH TONIGHT. THE MAIN
CONCERN FOR THE OVERNIGHT WILL BE ON RAINFALL TOTALS AND IF THIS
WILL POSE ANY HYDRO CONCERNS.
STRONG WARM AIR ADVECTION THIS AFTERNOON HAS ALLOWED SFC TEMPS TO
WARM INTO THE 50S ACROSS MUCH OF THE FORECAST AREA WITH DEW POINTS
APPROACHING THE UPPER 40S/ARND 50. THE AXIS OF THE HEAVIER RAINFALL
THIS AFTN HAS SHIFTED TO THE NORTHWEST AND STRETCHES FROM CENTRAL
WISC SOUTHWEST THROUGH FAR EASTERN IOWA. HAVE NUDGED TEMPS OVERNIGHT
UP A TAD...AND EXPECT TEMPS TO REMAIN NEARLY CONSISTENT UNTIL CLOSER
TO DAYBREAK MON WHEN THE FRONTAL BOUNDARY BEGINS TO APPROACH THE
NORTHWEST CWFA. GUIDANCE CONTINUES TO SUGGEST THE LOW DROPPING
SOUTHEAST ACROSS THE UPPER MIDWEST AND THE SECONDARY ONE LIFTING
NORTH FROM THE SOUTHWEST...WILL CONVERGE ACROSS SOUTHWEST LOWER
MICHIGAN JUST BEFORE DAYBREAK MON. THE COLD FRONT WILL BE NEARING
THE WESTERN CWFA ARND DAYBREAK...AND STEADILY SLIDE EAST THRU THE
MORNING. ASSOCIATED WILL BE A SHARP THERMAL TROUGH THAT WILL CAUSE
TEMPS TO STEADILY FALL THROUGHOUT THE MORNING/AFTN. SO THE DAY MAY
START MILD...BUT BY MIDDAY THAT WILL CERTAINLY NOT BE THE CASE WITH
TEMPS GENERALLY IN THE UPR 20S/LOW 30S. PRECIP WILL BE QUICKLY
TRANSITIONING OVER FROM RAIN TO SNOW.
AS THE SNOW BEGINS MIDDAY ACROSS THE NORTHWEST...GUIDANCE HAS BEEN
RELATIVELY CONSISTENT THAT AT ONSET RATIOS WILL HOVER ARND 8:1 TO
9:1...THEN AS THE COLDER AIR ADVECTS IN THOSE RATIOS SHUD STEADILY
CLIMB TO 14:1-17:1 BY LATE MON AFTN/EARLY EVE. COMPOUNDING THE SETUP
WILL BE STEADILY INCREASING PRESSURE GRADIENT THAT WILL CREATE GUSTY
WINDS NEARING 30-35MPH. THERE IS A NARROW WINDOW WHERE SNOWFALL
RATES COULD NEAR 1-2"/HR FOR A COUPLE HOURS...MAINLY BETWEEN 2-4PM
CST AND MAINLY WEST OF A LASALLE TO CRYSTAL LAKE LINE. HAVE BUMPED
SNOW TOTALS UP TO 2-4" AND COULD SEE IN PORTIONS OF WINNEBAGO COUNTY
3-5" CLOSER TO THE WISC STATELINE IN NORTHERN WINNEBAGO COUNTY.
ELSEWHERE SNOW WILL BEGIN TO ACCUMULATE...BUT EXPECTING MUCH LESS
WITH PERHAPS AN INCH IN CHICAGO AND LESSER TOTALS FURTHER SOUTH.
500MB TROUGH AXIS PIVOTS OVERHEAD MON EVE...AND WILL SLOWLY BRING AN
END TO THE ACCUMULATING SNOW. THE BETTER MOISTURE WILL QUICKLY PEEL
OFF TO THE NORTHEAST LATE MON NGT...HOWEVER ENOUGH OMEGA/MOISTURE TO
KEEP MENTION OF LGT SNOW SHOWERS MON NGT.
OVERNIGHT LOWS MON DIP FALL TO THE LOW 20S TO MID 20S IN THE
SOUTHEAST.
BEACHLER
&&
.LONG TERM...
244 PM CST
TUESDAY THROUGH WEDNESDAY...
LARGE MID-LVL TROUGH WILL BE IN PLACE TUE/WED WITH A WEAK SFC RIDGE
LIFTING NORTH AND BRINGING A GRADUAL EROSION TO THE CLOUDS TUE
NGT/WED. UNFORTUNATELY THIS MAY BE SHORT LIVED AS GUIDANCE SUGGESTS
A QUICK SHORTWAVE WILL DROP SOUTH FROM CENTRAL CANADA INTO THE
NORTHERN PLAINS EARLY WED...AND APPROACH THE FORECAST AREA MIDDAY
WED. THIS SYSTEM COULD BRING ANOTHER PERIOD OF LIGHT SNOW WITH SOME
MINOR ACCUMULATIONS.
TEMPS TUE WILL REMAIN IN THE 20S...HOWEVER WITH SOME THINNING IN THE
CLOUDS FOR WED TEMPS COULD REBOUND INTO THE LOW/MID 30S. BUT IT WILL
HINGE UPON THE ARRIVAL OF THE NEXT MID-LVL WAVE AND CLOUD COVER.
THURSDAY THROUGH SATURDAY...
ENSEMBLES IN THE LONGER TERM CONTINUES TO POINT TOWARDS A TROUGH
CARVED OUT ACROSS THE GREAT LAKES/TENN VALLEY FOR THE SECOND HALF OF
THE WEEK...AND THEN BEGINS TO FLATTEN FOR THE SECOND HALF OF THE
WEEKEND. AT THIS TIME GUIDANCE SUGGESTS DRY AIR AND A SFC RIDGE
OVERHEAD FOR THANKSGIVING DAY. TEMPS WILL GENERALLY BE IN THE 20S
FOR THE BULK OF THE EXTENDED.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* IFR CIGS PERSIST THROUGH THE NIGHT AND MAY LOWER TO 300-400 FT.
* STEADY RAIN TURNS TO DRIZZLE OVERNIGHT WITH STEADIER RAIN
RETURNING AFTER DAYBREAK/MID MORNING.
* IFR VSBY LIKELY OVERNIGHT WITH OCCASIONAL VSBY BELOW 3/4SM.
HIGHER LIKELIHOOD FOR ORD THAN MDW.
* LIGHT/VARIABLE WINDS OVERNIGHT SHIFT WEST MONDAY MORNING THEN
SOUTHWEST WITH GUSTS TO 30 KT WITH A PERIOD OF 35 KT GUSTS
POSSIBLE MIDDAY/EARLY AFTERNOON.
* RAIN CHANGES TO SNOW MIDDAY/EARLY AFTERNOON...SOME LIGHT
ACCUMULATION POSSIBLE...ESPECIALLY LATER IN THE DAY.
* IFR CIGS LIFTING TO MVFR LATE THIS AFTERNOON
KMD
//DISCUSSION...UPDATED 06Z...
BAND OF LIGHT/OCCASIONALLY MODERATE RAIN IS LIFTING NORTHWEST
THROUGH THE TERMINALS EARLY THIS MORNING WITH WIDEPREAD IFR CIGS
AND LARGELY IFR/LIFR VSBYS WITH A SMALL CORRIDOR IN THE SOUTHWEST
FROM KIIK TO KMDW SOUTHEASTWARD. EXPECT VSBYS TO DROP ACROSS THE
AREA AS THE FIRST ROUND OF RAIN DISSIPATES SOME AND LIGHTER WINDS
CONTINUE.
THE NEXT BATCH OF PRECIPIATION IS FORECAST TO MOVE THROUGH JUST
AFTER DAYBREAK WITH INITIAL PRECIPITATION TYPE AS -RA. EXPECT CIGS
TO REMAIN IFR BUT PROBABLY LIFT SOME AS WEST WINDS BEGIN TO PICK
UP WITH LOW PRESSURE MOVING NORTHEASTWARD WITH -RASN MIX AROUND
15Z AT KRFD AND A FEW HOURS LATER IN THE CHICAGO AREA...TURNING TO
ALL -SN. MOISTURE WIL BE DECREASING FROM SOUTH TO NORTH AS THE
TRANSITION FROM -RA TO -SN OCCURS. THE HIGHEST LIKELIHOOD FOR
ACCUMS IS WEST OF THE MAIN CHICAGO TERMINALS TOWARD ROCKFORD...BUT
SOME ACCUMS ARE CERTAINLY STILL PLAUSIBLE EVERYWHERE. LOOKS LIKE A
MIX OF SNOW SHOWERS OR POSSIBLY MORE FLURRIES OVERNIGHT WITH AN
IFR TRANSITION TO MVFR.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH IN IFR CONTINUING WITH SOME LOWERING OVERNIGHT.
* HIGH CONFIDENCE IN STEADIER RAIN DIMINISHING TO DRIZZLE
OVERNIGHT WITH STEADIER RAIN RETURNING AFTER DAYBREAK/MID
MORNING.
* MEDIUM-HIGH CONFIDENCE IN VSBY FALLING TO IFR OVERNIGHT. LOW-
MEDIUM CONFIDENCE IN POTENTIAL TO GO BELOW 1SM...HIGHER
CONFIDENCE FOR ORD.
* HIGH CONFIDENCE IN WIND TRENDS TONIGHT BUT MEDIUM CONFIDENCE IN
DIRECTION/SPEED DETAILS.
* HIGH CONFIDENCE IN WIND FORECAST MONDAY AND 30+ KT GUSTS. MEDIUM
CONFIDENCE IN SPORADICALLY REACHING 35 KT OR SO.
* HIGH CONFIDENCE IN RAIN CHANGING TO SNOW BUT LOW CONFIDENCE IN
HOW MUCH PRECIP COVERAGE THERE WILL BE THROUGH THE
AFTERNOON/EVENING.
* HIGH CONFIDENCE ON CIG TRENDS...LOW-MEDIUM ON WHEN IFR LIFTS TO
MVFR AND HOW LONG MVFR LASTS.
KMD
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...MVFR CIGS POSSIBLE WITH A FEW FLURRIES IN THE MORNING.
WEST WINDS.
WEDNESDAY...CHANCE OF SNOW. MVFR/IFR PSBL. SSE WINDS TURNING WEST.
THURSDAY...SCHC SNOW...OTHERWISE VFR. BREEZY NORTHWEST WINDS.
FRIDAY...SCHC SNOW. SSW WINDS.
SATURDAY...VFR. WEST WINDS.
MDB
&&
.MARINE...
154 AM CST
DEEPENING LOW PRESSURE IS PASSING OVER THE LAKE EARLY THIS MORNING
BRINGING A LULL IN WINDS AND WAVES. THE LOW WILL CONTINUE NORTHEAST
INTO SOUTHWEST QUEBEC LATER THIS AFTERNOON THEN REMAIN STEADY AS IT
PUSHES OFFSHORE OVER NOVA SCOTIA. A STRONG SOUTHWEST TO NORTHEAST
ORIENTED PRESSURE GRADIENT WILL REACH THE SOUTH TIP OF THE LAKE BY
15Z...THEN SPREAD OVER THE REMAINDER OF THE LAKE IN THE AFTERNOON.
GALES LOOK SOLID FOR THE SOUTH HALF OF THE THE LAKE...BUT DUE TO A
WEAKENING PRESSURE GRADIENT WITH TIME TODAY AND A MODEST HIGH
BUILDING INTO THE CANADIAN PRARIES AND UPPER MIDWEST...FEEL THAT
WINDS WILL LIKELY PEAK JUST UNDER GALES FOR THE NORTH HALF. A FEW
GALE FORCE GUSTS ARE POSSIBLE...ESPECIALLY LATE AFTERNOON/EARLY
EVENING.
WEAK HIGH PRESSSURE EXTENDING FROM THE NORTH TIP OF LAKE SUPERIOR TO
THE OHIO VALLEY PASSES OVER THE LAKE TUESDAY AFTERNOON. ANOTHER
WEAKENING LOW EMERGING FROM THE CANADIAN ROCKIES WILL PASS JUST
SOUTH OF THE TIP OF LAKE MICHIGAN WITH THE REMNANT INVERTED TROUGH
CLEARING THE LAKE BY THURSDAY MORNING. THIS WILL BE FOLLOWED BY WEAK
HIGH PRESSSURE FOR A FEW DAYS.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ008-ILZ010-
ILZ011...NOON MONDAY TO MIDNIGHT TUESDAY.
WINTER WEATHER ADVISORY...ILZ005-ILZ006-ILZ012...3 PM MONDAY TO
MIDNIGHT TUESDAY.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ740-LMZ741-
LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...9 AM MONDAY TO 3 AM TUESDAY.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
1147 PM CST Sun Nov 23 2014
.UPDATE...
ISSUED AT 910 PM CST SUN NOV 23 2014
Double low pressure centers have developed this evening, with one
circulation just northeast of Lawrenceville and another just west
of Galesburg. The trough connecting the two lows generally marks
the line of the back edge of steady rains and the onset of drizzle
and fog. Additional rains are approaching from across Missouri and
Iowa associated with increasing jet dynamics and a potential
vorticity anomaly. The return of steadier rains after midnight
from west to east will diminish fog and drizzle conditions as
winds steadily increase from the WSW. Colder air will approach
Illinois late tonight, but there will not be a deep enough layer
of cold air at the surface to change any rain to snow before
12z/6am in our counties. However, the blast of cold air will
quickly advance across IL Monday morning, with west winds
increasing to near wind advisory levels /30 mph sustained winds or
gusts to 45 mph/. Most areas should remain below those numbers, so
no wind advisory has been issued in our forecast area to this
point.
As the cold air changes any rain to snow, snow accums still look
possible generally north of a line from Rushville to Lincoln to
Bloomington, especially north of Peoria where up to an inch of
snow could accumulate. The snow will be blowing sideways as it
falls due to the strong winds, which will make it very difficult
to measure, and any accumulations on the ground will be blown
around as well. Visibility could drop to low levels during the
snows from mid morning to early afternoon, before snowfall rates
diminish during the afternoon.
Updates this evening have focused on weather grids through
tomorrow afternoon, and updated info is already available.
&&
.SHORT TERM...(Tonight)
ISSUED AT 313 PM CST SUN NOV 23 2014
Deepening 993 mb low pressure between Oklahoma City and Tulsa at mid
afternoon will strengthen further as it ejects northeast across
central IL near or east of I-55 during this evening, and into
northern lower MI overnight at it deepens to 979 mb. Widespread
light to moderate rain showers have spread NNE across central/se IL
early this afternoon. Still no reports of thunder over IL but will
continue to carry isolated thunderstorms over eastern IL into this
evening as deepening low pressure approaches.
Showers will break up later this evening and overnight east of the
IL river while deformation zone of precipitation lingers west of the
IL river. Strong cold front sweeps across central and eastern IL
during overnight, passing through the Wabash river valley early
Monday morning. Light rain to mix with light snow nw of the IL river
late tonight and change to snow early Monday morning as temps fall
into the mid 30s. Temperatures currently in the low to mid 50s and
dewpoints are in the upper 40s and lower 50s. Lows tonight to range
from mid 30s from Peoria and Springfield west, to the mid to upper
40s near the IN/IL border with temps continue to drop Monday
morning. Southeast winds 10-17 mph and gusts of 18-25 mph this
afternoon to subside this evening to around 10 mph or less as low
pressure moves in. But as low deepens and pulls away from central/se
IL overnight, winds will turn westerly behind the cold front and
increase to 15-25 mph and gust 25 to 30 mph later tonight. RUC model
shows even higher wind gusts of 35-40 mph going into southeast IL
behind cold front early Monday morning around sunrise. MET/MAV
guidance shows strongest winds during the day Monday (strongest in
eastern IL) after 15Z/9 am Monday.
&&
.LONG TERM...(Monday through Sunday)
ISSUED AT 313 PM CST SUN NOV 23 2014
The strong low pressure area will continue to lift northeast through
the Great Lakes area with a very strong pressure gradient behind the
system. In addition, gusty westerly winds and strong cold air
advection (CAA) will move into the area Monday. Expecting rain in
the eastern half of the CWA and a mix of rain and snow in the
western half,in the morning. Then as the CAA occurs, the all snow
line will move across the area from west to east, so that by early
afternoon, most of the CWA will be all snow, with the mix of rain
and snow only in the eastern parts of the CWA. By late afternoon,
the whole area will be cold enough for snow. As the system lifts
northeast through the day, the higher chances of pcpn will move from
southwest to northeast. So, the areas mostly likely to see any
accumulation of snow will be Northwest of I-55 during the morning and
then north of a Galesburg to Bloomington line during the afternoon.
Total snowfall accumulation expected tomorrow will be an inch or
more northwest of a Macomb to Pontiac line; and then lesser amounts
southeast of that line. Highest amounts are expected to be 1.5 to 2
inches north of a Galesburg to Lacon line.
The tight gradient behind this system will also bring very gusty
winds to the CWA tomorrow, beginning tomorrow morning and lasting
through the day. Sustained winds or around 25 mph with gusts between
35 and 40 mph will be possible across the whole area tomorrow. Will
not be issuing a wind advisory as it will be just below criteria.
However, would not be surprised if overnight shift issues one in the
morning. The gusty winds will also create blowing snow, mainly in
the northern parts of the CWA, so visibilities could be reduced at
times.
Pcpn will end by tomorrow night as the low pressure area lifts
northeast into Canada. After this system, dry weather is expected
for Monday night through Tue night as brief high pressure area moves
through the CWA. Then another clipper system is expected to move
through the area and bring another chance of rain and/or snow for
Wednesday. There will be some warm air ahead of this system so the
pcpn type could be a mix before it changes to all snow. Any
accumulations with this system will be confined to the north with a
half inch or less possible...at this time. The remainder of the
forecast should be dry with temps below normal, as Canadian high
pressure moves in and dominates the weather through the rest of the
week and into the weekend.
Temps will steady or slowly falling tomorrow due to the strong CAA
expected. Then temps will be cool/cold most of the rest of the
forecast, except for Wed, just ahead of the next clipper system.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1147 PM CST SUN NOV 23 2014
The pair of surface low centers have merged and lifted to the NE
of our forecast area, with a trailing cold front to the SW across
IL into southeast Missouri. Drizzle, fog and low clouds are
lingering behind the departing low along that trough, with VLIFR
ceilings at BMI, and LIFR ceilings at the remaining TAF sites.
Expect ceilings to improve slightly with the return redevelopment
of showers well behind the low, but remaining LIFR until Monday
afternoon when levels possibly climb all the way to MVFR.
Cold air will filter into central IL late tonight and Monday
morning, causing the rain showers to mix with or change to light
snow from west to east toward 6 am for PIA/SPI, 8 am for BMI, and
10 am for CMI/DEC. As the precipitation becomes all snow, vsbys
could drop below 1 mile at PIA and BMI where snowfall accumulation
could climb up as high as 1 inch. Vsbys should remain 2-4 miles
farther south toward I-72 where snowfall will be lighter. Snowfall
rates will diminish quickly after 18z-19z, with high winds blowing
any snow around and possibly keeping visibility low at times.
Winds have already become SW behind the low. Pressure rises will
climb to 6 mb/3 hours in at least the southeast half of our
forecast area, which would include DEC/CMI. Wind speeds in our
southeast areas could climb as high as 30g40kt between 12z and 15z
this morning, with other areas 25g35kt. Those speeds could
continue into early afternoon, but we should see some decrease in
peak gusts as the afternoon progresses.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...07
LONG TERM...Auten
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
315 PM EST MON NOV 24 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 340 AM EST MON NOV 24 2014
COLDER AIR WILL RETURN TO CENTRAL INDIANA LATER TODAY BEHIND THE
LOW PRESSURE SYSTEM AND COLD FRONT CURRENTLY IMPACTING THE AREA.
AS A RESULT...RAIN WILL TRANSITION TO SNOW LATE THIS
AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL. AFTER A
CHILLY BUT DRY DAY TOMORROW...ANOTHER SYSTEM WILL BRING LIGHT RAIN
AND SNOW ON WEDNESDAY. FURTHER OUT...THANKSGIVING DAY INTO THE
WEEKEND WILL BE COLD BUT DRY...AND PRECIPITATION WILL RETURN AGAIN
ON SUNDAY.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 1016 AM EST MON NOV 24 2014
FOR THE UPDATE...REMOVED THUNDER CHANCES WITH THE COLD FRONT
THROUGH THE AREA AND ALL THUNDER OFF TO THE EAST. DECREASED POPS
THIS AFTERNOON ACROSS THE NORTH BUT ADDED SOME LOW POPS TO THE
SOUTH BASED ON RECENT RUNS OF THE HRRR AND RAP AND WEAK WAVE
APPROACHING FROM THE SOUTHWEST. ALSO TRANSITIONED TO RAIN SNOW MIX A LITTLE
FASTER IN THE NORTHWEST BASED ON CURRENT OBS OF SNOW IN
ILLINOIS...BUT STILL THINK THE MAJORITY OF THAT WILL HEAD OFF TO
THE NORTHEAST AND MISS THE FORECAST AREA. STILL NOT EXPECTING MUCH
IF ANY ACCUMULATION. BUMPED HIGH END OF WIND GUSTS UP TO 50 MPH IN
THE NPW. TEMPERATURES WILL FALL FOR THE REMAINDER OF THE DAY.
PREVIOUS DISCUSSION FOLLOWS...
THE MAIN FOCUS OF THE NEAR TERM PERIOD WILL BE THE STRONG
SOUTHWEST WINDS...AS WELL AS PRECIP CHANCES AND TYPES.
AN AREA OF LOW PRESSURE IS CURRENTLY POSITIONED OVER LOWER
MICHIGAN WITH A WARM FRONT STRETCHING ACROSS OHIO...AND A TRAILING
COLD FRONT TRACKING ACROSS ILLINOIS. CURRENT RADAR MOSAIC SHOWS
SCATTERED SHOWERS WITH A FEW ISOLATED THUNDERSTORMS OVER MUCH OF
ILLINOIS AND THE SOUTHERN HALF OF CENTRAL INDIANA. FORCING FROM
THE COLD FRONT WILL JUSTIFY LIKELY POPS THROUGH LATE MORNING.
HOWEVER...BEST FORCING WILL BECOME CONFINED TO THE NORTHERN
COUNTIES THIS AFTERNOON AS UPPER TROUGH MOVES THROUGH THE AREA. AS
A RESULT...WILL ONLY CARRY MENTION OF PRECIP OVER THE NORTHERN
HALF OF CENTRAL INDIANA INTO TONIGHT...AND WILL GO WITH A DRY
FORECAST ACROSS THE SOUTHERN HALF. RAIN WILL TRANSITION TO SNOW
LATE THIS AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL
SINCE MOST MOISTURE WILL BE OUT OF THE AREA.
TEMPS WILL START OUT IN THE 50S THIS MORNING...BUT QUICKLY FALL
INTO THE MID 30S THROUGH THE COURSE OF THE DAY AS COLDER AIR
ENTERS THE AREA. TONIGHT...OVERNIGHT LOWS WILL FALL INTO THE UPPER
20S...STUCK CLOSE TO GUIDANCE.
A WIND ADVISORY REMAINS IN EFFECT FOR ALL OF CENTRAL INDIANA TODAY
AS PRESSURE GRADIENT TIGHTENS. SUSTAINED SPEEDS OUT OF THE
SOUTHWEST ARE EXPECTED TO BE BETWEEN 20 TO 25 MPH WITH GUSTS UP TO
45 MPH AT TIMES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 340 AM EST MON NOV 24 2014
DRY AND COOLER WEATHER WILL PREVAIL ON TUESDAY. HOWEVER...THE
PATTERN WILL BECOME MORE ACTIVE AGAIN BY WEDNESDAY AS AN UPPER
TROUGH TRACKS ACROSS THE LOWER MIDWEST. PRECIP SHOULD BE IN THE
FORM OF RAIN ACROSS THE SOUTHERN HALF OF CENTRAL INDIANA ON
WEDNESDAY WITH A RAIN/SNOW MIX OVER THE NORTHERN HALF. AS TEMPS
FALL ON WEDNESDAY NIGHT THOUGH...PRECIP WILL TRANSITION TO SNOW.
MODELS HAVE THIS DISTURBANCE MOVING THROUGH QUICKLY THOUGH...SO
SNOW ACCUMULATIONS SHOULD BE RELATIVELY LOW...LESS THAN AN INCH.
HIGH TEMPS THROUGH THE SHORT TERM PERIOD WILL BE IN THE 30S WITH
LOWS IN THE 20S. THE MAV CONTINUES TO LOOK A TAD TOO WARM...SO
STUCK CLOSER TO A MODEL BLEND.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 232 PM EST MON NOV 24 2014
ZONAL FLOW WILL COMMENCE THROUGH THE FIRST HALF OF THE
WEEKEND...KEEPING CONDITIONS MAINLY DRY. THE NEXT SYSTEM IS DUE TO
IMPACT THE REGION SATURDAY NIGHT INTO SUNDAY NIGHT WITH CHANCES FOR
RAIN...AND EVEN A RAIN/SNOW MIX POSSIBLE OVER THE NORTHERN COUNTIES
SUNDAY NIGHT. PRECIP ACCUMULATIONS STILL LOOK VERY LIGHT AT THIS
TIME SO LEFT POPS AT SLIGHT TO LOW END CHANCES. SUPERBLEND GUIDANCE
INITIALIZED WELL. ONLY NEED TO MAKE A FEW MINOR TWEAKS.
&&
.AVIATION /DISCUSSION FOR 242100Z TAF UPDATE/...
ISSUED AT 315 PM EST MON NOV 24 2014
MVFR CEILINGS WILL PREVAIL THROUGH THE ENTIRE PERIOD. INDICATED
EITHER A PREVAILING -SHSN OR A TEMPO GROUP UNTIL EVENING TO
ACCOUNT FOR THE SCATTERED LIGHT SNOW SHOWERS WHICH ARE DEVELOPING
OVER CENTRAL INDIANA. PER RECENT OBS NOT EXPECTING ANY REDUCTIONS
IN VISIBILITY...HOWEVER IT/S POSSIBLE A FEW STRONGER SHSN MAY
BRIEFLY DROP CONDITIONS TO MVFR AT A FEW OF THE SITES.
GUSTY WINDS WILL CONTINUE UNTIL LATE TONIGHT. STRONG WEST TO
SOUTHWEST WINDS UP TO 25 KNOTS AND GUSTS 30 TO 40 KNOTS WILL
CONTINUE THROUGH THIS AFTERNOON. WINDS WILL DECREASE SOME THIS
EVENING AS THE PRESSURE GRADIENT RELAXES A LITTLE...THEN BECOME 10
KT OR LESS BY EARLY TUESDAY MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR INZ021-028>030-
035>037-039-043>048-051>057-060>065-067>072.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ031-038-
040>042-049.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...CP
SHORT TERM...TDUD
LONG TERM....SMF
AVIATION...SMF/JK
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
233 PM EST MON NOV 24 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 340 AM EST MON NOV 24 2014
COLDER AIR WILL RETURN TO CENTRAL INDIANA LATER TODAY BEHIND THE
LOW PRESSURE SYSTEM AND COLD FRONT CURRENTLY IMPACTING THE AREA.
AS A RESULT...RAIN WILL TRANSITION TO SNOW LATE THIS
AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL. AFTER A
CHILLY BUT DRY DAY TOMORROW...ANOTHER SYSTEM WILL BRING LIGHT RAIN
AND SNOW ON WEDNESDAY. FURTHER OUT...THANKSGIVING DAY INTO THE
WEEKEND WILL BE COLD BUT DRY...AND PRECIPITATION WILL RETURN AGAIN
ON SUNDAY.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 1016 AM EST MON NOV 24 2014
FOR THE UPDATE...REMOVED THUNDER CHANCES WITH THE COLD FRONT
THROUGH THE AREA AND ALL THUNDER OFF TO THE EAST. DECREASED POPS
THIS AFTERNOON ACROSS THE NORTH BUT ADDED SOME LOW POPS TO THE
SOUTH BASED ON RECENT RUNS OF THE HRRR AND RAP AND WEAK WAVE
APPROACHING FROM THE SOUTHWEST. ALSO TRANSITIONED TO RAIN SNOW MIX A LITTLE
FASTER IN THE NORTHWEST BASED ON CURRENT OBS OF SNOW IN
ILLINOIS...BUT STILL THINK THE MAJORITY OF THAT WILL HEAD OFF TO
THE NORTHEAST AND MISS THE FORECAST AREA. STILL NOT EXPECTING MUCH
IF ANY ACCUMULATION. BUMPED HIGH END OF WIND GUSTS UP TO 50 MPH IN
THE NPW. TEMPERATURES WILL FALL FOR THE REMAINDER OF THE DAY.
PREVIOUS DISCUSSION FOLLOWS...
THE MAIN FOCUS OF THE NEAR TERM PERIOD WILL BE THE STRONG
SOUTHWEST WINDS...AS WELL AS PRECIP CHANCES AND TYPES.
AN AREA OF LOW PRESSURE IS CURRENTLY POSITIONED OVER LOWER
MICHIGAN WITH A WARM FRONT STRETCHING ACROSS OHIO...AND A TRAILING
COLD FRONT TRACKING ACROSS ILLINOIS. CURRENT RADAR MOSAIC SHOWS
SCATTERED SHOWERS WITH A FEW ISOLATED THUNDERSTORMS OVER MUCH OF
ILLINOIS AND THE SOUTHERN HALF OF CENTRAL INDIANA. FORCING FROM
THE COLD FRONT WILL JUSTIFY LIKELY POPS THROUGH LATE MORNING.
HOWEVER...BEST FORCING WILL BECOME CONFINED TO THE NORTHERN
COUNTIES THIS AFTERNOON AS UPPER TROUGH MOVES THROUGH THE AREA. AS
A RESULT...WILL ONLY CARRY MENTION OF PRECIP OVER THE NORTHERN
HALF OF CENTRAL INDIANA INTO TONIGHT...AND WILL GO WITH A DRY
FORECAST ACROSS THE SOUTHERN HALF. RAIN WILL TRANSITION TO SNOW
LATE THIS AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL
SINCE MOST MOISTURE WILL BE OUT OF THE AREA.
TEMPS WILL START OUT IN THE 50S THIS MORNING...BUT QUICKLY FALL
INTO THE MID 30S THROUGH THE COURSE OF THE DAY AS COLDER AIR
ENTERS THE AREA. TONIGHT...OVERNIGHT LOWS WILL FALL INTO THE UPPER
20S...STUCK CLOSE TO GUIDANCE.
A WIND ADVISORY REMAINS IN EFFECT FOR ALL OF CENTRAL INDIANA TODAY
AS PRESSURE GRADIENT TIGHTENS. SUSTAINED SPEEDS OUT OF THE
SOUTHWEST ARE EXPECTED TO BE BETWEEN 20 TO 25 MPH WITH GUSTS UP TO
45 MPH AT TIMES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 340 AM EST MON NOV 24 2014
DRY AND COOLER WEATHER WILL PREVAIL ON TUESDAY. HOWEVER...THE
PATTERN WILL BECOME MORE ACTIVE AGAIN BY WEDNESDAY AS AN UPPER
TROUGH TRACKS ACROSS THE LOWER MIDWEST. PRECIP SHOULD BE IN THE
FORM OF RAIN ACROSS THE SOUTHERN HALF OF CENTRAL INDIANA ON
WEDNESDAY WITH A RAIN/SNOW MIX OVER THE NORTHERN HALF. AS TEMPS
FALL ON WEDNESDAY NIGHT THOUGH...PRECIP WILL TRANSITION TO SNOW.
MODELS HAVE THIS DISTURBANCE MOVING THROUGH QUICKLY THOUGH...SO
SNOW ACCUMULATIONS SHOULD BE RELATIVELY LOW...LESS THAN AN INCH.
HIGH TEMPS THROUGH THE SHORT TERM PERIOD WILL BE IN THE 30S WITH
LOWS IN THE 20S. THE MAV CONTINUES TO LOOK A TAD TOO WARM...SO
STUCK CLOSER TO A MODEL BLEND.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 232 PM EST MON NOV 24 2014
ZONAL FLOW WILL COMMENCE THROUGH THE FIRST HALF OF THE
WEEKEND...KEEPING CONDITIONS MAINLY DRY. THE NEXT SYSTEM IS DUE TO
IMPACT THE REGION SATURDAY NIGHT INTO SUNDAY NIGHT WITH CHANCES FOR
RAIN...AND EVEN A RAIN/SNOW MIX POSSIBLE OVER THE NORTHERN COUNTIES
SUNDAY NIGHT. PRECIP ACCUMULATIONS STILL LOOK VERY LIGHT AT THIS
TIME SO LEFT POPS AT SLIGHT TO LOW END CHANCES. SUPERBLEND GUIDANCE
INITIALIZED WELL. ONLY NEED TO MAKE A FEW MINOR TWEAKS.
&&
.AVIATION /DISCUSSION FOR THE 241800Z TAF ISSUANCE...
ISSUED AT 1152 AM EST MON NOV 24 2014
MVFR CEILINGS WILL PREVAIL THROUGH THE ENTIRE PERIOD WITH IFR
CONDITIONS POSSIBLE IN ANY MODERATE SNOW SHOWERS THROUGH THIS
AFTERNOON. INDICATED EITHER A PREVAILING -SHSN OR A TEMPO GROUP
FOR THE FIRST 3-4 HOURS OF THE TAF PERIOD TO ACCOUNT FOR THE
SCATTERED LIGHT SNOW SHOWERS AND/OR FLURRIES WHICH ARE DEVELOPING
OVER CENTRAL INDIANA. PER RECENT OBS NOT EXPECTING ANY REDUCTIONS
IN VIS...HOWEVER IT/S POSSIBLE A FEW STRONGER SHSN MAY POP UP AND
BRIEFLY DROP CONDITIONS TO IFR AT A FEW OF THE SITES. CHANCES NOT
HIGH/CONFIDENT ENOUGH TO INCLUDE THIS AT THIS TIME...BUT IT/S A
POSSIBILITY.
GUSTY WINDS WILL CONTINUE UNTIL LATE TONIGHT. STRONG WEST TO
SOUTHWEST WINDS UP TO 25 KNOTS AND GUSTS 30 TO 40 KNOTS WILL
CONTINUE THROUGH THIS AFTERNOON. WINDS WILL DECREASE SOME THIS
EVENING AS THE PRESSURE GRADIENT RELAXES A LITTLE...THEN BECOME 10
KT OR LESS BY EARLY TUESDAY MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR INZ021-028>030-
035>037-039-043>048-051>057-060>065-067>072.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ031-038-
040>042-049.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...CP
SHORT TERM...TDUD
LONG TERM....SMF
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1200 PM EST MON NOV 24 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 340 AM EST MON NOV 24 2014
COLDER AIR WILL RETURN TO CENTRAL INDIANA LATER TODAY BEHIND THE
LOW PRESSURE SYSTEM AND COLD FRONT CURRENTLY IMPACTING THE AREA.
AS A RESULT...RAIN WILL TRANSITION TO SNOW LATE THIS
AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL. AFTER A
CHILLY BUT DRY DAY TOMORROW...ANOTHER SYSTEM WILL BRING LIGHT RAIN
AND SNOW ON WEDNESDAY. FURTHER OUT...THANKSGIVING DAY INTO THE
WEEKEND WILL BE COLD BUT DRY...AND PRECIPITATION WILL RETURN AGAIN
ON SUNDAY.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 1016 AM EST MON NOV 24 2014
FOR THE UPDATE...REMOVED THUNDER CHANCES WITH THE COLD FRONT
THROUGH THE AREA AND ALL THUNDER OFF TO THE EAST. DECREASED POPS
THIS AFTERNOON ACROSS THE NORTH BUT ADDED SOME LOW POPS TO THE
SOUTH BASED ON RECENT RUNS OF THE HRRR AND RAP AND WEAK WAVE
APPROACHING FROM THE SOUTHWEST. ALSO TRANSITIONED TO RAIN SNOW MIX A LITTLE
FASTER IN THE NORTHWEST BASED ON CURRENT OBS OF SNOW IN
ILLINOIS...BUT STILL THINK THE MAJORITY OF THAT WILL HEAD OFF TO
THE NORTHEAST AND MISS THE FORECAST AREA. STILL NOT EXPECTING MUCH
IF ANY ACCUMULATION. BUMPED HIGH END OF WIND GUSTS UP TO 50 MPH IN
THE NPW. TEMPERATURES WILL FALL FOR THE REMAINDER OF THE DAY.
PREVIOUS DISCUSSION FOLLOWS...
THE MAIN FOCUS OF THE NEAR TERM PERIOD WILL BE THE STRONG
SOUTHWEST WINDS...AS WELL AS PRECIP CHANCES AND TYPES.
AN AREA OF LOW PRESSURE IS CURRENTLY POSITIONED OVER LOWER
MICHIGAN WITH A WARM FRONT STRETCHING ACROSS OHIO...AND A TRAILING
COLD FRONT TRACKING ACROSS ILLINOIS. CURRENT RADAR MOSAIC SHOWS
SCATTERED SHOWERS WITH A FEW ISOLATED THUNDERSTORMS OVER MUCH OF
ILLINOIS AND THE SOUTHERN HALF OF CENTRAL INDIANA. FORCING FROM
THE COLD FRONT WILL JUSTIFY LIKELY POPS THROUGH LATE MORNING.
HOWEVER...BEST FORCING WILL BECOME CONFINED TO THE NORTHERN
COUNTIES THIS AFTERNOON AS UPPER TROUGH MOVES THROUGH THE AREA. AS
A RESULT...WILL ONLY CARRY MENTION OF PRECIP OVER THE NORTHERN
HALF OF CENTRAL INDIANA INTO TONIGHT...AND WILL GO WITH A DRY
FORECAST ACROSS THE SOUTHERN HALF. RAIN WILL TRANSITION TO SNOW
LATE THIS AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL
SINCE MOST MOISTURE WILL BE OUT OF THE AREA.
TEMPS WILL START OUT IN THE 50S THIS MORNING...BUT QUICKLY FALL
INTO THE MID 30S THROUGH THE COURSE OF THE DAY AS COLDER AIR
ENTERS THE AREA. TONIGHT...OVERNIGHT LOWS WILL FALL INTO THE UPPER
20S...STUCK CLOSE TO GUIDANCE.
A WIND ADVISORY REMAINS IN EFFECT FOR ALL OF CENTRAL INDIANA TODAY
AS PRESSURE GRADIENT TIGHTENS. SUSTAINED SPEEDS OUT OF THE
SOUTHWEST ARE EXPECTED TO BE BETWEEN 20 TO 25 MPH WITH GUSTS UP TO
45 MPH AT TIMES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 340 AM EST MON NOV 24 2014
DRY AND COOLER WEATHER WILL PREVAIL ON TUESDAY. HOWEVER...THE
PATTERN WILL BECOME MORE ACTIVE AGAIN BY WEDNESDAY AS AN UPPER
TROUGH TRACKS ACROSS THE LOWER MIDWEST. PRECIP SHOULD BE IN THE
FORM OF RAIN ACROSS THE SOUTHERN HALF OF CENTRAL INDIANA ON
WEDNESDAY WITH A RAIN/SNOW MIX OVER THE NORTHERN HALF. AS TEMPS
FALL ON WEDNESDAY NIGHT THOUGH...PRECIP WILL TRANSITION TO SNOW.
MODELS HAVE THIS DISTURBANCE MOVING THROUGH QUICKLY THOUGH...SO
SNOW ACCUMULATIONS SHOULD BE RELATIVELY LOW...LESS THAN AN INCH.
HIGH TEMPS THROUGH THE SHORT TERM PERIOD WILL BE IN THE 30S WITH
LOWS IN THE 20S. THE MAV CONTINUES TO LOOK A TAD TOO WARM...SO
STUCK CLOSER TO A MODEL BLEND.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 340 AM EST MON NOV 24 2014
IN THE LONG TERM MODELS INDICATE A PROGRESSIVE SOMEWHAT ZONAL UPPER
FLOW. A BROAD UPPER TROUGH ACROSS EASTERN CANADA AND THE GREAT LAKES
THURSDAY WILL MOVE ON TO THE EAST TO BE REPLACED BY A WEAKER UPPER
TROUGH BY THE END OF DAY 7.
FOR THANKSGIVING DAY ADDED A CHANCE OF FLURRIES OVER THE EASTERN
HALF OF OUR REGION AS AN UPPER DISTURBANCE MOVES FROM THE UPPER OHIO
VALLEY TO THE EAST COAST. OTHERWISE...DRY WEATHER WILL BE THE RULE
THROUGH FRIDAY NIGHT AS HIGH PRESSURE MOVES OVER THE UPPER MI9WEST
MOVES ACROSS OUR REGION LATE THURSDAY NIGHT AND FRIDAY AND ON TO THE
EAST COAST. SOME MODELS INDICATE LOW CHANCE POPS ACROSS OUR FAR
NORTH FRIDAY...BUT HAVE DECIDED TO KEEP IT DRY FOR NOW.
OVER THE WEEKEND MODELS INDICATE INCREASING WARM ADVECTION AS LOW
PRESSURE MOVES INTO THE PLAINS. THEY ALL GENERATE SOME PRECIP
BEGINNING SATURDAY AND CONTINUING IT THROUGH SUNDAY AS A WARM FRONT
MOVES INTO THE MID MISSISSIPPI VALLEY AND A COLD FRONT APPROACHES
FROM THE UPPER MIDWEST BY SUNDAY.
MODELS HAVE TERNED A LITTLE WARMER OVER THE WEEKEND AND ANY
PRECIPITATION SHOULD BE MOSTLY LIQUID. CONCERNING TEMPERATURES WENT
WITH A MOS BLEND EARLY ON AND SLIGHTLY ABOVE OVER THE WEEKEND AS
WARM ADVECTION INCREASES.
&&
.AVIATION /DISCUSSION FOR THE 241800Z TAF ISSUANCE...
ISSUED AT 1152 AM EST MON NOV 24 2014
MVFR CEILINGS WILL PREVAIL THROUGH THE ENTIRE PERIOD WITH IFR
CONDITIONS POSSIBLE IN ANY MODERATE SNOW SHOWERS THROUGH THIS
AFTERNOON. INDICATED EITHER A PREVAILING -SHSN OR A TEMPO GROUP
FOR THE FIRST 3-4 HOURS OF THE TAF PERIOD TO ACCOUNT FOR THE
SCATTERED LIGHT SNOW SHOWERS AND/OR FLURRIES WHICH ARE DEVELOPING
OVER CENTRAL INDIANA. PER RECENT OBS NOT EXPECTING ANY REDUCTIONS
IN VIS...HOWEVER IT/S POSSIBLE A FEW STRONGER SHSN MAY POP UP AND
BRIEFLY DROP CONDITIONS TO IFR AT A FEW OF THE SITES. CHANCES NOT
HIGH/CONFIDENT ENOUGH TO INCLUDE THIS AT THIS TIME...BUT IT/S A
POSSIBILITY.
GUSTY WINDS WILL CONTINUE UNTIL LATE TONIGHT. STRONG WEST TO
SOUTHWEST WINDS UP TO 25 KNOTS AND GUSTS 30 TO 40 KNOTS WILL
CONTINUE THROUGH THIS AFTERNOON. WINDS WILL DECREASE SOME THIS
EVENING AS THE PRESSURE GRADIENT RELAXES A LITTLE...THEN BECOME 10
KT OR LESS BY EARLY TUESDAY MORNING.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR INZ021-028>030-
035>037-039-043>048-051>057-060>065-067>072.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ031-038-
040>042-049.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...CP
SHORT TERM...TDUD
LONG TERM....JH
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1025 AM EST MON NOV 24 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 340 AM EST MON NOV 24 2014
COLDER AIR WILL RETURN TO CENTRAL INDIANA LATER TODAY BEHIND THE
LOW PRESSURE SYSTEM AND COLD FRONT CURRENTLY IMPACTING THE AREA.
AS A RESULT...RAIN WILL TRANSITION TO SNOW LATE THIS
AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL. AFTER A
CHILLY BUT DRY DAY TOMORROW...ANOTHER SYSTEM WILL BRING LIGHT RAIN
AND SNOW ON WEDNESDAY. FURTHER OUT...THANKSGIVING DAY INTO THE
WEEKEND WILL BE COLD BUT DRY...AND PRECIPITATION WILL RETURN AGAIN
ON SUNDAY.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 1016 AM EST MON NOV 24 2014
FOR THE UPDATE...REMOVED THUNDER CHANCES WITH THE COLD FRONT
THROUGH THE AREA AND ALL THUNDER OFF TO THE EAST. DECREASED POPS
THIS AFTERNOON ACROSS THE NORTH BUT ADDED SOME LOW POPS TO THE
SOUTH BASED ON RECENT RUNS OF THE HRRR AND RAP AND WEAK WAVE
APPROACHING FROM THE SOUTHWEST. ALSO TRANSITIONED TO RAIN SNOW MIX A LITTLE
FASTER IN THE NORTHWEST BASED ON CURRENT OBS OF SNOW IN
ILLINOIS...BUT STILL THINK THE MAJORITY OF THAT WILL HEAD OFF TO
THE NORTHEAST AND MISS THE FORECAST AREA. STILL NOT EXPECTING MUCH
IF ANY ACCUMULATION. BUMPED HIGH END OF WIND GUSTS UP TO 50 MPH IN
THE NPW. TEMPERATURES WILL FALL FOR THE REMAINDER OF THE DAY.
PREVIOUS DISCUSSION FOLLOWS...
THE MAIN FOCUS OF THE NEAR TERM PERIOD WILL BE THE STRONG
SOUTHWEST WINDS...AS WELL AS PRECIP CHANCES AND TYPES.
AN AREA OF LOW PRESSURE IS CURRENTLY POSITIONED OVER LOWER
MICHIGAN WITH A WARM FRONT STRETCHING ACROSS OHIO...AND A TRAILING
COLD FRONT TRACKING ACROSS ILLINOIS. CURRENT RADAR MOSAIC SHOWS
SCATTERED SHOWERS WITH A FEW ISOLATED THUNDERSTORMS OVER MUCH OF
ILLINOIS AND THE SOUTHERN HALF OF CENTRAL INDIANA. FORCING FROM
THE COLD FRONT WILL JUSTIFY LIKELY POPS THROUGH LATE MORNING.
HOWEVER...BEST FORCING WILL BECOME CONFINED TO THE NORTHERN
COUNTIES THIS AFTERNOON AS UPPER TROUGH MOVES THROUGH THE AREA. AS
A RESULT...WILL ONLY CARRY MENTION OF PRECIP OVER THE NORTHERN
HALF OF CENTRAL INDIANA INTO TONIGHT...AND WILL GO WITH A DRY
FORECAST ACROSS THE SOUTHERN HALF. RAIN WILL TRANSITION TO SNOW
LATE THIS AFTERNOON/EVENING...BUT ACCUMULATIONS WILL BE MINIMAL
SINCE MOST MOISTURE WILL BE OUT OF THE AREA.
TEMPS WILL START OUT IN THE 50S THIS MORNING...BUT QUICKLY FALL
INTO THE MID 30S THROUGH THE COURSE OF THE DAY AS COLDER AIR
ENTERS THE AREA. TONIGHT...OVERNIGHT LOWS WILL FALL INTO THE UPPER
20S...STUCK CLOSE TO GUIDANCE.
A WIND ADVISORY REMAINS IN EFFECT FOR ALL OF CENTRAL INDIANA TODAY
AS PRESSURE GRADIENT TIGHTENS. SUSTAINED SPEEDS OUT OF THE
SOUTHWEST ARE EXPECTED TO BE BETWEEN 20 TO 25 MPH WITH GUSTS UP TO
45 MPH AT TIMES.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ISSUED AT 340 AM EST MON NOV 24 2014
DRY AND COOLER WEATHER WILL PREVAIL ON TUESDAY. HOWEVER...THE
PATTERN WILL BECOME MORE ACTIVE AGAIN BY WEDNESDAY AS AN UPPER
TROUGH TRACKS ACROSS THE LOWER MIDWEST. PRECIP SHOULD BE IN THE
FORM OF RAIN ACROSS THE SOUTHERN HALF OF CENTRAL INDIANA ON
WEDNESDAY WITH A RAIN/SNOW MIX OVER THE NORTHERN HALF. AS TEMPS
FALL ON WEDNESDAY NIGHT THOUGH...PRECIP WILL TRANSITION TO SNOW.
MODELS HAVE THIS DISTURBANCE MOVING THROUGH QUICKLY THOUGH...SO
SNOW ACCUMULATIONS SHOULD BE RELATIVELY LOW...LESS THAN AN INCH.
HIGH TEMPS THROUGH THE SHORT TERM PERIOD WILL BE IN THE 30S WITH
LOWS IN THE 20S. THE MAV CONTINUES TO LOOK A TAD TOO WARM...SO
STUCK CLOSER TO A MODEL BLEND.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 340 AM EST MON NOV 24 2014
IN THE LONG TERM MODELS INDICATE A PROGRESSIVE SOMEWHAT ZONAL UPPER
FLOW. A BROAD UPPER TROUGH ACROSS EASTERN CANADA AND THE GREAT LAKES
THURSDAY WILL MOVE ON TO THE EAST TO BE REPLACED BY A WEAKER UPPER
TROUGH BY THE END OF DAY 7.
FOR THANKSGIVING DAY ADDED A CHANCE OF FLURRIES OVER THE EASTERN
HALF OF OUR REGION AS AN UPPER DISTURBANCE MOVES FROM THE UPPER OHIO
VALLEY TO THE EAST COAST. OTHERWISE...DRY WEATHER WILL BE THE RULE
THROUGH FRIDAY NIGHT AS HIGH PRESSURE MOVES OVER THE UPPER MI9WEST
MOVES ACROSS OUR REGION LATE THURSDAY NIGHT AND FRIDAY AND ON TO THE
EAST COAST. SOME MODELS INDICATE LOW CHANCE POPS ACROSS OUR FAR
NORTH FRIDAY...BUT HAVE DECIDED TO KEEP IT DRY FOR NOW.
OVER THE WEEKEND MODELS INDICATE INCREASING WARM ADVECTION AS LOW
PRESSURE MOVES INTO THE PLAINS. THEY ALL GENERATE SOME PRECIP
BEGINNING SATURDAY AND CONTINUING IT THROUGH SUNDAY AS A WARM FRONT
MOVES INTO THE MID MISSISSIPPI VALLEY AND A COLD FRONT APPROACHES
FROM THE UPPER MIDWEST BY SUNDAY.
MODELS HAVE TERNED A LITTLE WARMER OVER THE WEEKEND AND ANY
PRECIPITATION SHOULD BE MOSTLY LIQUID. CONCERNING TEMPERATURES WENT
WITH A MOS BLEND EARLY ON AND SLIGHTLY ABOVE OVER THE WEEKEND AS
WARM ADVECTION INCREASES.
&&
.AVIATION /DISCUSSION FOR THE 241200Z TAF ISSUANCE...
ISSUED AT 923 AM EST MON NOV 24 2014
1420Z UPDATE...VERY FEW CHANGES NEEDED WITH THIS MORNING/S UPDATE.
ONLY NEEDED TO TWEAK THE WINDS AND REMOVE -SHRA AND REPLACE WITH
VCSH FOR THE NEXT FEW HOURS. PREVIOUS DISCUSSION FOLLOWS.
MVFR CEILINGS WITH WORSE CONDITIONS AT TIMES THIS MORNING. GUSTY
WINDS WILL BE THE RULE UNTIL LATE TONIGHT.
RADAR INDICATES NUMEROUS SHOWERS ACROSS THE AREA. A FEW
THUNDERSTORMS COULD AFFECT KIND AND KBMG FOR THE 1ST HOUR BEFORE
THEY MOVE ON TO THE EAST.
MEANWHILE STRONG LOW PRESSURE WAS OVER THE NORTHERN GREAT LAKES AND
A COLD FRONT EXTENDED SOUTH ALONG THE INDIANA ILLINOIS BORDER. THIS
COLD FRONT WILL MOVE RAPIDLY EAST ACROSS INDIANA THIS MORNING. RADAR
LOOPS AND MODELS INDICATE SHOWERS SHOULD DIMINISH BY LATE MORNING.
CEILINGS MAY IMPROVE A LITTLE...BUT WILL MOST LIKELY REMAIN MVFR
CEILINGS THIS AFTERNOON AND WELL INTO TONIGHT.
MORE SIGNIFICANT WILL BE STRONG WEST TO SOUTHWEST WINDS UP TO 25
KNOTS AND GUSTS UP TO 35 KNOTS BY LATE MORNING AND THIS AFTERNOON.
WINDS WILL DECREASE SOME TONIGHT AS PRESSURE GRADIENT RELAXES A
LITTLE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR INZ021-028>030-
035>037-039-043>048-051>057-060>065-067>072.
WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ031-038-
040>042-049.
&&
$$
SYNOPSIS...TDUD
NEAR TERM...CP
SHORT TERM...TDUD
LONG TERM....JH
AVIATION...SMF/JH
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1151 PM EST SUN NOV 23 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 307 PM EST SUN NOV 23 2014
AN AREA OF LOW PRESSURE AND A COLD FRONT WILL BRING RAIN TO CENTRAL
INDIANA TONIGHT INTO MONDAY. BEHIND THE FRONT WILL COME WINDY AND
MUCH COLDER CONDITIONS. ANOTHER SYSTEM COULD BRING SOME LIGHT RAIN
AND SNOW TO THE AREA ON WEDNESDAY. THANKSGIVING INTO SATURDAY WILL
BE COLD AND DRY BEFORE ANOTHER SYSTEM BRINGS LOW CHANCES FOR
PRECIPITATION SUNDAY.
&&
.NEAR TERM /OVERNIGHT/...
ISSUED AT 959 PM EST SUN NOV 23 2014
DUAL AREAS OF LOW PRESSURE CURRENTLY IN THE PROCESS OF COALESCING
ACROSS CENTRAL ILLINOIS AND INTENSIFYING. A WARM FRONT EXTENDS
SOUTHEAST FROM THE DOUBLE BARRELED LOW INTO THE SOUTHERN
APPALACHIANS WITH A LARGE AREA OF MODERATE TO OCCASIONALLY HEAVY
RAINFALL ENCOMPASSING MUCH OF THE FORECAST AREA NORTH OF THE
FRONT. TEMPS WERE IN THE LOWER AND MIDDLE 50S AS OF 0230Z.
FORECAST IS IN REALLY GOOD SHAPE...WITH JUST SOME MINOR
ADJUSTMENTS FOR THE REST OF THE OVERNIGHT. INITIAL POCKET OF DRY
AIR LIFTING UP THROUGH EASTERN COUNTIES RIGHT NOW WITH THE MORE
EXPANSIVE DRY SLOT SOUTH OF THE WARM FRONT IN THE LOWER OHIO
VALLEY. HEAVIEST AREA OF RAIN MOVING NORTH OUT OF THE INDY METRO
AREA AND WILL LIFT NORTH OUT OF THE FORECAST AREA BY 06Z. MANY
LOCATIONS ACROSS CENTRAL INDIANA ALREADY AROUND 1.50 INCHES FOR
THE DAY.
WRF AND HRRR BOTH HAVE A NICE HANDLE ON THE RAINFALL COVERAGE
WITH A 3-4 HOUR DRY SLOT EXPANDING ACROSS THE FORECAST AREA FROM
THE BETWEEN 05-10Z AS THE WARM FRONT LIFTS NORTH. WILL KEEP LOWER
POPS DURING THIS TIMEFRAME...THEN RAMP THEM BACK UP TOWARDS
DAYBREAK AS THE CONVECTION OVER SOUTHERN MISSOURI ARRIVES AHEAD OF
THE COLD FRONT. HAVE BACKED OFF ON ISOLATED THUNDER TO LATE
TONIGHT AND EARLY MONDAY MORNING AS THE CONVECTION ALONG THE COLD
FRONT TRACKS THROUGH THE AREA.
TEMPS SHOULD WARM A COUPLE MORE DEGREES OR REMAIN STEADY OVER THE
NEXT SEVERAL HOURS BEFORE BEGINNING TO SLIP BACK TOWARDS DAYBREAK
WITH THE ARRIVAL OF THE COLD FRONT. WINDS WILL BECOME GUSTY
OVERNIGHT AS WELL AS ALREADY SEEING OBS WITH GUSTS PUSHING 30MPH
IN WESTERN KENTUCKY.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
ISSUED AT 307 PM EST SUN NOV 23 2014
FOCUS IS ON WINDY CONDITIONS MONDAY AND ON ANY CHANCES FOR RAIN
THROUGH THE PERIOD. FOR THE MOST PART MODELS ARE CLOSE ENOUGH THAT A
BLEND CAN BE USED...BUT GFS LOOKS TOO FAST WITH WEDNESDAY/S SYSTEM.
RELIED LESS ON GFS THEN.
LOOKS LIKE THERE WILL BE SOME DECENT FORCING WITH THE COLD
FRONT...AND MOST MODELS ARE PUTTING OUT RAINFALL WITH THE FRONT AS
IT PASSES THROUGH. THUS WENT LIKELY POPS MOST AREAS MONDAY MORNING.
AS FRONT PASSES BY FORCING WILL WEAKEN SO LOWERED POPS AFTER IT GOES
BY.
FORCING WITH THE UPPER TROUGH WILL STILL BE CLOSE ENOUGH TO THE AREA
TO GO CHANCE POPS ACROSS THE NORTHWEST FORECAST AREA MONDAY
AFTERNOON AND SLIGHT CHANCE REMAINDER OF NORTH HALF. AS COLDER AIR
MOVES IN DURING THE DAY PRECIPITATION WILL MIX WITH AND CHANGE TO
SNOW. NOT EXPECTING ANY ACCUMULATION AT THIS TIME.
MAIN STORY MONDAY WILL BE THE WINDS. STRONG WINDS WILL BE NOT TOO
FAR OFF THE SURFACE...WITH 850MB WINDS OVER 50KT AND 925MB WINDS
OVER 40KT. SURFACE PRESSURE GRADIENT WILL BE TIGHT ACROSS THE AREA.
THESE PLUS COLD ADVECTION HELPING MIX THE WINDS DOWN WILL CREATE
WINDY CONDITIONS ACROSS THE ENTIRE AREA. SREF FORECASTS SHOW HIGH
CHANCES OF SUSTAINED WINDS OVER 25KT ACROSS PARTS OF THE AREA MONDAY
AS WELL.
STRONGEST WINDS LOOK TO BE ACROSS THE NORTHEAST FORECAST AREA IN THE
TIGHTER PRESSURE GRADIENT WHERE WIND GUSTS AROUND 45 MPH WILL BE
POSSIBLE. ELSEWHERE WINDS COULD GUST AROUND 40 MPH AND WILL BE CLOSE
TO ADVISORY CRITERIA. /GFS SHOWS EVEN HIGHER GUSTS POSSIBLE...WITH
GUSTS MORE WIDESPREAD THAN THE NAM/. AFTER COLLABORATING WITH
SURROUNDING OFFICES DECIDED TO GO WIND ADVISORY ACROSS ALL OF THE
AREA.
FOR MOST AREAS WENT 12Z-00Z...BUT IN THE NORTHEAST WHERE PRESSURE
GRADIENT WILL ARRIVE LATER AND REMAIN A FACTOR LONGER...WENT 14Z-03Z.
UPPER TROUGH COULD STILL BRING A FEW SNOW SHOWERS TO NORTHERN AREAS
MONDAY NIGHT. HIGH PRESSURE WILL BRING DRY CONDITIONS TO THE AREA
TUESDAY INTO WEDNESDAY MORNING.
ANOTHER FRONT WILL BRING CHANCES FOR PRECIPITATION WEDNESDAY
AFTERNOON. UNCERTAINTIES IN TIMING AND FORCING LEADS TO ONLY LOW
POPS FOR NOW. BASED ON EXPECTED TEMPERATURES WENT MIXED RAIN AND
SNOW MOST AREAS.
LOOKING AT TEMPERATURES...ON MONDAY READINGS WILL FALL DURING THE
DAY. A MODEL BLEND LOOKS GOOD FOR LOWS MONDAY NIGHT. MAV MOS LOOKS
TOO WARM ON TUESDAY WITH EXPECTED CLOUD COVER. WENT CLOSER TO A
MODEL BLEND.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 224 PM EST SUN NOV 23 2014
A BROAD UPPER TROUGH MAY BRING MIX PRECIP CHANCES TO THE AREA AT THE
BEGINNING OF THE PERIOD AND THEN ZONAL FLOW WILL COMMENCE THROUGH
THE FIRST HALF OF NEXT WEEKEND. AN UPPER LEVEL DISTURBANCE IS NEXT
DUE TO IMPACT THE REGION SATURDAY NIGHT INTO SUNDAY WITH CHANCES FOR
RAIN/RAIN AND SNOW MIX/AND SNOW. ACCUMULATIONS APPEAR VERY LIGHT AT
THIS TIME AND THIS IS NOT A LOT OF CONFIDENCE THIS FAR OUT IN THE
EXTENDED SO STUCK WITH 20 PERCENT POPS. SUPERBLEND GUIDANCE
INITIALIZED WELL. ONLY NEED TO MAKE A FEW MINOR TWEAKS.
&&
.AVIATION /DISCUSSION FOR THE 24/06Z TAFS/...
ISSUED AT 1151 PM EST SUN NOV 23 2014
MVFR OR WORSE CONDITIONS TO PERSIST THROUGH AT LEAST THE FIRST 10-12
HOURS OF THE PERIOD.
RAPIDLY STRENGTHENING LOW PRESSURE MOVING THROUGH THE REGION TONIGHT
INTO TOMORROW. DRY PUNCH MOVING INTO THE AREA BUT ADDITIONAL SHOWERS
LIKELY AT TIMES LATER IN THE NIGHT INTO EARLY MORNING.
COULD SEE SOME GUSTINESS OVERNIGHT AS THE LOW STRENGTHENS. LOW LEVEL
WIND SHEAR IS A MORE POTENT THREAT EAST OF THE SITES WHERE THE LOW
LEVEL JET WILL BE FAR MORE PRONOUNCED...AND AREA VAD WIND PROFILES
SUPPORT WINDS BELOW 2KFT NO MORE THAN 30-35KT AT THIS TIME...AND
GUSTINESS IMPLIES SHEAR ANYWAY.
AS THE COLD FRONT PASSES TOMORROW MORNING AND THE SURFACE PRESSURE
GRADIENT TIGHTENS...LOW LEVEL WINDS WILL STRENGTHEN AND COLD
ADVECTION WILL HELP MIX SOME OF THIS DOWN TO THE SURFACE. WIND GUSTS
FROM THE WEST/SOUTHWEST MAY APPROACH AND EVEN OCCASIONALLY EXCEED
40KT AT THE SITES...ESPECIALLY TOMORROW AFTERNOON.
THUNDER WILL BE AT LEAST A MARGINAL THREAT WITH THE RAPID
DEVELOPMENT OF THE LOW...STRONG DYNAMICS...AND AT LEAST A SMALL
AMOUNT OF SHALLOW INSTABILITY...BUT WITH NO CONFIDENCE IN TIMING OR
PLACEMENT OF THE THREAT...CANNOT INCLUDE A MENTION AT THIS TIME.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 7 AM TO 7 PM EST MONDAY FOR INZ021-028>030-
035>037-039-043>048-051>057-060>065-067>072.
WIND ADVISORY FROM 9 AM TO 10 PM EST MONDAY FOR INZ031-038-
040>042-049.
&&
$$
SYNOPSIS...50
NEAR TERM...RYAN
SHORT TERM...50
LONG TERM...SMF
AVIATION...NIELD
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AREA FORECAST DISCUSSION
NWS DODGE CITY KS
518 PM CST TUE NOV 25 2014
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY)
ISSUED AT 1200 PM CST TUE NOV 25 2014
INCREASING MID TO HIGH LEVEL CLOUDS EXPECTED THROUGH THE AFTERNOON AND
INTO THE EVENING AS AN UPPER LEVEL DISTURBANCE MOVES IN FROM THE NORTHWEST.
NO PRECIPITATION IS EXPECTED. SOUTHWESTERLY WINDS AHEAD OF A LEE SURFACE
TROUGH WILL CONTINUE THROUGH THE AFTERNOON. EVENTUALLY, A COLD FRONT
WILL MOVE ACROSS THE REGION DURING THE OVERNIGHT PERIOD. MINIMUMS WILL
BE SLIGHTLY WARMER WITH MID 20S WEST TO LOWER 30S EAST VIA DOWNSLOPE
NORTHWESTERLY WINDS AND ALSO SLIGHT INFLUENCE FROM THE AFOREMENTIONED
CLOUDS. FOR TOMORROW, HIGH PRESSURE WILL CONTINUE ACROSS THE PLAINS
WITH NORTHWESTERLY WINDS IN THE 10 TO 20 MPH RANGE. MAXIMUMS WILL BE
IN THE 40S ACROSS THE NORTHERN AND CENTRAL ZONES TO AROUND 50 NEAR THE
OKLAHOMA BORDER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 347 PM CST TUE NOV 25 2014
THE LATE WEEK INTO FIRST PART OF THE WEEKEND WARM-UP IS STILL ON
TRACK. FRIDAY IS CURRENTLY THE WARMEST DAY OF THE THREE DAYS
(THURSDAY, FRIDAY, SATURDAY) THAT WILL BE ABOVE AVERAGE, WITH AN
UPDATED FORECAST HIGH OF 69 AT DODGE CITY AND LOWER 70S TO THE WEST
TO THE COLORADO BORDER. IF THE ECMWF MODEL IS CORRECT, SATURDAY MAY
BE WARMER THAN FRIDAY WITH LOWER 70S SPREADING TO DODGE CITY WITH
UPPER 60S TO A PRATT-MEDICINE LODGE LINE. THE WEST-SOUTHWESTERLY
DOWNSLOPE MOMENTUM WILL BE VERY IMPRESSIVE IN THE 700-500MB LAYER,
WHICH IS WHY THE 850MB MASS AND THERMAL FIELDS IN RESPONSE OFF THE
ECMWF SEEM MORE APPROPRIATE. NEVERTHELESS, OFFICIAL HIGHS SATURDAY
WILL STILL BE A BIT LOWER THAN ECMWF, ALTHOUGH A SLIGHT INCREASE
OVER THE PREVIOUS OFFICIAL HIGH FOR SATURDAY.
THIS WILL BE THE LAST OF THE WARMTH, HOWEVER, AS AN ARCTIC COLD
FRONT WILL BE CHARGING SOUTH LATE SATURDAY NIGHT THROUGH THE CENTRAL
PLAINS. THE TIMING OF THE FRONT LOOKS PRETTY CLOSE ON BOTH THE GFS
AND ECMWF MODELS, SO CONFIDENCE IS FAIRLY HIGH WITH A FRONTAL
PASSAGE SOMETIME VERY EARLY SUNDAY MORNING. WE WILL LIKELY SEE OUR
HIGH TEMPERATURE RIGHT AT SUNRISE SUNDAY MORNING WITH TEMPERATURES
FALLING INTO THE 20S OVER MUCH OF THE WEST CENTRAL/SOUTHWEST KANSAS
REGION BY MIDDAY AND INTO THE AFTERNOON. THE COOLER ECMWF MODEL IS
FAVORED GIVEN PAST PERFORMANCE IN SIMILAR TYPE SHALLOW ARCTIC
AIRMASS INTRUSIONS LIKE WHAT WILL BE SEEING SUNDAY. THE SUPERBLEND
GUIDANCE WE USE FOR MAX/MINT (IN THE DAY 4-7 FORECAST) WAS LOWERED,
IN FAVOR OF ADDING GREATER INFLUENCE FROM THE MOST RECENT AND
COOLER CONSRAW (CONSENSUS RAW TEMPERATURES FROM DETERMINISTIC MODELS
LIKE THE GFS, CANADIAN GEM, ECMWF). GIVEN HOW SHALLOW THIS AIRMASS
WILL BE SUNDAY, WE DO NOT ANTICIPATE ANY PRECIPITATION WITH THIS
FRONTAL PASSAGE CONSIDERING HOW ZONAL THIS FLOW WILL BE ALOFT AND
THE ABSENCE OF APPRECIABLE MOISTURE AND FRONTOGENESIS AT ~700MB LATE
SUNDAY INTO SUNDAY NIGHT.
IT WILL BE INTERESTING TO SEE HOW THE GLOBAL MODELS EVOLVE GOING
INTO NEXT WEEK, AS A DEEP TROUGH IS SUGGESTED COMING IN OFF THE
PACIFIC INTO SOUTHERN CALIFORNIA AND ADJACENT DESERT SOUTHWEST. THIS
WOULD ACTUALLY FAVOR SOME WARMING OF THE LOWER-MID TROPOSPHERE AND
AN EVENTUAL EROSION OF THE SHALLOW ARCTIC AIRMASS. THIS BATTLE IS
ALWAYS A BIG CHALLENGE IN THE FORECAST, SO THERE IS A LOT OF
UNCERTAINTY AS FAR AS TEMPERATURES (AND PRECIPITATION CHANCES) GO
EARLY NEXT WEEK
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 517 PM CST TUE NOV 25 2014
VFR CONDITIONS ARE EXPECTED GIVEN THAT THE 18Z BUFR SOUNDINGS
INDICATED ONLY MID LEVEL MOISTURE WILL ACCOMPANY AN UPPER LEVEL
DISTURBANCE AS IT CROSSING THE CENTRAL PLAINS OVERNIGHT. A COLD
FRONT LOCATED ACROSS EASTERN WYOMING AND WESTERN NEBRASKA AT 21Z
TUESDAY WILL DROP SOUTH AND CROSS SOUTHWEST KANSAS DURING THE
OVERNIGHT HOURS. NAM, NMM, HRRR, AND RAP WERE ALL IN DECENT
AGREEMENT WITH FRONTAL PASSAGE SO WILL STAY CLOSE TO THE TIMING OF
THESE MODELS OVERNIGHT. AS THIS FRONT PASSES THE SOUTHWESTERLY
WINDS AT 10 TO 15 KNOTS WILL SHIFT TO THE NORTH BETWEEN 03Z AND
05Z WEDNESDAY AT GCK AND HYS, AND THEN DDC AROUND 06Z WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 32 48 26 59 / 0 0 0 0
GCK 27 48 23 61 / 0 0 0 0
EHA 28 51 31 68 / 0 0 0 0
LBL 29 51 26 64 / 0 0 0 0
HYS 32 44 21 51 / 0 0 0 0
P28 35 50 25 56 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SUGDEN
LONG TERM...UMSCHEID
AVIATION...BURGERT
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
725 PM EST TUE NOV 25 2014
.UPDATE...
ISSUED AT 725 PM EST TUE NOV 25 2014
DID AN UPDATED MAINLY TO FRESHEN UP THE T AND TD GRIDS PER THE LATEST
OBS AND TRENDS. ALSO BUMPED UP THE SKY COVER QUICKER THROUGH THE
EVENING AS HIGH CLOUDS HAVE SPREAD IN QUICKLY FROM THE SOUTHWEST. THE
18Z RUNS HAVE COME IN WITH BEEFIER THOUGHTS ON SNOW AS BOTH THE GFS
AND NAM12 TAKE THE PCPN FURTHER WEST. THE GFS SEEMS TOO WARM AT THE
SFC FOR MUCH SNOW OR ACCUMULATION FOR LOCATIONS OUTSIDE OF OUR
CURRENT ADVISORY WITH ITS LATEST RUN. THE NAM12...ON THE OTHER
HAND...APPEARS TO GO OVERBOARD ON THE QPF AND THEREFORE SNOW OVER OUR
EASTERN COUNTIES. THERE REMAINS PLENTY OF FACTORS THAT WOULD HAMPER
THIS OCCURRENCE WITH CONVECTION TO THE SOUTH CUTTING OFF SOME OF THE
BEST MOISTURE FROM BEING TRANSPORTED INTO KENTUCKY AS CLEANLY AS
ENVISIONED BY THE OFF SYNOPTIC TIME RUN. NEVERTHELESS WILL BE
MONITORING THE RADAR TRENDS AND NEAR TERM MODELS FOR SIGNS THAT THE
CURRENT FORECAST REMAINS ON TRACK. TO THAT THOUGHT...THE LATEST HRRR
RUNS HAVE TRENDED ITS PCPN SHIELD FURTHER TO THE NORTHWEST BUT STILL
A FAR CRY FROM THE 6 HOURLY MODELS. THE UPDATED GRIDS HAVE BEEN SENT
TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 325 PM EST TUE NOV 25 2014
...ACCUMULATING SNOW EXPECTED OVER FAR EASTERN KENTUCKY TONIGHT INTO
WEDNESDAY MORNING...
19Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL INFLUENCING THE WEATHER OF
EASTERN KENTUCKY. THIS HAS PROVIDED PLENTY OF SUNSHINE AND GENERALLY
SOUTHWEST WINDS OF 5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS. THESE
CONDITIONS...ALONG WITH GOOD DRYING THROUGH EARLY AFTERNOON HAS SENT
TEMPERATURES WELL UP INTO THE 50S FOR MOST OF THE AREA...THOUGH
LOCATIONS NORTHWEST OF INTERSTATE 64 ARE LAGGING IN THE UPPER 40S. OF
NOTE ON THE SFC CHART IS AN AREA OF DEVELOPING LOW PRESSURE CROSSING
NORTHERN FLORIDA ON ITS WAY TO THE SOUTHEAST U.S. SEABOARD.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT THROUGH THE FIRST PART
OF THE SHORT TERM FORECAST. THEY ALL TAKE A STRONG SHORTWAVE
CURRENTLY BOTTOMING OUT OVER THE CENTRAL GULF COAST NORTHEAST INTO
THE SOUTHERN APPALACHIANS BY WEDNESDAY MORNING. IN ADDITION...A
COMPACT WAVE WILL BE DROPPING SOUTHEAST FROM THE NORTHERN PLAINS INTO
THE MID MISSISSIPPI VALLEY AND EVENTUALLY THROUGH THE TENNESSEE
VALLEY LATER WEDNESDAY NIGHT. THE MODELS ARE CLOSE ON THE TIMING OF
THIS BUT THE CORE OF THE ENERGY IS FURTHER SOUTH IN THE NAM...
ECMWF...AND GEM WHEN COMPARED TO THE GFS. WILL FAVOR THIS MORE
SOUTHERN TRACK AS SEEN IN THE CONSENSUS. IN GENERAL HAVE LEANED MOST
CLOSELY TO THE HIGHER RESOLUTION MODELS OF THE NAM12 AND HRRR...
THOUGH THE HRRR PCPN FIELDS SEEM TOO FAR SOUTHEAST AND SLOW LATER
TONIGHT.
SENSIBLE WEATHER WILL FEATURE A QUICK INCREASE IN CLOUD COVER FROM
THE SOUTHEAST AS THE COASTAL LOW STARTS TO TAKE SHAPE LATER THIS
EVENING. LOWER CLOUDS AND PCPN WILL START TO SPILL OVER THE SPINE OF
THE APPALACHIANS AND MOVE INTO OUR FAR EASTERN COUNTIES AROUND
MIDNIGHT. EXPECT TEMPERATURES TO WET BULB DOWN WHEN THE PCPN MOVES IN
AND TRANSITION THE RAIN TO SNOW IN THE HIGHER ELEVATIONS FIRST BUT
EVENTUALLY DOWN IN THE VALLEYS...AS WELL. THE HEAVIEST SNOW WILL FALL
IN THE HIGHER TERRAIN ALONG THE VIRGINIA BORDER WHERE AS MUCH AS A
QUARTER TO A THIRD OF AN INCH OF LIQUID WILL LIKELY OCCUR. THIS WILL
PROBABLY AMOUNT TO BETWEEN TWO AND THREE INCHES OF WET SNOW IN THE
HIGHER TERRAIN...ABOVE 2000 FEET AND AROUND AN INCH OR LESS
ELSEWHERE. HIGHER RIDGES BELOW 2000 FEET CAN EXPECT TO PICK UP
BETWEEN ONE AND TWO INCHES BY MIDDAY WEDNESDAY. HAVE SET UP THIS AREA
WITH A WINTER WEATHER ADVISORY FROM MIDNIGHT THROUGH NOON WEDNESDAY
FOR THIS PASSING EVENT. WITH THE POTENTIAL FOR LIGHT ACCUMULATIONS
IN THE COUNTIES IMMEDIATELY WEST OF THE ADVISORY WILL ALSO ISSUE AN
SPS ADDRESSING THIS MARGINAL CONCERN. OTHERWISE...THE COASTAL PULLS
OUT LATER WEDNESDAY WITH A BRIEF VISIT BY HIGH PRESSURE FOR EAST
KENTUCKY IN ITS WAKE. HOWEVER...THE NEXT DEVELOPING LOW WORKS IN FROM
THE NORTHWEST LATER THAT NIGHT CARVING ITS WAY THROUGH OUR SOUTHERN
COUNTIES INTO DAWN THURSDAY. THIS TOO WILL BRING SOME RAIN OR SNOW
TO PARTS OF THE AREA WITH SOME SLUSHY LIGHT SNOW ACCUMULATIONS
POSSIBLE MAINLY ON RIDGES AND GRASSY/ELEVATED SURFACES.
AGAIN USED THE BCCONSSHORT AS A STARTING POINT FOR T/TD/WINDS THROUGH
THE NEXT 24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME
MORE SIGNIFICANT TERRAIN BASED ADJUSTMENTS TONIGHT INTO WEDNESDAY IN
THE EXPECTED SNOW AREAS OF THE FAR EAST. AS FOR POPS...ENDED UP
CLOSE TO A BLEND OF THE MAV AND MET NUMBERS THROUGH THE PERIOD.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 354 PM EST TUE NOV 25 2014
SHORTWAVE ENERGY ROUNDING THE BASE OF THE TROUGH AND ASSOCIATED LOW
PRESSURE WILL BE MOVING EAST OF THE REGION WITH BEST POP CHANCES
ACROSS THE SE PORTIONS OF THE CWA. THIS WILL GENERALLY BE LIGHT
RAIN/SNOW SHOWERS AND DO NOT EXPECT MUCH QPF THROUGH THE DAY THURSDAY
AT THIS POINT. THIS SYSTEM SLIDES EAST ALLOWING FOR NW/W FLOW TO
SETUP ACROSS THE REGION AND THEREFORE HELD SLIGHT CHANCE IN FAR SE
INTO THE AFTERNOON.
SURFACE HIGH PRESSURE WILL SLOWLY SLIDE EAST THROUGH THE NIGHT
THURSDAY AND GENERALLY CRESTING ACROSS THE REGION EARLY FRIDAY. THIS
HIGH PRESSURE BUILDS EAST BRINGING RETURN SOUTHERLY FLOW TO EASTERN
KY WITH TEMPERATURES RISING INTO THE LOWER 50S SATURDAY. SATURDAY
AFTERNOON WE DO PRESENT SOME SLIGHT CHANCE SHOWERS ESPECIALLY ACROSS
THE FAR NORTH AS FRONTAL BOUNDARY GENERALLY STALLS ACROSS THE NORTH.
THIS QUASI-STATIONARY FRONT WILL KEEP THE WEATHER UNSETTLED THROUGH
THE PERIOD. THE QUESTION REALLY BECOMES HOW QUICKLY DOES THIS
BOUNDARY MOVE SOUTH...THAT SAID THE 12Z ECMWF IS MORE PROGRESSIVE
MOVING THIS FRONT SOUTH THAN THE 12Z GFS. RIGHT NOW WITH MODEL
DISCREPANCIES WILL KEEP BLEND POPS FOR THE MOST PART BUT WOULD THINK
THESE POPS WILL CONTINUE TO TREND UP ONCE MODELS COME INTO BETTER
ALIGNMENT. SATURDAY HIGHS ARE EXPECTED TO WARM INTO THE LOW TO MID
50S WITH TEMPERATURES MODIFYING INTO THE UPPER 50S TO LOWER 60S
THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 700 PM EST TUE NOV 25 2014
VFR CONDITIONS WILL CONTINUE THROUGH THE REST OF THE EVENING THOUGH
CIGS WILL TAKE SHAPE AND START TO LOWER DOWN TO 10K FEET BY
MIDNIGHT. A DEVELOPING LOW PRESSURE SYSTEM WILL SPREAD MOISTURE AND
LOWER CLOUDS OVER EASTERN KENTUCKY LATER TONIGHT...WITH CIGS FALLING
INTO THE MVFR RANGE IN THE EAST BY 08Z. IT STILL LOOKS LIKE WE SHOULD
SEE A GRADIENT IN THOSE LOWER CIGS WITH THE LOWEST (IFR/MVFR) IN THE
EAST...TRAILING BACK TO VFR IN THE WEST...THROUGH MID MORNING
WEDNESDAY. WE WILL ALSO SEE PRECIPITATION SPREAD INTO THE AREA...
MAINLY ACROSS SOUTHEASTERN KENTUCKY...AS A MIX OF RAIN AND
SNOW...LIKELY BECOMING ALL SNOW IN THE PRE-DAWN HOURS. THIS SNOW WILL
RESTRICT VISIBILITIES LATER TONIGHT AS WELL...PARTICULARLY AT KSJS
WHERE VIS COULD BE BELOW A MILE AT TIMES IN THE HEAVIER SNOW BANDS.
THE SNOW AND ANY RESTRICTIONS WILL END FOR THE TAF SITES FROM
SOUTHWEST TO NORTHEAST DURING THE MORNING WEDNESDAY. WINDS WILL BE
LIGHT AND VARIABLE THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST
WEDNESDAY FOR KYZ087-088-110-113-115-117>120.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
334 PM EST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 325 PM EST MON NOV 24 2014
19Z SFC ANALYSIS SHOWS A DEEP AREA OF LOW PRESSURE MOVING NORTHEAST
AWAY FROM THE GREAT LAKES. FROM THIS...A STRONG...BUT NOW DRY...COLD
FRONT IS PRESSING THROUGH EAST KENTUCKY. AHEAD OF THIS BOUNDARY...
STRONG SOUTHWEST WINDS ARE GUSTING ROUTINELY INTO THE 35 TO 45 MPH
RANGE WITH A FEW GUSTS EXCEEDING 50 MPH. THE OFFICE HAS RECEIVED
NUMEROUS REPORTS OF TREE DAMAGE AND POWER OUTAGES DUE TO THE WINDS.
THESE WINDS HAVE ALSO SUPPORTED TEMPERATURES IN THE UPPER 60S AND
LOWER 70S WITH DEWPOINTS IN THE MID 40S FOR MUCH OF THE AFTERNOON AND
THEY REMAIN THERE IN FAR EASTERN KENTUCKY. HOWEVER...ON THE OTHER
SIDE OF THE BOUNDARY THE WINDS REMAIN SOUTHWEST BUT ARE NOT QUITE AS
STRONG AND ARE BRINGING IN A DIFFERENT AIR MASS. AS SUCH...
TEMPERATURES DROPPING THROUGH THE 50S ARE NOW REACHING THE WESTERN
EXTENT OF THE CWA ALONG WITH DEWPOINTS HEADED FOR THE 30S. THE WINDS
REMAIN AT ADVISORY LEVEL IN THE EAST BUT ARE NOT QUITE THERE IN THE
WEST. AS THEY FURTHER SETTLE WE WILL LIKELY BE ABLE TO DROP THE
ADVISORY EARLY. FOR NOW...THOUGH...WILL CONTINUE TO LET IT RIDE FOR
THE ENTIRE CWA THROUGH 00Z.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE DEEP...AND FULL-
LATITUDE...TROUGH CROSSING THE OHIO VALLEY AND GREAT LAKES TODAY INTO
TUESDAY. HOWEVER...A SOUTHWESTERN EXTENT OF THE LARGER TROUGH WILL
REMAIN STRETCHED INTO SOUTHWESTERN TEXAS AND IT IS THIS SECTION
THAT TIGHTENS UP AND MOVES EAST LATER TUESDAY. THE SOUTHERN
ENERGY...IN CONJUNCTION WITH SOME MOVING THROUGH THE MID MISSISSIPPI
VALLEY WILL SWEEP THROUGH THE DEEP SOUTH AND ACROSS THE TENNESSEE
VALLEY ON TUESDAY NIGHT. OF NOTE ALSO...A CLUSTER OF ENERGY WILL BE
RIDING SOUTHEAST THROUGH THE CENTRAL PLAINS AT DAWN WEDNESDAY. WITH
THE MODEL AGREEMENT HAVE FAVORED THE NAM12 AND HRRR INITIALLY AND
THEN A BLEND OF THE ECMWF AND NAM12 FOR WX DETAILS INTO WEDNESDAY
MORNING.
SENSIBLE WEATHER WILL FEATURE WINDS SETTLING DOWN THIS EVENING FROM
WEST TO EAST AS THE GRADIENT RELAXES. IT WILL ALSO MEAN A COOLER
EVENING...BUT NOWHERE NEAR AS COLD AS IT HAS BEEN OF LATE. TUESDAY
WILL CERTAINLY BE A COOLER DAY BUT A QUIETER ONE AS WE WILL BE
BETWEEN SYSTEMS. A DEVELOPING SFC LOW ALONG THE SOUTHEAST COAST WILL
START TO SPREAD HIGH CLOUDS INTO THE AREA FROM THE SOUTHEAST BY
EVENING. LOOK FOR THESE TO THICKEN AND LOWER WITH TIME THAT NIGHT AS
THE SOUTHEAST PORTION OF THE CWA IS BRUSHED BY THE PCPN SHIELD FROM
THIS NASCENT COASTAL SYSTEM. HAVE CONTINUED THE THREAT OF RAIN OR
SNOW PRIMARILY IN THE COUNTIES BORDERING VIRGINIA...BUT NOT
ANTICIPATING MUCH IN THE WAY OF ACCUMULATIONS EXCEPT PERHAPS A TOUCH
OF IT JUST ON THE PEAK OF BLACK MOUNTAIN.
USED THE BCCONSSHORT AS A STARTING POINT FOR T/TD/WINDS THROUGH THE
NEXT 24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME MINOR
TERRAIN BASED ADJUSTMENTS TONIGHT AND TUESDAY NIGHT TO THE LOWS. AS
FOR POPS...ENDED UP CLOSE TO A BLEND OF THE MAV AND MET NUMBERS FOR
TUESDAY NIGHT AND DRY OTHERWISE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 332 PM EST MON NOV 24 2014
THERE WILL BE A DEVELOPING SURFACE LOW OFF THE CAROLINA COAST BEGINNING
THE PERIOD AND THE FRONTOGENESIS IS AIDED BY A BROAD TROUGH/EMBEDDED
SHORTWAVE ENERGY SWING THROUGH THE EASTERN U.S. THOROUGH THE PERIOD.
THIS COASTAL LOW IS EXPECTED TO MOVE NE ALONG THE ATLANTIC SEABOARD
WEDNESDAY INTO THURSDAY. ANOTHER EMBEDDED SHORTWAVE WILL EXIT THE
UPPER PLAINS AND DROP SE INTO THE OHIO AND TENNESSEE VALLEYS
WEDNESDAY NIGHT INTO THURSDAY. SURFACE HIGH WILL BUILD EAST LATER
THURSDAY INTO FRIDAY. UPPER LEVELS WILL BEGIN TO BECOME MORE ZONAL
WITH SURFACE FRONT DEVELOPING ACROSS PORTIONS OF THE OHIO VALLEY
GOING INTO SUNDAY INTO MONDAY.
SENSIBLE WEATHER... GIVEN SYNOPTIC SETUP LOW PRESSURE MOVING ALONG
THE ATLANTIC COAST COULD BRING SLIGHT TO CHANCES MAINLY RAIN/SNOW
SHOWERS ACROSS THE EASTERN AND SOUTHEASTERN PORTIONS OF THE REGION
EARLY WEDNESDAY...BEFORE TRANSITIONING TO RAIN SHOWERS THROUGH THE
DAY WEDNESDAY. THIS LOW WILL TRACK NORTH AND EAST WHILE AFOREMENTIONED
DISTURBANCE DROPS SE ACROSS THE REGION WEDNESDAY NIGHT. THERE IS
BETTER AGREEMENT WITH MODELS SO DID OPT TO BRING POPS UP A BIT FOR
THIS SYSTEM. THIS SYSTEM IS EXPECTED TO BRING SLIGHT TO CHANCE
RAIN/SNOW SHOWERS ACROSS EASTERN KY WEDNESDAY NIGHT. THURSDAY MUCH OF
THE REGION WILL WARM UP SO EXPECT MOST OF THE ACTIVITY WILL
TRANSITION TO RAIN SHOWERS BEFORE EXITING THE REGION LATE IN THE DAY
ON THURSDAY. AFTER THIS IT IS EXPECTED TO BE QUIET AND MOSTLY CLEAR
CONDITIONS TIL WE GET TO THE SATURDAY TIME FRAME. DURING THIS TIME
MODELS ARE NOT IN GOOD AGREEMENT ON TIMING/DEVELOPMENT OF NEXT
SYSTEM. RIGHT NOW THINKING WILL ONLY GO WITH SLIGHT CHANCES OF RAIN
SHOWERS SATURDAY...THEN TRANSITION TO SLIGHT/CHANCE RAINS SHOWERS AS
FRONT SLOW PROGRESSES SOUTH ACROSS THE REGION GOING INTO SUNDAY AND
MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 105 PM EST MON NOV 24 2014
A STRONG...BUT MOSTLY DRY...COLD FRONT IS CROSSING THROUGH EASTERN
KENTUCKY. FROM THIS...LITTLE MORE THAN A SPRINKLE WILL BE POSSIBLE AT
THE TAF SITES THROUGH THE REST OF THE DAY. MID LEVEL CIGS WILL
EVENTUALLY BREAK UP BY LATE IN THE DAY...BUT NOT BEFORE A FEW MVFR
CIGS DRIFT THROUGH THE NORTHERN SITES...POST FRONTAL. LATE TONIGHT
AND THROUGH THE DAY TUESDAY THE SKIES WILL BE VFR. THE MAIN AVIATION
IMPACT WILL BE STRONG AND GUSTY SOUTHWEST WINDS THROUGH EARLY
EVENING. SOUTHWEST WIND GUSTS ARE OCCASIONALLY REACHING 40 KNOTS IN
PLACES THIS AFTERNOON WITH THIS EXPECTED TO CONTINUE FOR AT LEAST
SEVERAL MORE HOURS. WHILE WINDS SHOULD DIMINISH INTO THE
EVENING...FOLLOWING FROPA...THEY COULD REMAIN GUSTY IN SOME PLACES
THROUGH MIDNIGHT BEFORE BECOMING LIGHT AND VARIABLE INTO THE DAY
TUESDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR KYZ044-050>052-
058>060-068-069-079-080-083>088-104-106>120.
&&
$$
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
557 AM EST MON NOV 24 2014
.SYNOPSIS...
STRONG LOW PRESSURE WILL CROSS THE GREAT LAKES AND MOVE NORTHEAST
INTO QUEBEC PROVINCE TODAY. A COLD FRONT WILL CROSS THE REGION
TONIGHT...WITH A SECOND COLD FRONT CROSSING THE REGION TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
555 AM UPDATE...THE RAIN`S ON ITS WAY...CURRENTLY MOVING INTO FAR
WESTERN MAINE. TEMPERATUERES LOOK TO BE ABOVE FREEZING JUST ABOUT
EVERYWHERE, EXCEPT A FEW COLD SPOTS IN CENTRAL PENOBSCOT/SOUTHERN
PISCATAQUIS COUNTY. EXPECT TEMPERATURES TO CONTINUE TO RISE PRIOR
TO THE RAIN`S ARRIVAL (TEMPS ALREADY IN THE LOWER 40S AT KBGR), SO
DON`T ANTICIPATE MUCH, IF ANY, FROZEN PRECIPITATION TO OCCUR. THE
FORECAST HAS THIS COVERED, SO NO MAJOR CHANGES WERE NEEDED.
PREVIOUS DISCUSSION...LOW PRESSURE CURRENTLY CENTERED NEAR
SOUTHERN LAKE MICHIGAN WILL CONTINUE TO LIFT NORTHEAST INTO
ONTARIO TODAY AND EVENTUALLY INTO QUEBEC THIS EVENING, DEEPENING
AS IT DOES SO. MILD AIR WILL SPREAD INTO NORTHERN NEW ENGLAND ON
THE STRONG SOUTHWEST FLOW AHEAD OF THE LOW AND ITS ATTENDANT
OCCLUDED FRONT. THE SWATH OF FRONTAL/WARM ADVECTION RAIN IS MOVING
INTO EASTERN NEW YORK AND WESTERN NEW ENGLAND EARLY THIS MORNING
AND WILL CONTINUE TO PUSH EASTWARD THROUGH THE DAY. THIS SYSTEM IS
A FAST MOVER, SO THE FRONTAL PASSAGE WILL BE A QUICK ONE. EXPECT
THE RAIN TO MOVE INTO WESTERN SECTIONS OF OUR FORECAST AREA BY
MID-MORNING AND TO EXIT INTO NEW BRUNSWICK BY MID-EVENING, AS
INDICATED BY THE LATEST HRRR MODEL GUIDANCE. THE FRONT ITSELF
WON`T MOVE THROUGH UNTIL A BIT LATER IN THE EVENING, AND WITH
PLENTY OF LOW-LEVEL MOISTURE AROUND, THERE`LL STILL BE THE CHANCE
FOR FOG AND DRIZZLE THROUGH MIDNIGHT OR SO. RAINFALL TOTALS WILL
BE A QUARTER TO A HALF INCH, WITH SOME OF THE UPSLOPE REGIONS IN
THE CENTRAL HIGHLANDS GETTING UP TO THREE-QUARTERS OF AN INCH. THE
OTHER CONCERN WITH THIS SYSTEM IS THE POTENTIAL FOR GUSTY WINDS,
ESPECIALLY ALONG THE DOWNEAST COAST. GUSTS OF 40 MPH WILL BE
POSSIBLE, WHICH MAY CAUSE SOME DOWNED LIMBS OR TREES AND PERHAPS
ISOLATED POWER OUTAGES. TEMPERATURES WILL BE QUITE MILD TODAY AND
TONIGHT; HIGHS WILL RANGE FROM AROUND 50 TO AROUND 55. GUIDANCE IS
EVEN INDICATING THAT TEMPERATURES WILL HOLD STEADY OR EVEN RISE
OVERNIGHT, ONLY FALLING LATE ONCE THE FRONT HAS MOVED THROUGH.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
COLD LLVL ADVCN WILL BE CONTG THRU TUE BEHIND A SECONDARY COLD
FRONT. SKIES WILL BEGIN MCLR TO PTLY CLDY TUE MORN...WITH MORE IN
THE WAY OF BKN-OVC SC AND A SLGT CHC OF SN SHWRS FOR NRN PTNS OF
THE FA LATE TUE INTO TUE NGT AS WHATS LEFT OF AN UPPER TROF SLIDES
EWRD MSLY N OF THE REGION. TEMPS WILL HOLD STEADY THE FIRST FEW
HRS OF TUE MORN...THEN BEGIN TO FALL...SPCLY ACROSS THE N. OVRNGT
TEMPS WILL BE COLDER THAN MON NGT...BUT STILL ABV NORMAL FOR LOWS
ERLY WED MORN.
WED WILL BEGIN PTLY CLDY MOST LCTNS...BUT HI AND MID CLDNSS FROM
THE SFC LOW ADVCG NEWRD FROM THE SE STATES WILL OVRSPRD THE REGION
FROM SW TO NE DURG THE DAY. THE LEADING EDGE OF PRECIP WILL REACH
DOWNEAST AREAS BY MID AFTN AND AT LEAST INTO E CNTRL PTNS OF THE
REGION BY THE BEGINNING OF EVENING. HI TEMPS WED WILL BE ABOUT 10
TO 15 DEG COLDER THAN HI TEMPS TUE. PRECIP MAY BRIEFLY BEGIN AS
LGT RN OR A MIX OF LGT RN/SN OVR DOWNEAST AREAS...BUT EVAPORATIONAL
AND DYNAMIC COOLING FROM ALF SHOULD CHG ANY RN TO ALL SN BY EVE...
XCPT PERHAPS ALG THE IMMEDIATE COAST AND OUTER ISLANDS WHERE RN OR
MIXED RN AND SNOW COULD ON UNTIL LATE TNGT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
WE NOTED THAT THE 00Z DTMNSTC ECMWF HAS SHIFTED THE TRACK OF THE
COASTAL LOW FURTHER E THAN RECENT PAST RUNS...NOW TAKING THE LOW
INTO THE ERN BAY OF FUNDY. MEANWHILE...THE 00Z DTMNSTC GFS RUN IS
ALSO A SLIGHTLY MORE E WITH THE TRACK OF THIS SYSTEM COMPARED TO
YSTDY ATTM...ALG WITH THE CORRESPONDING GFS ENSM...BOTH TAKING
THE LOW ALG THE S COAST OF NOVA SCOTIA BY THU MORN. IF THE GFS...
WHICH REPRESENTS THE MIDDLE OF MODELS WITH REGARD TO THE TRACK IS
CORRECT...THE BEST POTENTIAL OF HVY SNFL WED NGT INTO THU MORN
WOULD BE OVR DOWNEAST TO PERHAPS AS FAR N AS E CNTRL PTNS OF THE
FA. GIVEN THE UNCERTAINTIES WITH THIS SYSTEM...WHICH INCLUDES
DIFFICULTIES OF GAGING THE AMPLITUDE OF THE SRN JET STREAM S/WV
SUPPORTING THE SFC LOW AND THE POTENTIAL OF ANY PHASING FROM NRN
JET STREAM S/WV ENERGY...IT IS TO ERLY TO ISSUE ANY WNTR STM
WATCHES ATTM...AND IT IS POSSIBLE THAT THE CONSENSUS MODEL TRACK
COULD SHIFT A LITTLE FURTHER E WITH FUTURE MODEL RUNS. IN ANY
EVENT...WE WILL CONT TO ADVERTISE THIS EVENT IN OUR HAZ WX OUTLOOK
AND HIGHLIGHT A BETTER POTENTIAL OF POSSIBLE WATCHES FOR SPCLY
DOWNEAST AND E CNTRL PTNS OF THE REGION.
OTHERWISE...ANY STEADY SNFL OVR PTNS OF THE FA THU MORN SHOULD
WIND DOWN TO SCT SN SHWRS THU AFTN AS THE SFC LOW TRACKS ENE FROM
NOVA SCOTIA. LEFT OVR LLVL MOISTURE FROM THE EXITING SFC LOW AND
A FOLLOW-UP S/WV FROM S CNTRL CAN WILL KEEP THE CHC OF SN SHWRS
SPCLY FOR THE N HLF OF THE FA THU NGT INTO FRI BEFORE SKIES
FINALLY BECOME CLR TO PTLY CLDY FRI NGT. SEMI-ARCTIC AIR FOLLOWS
THE CAN S/WV FOR FRI NGT. ANOTHER S/WV FROM CNTRL CAN WILL LIKELY
BRING MORE SN SHWR ACTIVITY TO THE REGION LATER SAT INTO SUN AS IT
APCHS AND TRACKS MSLY N OF THE REGION. ENOUGH RETURN SRLY LLVL
WARM ADVCN COULD OCCUR FOR SN SHWRS TO MIX WITH OR CHG TO RN SHWRS
OVR THE S HLF OF THE REGION SUN BEFORE A STRONG COLD FRONT CROSSES
THE REGION BY LATE SUN.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
NEAR TERM: MVFR CONDITIONS ARE EXPECTED TO PREVAIL THIS MORNING,
THEN GIVE WAY TO IFR BY EARLY AFTERNOON AS RAIN SPREADS INTO THE
REGION. THE RAIN WILL TAPER OFF TO SHOWERS BY 00Z, BUT LOWERED
CEILINGS AND REDUCED VISIBILITIES WILL LINGER THROUGH 06Z DUE TO
FOG AND DRIZZLE.
SHORT TO LONG TERM: VFR XPCTD TUE THRU WED MORN...WITH MVFR SC
CLGS POSSIBLE FAR NRN TAF SITES FROM LATE TUE INTO WED.
OTHERWISE...IFR-LIFR IN SN WILL SPREAD NEWRD ACROSS DOWNEAST
SITES LATE WED AND CONT NEWRD THRU THE REMAINDER OF THE TAF SITES
OVRNGT WED. IFR IN SN WILL CONT THU MORN ACROSS NRN TAF SITES...BUT
WILL IMPROVE TO MVFR OVR DOWNEAST SITES. CONDITIONS WILL THEN
IMPROVE TO MVFR NRN TAF SITES IN SC CLGS AND SN SHWR VSBYS THU
AFTN THRU FRI AND IMPROVE TO VFR OVR DOWNEAST SITES.
&&
.MARINE...
NEAR TERM: A GALE WARNING REMAINS IN EFFECT FOR TODAY AND TONIGHT. LOW
PRESSURE MOVING UP WELL TO THE NORTHWEST OF THE WATERS WILL ALLOW
WINDS AND WAVES TO BUILD THIS MORNING, WITH GUSTS TO AROUND 40 KT
POSSIBLE. SEAS WILL BUILD TO 8 TO 12 FEET.
SHORT TO LONG TERM: SCA WINDS AND WV HTS WILL CONT TUE WITH WSW
WIND FETCH AND THEN TAPER TUE NGT. AFT A BRIEF BREAK WED MORN...
WINDS AND SEAS WILL AGAIN INCREASE TO AT LEAST SCA RANGE BY LATE
WED WITH THE APCH OF THE COASTAL LOW FROM THE SW AND CONT OVRNGT
WED INTO THU AS THE LOW TRACKS TOWARD THE MARITIMES. GALE
CONDITIONS ARE POSSIBLE...BUT GIVEN UNCERTAINTIES WITH THE
TRACK AND STRENGTH OF THIS LOW...ITS TO EARLY TO COMMIT WITH
GALE FORCE WINDS WED NGT AND THU ATTM. KEPT CLOSE TO WW3 WV
GUIDANCE FOR WV HTS THIS UPDATE.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST TUESDAY FOR
ANZ050>052.
&&
$$
NEAR TERM...HASTINGS
SHORT TERM...VJN
LONG TERM...VJN
AVIATION...HASTINGS/VJN
MARINE...HASTINGS/VJN
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
957 PM EST TUE NOV 25 2014
.SYNOPSIS...
LOW PRESSURE SYSTEM IS EXPECTED TO DEVELOP AND RIDE NORTHWARD
ALONG THE COAST ON WEDNESDAY...BRINGING ACCUMULATING SNOW TO AREAS
SOUTH AND EAST OF PITTSBURGH. A SECOND WEAKER SYSTEM WILL USHER IN
COLDER TEMPERATURES AND LINGERING SNOW SHOWER CHANCES THROUGH THE
END OF THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
WITH 945PM UPDATE...HAVE SLOWED UP ARRIVAL OF SNOW BY A COUPLE OF
HOURS IN THE RIDGES CONSIDERING 00Z NAM AND 01Z HRRR SHOW A MUCH
SLOWER ARRIVAL OF PRECIPITATION IN THOSE LOCATIONS. THIS CHANGE IS
MINOR ENOUGH THAT NO CHANGES TO THE START OF ADVISORIES/WARNINGS
WAS MADE. OTHER NOTICEABLE CHANGE IN THE FORECAST WAS TO INCREASE
POPS OUTSIDE OF THE ADVISORY/WARNING AREA ON WEDNESDAY. THIS WAS
DONE TO BETTER REFLECT CONFIDENCE OF WHERE SNOWFALL WILL
OCCUR...WITH ONLY VERY MINOR CHANGES MADE TO THE INHERITED
SNOWFALL FORECAST. PREVIOUS DISCUSSION FOLLOWS.
QUIET WEATHER IN THE INTERIM AS A SURFACE LOW PRESSURE SYSTEM
BEGINS TO DEVELOP ALONG THE SOUTHEAST COAST THIS EVENING. THIS LOW
WILL THEN LIFT NORTHEASTWARD WITH THE HELP OF A DIGGING UPPER
LEVEL SHORTWAVE OVER THE PLAINS AND A STRENGTHENING UPPER LEVEL
JET....RIDING ALONG THE COLD FRONT THAT CROSSED THE REGION
YESTERDAY. TEMPERATURES WILL DROP INTO THE UPPER 20S AND LOWER
30S TONIGHT ACROSS THE REGION.
THE GENERAL MODEL CONSENSUS IS THAT SNOW WILL BEGIN TO OVERSPREAD
THE REGION EARLY TOMORROW MORNING FROM SOUTHEAST TO NORTHWEST AS
THE LOW IS LIFTED NORTHWARD. THE NAM SEEMS TO BE THE
OUTLIER...WITH VERY HIGH OMEGA VALUES AND THUS SNOWFALL
ACCUMULATIONS IN COMPARISON TO ALL OF THE OTHER MODELS...AND
SEVERAL RUNS OF THE MODELS. WITH THAT BEING SAID...THE QPF VALUES
HAVE INCREASED A BIT AMONG ALL OF THE MODELS...WHICH EVEN WITH
MODEST SNOW RATIOS LEADS TO WARNING CRITERIA SNOW IN THE HIGHER
ELEVATIONS OF GARRETT...PRESTON...AND TUCKER COUNTIES AND JUST
EXCEEDING WARNING CRITERIA IN THE CHESTNUT AND LAUREL RIDGES. A
BIT OF AN EXPANSION WESTWARD IN THE TRACK HAS ALSO LEAD TO THE
ISSUANCE OF AN ADVISORY FOR 2-4 INCHES IN THE COUNTIES IMMEDIATELY
ADJACENT TO THE WARNING...WITH LESSER AMOUNTS EXPECTED FURTHER
NORTH AND WEST.
IT IS EXPECTED THAT THE BULK OF THE SNOWFALL WILL BE OVER BY LATE
AFTERNOON AS THE SYSTEM PULLS OFF TO THE EAST. WITH WETBULBING
EXPECTED...HIGH TEMPERATURES WILL STRUGGLE TO MOVE OUT OF THE LOW
TO MID 30`S TOMORROW.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
DIGGING SHORTWAVE INTO THE WESTERN GREAT LAKES WILL BRING LIGHT SNOW
SHOWERS EARLY THURSDAY...WITH A TRANSITION TO LAKE ENHANCED SNOW
SHOWERS LATER THURSDAY AFTERNOON AND THURSDAY NIGHT. MODELS STILL
PROG 850MB TEMPS TO FALL TO NEAR -10C BY THURSDAY NIGHT AND WITH A
DECENT LAKE FETCH EXPECT SOME LIGHT ACCUMULATIONS IN THE RIDGES AND
I-80 CORRIDOR. TEMPERATURES WILL BE AROUND 10 DEGREES BELOW SEASONAL
AVERAGE. DRY HIGH PRESSURE WILL MOVE ACROSS THE REGION FRIDAY WITH
CONTINUED COLD TEMPERATURES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A STREAM OF MOISTURE FROM THE CANADIAN ROCKIES WILL KEEP CLOUDS AND
PRECIPITATION CHANCES IN THROUGH THE WEEKEND AS NW FLOW HOLDS INTO
EARLY SUN. HIGH PRESSURE WILL SLIDE SOUTH INTO THE NRN PLAINS OVER
THE LATTER PART OF THE WEEKEND...DISLODGING A WEAK COLORADO LOW WITH
RELATIVELY LOW MOISTURE INTO OUR AREA. WHILE THIS MEANS MORE LIGHT
PRECIPITATION...THE GOOD NEWS IS A TRANSITION TO SWERLY FLOW AND
OVERALL WARMING INTO NEXT WEEK. MODELS HAVE MADE REMARKABLE PROGRESS
IN CONSISTENCY OVER THE LAST 24HRS LENDING TO HIGHER CONFIDENCE IN
THE EXTENDED TRENDS.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDS ARE EXPD THIS EVE...EXCEPT FOR FKL WHERE PERSISTENT MVFR
SC IS TRAPPED UNDER A TEMPERATURE INVERSION. OTRW...EXP CONDS TO
DETERIORATE TO MVFR AND EVENTUALLY IFR FOR MOST PORTS NR AND E OF
THE OH/PA BORDER AS LOW PRES ADVNS UP THE E COAST AND SPREADS SNW
INTO THE RGN. THE SNW SHOULD EXIT LT WED AS THE MOVES FURTHER
NEWD...THOUGH MVFR CIGS ARE EXPD TO CONT.
OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
PERIODIC RSTRNS ARE PSBL THRU THE WKEND WITH SVRL FAST MOVG
DISTURBANCES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WARNING FROM 4 AM TO 6 PM EST WEDNESDAY FOR
MDZ001.
OH...NONE.
PA...WINTER STORM WARNING FROM 4 AM TO 6 PM EST WEDNESDAY FOR
PAZ074-076.
WINTER WEATHER ADVISORY FROM 4 AM TO 6 PM EST WEDNESDAY FOR
PAZ023-073-075.
WV...WINTER STORM WARNING FROM 4 AM TO 6 PM EST WEDNESDAY FOR
WVZ023-041.
WINTER WEATHER ADVISORY FROM 4 AM TO 6 PM EST WEDNESDAY FOR
WVZ021-022.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
608 PM EST TUE NOV 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 450 PM EST TUE NOV 25 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN AMPLIFIED PATTERN OVER
NAMERICA WITH RIDGING ALONG/JUST OFF THE W COAST...A TROF EXTENDING
FROM N OF HUDSON BAY TO TX AND A RIDGE JUST OFF THE EAST COAST.
SHORTWAVE THAT PROVIDED WIDESPREAD SYNOPTIC SNOW AS WELL AS LAKE
ENHANCED SNOW ACROSS THE FCST AREA LAST NIGHT HAS SHIFTED NE INTO
QUEBEC. UPSTREAM...NEXT SHORTWAVE IS DIVING SE INTO THE DAKOTAS. A
LESS DEFINED SHORTWAVE TROF IS FARTHER N OVER NRN PORTIONS OF
MANITOBA/SASKATCHEWAN. DRYING AIR MASS...LOWERING INVERSION AND LOW
LEVEL WINDS BECOMING MORE ANTICYCLONIC WITH SFC HIGH PRES THAT IS
NOW NOSING INTO WRN UPPER MI HAVE RESULTED IN A STEADY DIMINISHING
TREND/SHIFTING OF LINGERING LES THIS AFTN. IN FACT...OVER THE
W...THERE MAY NOT BE MUCH MORE THAN SCT FLURRIES REMAINING. LAKE
EFFECT CLOUD COVER IS ALSO DIMINISHING WITH CLR SKIES NOW BEING
NOTED AROUND KIWD. TO THE W...CLOUDS IN ADVANCE OF AFOREMENTIONED
SHORTWAVES ARE SLOWLY MOVING ACROSS NRN MN.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LES TRENDS TONIGHT...MIN
TEMPS TONIGHT WITH A PROBABLE PERIOD OF CLR/PARTLY CLOUDY SKIES IN
MANY AREAS AND THEN NEXT ROUND OF HEAVIER LES THAT WILL BEGIN TO
ENTER THE PICTURE WED AFTN AS SHORTWAVE TROF SWINGS SE TOWARD THE
UPPER LAKES.
TONIGHT...ARRIVAL OF WEAK SFC HIGH PRES RIDGE COMBINED WITH
STRENGTHENING LAND BREEZES WILL CONTINUE TO SHIFT LINGERING LES
OFFSHORE. OVER THE E...SHIFTING LES SHOULD BE OFFSHORE NO LATER THAN
AROUND MIDNIGHT. OVER THE W...ALTHOUGH THERE IS PROBABLY NOT MUCH
MORE THAN FLURRIES CURRENTLY REMAINING...NOCTURNAL COOLING AND LAND
BREEZE DEVELOPMENT RESULTING IN INCREASING CONVERGENCE SHOULD FAVOR
SOME REDEVELOPMENT OF LES DURING THE NIGHT. AMONG THE HIGH RES
MODELS...THERE IS DISAGREEMENT IN WHETHER SE MOVING SFC TROF WILL
SINK FAR ENOUGH S TO KEEP LES OVER THE KEWEENAW. AT THIS POINT...
BELIEVE SW FLOW ENHANCED BY LAND BREEZE WILL PUSH LES OFFSHORE...BUT
THERE IS ENOUGH UNCERTAINTY TO MAINTAIN SOME SCT -SHSN WORDING OVER
THE NRN PORTION OF THE KEWEENAW OVERNIGHT. AS FOR TEMPS...BASED ON
SATELLITE IMAGERY...IT LOOKS LIKE THERE WILL BE A DECENT PERIOD OF
CLEAR TO PARTLY CLOUDY SKIES TONIGHT OVER MUCH OF THE AREA. WITH
LIGHT WINDS AND PRECIPITABLE WATER 40-55PCT OF NORMAL...FAVORED THE
LOW END OF GUIDANCE. TEMPS SHOULD PLUMMET RAPIDLY THIS EVENING WHERE
SKIES ARE CLEAR...AND EXPECT TRADITIONAL COLD SPOTS TO FALL TO
AROUND -5F. HOWEVER...GIVEN THE SLOW ADVANCE OF UPSTREAM CLOUDS...
CLOUDS MAY BE SLOWER TO ARRIVE THAN CURRENTLY FCST. COMBINED WITH
FRESH SNOW COVER...COULD EASILY SEE TEMPS FALL TO -10F OR LWR IN THE
USUAL COLD SPOTS.
SHORTWAVE CURRENTLY MOVING INTO THE DAKOTAS WILL CONTINUE TO DROP SE
TOWARD THE TENNESSEE VALLEY TONIGHT/WED AND WILL HAVE NO INFLUENCE
HERE AS IT PASSES WELL S OF UPPER MI. OF CONCERN IS THE FOLLOWING
SHORTWAVE TROF WHICH WILL SWING SE AND EXTEND FROM JAMES BAY TO MN
BY 00Z THU. AS HEIGHT FALLS/MODEST DEEP LAYER FORCING PER QVECTORS
OVERSPREAD THE RELATIVELY WARM WATERS OF LAKE SUPERIOR...SFC TROF
MOVING OVER THE LAKE WILL SHARPEN UP...RESULTING IN INCREASING
CONVERGENCE AND INTENSIFYING LAKE ENHANCED SNOW ALONG/NEAR TROF.
