Forecast Discussions mentioning any of "HRRR" "RR" "RUC13" "RUC" received at GSD on 12/23/11

AREA FORECAST DISCUSSION

NWS DENVER CO

 901 AM MST WED DEC 21 2011

.UPDATE...STRONG TROUGH IS CURRENTLY OVER SOUTHWEST MONTANA WILL
CONTINUE TO DIG SOUTH TODAY. A SOUTHWEST JET AHEAD OF THIS TROUGH IS
PRODUCING AN AREA OF LIGHT SNOW FROM NORTH CENTRAL COLORADO TO
SOUTHERN WYOMING. THIS AREA OF SNOW WILL SINK SOUTH THROUGH THE DAY
AS THE SYSTEM MOVES SOUTH. MODELS SHOWING THIS WILL WEAKEN AS IT
MOVE INTO COLORADO. SO IF ANY SNOW FALL IT WILL BE LIGHT. WILL ADD
SOME LOW POPS TO THE FORECAST TO COVER THIS. MAIN STORM IS STILL
OVER SOUTHERN MONTANA AND NORTHERN WYOMING. WIDESPREAD SNOW IS ON
TRACK TO START THIS EVENING. BEST LIFT AND STRONGEST UPSLOPE WILL
OCCUR AFTER MIDNIGHT...THUS THE HEAVIEST SNOW WILL FALL DURING THIS
TIME FRAME.

CURRENT WINTER WEATHER HIGHLIGHTS LOOK ON TRACK...WILL ADD THE
MOUNTAIN VALLEYS TO THE ADVISORY WHERE IT APPEARS 3 TO 6 INCHES WILL
FALL. ONLY OTHER CHANGE TO THE FORECAST WILL BE TO ADD A COUPLE OF
INCHES OF SNOW TO THE WINTER STORM WARNING. MODELS HAVE BEEN
CONSISTENT IN FORECASTING 0.40 TO 0.75 INCHES OF LIQUID WITH THIS
STORM FOR THE URBAN CORRIDOR. USING A 15 TO 1 RATIO...THIS WOULD
LEAD TO ABOUT 6 TO 11 INCHES. WOULD EXPECT A LITTLE MORE ACROSS
FAVORED UPSLOPE AREAS IN AND NEAR THE FOOTHILLS.

&&

.AVIATION...HIGH CLOUDS WILL INCREASE TODAY AS THE WINTER STORM
NEARS THE COLORADO. CEILINGS WILL REMAIN ABOVE 10000 THROUGH 21Z
THEN FALL THROUGH THE AFTERNOON AND EVENING. CEILINGS AND
VISIBILITIES SHOULD TANK FAIRLY RAPIDLY DURING THE 00Z TO 03Z TIME
FRAME WITH SNOW AND REMAIN DOWN THROUGH THE NIGHT. WINDS WILL
TRANSITION TO LIGHT NORTH/NORTHEAST DURING THE AFTERNOON WITH A
GRADUAL INCREASE INTO THE EVENING HOURS. SUSTAINED SPEEDS IN THE 10
TO 15 KNOT RANGE SHOULD BE COMMON AFTER ABOUT 00Z...CONTINUING
THROUGH 12Z WITH GUSTS TO THE LOWER 20S...STRONGEST AT KDEN.
HEAVIEST SNOW WILL OCCUR 06-12Z. EXPECTING SNOW ACCUMULATION AT
KDEN TO BE 6-8 INCHES...WITH 7-10 INCHES POSSIBLE AT KAPA AND
KBJC.

&&

.PREV DISCUSSION... /ISSUED 427 AM MST WED DEC 21 2011/

SHORT TERM...FORECAST IN PRETTY GOOD SHAPE AND MODELS IN GOOD
AGREEMENT WITH THE UPCOMING STORM. VERY WEAK QG ASCENT IS ALREADY
UNDERWAY OVER THE CWA PER LATEST RUC ANALYSES AND IT WILL BE ON
THE INCREASE THROUGHOUT THE SHORT TERM.  THE HEART OF IT IS OVER
CENTRAL COLORADO BY 12Z THURSDAY WITH AT LEAST MODEST VALUES
THROUGHOUT THE ENTIRE CWA BY THEN.  AT THE SURFACE UPSLOPE WILL
ALSO BE INCREASING THROUGH THE PERIOD WITH SOME MINOR AND PROBABLY
NOT TERRIBLY SIGNIFICANT TIMING DIFFERENCES AMONGST THE MODELS.
CONTRARY TO SOME OF THE EARLIER STORMS THIS YEAR A DECENT QG
ANALLOBARIC CENTER IS FORECAST TO DEVELOP OVER THE AREA BY 12Z
WHICH MAY ENHANCE THE UPSLOPE INTO THE FRONT RANGE AND AID IN
SNOWFALL IN AND NEAR THE FOOTHILLS. ALL IN ALL THIS LOOKS TO BE A
FAIRLY TYPICAL EARLY WINTER STORM FOR NORTHEAST AND NORTH CENTRAL
COLORADO.

LONG TERM...AN UPPER LEVEL LOW WILL BE OVER SWRN CO THU MORNING AND
WILL MOVE SLOWLY SSE INTO NWRN NEW MEXICO BY THU NIGHT.
CROSS-SECTIONS SHOW FAVORABLE UPSLOPE FLOW AND DECENT QG ASCENT THRU
18Z WITH A GRADUAL WEAKENING IN BOTH UPSLOPE FLOW AND QG ASCENT
DURING THE AFTN HOURS.  THUS SHOULD SEE PERIODS OF MDT TO HEAVY SNOW
IN THE FOOTHILLS AND ERN FACING SLOPES OF THE MTNS.  AT LOWER
ELEVATIONS APPEARS BEST CHC OF HEAVY SNOWS WILL BE FM BOULDER TO
DENVER SOUTHWARD ACROSS THE PALMER DIVIDE SO WILL CONTINUE WITH A
WARNING IN THESE AREAS THRU 18Z.  FURTHER NORTH CLOSER TO TO THE
CO-WY BORDER APPEARS SNOW AMOUNTS WILL NOT BE QUITE AS HEAVY SO WILL
HAVE AN ADVISORY IN THOSE AREAS THRU 18Z.  OVER THE PLAINS WILL HAVE
ADVISORIES FM EAST OF DENVER TO LIMON THRU MIDDAY.  WINDS WILL BE
GUSTY IN THE MORNING AS WELL ESPECIALLY ALONG AND EAST OF I-25 SO
WILL SEE SOME BLOWING SNOW AND POOR VISIBILITIES AS WELL.

BY AFTN SHOULD SEE SNOWFALL GRADUALLY DECREASE FM NORTH TO SOUTH
ALTHOUGH ACROSS THE SRN FOOTHILLS AND PALMER DIVIDE ITS POSSIBLE MDT
SNOWFALL MAY LINGER THRU THE LATE AFTN HOURS.  AS FOR TOTAL AMOUNTS
WILL HAVE 6 TO 12 INCHES IN THE MTNS...8 TO 16 INCHES IN THE
FOOTHILLS...5 TO 10 INCHES FM DENVER SOUTH TO THE PALMER DIVIDE WITH
3 TO 6 INCHES NEAR THE CO-WY BORDER.  OVER THE PLAINS AMOUNTS WILL
RANGE FROM 2 TO 4 INCHES OVER THE FAR NERN CORNER WITH 3 TO 6 INCHES
ELSEWHERE.  HIGHS ON THU WILL STRUGGLE TO GET ABOVE 20 DEGREES OVER
MUCH OF NERN CO AS COLD SFC HIGH PRESSURE BUILDS SOUTHWARD INTO THE
AREA.

FOR THU NIGHT INTO FRI THE STORM SYSTEM WILL CONTINUE TO MOVE SE
AWAY FM THE AREA WITH SNOW ENDING IN ALL AREAS BY EARLY THU
EVENING.  CLEARING SKIES THU NIGHT COMBINED WITH FRESH SNOW COVER
MAY ALLOW FOR LOWS TO DROP BLO ZERO ACROSS MUCH OF NERN CO BY FRI
MORNING.  ON FRI DRY NNE MID LEVEL FLOW WILL BE OVER THE AREA WITH
MO PCPN EXPECTED.  HIGHS ON FRI WILL LIKELY BE AFFECTED BY SNOW
COVER OVER NERN CO AS INVERSIONS WILL HAVE A HARD TIME BREAKING SO
WILL KEEP HIGHS IN THE 25 TO 30 DEGREE RANGE.

FOR SAT LOOKS LIKE A WEAK WEATHER DISTURBANCE MAY TRACK ACROSS NRN
CO HOWEVER CROSS-SECTIONS SHOW VERY LITTLE MOISTURE WITH THIS
FEATURE SO WILL ONLY MENTION A SLIGHT CHC OF SNOW IN THE MTNS NORTH
OF -70.  AS FOR HIGHS LATEST GFS IS REALLY STARTING TO WRM TEMPS
HOWEVER BELIEVE LINGERING SNOW PACK COMBINED WITH LACK OF DOWNSLOPE
COMPONENT WILL PROBABLY KEEP HIGHS IN THE 30S ACROSS NERN CO INSTEAD
OF THE 40S AS SHOWN BY THE GFS.  BY CHRISTMAS AN UPPER LEVEL RIDGE
WILL BE OVER THE AREA WITH CROSS-SECTIONS SHOWING A DRY AIRMASS IN
PLACE SO WILL KEEP FCST DRY.  ONCE AGAIN LATEST GFS IS SHOWING QUITE
A BIT OF WARMING ON SUN WITH HIGHS IN THE 50S ACROSS NERN CO AS LOW
LEVEL WINDS ARE FCST TO BECOME WEAK SWLY.  FOR NOW WILL KEEP
READINGS IN THE UPPER 30S TO MID 40S DUE TO LINGERING SNOW COVER.

FOR MON THE FLOW ALOFT WILL INCREASE AND BECOME MORE WLY WHICH
SHOULD ALLOW FOR BETTER DOWNSLOPE WARMING AND ALLOW HIGHS TO RISE
WELLS INTO 40S.  WITH THE INCREASING FLOW ALOFT WINDS WILL BECOME
GUSTY IN THE MTNS AND FOOTHILLS.  BY TUE THE ECMWF AND GFS DIVERGE
SOMEWHAT AS THE GFS HAS MAINLY DRY WNW FLOW ALOFT WHILE THE ECMWF
SHOWS AN UPPER LEVEL ROUGH MOVING QUICKLY ACROSS THE AREA WITH A CHC
OF SNOW IN THE MTNS.

AVIATION...VFR CONDITIONS ARE EXPECTED THROUGH AT LEAST EARLY
AFTERNOON WITH A THREAT OF SCT-BKN060 BY MID AFTERNOON. CEILINGS
AND VISIBILITIES SHOULD TANK FAIRLY RAPIDLY DURING THE 00Z TO 03Z
TIME FRAME WITH SNOW AND REMAIN DOWN THROUGH THE NIGHT. WINDS WILL
TRANSITION TO LIGHT NORTH/NORTHEAST DURING THE DAY WITH A GRADUAL
INCREASE INTO THE EVENING HOURS.  SUSTAINED SPEEDS IN THE 10 TO 15
KNOT RANGE SHOULD BE COMMON AFTER ABOUT 00Z...CONTINUING THROUGH
12Z WITH GUSTS TO THE LOWER 20S...STRONGEST AT KDEN. THE WIND WILL
CAUSE SOME BLOWING SNOW AS WELL.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM MST
THURSDAY FOR COZ030>034-037-038-042>046.

WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 11 AM MST
THURSDAY FOR COZ035-036-039>041.

&&

$$

SHORT TERM...RPK
LONG TERM....ET
UPDATE/AVIATION...MEIER






AREA FORECAST DISCUSSION

NWS DENVER CO

 427 AM MST WED DEC 21 2011

.SHORT TERM...FORECAST IN PRETTY GOOD SHAPE AND MODELS IN GOOD
AGREEMENT WITH THE UPCOMING STORM. VERY WEAK QG ASCENT IS ALREADY
UNDERWAY OVER THE CWA PER LATEST RUC ANALYSES AND IT WILL BE ON
THE INCREASE THROUGHOUT THE SHORT TERM.  THE HEART OF IT IS OVER
CENTRAL COLORADO BY 12Z THURSDAY WITH AT LEAST MODEST VALUES
THROUGHOUT THE ENTIRE CWA BY THEN.  AT THE SURFACE UPSLOPE WILL
ALSO BE INCREASING THROUGH THE PERIOD WITH SOME MINOR AND PROBABLY
NOT TERRIBLY SIGNIFICANT TIMING DIFFERENCES AMONGST THE MODELS.
CONTRARY TO SOME OF THE EARLIER STORMS THIS YEAR A DECENT QG
ANALLOBARIC CENTER IS FORECAST TO DEVELOP OVER THE AREA BY 12Z
WHICH MAY ENHANCE THE UPSLOPE INTO THE FRONT RANGE AND AID IN
SNOWFALL IN AND NEAR THE FOOTHILLS. ALL IN ALL THIS LOOKS TO BE A
FAIRLY TYPICAL EARLY WINTER STORM FOR NORTHEAST AND NORTH CENTRAL
COLORADO.

.LONG TERM...AN UPPER LEVEL LOW WILL BE OVER SWRN CO THU MORNING AND
WILL MOVE SLOWLY SSE INTO NWRN NEW MEXICO BY THU NIGHT.
CROSS-SECTIONS SHOW FAVORABLE UPSLOPE FLOW AND DECENT QG ASCENT THRU
18Z WITH A GRADUAL WEAKENING IN BOTH UPSLOPE FLOW AND QG ASCENT
DURING THE AFTN HOURS.  THUS SHOULD SEE PERIODS OF MDT TO HEAVY SNOW
IN THE FOOTHILLS AND ERN FACING SLOPES OF THE MTNS.  AT LOWER
ELEVATIONS APPEARS BEST CHC OF HEAVY SNOWS WILL BE FM BOULDER TO
DENVER SOUTHWARD ACROSS THE PALMER DIVIDE SO WILL CONTINUE WITH A
WARNING IN THESE AREAS THRU 18Z.  FURTHER NORTH CLOSER TO TO THE
CO-WY BORDER APPEARS SNOW AMOUNTS WILL NOT BE QUITE AS HEAVY SO WILL
HAVE AN ADVISORY IN THOSE AREAS THRU 18Z.  OVER THE PLAINS WILL HAVE
ADVISORIES FM EAST OF DENVER TO LIMON THRU MIDDAY.  WINDS WILL BE
GUSTY IN THE MORNING AS WELL ESPECIALLY ALONG AND EAST OF I-25 SO
WILL SEE SOME BLOWING SNOW AND POOR VISIBILITIES AS WELL.

BY AFTN SHOULD SEE SNOWFALL GRADUALLY DECREASE FM NORTH TO SOUTH
ALTHOUGH ACROSS THE SRN FOOTHILLS AND PALMER DIVIDE ITS POSSIBLE MDT
SNOWFALL MAY LINGER THRU THE LATE AFTN HOURS.  AS FOR TOTAL AMOUNTS
WILL HAVE 6 TO 12 INCHES IN THE MTNS...8 TO 16 INCHES IN THE
FOOTHILLS...5 TO 10 INCHES FM DENVER SOUTH TO THE PALMER DIVIDE WITH
3 TO 6 INCHES NEAR THE CO-WY BORDER.  OVER THE PLAINS AMOUNTS WILL
RANGE FROM 2 TO 4 INCHES OVER THE FAR NERN CORNER WITH 3 TO 6 INCHES
ELSEWHERE.  HIGHS ON THU WILL STRUGGLE TO GET ABVE 20 DEGREES OVER
MUCH OF NERN CO AS COLD SFC HIGH PRESSURE BUILDS SOUTHWARD INTO THE
AREA.

FOR THU NIGHT INTO FRI THE STORM SYSTEM WILL CONTINUE TO MOVE SE
AWAY FM THE AREA WITH SNOW ENDING IN ALL AREAS BY EARLY THU
EVENING.  CLEARING SKIES THU NIGHT COMBINED WITH FRESH SNOW COVER
MAY ALLOW FOR LOWS TO DROP BLO ZERO ACROSS MUCH OF NERN CO BY FRI
MORNING.  ON FRI DRY NNE MID LEVEL FLOW WILL BE OVER THE AREA WITH
MO PCPN EXPECTED.  HIGHS ON FRI WILL LIKELY BE AFFECTED BY SNOW
COVER OVER NERN CO AS INVERSIONS WILL HAVE A HARD TIME BREAKING SO
WILL KEEP HIGHS IN THE 25 TO 30 DEGREE RANGE.

FOR SAT LOOKS LIKE A WEAK WEATHER DISTURBANCE MAY TRACK ACROSS NRN
CO HOWEVER CROSS-SECTIONS SHOW VERY LITTLE MOISTURE WITH THIS
FEATURE SO WILL ONLY MENTION A SLIGHT CHC OF SNOW IN THE MTNS NORTH
OF -70.  AS FOR HIGHS LATEST GFS IS REALLY STARTING TO WRM TEMPS
HOWEVER BELIEVE LINGERNG SNOW PACK COMBINED WITH LACK OF DOWNSLOPE
COMPONENT WILL PROBABLY KEEP HIGHS IN THE 30S ACROSS NERN CO INSTEAD
OF THE 40S AS SHOWN BY THE GFS.  BY CHRISTMAS AN UPPER LEVEL RIDGE
WILL BE OVER THE AREA WITH CROSS-SECTIONS SHOWING A DRY AIRMASS IN
PLACE SO WILL KEEP FCST DRY.  ONCE AGAIN LATEST GFS IS SHOWING QUITE
A BIT OF WARMING ON SUN WITH HIGHS IN THE 50S ACROSS NERN CO AS LOW
LEVEL WINDS ARE FCST TO BECOME WEAK SWLY.  FOR NOW WILL KEEP
READINGS IN THE UPPER 30S TO MID 40S DUE TO LINGERING SNOW COVER.

FOR MON THE FLOW ALOFT WILL INCREASE AND BECOME MORE WLY WHICH
SHOULD ALLOW FOR BETTER DOWNSLOPE WARMING AND ALLOW HIGHS TO RISE
WELLS INTO 40S.  WITH THE INCREASING FLOW ALOFT WINDS WILL BECOME
GUSTY IN THE MTNS AND FOOTHILLS.  BY TUE THE ECMWF AND GFS DIVERGE
SOMEWHAT AS THE GFS HAS MAINLY DRY WNW FLOW ALOFT WHILE THE ECMWF
SHOWS AN UPPER LEVEL ROUGH MOVING QUICKLY ACROSS THE AREA WITH A CHC
OF SNOW IN THE MTNS.

&&

.AVIATION...VFR CONDITIONS ARE EXPECTED THROUGH AT LEAST EARLY
AFTERNOON WITH A THREAT OF SCT-BKN060 BY MID AFTERNOON. CEILINGS
AND VISIBILITIES SHOULD TANK FAIRLY RAPIDLY DURING THE 00Z TO 03Z
TIME FRAME WITH SNOW AND REMAIN DOWN THROUGH THE NIGHT. WINDS WILL
TRANSITION TO LIGHT NORTH/NORTHEAST DURING THE DAY WITH A GRADUAL
INCREASE INTO THE EVENING HOURS.  SUSTAINED SPEEDS IN THE 10 TO 15
KNOT RANGE SHOULD BE COMMON AFTER ABOUT 00Z...CONTINUING THROUGH
12Z WITH GUSTS TO THE LOWER 20S...STRONGEST AT KDEN. THE WIND WILL
CAUSE SOME BLOWING SNOW AS WELL.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 11 AM MST
THURSDAY FOR COZ031-033-034-037-038-042>046.

WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 11 AM MST
THURSDAY FOR COZ035-036-039>041.

&&

$$

SHORT TERM...ET
LONG TERM....RPK
AVIATION...ET






















AREA FORECAST DISCUSSION

NWS TAUNTON MA

 700 PM EST THU DEC 22 2011

.SYNOPSIS...
LOW PRESSURE NEAR ATLANTA WILL PASS SOUTH OF NEW ENGLAND FRIDAY.
HIGH PRESSURE THEN BUILDS OVER THE REGION ON SATURDAY AND MOVES
OFFSHORE SUNDAY. A STORM WILL DEVELOP WELL EAST OF NEW ENGLAND
MONDAY THEN HIGH PRESSURE WILL BUILD INTO THE REGION TUESDAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
7PM UPDATE...
MINOR TWEAKS TO THE FCST THIS EVENING. SLOWED PROGRESSION OF
PRECIP 00Z TO 06Z PER LATEST HRRR. AVAILABLE LAPS SOUNDINGS SHOW A
FAIR AMOUNT OF DRY AIR TO OVERCOME WITH WEAK RIDGING IN PLACE
WHICH IS REASONABLE GIVEN DWPT DEPRESSIONS CURRENTLY OBSERVED.
THIS GAVE MORE CONFIDENCE IN HRRR TIMING. OTHERWISE...ADJUSTED
TEMPS AND DWPTS TOWARD CURRENT TRENDS...WHICH IS GENERALLY WARMER
THAN PREVIOUS FORECAST...A FACT THAT WILL NEED TO BE MONITORED
OVERNIGHT FOR REGARDING MIXED PRECIP POTENTIAL.

PREVIOUS DISCUSSION...
UPDATED TO CORRECT ADVISORY CODING. THERE IS NO ADVISORY IN NEW
HAMPSHIRE.

CLOUDS MOVING INTO NEW ENGLAND FROM THE WEST...THIS CLOUD AREA
COVERS MUCH OF NEW YORK AND NORTHERN PA AND THE OHIO VALLEY.
EXPECT THESE CLOUDS TO FIRMLY ESTABLISH OVER NEW ENGLAND THIS
EVENING.

ALL MODELS SIMILAR IN MOVING SOUTHEAST USA LOW PRESSURE SOUTH OF
NEW ENGLAND. CONSENSUS TRACK PASSES JUST INSIDE OF THE BENCHMARK
FRIDAY MORNING. ISENTROPIC LIFT REACHES WESTERN SECTIONS BY 06Z
AND MOVES ACROSS THE FORECAST AREA DURING THE LATE NIGHT. CROSS
SECTIONS SHOW DEEP MOIST LIFT WITH STRONGEST LIFT IN THE -10C TO
-15C LAYER BUT PROGRESSIVELY MIGRATING LOWER/WARMER BY SUNRISE.
START TIMING LOOKS TO BE 05Z-08Z WITH BEST LIFT AND PRECIP RATE
LATE.

TREND OF ALL MODELS IS TOWARD A WARMER SOLUTION WITH KEY THICKNESS
VALUES DISPLACED FARTHER NORTH. WHILE THIS DOESN/T COMPLETELY RULE
OUT A RAIN/SNOW MIX IN THE SOUTH...THE BEST CHANCE FOR
ACCUMULATING SNOW WILL BE NORTH OF THE MASS PIKE. QPF IS BASED ON
HPC VALUES...SNOW CONVERSION TOOLS BRING 2-4 INCH ACCUMULATIONS TO
AREAS OF NORTHWEST MASS AND SOUTHWEST NEW HAMPSHIRE. WE HAVE
ISSUED A WINTER WEATHER ADVISORY FOR NORTHWEST MASS BASED ON THESE
AMOUNTS AND A 3 INCH ADVISORY THRESHOLD. THE THRESHOLD IS HIGHER
IN SOUTHWEST NH...SO NO ADVISORY FOR THERE.

FARTHER SOUTH...EXPECT RAIN TO TURN TO A MIX OF RAIN AND SNOW. THE
MIX WILL LIMIT ACCUMULATIONS.

TEMPS ARE A BLEND OF MOS.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
FRIDAY...
LOW MOVES EAST OF NEW ENGLAND BY FRIDAY AFTERNOON SHIFTING MUCH OF THE
MOISTURE AND LIFT TO OUR EAST. EXPECT THE BEST SUPPORT FOR PRECIP
TO BE IN THE MORNING WITH DIMINISHING POPS MIDDAY AND AFTERNOON.

TEMPS ARE A BLEND OF MOS.

FRIDAY NIGHT...
HIGH PRESSURE FROM CANADA BUILDS SOUTH OVER NEW ENGLAND AND
BRINGING NORTH WINDS AND A SHOT OF COLDER AIR. 850 MB TEMPS FALL
FROM NEAR 0C AT 12Z FRIDAY TO -10C BY 12Z SATURDAY. THE COLDER
DRIER AIR WILL BRING CLEARING FOR A TIME TO THE REGION. UPPER
LEVEL TROUGH APPROACHES FROM THE WEST LATE IN THE PERIOD ALONG
WITH THE LEFT ENTRANCE REGION OF THE UPPER JET. ALL THIS WILL MEAN
A MIX OF CLOUD COVER DURING THE LATTER PART OF THE NIGHT.

THE COLD AIR AND WILL ALSO GENERATE OCEAN EFFECT OVER
MASSACHUSETTS BAY AND CAPE COD. 850 MB TEMPS WILL BE NEAR -8C
WHILE WATER TEMPS IN THE BAY ARE 8-9C. THIS 16-17C DIFFERENTIAL
AND WINDS OF 10-12 KNOTS WILL SUPPORT THIS FORMATION. THE NORTH
WINDS WILL MOVE THE BANDS OF CLOUDS AND RAIN/SNOW SHOWERS OVER
MUCH OF CAPE COD AND POSSIBLY NANTUCKET. WE MAINTAINED CHANCE POPS
FOR THIS AREA.

TEMPS ARE A BLEND OF MOS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
MAIN POINTS...

* OCEAN EFFECT RAIN/SNOW SHOWERS PSBL SAT
* SERIES OF UPR LVL DISTURBANCES ANTICIPATED FOR SUNDAY WITH CHC POPS
* MONDAY LOOKS TO BE BLUSTERY AS DISTURBANCES MERGE OFFSHORE
* HIGH PRES AND WARMER CONDITIONS RETURN INTO TUESDAY

OVERVIEW AND MODEL PREFERENCES...
12Z GUIDANCE SUITE IN BETTER AGREEMENT THAN THE LAST FEW
DAYS...ALTHOUGH SOME ISSUES WILL STILL NEED TO BE RESOLVED LATE
WEEKEND AND EARLY NEXT WORK WEEK. 1030+ HPA HIGH PRES SETTLES OVER
THE REGION THROUGH MUCH OF THE DAY SUN AS SHORTWAVES PUSH THROUGH
THE FLOW ALOFT. THE BIGGEST DIFFERENCES ARE IN THE SUN NIGHT AND
MON TIMEFRAME AS SRN AND NRN STREAM WAVES LOOK TO PHASE AS THEY
CONVERGE ON NEW ENGLAND. WHILE THERE REMAIN TEMPORAL AND SPATIAL
DIFFERENCES BETWEEN MODELS ON THE RESULTANT DEEP WAVE...SFC
CYCLOGENESIS REMAINS WELL OFFSHORE AND TO THE SE BEFORE PUSHING TO
THE NE. GIVEN THIS...SO ATTM...NOT EXPECTING MUCH IN THE WAY OF
IMPACT FROM THIS FEATURE. WILL LEAN TOWARDS ECMWF SOLN WHICH HAS
SHOWN BETTER RUN TO RUN CONSISTENCY WITH THIS OFFSHORE
CYCLOGENESIS THE LAST COUPLE FEW RUNS. MODELS THEN AGREE THAT
STRONG RIDGING BUILDS OVER THE NE AND WILL DOMINATE THE SENSIBLE
WX THROUGH MUCH OF NEXT WEEK.

DETAILS...

SAT INTO SUN...
STRONG AND COOL HIGH PRES DOMINATES THE NE. COOL NLY FLOW ON THE
BACKSIDE OF EXITING LOW WILL COMBINE WITH SHORTWAVE ENERGY DURING
THE DAY SAT TO INITIATE A NORLUN TROF SOMEWHERE IN THE NH AND SRN
ME REGION. HOWEVER...WITH H92 TEMPS DROPPING TO AROUND -8C AND
WATER TEMPS +8 TO +10C...LVL INSTABILITY WILL INITIATE A FAIR
AMOUNT OF OCEAN EFFECT CLOUDS AND SHOWERS WITHIN THE NLY FLOW.
THIS WILL BE AIDED BY THE EXTRA LIFT PROVIDED BY THE INCOMING
SHORTWAVE. BEST CHANCE FOR THIS WILL BE EXTREME SE MA/CAPE/ISLANDS
AND EXTREME ERN COASTAL MA...SO WILL CONCENTRATE POPS THERE.
DYNAMIC COOLING MAY BE ENOUGH TO GENERATE MOSTLY -SN OVER THESE
REGIONS...BUT MIXING WITH RAIN IS JUST AS LIKELY GIVEN THE WARM
OCEAN TEMPS.

THE HIGH PRES CRESTS THE REGION LATE SAT NIGHT BRINGING OCEAN
EFFECT SHOWERS TO AN END. GIVEN WEAK FLOW AND NEAR SKC CONDITIONS
OVERNIGHT THE COOL AIRMASS WILL YIELD A FAIR AMOUNT OF RAD
COOLING. INTERIOR MINS WILL LIKELY DROP INTO THE TEENS. FOR
SUN...HIGH PRES SHIFTS OFFSHORE WITH INCREASING CLOUDINESS IN
ADVANCE OF A COLD FRONT. EXPECT THAT MUCH OF THE REGION WILL
REMAIN NEAR SEASONABLE AND DRY FOR THE HOLIDAY.

SUN NIGHT THROUGH MON...
NRN AND SRN STREAM SHORTWAVES PHASE IN THE GT LAKES REGION
YIELDING DEEP LONGWAVE TROF AFFECTING MUCH OF THE NE MON NIGHT
INTO THE DAY MON. THE INITIAL SFC REFLECTION OVER SOUTHERN NEW
ENGLAND IS A COLD FRONT EXPECTED TO CROSS THE AREA FROM 06Z TO
12Z. GIVEN THAT THERE IS STILL SOME UNCERTAINTY IN PLACEMENT AND
TIMING OF COASTAL CYCLOGENESIS EARLY MORN MON...THERE MAY BE SOME
PRECIP/WIND IMPACTS ESPECIALLY OVER THE SE PORTIONS OF THE
FA...WILL CONCENTRATE HIGHEST POPS IN THIS AREA. GIVEN THE LOW
WILL STRENGTHEN MOSTLY WELL E OF THE AREA...DO NOT FEEL IMPACTS
WILL BE TOO GREAT ATTM. OTHERWISE...REMNANT RIDGING IN ADVANCE OF
THE WAVE WILL LIKELY KEEP MUCH OF THE INTERIOR DRY DESPITE THE
COLD FROPA...BUT WILL DEPEND ON WHETHER OR NOT SOME OF THE LAKE
EFFECT PRECIP IS ABLE TO AFFECT THE NW IN THE CAA MON. TEMPS
GENERALLY NEAR NORMAL...TO SLIGHTLY ABOVE GIVEN FAIR AMOUNT OF
CLOUD COVER AND SOME WAA IN ADVANCE OF THE COLD FRONT.

TUE INTO THU...
BROAD SCALE RIDGING COMBINES WITH PERSIST BERMUDA HIGH SETUP
THROUGH MUCH OF NEXT WEEK. INVERTED RIDGING FROM THE SW SUGGESTS A
SLIGHTLY WARMER THAN NORMAL AIRMASS...PARTICULARLY FOR LATE DEC.
MODEL SOUNDINGS FAVOR BROAD SUBSIDENCE...KEEPING THE PASSAGE OF A
WEAK COLD FRONT MOSTLY DRY TUE NIGHT. H92 TEMPS REMAIN GENERALLY
ABOVE 0C FOR THE PERIOD...SO TEMPS LIKELY LEAN ABOVE NORMAL,

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
  LOW...LESS THAN 30 PERCENT
  MODERATE...30 PERCENT TO 60 PERCENT
  HIGH...GREATER THAN 60 PERCENT

TONIGHT...
VFR CONTINUES FOR THE NEXT FEW HOURS...WITH MVFR CIGS ARRIVING
JUST BEFORE MIDNIGHT W OF ORH...AFTER MIDNIGHT E. IFR CONDITIONS
POSSIBLE /ESPECIALLY VSBYS/ IN PERIODS OF RA/SN AFTER MIDNIGHT.
BEST CHANCE FOR SN NW OF BAF TO FIT LINE. HIGH CONFIDENCE IN MVFR
CONDITIONS...LOWER CONFIDENCE IN IFR.

FRIDAY...
MVFR CEILINGS AND MIXED MVFR/IFR VSBYS DURING THE
MORNING. WITH THE BEST CHANCE FOR IFR CONDITIONS IN LOW VSBYS WITH
SN OVER NW MA AND SRN NH. MVFR CEILINGS/VFR VSBYS CONTINUE FOR MUCH
OF THE AFTERNOON. NORTHEAST WINDS IN THE MORNING WILL SHIFT TO
NORTH AND NORTHWEST IN THE AFTERNOON. HIGH CONFIDENCE.

FRIDAY NIGHT...
VFR CONDITIONS IN MOST OF SOUTHERN NEW ENGLAND. HIGH CONFIDENCE.
OCEAN EFFECT CLOUDS AND RAIN/SNOW SHOWERS DEVELOPING OVER
MASSACHUSETTS BAY AND MOVING ACROSS CAPE COD AND ISLANDS. OF THE
TAF SITES...HYA WILL BE MOST AT RISK FOR MVFR/IFR CONDITIONS IN
SHOWERS. FMH AND ACK HAVE A LESSER RISK...BUT NOT ZERO.

KBOS TERMINAL...MODERATE TO HIGH CONFIDENCE IN TAF. VFR DETERIORATING
IN ESPECIALLY AFTER MIDNIGHT TO MVFR. IFR CONDITIONS POSSIBLE
ESPECIALLY TOWARD DAYBREAK...BUT CONFIDENCE IS LOWER IN THIS
POSSIBILITY. MOST PRECIP TO REMAIN IN LIQUID FORM...BUT MAY MIX
WITH SNOW TOWARD MORNING. NORTHEAST WINDS OVERNIGHT BECOMING
NORTH ON FRIDAY. HIGHEST CONFIDENCE IN OVERALL TREND...LOWER
CONFIDENCE IS IN TIMING.

SATURDAY THROUGH TUESDAY...

SAT... MODERATE CONFIDENCE VFR/MVFR. N/NELY FLOW WILL USHER THE
DEVELOPMENT OF SHRA/SHSN ACROSS E MA AND LOW CIGS. FEEL BEST CHCS
FOR MVFR /AND PSBL IFR/ IMPACTS WILL BE FOR THE E MA TERMINALS.

SAT NIGHT INTO SUN...MODERATE TO HIGH CONFIDENCE MOSTLY VFR
THROUGH THE PERIOD.

SUN NIGHT INTO MON...MODERATE CONFIDENCE VFR DOMINATES...BUT MAY
BE SOME MVFR ESPECIALLY E MA TERMINALS AS -SHRA/-SHSN DEVELOP
AHEAD OF A COLD FRONT AND LOW PRES OFFSHORE.

TUE...ANY MVFR CONDITIONS RAPIDLY IMPROVE TO VFR.

&&

.MARINE...
TONIGHT...
WINDS HAVE DIMINISHED BELOW SMALL CRAFT LEVELS...BUT SEAS REMAIN
HAZARDOUS ACROSS THE SOUTHERN OUTER WATERS AS WELL AS THE RHODE
ISLAND WATERS. WITH DIMINISHING WIND WE EXPECT THE SEAS WILL
DIMINISH DURING THE NIGHT.

WINDS WILL SHIFT OVERNIGHT...BECOMING NORTHEAST AFTER MIDNIGHT AS
LOW PRESSURE MOVES UP FROM THE SOUTHEAST USA. EXPECT THESE
OVERNIGHT WINDS TO REMAIN BELOW SMALL CRAFT LEVELS.

A SMALL CRAFT ADVISORY CONTINUES FOR THE SOUTHERN WATERS DUE TO
SEAS.

FRIDAY...
COASTAL LOW PRESSURE PASSES NEAR THE 40N/70W BENCHMARK DURING THE
MORNING. NORTHEAST WINDS WILL SHIFT TO NORTH AND NORTHWEST DURING
THE AFTERNOON. WINDS WILL REACH NEAR 25 KNOTS AT TIMES ON THE
SOUTHERN WATERS ESPECIALLY NEAR NANTUCKET. SEAS WILL REMAIN ROUGH
ON THE SOUTHERN AND SOUTHEAST OUTER WATERS THROUGH THE DAY.

FRIDAY NIGHT...
HIGH PRESSURE BUILDS SOUTH FROM CANADA WITH MUCH COLDER AIR. THE
AIR WILL BE COLD ENOUGH TO GENERATE OCEAN EFFECT CLOUDS AND
RAIN/SNOW SHOWERS OVER MASSACHUSETTS AND CAPE COD BAYS. NORTH
WINDS WILL ALSO GENERATE WIND GUSTS TO 25 KNOTS ACROSS THE WATERS.

SATURDAY THROUGH TUESDAY...

SAT INTO SAT NIGHT...
WINDS AND SEAS REMAIN ELEVATED TO SCA LEVELS DURING THE PERIOD.
WINDS SUBSIDE LATE DAY...SEAS SUBSIDE OVERNIGHT.

SUN INTO SUN NIGHT...
WINDS AND SEAS REMAIN BELOW SCA CONDITIONS AS HIGH PRES CRESTS
OVER THE WATERS.

MON AND TUE...
LOW PRES MOVES E OF THE WATERS AS SECOND STRONG HIGH BUILDS OVER
FROM THE W. EXPECT INCREASING SWELL GREATER THAN 5 FT THROUGH THE
PERIOD ESPECIALLY OUTER WATERS. WINDS MAY BRIEFLY REACH GALE FORCE
DURING THE DAYLIGHT HOURS...OTHERWISE GUSTS TO 25 KT POSSIBLE
THROUGH THE PERIOD.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...WINTER WEATHER ADVISORY FROM 1 AM TO 1 PM EST FRIDAY FOR
     MAZ002>004-008.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 2 PM EST FRIDAY FOR ANZ232.
     SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR ANZ235-237.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST SATURDAY FOR ANZ254>256.

&&

$$
SYNOPSIS...WTB/DOODY
NEAR TERM...WTB/DOODY
SHORT TERM...WTB
LONG TERM...DOODY
AVIATION...DOODY
MARINE...WTB/DOODY








AREA FORECAST DISCUSSION...UPDATED

NWS COLUMBIA SC

 500 PM EST WED DEC 21 2011

.SYNOPSIS...

A SLOW MOVING FRONTAL SYSTEM WILL REMAIN NEAR THE FORECAST AREA
THROUGH THE CHRISTMAS WEEKEND. A SERIES OF LOW PRESSURE SYSTEMS WILL
MOVE NORTHEASTWARD ALONG THE FRONT.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...

WARM ADVECTION PATTERN PERSISTS ACROSS THE FORECAST THIS AFTERNOON
WITH ADEQUATE MOISTURE EVIDENT ON THE 21Z RUC ANALYSIS SOUNDING.
PRECIPITABLE WATER VALUES ARE MAXIMIZED ACROSS THE MIDLANDS WITH
VALUES AROUND 1.5 INCHES...HOWEVER THE BEST MOISTURE TRANSPORT IS
SHIFTING NORTHEAST OF THE FORECAST AREA. THIS CAN BE SEEN IN THE
REGIONAL RADAR MOSAIC WHERE A CLUSTER OF RAIN IS LIFTING OUT OF
THE NORTHEASTERN PART OF THE FORECAST AREA WITH MAINLY FEW TO
SCATTERED SHOWERS REMAINING ACROSS THE AREA.

HAVE UPDATED THE POP FORECAST TO MORE ACCURATELY DEPICT THE
CURRENT ACTIVITY AND EXPECT THE COVERAGE SHOULD CONTINUE TO
DIMINISH INTO THE EVENING AND OVERNIGHT HOURS AS THE 850MB JET
SHIFTS EAST AND MOISTURE TRANSPORT CONTINUES TO WANE. EXPECT
TEMPERATURES TO MOVE LITTLE OVER THE NEXT SEVERAL HOURS WITH
OVERCAST SKIES AND LOW DEWPOINT DEPRESSIONS AND A WELL MIXED
BOUNDARY LAYER. LOWS TONIGHT WILL BE QUITE MILD AND COULD POSSIBLE
SET A RECORD WARMEST LOW AT COLUMBIA.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...

CONVERGENCE AND MOISTURE ASSOCIATED WITH THE SLOW MOVING FRONT WILL
SUPPORT A CONTINUED SHOWER CHANCE. THE GREATER CHANCE MAY BE
THURSDAY NIGHT ASSOCIATED WITH STRONGER CONVERGENCE AHEAD OF THE
FRONT. THE NAM AND GFS SHOW SOME DRYING DEVELOPING FRIDAY AS THE
FRONT PUSHES A LITTLE FARTHER SOUTHEASTWARD. THERE HAVE BEEN
INCONSISTENCIES WITH PREVIOUS RUNS WITH THE TIMING OF THE FRONT
AND A SERIES OF MID-LEVEL SHORTWAVE TROUGHS. USED THE GUIDANCE
CONSENSUS FOR THE POP FORECAST.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...

THE GFS SHOWED THE FRONT LINGERING NEAR THE FORECAST AREA THROUGH
CHRISTMAS DAY WITH DRYING MONDAY. THE MODEL SHOWED ANOTHER WAVE
DEVELOPING AND PUSHING HIGHER MOISTURE BACK INTO THE FORECAST AREA
MONDAY NIGHT AND TUESDAY. RIDGING APPEARED TO BECOME DOMINATE
WEDNESDAY. THE GFS AND ECMWF HAVE TRENDED INTO BETTER AGREEMENT WITH
HIGH MOISTURE CHRISTMAS DAY. THE GFS ENSEMBLES CONTINUED TO DISPLAY
HIGH SPREAD ASSOCIATED WITH THE COMPLEX SPLIT FLOW PATTERN.
CONFIDENCE REMAINED LOW WITH THE FORECAST THROUGH THE EXTENDED
PERIOD. LEANED TOWARD THE GFS ENSEMBLE MEAN POPS.

&&

.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...

SCATTERED AREAS OF LIGHT RAIN HAVE DIMINISHED ACROSS THE AREA OVER
THE PAST FEW HOURS. WILL KEEP MENTION OF VCSH IN THE TAFS UNTIL 00Z.
EXPECT MVFR/IFR CONDITIONS TO DEVELOP BY 00Z WITH PATCHY FOG DURING
THE OVERNIGHT HOURS. CONDITIONS WILL SLOWLY IMPROVE AFTER 16Z
THURSDAY WITH IFR CIGS AND MVFR VSBYS.

EXTENDED AVIATION OUTLOOK...PERIODS OF CIG/VSBY RESTRICTIONS
EXPECTED THROUGH SATURDAY AS A SERIES OF WEATHER SYSTEMS CROSS THE
REGION.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$

NEAR TERM...HC
AVIATION...CL





AREA FORECAST DISCUSSION

NWS LINCOLN IL

 900 PM CST THU DEC 22 2011

.DISCUSSION...
ISSUED 900 PM CST THU DEC 22 2011

BAND OF LIGHT SNOW/FLURRIES HAS PUSHED EAST OF THE I-55 CORRIDOR
INTO EAST CENTRAL ILLINOIS...AND WILL PUSH INTO INDIANA WITHIN
THE NEXT FEW HOURS. A CLEARING LINE IS SINKING TOWARD THE AREA
FROM THE UPPER MIDWEST/WESTERN GREAT LAKES...AND THIS CLEARING
SHOULD SPREAD FROM NORTHWEST TO SOUTHEAST OVERNIGHT INTO EARLY
FRIDAY. THIS CLEARING WILL QUICKLY BE FOLLOWED BY A RIDGE OF HIGH
PRESSURE...PROVIDING QUIET WEATHER LOCALLY FOR THE HOLIDAY
WEEKEND.

GOING FORECAST IS IN GOOD SHAPE OVERALL. ONLY PLAN ON FEW MINOR
TWEAKS FOR THE LATEST AND EXPECTED OVERNIGHT TRENDS.

BAK
&&

.AVIATION...
ISSUED 600 PM CST THU DEC 22 2011

A BAND OF LIGHT SNOW WILL QUICKLY MOVE ACROSS THE CENTRAL ILLINOIS
TERMINALS THIS EVENING...PROVIDING AN HOUR OR TWO OF LIGHT SNOW
OR FLURRIES. LITTLE OR NO SNOW ACCUMULATION IS ANTICIPATED. IFR
CONDITIONS WILL PREVAIL UNTIL THE SNOW BAND CLEARS THE AREA...WITH
CONDITIONS TRENDING MVFR IT ITS WAKE. THEN...CLEARING SKIES ARE
EXPECTED OVERNIGHT. ONCE SKIES CLEAR...THEY SHOULD REMAIN MOSTLY
CLEAR THROUGH THE REMAINDER OF THE 00Z TAF PERIOD AS HIGH PRESSURE
BUILDS INTO THE AREA. THIS HIGH PRESSURE WILL HAVE WINDS BECOMING
LIGHT/VARIABLE BY THE DAYTIME HOURS FRIDAY AS IT PUSHES THROUGH.

BAK
&&

.PREV DISCUSSION...
ISSUED 225 PM CST THU DEC 22 2011

19Z SFC MAP INDICATED WEAK FRONT WASHING OUT NEAR I-57 WITH LIGHT
NORTHERLY BEHIND IT. MAIN WEATHER SYSTEM ACROSS THE COUNTRY WAS
LOCATED WELL TO OUR SOUTHEAST...HOWEVER STRATIFORM RAIN SHIELD
REACHED AS FAR NORTH AS THE OHIO VALLEY...AND CLOUDS ASSOCIATED WITH
THIS FEATURE OVERSPREAD THE ENTIRE AREA. BEYOND THIS EVENING...LITTLE IN
THE WAY OF FORECAST CONCERNS WITH A DRY AND MILD PATTERN PERSISTING
THROUGH MUCH OF NEXT WEEK.

SHORT TERM...TONIGHT AND FRIDAY
A COUPLE ITEMS OF INTEREST THIS EVENING. FIRST...NORTHERN FRINGE OF
OH VALLEY RAINS LOOK TO STAY JUST SOUTHEAST OF THE LAWRENCEVILLE
AREA IN REGION OF BETTER LIFT AND MOISTURE...BUT MAY INSERT LOW CHC POPS
IN THE FAR SE BASED ON LATEST RADAR TRENDS. OTHER ITEM IS RIBBON
OF 850-700 MB FRONTOGENESIS SLIDING SE INTO NRN MO/SE IA
CURRENTLY. RADAR MOSAIC INDICATES LIGHT SNOW BAND DEVELOPING FROM
KMCI TO NEAR KIRK IN MO. LATEST RUN OF HRRR AND 12KM NAM STREAK
THIS BAND TO THE EAST...ACROSS PARTS OF CENTRAL ILLINOIS THIS
EVENING. AIRMASS IS FAIRLY DRY...SO BELIEVE MOST PRECIP GENERATION
WILL BE EATEN BY SATURATION PROCESSES. HOWEVER SOME SCATTERED
FLURRIES OR BRIEF PERIODS OF LIGHT SNOW LOOK POSSIBLE FOR ROUGHLY
THE NW HALF BEFORE FRONTOGENESIS WANES AFTER MIDNIGHT. AS THE MAIN
SYNOPTIC WEATHER FEATURES SHIFT FARTHER EAST TOMORROW...HIGH
PRESSURE WILL BEGIN TO NOSE EAST FROM THE CENTRAL PLAINS. THIS
WILL ALLOW SKIES TO CLEAR FROM WEST TO EAST FOR A WELCOME RETURN
TO SUNSHINE.

LONG TERM...SATURDAY THROUGH THURSDAY
AS HAS BEEN THE CASE MUCH OF THIS EARLY WINTER...SPLIT FLOW JET
STREAM PATTERN WILL DOMINATE THE EXTENDED PORTION OF THE FORECAST.
THIS WILL KEEP ANY ARCTIC AIR BOTTLED UP IN CANADA...AND ANY
MOISTURE-RICH SHORTWAVES WELL TO OUR SOUTH. THIS PATTERN IS
CONSISTENT WITH POSITIVE PHASES OF THE AO AND NAO...AND THESE ARE
FORECAST TO STAY POSITIVE FOR THE NEXT COUPLE WEEKS.

THE HOLIDAY WEEKEND WILL FEATURE EXCELLENT TRAVEL
CONDITIONS...WITH THE CLOSEST PRECIPITATION BEING LAKE EFFECT AND
CLIPPER SNOW FOR THE GREAT LAKES...AND RAIN FROM THE LOWER
MISSISSIPPI VALLEY INTO THE DEEP SOUTH. FOR THE LOCAL
AREA...MOSTLY CLEAR SKIES AND TEMPERATURES RUNNING 5-10 DEGREES
ABOVE NORMAL WILL DOMINATE...WITH ANY CLIPPERS STAYING WELL TO OUR
NORTHEAST. THERE IS SOME MODEL DISAGREEMENT MONDAY NIGHT...WHEN A
SOUTHERN STREAM SHORTWAVE LIFTS INTO THE MS VALLEY. PREVIOUS
GUIDANCE AND THE CURRENT GFS KEEP ANY RAIN WITH THIS FEATURE WELL
SOUTH OF THE AREA...WHILE THE LATEST ECMWF AND GEM BRING RAIN OR A
RAIN/SNOW MIX UP TO THE LOWER GREAT LAKES BY TUESDAY MORNING. FOR
NOW WILL BASE THE FORECAST ON THE MORE CONSISTENT/DRY SOLUTION BUT
KEEP AN EYE ON THIS PERIOD FOR POP ADJUSTMENT. BEYOND THIS
POTENTIAL SYSTEM...ZONAL UPPER LEVEL FLOW WILL PRODUCE DRY AND
SEASONABLY WARM WEATHER THROUGH MID-WEEK.

