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000
FXUS61 KLWX 220855
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
355 AM EST MON DEC 22 2014

.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC COAST
TODAY INTO TUESDAY. STRONGER LOW PRESSURE WILL PUSH NORTH ALONG
THE APPALACHIANS ON WEDNESDAY...SENDING A COLD FRONT EASTWARD
WEDNESDAY NIGHT. BREEZY CONDITIONS WILL FOLLOW THE FRONT ON
THURSDAY...THEN HIGH PRESSURE WILL BUILD BACK INTO THE REGION TO
CLOSE OUT THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
CHALLENGING FORECAST EARLY THIS MORNING. CWA IS DRY ATTM...BUT RAIN
HAS ALREADY PUSHED NORTHWARD INTO SOUTHERN VIRGINIA AT 08Z AND WILL
CONTINUE TO SPREAD NORTHWARD THROUGH THE EARLY MORNING HOURS AS LOW
PRESSURE DEVELOPS OFF THE SOUTHEAST COAST. TEMPERATURES ACROSS MUCH
OF THE CWA WERE BELOW FREEZING...AND AS PRECIPITATION MOVES IN FROM
THE SOUTH IT WILL ENCOUNTER THIS SUB-FREEZING AIR.

A PERIOD OF SLEET IS POSSIBLE INITIALLY AS PRECIPITATION BEGINS OVER
THE CWA...BUT PRIMARY P-TYPES TO CONTEND WITH OVER THE NEXT 12-24
HOURS WILL BE FREEZING RAIN OR RAIN DEPENDING ON SURFACE
TEMPERATURES.

CHALLENGES REVOLVE AROUND THE TIMING AND NORTH/NORTHWEST EXTENT OF
PRECIPITATION TODAY AND ALSO HOW QUICKLY TEMPERATURES WILL BE ABLE
TO CLIMB ABOVE FREEZING.

TREND OF THE MODELS HAS BEEN TO SLOW DOWN THE BEGINNING OF PRECIP BY
A LITTLE BIT. HAVE TRENDED THIS WAY...BUT PRECIP SHOULD STILL MAKE
IT INTO THE VIRGINIA FOOTHILLS/PIEDMONT BY SUNRISE. WILL BE
EXPANDING THE FREEZING RAIN ADVISORY A TIER EAST TO THE I-95
CORRIDOR AS LIGHT QPF IS EXPECTED TO FALL WHILE TEMPERATURES ARE
NEAR FREEZING FROM SPOTSYLVANIA UP TO PRINCE WILLIAM COUNTY.
TEMPERATURES IN THESE AREAS SHOULD RISE ABOVE FREEZING BY NOON.

PRECIP IS ALSO LIKELY TO MAKE IT FURTHER NORTH INTO NORTHERN
VIRGINIA DURING THE LATE MORNING/MIDDAY HOURS. SEVERAL SUITES OF
GUIDANCE SUGGEST TEMPERATURES SITTING AROUND THE FREEZING MARK.
THEREFORE HAVE EXPANDED ADVISORY A TIER NORTH AS WELL FOR AREAS OF
FREEZING RAIN WHICH MAY CONTINUE INTO AFTERNOON. HAVE OPTED NOT TO
EXPAND ADVISORY ALL THE WAY TO THE MASON DIXON LINE HOWEVER AS
CONFIDENCE IS QUITE LOW IN PRECIP BEING ABLE TO MAKE IT THAT FAR
NORTH THROUGH MID-AFTERNOON EVEN IF TEMPERATURES ARE COLD ENOUGH TO
SUPPORT FZRA.

FINALLY...EXPIRATION TIME OF EXISTING ADVISORY HAS BEEN EXTENDED
FROM NOON TO 6 PM. AGAIN...SEVERAL SUITES OF GUIDANCE SUGGEST
TEMPERATURES CONTINUING TO BE AT OR JUST BELOW FREEZING FOR AREAS
NEAR/ALONG AND WEST OF THE BLUE RIDGE INTO THE AFTERNOON.

WEAK LOW PRESSURE MOVES UP THE MID-ATLANTIC COAST TONIGHT. HIGHEST
POPS WILL BE CLOSEST TO THE BAY...LOWER IN THE MOUNTAINS. MUCH OF
THE CWA LOOKS WARM ENOUGH FOR PRIMARILY RAIN TONIGHT BUT THERE STILL
MAY BE POCKETS OF SUB-FREEZING AIR WEST OF THE BLUE RIDGE AND ANY
RAIN OR DRIZZLE MAY FREEZE AND ADVISORY MAY NEED TO BE EXTENDED INTO
TONIGHT FOR THOSE AREAS.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
IN THE WAKE OF THE LOW...MID-ATLANTIC REMAINS IN A WEDGE/LIGHT FLOW
REGIME ON TUESDAY THEREFORE CLOUDY SKIES AND THE CHANCE FOR LIGHT
RAIN OR DRIZZLE WILL CONTINUE. TEMPERATURES SHOULD BE WARM ENOUGH
FOR JUST LIQUID PRECIPITATION.

WHILE THERE IS GENERAL SYNOPTIC AGREEMENT IN THE COMPUTER MODELS
THROUGH THE MIDDLE OF THE WEEK...THERE IS STILL QUITE A BIT OF
SPREAD IN THE SMALLER SCALE FEATURES. AMPLIFIED UPPER LEVEL PATTERN
THROUGH THE MIDDLE PORTION OF THE WEEK. TROUGH OVER THE CENTRAL
CONUS WILL LIFT EAST...INDUCING CYCLOGENESIS OVER THE WESTERN GULF
OF MEXICO TUESDAY NIGHT. THIS LOW WILL RIDE UP THE WESTERN SIDE OF
THE APPALACHIANS...REACHING CENTRAL QUEBEC BY THURSDAY.

A STRONG LOW LEVEL JET AHEAD OF THE DEEPENING LOW WILL TRANSPORT
MOISTURE UP THE EASTERN SEABOARD TUESDAY NIGHT...BRINGING INCREASING
CHANCES OF RAIN. TEMPERATURES DROP LITTLE FROM TUESDAYS HIGHS...SO
NO FROZEN PRECIP CONCERNS. WHILE PROBABLY NOT CONTINUOUSLY RAINY
THROUGH THE PERIOD...90-100 POPS ARE WARRANTED...WITH MODERATE RAIN
POSSIBLE AT TIMES. THE NATURE MAY BECOME MORE SHOWERY ON
WEDNESDAY...BUT NOT A COMPELLING REASON TO BREAK THAT OUT AT THIS
TIME. 00Z NAM/MET GUIDANCE MUCH COOLER FOR HIGHS ON
WEDNESDAY...LIKELY DUE TO A MUCH WEAKER SFC LOW THAN THE GLOBAL
MODELS...WHICH ALLOWS THE COLD POOL TO LINGER EAST OF THE MOUNTAINS.
HOWEVER...THE OTHER GUIDANCE OF 60S MAY BE A BIT OVERDONE...EXCEPT
PERHAPS EAST OF I-95. IF THIS OCCURS...WILL ALSO HAVE TO MONITOR FOR
THE POTENTIAL OF STRONG WIND GUSTS IF CONVECTIVE ELEMENTS DEVELOP.

THE COLD FRONT TRAILING THE LOW WILL PUSH THROUGH THURSDAY
NIGHT...BRINGING AN END TO THE PRECIP EXCEPT SOME POSSIBLE UPSLOPE.
HOWEVER WITH THE WARM START...IT WILL TAKE UNTIL LATE IN THE NIGHT
FOR THE TEMPERATURES TO DROP COLD ENOUGH TO SUPPORT ANY SNOW. ALL
TOLD...IMPRESSIVE PWAT VALUES AND A DYNAMIC SYSTEM COULD LEAD TO
STORM TOTAL RAINFALL IN EXCESS OF AN INCH...ESPECIALLY EAST OF THE
MOUNTAINS.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
THURSDAY WILL BE BREEZY BEHIND THE FRONT. ANY UPSLOPE SNOW SHOWERS
SHOULD GRADUALLY COME TO AN END. THERE WILL ONLY BE A GLANCING BLOW
OF CAA...AS HIGH PRESSURE WILL BE BUILDING IN FROM THE SOUTHWEST.
THIS HIGH WILL REMAIN OVER THE SE STATES THROUGH SATURDAY AND
TEMPERATURES ARE EXPECTED TO REMAIN ABOVE NORMAL. THE NEXT CHANCE OF
PRECIP WILL ARRIVE AS THE NEXT TROUGH APPROACHES SATURDAY INTO
SUNDAY. MODEL SOLUTIONS STILL DIFFER QUITE A BIT...SO POPS REMAIN
LOW. THERE WILL BE POTENTIAL FOR TEMPERATURES TO COOL BACK DOWN
BEHIND THIS SYSTEM FOR THE SECOND PART OF THE WEEKEND.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
PRECIP IS EXPECTED TO SPREAD NORTH TODAY. PERIOD OF LIGHT FREEZING
RAIN/SLEET IS MOST LIKELY AT CHO/IAD. MAY BE TOO WARM AT DCA/BWI FOR
FREEZING RAIN...BUT INITIAL PERIOD OF SLEET CAN/T BE RULED OUT
BEFORE TURNING TO RAIN. MODELS HAVE TRENDED A LITTLE SLOWER WITH
ONSET OF PRECIP AND HAVE FOLLOWED SUIT IN TAFS. EXPECT CONDITIONS TO
DROP INTO MVFR THIS AFTERNOON...THEN LIKELY IFR OR LIFR TONIGHT AND
CONTINUING INTO TUESDAY.

BELOW-VFR CIGS WILL LINGER THROUGH WEDNESDAY NIGHT. VSBY COULD DROP
BELOW VFR IN HEAVIER RAIN/SHOWERS AT TIMES FROM TUESDAY NIGHT
THROUGH WEDNESDAY NIGHT. WINDS WILL SHIFT FROM SOUTHERLY TO WESTERLY
WEDNESDAY NIGHT AND COULD GUST ABOVE 25 KT ON THURSDAY. NO
SIGNIFICANT WEATHER EXPECTED AFTER THURSDAY EVENING.

&&

.MARINE...
WEAK LOW PRESSURE MOVES OFF THE MID-ATLANTIC COAST TONIGHT. MARGINAL
SCA EXPECTED ON THE LOWER PORTIONS OF THE WATERS THIS AFTERNOON
OTHERWISE WINDS BELOW SCA THROUGH TUESDAY.

A STRONG LOW PRESSURE SYSTEM WILL MOVE THROUGH THE REGION BETWEEN
TUESDAY AND WEDNESDAY NIGHT...BRING MODERATE RAIN AT TIMES OVER THE
WATERS. A SCA IS LIKELY WEDNESDAY THROUGH THURSDAY...WITH THE
STRONGEST GUSTS EXPECTED ON THURSDAY. WINDS WILL DIMINISH THURSDAY
NIGHT AS HIGH PRESSURE BUILDS IN.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...FREEZING RAIN ADVISORY UNTIL 6 PM EST THIS EVENING FOR VAZ025-
     026-029-036>040-501-503-504-507-508.
     FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR VAZ050>052-055-
     056-502.
     FREEZING RAIN ADVISORY FROM 10 AM THIS MORNING TO 6 PM EST
     THIS EVENING FOR VAZ027-028-030-031-505-506.
WV...FREEZING RAIN ADVISORY UNTIL 6 PM EST THIS EVENING FOR WVZ505-
     506.
     FREEZING RAIN ADVISORY FROM 10 AM THIS MORNING TO 6 PM EST
     THIS EVENING FOR WVZ055.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 6 PM EST THIS
     EVENING FOR ANZ534-537-543.

&&

$$
SYNOPSIS...ADS
NEAR TERM...BPP
SHORT TERM...BPP/ADS
LONG TERM...ADS
AVIATION...ADS/BPP
MARINE...ADS/BPP







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000
FXUS61 KPBZ 220849
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
349 AM EST MON DEC 22 2014

.SYNOPSIS...
MIDWESTERN LOW PRESSURE WILL BRING WARMER TEMPERATURES AND RAIN TO
THE REGION FOR THE FIRST HALF OF THE WEEK. SNOW SHOWER CHANCES WILL
COME WITH THE PASSAGE OF THAT SYSTEMS COLD FRONT ON CHRISTMAS.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLDS ARE EXPD TO INCR TDA IN WRM ADVCTN. A WK SFC LOW IS EXPD TO
ADVN UP THE E COAST INTO THE CAROLINAS TDA...THOUGH RECENT UPR
AIR CHARTS AND MESO DATA INDICATE MOST IF NOT ALL PCPN SHOULD RMN
TO OUR E. WITH COLD AIR DAMMING IN SE FLOW...IF ANY PCPN WERE TO
RCH GARRETT OR TUCKER COUNTIES...A BRF PD OF LGT FRZG RAIN IS
PSBL. CONTD WITH LOW CHC POPS IN THESE AREAS. HIGHS SHOULD AVG A
LTL ABV THE SEASONAL LVLS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
THE ADVNG WK SFC LOW IS PROGGED TO CONT TO ADVN UP AND EVENTUALLY
OFF THE MID ATLANTIC COAST TNGT. AGAIN...MOST PCPN SHOULD RMN TO
OUR E HOWEVER MENTIONED LOW CHC POPS FOR AREAS NE-SE OF PIT WHERE
AGAIN A BRF PD OF LGT FRZG RAIN IS PSBL FOR THE MD/WV MOUNTAINS
AND IN COLDER VLY LOCATIONS NE OF PIT.

A DIGGING UPR TROF IS PROGGED TO ADVN FM THE CNTRL CONUS INTO THE
GT LKS RGN BY THU. MDL SOLNS VARY...BUT GIVEN THE DIGGING TROF
THINK THE NAM IS SGFNTLY UNDERDOING THE DVLPMNT OF SFC FEATURES...
SO SIDED CLOSER TO THE GFS/ECMWF. SVRL SHRTWVS ROTATING ARND THE
TROF WL BRING INCRG RAIN CHCS INTO MID WK. DVLPG SFC LOW PRES IS
PROGGED TO ADVN FM THE GULF COAST INTO THE LWR GT LKS TUE NGT INTO
WED EVE. AN ASSOCIATED CDFNT IS PROGGED FOR A WED EVE/NGT
PASSAGE...WITH THE UPR TROF AXIS PROGGED FOR A CHRISTMAS DAY PASSAGE.
ANY RAIN SHWRS SHOULD MIX WITH AND CHG TO SNW SHWRS AS COLDER AIR
ADVCTS IN AFT FROPA...AND THE UPR TROF CROSSES...THOUGH NO SGFNT
ACCUMS ARE EXPD ATTM. TIGHTENING PRES GRADIENT WED NGT AND THU
SHOULD ALSO BRING GUSTY WNDS.

ABV AVG ERLY TO MID WK TEMPS SHOULD RTN TO SEASONAL LVLS BY THU.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
THE RMNDR OF THE LONG TERM PD IS PROGGED TO FEATURE SEASONAL
TEMPS WITH A LATE WEEK COOLING TREND AS MDLS PROG A REAMPLIFYING
FLOW PTN WITH ERN CONUS TROFG AND RTNG PCPN CHCS.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
GENL IMPROVEMENT TO VFR FOR ALL TAF SITES CAN BE EXPECTED FOR THE
TAF PD AS SLY FLOW ALOFT INTENSIFIES OVR LINGERING SFC HIGH PRES.

OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
MIDWRN LOW PRES WL SPREAD RAIN AND RESTRICTIONS OVR AREA PORTS ON
TUESDAY AND WEDNESDAY. IMPROVEMENTS ARE EXPECTED TO BE INITIATED
LTR ON THURSDAY WITH DRY SHRTWV RIDGING.

&&

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

&&

$$






000
FXUS61 KPBZ 220849
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
349 AM EST MON DEC 22 2014

.SYNOPSIS...
MIDWESTERN LOW PRESSURE WILL BRING WARMER TEMPERATURES AND RAIN TO
THE REGION FOR THE FIRST HALF OF THE WEEK. SNOW SHOWER CHANCES WILL
COME WITH THE PASSAGE OF THAT SYSTEMS COLD FRONT ON CHRISTMAS.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLDS ARE EXPD TO INCR TDA IN WRM ADVCTN. A WK SFC LOW IS EXPD TO
ADVN UP THE E COAST INTO THE CAROLINAS TDA...THOUGH RECENT UPR
AIR CHARTS AND MESO DATA INDICATE MOST IF NOT ALL PCPN SHOULD RMN
TO OUR E. WITH COLD AIR DAMMING IN SE FLOW...IF ANY PCPN WERE TO
RCH GARRETT OR TUCKER COUNTIES...A BRF PD OF LGT FRZG RAIN IS
PSBL. CONTD WITH LOW CHC POPS IN THESE AREAS. HIGHS SHOULD AVG A
LTL ABV THE SEASONAL LVLS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
THE ADVNG WK SFC LOW IS PROGGED TO CONT TO ADVN UP AND EVENTUALLY
OFF THE MID ATLANTIC COAST TNGT. AGAIN...MOST PCPN SHOULD RMN TO
OUR E HOWEVER MENTIONED LOW CHC POPS FOR AREAS NE-SE OF PIT WHERE
AGAIN A BRF PD OF LGT FRZG RAIN IS PSBL FOR THE MD/WV MOUNTAINS
AND IN COLDER VLY LOCATIONS NE OF PIT.

A DIGGING UPR TROF IS PROGGED TO ADVN FM THE CNTRL CONUS INTO THE
GT LKS RGN BY THU. MDL SOLNS VARY...BUT GIVEN THE DIGGING TROF
THINK THE NAM IS SGFNTLY UNDERDOING THE DVLPMNT OF SFC FEATURES...
SO SIDED CLOSER TO THE GFS/ECMWF. SVRL SHRTWVS ROTATING ARND THE
TROF WL BRING INCRG RAIN CHCS INTO MID WK. DVLPG SFC LOW PRES IS
PROGGED TO ADVN FM THE GULF COAST INTO THE LWR GT LKS TUE NGT INTO
WED EVE. AN ASSOCIATED CDFNT IS PROGGED FOR A WED EVE/NGT
PASSAGE...WITH THE UPR TROF AXIS PROGGED FOR A CHRISTMAS DAY PASSAGE.
ANY RAIN SHWRS SHOULD MIX WITH AND CHG TO SNW SHWRS AS COLDER AIR
ADVCTS IN AFT FROPA...AND THE UPR TROF CROSSES...THOUGH NO SGFNT
ACCUMS ARE EXPD ATTM. TIGHTENING PRES GRADIENT WED NGT AND THU
SHOULD ALSO BRING GUSTY WNDS.

ABV AVG ERLY TO MID WK TEMPS SHOULD RTN TO SEASONAL LVLS BY THU.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
THE RMNDR OF THE LONG TERM PD IS PROGGED TO FEATURE SEASONAL
TEMPS WITH A LATE WEEK COOLING TREND AS MDLS PROG A REAMPLIFYING
FLOW PTN WITH ERN CONUS TROFG AND RTNG PCPN CHCS.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
GENL IMPROVEMENT TO VFR FOR ALL TAF SITES CAN BE EXPECTED FOR THE
TAF PD AS SLY FLOW ALOFT INTENSIFIES OVR LINGERING SFC HIGH PRES.

OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
MIDWRN LOW PRES WL SPREAD RAIN AND RESTRICTIONS OVR AREA PORTS ON
TUESDAY AND WEDNESDAY. IMPROVEMENTS ARE EXPECTED TO BE INITIATED
LTR ON THURSDAY WITH DRY SHRTWV RIDGING.

&&

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

&&

$$






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000
FXUS61 KPHI 220848
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
348 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER EASTERN CANADA EARLY THIS MORNING
WILL CONTINUE TO DRIFT EASTWARD AND IT WILL LOSE ITS INFLUENCE
OVER OUR REGION GRADUALLY. WEAK LOW PRESSURE IS FORECAST TO
DEVELOP OFF THE NORTH CAROLINA COAST TODAY. THE LOW IS EXPECTED TO
MOVE NORTHWARD AND IT SHOULD DISSIPATE OFF THE NEW JERSEY COAST ON
TUESDAY. ANOTHER AREA OF LOW PRESSURE IS ANTICIPATED TO DEVELOP
OVER THE NORTHWESTERN GULF OF MEXICO ON TUESDAY AND IT IS FORECAST
TO STRENGTHEN AS IT LIFTS NORTHWARD AND ACROSS THE EASTERN GREAT
LAKES ON WEDNESDAY NIGHT. THE LOW IS EXPECTED TO PULL A WARM FRONT
THROUGH OUR REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT EARLY ON
THURSDAY. HIGH PRESSURE IS FORECAST TO BUILD INTO OUR AREA FROM
THE SOUTHWEST FOR THURSDAY AND FRIDAY. ANOTHER COLD FRONT FROM THE
WEST IS EXPECTED TO ARRIVE OVER THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE REMAINS ACROSS EASTERN CANADA AND EXTENDS SOUTHWARD
ACROSS THE EAST COAST THIS MORNING, ALTHOUGH IT WILL BEGIN TO
RETREAT THROUGH THE DAY AND LOSE IT`S INFLUENCE OVER THE AREA.
THIS HAS ALLOWED THE STRATOCU CLOUD DECK TO REMAIN ACROSS THE AREA
AND BUILD SOUTHWARD. WHERE THIS CLOUD DECK IS TEMPERATURES HAVE
REMAINED WARMEST, AND WHERE SKIES WERE CLEAR OR ONLY MID/HIGH
LEVEL CLOUDS TEMPERATURES HAVE COOLED OFF. AS WE GO THROUGH THE
MORNING AND THROUGH MIDDAY, WE EXPECT THE LOW CLOUD DECK TO BEGIN
PULLING NORTHWARD AS THE HIGH RETREATS AND A SHORT WAVE/VORT MAX
LIFTS ACROSS THE AREA. HOWEVER, THESE CLOUDS WILL BE REPLACED BY
ADDITIONAL CLOUDS ADVECTING INTO THE AREA FROM THE SOUTH AHEAD OF
AN APPROACHING COASTAL LOW TO OUR SOUTH. LOW-MID LEVEL MOISTURE
WILL INCREASE AHEAD OF THE COASTAL LOW, AND AS SEVERAL PIECES OF
VORTICITY MOVE ACROSS THE AREA IN THE SOUTHWEST FLOW ALOFT, RAIN
CHANCES WILL INCREASE THROUGH THE AFTERNOON. THE BEST
LIFT/MOISTURE SHOULD BEGIN MOVING INTO OUR SOUTHERN AREAS DURING
THE AFTERNOON, ALTHOUGH THERE COULD BE SOME SHOWERS ACROSS OUR
SOUTHERN AREAS AS SOON AS LATE MORNING.

WHERE THE PRECIPITATION FALLS DURING THE DAY, IT SHOULD BE ALL
LIQUID RAIN AS TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING
WHERE THE PRECIPITATION CHANCES ARE MOST LIKELY. HOWEVER, THERE IS
STILL A CHANCE THAT SOME SNOW AND/OR SLEET MAY MIX WITH ANY RAIN
AT THE ONSET OF THE PRECIPITATION, ESPECIALLY FOR AREAS NORTH AND
WEST OF THE DELAWARE VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
THE COASTAL LOW CONTINUES TO LIFT NORTHWARD THIS EVENING AND
OVERNIGHT TOWARD OUR AREA. THIS WILL CONTINUE TO ALLOW LOW-MID
LEVEL MOISTURE TO SPREAD ACROSS OUR AREA. ADDITIONAL PIECES OF
VORTICITY WILL CONTINUE TO MOVE ACROSS THE AREA WITHIN THE
SOUTHWEST FLOW ALOFT, LEADING TO ENHANCED LOW-MID LEVEL LIFT. THE
BEST LIFT/MOISTURE WILL MOVE FROM SOUTH TO NORTH OVERNIGHT AND
WILL LIKELY AFFECT ALL AREAS AT SOME POINT DURING THE EVENING AND
OVERNIGHT. MOST AREAS WILL WARM ABOVE FREEZING BEFORE THE MAIN
PRECIPITATION MOVES INTO THOSE AREA. HOWEVER, THE NORTHERN THREE
COUNTIES (CARBON/MONROE, PENNSYLVANIA AND SUSSEX, NEW JERSEY) WILL
LIKELY TAKE LONGER TO SCOUR OUT THE COLD AIR. THEREFORE WE EXPECT
A PERIOD OF FREEZING RAIN TO OCCUR ACROSS THESE AREAS LATER THIS
EVENING AND OVERNIGHT. THERE COULD BE SOME SLEET AND/OR SNOW MIX
IN AT THE ONSET OF THE PRECIPITATION, BUT THE MAIN THREAT IS
EXPECTED TO BE FREEZING RAIN. THEREFORE WE HAVE ISSUED A FREEZING
RAIN ADVISORY FOR THESE AREAS FOR THIS EVENING AND INTO THE
OVERNIGHT HOURS. ALL PRECIPITATION IS EXPECTED TO CHANGE OVER TO
ALL RAIN BY DAYBREAK TUESDAY, SO THE ADVISORY WILL END AT 4 AM.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
THE MID LEVEL PATTERN IS EXPECTED TO FEATURE A LOW OVER IOWA WITH
A TROUGH EXTENDING DOWN TO THE SOUTHERN PLAINS ON TUESDAY MORNING.
MEANWHILE, A RIDGE WILL BE LOCATED OVER THE WESTERN NORTH
ATLANTIC. OUR REGION IS FORECAST TO BE UNDER AN INCREASINGLY MOIST
AND RELATIVELY MILD SOUTHWESTERLY FLOW FOR TUESDAY AND WEDNESDAY.

THE INITIAL MID LEVEL LOW IS ANTICIPATED TO LIFT OVER CENTRAL
ONTARIO ON TUESDAY NIGHT WITH ANOTHER LOW DEVELOPING OVER EASTERN
OKLAHOMA AND VICINITY AT THAT TIME. THE SECOND MID LEVEL LOW
SHOULD REACH SOUTHEASTERN ONTARIO LATE ON WEDNESDAY NIGHT AND
QUEBEC ON THURSDAY, WHEN IT SHOULD PULL ITS TROUGH AXIS OVER OUR
REGION. OUR WEATHER IS EXPECTED TO BE RATHER UNSETTLED THROUGH
THAT TIME, WITH PERIODS OF RAIN FROM TUESDAY INTO WEDNESDAY NIGHT,
TAPERING TO RAIN SHOWERS ON THURSDAY MORNING BEFORE ENDING.
FORECAST TEMPERATURE PROFILES FOR THAT PERIOD SUGGEST ALL LIQUID
PRECIPITATION.

A LIGHT SURFACE FLOW FROM THE EAST TO SOUTH QUADRANT IS FORECAST
FOR TUESDAY AND TUESDAY NIGHT. THE WIND IS EXPECTED TO SETTLE INTO
THE SOUTH ON WEDNESDAY AS A WARM FRONT LIFTS THROUGH OUR REGION.
TEMPERATURES ARE ANTICIPATED TO BECOME QUITE MILD ON WEDNESDAY
WITH MAXIMUM READINGS IN THE 50S AND 60S.

AS OUR MID WEEK WEATHER SYSTEM EVOLVES, IT WILL HAVE AMPLE
OPPORTUNITY TO TAP INTO MOISTURE FROM THE GULF OF MEXICO WHICH IT
WILL DRAW IN OUR DIRECTION. A LOW LEVEL JET AROUND 45 TO 55 KNOTS
IS EXPECTED TO DEVELOP OVER THE COASTAL PLAIN. THE STRONGEST OF
THE WINDS SHOULD HAVE A DIFFICULT TIME MIXING TO THE SURFACE.
HOWEVER, SOME GUSTS AROUND 30 OR 35 MPH SEEM POSSIBLE. THE SYSTEM
IS ANTICIPATED TO PULL A COLD FRONT THROUGH OUR REGION EARLY ON
CHRISTMAS MORNING SIGNALING THE BEGINNING OF THE END OF THE RAIN
EVENT AS WELL AS A RETURN TO NEAR SEASONABLE TEMPERATURES FOR THE
BALANCE OF THE WEEK AND INTO THE WEEKEND.

THE MODELS HAVE BEEN TRENDING TOWARD LOWER RAINFALL AMOUNTS FOR
THE MID WEEK EVENT THAN THEY HAD BEEN SHOWING OVER PREVIOUS DAYS.
THE GENERAL CONSENSUS SUGGESTS RAINFALL TOTALS MAINLY IN THE 0.75
TO 1.25 INCH RANGE FOR OUR REGION. WE SHOULD BE ABLE TO HANDLE
THOSE AMOUNTS BASED ON ANTECEDENT CONDITIONS WITH NOT MUCH MORE
THAN SOME LOCALIZED FLOODING IN AREAS OF POOR DRAINAGE.

THE MODEL GUIDANCE CONTINUES TO DIFFER ON THE HANDLING OF THE MID
LEVEL SHORT WAVE AND THE ACCOMPANYING COLD FRONT FOR THE COMING
WEEKEND. WE WILL KEEP THE MENTION OF A SLIGHT CHANCE OF SNOW
SHOWERS AND RAIN SHOWERS FOR THE TIME BEING WITH THE HOPE THAT THE
MODELS WILL COME INTO BETTER AGREEMENT DURING THEIR SUBSEQUENT
RUNS.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

MVFR CIGS REMAIN ACROSS THE NORTHERN HALF OF THE AREA AS THE
STRATO CUMULUS CLOUD DECK REMAINS ACROSS THE AREA. THIS DECK MAY
SAG DOWN ACROSS PHL AND RDG THIS MORNING. WE EXPECT THIS CLOUD
DECK TO RETREAT NORTHWARD DURING THE DAY, WITH A BRIEF PERIOD OF
VFR CONDITIONS POSSIBLE. HOWEVER, THIS WILL BE TEMPORARY AS
ADDITIONAL MVFR CIGS SHOULD RETURN TO THE TAF SITES BY THE LATE
AFTERNOON/EVENING HOURS AS RAINFALL MOVES INTO THE AREA. AS WE
MOVE INTO THE EVENING AND OVERNIGHT HOURS, WE EXPECT CIGS TO LOWER
TO IFR WITH LIGHT RAIN OR DRIZZLE CONTINUING INTO THE OVERNIGHT
HOURS.

WINDS ARE MOSTLY LIGHT AND VARIABLE/CALM THIS MORNING, ALTHOUGH
ANY WIND DIRECTION IS FROM THE NORTHWEST-NORTH. WINDS WILL
INCREASE TO AROUND 5 KNOTS OUT OF THE NORTHEAST-EAST DURING THE
DAY AND CONTINUE INTO THIS EVENING AND OVERNIGHT.

OUTLOOK...
TUESDAY...CONDITIONS POSSIBLY LOWERING INTO THE MVFR CATEGORY
WITH A CHANCE OF LIGHT RAIN.

TUESDAY NIGHT...MVFR AND IFR CONDITIONS ANTICIPATED WITH RAIN
LIKELY.

WEDNESDAY AND WEDNESDAY NIGHT...MVFR AND IFR CONDITIONS WITH RAIN
LIKELY. THE RAIN MAY BE HEAVY AT TIMES.

THURSDAY...CONDITIONS IMPROVING TO VFR WITH A GUSTY WEST WIND.

THURSDAY NIGHT AND FRIDAY...MAINLY VFR.

&&

.MARINE...
CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS TODAY AS HIGH PRESSURE TO OUR NORTH BEGINS TO RETREAT. AS A
COASTAL LOW APPROACHES THE AREA THIS EVENING AND OVERNIGHT, WINDS
MAY BEGIN TO INCREASE AND COULD GUST TO AROUND 20 KNOTS. SEAS
AROUND 1-2 FEET THIS MORNING WILL INCREASE LATER TODAY AND
ESPECIALLY OVERNIGHT AS THE COASTAL LOW APPROACHES AND SEAS MAY
BEGIN TO APPROACH 4 FEET.

OUTLOOK...
TUESDAY AND TUESDAY NIGHT...WAVE HEIGHTS ON OUR OCEAN WATERS MAY
BUILD TO 5 FEET IN A DEVELOPING EAST TO SOUTH FLOW.

WEDNESDAY...SOUTHERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 6 TO 9
FEET.

WEDNESDAY NIGHT...A SOUTH WIND BECOMING WEST. WIND GUSTS IN
EXCESS OF 25 KNOTS ARE EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS
MAY BE 6 TO 9 FEET.

THURSDAY...WESTERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. LOCALIZED GALE FORCE GUSTS ARE POSSIBLE. WAVE HEIGHTS ON
OUR OCEAN WATERS MAY BE TO 5 TO 7 FEET.

THURSDAY NIGHT...WIND GUSTS AND WAVE HEIGHTS ARE FORECAST TO FALL
GRADUALLY BELOW THE SMALL CRAFT ADVISORY CRITERIA.

FRIDAY...NO MARINE HEADLINES ARE ANTICIPATED.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM EST
     TUESDAY FOR PAZ054-055.
NJ...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM EST
     TUESDAY FOR NJZ001.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...IOVINO
NEAR TERM...ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/ROBERTSON
MARINE...IOVINO/ROBERTSON






000
FXUS61 KPHI 220848
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
348 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER EASTERN CANADA EARLY THIS MORNING
WILL CONTINUE TO DRIFT EASTWARD AND IT WILL LOSE ITS INFLUENCE
OVER OUR REGION GRADUALLY. WEAK LOW PRESSURE IS FORECAST TO
DEVELOP OFF THE NORTH CAROLINA COAST TODAY. THE LOW IS EXPECTED TO
MOVE NORTHWARD AND IT SHOULD DISSIPATE OFF THE NEW JERSEY COAST ON
TUESDAY. ANOTHER AREA OF LOW PRESSURE IS ANTICIPATED TO DEVELOP
OVER THE NORTHWESTERN GULF OF MEXICO ON TUESDAY AND IT IS FORECAST
TO STRENGTHEN AS IT LIFTS NORTHWARD AND ACROSS THE EASTERN GREAT
LAKES ON WEDNESDAY NIGHT. THE LOW IS EXPECTED TO PULL A WARM FRONT
THROUGH OUR REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT EARLY ON
THURSDAY. HIGH PRESSURE IS FORECAST TO BUILD INTO OUR AREA FROM
THE SOUTHWEST FOR THURSDAY AND FRIDAY. ANOTHER COLD FRONT FROM THE
WEST IS EXPECTED TO ARRIVE OVER THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE REMAINS ACROSS EASTERN CANADA AND EXTENDS SOUTHWARD
ACROSS THE EAST COAST THIS MORNING, ALTHOUGH IT WILL BEGIN TO
RETREAT THROUGH THE DAY AND LOSE IT`S INFLUENCE OVER THE AREA.
THIS HAS ALLOWED THE STRATOCU CLOUD DECK TO REMAIN ACROSS THE AREA
AND BUILD SOUTHWARD. WHERE THIS CLOUD DECK IS TEMPERATURES HAVE
REMAINED WARMEST, AND WHERE SKIES WERE CLEAR OR ONLY MID/HIGH
LEVEL CLOUDS TEMPERATURES HAVE COOLED OFF. AS WE GO THROUGH THE
MORNING AND THROUGH MIDDAY, WE EXPECT THE LOW CLOUD DECK TO BEGIN
PULLING NORTHWARD AS THE HIGH RETREATS AND A SHORT WAVE/VORT MAX
LIFTS ACROSS THE AREA. HOWEVER, THESE CLOUDS WILL BE REPLACED BY
ADDITIONAL CLOUDS ADVECTING INTO THE AREA FROM THE SOUTH AHEAD OF
AN APPROACHING COASTAL LOW TO OUR SOUTH. LOW-MID LEVEL MOISTURE
WILL INCREASE AHEAD OF THE COASTAL LOW, AND AS SEVERAL PIECES OF
VORTICITY MOVE ACROSS THE AREA IN THE SOUTHWEST FLOW ALOFT, RAIN
CHANCES WILL INCREASE THROUGH THE AFTERNOON. THE BEST
LIFT/MOISTURE SHOULD BEGIN MOVING INTO OUR SOUTHERN AREAS DURING
THE AFTERNOON, ALTHOUGH THERE COULD BE SOME SHOWERS ACROSS OUR
SOUTHERN AREAS AS SOON AS LATE MORNING.

WHERE THE PRECIPITATION FALLS DURING THE DAY, IT SHOULD BE ALL
LIQUID RAIN AS TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING
WHERE THE PRECIPITATION CHANCES ARE MOST LIKELY. HOWEVER, THERE IS
STILL A CHANCE THAT SOME SNOW AND/OR SLEET MAY MIX WITH ANY RAIN
AT THE ONSET OF THE PRECIPITATION, ESPECIALLY FOR AREAS NORTH AND
WEST OF THE DELAWARE VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
THE COASTAL LOW CONTINUES TO LIFT NORTHWARD THIS EVENING AND
OVERNIGHT TOWARD OUR AREA. THIS WILL CONTINUE TO ALLOW LOW-MID
LEVEL MOISTURE TO SPREAD ACROSS OUR AREA. ADDITIONAL PIECES OF
VORTICITY WILL CONTINUE TO MOVE ACROSS THE AREA WITHIN THE
SOUTHWEST FLOW ALOFT, LEADING TO ENHANCED LOW-MID LEVEL LIFT. THE
BEST LIFT/MOISTURE WILL MOVE FROM SOUTH TO NORTH OVERNIGHT AND
WILL LIKELY AFFECT ALL AREAS AT SOME POINT DURING THE EVENING AND
OVERNIGHT. MOST AREAS WILL WARM ABOVE FREEZING BEFORE THE MAIN
PRECIPITATION MOVES INTO THOSE AREA. HOWEVER, THE NORTHERN THREE
COUNTIES (CARBON/MONROE, PENNSYLVANIA AND SUSSEX, NEW JERSEY) WILL
LIKELY TAKE LONGER TO SCOUR OUT THE COLD AIR. THEREFORE WE EXPECT
A PERIOD OF FREEZING RAIN TO OCCUR ACROSS THESE AREAS LATER THIS
EVENING AND OVERNIGHT. THERE COULD BE SOME SLEET AND/OR SNOW MIX
IN AT THE ONSET OF THE PRECIPITATION, BUT THE MAIN THREAT IS
EXPECTED TO BE FREEZING RAIN. THEREFORE WE HAVE ISSUED A FREEZING
RAIN ADVISORY FOR THESE AREAS FOR THIS EVENING AND INTO THE
OVERNIGHT HOURS. ALL PRECIPITATION IS EXPECTED TO CHANGE OVER TO
ALL RAIN BY DAYBREAK TUESDAY, SO THE ADVISORY WILL END AT 4 AM.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
THE MID LEVEL PATTERN IS EXPECTED TO FEATURE A LOW OVER IOWA WITH
A TROUGH EXTENDING DOWN TO THE SOUTHERN PLAINS ON TUESDAY MORNING.
MEANWHILE, A RIDGE WILL BE LOCATED OVER THE WESTERN NORTH
ATLANTIC. OUR REGION IS FORECAST TO BE UNDER AN INCREASINGLY MOIST
AND RELATIVELY MILD SOUTHWESTERLY FLOW FOR TUESDAY AND WEDNESDAY.

THE INITIAL MID LEVEL LOW IS ANTICIPATED TO LIFT OVER CENTRAL
ONTARIO ON TUESDAY NIGHT WITH ANOTHER LOW DEVELOPING OVER EASTERN
OKLAHOMA AND VICINITY AT THAT TIME. THE SECOND MID LEVEL LOW
SHOULD REACH SOUTHEASTERN ONTARIO LATE ON WEDNESDAY NIGHT AND
QUEBEC ON THURSDAY, WHEN IT SHOULD PULL ITS TROUGH AXIS OVER OUR
REGION. OUR WEATHER IS EXPECTED TO BE RATHER UNSETTLED THROUGH
THAT TIME, WITH PERIODS OF RAIN FROM TUESDAY INTO WEDNESDAY NIGHT,
TAPERING TO RAIN SHOWERS ON THURSDAY MORNING BEFORE ENDING.
FORECAST TEMPERATURE PROFILES FOR THAT PERIOD SUGGEST ALL LIQUID
PRECIPITATION.