EXPECT THIS TROF TO REACH THE KEWEENAW DURING THE MORNING AND THE W
IN THE AFTN. TROF PROBABLY WON`T REACH NCNTRL UPPER MI UNTIL
EVENING. NE ORIENTATION OF THE WINDS ACROSS THE KEWEENAW AFTER
TROF PASSAGE WON`T BE ESPECIALLY FAVORABLE FOR PERSISTENT HEAVIER
LAKE ENHANCED SNOW AFTER THE MAIN MDT/HVY SNOW BAND ALONG TROF
SHIFTS S. FARTHER S...SHARPER LOW-LEVEL CONVERGENCE AND BETTER
UPSLOPING IS EXPECTED INTO ONTONAGON/GOGEBIC COUNTIES...AND THIS IS
INDICATED IN MODEL GUIDANCE IN LOW-LEVEL OMEGA FIELDS. WIND FLOW
SUGGESTS LAKE NIPIGON PRECONDITONING WILL ALSO COME INTO PLAY OVER
THE FAR W. WITH THESE FAVORABLE CONDITIONS CONTINUING INTO THE WED
NIGHT...WILL HOIST A LAKE EFFECT SNOW ADVISORY FOR ONTONAGON/GOGEBIC
STARTING AT 20Z WED. IN GENERAL...A QUICK COUPLE OF INCHES OF SNOW
WILL PROBABLY OCCUR AS THE TROF MOVES ONSHORE OVER THE W.
ELSEWHERE...SOME -SN SHOULD GRADUALLY OVERSPREAD THE REST OF WRN
UPPER MI IN THE AFTN. TO THE E...IT APEARS WINDS WILL BACK
SUFFICIENTLY TO BRING SOME LES OFF LAKE MICHIGAN INTO THE FAR ERN
FCST AREA IN THE AFTN. WINDS ARE LIGHT/CONVERGENCE WEAK...SO NOT
EXPECTING MUCH WITH THE LES OFF LAKE MI WED (LESS THAN 1 INCH).
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 457 PM EST TUE NOV 25 2014
MAIN FCST CONCERNS IN THE LONG TERM WL FOCUS ON LES POTENTIAL FOR
WED NIGHT INTO THANKSGIVING AND NEED FOR HEADLINES AT SENSITIVE
TRAVEL TIME. ANOTHER ROUND OF SN WL BE POSSIBLE ON FRI/FRI NIGHT
WITH DVLPG ISENTROPIC ASCENT UNDER AN UPPER AIR PATTERN THAT WL
SHIFT TO A PROGRESSIVE...ZONAL FLOW BY THE WEEKEND. WELL BLO NORMAL
TEMPS WITH SOME RECORD LO MAX TEMPS ON THANKSGIVING WL GIVE WAY TO
MUCH WARMER WX ON SAT. ALTHOUGH SOME COLDER AIR WL RETURN FOR SUN
INTO MON...A WARMER SW FLOW ON THE WRN FLANK OF HI PRES SHIFTING TO
THE E WILL DVLP ON TUE UNDER THIS PROGRESSIVE PATTERN.
WED NGT...STEADY N BACKING NNW WIND IN THE WAKE OF PASSING NRN
STREAM SHRTWV IS FCST TO ADVECT COLDER AIR INTO THE UPR LKS WITH H85
TEMPS FALLING AS LO AS -18C OVER THE KEWEENAW BY 12Z THU...A FVRBL
SETUP FOR LES. EXPECT A PERIOD OF SOME HEAVIER LK ENHANCED SN IN THE
FAVORED SN BELTS WHEN AREA OF DPVA/DEEP LYR QVECTOR CNVGC/UVV/DEEP
MSTR ASSOCIATED WITH THE PASSING DISTURBANCE COINCIDES WITH FVRBL
UPSLOPE...WEAKLY CYC N FLOW. AREAS OVER ONTONAGON/GOGEBIC IN THE
EVNG AND MARQUETTE/ALGER COUNTIES IN THE LATER EVNG/EARLY OVERNGT
APPEAR TO BE MOST FAVORED TO SEE HEAVIER SN. ENHANCEMENT FACTOR FOR
HEAVIER SN TOTALS INCLUDE FAIRLY DEEP DGZ UP TO 4K FT. ALTHOUGH THE
SHARPEST UVV IS FCST TO BE JUST BLO THE DGZ MUCH OF THE TIME...THERE
WL BE SOME UVV IN THIS ZONE THAT SHOULD ALLOW SN/WATER RATIOS UP TO
20-25:1. ONE NEGATIVE APPEARS TO BE THE ABSENCE OF SHARP CYC FLOW/
PERSISTENT LLVL CNVGC. ALTHOUGH THE LK ENHANCEMENT WL NOT BE A
PLAYER WELL INLAND FM LK SUP...DYNAMIC FORCING SHOULD ALLOW FOR SOME
LIGHT SN EVEN OVER THE SCENTRAL. BUT ABSENCE OF HIER ABSOLUTE MSTR..
.WITH PWAT NO MORE THAN ABOUT 0.3 INCH AND H7 SPECIFIC HUMIDITY
ABOUT 1G/KG...WL LIMIT SN TOTALS TO NO MORE THAN AN INCH OR SO AWAY
FM LK ENHANCEMENT/UPSLOPE WINDS. LATER AT NGT...EXPECT THE SN TO
DIMINISH NW-SE WITH THE ARRIVAL OF DNVA/DEEP LYR QVECTOR DVGC/
SUBSIDENCE/MID LVL DRYING IN THE WAKE OF THE PASSING SHRTWV THAT IS
FCST TO STRENGTHEN INVRN AS LO AS H875-9 AS SHOWN ON NAM FCST SDNGS.
ALTHOUGH IT IS NOT COMMON PRACTICE TO ISSUE AN ADVY FOR PRIMARLIY A
3RD PERIOD EVENT...SENSITIVE TRAVEL TIME JUST BEFORE THANKSGIVING
HOLIDAY AS WELL AS FAVORABLE UPSLOPE FLOW/FAIRLY EFFICIENT SN GROWTH
PARAMETERS WARRANTS EARLY ISSUANCE OF AN LES ADVY IN THE FAVORED
AREAS OVER THE W/NCENTRAL DESPITE THE RATHER FLUFFY NATURE OF THE SN
THAT IS EXPECTED TO FALL. THE LES ADVY WL INCLUDE GOGEBIC/
ONTONAGON/MARQUETTE AND ALGER COUNTIES. AS MUCH AS 7 TO 8 INCHES OF
SN WL FALL IN THESE AREAS THRU THE ADVY PERIOD. N WINDS GUSTING UP
TO 25-30 MPH WL CAUSE SOME BLSN NEAR LK SUP WED NIGHT INTO THU MRNG.
THANKSGIVING/THU NGT...THE LLVL FLOW IS PROGGED TO BACK STEADILY AND
TURN MORE ACYC ON THANKSGIVING WITH SFC HI PRES MOVING TOWARD SW WI
LATE IN THE DAY UNDER HGT RISES/DNVA IN ADVANCE OF APRCHG SHRTWV
RDG. THE RESULT WL BE SHIFTING/DIMINISHING LES BANDS...ESPECIALLY
OVER THE W HALF. THE SN SHOWERS SHOULD END COMPLETELY AT IWD LATE IN
THE AFTN. THE LES WL BE MORE PERSISTENT IN THE FAVORED SN BELTS E OF
MARQUETTE WITH H85 THERMAL TROF/TEMPS ARND -18C REACHING THAT AREA
LATE IN THE DAY...BUT INCRSG ACYC FLOW AND ABSENCE OF SGNFT LLVL
CNVGC/LOWERING INVRN BASE TO H875-9 SHOWN ON THE FCST SDNGS UNDER
THE NEGATIVE DYNAMICS WL LIMIT SN TOTALS. THANKSGIVING WL BE QUITE
CHILLY WITH H85 THERMAL TROF PASSING OVHD AND COULD FEATURE SOME
RECORD LO MAX TEMPS. EXPECT THE LOWEST TEMPS OVER THE W HALF WHERE
BACKING FLOW WL LIMIT LK SUP MODERATION. AS THE SFC RDG AXIS SHIFTS
TO THE E AND THE FLOW BACKS TO THE W-SW...LINGERING LES WL SHIFT OUT
INTO LK SUP ON THU NGT. TEMPS COULD FALL QUICKLY IN THE EVNG TOWARD
THE LO END OF GUIDANCE BEFORE MORE HI CLDS OVERSPREAD THE AREA W-E
ASSOCIATED WITH DVLPG ISENTROPIC ASCENT IN THE SW FLOW ON THE NW
FLANK OF PRES SHIFTING INTO THE OH RIVER VALLEY AND IN ADVANCE OF
SHRTWV STREAKING EWD TOWARD MN. SOME OF THE FASTER MODELS SHOW SN
ASSOCIATED WITH THIS WAA/SHRTWV REACHING THE FAR W BY 12Z FRI...SO
WL MAINTAIN SOME LO CHC POPS IN THIS AREA LATE THU NGT.
FRI/FRI NGT...AS THE UPR TROF IN ERN NAMERICA SHIFTS TO THE E...THE
FLOW OVER THE CONUS/SRN CANADA WL BECOME MORE ZONAL. DVLPG LLVL SW
FLOW/ISENTROPIC ASCENT OVER THE GREAT LKS ON THE NW FLANK OF SFC HI
PRES SHIFTING INTO THE SRN MID ATLANTIC STATES AND IN ADVANCE OF
SHRTWV TRACKING EWD THRU MN IS PROGGED BY MOST OF THE MEDIUM RANGE
GUIDANCE TO BRING ABOUT SOME INCRSG MID LVL MSTR/PCPN ON FRI TO THE
NE OF AN H85 WARM FNT STRETCHING FM THE NRN PLAINS INTO MN AND WI.
ALTHOUGH INITIAL SHOT OF SHARPER ISENTROPIC ASCENT BEST SHOWN ON THE
280-290K SFCS/H85-7 FGEN AXIS/DEEP LYR QVECTOR CNVGC IS FCST TO
IMPACT NRN WI ON FRI MRNG...THIS WAA/FORCING MAY SHIFT FARTHER N
INTO UPR MI DURING THE DAY. H7 SPECIFIC HUMIDITY IS FCST AS HI AS 3
G/KG...SO NOT OUT OF THE QUESTION THERE COULD BE SOME MODERATE SN
AMOUNTS APRCHG ADVY CRITERIA OVER THE SRN CWA. AS THE H925 WINDS
BECOME MORE S IN THE PRESENCE OF H85 TEMPS IN THE -8 TO -10C
RANGE...LES OFF LK MI WL IMPACT THE ERN CWA. WL MAINTAIN THE HIER
POPS/QPF IN THIS AREA. ON FRI NGT...MORE NOTABLE MODEL DIFFERENCES
ARE SHOWING UP WITH THE 12Z GFS SHOWING A MORE WNW VS W FLOW ALOFT
AND A STRONGER SHRTWV/SFC LO TRACKING FASTER E ACROSS LK SUP ON FRI
NGT...WITH CYC NW FLOW OF COLDER AIR DVLPG OVER THE CWA LATE FRI
NGT. THIS SOLUTION IS VERY MUCH AN OUTLIER EVEN AMONG THE MOST
RECENT GFS ENSEMBLE GUIDANCE... SO TENDED TO FOLLOW THE MORE
CONSISTENT 12Z CNDN/00Z AND 12Z ECMWF MODELS. THIS GUIDANCE SHOWS A
SLOWER SFC LO AND MORE AGGRESSIVE PUSH TO THE NE OF H85 WARM
FNT...WITH H85 TEMPS RISING ABOVE 0C OVER THE SCENTRAL CWA BY 12Z
SAT ACCOMPANYING DRY SLOTTING/LOWERING POPS OVER THE SRN TIER. WITH
ECWMF SDNGS SHOWING LINGERING LLVL MSTR BLO THE WARMING/DRYING WARM
NOSE ARND H85...ADDED A MENTION OF SOME FREEZING DZ OVER THE SW CWA.
SAT/SAT NGT...SHRTWV EMBEDDED IN ZONAL FLOW OVER SRN CANADA WL
STREAM E...WITH ACCOMPANYING SFC LO STREAKING ENEWD THRU ONTARIO AND
THEN DRAGGING A COLD FNT ACRS THE CWA SAT NGT. AHEAD OF THIS FNT...
MORE CONSISTENT...FAVORED 12Z ECMWF/CNDN MODELS SHOW WARM SURGE INTO
THE UPR LKS WITH H85 TEMPS RISING AS HI AS 8-10C OVER THE SRN TIER
ON SAT UNDER SOME MID LVL DRYING. TENDED TO CUT POPS OVER THE SRN
TIER...WHERE THE ECMWF AND CNDN MODELS SHOW MORE AGGRESSIVE MID LVL
DRYING FARTHER FM THE LO TRACK. CONTINUED TO MENTION SOME RA OR
FREEZING DZ IN THESE AREAS AS WELL. FARTHER TO THE N CLOSER TO THE
LO TRACK AND SOMEWHAT HIER CHC POPS...INCLUDED MENTION OF FREEZING
RA AND RA IN ADDITION TO SN IN CASE THE AIRMASS IS A BIT COLDER. IF
SFC TEMPS END UP HIER THAN CURRENTLY FCST...LATER SHIFTS MAY BE ABLE
TO CUT BACK ON THE FREEZING DZ/RA AND GO WITH PLAIN RA. RIGHT NOW...
LOOKS LIKE ANY ICE ACCUMULATION WL BE MINOR.
EXTENDED...MUCH COLDER AIR...WITH H85 TEMPS FCST AS LO AS -18C BY
00Z MON...AND SOME LK EFFECT SN WL FOLLOW ON SUN UNDER NW FLOW BTWN
DEPARTING COLD FNT AND CNDN HI PRES BLDG E THRU THE NRN PLAINS. BUT
SINCE THE UPR FLOW WL REMAIN FAIRLY PROGRESSIVE...THE SFC HI PRES WL
SHIFT THRU THE GREAT LKS ON MON AND INTO NEW ENGLAND TUE AS UPR RDG
BLDS INTO THE UPR LKS ON TUE. THE RESULT SHOULD BE DIMINISHING LES
ON MON WITH DRY WX LINGERING INTO TUE. WARMER SW FLOW ON THE WRN
FLANK OF DEPARTING SFC HI PRES MAY DRAW ENUF MSTR TO THE N ON TUE TO
BRING A RETURN OF SOME SN OR A RA/SN MIX.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 608 PM EST TUE NOV 25 2014
VFR CONDITIONS WILL CONTINUE AT KIWD/KSAW TONIGHT AND WILL CONTINUE
AT KSAW THROUGH WED. NEXT APPROACHING DISTURBANCE MAY BRING SOME
-SN/MVFR CONDITIONS TO KIWD LATE WED MORNING. AT KCMX...WINDS WILL
PROBABLY RETAIN ENOUGH OVERWATER COMPONENT TO MAINTAIN MVFR
CONDITIONS THRU THE PERIOD. BEFORE THE -SHSN END...THERE MAY
BE A PERIOD OF SOMEWHAT HEAVIER SNOW SHOWERS AT KCMX THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 PM EST TUE NOV 25 2014
PRES GRADIENT RAPIDLY WEAKENS TONIGHT WITH A WEAK SFC TROF DROPPING
SE OVER LAKE SUPERIOR. THIS WILL RESULT IN WINDS DIMINISHING TO UNDER
20KT ACROSS THE LAKE. STRONG HIGH PRES WILL THEN BUILD SE INTO THE
CANADIAN PRAIRIES WED AND INTO THE NRN PLAINS WED NIGHT. THIS WILL
PUSH THE TROF SE AND TIGHTEN THE PRES GRADIENT. AS A RESULT... WITH
THE TROF PASSAGE...EXPECT NORTHERLY WINDS TO RAMP UP TO 20-30KT FROM
NW TO SE WED/WED NIGHT. NOT OUT OF THE QUESTION THAT THERE COULD BE
SOME GALE FORCE GUSTS OVER THE CNTRL PORTION OF LAKE SUPERIOR. WINDS
WILL THEN DIMINISH TO UNDER 20KT W TO E THU/THU NIGHT AS HIGH PRES
RIDGE ARRIVES. WITH ANOTHER COLD FRONT PUSHING ACROSS THE UPPER LAKES
SAT...EXPECT INCREASING WINDS TO 15-25KT FRI/FRI NIGHT AHEAD OF
FRONT. BEHIND FRONT...NW WINDS MAY REACH 20-30KT LATE SAT/SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM WEDNESDAY TO 1 PM EST
THURSDAY FOR MIZ006.
LAKE EFFECT SNOW ADVISORY FROM 7 PM WEDNESDAY TO 10 AM EST
THURSDAY FOR MIZ005.
LAKE EFFECT SNOW ADVISORY FROM 3 PM EST /2 PM CST/ WEDNESDAY TO
10 AM EST /9 AM CST/ THURSDAY FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KC
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
410 PM EST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 358 PM EST MON NOV 24 2014
COLD AIR IS RAPIDLY MOVING ACROSS UPPER MICHIGAN. MOST PLACES EXCEPT
THE FAR SOUTH AND EAST HAVE TURNED OVER TO SNOW AS 850MB TEMPS
RAPIDLY DROP TO -12C OR LOWER BEHIND THE SFC LOW. OTHER THAN NEAR
LAKE SUPERIOR...THE REST OF THE AREA IS UNDER A LULL OF
PRECIPITATION BEHIND THE FIRST UPPER DISTURBANCE RAPIDLY MOVING NE
INTO CANADA. HOWEVER...THE SECOND WAVE OF ENERGY CURRENTLY STILL
OVER THE IOWA AND SRN WI WILL MOVE TOWARD THE AREA THIS EVENING.
MODERATE MID LEVEL Q-VECTOR CONVERGENCE ALONG WITH MODERATE
850-700MB FRONTOGENETIC FORCING OWED TO THE MID LEVEL DEFORMATION
AXIS WILL MOVE ACROSS WI AND ACROSS THE FAR SOUTHERN PART OF THE
FORECAST AREA TONIGHT. THIS WILL ALLOW FOR A PERIOD OF SYSTEM SNOW
TO SPREAD ACROSS AREAS GENERALLY ALONG AND SOUTH OF U.S. 2 IN
MENOMINEE AND DELTA COUNTIES TONIGHT. RAPID UPDATE NWP SUGGEST UP TO
0.50 INCH OF LIQUID TONIGHT /WITH THE LATEST HRRR SUGGESTING UP TO
0.75 INCH/. BUT GIVEN THAT THE SYSTEM WILL BE MOVING FAIRLY FAST TO
THE NE AND 700MB SPECIFIC HUMIDITY VALUES ARE AT MOST 3 G/KM THIS
EVENING...AM EXPECTING QPF OF SLIGHTLY LESS THAN 0.50 INCH. WITH
SNOW RATIOS RISING TO 10-15:1 THIS EVENING...THIS WOULD SUGGEST THAT
FAR SOUTHERN MENOMINEE COUNTY COULD SEE 4-6 INCHES OF SNOW STARTING
LATE THIS AFTERNOON AND CONTINUING INTO OVERNIGHT. AS SUCH...HAVE
OPTED TO ISSUE A WINTER WEATHER ADVY FOR MENOMINEE COUNTY...FOCUSING
ON AREAS MAINLY SOUTH OF US 2. AM CURRENTLY THINKING THAT SYSTEM
PCPN WILL DIMINISH OVER A RELATIVELY SHORT DISTANCE TO THE
NORTH...SO AS OF NOW WILL LEAVE DICKINSON AND DELTA COUNTIES OUT OF
THE WINTER WEATHER ADVY.
AS FOR THE REMAINDER OF THE AREA...NO MAJOR CHANGES TO THE FORECAST
PLANNED. AS THE COLDER AIR MOVES ACROSS THE AREA THIS
EVENING...EXPECT BETTER LES BANDS TO DEVELOP IN THE N-NW
FLOW...SIMILAR TO WHAT IS OCCURRING AT IWD RIGHT NOW. CURRENT SNOW
RATIOS ARE FAIRLY LOW...GENERALLY 10-15:1 DUE TO THE SNOW GROWTH
REGION STILL FAIRLY HIGH. AS THE COLDER AIR MOVES IN...THE
EXPECTATION IS THAT THE SNOW RATIOS WILL BECOME HIGHER...CLOSER TO
20:1. AS SUCH...WILL MAINTAIN ALL LAKE EFFECT SNOW ADVISORIES AS
IS...WITH SIMILAR FORECAST AMOUNTS EXPECTED. STILL EXPECTING STORM
TOTAL OF 5-8 INCHES ACROSS THE GOGEBIC RANGE...4-7 INCHES
KEWEENAW...4-9 INCHES N-CENTRAL UPPER MI...AND 4-7 INCHES EAST OF
MARQUETTE. BLOWING SNOW NEAR LAKE SUPERIOR WILL STILL BE A PROBLEM
WITH SOME GUSTS IN EXCESS OF 30 MPH.
THE LES SHOULD GRADUALLY DIMINISH FROM WEST TO EAST LATE TONIGHT
INTO TUESDAY BEHIND THE UPPER TROUGH WHICH MOVES THROUGH LATE
TONIGHT. BEHIND THIS TROUGH...WEAK SFC RIDGING BUILDS IN ALONG WITH
BACKING PBL WINDS AND A DRIER AIRMASS ALLOWING FOR ANY REMAINING LES
TO SHIFT TO THE KEWEENAW AND ACROSS THE OPEN LAKE TUE AFTN. AS
SUCH...WILL MAINTAIN CHANCE POPS FOR THE ENTIRE DAY ACROSS THE
KEWEENAW BUT END THE POPS ACROSS THE FAR WEST. WILL MAINTAIN HIGHER
POPS EAST DUE TO W-NW FLOW HANGING ON FOR MUCH OF THE DAY THERE
ALONG WITH DEEPER MOISTURE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 408 PM EST MON NOV 24 2014
MAIN FCST CONCERNS IN THE LONGER TERM WL BE FOCUSED ON THE POTENTIAL
FOR AT LEAST SOME MARGINAL ADVY LES TOTALS ON WED INTO EARLY
THANKSGIVING ASSOCIATED WITH A SHRTWV DIGGING SEWD THRU THE UPR LKS.
FORTUNATELY FOR THOSE INTERESTED IN TRAVEL ON THANKSGIVING...MODELS
HAVE CONTINUED TREND TOWARD LESS PHASING BTWN A PAIR OF SHRTWVS THAT
WL LIMIT THE POTENTIAL FOR HEAVIER SN AWAY FM LK SUP. TEMPS WL RUN
BLO TO WELL BLO NORMAL ON TUE NGT INTO FRI WITH AN UPR TROF
DEEPENING OVER ERN NAMERICA. AS THIS TROF GIVES WAY TO A MORE ZONAL
FLOW THIS WEEKEND...A MORE CHANGEABLE PATTERN WL DOMINATE WITH
WARMER AIR IN STORE FOR SAT.
TUE NGT...A WEAK SFC HI PRES UNDER SUBTLE SHRTWV RDGING/AREA OF DEEP
LYR QVECTOR DVGC WL DOMINATE MOST OF THE NGT AND BRING DRY WX TO
MOST OF THE CWA. THE BEST CHC FOR SOME PCPN WL BE OVER THE NW CWA
NEAR A STATIONARY FNT ORIENTED W-E OVER LK SUP. H85 TEMPS ANRD -13C
MAY SUPPORT A LK EFFECT COMPONENT...ESPECIALLY LATE WHEN SOME DPVA/
DEEP LYR QVECTOR CNVGC IN ADVANCE OF A SHRTWV DIGGING SEWD TOWARD
THE CNDN/MN BORDER IS FCST TO ARRIVE. EXPECT THE LOWEST MIN TEMPS
OVER THE INTERIOR SCENTRAL AND E WHERE THE NEGATIVE DYNAMICS SHOULD
LINGER THRU THE NGT IN THE PRESENCE OF PWAT UNDER 0.25 INCH AND
MINIMIZE CLD COVER EXCEPT FOR SOME HIER CLDS SPILLING INTO UPR MI
AHEAD OF THE INCOMING SHRWTV.
WED...SHRTWV APRCHG FM THE NW IS FCST TO MOVE INTO WRN LK SUP BY 00Z
THU...WITH DPVA/DEEP LYR QVECTOR CNVGC INVADING UPR MI. BUT SINCE
THE MODELS HAVE TRENDED TOWARD LESS PHASING BTWN THIS SHRTWV AND
ANOTHER STRONGER DISTURBANCE DIGGING SEWD IN THE MID MS RIVER VALLEY
THAT WL ROB THE AREA OF DEEPER MSTR AND LEAVE PWAT NO HIER THAN
ABOUT 0.25-0.30 INCH...ACCOMPANYING SN OVER THE CWA SHOULD BE
RELATIVELY LGT. THE BEST CHC FOR MORE SN WL BE IN THE N WIND SN
BELTS NEAR LK SUP AS THE H925 FLOW SHIFTS TO THE N COINCIDENT WITH
PASSING NRN SHRTWV AND ALLOWS FOR SOME LES AS H85 TEMPS FALL TO ARND
-15C OVER THE NW BY 00Z WED. SN TOTALS IN THAT AREA MAY ALSO BE
BOOSTED A BIT BY RATHER DEEP DGZ BTWN ABOUT 4-9K FT MSL EVEN THOUGH
MORE SHARPER UVV IS NOT FCST WITHIN THAT LYR. NOT OUT OF THE
QUESTION THE FLOW MAY BACK SUFFICIENTLY TO THE SW IN ADVANCE OF THE
SHRTWV TO ALLOW FOR A PERIOD OF SOME LK EFFECT SN OFF LK MI INTO THE
SE CWA IN THE PRESENCE OF H85 TEMPS NEAR -10C.
WED NGT...STEADY NNW WIND IN THE WAKE OF PASSING SHRTWV IS FCST TO
ADVECT H85 TEMPS AS LO AS -20C OVER THE KEWEENAW BY 12Z THU. THERE
MAY BE SOME ADVY LVL LES IN THE FAVORED SN BELTS AS THERE WL BE A
PERIOD WHERE THE FAVORABLE CAA/CYC NNW FLOW IS COINCIDENT WITH
DEEPER MSTR/SOME DEEP LYR QVECTOR CNVGC THAT WL LIKELY BRING SOME
LIGHTER SN EVEN TO THE SCENTRAL. THE ARRIVAL OF SOME DNVA/DEEP LYR
QVECTOR DVGC LATER AT NGT IS PROGGED TO SHARPLY LOWER INVRN BASE
TOWARD H85...WHICH SHOULD BRING ABOUT A DIMINISHING TREND IN THE LES
OVER AT LEAST THE W HALF. THE 12Z GFS IS FASTEST WITH THIS
DIMINISHING TREND.
THANKSGIVING/THU NGT...THE LLVL FLOW IS PROGGED TO BACK STEADILY AND
TURN MORE ACYC ON THANKSGIVING WITH SFC HI PRES MOVING TOWARD WI
LATE IN THE DAY UNDER HGT RISES/DNVA IN ADVANCE OF APRCHG SHRTWV
RDG. THE RESULT WL BE SHIFTING/DIMINISHING LES BANDS...ESPECIALLY
OVER THE W HALF. THE LES WL BE MORE PERSISTENT IN THE FAVORED SN
BELTS E OF MARQUETTE...BUT LO INVRN BASE BLO H85 SHOWN ON THE FCST
SDNGS UNDER THE NEGATIVE DYNAMICS WL LIMIT SN TOTALS. AS THE SFC
RDG AXIS SHIFTS TO THE E AND THE FLOW BACKS TO THE W-SW...LINGERING
LES WL SHIFT OUT INTO LK SUP ON THU NGT. TEMPS COULD FALL QUICKLY IN
THE EVNG BEFORE MORE HI CLDS ASSOCIATED WITH DVLPG ISENTROPIC ASCENT
OVERSPREAD THE AREA W-E.
FRI INTO SAT...AS THE UPR TROF IN ERN NAMERICA SHIFTS TO THE E...THE
FLOW OVER THE CONUS/SRN CANADA WL BECOME MORE ZONAL. DVLPG LLVL SW
FLOW/ISENTROPIC ASCENT OVER THE GREAT LKS ON THE NW FLANK OF SFC HI
PRES SHIFTING INTO THE SRN MID ATLANTIC STATES THAT WL BE FORCING
THIS CHANGE IN THE UPR PATTERN IS PROGGED BY MOST OF THE MEDIUM
RANGE GUIDANCE IS FCST TO BRING ABOUT SOME INCRSG MID LVL MSTR/PCPN
ON FRI TO THE NE OF AN H85 WARM FNT STRETCHING FM THE NRN PLAINS
INTO MN. THE LATEST MODEL GUIDANCE HINTS THE HEAVIER PCPN ASSOCIATED
WITH THIS WARM AIR RETURN ON FRI MAY FALL TO THE SW IN WI. EXPECT
THE HIER POPS OVER THE ERN CWA WITH SW FLOW OF COLD AIR OFF LK MI
ALLOWING FOR SOME LES INTO THAT AREA ON FRI. AS A SHRTWV WITHIN THE
ZONAL FLOW SHIFTS EWD NEAR THE CNDN BORDER...A SFC LO PRES WL SHIFT
EWD AND JUST N OF LK SUP ON SAT. MOST OF THE GUIDANCE SHOWS H85
TEMPS RISING TO AOA 0C OVER AT LEAST THE S HALF OF THE CWA ON SAT...
INDICATING THE POTENTIAL FOR SOME MIXED PCPN. GFS FCST SDNGS SHOW AN
ELEVATED WARM LYR...SO INCLUDED A MENTION OF SOME FREEZING RA OVER
THE SCENTRAL WHERE THE WARM WEDGE H85 TEMPS ARE OVER 0C. THE MODELS
SUCH AS THE 12Z GFS AND ESPECIALLY THE 12Z CND THAT SHOW THE DEEPEST
SFC LO/FARTHER N TRACK ACTUALLY INDICATE UPR MI MIGHT SEE SOME DRY
SLOTTING AS THE H85 WARM FNT SHIFTS TO THE N OF THE CWA AND H85
TEMPS RISE AS HI AS 5-6C...SO POPS WL BE LOWEST OVER THE S.
SUN/MON...AS THE SHRTWV/SFC LO SHIFT INTO QUEBEC SAT NGT/SUN...
ATTENDANT COLD FNT WL SWING THRU UPR MI AND BRING A RETURN OF COLDER
AIR AND SOME LES FOR SUN. TRAILING HI PRES WL PASS TRHU THE CENTRAL
GREAT LKS ON SUN NGT...ENDING THIS LES. AS THE HI SHIFTS TOWARD NEW
ENGLAND...EXPECT A RETURN SW FLOW OF WARMER AIR TO DVLP ON MON.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 239 PM EST MON NOV 24 2014
IFR TO LIFR CONDITIONS WILL PERSIST THIS AFTERNOON AS LAKE EFFECT
SNOW REDUCES VSBYS TO LESS THAN A MILE AT CMX/IWD. SAW STILL
MVFR...BUT EXPECT IFR CONDITIONS TO COMMENCE THERE AS WELL WHEN THE
BETTER LAKE EFFECT SNOW BANDS DEVELOP. IFR CONDITIONS WILL COTNINUE
THROUGH THE OVERNIGHT BEFORE IMPROVING TO MVFR ON TUESDAY AS DRIER
AIR MOVES IN. ALL SITES WILL ALSO SEE NORTH-NORTHEAST WINDS GUST TO
30+ KT THROUGH THIS EVENING CAUSING SOME BLSN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 PM EST MON NOV 24 2014
STRONG LOW PRESSURE NEAR SAULT STE MARIE JUST SOUTH OF JAMES BAY
WILL RAPIDLY MOVE INTO NRN QUEBEC TONIGHT. N-NW GALES WILL PERSIST
ACROSS THE LAKE TONIGHT...THEN SUBSIDE RATHER QUICKLY TUESDAY
MORNING. GENERALLY QUIET WEATHER EXPECTED FOR THE REMAINDER OF THE
WEEK...ALTHOUGH A LOW PRESSURE SYSTEM MOVING SOUTH OF THE LAKE WED
INTO WED NIGHT MAY ALLOW FOR N-NE WINDS TO GUST TO NEAR GALE FORCE.
HIGH PRESSURE BY THE WEEKEND SHOULD ALLOW FOR WINDS LESS THAN 20 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST TUESDAY FOR MIZ006-007-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ TUESDAY FOR
MIZ001>003-009.
LAKESHORE FLOOD ADVISORY UNTIL 6 AM EST TUESDAY FOR MIZ001-003-
005>007.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST TUESDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 5 AM CST TUESDAY FOR MIZ012.
LAKE SUPERIOR...
GALE WARNING UNTIL 4 AM EST TUESDAY FOR LSZ246>251-265>267.
GALE WARNING UNTIL 2 AM EST TUESDAY FOR LSZ242>245-263-264.
GALE WARNING UNTIL 9 PM EST /8 PM CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...KC
AVIATION...MRD
MARINE...MRD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
359 PM EST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 358 PM EST MON NOV 24 2014
COLD AIR IS RAPIDLY MOVING ACROSS UPPER MICHIGAN. MOST PLACES EXCEPT
THE FAR SOUTH AND EAST HAVE TURNED OVER TO SNOW AS 850MB TEMPS
RAPIDLY DROP TO -12C OR LOWER BEHIND THE SFC LOW. OTHER THAN NEAR
LAKE SUPERIOR...THE REST OF THE AREA IS UNDER A LULL OF
PRECIPITATION BEHIND THE FIRST UPPER DISTURBANCE RAPIDLY MOVING NE
INTO CANADA. HOWEVER...THE SECOND WAVE OF ENERGY CURRENTLY STILL
OVER THE IOWA AND SRN WI WILL MOVE TOWARD THE AREA THIS EVENING.
MODERATE MID LEVEL Q-VECTOR CONVERGENCE ALONG WITH MODERATE
850-700MB FRONTOGENETIC FORCING OWED TO THE MID LEVEL DEFORMATION
AXIS WILL MOVE ACROSS WI AND ACROSS THE FAR SOUTHERN PART OF THE
FORECAST AREA TONIGHT. THIS WILL ALLOW FOR A PERIOD OF SYSTEM SNOW
TO SPREAD ACROSS AREAS GENERALLY ALONG AND SOUTH OF U.S. 2 IN
MENOMINEE AND DELTA COUNTIES TONIGHT. RAPID UPDATE NWP SUGGEST UP TO
0.50 INCH OF LIQUID TONIGHT /WITH THE LATEST HRRR SUGGESTING UP TO
0.75 INCH/. BUT GIVEN THAT THE SYSTEM WILL BE MOVING FAIRLY FAST TO
THE NE AND 700MB SPECIFIC HUMIDITY VALUES ARE AT MOST 3 G/KM THIS
EVENING...AM EXPECTING QPF OF SLIGHTLY LESS THAN 0.50 INCH. WITH
SNOW RATIOS RISING TO 10-15:1 THIS EVENING...THIS WOULD SUGGEST THAT
FAR SOUTHERN MENOMINEE COUNTY COULD SEE 4-6 INCHES OF SNOW STARTING
LATE THIS AFTERNOON AND CONTINUING INTO OVERNIGHT. AS SUCH...HAVE
OPTED TO ISSUE A WINTER WEATHER ADVY FOR MENOMINEE COUNTY...FOCUSING
ON AREAS MAINLY SOUTH OF US 2. AM CURRENTLY THINKING THAT SYSTEM
PCPN WILL DIMINISH OVER A RELATIVELY SHORT DISTANCE TO THE
NORTH...SO AS OF NOW WILL LEAVE DICKINSON AND DELTA COUNTIES OUT OF
THE WINTER WEATHER ADVY.
AS FOR THE REMAINDER OF THE AREA...NO MAJOR CHANGES TO THE FORECAST
PLANNED. AS THE COLDER AIR MOVES ACROSS THE AREA THIS
EVENING...EXPECT BETTER LES BANDS TO DEVELOP IN THE N-NW
FLOW...SIMILAR TO WHAT IS OCCURRING AT IWD RIGHT NOW. CURRENT SNOW
RATIOS ARE FAIRLY LOW...GENERALLY 10-15:1 DUE TO THE SNOW GROWTH
REGION STILL FAIRLY HIGH. AS THE COLDER AIR MOVES IN...THE
EXPECTATION IS THAT THE SNOW RATIOS WILL BECOME HIGHER...CLOSER TO
20:1. AS SUCH...WILL MAINTAIN ALL LAKE EFFECT SNOW ADVISORIES AS
IS...WITH SIMILAR FORECAST AMOUNTS EXPECTED. STILL EXPECTING STORM
TOTAL OF 5-8 INCHES ACROSS THE GOGEBIC RANGE...4-7 INCHES
KEWEENAW...4-9 INCHES N-CENTRAL UPPER MI...AND 4-7 INCHES EAST OF
MARQUETTE. BLOWING SNOW NEAR LAKE SUPERIOR WILL STILL BE A PROBLEM
WITH SOME GUSTS IN EXCESS OF 30 MPH.
THE LES SHOULD GRADUALLY DIMINISH FROM WEST TO EAST LATE TONIGHT
INTO TUESDAY BEHIND THE UPPER TROUGH WHICH MOVES THROUGH LATE
TONIGHT. BEHIND THIS TROUGH...WEAK SFC RIDGING BUILDS IN ALONG WITH
BACKING PBL WINDS AND A DRIER AIRMASS ALLOWING FOR ANY REMAINING LES
TO SHIFT TO THE KEWEENAW AND ACROSS THE OPEN LAKE TUE AFTN. AS
SUCH...WILL MAINTAIN CHANCE POPS FOR THE ENTIRE DAY ACROSS THE
KEWEENAW BUT END THE POPS ACROSS THE FAR WEST. WILL MAINTAIN HIGHER
POPS EAST DUE TO W-NW FLOW HANGING ON FOR MUCH OF THE DAY THERE
ALONG WITH DEEPER MOISTURE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON NOV 24 2014
LIGHT TO MODERATE LAKE EFFECT WILL BE ONGOING TO START TUESDAY MORNING
WITH DELTA T/S OVER 15C AND NNW LOW-LEVEL WINDS IN WAKE OF THE
DEPARTING SFC LOW PRESSURE TROUGH. INVERSIONS UP TO 5KFT DOES PUT MOST
OF THE CLOUD BEARING LAYER IN THE DGZ...BUT WITH INCREASING DRYING
AND SUBSIDENCE ALOFT AS MAIN SHORTWAVE MOVES EAST...EXPECT THE LAKE EFFECT
TO DIMINISH THROUGH THE DAY AS LOW-LEVEL WINDS BECOME ANTICYCLONIC
AS RIDGE MOVES IN. ENDING TIMES FOR CURRENT LAKE EFFECT ADVISORIES
SEEM GOOD BASED ON THE DIMINISHING TRENDS IN SNOW SHOWERS AND WINDS/BLSN.
TUESDAY NIGHT INTO WEDNESDAY ONE SHORTWAVE AND A LOW PRESSURE SYSTEM
IS EXPECTED TO DIP ESE FM THE NORTHERN PLAINS TOWARD THE MIDDLE
MISSISSIPPI RIVER VALLEY. SWATH OF SNOW SHOULD ACCOMPANY THIS LOW
PRESSURE AREA AND THAT SHOULD STAY MAINLY SOUTH OF UPPER MICHIGAN.
INVERTED SFC TROUGH WILL BE PRESENT TO THE NORTH OF THE MAIN SFC LOW
AND THAT WOULD EXTEND INTO UPR MICHIGAN. SHORTWAVE LIKELY TO BE THE
MAIN FOCUS FOR THE WEATHER OVR CWA ON WEDNESDAY INTO THANKSGIVING IS
IN THE NORTHERN STREAM AND SLIDES OVER THE AREA FM SOUTHERN MANITOBA
AND NORTHWEST ONTARIO IN THE AFTN. OVERALL...PREFER THE OVERALL IDEA
OFFERED BY THE NAM/GFS/ECMWF COMPARED TO THE GEM-NH AS THAT MODEL
SEEMS TOO PHASED WITH THE NORTHERN STREAM AND SOUTHERN STREAM
SHORTWAVES WITH THE RESULT THAT THE THE MAIN SFC LOW IS TOO FAR
NORTH. ECMWF CONTINUES TO SHOW SHARPER TROUGH/CONVERGENCE AND LAKE
ENHANCED SNOW FOR NORTHWEST CWA NOT UNTIL WED NIGHT THEN OVER NCNTRL
CWA ON THANKSGIVING DAY. GFS CONTINUES TO INDICATE WEAKER OVERALL
SYSTEM BUT DOES BRING THE NORTH WIND LAKE EFFECT SNOW SHOWERS IN
EARLIER...MORE SO ON WEDNESDAY AFTN INTO WEDNESDAY NIGHT. GIVEN COLD
POOL OF AIR TO NORTH OF THE SFC TROUGH WITH H85 TEMPS DOWN TO AS LOW
AS -20C THERE WILL BE CERTAINLY BE SOME LAKE EFFECT SNOW SHOWERS
WEDNESDAY INTO THANKSGIVING. IN ADDITION...WILL NEED TO WATCH LAKE
EFFECT OFF LK MICHIGAN IN THE S/SE WINDS AHEAD OF THE SFC TROUGH.
WINDS BACK STEADILY FROM LATE TUESDAY NIGHT INTO WEDNESDAY OVER
NORTHERN LK MICHIGAN. FORECAST SOUNDINGS POINT TO SCT LAKE EFFECT TO
EXPAND OVER MUCH OF THE EASTERN CWA BY LATE WEDNESDAY AS THE ONSHORE
FLOW IS ENHANCED BY THE LARGER SCALE LIFT AND MOISTURE FM THE NEARING
NORTHERN STREAM SHORTWAVE.
SHARPNESS OF SFC TROUGH AND EXTENT OF CONVERGENCE STILL UNCERTAIN
THOUGH WHICH AFFECTS INTENSITY/EXTENT OF THE LES BOTH OFF LK
SUPERIOR AND LK MICHIGAN AND ALSO THE STRENGTH OF WINDS/BLSN NEAR LK
SUPERIOR IN WAKE OF TROUGH. LATEST RUNS OF GFS AND ECMWF KEEP WITH
CONTINUITY COMPARED TO THEIR PREVIOUS RUNS...GIVING NO TREND TO
LATCH ON. THOSE THAT HAVE TRAVEL PLANS WEDNESDAY INTO THANKSGIVING
NEAR LK SUPERIOR AND ALSO OVER MOST OF THE EAST HALF OF UPR MICHIGAN
SHOULD BE AWARE THAT DURING THIS TIME FRAME THERE COULD AT LEAST
LOCALIZED HIGHER IMPACT WEATHER.
HIGH PRESSURE DIVING OVER THE PLAINS WITH RIDGING OVER NORTHERN
ONTARIO EVENTUALLY SHOULD WIN OUT LATER ON THANKSGIVING. THOUGH IF
THE STRONGER TROUGH FM ECMWF IS CORRECT...DIMINISHING TREND IN THE
LAKE EFFECT WOULD BE MORE ON THURSDAY NIGHT. ONCE THE SFC RIDGE
SLIDES EAST ON FRIDAY...UPPER FLOW FLATTENS OUT ALLOWING FOR WARM
AIR ADVECTION TO RAMP UP OVER THE PLAINS. INDICATIONS THAT AT LEAST
ONE SHORTWAVE WILL ALSO BE PROPELLING FROM THE NORTHERN PLAINS
TOWARD THE WESTERN GREAT LAKES. DECENT JET STREAK ALSO FCST OVER THE
PLAINS WHICH SHOULD ENHANCED LIFT ALONG THE TIGHT LOW-LEVEL
BAROCLINIC ZONE. SWATH OF AT LEAST LIGHT SNOW SHOULD RESULT
SOMEWHERE VCNTY OF NORTHERN PLAINS TO THE WESTERN GREAT LAKES.
CONSIDERING THE WAVE THAT WILL GENERATE THE SNOW IS STILL TO EMERGE
FROM UPPER TROUGH OVER NORTHERN PACIFIC VCNTY OF 40N/155W...GFS IS
CONSISTENT IN SHOWING THIS AND GEM-NH IS THERE AS WELL. ECMWF JUST
TRENDED THIS WAY WITH THE 23NOV/12Z RUN. PLENTY OF TIME TO LOOK AT
THE DETAILS BUT DOES APPEAR THAT PTYPE WILL STAY ONLY SNOW AS WARM
AIR AT H85 IS FORECAST TO REMAIN SOUTHWEST OF UPPER LAKES.
MIXED SIGNALS THAT COULD SEE SOME LGT MIXED PRECIP FRIDAY NIGHT INTO
SATURDAY AS THE H9-H8 WARM LAYER ARRIVES. COULD SEE SOME DRIZZLE AND
FOG ISSUES TOO THOUGH AT LEAST RIGHT NOW...GFS/ECMWF ARE NOT SHOWING
DWPNTS AS HIGH AS ARE CURRENTLY OCCURRING OVER AREA. REAL MODEL
DIFFERENCES TO CLOSE THE LONG TERM...WITH 23NOV/12Z ECMWF KEEPING
THE WARM SECTOR OVER THE AREA INTO SUNDAY...WHILE THE GFS SHOVES
SHARPER COLD FRONT OVER THE UPPER GREAT LAKES BY SUNDAY. AT 12Z
SUNDAY...H85 TEMPS VARY FROM -5C OFF THAT RUN OF ECMWF TO -24C
OFF THE GFS. LATEST ECMWF TRENDED TOWARD GFS AS IT NOW SHOWS H85
TEMP THAT SAME TIME OF -16C. USED A CONSENSUS OF THE MODELS UNTIL
THE DIFFERENCES ARE RESOLVED...BUT GIVEN THE TREND FM THE LATEST
ECMWF...WENT WITH A BIT HIGHER POPS AND LOWERED TEMPS SLIGHTLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 239 PM EST MON NOV 24 2014
IFR TO LIFR CONDITIONS WILL PERSIST THIS AFTERNOON AS LAKE EFFECT
SNOW REDUCES VSBYS TO LESS THAN A MILE AT CMX/IWD. SAW STILL
MVFR...BUT EXPECT IFR CONDITIONS TO COMMENCE THERE AS WELL WHEN THE
BETTER LAKE EFFECT SNOW BANDS DEVELOP. IFR CONDITIONS WILL COTNINUE
THROUGH THE OVERNIGHT BEFORE IMPROVING TO MVFR ON TUESDAY AS DRIER
AIR MOVES IN. ALL SITES WILL ALSO SEE NORTH-NORTHEAST WINDS GUST TO
30+ KT THROUGH THIS EVENING CAUSING SOME BLSN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 358 PM EST MON NOV 24 2014
STRONG LOW PRESSURE NEAR SAULT STE MARIE JUST SOUTH OF JAMES BAY
WILL RAPIDLY MOVE INTO NRN QUEBEC TONIGHT. N-NW GALES WILL PERSIST
ACROSS THE LAKE TONIGHT...THEN SUBSIDE RATHER QUICKLY TUESDAY
MORNING. GENERALLY QUIET WEATHER EXPECTED FOR THE REMAINDER OF THE
WEEK...ALTHOUGH A LOW PRESSURE SYSTEM MOVING SOUTH OF THE LAKE WED
INTO WED NIGHT MAY ALLOW FOR N-NE WINDS TO GUST TO NEAR GALE FORCE.
HIGH PRESSURE BY THE WEEKEND SHOULD ALLOW FOR WINDS LESS THAN 20 KT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST TUESDAY FOR MIZ006-007-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ TUESDAY FOR
MIZ001>003-009.
LAKESHORE FLOOD ADVISORY UNTIL 6 AM EST TUESDAY FOR MIZ001-003-
005>007.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST TUESDAY FOR MIZ004-005.
WINTER WEATHER ADVISORY UNTIL 5 AM CST TUESDAY FOR MIZ012.
LAKE SUPERIOR...
GALE WARNING UNTIL 4 AM EST TUESDAY FOR LSZ246>251-265>267.
GALE WARNING UNTIL 2 AM EST TUESDAY FOR LSZ242>245-263-264.
GALE WARNING UNTIL 9 PM EST /8 PM CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...JLA
AVIATION...MRD
MARINE...MRD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
240 PM EST MON NOV 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 537 AM EST MON NOV 24 2014
WV IMAGERY AND RUC ANALYSIS SHOWS A MID-UPR LEVEL TROUGH OVER THE
NRN/CENTRAL PLAINS WITH A COUPLE OF STRONG SHORTWAVES OUT AHEAD OF
THIS TROUGH IN A SW FLOW. ONE SHORTWAVE WAS MOVING ACROSS LAKE HURON
NEARLY CO-LOCATED WITH THE 980 MB SFC LOW WHILE ANOTHER SHORTWAVE
WAS TRIGGERING THUNDERSTORMS AS IT LIFTED THROUGH SRN IL AND SRN IN.
DEFORMATION PCPN SHIELD IN COMMA HEAD OF LAKE HURON SHORTWAVE HAS
BEEN RESPONSIBLE FOR THE LIGHT PCPN OVER MUCH OF WEST AND CENTRAL
UPPER MI THIS MORNING WITH SOME MODERATE RAIN OVER ERN UPPER MI. THE
RAIN OVER THE EXISTING SNOW PACK CONTINUES TO SUPPORT AREAS OF FOG
BUT VSBYS OVER MOST AREAS HAVE RISEN ENOUGH TO CANCEL DENSE FOG
ADVISORY.
TODAY...MODELS AND REGIONAL RADAR IMAGERY SUGGEST THAT THERE MAY BE
A LULL IN THE PCPN BETWEEN THE EXITING NRN LAKE SHRTWV AND THE MID
LEVEL TROUGH MOVING IN FROM THE UPPER MS VALLEY/NRN PLAINS. AS THE
DEEPENING SFC LOW OVER LAKE HURON LIFTS QUICKLY NE THE COLDER AIR
WILL ALSO SLIDE QUICKLY THROUGH UPPER MI WITH THE RAIN CHANGING OVER
TO SNOW FROM 12Z-21Z FROM W TO EAST PER MODEL SNDGS AND 1000-850 MB
LOW-LVL LEVEL THICKNESS. WITH THE LOSS OF THE STRONGER LARGE SCALE
FORCING/DEEP LAYER Q-VECT CONVERGENCE TIL AFTERNOON EXPECT MAINLY
JUST LIGHT TO MODERATE LAKE ENHANCED SNOW OVER THE WEST HALF FOR NNW
FLOW FAVORED LOCATIONS AS 850 MB TEMPS FALL TO NEAR -8C WEST BY 18Z
AND TO AROUND -12C ACROSS WEST AND NCNTRL LOCATIONS BY 00Z. EXPECT
SNOWFALL AMOUNTS IN THE 2 TO 3 RANGE OVER THE WEST WITH GENERALLY
1-2 INCHES NCNTRL...EXCEPT UP TO 3 INCHES POSSIBLE OVER THE HURON
MOUNTAIN AREA. A TIGHT GRADIENT BEHIND THE LOW WILL BRING STRONG
NRLY WINDS WITH GUSTS TO 30-40 MPH PRODUCING SOME BLOWING AND
DRIFTING SNOW.
TONIGHT...MODELS CONTINUE TO SHOW DEEP MOISTURE/Q-VECTOR CONVERGENCE
AS MID-LVL TROUGH LINGERS OVER THE AREA. ALSO MODEL SOUNDINGS
SUGGEST THE POTENTIAL FOR GOOD SNOW GROWTH AT LEAST THIS EVENING AS
BEST MODEL OMEGA/LIFT INTERSECTS DGZ. CONVERGENT NNW FLOW WILL FAVOR
3-5 INCH ACCUMULATIONS OVER THE HIGHER TERRAIN OF THE WEST AND
NCNTRL COUNTIES WITH PERHAPS ISOLATED 6 INCH AMOUNTS POSSIBLE OVER
THE HURON MOUNTAINS. LAKE ENHANCED SNOW MAY TAPER OFF OVER THE WRN
COUNTIES LATE TONIGHT AS BEST FORCING/Q-VECT CONV BEGINS TO SHIFT
EAST.
CURRENT LAKE EFFECT SNOW ADVISORIES STILL ON TRACK FOR ALL OF WEST
AND NORTH CENTRAL UPPER MI WITH THE GREATEST SNOW TOTAL
ACCUMULATIONS OF 5 TO 9 INCHES EXPECTED OVER HIGHER TERRAIN
LOCATIONS NEAR LAKE SUPERIOR INTO TUESDAY. SOME ISOLATED 10" AMOUNTS
MAY BE POSSIBLE OVER THE HURON MOUNTAINS AIDED BY UPSLOPE FM THE
HIGHER TERRAIN THERE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON NOV 24 2014
LIGHT TO MODERATE LAKE EFFECT WILL BE ONGOING TO START TUESDAY MORNING
WITH DELTA T/S OVER 15C AND NNW LOW-LEVEL WINDS IN WAKE OF THE
DEPARTING SFC LOW PRESSURE TROUGH. INVERSIONS UP TO 5KFT DOES PUT MOST
OF THE CLOUD BEARING LAYER IN THE DGZ...BUT WITH INCREASING DRYING
AND SUBSIDENCE ALOFT AS MAIN SHORTWAVE MOVES EAST...EXPECT THE LAKE EFFECT
TO DIMINISH THROUGH THE DAY AS LOW-LEVEL WINDS BECOME ANTICYCLONIC
AS RIDGE MOVES IN. ENDING TIMES FOR CURRENT LAKE EFFECT ADVISORIES
SEEM GOOD BASED ON THE DIMINISHING TRENDS IN SNOW SHOWERS AND WINDS/BLSN.
TUESDAY NIGHT INTO WEDNESDAY ONE SHORTWAVE AND A LOW PRESSURE SYSTEM
IS EXPECTED TO DIP ESE FM THE NORTHERN PLAINS TOWARD THE MIDDLE
MISSISSIPPI RIVER VALLEY. SWATH OF SNOW SHOULD ACCOMPANY THIS LOW
PRESSURE AREA AND THAT SHOULD STAY MAINLY SOUTH OF UPPER MICHIGAN.
INVERTED SFC TROUGH WILL BE PRESENT TO THE NORTH OF THE MAIN SFC LOW
AND THAT WOULD EXTEND INTO UPR MICHIGAN. SHORTWAVE LIKELY TO BE THE
MAIN FOCUS FOR THE WEATHER OVR CWA ON WEDNESDAY INTO THANKSGIVING IS
IN THE NORTHERN STREAM AND SLIDES OVER THE AREA FM SOUTHERN MANITOBA
AND NORTHWEST ONTARIO IN THE AFTN. OVERALL...PREFER THE OVERALL IDEA
OFFERED BY THE NAM/GFS/ECMWF COMPARED TO THE GEM-NH AS THAT MODEL
SEEMS TOO PHASED WITH THE NORTHERN STREAM AND SOUTHERN STREAM
SHORTWAVES WITH THE RESULT THAT THE THE MAIN SFC LOW IS TOO FAR
NORTH. ECMWF CONTINUES TO SHOW SHARPER TROUGH/CONVERGENCE AND LAKE
ENHANCED SNOW FOR NORTHWEST CWA NOT UNTIL WED NIGHT THEN OVER NCNTRL
CWA ON THANKSGIVING DAY. GFS CONTINUES TO INDICATE WEAKER OVERALL
SYSTEM BUT DOES BRING THE NORTH WIND LAKE EFFECT SNOW SHOWERS IN
EARLIER...MORE SO ON WEDNESDAY AFTN INTO WEDNESDAY NIGHT. GIVEN COLD
POOL OF AIR TO NORTH OF THE SFC TROUGH WITH H85 TEMPS DOWN TO AS LOW
AS -20C THERE WILL BE CERTAINLY BE SOME LAKE EFFECT SNOW SHOWERS
WEDNESDAY INTO THANKSGIVING. IN ADDITION...WILL NEED TO WATCH LAKE
EFFECT OFF LK MICHIGAN IN THE S/SE WINDS AHEAD OF THE SFC TROUGH.
WINDS BACK STEADILY FROM LATE TUESDAY NIGHT INTO WEDNESDAY OVER
NORTHERN LK MICHIGAN. FORECAST SOUNDINGS POINT TO SCT LAKE EFFECT TO
EXPAND OVER MUCH OF THE EASTERN CWA BY LATE WEDNESDAY AS THE ONSHORE
FLOW IS ENHANCED BY THE LARGER SCALE LIFT AND MOISTURE FM THE NEARING
NORTHERN STREAM SHORTWAVE.
SHARPNESS OF SFC TROUGH AND EXTENT OF CONVERGENCE STILL UNCERTAIN
THOUGH WHICH AFFECTS INTENSITY/EXTENT OF THE LES BOTH OFF LK
SUPERIOR AND LK MICHIGAN AND ALSO THE STRENGTH OF WINDS/BLSN NEAR LK
SUPERIOR IN WAKE OF TROUGH. LATEST RUNS OF GFS AND ECMWF KEEP WITH
CONTINUITY COMPARED TO THEIR PREVIOUS RUNS...GIVING NO TREND TO
LATCH ON. THOSE THAT HAVE TRAVEL PLANS WEDNESDAY INTO THANKSGIVING
NEAR LK SUPERIOR AND ALSO OVER MOST OF THE EAST HALF OF UPR MICHIGAN
SHOULD BE AWARE THAT DURING THIS TIME FRAME THERE COULD AT LEAST
LOCALIZED HIGHER IMPACT WEATHER.
HIGH PRESSURE DIVING OVER THE PLAINS WITH RIDGING OVER NORTHERN
ONTARIO EVENTUALLY SHOULD WIN OUT LATER ON THANKSGIVING. THOUGH IF
THE STRONGER TROUGH FM ECMWF IS CORRECT...DIMINISHING TREND IN THE
LAKE EFFECT WOULD BE MORE ON THURSDAY NIGHT. ONCE THE SFC RIDGE
SLIDES EAST ON FRIDAY...UPPER FLOW FLATTENS OUT ALLOWING FOR WARM
AIR ADVECTION TO RAMP UP OVER THE PLAINS. INDICATIONS THAT AT LEAST
ONE SHORTWAVE WILL ALSO BE PROPELLING FROM THE NORTHERN PLAINS
TOWARD THE WESTERN GREAT LAKES. DECENT JET STREAK ALSO FCST OVER THE
PLAINS WHICH SHOULD ENHANCED LIFT ALONG THE TIGHT LOW-LEVEL
BAROCLINIC ZONE. SWATH OF AT LEAST LIGHT SNOW SHOULD RESULT
SOMEWHERE VCNTY OF NORTHERN PLAINS TO THE WESTERN GREAT LAKES.
CONSIDERING THE WAVE THAT WILL GENERATE THE SNOW IS STILL TO EMERGE
FROM UPPER TROUGH OVER NORTHERN PACIFIC VCNTY OF 40N/155W...GFS IS
CONSISTENT IN SHOWING THIS AND GEM-NH IS THERE AS WELL. ECMWF JUST
TRENDED THIS WAY WITH THE 23NOV/12Z RUN. PLENTY OF TIME TO LOOK AT
THE DETAILS BUT DOES APPEAR THAT PTYPE WILL STAY ONLY SNOW AS WARM
AIR AT H85 IS FORECAST TO REMAIN SOUTHWEST OF UPPER LAKES.
MIXED SIGNALS THAT COULD SEE SOME LGT MIXED PRECIP FRIDAY NIGHT INTO
SATURDAY AS THE H9-H8 WARM LAYER ARRIVES. COULD SEE SOME DRIZZLE AND
FOG ISSUES TOO THOUGH AT LEAST RIGHT NOW...GFS/ECMWF ARE NOT SHOWING
DWPNTS AS HIGH AS ARE CURRENTLY OCCURRING OVER AREA. REAL MODEL
DIFFERENCES TO CLOSE THE LONG TERM...WITH 23NOV/12Z ECMWF KEEPING
THE WARM SECTOR OVER THE AREA INTO SUNDAY...WHILE THE GFS SHOVES
SHARPER COLD FRONT OVER THE UPPER GREAT LAKES BY SUNDAY. AT 12Z
SUNDAY...H85 TEMPS VARY FROM -5C OFF THAT RUN OF ECMWF TO -24C
OFF THE GFS. LATEST ECMWF TRENDED TOWARD GFS AS IT NOW SHOWS H85
TEMP THAT SAME TIME OF -16C. USED A CONSENSUS OF THE MODELS UNTIL
THE DIFFERENCES ARE RESOLVED...BUT GIVEN THE TREND FM THE LATEST
ECMWF...WENT WITH A BIT HIGHER POPS AND LOWERED TEMPS SLIGHTLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 239 PM EST MON NOV 24 2014
IFR TO LIFR CONDITIONS WILL PERSIST THIS AFTERNOON AS LAKE EFFECT
SNOW REDUCES VSBYS TO LESS THAN A MILE AT CMX/IWD. SAW STILL
MVFR...BUT EXPECT IFR CONDITIONS TO COMMENCE THERE AS WELL WHEN THE
BETTER LAKE EFFECT SNOW BANDS DEVELOP. IFR CONDITIONS WILL COTNINUE
THROUGH THE OVERNIGHT BEFORE IMPROVING TO MVFR ON TUESDAY AS DRIER
AIR MOVES IN. ALL SITES WILL ALSO SEE NORTH-NORTHEAST WINDS GUST TO
30+ KT THROUGH THIS EVENING CAUSING SOME BLSN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 537 AM EST MON NOV 24 2014
A DEEPENING LOW WILL MOVE TO EAST OF LAKE SUPERIOR TODAY. NORTHERLY
WINDS WILL INCREASE TO GALES 35-45 KTS BY THIS MORNING INTO MONDAY
NIGHT. EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS WED NIGHT INTO THURSDAY AS COLD
AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER
THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
THERE MAY BE A BRIEF PD OF GALES TO 35 KNOTS OVER NCNTRL LAKE
SUPERIOR WED NIGHT. WINDS WILL DECREASE TO LESS THAN 25 KNOTS THU
NIGHT INTO FRI AS A HIGH PRES RIDGE MOVES OVER THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 4 PM EST TUESDAY FOR MIZ006-007-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ TUESDAY FOR
MIZ001>003-009.
LAKESHORE FLOOD ADVISORY UNTIL 6 AM EST TUESDAY FOR MIZ001-003-
005>007.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST TUESDAY FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING UNTIL 4 AM EST TUESDAY FOR LSZ251-267.
GALE WARNING UNTIL 4 AM EST TUESDAY FOR LSZ246>250-265-266.
GALE WARNING UNTIL 2 AM EST TUESDAY FOR LSZ242>245-263-264.
GALE WARNING UNTIL 9 PM EST /8 PM CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...MRD
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
728 AM EST MON NOV 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 537 AM EST MON NOV 24 2014
WV IMAGERY AND RUC ANALYSIS SHOWS A MID-UPR LEVEL TROUGH OVER THE
NRN/CENTRAL PLAINS WITH A COUPLE OF STRONG SHORTWAVES OUT AHEAD OF
THIS TROUGH IN A SW FLOW. ONE SHORTWAVE WAS MOVING ACROSS LAKE HURON
NEARLY CO-LOCATED WITH THE 980 MB SFC LOW WHILE ANOTHER SHORTWAVE
WAS TRIGGERING THUNDERSTORMS AS IT LIFTED THROUGH SRN IL AND SRN IN.
DEFORMATION PCPN SHIELD IN COMMA HEAD OF LAKE HURON SHORTWAVE HAS
BEEN RESPONSIBLE FOR THE LIGHT PCPN OVER MUCH OF WEST AND CENTRAL
UPPER MI THIS MORNING WITH SOME MODERATE RAIN OVER ERN UPPER MI. THE
RAIN OVER THE EXISTING SNOW PACK CONTINUES TO SUPPORT AREAS OF FOG
BUT VSBYS OVER MOST AREAS HAVE RISEN ENOUGH TO CANCEL DENSE FOG
ADVISORY.
TODAY...MODELS AND REGIONAL RADAR IMAGERY SUGGEST THAT THERE MAY BE
A LULL IN THE PCPN BETWEEN THE EXITING NRN LAKE SHRTWV AND THE MID
LEVEL TROUGH MOVING IN FROM THE UPPER MS VALLEY/NRN PLAINS. AS THE
DEEPENING SFC LOW OVER LAKE HURON LIFTS QUICKLY NE THE COLDER AIR
WILL ALSO SLIDE QUICKLY THROUGH UPPER MI WITH THE RAIN CHANGING OVER
TO SNOW FROM 12Z-21Z FROM W TO EAST PER MODEL SNDGS AND 1000-850 MB
LOW-LVL LEVEL THICKNESS. WITH THE LOSS OF THE STRONGER LARGE SCALE
FORCING/DEEP LAYER Q-VECT CONVERGENCE TIL AFTERNOON EXPECT MAINLY
JUST LIGHT TO MODERATE LAKE ENHANCED SNOW OVER THE WEST HALF FOR NNW
FLOW FAVORED LOCATIONS AS 850 MB TEMPS FALL TO NEAR -8C WEST BY 18Z
AND TO AROUND -12C ACROSS WEST AND NCNTRL LOCATIONS BY 00Z. EXPECT
SNOWFALL AMOUNTS IN THE 2 TO 3 RANGE OVER THE WEST WITH GENERALLY
1-2 INCHES NCNTRL...EXCEPT UP TO 3 INCHES POSSIBLE OVER THE HURON
MOUNTAIN AREA. A TIGHT GRADIENT BEHIND THE LOW WILL BRING STRONG
NRLY WINDS WITH GUSTS TO 30-40 MPH PRODUCING SOME BLOWING AND
DRIFTING SNOW.
TONIGHT...MODELS CONTINUE TO SHOW DEEP MOISTURE/Q-VECTOR CONVERGENCE
AS MID-LVL TROUGH LINGERS OVER THE AREA. ALSO MODEL SOUNDINGS
SUGGEST THE POTENTIAL FOR GOOD SNOW GROWTH AT LEAST THIS EVENING AS
BEST MODEL OMEGA/LIFT INTERSECTS DGZ. CONVERGENT NNW FLOW WILL FAVOR
3-5 INCH ACCUMULATIONS OVER THE HIGHER TERRAIN OF THE WEST AND
NCNTRL COUNTIES WITH PERHAPS ISOLATED 6 INCH AMOUNTS POSSIBLE OVER
THE HURON MOUNTAINS. LAKE ENHANCED SNOW MAY TAPER OFF OVER THE WRN
COUNTIES LATE TONIGHT AS BEST FORCING/Q-VECT CONV BEGINS TO SHIFT
EAST.
CURRENT LAKE EFFECT SNOW ADVISORIES STILL ON TRACK FOR ALL OF WEST
AND NORTH CENTRAL UPPER MI WITH THE GREATEST SNOW TOTAL
ACCUMULATIONS OF 5 TO 9 INCHES EXPECTED OVER HIGHER TERRAIN
LOCATIONS NEAR LAKE SUPERIOR INTO TUESDAY. SOME ISOLATED 10" AMOUNTS
MAY BE POSSIBLE OVER THE HURON MOUNTAINS AIDED BY UPSLOPE FM THE
HIGHER TERRAIN THERE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON NOV 24 2014
LIGHT TO MODERATE LAKE EFFECT WILL BE ONGOING TO START TUESDAY MORNING
WITH DELTA T/S OVER 15C AND NNW LOW-LEVEL WINDS IN WAKE OF THE
DEPARTING SFC LOW PRESSURE TROUGH. INVERSIONS UP TO 5KFT DOES PUT MOST
OF THE CLOUD BEARING LAYER IN THE DGZ...BUT WITH INCREASING DRYING
AND SUBSIDENCE ALOFT AS MAIN SHORTWAVE MOVES EAST...EXPECT THE LAKE EFFECT
TO DIMINISH THROUGH THE DAY AS LOW-LEVEL WINDS BECOME ANTICYCLONIC
AS RIDGE MOVES IN. ENDING TIMES FOR CURRENT LAKE EFFECT ADVISORIES
SEEM GOOD BASED ON THE DIMINISHING TRENDS IN SNOW SHOWERS AND WINDS/BLSN.
TUESDAY NIGHT INTO WEDNESDAY ONE SHORTWAVE AND A LOW PRESSURE SYSTEM
IS EXPECTED TO DIP ESE FM THE NORTHERN PLAINS TOWARD THE MIDDLE
MISSISSIPPI RIVER VALLEY. SWATH OF SNOW SHOULD ACCOMPANY THIS LOW
PRESSURE AREA AND THAT SHOULD STAY MAINLY SOUTH OF UPPER MICHIGAN.
INVERTED SFC TROUGH WILL BE PRESENT TO THE NORTH OF THE MAIN SFC LOW
AND THAT WOULD EXTEND INTO UPR MICHIGAN. SHORTWAVE LIKELY TO BE THE
MAIN FOCUS FOR THE WEATHER OVR CWA ON WEDNESDAY INTO THANKSGIVING IS
IN THE NORTHERN STREAM AND SLIDES OVER THE AREA FM SOUTHERN MANITOBA
AND NORTHWEST ONTARIO IN THE AFTN. OVERALL...PREFER THE OVERALL IDEA
OFFERED BY THE NAM/GFS/ECMWF COMPARED TO THE GEM-NH AS THAT MODEL
SEEMS TOO PHASED WITH THE NORTHERN STREAM AND SOUTHERN STREAM
SHORTWAVES WITH THE RESULT THAT THE THE MAIN SFC LOW IS TOO FAR
NORTH. ECMWF CONTINUES TO SHOW SHARPER TROUGH/CONVERGENCE AND LAKE
ENHANCED SNOW FOR NORTHWEST CWA NOT UNTIL WED NIGHT THEN OVER NCNTRL
CWA ON THANKSGIVING DAY. GFS CONTINUES TO INDICATE WEAKER OVERALL
SYSTEM BUT DOES BRING THE NORTH WIND LAKE EFFECT SNOW SHOWERS IN
EARLIER...MORE SO ON WEDNESDAY AFTN INTO WEDNESDAY NIGHT. GIVEN COLD
POOL OF AIR TO NORTH OF THE SFC TROUGH WITH H85 TEMPS DOWN TO AS LOW
AS -20C THERE WILL BE CERTAINLY BE SOME LAKE EFFECT SNOW SHOWERS
WEDNESDAY INTO THANKSGIVING. IN ADDITION...WILL NEED TO WATCH LAKE
EFFECT OFF LK MICHIGAN IN THE S/SE WINDS AHEAD OF THE SFC TROUGH.
WINDS BACK STEADILY FROM LATE TUESDAY NIGHT INTO WEDNESDAY OVER
NORTHERN LK MICHIGAN. FORECAST SOUNDINGS POINT TO SCT LAKE EFFECT TO
EXPAND OVER MUCH OF THE EASTERN CWA BY LATE WEDNESDAY AS THE ONSHORE
FLOW IS ENHANCED BY THE LARGER SCALE LIFT AND MOISTURE FM THE NEARING
NORTHERN STREAM SHORTWAVE.
SHARPNESS OF SFC TROUGH AND EXTENT OF CONVERGENCE STILL UNCERTAIN
THOUGH WHICH AFFECTS INTENSITY/EXTENT OF THE LES BOTH OFF LK
SUPERIOR AND LK MICHIGAN AND ALSO THE STRENGTH OF WINDS/BLSN NEAR LK
SUPERIOR IN WAKE OF TROUGH. LATEST RUNS OF GFS AND ECMWF KEEP WITH
CONTINUITY COMPARED TO THEIR PREVIOUS RUNS...GIVING NO TREND TO
LATCH ON. THOSE THAT HAVE TRAVEL PLANS WEDNESDAY INTO THANKSGIVING
NEAR LK SUPERIOR AND ALSO OVER MOST OF THE EAST HALF OF UPR MICHIGAN
SHOULD BE AWARE THAT DURING THIS TIME FRAME THERE COULD AT LEAST
LOCALIZED HIGHER IMPACT WEATHER.
HIGH PRESSURE DIVING OVER THE PLAINS WITH RIDGING OVER NORTHERN
ONTARIO EVENTUALLY SHOULD WIN OUT LATER ON THANKSGIVING. THOUGH IF
THE STRONGER TROUGH FM ECMWF IS CORRECT...DIMINISHING TREND IN THE
LAKE EFFECT WOULD BE MORE ON THURSDAY NIGHT. ONCE THE SFC RIDGE
SLIDES EAST ON FRIDAY...UPPER FLOW FLATTENS OUT ALLOWING FOR WARM
AIR ADVECTION TO RAMP UP OVER THE PLAINS. INDICATIONS THAT AT LEAST
ONE SHORTWAVE WILL ALSO BE PROPELLING FROM THE NORTHERN PLAINS
TOWARD THE WESTERN GREAT LAKES. DECENT JET STREAK ALSO FCST OVER THE
PLAINS WHICH SHOULD ENHANCED LIFT ALONG THE TIGHT LOW-LEVEL
BAROCLINIC ZONE. SWATH OF AT LEAST LIGHT SNOW SHOULD RESULT
SOMEWHERE VCNTY OF NORTHERN PLAINS TO THE WESTERN GREAT LAKES.
CONSIDERING THE WAVE THAT WILL GENERATE THE SNOW IS STILL TO EMERGE
FROM UPPER TROUGH OVER NORTHERN PACIFIC VCNTY OF 40N/155W...GFS IS
CONSISTENT IN SHOWING THIS AND GEM-NH IS THERE AS WELL. ECMWF JUST
TRENDED THIS WAY WITH THE 23NOV/12Z RUN. PLENTY OF TIME TO LOOK AT
THE DETAILS BUT DOES APPEAR THAT PTYPE WILL STAY ONLY SNOW AS WARM
AIR AT H85 IS FORECAST TO REMAIN SOUTHWEST OF UPPER LAKES.
MIXED SIGNALS THAT COULD SEE SOME LGT MIXED PRECIP FRIDAY NIGHT INTO
SATURDAY AS THE H9-H8 WARM LAYER ARRIVES. COULD SEE SOME DRIZZLE AND
FOG ISSUES TOO THOUGH AT LEAST RIGHT NOW...GFS/ECMWF ARE NOT SHOWING
DWPNTS AS HIGH AS ARE CURRENTLY OCCURRING OVER AREA. REAL MODEL
DIFFERENCES TO CLOSE THE LONG TERM...WITH 23NOV/12Z ECMWF KEEPING
THE WARM SECTOR OVER THE AREA INTO SUNDAY...WHILE THE GFS SHOVES
SHARPER COLD FRONT OVER THE UPPER GREAT LAKES BY SUNDAY. AT 12Z
SUNDAY...H85 TEMPS VARY FROM -5C OFF THAT RUN OF ECMWF TO -24C
OFF THE GFS. LATEST ECMWF TRENDED TOWARD GFS AS IT NOW SHOWS H85
TEMP THAT SAME TIME OF -16C. USED A CONSENSUS OF THE MODELS UNTIL
THE DIFFERENCES ARE RESOLVED...BUT GIVEN THE TREND FM THE LATEST
ECMWF...WENT WITH A BIT HIGHER POPS AND LOWERED TEMPS SLIGHTLY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 721 AM EST MON NOV 24 2014
EXPECT LIFR CIGS TO PERSIST THROUGH THIS MORNING. AS A DEEP LOW
PRESSURE SYSTEM MOVES NORTHEAST OF THE AREA THIS MORNING WINDS WILL
BECOME NNW AND QUICKLY STRENGTHEN WITH ANY RAIN CHANGING TO SNOW.
CIGS MAY IMPROVE SOME THRU PD WITH INCREASED MIXING FROM INFLUX OF
COLDER AIR AND STRONGER WINDS. EXPECT LOWER IFR VSBY ONCE HEAVIER SNOW
SETS UP THIS AFTERNOON INTO THIS EVENING WITH IMPROVEMENT LATE
TONIGHT FROM WEST AS RIDGE BEGINS TO BUILD IN AND SNOW TAPERS OFF.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 537 AM EST MON NOV 24 2014
A DEEPENING LOW WILL MOVE TO EAST OF LAKE SUPERIOR TODAY. NORTHERLY
WINDS WILL INCREASE TO GALES 35-45 KTS BY THIS MORNING INTO MONDAY
NIGHT. EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS WED NIGHT INTO THURSDAY AS COLD
AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER
THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
THERE MAY BE A BRIEF PD OF GALES TO 35 KNOTS OVER NCNTRL LAKE
SUPERIOR WED NIGHT. WINDS WILL DECREASE TO LESS THAN 25 KNOTS THU
NIGHT INTO FRI AS A HIGH PRES RIDGE MOVES OVER THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EST
TUESDAY FOR MIZ006-007-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ TUESDAY FOR
MIZ001>003-009.
LAKESHORE FLOOD ADVISORY FROM 11 AM THIS MORNING TO 6 AM EST
TUESDAY FOR MIZ001-003-005>007.
LAKE EFFECT SNOW ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
TUESDAY FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM THIS AFTERNOON TO 4 AM EST TUESDAY FOR
LSZ251-267.
GALE WARNING UNTIL 4 AM EST TUESDAY FOR LSZ246>250-265-266.
GALE WARNING UNTIL 2 AM EST TUESDAY FOR LSZ242>245-263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TODAY TO 9 PM EST /8 PM
CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
538 AM EST MON NOV 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 537 AM EST MON NOV 24 2014
WV IMAGERY AND RUC ANALYSIS SHOWS A MID-UPR LEVEL TROUGH OVER THE
NRN/CENTRAL PLAINS WITH A COUPLE OF STRONG SHORTWAVES OUT AHEAD OF
THIS TROUGH IN A SW FLOW. ONE SHORTWAVE WAS MOVING ACROSS LAKE HURON
NEARLY CO-LOCATED WITH THE 980 MB SFC LOW WHILE ANOTHER SHORTWAVE
WAS TRIGGERING THUNDERSTORMS AS IT LIFTED THROUGH SRN IL AND SRN IN.
DEFORMATION PCPN SHIELD IN COMMA HEAD OF LAKE HURON SHORTWAVE HAS
BEEN RESPONSIBLE FOR THE LIGHT PCPN OVER MUCH OF WEST AND CENTRAL
UPPER MI THIS MORNING WITH SOME MODERATE RAIN OVER ERN UPPER MI. THE
RAIN OVER THE EXISTING SNOW PACK CONTINUES TO SUPPORT AREAS OF FOG
BUT VSBYS OVER MOST AREAS HAVE RISEN ENOUGH TO CANCEL DENSE FOG
ADVISORY.
TODAY...MODELS AND REGIONAL RADAR IMAGERY SUGGEST THAT THERE MAY BE
A LULL IN THE PCPN BETWEEN THE EXITING NRN LAKE SHRTWV AND THE MID
LEVEL TROUGH MOVING IN FROM THE UPPER MS VALLEY/NRN PLAINS. AS THE
DEEPENING SFC LOW OVER LAKE HURON LIFTS QUICKLY NE THE COLDER AIR
WILL ALSO SLIDE QUICKLY THROUGH UPPER MI WITH THE RAIN CHANGING OVER
TO SNOW FROM 12Z-21Z FROM W TO EAST PER MODEL SNDGS AND 1000-850 MB
LOW-LVL LEVEL THICKNESS. WITH THE LOSS OF THE STRONGER LARGE SCALE
FORCING/DEEP LAYER Q-VECT CONVERGENCE TIL AFTERNOON EXPECT MAINLY
JUST LIGHT TO MODERATE LAKE ENHANCED SNOW OVER THE WEST HALF FOR NNW
FLOW FAVORED LOCATIONS AS 850 MB TEMPS FALL TO NEAR -8C WEST BY 18Z
AND TO AROUND -12C ACROSS WEST AND NCNTRL LOCATIONS BY 00Z. EXPECT
SNOWFALL AMOUNTS IN THE 2 TO 3 RANGE OVER THE WEST WITH GENERALLY
1-2 INCHES NCNTRL...EXCEPT UP TO 3 INCHES POSSIBLE OVER THE HURON
MOUNTAIN AREA. A TIGHT GRADIENT BEHIND THE LOW WILL BRING STRONG
NRLY WINDS WITH GUSTS TO 30-40 MPH PRODUCING SOME BLOWING AND
DRIFTING SNOW.
TONIGHT...MODELS CONTINUE TO SHOW DEEP MOISTURE/Q-VECTOR CONVERGENCE
AS MID-LVL TROUGH LINGERS OVER THE AREA. ALSO MODEL SOUNDINGS
SUGGEST THE POTENTIAL FOR GOOD SNOW GROWTH AT LEAST THIS EVENING AS
BEST MODEL OMEGA/LIFT INTERSECTS DGZ. CONVERGENT NNW FLOW WILL FAVOR
3-5 INCH ACCUMULATIONS OVER THE HIGHER TERRAIN OF THE WEST AND
NCNTRL COUNTIES WITH PERHAPS ISOLATED 6 INCH AMOUNTS POSSIBLE OVER
THE HURON MOUNTAINS. LAKE ENHANCED SNOW MAY TAPER OFF OVER THE WRN
COUNTIES LATE TONIGHT AS BEST FORCING/Q-VECT CONV BEGINS TO SHIFT
EAST.
CURRENT LAKE EFFECT SNOW ADVISORIES STILL ON TRACK FOR ALL OF WEST
AND NORTH CENTRAL UPPER MI WITH THE GREATEST SNOW TOTAL
ACCUMULATIONS OF 5 TO 9 INCHES EXPECTED OVER HIGHER TERRAIN
LOCATIONS NEAR LAKE SUPERIOR INTO TUESDAY. SOME ISOLATED 10" AMOUNTS
MAY BE POSSIBLE OVER THE HURON MOUNTAINS AIDED BY UPSLOPE FM THE
HIGHER TERRAIN THERE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON NOV 24 2014
LIGHT TO MODERATE LAKE EFFECT WILL BE ONGOING TO START TUESDAY MORNING
WITH DELTA T/S OVER 15C AND NNW LOW-LEVEL WINDS IN WAKE OF THE
DEPARTING SFC LOW PRESSURE TROUGH. INVERSIONS UP TO 5KFT DOES PUT MOST
OF THE CLOUD BEARING LAYER IN THE DGZ...BUT WITH INCREASING DRYING
AND SUBSIDENCE ALOFT AS MAIN SHORTWAVE MOVES EAST...EXPECT THE LAKE EFFECT
TO DIMINISH THROUGH THE DAY AS LOW-LEVEL WINDS BECOME ANTICYCLONIC
AS RIDGE MOVES IN. ENDING TIMES FOR CURRENT LAKE EFFECT ADVISORIES
SEEM GOOD BASED ON THE DIMINISHING TRENDS IN SNOW SHOWERS AND WINDS/BLSN.
TUESDAY NIGHT INTO WEDNESDAY ONE SHORTWAVE AND A LOW PRESSURE SYSTEM
IS EXPECTED TO DIP ESE FM THE NORTHERN PLAINS TOWARD THE MIDDLE
MISSISSIPPI RIVER VALLEY. SWATH OF SNOW SHOULD ACCOMPANY THIS LOW
PRESSURE AREA AND THAT SHOULD STAY MAINLY SOUTH OF UPPER MICHIGAN.
INVERTED SFC TROUGH WILL BE PRESENT TO THE NORTH OF THE MAIN SFC LOW
AND THAT WOULD EXTEND INTO UPR MICHIGAN. SHORTWAVE LIKELY TO BE THE
MAIN FOCUS FOR THE WEATHER OVR CWA ON WEDNESDAY INTO THANKSGIVING IS
IN THE NORTHERN STREAM AND SLIDES OVER THE AREA FM SOUTHERN MANITOBA
AND NORTHWEST ONTARIO IN THE AFTN. OVERALL...PREFER THE OVERALL IDEA
OFFERED BY THE NAM/GFS/ECMWF COMPARED TO THE GEM-NH AS THAT MODEL
SEEMS TOO PHASED WITH THE NORTHERN STREAM AND SOUTHERN STREAM
SHORTWAVES WITH THE RESULT THAT THE THE MAIN SFC LOW IS TOO FAR
NORTH. ECMWF CONTINUES TO SHOW SHARPER TROUGH/CONVERGENCE AND LAKE
ENHANCED SNOW FOR NORTHWEST CWA NOT UNTIL WED NIGHT THEN OVER NCNTRL
CWA ON THANKSGIVING DAY. GFS CONTINUES TO INDICATE WEAKER OVERALL
SYSTEM BUT DOES BRING THE NORTH WIND LAKE EFFECT SNOW SHOWERS IN
EARLIER...MORE SO ON WEDNESDAY AFTN INTO WEDNESDAY NIGHT. GIVEN COLD
POOL OF AIR TO NORTH OF THE SFC TROUGH WITH H85 TEMPS DOWN TO AS LOW
AS -20C THERE WILL BE CERTAINLY BE SOME LAKE EFFECT SNOW SHOWERS
WEDNESDAY INTO THANKSGIVING. IN ADDITION...WILL NEED TO WATCH LAKE
EFFECT OFF LK MICHIGAN IN THE S/SE WINDS AHEAD OF THE SFC TROUGH.
WINDS BACK STEADILY FROM LATE TUESDAY NIGHT INTO WEDNESDAY OVER
NORTHERN LK MICHIGAN. FORECAST SOUNDINGS POINT TO SCT LAKE EFFECT TO
EXPAND OVER MUCH OF THE EASTERN CWA BY LATE WEDNESDAY AS THE ONSHORE
FLOW IS ENHANCED BY THE LARGER SCALE LIFT AND MOISTURE FM THE NEARING
NORTHERN STREAM SHORTWAVE.
SHARPNESS OF SFC TROUGH AND EXTENT OF CONVERGENCE STILL UNCERTAIN
THOUGH WHICH AFFECTS INTENSITY/EXTENT OF THE LES BOTH OFF LK
SUPERIOR AND LK MICHIGAN AND ALSO THE STRENGTH OF WINDS/BLSN NEAR LK
SUPERIOR IN WAKE OF TROUGH. LATEST RUNS OF GFS AND ECMWF KEEP WITH
CONTINUITY COMPARED TO THEIR PREVIOUS RUNS...GIVING NO TREND TO
LATCH ON. THOSE THAT HAVE TRAVEL PLANS WEDNESDAY INTO THANKSGIVING
NEAR LK SUPERIOR AND ALSO OVER MOST OF THE EAST HALF OF UPR MICHIGAN
SHOULD BE AWARE THAT DURING THIS TIME FRAME THERE COULD AT LEAST
LOCALIZED HIGHER IMPACT WEATHER.
HIGH PRESSURE DIVING OVER THE PLAINS WITH RIDGING OVER NORTHERN
ONTARIO EVENTUALLY SHOULD WIN OUT LATER ON THANKSGIVING. THOUGH IF
THE STRONGER TROUGH FM ECMWF IS CORRECT...DIMINISHING TREND IN THE
LAKE EFFECT WOULD BE MORE ON THURSDAY NIGHT. ONCE THE SFC RIDGE
SLIDES EAST ON FRIDAY...UPPER FLOW FLATTENS OUT ALLOWING FOR WARM
AIR ADVECTION TO RAMP UP OVER THE PLAINS. INDICATIONS THAT AT LEAST
ONE SHORTWAVE WILL ALSO BE PROPELLING FROM THE NORTHERN PLAINS
TOWARD THE WESTERN GREAT LAKES. DECENT JET STREAK ALSO FCST OVER THE
PLAINS WHICH SHOULD ENHANCED LIFT ALONG THE TIGHT LOW-LEVEL
BAROCLINIC ZONE. SWATH OF AT LEAST LIGHT SNOW SHOULD RESULT
SOMEWHERE VCNTY OF NORTHERN PLAINS TO THE WESTERN GREAT LAKES.
CONSIDERING THE WAVE THAT WILL GENERATE THE SNOW IS STILL TO EMERGE
FROM UPPER TROUGH OVER NORTHERN PACIFIC VCNTY OF 40N/155W...GFS IS
CONSISTENT IN SHOWING THIS AND GEM-NH IS THERE AS WELL. ECMWF JUST
TRENDED THIS WAY WITH THE 23NOV/12Z RUN. PLENTY OF TIME TO LOOK AT
THE DETAILS BUT DOES APPEAR THAT PTYPE WILL STAY ONLY SNOW AS WARM
AIR AT H85 IS FORECAST TO REMAIN SOUTHWEST OF UPPER LAKES.
MIXED SIGNALS THAT COULD SEE SOME LGT MIXED PRECIP FRIDAY NIGHT INTO
SATURDAY AS THE H9-H8 WARM LAYER ARRIVES. COULD SEE SOME DRIZZLE AND
FOG ISSUES TOO THOUGH AT LEAST RIGHT NOW...GFS/ECMWF ARE NOT SHOWING
DWPNTS AS HIGH AS ARE CURRENTLY OCCURRING OVER AREA. REAL MODEL
DIFFERENCES TO CLOSE THE LONG TERM...WITH 23NOV/12Z ECMWF KEEPING
THE WARM SECTOR OVER THE AREA INTO SUNDAY...WHILE THE GFS SHOVES
SHARPER COLD FRONT OVER THE UPPER GREAT LAKES BY SUNDAY. AT 12Z
SUNDAY...H85 TEMPS VARY FROM -5C OFF THAT RUN OF ECMWF TO -24C
OFF THE GFS. LATEST ECMWF TRENDED TOWARD GFS AS IT NOW SHOWS H85
TEMP THAT SAME TIME OF -16C. USED A CONSENSUS OF THE MODELS UNTIL
THE DIFFERENCES ARE RESOLVED...BUT GIVEN THE TREND FM THE LATEST
ECMWF...WENT WITH A BIT HIGHER POPS AND LOWERED TEMPS SLIGHTLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1233 AM EST MON NOV 24 2014
PERSISTENT LOW CIGS AND FOG WILL CONTINUE OVERNIGHT WITH VLIFR TO
LIFR CONDITIONS PERSISTING. AS A DEEP LOW PRESSURE SYSTEM MOVES EAST
OF THE AREA MONDAY MORNING WINDS WILL BECOME NORTH AND QUICKLY
STRENGTHEN WITH ANY RAIN CHANGING TO SNOW. LOW CIGS AND VIS WILL
CONTINUE AT ALL TAF SITES THROUGH THE REST OF THE FORECAST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 537 AM EST MON NOV 24 2014
A DEEPENING LOW WILL MOVE TO EAST OF LAKE SUPERIOR TODAY. NORTHERLY
WINDS WILL INCREASE TO GALES 35-45 KTS BY THIS MORNING INTO MONDAY
NIGHT. EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS TUESDAY INTO
WEDNESDAY...THEN INCREASE TO 30 KTS WED NIGHT INTO THURSDAY AS COLD
AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER
THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
THERE MAY BE A BRIEF PD OF GALES TO 35 KNOTS OVER NCNTRL LAKE
SUPERIOR WED NIGHT. WINDS WILL DECREASE TO LESS THAN 25 KNOTS THU
NIGHT INTO FRI AS A HIGH PRES RIDGE MOVES OVER THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EST
TUESDAY FOR MIZ006-007-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ TUESDAY FOR
MIZ001>003-009.
LAKESHORE FLOOD ADVISORY FROM 11 AM THIS MORNING TO 6 AM EST
TUESDAY FOR MIZ001-003-005>007.
LAKE EFFECT SNOW ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
TUESDAY FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM THIS AFTERNOON TO 4 AM EST TUESDAY FOR
LSZ251-267.
GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING UNTIL 2 AM EST TUESDAY FOR LSZ242>245-263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TODAY TO 9 PM EST /8 PM
CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
415 AM EST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 444 PM EST SUN NOV 23 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A COMPLEX MID/UPPER LEVEL
TROUGH ACROSS THE CENTRAL CONUS. THE MORE PROMINENT SHORTWAVE
TROUGHS WERE LOCATED OVER THE DAKOTAS...NEW MEXICO...AND NRN
MS. AT THE SFC...A TROUGH AND FRONTAL BOUNDARY EXTENDED FROM NE
MN THROUGH CNTRL IA TO LOW PRES OVER ERN OK. A BROAD SRLY FLOW OF
GULF MOISTURE INTO THE NRN LAKES HAS RESULTED IN AREAS OF DENSE FOG
OVER THE EXTENSIVE SNOW COVER. A WEAKER SHRTWV OVER WI AND
ASSOCIATED 850-700 MB FGEN SUPPORTED AN AREA OF RAIN THAT WAS
EXPANDING INTO SRN UPPER MI.
TONIGHT...EXPECT THAT THE RAIN WILL CONTINUE TO DEVELOP INTO UPPER
MI THIS EVENING...ESPECIALLY ACROSS THE SE HALF IN PROXIMITY TO THE
STRONGEST FGEN AND ISENTROPIC LIFT. ALTHOUGH AREAS OF DENSE FOG MAY
PERSIST INTO THIS EVENING...THE RAIN SHOULD HELP SCOUR OUT SOME OF
THE FOG FOR SLIGHTLY BETTER VSBY. BY LATE TONIGHT...THE RAIN IS
EXPECTED TO CONTINUE TO INCREASE IN COVERAGE/INTENSITY AS THE MID
LEVEL TROUGH DEEPENS...THE MS SHRTWV LIFTS TO THE GREAT LAKES WITH
INCREASING 700-500 MB QVECTOR CONV.
MONDAY...MODELS SUGGEST THAT THERE MAY BE A LULL IN THE PCPN
BETWEEN THE EXITING NRN LAKE SHRTWV AND THE MID LEVEL TROUGH MOVING
IN FROM THE UPPER MS VALLEY. AS THE DEEPENING SFC LOW NEAR THE
STRAITS AT 12Z/MON LIFTS QUICKLY TO THE NE THE COLDER AIR WILL ALSO
SLIDE QUICKLY THROUGH UPPER MI WITH THE RAIN CHANGING OVER TO SNOW
FROM 12Z-21Z FROM W TO EAST. THE PCPN CHANGEOVER WAS DELAYED
SLIGHTLY...PER MODEL TRENDS WITH A BLEND OF THE 12Z NAM AND REGIONAL
GEM 1000-850 LOW LEVEL THICKNESS USED FOR THE RAIN SNOW LINE. WITH
THE LOSS OF THE STRONGER LARGE SCALE FORCING/LIFT TIL AFTERNOON
MAINLY JUST LIGHT TO MODERATE LAKE ENAHANCED SNOW IS EXPECTED OVER
THE WEST HALF FOR NNW FLOW FAVORED LOCATIONS AS 850 MB TEMPS FALL TO
NEAR -8C WEST BY 18Z AND TO AROUND -12C ACROSS WEST AND CNTRL
LOCATIONS BY 00Z. SNOWFALL AMOUNTS IN THE 2 TO 4 RANGE WILL BE
POSSIBLE OVER THE WEST WITH ONLY AROUND AN INCH CENTRAL. A TIGHT
GRADIENT BEHIND THE LOW WILL BRING STRONG NRLY WINDS INTO THE AREA
PRODUCING SOME BLOWING AND DRIFTING SNOW.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON NOV 24 2014
LIGHT TO MODERATE LAKE EFFECT WILL BE ONGOING TO START TUESDAY MORNING
WITH DELTA T/S OVER 15C AND NNW LOW-LEVEL WINDS IN WAKE OF THE
DEPARTING SFC LOW PRESSURE TROUGH. INVERSIONS UP TO 5KFT DOES PUT MOST
OF THE CLOUD BEARING LAYER IN THE DGZ...BUT WITH INCREASING DRYING
AND SUBSIDENCE ALOFT AS MAIN SHORTWAVE MOVES EAST...EXPECT THE LAKE EFFECT
TO DIMINISH THROUGH THE DAY AS LOW-LEVEL WINDS BECOME ANTICYCLONIC
AS RIDGE MOVES IN. ENDING TIMES FOR CURRENT LAKE EFFECT ADVISORIES
SEEM GOOD BASED ON THE DIMINISHING TRENDS IN SNOW SHOWERS AND WINDS/BLSN.
TUESDAY NIGHT INTO WEDNESDAY ONE SHORTWAVE AND A LOW PRESSURE SYSTEM
IS EXPECTED TO DIP ESE FM THE NORTHERN PLAINS TOWARD THE MIDDLE
MISSISSIPPI RIVER VALLEY. SWATH OF SNOW SHOULD ACCOMPANY THIS LOW
PRESSURE AREA AND THAT SHOULD STAY MAINLY SOUTH OF UPPER MICHIGAN.
INVERTED SFC TROUGH WILL BE PRESENT TO THE NORTH OF THE MAIN SFC LOW
AND THAT WOULD EXTEND INTO UPR MICHIGAN. SHORTWAVE LIKELY TO BE THE
MAIN FOCUS FOR THE WEATHER OVR CWA ON WEDNESDAY INTO THANKSGIVING IS
IN THE NORTHERN STREAM AND SLIDES OVER THE AREA FM SOUTHERN MANITOBA
AND NORTHWEST ONTARIO IN THE AFTN. OVERALL...PREFER THE OVERALL IDEA
OFFERED BY THE NAM/GFS/ECMWF COMPARED TO THE GEM-NH AS THAT MODEL
SEEMS TOO PHASED WITH THE NORTHERN STREAM AND SOUTHERN STREAM
SHORTWAVES WITH THE RESULT THAT THE THE MAIN SFC LOW IS TOO FAR
NORTH. ECMWF CONTINUES TO SHOW SHARPER TROUGH/CONVERGENCE AND LAKE
ENHANCED SNOW FOR NORTHWEST CWA NOT UNTIL WED NIGHT THEN OVER NCNTRL
CWA ON THANKSGIVING DAY. GFS CONTINUES TO INDICATE WEAKER OVERALL
SYSTEM BUT DOES BRING THE NORTH WIND LAKE EFFECT SNOW SHOWERS IN
EARLIER...MORE SO ON WEDNESDAY AFTN INTO WEDNESDAY NIGHT. GIVEN COLD
POOL OF AIR TO NORTH OF THE SFC TROUGH WITH H85 TEMPS DOWN TO AS LOW
AS -20C THERE WILL BE CERTAINLY BE SOME LAKE EFFECT SNOW SHOWERS
WEDNESDAY INTO THANKSGIVING. IN ADDITION...WILL NEED TO WATCH LAKE
EFFECT OFF LK MICHIGAN IN THE S/SE WINDS AHEAD OF THE SFC TROUGH.
WINDS BACK STEADILY FROM LATE TUESDAY NIGHT INTO WEDNESDAY OVER
NORTHERN LK MICHIGAN. FORECAST SOUNDINGS POINT TO SCT LAKE EFFECT TO
EXPAND OVER MUCH OF THE EASTERN CWA BY LATE WEDNESDAY AS THE ONSHORE
FLOW IS ENHANCED BY THE LARGER SCALE LIFT AND MOISTURE FM THE NEARING
NORTHERN STREAM SHORTWAVE.
SHARPNESS OF SFC TROUGH AND EXTENT OF CONVERGENCE STILL UNCERTAIN
THOUGH WHICH AFFECTS INTENSITY/EXTENT OF THE LES BOTH OFF LK
SUPERIOR AND LK MICHIGAN AND ALSO THE STRENGTH OF WINDS/BLSN NEAR LK
SUPERIOR IN WAKE OF TROUGH. LATEST RUNS OF GFS AND ECMWF KEEP WITH
CONTINUITY COMPARED TO THEIR PREVIOUS RUNS...GIVING NO TREND TO
LATCH ON. THOSE THAT HAVE TRAVEL PLANS WEDNESDAY INTO THANKSGIVING
NEAR LK SUPERIOR AND ALSO OVER MOST OF THE EAST HALF OF UPR MICHIGAN
SHOULD BE AWARE THAT DURING THIS TIME FRAME THERE COULD AT LEAST
LOCALIZED HIGHER IMPACT WEATHER.
HIGH PRESSURE DIVING OVER THE PLAINS WITH RIDGING OVER NORTHERN
ONTARIO EVENTUALLY SHOULD WIN OUT LATER ON THANKSGIVING. THOUGH IF
THE STRONGER TROUGH FM ECMWF IS CORRECT...DIMINISHING TREND IN THE
LAKE EFFECT WOULD BE MORE ON THURSDAY NIGHT. ONCE THE SFC RIDGE
SLIDES EAST ON FRIDAY...UPPER FLOW FLATTENS OUT ALLOWING FOR WARM
AIR ADVECTION TO RAMP UP OVER THE PLAINS. INDICATIONS THAT AT LEAST
ONE SHORTWAVE WILL ALSO BE PROPELLING FROM THE NORTHERN PLAINS
TOWARD THE WESTERN GREAT LAKES. DECENT JET STREAK ALSO FCST OVER THE
PLAINS WHICH SHOULD ENHANCED LIFT ALONG THE TIGHT LOW-LEVEL
BAROCLINIC ZONE. SWATH OF AT LEAST LIGHT SNOW SHOULD RESULT
SOMEWHERE VCNTY OF NORTHERN PLAINS TO THE WESTERN GREAT LAKES.
CONSIDERING THE WAVE THAT WILL GENERATE THE SNOW IS STILL TO EMERGE
FROM UPPER TROUGH OVER NORTHERN PACIFIC VCNTY OF 40N/155W...GFS IS
CONSISTENT IN SHOWING THIS AND GEM-NH IS THERE AS WELL. ECMWF JUST
TRENDED THIS WAY WITH THE 23NOV/12Z RUN. PLENTY OF TIME TO LOOK AT
THE DETAILS BUT DOES APPEAR THAT PTYPE WILL STAY ONLY SNOW AS WARM
AIR AT H85 IS FORECAST TO REMAIN SOUTHWEST OF UPPER LAKES.
MIXED SIGNALS THAT COULD SEE SOME LGT MIXED PRECIP FRIDAY NIGHT INTO
SATURDAY AS THE H9-H8 WARM LAYER ARRIVES. COULD SEE SOME DRIZZLE AND
FOG ISSUES TOO THOUGH AT LEAST RIGHT NOW...GFS/ECMWF ARE NOT SHOWING
DWPNTS AS HIGH AS ARE CURRENTLY OCCURRING OVER AREA. REAL MODEL
DIFFERENCES TO CLOSE THE LONG TERM...WITH 23NOV/12Z ECMWF KEEPING
THE WARM SECTOR OVER THE AREA INTO SUNDAY...WHILE THE GFS SHOVES
SHARPER COLD FRONT OVER THE UPPER GREAT LAKES BY SUNDAY. AT 12Z
SUNDAY...H85 TEMPS VARY FROM -5C OFF THAT RUN OF ECMWF TO -24C
OFF THE GFS. LATEST ECMWF TRENDED TOWARD GFS AS IT NOW SHOWS H85
TEMP THAT SAME TIME OF -16C. USED A CONSENSUS OF THE MODELS UNTIL
THE DIFFERENCES ARE RESOLVED...BUT GIVEN THE TREND FM THE LATEST
ECMWF...WENT WITH A BIT HIGHER POPS AND LOWERED TEMPS SLIGHTLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1233 AM EST MON NOV 24 2014
PERSISTENT LOW CIGS AND FOG WILL CONTINUE OVERNIGHT WITH VLIFR TO
LIFR CONDITIONS PERSISTING. AS A DEEP LOW PRESSURE SYSTEM MOVES EAST
OF THE AREA MONDAY MORNING WINDS WILL BECOME NORTH AND QUICKLY
STRENGTHEN WITH ANY RAIN CHANGING TO SNOW. LOW CIGS AND VIS WILL
CONTINUE AT ALL TAF SITES THROUGH THE REST OF THE FORECAST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 444 PM EST SUN NOV 23 2014
WINDS WILL BE VARIABLE TONIGHT AS TROUGH CROSSES LAKE SUPERIOR. A
DEEPENING LOW WILL MOVE TO EAST OF LAKE SUPERIOR ON MONDAY.
NORTHERLY WINDS WILL INCREASE TO GALES 35-45 KTS BY MONDAY MORNING
INTO MONDAY NIGHT. EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS
TUESDAY INTO WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD
AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER
THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EST
TUESDAY FOR MIZ006-007-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST /6 AM CST/ TUESDAY FOR
MIZ001>003-009.
LAKESHORE FLOOD ADVISORY FROM 11 AM THIS MORNING TO 6 AM EST
TUESDAY FOR MIZ001-003-005-006.
LAKE EFFECT SNOW ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
TUESDAY FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM THIS AFTERNOON TO 4 AM EST TUESDAY FOR
LSZ251-267.
GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING UNTIL 2 AM EST TUESDAY FOR LSZ242>245-263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TODAY TO 9 PM EST /8 PM
CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1234 AM EST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 444 PM EST SUN NOV 23 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A COMPLEX MID/UPPER LEVEL
TROUGH ACROSS THE CENTRAL CONUS. THE MORE PROMINENT SHORTWAVE
TROUGHS WERE LOCATED OVER THE DAKOTAS...NEW MEXICO...AND NRN
MS. AT THE SFC...A TROUGH AND FRONTAL BOUNDARY EXTENDED FROM NE
MN THROUGH CNTRL IA TO LOW PRES OVER ERN OK. A BROAD SRLY FLOW OF
GULF MOISTURE INTO THE NRN LAKES HAS RESULTED IN AREAS OF DENSE FOG
OVER THE EXTENSIVE SNOW COVER. A WEAKER SHRTWV OVER WI AND
ASSOCIATED 850-700 MB FGEN SUPPORTED AN AREA OF RAIN THAT WAS
EXPANDING INTO SRN UPPER MI.
TONIGHT...EXPECT THAT THE RAIN WILL CONTINUE TO DEVELOP INTO UPPER
MI THIS EVENING...ESPECIALLY ACROSS THE SE HALF IN PROXIMITY TO THE
STRONGEST FGEN AND ISENTROPIC LIFT. ALTHOUGH AREAS OF DENSE FOG MAY
PERSIST INTO THIS EVENING...THE RAIN SHOULD HELP SCOUR OUT SOME OF
THE FOG FOR SLIGHTLY BETTER VSBY. BY LATE TONIGHT...THE RAIN IS
EXPECTED TO CONTINUE TO INCREASE IN COVERAGE/INTENSITY AS THE MID
LEVEL TROUGH DEEPENS...THE MS SHRTWV LIFTS TO THE GREAT LAKES WITH
INCREASING 700-500 MB QVECTOR CONV.
MONDAY...MODELS SUGGEST THAT THERE MAY BE A LULL IN THE PCPN
BETWEEN THE EXITING NRN LAKE SHRTWV AND THE MID LEVEL TROUGH MOVING
IN FROM THE UPPER MS VALLEY. AS THE DEEPENING SFC LOW NEAR THE
STRAITS AT 12Z/MON LIFTS QUICKLY TO THE NE THE COLDER AIR WILL ALSO
SLIDE QUICKLY THROUGH UPPER MI WITH THE RAIN CHANGING OVER TO SNOW
FROM 12Z-21Z FROM W TO EAST. THE PCPN CHANGEOVER WAS DELAYED
SLIGHTLY...PER MODEL TRENDS WITH A BLEND OF THE 12Z NAM AND REGIONAL
GEM 1000-850 LOW LEVEL THICKNESS USED FOR THE RAIN SNOW LINE. WITH
THE LOSS OF THE STRONGER LARGE SCALE FORCING/LIFT TIL AFTERNOON
MAINLY JUST LIGHT TO MODERATE LAKE ENAHANCED SNOW IS EXPECTED OVER
THE WEST HALF FOR NNW FLOW FAVORED LOCATIONS AS 850 MB TEMPS FALL TO
NEAR -8C WEST BY 18Z AND TO AROUND -12C ACROSS WEST AND CNTRL
LOCATIONS BY 00Z. SNOWFALL AMOUNTS IN THE 2 TO 4 RANGE WILL BE
POSSIBLE OVER THE WEST WITH ONLY AROUND AN INCH CENTRAL. A TIGHT
GRADIENT BEHIND THE LOW WILL BRING STRONG NRLY WINDS INTO THE AREA
PRODUCING SOME BLOWING AND DRIFTING SNOW.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 303 PM EST SUN NOV 23 2014
AT 00Z TUE...A SHORTWAVE WILL BE E OF THE CWA WITH THE ASSOCIATED
SFC LOW NEAR JAMES BAY. A WEAKENING UPPER TROUGH WILL BE OVER THE
FAR WRN CWA...WITH A RIDGE NW OF THE TROUGH. THE 12Z/23 NAM HAS COME
INTO BETTER AGREEMENT WITH 12Z/23 GFS AND 00Z/23 ECMWF IN SHOWING
LESS PHASING BETWEEN THE TWO FEATURES...AND THEREFORE HAVING MOST
/BUT NOT ALL/ OF THE SYNOPTIC SNOW NE OF THE CWA BY 00Z TUE. PRECIP
WILL BE ALL SNOW BY 00Z TUE AS 850MB TEMPS WILL FALL TO AOB -12C BY
12Z. WITH THE COLD AIRMASS...LAKE ENHANCEMENT WILL OCCUR IN NNW WIND
SNOWBELTS ALONG AND AHEAD OF THE TROUGH THAT WILL MOVE THROUGH THE
CWA BY 18Z TUE. BEHIND THE TROUGH...WINDS BECOME INCREASINGLY
ANTICYCLONIC...AND LOW LEVEL AIRMASS DRIER...AS THE RIDGE MOVES IN.
WILL CERTAINLY SEE DIMINISHING PRECIP COVERAGE/INTENSITY LATER TUE
INTO TUE NIGHT...BUT LES WILL NOT COMPLETELY END AS LOW LEVEL WINDS
FOCUS LES MORE OVER THE KEWEENAW PENINSULA. WNW WIND SNOWBELTS OF
THE NRN HURON MOUNTAINS AND OVER ALGER COUNTY WILL BE FAVORED FOR
THE GREATEST SNOWFALL AMOUNTS...WITH EXPECTATIONS OF 6-8 INCHES OF
SNOW MON NIGHT AND TUE IN THESE FAVORED LOCATIONS. ELSEWHERE NEAR
LAKE SUPERIOR AROUND 4 INCHES IS EXPECTED MON NIGHT/TUE...WITH LESS
AMOUNTS OF 1-3 INCHES INLAND. AFTER COORDINATION WITH SHORT TERM
SHIFT...LAKE EFFECT SNOW ADVISORIES HAVE BEEN ISSUED FOR ALL
COUNTIES ALONG LAKE SUPERIOR. AT LEAST FOR MON NIGHT/TUE...SNOW TO
LIQUID RATIOS SHOULD BE HIGH ENOUGH FOR THE LAKE EFFECT HEADLINE
INSTEAD OF WINTER WEATHER ADVISORIES. ALSO...BLOWING SNOW WILL OCCUR
ALONG LAKE SUPERIOR.
CONFIDENCE DECREASES SIGNIFICANTLY FOR WED THROUGH NEXT WEEKEND. FOR
WED INTO THU...MODELS AGREE IN SHOWING TWO SHORTWAVES MOVING INTO
THE CENTRAL CENTRAL U.S. WED...BUT DISAGREE ON THE
STRENGTH/TRACK/PHASING OF THE TWO WAVES...WHICH LEADS TO A WIDE
VARIETY OF SOLUTIONS FOR THE CWA. THE ECMWF PHASES THE WAVES OVER
THE REGION...WHICH LEADS TO A 1003MB SFC LOW MOVING FROM NEAR MPX AT
12Z WED TO LAKE HURON AT 12Z THU. THIS SOLUTION WOULD RESULT IN
SIGNIFICANT SNOWFALL AMOUNTS ACROSS THE CWA WED INTO THU. THE GFS
KEEP THE WAVES OUT OF PHASE AND THE SRN MOST WAVE MUCH FARTHER
S...LEAVING JUST A LITTLE LAKE ENHANCEMENT WED INTO WED NIGHT AS THE
NRN SHORTWAVE CROSSES THE AREA. OTHER MODELS HAVE VARYING SOLUTIONS
BETWEEN THESE TWO EXTREMES. NOT REALLY ABLE TO PICK BETWEEN THE
MODELS GIVEN THE NORMAL LOW CONFIDENCE WITH SHORTWAVE ENERGY AND
GENERALLY GOOD RUN TO RUN CONTINUITY OF THE GFS AND ECMWF WITH THIS
SYSTEM.
REGARDLESS OF SOLUTION...SHOULD SEE LES THU INTO THU NIGHT IN NW
WIND SNOWBELTS UNDER -18C TO -20C 850MB TEMPS. HOWEVER...THE GFS
THEN BRINGS WINDS OUT OF THE SW THU NIGHT AHEAD OF A STRONG CLIPPER
SYSTEM IT SHOWS MOVING INTO THE NRN PLAINS THU NIGHT AND ACROSS THE
CWA FRI NIGHT. ALL THE WHILE...THE ECMWF SHOWS A STRONG SFC HIGH
MOVING FROM THE NRN PLAINS TO THE MID MISSISSIPPI VALLEY. THE ECMWF
WOULD KEEP LES GOING IN NW-WNW SNOWBELTS THROUGH FRI...WHILE THE GFS
SOLUTION WOULD OBVIOUSLY NOT GIVEN THE CHANGE IN WINDS WITH THE SFC
LOW MOVING ACROSS THE CWA AND 850MB TEMPS INCREASE TO AROUND
0C...BUT DOES BRING LES BACK ON SAT BEHIND THE CLIPPER. MODELS DO
SHOW SOME AGREEMENT IN LOW LEVEL WINDS BECOMING FROM THE WSW BY SUN
WITH CONTINUED /BUT LIGHTER/ LES. WILL STICK CLOSER TO THE PREVIOUS
FORECAST GIVEN THE HIGH UNCERTAINTY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1233 AM EST MON NOV 24 2014
PERSISTENT LOW CIGS AND FOG WILL CONTINUE OVERNIGHT WITH VLIFR TO
LIFR CONDITIONS PERSISTING. AS A DEEP LOW PRESSURE SYSTEM MOVES EAST
OF THE AREA MONDAY MORNING WINDS WILL BECOME NORTH AND QUICKLY
STRENGTHEN WITH ANY RAIN CHANGING TO SNOW. LOW CIGS AND VIS WILL
CONTINUE AT ALL TAF SITES THROUGH THE REST OF THE FORECAST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 444 PM EST SUN NOV 23 2014
WINDS WILL BE VARIABLE TONIGHT AS TROUGH CROSSES LAKE SUPERIOR. A
DEEPENING LOW WILL MOVE TO EAST OF LAKE SUPERIOR ON MONDAY.