25

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS LINCOLN IL

 600 PM CST THU DEC 22 2011

.DISCUSSION...
ISSUED 225 PM CST THU DEC 22 2011

19Z SFC MAP INDICATED WEAK FRONT WASHING OUT NEAR I-57 WITH LIGHT
NORTHERLY BEHIND IT. MAIN WEATHER SYSTEM ACROSS THE COUNTRY WAS
LOCATED WELL TO OUR SOUTHEAST...HOWEVER STRATIFORM RAIN SHIELD
REACHED AS FAR NORTH AS THE OHIO VALLEY...AND CLOUDS ASSOCIATED WITH
THIS FEATURE OVERSPREAD THE ENTIRE AREA. BEYOND THIS EVENING...LITTLE IN
THE WAY OF FORECAST CONCERNS WITH A DRY AND MILD PATTERN PERSISTING
THROUGH MUCH OF NEXT WEEK.

SHORT TERM...TONIGHT AND FRIDAY
A COUPLE ITEMS OF INTEREST THIS EVENING. FIRST...NORTHERN FRINGE OF
OH VALLEY RAINS LOOK TO STAY JUST SOUTHEAST OF THE LAWRENCEVILLE
AREA IN REGION OF BETTER LIFT AND MOISTURE...BUT MAY INSERT LOW CHC POPS
IN THE FAR SE BASED ON LATEST RADAR TRENDS. OTHER ITEM IS RIBBON
OF 850-700 MB FRONTOGENESIS SLIDING SE INTO NRN MO/SE IA
CURRENTLY. RADAR MOSAIC INDICATES LIGHT SNOW BAND DEVELOPING FROM
KMCI TO NEAR KIRK IN MO. LATEST RUN OF HRRR AND 12KM NAM STREAK
THIS BAND TO THE EAST...ACROSS PARTS OF CENTRAL ILLINOIS THIS
EVENING. AIRMASS IS FAIRLY DRY...SO BELIEVE MOST PRECIP GENERATION
WILL BE EATEN BY SATURATION PROCESSES. HOWEVER SOME SCATTERED
FLURRIES OR BRIEF PERIODS OF LIGHT SNOW LOOK POSSIBLE FOR ROUGHLY
THE NW HALF BEFORE FRONTOGENESIS WANES AFTER MIDNIGHT. AS THE MAIN
SYNOPTIC WEATHER FEATURES SHIFT FARTHER EAST TOMORROW...HIGH
PRESSURE WILL BEGIN TO NOSE EAST FROM THE CENTRAL PLAINS. THIS
WILL ALLOW SKIES TO CLEAR FROM WEST TO EAST FOR A WELCOME RETURN
TO SUNSHINE.

LONG TERM...SATURDAY THROUGH THURSDAY
AS HAS BEEN THE CASE MUCH OF THIS EARLY WINTER...SPLIT FLOW JET
STREAM PATTERN WILL DOMINATE THE EXTENDED PORTION OF THE FORECAST.
THIS WILL KEEP ANY ARCTIC AIR BOTTLED UP IN CANADA...AND ANY
MOISTURE-RICH SHORTWAVES WELL TO OUR SOUTH. THIS PATTERN IS
CONSISTENT WITH POSITIVE PHASES OF THE AO AND NAO...AND THESE ARE
FORECAST TO STAY POSITIVE FOR THE NEXT COUPLE WEEKS.

THE HOLIDAY WEEKEND WILL FEATURE EXCELLENT TRAVEL
CONDITIONS...WITH THE CLOSEST PRECIPITATION BEING LAKE EFFECT AND
CLIPPER SNOW FOR THE GREAT LAKES...AND RAIN FROM THE LOWER
MISSISSIPPI VALLEY INTO THE DEEP SOUTH. FOR THE LOCAL
AREA...MOSTLY CLEAR SKIES AND TEMPERATURES RUNNING 5-10 DEGREES
ABOVE NORMAL WILL DOMINATE...WITH ANY CLIPPERS STAYING WELL TO OUR
NORTHEAST. THERE IS SOME MODEL DISAGREEMENT MONDAY NIGHT...WHEN A
SOUTHERN STREAM SHORTWAVE LIFTS INTO THE MS VALLEY. PREVIOUS
GUIDANCE AND THE CURRENT GFS KEEP ANY RAIN WITH THIS FEATURE WELL
SOUTH OF THE AREA...WHILE THE LATEST ECMWF AND GEM BRING RAIN OR A
RAIN/SNOW MIX UP TO THE LOWER GREAT LAKES BY TUESDAY MORNING. FOR
NOW WILL BASE THE FORECAST ON THE MORE CONSISTENT/DRY SOLUTION BUT
KEEP AN EYE ON THIS PERIOD FOR POP ADJUSTMENT. BEYOND THIS
POTENTIAL SYSTEM...ZONAL UPPER LEVEL FLOW WILL PRODUCE DRY AND
SEASONABLY WARM WEATHER THROUGH MID-WEEK.

25
&&

.AVIATION...
ISSUED 600 PM CST THU DEC 22 2011

A BAND OF LIGHT SNOW WILL QUICKLY MOVE ACROSS THE CENTRAL ILLINOIS
TERMINALS THIS EVENING...PROVIDING AN HOUR OR TWO OF LIGHT SNOW
OR FLURRIES. LITTLE OR NO SNOW ACCUMULATION IS ANTICIPATED. IFR
CONDITIONS WILL PREVAIL UNTIL THE SNOW BAND CLEARS THE AREA...WITH
CONDITIONS TRENDING MVFR IT ITS WAKE. THEN...CLEARING SKIES ARE
EXPECTED OVERNIGHT. ONCE SKIES CLEAR...THEY SHOULD REMAIN MOSTLY
CLEAR THROUGH THE REMAINDER OF THE 00Z TAF PERIOD AS HIGH PRESSURE
BUILDS INTO THE AREA. THIS HIGH PRESSURE WILL HAVE WINDS BECOMING
LIGHT/VARIABLE BY THE DAYTIME HOURS FRIDAY AS IT PUSHES THROUGH.

BAK
&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$










AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

 527 PM CST THU DEC 22 2011


.AVIATION...
HIGH PRESSURE BUILDING INTO THE PLAINS IS BRINGING COLDER...DRIER
AIR INTO THE LOCAL AREA THIS EVENING. PUSHING THE LOW CLOUDS
SOUTHEASTWARD. PATCHY PERIODS OF MVFR CONDITIONS DUE TO CLOUD
BASES OF 2-3K AGL WILL END AT ALL TERMINALS BY 03Z WITH FAIR SKIES
AFTERWORD. VISIBILITIES WILL STAY AOA 7 MILES WITH NW TO NORTH
WINDS OF 5 TO 10 MPH BECOMING SOUTHWEST BY LATE MORNING FRIDAY.
..NICHOLS..

&&

.PREV DISCUSSION... /ISSUED 321 PM CST THU DEC 22 2011/

SYNOPSIS...
SURFACE ANALYSIS AT 18Z SHOWED THE COLD FRONT THAT MOVED THROUGH
OVERNIGHT STRETCHED FROM NE TX ACROSS FAR SOUTHERN IL TO LOWER MI. A
1032 HIGH WAS BUILDING INTO SD AND NE WITH A RESULTING TIGHT
PRESSURE GRADIENT ACROSS IA PRODUCING 15 TO 20 KT NORTHERLY WINDS
OVER MUCH OF THE FORECAST AREA. SATELLITE IMAGES INDICATED THE BACK
EDGE OF THE SOUTHWARD RETREATING STRATUS DECK REACHING FROM KOTM TO
NEAR GALENA. A NARROWER...MORE CONVECTIVE LOOKING CLOUD DECK WITH
MVFR BASES WAS FURTHER NORTH ACROSS NE IA INTO WI...SHOWING SINGS OF
SHRINKING AS IT WAS ADVANCING SLOWLY SOUTHWARD. FURTHER SOUTH...AREA
RADARS SHOWED AN EXPANDING BAND OF REFLECTIVITY FROM KIRKSVILLE TO
THE QUAD CITIES...LIKELY ASSOCIATED WITH A WEAK MID LEVEL VORT
MOVING THROUGH THE AREA AND THE DEPARTING 300 MB JET CORE. 12Z
ANALYSIS REVEALED THIS JET MAX EMBEDDED IN THE UPPER LEVEL SW FLOW
AHEAD OF A NORTHERN STREAM TROUGH FROM HUDSON BAY SE INTO NEB AND A
SEPARATE...MORE CUTOFF...MID AND UPPER LEVEL CIRCULATION OVER
SOUTHERN UT.

SHORT TERM...TONIGHT AND FRIDAY...
INITIAL CONCERN IS THE POTENTIAL FOR VERY LIGHT SNOW OR FLURRIES
OVER THE NEXT SEVERAL HOURS...THEN FOCUS TURNS TO OVERNIGHT LOW
TEMPERATURES. THE EXPANDING AND INCREASING BAND OF LIGHT SNOW
MENTIONED IN THE SYNOPSIS OVER THE SOUTH HAS RECENTLY BEGUN SHOWING
UP WITH GENERALLY 1 TO 4SM -SN ALONG THE MS RIVER SOUTH OF
MUSCATINE. BASED ON VSBYS AND RADAR TRENDS...COULD SEE A QUICK
DUSTING TO POSSIBLE 1/2 INCH BEFORE THE MID LEVEL FORCING...WHICH
THE LATEST RUC AND NAM12 HAVE A ROUGH HANDLE ON...QUICKLY PUSHES
EAST BEFORE 00Z. HAVE THUS INCREASED A SMALL AREA TO LIKELY POPS FOR
LATE AFTERNOON FOR ALONG AND EAST OF THE MS RIVER SOUTH OF THE QUAD CITIES
INTO IL.

OVERNIGHT...HIGH PRESSURE RIDGE EXTENDING W-NW FROM THE HIGH PLAINS
HIGH...ALONG WITH MID LEVEL SUBSIDENCE BEHIND THE SHORTWAVE PASSING
TO THE NORTH SHOULD PUSH THE LOW CLOUDS SOUTH OF THE AREA BY
MIDNIGHT. CLEARING SKIES AND LIGHT WINDS SHOULD RESULT IN THE
COLDEST NIGHT IN SEVERAL DAYS...AND BASED ON TRAJECTORIES...LOWS
CLOSE TO GUIDANCE BLEND FROM AROUND 15 NORTH TO LOWER 20S SOUTH LOOK
REASONABLE. FRIDAY...SUNSHINE...LACK OF SNOW COVER...AND RETURN FLOW
SOUTHWEST WINDS WILL ALLOW TEMPERATURES TO RECOVER WELL INTO THE
30S. ..SHEETS..

LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY...
THE EXTENDED FORECAST REMAINS DOMINATED BY MOSTLY BENIGN NORTHWEST
FLOW FRONTAL PASSAGES. THIS NORMALLY REPRESENTS A BELOW NORMAL
FORECAST FOR TEMPERATURES...BUT WITH SPLIT FLOW...THIS SHOULD KEEP
TEMPERATURES GENERALLY ABOVE NORMAL...AND ALSO WILL KEEP POPS VERY
LOW. THERE REMAINS TWO POTENTIAL POP CHANCES IN THE EXTENDED...BUT
BOTH ARE POORLY SHOWN WITH RESPECT TO CONSISTENCY IN ANY ONE MODEL
RUN.  THE FIRST...MONDAY AND MONDAY NIGHT... THE MODEL BLEND KEEPS
THE FORECAST DRY AS THE GFS CONTINUES TO SHOW A CLIPPER PASSING WELL
NORTH OF THE CWA....RESULTING IN DRY WAA DAY. HOWEVER...THE ECMWF
AND CANADIAN BOTH BRING THE CUT OFF LOW FROM THE SOUTHWEST UP OVER
THE CWA MONDAY AND MONDAY NIGHT...RESULTING IN POTENTIAL RAIN OR
SNOW. FOR NOW...HAVE BUMPED UP POPS TO 10 TO 14 PERCENT AND SKY
COVER AS WELL...BUT LEFT DRY.

AFTER SEVERAL MORE DAYS OF BENIGN NORTHWEST FLOW...MODELS SHOW
ANOTHER BROAD TROF MOVING PAST THE REGION AROUND FRIDAY. THIS WAVE
INITIALIZED WITH SLIGHT TO LOW CHANCE POPS FOR SNOW.

TEMPERATURES THROUGHOUT THE FORECAST ARE GENERALLY FROM THE MID 30S
TO MID 40S...WITH LOWS IN THE MID 20S TO LOWER 30S. SUCH
TEMPERATURES ARE VERY MILD FOR THE SHORTEST DAYS OF THE YEAR.
.ERVIN..

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

NICHOLS
















AREA FORECAST DISCUSSION...UPDATED

NWS TOPEKA KS

 1123 PM CST TUE DEC 20 2011

...UPDATE TO AVIATION...

.DISCUSSION...

SHORT RANGE (TONIGHT AND WEDNESDAY)...

20Z WATER VAPOR IMAGERY AND ASSOCIATED RUC ANALYSIS CONTINUES TO
SHOW THE 500 MB TROUGH MOVING SLOWLY TO THE NORTHEAST ACROSS EASTERN
KANSAS. CURRENTLY IT IS SITTING OVER SOUTH CENTRAL KANSAS AND SHOULD
PUSH THROUGH THE AREA BY TONIGHT. RADAR TRENDS SHOW PRECIPITATION
ENDING ACROSS CENTRAL KANSAS...AND THIS TREND SHOULD CONTINUE
THROUGH THE REST OF THE EVENING AS THE BETTER LIFT ASSOCIATED WITH
THIS SYSTEM PUSHES EAST. ANOTHER SHIELD OF LIGHT PRECIPITATION IS
MOVING NORTHEASTWARD ALONG THE KANSAS TURNPIKE AND WILL LIKELY BRING
ANOTHER ROUND OF MIXED PRECIPITATION TO AREAS EAST OF THE TURNPIKE.
CURRENTLY KUKL INDICATES 36 DEGREES AS DOES KOJC...SO EXPECT THE
BULK OF THE REMAINING PRECIP TO FALL IN THE FORM OF A RAIN/SNOW MIX
FOR THE REMAINDER OF THE EVENING ALONG THE NEWLY FORMED DEFORMATION
BAND. EXPECT THE BEST LIFT WITH THIS ROUND OF SHOWERS TO MOVE OFF TO
THE EAST BY LATE THIS EVENING THUS ENDING ALL PRECIP FOR OUR
FORECAST AREA. SHOULD THERE BE ANY SNOW ASSOCIATED WITH THIS
EVENINGS PRECIP DON`T EXPECT MUCH MORE THAN A DUSTING OF SNOW ON
GRASSY SURFACES. SINCE ROADWAYS ARE WET FROM THE ONGOING PRECIP AND
OVERNIGHT LOWS WILL DROP INTO THE TEENS TO TWENTIES THERE IS A
POTENTIAL FOR SLICK SPOTS ON ROADWAYS...ESPECIALLY ONCE TEMPS DIP
BELOW 32 DEGREES. SKIES WILL GRADUALLY CLEAR BEHIND THE DEPARTING
SYSTEM...FIRST ACROSS CENTRAL AND NORTH CENTRAL KANSAS...THEN BY 12Z
ACROSS FAR EASTERN KANSAS. AS A RESULT OF THE NEWLY FALLEN SNOW
ACROSS C/NC KANSAS AND THE CLEARING SKIES EXPECT LOW TEMPS TO REACH
INTO THE MID TEENS TONIGHT...AND INTO THE LOWER TO MID 20S FURTHER
EAST WHERE NO SNOW FELL AND SKIES WILL BE SLOWER TO CLEAR. WEDNESDAY
WILL BRING A MILD DAY ACROSS NORTHEAST KANSAS AS TEMPS WILL REACH
INTO THE LOWER TO MID 40S WHERE NO NEW SNOW FELL...BUT WILL ONLY
REACH THE MID 30S OVER THE SNOW PACK IN C/NC KANSAS. JL

THURS-TUES...AFTER A BREAK FROM THE CLOUDS AND
PRECIPITATION...THE NEXT UPPER TROF APPROACHES THE STATE FROM THE
NORTH AND NORTHWEST THURSDAY AND THROUGH FRIDAY. AT THIS TIME MAIN
PIECE OF ENERGY AND DYNAMICS STAYS TO THE WEST...LEAVING THE LEAD
SHEAR VORTICITY AHEAD OF THE NORTHERN WAVE TO SLIDE ACROSS KANSAS.
ENOUGH LIFT WITH THIS AND COUPLED WITH SOME FRONTOGENETIC FORCING
TO BRING A CHANCE OF SNOW THROUGH FRIDAY. NOT MUCH MOISTURE TO
WORK WITH SO DONT EXPECT MUCH FOR ACCUMULATIONS DESPITE HIGHER
SNOW TO LIQUID RATIOS THAN THE PREVIOUS STORM. STILL VARIATIONS IN
THE GUIDANCE AS TO HOW TO HANDLE THE WESTERN PORTION OF THIS
SYSTEM WITH EC/NAM TRENDING A SOUTHWARD SLOWER TRACK AND GFS MORE
PROGRESSIVE ACROSS AND OUT OF OUR AREA. EC IS THEREFORE COOLER IN
THE EXTENDED WHILE GFS IS WARMER IN MORE WESTERLY FLOW. HAVE DRY
CONDITIONS BEYOND FRIDAY WITH A SLOW WARMING TREND...AND WILL HAVE
TO WATCH EVOLUTION OF THAT UPPER PATTERN FOR CHANGES. 67


&&

.AVIATION...

LAST ROUND OF SNOW EXITING THE TERMINALS...SO EXPECT REMAINDER OF
THE FCST TO BE DRY...ALTHOUGH WILL STILL TAKE A FEW HOURS
FOR MVFR CIGS TO CLEAR OUT. BEYOND THE ONSET OF CLEARING...POTENTIAL
FOR GROUND FOG THROUGH SUNRISE WITH THE WET/SNOWCOVERED GROUND WILL
BE THE FOCUS OF CONCERN IN THE TERMINALS UNTIL AROUND 14Z...OTHERWISE
SKC WITH SOUTHWEST WINDS GENERALLY UNDER 10KTS REMAINDER OF THE FCST.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS GRAY ME

 953 PM EST THU DEC 22 2011

.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTHEAST FROM THE MID ATLANTIC STATES
TONIGHT THEN CONTINUE TO MOVE TO THE NORTHEAST JUST BEYOND THE
GULF OF MAINE ON FRIDAY. HIGH PRESSURE AND DRY AIR FOLLOWS FOR
LATER SATURDAY INTO CHRISTMAS DAY. A WEAK WARM FRONT COULD PRODUCE
A FEW SNOW SHOWERS ACROSS NORTHERN SECTIONS OF THE AREA LATE
CHRISTMAS DAY. A COLD FRONT WILL CROSS THE AREA EARLY MONDAY,
WHILE AN OCEAN LOW PASSES WELL SOUTH AND EAST OF THE AREA. HIGH
PRESSURE WILL BUILD BY TO OUR SOUTH LATE MONDAY INTO TUESDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
UPDATE...

***HAVE ISSUED WINTER WEATHER ADVISORIES FOR MUCH OF SOUTHERN NH
 (EXCEPT ROCKINGHAM COUNTY) AS WELL AS INTERIOR YORK COUNTY MAINE***

LOW LEVEL TEMPERATURES: FOR A COUPLE HOURS THIS
EVENING...TEMPERATURES TOOK A NOSEDIVE NORTH OF A LINE FROM ABOUT
LACONIA NH...EASTWARD TO SANFORD MAINE. JUST AFTER SUNSET...AN
AREA OF LOW CLOUDS DEVELOPED SOUTH OF THIS LINE...INHIBITING
FALLING TEMPERATURES WHILE CLEAR SKIES REMAINED TO THE NORTH.
SINCE THEN...THE LOW CLOUDS HAVE DISSIPATED...WITH JUST HIGH
CLOUDS STREAMING ACROSS CENTRAL AND NORTHERN AREAS. AT THIS
TIME...HAVE ADJUSTED TEMPERATURES DOWNWARDS BASED ON THE
DIFFERENCES LAST HOUR BETWEEN THE FORECAST DATABASE AND
OBSERVATIONS AS OF 01Z. DESPITE REMAINING IN THE UPPER 30S HERE AT
GYX (2M TEMPERATURE)...THE SIDEWALKS AND GRASSY SURFACES IN THE
AREA ARE BEGINNING TO FREEZE UP ALREADY.

00Z SOUNDING: EVENING SOUNDING AT GYX CONTINUES TO CONTAIN PLENTY
OF DRY AIR AVAILABLE FOR EVAPORTIONAL COOLING. LOW LEVEL
TEMPERATURES WERE VERY CLOSE TO PROGS...PERHAPS EVER SO SLIGHTLY COOLER.

QPF: IN ADDITION TO THE COOL BIAS OVERNIGHT OVER THE NORTHERN 2/3
OF THE FORECAST AREA...SHORT TERM MODELS ARE STEADILY COMING IN
WITH SLIGHTLY MORE QPF FROM RUN TO RUN. THE HRRR MODEL NOW SHOWS
STORM TOTAL QPF OVER .50 INCHES OVER ALL OF SOUTHERN NH AND IN
YORK COUNTY ME...WITH THE NEXT CLOSEST MODEL IN TERMS OF QPF BEING
THE WETTER EURO. 18Z GFS AND NAM HAVE NUDGED UPWARDS AS WELL...AND
WE ARE AWAITING THE NAM. 21Z SREF NOW SHOWS UP TO 70% LIKELIHOOD
OF 4"OR MORE OVER ALL OF SRN NH...EXTENDING INTO FAR WESTERN
MAINE.

SNOWFALL: BASED ON MUCH OF THE INFORMATION DISCUSSED ABOVE...WILL
BE ADJUSTING SNOWFALL ACCUMULATIONS SLIGHTLY UPWARDS FOR SOUTHERN
AND CENTRAL AREAS DURING THE NEXT HOUR - INTO THE 3 TO 6 INCH
RANGE. THE HIGHER TOTALS WILL BE IN THE HILLTOWNS. ALONG THE COAST...FROM
COASTAL YORK COUNTY AND PORTIONS SOUTH...THERE WILL STILL BE
BOUNDARY LAYER PROBLEMS WITH RAIN MIXING IN WITH TIMES. THIS WILL
KEEP ACCUMULATIONS DOWN...ESPECIALLY ALONG COASTAL ROCKINGHAM
COUNTY WHERE LITTLE SNOWFALL WILL OCCUR.

MINOR ADJUSTMENT MADE TO OTHER PRODUCTS INCLUDING SLOWING THE
TIMING OF THE HIGH POPS...BUT ALL IN ALL...GRIDS APPEAR TO BE IN
GOOD SHAPE. WILL LIKELY BE ISSUING A STATEMENT LATER THIS EVENING
TO ACCOUNT FOR THE TIMING AND PTYPE TRENDS...SINCE MUCH OF THIS
WILL AFFECT THE MORNING RUSH HOUR.

TIMING OF STEADY PCPN: LATEST HRRR RUN BRINGS THE INITIAL
PRECIPITATION INTO SOUTHERN NEW HAMPSHIRE AROUND 05Z OR 06Z WITH
THE HEAVIEST/STEADIEST PRECIPITATION ENTERING SOUTHERN NEW
HAMPSHIRE AROUND 09Z WHICH SEAMS REASONABLE AT THIS TIME.

PREV DISC...
A WEAK AND FAST MOVING SFC LOW MOVES NE FROM THE MID ATLANTIC
STATES TNGT THEN TRACKS TO THE NE JUST BEYOND THE GULF OF MAINE
FRIDAY...REACHING E OF THE HAGUE LINE LATE IN THE DAY. THE TRACK
IS ABOUT OVER THE BENCHMARK OF 40N 70W BUT DUE TO ITS RAPID
MOVEMENT AMOUNTS SHOULD REMAIN LIGHT. ALSO THE UPR LVL SUPPORT IS
LIMITED WITH A POSITIVE TILTED TROF AND A WEAK SFC LOW AS A
RESULT. STILL...THE MODELS FCST GENERALLY 2-4 INCHES OF SNOW WITH
THE HIGHEST AMOUNTS OVER SOUTHERN AREAS OF INTERIOR MAINE AND NH.
A FEW HIGHER AMOUNTS OF AROUND 5 INCHES CAN`T BE RULED OUT OVER
SOME AREAS OF HIGHER TERRAIN OVER SOUTHERN INTERIOR PORTIONS. THE
MOUNTAINS WILL SEE THE LEAST AMOUNT OF SNOWFALL WITH THIS SYSTEM
WITH ONLY AN INCH OR TWO EXPECTED.

THE TIMING OF THE PCPN IS FOR IT TO BEGIN OVER SOUTHWEST AREAS
AROUND OR SHORTLY AFTER MIDNIGHT BUT THEN RAPIDLY DEVELOP AND
OVERSPREAD THE REST OF THE REGION BY 10Z.

THE PRCP COULD START AS -RA OR MIXED -RASN OVER MORE SERN AND
COASTAL AREAS TNGT AS BOUNDARY LAYER UP TO 925 MB WILL HAVE TEMPS
AROUND OR JUST ABOVE FREEZING. EVENTUALLY PRCP CHANGES TO SN AS
TEMPS COOL DOWN. ON FRIDAY THE SN MAY MIX BACK TO RA IN THE MRNG OVER
THESE AREAS AS SFC AND BOUNDARY LAYER TEMPS AGAIN BEGIN TO CLIMB
INTO THE MID 30S.

&&

.SHORT TERM /FRIDAY NIGHT/...
CANADIAN HIGH PRES BUILDS SLOWLY SOUTH SO SOME CLEARING AND DRY CONDITIONS
EXPECTED WITH A RETURN TO MUCH COLDER TEMPS. USED A 50/50 BLEND
OF THE MAV/MET TEMPS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
QUIET WEATHER FOR THE MOST THROUGH THE PERIOD. PERHAPS A FEW SNOW
SHOWERS XMAS AFTERNOON AND EVENING WITH SHORT WAVE TROUGH. THIS
MAY START AS SOME LIGHT OCEAN ENHANCED SNOW ON THE MID COAST
DURING THE AFTERNOON ON XMAS. OTHERWISE...WE/LL HAVE TO WAIT UNTIL
THE 28TH OR SO FOR THE POSSIBILITY OF ANYTHING DECENT IN THE
PRECIPITATION DEPT...AND EVEN THEN THE MODELS HAVE BEEN
INCONSISTENT.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...VFR CONDS THIS EVENING WILL BECOME MVFR TO IFR AFTER
MIDNIGHT FROM SOUTH TO NORTH AS SNOW DEVELOPS AND SPREADS NORTH.
OVER SOUTHEAST NEW HAMPSHIRE THE PCPN MAY FALL AS A MIX AT TIMES.
CONDITIONS WILL GRADUALLY IMPROVE TO VFR FRIDAY AFTERNOON ALTHOUGH
SOME SCATTERED SNOW SHOWERS MAY BRIEFLY REDUCE CIGS/VSBYS TO MVFR.
VFR CONDS ACROSS ALL AREAS FRIDAY NIGHT.

LONG TERM...MAINLY VFR THROUGH TUESDAY. A PERIOD OF MVFR POSSIBLE
XMAS DAY AND NIGHT IN SNOW SHOWERS.

&&

.MARINE...
SHORT TERM...WINDS AND SEAS WILL REMAIN BELOW SCA LEVELS
TNGT AND FRIDAY AS A WEAK AND FAST MOVING COASTAL LOW PASSES SOUTH
OF NEW ENGLAND. CANADIAN HIGH PRESSURE TO OUR NORTH SLOWLY BUILDS
SOUTH ACROSS THE WATERS FRIDAY NIGHT.

LONG TERM...SCA CONDS POSSIBLE OVER THE WEEKEND.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY FROM 1 AM TO 1 PM EST FRIDAY FOR
     MEZ018.
NH...WINTER WEATHER ADVISORY FROM 1 AM TO 1 PM EST FRIDAY FOR
     NHZ005>010.
MARINE...NONE.

&&

$$
JC





AREA FORECAST DISCUSSION

NWS GRAY ME

 853 PM EST THU DEC 22 2011

.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTHEAST FROM THE MID ATLANTIC STATES
TONIGHT THEN CONTINUE TO MOVE TO THE NORTHEAST JUST BEYOND THE
GULF OF MAINE ON FRIDAY. HIGH PRESSURE AND DRY AIR FOLLOWS FOR
LATER SATURDAY INTO CHRISTMAS DAY. A WEAK WARM FRONT COULD PRODUCE
A FEW SNOW SHOWERS ACROSS NORTHERN SECTIONS OF THE AREA LATE
CHRISTMAS DAY. A COLD FRONT WILL CROSS THE AREA EARLY MONDAY,
WHILE AN OCEAN LOW PASSES WELL SOUTH AND EAST OF THE AREA. HIGH
PRESSURE WILL BUILD BY TO OUR SOUTH LATE MONDAY INTO TUESDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
UPDATE...

LOW LEVEL TEMPERATURES: FOR A COUPLE HOURS THIS
EVENING...TEMPERATURES TOOK A NOSEDIVE NORTH OF A LINE FROM ABOUT
LACONIA NH...EASTWARD TO SANFORD MAINE. JUST AFTER SUNSET...AN
AREA OF LOW CLOUDS DEVELOPED SOUTH OF THIS LINE...INHIBITING
FALLING TEMPERATURES WHILE CLEAR SKIES REMAINED TO THE NORTH.
SINCE THEN...THE LOW CLOUDS HAVE DISSIPATED...WITH JUST HIGH
CLOUDS STREAMING ACROSS CENTRAL AND NORTHERN AREAS. AT THIS
TIME...HAVE ADJUSTED TEMPERATURES DOWNWARDS BASED ON THE
DIFFERENCES LAST HOUR BETWEEN THE FORECAST DATABASE AND
OBSERVATIONS AS OF 01Z. DESPITE REMAINING IN THE UPPER 30S HERE AT
GYX (2M TEMPERATURE)...THE SIDEWALKS AND GRASSY SURFACES IN THE
AREA ARE BEGINNING TO FREEZE UP ALREADY.

00Z SOUNDING: EVENING SOUNDING AT GYX CONTINUES TO CONTAIN PLENTY
OF DRY AIR AVAILABLE FOR EVAPORTIONAL COOLING. LOW LEVEL
TEMPERATURES WERE VERY CLOSE TO PROGS...PERHAPS EVER SO SLIGHTLY COOLER.

QPF: IN ADDITION TO THE COOL BIAS OVERNIGHT OVER THE NORTHERN 2/3
OF THE FORECAST AREA...SHORT TERM MODELS ARE STEADILY COMING IN
WITH SLIGHTLY MORE QPF FROM RUN TO RUN. THE HRRR MODEL NOW SHOWS
STORM TOTAL QPF OVER .50 INCHES OVER ALL OF SOUTHERN NH AND IN
YORK COUNTY ME...WITH THE NEXT CLOSEST MODEL IN TERMS OF QPF BEING
THE WETTER EURO. 18Z GFS AND NAM HAVE NUDGED UPWARDS AS WELL...AND
WE ARE AWAITING THE NAM. 21Z SREF NOW SHOWS UP TO 70% LIKELIHOOD
OF 4"OR MORE OVER ALL OF SRN NH...EXTENDING INTO FAR WESTERN
MAINE.

SNOWFALL: BASED ON MUCH OF THE INFORMATION DISCUSSED ABOVE...WILL
BE ADJUSTING SNOWFALL ACCUMULATIONS SLIGHTLY UPWARDS FOR SOUTHERN
AND CENTRAL AREAS DURING THE NEXT HOUR. ALONG THE COAST...FROM
COASTAL YORK COUNTY AND PORTIONS SOUTH...THERE WILL STILL BE
BOUNDARY LAYER PROBLEMS WITH RAIN MIXING IN WITH TIMES. THIS WILL
KEEP ACCUMULATIONS DOWN...ESPECIALLY ALONG COASTAL ROCKINGHAM
COUNTY WHERE LITTLE SNOWFALL WILL OCCUR.

MINOR ADJUSTMENT MADE TO OTHER PRODUCTS INCLUDING SLOWING THE
TIMING OF THE HIGH POPS...BUT ALL IN ALL...GRIDS APPEAR TO BE IN
GOOD SHAPE. WILL LIKELY BE ISSUING A STATEMENT LATER THIS EVENING
TO ACCOUNT FOR THE TIMING AND PTYPE TRENDS...SINCE MUCH OF THIS
WILL AFFECT THE MORNING RUSH HOUR.

TIMING OF STEADY PCPN: LATEST HRRR RUN BRINGS THE INITIAL
PRECIPITATION INTO SOUTHERN NEW HAMPSHIRE AROUND 05Z OR 06Z WITH
THE HEAVIEST/STEADIEST PRECIPITATION ENTERING SOUTHERN NEW
HAMPSHIRE AROUND 09Z WHICH SEAMS REASONABLE AT THIS TIME.

PREV DISC...
A WEAK AND FAST MOVING SFC LOW MOVES NE FROM THE MID ATLANTIC
STATES TNGT THEN TRACKS TO THE NE JUST BEYOND THE GULF OF MAINE
FRIDAY...REACHING E OF THE HAGUE LINE LATE IN THE DAY. THE TRACK
IS ABOUT OVER THE BENCHMARK OF 40N 70W BUT DUE TO ITS RAPID
MOVEMENT AMOUNTS SHOULD REMAIN LIGHT. ALSO THE UPR LVL SUPPORT IS
LIMITED WITH A POSITIVE TILTED TROF AND A WEAK SFC LOW AS A
RESULT. STILL...THE MODELS FCST GENERALLY 2-4 INCHES OF SNOW WITH
THE HIGHEST AMOUNTS OVER SOUTHERN AREAS OF INTERIOR MAINE AND NH.
A FEW HIGHER AMOUNTS OF AROUND 5 INCHES CAN`T BE RULED OUT OVER
SOME AREAS OF HIGHER TERRAIN OVER SOUTHERN INTERIOR PORTIONS. THE
MOUNTAINS WILL SEE THE LEAST AMOUNT OF SNOWFALL WITH THIS SYSTEM
WITH ONLY AN INCH OR TWO EXPECTED.

THE TIMING OF THE PCPN IS FOR IT TO BEGIN OVER SOUTHWEST AREAS
AROUND OR SHORTLY AFTER MIDNIGHT BUT THEN RAPIDLY DEVELOP AND
OVERSPREAD THE REST OF THE REGION BY 10Z.

THE PRCP COULD START AS -RA OR MIXED -RASN OVER MORE SERN AND
COASTAL AREAS TNGT AS BOUNDARY LAYER UP TO 925 MB WILL HAVE TEMPS
AROUND OR JUST ABOVE FREEZING. EVENTUALLY PRCP CHANGES TO SN AS
TEMPS COOL DOWN. ON FRIDAY THE SN MAY MIX BACK TO RA IN THE MRNG OVER
THESE AREAS AS SFC AND BOUNDARY LAYER TEMPS AGAIN BEGIN TO CLIMB
INTO THE MID 30S.

&&

.SHORT TERM /FRIDAY NIGHT/...
CANADIAN HIGH PRES BUILDS SLOWLY SOUTH SO SOME CLEARING AND DRY CONDITIONS
EXPECTED WITH A RETURN TO MUCH COLDER TEMPS. USED A 50/50 BLEND
OF THE MAV/MET TEMPS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
QUIET WEATHER FOR THE MOST THROUGH THE PERIOD. PERHAPS A FEW SNOW
SHOWERS XMAS AFTERNOON AND EVENING WITH SHORT WAVE TROUGH. THIS
MAY START AS SOME LIGHT OCEAN ENHANCED SNOW ON THE MID COAST
DURING THE AFTERNOON ON XMAS. OTHERWISE...WE/LL HAVE TO WAIT UNTIL
THE 28TH OR SO FOR THE POSSIBILITY OF ANYTHING DECENT IN THE
PRECIPITATION DEPT...AND EVEN THEN THE MODELS HAVE BEEN
INCONSISTENT.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...VFR CONDS THIS EVENING WILL BECOME MVFR TO IFR AFTER
MIDNIGHT FROM SOUTH TO NORTH AS SNOW DEVELOPS AND SPREADS NORTH.
OVER SOUTHEAST NEW HAMPSHIRE THE PCPN MAY FALL AS A MIX AT TIMES.
CONDITIONS WILL GRADUALLY IMPROVE TO VFR FRIDAY AFTERNOON ALTHOUGH
SOME SCATTERED SNOW SHOWERS MAY BRIEFLY REDUCE CIGS/VSBYS TO MVFR.
VFR CONDS ACROSS ALL AREAS FRIDAY NIGHT.

LONG TERM...MAINLY VFR THROUGH TUESDAY. A PERIOD OF MVFR POSSIBLE
XMAS DAY AND NIGHT IN SNOW SHOWERS.

&&

.MARINE...
SHORT TERM...WINDS AND SEAS WILL REMAIN BELOW SCA LEVELS
TNGT AND FRIDAY AS A WEAK AND FAST MOVING COASTAL LOW PASSES SOUTH
OF NEW ENGLAND. CANADIAN HIGH PRESSURE TO OUR NORTH SLOWLY BUILDS
SOUTH ACROSS THE WATERS FRIDAY NIGHT.

LONG TERM...SCA CONDS POSSIBLE OVER THE WEEKEND.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$
CANNON






AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 420 PM EST WED DEC 21 2011

.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LIFT FROM THE OHIO VALLEY INTO THE
EASTERN GREAT LAKES THIS EVENING, BRINGING SHOWERS AND
UNSEASONABLY WARM TEMPERATURES TO THE AREA. HIGH PRESSURE WILL
THEN BRIEFLY BRING A BREAK FROM SHOWERS TONIGHT INTO EARLY
THURSDAY. THE NEXT LOW WILL APPROACH FROM THE SOUTHWEST AND RETURN
SHOWERS TO THE AREA FOR THURSDAY NIGHT.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
QUICK UPDATE TO BUMP UP WIND GUSTS AND ADD STRONGER THUNDERSTORM
WORDING ACROSS SOUTHEASTERN COUNTIES. EVEN OUTSIDE OF
SHOWERS...MANY LOCATIONS COULD SEE SOME 30-40 MPH WIND GUSTS AS
COLD FRONT APPROACHES FROM THE WEST. IN ADDITION...A LINE OF HEAVY
SHOWERS WITH ISOLATED THUNDERSTORMS HAS CONTINUED TO MOVE
EAST...AND CURRENTLY EXTENDS FROM IDI SOUTHWEST BACK TOWARDS HLG.
PREVIOUS DISCUSSION FOLLOWS.

THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A TROUGH WITH ITS
AXIS CENTERED ACROSS MICHIGAN. THE UPPER OHIO VALLEY IS IN A
SOUTHWESTERLY FLOW AHEAD OF THIS FEATURE. A PUNCH OF DRY MID-
LEVEL AIR IS ADVECTING THE AREA WITH THE 1000-850MB LAYER REMAINING
SATURATED. 850MB TEMPS OF AROUND 8C ARE INDICATIVE OF THE WARM AIR
ALOFT THAT HAS BUILT IN WITH THE WARM SECTOR. AT THE SURFACE, A
999MB LOW IS LOCATED ACROSS SOUTHERN ONTARIO WITH A WARM FRONT EXTENDING
EAST OF THIS FEATURE ACROSS LAKE ONTARIO. MEANWHILE, A COLD FRONT EXTENDS
SOUTHWEST OF THE LOW INTO THE CENTRAL GULF STATES. VIS AND WV SAT
IMAGERY INDICATE THE DRY SWATH IN OHIO AHEAD OF THE COLD FRONT. A
FEW NARROW LINE SEGMENTS OF SHALLOW CONVECTION HAVE DEVELOPED AND
ARE MOVING ACROSS EASTERN OHIO INTO WESTERN PA.

THIS EVENING...THE SURFACE LOW WILL MOVE NORTHEASTWARD, PROGGED TO
BE ACROSS LAKE ONTARIO BY 00Z. WINDS WILL GUST THIS AFTERNOON UP
TO 25 MPH AS THE PRESSURE GRADIENT TIGHTENS AND WINDS BRIEFLY MIX
DOWN WITH BREAKS IN CLOUD COVERAGE. WARM AIR ADVECTION WILL BE
ONGOING IN A STRONG SOUTHERLY FLOW AHEAD OF THE COLD FRONT. THUS,
HIGHS TODAY ARE A FEW DEGREES WARMER THAN LAMP GUIDANCE,
ESPECIALLY SOUTH OF PITTSBURGH. HIGHS TODAY WILL RANGE FROM THE
LOWER TO MID 60S ACROSS NORTH-CENTRAL WV TO THE MID 50S ALONG THE
I-80 CORRIDOR.

HRRR/WRF-NMM SUPPORT SCATTERED LOW- TOPPED CONVECTION IN OHIO
MOVING ACROSS THE AREA THROUGH THE EARLY EVENING. WEAK SBCAPE
(<500 J/KG) AND STRONG 0-6KM SHEAR (80KT) AHEAD OF A COLD FRONT
APPROACHING THE AREA CONTINUE TO SUPPORT THE CHANCE OF ISOLATED
THUNDERSTORMS. NOT OUT OF THE QUESTION SHOWERS OR THUNDERSTORMS
COULD BRING DOWN SOME STRONGER GUSTS TO THE SURFACE LATER THROUGH
00Z. THE STORM PREDICTION CENTER HAS PORTIONS OF EASTERN OHIO,
WESTERN PA, AND NORTH- CENTRAL WV IN A SLIGHT RISK INTO THE EARLY
EVENING.

TONIGHT...THE SURFACE LOW WILL PUSH INTO THE NORTHEAST AND ITS
ASSOCIATED COLD FRONT WILL SLIDE EAST OF THE AREA. ANY CONVECTION
WILL QUICKLY DIMINISH AND PUSH EAST OF THE AREA AFTER 00Z. THUS,
FORECAST IS DRY ACROSS THE AREA BY 03Z. COLD AIR ADVECTION WILL BE
WEAK IN THE WAKE OF THE FRONT, WITH A ZONAL MID-LEVEL FLOW IN THE
BEHIND THE LAGGING 500MB TROUGH. OVERNIGHT LOWS ARE A MAV/MET BLEND,
RANGING RANGE FROM THE UPPER 30S ACROSS THE I-80 CORRIDOR TO THE LOWER
40S ELSEWHERE.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
THERE IS NAM/GFS/ECMWF AGREEMENT THAT HIGH PRESSURE CENTERED ACROSS
WEST VIRGINIA EARLY ON THURSDAY WILL SHIFT EASTWARD OFF THE
MID-ATLANTIC COAST. A SURFACE LOW WILL MOVE FROM THE WESTERN GULF
INTO THE CENTRAL APPALACHIANS, RETURNING THE CHANCE OF RAIN SHOWERS
FOR AREAS SOUTH AND WEST OF PITTSBURGH BY THE LATE AFTERNOON
HOURS. SHOWERS WILL BECOME LIKELY THURSDAY NIGHT AS THE LOW MOVES
UP THE APPALACHIANS AND OFF THE JERSEY COAST BY FRIDAY MORNING. WITH
A SOUTHWESTERLY MID-LEVEL FLOW ALOFT, AND THE LOW ADVECTING WARMER
AIR INTO THE AREA, TEMPERATURES WILL BE AROUND 10 DEGREES ABOVE
NORMAL.

FRIDAY INTO SATURDAY...AS THE SURFACE LOW PULLS EAST OF THE AREA,
THE LOW-LEVEL FLOW WILL BECOME NORTHWESTERLY ON FRIDAY. COLD AIR
ADVECTION WILL PULL THE 1000-500MB 5400M THICKNESS LINE SOUTHWARD
WITH LINGERING RAIN AND SNOW SHOWER POSSIBLE FRIDAY MORNING BEFORE
1000-850MB MOISTURE SHIFTS EAST OF THE AREA. LIGHT ACCUMULATIONS OF
LESS THAN AN INCH HAVE BEEN INCLUDED FOR FOREST COUNTY. HIGH
PRESSURE WILL BEGIN TO BUILD IN FRIDAY AFTERNOON INTO CHRISTMAS
EVE, ALLOWING FOR A DRY FORECAST ACROSS MOST OF THE AREA THROUGH THIS
PERIOD. TEMPERATURES WILL BE AROUND 5 DEGREES ABOVE NORMAL.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
GENERALLY WENT WITH HPC GUIDANCE. KEPT LOW CHANCE POPS ACROSS WV ON
CHRISTMAS DAY WITH WEAK STORM MOVING THROUGH THE MID ATLANTIC
STATES. WEAK FRONT AND SHOT OF COLD AIR MOVING THROUGH THE GREAT
LAKES LATE CHRISTMAS DAY POSES CHANCE OF SNOW SHOWERS ACROSS
NORTHERN ZONES AND RIDGES LATE SUNDAY INTO EARLY MONDAY.

HIGH PRESSURE BUILDS ACROSS THE REGION MONDAY AND TUESDAY WITH
MODERATING TEMPERATURES.  GFS AND ECMWF DIFFER SIGNIFICANTLY IN
SURFACE FEATURES BY WEDNESDAY...BUT BOTH HAVE SOMETHING MOVING
THROUGH THE REGION SO CHANCE OF PRECIP SEEMS REASONABLE. SHOULD BE
RAIN INITIALLY...POSSIBLY MIXING WITH SNOW LATE IN THE DAY.

&&

.AVIATION /21Z WEDNESDAY THROUGH MONDAY/...
ALTHOUGH WIDESPREAD RAIN HAS MOVED EAST OF THE FORECAST
AREA...LINE OF HEAVIER SHOWERS HAS GONE THROUGH PIT...AGC...AND
HLG. EFFECTS WILL SOON BE FELT AT LBE AND MGW. EXPECT A BRIEF
PERIOD OF HEAVY RAIN AND GUSTY WINDS. THERE IS A SMALL GAP OF
ABOUT 100 MILES ACROSS EASTERN OHIO AND WESTERN PENNSYLVANIA WHERE
CEILINGS WILL SCATTER OUT...BEFORE MVFR STRATOCUMULUS MOVES BACK.
GUSTY SOUTHWEST WINDS TO 20KTS AHEAD OF FRONT WITH POSSIBLE GUST
TO 25 OR 30KTS WITH FRONTAL PASSAGE. WINDS WILL DIMINISH RAPIDLY
AFTER FRONTAL PASSAGE. STRATOCU MOVES OVER REGION AND REMAINS
THROUGH THURSDAY.

OUTLOOK...FRIDAY THROUGH MONDAY...
THE NEXT THE SERIES MOVES THROUGH THE UPPER OHIO VALLEY THURSDAY
NIGHT AND EARLY FRIDAY SPREADING RAIN AND IFR CONDITIONS ACROSS THE
REGION THURSDAY EVENING THROUGH EARLY FRIDAY MORNING. RAIN SHOULD BE
ENDING BY DAYBREAK FRIDAY WITH CONDITIONS IMPROVING TO MVFR FRIDAY
MORNING AND VFR DURING THE AFTERNOON. VFR CONDITIONS CONTINUE
THROUGH SATURDAY.

NEXT WAVE MOVES SOUTH OF THE REGION ON CHRISTMAS DAY WITH MVFR
CONDITIONS IN RAIN OR SNOW ACROSS WV CHRISTMAS DAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 328 PM EST WED DEC 21 2011

.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LIFT FROM THE OHIO VALLEY INTO THE
EASTERN GREAT LAKES THIS EVENING, BRINGING SHOWERS AND
UNSEASONABLY WARM TEMPERATURES TO THE AREA. HIGH PRESSURE WILL
THEN BRIEFLY BRING A BREAK FROM SHOWERS TONIGHT INTO EARLY
THURSDAY. THE NEXT LOW WILL APPROACH FROM THE SOUTHWEST AND RETURN
SHOWERS TO THE AREA FOR THURSDAY NIGHT.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A TROUGH WITH ITS
AXIS CENTERED ACROSS MICHIGAN. THE UPPER OHIO VALLEY IS IN A
SOUTHWESTERLY FLOW AHEAD OF THIS FEATURE. A PUNCH OF DRY MID-
LEVEL AIR IS ADVECTING THE AREA WITH THE 1000-850MB LAYER REMAINING
SATURATED. 850MB TEMPS OF AROUND 8C ARE INDICATIVE OF THE WARM AIR
ALOFT THAT HAS BUILT IN WITH THE WARM SECTOR. AT THE SURFACE, A
999MB LOW IS LOCATED ACROSS SOUTHERN ONTARIO WITH A WARM FRONT EXTENDING
EAST OF THIS FEATURE ACROSS LAKE ONTARIO. MEANWHILE, A COLD FRONT EXTENDS
SOUTHWEST OF THE LOW INTO THE CENTRAL GULF STATES. VIS AND WV SAT
IMAGERY INDICATE THE DRY SWATH IN OHIO AHEAD OF THE COLD FRONT. A
FEW NARROW LINE SEGMENTS OF SHALLOW CONVECTION HAVE DEVELOPED AND
ARE MOVING ACROSS EASTERN OHIO INTO WESTERN PA.

THIS EVENING...THE SURFACE LOW WILL TRANSVERSE NORTHEASTWARD,
PROGGED TO BE ACROSS LAKE ONTARIO BY 00Z. WINDS WILL GUST THIS
AFTERNOON UP TO 25 MPH AS THE PRESSURE GRADIENT TIGHTENS AND WINDS
BRIEFLY MIX DOWN WITH BREAKS IN CLOUD COVERAGE. WARM AIR ADVECTION
WILL BE ONGOING IN A STRONG SOUTHERLY FLOW AHEAD OF THE COLD
FRONT. THUS, HIGHS TODAY ARE A FEW DEGREES WARMER THAN LAMP
GUIDANCE, ESPECIALLY SOUTH OF PITTSBURGH. HIGHS TODAY WILL RANGE
FROM THE LOWER TO MID 60S ACROSS NORTH-CENTRAL WV TO THE MID 50S
ALONG THE I-80 CORRIDOR.