A LIGHT SURFACE FLOW FROM THE EAST TO SOUTH QUADRANT IS FORECAST
FOR TUESDAY AND TUESDAY NIGHT. THE WIND IS EXPECTED TO SETTLE INTO
THE SOUTH ON WEDNESDAY AS A WARM FRONT LIFTS THROUGH OUR REGION.
TEMPERATURES ARE ANTICIPATED TO BECOME QUITE MILD ON WEDNESDAY
WITH MAXIMUM READINGS IN THE 50S AND 60S.

AS OUR MID WEEK WEATHER SYSTEM EVOLVES, IT WILL HAVE AMPLE
OPPORTUNITY TO TAP INTO MOISTURE FROM THE GULF OF MEXICO WHICH IT
WILL DRAW IN OUR DIRECTION. A LOW LEVEL JET AROUND 45 TO 55 KNOTS
IS EXPECTED TO DEVELOP OVER THE COASTAL PLAIN. THE STRONGEST OF
THE WINDS SHOULD HAVE A DIFFICULT TIME MIXING TO THE SURFACE.
HOWEVER, SOME GUSTS AROUND 30 OR 35 MPH SEEM POSSIBLE. THE SYSTEM
IS ANTICIPATED TO PULL A COLD FRONT THROUGH OUR REGION EARLY ON
CHRISTMAS MORNING SIGNALING THE BEGINNING OF THE END OF THE RAIN
EVENT AS WELL AS A RETURN TO NEAR SEASONABLE TEMPERATURES FOR THE
BALANCE OF THE WEEK AND INTO THE WEEKEND.

THE MODELS HAVE BEEN TRENDING TOWARD LOWER RAINFALL AMOUNTS FOR
THE MID WEEK EVENT THAN THEY HAD BEEN SHOWING OVER PREVIOUS DAYS.
THE GENERAL CONSENSUS SUGGESTS RAINFALL TOTALS MAINLY IN THE 0.75
TO 1.25 INCH RANGE FOR OUR REGION. WE SHOULD BE ABLE TO HANDLE
THOSE AMOUNTS BASED ON ANTECEDENT CONDITIONS WITH NOT MUCH MORE
THAN SOME LOCALIZED FLOODING IN AREAS OF POOR DRAINAGE.

THE MODEL GUIDANCE CONTINUES TO DIFFER ON THE HANDLING OF THE MID
LEVEL SHORT WAVE AND THE ACCOMPANYING COLD FRONT FOR THE COMING
WEEKEND. WE WILL KEEP THE MENTION OF A SLIGHT CHANCE OF SNOW
SHOWERS AND RAIN SHOWERS FOR THE TIME BEING WITH THE HOPE THAT THE
MODELS WILL COME INTO BETTER AGREEMENT DURING THEIR SUBSEQUENT
RUNS.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

MVFR CIGS REMAIN ACROSS THE NORTHERN HALF OF THE AREA AS THE
STRATO CUMULUS CLOUD DECK REMAINS ACROSS THE AREA. THIS DECK MAY
SAG DOWN ACROSS PHL AND RDG THIS MORNING. WE EXPECT THIS CLOUD
DECK TO RETREAT NORTHWARD DURING THE DAY, WITH A BRIEF PERIOD OF
VFR CONDITIONS POSSIBLE. HOWEVER, THIS WILL BE TEMPORARY AS
ADDITIONAL MVFR CIGS SHOULD RETURN TO THE TAF SITES BY THE LATE
AFTERNOON/EVENING HOURS AS RAINFALL MOVES INTO THE AREA. AS WE
MOVE INTO THE EVENING AND OVERNIGHT HOURS, WE EXPECT CIGS TO LOWER
TO IFR WITH LIGHT RAIN OR DRIZZLE CONTINUING INTO THE OVERNIGHT
HOURS.

WINDS ARE MOSTLY LIGHT AND VARIABLE/CALM THIS MORNING, ALTHOUGH
ANY WIND DIRECTION IS FROM THE NORTHWEST-NORTH. WINDS WILL
INCREASE TO AROUND 5 KNOTS OUT OF THE NORTHEAST-EAST DURING THE
DAY AND CONTINUE INTO THIS EVENING AND OVERNIGHT.

OUTLOOK...
TUESDAY...CONDITIONS POSSIBLY LOWERING INTO THE MVFR CATEGORY
WITH A CHANCE OF LIGHT RAIN.

TUESDAY NIGHT...MVFR AND IFR CONDITIONS ANTICIPATED WITH RAIN
LIKELY.

WEDNESDAY AND WEDNESDAY NIGHT...MVFR AND IFR CONDITIONS WITH RAIN
LIKELY. THE RAIN MAY BE HEAVY AT TIMES.

THURSDAY...CONDITIONS IMPROVING TO VFR WITH A GUSTY WEST WIND.

THURSDAY NIGHT AND FRIDAY...MAINLY VFR.

&&

.MARINE...
CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS TODAY AS HIGH PRESSURE TO OUR NORTH BEGINS TO RETREAT. AS A
COASTAL LOW APPROACHES THE AREA THIS EVENING AND OVERNIGHT, WINDS
MAY BEGIN TO INCREASE AND COULD GUST TO AROUND 20 KNOTS. SEAS
AROUND 1-2 FEET THIS MORNING WILL INCREASE LATER TODAY AND
ESPECIALLY OVERNIGHT AS THE COASTAL LOW APPROACHES AND SEAS MAY
BEGIN TO APPROACH 4 FEET.

OUTLOOK...
TUESDAY AND TUESDAY NIGHT...WAVE HEIGHTS ON OUR OCEAN WATERS MAY
BUILD TO 5 FEET IN A DEVELOPING EAST TO SOUTH FLOW.

WEDNESDAY...SOUTHERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 6 TO 9
FEET.

WEDNESDAY NIGHT...A SOUTH WIND BECOMING WEST. WIND GUSTS IN
EXCESS OF 25 KNOTS ARE EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS
MAY BE 6 TO 9 FEET.

THURSDAY...WESTERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. LOCALIZED GALE FORCE GUSTS ARE POSSIBLE. WAVE HEIGHTS ON
OUR OCEAN WATERS MAY BE TO 5 TO 7 FEET.

THURSDAY NIGHT...WIND GUSTS AND WAVE HEIGHTS ARE FORECAST TO FALL
GRADUALLY BELOW THE SMALL CRAFT ADVISORY CRITERIA.

FRIDAY...NO MARINE HEADLINES ARE ANTICIPATED.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM EST
     TUESDAY FOR PAZ054-055.
NJ...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM EST
     TUESDAY FOR NJZ001.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...IOVINO
NEAR TERM...ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/ROBERTSON
MARINE...IOVINO/ROBERTSON






000
FXUS61 KPHI 220848
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
348 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER EASTERN CANADA EARLY THIS MORNING
WILL CONTINUE TO DRIFT EASTWARD AND IT WILL LOSE ITS INFLUENCE
OVER OUR REGION GRADUALLY. WEAK LOW PRESSURE IS FORECAST TO
DEVELOP OFF THE NORTH CAROLINA COAST TODAY. THE LOW IS EXPECTED TO
MOVE NORTHWARD AND IT SHOULD DISSIPATE OFF THE NEW JERSEY COAST ON
TUESDAY. ANOTHER AREA OF LOW PRESSURE IS ANTICIPATED TO DEVELOP
OVER THE NORTHWESTERN GULF OF MEXICO ON TUESDAY AND IT IS FORECAST
TO STRENGTHEN AS IT LIFTS NORTHWARD AND ACROSS THE EASTERN GREAT
LAKES ON WEDNESDAY NIGHT. THE LOW IS EXPECTED TO PULL A WARM FRONT
THROUGH OUR REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT EARLY ON
THURSDAY. HIGH PRESSURE IS FORECAST TO BUILD INTO OUR AREA FROM
THE SOUTHWEST FOR THURSDAY AND FRIDAY. ANOTHER COLD FRONT FROM THE
WEST IS EXPECTED TO ARRIVE OVER THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE REMAINS ACROSS EASTERN CANADA AND EXTENDS SOUTHWARD
ACROSS THE EAST COAST THIS MORNING, ALTHOUGH IT WILL BEGIN TO
RETREAT THROUGH THE DAY AND LOSE IT`S INFLUENCE OVER THE AREA.
THIS HAS ALLOWED THE STRATOCU CLOUD DECK TO REMAIN ACROSS THE AREA
AND BUILD SOUTHWARD. WHERE THIS CLOUD DECK IS TEMPERATURES HAVE
REMAINED WARMEST, AND WHERE SKIES WERE CLEAR OR ONLY MID/HIGH
LEVEL CLOUDS TEMPERATURES HAVE COOLED OFF. AS WE GO THROUGH THE
MORNING AND THROUGH MIDDAY, WE EXPECT THE LOW CLOUD DECK TO BEGIN
PULLING NORTHWARD AS THE HIGH RETREATS AND A SHORT WAVE/VORT MAX
LIFTS ACROSS THE AREA. HOWEVER, THESE CLOUDS WILL BE REPLACED BY
ADDITIONAL CLOUDS ADVECTING INTO THE AREA FROM THE SOUTH AHEAD OF
AN APPROACHING COASTAL LOW TO OUR SOUTH. LOW-MID LEVEL MOISTURE
WILL INCREASE AHEAD OF THE COASTAL LOW, AND AS SEVERAL PIECES OF
VORTICITY MOVE ACROSS THE AREA IN THE SOUTHWEST FLOW ALOFT, RAIN
CHANCES WILL INCREASE THROUGH THE AFTERNOON. THE BEST
LIFT/MOISTURE SHOULD BEGIN MOVING INTO OUR SOUTHERN AREAS DURING
THE AFTERNOON, ALTHOUGH THERE COULD BE SOME SHOWERS ACROSS OUR
SOUTHERN AREAS AS SOON AS LATE MORNING.

WHERE THE PRECIPITATION FALLS DURING THE DAY, IT SHOULD BE ALL
LIQUID RAIN AS TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING
WHERE THE PRECIPITATION CHANCES ARE MOST LIKELY. HOWEVER, THERE IS
STILL A CHANCE THAT SOME SNOW AND/OR SLEET MAY MIX WITH ANY RAIN
AT THE ONSET OF THE PRECIPITATION, ESPECIALLY FOR AREAS NORTH AND
WEST OF THE DELAWARE VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
THE COASTAL LOW CONTINUES TO LIFT NORTHWARD THIS EVENING AND
OVERNIGHT TOWARD OUR AREA. THIS WILL CONTINUE TO ALLOW LOW-MID
LEVEL MOISTURE TO SPREAD ACROSS OUR AREA. ADDITIONAL PIECES OF
VORTICITY WILL CONTINUE TO MOVE ACROSS THE AREA WITHIN THE
SOUTHWEST FLOW ALOFT, LEADING TO ENHANCED LOW-MID LEVEL LIFT. THE
BEST LIFT/MOISTURE WILL MOVE FROM SOUTH TO NORTH OVERNIGHT AND
WILL LIKELY AFFECT ALL AREAS AT SOME POINT DURING THE EVENING AND
OVERNIGHT. MOST AREAS WILL WARM ABOVE FREEZING BEFORE THE MAIN
PRECIPITATION MOVES INTO THOSE AREA. HOWEVER, THE NORTHERN THREE
COUNTIES (CARBON/MONROE, PENNSYLVANIA AND SUSSEX, NEW JERSEY) WILL
LIKELY TAKE LONGER TO SCOUR OUT THE COLD AIR. THEREFORE WE EXPECT
A PERIOD OF FREEZING RAIN TO OCCUR ACROSS THESE AREAS LATER THIS
EVENING AND OVERNIGHT. THERE COULD BE SOME SLEET AND/OR SNOW MIX
IN AT THE ONSET OF THE PRECIPITATION, BUT THE MAIN THREAT IS
EXPECTED TO BE FREEZING RAIN. THEREFORE WE HAVE ISSUED A FREEZING
RAIN ADVISORY FOR THESE AREAS FOR THIS EVENING AND INTO THE
OVERNIGHT HOURS. ALL PRECIPITATION IS EXPECTED TO CHANGE OVER TO
ALL RAIN BY DAYBREAK TUESDAY, SO THE ADVISORY WILL END AT 4 AM.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
THE MID LEVEL PATTERN IS EXPECTED TO FEATURE A LOW OVER IOWA WITH
A TROUGH EXTENDING DOWN TO THE SOUTHERN PLAINS ON TUESDAY MORNING.
MEANWHILE, A RIDGE WILL BE LOCATED OVER THE WESTERN NORTH
ATLANTIC. OUR REGION IS FORECAST TO BE UNDER AN INCREASINGLY MOIST
AND RELATIVELY MILD SOUTHWESTERLY FLOW FOR TUESDAY AND WEDNESDAY.

THE INITIAL MID LEVEL LOW IS ANTICIPATED TO LIFT OVER CENTRAL
ONTARIO ON TUESDAY NIGHT WITH ANOTHER LOW DEVELOPING OVER EASTERN
OKLAHOMA AND VICINITY AT THAT TIME. THE SECOND MID LEVEL LOW
SHOULD REACH SOUTHEASTERN ONTARIO LATE ON WEDNESDAY NIGHT AND
QUEBEC ON THURSDAY, WHEN IT SHOULD PULL ITS TROUGH AXIS OVER OUR
REGION. OUR WEATHER IS EXPECTED TO BE RATHER UNSETTLED THROUGH
THAT TIME, WITH PERIODS OF RAIN FROM TUESDAY INTO WEDNESDAY NIGHT,
TAPERING TO RAIN SHOWERS ON THURSDAY MORNING BEFORE ENDING.
FORECAST TEMPERATURE PROFILES FOR THAT PERIOD SUGGEST ALL LIQUID
PRECIPITATION.

A LIGHT SURFACE FLOW FROM THE EAST TO SOUTH QUADRANT IS FORECAST
FOR TUESDAY AND TUESDAY NIGHT. THE WIND IS EXPECTED TO SETTLE INTO
THE SOUTH ON WEDNESDAY AS A WARM FRONT LIFTS THROUGH OUR REGION.
TEMPERATURES ARE ANTICIPATED TO BECOME QUITE MILD ON WEDNESDAY
WITH MAXIMUM READINGS IN THE 50S AND 60S.

AS OUR MID WEEK WEATHER SYSTEM EVOLVES, IT WILL HAVE AMPLE
OPPORTUNITY TO TAP INTO MOISTURE FROM THE GULF OF MEXICO WHICH IT
WILL DRAW IN OUR DIRECTION. A LOW LEVEL JET AROUND 45 TO 55 KNOTS
IS EXPECTED TO DEVELOP OVER THE COASTAL PLAIN. THE STRONGEST OF
THE WINDS SHOULD HAVE A DIFFICULT TIME MIXING TO THE SURFACE.
HOWEVER, SOME GUSTS AROUND 30 OR 35 MPH SEEM POSSIBLE. THE SYSTEM
IS ANTICIPATED TO PULL A COLD FRONT THROUGH OUR REGION EARLY ON
CHRISTMAS MORNING SIGNALING THE BEGINNING OF THE END OF THE RAIN
EVENT AS WELL AS A RETURN TO NEAR SEASONABLE TEMPERATURES FOR THE
BALANCE OF THE WEEK AND INTO THE WEEKEND.

THE MODELS HAVE BEEN TRENDING TOWARD LOWER RAINFALL AMOUNTS FOR
THE MID WEEK EVENT THAN THEY HAD BEEN SHOWING OVER PREVIOUS DAYS.
THE GENERAL CONSENSUS SUGGESTS RAINFALL TOTALS MAINLY IN THE 0.75
TO 1.25 INCH RANGE FOR OUR REGION. WE SHOULD BE ABLE TO HANDLE
THOSE AMOUNTS BASED ON ANTECEDENT CONDITIONS WITH NOT MUCH MORE
THAN SOME LOCALIZED FLOODING IN AREAS OF POOR DRAINAGE.

THE MODEL GUIDANCE CONTINUES TO DIFFER ON THE HANDLING OF THE MID
LEVEL SHORT WAVE AND THE ACCOMPANYING COLD FRONT FOR THE COMING
WEEKEND. WE WILL KEEP THE MENTION OF A SLIGHT CHANCE OF SNOW
SHOWERS AND RAIN SHOWERS FOR THE TIME BEING WITH THE HOPE THAT THE
MODELS WILL COME INTO BETTER AGREEMENT DURING THEIR SUBSEQUENT
RUNS.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

MVFR CIGS REMAIN ACROSS THE NORTHERN HALF OF THE AREA AS THE
STRATO CUMULUS CLOUD DECK REMAINS ACROSS THE AREA. THIS DECK MAY
SAG DOWN ACROSS PHL AND RDG THIS MORNING. WE EXPECT THIS CLOUD
DECK TO RETREAT NORTHWARD DURING THE DAY, WITH A BRIEF PERIOD OF
VFR CONDITIONS POSSIBLE. HOWEVER, THIS WILL BE TEMPORARY AS
ADDITIONAL MVFR CIGS SHOULD RETURN TO THE TAF SITES BY THE LATE
AFTERNOON/EVENING HOURS AS RAINFALL MOVES INTO THE AREA. AS WE
MOVE INTO THE EVENING AND OVERNIGHT HOURS, WE EXPECT CIGS TO LOWER
TO IFR WITH LIGHT RAIN OR DRIZZLE CONTINUING INTO THE OVERNIGHT
HOURS.

WINDS ARE MOSTLY LIGHT AND VARIABLE/CALM THIS MORNING, ALTHOUGH
ANY WIND DIRECTION IS FROM THE NORTHWEST-NORTH. WINDS WILL
INCREASE TO AROUND 5 KNOTS OUT OF THE NORTHEAST-EAST DURING THE
DAY AND CONTINUE INTO THIS EVENING AND OVERNIGHT.

OUTLOOK...
TUESDAY...CONDITIONS POSSIBLY LOWERING INTO THE MVFR CATEGORY
WITH A CHANCE OF LIGHT RAIN.

TUESDAY NIGHT...MVFR AND IFR CONDITIONS ANTICIPATED WITH RAIN
LIKELY.

WEDNESDAY AND WEDNESDAY NIGHT...MVFR AND IFR CONDITIONS WITH RAIN
LIKELY. THE RAIN MAY BE HEAVY AT TIMES.

THURSDAY...CONDITIONS IMPROVING TO VFR WITH A GUSTY WEST WIND.

THURSDAY NIGHT AND FRIDAY...MAINLY VFR.

&&

.MARINE...
CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS TODAY AS HIGH PRESSURE TO OUR NORTH BEGINS TO RETREAT. AS A
COASTAL LOW APPROACHES THE AREA THIS EVENING AND OVERNIGHT, WINDS
MAY BEGIN TO INCREASE AND COULD GUST TO AROUND 20 KNOTS. SEAS
AROUND 1-2 FEET THIS MORNING WILL INCREASE LATER TODAY AND
ESPECIALLY OVERNIGHT AS THE COASTAL LOW APPROACHES AND SEAS MAY
BEGIN TO APPROACH 4 FEET.

OUTLOOK...
TUESDAY AND TUESDAY NIGHT...WAVE HEIGHTS ON OUR OCEAN WATERS MAY
BUILD TO 5 FEET IN A DEVELOPING EAST TO SOUTH FLOW.

WEDNESDAY...SOUTHERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 6 TO 9
FEET.

WEDNESDAY NIGHT...A SOUTH WIND BECOMING WEST. WIND GUSTS IN
EXCESS OF 25 KNOTS ARE EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS
MAY BE 6 TO 9 FEET.

THURSDAY...WESTERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. LOCALIZED GALE FORCE GUSTS ARE POSSIBLE. WAVE HEIGHTS ON
OUR OCEAN WATERS MAY BE TO 5 TO 7 FEET.

THURSDAY NIGHT...WIND GUSTS AND WAVE HEIGHTS ARE FORECAST TO FALL
GRADUALLY BELOW THE SMALL CRAFT ADVISORY CRITERIA.

FRIDAY...NO MARINE HEADLINES ARE ANTICIPATED.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM EST
     TUESDAY FOR PAZ054-055.
NJ...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM EST
     TUESDAY FOR NJZ001.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...IOVINO
NEAR TERM...ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/ROBERTSON
MARINE...IOVINO/ROBERTSON






000
FXUS61 KPHI 220848
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
348 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER EASTERN CANADA EARLY THIS MORNING
WILL CONTINUE TO DRIFT EASTWARD AND IT WILL LOSE ITS INFLUENCE
OVER OUR REGION GRADUALLY. WEAK LOW PRESSURE IS FORECAST TO
DEVELOP OFF THE NORTH CAROLINA COAST TODAY. THE LOW IS EXPECTED TO
MOVE NORTHWARD AND IT SHOULD DISSIPATE OFF THE NEW JERSEY COAST ON
TUESDAY. ANOTHER AREA OF LOW PRESSURE IS ANTICIPATED TO DEVELOP
OVER THE NORTHWESTERN GULF OF MEXICO ON TUESDAY AND IT IS FORECAST
TO STRENGTHEN AS IT LIFTS NORTHWARD AND ACROSS THE EASTERN GREAT
LAKES ON WEDNESDAY NIGHT. THE LOW IS EXPECTED TO PULL A WARM FRONT
THROUGH OUR REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT EARLY ON
THURSDAY. HIGH PRESSURE IS FORECAST TO BUILD INTO OUR AREA FROM
THE SOUTHWEST FOR THURSDAY AND FRIDAY. ANOTHER COLD FRONT FROM THE
WEST IS EXPECTED TO ARRIVE OVER THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE REMAINS ACROSS EASTERN CANADA AND EXTENDS SOUTHWARD
ACROSS THE EAST COAST THIS MORNING, ALTHOUGH IT WILL BEGIN TO
RETREAT THROUGH THE DAY AND LOSE IT`S INFLUENCE OVER THE AREA.
THIS HAS ALLOWED THE STRATOCU CLOUD DECK TO REMAIN ACROSS THE AREA
AND BUILD SOUTHWARD. WHERE THIS CLOUD DECK IS TEMPERATURES HAVE
REMAINED WARMEST, AND WHERE SKIES WERE CLEAR OR ONLY MID/HIGH
LEVEL CLOUDS TEMPERATURES HAVE COOLED OFF. AS WE GO THROUGH THE
MORNING AND THROUGH MIDDAY, WE EXPECT THE LOW CLOUD DECK TO BEGIN
PULLING NORTHWARD AS THE HIGH RETREATS AND A SHORT WAVE/VORT MAX
LIFTS ACROSS THE AREA. HOWEVER, THESE CLOUDS WILL BE REPLACED BY
ADDITIONAL CLOUDS ADVECTING INTO THE AREA FROM THE SOUTH AHEAD OF
AN APPROACHING COASTAL LOW TO OUR SOUTH. LOW-MID LEVEL MOISTURE
WILL INCREASE AHEAD OF THE COASTAL LOW, AND AS SEVERAL PIECES OF
VORTICITY MOVE ACROSS THE AREA IN THE SOUTHWEST FLOW ALOFT, RAIN
CHANCES WILL INCREASE THROUGH THE AFTERNOON. THE BEST
LIFT/MOISTURE SHOULD BEGIN MOVING INTO OUR SOUTHERN AREAS DURING
THE AFTERNOON, ALTHOUGH THERE COULD BE SOME SHOWERS ACROSS OUR
SOUTHERN AREAS AS SOON AS LATE MORNING.

WHERE THE PRECIPITATION FALLS DURING THE DAY, IT SHOULD BE ALL
LIQUID RAIN AS TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING
WHERE THE PRECIPITATION CHANCES ARE MOST LIKELY. HOWEVER, THERE IS
STILL A CHANCE THAT SOME SNOW AND/OR SLEET MAY MIX WITH ANY RAIN
AT THE ONSET OF THE PRECIPITATION, ESPECIALLY FOR AREAS NORTH AND
WEST OF THE DELAWARE VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
THE COASTAL LOW CONTINUES TO LIFT NORTHWARD THIS EVENING AND
OVERNIGHT TOWARD OUR AREA. THIS WILL CONTINUE TO ALLOW LOW-MID
LEVEL MOISTURE TO SPREAD ACROSS OUR AREA. ADDITIONAL PIECES OF
VORTICITY WILL CONTINUE TO MOVE ACROSS THE AREA WITHIN THE
SOUTHWEST FLOW ALOFT, LEADING TO ENHANCED LOW-MID LEVEL LIFT. THE
BEST LIFT/MOISTURE WILL MOVE FROM SOUTH TO NORTH OVERNIGHT AND
WILL LIKELY AFFECT ALL AREAS AT SOME POINT DURING THE EVENING AND
OVERNIGHT. MOST AREAS WILL WARM ABOVE FREEZING BEFORE THE MAIN
PRECIPITATION MOVES INTO THOSE AREA. HOWEVER, THE NORTHERN THREE
COUNTIES (CARBON/MONROE, PENNSYLVANIA AND SUSSEX, NEW JERSEY) WILL
LIKELY TAKE LONGER TO SCOUR OUT THE COLD AIR. THEREFORE WE EXPECT
A PERIOD OF FREEZING RAIN TO OCCUR ACROSS THESE AREAS LATER THIS
EVENING AND OVERNIGHT. THERE COULD BE SOME SLEET AND/OR SNOW MIX
IN AT THE ONSET OF THE PRECIPITATION, BUT THE MAIN THREAT IS
EXPECTED TO BE FREEZING RAIN. THEREFORE WE HAVE ISSUED A FREEZING
RAIN ADVISORY FOR THESE AREAS FOR THIS EVENING AND INTO THE
OVERNIGHT HOURS. ALL PRECIPITATION IS EXPECTED TO CHANGE OVER TO
ALL RAIN BY DAYBREAK TUESDAY, SO THE ADVISORY WILL END AT 4 AM.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
THE MID LEVEL PATTERN IS EXPECTED TO FEATURE A LOW OVER IOWA WITH
A TROUGH EXTENDING DOWN TO THE SOUTHERN PLAINS ON TUESDAY MORNING.
MEANWHILE, A RIDGE WILL BE LOCATED OVER THE WESTERN NORTH
ATLANTIC. OUR REGION IS FORECAST TO BE UNDER AN INCREASINGLY MOIST
AND RELATIVELY MILD SOUTHWESTERLY FLOW FOR TUESDAY AND WEDNESDAY.

THE INITIAL MID LEVEL LOW IS ANTICIPATED TO LIFT OVER CENTRAL
ONTARIO ON TUESDAY NIGHT WITH ANOTHER LOW DEVELOPING OVER EASTERN
OKLAHOMA AND VICINITY AT THAT TIME. THE SECOND MID LEVEL LOW
SHOULD REACH SOUTHEASTERN ONTARIO LATE ON WEDNESDAY NIGHT AND
QUEBEC ON THURSDAY, WHEN IT SHOULD PULL ITS TROUGH AXIS OVER OUR
REGION. OUR WEATHER IS EXPECTED TO BE RATHER UNSETTLED THROUGH
THAT TIME, WITH PERIODS OF RAIN FROM TUESDAY INTO WEDNESDAY NIGHT,
TAPERING TO RAIN SHOWERS ON THURSDAY MORNING BEFORE ENDING.
FORECAST TEMPERATURE PROFILES FOR THAT PERIOD SUGGEST ALL LIQUID
PRECIPITATION.

A LIGHT SURFACE FLOW FROM THE EAST TO SOUTH QUADRANT IS FORECAST
FOR TUESDAY AND TUESDAY NIGHT. THE WIND IS EXPECTED TO SETTLE INTO
THE SOUTH ON WEDNESDAY AS A WARM FRONT LIFTS THROUGH OUR REGION.
TEMPERATURES ARE ANTICIPATED TO BECOME QUITE MILD ON WEDNESDAY
WITH MAXIMUM READINGS IN THE 50S AND 60S.

AS OUR MID WEEK WEATHER SYSTEM EVOLVES, IT WILL HAVE AMPLE
OPPORTUNITY TO TAP INTO MOISTURE FROM THE GULF OF MEXICO WHICH IT
WILL DRAW IN OUR DIRECTION. A LOW LEVEL JET AROUND 45 TO 55 KNOTS
IS EXPECTED TO DEVELOP OVER THE COASTAL PLAIN. THE STRONGEST OF
THE WINDS SHOULD HAVE A DIFFICULT TIME MIXING TO THE SURFACE.
HOWEVER, SOME GUSTS AROUND 30 OR 35 MPH SEEM POSSIBLE. THE SYSTEM
IS ANTICIPATED TO PULL A COLD FRONT THROUGH OUR REGION EARLY ON
CHRISTMAS MORNING SIGNALING THE BEGINNING OF THE END OF THE RAIN
EVENT AS WELL AS A RETURN TO NEAR SEASONABLE TEMPERATURES FOR THE
BALANCE OF THE WEEK AND INTO THE WEEKEND.

THE MODELS HAVE BEEN TRENDING TOWARD LOWER RAINFALL AMOUNTS FOR
THE MID WEEK EVENT THAN THEY HAD BEEN SHOWING OVER PREVIOUS DAYS.
THE GENERAL CONSENSUS SUGGESTS RAINFALL TOTALS MAINLY IN THE 0.75
TO 1.25 INCH RANGE FOR OUR REGION. WE SHOULD BE ABLE TO HANDLE
THOSE AMOUNTS BASED ON ANTECEDENT CONDITIONS WITH NOT MUCH MORE
THAN SOME LOCALIZED FLOODING IN AREAS OF POOR DRAINAGE.

THE MODEL GUIDANCE CONTINUES TO DIFFER ON THE HANDLING OF THE MID
LEVEL SHORT WAVE AND THE ACCOMPANYING COLD FRONT FOR THE COMING
WEEKEND. WE WILL KEEP THE MENTION OF A SLIGHT CHANCE OF SNOW
SHOWERS AND RAIN SHOWERS FOR THE TIME BEING WITH THE HOPE THAT THE
MODELS WILL COME INTO BETTER AGREEMENT DURING THEIR SUBSEQUENT
RUNS.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

MVFR CIGS REMAIN ACROSS THE NORTHERN HALF OF THE AREA AS THE
STRATO CUMULUS CLOUD DECK REMAINS ACROSS THE AREA. THIS DECK MAY
SAG DOWN ACROSS PHL AND RDG THIS MORNING. WE EXPECT THIS CLOUD
DECK TO RETREAT NORTHWARD DURING THE DAY, WITH A BRIEF PERIOD OF
VFR CONDITIONS POSSIBLE. HOWEVER, THIS WILL BE TEMPORARY AS
ADDITIONAL MVFR CIGS SHOULD RETURN TO THE TAF SITES BY THE LATE
AFTERNOON/EVENING HOURS AS RAINFALL MOVES INTO THE AREA. AS WE
MOVE INTO THE EVENING AND OVERNIGHT HOURS, WE EXPECT CIGS TO LOWER
TO IFR WITH LIGHT RAIN OR DRIZZLE CONTINUING INTO THE OVERNIGHT
HOURS.

WINDS ARE MOSTLY LIGHT AND VARIABLE/CALM THIS MORNING, ALTHOUGH
ANY WIND DIRECTION IS FROM THE NORTHWEST-NORTH. WINDS WILL
INCREASE TO AROUND 5 KNOTS OUT OF THE NORTHEAST-EAST DURING THE
DAY AND CONTINUE INTO THIS EVENING AND OVERNIGHT.

OUTLOOK...
TUESDAY...CONDITIONS POSSIBLY LOWERING INTO THE MVFR CATEGORY
WITH A CHANCE OF LIGHT RAIN.

TUESDAY NIGHT...MVFR AND IFR CONDITIONS ANTICIPATED WITH RAIN
LIKELY.

WEDNESDAY AND WEDNESDAY NIGHT...MVFR AND IFR CONDITIONS WITH RAIN
LIKELY. THE RAIN MAY BE HEAVY AT TIMES.

THURSDAY...CONDITIONS IMPROVING TO VFR WITH A GUSTY WEST WIND.

THURSDAY NIGHT AND FRIDAY...MAINLY VFR.

&&

.MARINE...
CONDITIONS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS TODAY AS HIGH PRESSURE TO OUR NORTH BEGINS TO RETREAT. AS A
COASTAL LOW APPROACHES THE AREA THIS EVENING AND OVERNIGHT, WINDS
MAY BEGIN TO INCREASE AND COULD GUST TO AROUND 20 KNOTS. SEAS
AROUND 1-2 FEET THIS MORNING WILL INCREASE LATER TODAY AND
ESPECIALLY OVERNIGHT AS THE COASTAL LOW APPROACHES AND SEAS MAY
BEGIN TO APPROACH 4 FEET.

OUTLOOK...
TUESDAY AND TUESDAY NIGHT...WAVE HEIGHTS ON OUR OCEAN WATERS MAY
BUILD TO 5 FEET IN A DEVELOPING EAST TO SOUTH FLOW.

WEDNESDAY...SOUTHERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 6 TO 9
FEET.

WEDNESDAY NIGHT...A SOUTH WIND BECOMING WEST. WIND GUSTS IN
EXCESS OF 25 KNOTS ARE EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS
MAY BE 6 TO 9 FEET.

THURSDAY...WESTERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. LOCALIZED GALE FORCE GUSTS ARE POSSIBLE. WAVE HEIGHTS ON
OUR OCEAN WATERS MAY BE TO 5 TO 7 FEET.

THURSDAY NIGHT...WIND GUSTS AND WAVE HEIGHTS ARE FORECAST TO FALL
GRADUALLY BELOW THE SMALL CRAFT ADVISORY CRITERIA.

FRIDAY...NO MARINE HEADLINES ARE ANTICIPATED.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM EST
     TUESDAY FOR PAZ054-055.
NJ...FREEZING RAIN ADVISORY FROM 6 PM THIS EVENING TO 4 AM EST
     TUESDAY FOR NJZ001.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...IOVINO
NEAR TERM...ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/ROBERTSON
MARINE...IOVINO/ROBERTSON





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000
FXUS61 KAKQ 220842
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
342 AM EST MON DEC 22 2014

.SYNOPSIS...
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG
THE CAROLINA COAST TODAY THROUGH TUESDAY. A STRONG COLD FRONT WILL
CROSS THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS
DAY.

&&

.NEAR TERM /TOODAY/...
THIS MORNING...PCPN QUICKLY OVRSPREADING THE FA SW-NE BUT STAYING
MAINLY EAST OF AREAS WHERE TMPS ARE AOB FREEZING...SO NO P-TYPE
ISSUES NOTED AS OF THIS WRITING. APPEARS PCPN WILL EVENTUALLY GET
TO THE NWRN CNTYS BY OR SHORTLY AFTR 12Z. GIVEN CRNT TMP/DP TMPS...
HAVE ADDED GOOCHLAND CNTY (WRN HALF MAINLY WEST OF ST RT 522 TO THE
ADVSRY). WET BULBS ACROSS THE ADVSRY AREA HOVER AOB 32 THRU THE
MORNING HRS...SO THE ZR ADVSRY WILL REMAIN IN PLACE. OTHER THAN A
FEW IP AT THE ONSET... EXPECT A COLD RAIN TO OVERSPREAD THE AREA
WITH TMPS STEADY IN THE 30S XCPT 40S SERN CSTL AREAS.

THIS AFTERNOON...LOW PRS TRACKS NE ALONG THE OUTER BANKS KEEPING A
N-NE FLOW ACROSS THE FA AS HIGH PRS RETREATS INTO NEW ENGLAND. BEST
LIFT AND OMEGA PROGGED BTWN 16Z-00Z. POPS INCRSD TO NEAR 100% ALL
AREAS. THUS...XPCT A COLD / WET AFTRN AHEAD AS IN-SITU WEDGE CONTS.
PCPN ALL LIQUID AS TMPS INCH JUST ABV FREEZING ACROSS NWRN MOST CNTYS.
TMPS BTWN 35-40 ALONG AND W OF I95...40-45 TO THE COASTAL AREAS XCPT
U40S-L50S SERN COASTAL AREAS.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
THIS EVENING...SFC LOW PRS PROGGED TO TRACK NNE JUST OFF THE DELMARVA
PENINSULA TONIGHT REACHING THE SRN NJ COAST BY 12Z TUE. BEST SPRT FOR
WDSPRD PCPN SHIFTS TOWARD THE DELMARVA. SO RAIN CHCS CONT THIS EVENING
WITH THE HIGHEST ALONG THE COAST. TMPS STDY M30S-L40S.

OVERNIGHT...WDPSRD LL MSTR SEEN IN TSCTNS AFTR MIDNIGHT. SO ALTHOUGH
THE STDY AND HVNST RAINS SHUD END AS THE PUSH NE...XPCT AREAS OF LGT
RAIN/DRIZZLE AND FOG THRU THE NIGHT. TMPS STDY M30S-L40S. TOTAL QPF
NEXT 24 HRS RANGE BTWN ONE QUARTER TO ONE HALF INCH...UP TO THREE
QUARTERS INCH ACROSS INTERIOR NE NC.

TUESDAY...THE UNSETTLED PTRN CONTINUES AS LOW PRS IS SLOW TO PULL NE
DUE TO A STRONG SSW FLOW ALOFT AS AN AMPLIFIED UPPER LEVEL TROUGH
SLOWLY TRACKS EAST FROM THE PLAINS STATES MON NIGHT...THROUGH THE
MID ATLC AND SE STATES WED NIGHT. LOW LEVELS REMAIN SATURATED SO
MAINTAINED A CHC FOR RAIN WITH AREAS OF DRIZZLE AND FOG TUE. GIVEN
AN OVERRUNNING PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE...WENT
WITH THE COOLER GUID NMBRS. HIGHS TUE RANGE FROM THE M-U40S ALONG
AND WEST OF I-95 TO THE M-U50S IN SERN VA/NE NC.

TUE NIGHT / WEDNESDAY...SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. DECENT MODEL AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE FROM
THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS SOAR
INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW ON
WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING TSTMS
ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO BE MUCH
IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL CAPE) ON
WED TO LEAD TO SEVERE WX. HIGHS WED INTO THE M-U60S TO AROUND 70 F
(CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS WED...SHIFTING
OFF THE COAST LATER WED EVENING AS THE COLD FRONT PUSHES THROUGH AND
DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO CHRISTMAS MORNING.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE FORMING OFF THE SC COAST ALONG WITH HIGH PRESSURE
WEDGING SOUTH WILL CREATE A SETUP FOR A COOL/RAINY PERIOD LATER
THIS MORNING THROUGH TONIGHT WITH MVFR/IFR VIS/CIGS EXPECTED. AS
THE LOW MOVES NORTH...OVER- RUNNING PRECIP WILL TRACK S TO N LATER
THIS MORNING...EVENTUALLY REACHING EVERY AKQ TAF SITE. SOME
IP/FZRA POSSIBLE AT SMALLER AIRPORTS W/NW OF KRIC /E.G. KLKU/KFVX/
BETWEEN 12-16Z. EXPECT A BRIEF PERIOD OF 15-20 KT WIND GUSTS ALONG
THE COAST AS THE LOW MOVES NORTH AND THE PRESSURE GRADIENT
TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES THROUGH WEDNESDAY. A COLD FRONT PASSES THROUGH
WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY AND
FRIDAY. A PERIOD OF GUSTY WINDS EXPECTED WEDNESDAY AFTERNOON
THROUGH MIDDAY THURSDAY AHEAD OF AND BEHIND THE FRONT.