NORTHERLY WINDS WILL INCREASE TO GALES 35-45 KTS BY MONDAY MORNING
INTO MONDAY NIGHT. EXPECT WINDS TO DIMINISH TO 25 KTS OR LESS
TUESDAY INTO WEDNESDAY...THEN INCREASE TO 30 KTS ON THURSDAY AS COLD
AIR POURS ACROSS LAKE SUPERIOR BETWEEN HIGH PRESSURE BUILDING OVER
THE NORTHERN PLAINS AND LOW PRESSURE CROSSING THE LOWER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
DENSE FOG ADVISORY UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR
MIZ001>007-009>014-084-085.
LAKE EFFECT SNOW ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EST
TUESDAY FOR MIZ006-007-085.
LAKE EFFECT SNOW ADVISORY FROM 7 AM EST /6 AM CST/ THIS MORNING
TO 7 AM EST /6 AM CST/ TUESDAY FOR MIZ001>003-009.
LAKESHORE FLOOD ADVISORY FROM 11 AM THIS MORNING TO 6 AM EST
TUESDAY FOR MIZ001-003-005>007.
LAKE EFFECT SNOW ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
TUESDAY FOR MIZ004-005.
LAKE SUPERIOR...
GALE WARNING FROM 3 PM THIS AFTERNOON TO 4 AM EST TUESDAY FOR
LSZ251-267.
GALE WARNING FROM 10 AM THIS MORNING TO 4 AM EST TUESDAY FOR
LSZ246>250-265-266.
GALE WARNING FROM 6 AM THIS MORNING TO 2 AM EST TUESDAY FOR
LSZ242>245-263-264.
GALE WARNING FROM NOON EST /11 AM CST/ TODAY TO 9 PM EST /8 PM
CST/ THIS EVENING FOR LSZ162.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
926 PM CST TUE NOV 25 2014
.UPDATE...
ISSUED AT 926 PM CST TUE NOV 25 2014
EXPANDED THE WINTER WEATHER ADVISORY NORTH A COUPLE ROWS OF
COUNTIES TO INCLUDE AREAS FROM WILLMAR TO ST PAUL AND SOUTH. THE
NAM AND GFS CONTINUE TO ADVERTISE THE NORTHERN BATCH OF SNOW OVER
NORTH DAKOTA WEAKENING OVERNIGHT AS IT HEADS SOUTHEAST...WITH THE
SOUTH DAKOTA BATCH PUSHING INTO SOUTHWEST MINNESOTA OVERNIGHT. AN
INVERTED TROUGH IS EXPECTED TO DEVELOP WEDNESDAY...WITH THE
NORTHERN BATCH ENERGIZING AFTER SUNRISE ACROSS MOST OF EAST
CENTRAL MINNESOTA. THE 21Z SREF HAS SHIFTED NORTH TO COME INTO
LINE WITH THE NAM AND GFS...AND THE HI-RES MODELS OF
HOPWRF...HRRR...AND TO SOME DEGREE THE RAP IN BRINGING THE
BULLS EYE OF HEAVIEST SNOW FROM JUST NORTH OF MANKATO INTO THE FAR
SOUTHWESTERN TWIN CITIES SUBURBS. THIS IS THE AREA WHERE THIS
ENERGIZED BATCH OF SNOW IS EXPECTED TO LINGER FOR SOME TIME DURING
THE LATE MORNING AND EARLY AFTERNOON LEADING TO AT LEAST A FEW TO
AS MUCH AS 5 INCHES. SNOW WILL QUICKLY DISSIPATE DURING MID
AFTERNOON...WITH A SHARP CUT OFF TO SNOW AMOUNTS TO THE EAST OVER
FAR WESTERN WI.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 415 PM CST TUE NOV 25 2014
THE MAIN CONCERN IN THE SHORT TERM IS A CLIPPER SYSTEM MOVING
SOUTHEAST FROM THE DAKOTAS TO IOWA TONIGHT AND WEDNESDAY. THERE
REMAINS QUITE A BIT OF SPREAD IN THE QPF FROM THE VARIOUS
DETERMINISTIC SOLUTIONS TODAY ON HOW FAR EAST SIGNIFICANT
ACCUMULATING SNOW (3+") WILL GO ON WEDNESDAY. ALTHOUGH THE H7 LOW
ASSOCIATED WITH THE CLIPPER WILL BASICALLY PASS ACROSS SOUTHWEST
MN LATE TONIGHT...A SECOND SHORT WAVE IS PUSHING ACROSS FAR
NORTHERN MN DURING THIS SAME TIME. THE NAM AND THE GFS HAVE MUCH MORE
QPF SPREADING NORTHEAST AHEAD OF THE NORTHERN STREAM
FEATURE...WHICH IF TRUE...WOULD RESULT IN MUCH MORE SNOW ACROSS
EASTERN MN AND WEST CENTRAL WI THEN CURRENTLY FORECAST...WHICH IS
IN THE 1 TO 2 INCH RANGE. THE GEM AND ECMWF HAVE MORE SEPARATION
IN THE QPF...WITH MUCH OF THE SNOW FOCUSED FROM WEST CENTRAL
THROUGH SOUTH CENTRAL MINNESOTA LATE TONIGHT AND WEDNESDAY. ITS
INTERESTING TO NOTE THAT THE PAST FIVE RUNS OF THE ECMWF HAVE
SHOWN THE MID LEVEL LOW SINKING SLOWLY SOUTHWARD WITH TIME WHICH WOULD
KEEP THE HEAVIEST SNOW TO THE WEST AND SOUTH OF THE TWIN CITIES.
THE 15Z SREF IS BASICALLY IN LINE WITH THIS IDEA...SHOWING THE
HIGHEST PROBABILITIES (60-80 PERCENT) FOR GREATER THAN 0.25 INCHES
OF QPF IN 12 HOURS FROM WEST CENTRAL THROUGH SOUTH CENTRAL
MINNESOTA. THERE IS A LITTLE BIT OF A FINGER OF HIGHER
PROBABILITIES POINTING TOWARDS THE SOUTHWEST TWIN CITIES METRO.
HENCE...WITH CONFIDENCE HIGHEST FOR 3+ INCHES OF SNOW LATE TONIGHT
AND WEDNESDAY MORNING FROM WEST CENTRAL THROUGH SOUTH CENTRAL
MINNESOTA...A WINTER WEATHER ADVISORY WAS ISSUED FOR THESE AREAS.
WITH SOME HINT THAT THE HEAVIER SNOW COULD GET A LITTLE MORE TO
THE EAST...THE ADVISORY REACHES ACROSS MCLEOD AND SIBLEY COUNTIES.
KEPT THE ADVISORY GOING ALONG THE I-35 CORRIDOR FROM NORTHFIELD TO
ALBERT LEA DURING THE AFTERNOON WHERE SNOW WILL LINGER.
LOW TEMPERATURES TONIGHT ARE A LITTLE TRICKY WITH THE LOW CLOUDS
TRYING TO DIMINISH SOME THIS EVENING WHILE SOUTHERLY LOW LEVEL
FLOW/WAA INCREASES. WENT ON THE LOW SIDE OF GUIDANCE WITH
DEW POINTS ONLY IN THE SINGLE DIGITS AND TEENS ALONG WITH SOME SNOW
COVER. HIGHS ON WEDNESDAY ONLY IN THE TEENS ACROSS THE WEST WITH
LOWER TO MIDDLE 20S EAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 415 PM CST TUE NOV 25 2014
THE LONG TERM CONTINUES THE PUSH PULL WEATHER PATTERN WITH BRIEF
WARM UP/COOL DOWNS. THE INITIAL WAVE EXITS EARLY WEDNESDAY
NIGHT...WITH COOLER HIGH PRESSURE FOLLOWING FOR THANKSGIVING DAY.
HIGH TEMPERATURES EXPECTED TO REMAIN IN THE TEENS ONCE AGAIN.
THE NEXT WAVE MOVES IN WITH WAA DRIVING EAST ACROSS THE AREA
THANKSGIVING NIGHT AND FRIDAY. A GENERAL 2-3 INCH SNOW IS LIKELY
ALONG AND NORTHEAST OF I-94. THE WARM FRONT LIFTS NORTH ACROSS THE
CWA. DEPENDING ON SUNSHINE...TEMPERATURES COULD WARM THROUGH THE
30S AGAIN...ESPECIALLY IN THE FAR SOUTH. HOWEVER...THERE IS SOME
MODEL TIMING ISSUES...WITH THE GFS FASTER WITH THE NEXT COLD FRONT.
WILL MOVE TOWARDS A SLOWER AND WARMER SOLUTION FOR NOW...WITH SOME
SMALL CHANCE POPS ASSOCIATED WITH THIS FRONT. BETTER FORCING AND
BAROCLINIC ZONE DEVELOPS ALONG THE NORTHERN PERIPHERY OF THE AREA.
THE PRECIPITATION...IF IT DOES DEVELOP..COULD BE IN THE FORM OF
FREEZING DRIZZLE/LIGHT SNOW OR FLURRIES. THE GFS IS THE MORE ROBUST MODEL
IN THE OVERALL DEVELOPMENT ACROSS THE REGION.
ARCTIC HIGH PRESSURE DROPS SOUTH AGAIN OVER THE CWA FOR SATURDAY AND
SATURDAY NIGHT. WE SHOULD SEE CLOUDS CLEAR OUT OF THE AREA DURING
THE DAY SUNDAY...PROVIDING DRIVE HOLIDAY TRAVEL FOR THE AREA. COLD
TEMPERATURES RETURN WITH HIGHS IN THE TEENS BOTH SUNDAY AND
MONDAY...BEFORE THE NEXT UPPER TROUGH SWINGS OVER THE WESTERN CONUS
AND DRIVES WARMER AIR BACK NORTH AND EAST TOWARD THE NORTHERN
PLAINS/WESTERN GREAT LAKES FOR TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 530 PM CST TUE NOV 25 2014
CONFIDENCE IS MEDIUM TO HIGH ACROSS SOUTHWESTERN MINNESOTA...BUT
LOW TO THE NORTH AND EAST OVERNIGHT AND WEDNESDAY AS A CLIPPER
SYSTEM TRACKS SOUTHEAST INTO IOWA. LOTS OF REPORTS OF LIFR
CONDITIONS ACROSS NODAK IN MODERATE OR EVEN HEAVY SNOW. THIS BATCH
OF SNOW SHOULD WEAKEN THIS EVENING...BUT THE BATCH TO THE SOUTH
OVER SODAK WILL KEEP PROGRESSING SOUTHEASTWARD INTO SOUTHWEST MN
DURING THE NEXT SEVERAL HOURS. SHOULD SEE RWF EXPERIENCE
ACCUMULATING SNOW DURING MUCH OF THE OVERNIGHT HOURS INTO
WEDNESDAY MORNING. HOW THIS SYSTEM EVOLVES WEDNESDAY IS THE
BIGGEST CAUSE FOR UNCERTAINTY. SOME MODELS SHOW THE NORTHERN
SECTION REINVIGORATING OVER CENTRAL MN...INCLUDING STC...MSP...AND
TO A LESSER DEGREE RNH WEDNESDAY. OTHER MODELS KEEP THE NORTHERN
SECTION WEAK. EITHER SOLUTION IS POSSIBLE AT THIS POINT...AND WILL
NEED TO WATCH IT THIS EVENING.
KMSP...QUITE A BIT OF UNCERTAINTY AT THIS POINT FOR MSP WITH THE
POSSIBILITY OF LIGHT SNOW FOR A TIME WEDNESDAY MORNING...OR A MORE
TROUBLESOME POSSIBILITY OF SEVERAL INCHES OF ACCUMULATION FOR MUCH
OF THE DAY...LEADING TO SERIOUS ISSUES. KEPT THE PREVIOUS FORECAST
IN TACT FOR THE MOST PART WITH ONLY MINOR TWEAKS. WILL NEED TO
CONTINUE ASSESSING THE SITUATION THIS EVENING.
/OUTLOOK FOR KMSP/
THU...VFR. NW 4-8 KTS.
FRI...CHC MVFR AND -SN. WINDS SE 5 KTS.
SAT...CHC MVFR. WINDS NORTH 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST WEDNESDAY FOR
MNZ059-060-062-068>070-076-077-084-085-093.
WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR MNZ054-
056>058-064>067-073>075-082-083-091-092.
WI...NONE.
&&
$$
UPDATE...BORGHOFF
SHORT TERM...RAH
LONG TERM...DWE
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
ISSUED BY NATIONAL WEATHER SERVICE LA CROSSE WI
249 PM CST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 249 PM CST MON NOV 24 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A POTENT TROUGH COMING INTO CENTRAL BRITISH COLUMBIA ON TOP
OF EAST PACIFIC RIDGING...AND MORE TROUGHING COVERING MUCH OF
CENTRAL NORTH AMERICA. WITHIN THIS BROAD TROUGH...A SHORTWAVE WAS
PRESENT OVER EASTERN IOWA/NORTHERN IL...WHICH DPVA FROM IT COMBINED
WITH A BAND OF MID LEVEL FRONTOGENESIS HAS ALLOWED A BAND OF SNOW TO
PERSIST FROM WESTERN INTO SOUTHERN WI. ADDITIONAL SNOW SHOWERS HAVE
BEEN TAKING PLACE ACROSS MUCH OF MN INTO IA...MOSTLY ASSOCIATED WITH
INSTABILITY PRODUCED FROM COOL MID LEVEL TEMPS ALOFT AND RELATIVELY
WARMER TEMPS/DEWPOINTS AT THE SURFACE. RAP 700MB TEMPS SHOWED
READING IN THE -12 TO -13C RANGE...MEANWHILE SURFACE TEMPS HAVE
COOLED INTO THE TEENS AND 20S...WARMEST IN WESTERN WI. A TIGHT
PRESSURE GRADIENT IN PLACE...BETWEEN A SURFACE RIDGE OVER THE
WESTERN PLAINS AND A LOW PRESSURE TROUGH IN NORTHERN LOWER MI...HAS
PRODUCED GUSTS OF 30-40 MPH. THE STRONGEST GUSTS HAVE BEEN CONFINED
TO SOUTHWEST AND SOUTH CENTRAL MN WHERE THE DEEPEST MIXING HAS BEEN
TAKING PLACE. FARTHER TO THE WEST...A LARGE EXPANSE OF CLEARING
DOMINATES A LOT OF THE PLAINS...ASSOCIATED WITH THE SURFACE RIDGE
AND VERY DRY AIR. PRECIPITABLE WATER VALUES THERE ARE IN THE 0.1-0.2
INCH RANGE.
THE FOCUS FOR ATTENTION BEGINS TO SHIFT TO THAT POTENT TROUGH OVER
CENTRAL BRITISH COLUMBIA. GOOD MODEL CONSENSUS EXISTS FOR THE TROUGH
TO DIG DOWN INTO THE WESTERN DAKOTAS BY 00Z WEDNESDAY...ALLOWING
WEAK RIDGING TO BUILD OVER THE FORECAST AREA. ADDITIONALLY...THE
NEXT POTENT TROUGH WILL HELP PUSH THE CURRENT SHORTWAVE TROUGH AND
700MB COOL AIR SITUATED OVER THE FORECAST AREA OFF TO THE EAST.
FOR TONIGHT...ANTICIPATING SNOW SHOWERS OVER MINNESOTA TO DIMINISH
QUICKLY THIS EVENING WITH LOSS OF DAYTIME HEATING. FIGURE
SOMEWHERE AROUND 03Z THEY SHOULD HAVE ENDED...IN AGREEMENT WITH A
LOT OF HI RESOLUTION MODEL GUIDANCE. THE SNOW OVER WESTERN WI WILL
TAKE LONGER TO END BEING ASSOCIATED WITH THE MID LEVEL
FRONTOGENESIS BAND THERE...SOMEWHERE AROUND 06Z. CURRENT WINTER
WEATHER ADVISORY END TIME STILL LOOKS GOOD. REGARDING THE WIND
ADVISORY...PRESENT WINDS ARE MARGINAL TO KEEP IT GOING.
HOWEVER...SINCE CONDITIONS REMAIN BRISK FOR THE REST OF THE
AFTERNOON AND WINDS ARE STILL ON TRACK TO DIMINISH THIS
EVENING...PLAN ON LETTING THE WIND ADVISORY EXPIRE AT 6 PM. CLEARING
ACROSS THE PLAINS SHOULD MAKE ITS WAY WEST TO EAST ACROSS A LOT OF
THE FORECAST AREA...PERHAPS EVEN INTO WESTERN WI BY 12Z. THE
CLEARING COMBINED WITH A WEAKENING PRESSURE GRADIENT AND ALREADY
COOL TEMPERATURES SHOULD ALLOW READINGS TO DIP INTO THE SINGLE
DIGITS OVER WEST-CENTRAL MN. TEENS ARE LIKELY ELSEWHERE WITH MORE
CLOUDS AND WIND. IT SHOULD BE NOTED THAT MORE CLOUDS ARE LIKELY TO
COME INTO WESTERN SECTIONS OF THE FORECAST AREA BY 12Z...AHEAD OF
THE APPROACHING POTENT TROUGH.
ON TUESDAY...CLOUDS WILL MARCH THEIR WAY WEST TO EAST ACROSS THE
FORECAST AREA AGAIN AS THE POTENT TROUGH MOVES INTO THE WESTERN
DAKOTAS. ANY PRECIPITATION DOES LOOK TO REMAIN TO THE WEST PRIOR TO
00Z WEDNESDAY...THOUGH. ALTHOUGH THERE MIGHT BE MORE CLOUDS...
INCREASING SOUTHWESTERLY FLOW AHEAD OF THE AFTERNOON SHOULD HELP
GIVE TEMPERATURES A BOOST. IN FACT...925MB READINGS CLIMB FROM
AROUND -10C AT 12Z TO -4 TO -7C BY 00Z...WARMEST NEAR MANKATO AND
NEW ULM. MOST LOCATIONS SHOULD SEE HIGHS IN THE 20S...WITH 30S
POSSIBLE NEAR THE MN RIVER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 249 PM CST MON NOV 24 2014
MAIN FOCUS STARTING OFF THE PERIOD IS THE POTENT SHORTWAVE TROUGH
CURRENTLY IN CENTRAL BRITISH COLUMBIA. THERE HAS BEEN A MAJOR TREND
OVER THE PAST 2 DAYS TO DIG THIS TROUGH FARTHER SOUTHWEST...
ESPECIALLY IN THE ECMWF. THIS TREND APPEARS TO BE RELATED TO THE
CURRENT CENTRAL NORTH AMERICA TROUGH BEING MORE AMPLIFIED THAN
PREVIOUSLY PROGGED. AS A RESULT OF THIS TREND...THERE IS A CHANCE
SUGGESTED BY THE 24.12Z GFS THAT MUCH OF THE AREA COULD BE MISSED BY
THIS SYSTEM. THIS WOULD BE GOOD NEWS FOR TRAVELERS. IN THE GFS...THE
SHORTWAVE TROUGH AND ITS ASSOCIATED SURFACE LOW DIVE DOWN TO NEAR
THE KANSAS CITY AREA BY 12Z...WITH THE ISENTROPIC LIFT/MID LEVEL
FRONTOGENESIS ZONE BRUSHING THE MN RIVER VALLEY WITH SOME SNOW
BETWEEN 06-18Z WEDNESDAY. HAVE TRENDED THE FORECAST DRIER TO ACCOUNT
FOR THE MODEL TREND...BUT QPF AND POPS MAY NEED TO BE REDUCED
FURTHER. TEMPERATURES SHOULD NOT DROP MUCH TUESDAY NIGHT WITH THE
CLOUDS IN PLACE AND EVEN SOME SLIGHT WARM ADVECTION POSSIBLE. FOR
WEDNESDAY...HIGHS ARE LIKELY TO OCCUR BY NOON AS COLD ADVECTION
LOOKS TO COMMENCE IN THE WAKE OF THE TROUGH. THE AMOUNT OF ADVECTION
DEPENDS ON HOW FAR SOUTH THE TROUGH DIGS...THUS THESE READINGS ARE
SUBJECT TO CHANGE.
DRY AND COLDER CONDITIONS REMAIN PROGGED TO AFFECT THE AREA FOR
WEDNESDAY NIGHT AND THANKSGIVING...AS ARCTIC HIGH PRESSURE MOVES IN
FROM THE NORTHWEST. 925MB TEMPS TOPPING OUT IN THE -10 TO -16C RANGE
WILL ONLY ALLOW FOR HIGHS IN THE TEENS.
A PATTERN CHANGE IS IN THE OFFERING FOR THURSDAY NIGHT INTO EARLY
NEXT WEEK WITH MODELS ADVERTISING A SERIES OF TROUGHS MOVING INTO
THE WESTERN U.S.. THIS RESULTS IN A MORE ZONAL FLOW PATTERN
DOWNSTREAM TO EVENTUALLY SOUTHWESTERLY EARLY NEXT WEEK. THE SWITCH
TO ZONAL FLOW RESULTS IN A WARM ADVECTION REGIME THURSDAY NIGHT AND
FRIDAY. ON THE NOSE OF THE WARM ADVECTION...A MID-LEVEL
FRONTOGENESIS SNOWFALL BAND LOOKS TO SETUP FROM THE DAKOTAS THROUGH
MINNESOTA AND WISCONSIN. EXACT PLACEMENT AND AMOUNTS ARE YET TO BE
DETERMINED...BUT THE FOCUS RIGHT NOW GENERALLY APPEARS ALONG/NORTH
OF I-94. THE WARM FRONT LOOKS TO LIFT THROUGH MUCH OF THE FORECAST
AREA FRIDAY NIGHT. THEN FOR SATURDAY...A SHORTWAVE CROSSES THE AREA
IN THE ZONAL FLOW...SENDING A COLD FRONT THROUGH. THIS PERIOD COULD
BE TRICKY FOR HIGHS. IF THE FRONT IS SLOWER...HIGHS COULD EASILY TOP
OUT IN THE 40S. HOWEVER...AT THE CURRENT SPEED...UPPER 20S TO MID
30S SEEM MORE REASONABLE. DESPITE THE ZONAL FLOW...AN ARCTIC LOW
LEVEL INTRUSION LOOKS TO AFFECT THE AREA FOR SATURDAY NIGHT AND
SUNDAY...ACCOMPANIED BY ARCTIC HIGH PRESSURE...NOTED BY 925MB TEMPS
ABOUT 5C COLDER THAN AT 850MB. THOSE 925MB TEMPS ON SUNDAY RANGING
FROM -10 TO -15C MEANS BACK TO HIGHS IN THE TEENS. WE SHOULD BEGIN
TO DISLODGE THE COLD AIR ON MONDAY WITH THE UPPER FLOW TURNING
SOUTHWESTERLY...ALLOWING FOR A REBOUND BACK INTO THE 20S FOR HIGHS.
CONDITIONS LOOK TO REMAIN DRY FOR MONDAY WITH ARCTIC HIGH PRESSURE
IN PLACE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1137 AM CST MON NOV 24 2014
MIX OF CONDITIONS TODAY AS DEFORMATION SNOW BAND CONTINUES TO IMPACT
WESTERN WISCONSIN WITH SNOW SHOWERS AND STRONG NORTHWEST WINDS
IMPACTING MINNESOTA. MVFR AND IFR CONDITIONS PREVAIL.
POCKET OF STEEPER LAPSE RATES PRODUCING CONVECTIVE SNOW SHOWERS
ACROSS CENTRAL MINNESOTA WILL CONTINUE TO SHIFT SOUTH AND SOUTHEAST
AROUND UPPER SYSTEM WITH OTHER AREAS OF LIGHT SNOW MOVING SOUTH AS
WELL. WILL HAVE TO ACCOUNT FOR OCCASIONAL LOWER VISIBILITIES THIS
AFTERNOON YET BEFORE SYSTEM EXITS TO THE EAST...ALTHOUGH CEILINGS
RELATIVELY STABLE.
SHORT BREAK BEHIND THIS SYSTEM SO WILL ATTEMPT TO TIME CLEARING IN
FROM THE WEST...ALBEIT DELAYED A LITTLE FROM EARLIER TRENDS.
MEANWHILE ANOTHER SHORT WAVE TROUGH ENTERS THE PICTURE QUICKLY
TUESDAY SO WILL SEE INCREASE IN CLOUDS IN WESTERN MINNESOTA TOWARDS
LATTER PART OF FORECAST...WITH VFR CONDITIONS.
KMSP...
MSP BETWEEN SNOW SHOWERS TO THE WEST AND DEFORMATION SNOW
AREA AREA TO THE EAST. THESE MVFR CONDITIONS WILL GIVE WAY TO LIGHT
SNOW SPREADING IN FROM THE NORTH THIS AFTERNOON WHICH COULD CREATE
POCKETS OF IFR. BY EVENING SYSTEM SHOULD PUSH FAR ENOUGH EAST
LEAVING JUST MVFR CEILINGS WITH SLOW BREAK UP IN CLOUDS FROM WEST TO
EAST OVERNIGHT. WINDS WILL ALSO BEGIN TO DECREASE OUT OF THE
NORTHWEST AND BACK TO MORE SOUTHWEST DIRECTION ON TUESDAY...AHEAD OF
NEXT WAVE.
/OUTLOOK FOR KMSP/
TUE...VFR. WINDS W 5-10 KT BECOMING SE.
WED...MVFR/IFR CHC -SN EARLY. WINDS NW 10-15KTS.
THU...VFR. WINDS LIGHT/VARIABLE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ054>056-064-065-
073>075-082>084-091>093.
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ016-
026>028.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...SHEA
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1135 PM CST Sun Nov 23 2014
.UPDATE...
Issued at 944 PM CST SUN NOV 23 2014
Back edge of rain shield has accelerated eastward over the past hour
in line with the 00Z NAM and latest HRRR output. Will end the rain
faster from west to east. In addition, will limit any mention of snow
to the n central and northeastern counties where temperatures in the
upper 30s are advecting southeast out of central/south central IA.
Will leave in mention of minor snow accumulations for these areas.
&&
.SHORT TERM...(This Evening through Wednesday Afternoon)
Issued at 307 PM CST SUN NOV 23 2014
Rain showers will continue to fill in this afternoon and evening,
impacting the forecast area along and ahead of a southeastward-
moving cold front. Rainfall totals for this evening should be mainly
less than a half of an inch in most locations.
Main focus in the short term will be the potential for rain changing
over to snow overnight as a cold front pushes through the area and a
band of post-frontal precipitation pushes eastward over the falling
temperatures. Soundings begin to support snow in our far northwest
around 03z to 06z, but initially the surface warm layer will be too
thick for snow to make it to the surface. As the near-surface layer
cools, rain will begin to mix with and then eventually change over
to snow mainly between 06z and 12z tonight. Precipitation amounts
during this time are anywhere from trace to 0.20", but with the warm
temperatures ahead of the front and warm/wet surface conditions, it
will take a pretty aggressive snow rate to accumulate any snow. Have
painted an area of 0.5-0.75" snow across northeast MO where the
coldest post-frontal temperatures and highest snowfall rates are
expected as the band moves through, then have tapered snow amounts
to zero elsewhere. The post-frontal band is expected to exit the
region by 12z, then perhaps just a dusting of light snow could wrap
back into northeast MO during the late morning/afternoon hours.
Lows tonight should not drop far below freezing with the bulk of the
cold air waiting until after 12z to push into the region, but little
to no temperature rise is expected across northern MO on Monday as
cold air continues to filter in. Elsewhere, highs may recover a bit
into the lower 40s by mid afternoon.
The next system will be a quick clipper that dives from Alberta into
northeast Missouri on Tuesday night into Wednesday morning. Light
snow is possible across the northeastern half of the CWA with this
feature, but low moisture availability will limit potential snow
accumulations to just a few tenths of an inch.
.LONG TERM...(Wednesday Evening through Sunday)
Issued at 307 PM CST SUN NOV 23 2014
Much of the long-term (particularly into next weekend) is plagued
spatially and temporally with model discrepancies with the GFS,
ECMWF, and the GEM struggling to agree, although the 12Z ECMWF has
come into a bit of a better agreement with the 12Z GFS as compared
to the 00Z ECMWF run. Low amplitude ridging at the 500mb level
appears to dominate much of the center of the country behind an
exiting sharp trough, according to the latest GFS and ECMWF runs
whereas the GEM brings a shortwave trough racing down from Canada
into MT/ND before phasing into a larger wave dominating over
Ontario. Regardless of which solution ends up playing out, they do
all generally agree on zonal flow aloft with ripples riding through
behind the NW flow on the backside of the aforementioned exiting
trough.
Between the GFS and the ECMWF, the GFS appears to be much more
progressive aloft and at the surface as compared to the ECMWF. High
pressure sinking south behind an exiting surface low takes hold of
the forecast area on Thursday, then quickly scoots across the Ohio
Valley, leaving the door open for a frontal boundary to sweep
through behind the high, according to the GFS. The ECMWF solution is
messier and slower and diverges significantly from the GFS at the
surface by next weekend. Taking all of this into account, have kept
the forecast area dry for this forecast period given a lack of a
clear precip-generating signal, except for the GFS that brings the
front through on Saturday, but again is low confidence given the
vastly different solutions.
With respect to temperatures, they look to remain on the cooler side
of normal through the end of the week, but again, the forecast for
the temps from late Friday onward has low confidence given the
discussed model discrepancies.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday Night)
Issued at 1133 PM CST SUN NOV 23 2014
Back edge of rain shield will exit northeast and central MO by pre-
dawn hours of Monday morning. Could see a rain/snow mix or brief
change over to snow over far northeast MO but little if any accumulation.
Otherwise, main concern will be from gusty northwesterly winds. Tight
pressure gradient will gradually weaken from west to east on Monday
but boundary layer mixing could see winds ramp up higher during the
late morning and early afternoon hours. VFR cigs at all four
terminals but MVFR cigs possible Monday across northern MO. Also
can`t rule out widely scattered flurries over northern MO. Will see
winds diminish from west to east early Monday evening with clearing
from west to east.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...Laflin
LONG TERM...lg
AVIATION...MJ
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
845 PM MST TUE NOV 25 2014
.UPDATE...
THE FORECAST IS GENERALLY ON TRACK THIS EVENING...ALTHOUGH SNOW IS
TAKING A BIT LONGER TO MOVE EASTWARD TOWARD BILLINGS THAN THOUGHT.
LIGHT SNOW WILL FINALLY REACH BILLINGS AFTER MIDNIGHT WITH AN INCH
OF ACCUMULATION STILL VERY POSSIBLE BY DAYBREAK. THE HEAVIEST SNOW
IN BILLINGS PROPER WILL THEN BE WEDNESDAY MORNING WITH TOTALS NEAR
3 INCHES A DISTINCT POSSIBILITY. WE REDUCED POPS OVER SOUTHEASTERN
MT TONIGHT AND WEDNESDAY MORNING BASED ON THE SLOWER MOVEMENT EAST
TO THE SNOWFALL SUGGESTED BY RADAR TRENDS AND RECENT HRRR RUNS. WE
ONLY MADE MINOR TWEAKS TO THE REST OF THE FORECAST AS THE SNOWFALL
WEST AND SOUTH OF BILLINGS WILL CONTINUE MAKING ITS WAY NORTHEAST.
OUR WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES LOOK TO BE
WELL ON TRACK. SCHULTZ
&&
.SHORT TERM...VALID FOR WED AND THU...
CLIPPER ENERGY HAS EXITED THE AREA TO THE SOUTHEAST WITH SNOW
FOR THE MOST PART ENDING OVER THE EASTERN HALF OF THE FORECAST
AREA. COLD FRONT ASSOCIATED WITH THIS SYSTEM HAS BANKED UP AGAINST
THE WESTERN FOOTHILLS AT THIS TIME WITH NORTHERLY WINDS NOW IN
PLACE FROM LIVINGSTON TO RED LODGE. SNOW IS INCREASING ALONG THIS
FRONTAL BAND FROM SOUTHERN ROSEBUD AND SHERIDAN COUNTY WEST TO
RED LODGE...BIG TIMBER AND LIVINGSTON. DOWNSLOPE DRY SLOT HAS
DEVELOPED FROM BILLINGS AND HARDIN TO ROUNDUP AND HARLOWTON AND
THIS SHOULD PERSIST FOR A FEW MORE HOURS. ONCE TEMPERATURES START
TO COOL AT THE SURFACE AND DOWNSLOPE WINDS DECOUPLE SOME SHOULD
SEE THIS AREA FILL IN WITH SNOW. MODELS IN GOOD AGREEMENT WITH
ISENTROPIC SNOW FROM TONIGHT THROUGH WEDNESDAY OVER WESTERN AND
CENTRAL ZONES...SHIFTING NORTHEAST AS A WARM FRONT LATE WEDNESDAY
INTO THURSDAY. AS WARM ADVECTION SHALLOWS OUT THE COLD LOW LEVEL
AIR WILL SEE A TRANSITION TO MIXED PRECIPITATION WITH THE
POTENTIAL FOR SOME FREEZING RAIN MIXED IN ESPECIALLY WEDNESDAY
NIGHT INTO THURSDAY FROM BILLINGS EAST. TEMPERATURES WILL REALLY
WARM UP ON THURSDAY AS ZONAL FLOW ALOFT PRODUCES A STRONG
DOWNSLOPE GRADIENT WHICH WILL PUSH TEMPERATURES WELL INTO THE 40S
WEST AND CENTRAL...WITH ABOVE FREEZING TEMPERATURES EXPECTED OVER
EASTERN AREAS IN THE AFTERNOON. EXPECT A PERIOD OF STRONG GAP
WINDS FOR WESTERN FOOTHILLS LOCATIONS STARTING WEDNESDAY NIGHT AND
CONTINUING THROUGH FRIDAY AHEAD OF NEXT COLD FRONT...AND BUMPED
WIND SPEEDS UP TO ADVISORY CRITERIA FOR THIS. WILL HOLD OFF
ISSUING HIGHLITES UNTIL WE ARE FURTHER ALONG WITH CURRENT WINTER
HIGHLITES.
WINTER HIGHLITES...MADE SOME ADJUSTMENTS TO THE GOING HIGHLITES.
ALREADY SEEING 6 TO 10 INCHES OF SNOW IN THE BIGHORN MOUNTAINS AND
WITH SNOW EXPECTED TO CONTINUE INTO TOMORROW BUMPED THAT AREA TO A
WARNING. STARTED ADVISORY FOR CARBON...SOUTHERN BIG
HORN...SOUTHERN ROSEBUD AND SHERIDAN COUNTY EARLY TO ACCOUNT FOR
CURRENT RADAR AND ROAD CONDITION TRENDS. SNOW LOOKS TO BE SLOWER
TO SHIFT EAST TONIGHT THAN PREVIOUS FORECAST EXPECTED. IT IS
POSSIBLE THAT AREAS FROM ROUNDUP TO BILLINGS COULD BE JUST EAST OF
THE PRECIPITATION UNTIL LATE THIS EVENING WITH SNOW NOT GETTING
INTO TREASURE AND NORTHERN ROSEBUD COUNTY UNTIL SUNRISE. AS A
RESULT PUSHED BACK THE START TIME FOR TREASURE AND ROSEBUD COUNTY
UNTIL 3AM. LEFT BILLINGS...MUSSELSHELL AND NORTHERN BIG HORN
TIMING ALONE FOR NOW AS SNOW WILL BE CLOSE ENOUGH THAT ONLY A
SLIGHT DEVIATION IN CURRENT MODEL TIMING WILL BRING SNOW IN BY MID
EVENING.
IMPACTS...DOT WEBCAMS SHOWING A MIXED BAG OF SNOWY AND WET ROADS
WITH A FEW AREAS THAT ARE STILL DRY. WITH SUNSET MOST ROADWAYS
WILL QUICKLY ICE UP...ESPECIALLY BRIDGES AND OVERPASSES. THOSE
TRAVELING TONIGHT SHOULD SLOW DOWN AND BE ALERT FOR BLACK ICE.
CHAMBERS
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
MAIN THEME WITH THE EXTENDED FORECAST IS A ROLLER COASTER RIDE
WITH TEMPERATURES. MODELS SEEM TO BE IN DECENT AGREEMENT WITH THE
SYNOPTIC FEATURES BUT DIFFER QUITE A BIT WITH TIMING AND EVOLUTION
OF SYSTEMS. AFTER A SOMEWHAT MILD THANKSGIVING DAY...THE MAJORITY
OF FRIDAY LOOKS TO BE MILD AS WELL BUT ANOTHER ARCTIC FRONT WILL
BE POISED TO MOVE ACROSS THE FORECAST AREA. VARIOUS MODEL
SOLUTIONS BRING THE FRONT THROUGH DURING THE AFTERNOON OR NOT
UNTIL FRIDAY NIGHT. WE WILL KEEP FRIDAY TEMPERATURES MILD BUT THIS
MAY GET CHANGED DURING THE NEXT DAY OR TWO. BY SATURDAY...MODELS
SHOW THE FORECAST AREA ENTRENCHED IN ARCTIC AIR SO MOST LIKELY
OVERNIGHT LOWS FRIDAY NIGHT WILL NOT RISE MUCH IF ANY FOR THE DAY
SATURDAY. SNOW WILL ACCOMPANY THE FRONT FRIDAY NIGHT AND LINGER
INTO SATURDAY BUT AMOUNTS AT THIS TIME ARE UNCERTAIN.
GIVEN THE WARM DAY ON FRIDAY FOLLOWED BY SNOW WITH OVERNIGHT LOWS
IN THE TEENS...EXPECT THE POSSIBILITY OF SLICK ROADS FRIDAY NIGHT
THROUGH SATURDAY. CONDITIONS LOOK TO BE DRY FOR SUNDAY BUT THE
COLD AIR WILL REMAIN IN PLACE. LEE-SIDE TROUGHING AND DOWNSLOPE
WINDS RETURN FOR MONDAY AND DEPENDING ON SNOW COVER...TEMPERATURES
COULD WARM BACK INTO THE 30S. THIS WILL BE SHORT-LIVED AS ANOTHER
ARCTIC FRONT MOVES THROUGH MONDAY NIGHT BUT MODELS AGAIN DIFFER IN
THE TIMING. HOOLEY
&&
.AVIATION...
A BAND OF LIGHT TO MODERATE SNOW WILL REMAIN ANCHORED ALONG THE
FOOTHILLS FROM LIVINGSTON TO RED LODGE TO SHERIDAN MOST OF THE
NIGHT. THE SNOW WILL BE LOCALLY HEAVY AROUND RED LODGE. THIS WILL
CAUSE LIFR TO VLIFR CONDITIONS IN THESE LOCATIONS. MOUNTAINS WILL
BE OBSCURED IN SNOW. THE SNOW BAND WILL SHIFT EAST OVERNIGHT AND
IMPACT BILLINGS WITH IFR TO LIFR CONDITIONS. SNOW WILL BE HEAVIEST
IN BILLINGS TOWARD MORNING. THE SNOW WILL MOVE INTO MILES CITY
WEDNESDAY MORNING. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
WED THU FRI SAT SUN MON TUE
-----------------------------------------------------------
BIL 024/032 027/048 036/048 016/018 001/015 007/030 018/032
99/O 31/B 01/B 36/S 32/J 11/B 13/S
LVM 025/040 037/049 039/046 023/025 006/023 017/034 023/034
+6/O 31/N 12/W 36/S 42/J 21/B 23/S
HDN 023/032 023/047 032/048 014/016 002/018 005/028 014/034
99/O 41/B 01/B 23/S 32/J 11/B 12/S
MLS 019/027 021/043 030/044 011/013 903/012 002/024 012/026
28/S 73/O 11/B 34/S 31/B 11/B 12/S
4BQ 020/030 020/047 031/047 015/017 003/020 007/030 015/031
27/S 61/E 11/B 23/S 31/B 11/B 12/S
BHK 014/022 016/037 028/042 012/014 902/011 001/024 012/029
25/S 63/O 11/B 23/S 31/B 11/B 12/S
SHR 022/032 023/048 033/049 019/021 006/024 010/034 018/033
99/S 21/B 00/B 12/S 22/J 10/B 12/S
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL NOON MST WEDNESDAY
FOR ZONES 28-40-41-63>65.
WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 PM MST WEDNESDAY
FOR ZONES 29-34-35-38-42-57-58.
WINTER WEATHER ADVISORY IN EFFECT FROM 3 AM TO 6 PM MST
WEDNESDAY FOR ZONES 30-31.
WINTER STORM WARNING IN EFFECT UNTIL 6 PM MST WEDNESDAY FOR
ZONE 39.
WINTER STORM WARNING IN EFFECT UNTIL NOON MST WEDNESDAY FOR
ZONES 56-66>68.
WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 PM MST WEDNESDAY
FOR ZONE 99.
WINTER STORM WARNING IN EFFECT UNTIL 6 PM MST WEDNESDAY FOR
ZONE 98.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
529 PM MST TUE NOV 25 2014
.UPDATE...
WE HAVE UPGRADED THE RED LODGE AND BEARTOOTH FOOTHILLS AND EASTERN
CARBON COUNTY TO A WINTER STORM WARNING. WE/VE RECEIVED REPORTS OF
4 TO 6 INCHES OF SNOW IN THE RED LODGE AND BRIDGER AREAS AS OF 515
PM MST UNDERNEATH A BAND OF MORE INTENSE RADAR RETURNS /WHICH ALSO
STRETCHES NORTHWEST TOWARD FISHTAIL AND ABSAROKEE/. THE HRRR SEEMS
TO PICK UP ON THIS WELL AND SUPPORTS ADDITIONAL SNOWFALL OF 3 TO 6
INCHES IN THAT AREA OVERNIGHT WITH STORM TOTALS OF 6 TO 12 INCHES.
SCHULTZ
&&
.SHORT TERM...VALID FOR WED AND THU...
CLIPPER ENERGY HAS EXITED THE AREA TO THE SOUTHEAST WITH SNOW
FOR THE MOST PART ENDING OVER THE EASTERN HALF OF THE FORECAST
AREA. COLD FRONT ASSOCIATED WITH THIS SYSTEM HAS BANKED UP AGAINST
THE WESTERN FOOTHILLS AT THIS TIME WITH NORTHERLY WINDS NOW IN
PLACE FROM LIVINGSTON TO RED LODGE. SNOW IS INCREASING ALONG THIS
FRONTAL BAND FROM SOUTHERN ROSEBUD AND SHERIDAN COUNTY WEST TO
RED LODGE...BIG TIMBER AND LIVINGSTON. DOWNSLOPE DRY SLOT HAS
DEVELOPED FROM BILLINGS AND HARDIN TO ROUNDUP AND HARLOWTON AND
THIS SHOULD PERSIST FOR A FEW MORE HOURS. ONCE TEMPERATURES START
TO COOL AT THE SURFACE AND DOWNSLOPE WINDS DECOUPLE SOME SHOULD
SEE THIS AREA FILL IN WITH SNOW. MODELS IN GOOD AGREEMENT WITH
ISENTROPIC SNOW FROM TONIGHT THROUGH WEDNESDAY OVER WESTERN AND
CENTRAL ZONES...SHIFTING NORTHEAST AS A WARM FRONT LATE WEDNESDAY
INTO THURSDAY. AS WARM ADVECTION SHALLOWS OUT THE COLD LOW LEVEL
AIR WILL SEE A TRANSITION TO MIXED PRECIPITATION WITH THE
POTENTIAL FOR SOME FREEZING RAIN MIXED IN ESPECIALLY WEDNESDAY
NIGHT INTO THURSDAY FROM BILLINGS EAST. TEMPERATURES WILL REALLY
WARM UP ON THURSDAY AS ZONAL FLOW ALOFT PRODUCES A STRONG
DOWNSLOPE GRADIENT WHICH WILL PUSH TEMPERATURES WELL INTO THE 40S
WEST AND CENTRAL...WITH ABOVE FREEZING TEMPERATURES EXPECTED OVER
EASTERN AREAS IN THE AFTERNOON. EXPECT A PERIOD OF STRONG GAP
WINDS FOR WESTERN FOOTHILLS LOCATIONS STARTING WEDNESDAY NIGHT AND
CONTINUING THROUGH FRIDAY AHEAD OF NEXT COLD FRONT...AND BUMPED
WIND SPEEDS UP TO ADVISORY CRITERIA FOR THIS. WILL HOLD OFF
ISSUING HIGHLITES UNTIL WE ARE FURTHER ALONG WITH CURRENT WINTER
HIGHLITES.
WINTER HIGHLITES...MADE SOME ADJUSTMENTS TO THE GOING HIGHLITES.
ALREADY SEEING 6 TO 10 INCHES OF SNOW IN THE BIGHORN MOUNTAINS AND
WITH SNOW EXPECTED TO CONTINUE INTO TOMORROW BUMPED THAT AREA TO A
WARNING. STARTED ADVISORY FOR CARBON...SOUTHERN BIG
HORN...SOUTHERN ROSEBUD AND SHERIDAN COUNTY EARLY TO ACCOUNT FOR
CURRENT RADAR AND ROAD CONDITION TRENDS. SNOW LOOKS TO BE SLOWER
TO SHIFT EAST TONIGHT THAN PREVIOUS FORECAST EXPECTED. IT IS
POSSIBLE THAT AREAS FROM ROUNDUP TO BILLINGS COULD BE JUST EAST OF
THE PRECIPITATION UNTIL LATE THIS EVENING WITH SNOW NOT GETTING
INTO TREASURE AND NORTHERN ROSEBUD COUNTY UNTIL SUNRISE. AS A
RESULT PUSHED BACK THE START TIME FOR TREASURE AND ROSEBUD COUNTY
UNTIL 3AM. LEFT BILLINGS...MUSSELSHELL AND NORTHERN BIG HORN
TIMING ALONE FOR NOW AS SNOW WILL BE CLOSE ENOUGH THAT ONLY A
SLIGHT DEVIATION IN CURRENT MODEL TIMING WILL BRING SNOW IN BY MID
EVENING.
IMPACTS...DOT WEBCAMS SHOWING A MIXED BAG OF SNOWY AND WET ROADS
WITH A FEW AREAS THAT ARE STILL DRY. WITH SUNSET MOST ROADWAYS
WILL QUICKLY ICE UP...ESPECIALLY BRIDGES AND OVERPASSES. THOSE
TRAVELING TONIGHT SHOULD SLOW DOWN AND BE ALERT FOR BLACK ICE.
CHAMBERS
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
MAIN THEME WITH THE EXTENDED FORECAST IS A ROLLER COASTER RIDE
WITH TEMPERATURES. MODELS SEEM TO BE IN DECENT AGREEMENT WITH THE
SYNOPTIC FEATURES BUT DIFFER QUITE A BIT WITH TIMING AND EVOLUTION
OF SYSTEMS. AFTER A SOMEWHAT MILD THANKSGIVING DAY...THE MAJORITY
OF FRIDAY LOOKS TO BE MILD AS WELL BUT ANOTHER ARCTIC FRONT WILL
BE POISED TO MOVE ACROSS THE FORECAST AREA. VARIOUS MODEL
SOLUTIONS BRING THE FRONT THROUGH DURING THE AFTERNOON OR NOT
UNTIL FRIDAY NIGHT. WE WILL KEEP FRIDAY TEMPERATURES MILD BUT THIS
MAY GET CHANGED DURING THE NEXT DAY OR TWO. BY SATURDAY...MODELS
SHOW THE FORECAST AREA ENTRENCHED IN ARCTIC AIR SO MOST LIKELY
OVERNIGHT LOWS FRIDAY NIGHT WILL NOT RISE MUCH IF ANY FOR THE DAY
SATURDAY. SNOW WILL ACCOMPANY THE FRONT FRIDAY NIGHT AND LINGER
INTO SATURDAY BUT AMOUNTS AT THIS TIME ARE UNCERTAIN.
GIVEN THE WARM DAY ON FRIDAY FOLLOWED BY SNOW WITH OVERNIGHT LOWS
IN THE TEENS...EXPECT THE POSSIBILITY OF SLICK ROADS FRIDAY NIGHT
THROUGH SATURDAY. CONDITIONS LOOK TO BE DRY FOR SUNDAY BUT THE
COLD AIR WILL REMAIN IN PLACE. LEE-SIDE TROUGHING AND DOWNSLOPE
WINDS RETURN FOR MONDAY AND DEPENDING ON SNOW COVER...TEMPERATURES
COULD WARM BACK INTO THE 30S. THIS WILL BE SHORT-LIVED AS ANOTHER
ARCTIC FRONT MOVES THROUGH MONDAY NIGHT BUT MODELS AGAIN DIFFER IN
THE TIMING. HOOLEY
&&
.AVIATION...
SNOW WILL DEVELOP WEST OF BILLINGS THIS AFTERNOON AND SLOWLY
SPREAD EAST INTO THE BILLINGS AREA BY MID TO LATE EVENING. VFR
CONDITIONS WILL GIVE WAY TO MVFR TO IFR CONDITIONS WITH OCCASIONAL
LIFR CONDITIONS AS CEILINGS AND VISIBILITIES LOWER. THE MAJORITY
OF THE SNOW WILL BE ALONG AND WEST OF A ROUNDUP-KBIL-KSHR LINE
THROUGH 06Z WITH THE SNOW EXTENDING EAST OF THIS LINE TOWARD KMLS
AND KBHK AFTER 06Z. HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
WED THU FRI SAT SUN MON TUE
-----------------------------------------------------------
BIL 024/032 027/048 036/048 016/018 001/015 007/030 018/032
99/O 31/B 01/B 36/S 32/J 11/B 13/S
LVM 025/040 037/049 039/046 023/025 006/023 017/034 023/034
96/O 31/N 12/W 36/S 42/J 21/B 23/S
HDN 023/032 023/047 032/048 014/016 002/018 005/028 014/034
99/O 41/B 01/B 23/S 32/J 11/B 12/S
MLS 019/027 021/043 030/044 011/013 903/012 002/024 012/026
38/S 73/O 11/B 34/S 31/B 11/B 12/S
4BQ 020/030 020/047 031/047 015/017 003/020 007/030 015/031
47/S 61/E 11/B 23/S 31/B 11/B 12/S
BHK 014/022 016/037 028/042 012/014 902/011 001/024 012/029
45/S 63/O 11/B 23/S 31/B 11/B 12/S
SHR 022/032 023/048 033/049 019/021 006/024 010/034 018/033
99/S 21/B 00/B 12/S 22/J 10/B 12/S
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL NOON MST WEDNESDAY
FOR ZONES 28-40-41-63>65.
WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 PM MST WEDNESDAY
FOR ZONES 29-34-35-38-42-57-58.
WINTER WEATHER ADVISORY IN EFFECT FROM 3 AM TO 6 PM MST
WEDNESDAY FOR ZONES 30-31.
WINTER STORM WARNING IN EFFECT UNTIL 6 PM MST WEDNESDAY FOR
ZONE 39.
WINTER STORM WARNING IN EFFECT UNTIL NOON MST WEDNESDAY FOR
ZONES 56-66>68.
WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 PM MST WEDNESDAY
FOR ZONE 99.
WINTER STORM WARNING IN EFFECT UNTIL 6 PM MST WEDNESDAY FOR
ZONE 98.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
524 PM CST TUE NOV 25 2014
.SYNOPSIS...
ISSUED AT 258 PM CST TUE NOV 25 2014
H5 ANALYSIS FROM THIS MORNING HAS CLOSED LOW OVER
NORTHERN PORTIONS OF HUDSON BAY WITH A LONGWAVE TROUGH EXTENDING
SOUTH INTO FAR SOUTHERN TEXAS. EAST OF THE TROUGH...A 70 TO 110KT
JET STREAK EXTENDED FROM BROWNSVILLE TX...NE INTO THE MID
ATLANTIC...NEW ENGLAND AND THE CANADIAN MARITIMES. WEST OF THE
TROUGH...50 TO 100 METER HT RISES WERE NOTED ACROSS THE FOUR CORNERS
THIS MORNING. OVER WESTERN CANADA...A NICE SHORTWAVE WAS PRESENT
ACROSS SRN ALBERTA AND SRN SASKATCHEWAN...WHILE AT THE SURFACE...LOW
PRESSURE WAS PRESENT OVER FAR NORTHEASTERN MONTANA. A SURFACE TROUGH
EXTENDED SWD INTO EASTERN COLORADO FROM THE SFC LOW. A WARM FRONT
EXTENDED EAST INTO SERN ND WITH AN ARCTIC COLD FRONT EXTENDING NW OF
THE SURFACE LOW INTO SOUTHERN PORTIONS OF ALBERTA. ABUNDANT MID AND
HIGH LEVEL MOISTURE CONTINUES TO STREAM INTO THE NWRN CONUS PER WV
IMAGERY...AND THIS HAS LED TO OVERCAST SKIES ACROSS WESTERN AND
NORTH CENTRAL NEBRASKA TODAY. AS OF 2 PM CST...TEMPERATURES RANGED
FROM 40 AT THEDFORD TO 47 AT IMPERIAL.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 258 PM CST TUE NOV 25 2014
THE ALBERTA CLIPPER CONTINUES TO MOVE ACROSS THE AREA TONIGHT. THE
INITIAL TROUGH HAS SPARKED A FEW ISOLATED FLURRIES/SPRINKLES ACROSS
NW NEBRASKA. RADAR RETURNS SUGGEST MORE ACROSS MUCH OF WESTERN
NEBRASKA...HOWEVER A 20 PLUS DEGREE T/TD SPREAD IN ASSOCIATION WITH
A DRY LOWER LEVEL HAS RESULTED IN LITTLE REACHING THE GROUND. TOP
DOWN SATURATION WILL TAKE PLACE TONIGHT...AS SFC TEMPS COOL...WHICH
SHOULD RESULT IN MORE PRECIP REACHING THE GROUND. HOWEVER THE FIRST
WAVE WILL BE PUSHING ACROSS N CENTRAL...WITH A SECOND WAVE ACROSS
THE PANHANDLE AND FAR WESTERN NEBRASKA. EXPECT SNOW TO BE THE
PRIMARY P TYPE AS TEMPS FALL INTO THE 30S THEN 20S AND 850MB TEMPS
BELOW ZERO. COULD BRIEFLY SEE A MIX AS SFC TEMPS START IN THE LOWER
40S. ANOTHER CONCERN WILL BE THE INCREASE OF NW WINDS BEHIND THE
MAIN COLD FRONT. LOCAL GUSTS AT TIMES TO 30 TO 40 MPH.
LINGERING LIGHT SNOW CHANCES ACROSS THE EASTERN PANHANDLE IN THE
MORNING...THEN DIMINISH FROM SOUTH TO NORTH AS DRY AIR GETS DRAW IN
FROM THE WEST. CAA WILL HOLD TEMPS DOWN WITH HIGHS ONLY IN THE
MID/UPPER 20S ACROSS NORTH CENTRAL...WHILE LOWER 30S ACROSS THE NW
AND UPPER 30S TO AROUND 40 IN THE SW. WINDS WILL BE STRONGEST IN THE
MORNING THEN DECREASING AS THE DAY GOES ON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 258 PM CST TUE NOV 25 2014
MID RANGE...WEDNESDAY NIGHT THROUGH FRIDAY...THE MAIN
FORECASTING CHALLENGES IN THE MID RANGE ARE FZDZ/LIGHT PCPN CHANCES
WEDNESDAY NIGHT...AND THEN TEMPERATURES. FOR WEDNESDAY NIGHT...A
WARM FRONT WILL LIFT FROM THE PANHANDLE INTO CENTRAL PORTIONS OF THE
FORECAST AREA. WAS INITIALLY CONCERNED ABOUT A FREEZING DRIZZLE
THREAT AS WARMER AIR ALOFT LIFTS OVER AN ARCTIC AIR MASS IN PLACE
FROM WEDNESDAY. ALSO...MODEL LAYER RH FROM H850 TO H900 IS DECENT
ACROSS NORTH CENTRAL NEBRASKA OVERNIGHT WEDS NIGHT. LOOKING AT CROSS
SECTIONS AND BUFKIT SOUNDINGS ACROSS NORTHERN NEBRASKA...THE THERMAL
PROFILE IS SOMEWHAT FAVORABLE FOR FREEZING PCPN THURSDAY
MORNING...HOWEVER...RH/S IN THE H850 TO H900 LAYER NEVER SATURATE
DURING THE PERIOD. IN ADDITION...GFS AND NAM BUFKIT SOUNDINGS DO NOT
INDICATE ANY FAVORABLE LIFT IN THIS MOIST LAYER. WITH THIS IN
MIND...WILL HOLD OFF ON ANY MENTION OF PCPN OR FZDZ WEDS NIGHT
ACROSS NORTH CENTRAL PORTIONS OF THE FORECAST AREA. WILL ADVISE THE
ONCOMING SHIFT TO WATCH THIS HOWEVER AS TRAVEL IMPACTS ARE POSSIBLE
THANKSGIVING MORNING. THROUGH MIDDAY THURSDAY...THE COLD FRONT WILL
PUSH INTO EASTERN SOUTH DAKOTA. SRLY WINDS WILL INCREASE WEST OF THE
EXITING WARM FRONT WITH A NICE WARMUP ON TAP ACROSS THE WESTERN HALF
OF THE FORECAST AREA. FURTHER EAST...LATER TIMING OF THE WARM FRONT
WILL HOLD HIGHS BACK IN THE UPPER 30S AND 40S. WEST OF HIGHWAY 83
AND SOUTH OF THE INTERSTATE...HIGHS WILL REACH THE 50S...WITH NEAR
60 POSSIBLE AROUND IMPERIAL. WITH LIGHT WESTERLY WINDS FORECAST
THURSDAY NIGHT...DECIDED TO UNDERCUT GUIDANCE A TAD BASED ON THE
LIGHT WINDS AND DRY BOUNDARY LAYER. THIS LED TO LOWS IN THE 20S WITH
LOWS AROUND 20 IN THE PLATTE VALLEY. ON FRIDAY...TEMPERATURES WILL
WARM TO THE MID 50S IN THE NORTHEAST AND MAY APPROACH 70 IN THE FAR
SOUTHWEST. TEMPS WERE TRENDED UP SLIGHTLY FROM THE INHERITED
FORECAST BASED ON HIGHER H85 TEMPS IN THIS MORNINGS GFS AND NAM
RUNS.
LONG RANGE...FRIDAY NIGHT THROUGH TUESDAY...TEMPERATURES ARE THE
MAIN FORECAST CHALLENGE IN THE LONG RANGE PERIODS...AS THE TIMING OF
AN ARCTIC FRONT FRIDAY NIGHT/SATURDAY IS STILL IN DOUBT. LOOKING AT
THE LATEST GFS AND ECMWF RUNS...BOTH MODELS HAVE THE LEADING EDGE OF
THE ARCTIC AIR ACROSS NORTHERN NEBRASKA BY 00Z SATURDAY. THIS MODEL
TREND IS IN CONTRAST WITH THE PREVIOUS RUNS OF THESE RESPECTIVE
MODELS...AS THE GFS WAS ABOUT 12 HRS FASTER WITH THE FRONT COMPARED
TO THE ECMWF. THE MAIN RUN TO RUN DIFFERENCE WITH THE GFS BETWEEN THIS
MORNINGS AND LAST NIGHTS RUN IS THE NEW GFS DROPS ARCTIC AIR INTO
THE NORTHERN CWA SATURDAY MORNING...LIFTING IT NORTH IN THE
AFTERNOON...WHICH IS HARD TO BELIEVE GIVEN THIS TIME OF YEAR. SO THIS
LEADS TO CONTINUED DOUBTS ON WHERE THE FRONT WILL BE LOCATED BY PEAK
HEATING SATURDAY. WITH THIS IN MIND...DIDN`T MAKE ANY LARGE SCALE
CHANGES TO THE TEMP FCST ON SATURDAY. ATTM PROPOSED FCST HAS HIGHS
RANGING FROM THE LOWER 40S IN THE FAR NORTH TO THE LOWER 60S IN THE
SOUTH. THE ARCTIC FRONT WILL PUSH THROUGH THE FORECAST SATURDAY
NIGHT WITH MUCH COLDER TEMPS ARRIVING FOR SUNDAY AND MONDAY.
ATTM...THE FRONTAL PASSAGE SHOULD BE A DRY ONE AS THE MID LEVEL
FRONT AND ASSOCIATED LIFT WILL REMAIN OVER SOUTH DAKOTA SATURDAY
NIGHT. HIGHS SUNDAY WILL BE IN THE 20S...WITH 30S FOR MONDAY.
READINGS WILL REBOUND BACK INTO THE 40S AND 50S TUESDAY AS RIDGING
DEVELOPS EAST OF A WEST CONUS TROUGH.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 524 PM CST TUE NOV 25 2014
INDICATIONS ON RADAR...THE NAM...HRRR AND RAP MODELS SUGGEST THE
BEST CHANCE OF MVFR/IFR CIGS/VSBY IN SNOW WOULD OCCUR ACROSS WRN
NEB TONIGHT AS AN AREA OF SNOW SPREADS SOUTH-SOUTHEAST THROUGH THE
PANHANDLE AND SWRN NEB. OTHERWISE MVFR CIGS ARE EXPECTED ALONG AND
NORTH OF NEBRASKA HIGHWAY 2 THROUGH 15Z-17Z WITH VFR DEVELOPING
ALL AREAS THEREAFTER.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...MASEK
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1138 AM CST MON NOV 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 529 AM CST MON NOV 24 2014
...NW WINDS GUST 35-40 MPH WITH ISOLATED G45 WITH DIMINISHING
CLOUDS IN MOSTLY COLDER THAN NORMAL TEMPS...
ALOFT: THE NEWLY REESTABLISHED LONGWAVE TROF AXIS WAS SHIFTING E
OF THE FCST AREA. BACK TO NW FLOW THRU TONIGHT. THE NEXT SHORTWAVE
TROF TO AFFECT THE FCST AREA WAS OVER BRITISH COLUMBIA. THIS TROF
WILL PASS THRU HERE TONIGHT WITH ONLY AN INCREASE IN HIGH CLOUDS.
SURFACE: THE FCST AREA WAS IN THE COLD SECTOR OF DEEP LOW PRES
OVER THE GREAT LAKES THIS MORNING. WE WILL REMAIN IN THE COLD
SECTOR THRU TONIGHT. WRN USA HIGH PRES WILL GRADUALLY BUILD IN
WITH CYCLONIC BOUNDARY LAYER FLOW BECOMING ANTICYCLONIC. ITS RIDGE
AXIS WILL PASS THRU AFTER MIDNIGHT. A CLIPPER WILL FORM OVER WRN
CANADA TONIGHT AND AN ASSOCIATED WARM FRONT WILL DEVELOP SOUTHWARD
INTO THE REGION.
529 AM: LOTS OF WRAP AROUND CLOUDS IN CYCLONIC NW FLOW...N AND E
OF THE TRI-CITIES. STILL CANT RULE OUT A STRAY FLURRY ALTHOUGH
HAVE NOT SEEN ANY IN REGIONAL OBS RECENTLY.
BBW MEASURED A G39 KTS AT 421 AM. THAT IS INDICATIVE OF WHAT OUR
MAX WIND POTENTIAL IS TODAY ONCE CONVECTIVE MIXING COMMENCES.
TODAY: CONTINUED WINDY. NW WINDS WILL GUST 30-35 KTS IN DOWNWARD
TRANSFER AS THE BOUNDARY LAYER BECOMES UNSTABLE. POTENTIAL PEAK
GUSTS AS HIGH AS 40 KTS PER BUFKIT MIXING ALGORITHM. USED GFS
WITH ITS DEEPER MIXING.
THE RAP/NAM/GFS AGREE THE WRN FRINGE OF THE WRAP-AROUND CLOUDS
WILL GRADUALLY SHIFT E OF THE FCST AREA LEAVING SKIES SUNNY.
SIMULATED IR IMAGERY FROM THE 4 KM NAM NEST SUGGESTS SOME PATCHES
OF CIRROSTRATUS WILL BEGIN MOVING IN FROM THE NW LATE AND THIS
IS REASONABLE BASED ON CURRENT SATELLITE...WITH THE NRN ROCKIES
SHORTWAVE TROF DIVING TO OUR W.
INTERNAL VERIFICATION SHOWS WE HAVE BEEN RUNNING TOO COOL ON HIGH
TEMPS RECENTLY. SO USED 06Z RAP TO NUDGE TEMPS UPWARD SLIGHTLY.
HIGHS WILL STILL BE 5-10F COLDER THAN NORMAL FOR MOST OF THE FCST
AREA.
TONIGHT: WINDS DROP OFF EARLY EVENING WITH DECOUPLING. PATCHES OF
CIRROSTRATUS CONT TO DRIFT THRU BUT SHOULD BE NO WORSE THAN
P/CLOUDY.
USED THE WEIGHTED CONSENSUS OF THE 3 BEST-VERIFYING TEMP GUIDES
FOR LOWS...WHICH FAVORED THE COLDER MOS TEMPS. JUST SLIGHTLY
COLDER THAN NORMAL.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 407 AM CST MON NOV 24 2014
THE BIG HOLIDAY WEEKEND IS FAST APPROACHING AND NO TRAVEL
PROBLEMS ARE EXPECTED ACROSS NEBRASKA AND KANSAS. ALWAYS REMEMBER
YOU CAN CHECK WWW.WEATHER.GOV FOR THE LATEST WEATHER CONDITIONS
AND FORECAST FOR ANYWHERE IN THE COUNTRY WHERE YOU MIGHT BE
TRAVELING TO THIS HOLIDAY WEEKEND.
THE BIGGEST CONCERN FOR OUR AREA DURING THE HOLIDAY WEEKEND WILL
CENTER AROUND SEVERAL BIG TEMPERATURE SWINGS.
TUESDAY...THIS SHOULD BE A WARMER DAY WITH LIGHTER WINDS. THE
STRONG NORTHWEST WIND OF SUNDAY AND MONDAY WILL GIVE WAY TO A MORE
GENTLE SOUTHWESTERLY BREEZE THAT WILL HELP TO WARM HIGHS INTO THE
MID AND UPPER 40S ACROSS MOST NEBRASKA ZONES TO THE LOWER 50S
ACROSS PORTIONS OF NORTHERN KANSAS. THERE ARE SOME MODEL
DIFFERENCES WITH THE 00Z GFS TRYING TO BRING THE NEXT COLD FRONT
INTO NEBRASKA ZONES BY TUESDAY AFTERNOON ALONG WITH SOME SPRINKLES
AND SLIGHTLY COOLER AIR. HOWEVER...THE 00Z NAM AND 00Z GFS ARE
BOTH SLOWER WITH THE COLD FRONT AND ARE DRY. THIS FORECAST LEANS
TOWARDS THE ECMWF/NAM SOLUTION.
TUESDAY NIGHT INTO WEDNESDAY...COOLER AIR WILL FILTER INTO OUR
REGION BEHIND A COLD FRONT. WE CAN NOT RULE OUT A FLURRY OR
TWO...BUT GIVEN MOST FORECAST MODELS ARE COMPLETELY DRY...WE WILL
KEEP THE FORECAST DRY AND WITHHOLD ANY FLURRIES FOR NOW. FORECAST
MODELS ARE NOT AS COLD WITH THIS AIRMASS AS THEY WERE SEVERAL DAYS
AGO AND EXPECT HIGHS ON WEDNESDAY SHOULD STILL REACH THE UPPER 30S
ACROSS NORTHEASTERN ZONES TO THE MID 40S OVER NORTH CENTRAL
KANSAS.
THANKSGIVING...UNFORTUNATELY THE HOLIDAY ITSELF APPEARS TO THE BE
COLDEST DAY OF THE WEEKEND AS THE COOLER AIR THAT SETTLES IN ON
WEDNESDAY MAY HANG AROUND THROUGH THANKSGIVING DAY.
HOWEVER...FORECAST MODELS HAVE BEEN TRENDING WARMER AND SO WOULD
NOT BE SURPRISED IF OUR FORECAST HIGHS ON THANKSGIVING DAY
EVENTUALLY GET RAISED SOME. FOR NOW WILL CONTINUE TO GO WITH THE
OVERALL SUPERBLEND OF MODELS...WHICH RESULTS IN HIGHS IN THE MID
30S IN THE TRI-CITIES...TO THE LOWER AND MID 40S OVER NORTHERN
KANSAS.
FRIDAY THROUGH SUNDAY...THE OVERALL UPPER FLOW BECOMES MORE ZONAL
WITH THE REAL COLD AIR BOXED UP IN CANADA. THIS WILL ALSO KEEP THE
STORM TRACK WELL TO OUR NORTH RESULTING IN CONTINUED DRY
CONDITIONS. THERE IS GOOD CONFIDENCE IN FRIDAY BEING A VERY NICE
DAY WITH HIGHS LIKELY AROUND 50 IN THE TRI-CITIES TO THE MID AND
UPPER 50S OVER NORTH CENTRAL KANSAS WITH JUST A LIGHT SOUTHWEST
WIND. SATURDAY IS MUCH MORE UNCERTAIN WITH A COLD FRONT ON OUR
DOOR STEP. THE LATEST 00Z ECMWF IS SLOWER WITH THE COLD FRONT AND
INDICATES THAT HIGHS ON SATURDAY MAY BE EVEN WARMER THAN ON FRIDAY
POSSIBLY REACHING INTO THE 60S...BUT THE 00Z GFS IS MUCH QUICKER
WITH THE COLD FRONT AND WOULD HAVE TEMPERATURES FALLING THROUGH
THE 30S SATURDAY AFTERNOON. OUR OFFICIAL FORECAST IS CURRENTLY
SOMEWHERE IN THE MIDDLE WITH A HIGH DEGREE OF UNCERTAINTY AT THIS
TIME. CONFIDENCE REALLY DOES NOT IMPROVE MUCH ON SUNDAY AS THERE
IS UNCERTAINTY WITH REGARD TO HOW COLD THE NEXT AIR MASS WILL BE.
THE 00Z GFS AND 00Z ECMWF HAVE BOTH TRENDED DOWNWARD AND WOULD
RESULT IN HIGHS ONLY IN THE 20S ON SUNDAY WHILE OUR FORECAST STILL
IS INCORPORATING RECENT RUNS THAT WERE WARMER AND IS CALLING FOR
HIGHS IN THE 30S AND 40S. BASICALLY...EXPECT FORECAST CHANGES IN
THE COMING DAYS AS THE UNCERTAINTY ISSUES GET IRONED OUT.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1125 AM CST MON NOV 24 2014
GUSTY NORTHWEST WILL BE THE MAIN CONCERN FOR THE TAF PERIOD
THROUGH THE AFTERNOON HOURS. NORTHWEST WINDS OF 20 TO 25KTS AND
GUSTS OF 30KTS ARE FORECAST UNTIL THE GRADIENT RELAXES THIS
EVENING. CLOUD COVER IS EXPECTED TO THICKEN TOWARD TUESDAY MORNING
AND HAVE KEPT CIGS AT VFR.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
529 AM CST MON NOV 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 529 AM CST MON NOV 24 2014
...NW WINDS GUST 35-40 MPH WITH ISOLATED G45 WITH DIMINISHING
CLOUDS IN MOSTLY COLDER THAN NORMAL TEMPS...
ALOFT: THE NEWLY REESTABLISHED LONGWAVE TROF AXIS WAS SHIFTING E
OF THE FCST AREA. BACK TO NW FLOW THRU TONIGHT. THE NEXT SHORTWAVE
TROF TO AFFECT THE FCST AREA WAS OVER BRITISH COLUMBIA. THIS TROF
WILL PASS THRU HERE TONIGHT WITH ONLY AN INCREASE IN HIGH CLOUDS.
SURFACE: THE FCST AREA WAS IN THE COLD SECTOR OF DEEP LOW PRES
OVER THE GREAT LAKES THIS MORNING. WE WILL REMAIN IN THE COLD
SECTOR THRU TONIGHT. WRN USA HIGH PRES WILL GRADUALLY BUILD IN
WITH CYCLONIC BOUNDARY LAYER FLOW BECOMING ANTICYCLONIC. ITS RIDGE
AXIS WILL PASS THRU AFTER MIDNIGHT. A CLIPPER WILL FORM OVER WRN
CANADA TONIGHT AND AN ASSOCIATED WARM FRONT WILL DEVELOP SOUTHWARD
INTO THE REGION.
529 AM: LOTS OF WRAP AROUND CLOUDS IN CYCLONIC NW FLOW...N AND E
OF THE TRI-CITIES. STILL CANT RULE OUT A STRAY FLURRY ALTHOUGH
HAVE NOT SEEN ANY IN REGIONAL OBS RECENTLY.
BBW MEASURED A G39 KTS AT 421 AM. THAT IS INDICATIVE OF WHAT OUR
MAX WIND POTENTIAL IS TODAY ONCE CONVECTIVE MIXING COMMENCES.
TODAY: CONTINUED WINDY. NW WINDS WILL GUST 30-35 KTS IN DOWNWARD
TRANSFER AS THE BOUNDARY LAYER BECOMES UNSTABLE. POTENTIAL PEAK
GUSTS AS HIGH AS 40 KTS PER BUFKIT MIXING ALGORITHM. USED GFS
WITH ITS DEEPER MIXING.
THE RAP/NAM/GFS AGREE THE WRN FRINGE OF THE WRAP-AROUND CLOUDS
WILL GRADUALLY SHIFT E OF THE FCST AREA LEAVING SKIES SUNNY.
SIMULATED IR IMAGERY FROM THE 4 KM NAM NEST SUGGESTS SOME PATCHES
OF CIRROSTRATUS WILL BEGIN MOVING IN FROM THE NW LATE AND THIS
IS REASONABLE BASED ON CURRENT SATELLITE...WITH THE NRN ROCKIES
SHORTWAVE TROF DIVING TO OUR W.
INTERNAL VERIFICATION SHOWS WE HAVE BEEN RUNNING TOO COOL ON HIGH
TEMPS RECENTLY. SO USED 06Z RAP TO NUDGE TEMPS UPWARD SLIGHTLY.
HIGHS WILL STILL BE 5-10F COLDER THAN NORMAL FOR MOST OF THE FCST
AREA.
TONIGHT: WINDS DROP OFF EARLY EVENING WITH DECOUPLING. PATCHES OF
CIRROSTRATUS CONT TO DRIFT THRU BUT SHOULD BE NO WORSE THAN
P/CLOUDY.
USED THE WEIGHTED CONSENSUS OF THE 3 BEST-VERIFYING TEMP GUIDES
FOR LOWS...WHICH FAVORED THE COLDER MOS TEMPS. JUST SLIGHTLY
COLDER THAN NORMAL.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 407 AM CST MON NOV 24 2014
THE BIG HOLIDAY WEEKEND IS FAST APPROACHING AND NO TRAVEL
PROBLEMS ARE EXPECTED ACROSS NEBRASKA AND KANSAS. ALWAYS REMEMBER
YOU CAN CHECK WWW.WEATHER.GOV FOR THE LATEST WEATHER CONDITIONS
AND FORECAST FOR ANYWHERE IN THE COUNTRY WHERE YOU MIGHT BE
TRAVELING TO THIS HOLIDAY WEEKEND.
THE BIGGEST CONCERN FOR OUR AREA DURING THE HOLIDAY WEEKEND WILL
CENTER AROUND SEVERAL BIG TEMPERATURE SWINGS.
TUESDAY...THIS SHOULD BE A WARMER DAY WITH LIGHTER WINDS. THE
STRONG NORTHWEST WIND OF SUNDAY AND MONDAY WILL GIVE WAY TO A MORE
GENTLE SOUTHWESTERLY BREEZE THAT WILL HELP TO WARM HIGHS INTO THE
MID AND UPPER 40S ACROSS MOST NEBRASKA ZONES TO THE LOWER 50S
ACROSS PORTIONS OF NORTHERN KANSAS. THERE ARE SOME MODEL
DIFFERENCES WITH THE 00Z GFS TRYING TO BRING THE NEXT COLD FRONT
INTO NEBRASKA ZONES BY TUESDAY AFTERNOON ALONG WITH SOME SPRINKLES
AND SLIGHTLY COOLER AIR. HOWEVER...THE 00Z NAM AND 00Z GFS ARE
BOTH SLOWER WITH THE COLD FRONT AND ARE DRY. THIS FORECAST LEANS
TOWARDS THE ECMWF/NAM SOLUTION.
TUESDAY NIGHT INTO WEDNESDAY...COOLER AIR WILL FILTER INTO OUR
REGION BEHIND A COLD FRONT. WE CAN NOT RULE OUT A FLURRY OR
TWO...BUT GIVEN MOST FORECAST MODELS ARE COMPLETELY DRY...WE WILL
KEEP THE FORECAST DRY AND WITHHOLD ANY FLURRIES FOR NOW. FORECAST
MODELS ARE NOT AS COLD WITH THIS AIRMASS AS THEY WERE SEVERAL DAYS
AGO AND EXPECT HIGHS ON WEDNESDAY SHOULD STILL REACH THE UPPER 30S
ACROSS NORTHEASTERN ZONES TO THE MID 40S OVER NORTH CENTRAL
KANSAS.
THANKSGIVING...UNFORTUNATELY THE HOLIDAY ITSELF APPEARS TO THE BE
COLDEST DAY OF THE WEEKEND AS THE COOLER AIR THAT SETTLES IN ON
WEDNESDAY MAY HANG AROUND THROUGH THANKSGIVING DAY.
HOWEVER...FORECAST MODELS HAVE BEEN TRENDING WARMER AND SO WOULD
NOT BE SURPRISED IF OUR FORECAST HIGHS ON THANKSGIVING DAY
EVENTUALLY GET RAISED SOME. FOR NOW WILL CONTINUE TO GO WITH THE
OVERALL SUPERBLEND OF MODELS...WHICH RESULTS IN HIGHS IN THE MID
30S IN THE TRI-CITIES...TO THE LOWER AND MID 40S OVER NORTHERN
KANSAS.
FRIDAY THROUGH SUNDAY...THE OVERALL UPPER FLOW BECOMES MORE ZONAL
WITH THE REAL COLD AIR BOXED UP IN CANADA. THIS WILL ALSO KEEP THE
STORM TRACK WELL TO OUR NORTH RESULTING IN CONTINUED DRY
CONDITIONS. THERE IS GOOD CONFIDENCE IN FRIDAY BEING A VERY NICE
DAY WITH HIGHS LIKELY AROUND 50 IN THE TRI-CITIES TO THE MID AND
UPPER 50S OVER NORTH CENTRAL KANSAS WITH JUST A LIGHT SOUTHWEST
WIND. SATURDAY IS MUCH MORE UNCERTAIN WITH A COLD FRONT ON OUR
DOOR STEP. THE LATEST 00Z ECMWF IS SLOWER WITH THE COLD FRONT AND
INDICATES THAT HIGHS ON SATURDAY MAY BE EVEN WARMER THAN ON FRIDAY
POSSIBLY REACHING INTO THE 60S...BUT THE 00Z GFS IS MUCH QUICKER
WITH THE COLD FRONT AND WOULD HAVE TEMPERATURES FALLING THROUGH
THE 30S SATURDAY AFTERNOON. OUR OFFICIAL FORECAST IS CURRENTLY
SOMEWHERE IN THE MIDDLE WITH A HIGH DEGREE OF UNCERTAINTY AT THIS
TIME. CONFIDENCE REALLY DOES NOT IMPROVE MUCH ON SUNDAY AS THERE
IS UNCERTAINTY WITH REGARD TO HOW COLD THE NEXT AIR MASS WILL BE.
THE 00Z GFS AND 00Z ECMWF HAVE BOTH TRENDED DOWNWARD AND WOULD
RESULT IN HIGHS ONLY IN THE 20S ON SUNDAY WHILE OUR FORECAST STILL
IS INCORPORATING RECENT RUNS THAT WERE WARMER AND IS CALLING FOR
HIGHS IN THE 30S AND 40S. BASICALLY...EXPECT FORECAST CHANGES IN
THE COMING DAYS AS THE UNCERTAINTY ISSUES GET IRONED OUT.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z TUE MORNING)
ISSUED AT 529 AM CST MON NOV 24 2014
TODAY: A PERIOD OF 2000-2500 FT MVFR CIGS APPEARS LIKELY FOR 2-3
HRS THIS MORNING. HIGHEST PROBABILITY AT GRI WHERE WE MADE IT
PREVAILING. CONFIDENCE IS LOWER AT EAR WHERE THE WRN EDGE OF THIS
DECK OF STRATOCU MAY JUST SKIRT THE AIRPORT FOR A TIME. SO HANDLED
WITH JUST A TEMPO GROUP THERE. OTHERWISE...VFR CLEARING AFTER
15Z. NW WINDS WILL GUST 27-32 KTS WITH POTENTIAL FOR A PKWND OF 40
KTS. BBW GUSTED TO 39 KTS LAST HOUR. CONFIDENCE: HIGH
TONIGHT: VFR PATCHES OF PRIMARILY SCT CIRROSTRATUS. NW WINDS
RAPIDLY DIMINISH 23Z-01Z TO AROUND 10 KTS AND THEN GRADUALLY SHIFT
THRU WNW TO W UNDER 10 KTS AFTER 06Z. CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
408 AM CST MON NOV 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 240 AM CST MON NOV 24 2014
ALOFT: THE NEWLY REESTABLISHED LONGWAVE TROF AXIS WAS SHIFTING E
OF THE FCST AREA. BACK TO NW FLOW THRU TONIGHT. THE NEXT SHORTWAVE
TROF TO AFFECT THE FCST AREA WAS OVER BRITISH COLUMBIA. THIS TROF
WILL PASS THRU HERE TONIGHT WITH ONLY AN INCREASE IN HIGH CLOUDS.
SURFACE: THE FCST AREA WAS IN THE COLD SECTOR OF DEEP LOW PRES
OVER THE GREAT LAKES THIS MORNING. WE WILL REMAIN IN THE COLD
SECTOR THRU TONIGHT. WRN USA HIGH PRES WILL GRADUALLY BUILD IN
WITH CYCLONIC BOUNDARY LAYER FLOW BECOMING ANTICYCLONIC. ITS RIDGE
AXIS WILL PASS THRU AFTER MIDNIGHT. A CLIPPER WILL FORM OVER WRN
CANADA TONIGHT AND AN ASSOCIATED WARM FRONT WILL DEVELOP SOUTHWARD
INTO THE REGION.
NOW: TEMPS CONT STRUGGLING TO DROP. TEMPS ARE STILL IN THE 30S
ACROSS THE ENTIRE FCST AREA. SO LOW TEMPS WERE RAISED SVRL DEGS
FROM THE 4 PM FCST.
EARLY THIS MORNING: LOTS OF WRAP AROUND CLOUDS IN CYCLONIC NW
FLOW.
TODAY: CONTINUED WINDY. NW WINDS WILL GUST 30-35 KTS IN DOWNWARD
TRANSFER AS THE BOUNDARY LAYER BECOMES UNSTABLE. POTENTIAL PEAK
GUSTS AS HIGH AS 38 KTS PER BUFKIT MIXING ALGORITHM. USED GFS WITH
ITS DEEPER MIXING.
THE RAP/NAM/GFS AGREE THE WRN FRINGE OF THE WRAP-AROUND CLOUDS
WILL GRADUALLY SHIFT E OF THE FCST AREA LEAVING SKIES SUNNY.
SIMULATED IR IMAGERY FROM THE 4 KM NAM NEST SUGGESTS SOME PATCHES
OF CIRROSTRATUS WILL BEGIN MOVING IN FROM THE NW LATE AND THIS
IS REASONABLE BASED ON CURRENT SATELLITE...WITH THE NRN ROCKIES
SHORTWAVE TROF DIVING TO OUR W.
INTERNAL VERIFICATION SHOWS WE HAVE BEEN RUNNING TOO COOL ON HIGH
TEMPS RECENTLY. SO USED 06Z RAP TO NUDGE TEMPS UPWARD SLIGHTLY.
HIGHS WILL STILL BE 5-10F COLDER THAN NORMAL FOR MOST OF THE FCST
AREA.
TONIGHT: WINDS DROP OFF EARLY EVENING WITH DECOUPLING. PATCHES OF
CIRROSTRATUS CONT TO DRIFT THRU BUT SHOULD BE NO WORSE THAN
P/CLOUDY.
USED THE WEIGHTED CONSENSUS OF THE 3 BEST-VERIFYING TEMP GUIDES
FOR LOWS...WHICH FAVORED THE COLDER MOS TEMPS. JUST SLIGHTLY
COLDER THAN NORMAL.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 407 AM CST MON NOV 24 2014
THE BIG HOLIDAY WEEKEND IS FAST APPROACHING AND NO TRAVEL PROBLEMS
ARE EXPECTED ACROSS NEBRASKA AND KANSAS. ALWAYS REMEMBER YOU CAN
CHECK WWW.WEATHER.GOV FOR THE LATEST WEATHER CONDITIONS AND FORECAST
FOR ANYWHERE IN THE COUNTRY WHERE YOU MIGHT BE TRAVELING TO THIS
HOLIDAY WEEKEND.
THE BIGGEST CONCERN FOR OUR AREA DURING THE HOLIDAY WEEKEND WILL
CENTER AROUND SEVERAL BIG TEMPERATURE SWINGS.
TUESDAY...THIS SHOULD BE A WARMER DAY WITH LIGHTER WINDS. THE STRONG
NORTHWEST WIND OF SUNDAY AND MONDAY WILL GIVE WAY TO A MORE GENTLE
SOUTHWESTERLY BREEZE THAT WILL HELP TO WARM HIGHS INTO THE MID AND
UPPER 40S ACROSS MOST NEBRASKA ZONES TO THE LOWER 50S ACROSS
PORTIONS OF NORTHERN KANSAS. THERE ARE SOME MODEL DIFFERENCES WITH
THE 00Z GFS TRYING TO BRING THE NEXT COLD FRONT INTO NEBRASKA ZONES
BY TUESDAY AFTERNOON ALONG WITH SOME SPRINKLES AND SLIGHTLY COOLER
AIR. HOWEVER...THE 00Z NAM AND 00Z GFS ARE BOTH SLOWER WITH THE COLD
FRONT AND ARE DRY. THIS FORECAST LEANS TOWARDS THE ECMWF/NAM
SOLUTION.
TUESDAY NIGHT INTO WEDNESDAY...COOLER AIR WILL FILTER INTO OUR
REGION BEHIND A COLD FRONT. WE CAN NOT RULE OUT A FLURRY OR
TWO...BUT GIVEN MOST FORECAST MODELS ARE COMPLETELY DRY...WE WILL
KEEP THE FORECAST DRY AND WITHHOLD ANY FLURRIES FOR NOW. FORECAST
MODELS ARE NOT AS COLD WITH THIS AIRMASS AS THEY WERE SEVERAL DAYS
AGO AND EXPECT HIGHS ON WEDNESDAY SHOULD STILL REACH THE UPPER 30S
ACROSS NORTHEASTERN ZONES TO THE MID 40S OVER NORTH CENTRAL KANSAS.
THANKSGIVING...UNFORTUNATELY THE HOLIDAY ITSELF APPEARS TO THE BE
COLDEST DAY OF THE WEEKEND AS THE COOLER AIR THAT SETTLES IN ON
WEDNESDAY MAY HANG AROUND THROUGH THANKSGIVING DAY.
HOWEVER...FORECAST MODELS HAVE BEEN TRENDING WARMER AND SO WOULD NOT
BE SURPRISED IF OUR FORECAST HIGHS ON THANKSGIVING DAY EVENTUALLY
GET RAISED SOME. FOR NOW WILL CONTINUE TO GO WITH THE OVERALL
SUPERBLEND OF MODELS...WHICH RESULTS IN HIGHS IN THE MID 30S IN THE
TRI-CITIES...TO THE LOWER AND MID 40S OVER NORTHERN KANSAS.
FRIDAY THROUGH SUNDAY...THE OVERALL UPPER FLOW BECOMES MORE ZONAL
WITH THE REAL COLD AIR BOXED UP IN CANADA. THIS WILL ALSO KEEP THE
STORM TRACK WELL TO OUR NORTH RESULTING IN CONTINUED DRY CONDITIONS.
THERE IS GOOD CONFIDENCE IN FRIDAY BEING A VERY NICE DAY WITH HIGHS
LIKELY AROUND 50 IN THE TRI-CITIES TO THE MID AND UPPER 50S OVER
NORTH CENTRAL KANSAS WITH JUST A LIGHT SOUTHWEST WIND. SATURDAY IS
MUCH MORE UNCERTAIN WITH A COLD FRONT ON OUR DOOR STEP. THE LATEST
00Z ECMWF IS SLOWER WITH THE COLD FRONT AND INDICATES THAT HIGHS ON
SATURDAY MAY BE EVEN WARMER THAN ON FRIDAY POSSIBLY REACHING INTO
THE 60S...BUT THE 00Z GFS IS MUCH QUICKER WITH THE COLD FRONT AND
WOULD HAVE TEMPERATURES FALLING THROUGH THE 30S SATURDAY AFTERNOON.
OUR OFFICIAL FORECAST IS CURRENTLY SOMEWHERE IN THE MIDDLE WITH A
HIGH DEGREE OF UNCERTAINTY AT THIS TIME. CONFIDENCE REALLY DOES NOT
IMPROVE MUCH ON SUNDAY AS THERE IS UNCERTAINTY WITH REGARD TO HOW
COLD THE NEXT AIR MASS WILL BE. THE 00Z GFS AND 00Z ECMWF HAVE BOTH
TRENDED DOWNWARD AND WOULD RESULT IN HIGHS ONLY IN THE 20S ON SUNDAY
WHILE OUR FORECAST STILL IS INCORPORATING RECENT RUNS THAT WERE
WARMER AND IS CALLING FOR HIGHS IN THE 30S AND 40S.
BASICALLY...EXPECT FORECAST CHANGES IN THE COMING DAYS AS THE
UNCERTAINTY ISSUES GET IRONED OUT.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z MON NIGHT)
ISSUED AT 1159 PM CST SUN NOV 23 2014
OVERNIGHT: VARIABLE MULTI-LAYERED VFR CLOUDS MOSTLY BETWEEN 4-10K
FT. THERE IS A LOW PROBABILITY FOR A TEMPO MVFR CEILING BETWEEN
2500-3000 FT...ESPECIALLY AT GRI. CONFIDENCE IS NOT HIGH ENOUGH
TO INCLUDE IN THE TAFS. NW WINDS WILL BE HIGHLY VARIABLE IN SPEEDS
AND GUSTS. DURING TIMES WHEN WINDS DECREASE TO 10-15 KTS...SOME
LLWS IS PROBABLE. OTHERWISE...WINDS WILL GUST UP TO 35 KTS AT
TIMES. CONFIDENCE: MEDIUM
MON: MULTI-LAYERED VFR CIGS WILL DIMINISH WITH GRADUAL CLEARING
DURING THE MORNING HRS. NW WINDS WILL GUST UP TO 30 KTS.
CONFIDENCE: HIGH
MON EVE: VFR WITH CIRROSTRATUS CIGS INVADING. NW WINDS DIMINISH
AND SETTLE AROUND 10 KTS. CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
240 AM CST MON NOV 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 240 AM CST MON NOV 24 2014
ALOFT: THE NEWLY REESTABLISHED LONGWAVE TROF AXIS WAS SHIFTING E
OF THE FCST AREA. BACK TO NW FLOW THRU TONIGHT. THE NEXT SHORTWAVE
TROF TO AFFECT THE FCST AREA WAS OVER BRITISH COLUMBIA. THIS TROF
WILL PASS THRU HERE TONIGHT WITH ONLY AN INCREASE IN HIGH CLOUDS.
SURFACE: THE FCST AREA WAS IN THE COLD SECTOR OF DEEP LOW PRES
OVER THE GREAT LAKES THIS MORNING. WE WILL REMAIN IN THE COLD
SECTOR THRU TONIGHT. WRN USA HIGH PRES WILL GRADUALLY BUILD IN
WITH CYCLONIC BOUNDARY LAYER FLOW BECOMING ANTICYCLONIC. ITS RIDGE
AXIS WILL PASS THRU AFTER MIDNIGHT. A CLIPPER WILL FORM OVER WRN
CANADA TONIGHT AND AN ASSOCIATED WARM FRONT WILL DEVELOP SOUTHWARD
INTO THE REGION.
NOW: TEMPS CONT STRUGGLING TO DROP. TEMPS ARE STILL IN THE 30S
ACROSS THE ENTIRE FCST AREA. SO LOW TEMPS WERE RAISED SVRL DEGS
FROM THE 4 PM FCST.
EARLY THIS MORNING: LOTS OF WRAP AROUND CLOUDS IN CYCLONIC NW
FLOW.
TODAY: CONTINUED WINDY. NW WINDS WILL GUST 30-35 KTS IN DOWNWARD
TRANSFER AS THE BOUNDARY LAYER BECOMES UNSTABLE. POTENTIAL PEAK
GUSTS AS HIGH AS 38 KTS PER BUFKIT MIXING ALGORITHM. USED GFS WITH
ITS DEEPER MIXING.
THE RAP/NAM/GFS AGREE THE WRN FRINGE OF THE WRAP-AROUND CLOUDS
WILL GRADUALLY SHIFT E OF THE FCST AREA LEAVING SKIES SUNNY.
SIMULATED IR IMAGERY FROM THE 4 KM NAM NEST SUGGESTS SOME PATCHES
OF CIRROSTRATUS WILL BEGIN MOVING IN FROM THE NW LATE AND THIS
IS REASONABLE BASED ON CURRENT SATELLITE...WITH THE NRN ROCKIES
SHORTWAVE TROF DIVING TO OUR W.
INTERNAL VERIFICATION SHOWS WE HAVE BEEN RUNNING TOO COOL ON HIGH
TEMPS RECENTLY. SO USED 06Z RAP TO NUDGE TEMPS UPWARD SLIGHTLY.
HIGHS WILL STILL BE 5-10F COLDER THAN NORMAL FOR MOST OF THE FCST
AREA.
TONIGHT: WINDS DROP OFF EARLY EVENING WITH DECOUPLING. PATCHES OF
CIRROSTRATUS CONT TO DRIFT THRU BUT SHOULD BE NO WORSE THAN
P/CLOUDY.
USED THE WEIGHTED CONSENSUS OF THE 3 BEST-VERIFYING TEMP GUIDES
FOR LOWS...WHICH FAVORED THE COLDER MOS TEMPS. JUST SLIGHTLY
COLDER THAN NORMAL.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 159 AM CST MON NOV 24 2014
THIS SECTION WILL UPDATE AROUND 4 AM.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z MON NIGHT)
ISSUED AT 1159 PM CST SUN NOV 23 2014
OVERNIGHT: VARIABLE MULTI-LAYERED VFR CLOUDS MOSTLY BETWEEN 4-10K
FT. THERE IS A LOW PROBABILITY FOR A TEMPO MVFR CEILING BETWEEN
2500-3000 FT...ESPECIALLY AT GRI. CONFIDENCE IS NOT HIGH ENOUGH
TO INCLUDE IN THE TAFS. NW WINDS WILL BE HIGHLY VARIABLE IN SPEEDS
AND GUSTS. DURING TIMES WHEN WINDS DECREASE TO 10-15 KTS...SOME
LLWS IS PROBABLE. OTHERWISE...WINDS WILL GUST UP TO 35 KTS AT
TIMES. CONFIDENCE: MEDIUM
MON: MULTI-LAYERED VFR CIGS WILL DIMINISH WITH GRADUAL CLEARING
DURING THE MORNING HRS. NW WINDS WILL GUST UP TO 30 KTS.
CONFIDENCE: HIGH
MON EVE: VFR WITH CIRROSTRATUS CIGS INVADING. NW WINDS DIMINISH
AND SETTLE AROUND 10 KTS. CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...WESELY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
804 PM EST TUE NOV 25 2014
.SYNOPSIS...
A STORM SYSTEM MOVING ALONG THE EAST COAST WEDNESDAY INTO THURSDAY
MORNING WILL IMPACT ALL OF NORTHEAST PENNSYLVANIA AND A LARGE PART
OF CENTRAL NEW YORK WITH A SIGNIFICANT SNOWFALL. THE HEAVIEST SNOW
IS EXPECTED FROM THE POCONOS TO THE WESTERN CATSKILLS. SNOW WILL
DEVELOP LATE TONIGHT AND LAST THROUGH WEDNESDAY AND TAPER OFF TO
SNOW SHOWERS WEDNESDAY NIGHT AND EARLY THURSDAY. SNOWFALL OF 5 TO
12 INCHES IS EXPECTED FROM NORTHEAST PENNSYLVANIA TO THE CATSKILLS
WITH 2 TO 6 INCHES TO THE NORTH AND WEST. LESS THAN 2 INCHES OF SNOW
IS EXPECTED ACROSS THE NORTHERN FINGER LAKES REGION TO THE
SYRACUSE AREA.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
8 PM UPDATE...
L/WV TROF IS MVG THRU MS VLY AT THIS TIME WITH STRONG S/WV
ROUNDING BASE OF TROF OVR LWR MS RVR. CYCLOGENESIS UNDERWAY ACRS
NE GOM WITH PCPN NOW BEING REPORTED AS FAR NORTH AS THE PIEDMONT
OF NC. LATEST MODELS HV TRENDED JUST A TAD SLOWER WITH PCPN
EXPECTED TO MV INTO CWA CLOSER TO 12Z. RUC AND HIRES ARW SEEM TO
HV BEST HANDLE ON PCPN AS OF 00Z AND NOT SHOWING MUCH IN THE WAY
OF ECHOES MVG INTO POCONOS UNTIL 11Z AT THE EARLIEST.
AS PCPN HEADS NORTH EXPECTING TO SEE JUST A WALL OF SNOW HEADING
AT US. THUS HV GONE FM LOCHC POPS TO CATEGORICAL DRG THE MRNG HRS.
18Z NAM HAS TRENDED A TAD WETTER AND FURTHER WEST WITH PCPN WITH
24-HR AMNTS OVR 1+ INCHES OVR FAR SE ZONES AND 0.75 INCHES AS FAR
WEST AS AN ELMIRA-UTICA LINE. WL EVALUATE 00Z GUIDANCE COMING IN
AND POSSIBLY EXPAND WARNINGS/ADVISORIES FURTHER WEST OVRNGT.
FOR NOW, HV LWRD SNOW AMNTS BTWN 06Z AND 12Z OVR NEPA AND ADJUSTED
AMNTS HIGHER FOR THE 12Z-18Z TIMEFRAME AS THIS LOOKS TO BE
PRIMETIME. CONCERN IS THAT MESOSCALE BANDING WL SET UP JUST A HAIR
FURTHER WEST LATE MRNG OR EARLY AFTN THAN MODELS ARE INDICATING.
TREMENDOUS VERTICAL MOTION EXPECTED LATE MRNG INTO THE AFTN HRS IN
AREA OF ENHANCE UPWARD DIFFLUENCE AS CWA WL LKLY BE IN RRQ OF H2
JET. NO OTHER ADJUSTMENTS NEEDED AT THIS TIME.
PREV DISCUSSION BLO...
ISSUED WINTER STORM WARNINGS FOR MOST OF NORTHEAST PENNSYLVANIA
AND THE WESTERN CATSKILLS IN LINE WITH NEIGHBORING OFFICES AND
BASED ON THE LATEST MODEL GUIDANCE WWD AND MODEL QPFS. MODELS ALL
INDICATE THAT CYCLOGENESIS BEGINS ALONG THE EAST COAST WEDNESDAY
INTO WEDNESDAY NIGHT AS A STRONG UPPER LEVEL WAVE ROUNDS THE BASE
OF THE UPPER LEVEL TROUGH OVER THE EASTERN UNITED STATES. THE
STORM WILL NOT CLOSE OFF AT 700 MB UNTIL IT IS NORTHEAST OF THE
REGION AS THE SYSTEM GETS CAUGHT UP IN THE STRG SWRLY FLOW ALOFT.
THIS WILL LEAD TO LESS LINGERING WRAP ARND ACCUMULATIONS THAT WE
OFTEN SEE IN C NY/NRN PA. BASICALLY THIS SYSTEM WILL RUN INTO UPPER
CONFLUENCE OVER THE MARITIMES BY THURSDAY AND SHEAR OUT. BUT IN THE
PROCESS SIGNIFICANT WARM CONVEYOR BELT MOISTURE IS RUNNING INTO
THE UPPER DIFFLUENCE OF THE RIGHT ENTRANCE REGION OF THE UPPER JET
OVER SERN CANADA. THIS IS FAVORABLE FOR A SWATH OF HEAVY SNOW.
MODELS ARE SHOWING THAT THE HEAVIEST SNOW IN OUR FORECAST AREA IS
FROM NE PA TO DELAWARE/SULLIVAN CO/S IN NY.
CROSS SECTIONS NORMAL TO THE THICKNESS ACROSS NE AND C NY SHOW A
CLASSIC SLOPED LAYER OF FGEN FORCING WED PM WITH LOW STATIC
STABILITY ABOVE OR EVEN WEAKLY UNSTABLE ALOFT. THIS IS A RECIPE
FOR MESOSCALE SNOW BANDS AND BELIEVE A BAND OF HEAVY SNOW WILL
FORM SOMEWHERE IN OUR WARNING AREA. IN GRIDS HAVE MENTION OF
HEAVY SNOW IN THIS AREA. I ALSO AM CONCERNED THAT THIS BAND COULD
TRACK FARTHER WEST AS IS OFTEN THE CASE AND IMPACT OUR ADVY AREA. THE
12Z EURO NOW HAS MORE QPF FARTHER WEST TOO. FOR NOW HAVE A ROW OF
WINTER WX ADVY/S AS A BUFFER ZONE FROM TOWANDA TO BINGHAMTON TO
COOPERSTOWN AND NORWICH. THIS AREA COULD GET INTO SOME HEAVY SNOW.
IT DEPENDS ON WHERE THIS MESOSCALE BAND SETS UP. LATER SHIFTS WILL
HAVE TO MONITOR. OUR BRIEFINGS WILL MENTION THE CHANCE THAT SOME
HEAVIER SNOW COULD FALL FARTHER WEST.
FOR THE REST OF WEDNESDAY NIGHT...SNOW WILL RAPIDLY TAPER DOWN TO
SNOW SHOWERS FROM SW TO NE AS THE STORM PULLS TO THE NORTHEAST.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
300 PM EST UPDATE...
CAA WILL CONTINUE TO TAKE PLACE ACROSS THE CWA THURS AS THE SFC
LOW MOVES FURTHER NORTH ALONG THE EAST COAST. THIS WILL ALLOW COOLER
AIR TO MOVE INTO PORTIONS OF NY AND PA. THIS WILL RESULT IN THURS
BEING FAIRLY COLD WITH TEMPERATURES ONLY RISING INTO THE LOW TO
MID 30S. EVEN THOUGH THE POTENT STORM THAT HAVE CAUSED WARNINGS
ACROSS THE EAST WILL BE WELL TO THE NORTH BY THURS... THIS DOES
NOT MEAN AN END TO SNOW SHOWERS OVER THE CWA. THE CHANCE FOR SNOW
ACROSS OUR AREA WILL STILL CONTINUE. SCATTERED SNOW SHOWERS WILL
STILL BE POSSIBLE THROUGH THE DAY ON THURSDAY. THESE SNOW SHOWERS
WILL BE THE RESULT FROM AN ALBERTA CLIPPER PASSING THROUGH.
THESE SHOWERS ARE EXPECTED TO TO BE LIGHT AND SCATTERED IN NATURE.
SOME LAKE EFFECT ACTIVITY WILL BE POSSIBLE BEHIND THE PASSAGE OF
THE CLIPPER. THE BEST CHANCE FOR LE SNOW SHOWERS WILL BE SHORTLY
AFTER 00Z FRIDAY THROUGH 00Z SATURDAY. TEMPS WILL BE A FEW DEGREES
COOLER ON FRIDAY ACROSS MUCH OF THE AREA AS A VERY COLD AIRMASS
WILL REMAIN OVER NY AND PA. SHOWERS ARE EXPECTED TO SLOWLY
DIMINISH FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
300 PM EST UPDATE...
HAVE MADE MINOR ADJUSTMENTS TO THE PREVIOUS FORECAST AND CLOSELY
FOLLOWED WPC GUIDANCE.
THE FLOW ALOFT WILL REMAIN ZONAL ACROSS MUCH OF THE EASTERN CONUS
THROUGH THE FORECAST PERIOD. BUT SADLY THIS DOES NOT MEAN THE WX
PATTERN WILL REMAIN QUIET THROUGH THE EXTENDED. THERE APPEARS TO
BE A CHANCE FOR EITHER SNOW OR RAIN THROUGH THE EXTENDED.
A WEAK LOW PRESSURE SYSTEM WILL FORCE A WARM FRONT ACROSS THE
REGION EARLY SAT THEN SLOWLY BRING A COLD FRONT ACROSS THE CWA ON
SUNDAY. GUIDANCE IS UPON FAIRLY GOOD AGREEMENT ON KEEPING THE SFC
LOW WELL TO THE NORTH OF THE CWA. GUIDANCE HINTS AT HIGH PRESSURE
BUILDING STARTING TO BUILD OVER REGION ON MONDAY. THIS MAY
BRIEFLY HALT THE CHANCE FOR SHOWERS OVER THE REGION EARLY NEXT WEEK.
&&
.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
A LARGE WINTER STORM WILL PRODUCE WIDESPREAD IFR VSBYS AT ALL
TERMINALS WEDNESDAY.
TIMING OF SNOW LOOKS TO BE BETWEEN 12Z AND 15Z SOUTHERN TERMINALS,
AND AFTER 15Z UP NORTH. AIRPORT MINS WILL BE APPROACHED AT
KBGM/KAVP A FEW HOURS AFTER THE ONSET OF THE SNOW, THROUGH THE END
OF THE TAF PERIOD. FARTHER NORTH AND WEST FROM KELM TO KITH, KSYR,
AND KRME IFR VSBYS LIKELY BUT NOT AS LOW AS FARTHER SOUTH.
OUTLOOK...
WED NGT...COASTAL SYSTEM MAY IMPACT REGION WITH RESTRICTIONS FROM
SNOW...BEST CHANCE KAVP.
THU/FRI/SAT...POSSIBLE RESTRICTIONS FROM SCT -SHSN...ESPECIALLY
KSYR-KRME.
SUN...RESTRICTIONS POSSIBLE FROM -SHRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WARNING FROM 3 AM WEDNESDAY TO 6 AM EST THURSDAY
FOR PAZ039-040-043-044-047-048-072.
WINTER WEATHER ADVISORY FROM 3 AM WEDNESDAY TO 6 AM EST
THURSDAY FOR PAZ038.
NY...WINTER STORM WARNING FROM 3 AM WEDNESDAY TO 6 AM EST THURSDAY
FOR NYZ057-062.
WINTER WEATHER ADVISORY FROM 3 AM WEDNESDAY TO 6 AM EST
THURSDAY FOR NYZ045-046-055-056.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN/PVF
SHORT TERM...KAH
LONG TERM...KAH
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
952 PM EST TUE NOV 25 2014
.SYNOPSIS...
RAIN WILL CONTINUE TONIGHT INTO WEDNESDAY MORNING AS LOW PRESSURE
MOVES UP THE SOUTHEAST COAST. SKIES WILL CLEAR OUT BY THANKSGIVING
DAY...WITH TEMPERATURES RUNNING SEVERAL DEGREES BELOW NORMAL INTO
THE WEEKEND BEFORE WARMER TEMPERATURES RETURN EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 1000 PM TUESDAY...SO FAR SO GOOD WITH THE EARLIER CHANGES TO
QPF AMOUNTS. WITH THE EXCEPTION OF A NARROW BAND OVER WILMINGTON
WHICH IS DROPPING FAIRLY HEAVY RAIN NOW...RATES ARE 0.05 INCHES PER
HOUR OR LESS ACROSS THE BULK OF THE FORECAST AREA. RADAR COMPOSITES
SOUTH TO THE FLORIDA GEORGIA LINE SHOW A SIZABLE GAP IN RAINFALL...
PERHAPS KEEPING THOSE RED CLAY ROADS A LITTLE LESS MUDDY THAN THEY
OTHERWISE MIGHT BE. DEEP CONVECTION CONTINUES ACROSS CENTRAL FLORIDA
AND OFF THE FLORIDA EAST COAST AND THIS SHOULD CONTINUE TO
NEGATIVELY IMPACT OUR PRECIPITATION INTENSITY FOR THE NEXT 3-5 HOURS.
LATEST HRRR MODEL RUNS SHOW THE SYNOPTIC LOW MAY ACTUALLY MOVE
INLAND BRIEFLY ACROSS SE NORTH CAROLINA AROUND 11-12Z WED. A TRACK
THIS FAR WEST WOULD KEEP LOW TEMPERATURES IN WILMINGTON IN THE 60S
DUE TO ONSHORE EASTERLY FLOW. I HAVE TWEAKED THE IMPLIED SYNOPTIC
LOW TRACK A LITTLE CLOSER TO THE COAST...JUST NICKING BALD HEAD
ISLAND BEFORE DAYBREAK. PREVIOUS DISCUSSION FROM 700 PM FOLLOWS...
WE ARE ENTERING THE PERIOD OF WHAT SHOULD BE THE STRONGEST UPPER
LEVEL DIVERGENCE AND LOW-TO-MID LEVEL ISENTROPIC LIFT NOW. 305K-310K
ISENTROPIC LIFT FORECASTS FROM THE 18Z NAM OR GFS SUGGEST IT SHOULD
BE POURING EVERYWHERE! HOWEVER THE BROAD-SCALE RADAR COMPOSITE SHOWS
THE FORECAST PROBLEM FOR TONIGHT: WIDESPREAD DEEP CONVECTION ACROSS
THE FLORIDA PENINSULA AND OFFSHORE EAST OF JAX IS PRODUCING
DOWNSTREAM MID-LEVEL WARMING AND DRYING THAT IS NEGATIVELY IMPACTING
PRECIPITATION COVERAGE ACROSS SOUTH GEORGIA AND THE CAROLINAS. THIS
IS A CLASSIC PROBLEM WE SEE LOCALLY DURING THE COOL SEASON THAT HAS
FRANKLY NEVER BEEN HANDLED WELL BY THE SYNOPTIC MODELS.
BOTH THE HRRR AND HRRRX (AN EXPERIMENTAL VERSION AVAILABLE ON THE
RAPIDREFRESH.NOAA.GOV SERVER) ARE INITIALIZING WITH THE CORRECT
"HOLE" IN THE PRECIPITATION SHIELD AND SHOW THIS ANOMALY MAY
CONTINUE TO PLAGUE THE REGION`S RAINFALL FORECAST THROUGH THE NIGHT.
THE 18Z SYNOPTIC RAINFALL GUIDANCE FROM WPC ALSO SEEMS TO AGREE WITH
THIS IDEA OF LESSER RAINFALL TOTALS THAN ORIGINALLY THOUGHT. WITH
THIS IN MIND I HAVE KEPT FORECAST POPS AT 100% (EVERYONE WILL GET AT
LEAST 0.01 INCHES OF RAIN) BUT I HAVE TRIMMED BACK FORECAST RAINFALL
AMOUNTS SUBSTANTIALLY. FROM RIGHT NOW THROUGH THE END OF THE EVENT
LATE WEDNESDAY MORNING IT APPEARS TOTALS SHOULD AVERAGE HALF OF AN
INCH...PERHAPS APPROACHING AN INCH ALONG THE COAST IF RAINFALL RATES
CAN INCREASE TOWARD THE END OF THE EVENT WEDNESDAY MORNING.
OVER THE PAST FEW DAYS SYNOPTIC GUIDANCE HAS TRENDED FARTHER WEST
WITH THE FORECAST PATH OF THE LOW MOVING NORTH FROM FLORIDA. 18Z
MODELS CONTINUED THIS TREND AND I HAVE SHIFTED THE IMPLIED TRACK OF
THE LOW IN THE FORECAST WIND GRIDS TO ONLY ABOUT 10 MILES EAST OF
CAPE FEAR LATE TONIGHT. THIS WILL HAVE THE ADDED IMPACT OF
MAINTAINING A WARMER AIRMASS NEAR THE COAST...PARTICULARLY SE NORTH
CAROLINA...AND I HAVE RAISED FORECAST LOWS BY SEVERAL DEGREES HERE.
FARTHER INLAND THE COLD AIR SHOULD BEGIN TO BLEED IN FROM THE NW
SHORTLY AND VERY FEW CHANGES WERE NEEDED TO THE OVERALL TEMP/WIND
FORECAST.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...LOW PRESSURE HUGGING THE COAST WILL BE MOVING
N OF THE WATERS WEDNESDAY MORNING. AS THE LOW MOVES UP THE NORTH
CAROLINA AND MID ATLANTIC COAST WED...THE RAIN WILL SHUT OFF FROM
SSW TO NNE. PERIODS OF HEAVY RAIN ARE STILL POSSIBLE WED
MORNING...BUT EXPECT BY AFTERNOON...THE RISK FOR RAINFALL WILL HAVE
ENDED ACROSS ALL BUT THE CAPE FEAR AREA WHERE A SLIGHT RISK OF
AFTERNOON RAIN WILL STILL BE POSSIBLE. WILL INCLUDE CATEGORICAL POPS
WED MORNING THROUGHOUT. CONVECTION IS EXPECTED TO STAY OFFSHORE...
EAST OF THE LOW CENTER WHERE THERE WILL BE AN INFLUX OF WARMER AND
MORE UNSTABLE AIR.
ONE VERY POTENT MID-LEVEL SHORTWAVE TROUGH WILL PIVOT ACROSS THE
FORECAST AREA WED AFTERNOON WHILE ANOTHER SKIRTS OUR FORECAST AREA
TO THE N LATE WED NIGHT AND THU MORNING BEFORE LIFTING OUT. THE
INFLUX OF COLDER AND DRIER AIR WORKING INTO THE EASTERN CAROLINAS ON
THE BACKSIDE OF FIRST SHORTWAVE WILL HELP TO SIGNIFICANTLY DRY THE
COLUMN WITH PRECIPITABLE WATER VALUES DROPPING TO LESS THAN HALF AN
INCH. THIS WILL HELP TO PROMOTE DECREASING AFTERNOON CLOUDINESS...