HRRR/WRF-NMM SUPPORT SCATTERED LOW- TOPPED CONVECTION IN OHIO
MOVING ACROSS THE AREA THROUGH THE EARLY EVENING. WEAK SBCAPE
(<500 J/KG) AND STRONG 0-6KM SHEAR (80KT) AHEAD OF A COLD FRONT
APPROACHING THE AREA CONTINUE TO SUPPORT THE CHANCE OF ISOLATED
THUNDERSTORMS. NOT OUT OF THE QUESTION SHOWERS OR THUNDERSTORMS
COULD BRING DOWN SOME STRONGER GUSTS TO THE SURFACE LATER THROUGH
00Z. THE STORM PREDICTION CENTER HAS PORTIONS OF EASTERN OHIO,
WESTERN PA, AND NORTH- CENTRAL WV IN A SLIGHT RISK INTO THE EARLY
EVENING.

TONIGHT...THE SURFACE LOW WILL PUSH INTO THE NORTHEAST AND ITS
ASSOCIATED COLD FRONT WILL SLIDE EAST OF THE AREA. ANY CONVECTION
WILL QUICKLY DIMINISH AND PUSH EAST OF THE AREA AFTER 00Z. THUS,
FORECAST IS DRY ACROSS THE AREA BY 03Z. COLD AIR ADVECTION WILL BE
WEAK IN THE WAKE OF THE FRONT, WITH A ZONAL MID-LEVEL FLOW IN THE
BEHIND THE LAGGING 500MB TROUGH. OVERNIGHT LOWS ARE A MAV/MET BLEND,
RANGING RANGE FROM THE UPPER 30S ACROSS THE I-80 CORRIDOR TO THE LOWER
40S ELSEWHERE.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
THERE IS NAM/GFS/ECMWF AGREEMENT THAT HIGH PRESSURE CENTERED ACROSS
WEST VIRGINIA EARLY ON THURSDAY WILL SHIFT EASTWARD OFF THE
MID-ATLANTIC COAST. A SURFACE LOW WILL MOVE FROM THE WESTERN GULF
INTO THE CENTRAL APPALACHIANS, RETURNING THE CHANCE OF RAIN SHOWERS
FOR AREAS SOUTH AND WEST OF PITTSBURGH BY THE LATE AFTERNOON
HOURS. SHOWERS WILL BECOME LIKELY THURSDAY NIGHT AS THE LOW MOVES
UP THE APPALACHIANS AND OFF THE JERSEY COAST BY FRIDAY MORNING. WITH
A SOUTHWESTERLY MID-LEVEL FLOW ALOFT, AND THE LOW ADVECTING WARMER
AIR INTO THE AREA, TEMPERATURES WILL BE AROUND 10 DEGREES ABOVE
NORMAL.

FRIDAY INTO SATURDAY...AS THE SURFACE LOW PULLS EAST OF THE AREA,
THE LOW-LEVEL FLOW WILL BECOME NORTHWESTERLY ON FRIDAY. COLD AIR
ADVECTION WILL PULL THE 1000-500MB 5400M THICKNESS LINE SOUTHWARD
WITH LINGERING RAIN AND SNOW SHOWER POSSIBLE FRIDAY MORNING BEFORE
1000-850MB MOISTURE SHIFTS EAST OF THE AREA. LIGHT ACCUMULATIONS OF
LESS THAN AN INCH HAVE BEEN INCLUDED FOR FOREST COUNTY. HIGH
PRESSURE WILL BEGIN TO BUILD IN FRIDAY AFTERNOON INTO CHRISTMAS
EVE, ALLOWING FOR A DRY FORECAST ACROSS MOST OF THE AREA THROUGH THIS
PERIOD. TEMPERATURES WILL BE AROUND 5 DEGREES ABOVE NORMAL.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
GENERALLY WENT WITH HPC GUIDANCE. KEPT LOW CHANCE POPS ACROSS WV ON
CHRISTMAS DAY WITH WEAK STORM MOVING THROUGH THE MID ATLANTIC
STATES. WEAK FRONT AND SHOT OF COLD AIR MOVING THROUGH THE GREAT
LAKES LATE CHRISTMAS DAY POSES CHANCE OF SNOW SHOWERS ACROSS
NORTHERN ZONES AND RIDGES LATE SUNDAY INTO EARLY MONDAY.

HIGH PRESSURE BUILDS ACROSS THE REGION MONDAY AND TUESDAY WITH
MODERATING TEMPERATURES.  GFS AND ECMWF DIFFER SIGNIFICANTLY IN
SURFACE FEATURES BY WEDNESDAY...BUT BOTH HAVE SOMETHING MOVING
THROUGH THE REGION SO CHANCE OF PRECIP SEEMS REASONABLE. SHOULD BE
RAIN INITIALLY...POSSIBLY MIXING WITH SNOW LATE IN THE DAY.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
AREA OF RAIN MOVING RAPIDLY EAST. BACK EDGE OF STEADY RAIN HAS MOVED
OUT OF OHIO AND WILL BE EAST OF CWA BETWEEN 18Z-19Z. RAIN IS
FOLLOWED BY AREA OF MVFR STRATUS. DRY SLOT WITH POSSIBLE CONVECTION
REACHES ZZV AROUND 18Z AND PIT BY 21Z. ISOLD SHOWERS ARE DEVELOPING
IN THE CLEARING AREA...BUT EXPECT THEY WILL DIE OUT FOR THE MOST
PART WITH LOSS OF DIURNAL HEATING BY THE TIME THEY REACH THE
MAJORITY OF TERMINALS IN CWA.  POSSIBLE EXCEPTION WOULD BE ZZV.
GUSTY SOUTHWEST WINDS TO 20KTS AHEAD OF FRONT WITH POSSIBLE GUST TO
25 OR 30KTS WITH FRONTAL PASSAGE.  WINDS WILL DIMINISH RAPIDLY AFTER
FRONTAL PASSAGE. STRATOCU MOVES OVER REGION AND REMAINS THROUGH
THURSDAY.

OUTLOOK...FRIDAY THROUGH MONDAY...
THE NEXT THE SERIES MOVES THROUGH THE UPPER OHIO VALLEY THURSDAY
NIGHT AND EARLY FRIDAY SPREADING RAIN AND IFR CONDITIONS ACROSS THE
REGION THURSDAY EVENING THROUGH EARLY FRIDAY MORNING. RAIN SHOULD BE
ENDING BY DAYBREAK FRIDAY WITH CONDITIONS IMPROVING TO MVFR FRIDAY
MORNING AND VFR DURING THE AFTERNOON. VFR CONDITIONS CONTINUE
THROUGH SATURDAY.

NEXT WAVE MOVES SOUTH OF THE REGION ON CHRISTMAS DAY WITH MVFR
CONDITIONS IN RAIN OR SNOW ACROSS WV CHRISTMAS DAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 107 PM EST WED DEC 21 2011

.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LIFT FROM THE OHIO VALLEY INTO THE
EASTERN GREAT LAKES THIS AFTERNOON, BRINGING SHOWERS AND
UNSEASONABLY WARM TEMPERATURES TO THE AREA. HIGH PRESSURE WILL
THEN BRIEFLY BRING A BREAK FROM SHOWERS TONIGHT INTO EARLY
THURSDAY. THE NEXT LOW WILL APPROACH FROM THE SOUTHWEST AND RETURN
SHOWERS TO THE AREA FOR THURSDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ACCOUNT
FOR THE LATEST TEMP TRENDS AND TO TIME SCATTERED CONVECTION
DEVELOPING IN OHIO AS IT CROSSES THE AREA.

THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A TROUGH WITH ITS AXIS
CENTERED ACROSS MICHIGAN. THE UPPER OHIO VALLEY IS IN A
SOUTHWESTERLY FLOW AHEAD OF THIS FEATURE. A PUNCH OF DRY MID-
LEVEL AIR IS ADVECTING THE AREA WITH 1000-850MB REMAINING
SATURATED. 850MB TEMPS OF AROUND 8C ARE INDICATIVE OF THE WARM AIR
ALOFT THAT HAS BUILT IN WITH THE WARM SECTOR. AT THE SURFACE, A
1000MB LOW IS LOCATED ACROSS EASTERN MICHIGAN WITH A WARM FRONT
EXTENDING EAST OF THIS FEATURE ACROSS LAKE ERIE. MEANWHILE, A COLD
FRONT EXTENDS SOUTHWEST OF THE LOW INTO THE CENTRAL GULF STATES.
VIS AND WV SAT IMAGERY INDICATE THE DRY SWATH IN OHIO AHEAD OF THE
COLD FRONT. A FEW NARROW LINE SEGMENTS OF SHALLOW CONVECTION ARE
DEVELOPING IN THIS AREA OF CLEARING.

THIS AFTERNOON...THE SURFACE LOW WILL TRANSVERSE NORTHEASTWARD,
PROGGED TO BE ACROSS LAKE ONTARIO BY 00Z. WINDS WILL GUST THIS
AFTERNOON UP TO 25 MPH AS THE PRESSURE GRADIENT TIGHTENS AND WINDS
BRIEFLY MIX DOWN WITH BREAKS IN CLOUD COVERAGE. WARM AIR ADVECTION
WILL BE ONGOING IN A STRONG SOUTHERLY FLOW AHEAD OF THE COLD
FRONT. THUS, HIGHS TODAY ARE A FEW DEGREES WARMER THAN LAMP
GUIDANCE, ESPECIALLY SOUTH OF PITTSBURGH. HIGHS TODAY WILL RANGE
FROM THE LOWER TO MID 60S ACROSS NORTH-CENTRAL WV TO THE MID 50S
ALONG THE I-80 CORRIDOR.

BEHIND THE INITIAL PRECIP SHIELD, MID-LEVEL DRYING HAS DIMINISHED
THE COVERAGE OF SHOWERS. HRRR/WRF-NMM SUPPORT SCATTERED LOW-
TOPPED CONVECTION IN OHIO SHIFTING EASTWARD INTO THE AREA FOR THE
LATE AFTERNOON AND EARLY EVENING. WEAK SBCAPE (<500 J/KG) AND
STRONG 0-6KM SHEAR (80KT) AHEAD OF A COLD FRONT APPROACHING THE
AREA CONTINUE TO SUPPORT THE CHANCE OF ISOLATED THUNDERSTORMS.
WITH THE SHALLOW NATURE OF THE CONVECTION, AM NOT ANTICIPATING
MUCH LIGHTNING. NOT OF THE QUESTION STRONGER SHOWERS OR
THUNDERSTORMS COULD BRING DOWN SOME STRONGER GUSTS TO THE SURFACE
LATER THIS AFTERNOON. THE STORM PREDICTION CENTER HAS UPGRADED
PORTIONS OF EASTERN OHIO, WESTERN PA, AND NORTH-CENTRAL WV TO A
SLIGHT RISK FOR THIS AFTERNOON.

TONIGHT...THE SURFACE LOW WILL PUSH INTO THE NORTHEAST AND ITS
ASSOCIATED COLD FRONT WILL SLIDE EAST OF THE AREA. ANY CONVECTION
WILL QUICKLY DIMINISH AND PUSH EAST OF THE AREA AFTER 00Z. THUS,
FORECAST IS DRY ACROSS THE AREA BY 03Z. COLD AIR ADVECTION WILL BE
WEAK IN THE WAKE OF THE FRONT, WITH A ZONAL MID-LEVEL FLOW IN THE
BEHIND THE LAGGING 500MB TROUGH. OVERNIGHT LOWS ARE A MAV/MET BLEND,
RANGING RANGE FROM THE UPPER 30S ACROSS THE I-80 CORRIDOR TO THE LOWER
40S ELSEWHERE.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
COLDER AIR WILL SETTLE INTO THE AREA THROUGH MOST OF THURSDAY.
THERE WILL BE A PERIOD OF DRY WEATHER THROUGH AT LEAST THE FIRST
HALF OF THU.

MODELS ARE IN GOOD AGREEMENT DEVELOPING ANOTHER SFC LOW WHICH WILL
MOVE UP THE APPALACHIANS THURSDAY AFTERNOON AND TURN TOWARD THE
EAST COAST THURSDAY NIGHT. WITH THE CURRENT FORECAST TRACK OF THE
SFC LOW, WARMER AIR WILL SURGE NORTHWARD AND KEEP THIS A RAIN
EVENT. HOWEVER, IF THE LOW WOULD TAKE A TRACK FURTHER TO THE EAST,
OR SHIFT TO THE EAST FASTER, LOCATIONS ACROSS THE FAR NORTH COULD
SEE MIXED PRECIPITATION.

THE SFC LOW WILL QUICKLY EXIT THE EAST COAST EARLY FRIDAY AND
COLDER AIR WILL WRAP IN BEHIND THE EXITING LOW. THERE MAY BE SOME
LINGER SHOWERS/SNOW SHOWERS IN THE CAA BEHIND THE LOW.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
VERY LOW CONFIDENCE IN THE LONG TERM, AS MEDIUM RANGE OP MODELS
ARE SHOWING LARGE VARIANCES BEGINNING ON SUNDAY.

12Z ECMWF IS SHOWING ANOTHER LARGE SFC LOW DEVELOPING OVER THE
GULF COAST SAT NIGHT AND RUSHING NORTHWARD ON SUNDAY.

HOWEVER, THE 00Z GFS DOES NOT DEVELOP THIS SFC SYSTEM, RATHER IT
BRINGS A WEAK COLD FRONT THROUGH ON SUNDAY. THE 12Z GEFS, 12Z
ECMWF ENSEMBLES, AND 12Z CMC ARE ALL SHOWING SOLUTIONS CLOSER TO
THAT OF THE GFS. SO FOR THE WEEKEND WILL LEAN CLOSER TO THE 00Z
GFS SOLUTION. THIS WOULD MEAN A COLDER AND DRIER FORECAST.

LOW CONFIDENCE CONTINUES FOR THE REMAINDER OF THE THE LONG TERM.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AREA OF RAIN MOVING RAPIDLY EAST. BACK EDGE OF STEADY RAIN HAS MOVED
OUT OF OHIO AND WILL BE EAST OF CWA BETWEEN 18Z-19Z. RAIN IS
FOLLOWED BY AREA OF MVFR STRATUS. DRY SLOT WITH POSSIBLE CONVECTION
REACHES ZZV AROUND 18Z AND PIT BY 21Z. ISOLD SHOWERS ARE DEVELOPING
IN THE CLEARING AREA...BUT EXPECT THEY WILL DIE OUT FOR THE MOST
PART WITH LOSS OF DIURNAL HEATING BY THE TIME THEY REACH THE
MAJORITY OF TERMINALS IN CWA.  POSSIBLE EXCEPTION WOULD BE ZZV.
GUSTY SOUTHWEST WINDS TO 20KTS AHEAD OF FRONT WITH POSSIBLE GUST TO
25 OR 30KTS WITH FRONTAL PASSAGE.  WINDS WILL DIMINISH RAPIDLY AFTER
FRONTAL PASSAGE. STRATOCU MOVES OVER REGION AND REMAINS THROUGH
THURSDAY.

OUTLOOK...FRIDAY THROUGH MONDAY...
THE NEXT THE SERIES MOVES THROUGH THE UPPER OHIO VALLEY THURSDAY
NIGHT AND EARLY FRIDAY SPREADING RAIN AND IFR CONDITIONS ACROSS THE
REGION THURSDAY EVENING THROUGH EARLY FRIDAY MORNING. RAIN SHOULD BE
ENDING BY DAYBREAK FRIDAY WITH CONDITIONS IMPROVING TO MVFR FRIDAY
MORNING AND VFR DURING THE AFTERNOON. VFR CONDITIONS CONTINUE
THROUGH SATURDAY.

NEXT WAVE MOVES SOUTH OF THE REGION ON CHRISTMAS DAY WITH MVFR
CONDITIONS IN RAIN OR SNOW ACROSS WV CHRISTMAS DAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 1048 AM EST WED DEC 21 2011

.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LIFT FROM THE OHIO VALLEY INTO THE
EASTERN GREAT LAKES TODAY, BRINGING RAIN AND UNSEASONABLY WARM
TEMPERATURES TO THE AREA. HIGH PRESSURE WILL THEN BRIEFLY BRING A
BREAK FROM SHOWERS TONIGHT INTO EARLY THURSDAY. THE NEXT LOW WILL
APPROACH FROM THE SOUTHWEST AND RETURN SHOWERS TO THE AREA FOR
THURSDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
15Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO PIN DOWN
THE MAIN PRE-FRONTAL PRECIPITATION SHIELD AS IT MOVES INTO THE UPPER
OHIO VALLEY LATE THIS MORNING INTO THE AFTERNOON HOURS. IN ADDITION,
TEMPS HAVE BEEN INCREASED, ESPECIALLY SOUTH OF PITTSBURGH.

THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A CLOSED LOW ACROSS
ILLINOIS WITH THE UPPER OHIO VALLEY IN A SOUTHWESTERLY FLOW AHEAD OF
THIS FEATURE. A SATURATED AREA OF 1000-500MB LAYER IS ADVECTING
ACROSS THE UPPER OHIO VALLEY WITH MID-LEVEL DRY AIR ADVECTION FROM
INDIANA INTO WESTERN OHIO. 850MB TEMPS OF 8C-10C ARE INDICATIVE OF
THE WARM AIR ALOFT THAT HAS BUILT IN WITH THE WARM SECTOR. AT THE
SURFACE, A 1004MB LOW IS LOCATED IN NW OHIO WITH A WARM FRONT
EXTENDING NORTHEAST OF THIS FEATURE ACROSS LAKE ERIE. MEANWHILE, A
COLD FRONT EXTENDS SOUTH OF THE LOW INTO THE CENTRAL GULF STATES.
AN AXIS OF PRE-FRONTAL RAIN IS SHIFTING INTO WESTERN PA AHEAD OF
THE LOW. BEHIND THIS AXIS THERE IS SOME CLEARING IN A DRY SWATH
AHEAD OF THE COLD FRONT.

TODAY...THE SURFACE LOW WILL TRANSVERSE NORTHEASTWARD, PROGGED TO BE
ACROSS LAKE ERIE BY 21Z. NAM12/RUC13 700MB OMEGA FIELDS INDICATE A
BROAD AREA OF FORCING FOR ASCENT ASSOCIATED WITH THE PRE-FRONTAL
AXIS OF RAIN MOVING MOSTLY EAST OF THE AREA BY THE LATE AFTERNOON.
AS RAIN MOVES THROUGH, A HALF OF AN INCH TO THREE QUARTERS OF AN
INCH OF PRECIPITATION CAN BE EXPECTED. WINDS WILL GUST THIS
AFTERNOON AT 20 TO 25 MPH AS PRESSURE GRADIENT TIGHTENS AND WINDS
BRIEFLY MIX DOWN WITH BREAKS IN CLOUD COVERAGE. WARM AIR ADVECTION
WILL BE ONGOING IN A STRONG SOUTHERLY FLOW AHEAD OF THE COLD
FRONT. THUS, HIGHS TODAY ARE A FEW DEGREES WARMER THAN A MAV/MET
BLEND, ESPECIALLY SOUTH OF PITTSBURGH. HIGHS TODAY WILL RANGE FROM
THE LOWER TO MID 60S ACROSS NORTH-CENTRAL WV TO THE MID 50S ALONG
THE I-80 CORRIDOR.

BEHIND THE INITIAL PRECIP SHIELD, MID-LEVEL DRYING WILL DIMINISH THE
COVERAGE OF SHOWERS. HRRR/WRF-NMM SUPPORT SCATTERED LOW-TOPPED
CONVECTION DEVELOPING IN THIS AREA FOR THE LATE AFTERNOON AND
EARLY EVENING. WEAK SBCAPE (<500 J/KG) AND STRONG 0-6KM SHEAR
(70KT) AHEAD OF A COLD FRONT APPROACHING THE AREA CONTINUE TO
SUPPORT THE CHANCE OF ISOLATED THUNDERSTORMS. NOT OF THE QUESTION
CONVECTION COULD BRING DOWN SOME STRONGER GUSTS LATER THIS
AFTERNOON. CONCUR WITH THE STORM PREDICTION CENTER WHICH HAS THE
AREA HIGHLIGHTED IN ITS GENERAL THUNDERSTORM OUTLOOK.

TONIGHT...THE SURFACE LOW WILL PUSH INTO THE NORTHEAST AND ITS
ASSOCIATED COLD FRONT WILL SLIDE EAST OF THE AREA. ANY CONVECTION
WILL QUICKLY DIMINISH AND PUSH EAST OF THE AREA AFTER 00Z. THUS,
FORECAST IS DRY ACROSS THE AREA BY 03Z. COLD AIR ADVECTION WILL BE
WEAK IN THE WAKE OF THE FRONT, WITH A ZONAL MID-LEVEL FLOW IN THE
BEHIND THE LAGGING 500MB TROUGH. OVERNIGHT LOWS ARE A MAV/MET BLEND,
RANGING RANGE FROM THE UPPER 30S ACROSS THE I-80 CORRIDOR TO THE LOWER
40S ELSEWHERE.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
COLDER AIR WILL SETTLE INTO THE AREA THROUGH MOST OF THURSDAY.
THERE WILL BE A PERIOD OF DRY WEATHER THROUGH AT LEAST THE FIRST
HALF OF THU.

MODELS ARE IN GOOD AGREEMENT DEVELOPING ANOTHER SFC LOW WHICH WILL
MOVE UP THE APPALACHIANS THURSDAY AFTERNOON AND TURN TOWARD THE
EAST COAST THURSDAY NIGHT. WITH THE CURRENT FORECAST TRACK OF THE
SFC LOW, WARMER AIR WILL SURGE NORTHWARD AND KEEP THIS A RAIN
EVENT. HOWEVER, IF THE LOW WOULD TAKE A TRACK FURTHER TO THE EAST,
OR SHIFT TO THE EAST FASTER, LOCATIONS ACROSS THE FAR NORTH COULD
SEE MIXED PRECIPITATION.

THE SFC LOW WILL QUICKLY EXIT THE EAST COAST EARLY FRIDAY AND
COLDER AIR WILL WRAP IN BEHIND THE EXITING LOW. THERE MAY BE SOME
LINGER SHOWERS/SNOW SHOWERS IN THE CAA BEHIND THE LOW.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
VERY LOW CONFIDENCE IN THE LONG TERM, AS MEDIUM RANGE OP MODELS
ARE SHOWING LARGE VARIANCES BEGINNING ON SUNDAY.

12Z ECMWF IS SHOWING ANOTHER LARGE SFC LOW DEVELOPING OVER THE
GULF COAST SAT NIGHT AND RUSHING NORTHWARD ON SUNDAY.

HOWEVER, THE 00Z GFS DOES NOT DEVELOP THIS SFC SYSTEM, RATHER IT
BRINGS A WEAK COLD FRONT THROUGH ON SUNDAY. THE 12Z GEFS, 12Z
ECMWF ENSEMBLES, AND 12Z CMC ARE ALL SHOWING SOLUTIONS CLOSER TO
THAT OF THE GFS. SO FOR THE WEEKEND WILL LEAN CLOSER TO THE 00Z
GFS SOLUTION. THIS WOULD MEAN A COLDER AND DRIER FORECAST.

LOW CONFIDENCE CONTINUES FOR THE REMAINDER OF THE THE LONG TERM.

&&

.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
AREA OF RAIN MOVING RAPIDLY EAST. BACK EDGE OF STEADY RAIN JUST
EAST OF ZZV AND SHOULD REACH PIT 1700-1730Z AND TO THE RIDGES
SHORTLY AFTER 18Z. RAIN IS FOLLOWED BY AREA OF MVFR STRATUS WITH
AREAS OF IFR CIGS. DRY SLOT WITH POSSIBLE CONVECTION REACHES ZZV
AROUND 18Z AND PIT BY 21Z. EXPECT FRONTAL PASSAGE AT AT ZZV AROUND
21Z, PIT AROUND 00Z AND TO THE RIDGES BY 03Z. MVFR CIGS WILL
OVERSPREAD AREA AFTER FRONTAL PASSAGE.

NAM MODEL PROFILES LIKEWISE SHOW FAST WINDS 1-4 KFT AGL TODAY. SO
HAVE ADDED LOW LEVEL WIND SHEAR THROUGH MID MORNING. AFTER THAT,
EXPECT SUFFICIENT VERTICAL MIXING IN THE SURFACE LAYER TO HAVE
THESE FAST WINDS PRODUCE GUSTS TO 20-25 KTS MIDDAY INTO EARLY
AFTERNOON. POST-SYSTEM STRONG PRESSURE RISES MAY CAUSE A PERIOD OF
WIND GUSTS TO ABOUT 30 KTS LATE THIS AFTERNOON INTO EARLY EVENING.


OUTLOOK...THURSDAY THROUGH SUNDAY...
MVFR STRATOCUMULUS CEILINGS CAN LINGER INTO DAYTIME THURSDAY. A
SERIES OF PASSING SYSTEMS WILL ALSO PROVIDE PERIODS OF PRECIPITATION
AND RESTRICTIONS THURSDAY NIGHT INTO MONDAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 953 AM EST WED DEC 21 2011

.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL LIFT FROM THE OHIO VALLEY INTO THE
EASTERN GREAT LAKES TODAY, BRINGING RAIN AND UNSEASONABLY WARM
TEMPERATURES TO THE AREA. HIGH PRESSURE WILL THEN BRIEFLY BRING A
BREAK FROM SHOWERS TONIGHT INTO EARLY THURSDAY. THE NEXT LOW WILL
APPROACH FROM THE SOUTHWEST AND RETURN SHOWERS TO THE AREA FOR
THURSDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
15Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO PIN DOWN
THE MAIN PRE-FRONTAL PRECIPITATION SHIELD AS IT MOVES INTO THE UPPER
OHIO VALLEY LATE THIS MORNING INTO THE AFTERNOON HOURS. IN ADDITION,
TEMPS HAVE BEEN INCREASED, ESPECIALLY SOUTH OF PITTSBURGH.

THE LATEST RUC MID-LEVEL ANALYSIS INDICATES A CLOSED LOW ACROSS
ILLINOIS WITH THE UPPER OHIO VALLEY IN A SOUTHWESTERLY FLOW AHEAD OF
THIS FEATURE. A SATURATED AREA OF 1000-500MB LAYER IS ADVECTING
ACROSS THE UPPER OHIO VALLEY WITH MID-LEVEL DRY AIR ADVECTION FROM
INDIANA INTO WESTERN OHIO. 850MB TEMPS OF 8C-10C ARE INDICATIVE OF
THE WARM AIR ALOFT THAT HAS BUILT IN WITH THE WARM SECTOR. AT THE
SURFACE, A 1004MB LOW IS LOCATED IN NW OHIO WITH A WARM FRONT
EXTENDING NORTHEAST OF THIS FEATURE ACROSS LAKE ERIE. MEANWHILE, A
COLD FRONT EXTENDS SOUTH OF THE LOW INTO THE CENTRAL GULF STATES.
AN AXIS OF PRE-FRONTAL RAIN IS SHIFTING INTO WESTERN PA AHEAD OF
THE LOW. BEHIND THIS AXIS THERE IS SOME CLEARING IN A DRY SWATH
AHEAD OF THE COLD FRONT.

TODAY...THE SURFACE LOW WILL TRANSVERSE NORTHEASTWARD, PROGGED TO BE
ACROSS LAKE ERIE BY 21Z. NAM12/RUC13 700MB OMEGA FIELDS INDICATE A
BROAD AREA OF FORCING FOR ASCENT ASSOCIATED WITH THE PRE-FRONTAL
AXIS OF RAIN MOVING MOSTLY EAST OF THE AREA BY THE LATE AFTERNOON.
AS RAIN MOVES THROUGH, A HALF OF AN INCH TO THREE QUARTERS OF AN
INCH OF PRECIPITATION CAN BE EXPECTED. WINDS WILL GUST THIS
AFTERNOON AT 20 TO 25 MPH AS PRESSURE GRADIENT TIGHTENS AND WINDS
BRIEFLY MIX DOWN WITH BREAKS IN CLOUD COVERAGE. WARM AIR ADVECTION
WILL BE ONGOING IN A STRONG SOUTHERLY FLOW AHEAD OF THE COLD
FRONT. THUS, HIGHS TODAY ARE A FEW DEGREES WARMER THAN A MAV/MET
BLEND, ESPECIALLY SOUTH OF PITTSBURGH. HIGHS TODAY WILL RANGE FROM
THE LOWER TO MID 60S ACROSS NORTH-CENTRAL WV TO THE MID 50S ALONG
THE I-80 CORRIDOR.

BEHIND THE INITIAL PRECIP SHIELD, MID-LEVEL DRYING WILL DIMINISH THE
COVERAGE OF SHOWERS. HRRR/WRF-NMM SUPPORT SCATTERED LOW-TOPPED
CONVECTION DEVELOPING IN THIS AREA FOR THE LATE AFTERNOON AND
EARLY EVENING. WEAK SBCAPE (<500 J/KG) AND STRONG 0-6KM SHEAR
(70KT) AHEAD OF A COLD FRONT APPROACHING THE AREA CONTINUE TO
SUPPORT THE CHANCE OF ISOLATED THUNDERSTORMS. NOT OF THE QUESTION
CONVECTION COULD BRING DOWN SOME STRONGER GUSTS LATER THIS
AFTERNOON. CONCUR WITH THE STORM PREDICTION CENTER WHICH HAS THE
AREA HIGHLIGHTED IN ITS GENERAL THUNDERSTORM OUTLOOK.

TONIGHT...THE SURFACE LOW WILL PUSH INTO THE NORTHEAST AND ITS
ASSOCIATED COLD FRONT WILL SLIDE EAST OF THE AREA. ANY CONVECTION
WILL QUICKLY DIMINISH AND PUSH EAST OF THE AREA AFTER 00Z. THUS,
FORECAST IS DRY ACROSS THE AREA BY 03Z. COLD AIR ADVECTION WILL BE
WEAK IN THE WAKE OF THE FRONT, WITH A ZONAL MID-LEVEL FLOW IN THE
BEHIND THE LAGGING 500MB TROUGH. OVERNIGHT LOWS ARE A MAV/MET BLEND,
RANGING RANGE FROM THE UPPER 30S ACROSS THE I-80 CORRIDOR TO THE LOWER
40S ELSEWHERE.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
COLDER AIR WILL SETTLE INTO THE AREA THROUGH MOST OF THURSDAY.
THERE WILL BE A PERIOD OF DRY WEATHER THROUGH AT LEAST THE FIRST
HALF OF THU.

MODELS ARE IN GOOD AGREEMENT DEVELOPING ANOTHER SFC LOW WHICH WILL
MOVE UP THE APPALACHIANS THURSDAY AFTERNOON AND TURN TOWARD THE
EAST COAST THURSDAY NIGHT. WITH THE CURRENT FORECAST TRACK OF THE
SFC LOW, WARMER AIR WILL SURGE NORTHWARD AND KEEP THIS A RAIN
EVENT. HOWEVER, IF THE LOW WOULD TAKE A TRACK FURTHER TO THE EAST,
OR SHIFT TO THE EAST FASTER, LOCATIONS ACROSS THE FAR NORTH COULD
SEE MIXED PRECIPITATION.

THE SFC LOW WILL QUICKLY EXIT THE EAST COAST EARLY FRIDAY AND
COLDER AIR WILL WRAP IN BEHIND THE EXITING LOW. THERE MAY BE SOME
LINGER SHOWERS/SNOW SHOWERS IN THE CAA BEHIND THE LOW.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
VERY LOW CONFIDENCE IN THE LONG TERM, AS MEDIUM RANGE OP MODELS
ARE SHOWING LARGE VARIANCES BEGINNING ON SUNDAY.

12Z ECMWF IS SHOWING ANOTHER LARGE SFC LOW DEVELOPING OVER THE
GULF COAST SAT NIGHT AND RUSHING NORTHWARD ON SUNDAY.

HOWEVER, THE 00Z GFS DOES NOT DEVELOP THIS SFC SYSTEM, RATHER IT
BRINGS A WEAK COLD FRONT THROUGH ON SUNDAY. THE 12Z GEFS, 12Z
ECMWF ENSEMBLES, AND 12Z CMC ARE ALL SHOWING SOLUTIONS CLOSER TO
THAT OF THE GFS. SO FOR THE WEEKEND WILL LEAN CLOSER TO THE 00Z
GFS SOLUTION. THIS WOULD MEAN A COLDER AND DRIER FORECAST.

LOW CONFIDENCE CONTINUES FOR THE REMAINDER OF THE THE LONG TERM.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
PER BLEND OF RECENT SURFACE AND RADAR DATA ALONG WITH SUITE OF HIGH
RESOLUTION MODELS, EXPECT FREQUENT SHOWERS WITH IFR RESTRICTIONS AT
TIMES TODAY, AS STRONG NORTHEASTWARD MOVING LOW PRESSURE CENTER
PASSES THROUGH OHIO THIS AFTERNOON. SHOWERS SHOULD END ABRUPTLY THIS
EVENING.

NAM MODEL PROFILES SHOW INSTABILITY CAN DEVELOP ACROSS THE UPPER
OHIO VALLEY THIS AFTERNOON, AS THE VALLEY WILL BE IN THE SO-CALLED
WARM SECTOR OF THE SYSTEM. SO WILL MENTION POSSIBLE THUNDER, WHICH
CONCURS WITH SPC GUIDANCE.

NAM MODEL PROFILES LIKEWISE SHOW FAST WINDS 1-4 KFT AGL TODAY. SO
HAVE ADDED LOW LEVEL WIND SHEAR THROUGH MID MORNING. AFTER THAT,
EXPECT SUFFICIENT VERTICAL MIXING IN THE SURFACE LAYER TO HAVE THESE
FAST WINDS PRODUCE GUSTS TO 20-25 KTS MIDDAY INTO EARLY AFTERNOON.
POST-SYSTEM STRONG PRESSURE RISES MAY CAUSE A PERIOD OF WIND GUSTS
TO ABOUT 30 KTS LATE THIS AFTERNOON INTO EARLY EVENING.

POST SYSTEM STRATOCUMULUS SHOULD YIELD MAINLY MVFR CEILINGS
TONIGHT, WITH PERHAPS A PERIOD OF IFR.

OUTLOOK...THURSDAY THROUGH SUNDAY...
MVFR STRATOCUMULUS CEILINGS CAN LINGER INTO DAYTIME THURSDAY. A
SERIES OF PASSING SYSTEMS WILL ALSO PROVIDE PERIODS OF PRECIPITATION
AND RESTRICTIONS THURSDAY NIGHT INTO MONDAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 359 AM EST WED DEC 21 2011

.SYNOPSIS...
A SERIES OF STORM SYSTEMS WILL BRING RAIN TO THE AREA THROUGH
EARLY FRIDAY. TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE
END OF THE WORK WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW PRESSURE WILL MOVE INTO THE UPPER OHIO VALLEY THIS AFTERNOON.
WARMER AIR AND MOISTURE WILL SURGE NORTHWARD, AHEAD OF THE SURFACE
SYSTEM. THIS WILL MEAN A DAY OF WELL ABOVE NORMAL TEMPS AND
WIDESPREAD RAIN. LATEST HRRR RUN IS SHOWING THE FIRST AREA OF RAIN
MOVING ACROSS THE NORTH AND WEST THROUGH MID-MORNING AND THEN
FILLING IN ACROSS THE REST OF THE REGION THERE AFTER.

MODELS ARE ALSO SHOWING SOME INSTABILITY RIGHT ALONG THE
ASSOCIATED COLD FRONT, WHICH WILL PASS THROUGH LATE THIS
AFTERNOON. IT IS POSSIBLE AN ISO STORM COULD DEVELOP LATE TODAY
WITH THE PASSAGE OF THE FRONT.

A STRONG LL JET, AHEAD OF THE SYSTEM, COULD PROVIDE SOME STRONGER
GUSTS TODAY. THE LIMITING FACTOR WILL BE THAT THE AREA WILL BE IN
THE WARM SECTOR, WHICH WILL INHIBIT MOST OF THE STRONGER WINDS
FROM MIXING DOWN. HOWEVER, IF CONVECTION DEVELOPS, THERE WILL BE A
THREAT FOR STRONG GUSTS WITH THE STORMS. THIS WILL NEED TO BE
MONITORED AS THE DAY PROGRESSES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
SFC LOW WILL MOVE QUICKLY INTO NEW ENGLAND THIS EVENING AND THE
COLD FRONT WILL MOVE INTO E PA. THIS WILL BRING AN END TO THE
SHOWERS, HOWEVER, THERE COULD BE A BRIEF PERIOD OF GUSTY WINDS
RIGHT BEHIND THE FRONT. MODELS ARE CONTINUING TO SHOW A STRONG LL
JET BEHIND THE FRONT THIS EVENING, AND IN THE CAA, IT IS POSSIBLE
THAT WINDS COULD MIX DOWN. LATEST NAM RUN IS SHOWING PRESSURE RISES
OF UP TO 5MB RIGHT BEHIND THE SFC BOUNDARY.

COLDER AIR WILL SETTLE INTO THE AREA TONIGHT AND THROUGH MOST OF
THURSDAY. THERE WILL BE A PERIOD OF DRY WEATHER THROUGH AT LEAST
THE FIRST HALF OF THU.

MODELS ARE IN GOOD AGREEMENT DEVELOPING ANOTHER SFC LOW WHICH WILL
MOVE UP THE APPALACHIANS THURSDAY AFTERNOON AND TURN TOWARD THE
EAST COAST THURSDAY NIGHT. WITH THE CURRENT FORECAST TRACK OF THE
SFC LOW, WARMER AIR WILL SURGE NORTHWARD AND KEEP THIS A RAIN
EVENT. HOWEVER, IF THE LOW WOULD TAKE A TRACK FURTHER TO THE EAST,
OR SHIFT TO THE EAST FASTER, LOCATIONS ACROSS THE FAR NORTH COULD
SEE MIXED PRECIPITATION.

THE SFC LOW WILL QUICKLY EXIT THE EAST COAST EARLY FRIDAY AND
COLDER AIR WILL WRAP IN BEHIND THE EXITING LOW. THERE MAY BE SOME
LINGER SHOWERS/SNOW SHOWERS IN THE CAA BEHIND THE LOW.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
VERY LOW CONFIDENCE IN THE LONG TERM, AS MEDIUM RANGE OP MODELS
ARE SHOWING LARGE VARIANCES BEGINNING ON SUNDAY.

12Z ECMWF IS SHOWING ANOTHER LARGE SFC LOW DEVELOPING OVER THE
GULF COAST SAT NIGHT AND RUSHING NORTHWARD ON SUNDAY.

HOWEVER, THE 00Z GFS DOES NOT DEVELOP THIS SFC SYSTEM, RATHER IT
BRINGS A WEAK COLD FRONT THROUGH ON SUNDAY. THE 12Z GEFS, 12Z
ECMWF ENSEMBLES, AND 12Z CMC ARE ALL SHOWING SOLUTIONS CLOSER TO
THAT OF THE GFS. SO FOR THE WEEKEND WILL LEAN CLOSER TO THE 00Z
GFS SOLUTION. THIS WOULD MEAN A COLDER AND DRIER FORECAST.

LOW CONFIDENCE CONTINUES FOR THE REMAINDER OF THE THE LONG TERM.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
PER BLEND OF RECENT SURFACE AND RADAR DATA ALONG WITH SUITE OF HIGH
RESOLUTION MODELS, EXPECT FREQUENT SHOWERS WITH IFR RESTRICTIONS AT
TIMES TODAY, AS STRONG NORTHEASTWARD MOVING LOW PRESSURE CENTER
PASSES THROUGH OHIO THIS AFTERNOON. SHOWERS SHOULD END ABRUPTLY THIS
EVENING.

NAM MODEL PROFILES SHOW INSTABILITY CAN DEVELOP ACROSS THE UPPER
OHIO VALLEY THIS AFTERNOON AS IN THE SO-CALLED WARM SECTOR OF THE
SYSTEM. SO WILL MENTION POSSIBLE THUNDER, WHICH CONCURS WITH SPC
GUIDANCE.

NAM MODEL PROFILES LIKEWISE SHOW FAST WINDS 2-4 KFT AGL TODAY. DID
NOT THINK WINDS QUITE FAST ENOUGH TO MENTION LOW LEVEL WIND SHEAR
THIS MORNING. DID ADD WIND GUSTS TO 20-25 KTS LATER TODAY, BUT MAY
HAVE TO MAKE HIGHER. LIKEWISE, POST-SYSTEM STRONG PRESSURE RISES MAY
CAUSE A PERIOD OF GUSTY WINDS TONIGHT.

POST SYSTEM STRATOCUMULUS SHOULD YIELD MVFR CEILINGS LATE TONIGHT,
AND PERHAPS A PERIOD OF IFR.

OUTLOOK...THURSDAY THROUGH SUNDAY...
MVFR STRATOCUMULUS CEILINGS CAN LINGER INTO DAYTIME THURSDAY. A
SERIES OF PASSING SYSTEMS WILL ALSO PROVIDE PERIODS OF PRECIPITATION
AND RESTRICTIONS THURSDAY NIGHT INTO MONDAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION...UPDATED

NWS GLASGOW MT

 727 PM MST THU DEC 22 2011

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...

EARLY UPDATE TONIGHT TO ADD FLURRIES INTO THE GRIDS GIVEN CURRENT
RADAR REFLECTIVITY TRENDS. IT SEEMS THAT SOME
FLURRIES...COINCIDENT WITH THE PASSAGE OF A WEAK SURFACE TROUGH
AXIS...HAS MATERIALIZED OVER OUR NORTHEASTERN ZONES. NOT SURE
IF ANY OF IT IS ACTUALLY REACHING THE GROUND...BUT FEEL LIKE IT IS
WORTH INCLUDING IN THE GRIDS FOR NOW. HRRR MODEL HAS GRABBED ONTO
IT EVEN THOUGH OTHER OPERATIONAL MODELS HAVE IT NOWHERE NEAR HERE. BMICKELSON

PREVIOUS SHORT TERM DISCUSSION...SYNOPTIC SET UP... A COLD CORE
LOW SETS OVER THE HUDSON BAY AND NORTHERN QUEBEC. A TROUGH EXTENDS
FROM THIS LOW SOUTH AND WEST INTO THE GREAT LAKES... DAKOTAS...
AND CENTRAL ROCKIES. A RIDGE IS BUILDING IN OVER BRITISH
COLUMBIA... THE PACIFIC NORTHWEST... AND ONTO THE NORTHERN HIGH
PLAINS. FURTHER WEST AND NORTH ANOTHER COLD TROUGH EXISTS OVER THE
BERING STRAIGHT.

THIS EVENING INTO TONIGHT... A CHINOOK WITH DOWN SLOPE WINDS IS
BEGINNING TO TAKE PLACE OVER CENTRAL ALBERTA AND SHOULD SLOWLY
BEGIN TO WHITTLE ITS WAY DOWN SOUTH AS THE RIDGE OVER BRITISH
COLUMBIA AND THE PACIFIC NORTHWEST EXPANDS. SNOW COVER SHOULD
BEGIN TO SLOWLY DISAPPEAR LATE THIS AFTERNOON INTO TOMORROW.
OVERNIGHT LOWS THIS COMING NIGHT MAY ALSO BE A LITTLE WARMER THAN
LAST WITH THE CHINOOK ARCH CLOUDS SETTING UP ACROSS THE REGION
THIS EVENING.

FRIDAY THROUGH SATURDAY... WEAK DOWNSLOPE IS ANTICIPATED BOTH
FRIDAY AND SATURDAY WITH A SMALL WEAK COLD PUSH THROUGH THE
DAKOTAS FRIDAY NIGHT. MOST PLACES SHOULD NOT BE IMPACTED MUCH BY
THE COLD PUSH EXCEPT FOR MAYBE FAR NORTHEASTERN PORTIONS OF THE
CWA SUCH AS WESTBY AND PLENTYWOOD IN SHERIDAN COUNTY. OTHERWISE
EXPECT TEMPERATURES TO MODERATE TO ABOVE NORMAL WITH DRY
CONDITIONS. GAH

.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
OVERALL TREND OF THE EXTENDED IS FOR A HIGH AMPLITUDE RIDGE OVER
THE REGION ON CHRISTMAS DAY TO BREAK DOWN INTO FAST ZONAL FLOW.
SEVERAL SHORTWAVES PUSH THROUGH THE NORTHERN ROCKIES DURING THE
WEEK BUT QUESTION IS HOW MUCH MOISTURE MAKES IT EAST OF THE
DIVIDE. MODELS ARE VERY SLOW TO BRING THE MOISTURE EAST AND WITH
STRONG DOWNSLOPE FLOW HAVE KEPT POPS CONFINED TO THE END OF THE
FORECAST PERIOD. EBERT

PREVIOUS LONG TERM DISCUSSION...THE EXTENDED BEGINS WITH THE
COASTAL RIDGE MOVING OVER THE REGION WITH WARM TEMPERATURES ALOFT
AND DRY CONDITIONS. THE EXITING OF THIS RIDGE INTRODUCES A CHANGE
IN THE UPPER LEVEL PATTERN FOR THE REGION. ON SUNDAY THE RIDGE
DOMINATES...THEN ZONAL WESTERLY FLOW TAKES OVER THE REMAINDER OF
THE EXTENDED PERIOD WHICH IS PRETTY CONSISTENT BETWEEN THE MODELS.
HOWEVER...FAST ZONAL FLOW DOES LEAD TO MODEL DIFFERENCES WITH
SPECIFIC FEATURES WHICH LEADS TO A LOWER CONFIDENCE ON THE
FORECAST. THE TREND OF WARMER THAN NORMAL TEMPERATURES AND BELOW
NORMAL PRECIPITATION LOOKS GOOD.

GOING TO KEEP THE FORECAST DRY THROUGH DAY 7 OR WEDNESDAY AND EVEN
THEN ITS A VERY LOW PROBABILITY EVENT FOR NORTHEAST MONTANA ON
VERY LOW QPF. THE WESTERN MOUNTAINS OF A STATE WILL SEE
PRECIPITATION IN THIS PATTERN...HOWEVER HERE ON THE LEE SIDE WE
CAN EXPECT SOME CHINOOK CONDITIONS AT TIMES TO KEEP THINGS FAIRLY
DRY. DAY 7 AND 8 HAS THE REMOTE POSSIBILITY OF PRODUCING SOME
LIGHT PRECIPITATION. GOING TO KEEP WITH THE FROZEN TYPE OF
PRECIPITATION AT THIS TIME...HOWEVER THE TEMPERATURES IN THE UPPER
ATMOSPHERE ON ALL MODELS DO SUGGEST OTHER FORMS OF PRECIPITATION
ARE POSSIBLE. DUE THE VERY LOW PROBABILITY OF THE EVENT WILL NOT
INTRODUCE FREEZING PRECIPITATION INTO THE FORECAST AT THIS TIME. PROTON


&&

.AVIATION...
VFR. MID LEVEL CLOUDS MOVING THROUGH THE AREA TONIGHT COULD
PRODUCE A BRIEF FLURRY...OTHERWISE IT WILL REMAIN DRY WITH LIGHT
WINDS IN THE VALLEYS AND SOUTHWEST WINDS 10-15KTS ON THE RIDGE
TOPS. TFJ/RAE


&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

WEATHER.GOV/GLASGOW






AREA FORECAST DISCUSSION

NWS BUFFALO NY

 328 AM EST WED DEC 21 2011

.SYNOPSIS...
HIGH PRESSURE ACROSS NEW YORK STATE WILL MOVE TO THE EAST OF THE
REGION TONIGHT. MEANWHILE...LOW PRESSURE MOVING OUT OF THE SOUTHERN
PLAINS WILL PUSH A WARM FRONT NORTH TOWARD THE LOWER LAKES LATER
TONIGHT AND WEDNESDAY. THE SOUTHERLY WINDS TO THE WEST OF THE HIGH
PRESSURE CENTER AND THE PASSAGE OF THE WARM FRONT WILL BRING WARMER
TEMPERATURES AND RAIN... WHICH COULD BEGIN AS A WINTRY MIX OF
PRECIPITATION ACROSS THE TUG HILL REGION.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE 00Z BUF SOUNDING SHOWS AN 850 MB TEMP OF -5C...WHICH IS 3
DEGREES C COLDER THAN NEARLY ALL MODEL GUIDANCE. THIS IS LIKELY
DUE TO THE SHARPNESS OF THE BOUNDARY ALOFT...WHICH IS NOT BEING
SUFFICIENTLY RESOLVED BY THE MODELS. AT 1000 PM...RADAR SHOWS A
LINE LIFTING ACROSS CHAUTAUQUA COUNTY. THIS IS LIKELY THE LEADING
EDGE OF SIGNIFICANT WARM AIR ADVECTION.

BASED ON THIS...EXPECT THIS LINE IS IS WHAT WILL WARM TEMPERATURES
ALOFT ENOUGH TO SUPPORT RAIN. RETURNS ON THIS ARE QUITE
MEAGER...AND HAVE OPTED TO DOWNGRADE THIS TO JUST FLURRIES AS THIS
MOVES THROUGH SINCE IT IS LESS LIKELY TO BE MEASURABLE. THE 00Z BUFFALO
SOUNDING SUGGESTS PRECIPITATION WILL START AS A BRIEF PERIOD OF
SNOW OR SNOW AND RAIN MIXED. BEHIND THIS...TEMPERATURES ALOFT
WILL BE TOO WARM TO SUPPORT SNOW...WITH THIS LINE EXPECTED TO
CONTINUE TO LIFT NORTHWARD OVERNIGHT.