&&

.MARINE...
SFC LOW PRESSURE CONTINUES TO MOVE NORTHEAST OFF THE NC COAST
TODAY...THEN WEAKENS TONIGHT AS IT REACHES THE DELMARVA. E-NE WINDS
WILL GENERALLY AVG 10-15 KT TODAY ON THE MIDDLE BAY AND THE
RIVERS...AND 15-20 KNOTS FOR THE COASTAL WATERS/LOWER BAY/CURRITUCK
SOUND. MIGHT EVEN GET SOME GUSTS TO 25 KNOTS OVER THE SOUTHERN
WATERS. WAVES BUILD TO 3-4 FT ON THE LOWER BAY TODAY...WITH SEAS 3-4
FT ON THE OCEAN...EXCEPT UP TO 5 FT SOUTH. DID GO AHEAD AND ADD THE
COASTAL ZONE SOUTH OF CAPE CHARLES TO THE SCA AS SEAS LOOK TO REACH
5 FT OFFSHORE. WINDS WILL DIMINISH QUICKLY TONIGHT WITH THE LOW
LIFTING NORTH...REMAINING FROM AN E-NE DIRECTION NORTH AND TURNING
OFFSHORE SOUTH. THERE IS THE POTENTIAL FOR SEAS TO BUILD TO 5 FT OUT
AROUND 20 NM ACROSS THE NORTHERN WATERS TONIGHT...BUT CONFIDENCE NOT
HIGH ENOUGH TO RAISE AN SCA ATTM.

LIGHT AND VARIABLE WINDS WILL BECOME E-SE TUES AS HIGH PRESSURE
REMAINS IN PLACE OVER THE MID-ATLANTIC...AND THE NEXT LOW PRESSURE
SYSTEM ORGANIZES OVER THE DEEP SOUTH. SE WINDS GRADUALLY BEGIN TO
INCREASE TUESDAY NIGHT AS A WARM FRONT LIFTS NORTH THROUGH THE AREA.
A STRONG COLD FRONT APPROACHES THE WATERS FROM THE WEST ON WEDNESDAY
WITH WINDS BECOMING SOUTHERLY AND INCREASING TO SCA THRESHOLDS (SAVE
THE RIVERS). THE FRONT QUICKLY SWEEPS THROUGH THE AREA WED NIGHT AND
OFFSHORE EARLY THURSDAY. WINDS REMAIN ABOVE SCA LEVELS THRU LATE
THURSDAY WHILE BECOMING SW THEN W. HIGH PRESSURE RETURNS THU NIGHT
INTO THE START OF NEXT WEEKEND FOR IMPROVED CONDITIONS. SEAS WILL
GENERALLY BUILD TO 5-7 FT ON WED BEFORE SUBSIDING AGAIN BY LATE THU.
WAVES WILL REACH 4 FT ON THE CHES BAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR VAZ048-049-
     060>062.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR ANZ633.
     SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR ANZ656-658.

&&

$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...JDM
MARINE...JDM






000
FXUS61 KAKQ 220842
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
342 AM EST MON DEC 22 2014

.SYNOPSIS...
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG
THE CAROLINA COAST TODAY THROUGH TUESDAY. A STRONG COLD FRONT WILL
CROSS THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS
DAY.

&&

.NEAR TERM /TOODAY/...
THIS MORNING...PCPN QUICKLY OVRSPREADING THE FA SW-NE BUT STAYING
MAINLY EAST OF AREAS WHERE TMPS ARE AOB FREEZING...SO NO P-TYPE
ISSUES NOTED AS OF THIS WRITING. APPEARS PCPN WILL EVENTUALLY GET
TO THE NWRN CNTYS BY OR SHORTLY AFTR 12Z. GIVEN CRNT TMP/DP TMPS...
HAVE ADDED GOOCHLAND CNTY (WRN HALF MAINLY WEST OF ST RT 522 TO THE
ADVSRY). WET BULBS ACROSS THE ADVSRY AREA HOVER AOB 32 THRU THE
MORNING HRS...SO THE ZR ADVSRY WILL REMAIN IN PLACE. OTHER THAN A
FEW IP AT THE ONSET... EXPECT A COLD RAIN TO OVERSPREAD THE AREA
WITH TMPS STEADY IN THE 30S XCPT 40S SERN CSTL AREAS.

THIS AFTERNOON...LOW PRS TRACKS NE ALONG THE OUTER BANKS KEEPING A
N-NE FLOW ACROSS THE FA AS HIGH PRS RETREATS INTO NEW ENGLAND. BEST
LIFT AND OMEGA PROGGED BTWN 16Z-00Z. POPS INCRSD TO NEAR 100% ALL
AREAS. THUS...XPCT A COLD / WET AFTRN AHEAD AS IN-SITU WEDGE CONTS.
PCPN ALL LIQUID AS TMPS INCH JUST ABV FREEZING ACROSS NWRN MOST CNTYS.
TMPS BTWN 35-40 ALONG AND W OF I95...40-45 TO THE COASTAL AREAS XCPT
U40S-L50S SERN COASTAL AREAS.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
THIS EVENING...SFC LOW PRS PROGGED TO TRACK NNE JUST OFF THE DELMARVA
PENINSULA TONIGHT REACHING THE SRN NJ COAST BY 12Z TUE. BEST SPRT FOR
WDSPRD PCPN SHIFTS TOWARD THE DELMARVA. SO RAIN CHCS CONT THIS EVENING
WITH THE HIGHEST ALONG THE COAST. TMPS STDY M30S-L40S.

OVERNIGHT...WDPSRD LL MSTR SEEN IN TSCTNS AFTR MIDNIGHT. SO ALTHOUGH
THE STDY AND HVNST RAINS SHUD END AS THE PUSH NE...XPCT AREAS OF LGT
RAIN/DRIZZLE AND FOG THRU THE NIGHT. TMPS STDY M30S-L40S. TOTAL QPF
NEXT 24 HRS RANGE BTWN ONE QUARTER TO ONE HALF INCH...UP TO THREE
QUARTERS INCH ACROSS INTERIOR NE NC.

TUESDAY...THE UNSETTLED PTRN CONTINUES AS LOW PRS IS SLOW TO PULL NE
DUE TO A STRONG SSW FLOW ALOFT AS AN AMPLIFIED UPPER LEVEL TROUGH
SLOWLY TRACKS EAST FROM THE PLAINS STATES MON NIGHT...THROUGH THE
MID ATLC AND SE STATES WED NIGHT. LOW LEVELS REMAIN SATURATED SO
MAINTAINED A CHC FOR RAIN WITH AREAS OF DRIZZLE AND FOG TUE. GIVEN
AN OVERRUNNING PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE...WENT
WITH THE COOLER GUID NMBRS. HIGHS TUE RANGE FROM THE M-U40S ALONG
AND WEST OF I-95 TO THE M-U50S IN SERN VA/NE NC.

TUE NIGHT / WEDNESDAY...SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. DECENT MODEL AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE FROM
THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS SOAR
INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW ON
WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING TSTMS
ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO BE MUCH
IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL CAPE) ON
WED TO LEAD TO SEVERE WX. HIGHS WED INTO THE M-U60S TO AROUND 70 F
(CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS WED...SHIFTING
OFF THE COAST LATER WED EVENING AS THE COLD FRONT PUSHES THROUGH AND
DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO CHRISTMAS MORNING.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /09Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE FORMING OFF THE SC COAST ALONG WITH HIGH PRESSURE
WEDGING SOUTH WILL CREATE A SETUP FOR A COOL/RAINY PERIOD LATER
THIS MORNING THROUGH TONIGHT WITH MVFR/IFR VIS/CIGS EXPECTED. AS
THE LOW MOVES NORTH...OVER- RUNNING PRECIP WILL TRACK S TO N LATER
THIS MORNING...EVENTUALLY REACHING EVERY AKQ TAF SITE. SOME
IP/FZRA POSSIBLE AT SMALLER AIRPORTS W/NW OF KRIC /E.G. KLKU/KFVX/
BETWEEN 12-16Z. EXPECT A BRIEF PERIOD OF 15-20 KT WIND GUSTS ALONG
THE COAST AS THE LOW MOVES NORTH AND THE PRESSURE GRADIENT
TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES THROUGH WEDNESDAY. A COLD FRONT PASSES THROUGH
WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY AND
FRIDAY. A PERIOD OF GUSTY WINDS EXPECTED WEDNESDAY AFTERNOON
THROUGH MIDDAY THURSDAY AHEAD OF AND BEHIND THE FRONT.

&&

.MARINE...
SFC LOW PRESSURE CONTINUES TO MOVE NORTHEAST OFF THE NC COAST
TODAY...THEN WEAKENS TONIGHT AS IT REACHES THE DELMARVA. E-NE WINDS
WILL GENERALLY AVG 10-15 KT TODAY ON THE MIDDLE BAY AND THE
RIVERS...AND 15-20 KNOTS FOR THE COASTAL WATERS/LOWER BAY/CURRITUCK
SOUND. MIGHT EVEN GET SOME GUSTS TO 25 KNOTS OVER THE SOUTHERN
WATERS. WAVES BUILD TO 3-4 FT ON THE LOWER BAY TODAY...WITH SEAS 3-4
FT ON THE OCEAN...EXCEPT UP TO 5 FT SOUTH. DID GO AHEAD AND ADD THE
COASTAL ZONE SOUTH OF CAPE CHARLES TO THE SCA AS SEAS LOOK TO REACH
5 FT OFFSHORE. WINDS WILL DIMINISH QUICKLY TONIGHT WITH THE LOW
LIFTING NORTH...REMAINING FROM AN E-NE DIRECTION NORTH AND TURNING
OFFSHORE SOUTH. THERE IS THE POTENTIAL FOR SEAS TO BUILD TO 5 FT OUT
AROUND 20 NM ACROSS THE NORTHERN WATERS TONIGHT...BUT CONFIDENCE NOT
HIGH ENOUGH TO RAISE AN SCA ATTM.

LIGHT AND VARIABLE WINDS WILL BECOME E-SE TUES AS HIGH PRESSURE
REMAINS IN PLACE OVER THE MID-ATLANTIC...AND THE NEXT LOW PRESSURE
SYSTEM ORGANIZES OVER THE DEEP SOUTH. SE WINDS GRADUALLY BEGIN TO
INCREASE TUESDAY NIGHT AS A WARM FRONT LIFTS NORTH THROUGH THE AREA.
A STRONG COLD FRONT APPROACHES THE WATERS FROM THE WEST ON WEDNESDAY
WITH WINDS BECOMING SOUTHERLY AND INCREASING TO SCA THRESHOLDS (SAVE
THE RIVERS). THE FRONT QUICKLY SWEEPS THROUGH THE AREA WED NIGHT AND
OFFSHORE EARLY THURSDAY. WINDS REMAIN ABOVE SCA LEVELS THRU LATE
THURSDAY WHILE BECOMING SW THEN W. HIGH PRESSURE RETURNS THU NIGHT
INTO THE START OF NEXT WEEKEND FOR IMPROVED CONDITIONS. SEAS WILL
GENERALLY BUILD TO 5-7 FT ON WED BEFORE SUBSIDING AGAIN BY LATE THU.
WAVES WILL REACH 4 FT ON THE CHES BAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR VAZ048-049-
     060>062.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR ANZ633.
     SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR ANZ656-658.

&&

$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...JDM
MARINE...JDM







000
FXUS61 KAKQ 220646
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
146 AM EST MON DEC 22 2014

.SYNOPSIS...
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP
ALONG THE CAROLINA COAST TODAY THROUGH TUESDAY. A STRONG COLD
FRONT WILL CROSS THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS
BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH TODAY/...
ADJUSTED GRIDS A BIT BASED ON CRNT TRENDS FOR THE ERLY MORNING
UPDATE. MIN TEMPS HAVE BASICALY BEEN REACHED AND HAVE SHOWN SIGNS
OF RISING PAST FEW HRS SINCE THE CLOUDS HAVE MOVED IN. RAIN
COVERAGE QUICKLY EXPANDING AS IT MOVES NE ACROSS ERN NC AND INTO
SRN VA SO HAVE BUMPED UP THE POPS THRU 4 AM AND XPANDED THE RAIN
FARTHER NORTH. ALSO NOT THAT WRN PIEDMONT TEMPS ARE ABV FREEZING
(34 @ LKU...38 @ FVX)...HOWEVER WET BULB TMPS HOVERING ARND 32 SO
XPCT PCPN TO BE A RAIN/SLEET MIX AS IT BEGINS LATER ON. FREEZING
RAIN WILL LIKELY ADD TO THE MIX TOWARDS SUNRISE SO CRNT ADVSRY
REMAINS IN PLACE. TMPS STDY OR SLOWLY RISING FROM CRNT VALUES...
MAINLY IN THE 30S.

PVS DSCN:
WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTER
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTERNOON AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45
EAST TOWARD THE ERN SHORE & SERN CHES BAY...M40S-L50S NE NC.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AN UNSETTLED PERIOD...WITH STRONG SSW FLOW ALOFT AS AN AMPLIFIED
UPPER LEVEL TROUGH SLOWLY TRACKS EAST FROM THE PLAINS STATES MON
NIGHT...THROUGH THE MID ATLC AND SE STATES WED NIGHT. BULK OF LIFT
WILL PUSH OFF TO THE NE OF THE AREA MON NIGHT...BUT LOW LEVELS
REMAIN SATURATED SO WILL MAINTAIN A CHC FOR RAIN WITH AREAS OF
DRIZZLE AND FOG MENTIONED LATER MON NIGHT/TUE. GIVEN AN OVERRUNNING
PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE MON NIGHT THROUGH TUE
NIGHT...HAVE SIDED WITH THE COOLEST OF GUIDANCE FOR HIGH
TEMPERATURES TUE (CLOSEST TO THE ECWMF NUMERICAL GUIDANCE). HIGHS
TUE RANGE FROM THE MID-UPPER 40S ALONG/WEST OF I-95 TO THE MID-
UPPER 50S IN NE NC. SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. GFS/ECMWF IN GOOD AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE
FROM THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS
SOAR INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW
ON WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING
TSTMS ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO
BE MUCH IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL
CAPE) ON WED TO LEAD TO SEVERE WX. THIS WILL NEED TO BE MONITORED
FOR SUBSEQUENT CHANGES. HIGHS WED INTO THE MID-UPPER 60S TO AROUND
70 F (CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS
WED...SHIFTING OFF THE COAST LATER WED EVENING AS THE COLD FRONT
PUSHES THROUGH AND DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO
CHRISTMAS MORNING.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE FORMING OFF THE SC COAST ALONG WITH HIGH PRESSURE
WEDGING SOUTH WILL CREATE A SETUP FOR A COOL/RAINY PERIOD LATER
THIS MORNING THROUGH TONIGHT WITH MVFR/IFR VIS/CIGS EXPECTED. AS
THE LOW MOVES NORTH...OVER- RUNNING PRECIP WILL TRACK S TO N LATER
THIS MORNING...EVENTUALLY REACHING EVERY AKQ TAF SITE. SOME
IP/FZRA POSSIBLE AT SMALLER AIRPORTS W/NW OF KRIC /E.G. KLKU/KFVX/
BETWEEN 12-16Z. EXPECT A BRIEF PERIOD OF 15-20 KT WIND GUSTS ALONG
THE COAST AS THE LOW MOVES NORTH AND THE PRESSURE GRADIENT
TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES THROUGH WEDNESDAY. A COLD FRONT PASSES THROUGH
WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY AND
FRIDAY. A PERIOD OF GUSTY WINDS EXPECTED WEDNESDAY AFTERNOON
THROUGH MIDDAY THURSDAY AHEAD OF AND BEHIND THE FRONT.

&&

.MARINE...
7 PM UPDATE...HAVE RAISED SCA...MAINLY FOR INCREASING
SEAS...ACROSS THE SRN COASTAL WATERS FROM 18Z MONDAY THROUGH 03Z
TUESDAY. OTHERWISE...VERY FEW CHANGES TO WINDS/SEAS IN THIS
UPDATE.

     AFTERNOON DISCUSSION...LO PRES REMAINS LOCKED IN PLACE OVR THE
NE STATES TNGT AS LO PRES DEVELOPS OFF THE SE CST. THE LO WILL
TRACK UP THE CAROLINA CST ON MON. DESPITE SOME WAA...WITH NE FLOW
AND A TIGHTENING PRES GRADIENT...THINK WINDS WILL MAKE IT INTO THE
15-20 KT RANGE FOR BOTH THE SRN BAY AND SOUND. THEREFORE DECIDED
TO HOIST A SCA FOR THESE LOCATIONS. THINK WINDS WILL BE QUITE
CLOSE TO SCA THRESHOLDS OVR THE NRN BAY AND OCEAN AS WELL...BUT
WITH MORE UNCERTAINTY THERE WILL HOLD OFF FOR NOW AND WILL ISSUE
HAZARD NEXT SHIFT IF NEC. SEAS WILL MAINLY BE 3-4 FT...WITH SOME
SEAS UP TO 5 FT PSBL OVR SRN CST WTRS MON EVENG. THE
AFOREMENTIONED LO WEAKENS ON TUE AS A STRONG COLD FRNT APPROACHES
FM THE W AND WINDS SLOWLY BCM SELY. SCA WINDS EXPECTED BY WED OVR
ALL WTRS EXCEPT THE RIVERS. THE FRNT CROSSES THE REGION WED NGT
INTO THU MORNG...WITH SCA CONDS CONTINUING POST FRNTAL INTO THU.
SEAS WILL BLD TO 5-8 FT WED INTO THU BEFORE SUBSIDING THU NGT.
WAVES OVR THE BAY WILL REACH 3-4 FT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM EARLY THIS MORNING TO NOON
     EST TODAY FOR VAZ048-049-060-061.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR ANZ633.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM EST
     THIS EVENING FOR ANZ658.

&&

$$
SYNOPSIS...ALB/LKB/MPR
NEAR TERM...ALB/LKB/MPR
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...JDM
MARINE...MAS/WRS






000
FXUS61 KAKQ 220646
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
146 AM EST MON DEC 22 2014

.SYNOPSIS...
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP
ALONG THE CAROLINA COAST TODAY THROUGH TUESDAY. A STRONG COLD
FRONT WILL CROSS THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS
BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH TODAY/...
ADJUSTED GRIDS A BIT BASED ON CRNT TRENDS FOR THE ERLY MORNING
UPDATE. MIN TEMPS HAVE BASICALY BEEN REACHED AND HAVE SHOWN SIGNS
OF RISING PAST FEW HRS SINCE THE CLOUDS HAVE MOVED IN. RAIN
COVERAGE QUICKLY EXPANDING AS IT MOVES NE ACROSS ERN NC AND INTO
SRN VA SO HAVE BUMPED UP THE POPS THRU 4 AM AND XPANDED THE RAIN
FARTHER NORTH. ALSO NOT THAT WRN PIEDMONT TEMPS ARE ABV FREEZING
(34 @ LKU...38 @ FVX)...HOWEVER WET BULB TMPS HOVERING ARND 32 SO
XPCT PCPN TO BE A RAIN/SLEET MIX AS IT BEGINS LATER ON. FREEZING
RAIN WILL LIKELY ADD TO THE MIX TOWARDS SUNRISE SO CRNT ADVSRY
REMAINS IN PLACE. TMPS STDY OR SLOWLY RISING FROM CRNT VALUES...
MAINLY IN THE 30S.

PVS DSCN:
WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTER
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTERNOON AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45
EAST TOWARD THE ERN SHORE & SERN CHES BAY...M40S-L50S NE NC.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AN UNSETTLED PERIOD...WITH STRONG SSW FLOW ALOFT AS AN AMPLIFIED
UPPER LEVEL TROUGH SLOWLY TRACKS EAST FROM THE PLAINS STATES MON
NIGHT...THROUGH THE MID ATLC AND SE STATES WED NIGHT. BULK OF LIFT
WILL PUSH OFF TO THE NE OF THE AREA MON NIGHT...BUT LOW LEVELS
REMAIN SATURATED SO WILL MAINTAIN A CHC FOR RAIN WITH AREAS OF
DRIZZLE AND FOG MENTIONED LATER MON NIGHT/TUE. GIVEN AN OVERRUNNING
PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE MON NIGHT THROUGH TUE
NIGHT...HAVE SIDED WITH THE COOLEST OF GUIDANCE FOR HIGH
TEMPERATURES TUE (CLOSEST TO THE ECWMF NUMERICAL GUIDANCE). HIGHS
TUE RANGE FROM THE MID-UPPER 40S ALONG/WEST OF I-95 TO THE MID-
UPPER 50S IN NE NC. SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. GFS/ECMWF IN GOOD AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE
FROM THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS
SOAR INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW
ON WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING
TSTMS ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO
BE MUCH IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL
CAPE) ON WED TO LEAD TO SEVERE WX. THIS WILL NEED TO BE MONITORED
FOR SUBSEQUENT CHANGES. HIGHS WED INTO THE MID-UPPER 60S TO AROUND
70 F (CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS
WED...SHIFTING OFF THE COAST LATER WED EVENING AS THE COLD FRONT
PUSHES THROUGH AND DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO
CHRISTMAS MORNING.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE FORMING OFF THE SC COAST ALONG WITH HIGH PRESSURE
WEDGING SOUTH WILL CREATE A SETUP FOR A COOL/RAINY PERIOD LATER
THIS MORNING THROUGH TONIGHT WITH MVFR/IFR VIS/CIGS EXPECTED. AS
THE LOW MOVES NORTH...OVER- RUNNING PRECIP WILL TRACK S TO N LATER
THIS MORNING...EVENTUALLY REACHING EVERY AKQ TAF SITE. SOME
IP/FZRA POSSIBLE AT SMALLER AIRPORTS W/NW OF KRIC /E.G. KLKU/KFVX/
BETWEEN 12-16Z. EXPECT A BRIEF PERIOD OF 15-20 KT WIND GUSTS ALONG
THE COAST AS THE LOW MOVES NORTH AND THE PRESSURE GRADIENT
TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES THROUGH WEDNESDAY. A COLD FRONT PASSES THROUGH
WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY AND
FRIDAY. A PERIOD OF GUSTY WINDS EXPECTED WEDNESDAY AFTERNOON
THROUGH MIDDAY THURSDAY AHEAD OF AND BEHIND THE FRONT.

&&

.MARINE...
7 PM UPDATE...HAVE RAISED SCA...MAINLY FOR INCREASING
SEAS...ACROSS THE SRN COASTAL WATERS FROM 18Z MONDAY THROUGH 03Z
TUESDAY. OTHERWISE...VERY FEW CHANGES TO WINDS/SEAS IN THIS
UPDATE.

     AFTERNOON DISCUSSION...LO PRES REMAINS LOCKED IN PLACE OVR THE
NE STATES TNGT AS LO PRES DEVELOPS OFF THE SE CST. THE LO WILL
TRACK UP THE CAROLINA CST ON MON. DESPITE SOME WAA...WITH NE FLOW
AND A TIGHTENING PRES GRADIENT...THINK WINDS WILL MAKE IT INTO THE
15-20 KT RANGE FOR BOTH THE SRN BAY AND SOUND. THEREFORE DECIDED
TO HOIST A SCA FOR THESE LOCATIONS. THINK WINDS WILL BE QUITE
CLOSE TO SCA THRESHOLDS OVR THE NRN BAY AND OCEAN AS WELL...BUT
WITH MORE UNCERTAINTY THERE WILL HOLD OFF FOR NOW AND WILL ISSUE
HAZARD NEXT SHIFT IF NEC. SEAS WILL MAINLY BE 3-4 FT...WITH SOME
SEAS UP TO 5 FT PSBL OVR SRN CST WTRS MON EVENG. THE
AFOREMENTIONED LO WEAKENS ON TUE AS A STRONG COLD FRNT APPROACHES
FM THE W AND WINDS SLOWLY BCM SELY. SCA WINDS EXPECTED BY WED OVR
ALL WTRS EXCEPT THE RIVERS. THE FRNT CROSSES THE REGION WED NGT
INTO THU MORNG...WITH SCA CONDS CONTINUING POST FRNTAL INTO THU.
SEAS WILL BLD TO 5-8 FT WED INTO THU BEFORE SUBSIDING THU NGT.
WAVES OVR THE BAY WILL REACH 3-4 FT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM EARLY THIS MORNING TO NOON
     EST TODAY FOR VAZ048-049-060-061.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR ANZ633.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM EST
     THIS EVENING FOR ANZ658.

&&

$$
SYNOPSIS...ALB/LKB/MPR
NEAR TERM...ALB/LKB/MPR
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...JDM
MARINE...MAS/WRS







000
FXUS61 KAKQ 220606
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
106 AM EST MON DEC 22 2014

.SYNOPSIS...
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP
ALONG THE CAROLINA COAST TODAY THROUGH TUESDAY. A STRONG COLD
FRONT WILL CROSS THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS
BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH TODAY/...
ADJUSTED GRIDS A BIT BASED ON CRNT TRENDS FOR THE ERLY MORNING
UPDATE. MIN TEMPS HAVE BASICALY BEEN REACHED AND HAVE SHOWN SIGNS
OF RISING PAST FEW HRS SINCE THE CLOUDS HAVE MOVED IN. RAIN
COVERAGE QUICKLY EXPANDING AS IT MOVES NE ACROSS ERN NC AND INTO
SRN VA SO HAVE BUMPED UP THE POPS THRU 4 AM AND XPANDED THE RAIN
FARTHER NORTH. ALSO NOT THAT WRN PIEDMONT TEMPS ARE ABV FREEZING
(34 @ LKU...38 @ FVX)...HOWEVER WET BULB TMPS HOVERING ARND 32 SO
XPCT PCPN TO BE A RAIN/SLEET MIX AS IT BEGINS LATER ON. FREEZING
RAIN WILL LIKELY ADD TO THE MIX TOWARDS SUNRISE SO CRNT ADVSRY
REMAINS IN PLACE. TMPS STDY OR SLOWLY RISING FROM CRNT VALUES...
MAINLY IN THE 30S.

PVS DSCN:
WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTER
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTERNOON AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45
EAST TOWARD THE ERN SHORE & SERN CHES BAY...M40S-L50S NE NC.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AN UNSETTLED PERIOD...WITH STRONG SSW FLOW ALOFT AS AN AMPLIFIED
UPPER LEVEL TROUGH SLOWLY TRACKS EAST FROM THE PLAINS STATES MON
NIGHT...THROUGH THE MID ATLC AND SE STATES WED NIGHT. BULK OF LIFT
WILL PUSH OFF TO THE NE OF THE AREA MON NIGHT...BUT LOW LEVELS
REMAIN SATURATED SO WILL MAINTAIN A CHC FOR RAIN WITH AREAS OF
DRIZZLE AND FOG MENTIONED LATER MON NIGHT/TUE. GIVEN AN OVERRUNNING
PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE MON NIGHT THROUGH TUE
NIGHT...HAVE SIDED WITH THE COOLEST OF GUIDANCE FOR HIGH
TEMPERATURES TUE (CLOSEST TO THE ECWMF NUMERICAL GUIDANCE). HIGHS
TUE RANGE FROM THE MID-UPPER 40S ALONG/WEST OF I-95 TO THE MID-
UPPER 50S IN NE NC. SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. GFS/ECMWF IN GOOD AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE
FROM THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS
SOAR INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW
ON WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING
TSTMS ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO
BE MUCH IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL
CAPE) ON WED TO LEAD TO SEVERE WX. THIS WILL NEED TO BE MONITORED
FOR SUBSEQUENT CHANGES. HIGHS WED INTO THE MID-UPPER 60S TO AROUND
70 F (CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS
WED...SHIFTING OFF THE COAST LATER WED EVENING AS THE COLD FRONT
PUSHES THROUGH AND DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO
CHRISTMAS MORNING.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
MAINLY CLEAR SKIES PREVAIL OVER THE AREA EARLY THIS EVENING...WITH
SATELLITE IMAGERY INDICATING AN INCREASE IN HIGH CLOUDS SPREADING
NE INTO THE AREA AT 00Z. CEILINGS IN TO 5KFT TO 10KFT RANGE WILL
OVERSPREAD THE AREA AFTER 03Z. VFR CONDITIONS WILL PREVAIL THROUGH
EARLY MONDAY MORNING. LOW PRESSURE FORMING OFF THE SC COAST ALONG
WITH HIGH PRESSURE WEDGING SOUTH WILL CREATE A SETUP FOR A
COOL/RAINY PERIOD MONDAY MORNING THROUGH MONDAY NIGHT WITH MVFR/IFR
VIS/CIGS EXPECTED. AS THE LOW MOVES NORTH...OVER-RUNNING PRECIP
WILL TRACK S TO N MONDAY MORNING... EVENTUALLY REACHING EVERY AKQ
TAF SITE. MAY BE A VERY BRIEF PERIOD OF IP/FZRA AT KRIC...BUT NOT
CONFIDENT ENOUGH TO INCLUDE IN TAFS. HOWEVER...SOME IP/FZRA
POSSIBLE AT SMALLER AIRPORTS W/NW OF KRIC /E.G. KLKU/KFVX/ MONDAY
MORNING. EXPECT A BRIEF PERIOD OF 15-20 KT WIND GUSTS ALONG THE
COAST AS THE LOW MOVES NORTH AND THE PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT
PASSES THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER
THURSDAY AND FRIDAY. A PERIOD OF GUSTY WINDS EXPECTED WEDNESDAY
AFTERNOON THROUGH MIDDAY THURSDAY AHEAD OF AND BEHIND THE FRONT.

&&

.MARINE...
7 PM UPDATE...HAVE RAISED SCA...MAINLY FOR INCREASING
SEAS...ACROSS THE SRN COASTAL WATERS FROM 18Z MONDAY THROUGH 03Z
TUESDAY. OTHERWISE...VERY FEW CHANGES TO WINDS/SEAS IN THIS
UPDATE.

     AFTERNOON DISCUSSION...LO PRES REMAINS LOCKED IN PLACE OVR THE
NE STATES TNGT AS LO PRES DEVELOPS OFF THE SE CST. THE LO WILL
TRACK UP THE CAROLINA CST ON MON. DESPITE SOME WAA...WITH NE FLOW
AND A TIGHTENING PRES GRADIENT...THINK WINDS WILL MAKE IT INTO THE
15-20 KT RANGE FOR BOTH THE SRN BAY AND SOUND. THEREFORE DECIDED
TO HOIST A SCA FOR THESE LOCATIONS. THINK WINDS WILL BE QUITE
CLOSE TO SCA THRESHOLDS OVR THE NRN BAY AND OCEAN AS WELL...BUT
WITH MORE UNCERTAINTY THERE WILL HOLD OFF FOR NOW AND WILL ISSUE
HAZARD NEXT SHIFT IF NEC. SEAS WILL MAINLY BE 3-4 FT...WITH SOME
SEAS UP TO 5 FT PSBL OVR SRN CST WTRS MON EVENG. THE
AFOREMENTIONED LO WEAKENS ON TUE AS A STRONG COLD FRNT APPROACHES
FM THE W AND WINDS SLOWLY BCM SELY. SCA WINDS EXPECTED BY WED OVR
ALL WTRS EXCEPT THE RIVERS. THE FRNT CROSSES THE REGION WED NGT
INTO THU MORNG...WITH SCA CONDS CONTINUING POST FRNTAL INTO THU.
SEAS WILL BLD TO 5-8 FT WED INTO THU BEFORE SUBSIDING THU NGT.
WAVES OVR THE BAY WILL REACH 3-4 FT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM EARLY THIS MORNING TO NOON
     EST TODAY FOR VAZ048-049-060-061.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 10 PM EST THIS
     EVENING FOR ANZ632-634.
     SMALL CRAFT ADVISORY FROM 4 AM EARLY THIS MORNING TO 4 PM EST
     THIS AFTERNOON FOR ANZ633.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM EST
     THIS EVENING FOR ANZ658.

&&

$$
SYNOPSIS...ALB/LKB/MPR
NEAR TERM...ALB/LKB/MPR
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...DAP/WRS
MARINE...MAS/WRS






000
FXUS61 KAKQ 220606
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
106 AM EST MON DEC 22 2014

.SYNOPSIS...
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP
ALONG THE CAROLINA COAST TODAY THROUGH TUESDAY. A STRONG COLD
FRONT WILL CROSS THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS
BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH TODAY/...
ADJUSTED GRIDS A BIT BASED ON CRNT TRENDS FOR THE ERLY MORNING
UPDATE. MIN TEMPS HAVE BASICALY BEEN REACHED AND HAVE SHOWN SIGNS
OF RISING PAST FEW HRS SINCE THE CLOUDS HAVE MOVED IN. RAIN
COVERAGE QUICKLY EXPANDING AS IT MOVES NE ACROSS ERN NC AND INTO
SRN VA SO HAVE BUMPED UP THE POPS THRU 4 AM AND XPANDED THE RAIN
FARTHER NORTH. ALSO NOT THAT WRN PIEDMONT TEMPS ARE ABV FREEZING
(34 @ LKU...38 @ FVX)...HOWEVER WET BULB TMPS HOVERING ARND 32 SO
XPCT PCPN TO BE A RAIN/SLEET MIX AS IT BEGINS LATER ON. FREEZING
RAIN WILL LIKELY ADD TO THE MIX TOWARDS SUNRISE SO CRNT ADVSRY
REMAINS IN PLACE. TMPS STDY OR SLOWLY RISING FROM CRNT VALUES...
MAINLY IN THE 30S.

PVS DSCN:
WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTER
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTERNOON AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45
EAST TOWARD THE ERN SHORE & SERN CHES BAY...M40S-L50S NE NC.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AN UNSETTLED PERIOD...WITH STRONG SSW FLOW ALOFT AS AN AMPLIFIED
UPPER LEVEL TROUGH SLOWLY TRACKS EAST FROM THE PLAINS STATES MON
NIGHT...THROUGH THE MID ATLC AND SE STATES WED NIGHT. BULK OF LIFT
WILL PUSH OFF TO THE NE OF THE AREA MON NIGHT...BUT LOW LEVELS
REMAIN SATURATED SO WILL MAINTAIN A CHC FOR RAIN WITH AREAS OF
DRIZZLE AND FOG MENTIONED LATER MON NIGHT/TUE. GIVEN AN OVERRUNNING
PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE MON NIGHT THROUGH TUE
NIGHT...HAVE SIDED WITH THE COOLEST OF GUIDANCE FOR HIGH
TEMPERATURES TUE (CLOSEST TO THE ECWMF NUMERICAL GUIDANCE). HIGHS
TUE RANGE FROM THE MID-UPPER 40S ALONG/WEST OF I-95 TO THE MID-
UPPER 50S IN NE NC. SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. GFS/ECMWF IN GOOD AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE
FROM THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS
SOAR INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW
ON WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING
TSTMS ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO
BE MUCH IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL
CAPE) ON WED TO LEAD TO SEVERE WX. THIS WILL NEED TO BE MONITORED
FOR SUBSEQUENT CHANGES. HIGHS WED INTO THE MID-UPPER 60S TO AROUND
70 F (CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS
WED...SHIFTING OFF THE COAST LATER WED EVENING AS THE COLD FRONT
PUSHES THROUGH AND DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO
CHRISTMAS MORNING.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
MAINLY CLEAR SKIES PREVAIL OVER THE AREA EARLY THIS EVENING...WITH
SATELLITE IMAGERY INDICATING AN INCREASE IN HIGH CLOUDS SPREADING
NE INTO THE AREA AT 00Z. CEILINGS IN TO 5KFT TO 10KFT RANGE WILL
OVERSPREAD THE AREA AFTER 03Z. VFR CONDITIONS WILL PREVAIL THROUGH
EARLY MONDAY MORNING. LOW PRESSURE FORMING OFF THE SC COAST ALONG
WITH HIGH PRESSURE WEDGING SOUTH WILL CREATE A SETUP FOR A
COOL/RAINY PERIOD MONDAY MORNING THROUGH MONDAY NIGHT WITH MVFR/IFR
VIS/CIGS EXPECTED. AS THE LOW MOVES NORTH...OVER-RUNNING PRECIP
WILL TRACK S TO N MONDAY MORNING... EVENTUALLY REACHING EVERY AKQ
TAF SITE. MAY BE A VERY BRIEF PERIOD OF IP/FZRA AT KRIC...BUT NOT
CONFIDENT ENOUGH TO INCLUDE IN TAFS. HOWEVER...SOME IP/FZRA
POSSIBLE AT SMALLER AIRPORTS W/NW OF KRIC /E.G. KLKU/KFVX/ MONDAY
MORNING. EXPECT A BRIEF PERIOD OF 15-20 KT WIND GUSTS ALONG THE
COAST AS THE LOW MOVES NORTH AND THE PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT
PASSES THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER
THURSDAY AND FRIDAY. A PERIOD OF GUSTY WINDS EXPECTED WEDNESDAY
AFTERNOON THROUGH MIDDAY THURSDAY AHEAD OF AND BEHIND THE FRONT.

&&

.MARINE...
7 PM UPDATE...HAVE RAISED SCA...MAINLY FOR INCREASING
SEAS...ACROSS THE SRN COASTAL WATERS FROM 18Z MONDAY THROUGH 03Z
TUESDAY. OTHERWISE...VERY FEW CHANGES TO WINDS/SEAS IN THIS
UPDATE.

     AFTERNOON DISCUSSION...LO PRES REMAINS LOCKED IN PLACE OVR THE
NE STATES TNGT AS LO PRES DEVELOPS OFF THE SE CST. THE LO WILL
TRACK UP THE CAROLINA CST ON MON. DESPITE SOME WAA...WITH NE FLOW
AND A TIGHTENING PRES GRADIENT...THINK WINDS WILL MAKE IT INTO THE
15-20 KT RANGE FOR BOTH THE SRN BAY AND SOUND. THEREFORE DECIDED
TO HOIST A SCA FOR THESE LOCATIONS. THINK WINDS WILL BE QUITE
CLOSE TO SCA THRESHOLDS OVR THE NRN BAY AND OCEAN AS WELL...BUT
WITH MORE UNCERTAINTY THERE WILL HOLD OFF FOR NOW AND WILL ISSUE
HAZARD NEXT SHIFT IF NEC. SEAS WILL MAINLY BE 3-4 FT...WITH SOME
SEAS UP TO 5 FT PSBL OVR SRN CST WTRS MON EVENG. THE
AFOREMENTIONED LO WEAKENS ON TUE AS A STRONG COLD FRNT APPROACHES
FM THE W AND WINDS SLOWLY BCM SELY. SCA WINDS EXPECTED BY WED OVR
ALL WTRS EXCEPT THE RIVERS. THE FRNT CROSSES THE REGION WED NGT
INTO THU MORNG...WITH SCA CONDS CONTINUING POST FRNTAL INTO THU.
SEAS WILL BLD TO 5-8 FT WED INTO THU BEFORE SUBSIDING THU NGT.
WAVES OVR THE BAY WILL REACH 3-4 FT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM EARLY THIS MORNING TO NOON
     EST TODAY FOR VAZ048-049-060-061.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 10 PM EST THIS
     EVENING FOR ANZ632-634.
     SMALL CRAFT ADVISORY FROM 4 AM EARLY THIS MORNING TO 4 PM EST
     THIS AFTERNOON FOR ANZ633.
     SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 10 PM EST
     THIS EVENING FOR ANZ658.

&&

$$
SYNOPSIS...ALB/LKB/MPR
NEAR TERM...ALB/LKB/MPR
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...DAP/WRS
MARINE...MAS/WRS







000
FXUS61 KPBZ 220509
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1209 AM EST MON DEC 22 2014

.SYNOPSIS...
MIDWESTERN LOW PRESSURE WILL BRING WARMER TEMPERATURES AND RAIN TO
THE REGION FOR THE FIRST HALF OF THE WEEK. SNOW SHOWER CHANCES WILL
COME WITH THE PASSAGE OF THAT SYSTEMS COLD FRONT ON CHRISTMAS.