ESPECIALLY ACROSS SOUTHERN AND WESTERN ZONES. THE SECOND SHORTWAVE
MAY ACTUALLY BRING A BRIEF INCREASE IN CLOUD COVER...BUT
PRECIPITATION IS EXPECTED TO REMAIN TO OUR N.
TEMPS ON WED WILL NOT MOVE MUCH AS COLD AIR ADVECTION GETS UNDERWAY.
IN FACT HIGHS WILL BE ACHIEVED IN MANY CASES PRIOR TO OR AROUND
SUNRISE. WE EXPECT HIGHS TO BE IN THE LOWER TO MID 50S ON THE COAST
WITH UPPER 40S TO AROUND 50 FROM EYF TO HYW AND POINTS W. DAYTIME
TEMPS WILL HOLD STEADY OF NOT DROP A DEGREE OR TWO. TEMPS WED NIGHT
WILL DROP INTO THE 30S TO AROUND 40. EVEN THE COLDEST SPOTS SHOULD
NOT REACH THE FREEZING MARK GIVEN THE LACK OF RADIATIONAL COOLING.
CHILLY HIGH PRESSURE WORKING TO THE COAST FROM THE W WILL ALLOW THE
PRESSURE GRADIENT TO LOOSEN THU NIGHT. THE COOLEST TEMPS AT 850 MB
THU WILL BE OFFSET BY SUNSHINE AND WE DO EXPECT HIGHS TO STILL REACH
THE MID 50S. RADIATIONAL COOLING WILL DEVELOP THU NIGHT WHICH SHOULD
ALLOW LOWS TO DROP INTO THE UPPER 20S TO LOWER 30S OVERNIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...LONG TERM PERIOD WILL REMAIN DRY WITH MID
LEVEL FLOW BECOMING PROGRESSIVE. COLD ADVECTION WILL BE WINDING DOWN
FRI...BUT TEMPS STILL END UP WELL BELOW CLIMO. DEEP WESTERLY FLOW
WILL BE QUICK TO SHIFT THE CENTER OF THE MODIFYING HIGH OFF THE
COAST WITH RETURN FLOW DEVELOPING SAT. TEMPS REMAIN BELOW CLIMO SAT
BUT WILL BE WARMER THAN FRI. EARLY NEXT WEEK 5H RIDGE TRIES TO BUILD
NORTH FROM THE EASTERN GOMEX AND FL. BUILDING HEIGHTS AND INCREASING
SOUTHWEST FLOW EARLY NEXT WEEK WILL PUSH TEMPS ABOVE CLIMO. BACKDOOR
COLD FRONT DEPICTED IN MEDIUM RANGE GUIDANCE YESTERDAY NOW LOOKS
TIMED TO CROSS THE AREA TUE MORNING...WITH BOTH GFS/ECMWF IN DECENT
AGREEMENT. FRONT WILL PASS DRY FOLLOWED BY WEAK COLD ADVECTION WITH
TEMPS DROPPING BACK NEAR CLIMO.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 00Z...EXPECT VFR/MVFR CONDITIONS EARLY THIS EVENING TO
DETERIORATE TO IFR AS RAIN CONTINUES THROUGH THE OVERNIGHT HOURS. A
SHALLOW LAYER OF LIGHT NORTHEAST WINDS BEHIND THE FRONT WILL HELP TO
PROMOTE IFR STRATUS AS MOISTURE IS TRAPPED BENEATH A LOW-LEVEL
INVERSION. MEANWHILE...A DEVELOPING AREA OF LOW PRESSURE ALONG THE
FRONT WILL MOVE UP THE SOUTHEAST COAST OVERNIGHT... BRINGING MORE
PERSISTENT RAIN THAT MAY LOWER VSBYS TO MVFR/IFR LEVELS AT TIMES.
LIGHT NORTHEAST WINDS WILL BECOME MORE NORTHERLY AFTER MIDNIGHT...
AND THEN NORTHWEST BY 12Z ON THE BACK SIDE OF THE LOW AS IT MOVES UP
THE MID-ATLANTIC COAST. THE ENHANCED GRADIENT WILL RESULT IN GUSTY
NORTHWEST WINDS 15-20 KT DURING THE MORNING/EARLY AFTN HOURS.
CONDITIONS WILL IMPROVE FROM SW TO NE ACROSS OUR AREA DURING THE
AFTN AS THE LOW RACES AWAY AND DRIER AIR IS PULLED INTO THE
CAROLINAS. RAIN SHOULD END BY 18Z AS MVFR CIGS GRADUALLY IMPROVE TO
VFR BY THE END OF THE PERIOD.
EXTENDED OUTLOOK...VFR CONDITIONS EXPECTED THURSDAY THROUGH SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 PM TUESDAY...LATEST HRRR MODEL RUNS SHOW THE LOW TRACKING
A BIT FARTHER WEST THAN THE AFTERNOON MODELS INDICATED. I HAVE
TWEAKED THE IMPLIED TRACK OF THE LOW ANOTHER 5 MILES WEST IN THE
LATEST GRIDDED WIND FORECAST...JUST NICKING BALD HEAD ISLAND BEFORE
DAYBREAK. THIS WOULD BRING SOUTHERLY WINDS ACROSS MOST OF THE
COASTAL WATERS NORTH OF CAPE FEAR LATE TONIGHT. OTHERWISE FEW
CHANGES WERE NEEDED TO THE FORECAST THIS EVENING. PREVIOUS
DISCUSSION FROM 700 PM FOLLOWS...
THE CAROLINA COASTAL WATERS ARE IN A LULL CURRENTLY AS LOW PRESSURE
DEVELOPS ALONG A FRONT STALLED ACROSS THE FLORIDA PENINSULA. THIS
FRONT EXTENDS NORTHEASTWARD TO VERY NEAR CAPE FEAR WHICH EXPLAINS
THE WEAK PRESSURE GRADIENT WE SEE ON SURFACE CHARTS. AS THE NIGHT
PROGRESSES THE LOW SHOULD FOLLOW THE FRONT
NORTH-NORTHEASTWARD...GRADUALLY DEEPENING AND PASSING JUST EAST OF
CAPE FEAR BEFORE DAYBREAK WEDNESDAY MORNING. WITH THE FRONT
REMAINING JUST OFF THE COAST WE SHOULD NOT SEE VERY STRONG WINDS
ACROSS THE COASTAL WATERS TONIGHT...15 KNOTS OR LESS THROUGH EARLY
WEDNESDAY MORNING. THE EXCEPTION TO THIS MAY BE ACROSS THE WATERS
10-20 MILES EAST OF CAPE FEAR WHERE STRONG SOUTH WINDS DEVELOPING
AROUND MIDNIGHT AHEAD OF THE INTENSIFYING LOW COULD REACH 25 KNOTS.
CERTAINLY OFFSHORE BEYOND 20 MILES WINDS ARE GOING TO INTENSIFY
QUITE A BIT OVER THE NEXT 6 HOURS AHEAD OF THE LOW. THIS WILL BE
IMPORTANT SINCE SEAS WILL BUILD QUITE SUBSTANTIALLY OFFSHORE...AND A
GOOD DEAL OF SOUTHERLY SWELL ENERGY SHOULD PROPAGATE INTO THE
COASTAL WATERS BEGINNING LATE THIS EVENING. FOR THIS REASON THE
SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT FOR THESE 4-6 FOOT SEAS
DEVELOPING AFTER MIDNIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...SMALL CRAFT ADVISORY CONDITIONS WILL CONTINUE
THROUGH THE DAY WED. WE DO THINK THESE CONDITIONS MAY WANE WED EVE.
HOWEVER...IT IS POSSIBLE THAT SMALL CRAFT ADVISORY CONDITIONS
REDEVELOP FOR A TIME LATE WED NIGHT AND THU AS BACKSWELL FROM
COASTAL LOW PRESSURE WELL NORTH OF THE AREA WORKS DOWN THE COAST.
ALSO...THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE TO OUR W AND
COASTAL LOW WILL HELP TO INCREASE LOW-LEVEL WIND SPEEDS AS SURGE OF
COLDEST AIR ARRIVES ACROSS THE WATERS. THE WIND DIRECTION WILL BE NW
OR TRANSITIONING TO NW WED MORNING AS THE LOW MOVES FURTHER UP THE
COAST. THE DIRECTION WILL THEN BACK TO A MORE WESTERLY DIRECTION WED
NIGHT AND THU. AS HIGH PRESSURE TO THE W BEGINS TO ASSERT ITSELF
LATE THU AND THU NIGHT...THE WIND DIRECTION WILL VEER TO NW AND THEN
N. HIGHEST WIND SPEEDS THIS PERIOD WILL BE UP TO 20 TO 25 KT AND
SEAS UP TO 5 TO 8 FT.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...DECREASING NORTHWEST FLOW ON FRI WILL BECOME
LIGHT AND VARIABLE FRI NIGHT INTO SAT AS SURFACE RIDGE AXIS MOVES
OVERHEAD. LIGHT SOUTHERLY FLOW DEVELOPS SAT AFTERNOON AS THE
CENTER OF THE HIGH PUSHES EAST OF THE WATERS. GRADIENT BECOMES A
LITTLE MORE DEFINED LATER SAT WITH SOUTHWEST FLOW INCREASING TO 10
TO 15 KT SAT NIGHT AND SUN. SEAS 2 TO 4 FT FRI MORNING DROP TO 2
TO 3 FT FRI NIGHT AND 2 FT OR LESS SAT AND SUN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 7 PM EST
WEDNESDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...III
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
655 PM EST TUE NOV 25 2014
.SYNOPSIS...
SIGNIFICANT RAINFALL IS EXPECTED TONIGHT INTO WEDNESDAY AS LOW
PRESSURE MOVES UP THE SOUTHEAST COAST. SKIES WILL CLEAR OUT BY
THANKSGIVING DAY...WITH TEMPERATURES RUNNING SEVERAL DEGREES
BELOW NORMAL INTO THE WEEKEND BEFORE WARMER TEMPERATURES RETURN
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 700 PM TUESDAY...WE ARE ENTERING THE PERIOD OF WHAT SHOULD BE
THE STRONGEST UPPER LEVEL DIVERGENCE AND LOW-TO-MID LEVEL ISENTROPIC
LIFT NOW. 305K-310K ISENTROPIC LIFT FORECASTS FROM THE 18Z NAM OR
GFS SUGGEST IT SHOULD BE POURING EVERYWHERE! HOWEVER THE BROAD-SCALE
RADAR COMPOSITE SHOWS THE FORECAST PROBLEM FOR TONIGHT: WIDESPREAD
DEEP CONVECTION ACROSS THE FLORIDA PENINSULA AND OFFSHORE EAST OF
JAX IS PRODUCING DOWNSTREAM MID-LEVEL WARMING AND DRYING THAT IS
NEGATIVELY IMPACTING PRECIPITATION COVERAGE ACROSS SOUTH GEORGIA AND
THE CAROLINAS. THIS IS A CLASSIC PROBLEM WE SEE LOCALLY DURING THE
COOL SEASON THAT HAS FRANKLY NEVER BEEN HANDLED WELL BY THE SYNOPTIC
MODELS.
BOTH THE HRRR AND HRRRX (AN EXPERIMENTAL VERSION AVAILABLE ON THE
RAPIDREFRESH.NOAA.GOV SERVER) ARE INITIALIZING WITH THE CORRECT
"HOLE" IN THE PRECIPITATION SHIELD AND SHOW THIS ANOMALY MAY
CONTINUE TO PLAGUE THE REGION`S RAINFALL FORECAST THROUGH THE NIGHT.
THE 18Z SYNOPTIC RAINFALL GUIDANCE FROM WPC ALSO SEEMS TO AGREE WITH
THIS IDEA OF LESSER RAINFALL TOTALS THAN ORIGINALLY THOUGHT. WITH
THIS IN MIND I HAVE KEPT FORECAST POPS AT 100% (EVERYONE WILL GET AT
LEAST 0.01 INCHES OF RAIN) BUT I HAVE TRIMMED BACK FORECAST RAINFALL
AMOUNTS SUBSTANTIALLY. FROM RIGHT NOW THROUGH THE END OF THE EVENT
LATE WEDNESDAY MORNING IT APPEARS TOTALS SHOULD AVERAGE HALF OF AN
INCH...PERHAPS APPROACHING AN INCH ALONG THE COAST IF RAINFALL RATES
CAN INCREASE TOWARD THE END OF THE EVENT WEDNESDAY MORNING.
OVER THE PAST FEW DAYS SYNOPTIC GUIDANCE HAS TRENDED FARTHER WEST
WITH THE FORECAST PATH OF THE LOW MOVING NORTH FROM FLORIDA. 18Z
MODELS CONTINUED THIS TREND AND I HAVE SHIFTED THE IMPLIED TRACK OF
THE LOW IN THE FORECAST WIND GRIDS TO ONLY ABOUT 10 MILES EAST OF
CAPE FEAR LATE TONIGHT. THIS WILL HAVE THE ADDED IMPACT OF
MAINTAINING A WARMER AIRMASS NEAR THE COAST...PARTICULARLY SE NORTH
CAROLINA...AND I HAVE RAISED FORECAST LOWS BY SEVERAL DEGREES HERE.
FARTHER INLAND THE COLD AIR SHOULD BEGIN TO BLEED IN FROM THE NW
SHORTLY AND VERY FEW CHANGES WERE NEEDED TO THE OVERALL TEMP/WIND
FORECAST.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...LOW PRESSURE HUGGING THE COAST WILL BE MOVING
N OF THE WATERS WEDNESDAY MORNING. AS THE LOW MOVES UP THE NORTH
CAROLINA AND MID ATLANTIC COAST WED...THE RAIN WILL SHUT OFF FROM
SSW TO NNE. PERIODS OF HEAVY RAIN ARE STILL POSSIBLE WED
MORNING...BUT EXPECT BY AFTERNOON...THE RISK FOR RAINFALL WILL HAVE
ENDED ACROSS ALL BUT THE CAPE FEAR AREA WHERE A SLIGHT RISK OF
AFTERNOON RAIN WILL STILL BE POSSIBLE. WILL INCLUDE CATEGORICAL POPS
WED MORNING THROUGHOUT. CONVECTION IS EXPECTED TO STAY OFFSHORE...
EAST OF THE LOW CENTER WHERE THERE WILL BE AN INFLUX OF WARMER AND
MORE UNSTABLE AIR.
ONE VERY POTENT MID-LEVEL SHORTWAVE TROUGH WILL PIVOT ACROSS THE
FORECAST AREA WED AFTERNOON WHILE ANOTHER SKIRTS OUR FORECAST AREA
TO THE N LATE WED NIGHT AND THU MORNING BEFORE LIFTING OUT. THE
INFLUX OF COLDER AND DRIER AIR WORKING INTO THE EASTERN CAROLINAS ON
THE BACKSIDE OF FIRST SHORTWAVE WILL HELP TO SIGNIFICANTLY DRY THE
COLUMN WITH PRECIPITABLE WATER VALUES DROPPING TO LESS THAN HALF AN
INCH. THIS WILL HELP TO PROMOTE DECREASING AFTERNOON CLOUDINESS...
ESPECIALLY ACROSS SOUTHERN AND WESTERN ZONES. THE SECOND SHORTWAVE
MAY ACTUALLY BRING A BRIEF INCREASE IN CLOUD COVER...BUT
PRECIPITATION IS EXPECTED TO REMAIN TO OUR N.
TEMPS ON WED WILL NOT MOVE MUCH AS COLD AIR ADVECTION GETS UNDERWAY.
IN FACT HIGHS WILL BE ACHIEVED IN MANY CASES PRIOR TO OR AROUND
SUNRISE. WE EXPECT HIGHS TO BE IN THE LOWER TO MID 50S ON THE COAST
WITH UPPER 40S TO AROUND 50 FROM EYF TO HYW AND POINTS W. DAYTIME
TEMPS WILL HOLD STEADY OF NOT DROP A DEGREE OR TWO. TEMPS WED NIGHT
WILL DROP INTO THE 30S TO AROUND 40. EVEN THE COLDEST SPOTS SHOULD
NOT REACH THE FREEZING MARK GIVEN THE LACK OF RADIATIONAL COOLING.
CHILLY HIGH PRESSURE WORKING TO THE COAST FROM THE W WILL ALLOW THE
PRESSURE GRADIENT TO LOOSEN THU NIGHT. THE COOLEST TEMPS AT 850 MB
THU WILL BE OFFSET BY SUNSHINE AND WE DO EXPECT HIGHS TO STILL REACH
THE MID 50S. RADIATIONAL COOLING WILL DEVELOP THU NIGHT WHICH SHOULD
ALLOW LOWS TO DROP INTO THE UPPER 20S TO LOWER 30S OVERNIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...LONG TERM PERIOD WILL REMAIN DRY WITH MID
LEVEL FLOW BECOMING PROGRESSIVE. COLD ADVECTION WILL BE WINDING DOWN
FRI...BUT TEMPS STILL END UP WELL BELOW CLIMO. DEEP WESTERLY FLOW
WILL BE QUICK TO SHIFT THE CENTER OF THE MODIFYING HIGH OFF THE
COAST WITH RETURN FLOW DEVELOPING SAT. TEMPS REMAIN BELOW CLIMO SAT
BUT WILL BE WARMER THAN FRI. EARLY NEXT WEEK 5H RIDGE TRIES TO BUILD
NORTH FROM THE EASTERN GOMEX AND FL. BUILDING HEIGHTS AND INCREASING
SOUTHWEST FLOW EARLY NEXT WEEK WILL PUSH TEMPS ABOVE CLIMO. BACKDOOR
COLD FRONT DEPICTED IN MEDIUM RANGE GUIDANCE YESTERDAY NOW LOOKS
TIMED TO CROSS THE AREA TUE MORNING...WITH BOTH GFS/ECMWF IN DECENT
AGREEMENT. FRONT WILL PASS DRY FOLLOWED BY WEAK COLD ADVECTION WITH
TEMPS DROPPING BACK NEAR CLIMO.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
AS OF 00Z...EXPECT VFR/MVFR CONDITIONS EARLY THIS EVENING TO
DETERIORATE TO IFR AS RAIN CONTINUES THROUGH THE OVERNIGHT HOURS. A
SHALLOW LAYER OF LIGHT NORTHEAST WINDS BEHIND THE FRONT WILL HELP TO
PROMOTE IFR STRATUS AS MOISTURE IS TRAPPED BENEATH A LOW-LEVEL
INVERSION. MEANWHILE...A DEVELOPING AREA OF LOW PRESSURE ALONG THE
FRONT WILL MOVE UP THE SOUTHEAST COAST OVERNIGHT... BRINGING MORE
PERSISTENT RAIN THAT MAY LOWER VSBYS TO MVFR/IFR LEVELS AT TIMES.
LIGHT NORTHEAST WINDS WILL BECOME MORE NORTHERLY AFTER MIDNIGHT...
AND THEN NORTHWEST BY 12Z ON THE BACK SIDE OF THE LOW AS IT MOVES UP
THE MID-ATLANTIC COAST. THE ENHANCED GRADIENT WILL RESULT IN GUSTY
NORTHWEST WINDS 15-20 KT DURING THE MORNING/EARLY AFTN HOURS.
CONDITIONS WILL IMPROVE FROM SW TO NE ACROSS OUR AREA DURING THE
AFTN AS THE LOW RACES AWAY AND DRIER AIR IS PULLED INTO THE
CAROLINAS. RAIN SHOULD END BY 18Z AS MVFR CIGS GRADUALLY IMPROVE TO
VFR BY THE END OF THE PERIOD.
EXTENDED OUTLOOK...VFR CONDITIONS EXPECTED THURSDAY THROUGH SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 700 PM TUESDAY...THE CAROLINA COASTAL WATERS ARE IN A LULL
CURRENTLY AS LOW PRESSURE DEVELOPS ALONG A FRONT STALLED ACROSS THE
FLORIDA PENINSULA. THIS FRONT EXTENDS NORTHEASTWARD TO VERY NEAR
CAPE FEAR WHICH EXPLAINS THE WEAK PRESSURE GRADIENT WE SEE ON
SURFACE CHARTS. AS THE NIGHT PROGRESSES THE LOW SHOULD FOLLOW THE
FRONT NORTH-NORTHEASTWARD...GRADUALLY DEEPENING AND PASSING JUST
EAST OF CAPE FEAR BEFORE DAYBREAK WEDNESDAY MORNING. WITH THE FRONT
REMAINING JUST OFF THE COAST WE SHOULD NOT SEE VERY STRONG WINDS
ACROSS THE COASTAL WATERS TONIGHT...15 KNOTS OR LESS THROUGH EARLY
WEDNESDAY MORNING. THE EXCEPTION TO THIS MAY BE ACROSS THE WATERS
10-20 MILES EAST OF CAPE FEAR WHERE STRONG SOUTH WINDS DEVELOPING
AROUND MIDNIGHT AHEAD OF THE INTENSIFYING LOW COULD REACH 25 KNOTS.
CERTAINLY OFFSHORE BEYOND 20 MILES WINDS ARE GOING TO INTENSIFY
QUITE A BIT OVER THE NEXT 6 HOURS AHEAD OF THE LOW. THIS WILL BE
IMPORTANT SINCE SEAS WILL BUILD QUITE SUBSTANTIALLY OFFSHORE...AND A
GOOD DEAL OF SOUTHERLY SWELL ENERGY SHOULD PROPAGATE INTO THE
COASTAL WATERS BEGINNING LATE THIS EVENING. FOR THIS REASON THE
SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT FOR THESE 4-6 FOOT SEAS
DEVELOPING AFTER MIDNIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...SMALL CRAFT ADVISORY CONDITIONS WILL CONTINUE
THROUGH THE DAY WED. WE DO THINK THESE CONDITIONS MAY WANE WED EVE.
HOWEVER...IT IS POSSIBLE THAT SMALL CRAFT ADVISORY CONDITIONS
REDEVELOP FOR A TIME LATE WED NIGHT AND THU AS BACKSWELL FROM
COASTAL LOW PRESSURE WELL NORTH OF THE AREA WORKS DOWN THE COAST.
ALSO...THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE TO OUR W AND
COASTAL LOW WILL HELP TO INCREASE LOW-LEVEL WIND SPEEDS AS SURGE OF
COLDEST AIR ARRIVES ACROSS THE WATERS. THE WIND DIRECTION WILL BE NW
OR TRANSITIONING TO NW WED MORNING AS THE LOW MOVES FURTHER UP THE
COAST. THE DIRECTION WILL THEN BACK TO A MORE WESTERLY DIRECTION WED
NIGHT AND THU. AS HIGH PRESSURE TO THE W BEGINS TO ASSERT ITSELF
LATE THU AND THU NIGHT...THE WIND DIRECTION WILL VEER TO NW AND THEN
N. HIGHEST WIND SPEEDS THIS PERIOD WILL BE UP TO 20 TO 25 KT AND
SEAS UP TO 5 TO 8 FT.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...DECREASING NORTHWEST FLOW ON FRI WILL BECOME
LIGHT AND VARIABLE FRI NIGHT INTO SAT AS SURFACE RIDGE AXIS MOVES
OVERHEAD. LIGHT SOUTHERLY FLOW DEVELOPS SAT AFTERNOON AS THE
CENTER OF THE HIGH PUSHES EAST OF THE WATERS. GRADIENT BECOMES A
LITTLE MORE DEFINED LATER SAT WITH SOUTHWEST FLOW INCREASING TO 10
TO 15 KT SAT NIGHT AND SUN. SEAS 2 TO 4 FT FRI MORNING DROP TO 2
TO 3 FT FRI NIGHT AND 2 FT OR LESS SAT AND SUN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 7 PM EST
WEDNESDAY FOR AMZ250-252-254-256.
&&
$$
NEAR TERM...TRA
SHORT TERM...RJD
LONG TERM...III
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1255 AM EST MON NOV 24 2014
.SYNOPSIS...
MILD TEMPERATURES WITH UNSETTLED WEATHER IS EXPECTED TONIGHT INTO
MONDAY AS A WARM FRONT CROSSES THE AREA. A COLD FRONT WILL CROSS
THE COAST MONDAY NIGHT AND STALL OFFSHORE TUESDAY. COOL AND WET
CONDITIONS ARE EXPECTED WEDNESDAY...AS DEEPENING LOW PRESSURE
MOVES NORTH ALONG THE STALLED FRONT AND SKIRTS THE COAST. SKIES
WILL CLEAR OUT ON THANKSGIVING...WITH TEMPERATURES RUNNING SEVERAL
DEGREES BELOW NORMAL INTO THE COMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1 AM MONDAY...LINE OF STRONG CONVECTION HAS MOVED OFFSHORE
AND OTHER THAN A FEW LIGHT SHOWERS IT LOOKS LIKE WE ARE IN FOR A
LULL IN THE ACTION FOR THE REMAINDER OF THE OVERNIGHT PERIOD. HAVE
UPDATED FORECAST ACCORDINGLY. PREVIOUS DISCUSSION FOLLOWS:
TWO CONVECTIVE BANDS ARE CROSSING THE AREA CURRENTLY AND SHOULD
DROP A GENERAL 0.4 TO 0.5 INCHES OF RAIN WITH EMBEDDED HEAVIER
AMOUNTS. AT THE SURFACE THE WARM FRONT APPEARS TO BE THROUGH
FLORENCE AND IS APPROACHING MYRTLE BEACH. LATEST HIGH- RES
MODELING INDICATES THE BOUNDARY SHOULD MOVE OR JUMP NORTHWARD VERY
QUICKLY WITH ALL OF OUR FORECAST AREA WITHIN THE WARM SECTOR BY
MIDNIGHT.
CONCERNING SEVERE WEATHER POTENTIAL...INSTABILITY REMAINS THE
LIMITING FACTOR. IN ORDER FOR CONVECTION TO BECOME SURFACE-BASED
ANALYSIS OF THE 03Z SOUNDINGS FROM THE 23Z RUC INDICATES WE NEED A
SURFACE TEMP/DEWPOINT OF 69 DEGREES F...EQUIVALENT TO A SURFACE
THETA-E VALUE OF 333K. ANYTHING LESS THAN THIS SHIFTS THE CONVECTIVE
ORIGIN POINT UPWARD OFF THE SURFACE WITH A CORRESPONDING REDUCTION
IN SEVERE WEATHER RISK. 02/03Z SURFACE OBS INDICATE WE DO NOT HAVE
REQUISITE THETA-E VALUES IN PLACE AT THE SURFACE TO SUPPORT
SURFACE-BASED CONVECTION...AND THEREFORE ALL OF THE CURRENT ACTIVITY
LIKELY REMAINS ELEVATED. THE DRY SLOT IS APPROACHING FROM THE WEST
AND SHOULD SPELL AN END TO THE SOLID PRECIPITATION SHIELD OVER THE
NEXT FEW HOURS...WITH ONLY SCATTERED SHOWERS CONTINUING LATE TONIGHT
INTO MONDAY MORNING. PREVIOUS DISCUSSION FROM 645 PM FOLLOWS...
A WAVE OF HEAVY SHOWERS AND EMBEDDED THUNDERSTORMS ACROSS EASTERN
GEORGIA AND NOW CROSSING THE SANTEE RIVER INTO SOUTH CAROLINA WILL
MOVE ACROSS THE EASTERN CAROLINAS SHORTLY. RAINFALL EARLIER TODAY
WAS MAINLY DUE TO ISENTROPIC UPGLIDE AS MOIST WARM ADVECTION WITHIN
THE 850-700 MB LAYER PRODUCED GENTLE UNIFORM LIFT. THE BATCH OF
PRECIPITATION TO BEGIN SHORTLY IS BEING FORCED BY EXCELLENT UPPER
DIVERGENCE WITHIN THE RIGHT-ENTRANCE REGION OF A 250 MB JET STREAK
MOVING NORTH THROUGH WESTERN NC/VA THIS EVENING.
A WARM FRONT CURRENTLY EXTENDING FROM NEAR BEAUFORT SC WESTWARD
ACROSS AUGUSTA GA WILL MOVE NORTHWARD AT A GOOD CLIP OVER THE NEXT
FEW HOURS...BRINGING A NEARLY TROPICAL AIRMASS NORTHWARD ACROSS THE
AREA. MODEST SURFACE BASED INSTABILITY ON THE ORDER OF 300-600 J/KG
SHOULD DEVELOP ACROSS AREAS WHERE TEMP/DEWPOINTS ARE ABLE TO REACH
70 DEGREES F. WHEN COMBINED WITH 0-1 KM HELICITY VALUES OF 400-600
M^2/S^2 THE POTENTIAL EXISTS FOR SOME OF THESE CELLS TO ROTATE. I
FEEL THE OVERALL SEVERE WEATHER RISK REMAINS LOW SINCE SURFACE-BASED
INSTABILITY SHOULD NOT DEVELOP UNTIL THE WARM FRONT ARRIVES AND
WINDS BELOW 925 MB VEER MORE SOUTHWESTERLY. THIS WILL MAKE THE
VERTICAL WIND PROFILE UNIDIRECTIONAL REDUCING THE POTENTIAL FOR
TORNADIC STORMS. IF TEMPS/DEWPOINTS REMAIN BELOW 70 F MODEL FORECAST
SOUNDINGS INDICATE THE BOUNDARY LAYER WOULD BE STABLE WITH
CONVECTION REMAINING ELEVATED AND THEREFORE INHERENTLY LESS
DANGEROUS. WE WILL MONITOR RADAR CLOSELY THROUGH THE EVENING
WATCHING FOR ANYTHING THAT MIGHT WARRANT A STATEMENT OR SEVERE
WEATHER WARNING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
AS OF 4 PM SUNDAY...ODDLY MILD CONDITIONS TO ENGULF THE EASTERN
CAROLINAS MONDAY WITH STRONG WARM AIR ADVECTION PATTERN IN PLACE
AND A COLD FRONT AND UPPER TROUGH WEST OF THE FORECAST AREA. 65-70
TEMPERATURE RANGE TO GREET MOST AREAS DAYBREAK MONDAY...AS MAXIMUM
TEMPERATURES CLIMB INTO THE MIDDLE AND UPPER 70S...LIKELY UNDER A
CANOPY OF CLOUDS DUE TO EXTENT OF UPSTREAM CONVECTION. THE LOW-LVL
WIND FIELD REMAINS STRONG MONDAY...AND ANY SURFACE HEATING MONDAY
AFTERNOON COULD LEAD TO CONVECTION CAPABLE OF DAMAGING WIND...AND
EVEN SHOWERS WILL BRING LOCALLY STRONGER GUSTS. SPC MAINTAIN A LOW
END RISK NEAR THE COAST AHEAD OF A COLD FRONT.
TUESDAY A POST-FRONTAL DAY WHERE WEATHER HAZARDS WANE. THE UPSTREAM
TROUGH ALIGN HOWEVER WILL SUPPORT MORE IMPULSES RISING OUT OF THE
GULF. CYCLOGENESIS OFFSHORE OF NORTHERN FLORIDA OCCUR VERY LATE IN
THE PERIOD AND BECOME A WEATHER PLAYER BEYOND DAYBREAK WEDNESDAY AND
POP VALUES DO GRADUALLY RAMP UP TO THIS FEATURE LATE TUESDAY.
RECORD HIGH TEMPS MONDAY ARE ILM 79...FLO 83...CRE 76...LBT 78.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 4 PM SUNDAY...MAIN FOCUS FOR THE PERIOD REMAINS LOW PRESSURE
PASSING JUST OFF THE COAST WED. SHORTWAVE CROSSING THE WESTERN GULF
LATE TUE WILL ENHANCE SURFACE WAVE JUST OFF THE FL GULF COAST WED
MORNING. THIS LOW WILL TRAVEL NORTHEAST ALONG A STALLED BOUNDARY WED
INTO WED NIGHT WITH DEEP MOISTURE SPREADING OVER THE CAROLINAS. LOW
WILL REMAIN EAST OF THE COASTAL WATERS WITH INCREASING NORTHERLY
FLOW...CLOUD COVER...AND PERIODS OF HEAVY RAIN KEEPING TEMPERATURES
IN THE 40S FOR MUCH OF THE AREA. PRESENCE OF DEEP MOISTURE AND
STRONG LIFT/DIVERGENCE ALOFT WILL ENSURE PLENTY OF RAIN FALLS ACROSS
THE AREA WED. MID LEVEL TROUGH MOVES INTO THE AREA WED EVENING WITH
SIGNIFICANT AMOUNT OF DRY AIR MOVING IN...ENDING THE RAIN THREAT.
SUBTLE MID LEVEL TROUGHING IN THE WAKE OF THE EXITING SYSTEM REMAINS
OVER THE SOUTHEAST FRI...PUSHING A DRY COLD FRONT ACROSS THE AREA.
MID LEVEL PATTERN FLATTENS OUT FOR THE WEEKEND AND FLOW ALOFT
BECOMES PROGRESSIVE. HIGH PRESSURE BUILDING IN FOR THE WEEKEND
QUICKLY SHIFTS OFFSHORE WITH RETURN FLOW DEVELOPING AND TEMPS
CLIMBING BACK CLOSE TO CLIMO.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...A MIXTURE OF MVFR/IFR/POSSIBLE LIFR WILL PERSIST THROUGH
THE VALID TAF PERIOD AS LOW CIGS AND FOG AFFECT THE AREA.
THE REMAINDER OF THE RAINFALL CONTINUES TO PUSH EASTWARD ACROSS THE
AREA...TAPERING OF WEST TO EAST. HOWEVER...WILL CONTINUE TO SEE
DETERIORATED CONDITIONS AS LOW CIGS AND FOG PERSISTS CREATING
MVFR/IFR ALONG WITH PERIODS OF LIFR POSSIBLE. AFTER DAYBREAK...WITH
GUSTY SOUTHWEST WINDS...LOW CIGS WITH AREAS OF FOG WILL PERSIST
THROUGH MUCH OF THE DAY...THUS EXPECT MVFR/IFR. COULD SEE BRIEF
IMPROVEMENT TO VFR IN SOME LOCATIONS...BUT OVERALL EXPECT MVFR/IFR.
ISOLATED -SHRA ARE POSSIBLE THROUGHOUT THE DAY..
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AFTERNOON
THROUGH WEDNESDAY NEAR THE COAST...WITH OCCASIONAL SHOWERS AND
MVFR/IFR CONDITIONS. BECOMING VFR WEDNESDAY NIGHT...THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1 AM MONDAY...SMALL CRAFT ADVISORY IN EFFECT ALTHOUGH ALL
STRONG CONVECTION HAS MOVED EAST OF THE WATERS. FORECAST UPDATED
ACCORDINGLY. PREVIOUS DISCUSSION FROM 10 PM FOLLOWS:
THE WARM FRONT APPEARS TO BE APPROACHING THE MYRTLE BEACH VICINITY
AS WINDS HAVE SHIFTED IN GEORGETOWN BUT SOUTHEAST WINDS CONTINUE IN
MYRTLE BEACH AND POINTS NORTHWARD ALONG THE COAST. GUSTS OUT AT THE
FRYING PAN SHOALS BUOY REMAIN ABOVE GALE-FORCE...AND WINDS AT THE
BEACHES NORTH OF CAPE FEAR ARE APPROACHING GALE FORCE WITH 33 KNOTS
RECENTLY REPORTED ON TOPSAIL ISLAND (MESONET) AND 30 KNOTS AT MERCER
PIER ON WRIGHTSVILLE BEACH. SEAS ARE ALMOST FULLY DEVELOPED FOR THIS
FETCH AND SPEED...13 FEET OUT AT FRYING PAN SHOALS...10 FEET AT THE
HARBOR BUOY SOUTH OF BALD HEAD ISLAND...AND 9 FEET AT THE NEARSHORE
WRIGHTSVILLE BEACH BUOY. NO SIGNIFICANT CHANGES ARE NEEDED FOR THIS
LATE-EVENING UPDATE. PREVIOUS DISCUSSION FROM 645 PM FOLLOWS...
THE WARM FRONT HAS MOVED THROUGH SAVANNAH AND IS RACING UP THE COAST
AT A PRETTY GOOD CLIP. MOST RECENT MODELS ARE TOO FAST WITH THE
FRONTAL TIMING...BUT AMONG THOSE THAT SEEM TO HAVE A GOOD HANDLE
(21Z HRRR, 22Z RUC, 12Z ECMWF) THE LATEST THINKING IS FOR FRONT TO
CROSS THE SANTEE RIVER 8-9 PM...CAPE FEAR AROUND 11 PM...AND TO BE
NORTH OF TOPSAIL ISLAND BY MIDNIGHT. THE FRONT WILL BE HERALDED BY A
SHIFT FROM SOUTHEAST TO SOUTH WINDS. ANOTHER HEAVY WAVE OF SHOWERS
AND EMBEDDED THUNDERSTORMS IN EASTERN GEORGIA AND NOW CROSSING THE
SAVANNAH RIVER INTO SOUTH CAROLINA SHOULD ARRIVE IN THE NEXT COUPLE
OF HOURS. HEAVY RAINFALL AND LIGHTNING ARE THE LARGEST THREATS.
WINDS HAVE BEEN GUSTING OVER GALE FORCE AT THE FRYING PAN SHOALS
BUOY FOR THE PAST THREE HOURS. BUOY 41004 EAST OF CHARLESTON IS IN
THE SAME ENVIRONMENT AND HAS ALSO GUSTED OVER GALE FORCE EARLY THIS
EVENING. CLOSER TO SHORE THE COLDER OCEAN WATER TEMPERATURE ON THE
SHALLOW CONTINENTAL SHELF IS INDUCED A MUCH MORE STABLE ATMOSPHERIC
BOUNDARY LAYER WITH LESS WIND ABLE TO MIX DOWN FROM ALOFT. DESPITE
WINDS JUST 1000 FEET ABOVE THE SURFACE EXPECTED TO REACH 50 KNOTS
IN JUST A COUPLE HOURS...WIND SPEEDS DOWN AT THE OCEAN SURFACE
SHOULD REMAIN 20-30 KNOTS ACROSS THE SC WATERS...AND 25-35 KNOTS
ACROSS THE NC WATERS WITH A HIGHER GUSTS WELL AWAY FROM SHORE WHERE
WATER TEMPERATURES ARE STILL IN THE RELATIVELY MILD MID 60S.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 4 PM SUNDAY...MONDAY MARINE CONDITIONS REMAIN DANGEROUS WITH
SEAS OF 5-9 FEET LIKELY AND HIGHEST AWAY FROM SHORE AND NEAR THE
FRYING PAN SHOALS. 20-30 KT SSW WINDS MONDAY...BECOMING WEST LATE
TUESDAY NIGHT OR EARLY MONDAY AS A SURFACE COLD FRONT MOVES ACROSS
THE WATERS. STRONG TSTMS REMAIN POSSIBLE MONDAY THROUGH TUESDAY
MORNING ON THE 0-20 NM WATERS. LARGE SSW-SE WAVES WILL MAKE UP THE
SEA SPECTRUM IN MIXED WAVE PERIODS OF 5-6 SECONDS AND 8-9 SECONDS.
IMPROVING CONDITIONS TUESDAY ALTHOUGH WAVE RECOVERY WILL STILL BE
UNDERWAY EARLY TUESDAY.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 4 PM SUNDAY...PERIOD OF HEADLINES SEEMS LIKELY WED INTO
WED NIGHT AS DEEPENING LOW PRESSURE PASSES JUST EAST OF THE
WATERS. WINDS WILL BACK FROM NORTH-NORTHEAST TO WEST WED INTO WED
NIGHT AS THE LOW LIFTS NORTHEAST. SPEEDS WILL PEAK IN THE 20 TO 25
KT RANGE WITH SEAS NEAR 20 NM FLIRTING WITH 6 TO 7 FT. OFFSHORE
FLOW WEAKENS LATE WED NIGHT INTO THU AS SURFACE HIGH TO THE WEST
BUILDS EAST. SPEEDS REMAIN CLOSE TO 15 KT THU WITH A SLIGHT
INCREASE FRI AS DRY COLD FRONT PASSES AND BRIEF COLD ADVECTION
DEVELOPS. AN OFFSHORE COMPONENT WILL KEEP SEAS WITHIN 20 NM IN THE
2 TO 4 FT RANGE THU AND FRI.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR AMZ250-252-254-
256.
&&
$$
SYNOPSIS...MJC
NEAR TERM...REK/TRA/MBB
SHORT TERM...MJC
LONG TERM...III
AVIATION...SGL
MARINE...MJC/REK/TRA/III/MBB
AREA FORECAST DISCUSSION...UPDATED
NWS WILMINGTON NC
1158 PM EST SUN NOV 23 2014
.SYNOPSIS...
MILD TEMPERATURES WITH UNSETTLED WEATHER IS EXPECTED TONIGHT INTO
MONDAY AS A WARM FRONT CROSSES THE AREA. A COLD FRONT WILL CROSS
THE COAST MONDAY NIGHT AND STALL OFFSHORE TUESDAY. COOL AND WET
CONDITIONS ARE EXPECTED WEDNESDAY...AS DEEPENING LOW PRESSURE MOVES
NORTH ALONG THE STALLED FRONT AND SKIRTS THE COAST. SKIES WILL
CLEAR OUT ON THANKSGIVING...WITH TEMPERATURES RUNNING SEVERAL
DEGREES BELOW NORMAL INTO THE COMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1000 PM SUNDAY...TWO CONVECTIVE BANDS ARE CROSSING THE AREA
CURRENTLY AND SHOULD DROP A GENERAL 0.4 TO 0.5 INCHES OF RAIN WITH
EMBEDDED HEAVIER AMOUNTS. AT THE SURFACE THE WARM FRONT APPEARS TO
BE THROUGH FLORENCE AND IS APPROACHING MYRTLE BEACH. LATEST HIGH-RES
MODELING INDICATES THE BOUNDARY SHOULD MOVE OR JUMP NORTHWARD VERY
QUICKLY WITH ALL OF OUR FORECAST AREA WITHIN THE WARM SECTOR BY
MIDNIGHT.
CONCERNING SEVERE WEATHER POTENTIAL...INSTABILITY REMAINS THE
LIMITING FACTOR. IN ORDER FOR CONVECTION TO BECOME SURFACE-BASED
ANALYSIS OF THE 03Z SOUNDINGS FROM THE 23Z RUC INDICATES WE NEED A
SURFACE TEMP/DEWPOINT OF 69 DEGREES F...EQUIVALENT TO A SURFACE
THETA-E VALUE OF 333K. ANYTHING LESS THAN THIS SHIFTS THE CONVECTIVE
ORIGIN POINT UPWARD OFF THE SURFACE WITH A CORRESPONDING REDUCTION
IN SEVERE WEATHER RISK. 02/03Z SURFACE OBS INDICATE WE DO NOT HAVE
REQUISITE THETA-E VALUES IN PLACE AT THE SURFACE TO SUPPORT
SURFACE-BASED CONVECTION...AND THEREFORE ALL OF THE CURRENT ACTIVITY
LIKELY REMAINS ELEVATED. THE DRY SLOT IS APPROACHING FROM THE WEST
AND SHOULD SPELL AN END TO THE SOLID PRECIPITATION SHIELD OVER THE
NEXT FEW HOURS...WITH ONLY SCATTERED SHOWERS CONTINUING LATE TONIGHT
INTO MONDAY MORNING. PREVIOUS DISCUSSION FROM 645 PM FOLLOWS...
A WAVE OF HEAVY SHOWERS AND EMBEDDED THUNDERSTORMS ACROSS EASTERN
GEORGIA AND NOW CROSSING THE SANTEE RIVER INTO SOUTH CAROLINA WILL
MOVE ACROSS THE EASTERN CAROLINAS SHORTLY. RAINFALL EARLIER TODAY
WAS MAINLY DUE TO ISENTROPIC UPGLIDE AS MOIST WARM ADVECTION WITHIN
THE 850-700 MB LAYER PRODUCED GENTLE UNIFORM LIFT. THE BATCH OF
PRECIPITATION TO BEGIN SHORTLY IS BEING FORCED BY EXCELLENT UPPER
DIVERGENCE WITHIN THE RIGHT-ENTRANCE REGION OF A 250 MB JET STREAK
MOVING NORTH THROUGH WESTERN NC/VA THIS EVENING.
A WARM FRONT CURRENTLY EXTENDING FROM NEAR BEAUFORT SC WESTWARD
ACROSS AUGUSTA GA WILL MOVE NORTHWARD AT A GOOD CLIP OVER THE NEXT
FEW HOURS...BRINGING A NEARLY TROPICAL AIRMASS NORTHWARD ACROSS THE
AREA. MODEST SURFACE BASED INSTABILITY ON THE ORDER OF 300-600 J/KG
SHOULD DEVELOP ACROSS AREAS WHERE TEMP/DEWPOINTS ARE ABLE TO REACH
70 DEGREES F. WHEN COMBINED WITH 0-1 KM HELICITY VALUES OF 400-600
M^2/S^2 THE POTENTIAL EXISTS FOR SOME OF THESE CELLS TO ROTATE. I
FEEL THE OVERALL SEVERE WEATHER RISK REMAINS LOW SINCE SURFACE-BASED
INSTABILITY SHOULD NOT DEVELOP UNTIL THE WARM FRONT ARRIVES AND
WINDS BELOW 925 MB VEER MORE SOUTHWESTERLY. THIS WILL MAKE THE
VERTICAL WIND PROFILE UNIDIRECTIONAL REDUCING THE POTENTIAL FOR
TORNADIC STORMS. IF TEMPS/DEWPOINTS REMAIN BELOW 70 F MODEL FORECAST
SOUNDINGS INDICATE THE BOUNDARY LAYER WOULD BE STABLE WITH
CONVECTION REMAINING ELEVATED AND THEREFORE INHERENTLY LESS
DANGEROUS. WE WILL MONITOR RADAR CLOSELY THROUGH THE EVENING
WATCHING FOR ANYTHING THAT MIGHT WARRANT A STATEMENT OR SEVERE
WEATHER WARNING.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 4 PM SUNDAY...ODDLY MILD CONDITIONS TO ENGULF THE EASTERN
CAROLINAS MONDAY WITH STRONG WARM AIR ADVECTION PATTERN IN PLACE
AND A COLD FRONT AND UPPER TROUGH WEST OF THE FORECAST AREA. 65-70
TEMPERATURE RANGE TO GREET MOST AREAS DAYBREAK MONDAY...AS MAXIMUM
TEMPERATURES CLIMB INTO THE MIDDLE AND UPPER 70S...LIKELY UNDER A
CANOPY OF CLOUDS DUE TO EXTENT OF UPSTREAM CONVECTION. THE LOW-LVL
WIND FIELD REMAINS STRONG MONDAY...AND ANY SURFACE HEATING MONDAY
AFTERNOON COULD LEAD TO CONVECTION CAPABLE OF DAMAGING WIND...AND
EVEN SHOWERS WILL BRING LOCALLY STRONGER GUSTS. SPC MAINTAIN A LOW
END RISK NEAR THE COAST AHEAD OF A COLD FRONT.
TUESDAY A POST-FRONTAL DAY WHERE WEATHER HAZARDS WANE. THE UPSTREAM
TROUGH ALIGN HOWEVER WILL SUPPORT MORE IMPULSES RISING OUT OF THE
GULF. CYCLOGENESIS OFFSHORE OF NORTHERN FLORIDA OCCUR VERY LATE IN
THE PERIOD AND BECOME A WEATHER PLAYER BEYOND DAYBREAK WEDNESDAY AND
POP VALUES DO GRADUALLY RAMP UP TO THIS FEATURE LATE TUESDAY.
RECORD HIGH TEMPS MONDAY ARE ILM 79...FLO 83...CRE 76...LBT 78.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 4 PM SUNDAY...MAIN FOCUS FOR THE PERIOD REMAINS LOW PRESSURE
PASSING JUST OFF THE COAST WED. SHORTWAVE CROSSING THE WESTERN GULF
LATE TUE WILL ENHANCE SURFACE WAVE JUST OFF THE FL GULF COAST WED
MORNING. THIS LOW WILL TRAVEL NORTHEAST ALONG A STALLED BOUNDARY WED
INTO WED NIGHT WITH DEEP MOISTURE SPREADING OVER THE CAROLINAS. LOW
WILL REMAIN EAST OF THE COASTAL WATERS WITH INCREASING NORTHERLY
FLOW...CLOUD COVER...AND PERIODS OF HEAVY RAIN KEEPING TEMPERATURES
IN THE 40S FOR MUCH OF THE AREA. PRESENCE OF DEEP MOISTURE AND
STRONG LIFT/DIVERGENCE ALOFT WILL ENSURE PLENTY OF RAIN FALLS ACROSS
THE AREA WED. MID LEVEL TROUGH MOVES INTO THE AREA WED EVENING WITH
SIGNIFICANT AMOUNT OF DRY AIR MOVING IN...ENDING THE RAIN THREAT.
SUBTLE MID LEVEL TROUGHING IN THE WAKE OF THE EXITING SYSTEM REMAINS
OVER THE SOUTHEAST FRI...PUSHING A DRY COLD FRONT ACROSS THE AREA.
MID LEVEL PATTERN FLATTENS OUT FOR THE WEEKEND AND FLOW ALOFT
BECOMES PROGRESSIVE. HIGH PRESSURE BUILDING IN FOR THE WEEKEND
QUICKLY SHIFTS OFFSHORE WITH RETURN FLOW DEVELOPING AND TEMPS
CLIMBING BACK CLOSE TO CLIMO.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...A MIXTURE OF MVFR/IFR/POSSIBLE LIFR EXPECT TONIGHT AND
THROUGH THE OVERNIGHT HOURS AS UNSETTLED WEATHER ALLOWS FOR
SHRA/TSRA TO CREATE PERIODS OF HEAVY RAIN AND WIND...ALONG WITH LOW
CIGS AND FOG...TO AFFECT THE AREA. RAIN TAPERS OFF INTO THE EARLY
MORNING HOURS...THOUGH AREAS OF LOW CIGS AND FOG ARE ANTICIPATED
THROUGH THE PERIOD...WITH IMPROVEMENT TO VFR POSSIBLE INLAND DURING
THE AFTERNOON HOURS ON MONDAY.
LATEST RADAR IMAGERY DEPICTS LIGHT -SHRA MOVING ACROSS THE AREA THIS
EVENING WHILE OBS ARE REPORTING LOW CIGS AND AREAS OF FOG CREATING
MVFR/IFR AT ALL TAF SITES. WHILE ACTIVITY IS LIGHT NOW...SHOWERS AND
THUNDERSTORMS ARE POSSIBLE LATER TONIGHT INTO THE EARLY OVERNIGHT
HOURS...WITH ISOLATED SEVERE STORMS POSSIBLE. WITH ANY STRONGER
STORM COULD SEE HEAVY RAINFALL. AS FOR WINDS EXPECT SOUTHEASTERLY
AROUND 10 KTS WITH GUSTS UP TO 20 KTS...AND HIGHER GUSTS POSSIBLE IN
ANY TSRA. LATE OVERNIGHT...ANY SHRA/TSRA WILL TAPER OFF...BUT WILL
CONTINUING TO SEE DETERIORATED CONDITIONS AS LOW CIGS AND FOG
PERSISTS. WHILE LIFR CANNOT BE RULE OUT...OVERALL ANTICIPATE
MVFR/IFR. INTO MONDAY...WITH GUSTY SOUTHWEST WINDS...LOW CIGS WITH
AREAS OF FOG WILL PERSIST...THUS EXPECT MVFR/IFR. COULD SEE
IMPROVEMENT TO VFR IN THE AFTERNOON HOURS IN SPOTS...BUT TOWARDS THE
END OF THE PERIOD CONDITIONS WILL DETERIORATE BACK TO MVFR/IFR.
EXTENDED OUTLOOK...UNSETTLED WEATHER IS EXPECTED MONDAY AFTERNOON
THROUGH WEDNESDAY NEAR THE COAST...WITH OCCASIONAL SHOWERS AND
MVFR/IFR CONDITIONS. BECOMING VFR WEDNESDAY NIGHT...THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1158 PM SUNDAY...GALE WARNING IS EXPIRING AT MIDNIGHT FOR THE
NC WATERS...REPLACED BY A SMALL CRAFT ADVISORY. ANY RESIDUAL STRONG
WINDS WILL BE ASSOCIATED WITH CONVECTION AND WILL BE HANDLED BY
SPECIAL MARINE WARNINGS RATHER THAN SYNOPTIC GALE PRODUCTS. PREVIOUS
DISCUSSION FROM 1000 PM FOLLOWS...
THE WARM FRONT APPEARS TO BE APPROACHING THE MYRTLE BEACH VICINITY
AS WINDS HAVE SHIFTED IN GEORGETOWN BUT SOUTHEAST WINDS CONTINUE IN
MYRTLE BEACH AND POINTS NORTHWARD ALONG THE COAST. GUSTS OUT AT THE
FRYING PAN SHOALS BUOY REMAIN ABOVE GALE-FORCE...AND WINDS AT THE
BEACHES NORTH OF CAPE FEAR ARE APPROACHING GALE FORCE WITH 33 KNOTS
RECENTLY REPORTED ON TOPSAIL ISLAND (MESONET) AND 30 KNOTS AT MERCER
PIER ON WRIGHTSVILLE BEACH. SEAS ARE ALMOST FULLY DEVELOPED FOR THIS
FETCH AND SPEED...13 FEET OUT AT FRYING PAN SHOALS...10 FEET AT THE
HARBOR BUOY SOUTH OF BALD HEAD ISLAND...AND 9 FEET AT THE NEARSHORE
WRIGHTSVILLE BEACH BUOY. NO SIGNIFICANT CHANGES ARE NEEDED FOR THIS
LATE-EVENING UPDATE. PREVIOUS DISCUSSION FROM 645 PM FOLLOWS...
THE WARM FRONT HAS MOVED THROUGH SAVANNAH AND IS RACING UP THE COAST
AT A PRETTY GOOD CLIP. MOST RECENT MODELS ARE TOO FAST WITH THE
FRONTAL TIMING...BUT AMONG THOSE THAT SEEM TO HAVE A GOOD HANDLE
(21Z HRRR, 22Z RUC, 12Z ECMWF) THE LATEST THINKING IS FOR FRONT TO
CROSS THE SANTEE RIVER 8-9 PM...CAPE FEAR AROUND 11 PM...AND TO BE
NORTH OF TOPSAIL ISLAND BY MIDNIGHT. THE FRONT WILL BE HERALDED BY A
SHIFT FROM SOUTHEAST TO SOUTH WINDS. ANOTHER HEAVY WAVE OF SHOWERS
AND EMBEDDED THUNDERSTORMS IN EASTERN GEORGIA AND NOW CROSSING THE
SAVANNAH RIVER INTO SOUTH CAROLINA SHOULD ARRIVE IN THE NEXT COUPLE
OF HOURS. HEAVY RAINFALL AND LIGHTNING ARE THE LARGEST THREATS.
WINDS HAVE BEEN GUSTING OVER GALE FORCE AT THE FRYING PAN SHOALS
BUOY FOR THE PAST THREE HOURS. BUOY 41004 EAST OF CHARLESTON IS IN
THE SAME ENVIRONMENT AND HAS ALSO GUSTED OVER GALE FORCE EARLY THIS
EVENING. CLOSER TO SHORE THE COLDER OCEAN WATER TEMPERATURE ON THE
SHALLOW CONTINENTAL SHELF IS INDUCED A MUCH MORE STABLE ATMOSPHERIC
BOUNDARY LAYER WITH LESS WIND ABLE TO MIX DOWN FROM ALOFT. DESPITE
WINDS JUST 1000 FEET ABOVE THE SURFACE EXPECTED TO REACH 50 KNOTS
IN JUST A COUPLE HOURS...WIND SPEEDS DOWN AT THE OCEAN SURFACE
SHOULD REMAIN 20-30 KNOTS ACROSS THE SC WATERS...AND 25-35 KNOTS
ACROSS THE NC WATERS WITH A HIGHER GUSTS WELL AWAY FROM SHORE WHERE
WATER TEMPERATURES ARE STILL IN THE RELATIVELY MILD MID 60S.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 4 PM SUNDAY...MONDAY MARINE CONDITIONS REMAIN DANGEROUS WITH
SEAS OF 5-9 FEET LIKELY AND HIGHEST AWAY FROM SHORE AND NEAR THE
FRYING PAN SHOALS. 20-30 KT SSW WINDS MONDAY...BECOMING WEST LATE
TUESDAY NIGHT OR EARLY MONDAY AS A SURFACE COLD FRONT MOVES ACROSS
THE WATERS. STRONG TSTMS REMAIN POSSIBLE MONDAY THROUGH TUESDAY
MORNING ON THE 0-20 NM WATERS. LARGE SSW-SE WAVES WILL MAKE UP THE
SEA SPECTRUM IN MIXED WAVE PERIODS OF 5-6 SECONDS AND 8-9 SECONDS.
IMPROVING CONDITIONS TUESDAY ALTHOUGH WAVE RECOVERY WILL STILL BE
UNDERWAY EARLY TUESDAY.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 4 PM SUNDAY...PERIOD OF HEADLINES SEEMS LIKELY WED INTO
WED NIGHT AS DEEPENING LOW PRESSURE PASSES JUST EAST OF THE
WATERS. WINDS WILL BACK FROM NORTH-NORTHEAST TO WEST WED INTO WED
NIGHT AS THE LOW LIFTS NORTHEAST. SPEEDS WILL PEAK IN THE 20 TO 25
KT RANGE WITH SEAS NEAR 20 NM FLIRTING WITH 6 TO 7 FT. OFFSHORE
FLOW WEAKENS LATE WED NIGHT INTO THU AS SURFACE HIGH TO THE WEST
BUILDS EAST. SPEEDS REMAIN CLOSE TO 15 KT THU WITH A SLIGHT
INCREASE FRI AS DRY COLD FRONT PASSES AND BRIEF COLD ADVECTION
DEVELOPS. AN OFFSHORE COMPONENT WILL KEEP SEAS WITHIN 20 NM IN THE
2 TO 4 FT RANGE THU AND FRI.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR AMZ254-256.
SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR AMZ250-252.
&&
$$
SYNOPSIS...MJC/TRA
NEAR TERM...TRA
SHORT TERM...MJC
LONG TERM...III
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
113 PM EST MON NOV 24 2014
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP EAST ACROSS THE REGION TODAY...BRINGING
SHOWERS ALONG WITH WINDY CONDITIONS. MUCH COLDER AIR WILL RUSH IN
BEHIND THE FRONT AND WILL LINGER FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FCST FOCUS TODAY REVOLVES AROUND STRONG WINDS AND CONVECTION THIS
MORNING. STRONG SFC LOW OVER THE NRN GREAT TO CONTINUE TO DEEPEN
AS IT TRACKS NE INTO SRN CANADA. 60 KT SWRLY LLJ PIVOTING THRU
THE AREA TODAY. RAP SHOWING BLYR CAPE OF 350 J/KG ACRS W CENTRAL
OHIO EARLY THIS MORNING. THIS MARGINAL INSTBY AHD OF SFC COLD FRONT
COMBINED WITH THE STRONG DYNAMICS HAS LED TO THE DEVELOPMENT OF A
BROKEN LINE OF CONVECTION. SOME OF THE STORMS WERE TRANSLATING
WINDS UP TO 45 KTS TO THE SFC. AN ISOLATED SVR WIND GUST OF 50 KTS
OR GREATER IN A STRONGER STORM CAN NOT BE RULED OUT.
THIS MARGINAL INSTBY WEAKENS AND PIVOTS TO THE NE THIS MORNING.
CURRENT FCST HAS GOOD HANDLE TAKING THIS CHANCE OF THUNDER EAST
AND THEN DIMINISHING.
SFC PRESSURE GRADIENT TIGHTENS WITH FROPA IN STRONG CAA THIS
MORNING INTO EARLY AFTERNOON. 50 TO 60 KT LOW LEVEL WILL GET
PULLED DOWN IN THE POST FRONTAL COLD ADVECTION. HAVE INCREASED
SUSTAINED WINDS AND BUMPED UP GUSTS INTO THE UPPER 40 KT RANGE.
EXPECT WINDS TO BE IN THE HIGH END WIND ADVISORY RANGE. THEREFORE...
HAVE KEPT CURRENT WIND ADVISORY HEADLINE GOING.
AFTER MORNING HIGHS IN IN STRONG LOW LEVEL CAA EXPECT EARLY HIGHS
WITH TEMPERATURES FALLING TO LATE AFTN READINGS RANGING FROM THE LOWER
40S NW TO THE LOWER 50S SE. HAVE ADJUSTED AFTERNOON TEMPS A LTL COLDER
IN THIS CAA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
BY EVENING THE PRESSURE GRADIENT WILL BEGIN TO WEAKEN AND THE
WINDS WILL GRADUALLY SLOW DOWN. LEFT OVER WRAP AROUND SHOWERS WILL
CHANGE OVER TO SNOW AS THICKNESSES FALL. THERE SHOULDNT BE ANY
APPRECIABLE ACCUMULATIONS.
BY TUESDAY MORNING SURFACE HIGH PRESSURE WILL BEGIN TO BUILD IN
AND SHOULD PROVIDE DRY WEATHER...ALTHOUGH A FEW SNOW SHOWERS MAY
LINGER OVER FAR NORTHERN LOCATIONS.
ON TUESDAY NIGHT...THE REGION WILL BE IN BETWEEN SYSTEMS...AS
ENERGY IN THE SRN STREAM AFFECTS THE EAST COAST AND ANOTHER S/W IS
DIGGING DOWN THROUGH THE PLAINS. MODELS ARE SHOWING A WIDE RANGE
IN THE STRENGTH AND PATH OF THIS SYSTEM. RIGHT NOW THE CONSENSUS
IS THAT THE REGION WILL REMAIN DRY ON WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
FOCUS SHIFTS TO WEAKENING CLIPPER LOW DROPPING SE FROM THE UPPER
MS VLY WED AFTN THRU THE OHIO VALLEY WED NIGHT. NUMERICAL MODELS
HAVE BEEN FLIPPING BACK AND FORTH REGARDING HOW FAR SOUTH THIS
SYSTEM DIGS AND TIMING. LATEST DETERMINISTIC RUNS TAKING WEAK SFC
WAVE FROM CENTRAL IL LATE WED AFTN THRU THE TRI-STATE REGION WED
NIGHT. WILL BRING SNOW IN WED EVENING AND CONTINUE INTO THURSDAY.
SOME PCPN MIX WILL BE POSSIBLE ACRS THE SOUTHEAST. HIGHS ON
THURSDAY TO RANGE FROM THE LOWER/MID 30S NW TO LOWER 40 SE.
IN NORTHWEST FLOW AND CAA SOME LINGERING SNOW SHOWERS PSBL THURSDAY
NIGHT. SFC HIGH PRESSURE TO QUICKLY BUILD ACRS THE REGION EARLY ON
FRIDAY WITH A RETURN FLOW DEVELOPING BY AFTN. WAA PCPN TO DEVELOP
DURG THE AFTN WITH THE BULK OF PCPN STAYING TO OUR NORTH. WILL KEEP
AREA DRY THRU FRIDAY NIGHT. CONTD COLD TEMPERATURES WITH HIGHS ON
FRIDAY TO RANGING FROM THE LOWER 30S NW TO THE UPR 30S SE.
WAA PCPN LOOKS TO DEVELOP SAT AFTN BUT WITH MORE UNCERTAINTY
CREEPING INTO THE FCST REGARDING PLACEMENT/TIMING WILL LIMIT POPS TO
SLIGHT CHANCE OF SHOWERS. THE RAIN COULD MIX OR CHANGE TO SNOW SAT
NIGHT. GFS SOLN APPEARS TOO QUICK WITH COLD FRONTAL PASSAGE. WILL
TREND SOLN CLOSER TO SLOWER ECMWF WITH FRONT HOLDING OFF UNTIL EARLY
MONDAY. IN WAA SECTOR CHANCE OF SHOWERS WILL CONTINUE SUNDAY.
TEMPERATURES WILL MODERATE WITH HIGHS ON SUNDAY FROM UPPER 30S
NORTHWEST TO THE UPPER 40S SOUTH.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
MOST OF THE SHOWER ACTIVITY HAS MOVED OUT OF THE TAF SITES.
HANDLED ANY REMAINING LIGHT SHOWER ACTIVITY WITH A VCSH THIS
AFTERNOON. WINDS WILL CONTINUE TO BE GUSTY THROUGH THE EVENING
HOURS WITH THE GREATEST GUSTS THIS AFTERNOON. WIND GUSTS IN EXCESS
OF 30 TO 40 KNOTS WILL BE POSSIBLE DURING THIS TIME. SOME LESSER
WIND GUSTS WILL CONTINUE INTO TONIGHT BEFORE TAPERING OFF. MVFR
AND VFR CIGS ARE AROUND THE AREA THIS AFTERNOON. EXPECT VFR OR
MVFR CIGS THROUGH THE TAF PERIOD.
OUTLOOK...MVFR CIGS POSSIBLE INTO TUESDAY. MVFR CIGS/VSBYS POSSIBLE
WEDNESDAY NIGHT INTO THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR OHZ026-034-035-
042>046-051>056-060>065-070>074-077>082-088.
KY...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR KYZ089>100.
IN...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ050-058-059-
066-073>075-080.
&&
$$
SYNOPSIS...CONIGLIO/SITES
NEAR TERM...AR/SITES
SHORT TERM...SITES
LONG TERM...AR
AVIATION...NOVAK
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
941 AM EST MON NOV 24 2014
.SYNOPSIS...
A STRONG COLD FRONT WILL SWEEP EAST ACROSS THE REGION TODAY...BRINGING
SHOWERS ALONG WITH WINDY CONDITIONS. MUCH COLDER AIR WILL RUSH IN
BEHIND THE FRONT AND WILL LINGER FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FCST FOCUS TODAY REVOLVES AROUND STRONG WINDS AND CONVECTION THIS
MORNING. STRONG SFC LOW OVER THE NRN GREAT TO CONTINUE TO DEEPEN
AS IT TRACKS NE INTO SRN CANADA. 60 KT SWRLY LLJ PIVOTING THRU
THE AREA TODAY. RAP SHOWING BLYR CAPE OF 350 J/KG ACRS W CENTRAL
OHIO EARLY THIS MORNING. THIS MARGINAL INSTBY AHD OF SFC COLD FRONT
COMBINED WITH THE STRONG DYNAMICS HAS LED TO THE DEVELOPMENT OF A
BROKEN LINE OF CONVECTION. SOME OF THE STORMS WERE TRANSLATING
WINDS UP TO 45 KTS TO THE SFC. AN ISOLATED SVR WIND GUST OF 50 KTS
OR GREATER IN A STRONGER STORM CAN NOT BE RULED OUT.
THIS MARGINAL INSTBY WEAKENS AND PIVOTS TO THE NE THIS MORNING.
CURRENT FCST HAS GOOD HANDLE TAKING THIS CHANCE OF THUNDER EAST
AND THEN DIMINISHING.
SFC PRESSURE GRADIENT TIGHTENS WITH FROPA IN STRONG CAA THIS
MORNING INTO EARLY AFTERNOON. 50 TO 60 KT LOW LEVEL WILL GET
PULLED DOWN IN THE POST FRONTAL COLD ADVECTION. HAVE INCREASED
SUSTAINED WINDS AND BUMPED UP GUSTS INTO THE UPPER 40 KT RANGE.
EXPECT WINDS TO BE IN THE HIGH END WIND ADVISORY RANGE. THEREFORE...
HAVE KEPT CURRENT WIND ADVISORY HEADLINE GOING.
AFTER MORNING HIGHS IN IN STRONG LOW LEVEL CAA EXPECT EARLY HIGHS
WITH TEMPERATURES FALLING TO LATE AFTN READINGS RANGING FROM THE LOWER
40S NW TO THE LOWER 50S SE. HAVE ADJUSTED AFTERNOON TEMPS A LTL COLDER
IN THIS CAA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
BY EVENING THE PRESSURE GRADIENT WILL BEGIN TO WEAKEN AND THE
WINDS WILL GRADUALLY SLOW DOWN. LEFT OVER WRAP AROUND SHOWERS WILL
CHANGE OVER TO SNOW AS THICKNESSES FALL. THERE SHOULDNT BE ANY
APPRECIABLE ACCUMULATIONS.
BY TUESDAY MORNING SURFACE HIGH PRESSURE WILL BEGIN TO BUILD IN
AND SHOULD PROVIDE DRY WEATHER...ALTHOUGH A FEW SNOW SHOWERS MAY
LINGER OVER FAR NORTHERN LOCATIONS.
ON TUESDAY NIGHT...THE REGION WILL BE IN BETWEEN SYSTEMS...AS
ENERGY IN THE SRN STREAM AFFECTS THE EAST COAST AND ANOTHER S/W IS
DIGGING DOWN THROUGH THE PLAINS. MODELS ARE SHOWING A WIDE RANGE
IN THE STRENGTH AND PATH OF THIS SYSTEM. RIGHT NOW THE CONSENSUS
IS THAT THE REGION WILL REMAIN DRY ON WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
FOCUS SHIFTS TO WEAKENING CLIPPER LOW DROPPING SE FROM THE UPPER
MS VLY WED AFTN THRU THE OHIO VALLEY WED NIGHT. NUMERICAL MODELS
HAVE BEEN FLIPPING BACK AND FORTH REGARDING HOW FAR SOUTH THIS
SYSTEM DIGS AND TIMING. LATEST DETERMINISTIC RUNS TAKING WEAK SFC
WAVE FROM CENTRAL IL LATE WED AFTN THRU THE TRI-STATE REGION WED
NIGHT. WILL BRING SNOW IN WED EVENING AND CONTINUE INTO THURSDAY.
SOME PCPN MIX WILL BE POSSIBLE ACRS THE SOUTHEAST. HIGHS ON
THURSDAY TO RANGE FROM THE LOWER/MID 30S NW TO LOWER 40 SE.
IN NORTHWEST FLOW AND CAA SOME LINGERING SNOW SHOWERS PSBL THURSDAY
NIGHT. SFC HIGH PRESSURE TO QUICKLY BUILD ACRS THE REGION EARLY ON
FRIDAY WITH A RETURN FLOW DEVELOPING BY AFTN. WAA PCPN TO DEVELOP
DURG THE AFTN WITH THE BULK OF PCPN STAYING TO OUR NORTH. WILL KEEP
AREA DRY THRU FRIDAY NIGHT. CONTD COLD TEMPERATURES WITH HIGHS ON
FRIDAY TO RANGING FROM THE LOWER 30S NW TO THE UPR 30S SE.
WAA PCPN LOOKS TO DEVELOP SAT AFTN BUT WITH MORE UNCERTAINTY
CREEPING INTO THE FCST REGARDING PLACEMENT/TIMING WILL LIMIT POPS TO
SLIGHT CHANCE OF SHOWERS. THE RAIN COULD MIX OR CHANGE TO SNOW SAT
NIGHT. GFS SOLN APPEARS TOO QUICK WITH COLD FRONTAL PASSAGE. WILL
TREND SOLN CLOSER TO SLOWER ECMWF WITH FRONT HOLDING OFF UNTIL EARLY
MONDAY. IN WAA SECTOR CHANCE OF SHOWERS WILL CONTINUE SUNDAY.
TEMPERATURES WILL MODERATE WITH HIGHS ON SUNDAY FROM UPPER 30S
NORTHWEST TO THE UPPER 40S SOUTH.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
CONVECTIVE BAND OF SHOWERS OVER CENTRAL INDIANA MAY SKIRT KDAY FOR
A PERIOD OF TIME THIS MORNING SO CHANGED VCSH TO VCTS AND HAVE AN
HOUR OF TEMPO TS HERE. REMAINING TAF SITES WILL LIKELY NOT GET
INTO THE DEEP CONVECTION AS THIS AREA IS SLATED TO MOVE NORTHEAST
FROM DAYTON AREA AS THE LARGE SCALE FORCING LIFTS NORTHEAST WITH
THE EJECTING LOW PRESSURE CENTER.
MVFR CIGS WILL BE PREVALENT IN THE 2-3KFT RANGE INTO TONIGHT WITH
SOME BREAKUP NOTED AWAY FROM KDAY AFTER ABOUT 5 OR 6. A TRAILING
EDGE OF THE SURFACE TROUGH AND CONTINUED PLACEMENT OF A VORT AXIS
AT H5 OVER THE AREA WOULD HAVE LOW STRATOCU CONTINUE AT KDAY BUT
NOT NEARLY AS LIKELY DURING THE OVERNIGHT HOURS ELSEWHERE. WINDS
WILL ALSO EXHIBIT A MARKED DECREASE TONIGHT.
OUTLOOK...MVFR CIGS POSSIBLE INTO TUESDAY. MVFR CIGS/VSBYS POSSIBLE
WEDNESDAY NIGHT INTO THURSDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR OHZ026-034-035-
042>046-051>056-060>065-070>074-077>082-088.
KY...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR KYZ089>100.
IN...WIND ADVISORY UNTIL 10 PM EST THIS EVENING FOR INZ050-058-059-
066-073>075-080.
&&
$$
SYNOPSIS...CONIGLIO/SITES
NEAR TERM...AR/SITES
SHORT TERM...SITES
LONG TERM...AR
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1146 PM EST SUN NOV 23 2014
.SYNOPSIS...
DEEPENING LOW PRESSURE WILL TRACK FROM THE LOWER MISSISSIPPI
VALLEY ACROSS THE GREAT LAKES ON MONDAY PUSHING A STRONG COLD
FRONT ACROSS THE AREA ON MONDAY WITH A SECOND COLD FRONT ON
TUESDAY. A WEAK LOW PRESSURE AREA AND A COLD FRONT WILL CROSS THE
LOWER GREAT LAKES LATER WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
WINDS WILL INCREASE OVERNIGHT AS LOW PRESSURE CONTINUES TO DEEPEN
AS IT TRACKS NORTH THROUGH THE CENTRAL GREAT LAKES. A WIND
ADVISORY REMAINS IN EFFECT FOR THE NORTHEAST LAKESHORE WITH THE
STRONGEST WINDS EXPECTED ACROSS NORTHERN ERIE PA COUNTY NEAR THE LAKESHORE.
THE HRRR SHOWS WINDS PEAKING BY ABOUT 2 AM IN THIS AREA THEN
DECREASING LATE TONIGHT AS THE WARM FRONT PASSES TO THE NORTH. EXPECT
THE STRONG WIND IN THE OTHER ADVISORY AREAS TO BE SOMEWHAT MORE
LOCALIZED WHERE DOWNSLOPING IS ENHANCED OFF THE HIGHER TERRAIN
AND SOME HELP FROM SHORELINE CONVERGENCE. WE HAVE ALREADY HAD A
WIND GUST TO 47 MPH AT LPR AND 41 MPH AT MFD. THESE FEW STRAY
GUSTS ABOVE 40 MPH ARE POSSIBLE OVERNIGHT BUT THINKING THEY WILL
STAY LIMITED ENOUGH TO NOT NEED TO EXPAND THE ADVISORY FOR THE
OVERNIGHT HOURS.
AS FOR THE HIGH WIND WATCH FOR MONDAY...A CORRIDOR OF THE
STRONGEST WINDS IS EXPECTED ACROSS NORTHWEST AND NORTH CENTRAL
OHIO BEHIND THE FRONT WHERE GUSTS OF 50-60 MPH ARE POSSIBLE.
ELSEWHERE IT LOOKS LIKE THE PEAK GUSTS MAY ONLY OCCUR WITH SHOWERS
SO COULD POSSIBLY BE HANDLED WITH A WIND ADVISORY AND SHORT FUSED CONVECTIVE
PRODUCTS IF NECESSARY. ALWAYS TOUGH THIS TIME OF YEAR TO DECIDE
BETWEEN SVR WARNINGS AND HIGH WIND WARNINGS. FEW CHANGES MADE WITH
THE UPDATE.
PREVIOUS DISCUSSION...RAIN SHOULD SPREAD ACROSS THE AREA TONIGHT
AS THE MAIN SHORT WAVE LIFTS OUT. THE SOUTH SOUTHEAST DOWN SLOPE
WIND LESSEN THE RAIN TO SOME EXTENT ACROSS NORTHEAST OHIO AND
NORTHWEST PENNSYLVANIA BUT EVERYONE SHOULD SEE A PERIOD OF
RAIN/SHOWERS.
THE LOW LEVEL JET IS PROGGED TO INCREASE DRAMATICALLY TONIGHT...
INCREASING TO 70-80 KNOTS. DOES NOT GET MUCH STRONGER THAN THAT. THE
WARM AIR ALOFT AND THE RAIN SHOULD DO A GOOD JOB AT KEEPING THE
LOWER LAYERS STABLE. THE MIXED LAYER IS PROGGED TO REMAIN RELATIVELY
SHALLOW TONIGHT...ONLY ABOUT 1K. WE CAN PROBABLY KEEP THE SOUTH
DOWN SLOPE WINDS IN CHECK. THAT BEING SAID...WE CAN STILL TAP
30-35 KNOT WINDS EVEN WITH THE STABLE CONDITIONS. CANNOT RULE OUT
THAT ROGUE 40 KNOT GUST SOMEWHERE BUT IN GENERAL WE SHOULD BE ABLE
TO STAY UNDER THE WIND ADVISORY/WARNING CRITERIA TONIGHT. THE
EXCEPTION WOULD BE ALONG THE EAST LAKESHORE FROM EAST OF MENTOR
THROUGH ERIE COUNTY PA. WILL NEED TO HAVE AN ADVISORY THERE
STARTING ABOUT 10 PM. JUST A LITTLE TOO EASY WITH THE DOWN SLOPE
COMPLIMENT TO GET TO 40 KNOTS OR MORE ESPECIALLY IN ERIE COUNTY PA.
TEMPS MAY DROP A FEW DEGREES WITH THE ONSET OF THE RAIN OTHERWISE
WITH THE STRONG SOUTH FLOW AND RISING DEWPOINTS...TEMPERATURES
WILL BE STEADY OR RISE TONIGHT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
WIND WILL BE THE CONCERN ON MONDAY. WE START THE DAY WITH A 30-40
KNOTS AT 925 MB AND 60 KNOTS OR MORE AT 850 MB. AS STATED
ABOVE...THE RAIN WILL CREATE A RELATIVELY STABLE SITUATION IN THE
BOUNDARY LAYER EARLY ON...BUT THAT WILL ERODE ESPECIALLY WITH THE
ARRIVAL OF THE COLD FRONT. WE TYPICALLY CAN GET 60-70% MIXING IN
THIS TYPE OF SITUATION. THAT WOULD NECESSITATE A WIND ADVISORY...
WITH STRONG ISENTROPIC DESCENT AND LARGE PRESSURE RISES ARRIVING
(+6 TO +8 MB)...A SOUTHWEST WIND DIRECTION IN LINE WITH THE
MOMENTUM AND MOVEMENT OF THE SURFACE LOW....LITTLE LOW LEVEL SHEAR
AND THE POSSIBILITY OF A CONVECTIVE LINE OF SHOWERS WITH THE
FRONTAL PASSAGE...NOT TOO MENTION A FAVORABLE TIME OF DAY FOR
MAXIMUM MIXING...A WIND WARNING MAY BE NECESSARY. I WOULD FEEL
MORE CERTAIN IF THE COLD ADVECTION WAS STRONGER AND QUICKER. WILL
ISSUE A HIGH WIND WATCH AND KEEP THE OPTIONS OPEN FOR EITHER A
WIND ADVISORY OR A HIGH WIND WARNING FOR MONDAY AFTERNOON WITH THE
PASSAGE OF THE COLD FRONT...CONTINUING INTO THE EVENING.
WARM UNTIL THE FRONTAL PASSAGE ON MONDAY. HIGHS GENERALLY 55 TO
60 AHEAD OF THE FRONT.
SEASONABLY COLDER AIR WILL SWEEP IN BEHIND THE FRONT. TEMPERATURES
WILL LIKELY NOT DROP OFF TOO QUICKLY ON MONDAY AFTERNOON GIVEN
THE WELL MIXED NATURE OF THE AIR MASS AND THE CHANCE THAT A FEW
PEAKS OF SUNSHINE MIGHT DEVELOP. LOWS MONDAY NIGHT NEAR NORMAL IN
THE UPPER 20S/LOWER 30S.
THE FLOW WILL BE SOUTHWEST ON TUESDAY. NOT MUCH LAKE INFLUENCE
EXCEPT PERHAPS FROM ASHTABULA TO ERIE WHERE SOME SNOW
SHOWERS/FLURRIES MIGHT CLIP THE LAKESHORE. THE STRATOCUMULUS WILL
INCREASE DIURNALLY DURING THE DAY...PARTLY TO MOSTLY CLOUDY. HIGHS
IN THE 30S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MODELS CONTINUE WITH A COASTAL LOW OFF THE MID ATLANTIC COAST
WEDNESDAY EVENING...THEN DEEPENING AND TRACKING INTO NEWFOUNDLAND
THANKSGIVING DAY. TROUGH WILL REMAIN OVER THE EASTERN LAKES THROUGH
THURSDAY NIGHT. BEST MOISTURE IN THE WEST SO KEPT LIKELY POPS
ACROSS THE EASTERN CWA. COLDER AIR BEHIND THE CLIPPER DROPS THE
850MB TEMPS OVER LAKE ERIE TO -14C BY THURSDAY EVENING SO LAKE
EFFECT SNOW LIKELY...PRIMARILY IN THE SNOWBELT THURSDAY NIGHT. HIGH
PRESSURE MOVES OVER THE AREA FRIDAY CHOCKING OF LINGERING LAKE
EFFECT.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
A WARM FRONT OVER THE OHIO VALLEY WILL MOVE NORTH OVERNIGHT AND AS
THIS HAPPENS THE SHOWERS WILL DECREASE FROM THE SOUTH. A BREAK
WILL OCCUR IN THE WARM SECTOR ON MONDAY ESPECIALLY OVER NE OH AND
NW PA AND THEN A STRONG COLD FRONT WILL MOVE THROUGH. SOME SHOWERS
AND MAY BE EVEN AN ISOLATED THUNDERSTORM MAY OCCUR WITH THE
FRONTAL PASSAGE.
GUSTY SOUTHEAST TO SOUTH WINDS WILL OCCUR AT TIMES TONIGHT AS THE
LOW MOVES FROM THE MIDWEST TO THE UPPER PENINSULA OF MICHIGAN.
ON MONDAY AS THE BAND OF SHOWERS MOVES THROUGH STRONG WINDS WILL
BE ASSOCIATED WITH THE FRONT AND BEHIND IT IN THE COLD ADVECTION.
.OUTLOOK...NON VFR TUESDAY AND THEN AGAIN WEDNESDAY NIGHT INTO
THURSDAY IN SNOW.
&&
.MARINE...
ISSUED LOW WATER ADVISORY BEGINNING MONDAY AFTERNOON AND
CONTINUING INTO TUESDAY AFTERNOON. WATER LEVELS COULD GET AS LOW
AS 4 FEET BELOW LOW WATER DATUM. THE STRONG GALE FORCE SOUTHWEST
FLOW WILL CAUSE THIS.
PREVIOUS DISCUSSION...
ISSUED GALE WARNING FOR LAKE ERIE BEGINNING
MONDAY MORNING. MODELS CONTINUE TO DEEPEN THE OKLAHOMA LOW NORTH
OVER LAKE MICHIGAN TONIGHT LIFTING A WARM FRONT ACROSS THE LAKE.
BY DAYBREAK THE THE 925MB WINDS INCREASE TO 40-45 KNOTS...NOT SURE
HOW MUCH WILL MIX DOWN IN WAA PATTERN. STRONGEST WINDS EXPECTED
IMMEDIATELY AHEAD AND BEHIND THE ARCTIC FRONT. MODELS MOVE THE
FRONT ACROSS LAKE ERIE DURING MONDAY AFTERNOON. EXPECT 40 KNOT
GALES...BUT 45 KNOT GALES NOT OUT OF THE QUESTION. THIS STRONG
SOUTHWEST FLOW WILL CREATE A LOW WATER SITUATION FOR THE WESTERN
BASIN. WINDS ARE EXPECTED TO REMAIN AT GALE FORCE INTO TUESDAY
MORNING...THEN SLOWLY DIMINISH TUESDAY NIGHT.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...WIND ADVISORY UNTIL NOON EST MONDAY FOR OHZ012-089.
HIGH WIND WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR OHZ011>014-020>023-031>033-038-089.
HIGH WIND WATCH FROM 10 AM EST MONDAY THROUGH MONDAY EVENING
FOR OHZ003-006>010-017>019-027>030-036-037-047.
PA...WIND ADVISORY UNTIL NOON EST MONDAY FOR PAZ001-002.
HIGH WIND WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING
FOR PAZ001>003.
MARINE...GALE WARNING FROM 9 AM MONDAY TO 4 PM EST TUESDAY FOR LEZ061-
145>149-165>169.
LOW WATER ADVISORY FROM 3 PM MONDAY TO 4 PM EST TUESDAY FOR
LEZ142>144-162>164.
GALE WARNING FROM 9 AM MONDAY TO 10 AM EST TUESDAY FOR
LEZ142>144-162>164.
&&
$$
SYNOPSIS...KOSARIK
NEAR TERM...KEC/KOSARIK
SHORT TERM...KOSARIK
LONG TERM...DJB
AVIATION...KIELTYKA
MARINE...DJB/KIELTYKA
AREA FORECAST DISCUSSION
NWS MEDFORD OR
950 AM PST MON NOV 24 2014
.DISCUSSION...CURRENT VISIBLE IMAGE SHOWS SCATTERED HIGH CLOUDS
OVER THE EASTERN PART OF THE REGION AND LOW CLOUDS IN THE VALLEYS.
MORE CLOUDS FROM AN APPROACHING WARM FRONT ARE OFFSHORE AND ARE
EXPECTED TO MOVE INLAND LATER THIS MORNING. THE NAM AND RAP ARE IN
GOOD AGREEMENT HOLDING OFF ANY WARM FRONTAL PRECIPITATION UNTIL
LATE IN THE AFTERNOON AND MOST CONFINED TO WEST OF THE CASCADES.
THUS HAVE TRIMMED BACK POPS FOR THIS MORNING AND AFTERNOON TO
BETTER REFLECT THE TIMING. QPF AMOUNTS TODAY SHOULD ALSO BE
LIGHT. EVEN THE COAST RANGE AND CASCADES WILL PROBABLY GET LESS
THAN A TENTH OF AN INCH BY THIS EVENING. THE WARM FRONT WILL MOVE
THROUGH THIS EVENING AND BRING A BETTER CHANCE OF LIGHT STEADY
PRECIPITATION MAINLY NORTH OF HIGHWAY 140 AND NORTH OF THE UMPQUA
DIVIDE. -PETRUCELLI
&&
.AVIATION...IFR CIGS/VIS REMAIN IN THE ILLINOIS, ROGUE AND
SISKIYOU COUNTY VALLEYS AND IT COULD REMAIN THAT WAY THROUGH EARLY
AFTERNOON BEFORE BREAKING OUT. EVEN THEN IT MAY ONLY BE FOR A
BRIEF TIME. ELSEWHERE VFR CONDITIONS ARE EXPECTED THROUGH THIS
AFTERNOON. MVFR AND LOCAL IFR CIGS RETURN WITH MOUNTAIN
OBSCUATIONS THIS EVENING AND TONIGHT AS A WARM FRONT MOVES INTO
THE AREA. EAST OF THE CASCADES...VFR CONDITIONS WILL CONTINUE
INTO TONIGHT, BUT THERE IS A CHANCE FOR LOW CLOUDS AND FOG TO
DEVELOP IN SOME OF THE BASINS, INCLUDING KLMT. -PETRUCELLI
&&
.MARINE...UPDATED 5 AM PST SUN NOV 23 2014...A WARM FRONT WILL MOVE
OVER THE WATERS THIS AFTERNOON INTO EARLY THIS EVENING. STEEP
MODERATE WEST SWELL WILL SLOWLY SUBSIDE TODAY...BUT THE FRONT WILL
BRING SMALL CRAFT WINDS TO THE AREA THIS AFTERNOON INTO EARLY THIS
EVENING. SO...SEAS WILL REMAIN STEEP WITH CHOPPY SEAS DEVELOPING
TODAY. WINDS AND SEAS WILL BOTH SUBSIDE TONIGHT. OFFSHORE HIGH
PRESSURE WILL REBUILD TUESDAY AND WEAKEN WEDNESDAY. A COLD FRONT
WILL MOVE ACROSS THE WATERS WEDNESDAY NIGHT INTO THURSDAY...FOLLOWED
BY ANOTHER ONE FRIDAY. /CC
&&
.PREV DISCUSSION... /ISSUED 333 AM PST MON NOV 24 2014/
DISCUSSION...
FOR THANKSGIVING TRAVELERS, WE EXPECT SOME LIGHT PRECIPITATION
TODAY THROUGH TUESDAY, WITH NO SNOWY ROADS EXCEPT POSSIBLY A
DUSTING IN THE DIAMOND AND CRATER LAKE AREAS THIS AFTERNOON.
AFTER A DRY BREAK WEDNESDAY, WE EXPECT WETTER WEATHER TO ARRIVE
BEGINNING THANKSGIVING DAY AND THEN PERSISTING THROUGH NEXT
WEEKEND INTO EARLY NEXT WEEK. SNOW LEVELS ARE LIKELY TO REMAIN
ABOVE MAJOR MOUNTAIN PASS ROADWAYS THROUGH EARLY NEXT SUNDAY, BUT
THEN MAY START COMING DOWN. SNOW IMPACTS LOOK POSSIBLE PER THE
LATEST NUMERICAL MODEL GUIDANCE NEXT SUNDAY NIGHT INTO EARLY NEXT
WEEK.
THE SNOW DEPTH AT CRATER LAKE NATIONAL PARK HEADQUARTERS
YESTERDAY MORNING WAS REPORTED TO BE 22 INCHES, WHICH IS 91.6% OF
THE 1931-2000 HISTORICAL AVERAGE. OVER THE NEXT WEEK WE ARE
EXPECTING A WARMING TREND THAT IS LIKELY TO CONSOLIDATE THE SNOW
ON THE GROUND ACROSS THE MOUNTAINS. A COOLER PERIOD IS EXPECTED
TO BEGIN AGAIN SOMETIME LATE NEXT WEEKEND TO EARLY NEXT WEEK TIME
FRAME WITH SNOW ACCUMULATION LIKELY.
TODAY THROUGH TUESDAY WARM AIR WILL OVERRUN THE COOLER AIR MASS IN
PLACE RESULTING IN PLENTY OF CLOUD COVER AND SOME LIGHT
PRECIPITATION. MODELS VARY QUITE A BIT ON AMOUNTS, EXTENT, AND
DURATION, BUT EXPECT MOST OF THE PRECIPITATION TO BE IN THE OREGON
CASCADES, COAST RANGE, COAST, AND UMPQUA BASIN. THESE AREAS MAY
GET A TENTH TO A QUARTER OF AN INCH OF WATER, BUT MOST AREAS WILL
SEE A FEW HUNDREDTHS TO A TRACE OF RAIN.
TUESDAY THROUGH THURSDAY WARM AIR ALOFT WILL DEVELOP AN INVERSION
OVER THE VALLEYS. HOW WARM IT WILL GET IN THE VALLEYS WILL DEPEND
ON HOW COOL IT GETS THE NIGHT BEFORE, WHICH WILL BE MODULATED BY
CLOUD COVER AND WIND. AS TIME GOES BY, THE NEXT STORM SYSTEM IN
THE PACIFIC WILL BEGIN TO DRAW AIR INTO IT RESULTING IN SOUTH AND
EAST WINDS ACROSS THE AREA THAT ARE LIKELY TO DISRUPT AND
EVENTUALLY MIX OUT VALLEY INVERSIONS. THIS SHOULD YIELD SOME
HIGHS IN THE 55-65F RANGE FOR MOST VALLEYS, WHICH IS 5-15F ABOVE
NORMAL.
THANKSGIVING DAY THROUGH THE WEEKEND WE EXPECT RAIN TO DEVELOP AS
A FRONTAL SYSTEM ARRIVES, SLOWS, STALLS, AND THEN PROGRESSES
THROUGH THE AREA. THIS WILL RESULT IN HIGH SNOW LEVELS WITH
INCREASINGLY WET WEATHER ACROSS THE REGION. THIS IS LIKELY TO
TRANSITION TO A COOLER AND WETTER PATTERN AROUND THE LATE SUNDAY-
MONDAY TIME FRAME, WHEN SNOW LEVELS MAY REACH DOWN TO SOME OF THE
PRIMARY MOUNTAIN PASSES AND POSSIBLY THE EAST SIDE, AT TIMES. BTL
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 7 PM PST THIS EVENING FOR
PZZ350-356-370-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST THIS
EVENING FOR PZZ350-356-370-376.
$$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
414 AM EST MON NOV 24 2014
.SYNOPSIS...
NEAR-RECORD WARM TEMPERATURES ARE EXPECTED OVER MUCH OF THE AREA
TODAY...BEFORE COLD AIR ARRIVES TONIGHT BEHIND A DEPARTING LOW
PRESSURE SYSTEM. ANOTHER AREA OF LOW PRESSURE WILL MOVE ALONG THE
MID ATLANTIC COAST WEDNESDAY INTO THURSDAY... BRINGING A CHANCE OF
SIGNIFICANT SNOW TO THE EASTERN HALF OF PENNSYLVANIA. ANOTHER
SHOT OF COLD AIR WILL FOLLOW FOR NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
STEADY OR SLOWLY RISING TEMPERATURES ARE THE NORM THIS MORNING AS
WARM FRONT LIFTS ACROSS CENTRAL PA. STEADIEST AND HEAVIEST RAINFALL
HAS STREAKED NORTH AND EAST OF MY AREA AT THIS TIME ON THE NOSE OF
A 55-65KT 850 MB JET LIFTING INTO NY STATE. LIGHTER SHOWERS STILL
TRAVERSING THE HIGHER TERRAIN OF WESTERN PA AS WELL AS THE LOWER
SUSQ RIVER VALLEY...BUT THESE WILL DECREASE LATER THIS MORNING
AS THE WARM FRONT CONTINUES TO LIFT NORTH UPSTATE NY.
SHORT TERM CONCERN IS FOR STRONG GUSTY WINDS ACROSS THE HIGHER
ELEVS OF THE ALLEGHENIES LATER TODAY. STRONGLY COUPLED SOUTHWEST
WINDS SHOULD EASILY CREATE IN THE UPPER 30KT RANGE...LIKELY
INCREASING TO OCNLY 40-43 KTS IN THE LATE AFTERNOON AND NIGHT.
WIND ADVISORY REMAINS IN EFFECT 17Z-09Z TUESDAY FOR THE NW MTNS
AND LAUREL HIGHLANDS.
CLEARING AND STRONG MIXING WILL PUSH AFTERNOON TEMPS TO NEAR-
RECORD LEVELS. THE BIGGEST TEMP BUST POTENTIAL AREA /STAY TOO
COOL VS FCST/ WILL BE THE NORTHEASTERN MTNS. COLD FRONT TIMED TO
CROSS THE REGION LATE THIS AFTERNOON AND EVENING...BUT COOLING
WILL NOT BE SHARP AS DEEP NEARLY PARALLEL FLOW PROMOTES ONLY SLOW
SOUTHEAST PROGRESSION OF POST FRONTAL AIR MASS. AFTER A ROUND OF
EVENING SHOWERS...EXPECT THE REMAINDER OF TONIGHT TO BE DRY AS
COLD ADVECTION PERSISTS ON WSW FLOW. MINS WILL NOT BE VERY COLD...
ONLY RANGING FROM AROUND 30F NORTH TO THE LOWER 40S SOUTHEAST.
&&
.SHORT TERM /TUESDAY/...
BOUNDARY LAYER FLOW WILL SLOWLY BACK AND WEAKEN ON TUESDAY...WHILE A
WEAK AREA OF HIGH PRESSURE DRIFTS INTO THE OHIO VALLEY AND INTO
THE WRN PA TUESDAY NIGHT. TUESDAY WILL BE THE CALM BEFORE THE
STORM AS ALL EYES SHIFT SOUTHWARD FOR THE EVOLUTION OF WHAT COULD
BE THE FIRST WIDESPREAD SIGNIFICANT SNOWFALL ACROSS MUCH OF THE
EASTERN HALF OF CENTRAL PA WEDNESDAY.
COLD AIR WILL CONTINUE TO FILTER IN ALOFT...AND HIGHS TUESDAY WILL
BE SOME 20 DEGREES COOLER THAN THE NEAR RECORD READINGS OF MONDAY
AFTERNOON.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
POTENTIAL FOR SIG WINTER IMPACTS FROM LOW PRESSURE MOVING UP THE
EAST COAST ON WED/WED NIGHT. WILL CONTINUE TO INJECT
INTERPRETATION OF THE LATEST MODEL GUIDANCE WITH EACH 3-HOURLY
UPDATE TO GUIDE DECISION SUPPORT LEADING UP TO THE PRIME TRAVEL
PERIOD FOR THE THANKSGIVING HOLIDAY.
HIGHLY AMPLIFIED AND ACTIVE UPPER AIR PATTERN WILL BRING A PERIOD
OF ACTIVE WEATHER THROUGH THE COMING WEEK. THE 500MB CONFIGURATION
WILL FEATURE ANOMALOUS RIDGING ALONG THE WEST COAST AND IN THE
WESTERN ATLANTIC WITH A FULL-LATITUDE PERSISTENT TROUGH EBBING
AND FLOWING OVER THE CENTRAL AND EASTERN U.S.
AFTER THE EXIT OF MONDAY/S LOW PRESSURE AREA...COLDER TEMPS
RETURN ON BRISK W/SW FLOW FOR TUE DROPPING HIGHS SOME 20-25F FROM
PREV DAYS READINGS. WE/LL ALSO SEE THE RETURN OF LIGHT SNOW
SHOWERS IN THE WESTERN HIGHER TERRAIN.
THEN FOCUS WILL TURN TO A WAVE CURRENTLY DROPPING SE FROM BRITISH
COLUMBIA AND WASHINGTON STATE...WHICH WILL SPAWN AN AREA OF LOW
PRESSURE OVER THE SE US TUESDAY NIGHT...THAT WILL LIKELY MOVE
NORTH NORTHEASTWARD JUST OFF THE EAST COAST WEDNESDAY INTO
THURSDAY.
12Z/18Z OPERATIONAL AND GEFS RUNS ALONG WITH THE 21Z SREF ARE
BECOMING FAIRLY WELL CLUSTERED WITH RESPECT TO THE LOCATION OF THE
NEAR...TO SUB-1000 MB SFC LOW EARLY WED EVENING /NEAR...AND UP TO
ABOUT 200 NM EAST OF DELMARVA PENINSULA/.
THERE IS STILL MUCH UNCERTAINTY AT THIS 60-72 HOUR TIMEFRAME
BEFORE THE EVENT...WITH RESPECT TO THE EXACT TRACK OF THE SFC LOW
AND ASSOCIATED SNOW/RAIN AMOUNTS.
COLD AIR WILL BE IN PLACE WED MORNING AS A /WEAK/ HIGH PRESSURE
RIDGE RETREATS TO THE NORTH AHEAD OF THE APPROACHING LOW.
NORTHERLY FLOW OVER CENTRAL PA NOT PARTICULARLY STRONG IN ANY
MODEL...BUT A SHORTWAVE LOOKS POISED TO SLIDE IN FROM THE GREAT
LAKES ON WED TO ADD SOME SYNOPTIC LIFT TO A RAPIDLY DEEPENING AND
FAST MOVING SURFACE LOW.
THE 12Z ECMWF AND IT`S ENSEMBLE ARE VERY SIMILAR HUGGING THE SFC
LOW ALONG THE SHORELINE...WHILE US/CANADIAN MODELS AND THEIR
ENSEMBLES ARE FURTHER EAST BY 100-200 NM. EXPERIENCE SHOWS THAT
THE LACK OF A SIGNIFICANT BLOCKING HIGH TO OUR NORTH OR
NORTHEAST...FAVORS A MORE WESTERN TRACK /SIMILAR TO THE EC AND ITS
ENSEMBLE/. SHOULD THE WWD TREND CONTINUE EVEN FURTHER WITH AN
EARLIER INJECTION OF NRN STREAM ENERGY INTO THE SOUTHERN STREAM
SYSTEM...IT/S CONCEIVABLE THAT OUR FAR SE ZONES /NEAR KLNS AND
KMDT/ COULD EVEN SEE A MIX WITH SLEET AND RAIN FOR A PERIOD THAT
WOULD HOLD DOWN ACCUMULATIONS.
PRECIP MAY START OFF EARLY WED AS A MIX OF RAIN AND SNOW IN THE
SE...BUT COOLING TEMPS ALOFT SHOULD CONVERT ALL PRECIP OVER TO
SNOW BY MIDDAY. AS IS A GENERAL RULE WITH THESE TYPES OF EVENTS...
THERE WILL LIKELY BE A SHARP DROP OFF IN ACCUMULATIONS ON THE NW
EDGE OF THE HEAVIER SNOWS. BIGGEST POTENTIAL IMPACTS IN OUR CWA
WILL BE THE CENTRAL MTNS AND SUSQ VALLEY...WHERE POTENTIAL FOR A
SEVERAL HOUR PERIOD OF HEAVY ACCUMULATING SNOW WILL EXIST. BUT
AGAIN...SMALL CHANGES IN THE ULTIMATE TRACK COULD LEAD TO
MODIFICATIONS OF SNOWFALL FORECASTS. THE TAKE AWAY...THOUGH THE
DETAILS REMAIN UNCERTAIN...THERE WILL BE SIG IMPACTS TO TRAVEL
ALONG THE U.S. EAST COAST ON ONE OF THE BUSIEST DAYS OF THE YEAR
/WED/. PLAN ACCORDINGLY.
COLDER AIR REMAINS IN PLACE LATE IN THE WEEK AS SCT SNOW SHOWERS
RETURN TO THE WESTERN HIGHER TERRAIN. TEMPS LOOK TO GRADUALLY
MODIFY LATE WEEKEND HEADING INTO NEXT WEEK...WITH NO BIG STORM
SYSTEMS EXPECTED AFTER THANKSGIVING.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
A LOW PRESSURE SYSTEM TRACKING NORTHWARD INTO THE GRT LKS WILL
SPREAD LOWERING CIGS AND RAIN ACROSS CENTRAL PA TONIGHT. REGIONAL
RADAR AT 06Z SHOWS A DRY SLOT BEGINNING TO ENTER SOUTHWEST PA.
THIS WILL CAUSE CIGS AND VSBYS TO INCREASE...AND SHOULD LIFT
RESTRICTIONS SLOWLY. THE LOW LEVEL MOISTURE REMAINS HIGH AND
SOUTHERLY WINDS IN THE 1-2 KFT LAYER WILL BECOME VERY STRONG
OVERNIGHT...MAKING LLWS A NEAR CERTAINTY. SFC GUSTS OVERNIGHT WILL
BE HIGHEST AT KJST DUE TO IT/S RIDGETOP LOCATION. HRRR OUTPUT
SUGGESTS GUSTS BTWN 25-35KTS ARE POSSIBLE THERE UNTIL 09Z. MUCH
LIGHTER SFC WINDS EXPECTED ELSEWHERE...WHICH WILL LEAD TO THE
LLWS.
THE CONDITIONS LOOK TO IMPROVE QUICKER THAN PREVIOUSLY
MODELED...WHICH MEANS THE LOW CIGS AND LINGERING DRIZZLE WILL
GIVE WAY TO IMPROVING CONDS BY MID MONDAY AM...AS WARM FRONT
LIFTS NORTH OF THE REGION. GENERALLY VFR CONDS ARE ANTICIPATED
MONDAY AFTERNOON.
A COLD FRONT MOVING FROM THE WEST WILL BE ACCOMPANIED BY SCT LATE
DAY SHRA ACROSS THE W MTNS...POSSIBLY PRODUCING A BRIEF VSBY
REDUCTION AT KBFD OR KJST.
OUTLOOK...
TUE...NO SIG WX EXPECTED.
WED...SNOW/LOW VSBYS POSS EASTERN PA.
THU...-SHSN/REDUCED VSBYS POSS NW MTNS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 4 AM EST TUESDAY FOR
PAZ004>006-010-011-017-024-033.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...DEVOIR/RXR
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
110 AM EST MON NOV 24 2014
.SYNOPSIS...
STRONG LOW PRESSURE WILL PUSH NORTHWARD THROUGH THE GREAT LAKES
LATE TONIGHT AND MONDAY. IT WILL BRING A SLUG OF RAIN THROUGH THE
STATE TONIGHT. VERY WARM AND EVEN NEAR-RECORD WARM TEMPERATURES
ARE EXPECTED OVER MUCH OF THE AREA MONDAY...BEFORE THE COLD AIR
FOLLOWING THE GREAT LAKES LOW MOVES ACROSS LATE MONDAY AND MONDAY
NIGHT. A DEEPENING AREA OF LOW PRESSURE WILL MOVE NORTHWARD ALONG
THE MID ATLANTIC COAST WEDNESDAY. THERE IS A LOW CONFIDENCE AS TO
WHAT THE EXACT PATH OF THIS STORM WILL BE. HOWEVER...THE EASTERN
THIRD TO HALF OF THE STATE COULD HAVE A SIGNIFICANT SNOWFALL. COLD
AIR WILL FOLLOW FOR NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WARM FRONT LIFTING THROUGH THE VIRGINIAS EARLY THIS MORNING WITH
STRONG SOUTHERLY FLOW ALOFT. VIGOROUS UPPER TROF LIFTING THROUGH
CENTRAL AND EASTERN OHIO WITH WIDESPREAD LIGHT TO MODERATE RAIN
SHIELD EXTENDING FROM NORTHEAST OHIO THROUGH ALL BUT FAR SOUTHWEST
PA. BACK EDGE OF RAIN SHIELD MAKING STEADY PROGRESS NNE
AS PREVIOUSLY MENTIONED...FAST NORTHWARD PROPAGATION OF RAIN
PRECLUDES ANY CONCERNS FOR HEAVY RAIN. GENERAL 0.50 INCHES QPF IS
EXPECTED...BUT SOME HEAVIER AMOUNTS ARE POSSIBLE FAR SOUTHEAST
WHERE CONVECTIVE INSTABILITY IS PREVENT. KEPT MENTION OF T THERE
FOR THE OVERNIGHT.
WINDS ALOFT GET UP TO 50 KTS OVER THE CENTRAL MTNS...BUT THE
GENERAL STABILITY OVER THE BULK OF THE AREA SHOULD KEEP GUSTS DOWN
DURING THE NIGHT. THE EXCEPTION COULD BE THE HIGHER PEAKS IN THE
WEST WHICH COULD BE GUSTY /INTO THE 20 PLUS KT RANGE/ THROUGH THE
NIGHT. TEMPS WILL LIKELY LEVEL-OFF OR EVEN RISE LATER TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
SUBSIDENCE/DRYING IMMEDIATELY BEHIND THE OVERNIGHT WAVE WILL START
THE BREAK-UP OF THE CLOUDS FROM S-N. HOWEVER...THE AMBIENT
MOISTURE WILL BE HIGH IN THE LLVLS AND FLOW OUT OF THE SOUTH
THROUGH THE COLUMN WILL MAKE IT DIFFICULT TO CLEAR THE NORTHERN
HALF OF THE AREA TOO RAPIDLY. THE SOUTH WILL LIKELY GET SOME
DECENT CLEARING AND THE WARM AIR AHEAD OF THE COLD FRONT WILL PUSH
TEMPS TO NEAR-RECORD LEVELS ON MONDAY AFTERNOON. WILL KEEP THE
NUMBERS SLIGHTLY LOWER THAN RECORDS...THOUGH. THIS IS DUE TO THE
UNCERTAINTY OF HOW MUCH SUN TIME WE WILL HAVE. THE BIGGEST TEMP
BUST POTENTIAL AREA /STAY TOO COOL VS FCST/ WILL BE THE
NORTHEASTERN MTNS. THEY COULD STAY TOO CLOUDY. THE INSTABILITY
COULD ALSO TOUCH OFF A FEW SHOWERS -MAINLY IN THE CENTRAL AND
NORTH. THE COLD FRONT SHOULD MOVE THROUGH LATER IN THE DAY AND
EARLY EVENING.
THE WINDS WILL BE THE OTHER STORY - ALONG WITH THE TEMPS. THE
WESTERN MOUNTAINS/ALLEGHENIES WILL BE THE GUSTIEST PLACE. MIXED-
WINDS WITH LITTLE DIRECTIONAL SHEAR OFF BUFKIT SOUNDINGS MAKE FOR
WIND GUSTS EASILY INTO THE UPPER 30KT RANGE...LIKELY INCREASING TO
OCNLY 40-43 KTS IN THE LATE AFTERNOON AND NIGHT. A WIND ADVISORY
WAS RECENTLY ISSUED FOR 17Z MONDAY - 09Z TUESDAY FOR THE NW MTNS
AND LAUREL HIGHLANDS.
THE PERIOD OF LIKELY HIGHEST GUSTS APPEAR TO BE NEAR...AND FOR SEVERAL
HOURS IN THE WAKE OF THE CFROPA /OR FROM 21Z MONDAY TO 05Z
TUESDAY/.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
POTENTIAL FOR SIG WINTER IMPACTS FROM LOW PRESSURE MOVING UP THE
EAST COAST ON WED/WED NIGHT. WILL CONTINUE TO INJECT
INTERPRETATION OF THE LATEST MODEL GUIDANCE WITH EACH 3-HOURLY
UPDATE TO GUIDE DECISION SUPPORT LEADING UP TO THE PRIME TRAVEL
PERIOD FOR THE THANKSGIVING HOLIDAY.
HIGHLY AMPLIFIED AND ACTIVE UPPER AIR PATTERN WILL BRING A PERIOD
OF ACTIVE WEATHER THROUGH THE COMING WEEK. THE 500MB CONFIGURATION
WILL FEATURE ANOMALOUS RIDGING ALONG THE WEST COAST AND IN THE
WESTERN ATLANTIC WITH A FULL-LATITUDE PERSISTENT TROUGH EBBING
AND FLOWING OVER THE CENTRAL AND EASTERN U.S.
AFTER THE EXIT OF MONDAY/S LOW PRESSURE AREA...COLDER TEMPS
RETURN ON BRISK W/SW FLOW FOR TUE DROPPING HIGHS SOME 20-25F FROM
PREV DAYS READINGS. WE/LL ALSO SEE THE RETURN OF LIGHT SNOW
SHOWERS IN THE WESTERN HIGHER TERRAIN.
THEN FOCUS WILL TURN TO A WAVE CURRENTLY DROPPING SE FROM BRITISH
COLUMBIA AND WASHINGTON STATE...WHICH WILL SPAWN AN AREA OF LOW
PRESSURE OVER THE SE US TUESDAY NIGHT...THAT WILL LIKELY MOVE
NORTH NORTHEASTWARD JUST OFF THE EAST COAST WEDNESDAY INTO
THURSDAY.
12Z/18Z OPERATIONAL AND GEFS RUNS ALONG WITH THE 21Z SREF ARE
BECOMING FAIRLY WELL CLUSTERED WITH RESPECT TO THE LOCATION OF THE
NEAR...TO SUB-1000 MB SFC LOW EARLY WED EVENING /NEAR...AND UP TO
ABOUT 200 NM EAST OF DELMARVA PENINSULA/.
THERE IS STILL MUCH UNCERTAINTY AT THIS 60-72 HOUR TIMEFRAME
BEFORE THE EVENT...WITH RESPECT TO THE EXACT TRACK OF THE SFC LOW
AND ASSOCIATED SNOW/RAIN AMOUNTS.
COLD AIR WILL BE IN PLACE WED MORNING AS A /WEAK/ HIGH PRESSURE
RIDGE RETREATS TO THE NORTH AHEAD OF THE APPROACHING LOW.
NORTHERLY FLOW OVER CENTRAL PA NOT PARTICULARLY STRONG IN ANY
MODEL...BUT A SHORTWAVE LOOKS POISED TO SLIDE IN FROM THE GREAT
LAKES ON WED TO ADD SOME SYNOPTIC LIFT TO A RAPIDLY DEEPENING AND
FAST MOVING SURFACE LOW.
THE 12Z ECMWF AND IT`S ENSEMBLE ARE VERY SIMILAR HUGGING THE SFC
LOW ALONG THE SHORELINE...WHILE US/CANADIAN MODELS AND THEIR
ENSEMBLES ARE FURTHER EAST BY 100-200 NM. EXPERIENCE SHOWS THAT
THE LACK OF A SIGNIFICANT BLOCKING HIGH TO OUR NORTH OR
NORTHEAST...FAVORS A MORE WESTERN TRACK /SIMILAR TO THE EC AND ITS
ENSEMBLE/. SHOULD THE WWD TREND CONTINUE EVEN FURTHER WITH AN
EARLIER INJECTION OF NRN STREAM ENERGY INTO THE SOUTHERN STREAM
SYSTEM...IT/S CONCEIVABLE THAT OUR FAR SE ZONES /NEAR KLNS AND
KMDT/ COULD EVEN SEE A MIX WITH SLEET AND RAIN FOR A PERIOD THAT
WOULD HOLD DOWN ACCUMULATIONS.
PRECIP MAY START OFF EARLY WED AS A MIX OF RAIN AND SNOW IN THE
SE...BUT COOLING TEMPS ALOFT SHOULD CONVERT ALL PRECIP OVER TO
SNOW BY MIDDAY. AS IS A GENERAL RULE WITH THESE TYPES OF EVENTS...