DESPITE THE BRIEF PERIOD OF MIXED PRECIPITATION AT THE ONSET...IT
DOES APPEAR SURFACE TEMPERATURES WILL CONTINUE TO GRADUALLY WARM
OVERNIGHT. WILL CONTINUE TO WATCH THIS CLOSELY...BECAUSE AS THIS
LIGHT BAND MOVES ACROSS...TEMPERATURES ARE FORECAST TO BE JUST A
COUPLE DEGREES ABOVE FREEZING...WHICH IS A TAD CLOSE FOR COMFORT.

EAST OF LAKE ONTARIO CLEARED OUT THIS EVENING...WHICH ALLOWED
TEMPERATURES TO DROP INTO THE UPPER TEENS IN MANY SPOTS. BECAUSE
OF THIS...NOW HAVE THE ADVISORY FOR JEFFERSON COUNTY AS WELL...AND
UNTIL 1000 AM. FROZEN QPFS WILL NOT BE MUCH. LOOKING FOR JUST A
LIGHT GLAZE OF ICE IF ANYTHING...BUT IT DOES NOT TAKE MUCH ICE TO
MAKE THINGS SLICK.

OTHERWISE...EXPECT AREAS OF FOG TO DEVELOP BEHIND THIS...WITH JHW
ALREADY DOWN TO A HALF MILE. FOG WILL SPREAD ACROSS ALL OF THE
SOUTHERN TIER...BUT THE SE DOWNSLOPE FLOW SHOULD LIMIT FOG NORTH
OF THE I-90 THRUWAY.

WARM AIR OVERSPREADS THE ENTIRE FORECAST AREA BY MID MORNING ON
WEDNESDAY AND THE STEADIER RAINS WILL FOLLOW CLOSELY. RAINFALL
TOTALS WILL RANGE FROM A THIRD TO A HALF INCH FROM LATE MORNING
THROUGH WEDNESDAY EVENING. THIS SAID...LOCALIZED AMOUNTS TO AN
INCH ARE POSSIBLE...ESPECIALLY SOUTH OF THE THRUWAY...WHERE BOTH
THE NAM AND HRRR BRING IN THE BEST QPFS. WOULD NOT BE SURPRISED TO
HEAR A RUMBLE OF THUNDER...GIVEN A MODEST AMOUNT OF ELEVATED CAPE.
WITH NO LIGHTNING STRIKES UPSTREAM...CARRY ONLY ISOLATED THUNDER
IN PORTIONS OF THE SOUTHERN TIER WEDNESDAY MORNING.

TEMPS WILL TOP OUT IN THE LOWER TO MID 40S ACROSS THE EASTERN LAKE
ONTARIO REGION WITH MID 40S TO LOW 50S FOR THE REMAINDER OF THE
FORECAST AREA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
THE POTENT UPPER WAVE SHIFTS TO THE EAST AT THE START OF THE
PERIOD...AS WEAK SHORTWAVE RIDGING DEVELOPS ACROSS WESTERN NEW
YORK. THIS SHOULD PROVIDE A BRIEF BREAK IN PRECIPITATION FOR MOST
OF THE AREA. MILD DAY EXPECTED THURSDAY AFTERNOON WITH TEMPERATURES
RANGING FROM THE UPPER 30S ACROSS PARTS OF THE NORTH COUNTRY TO
THE MID AND UPPER 40S IN THE GENESEE VALLEY AND SOUTH SHORE OF
LAKE ONTARIO.

LATEST MODELS ARE IN SIMILAR AGREEMENT DEVELOPING ANOTHER SURFACE
WAVE WHICH WILL MOVE UP THE APPALACHIANS THURSDAY AFTERNOON AND
TURN TOWARD THE EAST COAST THURSDAY NIGHT. THIS FORECAST TRACK
WOULD FAVOR KEEPING THE REGION WELL INTO THE COLD AIR WITH THE
NORTHERN FRINGE OF PRECIPITATION MORE THAN LIKELY FALLING AS SNOW
IN THE THURSDAY NIGHT THROUGH FRIDAY TIME FRAME. THERMAL PROFILES
WOULD SUGGEST THAT PRECIPITATION ONSET COULD BE IN THE FORM OF
RAIN BEFORE ATMOSPHERIC COLUMN COMPLETELY COOLS. TIME HEIGHT
CROSS SECTIONS REVEALING DEEP SATURATION AMID THE STRONG FORCING.
295K ISENTROPIC SURFACE SHOWS BEST LIFT FROM THE SOUTHERN TIER
SOUTHWARD INTO PENNSYLVANIA. THE HIGH SPOTS ALONG THE SOUTHERN
TIER LIKELY HAVE THE BEST POTENTIAL FOR ACCUMULATING SNOWS. A 1-3
INCH POTENTIAL LOOKS REASONABLE BASED ON CURRENT FORECAST TRACK OF
THE SURFACE WAVE.

THE SURFACE WAVE WILL PUSH EAST OF THE AREA BY LATE FRIDAY WITH
COLDER AIR WRAPPING IN BRINGING THE POTENTIAL FOR SOME LIMITED
LAKE RESPONSE.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
A SOMEWHAT AMPLIFIED +PNA PATTERN ACROSS THE LOWER 48 AT THE START
OF THIS PERIOD WILL QUICKLY BREAK DOWN INTO A LOW AMPLITUDE PACIFIC
FLOW AS MID LATITUDE BLOCKING WILL GENERALLY REMAIN ABSENT ACROSS
THE NORTHERN HEMISPHERE. MEDIUM RANGE GUIDANCE WAS SUGGESTING THAT
SOME BLOCKING COULD DEVELOP IN PREVIOUS MODEL RUNS...BUT THAT TREND
HAS SINCE BEEN REVERSED. THIS WILL RESULT IN TEMPERATURES AVERAGING
NEAR TO ABOVE NORMAL...ALTHOUGH THERE WILL BE BRIEF PERIODS WHEN IT
WILL BE SEASONABLY CHILLY.

THE BIGGEST QUESTION FOR MANY DURING THIS PERIOD IS...WILL THERE
ENOUGH SNOW FOR A WHITE CHRISTMAS? THAT MAY LARGELY DEPEND ON YOUR
SPECIFIC DEFINITION OF A WHITE CHRISTMAS...AS SIGNIFICANT SNOWFALL
FOR OUR REGION IS NOT CURRENTLY IN THE MAKING.

FOR SATURDAY...A POTENT SHORTWAVE IN THE NORTHERN BRANCH WILL BRUSH
BY TO OUR NORTH. THIS WILL BRING US THE CHANCE FOR SOME LIGHT SNOW
SHOWERS...BUT WITH A HIGHLY SHEAR AIRMASS IN ITS WAKE...ASSISTANCE
FROM THE LAKES (IE. LAKE EFFECT) IS NOT ANTICIPATED. THIS SHOULD
KEEP THE SNOW FROM MEASURING MORE THAN A COVERING.

THE MOST SIGNIFICANT WEATHER FEATURE OF THIS PERIOD WILL THEN TAKE
AIM ON THE MID ATLANTIC AND NORTHEAST COAST FOR CHRISTMAS DAY AND
NIGHT. THE MEDIUM RANGE GUIDANCE PACKAGES HAVE NOT BEEN IN SYNC WITH
THIS FEATURE FOR THE PAST SEVERAL RUNS...AND THAT FACT REMAINS THE
SAME AS THE GFS NEVER REALLY GENERATES ANYTHING AT THE SFC WHILE THE
USUALLY MORE TRUSTWORTHY ECMWF DEPICTS A COASTAL LOW. IT IS THIS
LATTER SOLUTION THAT SUGGESTS THE BACK-EDGE OF THE SYNOPTIC SNOW
SHIELD WILL LIFT UP ACROSS OUR AREA SUNDAY NIGHT. WILL RAISE POPS TO
40 TO COVER FOR THIS POTENTIAL. IF THE STORM SYSTEM WORKS OUT
EXACTLY AS DEPICTED...THEN THERE COULD BE SUB-ADVISORY CRITERIA SNOW
ACCUMS SOUTH AND EAST OF BUFFALO...BUT FROM THIS RANGE IT WOULD NOT
BE PRUDENT TO PUT A LOT OF CONFIDENCE INTO THAT.

A SEASONABLY COLD NORTHWEST FLOW IN ITS WAKE WILL COMBINE WITH A H5
TROUGH TO BRING US THE CHANCE FOR SNOW SHOWERS AND SOME LAKE
ENHANCEMENT MONDAY AND MONDAY NIGHT...THEN WARMING ALOFT AND THE
PROGRESSION OF A H5 RIDGE SHOULD ENCOURAGE FAIR AND MILDER WEATHER
FOR TUESDAY INTO MID WEEK.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
THE LEADING EDGE OF WARM AIR ADVECTION ALOFT IS GRADUALLY
CROSSING BUF AT 05Z. THIS MAY CAUSE A PERIOD OF LOWER CIGS...BUT
UPSTREAM OBS SUGGEST THIS WILL BE TEMPORARY. THE SE DOWNSLOPE
FLOW SHOULD KEEP BUF/IAG/ROC MAINLY MVFR TIL WEDNESDAY MORNING.

THE STEADY MODERATE TO POSSIBLY HEAVY RAIN WILL ENTER FROM SW TO
NE WEDNESDAY MORNING. THIS WILL LOWER CIGS...WITH A FAIR PERIOD OF
LIFR-IFR CONDITIONS EXPECTED. CONDITIONS WILL NOT IMPROVE UNTIL
THE LOW LIFTS ACROSS THE LAKES AND INCREASES WINDS AND
MIXING...WHICH WILL EVENTUALLY DRY THINGS OUT.

OUTLOOK...
WEDNESDAY NIGHT...MVFR/IFR WITH RAIN.
THURSDAY...MAINLY VFR.
THURSDAY NIGHT...CHC LIGHT SNOW OR RAIN
ESPECIALLY TOWARDS THE SOUTH AND EAST.
FRIDAY AND SATURDAY...MAINLY VFR CHC SNOW SHOWERS.
SUNDAY...MAINLY VFR IN SCTD SNOW SHOWERS.

&&

.MARINE...
HIGH PRESSURE ACROSS NEW YORK STATE TODAY WILL MOVE TO THE EAST OF
THE REGION TONIGHT. SOUTHERLY WINDS WILL INCREASE TONIGHT AND
WEDNESDAY AS A WARM FRONT LIFTS NORTH TOWARD THE LOWER LAKES...THE
ATTENDANT LOW AND COLD FRONT WILL CROSS THE LAKES ON WEDNESDAY NIGHT
WITH INCREASING WESTERLY WINDS AND WAVES BUILDING TO SMALL CRAFT
ADVISORY CRITERIA GENERALLY FROM WEDNESDAY EVENING THROUGH MID
MORNING ON THURSDAY.

&&

.CLIMATE...
THE WINTER OF 2011-12 HAS STARTED SLOW IN THE SNOWFALL CATEGORY
ACROSS WESTERN AND CENTRAL NEW YORK. THROUGH DECEMBER 19TH...THE
CURRENT SNOW THIS SEASON OF 3.0 INCHES (BUFFALO) AND 2.1
INCHES(ROCHESTER) ARE WELL BELOW NORMAL THUS FAR. THERE HAVE BEEN
SEVERAL YEARS THAT HAVE HAD SIMILAR STARTS THOUGH. BELOW IS A LIST
OF THE TOP LEAST AMOUNT OF SNOW IN BOTH CITIES...MEASURED AT THE
RESPECTIVE AIRPORTS...THROUGH AND INCLUDING CHRISTMAS EVE.

BUFFALO

1   3.0     2011
2   3.1     1998
3   3.3     1931
4   3.6     1896
5   4.3     1918
...
10  6.5     1888
15  7.8     1891

***NORMAL THROUGH DECEMBER 24TH 29.1***


ROCHESTER

1   2.1     2011
2   2.6     1939
3   3.7     2001
4   3.8     1877
5   4.2     2006
...
10  6.2     1998
15  7.8     1940

***NORMAL THROUGH DECEMBER 24TH 23.5***

SNOWFALL RECORDS GO BACK TO THE WINTER OF 1884-85.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     NYZ006>008.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM EST
         THURSDAY FOR LEZ020-040-041.
         SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM
         EST THURSDAY FOR LOZ043>045.
         SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 8 AM EST
         THURSDAY FOR LOZ042.

&&

$$

SYNOPSIS...WCH
NEAR TERM...APFFEL/WCH
SHORT TERM...TMA
LONG TERM...RSH
AVIATION...APFFEL
MARINE...APFFEL/WCH
CLIMATE...THOMAS





AREA FORECAST DISCUSSION

NWS BUFFALO NY

 1156 PM EST TUE DEC 20 2011

.SYNOPSIS...
HIGH PRESSURE ACROSS NEW YORK STATE WILL MOVE TO THE EAST OF THE
REGION TONIGHT. MEANWHILE...LOW PRESSURE MOVING OUT OF THE SOUTHERN
PLAINS WILL PUSH A WARM FRONT NORTH TOWARD THE LOWER LAKES LATER
TONIGHT AND WEDNESDAY. THE SOUTHERLY WINDS TO THE WEST OF THE HIGH
PRESSURE CENTER AND THE PASSAGE OF THE WARM FRONT WILL BRING WARMER
TEMPERATURES AND RAIN... WHICH COULD BEGIN AS A WINTRY MIX OF
PRECIPITATION ACROSS THE TUG HILL REGION.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
THE 00Z BUF SOUNDING SHOWS AN 850 MB TEMP OF -5C...WHICH IS 3
DEGREES C COLDER THAN NEARLY ALL MODEL GUIDANCE. THIS IS LIKELY
DUE TO THE SHARPNESS OF THE BOUNDARY ALOFT...WHICH IS NOT BEING
SUFFICIENTLY RESOLVED BY THE MODELS. AT 1000 PM...RADAR SHOWS A
LINE LIFTING ACROSS CHAUTAUQUA COUNTY. THIS IS LIKELY THE LEADING
EDGE OF SIGNIFICANT WARM AIR ADVECTION.

BASED ON THIS...EXPECT THIS LINE IS IS WHAT WILL WARM TEMPERATURES
ALOFT ENOUGH TO SUPPORT RAIN. RETURNS ON THIS ARE QUITE
MEAGER...AND HAVE OPTED TO DOWNGRADE THIS TO JUST FLURRIES AS THIS
MOVES THROUGH SINCE IT IS LESS LIKELY TO BE MEASURABLE. THE 00Z BUFFALO
SOUNDING SUGGESTS PRECIPITATION WILL START AS A BRIEF PERIOD OF
SNOW OR SNOW AND RAIN MIXED. BEHIND THIS...TEMPERATURES ALOFT
WILL BE TOO WARM TO SUPPORT SNOW...WITH THIS LINE EXPECTED TO
CONTINUE TO LIFT NORTHWARD OVERNIGHT.

DESPITE THE BRIEF PERIOD OF MIXED PRECIPITATION AT THE ONSET...IT
DOES APPEAR SURFACE TEMPERATURES WILL CONTINUE TO GRADUALLY WARM
OVERNIGHT. WILL CONTINUE TO WATCH THIS CLOSELY...BECAUSE AS THIS
LIGHT BAND MOVES ACROSS...TEMPERATURES ARE FORECAST TO BE JUST A
COUPLE DEGREES ABOVE FREEZING...WHICH IS A TAD CLOSE FOR COMFORT.

EAST OF LAKE ONTARIO CLEARED OUT THIS EVENING...WHICH ALLOWED
TEMPERATURES TO DROP INTO THE UPPER TEENS IN MANY SPOTS. BECAUSE
OF THIS...NOW HAVE THE ADVISORY FOR JEFFERSON COUNTY AS WELL...AND
UNTIL 1000 AM. FROZEN QPFS WILL NOT BE MUCH. LOOKING FOR JUST A
LIGHT GLAZE OF ICE IF ANYTHING...BUT IT DOES NOT TAKE MUCH ICE TO
MAKE THINGS SLICK.

OTHERWISE...EXPECT AREAS OF FOG TO DEVELOP BEHIND THIS...WITH JHW
ALREADY DOWN TO A HALF MILE. FOG WILL SPREAD ACROSS ALL OF THE
SOUTHERN TIER...BUT THE SE DOWNSLOPE FLOW SHOULD LIMIT FOG NORTH
OF THE I-90 THRUWAY.

WARM AIR OVERSPREADS THE ENTIRE FORECAST AREA BY MID MORNING ON
WEDNESDAY AND THE STEADIER RAINS WILL FOLLOW CLOSELY. RAINFALL
TOTALS WILL RANGE FROM A THIRD TO A HALF INCH FROM LATE MORNING
THROUGH WEDNESDAY EVENING. THIS SAID...LOCALIZED AMOUNTS TO AN
INCH ARE POSSIBLE...ESPECIALLY SOUTH OF THE THRUWAY...WHERE BOTH
THE NAM AND HRRR BRING IN THE BEST QPFS. WOULD NOT BE SURPRISED TO
HEAR A RUMBLE OF THUNDER...GIVEN A MODEST AMOUNT OF ELEVATED CAPE.
WITH NO LIGHTNING STRIKES UPSTREAM...CARRY ONLY ISOLATED THUNDER
IN PORTIONS OF THE SOUTHERN TIER WEDNESDAY MORNING.

TEMPS WILL TOP OUT IN THE LOWER TO MID 40S ACROSS THE EASTERN LAKE
ONTARIO REGION WITH MID 40S TO LOW 50S FOR THE REMAINDER OF THE
FORECAST AREA.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
A SPLIT FLOW WILL REMAIN IN PLACE ACROSS THE COUNTRY DURING THIS
PERIOD WITH OUR FORECAST AREA GENERALLY BEING DOMINATED BY THE
SOUTHERN BRANCH. THIS WILL TRANSLATE INTO CONTINUED ABOVE NORMAL
TEMPERATURES WITH LITTLE (IF ANY) IN THE WAY OF SNOWFALL. SAME OL`
SAME OL`. WHILE THERE WILL BE ONE SIZE-ABLE SHORTWAVE OF NOTE DURING
THIS STRETCH...GUIDANCE HAS BEEN VERY CONSISTENT WITH KEEPING THE
BULK OF ITS AFFECTS TO OUR SOUTH. OUR REGION WILL BE MORE INFLUENCED
BY MORE SUBTLE FEATURES. THE DETAILS...

A POTENT SHORTWAVE WILL RACE ACROSS OUR FORECAST AREA WEDNESDAY
NIGHT. THIS WILL BE A `WARM` PCPN EVENT WITH WIDESPREAD RAIN IN THE
EVENING TAPERING OFF DURING THE COURSE OF THE OVERNIGHT. THE RAIN
EARLY ON WILL BE ENHANCED BY SOME DECENT JET INDUCED LIFT SO THAT
TOTAL RAINFALL FROM THE SYSTEM WILL AVERAGE A QUARTER...TO AT MOST
ONE HALF INCH. AS THE SHORTWAVE EXITS ACROSS NEW ENGLAND LATE
WEDNESDAY NIGHT...BROAD BASED RIDGING WILL BUILD IN FROM THE WEST.

ON THURSDAY...A LOW AMPLITUDE H5 RIDGE AND ASSOCIATED WEAK SFC HIGH
WILL MOVE ACROSS OUR FORECAST AREA. THIS WILL SUPPORT FAIR DRY
WEATHER WITH AFTERNOON TEMPERATURES RANGING FROM THE UPPER 30S
ACROSS PARTS OF THE NORTH COUNTRY TO THE MID AND UPPER 40S IN THE
GENESEE VALLEY AND SOUTH SHORE OF LAKE ONTARIO.

FAIR WEATHER SHOULD PERSIST ACROSS MOST OF THE REGION THURSDAY
NIGHT...ALTHOUGH A WEAK COLD FRONT SAGGING SOUTH FROM QUEBEC COULD
HELP TO PRODUCE SOME FLURRIES AND VERY LIGHT SNOW SHOWERS. A
CONFLUENT FLOW ALOFT SHOULD MINIMIZE ANY CHANCE FOR ACCUMULATING
SNOW.

FOR FRIDAY...THE AFOREMENTIONED WEAK COLD FRONT WILL PUSH ACROSS OUR
FORECAST AREA. WILL KEEP THE LOW CHC POPS IN PLAY FROM CONTINUITY...
BUT WILL ADD THE MENTION OF RAIN SHOWERS (ALONG WITH THE SNOW
SHOWERS) AS A VERY LIMITED SNOW GROWTH WILL BE IN PLACE. FORCING
FROM THE FRONT WILL BE VERY WEAK THOUGH...SO EVEN THE LOW CHC POPS
MAY BE TOO PESSIMISTIC.

WHILE THE NEXT POTENT SHORTWAVE WILL BE HEADING OUR WAY FROM THE
UPPER GREAT LAKES FRIDAY NIGHT...LINGERING SFC HIGH PRESSURE SHOULD
KEEP THE NIGHT MAINLY PCPN FREE.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
A SOMEWHAT AMPLIFIED +PNA PATTERN ACROSS THE LOWER 48 AT THE START
OF THIS PERIOD WILL QUICKLY BREAK DOWN INTO A LOW AMPLITUDE PACIFIC
FLOW AS MID LATITUDE BLOCKING WILL GENERALLY REMAIN ABSENT ACROSS
THE NORTHERN HEMISPHERE. MEDIUM RANGE GUIDANCE WAS SUGGESTING THAT
SOME BLOCKING COULD DEVELOP IN PREVIOUS MODEL RUNS...BUT THAT TREND
HAS SINCE BEEN REVERSED. THIS WILL RESULT IN TEMPERATURES AVERAGING
NEAR TO ABOVE NORMAL...ALTHOUGH THERE WILL BE BRIEF PERIODS WHEN IT
WILL BE SEASONABLY CHILLY.

THE BIGGEST QUESTION FOR MANY DURING THIS PERIOD IS...WILL THERE
ENOUGH SNOW FOR A WHITE CHRISTMAS? THAT MAY LARGELY DEPEND ON YOUR
SPECIFIC DEFINITION OF A WHITE CHRISTMAS...AS SIGNIFICANT SNOWFALL
FOR OUR REGION IS NOT CURRENTLY IN THE MAKING.

FOR SATURDAY...A POTENT SHORTWAVE IN THE NORTHERN BRANCH WILL BRUSH
BY TO OUR NORTH. THIS WILL BRING US THE CHANCE FOR SOME LIGHT SNOW
SHOWERS...BUT WITH A HIGHLY SHEAR AIRMASS IN ITS WAKE...ASSISTANCE
FROM THE LAKES (IE. LAKE EFFECT) IS NOT ANTICIPATED. THIS SHOULD
KEEP THE SNOW FROM MEASURING MORE THAN A COVERING.

THE MOST SIGNIFICANT WEATHER FEATURE OF THIS PERIOD WILL THEN TAKE
AIM ON THE MID ATLANTIC AND NORTHEAST COAST FOR CHRISTMAS DAY AND
NIGHT. THE MEDIUM RANGE GUIDANCE PACKAGES HAVE NOT BEEN IN SYNC WITH
THIS FEATURE FOR THE PAST SEVERAL RUNS...AND THAT FACT REMAINS THE
SAME AS THE GFS NEVER REALLY GENERATES ANYTHING AT THE SFC WHILE THE
USUALLY MORE TRUSTWORTHY ECMWF DEPICTS A COASTAL LOW. IT IS THIS
LATTER SOLUTION THAT SUGGESTS THE BACK-EDGE OF THE SYNOPTIC SNOW
SHIELD WILL LIFT UP ACROSS OUR AREA SUNDAY NIGHT. WILL RAISE POPS TO
40 TO COVER FOR THIS POTENTIAL. IF THE STORM SYSTEM WORKS OUT
EXACTLY AS DEPICTED...THEN THERE COULD BE SUB-ADVISORY CRITERIA SNOW
ACCUMS SOUTH AND EAST OF BUFFALO...BUT FROM THIS RANGE IT WOULD NOT
BE PRUDENT TO PUT A LOT OF CONFIDENCE INTO THAT.

A SEASONABLY COLD NORTHWEST FLOW IN ITS WAKE WILL COMBINE WITH A H5
TROUGH TO BRING US THE CHANCE FOR SNOW SHOWERS AND SOME LAKE
ENHANCEMENT MONDAY AND MONDAY NIGHT...THEN WARMING ALOFT AND THE
PROGRESSION OF A H5 RIDGE SHOULD ENCOURAGE FAIR AND MILDER WEATHER
FOR TUESDAY INTO MID WEEK.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
THE LEADING EDGE OF WARM AIR ADVECTION ALOFT IS GRADUALLY
CROSSING BUF AT 05Z. THIS MAY CAUSE A PERIOD OF LOWER CIGS...BUT
UPSTREAM OBS SUGGEST THIS WILL BE TEMPORARY. THE SE DOWNSLOPE
FLOW SHOULD KEEP BUF/IAG/ROC MAINLY MVFR TIL WEDNESDAY MORNING.

THE STEADY MODERATE TO POSSIBLY HEAVY RAIN WILL ENTER FROM SW TO
NE WEDNESDAY MORNING. THIS WILL LOWER CIGS...WITH A FAIR PERIOD OF
LIFR-IFR CONDITIONS EXPECTED. CONDITIONS WILL NOT IMPROVE UNTIL
THE LOW LIFTS ACROSS THE LAKES AND INCREASES WINDS AND
MIXING...WHICH WILL EVENTUALLY DRY THINGS OUT.

OUTLOOK...
WEDNESDAY NIGHT...MVFR/IFR WITH RAIN.
THURSDAY...MAINLY VFR.
THURSDAY NIGHT...CHC LIGHT SNOW OR RAIN
ESPECIALLY TOWARDS THE SOUTH AND EAST.
FRIDAY AND SATURDAY...MAINLY VFR CHC SNOW SHOWERS.
SUNDAY...MAINLY VFR IN SCTD SNOW SHOWERS.

&&

.MARINE...
HIGH PRESSURE ACROSS NEW YORK STATE TODAY WILL MOVE TO THE EAST OF
THE REGION TONIGHT. SOUTHERLY WINDS WILL INCREASE TONIGHT AND
WEDNESDAY AS A WARM FRONT LIFTS NORTH TOWARD THE LOWER LAKES...THE
ATTENDANT LOW AND COLD FRONT WILL CROSS THE LAKES ON WEDNESDAY NIGHT
WITH INCREASING WESTERLY WINDS AND WAVES BUILDING TO SMALL CRAFT
ADVISORY CRITERIA GENERALLY FROM WEDNESDAY EVENING THROUGH MID
MORNING ON THURSDAY.

&&

.CLIMATE...
THE WINTER OF 2011-12 HAS STARTED SLOW IN THE SNOWFALL CATEGORY
ACROSS WESTERN AND CENTRAL NEW YORK. THROUGH DECEMBER 19TH...THE
CURRENT SNOW THIS SEASON OF 3.0 INCHES (BUFFALO) AND 2.1
INCHES(ROCHESTER) ARE WELL BELOW NORMAL THUS FAR. THERE HAVE BEEN
SEVERAL YEARS THAT HAVE HAD SIMILAR STARTS THOUGH. BELOW IS A LIST
OF THE TOP LEAST AMOUNT OF SNOW IN BOTH CITIES...MEASURED AT THE
RESPECTIVE AIRPORTS...THROUGH AND INCLUDING CHRISTMAS EVE.

BUFFALO

1   3.0     2011
2   3.1     1998
3   3.3     1931
4   3.6     1896
5   4.3     1918
...
10  6.5     1888
15  7.8     1891

***NORMAL THROUGH DECEMBER 24TH 29.1***


ROCHESTER

1   2.1     2011
2   2.6     1939
3   3.7     2001
4   3.8     1877
5   4.2     2006
...
10  6.2     1998
15  7.8     1940

***NORMAL THROUGH DECEMBER 24TH 23.5***

SNOWFALL RECORDS GO BACK TO THE WINTER OF 1884-85.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY FROM 3 AM TO 10 AM EST WEDNESDAY FOR
     NYZ006>008.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM WEDNESDAY TO 8 AM EST THURSDAY
         FOR LEZ040-041.
         SMALL CRAFT ADVISORY FROM MIDNIGHT WEDNESDAY NIGHT TO
         8 AM EST THURSDAY FOR LOZ042-043.
         SMALL CRAFT ADVISORY FROM MIDNIGHT WEDNESDAY NIGHT TO 10
         AM EST THURSDAY FOR LOZ044-045.

&&

$$

SYNOPSIS...WCH
NEAR TERM...APFFEL/WCH
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...APFFEL
MARINE...APFFEL/WCH
CLIMATE...THOMAS








AREA FORECAST DISCUSSION

NWS WILMINGTON NC

 945 PM EST THU DEC 22 2011

.SYNOPSIS...
EXCEPTIONALLY MILD AIR AND WIDELY SCATTERED SHOWERS WILL PREVAIL
ACROSS THE REGION THROUGH EARLY FRIDAY AHEAD OF AN APPROACHING COLD
FRONT. COOLER AIR WILL SPILL INTO THE EASTERN CAROLINAS BY LATE
FRIDAY AS THE COLD FRONT MOVES OFFSHORE. SATURDAY WILL REMAIN DRY
BUT ONSHORE WINDS SUNDAY AND THE APPROACH OF A COLD FRONT WILL
BRING INCREASING CHANCES FOR RAIN TO THE REGION. THE COLD FRONT WILL
SWEEP ACROSS THE AREA WITH HIGH PRESSURE TO FOLLOW. FAIR CONDITIONS
WILL PREVAIL EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM THURSDAY...SFC LOW HAS ACCELERATED TO WEST
VIRGINIA...AND THE WESTERN PORTIONS OF VIRGINIA. BY DAYBREAK
FRIDAY...THIS LOW IS PROGGED TO REACH THE OFFSHORE WATERS OFF NJ.
THE COLD FRONT ASSOCIATED WITH THIS LOW...WILL REACH THE WESTERN
PORTIONS OF THE ILM CWA BY DAYBREAK FRI. CURRENT PCPN AHEAD OF THE
COLD FRONT HAS DRAMATICALLY WEAKENED/DISSIPATED FROM JUST 3 HOURS
EARLIER. THIS TREND TO CONTINUE AS OBSERVED WITH RADAR MOSAICS AND
LATEST HRRR PROGS. POPS HAVE BEEN LOWERED FOR THE OVERNITE...WITH
THE HIGHEST POPS ACROSS THE FA NOW ONLY AROUND 30 PERCENT. HIEST
POPS WILL RESIDE ALONG AND JUST AHEAD OF THE COLD FRONT BY DAYBREAK
FRI...WITH LATEST NAM AND HRRR MODELS INDICATING THIS ACTIVITY.
WIDESPREAD 60S FOR LOWS TONIGHT...EXCEPT POSSIBLY SOME 50S IF ENOUGH
COOL AIR BLEEDS INTO THE NW PORTIONS OF THE ILM CWA AFTER THE CFP
AROUND DAYBREAK FRI. THE NAM 8H TEMPS HAVE TRENDED LOWER IMMEDIATELY
AFTER CFP...WITH 1K-8H THICKNESSES ALSO FOLLOWING SUIT.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 PM THURSDAY...TEPID AIR MASS IN PREFRONTAL WARM SECTOR
WILL SWAMP THE EASTERN CAROLINAS INTO A PORTION OF FRIDAY. LOW
LEVEL DRYING WILL IMPINGE OUR FAR WESTERN DOORSTEPS BY MIDDAY
FRIDAY...TRANSITING OUR FAR SOUTHERN COASTLINES BY NIGHTFALL AS
A COLD FRONT MAKES ITS WAY STEADILY THROUGH.

BY FAR BULK OF RAINFALL WILL BECOME SHEARED ALONG THE APPALACHIAN
SPINE FRIDAY...AND RAINFALL PROSPECTS FOR OUR REGION WILL LIKELY
FALL INTO A 0.05-0.15 INCH RANGE ASSOCIATED WITH THIS SYSTEM AS
AS THE FAR NW PORTIONS OF A RIDGE HOLD OVER THE AREA.

COOLING LATE FRIDAY SHOULD ALLOW TEMPS TO DIP TO 42-50 DEGREE
RANGE DAYBREAK SATURDAY...COOLEST NORTHERN INTERIOR AND MILDEST
SOUTHERN COAST. FAIR AND DRY SATURDAY WITH NEAR NORMAL TEMPS IN
THE UPPER 50 TO LOWER 60S. RETURN FLOW AND OVER-RUNNING LATE
SATURDAY COULD BRING LIGHT RAIN INTO EARLY SUNDAY.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 300 PM THURSDAY...MEDIUM RANGE GUIDANCE CONTINUES TO STRUGGLE
WITH SOUTHERN STREAM SYSTEMS PROJECTED TO IMPACT THE REGION AT THE
START OF THE PERIOD AND AGAIN LATE IN THE PERIOD. SEEING SOME
AGREEMENT WITH RESPECT TO THE SYSTEM ON CHRISTMAS DAY...WHICH PASSES
JUST SOUTHEAST OF THE AREA. THE SHORTWAVE ASSOCIATED WITH THIS
FEATURE BECOMES STRETCHED OUT AND IS NOT VERY STRONG...NEITHER IS
ITS SURFACE INFLECTION. EXPECT PRECIP SHIELD FROM THIS SYSTEM WILL
AFFECT THE ENTIRE FORECAST AREA BUT RAIN IS GOING TO BE LIGHT WITH
LIMITED QPF.

SHORTWAVE TROF MOVING ACROSS THE MID ATLANTIC SUN NIGHT INTO MON
HELPS PUSH THE FRONT OFF THE COAST AND USHERS IN THE NEXT AIR MASS
WHICH KNOCKS TEMPS BACK TO CLIMO. HIGH PRESSURE OVER THE AREA MON
NIGHT THEN SHIFTS OFF THE COAST FOR TUE. ANOTHER SYSTEM EJECTING
FROM THE SOUTHWEST/GULF OF MEXICO NEXT WEEK MAY SPREAD PRECIP OVER
THE REGION WED AS IT PASSES TO THE SOUTHEAST...THOUGH CONFIDENCE
REMAINS LOW. HIGH PRESSURE RETURNS BUILDS BACK IN FOR THU.


&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 00Z...VFR OVER THE NEXT COUPLE OF HOURS WITH ANTICIPATED
STRATUS LAYER ALONG COAST OVERNIGHT...WITH RESTRICTION-CAUSING
VCSH/SHRA WITH APPROACHING COLD FRONT FRIDAY MORNING THROUGH EARLY
AFTERNOON.

THROUGH TONIGHT...WILL PERSIST WITH VFR SCT/BKN CIGS AT ALL
TERMINALS...WITH BRIEF WINDOWS OF SKC AT INLAND SITES...WITH
SOUTHWEST WINDS AOB 11 KTS. CANNOT RULE OUT SOME LINGERING GUSTS UP
TO 15 KTS ALONG COAST OVER THE NEXT HOUR OR SO. OVERNIGHT INTO EARLY
FRIDAY MORNING...PRIMARY CONCERN WILL BE THE POTENTIAL FOR LOW-LYING
STRATUS ALONG THE COAST...ANYWHERE FROM 300-800 FT...AS DEPICTED BY
BOTH TIME-HEIGHTS AND FCST SOUNDINGS. FOR NOW...HAVE LEFT STRATUS
LAYER AS SCT GIVEN UNCERTAINTY OF OPACITY. HOWEVER...COULD CHANGE
QUICKLY...BECOMING MVFR/IFR...AND COULD PERSIST THROUGH EARLY
MORNING.

BEFORE DAYBREAK...ANTICIPATE -SHRA TO AFFECT INLAND TERMINALS...AND
THEN COASTAL TERMINALS...WITH MVFR POSSIBLE IN HEAVIER SHOWERS.
WINDS WILL BE WEST-SOUTHWEST AOB 10 KTS. BY AFTERNOON...EXPECT RAIN
ACTIVITY TO DIMINISH WEST TO EAST IN ASSOCIATION WITH
FROPA...ALLOWING SKY COVER TO IMPROVE TO SCT...AND POSSIBLY SKC AT
INLAND TERMINALS...BEFORE END OF VALID PERIOD. WINDS WILL BECOME
NORTH-NORTHWEST AOB 10 KTS.

EXTENDED OUTLOOK...VFR SATURDAY. RAIN AND IFR POSSIBLE SUNDAY AND
MONDAY. VFR TUESDAY.

&&

.MARINE...

NEAR TERM /THROUGH TONIGHT/...
AS OF 930 PM THURSDAY...WIND SPEEDS OVER THE COASTAL WATERS CONTINUE
TO BE OVER FORECAST BY THE MODELS. IE. LATEST HRRR INDICATING AS
HIGH AS 25-30 KT SUSTAINED PRIOR TO DAYBREAK. AGAIN...LIKE A BROKEN
RECORD...SSTS IN THE 50S RESULTING IN A THICK COOL STABLE SFC BASED
LAYER HAS PREVENTED THE MIXING OF 30+ KT WINDS JUST OFF THE DECK TO
THE OCEAN SFC. THE INCREASED TIGHTENING OF THE SFC PG WILL RESULT
WITH SW WINDS AROUND 10 KT...INCREASING TO 15 TO POSSIBLY 20 KT
AFTER MIDNIGHT. SEAS AROUND 3 FT...TO BUILD TO 3 TO 5 FT. WITH THE 5
FOOTERS LIKELY CONFINED ACROSS THE OUTER WATERS OFF CAPE FEAR WHERE
SOME LEACHING TO OCCUR FROM THE HIGHER SEAS FROM OFFSHORE.
SIGNIFICANT SEAS WILL BE DOMINATED BY 4 TO 7 SECOND SHORT PERIOD
WAVES. OVERALL...SCEC CONDITIONS TO CONTINUE INTO DAYLIGHT FRIDAY.
THE 65+ HIGHER SFC DEWPOINTS HAVE BEEN DIFFICULT TO REACH AND/OR
ADVECT ACROSS THE COASTAL WATERS TONIGHT...AND AS A RESULT THE SEA
FOG POTENTIAL HAS DIMINISHED. WILL CONTINUE TO INDICATE PATCHY SEA
FOG TO AFFECT THE COASTAL WATERS. BUT WITH WINDS VEERING TO WSW BY
DAYBREAK FRIDAY...SOME LOWER DEWPOINTS FROM OFF THE MAINLAND WILL
FILTER ACROSS THE WATERS AND DIMINISH THE OVERALL SEA FOG
POTENTIAL.

SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 PM THURSDAY...CAUTIONARY HEADLINES WILL LIKELY EXTEND
INTO EARLY FRIDAY AS A COLD FRONT MOVES ACROSS THE APPALACHIAN
MOUNTAINS AND PINCHES THE PRESSURE GRADIENT...BUT BY AFTERNOON
WINDS WILL EASE AS THE FRONT EDGES NEAR. WINDS TO SHIFT TO N
ALONG THE NORTH COAST EARLY AFTERNOON...AND BY LATE AFTERNOON
OR EARLY EVENING ACROSS WINYAH BAY. 3-5 FOOT S WAVES WITH 6-7
SECOND INTERVALS EXPECTED FRIDAY. FRIDAY NIGHT AND SATURDAY THE
S WAVE ENERGY WILL FADE AND BECOME REPLACED BY CHOPPY ENE WAVES
AS WINDS OFFSHORE VEER TO NE AND E. NO TSTMS EXPECTED ON THE
0-20NM WATERS THIS PERIOD...BUT POSSIBLE OVER THE GULF STREAM.

LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 3 PM THURSDAY...NORTHERLY FLOW SUN AS WEAK LOW PRESSURE PASSES
SOUTHEAST OF THE WATERS BECOMES NORTHWESTERLY SUN NIGHT AND MON AS
HIGH PRESSURE BUILDS EAST. BRIEF PERIOD EARLY MON WHERE GRADIENT
PINCHES AS HIGH BUILDS IN AND LOW WELL EAST OF THE DELMARVA DEEPENS.
OFFSHORE FLOW MAY HIT 20 KT...BUT DURATION WILL BE A FEW HOURS AT
MOST. WINDS GRADUALLY VEER TO NORTHEAST MON INTO MON NIGHT WITH
SPEEDS FALLING TO 10 TO 15 KT BY MON EVENING. SURFACE RIDGE AXIS
MOVES OVERHEAD TUE MORNING...SHIFTING OFFSHORE IN THE AFTERNOON.
SOUTHERLY FLOW CONTINUES INTO TUE NIGHT WITH SPEEDS 10 KT OR LESS.
SEAS GENERALLY 2 TO 3 FT WITH THE EXCEPTION OF LATE SUN NIGHT AND
MON MORNING WHEN STRONG OFFSHORE FLOW WILL INCREASE SEAS WELL AWAY
FROM SHORE BY A FOOT OR SO.


&&

.ILM WATCHES/WARNINGS/ADVISORIES...

SC...NONE.
NC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...DCH
SHORT TERM...MJC
LONG TERM...III
AVIATION...SGL













AREA FORECAST DISCUSSION

NWS GREENVILLE-SPARTANBURG SC

 958 AM EST WED DEC 21 2011

.SYNOPSIS...
AN UNSETTLED WEATHER PATTERN WILL PERSIST THROUGH THE REMAINDER OF
THE WEEK AND INTO THE HOLIDAY WEEKEND. A COLD FRONT WILL PUSH TOWARD
THE WESTERN CAROLINAS WEDNESDAY AND BECOME STATIONARY. MEANWHILE...A
LOW PRESSURE SYSTEM WILL FORM ACROSS THE GULF OF MEXICO THURSDAY AND
MOVE ALONG THE STATIONARY FRONT INTO FRIDAY. YET ANOTHER AREA OF LOW
PRESSURE WILL LIKELY AFFECT THE REGION LATE SATURDAY THROUGH
CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AT 945 AM...THUNDER CHANCES HAVE BEEN INCREASED SLIGHTLY ALONG THE
SPINE OF THE SRN APPALACHIANS AS DEWPOINTS CONTINUE TO SURGE NWD
AHEAD OF THE FRONT. POPS HAVE ALSO BEEN INCREASED THROUGH MID AFTN
IN THE ERN PIEDMONT AS THE BEST COMBINATION OF LOW LEVEL WARM
ADVECTION AND UPPER JET DIVERGENCE IS PROVIDING GOOD FORCING IN THE
MOIST AIRMASS. TEMPS HAVE BEEN TRIMMED A DEGREE OR TWO
THROUGHOUT...ESPECIALLY IN SW SECTIONS.

OTHERWISE...THE MAIN LOW PRES SYSTEM TO THE NW CONTINUES TO LIFT NE
FROM IL TO THE GREAT LAKES TODAY. LOW LEVEL FLOW WILL VEER SLIGHTLY
TO DIMINISH THE WARM ADVECTION LIFT ACROSS OUR AREA...BUT SHOWERS
WILL BE SLOW TO DIMINISH FROM W TO E LATE TODAY AS THE BOUNDARY
SLOWLY SLIPS INTO THE FORECAST AREA.

TONIGHT...SHOWER ACTIVITY WILL CONTINUE TO DIMINISH...AS LOW LEVEL
FLOW VEERS IN RESPONSE TO CYCLONE LIFTING RAPIDLY INTO NEW
ENGLAND...AND MUCH DRIER AIR BEGINS TO PUSH IN ALOFT. WITH THE
FRONTAL BOUNDARY TAKING ON AN INCREASINGLY ZONAL ORIENTATION...IT
WILL SLOW DRAMATICALLY AND EVEN HANG UP OVER THE THE AREA TONIGHT.
THIS COULD RESULT IN A FEW SHOWERS PERSISTING INTO THE OVERNIGHT...
SO POPS NEVER ACTUALLY FALL BELOW SLIGHT CHANCE. OTHERWISE...WITH NO
APPRECIABLE CHANGE IN THE LOW LEVEL AIR MASS...MIN TEMPS WILL BE
WELL ABOVE NORMAL...IN FACT THEY WILL BE VERY CLOSE TO THE NORMAL
HIGH TEMPS FOR THIS TIME OF YEAR.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
AS OF 230 AM WEDNESDAY...THERE IS A CONSENSUS AMONG THE MODEL
GUIDANCE FOR KICKING OUT A SHORT WAVE OVER NORTHERN MEXICO AND TEXAS
ON THURSDAY. AT THE START OF THE PERIOD...CYCLOGENESIS WILL ALREADY
BE UNDERWAY ACROSS THE NW GULF ALONG THE STALLED FRONTAL BOUNDARY.
MOISTURE FLUX FROM THE GULF NEVER REALLY GOES AWAY INTO THURSDAY
MORNING ALTHO IT SEEMS THAT A LULL WILL PROBABLY DEVELOP BEFORE THIS
NEXT SYSTEM APPROACHES...AND HOPEFULLY A LULL CAN BE ENGINEERED INTO
THE FCST GRIDS BY LATER SHIFTS. AT ANY RATE...LOW LEVEL FORCING
COMES ROARING BACK ALONG THE OLD FRONT ON THURSDAY...SO EXPECT
PRECIP TO BREAK OUT QUICKLY FROM THE SW AS WE WORK THROUGH THE DAY.
GENERALLY FOLLOWED THE SREF WITH RAMPING THE POP ALL THE WAY UP TO
CATEGORICAL ACROSS THE MTNS AND FOOTHILLS BY THE END OF THE
DAY...WITH LIKELY ACROSS THE PIEDMONT. A PREFERENCE FOR THE ECMWF
WOULD BRING THE SURFACE LOW PAST THROUGH THE GREAT VALLEY OF TN
THURSDAY EVENING...SO EXPECT CONTINUED WARM ADVECTION/UPGLIDE ACROSS
MOST OF THE FCST AREA THROUGH THE EVENING. THE LOW SHOULD PULL AWAY
TO THE N OR NE EARLY FRIDAY MORNING...DRAGGING THE SURFACE FRONT
BEHIND IT AND ACROSS THE FCST AREA IN THE PRE-DAWN HOURS. THUS...AS
QUICKLY AS THE POP RAMPED UP...IT RAMPS BACK DOWN...FAVORING ONLY A
CHANCE OVER THE PIEDMONT BY SUNRISE FRIDAY. THAT PRECIP CHANCE
CONTINUES TO TAIL OFF TO SLIGHT CHANCE IN THE AFTERNOON E OF I-85 IN
CASE THE FRONT DOES NOT MAKE AS MUCH EASTWARD PROGRESS AS EXPECTED.
HIGH TEMPS HAVE BEEN NUDGED UPWARD A DEGREE OR TWO TOWARD THE
GUIDANCE BLEND.

CONFIDENCE PLUMMETS THEREAFTER. THE FRIDAY NIGHT AND SATURDAY PART
OF THE FCST HAS BEEN VEXING BECAUSE OF POOR CONTINUITY AND
CONSISTENCY IN THE MODEL GUIDANCE. FOR THIS CYCLE...THERE IS GOOD
AGREEMENT AMONG THE OPERATIONAL MODELS THAT THE FRONT WILL MAKE IT
OFFSHORE BY FRIDAY NIGHT AND WE WILL DRY OUT FROM THE NW AT LEAST
BRIEFLY. THE NEW 03Z SREF AGREES...GIVING US ESSENTIALLY A DRY FCST
FRIDAY NIGHT AND SATURDAY. THIS FLIES IN THE FACE OF THE PREVIOUS
FCST GUIDANCE...WHICH WAS HIGH CHANCE TO LIKELY FOR SATURDAY.
AGAIN...A LULL BETWEEN SYSTEMS MAKES SENSE. HOWEVER...WITH SUCH POOR
CONSISTENCY OF LATE...IF WE COMPLETELY ELIMINATE PRECIP CHANCES WE
MIGHT BE BACK IN THE POSITION OF HAVING TO ADD THEM ONCE AGAIN IN
THE NEXT CYCLE. SO...AFTER SOME BRIEF DRYING FRIDAY NIGHT...THE
COMPROMISE WILL BE TO LOWER THE POP TO THE SLIGHT CHANCE RANGE FOR
SATURDAY...WITH THE HOPE THAT CONFIDENCE WILL INCREASE AND ALLOW IT
TO BE ELIMINATED LATER TODAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
AS OF 320 AM WEDNESDAY...A COMPLICATED WX PATTERN REMAINS IN STORE
FOR THE EXT RANGE. THE LATEST OP MODELS ARE HAVING VARYING IDEAS ON
HOW TO HANDLE THE UPPER SPLIT FLOW...THE AMOUNT OF NRN STREAM
ENHANCING ENERGY MOVING SOUTH AND THE BREAKDOWN AND ALIGNMENT OF THE
SUBTROP HIGH. THERE ARE OTHER DIFFERENCES INCLUDING THE
CONFIGURATION OF THE H3 JET ENTRANCE/EXIT REGIONS...BUT SUFFICE TO
SAY ALL THIS DOESN/T TRANSLATE TO GOOD CONFIDENCE WRT TO THE LLVL
FEATURES NOR THE EXPECTED TIMING AND CHARACTER OF THE SENSIBLE WX.

THE PREVIOUS FCST WAS THUS GIVEN MUCH WEIGHT AND THE BIGGEST CHANGES
MADE WERE TO THE POP GRIDS SAT NIGHT INTO MON. STILL THINK THERE IS
A GOOD CHANCE OF A RELATIVELY WEAK WEDGE IN PLACE BEGINNING SAT
NIGHT AND STRONGER FLOW ASSOCIATED WITH THE MORE AMPLIFIED ECMWF
BRINGS IN A MOIST GOM AIR MASS EARLY...WHILE THE 00Z GFS IS ABOUT 12
HRS LATER WITH MEASURABLE PRECIP REACHING THE WRN ZONES BY 12Z SUN.
THERE IS SOME TOKEN SUPPORT FOR THE GFS SOLN BY THE SLOWEST 00Z CMC
AND THE LATEST STATISTICAL GUIDANCE HAS MADE SIGNIFICANT CHANGES IN
12 HR POPS...SO THE POP GRIDS WERE ADJUSTED DOWN EARLY...WHICH
MATCHES WELL WITH THE SHORT RANGE THINKING...THEN BROUGHT UP TO HIGH
END CHANCE BY SUN AFTERNOON.