&&

.NEAR TERM /THROUGH MONDAY/...
CLDS ARE EXPD TO GRDLY INCR LT TNGT INTO MON IN WRM ADVCTN. A WK
SFC LOW ADVNG UP THE E COAST COULD BRING SOME PCPN AS FAR W AS
GARRETT AND TUCKER COUNTIES THIS AFTN...THOUGH EVE UPR AIR CHARTS
AND MESO ANALYSIS INDICATE MUCH IF NOT ALL OF THIS PCPN SHOULD RMN
E OF OUR AREA. IF PCPN DOES RCH THESE LOCATIONS...A BRF PD OF
FRZG RAIN IS PSBL AS TEMPS THERE RMN BLO FRZG IN COLD AIR DAMMING.
OUTSIDE OF THE HIGHER TERRAIN...TEMPS SHOULD RCH JUST ABV SEASONAL
LVLS TDA.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
UPPER TROUGH WILL AMPLIFY AND SLOWLY PIVOT EASTWARD DURING THIS TIME
FRAME...BECOMING MORE NEGATIVELY TILTED WITH THE HELP OF A
STRENGTHENING UPPER LEVEL JET BY LATE WEDNESDAY. EARLY ON...THERE
STILL REMAINS SOME UNCERTAINTY IN REGARD TO THE AMOUNT OF PRECIP
THAT WE WILL SEE ON TUESDAY...AS WE WILL BE PARKED IN BETWEEN THE
BETTER MOISTURE FROM THE WEAK COASTAL SYSTEM...AND THE DEEPENING
MOISTURE ASSOCIATED WITH THE COLD FRONT TO OUR WEST. IN
ADDITION...S-SE WIND SHOULD HELP PROVIDE SOME DOWNSLOPING AND DRYING
JUST EAST OF THE RIDGES IN PA/WV. WITH THIS IN MIND...OPTED TO STAY
WITH THE CHANCE POPS FOR THE DAY TUESDAY. WILL INCREASE POPS
OVERNIGHT AS THE LOW LEVEL JET STRENGTHS AND HELPS TO PULL MOISTURE
FROM THE GULF NORTHWARD. WITH THE NEARLY NORTHWARD PROGRESSION OF
THE DEVELOPING SURFACE LOW...BOTH THE ECMWF AND GFS SUGGEST THE BULK
OF THE HEAVIEST RAIN WILL STAY JUST WEST OF THE FORECAST AREA...WITH
THE BEST CHANCE FOR MODERATE RAIN TO BE AS THE COLD FRONT CROSSES
WEDNESDAY NIGHT. THIS SHOULD LIMIT ANY FLOOD THREAT FOR THE PERIOD.

STRONG WARM ADVECTION WILL BE ONGOING THROUGH THE ENTIRE TIME
PERIOD. EVEN WITH CLOUD COVER...HIGH TEMPERATURES ON BOTH TUESDAY
AND WEDNESDAY SHOULD BE WELL ABOVE SEASONAL VALUES WITH HIGHS
LIKELY TO REACH THE MID 50`S.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
CDFNT PASSAGE WILL INITIATE SNOW SHOWER CHANCES ON CHRISTMAS...BUT
LACK OF DEPTH TO THE COLD LYR...DRY ADVCTN IN THE MID LVLS ON THE
SRN PERIMETER OF NWD DIGGING UPR LOW...AND RAPIDLY ENSUING WARM
ADVCTN WL ENSURE A LACK OF SNOW COVER FOR CHRISTMAS.

THE RMNDR OF THE LONG TERM PD IS PROGGED TO FEATURE SEASONAL TEMPS
WITH A LATE WEEK COOLING TREND AS MDLS PROG A REAMPLIFYING FLOW
PTN WITH ERN CONUS TROFFG.

&&

.AVIATION /05Z MONDAY THROUGH FRIDAY/...
GENL IMPROVEMENT TO VFR FOR ALL TAF SITES CAN BE EXPECTED FOR THE
TAF PD AS SLY FLOW ALOFT INTENSIFIES OVR LINGER SFC HIGH PRES.

OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
MIDWRN LOW PRES WL SPREAD RAIN AND RESTRICTIONS OVR AREA PORTS ON
TUESDAY AND WEDNESDAY. IMPROVEMENTS ARE EXPECTED TO BE INITIATED
LTR ON THURSDAY WITH DRY SHRTWV RIDGING.

&&

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

&&

$$






000
FXUS61 KPBZ 220509
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1209 AM EST MON DEC 22 2014

.SYNOPSIS...
MIDWESTERN LOW PRESSURE WILL BRING WARMER TEMPERATURES AND RAIN TO
THE REGION FOR THE FIRST HALF OF THE WEEK. SNOW SHOWER CHANCES WILL
COME WITH THE PASSAGE OF THAT SYSTEMS COLD FRONT ON CHRISTMAS.

&&

.NEAR TERM /THROUGH MONDAY/...
CLDS ARE EXPD TO GRDLY INCR LT TNGT INTO MON IN WRM ADVCTN. A WK
SFC LOW ADVNG UP THE E COAST COULD BRING SOME PCPN AS FAR W AS
GARRETT AND TUCKER COUNTIES THIS AFTN...THOUGH EVE UPR AIR CHARTS
AND MESO ANALYSIS INDICATE MUCH IF NOT ALL OF THIS PCPN SHOULD RMN
E OF OUR AREA. IF PCPN DOES RCH THESE LOCATIONS...A BRF PD OF
FRZG RAIN IS PSBL AS TEMPS THERE RMN BLO FRZG IN COLD AIR DAMMING.
OUTSIDE OF THE HIGHER TERRAIN...TEMPS SHOULD RCH JUST ABV SEASONAL
LVLS TDA.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
UPPER TROUGH WILL AMPLIFY AND SLOWLY PIVOT EASTWARD DURING THIS TIME
FRAME...BECOMING MORE NEGATIVELY TILTED WITH THE HELP OF A
STRENGTHENING UPPER LEVEL JET BY LATE WEDNESDAY. EARLY ON...THERE
STILL REMAINS SOME UNCERTAINTY IN REGARD TO THE AMOUNT OF PRECIP
THAT WE WILL SEE ON TUESDAY...AS WE WILL BE PARKED IN BETWEEN THE
BETTER MOISTURE FROM THE WEAK COASTAL SYSTEM...AND THE DEEPENING
MOISTURE ASSOCIATED WITH THE COLD FRONT TO OUR WEST. IN
ADDITION...S-SE WIND SHOULD HELP PROVIDE SOME DOWNSLOPING AND DRYING
JUST EAST OF THE RIDGES IN PA/WV. WITH THIS IN MIND...OPTED TO STAY
WITH THE CHANCE POPS FOR THE DAY TUESDAY. WILL INCREASE POPS
OVERNIGHT AS THE LOW LEVEL JET STRENGTHS AND HELPS TO PULL MOISTURE
FROM THE GULF NORTHWARD. WITH THE NEARLY NORTHWARD PROGRESSION OF
THE DEVELOPING SURFACE LOW...BOTH THE ECMWF AND GFS SUGGEST THE BULK
OF THE HEAVIEST RAIN WILL STAY JUST WEST OF THE FORECAST AREA...WITH
THE BEST CHANCE FOR MODERATE RAIN TO BE AS THE COLD FRONT CROSSES
WEDNESDAY NIGHT. THIS SHOULD LIMIT ANY FLOOD THREAT FOR THE PERIOD.

STRONG WARM ADVECTION WILL BE ONGOING THROUGH THE ENTIRE TIME
PERIOD. EVEN WITH CLOUD COVER...HIGH TEMPERATURES ON BOTH TUESDAY
AND WEDNESDAY SHOULD BE WELL ABOVE SEASONAL VALUES WITH HIGHS
LIKELY TO REACH THE MID 50`S.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
CDFNT PASSAGE WILL INITIATE SNOW SHOWER CHANCES ON CHRISTMAS...BUT
LACK OF DEPTH TO THE COLD LYR...DRY ADVCTN IN THE MID LVLS ON THE
SRN PERIMETER OF NWD DIGGING UPR LOW...AND RAPIDLY ENSUING WARM
ADVCTN WL ENSURE A LACK OF SNOW COVER FOR CHRISTMAS.

THE RMNDR OF THE LONG TERM PD IS PROGGED TO FEATURE SEASONAL TEMPS
WITH A LATE WEEK COOLING TREND AS MDLS PROG A REAMPLIFYING FLOW
PTN WITH ERN CONUS TROFFG.

&&

.AVIATION /05Z MONDAY THROUGH FRIDAY/...
GENL IMPROVEMENT TO VFR FOR ALL TAF SITES CAN BE EXPECTED FOR THE
TAF PD AS SLY FLOW ALOFT INTENSIFIES OVR LINGER SFC HIGH PRES.

OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
MIDWRN LOW PRES WL SPREAD RAIN AND RESTRICTIONS OVR AREA PORTS ON
TUESDAY AND WEDNESDAY. IMPROVEMENTS ARE EXPECTED TO BE INITIATED
LTR ON THURSDAY WITH DRY SHRTWV RIDGING.

&&

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

&&

$$






000
FXUS61 KPBZ 220509
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1209 AM EST MON DEC 22 2014

.SYNOPSIS...
MIDWESTERN LOW PRESSURE WILL BRING WARMER TEMPERATURES AND RAIN TO
THE REGION FOR THE FIRST HALF OF THE WEEK. SNOW SHOWER CHANCES WILL
COME WITH THE PASSAGE OF THAT SYSTEMS COLD FRONT ON CHRISTMAS.

&&

.NEAR TERM /THROUGH MONDAY/...
CLDS ARE EXPD TO GRDLY INCR LT TNGT INTO MON IN WRM ADVCTN. A WK
SFC LOW ADVNG UP THE E COAST COULD BRING SOME PCPN AS FAR W AS
GARRETT AND TUCKER COUNTIES THIS AFTN...THOUGH EVE UPR AIR CHARTS
AND MESO ANALYSIS INDICATE MUCH IF NOT ALL OF THIS PCPN SHOULD RMN
E OF OUR AREA. IF PCPN DOES RCH THESE LOCATIONS...A BRF PD OF
FRZG RAIN IS PSBL AS TEMPS THERE RMN BLO FRZG IN COLD AIR DAMMING.
OUTSIDE OF THE HIGHER TERRAIN...TEMPS SHOULD RCH JUST ABV SEASONAL
LVLS TDA.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
UPPER TROUGH WILL AMPLIFY AND SLOWLY PIVOT EASTWARD DURING THIS TIME
FRAME...BECOMING MORE NEGATIVELY TILTED WITH THE HELP OF A
STRENGTHENING UPPER LEVEL JET BY LATE WEDNESDAY. EARLY ON...THERE
STILL REMAINS SOME UNCERTAINTY IN REGARD TO THE AMOUNT OF PRECIP
THAT WE WILL SEE ON TUESDAY...AS WE WILL BE PARKED IN BETWEEN THE
BETTER MOISTURE FROM THE WEAK COASTAL SYSTEM...AND THE DEEPENING
MOISTURE ASSOCIATED WITH THE COLD FRONT TO OUR WEST. IN
ADDITION...S-SE WIND SHOULD HELP PROVIDE SOME DOWNSLOPING AND DRYING
JUST EAST OF THE RIDGES IN PA/WV. WITH THIS IN MIND...OPTED TO STAY
WITH THE CHANCE POPS FOR THE DAY TUESDAY. WILL INCREASE POPS
OVERNIGHT AS THE LOW LEVEL JET STRENGTHS AND HELPS TO PULL MOISTURE
FROM THE GULF NORTHWARD. WITH THE NEARLY NORTHWARD PROGRESSION OF
THE DEVELOPING SURFACE LOW...BOTH THE ECMWF AND GFS SUGGEST THE BULK
OF THE HEAVIEST RAIN WILL STAY JUST WEST OF THE FORECAST AREA...WITH
THE BEST CHANCE FOR MODERATE RAIN TO BE AS THE COLD FRONT CROSSES
WEDNESDAY NIGHT. THIS SHOULD LIMIT ANY FLOOD THREAT FOR THE PERIOD.

STRONG WARM ADVECTION WILL BE ONGOING THROUGH THE ENTIRE TIME
PERIOD. EVEN WITH CLOUD COVER...HIGH TEMPERATURES ON BOTH TUESDAY
AND WEDNESDAY SHOULD BE WELL ABOVE SEASONAL VALUES WITH HIGHS
LIKELY TO REACH THE MID 50`S.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
CDFNT PASSAGE WILL INITIATE SNOW SHOWER CHANCES ON CHRISTMAS...BUT
LACK OF DEPTH TO THE COLD LYR...DRY ADVCTN IN THE MID LVLS ON THE
SRN PERIMETER OF NWD DIGGING UPR LOW...AND RAPIDLY ENSUING WARM
ADVCTN WL ENSURE A LACK OF SNOW COVER FOR CHRISTMAS.

THE RMNDR OF THE LONG TERM PD IS PROGGED TO FEATURE SEASONAL TEMPS
WITH A LATE WEEK COOLING TREND AS MDLS PROG A REAMPLIFYING FLOW
PTN WITH ERN CONUS TROFFG.

&&

.AVIATION /05Z MONDAY THROUGH FRIDAY/...
GENL IMPROVEMENT TO VFR FOR ALL TAF SITES CAN BE EXPECTED FOR THE
TAF PD AS SLY FLOW ALOFT INTENSIFIES OVR LINGER SFC HIGH PRES.

OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
MIDWRN LOW PRES WL SPREAD RAIN AND RESTRICTIONS OVR AREA PORTS ON
TUESDAY AND WEDNESDAY. IMPROVEMENTS ARE EXPECTED TO BE INITIATED
LTR ON THURSDAY WITH DRY SHRTWV RIDGING.

&&

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

&&

$$






000
FXUS61 KPBZ 220509
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1209 AM EST MON DEC 22 2014

.SYNOPSIS...
MIDWESTERN LOW PRESSURE WILL BRING WARMER TEMPERATURES AND RAIN TO
THE REGION FOR THE FIRST HALF OF THE WEEK. SNOW SHOWER CHANCES WILL
COME WITH THE PASSAGE OF THAT SYSTEMS COLD FRONT ON CHRISTMAS.

&&

.NEAR TERM /THROUGH MONDAY/...
CLDS ARE EXPD TO GRDLY INCR LT TNGT INTO MON IN WRM ADVCTN. A WK
SFC LOW ADVNG UP THE E COAST COULD BRING SOME PCPN AS FAR W AS
GARRETT AND TUCKER COUNTIES THIS AFTN...THOUGH EVE UPR AIR CHARTS
AND MESO ANALYSIS INDICATE MUCH IF NOT ALL OF THIS PCPN SHOULD RMN
E OF OUR AREA. IF PCPN DOES RCH THESE LOCATIONS...A BRF PD OF
FRZG RAIN IS PSBL AS TEMPS THERE RMN BLO FRZG IN COLD AIR DAMMING.
OUTSIDE OF THE HIGHER TERRAIN...TEMPS SHOULD RCH JUST ABV SEASONAL
LVLS TDA.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
UPPER TROUGH WILL AMPLIFY AND SLOWLY PIVOT EASTWARD DURING THIS TIME
FRAME...BECOMING MORE NEGATIVELY TILTED WITH THE HELP OF A
STRENGTHENING UPPER LEVEL JET BY LATE WEDNESDAY. EARLY ON...THERE
STILL REMAINS SOME UNCERTAINTY IN REGARD TO THE AMOUNT OF PRECIP
THAT WE WILL SEE ON TUESDAY...AS WE WILL BE PARKED IN BETWEEN THE
BETTER MOISTURE FROM THE WEAK COASTAL SYSTEM...AND THE DEEPENING
MOISTURE ASSOCIATED WITH THE COLD FRONT TO OUR WEST. IN
ADDITION...S-SE WIND SHOULD HELP PROVIDE SOME DOWNSLOPING AND DRYING
JUST EAST OF THE RIDGES IN PA/WV. WITH THIS IN MIND...OPTED TO STAY
WITH THE CHANCE POPS FOR THE DAY TUESDAY. WILL INCREASE POPS
OVERNIGHT AS THE LOW LEVEL JET STRENGTHS AND HELPS TO PULL MOISTURE
FROM THE GULF NORTHWARD. WITH THE NEARLY NORTHWARD PROGRESSION OF
THE DEVELOPING SURFACE LOW...BOTH THE ECMWF AND GFS SUGGEST THE BULK
OF THE HEAVIEST RAIN WILL STAY JUST WEST OF THE FORECAST AREA...WITH
THE BEST CHANCE FOR MODERATE RAIN TO BE AS THE COLD FRONT CROSSES
WEDNESDAY NIGHT. THIS SHOULD LIMIT ANY FLOOD THREAT FOR THE PERIOD.

STRONG WARM ADVECTION WILL BE ONGOING THROUGH THE ENTIRE TIME
PERIOD. EVEN WITH CLOUD COVER...HIGH TEMPERATURES ON BOTH TUESDAY
AND WEDNESDAY SHOULD BE WELL ABOVE SEASONAL VALUES WITH HIGHS
LIKELY TO REACH THE MID 50`S.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
CDFNT PASSAGE WILL INITIATE SNOW SHOWER CHANCES ON CHRISTMAS...BUT
LACK OF DEPTH TO THE COLD LYR...DRY ADVCTN IN THE MID LVLS ON THE
SRN PERIMETER OF NWD DIGGING UPR LOW...AND RAPIDLY ENSUING WARM
ADVCTN WL ENSURE A LACK OF SNOW COVER FOR CHRISTMAS.

THE RMNDR OF THE LONG TERM PD IS PROGGED TO FEATURE SEASONAL TEMPS
WITH A LATE WEEK COOLING TREND AS MDLS PROG A REAMPLIFYING FLOW
PTN WITH ERN CONUS TROFFG.

&&

.AVIATION /05Z MONDAY THROUGH FRIDAY/...
GENL IMPROVEMENT TO VFR FOR ALL TAF SITES CAN BE EXPECTED FOR THE
TAF PD AS SLY FLOW ALOFT INTENSIFIES OVR LINGER SFC HIGH PRES.

OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
MIDWRN LOW PRES WL SPREAD RAIN AND RESTRICTIONS OVR AREA PORTS ON
TUESDAY AND WEDNESDAY. IMPROVEMENTS ARE EXPECTED TO BE INITIATED
LTR ON THURSDAY WITH DRY SHRTWV RIDGING.

&&

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

&&

$$






000
FXUS61 KPHI 220237
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
937 PM EST SUN DEC 21 2014

.SYNOPSIS...
WEAK HIGH PRESSURE ACROSS THE REGION THIS EVENING WILL REMAIN
THROUGH MONDAY. WEAK LOW PRESSURE WILL MOVE NORTHWARD UP ALONG THE
EAST COAST MONDAY AFTERNOON THROUGH TUESDAY NIGHT. THIS LOW WILL BE
FOLLOWED BY ANOTHER STRONGER SYSTEM FOR WEDNESDAY AND WEDNESDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE END OF THE WEEK. A COLD
FRONT WILL CROSS THE AREA NEXT WEEKEND.

&&

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

FOR THE EVENING UPDATE, WITH THE CLEAR SKIES THIS EVENING ACROSS
THE SOUTH, WE`VE ADJUSTED TEMPS DOWN A FEW DEGREES ACROSS THE
DELMARVA. WE`VE ALSO ADJUSTED THE CLOUD COVER (LESS OF IT) DOWN
ACROSS THE AREA. THE EXPECTED HIGH LEVEL CLOUDS ARE STARTING TO
WORK THEIR WAY INTO THE REGION FROM THE SOUTHWEST.

WE`VE BEEN WATCHING THE STRATUS, SOUTH OF SUFFOLK COUNTY NY, SPIN
ALL AFTERNOON AND EVENING. BEFORE WE LOST DAYLIGHT, THE VISIBLE
SAT PIX SHOWED THIS FEATURE NICELY, EVEN DEPICTING A CENTER "EYE".
LOW RESOLUTION MODELS SHOW A WEAK TROF IN THIS AREA. HIGHER
RESOLUTION MODELS SHOW A WEAK LOW. RADAR IS ALSO PICKING UP THE
ROTATION.

THE FEATURE IS BRINGING A SOME PRECIPITATION TO LONG ISLAND AND
CONNECTICUT, AND WELL AS NORTHEAST NJ. THIS FEATURE IS MODELED TO
SLOWLY DRIFT SOUTHWEST TOWARD THE NJ COAST OVERNIGHT. THIS SHOULD
HELP TO PUSH THE LOWER STRATUS, WHICH MOVED NORTH TODAY, BACK
SOUTHWARD. IT SHOULD ALSO PUSH SOME FLURRIES OR SPRINKLES INTO OUR
NORTHEAST ZONES ADJACENT TO OKX. GRIDS HAVE BEEN UPDATED TO DEPICT
THIS.

PREVIOUS DISCUSSION...

THE CENTER OF A 1030 MB SURFACE HIGH OVER EASTERN CANADA WILL
CONTINUE TO RIDGE SOUTHWARD DOWN THE EASTERN SEABOARD THROUGH
TONIGHT. A MID- TO UPPER-LEVEL RIDGE AXIS WILL PROGRESS TOWARD THE
EAST COAST THIS EVENING.

SOME HI CLOUDS WILL SPILL INTO THE AREA OVERNIGHT AS THE RIDGE
SHIFTS DOWNSTREAM OF OUR AREA AND IS QUICKLY REPLACED BY A LEADING
SHORTWAVE TROUGH THAT IS EXPECTED TO MOVE IN FROM THE SOUTHWEST.

THE SOUTH TO NORTH LOW-LEVEL THERMAL GRADIENT ASSOCIATED WITH A WARM
FRONT IS FORECAST TO STRENGTHEN AS IT MOVES TOWARD SOUTHEAST VA LATE
TONIGHT. ISENTROPIC LIFT WILL DEVELOP ACROSS THE BOUNDARY AND EXPAND
NORTHWARD INTO THE DELMARVA BEFORE DAYBREAK. THE AIRMASS ON COLD
SIDE OF THIS BAROCLINIC ZONE WILL BE INITIALLY DRY SO EXPECT THE
THICKER LOW CLOUDS AND PRECIP TO REMAIN SOUTH OF DELAWARE AND THE
EASTERN SHORE OF MD TONIGHT.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
SOUTHERLY FLOW ALOFT AROUND THE BACKSIDE OF A WESTERN ATLANTIC RIDGE
AND AHEAD OF A TROUGH OVER THE NORTHERN PLAINS WILL BECOME
ESTABLISHED OVER THE EASTERN CONUS ON MONDAY. WAA DEVELOPS OVER THE
FORECAST AREA IN THIS PATTERN, ESPECIALLY IN THE LOW AND MID LEVELS.
AT THE SURFACE, HIGH PRESSURE IS FORECAST TO CONTINUE NOSING
SOUTHWARD DOWN THE EASTERN SIDE OF THE APPALACHIANS EVEN WITH THE
CENTER OF THE AFOREMENTIONED HIGH RETREATING TOWARD THE CANADIAN
MARITIMES. A CAD SETUP WILL KEEP THE COLDER AIR ANCHORED OVER OUR
REGION WITH A NORTHEASTERLY WIND NEAR THE SURFACE. THIS SHOULD
SUPPRESS THE ADVANCEMENT OF THE SURFACE WARM FRONT AS IT APPROACHES
FROM THE SOUTH ON MONDAY.

THE LATEST 12Z NAM CONTINUES TO BE QUICKER AND FARTHER NORTH WITH
THE DEVELOPMENT OF OVERRUNNING PRECIP COMPARED TO THE OTHER
OPERATIONAL MODELS. THE AIRMASS WILL BE VERY DRY INITIALLY, SO
PRECIP MAY NOT REACH THE GROUND AS QUICKLY AS THE NAM INDICATES.
HOWEVER, THERE APPEARS TO BE ENOUGH MOISTURE RETURN AND ISENTROPIC
LIFT FOR PRECIP TO EVENTUALLY OVERCOME THIS INITIAL DRY AIR,
ALLOWING THE PRECIP SHIELD TO EXPAND NORTHWARD THROUGH THE DAY.
CHANCE POPS FIRST ADVERTISED IN THE MORNING FOR THE DELMARVA, MIDDAY
FOR THE SOUTHERN PHILLY SUBURBS AND LATE AFTERNOON FOR THE I-80
CORRIDOR.

PTYPE WILL PREDOMINATELY BE RAIN ON MONDAY, BUT THERE COULD BE A
LIGHT WINTRY MIX (SNOW/SLEET) AWAY FROM THE COAST AT THE ONSET DUE
TO EVAPORATIONAL COOLING. THERE IS STILL NOT ENOUGH FORECAST
CERTAINTY TO PUBLISH A SNOWFALL MAP, BUT THE SETUP APPEARS LIMITED
FOR ANY ACCUMULATIONS EVEN IN THE HIGHER ELEVATIONS OF PA. WE
PREFERRED TO USE THE COOLER NAM/ECMWF FOR THERMAL PROFILES IN THIS
CAD SETUP TO DIAGNOSE POTENTIAL PTYPES AND FOR FORECASTING TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
UNSETTLED WEATHER WILL BE ACROSS THE REGION AT THE BEGINNING OF THE
LONG TERM. A H5 TROUGH WILL BE DEEPENING ACROSS THE MIDDLE PART OF
THE COUNTRY...AND ITS EFFECTS WILL BE FOR CLOUDS AND MOSTLY RAIN
BEGINNING MONDAY NIGHT AND PERSISTING INTO WEDNESDAY NIGHT AND
THURSDAY MORNING. THE FIRST BATCH OF RAIN WILL COME AS WEAK LOW
PRESSURE DEVELOPS ALONG THE CAROLINA COAST MONDAY AND MOVES
NORTHWARD ALONG THE NJ/DE COAST TUESDAY. WE HAVE CHC POPS N/W AND
LIKELY POPS S/E WITH THIS FEATURE. ON TUESDAY...THE HIGHER POPS MOVE
TO THE NORTHERN AREAS AS ONSHORE FLOW AND RESIDUAL MOISTURE FROM THE
LOW REMAIN ACROSS THE AREA.

THERE WILL NOT BE MUCH OF A BREAK IN THE WET PATTERN TUESDAY
NIGHT...ALTHOUGH SOME WEAK RIDGING WILL BE ACROSS THE AREA. ANOTHER
STRONGER LOW PRESSURE SYSTEM WILL BE DEVELOPING ACROSS THE SOUTHERN
STATES AND IT WILL MOVE NORTHWARD TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. THE LOW WILL TRACK TO THE WEST...RESULTING IN A SURGE OF
WARMER AIR ACROSS THE AREA. WE HAVE GONE ALONG WITH THE HIGH POPS
OFFERED BY WPC...WHICH ARE IN THE CATEGORICAL RANGE TUE NIGHT THRU
WED NIGHT.

A STRONG COLD FRONT WILL CROSS THE AREA OVERNIGHT WED NGT INTO THU.
IT APPEARS THAT MOST OF THE SHOWERS WILL BE DONE BY 12Z...BUT WE
HAVE LEFT IN A CHC FOR A FEW SHOWERS THU MORNING...IN CASE THE
SYSTEM SLOWS UP AT ALL. IT APPEARS THAT THE P-TYPE WILL STILL BE
RAIN...SINCE THE COLDER AIR WILL NOT ARRIVE FAST ENOUGH FOR A
CHANGEOVER.

THE REST OF THE EXTENDED PERIOD WILL FEATURE DRIER WEATHER AS A SFC
HIGH EXTENDS ACROSS THE AREA. THE H5 TROUGH WILL STILL BE TO THE
WEST...SO TEMPERATURES WILL REMAIN ABOVE NORMAL BOTH FRI AND SAT.
ANOTHER LOW AND DEVELOPING FRONT MAY BEGIN TO AFFECT THE AREA SAT
NIGHT INTO NEXT SUNDAY...LOW CHC POPS ARE IN THE GRIDS FOR THIS.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THE STRATUS THAT MOVED NORTH TODAY IS DRIFTIN BACK DOWN SOUTH
AGAIN. THE LOW CLOUDS ARE THROUGH TRENTON, HAVE JUST MOVED OVER
KPNE, AND IS HEADING TOWARD KPHL. WILL UPDATE THE TERMINALS TO REFLECT.

PREVIOUS DISCUSSION...

LEFTOVER OVC STRATOCU CONTINUES TO ERODE LATE THIS AFTN OVER MOST OF
THE TERMINALS. AT 20Z, TTN AND RDG LIE ON THE EDGE OF THESE CLOUDS,
WHICH ARE YIELDING MVFR CIGS BETWEEN 2500 AND 3000 FT. EXPECT THE
CLOUDS TO CLEAR OUT AT THESE TWO TERMINALS BY SUNSET AT THE LATEST.

VFR THIS EVE. VFR ANTICIPATED FOR MOST TERMINALS OVERNIGHT AND
MONDAY MORNING THOUGH THE 12Z NAM DEVELOPS STRATUS FROM PHL NORTH
AND EAST, RESULTING IN MVFR AND EVEN IFR CIGS BETWEEN BETWEEN
09-15Z. THIS MAY BE A BIT OVERDONE, BUT WILL STILL NEED TO MONITOR
THE POTENTIAL AS THE MARINE LAYER TRIES TO BECOME ESTABLISHED IN
CONCERT WITH A LIGHT NORTHEAST WIND IN THE BOUNDARY LAYER.
OTHERWISE, MID CLOUDS WILL QUICKLY OVERSPREAD THE AREA FROM
SOUTHWEST TO NORTHEAST IN THE MORNING. RAIN IS ALSO FORECAST TO
DEVELOP IN VICINITY OF ILG/MIV DURING THE MID TO LATE MORNING,
PHL/PNE/RDG DURING THE EARLY TO MID AFTERNOON AND ABE/TTN LATE IN
THE DAY.

OUTLOOK...

MON NIGHT THRU TUE...MOSTLY VFR. INCREASING CLOUDS LATE TUE NIGHT.
TUE NIGHT THRU THU MORNING...OCNL LOW CIGS/VSBYS IN RAIN AND FOG.
THU AFTERNOON THRU FRIDAY...MOSTLY VFR. GUSTY WEST/NORTHWEST WINDS.

&&

.MARINE...
LIGHT NORTHWEST WINDS 5-15 KT THIS AFTERNOON WILL BECOME NORTHERLY
TONIGHT AND NORTHEASTERLY ON MONDAY. SEAS GENERALLY 1-2 FT DURING
THIS TIME.

OUTLOOK...
MON NIGHT...SUB SCA CONDITIONS.
TUE/TUE NGT...SCA CONDITIONS ON THE OCEAN..SUB-SCA OVER DEL BAY.
WED THRU FRI...SCA CONDITIONS WITH LOW END GALE GUSTS WED NGT AND THU.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...O`HARA
NEAR TERM...KLEIN
SHORT TERM...KLEIN
LONG TERM...O`HARA
AVIATION...KLEIN/O`HARA
MARINE...KLEIN/O`HARA







000
FXUS61 KPHI 220237
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
937 PM EST SUN DEC 21 2014

.SYNOPSIS...
WEAK HIGH PRESSURE ACROSS THE REGION THIS EVENING WILL REMAIN
THROUGH MONDAY. WEAK LOW PRESSURE WILL MOVE NORTHWARD UP ALONG THE
EAST COAST MONDAY AFTERNOON THROUGH TUESDAY NIGHT. THIS LOW WILL BE
FOLLOWED BY ANOTHER STRONGER SYSTEM FOR WEDNESDAY AND WEDNESDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE END OF THE WEEK. A COLD
FRONT WILL CROSS THE AREA NEXT WEEKEND.

&&

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

FOR THE EVENING UPDATE, WITH THE CLEAR SKIES THIS EVENING ACROSS
THE SOUTH, WE`VE ADJUSTED TEMPS DOWN A FEW DEGREES ACROSS THE
DELMARVA. WE`VE ALSO ADJUSTED THE CLOUD COVER (LESS OF IT) DOWN
ACROSS THE AREA. THE EXPECTED HIGH LEVEL CLOUDS ARE STARTING TO
WORK THEIR WAY INTO THE REGION FROM THE SOUTHWEST.

WE`VE BEEN WATCHING THE STRATUS, SOUTH OF SUFFOLK COUNTY NY, SPIN
ALL AFTERNOON AND EVENING. BEFORE WE LOST DAYLIGHT, THE VISIBLE
SAT PIX SHOWED THIS FEATURE NICELY, EVEN DEPICTING A CENTER "EYE".
LOW RESOLUTION MODELS SHOW A WEAK TROF IN THIS AREA. HIGHER
RESOLUTION MODELS SHOW A WEAK LOW. RADAR IS ALSO PICKING UP THE
ROTATION.

THE FEATURE IS BRINGING A SOME PRECIPITATION TO LONG ISLAND AND
CONNECTICUT, AND WELL AS NORTHEAST NJ. THIS FEATURE IS MODELED TO
SLOWLY DRIFT SOUTHWEST TOWARD THE NJ COAST OVERNIGHT. THIS SHOULD
HELP TO PUSH THE LOWER STRATUS, WHICH MOVED NORTH TODAY, BACK
SOUTHWARD. IT SHOULD ALSO PUSH SOME FLURRIES OR SPRINKLES INTO OUR
NORTHEAST ZONES ADJACENT TO OKX. GRIDS HAVE BEEN UPDATED TO DEPICT
THIS.

PREVIOUS DISCUSSION...

THE CENTER OF A 1030 MB SURFACE HIGH OVER EASTERN CANADA WILL
CONTINUE TO RIDGE SOUTHWARD DOWN THE EASTERN SEABOARD THROUGH
TONIGHT. A MID- TO UPPER-LEVEL RIDGE AXIS WILL PROGRESS TOWARD THE
EAST COAST THIS EVENING.

SOME HI CLOUDS WILL SPILL INTO THE AREA OVERNIGHT AS THE RIDGE
SHIFTS DOWNSTREAM OF OUR AREA AND IS QUICKLY REPLACED BY A LEADING
SHORTWAVE TROUGH THAT IS EXPECTED TO MOVE IN FROM THE SOUTHWEST.

THE SOUTH TO NORTH LOW-LEVEL THERMAL GRADIENT ASSOCIATED WITH A WARM
FRONT IS FORECAST TO STRENGTHEN AS IT MOVES TOWARD SOUTHEAST VA LATE
TONIGHT. ISENTROPIC LIFT WILL DEVELOP ACROSS THE BOUNDARY AND EXPAND
NORTHWARD INTO THE DELMARVA BEFORE DAYBREAK. THE AIRMASS ON COLD
SIDE OF THIS BAROCLINIC ZONE WILL BE INITIALLY DRY SO EXPECT THE
THICKER LOW CLOUDS AND PRECIP TO REMAIN SOUTH OF DELAWARE AND THE
EASTERN SHORE OF MD TONIGHT.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
SOUTHERLY FLOW ALOFT AROUND THE BACKSIDE OF A WESTERN ATLANTIC RIDGE
AND AHEAD OF A TROUGH OVER THE NORTHERN PLAINS WILL BECOME
ESTABLISHED OVER THE EASTERN CONUS ON MONDAY. WAA DEVELOPS OVER THE
FORECAST AREA IN THIS PATTERN, ESPECIALLY IN THE LOW AND MID LEVELS.
AT THE SURFACE, HIGH PRESSURE IS FORECAST TO CONTINUE NOSING
SOUTHWARD DOWN THE EASTERN SIDE OF THE APPALACHIANS EVEN WITH THE
CENTER OF THE AFOREMENTIONED HIGH RETREATING TOWARD THE CANADIAN
MARITIMES. A CAD SETUP WILL KEEP THE COLDER AIR ANCHORED OVER OUR
REGION WITH A NORTHEASTERLY WIND NEAR THE SURFACE. THIS SHOULD
SUPPRESS THE ADVANCEMENT OF THE SURFACE WARM FRONT AS IT APPROACHES
FROM THE SOUTH ON MONDAY.

THE LATEST 12Z NAM CONTINUES TO BE QUICKER AND FARTHER NORTH WITH
THE DEVELOPMENT OF OVERRUNNING PRECIP COMPARED TO THE OTHER
OPERATIONAL MODELS. THE AIRMASS WILL BE VERY DRY INITIALLY, SO
PRECIP MAY NOT REACH THE GROUND AS QUICKLY AS THE NAM INDICATES.
HOWEVER, THERE APPEARS TO BE ENOUGH MOISTURE RETURN AND ISENTROPIC
LIFT FOR PRECIP TO EVENTUALLY OVERCOME THIS INITIAL DRY AIR,
ALLOWING THE PRECIP SHIELD TO EXPAND NORTHWARD THROUGH THE DAY.
CHANCE POPS FIRST ADVERTISED IN THE MORNING FOR THE DELMARVA, MIDDAY
FOR THE SOUTHERN PHILLY SUBURBS AND LATE AFTERNOON FOR THE I-80
CORRIDOR.

PTYPE WILL PREDOMINATELY BE RAIN ON MONDAY, BUT THERE COULD BE A
LIGHT WINTRY MIX (SNOW/SLEET) AWAY FROM THE COAST AT THE ONSET DUE
TO EVAPORATIONAL COOLING. THERE IS STILL NOT ENOUGH FORECAST
CERTAINTY TO PUBLISH A SNOWFALL MAP, BUT THE SETUP APPEARS LIMITED
FOR ANY ACCUMULATIONS EVEN IN THE HIGHER ELEVATIONS OF PA. WE
PREFERRED TO USE THE COOLER NAM/ECMWF FOR THERMAL PROFILES IN THIS
CAD SETUP TO DIAGNOSE POTENTIAL PTYPES AND FOR FORECASTING TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
UNSETTLED WEATHER WILL BE ACROSS THE REGION AT THE BEGINNING OF THE
LONG TERM. A H5 TROUGH WILL BE DEEPENING ACROSS THE MIDDLE PART OF
THE COUNTRY...AND ITS EFFECTS WILL BE FOR CLOUDS AND MOSTLY RAIN
BEGINNING MONDAY NIGHT AND PERSISTING INTO WEDNESDAY NIGHT AND
THURSDAY MORNING. THE FIRST BATCH OF RAIN WILL COME AS WEAK LOW
PRESSURE DEVELOPS ALONG THE CAROLINA COAST MONDAY AND MOVES
NORTHWARD ALONG THE NJ/DE COAST TUESDAY. WE HAVE CHC POPS N/W AND
LIKELY POPS S/E WITH THIS FEATURE. ON TUESDAY...THE HIGHER POPS MOVE
TO THE NORTHERN AREAS AS ONSHORE FLOW AND RESIDUAL MOISTURE FROM THE
LOW REMAIN ACROSS THE AREA.

THERE WILL NOT BE MUCH OF A BREAK IN THE WET PATTERN TUESDAY
NIGHT...ALTHOUGH SOME WEAK RIDGING WILL BE ACROSS THE AREA. ANOTHER
STRONGER LOW PRESSURE SYSTEM WILL BE DEVELOPING ACROSS THE SOUTHERN
STATES AND IT WILL MOVE NORTHWARD TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. THE LOW WILL TRACK TO THE WEST...RESULTING IN A SURGE OF
WARMER AIR ACROSS THE AREA. WE HAVE GONE ALONG WITH THE HIGH POPS
OFFERED BY WPC...WHICH ARE IN THE CATEGORICAL RANGE TUE NIGHT THRU
WED NIGHT.