THERE WILL LIKELY BE A SHARP DROP OFF IN ACCUMULATIONS ON THE NW
EDGE OF THE HEAVIER SNOWS. BIGGEST POTENTIAL IMPACTS IN OUR CWA
WILL BE THE CENTRAL MTNS AND SUSQ VALLEY...WHERE POTENTIAL FOR A
SEVERAL HOUR PERIOD OF HEAVY ACCUMULATING SNOW WILL EXIST. BUT
AGAIN...SMALL CHANGES IN THE ULTIMATE TRACK COULD LEAD TO
MODIFICATIONS OF SNOWFALL FORECASTS. THE TAKE AWAY...THOUGH THE
DETAILS REMAIN UNCERTAIN...THERE WILL BE SIG IMPACTS TO TRAVEL
ALONG THE U.S. EAST COAST ON ONE OF THE BUSIEST DAYS OF THE YEAR
/WED/. PLAN ACCORDINGLY.
COLDER AIR REMAINS IN PLACE LATE IN THE WEEK AS SCT SNOW SHOWERS
RETURN TO THE WESTERN HIGHER TERRAIN. TEMPS LOOK TO GRADUALLY
MODIFY LATE WEEKEND HEADING INTO NEXT WEEK...WITH NO BIG STORM
SYSTEMS EXPECTED AFTER THANKSGIVING.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A LOW PRESSURE SYSTEM TRACKING NORTHWARD INTO THE GRT LKS WILL
SPREAD LOWERING CIGS AND RAIN ACROSS CENTRAL PA TONIGHT. REGIONAL
RADAR AT 06Z SHOWS A DRY SLOT BEGINNING TO ENTER SOUTHWEST PA.
THIS WILL CAUSE CIGS AND VSBYS TO INCREASE...AND SHOULD LIFT
RESTRICTIONS SLOWLY. THE LOW LEVEL MOISTURE REMAINS HIGH AND
SOUTHERLY WINDS IN THE 1-2 KFT LAYER WILL BECOME VERY STRONG
OVERNIGHT...MAKING LLWS A NEAR CERTAINTY. SFC GUSTS OVERNIGHT WILL
BE HIGHEST AT KJST DUE TO IT/S RIDGETOP LOCATION. HRRR OUTPUT
SUGGESTS GUSTS BTWN 25-35KTS ARE POSSIBLE THERE UNTIL 09Z. MUCH
LIGHTER SFC WINDS EXPECTED ELSEWHERE...WHICH WILL LEAD TO THE
LLWS.
THE CONDITIONS LOOK TO IMPROVE QUICKER THAN PREVIOUSLY
MODELED...WHICH MEANS THE LOW CIGS AND LINGERING DRIZZLE WILL
GIVE WAY TO IMPROVING CONDS BY MID MONDAY AM...AS WARM FRONT
LIFTS NORTH OF THE REGION. GENERALLY VFR CONDS ARE ANTICIPATED
MONDAY AFTERNOON.
A COLD FRONT MOVING FROM THE WEST WILL BE ACCOMPANIED BY SCT LATE
DAY SHRA ACROSS THE W MTNS...POSSIBLY PRODUCING A BRIEF VSBY
REDUCTION AT KBFD OR KJST.
OUTLOOK...
TUE...NO SIG WX EXPECTED.
WED...SNOW/LOW VSBYS POSS EASTERN PA.
THU...-SHSN/REDUCED VSBYS POSS NW MTNS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 4 AM EST TUESDAY FOR
PAZ004>006-010-011-017-024-033.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/DEVOIR/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1244 AM EST MON NOV 24 2014
.SYNOPSIS...
STRONG LOW PRESSURE WILL PUSH NORTHWARD THROUGH THE GREAT LAKES
LATE TONIGHT AND MONDAY. IT WILL BRING A SLUG OF RAIN THROUGH THE
STATE TONIGHT. VERY WARM AND EVEN NEAR-RECORD WARM TEMPERATURES
ARE EXPECTED OVER MUCH OF THE AREA MONDAY...BEFORE THE COLD AIR
FOLLOWING THE GREAT LAKES LOW MOVES ACROSS LATE MONDAY AND MONDAY
NIGHT. A DEEPENING AREA OF LOW PRESSURE WILL MOVE NORTHWARD ALONG
THE MID ATLANTIC COAST WEDNESDAY. THERE IS A LOW CONFIDENCE AS TO
WHAT THE EXACT PATH OF THIS STORM WILL BE. HOWEVER...THE EASTERN
THIRD TO HALF OF THE STATE COULD HAVE A SIGNIFICANT SNOWFALL. COLD
AIR WILL FOLLOW FOR NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WARM FRONT LIFTING THROUGH THE VIRGINIAS EARLY THIS MORNING WITH
STRONG SOUTHERLY FLOW ALOFT. VIGOROUS UPPER TROF LIFTING THROUGH
CENTRAL AND EASTERN OHIO WITH WIDESPREAD LIGHT TO MODERATE RAIN
SHIELD EXTENDING FROM NORTHEAST OHIO THROUGH ALL BUT FAR SOUTHWEST
PA. BACK EDGE OF RAIN SHIELD MAKING STEADY PROGRESS NNE
AS PREVIOUSLY MENTIONED...FAST NORTHWARD PROPOGATION OF RAIN
PRECLUDES ANY CONCERNS FOR HEAVY RAIN. GENERAL 0.50 INCHES QPF IS
EXPECTED...BUT SOME HEAVIER AMOUNTS ARE POSSIBLE FAR SOUTHEAST
WHERE CONVECTIVE INSTABILITY IS PREVENT. KEPT MENTION OF T THERE
FOR THE OVERNIGHT.
WINDS ALOFT GET UP TO 50 KTS OVER THE CENTRAL MTNS...BUT THE
GENERAL STABILITY OVER THE BULK OF THE AREA SHOULD KEEP GUSTS DOWN
DURING THE NIGHT. THE EXCEPTION COULD BE THE HIGHER PEAKS IN THE
WEST WHICH COULD BE GUSTY /INTO THE 20 PLUS KT RANGE/ THROUGH THE
NIGHT. TEMPS WILL LIKELY LEVEL-OFF OR EVEN RISE LATER TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
SUBSIDENCE/DRYING IMMEDIATELY BEHIND THE OVERNIGHT WAVE WILL START
THE BREAK-UP OF THE CLOUDS FROM S-N. HOWEVER...THE AMBIENT
MOISTURE WILL BE HIGH IN THE LLVLS AND FLOW OUT OF THE SOUTH
THROUGH THE COLUMN WILL MAKE IT DIFFICULT TO CLEAR THE NORTHERN
HALF OF THE AREA TOO RAPIDLY. THE SOUTH WILL LIKELY GET SOME
DECENT CLEARING AND THE WARM AIR AHEAD OF THE COLD FRONT WILL PUSH
TEMPS TO NEAR-RECORD LEVELS ON MONDAY AFTERNOON. WILL KEEP THE
NUMBERS SLIGHTLY LOWER THAN RECORDS...THOUGH. THIS IS DUE TO THE
UNCERTAINTY OF HOW MUCH SUN TIME WE WILL HAVE. THE BIGGEST TEMP
BUST POTENTIAL AREA /STAY TOO COOL VS FCST/ WILL BE THE
NORTHEASTERN MTNS. THEY COULD STAY TOO CLOUDY. THE INSTABILITY
COULD ALSO TOUCH OFF A FEW SHOWERS -MAINLY IN THE CENTRAL AND
NORTH. THE COLD FRONT SHOULD MOVE THROUGH LATER IN THE DAY AND
EARLY EVENING.
THE WINDS WILL BE THE OTHER STORY - ALONG WITH THE TEMPS. THE
WESTERN MOUNTAINS/ALLEGHENIES WILL BE THE GUSTIEST PLACE. MIXED-
WINDS WITH LITTLE DIRECTIONAL SHEAR OFF BUFKIT SOUNDINGS MAKE FOR
WIND GUSTS EASILY INTO THE UPPER 30KT RANGE...LIKELY INCREASING TO
OCNLY 40-43 KTS IN THE LATE AFTERNOON AND NIGHT. A WIND ADVISORY
WAS RECENTLY ISSUED FOR 17Z MONDAY - 09Z TUESDAY FOR THE NW MTNS
AND LAUREL HIGHLANDS.
THE PERIOD OF LIKELY HIGHEST GUSTS APPEAR TO BE NEAR...AND FOR SEVERAL
HOURS IN THE WAKE OF THE CFROPA /OR FROM 21Z MONDAY TO 05Z
TUESDAY/.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
POTENTIAL FOR SIG WINTER IMPACTS FROM LOW PRESSURE MOVING UP THE
EAST COAST ON WED/WED NIGHT. WILL CONTINUE TO INJECT
INTERPRETATION OF THE LATEST MODEL GUIDANCE WITH EACH 3-HOURLY
UPDATE TO GUIDE DECISION SUPPORT LEADING UP TO THE PRIME TRAVEL
PERIOD FOR THE THANKSGIVING HOLIDAY.
HIGHLY AMPLIFIED AND ACTIVE UPPER AIR PATTERN WILL BRING A PERIOD
OF ACTIVE WEATHER THROUGH THE COMING WEEK. THE 500MB CONFIGURATION
WILL FEATURE ANOMALOUS RIDGING ALONG THE WEST COAST AND IN THE
WESTERN ATLANTIC WITH A FULL-LATITUDE PERSISTENT TROUGH EBBING
AND FLOWING OVER THE CENTRAL AND EASTERN U.S.
AFTER THE EXIT OF MONDAY/S LOW PRESSURE AREA...COLDER TEMPS
RETURN ON BRISK W/SW FLOW FOR TUE DROPPING HIGHS SOME 20-25F FROM
PREV DAYS READINGS. WE/LL ALSO SEE THE RETURN OF LIGHT SNOW
SHOWERS IN THE WESTERN HIGHER TERRAIN.
THEN FOCUS WILL TURN TO A WAVE CURRENTLY DROPPING SE FROM BRITISH
COLUMBIA AND WASHINGTON STATE...WHICH WILL SPAWN AN AREA OF LOW
PRESSURE OVER THE SE US TUESDAY NIGHT...THAT WILL LIKELY MOVE
NORTH NORTHEASTWARD JUST OFF THE EAST COAST WEDNESDAY INTO
THURSDAY.
12Z/18Z OPERATIONAL AND GEFS RUNS ALONG WITH THE 21Z SREF ARE
BECOMING FAIRLY WELL CLUSTERED WITH RESPECT TO THE LOCATION OF THE
NEAR...TO SUB-1000 MB SFC LOW EARLY WED EVENING /NEAR...AND UP TO
ABOUT 200 NM EAST OF DELMARVA PENINSULA/.
THERE IS STILL MUCH UNCERTAINTY AT THIS 60-72 HOUR TIMEFRAME
BEFORE THE EVENT...WITH RESPECT TO THE EXACT TRACK OF THE SFC LOW
AND ASSOCIATED SNOW/RAIN AMOUNTS.
COLD AIR WILL BE IN PLACE WED MORNING AS A /WEAK/ HIGH PRESSURE
RIDGE RETREATS TO THE NORTH AHEAD OF THE APPROACHING LOW.
NORTHERLY FLOW OVER CENTRAL PA NOT PARTICULARLY STRONG IN ANY
MODEL...BUT A SHORTWAVE LOOKS POISED TO SLIDE IN FROM THE GREAT
LAKES ON WED TO ADD SOME SYNOPTIC LIFT TO A RAPIDLY DEEPENING AND
FAST MOVING SURFACE LOW.
THE 12Z ECMWF AND IT`S ENSEMBLE ARE VERY SIMILAR HUGGING THE SFC
LOW ALONG THE SHORELINE...WHILE US/CANADIAN MODELS AND THEIR
ENSEMBLES ARE FURTHER EAST BY 100-200 NM. EXPERIENCE SHOWS THAT
THE LACK OF A SIGNIFICANT BLOCKING HIGH TO OUR NORTH OR
NORTHEAST...FAVORS A MORE WESTERN TRACK /SIMILAR TO THE EC AND ITS
ENSEMBLE/. SHOULD THE WWD TREND CONTINUE EVEN FURTHER WITH AN
EARLIER INJECTION OF NRN STREAM ENERGY INTO THE SOUTHERN STREAM
SYSTEM...IT/S CONCEIVABLE THAT OUR FAR SE ZONES /NEAR KLNS AND
KMDT/ COULD EVEN SEE A MIX WITH SLEET AND RAIN FOR A PERIOD THAT
WOULD HOLD DOWN ACCUMULATIONS.
PRECIP MAY START OFF EARLY WED AS A MIX OF RAIN AND SNOW IN THE
SE...BUT COOLING TEMPS ALOFT SHOULD CONVERT ALL PRECIP OVER TO
SNOW BY MIDDAY. AS IS A GENERAL RULE WITH THESE TYPES OF EVENTS...
THERE WILL LIKELY BE A SHARP DROPOFF IN ACCUMULATIONS ON THE NW
EDGE OF THE HEAVIER SNOWS. BIGGEST POTENTIAL IMPACTS IN OUR CWA
WILL BE THE CENTRAL MTNS AND SUSQ VALLEY...WHERE POTENTIAL FOR A
SEVERAL HOUR PERIOD OF HEAVY ACCUMULATING SNOW WILL EXIST. BUT
AGAIN...SMALL CHANGES IN THE ULTIMATE TRACK COULD LEAD TO
MODIFICATIONS OF SNOWFALL FORECASTS. THE TAKE AWAY...THOUGH THE
DETAILS REMAIN UNCERTAIN...THERE WILL BE SIG IMPACTS TO TRAVEL
ALONG THE U.S. EAST COAST ON ONE OF THE BUSIEST DAYS OF THE YEAR
/WED/. PLAN ACCORDINGLY.
COLDER AIR REMAINS IN PLACE LATE IN THE WEEK AS SCT SNOW SHOWERS
RETURN TO THE WESTERN HIGHER TERRAIN. TEMPS LOOK TO GRADUALLY
MODIFY LATE WEEKEND HEADING INTO NEXT WEEK...WITH NO BIG STORM
SYSTEMS EXPECTED AFTER THANKSGIVING.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A LOW PRES SYSTEM TRACKING NORTHWARD INTO THE GRT LKS WILL SPREAD
LOWERING CIGS AND RAIN ACROSS CENTRAL PA TONIGHT. REGIONAL RADAR
AT 00Z SHOWS THE RAIN ABOUT TO ENTER SOUTHERN PA AND LINEAR
EXTRAPOLATION SUGGESTS THE RAIN WILL OVERSPREAD ALL CENTRAL PA
AIRFIELDS BTWN 02Z-04Z. A BLEND OF LATEST LAMP GUIDANCE...SREF AND
HRRR MDL OUTPUT IMPLY CIGS WILL DROP TO IFR BTWN 04Z-06Z...JUST A
COUPLE HOURS AFTER THE RAIN BEGINS.
SOUTHERLY WINDS IN THE 1-2 KFT LAYER WILL BECOME VERY STRONG
OVERNIGHT...MAKING LLWS A NEAR CERTAINTY. SFC GUSTS OVERNIGHT WILL
BE HIGHEST AT KJST DUE TO IT/S RIDGETOP LOCATION. HRRR OUTPUT
SUGGESTS GUSTS BTWN 25-35KTS ARE POSS THERE BTWN 03Z-07Z. MUCH
LIGHTER SFC WINDS EXPECTED ELSEWHERE...WHICH WILL LEAD TO THE
LLWS.
EARLY LOW CIGS AND LINGERING DRIZZLE WILL GIVE WAY TO IMPROVING
CONDS BY LATE MONDAY AM...AS WARM FRONT LIFTS NORTH OF THE
REGION. GENERALLY VFR CONDS ARE ANTICIPATED MON AFTN. HOWEVER...A
COLD FRONT MOVING FROM THE WEST WILL BE ACCOMPANIED BY SCT LATE
DAY SHRA ACROSS THE W MTNS...POSSIBLY PRODUCING A BRIEF VSBY
REDUCTION AT KBFD OR KJST.
OUTLOOK...
TUE...NO SIG WX EXPECTED.
WED...SNOW/LOW VSBYS POSS EASTERN PA.
THU...-SHSN/REDUCED VSBYS POSS NW MTNS.
FRI...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM NOON TODAY TO 4 AM EST TUESDAY FOR
PAZ004>006-010-011-017-024-033.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO/DEVOIR/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
411 PM MST TUE NOV 25 2014
.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 205 PM MST TUE NOV 25 2014
THE LATEST WATER VAPOR IMAGES AND RAP ANALYSES INDICATED A LARGE
TROUGH OVER THE CNTRL/ERN CONUS WITH A RIDGE OVER THE WEST COAST.
A POTENT SHORT-WAVE TROUGH WAS MOVING ACROSS ERN MT INTO NWRN
SD...AIDED BY A 150-KT UPPER JET. SCT RAIN/SNOW SHOWERS WERE
ACROSS MUCH OF WRN SD AND NERN WY...BUT WITH A DOWNSLOPE HOLE OVER
PARTS OF SWRN SD. AREA WEBCAMS SHOWED AROUND ONE INCH OF SNOW OVER
NERN WY...A TRACE OVER NWRN SD...AND 1-2 INCHES IN THE NRN BLKHLS.
A SFC LOW OVER WRN ND WAS ASSOCIATED WITH 2-5MB/3HR PRES RISES AS
IT MOVED SOUTHEAST...WITH NORTHWEST WINDS OF 20-35 MPH BEHIND THE
LOW MOVING INTO NWRN SD.
THERE IS DECENT MODEL AGREEMENT IN THE SHORT TERM THROUGH AT LEAST
12Z THU. HEIGHTS WILL BE RISING THROUGH THE PERIOD WITH THICKNESSES
RISING WED THROUGH THU. FOR TNGT...THE SHORT-WAVE TROUGH MOVES TO
NERN KS AS THE SFC LOW MOVES TO SWRN IA. THIS WILL TAKE MOST OF THE
PRECIP SOUTHEAST OF THE AREA THIS EVNG...BUT NORTHWEST WINDS WILL
INCREASE ACROSS MOST OF NWRN INTO SCNTRL SD. THE PREVIOUS WIND ADVY
LOOKS GOOD AND WILL NOT CHANGE. BLSN IS EXPECTED TO BE MINIMAL GIVEN
THE WARM TEMPS AND LIMITED SNOWFALL. A LOW-LEVEL BAROCLINIC ZONE
WILL SETUP OVER THE WRN CWA SO WILL KEEP A CHANCE OF SNOW GOING
THERE. COLDER AIR ALSO WILL FLOW INTO THE CWA TNGT GIVEN STRONG COLD
ADVECTION.
ON WED THE BAROCLINIC ZONE INTENSIFIES ACROSS THE WRN CWA...WITH
WARM ADVECTION AND FRONTOGENESIS AIDING IN MESOSCALE LIFT ON THE
ANTICYCLONIC SIDE OF THE UPPER JET. DESPITE WEAK UPPER FORCING...THE
LOW-LEVEL FORCING AND NEARLY SATURATED PROFILES SHOULD LEAD TO SNOW
OVER NERN WY INTO WRN SD. THIS WILL SPREAD NEWD WED NGT AS UPPER
HEIGHTS CONTINUE TO BUILD AND LOW-LEVEL WARM ADVECTION INTENSIFIES.
SREF PTYPE PROBABILITIES AND NAM VERTICAL PROFILES SUPPORT A CHANCE
OF FZRA OVER PARTS OF NWRN SD LATE WED NGT INTO THU MRNG...SO HAVE
ADDED THAT TO THE FCST.
&&
.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014
SNOW/FREEZING RAIN WILL GRADUALLY EXIT THE AREA ON THANKSGIVING...
LINGERING THE LONGEST OVER NW SD.
THE TRICKIEST PART OF THE LONG TERM FORECAST WILL BE TEMPS...
PARTICULARLY THURSDAY AND SATURDAY. LOW AMPLITUDE RIDGING WILL
DEVELOP THANKSGIVING DAY ACROSS THE ROCKIES INTO THE NORTHERN
PLAINS. STRONG WARM AIR ADVECTION WILL DEVELOP WEDNESDAY NIGHT
INTO THURSDAY PUSHING THE WARM FRONT NE INTO THE CENTRAL DAKOTAS.
THE RESULT WILL BE DRY AND MUCH WARMER WEATHER FOR THANKSGIVING
AND FRIDAY. JUST HOW WARM THE SD PLAINS WILL GET ON THURSDAY
DEPENDS ON THE MOVEMENT OF THE WARM FRONT...AS MODELS HAVE A 10-15
DEGREE SPREAD ACROSS THAT AREA. CURRENTLY HAVE HIGHS RANGING FROM
THE 30S ACROSS NW SD TO THE MID 50S IN PORTIONS OF NE WY AND SW
SD. ON FRIDAY...HIGHS WILL REACH THE UPPER 40S TO MID 50S.
THE NEXT COLD FRONT WILL PASS THROUGH THE AREA SATURDAY AS A SHALLOW
TROUGH CROSSES SRN CANADA INTO MT/ND. AGAIN HIGHS WILL DEPEND ON THE
POSITIONING OF THE FRONT...BUT WILL MOST LIKELY BE REACHED IN THE
MORNING...AS TEMPS WILL BE DROPPING THROUGH THE DAY INTO THE TEENS
AND 20S...AND THEN SINGLE DIGITS OVERNIGHT. GFS AND ECMWF ENSEMBLES
HAVE A 45-50 DEGREE SPREAD FOR THE HIGHS ON SATURDAY...AND ABOUT A
30 DEGREE SPREAD FOR LOWS...SO THERE IS MUCH UNCERTAINTY WITH THE
TEMPERATURE FORECAST. SOME LIGHT SNOW CAN BE EXPECTED TO MOVE
SOUTHWARD BEHIND THE COLD FRONT SATURDAY INTO SATURDAY NIGHT.
WELL BELOW AVERAGE TEMPS ARE EXPECTED SUNDAY...WITH SOME LINGERING
LIGHT SNOW POSSIBLE. THEN MODELS SHOW WARMER AIR ADVECTING BACK IN
EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 406 PM MST TUE NOV 25 2014
NW WINDS WILL INCREASE FURTHER THIS EVENING...GUSTING OVER 40KTS
AT TIMES ESPECIALLY OVER NWRN SD...AS A COLD FRONT MOVES THROUGH.
-SN WILL CONTINUE THROUGH TONIGHT INTO WED...ESPECIALLY OVER NERN
WY AND FAR WRN SD. MVFR/IFR CIGS WILL CONTINUE TO SPREAD SWD ACRS
THE REGION TONIGHT AND CONTINUE THROUGH THE DAY ON WED...WITH SOME
LIFR CONDITIONS POSSIBLE ACRS NERN WY INTO THE NRN BLKHLS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 5 AM MST WEDNESDAY FOR SDZ014-025-026-031-
032-043-072-073.
WIND ADVISORY UNTIL 1 AM MST WEDNESDAY FOR SDZ001-002-012-013.
WY...NONE.
&&
$$
SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1001 PM EST TUE NOV 25 2014
.DISCUSSION...
THE 00Z NAM CONTINUES TO SHOW MORE SNOW IN OUR NORTHERN AND EASTERN
AREAS THAN OTHER MODELS...BUT THE GFS AND RAP APPEAR TO BE TRENDING
TOWARD HIGHER AMOUNTS. OBS IN THE MOUNTAINS SHOW TEMPS IN THE MID
30S WITH DEWPOINTS AROUND 30...SO THESE AREAS SHOULD DROP TO AROUND
FREEZING ONCE PRECIP BEGINS. IN THE VALLEY...THERE IS NOTHING IN
THE LATEST OBS OR MODEL GUIDANCE TO INDICATE THAT TEMPS WILL FALL
LOW ENOUGH FOR ACCUMULATING SNOWFALL.
A WINTER STORMS WARNING WILL BE ISSUED FOR JOHNSON...CARTER...AND
UNICOI MOUNTAIN AREAS...WITH AN EMPHASIS ON AREAS ABOVE 2500 FEET.
WILL MENTION PEAK ACCUMULATIONS UP TO 6 INCHES IN THE HIGHEST
TERRAIN...WITH 3 TO 5 BEING MORE COMMON.
NO OTHER SIGNIFICANT CHANGES WILL BE NEEDED FOR THE UPDATE.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...WINTER STORM WARNING UNTIL NOON EST WEDNESDAY FOR JOHNSON-
SOUTHEAST CARTER-UNICOI.
WINTER WEATHER ADVISORY UNTIL NOON EST WEDNESDAY FOR BLOUNT
SMOKY MOUNTAINS-COCKE SMOKY MOUNTAINS-SEVIER SMOKY
MOUNTAINS-SOUTHEAST GREENE.
VA...WINTER WEATHER ADVISORY UNTIL NOON EST WEDNESDAY FOR LEE-RUSSELL-
SCOTT-WASHINGTON-WISE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
512 PM CST TUE NOV 25 2014
.DISCUSSION...
STORM SYSTEM OVER THE EASTERN GULF WILL TRACK NORTHEAST AND ACROSS
NRN FLA TONIGHT. THE STORM SYSTEM IS RATHER LARGE IN AREAL
COVERAGE AND THE WESTERN FRINGES OF THE CLOUDINESS EXTENDS TO THE
MS RIVER. STILL LOOKING AT LOW CHANCES FOR A RAIN AND POSSIBLY A
SNOW MIX LATE TONIGHT FOR THE PLATEAU. HRRR KEEPS THE PRECIP EAST OF THE
MID STATE. HOWEVER...WE WILL STILL KEEP THE LOW POPS IN FOR NOW.
ONLY CHANGE TO THE FCST WILL BE TO INCREASE THE CLOUD COVER.
OVERNIGHT LOWS MAY STILL BE A TAD TOO HIGH. I MAY ADDRESS THAT
LATER THIS EVENING.
UPDATE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 321 PM CST TUE NOV 25 2014/
DISCUSSION...
MID AND HIGH LEVEL CLOUDINESS HAS BEGUN SPREADING ACROSS THE
FORECAST AREA THIS AFTERNOON AHEAD OF A STRONG DEEP-LAYER TROUGH
OVER THE CENTRAL CONUS. THIS FEATURE WILL CONTINUE EASTWARD
TONIGHT...WITH MID AND HIGH LEVEL MOISTURE CONTINUING TO INCREASE
ESPECIALLY ACROSS EASTERN ZONES. CLOUD COVER WILL KEEP TEMPS FROM
PLUMMETING TONIGHT IN THE DRY AIRMASS AT THE SURFACE...BUT LOWS IN
THE UPPER 20S NORTHWEST TO 30S ELSEWHERE SEEM FAIRLY REASONABLE.
AS A SURFACE LOW DEVELOPS OFF THE CAROLINA COAST TONIGHT...WESTERN
EDGE OF ASSOCIATED LIGHT PRECIP SHIELD MAY BRUSH THE PLATEAU
COUNTIES WARRANTING SLIGHT CHANCE POPS...ALTHOUGH BEST LIFT AND
MOISTURE WILL REMAIN TO OUR EAST. FORECAST SOUNDINGS FOR CSV SHOW
THERMODYNAMIC PROFILES WILL BE QUITE WARM SO ANY PRECIP WOULD
BE LIGHT RAIN UNTIL POSSIBLY LATE TONIGHT WHEN TEMPS COULD COOL
ENOUGH FOR A LIGHT RAIN/SNOW MIX...BUT ANY SNOW WOULD BE
NEGLIGIBLE.
ON WEDNESDAY...12Z GFS/ECMWF CONTINUE TO DEPICT A CLIPPER SYSTEM
DIVING SOUTHEAST INTO THE MID STATE BY AFTERNOON THEN QUICKLY
EXITING THE AREA OFF TO THE EAST ON THURSDAY MORNING. ALTHOUGH
TOTAL PRECIP AMOUNTS LOOK TO BE QUITE LIGHT AND GENERALLY LESS
THAN 0.25 INCHES...WILL RAISE POPS INTO THE CHANCE CATEGORY
AREAWIDE AS MOST AREAS ESPECIALLY NORTHERN ZONES WILL SEE SOME
PRECIPITATION. FORECAST SOUNDINGS WITH THIS SYSTEM ALSO SHOW WARM
THERMODYNAMIC PROFILES AS WELL AS SHALLOW MOISTURE GENERALLY
CONFINED TO BELOW 600MB...SO ONLY LIGHT RAIN IS EXPECTED FOR MOST
AREAS. HOWEVER...BY LATE WEDNESDAY EVENING THERMO PROFILES COOL
ENOUGH ON THE PLATEAU FOR A POTENTIAL LIGHT RAIN/SNOW MIX...WITH A
CHANGEOVER TO ALL SNOW POSSIBLE IN THE OVERNIGHT HOURS WEDNESDAY
NIGHT. SINCE PRECIP AMOUNTS LOOK TO BE QUITE LIGHT...MOISTURE WILL
BE VERY SHALLOW...AND SURFACE TEMPS/WET BULB ZERO TEMPS REMAIN
NEAR OR ABOVE FREEZING...ONLY A LIGHT DUSTING OF SNOW IF ANY LOOKS
POSSIBLE AND HAVE ONLY INCLUDE A FEW TENTHS IN GRIDS.
IN THE WAKE OF THE CLIPPER SYSTEM...A COLD THANKSGIVING IS IN
STORE WITH GUIDANCE TRENDING COLDER SHOWING HIGHS STRUGGLING TO
GET OUT OF THE 30S AND INTO THE 40S. GUIDANCE ALSO SUGGESTS SOME
LOW LEVEL CONVECTIVE-TYPE LIGHT DRIZZLE/RAIN SHOWERS OR FLURRIES
ARE POSSIBLE THANKSGIVING MORNING AND HAVE INCLUDED A SLIGHT
CHANCE MENTION...BUT NO IMPACTS OR ACCUMULATIONS ARE ANTICIPATED.
FRIDAY MORNING LOOKS TO BE THE COLDEST WITH SKIES CLEARING AND
LIGHT WINDS ALLOWING FOR LOWS WELL DOWN INTO THE 20S FOR ALL
ZONES. HOWEVER...A BIG WARMUP IS IN STORE FOR THE WEEKEND INTO
EARLY NEXT WEEK AS HEIGHTS ALOFT RISE ACROSS THE AREA AHEAD OF A
DEEPENING UPPER TROUGH IN THE WESTERN CONUS. RETURN FLOW OFF THE
GULF WILL BRING INCREASING CLOUDS AND LOW LEVEL MOISTURE WITH
DEWPOINTS QUICKLY RISING INTO THE 50S BY SATURDAY...WITH A WEAK
STATIONARY FRONT TAKING SHAPE TO OUR NORTHWEST NEAR THE OHIO
RIVER. CONTINUED WAA AND NEARBY BOUNDARY WILL PROMPT LOW POPS EACH
DAY IN THE EXTENDED FORECAST PERIOD...WITH TEMPERATURES
SIGNIFICANTLY ABOVE NORMAL WITH HIGHS IN THE 60S AND LOWS ONLY IN
THE 40S AND 50S.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1128 PM CST SUN NOV 23 2014
.AVIATION 06Z DISCUSSION...
STORM SYSTEM TO CONTINUE PULLING EAST OVERNIGHT. WE WILL STILL SEE
A FEW RESIDUAL SHOWERS THROUGH THE EARLY MORNING HOURS.
OTW...PRECIP TO CONTINUE TO DIMINISH. PRESSURE GRADIENT WILL
TIGHTEN OVERNIGHT AND WINDS WILL REMAIN BREEZY AND GUSTY AT TIMES.
COLD FRONT TO PUSH THROUGH BETWEEN 12Z AND 15Z WITH WINDS SHIFTING
FROM SOUTHERLY TO SOUTHWESTERLY.
AS FOR CIGS...LOW LEVEL CLOUDINESS WILL PERSIST BUT CIGS WILL
LIFT SOME TOWARD THE END OF THE TAF PD.
&&
.PREV DISCUSSION... /ISSUED 734 PM CST SUN NOV 23 2014/
DISCUSSION...
STRONG VORT AXIS MOVING THROUGH THE MID STATE AT THIS TIME WITH
WIDESPREAD SHOWER ACTIVITY. NOT MUCH IN THE WAY OF PRECIP COVERAGE
BACK TO OUR SOUTHWEST. HRRR SHOWS THAT PRECIP COVERAGE WILL
DECREASE MARKEDLY FROM SW TO NE OVER THE NEXT FEW HOURS.
HOWEVER...ADDITIONAL LIGHT SHOWER ACTIVITY WILL RETURN AFTER
OR JUST BEFORE MIDNIGHT. THEREFORE...CURRENT FCST LOOKS TO BE IN
GOOD SHAPE AS THE POPS WILL DROP DOWN INTO THE CHANCE CATEGORY AFT
MIDNIGHT.
AS FOR THE WIND ADVISORY...GRADIENT STILL LOOKS AS THOUGH IT WILL
BECOME TIGHTER TOWARD 12Z WHEN THE FRONT ROLLS THROUGH. CURRENT
SFC ANALYSIS SHOWS THAT PEAK WINDS ARE GENERALLY IN THE 25 TO 35
MPH RANGE.
SO BASICALLY...NO CHANGES AT THIS TIME TO THE FCST. WILL LIKELY
SEND OUT ANOTHER SET OF ZONES AND LOWER POPS TOWARD THE SOUTHWEST
ONCE THIS CURRENT BATCH OF SHOWERS LIFTS TO THE NORTHEAST.
WINDS MAY ACTUALLY BECOME A LITTLE STRONGER ONCE THE PRECIP FREE
AREA MOVES IN. TEMPS STILL LOOK TO BE IN GOOD SHAPE.
WILL ISSUE THE UPDATE A LITTLE LATER THIS EVENING AND BEGIN TO
LOWER POPS...SOME...ACROSS THE AREA.
PREV DISCUSSION... /ISSUED 609 PM CST SUN NOV 23 2014/
AVIATION 00Z DISCUSSION...
STORM SYSTEM TO PULL EAST OVERNIGHT. WE WILL STILL SEE SOME
RESIDUAL SHOWER ACTIVITY THROUGH THE EVENING HOURS BEFORE THE
PRECIP DECREASES IN COVERAGE AND INTENSITY. OTW...PRESSURE
GRADIENT WILL TIGHTEN OVERNIGHT AND WINDS WILL REMAIN BREEZY AND
GUSTY AT TIMES.
AS FOR CIGS...LOW LEVEL CLOUDINESS WILL PERSIST BUT CIGS WILL
LIFT SOME TOWARD THE END OF THE TAF PD.
PREV DISCUSSION... /ISSUED 340 PM CST SUN NOV 23 2014/
DISCUSSION...IT HAS BEEN A RAINY AND INCREASINGLY BREEZY DAY
ACROSS MID TN. AFTERNOON TEMPERATURES WERE IN THE MID TO UPPER
50S. THE MAIN RAIN SHIELD IS LIFTING ACROSS MID TN...AND SOME
BREAKS IN THE RAIN ARE MOVING INTO THE SW COUNTIES. THESE BREAKS
IN TE RAIN WILL SPREAD ACROSS MID TN OVER THE NEXT COUPLE OF
HOURS...BUT WE WILL KEEP HIGH POPS THROUGH THE EVENING AS RADAR
SHOWS MORE SHOWERS MOVING UP FROM THE SOUTHWEST. THE POPS WILL
DROP OFF MORE SIGNIFICANTLY LATE TONIGHT. NO THUNDERSTORMS HAVE
BEEN OBSERVED TODAY...BUT A LIGHTNING STRIKE OR 2 COULD OCCUR
EARLY THIS EVENING.
THE MAIN CONCERN FOR THIS EVENING THROUGH TONIGHT IS THE WIND
POTENTIAL. A VORT MAX AND SMALL SCALE SURFACE LOW PRESSURE CENTER
FROM WEST CENTRAL MS WILL ZIP UP THE MS RIVER LATE THIS AFTERNOON
AND EVENING...MEETING UP WITH A DEEPENING SYNOPTIC SCALE LOW
PRESSURE FROM OK. A LLJ WILL STRENGTHEN TO 50-60KT. SURFACE WIND
GUSTS WILL REACH OVER 40 MPH AT TIMES. THE MAIN TIME FOR THIS
WILL BE FROM 5 PM TO 10 PM...AND THESE STRONGER GUSTS WILL AFFECT
LOCATIONS MAINLY ALONG AND WEST OF I 65. WE HAVE ALREADY ISSUED A
WIND ADVISORY FOR THE MID STATE WEST OF THE PLATEAU.
FOR LATER TONIGHT THROUGH MONDAY...THE CONSOLIDATED LOW PRESSURE
SYSTEM WILL ACCELERATE ACROSS THE GREAT LAKES REGION AND INTO
EASTERN CANADA. EVEN THROUGH THE LOW WILL BE MOVING AWAY...IT WILL
STRENGTHEN...RESULTING IN STRONG WINDS ACROSS A WIDE AREA. FOR MID
TN...THIS MEANS THAT WINDS WILL INCREASE AGAIN TOWARD
DAYBREAK...WITH SPEEDS OF 20-30 MPH AND SOME 45 MPH THROUGH MONDAY
MORNING. GUSTS OF THAT STRENGTH COULD EASILY BRING DOWN SOME LIMBS
AND WEAKER TREES...AND CAUSE SCATTERED POWER OUTAGES. THERE WILL
CONTINUE TO BE A CHANCE FOR SCATTERED SHOWERS INTO MONDAY
MORNING...THEN DRIER AIR IS EXPECTED MONDAY AFTERNOON. WIND GUSTS
WILL TAPER OFF SLIGHTLY MONDAY AFTERNOON...BUT STILL FREQUENTLY
OVER 30 MPH UNDER PARTLY SUNNY SKIES.
DRY AND COOLER WX MOVES IN FOR MONDAY NIGHT...AND WILL STAY
THROUGH THE REST OF THE WEEK. THERE ARE A COUPLE OF MIDWEEK
SYSTEMS THAT NEED TO BE WATCHED FOR SOME SHOWER POTENTIAL.
MODELS HAVE BEEN VERY INCONSISTENT WITH THESE FEATURES...BUT IT
LOOKS LIKE THEY WILL NOT HAVE MUCH IMPACT ON MID TN. SO...AFTER A
VERY ACTIVE BEGINNING OF THIS WEEK...QUIET CONDITIONS ARE EXPECTED
FOR THE THANKSGIVING HOLIDAY WITH GENERALLY COOLER THAN NORMAL
TEMPS.
13
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 6 PM CST MONDAY FOR TNZ005>011-023>033-
056>064-075-077-093>095.
&&
$$
21
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1131 AM CST MON NOV 24 2014
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...FAVORABLE FLYING CONDITIONS ARE FORECAST THE NEXT 24
HOURS WITH MODERATE NORTH WINDS AND DRYING LOW LEVELS. A THIRD
NIGHT OF FOG IS NOT CURRENTLY FORECAST AS SURFACE CONDITIONS
SHOULD BE TOO DRY. /68-JGG/
&&
.PREV DISCUSSION... /ISSUED 548 AM CST MON NOV 24 2014/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...COLD FRONT IS CURRENTLY SLICING THROUGH SOUTHERN
CAMERON COUNTY WITH DENSE FOG REMAINING OVER THE BRO TERMINAL
CURRENTLY WITH CONDITIONS SLOWLY IMPROVING AT THE HRL TERMINAL.
FRONT SHOULD PASS THROUGH THE BRO TERMINAL AROUND 12Z WITH
VIS/CIGS SLOWLY IMPROVING THROUGH 13Z. VFR SHOULD RETURN TO
BRO/HRL TERMINALS BY 1330Z. GUSTY NORTHERLY WINDS EXPECTED BEHIND
THE FRONT AND THROUGH MOST OF THE DAY WITH DECREASING WINDS
TOWARDS SUNSET. SHOULD EXPERIENCE PLENTY OF HIGH LEVEL CLOUDS BUT
NOT MUCH IN THE WAY OF LOW/MID CLOUDS AS THE ATMOSPHERE SHOULD
REMAIN DRY IN THESE LEVELS.
PREV DISCUSSION... /ISSUED 349 AM CST MON NOV 24 2014/
SHORT TERM /NOW THROUGH TUESDAY/...EXPANDED THE DENSE FOG
ADVISORY TO COVER ALL THE COASTAL AREAS AND GULF WATERS 0-20NM
EAST OF THE COASTLINE. DENSE MARINE FOG ADVECTED IN THROUGH THE
OVERNIGHT HOURS AND HAS CONTINUED ITS N-NW PROGRESSION EVEN
REACHING EASTERN HIDALGO COUNTY. DID ALSO EXTEND THE TIMING
THROUGH 12Z BASED ON THE HRRR NOT BRINGING FROPA THROUGH THE LOWER
VALLEY TILL 12Z AND STRONGER WINDS NOT UNTIL 14Z. SPEAKING OF THE
FRONT...11-3.9 MICRON SHOWS THE FRONT CLEARLY THROUGH MIDDLE TEXAS
COASTAL WATERS AS A FINE LINE OF LOWER STRATUS WITH KRKP AND KCRP
WIND DIRECTIONS SWITCHING TO THE NORTHWEST. EXTRAPOLATING USING
CURRENT SPEED PLACES THE FRONT IN THE LOWER VALLEY BY 12Z MATCHING
UP WITH THE HRRR.
NORTH WINDS WILL PICK UP AFTER THE FRONTAL PASSAGE WITH BREEZY
CONDITIONS THROUGH THE MORNING HOURS WITH WINDS DIMINISHING INTO THE
AFTERNOON HOURS. ALONG THE COAST THE WINDS WILL STAY UP A LITTLE
LONGER THAN MORE INLAND AREAS. WILL BE A NICE AND COOL DAY TODAY
WITH A SOME PASSING HIGH CLOUDS FROM TIME TO TIME. HIGHS WILL BE IN
THE UPPER 60S IN THE RANCHLANDS TO LOWER 70S IN THE VALLEY. SFC HIGH
PRESSURE BUILDS INTO CENTRAL TEXAS OVERNIGHT THEN SINK SOUTHWARDS ON
TUESDAY. WINDS WILL BE FAIRLY LIGHT TONIGHT INTO TUESDAY AND WILL
KEEP SOME CLOUDS CLOUDS AROUND WITH SOUTHWESTERLY FLOW IN THE
MID/UPPER LEVELS UNTIL THE 500MB TROUGH UPSTREAM SWINGS THROUGH
TUESDAY AFTERNOON. MET/MAV TEMPERATURES TONIGHT CAME IN COOLER SO
TRENDED OUR TEMPERATURES DOWNWARD A DEGREE OR TWO ESPECIALLY IN
OUTLYING AREAS. TUESDAY HIGHS ARE A REPEAT OF TODAY.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...EXTENDED PERIOD
CONTINUES TO LOOK PRETTY QUIET AND LITTLE CHANGE WAS MADE TO THE
PRIOR FORECAST. ALL IN ALL A MILD AND FAIRLY DRY WEEK IS IN THE
WORKS. SHORTWAVE TROUGH WILL BE EXITING THE REGION TUESDAY NIGHT
WITH FLOW ALOFT VEERING TO THE NORTHWEST. THE NORTHWEST FLOW WILL
BRING DRY AIR OVER THE REGION...RESULTING IN MOSTLY CLEAR SKIES
TUESDAY NIGHT INTO THURSDAY. TUESDAY NIGHT WILL BE THE COLDEST OF THE
WEEK AS CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPERATURES TO FALL
INTO THE LOWER AND MID 40S. BELOW NORMAL TEMPERATURES WILL CONTINUE
WEDNESDAY THROUGH THURSDAY...WITH HIGHS IN THE LOWER 70S AND LOWS IN
THE MID TO UPPER 40S NORTH AND UPPER 40S TO LOWER 50S SOUTH.
TEMPERATURES AND CLOUD COVER BEGIN TO INCREASE ON FRIDAY AS MODERATE
SOUTHEASTERLY FLOW RETURNS. A 500 MB TROUGH/CUTOFF LOW DEVELOPS OVER
NORTHERN MEXICO ON THURSDAY AND SLOWLY NUDGES EAST THROUGH THE
WEEKEND. THE WEAK TROUGH COMBINED WITH THE INCREASED MOISTURE COULD
RESULT IN A FEW STREAMER SHOWERS OVER THE COASTAL WATERS ON SUNDAY.
MARINE...
NOW THROUGH TUESDAY...A FRONT WILL SWEEP ACROSS THE AREA EARLY
THIS MORNING WITH WINDS SWITCHING TO THE NORTH IN ITS WAKE. STRONG
NORTH WINDS WILL ROUGHEN SEAS AND A SMALL CRAFT ADVISORY HAS BEEN
ISSUED FOR THE GULF OF MEXICO WATERS OF THE LOWER TEXAS COAST
THROUGH MONDAY AFTERNOON. ROUGH SEAS WILL BECOME MORE MODERATE
MONDAY NIGHT INTO AS WIND SPEEDS DECREASE. HOWEVER...A SECONDARY
SURGE OF STRONGER WINDS LOOK TO INVADE AT LEAST THE 20-60NM WATERS
TUESDAY AROUND THE DEPARTING SYSTEM WHICH SMALL CRAFT ADVISORIES
MAY BE NEEDED FOR THE FAR OFFSHORE WATERS FOR SEAS RISING BACK UP
TO AROUND 7 FEET.
TUESDAY NIGHT THROUGH FRIDAY...NORTH WINDS TUESDAY EVENING WILL
BEGIN TO DIMINISH AND SEAS WILL BEGIN TO SUBSIDE AS THE PRESSURE
GRADIENT WEAKENS. SMALL CRAFT ADVISORIES MAY NEEDED TUESDAY NIGHT
FOR THE FAR OFFSHORE WATERS FOR SEAS OF 7 FEET. SEAS WILL CONTINUE
TO SUBSIDE THROUGH THE DAY WEDNESDAY. LIGHT TO MODERATE SOUTHEAST
WINDS AND LOW SEAS WILL PREVAIL THURSDAY AND FRIDAY.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL NOON CST TODAY FOR GMZ130-
132-135.
SMALL CRAFT ADVISORY UNTIL 5 PM CST THIS AFTERNOON FOR GMZ150-
155-170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
68/61
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
548 AM CST MON NOV 24 2014
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...COLD FRONT IS CURRENTLY SLICING THROUGH SOUTHERN
CAMERON COUNTY WITH DENSE FOG REMAINING OVER THE BRO TERMINAL
CURRENTLY WITH CONDITIONS SLOWLY IMPROVING AT THE HRL TERMINAL.
FRONT SHOULD PASS THROUGH THE BRO TERMINAL AROUND 12Z WITH
VIS/CIGS SLOWLY IMPROVING THROUGH 13Z. VFR SHOULD RETURN TO
BRO/HRL TERMINALS BY 1330Z. GUSTY NORTHERLY WINDS EXPECTED BEHIND
THE FRONT AND THROUGH MOST OF THE DAY WITH DECREASING WINDS
TOWARDS SUNSET. SHOULD EXPERIENCE PLENTY OF HIGH LEVEL CLOUDS BUT
NOT MUCH IN THE WAY OF LOW/MID CLOUDS AS THE ATMOSPHERE SHOULD
REMAIN DRY IN THESE LEVELS.
&&
.PREV DISCUSSION... /ISSUED 349 AM CST MON NOV 24 2014/
SHORT TERM /NOW THROUGH TUESDAY/...EXPANDED THE DENSE FOG
ADVISORY TO COVER ALL THE COASTAL AREAS AND GULF WATERS 0-20NM
EAST OF THE COASTLINE. DENSE MARINE FOG ADVECTED IN THROUGH THE
OVERNIGHT HOURS AND HAS CONTINUED ITS N-NW PROGRESSION EVEN
REACHING EASTERN HIDALGO COUNTY. DID ALSO EXTEND THE TIMING
THROUGH 12Z BASED ON THE HRRR NOT BRINGING FROPA THROUGH THE LOWER
VALLEY TILL 12Z AND STRONGER WINDS NOT UNTIL 14Z. SPEAKING OF THE
FRONT...11-3.9 MICRON SHOWS THE FRONT CLEARLY THROUGH MIDDLE TEXAS
COASTAL WATERS AS A FINE LINE OF LOWER STRATUS WITH KRKP AND KCRP
WIND DIRECTIONS SWITCHING TO THE NORTHWEST. EXTRAPOLATING USING
CURRENT SPEED PLACES THE FRONT IN THE LOWER VALLEY BY 12Z MATCHING
UP WITH THE HRRR.
NORTH WINDS WILL PICK UP AFTER THE FRONTAL PASSAGE WITH BREEZY
CONDITIONS THROUGH THE MORNING HOURS WITH WINDS DIMINISHING INTO THE
AFTERNOON HOURS. ALONG THE COAST THE WINDS WILL STAY UP A LITTLE
LONGER THAN MORE INLAND AREAS. WILL BE A NICE AND COOL DAY TODAY
WITH A SOME PASSING HIGH CLOUDS FROM TIME TO TIME. HIGHS WILL BE IN
THE UPPER 60S IN THE RANCHLANDS TO LOWER 70S IN THE VALLEY. SFC HIGH
PRESSURE BUILDS INTO CENTRAL TEXAS OVERNIGHT THEN SINK SOUTHWARDS ON
TUESDAY. WINDS WILL BE FAIRLY LIGHT TONIGHT INTO TUESDAY AND WILL
KEEP SOME CLOUDS CLOUDS AROUND WITH SOUTHWESTERLY FLOW IN THE
MID/UPPER LEVELS UNTIL THE 500MB TROUGH UPSTREAM SWINGS THROUGH
TUESDAY AFTERNOON. MET/MAV TEMPERATURES TONIGHT CAME IN COOLER SO
TRENDED OUR TEMPERATURES DOWNWARD A DEGREE OR TWO ESPECIALLY IN
OUTLYING AREAS. TUESDAY HIGHS ARE A REPEAT OF TODAY.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...EXTENDED PERIOD
CONTINUES TO LOOK PRETTY QUIET AND LITTLE CHANGE WAS MADE TO THE
PRIOR FORECAST. ALL IN ALL A MILD AND FAIRLY DRY WEEK IS IN THE
WORKS. SHORTWAVE TROUGH WILL BE EXITING THE REGION TUESDAY NIGHT
WITH FLOW ALOFT VEERING TO THE NORTHWEST. THE NORTHWEST FLOW WILL
BRING DRY AIR OVER THE REGION...RESULTING IN MOSTLY CLEAR SKIES
TUESDAY NIGHT INTO THURSDAY. TUESDAY NIGHT WILL BE THE COLDEST OF THE
WEEK AS CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPERATURES TO FALL
INTO THE LOWER AND MID 40S. BELOW NORMAL TEMPERATURES WILL CONTINUE
WEDNESDAY THROUGH THURSDAY...WITH HIGHS IN THE LOWER 70S AND LOWS IN
THE MID TO UPPER 40S NORTH AND UPPER 40S TO LOWER 50S SOUTH.
TEMPERATURES AND CLOUD COVER BEGIN TO INCREASE ON FRIDAY AS MODERATE
SOUTHEASTERLY FLOW RETURNS. A 500 MB TROUGH/CUTOFF LOW DEVELOPS OVER
NORTHERN MEXICO ON THURSDAY AND SLOWLY NUDGES EAST THROUGH THE
WEEKEND. THE WEAK TROUGH COMBINED WITH THE INCREASED MOISTURE COULD
RESULT IN A FEW STREAMER SHOWERS OVER THE COASTAL WATERS ON SUNDAY.
MARINE...
NOW THROUGH TUESDAY...A FRONT WILL SWEEP ACROSS THE AREA EARLY
THIS MORNING WITH WINDS SWITCHING TO THE NORTH IN ITS WAKE. STRONG
NORTH WINDS WILL ROUGHEN SEAS AND A SMALL CRAFT ADVISORY HAS BEEN
ISSUED FOR THE GULF OF MEXICO WATERS OF THE LOWER TEXAS COAST
THROUGH MONDAY AFTERNOON. ROUGH SEAS WILL BECOME MORE MODERATE
MONDAY NIGHT INTO AS WIND SPEEDS DECREASE. HOWEVER...A SECONDARY
SURGE OF STRONGER WINDS LOOK TO INVADE AT LEAST THE 20-60NM WATERS
TUESDAY AROUND THE DEPARTING SYSTEM WHICH SMALL CRAFT ADVISORIES
MAY BE NEEDED FOR THE FAR OFFSHORE WATERS FOR SEAS RISING BACK UP
TO AROUND 7 FEET.
TUESDAY NIGHT THROUGH FRIDAY...NORTH WINDS TUESDAY EVENING WILL
BEGIN TO DIMINISH AND SEAS WILL BEGIN TO SUBSIDE AS THE PRESSURE
GRADIENT WEAKENS. SMALL CRAFT ADVISORIES MAY NEEDED TUESDAY NIGHT
FOR THE FAR OFFSHORE WATERS FOR SEAS OF 7 FEET. SEAS WILL CONTINUE
TO SUBSIDE THROUGH THE DAY WEDNESDAY. LIGHT TO MODERATE SOUTHEAST
WINDS AND LOW SEAS WILL PREVAIL THURSDAY AND FRIDAY.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR
TXZ254>257.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL NOON CST TODAY FOR GMZ130-
132-135.
DENSE FOG ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR GMZ130-
132-150.
SMALL CRAFT ADVISORY UNTIL 5 PM CST THIS AFTERNOON FOR GMZ150-
155-170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
514 AM CST MON NOV 24 2014
.DISCUSSION...SEE 12Z AVIATION DISCUSSION.
&&
.AVIATION...VFR. GUSTY NORTH WINDS EASTERN TAFS TODAY WILL
DIMINISH LATER THIS AFTERNOON. MID/HIGH CLOUD COVER IS EXPECTED
OVERNIGHT WITH UPPER LEVEL DISTURBANCE. WINDS MAY PICK UP A TAD
WITH IT TOO...BUT NOTHING ABOVE 11 KNOTS EXPECTED ON AVERAGE.
&&
.PREV DISCUSSION... /ISSUED 320 AM CST MON NOV 24 2014/
SHORT TERM (TODAY THROUGH TUESDAY)...COOLER WEATHER ON THE WAY AS
THE COLD FRONT MOVES THROUGH SOUTH TEXAS EARLY THIS MORNING. TOO DRY
NEAR THE SURFACE FOR SHOWERS...AND THAT DRIER AIR IN THE LOWER AND
MID LEVELS REMAINS (MOISTENS UP 700MB AND ABOVE TONIGHT). PRETTY
POTENT UPPER TROUGH AND JET IMPACT AREA OVERNIGHT AND TUESDAY
MORNING...AND MOISTURE 700MB AND ABOVE DUE TO LIFT MAY PRODUCE A
SPRINKLE OR TWO OVER EXTREME EASTERN AREAS AND COASTAL WATERS
(MAINLY CLOUDS THOUGH). HOWEVER...SINCE SPRINKLES WILL NOT MENTION.
WILL GO WITH PARTLY TO MOSTLY CLOUDY SKIES TUESDAY MORNING AS THERE
SHOULD BE SUFFICIENT MID AND HIGH CLOUDS TO PRECLUDE SOME SUN AT
LEAST UNTIL THE AFTERNOON WHEN AREA GETS ON THE SUBSIDENCE SIDE OF
UPPER SYSTEM. AM GOING TO GO ON THE COOLER SIDE OF GUIDANCE FOR
TEMPERATURES TODAY AND TUESDAY...BUT MORE ON THE WARM SIDE FOR
TONIGHT AS MID AND HIGH CLOUDS WILL PREVENT TEMPERATURES FROM
FALLING TOO MUCH. WIND FORECAST GENERALLY A BLEND OF RUC13 AND
NAM12 FOR THE MORNING...THEN A BLEND OF THE NAM AND MOS FOR THE
AFTERNOON THROUGH TUESDAY.
MARINE (TODAY THROUGH TUESDAY)...WILL ADJUST SCA TO KEEP THE
NEARSHORE IN A BIT LONGER (TIL ABOUT NOON)...AND THE OFFSHORE TIL
ABOUT 5 PM...GIVEN WIND AND WAVE FORECAST. SCA CONDITIONS WILL
LIKELY DEVELOP AGAIN LATE TONIGHT OR TUESDAY. HOWEVER...WILL HOLD
OFF ON HAVING AN SCA FOR THAT AT THIS TIME SINCE 3RD PERIOD AND
WINDS AND WAVES WILL TAPER OFF SOME TONIGHT (AND BORDERLINE SCA AT
THAT). WILL LET NEXT SHIFT TAKE A PEEK AT THIS.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...GENERALLY BENIGN
FORECAST THROUGH THE LONG TERM PERIOD...BUT A FEW DETAILS TO
CONSIDER IN THE OVERALL PATTERN. UPPER LEVEL DISTURBANCE PUSHING
EAST OF THE AREA AT ONSET OF LONG TERM PERIOD. SHOULD BE CLEARING
OUT QUICKLY TUESDAY NIGHT...IF NOT ALREADY CLEARED LATE TUESDAY
AFTERNOON. VERY DRY AIR FILTERS IN WITH REINFORCING RIDGE WITH PWATS
WELL BELOW HALF INCH OVER MUCH OF THE AREA. A COUPLE OF WEAK
SHORTWAVES NOTED IN THE UPPER LEVEL PATTERN FRI EVENING AND SUNDAY.
CONFIDENT THAT AIR WILL STILL BE DRY FOR FRIDAY EVENING SHORT
WAVE...BUT SUNDAY WEAK DISTURBANCE COULD HAVE THE POTENTIAL FOR SOME
POPS AS A SOUTHERLY FLOW WILL HAVE DEVELOPED LATE IN THE WEEK. AT
THIS TIME WITH A MAINLY SOUTHERLY FLOW RATHER THAN SOUTHEAST...NOT
THINKING TOO HIGHLY OF SLIGHT CHANCE POPS SOME MODELS ARE
INDICATING. WILL KEEP THE FORECAST DRY AT THIS TIME.
TEMPS FOR THE WEEK SHOULD BE WAVERING AROUND NORMAL FOR HIGHS.
SLIGHTLY BELOW NORMAL LOWS ARE LIKELY EARLY IN THE WEEK WITH HIGH
PRESSURE AND CLEAR SKIES...BUT WILL WARM TO ABOVE NORMAL BY THE
WEEKEND AS MOISTURE GRADUALLY WORKS ITS WAY BACK IN.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 67 45 69 44 70 / 0 0 0 0 0
VICTORIA 65 41 64 41 70 / 0 10 10 0 0
LAREDO 68 48 69 41 73 / 0 0 0 0 0
ALICE 67 43 70 41 72 / 0 0 0 0 0
ROCKPORT 67 48 65 52 69 / 0 10 10 0 0
COTULLA 66 42 67 39 72 / 0 0 0 0 0
KINGSVILLE 68 44 69 42 72 / 0 0 0 0 0
NAVY CORPUS 67 52 68 50 69 / 0 10 10 0 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT
ARANSAS...COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS
OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 5 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
GW/86...AVIATION
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
349 AM CST MON NOV 24 2014
.SHORT TERM /NOW THROUGH TUESDAY/...EXPANDED THE DENSE FOG
ADVISORY TO COVER ALL THE COASTAL AREAS AND GULF WATERS 0-20NM
EAST OF THE COASTLINE. DENSE MARINE FOG ADVECTED IN THROUGH THE
OVERNIGHT HOURS AND HAS CONTINUED ITS N-NW PROGRESSION EVEN
REACHING EASTERN HIDALGO COUNTY. DID ALSO EXTEND THE TIMING
THROUGH 12Z BASED ON THE HRRR NOT BRINGING FROPA THROUGH THE LOWER
VALLEY TILL 12Z AND STRONGER WINDS NOT UNTIL 14Z. SPEAKING OF THE
FRONT...11-3.9 MICRON SHOWS THE FRONT CLEARLY THROUGH MIDDLE TEXAS
COASTAL WATERS AS A FINE LINE OF LOWER STRATUS WITH KRKP AND KCRP
WIND DIRECTIONS SWITCHING TO THE NORTHWEST. EXTRAPOLATING USING
CURRENT SPEED PLACES THE FRONT IN THE LOWER VALLEY BY 12Z MATCHING
UP WITH THE HRRR.
NORTH WINDS WILL PICK UP AFTER THE FRONTAL PASSAGE WITH BREEZY
CONDITIONS THROUGH THE MORNING HOURS WITH WINDS DIMINISHING INTO THE
AFTERNOON HOURS. ALONG THE COAST THE WINDS WILL STAY UP A LITTLE
LONGER THAN MORE INLAND AREAS. WILL BE A NICE AND COOL DAY TODAY
WITH A SOME PASSING HIGH CLOUDS FROM TIME TO TIME. HIGHS WILL BE IN
THE UPPER 60S IN THE RANCHLANDS TO LOWER 70S IN THE VALLEY. SFC HIGH
PRESSURE BUILDS INTO CENTRAL TEXAS OVERNIGHT THEN SINK SOUTHWARDS ON
TUESDAY. WINDS WILL BE FAIRLY LIGHT TONIGHT INTO TUESDAY AND WILL
KEEP SOME CLOUDS CLOUDS AROUND WITH SOUTHWESTERLY FLOW IN THE
MID/UPPER LEVELS UNTIL THE 500MB TROUGH UPSTREAM SWINGS THROUGH
TUESDAY AFTERNOON. MET/MAV TEMPERATURES TONIGHT CAME IN COOLER SO
TRENDED OUR TEMPERATURES DOWNWARD A DEGREE OR TWO ESPECIALLY IN
OUTLYING AREAS. TUESDAY HIGHS ARE A REPEAT OF TODAY.
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...EXTENDED PERIOD
CONTINUES TO LOOK PRETTY QUIET AND LITTLE CHANGE WAS MADE TO THE
PRIOR FORECAST. ALL IN ALL A MILD AND FAIRLY DRY WEEK IS IN THE
WORKS. SHORTWAVE TROUGH WILL BE EXITING THE REGION TUESDAY NIGHT
WITH FLOW ALOFT VEERING TO THE NORTHWEST. THE NORTHWEST FLOW WILL
BRING DRY AIR OVER THE REGION...RESULTING IN MOSTLY CLEAR SKIES
TUESDAY NIGHT INTO THURSDAY. TUESDAY NIGHT WILL BE THE COLDEST OF THE
WEEK AS CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPERATURES TO FALL
INTO THE LOWER AND MID 40S. BELOW NORMAL TEMPERATURES WILL CONTINUE
WEDNESDAY THROUGH THURSDAY...WITH HIGHS IN THE LOWER 70S AND LOWS IN
THE MID TO UPPER 40S NORTH AND UPPER 40S TO LOWER 50S SOUTH.
TEMPERATURES AND CLOUD COVER BEGIN TO INCREASE ON FRIDAY AS MODERATE
SOUTHEASTERLY FLOW RETURNS. A 500 MB TROUGH/CUTOFF LOW DEVELOPS OVER
NORTHERN MEXICO ON THURSDAY AND SLOWLY NUDGES EAST THROUGH THE
WEEKEND. THE WEAK TROUGH COMBINED WITH THE INCREASED MOISTURE COULD
RESULT IN A FEW STREAMER SHOWERS OVER THE COASTAL WATERS ON SUNDAY.
&&
.MARINE...
NOW THROUGH TUESDAY...A FRONT WILL SWEEP ACROSS THE AREA EARLY
THIS MORNING WITH WINDS SWITCHING TO THE NORTH IN ITS WAKE. STRONG
NORTH WINDS WILL ROUGHEN SEAS AND A SMALL CRAFT ADVISORY HAS BEEN
ISSUED FOR THE GULF OF MEXICO WATERS OF THE LOWER TEXAS COAST
THROUGH MONDAY AFTERNOON. ROUGH SEAS WILL BECOME MORE MODERATE
MONDAY NIGHT INTO AS WIND SPEEDS DECREASE. HOWEVER...A SECONDARY
SURGE OF STRONGER WINDS LOOK TO INVADE AT LEAST THE 20-60NM WATERS
TUESDAY AROUND THE DEPARTING SYSTEM WHICH SMALL CRAFT ADVISORIES
MAY BE NEEDED FOR THE FAR OFFSHORE WATERS FOR SEAS RISING BACK UP
TO AROUND 7 FEET.
TUESDAY NIGHT THROUGH FRIDAY...NORTH WINDS TUESDAY EVENING WILL
BEGIN TO DIMINISH AND SEAS WILL BEGIN TO SUBSIDE AS THE PRESSURE
GRADIENT WEAKENS. SMALL CRAFT ADVISORIES MAY NEEDED TUESDAY NIGHT
FOR THE FAR OFFSHORE WATERS FOR SEAS OF 7 FEET. SEAS WILL CONTINUE
TO SUBSIDE THROUGH THE DAY WEDNESDAY. LIGHT TO MODERATE SOUTHEAST
WINDS AND LOW SEAS WILL PREVAIL THURSDAY AND FRIDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 70 51 70 49 / 0 0 0 0
BROWNSVILLE 72 51 71 45 / 0 0 0 0
HARLINGEN 70 48 71 44 / 0 0 0 0
MCALLEN 71 47 72 43 / 0 0 0 0
RIO GRANDE CITY 71 47 70 42 / 0 0 0 0
SOUTH PADRE ISLAND 70 57 70 54 / 0 0 0 0
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR TXZ251-
254>257.
GM...DENSE FOG ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR GMZ130-
132-135-150-155.
SMALL CRAFT ADVISORY UNTIL 5 PM CST THIS AFTERNOON FOR GMZ150-
155-170-175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55/58/CAMPBELL
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
320 AM CST MON NOV 24 2014
.SHORT TERM (TODAY THROUGH TUESDAY)...COOLER WEATHER ON THE WAY AS
THE COLD FRONT MOVES THROUGH SOUTH TEXAS EARLY THIS MORNING. TOO DRY
NEAR THE SURFACE FOR SHOWERS...AND THAT DRIER AIR IN THE LOWER AND
MID LEVELS REMAINS (MOISTENS UP 700MB AND ABOVE TONIGHT). PRETTY
POTENT UPPER TROUGH AND JET IMPACT AREA OVERNIGHT AND TUESDAY
MORNING...AND MOISTURE 700MB AND ABOVE DUE TO LIFT MAY PRODUCE A
SPRINKLE OR TWO OVER EXTREME EASTERN AREAS AND COASTAL WATERS
(MAINLY CLOUDS THOUGH). HOWEVER...SINCE SPRINKLES WILL NOT MENTION.
WILL GO WITH PARTLY TO MOSTLY CLOUDY SKIES TUESDAY MORNING AS THERE
SHOULD BE SUFFICIENT MID AND HIGH CLOUDS TO PRECLUDE SOME SUN AT
LEAST UNTIL THE AFTERNOON WHEN AREA GETS ON THE SUBSIDENCE SIDE OF
UPPER SYSTEM. AM GOING TO GO ON THE COOLER SIDE OF GUIDANCE FOR
TEMPERATURES TODAY AND TUESDAY...BUT MORE ON THE WARM SIDE FOR
TONIGHT AS MID AND HIGH CLOUDS WILL PREVENT TEMPERATURES FROM
FALLING TOO MUCH. WIND FORECAST GENERALLY A BLEND OF RUC13 AND
NAM12 FOR THE MORNING...THEN A BLEND OF THE NAM AND MOS FOR THE
AFTERNOON THROUGH TUESDAY.
&&
.MARINE (TODAY THROUGH TUESDAY)...WILL ADJUST SCA TO KEEP THE
NEARSHORE IN A BIT LONGER (TIL ABOUT NOON)...AND THE OFFSHORE TIL
ABOUT 5 PM...GIVEN WIND AND WAVE FORECAST. SCA CONDITIONS WILL
LIKELY DEVELOP AGAIN LATE TONIGHT OR TUESDAY. HOWEVER...WILL HOLD
OFF ON HAVING AN SCA FOR THAT AT THIS TIME SINCE 3RD PERIOD AND
WINDS AND WAVES WILL TAPER OFF SOME TONIGHT (AND BORDERLINE SCA AT
THAT). WILL LET NEXT SHIFT TAKE A PEEK AT THIS.
&&
.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...GENERALLY BENIGN
FORECAST THROUGH THE LONG TERM PERIOD...BUT A FEW DETAILS TO
CONSIDER IN THE OVERALL PATTERN. UPPER LEVEL DISTURBANCE PUSHING
EAST OF THE AREA AT ONSET OF LONG TERM PERIOD. SHOULD BE CLEARING
OUT QUICKLY TUESDAY NIGHT...IF NOT ALREADY CLEARED LATE TUESDAY
AFTERNOON. VERY DRY AIR FILTERS IN WITH REINFORCING RIDGE WITH PWATS
WELL BELOW HALF INCH OVER MUCH OF THE AREA. A COUPLE OF WEAK
SHORTWAVES NOTED IN THE UPPER LEVEL PATTERN FRI EVENING AND SUNDAY.
CONFIDENT THAT AIR WILL STILL BE DRY FOR FRIDAY EVENING SHORT
WAVE...BUT SUNDAY WEAK DISTURBANCE COULD HAVE THE POTENTIAL FOR SOME
POPS AS A SOUTHERLY FLOW WILL HAVE DEVELOPED LATE IN THE WEEK. AT
THIS TIME WITH A MAINLY SOUTHERLY FLOW RATHER THAN SOUTHEAST...NOT
THINKING TOO HIGHLY OF SLIGHT CHANCE POPS SOME MODELS ARE
INDICATING. WILL KEEP THE FORECAST DRY AT THIS TIME.
TEMPS FOR THE WEEK SHOULD BE WAVERING AROUND NORMAL FOR HIGHS.
SLIGHTLY BELOW NORMAL LOWS ARE LIKELY EARLY IN THE WEEK WITH HIGH
PRESSURE AND CLEAR SKIES...BUT WILL WARM TO ABOVE NORMAL BY THE
WEEKEND AS MOISTURE GRADUALLY WORKS ITS WAY BACK IN.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 67 45 69 44 70 / 0 0 0 0 0
VICTORIA 65 41 64 41 70 / 0 10 10 0 0
LAREDO 68 48 69 41 73 / 0 0 0 0 0
ALICE 67 43 70 41 72 / 0 0 0 0 0
ROCKPORT 67 48 65 52 69 / 0 10 10 0 0
COTULLA 66 42 67 39 72 / 0 0 0 0 0
KINGSVILLE 68 44 69 42 72 / 0 0 0 0 0
NAVY CORPUS 67 52 68 50 69 / 0 10 10 0 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 1 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: BAYS AND WATERWAYS FROM BAFFIN BAY TO PORT
ARANSAS...COASTAL WATERS FROM BAFFIN BAY TO PORT ARANSAS
OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 5 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
GW/86...SHORT TERM
PZ/83...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS BLACKSBURG VA
100 AM EST MON NOV 24 2014
.SYNOPSIS...
A WARM FRONT EXPECTED TO SHIFT NORTH OF US OVERNIGHT...RESULTING
IN A WARMUP FOR MONDAY...AHEAD OF A COLD FRONT TO OUR WEST. THE COLD
FRONT MOVES THROUGH MONDAY NIGHT INTO TUESDAY...RETURNING
TEMPERATURES TO BELOW NORMAL FOR THE REST OF THE WEEK. A STORM
MOVES ALONG THE SOUTHEAST COAST MIDWEEK WHICH COULD LEAD TO A
WHITE THANKSGIVING FOR SOME.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1257 AM EST MONDAY...
QUICK UPDATE TO DROP THE GOING WIND ADVISORY OVER THE WEST AS
EXPECTING WINDS TO TURN MORE SW SHORTLY WITH SOME DECREASE IN
SPEEDS OVERNIGHT. ALSO WITH THE FAST EXODUS OF THE RAINFALL...CUT
WAY BACK TO JUST LOW POPS FOR THE MOST PART THROUGH MORNING GIVEN
DRYING ALOFT AND LITTLE RESIDUAL FOCUS.
PREVIOUS DISCUSSION AS OF 1020 PM EST SUNDAY...
SHIELD OF RAIN MOVING ACROSS FASTER AND THIS WAS HANDLED FAIRLY
WELL BY THE LATEST RUNS OF THE HRRR AND 18Z LOCAL WRF. WILL DRY
THINGS OUT FASTER THAN EARLIER FORECAST...WITH MODEL SOUNDING
SUGGESTING A SMALL 1-3 HOUR WIND OF DRIZZLE AS DEEPER MOISTURE
PULLS OUT LEAVING BEHIND SHALLOW MOISTURE BELOW 8H. WILL JUST SEE
SPOTTY SHOWERS OVERNIGHT INTO MONDAY MORNING.
AS FOR THE WINDS...THE CORE OF THE 8H JET IS OVERHEAD AND THE FLOW
WILL START TO SHIFT MORE SOUTH THEN SSW AFTER MIDNIGHT. THE ENDING
TIME FOR 1 AM STILL SEEMS REASONABLE. HAVE NOT REALLY HAD ANY
GUSTS OVER 50 MPH...THOUGH THE TAZEWELL MIDDLE SCHOOL WEATHERBUG
SITE DID SHOW A 60 MPH GUST EARLIER.
TEMPS HAVE BUMPED UP IN SOUTHSIDE VA/NW NC PIEDMONT AS WEDGE
DISSIPATES. THE THREAT OF THUNDER LOOKS LIMITED SO REMOVED IT AS
RAIN MOVING OUT SOON.
DRY SLOT AND CLEARING IS PROBLEMATIC BUT THINK THE MOUNTAIN EMPIRE
INTO SE WV AND PORTIONS OF THE NEW RIVER VALLEY AND TN/NC BORDER
AREA WILL SEE SUNSHINE IN THE MORNING WHILE LOW LVL MOISTURE
REMAINS BANKED INTO THE BLUE RIDGE A LITTLE WHILE...AND POINTS
EAST.
PREVIOUS VALID DISCUSSION...
BROAD UPPER LEVEL 500H TROUGH WILL ENCOMPASS MUCH OF THE CENTRAL
CONUS FOR MONDAY TO START THE WORKWEEK. A COLD FRONT WILL APPROACH
FROM THE WEST MONDAY. A WARM SECTOR SOUTHERLY WINDS WILL RESULT IN A
BREEZY MILD MONDAY. 1000-500MB THICKNESS VALUES OF 565-570DM AND
850H TEMPERATURES AROUND PLUS 10C SUPPORT SURFACE TEMPERATURES FROM
AROUND 60 DEGREES IN THE MOUNTAINS TO THE LOWER 70S IN THE PIEDMONT.
THE SURFACE COLD FRONT CROSSES THE MOUNTAINS LATE IN THE DAY... WITH
GFS SOLUTION A LITTLE QUICKER THAN THE NAM/ECMWF.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 338 PM EST SUNDAY...
ON MONDAY NIGHT LOW LEVEL MOISTURE IS BANKED UP AGAINST THE WESTERN
SLOPES OF THE APPALACHIANS. MODELS ERODE LOW LEVEL MOISTURE ON
TUESDAY MORNING.
OVERALL PATTERN THIS TIME FRAME IS FOR SPLIT FLOW WITH AN ACTIVE
NORTHERN STREAM ALONG THE CANADIAN/NORTHERN U.S. BORDER AND SOUTHERN
STREAM THAT HAS A STRONG SHORT WAVE AT THE BASE OF THE TROF OVER THE
LOWER MISSISSIPPI VALLEY BY LATE TUESDAY. EVOLUTION AND TIMING OF
LONG WAVE TROF FROM POSITIVE TILT TO NEGATIVE TILT AND AMOUNT OF
PHASING BETWEEN THE TWO JET STREAMS WILL IMPACT THE RESULTING TRACK
OF THE GULF TO EAST COAST SURFACE LOW AND LOCATION OF THE HEAVIEST
PRECIPITATION. AT THIS TIME SPREAD IN DIFFERENT MODELS IS LARGE.
HIGHEST CONFIDENCE IS WITH THE TIMING BUT MUCH LOWER WITH THE
LOCATION AND TYPE OF PRECIPITATION. WILL BE LEANING TOWARD BLEND OF
THE ECMWF AND GFS AS SUGGESTED BY WPC.
MODELS SHOW MID ATLANTIC REGION IN THE RIGHT REAR QUADRANT OF A 170
KNOT UPPER JET BY LATE TUESDAY NIGHT. AT THE SURFACE THE COLD FRONT
MOVES OFF THE EAST COAST MONDAY NIGHT THEN HIGH PRESSURE BUILDS FROM
THE TENNESSEE VALLEY INTO THE MID ATLANTIC STATES ON TUESDAY. LOW
PRESSURE DEVELOPS IN THE GULF OF MEXICO ON TUESDAY...THEN TRACKS
ACROSS FLORIDA TUESDAY NIGHT. THE LOW SHOULD BE OFF THE SOUTH
CAROLINA COAST ON WEDNESDAY MORNING AS IT MOVES NORTHEAST AND BEGINS
TO DEEPEN.
ONCE THE LOCATION OF THE PRECIPITATION IS DETERMINED...TEMPERATURES
WILL INFLUENCE WHAT TYPE OF PRECIPITATION WILL OCCUR. EVEN TAKING THE
COOLER MET/SREF GUIDANCE FOR TEMPERATURES ON TUESDAY NIGHT AND
WEDNESDAY...SURFACE VALUES MAY STILL BE TOO WARM EAST OF THE BLUE
RIDGE TO SUPPORT ANYTHING BUT RAIN. HAVE USED PARTIAL THICKNESS
VALUES...MAINLY FROM THE GFS/ECMWF TO PLACE RAIN/SNOW LINE. THIS
WILL CHANGE AS THE EVENT DRAWS CLOSER.
LOOKED AT PROBABILITY FOR SNOW AND CORRELATION WITH PAST ANALOG
EVENTS. APPEARS THERE IS AT LEAST THE POTENTIAL FOR SOME WINTER
PRECIPITATION. SINCE WEDNESDAY IS A MAJOR TRAVEL DAY WILL MENTION
POTENTIAL FOR WINTER PRECIPITATION IN THE HAZARDOUS WEATHER
OUTLOOK.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 130 PM EST SUNDAY...
THIS PORTION OF THE FORECAST STARTS WITH THE AFTERMATH OF WHAT
UNFOLDS TUESDAY NIGHT INTO WEDNESDAY EVENING. GIVEN THERE STILL IS
GENEROUS UNCERTAINTY IN THOSE EVENTS...THE EVENTS AFTERWARDS ARE
EQUALLY CHALLENGING. THE GENERAL CONSENSUS IS FOR A LOW/TROUGH TO
DEEPEN ACROSS THE GREAT LAKES/OHIO VALLEY AS THE SYSTEM ALONG THE
COAST HEADS NORTHEAST...AND MAKES WAY FOR THE UPSTREAM SYSTEM TO
ENTER OUR REGION. THE PAST FEW DAYS...GUIDANCE HAS TRANSITIONED THIS
SYSTEM FROM A SLOWER...MORE AMPLIFIED SYSTEM INTO ONE THAT IS MORE
PROGRESSIVE AND THE BULK OF ITS ENERGY REMAINS NORTH OF THE REGION
AS IT MOVES EASTWARD. THAT TREND CONTINUES TODAY. OUR FORECAST WILL
REFLECT LITTLE CHANGE FROM THE PRIOR DURING THE THURSDAY THROUGH
FRIDAY TIMEFRAME. THE HIGHLIGHTS HERE ARE UPSLOPE RAIN/SNOW SHOWERS
ACROSS SOUTHEAST WEST VIRGINIA AND NEIGHBORING COUNTIES OF SOUTHWEST
VIRGINIA. A DECENT NORTHWEST FLOW WILL HELP CLOUDS TO A MINIMUM EAST
OF THE CREST OF THE BLUE RIDGE AND ADD A TOUCH OF A WARMING
INFLUENCE. PARTLY TO MOSTLY CLOUDY SKIES AND COOLER TEMPERATURES
WILL BE THE RULE FOR THE MOUNTAINS.
SATURDAY INTO SUNDAY THE REGION TRANSITIONS INTO MORE OF A ZONAL
PATTERN. THERE IS CONSISTENCY IN EACH MODEL CONCERNING THAT FEATURE.
WHAT VARIES SIGNIFICANTLY IS THE TIMING...TRACK AND SPEED OF A
DISTURBANCE MOVING WITHIN THIS ZONAL FLOW THAT MAY OR MAY NOT IMPACT
OUR REGION. AT THIS TIME...HAVE PLACED THE GREATEST FORECAST WEIGHT
ON A MODEL CONSENSUS THAT OFFERS A SMALL CHANCE OF LIGHT RAIN/SNOW
MAINLY IN THE WESTERN PARTS OF THE AREA SATURDAY NIGHT INTO EARLY
SUNDAY WITH TEMPERATURES TRENDING MILDER OVER THE WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 1150 PM EST SUNDAY...
RAIN HAS MOVED OUT OF THE REGION WITH SPOTTY DRIZZLE AND ISOLATED
SHOWERS REMAINING INTO EARLY MORNING. OVERALL LOOKING AT MVFR/IFR
CIGS WITH LOW LVL WIND SHEAR EARLY ON...THEN LLJ SHIFTS OUT BY
DAWN WITH CIGS STARTING TO LIFT THROUGH LATE MONDAY MORNING AS THE
SFC FLOW TURNS SSW TO SW. GUSTY WINDS AND VFR CIGS SHOULD OCCUR
MOST OF THE DAY MONDAY...WITH WINDS STARTING TO WIND DOWN LATER IN
THE DAY. WITH FRONTAL BOUNDARY MOVING IN CIGS SHOULD BE STAYING
HOVERING NEAR MVFR/VFR HEIGHTS WITH CONFIDENCE LOW AS MODELS VARY
ON DEPTH OF MOISTURE INTO MONDAY EVENING.
EXTENDED DISCUSSION...
WINDS WILL STAY GUSTY MONDAY NIGHT BEHIND COLD FRONT....WITH
POTENTIAL FOR SUB VFR CIGS IN THE MTNS...WHILE VFR IS EXPECTED TO
THE EAST. ANOTHER STORM SYSTEM IS EXPECTED TO MOVE UP THE
SOUTHEAST COAST BY EARLY WEDNESDAY WHICH MAY BRING WINTRY PRECIP
TO THE AREA ALONG WITH SUB VFR AT ALL SITES. LOOKS LIKE FLIGHTS
WILL BE IMPACTED GREATLY ACROSS THE MID ATLANTIC INTO THE
NORTHEAST WITH THIS SYSTEM WITH STRONG WINDS EXPECTED ALONG WITH
WIDESPREAD PRECIPITATION. AROUND HERE LOOKS LIKE WE WILL
EXPERIENCE SUB VFR AT LEAST WED INTO EARLY THANKSGIVING BEFORE
HIGH PRESSURE WORKS IN FROM THE WEST...THOUGH WINDS MAY STAY UP
THROUGH THU NIGHT...WITH UPSLOPE LOWER CIGS AT BLF/LWB.
&&
.EQUIPMENT...
AS OF 215 PM EST FRIDAY...
THE VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WILL BE OUT
OF SERVICE UNTIL PARTS ARRIVE TO REPLACE THE SENSOR. UNTIL THEN
THE VISIBILITY WILL ONLY BE REPORTED WHEN THE CONTROL TOWER IS
STAFFED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...KK/MBS/WP
NEAR TERM...JH/KK/WP
SHORT TERM...AMS
LONG TERM...DS
AVIATION...KK/WP
EQUIPMENT...RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1153 PM EST SUN NOV 23 2014
.SYNOPSIS...
A WARM FRONT EXPECTED TO SHIFT NORTH OF US OVERNIGHT...RESULTING
IN A WARMUP FOR MONDAY...AHEAD OF A COLD FRONT TO OUR WEST. THE COLD
FRONT MOVES THROUGH MONDAY NIGHT INTO TUESDAY...RETURNING
TEMPERATURES TO BELOW NORMAL FOR THE REST OF THE WEEK. A STORM
MOVES ALONG THE SOUTHEAST COAST MIDWEEK WHICH COULD LEAD TO A
WHITE THANKSGIVING FOR SOME.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 1020 PM EST SUNDAY...
SHIELD OF RAIN MOVING ACROSS FASTER AND THIS WAS HANDLED FAIRLY
WELL BY THE LATEST RUNS OF THE HRRR AND 18Z LOCAL WRF. WILL DRY
THINGS OUT FASTER THAN EARLIER FORECAST...WITH MODEL SOUNDING
SUGGESTING A SMALL 1-3 HOUR WIND OF DRIZZLE AS DEEPER MOISTURE
PULLS OUT LEAVING BEHIND SHALLOW MOISTURE BELOW 8H. WILL JUST SEE
SPOTTY SHOWERS OVERNIGHT INTO MONDAY MORNING.
AS FOR THE WINDS...THE CORE OF THE 8H JET IS OVERHEAD AND THE FLOW
WILL START TO SHIFT MORE SOUTH THEN SSW AFTER MIDNIGHT. THE ENDING
TIME FOR 1 AM STILL SEEMS REASONABLE. HAVE NOT REALLY HAD ANY
GUSTS OVER 50 MPH...THOUGH THE TAZEWELL MIDDLE SCHOOL WEATHERBUG
SITE DID SHOW A 60 MPH GUST EARLIER.
TEMPS HAVE BUMPED UP IN SOUTHSIDE VA/NW NC PIEDMONT AS WEDGE
DISSIPATES. THE THREAT OF THUNDER LOOKS LIMITED SO REMOVED IT AS
RAIN MOVING OUT SOON.
DRY SLOT AND CLEARING IS PROBLEMATIC BUT THINK THE MOUNTAIN EMPIRE
INTO SE WV AND PORTIONS OF THE NEW RIVER VALLEY AND TN/NC BORDER
AREA WILL SEE SUNSHINE IN THE MORNING WHILE LOW LVL MOISTURE
REMAINS BANKED INTO THE BLUE RIDGE A LITTLE WHILE...AND POINTS
EAST.
PREVIOUS VALID DISCUSSION...
BROAD UPPER LEVEL 500H TROUGH WILL ENCOMPASS MUCH OF THE CENTRAL
CONUS FOR MONDAY TO START THE WORKWEEK. A COLD FRONT WILL APPROACH
FROM THE WEST MONDAY. A WARM SECTOR SOUTHERLY WINDS WILL RESULT IN A
BREEZY MILD MONDAY. 1000-500MB THICKNESS VALUES OF 565-570DM AND
850H TEMPERATURES AROUND PLUS 10C SUPPORT SURFACE TEMPERATURES FROM
AROUND 60 DEGREES IN THE MOUNTAINS TO THE LOWER 70S IN THE PIEDMONT.
THE SURFACE COLD FRONT CROSSES THE MOUNTAINS LATE IN THE DAY... WITH
GFS SOLUTION A LITTLE QUICKER THAN THE NAM/ECMWF.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 338 PM EST SUNDAY...
ON MONDAY NIGHT LOW LEVEL MOISTURE IS BANKED UP AGAINST THE WESTERN
SLOPES OF THE APPALACHIANS. MODELS ERODE LOW LEVEL MOISTURE ON
TUESDAY MORNING.
OVERALL PATTERN THIS TIME FRAME IS FOR SPLIT FLOW WITH AN ACTIVE
NORTHERN STREAM ALONG THE CANADIAN/NORTHERN U.S. BORDER AND SOUTHERN
STREAM THAT HAS A STRONG SHORT WAVE AT THE BASE OF THE TROF OVER THE
LOWER MISSISSIPPI VALLEY BY LATE TUESDAY. EVOLUTION AND TIMING OF
LONG WAVE TROF FROM POSITIVE TILT TO NEGATIVE TILT AND AMOUNT OF
PHASING BETWEEN THE TWO JET STREAMS WILL IMPACT THE RESULTING TRACK
OF THE GULF TO EAST COAST SURFACE LOW AND LOCATION OF THE HEAVIEST
PRECIPITATION. AT THIS TIME SPREAD IN DIFFERENT MODELS IS LARGE.
HIGHEST CONFIDENCE IS WITH THE TIMING BUT MUCH LOWER WITH THE
LOCATION AND TYPE OF PRECIPITATION. WILL BE LEANING TOWARD BLEND OF
THE ECMWF AND GFS AS SUGGESTED BY WPC.
MODELS SHOW MID ATLANTIC REGION IN THE RIGHT REAR QUADRANT OF A 170
KNOT UPPER JET BY LATE TUESDAY NIGHT. AT THE SURFACE THE COLD FRONT
MOVES OFF THE EAST COAST MONDAY NIGHT THEN HIGH PRESSURE BUILDS FROM
THE TENNESSEE VALLEY INTO THE MID ATLANTIC STATES ON TUESDAY. LOW
PRESSURE DEVELOPS IN THE GULF OF MEXICO ON TUESDAY...THEN TRACKS
ACROSS FLORIDA TUESDAY NIGHT. THE LOW SHOULD BE OFF THE SOUTH
CAROLINA COAST ON WEDNESDAY MORNING AS IT MOVES NORTHEAST AND BEGINS
TO DEEPEN.
ONCE THE LOCATION OF THE PRECIPITATION IS DETERMINED...TEMPERATURES
WILL INFLUENCE WHAT TYPE OF PRECIPITATION WILL OCCUR. EVEN TAKING THE
COOLER MET/SREF GUIDANCE FOR TEMPERATURES ON TUESDAY NIGHT AND
WEDNESDAY...SURFACE VALUES MAY STILL BE TOO WARM EAST OF THE BLUE
RIDGE TO SUPPORT ANYTHING BUT RAIN. HAVE USED PARTIAL THICKNESS
VALUES...MAINLY FROM THE GFS/ECMWF TO PLACE RAIN/SNOW LINE. THIS
WILL CHANGE AS THE EVENT DRAWS CLOSER.
LOOKED AT PROBABILITY FOR SNOW AND CORRELATION WITH PAST ANALOG
EVENTS. APPEARS THERE IS AT LEAST THE POTENTIAL FOR SOME WINTER
PRECIPITATION. SINCE WEDNESDAY IS A MAJOR TRAVEL DAY WILL MENTION
POTENTIAL FOR WINTER PRECIPITATION IN THE HAZARDOUS WEATHER
OUTLOOK.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 130 PM EST SUNDAY...
THIS PORTION OF THE FORECAST STARTS WITH THE AFTERMATH OF WHAT
UNFOLDS TUESDAY NIGHT INTO WEDNESDAY EVENING. GIVEN THERE STILL IS
GENEROUS UNCERTAINTY IN THOSE EVENTS...THE EVENTS AFTERWARDS ARE
EQUALLY CHALLENGING. THE GENERAL CONSENSUS IS FOR A LOW/TROUGH TO
DEEPEN ACROSS THE GREAT LAKES/OHIO VALLEY AS THE SYSTEM ALONG THE
COAST HEADS NORTHEAST...AND MAKES WAY FOR THE UPSTREAM SYSTEM TO
ENTER OUR REGION. THE PAST FEW DAYS...GUIDANCE HAS TRANSITIONED THIS
SYSTEM FROM A SLOWER...MORE AMPLIFIED SYSTEM INTO ONE THAT IS MORE
PROGRESSIVE AND THE BULK OF ITS ENERGY REMAINS NORTH OF THE REGION
AS IT MOVES EASTWARD. THAT TREND CONTINUES TODAY. OUR FORECAST WILL
REFLECT LITTLE CHANGE FROM THE PRIOR DURING THE THURSDAY THROUGH
FRIDAY TIMEFRAME. THE HIGHLIGHTS HERE ARE UPSLOPE RAIN/SNOW SHOWERS
ACROSS SOUTHEAST WEST VIRGINIA AND NEIGHBORING COUNTIES OF SOUTHWEST
VIRGINIA. A DECENT NORTHWEST FLOW WILL HELP CLOUDS TO A MINIMUM EAST
OF THE CREST OF THE BLUE RIDGE AND ADD A TOUCH OF A WARMING
INFLUENCE. PARTLY TO MOSTLY CLOUDY SKIES AND COOLER TEMPERATURES
WILL BE THE RULE FOR THE MOUNTAINS.
SATURDAY INTO SUNDAY THE REGION TRANSITIONS INTO MORE OF A ZONAL
PATTERN. THERE IS CONSISTENCY IN EACH MODEL CONCERNING THAT FEATURE.
WHAT VARIES SIGNIFICANTLY IS THE TIMING...TRACK AND SPEED OF A
DISTURBANCE MOVING WITHIN THIS ZONAL FLOW THAT MAY OR MAY NOT IMPACT
OUR REGION. AT THIS TIME...HAVE PLACED THE GREATEST FORECAST WEIGHT
ON A MODEL CONSENSUS THAT OFFERS A SMALL CHANCE OF LIGHT RAIN/SNOW
MAINLY IN THE WESTERN PARTS OF THE AREA SATURDAY NIGHT INTO EARLY
SUNDAY WITH TEMPERATURES TRENDING MILDER OVER THE WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 1150 PM EST SUNDAY...
RAIN HAS MOVED OUT OF THE REGION WITH SPOTTY DRIZZLE AND ISOLATED
SHOWERS REMAINING INTO EARLY MORNING. OVERALL LOOKING AT MVFR/IFR
CIGS WITH LOW LVL WIND SHEAR EARLY ON...THEN LLJ SHIFTS OUT BY
DAWN WITH CIGS STARTING TO LIFT THROUGH LATE MONDAY MORNING AS THE
SFC FLOW TURNS SSW TO SW. GUSTY WINDS AND VFR CIGS SHOULD OCCUR
MOST OF THE DAY MONDAY...WITH WINDS STARTING TO WIND DOWN LATER IN
THE DAY. WITH FRONTAL BOUNDARY MOVING IN CIGS SHOULD BE STAYING
HOVERING NEAR MVFR/VFR HEIGHTS WITH CONFIDENCE LOW AS MODELS VARY
ON DEPTH OF MOISTURE INTO MONDAY EVENING.
EXTENDED DISCUSSION...
WINDS WILL STAY GUSTY MONDAY NIGHT BEHIND COLD FRONT....WITH
POTENTIAL FOR SUB VFR CIGS IN THE MTNS...WHILE VFR IS EXPECTED TO
THE EAST. ANOTHER STORM SYSTEM IS EXPECTED TO MOVE UP THE
SOUTHEAST COAST BY EARLY WEDNESDAY WHICH MAY BRING WINTRY PRECIP
TO THE AREA ALONG WITH SUB VFR AT ALL SITES. LOOKS LIKE FLIGHTS
WILL BE IMPACTED GREATLY ACROSS THE MID ATLANTIC INTO THE
NORTHEAST WITH THIS SYSTEM WITH STRONG WINDS EXPECTED ALONG WITH
WIDESPREAD PRECIPITATION. AROUND HERE LOOKS LIKE WE WILL
EXPERIENCE SUB VFR AT LEAST WED INTO EARLY THANKSGIVING BEFORE
HIGH PRESSURE WORKS IN FROM THE WEST...THOUGH WINDS MAY STAY UP
THROUGH THU NIGHT...WITH UPSLOPE LOWER CIGS AT BLF/LWB.
&&
.EQUIPMENT...
AS OF 215 PM EST FRIDAY...
THE VISIBILITY SENSOR AT KLYH...LYNCHBURG AIRPORT...WILL BE OUT
OF SERVICE UNTIL PARTS ARRIVE TO REPLACE THE SENSOR. UNTIL THEN
THE VISIBILITY WILL ONLY BE REPORTED WHEN THE CONTROL TOWER IS
STAFFED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR VAZ007-009.
NC...NONE.
WV...WIND ADVISORY UNTIL 1 AM EST MONDAY FOR WVZ042.
&&
$$
SYNOPSIS...KK/MBS/WP
NEAR TERM...KK/WP
SHORT TERM...AMS
LONG TERM...DS
AVIATION...KK/WP
EQUIPMENT...RAB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
342 PM CST MON NOV 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 341 PM CST MON NOV 24 2014
A PROGRESSIVE AND ENERGETIC FLOW PERSISTS OVER THE CONUS THROUGH
THIS WEEK WITH AN EVOLUTION TO MORE OF A ZONAL OR BROAD FLAT RIDGE
IN THE LARGE SCALE. PREDICTABILITY OVER THE PAST WEEKEND HAS BEEN
LOW...AS SEEN BY THE SHORT RANGE VARIABILITY IN HOW THIS CURRENT
SNOW EVENT TRANSPIRED. NOT PRETTY. THIS WILL CONTINUE THROUGH THE
WEEK...AND CONFIDENCE IS LOW IN TIMING AND PLACEMENT OF WEATHER
SYSTEMS.
LATEST SNOW AMOUNTS IN CENTRAL WISCONSIN ARE IN THE 3 TO 5 INCH
RANGE WITH WINDS CAUSING SOME MEASUREMENT DIFFICULTY. RADAR
INDICATING THAT MOST OF THE CENTRAL WI AREA SHOULD CONTINUE TO
DIMINISH IN INTENSITY AS SNOW SHIELD MOVES NORTHEAST. THE LATEST
RAP TRENDS INDICATE A STRENGTHENING 600-700MB WEAK-MODERATE
FRONTOGENESIS BAND WILL DEVELOP N-S OVER CENTRAL WI LATER THIS
AFTERNOON WHICH COULD BUMP THE RATES A BIT ON WEST END OF THE
SCHIELD. BUT...THAT RAP FRONTOGENESIS GUIDANCE IN THE MID-LEVELS
HAS NOT PROVIDED MUCH FOR SENSIBLE SNOW INCREASE OR BANDING FOR
THIS ENVIRONMENT. OVERALL...FROM TRENDS AND WHAT HAS FALLEN...SNOW
WILL SLOWLY SHIFT EAST THIS EVENING...DIMINISHING. HAVE LOWER
STORM TOTAL AMOUNTS IN CENTRAL WISCONSIN...MORE AROUND 4.5 TO 5
INCHES...AND AFTER COLLABORATION WITH MKX...HAVE DOWNGRADED THE
WARNING TO ADVISORY.
WINDS WILL CONTINUE THROUGH THE EVENING TO CAUSE ROADS TO BE
COVERED AND SNOW PLOW CAMS IN NORTHEAST IA SUGGEST THE ROADS ARENT
TOO CLEAN YET. SO...HAVE DECIDED TO LET THE ENTIRE ADVISORY
CONTINUE THROUGH MIDNIGHT.
WATER VAPOR IMAGERY SHOWING A SHORTWAVE TROUGH DROPPING THROUGH MN
AND RADAR INDICATES SOME SNOW SHOWERS THERE. THIS SHOULD NOT
AMOUNT TO MUCH BUT A BRIEF SNOW SHOWER PERIOD AND MAYBE A BIT OF
VSBY REDUCTION /1-2SM/...BUT NOT A HAZARD GENERALLY. HOWEVER AN
AREA EXISTS AHEAD OF THE SHORTWAVE TROUGH IN MN AND THE HIGHER
LEVEL CLOUD WITH THE SNOW SCHIELD THAT IS PROMOTING SOME FZDZ.
THIS IS FROM SERN MN INTO SWRN WI. SHERIFFS HAVE HAD FZDZ IN GRANT
COUNTY...AND EARLIER IN NERN IA. MOST OF THIS FZDZ SHOULD OCCUR
IN THE ADVISORY AREA AND FOR THE NEXT FEW HOURS AS THE DEEP SNOW
SHOWERS MOVING IN WILL SHIFT THE PRECIPITATION TYPE VIA SEEDER-
FEEDER.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM CST MON NOV 24 2014
A FAIRLY TRANQUIL PERIOD FOR THE WEEK REALLY WITH A COLDER THAN
NORMAL PERIOD UNDER THE DEEP LONG WAVE TROUGH....BUT AS THIS
BECOMES MORE ZONAL...THE AREA WILL SEE CYCLES OF WARM ADVECTION
AND PRECIPITATION CHANCES...CYCLONE PASSAGE...AND COLD AIR PUSHES.
THE FIRST SHORTWAVE TROUGH COMES ON WEDNESDAY...A HEAVIER TRAVEL
DAY. THIS SHORTWAVE IS COMING INTO BRITISH COLUMBIA COAST
CURRENTLY ON THE POLEWARD SIDE OF A 155 KT 250 MB JET PER 12Z
RAOBS. A PRETTY VIGOROUS SYSTEM THAT DIGS SOUTHEAST IN THE
LONGWAVE TROUGH. THIS WILL BE A 1-2 INCH SNOW MAKER BUT THE TRACK
IS THE QUESTION. HAVE GENERALLY KEPT THE SAME FORECAST AS PREVIOUS
WITH MOSTLY A SRN MN AND NERN IA SYSTEM. CONFIDENCE ON THE TRACK
IS NOT HIGH YET WITH COMPLEX SYSTEM OVER GREAT LAKES AND TOTAL
ENERGY OVER THE CONUS RIGHT NOW. NEW GFS PARALLEL RUN INTENSIFIES
THE NWRLY FLOW ENERGY MORE AND BRINGS MORE SNOW TO THE NORTH...BUT
IS AN OUTLIER. BEHIND THIS SYSTEM...COLD AIR COMES IN FOR
THANKSGIVING...BUT A QUITE WEATHER DAY.
ANOTHER SYSTEM MOVES IN FRIDAY AND IF MY CONFIDENCE IS LOW ON THE
TRACK FOR WEDNESDAY...FRIDAYS WARM ADVECTION SWATH OF SNOW OR
WINTER MIX IS LOWER. GOOD MEDIUM RANGE GUIDANCE CONSENSUS ON THE
TRACK RIGHT NOW...BUT THAT DOESNT MEAN IT WILL BE CORRECT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1212 PM CST MON NOV 24 2014
BULK OF HEAVIEST SNOW HAS SHIFTED EAST OF THE AIRFIELDS. IN FACT
KRST DEVOID OF SNOW FOR THE TIME BEING. RADAR LOOPS INDICATE THE
BACK EDGE OF THE MAIN SNOW AREA SHOULD PUSH EAST OF KLSE THIS
AFTERNOON...BUT MODEL TRENDS SUGGEST THAT BACK EDGE WILL SLOW OR
EVEN STALL FOR A TIME. MEANWHILE...BRISK NORTHERLY WINDS ON THE
BACK SIDE OF THE SYSTEM WAS SENDING SOME SNOW SOUTHWARD ACROSS MN
AND THAT LOOKS TO MOVE ACROSS THIS AFTERNOON AND EVENING. FOR THE
MOST PART TAFS WERE ISSUED TAKING THESE FACTORS INTO ACCOUNT. BUT
ONE OTHER CONCERN IS THE POTENTIAL FOR FREEZING DRIZZLE. THIS IS
OCCURRING ACROSS PARTS OF EASTERN IA WHERE THE DEEPER CLOUD AND
SUPPLY OF ICE HAS MOVED OUT. FEELING FOR THE TAF LOCATIONS WAS
THAT THIS SHOULD NOT IMPACT THEM AS THE ICE CLOUD SOURCE WOULD
LINGER LONG ENOUGH FOR THE CLOUD INFLUENCE FROM THE NORTHERLY
SOURCE TO ARRIVE. BY TUESDAY MORNING...SKIES SHOULD BE CLEARING
AS THE SYSTEM FINALLY PULLS AWAY.
LAST CONCERN IS BRISK NORTHWEST WIND. EXPECT SPEEDS TO CONTINUE IN
THE 15-20 KT RANGE WITH GUSTS UP AROUND 30KTS THROUGH THE EVENING
BEFORE DIMINISHING AS THE INFLUENCE FROM THE STORM COMPLEX WANES.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ017-
029-032>034-041>044-053>055-061.
MN...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR MNZ088-
096.
IA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR IAZ011-
030.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...MW
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
330 AM CST MON NOV 24 2014
.UPDATE...
ISSUED AT 330 AM CST MON NOV 24 2014
HAVE EXPANDED WINTER WEATHER ADVISORY AND HOISTED A WINTER STORM
WARNING FOR PORTIONS OF THE ARX FORECAST AREA. SEE
WATCH/WARNING/ADVISORY SECTION BELOW.
CURRENTLY...A DEEPENING LOW WAS LOCATED OVER LOWER MICHIGAN WITH
NORTHWEST WINDS ON THE BACKSIDE...STARTING TO DRAW COLDER AIR IN
OVER THE ARX FORECAST AREA. RADAR/SURFACE OBSEVATIONS SHOWING MAINLY
AREAS OF RAIN EAST OF THE MISSISSIPPI RIVER WHILE WEST OF THE
MISSISSIPPI...RAIN WAS CHANGING/HAS MADE THE CHANGE OVER TO SNOW.
WATER VAPOR IMAGERY SHOWING A VERY POTENT MID-LEVEL SHORTWAVE TROUGH
EJECTING NORTHEAST OUT OF NORTHEAST MISSOURI. PLAN ON THIS WAVE
LIFTING NORTHEAST ACROSS WISCONSIN TODAY WITH STRENGTHENING 700-
500MB FRONTOGENESIS. IN ADDITION...BUFKIT SOUNDING/-12 TO -18C OMEGA
FOR GOOD DENDRITIC GROWTH WILL BE BLOSSOMING FOR AREA EAST OF THE
MISSISSIPPI RIVER LATER THIS MORNING THROUGH THE AFTERNOON FOR SOME
GOOD SNOW RATES. COULD SEE SNOW RATES OF 1/2-1 INCH/HR. RIGHT
NOW...LOOKS LIKE AREAS OF CENTRAL WI WOULD BE IMPACTED THE MOST WITH
INDICATIONS OF SNOW TOTALS AROUND 6 INCHES FOR JUNEAU/ADAMS COUNTIES
FROM LATER THIS MORNING INTO TONIGHT. FARTHER WEST...TO THE
MISSISSIPPI RIVER VALLEY...IT APPERAS ANYWHERE FROM 3-5 INCHES OF
ACCUMULATION CAN BE EXPECTED THIS MORNING INTO THIS
EVENING...TAPERING OFF BY MIDNIGHT. WEST OF THE MISSISSIPPI RIVER
VALLEY...WHICH WILL BE DISPLACED FROM THE BETTER STORM
DYNAMICS...PLAN ON SNOW TOTALS TODAY THROUGH THIS EVENING OF 1-2
INCHES. TO COMPLICATE MATTERS LOOKS LIKE GUSTY NORTHWEST WINDS OF 15
TO 25 MPH WITH GUSTS AROUND 35 MPH OVER MORE WIND PRONE AREAS WILL
PRODUCE SOME BLOWING AND DRIFTING OF THE SNOW.
AS SUCH...HOISTED A WINTER STORM WARNING FOR JUNEAU/ADAMS COUNTY IN
CENTRAL WISCONSIN VALID 9 AM TODAY THROUGH 6 AM TUESDAY AND EXPANDED
THE WINTER WEATHER ADVISORY...TO INCLUDE COUNTIES BORDERING THE
MISSISSIPPI UP TO THE WARNING IN CENTRAL WI.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 247 PM CST SUN NOV 23 2014
COMPLEX SHORT TERM PERIOD WITH MANY ISSUES TO DEAL WITH.
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A VERY ACTIVE PATTERN OVER THE WEST HALF OF THE COUNTRY.
UPPER LOWS WERE PRESENT OVER NORTHERN MISSISSIPPI AND NORTH
DAKOTA...WHILE POTENT SHORTWAVES WERE NOTED IN SOUTHWEST OKLAHOMA...
NORTHERN NEW MEXICO AND OVER WASHINGTON STATE. THE FORECAST AREA
LIES IN SOUTHWEST FLOW...WHERE WATER VAPOR IMAGERY SHOWS A NICE WARM
CONVEYOR BELT OVER THE EAST HALF OF THE AREA. THIS TRANSLATES TO A
BAND OF RAIN FROM EASTERN IA THROUGH SOUTHWEST WI TO THE GRB AREA.
RAP PRECIPITABLE WATER VALUES ARE AROUND 1 INCH ALONG AND SOUTH OF
THE BAND...COMPARED TO 0.75 INCHES OVER OUR NORTHWEST CWA WHERE
CONDITIONS ARE DRY. ALTHOUGH ITS DRIER IN PRECIPITABLE WATER...
DRIZZLE AND/OR LIGHT RAIN HAS BEEN PRESENT DUE TO SATURATED LOW
LEVELS AND WEAK ISENTROPIC LIFT ON THE 285-290K SURFACES. TO THE
WEST...A COLD FRONT WAS PRESENT ALONG I-35 WITH A WEAKENING BAND OF
RAIN RIGHT BEHIND IT...ASSOCIATED WITH MID LEVEL FRONTOGENESIS.
TEMPERATURES AHEAD OF THE FRONT ACROSS THE FORECAST AREA WERE MAINLY
IN THE 40S TO LOW 50S...COLDEST OVER THE DEEPER SNOWPACK IN TAYLOR
COUNTY. IN THE WAKE OF THE FRONT...READINGS WERE IN THE 30S AND
40S...UNTIL ONE GETS INTO NORTH DAKOTA BEHIND A SECONDARY COLD FRONT
WHERE READINGS ARE IN THE TEENS AND 20S. LAST ITEM OF NOTE IS THE
SEA LEVEL PRESSURE MAP WHERE A LOW EXISTS NEAR MEMPHIS ON THE NORTH
SIDE OF THE UPPER LOW THERE...ANOTHER LOW WAS OVER NORTHERN MN
AHEAD OF THE NORTH DAKOTA UPPER LOW...AND FINALLY A THIRD LOW WAS
OVER NORTHEAST OKLAHOMA AHEAD OF THE POTENT SHORTWAVES.
MODEL WISE...THERE ARE STILL SOME DIFFERENCES THAT HAVE SIGNIFICANT
FORECAST IMPLICATIONS. MUCH OF THE DIFFERENCES WE HAVE SEEN LATELY
THAT CONTINUE INTO TODAY REVOLVE AROUND HANDLING THOSE POTENT
SHORTWAVES IN SOUTHWEST OKLAHOMA AND NORTHERN NEW MEXICO. THE
STRONGER SURFACE LOW SCENARIOS THAT WOULD IMPACT THE FORECAST AREA
WITH MORE SNOW...LIKE OBSERVED IN THE 23.00Z NAM...BROUGHT THESE
SHORTWAVES INTO NORTHERN IL BY 12Z MONDAY. THOSE SHORTWAVE TRACKS
ALSO SHOWED IN A COUPLED UPPER JET STRUCTURE WITH ANOTHER JET STREAK
OVER ONTARIO AND LAKE SUPERIOR. HOWEVER...THE 23.12Z
NAM/GFS/CANADIAN/ECMWF SUGGEST THESE SHORTWAVES WILL TRACK THROUGH
CENTRAL IL. SO WHAT HAPPENS INSTEAD IS A DOUBLE SURFACE LOW...ONE
ASSOCIATED WITH THE NORTHERN MISSISSIPPI UPPER LOW LIFTING THROUGH
LOWER MI AND A SECOND LOW LIFTING TROUGH NORTHERN IL AT 12Z MONDAY.
WITH THE POTENT SHORTWAVES. THERE STILL ARE THE 2 JET STREAKS...BUT
THEY ARE FAR ENOUGH APART TO PREVENT COUPLING AND THUS PREVENTING A
SINGLE SURFACE LOW. THIS FORECAST LEANS TOWARDS THIS NEWER MODEL
GROUP. EVEN THIS GROUP HAS DIFFERENCES...PRIMARILY WITH THE CANADIAN
PRODUCING A LOT MORE SNOW ON MONDAY AROUND AND EAST OF THE
MISSISSIPPI RIVER.
FOR TONIGHT...THE WARM CONVEYOR BELT / FRONTOGENESIS BAND PRODUCING
THE ONGOING RAIN OVER THE SOUTHEAST HALF OF THE FORECAST AREA
REMAINS POISED TO SHIFT EASTWARD THROUGH THE EVENING. THIS EASTWARD
MOVEMENT IS DUE TO THE UPPER AND SURFACE LOWS NEAR THE MEMPHIS AREA
LIFTING INTO LOWER MICHIGAN. HOWEVER...DRIZZLE AND/OR LIGHT RAIN
SHOULD CONTINUE ELSEWHERE AS SOUNDINGS DEPICT PLENTIFUL LOW TO MID
LEVEL VERTICAL MOTION AND SATURATION...SIMILAR TO WHAT IS GOING ON
NOW. ADDITIONALLY...THAT WEAKENING BAND OF MID-LEVEL FRONTOGENESIS
SEEN ALONG I-35 IS POISED TO GRADUALLY CROSS THE FORECAST AREA WITH
THE SURFACE COLD FRONT...AIDING IN PRECIPITATION GENERATION. IT MAY
NOT BE UNTIL 09Z FOR THE FAR WESTERN FORECAST AREA TO SEE AN END TO
THE PRECIPITATION. NOTE THE TYPE SHOULD BEGIN TO CHANGE OVER TO SNOW
AS COLDER AIR IN THE DAKOTAS GETS PULLED INTO THE FORECAST AREA. ANY
ACCUMULATIONS TONIGHT SHOULD BE VERY LIGHT...DUE TO LATE CHANGE-OVER
TIME AND WARM GROUND...AND CONFINED TO MOSTLY WEST OF THE
MISSISSIPPI RIVER.
FOR MONDAY...ATTENTION FOCUSES ON THE LOW AND POTENT SHORTWAVES
LIFTING THROUGH ILLINOIS AT 12Z MONDAY. THERE IS A STRONG CONSENSUS
FOR PRECIPITATION IN THE WAKE OF THE LOW...CORRELATED WITH A LEFT
EXIT REGION OF A JET STREAK COMING INTO THE OHIO VALLEY.
ADDITIONALLY...A STRONG POCKET OF MID LEVEL FRONTOGENESIS WITH
NEGATIVE EPV ABOVE FOLLOWS IN THE WAKE OF THE LOW. THAT
FRONTOGENESIS STRENGTHENS AS THE COLD AIR FROM THE DAKOTAS MEETS UP
WITH THE POTENT SHORTWAVES LIFTING NORTHEASTWARD...ALSO CAUSING A
SWITCHOVER TO SNOW. CONSENSUS...OUTSIDE OF THE CANADIAN...SUGGESTS
THE HEAVIER SNOW TRACKING THROUGH NORTHERN IL AND SOUTHERN
WI...CLIPPING GRANT AND RICHLAND COUNTIES...POSSIBLY JUNEAU AND
ADAMS TOO. BOTH SNOWFALL AMOUNTS AND BLOWING POTENTIAL ARE GOING TO
BE KEPT DOWN QUITE A BIT WITH SOUNDINGS DEPICTING A DEEP AGGREGATION
LAYER AND ONLY 50 MB OR SO OF DENDRITIC GROWTH ZONE. ADDITIONALLY...