PARTIAL THICKNESSES SUGGEST A MARGINAL P/TYPE ISSUE ACROSS THE NC
MTNS SAT NIGHT...BUT FOR NOW IT DOESN/T LOOK LIKE MOISTURE WILL BE
DEEP ENOUGH FOR MUCH IF ANY ACCUM SNOW BELOW 3.5 KFT AS SFC
TEMPS/TDS DONT SUPPORT IT. UP HIGHER...SNOW MAY REACH ADVISORY
LEVELS BY SUN NIGHT...BUT IT REALLY IS TOO EARLY TO TELL SINCE MODEL
THERMAL CONSENSUS IS HIGHLY LACKING.

EXPECT MAX TEMPS TO BE THE COLDEST SUN WITH CLOUDS AND N/LY OR
PERHAPS NE/LY WEDGE TYPE FLOW KEEPING HIGHS A COUPLE DEGREES BELOW
NORMAL. A SLOW AND WEAK WARM UP TO AROUND NORMAL IS PROBABLE MON AND
TUE AS THE SYSTEM MOVES EAST OF THE AREA AND INSOLATION INCREASES.
THE LATTER PART OF THE EXT RANGE REMAINS DRY AND WARMER...BUT THIS
COULD CHANGE TO MORE OF A WET AND COLD PATTERN SINCE THERE IS
EVIDENCE OF ANOTHER SRN STREAM OR A GOM SYSTEM IMPINGING ON THE AREA
WED AND THU.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...WIDESPREAD LIGHT TO MODERATE SHOWERS WILL CONTINUE THROUGH
AT LEAST MID AFTERNOON BETWEEN WARM ADVECTION AND UPPER JET
DIVERGENCE FORCING. VERY LITTLE RECOVERY THROUGH IFR IS THUS
EXPECTED FOR THE REMAINDER OF THE DAY SO WILL REMOVE THE IMPROVEMENT
TO MVFR PREVIOUSLY ADVERTISED FOR LATE THIS AFTN AND THIS EVENING.
THE RUC PROFILES HAVE BACKED OFF ON LOW LEVEL WIND SHEAR FOR THE
AFTN...WILL LIKELY ALLOW THE CURRENT MENTION TO EXPIRE AT 19Z AS S
TO SW SFC WINDS CONTINUE TO INCREASE. LIFR CONDITIONS WILL LIKELY
RETURN OVERNIGHT AS MID AND UPPER DRYING OCCURS BUT THE BL REMAINS
VERY MOIST.

ELSEWHERE...MOIST SRLY FLOW CONTINUES TO COMBINE WITH WARM ADVECTION
AT LOW LEVELS AND IMPROVING JET DIVERGENCE ALOFT TO KEEP LIGHT
PRECIP GOING AT ALL TAF LOCATIONS. THE BEST THUNDER CHANCES SHOULD
REMAIN WEST OF KAVL AND S OF KAND THROUGH THE AFTN. VERY LITTLE
IMPROVEMENT IS EXPECTED THROUGH IFR TODAY...AND A RETURN TO
LIFR/VLIFR IS NOW EXPECTED THROUGHOUT OVERNIGHT. S TO SW FLOW WILL
STEADILY INCREASE TOWARD 10KT THIS AFTN...BUT WILL NOT FEATURE ANY
GUSTS.

OUTLOOK...LOW CIGS/POOR VSBY WILL CONTINUE INTO EARLY THU...
WITH RAIN EXPECTED TO REDEVELOP OVER THE AREA BY AFTERNOON.
OTHERWISE...VERY UNSETTLED CONDITIONS WILL PERSIST INTO EARLY NEXT
WEEK...AS A FRONT STALLS IN THE VICINITY AND ADDITIONAL WAVES OF LOW
PRESSURE RIPPLE NE ALONG THE FRONTAL ZONE. RESTRICTIONS WILL BE
POSSIBLE JUST ABOUT ANYTIME THROUGH THE OUTLOOK PERIOD.

AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...

WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

$$
SYNOPSIS...SBK
NEAR TERM...HG/JDL
SHORT TERM...PM
LONG TERM...SBK
AVIATION...HG/JDL








AREA FORECAST DISCUSSION

NWS LINCOLN IL

 1131 PM CST THU DEC 22 2011

.DISCUSSION...
ISSUED 900 PM CST THU DEC 22 2011

BAND OF LIGHT SNOW/FLURRIES HAS PUSHED EAST OF THE I-55 CORRIDOR
INTO EAST CENTRAL ILLINOIS...AND WILL PUSH INTO INDIANA WITHIN
THE NEXT FEW HOURS. A CLEARING LINE IS SINKING TOWARD THE AREA
FROM THE UPPER MIDWEST/WESTERN GREAT LAKES...AND THIS CLEARING
SHOULD SPREAD FROM NORTHWEST TO SOUTHEAST OVERNIGHT INTO EARLY
FRIDAY. THIS CLEARING WILL QUICKLY BE FOLLOWED BY A RIDGE OF HIGH
PRESSURE...PROVIDING QUIET WEATHER LOCALLY FOR THE HOLIDAY
WEEKEND.

GOING FORECAST IS IN GOOD SHAPE OVERALL. ONLY PLAN ON FEW MINOR
TWEAKS FOR THE LATEST AND EXPECTED OVERNIGHT TRENDS.

BAK
&&

.AVIATION...
ISSUED 1131 PM CST THU DEC 22 2011

LIGHT SNOW/FLURRIES HAVE SHIFTED EAST OF THE CENTRAL ILLINOIS
TERMINALS THIS EVENING...AND CLEARING IS APPROACHING FROM THE
NORTHWEST MORE QUICKLY THAN PREVIOUSLY ANTICIPATED. WITH THIS
TREND IN MIND...HAVE SKIES SCATTERING OUT...YIELDING VFR
CONDITIONS...IN THE NEXT FEW HOURS. THESE VFR CONDITION SHOULD
LINGER FOR THE DURATION OF THE 06Z TAF VALID TIME AS A RIDGE OF
HIGH PRESSURE PUSHES THROUGH THE REGION AT THE SURFACE. AN UPPER
LEVEL DISTURBANCE DIVING THROUGH THE GREAT LAKES BY LATE FRIDAY
SHOULD RESULT IN INCREASING MID LEVEL CLOUDINESS...BUT NO
PRECIPITATION IS ANTICIPATED.

BAK
&&

.PREV DISCUSSION...
ISSUED 225 PM CST THU DEC 22 2011

19Z SFC MAP INDICATED WEAK FRONT WASHING OUT NEAR I-57 WITH LIGHT
NORTHERLY BEHIND IT. MAIN WEATHER SYSTEM ACROSS THE COUNTRY WAS
LOCATED WELL TO OUR SOUTHEAST...HOWEVER STRATIFORM RAIN SHIELD
REACHED AS FAR NORTH AS THE OHIO VALLEY...AND CLOUDS ASSOCIATED WITH
THIS FEATURE OVERSPREAD THE ENTIRE AREA. BEYOND THIS EVENING...LITTLE IN
THE WAY OF FORECAST CONCERNS WITH A DRY AND MILD PATTERN PERSISTING
THROUGH MUCH OF NEXT WEEK.

SHORT TERM...TONIGHT AND FRIDAY
A COUPLE ITEMS OF INTEREST THIS EVENING. FIRST...NORTHERN FRINGE OF
OH VALLEY RAINS LOOK TO STAY JUST SOUTHEAST OF THE LAWRENCEVILLE
AREA IN REGION OF BETTER LIFT AND MOISTURE...BUT MAY INSERT LOW CHC POPS
IN THE FAR SE BASED ON LATEST RADAR TRENDS. OTHER ITEM IS RIBBON
OF 850-700 MB FRONTOGENESIS SLIDING SE INTO NRN MO/SE IA
CURRENTLY. RADAR MOSAIC INDICATES LIGHT SNOW BAND DEVELOPING FROM
KMCI TO NEAR KIRK IN MO. LATEST RUN OF HRRR AND 12KM NAM STREAK
THIS BAND TO THE EAST...ACROSS PARTS OF CENTRAL ILLINOIS THIS
EVENING. AIRMASS IS FAIRLY DRY...SO BELIEVE MOST PRECIP GENERATION
WILL BE EATEN BY SATURATION PROCESSES. HOWEVER SOME SCATTERED
FLURRIES OR BRIEF PERIODS OF LIGHT SNOW LOOK POSSIBLE FOR ROUGHLY
THE NW HALF BEFORE FRONTOGENESIS WANES AFTER MIDNIGHT. AS THE MAIN
SYNOPTIC WEATHER FEATURES SHIFT FARTHER EAST TOMORROW...HIGH
PRESSURE WILL BEGIN TO NOSE EAST FROM THE CENTRAL PLAINS. THIS
WILL ALLOW SKIES TO CLEAR FROM WEST TO EAST FOR A WELCOME RETURN
TO SUNSHINE.

LONG TERM...SATURDAY THROUGH THURSDAY
AS HAS BEEN THE CASE MUCH OF THIS EARLY WINTER...SPLIT FLOW JET
STREAM PATTERN WILL DOMINATE THE EXTENDED PORTION OF THE FORECAST.
THIS WILL KEEP ANY ARCTIC AIR BOTTLED UP IN CANADA...AND ANY
MOISTURE-RICH SHORTWAVES WELL TO OUR SOUTH. THIS PATTERN IS
CONSISTENT WITH POSITIVE PHASES OF THE AO AND NAO...AND THESE ARE
FORECAST TO STAY POSITIVE FOR THE NEXT COUPLE WEEKS.

THE HOLIDAY WEEKEND WILL FEATURE EXCELLENT TRAVEL
CONDITIONS...WITH THE CLOSEST PRECIPITATION BEING LAKE EFFECT AND
CLIPPER SNOW FOR THE GREAT LAKES...AND RAIN FROM THE LOWER
MISSISSIPPI VALLEY INTO THE DEEP SOUTH. FOR THE LOCAL
AREA...MOSTLY CLEAR SKIES AND TEMPERATURES RUNNING 5-10 DEGREES
ABOVE NORMAL WILL DOMINATE...WITH ANY CLIPPERS STAYING WELL TO OUR
NORTHEAST. THERE IS SOME MODEL DISAGREEMENT MONDAY NIGHT...WHEN A
SOUTHERN STREAM SHORTWAVE LIFTS INTO THE MS VALLEY. PREVIOUS
GUIDANCE AND THE CURRENT GFS KEEP ANY RAIN WITH THIS FEATURE WELL
SOUTH OF THE AREA...WHILE THE LATEST ECMWF AND GEM BRING RAIN OR A
RAIN/SNOW MIX UP TO THE LOWER GREAT LAKES BY TUESDAY MORNING. FOR
NOW WILL BASE THE FORECAST ON THE MORE CONSISTENT/DRY SOLUTION BUT
KEEP AN EYE ON THIS PERIOD FOR POP ADJUSTMENT. BEYOND THIS
POTENTIAL SYSTEM...ZONAL UPPER LEVEL FLOW WILL PRODUCE DRY AND
SEASONABLY WARM WEATHER THROUGH MID-WEEK.

25


&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$











AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

 1141 PM CST THU DEC 22 2011

.AVIATION...
HIGH PRESSURE BUILDING INTO THE PLAINS IS BRINGING COLDER...DRIER
AIR INTO THE LOCAL AREA THIS EVENING. EXPECT CLEAR TO MOSTLY
CLEAR SKIES WITH VISIBILITIES AOA 7 MILES WITH NW TO NORTH WINDS
OF 5 TO 10 MPH BECOMING SOUTHWEST BY LATE MORNING FRIDAY.
.NICHOLS..

&&

.PREV DISCUSSION... /ISSUED 321 PM CST THU DEC 22 2011/


SYNOPSIS...
SURFACE ANALYSIS AT 18Z SHOWED THE COLD FRONT THAT MOVED THROUGH
OVERNIGHT STRETCHED FROM NE TX ACROSS FAR SOUTHERN IL TO LOWER MI.
A 1032 HIGH WAS BUILDING INTO SD AND NE WITH A RESULTING TIGHT
PRESSURE GRADIENT ACROSS IA PRODUCING 15 TO 20 KT NORTHERLY WINDS
OVER MUCH OF THE FORECAST AREA. SATELLITE IMAGES INDICATED THE
BACK EDGE OF THE SOUTHWARD RETREATING STRATUS DECK REACHING FROM
KOTM TO NEAR GALENA. A NARROWER...MORE CONVECTIVE LOOKING CLOUD
DECK WITH MVFR BASES WAS FURTHER NORTH ACROSS NE IA INTO
WI...SHOWING SINGS OF SHRINKING AS IT WAS ADVANCING SLOWLY
SOUTHWARD. FURTHER SOUTH...AREA RADARS SHOWED AN EXPANDING BAND OF
REFLECTIVITY FROM KIRKSVILLE TO THE QUAD CITIES...LIKELY
ASSOCIATED WITH A WEAK MID LEVEL VORT MOVING THROUGH THE AREA AND
THE DEPARTING 300 MB JET CORE. 12Z ANALYSIS REVEALED THIS JET MAX
EMBEDDED IN THE UPPER LEVEL SW FLOW AHEAD OF A NORTHERN STREAM
TROUGH FROM HUDSON BAY SE INTO NEB AND A SEPARATE...MORE
CUTOFF...MID AND UPPER LEVEL CIRCULATION OVER SOUTHERN UT.

SHORT TERM...TONIGHT AND FRIDAY...
INITIAL CONCERN IS THE POTENTIAL FOR VERY LIGHT SNOW OR FLURRIES
OVER THE NEXT SEVERAL HOURS...THEN FOCUS TURNS TO OVERNIGHT LOW
TEMPERATURES. THE EXPANDING AND INCREASING BAND OF LIGHT SNOW
MENTIONED IN THE SYNOPSIS OVER THE SOUTH HAS RECENTLY BEGUN SHOWING
UP WITH GENERALLY 1 TO 4SM -SN ALONG THE MS RIVER SOUTH OF
MUSCATINE. BASED ON VSBYS AND RADAR TRENDS...COULD SEE A QUICK
DUSTING TO POSSIBLE 1/2 INCH BEFORE THE MID LEVEL FORCING...WHICH
THE LATEST RUC AND NAM12 HAVE A ROUGH HANDLE ON...QUICKLY PUSHES
EAST BEFORE 00Z. HAVE THUS INCREASED A SMALL AREA TO LIKELY POPS FOR
LATE AFTERNOON FOR ALONG AND EAST OF THE MS RIVER SOUTH OF THE QUAD CITIES
INTO IL.

OVERNIGHT...HIGH PRESSURE RIDGE EXTENDING W-NW FROM THE HIGH PLAINS
HIGH...ALONG WITH MID LEVEL SUBSIDENCE BEHIND THE SHORTWAVE PASSING
TO THE NORTH SHOULD PUSH THE LOW CLOUDS SOUTH OF THE AREA BY
MIDNIGHT. CLEARING SKIES AND LIGHT WINDS SHOULD RESULT IN THE
COLDEST NIGHT IN SEVERAL DAYS...AND BASED ON TRAJECTORIES...LOWS
CLOSE TO GUIDANCE BLEND FROM AROUND 15 NORTH TO LOWER 20S SOUTH LOOK
REASONABLE. FRIDAY...SUNSHINE...LACK OF SNOW COVER...AND RETURN FLOW
SOUTHWEST WINDS WILL ALLOW TEMPERATURES TO RECOVER WELL INTO THE
30S. ..SHEETS..

LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY...
THE EXTENDED FORECAST REMAINS DOMINATED BY MOSTLY BENIGN NORTHWEST
FLOW FRONTAL PASSAGES. THIS NORMALLY REPRESENTS A BELOW NORMAL
FORECAST FOR TEMPERATURES...BUT WITH SPLIT FLOW...THIS SHOULD KEEP
TEMPERATURES GENERALLY ABOVE NORMAL...AND ALSO WILL KEEP POPS VERY
LOW. THERE REMAINS TWO POTENTIAL POP CHANCES IN THE EXTENDED...BUT
BOTH ARE POORLY SHOWN WITH RESPECT TO CONSISTENCY IN ANY ONE MODEL
RUN.  THE FIRST...MONDAY AND MONDAY NIGHT... THE MODEL BLEND KEEPS
THE FORECAST DRY AS THE GFS CONTINUES TO SHOW A CLIPPER PASSING WELL
NORTH OF THE CWA....RESULTING IN DRY WAA DAY. HOWEVER...THE ECMWF
AND CANADIAN BOTH BRING THE CUT OFF LOW FROM THE SOUTHWEST UP OVER
THE CWA MONDAY AND MONDAY NIGHT...RESULTING IN POTENTIAL RAIN OR
SNOW. FOR NOW...HAVE BUMPED UP POPS TO 10 TO 14 PERCENT AND SKY
COVER AS WELL...BUT LEFT DRY.

AFTER SEVERAL MORE DAYS OF BENIGN NORTHWEST FLOW...MODELS SHOW
ANOTHER BROAD TROF MOVING PAST THE REGION AROUND FRIDAY. THIS WAVE
INITIALIZED WITH SLIGHT TO LOW CHANCE POPS FOR SNOW.

TEMPERATURES THROUGHOUT THE FORECAST ARE GENERALLY FROM THE MID 30S
TO MID 40S...WITH LOWS IN THE MID 20S TO LOWER 30S. SUCH
TEMPERATURES ARE VERY MILD FOR THE SHORTEST DAYS OF THE YEAR.
ERVIN..

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

WDN






AREA FORECAST DISCUSSION

NWS GRAY ME

 1149 PM EST THU DEC 22 2011

.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTHEAST FROM THE MID ATLANTIC STATES
OVERNIGHT, THEN PASS JUST SOUTH AND EAST OF THE GULF OF MAINE ON
FRIDAY. HIGH PRESSURE AND DRY AIR FOLLOWS FOR LATER SATURDAY INTO
CHRISTMAS DAY. A WEAK WARM FRONT COULD PRODUCE A FEW SNOW SHOWERS
ACROSS NORTHERN SECTIONS OF THE AREA LATE CHRISTMAS DAY. A COLD
FRONT WILL CROSS THE AREA EARLY MONDAY, WHILE AN OCEAN LOW PASSES
WELL SOUTH AND EAST OF THE AREA. HIGH PRESSURE WILL BUILD BY TO
OUR SOUTH LATE MONDAY INTO TUESDAY.

&&

.NEAR TERM /UNTIL 8 AM FRIDAY MORNING/...

1150 PM...I MADE MINOR ADJUSTMENTS TO 1ST PERIOD GRIDS. SOME
ADJUSTMENTS TO COASTAL FOR WIND DIRECTIONS WITH BOUNDARY DRAPED
ACROSS THE WATERS. MAY NEED A MARGINAL SCA OUTSIDE THE BAYS FOR
LATER TODAY INTO TONIGHT.

PREV DISC...

***HAVE ISSUED WINTER WEATHER ADVISORIES FOR MUCH OF SOUTHERN NH
 (EXCEPT ROCKINGHAM COUNTY) AS WELL AS INTERIOR YORK COUNTY MAINE***

LOW LEVEL TEMPERATURES: FOR A COUPLE HOURS THIS
EVENING...TEMPERATURES TOOK A NOSEDIVE NORTH OF A LINE FROM ABOUT
LACONIA NH...EASTWARD TO SANFORD MAINE. JUST AFTER SUNSET...AN
AREA OF LOW CLOUDS DEVELOPED SOUTH OF THIS LINE...INHIBITING
FALLING TEMPERATURES WHILE CLEAR SKIES REMAINED TO THE NORTH.
SINCE THEN...THE LOW CLOUDS HAVE DISSIPATED...WITH JUST HIGH
CLOUDS STREAMING ACROSS CENTRAL AND NORTHERN AREAS. AT THIS
TIME...HAVE ADJUSTED TEMPERATURES DOWNWARDS BASED ON THE
DIFFERENCES LAST HOUR BETWEEN THE FORECAST DATABASE AND
OBSERVATIONS AS OF 01Z. DESPITE REMAINING IN THE UPPER 30S HERE AT
GYX (2M TEMPERATURE)...THE SIDEWALKS AND GRASSY SURFACES IN THE
AREA ARE BEGINNING TO FREEZE UP ALREADY.

00Z SOUNDING: EVENING SOUNDING AT GYX CONTINUES TO CONTAIN PLENTY
OF DRY AIR AVAILABLE FOR EVAPORATIONAL COOLING. LOW LEVEL
TEMPERATURES WERE VERY CLOSE TO PROGS...PERHAPS EVER SO SLIGHTLY COOLER.

QPF: IN ADDITION TO THE COOL BIAS OVERNIGHT OVER THE NORTHERN 2/3
OF THE FORECAST AREA...SHORT TERM MODELS ARE STEADILY COMING IN
WITH SLIGHTLY MORE QPF FROM RUN TO RUN. THE HRRR MODEL NOW SHOWS
STORM TOTAL QPF OVER .50 INCHES OVER ALL OF SOUTHERN NH AND IN
YORK COUNTY ME...WITH THE NEXT CLOSEST MODEL IN TERMS OF QPF BEING
THE WETTER EURO. 18Z GFS AND NAM HAVE NUDGED UPWARDS AS WELL...AND
WE ARE AWAITING THE NAM. 21Z SREF NOW SHOWS UP TO 70% LIKELIHOOD
OF 4"OR MORE OVER ALL OF SRN NH...EXTENDING INTO FAR WESTERN
MAINE.

SNOWFALL: BASED ON MUCH OF THE INFORMATION DISCUSSED ABOVE...WILL
BE ADJUSTING SNOWFALL ACCUMULATIONS SLIGHTLY UPWARDS FOR SOUTHERN
AND CENTRAL AREAS DURING THE NEXT HOUR - INTO THE 3 TO 6 INCH
RANGE. THE HIGHER TOTALS WILL BE IN THE HILLTOWNS. ALONG THE COAST...FROM
COASTAL YORK COUNTY AND PORTIONS SOUTH...THERE WILL STILL BE
BOUNDARY LAYER PROBLEMS WITH RAIN MIXING IN WITH TIMES. THIS WILL
KEEP ACCUMULATIONS DOWN...ESPECIALLY ALONG COASTAL ROCKINGHAM
COUNTY WHERE LITTLE SNOWFALL WILL OCCUR.

MINOR ADJUSTMENT MADE TO OTHER PRODUCTS INCLUDING SLOWING THE
TIMING OF THE HIGH POPS...BUT ALL IN ALL...GRIDS APPEAR TO BE IN
GOOD SHAPE. WILL LIKELY BE ISSUING A STATEMENT LATER THIS EVENING
TO ACCOUNT FOR THE TIMING AND PTYPE TRENDS...SINCE MUCH OF THIS
WILL AFFECT THE MORNING RUSH HOUR.

TIMING OF STEADY PCPN: LATEST HRRR RUN BRINGS THE INITIAL
PRECIPITATION INTO SOUTHERN NEW HAMPSHIRE AROUND 05Z OR 06Z WITH
THE HEAVIEST/STEADIEST PRECIPITATION ENTERING SOUTHERN NEW
HAMPSHIRE AROUND 09Z WHICH SEAMS REASONABLE AT THIS TIME.

PREV DISC...
A WEAK AND FAST MOVING SFC LOW MOVES NE FROM THE MID ATLANTIC
STATES TNGT THEN TRACKS TO THE NE JUST BEYOND THE GULF OF MAINE
FRIDAY...REACHING E OF THE HAGUE LINE LATE IN THE DAY. THE TRACK
IS ABOUT OVER THE BENCHMARK OF 40N 70W BUT DUE TO ITS RAPID
MOVEMENT AMOUNTS SHOULD REMAIN LIGHT. ALSO THE UPR LVL SUPPORT IS
LIMITED WITH A POSITIVE TILTED TROF AND A WEAK SFC LOW AS A
RESULT. STILL...THE MODELS FCST GENERALLY 2-4 INCHES OF SNOW WITH
THE HIGHEST AMOUNTS OVER SOUTHERN AREAS OF INTERIOR MAINE AND NH.
A FEW HIGHER AMOUNTS OF AROUND 5 INCHES CAN`T BE RULED OUT OVER
SOME AREAS OF HIGHER TERRAIN OVER SOUTHERN INTERIOR PORTIONS. THE
MOUNTAINS WILL SEE THE LEAST AMOUNT OF SNOWFALL WITH THIS SYSTEM
WITH ONLY AN INCH OR TWO EXPECTED.

THE TIMING OF THE PCPN IS FOR IT TO BEGIN OVER SOUTHWEST AREAS
AROUND OR SHORTLY AFTER MIDNIGHT BUT THEN RAPIDLY DEVELOP AND
OVERSPREAD THE REST OF THE REGION BY 10Z.

THE PRCP COULD START AS -RA OR MIXED -RASN OVER MORE SERN AND
COASTAL AREAS TNGT AS BOUNDARY LAYER UP TO 925 MB WILL HAVE TEMPS
AROUND OR JUST ABOVE FREEZING. EVENTUALLY PRCP CHANGES TO SN AS
TEMPS COOL DOWN. ON FRIDAY THE SN MAY MIX BACK TO RA IN THE MRNG OVER
THESE AREAS AS SFC AND BOUNDARY LAYER TEMPS AGAIN BEGIN TO CLIMB
INTO THE MID 30S.

&&

.SHORT TERM /8 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
CANADIAN HIGH PRES BUILDS SLOWLY SOUTH SO SOME CLEARING AND DRY CONDITIONS
EXPECTED WITH A RETURN TO MUCH COLDER TEMPS. USED A 50/50 BLEND
OF THE MAV/MET TEMPS.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
QUIET WEATHER FOR THE MOST THROUGH THE PERIOD. PERHAPS A FEW SNOW
SHOWERS XMAS AFTERNOON AND EVENING WITH SHORT WAVE TROUGH. THIS
MAY START AS SOME LIGHT OCEAN ENHANCED SNOW ON THE MID COAST
DURING THE AFTERNOON ON XMAS. OTHERWISE...WE/LL HAVE TO WAIT UNTIL
THE 28TH OR SO FOR THE POSSIBILITY OF ANYTHING DECENT IN THE
PRECIPITATION DEPT...AND EVEN THEN THE MODELS HAVE BEEN
INCONSISTENT.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...VFR CONDS THIS EVENING WILL BECOME MVFR TO IFR AFTER
MIDNIGHT FROM SOUTH TO NORTH AS SNOW DEVELOPS AND SPREADS NORTH.
OVER SOUTHEAST NEW HAMPSHIRE THE PCPN MAY FALL AS A MIX AT TIMES.
CONDITIONS WILL GRADUALLY IMPROVE TO VFR FRIDAY AFTERNOON ALTHOUGH
SOME SCATTERED SNOW SHOWERS MAY BRIEFLY REDUCE CIGS/VSBYS TO MVFR.
VFR CONDS ACROSS ALL AREAS FRIDAY NIGHT.

LONG TERM...MAINLY VFR THROUGH TUESDAY. A PERIOD OF MVFR POSSIBLE
XMAS DAY AND NIGHT IN SNOW SHOWERS.

&&

.MARINE...
SHORT TERM...WINDS AND SEAS WILL REMAIN BELOW SCA LEVELS
TNGT AND FRIDAY AS A WEAK AND FAST MOVING COASTAL LOW PASSES SOUTH
OF NEW ENGLAND. CANADIAN HIGH PRESSURE TO OUR NORTH SLOWLY BUILDS
SOUTH ACROSS THE WATERS FRIDAY NIGHT.

LONG TERM...SCA CONDS POSSIBLE OVER THE WEEKEND.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 1 PM EST FRIDAY FOR MEZ018.
NH...WINTER WEATHER ADVISORY UNTIL 1 PM EST FRIDAY FOR NHZ005>010.
MARINE...NONE.

&&

$$
ES







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 427 AM EST FRI DEC 23 2011

.SYNOPSIS...
NORTHEAST EXITING LOW PRESSURE WILL LEAVE LITTLE MORE THAN DRIZZLE
AND FLURRIES THIS MORNING. WEAK HIGH PRESSURE WILL PROVIDE DRY
SEASONABLE CONDITIONS FOR CHRISTMAS EVE AND MORNING. A CANADIAN
COLD FRONT MAY BRING RAIN AND SNOW SHOWERS CHRISTMAS NIGHT INTO
MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BLEND OF RECENT SURFACE AND RADAR DATA ALONG WITH HRRR AND NAM
MODEL OUTPUT SHOW LITTLE MORE THAN DRIZZLE OR FLURRIES LEFT ACROSS
THE UPPER OHIO VALLEY IN THE WAKE OF THE NORTHEAST EXITING LOW
PRESSURE SYSTEM. NAM MODEL PROFILES SHOW DRYING ALOFT WILL
CONTINUE, SO DO NOT EXPECT ANY LAKE-INDUCED INSTABILITY SHOWER
DEVELOPMENT.

LOW LEVEL DRYING WILL BE SLOWER, SO POST SYSTEM CLOUDS WILL LINGER
INTO THE AFTERNOON AND RESTRICT DAYTIME TEMPERATURE RISES TO NO
MORE THAN A COUPLE DEGREES OVER CURRENT READINGS, AN IDEA
SUPPORTED BY RECENT GFS AND NAM MOS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
WEAK MIDWEST HIGH PRESSURE WILL PROVIDE SLOW CLEARING TONIGHT
ACROSS THE UPPER OHIO VALLEY, BUT DO EXPECT A DECENT AMOUNT OF SUNSHINE
FOR SATURDAY CHRISTMAS EVE.

RECENT SREF MODEL OUTPUT SHOWS A CLIPPER-TYPE LOW PRESSURE SYSTEM
MOVING SOUTHEASTWARD THROUGH THE GREAT LAKES CHRISTMAS AFTERNOON
AND NIGHT, WHICH CAN PRODUCE COLD FRONTAL SHOWERS ACROSS THE UPPER
OHIO VALLEY. REGARDING PRECIPITATION TYPE, THE SURFACE LAYER
SHOULD BE WARM ENOUGH FOR IT TO BE RAIN SOUTH, BUT IT COULD BE
EITHER RAIN OR SNOW NORTH, AS GFS AND NAM MOS SUGGEST TEMPERATURES
TO BE NEAR SEASONABLE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
RECENT SREF MODEL OUTPUT SHOWS POST SYSTEM SNOW SHOWERS SHOULD BE
EXITING PAST THE MOUNTAINS MONDAY MORNING. ENSUING MIDWEST HIGH
PRESSURE SHOULD PROVIDE A DRY PERIOD MONDAY AFTERNOON AND NIGHT.

UNCERTAINTY INCREASES STARTING TUESDAY, AS THE UPPER JETSTREAM
FLOW EVOLVES INTO A WAVY ZONAL PATTERN ACROSS U.S.

ECMWF, CMC, AND A COUPLE MEMBERS OF THE GEFS MODEL OUTPUT SHOW AN
OCCLUDED FRONTAL SYSTEM MAY PASS EASTWARD THROUGH THE UPPER OHIO
VALLEY TUESDAY. ITS LIKEWISE POSSIBLE A SIMILAR TYPE SYSTEM MAY
PASS THROUGH THURSDAY OR FRIDAY.

WITH THE RESULTING LACK OF COLD AIR INTRUSION, EXPECT TEMPERATURES
THIS PERIOD TO AVERAGE 5 TO 8 DEGREES WARMER THAN NORMAL.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
PER BLEND OF RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR,
NAM, AND GFS LAMP MODEL OUTPUT, EXPECT IFR STRATUS TO REMAIN
ACROSS THE UPPER OHIO VALLEY INTO MORNING WITH PRECIPITATION REDUCED
TO LITTLE MORE THAN DRIZZLE OF FLURRIES IN SPOTS.

BY MIDDAY, EXPECT MOST STRATUS CEILINGS WILL HAVE LIFTED TO MVFR
LEVELS, AND STRATUS COULD BECOME SCATTERED BY EVENING.

OUTLOOK...SATURDAY THROUGH TUESDAY...
EXPECT MAINLY VFR SATURDAY INTO MIDDAY SUNDAY. THEN COLD FRONTAL
SHOWERS MAY CAUSE RESTRICTIONS CHRISTMAS SUNDAY AFTERNOON INTO
MIDDAY MONDAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 158 AM EST FRI DEC 23 2011

.SYNOPSIS...
NORTHEAST EXITING LOW PRESSURE WILL LEAVE LITTLE MORE THAN DRIZZLE
AND FLURRIES THIS MORNING. WEAK HIGH PRESSURE WILL PROVIDE DRY
SEASONABLE CONDITIONS FOR CHRISTMAS EVE AND MORNING. A CANADIAN
COLD FRONT MAY BRING RAIN AND SNOW SHOWERS CHRISTMAS NIGHT INTO
MONDAY.

&&

.NEAR TERM /THROUGH TODAY/...
BLEND OF RECENT SURFACE AND RADAR DATA ALONG WITH HRRR AND NAM
MODEL OUTPUT SHOW THE LIGHT RAIN ASSOCIATED WITH NORTHEAST
EXITING LOW PRESSURE TO DECREASE TO LITTLE MORE THAN DRIZZLE OR
FLURRIES BY DAYBREAK ACROSS THE UPPER OHIO VALLEY.

REGARDING ANY CHANGEOVER TO SNOW SHOWERS, NAM MODEL PROFILES SHOW
POST SYSTEM DRYING ALOFT THAT MAY PRECLUDE CLOUD TEMPERATURES TO
GET COLD ENOUGH FOR A COMPLETE CHANGEOVER TO SNOW SHOWERS THIS
MORNING. LIKEWISE SURFACE TEMPERATURES MAY NOT GET TO FREEZING TO
ALLOW ACCUMULATION.

POST SYSTEM CLOUDS WILL RESTRICT TEMPERATURE RISES TODAY, SO HIGHS
TODAY NOT BE ANY WARMER THAN CURRENT READINGS.


&&

.SHORT TERM /TONIGHT THROUGH SUNDAY/...
WEAK MIDWEST HIGH PRESSURE WILL PROVIDE SLOW CLEARING TONIGHT
ACROSS THE UPPER OHIO VALLEY, BUT DO EXPECT A DECENT AMOUNT OF SUNSHINE
FOR SATURDAY CHRISTMAS EVE.

RECENT SREF MODEL OUTPUT SHOWS A CLIPPER-TYPE LOW PRESSURE SYSTEM
MOVING SOUTHEASTWARD THROUGH THE GREAT LAKES CHRISTMAS AFTERNOON
AND NIGHT, WHICH CAN PRODUCE COLD FRONTAL SHOWERS ACROSS THE UPPER
OHIO VALLEY. REGARDING PRECIPITATION TYPE, THE SURFACE LAYER
SHOULD BE WARM ENOUGH FOR IT TO BE RAIN SOUTH, BUT IT COULD BE
EITHER RAIN OR SNOW NORTH, AS GFS AND NAM MOS SUGGEST TEMPERATURES
TO BE NEAR SEASONABLE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
RECENT SREF MODEL OUTPUT SHOWS POST SYSTEM SNOW SHOWERS SHOULD BE
EXITING PAST THE MOUNTAINS MONDAY MORNING. ENSUING MIDWEST HIGH
PRESSURE SHOULD PROVIDE A DRY PERIOD MONDAY AFTERNOON AND NIGHT.

UNCERTAINTY INCREASES STARTING TUESDAY, AS THE UPPER JETSTREAM
FLOW EVOLVES INTO A WAVY ZONAL PATTERN ACROSS U.S.

ECMWF, CMC, AND A COUPLE MEMBERS OF THE GEFS MODEL OUTPUT SHOW AN
OCCLUDED FRONTAL SYSTEM MAY PASS EASTWARD THROUGH THE UPPER OHIO
VALLEY TUESDAY. ITS LIKEWISE POSSIBLE A SIMILAR TYPE SYSTEM MAY
PASS THROUGH THURSDAY OR FRIDAY.

WITH THE RESULTING LACK OF COLD AIR INTRUSION, EXPECT TEMPERATURES
THIS PERIOD TO AVERAGE 5 TO 8 DEGREES WARMER THAN NORMAL.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
PER BLEND OF RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR,
NAM, AND GFS LAMP MODEL OUTPUT, EXPECT IFR STRATUS TO REMAIN
ACROSS THE UPPER OHIO VALLEY INTO MORNING. DO EXPECT PRECIPITATION
TO BE LITTLE MORE THAN DRIZZLE OF FLURRIES IN SPOTS BY THEN.
BY MIDDAY, EXPECT MOST STRATUS CEILINGS WILL HAVE LIFTED TO MVFR
LEVELS, AND STRATUS COULD BECOME SCATTERED BY EVENING.

OUTLOOK...SATURDAY THROUGH TUESDAY...
EXPECT MAINLY VFR SATURDAY INTO MIDDAY SUNDAY. THEN COLD FRONTAL
SHOWERS MAY CAUSE RESTRICTIONS CHRISTMAS SUNDAY AFTERNOON INTO
MIDDAY MONDAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 1250 AM EST FRI DEC 23 2011

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL MOVE INTO THE MID ATLANTIC
REGION OVERNIGHT THEN OFF THE NEW JERSEY COAST BY MORNING. THIS
SYSTEM WILL SPREAD RAIN OVER THE REGION THIS EVENING WHICH WILL
GRADUALLY CHANGE TO WET SNOW OVERNIGHT. MINOR SNOW ACCUMULATIONS
ARE LIKELY ACROSS CENTRAL NEW YORK, ESPECIALLY IN THE HIGHER
TERRAIN. THE REST OF THE HOLIDAY WEEKEND WILL BE COOLER WITH
TEMPERATURES CLOSER TO NORMAL ALONG WITH DRY CONDITIONS.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MIDNIGHT UPDATE...WE HAVE MADE SOME TWEEKS TO THE NEAR TERM. SFC
TEMPS WERE RUNNING A BIT ON THE COOL SIDE AND HAVE RAISED THEM A
FEW DEG OVER THE NXT 3-6 HRS. AS FOR PCPN...WE ARE LEANING TWDS
THE RUC AND OUR LCL WRF WHICH INDICATES A SLIGHTLY LATER CHGOVR
AND THEREFORE LESSER SNOW ACCUMS. DOUBT WE`LL SEE MUCH SNOW S OF
THE NY/PA BORDER...WITH BEST CHC N OF THE NY/PA BORDER ACRS THE
HIER ELEVATIONS OF THE CNTRL SRN TIER/SUSQ RGN WHERE AN INCH IS
PSBL...AND MAYBE 2 0R 3 INCHES OVER ERN DELAWARE COUNTY. PREV BLO...

10 PM UPDATE... PCPN HAS NOW ENVELOPED ALL BUT OUR FAR SERN
ZNS...AND IT SHOULD DEVELOP THERE AS WELL BY ARND 05Z. SAT IMAGERY
SHOWS A WELL DEVELOPED UPR-LVL WV APPROACHING FROM THE SW (AS
EVIDENCED BY NICE BAROCLINIC LEAF SIG)...WITH IMPROVING UPR-LVL
JET DYNAMICS. BEST/STEADIEST PCPN WILL OCCUR BETWEEN NOW AND ABT
10-12Z...WITH A FAIRLY RAPID DEPARTURE FROM SW TO NE THEREAFTER.

SFC TEMPS ARE WELL ABV FRZG ATTM ALL THE WAY BACK TO SRN
ONT...LENDING CREDENCE TO OUR FCST OF ONLY A GRADUAL CHG OVER TO
SNOW DURG THE NGT. WE`LL RIDE WITH OUR CURRENT FCST OF GENERALLY
1-3" OF SNOW (MOSTLY HIGHER ELEVS) ACRS MUCH OF CNY AND PA`S NRN
BORDER CNTYS...WITH LITTLE OR NOTHING DOWN TWDS THE WYO/LACK VLYS.

745 PM UPDATE... STEADIER PCPN IS SLOWLY OVERSPREADING THE AREA
FROM SW TO NE ATTM. THE INITIAL STRIPE OF PCPN SHOULD IMPACT OUR
NRN ZNS (FINGER LAKES RGN)...AS BETTER FGEN FORCING WILL RESIDE
HERE PRIOR TO 06Z. THEREAFTER...PCPN SHOULD RAPIDLY DEVELOP ACRS THE
ENTIRE FA...AS MOIST ADVECTION/UPPER JET DYNAMICS MAXIMIZE IN THE
06-12Z TIME FRAME.

IT CERTAINLY APPEARS THAT BLYR TEMPS WILL DICTATE PTYPE
OVERNIGHT...AS NO WARM LYR SEEMS EVIDENT ON MODEL SNDGS. GIVEN
MILD SFC TEMPS OUT THERE EARLY THIS EVE...IT SHOULD TAKE QUITE A
WHILE FOR SNOW TO MIX IN...SPCLY IN THE VLYS. WE`RE STILL GOING
FOR A CHANGE OVER TO SNOW FROM NW TO SE AFTER 06Z...MAINLY ON THE
HILLTOPS...REACHING THE TWIN TIERS IN THE 09-12Z TIME PD. THE
WYO/LACK VLYS LOOK TO STAY PRIMARILY RAIN FOR THE ENTIRE EVENT.

PREV DISC... A FAIRLY STRONG FAST MOVING WAVE WILL LIFT NORTHEAST
INTO THE MID ATLANTIC REGION BY MIDNIGHT THEN OFF THE NEW JERSEY
COAST BY 12Z FRIDAY. THIS SYSTEM WILL QUICKLY SPREAD LIGHT RAIN
OVER THE REGION THIS EVENING. PRECIP TYPE WITH THIS SYSTEM WILL BE
DETERMINED BY BOUNDARY LAYER TEMPS. MODEL SOUNDINGS AND T925 PROGS
INDICATE PRECIP WILL FALL JUST AS RAIN THROUGH 06Z THEN GRADUALLY
CHANGE TO WET SNOW ACROSS CENTRAL NEW YORK AS COLD AIR BUILDS IN
BEHIND WAVE. SNOW ACCUMS WILL BE HIGHLY ELEVATION DEPENDENT WITH
THE HIGHER ELEVATIONS ACROSS CNTRL NY POSSIBLY GETTING 1 TO 2
INCHES. IN OTSEGO/DELAWARE COUNTIES ACCUMS NEAR 3 INCHES ARE
POSSIBLE. FURTHER SOUTH IN THE WYOMING VALLEY, PIKE AND SULLIVAN
COUNTIES CONDITIONS WILL REMAIN TOO WARM FOR ANY ACCUMS.

LOWS BY DAYBREAK WILL FALL INTO LOWER TO MIDDLE 30S BY READINGS
AROUND 40 IN THE WYOMING VALLEY.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
FRIDAY...SFC WAVE WILL LIFT NORTHEAST QUICKLY WITH ANY REMAINING
ACTIVITY PULLING OUT OF THE EASTERN CWA BY 15Z. BEHIND SYSTEM A
NORTHWEST FLOW OF COLDER AIR WILL DEVELOP WITH HIGHER POPS
ADVERTISED DOWNWIND OF LAKE ONTARIO DUE TO POSSIBLE LES SNOW
SHOWERS. MAX TEMPS WILL RANGE FROM THE MID 30 TO AROUND 40.

FRIDAY NIGHT...SFC HIGH PRES NOSES DOWN FROM EASTERN CANADA WITH
SKIES BECOMING PARTLY CLOUDY. T85 DROPS ENOUGH FOR LES BUT WEAK
FLOW AND FAIRLY DRY AIRMASS WILL LIMIT ANY ACTIVITY. WILL JUST
CONTINUE WITH CHC/SLIGHT CHC POPS IN WESTERLY FLOW. LOWS WILL
RANGE FROM THE UPPER TEENS TO MID 20S.

SATURDAY THROUGH CHRISTMAS...A FAIRLY DRY PERIOD WITH NEAR
SEASONAL TEMPS. A WEAK WARM FRONT TO OUR WEST ON SATURDAY WILL
BRING MORE CLOUDS ACROSS THE AREA BUT ANY PRECIP WILL STAY WELL
WEST/NORTH OF REGION. MAX TEMPS SATURDAY WILL RANGE IN THE 30S.
SATURDAY NIGHT INTO CHRISTMAS, SFC HIGH PRES ALONG THE ATLANTIC
COAST WILL PROVIDE A SLIGHT TEMP MODERATION UNDER SOUTHWEST FLOW.
LATE CHRISTMAS DAY AN APPROACHING TROF WILL BRING A CHANCE FOR
RAIN/SNOW SHOWERS TOWARD EVENING ESPECIALLY IN THE WESTERN FA. MAX
TEMPS ON CHRISTMAS WILL RANGE IN THE MID 30S TO AROUND 40.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MODELS IN SOMEWHAT DECENT AGREEMENT FOR THE EXTENDED FORECAST.
THERE WILL BE AN UPPER LEVEL TROUGH AND A SFC LOW MOVING ACROSS
THE NORTHEASTERN US SUNDAY NIGHT. THIS WILL BRING A CHANCE OF SNOW
TO THE AREA. THIS SYSTEM QUICKLY CLEARS OUT AND HIGH PRESSURE
BUILDS IN FOR TUESDAY. BY TUESDAY NIGHT, A LOW PASSES TO THE NORTH
OF THE CWA AND LOOKS TO JUST BRING SOME CLOUDS TO THE AREA ATTM.
THEN, ANOTHER RIDGE OF HIGH PRESSURE SETS UP FOR WEDNESDAY THROUGH
THURSDAY MORNING. FOR WEDNESDAY NIGHT AND THURSDAY, MODELS DO
DIVERGE SOMEWHAT, WITH THE ECMWF HOLDING ONTO THE HIGH PRESSURE
LONGER THEN THE GFS, WHICH HAS A LOW APPROACHING THE CWA FROM THE
WEST. EITHER WAY, MOST OF THE WEEK LOOKS PRETTY QUIET WEATHER WISE
WITH TEMPS LIKELY ABOVE NORMAL.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
1 AM UPDATE...OUTSIDE OF KAVP...IFR CIGS LIKELY TO DEVELOP ACROSS
ALL TERMINALS OVER THE NEXT FEW HOURS. THE EXACT TIMING OF WHEN
THIS WILL OCCUR STILL A BIT UNCERTAIN BUT OVERALL CONFIDENCE IS
HIGH THAT IFR CIGS WILL DEVELOP. SOME LIFR CIGS ARE POSSIBLE AT
KITH AND KBGM DUE TO THE ELEVATION. GENERALLY SPEAKING VSBYS WILL
REMAIN IN THE MVFR RANGE IN RAIN. GRADUALLY HOWEVER SOME IFR VSBYS
WILL BE POSSIBLE AT THE NY TERMINALS AS THE RAIN CHANGES OVER TO
SNOW BETWEEN 08Z AND 11Z. AT KAVP WITH ALMOST ALL RAIN
EXPECTED...MVFR CIGS AND VSBYS ARE MORE LIKELY. TOWARD 1330Z
HOWEVER A BRIEF CHANGEOVER TO SNOW MAY PRODUCE SOME QUICK IFR
VSBYS.

LATER TODAY GRADUAL IMPROVEMENT TO MVFR BY LATE MORNING AND VFR
THIS AFTERNOON.



.OUTLOOK...

FRIDAY NIGHT/SAT...POSSIBLE MVFR IN SNOW SHOWERS...PRIMARILY NYS.

SATURDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...RRM
NEAR TERM...MLJ/RRM
SHORT TERM...RRM
LONG TERM...SLI
AVIATION...HEDEN







AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 1203 AM EST FRI DEC 23 2011

.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL MOVE INTO THE MID ATLANTIC
REGION OVERNIGHT THEN OFF THE NEW JERSEY COAST BY MORNING. THIS
SYSTEM WILL SPREAD RAIN OVER THE REGION THIS EVENING WHICH WILL
GRADUALLY CHANGE TO WET SNOW OVERNIGHT. MINOR SNOW ACCUMULATIONS
ARE LIKELY ACROSS CENTRAL NEW YORK, ESPECIALLY IN THE HIGHER
TERRAIN. THE REST OF THE HOLIDAY WEEKEND WILL BE COOLER WITH
TEMPERATURES CLOSER TO NORMAL ALONG WITH DRY CONDITIONS.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MIDNIGHT UPDATE...WE HAVE MADE SOME TWEEKS TO THE NEAR TERM. SFC
TEMPS WERE RUNNING A BIT ON THE COOL SIDE AND HAVE RAISED THEM A
FEW DEG OVER THE NXT 3-6 HRS. AS FOR PCPN...WE ARE LEANING TWDS
THE RUC AND OUR LCL WRF WHICH INDICATES A SLIGHTLY LATER CHGOVR
AND THEREFORE LESSER SNOW ACCUMS. DOUBT WE`LL SEE MUCH SNOW S OF
THE NY/PA BORDER...WITH BEST CHC N OF THE NY/PA BORDER ACRS THE
HIER ELEVATIONS OF THE CNTRL SRN TIER/SUSQ RGN WHERE AN INCH IS
PSBL...AND MAYBE 2 0R 3 INCHES OVER ERN DELAWARE COUNTY. PREV BLO...

10 PM UPDATE... PCPN HAS NOW ENVELOPED ALL BUT OUR FAR SERN
ZNS...AND IT SHOULD DEVELOP THERE AS WELL BY ARND 05Z. SAT IMAGERY
SHOWS A WELL DEVELOPED UPR-LVL WV APPROACHING FROM THE SW (AS
EVIDENCED BY NICE BAROCLINIC LEAF SIG)...WITH IMPROVING UPR-LVL
JET DYNAMICS. BEST/STEADIEST PCPN WILL OCCUR BETWEEN NOW AND ABT
10-12Z...WITH A FAIRLY RAPID DEPARTURE FROM SW TO NE THEREAFTER.