A STRONG COLD FRONT WILL CROSS THE AREA OVERNIGHT WED NGT INTO THU.
IT APPEARS THAT MOST OF THE SHOWERS WILL BE DONE BY 12Z...BUT WE
HAVE LEFT IN A CHC FOR A FEW SHOWERS THU MORNING...IN CASE THE
SYSTEM SLOWS UP AT ALL. IT APPEARS THAT THE P-TYPE WILL STILL BE
RAIN...SINCE THE COLDER AIR WILL NOT ARRIVE FAST ENOUGH FOR A
CHANGEOVER.

THE REST OF THE EXTENDED PERIOD WILL FEATURE DRIER WEATHER AS A SFC
HIGH EXTENDS ACROSS THE AREA. THE H5 TROUGH WILL STILL BE TO THE
WEST...SO TEMPERATURES WILL REMAIN ABOVE NORMAL BOTH FRI AND SAT.
ANOTHER LOW AND DEVELOPING FRONT MAY BEGIN TO AFFECT THE AREA SAT
NIGHT INTO NEXT SUNDAY...LOW CHC POPS ARE IN THE GRIDS FOR THIS.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THE STRATUS THAT MOVED NORTH TODAY IS DRIFTIN BACK DOWN SOUTH
AGAIN. THE LOW CLOUDS ARE THROUGH TRENTON, HAVE JUST MOVED OVER
KPNE, AND IS HEADING TOWARD KPHL. WILL UPDATE THE TERMINALS TO REFLECT.

PREVIOUS DISCUSSION...

LEFTOVER OVC STRATOCU CONTINUES TO ERODE LATE THIS AFTN OVER MOST OF
THE TERMINALS. AT 20Z, TTN AND RDG LIE ON THE EDGE OF THESE CLOUDS,
WHICH ARE YIELDING MVFR CIGS BETWEEN 2500 AND 3000 FT. EXPECT THE
CLOUDS TO CLEAR OUT AT THESE TWO TERMINALS BY SUNSET AT THE LATEST.

VFR THIS EVE. VFR ANTICIPATED FOR MOST TERMINALS OVERNIGHT AND
MONDAY MORNING THOUGH THE 12Z NAM DEVELOPS STRATUS FROM PHL NORTH
AND EAST, RESULTING IN MVFR AND EVEN IFR CIGS BETWEEN BETWEEN
09-15Z. THIS MAY BE A BIT OVERDONE, BUT WILL STILL NEED TO MONITOR
THE POTENTIAL AS THE MARINE LAYER TRIES TO BECOME ESTABLISHED IN
CONCERT WITH A LIGHT NORTHEAST WIND IN THE BOUNDARY LAYER.
OTHERWISE, MID CLOUDS WILL QUICKLY OVERSPREAD THE AREA FROM
SOUTHWEST TO NORTHEAST IN THE MORNING. RAIN IS ALSO FORECAST TO
DEVELOP IN VICINITY OF ILG/MIV DURING THE MID TO LATE MORNING,
PHL/PNE/RDG DURING THE EARLY TO MID AFTERNOON AND ABE/TTN LATE IN
THE DAY.

OUTLOOK...

MON NIGHT THRU TUE...MOSTLY VFR. INCREASING CLOUDS LATE TUE NIGHT.
TUE NIGHT THRU THU MORNING...OCNL LOW CIGS/VSBYS IN RAIN AND FOG.
THU AFTERNOON THRU FRIDAY...MOSTLY VFR. GUSTY WEST/NORTHWEST WINDS.

&&

.MARINE...
LIGHT NORTHWEST WINDS 5-15 KT THIS AFTERNOON WILL BECOME NORTHERLY
TONIGHT AND NORTHEASTERLY ON MONDAY. SEAS GENERALLY 1-2 FT DURING
THIS TIME.

OUTLOOK...
MON NIGHT...SUB SCA CONDITIONS.
TUE/TUE NGT...SCA CONDITIONS ON THE OCEAN..SUB-SCA OVER DEL BAY.
WED THRU FRI...SCA CONDITIONS WITH LOW END GALE GUSTS WED NGT AND THU.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...O`HARA
NEAR TERM...KLEIN
SHORT TERM...KLEIN
LONG TERM...O`HARA
AVIATION...KLEIN/O`HARA
MARINE...KLEIN/O`HARA







000
FXUS61 KPHI 220237
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
937 PM EST SUN DEC 21 2014

.SYNOPSIS...
WEAK HIGH PRESSURE ACROSS THE REGION THIS EVENING WILL REMAIN
THROUGH MONDAY. WEAK LOW PRESSURE WILL MOVE NORTHWARD UP ALONG THE
EAST COAST MONDAY AFTERNOON THROUGH TUESDAY NIGHT. THIS LOW WILL BE
FOLLOWED BY ANOTHER STRONGER SYSTEM FOR WEDNESDAY AND WEDNESDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE END OF THE WEEK. A COLD
FRONT WILL CROSS THE AREA NEXT WEEKEND.

&&

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

FOR THE EVENING UPDATE, WITH THE CLEAR SKIES THIS EVENING ACROSS
THE SOUTH, WE`VE ADJUSTED TEMPS DOWN A FEW DEGREES ACROSS THE
DELMARVA. WE`VE ALSO ADJUSTED THE CLOUD COVER (LESS OF IT) DOWN
ACROSS THE AREA. THE EXPECTED HIGH LEVEL CLOUDS ARE STARTING TO
WORK THEIR WAY INTO THE REGION FROM THE SOUTHWEST.

WE`VE BEEN WATCHING THE STRATUS, SOUTH OF SUFFOLK COUNTY NY, SPIN
ALL AFTERNOON AND EVENING. BEFORE WE LOST DAYLIGHT, THE VISIBLE
SAT PIX SHOWED THIS FEATURE NICELY, EVEN DEPICTING A CENTER "EYE".
LOW RESOLUTION MODELS SHOW A WEAK TROF IN THIS AREA. HIGHER
RESOLUTION MODELS SHOW A WEAK LOW. RADAR IS ALSO PICKING UP THE
ROTATION.

THE FEATURE IS BRINGING A SOME PRECIPITATION TO LONG ISLAND AND
CONNECTICUT, AND WELL AS NORTHEAST NJ. THIS FEATURE IS MODELED TO
SLOWLY DRIFT SOUTHWEST TOWARD THE NJ COAST OVERNIGHT. THIS SHOULD
HELP TO PUSH THE LOWER STRATUS, WHICH MOVED NORTH TODAY, BACK
SOUTHWARD. IT SHOULD ALSO PUSH SOME FLURRIES OR SPRINKLES INTO OUR
NORTHEAST ZONES ADJACENT TO OKX. GRIDS HAVE BEEN UPDATED TO DEPICT
THIS.

PREVIOUS DISCUSSION...

THE CENTER OF A 1030 MB SURFACE HIGH OVER EASTERN CANADA WILL
CONTINUE TO RIDGE SOUTHWARD DOWN THE EASTERN SEABOARD THROUGH
TONIGHT. A MID- TO UPPER-LEVEL RIDGE AXIS WILL PROGRESS TOWARD THE
EAST COAST THIS EVENING.

SOME HI CLOUDS WILL SPILL INTO THE AREA OVERNIGHT AS THE RIDGE
SHIFTS DOWNSTREAM OF OUR AREA AND IS QUICKLY REPLACED BY A LEADING
SHORTWAVE TROUGH THAT IS EXPECTED TO MOVE IN FROM THE SOUTHWEST.

THE SOUTH TO NORTH LOW-LEVEL THERMAL GRADIENT ASSOCIATED WITH A WARM
FRONT IS FORECAST TO STRENGTHEN AS IT MOVES TOWARD SOUTHEAST VA LATE
TONIGHT. ISENTROPIC LIFT WILL DEVELOP ACROSS THE BOUNDARY AND EXPAND
NORTHWARD INTO THE DELMARVA BEFORE DAYBREAK. THE AIRMASS ON COLD
SIDE OF THIS BAROCLINIC ZONE WILL BE INITIALLY DRY SO EXPECT THE
THICKER LOW CLOUDS AND PRECIP TO REMAIN SOUTH OF DELAWARE AND THE
EASTERN SHORE OF MD TONIGHT.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
SOUTHERLY FLOW ALOFT AROUND THE BACKSIDE OF A WESTERN ATLANTIC RIDGE
AND AHEAD OF A TROUGH OVER THE NORTHERN PLAINS WILL BECOME
ESTABLISHED OVER THE EASTERN CONUS ON MONDAY. WAA DEVELOPS OVER THE
FORECAST AREA IN THIS PATTERN, ESPECIALLY IN THE LOW AND MID LEVELS.
AT THE SURFACE, HIGH PRESSURE IS FORECAST TO CONTINUE NOSING
SOUTHWARD DOWN THE EASTERN SIDE OF THE APPALACHIANS EVEN WITH THE
CENTER OF THE AFOREMENTIONED HIGH RETREATING TOWARD THE CANADIAN
MARITIMES. A CAD SETUP WILL KEEP THE COLDER AIR ANCHORED OVER OUR
REGION WITH A NORTHEASTERLY WIND NEAR THE SURFACE. THIS SHOULD
SUPPRESS THE ADVANCEMENT OF THE SURFACE WARM FRONT AS IT APPROACHES
FROM THE SOUTH ON MONDAY.

THE LATEST 12Z NAM CONTINUES TO BE QUICKER AND FARTHER NORTH WITH
THE DEVELOPMENT OF OVERRUNNING PRECIP COMPARED TO THE OTHER
OPERATIONAL MODELS. THE AIRMASS WILL BE VERY DRY INITIALLY, SO
PRECIP MAY NOT REACH THE GROUND AS QUICKLY AS THE NAM INDICATES.
HOWEVER, THERE APPEARS TO BE ENOUGH MOISTURE RETURN AND ISENTROPIC
LIFT FOR PRECIP TO EVENTUALLY OVERCOME THIS INITIAL DRY AIR,
ALLOWING THE PRECIP SHIELD TO EXPAND NORTHWARD THROUGH THE DAY.
CHANCE POPS FIRST ADVERTISED IN THE MORNING FOR THE DELMARVA, MIDDAY
FOR THE SOUTHERN PHILLY SUBURBS AND LATE AFTERNOON FOR THE I-80
CORRIDOR.

PTYPE WILL PREDOMINATELY BE RAIN ON MONDAY, BUT THERE COULD BE A
LIGHT WINTRY MIX (SNOW/SLEET) AWAY FROM THE COAST AT THE ONSET DUE
TO EVAPORATIONAL COOLING. THERE IS STILL NOT ENOUGH FORECAST
CERTAINTY TO PUBLISH A SNOWFALL MAP, BUT THE SETUP APPEARS LIMITED
FOR ANY ACCUMULATIONS EVEN IN THE HIGHER ELEVATIONS OF PA. WE
PREFERRED TO USE THE COOLER NAM/ECMWF FOR THERMAL PROFILES IN THIS
CAD SETUP TO DIAGNOSE POTENTIAL PTYPES AND FOR FORECASTING TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
UNSETTLED WEATHER WILL BE ACROSS THE REGION AT THE BEGINNING OF THE
LONG TERM. A H5 TROUGH WILL BE DEEPENING ACROSS THE MIDDLE PART OF
THE COUNTRY...AND ITS EFFECTS WILL BE FOR CLOUDS AND MOSTLY RAIN
BEGINNING MONDAY NIGHT AND PERSISTING INTO WEDNESDAY NIGHT AND
THURSDAY MORNING. THE FIRST BATCH OF RAIN WILL COME AS WEAK LOW
PRESSURE DEVELOPS ALONG THE CAROLINA COAST MONDAY AND MOVES
NORTHWARD ALONG THE NJ/DE COAST TUESDAY. WE HAVE CHC POPS N/W AND
LIKELY POPS S/E WITH THIS FEATURE. ON TUESDAY...THE HIGHER POPS MOVE
TO THE NORTHERN AREAS AS ONSHORE FLOW AND RESIDUAL MOISTURE FROM THE
LOW REMAIN ACROSS THE AREA.

THERE WILL NOT BE MUCH OF A BREAK IN THE WET PATTERN TUESDAY
NIGHT...ALTHOUGH SOME WEAK RIDGING WILL BE ACROSS THE AREA. ANOTHER
STRONGER LOW PRESSURE SYSTEM WILL BE DEVELOPING ACROSS THE SOUTHERN
STATES AND IT WILL MOVE NORTHWARD TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. THE LOW WILL TRACK TO THE WEST...RESULTING IN A SURGE OF
WARMER AIR ACROSS THE AREA. WE HAVE GONE ALONG WITH THE HIGH POPS
OFFERED BY WPC...WHICH ARE IN THE CATEGORICAL RANGE TUE NIGHT THRU
WED NIGHT.

A STRONG COLD FRONT WILL CROSS THE AREA OVERNIGHT WED NGT INTO THU.
IT APPEARS THAT MOST OF THE SHOWERS WILL BE DONE BY 12Z...BUT WE
HAVE LEFT IN A CHC FOR A FEW SHOWERS THU MORNING...IN CASE THE
SYSTEM SLOWS UP AT ALL. IT APPEARS THAT THE P-TYPE WILL STILL BE
RAIN...SINCE THE COLDER AIR WILL NOT ARRIVE FAST ENOUGH FOR A
CHANGEOVER.

THE REST OF THE EXTENDED PERIOD WILL FEATURE DRIER WEATHER AS A SFC
HIGH EXTENDS ACROSS THE AREA. THE H5 TROUGH WILL STILL BE TO THE
WEST...SO TEMPERATURES WILL REMAIN ABOVE NORMAL BOTH FRI AND SAT.
ANOTHER LOW AND DEVELOPING FRONT MAY BEGIN TO AFFECT THE AREA SAT
NIGHT INTO NEXT SUNDAY...LOW CHC POPS ARE IN THE GRIDS FOR THIS.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THE STRATUS THAT MOVED NORTH TODAY IS DRIFTIN BACK DOWN SOUTH
AGAIN. THE LOW CLOUDS ARE THROUGH TRENTON, HAVE JUST MOVED OVER
KPNE, AND IS HEADING TOWARD KPHL. WILL UPDATE THE TERMINALS TO REFLECT.

PREVIOUS DISCUSSION...

LEFTOVER OVC STRATOCU CONTINUES TO ERODE LATE THIS AFTN OVER MOST OF
THE TERMINALS. AT 20Z, TTN AND RDG LIE ON THE EDGE OF THESE CLOUDS,
WHICH ARE YIELDING MVFR CIGS BETWEEN 2500 AND 3000 FT. EXPECT THE
CLOUDS TO CLEAR OUT AT THESE TWO TERMINALS BY SUNSET AT THE LATEST.

VFR THIS EVE. VFR ANTICIPATED FOR MOST TERMINALS OVERNIGHT AND
MONDAY MORNING THOUGH THE 12Z NAM DEVELOPS STRATUS FROM PHL NORTH
AND EAST, RESULTING IN MVFR AND EVEN IFR CIGS BETWEEN BETWEEN
09-15Z. THIS MAY BE A BIT OVERDONE, BUT WILL STILL NEED TO MONITOR
THE POTENTIAL AS THE MARINE LAYER TRIES TO BECOME ESTABLISHED IN
CONCERT WITH A LIGHT NORTHEAST WIND IN THE BOUNDARY LAYER.
OTHERWISE, MID CLOUDS WILL QUICKLY OVERSPREAD THE AREA FROM
SOUTHWEST TO NORTHEAST IN THE MORNING. RAIN IS ALSO FORECAST TO
DEVELOP IN VICINITY OF ILG/MIV DURING THE MID TO LATE MORNING,
PHL/PNE/RDG DURING THE EARLY TO MID AFTERNOON AND ABE/TTN LATE IN
THE DAY.

OUTLOOK...

MON NIGHT THRU TUE...MOSTLY VFR. INCREASING CLOUDS LATE TUE NIGHT.
TUE NIGHT THRU THU MORNING...OCNL LOW CIGS/VSBYS IN RAIN AND FOG.
THU AFTERNOON THRU FRIDAY...MOSTLY VFR. GUSTY WEST/NORTHWEST WINDS.

&&

.MARINE...
LIGHT NORTHWEST WINDS 5-15 KT THIS AFTERNOON WILL BECOME NORTHERLY
TONIGHT AND NORTHEASTERLY ON MONDAY. SEAS GENERALLY 1-2 FT DURING
THIS TIME.

OUTLOOK...
MON NIGHT...SUB SCA CONDITIONS.
TUE/TUE NGT...SCA CONDITIONS ON THE OCEAN..SUB-SCA OVER DEL BAY.
WED THRU FRI...SCA CONDITIONS WITH LOW END GALE GUSTS WED NGT AND THU.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...O`HARA
NEAR TERM...KLEIN
SHORT TERM...KLEIN
LONG TERM...O`HARA
AVIATION...KLEIN/O`HARA
MARINE...KLEIN/O`HARA







000
FXUS61 KPHI 220237
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
937 PM EST SUN DEC 21 2014

.SYNOPSIS...
WEAK HIGH PRESSURE ACROSS THE REGION THIS EVENING WILL REMAIN
THROUGH MONDAY. WEAK LOW PRESSURE WILL MOVE NORTHWARD UP ALONG THE
EAST COAST MONDAY AFTERNOON THROUGH TUESDAY NIGHT. THIS LOW WILL BE
FOLLOWED BY ANOTHER STRONGER SYSTEM FOR WEDNESDAY AND WEDNESDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE END OF THE WEEK. A COLD
FRONT WILL CROSS THE AREA NEXT WEEKEND.

&&

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

FOR THE EVENING UPDATE, WITH THE CLEAR SKIES THIS EVENING ACROSS
THE SOUTH, WE`VE ADJUSTED TEMPS DOWN A FEW DEGREES ACROSS THE
DELMARVA. WE`VE ALSO ADJUSTED THE CLOUD COVER (LESS OF IT) DOWN
ACROSS THE AREA. THE EXPECTED HIGH LEVEL CLOUDS ARE STARTING TO
WORK THEIR WAY INTO THE REGION FROM THE SOUTHWEST.

WE`VE BEEN WATCHING THE STRATUS, SOUTH OF SUFFOLK COUNTY NY, SPIN
ALL AFTERNOON AND EVENING. BEFORE WE LOST DAYLIGHT, THE VISIBLE
SAT PIX SHOWED THIS FEATURE NICELY, EVEN DEPICTING A CENTER "EYE".
LOW RESOLUTION MODELS SHOW A WEAK TROF IN THIS AREA. HIGHER
RESOLUTION MODELS SHOW A WEAK LOW. RADAR IS ALSO PICKING UP THE
ROTATION.

THE FEATURE IS BRINGING A SOME PRECIPITATION TO LONG ISLAND AND
CONNECTICUT, AND WELL AS NORTHEAST NJ. THIS FEATURE IS MODELED TO
SLOWLY DRIFT SOUTHWEST TOWARD THE NJ COAST OVERNIGHT. THIS SHOULD
HELP TO PUSH THE LOWER STRATUS, WHICH MOVED NORTH TODAY, BACK
SOUTHWARD. IT SHOULD ALSO PUSH SOME FLURRIES OR SPRINKLES INTO OUR
NORTHEAST ZONES ADJACENT TO OKX. GRIDS HAVE BEEN UPDATED TO DEPICT
THIS.

PREVIOUS DISCUSSION...

THE CENTER OF A 1030 MB SURFACE HIGH OVER EASTERN CANADA WILL
CONTINUE TO RIDGE SOUTHWARD DOWN THE EASTERN SEABOARD THROUGH
TONIGHT. A MID- TO UPPER-LEVEL RIDGE AXIS WILL PROGRESS TOWARD THE
EAST COAST THIS EVENING.

SOME HI CLOUDS WILL SPILL INTO THE AREA OVERNIGHT AS THE RIDGE
SHIFTS DOWNSTREAM OF OUR AREA AND IS QUICKLY REPLACED BY A LEADING
SHORTWAVE TROUGH THAT IS EXPECTED TO MOVE IN FROM THE SOUTHWEST.

THE SOUTH TO NORTH LOW-LEVEL THERMAL GRADIENT ASSOCIATED WITH A WARM
FRONT IS FORECAST TO STRENGTHEN AS IT MOVES TOWARD SOUTHEAST VA LATE
TONIGHT. ISENTROPIC LIFT WILL DEVELOP ACROSS THE BOUNDARY AND EXPAND
NORTHWARD INTO THE DELMARVA BEFORE DAYBREAK. THE AIRMASS ON COLD
SIDE OF THIS BAROCLINIC ZONE WILL BE INITIALLY DRY SO EXPECT THE
THICKER LOW CLOUDS AND PRECIP TO REMAIN SOUTH OF DELAWARE AND THE
EASTERN SHORE OF MD TONIGHT.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
SOUTHERLY FLOW ALOFT AROUND THE BACKSIDE OF A WESTERN ATLANTIC RIDGE
AND AHEAD OF A TROUGH OVER THE NORTHERN PLAINS WILL BECOME
ESTABLISHED OVER THE EASTERN CONUS ON MONDAY. WAA DEVELOPS OVER THE
FORECAST AREA IN THIS PATTERN, ESPECIALLY IN THE LOW AND MID LEVELS.
AT THE SURFACE, HIGH PRESSURE IS FORECAST TO CONTINUE NOSING
SOUTHWARD DOWN THE EASTERN SIDE OF THE APPALACHIANS EVEN WITH THE
CENTER OF THE AFOREMENTIONED HIGH RETREATING TOWARD THE CANADIAN
MARITIMES. A CAD SETUP WILL KEEP THE COLDER AIR ANCHORED OVER OUR
REGION WITH A NORTHEASTERLY WIND NEAR THE SURFACE. THIS SHOULD
SUPPRESS THE ADVANCEMENT OF THE SURFACE WARM FRONT AS IT APPROACHES
FROM THE SOUTH ON MONDAY.

THE LATEST 12Z NAM CONTINUES TO BE QUICKER AND FARTHER NORTH WITH
THE DEVELOPMENT OF OVERRUNNING PRECIP COMPARED TO THE OTHER
OPERATIONAL MODELS. THE AIRMASS WILL BE VERY DRY INITIALLY, SO
PRECIP MAY NOT REACH THE GROUND AS QUICKLY AS THE NAM INDICATES.
HOWEVER, THERE APPEARS TO BE ENOUGH MOISTURE RETURN AND ISENTROPIC
LIFT FOR PRECIP TO EVENTUALLY OVERCOME THIS INITIAL DRY AIR,
ALLOWING THE PRECIP SHIELD TO EXPAND NORTHWARD THROUGH THE DAY.
CHANCE POPS FIRST ADVERTISED IN THE MORNING FOR THE DELMARVA, MIDDAY
FOR THE SOUTHERN PHILLY SUBURBS AND LATE AFTERNOON FOR THE I-80
CORRIDOR.

PTYPE WILL PREDOMINATELY BE RAIN ON MONDAY, BUT THERE COULD BE A
LIGHT WINTRY MIX (SNOW/SLEET) AWAY FROM THE COAST AT THE ONSET DUE
TO EVAPORATIONAL COOLING. THERE IS STILL NOT ENOUGH FORECAST
CERTAINTY TO PUBLISH A SNOWFALL MAP, BUT THE SETUP APPEARS LIMITED
FOR ANY ACCUMULATIONS EVEN IN THE HIGHER ELEVATIONS OF PA. WE
PREFERRED TO USE THE COOLER NAM/ECMWF FOR THERMAL PROFILES IN THIS
CAD SETUP TO DIAGNOSE POTENTIAL PTYPES AND FOR FORECASTING TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
UNSETTLED WEATHER WILL BE ACROSS THE REGION AT THE BEGINNING OF THE
LONG TERM. A H5 TROUGH WILL BE DEEPENING ACROSS THE MIDDLE PART OF
THE COUNTRY...AND ITS EFFECTS WILL BE FOR CLOUDS AND MOSTLY RAIN
BEGINNING MONDAY NIGHT AND PERSISTING INTO WEDNESDAY NIGHT AND
THURSDAY MORNING. THE FIRST BATCH OF RAIN WILL COME AS WEAK LOW
PRESSURE DEVELOPS ALONG THE CAROLINA COAST MONDAY AND MOVES
NORTHWARD ALONG THE NJ/DE COAST TUESDAY. WE HAVE CHC POPS N/W AND
LIKELY POPS S/E WITH THIS FEATURE. ON TUESDAY...THE HIGHER POPS MOVE
TO THE NORTHERN AREAS AS ONSHORE FLOW AND RESIDUAL MOISTURE FROM THE
LOW REMAIN ACROSS THE AREA.

THERE WILL NOT BE MUCH OF A BREAK IN THE WET PATTERN TUESDAY
NIGHT...ALTHOUGH SOME WEAK RIDGING WILL BE ACROSS THE AREA. ANOTHER
STRONGER LOW PRESSURE SYSTEM WILL BE DEVELOPING ACROSS THE SOUTHERN
STATES AND IT WILL MOVE NORTHWARD TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. THE LOW WILL TRACK TO THE WEST...RESULTING IN A SURGE OF
WARMER AIR ACROSS THE AREA. WE HAVE GONE ALONG WITH THE HIGH POPS
OFFERED BY WPC...WHICH ARE IN THE CATEGORICAL RANGE TUE NIGHT THRU
WED NIGHT.

A STRONG COLD FRONT WILL CROSS THE AREA OVERNIGHT WED NGT INTO THU.
IT APPEARS THAT MOST OF THE SHOWERS WILL BE DONE BY 12Z...BUT WE
HAVE LEFT IN A CHC FOR A FEW SHOWERS THU MORNING...IN CASE THE
SYSTEM SLOWS UP AT ALL. IT APPEARS THAT THE P-TYPE WILL STILL BE
RAIN...SINCE THE COLDER AIR WILL NOT ARRIVE FAST ENOUGH FOR A
CHANGEOVER.

THE REST OF THE EXTENDED PERIOD WILL FEATURE DRIER WEATHER AS A SFC
HIGH EXTENDS ACROSS THE AREA. THE H5 TROUGH WILL STILL BE TO THE
WEST...SO TEMPERATURES WILL REMAIN ABOVE NORMAL BOTH FRI AND SAT.
ANOTHER LOW AND DEVELOPING FRONT MAY BEGIN TO AFFECT THE AREA SAT
NIGHT INTO NEXT SUNDAY...LOW CHC POPS ARE IN THE GRIDS FOR THIS.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THE STRATUS THAT MOVED NORTH TODAY IS DRIFTIN BACK DOWN SOUTH
AGAIN. THE LOW CLOUDS ARE THROUGH TRENTON, HAVE JUST MOVED OVER
KPNE, AND IS HEADING TOWARD KPHL. WILL UPDATE THE TERMINALS TO REFLECT.

PREVIOUS DISCUSSION...

LEFTOVER OVC STRATOCU CONTINUES TO ERODE LATE THIS AFTN OVER MOST OF
THE TERMINALS. AT 20Z, TTN AND RDG LIE ON THE EDGE OF THESE CLOUDS,
WHICH ARE YIELDING MVFR CIGS BETWEEN 2500 AND 3000 FT. EXPECT THE
CLOUDS TO CLEAR OUT AT THESE TWO TERMINALS BY SUNSET AT THE LATEST.

VFR THIS EVE. VFR ANTICIPATED FOR MOST TERMINALS OVERNIGHT AND
MONDAY MORNING THOUGH THE 12Z NAM DEVELOPS STRATUS FROM PHL NORTH
AND EAST, RESULTING IN MVFR AND EVEN IFR CIGS BETWEEN BETWEEN
09-15Z. THIS MAY BE A BIT OVERDONE, BUT WILL STILL NEED TO MONITOR
THE POTENTIAL AS THE MARINE LAYER TRIES TO BECOME ESTABLISHED IN
CONCERT WITH A LIGHT NORTHEAST WIND IN THE BOUNDARY LAYER.
OTHERWISE, MID CLOUDS WILL QUICKLY OVERSPREAD THE AREA FROM
SOUTHWEST TO NORTHEAST IN THE MORNING. RAIN IS ALSO FORECAST TO
DEVELOP IN VICINITY OF ILG/MIV DURING THE MID TO LATE MORNING,
PHL/PNE/RDG DURING THE EARLY TO MID AFTERNOON AND ABE/TTN LATE IN
THE DAY.

OUTLOOK...

MON NIGHT THRU TUE...MOSTLY VFR. INCREASING CLOUDS LATE TUE NIGHT.
TUE NIGHT THRU THU MORNING...OCNL LOW CIGS/VSBYS IN RAIN AND FOG.
THU AFTERNOON THRU FRIDAY...MOSTLY VFR. GUSTY WEST/NORTHWEST WINDS.

&&

.MARINE...
LIGHT NORTHWEST WINDS 5-15 KT THIS AFTERNOON WILL BECOME NORTHERLY
TONIGHT AND NORTHEASTERLY ON MONDAY. SEAS GENERALLY 1-2 FT DURING
THIS TIME.

OUTLOOK...
MON NIGHT...SUB SCA CONDITIONS.
TUE/TUE NGT...SCA CONDITIONS ON THE OCEAN..SUB-SCA OVER DEL BAY.
WED THRU FRI...SCA CONDITIONS WITH LOW END GALE GUSTS WED NGT AND THU.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...O`HARA
NEAR TERM...KLEIN
SHORT TERM...KLEIN
LONG TERM...O`HARA
AVIATION...KLEIN/O`HARA
MARINE...KLEIN/O`HARA







000
FXUS61 KLWX 220231 AAA
AFDLWX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
931 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE COAST OVERNIGHT...AHEAD OF A WEAK
COASTAL LOW PRESSURE SYSTEM OVER THE SOUTHERN ATLANTIC. THE LOW
WILL TRACK UP THE MID-ATLANTIC COAST MONDAY INTO TUESDAY. A STRONG
COLD FRONT WILL APPROACH THE AREA WEDNESDAY BEFORE PASSING THROUGH
WEDNESDAY NIGHT. BREEZY CONDITIONS ON THURSDAY...THEN HIGH
PRESSURE WILL BUILD BACK INTO THE REGION TO CLOSE OUT THE WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
HIGH TEMPS ACROSS AREA WERE ON PAR W/ AVG VALUES FOR THIS...THE
WINTER SOLSTICE. HOWEVER...AFTER ONLY REACHING THE LOW-MID 40S
EARLIER THIS AFTN MOST AREAS ARE BACK BELOW FREEZING...WELL AHEAD
OF ANY INCOMING PRECIP. CLEAR SKIES AND CALM SFC WINDS EASILY
ALLOWING TEMPS TO DROP DOWN TOWARD CURRENT DEWPOINTS VALUES IN THE
LOWS 20S. SLOW AND STEADY DEVELOPMENT OF A COASTAL LOW PRES SYSTEM
OVER THE SRN ATLC STATES IS THE NEXT FEATURE TO MONITOR...AS DENSE
CLOUD COVER AND LIGHT/SCATTERED SHOWERS ARE EXPECTED TO MOVE UP
THE EASTERN SEABOARD OVERNIGHT.

MANY SMALLER-SCALE ELEMENTS ARE COMING TOGETHER OVER A MUCH LARGER
PICTURE AND WILL CONTINUE TO DO SO WELL INTO THE MIDDLE OF THE
CURRENT WEEK. NEARLY TWO-THIRDS OF THE CONUS WILL BE AFFECTED IN
SOME PART OF THESE ELEMENTS OR A LARGER COMBINATION OVER THE NEXT
FEW DAYS. THIS FIRST PIECE IS THE INITIAL GROUPING OF A SHORTWAVE
OVER THE SRN ATLC COAST AND A TROUGH STILL WELL BACK TO THE WEST.
THE TROUGH WILL FORCE THE ATLC MOISTURE UP THE COAST...THIS FIRST
BATCH AFFECTING OUR AREA MONDAY INTO EARLY TUE - W/ THE MORE
MOISTURE-LADEN SYSTEM MOVING THRU THE REGION ON THU.

SUCH A COMPLEX SYSTEM OF WAVES...TROUGHS...SYNOPTIC FEATURES
INTERACTING W/ EACH OTHER OVER A MULTI-DAY PERIOD CAN SHOW VERY
VARIED DEPICTIONS AMONGST THE GUIDANCE SUITE. HOWEVER...MOST
MEMBERS IN BOTH THE ENSEMBLE AND DETERMINISTIC FIELDS ARE IN
FAIRLY GOOD AGREEMENT EARLY ON W/ THE INCOMING PRECIP. THE NAM
STILL THE COLDER MODEL IN TERMS OF TEMPS/DEWPOINTS BUT IS NOW
COMING INTO BETTER AGREEMENT W/ GFS/EURO ON PRECIP TIMING.

THE I-95 CORRIDOR WHICH IS NORMALLY A DIVIDING LINE OF NEAR-
FREEZING TEMPS W/ INCOMING PRECIP IS NO DIFFERENT FOR THIS
INCOMING WAVE MON MORNING. HOWEVER...HI-RES AND NEAR TERM GUIDANCE
DOES NOT HAVE THE FIRST BATCHES OF LIGHT PRECIP ARRIVING UNTIL
POST-DAWN AND ACTUALLY MORE TOWARD MID-LATE MRNG...ESPECIALLY
FURTHER NORTH. TEMPS WILL STILL BE BORDERLINE FREEZING/SUB-
FREEZING ACROSS THE PIEDMONT/FOOTHILLS - WHERE THE FREEZING RAIN
ADZY IS IN EFFECT - BUT THE I-95 CORRIDOR MAY ONLY SEE A BRIEF
ONSET PERIOD OF A FZRA/SLEET MIX...THEN TEMPS WILL RISE EVEN A
COUPLE MORE DEGREES HEADING INTO THE LATE MRNG/EARLY AFTN.

THE SHEN VLY AND BLUE RIDGE WILL LIKELY BE ON THE WRN/NRN
PERIPHERY OF THE PRECIP BUT WILL BE MOST PRONE TO HOLDING ONTO THE
SUB-FREEZING CONDITIONS WELL INTO THE MRNG HRS AND EVEN THRU THE
AFTN POTENTIALLY. THE AMOUNTS AND POTENTIAL FOR PRECIP WILL BE THE
MAIN QUESTION BUT THERE IS GOOD CONFIDENCE THAT THESE AREAS WILL
HAVE TROUBLE SEEING TEMPS ABOVE FREEZING FOR VERY LONG TMRW.
LINGERING POCKETS OF DRIZZLE AND LIGHT/SCATTERED RAIN WILL BE THE
REASON FOR AN EXPANSION/EXTENSION OF THE ADZY FOR ALL/MOST OF THE
SHEN VLY/POTOMAC HIGHLANDS/BLUE RIDGE.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
LIGHT PRECIPITATION WILL CONTINUE MONDAY NIGHT INTO TUESDAY MORNING.
THE BIG QUESTION WILL BE HOW LONG THE CAD WEDGE WILL REMAIN IN
PLACE. THERE IS STILL POTENTIAL FOR TEMPERATURES TO REMAIN AT OR
BELOW FREEZING MAINLY WEST OF THE BLUE RIDGE LEAVING THE POTENTIAL
FOR LIGHT FREEZING RAIN TO CONTINUE. TO THE EAST OF THE BLUE RIDGE
AND ACROSS THE METRO AREAS...WARMER AIR WILL LIKELY WIN OUT KEEPING
PRECIPITATION IN THE FORM OF RAIN. A BRIEF RESPITE FROM THE
PRECIPITATION IS POSSIBLE TUESDAY AFTERNOON/EVENING BEFORE THE NEXT
ROUND OF RAINFALL MOVES IN FROM THE WEST LATER TUESDAY NIGHT.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
STRONG COLD FRONT CROSSING THE MID ATLANTIC REGION WEDNESDAY INTO
THURSDAY. LIQUID PRECIPITATION SHOULD ACCOMPANY THE FRONT EXCEPT
ALONG THE ALLEGHENY  FRONT WHERE ARRIVAL OF COLDER AIR WILL CAUSE THE
RAIN TO CHANGE OVER TO SNOW BEFORE PRECIPITATION ENDS THURSDAY.

PASSAGE OF SHORTWAVE WILL SUPPORT DEVELOPMENT OF A COASTAL LOW LATE
SATURDAY AND SUNDAY. PRECIPITATION MAY START AS A WINTRY MIX AT
HIGHER ELEVATIONS.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS INTO THE OVERNIGHT...W/ MID CLOUD DECKS INCREASING
TOWARD THE PREDAWN MON. PRECIPITATION WILL OVERSPREAD THE
TERMINALS MONDAY MORNING - MOST LIKELY POST-DAWN - FROM SOUTHWEST
TO NORTHEAST. FREEZING RAIN IS EXPECTED ACROSS KCHO AND POSSIBLY
KMRB AND KIAD FOR A RELATIVELY BRIEF PERIOD...W/ TEMPS HOVER NEAR
FREEZING DURING THE MID-MRNG HRS. FREEZING RAIN MAY MIX WITH
SLEET AND SNOW AT THE ONSET. RAIN IS EXPECTED ACROSS THE REST OF
THE TERMINALS. RAIN MAY MIX WITH SLEET AT THE ONSET. CIGS/VSBYS
WILL DETERIORATE TO MVFR LEVELS MONDAY WITH POSSIBLE IFR LEVELS.

SUB VFR CIGS AND VSBYS EXPECTED MONDAY NIGHT INTO TUESDAY. LIGHT
FREEZING RAIN WILL BE POSSIBLE WEST OF THE BLUE RIDGE WITH RAIN TO
THE EAST. A PRECIPITATION RESPITE MAY OCCUR TUESDAY AFTERNOON BEFORE
RAIN MOVES BACK IN LATER TUESDAY NIGHT. A STRONG COLD FRONT WILL
APPROACH THE TERMINALS WEDNESDAY BEFORE PASSING THROUGH
WEDNESDAY NIGHT. MORE RAIN AND SUBVFR CONDITIONS ARE EXPECTED.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS TONIGHT. LOW PRESSURE
WILL TRACK UP THE MID-ATLANTIC COAST MONDAY. A SMALL CRAFT
ADVISORY IS IN EFFECT FOR THE MIDDLE PORTIONS OF THE BAY AND LOWER
TIDAL POTOMAC RIVER.

WINDS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA MONDAY NIGHT THROUGH
TUESDAY NIGHT. A STRONG COLD FRONT WILL APPROACH THE WATERS
WEDNESDAY BEFORE PASSING THROUGH WEDNESDAY NIGHT. A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED FOR THE WATERS WEDNESDAY AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...FREEZING RAIN ADVISORY FROM 6 AM TO NOON EST MONDAY FOR VAZ025-
     026-029-036>040-050-051-501>504-507-508.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM TO 6 PM EST MONDAY FOR ANZ534-
     537-543.

&&

$$
UPDATE...GMS
PREV DISCUSSION...BJL/KRW/CEM







000
FXUS61 KLWX 220231 AAA
AFDLWX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
931 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF THE COAST OVERNIGHT...AHEAD OF A WEAK
COASTAL LOW PRESSURE SYSTEM OVER THE SOUTHERN ATLANTIC. THE LOW
WILL TRACK UP THE MID-ATLANTIC COAST MONDAY INTO TUESDAY. A STRONG
COLD FRONT WILL APPROACH THE AREA WEDNESDAY BEFORE PASSING THROUGH
WEDNESDAY NIGHT. BREEZY CONDITIONS ON THURSDAY...THEN HIGH
PRESSURE WILL BUILD BACK INTO THE REGION TO CLOSE OUT THE WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
HIGH TEMPS ACROSS AREA WERE ON PAR W/ AVG VALUES FOR THIS...THE
WINTER SOLSTICE. HOWEVER...AFTER ONLY REACHING THE LOW-MID 40S
EARLIER THIS AFTN MOST AREAS ARE BACK BELOW FREEZING...WELL AHEAD
OF ANY INCOMING PRECIP. CLEAR SKIES AND CALM SFC WINDS EASILY
ALLOWING TEMPS TO DROP DOWN TOWARD CURRENT DEWPOINTS VALUES IN THE
LOWS 20S. SLOW AND STEADY DEVELOPMENT OF A COASTAL LOW PRES SYSTEM
OVER THE SRN ATLC STATES IS THE NEXT FEATURE TO MONITOR...AS DENSE
CLOUD COVER AND LIGHT/SCATTERED SHOWERS ARE EXPECTED TO MOVE UP
THE EASTERN SEABOARD OVERNIGHT.