WARM GROUND AND LACK OF SNOW WILL HELP LIMIT BLOWING. IN
COLLABORATION WITH MKX AND DVN...HAVE ISSUED A WINTER WEATHER
ADVISORY FOR GRANT AND RICHLAND. ELSEWHERE...THERE SHOULD STILL BE
SOME LIGHTER SNOW WITH A WEAKER MID LEVEL FRONTOGENESIS ZONE
MARCHING WEST TO EAST...AND DEEP SATURATION. AMOUNTS DO NOT WARRANT
AN ADVISORY ELSEWHERE AT THIS TIME.
IN THE FOG DEPARTMENT...CONDITIONS HAVE YET TO IMPROVE ACROSS
TAYLOR/CLARK COUNTIES. HI RES MODEL VISIBILITY PROGS...WHICH
ARE HANDLING THE FOG THERE WELL...DO NOT SHOW ANY CLEARING UP UNTIL
THE 06-09Z PERIOD WHEN WINDS START TO INCREASE. THEREFORE...HAVE
EXTENDED THE ADVISORY UNTIL 06Z. VISIBILITIES HAVE ALSO BEEN LOW
OVER THE FAR WESTERN FORECAST AREA...THOUGH THESE SHOULD IMPROVE
SOON AS THE WINDS PICK UP. WILL NEED TO KEEP AN EYE ON VISIBILITIES
THROUGH NORTHEAST IOWA AND SOUTHWEST/CENTRAL WI AS THE HEAVIER RAIN
MOVES OUT...WITH SOME SIGNAL THEY COULD DROP TO WARRANT AN ADVISORY.
LASTLY...REGARDING WINDS...SHOULD SEE SUSTAINED SPEEDS OF 15-30 MPH
WITH GUSTS MAYBE UP TO 40 MPH ON MONDAY. DO NOT SEE ANY WIND
ADVISORY NEED AT THIS TIME...THOUGH. THESE NORTHWEST WINDS WILL
RESULT IN A FALLING TEMPERATURE TREND FROM NOW THROUGH MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 247 PM CST SUN NOV 23 2014
NO MATTER WHAT SOLUTION PANS OUT FOR MONDAY...THE TREND CONTINUES TO
BE FOR SNOW TO DIMINISH MONDAY NIGHT AS THE ENTIRE STORM SYSTEM
EXITS EASTWARD INTO QUEBEC. THERE IS SOME UNCERTAINTY ON HOW QUICK
THE SNOW EXITS...MAINLY DUE TO ONE MORE WEAK SHORTWAVE PASSING. WITH
STRATUS LINGERING IN THE DENDRITIC GROWTH ZONE...IT MAKES SENSE TO
CONTINUE TO CARRY PRECIPITATION CHANCES LONGER TOO THAN WHAT MODEL
QPF WOULD SAY FOR ENDING SNOW. BETTER CHANCE FOR CLEARING COMES IN
TUESDAY AS A SURGE OF DRIER...SUBSIDENT AIR COMES IN AHEAD OF A
SURFACE LOW AND SHORTWAVE DROPPING THROUGH THE DAKOTAS. IN FACT...WE
SHOULD GET INTO A WARM ADVECTION REGIME LATER IN THE DAY TO ALLOW
TEMPERATURES TO CLIMB INTO THE MID TO UPPER 20S.
THE SHORTWAVE TROUGH AND SURFACE LOW DROPPING THROUGH THE DAKOTAS
FOR TUESDAY NIGHT AND WEDNESDAY HAS BEEN TRENDING SOUTHWARD IN THE
23.12Z ECMWF...FOLLOWING THE 23.06Z/12Z GFS/NAM. THE 23.12Z CANADIAN
IS ABOUT THE ONLY MODEL NOW WITH THE MORE NORTHERN TRACK. HAVE
ADJUSTED THE FORECAST FOR A MORE SOUTHERN TRACK. DPVA PLUS A SURGE
OF WARM AIR ADVECTION LOOKS TO RESULTS IN A BRIEF BUT HEAVY SNOW
BAND AHEAD OF THE SURFACE LOW. WITH THE SOUTHERN TREND BUT OVERALL
GOOD CONSENSUS TO HAVE THE SNOW BAND...RAISED CHANCES ON WEDNESDAY
TO 60 ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA. MAY GET A
QUICK 1-2 INCHES OUT OF THE BAND...ENOUGH TO IMPACT TRAVEL.
A DRIER BUT COLDER FORECAST IS ON TAP FOR WEDNESDAY NIGHT AND
THANKSGIVING AS ARCTIC HIGH PRESSURE BUILDS INTO THE REGION. 925MB
TEMPS DOWN TO -12 TO -16C SHOULD RESULT IN HIGHS IN THE TEENS TO
MAYBE 20 AT BEST.
THE FORECAST AFTER THANKSGIVING BECAME MUCH MORE UNCERTAIN
TODAY. THERE ARE NOW INDICATIONS OF MORE TROUGHING DIGGING DOWN
THROUGH BRITISH COLUMBIA...WHICH HELPS TO TURN THE UPPER FLOW MORE
ZONAL...AND THUS SEND A WARMER PACIFIC AIRMASS TOWARDS US.
ADDITIONALLY...A WARM FRONT LOOKS TO MOVE THROUGH THE AREA ON
FRIDAY...WHICH COULD PRODUCE A LITTLE SNOW. NOW...THE 23.12Z
GFS/CANADIAN DRIVE A SHORTWAVE THROUGH THE REGION FRIDAY NIGHT AND
ALLOWS ARCTIC AIR TO RETURN FOR THE WEEKEND. THE 23.12Z ECMWF ALLOWS
THIS SHORTWAVE TO STAY FARTHER NORTH...KEEPING THE AREA IN THE WARM
SECTOR. FOR NOW...HAVE STAYED WITH THE CONSENSUS PRIOR TO THE NEW
ECMWF ARRIVAL...BUT THE WEEKEND TEMPS ARE DEFINITELY SUBJECT TO
CHANGE GREATLY. GENERALLY THE WEEKEND LOOKS DRY...THOUGH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1100 PM CST SUN NOV 23 2014
EXPECTING RAIN TO CHANGE OVER TO SNOW BEFORE 08Z FOR KRST...AND
CLOSE TO 12Z FOR KLSE. CIGS WILL REMAIN SUB 1 KFT THROUGH THE
MORNING...WITH A GRADUAL...SMALL BUMP UP FOR THE AFTERNOON/EVENING.
MODELS SUGGESTING A POSSIBLE BRIEF BREAK IN PCPN/INTENSITY/COVERAGE
COULD OCCUR EARLY MORNING...WITH ANOTHER PIECE OF UPPER LEVEL
ENERGY/SFC TROUGH BRINGING ANOTHER ROUND OF LOW VSBY -SN FOR LATE
MORNING/AFTERNOON. IMPACTS WOULD BE FELT MORE AT KLSE. SHOULD SEE
VSBY IMPROVEMENT BY THE EVENING. ACCUMULATIONS UP TO 3 INCHES
POSSIBLE AT KLSE...LESSER AMOUNTS AT KRST.
STRONG AND GUSTY NORTHWEST WINDS WILL PERSIST THROUGH THE DAY AND
INTO THE EVENING HOURS OF MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR WIZ017-
029-032>034-041-042-053>055-061.
WINTER STORM WARNING FROM 9 AM THIS MORNING TO 6 AM CST TUESDAY
FOR WIZ043-044.
MN...WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING UNTIL
MIDNIGHT CST TONIGHT FOR MNZ088-096.
IA...WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING UNTIL
MIDNIGHT CST TONIGHT FOR IAZ011-030.
&&
$$
UPDATE...DAS
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 PM CST SUN NOV 23 2014
.UPDATED...
1100 PM CST SUN NOV 23 2014
DENSE FOG PERSISTING ACROSS NORTHERN WI...AND A GOOD PORTION OF
CENTRAL WI. CHECKING WITH AREA DISPATCHES...VISIBILITY REMAINS POOR
AND TRAVEL CONTINUES TO BE IMPACTED. HAVE OPTED TO EXPAND AND EXTEND
THE DENSE FOG ADVISORY THROUGH 3 AM...AND INCLUDED A CHUNK OF
CENTRAL WI. EXPECT IMPROVEMENT IN THE 2 TO 4 AM TIME FRAME AS A COLD
FRONT SWEEPS IN WITH STRONG NORTHWEST WINDS BEHIND IT.
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 247 PM CST SUN NOV 23 2014
COMPLEX SHORT TERM PERIOD WITH MANY ISSUES TO DEAL WITH.
CURRENTLY AS OF 21Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A VERY ACTIVE PATTERN OVER THE WEST HALF OF THE COUNTRY.
UPPER LOWS WERE PRESENT OVER NORTHERN MISSISSIPPI AND NORTH
DAKOTA...WHILE POTENT SHORTWAVES WERE NOTED IN SOUTHWEST OKLAHOMA...
NORTHERN NEW MEXICO AND OVER WASHINGTON STATE. THE FORECAST AREA
LIES IN SOUTHWEST FLOW...WHERE WATER VAPOR IMAGERY SHOWS A NICE WARM
CONVEYOR BELT OVER THE EAST HALF OF THE AREA. THIS TRANSLATES TO A
BAND OF RAIN FROM EASTERN IA THROUGH SOUTHWEST WI TO THE GRB AREA.
RAP PRECIPITABLE WATER VALUES ARE AROUND 1 INCH ALONG AND SOUTH OF
THE BAND...COMPARED TO 0.75 INCHES OVER OUR NORTHWEST CWA WHERE
CONDITIONS ARE DRY. ALTHOUGH ITS DRIER IN PRECIPITABLE WATER...
DRIZZLE AND/OR LIGHT RAIN HAS BEEN PRESENT DUE TO SATURATED LOW
LEVELS AND WEAK ISENTROPIC LIFT ON THE 285-290K SURFACES. TO THE
WEST...A COLD FRONT WAS PRESENT ALONG I-35 WITH A WEAKENING BAND OF
RAIN RIGHT BEHIND IT...ASSOCIATED WITH MID LEVEL FRONTOGENESIS.
TEMPERATURES AHEAD OF THE FRONT ACROSS THE FORECAST AREA WERE MAINLY
IN THE 40S TO LOW 50S...COLDEST OVER THE DEEPER SNOWPACK IN TAYLOR
COUNTY. IN THE WAKE OF THE FRONT...READINGS WERE IN THE 30S AND
40S...UNTIL ONE GETS INTO NORTH DAKOTA BEHIND A SECONDARY COLD FRONT
WHERE READINGS ARE IN THE TEENS AND 20S. LAST ITEM OF NOTE IS THE
SEA LEVEL PRESSURE MAP WHERE A LOW EXISTS NEAR MEMPHIS ON THE NORTH
SIDE OF THE UPPER LOW THERE...ANOTHER LOW WAS OVER NORTHERN MN
AHEAD OF THE NORTH DAKOTA UPPER LOW...AND FINALLY A THIRD LOW WAS
OVER NORTHEAST OKLAHOMA AHEAD OF THE POTENT SHORTWAVES.
MODEL WISE...THERE ARE STILL SOME DIFFERENCES THAT HAVE SIGNIFICANT
FORECAST IMPLICATIONS. MUCH OF THE DIFFERENCES WE HAVE SEEN LATELY
THAT CONTINUE INTO TODAY REVOLVE AROUND HANDLING THOSE POTENT
SHORTWAVES IN SOUTHWEST OKLAHOMA AND NORTHERN NEW MEXICO. THE
STRONGER SURFACE LOW SCENARIOS THAT WOULD IMPACT THE FORECAST AREA
WITH MORE SNOW...LIKE OBSERVED IN THE 23.00Z NAM...BROUGHT THESE
SHORTWAVES INTO NORTHERN IL BY 12Z MONDAY. THOSE SHORTWAVE TRACKS
ALSO SHOWED IN A COUPLED UPPER JET STRUCTURE WITH ANOTHER JET STREAK
OVER ONTARIO AND LAKE SUPERIOR. HOWEVER...THE 23.12Z
NAM/GFS/CANADIAN/ECMWF SUGGEST THESE SHORTWAVES WILL TRACK THROUGH
CENTRAL IL. SO WHAT HAPPENS INSTEAD IS A DOUBLE SURFACE LOW...ONE
ASSOCIATED WITH THE NORTHERN MISSISSIPPI UPPER LOW LIFTING THROUGH
LOWER MI AND A SECOND LOW LIFTING TROUGH NORTHERN IL AT 12Z MONDAY.
WITH THE POTENT SHORTWAVES. THERE STILL ARE THE 2 JET STREAKS...BUT
THEY ARE FAR ENOUGH APART TO PREVENT COUPLING AND THUS PREVENTING A
SINGLE SURFACE LOW. THIS FORECAST LEANS TOWARDS THIS NEWER MODEL
GROUP. EVEN THIS GROUP HAS DIFFERENCES...PRIMARILY WITH THE CANADIAN
PRODUCING A LOT MORE SNOW ON MONDAY AROUND AND EAST OF THE
MISSISSIPPI RIVER.
FOR TONIGHT...THE WARM CONVEYOR BELT / FRONTOGENESIS BAND PRODUCING
THE ONGOING RAIN OVER THE SOUTHEAST HALF OF THE FORECAST AREA
REMAINS POISED TO SHIFT EASTWARD THROUGH THE EVENING. THIS EASTWARD
MOVEMENT IS DUE TO THE UPPER AND SURFACE LOWS NEAR THE MEMPHIS AREA
LIFTING INTO LOWER MICHIGAN. HOWEVER...DRIZZLE AND/OR LIGHT RAIN
SHOULD CONTINUE ELSEWHERE AS SOUNDINGS DEPICT PLENTIFUL LOW TO MID
LEVEL VERTICAL MOTION AND SATURATION...SIMILAR TO WHAT IS GOING ON
NOW. ADDITIONALLY...THAT WEAKENING BAND OF MID-LEVEL FRONTOGENESIS
SEEN ALONG I-35 IS POISED TO GRADUALLY CROSS THE FORECAST AREA WITH
THE SURFACE COLD FRONT...AIDING IN PRECIPITATION GENERATION. IT MAY
NOT BE UNTIL 09Z FOR THE FAR WESTERN FORECAST AREA TO SEE AN END TO
THE PRECIPITATION. NOTE THE TYPE SHOULD BEGIN TO CHANGE OVER TO SNOW
AS COLDER AIR IN THE DAKOTAS GETS PULLED INTO THE FORECAST AREA. ANY
ACCUMULATIONS TONIGHT SHOULD BE VERY LIGHT...DUE TO LATE CHANGE-OVER
TIME AND WARM GROUND...AND CONFINED TO MOSTLY WEST OF THE
MISSISSIPPI RIVER.
FOR MONDAY...ATTENTION FOCUSES ON THE LOW AND POTENT SHORTWAVES
LIFTING THROUGH ILLINOIS AT 12Z MONDAY. THERE IS A STRONG CONSENSUS
FOR PRECIPITATION IN THE WAKE OF THE LOW...CORRELATED WITH A LEFT
EXIT REGION OF A JET STREAK COMING INTO THE OHIO VALLEY.
ADDITIONALLY...A STRONG POCKET OF MID LEVEL FRONTOGENESIS WITH
NEGATIVE EPV ABOVE FOLLOWS IN THE WAKE OF THE LOW. THAT
FRONTOGENESIS STRENGTHENS AS THE COLD AIR FROM THE DAKOTAS MEETS UP
WITH THE POTENT SHORTWAVES LIFTING NORTHEASTWARD...ALSO CAUSING A
SWITCHOVER TO SNOW. CONSENSUS...OUTSIDE OF THE CANADIAN...SUGGESTS
THE HEAVIER SNOW TRACKING THROUGH NORTHERN IL AND SOUTHERN
WI...CLIPPING GRANT AND RICHLAND COUNTIES...POSSIBLY JUNEAU AND
ADAMS TOO. BOTH SNOWFALL AMOUNTS AND BLOWING POTENTIAL ARE GOING TO
BE KEPT DOWN QUITE A BIT WITH SOUNDINGS DEPICTING A DEEP AGGREGATION
LAYER AND ONLY 50 MB OR SO OF DENDRITIC GROWTH ZONE. ADDITIONALLY...
WARM GROUND AND LACK OF SNOW WILL HELP LIMIT BLOWING. IN
COLLABORATION WITH MKX AND DVN...HAVE ISSUED A WINTER WEATHER
ADVISORY FOR GRANT AND RICHLAND. ELSEWHERE...THERE SHOULD STILL BE
SOME LIGHTER SNOW WITH A WEAKER MID LEVEL FRONTOGENESIS ZONE
MARCHING WEST TO EAST...AND DEEP SATURATION. AMOUNTS DO NOT WARRANT
AN ADVISORY ELSEWHERE AT THIS TIME.
IN THE FOG DEPARTMENT...CONDITIONS HAVE YET TO IMPROVE ACROSS
TAYLOR/CLARK COUNTIES. HI RES MODEL VISIBILITY PROGS...WHICH
ARE HANDLING THE FOG THERE WELL...DO NOT SHOW ANY CLEARING UP UNTIL
THE 06-09Z PERIOD WHEN WINDS START TO INCREASE. THEREFORE...HAVE
EXTENDED THE ADVISORY UNTIL 06Z. VISIBILITIES HAVE ALSO BEEN LOW
OVER THE FAR WESTERN FORECAST AREA...THOUGH THESE SHOULD IMPROVE
SOON AS THE WINDS PICK UP. WILL NEED TO KEEP AN EYE ON VISIBILITIES
THROUGH NORTHEAST IOWA AND SOUTHWEST/CENTRAL WI AS THE HEAVIER RAIN
MOVES OUT...WITH SOME SIGNAL THEY COULD DROP TO WARRANT AN ADVISORY.
LASTLY...REGARDING WINDS...SHOULD SEE SUSTAINED SPEEDS OF 15-30 MPH
WITH GUSTS MAYBE UP TO 40 MPH ON MONDAY. DO NOT SEE ANY WIND
ADVISORY NEED AT THIS TIME...THOUGH. THESE NORTHWEST WINDS WILL
RESULT IN A FALLING TEMPERATURE TREND FROM NOW THROUGH MONDAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 247 PM CST SUN NOV 23 2014
NO MATTER WHAT SOLUTION PANS OUT FOR MONDAY...THE TREND CONTINUES TO
BE FOR SNOW TO DIMINISH MONDAY NIGHT AS THE ENTIRE STORM SYSTEM
EXITS EASTWARD INTO QUEBEC. THERE IS SOME UNCERTAINTY ON HOW QUICK
THE SNOW EXITS...MAINLY DUE TO ONE MORE WEAK SHORTWAVE PASSING. WITH
STRATUS LINGERING IN THE DENDRITIC GROWTH ZONE...IT MAKES SENSE TO
CONTINUE TO CARRY PRECIPITATION CHANCES LONGER TOO THAN WHAT MODEL
QPF WOULD SAY FOR ENDING SNOW. BETTER CHANCE FOR CLEARING COMES IN
TUESDAY AS A SURGE OF DRIER...SUBSIDENT AIR COMES IN AHEAD OF A
SURFACE LOW AND SHORTWAVE DROPPING THROUGH THE DAKOTAS. IN FACT...WE
SHOULD GET INTO A WARM ADVECTION REGIME LATER IN THE DAY TO ALLOW
TEMPERATURES TO CLIMB INTO THE MID TO UPPER 20S.
THE SHORTWAVE TROUGH AND SURFACE LOW DROPPING THROUGH THE DAKOTAS
FOR TUESDAY NIGHT AND WEDNESDAY HAS BEEN TRENDING SOUTHWARD IN THE
23.12Z ECMWF...FOLLOWING THE 23.06Z/12Z GFS/NAM. THE 23.12Z CANADIAN
IS ABOUT THE ONLY MODEL NOW WITH THE MORE NORTHERN TRACK. HAVE
ADJUSTED THE FORECAST FOR A MORE SOUTHERN TRACK. DPVA PLUS A SURGE
OF WARM AIR ADVECTION LOOKS TO RESULTS IN A BRIEF BUT HEAVY SNOW
BAND AHEAD OF THE SURFACE LOW. WITH THE SOUTHERN TREND BUT OVERALL
GOOD CONSENSUS TO HAVE THE SNOW BAND...RAISED CHANCES ON WEDNESDAY
TO 60 ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA. MAY GET A
QUICK 1-2 INCHES OUT OF THE BAND...ENOUGH TO IMPACT TRAVEL.
A DRIER BUT COLDER FORECAST IS ON TAP FOR WEDNESDAY NIGHT AND
THANKSGIVING AS ARCTIC HIGH PRESSURE BUILDS INTO THE REGION. 925MB
TEMPS DOWN TO -12 TO -16C SHOULD RESULT IN HIGHS IN THE TEENS TO
MAYBE 20 AT BEST.
THE FORECAST AFTER THANKSGIVING BECAME MUCH MORE UNCERTAIN
TODAY. THERE ARE NOW INDICATIONS OF MORE TROUGHING DIGGING DOWN
THROUGH BRITISH COLUMBIA...WHICH HELPS TO TURN THE UPPER FLOW MORE
ZONAL...AND THUS SEND A WARMER PACIFIC AIRMASS TOWARDS US.
ADDITIONALLY...A WARM FRONT LOOKS TO MOVE THROUGH THE AREA ON
FRIDAY...WHICH COULD PRODUCE A LITTLE SNOW. NOW...THE 23.12Z
GFS/CANADIAN DRIVE A SHORTWAVE THROUGH THE REGION FRIDAY NIGHT AND
ALLOWS ARCTIC AIR TO RETURN FOR THE WEEKEND. THE 23.12Z ECMWF ALLOWS
THIS SHORTWAVE TO STAY FARTHER NORTH...KEEPING THE AREA IN THE WARM
SECTOR. FOR NOW...HAVE STAYED WITH THE CONSENSUS PRIOR TO THE NEW
ECMWF ARRIVAL...BUT THE WEEKEND TEMPS ARE DEFINITELY SUBJECT TO
CHANGE GREATLY. GENERALLY THE WEEKEND LOOKS DRY...THOUGH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1100 PM CST SUN NOV 23 2014
EXPECTING RAIN TO CHANGE OVER TO SNOW BEFORE 08Z FOR KRST...AND
CLOSE TO 12Z FOR KLSE. CIGS WILL REMAIN SUB 1 KFT THROUGH THE
MORNING...WITH A GRADUAL...SMALL BUMP UP FOR THE AFTERNOON/EVENING.
MODELS SUGGESTING A POSSIBLE BRIEF BREAK IN PCPN/INTENSITY/COVERAGE
COULD OCCUR EARLY MORNING...WITH ANOTHER PIECE OF UPPER LEVEL
ENERGY/SFC TROUGH BRINGING ANOTHER ROUND OF LOW VSBY -SN FOR LATE
MORNING/AFTERNOON. IMPACTS WOULD BE FELT MORE AT KLSE. SHOULD SEE
VSBY IMPROVEMENT BY THE EVENING. ACCUMULATIONS UP TO 3 INCHES
POSSIBLE AT KLSE...LESSER AMOUNTS AT KRST.
STRONG AND GUSTY NORTHWEST WINDS WILL PERSIST THROUGH THE DAY AND
INTO THE EVENING HOURS OF MONDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 3 AM CST MONDAY FOR WIZ017-029-034-
042>044.
WINTER WEATHER ADVISORY FROM 6 AM MONDAY TO MIDNIGHT CST MONDAY
NIGHT FOR WIZ055-061.
MN...NONE.
IA...NONE.
&&
$$
UPDATED......RIECK
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS ALBANY NY
115 AM EST WED NOV 26 2014
.SYNOPSIS...
A COASTAL LOW WILL BRING A WIDESPREAD SNOWFALL TO THE AREA THAT WILL
SIGNIFICANTLY IMPACT HOLIDAY TRAVEL WEDNESDAY AND WEDNESDAY NIGHT.
HEAVY SNOWFALL IS EXPECTED ACROSS WESTERN NEW ENGLAND AND MUCH OF
EASTERN NEW YORK WITH THE HEAVIEST SNOW OCCURRING THE AFTERNOON INTO
THE EVENING. THE SNOW IS EXPECTED TO TAPER LATE WEDNESDAY
NIGHT...WITH SOME LINGERING SNOW SHOWERS ACROSS THE AREA FOR
THANKSGIVING DAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1 AM EST...COLDER AIR CONTINUES TO FILTER IN...HELPING TO
SET THE STAGE FOR A WIDESPREAD SNOWFALL. SATELLITE IMAGERY SHOWING
MID AND HIGH CLOUDS BUILDING NORTH AND NORTHEAST FROM THE
SOUTHEASTERN U.S. AND STRATOCUMULUS EDGING EAST FROM THE GREAT
LAKES. HIGH AND MID LEVEL CLOUDS HAVE OVERSPREAD MUCH OF THE
REGION...OUTSIDE OF A FEW OCCASIONAL THIN SPOTS. SOME MINOR
ADJUSTMENTS TO TEMPERATURES THROUGH DAYBREAK.
WILL BE TRACKING THE NORTHWESTERN EDGE OF THE UPPER DEFORMATION
ZONE DEVELOPING IN THE SOUTHEASTERN U.S. TO GET A FEEL FOR THE
NORTHWESTERN EXTENT OF THE HEAVIEST SNOW AS THE UPPER DEFORMATION
TRACKS TOWARD THE NORTHEASTERN U.S. INTERESTING WATER VAPOR
IMAGERY SHOWS 2 CLOSED UPPER VORTICITY CENTERS LINED UP FROM JUST
NORTH OF THE GREAT LAKES THROUGH EASTERN CANADA...SO WILL THE
EXTENSIVE LINE OF SHEAR ASSOCIATED WITH STRONG UPPER JET ENERGY
ALONG THE EASTERN U.S. HELP THE UPPER DEFORMATION IN THE UPCOMING
STORM TO BECOME A CLOSED VORTICITY CENTER LIKE THE ONES
DOWNSTREAM? IF SO...PERHAPS THE UPCOMING STORM COULD HAVE MORE
UPPER DYNAMICS AND BUILD THE HEAVIER PRECIPITATION FURTHER NORTH.
THAT WOULD BE A BIT DIFFERENT THAN THE OPEN WAVE ALL THE GUIDANCE
SUGGESTS ASSOCIATED WITH THE UPCOMING STORM...BUT JUST HAVE TO
WATCH TRENDS TO REFINE THE FORECAST THROUGH THE NIGHT. LOWS IN
THE 20S NORTH TO LOWER TO MID 30S CENTRAL AND SOUTH.
BASED ON THE LATEST RADAR AND SATELLITE TRENDS AND LATEST HRRR AND
LOCAL WRF...THE ONSET OF THE SNOW COULD BE MORE AROUND SUNRISE
RATHER THAN BEFORE SUNRISE IN SOUTHERN AND CENTRAL AREAS. CLOUDS
WILL ALSO THICKEN AND LOWER TONIGHT. SO...LIGHT PRECIPITATION
SHOULD BEGIN TO MOVE INTO THE CENTRAL AND SOUTHEASTERN
CATSKILLS...MID HUDSON VALLEY...LITCHFIELD COUNTY AND SOUTHERN
BERKSHIRES AROUND SUNRISE WITH SOME MIXED POSSIBLE OF SNOW...RAIN
AND SLEET TO START. SOME MINOR ADJUSTMENTS TO THE FORECASTED
ONSET LATER TONIGHT AND TOMORROW MORNING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES REMAIN IN
EFFECT.
THE HIGHEST SNOWFALL AMOUNTS ARE EXPECTED ACROSS THE WESTERN NEW
ENGLAND...THE TACONICS...THE HIGHER TERRAIN OF THE CENTRAL AND
SOUTHEASTERN CATSKILLS AND PORTIONS OF THE MID HUDSON VALLEY.
AMOUNTS WILL DECREASE AS YOU HEAD NORTHWEST ACROSS THE FORECAST AREA
AWAY FROM THE COASTAL LOW WITH THE GRADIENT BETWEEN WARNING LEVEL
AND ADVISORY LEVEL SNOWFALL EXPECTED TO OCCUR IN THE VICINITY OF THE
SCHOHARIE VALLEY...CAPITAL DISTRICT AND LAKE GEORGE SARATOGA AREA.
THIS IS WHY THE WINTER STORM WATCH WAS IN EFFECT AS LONG AS IT WAS.
MILLER TYPE A COASTAL LOW TAPPING GULF MOISTURE. SOUTHERN STREAM
ENERGY IS INITIATING THE DEVELOPING OF A LOW ALONG THE GULF
COASTAL ALONG A STALLED FRONTAL BOUNDARY. THE LOW WILL TRACK
NORTHEASTWARD AND DEEPEN. THE GUIDANCE HAS COME INTO GOOD
AGREEMENT ON THE TRACK...POSITION AND STRENGTH OF THE STORM
PASSING THE LOW JUST SOUTH OF CAPE COD WEDNESDAY EVENING. THE
DIFFERENCES ARE OCCURRING IN THE QPF. GUIDANCE ALSO CONTINUES TO
INDICATE BANDING WILL OCCUR ESPECIALLY FOR AREAS TO THE SOUTH AND
EAST OF THE CAPITAL DISTRICT HENCE THE HIGHER SNOWFALL FORECAST.
SNOWFALL RATES OF UP TO AN INCH AN HOUR ARE EXPECTED EXPECTED AT
TIMES ACROSS PORTIONS OF THE WARNING AREA WITH AROUND 2 INCHES AN
HOUR POSSIBLE SOUTH AND EAST OF THE CAPITAL DISTRICT WHERE BANDING
IS MORE LIKELY.
SNOW RATIO WILL BE LOWER ACROSS THE MID HUDSON AND NORTHWESTERN
CONNECTICUT AND WITH THE HIGHER TOTALS AND STRONGER WINDS SOME
ISOLATED POWER OUTAGES CAN BE RULED OUT.
APPROACHING NORTHERN STREAM ENERGY DOES NOT PHASE WITH THE
SOUTHERN STREAM KEEPING STORM PROGRESSIVE BUT WILL BRING CHANCES
FOR SNOW SHOWERS TO THE REGION FOR THANKSGIVING DAY AND NIGHT
ESPECIALLY ACROSS THE HIGHER TERRAIN.
LITTLE RECOVERY IN TEMPERATURES WEDNESDAY UPPER 20S TO MID 30S.
MUCH COLDER AIR WILL NOT BE DRAWN INTO THE REGION UNDER AFTER THE
NORTHERN STREAM ENERGY MOVES OFF TO THE EAST.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE LONG TERM PERIOD WILL BE CHARACTERIZED BY PERIODS OF UNSETTLED
WEATHER...AS A SERIES OF FAST-MOVING SYSTEMS IMPACT THE REGION.
AT THE START OF THE LONG TERM PERIOD...IN THE WAKE OF THE COASTAL
STORM THAT IMPACTED THE REGION IN THE SHORT TERM PERIOD...THE
FORECAST AREA WILL BE UNDERNEATH A NORTHWEST FLOW REGIME THAT WILL
GRADUALLY BE DEAMPLIFYING HEADING INTO THE WEEKEND. BY THE
WEEKEND...THE FLOW WILL BECOME QUASI-ZONAL...ALLOWING FOR FAST
PIECES OF NORTHERN STREAM ENERGY TO MOVE THROUGH IT...IN WHICH THE
TIMING AND IMPACTS OF THESE FEATURES COULD CHANGE OVER THE NEXT FEW
DAYS AS MEDIUM-RANGE GUIDANCE OFTEN STRUGGLES HANDLING FAST ZONAL
FLOW. THE FIRST OF THESE PIECES OF ENERGY WILL AFFECT MAINLY AREAS
NORTH AND WEST OF THE CAPITAL REGION THURSDAY NIGHT...AS AN
UPPER-LEVEL SHORTWAVE RACES THROUGH THE NORTHWEST FLOW PROVIDING A
PERIOD OF SCATTERED LIGHT SNOW SHOWERS. ACCUMULATIONS WITH THIS
FEATURE WILL BE LIGHT...ON THE ORDER OF AN INCH OR TWO ACROSS
PORTIONS OF THE SOUTHERN ADIRONDACKS...AND A DUSTING TO PERHAPS AN
INCH ACROSS PORTIONS OF THE MOHAWK VALLEY AND LAKE GEORGE/SARATOGA
REGION.
MUCH OF THE REGION LOOKS TO BE DRY DURING THE DAY FRIDAY...EXCEPT
FOR SOME SCATTERED LAKE EFFECT SNOW SHOWERS THAT MAY SKIRT PORTIONS
OF HERKIMER COUNTY DOWNWIND OF LAKE ONTARIO. THE NEXT SYSTEM LOOKS
TO IMPACT THE REGION FOR MUCH OF THE WEEKEND AS AN AREA OF LOW
PRESSURE TRACKS NORTHEAST FROM THE CENTRAL PLAINS TO THE GREAT
LAKES. OUT AHEAD OF THIS LOW PRESSURE SYSTEM...WARM AIR ADVECTION
PRECIP AHEAD OF AN APPROACHING WARM FRONT MAY ALLOW FOR SCATTERED
RAIN/SNOW SHOWERS SATURDAY INTO SATURDAY NIGHT. NOT MUCH
MOISTURE/DYNAMICS WILL BE PRESENT WITH THIS BOUNDARY AS THE LOW
PRESSURE CENTER WILL BE LIFTING FAR NORTH AND WEST OF THE REGION.
DURING THE DAY SUNDAY...THE WARM FRONT SHOULD LIFT NORTH ACROSS THE
REGION...USHERING IN ANOTHER SHORT PERIOD OF MILD WEATHER WITH
SCATTERED RAIN/SNOW SHOWERS. HIGH PRESSURE LOOKS TO BUILD ACROSS THE
REGION FOR THE START OF NEXT WEEK RESULTING IN A PERIOD OF DRY
WEATHER INTO THE MIDDLE OF NEXT WEEK.
HIGH TEMPERATURES THROUGHOUT THE LONG TERM PERIOD WILL GENERALLY
RANGE FROM THE UPPER 20S TO UPPER 30S...EXCEPT ON SUNDAY WHERE HIGHS
WILL RANGE FROM THE UPPER 30S TO NEAR 50 IN VALLEY AREAS AND LOW 30S
TO MID 40S MONDAY. LOW TEMPERATURES WILL GENERALLY RANGE FROM THE
MID TEENS TO LOW 20S EXCEPT FOR UPPER 20S TO MID 30S SATURDAY AND
SUNDAY NIGHTS.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A DEVELOPING NOR`EASTER WILL BRING A WIDESPREAD SNOWFALL TO THE
AREA THAT WILL SIGNIFICANTLY IMPACT HOLIDAY TRAVEL TODAY INTO
TONIGHT.
PRIOR TO SNOW ARRIVING...VFR CONDITIONS EXPECTED TO PREVAIL THROUGH
12Z AT MOST OF THE TERMINALS. KPOU COULD SEE LIGHT SNOW AND IFR VSBY
DEVELOPING JUST BEFORE 12Z...SO HAVE INCLUDED A TEMPO TO MENTION
THIS STARTING AT 11Z. OTHERWISE CONDITIONS WILL QUICKLY DETERIORATE
TO IFR AS SNOW SPREADS FROM SOUTH TO NORTH BETWEEN 12Z-15Z.
SNOW WILL INCREASE IN INTENSITY BY EARLY TO MID AFTERNOON...WITH
CONDITIONS LIKELY DETERIORATING TO LIFR. SNOW WILL START TO LIGHTEN
IN INTENSITY AFTER 00Z THURSDAY...WITH LIGHT SNOW PERSISTING THROUGH
06Z THURSDAY WITH CONTINUED IFR CONDITIONS.
WINDS WILL BECOME NORTHERLY AROUND 5-10 KTS BY LATER THIS
MORNING...SHIFTING TO THE NORTHWEST THIS EVENING.
OUTLOOK...
WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE SN.
THANKSGIVING DAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SUNDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDROLOGIC PROBLEMS ARE EXPECTED THROUGH THE
WEEKEND.
WIDESPREAD SNOWFALL AS COASTAL LOW IMPACTS REGION WEDNESDAY AND
WEDNESDAY NIGHT. WARMER TEMPERATURES SUNDAY WILL BE SHORT LIVED
AND WILL RESULT SOME SNOW MELT AND RIPENING OF SNOW PACK. HOWEVER
TEMPERATURES ARE EXPECTED TO BE IN THE MID 30S AND COLDER SATURDAY
NIGHT AND SUNDAY NIGHT SO MELT IS STOP.
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...WINTER STORM WARNING FROM 5 AM EARLY THIS MORNING TO 7 AM EST
THURSDAY FOR CTZ001-013.
NY...WINTER STORM WARNING FROM 5 AM EARLY THIS MORNING TO 7 AM EST
THURSDAY FOR NYZ058>061-063>066.
WINTER STORM WARNING FROM 7 AM THIS MORNING TO 7 AM EST
THURSDAY FOR NYZ047>054-084.
WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 7 AM EST
THURSDAY FOR NYZ032-033-038>043-082-083.
MA...WINTER STORM WARNING FROM 5 AM EARLY THIS MORNING TO 7 AM EST
THURSDAY FOR MAZ001-025.
VT...WINTER STORM WARNING FROM 5 AM EARLY THIS MORNING TO 7 AM EST
THURSDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/KL/NAS
SHORT TERM...IAA
LONG TERM...IRL
AVIATION...JPV
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1254 AM EST WED NOV 26 2014
.SYNOPSIS...
A COASTAL LOW WILL BRING A WIDESPREAD SNOWFALL TO THE AREA THAT WILL
SIGNIFICANTLY IMPACT HOLIDAY TRAVEL WEDNESDAY AND WEDNESDAY NIGHT.
HEAVY SNOWFALL IS EXPECTED ACROSS WESTERN NEW ENGLAND AND MUCH OF
EASTERN NEW YORK WITH THE HEAVIEST SNOW OCCURRING THE AFTERNOON INTO
THE EVENING. THE SNOW IS EXPECTED TO TAPER LATE WEDNESDAY
NIGHT...WITH SOME LINGERING SNOW SHOWERS ACROSS THE AREA FOR
THANKSGIVING DAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
COLDER AIR FILTERS IN HELPING TO SET THE STAGE FOR A WIDESPREAD
SNOWFALL. SATELLITE IMAGERY SHOWING MID AND HIGH CLOUDS BUILDING
NORTH AND NORTHEAST FROM THE SOUTHEASTERN U.S. AND STRATOCUMULUS
EDGING EAST FROM THE GREAT LAKES. MOST AREAS SHOULD BE CLOUDY
BEFORE MIDNIGHT...WHICH COULD LIMIT THE COOLING ACROSS THE REGION.
ALTHOUGH...STILL SOME COLD ADVECTION OCCURRING AS WEST LOW LEVEL
WIND FLOW AND COOLING BOUNDARY LAYER TEMPERATURES SPREAD ACROSS
THE REGION THROUGH THE NIGHT. SOME MINOR ADJUSTMENTS TO
TEMPERATURES THROUGH TONIGHT.
WILL BE TRACKING THE NORTHWESTERN EDGE OF THE UPPER DEFORMATION
ZONE DEVELOPING IN THE SOUTHEASTERN U.S. TO GET A FEEL FOR THE
NORTHWESTERN EXTENT OF THE HEAVIEST SNOW AS THE UPPER DEFORMATION
TRACKS TOWARD THE NORTHEASTERN U.S. INTERESTING WATER VAPOR
IMAGERY SHOWS 2 CLOSED UPPER VORTICITY CENTERS LINED UP FROM JUST
NORTH OF THE GREAT LAKES THROUGH EASTERN CANADA...SO WILL THE
EXTENSIVE LINE OF SHEAR ASSOCIATED WITH STRONG UPPER JET ENERGY
ALONG THE EASTERN U.S. HELP THE UPPER DEFORMATION IN THE UPCOMING
STORM TO BECOME A CLOSED VORTICITY CENTER LIKE THE ONES
DOWNSTREAM? IF SO...PERHAPS THE UPCOMING STORM COULD HAVE MORE
UPPER DYNAMICS AND BUILD THE HEAVIER PRECIPITATION FURTHER NORTH.
THAT WOULD BE A BIT DIFFERENT THAN THE OPEN WAVE ALL THE GUIDANCE
SUGGESTS ASSOCIATED WITH THE UPCOMING STORM...BUT JUST HAVE TO
WATCH TRENDS TO REFINE THE FORECAST THROUGH THE NIGHT. LOWS IN
THE 20S NORTH TO LOWER TO MID 30S CENTRAL AND SOUTH.
BASED ON THE LATEST RADAR AND SATELLITE TRENDS AND LATEST HRRR AND
LOCAL WRF...THE ONSET OF THE SNOW COULD BE MORE AROUND SUNRISE
RATHER THAN BEFORE SUNRISE IN SOUTHERN AND CENTRAL AREAS. CLOUDS
WILL ALSO THICKEN AND LOWER TONIGHT. SO...LIGHT PRECIPITATION
SHOULD BEGIN TO MOVE INTO THE CENTRAL AND SOUTHEASTERN
CATSKILLS...MID HUDSON VALLEY...LITCHFIELD COUNTY AND SOUTHERN
BERKSHIRES AROUND SUNRISE WITH SOME MIXED POSSIBLE OF SNOW...RAIN
AND SLEET TO START. SOME MINOR ADJUSTMENTS TO THE FORECASTED
ONSET LATER TONIGHT AND TOMORROW MORNING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES REMAIN IN
EFFECT.
THE HIGHEST SNOWFALL AMOUNTS ARE EXPECTED ACROSS THE WESTERN NEW
ENGLAND...THE TACONICS...THE HIGHER TERRAIN OF THE CENTRAL AND
SOUTHEASTERN CATSKILLS AND PORTIONS OF THE MID HUDSON VALLEY.
AMOUNTS WILL DECREASE AS YOU HEAD NORTHWEST ACROSS THE FORECAST AREA
AWAY FROM THE COASTAL LOW WITH THE GRADIENT BETWEEN WARNING LEVEL
AND ADVISORY LEVEL SNOWFALL EXPECTED TO OCCUR IN THE VICINITY OF THE
SCHOHARIE VALLEY...CAPITAL DISTRICT AND LAKE GEORGE SARATOGA AREA.
THIS IS WHY THE WINTER STORM WATCH WAS IN EFFECT AS LONG AS IT WAS.
MILLER TYPE A COASTAL LOW TAPPING GULF MOISTURE. SOUTHERN STREAM
ENERGY IS INITIATING THE DEVELOPING OF A LOW ALONG THE GULF
COASTAL ALONG A STALLED FRONTAL BOUNDARY. THE LOW WILL TRACK
NORTHEASTWARD AND DEEPEN. THE GUIDANCE HAS COME INTO GOOD
AGREEMENT ON THE TRACK...POSITION AND STRENGTH OF THE STORM
PASSING THE LOW JUST SOUTH OF CAPE COD WEDNESDAY EVENING. THE
DIFFERENCES ARE OCCURRING IN THE QPF. GUIDANCE ALSO CONTINUES TO
INDICATE BANDING WILL OCCUR ESPECIALLY FOR AREAS TO THE SOUTH AND
EAST OF THE CAPITAL DISTRICT HENCE THE HIGHER SNOWFALL FORECAST.
SNOWFALL RATES OF UP TO AN INCH AN HOUR ARE EXPECTED EXPECTED AT
TIMES ACROSS PORTIONS OF THE WARNING AREA WITH AROUND 2 INCHES AN
HOUR POSSIBLE SOUTH AND EAST OF THE CAPITAL DISTRICT WHERE BANDING
IS MORE LIKELY.
SNOW RATIO WILL BE LOWER ACROSS THE MID HUDSON AND NORTHWESTERN
CONNECTICUT AND WITH THE HIGHER TOTALS AND STRONGER WINDS SOME
ISOLATED POWER OUTAGES CAN BE RULED OUT.
APPROACHING NORTHERN STREAM ENERGY DOES NOT PHASE WITH THE
SOUTHERN STREAM KEEPING STORM PROGRESSIVE BUT WILL BRING CHANCES
FOR SNOW SHOWERS TO THE REGION FOR THANKSGIVING DAY AND NIGHT
ESPECIALLY ACROSS THE HIGHER TERRAIN.
LITTLE RECOVERY IN TEMPERATURES WEDNESDAY UPPER 20S TO MID 30S.
MUCH COLDER AIR WILL NOT BE DRAWN INTO THE REGION UNDER AFTER THE
NORTHERN STREAM ENERGY MOVES OFF TO THE EAST.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE LONG TERM PERIOD WILL BE CHARACTERIZED BY PERIODS OF UNSETTLED
WEATHER...AS A SERIES OF FAST-MOVING SYSTEMS IMPACT THE REGION.
AT THE START OF THE LONG TERM PERIOD...IN THE WAKE OF THE COASTAL
STORM THAT IMPACTED THE REGION IN THE SHORT TERM PERIOD...THE
FORECAST AREA WILL BE UNDERNEATH A NORTHWEST FLOW REGIME THAT WILL
GRADUALLY BE DEAMPLIFYING HEADING INTO THE WEEKEND. BY THE
WEEKEND...THE FLOW WILL BECOME QUASI-ZONAL...ALLOWING FOR FAST
PIECES OF NORTHERN STREAM ENERGY TO MOVE THROUGH IT...IN WHICH THE
TIMING AND IMPACTS OF THESE FEATURES COULD CHANGE OVER THE NEXT FEW
DAYS AS MEDIUM-RANGE GUIDANCE OFTEN STRUGGLES HANDLING FAST ZONAL
FLOW. THE FIRST OF THESE PIECES OF ENERGY WILL AFFECT MAINLY AREAS
NORTH AND WEST OF THE CAPITAL REGION THURSDAY NIGHT...AS AN
UPPER-LEVEL SHORTWAVE RACES THROUGH THE NORTHWEST FLOW PROVIDING A
PERIOD OF SCATTERED LIGHT SNOW SHOWERS. ACCUMULATIONS WITH THIS
FEATURE WILL BE LIGHT...ON THE ORDER OF AN INCH OR TWO ACROSS
PORTIONS OF THE SOUTHERN ADIRONDACKS...AND A DUSTING TO PERHAPS AN
INCH ACROSS PORTIONS OF THE MOHAWK VALLEY AND LAKE GEORGE/SARATOGA
REGION.
MUCH OF THE REGION LOOKS TO BE DRY DURING THE DAY FRIDAY...EXCEPT
FOR SOME SCATTERED LAKE EFFECT SNOW SHOWERS THAT MAY SKIRT PORTIONS
OF HERKIMER COUNTY DOWNWIND OF LAKE ONTARIO. THE NEXT SYSTEM LOOKS
TO IMPACT THE REGION FOR MUCH OF THE WEEKEND AS AN AREA OF LOW
PRESSURE TRACKS NORTHEAST FROM THE CENTRAL PLAINS TO THE GREAT
LAKES. OUT AHEAD OF THIS LOW PRESSURE SYSTEM...WARM AIR ADVECTION
PRECIP AHEAD OF AN APPROACHING WARM FRONT MAY ALLOW FOR SCATTERED
RAIN/SNOW SHOWERS SATURDAY INTO SATURDAY NIGHT. NOT MUCH
MOISTURE/DYNAMICS WILL BE PRESENT WITH THIS BOUNDARY AS THE LOW
PRESSURE CENTER WILL BE LIFTING FAR NORTH AND WEST OF THE REGION.
DURING THE DAY SUNDAY...THE WARM FRONT SHOULD LIFT NORTH ACROSS THE
REGION...USHERING IN ANOTHER SHORT PERIOD OF MILD WEATHER WITH
SCATTERED RAIN/SNOW SHOWERS. HIGH PRESSURE LOOKS TO BUILD ACROSS THE
REGION FOR THE START OF NEXT WEEK RESULTING IN A PERIOD OF DRY
WEATHER INTO THE MIDDLE OF NEXT WEEK.
HIGH TEMPERATURES THROUGHOUT THE LONG TERM PERIOD WILL GENERALLY
RANGE FROM THE UPPER 20S TO UPPER 30S...EXCEPT ON SUNDAY WHERE HIGHS
WILL RANGE FROM THE UPPER 30S TO NEAR 50 IN VALLEY AREAS AND LOW 30S
TO MID 40S MONDAY. LOW TEMPERATURES WILL GENERALLY RANGE FROM THE
MID TEENS TO LOW 20S EXCEPT FOR UPPER 20S TO MID 30S SATURDAY AND
SUNDAY NIGHTS.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A DEVELOPING NOR`EASTER WILL BRING A WIDESPREAD SNOWFALL TO THE
AREA THAT WILL SIGNIFICANTLY IMPACT HOLIDAY TRAVEL TODAY INTO
TONIGHT.
PRIOR TO SNOW ARRIVING...VFR CONDITIONS EXPECTED TO PREVAIL THROUGH
12Z AT MOST OF THE TERMINALS. KPOU COULD SEE LIGHT SNOW AND IFR VSBY
DEVELOPING JUST BEFORE 12Z...SO HAVE INCLUDED A TEMPO TO MENTION
THIS STARTING AT 11Z. OTHERWISE CONDITIONS WILL QUICKLY DETERIORATE
TO IFR AS SNOW SPREADS FROM SOUTH TO NORTH BETWEEN 12Z-15Z.
SNOW WILL INCREASE IN INTENSITY BY EARLY TO MID AFTERNOON...WITH
CONDITIONS LIKELY DETERIORATING TO LIFR. SNOW WILL START TO LIGHTEN
IN INTENSITY AFTER 00Z THURSDAY...WITH LIGHT SNOW PERSISTING THROUGH
06Z THURSDAY WITH CONTINUED IFR CONDITIONS.
WINDS WILL BECOME NORTHERLY AROUND 5-10 KTS BY LATER THIS
MORNING...SHIFTING TO THE NORTHWEST THIS EVENING.
OUTLOOK...
WEDNESDAY NIGHT: HIGH OPERATIONAL IMPACT. DEFINITE SN.
THANKSGIVING DAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SATURDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
SUNDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
&&
.HYDROLOGY...
NO SIGNIFICANT HYDROLOGIC PROBLEMS ARE EXPECTED THROUGH THE
WEEKEND.
WIDESPREAD SNOWFALL AS COASTAL LOW IMPACTS REGION WEDNESDAY AND
WEDNESDAY NIGHT. WARMER TEMPERATURES SUNDAY WILL BE SHORT LIVED
AND WILL RESULT SOME SNOW MELT AND RIPENING OF SNOW PACK. HOWEVER
TEMPERATURES ARE EXPECTED TO BE IN THE MID 30S AND COLDER SATURDAY
NIGHT AND SUNDAY NIGHT SO MELT IS STOP.
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...WINTER STORM WARNING FROM 5 AM EARLY THIS MORNING TO 7 AM EST
THURSDAY FOR CTZ001-013.
NY...WINTER STORM WARNING FROM 5 AM EARLY THIS MORNING TO 7 AM EST
THURSDAY FOR NYZ058>061-063>066.
WINTER STORM WARNING FROM 7 AM THIS MORNING TO 7 AM EST
THURSDAY FOR NYZ047>054-084.
WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 7 AM EST
THURSDAY FOR NYZ032-033-038>043-082-083.
MA...WINTER STORM WARNING FROM 5 AM EARLY THIS MORNING TO 7 AM EST
THURSDAY FOR MAZ001-025.
VT...WINTER STORM WARNING FROM 5 AM EARLY THIS MORNING TO 7 AM EST
THURSDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...IAA
NEAR TERM...IAA/NAS
SHORT TERM...IAA
LONG TERM...IRL
AVIATION...JPV
HYDROLOGY...IAA
AREA FORECAST DISCUSSION
NWS MIAMI FL
1241 AM EST WED NOV 26 2014
.AVIATION...MVFR CIGS WILL PREVAIL THROUGH MID MORNING WITH THE
APPROACH AND PASSAGE OF A COLD FRONT. BRIEF PERIODS OF IFR
POSSIBLE. A LINE OF THUNDERSTORMS OVER THE GULF WILL CONTINUE TO
MOVE EASTWARD OVERNIGHT. IT`S HOLDING ITS OWN, SO A BRIEF PERIOD
OF +TSRA WITH IFR OR LIFR ALONG WITH GUSTY WINDS OF 30-40 KT IS
POSSIBLE AS THE LINE MOVES BY...DURING THIS OVERNIGHT AT KAPF AND
TOWARDS DAWN EAST COAST TERMINALS. A FEW SHOWERS COULD IMPACT THE
TERMINALS AHEAD OF THE LINE AS WELL. CIGS WILL IMPROVE DURING THE
LATE MORNING AND BY AFTERNOON WED AT ALL TERMINALS. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 1009 PM EST TUE NOV 25 2014/
UPDATE...
SHOWERS AND STORMS PROGRESSING MUCH SLOWER TO THE SOUTH AND EAST
THAN GUIDANCE PROJECTS, AND THIS HAS BEEN THE CASE FOR SEVERAL
RUNS. THEREFORE HAVE SLOWED CHC AND LIKELY POPS BY ABOUT 6HRS FROM
PREVIOUS FORECAST. ACROSS THE GULF WATERS AND EXTREME NW POPS WERE
LEFT ALONE. WITH THE DEEP WARM, MOIST SOUTHERLY FLOW ACROSS
SOUTH FLORIDA, SHOWERS HAVE DEVELOPED IN THE STRAITS AND PERHAPS
WILL CROSS INTO THE ATLANTIC WATERS AND MIAMI DADE OVER THE NEXT
SEVERAL HOURS ALTHOUGH SCATTERED. WITH THE FRONT CROSSING AT THE
MOST CLIMATOLOGICALLY UNFAVORABLE TIME TOMORROW MORNING, AND THE
MID LEVEL UVV/VORTICITY QUICKLY WEAKENING, NOT EXPECTING MUCH
LIFT WITH THE BOUNDARY TOMORROW MORNING. THIS SEEMS TO BE
REFLECTED IN THE MODELS, WITH QPF QUICKLY DROPPING OFF ACROSS THE
EAST COAST INTO TOMORROW MORNING. ANY CHANCE FOR A STRONGER STORM
WITH DECENT WIND GUSTS WILL REMAIN RESERVED ACROSS THE NW CWA AND
LAKE REGION LATE TONIGHT.
PREV DISCUSSION... /ISSUED 656 PM EST TUE NOV 25 2014/
AVIATION...MVFR CIGS ARE LIKELY TO DEVELOP OVERNIGHT. IFR CIGS
ARE POSSIBLE, BUT LESS CERTAIN. GUIDANCE HAS BEEN TOO AGGRESSIVE
PAST TWO NIGHTS SHOWING IFR TO ONLY NOT OCCUR AT MOST LOCALES.
FOR THIS REASON, WENT WITH PREVAILING MVFR CIGS WITH A SCT005 AND
WILL CLOSELY MONITOR TRENDS.
IMPRESSIVE TROUGH DIGGING INTO THE GULF WITH CONVECTION ALL THE
WAY TO THE YUCATAN. AS THIS SLIDES EAST, THERE IS THE POTENTIAL
FOR A BROKEN LINE OF TSRA TO MOVE THROUGH SOUTH FL. HOWEVER, THE
STORMS IN THE GULF ARE ONLY SLOWLY PROGRESSING EASTWARD AND
POLYGON TIME TRACKING SUGGESTS A LATE NIGHT ARRIVAL AFTER MIDNIGHT
FOR KAPF AND NOT UNTIL DAWN FOR THE EAST COAST. LATEST HRRR RUN
SHOWS NO QPF EAST COAST UNTIL AFTER 10Z. THIS SEEMS REASONABLE
WITH OUR TIMING ANALYSIS, SO HAVE FOLLOWED THIS. IFR OR LIFR
VIS/CIGS ARE POSSIBLE IN ANY HEAVIER TSRA WHICH MOVES THROUGH WITH
IMPACT POTENTIAL HIGHEST FROM 05-09Z AT KAPF AND 09-14Z FOR THE
EAST COAST TERMINALS. GREATEST THREAT KAPF TO KFLL AND POINTS
NORTH. GUST WIND POTENTIAL ~40KT POSSIBLE. ANY SIGNIFICANT IMPACTS
WOULD BE BRIEF THOUGH. THX CWSU MIAMI FOR COLLABORATION! /GREGORIA
PREV DISCUSSION... /ISSUED 356 PM EST TUE NOV 25 2014/
A FEW STRONG STORMS POSSIBLE LAKE OKEECHOBEE/WEST COAST TONIGHT...
ROUGH MARINE CONDITIONS ON WEDNESDAY FOR ALL SOUTH FLORIDA WATERS...
DRIER AND COOLER WEATHER THIS THANKSGIVING WEEKEND...
SHORT TERM... A MID TO UPPER LEVEL TROUGH OF LOW PRESSURE THAT
EXTENDED FROM THE GREAT LAKES SOUTHWEST INTO THE NORTHWEST GULF OF
MEXICO WILL CONTINUE TO MOVE TO THE EAST TONIGHT AND BE LOCATED OVER
THE EASTERN UNITED STATES BY WEDNESDAY MORNING. THIS WILL PUSH HIGH
PRESSURE OVER THE WESTERN ATLANTIC WATERS FURTHER EASTWARD INTO THE
ATLANTIC. LOW PRESSURE OVER THE EASTERN GULF OF MEXICO WILL THEN
MOVE NORTHEAST ALONG THE STATIONARY FRONT THAT IS LOCATED OVER
CENTRAL FLORIDA.
THIS WEATHER PATTERN WILL ALLOW FOR THE SURFACE WINDS TO BECOME MORE
SOUTHWEST OVER SOUTH FLORIDA TONIGHT BRINGING IN THE TROPICAL
MOISTURE FROM THE GULF OF MEXICO INTO SOUTH FLORIDA.
THEREFORE...POPS WILL BE ON AN INCREASE OVER SOUTH FLORIDA TONIGHT
FROM WEST TO EAST...SCATTERED TO NUMEROUS BY LATE TONIGHT WITH THE
HIGHEST POPS OVER THE LAKE OKEECHOBEE REGION AND WEST COAST METRO
AREAS.
THERE IS ALSO A THREAT OF A FEW STRONG STORMS OVER THE LAKE
OKEECHOBEE AND WEST COAST METRO AREAS LATE THIS AFTERNOON INTO
TONIGHT...AS THE LATEST SHORT RANGE MODELS CONTINUE TO INDICATE A
MID LEVEL JET OF 50 KNOTS MOVING THROUGH CENTRAL FLORIDA TONIGHT
ASSOCIATED WITH THE LOW. THE PRIMARY IMPACTS FROM THE STRONG
STORMS WILL BE FREQUENT LIGHTNING STRIKES...GUSTY WINDS...AND HEAVY
RAINFALL THIS AFTERNOON INTO EARLY THIS EVENING.
THE LOW WILL CONTINUE TO MOVE NORTHEAST UP THE EAST COAST OF THE
UNITED STATES ON WEDNESDAY. THIS WILL ALLOW FOR THE STATIONARY
FRONT TO BECOME A COLD FRONT TONIGHT...AND PUSH SOUTHWARD THROUGH
SOUTH FLORIDA WEDNESDAY MORNING BEFORE MOVING INTO THE FLORIDA
KEYS WEDNESDAY AFTERNOON. THEREFORE...THE POPS WILL REMAIN IN THE
SCATTERED TO NUMEROUS RANGE WEDNESDAY MORNING BEFORE DECREASING IN
COVERAGE WEDNESDAY AFTERNOON.
HIGH PRESSURE WILL THEN BUILD INTO THE SOUTHEASTERN UNITED STATES
WEDNESDAY NIGHT THROUGH FRIDAY KEEPING A NORTHERLY WIND FLOW OVER
SOUTH FLORIDA. THIS NORTHERLY WIND FLOW WILL BRING IN DRIER AND
COOLER WEATHER TO SOUTH FLORIDA FOR THANKSGIVING AND FRIDAY.
LOWS WILL BE IN THE 40S OVER MOST OF SOUTH FLORIDA FOR WEDNESDAY
NIGHT AND THURSDAY NIGHT...EXCEPT FOR LOWER TO MID 50S EAST COAST
METRO AREAS. HIGHS WILL BE IN THE LOWER TO MID 70S FOR THANKSGIVING
DAY AND FOR FRIDAY.
LONG TERM...
THE HIGH WILL THEN MOVE SLOWLY EAST INTO THE WESTERN ATLANTIC
WATERS THIS THANKSGIVING WEEKEND ALLOWING FOR THE WINDS TO SLOWLY
SWING TO A EASTERLY DIRECTION AND BECOME BREEZY. THIS WILL KEEP
SOUTH FLORIDA DRY AND ALLOW FOR THE TEMPERATURES TO SLOWLY WARM UP
THROUGH THE WEEKEND...WITH HIGHS IN THE MID TO UPPER 70S AND LOWS IN
THE 50S EXCEPT 60S EAST COAST METRO AREAS.
MARINE...
THE WINDS WILL SWING FROM A SOUTHERLY DIRECTION OF 10 TO 15 KNOTS TONIGHT
TO A NORTHERLY DIRECTION ON WEDNESDAY AND INCREASE QUICKLY TO 20
TO 25 KNOTS WITH GUSTS GETTING CLOSE TO GALE FORCE IN THE OFFSHORE
GULF WATERS. THE NORTHERLY WINDS WILL CONTINUE WEDNESDAY NIGHT
INTO THANKSGIVING DAY AS THE WIND SPEEDS DECREASE TO 15 TO 20
KNOTS.
BOTH THE ATLANTIC AND GULF SEAS WILL REMAIN BELOW 6 FEET TONIGHT
BEFORE INCREASING TO AT LEAST 7 FEET ON WEDNESDAY. THE OFFSHORE
GULF WATERS COULD EVEN GET UP TO 9 TO 11 FEET ON WEDNESDAY.
THEREFORE...IT LOOKS LIKE AN SCA WILL BE NEEDED SOON FOR ALL OF THE
SOUTH FLORIDA WATERS FOR THE WINDS AND SEAS IN THE ATLANTIC AND GULF
WATERS...FOR WEDNESDAY INTO WEDNESDAY NIGHT.
THE THREAT OF RIP CURRENTS WILL ALSO CONTINUE ALONG THE EAST COAST
BEACHES THIS THANKSGIVING WEEKEND AND FOR THE GULF BEACHES OF
SOUTH FLORIDA FOR WEDNESDAY.
FIRE WEATHER... THE RELATIVE HUMIDITY SHOULD FALL BELOW THE 35
PERCENT CRITICAL VALUE ON THANKSGIVING DAY OVER SOUTH FLORIDA DUE TO
DRIER AIR WORKING INTO THE AREA FROM THE NORTH. HOWEVER...THE ERC
WILL REMAIN IN THE UPPER TEENS TO LOWER 20S AND THE 20 FOOT WINDS
WILL REMAIN BELOW 15 MPH ON THANKSGIVING DAY. THEREFORE...NO FIRE
DANGER STATEMENT WILL BE ISSUED FOR SOUTH FLORIDA FOR THANKSGIVING
DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 49 73 51 71 / 10 0 0 10
FORT LAUDERDALE 55 75 56 71 / 10 0 0 10
MIAMI 56 76 57 72 / 10 0 0 10
NAPLES 48 73 50 69 / 0 0 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK FROM 7 AM EST THIS MORNING THROUGH THIS
EVENING FOR FLZ069.
AM...SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 5 PM EST THURSDAY
FOR AMZ650-651-670-671.
GM...SMALL CRAFT ADVISORY FROM 5 AM EARLY THIS MORNING TO 7 PM EST
THIS EVENING FOR GMZ656-657-676.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
1229 AM EST WED NOV 26 2014
.UPDATE...
ISSUED AT 1136 PM EST TUE NOV 25 2014
DID AN UPDATED MAINLY TO FRESHEN UP THE T AND TD GRIDS PER THE LATEST
OBS AND TRENDS. ALSO INCREASED THE SKY COVER SLIGHTLY IN THE FAR
NORTHERN COUNTIES OF THE CWA...BASED ON THE LATEST SATELLITE RETURNS.
CONTINUE TO AGREE WITH PREVIOUS UPDATE AS FAR AS SNOWFALL TOTALS. THE
LATEST NAM12 SEEMS TO HAVE COME IN WITH SLIGHTLY LESS PRECIP THAN
THAT OF THE 18Z RUN...WHICH SEEMS TO ACTUALLY MAKE MORE SENSE GIVEN
THE STRONG UPTICK IN MOISTURE AT 18Z /SEEMS TO HAVE BEEN A LITTLE
ERRONEOUS/. EVEN MORE CONFUSING IS THE LATEST HRRR RUN WHICH IS STILL ONLY
BRINGING PRECIP INTO PIKE AND LETCHER COUNTIES OVERNIGHT...WHILE THE
REMAINDER OF THE CWA REMAINS DRY. THIS SEEMS A BIT EXTREME AS WELL IN
COMPARISON TO THE 6 HOURS MODELS. GIVEN ALL THE UNCERTAINTY...ENDED
UP JUST KEEPING SNOW TOTALS THE SAME. ONCE PRECIP MOVES INTO THE
REGION...THIS WILL BE THE TIME TO ASSESS THE CURRENT CONDITIONS
COMPARED TO THAT OF THE MODEL RUNS...AND ADJUST AMOUNTS /QFP AND
SNOW/ UP OR DOWN AS NEEDED. FORECASTED TEMPERATURES ARE ALREADY
FAIRLY CLOSE TO THE FREEZING LINE. ANY SHIFT A COUPLE DIRECTIONS ONE
WAY OR ANOTHER COULD MEAN THE DIFFERENCE BETWEEN MORE OR LESS SNOW IN
A PARTICULAR LOCATION.
UPDATE ISSUED AT 725 PM EST TUE NOV 25 2014
DID AN UPDATED MAINLY TO FRESHEN UP THE T AND TD GRIDS PER THE LATEST
OBS AND TRENDS. ALSO BUMPED UP THE SKY COVER QUICKER THROUGH THE
EVENING AS HIGH CLOUDS HAVE SPREAD IN QUICKLY FROM THE SOUTHWEST. THE
18Z RUNS HAVE COME IN WITH BEEFIER THOUGHTS ON SNOW AS BOTH THE GFS
AND NAM12 TAKE THE PCPN FURTHER WEST. THE GFS SEEMS TOO WARM AT THE
SFC FOR MUCH SNOW OR ACCUMULATION FOR LOCATIONS OUTSIDE OF OUR
CURRENT ADVISORY WITH ITS LATEST RUN. THE NAM12...ON THE OTHER
HAND...APPEARS TO GO OVERBOARD ON THE QPF AND THEREFORE SNOW OVER OUR
EASTERN COUNTIES. THERE REMAINS PLENTY OF FACTORS THAT WOULD HAMPER
THIS OCCURRENCE WITH CONVECTION TO THE SOUTH CUTTING OFF SOME OF THE
BEST MOISTURE FROM BEING TRANSPORTED INTO KENTUCKY AS CLEANLY AS
ENVISIONED BY THE OFF SYNOPTIC TIME RUN. NEVERTHELESS WILL BE
MONITORING THE RADAR TRENDS AND NEAR TERM MODELS FOR SIGNS THAT THE
CURRENT FORECAST REMAINS ON TRACK. TO THAT THOUGHT...THE LATEST HRRR
RUNS HAVE TRENDED ITS PCPN SHIELD FURTHER TO THE NORTHWEST BUT STILL
A FAR CRY FROM THE 6 HOURLY MODELS. THE UPDATED GRIDS HAVE BEEN SENT
TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 325 PM EST TUE NOV 25 2014
...ACCUMULATING SNOW EXPECTED OVER FAR EASTERN KENTUCKY TONIGHT INTO
WEDNESDAY MORNING...
19Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL INFLUENCING THE WEATHER OF
EASTERN KENTUCKY. THIS HAS PROVIDED PLENTY OF SUNSHINE AND GENERALLY
SOUTHWEST WINDS OF 5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS. THESE
CONDITIONS...ALONG WITH GOOD DRYING THROUGH EARLY AFTERNOON HAS SENT
TEMPERATURES WELL UP INTO THE 50S FOR MOST OF THE AREA...THOUGH
LOCATIONS NORTHWEST OF INTERSTATE 64 ARE LAGGING IN THE UPPER 40S. OF
NOTE ON THE SFC CHART IS AN AREA OF DEVELOPING LOW PRESSURE CROSSING
NORTHERN FLORIDA ON ITS WAY TO THE SOUTHEAST U.S. SEABOARD.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT THROUGH THE FIRST PART
OF THE SHORT TERM FORECAST. THEY ALL TAKE A STRONG SHORTWAVE
CURRENTLY BOTTOMING OUT OVER THE CENTRAL GULF COAST NORTHEAST INTO
THE SOUTHERN APPALACHIANS BY WEDNESDAY MORNING. IN ADDITION...A
COMPACT WAVE WILL BE DROPPING SOUTHEAST FROM THE NORTHERN PLAINS INTO
THE MID MISSISSIPPI VALLEY AND EVENTUALLY THROUGH THE TENNESSEE
VALLEY LATER WEDNESDAY NIGHT. THE MODELS ARE CLOSE ON THE TIMING OF
THIS BUT THE CORE OF THE ENERGY IS FURTHER SOUTH IN THE NAM...
ECMWF...AND GEM WHEN COMPARED TO THE GFS. WILL FAVOR THIS MORE
SOUTHERN TRACK AS SEEN IN THE CONSENSUS. IN GENERAL HAVE LEANED MOST
CLOSELY TO THE HIGHER RESOLUTION MODELS OF THE NAM12 AND HRRR...
THOUGH THE HRRR PCPN FIELDS SEEM TOO FAR SOUTHEAST AND SLOW LATER
TONIGHT.
SENSIBLE WEATHER WILL FEATURE A QUICK INCREASE IN CLOUD COVER FROM
THE SOUTHEAST AS THE COASTAL LOW STARTS TO TAKE SHAPE LATER THIS
EVENING. LOWER CLOUDS AND PCPN WILL START TO SPILL OVER THE SPINE OF
THE APPALACHIANS AND MOVE INTO OUR FAR EASTERN COUNTIES AROUND
MIDNIGHT. EXPECT TEMPERATURES TO WET BULB DOWN WHEN THE PCPN MOVES IN
AND TRANSITION THE RAIN TO SNOW IN THE HIGHER ELEVATIONS FIRST BUT
EVENTUALLY DOWN IN THE VALLEYS...AS WELL. THE HEAVIEST SNOW WILL FALL
IN THE HIGHER TERRAIN ALONG THE VIRGINIA BORDER WHERE AS MUCH AS A
QUARTER TO A THIRD OF AN INCH OF LIQUID WILL LIKELY OCCUR. THIS WILL
PROBABLY AMOUNT TO BETWEEN TWO AND THREE INCHES OF WET SNOW IN THE
HIGHER TERRAIN...ABOVE 2000 FEET AND AROUND AN INCH OR LESS
ELSEWHERE. HIGHER RIDGES BELOW 2000 FEET CAN EXPECT TO PICK UP
BETWEEN ONE AND TWO INCHES BY MIDDAY WEDNESDAY. HAVE SET UP THIS AREA
WITH A WINTER WEATHER ADVISORY FROM MIDNIGHT THROUGH NOON WEDNESDAY
FOR THIS PASSING EVENT. WITH THE POTENTIAL FOR LIGHT ACCUMULATIONS
IN THE COUNTIES IMMEDIATELY WEST OF THE ADVISORY WILL ALSO ISSUE AN
SPS ADDRESSING THIS MARGINAL CONCERN. OTHERWISE...THE COASTAL PULLS
OUT LATER WEDNESDAY WITH A BRIEF VISIT BY HIGH PRESSURE FOR EAST
KENTUCKY IN ITS WAKE. HOWEVER...THE NEXT DEVELOPING LOW WORKS IN FROM
THE NORTHWEST LATER THAT NIGHT CARVING ITS WAY THROUGH OUR SOUTHERN
COUNTIES INTO DAWN THURSDAY. THIS TOO WILL BRING SOME RAIN OR SNOW
TO PARTS OF THE AREA WITH SOME SLUSHY LIGHT SNOW ACCUMULATIONS
POSSIBLE MAINLY ON RIDGES AND GRASSY/ELEVATED SURFACES.
AGAIN USED THE BCCONSSHORT AS A STARTING POINT FOR T/TD/WINDS THROUGH
THE NEXT 24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME
MORE SIGNIFICANT TERRAIN BASED ADJUSTMENTS TONIGHT INTO WEDNESDAY IN
THE EXPECTED SNOW AREAS OF THE FAR EAST. AS FOR POPS...ENDED UP
CLOSE TO A BLEND OF THE MAV AND MET NUMBERS THROUGH THE PERIOD.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 354 PM EST TUE NOV 25 2014
SHORTWAVE ENERGY ROUNDING THE BASE OF THE TROUGH AND ASSOCIATED LOW
PRESSURE WILL BE MOVING EAST OF THE REGION WITH BEST POP CHANCES
ACROSS THE SE PORTIONS OF THE CWA. THIS WILL GENERALLY BE LIGHT
RAIN/SNOW SHOWERS AND DO NOT EXPECT MUCH QPF THROUGH THE DAY THURSDAY
AT THIS POINT. THIS SYSTEM SLIDES EAST ALLOWING FOR NW/W FLOW TO
SETUP ACROSS THE REGION AND THEREFORE HELD SLIGHT CHANCE IN FAR SE
INTO THE AFTERNOON.
SURFACE HIGH PRESSURE WILL SLOWLY SLIDE EAST THROUGH THE NIGHT
THURSDAY AND GENERALLY CRESTING ACROSS THE REGION EARLY FRIDAY. THIS
HIGH PRESSURE BUILDS EAST BRINGING RETURN SOUTHERLY FLOW TO EASTERN
KY WITH TEMPERATURES RISING INTO THE LOWER 50S SATURDAY. SATURDAY
AFTERNOON WE DO PRESENT SOME SLIGHT CHANCE SHOWERS ESPECIALLY ACROSS
THE FAR NORTH AS FRONTAL BOUNDARY GENERALLY STALLS ACROSS THE NORTH.
THIS QUASI-STATIONARY FRONT WILL KEEP THE WEATHER UNSETTLED THROUGH
THE PERIOD. THE QUESTION REALLY BECOMES HOW QUICKLY DOES THIS
BOUNDARY MOVE SOUTH...THAT SAID THE 12Z ECMWF IS MORE PROGRESSIVE
MOVING THIS FRONT SOUTH THAN THE 12Z GFS. RIGHT NOW WITH MODEL
DISCREPANCIES WILL KEEP BLEND POPS FOR THE MOST PART BUT WOULD THINK
THESE POPS WILL CONTINUE TO TREND UP ONCE MODELS COME INTO BETTER
ALIGNMENT. SATURDAY HIGHS ARE EXPECTED TO WARM INTO THE LOW TO MID
50S WITH TEMPERATURES MODIFYING INTO THE UPPER 50S TO LOWER 60S
THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1228 AM EST WED NOV 26 2014
VFR CONDITIONS WILL CONTINUE AT THE TAF SITES THROUGH AROUND 7Z.
AFTER THAT THE AIRPORTS WILL BEGIN TO EXPERIENCES MVFR CIGS AS LOW
LEVEL CLOUD AND PRECIPITATION BEGIN OVERSPREADING THE AREA. RAIN AND
SNOW WILL BE POSSIBLE INITIALLY...BEFORE COLDER AIR MOVES IN ALOFT
AND CHANGES ALL PRECIPITATION OVER TO SNOW. THE SNOW SHOULD BE FAIRLY
LIGHT AT JKL AND SJS. ONCE THE SNOW BEGINS...SOME FOG MAY ALSO FORM
AT JKL AND SJS. THE COMBINATION OF BOTH PHENOMENA COULD LEAD TO
BRIEF PERIODS OF IFR OR EVEN LIFR CONDITIONS AT BOTH AIRPORTS. LOZ
WILL BE ON THE FURTHERS WESTERN EXTEND OF ANY PRECIPITATION...AND
SHOULD SEE MAINLY MVFR CONDITIONS AT WORST IN WHATEVER PRECIPITATION
IS ABLE TO AFFECT THAT AIRPORT. AT THIS TIME...SME LOOKS TO BE IN THE
CLEAR AS FAR AS PRECIPITATION IS CONCERNED...BUT COULD EXPERIENCE
SOME BRIEF PERIODS OF MVFR FOG...ALSO THIS A LOW CONFIDENCE FORECAST.
THE PRECIPITATION SHOULD BE ENDING AT THE AFFECTED AIRPORTS BETWEEN
11 AND 13Z...WITH VFR CONDITIONS EXPECTED THE REST OF THE PERIOD.
CLOUD COVER WILL BE PERSISTENT THROUGHOUT THE DAY TODAY...WITH BROKEN
TO OVERCAST COVERAGE EXPECTED EVEN AFTER THE PRECIPITATION ENDS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR KYZ087-088-110-
113-115-117>120.
&&
$$
UPDATE...JMW
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
1137 PM EST TUE NOV 25 2014
.UPDATE...
ISSUED AT 1136 PM EST TUE NOV 25 2014
DID AN UPDATED MAINLY TO FRESHEN UP THE T AND TD GRIDS PER THE LATEST
OBS AND TRENDS. ALSO INCREASED THE SKY COVER SLIGHTLY IN THE FAR
NORTHERN COUNTIES OF THE CWA...BASED ON THE LATEST SATELLITE RETURNS.
CONTINUE TO AGREE WITH PREVIOUS UPDATE AS FAR AS SNOWFALL TOTALS. THE
LATEST NAM12 SEEMS TO HAVE COME IN WITH SLIGHTLY LESS PRECIP THAN
THAT OF THE 18Z RUN...WHICH SEEMS TO ACTUALLY MAKE MORE SENSE GIVEN
THE STRONG UPTICK IN MOISTURE AT 18Z /SEEMS TO HAVE BEEN A LITTLE
ERRONEOUS/. EVEN MORE CONFUSING IS THE LATEST HRRR RUN WHICH IS STILL ONLY
BRINGING PRECIP INTO PIKE AND LETCHER COUNTIES OVERNIGHT...WHILE THE
REMAINDER OF THE CWA REMAINS DRY. THIS SEEMS A BIT EXTREME AS WELL IN
COMPARISON TO THE 6 HOURS MODELS. GIVEN ALL THE UNCERTAINTY...ENDED
UP JUST KEEPING SNOW TOTALS THE SAME. ONCE PRECIP MOVES INTO THE
REGION...THIS WILL BE THE TIME TO ASSESS THE CURRENT CONDITIONS
COMPARED TO THAT OF THE MODEL RUNS...AND ADJUST AMOUNTS /QFP AND
SNOW/ UP OR DOWN AS NEEDED. FORECASTED TEMPERATURES ARE ALREADY
FAIRLY CLOSE TO THE FREEZING LINE. ANY SHIFT A COUPLE DIRECTIONS ONE
WAY OR ANOTHER COULD MEAN THE DIFFERENCE BETWEEN MORE OR LESS SNOW IN
A PARTICULAR LOCATION.
UPDATE ISSUED AT 725 PM EST TUE NOV 25 2014
DID AN UPDATED MAINLY TO FRESHEN UP THE T AND TD GRIDS PER THE LATEST
OBS AND TRENDS. ALSO BUMPED UP THE SKY COVER QUICKER THROUGH THE
EVENING AS HIGH CLOUDS HAVE SPREAD IN QUICKLY FROM THE SOUTHWEST. THE
18Z RUNS HAVE COME IN WITH BEEFIER THOUGHTS ON SNOW AS BOTH THE GFS
AND NAM12 TAKE THE PCPN FURTHER WEST. THE GFS SEEMS TOO WARM AT THE
SFC FOR MUCH SNOW OR ACCUMULATION FOR LOCATIONS OUTSIDE OF OUR
CURRENT ADVISORY WITH ITS LATEST RUN. THE NAM12...ON THE OTHER
HAND...APPEARS TO GO OVERBOARD ON THE QPF AND THEREFORE SNOW OVER OUR
EASTERN COUNTIES. THERE REMAINS PLENTY OF FACTORS THAT WOULD HAMPER
THIS OCCURRENCE WITH CONVECTION TO THE SOUTH CUTTING OFF SOME OF THE
BEST MOISTURE FROM BEING TRANSPORTED INTO KENTUCKY AS CLEANLY AS
ENVISIONED BY THE OFF SYNOPTIC TIME RUN. NEVERTHELESS WILL BE
MONITORING THE RADAR TRENDS AND NEAR TERM MODELS FOR SIGNS THAT THE
CURRENT FORECAST REMAINS ON TRACK. TO THAT THOUGHT...THE LATEST HRRR
RUNS HAVE TRENDED ITS PCPN SHIELD FURTHER TO THE NORTHWEST BUT STILL
A FAR CRY FROM THE 6 HOURLY MODELS. THE UPDATED GRIDS HAVE BEEN SENT
TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 325 PM EST TUE NOV 25 2014
...ACCUMULATING SNOW EXPECTED OVER FAR EASTERN KENTUCKY TONIGHT INTO
WEDNESDAY MORNING...
19Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL INFLUENCING THE WEATHER OF
EASTERN KENTUCKY. THIS HAS PROVIDED PLENTY OF SUNSHINE AND GENERALLY
SOUTHWEST WINDS OF 5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS. THESE
CONDITIONS...ALONG WITH GOOD DRYING THROUGH EARLY AFTERNOON HAS SENT
TEMPERATURES WELL UP INTO THE 50S FOR MOST OF THE AREA...THOUGH
LOCATIONS NORTHWEST OF INTERSTATE 64 ARE LAGGING IN THE UPPER 40S. OF
NOTE ON THE SFC CHART IS AN AREA OF DEVELOPING LOW PRESSURE CROSSING
NORTHERN FLORIDA ON ITS WAY TO THE SOUTHEAST U.S. SEABOARD.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT THROUGH THE FIRST PART
OF THE SHORT TERM FORECAST. THEY ALL TAKE A STRONG SHORTWAVE
CURRENTLY BOTTOMING OUT OVER THE CENTRAL GULF COAST NORTHEAST INTO
THE SOUTHERN APPALACHIANS BY WEDNESDAY MORNING. IN ADDITION...A
COMPACT WAVE WILL BE DROPPING SOUTHEAST FROM THE NORTHERN PLAINS INTO
THE MID MISSISSIPPI VALLEY AND EVENTUALLY THROUGH THE TENNESSEE
VALLEY LATER WEDNESDAY NIGHT. THE MODELS ARE CLOSE ON THE TIMING OF
THIS BUT THE CORE OF THE ENERGY IS FURTHER SOUTH IN THE NAM...
ECMWF...AND GEM WHEN COMPARED TO THE GFS. WILL FAVOR THIS MORE
SOUTHERN TRACK AS SEEN IN THE CONSENSUS. IN GENERAL HAVE LEANED MOST
CLOSELY TO THE HIGHER RESOLUTION MODELS OF THE NAM12 AND HRRR...
THOUGH THE HRRR PCPN FIELDS SEEM TOO FAR SOUTHEAST AND SLOW LATER
TONIGHT.
SENSIBLE WEATHER WILL FEATURE A QUICK INCREASE IN CLOUD COVER FROM
THE SOUTHEAST AS THE COASTAL LOW STARTS TO TAKE SHAPE LATER THIS
EVENING. LOWER CLOUDS AND PCPN WILL START TO SPILL OVER THE SPINE OF
THE APPALACHIANS AND MOVE INTO OUR FAR EASTERN COUNTIES AROUND
MIDNIGHT. EXPECT TEMPERATURES TO WET BULB DOWN WHEN THE PCPN MOVES IN
AND TRANSITION THE RAIN TO SNOW IN THE HIGHER ELEVATIONS FIRST BUT
EVENTUALLY DOWN IN THE VALLEYS...AS WELL. THE HEAVIEST SNOW WILL FALL
IN THE HIGHER TERRAIN ALONG THE VIRGINIA BORDER WHERE AS MUCH AS A
QUARTER TO A THIRD OF AN INCH OF LIQUID WILL LIKELY OCCUR. THIS WILL
PROBABLY AMOUNT TO BETWEEN TWO AND THREE INCHES OF WET SNOW IN THE
HIGHER TERRAIN...ABOVE 2000 FEET AND AROUND AN INCH OR LESS
ELSEWHERE. HIGHER RIDGES BELOW 2000 FEET CAN EXPECT TO PICK UP
BETWEEN ONE AND TWO INCHES BY MIDDAY WEDNESDAY. HAVE SET UP THIS AREA
WITH A WINTER WEATHER ADVISORY FROM MIDNIGHT THROUGH NOON WEDNESDAY
FOR THIS PASSING EVENT. WITH THE POTENTIAL FOR LIGHT ACCUMULATIONS
IN THE COUNTIES IMMEDIATELY WEST OF THE ADVISORY WILL ALSO ISSUE AN
SPS ADDRESSING THIS MARGINAL CONCERN. OTHERWISE...THE COASTAL PULLS
OUT LATER WEDNESDAY WITH A BRIEF VISIT BY HIGH PRESSURE FOR EAST
KENTUCKY IN ITS WAKE. HOWEVER...THE NEXT DEVELOPING LOW WORKS IN FROM
THE NORTHWEST LATER THAT NIGHT CARVING ITS WAY THROUGH OUR SOUTHERN
COUNTIES INTO DAWN THURSDAY. THIS TOO WILL BRING SOME RAIN OR SNOW
TO PARTS OF THE AREA WITH SOME SLUSHY LIGHT SNOW ACCUMULATIONS
POSSIBLE MAINLY ON RIDGES AND GRASSY/ELEVATED SURFACES.
AGAIN USED THE BCCONSSHORT AS A STARTING POINT FOR T/TD/WINDS THROUGH
THE NEXT 24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE SOME
MORE SIGNIFICANT TERRAIN BASED ADJUSTMENTS TONIGHT INTO WEDNESDAY IN
THE EXPECTED SNOW AREAS OF THE FAR EAST. AS FOR POPS...ENDED UP
CLOSE TO A BLEND OF THE MAV AND MET NUMBERS THROUGH THE PERIOD.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 354 PM EST TUE NOV 25 2014
SHORTWAVE ENERGY ROUNDING THE BASE OF THE TROUGH AND ASSOCIATED LOW
PRESSURE WILL BE MOVING EAST OF THE REGION WITH BEST POP CHANCES
ACROSS THE SE PORTIONS OF THE CWA. THIS WILL GENERALLY BE LIGHT
RAIN/SNOW SHOWERS AND DO NOT EXPECT MUCH QPF THROUGH THE DAY THURSDAY
AT THIS POINT. THIS SYSTEM SLIDES EAST ALLOWING FOR NW/W FLOW TO
SETUP ACROSS THE REGION AND THEREFORE HELD SLIGHT CHANCE IN FAR SE
INTO THE AFTERNOON.
SURFACE HIGH PRESSURE WILL SLOWLY SLIDE EAST THROUGH THE NIGHT
THURSDAY AND GENERALLY CRESTING ACROSS THE REGION EARLY FRIDAY. THIS
HIGH PRESSURE BUILDS EAST BRINGING RETURN SOUTHERLY FLOW TO EASTERN
KY WITH TEMPERATURES RISING INTO THE LOWER 50S SATURDAY. SATURDAY
AFTERNOON WE DO PRESENT SOME SLIGHT CHANCE SHOWERS ESPECIALLY ACROSS
THE FAR NORTH AS FRONTAL BOUNDARY GENERALLY STALLS ACROSS THE NORTH.
THIS QUASI-STATIONARY FRONT WILL KEEP THE WEATHER UNSETTLED THROUGH
THE PERIOD. THE QUESTION REALLY BECOMES HOW QUICKLY DOES THIS
BOUNDARY MOVE SOUTH...THAT SAID THE 12Z ECMWF IS MORE PROGRESSIVE
MOVING THIS FRONT SOUTH THAN THE 12Z GFS. RIGHT NOW WITH MODEL
DISCREPANCIES WILL KEEP BLEND POPS FOR THE MOST PART BUT WOULD THINK
THESE POPS WILL CONTINUE TO TREND UP ONCE MODELS COME INTO BETTER
ALIGNMENT. SATURDAY HIGHS ARE EXPECTED TO WARM INTO THE LOW TO MID
50S WITH TEMPERATURES MODIFYING INTO THE UPPER 50S TO LOWER 60S
THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 700 PM EST TUE NOV 25 2014
VFR CONDITIONS WILL CONTINUE THROUGH THE REST OF THE EVENING THOUGH
CIGS WILL TAKE SHAPE AND START TO LOWER DOWN TO 10K FEET BY
MIDNIGHT. A DEVELOPING LOW PRESSURE SYSTEM WILL SPREAD MOISTURE AND
LOWER CLOUDS OVER EASTERN KENTUCKY LATER TONIGHT...WITH CIGS FALLING
INTO THE MVFR RANGE IN THE EAST BY 08Z. IT STILL LOOKS LIKE WE SHOULD
SEE A GRADIENT IN THOSE LOWER CIGS WITH THE LOWEST (IFR/MVFR) IN THE
EAST...TRAILING BACK TO VFR IN THE WEST...THROUGH MID MORNING
WEDNESDAY. WE WILL ALSO SEE PRECIPITATION SPREAD INTO THE AREA...
MAINLY ACROSS SOUTHEASTERN KENTUCKY...AS A MIX OF RAIN AND
SNOW...LIKELY BECOMING ALL SNOW IN THE PRE-DAWN HOURS. THIS SNOW WILL
RESTRICT VISIBILITIES LATER TONIGHT AS WELL...PARTICULARLY AT KSJS
WHERE VIS COULD BE BELOW A MILE AT TIMES IN THE HEAVIER SNOW BANDS.
THE SNOW AND ANY RESTRICTIONS WILL END FOR THE TAF SITES FROM
SOUTHWEST TO NORTHEAST DURING THE MORNING WEDNESDAY. WINDS WILL BE
LIGHT AND VARIABLE THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON EST WEDNESDAY FOR KYZ087-088-
110-113-115-117>120.
&&
$$
UPDATE...JMW
SHORT TERM...GREIF
LONG TERM...DJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
117 AM EST WED NOV 26 2014
.SYNOPSIS...
LOW PRESSURE SYSTEM IS EXPECTED TO DEVELOP AND RIDE NORTHWARD
ALONG THE COAST ON WEDNESDAY...BRINGING ACCUMULATING SNOW TO AREAS
SOUTH AND EAST OF PITTSBURGH. A SECOND WEAKER SYSTEM WILL USHER IN
COLDER TEMPERATURES AND LINGERING SNOW SHOWER CHANCES THROUGH THE
END OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
THE 00Z KPBZ RAOB INDICATED A VAST DEPTH WITH DEWPOINT DEPRESSIONS
THAT REVEALED A VERITABLE CHASM BETWEEN THE TEMPERATURE AND
DEWPOINT CURVE IN THE VERTICAL. AS SUCH...A DEEP LAYER OF DRY AIR
HAS MADE RESIDENCE OVER THE AREA...WHICH SHOULD ALLOW FOR THE VAST
MAJORITY OF THE CWA TO REMAIN DRY THROUGH THE NIGHTTIME HOURS IN
ADVANCE OF THE SYSTEM ADVANCING NORTHEASTWARD UP THE EASTERN SEABOARD.
WHILE NO CHANGES WERE MADE TO THE FORECAST FOR TOMORROW AT THE
MOMENT...AN EARLY LOOK AT 00Z CANADIAN/GFS/NAM AND 04Z HRRR RUNS
DOES STILL REVEAL SOME RATHER CONCERNING CHARACTERISTICS WITH REGARD
TO THE EVOLUTION OF THE OVERALL PATTERN...PRODUCTION OF
PRECIPITATION FROM THE MODELS THEMSELVES...VAST DISCREPANCIES WITH
WARM ADVECTION...TROUBLE WITH WET BULB PROCESSES...NOT TO MENTION
THE MORE EVERYDAY ISSUES WITH THE TRACK OF THE LOW LEVEL CENTER OF
THE SYSTEM...LOW LEVEL THERMAL FIELDS...AND QPF PLACEMENT. ALL OF
THESE ISSUES WILL HAVE TO BE ADEQUATELY CHEWED THROUGH DURING THE
REMAINDER OF THIS SHIFT...HOWEVER LATER START TIMES DO LOOK BETTER
AT THE MOMENT. AND IT SEEMS FAIRLY CLEAR THAT THE BEST WINDOW FOR
ACCUMULATING SNOW WILL BE RATHER SHORT...AS IN REALLY NOT MUCH
LONGER THAN 6 HOURS ANYWHERE...AND LIKELY ONLY MAYBE 2-3 HOURS IN
PITTSBURGH ITSELF. COMBINING THAT WITH THE SYSTEM MOVING THROUGH
DURING THE DAYTIME WITH WARM GROUND TEMPERATURES AND MARGINAL
BOUNDARY LAYER TEMPERATURES...AND IT SEEMS CLEAR THAT WITHOUT
INTENSE SNOW RATES...ACCUMULATIONS OUTSIDE THE RIDGES MAY BE
TOUGH. THAT SAID...TEMPERATURES BASED UPON CURRENT TRENDS AND WET
BULB PROFILES MAY WELL START OUT THE DAY TOMORROW A BIT LOWER THAN
PREVIOUSLY FORECAST. ALL OF THIS WILL NEED TO BE MULLED INTO THE
FULL UPDATE OF THE FORECAST FOR TODAY A BIT LATER THIS MORNING.
FRIES
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY/...
ANY LINGERING SNOW IN THE FAR EAST THIS EVENING WILL END QUICKLY
AS THE LIFT AND MOISTURE HEAD TOWARD THE COAST WITH THE EXITING
LOW. HUGE DRY SLOT WILL OVERTAKE THE ENTIRE AREA THIS EVENING AND
MIXING HEIGHTS WILL BE WELL BELOW THE DENDRITIC GROWTH ZONE...
ENDING THE ATMOSPHERES ABILITY TO CREATE SNOW. CAA WILL BE GOING
ALL NIGHT...BUT WITH THE LACK OF DEEP MOISTURE AND A RATHER WEAK
AND UNORGANIZED FLOW ALOFT...DO NOT EXPECT ANY SNOW SHOWERS TO
REDEVELOP.
FOR THE MOST PART...THURSDAY MORNING LOOKS DRY AS THE FLOW ALOFT
REMAINS UNORGANIZED AND MIXING HEIGHTS ARE JUST TOO LOW TO REACH
INTO THE SNOW GROWTH ZONE. SHORTWAVE TROUGH WILL SWING THROUGH
LATE THURSDAY...INCREASING LARGE SCALE ASCENSION AND BRINGING ANOTHER
SHOT OF COLDER AIR THURSDAY NIGHT. WINDS ALOFT WILL INCREASE IN
SPEED AND BECOME WEST-NORTHWESTERLY. THE SNOW GROWTH ZONE BEGINS
TO LOWER AND LAKE ERIE WILL COME INTO PLAY. WILL BRING POPS BACK
IN ACROSS THE NORTH AND RIDGES THURSDAY AFTERNOON.
CAA CONTINUES THURSDAY NIGHT BEHIND EXITING SHORTWAVE TROUGH. FOR
A TIME...WINDS ALOFT LOOK GOOD FOR LAKE INFLUENCES AND THE SNOW
GROWTH ZONE WILL DROP INTO AN AREA OF HIGHER SATURATION. EXPECT AN
INCREASE IN SNOW SHOWER COVERAGE THURSDAY NIGHT...WITH THE NORTH
AND RIDGES THE MOST LIKELY LOCATIONS FOR ACCUMULATING SNOW.
SURFACE HIGH WILL BUILD IN ON FRIDAY AND THE ENTIRE ATMOSPHERE
WILL DRY OUT DURING THE MORNING HOURS. COULD SEE SOME LINGERING
FLURRIES ACROSS THE NORTH AND RIDGES FRIDAY MORNING...BUT THESE
TOO WILL END AS SUBSIDENCE AND THE DRIER AIR TAKES OVER.
A COLD DAY FRIDAY WITH TEMPS WELL BELOW SEASONABLE LEVELS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS COMING INTO GOOD AGREEMENT WITH ANOTHER WARM UP FOR THE
WEEKEND. MODELS ARE STILL TRYING TO FIGURE OUT HOW MUCH PRECIP
WILL DEVELOP SATURDAY NIGHT AND SUNDAY WITH PASSING WAVES IN THE
ZONAL FLOW ALOFT. EXPECT MOST OF SATURDAY NIGHT TO BE DRY WITH A
SHOWER POSSIBLE BY SUNDAY MORNING. LOOKING LIKE A BETTER CHANCE
FOR SHOWERS SUNDAY...PARTICULARLY IN THE AFTERNOON...AHEAD OF AN
APPROACHING COLD FRONT.
AREA WILL DRY OUT MONDAY WITH ANOTHER COOL DOWN ON TUESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS SHOULD CONTINUE UNTIL DAWN AT MOST SITES. SNOW WILL
ADVANCE NORTH-NORTHWESTWARD THROUGH THE MORNING HOURS AND AFFECT
MOST SITES OTHER THAN KZZV IN THE EARLY AFTERNOON. SOME
DETERIORATION TO IFR IS LIKELY GENERALLY EAST OF KPIT DURING THE
HEAVIEST WINDOW OF SNOW...HOWEVER THE WINDOW FOR ACCUMULATION AT
ALL SITES OTHER THAN KMGW SHOULD BE FAIRLY BRIEF. AS SNOW SHUTS
OFF BY EVENING...ABUNDANT LOW LEVEL MOISTURE SHOULD ALLOW FOR
STRATUS TO REMAIN A FIXTURE AT MOST SITES. FRIES
OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
PERIODIC RSTRNS ARE PSBL THRU THE WKEND WITH SVRL FAST MOVG
DISTURBANCES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR MDZ001.
OH...NONE.
PA...WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR PAZ074-
076.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR PAZ023-
073-075.
WV...WINTER STORM WARNING UNTIL 6 PM EST THIS EVENING FOR WVZ023-
041.
WINTER WEATHER ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ021-
022.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1258 AM EST WED NOV 26 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 450 PM EST TUE NOV 25 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN AMPLIFIED PATTERN OVER
NAMERICA WITH RIDGING ALONG/JUST OFF THE W COAST...A TROF EXTENDING
FROM N OF HUDSON BAY TO TX AND A RIDGE JUST OFF THE EAST COAST.
SHORTWAVE THAT PROVIDED WIDESPREAD SYNOPTIC SNOW AS WELL AS LAKE
ENHANCED SNOW ACROSS THE FCST AREA LAST NIGHT HAS SHIFTED NE INTO
QUEBEC. UPSTREAM...NEXT SHORTWAVE IS DIVING SE INTO THE DAKOTAS. A
LESS DEFINED SHORTWAVE TROF IS FARTHER N OVER NRN PORTIONS OF
MANITOBA/SASKATCHEWAN. DRYING AIR MASS...LOWERING INVERSION AND LOW
LEVEL WINDS BECOMING MORE ANTICYCLONIC WITH SFC HIGH PRES THAT IS
NOW NOSING INTO WRN UPPER MI HAVE RESULTED IN A STEADY DIMINISHING
TREND/SHIFTING OF LINGERING LES THIS AFTN. IN FACT...OVER THE
W...THERE MAY NOT BE MUCH MORE THAN SCT FLURRIES REMAINING. LAKE
EFFECT CLOUD COVER IS ALSO DIMINISHING WITH CLR SKIES NOW BEING
NOTED AROUND KIWD. TO THE W...CLOUDS IN ADVANCE OF AFOREMENTIONED
SHORTWAVES ARE SLOWLY MOVING ACROSS NRN MN.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LES TRENDS TONIGHT...MIN
TEMPS TONIGHT WITH A PROBABLE PERIOD OF CLR/PARTLY CLOUDY SKIES IN
MANY AREAS AND THEN NEXT ROUND OF HEAVIER LES THAT WILL BEGIN TO
ENTER THE PICTURE WED AFTN AS SHORTWAVE TROF SWINGS SE TOWARD THE
UPPER LAKES.
TONIGHT...ARRIVAL OF WEAK SFC HIGH PRES RIDGE COMBINED WITH
STRENGTHENING LAND BREEZES WILL CONTINUE TO SHIFT LINGERING LES
OFFSHORE. OVER THE E...SHIFTING LES SHOULD BE OFFSHORE NO LATER THAN
AROUND MIDNIGHT. OVER THE W...ALTHOUGH THERE IS PROBABLY NOT MUCH
MORE THAN FLURRIES CURRENTLY REMAINING...NOCTURNAL COOLING AND LAND
BREEZE DEVELOPMENT RESULTING IN INCREASING CONVERGENCE SHOULD FAVOR
SOME REDEVELOPMENT OF LES DURING THE NIGHT. AMONG THE HIGH RES
MODELS...THERE IS DISAGREEMENT IN WHETHER SE MOVING SFC TROF WILL
SINK FAR ENOUGH S TO KEEP LES OVER THE KEWEENAW. AT THIS POINT...
BELIEVE SW FLOW ENHANCED BY LAND BREEZE WILL PUSH LES OFFSHORE...BUT
THERE IS ENOUGH UNCERTAINTY TO MAINTAIN SOME SCT -SHSN WORDING OVER
THE NRN PORTION OF THE KEWEENAW OVERNIGHT. AS FOR TEMPS...BASED ON
SATELLITE IMAGERY...IT LOOKS LIKE THERE WILL BE A DECENT PERIOD OF
CLEAR TO PARTLY CLOUDY SKIES TONIGHT OVER MUCH OF THE AREA. WITH
LIGHT WINDS AND PRECIPITABLE WATER 40-55PCT OF NORMAL...FAVORED THE
LOW END OF GUIDANCE. TEMPS SHOULD PLUMMET RAPIDLY THIS EVENING WHERE
SKIES ARE CLEAR...AND EXPECT TRADITIONAL COLD SPOTS TO FALL TO
AROUND -5F. HOWEVER...GIVEN THE SLOW ADVANCE OF UPSTREAM CLOUDS...
CLOUDS MAY BE SLOWER TO ARRIVE THAN CURRENTLY FCST. COMBINED WITH
FRESH SNOW COVER...COULD EASILY SEE TEMPS FALL TO -10F OR LWR IN THE
USUAL COLD SPOTS.
SHORTWAVE CURRENTLY MOVING INTO THE DAKOTAS WILL CONTINUE TO DROP SE
TOWARD THE TENNESSEE VALLEY TONIGHT/WED AND WILL HAVE NO INFLUENCE
HERE AS IT PASSES WELL S OF UPPER MI. OF CONCERN IS THE FOLLOWING
SHORTWAVE TROF WHICH WILL SWING SE AND EXTEND FROM JAMES BAY TO MN
BY 00Z THU. AS HEIGHT FALLS/MODEST DEEP LAYER FORCING PER QVECTORS
OVERSPREAD THE RELATIVELY WARM WATERS OF LAKE SUPERIOR...SFC TROF
MOVING OVER THE LAKE WILL SHARPEN UP...RESULTING IN INCREASING
CONVERGENCE AND INTENSIFYING LAKE ENHANCED SNOW ALONG/NEAR TROF.
EXPECT THIS TROF TO REACH THE KEWEENAW DURING THE MORNING AND THE W
IN THE AFTN. TROF PROBABLY WON`T REACH NCNTRL UPPER MI UNTIL
EVENING. NE ORIENTATION OF THE WINDS ACROSS THE KEWEENAW AFTER
TROF PASSAGE WON`T BE ESPECIALLY FAVORABLE FOR PERSISTENT HEAVIER
LAKE ENHANCED SNOW AFTER THE MAIN MDT/HVY SNOW BAND ALONG TROF
SHIFTS S. FARTHER S...SHARPER LOW-LEVEL CONVERGENCE AND BETTER
UPSLOPING IS EXPECTED INTO ONTONAGON/GOGEBIC COUNTIES...AND THIS IS
INDICATED IN MODEL GUIDANCE IN LOW-LEVEL OMEGA FIELDS. WIND FLOW
SUGGESTS LAKE NIPIGON PRECONDITONING WILL ALSO COME INTO PLAY OVER
THE FAR W. WITH THESE FAVORABLE CONDITIONS CONTINUING INTO THE WED
NIGHT...WILL HOIST A LAKE EFFECT SNOW ADVISORY FOR ONTONAGON/GOGEBIC
STARTING AT 20Z WED. IN GENERAL...A QUICK COUPLE OF INCHES OF SNOW
WILL PROBABLY OCCUR AS THE TROF MOVES ONSHORE OVER THE W.
ELSEWHERE...SOME -SN SHOULD GRADUALLY OVERSPREAD THE REST OF WRN
UPPER MI IN THE AFTN. TO THE E...IT APEARS WINDS WILL BACK
SUFFICIENTLY TO BRING SOME LES OFF LAKE MICHIGAN INTO THE FAR ERN
FCST AREA IN THE AFTN. WINDS ARE LIGHT/CONVERGENCE WEAK...SO NOT
EXPECTING MUCH WITH THE LES OFF LAKE MI WED (LESS THAN 1 INCH).
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 457 PM EST TUE NOV 25 2014
MAIN FCST CONCERNS IN THE LONG TERM WL FOCUS ON LES POTENTIAL FOR
WED NIGHT INTO THANKSGIVING AND NEED FOR HEADLINES AT SENSITIVE
TRAVEL TIME. ANOTHER ROUND OF SN WL BE POSSIBLE ON FRI/FRI NIGHT
WITH DVLPG ISENTROPIC ASCENT UNDER AN UPPER AIR PATTERN THAT WL
SHIFT TO A PROGRESSIVE...ZONAL FLOW BY THE WEEKEND. WELL BLO NORMAL
TEMPS WITH SOME RECORD LO MAX TEMPS ON THANKSGIVING WL GIVE WAY TO
MUCH WARMER WX ON SAT. ALTHOUGH SOME COLDER AIR WL RETURN FOR SUN
INTO MON...A WARMER SW FLOW ON THE WRN FLANK OF HI PRES SHIFTING TO
THE E WILL DVLP ON TUE UNDER THIS PROGRESSIVE PATTERN.
WED NGT...STEADY N BACKING NNW WIND IN THE WAKE OF PASSING NRN
STREAM SHRTWV IS FCST TO ADVECT COLDER AIR INTO THE UPR LKS WITH H85
TEMPS FALLING AS LO AS -18C OVER THE KEWEENAW BY 12Z THU...A FVRBL
SETUP FOR LES. EXPECT A PERIOD OF SOME HEAVIER LK ENHANCED SN IN THE
FAVORED SN BELTS WHEN AREA OF DPVA/DEEP LYR QVECTOR CNVGC/UVV/DEEP
MSTR ASSOCIATED WITH THE PASSING DISTURBANCE COINCIDES WITH FVRBL
UPSLOPE...WEAKLY CYC N FLOW. AREAS OVER ONTONAGON/GOGEBIC IN THE
EVNG AND MARQUETTE/ALGER COUNTIES IN THE LATER EVNG/EARLY OVERNGT
APPEAR TO BE MOST FAVORED TO SEE HEAVIER SN. ENHANCEMENT FACTOR FOR
HEAVIER SN TOTALS INCLUDE FAIRLY DEEP DGZ UP TO 4K FT. ALTHOUGH THE
SHARPEST UVV IS FCST TO BE JUST BLO THE DGZ MUCH OF THE TIME...THERE
WL BE SOME UVV IN THIS ZONE THAT SHOULD ALLOW SN/WATER RATIOS UP TO
20-25:1. ONE NEGATIVE APPEARS TO BE THE ABSENCE OF SHARP CYC FLOW/
PERSISTENT LLVL CNVGC. ALTHOUGH THE LK ENHANCEMENT WL NOT BE A
PLAYER WELL INLAND FM LK SUP...DYNAMIC FORCING SHOULD ALLOW FOR SOME
LIGHT SN EVEN OVER THE SCENTRAL. BUT ABSENCE OF HIER ABSOLUTE MSTR..
.WITH PWAT NO MORE THAN ABOUT 0.3 INCH AND H7 SPECIFIC HUMIDITY
ABOUT 1G/KG...WL LIMIT SN TOTALS TO NO MORE THAN AN INCH OR SO AWAY
FM LK ENHANCEMENT/UPSLOPE WINDS. LATER AT NGT...EXPECT THE SN TO
DIMINISH NW-SE WITH THE ARRIVAL OF DNVA/DEEP LYR QVECTOR DVGC/
SUBSIDENCE/MID LVL DRYING IN THE WAKE OF THE PASSING SHRTWV THAT IS
FCST TO STRENGTHEN INVRN AS LO AS H875-9 AS SHOWN ON NAM FCST SDNGS.
ALTHOUGH IT IS NOT COMMON PRACTICE TO ISSUE AN ADVY FOR PRIMARLIY A
3RD PERIOD EVENT...SENSITIVE TRAVEL TIME JUST BEFORE THANKSGIVING
HOLIDAY AS WELL AS FAVORABLE UPSLOPE FLOW/FAIRLY EFFICIENT SN GROWTH
PARAMETERS WARRANTS EARLY ISSUANCE OF AN LES ADVY IN THE FAVORED
AREAS OVER THE W/NCENTRAL DESPITE THE RATHER FLUFFY NATURE OF THE SN
THAT IS EXPECTED TO FALL. THE LES ADVY WL INCLUDE GOGEBIC/
ONTONAGON/MARQUETTE AND ALGER COUNTIES. AS MUCH AS 7 TO 8 INCHES OF
SN WL FALL IN THESE AREAS THRU THE ADVY PERIOD. N WINDS GUSTING UP
TO 25-30 MPH WL CAUSE SOME BLSN NEAR LK SUP WED NIGHT INTO THU MRNG.
THANKSGIVING/THU NGT...THE LLVL FLOW IS PROGGED TO BACK STEADILY AND
TURN MORE ACYC ON THANKSGIVING WITH SFC HI PRES MOVING TOWARD SW WI
LATE IN THE DAY UNDER HGT RISES/DNVA IN ADVANCE OF APRCHG SHRTWV
RDG. THE RESULT WL BE SHIFTING/DIMINISHING LES BANDS...ESPECIALLY
OVER THE W HALF. THE SN SHOWERS SHOULD END COMPLETELY AT IWD LATE IN
THE AFTN. THE LES WL BE MORE PERSISTENT IN THE FAVORED SN BELTS E OF
MARQUETTE WITH H85 THERMAL TROF/TEMPS ARND -18C REACHING THAT AREA
LATE IN THE DAY...BUT INCRSG ACYC FLOW AND ABSENCE OF SGNFT LLVL
CNVGC/LOWERING INVRN BASE TO H875-9 SHOWN ON THE FCST SDNGS UNDER
THE NEGATIVE DYNAMICS WL LIMIT SN TOTALS. THANKSGIVING WL BE QUITE
CHILLY WITH H85 THERMAL TROF PASSING OVHD AND COULD FEATURE SOME
RECORD LO MAX TEMPS. EXPECT THE LOWEST TEMPS OVER THE W HALF WHERE
BACKING FLOW WL LIMIT LK SUP MODERATION. AS THE SFC RDG AXIS SHIFTS
TO THE E AND THE FLOW BACKS TO THE W-SW...LINGERING LES WL SHIFT OUT
INTO LK SUP ON THU NGT. TEMPS COULD FALL QUICKLY IN THE EVNG TOWARD
THE LO END OF GUIDANCE BEFORE MORE HI CLDS OVERSPREAD THE AREA W-E
ASSOCIATED WITH DVLPG ISENTROPIC ASCENT IN THE SW FLOW ON THE NW
FLANK OF PRES SHIFTING INTO THE OH RIVER VALLEY AND IN ADVANCE OF
SHRTWV STREAKING EWD TOWARD MN. SOME OF THE FASTER MODELS SHOW SN
ASSOCIATED WITH THIS WAA/SHRTWV REACHING THE FAR W BY 12Z FRI...SO
WL MAINTAIN SOME LO CHC POPS IN THIS AREA LATE THU NGT.
FRI/FRI NGT...AS THE UPR TROF IN ERN NAMERICA SHIFTS TO THE E...THE
FLOW OVER THE CONUS/SRN CANADA WL BECOME MORE ZONAL. DVLPG LLVL SW
FLOW/ISENTROPIC ASCENT OVER THE GREAT LKS ON THE NW FLANK OF SFC HI
PRES SHIFTING INTO THE SRN MID ATLANTIC STATES AND IN ADVANCE OF
SHRTWV TRACKING EWD THRU MN IS PROGGED BY MOST OF THE MEDIUM RANGE
GUIDANCE TO BRING ABOUT SOME INCRSG MID LVL MSTR/PCPN ON FRI TO THE
NE OF AN H85 WARM FNT STRETCHING FM THE NRN PLAINS INTO MN AND WI.
ALTHOUGH INITIAL SHOT OF SHARPER ISENTROPIC ASCENT BEST SHOWN ON THE
280-290K SFCS/H85-7 FGEN AXIS/DEEP LYR QVECTOR CNVGC IS FCST TO
IMPACT NRN WI ON FRI MRNG...THIS WAA/FORCING MAY SHIFT FARTHER N
INTO UPR MI DURING THE DAY. H7 SPECIFIC HUMIDITY IS FCST AS HI AS 3
G/KG...SO NOT OUT OF THE QUESTION THERE COULD BE SOME MODERATE SN
AMOUNTS APRCHG ADVY CRITERIA OVER THE SRN CWA. AS THE H925 WINDS
BECOME MORE S IN THE PRESENCE OF H85 TEMPS IN THE -8 TO -10C
RANGE...LES OFF LK MI WL IMPACT THE ERN CWA. WL MAINTAIN THE HIER
POPS/QPF IN THIS AREA. ON FRI NGT...MORE NOTABLE MODEL DIFFERENCES
ARE SHOWING UP WITH THE 12Z GFS SHOWING A MORE WNW VS W FLOW ALOFT
AND A STRONGER SHRTWV/SFC LO TRACKING FASTER E ACROSS LK SUP ON FRI
NGT...WITH CYC NW FLOW OF COLDER AIR DVLPG OVER THE CWA LATE FRI
NGT. THIS SOLUTION IS VERY MUCH AN OUTLIER EVEN AMONG THE MOST
RECENT GFS ENSEMBLE GUIDANCE... SO TENDED TO FOLLOW THE MORE
CONSISTENT 12Z CNDN/00Z AND 12Z ECMWF MODELS. THIS GUIDANCE SHOWS A
SLOWER SFC LO AND MORE AGGRESSIVE PUSH TO THE NE OF H85 WARM
FNT...WITH H85 TEMPS RISING ABOVE 0C OVER THE SCENTRAL CWA BY 12Z
SAT ACCOMPANYING DRY SLOTTING/LOWERING POPS OVER THE SRN TIER. WITH
ECWMF SDNGS SHOWING LINGERING LLVL MSTR BLO THE WARMING/DRYING WARM
NOSE ARND H85...ADDED A MENTION OF SOME FREEZING DZ OVER THE SW CWA.