SFC TEMPS ARE WELL ABV FRZG ATTM ALL THE WAY BACK TO SRN
ONT...LENDING CREDENCE TO OUR FCST OF ONLY A GRADUAL CHG OVER TO
SNOW DURG THE NGT. WE`LL RIDE WITH OUR CURRENT FCST OF GENERALLY
1-3" OF SNOW (MOSTLY HIGHER ELEVS) ACRS MUCH OF CNY AND PA`S NRN
BORDER CNTYS...WITH LITTLE OR NOTHING DOWN TWDS THE WYO/LACK VLYS.

745 PM UPDATE... STEADIER PCPN IS SLOWLY OVERSPREADING THE AREA
FROM SW TO NE ATTM. THE INITIAL STRIPE OF PCPN SHOULD IMPACT OUR
NRN ZNS (FINGER LAKES RGN)...AS BETTER FGEN FORCING WILL RESIDE
HERE PRIOR TO 06Z. THEREAFTER...PCPN SHOULD RAPIDLY DEVELOP ACRS THE
ENTIRE FA...AS MOIST ADVECTION/UPPER JET DYNAMICS MAXIMIZE IN THE
06-12Z TIME FRAME.

IT CERTAINLY APPEARS THAT BLYR TEMPS WILL DICTATE PTYPE
OVERNIGHT...AS NO WARM LYR SEEMS EVIDENT ON MODEL SNDGS. GIVEN
MILD SFC TEMPS OUT THERE EARLY THIS EVE...IT SHOULD TAKE QUITE A
WHILE FOR SNOW TO MIX IN...SPCLY IN THE VLYS. WE`RE STILL GOING
FOR A CHANGE OVER TO SNOW FROM NW TO SE AFTER 06Z...MAINLY ON THE
HILLTOPS...REACHING THE TWIN TIERS IN THE 09-12Z TIME PD. THE
WYO/LACK VLYS LOOK TO STAY PRIMARILY RAIN FOR THE ENTIRE EVENT.

PREV DISC... A FAIRLY STRONG FAST MOVING WAVE WILL LIFT NORTHEAST
INTO THE MID ATLANTIC REGION BY MIDNIGHT THEN OFF THE NEW JERSEY
COAST BY 12Z FRIDAY. THIS SYSTEM WILL QUICKLY SPREAD LIGHT RAIN
OVER THE REGION THIS EVENING. PRECIP TYPE WITH THIS SYSTEM WILL BE
DETERMINED BY BOUNDARY LAYER TEMPS. MODEL SOUNDINGS AND T925 PROGS
INDICATE PRECIP WILL FALL JUST AS RAIN THROUGH 06Z THEN GRADUALLY
CHANGE TO WET SNOW ACROSS CENTRAL NEW YORK AS COLD AIR BUILDS IN
BEHIND WAVE. SNOW ACCUMS WILL BE HIGHLY ELEVATION DEPENDENT WITH
THE HIGHER ELEVATIONS ACROSS CNTRL NY POSSIBLY GETTING 1 TO 2
INCHES. IN OTSEGO/DELAWARE COUNTIES ACCUMS NEAR 3 INCHES ARE
POSSIBLE. FURTHER SOUTH IN THE WYOMING VALLEY, PIKE AND SULLIVAN
COUNTIES CONDITIONS WILL REMAIN TOO WARM FOR ANY ACCUMS.

LOWS BY DAYBREAK WILL FALL INTO LOWER TO MIDDLE 30S BY READINGS
AROUND 40 IN THE WYOMING VALLEY.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
FRIDAY...SFC WAVE WILL LIFT NORTHEAST QUICKLY WITH ANY REMAINING
ACTIVITY PULLING OUT OF THE EASTERN CWA BY 15Z. BEHIND SYSTEM A
NORTHWEST FLOW OF COLDER AIR WILL DEVELOP WITH HIGHER POPS
ADVERTISED DOWNWIND OF LAKE ONTARIO DUE TO POSSIBLE LES SNOW
SHOWERS. MAX TEMPS WILL RANGE FROM THE MID 30 TO AROUND 40.

FRIDAY NIGHT...SFC HIGH PRES NOSES DOWN FROM EASTERN CANADA WITH
SKIES BECOMING PARTLY CLOUDY. T85 DROPS ENOUGH FOR LES BUT WEAK
FLOW AND FAIRLY DRY AIRMASS WILL LIMIT ANY ACTIVITY. WILL JUST
CONTINUE WITH CHC/SLIGHT CHC POPS IN WESTERLY FLOW. LOWS WILL
RANGE FROM THE UPPER TEENS TO MID 20S.

SATURDAY THROUGH CHRISTMAS...A FAIRLY DRY PERIOD WITH NEAR
SEASONAL TEMPS. A WEAK WARM FRONT TO OUR WEST ON SATURDAY WILL
BRING MORE CLOUDS ACROSS THE AREA BUT ANY PRECIP WILL STAY WELL
WEST/NORTH OF REGION. MAX TEMPS SATURDAY WILL RANGE IN THE 30S.
SATURDAY NIGHT INTO CHRISTMAS, SFC HIGH PRES ALONG THE ATLANTIC
COAST WILL PROVIDE A SLIGHT TEMP MODERATION UNDER SOUTHWEST FLOW.
LATE CHRISTMAS DAY AN APPROACHING TROF WILL BRING A CHANCE FOR
RAIN/SNOW SHOWERS TOWARD EVENING ESPECIALLY IN THE WESTERN FA. MAX
TEMPS ON CHRISTMAS WILL RANGE IN THE MID 30S TO AROUND 40.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MODELS IN SOMEWHAT DECENT AGREEMENT FOR THE EXTENDED FORECAST.
THERE WILL BE AN UPPER LEVEL TROUGH AND A SFC LOW MOVING ACROSS
THE NORTHEASTERN US SUNDAY NIGHT. THIS WILL BRING A CHANCE OF SNOW
TO THE AREA. THIS SYSTEM QUICKLY CLEARS OUT AND HIGH PRESSURE
BUILDS IN FOR TUESDAY. BY TUESDAY NIGHT, A LOW PASSES TO THE NORTH
OF THE CWA AND LOOKS TO JUST BRING SOME CLOUDS TO THE AREA ATTM.
THEN, ANOTHER RIDGE OF HIGH PRESSURE SETS UP FOR WEDNESDAY THROUGH
THURSDAY MORNING. FOR WEDNESDAY NIGHT AND THURSDAY, MODELS DO
DIVERGE SOMEWHAT, WITH THE ECMWF HOLDING ONTO THE HIGH PRESSURE
LONGER THEN THE GFS, WHICH HAS A LOW APPROACHING THE CWA FROM THE
WEST. EITHER WAY, MOST OF THE WEEK LOOKS PRETTY QUIET WEATHER WISE
WITH TEMPS LIKELY ABOVE NORMAL.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
8 PM UPDATE... MVFR CIGS XPCTD THROUGH 03-04Z...EXCEPT FOR
KAVP...WHERE VFR SHOULD HANG ON A BIT LONGER. THEREAFTER...PCPN
WILL DEVELOP AREA-WIDE...WITH LWR MVFR/IFR RESTRICTIONS
ANTICIPATED OVERNIGHT INTO EARLY FRI.

IMPROVEMENT BACK TO VFR IS FCST BY FRI AFTN...WITH LWR LVL DRY AIR
COMING IN FROM THE W BY THIS TIME.

VRBL SFC WINDS ARND 5 KT OVERNIGHT...WILL TURN NW ON FRI AND
INCREASE TO ARND 10 KT.

.OUTLOOK...

FRIDAY NIGHT/SAT...POSSIBLE MVFR IN SNOW SHOWERS...PRIMARILY NYS.

SATURDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...RRM
NEAR TERM...MLJ/RRM
SHORT TERM...RRM
LONG TERM...SLI
AVIATION...MLJ/SLI







AREA FORECAST DISCUSSION

NWS SPOKANE WA

 1003 PM PST Thu Dec 22 2011

.SYNOPSIS...High pressure will flatten and shift east tonight and
Friday as a storm moves into the Pacific Northwest. Some mountains
snow is possible. Stronger storms will be possible through the
holiday weekend and into early next week. Those with travel
interests this weekend can expect snow to develop over the mountain
passes, especially near the Cascades and at times, over the Idaho
Panhandle.


&&

.DISCUSSION...
Update tonight is to lower temperatures further. High clouds are
moving in from the west, but they have been slow to get to extreme
eastern WA and northern ID. Temperatures have dropped quite a bit
where fog and stratus haven`t developed. Looking at the cameras
from across the area, the most widespread fog appears to be in the
Spokane area, especially along I-90 in the valley and Liberty Lake and
along the Spokane River. But once you get east to Post Falls or
north toward Chewelah or Colville, it is all stratus. So, have a
NOWCAST out for the locally dense fog in the Spokane area. Models
are suggesting the fog breaking up and dissipating quite early
tomorrow...around 8am. NAM does suggest the boundary layer
becoming less moist with time overnight and into Friday morning.
Even the HRRR suggests the fog dissipating early.

&&

.AVIATION...
06Z TAFs: The lower level air mass beneath an inversion will remain
very moist tonight in the KGEG vcnty. This will result in low clouds
and fog expanding and impacting KEAT, KMWH, KGEG, KSFF, and KCOE.
The greatest duration of fog and stratus will occur at KGEG and KSFF
where the lower levels remain near saturation.  Drying in the
boundary layer is expected by 16z Friday as winds shift to the south
with stratus expected to clear of the TAF sites but likely remain in
place over the northern valleys.


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        13  28  23  33  24  34 /   0  10  10  30  10  40
Coeur d`Alene   9  31  23  34  25  36 /   0  10  10  30  10  40
Pullman        17  33  27  37  28  40 /   0  10  10  20   0  20
Lewiston       15  35  28  40  29  45 /   0  10   0  10   0  10
Colville       15  30  23  35  23  35 /   0  10  20  40  20  50
Sandpoint      11  30  21  34  23  35 /   0  10  20  50  20  40
Kellogg        16  30  23  35  27  36 /   0  10  10  20  10  30
Moses Lake      7  30  21  34  21  37 /   0  10  10  20   0  20
Wenatchee      12  33  26  35  24  37 /   0  10  10  20  10  30
Omak            9  29  22  35  21  33 /   0  10  10  30  10  40

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&

$$









AREA FORECAST DISCUSSION

NWS GOODLAND KS

 425 AM MST FRI DEC 23 2011

.UPDATE...
317 AM MST FRI DEC 23 2011

IR AND 11-3.9 SATELLITE IMAGES SHOW PATCHY FOG MOVING ACROSS PARTS
OF CHEYENNE COUNTY COLORADO. LIMON DID HAVE SOME BRIEF REDUCTIONS IN VISIBILITY
DOWN TO A QUARTER...BUT LOOKS LIKE THE FOG IS NOT THAT DENSE OVER
CHEYENNE COUNTY. LATEST VSREF AND HRRR SHOW IT MAY MOVE INTO PARTS
OF WALLACE AND GREELEY COUNTY SO WILL INCLUDE THESE THREE COUNTIES
IN A MENTION OF PATCHY FREEZING FOG. THE FREEZING FOG SHOULD
DISSIPATE BY MID MORNING.

JTL
&&

.SHORT TERM (TODAY-CHRISTMAS DAY)...
227 AM MST FRI DEC 23 2011

RATHER TRANQUIL WEATHER WILL BE IN STORE FOR THE TRI-STATE AREA FOR
THE CHRISTMAS WEEKEND.  AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL
REMAIN OVER THE AREA DURING THE PERIOD.  LATE IN THE PERIOD AN UPPER
LEVEL SHORT WAVE TROUGH WILL MOVE THROUGH THE PERIPHERY OF THE RIDGE.
WITH MOST OF THE JET ENERGY NORTH OF THE AREA AND A DRY ENVIRONMENT
IN PLACE...WILL CONTINUE TO LEAVE CHRISTMAS NIGHT DRY.

HIGH TEMPERATURES WILL BE NORMAL TO ABOVE NORMAL THROUGH THE PERIOD
AS WARMER 850MB AIR IS BROUGHT IN BY THE NORTHWEST WINDS.  LOW
TEMPERATURES WILL BE NEAR NORMAL TO BELOW NORMAL FOR TONIGHT THEN
WARM TO EITHER NEAR NORMAL OR ABOVE NORMAL VALUES FOR THE WEEKEND.
SOME UNCERTAINTY EXISTS REGARDING THE EFFECT THE RECENT SNOWFALL
FROM EARLIER THIS WEEK WILL HAVE ON TEMPERATURES.  GENERAL TREND WAS
TO HAVE COOLER TEMPERATURES OVER THE SOUTHERN AND SOUTHEASTERN AREAS
WHERE THE HIGHEST SNOWFALL AMOUNTS WERE REPORTED.

JTL

.LONG TERM (MONDAY-THURSDAY)...
227 AM MST FRI DEC 23 2011

PROGRESSIVE PATTERN WILL BE IN PLACE ACROSS THE CONUS WITH A
SERIES OF FAST MOVING AND WEAK SYSTEMS. THE ONLY ONE THAT APPEARS
TO HAVE EVEN A SLIGHT CHANCE OF BRINGING PRECIPITATION TO THE AREA
WILL BE ON THURSDAY NIGHT...BUT IT WOULD BE VERY LIGHT IF IT
OCCURS AT ALL. DEEP WESTERLY FLOW WILL DOMINATE AND RESULT IN
LIMITED MOISTURE. THERE IS NO COLD AIR IN SIGHT AND TEMPERATURES
WILL BE ABOVE NORMAL THE ENTIRE PERIOD.

024
&&

.AVIATION...
425 AM MST FRI DEC 23 2011

FOR THE 12Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD AT
BOTH TERMINALS. HIGH PRESSURE WILL MOVE FROM THE CENTRAL TO SOUTHERN
HIGH PLAINS RESULTING IN MOSTLY CLEAR SKIES AND LIGHT WEST WINDS.

024
&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&

$$






AREA FORECAST DISCUSSION

NWS GOODLAND KS

 325 AM MST FRI DEC 23 2011

.UPDATE...
317 AM MST FRI DEC 23 2011

IR AND 11-3.9 SATELLITE IMAGES SHOW PATCHY FOG MOVING ACROSS PARTS
OF CHEYENNE COUNTY COLORADO. LIMON DID HAVE SOME BRIEF REDUCTIONS IN VISIBILITY
DOWN TO A QUARTER...BUT LOOKS LIKE THE FOG IS NOT THAT DENSE OVER
CHEYENNE COUNTY. LATEST VSREF AND HRRR SHOW IT MAY MOVE INTO PARTS
OF WALLACE AND GREELEY COUNTY SO WILL INCLUDE THESE THREE COUNTIES
IN A MENTION OF PATCHY FREEZING FOG. THE FREEZING FOG SHOULD
DISSIPATE BY MID MORNING.

JTL
&&

.SHORT TERM (TODAY-CHRISTMAS DAY)...
227 AM MST FRI DEC 23 2011

RATHER TRANQUIL WEATHER WILL BE IN STORE FOR THE TRI-STATE AREA FOR
THE CHRISTMAS WEEKEND.  AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL
REMAIN OVER THE AREA DURING THE PERIOD.  LATE IN THE PERIOD AN UPPER
LEVEL SHORT WAVE TROUGH WILL MOVE THROUGH THE PERIPHERY OF THE RIDGE.
WITH MOST OF THE JET ENERGY NORTH OF THE AREA AND A DRY ENVIRONMENT
IN PLACE...WILL CONTINUE TO LEAVE CHRISTMAS NIGHT DRY.

HIGH TEMPERATURES WILL BE NORMAL TO ABOVE NORMAL THROUGH THE PERIOD
AS WARMER 850MB AIR IS BROUGHT IN BY THE NORTHWEST WINDS.  LOW
TEMPERATURES WILL BE NEAR NORMAL TO BELOW NORMAL FOR TONIGHT THEN
WARM TO EITHER NEAR NORMAL OR ABOVE NORMAL VALUES FOR THE WEEKEND.
SOME UNCERTAINTY EXISTS REGARDING THE EFFECT THE RECENT SNOWFALL
FROM EARLIER THIS WEEK WILL HAVE ON TEMPERATURES.  GENERAL TREND WAS
TO HAVE COOLER TEMPERATURES OVER THE SOUTHERN AND SOUTHEASTERN AREAS
WHERE THE HIGHEST SNOWFALL AMOUNTS WERE REPORTED.

JTL

.LONG TERM (MONDAY-THURSDAY)...
227 AM MST FRI DEC 23 2011

PROGRESSIVE PATTERN WILL BE IN PLACE ACROSS THE CONUS WITH A
SERIES OF FAST MOVING AND WEAK SYSTEMS. THE ONLY ONE THAT APPEARS
TO HAVE EVEN A SLIGHT CHANCE OF BRINGING PRECIPITATION TO THE AREA
WILL BE ON THURSDAY NIGHT...BUT IT WOULD BE VERY LIGHT IF IT
OCCURS AT ALL. DEEP WESTERLY FLOW WILL DOMINATE AND RESULT IN
LIMITED MOISTURE. THERE IS NO COLD AIR IN SIGHT AND TEMPERATURES
WILL BE ABOVE NORMAL THE ENTIRE PERIOD.

024
&&

.AVIATION...
951 PM MST THU DEC 22 2011

FOR THE 06Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH
THE PERIOD AT BOTH TERMINALS. LIGHT WINDS HAVE BACKED THROUGHOUT
THE EVENING...AND WILL BACK SLIGHTLY MORE EARLY IN THE PERIOD AND
BECOME SOUTHWESTERLY. WEST OF KGLD IN COLORADO...THERE IS THE
POTENTIAL FOR FOG OVER THE AREAS THAT RECEIVED SEVERAL INCHES OF
SNOW OVER THE PAST 24 HOURS. AT KGLD...DEW POINTS SHOULD CONTINUE
TO DECREASE AND KEEP VISIBILITIES VFR. WINDS WILL CONTINUE TO BE
LIGHT DURING THE DAYTIME ON FRIDAY...VEERING SLIGHTLY TO WESTERLY.

CJS
&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 1035 AM EST FRI DEC 23 2011

.SYNOPSIS...
NORTHEAST EXITING LOW PRESSURE WILL LEAVE LITTLE MORE THAN DRIZZLE
AND FLURRIES EARLY TODAY. WEAK HIGH PRESSURE WILL PROVIDE DRY
SEASONABLE CONDITIONS FOR CHRISTMAS EVE AND MORNING. A CANADIAN
COLD FRONT MAY BRING RAIN AND SNOW SHOWERS CHRISTMAS NIGHT INTO
MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
15Z ENHANCED SHORT TERM FORECAST HAS BEEN ISSUED TO UPDATE WEATHER
GRIDS WITH PATCHY AREAS OF DRIZZLE ALONG WITH A FEW FLURRIES
POSSIBLE INTO THE EARLY AFTERNOON.

THE LATEST MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO
VALLEY IN A SOUTHWESTERLY FLOW WITH A SHORT WAVE SLIDING
SOUTHEASTWARD ACROSS THE UPPER MIDWEST. AT THE SURFACE, A 1010MB
LOW IS LOCATED ACROSS NORTHERN MINNESOTA WITH A BROAD AREA OF HIGH
PRESSURE EXTENDING FROM THE CENTRAL PLAINS INTO THE OHIO VALLEY.
LINGERING MOISTURE RELATED TO THE LOW THAT BROUGHT PRECIP TO THE
AREA LAST NIGHT IS PULLING EAST OF THE AREA. THUS, SOME LINGERING
PATCHY DRIZZLE AND FLURRIES REMAIN ACROSS THE AREA.

REST OF TODAY...LOW-LEVEL MOISTURE IN THE WAKE OF THE LOW WILL BE
SLOW TO SLIDE EASTWARD ACROSS THE AREA TODAY. THUS, A CLOUDY DAY
CAN BE EXPECTED. WITH THE SUPPORT OF RUC FORECAST SOUNDINGS, PATCHY
DRIZZLE AND FLURRIES ARE FORECAST. A FEW LOCALIZED AREAS ACROSS
THE I-80 CORRIDOR AND EASTERN RIDGES WILL DROP BELOW 32 IN COLD
AIR ADVECTION TODAY AND THUS THE BRIEF MENTION OF FREEZING DRIZZLE
IS IN PLACE THERE. PRECIPITATION WILL BE TOO LIGHT, HOWEVER, TO
LEAD TO ANY ICING. ELSEWHERE, FORECAST IS CLOSEST TO LAMP GUIDANCE
WITH TEMPERATURES FAIRLY STEADY IN THE MID TO UPPER 30S ACROSS THE
AREA.

TONIGHT...A SHORT WAVE WILL SLIDE ACROSS THE LOWER GREAT LAKES
AND INTO THE UPPER OHIO VALLEY. WITH THE SUPPORT OF THE 4KM NAM,
SHORT WAVE MAY HAVE JUST ENOUGH ENERGY TO SQUEEZE OUT A FEW
FLURRIES AS IT PASSES THE AREA. THUS, HAVE ADDED THE CHANCE OF
FLURRIES OVERNIGHT FOR AREAS NORTH OF THE I-70 CORRIDOR AND THE
EASTERN RIDGES. LOWS TONIGHT ARE CLOSE TO MAV GUIDANCE, RANGING
FROM THE LOWER 20S ACROSS THE I-80 CORRIDOR AND EASTERN RIDGES TO
THE UPPER 20S IN PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL WV.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
WEAK MIDWEST HIGH PRESSURE WILL PROVIDE SLOW CLEARING TONIGHT
ACROSS THE UPPER OHIO VALLEY, BUT DO EXPECT A DECENT AMOUNT OF SUNSHINE
FOR SATURDAY CHRISTMAS EVE.

RECENT SREF MODEL OUTPUT SHOWS A CLIPPER-TYPE LOW PRESSURE SYSTEM
MOVING SOUTHEASTWARD THROUGH THE GREAT LAKES CHRISTMAS AFTERNOON
AND NIGHT, WHICH CAN PRODUCE COLD FRONTAL SHOWERS ACROSS THE UPPER
OHIO VALLEY. REGARDING PRECIPITATION TYPE, THE SURFACE LAYER
SHOULD BE WARM ENOUGH FOR IT TO BE RAIN SOUTH, BUT IT COULD BE
EITHER RAIN OR SNOW NORTH, AS GFS AND NAM MOS SUGGEST TEMPERATURES
TO BE NEAR SEASONABLE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
RECENT SREF MODEL OUTPUT SHOWS POST SYSTEM SNOW SHOWERS SHOULD BE
EXITING PAST THE MOUNTAINS MONDAY MORNING. ENSUING MIDWEST HIGH
PRESSURE SHOULD PROVIDE A DRY PERIOD MONDAY AFTERNOON AND NIGHT.

UNCERTAINTY INCREASES STARTING TUESDAY, AS THE UPPER JETSTREAM
FLOW EVOLVES INTO A WAVY ZONAL PATTERN ACROSS U.S.

ECMWF, CMC, AND A COUPLE MEMBERS OF THE GEFS MODEL OUTPUT SHOW AN
OCCLUDED FRONTAL SYSTEM MAY PASS EASTWARD THROUGH THE UPPER OHIO
VALLEY TUESDAY. ITS LIKEWISE POSSIBLE A SIMILAR TYPE SYSTEM MAY
PASS THROUGH THURSDAY OR FRIDAY.

WITH THE RESULTING LACK OF COLD AIR INTRUSION, EXPECT TEMPERATURES
THIS PERIOD TO AVERAGE 5 TO 8 DEGREES WARMER THAN NORMAL.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
CIGS BEGINNING TO LIFT TO MVFR THIS MORNING BUT STILL PERIOD OF IFR
CIGS MOVING SOUTHEAST IN NORTHWEST FLOW. HAVE ADDED A TEMPO GROUP TO
ACCOUNT FOR THIS THROUGH 18-19Z. SPOTTY DRIZZLE OR FLURRIES WILL
LIKEWISE END BY THEN.

MVFR STRATUS SHOULD BECOME SCATTERED BY EVENING, EXCEPT ACROSS THE
I-80 CORRIDOR AND PERHAPS NEAR THE MOUNTAINS WHERE THE STRATUS MAY
NOT DISSIPATE UNTIL LATE TONIGHT.

OUTLOOK...SATURDAY THROUGH TUESDAY...
EXPECT MAINLY VFR SATURDAY INTO MIDDAY SUNDAY. THEN COLD FRONTAL
SHOWERS MAY CAUSE RESTRICTIONS CHRISTMAS SUNDAY AFTERNOON INTO
MIDDAY MONDAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$








AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 620 AM EST FRI DEC 23 2011

.SYNOPSIS...
NORTHEAST EXITING LOW PRESSURE WILL LEAVE LITTLE MORE THAN DRIZZLE
AND FLURRIES THIS MORNING. WEAK HIGH PRESSURE WILL PROVIDE DRY
SEASONABLE CONDITIONS FOR CHRISTMAS EVE AND MORNING. A CANADIAN
COLD FRONT MAY BRING RAIN AND SNOW SHOWERS CHRISTMAS NIGHT INTO
MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BLEND OF RECENT SURFACE AND RADAR DATA ALONG WITH HRRR AND NAM
MODEL OUTPUT SHOW LITTLE MORE THAN SCATTERED DRIZZLE OR FLURRIES
LEFT ACROSS THE UPPER OHIO VALLEY IN THE WAKE OF THE NORTHEAST
EXITING LOW PRESSURE SYSTEM. NAM MODEL PROFILES SHOW DRYING ALOFT
WILL CONTINUE, SO DO NOT EXPECT ANY LAKE-INDUCED INSTABILITY
SHOWER DEVELOPMENT AND HENCE ALL PRECIPITATION TO DRY UP BY
MIDDAY.

LOW LEVEL DRYING WILL BE SLOWER, SO POST SYSTEM CLOUDS WILL LINGER
INTO THE AFTERNOON AND RESTRICT DAYTIME TEMPERATURE RISES TO NO
MORE THAN A COUPLE DEGREES OVER CURRENT READINGS. THIS IDEA
CONTINUES SUPPORTED BY RECENT HRRR VALUES AS WELL AS GFS AND NAM
MOS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
WEAK MIDWEST HIGH PRESSURE WILL PROVIDE SLOW CLEARING TONIGHT
ACROSS THE UPPER OHIO VALLEY, BUT DO EXPECT A DECENT AMOUNT OF SUNSHINE
FOR SATURDAY CHRISTMAS EVE.

RECENT SREF MODEL OUTPUT SHOWS A CLIPPER-TYPE LOW PRESSURE SYSTEM
MOVING SOUTHEASTWARD THROUGH THE GREAT LAKES CHRISTMAS AFTERNOON
AND NIGHT, WHICH CAN PRODUCE COLD FRONTAL SHOWERS ACROSS THE UPPER
OHIO VALLEY. REGARDING PRECIPITATION TYPE, THE SURFACE LAYER
SHOULD BE WARM ENOUGH FOR IT TO BE RAIN SOUTH, BUT IT COULD BE
EITHER RAIN OR SNOW NORTH, AS GFS AND NAM MOS SUGGEST TEMPERATURES
TO BE NEAR SEASONABLE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
RECENT SREF MODEL OUTPUT SHOWS POST SYSTEM SNOW SHOWERS SHOULD BE
EXITING PAST THE MOUNTAINS MONDAY MORNING. ENSUING MIDWEST HIGH
PRESSURE SHOULD PROVIDE A DRY PERIOD MONDAY AFTERNOON AND NIGHT.

UNCERTAINTY INCREASES STARTING TUESDAY, AS THE UPPER JETSTREAM
FLOW EVOLVES INTO A WAVY ZONAL PATTERN ACROSS U.S.

ECMWF, CMC, AND A COUPLE MEMBERS OF THE GEFS MODEL OUTPUT SHOW AN
OCCLUDED FRONTAL SYSTEM MAY PASS EASTWARD THROUGH THE UPPER OHIO
VALLEY TUESDAY. ITS LIKEWISE POSSIBLE A SIMILAR TYPE SYSTEM MAY
PASS THROUGH THURSDAY OR FRIDAY.

WITH THE RESULTING LACK OF COLD AIR INTRUSION, EXPECT TEMPERATURES
THIS PERIOD TO AVERAGE 5 TO 8 DEGREES WARMER THAN NORMAL.

&&

.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
PER BLEND OF RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR,
NAM, AND GFS LAMP MODEL OUTPUT, EXPECT IT STILL MAY BE MIDDAY
BEFORE PREVALENT IFR STRATUS CEILINGS LIFT TO MVFR LEVELS. SPOTTY
DRIZZLE OR FLURRIES WILL LIKEWISE END BY THEN.

STRATUS SHOULD BECOME SCATTERED BY EVENING, EXCEPT ACROSS THE I-80
CORRIDOR AND PERHAPS NEAR THE MOUNTAINS WHERE THE STRATUS MAY NOT
DISSIPATE UNTIL LATE TONIGHT.

OUTLOOK...SATURDAY THROUGH TUESDAY...
EXPECT MAINLY VFR SATURDAY INTO MIDDAY SUNDAY. THEN COLD FRONTAL
SHOWERS MAY CAUSE RESTRICTIONS CHRISTMAS SUNDAY AFTERNOON INTO
MIDDAY MONDAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 631 AM EST FRI DEC 23 2011

UPDATED AVIATION DISCUSSION FOR 12Z TAFS

.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED MID/UPPER LEVEL TROUGHING FROM
NE CANADA INTO THE CNTRL CONUS RESULTING IN NW FLOW FROM CNTRL
CANADA INTO THE GREAT LAKES. A PROMINENT UPSTREAM SHORTWAVE TROUGH
WAS LOCATED NEAR LAKE WINNIPEG. AT THE SFC...SRLY WINDS WERE
INCREASING OVER MN AND WRN LAKE SUPERIOR AHEAD OF LOW PRES OVER THE
SE CORNER OF MANITOBA. THE AREA OF WAA LIGHT SNOW HAD MOVED INTO NRN
MN WITH VSBYS DOWN TO 1-3SM. LINGERING SCT LIGHT LAKE EFFECT SNOW
SHOWERS OVER ERN LAKE SUPERIOR WERE QUICKLY DIMINISHING AND STARING
TO MOVE OFFSHORE AS THE RIDGE AXIS MOVES THROUGH AND WINDS BACK TO
THE SW.
&&

.DISCUSSION...

TODAY AND TONIGHT...EXPECT THE AREA OF SNOW TO MAKE STEADY PROGRESS
TO THE SE AS THE MANTITOBA CLIPPER SHORTWAVE AND LOW APPROACH THE
AREA. THE BAND OF MODERATE TO STRONG NET 280K ISENTROPIC ASCENT AND
700-300 MB QVECTOR CONV WILL SUPPORT GOING HIGHER END POPS ACROSS THE
CWA...MAINLY BTWN 18Z-24Z. HOWEVER...MOISTURE WILL BE LIMITED WITH
ONLY 1.0 1O 1.5 G/KG AVAILABLE IN THE 700-750 MB LAYER AND PWAT
VALUES OF AROUND 0.25 INCH. SO...ACCUMULATIONS SHOULD REMAIN
GENERALLY LIGHT...AT OR BELOW AN INCH. DOWNSLOPE SRLY FLOW MAY ALSO
REDUCE AMOUNTS NEAR LAKE SUPERIOR IN NORTH CENTRAL UPPER MI. 850 MB
TEMPS AROUND -10C SUPPORT POTENTIAL FOR SOME LAKE ENHANCED SNOW NEAR
LAKE MICHIGAN. WITH ONLY A BRIEF PERIOD OF DEEPER MOISTURE/LIFT
MOVING THROUGH ANY ADDITIONAL AMOUNTS WILL ALSO BE SMALL. THE BEST
CHANCE FOR MORE SIGNIFICANT SNOW AMOUNTS WILL BE EAST OF
MANISTIQUE...GIVEN PREDOMINANT 220-230 CBL FLOW LATE THIS AFTERNOON
AND EVENING.

WITH ONLY MODERATE INSTABILITY...THE SNOW WILL DIMINISH QUICKLY OVER
FROM WEST TO EAST IN THE EVENING AS THE SHORTWAVE MOVES THROUGH AND
SUBSIDENCE TAKES OVER. CLOUDS MAY ALSO DIMINISH LATE AS 925-850 MB
WEST FLOW DRY ADVECTION MOVES IN.

SATURDAY...DRY WEATHER IS EXPECTED AS THE FORCING AND ISENTROPIC
NEXT WEAKER CLIPPER SHRTWV IS EXPECTED TO REMAIN NORTH OF THE
CWA...PER GFS/ECMWF/GEM. WAA WILL BRING A REBOUND IN TEMPS BACK INTO
THE UPPER 20S AND LOWER 30S.

SATURDAY NIGHT INTO SUNDAY...A SLIGHTLY STRONGER SHRTWV WILL MOVE
THROUGH THE WESTERN GREAT LAKES LATE SAT NIGHT INTO EARLY SUN.
THERE WAS GREATER UNCERTAINTY WITH POTENTIAL FOR LIGHT SYNOPTIC
LIGHT SNOW. THE GFS WAS FARTHER SOUTH WITH THIS FEATURE COMAPRED TO
THE ECMWF/GEM. WITH LITTLE MOISTURE AVBL...CHANCE POPS WERE CONFINED
TO LOCATIONS FAVORED BY WNW FLOW WHERE SOME LAKE ENHANCEMENT MAY
OCCUR WITH 850 MB TEMPS AROUND -10C.

MONDAY THROUGH THURSDAY...MID LEVEL RIDGING BUILD INTO THE AREA WITH
STRGER SW FLOW MON...BOOSTING TEMPS WELL ABOVE NORMAL...INTO THE MID
TO UPPER 30S. THE MILD PATTERN CONTINUES THROUGH MUCH OF THE WEEK
WITH ADDITIONAL CLIPPER SYSTEMS MOVING THROUGH. UNCERTAINTY IS
LARGER WITH STRENGTH OF CAA IN THE WAKE OF ANY SYSTEM. THE 00Z
GFS/GEM AND MAJORITY OF GFS ENS SUGGESTED THAT COLD AIR BY TUE INTO
TUE NIGHT WOULD REMAIN ONLY NEAR -10C WHILE THE 00Z ECMWF FCST H8
TEMPS DOWN TO -15C WHICH WOULD BRING GREATER CHANCE FOR SIGNFICANT
LES.
&&

.AVIATION /FOR THE 12Z TAF ISSUANCE/...

A CLIPPER SYSTEM DROPPING SE ACROSS UPPER MICHIGAN WILL SPREAD SNOW
ACROSS THE AREA FROM WEST TO EAST LATE THIS MORNING THROUGH EARLY
EVENING. HAVE CONTINUED ALT LANDING MINS FOR ALL SITES DURING THE
PEAK SNOW IN THE AFTN HRS. AS THE SYSTEM EXITS...EXPECT BORDERLINE
IFR CIGS TO CONTINUE BEFORE DIMINISHING OVERNIGHT. MODELS HINTING AT
LOW CLOUDS THROUGH A GOOD PORTION OF THE NIGHT AND WOULD HAVE LIKED
TO HAVE SEEN A LITTLE DEEPER MOISTURE TO GO WITH LOW CIGS AND SOME
VSBY REDUCTION AFTER 06Z.
&&

.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...

WITH MODELS COMING TO A CONSENSUS ON LOW TRACK/INTENSITY ACROSS LAKE
SUPERIOR TODAY...HAVE ADJUSTED WINDS DOWN A TOUCH AND ONLY THINK
THERE WILL BE A PERIOD /LATE MORNING THROUGH THE AFTN/ OF SW GUSTS
UP TO 30KTS AHEAD OF THE LOW. WINDS SHOULD DIMINISH BELOW 20KTS
TONIGHT AS THE LOW DISSIPATES WHEN MOVING INTO THE LOWER GREAT
LAKES. SW WINDS WILL ONCE AGAIN BE ON THE INCREASE SAT AHEAD OF THE
NEXT TROUGH TO AFFECT LK SUPERIOR. THIS STRONGER TROUGH WILL PRODUCE
WINDS UP TO 30KTS SAT INTO SUN...AS WINDS GRADUALLY SHIFT TO THE NW
BY SUN WITH THE TROUGH PUSHING EAST. THERE COULD BE A FEW ISOLATED
GALE FORCE GUSTS TO 35KTS DURING THAT PERIOD. AFTER A BRIEF REPRIVE
ON SUN NIGHT...THE NEXT TROUGH WILL AFFECT LK SUPERIOR MON INTO MON
NIGHT. WITH THIS TROUGH EVEN STRONGER...APPEARS TO BE A GOOD CHANCE
OF SEEING SW GALES TO 35KTS OVER MUCH OF LAKE SUPERIOR MON
AFTN/NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$


SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...SRF
MARINE...SRF







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 546 AM EST FRI DEC 23 2011

.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED MID/UPPER LEVEL TROUGHING FROM
NE CANADA INTO THE CNTRL CONUS RESULTING IN NW FLOW FROM CNTRL
CANADA INTO THE GREAT LAKES. A PROMINENT UPSTREAM SHORTWAVE TROUGH
WAS LOCATED NEAR LAKE WINNIPEG. AT THE SFC...SRLY WINDS WERE
INCREASING OVER MN AND WRN LAKE SUPERIOR AHEAD OF LOW PRES OVER THE
SE CORNER OF MANITOBA. THE AREA OF WAA LIGHT SNOW HAD MOVED INTO NRN
MN WITH VSBYS DOWN TO 1-3SM. LINGERING SCT LIGHT LAKE EFFECT SNOW
SHOWERS OVER ERN LAKE SUPERIOR WERE QUICKLY DIMINISHING AND STARING
TO MOVE OFFSHORE AS THE RIDGE AXIS MOVES THROUGH AND WINDS BACK TO
THE SW. &&

.DISCUSSION...

TODAY AND TONIGHT...EXPECT THE AREA OF SNOW TO MAKE STEADY PROGRESS
TO THE SE AS THE MANTITOBA CLIPPER SHORTWAVE AND LOW APPROACH THE
AREA. THE BAND OF MODERATE TO STRONG NET 280K ISENTROPIC ASCENT AND
700-300 MB QVECTOR CONV WILL SUPPORT GOING HIGHER END POPS ACROSS THE
CWA...MAINLY BTWN 18Z-24Z. HOWEVER...MOISTURE WILL BE LIMITED WITH
ONLY 1.0 1O 1.5 G/KG AVAILABLE IN THE 700-750 MB LAYER AND PWAT
VALUES OF AROUND 0.25 INCH. SO...ACCUMULATIONS SHOULD REMAIN
GENERALLY LIGHT...AT OR BELOW AN INCH. DOWNSLOPE SRLY FLOW MAY ALSO
REDUCE AMOUNTS NEAR LAKE SUPERIOR IN NORTH CENTRAL UPPER MI. 850 MB
TEMPS AROUND -10C SUPPORT POTENTIAL FOR SOME LAKE ENHANCED SNOW NEAR
LAKE MICHIGAN. WITH ONLY A BRIEF PERIOD OF DEEPER MOISTURE/LIFT
MOVING THROUGH ANY ADDITIONAL AMOUNTS WILL ALSO BE SMALL. THE BEST
CHANCE FOR MORE SIGNIFICANT SNOW AMOUNTS WILL BE EAST OF
MANISTIQUE...GIVEN PREDOMINANT 220-230 CBL FLOW LATE THIS AFTERNOON
AND EVENING.

WITH ONLY MODERATE INSTABILITY...THE SNOW WILL DIMINISH QUICKLY OVER
FROM WEST TO EAST IN THE EVENING AS THE SHORTWAVE MOVES THROUGH AND
SUBSIDENCE TAKES OVER. CLOUDS MAY ALSO DIMINISH LATE AS 925-850 MB
WEST FLOW DRY ADVECTION MOVES IN.

SATURDAY...DRY WEATHER IS EXPECTED AS THE FORCING AND ISENTROPIC
NEXT WEAKER CLIPPER SHRTWV IS EXPECTED TO REMAIN NORTH OF THE
CWA...PER GFS/ECMWF/GEM. WAA WILL BRING A REBOUND IN TEMPS BACK INTO
THE UPPER 20S AND LOWER 30S.

SATURDAY NIGHT INTO SUNDAY...A SLIGHTLY STRONGER SHRTWV WILL MOVE
THROUGH THE WESTERN GREAT LAKES LATE SAT NIGHT INTO EARLY SUN.
THERE WAS GREATER UNCERTAINTY WITH POTENTIAL FOR LIGHT SYNOPTIC
LIGHT SNOW. THE GFS WAS FARTHER SOUTH WITH THIS FEATURE COMAPRED TO
THE ECMWF/GEM. WITH LITTLE MOISTURE AVBL...CHANCE POPS WERE CONFINED
TO LOCATIONS FAVORED BY WNW FLOW WHERE SOME LAKE ENHANCEMENT MAY
OCCUR WITH 850 MB TEMPS AROUND -10C.

MONDAY THROUGH THURSDAY...MID LEVEL RIDGING BUILD INTO THE AREA WITH
STRGER SW FLOW MON...BOOSTING TEMPS WELL ABOVE NORMAL...INTO THE MID
TO UPPER 30S. THE MILD PATTERN CONTINUES THROUGH MUCH OF THE WEEK
WITH ADDITIONAL CLIPPER SYSTEMS MOVING THROUGH. UNCERTAINTY IS
LARGER WITH STRENGTH OF CAA IN THE WAKE OF ANY SYSTEM. THE 00Z
GFS/GEM AND MAJORITY OF GFS ENS SUGGESTED THAT COLD AIR BY TUE INTO
TUE NIGHT WOULD REMAIN ONLY NEAR -10C WHILE THE 00Z ECMWF FCST H8
TEMPS DOWN TO -15C WHICH WOULD BRING GREATER CHANCE FOR SIGNFICANT
LES.
&&

.AVIATION /FOR THE 06Z TAF ISSUANCE/...

ALTHOUGH THERE WL BE QUITE A BIT OF CLD COVER...EXPECT VFR
CONDITIONS TO PERSIST THRU LATE MRNG AT ALL 3 SITES WITH RELATIVELY
DRY LLVL AIR UNDER WEAK SFC RDG AXIS. AS THE NEXT CLIPPER LO PRES
NOW IN SCNTRL CAN AND ACCOMPANYING AREA OF -SN MOVES TOWARD THE UPR
LKS LATER TDAY...EXPECT DETERIORATING CONDITIONS TO MVFR THEN IFR
ALONG WITH A GUSTY S WIND. ALTHOUGH THE STEADIER SN WL END W-E LATE
IN THE DAY...LO CLDS AND NO BETTER THAN MVFR CONDITIONS WL LINGER.
&&

.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...

WITH MODELS COMING TO A CONSENSUS ON LOW TRACK/INTENSITY ACROSS LAKE
SUPERIOR TODAY...HAVE ADJUSTED WINDS DOWN A TOUCH AND ONLY THINK
THERE WILL BE A PERIOD /LATE MORNING THROUGH THE AFTN/ OF SW GUSTS
UP TO 30KTS AHEAD OF THE LOW. WINDS SHOULD DIMINISH BELOW 20KTS
TONIGHT AS THE LOW DISSIPATES WHEN MOVING INTO THE LOWER GREAT
LAKES. SW WINDS WILL ONCE AGAIN BE ON THE INCREASE SAT AHEAD OF THE
NEXT TROUGH TO AFFECT LK SUPERIOR. THIS STRONGER TROUGH WILL PRODUCE
WINDS UP TO 30KTS SAT INTO SUN...AS WINDS GRADUALLY SHIFT TO THE NW
BY SUN WITH THE TROUGH PUSHING EAST. THERE COULD BE A FEW ISOLATED
GALE FORCE GUSTS TO 35KTS DURING THAT PERIOD. AFTER A BRIEF REPRIVE
ON SUN NIGHT...THE NEXT TROUGH WILL AFFECT LK SUPERIOR MON INTO MON
NIGHT. WITH THIS TROUGH EVEN STRONGER...APPEARS TO BE A GOOD CHANCE
OF SEEING SW GALES TO 35KTS OVER MUCH OF LAKE SUPERIOR MON
AFTN/NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$


SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...KC
MARINE...SRF







AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 953 AM EST FRI DEC 23 2011

.SYNOPSIS...
LOW PRESSURE OFF THE NEW ENGLAND COAST WILL MOVE AWAY FROM THE AREA
TODAY...WITH RAIN AND SNOW TAPERING OFF THIS MORNING. A SERIES OF
WEAK UPPER LEVEL DISTURBANCES WILL BRING PERIODS OF CLOUDS TO THE
AREA THIS HOLIDAY WEEKEND BUT DRY WEATHER IS EXPECTED. A STRONGER
SYSTEM WILL APPROACH SUNDAY NIGHT WITH A BETTER CHANCE FOR SNOW
SHOWERS.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE 10 AM...KBGM RADAR SHOWS WEAK RETURNS OVER NRN CWA AND
PARTS OF THE SUSQU REGION. ACTIVITY STILL PRIMARILY RAIN WITH A
RAIN/SNOW MIX IN THE HIGHER ELEVATIONS. WILL CONTINUE TO ADVERTISE
CHC POPS ACROSS MUCH OF CENTRAL NY THROUGH MIDDAY THEN JUST CHC
DOWNWIND OF LAKE ONTARIO THIS AFTERNOON IN POSSIBLE WEAK LAKE
EFFECT RESPONSE. TWEAKED WX GRIDS TO INDICATE RAIN/SNOW SHOWER MIX
WITH TRANSITION TO JUST SNOW SHOWERS NOT UNTIL EARLY AFTERNOON. NO
SNOW ACCUM EXPECTED. TEMPS WILL HOLD NEARLY STEADY THROUGH LATE
MORNING THEN SLOWLY DROP THIS AFTERNOON IN BETTER CAA.

UPDATED AT 620 AM...TWEEKS TO CRNT FCST WHICH APPEARS TO BE ON
TRACK. STEADIER PCPN IS MOVG OUT ABOUT AN HOUR AHEAD OF SCHEDULE...AND
HAVE LOWERED POPS ACCORDINGLY. NEVER DID COMPLETELY SWITCHOVER TO
SNOW ON THE HILL AT BGM! PREV BLO...

HEAVIEST PCPN IS ALREADY BEGINNING TO MOVE OUT OF THE RGN. PEO AND
DSV REPRTING -SN AND WE`RE MIXING OVER AT BGM AT 3 AM. WE SUSPECT
THAT IS IS ALSO SNOWING ACRS THE HIGHER ELEVATIONS OF THE WRN
CATSKILLS. ACTIVITY WILL CONTINUE TO WIND DOWN THIS MORNING. WILL
CONTINUE TO TWEEKS GRIDS AS NEEDED DURING THE MORNING CHGOVR...BUT
THINK CRNT FCST SNOW AMTS ARE IN THE BALLPARK...WITH BEST CHC N OF
THE NY/PA BORDER ACRS THE HIER ELEVATIONS OF THE CNTRL SRN
TIER/SUSQ RGN WHERE AN INCH IS PSBL...AND MAYBE 2 0R 3 INCHES OVER
ERN DELAWARE COUNTY. LATER TDA AS A CLDER NW FLOW SETS UP...WE
SHOULD SEE A WEAK LAKE RESPONSE WITH SCT -SHSN AND FLURRIES. THIS
ACTIVITY IS XPCTD TO DIMINISH EARLY THIS EVNG. TEMPS TDA STEADY OR
SLOWLY FALLING FROM EARLY MRNG READINGS WITH MINS TNGT GNRLY IN
THE TEENS.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
THIS PERIOD WILL SEE NW FLOW ALOFT WITH WEAK EMBEDDED...MOSTLY
MOISTURE STARVED S/WV`S. ONE PASSES FRI NGT...ANOTHER SAT NGT AND
A STRONGER ONE FOR SUN NGT. MAIN EFFECT OF THE FIRST FEW WAVES
WILL BE TO BRING PDS OF CLOUDINESS TO THE RGN..,BUT THE MORE
POTENT SUNDAY NGT WAVE COULD SPREAD SNOW SHOWERS INTO THE AREA.
ALL IN ALL A VERY QUIET HOLIDAY WEEKEND WITH A MODERATING TEMPS ON
SUNDAY.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
3 AM UPDATE...WE START OFF THE LONG TERM PERIOD WITH A BRIEF PERIOD OF LAKE
EFFECT SNOW EARLY MONDAY BEFORE THE COLDER AIR QUICKLY LIFTS OUT.
PREFER HPC GUIDANCE WHICH LEANS HEAVILY TOWARD THE EURO WHICH IS
MUCH MORE AMPLIFIED AND WARMER THAN THE GFS WITH A COLD FRONT
MOVING TOWARD OUR AREA ON TUESDAY. THIS PATTERN SEEMS TO MAKE THE
MOST SENSE GIVEN OUR PROGRESSIVE...SOUTHWESTERLY FLOW THAT WE HAVE
BEEN IN FOR AWHILE NOW. AFTER ANY SHOWERS TUESDAY...BEHIND THE
FRONT WE DO TURN COLD ENOUGH FOR A PERIOD OF LIGHT SNOW TUESDAY
NIGHT. WE WILL BE BRIEFLY COLD ENOUGH FOR LAKE SNOWS EARLY
WEDNESDAY BEFORE HIGH PRESSURE BRINGS A RETURN TO DRIER WEATHER.

&&

.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
7 AM UPDATE...PRECIPITATION WILL CONTINUE TO PULL OUT OF THE AREA
BY 15Z WITH SLOW IMPROVEMENT EXPECTED AS THIS HAPPENS. IN THE
MEANTIME SOME IFR VSBYS POSSIBLE AT KRME IN SNOW...WITH MVFR VSBYS
AT KSYR IN A RAIN/SNOW MIX. FARTHER SOUTH BOTH KITH AND KBGM HAVE
SEEN CLOUD BASES DROP LOW ENOUGH TO PRODUCE PERIODS OF LIFR CIGS
AND VSBYS AT TIMES. FEEL THIS WILL CONTINUE FOR A FEW MORE HOURS
BEFORE GRADUALLY IMPROVING TO IFR AND EVENTUALLY MVFR BY LATE
MORNING/EARLY AFTERNOON. MVFR CIGS EXPECTED TO CONTINUE AT KELM
AND KAVP THROUGH LATE MORNING BUT THESE TERMINALS ARE EXPECTED TO
STAY DRY.