MANY SMALLER-SCALE ELEMENTS ARE COMING TOGETHER OVER A MUCH LARGER
PICTURE AND WILL CONTINUE TO DO SO WELL INTO THE MIDDLE OF THE
CURRENT WEEK. NEARLY TWO-THIRDS OF THE CONUS WILL BE AFFECTED IN
SOME PART OF THESE ELEMENTS OR A LARGER COMBINATION OVER THE NEXT
FEW DAYS. THIS FIRST PIECE IS THE INITIAL GROUPING OF A SHORTWAVE
OVER THE SRN ATLC COAST AND A TROUGH STILL WELL BACK TO THE WEST.
THE TROUGH WILL FORCE THE ATLC MOISTURE UP THE COAST...THIS FIRST
BATCH AFFECTING OUR AREA MONDAY INTO EARLY TUE - W/ THE MORE
MOISTURE-LADEN SYSTEM MOVING THRU THE REGION ON THU.

SUCH A COMPLEX SYSTEM OF WAVES...TROUGHS...SYNOPTIC FEATURES
INTERACTING W/ EACH OTHER OVER A MULTI-DAY PERIOD CAN SHOW VERY
VARIED DEPICTIONS AMONGST THE GUIDANCE SUITE. HOWEVER...MOST
MEMBERS IN BOTH THE ENSEMBLE AND DETERMINISTIC FIELDS ARE IN
FAIRLY GOOD AGREEMENT EARLY ON W/ THE INCOMING PRECIP. THE NAM
STILL THE COLDER MODEL IN TERMS OF TEMPS/DEWPOINTS BUT IS NOW
COMING INTO BETTER AGREEMENT W/ GFS/EURO ON PRECIP TIMING.

THE I-95 CORRIDOR WHICH IS NORMALLY A DIVIDING LINE OF NEAR-
FREEZING TEMPS W/ INCOMING PRECIP IS NO DIFFERENT FOR THIS
INCOMING WAVE MON MORNING. HOWEVER...HI-RES AND NEAR TERM GUIDANCE
DOES NOT HAVE THE FIRST BATCHES OF LIGHT PRECIP ARRIVING UNTIL
POST-DAWN AND ACTUALLY MORE TOWARD MID-LATE MRNG...ESPECIALLY
FURTHER NORTH. TEMPS WILL STILL BE BORDERLINE FREEZING/SUB-
FREEZING ACROSS THE PIEDMONT/FOOTHILLS - WHERE THE FREEZING RAIN
ADZY IS IN EFFECT - BUT THE I-95 CORRIDOR MAY ONLY SEE A BRIEF
ONSET PERIOD OF A FZRA/SLEET MIX...THEN TEMPS WILL RISE EVEN A
COUPLE MORE DEGREES HEADING INTO THE LATE MRNG/EARLY AFTN.

THE SHEN VLY AND BLUE RIDGE WILL LIKELY BE ON THE WRN/NRN
PERIPHERY OF THE PRECIP BUT WILL BE MOST PRONE TO HOLDING ONTO THE
SUB-FREEZING CONDITIONS WELL INTO THE MRNG HRS AND EVEN THRU THE
AFTN POTENTIALLY. THE AMOUNTS AND POTENTIAL FOR PRECIP WILL BE THE
MAIN QUESTION BUT THERE IS GOOD CONFIDENCE THAT THESE AREAS WILL
HAVE TROUBLE SEEING TEMPS ABOVE FREEZING FOR VERY LONG TMRW.
LINGERING POCKETS OF DRIZZLE AND LIGHT/SCATTERED RAIN WILL BE THE
REASON FOR AN EXPANSION/EXTENSION OF THE ADZY FOR ALL/MOST OF THE
SHEN VLY/POTOMAC HIGHLANDS/BLUE RIDGE.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
LIGHT PRECIPITATION WILL CONTINUE MONDAY NIGHT INTO TUESDAY MORNING.
THE BIG QUESTION WILL BE HOW LONG THE CAD WEDGE WILL REMAIN IN
PLACE. THERE IS STILL POTENTIAL FOR TEMPERATURES TO REMAIN AT OR
BELOW FREEZING MAINLY WEST OF THE BLUE RIDGE LEAVING THE POTENTIAL
FOR LIGHT FREEZING RAIN TO CONTINUE. TO THE EAST OF THE BLUE RIDGE
AND ACROSS THE METRO AREAS...WARMER AIR WILL LIKELY WIN OUT KEEPING
PRECIPITATION IN THE FORM OF RAIN. A BRIEF RESPITE FROM THE
PRECIPITATION IS POSSIBLE TUESDAY AFTERNOON/EVENING BEFORE THE NEXT
ROUND OF RAINFALL MOVES IN FROM THE WEST LATER TUESDAY NIGHT.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
STRONG COLD FRONT CROSSING THE MID ATLANTIC REGION WEDNESDAY INTO
THURSDAY. LIQUID PRECIPITATION SHOULD ACCOMPANY THE FRONT EXCEPT
ALONG THE ALLEGHENY  FRONT WHERE ARRIVAL OF COLDER AIR WILL CAUSE THE
RAIN TO CHANGE OVER TO SNOW BEFORE PRECIPITATION ENDS THURSDAY.

PASSAGE OF SHORTWAVE WILL SUPPORT DEVELOPMENT OF A COASTAL LOW LATE
SATURDAY AND SUNDAY. PRECIPITATION MAY START AS A WINTRY MIX AT
HIGHER ELEVATIONS.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS INTO THE OVERNIGHT...W/ MID CLOUD DECKS INCREASING
TOWARD THE PREDAWN MON. PRECIPITATION WILL OVERSPREAD THE
TERMINALS MONDAY MORNING - MOST LIKELY POST-DAWN - FROM SOUTHWEST
TO NORTHEAST. FREEZING RAIN IS EXPECTED ACROSS KCHO AND POSSIBLY
KMRB AND KIAD FOR A RELATIVELY BRIEF PERIOD...W/ TEMPS HOVER NEAR
FREEZING DURING THE MID-MRNG HRS. FREEZING RAIN MAY MIX WITH
SLEET AND SNOW AT THE ONSET. RAIN IS EXPECTED ACROSS THE REST OF
THE TERMINALS. RAIN MAY MIX WITH SLEET AT THE ONSET. CIGS/VSBYS
WILL DETERIORATE TO MVFR LEVELS MONDAY WITH POSSIBLE IFR LEVELS.

SUB VFR CIGS AND VSBYS EXPECTED MONDAY NIGHT INTO TUESDAY. LIGHT
FREEZING RAIN WILL BE POSSIBLE WEST OF THE BLUE RIDGE WITH RAIN TO
THE EAST. A PRECIPITATION RESPITE MAY OCCUR TUESDAY AFTERNOON BEFORE
RAIN MOVES BACK IN LATER TUESDAY NIGHT. A STRONG COLD FRONT WILL
APPROACH THE TERMINALS WEDNESDAY BEFORE PASSING THROUGH
WEDNESDAY NIGHT. MORE RAIN AND SUBVFR CONDITIONS ARE EXPECTED.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS TONIGHT. LOW PRESSURE
WILL TRACK UP THE MID-ATLANTIC COAST MONDAY. A SMALL CRAFT
ADVISORY IS IN EFFECT FOR THE MIDDLE PORTIONS OF THE BAY AND LOWER
TIDAL POTOMAC RIVER.

WINDS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA MONDAY NIGHT THROUGH
TUESDAY NIGHT. A STRONG COLD FRONT WILL APPROACH THE WATERS
WEDNESDAY BEFORE PASSING THROUGH WEDNESDAY NIGHT. A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED FOR THE WATERS WEDNESDAY AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...FREEZING RAIN ADVISORY FROM 6 AM TO NOON EST MONDAY FOR VAZ025-
     026-029-036>040-050-051-501>504-507-508.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM TO 6 PM EST MONDAY FOR ANZ534-
     537-543.

&&

$$
UPDATE...GMS
PREV DISCUSSION...BJL/KRW/CEM








000
FXUS61 KPBZ 220216
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
916 PM EST SUN DEC 21 2014

.SYNOPSIS...
MIDWESTERN LOW PRESSURE WILL BRING WARMER TEMPERATURES AND RAIN TO
THE UPPER OHIO VALLEY REGION FOR THE FIRST HALF OF THE WEEK. SNOW
SHOWER CHANCES WILL COME WITH PASSAGE OF THAT SYSTEMS COLD FRONT
ON CHRISTMAS.

&&

.NEAR TERM /THROUGH MONDAY/...
WITH 915PM UPDATE...CONTINUED TO MAKE SKY COVER ADJUSTMENTS FOR
LOW CLOUDS MOVING TO THE NORTH. AT THIS POINT APPEARS THAT LOW
CLOUDS ARE CONTAINED TO MERCER/VENANGO COUNTIES...WITH SCATTERED
HIGH CLOUDS ELSEWHERE. ALSO UPDATED HOURLY TEMPERATURE TRENDS
AGAIN...AS TEMPERATURES HAVE DROPPED SLIGHTLY BELOW PREVIOUS
FORECAST. A QUICK LOOK AT THE 00Z NAM/HRRR SHOW PRECIPITATION
REMAINING SOUTH OF THE FORECAST AREA AS OF 15Z...DIMINISHING THE
CHANCES THAT PRECIPITATION WOULD REACH GARRETT/TUCKER COUNTIES
BEFORE SURFACE TEMPERATURES HAVE A CHANCE TO RISE ABOVE FREEZING.
PREVIOUS DISCUSSION FOLLOWS.

WARM ADVECTION BEGINS IN EARNEST OVERNIGHT...BRINGING H850 TEMPS
ABOVE ZERO FOR THE SOUTHERN CWA BY 12Z MONDAY. SOME LOWER CLOUDS
COULD BE REALIZED PRIOR TO 12Z ALONG EAST-FACING SLOPES IN
GARRETT/TUCKER COUNTIES. GENERALLY LEANED TOWARDS THE WARMER
TEMPERATURE GUIDANCE FOR LOWS.

ON MONDAY...INVERTED TROUGH SETS UP ALONG THE CAROLINA COAST.  WITH
DEPARTING HIGH ACROSS NEW ENGLAND...A COLD AIR DAMMING SCENARIO
LOOKS TO BE SETTING UP FOR THE EAST-FACING RIDGES. FOR MOST
AREAS...IT WILL SIMPLY BE A MOSTLY CLOUDY DAY.  BETTER
MOISTURE SPINS AROUND THE INVERTED TROUGH TOWARDS THE SOUTHEAST
CORNER OF THE CWA BEGINNING LATER MONDAY MORNING. WITH THE
OVERNIGHT WARM ADVECTION ALOFT AND COLD AIR EXPECTED TO BE TRAPPED
IN THE VALLEYS...A TEMPERATURE STRUCTURE IDEAL FOR FREEZING RAIN
WILL BE PRESENT ACROSS GARRETT/PRESTON/TUCKER COUNTIES.
HOWEVER...QPF WILL BE THE LIMITING FACTOR AS MOISTURE AND LIFT ARE
TOO SHALLOW TO SUPPORT PRECIPITATION OF ANY SIGNIFICANCE. CANNOT
JUSTIFY ANYTHING HIGHER THAN CHANCE POPS AT PRESENT. ONLY A COUPLE
HUNDREDTHS OF AN INCH OF LIQUID ARE EXPECTED AT MOST. WILL NOT BE
ISSUING ANY HEADLINES AT THE PRESENT TIME. SPS CAN BE USED IN THE
MORNING IF THE THREAT INCREASES. CONTINUED WARM ADVECTION WEST OF
THE RIDGES WILL PUSH MONDAY HIGH TEMPS AT LEAST SEVERAL DEGREES
ABOVE NORMAL...WHILE TEMPS REMAIN IN THE 30S ALONG THE EASTERN CWA
BORDER.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
UPPER TROUGH WILL AMPLIFY AND SLOWLY PIVOT EASTWARD DURING THIS TIME
FRAME...BECOMING MORE NEGATIVELY TILTED WITH THE HELP OF A
STRENGTHENING UPPER LEVEL JET BY LATE WEDNESDAY. EARLY ON...THERE
STILL REMAINS SOME UNCERTAINTY IN REGARD TO THE AMOUNT OF PRECIP
THAT WE WILL SEE ON TUESDAY...AS WE WILL BE PARKED IN BETWEEN THE
BETTER MOISTURE FROM THE WEAK COASTAL SYSTEM...AND THE DEEPENING
MOISTURE ASSOCIATED WITH THE COLD FRONT TO OUR WEST. IN
ADDITION...S-SE WIND SHOULD HELP PROVIDE SOME DOWNSLOPING AND DRYING
JUST EAST OF THE RIDGES IN PA/WV. WITH THIS IN MIND...OPTED TO STAY
WITH THE CHANCE POPS FOR THE DAY TUESDAY. WILL INCREASE POPS
OVERNIGHT AS THE LOW LEVEL JET STRENGTHS AND HELPS TO PULL MOISTURE
FROM THE GULF NORTHWARD. WITH THE NEARLY NORTHWARD PROGRESSION OF
THE DEVELOPING SURFACE LOW...BOTH THE ECMWF AND GFS SUGGEST THE BULK
OF THE HEAVIEST RAIN WILL STAY JUST WEST OF THE FORECAST AREA...WITH
THE BEST CHANCE FOR MODERATE RAIN TO BE AS THE COLD FRONT CROSSES
WEDNESDAY NIGHT. THIS SHOULD LIMIT ANY FLOOD THREAT FOR THE PERIOD.

STRONG WARM ADVECTION WILL BE ONGOING THROUGH THE ENTIRE TIME
PERIOD. EVEN WITH CLOUD COVER...HIGH TEMPERATURES ON BOTH TUESDAY
AND WEDNESDAY SHOULD BE WELL ABOVE SEASONAL VALUES WITH HIGHS
LIKELY TO REACH THE MID 50`S.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
CDFNT PASSAGE WILL INITIATE SNOW SHOWER CHANCES ON CHRISTMAS...BUT
LACK OF DEPTH TO THE COLD LYR...DRY ADVCTN IN THE MID LVLS ON THE
SRN PERIMETER OF NWD DIGGING UPR LOW...AND RAPIDLY ENSUING WARM
ADVCTN WL ENSURE A LACK OF SNOW COVER FOR CHRISTMAS.

THE RMNDR OF THE LONG TERM PD IS PROGGED TO FEATURE SEASONAL TEMPS
WITH A LATE WEEK COOLING TREND AS MDLS PROG A REAMPLIFYING FLOW
PTN WITH ERN CONUS TROFFG.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
GENL IMPROVEMENT TO VFR FOR ALL TAF SITES CAN BE EXPECTED FOR THE
TAF PD AS SLY FLOW ALOFT INTENSIFIES OVR LINGER SFC HIGH PRES.

OUTLOOK.../MONDAY THROUGH FRIDAY/...
MIDWRN LOW PRES WL SPREAD RAIN AND RESTRICTIONS OVR AREA PORTS ON
TUESDAY AND WEDNESDAY. IMPROVEMENTS ARE EXPECTED TO BE INITIATED
LTR ON THURSDAY WITH DRY SHRTWV RIDGING.

&&

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

&&

$$







000
FXUS61 KPBZ 220216
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
916 PM EST SUN DEC 21 2014

.SYNOPSIS...
MIDWESTERN LOW PRESSURE WILL BRING WARMER TEMPERATURES AND RAIN TO
THE UPPER OHIO VALLEY REGION FOR THE FIRST HALF OF THE WEEK. SNOW
SHOWER CHANCES WILL COME WITH PASSAGE OF THAT SYSTEMS COLD FRONT
ON CHRISTMAS.

&&

.NEAR TERM /THROUGH MONDAY/...
WITH 915PM UPDATE...CONTINUED TO MAKE SKY COVER ADJUSTMENTS FOR
LOW CLOUDS MOVING TO THE NORTH. AT THIS POINT APPEARS THAT LOW
CLOUDS ARE CONTAINED TO MERCER/VENANGO COUNTIES...WITH SCATTERED
HIGH CLOUDS ELSEWHERE. ALSO UPDATED HOURLY TEMPERATURE TRENDS
AGAIN...AS TEMPERATURES HAVE DROPPED SLIGHTLY BELOW PREVIOUS
FORECAST. A QUICK LOOK AT THE 00Z NAM/HRRR SHOW PRECIPITATION
REMAINING SOUTH OF THE FORECAST AREA AS OF 15Z...DIMINISHING THE
CHANCES THAT PRECIPITATION WOULD REACH GARRETT/TUCKER COUNTIES
BEFORE SURFACE TEMPERATURES HAVE A CHANCE TO RISE ABOVE FREEZING.
PREVIOUS DISCUSSION FOLLOWS.

WARM ADVECTION BEGINS IN EARNEST OVERNIGHT...BRINGING H850 TEMPS
ABOVE ZERO FOR THE SOUTHERN CWA BY 12Z MONDAY. SOME LOWER CLOUDS
COULD BE REALIZED PRIOR TO 12Z ALONG EAST-FACING SLOPES IN
GARRETT/TUCKER COUNTIES. GENERALLY LEANED TOWARDS THE WARMER
TEMPERATURE GUIDANCE FOR LOWS.

ON MONDAY...INVERTED TROUGH SETS UP ALONG THE CAROLINA COAST.  WITH
DEPARTING HIGH ACROSS NEW ENGLAND...A COLD AIR DAMMING SCENARIO
LOOKS TO BE SETTING UP FOR THE EAST-FACING RIDGES. FOR MOST
AREAS...IT WILL SIMPLY BE A MOSTLY CLOUDY DAY.  BETTER
MOISTURE SPINS AROUND THE INVERTED TROUGH TOWARDS THE SOUTHEAST
CORNER OF THE CWA BEGINNING LATER MONDAY MORNING. WITH THE
OVERNIGHT WARM ADVECTION ALOFT AND COLD AIR EXPECTED TO BE TRAPPED
IN THE VALLEYS...A TEMPERATURE STRUCTURE IDEAL FOR FREEZING RAIN
WILL BE PRESENT ACROSS GARRETT/PRESTON/TUCKER COUNTIES.
HOWEVER...QPF WILL BE THE LIMITING FACTOR AS MOISTURE AND LIFT ARE
TOO SHALLOW TO SUPPORT PRECIPITATION OF ANY SIGNIFICANCE. CANNOT
JUSTIFY ANYTHING HIGHER THAN CHANCE POPS AT PRESENT. ONLY A COUPLE
HUNDREDTHS OF AN INCH OF LIQUID ARE EXPECTED AT MOST. WILL NOT BE
ISSUING ANY HEADLINES AT THE PRESENT TIME. SPS CAN BE USED IN THE
MORNING IF THE THREAT INCREASES. CONTINUED WARM ADVECTION WEST OF
THE RIDGES WILL PUSH MONDAY HIGH TEMPS AT LEAST SEVERAL DEGREES
ABOVE NORMAL...WHILE TEMPS REMAIN IN THE 30S ALONG THE EASTERN CWA
BORDER.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
UPPER TROUGH WILL AMPLIFY AND SLOWLY PIVOT EASTWARD DURING THIS TIME
FRAME...BECOMING MORE NEGATIVELY TILTED WITH THE HELP OF A
STRENGTHENING UPPER LEVEL JET BY LATE WEDNESDAY. EARLY ON...THERE
STILL REMAINS SOME UNCERTAINTY IN REGARD TO THE AMOUNT OF PRECIP
THAT WE WILL SEE ON TUESDAY...AS WE WILL BE PARKED IN BETWEEN THE
BETTER MOISTURE FROM THE WEAK COASTAL SYSTEM...AND THE DEEPENING
MOISTURE ASSOCIATED WITH THE COLD FRONT TO OUR WEST. IN
ADDITION...S-SE WIND SHOULD HELP PROVIDE SOME DOWNSLOPING AND DRYING
JUST EAST OF THE RIDGES IN PA/WV. WITH THIS IN MIND...OPTED TO STAY
WITH THE CHANCE POPS FOR THE DAY TUESDAY. WILL INCREASE POPS
OVERNIGHT AS THE LOW LEVEL JET STRENGTHS AND HELPS TO PULL MOISTURE
FROM THE GULF NORTHWARD. WITH THE NEARLY NORTHWARD PROGRESSION OF
THE DEVELOPING SURFACE LOW...BOTH THE ECMWF AND GFS SUGGEST THE BULK
OF THE HEAVIEST RAIN WILL STAY JUST WEST OF THE FORECAST AREA...WITH
THE BEST CHANCE FOR MODERATE RAIN TO BE AS THE COLD FRONT CROSSES
WEDNESDAY NIGHT. THIS SHOULD LIMIT ANY FLOOD THREAT FOR THE PERIOD.

STRONG WARM ADVECTION WILL BE ONGOING THROUGH THE ENTIRE TIME
PERIOD. EVEN WITH CLOUD COVER...HIGH TEMPERATURES ON BOTH TUESDAY
AND WEDNESDAY SHOULD BE WELL ABOVE SEASONAL VALUES WITH HIGHS
LIKELY TO REACH THE MID 50`S.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
CDFNT PASSAGE WILL INITIATE SNOW SHOWER CHANCES ON CHRISTMAS...BUT
LACK OF DEPTH TO THE COLD LYR...DRY ADVCTN IN THE MID LVLS ON THE
SRN PERIMETER OF NWD DIGGING UPR LOW...AND RAPIDLY ENSUING WARM
ADVCTN WL ENSURE A LACK OF SNOW COVER FOR CHRISTMAS.

THE RMNDR OF THE LONG TERM PD IS PROGGED TO FEATURE SEASONAL TEMPS
WITH A LATE WEEK COOLING TREND AS MDLS PROG A REAMPLIFYING FLOW
PTN WITH ERN CONUS TROFFG.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
GENL IMPROVEMENT TO VFR FOR ALL TAF SITES CAN BE EXPECTED FOR THE
TAF PD AS SLY FLOW ALOFT INTENSIFIES OVR LINGER SFC HIGH PRES.

OUTLOOK.../MONDAY THROUGH FRIDAY/...
MIDWRN LOW PRES WL SPREAD RAIN AND RESTRICTIONS OVR AREA PORTS ON
TUESDAY AND WEDNESDAY. IMPROVEMENTS ARE EXPECTED TO BE INITIATED
LTR ON THURSDAY WITH DRY SHRTWV RIDGING.

&&

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

&&

$$







000
FXUS61 KPBZ 220216
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
916 PM EST SUN DEC 21 2014

.SYNOPSIS...
MIDWESTERN LOW PRESSURE WILL BRING WARMER TEMPERATURES AND RAIN TO
THE UPPER OHIO VALLEY REGION FOR THE FIRST HALF OF THE WEEK. SNOW
SHOWER CHANCES WILL COME WITH PASSAGE OF THAT SYSTEMS COLD FRONT
ON CHRISTMAS.

&&

.NEAR TERM /THROUGH MONDAY/...
WITH 915PM UPDATE...CONTINUED TO MAKE SKY COVER ADJUSTMENTS FOR
LOW CLOUDS MOVING TO THE NORTH. AT THIS POINT APPEARS THAT LOW
CLOUDS ARE CONTAINED TO MERCER/VENANGO COUNTIES...WITH SCATTERED
HIGH CLOUDS ELSEWHERE. ALSO UPDATED HOURLY TEMPERATURE TRENDS
AGAIN...AS TEMPERATURES HAVE DROPPED SLIGHTLY BELOW PREVIOUS
FORECAST. A QUICK LOOK AT THE 00Z NAM/HRRR SHOW PRECIPITATION
REMAINING SOUTH OF THE FORECAST AREA AS OF 15Z...DIMINISHING THE
CHANCES THAT PRECIPITATION WOULD REACH GARRETT/TUCKER COUNTIES
BEFORE SURFACE TEMPERATURES HAVE A CHANCE TO RISE ABOVE FREEZING.
PREVIOUS DISCUSSION FOLLOWS.

WARM ADVECTION BEGINS IN EARNEST OVERNIGHT...BRINGING H850 TEMPS
ABOVE ZERO FOR THE SOUTHERN CWA BY 12Z MONDAY. SOME LOWER CLOUDS
COULD BE REALIZED PRIOR TO 12Z ALONG EAST-FACING SLOPES IN
GARRETT/TUCKER COUNTIES. GENERALLY LEANED TOWARDS THE WARMER
TEMPERATURE GUIDANCE FOR LOWS.

ON MONDAY...INVERTED TROUGH SETS UP ALONG THE CAROLINA COAST.  WITH
DEPARTING HIGH ACROSS NEW ENGLAND...A COLD AIR DAMMING SCENARIO
LOOKS TO BE SETTING UP FOR THE EAST-FACING RIDGES. FOR MOST
AREAS...IT WILL SIMPLY BE A MOSTLY CLOUDY DAY.  BETTER
MOISTURE SPINS AROUND THE INVERTED TROUGH TOWARDS THE SOUTHEAST
CORNER OF THE CWA BEGINNING LATER MONDAY MORNING. WITH THE
OVERNIGHT WARM ADVECTION ALOFT AND COLD AIR EXPECTED TO BE TRAPPED
IN THE VALLEYS...A TEMPERATURE STRUCTURE IDEAL FOR FREEZING RAIN
WILL BE PRESENT ACROSS GARRETT/PRESTON/TUCKER COUNTIES.
HOWEVER...QPF WILL BE THE LIMITING FACTOR AS MOISTURE AND LIFT ARE
TOO SHALLOW TO SUPPORT PRECIPITATION OF ANY SIGNIFICANCE. CANNOT
JUSTIFY ANYTHING HIGHER THAN CHANCE POPS AT PRESENT. ONLY A COUPLE
HUNDREDTHS OF AN INCH OF LIQUID ARE EXPECTED AT MOST. WILL NOT BE
ISSUING ANY HEADLINES AT THE PRESENT TIME. SPS CAN BE USED IN THE
MORNING IF THE THREAT INCREASES. CONTINUED WARM ADVECTION WEST OF
THE RIDGES WILL PUSH MONDAY HIGH TEMPS AT LEAST SEVERAL DEGREES
ABOVE NORMAL...WHILE TEMPS REMAIN IN THE 30S ALONG THE EASTERN CWA
BORDER.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
UPPER TROUGH WILL AMPLIFY AND SLOWLY PIVOT EASTWARD DURING THIS TIME
FRAME...BECOMING MORE NEGATIVELY TILTED WITH THE HELP OF A
STRENGTHENING UPPER LEVEL JET BY LATE WEDNESDAY. EARLY ON...THERE
STILL REMAINS SOME UNCERTAINTY IN REGARD TO THE AMOUNT OF PRECIP
THAT WE WILL SEE ON TUESDAY...AS WE WILL BE PARKED IN BETWEEN THE
BETTER MOISTURE FROM THE WEAK COASTAL SYSTEM...AND THE DEEPENING
MOISTURE ASSOCIATED WITH THE COLD FRONT TO OUR WEST. IN
ADDITION...S-SE WIND SHOULD HELP PROVIDE SOME DOWNSLOPING AND DRYING
JUST EAST OF THE RIDGES IN PA/WV. WITH THIS IN MIND...OPTED TO STAY
WITH THE CHANCE POPS FOR THE DAY TUESDAY. WILL INCREASE POPS
OVERNIGHT AS THE LOW LEVEL JET STRENGTHS AND HELPS TO PULL MOISTURE
FROM THE GULF NORTHWARD. WITH THE NEARLY NORTHWARD PROGRESSION OF
THE DEVELOPING SURFACE LOW...BOTH THE ECMWF AND GFS SUGGEST THE BULK
OF THE HEAVIEST RAIN WILL STAY JUST WEST OF THE FORECAST AREA...WITH
THE BEST CHANCE FOR MODERATE RAIN TO BE AS THE COLD FRONT CROSSES
WEDNESDAY NIGHT. THIS SHOULD LIMIT ANY FLOOD THREAT FOR THE PERIOD.

STRONG WARM ADVECTION WILL BE ONGOING THROUGH THE ENTIRE TIME
PERIOD. EVEN WITH CLOUD COVER...HIGH TEMPERATURES ON BOTH TUESDAY
AND WEDNESDAY SHOULD BE WELL ABOVE SEASONAL VALUES WITH HIGHS
LIKELY TO REACH THE MID 50`S.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
CDFNT PASSAGE WILL INITIATE SNOW SHOWER CHANCES ON CHRISTMAS...BUT
LACK OF DEPTH TO THE COLD LYR...DRY ADVCTN IN THE MID LVLS ON THE
SRN PERIMETER OF NWD DIGGING UPR LOW...AND RAPIDLY ENSUING WARM
ADVCTN WL ENSURE A LACK OF SNOW COVER FOR CHRISTMAS.

THE RMNDR OF THE LONG TERM PD IS PROGGED TO FEATURE SEASONAL TEMPS
WITH A LATE WEEK COOLING TREND AS MDLS PROG A REAMPLIFYING FLOW
PTN WITH ERN CONUS TROFFG.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
GENL IMPROVEMENT TO VFR FOR ALL TAF SITES CAN BE EXPECTED FOR THE
TAF PD AS SLY FLOW ALOFT INTENSIFIES OVR LINGER SFC HIGH PRES.

OUTLOOK.../MONDAY THROUGH FRIDAY/...
MIDWRN LOW PRES WL SPREAD RAIN AND RESTRICTIONS OVR AREA PORTS ON
TUESDAY AND WEDNESDAY. IMPROVEMENTS ARE EXPECTED TO BE INITIATED
LTR ON THURSDAY WITH DRY SHRTWV RIDGING.

&&

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

&&

$$








000
FXUS61 KPBZ 220216
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
916 PM EST SUN DEC 21 2014

.SYNOPSIS...
MIDWESTERN LOW PRESSURE WILL BRING WARMER TEMPERATURES AND RAIN TO
THE UPPER OHIO VALLEY REGION FOR THE FIRST HALF OF THE WEEK. SNOW
SHOWER CHANCES WILL COME WITH PASSAGE OF THAT SYSTEMS COLD FRONT
ON CHRISTMAS.

&&

.NEAR TERM /THROUGH MONDAY/...
WITH 915PM UPDATE...CONTINUED TO MAKE SKY COVER ADJUSTMENTS FOR
LOW CLOUDS MOVING TO THE NORTH. AT THIS POINT APPEARS THAT LOW
CLOUDS ARE CONTAINED TO MERCER/VENANGO COUNTIES...WITH SCATTERED
HIGH CLOUDS ELSEWHERE. ALSO UPDATED HOURLY TEMPERATURE TRENDS
AGAIN...AS TEMPERATURES HAVE DROPPED SLIGHTLY BELOW PREVIOUS
FORECAST. A QUICK LOOK AT THE 00Z NAM/HRRR SHOW PRECIPITATION
REMAINING SOUTH OF THE FORECAST AREA AS OF 15Z...DIMINISHING THE
CHANCES THAT PRECIPITATION WOULD REACH GARRETT/TUCKER COUNTIES
BEFORE SURFACE TEMPERATURES HAVE A CHANCE TO RISE ABOVE FREEZING.
PREVIOUS DISCUSSION FOLLOWS.

WARM ADVECTION BEGINS IN EARNEST OVERNIGHT...BRINGING H850 TEMPS
ABOVE ZERO FOR THE SOUTHERN CWA BY 12Z MONDAY. SOME LOWER CLOUDS
COULD BE REALIZED PRIOR TO 12Z ALONG EAST-FACING SLOPES IN
GARRETT/TUCKER COUNTIES. GENERALLY LEANED TOWARDS THE WARMER
TEMPERATURE GUIDANCE FOR LOWS.

ON MONDAY...INVERTED TROUGH SETS UP ALONG THE CAROLINA COAST.  WITH
DEPARTING HIGH ACROSS NEW ENGLAND...A COLD AIR DAMMING SCENARIO
LOOKS TO BE SETTING UP FOR THE EAST-FACING RIDGES. FOR MOST
AREAS...IT WILL SIMPLY BE A MOSTLY CLOUDY DAY.  BETTER
MOISTURE SPINS AROUND THE INVERTED TROUGH TOWARDS THE SOUTHEAST
CORNER OF THE CWA BEGINNING LATER MONDAY MORNING. WITH THE
OVERNIGHT WARM ADVECTION ALOFT AND COLD AIR EXPECTED TO BE TRAPPED
IN THE VALLEYS...A TEMPERATURE STRUCTURE IDEAL FOR FREEZING RAIN
WILL BE PRESENT ACROSS GARRETT/PRESTON/TUCKER COUNTIES.
HOWEVER...QPF WILL BE THE LIMITING FACTOR AS MOISTURE AND LIFT ARE
TOO SHALLOW TO SUPPORT PRECIPITATION OF ANY SIGNIFICANCE. CANNOT
JUSTIFY ANYTHING HIGHER THAN CHANCE POPS AT PRESENT. ONLY A COUPLE
HUNDREDTHS OF AN INCH OF LIQUID ARE EXPECTED AT MOST. WILL NOT BE
ISSUING ANY HEADLINES AT THE PRESENT TIME. SPS CAN BE USED IN THE
MORNING IF THE THREAT INCREASES. CONTINUED WARM ADVECTION WEST OF
THE RIDGES WILL PUSH MONDAY HIGH TEMPS AT LEAST SEVERAL DEGREES
ABOVE NORMAL...WHILE TEMPS REMAIN IN THE 30S ALONG THE EASTERN CWA
BORDER.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
UPPER TROUGH WILL AMPLIFY AND SLOWLY PIVOT EASTWARD DURING THIS TIME
FRAME...BECOMING MORE NEGATIVELY TILTED WITH THE HELP OF A
STRENGTHENING UPPER LEVEL JET BY LATE WEDNESDAY. EARLY ON...THERE
STILL REMAINS SOME UNCERTAINTY IN REGARD TO THE AMOUNT OF PRECIP
THAT WE WILL SEE ON TUESDAY...AS WE WILL BE PARKED IN BETWEEN THE
BETTER MOISTURE FROM THE WEAK COASTAL SYSTEM...AND THE DEEPENING
MOISTURE ASSOCIATED WITH THE COLD FRONT TO OUR WEST. IN
ADDITION...S-SE WIND SHOULD HELP PROVIDE SOME DOWNSLOPING AND DRYING
JUST EAST OF THE RIDGES IN PA/WV. WITH THIS IN MIND...OPTED TO STAY
WITH THE CHANCE POPS FOR THE DAY TUESDAY. WILL INCREASE POPS
OVERNIGHT AS THE LOW LEVEL JET STRENGTHS AND HELPS TO PULL MOISTURE
FROM THE GULF NORTHWARD. WITH THE NEARLY NORTHWARD PROGRESSION OF
THE DEVELOPING SURFACE LOW...BOTH THE ECMWF AND GFS SUGGEST THE BULK
OF THE HEAVIEST RAIN WILL STAY JUST WEST OF THE FORECAST AREA...WITH
THE BEST CHANCE FOR MODERATE RAIN TO BE AS THE COLD FRONT CROSSES
WEDNESDAY NIGHT. THIS SHOULD LIMIT ANY FLOOD THREAT FOR THE PERIOD.

STRONG WARM ADVECTION WILL BE ONGOING THROUGH THE ENTIRE TIME
PERIOD. EVEN WITH CLOUD COVER...HIGH TEMPERATURES ON BOTH TUESDAY
AND WEDNESDAY SHOULD BE WELL ABOVE SEASONAL VALUES WITH HIGHS
LIKELY TO REACH THE MID 50`S.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
CDFNT PASSAGE WILL INITIATE SNOW SHOWER CHANCES ON CHRISTMAS...BUT
LACK OF DEPTH TO THE COLD LYR...DRY ADVCTN IN THE MID LVLS ON THE
SRN PERIMETER OF NWD DIGGING UPR LOW...AND RAPIDLY ENSUING WARM
ADVCTN WL ENSURE A LACK OF SNOW COVER FOR CHRISTMAS.

THE RMNDR OF THE LONG TERM PD IS PROGGED TO FEATURE SEASONAL TEMPS
WITH A LATE WEEK COOLING TREND AS MDLS PROG A REAMPLIFYING FLOW
PTN WITH ERN CONUS TROFFG.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
GENL IMPROVEMENT TO VFR FOR ALL TAF SITES CAN BE EXPECTED FOR THE
TAF PD AS SLY FLOW ALOFT INTENSIFIES OVR LINGER SFC HIGH PRES.

OUTLOOK.../MONDAY THROUGH FRIDAY/...
MIDWRN LOW PRES WL SPREAD RAIN AND RESTRICTIONS OVR AREA PORTS ON
TUESDAY AND WEDNESDAY. IMPROVEMENTS ARE EXPECTED TO BE INITIATED
LTR ON THURSDAY WITH DRY SHRTWV RIDGING.

&&

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

&&

$$








000
FXUS61 KAKQ 220210
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
910 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES OFF THE COAST OVERNIGHT. LOW PRESSURE MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA
COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS THE AREA
WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH MONDAY/...
SFC HI PRES EXTENDING FM ERN NEW ENG TO THE MDATLC RGN WILL CONT
TO WEAKEN OVRNGT. MEANWHILE...WK SFC LO PRES TAKING SHAPE E OF
GA/SC CST AND WILL BEGIN TRACKING NE THROUGH THE NGT. CLDNS
BEGINNING TO SPREAD N INTO SCNTRL VA FM NC. TEMPS HAVE INITIALLY
DROPPED TO OR BLO FREEZING IN SOME PLACES (INLAND). W/ BKN-OVC
CLDNS STARTING TO ARRIVE...TEMPS HAVE ACTUALLY RISEN A FEW DEGS F
FM FVX TO THE NC/VA BORDER. ALSO...PATCHY LGT RA STARTING TO
DEVELOP/MOVE INTO SRN NC.

PROBLEMS OF THE NGT ARE THE INCRSG CLDNS (AND HOW TEMPS RESPOND)
AND ARRIVAL OF PCPN. CNTRL/SRN PORTIONS OF FA WILL LIKELY ACHIEVE
LO TEMPS BY MIDNIGHT...WHILE ACRS THE NNE (WHERE CLDNS SLOWER TO
ARRIVE)...READINGS LIKELY TO DROP AN ADDITIONAL SEVERAL DEGS F.

WHILE TEMPS ACRS NW PIEDMONT HAVE SETTLED BLO FREEZING...LAMP TEMP
GUID ONLY BRING TEMPS BACK TO ARND 32F AS CLDNS AND EVENTUALLY
PCPN ARRIVES LT. ONLY VERY LGT AMTS OF PCPN XPCD...BUT PSBLY JUST
ENOUGH FOR VERY LGT ICING (-ZR) ON UNTREATED/COLDER EXPOSED
SURFACES. CURRENT FREEZING RAIN ADVISORY WILL RMN IN PLACE.
ELSW...WHILE A BIT OF IP PSBL A BEGINNING OF PCPN..ESP ACRS
INTERIOR CNTRL/SRN VA-NE NC...XPCG TEMPS (IF THEY HAVE FALLEN
TO/JUST BLO FREEZING THIS EVE) WILL RISE BACK TO OR ABOVE FREEZING
BY LT TNGT...SO NO ICING PROBLEMS ANTICIPATED. LO TEMPS IN THE
M/U20S ON THE LWR MD ERN SHORE...TO U20S TO U30S ELSW.

WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTER
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTERNOON AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45
EAST TOWARD THE ERN SHORE & SERN CHES BAY...M40S-L50S NE NC.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AN UNSETTLED PERIOD...WITH STRONG SSW FLOW ALOFT AS AN AMPLIFIED
UPPER LEVEL TROUGH SLOWLY TRACKS EAST FROM THE PLAINS STATES MON
NIGHT...THROUGH THE MID ATLC AND SE STATES WED NIGHT. BULK OF LIFT
WILL PUSH OFF TO THE NE OF THE AREA MON NIGHT...BUT LOW LEVELS
REMAIN SATURATED SO WILL MAINTAIN A CHC FOR RAIN WITH AREAS OF
DRIZZLE AND FOG MENTIONED LATER MON NIGHT/TUE. GIVEN AN OVERRUNNING
PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE MON NIGHT THROUGH TUE
NIGHT...HAVE SIDED WITH THE COOLEST OF GUIDANCE FOR HIGH
TEMPERATURES TUE (CLOSEST TO THE ECWMF NUMERICAL GUIDANCE). HIGHS
TUE RANGE FROM THE MID-UPPER 40S ALONG/WEST OF I-95 TO THE MID-
UPPER 50S IN NE NC. SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. GFS/ECMWF IN GOOD AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE
FROM THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS
SOAR INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW
ON WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING
TSTMS ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO
BE MUCH IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL
CAPE) ON WED TO LEAD TO SEVERE WX. THIS WILL NEED TO BE MONITORED
FOR SUBSEQUENT CHANGES. HIGHS WED INTO THE MID-UPPER 60S TO AROUND
70 F (CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS
WED...SHIFTING OFF THE COAST LATER WED EVENING AS THE COLD FRONT
PUSHES THROUGH AND DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO
CHRISTMAS MORNING.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
MAINLY CLEAR SKIES PREVAIL OVER THE AREA EARLY THIS EVENING...WITH
SATELLITE IMAGERY INDICATING AN INCREASE IN HIGH CLOUDS SPREADING
NE INTO THE AREA AT 00Z. CEILINGS IN TO 5KFT TO 10KFT RANGE WILL
OVERSPREAD THE AREA AFTER 03Z. VFR CONDITIONS WILL PREVAIL THROUGH
EARLY MONDAY MORNING. LOW PRESSURE FORMING OFF THE SC COAST ALONG
WITH HIGH PRESSURE WEDGING SOUTH WILL CREATE A SETUP FOR A
COOL/RAINY PERIOD MONDAY MORNING THROUGH MONDAY NIGHT WITH MVFR/IFR
VIS/CIGS EXPECTED. AS THE LOW MOVES NORTH...OVER-RUNNING PRECIP
WILL TRACK S TO N MONDAY MORNING... EVENTUALLY REACHING EVERY AKQ
TAF SITE. MAY BE A VERY BRIEF PERIOD OF IP/FZRA AT KRIC...BUT NOT
CONFIDENT ENOUGH TO INCLUDE IN TAFS. HOWEVER...SOME IP/FZRA
POSSIBLE AT SMALLER AIRPORTS W/NW OF KRIC /E.G. KLKU/KFVX/ MONDAY
MORNING. EXPECT A BRIEF PERIOD OF 15-20 KT WIND GUSTS ALONG THE
COAST AS THE LOW MOVES NORTH AND THE PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT
PASSES THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER
THURSDAY AND FRIDAY. A PERIOD OF GUSTY WINDS EXPECTED WEDNESDAY
AFTERNOON THROUGH MIDDAY THURSDAY AHEAD OF AND BEHIND THE FRONT.

&&

.MARINE...
7 PM UPDATE...HAVE RAISED SCA...MAINLY FOR INCREASING
SEAS...ACROSS THE SRN COASTAL WATERS FROM 18Z MONDAY THROUGH 03Z
TUESDAY. OTHERWISE...VERY FEW CHANGES TO WINDS/SEAS IN THIS
UPDATE.

     AFTERNOON DISCUSSION...LO PRES REMAINS LOCKED IN PLACE OVR THE
NE STATES TNGT AS LO PRES DEVELOPS OFF THE SE CST. THE LO WILL
TRACK UP THE CAROLINA CST ON MON. DESPITE SOME WAA...WITH NE FLOW
AND A TIGHTENING PRES GRADIENT...THINK WINDS WILL MAKE IT INTO THE
15-20 KT RANGE FOR BOTH THE SRN BAY AND SOUND. THEREFORE DECIDED
TO HOIST A SCA FOR THESE LOCATIONS. THINK WINDS WILL BE QUITE
CLOSE TO SCA THRESHOLDS OVR THE NRN BAY AND OCEAN AS WELL...BUT
WITH MORE UNCERTAINTY THERE WILL HOLD OFF FOR NOW AND WILL ISSUE
HAZARD NEXT SHIFT IF NEC. SEAS WILL MAINLY BE 3-4 FT...WITH SOME
SEAS UP TO 5 FT PSBL OVR SRN CST WTRS MON EVENG. THE
AFOREMENTIONED LO WEAKENS ON TUE AS A STRONG COLD FRNT APPROACHES
FM THE W AND WINDS SLOWLY BCM SELY. SCA WINDS EXPECTED BY WED OVR
ALL WTRS EXCEPT THE RIVERS. THE FRNT CROSSES THE REGION WED NGT
INTO THU MORNG...WITH SCA CONDS CONTINUING POST FRNTAL INTO THU.
SEAS WILL BLD TO 5-8 FT WED INTO THU BEFORE SUBSIDING THU NGT.
WAVES OVR THE BAY WILL REACH 3-4 FT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM TO NOON EST MONDAY FOR VAZ048-
     049-060-061.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 10 PM EST MONDAY FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY FROM 4 AM TO 4 PM EST MONDAY FOR ANZ633.
     SMALL CRAFT ADVISORY FROM 1 PM TO 10 PM EST MONDAY FOR ANZ658.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB/LKB
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...DAP/WRS
MARINE...MAS/WRS



























000
FXUS61 KAKQ 220210
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
910 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES OFF THE COAST OVERNIGHT. LOW PRESSURE MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA
COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS THE AREA
WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH MONDAY/...
SFC HI PRES EXTENDING FM ERN NEW ENG TO THE MDATLC RGN WILL CONT
TO WEAKEN OVRNGT. MEANWHILE...WK SFC LO PRES TAKING SHAPE E OF
GA/SC CST AND WILL BEGIN TRACKING NE THROUGH THE NGT. CLDNS
BEGINNING TO SPREAD N INTO SCNTRL VA FM NC. TEMPS HAVE INITIALLY
DROPPED TO OR BLO FREEZING IN SOME PLACES (INLAND). W/ BKN-OVC
CLDNS STARTING TO ARRIVE...TEMPS HAVE ACTUALLY RISEN A FEW DEGS F
FM FVX TO THE NC/VA BORDER. ALSO...PATCHY LGT RA STARTING TO
DEVELOP/MOVE INTO SRN NC.

PROBLEMS OF THE NGT ARE THE INCRSG CLDNS (AND HOW TEMPS RESPOND)
AND ARRIVAL OF PCPN. CNTRL/SRN PORTIONS OF FA WILL LIKELY ACHIEVE
LO TEMPS BY MIDNIGHT...WHILE ACRS THE NNE (WHERE CLDNS SLOWER TO
ARRIVE)...READINGS LIKELY TO DROP AN ADDITIONAL SEVERAL DEGS F.

WHILE TEMPS ACRS NW PIEDMONT HAVE SETTLED BLO FREEZING...LAMP TEMP
GUID ONLY BRING TEMPS BACK TO ARND 32F AS CLDNS AND EVENTUALLY
PCPN ARRIVES LT. ONLY VERY LGT AMTS OF PCPN XPCD...BUT PSBLY JUST
ENOUGH FOR VERY LGT ICING (-ZR) ON UNTREATED/COLDER EXPOSED
SURFACES. CURRENT FREEZING RAIN ADVISORY WILL RMN IN PLACE.
ELSW...WHILE A BIT OF IP PSBL A BEGINNING OF PCPN..ESP ACRS
INTERIOR CNTRL/SRN VA-NE NC...XPCG TEMPS (IF THEY HAVE FALLEN
TO/JUST BLO FREEZING THIS EVE) WILL RISE BACK TO OR ABOVE FREEZING
BY LT TNGT...SO NO ICING PROBLEMS ANTICIPATED. LO TEMPS IN THE
M/U20S ON THE LWR MD ERN SHORE...TO U20S TO U30S ELSW.

WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTER
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTERNOON AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45
EAST TOWARD THE ERN SHORE & SERN CHES BAY...M40S-L50S NE NC.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AN UNSETTLED PERIOD...WITH STRONG SSW FLOW ALOFT AS AN AMPLIFIED
UPPER LEVEL TROUGH SLOWLY TRACKS EAST FROM THE PLAINS STATES MON
NIGHT...THROUGH THE MID ATLC AND SE STATES WED NIGHT. BULK OF LIFT
WILL PUSH OFF TO THE NE OF THE AREA MON NIGHT...BUT LOW LEVELS
REMAIN SATURATED SO WILL MAINTAIN A CHC FOR RAIN WITH AREAS OF
DRIZZLE AND FOG MENTIONED LATER MON NIGHT/TUE. GIVEN AN OVERRUNNING
PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE MON NIGHT THROUGH TUE
NIGHT...HAVE SIDED WITH THE COOLEST OF GUIDANCE FOR HIGH
TEMPERATURES TUE (CLOSEST TO THE ECWMF NUMERICAL GUIDANCE). HIGHS
TUE RANGE FROM THE MID-UPPER 40S ALONG/WEST OF I-95 TO THE MID-
UPPER 50S IN NE NC. SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. GFS/ECMWF IN GOOD AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE
FROM THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS
SOAR INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW
ON WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING
TSTMS ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO
BE MUCH IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL
CAPE) ON WED TO LEAD TO SEVERE WX. THIS WILL NEED TO BE MONITORED
FOR SUBSEQUENT CHANGES. HIGHS WED INTO THE MID-UPPER 60S TO AROUND
70 F (CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS
WED...SHIFTING OFF THE COAST LATER WED EVENING AS THE COLD FRONT
PUSHES THROUGH AND DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO
CHRISTMAS MORNING.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
MAINLY CLEAR SKIES PREVAIL OVER THE AREA EARLY THIS EVENING...WITH
SATELLITE IMAGERY INDICATING AN INCREASE IN HIGH CLOUDS SPREADING
NE INTO THE AREA AT 00Z. CEILINGS IN TO 5KFT TO 10KFT RANGE WILL
OVERSPREAD THE AREA AFTER 03Z. VFR CONDITIONS WILL PREVAIL THROUGH
EARLY MONDAY MORNING. LOW PRESSURE FORMING OFF THE SC COAST ALONG
WITH HIGH PRESSURE WEDGING SOUTH WILL CREATE A SETUP FOR A
COOL/RAINY PERIOD MONDAY MORNING THROUGH MONDAY NIGHT WITH MVFR/IFR
VIS/CIGS EXPECTED. AS THE LOW MOVES NORTH...OVER-RUNNING PRECIP
WILL TRACK S TO N MONDAY MORNING... EVENTUALLY REACHING EVERY AKQ
TAF SITE. MAY BE A VERY BRIEF PERIOD OF IP/FZRA AT KRIC...BUT NOT
CONFIDENT ENOUGH TO INCLUDE IN TAFS. HOWEVER...SOME IP/FZRA
POSSIBLE AT SMALLER AIRPORTS W/NW OF KRIC /E.G. KLKU/KFVX/ MONDAY
MORNING. EXPECT A BRIEF PERIOD OF 15-20 KT WIND GUSTS ALONG THE
COAST AS THE LOW MOVES NORTH AND THE PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT
PASSES THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER
THURSDAY AND FRIDAY. A PERIOD OF GUSTY WINDS EXPECTED WEDNESDAY
AFTERNOON THROUGH MIDDAY THURSDAY AHEAD OF AND BEHIND THE FRONT.

&&

.MARINE...
7 PM UPDATE...HAVE RAISED SCA...MAINLY FOR INCREASING
SEAS...ACROSS THE SRN COASTAL WATERS FROM 18Z MONDAY THROUGH 03Z
TUESDAY. OTHERWISE...VERY FEW CHANGES TO WINDS/SEAS IN THIS
UPDATE.

     AFTERNOON DISCUSSION...LO PRES REMAINS LOCKED IN PLACE OVR THE
NE STATES TNGT AS LO PRES DEVELOPS OFF THE SE CST. THE LO WILL
TRACK UP THE CAROLINA CST ON MON. DESPITE SOME WAA...WITH NE FLOW
AND A TIGHTENING PRES GRADIENT...THINK WINDS WILL MAKE IT INTO THE
15-20 KT RANGE FOR BOTH THE SRN BAY AND SOUND. THEREFORE DECIDED
TO HOIST A SCA FOR THESE LOCATIONS. THINK WINDS WILL BE QUITE
CLOSE TO SCA THRESHOLDS OVR THE NRN BAY AND OCEAN AS WELL...BUT
WITH MORE UNCERTAINTY THERE WILL HOLD OFF FOR NOW AND WILL ISSUE
HAZARD NEXT SHIFT IF NEC. SEAS WILL MAINLY BE 3-4 FT...WITH SOME
SEAS UP TO 5 FT PSBL OVR SRN CST WTRS MON EVENG. THE
AFOREMENTIONED LO WEAKENS ON TUE AS A STRONG COLD FRNT APPROACHES
FM THE W AND WINDS SLOWLY BCM SELY. SCA WINDS EXPECTED BY WED OVR
ALL WTRS EXCEPT THE RIVERS. THE FRNT CROSSES THE REGION WED NGT
INTO THU MORNG...WITH SCA CONDS CONTINUING POST FRNTAL INTO THU.
SEAS WILL BLD TO 5-8 FT WED INTO THU BEFORE SUBSIDING THU NGT.
WAVES OVR THE BAY WILL REACH 3-4 FT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM TO NOON EST MONDAY FOR VAZ048-
     049-060-061.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 10 PM EST MONDAY FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY FROM 4 AM TO 4 PM EST MONDAY FOR ANZ633.
     SMALL CRAFT ADVISORY FROM 1 PM TO 10 PM EST MONDAY FOR ANZ658.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB/LKB
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...DAP/WRS
MARINE...MAS/WRS



























000
FXUS61 KAKQ 220210
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
910 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES OFF THE COAST OVERNIGHT. LOW PRESSURE MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA
COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS THE AREA
WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH MONDAY/...
SFC HI PRES EXTENDING FM ERN NEW ENG TO THE MDATLC RGN WILL CONT
TO WEAKEN OVRNGT. MEANWHILE...WK SFC LO PRES TAKING SHAPE E OF
GA/SC CST AND WILL BEGIN TRACKING NE THROUGH THE NGT. CLDNS
BEGINNING TO SPREAD N INTO SCNTRL VA FM NC. TEMPS HAVE INITIALLY
DROPPED TO OR BLO FREEZING IN SOME PLACES (INLAND). W/ BKN-OVC
CLDNS STARTING TO ARRIVE...TEMPS HAVE ACTUALLY RISEN A FEW DEGS F
FM FVX TO THE NC/VA BORDER. ALSO...PATCHY LGT RA STARTING TO
DEVELOP/MOVE INTO SRN NC.

PROBLEMS OF THE NGT ARE THE INCRSG CLDNS (AND HOW TEMPS RESPOND)
AND ARRIVAL OF PCPN. CNTRL/SRN PORTIONS OF FA WILL LIKELY ACHIEVE
LO TEMPS BY MIDNIGHT...WHILE ACRS THE NNE (WHERE CLDNS SLOWER TO
ARRIVE)...READINGS LIKELY TO DROP AN ADDITIONAL SEVERAL DEGS F.

WHILE TEMPS ACRS NW PIEDMONT HAVE SETTLED BLO FREEZING...LAMP TEMP
GUID ONLY BRING TEMPS BACK TO ARND 32F AS CLDNS AND EVENTUALLY
PCPN ARRIVES LT. ONLY VERY LGT AMTS OF PCPN XPCD...BUT PSBLY JUST
ENOUGH FOR VERY LGT ICING (-ZR) ON UNTREATED/COLDER EXPOSED
SURFACES. CURRENT FREEZING RAIN ADVISORY WILL RMN IN PLACE.
ELSW...WHILE A BIT OF IP PSBL A BEGINNING OF PCPN..ESP ACRS
INTERIOR CNTRL/SRN VA-NE NC...XPCG TEMPS (IF THEY HAVE FALLEN
TO/JUST BLO FREEZING THIS EVE) WILL RISE BACK TO OR ABOVE FREEZING
BY LT TNGT...SO NO ICING PROBLEMS ANTICIPATED. LO TEMPS IN THE
M/U20S ON THE LWR MD ERN SHORE...TO U20S TO U30S ELSW.

WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTER
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTERNOON AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45
EAST TOWARD THE ERN SHORE & SERN CHES BAY...M40S-L50S NE NC.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AN UNSETTLED PERIOD...WITH STRONG SSW FLOW ALOFT AS AN AMPLIFIED
UPPER LEVEL TROUGH SLOWLY TRACKS EAST FROM THE PLAINS STATES MON
NIGHT...THROUGH THE MID ATLC AND SE STATES WED NIGHT. BULK OF LIFT
WILL PUSH OFF TO THE NE OF THE AREA MON NIGHT...BUT LOW LEVELS
REMAIN SATURATED SO WILL MAINTAIN A CHC FOR RAIN WITH AREAS OF
DRIZZLE AND FOG MENTIONED LATER MON NIGHT/TUE. GIVEN AN OVERRUNNING
PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE MON NIGHT THROUGH TUE
NIGHT...HAVE SIDED WITH THE COOLEST OF GUIDANCE FOR HIGH
TEMPERATURES TUE (CLOSEST TO THE ECWMF NUMERICAL GUIDANCE). HIGHS
TUE RANGE FROM THE MID-UPPER 40S ALONG/WEST OF I-95 TO THE MID-
UPPER 50S IN NE NC. SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. GFS/ECMWF IN GOOD AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE
FROM THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS
SOAR INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW
ON WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING
TSTMS ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO
BE MUCH IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL
CAPE) ON WED TO LEAD TO SEVERE WX. THIS WILL NEED TO BE MONITORED
FOR SUBSEQUENT CHANGES. HIGHS WED INTO THE MID-UPPER 60S TO AROUND
70 F (CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS
WED...SHIFTING OFF THE COAST LATER WED EVENING AS THE COLD FRONT
PUSHES THROUGH AND DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO
CHRISTMAS MORNING.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
MAINLY CLEAR SKIES PREVAIL OVER THE AREA EARLY THIS EVENING...WITH
SATELLITE IMAGERY INDICATING AN INCREASE IN HIGH CLOUDS SPREADING
NE INTO THE AREA AT 00Z. CEILINGS IN TO 5KFT TO 10KFT RANGE WILL
OVERSPREAD THE AREA AFTER 03Z. VFR CONDITIONS WILL PREVAIL THROUGH
EARLY MONDAY MORNING. LOW PRESSURE FORMING OFF THE SC COAST ALONG
WITH HIGH PRESSURE WEDGING SOUTH WILL CREATE A SETUP FOR A
COOL/RAINY PERIOD MONDAY MORNING THROUGH MONDAY NIGHT WITH MVFR/IFR
VIS/CIGS EXPECTED. AS THE LOW MOVES NORTH...OVER-RUNNING PRECIP
WILL TRACK S TO N MONDAY MORNING... EVENTUALLY REACHING EVERY AKQ
TAF SITE. MAY BE A VERY BRIEF PERIOD OF IP/FZRA AT KRIC...BUT NOT
CONFIDENT ENOUGH TO INCLUDE IN TAFS. HOWEVER...SOME IP/FZRA
POSSIBLE AT SMALLER AIRPORTS W/NW OF KRIC /E.G. KLKU/KFVX/ MONDAY
MORNING. EXPECT A BRIEF PERIOD OF 15-20 KT WIND GUSTS ALONG THE
COAST AS THE LOW MOVES NORTH AND THE PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT
PASSES THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER
THURSDAY AND FRIDAY. A PERIOD OF GUSTY WINDS EXPECTED WEDNESDAY
AFTERNOON THROUGH MIDDAY THURSDAY AHEAD OF AND BEHIND THE FRONT.

&&

.MARINE...
7 PM UPDATE...HAVE RAISED SCA...MAINLY FOR INCREASING
SEAS...ACROSS THE SRN COASTAL WATERS FROM 18Z MONDAY THROUGH 03Z
TUESDAY. OTHERWISE...VERY FEW CHANGES TO WINDS/SEAS IN THIS
UPDATE.

     AFTERNOON DISCUSSION...LO PRES REMAINS LOCKED IN PLACE OVR THE
NE STATES TNGT AS LO PRES DEVELOPS OFF THE SE CST. THE LO WILL
TRACK UP THE CAROLINA CST ON MON. DESPITE SOME WAA...WITH NE FLOW
AND A TIGHTENING PRES GRADIENT...THINK WINDS WILL MAKE IT INTO THE
15-20 KT RANGE FOR BOTH THE SRN BAY AND SOUND. THEREFORE DECIDED
TO HOIST A SCA FOR THESE LOCATIONS. THINK WINDS WILL BE QUITE
CLOSE TO SCA THRESHOLDS OVR THE NRN BAY AND OCEAN AS WELL...BUT
WITH MORE UNCERTAINTY THERE WILL HOLD OFF FOR NOW AND WILL ISSUE
HAZARD NEXT SHIFT IF NEC. SEAS WILL MAINLY BE 3-4 FT...WITH SOME
SEAS UP TO 5 FT PSBL OVR SRN CST WTRS MON EVENG. THE
AFOREMENTIONED LO WEAKENS ON TUE AS A STRONG COLD FRNT APPROACHES
FM THE W AND WINDS SLOWLY BCM SELY. SCA WINDS EXPECTED BY WED OVR
ALL WTRS EXCEPT THE RIVERS. THE FRNT CROSSES THE REGION WED NGT
INTO THU MORNG...WITH SCA CONDS CONTINUING POST FRNTAL INTO THU.
SEAS WILL BLD TO 5-8 FT WED INTO THU BEFORE SUBSIDING THU NGT.
WAVES OVR THE BAY WILL REACH 3-4 FT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM TO NOON EST MONDAY FOR VAZ048-
     049-060-061.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 10 PM EST MONDAY FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY FROM 4 AM TO 4 PM EST MONDAY FOR ANZ633.
     SMALL CRAFT ADVISORY FROM 1 PM TO 10 PM EST MONDAY FOR ANZ658.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB/LKB
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...DAP/WRS
MARINE...MAS/WRS



























000
FXUS61 KAKQ 220210
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
910 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES OFF THE COAST OVERNIGHT. LOW PRESSURE MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA
COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS THE AREA
WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH MONDAY/...
SFC HI PRES EXTENDING FM ERN NEW ENG TO THE MDATLC RGN WILL CONT
TO WEAKEN OVRNGT. MEANWHILE...WK SFC LO PRES TAKING SHAPE E OF
GA/SC CST AND WILL BEGIN TRACKING NE THROUGH THE NGT. CLDNS
BEGINNING TO SPREAD N INTO SCNTRL VA FM NC. TEMPS HAVE INITIALLY
DROPPED TO OR BLO FREEZING IN SOME PLACES (INLAND). W/ BKN-OVC
CLDNS STARTING TO ARRIVE...TEMPS HAVE ACTUALLY RISEN A FEW DEGS F
FM FVX TO THE NC/VA BORDER. ALSO...PATCHY LGT RA STARTING TO
DEVELOP/MOVE INTO SRN NC.

PROBLEMS OF THE NGT ARE THE INCRSG CLDNS (AND HOW TEMPS RESPOND)
AND ARRIVAL OF PCPN. CNTRL/SRN PORTIONS OF FA WILL LIKELY ACHIEVE
LO TEMPS BY MIDNIGHT...WHILE ACRS THE NNE (WHERE CLDNS SLOWER TO
ARRIVE)...READINGS LIKELY TO DROP AN ADDITIONAL SEVERAL DEGS F.

WHILE TEMPS ACRS NW PIEDMONT HAVE SETTLED BLO FREEZING...LAMP TEMP
GUID ONLY BRING TEMPS BACK TO ARND 32F AS CLDNS AND EVENTUALLY
PCPN ARRIVES LT. ONLY VERY LGT AMTS OF PCPN XPCD...BUT PSBLY JUST
ENOUGH FOR VERY LGT ICING (-ZR) ON UNTREATED/COLDER EXPOSED
SURFACES. CURRENT FREEZING RAIN ADVISORY WILL RMN IN PLACE.
ELSW...WHILE A BIT OF IP PSBL A BEGINNING OF PCPN..ESP ACRS
INTERIOR CNTRL/SRN VA-NE NC...XPCG TEMPS (IF THEY HAVE FALLEN
TO/JUST BLO FREEZING THIS EVE) WILL RISE BACK TO OR ABOVE FREEZING
BY LT TNGT...SO NO ICING PROBLEMS ANTICIPATED. LO TEMPS IN THE
M/U20S ON THE LWR MD ERN SHORE...TO U20S TO U30S ELSW.

WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTER
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTERNOON AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45
EAST TOWARD THE ERN SHORE & SERN CHES BAY...M40S-L50S NE NC.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AN UNSETTLED PERIOD...WITH STRONG SSW FLOW ALOFT AS AN AMPLIFIED
UPPER LEVEL TROUGH SLOWLY TRACKS EAST FROM THE PLAINS STATES MON
NIGHT...THROUGH THE MID ATLC AND SE STATES WED NIGHT. BULK OF LIFT
WILL PUSH OFF TO THE NE OF THE AREA MON NIGHT...BUT LOW LEVELS
REMAIN SATURATED SO WILL MAINTAIN A CHC FOR RAIN WITH AREAS OF
DRIZZLE AND FOG MENTIONED LATER MON NIGHT/TUE. GIVEN AN OVERRUNNING
PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE MON NIGHT THROUGH TUE
NIGHT...HAVE SIDED WITH THE COOLEST OF GUIDANCE FOR HIGH
TEMPERATURES TUE (CLOSEST TO THE ECWMF NUMERICAL GUIDANCE). HIGHS
TUE RANGE FROM THE MID-UPPER 40S ALONG/WEST OF I-95 TO THE MID-
UPPER 50S IN NE NC. SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. GFS/ECMWF IN GOOD AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE
FROM THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS
SOAR INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW
ON WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING
TSTMS ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO
BE MUCH IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL
CAPE) ON WED TO LEAD TO SEVERE WX. THIS WILL NEED TO BE MONITORED
FOR SUBSEQUENT CHANGES. HIGHS WED INTO THE MID-UPPER 60S TO AROUND
70 F (CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS
WED...SHIFTING OFF THE COAST LATER WED EVENING AS THE COLD FRONT
PUSHES THROUGH AND DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO
CHRISTMAS MORNING.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
MAINLY CLEAR SKIES PREVAIL OVER THE AREA EARLY THIS EVENING...WITH
SATELLITE IMAGERY INDICATING AN INCREASE IN HIGH CLOUDS SPREADING
NE INTO THE AREA AT 00Z. CEILINGS IN TO 5KFT TO 10KFT RANGE WILL
OVERSPREAD THE AREA AFTER 03Z. VFR CONDITIONS WILL PREVAIL THROUGH
EARLY MONDAY MORNING. LOW PRESSURE FORMING OFF THE SC COAST ALONG
WITH HIGH PRESSURE WEDGING SOUTH WILL CREATE A SETUP FOR A
COOL/RAINY PERIOD MONDAY MORNING THROUGH MONDAY NIGHT WITH MVFR/IFR
VIS/CIGS EXPECTED. AS THE LOW MOVES NORTH...OVER-RUNNING PRECIP
WILL TRACK S TO N MONDAY MORNING... EVENTUALLY REACHING EVERY AKQ
TAF SITE. MAY BE A VERY BRIEF PERIOD OF IP/FZRA AT KRIC...BUT NOT
CONFIDENT ENOUGH TO INCLUDE IN TAFS. HOWEVER...SOME IP/FZRA
POSSIBLE AT SMALLER AIRPORTS W/NW OF KRIC /E.G. KLKU/KFVX/ MONDAY
MORNING. EXPECT A BRIEF PERIOD OF 15-20 KT WIND GUSTS ALONG THE
COAST AS THE LOW MOVES NORTH AND THE PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT
PASSES THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER
THURSDAY AND FRIDAY. A PERIOD OF GUSTY WINDS EXPECTED WEDNESDAY
AFTERNOON THROUGH MIDDAY THURSDAY AHEAD OF AND BEHIND THE FRONT.

&&

.MARINE...
7 PM UPDATE...HAVE RAISED SCA...MAINLY FOR INCREASING
SEAS...ACROSS THE SRN COASTAL WATERS FROM 18Z MONDAY THROUGH 03Z
TUESDAY. OTHERWISE...VERY FEW CHANGES TO WINDS/SEAS IN THIS
UPDATE.

     AFTERNOON DISCUSSION...LO PRES REMAINS LOCKED IN PLACE OVR THE
NE STATES TNGT AS LO PRES DEVELOPS OFF THE SE CST. THE LO WILL
TRACK UP THE CAROLINA CST ON MON. DESPITE SOME WAA...WITH NE FLOW
AND A TIGHTENING PRES GRADIENT...THINK WINDS WILL MAKE IT INTO THE
15-20 KT RANGE FOR BOTH THE SRN BAY AND SOUND. THEREFORE DECIDED
TO HOIST A SCA FOR THESE LOCATIONS. THINK WINDS WILL BE QUITE
CLOSE TO SCA THRESHOLDS OVR THE NRN BAY AND OCEAN AS WELL...BUT
WITH MORE UNCERTAINTY THERE WILL HOLD OFF FOR NOW AND WILL ISSUE
HAZARD NEXT SHIFT IF NEC. SEAS WILL MAINLY BE 3-4 FT...WITH SOME
SEAS UP TO 5 FT PSBL OVR SRN CST WTRS MON EVENG. THE
AFOREMENTIONED LO WEAKENS ON TUE AS A STRONG COLD FRNT APPROACHES
FM THE W AND WINDS SLOWLY BCM SELY. SCA WINDS EXPECTED BY WED OVR
ALL WTRS EXCEPT THE RIVERS. THE FRNT CROSSES THE REGION WED NGT
INTO THU MORNG...WITH SCA CONDS CONTINUING POST FRNTAL INTO THU.
SEAS WILL BLD TO 5-8 FT WED INTO THU BEFORE SUBSIDING THU NGT.
WAVES OVR THE BAY WILL REACH 3-4 FT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM TO NOON EST MONDAY FOR VAZ048-
     049-060-061.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 10 PM EST MONDAY FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY FROM 4 AM TO 4 PM EST MONDAY FOR ANZ633.
     SMALL CRAFT ADVISORY FROM 1 PM TO 10 PM EST MONDAY FOR ANZ658.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB/LKB
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...DAP/WRS
MARINE...MAS/WRS



























000
FXUS61 KAKQ 220210
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
910 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES OFF THE COAST OVERNIGHT. LOW PRESSURE MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA
COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS THE AREA
WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH MONDAY/...
SFC HI PRES EXTENDING FM ERN NEW ENG TO THE MDATLC RGN WILL CONT
TO WEAKEN OVRNGT. MEANWHILE...WK SFC LO PRES TAKING SHAPE E OF
GA/SC CST AND WILL BEGIN TRACKING NE THROUGH THE NGT. CLDNS
BEGINNING TO SPREAD N INTO SCNTRL VA FM NC. TEMPS HAVE INITIALLY
DROPPED TO OR BLO FREEZING IN SOME PLACES (INLAND). W/ BKN-OVC
CLDNS STARTING TO ARRIVE...TEMPS HAVE ACTUALLY RISEN A FEW DEGS F
FM FVX TO THE NC/VA BORDER. ALSO...PATCHY LGT RA STARTING TO
DEVELOP/MOVE INTO SRN NC.

PROBLEMS OF THE NGT ARE THE INCRSG CLDNS (AND HOW TEMPS RESPOND)
AND ARRIVAL OF PCPN. CNTRL/SRN PORTIONS OF FA WILL LIKELY ACHIEVE
LO TEMPS BY MIDNIGHT...WHILE ACRS THE NNE (WHERE CLDNS SLOWER TO
ARRIVE)...READINGS LIKELY TO DROP AN ADDITIONAL SEVERAL DEGS F.

WHILE TEMPS ACRS NW PIEDMONT HAVE SETTLED BLO FREEZING...LAMP TEMP
GUID ONLY BRING TEMPS BACK TO ARND 32F AS CLDNS AND EVENTUALLY
PCPN ARRIVES LT. ONLY VERY LGT AMTS OF PCPN XPCD...BUT PSBLY JUST
ENOUGH FOR VERY LGT ICING (-ZR) ON UNTREATED/COLDER EXPOSED
SURFACES. CURRENT FREEZING RAIN ADVISORY WILL RMN IN PLACE.
ELSW...WHILE A BIT OF IP PSBL A BEGINNING OF PCPN..ESP ACRS
INTERIOR CNTRL/SRN VA-NE NC...XPCG TEMPS (IF THEY HAVE FALLEN
TO/JUST BLO FREEZING THIS EVE) WILL RISE BACK TO OR ABOVE FREEZING
BY LT TNGT...SO NO ICING PROBLEMS ANTICIPATED. LO TEMPS IN THE
M/U20S ON THE LWR MD ERN SHORE...TO U20S TO U30S ELSW.

WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTER
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTERNOON AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45
EAST TOWARD THE ERN SHORE & SERN CHES BAY...M40S-L50S NE NC.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AN UNSETTLED PERIOD...WITH STRONG SSW FLOW ALOFT AS AN AMPLIFIED
UPPER LEVEL TROUGH SLOWLY TRACKS EAST FROM THE PLAINS STATES MON
NIGHT...THROUGH THE MID ATLC AND SE STATES WED NIGHT. BULK OF LIFT
WILL PUSH OFF TO THE NE OF THE AREA MON NIGHT...BUT LOW LEVELS
REMAIN SATURATED SO WILL MAINTAIN A CHC FOR RAIN WITH AREAS OF
DRIZZLE AND FOG MENTIONED LATER MON NIGHT/TUE. GIVEN AN OVERRUNNING
PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE MON NIGHT THROUGH TUE
NIGHT...HAVE SIDED WITH THE COOLEST OF GUIDANCE FOR HIGH
TEMPERATURES TUE (CLOSEST TO THE ECWMF NUMERICAL GUIDANCE). HIGHS
TUE RANGE FROM THE MID-UPPER 40S ALONG/WEST OF I-95 TO THE MID-
UPPER 50S IN NE NC. SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. GFS/ECMWF IN GOOD AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE
FROM THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS
SOAR INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW
ON WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING
TSTMS ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO
BE MUCH IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL
CAPE) ON WED TO LEAD TO SEVERE WX. THIS WILL NEED TO BE MONITORED
FOR SUBSEQUENT CHANGES. HIGHS WED INTO THE MID-UPPER 60S TO AROUND
70 F (CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS
WED...SHIFTING OFF THE COAST LATER WED EVENING AS THE COLD FRONT
PUSHES THROUGH AND DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO
CHRISTMAS MORNING.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
MAINLY CLEAR SKIES PREVAIL OVER THE AREA EARLY THIS EVENING...WITH
SATELLITE IMAGERY INDICATING AN INCREASE IN HIGH CLOUDS SPREADING
NE INTO THE AREA AT 00Z. CEILINGS IN TO 5KFT TO 10KFT RANGE WILL
OVERSPREAD THE AREA AFTER 03Z. VFR CONDITIONS WILL PREVAIL THROUGH
EARLY MONDAY MORNING. LOW PRESSURE FORMING OFF THE SC COAST ALONG
WITH HIGH PRESSURE WEDGING SOUTH WILL CREATE A SETUP FOR A
COOL/RAINY PERIOD MONDAY MORNING THROUGH MONDAY NIGHT WITH MVFR/IFR
VIS/CIGS EXPECTED. AS THE LOW MOVES NORTH...OVER-RUNNING PRECIP
WILL TRACK S TO N MONDAY MORNING... EVENTUALLY REACHING EVERY AKQ
TAF SITE. MAY BE A VERY BRIEF PERIOD OF IP/FZRA AT KRIC...BUT NOT
CONFIDENT ENOUGH TO INCLUDE IN TAFS. HOWEVER...SOME IP/FZRA
POSSIBLE AT SMALLER AIRPORTS W/NW OF KRIC /E.G. KLKU/KFVX/ MONDAY
MORNING. EXPECT A BRIEF PERIOD OF 15-20 KT WIND GUSTS ALONG THE
COAST AS THE LOW MOVES NORTH AND THE PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT
PASSES THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER
THURSDAY AND FRIDAY. A PERIOD OF GUSTY WINDS EXPECTED WEDNESDAY
AFTERNOON THROUGH MIDDAY THURSDAY AHEAD OF AND BEHIND THE FRONT.

&&

.MARINE...
7 PM UPDATE...HAVE RAISED SCA...MAINLY FOR INCREASING
SEAS...ACROSS THE SRN COASTAL WATERS FROM 18Z MONDAY THROUGH 03Z
TUESDAY. OTHERWISE...VERY FEW CHANGES TO WINDS/SEAS IN THIS
UPDATE.

     AFTERNOON DISCUSSION...LO PRES REMAINS LOCKED IN PLACE OVR THE
NE STATES TNGT AS LO PRES DEVELOPS OFF THE SE CST. THE LO WILL
TRACK UP THE CAROLINA CST ON MON. DESPITE SOME WAA...WITH NE FLOW
AND A TIGHTENING PRES GRADIENT...THINK WINDS WILL MAKE IT INTO THE
15-20 KT RANGE FOR BOTH THE SRN BAY AND SOUND. THEREFORE DECIDED
TO HOIST A SCA FOR THESE LOCATIONS. THINK WINDS WILL BE QUITE
CLOSE TO SCA THRESHOLDS OVR THE NRN BAY AND OCEAN AS WELL...BUT
WITH MORE UNCERTAINTY THERE WILL HOLD OFF FOR NOW AND WILL ISSUE
HAZARD NEXT SHIFT IF NEC. SEAS WILL MAINLY BE 3-4 FT...WITH SOME
SEAS UP TO 5 FT PSBL OVR SRN CST WTRS MON EVENG. THE
AFOREMENTIONED LO WEAKENS ON TUE AS A STRONG COLD FRNT APPROACHES
FM THE W AND WINDS SLOWLY BCM SELY. SCA WINDS EXPECTED BY WED OVR
ALL WTRS EXCEPT THE RIVERS. THE FRNT CROSSES THE REGION WED NGT
INTO THU MORNG...WITH SCA CONDS CONTINUING POST FRNTAL INTO THU.
SEAS WILL BLD TO 5-8 FT WED INTO THU BEFORE SUBSIDING THU NGT.
WAVES OVR THE BAY WILL REACH 3-4 FT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM TO NOON EST MONDAY FOR VAZ048-
     049-060-061.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 10 PM EST MONDAY FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY FROM 4 AM TO 4 PM EST MONDAY FOR ANZ633.
     SMALL CRAFT ADVISORY FROM 1 PM TO 10 PM EST MONDAY FOR ANZ658.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB/LKB
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...DAP/WRS
MARINE...MAS/WRS



























000
FXUS61 KAKQ 220210
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
910 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES OFF THE COAST OVERNIGHT. LOW PRESSURE MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA
COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS THE AREA
WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH MONDAY/...
SFC HI PRES EXTENDING FM ERN NEW ENG TO THE MDATLC RGN WILL CONT
TO WEAKEN OVRNGT. MEANWHILE...WK SFC LO PRES TAKING SHAPE E OF
GA/SC CST AND WILL BEGIN TRACKING NE THROUGH THE NGT. CLDNS
BEGINNING TO SPREAD N INTO SCNTRL VA FM NC. TEMPS HAVE INITIALLY
DROPPED TO OR BLO FREEZING IN SOME PLACES (INLAND). W/ BKN-OVC
CLDNS STARTING TO ARRIVE...TEMPS HAVE ACTUALLY RISEN A FEW DEGS F
FM FVX TO THE NC/VA BORDER. ALSO...PATCHY LGT RA STARTING TO
DEVELOP/MOVE INTO SRN NC.