SAT/SAT NGT...SHRTWV EMBEDDED IN ZONAL FLOW OVER SRN CANADA WL
STREAM E...WITH ACCOMPANYING SFC LO STREAKING ENEWD THRU ONTARIO AND
THEN DRAGGING A COLD FNT ACRS THE CWA SAT NGT. AHEAD OF THIS FNT...
MORE CONSISTENT...FAVORED 12Z ECMWF/CNDN MODELS SHOW WARM SURGE INTO
THE UPR LKS WITH H85 TEMPS RISING AS HI AS 8-10C OVER THE SRN TIER
ON SAT UNDER SOME MID LVL DRYING. TENDED TO CUT POPS OVER THE SRN
TIER...WHERE THE ECMWF AND CNDN MODELS SHOW MORE AGGRESSIVE MID LVL
DRYING FARTHER FM THE LO TRACK. CONTINUED TO MENTION SOME RA OR
FREEZING DZ IN THESE AREAS AS WELL. FARTHER TO THE N CLOSER TO THE
LO TRACK AND SOMEWHAT HIER CHC POPS...INCLUDED MENTION OF FREEZING
RA AND RA IN ADDITION TO SN IN CASE THE AIRMASS IS A BIT COLDER. IF
SFC TEMPS END UP HIER THAN CURRENTLY FCST...LATER SHIFTS MAY BE ABLE
TO CUT BACK ON THE FREEZING DZ/RA AND GO WITH PLAIN RA. RIGHT NOW...
LOOKS LIKE ANY ICE ACCUMULATION WL BE MINOR.
EXTENDED...MUCH COLDER AIR...WITH H85 TEMPS FCST AS LO AS -18C BY
00Z MON...AND SOME LK EFFECT SN WL FOLLOW ON SUN UNDER NW FLOW BTWN
DEPARTING COLD FNT AND CNDN HI PRES BLDG E THRU THE NRN PLAINS. BUT
SINCE THE UPR FLOW WL REMAIN FAIRLY PROGRESSIVE...THE SFC HI PRES WL
SHIFT THRU THE GREAT LKS ON MON AND INTO NEW ENGLAND TUE AS UPR RDG
BLDS INTO THE UPR LKS ON TUE. THE RESULT SHOULD BE DIMINISHING LES
ON MON WITH DRY WX LINGERING INTO TUE. WARMER SW FLOW ON THE WRN
FLANK OF DEPARTING SFC HI PRES MAY DRAW ENUF MSTR TO THE N ON TUE TO
BRING A RETURN OF SOME SN OR A RA/SN MIX.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1256 AM EST WED NOV 26 2014
VFR CONDITIONS WILL CONTINUE AT KIWD/KSAW TONIGHT AND WILL CONTINUE
AT KSAW THROUGH WED. NEXT APPROACHING DISTURBANCE WILL BRING SOME
-SN/MVFR CONDITIONS TO KIWD BY WED AFTERNOON WHICH WILL FALL TO IFR
LATE WED AFTERNOON LASTING INTO THE EVENING. AT KCMX...WINDS MAY
RETAIN ENOUGH OVERWATER COMPONENT TO MAINTAIN MVFR CONDITIONS THRU
MOST OF THE PERIOD. KSAW WILL FALL TO IFR CONDITIONS BY WED EVENING
AS SNOW MOVES IN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 PM EST TUE NOV 25 2014
PRES GRADIENT RAPIDLY WEAKENS TONIGHT WITH A WEAK SFC TROF DROPPING
SE OVER LAKE SUPERIOR. THIS WILL RESULT IN WINDS DIMINISHING TO UNDER
20KT ACROSS THE LAKE. STRONG HIGH PRES WILL THEN BUILD SE INTO THE
CANADIAN PRAIRIES WED AND INTO THE NRN PLAINS WED NIGHT. THIS WILL
PUSH THE TROF SE AND TIGHTEN THE PRES GRADIENT. AS A RESULT... WITH
THE TROF PASSAGE...EXPECT NORTHERLY WINDS TO RAMP UP TO 20-30KT FROM
NW TO SE WED/WED NIGHT. NOT OUT OF THE QUESTION THAT THERE COULD BE
SOME GALE FORCE GUSTS OVER THE CNTRL PORTION OF LAKE SUPERIOR. WINDS
WILL THEN DIMINISH TO UNDER 20KT W TO E THU/THU NIGHT AS HIGH PRES
RIDGE ARRIVES. WITH ANOTHER COLD FRONT PUSHING ACROSS THE UPPER LAKES
SAT...EXPECT INCREASING WINDS TO 15-25KT FRI/FRI NIGHT AHEAD OF
FRONT. BEHIND FRONT...NW WINDS MAY REACH 20-30KT LATE SAT/SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
THURSDAY FOR MIZ006.
LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
THURSDAY FOR MIZ005.
LAKE EFFECT SNOW ADVISORY FROM 3 PM EST /2 PM CST/ THIS
AFTERNOON TO 10 AM EST /9 AM CST/ THURSDAY FOR MIZ002-009.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KC
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
1148 PM CST TUE NOV 25 2014
.UPDATE...
ISSUED AT 926 PM CST TUE NOV 25 2014
EXPANDED THE WINTER WEATHER ADVISORY NORTH A COUPLE ROWS OF
COUNTIES TO INCLUDE AREAS FROM WILLMAR TO ST PAUL AND SOUTH. THE
NAM AND GFS CONTINUE TO ADVERTISE THE NORTHERN BATCH OF SNOW OVER
NORTH DAKOTA WEAKENING OVERNIGHT AS IT HEADS SOUTHEAST...WITH THE
SOUTH DAKOTA BATCH PUSHING INTO SOUTHWEST MINNESOTA OVERNIGHT. AN
INVERTED TROUGH IS EXPECTED TO DEVELOP WEDNESDAY...WITH THE
NORTHERN BATCH ENERGIZING AFTER SUNRISE ACROSS MOST OF EAST
CENTRAL MINNESOTA. THE 21Z SREF HAS SHIFTED NORTH TO COME INTO
LINE WITH THE NAM AND GFS...AND THE HI-RES MODELS OF
HOPWRF...HRRR...AND TO SOME DEGREE THE RAP IN BRINGING THE
BULLS EYE OF HEAVIEST SNOW FROM JUST NORTH OF MANKATO INTO THE FAR
SOUTHWESTERN TWIN CITIES SUBURBS. THIS IS THE AREA WHERE THIS
ENERGIZED BATCH OF SNOW IS EXPECTED TO LINGER FOR SOME TIME DURING
THE LATE MORNING AND EARLY AFTERNOON LEADING TO AT LEAST A FEW TO
AS MUCH AS 5 INCHES. SNOW WILL QUICKLY DISSIPATE DURING MID
AFTERNOON...WITH A SHARP CUT OFF TO SNOW AMOUNTS TO THE EAST OVER
FAR WESTERN WI.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 415 PM CST TUE NOV 25 2014
THE MAIN CONCERN IN THE SHORT TERM IS A CLIPPER SYSTEM MOVING
SOUTHEAST FROM THE DAKOTAS TO IOWA TONIGHT AND WEDNESDAY. THERE
REMAINS QUITE A BIT OF SPREAD IN THE QPF FROM THE VARIOUS
DETERMINISTIC SOLUTIONS TODAY ON HOW FAR EAST SIGNIFICANT
ACCUMULATING SNOW (3+") WILL GO ON WEDNESDAY. ALTHOUGH THE H7 LOW
ASSOCIATED WITH THE CLIPPER WILL BASICALLY PASS ACROSS SOUTHWEST
MN LATE TONIGHT...A SECOND SHORT WAVE IS PUSHING ACROSS FAR
NORTHERN MN DURING THIS SAME TIME. THE NAM AND THE GFS HAVE MUCH MORE
QPF SPREADING NORTHEAST AHEAD OF THE NORTHERN STREAM
FEATURE...WHICH IF TRUE...WOULD RESULT IN MUCH MORE SNOW ACROSS
EASTERN MN AND WEST CENTRAL WI THEN CURRENTLY FORECAST...WHICH IS
IN THE 1 TO 2 INCH RANGE. THE GEM AND ECMWF HAVE MORE SEPARATION
IN THE QPF...WITH MUCH OF THE SNOW FOCUSED FROM WEST CENTRAL
THROUGH SOUTH CENTRAL MINNESOTA LATE TONIGHT AND WEDNESDAY. ITS
INTERESTING TO NOTE THAT THE PAST FIVE RUNS OF THE ECMWF HAVE
SHOWN THE MID LEVEL LOW SINKING SLOWLY SOUTHWARD WITH TIME WHICH WOULD
KEEP THE HEAVIEST SNOW TO THE WEST AND SOUTH OF THE TWIN CITIES.
THE 15Z SREF IS BASICALLY IN LINE WITH THIS IDEA...SHOWING THE
HIGHEST PROBABILITIES (60-80 PERCENT) FOR GREATER THAN 0.25 INCHES
OF QPF IN 12 HOURS FROM WEST CENTRAL THROUGH SOUTH CENTRAL
MINNESOTA. THERE IS A LITTLE BIT OF A FINGER OF HIGHER
PROBABILITIES POINTING TOWARDS THE SOUTHWEST TWIN CITIES METRO.
HENCE...WITH CONFIDENCE HIGHEST FOR 3+ INCHES OF SNOW LATE TONIGHT
AND WEDNESDAY MORNING FROM WEST CENTRAL THROUGH SOUTH CENTRAL
MINNESOTA...A WINTER WEATHER ADVISORY WAS ISSUED FOR THESE AREAS.
WITH SOME HINT THAT THE HEAVIER SNOW COULD GET A LITTLE MORE TO
THE EAST...THE ADVISORY REACHES ACROSS MCLEOD AND SIBLEY COUNTIES.
KEPT THE ADVISORY GOING ALONG THE I-35 CORRIDOR FROM NORTHFIELD TO
ALBERT LEA DURING THE AFTERNOON WHERE SNOW WILL LINGER.
LOW TEMPERATURES TONIGHT ARE A LITTLE TRICKY WITH THE LOW CLOUDS
TRYING TO DIMINISH SOME THIS EVENING WHILE SOUTHERLY LOW LEVEL
FLOW/WAA INCREASES. WENT ON THE LOW SIDE OF GUIDANCE WITH
DEW POINTS ONLY IN THE SINGLE DIGITS AND TEENS ALONG WITH SOME SNOW
COVER. HIGHS ON WEDNESDAY ONLY IN THE TEENS ACROSS THE WEST WITH
LOWER TO MIDDLE 20S EAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 415 PM CST TUE NOV 25 2014
THE LONG TERM CONTINUES THE PUSH PULL WEATHER PATTERN WITH BRIEF
WARM UP/COOL DOWNS. THE INITIAL WAVE EXITS EARLY WEDNESDAY
NIGHT...WITH COOLER HIGH PRESSURE FOLLOWING FOR THANKSGIVING DAY.
HIGH TEMPERATURES EXPECTED TO REMAIN IN THE TEENS ONCE AGAIN.
THE NEXT WAVE MOVES IN WITH WAA DRIVING EAST ACROSS THE AREA
THANKSGIVING NIGHT AND FRIDAY. A GENERAL 2-3 INCH SNOW IS LIKELY
ALONG AND NORTHEAST OF I-94. THE WARM FRONT LIFTS NORTH ACROSS THE
CWA. DEPENDING ON SUNSHINE...TEMPERATURES COULD WARM THROUGH THE
30S AGAIN...ESPECIALLY IN THE FAR SOUTH. HOWEVER...THERE IS SOME
MODEL TIMING ISSUES...WITH THE GFS FASTER WITH THE NEXT COLD FRONT.
WILL MOVE TOWARDS A SLOWER AND WARMER SOLUTION FOR NOW...WITH SOME
SMALL CHANCE POPS ASSOCIATED WITH THIS FRONT. BETTER FORCING AND
BAROCLINIC ZONE DEVELOPS ALONG THE NORTHERN PERIPHERY OF THE AREA.
THE PRECIPITATION...IF IT DOES DEVELOP..COULD BE IN THE FORM OF
FREEZING DRIZZLE/LIGHT SNOW OR FLURRIES. THE GFS IS THE MORE ROBUST MODEL
IN THE OVERALL DEVELOPMENT ACROSS THE REGION.
ARCTIC HIGH PRESSURE DROPS SOUTH AGAIN OVER THE CWA FOR SATURDAY AND
SATURDAY NIGHT. WE SHOULD SEE CLOUDS CLEAR OUT OF THE AREA DURING
THE DAY SUNDAY...PROVIDING DRIVE HOLIDAY TRAVEL FOR THE AREA. COLD
TEMPERATURES RETURN WITH HIGHS IN THE TEENS BOTH SUNDAY AND
MONDAY...BEFORE THE NEXT UPPER TROUGH SWINGS OVER THE WESTERN CONUS
AND DRIVES WARMER AIR BACK NORTH AND EAST TOWARD THE NORTHERN
PLAINS/WESTERN GREAT LAKES FOR TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1139 PM CST TUE NOV 25 2014
CONFIDENCE HAS INCREASED FROM THE LAST SET OF TAFS REGARDING THE
SNOW FOR WEDNESDAY. IT HAS ALREADY BEGUN PUSHING INTO THE RWF AREA
AND WILL TAKE ANOTHER HOUR OR TWO TO REACH AXN. EASTWARD
PROGRESSION WILL SLOW OVERNIGHT...THEN BEGIN TO DEVELOP FURTHER
EAST INTO THE TWIN CITIES METRO AND STC SHORTLY BEFORE DAWN.
INVERTED TROUGH SHOULD CONCENTRATE MUCH OF THE SNOW DURING THE
DAYTIME IN AN AREA FROM STC TO RWF...MKT...AND MSP. SNOW RATES
WILL INCREASE BETWEEN 12-18Z IN THIS AREA WHERE 1/2 TO 1 INCH PER
HOUR RATES ARE POSSIBLE FOR A TIME. THE SNOW WILL TAPER OFF DURING
THE AFTERNOON FROM WEST TO EAST. ONLY LOOKING FOR A 2 TO 4 HOUR
WINDOW OF LIGHT SNOW ACROSS WRN WI...MAINLY DURING THE MID
AFTERNOON TO EARLY EVENING.
KMSP...LIGHT SNOW LOOKS LIKE IT WILL BEGIN AROUND 12Z...AND COULD
BECOME MORE INTENSE BETWEEN 14-19Z WHEN SNOWFALL RATES OF 1/2 TO 1
INCH PER HOUR AND IFR/LIFR CONDITIONS ARE POSSIBLE. THE SNOW WILL
TAPER OFF MID AFTERNOON WITH VFR CONDITIONS EXPECTED AFTER MID
EVENING.
/OUTLOOK FOR KMSP/
THU...VFR. NW 4-8 KTS.
FRI...CHC MVFR AND -SN. WINDS SE 5 KTS.
SAT...CHC MVFR. WINDS NORTH 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST WEDNESDAY FOR
MNZ059-060-062-068>070-076-077-084-085-093.
WINTER WEATHER ADVISORY UNTIL NOON CST WEDNESDAY FOR MNZ054-
056>058-064>067-073>075-082-083-091-092.
WI...NONE.
&&
$$
UPDATE...BORGHOFF
SHORT TERM...RAH
LONG TERM...DWE
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1236 AM EST WED NOV 26 2014
.SYNOPSIS...
A STORM SYSTEM MOVING ALONG THE EAST COAST WEDNESDAY INTO THURSDAY
MORNING WILL IMPACT ALL OF NORTHEAST PENNSYLVANIA AND A LARGE PART
OF CENTRAL NEW YORK WITH A SIGNIFICANT SNOWFALL. THE HEAVIEST SNOW
IS EXPECTED FROM THE POCONOS TO THE WESTERN CATSKILLS. SNOW WILL
DEVELOP LATE TONIGHT AND LAST THROUGH WEDNESDAY AND TAPER OFF TO
SNOW SHOWERS WEDNESDAY NIGHT AND EARLY THURSDAY. SNOWFALL OF 5 TO
12 INCHES IS EXPECTED FROM NORTHEAST PENNSYLVANIA TO THE CATSKILLS
WITH 2 TO 6 INCHES TO THE NORTH AND WEST. LESS THAN 2 INCHES OF SNOW
IS EXPECTED ACROSS THE NORTHERN FINGER LAKES REGION TO THE
SYRACUSE AREA.
&&
.NEAR TERM /THROUGH TODAY/...
8 PM UPDATE...
L/WV TROF IS MVG THRU MS VLY AT THIS TIME WITH STRONG S/WV
ROUNDING BASE OF TROF OVR LWR MS RVR. CYCLOGENESIS UNDERWAY ACRS
NE GOM WITH PCPN NOW BEING REPORTED AS FAR NORTH AS THE PIEDMONT
OF NC. LATEST MODELS HV TRENDED JUST A TAD SLOWER WITH PCPN
EXPECTED TO MV INTO CWA CLOSER TO 12Z. RUC AND HIRES ARW SEEM TO
HV BEST HANDLE ON PCPN AS OF 00Z AND NOT SHOWING MUCH IN THE WAY
OF ECHOES MVG INTO POCONOS UNTIL 11Z AT THE EARLIEST.
AS PCPN HEADS NORTH EXPECTING TO SEE JUST A WALL OF SNOW HEADING
AT US. THUS HV GONE FM LOCHC POPS TO CATEGORICAL DRG THE MRNG HRS.
18Z NAM HAS TRENDED A TAD WETTER AND FURTHER WEST WITH PCPN WITH
24-HR AMNTS OVR 1+ INCHES OVR FAR SE ZONES AND 0.75 INCHES AS FAR
WEST AS AN ELMIRA-UTICA LINE. WL EVALUATE 00Z GUIDANCE COMING IN
AND POSSIBLY EXPAND WARNINGS/ADVISORIES FURTHER WEST OVRNGT.
FOR NOW, HV LWRD SNOW AMNTS BTWN 06Z AND 12Z OVR NEPA AND ADJUSTED
AMNTS HIGHER FOR THE 12Z-18Z TIMEFRAME AS THIS LOOKS TO BE
PRIMETIME. CONCERN IS THAT MESOSCALE BANDING WL SET UP JUST A HAIR
FURTHER WEST LATE MRNG OR EARLY AFTN THAN MODELS ARE INDICATING.
TREMENDOUS VERTICAL MOTION EXPECTED LATE MRNG INTO THE AFTN HRS IN
AREA OF ENHANCE UPWARD DIFFLUENCE AS CWA WL LKLY BE IN RRQ OF H2
JET. NO OTHER ADJUSTMENTS NEEDED AT THIS TIME.
PREV DISCUSSION BLO...
ISSUED WINTER STORM WARNINGS FOR MOST OF NORTHEAST PENNSYLVANIA
AND THE WESTERN CATSKILLS IN LINE WITH NEIGHBORING OFFICES AND
BASED ON THE LATEST MODEL GUIDANCE WWD AND MODEL QPFS. MODELS ALL
INDICATE THAT CYCLOGENESIS BEGINS ALONG THE EAST COAST WEDNESDAY
INTO WEDNESDAY NIGHT AS A STRONG UPPER LEVEL WAVE ROUNDS THE BASE
OF THE UPPER LEVEL TROUGH OVER THE EASTERN UNITED STATES. THE
STORM WILL NOT CLOSE OFF AT 700 MB UNTIL IT IS NORTHEAST OF THE
REGION AS THE SYSTEM GETS CAUGHT UP IN THE STRG SWRLY FLOW ALOFT.
THIS WILL LEAD TO LESS LINGERING WRAP ARND ACCUMULATIONS THAT WE
OFTEN SEE IN C NY/NRN PA. BASICALLY THIS SYSTEM WILL RUN INTO UPPER
CONFLUENCE OVER THE MARITIMES BY THURSDAY AND SHEAR OUT. BUT IN THE
PROCESS SIGNIFICANT WARM CONVEYOR BELT MOISTURE IS RUNNING INTO
THE UPPER DIFFLUENCE OF THE RIGHT ENTRANCE REGION OF THE UPPER JET
OVER SERN CANADA. THIS IS FAVORABLE FOR A SWATH OF HEAVY SNOW.
MODELS ARE SHOWING THAT THE HEAVIEST SNOW IN OUR FORECAST AREA IS
FROM NE PA TO DELAWARE/SULLIVAN CO/S IN NY.
CROSS SECTIONS NORMAL TO THE THICKNESS ACROSS NE AND C NY SHOW A
CLASSIC SLOPED LAYER OF FGEN FORCING WED PM WITH LOW STATIC
STABILITY ABOVE OR EVEN WEAKLY UNSTABLE ALOFT. THIS IS A RECIPE
FOR MESOSCALE SNOW BANDS AND BELIEVE A BAND OF HEAVY SNOW WILL
FORM SOMEWHERE IN OUR WARNING AREA. IN GRIDS HAVE MENTION OF
HEAVY SNOW IN THIS AREA. I ALSO AM CONCERNED THAT THIS BAND COULD
TRACK FARTHER WEST AS IS OFTEN THE CASE AND IMPACT OUR ADVY AREA. THE
12Z EURO NOW HAS MORE QPF FARTHER WEST TOO. FOR NOW HAVE A ROW OF
WINTER WX ADVY/S AS A BUFFER ZONE FROM TOWANDA TO BINGHAMTON TO
COOPERSTOWN AND NORWICH. THIS AREA COULD GET INTO SOME HEAVY SNOW.
IT DEPENDS ON WHERE THIS MESOSCALE BAND SETS UP. LATER SHIFTS WILL
HAVE TO MONITOR. OUR BRIEFINGS WILL MENTION THE CHANCE THAT SOME
HEAVIER SNOW COULD FALL FARTHER WEST.
FOR THE REST OF WEDNESDAY NIGHT...SNOW WILL RAPIDLY TAPER DOWN TO
SNOW SHOWERS FROM SW TO NE AS THE STORM PULLS TO THE NORTHEAST.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
300 PM EST UPDATE...
CAA WILL CONTINUE TO TAKE PLACE ACROSS THE CWA THURS AS THE SFC
LOW MOVES FURTHER NORTH ALONG THE EAST COAST. THIS WILL ALLOW COOLER
AIR TO MOVE INTO PORTIONS OF NY AND PA. THIS WILL RESULT IN THURS
BEING FAIRLY COLD WITH TEMPERATURES ONLY RISING INTO THE LOW TO
MID 30S. EVEN THOUGH THE POTENT STORM THAT HAVE CAUSED WARNINGS
ACROSS THE EAST WILL BE WELL TO THE NORTH BY THURS... THIS DOES
NOT MEAN AN END TO SNOW SHOWERS OVER THE CWA. THE CHANCE FOR SNOW
ACROSS OUR AREA WILL STILL CONTINUE. SCATTERED SNOW SHOWERS WILL
STILL BE POSSIBLE THROUGH THE DAY ON THURSDAY. THESE SNOW SHOWERS
WILL BE THE RESULT FROM AN ALBERTA CLIPPER PASSING THROUGH.
THESE SHOWERS ARE EXPECTED TO TO BE LIGHT AND SCATTERED IN NATURE.
SOME LAKE EFFECT ACTIVITY WILL BE POSSIBLE BEHIND THE PASSAGE OF
THE CLIPPER. THE BEST CHANCE FOR LE SNOW SHOWERS WILL BE SHORTLY
AFTER 00Z FRIDAY THROUGH 00Z SATURDAY. TEMPS WILL BE A FEW DEGREES
COOLER ON FRIDAY ACROSS MUCH OF THE AREA AS A VERY COLD AIRMASS
WILL REMAIN OVER NY AND PA. SHOWERS ARE EXPECTED TO SLOWLY
DIMINISH FRIDAY NIGHT.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
300 PM EST UPDATE...
HAVE MADE MINOR ADJUSTMENTS TO THE PREVIOUS FORECAST AND CLOSELY
FOLLOWED WPC GUIDANCE.
THE FLOW ALOFT WILL REMAIN ZONAL ACROSS MUCH OF THE EASTERN CONUS
THROUGH THE FORECAST PERIOD. BUT SADLY THIS DOES NOT MEAN THE WX
PATTERN WILL REMAIN QUIET THROUGH THE EXTENDED. THERE APPEARS TO
BE A CHANCE FOR EITHER SNOW OR RAIN THROUGH THE EXTENDED.
A WEAK LOW PRESSURE SYSTEM WILL FORCE A WARM FRONT ACROSS THE
REGION EARLY SAT THEN SLOWLY BRING A COLD FRONT ACROSS THE CWA ON
SUNDAY. GUIDANCE IS UPON FAIRLY GOOD AGREEMENT ON KEEPING THE SFC
LOW WELL TO THE NORTH OF THE CWA. GUIDANCE HINTS AT HIGH PRESSURE
BUILDING STARTING TO BUILD OVER REGION ON MONDAY. THIS MAY
BRIEFLY HALT THE CHANCE FOR SHOWERS OVER THE REGION EARLY NEXT WEEK.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
A LARGE WINTER STORM WILL PRODUCE WIDESPREAD IFR VSBYS AT ALL
TERMINALS WEDNESDAY.
TIMING OF SNOW LOOKS TO BE BETWEEN 12Z AND 15Z SOUTHERN TERMINALS,
AND AFTER 15Z UP NORTH. AIRPORT MINS WILL BE APPROACHED AT
KBGM/KAVP A FEW HOURS AFTER THE ONSET OF THE SNOW, THROUGH THE END
OF THE TAF PERIOD. FARTHER NORTH AND WEST FROM KELM TO KITH, KSYR,
AND KRME IFR VSBYS LIKELY BUT NOT AS LOW AS FARTHER SOUTH.
VSBYS WILL TEND TO RISE AFTER 00Z AS THE SYSTEM BEGINS TO LIFT OUT
OF THE AREA. XPCT CIGS AND VSBY GNRLY IN THE MVFR RANGE THRU THE
END OF THEPD...AS WINDS BECOME MORE NWLY BHD THE STORM.
OUTLOOK...
WED NGT...COASTAL SYSTEM MAY IMPACT REGION WITH RESTRICTIONS FROM
SNOW...BEST CHANCE KAVP.
THU/FRI/SAT...POSSIBLE RESTRICTIONS FROM SCT -SHSN...ESPECIALLY
KSYR-KRME.
SUN...RESTRICTIONS POSSIBLE FROM -SHRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR PAZ039-040-
043-044-047-048-072.
WINTER WEATHER ADVISORY UNTIL 6 AM EST THURSDAY FOR PAZ038.
NY...WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR NYZ057-062.
WINTER WEATHER ADVISORY UNTIL 6 AM EST THURSDAY FOR NYZ045-046-
055-056.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN/PVF
SHORT TERM...KAH
LONG TERM...KAH
AVIATION...DGM/HEDEN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1224 AM EST WED NOV 26 2014
.SYNOPSIS...
RAIN WILL CONTINUE OVERNIGHT INTO WEDNESDAY MORNING AS LOW PRESSURE
MOVES UP THE SOUTHEAST COAST. SKIES WILL CLEAR OUT BY THANKSGIVING
DAY...WITH TEMPERATURES RUNNING SEVERAL DEGREES BELOW NORMAL INTO
THE WEEKEND BEFORE WARMER TEMPERATURES RETURN FOR EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 12:30 AM WEDNESDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
SO FAR SO GOOD WITH THE EARLIER CHANGES TO QPF AMOUNTS. WITH THE
EXCEPTION OF A NARROW BAND OVER WILMINGTON WHICH IS DROPPING
FAIRLY HEAVY RAIN NOW...RATES ARE 0.05 INCHES PER HOUR OR LESS
ACROSS THE BULK OF THE FORECAST AREA. RADAR COMPOSITES SOUTH TO
THE FLORIDA GEORGIA LINE SHOW A SIZABLE GAP IN RAINFALL... PERHAPS
KEEPING THOSE RED CLAY ROADS A LITTLE LESS MUDDY THAN THEY
OTHERWISE MIGHT BE. DEEP CONVECTION CONTINUES ACROSS CENTRAL
FLORIDA AND OFF THE FLORIDA EAST COAST AND THIS SHOULD CONTINUE TO
NEGATIVELY IMPACT OUR PRECIPITATION INTENSITY FOR THE NEXT 3-5
HOURS.
LATEST HRRR MODEL RUNS SHOW THE SYNOPTIC LOW MAY ACTUALLY MOVE
INLAND BRIEFLY ACROSS SE NORTH CAROLINA AROUND 11-12Z WED. A TRACK
THIS FAR WEST WOULD KEEP LOW TEMPERATURES IN WILMINGTON IN THE 60S
DUE TO ONSHORE EASTERLY FLOW. I HAVE TWEAKED THE IMPLIED SYNOPTIC
LOW TRACK A LITTLE CLOSER TO THE COAST...JUST NICKING BALD HEAD
ISLAND BEFORE DAYBREAK. PREVIOUS DISCUSSION FROM 700 PM FOLLOWS...
WE ARE ENTERING THE PERIOD OF WHAT SHOULD BE THE STRONGEST UPPER
LEVEL DIVERGENCE AND LOW-TO-MID LEVEL ISENTROPIC LIFT NOW. 305K-310K
ISENTROPIC LIFT FORECASTS FROM THE 18Z NAM OR GFS SUGGEST IT SHOULD
BE POURING EVERYWHERE! HOWEVER THE BROAD-SCALE RADAR COMPOSITE SHOWS
THE FORECAST PROBLEM FOR TONIGHT: WIDESPREAD DEEP CONVECTION ACROSS
THE FLORIDA PENINSULA AND OFFSHORE EAST OF JAX IS PRODUCING
DOWNSTREAM MID-LEVEL WARMING AND DRYING THAT IS NEGATIVELY IMPACTING
PRECIPITATION COVERAGE ACROSS SOUTH GEORGIA AND THE CAROLINAS. THIS
IS A CLASSIC PROBLEM WE SEE LOCALLY DURING THE COOL SEASON THAT HAS
FRANKLY NEVER BEEN HANDLED WELL BY THE SYNOPTIC MODELS.
BOTH THE HRRR AND HRRRX (AN EXPERIMENTAL VERSION AVAILABLE ON THE
RAPID REFRESH.NOAA.GOV SERVER) ARE INITIALIZING WITH THE CORRECT
"HOLE" IN THE PRECIPITATION SHIELD AND SHOW THIS ANOMALY MAY
CONTINUE TO PLAGUE THE REGION`S RAINFALL FORECAST THROUGH THE NIGHT.
THE 18Z SYNOPTIC RAINFALL GUIDANCE FROM WPC ALSO SEEMS TO AGREE WITH
THIS IDEA OF LESSER RAINFALL TOTALS THAN ORIGINALLY THOUGHT. WITH
THIS IN MIND I HAVE KEPT FORECAST POPS AT 100% (EVERYONE WILL GET AT
LEAST 0.01 INCHES OF RAIN) BUT I HAVE TRIMMED BACK FORECAST RAINFALL
AMOUNTS SUBSTANTIALLY. FROM RIGHT NOW THROUGH THE END OF THE EVENT
LATE WEDNESDAY MORNING IT APPEARS TOTALS SHOULD AVERAGE HALF OF AN
INCH...PERHAPS APPROACHING AN INCH ALONG THE COAST IF RAINFALL RATES
CAN INCREASE TOWARD THE END OF THE EVENT WEDNESDAY MORNING.
OVER THE PAST FEW DAYS SYNOPTIC GUIDANCE HAS TRENDED FARTHER WEST
WITH THE FORECAST PATH OF THE LOW MOVING NORTH FROM FLORIDA. 18Z
MODELS CONTINUED THIS TREND AND I HAVE SHIFTED THE IMPLIED TRACK OF
THE LOW IN THE FORECAST WIND GRIDS TO ONLY ABOUT 10 MILES EAST OF
CAPE FEAR LATE TONIGHT. THIS WILL HAVE THE ADDED IMPACT OF
MAINTAINING A WARMER AIRMASS NEAR THE COAST...PARTICULARLY SE NORTH
CAROLINA...AND I HAVE RAISED FORECAST LOWS BY SEVERAL DEGREES HERE.
FARTHER INLAND THE COLD AIR SHOULD BEGIN TO BLEED IN FROM THE NW
SHORTLY AND VERY FEW CHANGES WERE NEEDED TO THE OVERALL TEMP/WIND
FORECAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...LOW PRESSURE HUGGING THE COAST WILL BE MOVING
N OF THE WATERS WEDNESDAY MORNING. AS THE LOW MOVES UP THE NORTH
CAROLINA AND MID ATLANTIC COAST WED...THE RAIN WILL SHUT OFF FROM
SSW TO NNE. PERIODS OF HEAVY RAIN ARE STILL POSSIBLE WED
MORNING...BUT EXPECT BY AFTERNOON...THE RISK FOR RAINFALL WILL HAVE
ENDED ACROSS ALL BUT THE CAPE FEAR AREA WHERE A SLIGHT RISK OF
AFTERNOON RAIN WILL STILL BE POSSIBLE. WILL INCLUDE CATEGORICAL POPS
WED MORNING THROUGHOUT. CONVECTION IS EXPECTED TO STAY OFFSHORE...
EAST OF THE LOW CENTER WHERE THERE WILL BE AN INFLUX OF WARMER AND
MORE UNSTABLE AIR.
ONE VERY POTENT MID-LEVEL SHORTWAVE TROUGH WILL PIVOT ACROSS THE
FORECAST AREA WED AFTERNOON WHILE ANOTHER SKIRTS OUR FORECAST AREA
TO THE N LATE WED NIGHT AND THU MORNING BEFORE LIFTING OUT. THE
INFLUX OF COLDER AND DRIER AIR WORKING INTO THE EASTERN CAROLINAS ON
THE BACKSIDE OF FIRST SHORTWAVE WILL HELP TO SIGNIFICANTLY DRY THE
COLUMN WITH PRECIPITABLE WATER VALUES DROPPING TO LESS THAN HALF AN
INCH. THIS WILL HELP TO PROMOTE DECREASING AFTERNOON CLOUDINESS...
ESPECIALLY ACROSS SOUTHERN AND WESTERN ZONES. THE SECOND SHORTWAVE
MAY ACTUALLY BRING A BRIEF INCREASE IN CLOUD COVER...BUT
PRECIPITATION IS EXPECTED TO REMAIN TO OUR N.
TEMPS ON WED WILL NOT MOVE MUCH AS COLD AIR ADVECTION GETS UNDERWAY.
IN FACT HIGHS WILL BE ACHIEVED IN MANY CASES PRIOR TO OR AROUND
SUNRISE. WE EXPECT HIGHS TO BE IN THE LOWER TO MID 50S ON THE COAST
WITH UPPER 40S TO AROUND 50 FROM EYF TO HYW AND POINTS W. DAYTIME
TEMPS WILL HOLD STEADY OF NOT DROP A DEGREE OR TWO. TEMPS WED NIGHT
WILL DROP INTO THE 30S TO AROUND 40. EVEN THE COLDEST SPOTS SHOULD
NOT REACH THE FREEZING MARK GIVEN THE LACK OF RADIATIONAL COOLING.
CHILLY HIGH PRESSURE WORKING TO THE COAST FROM THE W WILL ALLOW THE
PRESSURE GRADIENT TO LOOSEN THU NIGHT. THE COOLEST TEMPS AT 850 MB
THU WILL BE OFFSET BY SUNSHINE AND WE DO EXPECT HIGHS TO STILL REACH
THE MID 50S. RADIATIONAL COOLING WILL DEVELOP THU NIGHT WHICH SHOULD
ALLOW LOWS TO DROP INTO THE UPPER 20S TO LOWER 30S OVERNIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY...LONG TERM PERIOD WILL REMAIN DRY WITH MID
LEVEL FLOW BECOMING PROGRESSIVE. COLD ADVECTION WILL BE WINDING DOWN
FRI...BUT TEMPS STILL END UP WELL BELOW CLIMO. DEEP WESTERLY FLOW
WILL BE QUICK TO SHIFT THE CENTER OF THE MODIFYING HIGH OFF THE
COAST WITH RETURN FLOW DEVELOPING SAT. TEMPS REMAIN BELOW CLIMO SAT
BUT WILL BE WARMER THAN FRI. EARLY NEXT WEEK 5H RIDGE TRIES TO BUILD
NORTH FROM THE EASTERN GOMEX AND FL. BUILDING HEIGHTS AND INCREASING
SOUTHWEST FLOW EARLY NEXT WEEK WILL PUSH TEMPS ABOVE CLIMO. BACKDOOR
COLD FRONT DEPICTED IN MEDIUM RANGE GUIDANCE YESTERDAY NOW LOOKS
TIMED TO CROSS THE AREA TUE MORNING...WITH BOTH GFS/ECMWF IN DECENT
AGREEMENT. FRONT WILL PASS DRY FOLLOWED BY WEAK COLD ADVECTION WITH
TEMPS DROPPING BACK NEAR CLIMO.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 06Z...EXPECT MAINLY IFR/LIFR CIGS TO PREVAIL DURING THE EARLY
MORNING HOURS WITH RAIN CONTINUING TO FALL ACROSS THE AREA. VSBYS
WILL BE REDUCED TO MVFR LEVELS IN PATCHES OF HEAVIER PCPN. ALTHOUGH
A BRIEF LULL IN RAINFALL IS POSSIBLE BEFORE DAYBREAK...MORE SHOULD
SPREAD OVER OUR CWA THIS MORNING AS LOW PRESSURE RIDES UP THE COAST
ALONG A STALLED FRONT OFFSHORE. EAST-NORTHEAST WINDS AROUND 10 KT
WILL BECOME NORTHWEST AND GUSTY BY 12Z AS THE LOW SKIRTS OUR COAST.
THE ENHANCED GRADIENT WILL RESULT IN NORTHWEST WINDS 15-20 KT DURING
THE MORNING/EARLY AFTERNOON HOURS. IFR CIGS WILL GRADUALLY LIFT TO
MVFR THROUGH THE MORNING. AFTER 18Z...RAIN WILL DIMINISH AND DRIER
W-NW FLOW WILL PROMOTE FURTHER CLEARING ON THE BACK SIDE OF THE LOW.
ALL TAF SITES SHOULD BE VFR BY 00Z THU AS WEST WINDS DIMINISH TO 5
KT.
EXTENDED OUTLOOK...VFR CONDITIONS EXPECTED THURSDAY THROUGH SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 12:30 AM WEDNESDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
LATEST HRRR MODEL RUNS SHOW THE LOW TRACKING A BIT FARTHER WEST
THAN THE AFTERNOON MODELS INDICATED. I HAVE TWEAKED THE IMPLIED
TRACK OF THE LOW ANOTHER 5 MILES WEST IN THE LATEST GRIDDED WIND
FORECAST...JUST NICKING BALD HEAD ISLAND BEFORE DAYBREAK. THIS
WOULD BRING SOUTHERLY WINDS ACROSS MOST OF THE COASTAL WATERS
NORTH OF CAPE FEAR LATE TONIGHT. OTHERWISE FEW CHANGES WERE NEEDED
TO THE FORECAST THIS EVENING. PREVIOUS DISCUSSION FROM 700 PM
FOLLOWS...
THE CAROLINA COASTAL WATERS ARE IN A LULL CURRENTLY AS LOW PRESSURE
DEVELOPS ALONG A FRONT STALLED ACROSS THE FLORIDA PENINSULA. THIS
FRONT EXTENDS NORTHEASTWARD TO VERY NEAR CAPE FEAR WHICH EXPLAINS
THE WEAK PRESSURE GRADIENT WE SEE ON SURFACE CHARTS. AS THE NIGHT
PROGRESSES THE LOW SHOULD FOLLOW THE FRONT
NORTH-NORTHEASTWARD...GRADUALLY DEEPENING AND PASSING JUST EAST OF
CAPE FEAR BEFORE DAYBREAK WEDNESDAY MORNING. WITH THE FRONT
REMAINING JUST OFF THE COAST WE SHOULD NOT SEE VERY STRONG WINDS
ACROSS THE COASTAL WATERS TONIGHT...15 KNOTS OR LESS THROUGH EARLY
WEDNESDAY MORNING. THE EXCEPTION TO THIS MAY BE ACROSS THE WATERS
10-20 MILES EAST OF CAPE FEAR WHERE STRONG SOUTH WINDS DEVELOPING
AROUND MIDNIGHT AHEAD OF THE INTENSIFYING LOW COULD REACH 25 KNOTS.
CERTAINLY OFFSHORE BEYOND 20 MILES WINDS ARE GOING TO INTENSIFY
QUITE A BIT OVER THE NEXT 6 HOURS AHEAD OF THE LOW. THIS WILL BE
IMPORTANT SINCE SEAS WILL BUILD QUITE SUBSTANTIALLY OFFSHORE...AND A
GOOD DEAL OF SOUTHERLY SWELL ENERGY SHOULD PROPAGATE INTO THE
COASTAL WATERS BEGINNING LATE THIS EVENING. FOR THIS REASON THE
SMALL CRAFT ADVISORY WILL REMAIN IN EFFECT FOR THESE 4-6 FOOT SEAS
DEVELOPING AFTER MIDNIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...SMALL CRAFT ADVISORY CONDITIONS WILL CONTINUE
THROUGH THE DAY WED. WE DO THINK THESE CONDITIONS MAY WANE WED EVE.
HOWEVER...IT IS POSSIBLE THAT SMALL CRAFT ADVISORY CONDITIONS
REDEVELOP FOR A TIME LATE WED NIGHT AND THU AS BACKSWELL FROM
COASTAL LOW PRESSURE WELL NORTH OF THE AREA WORKS DOWN THE COAST.
ALSO...THE PRESSURE GRADIENT BETWEEN HIGH PRESSURE TO OUR W AND
COASTAL LOW WILL HELP TO INCREASE LOW-LEVEL WIND SPEEDS AS SURGE OF
COLDEST AIR ARRIVES ACROSS THE WATERS. THE WIND DIRECTION WILL BE NW
OR TRANSITIONING TO NW WED MORNING AS THE LOW MOVES FURTHER UP THE
COAST. THE DIRECTION WILL THEN BACK TO A MORE WESTERLY DIRECTION WED
NIGHT AND THU. AS HIGH PRESSURE TO THE W BEGINS TO ASSERT ITSELF
LATE THU AND THU NIGHT...THE WIND DIRECTION WILL VEER TO NW AND THEN
N. HIGHEST WIND SPEEDS THIS PERIOD WILL BE UP TO 20 TO 25 KT AND
SEAS UP TO 5 TO 8 FT.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 300 PM TUESDAY...DECREASING NORTHWEST FLOW ON FRI WILL BECOME
LIGHT AND VARIABLE FRI NIGHT INTO SAT AS SURFACE RIDGE AXIS MOVES
OVERHEAD. LIGHT SOUTHERLY FLOW DEVELOPS SAT AFTERNOON AS THE
CENTER OF THE HIGH PUSHES EAST OF THE WATERS. GRADIENT BECOMES A
LITTLE MORE DEFINED LATER SAT WITH SOUTHWEST FLOW INCREASING TO 10
TO 15 KT SAT NIGHT AND SUN. SEAS 2 TO 4 FT FRI MORNING DROP TO 2
TO 3 FT FRI NIGHT AND 2 FT OR LESS SAT AND SUN.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ250-
252-254-256.
&&
$$
SYNOPSIS...RJD
NEAR TERM...REK/RGZ
SHORT TERM...RJD
LONG TERM...III
AVIATION...BJR
MARINE...REK/RJD/III/RGZ
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
126 AM EST WED NOV 26 2014
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO EXTEND INTO THE REGION INTO
WEDNESDAY. A CLIPPER WILL PASS JUST SOUTH OF THE AREA WEDNESDAY
NIGHT. HIGH PRESSURE WILL SLOWLY BUILD IN LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
FORECAST AREA WILL BE UNDER THE INFLUENCE OF SURFACE HIGH PRESSURE
OVERNIGHT AS COASTAL STORM ORGANIZES OFF THE CAROLINA COAST.
LATEST RAP AND NAM-WRF SUGGEST THAT INCREASING DIVERGENCE ALOFT
FROM THE RIGHT REAR QUAD OF A STRONG UPR LVL JET COMBINED WITH MID
LEVEL DEFORMATION WILL SPREAD PCPN NORTHWARD ON THE BACK SIDE OF
THIS LOW ACROSS THE SRN AND CNTRL APPALACHIANS. THIS PCPN SHIELD
SHOULD REMAIN JUST EAST/SOUTHEAST OF OUR FAR SE ZONES BY MORNING.
MUCH OF THE AREA WILL BE MOSTLY CLOUDY DUE TO INCREASING MID LEVEL
CLOUDINESS. THE NRN AND NWRN ZONES WILL BE CLOUDY AS LOW LEVEL
MOISTURE REMAINS TRAPPED UNDERNEATH A SUBSIDENCE INVERSION WITH
HIGH PRESSURE OVERHEAD. ALL IN ALL...THE FORECAST WILL REMAIN
DRY...AND WITH PERSISTENT CLOUDS...TEMPERATURES WILL NOT FALL THAT
MUCH FROM CURRENT READINGS. LOWS WILL RANGE FROM THE MID 20S NW TO
THE LOWER 30S SE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
HIGH PRESSURE WILL GET PINCHED OFF BETWEEN LARGE LOW PRESSURE
SYSTEM ON THE EAST COAST AND AN APPROACHING CLIPPER. SYNOPTIC
MODELS SUGGEST THAT PRECIPITATION FROM THE FORMER COULD AFFECT
FAR SOUTHEAST COUNTIES. HOWEVER HIGH RESOLUTION RUNS KEEP IT
FURTHER AWAY FROM THE FORECAST AREA. HAVE OPTED TO CONTINUE WITH A
DRY FORECAST FOR WEDNESDAY. COULD BE A GOOD DEAL OF CLOUD COVER
THOUGH AS THERE IS SOME POTENTIAL FOR LOW CLOUDS TO REDEVELOP
ACROSS PARTS OF THE AREA AND THEN HIGH CLOUDS FROM BOTH LOW
PRESSURE SYSTEMS.
CLIPPER WILL DIVE INTO SOUTHERN ILLINOIS BY WEDNESDAY EVENING AND
THEN MAKE THE TURN EAST NEAR THE KENTUCKY-TENNESSEE BORDER. CANNOT
RULE OUT SOME LIGHT SNOW OCCURRING ALONG AND SOUTH OF THE OHIO
RIVER. BUT PROBABILITY CONTINUES TO LOOK RATHER LOW.
IN THE WAKE OF THE CLIPPER A SECOND SHORT WAVE ON A MORE NORTHERLY
TRACK WILL PASS ACROSS THE GREAT LAKES. ANY PRECIPITATION WITH
THIS WILL STAY NORTH OF THE FORECAST AREA. BUT SURFACE WINDS WILL
BRIEFLY BECOME FAVORABLE OFF LAKE MICHIGAN. SO THERE WILL BE A
CHANCE OF SNOW SHOWERS IN THE NORTHERN COUNTIES. HIGH PRESSURE
WILL FINALLY START TO BUILD IN THURSDAY NIGHT WITH CLOUDS
DIMINISHING.
FOR THE MOST PART USED A MOS BLEND FOR TEMPERA TUES WITH THE
EXCEPTION OF WEDNESDAY NIGHT WHEN WARMER NUMBERS WERE FAVORED.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
SURFACE HIGH PRESSURE WILL BE CENTERED OVER THE OHIO VALLEY AND
SOUTHEASTERN STATES ON FRIDAY MORNING. THE UPPER-LEVEL PATTERN WILL
FEATURE WEST-NORTHWEST FLOW ACROSS A LARGE PORTION OF THE
COUNTRY...WITH GRADUAL HEIGHT RISES OVER THE ILN FORECAST AREA. AN
AREA OF WEAK ISENTROPIC LIFT WILL PASS THROUGH THE SOUTHERN GREAT
LAKES AS WARM ADVECTION BEGINS ALOFT. FOR NOW...ANY PRECIPITATION
(LIKELY TO FALL AS SNOW) APPEARS THAT IT WILL REMAIN ACROSS NORTHERN
INDIANA AND NORTHERN OHIO.
ALTHOUGH WARM ADVECTION WILL OCCUR AT THE SURFACE HEADING INTO
SATURDAY...MODEL SOUNDINGS SUGGEST THAT AN INVERSION AND RELATIVELY
THICK LAYER OF MOISTURE WILL KEEP THINGS FROM BECOMING WELL MIXED
BELOW 5000 FEET. EVEN AS MOST OF THE COLUMN WILL REMAIN QUITE
DRY...CLOUDY CONDITIONS WITH LOW CEILINGS APPEAR FAIRLY LIKELY...AND
THERE IS EVEN WIDESPREAD MODEL AGREEMENT IN LIGHT PRECIPITATION
BEGINNING BY SATURDAY EVENING (SOMEWHAT UNUSUAL FOR WHAT LOOKS LIKE
A DRIZZLY PROFILE). WITH WARM ADVECTION AND PLENTIFUL CLOUD
COVER...MIN TEMPERATURES FOR SATURDAY NIGHT / SUNDAY MORNING WERE
INCREASED BY SEVERAL DEGREES FROM THE PREVIOUS FORECAST.
CHANCES FOR PRECIPITATION WILL INCREASE HEADING INTO SUNDAY...AS
FRONTOGENESIS OCCURS OVR THE OHIO VALLEY...WITH A STRENGTHENING
TEMPERATURE GRADIENT. A SURFACE FRONT IS EVENTUALLY FORECAST TO
DEVELOP...AND MOVE VERY SLOWLY SOUTHEAST THROUGH THE CWA HEADING
INTO MONDAY. TEMPERATURE FORECASTS ARE SOMEWHAT UNCERTAIN...GIVEN
THE SHARP GRADIENT...BUT ABOVE-NORMAL TEMPERATURES ARE LIKELY SOUTH
OF THE FRONT ON SUNDAY. A BRIEF PERIOD OF COOLER CONDITIONS CAN BE
EXPECTED ON MONDAY...WITH OCCASIONAL SHOWERS AND A POSSIBLE MIX WITH
SNOW ON MONDAY NIGHT. OVERALL MODEL AGREEMENT ON THE PRECIPITATION
PATTERNS WITH THIS FRONT ARE FAIRLY STRONG...WITH A SLIGHT TREND
TOWARD PRECIPITATION GETTING FURTHER SOUTH A LITTLE MORE QUICKLY ON
MONDAY INTO MONDAY NIGHT.
BY TUESDAY...STRONG SURFACE HIGH PRESSURE IS EXPECTED TO MOVE INTO
THE NORTHEASTERN STATES...ALLOWING FOR A QUICK RETURN TO SOUTHERLY
FLOW OVER MUCH OF THE EASTERN PART OF THE COUNTRY. THIS SHOULD ALLOW
FOR ANOTHER PERIOD OF MILD (ABOVE NORMAL) TEMPERATURES ON TUESDAY
AND ESPECIALLY ON WEDNESDAY.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
TAFS REMAIN WEDGED BETWEEN SYSTEMS THIS MORNING. MVFR CLOUDS
TRAPPED UNDER HIGH PRESSURE RIDGE HAVE RETREATED BACK INTO NRN
INDIANA AND NW OH...WHILE HIGH LEVEL CLOUDS ASSOCIATED WITH AN
EAST COAST STORM STREAM ACROSS THE REGION.
AS A H5 S/W DIGS OUT OF THE PLAINS IT WILL HELP THE FLOW TO PUSH
THE MVFR CLOUDS SEWD OVERNIGHT. MODEL TIME SECTIONS ARE INDICATING
THAT THEY COULD REACH KDAY AROUND SUNRISE. MODELS ONCE AGAIN ARE
STALLING THE SE ADVANCEMENT OF THE MVFR CIGS AROUND I-71...MAKING
THE CLOUD FORECAST TRICKY. BROUGHT THE MVFR CIGS INTO CVG/LUK FOR
A COUPLE OF HOURS LATE THIS MORNING...THEN PULLED THEM BACK TO THE
NW. WITH THE EAST COAST STORM HOLDING THINGS UP...CIGS ACROSS THE
EASTERN TAFS WILL LOWER LATER THIS MORNING...BUT SHOULD REMAIN
VFR.
AS EAST COAST STORM PULLS AWAY LATER TODAY...THE WEAK CLIPPER
SYSTEM DIVES INTO THE TN VALLEY...KEEPING CLOUDS ACROSS THE AREA.
OUTLOOK...MVFR CEILINGS POSSIBLE WEDNESDAY NIGHT INTO THURSDAY
NIGHT AND AGAIN SATURDAY. MVFR/IFR CEILINGS AND MVFR VISIBILITIES
POSSIBLE SATURDAY NIGHT INTO SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...HICKMAN
SHORT TERM...
LONG TERM...HATZOS
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS PORTLAND OR
909 PM PST TUE NOV 25 2014
.SYNOPSIS...A WARM FRONTAL BOUNDARY OVER WESTERN WASHINGTON WILL
CONTINUE TO LIFT NORTH TONIGHT AND WEDNESDAY. HIGH PRESSURE ALOFT
WEDNESDAY SHOULD BE STRONG ENOUGH TO KEEP MOST OF THE AREA
DRY...EXCEPT FOR SW WASHINGTON. THE NEXT WEATHER SYSTEM REACHES THE
COAST LATE WED EVENING AND THEN MOVES INLAND OVERNIGHT AND INTO
THANKSGIVING MORNING. MUCH COOLER AIR ASSOCIATED WITH THE NORTHERN
BRANCH OF THE JET STREAM IS FORECAST TO SPREAD OVER THE AREA THIS
WEEKEND...FOR ANOTHER ROUND OF EAST WIND IN THE COLUMBIA RIVER GORGE.
SNOW LEVELS WILL LOWER DRAMATICALLY THIS WEEKEND...BUT SLOWLY RISE
EARLY NEXT WEEK.
&&
.UPDATE...RADAR SHOWS LIGHT RAIN...MOSTLY OROGRAPHICALLY
INDUCED...OVER THE COAST RANGE AND SOUTH WASHINGTON AND NORTH OREGON
CASCADES...WITH RAIN RATES OF ONLY A FEW HUNDREDTHS OF AN INCH PER
HOUR. AS RIDGING BUILDS INTO THE AREA FROM THE SOUTH...RAIN WILL
TAPER OFF THROUGH WEDNESDAY. EXPECT THE WILLAMETTE VALLEY TO REMAIN
DRY THROUGH THE OVERNIGHT HOURS AND INTO WEDNESDAY. WITH CLEARING
SKIES PARTICULARLY IN THE SOUTH AND CENTRAL WILLAMETTE
VALLEY...SHOULD SEE SOME FOG LATER TONIGHT AND WEDNESDAY MORNING BUT
ANY VISIBILITY BELOW ABOUT 1/2 MILE SHOULD BE ISOLATED. FOR THE
FORECAST UPDATE...TOOK OUT POPS FOR TONIGHT AND WEDNESDAY IN THE
WILLAMETTE VALLEY AND TAPERED RAIN CHANCES ELSEWHERE OFF SLIGHTLY
FASTER. ALSO RAISED HIGH TEMPERATURES WEDNESDAY A COUPLE OF DEGREES
BASED ON TODAY`S OBSERVED HIGHS AND A PERSISTENT PATTERN.
FINALLY...HAVE INCREASED WINDS ALONG THE COAST TOMORROW NIGHT BASED
ON LATEST MODELS. EXPECT WINDY BUT SUB-WARNING CONDITIONS. BOWEN
.SHORT TERM (PREVIOUS DISCUSSION)...TONIGHT THROUGH FRIDAY...500 MB
RIDGE REMAINS CENTERED ALONG 130W WITH A BAROCLINIC ZONE RIDING OVER
THE TOP. KLGX RADAR INDICATING RETURNS OVER MUCH OF SW WA.
HOWEVER...ECHO INTENSITY HAS DIMINISHED AND THIS IS EVIDENT IN THE
LATEST 6-HR PRECIP AMOUNTS. RAINFALL RATES AS OF 21Z IN THE SW WA
CASCADES AND FOOTHILLS HAVE EASED TO AROUND ONE TENTH OR LESS. 24-HR
TOTALS GENERALLY 1 TO 3 INCHES...WITH SOME SNOTELS COMING IN WITH 3.5
INCHES. 500 MB HEIGHTS NEAR 570 DM COMBINED WITH 1000-500 MB
THICKNESS VALUES IN THE MID TO UPPER 550S AND 850 MB TEMPS 8-10C HAVE
RESULTED IN NEAR-RECORD DAYTIME TEMPERATURES IN THE WILLAMETTE
VALLEY. THE MILD AIR MASS WILL BE CONDUCING TO VALLEY FOG FORMATION
TONIGHT...ESPECIALLY WITH THE RELATIVELY HIGH DEW POINTS. FOG WILL
FAVOR THE SOUTH HALF OF THE AREA WHERE LESS CLOUD COVER IS EXPECTED.
THE THANKSGIVING FRONT IS STILL ON TRACK TO REACH THE COASTLINE LATE
WED EVENING THEN MIGRATE INLAND OVERNIGHT AND THANKSGIVING MORNING.
THE REMNANTS OF THE FRONTAL BOUNDARY STALL ACROSS THE INTERIOR
VALLEYS AND CASCADES THANKSGIVING NIGHT. THE GFS AND ECMWF HANDLE THE
QPF FIELD VALID 06Z FRI QUITE DIFFERENTLY. THE GFS SHOWS AN OBVIOUS
BREAK IN THE FRONTAL BOUNDARY...WITH SEPARATE QPF BULLS-EYES OVER FAR
SW OREGON AND ALSO IN THE S WA CASCADES AND FOOTHILLS. THE ECMWF SHOW
A MUCH LARGER SRN QPF AREA EXTENDING FURTHER N...TO THE CENTRAL
INTERIOR VALLEYS AND CASCADES. BY 12Z FRI THE ECMWF HAS A BROAD SWATH
OF QPF OVER THE ENTIRE FORECAST AREA WHILE THE GFS MAINTAINS THE TWO
SEPARATE AND DISTANT CORES. IN ANY EVENT...THE AIR MASS WILL REMAIN
QUITE MILD THROUGH THU NIGHT WITH SNOW LEVELS WELL
ABOVE THE CASCADE PASSES.
THINGS START TO CHANGE FRI AS BOTH THE ECMWF AND GFS SHOW THE
NORTHERN AND SOUTHERN JET STREAM BRANCHES PHASING TOGETHER. BOTH
MODELS HAVE A MUCH COLDER CANADIAN AIR MASS SAGGING S THROUGH NRN WA
FRI. MODELS DEVELOP AN AREA OF ENHANCED QPF ALONG THE REMNANT FRONTAL
BOUNDARY. THE EXACT LOCATION OF THIS BOUNDARY REMAINS IN QUESTION.
THE GFS HAS IT ALONG A LINE FROM NEWPORT TO ALBANY WHILE THE ECMWF
HAS IT A BIT MORE NORTH BUT WITH LESSER AMOUNTS. WEISHAAR
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...COMPLICATED PATTERN
EVOLVES FRIDAY NIGHT AND SAT WITH THE COLDER AIR CONTINUING TO SLIDE
S THROUGH WA AND INTO NRN OREGON. 12Z GFS MORE IN LINE WITH THE
PREVIOUS COUPLE OF ECMWF RUNS...DEPICTING A COLD AIR WEDGE IN THE
CENTRAL COLUMBIA GORGE BY 00Z SUN. LOOK FOR THE EAST WIND TO RETURN
AS WELL...BEGINNING SAT MORNING AND CONTINUING THROUGH THE WEEKEND.
BY 00Z SUN THE GFS HAS -8 TO -10C 850 MB AIR IN THE CENTRAL COLUMBIA
GORGE...WHILE THE ECMWF IS JUST A TOUCH WARMER. FORTUNATELY...THE
DRIER NLY FLOW WILL SHUNT PRECIP FURTHER TO THE S. A CLOSED LOW WELL
OF THE NRN CA COAST SAT STARTS TO DRIFT NE SAT NIGHT AND SUN. THERE
IS THE POTENTIAL FOR A DEFORMATION BAND OVER NRN CA TO DRIFT NWD LATE
SUN INTO MON. THIS COULD BE PROBLEMATIC AS THE MOISTURE OVERRUNS THE
COLD AIR....ESPECIALLY FOR THE COLUMBIA GORGE AND UPPER HOOD RIVER
VALLEY. WEISHAAR
&&
.AVIATION...CONDITIONS HAVE DRAMATICALLY IMPROVED OVER THE LAST
COUPLE HOURS FOR THE INLAND LOCATIONS WHILE THE COAST HAS LARGELY
REMAINED IFR OR WORSE THIS EVENING. MODELS HAVE NOT BEEN HANDLING
THE SITUATION WELL AT ALL AS ABUNDANT LOW LEVEL MOISTURE HAS
REMAINED. THE UPPER RIDGE WILL CONTINUE TO BUILD AS IT TRANSITS
THE REGION WITH SURFACE WINDS ON DECREASING. DEW POINTS ARE IN
THE 50S AT THIS HOUR BUT SHOULD LOWER SOME THIS EVENING. HAVE
DOUBTS DEW POINTS WILL BE ABLE TO KEEP AHEAD OF TEMPERATURES AND
EXPECT TO SEE FOG DEVELOP. CONFIDENCE IS FAR TOO
LOW...HOWEVER...FOR SPECIFIC AREAS AND DECIDED AGAIN INCLUSION IN
THE TAF PACKAGES ASIDE FROM KSLE AND KEUG. REGARDLESS...HAVE
REASONABLE CONFIDENCE LOW STRATUS WILL DEVELOP INLAND WHERE FOG
DOESN`T. DONT EXPECT MUCH IMPROVEMENT ABOVE IFR UNTIL PERHAPS
AFTER 19-21Z.
KPDX AND APPROACHES...VFR CIGS CURRENTLY BUT EXPECT LOW CLOUDS TO
BREAK UP SOME WITH ENOUGH CLEARING ALLOWING FOR A LOWER STRATUS
DECK TO DEVELOP OVERNIGHT. EXPECT A 015 TO 020 DECK WILL REMAIN
UNTIL AROUND 20Z BEFORE CLEARING OUT THROUGH 27/06Z JBONK
&&
.MARINE...WIND GUSTS ACROSS THE NORTHERN WATERS HAVE STAYED BELOW
SMALL CRAFT CRITERIA WITH THE HRRR MODEL HAVING THE BEST HANDLE
ON THE SITUATION AT THIS TIME. THAT MODEL DOES NOT BRING A THREAT
FOR CRITERIA LEVEL GUSTS BACK UP UNTIL AFTER 5 AM EARLY WEDNESDAY.
AS SUCH HAVE DROPPED THE SMALL CRAFT WIND ADVISORY FOR THE TIME
BEING. SEAS ARE ALSO RUNNING ABOUT A FOOT BELOW GUIDANCE AND THE
FORECAST SO HAVE ALSO LOWERED JUST A BIT.
THE CURRENT SOUTHWEST WINDS WILL BACK TO THE SOUTH AND INCREASE
AS A STRONG FRONT APPROACHES WEDNESDAY AFTERNOON. THIS FRONT WILL
LIKELY PRODUCE GALE FORCE WINDS WEDNESDAY NIGHT WITH THE PREVIOUS
SHIFT HAVING ISSUED A GALE WARNING.
ANOTHER FRONT IS EXPECTED TO BRUSH BY THE SOUTHERN WATERS FRIDAY.
THIS FRONT WILL APPROACH FROM THE SW AND THE MODELS VARY ON HOW
FAR NORTH IT WILL REACH...AND ON THE TIMING. THEREFORE...THERE IS
LOW CONFIDENCE FOR FRIDAY FORECAST. A LARGE LOW WILL DROP SOUTH
FROM THE GULF OF ALASKA FRIDAY AND SETTLE SW OF THE WATERS THIS
WEEKEND...AND GENERATE OFFSHORE WINDS THROUGH THE WEEKEND. THESE
WINDS WILL LIKELY RESULT IN ENHANCED GUSTS NEAR THE COASTAL
GAPS...POSSIBLY NEEDING A WIND HEADLINE. JBONK/TJ
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 4 AM TO 4 PM PST WEDNESDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
OUT 60 NM.
GALE WARNING FROM 4 PM WEDNESDAY TO 4 AM PST THURSDAY FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 5 AM TO 9
AM PST WEDNESDAY.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 4 PM TO
10 PM PST WEDNESDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1149 PM EST TUE NOV 25 2014
.SYNOPSIS...
HIGH PRESSURE WILL RETREAT TO THE NORTHEAST TONIGHT. LOW PRESSURE
FORMING OFF THE SOUTHEAST COAST WILL DEEPEN SIGNIFICANTLY AS IT
MOVES NORTHEASTWARD ALONG THE EAST COAST ON WEDNESDAY...BRINGING
SIGNIFICANT SNOW TO MUCH OF CENTRAL PENNSYLVANIA. ANOTHER SHOT OF
COLDER AIR WILL FOLLOW FOR THE END OF THE WEEK...BEFORE
TEMPERATURES MODERATE OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
LITTLE CHANGE TO THE GOING FORECAST THIS EVENING. HIGH PRESSURE
CENTERED ALONG THE IL/IN BORDER BUILDING EASTWARD THROUGH THE
OHIO VALLEY WITH RIDGE AXIS EXTENDING NEWD ALONG THE LAKE ERIE
SHORELINE TO LAKE ONTARIO. STRATUS IS PACKED AGAINST THE
ALLEGHENIES OVER NORTHWEST PA. MID AND HIGH CLOUDS HAVE OVERTAKEN
THE REMAINDER OF CENTRAL PA THIS EVENING...AND WILL BE THICKENING
AS THE NIGHT WEARS ON. TEMPERATURES HAVE FALLEN TO THE LOWER 30S
IN MOST PLACES AND WILL DROP A FEW MORE DEGREES ACROSS THE NORTH.
STAGE IS SET FOR A LIGHT TO MODERATE SNOWFALL ACROSS A GOOD PART
OF CENTRAL AND EAST CENTRAL PA. MINOR ADJUSTMENTS TO SNOWFALL MAP
THIS EVENING FOR QUICKER EXIT OF SNOWFALL WEDNESDAY AFTERNOON...
AND SLIGHTLY LESSER QPF ALONG THE WESTERN EDGE OF THE WARNINGS.
HRW-ARW SUGGESTS ACCUMULATING SNOWFALL IS OVER BY 21Z...EVEN
ACROSS THE EAST...AND IS THE MOST AGGRESSIVE IN PUSHING THE
ACCUMULATING SNOWFALL OUT OF MY CWA WED AFTERNOON. HAVE NUDGED
THINGS IN THAT DIRECTION...AS OTHER GUIDANCE IS ALSO FASTER...BUT
MAINTAINED A BLEND OF GUIDANCE MID TO LATE AFTERNOON.
FOR THE OVERNIGHT...PRECIP OVERSPREADING THE SOUTHERN TIER
COUNTIES QUICKLY AFTER 08Z...WITH QPF APPROACHING A TENTH OF AN
INCH BY 12Z. TEMPS ALOFT AND ON THE SURFACE SUGGEST THAT PRECIP
STARTING OVER SOUTHERN /ESPECIALLY SE/ AREAS LATE TONIGHT WILL
LIKELY BE AT LEAST A MIX OF RAIN AND SNOW WITH LIGHT SNOW ON THE
NORTHERN EDGE. SIMPLY...PRECIP WILL MOVE INTO SOUTHERN HALF OF CWA
BEFORE SUNRISE AND WILL BE LIGHT...BUT QUICKLY INTENSIFY DURING
THE MORNING RUSH HOUR ACROSS THE SOUTH.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WINTER STORM WARNINGS/ADVISORIES NOW IN EFFECT.
A LOW PRESSURE SYSTEM DEVELOPS AND INTENSIFIES AS IT TRACKS FROM
THE CAROLINA COAST AT 12Z WED TO OFF THE NJ COAST BY 00Z THU...
BRINGING BIGGEST IMPACTS TO CENTRAL PA DURING THE DAY WED.
CONFIDENCE IS GROWING IN THE STORM TRACK WITH GFS COMING IN LINE
WITH THE ECMWF CLOSER TO THE COAST...WHICH WILL PUSH THE QPF
SHIELD A BIT FURTHER WEST. PRECIP WILL BE ONGOING IN THE SOUTH BY
SUNRISE...AND SPREADING QUICKLY INTO THE CENTRAL AND NORTHEAST BY
MID MORNING. ANY RAIN WILL QUICKLY CHANGE TO SNOW IN THE SE AS
COLUMN COOLS. PERIOD OF HEAVIEST INTENSITY PRECIP WILL BE WED
MORNING THROUGH MID AFTERNOON...WHERE SNOW RATES COULD BE 1-2
INCHES PER HOUR IN THE WARNING AREA. LATEST WWD GRAPHICS CONTINUE
TO SHOW A SWATH OF 6-8 SNOWS OVER THE SERN 1/3 OR SO OF MY FCST
AREA. CONFIDENCE FOR SIG SNOWS UP INTO CENTRAL/NW PA NOT AS HIGH
GIVEN THE LACK OF A SIG EASTERLY LOW LEVEL WIND ANOMALY IN THE
ENSEMBLES...AND A SHORTWAVE SLIDING IN FROM THE WEST WHICH MAY
SHARPEN GRADIENT OF SNOW. BUT FOR A COUPLE INCHES OF SNOW AND
IMPACTS ON THE BUSIEST TRAVEL DAY OF THE YEAR WE STRUNG AN
ADVISORY OVER THE NORTHERN EDGE OF THE WARNING AREA.
SNOW SHOULD TAPER OFF QUICKLY BY LATE WED AFT/WED EVE AS STORM
QUICKLY MOVES INTO NEW ENGLAND. FLOW TRANSITIONS BACK TO A NW FETCH
ACROSS THE LAKES...WITH LIGHT SCT SNOW SHOWERS POSS BY THU MORNING
IN THE UPSLOPE OF THE WESTERN HIGHER TERRAIN.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
UPPER TROFFING OVER THE EASTERN THIRD OF THE COUNTRY AT THE START
OF THE LONG TERM PERIOD IS FORECAST TO FLATTEN OUT INTO AN
EXTENSIVE WEST TO EAST ZONAL FLOW PATTERN COVERING MUCH OF NORTH
AMERICA. HEIGHTS OVER THE NORTHEASTERN U.S. ARE THEN FORECAST TO
RISE FROM LATE IN THE WEEKEND ONWARD AS THE CABOOSE IN THE CURRENT SHORTWAVE
TRAIN EXITS THE EAST COAST ON FRIDAY AND ENERGY APPROACHING THE
PACIFIC COAST CLOSES OFF AND BUILDS HEIGHTS OVER THE WESTERN AND
CENTRAL U.S.
A SHOT OF COLD AIR WILL MOVE INTO THE REGION FOR THURSDAY AND
FRIDAY BEHIND THE AFOREMENTIONED CABOOSE SHORTWAVE. THIS WAVE MAY
ALSO SUPPORT AN AREA OF PCPN MOVING WEST TO EAST ACROSS THE STATE
THANKSGIVING DAY. ADDITIONALLY...THIS PUSH OF ENERGY/COLD AIR
SHOULD GENERATE THE USUAL POST FRONTAL LAKE AND OROGRAPHICALLY
ENHANCED SNOW SHOWERS IN THE WAKE OF THE DEPARTING STORM SYSTEM
WITH WESTERN AND NORTHERN AREAS SEEING THE BEST CHANCE OF
SCATTERED LIGHT SNOWS...WHILE THE REST OF THE REGION SEES LITTLE
OR NO SNOW SHOWER ACTIVITY AT ALL.
A BROAD WSW FLOW ALOFT ASSOCIATED WITH THE RISING HEIGHTS WILL
MAKE THIS COLD SHOT TEMPORARY WITH WARMER AIR BEGINNING TO MAKE A
RETURN BY SATURDAY. HIGHS WILL RETURN TO NEAR OR EVEN A TICK ABOVE
NORMAL BY THE WEEKEND BEFORE COOLER AIR APPROACHES AGAIN FOR EARLY
NEXT WEEK.
A FRONTAL SYSTEM IN ADVANCE OF THE WARM AIR WILL MOVE ACROSS THE
STATE ON SUNDAY...BRINGING THE BEST CHANCE OF PCPN DURING THE
PERIOD.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
26/03Z UPDATE...MINOR CHANGES TO ONSET OF PCPN. PROJECTED ONSET
MAY BE A BIT FAST WITH THE LATEST HRRR FAVORING THE 12-15Z WINDOW
ACROSS THE SRN AIRFIELDS. MDL SOUNDINGS AND HIGH RES GUIDANCE
STILL SHOW RELATIVELY QUICK CHANGEOVER FROM RAIN-TO-SNOW OVER THE
SE TERMINALS WITH ALL SNOW PTYPES EXPANDING NWD TO FIG-IPT LINE BY
15Z. FINALLY...BFD REMAINS ON EDGE OF LOW CLOUDS AND MVFR CIGS
ACROSS NE OH/NW PA INTO WRN NY.
26/00Z...LOW PRESSURE DEVELOPING OFF THE SOUTHEAST COAST LATE
TONIGHT WILL STRENGTHEN AS IT LIFTS NWD JUST OFF THE EAST COAST
THROUGH WED NGT. EXPECT RAPIDLY DETERIORATING CONDS FROM SOUTH TO
NORTH DURING THE PREDAWN AND EARLY MORNING HOURS AS SNOW
OVERSPREADS THE AIRSPACE. PCPN WILL LKLY BEGIN AS A MIX IN THE
MDT/LNS AREA BEFORE CHANGING TO ALL SNOW. MOST INTENSE SNOWFALL
RATES AND REDUCED VSBYS WILL BE OVER THE SERN AIRSPACE WITH RATES
UP TO 2"/HR WITH FLGT CATS AOB AIRFIELD MINS. HIGH CONFIDENCE IN
WIDESPREAD IFR CONDS DUSK-DAWN BEFORE SNOW ENDS FROM SW TO NE BY
WED NGT. LOW CIGS SHOULD PERSIST OVER THE WRN 1/3 OF THE AREA WED
NGT WITH MARGINAL IMPROVEMENT ELSEWHERE.
OUTLOOK...
THU...IFR/MVFR WITH OCNL -SHSN WRN 1/3. VFR TO MVFR CIGS
CNTRL/EAST.
FRI...AM MVFR/-SHSN NW...OTHERWISE BCMG VFR.
SAT-SUN...MAINLY VFR. -SHRA PSBL.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 3 AM WEDNESDAY TO 4 AM EST THURSDAY
FOR PAZ019-042-045-046-049>053.
WINTER WEATHER ADVISORY FROM 3 AM WEDNESDAY TO 4 AM EST
THURSDAY FOR PAZ012-017-018-037-041.
WINTER STORM WARNING FROM 3 AM WEDNESDAY TO MIDNIGHT EST
WEDNESDAY NIGHT FOR PAZ024>028-033>036-056>059-063>066.
&&
$$
SYNOPSIS...RXR/STEINBUGL
NEAR TERM...DEVOIR/RXR
SHORT TERM...RXR
LONG TERM...LA CORTE/GARTNER
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1134 PM MST TUE NOV 25 2014
.UPDATE...
ISSUED AT 1129 PM MST TUE NOV 25 2014
WINDS ARE DECREASING ACROSS FAR NWRN SD SO HAVE CANCELLED THE WIND
ADVISORY FOR THAT AREA. WILL KEEP THE ADVISORY GOING FOR WCNTRL SD
FOR THE TIME BEING BUT THAT MAY END UP BEING CANCELLED EARLY AS
WELL.
UPDATE ISSUED AT 916 PM MST TUE NOV 25 2014
SNOW IS DECREASING FROM NORTH TO SOUTH AS PRES RISES MOVE IN FROM
THE NORTH BEHIND CDFNT. THE MDT/HEAVY BAND OF SNOW OVER THE BLKHLS
IS DIMINISHING WITH LITTLE ADDITIONAL ACCUMS EXPECTED THE REST OF
THE NIGHT. WINDS SHOULD REMAIN QUITE GUSTY MUCH OF THE NIGHT AND
WILL CONTINUE THE WIND ADVISORY.
&&
.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 205 PM MST TUE NOV 25 2014
THE LATEST WATER VAPOR IMAGES AND RAP ANALYSES INDICATED A LARGE
TROUGH OVER THE CNTRL/ERN CONUS WITH A RIDGE OVER THE WEST COAST.
A POTENT SHORT-WAVE TROUGH WAS MOVING ACROSS ERN MT INTO NWRN
SD...AIDED BY A 150-KT UPPER JET. SCT RAIN/SNOW SHOWERS WERE
ACROSS MUCH OF WRN SD AND NERN WY...BUT WITH A DOWNSLOPE HOLE OVER
PARTS OF SWRN SD. AREA WEBCAMS SHOWED AROUND ONE INCH OF SNOW OVER
NERN WY...A TRACE OVER NWRN SD...AND 1-2 INCHES IN THE NRN BLKHLS.
A SFC LOW OVER WRN ND WAS ASSOCIATED WITH 2-5MB/3HR PRES RISES AS
IT MOVED SOUTHEAST...WITH NORTHWEST WINDS OF 20-35 MPH BEHIND THE
LOW MOVING INTO NWRN SD.
THERE IS DECENT MODEL AGREEMENT IN THE SHORT TERM THROUGH AT LEAST
12Z THU. HEIGHTS WILL BE RISING THROUGH THE PERIOD WITH THICKNESSES
RISING WED THROUGH THU. FOR TNGT...THE SHORT-WAVE TROUGH MOVES TO
NERN KS AS THE SFC LOW MOVES TO SWRN IA. THIS WILL TAKE MOST OF THE
PRECIP SOUTHEAST OF THE AREA THIS EVNG...BUT NORTHWEST WINDS WILL
INCREASE ACROSS MOST OF NWRN INTO SCNTRL SD. THE PREVIOUS WIND ADVY
LOOKS GOOD AND WILL NOT CHANGE. BLSN IS EXPECTED TO BE MINIMAL GIVEN
THE WARM TEMPS AND LIMITED SNOWFALL. A LOW-LEVEL BAROCLINIC ZONE
WILL SETUP OVER THE WRN CWA SO WILL KEEP A CHANCE OF SNOW GOING
THERE. COLDER AIR ALSO WILL FLOW INTO THE CWA TNGT GIVEN STRONG COLD
ADVECTION.
ON WED THE BAROCLINIC ZONE INTENSIFIES ACROSS THE WRN CWA...WITH
WARM ADVECTION AND FRONTOGENESIS AIDING IN MESOSCALE LIFT ON THE
ANTICYCLONIC SIDE OF THE UPPER JET. DESPITE WEAK UPPER FORCING...THE
LOW-LEVEL FORCING AND NEARLY SATURATED PROFILES SHOULD LEAD TO SNOW
OVER NERN WY INTO WRN SD. THIS WILL SPREAD NEWD WED NGT AS UPPER
HEIGHTS CONTINUE TO BUILD AND LOW-LEVEL WARM ADVECTION INTENSIFIES.
SREF PTYPE PROBABILITIES AND NAM VERTICAL PROFILES SUPPORT A CHANCE
OF FZRA OVER PARTS OF NWRN SD LATE WED NGT INTO THU MRNG...SO HAVE
ADDED THAT TO THE FCST.
&&
.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014
SNOW/FREEZING RAIN WILL GRADUALLY EXIT THE AREA ON THANKSGIVING...
LINGERING THE LONGEST OVER NW SD.
THE TRICKIEST PART OF THE LONG TERM FORECAST WILL BE TEMPS...
PARTICULARLY THURSDAY AND SATURDAY. LOW AMPLITUDE RIDGING WILL
DEVELOP THANKSGIVING DAY ACROSS THE ROCKIES INTO THE NORTHERN
PLAINS. STRONG WARM AIR ADVECTION WILL DEVELOP WEDNESDAY NIGHT
INTO THURSDAY PUSHING THE WARM FRONT NE INTO THE CENTRAL DAKOTAS.
THE RESULT WILL BE DRY AND MUCH WARMER WEATHER FOR THANKSGIVING
AND FRIDAY. JUST HOW WARM THE SD PLAINS WILL GET ON THURSDAY
DEPENDS ON THE MOVEMENT OF THE WARM FRONT...AS MODELS HAVE A 10-15
DEGREE SPREAD ACROSS THAT AREA. CURRENTLY HAVE HIGHS RANGING FROM
THE 30S ACROSS NW SD TO THE MID 50S IN PORTIONS OF NE WY AND SW
SD. ON FRIDAY...HIGHS WILL REACH THE UPPER 40S TO MID 50S.
THE NEXT COLD FRONT WILL PASS THROUGH THE AREA SATURDAY AS A SHALLOW
TROUGH CROSSES SRN CANADA INTO MT/ND. AGAIN HIGHS WILL DEPEND ON THE
POSITIONING OF THE FRONT...BUT WILL MOST LIKELY BE REACHED IN THE
MORNING...AS TEMPS WILL BE DROPPING THROUGH THE DAY INTO THE TEENS
AND 20S...AND THEN SINGLE DIGITS OVERNIGHT. GFS AND ECMWF ENSEMBLES
HAVE A 45-50 DEGREE SPREAD FOR THE HIGHS ON SATURDAY...AND ABOUT A
30 DEGREE SPREAD FOR LOWS...SO THERE IS MUCH UNCERTAINTY WITH THE
TEMPERATURE FORECAST. SOME LIGHT SNOW CAN BE EXPECTED TO MOVE
SOUTHWARD BEHIND THE COLD FRONT SATURDAY INTO SATURDAY NIGHT.
WELL BELOW AVERAGE TEMPS ARE EXPECTED SUNDAY...WITH SOME LINGERING
LIGHT SNOW POSSIBLE. THEN MODELS SHOW WARMER AIR ADVECTING BACK IN
EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 916 PM MST TUE NOV 25 2014
WINDS WILL GUST OVER 40KTS AT TIMES TONIGHT...ESPECIALLY OVER NWRN
SD. -SN WILL CONTINUE AT TIMES TONIGHT INTO WED...ESPECIALLY OVER
NERN WY AND FAR WRN SD. MVFR/IFR CIGS WILL CONTINUE TO SPREAD SWD
ACRS THE REGION TONIGHT BEHIND THE CDFNT...AND CONTINUE THROUGH
THE DAY ON WED...WITH SOME LIFR CONDITIONS POSSIBLE ACRS NERN WY
INTO THE NRN BLKHLS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 5 AM MST WEDNESDAY FOR SDZ014-026-031-032-
043-072-073.
WY...NONE.
&&
$$
UPDATE...JOHNSON
SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
921 PM MST TUE NOV 25 2014
.UPDATE...
ISSUED AT 916 PM MST TUE NOV 25 2014
SNOW IS DECREASING FROM NORTH TO SOUTH AS PRES RISES MOVE IN FROM
THE NORTH BEHIND CDFNT. THE MDT/HEAVY BAND OF SNOW OVER THE BLKHLS
IS DIMINISHING WITH LITTLE ADDITIONAL ACCUMS EXPECTED THE REST OF
THE NIGHT. WINDS SHOULD REMAIN QUITE GUSTY MUCH OF THE NIGHT AND
WILL CONTINUE THE WIND ADVISORY.
&&
.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 205 PM MST TUE NOV 25 2014
THE LATEST WATER VAPOR IMAGES AND RAP ANALYSES INDICATED A LARGE
TROUGH OVER THE CNTRL/ERN CONUS WITH A RIDGE OVER THE WEST COAST.
A POTENT SHORT-WAVE TROUGH WAS MOVING ACROSS ERN MT INTO NWRN
SD...AIDED BY A 150-KT UPPER JET. SCT RAIN/SNOW SHOWERS WERE
ACROSS MUCH OF WRN SD AND NERN WY...BUT WITH A DOWNSLOPE HOLE OVER
PARTS OF SWRN SD. AREA WEBCAMS SHOWED AROUND ONE INCH OF SNOW OVER
NERN WY...A TRACE OVER NWRN SD...AND 1-2 INCHES IN THE NRN BLKHLS.
A SFC LOW OVER WRN ND WAS ASSOCIATED WITH 2-5MB/3HR PRES RISES AS
IT MOVED SOUTHEAST...WITH NORTHWEST WINDS OF 20-35 MPH BEHIND THE
LOW MOVING INTO NWRN SD.
THERE IS DECENT MODEL AGREEMENT IN THE SHORT TERM THROUGH AT LEAST
12Z THU. HEIGHTS WILL BE RISING THROUGH THE PERIOD WITH THICKNESSES
RISING WED THROUGH THU. FOR TNGT...THE SHORT-WAVE TROUGH MOVES TO
NERN KS AS THE SFC LOW MOVES TO SWRN IA. THIS WILL TAKE MOST OF THE
PRECIP SOUTHEAST OF THE AREA THIS EVNG...BUT NORTHWEST WINDS WILL
INCREASE ACROSS MOST OF NWRN INTO SCNTRL SD. THE PREVIOUS WIND ADVY
LOOKS GOOD AND WILL NOT CHANGE. BLSN IS EXPECTED TO BE MINIMAL GIVEN
THE WARM TEMPS AND LIMITED SNOWFALL. A LOW-LEVEL BAROCLINIC ZONE
WILL SETUP OVER THE WRN CWA SO WILL KEEP A CHANCE OF SNOW GOING
THERE. COLDER AIR ALSO WILL FLOW INTO THE CWA TNGT GIVEN STRONG COLD
ADVECTION.
ON WED THE BAROCLINIC ZONE INTENSIFIES ACROSS THE WRN CWA...WITH
WARM ADVECTION AND FRONTOGENESIS AIDING IN MESOSCALE LIFT ON THE
ANTICYCLONIC SIDE OF THE UPPER JET. DESPITE WEAK UPPER FORCING...THE
LOW-LEVEL FORCING AND NEARLY SATURATED PROFILES SHOULD LEAD TO SNOW
OVER NERN WY INTO WRN SD. THIS WILL SPREAD NEWD WED NGT AS UPPER
HEIGHTS CONTINUE TO BUILD AND LOW-LEVEL WARM ADVECTION INTENSIFIES.
SREF PTYPE PROBABILITIES AND NAM VERTICAL PROFILES SUPPORT A CHANCE
OF FZRA OVER PARTS OF NWRN SD LATE WED NGT INTO THU MRNG...SO HAVE
ADDED THAT TO THE FCST.
&&
.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 205 PM MST TUE NOV 25 2014
SNOW/FREEZING RAIN WILL GRADUALLY EXIT THE AREA ON THANKSGIVING...
LINGERING THE LONGEST OVER NW SD.
THE TRICKIEST PART OF THE LONG TERM FORECAST WILL BE TEMPS...
PARTICULARLY THURSDAY AND SATURDAY. LOW AMPLITUDE RIDGING WILL
DEVELOP THANKSGIVING DAY ACROSS THE ROCKIES INTO THE NORTHERN
PLAINS. STRONG WARM AIR ADVECTION WILL DEVELOP WEDNESDAY NIGHT
INTO THURSDAY PUSHING THE WARM FRONT NE INTO THE CENTRAL DAKOTAS.
THE RESULT WILL BE DRY AND MUCH WARMER WEATHER FOR THANKSGIVING
AND FRIDAY. JUST HOW WARM THE SD PLAINS WILL GET ON THURSDAY
DEPENDS ON THE MOVEMENT OF THE WARM FRONT...AS MODELS HAVE A 10-15
DEGREE SPREAD ACROSS THAT AREA. CURRENTLY HAVE HIGHS RANGING FROM
THE 30S ACROSS NW SD TO THE MID 50S IN PORTIONS OF NE WY AND SW
SD. ON FRIDAY...HIGHS WILL REACH THE UPPER 40S TO MID 50S.
THE NEXT COLD FRONT WILL PASS THROUGH THE AREA SATURDAY AS A SHALLOW
TROUGH CROSSES SRN CANADA INTO MT/ND. AGAIN HIGHS WILL DEPEND ON THE
POSITIONING OF THE FRONT...BUT WILL MOST LIKELY BE REACHED IN THE
MORNING...AS TEMPS WILL BE DROPPING THROUGH THE DAY INTO THE TEENS
AND 20S...AND THEN SINGLE DIGITS OVERNIGHT. GFS AND ECMWF ENSEMBLES
HAVE A 45-50 DEGREE SPREAD FOR THE HIGHS ON SATURDAY...AND ABOUT A
30 DEGREE SPREAD FOR LOWS...SO THERE IS MUCH UNCERTAINTY WITH THE
TEMPERATURE FORECAST. SOME LIGHT SNOW CAN BE EXPECTED TO MOVE
SOUTHWARD BEHIND THE COLD FRONT SATURDAY INTO SATURDAY NIGHT.
WELL BELOW AVERAGE TEMPS ARE EXPECTED SUNDAY...WITH SOME LINGERING
LIGHT SNOW POSSIBLE. THEN MODELS SHOW WARMER AIR ADVECTING BACK IN
EARLY NEXT WEEK POTENTIALLY RESULTING IN NEAR AVERAGE TEMPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 916 PM MST TUE NOV 25 2014
WINDS WILL GUST OVER 40KTS AT TIMES TONIGHT...ESPECIALLY OVER NWRN
SD. -SN WILL CONTINUE AT TIMES TONIGHT INTO WED...ESPECIALLY OVER
NERN WY AND FAR WRN SD. MVFR/IFR CIGS WILL CONTINUE TO SPREAD SWD
ACRS THE REGION TONIGHT BEHIND THE CDFNT...AND CONTINUE THROUGH
THE DAY ON WED...WITH SOME LIFR CONDITIONS POSSIBLE ACRS NERN WY
INTO THE NRN BLKHLS.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY UNTIL 5 AM MST WEDNESDAY FOR SDZ014-025-026-031-
032-043-072-073.
WIND ADVISORY UNTIL 1 AM MST WEDNESDAY FOR SDZ001-002-012-013.
WY...NONE.
&&
$$
UPDATE...JOHNSON
SHORT TERM...BUNKERS
LONG TERM...POJORLIE
AVIATION...JOHNSON
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1029 PM MST TUE NOV 25 2014
.UPDATE...
ISSUED AT 1016 PM MST TUE NOV 25 2014
WYDOT SENSORS OVER THE SOUTH LARAMIE RANGE LATE THIS EVENING ARE
REPORTING WIND SPEEDS IN THE 30 MPH RANGE OVER THE SUMMIT. LATEST
WRKHGT PRODUCT EASING CRAIG TO CASPER 850 AND 700MB HEIGHT
GRADIENTS OVERNIGHT BEFORE PICKING THEM UP AGAIN TOMORROW
AFTERNOON. WENT AHEAD AND CANCELLED THE HGH WIND WARNING FOR THE
SOUTH LARAMIE RANGE EARLY WITH THIS UPDATE. DID KEEP THE ARLINGTON
ZONE GOING AS FORECAST AS THEIR WINDS OUT THERE ARE GUSTING TO THE
LOW 40S. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 805 PM MST TUE NOV 25 2014
SEEING RAPIDLY COOLING CLOUD TOPS ON IR IMAGERY ACROSS NORTH
CENTRAL WYOMING THIS EVENING JUST NORTH OF CONVERSE COUNTY.
WEBCAMS NEAR NATURAL BRIDGE SHOWING I-25 SNOW COVERED WITH REDUCED
VISIBILITIES. GOT A REPORT OUT OF DOUGLAS OF 3 INCHES OF SNOW...SO
WENT AHEAD AND ADDED CONVERSE COUNTY TO THE WINTER WEATHER
ADVISORY. LOOKING AT WIND REPORTS FURTHER SOUTH...FRONT ALREADY
HAS MADE IT THROUGH BORDEAUX AND WINDS OUT WEST IN CARBON AND
NORTHERN ALBANY COUNTIES CONTINUE TO DECREASE. WENT AHEAD AND
CANCELLED THE HIGH WIND WARNING FOR THESE AREAS EARLY. UPDATES
HAVE BEEN SENT.
UPDATE ISSUED AT 700 PM MST TUE NOV 25 2014
LOOKING AT AREA WYDOT AND METAR OBSERVATIONS...DECIDED TO LET THE
HIGH WIND WARNINGS FOR MOST OF LARAMIE COUNTY...THE LARAMIE VALLEY
AND THE SARATOGA AREA EXPIRE ON TIME AT 7 PM THIS EVENING.
PROBABLY COULD HAVE TAKEN BORDEAUX OUT OF THE WARNING AS
WELL...BUT WILL WAIT ANOTHER HOUR OR SO TO SEE WHAT THEIR WINDS DO
UP THERE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 342 PM MST TUE NOV 25 2014
FORECAST REMAINS ON TRACK FOR THE MOST PART REGARDING STRONG WINDS
AND SNOW PER UPDATED DISCUSSION ISSUED EARLIER THIS AFTERNOON. THE
COLD FRONT HAS MOVED SOUTH ABOUT HALFWAY-THREE QUARTERS THROUGH
THE CWA AT THIS HOUR...WITH SNOW AND LIGHT SHOWERS INCREASING IN
COVERAGE AS IT PASSES THROUGH. RAIN SHOULD QUICKLY CHANGE TO SNOW
AS COOLER AIR FILTERS IN BEHIND THE FRONT. STRONG WINDS CONTINUE
THIS AFTERNOON MAINLY ALONG AND WEST OF THE LARAMIE RANGE WITH
WINDS A BIT CALMER ACROSS THE WYO PLAINS AT THIS HOUR. WILL LEAVE
WIND HIGHLIGHTS AS IS AT LEAST UNTIL FRONTAL PASSAGE.
MADE A FEW CHANGES TO THE WINTER WEATHER ADVISORY TO INCLUDE THE
SUMMIT AND EXTEND THE TIMING OF THE HIGHLIGHT TO THE AFTERNOON TO
ACCOUNT FOR BLOWING SNOW CONCERNS. AFTER A FURTHER LOOK AT THE
WIND PROGS FOR TOMORROW MORNING...AND DISCUSSION WITH OUR
PARTNERS ABOUT POTENTIAL TRAVEL IMPACTS UP AT THE SUMMIT WITH THE
COMBO OF SNOW AND WIND...FELT IT NECESSARY TO ADJUST THE ADVISORY
FOR THESE TWO CHANGES. 2 TO 5 INCHES STILL LOOKS TO BE ON TRACK
FOR SNOW TOTALS ACROSS THE AREA...BUT WINDS OF 15 TO 20 MPH
INCREASING TO 25 TO 35 MPH WITH HIGHER GUSTS BY SUNRISE UP NEAR
THE SUMMIT AS THE SNOW ENDS WILL LIKELY CAUSE SOME TRAVEL PROBLEMS
THROUGH THE MORNING DUE TO BLOWING AND DRIFTING OF SNOW. WINDS
WILL INCREASE ACROSS THE EASTERN FOOTHILLS AND ADJACENT PLAINS IN
THE MORNING AS WELL WHERE THE HEAVIER SNOW IS EXPECTED TO
FALL...SO COULD SEE SOME HAZARDOUS TRAVEL ALONG I-25 AND I-80
APPROACHING CHEYENNE DUE TO BLOWING AND DRIFTING OF SNOW.
EXTENDING THE TIMING THROUGH 2 PM AS BLOWING SNOW SHOULD BE LESS
OF A CONCERN IN THE AFTERNOON AS WINDS AND SOME HEATING THROUGH
THE DAY WORK OVER THE SNOWPACK. BREEZY TO WINDY CONDITIONS WILL
CONTINUE THROUGH WEDNESDAY NIGHT AS THE LLVL GRADIENT REMAINS
TIGHT IN THE WAKE OF THE DEPARTING FRONT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 342 PM MST TUE NOV 25 2014
MAIN STORY THROUGH LATE WEEK WILL BE HIGH WIND POTENTIAL IN THE MAIN
WIND CORRIDORS ACROSS SOUTHEAST WY. MEDIUM RANGE MODELS ARE STILL IN
GOOD AGREEMENT WITH A FAVORABLE PATTERN FOR STRONG GUSTS WITH AN H25
JET CORE REMAINING ANCHORED OVER THE NORTHERN ROCKIES WITH WEAK SFC
LOW PRESSURE SPREADING ACROSS MT INTO THE DAKOTAS. THIS PRETTY MUCH
KEEPS THE LLVL CAG-CPR GRADIENTS BETWEEN 60 AND 70 METERS THROUGH AT
LEAST FRIDAY. WITH THE GFS SHOWING A WIDESPREAD AREA OF 50 KT 700 MB
FLOW...INCREASED WINDS AND KEPT GUSTS RIGHT AROUND WARNING CRITERIA
THROUGH THE END OF THE WEEK FOR ARLINGTON/BORDEAUX AND I80 BETWEEN
LARAMIE AND CHEYENNE. ASIDE FROM THE WIND...CONFIDENCE IS HIGH IN A
RATHER WARM THANKSGIVING. BOTH THE GFS AND ECMWF SUGGEST H7 TEMPS IN
THE 2-3 DEG C RANGE. WESTERLY DOWNSLOPE WINDS WOULD FAVOR THE WARMER
MOS WITH HIGHS AROUND 60-65 F OVER THE PLAINS ON THU/FRI. A CANADIAN
SFC HIGH WILL BEGIN TO SINK SOUTH INTO THE NORTHERN HIGH PLAINS INTO
SAT...PUSHING THE BEST SFC PRESSURE GRADIENTS SOUTH OF THE CWA AND
PROVIDING A BREAK FROM HIGH WINDS BY LATE IN THE WEEKEND. A POTENT
SHORTWAVE WILL SWING ACROSS THE DAKOTAS ON SUN...SENDING A BACKDOOR
FRONT SOUTHWESTWARD. SOME DIFFERENCES IN THE GFS/ECM WITH THE DEPTH
OF COLD AIR. THE COLDER ECMWF SHOWS TEMPS AROUND -9C AT 700 MB IN
THE NORTHERN PANHANDLE AT 18Z SUN...WHEREAS THE GFS ONLY SHOWS -3C
AT THE SAME TIME. STILL LEANED MORE TOWARD THE ECMWF AND MADE FEW
CHANGES TO THE PREVIOUS FCST. GENERALLY A DRY PERIOD WITH A LACK OF
ANY SUBSTANTIAL DYNAMICS. PRECIP CHANCES LOOK TO INCREASE ALONG AND
WEST OF THE LARAMIE RANGE ON TUE AND WED WITH THE RETURN OF MOIST
SOUTHWEST FLOW ALOFT PER MEDIUM RANGE GUIDANCE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1016 PM MST TUE NOV 25 2014
LATEST HRRR GUIDANCE USED FOR THIS TAF PACKAGE. FRONT CONTINUES TO
PUSH SOUTHWEST OVERNIGHT WITH SNOW DEVELOPING WEST OF THE LARAMIE
RANGE. LARAMIE ALREADY DOWN TO LESS THAN 2 MILES IN SNOW AND WOULD
EXPECT THIS TO CONTINUE THROUGH 12Z BEFORE IMPROVING. HRRR SHOWING
KRWL STAYING DOWN...THOUGH MOST LIFR/IFR SOUTH OF THE AIRPORT.
ANOTHER WINDY DAY FOR WEDNESDAY.
&&
.FIRE WEATHER...
ISSUED AT 342 PM MST TUE NOV 25 2014
WINDY CONDITIONS WILL DIMINISH TONIGHT AS A COLD FRONT MOVES
THROUGH THE AREA. A PERIOD OF SNOW WILL FALL TONIGHT WITH
ACCUMULATIONS OF 2 TO 5 INCHES EXPECTED ACROSS LOWER ELEVATIONS
IN SOUTHEAST WYOMING. THE SNOWY AND SIERRA MADRE RANGES WILL SEE
UP TO ANOTHER FOOT OF SNOW THROUGH TONIGHT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 7 AM MST WEDNESDAY FOR WYZ112-114.
HIGH WIND WARNING UNTIL 2 PM MST WEDNESDAY FOR WYZ110.
WINTER WEATHER ADVISORY UNTIL 2 PM MST WEDNESDAY FOR WYZ101-103-
106-107-116>119.
NE...NONE.
&&
$$
UPDATE...GCC
SHORT TERM...RJM
LONG TERM...CLH
AVIATION...GCC
FIRE WEATHER...RJM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
553 AM EST WED NOV 26 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 450 PM EST TUE NOV 25 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN AMPLIFIED PATTERN OVER
NAMERICA WITH RIDGING ALONG/JUST OFF THE W COAST...A TROF EXTENDING
FROM N OF HUDSON BAY TO TX AND A RIDGE JUST OFF THE EAST COAST.
SHORTWAVE THAT PROVIDED WIDESPREAD SYNOPTIC SNOW AS WELL AS LAKE
ENHANCED SNOW ACROSS THE FCST AREA LAST NIGHT HAS SHIFTED NE INTO
QUEBEC. UPSTREAM...NEXT SHORTWAVE IS DIVING SE INTO THE DAKOTAS. A
LESS DEFINED SHORTWAVE TROF IS FARTHER N OVER NRN PORTIONS OF
MANITOBA/SASKATCHEWAN. DRYING AIR MASS...LOWERING INVERSION AND LOW
LEVEL WINDS BECOMING MORE ANTICYCLONIC WITH SFC HIGH PRES THAT IS
NOW NOSING INTO WRN UPPER MI HAVE RESULTED IN A STEADY DIMINISHING
TREND/SHIFTING OF LINGERING LES THIS AFTN. IN FACT...OVER THE
W...THERE MAY NOT BE MUCH MORE THAN SCT FLURRIES REMAINING. LAKE
EFFECT CLOUD COVER IS ALSO DIMINISHING WITH CLR SKIES NOW BEING
NOTED AROUND KIWD. TO THE W...CLOUDS IN ADVANCE OF AFOREMENTIONED
SHORTWAVES ARE SLOWLY MOVING ACROSS NRN MN.
MAIN FCST CONCERNS IN THE SHORT TERM ARE LES TRENDS TONIGHT...MIN
TEMPS TONIGHT WITH A PROBABLE PERIOD OF CLR/PARTLY CLOUDY SKIES IN
MANY AREAS AND THEN NEXT ROUND OF HEAVIER LES THAT WILL BEGIN TO
ENTER THE PICTURE WED AFTN AS SHORTWAVE TROF SWINGS SE TOWARD THE
UPPER LAKES.
TONIGHT...ARRIVAL OF WEAK SFC HIGH PRES RIDGE COMBINED WITH
STRENGTHENING LAND BREEZES WILL CONTINUE TO SHIFT LINGERING LES
OFFSHORE. OVER THE E...SHIFTING LES SHOULD BE OFFSHORE NO LATER THAN
AROUND MIDNIGHT. OVER THE W...ALTHOUGH THERE IS PROBABLY NOT MUCH
MORE THAN FLURRIES CURRENTLY REMAINING...NOCTURNAL COOLING AND LAND
BREEZE DEVELOPMENT RESULTING IN INCREASING CONVERGENCE SHOULD FAVOR
SOME REDEVELOPMENT OF LES DURING THE NIGHT. AMONG THE HIGH RES
MODELS...THERE IS DISAGREEMENT IN WHETHER SE MOVING SFC TROF WILL
SINK FAR ENOUGH S TO KEEP LES OVER THE KEWEENAW. AT THIS POINT...
BELIEVE SW FLOW ENHANCED BY LAND BREEZE WILL PUSH LES OFFSHORE...BUT
THERE IS ENOUGH UNCERTAINTY TO MAINTAIN SOME SCT -SHSN WORDING OVER
THE NRN PORTION OF THE KEWEENAW OVERNIGHT. AS FOR TEMPS...BASED ON
SATELLITE IMAGERY...IT LOOKS LIKE THERE WILL BE A DECENT PERIOD OF
CLEAR TO PARTLY CLOUDY SKIES TONIGHT OVER MUCH OF THE AREA. WITH
LIGHT WINDS AND PRECIPITABLE WATER 40-55PCT OF NORMAL...FAVORED THE
LOW END OF GUIDANCE. TEMPS SHOULD PLUMMET RAPIDLY THIS EVENING WHERE
SKIES ARE CLEAR...AND EXPECT TRADITIONAL COLD SPOTS TO FALL TO
AROUND -5F. HOWEVER...GIVEN THE SLOW ADVANCE OF UPSTREAM CLOUDS...
CLOUDS MAY BE SLOWER TO ARRIVE THAN CURRENTLY FCST. COMBINED WITH
FRESH SNOW COVER...COULD EASILY SEE TEMPS FALL TO -10F OR LWR IN THE
USUAL COLD SPOTS.
SHORTWAVE CURRENTLY MOVING INTO THE DAKOTAS WILL CONTINUE TO DROP SE
TOWARD THE TENNESSEE VALLEY TONIGHT/WED AND WILL HAVE NO INFLUENCE
HERE AS IT PASSES WELL S OF UPPER MI. OF CONCERN IS THE FOLLOWING
SHORTWAVE TROF WHICH WILL SWING SE AND EXTEND FROM JAMES BAY TO MN
BY 00Z THU. AS HEIGHT FALLS/MODEST DEEP LAYER FORCING PER QVECTORS
OVERSPREAD THE RELATIVELY WARM WATERS OF LAKE SUPERIOR...SFC TROF
MOVING OVER THE LAKE WILL SHARPEN UP...RESULTING IN INCREASING
CONVERGENCE AND INTENSIFYING LAKE ENHANCED SNOW ALONG/NEAR TROF.
EXPECT THIS TROF TO REACH THE KEWEENAW DURING THE MORNING AND THE W
IN THE AFTN. TROF PROBABLY WON`T REACH NCNTRL UPPER MI UNTIL
EVENING. NE ORIENTATION OF THE WINDS ACROSS THE KEWEENAW AFTER
TROF PASSAGE WON`T BE ESPECIALLY FAVORABLE FOR PERSISTENT HEAVIER
LAKE ENHANCED SNOW AFTER THE MAIN MDT/HVY SNOW BAND ALONG TROF
SHIFTS S. FARTHER S...SHARPER LOW-LEVEL CONVERGENCE AND BETTER
UPSLOPING IS EXPECTED INTO ONTONAGON/GOGEBIC COUNTIES...AND THIS IS
INDICATED IN MODEL GUIDANCE IN LOW-LEVEL OMEGA FIELDS. WIND FLOW
SUGGESTS LAKE NIPIGON PRECONDITONING WILL ALSO COME INTO PLAY OVER
THE FAR W. WITH THESE FAVORABLE CONDITIONS CONTINUING INTO THE WED
NIGHT...WILL HOIST A LAKE EFFECT SNOW ADVISORY FOR ONTONAGON/GOGEBIC
STARTING AT 20Z WED. IN GENERAL...A QUICK COUPLE OF INCHES OF SNOW
WILL PROBABLY OCCUR AS THE TROF MOVES ONSHORE OVER THE W.
ELSEWHERE...SOME -SN SHOULD GRADUALLY OVERSPREAD THE REST OF WRN
UPPER MI IN THE AFTN. TO THE E...IT APEARS WINDS WILL BACK
SUFFICIENTLY TO BRING SOME LES OFF LAKE MICHIGAN INTO THE FAR ERN
FCST AREA IN THE AFTN. WINDS ARE LIGHT/CONVERGENCE WEAK...SO NOT
EXPECTING MUCH WITH THE LES OFF LAKE MI WED (LESS THAN 1 INCH).
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 553 AM EST WED NOV 26 2014
MODELS SHOW A FAIRLY PROGRESSIVE ZONAL FLOW PATTERN ACROSS THE NRN
CONUS THROUGH MUCH OF THE EXTENDED PD WITH SERIES OF SHORTWAVES
MOVING THROUGH THE AREA KEEPING WX FAIRLY ACTIVE THROUGH THE HOLIDAY
WEEKEND.
BEGINNING THANKSGIVING INTO THU NGT...MODELS INDICATE THE LLVL FLOW
BACKING STEADILY AND BECOMING MORE ANTICYCLONIC THROUGH THANKSGIVING
DAY WITH SFC HI PRES MOVING TOWARD CENTRAL IL LATE IN THE DAY UNDER
HGT RISES/DNVA IN ADVANCE OF THE APPROACHING SHRTWV RDG FM THE NRN
PLAINS. THE RESULT WL BE SHIFTING/DIMINISHING LES BANDS...ESPECIALLY
OVER THE W HALF. THE SNOW SHOWERS SHOULD END COMPLETELY AT IWD LATE
IN THE AFTN AS FLOW BACKS WSW. THE LES WL BE MORE PERSISTENT IN THE
FAVORED SN BELTS E OF MARQUETTE WITH H85 THERMAL TROF/TEMPS AROUND
-18C MOVING OVER ERN LAKE SUPERIOR LATE IN THE DAY...BUT INCREASING
ANTICYCLONIC FLOW...WEAKENING LOW-LVL CONVERGENCE AND LOWERING OF
INVERSION HGTS TO AROUND 3KFT AS SHOWN ON FCST SDNGS FROM INCREASED
SUBSIDENCE AHEAD OF BUILDING RDG WL LIMIT ADDITIONAL SNOW ACUUMS TO
GENERALLY NO MORE THAN 2-3". THANKSGIVING WL BE QUITE CHILLY
WITH H85 THERMAL TROF PASSING OVERHEAD AND COULD FEATURE SOME RECORD
LOW MAX TEMPS. CERTAINLY RECORD LOW MAX TEMP OF 18F HERE AT NWS MQT
WILL BE IN JEOPARDY AS FCST TEMPS ARE IN THE MID TEENS. EXPECT THE
LOWEST TEMPS OVER THE W HALF WHERE BACKING FLOW WL LIMIT LK SUPERIOR
MODERATION.
AS THE SFC RDG AXIS SHIFTS E ACROSS THE AREA AND THE FLOW BACKS TO
THE W-SW...LINGERING LES OVER ERN COUNTIES WL SHIFT OUT INTO LK
SUPERIOR ON THU NGT. TEMPS COULD FALL QUICKLY IN THE EVENING TOWARD
THE LOWER END OF MODEL GUIDANCE BEFORE MORE HIGH CLDS OVERSPREAD THE
AREA W-E ASSOCIATED WITH DEVELOPING SW FLOW/ISENTROPIC ASCENT IN
ADVANCE OF A SHRTWV STREAKING EWD TOWARD MN. SINCE BOTH THE 00Z GFS
AND NAM SHOW SN ASSOCIATED WITH THIS WAA/SHRTWV REACHING THE FAR W
BY 12Z FRI...WL CONTINUE TO MAINTAIN SOME LOW CHC POPS IN THIS AREA
LATE THU NGT.
FRI/FRI NGT...SW FLOW/ISENTROPIC ASCENT OVER THE UPPER GREAT LAKES
IN ADVANCE OF SHRTWV TRACKING EWD THRU MN IS PROGGED BY MOST OF THE
MODELS TO BRING INCREASING MID LVL MSTR/WIDESPREAD SNOW TO THE FCST
AREA ON FRI NE OF AN H85 WARM FNT STRETCHING FM THE NRN PLAINS INTO
MN AND WI. BEST ISENTROPIC ASCENT ON 280-290K SFCS ALONG WITH MIXR
OF 3 G/KG MAY ALLOW FOR SOME MODERATE SNOW AMOUNTS APPROACHING
ADVISORY CRITERIA OVER THE SCNTRL FCST AREA. WILL ALSO NEED TO
MONITOR LAKE ENHANCED SNOW POTENTIAL OFF LAKE MI OVER THE ERN CWA AS
SOME OF MODELS PARTICULARLY THE ECMWF SHOW LOW-LVL WINDS BECOMING
MORE SRLY IN THE PRESENCE OF H85 TEMPS IN THE -8 TO -10C RANGE...SO
WL MAINTAIN THE HIGHER POPS/QPF IN THIS AREA. ON FRI NGT...THE GFS
AND NAM ARE ON THE QUICKER SIDE OF MODEL GUIDANCE SHOWING A STRONGER
SHRTWV/SFC TROUGH REFLECTION TRACKING FASTER E ACROSS UPPER MI/LK
SUPERIOR ON FRI NGT...ALLOWING FOR A COLDER WRLY FLOW ACROSS THE CWA
FRI NGT. WILL FAVOR WPC PREFERRED SLOWER AND MORE CONSISTENT ECMWF
SOLUTION WHICH SHOWS A SLOWER SFC LOW AND MORE AGGRESSIVE PUSH OF
THE 850 MB WARM FRONT ACROSS THE CWA WITH H85 TEMPS RISING ABOVE 0C
OVER THE WEST AND SCNTRL CWA BY 12Z SAT ACCOMPANIED BY DRY
SLOTTING/LOWERING POPS FM THE SW. WITH ECWMF SNDGS CONTINUING TO
SHOW LINGERING LLVL MSTR BLO THE WARMING/DRYING ARND H85...WILL
CONTINUE TO CARRY MENTION OF FREEZING DZ OVER THE SW CWA.