BY AFTERNOON CONFIDENCE LOWERS AS HIGHER RESOLUTION MODELS SUCH AS
THE HRRR CONTINUE TO SHOW MVFR CIGS AT ALL TERMINALS THROUGH
22Z...WHILE NAM BUFKIT SOUNDINGS...WHICH USUALLY OVERDO THE
MOISTURE...SHOW VFR CIGS RETURNING DURING THIS TIME. WITH A COLD
NORTHWEST FLOW BELIEVE THE HRRR WILL BE CORRECT AND KEEP MVFR
GOING THROUGH 22Z BEFORE VFR RETURNS BY 0Z.



.OUTLOOK...

SAT/SUN...VFR.
SUN NIGHT INTO MONDAY...MVFR POSSIBLE IN LIGHT SNOW.
LATER MONDAY INTO MONDAY NIGHT...VFR.
TUE...MVFR IN RAIN SHOWERS.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...RRM
SHORT TERM...
LONG TERM...HEDEN
AVIATION...HEDEN







AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 650 AM EST FRI DEC 23 2011

.SYNOPSIS...
LOW PRESSURE OFF THE NEW ENGLAND COAST WILL MOVE AWAY FROM THE AREA
TODAY...WITH RAIN AND SNOW TAPERING OFF THIS MORNING. A SERIES OF
WEAK UPPER LEVEL DISTURBANCES WILL BRING PERIODS OF CLOUDS TO THE
AREA THIS HOLIDAY WEEKEND BUT DRY WEATHER IS EXPECTED. A STRONGER
SYSTEM WILL APPROACH SUNDAY NIGHT WITH A BETTER CHANCE FOR SNOW
SHOWERS.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATED AT 620 AM...TWEEKS TO CRNT FCST WHICH APPEARS TO BE ON
TRACK. STEADIER PCPN IS MOVG OUT ABOUT AN HOUR AHEAD OF SCHEDULE...AND
HAVE LOWERED POPS ACCORDINGLY. NEVER DID COMPLETELY SWITCHOVER TO
SNOW ON THE HILL AT BGM! PREV BLO...

HEAVIEST PCPN IS ALREADY BEGINNING TO MOVE OUT OF THE RGN. PEO AND
DSV REPRTING -SN AND WE`RE MIXING OVER AT BGM AT 3 AM. WE SUSPECT
THAT IS IS ALSO SNOWING ACRS THE HIGHER ELEVATIONS OF THE WRN
CATSKILLS. ACTIVITY WILL CONTINUE TO WIND DOWN THIS MORNING. WILL
CONTINUE TO TWEEKS GRIDS AS NEEDED DURING THE MORNING CHGOVR...BUT
THINK CRNT FCST SNOW AMTS ARE IN THE BALLPARK...WITH BEST CHC N OF
THE NY/PA BORDER ACRS THE HIER ELEVATIONS OF THE CNTRL SRN
TIER/SUSQ RGN WHERE AN INCH IS PSBL...AND MAYBE 2 0R 3 INCHES OVER
ERN DELAWARE COUNTY. LATER TDA AS A CLDER NW FLOW SETS UP...WE
SHOULD SEE A WEAK LAKE RESPONSE WITH SCT -SHSN AND FLURRIES. THIS
ACTIVITY IS XPCTD TO DIMINISH EARLY THIS EVNG. TEMPS TDA STEADY OR
SLOWLY FALLING FROM EARLY MRNG READINGS WITH MINS TNGT GNRLY IN
THE TEENS.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
THIS PERIOD WILL SEE NW FLOW ALOFT WITH WEAK EMBEDDED...MOSTLY
MOISTURE STARVED S/WV`S. ONE PASSES FRI NGT...ANOTHER SAT NGT AND
A STRONGER ONE FOR SUN NGT. MAIN EFFECT OF THE FIRST FEW WAVES
WILL BE TO BRING PDS OF CLOUDINESS TO THE RGN..,BUT THE MORE
POTENT SUNDAY NGT WAVE COULD SPREAD SNOW SHOWERS INTO THE AREA.
ALL IN ALL A VERY QUIET HOLIDAY WEEKEND WITH A MODERATING TEMPS ON
SUNDAY.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
3 AM UPDATE...WE START OFF THE LONG TERM PERIOD WITH A BRIEF PERIOD OF LAKE
EFFECT SNOW EARLY MONDAY BEFORE THE COLDER AIR QUICKLY LIFTS OUT.
PREFER HPC GUIDANCE WHICH LEANS HEAVILY TOWARD THE EURO WHICH IS
MUCH MORE AMPLIFIED AND WARMER THAN THE GFS WITH A COLD FRONT
MOVING TOWARD OUR AREA ON TUESDAY. THIS PATTERN SEEMS TO MAKE THE
MOST SENSE GIVEN OUR PROGRESSIVE...SOUTHWESTERLY FLOW THAT WE HAVE
BEEN IN FOR AWHILE NOW. AFTER ANY SHOWERS TUESDAY...BEHIND THE
FRONT WE DO TURN COLD ENOUGH FOR A PERIOD OF LIGHT SNOW TUESDAY
NIGHT. WE WILL BE BRIEFLY COLD ENOUGH FOR LAKE SNOWS EARLY
WEDNESDAY BEFORE HIGH PRESSURE BRINGS A RETURN TO DRIER WEATHER.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
7 AM UPDATE...PRECIPITATION WILL CONTINUE TO PULL OUT OF THE AREA
BY 15Z WITH SLOW IMPROVEMENT EXPECTED AS THIS HAPPENS. IN THE
MEANTIME SOME IFR VSBYS POSSIBLE AT KRME IN SNOW...WITH MVFR VSBYS
AT KSYR IN A RAIN/SNOW MIX. FARTHER SOUTH BOTH KITH AND KBGM HAVE
SEEN CLOUD BASES DROP LOW ENOUGH TO PRODUCE PERIODS OF LIFR CIGS
AND VSBYS AT TIMES. FEEL THIS WILL CONTINUE FOR A FEW MORE HOURS
BEFORE GRADUALLY IMPROVING TO IFR AND EVENTUALLY MVFR BY LATE
MORNING/EARLY AFTERNOON. MVFR CIGS EXPECTED TO CONTINUE AT KELM
AND KAVP THROUGH LATE MORNING BUT THESE TERMINALS ARE EXPECTED TO
STAY DRY.

BY AFTERNOON CONFIDENCE LOWERS AS HIGHER RESOLUTION MODELS SUCH AS
THE HRRR CONTINUE TO SHOW MVFR CIGS AT ALL TERMINALS THROUGH
22Z...WHILE NAM BUFKIT SOUNDINGS...WHICH USUALLY OVERDO THE
MOISTURE...SHOW VFR CIGS RETURNING DURING THIS TIME. WITH A COLD
NORTHWEST FLOW BELIEVE THE HRRR WILL BE CORRECT AND KEEP MVFR
GOING THROUGH 22Z BEFORE VFR RETURNS BY 0Z.



.OUTLOOK...

SAT/SUN...VFR.
SUN NIGHT INTO MONDAY...MVFR POSSIBLE IN LIGHT SNOW.
LATER MONDAY INTO MONDAY NIGHT...VFR.
TUE...MVFR IN RAIN SHOWERS.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...HEDEN
AVIATION...HEDEN







AREA FORECAST DISCUSSION

NWS WILMINGTON NC

 630 AM EST FRI DEC 23 2011

.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING. HIGH PRESSURE
WILL BUILD IN LATER TODAY AND PREVAIL THROUGH SUNDAY MORNING. A
QUICK MOVING SYSTEM WILL BRING A CHANCE OF RAIN LATE CHRISTMAS
DAY...WITH ANOTHER POTENTIAL RAIN-MAKER TUESDAY. NEXT WEEK WILL
FEATURE SEASONABLE TEMPERATURES.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...MILD WEATHER WILL LAST ONE MORE DAY BEFORE
COOLER AND MORE SEASONABLE AIR MOVES IN BEHIND AN EASTWARD-MOVING
COLD FRONT. THIS FRONT IS CURRENTLY LOCATED ACROSS THE CENTRAL
CAROLINAS INTO EASTERN GEORGIA...AND SHOULD MOVE INTO THE EASTERN
CAROLINAS LATER THIS MORNING AND OFFSHORE THIS AFTERNOON.
UPSTAIRS...A SHORTWAVE TROUGH WILL LARGELY SHEAR OUT AS IT PUSHES
ACROSS THE MID-ATLANTIC TODAY.

CHANCES FOR SIGNIFICANT RAINFALL EVENT ARE LOOKING PRETTY SLIM AS
MID-LEVEL MOISTURE IS THINNING AS THE FRONT MOVES EAST AND THE UPPER
LEVEL DYNAMICS ARE NOT PARTICULARLY SUPPORTIVE EITHER. RADAR
COMPOSITES LOOK VERY ANEMIC...AND THE HRRR SHOWS ONLY A COUPLE HOUR
LONG WINDOW FOR POTENTIAL REDEVELOPMENT OF SHOWERS ALONG THE
IMMEDIATE COAST LATE THIS MORNING. THE SREF 6-HOUR POP FOR RAINFALL
EQUAL OR GREATER THAN 0.10 INCH IS LESS THAN 10 PERCENT TODAY. THE
DAYTIME "POP" IN OUR FORECAST IS DEFINED AS THE PROBABILITY OF 0.01
INCHES OR MORE OF RAIN FALLING WITHIN THE 12-HOUR PERIOD 7 AM TO 7
PM...SO EVEN 20-30 PERCENT NUMBERS HERE DO NOT NECESSARILY TRANSLATE
TO ANY SIGNIFICANT RAINFALL FROM A HYDROLOGICAL...AGRICULTURAL OR
PUBLIC STANDPOINT.

WITH THE FRONT EXPECTED TO BE TRAVERSING THE AREA DURING THE LATE
MORNING HOURS HIGH TEMPERATURES SHOULD RANGE FROM 69-74 AT THE COAST
TO 67-70 INLAND. DRIER AND COOLER AIR ADVECTING ACROSS THE AREA THIS
EVENING WILL CLEAR THE SKIES AND ALLOW TEMPERATURES TO FALL INTO THE
40-45 RANGE...MUCH CLOSER TO (BUT STILL ABOVE) NORMAL VALUES FOR
THIS TIME OF YEAR.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...MAIN FEATURE WILL BE THE SHEARED SHORTWAVE
MOVING QUICKLY ACROSS THE AREA LATE CHRISTMAS DAY. CONTINUED TO LEAN
TOWARD THE GFS WHICH SHOWS QPF DEVELOPING QUICKLY WEST TO EAST
SUNDAY AFTERNOON AND CONTINUING THROUGH EARLY EVENING QUICKLY COMING
TO AN END BY MONDAY MORNING. THE OMEGA IS PRIMARILY FROM THE RIGHT
ENTRANCE REGION OF A 300MB JET. TOTAL QPF HAS TRENDED LOWER WITH THE
GFS SHOWING AN AXIS OF APPROXIMATELY HALF OF AN INCH ACROSS SOUTHERN
AREAS BY MONDAY MORNING (24 HOUR). THIS IS USUALLY ON THE HIGH SIDE
AND WITH SOME OF THE GENERATED MOISTURE NEEDED TO SATURATE LOWER
LEVELS...WE MAY DO WELL TO SEE ONE THIRD OF AN INCH. OTHERWISE...
SATURDAY LOOKS PARTLY TO MOSTLY SUNNY WITH A COOL START TO CHRISTMAS
DAY. TEMPERATURE GUIDANCE HAS TRENDED LOWER FOR SUNDAY MORNING WITH
GOOD RADIATIONAL CONDITIONS AND I FAVORED THE COOLER MAV NUMBERS FOR
CHRISTMAS DAY.


&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...FOCUS REMAINS ON THE SOUTHERN STREAM AND A
SYSTEM POSSIBLY MOVING ACROSS TUESDAY INTO WEDNESDAY. THE LATEST GFS
HAS INTRODUCED A NEW IDEA OF KEEPING A PIECE OF ENERGY BEHIND LATE
SUNDAY THAT EVENTUALLY GETS KICKED OUT TUESDAY. THIS HAS TRENDED
TOWARD THE ECMWF SOLUTION. CERTAINLY INTERESTING AND WITH HPC AS
WELL AS ADJACENT OFFICES NOT YET ON BOARD...WILL KEEP FORECAST
BASICALLY DRY WITH THE CAVEAT THAT THE TUESDAY FORECAST COULD CHANGE
CONSIDERABLY. ALL OF THIS SAID...I DID TREND UP POPS SLIGHTLY FOR
TUESDAY TO AT LEAST HINT OF THIS ALTHOUGH THEY GENERALLY REMAIN
BELOW MENTION IN MOST AREAS. SAME GOES FOR DEWPOINTS AND CLOUDCOVER.
NO OTHER CHANGES. DRY WITH TEMPERATURES NEAR CLIMATOLOGY AFTER THIS
EVENT.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...CURRENTLY VFR CONDITIONS CONTINUE AT ALL TAF SITES
EXCEPT FOR CEILINGS WHICH ARE FLUCTUATING BETWEEN MVFR AND VFR
CONDITIONS AT KFLO. THE COLD FRONT IS EXPECTED TO PUSH ITS WAY TO
THE COAST THROUGH THE DAY AND IS CURRENTLY PASSING BY KCLT AND
APPROACHING KCAE. FOR TODAY THE CONFIDENCE IS LOW FOR IFR CONDITIONS
AND MVFR CONDITIONS ARE POSSIBLE DUE TO CEILINGS WITH RIBBON OF
MOISTURE ALONG AND AHEAD OF THE FRONT. THE FORECAST INCLUDES
VICINITY OF SHOWERS AHEAD OF THE FRONT BUT CURRENTLY PRECIPITATION
IS NOT EXPECTED TO BE WIDESPREAD...SIGNIFICANT AND AN IMPACT TO
AVIATION.

A WIND SHIFT FROM THE SOUTHWEST TO NORTHWEST IS EXPECTED WITH THE
FRONTS PASSAGE. TIMING OF THE WIND SHIFT IS EXPECTED TO BE AT 15 UTC
AT THE INLAND TAF SITES OF KFLO AND KLBT AND 17 UTC AT THE COASTAL
SITES OF KILM...KCRE AND KMYR.


EXTENDED OUTLOOK...VFR SATURDAY. RAIN AND IFR POSSIBLE SUNDAY AND
MONDAY MORNING. VFR TUESDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...SEAS AT THE FRYING PAN SHOALS BUOY HAVE
CLIMBED TO 7 FT THIS MORNING...DUE LARGELY TO AN EXPANSIVE FETCH
OF SOUTH WINDS ALONG THE SOUTHEASTERN U.S. COAST. A DOMINANT WAVE
PERIOD AROUND 7 SECONDS SHOW THE SOURCE REGION FOR THIS WAVE ENERGY
PROBABLY EXISTS BETWEEN NORTH CAROLINA AND GEORGIA/NORTH FLORIDA.
CHANGES ARE ON THE THE WAY HOWEVER AS A COLD FRONT NOW IN THE
CENTRAL CAROLINAS MOVES EAST AND OFF THE COAST THIS AFTERNOON.
SOUTHWEST WINDS WILL SHIFT TO THE NORTH THIS AFTERNOON...THEN TO THE
NORTH-NORTHEAST LATE TONIGHT AS HIGH PRESSURE TO OUR NORTHWEST
BUILDS IN. WE SHOULD GET THROUGH THIS EVENT WITHOUT NEEDING A SMALL
CRAFT ADVISORY...WITH SEAS INSIDE OF 20 MILES REMAINING UNDER 6
FEET. WINDS SHOULD DIMINISH TO 15 KT OR LESS SHORTLY...AND
POST-FRONTAL WINDS SHOULD TOP OUT IN THE 15 KNOT RANGE TONIGHT. WE
WILL MAINTAIN THE EXERCISE CAUTION HEADLINE IN THE FORECAST MAINLY
FOR SEAS THROUGH THIS MORNING ACROSS THE NORTH CAROLINA WATERS.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...NORTHEAST FLOW INITIALLY OF 15-20 KNOTS WILL
MOST LIKELY KEEP SEAS IN A 3-5 FOOT RANGE WARRANTING A SCEC
HEADLINE. WINDS DIMINISH SATURDAY NIGHT INTO SUNDAY AS THE
GRADIENT WEAKENS. FINALLY A DECENT NORTHWEST FLOW DEVELOPS EARLY
MONDAY AS HIGH PRESSURE BUILDS BACK IN. HIGHEST SEAS WITH THIS
FETCH WILL DEVELOP ACROSS THE OUTER WATERS.

LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...HIGH PRESSURE MOVES IN FROM THE TENNESSEE
VALLEY MONDAY AND TUESDAY. WINDS WILL VEER FROM NORTHWEST TO
NORTHEAST AND FINALLY LIGHT AND VARIABLE TUESDAY AS THE HIGH MOVES
DIRECTLY OVERHEAD. ALL OF THIS COULD CHANGE DRAMATICALLY HOWEVER AS
FORECAST MODELS REMAIN FAR APART IN THEIR RESPECTIVE SOLUTIONS. IF
THE FORECAST DOES CHANGE...WIND SPEEDS WILL INCREASE SOMEWHAT AS LOW
PRESSURE INCREASES THE GRADIENT WITH THE PREVIOUSLY MENTIONED AREA
OF HIGH PRESSURE. PROBABLY NOT DYNAMIC ENOUGH TO WARRANT A HEADLINE
HOWEVER.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DRH






AREA FORECAST DISCUSSION

NWS CORPUS CHRISTI TX

 906 AM CST FRI DEC 23 2011

.DISCUSSION...CAA CONTS THIS MORNING AND HAS LEAD TO STRONG
OFFSHORE WINDS ACROSS THE COASTAL WATERS. A SCA FOR THE OFFSHORE
WATERS WAS TO GO INTO EFFECT AT NOON BUT HAVE GONE AHEAD AND PUT
THE SCA INTO EFFECT NOW. AS FOR THE REST OF THE FCST...STILL LOOKS
LIKE CLOUDS WILL BE ON THE INCREASE TODAY ALONG WITH A COASTAL
TROF DVLPG THROUGH TONIGHT IN RESPONSE TO AN APPROACHING MID/UPPER
LEVEL LOW. THEREFORE NO OTHER CHANGES TO THE FCST AT THIS TIME.

&&

.PREV DISCUSSION... /ISSUED 556 AM CST FRI DEC 23 2011/

DISCUSSION...UPDATED FOR 12Z AVIATION DISCUSSION BELOW.

AVIATION...MIX OF VFR/MVFR THROUGH NEXT 24 HRS. LOW CLOUD DECK
PROG TO DEVELOP/EXPAND THIS MRNG. MVFR CIGS XPCTD TO INCREASE TO
VFR MIDDAY/EARLY AFTN THEN GRADUALLY LOWER THROUGH TONIGHT.
OVERRUNNING WX PATTERN TO DEVELOP TONIGHT THRU SAT WITH DZ/RA
POSSIBLE OVERNIGHT AT KLRD WITH -DZ DVLPING VCNTY KCRP/KALI BY
DAYBREAK. MVFR CIGS TONIGHT ALL TERMINALS MAY BRIEFLY BECOME IFR
AT KLRD. BREEZY NNE WINDS TODAY TO STRENGTHEN LATE TONIGHT AS
COASTAL TROUGH DVLPS.

PREV DISCUSSION... /ISSUED 503 AM CST FRI DEC 23 2011/

SHORT TERM (TODAY THROUGH SATURDAY)...MSAS AND LAPS DATA ALONG
WITH SFC OBS INDICATE COLD FRONT HAS PUSHED SOUTH THROUGH ALL OF
CWA WITH SHALLOW COOL/DRY AIRMASS ADVECTING INTO REGION. RUC DATA
AND WATER VAPOR ANALYSIS SHOWS MID LEVEL LOW DIGGING SOUTH ACROSS SE
AZ AND IS PROG TO EVENTUALLY KICK EAST BY LATE TODAY AND THROUGH
SATURDAY AND WILL IMPACT AREA WEATHER. TODAY TO FEATURE LOW CLOUD
DECK DEVELOPING WHICH WILL HELP SUPPRESS WARMING. HAVE GONE
TOWARDS COOLER GUIDANCE FOR MAX TEMPS THO HOW WARM WE GET WILL
DEPEND ON HOW FAST LOW CLOUDS FILL IN. WAA AT H85 TO DEVELOP
TONIGHT AND WITH INCREASE OF MOISTURE INFLUX IN LOWEST HUNDRED MB
AS COASTAL TROUGH DEVELOPS PATCHY -RA/DZ IS EXPECTED TO DEVELOP
ALONG RIO GRANDE THIS EVENING WITH AN INCREASE IN COVERAGE LIKELY
ACROSS BRUSH COUNTRY AND COASTAL PLAINS BY DAYBREAK SATURDAY. ALL
INDICATIONS ARE THAT MOST AREAS SHOULD SEE RAIN AT SOME POINT ON
SATURDAY AS UPPER LEVEL DISTURBANCE KICKS EAST INTO TX AND COASTAL
TROUGH PERSISTS ALONG MID TX COAST. HIGHEST RAINFALL AMOUNTS MAY
OCCUR ACROSS FAR EASTERN BRUSH COUNTRY...COASTAL PLAINS AND NE
ZONES WHERE BEST MOISTURE TRANSPORT PROG TO OCCUR ALONG WITH
APPROACHING UPPER LEVEL JET STREAK. POCKETS OF LOCALLY HEAVY RAIN
ARE NOT OUT OF THE QUESTION. GUIDANCE DIFFERS ON HOW LONG RAINS
WILL PERSIST WITH HI RES ARW...NMM AND CMC KEEPING EQUAL CHANCES
ACROSS THE AREA THROUGH SAT EVENING WHILE ECMWF AND GFS GRADUALLY
END RAINFALL FROM WEST TO EAST BY LATE IN THE DAY. EXPECTING A
GRADUAL SHIFTING OF BACK EDGE OF RAIN FROM WEST TO EAST BY LATE IN
THE DAY SATURDAY AND INTO THE EVENING. CONCERNING TEMPS
TONIGHT...SOME EVAP COOLING SHOULD OCCUR INTO EARLY SAT MORNING
AND HAVE GONE BELOW GUIDANCE FOR MOST LOCATIONS. THICK CLOUD COVER
AND PRECIP SHOULD RESULT IN LITTLE DIURNAL RANGE IN TEMPS ON SAT
AND HAVE GONE WELL BELOW GUIDANCE FOR HIGHS. AS COASTAL TROUGH
DEVELOPS TONIGHT SFC WINDS WILL INCREASE WITH RAW AND GUSTY NE
WINDS TO BE COMMON ACROSS EASTERN THIRD OF CWA LATE TONIGHT
THROUGH SATURDAY.

LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...ON SATURDAY EVENING
COASTAL SFC TROF WILL START TO TRANSITION SLIGHTLY FURTHER OFF THE
COAST WHILE H8 INVERTED TROF WILL REMAIN SITUATED OVER THE COAST
WITH OVERRUNNING PRECIPITATION STARTS TO PUSH GRADUALLY EASTWARD
AS WELL.  THE PRECIPITATION WILL CONTINUE TO TAPER AND MIGRATE
EASTWARD OVER THE MARINE WATERS OVERNIGHT INTO SUNDAY MORNING AS THE
COASTAL TROF CONTINUES TO PUSH INTO THE WESTERN GULF.  THE H5 UPPER
TROF WILL PUSH INTO THE ARKLATEX REGION SUNDAY WITH WINDS BACKING TO
A MORE NORTHWEST FLOW AS A SFC HIGH DIVES INTO THE BIG BEND REGION.
AS A RESULT A MUCH DRIER AND COOL AIRMASS WILL REMAIN ENTRENCHED
ACROSS SOUTH TEXAS ON SUNDAY WITH HIGHS REBOUNDING TO THE MID 50S
ACROSS THE REGION. A SECOND UPPER TROF WILL TRACK ACROSS NORTH TEXAS
MONDAY AS SFC HIGH PRESSURE MOVES OVER SOUTH TEXAS. DRY NORTHERLY
FLOW AND SUBSIDENCE WILL PREVAIL MONDAY WITH TEMPERATURES WARMING
SLIGHTLY WITH HIGHS IN THE UPPER 50S TO NEAR 60 ALONG THE COAST.
OVERNIGHT LOWS MONDAY WILL BE IN THE MID 30S ACROSS THE INTERIOR AND
IN THE LWR 40S ALONG THE IMMEDIATE COAST WITH SOME LOCATIONS ACROSS
THE NORTHERN TIER OF THE CWA REMAINING IN THE 30S TUESDAY MORNING.
SPOTTY MIN TEMPERATURES NEAR OR JUST BELOW FREEZING MONDAY AND
TUESDAY MORNING...PARTICULARLY IN THE LOWER TERRAIN OF LASALLE AND
MCMULLEN COUNTIES SUCH AS CROSS AND FOWLERTON. TEMPS WILL SLOWLY
MODIFY EACH DAY THROUGH THE WORK-WEEK AS A RETURN FLOW GETS
ESTABLISHED BY LATE TUESDAY OR EARLY WEDNESDAY AS THE SFC HIGH
SLIDES EASTWARD INTO THE SE UNITED STATES. HIGHS TEMPERATURES BY THE
END OF THE WEEK WILL BE IN THE 70S AREA WIDE.

70/SCC

MARINE...COLD FRONT HAS MOVED SOUTH THROUGH WATERS THIS MORNING.
NORTH WINDS ARE MEETING SCA CRITERIA ACROSS PORTIONS OF
BAYS/WATERWAYS THIS MORNING BUT THIS SHOULD BE SHORT LIVED.
INCREASE IN WINDS AND SEAS TO COME LATE THIS AFTERNOON AND THROUGH
HOLIDAY WEEKEND AS COASTAL TROUGH DEVELOPS. SMALL CRAFT ADVISORIES
IN EFFECT FOR OFFSHORE WATERS STARTING AT NOON AS WINDS INCREASE
TO AROUND 20 KNOTS AND FOR NEAR SHORE WATERS STARTING LATE
TONIGHT. ADVISORIES TO CONTINUE THROUGH SATURDAY AS SEAS BECOME
ROUGH AND WINDS REMAIN STRONG. ADVISORIES ARE LIKELY TO BE
EXPANDED FOR BAYS AND WATERWAYS FOR THIS WEEKEND IN LATER FORECAST
PACKAGES. RAIN POSSIBLY HEAVY AT TIMES LIKELY ON SATURDAY AND INTO
SATURDAY NIGHT.

&&

.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI    61  49  50  40  56  /  10  40  80  60  10
VICTORIA          58  45  49  38  56  /  10  20  80  70  10
LAREDO            60  45  48  40  57  /  10  60  80  20  10
ALICE             61  47  49  39  56  /  10  50  80  40  10
ROCKPORT          60  49  52  43  57  /  10  30  80  70  10
COTULLA           57  43  47  36  55  /  10  50  80  20  10
KINGSVILLE        61  49  50  40  57  /  10  50  80  50  10
NAVY CORPUS       62  52  54  43  58  /  10  40  80  70  10

&&

.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 PM CST
     SATURDAY FOR THE FOLLOWING ZONES: 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 6 PM CST SATURDAY 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.

&&

$$

TE/81...SHORT TERM
WC/87...LONG TERM






AREA FORECAST DISCUSSION...UPDATED

NWS CORPUS CHRISTI TX

 556 AM CST FRI DEC 23 2011

.DISCUSSION...UPDATED FOR 12Z AVIATION DISCUSSION BELOW.

&&

.AVIATION...MIX OF VFR/MVFR THROUGH NEXT 24 HRS. LOW CLOUD DECK
PROG TO DEVELOP/EXPAND THIS MRNG. MVFR CIGS XPCTD TO INCREASE TO
VFR MIDDAY/EARLY AFTN THEN GRADUALLY LOWER THROUGH TONIGHT.
OVERRUNNING WX PATTERN TO DEVELOP TONIGHT THRU SAT WITH DZ/RA
POSSIBLE OVERNIGHT AT KLRD WITH -DZ DVLPING VCNTY KCRP/KALI BY
DAYBREAK. MVFR CIGS TONIGHT ALL TERMINALS MAY BRIEFLY BECOME IFR
AT KLRD. BREEZY NNE WINDS TODAY TO STRENGTHEN LATE TONIGHT AS
COASTAL TROUGH DVLPS.

&&

.PREV DISCUSSION... /ISSUED 503 AM CST FRI DEC 23 2011/

SHORT TERM (TODAY THROUGH SATURDAY)...MSAS AND LAPS DATA ALONG
WITH SFC OBS INDICATE COLD FRONT HAS PUSHED SOUTH THROUGH ALL OF
CWA WITH SHALLOW COOL/DRY AIRMASS ADVECTING INTO REGION. RUC DATA
AND WATER VAPOR ANALYSIS SHOWS MID LEVEL LOW DIGGING SOUTH ACROSS SE
AZ AND IS PROG TO EVENTUALLY KICK EAST BY LATE TODAY AND THROUGH
SATURDAY AND WILL IMPACT AREA WEATHER. TODAY TO FEATURE LOW CLOUD
DECK DEVELOPING WHICH WILL HELP SUPPRESS WARMING. HAVE GONE
TOWARDS COOLER GUIDANCE FOR MAX TEMPS THO HOW WARM WE GET WILL
DEPEND ON HOW FAST LOW CLOUDS FILL IN. WAA AT H85 TO DEVELOP
TONIGHT AND WITH INCREASE OF MOISTURE INFLUX IN LOWEST HUNDRED MB
AS COASTAL TROUGH DEVELOPS PATCHY -RA/DZ IS EXPECTED TO DEVELOP
ALONG RIO GRANDE THIS EVENING WITH AN INCREASE IN COVERAGE LIKELY
ACROSS BRUSH COUNTRY AND COASTAL PLAINS BY DAYBREAK SATURDAY. ALL
INDICATIONS ARE THAT MOST AREAS SHOULD SEE RAIN AT SOME POINT ON
SATURDAY AS UPPER LEVEL DISTURBANCE KICKS EAST INTO TX AND COASTAL
TROUGH PERSISTS ALONG MID TX COAST. HIGHEST RAINFALL AMOUNTS MAY
OCCUR ACROSS FAR EASTERN BRUSH COUNTRY...COASTAL PLAINS AND NE
ZONES WHERE BEST MOISTURE TRANSPORT PROG TO OCCUR ALONG WITH
APPROACHING UPPER LEVEL JET STREAK. POCKETS OF LOCALLY HEAVY RAIN
ARE NOT OUT OF THE QUESTION. GUIDANCE DIFFERS ON HOW LONG RAINS
WILL PERSIST WITH HI RES ARW...NMM AND CMC KEEPING EQUAL CHANCES
ACROSS THE AREA THROUGH SAT EVENING WHILE ECMWF AND GFS GRADUALLY
END RAINFALL FROM WEST TO EAST BY LATE IN THE DAY. EXPECTING A
GRADUAL SHIFTING OF BACK EDGE OF RAIN FROM WEST TO EAST BY LATE IN
THE DAY SATURDAY AND INTO THE EVENING. CONCERNING TEMPS
TONIGHT...SOME EVAP COOLING SHOULD OCCUR INTO EARLY SAT MORNING
AND HAVE GONE BELOW GUIDANCE FOR MOST LOCATIONS. THICK CLOUD COVER
AND PRECIP SHOULD RESULT IN LITTLE DIURNAL RANGE IN TEMPS ON SAT
AND HAVE GONE WELL BELOW GUIDANCE FOR HIGHS. AS COASTAL TROUGH
DEVELOPS TONIGHT SFC WINDS WILL INCREASE WITH RAW AND GUSTY NE
WINDS TO BE COMMON ACROSS EASTERN THIRD OF CWA LATE TONIGHT
THROUGH SATURDAY.

LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...ON SATURDAY EVENING
COASTAL SFC TROF WILL START TO TRANSITION SLIGHTLY FURTHER OFF THE
COAST WHILE H8 INVERTED TROF WILL REMAIN SITUATED OVER THE COAST
WITH OVERRUNNING PRECIPITATION STARTS TO PUSH GRADUALLY EASTWARD
AS WELL.  THE PRECIPITATION WILL CONTINUE TO TAPER AND MIGRATE
EASTWARD OVER THE MARINE WATERS OVERNIGHT INTO SUNDAY MORNING AS THE
COASTAL TROF CONTINUES TO PUSH INTO THE WESTERN GULF.  THE H5 UPPER
TROF WILL PUSH INTO THE ARKLATEX REGION SUNDAY WITH WINDS BACKING TO
A MORE NORTHWEST FLOW AS A SFC HIGH DIVES INTO THE BIG BEND REGION.
AS A RESULT A MUCH DRIER AND COOL AIRMASS WILL REMAIN ENTRENCHED
ACROSS SOUTH TEXAS ON SUNDAY WITH HIGHS REBOUNDING TO THE MID 50S
ACROSS THE REGION. A SECOND UPPER TROF WILL TRACK ACROSS NORTH TEXAS
MONDAY AS SFC HIGH PRESSURE MOVES OVER SOUTH TEXAS. DRY NORTHERLY
FLOW AND SUBSIDENCE WILL PREVAIL MONDAY WITH TEMPERATURES WARMING
SLIGHTLY WITH HIGHS IN THE UPPER 50S TO NEAR 60 ALONG THE COAST.
OVERNIGHT LOWS MONDAY WILL BE IN THE MID 30S ACROSS THE INTERIOR AND
IN THE LWR 40S ALONG THE IMMEDIATE COAST WITH SOME LOCATIONS ACROSS
THE NORTHERN TIER OF THE CWA REMAINING IN THE 30S TUESDAY MORNING.
SPOTTY MIN TEMPERATURES NEAR OR JUST BELOW FREEZING MONDAY AND
TUESDAY MORNING...PARTICULARLY IN THE LOWER TERRAIN OF LASALLE AND
MCMULLEN COUNTIES SUCH AS CROSS AND FOWLERTON. TEMPS WILL SLOWLY
MODIFY EACH DAY THROUGH THE WORK-WEEK AS A RETURN FLOW GETS
ESTABLISHED BY LATE TUESDAY OR EARLY WEDNESDAY AS THE SFC HIGH
SLIDES EASTWARD INTO THE SE UNITED STATES. HIGHS TEMPERATURES BY THE
END OF THE WEEK WILL BE IN THE 70S AREA WIDE.

70/SCC

MARINE...COLD FRONT HAS MOVED SOUTH THROUGH WATERS THIS MORNING.
NORTH WINDS ARE MEETING SCA CRITERIA ACROSS PORTIONS OF
BAYS/WATERWAYS THIS MORNING BUT THIS SHOULD BE SHORT LIVED.
INCREASE IN WINDS AND SEAS TO COME LATE THIS AFTERNOON AND THROUGH
HOLIDAY WEEKEND AS COASTAL TROUGH DEVELOPS. SMALL CRAFT ADVISORIES
IN EFFECT FOR OFFSHORE WATERS STARTING AT NOON AS WINDS INCREASE
TO AROUND 20 KNOTS AND FOR NEAR SHORE WATERS STARTING LATE
TONIGHT. ADVISORIES TO CONTINUE THROUGH SATURDAY AS SEAS BECOME
ROUGH AND WINDS REMAIN STRONG. ADVISORIES ARE LIKELY TO BE
EXPANDED FOR BAYS AND WATERWAYS FOR THIS WEEKEND IN LATER FORECAST
PACKAGES. RAIN POSSIBLY HEAVY AT TIMES LIKELY ON SATURDAY AND INTO
SATURDAY NIGHT.

&&

.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI    61  49  50  40  56  /  10  40  80  60  10
VICTORIA          58  45  49  38  56  /  10  20  80  70  10
LAREDO            60  45  48  40  57  /  10  60  80  20  10
ALICE             61  47  49  39  56  /  10  50  80  40  10
ROCKPORT          60  49  52  43  57  /  10  30  80  70  10
COTULLA           57  43  47  36  55  /  10  50  80  20  10
KINGSVILLE        61  49  50  40  57  /  10  50  80  50  10
NAVY CORPUS       62  52  54  43  58  /  10  40  80  70  10

&&

.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 PM CST
     SATURDAY FOR THE FOLLOWING ZONES: 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 FROM NOON TODAY TO 6 PM CST SATURDAY 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.

&&

$$

AVIATION...HART/79





AREA FORECAST DISCUSSION

NWS CORPUS CHRISTI TX

 503 AM CST FRI DEC 23 2011

.SHORT TERM (TODAY THROUGH SATURDAY)...MSAS AND LAPS DATA ALONG
WITH SFC OBS INDICATE COLD FRONT HAS PUSHED SOUTH THROUGH ALL OF
CWA WITH SHALLOW COOL/DRY AIRMASS ADVECTING INTO REGION. RUC DATA
AND WATER VAPOR ANALYSIS SHOWS MID LEVEL LOW DIGGING SOUTH ACROSS SE
AZ AND IS PROG TO EVENTUALLY KICK EAST BY LATE TODAY AND THROUGH
SATURDAY AND WILL IMPACT AREA WEATHER. TODAY TO FEATURE LOW CLOUD
DECK DEVELOPING WHICH WILL HELP SUPPRESS WARMING. HAVE GONE
TOWARDS COOLER GUIDANCE FOR MAX TEMPS THO HOW WARM WE GET WILL
DEPEND ON HOW FAST LOW CLOUDS FILL IN. WAA AT H85 TO DEVELOP
TONIGHT AND WITH INCREASE OF MOISTURE INFLUX IN LOWEST HUNDRED MB
AS COASTAL TROUGH DEVELOPS PATCHY -RA/DZ IS EXPECTED TO DEVELOP
ALONG RIO GRANDE THIS EVENING WITH AN INCREASE IN COVERAGE LIKELY
ACROSS BRUSH COUNTRY AND COASTAL PLAINS BY DAYBREAK SATURDAY. ALL
INDICATIONS ARE THAT MOST AREAS SHOULD SEE RAIN AT SOME POINT ON
SATURDAY AS UPPER LEVEL DISTURBANCE KICKS EAST INTO TX AND COASTAL
TROUGH PERSISTS ALONG MID TX COAST. HIGHEST RAINFALL AMOUNTS MAY
OCCUR ACROSS FAR EASTERN BRUSH COUNTRY...COASTAL PLAINS AND NE
ZONES WHERE BEST MOISTURE TRANSPORT PROG TO OCCUR ALONG WITH
APPROACHING UPPER LEVEL JET STREAK. POCKETS OF LOCALLY HEAVY RAIN
ARE NOT OUT OF THE QUESTION. GUIDANCE DIFFERS ON HOW LONG RAINS
WILL PERSIST WITH HI RES ARW...NMM AND CMC KEEPING EQUAL CHANCES
ACROSS THE AREA THROUGH SAT EVENING WHILE ECMWF AND GFS GRADUALLY
END RAINFALL FROM WEST TO EAST BY LATE IN THE DAY. EXPECTING A
GRADUAL SHIFTING OF BACK EDGE OF RAIN FROM WEST TO EAST BY LATE IN
THE DAY SATURDAY AND INTO THE EVENING. CONCERNING TEMPS
TONIGHT...SOME EVAP COOLING SHOULD OCCUR INTO EARLY SAT MORNING
AND HAVE GONE BELOW GUIDANCE FOR MOST LOCATIONS. THICK CLOUD COVER
AND PRECIP SHOULD RESULT IN LITTLE DIURNAL RANGE IN TEMPS ON SAT
AND HAVE GONE WELL BELOW GUIDANCE FOR HIGHS. AS COASTAL TROUGH
DEVELOPS TONIGHT SFC WINDS WILL INCREASE WITH RAW AND GUSTY NE
WINDS TO BE COMMON ACROSS EASTERN THIRD OF CWA LATE TONIGHT
THROUGH SATURDAY.
&&

.LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...ON SATURDAY EVENING
COASTAL SFC TROF WILL START TO TRANSITION SLIGHTLY FURTHER OFF THE
COAST WHILE H8 INVERTED TROF WILL REMAIN SITUATED OVER THE COAST
WITH OVERRUNNING PRECIPITATION STARTS TO PUSH GRADUALLY EASTWARD
AS WELL.  THE PRECIPITATION WILL CONTINUE TO TAPER AND MIGRATE
EASTWARD OVER THE MARINE WATERS OVERNIGHT INTO SUNDAY MORNING AS THE
COASTAL TROF CONTINUES TO PUSH INTO THE WESTERN GULF.  THE H5 UPPER
TROF WILL PUSH INTO THE ARKLATEX REGION SUNDAY WITH WINDS BACKING TO
A MORE NORTHWEST FLOW AS A SFC HIGH DIVES INTO THE BIG BEND REGION.
AS A RESULT A MUCH DRIER AND COOL AIRMASS WILL REMAIN ENTRENCHED
ACROSS SOUTH TEXAS ON SUNDAY WITH HIGHS REBOUNDING TO THE MID 50S
ACROSS THE REGION. A SECOND UPPER TROF WILL TRACK ACROSS NORTH TEXAS
MONDAY AS SFC HIGH PRESSURE MOVES OVER SOUTH TEXAS. DRY NORTHERLY
FLOW AND SUBSIDENCE WILL PREVAIL MONDAY WITH TEMPERATURES WARMING
SLIGHTLY WITH HIGHS IN THE UPPER 50S TO NEAR 60 ALONG THE COAST.
OVERNIGHT LOWS MONDAY WILL BE IN THE MID 30S ACROSS THE INTERIOR AND
IN THE LWR 40S ALONG THE IMMEDIATE COAST WITH SOME LOCATIONS ACROSS
THE NORTHERN TIER OF THE CWA REMAINING IN THE 30S TUESDAY MORNING.
SPOTTY MIN TEMPERATURES NEAR OR JUST BELOW FREEZING MONDAY AND
TUESDAY MORNING...PARTICULARLY IN THE LOWER TERRAIN OF LASALLE AND
MCMULLEN COUNTIES SUCH AS CROSS AND FOWLERTON. TEMPS WILL SLOWLY
MODIFY EACH DAY THROUGH THE WORK-WEEK AS A RETURN FLOW GETS
ESTABLISHED BY LATE TUESDAY OR EARLY WEDNESDAY AS THE SFC HIGH
SLIDES EASTWARD INTO THE SE UNITED STATES. HIGHS TEMPERATURES BY THE
END OF THE WEEK WILL BE IN THE 70S AREA WIDE.

70/SCC
&&

.MARINE...COLD FRONT HAS MOVED SOUTH THROUGH WATERS THIS MORNING.
NORTH WINDS ARE MEETING SCA CRITERIA ACROSS PORTIONS OF
BAYS/WATERWAYS THIS MORNING BUT THIS SHOULD BE SHORT LIVED.
INCREASE IN WINDS AND SEAS TO COME LATE THIS AFTERNOON AND THROUGH
HOLIDAY WEEKEND AS COASTAL TROUGH DEVELOPS. SMALL CRAFT ADVISORIES
IN EFFECT FOR OFFSHORE WATERS STARTING AT NOON AS WINDS INCREASE
TO AROUND 20 KNOTS AND FOR NEAR SHORE WATERS STARTING LATE
TONIGHT. ADVISORIES TO CONTINUE THROUGH SATURDAY AS SEAS BECOME
ROUGH AND WINDS REMAIN STRONG. ADVISORIES ARE LIKELY TO BE
EXPANDED FOR BAYS AND WATERWAYS FOR THIS WEEKEND IN LATER FORECAST
PACKAGES. RAIN POSSIBLY HEAVY AT TIMES LIKELY ON SATURDAY AND INTO
SATURDAY NIGHT.
&&

.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI    61  49  50  40  56  /  10  40  80  60  10
VICTORIA          58  45  49  38  56  /  10  20  80  70  10
LAREDO            60  45  48  40  57  /  10  60  80  20  10
ALICE             61  47  49  39  56  /  10  50  80  40  10
ROCKPORT          60  49  52  43  57  /  10  30  80  70  10
COTULLA           57  43  47  36  55  /  10  50  80  20  10
KINGSVILLE        61  49  50  40  57  /  10  50  80  50  10
NAVY CORPUS       62  52  54  43  58  /  10  40  80  70  10

&&

.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 PM CST
     SATURDAY FOR THE FOLLOWING ZONES: 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 FROM NOON TODAY TO 6 PM CST SATURDAY 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.

&&

$$

RH/79...SHORT TERM
SC/70...LONG TERM






AREA FORECAST DISCUSSION

NWS QUAD CITIES IA IL

 312 PM CST FRI DEC 23 2011

.SYNOPSIS...
A VIGOROUS CLIPPER SYSTEM WAS SEEN ON WATER VAPOR IMAGERY SWEEPING
SOUTHEAST ACROSS MN AND WI THIS AFTERNOON. AT 18Z...ASSOCIATED
SURFACE LOW PRESSURE WAS CENTERED IN SW ONTARIO JUST NORTH OF MN
WITH A TROUGH EXTENDING S-SW ACROSS MN INTO CENTRAL NEB. AHEAD OF
THIS TROUGH...WIDESPREAD LIGHT SNOW AND BRIEF LOCALIZED MODERATE
SNOW WAS FALLING ACROSS SE MN INTO MUCH OF WI. MID AND HIGH LEVEL
CLOUD COVER PRECEDING THE SYSTEM HAS SPREAD SOUTH-SE TO COVER THE
NORTHERN HALF OF THE FORECAST AREA...WHILE STRATUS TO THE SOUTH
THAT PERSISTED OVERNIGHT HAS BEEN DRAWN NORTHWARD IN THE LOW LEVEL
SW FLOW TO COVER THE FAR SOUTHEAST PART OF THE FORECAST AREA. THE
CLOUD COVER...AND SLIGHTLY HIGHER LOW LEVEL MOISTURE LEVELS...HAVE
HELD TEMPERATURES A FEW DEGREES COOLER THAN EXPECTED TODAY WITH
MANY AREAS STRUGGLING TO REACH 32 AS OF 2 PM.

&&

.SHORT TERM...TONIGHT AND SATURDAY...
THE MAIN FOCUS IS ON THE NEAR TERM POTENTIAL FOR LIGHT SNOW. 12Z
FORECAST MODELS HAVE GENERALLY BEEN TOO WEAK WITH THE SURFACE
PRESSURE FIELDS...TOO LOW ON LOW LEVEL MOISTURE LEVELS...AND ALSO
AND A BIT TOO FAR NORTH AND TOO WEAK WITH THE UPPER FORCING SO FAR
TODAY. FOLLOWING THE LATEST RUC DEPICTION OF A LOBE OF MID LEVEL
VORTICITY ROTATING AROUND THE BASE OF THE MAIN SHORTWAVE...THE TRACK
OF UPPER LEVEL DIVERGENCE IN THE LEFT EXIT REGION OF A 100 PLUS
KT JET DIVING SOUTH OUT OF MANITOBA...THERE IS SUPPORT THAT LIFT
AND SATURATION MAY PULL FLURRIES OR EVEN LIGHT SNOW FURTHER SOUTH
AND SOUTHWEST THAN PREVIOUSLY EXPECTED. AN IMPRESSIVE AXIS OF
WIDESPREAD 4 MB PRESSURE FALLS ON MSAS SWEEPING INTO EASTERN IA
AND A MOST RECENT 5 MB BULLSEYE CENTERED NEAR VINTON...FURTHER
SUPPORTS THIS POSSIBILITY. HOWEVER...WITH CLOUD BASES STILL WELL
ABOVE 9000 FT OVER MOST OF IA AND A STRONG SW LOW LEVEL FLOW
ADVECTING DRY AIR INTO THIS FAST MOVING SYSTEM...SUFFICIENT
SATURATION WILL BE DIFFICULT OVER MOST OF THE FORECAST AREA. HAVE
ADDED A POTENTIAL FOR FLURRIES ACROSS THE NORTHEAST FOR LATE
AFTERNOON INTO EVENING...WITH LOW CHANCES FOR A DUSTING OF
ACCUMULATION ALONG AND NORTH OF THE HIGHWAY 20 CORRIDOR IN IL.

ONCE THIS SYSTEM PASSES EARLY THIS EVENING...DRIER AIR AND WEAK
SUBSIDENCE SHOULD ALLOW THE WIDESPREAD CLEARING OVER THE PLAINS TO
SPREAD EASTWARD OVER THE FORECAST AREA. HAVE KEPT LOWS IN A RANGE
FROM THE TEENS NORTH TO LOWER 20S SOUTH...BUT WILL HAVE TO WATCH
TRENDS CLOSELY AS TEMPERATURES COULD POSSIBLY PLUNGE LOWER AS WINDS
BECOME LIGHT WESTERLY LATE TONIGHT UNDER MOSTLY CLEAR SKIES.
SATURDAY...TEMPERATURES SHOULD MODERATE AS WARM ADVECTION ALOFT
COMMENCES WHILE A LARGELY DRY AIRMASS FAVORS MOSTLY SUNNY SKIES.
FORECAST SOUNDINGS DEPICT A LOW LEVEL INVERSION HOLDING STRONG WITH
GENERALLY LIGHT SW WINDS AND HAVE THUS HELD HIGHS CLOSE TO GUIDANCE
VALUES IN THE 30S OVER MOST OF THE AREA. ..SHEETS..

.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
AN OVERALL TREND OF WARMER AND LIKELY DRIER THAN NORMAL SHOULD BE
SEEN THROUGH THE END OF THE MONTH.

A COLD FRONTAL PASSAGE WILL OCCUR SATURDAY NIGHT/EARLY SUNDAY AS
ANOTHER SYSTEM PASSES WELL NORTH OF THE AREA. CONDENSATION PRESSURE
DEFICITS IN THE LOW AND MID LEVELS ARE QUITE HIGH. THUS A DRY FROPA
SHOULD BE SEEN WITH ONLY AN INCREASE IN CLOUDS. BRISK CONDITIONS
WILL BE SEEN ON SUNDAY WITH RESPECTABLE CAA BEHIND THE FRONT.

HIGH PRESSURE WILL QUICKLY MOVE THROUGH THE REGION SUNDAY NIGHT
KEEPING QUIET AND DRY CONDITIONS ACROSS THE AREA. ATTENTION THEN
TURNS TO THE STORM SYSTEM EARLY NEXT WEEK.

THE OVERALL LONGWAVE PATTERN IS DE-AMPLIFYING AND WILL ELIMINATE THE
SPLIT FLOW OVER THE WESTERN CONUS EARLY NEXT WEEK. A STRONG UPPER
LEVEL SYSTEM NEAR 40N/160W WILL MAKE LANDFALL ON THE WA/OR COAST
SUNDAY AND WILL BE THE KEY TO WHAT HAPPENS WITH THE CUT OFF LOW IN
THE SOUTHERN STREAM MONDAY INTO MONDAY NIGHT. THE OVERALL TREND WITH
THE MODELS HAS BEEN TO SLOW DOWN THE EJECTION OF THE CUT OFF LOW.

THUS THERE ARE TWO POSSIBLE OUTCOMES. THE FIRST IS A PARTIAL PHASING
WITH THE NORTHERN STREAM ENERGY WHICH WOULD PULL THE SOUTHERN CUT
OFF LOW FURTHER NORTH. THE OTHER POSSIBILITY IS A CONTINUED SLOWING
OF THE CUT OFF LOW WHICH WOULD RESULT IN NO PHASING OF THE NORTHERN
AND SOUTHERN STREAMS. IF THE SECOND SCENARIO OCCURS...THE SOUTHERN
STREAM SYSTEM WOULD PASS SOUTH OF THE AREA RESULTING IN DRY
CONDITIONS.

SINCE THE MODELS HAVE BECOME SLOWER WITH THE SOUTHERN CUT OFF
LOW...MONDAY WILL BE DRY WITH AN INCREASE IN CLOUDS THROUGH THE DAY.
PRECIPITATION MAY BE NOT FAR AWAY FROM THE SOUTHERN CWFA BY SUNSET
MONDAY.

MONDAY NIGHT ON...
RIGHT NOW THE MODEL CONSENSUS IS FOR A PARTIAL PHASING OF THE
NORTHERN AND SOUTHERN STREAMS. SUCH A SCENARIO WILL BRING A THREAT
OF PRECIPITATION TO MUCH OF THE CWFA MONDAY NIGHT. A RAIN/SNOW MIX
LOOKS TO BE THE MOST LIKELY WITH A POSSIBLE CHANGE OVER TO ALL SNOW
JUST PRIOR TO SUNRISE TUESDAY. ANY SNOWFALL WOULD BE ONE HALF INCH
OR LESS.

MODEL CONSENSUS GIVES QUIET AND DRY CONDITIONS TUESDAY/TUES NIGHT AS
HIGH PRESSURE QUICKLY MOVES THROUGH THE AREA.

BY MID WEEK A NEAR ZONAL OR VERY LOW AMPLITUDE FLOW WILL EXIST
ACROSS THE CONUS AND PACIFIC. THERE ARE DIFFERENCES BETWEEN THE
MODELS BUT THE POTENTIAL EXISTS FOR A NEAR DAILY OCCURRENCE OF
CLIPPER OR HYBRID CLIPPER SYSTEMS FROM WEDNESDAY THROUGH FRIDAY. THE
MODEL DIFFERENCES WITH TIMING AND SMOOTHING ARE CAUSING POPS TO
CANCEL EACH OTHER OUT WHICH PRODUCES A CONSENSUS FCST OF MAINLY DRY
CONDITIONS FOR WEDNESDAY THROUGH FRIDAY.

INTERNALLY...THE MODELS SHOW SOME RESPECTABLE FORCING AND A
LOWERING OF CONDENSATION PRESSURE DEFICITS WITH EACH SYSTEM. THUS
THERE MAY BE A POTENTIAL FOR PRECIPITATION WEDNESDAY THROUGH FRIDAY.
THE SMOOTHING OF FEATURES MAKES IT DIFFICULT TO ASCERTAIN WHERE
PRECIPITATION MAY OCCUR. AREAS NORTH OF HWY 30 ARE CURRENTLY
DEPICTED AS HAVING THE BETTER FORCING AND LOWER CONDENSATION
PRESSURE DEFICITS WHICH IMPLIES A BETTER CHANCE OF PRECIPITATION.
HOWEVER...ANY PRECIPITATION THAT OCCURS WILL BE LIGHT.

THE PROGNOSTIC CHARTS ARE INDICATING THE LONGWAVE PATTERN WILL BEGIN
TO RE-AMPLIFY IN EARLY JANUARY. A WEAK TO MODERATE LA NINA COMBINED
WITH A NEGATIVE PDO AND SST ANOMALIES WOULD FAVOR A LONGWAVE TROF
NEAR THE EAST COAST.
..08..

&&

.AVIATION...
A FAST MOVING STORM SYSTEM MOVING ACROSS MN...WI INTO THE GREAT
LAKES WAS PRODUCING BRISK SW WINDS AND DENSE MID AND HIGH LEVEL
CLOUD COVER INTO THIS EVENING. ACCUMULATING SNOW AND IFR CONDITIONS
WILL REMAIN NORTHEAST OF FORECAST TERMINALS...BUT THERE IS A
POTENTIAL THAT FLURRIES MAY BRIEFLY AFFECT THE DBQ SITE BETWEEN 21Z
AND 23Z. OTHERWISE...VFR CONDITIONS AND CLEARING SKIES WILL
PREVAIL TONIGHT THROUGH FRIDAY WITH BRISK SW WINDS DIMINISHING TO
LESS THAN 10 KTS AND BECOMING WESTERLY OVERNIGHT. ..SHEETS..

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

$$

SHEETS/08






AREA FORECAST DISCUSSION

NWS GOODLAND KS

 1031 AM MST FRI DEC 23 2011

.UPDATE...
317 AM MST FRI DEC 23 2011

IR AND 11-3.9 SATELLITE IMAGES SHOW PATCHY FOG MOVING ACROSS PARTS
OF CHEYENNE COUNTY COLORADO. LIMON DID HAVE SOME BRIEF REDUCTIONS IN VISIBILITY
DOWN TO A QUARTER...BUT LOOKS LIKE THE FOG IS NOT THAT DENSE OVER
CHEYENNE COUNTY. LATEST VSREF AND HRRR SHOW IT MAY MOVE INTO PARTS
OF WALLACE AND GREELEY COUNTY SO WILL INCLUDE THESE THREE COUNTIES
IN A MENTION OF PATCHY FREEZING FOG. THE FREEZING FOG SHOULD
DISSIPATE BY MID MORNING.

JTL
&&

.SHORT TERM (TODAY-CHRISTMAS DAY)...
227 AM MST FRI DEC 23 2011

RATHER TRANQUIL WEATHER WILL BE IN STORE FOR THE TRI-STATE AREA FOR
THE CHRISTMAS WEEKEND.  AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL
REMAIN OVER THE AREA DURING THE PERIOD.  LATE IN THE PERIOD AN UPPER
LEVEL SHORT WAVE TROUGH WILL MOVE THROUGH THE PERIPHERY OF THE RIDGE.
WITH MOST OF THE JET ENERGY NORTH OF THE AREA AND A DRY ENVIRONMENT
IN PLACE...WILL CONTINUE TO LEAVE CHRISTMAS NIGHT DRY.

HIGH TEMPERATURES WILL BE NORMAL TO ABOVE NORMAL THROUGH THE PERIOD
AS WARMER 850MB AIR IS BROUGHT IN BY THE NORTHWEST WINDS.  LOW
TEMPERATURES WILL BE NEAR NORMAL TO BELOW NORMAL FOR TONIGHT THEN
WARM TO EITHER NEAR NORMAL OR ABOVE NORMAL VALUES FOR THE WEEKEND.
SOME UNCERTAINTY EXISTS REGARDING THE EFFECT THE RECENT SNOWFALL
FROM EARLIER THIS WEEK WILL HAVE ON TEMPERATURES.  GENERAL TREND WAS
TO HAVE COOLER TEMPERATURES OVER THE SOUTHERN AND SOUTHEASTERN AREAS
WHERE THE HIGHEST SNOWFALL AMOUNTS WERE REPORTED.

JTL

.LONG TERM (MONDAY-THURSDAY)...
227 AM MST FRI DEC 23 2011

PROGRESSIVE PATTERN WILL BE IN PLACE ACROSS THE CONUS WITH A
SERIES OF FAST MOVING AND WEAK SYSTEMS. THE ONLY ONE THAT APPEARS
TO HAVE EVEN A SLIGHT CHANCE OF BRINGING PRECIPITATION TO THE AREA
WILL BE ON THURSDAY NIGHT...BUT IT WOULD BE VERY LIGHT IF IT
OCCURS AT ALL. DEEP WESTERLY FLOW WILL DOMINATE AND RESULT IN
LIMITED MOISTURE. THERE IS NO COLD AIR IN SIGHT AND TEMPERATURES
WILL BE ABOVE NORMAL THE ENTIRE PERIOD.

024
&&

.AVIATION...
1029 AM MST FRI DEC 23 2011

VFR CONDITIONS EXPECTED FROM TODAY THROUGH TONIGHT AND SATURDAY
AT KMCK AND KGLD. HIGH PRESSURE WILL REMAIN IN PLACE WITH LIGHT
WEST WINDS TURNING SLIGHTLY MORE NORTHWEST.

LOCKHART
&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS WAKEFIELD VA

 432 PM EST FRI DEC 23 2011

.SYNOPSIS...
HIGH PRESSURE BUILDS IN FROM THE WEST TONIGHT THROUGH THE HOLIDAY
WEEKEND. A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY NIGHT WITH
HIGH PRESSURE BUILDING BACK IN FOR MONDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
COLDER AIR CONTINUES TO FILTER INTO THE REGION. TEMPERATURES WILL
DROP QUICKLY AFTER SUNSET EVEN WITH A FEW CLOUDS STILL LINGERING.
SATELLITE IMAGERY SHOWS AN UPPER LOW MOVING ACROSS WISCONSIN AND
APPEARS NOW ON SATELLITE TO BE MOVING MOSTLY EAST WHICH MATCHES
WELL WITH BOTH THE GFS AND NAM WHICH KEEP IT MOVING ACROSS NEW
ENGLAND TONIGHT. SOME STRATOCU HAS BEEN ABLE TO SPILL OVER THE
MOUNTAINS THIS AFTERNOON AND MAY LINGER IN THE NORTH FOR WHILE
THIS EVENING AS THE UPPER LOW PUSHES BY TO THE NORTH. ALSO A
STRONG JET STREAK IS ACROSS THE AREA TONIGHT WHICH MIGHT HELP TO
KEEP A FEW UPPER LEVEL CLOUDS AROUND. ALL AREAS SHOULD BE CLEAR BY
MORNING. FOLLOWED MOS GUIDE FOR THE MINS TONIGHT. THINK WITH SOME
WINDS AND A FEW CLOUDS TEMPERATURES WILL STAY UP A LITTLE.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
HIGH PRESSURE CENTERED IN THE MIDWEST WILL RIDGE EAST ACROSS THE
AREA SATURDAY THROUGH SUNDAY. UPPER LEVEL FLOW FEATURES A STRONG
WEST TO EAST JET ACROSS THE AREA AND THIS IS KEEPING MOISTURE TO
THE SOUTH AND MOST OF THE COLD AIR IS BEING HELD FARTHER NORTH.
MODELS SHOW ANOTHER FAST MOVING UPPER SYSTEM MOVING SOUTHEAST
ACROSS THE AREA ON CHRISTMAS DAY AND THIS WILL PUSH A COLD FRONT
THROUGH. DO NOT SEE MUCH IN THE WAY OF MOISTURE WITH THIS SYSTEM
WITH MAINLY DRY WEST FLOW AHEAD OF THE SYSTEM. MIGHT SEE A PARTLY
CLOUDY DAY IN SOME AREAS ON CHRISTMAS DAY. THEN BACK TO SUNNY
WEATHER AGAIN FOR MONDAY. TEMPERATURES WILL BE CLOSE TO NORMAL
THROUGH THE PERIOD WITH HIGHS NEAR 50 AND LOWS IN THE UPPER 20S TO
MID 30S. THIS IS CLOSE TO MOS GUIDE WHICH LOOKS TO HAVE A GOOD
HANDLE ON THE TEMPERATURES. THE COOLEST DAYS WILL BE SATURDAY AND
MONDAY WITH CHRISTMAS A FEW DEGREES WARMER.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE STRONGLY POSITIVE NAO PATTERN OF THE PAST MONTH WILL CONTINUE
INTO NEXT WEEK. THIS WILL KEEP ARCTIC AIR LOCKED WELL NORTH IN
CANADA (ABOVE 60N LATITUDE) AND CONTINUE TO ALLOW PACIFIC AIR TO
STREAM ACROSS THE COUNTRY WITH AN OCCASIONAL MODIFIED POLAR AIRMASS
CLIPPING THE EXTREME NORTHERN TIER OF THE US. THIS WILL MAINTAIN
ABOVE NORMAL TEMPERATURES ACROSS THE MID ATLANTIC ALTHOUGH WITHIN +1
STDEV OF THE MEAN. A SOUTHERN STREAM SYSTEM IS EXPECTED TO CROSS THE
TENNESSEE VALLEY MONDAY NIGHT AND MOVE THROUGH THE MID ATLANTIC
TUESDAY. MODEL AGREEMENT HAS INCREASED WITH THIS SYSTEM WITH THE GFS
AND ECMWF DEMONSTRATING DECENT TIMING AGREEMENT WITH THE CMC SLIGHTLY
SLOWER. HIGH PRESSURE RETURNS FROM THE SOUTHWEST BEHIND THIS SYSTEM
WITH PLEASANT CONDITIONS FOLLOWING FOR THE MIDDLE AND END OF THE
WEEK.

&&

.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
THE COLD FRONT HAS PUSHED WELL TO THE SOUTH OF THE TAF SITES.
STRATUS ASSOCIATED WITH THE FRONT IS GIVING WAY TO SCATTERED CUMULUS
WHICH WILL THEN CLEAR AS THE SUN SETS. A WEAK SHORT WAVE MOVING OVER
THE MID ATLANTIC STATES DURING THE EARLY MORNING HOURS COULD PRODUCE
A FEW MID LEVEL CLOUDS BUT LEFT THE TAFS CLEAR. GUSTY WINDS FROM
THIS MORNING HAVE DIMINISHED AND SHOULD BECOME LIGHT BY THIS
EVENING. CLEAR SKIES AND LIGHT WINDS ARE EXPECTED SATURDAY AS
SURFACE HIGH PRESSURE SETTLES OVER THE AREA.

OUTLOOK...VFR/DRY WEATHER EXPECTED THROUGH MONDAY. THERE WILL BE A
CHANCE FOR RAIN AND LOWER AVIATION CONDITIONS TUESDAY.

&&

.MARINE...
A SECONDARY SURGE IS AFFECTING THE BAY LATE THIS AFTERNOON. MODEL
GUIDANCE HAS STRUGGLED WITH THIS SURGE...ALTHOUGH THE LATEST RUC AND
HRRR RUNS INDICATE SPEED COULD LINGER AROUND LOW END SCA CRITERIA
FOR THE BAY AND SOUND INTO THIS EVENING. THEREFORE...AN SCA FLAG HAS
BEEN RAISED THROUGH 10 PM. CONDITIONS OVER THE OCEAN SHOULD LARGELY
REMAIN SUB-SCA THROUGH THE EVENING.

HIGH PRESSURE BUILDS INTO THE REGION OVERNIGHT BRINGING BENIGN
CONDITIONS THROUGH CHRISTMAS MORNING. A STRONG LOW PRESSURE SYSTEM
DIGS ACROSS THE NORTHERN GREAT LAKES AND NORTHERN NEW ENGLAND
CHRISTMAS DAY INTO CHRISTMAS NIGHT. THIS PUSHES A COLD FRONT THROUGH
THE NORTHEAST AND NORTHERN MID ATLANTIC FOLLOWED BY A STRONG NW CAA
SURGE LATE CHRISTMAS NIGHT INTO MONDAY MORNING. SOLID SCA CONDITIONS
APPEAR LIKELY DURING THIS TIME.

HIGH PRESSURE BRIEFLY RETURNS MONDAY BEFORE QUICKLY MOVING OFF THE
COAST AS ANOTHER LOW PRESSURE SYSTEM APPROACHES FROM THE SOUTHWEST
MONDAY NIGHT AND TUESDAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     ANZ630>634.

&&

$$
SYNOPSIS...JAB
NEAR TERM...JAB
SHORT TERM...JAB
LONG TERM...AJZ
AVIATION...LSA
MARINE...AJZ





AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 1246 PM EST FRI DEC 23 2011

UPDATED AVIATION DISCUSSION FOR 18Z TAFS

.UPDATE...SYSTEM SNOW IS PRESSING INTO FAR WESTERN UPR MI AND WILL
CONTINUE TO SPREAD ACROSS ALL OF CWA THROUGH THE AFTN. REGIONAL
RADAR AND SFC OBS INDICATE HEAVIEST SNOW IN CORRIDOR FM NORTHEAST MN
NEAR KDLH INTO NW WI...STILL WEST AS KASX. THIS AREA IS JUST TO
RIGHT OF SHORTWAVE TRACKING ACROSS CNTRL MN. EXPECT MODERATE SNOW AT
TIMES INTO THE AFTN OVR SW CWA. COULD SEE 1-2 INCHES IN THAT AREA.
LESS THAN 1 INCH WILL PROBABLY COVER IT ELSEWHERE. GOING FCST IN
PRETTY GOOD SHAPE WITH REGARD TO SYSTEM SNOW.

SOUTH/SOUTHWEST WINDS FLOWING UP LK MICHIGAN WITH H85 TEMPS AROUND
-10C LEADS TO DELTA T/S UP TO 16C. FCST SOUNDINGS IN THIS AREA
DEPICT LARGE SCALE LIFT OCCURRING WITHIN GOOD PORTION OF DENDRITIC
GROWTH ZONE. THIS INCREASING OVER-WATER INSTABILITY COMBINED WITH
FORCING FM SYSTEM MOVING THROUGH LATE AFTN/EVENING SHOULD LEAD TO
GOOD SETUP FOR LAKE ENHANCED SNOW. HIGHER RESOLUTION MODELS DIFFERING
ON WHERE TO FOCUS SHARPEST LOW-LEVEL CONVERGENCE AND HEAVIER SNOW OVR
EASTERN CWA. GIVEN 925-850MB WINDS IN THE 210-230 RANGE AND SFC
CONVERGENCE FCST TO INCREASE INTO SOUTHERN PORTION OF LUCE COUNTY...OPTED
TO ISSUE A WINTER WEATHER ADVY FOR SNOW LATE TODAY AND THIS EVENING
FOR LUCE COUNTY. SFC LOW IS A BIT STRONGER THAT MODELS HAVE SHOWN
THUS FAR SO IF ANYTHING BLYR WINDS MAY BACK MORE THAN IS SHOWN.
THOUGHT POTENTIAL FOR ADVY LEVEL SNOWS WAS TOO HIGH TO NOT HAVE ANY
HEADLINE OUT SO HAVE POSTED ONE FM 21Z TODAY THROUGH 05Z TONIGHT.
TOTAL SNOW ACCUMS 3-5 INCHES EXPECTED...PROBABLY HEAVIEST JUST SOUTH
AND EAST OF KERY...AND INTO MACKINAC COUNTY WHERE GAYLORD MI NWS
OFFICE ALREADY HAS ADVY OUT THROUGH TONIGHT.

COULD SEE TRAVEL BECOMING QUITE DIFFICULT SOMEWHERE IN THIS AREA
THIS EVENING DUE TO SNOW COVERED ROADS AND POOR VISIBILITY. HAZARD
IS FURTHER HEIGHTENED SINCE IT IS OCCURRING ON FRIDAY EVENING
PRECEEDING THE CHRISTMAS HOLIDAY WEEKEND.
&&

.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED MID/UPPER LEVEL TROUGHING FROM
NE CANADA INTO THE CNTRL CONUS RESULTING IN NW FLOW FROM CNTRL
CANADA INTO THE GREAT LAKES. A PROMINENT UPSTREAM SHORTWAVE TROUGH
WAS LOCATED NEAR LAKE WINNIPEG. AT THE SFC...SRLY WINDS WERE
INCREASING OVER MN AND WRN LAKE SUPERIOR AHEAD OF LOW PRES OVER THE
SE CORNER OF MANITOBA. THE AREA OF WAA LIGHT SNOW HAD MOVED INTO NRN
MN WITH VSBYS DOWN TO 1-3SM. LINGERING SCT LIGHT LAKE EFFECT SNOW
SHOWERS OVER ERN LAKE SUPERIOR WERE QUICKLY DIMINISHING AND STARING
TO MOVE OFFSHORE AS THE RIDGE AXIS MOVES THROUGH AND WINDS BACK TO
THE SW.
&&

.DISCUSSION...

TODAY AND TONIGHT...EXPECT THE AREA OF SNOW TO MAKE STEADY PROGRESS
TO THE SE AS THE MANTITOBA CLIPPER SHORTWAVE AND LOW APPROACH THE
AREA. THE BAND OF MODERATE TO STRONG NET 280K ISENTROPIC ASCENT AND
700-300 MB QVECTOR CONV WILL SUPPORT GOING HIGHER END POPS ACROSS THE
CWA...MAINLY BTWN 18Z-24Z. HOWEVER...MOISTURE WILL BE LIMITED WITH
ONLY 1.0 1O 1.5 G/KG AVAILABLE IN THE 700-750 MB LAYER AND PWAT
VALUES OF AROUND 0.25 INCH. SO...ACCUMULATIONS SHOULD REMAIN
GENERALLY LIGHT...AT OR BELOW AN INCH. DOWNSLOPE SRLY FLOW MAY ALSO
REDUCE AMOUNTS NEAR LAKE SUPERIOR IN NORTH CENTRAL UPPER MI. 850 MB
TEMPS AROUND -10C SUPPORT POTENTIAL FOR SOME LAKE ENHANCED SNOW NEAR
LAKE MICHIGAN. WITH ONLY A BRIEF PERIOD OF DEEPER MOISTURE/LIFT
MOVING THROUGH ANY ADDITIONAL AMOUNTS WILL ALSO BE SMALL. THE BEST
CHANCE FOR MORE SIGNIFICANT SNOW AMOUNTS WILL BE EAST OF
MANISTIQUE...GIVEN PREDOMINANT 220-230 CBL FLOW LATE THIS AFTERNOON
AND EVENING.

WITH ONLY MODERATE INSTABILITY...THE SNOW WILL DIMINISH QUICKLY OVER
FROM WEST TO EAST IN THE EVENING AS THE SHORTWAVE MOVES THROUGH AND
SUBSIDENCE TAKES OVER. CLOUDS MAY ALSO DIMINISH LATE AS 925-850 MB
WEST FLOW DRY ADVECTION MOVES IN.

SATURDAY...DRY WEATHER IS EXPECTED AS THE FORCING AND ISENTROPIC
NEXT WEAKER CLIPPER SHRTWV IS EXPECTED TO REMAIN NORTH OF THE
CWA...PER GFS/ECMWF/GEM. WAA WILL BRING A REBOUND IN TEMPS BACK INTO
THE UPPER 20S AND LOWER 30S.

SATURDAY NIGHT INTO SUNDAY...A SLIGHTLY STRONGER SHRTWV WILL MOVE
THROUGH THE WESTERN GREAT LAKES LATE SAT NIGHT INTO EARLY SUN.
THERE WAS GREATER UNCERTAINTY WITH POTENTIAL FOR LIGHT SYNOPTIC
LIGHT SNOW. THE GFS WAS FARTHER SOUTH WITH THIS FEATURE COMAPRED TO
THE ECMWF/GEM. WITH LITTLE MOISTURE AVBL...CHANCE POPS WERE CONFINED
TO LOCATIONS FAVORED BY WNW FLOW WHERE SOME LAKE ENHANCEMENT MAY
OCCUR WITH 850 MB TEMPS AROUND -10C.

MONDAY THROUGH THURSDAY...MID LEVEL RIDGING BUILD INTO THE AREA WITH
STRGER SW FLOW MON...BOOSTING TEMPS WELL ABOVE NORMAL...INTO THE MID
TO UPPER 30S. THE MILD PATTERN CONTINUES THROUGH MUCH OF THE WEEK
WITH ADDITIONAL CLIPPER SYSTEMS MOVING THROUGH. UNCERTAINTY IS
LARGER WITH STRENGTH OF CAA IN THE WAKE OF ANY SYSTEM. THE 00Z
GFS/GEM AND MAJORITY OF GFS ENS SUGGESTED THAT COLD AIR BY TUE INTO
TUE NIGHT WOULD REMAIN ONLY NEAR -10C WHILE THE 00Z ECMWF FCST H8
TEMPS DOWN TO -15C WHICH WOULD BRING GREATER CHANCE FOR SIGNFICANT
LES.
&&

.AVIATION /FOR THE 18Z TAF ISSUANCE/...

A CLIPPER SYSTEM DROPPING SE ACROSS UPPER MICHIGAN WILL SPREAD SNOW
ACROSS THE AREA FROM WEST TO EAST THROUGH EARLY EVENING. HAVE
CONTINUED ALT LANDING MINS FOR ALL SITES DURING THE PEAK SNOW THIS
AFTN. AS THE SYSTEM EXITS...EXPECT BORDERLINE IFR CIGS TO CONTINUE
BEFORE DIMINISHING OVERNIGHT. MODELS CONTINUE TO FCST LOW STRATUS
LATE TONIGHT...BUT BASED ON UPSTREAM CONDITIONS WITH CLEARING SKIES
IN DAKOTAS AND SOUTHERN SASKATCHEWAN AND LACK OF ONSHORE FLOW AT
ANY OF THE TAF SITES...THIS SEEMS OVERDONE. CONTINUED TO SHOW SLIGHT
POSSIBILITY WITH FCST OF SCT LOW CLOUDS. &&

.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...

WITH MODELS COMING TO A CONSENSUS ON LOW TRACK/INTENSITY ACROSS LAKE
SUPERIOR TODAY...HAVE ADJUSTED WINDS DOWN A TOUCH AND ONLY THINK
THERE WILL BE A PERIOD /LATE MORNING THROUGH THE AFTN/ OF SW GUSTS
UP TO 30KTS AHEAD OF THE LOW. WINDS SHOULD DIMINISH BELOW 20KTS
TONIGHT AS THE LOW DISSIPATES WHEN MOVING INTO THE LOWER GREAT
LAKES. SW WINDS WILL ONCE AGAIN BE ON THE INCREASE SAT AHEAD OF THE
NEXT TROUGH TO AFFECT LK SUPERIOR. THIS STRONGER TROUGH WILL PRODUCE
WINDS UP TO 30KTS SAT INTO SUN...AS WINDS GRADUALLY SHIFT TO THE NW
BY SUN WITH THE TROUGH PUSHING EAST. THERE COULD BE A FEW ISOLATED
GALE FORCE GUSTS TO 35KTS DURING THAT PERIOD. AFTER A BRIEF REPRIVE
ON SUN NIGHT...THE NEXT TROUGH WILL AFFECT LK SUPERIOR MON INTO MON
NIGHT. WITH THIS TROUGH EVEN STRONGER...APPEARS TO BE A GOOD CHANCE
OF SEEING SW GALES TO 35KTS OVER MUCH OF LAKE SUPERIOR MON
AFTN/NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO MIDNIGHT EST
     TONIGHT FOR MIZ007.

LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$


UPDATE...JLA
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...JLA
MARINE...SRF








AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 1133 AM EST FRI DEC 23 2011

.UPDATE...SYSTEM SNOW IS PRESSING INTO FAR WESTERN UPR MI AND WILL
CONTINUE TO SPREAD ACROSS ALL OF CWA THROUGH THE AFTN. REGIONAL
RADAR AND SFC OBS INDICATE HEAVIEST SNOW IN CORRIDOR FM NORTHEAST MN
NEAR KDLH INTO NW WI...STILL WEST AS KASX. THIS AREA IS JUST TO
RIGHT OF SHORTWAVE TRACKING ACROSS CNTRL MN. EXPECT MODERATE SNOW AT
TIMES INTO THE AFTN OVR SW CWA. COULD SEE 1-2 INCHES IN THAT AREA.
LESS THAN 1 INCH WILL PROBABLY COVER IT ELSEWHERE. GOING FCST IN
PRETTY GOOD SHAPE WITH REGARD TO SYSTEM SNOW.

SOUTH/SOUTHWEST WINDS FLOWING UP LK MICHIGAN WITH H85 TEMPS AROUND
-10C LEADS TO DELTA T/S UP TO 16C. FCST SOUNDINGS IN THIS AREA
DEPICT LARGE SCALE LIFT OCCURRING WITHIN GOOD PORTION OF DENDRITIC
GROWTH ZONE. THIS INCREASING OVER-WATER INSTABILITY COMBINED WITH
FORCING FM SYSTEM MOVING THROUGH LATE AFTN/EVENING SHOULD LEAD TO
GOOD SETUP FOR LAKE ENHANCED SNOW. HIGHER RESOLUTION MODELS DIFFERING
ON WHERE TO FOCUS SHARPEST LOW-LEVEL CONVERGENCE AND HEAVIER SNOW OVR
EASTERN CWA. GIVEN 925-850MB WINDS IN THE 210-230 RANGE AND SFC
CONVERGENCE FCST TO INCREASE INTO SOUTHERN PORTION OF LUCE COUNTY...OPTED
TO ISSUE A WINTER WEATHER ADVY FOR SNOW LATE TODAY AND THIS EVENING
FOR LUCE COUNTY. SFC LOW IS A BIT STRONGER THAT MODELS HAVE SHOWN
THUS FAR SO IF ANYTHING BLYR WINDS MAY BACK MORE THAN IS SHOWN.
THOUGHT POTENTIAL FOR ADVY LEVEL SNOWS WAS TOO HIGH TO NOT HAVE ANY
HEADLINE OUT SO HAVE POSTED ONE FM 21Z TODAY THROUGH 05Z TONIGHT.
TOTAL SNOW ACCUMS 3-5 INCHES EXPECTED...PROBABLY HEAVIEST JUST SOUTH
AND EAST OF KERY...AND INTO MACKINAC COUNTY WHERE GAYLORD MI NWS
OFFICE ALREADY HAS ADVY OUT THROUGH TONIGHT.

COULD SEE TRAVEL BECOMING QUITE DIFFICULT SOMEWHERE IN THIS AREA
THIS EVENING DUE TO SNOW COVERED ROADS AND POOR VISIBILITY. HAZARD
IS FURTHER HEIGHTENED SINCE IT IS OCCURRING ON FRIDAY EVENING
PRECEEDING THE CHRISTMAS HOLIDAY WEEKEND.

&&

PREV DISCUSSION...ISSUED AT 631 AM EST FRI DEC 23 2011...

.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED MID/UPPER LEVEL TROUGHING FROM
NE CANADA INTO THE CNTRL CONUS RESULTING IN NW FLOW FROM CNTRL
CANADA INTO THE GREAT LAKES. A PROMINENT UPSTREAM SHORTWAVE TROUGH
WAS LOCATED NEAR LAKE WINNIPEG. AT THE SFC...SRLY WINDS WERE
INCREASING OVER MN AND WRN LAKE SUPERIOR AHEAD OF LOW PRES OVER THE
SE CORNER OF MANITOBA. THE AREA OF WAA LIGHT SNOW HAD MOVED INTO NRN
MN WITH VSBYS DOWN TO 1-3SM. LINGERING SCT LIGHT LAKE EFFECT SNOW
SHOWERS OVER ERN LAKE SUPERIOR WERE QUICKLY DIMINISHING AND STARING
TO MOVE OFFSHORE AS THE RIDGE AXIS MOVES THROUGH AND WINDS BACK TO
THE SW.
&&

.DISCUSSION...

TODAY AND TONIGHT...EXPECT THE AREA OF SNOW TO MAKE STEADY PROGRESS
TO THE SE AS THE MANTITOBA CLIPPER SHORTWAVE AND LOW APPROACH THE
AREA. THE BAND OF MODERATE TO STRONG NET 280K ISENTROPIC ASCENT AND
700-300 MB QVECTOR CONV WILL SUPPORT GOING HIGHER END POPS ACROSS THE
CWA...MAINLY BTWN 18Z-24Z. HOWEVER...MOISTURE WILL BE LIMITED WITH
ONLY 1.0 1O 1.5 G/KG AVAILABLE IN THE 700-750 MB LAYER AND PWAT
VALUES OF AROUND 0.25 INCH. SO...ACCUMULATIONS SHOULD REMAIN
GENERALLY LIGHT...AT OR BELOW AN INCH. DOWNSLOPE SRLY FLOW MAY ALSO
REDUCE AMOUNTS NEAR LAKE SUPERIOR IN NORTH CENTRAL UPPER MI. 850 MB
TEMPS AROUND -10C SUPPORT POTENTIAL FOR SOME LAKE ENHANCED SNOW NEAR
LAKE MICHIGAN. WITH ONLY A BRIEF PERIOD OF DEEPER MOISTURE/LIFT
MOVING THROUGH ANY ADDITIONAL AMOUNTS WILL ALSO BE SMALL. THE BEST
CHANCE FOR MORE SIGNIFICANT SNOW AMOUNTS WILL BE EAST OF
MANISTIQUE...GIVEN PREDOMINANT 220-230 CBL FLOW LATE THIS AFTERNOON
AND EVENING.

WITH ONLY MODERATE INSTABILITY...THE SNOW WILL DIMINISH QUICKLY OVER
FROM WEST TO EAST IN THE EVENING AS THE SHORTWAVE MOVES THROUGH AND
SUBSIDENCE TAKES OVER. CLOUDS MAY ALSO DIMINISH LATE AS 925-850 MB
WEST FLOW DRY ADVECTION MOVES IN.

SATURDAY...DRY WEATHER IS EXPECTED AS THE FORCING AND ISENTROPIC
NEXT WEAKER CLIPPER SHRTWV IS EXPECTED TO REMAIN NORTH OF THE
CWA...PER GFS/ECMWF/GEM. WAA WILL BRING A REBOUND IN TEMPS BACK INTO
THE UPPER 20S AND LOWER 30S.

SATURDAY NIGHT INTO SUNDAY...A SLIGHTLY STRONGER SHRTWV WILL MOVE
THROUGH THE WESTERN GREAT LAKES LATE SAT NIGHT INTO EARLY SUN.
THERE WAS GREATER UNCERTAINTY WITH POTENTIAL FOR LIGHT SYNOPTIC
LIGHT SNOW. THE GFS WAS FARTHER SOUTH WITH THIS FEATURE COMAPRED TO
THE ECMWF/GEM. WITH LITTLE MOISTURE AVBL...CHANCE POPS WERE CONFINED
TO LOCATIONS FAVORED BY WNW FLOW WHERE SOME LAKE ENHANCEMENT MAY
OCCUR WITH 850 MB TEMPS AROUND -10C.

MONDAY THROUGH THURSDAY...MID LEVEL RIDGING BUILD INTO THE AREA WITH
STRGER SW FLOW MON...BOOSTING TEMPS WELL ABOVE NORMAL...INTO THE MID
TO UPPER 30S. THE MILD PATTERN CONTINUES THROUGH MUCH OF THE WEEK
WITH ADDITIONAL CLIPPER SYSTEMS MOVING THROUGH. UNCERTAINTY IS
LARGER WITH STRENGTH OF CAA IN THE WAKE OF ANY SYSTEM. THE 00Z
GFS/GEM AND MAJORITY OF GFS ENS SUGGESTED THAT COLD AIR BY TUE INTO
TUE NIGHT WOULD REMAIN ONLY NEAR -10C WHILE THE 00Z ECMWF FCST H8
TEMPS DOWN TO -15C WHICH WOULD BRING GREATER CHANCE FOR SIGNFICANT
LES.
&&

.AVIATION /FOR THE 12Z TAF ISSUANCE/...

A CLIPPER SYSTEM DROPPING SE ACROSS UPPER MICHIGAN WILL SPREAD SNOW
ACROSS THE AREA FROM WEST TO EAST LATE THIS MORNING THROUGH EARLY
EVENING. HAVE CONTINUED ALT LANDING MINS FOR ALL SITES DURING THE
PEAK SNOW IN THE AFTN HRS. AS THE SYSTEM EXITS...EXPECT BORDERLINE
IFR CIGS TO CONTINUE BEFORE DIMINISHING OVERNIGHT. MODELS HINTING AT
LOW CLOUDS THROUGH A GOOD PORTION OF THE NIGHT AND WOULD HAVE LIKED
TO HAVE SEEN A LITTLE DEEPER MOISTURE TO GO WITH LOW CIGS AND SOME
VSBY REDUCTION AFTER 06Z.
&&

.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...

WITH MODELS COMING TO A CONSENSUS ON LOW TRACK/INTENSITY ACROSS LAKE
SUPERIOR TODAY...HAVE ADJUSTED WINDS DOWN A TOUCH AND ONLY THINK
THERE WILL BE A PERIOD /LATE MORNING THROUGH THE AFTN/ OF SW GUSTS
UP TO 30KTS AHEAD OF THE LOW. WINDS SHOULD DIMINISH BELOW 20KTS
TONIGHT AS THE LOW DISSIPATES WHEN MOVING INTO THE LOWER GREAT
LAKES. SW WINDS WILL ONCE AGAIN BE ON THE INCREASE SAT AHEAD OF THE
NEXT TROUGH TO AFFECT LK SUPERIOR. THIS STRONGER TROUGH WILL PRODUCE
WINDS UP TO 30KTS SAT INTO SUN...AS WINDS GRADUALLY SHIFT TO THE NW
BY SUN WITH THE TROUGH PUSHING EAST. THERE COULD BE A FEW ISOLATED
GALE FORCE GUSTS TO 35KTS DURING THAT PERIOD. AFTER A BRIEF REPRIVE
ON SUN NIGHT...THE NEXT TROUGH WILL AFFECT LK SUPERIOR MON INTO MON
NIGHT. WITH THIS TROUGH EVEN STRONGER...APPEARS TO BE A GOOD CHANCE
OF SEEING SW GALES TO 35KTS OVER MUCH OF LAKE SUPERIOR MON
AFTN/NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO MIDNIGHT EST
     TONIGHT FOR MIZ007.

LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

UPDATE...JLA
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...SRF
MARINE...SRF






AREA FORECAST DISCUSSION

NWS CORPUS CHRISTI TX

 1133 AM CST FRI DEC 23 2011

.DISCUSSION...SEE AVIATION SECTION BELOW.

&&

.AVIATION...CLOUDS CAN BE SEEN VIA VSBY SATELLITE SPREADING AND
THICKENING ACROSS S TX. AS A RESULT...VFR/MVFR CIGS WILL LOWER
THRU THE AFTERNOON AND INTO TONIGHT. PATCHY DZ IS EXPECTED TO DVLP
OVERNIGHT AS ISENTROPIC UPGLIDE DVLPS...MAINLY ACROSS THE W CWA
THEN SHIFTING E THROUGH THE PERIOD. THIS WILL LEAD TO MVFR CIGS
AND OCCASIONALLY MVFR VSBY`S AS WELL. IFR CONDITIONS WILL BE POSSIBLE
AT TIMES ON SATURDAY AS MOISTURE CONTS TO DEEPEN ACROSS THE AREA.

&&

.PREV DISCUSSION... /ISSUED 906 AM CST FRI DEC 23 2011/

DISCUSSION...CAA CONTS THIS MORNING AND HAS LEAD TO STRONG
OFFSHORE WINDS ACROSS THE COASTAL WATERS. A SCA FOR THE OFFSHORE
WATERS WAS TO GO INTO EFFECT AT NOON BUT HAVE GONE AHEAD AND PUT
THE SCA INTO EFFECT NOW. AS FOR THE REST OF THE FCST...STILL LOOKS
LIKE CLOUDS WILL BE ON THE INCREASE TODAY ALONG WITH A COASTAL
TROF DVLPG THROUGH TONIGHT IN RESPONSE TO AN APPROACHING MID/UPPER
LEVEL LOW. THEREFORE NO OTHER CHANGES TO THE FCST AT THIS TIME.

PREV DISCUSSION... /ISSUED 556 AM CST FRI DEC 23 2011/

DISCUSSION...UPDATED FOR 12Z AVIATION DISCUSSION BELOW.

AVIATION...MIX OF VFR/MVFR THROUGH NEXT 24 HRS. LOW CLOUD DECK
PROG TO DEVELOP/EXPAND THIS MRNG. MVFR CIGS XPCTD TO INCREASE TO
VFR MIDDAY/EARLY AFTN THEN GRADUALLY LOWER THROUGH TONIGHT.
OVERRUNNING WX PATTERN TO DEVELOP TONIGHT THRU SAT WITH DZ/RA
POSSIBLE OVERNIGHT AT KLRD WITH -DZ DVLPING VCNTY KCRP/KALI BY
DAYBREAK. MVFR CIGS TONIGHT ALL TERMINALS MAY BRIEFLY BECOME IFR
AT KLRD. BREEZY NNE WINDS TODAY TO STRENGTHEN LATE TONIGHT AS
COASTAL TROUGH DVLPS.

PREV DISCUSSION... /ISSUED 503 AM CST FRI DEC 23 2011/

SHORT TERM (TODAY THROUGH SATURDAY)...MSAS AND LAPS DATA ALONG
WITH SFC OBS INDICATE COLD FRONT HAS PUSHED SOUTH THROUGH ALL OF
CWA WITH SHALLOW COOL/DRY AIRMASS ADVECTING INTO REGION. RUC DATA
AND WATER VAPOR ANALYSIS SHOWS MID LEVEL LOW DIGGING SOUTH ACROSS SE
AZ AND IS PROG TO EVENTUALLY KICK EAST BY LATE TODAY AND THROUGH
SATURDAY AND WILL IMPACT AREA WEATHER. TODAY TO FEATURE LOW CLOUD
DECK DEVELOPING WHICH WILL HELP SUPPRESS WARMING. HAVE GONE
TOWARDS COOLER GUIDANCE FOR MAX TEMPS THO HOW WARM WE GET WILL
DEPEND ON HOW FAST LOW CLOUDS FILL IN. WAA AT H85 TO DEVELOP
TONIGHT AND WITH INCREASE OF MOISTURE INFLUX IN LOWEST HUNDRED MB
AS COASTAL TROUGH DEVELOPS PATCHY -RA/DZ IS EXPECTED TO DEVELOP
ALONG RIO GRANDE THIS EVENING WITH AN INCREASE IN COVERAGE LIKELY
ACROSS BRUSH COUNTRY AND COASTAL PLAINS BY DAYBREAK SATURDAY. ALL
INDICATIONS ARE THAT MOST AREAS SHOULD SEE RAIN AT SOME POINT ON
SATURDAY AS UPPER LEVEL DISTURBANCE KICKS EAST INTO TX AND COASTAL
TROUGH PERSISTS ALONG MID TX COAST. HIGHEST RAINFALL AMOUNTS MAY
OCCUR ACROSS FAR EASTERN BRUSH COUNTRY...COASTAL PLAINS AND NE
ZONES WHERE BEST MOISTURE TRANSPORT PROG TO OCCUR ALONG WITH
APPROACHING UPPER LEVEL JET STREAK. POCKETS OF LOCALLY HEAVY RAIN
ARE NOT OUT OF THE QUESTION. GUIDANCE DIFFERS ON HOW LONG RAINS
WILL PERSIST WITH HI RES ARW...NMM AND CMC KEEPING EQUAL CHANCES
ACROSS THE AREA THROUGH SAT EVENING WHILE ECMWF AND GFS GRADUALLY
END RAINFALL FROM WEST TO EAST BY LATE IN THE DAY. EXPECTING A
GRADUAL SHIFTING OF BACK EDGE OF RAIN FROM WEST TO EAST BY LATE IN
THE DAY SATURDAY AND INTO THE EVENING. CONCERNING TEMPS
TONIGHT...SOME EVAP COOLING SHOULD OCCUR INTO EARLY SAT MORNING
AND HAVE GONE BELOW GUIDANCE FOR MOST LOCATIONS. THICK CLOUD COVER
AND PRECIP SHOULD RESULT IN LITTLE DIURNAL RANGE IN TEMPS ON SAT
AND HAVE GONE WELL BELOW GUIDANCE FOR HIGHS. AS COASTAL TROUGH
DEVELOPS TONIGHT SFC WINDS WILL INCREASE WITH RAW AND GUSTY NE
WINDS TO BE COMMON ACROSS EASTERN THIRD OF CWA LATE TONIGHT
THROUGH SATURDAY.

LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...ON SATURDAY EVENING
COASTAL SFC TROF WILL START TO TRANSITION SLIGHTLY FURTHER OFF THE
COAST WHILE H8 INVERTED TROF WILL REMAIN SITUATED OVER THE COAST
WITH OVERRUNNING PRECIPITATION STARTS TO PUSH GRADUALLY EASTWARD
AS WELL.  THE PRECIPITATION WILL CONTINUE TO TAPER AND MIGRATE
EASTWARD OVER THE MARINE WATERS OVERNIGHT INTO SUNDAY MORNING AS THE
COASTAL TROF CONTINUES TO PUSH INTO THE WESTERN GULF.  THE H5 UPPER
TROF WILL PUSH INTO THE ARKLATEX REGION SUNDAY WITH WINDS BACKING TO
A MORE NORTHWEST FLOW AS A SFC HIGH DIVES INTO THE BIG BEND REGION.
AS A RESULT A MUCH DRIER AND COOL AIRMASS WILL REMAIN ENTRENCHED
ACROSS SOUTH TEXAS ON SUNDAY WITH HIGHS REBOUNDING TO THE MID 50S
ACROSS THE REGION. A SECOND UPPER TROF WILL TRACK ACROSS NORTH TEXAS
MONDAY AS SFC HIGH PRESSURE MOVES OVER SOUTH TEXAS. DRY NORTHERLY
FLOW AND SUBSIDENCE WILL PREVAIL MONDAY WITH TEMPERATURES WARMING
SLIGHTLY WITH HIGHS IN THE UPPER 50S TO NEAR 60 ALONG THE COAST.
OVERNIGHT LOWS MONDAY WILL BE IN THE MID 30S ACROSS THE INTERIOR AND
IN THE LWR 40S ALONG THE IMMEDIATE COAST WITH SOME LOCATIONS ACROSS
THE NORTHERN TIER OF THE CWA REMAINING IN THE 30S TUESDAY MORNING.
SPOTTY MIN TEMPERATURES NEAR OR JUST BELOW FREEZING MONDAY AND
TUESDAY MORNING...PARTICULARLY IN THE LOWER TERRAIN OF LASALLE AND
MCMULLEN COUNTIES SUCH AS CROSS AND FOWLERTON. TEMPS WILL SLOWLY
MODIFY EACH DAY THROUGH THE WORK-WEEK AS A RETURN FLOW GETS
ESTABLISHED BY LATE TUESDAY OR EARLY WEDNESDAY AS THE SFC HIGH
SLIDES EASTWARD INTO THE SE UNITED STATES. HIGHS TEMPERATURES BY THE
END OF THE WEEK WILL BE IN THE 70S AREA WIDE.

70/SCC

MARINE...COLD FRONT HAS MOVED SOUTH THROUGH WATERS THIS MORNING.
NORTH WINDS ARE MEETING SCA CRITERIA ACROSS PORTIONS OF
BAYS/WATERWAYS THIS MORNING BUT THIS SHOULD BE SHORT LIVED.
INCREASE IN WINDS AND SEAS TO COME LATE THIS AFTERNOON AND THROUGH
HOLIDAY WEEKEND AS COASTAL TROUGH DEVELOPS. SMALL CRAFT ADVISORIES
IN EFFECT FOR OFFSHORE WATERS STARTING AT NOON AS WINDS INCREASE
TO AROUND 20 KNOTS AND FOR NEAR SHORE WATERS STARTING LATE
TONIGHT. ADVISORIES TO CONTINUE THROUGH SATURDAY AS SEAS BECOME
ROUGH AND WINDS REMAIN STRONG. ADVISORIES ARE LIKELY TO BE
EXPANDED FOR BAYS AND WATERWAYS FOR THIS WEEKEND IN LATER FORECAST
PACKAGES. RAIN POSSIBLY HEAVY AT TIMES LIKELY ON SATURDAY AND INTO
SATURDAY NIGHT.

&&

.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI    61  49  50  40  56  /  10  40  80  60  10
VICTORIA          58  45  49  38  56  /  10  20  80  70  10
LAREDO            60  45  48  40  57  /  10  60  80  20  10
ALICE             61  47  49  39  56  /  10  50  80  40  10
ROCKPORT          60  49  52  43  57  /  10  30  80  70  10
COTULLA           57  43  47  36  55  /  10  50  80  20  10
KINGSVILLE        61  49  50  40  57  /  10  50  80  50  10
NAVY CORPUS       62  52  54  43  58  /  10  40  80  70  10

&&

.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 PM CST
     SATURDAY FOR THE FOLLOWING ZONES: 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 6 PM CST SATURDAY 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.

&&

$$

TE/81...SHORT TERM/AVIATION
WC/87...LONG TERM