SAT/SAT NGT...SHRTWV EMBEDDED IN ZONAL FLOW OVER SRN CANADA WL
STREAM E...WITH ACCOMPANYING SFC LOW STREAKING ENE THRU ONTARIO AND
DRAGGING A COLD FRONT ACROSS THE CWA SAT AFTERNOON/SAT NIGHT. AHEAD
OF THIS FRONT... MORE CONSISTENT AND FAVORED 12Z ECMWF/GEM-NH MODEL
SOLNS SHOW WARM SURGE INTO THE UPR LKS WITH H85 TEMPS RISING AS HI
AS 8-10C OVER THE SRN TIER ON SAT UNDER MID LVL DRYING. CONTINUE TO
CARRY ONLY LOW CHC POPS OVER THE SRN TIER...WHERE THE ECMWF AND
GEM-NH MODELS SHOW MORE AGGRESSIVE MID LVL DRYING FARTHER FM THE
LOW TRACK. CONTINUED TO MENTION SOME FREEZING DZ IN THESE AREAS AS
WELL. FARTHER TO THE N CLOSER TO THE LOW TRACK HAVE SOMEWHAT HIER
CHC POPS AND INCLUDED MENTION OF FREEZING RA AND RA IN ADDITION TO
SN IN CASE THE AIRMASS COOLS MORE DUE TO EVAPORATIVE COOLING. KEPT
HIGH TEMPS IN THE LOWER TO MID 30S UNDER EXPECTED LOW CLOUDS. IT
LOOKS LIKE ANY ICE ACCUMULATION WL BE MINOR DUE TO GENERAL DRYNESS
OF AIRMASS.
SUNDAY INTO TUESDAY...ECMWF AND GEM-NH SHOW MUCH COLDER AIR MOVING
IN ON SUNDAY IN THE WAKE OF SAT NIGHT/S FRONT...WITH H85 TEMPS FCST
AS LOW AS -17C WEST BY 00Z MON. EXPECT SOME LK EFFECT TO DEVELOP
SUNDAY OVER THE NW FLOW AREAS BUT SINCE THE UPR FLOW WL REMAIN
FAIRLY PROGRESSIVE...SFC HI PRES FM THE NRN PLAINS WL SHIFT THRU THE
UPPER GREAT LAKES ON MON. THE RESULT SHOULD BE DIMINISHING LES ON
MON WITH DRY AIRMASS LINGERING INTO TUE. WARMER SW FLOW ON THE WRN
FLANK OF DEPARTING SFC HI PRES MAY DRAW ENOUGH MOISTURE N ON TUE
AHEAD OF ANOTHER SHORTWAVE APPROACHING FM THE NRN PLAINS TO BRING A
RETURN OF SOME LIGHT SNOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1256 AM EST WED NOV 26 2014
VFR CONDITIONS WILL CONTINUE AT KIWD/KSAW TONIGHT AND WILL CONTINUE
AT KSAW THROUGH WED. NEXT APPROACHING DISTURBANCE WILL BRING SOME
-SN/MVFR CONDITIONS TO KIWD BY WED AFTERNOON WHICH WILL FALL TO IFR
LATE WED AFTERNOON LASTING INTO THE EVENING. AT KCMX...WINDS MAY
RETAIN ENOUGH OVERWATER COMPONENT TO MAINTAIN MVFR CONDITIONS THRU
MOST OF THE PERIOD. KSAW WILL FALL TO IFR CONDITIONS BY WED EVENING
AS SNOW MOVES IN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 450 PM EST TUE NOV 25 2014
PRES GRADIENT RAPIDLY WEAKENS TONIGHT WITH A WEAK SFC TROF DROPPING
SE OVER LAKE SUPERIOR. THIS WILL RESULT IN WINDS DIMINISHING TO UNDER
20KT ACROSS THE LAKE. STRONG HIGH PRES WILL THEN BUILD SE INTO THE
CANADIAN PRAIRIES WED AND INTO THE NRN PLAINS WED NIGHT. THIS WILL
PUSH THE TROF SE AND TIGHTEN THE PRES GRADIENT. AS A RESULT... WITH
THE TROF PASSAGE...EXPECT NORTHERLY WINDS TO RAMP UP TO 20-30KT FROM
NW TO SE WED/WED NIGHT. NOT OUT OF THE QUESTION THAT THERE COULD BE
SOME GALE FORCE GUSTS OVER THE CNTRL PORTION OF LAKE SUPERIOR. WINDS
WILL THEN DIMINISH TO UNDER 20KT W TO E THU/THU NIGHT AS HIGH PRES
RIDGE ARRIVES. WITH ANOTHER COLD FRONT PUSHING ACROSS THE UPPER LAKES
SAT...EXPECT INCREASING WINDS TO 15-25KT FRI/FRI NIGHT AHEAD OF
FRONT. BEHIND FRONT...NW WINDS MAY REACH 20-30KT LATE SAT/SUN.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
THURSDAY FOR MIZ006.
LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
THURSDAY FOR MIZ004.
LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
THURSDAY FOR MIZ005.
LAKE EFFECT SNOW WARNING FROM 3 PM EST /2 PM CST/ THIS AFTERNOON
TO 1 PM EST /NOON CST/ THURSDAY FOR MIZ002-009.
LAKE EFFECT SNOW ADVISORY FROM 3 PM THIS AFTERNOON TO 7 AM EST
THURSDAY FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...VOSS
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
305 PM MST WED NOV 26 2014
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 305 PM MST WED NOV 26 2014
AN UPPER LEVEL RIDGE OVER THE WESTERN STATES WILL FLATTEN AS IT
SHIFTS EAST OVER THE GREAT BASIN THURSDAY. THIS WILL CAUSE THE
NORTHWEST FLOW ALOFT OVER COLORADO TO BECOME WEST-NORTHWESTERLY
TOMORROW. SOME CLOUDS ARE LINGERING OVER THE MOUNTAINS AND PERHAPS A
FEW FLURRIES TOO. THERE IS ALSO A SLIGHT CHANCE FOR LIGHT SNOW OVER
THE NORTHEAST PLAINS THIS EVENING. THE HRRR SHOWS A SMALL BAND
REFORMING THIS EVENING. NOT SOLD ON THIS...SO WILL STICK TO THE
SLIGHT CHANCE. IF ANY SNOW FORMS...IT SHOULD BE LIGHT.
A SURFACE HIGH PRESSURE OVER THE EASTERN PLAINS AND A
SURFACE TROUGH ALONG THE BASE OF THE FOOTHILLS HAS KEPT THE COOLER
AIR OVER NORTHEAST COLORADO TODAY. THE LEE SIDE TROUGH ALONG WITH
HIGHER PRESSURE OVER THE GREAT BASIN HAS PRODUCED WINDY CONDITIONS
IN THE MOUNTAINS AND FOOTHILLS. TEMPERATURES HAVE WARMED NICELY IN
THE LOWER FOOTHILLS WITH READINGS IN THE UPPER 40S. AS HIGH PRESSURE
SHIFTS EAST OF THE REGION AND A SURFACE TROUGH DEEPENS OVER THE
NORTHERN ROCKIES...SOUTH TO SOUTHWEST WINDS WILL FLUSH OUT THE
COOLER AIR OVER NORTHEAST COLORADO AND LEAD TO MILD TEMPERATURES FOR
THANKSGIVING. THERE WILL STILL BE SOME MOISTURE AT THE MID AND UPPER
LEVELS...SO WAVE CLOUDS ARE EXPECTED AT TIMES. THIS MAY SLOW WARMING
SOME...BUT STILL LOOKS LIKE HIGHS WILL CLIMB ABOVE 60 DEGREES ACROSS
NORTHEAST COLORADO. WINDS WILL BE GUSTY IN THE FOOTHILLS AND
MOUNTAINS AGAIN WITH GUSTS TO 50 TO 60 MPH IN THE WIND PRONE AREAS
OF THE MOUNTAINS AND FOOTHILLS.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 PM MST WED NOV 26 2014
...A DRY AND WARM PATTERN IS SETTING UP FOR FRIDAY THROUGH
SUNDAY...
STARTING WITH FRIDAY A DRY AIRMASS WILL BE IN PLACE WITH STRONG
WNW FLOW ALOFT. ACCORDING TO MODEL CROSS-SECTIONS A MOUNTAIN WAVE
WILL FORM THURSDAY EVENING INTO EARLY FRIDAY. SUSTAINED WINDS OF
40 TO 45 MPH WITH GUSTS UP TO 70 WILL BE POSSIBLE OVER THE HIGHER
MOUNTAIN PEAKS. THERE IS A LACK OF AN INVERSION LAYER AT MOUNTAIN
TOP SO IT WILL DIFFICULT TO BRING THOSE WINDS DOWN TO THE SURFACE
SO HIGHER WINDS SHOULD REMAIN WITHIN THE MOUNTAINS.
HOWEVER...CHINOOK WARMING WILL OCCUR ON FRIDAY AND AID IN GETTING
AREAS CLOSE TO THE FOOTHILLS WELL ABOVE SEASONAL NORMALS. CURRENT
TRENDS HAVE HIGHS IN THE LOWER 70S FOR THE DENVER METRO. THIS
WOULD EITHER MEET OR EXCEED THE CURRENT RECORD HIGH FOR FRIDAY OF
72 SET BACK IN 1901.
DRY PATTERN CONTINUES INTO SATURDAY AND EARLY SUNDAY WITH
WESTERLY FLOW BECOMING MORE DOMINANT. WINDS OVER THE MOUNTAINS
WILL CONTINUE WITH GUSTING TO 70 MPH STILL POSSIBLE OVER MOUNTAIN
TOP. MOUNTAIN TOP STABILITY IS STILL LACKING SO WILL KEEP WINDS
ISOLATED TO THE MOUNTAINS FOR THE TIME BEING. TEMPERATURES WILL
CONTINUE TO BE WELL ABOVE SEASONAL NORMALS WITH HIGHS ON SATURDAY
IN THE UPPER 60S.
FOR SUNDAY...MODELS STILL INDICATING A STRONG MOUNTAIN WAVE IN THE
MORNING WITH WINDS CONTINUING TO GUST TO 60-65 OVER MOUNTAIN
PEAKS. THE MAIN FEATURE HOWEVER FOR THIS TIMEFRAME IS AN ELONGATED
UPPER LEVEL TROF MOVING THROUGH THE REGION BRINGING A BACKDOOR
COLD FRONT INTO THE EASTERN PORTIONS OF THE STATE. THIS WILL BRING
HIGH TEMPERATURES DOWN SIGNIFICANTLY WITH THE PLAINS STRUGGLING
TO GET OUT OF THE 40S. MOISTURE STILL LACKING WITH THIS SYSTEM SO
LEFT POPS OUT.
FOR MONDAY AND TUESDAY...MODELS ARE STILL IN DISAGREEMENT WITH THE
TIMING OF THE SYNOPTIC FEATURES FOR THE NEXT SYSTEM. THE GFS SHOWS
WESTERLY FLOW WITH INCREASING MOISTURE AHEAD OF THE FRONT WITH
LITTLE PRECIP ASSOCIATED...WHILE THE EC HAS A MORE NORTHWEST FLOW
WITH RAIN MOVING INTO THE WESTERN PORTIONS OF THE STATE BY MONDAY
MORNING. WILL KEEP CURRENT POPS WITH NO CHANGES FOR THIS PERIOD.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 305 PM MST WED NOV 26 2014
VFR CONDITIONS WILL PREVAIL THE NEXT 24 HOURS WITH MID AND HIGH
CLOUDS AT TIMES. NORTHEAST WINDS ARE EXPECTED TO TURN SOUTHEASTERLY
JUST AFTER 00Z AT KDEN AND THEN BECOME SOUTHERLY BY 03Z. SOUTH TO
SOUTHWEST WINDS ARE THEN EXPECTED TO PREVAIL THE REST OF TONIGHT AND
THURSDAY THROUGH OUT THE DENVER AREA. WIND SPEEDS SHOULD REMAIN LESS
THAN 20 KNOTS TONIGHT AND THURSDAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MEIER
LONG TERM...BOWEN
AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
923 AM MST WED NOV 26 2014
.UPDATE...
ISSUED AT 923 AM MST WED NOV 26 2014
RADAR SHOWING A BAND SNOW STILL HANGING ON OVER THE NORTHEAST
CORNER OF THE STATE. RAISED POPS FOR THIS THROUGH THE MORNING
WHERE UP TO AN ADDITIONAL INCH OF SNOW WILL BE POSSIBLE. INCREASED
WINDS ALONG HIGHWAY 285 ACROSS PARK COUNTY FOR TODAY. OBSERVATIONS
SHOWING GUSTS T0 60 MPH HERE...THE RAP AND HRRR SHOW THESE STRONG
WINDS CONTINUING THROUGH MID AFTERNOON. INCREASED THE FORECAST TO
INDICATE GUSTS TO 70 MPH WILL BE POSSIBLE.
PLAN ON LETTING THE WINTER WEATHER ADVISORY EXPIRE AT NOON. WEB
CAMERAS JUST SHOWING LIGHT SNOW IN PLACES. IN GENERAL...CONDITIONS
ARE STARTING IMPROVE IN THE HIGH COUNTRY...THOUGH MANY ROADS ARE
STILL SNOW COVERED.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 222 AM MST WED NOV 26 2014
NW FLOW ALOFT WILL CONTINUE OVER THE AREA TODAY. CROSS-SECTIONS
STILL SHOW ENOUGH MOISTURE IN THE MTNS COMBINED WITH MARGINAL LAPSES
WHICH WILL LEAD TO ADDITIONAL SNOWFALL THRU THE MORNING HOURS BEFORE
DIMINISHING IN THE AFTN AS DRIER AIR BEGINS TO ADVECT IN. MEANWHILE
GUSTY NW WINDS WILL CONTINUE AS WELL SO EXPECT BLOWING SNOW MAINLY
ABOVE 10000 FT THUS WILL EXTEND ADVISORY THRU NOON.
AT LOWER ELEVATIONS NERN CO REMAINS ON THE BACKSIDE OF AN UPPER
LEVEL JET WHICH WILL ALLOW FOR SOME ADDITIONAL BANDED PCPN THRU
THE MORNING HOURS ACROSS THE PLAINS. MOST OF THE ACTIVITY WILL
FOCUS ENE OF A GREELEY TO LIMON LINE. WEAK UPSLOPE ALONG THE FRONT
RANGE MAY LEAD TO SOME VERY LIGHT SNOW/FLURRIES AS WELL THRU MID
MORNING. BY MIDDAY SHOULD PCPN CHANCES END OVER THE PLAINS. AS FOR
HIGHS THERE COULD BE QUITE A RANGE OVER NERN CO WITH READINGS IN
THE LOWER 50S AROUND DENVER WHILE FURTHER NE OVER THE PLAINS HIGHS
STAY IN THE 30S.
FOR TONIGHT OUTSIDE OF A FEW -SHSN IN THE MTNS THIS EVENING IT
SHOULD BE DRY. A MTN WAVE WILL DEVELOP OVERNIGHT WITH CROSS-MTN
FLOW IN THE 40-45 KT RANGE. THUS WILL SEE GUSTY WINDS IN THE HIGHER
MTNS AND FOOTHILL AREAS BUT SPEEDS SHOULD STAY BLO HIGH WIND
CRITERIA.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 222 AM MST WED NOV 26 2014
A DRYING AND WARMING TREND WILL BE THE MAIN FEATURES FROM THURSDAY
THROUGH SATURDAY AS TEMPERATURES CLIMB ABOVE NORMAL FOR THIS TIME
OF YEAR. FOR THURSDAY...A DRYING AIRMASS WILL BE IN PLACE AS THE
FLOW ALOFT REMAINS FROM THE NORTHWEST WITH DOWNSLOPE FLOW. CROSS
SECTIONS SHOW STRONG WEST TO NORTHWEST FLOW INCREASING AT MOUNTAIN
TOP THROUGH THE DAY BUT WITH LACK OF MOUNTAIN TOP STABILITY
EXPECT MUCH OF THE HIGHER WINDS TO BE CONFINED TO THE MOUNTAINS
PASSES AND HIGHER EAST SLOPES WITH GUSTS UP TO 70 MPH POSSIBLE.
FOR FRIDAY AND SATURDAY...THE FLOW ALOFT BECOMES MORE WESTERLY
UNDER A VERY DRY AIRMASS. THERE WILL BE CONTINUED GUSTY WINDS OVER
THE MOUNTAINS AND HIGHER EAST SLOPES WITH GUSTS UP TO 70 MPH BUT
AGAIN HIGHER WINDS WILL BE MORE CONFINED TO HIGHER AREAS.
TEMPERATURES WILL CONTINUE TO WARM OVER LOWER ELEVATIONS WITH
READINGS FLIRTING INTO THE UPPER 60S AND LOWER 70S AND POSSIBLE
RECORD HIGHS IF WE GET ENOUGH LOW LEVEL MIXING AND DOWNSLOPE FLOW.
SIMILAR CONDITIONS EXPECTED FOR SATURDAY UNDER STRONG WESTERLY
FLOW ALOFT AND CONTINUED ABOVE NORMAL TEMPERATURES FOR THIS TIME
OF YEAR.
FOR SUNDAY...AN UPPER TROF SWEEPS ACROSS THE NORTHERN HIGH PLAINS
WHICH SENDS AN ASSOCIATED COLD FRONT INTO NORTHEAST COLORADO LATE
IN THE DAY. THE RESULT WILL BE COOLER TEMPERATURES BUT STILL
LOOKS TOO DRY FOR ANY PRECIP.
BY LATE MONDAY AND TUESDAY...LONG RANGE MODELS ARE IN CONSIDERABLE
DISAGREEMENT WITH THE LARGE SCALE FEATURES. THE GFS SHOWS
INCREASING MOISTURE AHEAD OF A PACIFIC DISTURBANCE. ON THE OTHER
HAND THE EUROPEAN HAS A NORTHWEST FLOW PATTERN WITH SOME EMBEDDED
SHOWERS. FOR NOW WILL MAINTAIN JUST A SLIGHT CHANCE OF SNOW
SHOWERS IN THE MOUNTAINS ON TUESDAY.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z THURSDAY MORNING)
ISSUED AT 923 AM MST WED NOV 26 2014
SNOW WILL COME TO AN END TODAY OVER THE MOUNTAINS AND NORTHEAST
PLAINS...WHILE THE DENVER AREA IS EXPECTED TO REMAIN SNOW FREE
TODAY. THE LOW CLOUDS WILL CONTINUE TO BURN OFF IN THE DENVER
AREA...AND EXPECTED VFR CONDITIONS THROUGH OUT THE DENVER AREA BY
18Z. WINDS WILL REMAIN ON THE LIGHT SIDE...TODAY AND TONIGHT. WIND
DIRECTION WILL BE EASTERLY TODAY AND THEN TURN SOUTHERLY AFTER
00Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR COZ031-033-034.
&&
$$
UPDATE...MEIER
SHORT TERM...RPK
LONG TERM...ENTREKIN
AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
123 PM MST WED NOV 26 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 123 PM MST WED NOV 26 2014
AS OF 2 PM CST...1 PM MST...SKIES ACROSS THE TRI-STATE REGION VARIED
FROM MOSTLY CLEAR TO OVERCAST. TEMPERATURES WERE IN THE 40S WHERE
CLOUDS HAVE BROKEN UP AND IN THE LOW TO UPPER 30S WHERE PERSISTENT
CLOUDS REMAIN. WINDS WERE FROM THE NORTH AT 10 TO 15 MPH AND ON A
GRADUAL WEAKENING TREND. WSR-88D RADAR DATA HAS NOTED A DOWNWARD
TREND IN RADAR REFLECTIVITIES AS THE BAND OF LIGHT SNOW SHOWERS
FINALLY BEGINS TO DIMINISH. SNOW APPEARS TO BE THE RESULT OF LOW
LEVEL FRONTOGENESIS OVER NORTHEAST COLORADO AS NO MAJOR DISTURBANCES
HAVE BEEN OBSERVED BY WATER VAPOR IMAGERY.
FOR THE REST OF THE AFTERNOON AND TONIGHT...MAIN FORECAST CONCERN IS
DECREASING SNOW SHOWER ACTIVITY THROUGH THE AFTERNOON WITH POSSIBLE
BRIEF REDEVELOPMENT THIS EVENING. LATEST RAP GUIDANCE/HRRR GUIDANCE
SEEMS TO BE HANDLING THIS SITUATION BEST SO HAVE LEANED ON THESE
SOLUTIONS. RAP FORECAST SOUNDINGS INDICATE THAT THE ICE CRYSTAL
GROWTH ZONE LOSES SATURATION THIS AFTERNOON...LEADING TO A DECREASE
IN PRECIPITATION. THAT TREND IS ALREADY BEING REALIZED. RAP
SOUNDINGS THEN INDICATE ONE MORE PUSH OF MOISTURE IN THE ICE CRYSTAL
GROWTH ZONE LATER THIS EVENING BEFORE THE ENTIRE ATMOSPHERIC PROFILE
DESATURATES. ATTEMPTED TO SHOW THIS UP AND DOWN TREND WITH THE POPS
THROUGH THIS EVENING AND THEN FORECAST DRY WEATHER AFTER MIDNIGHT.
SKIES GRADUALLY CLEAR LATE TONIGHT WITH A QUICK DROP IN TEMPS ONCE
CONDITIONS ARE CONDUCIVE FOR RADIATIONAL COOLING.
FOR THANKSGIVING DAY...OVERALL CALM WEATHER IS ANTICIPATED WITH NO
PRECIPITATION EXPECTED. ATMOSPHERIC PROFILE BECOMES QUITE DRY BY
AFTERNOON...ESPECIALLY IN THE LOW LEVELS...AS DRY AIR ADVECTION
CONTINUES FROM THE SOUTHWEST. A LEE TROUGH DEEPENING OVER CENTRAL
COLORADO SHALL LEAD TO PERSISTENT SOUTHWEST FLOW THROUGHOUT THE DAY.
WARM 850 MB TEMPS ALSO ADVECT IN SO EXPECTING A WARM...ABOVE NORMAL
DAY. ONE THING THAT IS INTERESTING ABOUT TOMORROW IS FORECAST
SOUNDINGS INDICATE THAT A PERSISTENT INVERSION NEAR THE SURFACE MAY
PREVENT SOME STRONGER WIND GUSTS ALOFT FROM BEING REALIZED AT THE
SURFACE. WILL NEED TO WATCH THIS CAREFULLY AS LOW RELATIVE HUMIDITY
WILL BE PRESENT OVER CHEYENNE AND KIT CARSON COUNTIES IN COLORADO
AND SHERMAN...WALLACE...GREELEY AND POSSIBLY WICHITA COUNTIES IN
KANSAS. OVERALL...KEPT FORECAST WINDS LIGHT BUT NERVOUS ABOUT
STRONGER WINDS ALOFT MIXING DOWN. IF WINDS ARE REALIZED...A FIRE
WEATHER HIGHLIGHT MAY BE REQUIRED.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 1204 PM MST WED NOV 26 2014
BROAD ZONAL FLOW WILL PERSIST THROUGH SATURDAY ACROSS THE CENTRAL
CONUS OVER A LOW AMPLITUDE RIDGE CENTERED OVER THE DESERT
SOUTHWEST. THIS WILL RESULT IN DRY CONDITIONS AND MUCH ABOVE
NORMAL TEMPERATURES. RELATIVE HUMIDITY WILL DROP TO NEAR CRITICAL
FIRE WEATHER VALUES EACH AFTERNOON...HOWEVER WIND FORECASTS ARE
RELATIVELY LIGHT AND NO FIRE WEATHER HIGHLIGHTS ARE ANTICIPATED. A
NORTHERN STREAM SHORTWAVE WILL SUPPORT A SURFACE COLD FRONT WHICH
WILL MOVE THROUGH THE CENTRAL HIGH PLAINS SATURDAY NIGHT. SYNOPTIC
SCALE FORCING FOR PRECIPITATION WILL REMAIN NORTH OF THE LOCAL
AREA AND FROPA WILL LIKELY BE DRY. TEMPERATURES ON SUNDAY WILL BE
CLOSER TO NORMAL...THEN COOL TO BELOW NORMAL ON MONDAY WHICH WILL
BE THE COLDEST DAY OF THIS PERIOD. TEMPERATURES BOUNCE BACK TO
ABOVE NORMAL ON TUESDAY UNDER SHORTWAVE RIDGING WITH CONTINUED DRY
CONDITIONS. FINALLY...ON WEDNESDAY A SHORTWAVE TROUGH IN THE
SOUTHERN STREAM WILL MOVE OUT OF THE SOUTHERN ROCKIES AND EMERGE
ONTO THE ADJACENT PLAINS...WITH A CHANCE FOR RAIN AND SNOW. TIMING
AND AMOUNTS WITH THE SYSTEM STILL VERY UNCERTAIN WITH SIGNIFICANT
MODEL DIFFERENCES AT THIS TIME RANGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1028 AM MST WED NOV 26 2014
BAND OF MVFR CLOUDS WITH SOME SNOW IS MOVING TOWARDS KGLD AT
1700Z. MVFR STRATUS HAS REACHED TAF SITE BUT NOT EXPECTING ANY
VISIBILITY RESTRICTIONS FROM SNOW. CEILINGS AT KGLD SHOULD IMPROVE
BY 2100Z. CLOUD DECK AROUND 5000 FT REACHES KMCK THIS AFTERNOON
WITH NO SNOW ANTICIPATED. NORTHWEST WINDS WEAKEN TODAY AND AFTER A
PERIOD OF LIGHT/VARIABLE THIS EVENING...WINDS BECOME SOUTHWEST AT
KGLD AND SOUTH AT KMCK AS A LEE TROUGH DEVELOPS TO THE WEST. SOUTH
WINDS INCREASE IN SPEED AFTER SUNRISE TOMORROW UNDER MOSTLY CLEAR
SKIES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...RRH
LONG TERM...024
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1215 PM MST WED NOV 26 2014
.UPDATE...
ISSUED AT 1028 AM MST WED NOV 26 2014
LIGHT SNOW CONTINUES TO SPREAD IN FROM THE NORTHWEST. BASED ON AN
ANALYSIS OF FORECAST RAP SOUNDINGS...SNOW MAY CONTINUE INTO THE
EARLY AFTERNOON HOURS BEFORE A LAYER OF DRY AIR BEGINS TO MOVE
INTO THE ICE CRYSTAL GROWTH ZONE. UPDATED THE FORECAST TO REFLECT
CURRENT TRENDS BY INCREASING CHANCES OF PRECIP AND MAKING
ADJUSTMENTS TO QPF/SNOW GRIDS. EARLIER HAZARDOUS CONDITIONS WITH
ICY ROADS SHOULD NO LONGER BE AN ISSUE AS SOME SUN HAS REACHED THE
GROUND AND TEMPERATURES A FEW DEGREES HIGHER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 235 AM MST WED NOV 26 2014
LATEST UPPER AIR ANALYSIS INDICATES A TROUGH OF LOW PRESSURE OVER
EASTERN SOUTH DAKOTA. SATELLITE AND RADAR SHOW A BAND OF CLOUDS
WITH SOME LIGHT SNOW OVER THE TRI-STATE AREA. MOST OF THE SNOWFALL
IS OVER EASTERN COLORADO. AS SUNRISE APPROACHES ANTICIPATE THE
SNOWFALL TO DISSIPATE TOWARD THE WEST AS THE UPPER LEVEL TROUGH
AXIS MOVES THROUGH THE AREA WITH SUBSIDENCE FOLLOWING THE TROUGH
AXIS. SNOWFALL SHOULD BE COMPLETELY WEST OF THE AREA BY OR SHORTLY
AFTER SUNRISE.
TODAY THE OVERCAST SKIES WILL GRADUALLY BREAKUP AS DRIER AIR MOVES
IN FROM THE NORTHWEST. THERE IS SOME WEAK ISENTROPIC LIFT OVER THE
AREA TODAY BUT CONDENSATION PRESSURE DEFICITS ARE GENERALLY TOO
LARGE FOR ANY PRECIP. TO BE GENERATED FROM THE MEAGER LIFT SO WILL
CONTINUE WITH A DRY FORECAST FOR THE DAY. NORTHWEST WINDS WILL
DECLINE FROM WEST TO EAST TODAY AS A SURFACE HIGH PRESSURE MOVES
INTO THE AREA. MODELS CONTINUE TO TREND SLOWER WITH THE WARM AIR
ADVECTION THAT FOLLOWS THE HIGH PRESSURE INTO THE AREA...SO HAVE
COOLED HIGHS TODAY AS A RESULT.
TONIGHT SKIES WILL BECOME MOSTLY CLEAR AS DRY AIR CONTINUES TO MOVE
OVER THE AREA IN THE NORTHWEST UPPER LEVEL FLOW. LOWS WILL BE
COOLER THAN LAST NIGHT DESPITE THE WARM AIR ADVECTION DUE TO
RADIATIONAL COOLING AND LOWER DEW POINTS THAN LAST NIGHT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 1204 PM MST WED NOV 26 2014
BROAD ZONAL FLOW WILL PERSIST THROUGH SATURDAY ACROSS THE CENTRAL
CONUS OVER A LOW AMPLITUDE RIDGE CENTERED OVER THE DESERT
SOUTHWEST. THIS WILL RESULT IN DRY CONDITIONS AND MUCH ABOVE
NORMAL TEMPERATURES. RELATIVE HUMIDITY WILL DROP TO NEAR CRITICAL
FIRE WEATHER VALUES EACH AFTERNOON...HOWEVER WIND FORECASTS ARE
RELATIVELY LIGHT AND NO FIRE WEATHER HIGHLIGHTS ARE ANTICIPATED. A
NORTHERN STREAM SHORTWAVE WILL SUPPORT A SURFACE COLD FRONT WHICH
WILL MOVE THROUGH THE CENTRAL HIGH PLAINS SATURDAY NIGHT. SYNOPTIC
SCALE FORCING FOR PRECIPITATION WILL REMAIN NORTH OF THE LOCAL
AREA AND FROPA WILL LIKELY BE DRY. TEMPERATURES ON SUNDAY WILL BE
CLOSER TO NORMAL...THEN COOL TO BELOW NORMAL ON MONDAY WHICH WILL
BE THE COLDEST DAY OF THIS PERIOD. TEMPERATURES BOUNCE BACK TO
ABOVE NORMAL ON TUESDAY UNDER SHORTWAVE RIDGING WITH CONTINUED DRY
CONDITIONS. FINALLY...ON WEDNESDAY A SHORTWAVE TROUGH IN THE
SOUTHERN STREAM WILL MOVE OUT OF THE SOUTHERN ROCKIES AND EMERGE
ONTO THE ADJACENT PLAINS...WITH A CHANCE FOR RAIN AND SNOW. TIMING
AND AMOUNTS WITH THE SYSTEM STILL VERY UNCERTAIN WITH SIGNIFICANT
MODEL DIFFERENCES AT THIS TIME RANGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1028 AM MST WED NOV 26 2014
BAND OF MVFR CLOUDS WITH SOME SNOW IS MOVING TOWARDS KGLD AT
1700Z. MVFR STRATUS HAS REACHED TAF SITE BUT NOT EXPECTING ANY
VISIBILITY RESTRICTIONS FROM SNOW. CEILINGS AT KGLD SHOULD IMPROVE
BY 2100Z. CLOUD DECK AROUND 5000 FT REACHES KMCK THIS AFTERNOON
WITH NO SNOW ANTICIPATED. NORTHWEST WINDS WEAKEN TODAY AND AFTER A
PERIOD OF LIGHT/VARIABLE THIS EVENING...WINDS BECOME SOUTHWEST AT
KGLD AND SOUTH AT KMCK AS A LEE TROUGH DEVELOPS TO THE WEST. SOUTH
WINDS INCREASE IN SPEED AFTER SUNRISE TOMORROW UNDER MOSTLY CLEAR
SKIES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...RRH
SHORT TERM...JTL
LONG TERM...024
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1028 AM MST WED NOV 26 2014
.UPDATE...
ISSUED AT 1028 AM MST WED NOV 26 2014
LIGHT SNOW CONTINUES TO SPREAD IN FROM THE NORTHWEST. BASED ON AN
ANALYSIS OF FORECAST RAP SOUNDINGS...SNOW MAY CONTINUE INTO THE
EARLY AFTERNOON HOURS BEFORE A LAYER OF DRY AIR BEGINS TO MOVE
INTO THE ICE CRYSTAL GROWTH ZONE. UPDATED THE FORECAST TO REFLECT
CURRENT TRENDS BY INCREASING CHANCES OF PRECIP AND MAKING
ADJUSTMENTS TO QPF/SNOW GRIDS. EARLIER HAZARDOUS CONDITIONS WITH
ICY ROADS SHOULD NO LONGER BE AN ISSUE AS SOME SUN HAS REACHED THE
GROUND AND TEMPERATURES A FEW DEGREES HIGHER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 235 AM MST WED NOV 26 2014
LATEST UPPER AIR ANALYSIS INDICATES A TROUGH OF LOW PRESSURE OVER
EASTERN SOUTH DAKOTA. SATELLITE AND RADAR SHOW A BAND OF CLOUDS
WITH SOME LIGHT SNOW OVER THE TRI-STATE AREA. MOST OF THE SNOWFALL
IS OVER EASTERN COLORADO. AS SUNRISE APPROACHES ANTICIPATE THE
SNOWFALL TO DISSIPATE TOWARD THE WEST AS THE UPPER LEVEL TROUGH
AXIS MOVES THROUGH THE AREA WITH SUBSIDENCE FOLLOWING THE TROUGH
AXIS. SNOWFALL SHOULD BE COMPLETELY WEST OF THE AREA BY OR SHORTLY
AFTER SUNRISE.
TODAY THE OVERCAST SKIES WILL GRADUALLY BREAKUP AS DRIER AIR MOVES
IN FROM THE NORTHWEST. THERE IS SOME WEAK ISENTROPIC LIFT OVER THE
AREA TODAY BUT CONDENSATION PRESSURE DEFICITS ARE GENERALLY TOO
LARGE FOR ANY PRECIP. TO BE GENERATED FROM THE MEAGER LIFT SO WILL
CONTINUE WITH A DRY FORECAST FOR THE DAY. NORTHWEST WINDS WILL
DECLINE FROM WEST TO EAST TODAY AS A SURFACE HIGH PRESSURE MOVES
INTO THE AREA. MODELS CONTINUE TO TREND SLOWER WITH THE WARM AIR
ADVECTION THAT FOLLOWS THE HIGH PRESSURE INTO THE AREA...SO HAVE
COOLED HIGHS TODAY AS A RESULT.
TONIGHT SKIES WILL BECOME MOSTLY CLEAR AS DRY AIR CONTINUES TO MOVE
OVER THE AREA IN THE NORTHWEST UPPER LEVEL FLOW. LOWS WILL BE
COOLER THAN LAST NIGHT DESPITE THE WARM AIR ADVECTION DUE TO
RADIATIONAL COOLING AND LOWER DEW POINTS THAN LAST NIGHT.
.LONG TERM...(THANKSGIVING DAY THROUGH TUESDAY) ISSUED AT 235 AM
MST WED NOV 26 2014
THANKSGIVING DAY THROUGH FRIDAY WILL CONTINUE TO SEE A WARMING TREND
WITH TEMPERATURES RANGING FROM 10 TO 20 DEGREES ABOVE NORMAL. THE
UPPER LEVEL FLOW WILL TRANSITION FROM THE NORTHWEST TO THE WEST.
THERE WILL BE MULTIPLE UPPER LEVEL SHORT WAVE TROUGHS MOVING OVER
THE AREA...BUT DUE TO THE DRY ENVIRONMENT IN PLACE DO NOT EXPECT
MORE THAN A FEW CLOUDS WITH EACH TROUGH PASSAGE.
ZONAL FLOW WILL CONTINUE SATURDAY AND SUNDAY. A RIDGE WILL MOVE
INTO THE ROCKIES SUNDAY NIGHT AND INTO THE PLAINS MONDAY. THE RIDGE
WILL SHIFT EAST TUESDAY WITH FLOW BECOMING SOUTHWESTERLY AHEAD OF A
TROUGH MOVING INTO THE WESTERN CONUS. A SURFACE TROUGH WILL RESIDE
OVER EASTERN COLORADO SATURDAY AND THEN SHIFT EAST SUNDAY AS A COLD
FRONT MOVES SOUTH INTO THE CENTRAL PLAINS. HIGH PRESSURE WILL BUILD
INTO THE CENTRAL PLAINS MONDAY AND TUESDAY. THE WEATHER WILL REMAIN
DRY AND MILD THROUGH THIS PERIOD SINCE THE RIDGE WILL SHUNT STORMS
ACROSS THE NORTHERN CONUS.
850MB TEMPERATURES WILL BE WARM ENOUGH TO SUPPORT MAX TEMPERATURES IN
THE MID TO UPPER 60S SATURDAY. MAX TEMPERATURES SUNDAY AND MONDAY
WILL BE COOLER BEHIND THE FRONT WITH READINGS IN THE 40S.
TEMPERATURES SHOULD WARMUP TO THE UPPER 50S TUESDAY. MIN
TEMPERATURES SATURDAY NIGHT WILL COOL TO THE UPPER 20S. TEMPERATURES
SUNDAY AND MONDAY NIGHTS WILL FALL INTO THE TEENS AND LOW 20S
RESPECTIVELY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1028 AM MST WED NOV 26 2014
BAND OF MVFR CLOUDS WITH SOME SNOW IS MOVING TOWARDS KGLD AT
1700Z. MVFR STRATUS HAS REACHED TAF SITE BUT NOT EXPECTING ANY
VISIBILITY RESTRICTIONS FROM SNOW. CEILINGS AT KGLD SHOULD IMPROVE
BY 2100Z. CLOUD DECK AROUND 5000 FT REACHES KMCK THIS AFTERNOON
WITH NO SNOW ANTICIPATED. NORTHWEST WINDS WEAKEN TODAY AND AFTER A
PERIOD OF LIGHT/VARIABLE THIS EVENING...WINDS BECOME SOUTHWEST AT
KGLD AND SOUTH AT KMCK AS A LEE TROUGH DEVELOPS TO THE WEST. SOUTH
WINDS INCREASE IN SPEED AFTER SUNRISE TOMORROW UNDER MOSTLY CLEAR
SKIES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...RRH
SHORT TERM...JTL
LONG TERM...FS/JTL
AVIATION...RRH
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
315 PM EST WED NOV 26 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 315 PM EST WED NOV 26 2014
...SOME SLUSHY SNOW ACCUMULATIONS POSSIBLE LATE TONIGHT OVER SOUTHERN
PARTS OF EAST KENTUCKY...
19Z SFC ANALYSIS SHOWS EAST KENTUCKY IN BETWEEN TWO AREAS OF LOW
PRESSURE. TO THE EAST...A COASTAL LOW IS NOW PASSING NORTH OF CAPE
HATTERAS...WHILE A MORE MODERATE STRENGTH SFC LOW IS LOCATED OVER
CENTRAL MISSOURI ON ITS PATH SOUTHEAST INTO THE TENNESSEE VALLEY. IN
THE GAP BETWEEN THESE SYSTEMS ENOUGH CLEARING TOOK PLACE FOR MOST OF
THE AREA THAT TEMPERATURES CLIMBED INTO UPPER 40S AND LOWER 50S THIS
AFTERNOON. WINDS ARE GENERALLY LIGHT WHILE DEWPOINTS ARE FOUND IN THE
MID AND UPPER 20S...THOUGH WITH SOME 30S IN THE FAR EAST.
THE MODELS ARE IN PRETTY GOOD AGREEMENT...NOW THAT THE GFS IS
BREAKING TOWARD THE ECMWF AND NAM...ALOFT WITH THE CLIPPER SYSTEM
DROPPING INTO THE TENNESSEE VALLEY TONIGHT. THEY ALL SHOW THE
ENERGY...ASSOCIATED WITH EASTERN PORTION OF THE LARGE TROUGH IN
PLACE OVER THE OHIO VALLEY...LIFTING NORTHEAST INTO EASTERN NEW
ENGLAND BY THURSDAY MORNING. AT THE SAME TIME...A SECONDARY BATCH OF
ENERGY WITHIN THE LARGER TROUGH WILL RIDE SOUTHEAST FROM THE EAST
CENTRAL PLAINS TO THE TENNESSEE VALLEY...THOUGH SHEARING AS IT PASSES
BY KENTUCKY TO THE SOUTH TONIGHT. FOLLOWING THIS...THE WHOLE TROUGH
BODILY MOVES OUT OF THE REGION AND RISING HEIGHTS FOLLOW. HAVE
FOLLOWED A GENERAL MODEL BLEND FOR THE SHORT TERM PORTION THE
FORECAST WITH SOME CAUTIOUS FAVORING OF THE HIGHER RESOLUTION NAM12
AND HRRR FOR WX DETAILS.
SENSIBLE WEATHER WILL FEATURE A QUIET EVENING AS HIGH CLOUDS OVERTAKE
THE SKY AND LOWER WITH TIME. A WEAKENING AREA OF LOW PRESSURE WILL
SLIDE SOUTH THROUGH SOUTHERN KENTUCKY AND INTO EASTERN TENNESSEE.
THIS WILL BRING WITH IT A NARROW BAND OF PCPN CAPABLE OF BECOMING
SNOW GIVEN THE EXPECTED WETBULB EFFECT WHEN IT STARTS COMING DOWN
MODERATELY ACROSS OUR SOUTHERN COUNTIES. HOWEVER...SFC TEMPERATURES
WILL BE NEAR 32 DEGREES AT THEIR COLDEST LIKELY PREVENTING MUCH
ACCUMULATION ON ANYTHING MORE THAN GRASSY AND ELEVATED SURFACES AND
THEN MAINLY ON THE RIDGES AS THE VALLEYS REMAIN A MIX OF RAIN AND
SNOW. THIS IS A DISTURBINGLY SIMILAR SITUATION AS COMPARED TO LAST
NIGHT IN THE EAST WHERE THE HEAVIER PCPN STAYED JUST OFF TO THE EAST.
THESE SMALL SCALE DETAILS MAKE ALL THE DIFFERENCE IN MARGINAL
SITUATIONS AS THIS. HOWEVER...CANNOT RULE OUT A HEAVIER BURST OR TWO
OF SNOW THAT COULD CAUSE A SLUSHY ACCUMULATION ON THE ROADS. THIS
SHOULD NOT LAST LONG...THOUGH...AS ROAD TEMPERATURES ARE CURRENTLY IN
THE 40S AND 50S AND WILL ONLY SLOWLY FALL WITH THE PCPN TONIGHT. HAVE
ISSUED AN SPS TO DEAL WITH THE POTENTIAL FOR A SLUSHY INCH OF SNOW
THAT SHOULD HAVE A MINIMAL IMPACT ON TRAVELERS TONIGHT. THE LIGHT
SNOW/RAIN PULLS OUT OF THE AREA EARLY THURSDAY WITH COOLER
TEMPERATURES TO FOLLOW AS HIGH PRESSURE MOVES THROUGH THE SOUTHERN
APPALACHIANS INTO FRIDAY MORNING.
ONCE AGAIN USED THE BCCONSSHORT AS A STARTING POINT FOR T/TD/WINDS
THROUGH THE NEXT 24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE
SOME TERRAIN BASED ADJUSTMENTS TONIGHT INTO THURSDAY MAINLY TO LOWER
THE RIDGES IN OUR SOUTHERN COUNTIES DUE TO THE PCPN AND ANTICIPATED
WETBULBING. AS FOR POPS...ENDED UP CLOSE TO A BLEND OF THE DRIER MAV
AND WETTER MET NUMBERS TONIGHT INTO THURSDAY MORNING AND THEN
MATCHED THEIR DRY CONSENSUS INTO FRIDAY MORNING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 245 PM EST WED NOV 26 2014
THE SYNOPTIC PATTERN THROUGH THE LONG TERM PERIOD WILL FEATURE A
PROGRESSIVE FLOW ALOFT WITH A GENERAL SOUTHWEST FLOW IN THE LOW
LEVELS AS AN ELONGATED AREA OF SURFACE HIGH PRESSURE STRETCHES OUT
FROM THE DEEP SOUTH EASTWARD INTO THE WESTERN ATLANTIC. A COLD FRONT
WILL DROP SOUTH INTO THE REGION ON MONDAY...AND THEN STALL OUT IN
OUR VICINITY AS THE SPONSORING UPPER TROUGH PASSES BY TO THE NORTH.
A SECOND TROUGH WILL THEN FOLLOW A SIMILAR TRACK AND PASS BY TO OUR
NORTH MIDWEEK. FORECAST MODELS DIFFER ON THE STRENGTH OF THIS
SHORTWAVE AND THE RESULTING IMPACT IT WILL HAVE ON THE FRONT
AND FORECASTER CONFIDENCE DROPS BELOW AVERAGE BY THE END OF THE
PERIOD.
OUR SENSIBLE WEATHER WILL FEATURE A MODERATING TREND OVER THE
THANKSGIVING HOLIDAY WEEKEND. UNFORTUNATELY...THE WARMING TEMPS WILL
BE ACCOMPANIED BY INCREASING CLOUDS AND A FEW SHOWERS BY SATURDAY
NIGHT INTO THE DAY ON SUNDAY AS LOW LEVEL MOISTURE INCREASES. RAIN
CHANCES THEN INCREASE DRAMATICALLY SUNDAY NIGHT INTO MONDAY AS THE
FRONT DROPS INTO THE AREA. BEYOND MONDAY...TEMPS AND RAIN CHANCES
ARE PROBLEMATIC DUE TO THE MODEL DIFFERENCES REGARDING THE PLACEMENT
OF THE FRONT. SIDING WITH A MODEL BLEND YIELDS NEAR NORMAL TEMPS AND
A CHANCE OF RAIN EACH PERIOD THROUGH WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 100 PM EST WED NOV 26 2014
VFR CONDITIONS WILL PREVAIL THROUGH THE AREA INTO THE EVENING BEFORE
THE CIGS START TO DROP...PARTICULARLY AT THE SOUTHERN SITES. EXPECT
AN AREA OF RAIN AND SNOW TO SLIDE THROUGH THE CUMBERLAND VALLEY
OVERNIGHT WITH A GOOD CHANCE OF DROPPING VIS AND CIGS INTO THE MVFR
AND IFR RANGES AS THE SNOW DEVELOPS AND PASSES THROUGH. THE SME AND
LOZ SITES WILL LIKELY SEE THE WORST CONDITIONS...THOUGH IF THE PCPN
IS NOT ABLE TO WET BULB TO SNOW EFFECTIVELY...AT LEAST THE VIS WILL
NOT BE AS LOW AS CURRENTLY FORECASTED. EXPECT THE CONDITIONS TO
GRADUALLY IMPROVE THROUGH THE DAY THURSDAY ONCE THIS WAVE PASSES...
BUT CIGS WILL PROBABLY BE MVFR AT MOST SITES THROUGH THE MORNING.
WINDS WILL BE LIGHT AND VARIABLE THROUGH THE NIGHT BEFORE PICKING UP
A BIT FROM THE NORTHWEST INTO THE MORNING IN THE WAKE OF THE SFC LOW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...ABE
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
511 PM EST WED NOV 26 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 510 PM EST WED NOV 26 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS CONTINUE TO SHOW AN AMPLIFIED
PATTERN ACROSS NAMERICA WITH A RIDGE ALONG/JUST OFF THE W COAST...A
TROF EXTENDING FROM NCNTRL CANADA TO THE GULF OF MEXICO AND A RIDGE
OVER THE WRN ATLANTIC. A SHORTWAVE TROF SWINGING SE THRU NRN
ONTARIO/NRN MN IS PRODUCING SOME -SN FROM NW WI ACROSS WRN UPPER MI
INTO NRN ONTARIO. AT THE SFC...SHARPENING TROF RUNS FROM NEAR KIWD
TO JUST S OF KCMX AND THEN NE ACROSS ERN LAKE SUPERIOR. MDT TO HVY
LAKE ENHANCED SNOW IS SPREADING INTO WRN UPPER MI IN ASSOCIATION
WITH THE TROF. OFF TO THE NW...STRONG SFC HIGH PRES ACROSS
MANITOBA/SASKATCHEWAN IS BUILDING S AND E INTO THE NRN PLAINS.
PERIOD OF LAKE ENHANCED SNOW IS EXPECTED TONIGHT UNDER HEIGHT
FALLS/DEEP LAYER QVECTOR CONVERGENCE WITH SHORTWAVE SWINGING ACROSS
THE UPPER LAKES. BEST...MOST PERSISTENT LOW-LEVEL CONVERGENCE IS
INDICATED OVER THE FAR W. SO...MOST SUSTAINED MDT TO AT TIMES HVY
SNOW WILL OCCUR OVER THE FAR W FROM THE PORCUPINE MTNS TO KIWD. WITH
DGZ FALLING INTO THE LOW-LEVELS WHERE UPWARD MOTION IS FOCUSED...
EXPECT SNOW TO WATER RATIOS TO INCREASE INTO THE 20-30 TO 1 RANGE
TONIGHT. A LITTLE CONCERNED THAT THE UPWARD MOTION IS ONLY DEPICTED
IN THE LOWEST LEVELS THIS EVENING...SUGGESTING LITTLE OVERALL
SYNOPTIC SUPPORT WITH PASSING SHORTWAVE. THIS MAY TEND TO LIMIT
COVERAGE OF HVY SNOW TO ONLY THE AREAS WHERE LOW-LEVEL CONVERGENCE
IS FOCUSED. AS IT STANDS NOW...SITUATION APPEARS TO BE A MARGINAL
WARNING EVENT WITH WARNING THRESHOLDS ONLY POTENTIALLY BEING MET IN
A FEW LOCALIZED AREAS (8 INCHES OR MORE IN 12HRS OR 12 OR MORE IN
24HRS). LARGE PORTIONS OF ONTONAGON/GOGEBIC COUNTIES WILL PROBABLY
FALL IN THE 4 TO 7 INCH SNOWFALL RANGE. OF NOTE...THERE IS A FAIRLY
CONSISTENT SIGNAL AMONG MOST OF THE HIGH RES MODEL GUIDANCE FOR THE
HEAVIEST SNOW TO AFFECT LOCATIONS JUST W OF KIWD. WILL BE
INTERESTING TO SEE IF THAT INDEED DOES HAPPEN. OVER THE KEWEENAW...
SNOWFALL HAS NOT BEEN ESPECIALLY NOTEWORTHY WITH SFC TROF PASSAGE
WHICH IS WHEN THE HEAVIEST SNOWFALL WOULD LIKELY OCCUR. WITH A
DECENT LOW-LEVEL CONVERGENCE SIGNAL LACKING TONIGHT...CONSIDERED
DROPPING ADVY...BUT WILL HOLD OFF FOR NOW WITH POTENTIAL FOR SNOW TO
STILL PICK UP FOR A TIME THIS EVENING DURING THE PERIOD OF SYNOPTIC
FORCING. TO THE E...LONGER FETCH/BETTER TERRAIN ENHANCEMENT WILL
LEAD TO ANOTHER AREA OF HEAVIER SNOW DEVELOPING OVER NCNTRL UPPER MI
SPREADING FROM BARAGA COUNTY/FAR NRN MARQUETTE COUNTY EARLY THIS
EVENING TO ALGER COUNTY LATE EVENING. LOOKS LIKE SOLID ADVY AMOUNTS
FROM THE HURON MTNS TO NEGAUNEE AND EAST INTO WRN ALGER COUNTY.
POTENTIAL IS THERE FOR LOCALIZED WARNING AMOUNTS GIVEN THE
INCREASING SNOW TO WATER RATIOS AND THE LIKLIHOOD OF A LAKE NIPIGON
INITIATED DOMINANT BAND LATER TONIGHT INTO THE MORNING HRS THAT
WOULD LIKELY IMPACT LOCATIONS SOMEWHERE FROM AROUND BIG
BAY/MARQUETTE TO AROUND THE SHOT POINT AREA. IF SUCH A BAND DOES
DEVELOP AND BECOME STATIONARY FOR SEVERAL HRS...WARNING AMOUNTS MAY
BE ACHIEVED. BLSN WILL ALSO BE AN ISSUE IN THE OPEN AREAS ALONG LAKE
SUPERIOR WHERE WINDS WILL GUST OVER 30 MPH. WHILE THERE MAY BE A
BRIEF PERIOD OF HEAVIER SNOW OVER LUCE COUNTY WITH TROF PASSAGE...
SETUP AFTER TROF PASSAGE IS NOT FAVORABLE FOR ADVY SNOWFALL AMOUNTS
IN THAT AREA. ACROSS THE REST OF THE AREA...EXPECT SOME -SN FOR A
TIME TONIGHT. SOME OF THE LES OFF LAKE SUPERIOR WILL REACH NRN DELTA
AND SRN SCHOOLCRAFT COUNTIES TO PROVIDE AN INCH OR TWO OF SNOWFALL.
ON THANKSGIVING DAY...FCST SOUNDINGS SHOW INVERSIONS AT A LOW 4KFT
TO START THE DAY. LOW-LEVEL FLOW TRENDS ANTICYCLONIC DURING THE
DAY...ESPECIALLY SO OVER WRN LAKE SUPERIOR AS SFC HIGH PRES RIDGE
WILL EXTEND FROM THE MID MISSISSIPPI VALLEY N THRU WRN UPPER MI/WRN
LAKE SUPERIOR BY 00Z FRI. THESE 2 FACTORS COMBINED WITH RISING
HEIGHTS/LARGE SCALE SUBSIDENCE/QVECTOR DIVERGENCE WILL LIMIT LES
INTENSITY AND WILL RESULT IN LES DIMINISHING FROM W TO E THRU THE
DAY. IN FACT OVER THE FAR W...LES WILL END LATE IN THE AFTN AROUND
KIWD AS FLOW BACKS SW. THE ONE POSTIVE FACTOR FOR THE LES ON
THANKSGIVING DAY IS THAT THE DGZ WILL OCCUPY MOST OF THE CONVECTIVE
LAYER TO FLUFF UP SNOW ACCUMULATIONS. SO...DESPITE THE NEGATIVES
LEADING TO MOSTLY LIGHT LES ON THE WHOLE...MIGHT BE ABLE TO FLUFF UP
3-4 INCHES OF SNOW WHERE LES IS MOST PERSISTENT. THE GREATEST
ACCUMULATIONS WILL OCCUR E OF MARQUETTE WHERE LOW-LEVEL FLOW IS MORE
CYCLONIC THRU THE EARLY PART OF THE DAY AND WHERE LAKE NIPIGON
PRECONDITIONING WILL COME INTO PLAY. AWAY FROM THE MAIN LES...
SCT -SHSN/FLURRIES ARE POSSIBLE AT TIMES...EXCEPT OVER THE FAR
SCNTRL. TEMPS WILL BE UNSEASONABLY COLD ON THANKSGIVING DAY AS 850MB
THERMAL TROF (AROUND -20C) PASSES ACROSS THE AREA. EXPECT HIGHS
MOSTLY IN THE LOW/MID TEENS...TO AROUND 20F ALONG LAKE SUPERIOR AND
E. RECORD LOW MAX TEMP OF 18F HERE AT NWS MQT WILL FALL. IF TEMP
DOESN`T REACH 14F...IT WILL BE THE COLDEST MAX TEMP FOR SO EARLY IN
THE SEASON.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 342 PM EST WED NOV 26 2014
THU NIGHT...THE LINGERING LES WILL DIMINISH AS THE SFC RIDGE AXIS
SLIDES THROUGH THE WRN LAKES AND LOW LEVEL WINDS BACK TO THE SW.
WITH LIGHT WINDS AND A PERIOD OF CLEARING OVER THE INTERIOR WEST
DURING THE EVENING...TEMPS WILL DROP QUICKLY TO MINS BELOW GUIDANCE
BEFORE RECOVERING OVERNIGHT AS CLOUDS MOVE IN. MODELS WERE
CONSISTENT IN BRINGING POTENTIAL FOR SOME LIGHT SNOW INTO THE WEST
LATE WITH THE DEVELOPING WAA PATTERN.
FRI...SNOW IS EXPECTED TO SPREAD ACROSS THE REGION WITH FAVORABLE
MOISTURE ADVECTION AND ISENTROPIC LIFT THROUGH THE 850-700 MB
FRONTAL ZONE. 3 G/KG MOISTURE AVAILABLE IN THE 285K-295K LAYER
DURING THE PERIOD OF STRONGEST LIFT IS CONSISTENT WITH POTENTIAL FOR
2 TO 4 INCHES OF SNOW WITH MODELS CONSENSUS QPF OF 0.10 TO 0.20
INCHES AND SLR VALUES FROM AROUND 15/1-20/1. THERE IS STILL SOME
UNCERTAINTY WHERE THE BAND OF HEAVIER SNOW WILL DEVELOP AS THE 12Z
NAM BRINGS GREATER AMOUNTS OF PCPN INTO SRN UPPER MI COMPARED TO THE
GFS AND ECMWF. THERE WILL ALSO BE THE POTENTIAL FOR A BAND OF LAKE
ENHANCED SNOW OFF OF LAKE MI THAT COULD SPREAD EASTWARD FROM NEAR
THE GARDEN PENINSULA INTO LUCE COUNTY. SINCE THE STRONGEST LOW
LEVEL CONV IS EXPECTED TO MOVE STEADILY TO THE EAST...SNOW AMOUNTS
IN ANY ONE LOCATION SHOULD BE LIMITED. HOWEVER...CONFIDENCE IS LOWER
FOR THE POSITION/STRENGTH OF THIS FEATURE THAT COULD ADD SEVERAL
INCHES TO THE SNOW TOTALS.
FRI NIGHT INTO SAT...SFC LOW PRES IS FCST TO SPREAD FROM THE NRN
PLAINS TO THE UPPER MS VALLEY WITH CONTINUED WAA BRINGING
SUBSTANTIAL 850 MB WARMING. NAM/GFS 285-295K ISENTROPIC PROGS
SUGGEST THAT THE STRONGEST LIFT AND DEEPEST MOISTURE WILL REMAIN
ACROSS LAKE SUPERIOR AND FAR NRN UPPER MI. WITH A PROMINENT 850-700
MB DRY LAYER DEVELOPING TO THE SOUTH...FREEZING DRIZZLE WILL BE
POSSIBLE ALONG WITH SOME LIGHT SNOW OR FLURRIES AS ICE NUCLEI BECOME
MORE SCARCE. ANY PCPN AMOUNTS ARE EXPECTED TO BE LIGHT WITH
ONLY A FEW HUNDREDTHS OF AN INCH AT MOST. THERE MAY ALSO BE ENOUGH
900-700 MB WARMING INTO THE AREA OF DEEPER MOISTURE FOR SOME
FZRA.
SAT NIGHT AND SUN...LOW PRES LIFTING NE TOWARD JAMES BAY SAT NIGHT
WILL DRAG A COLD FRONT THROUGH THE NRN LAKES WITH MUCH COLDER AIR
MOVING IN ON NW WINDS. WITH 850 MB TEMPS FALLING TO NEAR -18C...LES
WILL BE LIKELY FOR NW WIND SNOW BELTS. A LIMITING FACTOR FOR HEAVIER
SNOW WILL BE SUBSTANTIAL 850-700 MB DRYING WITH BACKING AND
INCREASING ACYC LOW LEVEL WINDS FROM LATE SUN INTO SUN NIGHT.
MON-WED...THE GFS/GEFS AND ECMWF WERE IN REASONABLE AGREEMENT WITH
THE PATTERN INTO NEXT WEEK WITH HIGH PRES BUILDING INTO THE REGION
MON INTO MON NIGHT BRINGING DIMINISHING LES. ANOTHER MID LEVEL AND
SFC TROUGH MOVING THROUGH TUE INTO TUE NIGHT COULD BRING SOME LIGHT
SNOW TO THE AREA. THE MODELS HAVE TRENDED TOWARD KEEPING COLDER
ACROSS REGION THAT WOULD KEEP ANY PCPN AS SNOW WITH MAX TEMPS
RECOVERING INTO THE MID 20S TO AROUND 30 BY TUE AND WED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1245 PM EST WED NOV 26 2014
DISTURBANCE AND ASSOCIATED SFC TROF WILL SWING ACROSS UPPER MI THIS
AFTN/EVENING. INCREASING LAKE ENHANCED SNOW WILL AFFECT ALL
TERMINALS AS THE TROF PUSHES ACROSS THE AREA...BEGINNING LATEST AT
KSAW. AT KIWD/KCMX...IFR CONDITIONS ARE EXPECTED TO BECOME THE
PREVAILING CONDITION THIS AFTN...THOUGH SOME LIFR WILL OCCUR AS
WELL. WIND FLOW THIS EVENING WILL FAVOR KIWD FOR HEAVIEST
SNOW/LOWEST CONDITIONS...AND LIFR WILL LIKELY PREVAIL THERE THIS
EVENING WHILE KCMX REMAINS IFR. LOWERING INVERSION/DRYING AIR MASS
WILL RESULT IN DIMINISHING LAKE EFFECT SNOW LATER IN THE PERIOD...
ALLOWING IMPOVEMENT TO VFR. AT KSAW...VFR CONDITIONS WILL PREVAIL
THIS AFTN. WITH TROF PASSAGE...EXPECT CONDITIONS TO FALL TO IFR LATE
THIS EVENING ALONG WITH PERIODS OF LIFR. AS WINDS BEGIN TO BACK LATE
TONIGHT AND ESPECIALLY THU MORNING...LAKE EFFECT SNOW WILL SHIFT
MOSTLY E OF KSAW...ALLOWING IMPROVEMENT TO MVFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 348 PM EST WED NOV 26 2014
A SFC TROUGH WILL SLIDE SOUTH OVER LAKE SUPERIOR TONIGHT.
BEHIND THE TROUGH...EXPECT NORTHERLY WINDS TO 30 KTS. WINDS WILL
THEN DIMINISH TO UNDER 20 KT W TO E THU/THU NIGHT AS HIGH PRES RIDGE
ARRIVES. WITH ANOTHER COLD FRONT PUSHING ACROSS THE UPPER LAKES SAT
NIGHT...EXPECT INCREASING S/SW WINDS TO 15-25KT FRI INTO SAT AHEAD
OF FRONT. BEHIND THE FRONT...NW WINDS MAY REACH 20-30KT LATE SAT
NIGHT AND SUN AND INCREASE TO GALES BY SUN NIGHT INTO MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
THURSDAY FOR MIZ006.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THURSDAY FOR MIZ004.
LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THURSDAY FOR MIZ005.
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST /NOON CST/ THURSDAY FOR
MIZ002-009.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THURSDAY FOR MIZ001-003.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
318 PM CST WED NOV 26 2014
.SYNOPSIS...
ISSUED AT 318 PM CST WED NOV 26 2014
H5 ANALYSIS FROM THIS MORNING HAS A CLOSED LOW OVER
NUNAVUT WITH A TROUGH EXTENDING SWD INTO THE SERN CONUS. A COUPLE OF
UPPER LEVEL DISTURBANCES WERE NOTED OVER KENTUCKY AND NRN MO. STRONG
WINDS WERE NOTED IN THE MID LEVELS AS A 90+KT H5 JET STREAK EXTENDED
FROM WESTERN MT INTO SWRN KS. AT THE SURFACE...LOW PRESSURE WAS
PRESENT OVER NRN MO WITH A COLD FRONT EXTENDING SOUTH AND WEST OF
THE LOW INTO THE OZARKS AND TX PANHANDLE. COLD AIR BEHIND THE FRONT
HAS BACKED TO ALONG THE FRONT RANGES OF THE ROCKIES IN COLORADO AND
WYOMING. LOOKING AT THE H7 THERMAL FIELD...A DECENT FRONTAL BOUNDARY
EXTENDED ACROSS THE PANHANDLE AND EXTREME SOUTHWESTERN NEBRASKA. THE
H7 FRONT...COUPLED WITH THE H5 JET STREAK...HAS LED TO LIGHT SNOW
ACROSS THE PANHANDLE AND NORTHEASTERN COLORADO THIS AFTERNOON. SKIES
WERE MOSTLY CLOUDY ACROSS WESTERN AND NORTH CENTRAL NEBRASKA THIS
AFTERNOON. TEMPERATURES AS OF MID AFTERNOON RANGED FROM 25 AT ONEILL
TO 34 AT NORTH PLATTE AND OGALLALA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 318 PM CST WED NOV 26 2014
LOW TO MID LEVEL FRONTOGENETIC BAND CURRENTLY
ACROSS SOUTHWEST NEBRASKA IS SHOWN BY THE HIRES NEAR TERM MODELS TO
BECOME LESS DEFINED THROUGH THE AFTERNOON AS THE ATMOSPHERE LOSES
SATURATION IN THE DENDRITIC GROWTH ZONE. THE HRRR SEEMS TO BE
HANDLING THE CURRENT SITUATION WELL...THUS THE FORECAST WAS TRENDED
IN THAT DIRECTION WITH SNOW ENDING ACROSS OUR SOUTHWEST THIS
EVENING. THE LATEST HRRR DOES SHOW ANOTHER PUSH OF LOWER LEVEL
MOISTURE THIS EVENING...THUS THE REASON OF EXTENDING A SNOW MENTION
INTO THIS EVENING. ACROSS NORTH CENTRAL NEBRASKA THIS
EVENING...BUFR SOUNDINGS SHOW DEEP SATURATION...WHICH AT TIMES
REACHES INTO THE DGZ...WHATS MISSING IS DEEP LIFT...BUT THERE ARE
INDICATIONS OF AT LEAST WEAK OMEGA. PREVIOUS FORECAST HANDLED THIS
POTENTIAL WITH --SN...WILL DO THE SAME.
OVERNIGHT LOWS WILL BE CHILLY...WITH LESS MIXING IN MIND OVERNIGHT
LOWS SHOULD BOTTOM OUT IN THE TEENS ACROSS THE EAST...WITH LOWER 20S
OVER THE HIGHER TERRAIN OF THE WEST.
TOMORROW...A GENERAL WARMING AND DRYING TREND IS FORECAST BY ALL
AVAILABLE GUIDANCE AS SFC HIGH PRESSURE BUILDS OFF TO THE EAST AND A
LEE TROUGH DEEPENS TO THE WEST. SOUTHERLY...TO WESTERLY FLOW WILL
ADVECT WARMER H85 TEMPS ACROSS THE REGION...WITH OUR FAR WESTERN &
SOUTHWESTERN ZONES TOPPING 10C BY 00Z FRIDAY. THIS SHOULD PROVIDE
FOR TEMPERATURES IN THE LOWER 60S ACROSS SOUTHWEST NEBRASKA AND THE
EASTERN PANHANDLE. THERE WILL REMAIN A SHARP GRADIENT OF
TEMPERATURES AS ONE HEADS EAST. ACROSS THE HEART OF THE SANDHILLS
HIGHS IN THE 40S AND 50S SHOULD PREVAIL...TO THE EAST OF
THERE...ACROSS NORTH CENTRAL NEBRASKA...HIGHS MAY STRUGGLE TO REACH
INTO THE MID 30S...OWING THE PRESENCE OF PERSISTENT STRATUS AND
COOLER AIR RECYCLED FROM THE DEPARTING HIGH. YOUR THANKSGIVING
FORECAST IS DRY AS THE TROPOSPHERIC COLUMN IS SHOWN TO DRY ON
THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 318 PM CST WED NOV 26 2014
MID RANGE...THURSDAY NIGHT THROUGH SATURDAY...IN THE
MID RANGE...UNSEASONABLY WARM AND DRY CONDITIONS ARE
EXPECTED...WITH THE MAIN FORECAST CHALLENGE BEING HIGH TEMPERATURES
FOR FRIDAY AND SATURDAY. FOR THURSDAY NIGHT...A WARM FRONT WILL
CONTINUE TO LIFT NORTHEAST OF THE AREA INTO NORTH DAKOTA AND
MINNESOTA. A WEAK SURFACE TROUGH OF LOW PRESSURE WILL DEVELOP ACROSS
THE HIGH PLAINS OF NEBRASKA AND KANSAS OVERNIGHT LEADING TO LIGHT
WESTERLY WINDS. OVERNIGHT LOWS WILL BE ON THE MILD SIDE FOR THIS TIME OF
YEAR WITH READINGS AROUND 25 FORECAST FOR FRIDAY MORNING. WITH LIGHT
WESTERLY WINDS FORECAST...WENT WITH SOME LOWER 20S IN THE PLATTE
RIVER VALLEY. FRIDAY AND FRIDAY NIGHT...WARM H85 TEMPS WILL PUSH
INTO THE REGION WITH H85 TEMPS RANGING FROM 8 TO 16C. THIS WILL
RESULT IN HIGHS WELL INTO THE 50S TO MIDDLE 60S FRIDAY AFTERNOON. ON
FRIDAY NIGHT...LOWS WILL BE MILD WITH TEMPERATURES IN THE UPPER 20S
TO LOWER 30S EXPECTED. ON SATURDAY...AN ARCTIC COLD FRONT WILL PUSH
INTO THE DAKOTAS...ENDING UP SOMEWHERE IN SOUTH DAKOTA BY 00Z
SUNDAY. THE EURO SOLN IS MOST AGGRESSIVE WITH THE FRONT BEING ALONG
THE SD/NE BORDER BY THIS TIME. THE NAM AND GFS ARE SLOWER AND HAVE
THE FRONT OVER CENTRAL AND NORTHERN SD DURING 00Z SUNDAY.
REGARDLESS...THE FRONT WILL BE NORTH OF THE FORECAST AREA BEFORE
PEAK HEATING. WITH THE APPG FRONT AND H85 TEMPS REACHING THE MIDDLE
TO UPPER TEENS SAT AFTN...HIGHS WILL SURGE INTO THE 60S AND MAY
APPROACH 70 IN THE SOUTHWEST. RECORDS FOR SATURDAY ARE IN THE MID
70S FOR VALENTINE AND IMPERIAL...AND 71 FOR NORTH PLATTE AND 69 FOR
BROKEN BOW RESPECTIVELY.
LONG RANGE...SATURDAY NIGHT THROUGH WEDNESDAY...A STRONG ARCTIC
FROPA WILL PUSH THROUGH THE FORECAST AREA SATURDAY NIGHT. FORECAST
WILL CONTINUE TO BE DRY BEHIND THE FRONT WITH THE BEST FORCING OVER
NORTH DAKOTA AND NRN MINNESOTA. H85 TEMPS BEHIND THE FRONT SUNDAY
WILL RANGE FROM -13C IN THE NORTH TO -7C IN THE SOUTH. WITH DECENT
NORTHERLY WINDS AND MIXING HIGHS WILL STRUGGLE TO GET OUT OF THE 20S
SUNDAY. TEMPERATURES WILL MODERATE SOME MONDAY...WITH A BETTER
WARMUP EXPECTED ON TUESDAY AND WEDNESDAY. BY WEDNESDAY...THE
PRECIPITATION FORECAST BECOMES MORE OF A CHALLENGE THANKS TO SPLIT
FLOW. THE LATEST GFS AND ECMWF HAVE DIVERGENT SOLUTIONS TOWARD THE
MIDDLE OF THE WEEK. THE GFS IS MOST AGGRESSIVE...PUSHING A SHORTWAVE
TROUGH ACROSS THE INTERMOUNTAIN WEST WEDNESDAY...WHILE THE ECMWF HAS
THE TROUGH IN NRN CALIFORNIA. WITH THE MODEL DISAGREEMENTS
ATTM...WILL LEAVE THE PERIOD DRY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1105 AM CST WED NOV 26 2014
.AVIATION...MODEL GUIDANCE CONTINUES TO INDICATE MVFR OR LOWER
CEILINGS THAT WILL EVENTUALLY BREAK THIS AFTERNOON AT KLBF. SKIES
ARE ANTICIPATED TO BE VFR BY 20Z. AT KVTN...SKIES WILL REMAIN
OVERCAST THROUGH MUCH OF THE DAY...IN FACT MUCH OF THE NEAR TERM
GUIDANCE INDICATES KVTN REMAINING AT MVFR OR LOWER THROUGH THE
FORECAST CYCLE. WILL BRIEFLY INCLUDE A SCT030 CEILING THIS
AFTERNOON AT KVTN...BUT THEN TREND SKIES BELOW MVFR THIS EVENING.
OTHERWISE -SN IS CURRENTLY FALLING ACROSS THE EASTERN
PANHANDLE...IMPACTS FROM THE SNOW THIS AFTERNOON WILL BE MINIMAL AS
VISBY REDUCTIONS WILL ONLY FALL BRIEFLY BLO 6SM...THIS SNOW IS NOT
ANTICIPATED TO IMPACT KLBF OR KVTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...JACOBS
LONG TERM...CLB
AVIATION...KECK/JACOBS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
559 PM EST WED NOV 26 2014
.SYNOPSIS...
SNOW WILL CONTINUE INTO THIS EVENING...BEFORE WINDING DOWN LATE
TONIGHT...AS A STRENGTHENING STORM SYSTEM TRACKS FARTHER OFF THE
EAST COAST. A SERIES OF UPPER-LEVEL DISTURBANCES WILL BRING
OCCASIONAL LIGHT SNOW SHOWERS AND FLURRIES FRIDAY AND
SATURDAY...WITH TEMPERATURES STAYING ON THE CHILLY SIDE.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
4 PM UPDATE... BASED ON PERSISTENCE OF NARROW CSI BAND...AND THE
EXPECTATION OF ANOTHER 2-3 HRS OF +SN UNDERNEATH IT...WE`VE ADDED
BRADFORD PA AND TIOGA NY TO THE WRNG AREA (STORM TOTALS OF
5-10").
3 PM UPDATE... FOR THE MOST PART...ONGOING WINTER STORM IS
BEHAVING ITSELF...AS A DEEPENING SURFACE CYCLONE IS MOVING NEWD
OFF THE MID-ATLANTIC COAST.
OF PRIMARY CONCERN LATE THIS AFTN INTO THE EVE HRS IS THE TRACK
OF THE MID-LVL LOW (700 MB)...AND AN ASSOCD BAND OF FGEN
FORCING...FROM CNTRL/NERN PA INTO PTNS OF NY`S SRN TIER...THEN
NEWD FROM THERE. BASED ON THE LATEST OBSERVATIONAL DATA...SPC
MESO-ANALYSES...AND THE LATEST HI-RES MODEL OUTPUT...THE MAIN BAND
OF +SN MAY WELL IMPACT AN AXIS FROM NEAR WILLIAMSPORT...TO
TOWANDA...TO BINGHAMTON...TO NORWICH AND COOPERSTOWN THROUGH AT
LEAST 21-23Z...WITH A GENERAL EWD SHIFT THEREAFTER. ACRS OUR SERN
ZNS...PROXIMITY OF A MID-LVL DRY SLOT MAY CAUSE SNOW TO OCNLLY
DECREASE...BUT IT`S NOT LIKELY TO SHUT DOWN ALTOGETHER UNTIL LTR
THIS EVE...SO ADDITIONAL ACCUMS ARE STILL ANTICIPATED EVEN IN
THESE AREAS. ALL IN ALL...CURRENTLY ADVERTISED SNOWFALL TOTALS
STILL LOOK REASONABLE...WITH A GENERAL 6-12" IN THE WRNG
AREA OVER MOST OF NERN PA...THE CATSKILLS...AND SXNS OF THE SUSQ RGN...AND
ROUGHLY 3-6" IN THE ADVISORY RGN...FROM KELM-KITH-KSYR.
BASED ON THE LATEST HRRR DATA...WHICH HAS PERFORMED WELL TDY...THE
BACK EDGE OF THE STEADIER SNOW PULLS OUT FROM W TO E AFTER 01-03Z.
ALTHOUGH WE COULD SEE SOME WEAK MULTI-BANDS TWDS DAYBREAK IN A
310-330 FLOW...THE OVERALL FLOW LOOKS WEAK...AND MOISTURE DEPTHS
WILL BE ON THE DECLINE...SO ACCUMS SHOULD BE VERY MINOR.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
FOR THANKSGIVING DAY AND THU NGT...A NW FLOW PATN WILL
PREVAIL...WITH LOW-LVL CAA...AND LINGERING BLYR MOISTURE. FOR THE
MOST PART...THIS WILL PRODUCE -SHSN AND FLRYS...AND SMALL ACCUMS.
HOWEVER...A BRIEF PD OF ENHANCEMENT COULD OCCUR LTR THU NGT INTO
FRI MRNG...WHEN A WELL DEFINED NRN STREAM S/WV CROSSES NY/PA. SOME
SYNOPTIC SUPPORT FROM THE S/WV AND LK ENHANCEMENT COULD PRODUCE
LOCALLY 1-3" IN AN AXIS FROM SRN CAYUGA-ONONDAGA...TO SRN
ONEIDA/MADISON/NRN CHENANGO/NRN OTSEGO.
FOR THE REST OF THE DAY FRI INTO FRI NGT...MAINLY JUST SCTD
-SHSN/FLRYS ARE AGN ANTICIPATED...WITH BACKING LOW-LVL FLOW...AS
SOME WARM ADVECTION BEGINS.
ANOTHER S/WV PASSAGE...ALG WITH THE APPROACH OF THE SFC-850 MB
WARM FRNT FROM THE SW...COULD LEAD TO ADDTNL -SHSN AND SOME LGT
ACCUMS AS WE HEAD INTO EARLY SAT...SPCLY FOR OUR NRN ZNS.
DAILY HIGHS WILL GENERALLY BE IN THE 30S...WITH LOWS IN THE UPR
TEENS AND 20S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
230 PM EST UPDATE...
FOLLOWED CLOSELY WITH WPC GUIDANCE AND MADE MINOR CHANGES TO THE
PREVIOUS FORECAST.
THE MAIN THEME OF THE FORECAST CONTINUES WITH ZONAL FLOW STILL
BEING EXPECTED ACROSS MUCH OF THE NORTHEAST THROUGH THE FORECAST
PERIOD.
BY SAT NIGHT A WARM FRONT WILL HAVE JUST PASSED TO THE NORTH OF
THE CWA AND A COLD FRONT WILL BE STARTING TO APPROACH THE REGION
FROM THE WEST. THIS COLD FRONT WILL BRING COOLER AIR TO THE REGION
ALONG WITH A CHANCE FOR RAIN/AND OR SNOW SHOWERS TO NEW YORK AND
PENNSYLVANIA. A SFC RIDGE WILL THEN START TO BUILD OVER THE AREA
FROM THE WEST MONDAY AFTERNOON... THUS BRINGING DRY AND QUIET
WEATHER BACK TO THE AREA THROUGH MID WEEK. THIS RIDGE WILL ALSO ALLOW
TEMPERATURES OVER THE REGION TO FALL BELOW THE SEASONAL NORM. THE
COLDEST DAY IN THE EXTENDED FORECAST WILL BE WHEN THE RIDGE IS EXPECTED
TO BE CENTERED OVER THE CWA. THIS WILL OCCUR ON TUESDAY. HIGH
TEMPERATURES ARE EXPECTED TO RISE INTO THE LOW TO MID 30S.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AN INTENSE BAND OF SNOW EXTENDING FROM NORTHEASTERN NY TOWARD THE
AVP TERMINAL WILL CAUSE IFR CONDITIONS FOR A FEW MORE HOURS. THE
SNOW WILL TAPER OFF BETWEEN 2Z AND 5Z, WITH MOST TERMINALS POPPING
BACK UP TO BETWEEN 2SM AND 5SM VISIBILITY ONCE THE BAND MOVES OUT
OR WEAKENS.
A GENERAL LIGHT SNOWFALL WILL PERSIST INTO EARLY THURSDAY WITH
LIGHT WINDS AND MAINLY MFVR RESTRICTIONS.
OUTLOOK...
THU NGT/FRI/SAT...POSSIBLE RESTRICTIONS FROM SCT -SHSN...ESPECIALLY
KSYR-KRME.
SUN...RESTRICTIONS POSSIBLE FROM -SHRA.
MON...RESTRICTIONS POSSIBLE FROM -SHRA/SHSN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR PAZ038>040-
043-044-047-048-072.
NY...WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR NYZ045-046-
055>057-062.
WINTER WEATHER ADVISORY UNTIL 6 AM EST THURSDAY FOR NYZ009-017-
018-024-025-036-037-044.
&&
$$
SYNOPSIS...MLJ
NEAR TERM...MLJ
SHORT TERM...MLJ
LONG TERM...KAH
AVIATION...DJP/PCF
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
353 PM EST WED NOV 26 2014
.SYNOPSIS...
SNOW WILL CONTINUE INTO THIS EVENING...BEFORE WINDING DOWN LATE
TONIGHT...AS A STRENGTHENING STORM SYSTEM TRACKS FARTHER OFF THE
EAST COAST. A SERIES OF UPPER-LEVEL DISTURBANCES WILL BRING
OCCASIONAL LIGHT SNOW SHOWERS AND FLURRIES FRIDAY AND
SATURDAY...WITH TEMPERATURES STAYING ON THE CHILLY SIDE.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
4 PM UPDATE... BASED ON PERSISTENCE OF NARROW CSI BAND...AND THE
EXPECTATION OF ANOTHER 2-3 HRS OF +SN UNDERNEATH IT...WE`VE ADDED
BRADFORD PA AND TIOGA NY TO THE WRNG AREA (STORM TOTALS OF
5-10").
3 PM UPDATE... FOR THE MOST PART...ONGOING WINTER STORM IS
BEHAVING ITSELF...AS A DEEPENING SURFACE CYCLONE IS MOVING NEWD
OFF THE MID-ATLANTIC COAST.
OF PRIMARY CONCERN LATE THIS AFTN INTO THE EVE HRS IS THE TRACK
OF THE MID-LVL LOW (700 MB)...AND AN ASSOCD BAND OF FGEN
FORCING...FROM CNTRL/NERN PA INTO PTNS OF NY`S SRN TIER...THEN
NEWD FROM THERE. BASED ON THE LATEST OBSERVATIONAL DATA...SPC
MESO-ANALYSES...AND THE LATEST HI-RES MODEL OUTPUT...THE MAIN BAND
OF +SN MAY WELL IMPACT AN AXIS FROM NEAR WILLIAMSPORT...TO
TOWANDA...TO BINGHAMTON...TO NORWICH AND COOPERSTOWN THROUGH AT
LEAST 21-23Z...WITH A GENERAL EWD SHIFT THEREAFTER. ACRS OUR SERN
ZNS...PROXIMITY OF A MID-LVL DRY SLOT MAY CAUSE SNOW TO OCNLLY
DECREASE...BUT IT`S NOT LIKELY TO SHUT DOWN ALTOGETHER UNTIL LTR
THIS EVE...SO ADDITIONAL ACCUMS ARE STILL ANTICIPATED EVEN IN
THESE AREAS. ALL IN ALL...CURRENTLY ADVERTISED SNOWFALL TOTALS
STILL LOOK REASONABLE...WITH A GENERAL 6-12" IN THE WRNG
AREA OVER MOST OF NERN PA...THE CATSKILLS...AND SXNS OF THE SUSQ RGN...AND
ROUGHLY 3-6" IN THE ADVISORY RGN...FROM KELM-KITH-KSYR.
BASED ON THE LATEST HRRR DATA...WHICH HAS PERFORMED WELL TDY...THE
BACK EDGE OF THE STEADIER SNOW PULLS OUT FROM W TO E AFTER 01-03Z.
ALTHOUGH WE COULD SEE SOME WEAK MULTI-BANDS TWDS DAYBREAK IN A
310-330 FLOW...THE OVERALL FLOW LOOKS WEAK...AND MOISTURE DEPTHS
WILL BE ON THE DECLINE...SO ACCUMS SHOULD BE VERY MINOR.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
FOR THANKSGIVING DAY AND THU NGT...A NW FLOW PATN WILL
PREVAIL...WITH LOW-LVL CAA...AND LINGERING BLYR MOISTURE. FOR THE
MOST PART...THIS WILL PRODUCE -SHSN AND FLRYS...AND SMALL ACCUMS.
HOWEVER...A BRIEF PD OF ENHANCEMENT COULD OCCUR LTR THU NGT INTO
FRI MRNG...WHEN A WELL DEFINED NRN STREAM S/WV CROSSES NY/PA. SOME
SYNOPTIC SUPPORT FROM THE S/WV AND LK ENHANCEMENT COULD PRODUCE
LOCALLY 1-3" IN AN AXIS FROM SRN CAYUGA-ONONDAGA...TO SRN
ONEIDA/MADISON/NRN CHENANGO/NRN OTSEGO.
FOR THE REST OF THE DAY FRI INTO FRI NGT...MAINLY JUST SCTD
-SHSN/FLRYS ARE AGN ANTICIPATED...WITH BACKING LOW-LVL FLOW...AS
SOME WARM ADVECTION BEGINS.
ANOTHER S/WV PASSAGE...ALG WITH THE APPROACH OF THE SFC-850 MB
WARM FRNT FROM THE SW...COULD LEAD TO ADDTNL -SHSN AND SOME LGT
ACCUMS AS WE HEAD INTO EARLY SAT...SPCLY FOR OUR NRN ZNS.
DAILY HIGHS WILL GENERALLY BE IN THE 30S...WITH LOWS IN THE UPR
TEENS AND 20S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
230 PM EST UPDATE...
FOLLOWED CLOSELY WITH WPC GUIDANCE AND MADE MINOR CHANGES TO THE
PREVIOUS FORECAST.
THE MAIN THEME OF THE FORECAST CONTINUES WITH ZONAL FLOW STILL
BEING EXPECTED ACROSS MUCH OF THE NORTHEAST THROUGH THE FORECAST
PERIOD.
BY SAT NIGHT A WARM FRONT WILL HAVE JUST PASSED TO THE NORTH OF
THE CWA AND A COLD FRONT WILL BE STARTING TO APPROACH THE REGION
FROM THE WEST. THIS COLD FRONT WILL BRING COOLER AIR TO THE REGION
ALONG WITH A CHANCE FOR RAIN/AND OR SNOW SHOWERS TO NEW YORK AND
PENNSYLVANIA. A SFC RIDGE WILL THEN START TO BUILD OVER THE AREA
FROM THE WEST MONDAY AFTERNOON... THUS BRINGING DRY AND QUIET
WEATHER BACK TO THE AREA THROUGH MID WEEK. THIS RIDGE WILL ALSO ALLOW
TEMPERATURES OVER THE REGION TO FALL BELOW THE SEASONAL NORM. THE
COLDEST DAY IN THE EXTENDED FORECAST WILL BE WHEN THE RIDGE IS EXPECTED
TO BE CENTERED OVER THE CWA. THIS WILL OCCUR ON TUESDAY. HIGH
TEMPERATURES ARE EXPECTED TO RISE INTO THE LOW TO MID 30S.
&&
.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
A LARGE WINTER STORM WILL PRODUCE WIDESPREAD IFR VSBYS AT ALL
TERMINALS THROUGH THIS EVENING. THE HEAVIEST SNOW WILL FALL
THROUGH THIS AFTERNOON AND FALL FROM NEAR KBGM EXTENDING EAST AND
SOUTH. AS A RESULT, VISIBILITIES BELOW AIRPORT MINIMUMS CAN BE EXPECTED
FOR KBGM AND KAVP AT TIMES THIS AFTERNOON.
CONDITIONS WILL START TO IMPROVE THIS EVENING AS THE HEAVIEST
PRECIP LIFTS NORTH AND EAST ALTHOUGH WE DON`T EXPECT CONDITIONS TO
IMPROVE ABOVE IFR UNTIL AROUND MIDNIGHT DUE TO LINGERING LIGHT
SNOW. EXPECT MVFR CEILINGS/VISBYS TO LINGER THROUGH TONIGHT IN
SCATTERED SNOW SHOWERS FOR ALL SITES EXCEPT KELM AND KAVP.
OUTLOOK...
THU/FRI/SAT...POSSIBLE RESTRICTIONS FROM SCT -SHSN...ESPECIALLY
KSYR-KRME.
SUN...RESTRICTIONS POSSIBLE FROM -SHRA.
MON...RESTRICTIONS POSSIBLE FROM -SHRA/SHSN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR PAZ038>040-
043-044-047-048-072.
NY...WINTER STORM WARNING UNTIL 6 AM EST THURSDAY FOR NYZ045-046-
055>057-062.
WINTER WEATHER ADVISORY UNTIL 6 AM EST THURSDAY FOR NYZ009-017-
018-024-025-036-037-044.
&&
$$
SYNOPSIS...MLJ
NEAR TERM...MLJ
SHORT TERM...MLJ
LONG TERM...KAH
AVIATION...PCF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
328 PM CST WED NOV 26 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 328 PM CST WED NOV 26 2014
FORECAST CHALLENGE FOR THE SHORT TERM WILL BE OVERNIGHT LOWS
TONIGHT AS WELL AS TIMING AND AMOUNT OF SNOW THANKSGIVING NIGHT. A
SURFACE HIGH WILL DROP INTO THE VALLEY TONIGHT AND BRING A VERY
COLD AND DRY AIR MASS. THIS WILL RESULT IN OVERNIGHT LOWS WELL
BELOW SEASONAL NORMS. A CLIPPER THEN MOVES INTO EASTERN MONTANA
TOMORROW NIGHT AND A BAND OF SNOW IS EXPECTED TO FORM OVER
PORTIONS OF CENTRAL AND EASTERN NORTH DAKOTA ON INTO NORTHWEST
MINNESOTA. HAVE USED A BLEND OF NAM DNG AND HRRR FOR OVERNIGHT
LOWS TONIGHT AND A MODEL BLEND FOR THE THANKSGIVING NIGHT SYSTEM
AS THERE ARE STILL VARIATIONS ON THE PLACEMENT OF SNOW.
TONIGHT...CURRENT VIS SATELLITE SHOWS CLEARING LINE HAS MADE IT AS
FAR SOUTH OF I 94. DEW POINTS NORTH OF THIS MID CLOUD DECK ARE
ALREADY 5 TO 10 BELOW AND IN THE MID TEENS BELOW ACROSS SOUTHERN
MANITOBA. THE RIDGE AXIS EXTENDING OUT OF A HIGH OVER MANITOBA WILL
BRING CALM WINDS TO THE DVL REGION EARLY IN THE EVENING...AND WITH
A LIGHT COVERING OF FRESH SNOW THE TEMPS SHOULD QUICKLY DROP TO 5
TO 10 BELOW THIS EVENING. BY MORNING...RETURN FLOW SETS UP OVER
THE DEVILS LAKE BASIN REGION UP THROUGH
TOWNER/PEMBINA/CAVALIER COUNTIES. THIS WILL ALLOW WIND CHILLS TO
DROP INTO THE 20 TO 25 BELOW RANGE TONIGHT...AND EVENING SHIFT
WILL NEED TO MONITOR CLOSELY AS COLDER TEMPS WOULD BRING AREA INTO
WIND CHILL ADVISORY CRITERIA (LESS THAN 25 BELOW ZERO). WARMEST
TEMPS SHOULD BE ACROSS THE FAR SOUTH AS THE CURRENT MID CLOUDS
WILL DELAY RADIATIONAL COOLING FOR AT LEAST A FEW HOURS THIS
EVENING...BUT EXPECT THAT AREA TO CLEAR OUT BY 02Z TO 03Z. DEW
POINTS ARE ABOUT 10 DEG HIGHER IN THIS REGION SO NOT LOOKING FOR
AS SIGNIFICANT OF A DROP OFF. RIDGE AXIS SHOULD THEN BE OVER THE
EAST TOMORROW MORNING AND TEMPS SHOULD DROP TO AROUND 10 BELOW.
TOMORROW AND TOMORROW NIGHT...A VERY COLD START TO THE DAY WILL LIMIT
DAYTIME HIGHS DESPITE SOME SOLAR IN THE MORNING BEFORE WE SEE
INCREASING CLOUDS FROM WEST TO EAST TOMORROW AFTERNOON. TEMPS WILL
STRUGGLE TO BREAK 10 ABOVE. BAND OF SNOW ASSOCIATED WITH WARM
ADVECTION AND ISENTROPIC LIFT WILL SET UP OVER WESTERN ND TOMORROW
MORNING AND MOVE INTO CNTRL ND IN THE AFTN. A BAND OF ISENTROPIC
LIFT INTENSIFIES AND MOVES INTO THE WESTERN CWA BETWEEN 00Z AND
06Z. NAM 280K ISENTROPIC SFC WINDS IN THE 20 TO 30 KT RANGE ARE
DIRECTLY PERPENDICULAR TO THE PRESSURE GRADIENT AND SHOULD BE
SUFFICIENT TO LIFT THE PARCEL ABOUT 100 MB...WITH NEARLY SATURATED
CONDENSATION PRESSURE DEFICITS IN EASTERN NORTH DAKOTA. THERE IS
STILL DIFFERENCES IN THE PLACEMENT OF THE SNOW...WITH ECMWF A BIT
FURTHER SOUTH AND WEST THAN THE 18Z NAM AND 12Z GFS. HPC QPF
GUIDANCE PREFERS THE SLIGHTLY NORTHWARD SOLUTION...AND HAVE
UPDATED SNOW RATIOS TO YIELD 3 TO 4 INCHES IN NORTH OF THE DEVILS
LAKE REGION DOWN THROUGH THE CENTRAL VALLEY.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 328 PM CST WED NOV 26 2014
FRIDAY...SNOW SHOULD BEGIN TAPERING OFF FRIDAY MORNING BUT
PORTIONS OF EASTERN NORTH DAKOTA TO INCLUDE THE NORTHERN VALLEY
WILL HAVE ANOTHER TWO TO FOUR INCHES OF SNOW. MOTORISTS IN
NORTHEASTERN NORTH DAKOTA CAN EXPECT LESS THAN DESIRABLE DRIVING
CONDITIONS FOR BLACK FRIDAY SHOPPING...ESPECIALLY IN THE EARLY
MORNING HOURS. ANOTHER SFC LOW ENTERS EASTERN MT FRI AFTN AND
MOVES INTO THE DAKOTAS OVERNIGHT. MODELS CONTINUING TO DIFFER ON
QPF AMOUNTS AND PLACEMENT OF THIS SECOND SHOT OF SNOW. GFS IS THE
MOST BULLISH AND BRINGS SOUTHERN EDGE OF SNOW BAND DOWN TO THE
HIGHWAY 2 CORRIDOR WHILE THE NAME IS FAIRLY DRY AND THE ECMWF
KEEPS SNOW MAINLY NORTH OF INTL BORDER. DO TO MODEL INCONSISTENCY
WILL USE CONTINUITY AS SOLUTION...WITH LOW CHANCE POPS ACROSS THE
NORTHERN TIER OF COUNTIES. WILL LIKELY SEE A BREAK MID DAY BETWEEN
THE TWO SNOW PRODUCING SYSTEMS SHOULD THE SNOW SET UP ALONG AND
NORTH OF HWY 200...THE MOST LIKELY AREA FOR ADDITIONAL
ACCUMULATION. DAYTIME HIGHS WILL BE WARMER ON FRIDAY AND JUMP
INTO THE MID 20S ACROSS THE SOUTH.
SATURDAY...GFS/ECMWF CONTINUE TO SHOW LINGERING SNOW SHOWERS
ACROSS THE NORTH AS NW SFC FLOW SETS UP...WHILE THE NAM REMAINS
DRY. WILL KEEP CONTINUITY FOR THIS PERIOD AS WELL...ALTHOUGH ANY
SNOW ON SATURDAY SHOULD BE LIGHT WITH LITTLE ACCUMULATION.
SATURDAY NIGHT THROUGH WEDNESDAY...MODELS START OUT IN FAIRLY DECENT
AGREEMENT...PUSHING A POSITIVELY TILTED TROUGH THROUGH THE NORTHERN
ROCKIES AND PLAINS OVER THE WEEKEND. THE COLD FRONT WILL MOVE
THROUGH THE CWA SATURDAY NIGHT AND COLD HIGH PRESSURE WILL BE IN
PLACE FOR SUNDAY. CONTINUED TO KEEP SOME 30ISH POPS FOR WHEN THE
FRONTAL BOUNDARY PASSES...THEN DRYING OUT INTO THE EARLY PART OF THE
WORK WEEK. TEMPS WILL AGAIN BE WELL BELOW AVERAGE WITH LOWS IN THE
TEENS BELOW ZERO AND HIGHS IN THE SINGLE DIGITS ABOVE FOR SUNDAY AND
MONDAY.
MODEL CONSENSUS STARTS TO DIVERGE BY TUESDAY AND WEDNESDAY. THE GFS
IS MORE ACTIVE AND BRING A VIGOROUS SHORTWAVE THROUGH THE NORTHERN
PLAINS WITH SFC LOW PRESSURE JUST TO OUR NORTH AND THE CWA SHOWING
SOME STRONG WARM AIR ADVECTION MONDAY AND EARLY TUESDAY BEFORE THE
NEXT COLD FRONT COMES IN. THE ECMWF IS WEAKER AND DRIER. ENSEMBLE
MEMBERS SHOW A GOOD AMOUNT OF SPREAD...SO FOR NOW KEPT ONLY MINIMAL
POPS AS THE OPERATIONAL GFS IS ONE OF THE WETTER SOLUTIONS. TEMPS
SHOULD SEE SOME WARMING ON TUESDAY AND COLDER AGAIN ON
WEDNESDAY...BUT EVEN THE HIGHER TEMP DAYS WILL STILL BE BELOW
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1258 PM CST WED NOV 26 2014
SOME MID LEVEL CLOUD CONTINUES TO LINGER ACROSS PORTIONS OF THE
FORECAST AREA...BUT CONDITIONS WILL REMAIN VFR AND SKIES WILL CLEAR
FROM NORTH TO SOUTH THROUGH THE REST OF THE AFTERNOON. NORTH WINDS
WILL BECOME LIGHT AND VARIABLE OVERNIGHT AS HIGH PRESSURE MOVES OVER
THE AREA. WILL HAVE TO WATCH FOR SOME PATCHY GROUND FOG FORMATION
TOWARDS MORNING BUT DO NOT THINK AT THIS POINT WILL BE WIDESPREAD SO
DID NOT INCLUDE IN TAFS. CLOUDS WILL BEGIN TO INCREASE IN THE WEST
AND SOUTH WINDS BEGIN TO INCREASE LATE IN THE PERIOD AS THE NEXT
SYSTEM APPROACHES BUT THINK ANY RESTRICTIONS TO CIGS AND VIS WILL BE
AFTER THE TAF PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
SHORT TERM...SPEICHER
LONG TERM...JR/SPEICHER
AVIATION...JR
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1234 PM CST WED NOV 26 2014
.UPDATE...
HOURLY OBS CONTINUE TO SHOW STEEPER WARMING TREND THAN FORECAST
AND WITH 70S ALREADY BEING OBSERVED ALONG I35 CORRIDOR...WENT
AHEAD AND RAISED THE MAX T GRID. RUC MODEL SEEMED TO DECENTLY
DEPICT MID 70S ACROSS THE AREA THIS AFTERNOON SO WENT WITH THAT
FOR THE MOST PART. CONTINUING TO CLOSELY MONITOR WINDS ON THE
EDWARDS PLATEAU AS DEWS IN THE TEENS ARE BEING SEEN THERE
RESULTING IN VERY LOW RH VALUES.
TB3
&&
.PREV DISCUSSION... /ISSUED 1137 AM CST WED NOV 26 2014/
UPDATE...
PLEASE SEE 18Z AVIATION DISCUSSION BELOW.
AVIATION...
VFR SKC CONDITIONS PREVAIL ACROSS THE REGION CURRENTLY AND
EXPECTED TO CONTINUE THROUGH THE PERIOD. SUSTAINED SURFACE WINDS
WILL BE W/SW NEAR 10-15 KT WITH HIGHER GUSTS POSSIBLE TOWARDS 20
KT FOR KAUS WITH KSAT/KSSF SLIGHTLY LESS THROUGH EARLY AFTERNOON.
WINDS WILL DECREASE BY THE LATE AFTERNOON BUT PIVOT TO THE NORTH
THROUGH THE EVENING AS A WEAK COOL FRONT MOVES THROUGH. /ALLEN/
PREV DISCUSSION... /ISSUED 1017 AM CST WED NOV 26 2014/
UPDATE...
AT 16Z...SKIES WERE CLEAR WITH WINDS GENERALLY OUT OF THE WEST
FROM 5-15MPH. WILL CONTINUE TO KEEP AN EYE ON THE NORTHERN RIO
GRANDE VALLEY AS RH VALUES SHOULD DROP INTO THE TEENS OUT THERE.
HOURLY T GRIDS WERE A BIT SLOW TO WARM THIS MORNING SO MADE SOME
ADJUSTMENTS TO COMPENSATE. MAY NEED TO RAISE MAX T A COUPLE
DEGREES IF THAT TREND CONTINUES.
OTHERWISE...FORECAST IS ON TRACK.
PREV DISCUSSION... /ISSUED 347 AM CST WED NOV 26 2014/
SHORT TERM (TODAY THROUGH THURSDAY)...
AN UPPER LEVEL TROUGH MOVING EAST THROUGH THE EASTERN PLAINS TO
THE LOWER OHIO VALLEY WILL SEND A COLD FRONT SOUTH INTO SOUTH
CENTRAL TEXAS LATE THIS AFTERNOON INTO TONIGHT. AHEAD OF THE
FRONT...SOUTHWESTERLY WINDS WILL CONTINUE THE WARMING TREND WITH
TEMPERATURES SLIGHTLY ABOVE AVERAGE TODAY. IN THE WAKE OF THE
FRONT...COOLER...AND SLIGHTLY BELOW AVERAGE TEMPERATURES ARE
EXPECTED ON THANKSGIVING DAY.
LONG TERM (THURSDAY NIGHT THROUGH TUESDAY)...
THE SURFACE HIGH MOVES OFF TO THE EAST THURSDAY NIGHT INTO FRIDAY.
SOUTHERLY FLOW RETURNS WITH INCREASING LOWER LEVEL MOISTURE AND A
WARMING TREND FOR THE REMAINDER OF THE THANKSGIVING WEEKEND. A DRY
ZONAL FLOW FLOW ALOFT WILL PREVAIL. SOME LOW CLOUDS RETURN FRIDAY
MORNING WITH A BETTER CHANCE SATURDAY MORNING. A WEAK UPPER LEVEL
TROUGH MOVING ACROSS SOUTHERN TEXAS AND THE LOW LEVEL JET MAY LIFT
A SOMEWHAT DEEPER LOWER LEVEL MOIST LAYER TO GENERATE ISOLATED
SHOWERS ACROSS FAR EASTERN AREAS SUNDAY INTO SUNDAY NIGHT. MODELS
THEN DIFFER IN THE LOWER LEVELS FOR MONDAY INTO TUESDAY WHILE ALL
KEEP A ZONAL FLOW ALOFT. A COUPLE OF UPPER LEVEL TROUGHS MOVING
EAST ACROSS THE NORTHERN TIER OF STATES AND SOUTHERN CANADA FORCE
A RATHER STRONG COLD FRONT SOUTH ACROSS THE PLAINS. THE ECMWF AND
GEM SHOW A STRONGER COLD FRONTAL PUSH ACROSS SOUTH CENTRAL TEXAS
ON MONDAY WHILE THE GFS HAS A WEAKER FRONTAL PUSH AND THE NAVGEM
KEEPS THE FRONT NORTH. THE GFS HAS BEEN MORE CONSISTENT AND WILL
FAVOR THAT MODEL...ESPECIALLY WITH A ZONAL FLOW ALOFT SLOWING THE
SOUTHWARD PROGRESS OF THE FRONT AND ERODING THE COLD AIRMASS ON
ITS SOUTHERN END. THE FRONT STALLS OVER SOUTHERN TEXAS MONDAY
NIGHT AND THEN MOVES BACK NORTH TUESDAY. THE LOW LEVEL JET AND THE
FRONT MAY GENERATE ISOLATED SHOWERS ACROSS EASTERN AREAS MONDAY.
ISENTROPIC LIFT OVER THE FRONT MAY GENERATE ISOLATED SHOWERS
ACROSS EASTERN INTO CENTRAL AREAS TUESDAY. TOTAL RAINFALL AMOUNTS
WILL BE LIGHT...GENERALLY LESS THAN 1/10 INCH FOR SUNDAY THROUGH
TUESDAY. COOLER TEMPERATURES ARE EXPECTED BY TUESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 41 65 44 71 55 / 0 0 0 - -
AUSTIN BERGSTROM INTL AIRPORT 37 64 41 72 53 / 0 0 0 - -
NEW BRAUNFELS MUNI AIRPORT 40 66 44 71 53 / 0 0 0 0 -
BURNET MUNI AIRPORT 38 62 42 69 49 / 0 0 0 0 -
DEL RIO INTL AIRPORT 39 66 44 70 46 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 37 63 43 70 54 / 0 0 0 - -
HONDO MUNI AIRPORT 37 66 42 72 48 / 0 0 0 0 -
SAN MARCOS MUNI AIRPORT 39 65 43 71 53 / 0 0 0 0 -
LA GRANGE - FAYETTE REGIONAL 41 65 45 71 56 / 0 0 0 - -
SAN ANTONIO INTL AIRPORT 42 66 47 72 54 / 0 0 0 0 -
STINSON MUNI AIRPORT 42 67 46 73 53 / 0 0 0 0 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...15
SYNOPTIC/GRIDS...03
PUBLIC SERVICE/DATA COLLECTION...32
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
352 PM CST WED NOV 26 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 351 PM CST WED NOV 26 2014
AT 3 PM...A SURFACE LOW WAS LOCATED OVER NORTHEAST MISSOURI.
AN INVERTED TROUGH EXTENDS NORTH NORTHWEST OF THIS LOW THROUGH
CENTRAL IOWA INTO SOUTH CENTRAL MINNESOTA. FURTHER NORTHWEST AN
ARCTIC COLD FRONT EXTENDED FROM THE WESTERN TIP OF LAKE SUPERIOR
SOUTHEAST TO SIOUX FALLS SOUTH DAKOTA. TEMPERATURES AHEAD OF THIS
COLD FRONT WERE IN THE MID AND UPPER 20S. MEANWHILE IN THE WAKE OF
THIS FRONT...TEMPERATURES RANGED FROM 0 TO THE LOWER 20S. THE
COMBINATION OF LIFT ASSOCIATED WITH THE TROUGH AND THE COLD FRONT
PRODUCED SNOW ACROSS MUCH OF SOUTH CENTRAL AND SOUTHEAST MINNESOTA
AND EASTERN IOWA. THE HIGHEST SNOW TOTAL /MAINLY DUE TO THE AXIS
PIVOTING ACROSS THIS AREA FOR A LONG DURATION/ WAS 11 INCHES
8 MILES WEST OF FARIBAULT. OUR HIGHEST TOTAL IS 3.8 INCHES IN
MANTORVILLE MINNESOTA /DODGE COUNTY/.
FOR TONIGHT...THE 26.12Z MODELS ARE IN GOOD AGREEMENT THAT THE
TROUGH WILL CONTINUE TO PULL SOUTH AWAY FROM THE AREA AND TAKE
WITH IT THE INVERTED TROUGH WITH IT. THEY ALSO SHOW THAT THE
ARCTIC COLD FRONT WILL MOVE SOUTHEAST THROUGH THE AREA. THIS FRONT
WILL LIKELY EXTEND FROM WISCONSIN RAPIDS TO OELWEIN IOWA AROUND
MIDNIGHT AND WILL BE SOUTH OF THE FORECAST AREA BY 3 AM. THE
MODELS SHOW THAT THAT THE 900 TO 700 FRONTOGENESIS WILL QUICKLY
WEAKEN ACROSS THE AREA THIS EVENING. AS A RESULT...WENT WITH A
RAPIDLY DIMINISHING TREND IN THE SNOW. ADDITIONAL TOTALS WILL BE
UP TO AN INCH IN NORTHEAST IOWA AND SOUTHEAST MINNESOTA...AND FROM
A TRACE TO A HALF INCH IN WESTERN WISCONSIN. WITH IT STILL
SNOWING...WILL JUST LET THE WINTER WEATHER ADVISORY CONTINUE
THROUGH 6 PM.
WITH STRONG COLD AIR ADVECTION IN THE WAKE OF THIS FRONT...EXPECT
HIGH TEMPERATURES FOR THANKSGIVING TO OCCUR BETWEEN MIDNIGHT AND
3 AM TONIGHT. NAEFS STANDARD 850 MB TEMPERATURE ANOMALIES ARE
RUNNING AROUND 2 STANDARD DEVIATIONS BELOW NORMAL. AS A
RESULT...EXPECT HIGH TEMPERATURES TO RANGE FROM NEAR 10 TO 25.
THIS WILL BE THE COLDEST THANKSGIVING IN SOUTHEAST MINNESOTA AND
NORTHEAST IOWA SINCE 1985...AND THE COLDEST IN WESTERN WISCONSIN
SINCE 1958. MORE ON THIS CAN BE FOUND IN THE CLIMATE SECTION OF
THIS PRODUCT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 351 PM CST WED NOV 26 2014
ON THURSDAY NIGHT AND FRIDAY...MODERATE TO STRONG 925 TO 700 MB
WARM AIR ADVECTION WILL DEVELOP ACROSS THE AREA AS A SHORT WAVE
TROUGH MOVES EAST ACROSS NORTHERN MINNESOTA. IT CONTINUES TO LOOK
LIKE THIS SYSTEM WILL PRODUCE BETWEEN 1.5 AND 3 INCHES ALONG AND
NORTH OF INTERSTATE 94...AND FROM A TRACE TO 1.5 INCHES SOUTH OF
THIS INTERSTATE. SOUNDINGS CONTINUE TO SHOW THAT DRY AIR ABOVE
850 MB WILL MOVE NORTHEAST INTO THE AREA FROM THE CENTRAL PLAINS
ON FRIDAY. THIS DRY AIR WILL SHUTOFF ICE CRYSTAL SEEDING FROM
ALOFT. HOWEVER THERE APPEARS TO BE A DEEP ENOUGH COLD LAYER NEAR
THE SURFACE THAT SOME SNOW COULD STILL DEVELOP INITIALLY...AND
THEN AS THIS LAYER WARMS UP THIS PRECIPITATION COULD POTENTIALLY
SHIFT OVER TO SOME LIGHT FREEZING DRIZZLE...BUT A BIT CONCERNED
THAT BY THIS TIME THERE MAY BE ENOUGH DRY IN THE LOW LEVELS TO
PRECLUDE THIS FROM HAPPENING.
ON FRIDAY NIGHT...THE NAM DEVELOPS FREEZING RAIN NEAR THE
INTERSTATE 90 CORRIDOR. MEANWHILE THE OTHER DETERMINISTIC MODELS
HAVE THE AREA DRY...SO TRENDED THE FORECAST TOWARD THEM. ANOTHER
ISSUE ON FRIDAY NIGHT IS THAT THE LOW TEMPERATURES LOOK TOO COLD
CONSIDERING SOUTHWEST WIND OF 10 TO 15 MPH AND THE MODELS LOOKING
LIKE THEY HAVE TOO MUCH SNOW INITIALIZED IN THEM. THE NAM IN
PARTICULAR IS ABOUT 2 TO 3 INCHES TOO HIGH WITH ITS SNOW DEPTH
ALREADY. DUE TO THIS...RAISED THEM A FEW DEGREES AND ALSO RAISED
SATURDAY MAXIMUM TEMPERATURES TOO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1130 AM CST WED NOV 26 2014
SNOW HAS BEEN FALLING AT RST FOR THE PAST FEW HOURS AND WILL
CONTINUE AT THIS INTENSITY THROUGH THE EARLY HALF OF THE AFTERNOON
WITH VISIBILITY STAYING DOWN BETWEEN 3/4-2SM. THIS SNOW IS
EXPECTED TO MAKE IT INTO LSE AROUND 21Z OR SO...BUT LIKELY WILL
NOT BE AS INTENSE AT 2SM OR HIGHER. CONDITIONS WILL IMPROVE LATER
THIS AFTERNOON AND EVENING AFTER THE COLD FRONT MOVES IN AND
BRINGS DRIER AIR DOWN FROM THE NORTH. SOME MVFR CEILINGS WILL
LIKELY HOLD ON THROUGH THE NIGHT BEFORE SCATTERING OUT TOMORROW
MORNING AS A RIDGE OF HIGH PRESSURE MOVES IN FROM THE WEST.
&&
.CLIMATE...THANKSGIVING
ISSUED AT 351 PM CST WED NOV 26 2014
WITH A HIGH TEMPERATURE NEAR 10 DEGREES...ROCHESTER MINNESOTA WILL
BE WITHIN THE TOP 5 FOR THEIR COLDEST THANKSGIVING HIGH
TEMPERATURE. THEY ARE...
1/ 7F 1930
2/ 12F 1985
3/ 14F 1952
4/ 14F 1886
5/ 17F 1956
17F 1919
IT WILL BE ONLY THE 10TH TIME THAT ROCHESTER HAS BEEN 19 DEGREES
OR COLDER ON THANKSGIVING. THE LAST TIME IT OCCURRED WAS 1985.
IN LA CROSSE WISCONSIN...THERE IS STILL SOME QUESTION ON WHETHER
THE HIGH FOR THE DAY WILL BE IN THE TEENS OR NOT. AT MIDNIGHT...THE
HRRR...NAM...SREF...AND RAP HAVE THE HIGH TEMPERATURE BETWEEN 20
AND 22F. MEANWHILE BOTH THE GFS AND ECMWF...HAS A MIDNIGHT HIGH
OF 18F. THIS WOULD PLACE THIS THANKSGIVING IN THE 9 TO 15 RANK.
THEY ARE...
7/ 17F 1919
17F 1952
9/ 19F 1958
19F 1956
19F 1952
12/ 20F 1938
20F 1905
20F 1881
15/ 21F 1903
16/ 23F 1877
THE COLDEST IS 4 DEGREES IN 1872. OUR TEMPERATURE RECORDS FOR
LA CROSSE STARTED JUST OVER A MONTH BEFORE THIS RECORD WAS SET ON
OCTOBER 15 1872. IF WE ARE IN THE TEENS FOR A HIGH TEMPERATURE IT
WILL ONLY BE THE 11TH TIME THAT THIS HAS OCCURRED. IT WILL
DEFINITELY BE THE COLDEST THANKSGIVING AS FAR AS HIGH TEMPERATURE
SINCE 1958 /19F/.
ALSO THIS COULD POTENTIALLY BE THE 21ST CONSECUTIVE THANKSGIVING
WITHOUT MEASURABLE PRECIPITATION IN LA CROSSE. THIS STRETCH IS THE
LONGEST. PRIOR TO THIS STRETCH...THE RECORD WAS 6 YEARS /1900-1905
1909-14 AND 1986-91/.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ086-
094.
IA...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ008-
018-019.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...HALBACH
CLIMATE...BOYNE