PROBLEMS OF THE NGT ARE THE INCRSG CLDNS (AND HOW TEMPS RESPOND)
AND ARRIVAL OF PCPN. CNTRL/SRN PORTIONS OF FA WILL LIKELY ACHIEVE
LO TEMPS BY MIDNIGHT...WHILE ACRS THE NNE (WHERE CLDNS SLOWER TO
ARRIVE)...READINGS LIKELY TO DROP AN ADDITIONAL SEVERAL DEGS F.

WHILE TEMPS ACRS NW PIEDMONT HAVE SETTLED BLO FREEZING...LAMP TEMP
GUID ONLY BRING TEMPS BACK TO ARND 32F AS CLDNS AND EVENTUALLY
PCPN ARRIVES LT. ONLY VERY LGT AMTS OF PCPN XPCD...BUT PSBLY JUST
ENOUGH FOR VERY LGT ICING (-ZR) ON UNTREATED/COLDER EXPOSED
SURFACES. CURRENT FREEZING RAIN ADVISORY WILL RMN IN PLACE.
ELSW...WHILE A BIT OF IP PSBL A BEGINNING OF PCPN..ESP ACRS
INTERIOR CNTRL/SRN VA-NE NC...XPCG TEMPS (IF THEY HAVE FALLEN
TO/JUST BLO FREEZING THIS EVE) WILL RISE BACK TO OR ABOVE FREEZING
BY LT TNGT...SO NO ICING PROBLEMS ANTICIPATED. LO TEMPS IN THE
M/U20S ON THE LWR MD ERN SHORE...TO U20S TO U30S ELSW.

WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTER
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTERNOON AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45
EAST TOWARD THE ERN SHORE & SERN CHES BAY...M40S-L50S NE NC.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AN UNSETTLED PERIOD...WITH STRONG SSW FLOW ALOFT AS AN AMPLIFIED
UPPER LEVEL TROUGH SLOWLY TRACKS EAST FROM THE PLAINS STATES MON
NIGHT...THROUGH THE MID ATLC AND SE STATES WED NIGHT. BULK OF LIFT
WILL PUSH OFF TO THE NE OF THE AREA MON NIGHT...BUT LOW LEVELS
REMAIN SATURATED SO WILL MAINTAIN A CHC FOR RAIN WITH AREAS OF
DRIZZLE AND FOG MENTIONED LATER MON NIGHT/TUE. GIVEN AN OVERRUNNING
PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE MON NIGHT THROUGH TUE
NIGHT...HAVE SIDED WITH THE COOLEST OF GUIDANCE FOR HIGH
TEMPERATURES TUE (CLOSEST TO THE ECWMF NUMERICAL GUIDANCE). HIGHS
TUE RANGE FROM THE MID-UPPER 40S ALONG/WEST OF I-95 TO THE MID-
UPPER 50S IN NE NC. SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. GFS/ECMWF IN GOOD AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE
FROM THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS
SOAR INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW
ON WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING
TSTMS ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO
BE MUCH IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL
CAPE) ON WED TO LEAD TO SEVERE WX. THIS WILL NEED TO BE MONITORED
FOR SUBSEQUENT CHANGES. HIGHS WED INTO THE MID-UPPER 60S TO AROUND
70 F (CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS
WED...SHIFTING OFF THE COAST LATER WED EVENING AS THE COLD FRONT
PUSHES THROUGH AND DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO
CHRISTMAS MORNING.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
MAINLY CLEAR SKIES PREVAIL OVER THE AREA EARLY THIS EVENING...WITH
SATELLITE IMAGERY INDICATING AN INCREASE IN HIGH CLOUDS SPREADING
NE INTO THE AREA AT 00Z. CEILINGS IN TO 5KFT TO 10KFT RANGE WILL
OVERSPREAD THE AREA AFTER 03Z. VFR CONDITIONS WILL PREVAIL THROUGH
EARLY MONDAY MORNING. LOW PRESSURE FORMING OFF THE SC COAST ALONG
WITH HIGH PRESSURE WEDGING SOUTH WILL CREATE A SETUP FOR A
COOL/RAINY PERIOD MONDAY MORNING THROUGH MONDAY NIGHT WITH MVFR/IFR
VIS/CIGS EXPECTED. AS THE LOW MOVES NORTH...OVER-RUNNING PRECIP
WILL TRACK S TO N MONDAY MORNING... EVENTUALLY REACHING EVERY AKQ
TAF SITE. MAY BE A VERY BRIEF PERIOD OF IP/FZRA AT KRIC...BUT NOT
CONFIDENT ENOUGH TO INCLUDE IN TAFS. HOWEVER...SOME IP/FZRA
POSSIBLE AT SMALLER AIRPORTS W/NW OF KRIC /E.G. KLKU/KFVX/ MONDAY
MORNING. EXPECT A BRIEF PERIOD OF 15-20 KT WIND GUSTS ALONG THE
COAST AS THE LOW MOVES NORTH AND THE PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT
PASSES THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER
THURSDAY AND FRIDAY. A PERIOD OF GUSTY WINDS EXPECTED WEDNESDAY
AFTERNOON THROUGH MIDDAY THURSDAY AHEAD OF AND BEHIND THE FRONT.

&&

.MARINE...
7 PM UPDATE...HAVE RAISED SCA...MAINLY FOR INCREASING
SEAS...ACROSS THE SRN COASTAL WATERS FROM 18Z MONDAY THROUGH 03Z
TUESDAY. OTHERWISE...VERY FEW CHANGES TO WINDS/SEAS IN THIS
UPDATE.

     AFTERNOON DISCUSSION...LO PRES REMAINS LOCKED IN PLACE OVR THE
NE STATES TNGT AS LO PRES DEVELOPS OFF THE SE CST. THE LO WILL
TRACK UP THE CAROLINA CST ON MON. DESPITE SOME WAA...WITH NE FLOW
AND A TIGHTENING PRES GRADIENT...THINK WINDS WILL MAKE IT INTO THE
15-20 KT RANGE FOR BOTH THE SRN BAY AND SOUND. THEREFORE DECIDED
TO HOIST A SCA FOR THESE LOCATIONS. THINK WINDS WILL BE QUITE
CLOSE TO SCA THRESHOLDS OVR THE NRN BAY AND OCEAN AS WELL...BUT
WITH MORE UNCERTAINTY THERE WILL HOLD OFF FOR NOW AND WILL ISSUE
HAZARD NEXT SHIFT IF NEC. SEAS WILL MAINLY BE 3-4 FT...WITH SOME
SEAS UP TO 5 FT PSBL OVR SRN CST WTRS MON EVENG. THE
AFOREMENTIONED LO WEAKENS ON TUE AS A STRONG COLD FRNT APPROACHES
FM THE W AND WINDS SLOWLY BCM SELY. SCA WINDS EXPECTED BY WED OVR
ALL WTRS EXCEPT THE RIVERS. THE FRNT CROSSES THE REGION WED NGT
INTO THU MORNG...WITH SCA CONDS CONTINUING POST FRNTAL INTO THU.
SEAS WILL BLD TO 5-8 FT WED INTO THU BEFORE SUBSIDING THU NGT.
WAVES OVR THE BAY WILL REACH 3-4 FT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM TO NOON EST MONDAY FOR VAZ048-
     049-060-061.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 10 PM EST MONDAY FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY FROM 4 AM TO 4 PM EST MONDAY FOR ANZ633.
     SMALL CRAFT ADVISORY FROM 1 PM TO 10 PM EST MONDAY FOR ANZ658.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB/LKB
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...DAP/WRS
MARINE...MAS/WRS




























000
FXUS61 KAKQ 212346
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
646 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES OFF THE COAST TONIGHT. LOW PRESSURE MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA
COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS THE AREA
WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH MONDAY/...
LATEST ANALYSIS DEPICTS ~1030 MB SFC HIGH PRESSURE CENTERED OVER
ERN CANADA...RIDGING DOWN INTO THE MID ATLC REGION. A TROUGH OF
LOW PRESSURE IS IN PLACE OFF THE COAST OF GA/SC...AND IS PROGGED
TO SHIFT SLOWLY N/E OVERNIGHT. SKIES HAVE CLEARED OUT OVER THE
LOCAL AREA WITH TEMPERATURES INTO THE 40S TO LOWER 50S.

FOR TONIGHT...MAIN CONCERN WILL BE POTENTIAL FOR WINTRY MIX
(PRIMARILY ZR) OVER FAR WRN PORTIONS OF THE CWA. HAVE ISSUED A
FREEZING RAIN ADVISORY FOR THE 4 CLIMO FAVORED COUNTIES ACRS THE
FAR WRN PORTION OF THE CWA (LOUISA/FLUVANNA/CUMBERLAND/PRINCE
EDWARD). OVERALL PATTERN IS NOT FAVORABLE FOR MUCH IMPACT ANYWHERE
ELSE IN THE CWA (SFC HIGH TOO WEAK/PUSHING TOO FAR EAST). THIS
WILL BE A "MINIMAL IMPACT" ADVISORY FOR THE MOST PART...AS BUFKIT
SOUNDINGS (ESPECIALLY THE GFS) SHOW LIMTED SATURATION THROUGH THE
DENDRITIC GROWTH LAYER THROUGH THE DURATION OF THE EVENT (HEAVIER
PRECIP STAYING EAST WHERE IT WILL BE ALL RAIN). STILL ENOUGH
SUPPORT FOR ZR AS MAIN PTYPE (RATHER THAN SLEET) AND IF THE NAM/EC
SCENARIO VERIFIES...THINK THERE IS A GOOD CHC FOR AT LEAST A FEW
HUNDREDTHS OF AN INCH OF ICE ACCUMULATION. DESPITE SOME TIMING
DIFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS
THE AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN
E OF I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A
NARROW LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE
PIEDMONT. THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF
I95 AND N OF RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS
NEAR FREEZING. QPF LOOKS MINIMAL LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTER
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTERNOON AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45 EAST
TOWARD THE ERN SHORE & SERN CHES BAY... M40S-L50S NE NC.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AN UNSETTLED PERIOD...WITH STRONG SSW FLOW ALOFT AS AN AMPLIFIED
UPPER LEVEL TROUGH SLOWLY TRACKS EAST FROM THE PLAINS STATES MON
NIGHT...THROUGH THE MID ATLC AND SE STATES WED NIGHT. BULK OF LIFT
WILL PUSH OFF TO THE NE OF THE AREA MON NIGHT...BUT LOW LEVELS
REMAIN SATURATED SO WILL MAINTAIN A CHC FOR RAIN WITH AREAS OF
DRIZZLE AND FOG MENTIONED LATER MON NIGHT/TUE. GIVEN AN OVERRUNNING
PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE MON NIGHT THROUGH TUE
NIGHT...HAVE SIDED WITH THE COOLEST OF GUIDANCE FOR HIGH
TEMPERATURES TUE (CLOSEST TO THE ECWMF NUMERICAL GUIDANCE). HIGHS
TUE RANGE FROM THE MID-UPPER 40S ALONG/WEST OF I-95 TO THE MID-
UPPER 50S IN NE NC. SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. GFS/ECMWF IN GOOD AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE
FROM THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS
SOAR INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW
ON WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING
TSTMS ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO
BE MUCH IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL
CAPE) ON WED TO LEAD TO SEVERE WX. THIS WILL NEED TO BE MONITORED
FOR SUBSEQUENT CHANGES. HIGHS WED INTO THE MID-UPPER 60S TO AROUND
70 F (CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS
WED...SHIFTING OFF THE COAST LATER WED EVENING AS THE COLD FRONT
PUSHES THROUGH AND DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO
CHRISTMAS MORNING.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
MAINLY CLEAR SKIES PREVAIL OVER THE AREA EARLY THIS EVENING...WITH
SATELLITE IMAGERY INDICATING AN INCREASE IN HIGH CLOUDS SPREADING
NE INTO THE AREA AT 00Z. CEILINGS IN TO 5KFT TO 10KFT RANGE WILL
OVERSPREAD THE AREA AFTER 03Z. VFR CONDITIONS WILL PREVAIL THROUGH
EARLY MONDAY MORNING. LOW PRESSURE FORMING OFF THE SC COAST ALONG
WITH HIGH PRESSURE WEDGING SOUTH WILL CREATE A SETUP FOR A
COOL/RAINY PERIOD MONDAY MORNING THROUGH MONDAY NIGHT WITH MVFR/IFR
VIS/CIGS EXPECTED. AS THE LOW MOVES NORTH...OVER-RUNNING PRECIP
WILL TRACK S TO N MONDAY MORNING... EVENTUALLY REACHING EVERY AKQ
TAF SITE. MAY BE A VERY BRIEF PERIOD OF IP/FZRA AT KRIC...BUT NOT
CONFIDENT ENOUGH TO INCLUDE IN TAFS. HOWEVER...SOME IP/FZRA
POSSIBLE AT SMALLER AIRPORTS W/NW OF KRIC /E.G. KLKU/KFVX/ MONDAY
MORNING. EXPECT A BRIEF PERIOD OF 15-20 KT WIND GUSTS ALONG THE
COAST AS THE LOW MOVES NORTH AND THE PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT
PASSES THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER
THURSDAY AND FRIDAY. A PERIOD OF GUSTY WINDS EXPECTED WEDNESDAY
AFTERNOON THROUGH MIDDAY THURSDAY AHEAD OF AND BEHIND THE FRONT.

&&

.MARINE...
7 PM UPDATE...HAVE RAISED SCA...MAINLY FOR INCREASING
SEAS...ACROSS THE SRN COASTAL WATERS FROM 18Z MONDAY THROUGH 03Z
TUESDAY. OTHERWISE...VERY FEW CHANGES TO WINDS/SEAS IN THIS
UPDATE.

...AFTERNOON DISCUSSION...LO PRES REMAINS LOCKED IN PLACE OVR THE
NE STATES TNGT AS LO PRES DEVELOPS OFF THE SE CST. THE LO WILL
TRACK UP THE CAROLINA CST ON MON. DESPITE SOME WAA...WITH NE FLOW
AND A TIGHTENING PRES GRADIENT...THINK WINDS WILL MAKE IT INTO THE
15-20 KT RANGE FOR BOTH THE SRN BAY AND SOUND. THEREFORE DECIDED
TO HOIST A SCA FOR THESE LOCATIONS. THINK WINDS WILL BE QUITE
CLOSE TO SCA THRESHOLDS OVR THE NRN BAY AND OCEAN AS WELL...BUT
WITH MORE UNCERTAINTY THERE WILL HOLD OFF FOR NOW AND WILL ISSUE
HAZARD NEXT SHIFT IF NEC. SEAS WILL MAINLY BE 3-4 FT...WITH SOME
SEAS UP TO 5 FT PSBL OVR SRN CST WTRS MON EVENG. THE
AFOREMENTIONED LO WEAKENS ON TUE AS A STRONG COLD FRNT APPROACHES
FM THE W AND WINDS SLOWLY BCM SELY. SCA WINDS EXPECTED BY WED OVR
ALL WTRS EXCEPT THE RIVERS. THE FRNT CROSSES THE REGION WED NGT
INTO THU MORNG...WITH SCA CONDS CONTINUING POST FRNTAL INTO THU.
SEAS WILL BLD TO 5-8 FT WED INTO THU BEFORE SUBSIDING THU NGT.
WAVES OVR THE BAY WILL REACH 3-4 FT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM TO NOON EST MONDAY FOR VAZ048-
     049-060-061.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 10 PM EST MONDAY FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY FROM 4 AM TO 4 PM EST MONDAY FOR ANZ633.
     SMALL CRAFT ADVISORY FROM 1 PM TO 10 PM EST MONDAY FOR ANZ658.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...DAP/WRS
MARINE...MAS/WRS






000
FXUS61 KAKQ 212346
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
646 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES OFF THE COAST TONIGHT. LOW PRESSURE MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA
COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS THE AREA
WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH MONDAY/...
LATEST ANALYSIS DEPICTS ~1030 MB SFC HIGH PRESSURE CENTERED OVER
ERN CANADA...RIDGING DOWN INTO THE MID ATLC REGION. A TROUGH OF
LOW PRESSURE IS IN PLACE OFF THE COAST OF GA/SC...AND IS PROGGED
TO SHIFT SLOWLY N/E OVERNIGHT. SKIES HAVE CLEARED OUT OVER THE
LOCAL AREA WITH TEMPERATURES INTO THE 40S TO LOWER 50S.

FOR TONIGHT...MAIN CONCERN WILL BE POTENTIAL FOR WINTRY MIX
(PRIMARILY ZR) OVER FAR WRN PORTIONS OF THE CWA. HAVE ISSUED A
FREEZING RAIN ADVISORY FOR THE 4 CLIMO FAVORED COUNTIES ACRS THE
FAR WRN PORTION OF THE CWA (LOUISA/FLUVANNA/CUMBERLAND/PRINCE
EDWARD). OVERALL PATTERN IS NOT FAVORABLE FOR MUCH IMPACT ANYWHERE
ELSE IN THE CWA (SFC HIGH TOO WEAK/PUSHING TOO FAR EAST). THIS
WILL BE A "MINIMAL IMPACT" ADVISORY FOR THE MOST PART...AS BUFKIT
SOUNDINGS (ESPECIALLY THE GFS) SHOW LIMTED SATURATION THROUGH THE
DENDRITIC GROWTH LAYER THROUGH THE DURATION OF THE EVENT (HEAVIER
PRECIP STAYING EAST WHERE IT WILL BE ALL RAIN). STILL ENOUGH
SUPPORT FOR ZR AS MAIN PTYPE (RATHER THAN SLEET) AND IF THE NAM/EC
SCENARIO VERIFIES...THINK THERE IS A GOOD CHC FOR AT LEAST A FEW
HUNDREDTHS OF AN INCH OF ICE ACCUMULATION. DESPITE SOME TIMING
DIFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS
THE AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN
E OF I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A
NARROW LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE
PIEDMONT. THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF
I95 AND N OF RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS
NEAR FREEZING. QPF LOOKS MINIMAL LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTER
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTERNOON AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45 EAST
TOWARD THE ERN SHORE & SERN CHES BAY... M40S-L50S NE NC.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AN UNSETTLED PERIOD...WITH STRONG SSW FLOW ALOFT AS AN AMPLIFIED
UPPER LEVEL TROUGH SLOWLY TRACKS EAST FROM THE PLAINS STATES MON
NIGHT...THROUGH THE MID ATLC AND SE STATES WED NIGHT. BULK OF LIFT
WILL PUSH OFF TO THE NE OF THE AREA MON NIGHT...BUT LOW LEVELS
REMAIN SATURATED SO WILL MAINTAIN A CHC FOR RAIN WITH AREAS OF
DRIZZLE AND FOG MENTIONED LATER MON NIGHT/TUE. GIVEN AN OVERRUNNING
PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE MON NIGHT THROUGH TUE
NIGHT...HAVE SIDED WITH THE COOLEST OF GUIDANCE FOR HIGH
TEMPERATURES TUE (CLOSEST TO THE ECWMF NUMERICAL GUIDANCE). HIGHS
TUE RANGE FROM THE MID-UPPER 40S ALONG/WEST OF I-95 TO THE MID-
UPPER 50S IN NE NC. SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. GFS/ECMWF IN GOOD AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE
FROM THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS
SOAR INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW
ON WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING
TSTMS ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO
BE MUCH IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL
CAPE) ON WED TO LEAD TO SEVERE WX. THIS WILL NEED TO BE MONITORED
FOR SUBSEQUENT CHANGES. HIGHS WED INTO THE MID-UPPER 60S TO AROUND
70 F (CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS
WED...SHIFTING OFF THE COAST LATER WED EVENING AS THE COLD FRONT
PUSHES THROUGH AND DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO
CHRISTMAS MORNING.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
MAINLY CLEAR SKIES PREVAIL OVER THE AREA EARLY THIS EVENING...WITH
SATELLITE IMAGERY INDICATING AN INCREASE IN HIGH CLOUDS SPREADING
NE INTO THE AREA AT 00Z. CEILINGS IN TO 5KFT TO 10KFT RANGE WILL
OVERSPREAD THE AREA AFTER 03Z. VFR CONDITIONS WILL PREVAIL THROUGH
EARLY MONDAY MORNING. LOW PRESSURE FORMING OFF THE SC COAST ALONG
WITH HIGH PRESSURE WEDGING SOUTH WILL CREATE A SETUP FOR A
COOL/RAINY PERIOD MONDAY MORNING THROUGH MONDAY NIGHT WITH MVFR/IFR
VIS/CIGS EXPECTED. AS THE LOW MOVES NORTH...OVER-RUNNING PRECIP
WILL TRACK S TO N MONDAY MORNING... EVENTUALLY REACHING EVERY AKQ
TAF SITE. MAY BE A VERY BRIEF PERIOD OF IP/FZRA AT KRIC...BUT NOT
CONFIDENT ENOUGH TO INCLUDE IN TAFS. HOWEVER...SOME IP/FZRA
POSSIBLE AT SMALLER AIRPORTS W/NW OF KRIC /E.G. KLKU/KFVX/ MONDAY
MORNING. EXPECT A BRIEF PERIOD OF 15-20 KT WIND GUSTS ALONG THE
COAST AS THE LOW MOVES NORTH AND THE PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY NIGHT THROUGH WEDNESDAY. A COLD FRONT
PASSES THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER
THURSDAY AND FRIDAY. A PERIOD OF GUSTY WINDS EXPECTED WEDNESDAY
AFTERNOON THROUGH MIDDAY THURSDAY AHEAD OF AND BEHIND THE FRONT.

&&

.MARINE...
7 PM UPDATE...HAVE RAISED SCA...MAINLY FOR INCREASING
SEAS...ACROSS THE SRN COASTAL WATERS FROM 18Z MONDAY THROUGH 03Z
TUESDAY. OTHERWISE...VERY FEW CHANGES TO WINDS/SEAS IN THIS
UPDATE.

...AFTERNOON DISCUSSION...LO PRES REMAINS LOCKED IN PLACE OVR THE
NE STATES TNGT AS LO PRES DEVELOPS OFF THE SE CST. THE LO WILL
TRACK UP THE CAROLINA CST ON MON. DESPITE SOME WAA...WITH NE FLOW
AND A TIGHTENING PRES GRADIENT...THINK WINDS WILL MAKE IT INTO THE
15-20 KT RANGE FOR BOTH THE SRN BAY AND SOUND. THEREFORE DECIDED
TO HOIST A SCA FOR THESE LOCATIONS. THINK WINDS WILL BE QUITE
CLOSE TO SCA THRESHOLDS OVR THE NRN BAY AND OCEAN AS WELL...BUT
WITH MORE UNCERTAINTY THERE WILL HOLD OFF FOR NOW AND WILL ISSUE
HAZARD NEXT SHIFT IF NEC. SEAS WILL MAINLY BE 3-4 FT...WITH SOME
SEAS UP TO 5 FT PSBL OVR SRN CST WTRS MON EVENG. THE
AFOREMENTIONED LO WEAKENS ON TUE AS A STRONG COLD FRNT APPROACHES
FM THE W AND WINDS SLOWLY BCM SELY. SCA WINDS EXPECTED BY WED OVR
ALL WTRS EXCEPT THE RIVERS. THE FRNT CROSSES THE REGION WED NGT
INTO THU MORNG...WITH SCA CONDS CONTINUING POST FRNTAL INTO THU.
SEAS WILL BLD TO 5-8 FT WED INTO THU BEFORE SUBSIDING THU NGT.
WAVES OVR THE BAY WILL REACH 3-4 FT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM TO NOON EST MONDAY FOR VAZ048-
     049-060-061.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 10 PM EST MONDAY FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY FROM 4 AM TO 4 PM EST MONDAY FOR ANZ633.
     SMALL CRAFT ADVISORY FROM 1 PM TO 10 PM EST MONDAY FOR ANZ658.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...DAP/WRS
MARINE...MAS/WRS







000
FXUS61 KPBZ 212238
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
538 PM EST SUN DEC 21 2014

.SYNOPSIS...
MIDWESTERN LOW PRESSURE WILL BRING WARMER TEMPERATURES AND RAIN TO
THE UPPER OHIO VALLEY REGION FOR THE FIRST HALF OF THE WEEK. SNOW
SHOWER CHANCES WILL COME WITH PASSAGE OF THAT SYSTEMS COLD FRONT
ON CHRISTMAS.

&&

.NEAR TERM /THROUGH MONDAY/...
WITH 530PM UPDATE...TWEAKED SKY COVERAGE AND HOURLY TEMPERATURE
TRENDS. AS QUICKLY AS LOW CLOUDS ERODE FROM THE SOUTH TO THE
NORTH...ADDITIONAL HIGH CLOUDS ALSO MOVE IN FROM THE SOUTH. ALSO
UPDATED HOURLY TEMPERATURE TRENDS AS PARTIAL CLEARING HAS ALLOWED
A SLIGHTLY QUICKER DROP OFF IN TEMPERATURES. PREVIOUS DISCUSSION
FOLLOWS.

WARM ADVECTION BEGINS IN EARNEST OVERNIGHT...BRINGING H850 TEMPS
ABOVE ZERO FOR THE SOUTHERN CWA BY 12Z MONDAY. SOME LOWER CLOUDS
COULD BE REALIZED PRIOR TO 12Z ALONG EAST-FACING SLOPES IN
GARRETT/TUCKER COUNTIES. GENERALLY LEANED TOWARDS THE WARMER
TEMPERATURE GUIDANCE FOR LOWS.

ON MONDAY...INVERTED TROUGH SETS UP ALONG THE CAROLINA COAST.  WITH
DEPARTING HIGH ACROSS NEW ENGLAND...A COLD AIR DAMMING SCENARIO
LOOKS TO BE SETTING UP FOR THE EAST-FACING RIDGES. FOR MOST
AREAS...IT WILL SIMPLY BE A MOSTLY CLOUDY DAY.  BETTER
MOISTURE SPINS AROUND THE INVERTED TROUGH TOWARDS THE SOUTHEAST
CORNER OF THE CWA BEGINNING LATER MONDAY MORNING. WITH THE
OVERNIGHT WARM ADVECTION ALOFT AND COLD AIR EXPECTED TO BE TRAPPED
IN THE VALLEYS...A TEMPERATURE STRUCTURE IDEAL FOR FREEZING RAIN
WILL BE PRESENT ACROSS GARRETT/PRESTON/TUCKER COUNTIES.
HOWEVER...QPF WILL BE THE LIMITING FACTOR AS MOISTURE AND LIFT ARE
TOO SHALLOW TO SUPPORT PRECIPITATION OF ANY SIGNIFICANCE. CANNOT
JUSTIFY ANYTHING HIGHER THAN CHANCE POPS AT PRESENT. ONLY A COUPLE
HUNDREDTHS OF AN INCH OF LIQUID ARE EXPECTED AT MOST. WILL NOT BE
ISSUING ANY HEADLINES AT THE PRESENT TIME. SPS CAN BE USED IN THE
MORNING IF THE THREAT INCREASES. CONTINUED WARM ADVECTION WEST OF
THE RIDGES WILL PUSH MONDAY HIGH TEMPS AT LEAST SEVERAL DEGREES
ABOVE NORMAL...WHILE TEMPS REMAIN IN THE 30S ALONG THE EASTERN CWA
BORDER.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
UPPER TROUGH WILL AMPLIFY AND SLOWLY PIVOT EASTWARD DURING THIS TIME
FRAME...BECOMING MORE NEGATIVELY TILTED WITH THE HELP OF A
STRENGTHENING UPPER LEVEL JET BY LATE WEDNESDAY. EARLY ON...THERE
STILL REMAINS SOME UNCERTAINTY IN REGARD TO THE AMOUNT OF PRECIP
THAT WE WILL SEE ON TUESDAY...AS WE WILL BE PARKED IN BETWEEN THE
BETTER MOISTURE FROM THE WEAK COASTAL SYSTEM...AND THE DEEPENING
MOISTURE ASSOCIATED WITH THE COLD FRONT TO OUR WEST. IN
ADDITION...S-SE WIND SHOULD HELP PROVIDE SOME DOWNSLOPING AND DRYING
JUST EAST OF THE RIDGES IN PA/WV. WITH THIS IN MIND...OPTED TO STAY
WITH THE CHANCE POPS FOR THE DAY TUESDAY. WILL INCREASE POPS
OVERNIGHT AS THE LOW LEVEL JET STRENGTHS AND HELPS TO PULL MOISTURE
FROM THE GULF NORTHWARD. WITH THE NEARLY NORTHWARD PROGRESSION OF
THE DEVELOPING SURFACE LOW...BOTH THE ECMWF AND GFS SUGGEST THE BULK
OF THE HEAVIEST RAIN WILL STAY JUST WEST OF THE FORECAST AREA...WITH
THE BEST CHANCE FOR MODERATE RAIN TO BE AS THE COLD FRONT CROSSES
WEDNESDAY NIGHT. THIS SHOULD LIMIT ANY FLOOD THREAT FOR THE PERIOD.

STRONG WARM ADVECTION WILL BE ONGOING THROUGH THE ENTIRE TIME
PERIOD. EVEN WITH CLOUD COVER...HIGH TEMPERATURES ON BOTH TUESDAY
AND WEDNESDAY SHOULD BE WELL ABOVE SEASONAL VALUES WITH HIGHS
LIKELY TO REACH THE MID 50`S.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
CDFNT PASSAGE WILL INITIATE SNOW SHOWER CHANCES ON CHRISTMAS...BUT
LACK OF DEPTH TO THE COLD LYR...DRY ADVCTN IN THE MID LVLS ON THE
SRN PERIMETER OF NWD DIGGING UPR LOW...AND RAPIDLY ENSUING WARM
ADVCTN WL ENSURE A LACK OF SNOW COVER FOR CHRISTMAS.

THE RMNDR OF THE LONG TERM PD IS PROGGED TO FEATURE SEASONAL TEMPS
WITH A LATE WEEK COOLING TREND AS MDLS PROG A REAMPLIFYING FLOW
PTN WITH ERN CONUS TROFFG.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
GENL IMPROVEMENT TO VFR FOR ALL TAF SITES CAN BE EXPECTED FOR THE
TAF PD AS SLY FLOW ALOFT INTENSIFIES OVR LINGER SFC HIGH PRES.

OUTLOOK.../MONDAY THROUGH FRIDAY/...
MIDWRN LOW PRES WL SPREAD RAIN AND RESTRICTIONS OVR AREA PORTS ON
TUESDAY AND WEDNESDAY. IMPROVEMENTS ARE EXPECTED TO BE INITIATED
LTR ON THURSDAY WITH DRY SHRTWV RIDGING.

&&

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

&&

$$







000
FXUS61 KPBZ 212238
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
538 PM EST SUN DEC 21 2014

.SYNOPSIS...
MIDWESTERN LOW PRESSURE WILL BRING WARMER TEMPERATURES AND RAIN TO
THE UPPER OHIO VALLEY REGION FOR THE FIRST HALF OF THE WEEK. SNOW
SHOWER CHANCES WILL COME WITH PASSAGE OF THAT SYSTEMS COLD FRONT
ON CHRISTMAS.

&&

.NEAR TERM /THROUGH MONDAY/...
WITH 530PM UPDATE...TWEAKED SKY COVERAGE AND HOURLY TEMPERATURE
TRENDS. AS QUICKLY AS LOW CLOUDS ERODE FROM THE SOUTH TO THE
NORTH...ADDITIONAL HIGH CLOUDS ALSO MOVE IN FROM THE SOUTH. ALSO
UPDATED HOURLY TEMPERATURE TRENDS AS PARTIAL CLEARING HAS ALLOWED
A SLIGHTLY QUICKER DROP OFF IN TEMPERATURES. PREVIOUS DISCUSSION
FOLLOWS.

WARM ADVECTION BEGINS IN EARNEST OVERNIGHT...BRINGING H850 TEMPS
ABOVE ZERO FOR THE SOUTHERN CWA BY 12Z MONDAY. SOME LOWER CLOUDS
COULD BE REALIZED PRIOR TO 12Z ALONG EAST-FACING SLOPES IN
GARRETT/TUCKER COUNTIES. GENERALLY LEANED TOWARDS THE WARMER
TEMPERATURE GUIDANCE FOR LOWS.

ON MONDAY...INVERTED TROUGH SETS UP ALONG THE CAROLINA COAST.  WITH
DEPARTING HIGH ACROSS NEW ENGLAND...A COLD AIR DAMMING SCENARIO
LOOKS TO BE SETTING UP FOR THE EAST-FACING RIDGES. FOR MOST
AREAS...IT WILL SIMPLY BE A MOSTLY CLOUDY DAY.  BETTER
MOISTURE SPINS AROUND THE INVERTED TROUGH TOWARDS THE SOUTHEAST
CORNER OF THE CWA BEGINNING LATER MONDAY MORNING. WITH THE
OVERNIGHT WARM ADVECTION ALOFT AND COLD AIR EXPECTED TO BE TRAPPED
IN THE VALLEYS...A TEMPERATURE STRUCTURE IDEAL FOR FREEZING RAIN
WILL BE PRESENT ACROSS GARRETT/PRESTON/TUCKER COUNTIES.
HOWEVER...QPF WILL BE THE LIMITING FACTOR AS MOISTURE AND LIFT ARE
TOO SHALLOW TO SUPPORT PRECIPITATION OF ANY SIGNIFICANCE. CANNOT
JUSTIFY ANYTHING HIGHER THAN CHANCE POPS AT PRESENT. ONLY A COUPLE
HUNDREDTHS OF AN INCH OF LIQUID ARE EXPECTED AT MOST. WILL NOT BE
ISSUING ANY HEADLINES AT THE PRESENT TIME. SPS CAN BE USED IN THE
MORNING IF THE THREAT INCREASES. CONTINUED WARM ADVECTION WEST OF
THE RIDGES WILL PUSH MONDAY HIGH TEMPS AT LEAST SEVERAL DEGREES
ABOVE NORMAL...WHILE TEMPS REMAIN IN THE 30S ALONG THE EASTERN CWA
BORDER.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
UPPER TROUGH WILL AMPLIFY AND SLOWLY PIVOT EASTWARD DURING THIS TIME
FRAME...BECOMING MORE NEGATIVELY TILTED WITH THE HELP OF A
STRENGTHENING UPPER LEVEL JET BY LATE WEDNESDAY. EARLY ON...THERE
STILL REMAINS SOME UNCERTAINTY IN REGARD TO THE AMOUNT OF PRECIP
THAT WE WILL SEE ON TUESDAY...AS WE WILL BE PARKED IN BETWEEN THE
BETTER MOISTURE FROM THE WEAK COASTAL SYSTEM...AND THE DEEPENING
MOISTURE ASSOCIATED WITH THE COLD FRONT TO OUR WEST. IN
ADDITION...S-SE WIND SHOULD HELP PROVIDE SOME DOWNSLOPING AND DRYING
JUST EAST OF THE RIDGES IN PA/WV. WITH THIS IN MIND...OPTED TO STAY
WITH THE CHANCE POPS FOR THE DAY TUESDAY. WILL INCREASE POPS
OVERNIGHT AS THE LOW LEVEL JET STRENGTHS AND HELPS TO PULL MOISTURE
FROM THE GULF NORTHWARD. WITH THE NEARLY NORTHWARD PROGRESSION OF
THE DEVELOPING SURFACE LOW...BOTH THE ECMWF AND GFS SUGGEST THE BULK
OF THE HEAVIEST RAIN WILL STAY JUST WEST OF THE FORECAST AREA...WITH
THE BEST CHANCE FOR MODERATE RAIN TO BE AS THE COLD FRONT CROSSES
WEDNESDAY NIGHT. THIS SHOULD LIMIT ANY FLOOD THREAT FOR THE PERIOD.

STRONG WARM ADVECTION WILL BE ONGOING THROUGH THE ENTIRE TIME
PERIOD. EVEN WITH CLOUD COVER...HIGH TEMPERATURES ON BOTH TUESDAY
AND WEDNESDAY SHOULD BE WELL ABOVE SEASONAL VALUES WITH HIGHS
LIKELY TO REACH THE MID 50`S.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
CDFNT PASSAGE WILL INITIATE SNOW SHOWER CHANCES ON CHRISTMAS...BUT
LACK OF DEPTH TO THE COLD LYR...DRY ADVCTN IN THE MID LVLS ON THE
SRN PERIMETER OF NWD DIGGING UPR LOW...AND RAPIDLY ENSUING WARM
ADVCTN WL ENSURE A LACK OF SNOW COVER FOR CHRISTMAS.

THE RMNDR OF THE LONG TERM PD IS PROGGED TO FEATURE SEASONAL TEMPS
WITH A LATE WEEK COOLING TREND AS MDLS PROG A REAMPLIFYING FLOW
PTN WITH ERN CONUS TROFFG.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
GENL IMPROVEMENT TO VFR FOR ALL TAF SITES CAN BE EXPECTED FOR THE
TAF PD AS SLY FLOW ALOFT INTENSIFIES OVR LINGER SFC HIGH PRES.

OUTLOOK.../MONDAY THROUGH FRIDAY/...
MIDWRN LOW PRES WL SPREAD RAIN AND RESTRICTIONS OVR AREA PORTS ON
TUESDAY AND WEDNESDAY. IMPROVEMENTS ARE EXPECTED TO BE INITIATED
LTR ON THURSDAY WITH DRY SHRTWV RIDGING.

&&

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

&&

$$






000
FXUS61 KAKQ 212124
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
424 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES OFF THE COAST TONIGHT. LOW PRESSURE MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA
COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS THE AREA
WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH MONDAY/...
LATEST ANALYSIS DEPICTS ~1030 MB SFC HIGH PRESSURE CENTERED OVER
ERN CANADA...RIDGING DOWN INTO THE MID ATLC REGION. A TROUGH OF
LOW PRESSURE IS IN PLACE OFF THE COAST OF GA/SC...AND IS PROGGED
TO SHIFT SLOWLY N/E OVERNIGHT. SKIES HAVE CLEARED OUT OVER THE
LOCAL AREA WITH TEMPERATURES INTO THE 40S TO LOWER 50S.

FOR TONIGHT...MAIN CONCERN WILL BE POTENTIAL FOR WINTRY MIX
(PRIMARILY ZR) OVER FAR WRN PORTIONS OF THE CWA. HAVE ISSUED A
FREEZING RAIN ADVISORY FOR THE 4 CLIMO FAVORED COUNTIES ACRS THE
FAR WRN PORTION OF THE CWA (LOUISA/FLUVANNA/CUMBERLAND/PRINCE
EDWARD). OVERALL PATTERN IS NOT FAVORABLE FOR MUCH IMPACT ANYWHERE
ELSE IN THE CWA (SFC HIGH TOO WEAK/PUSHING TOO FAR EAST). THIS
WILL BE A "MINIMAL IMPACT" ADVISORY FOR THE MOST PART...AS BUFKIT
SOUNDINGS (ESPECIALLY THE GFS) SHOW LIMTED SATURATION THROUGH THE
DENDRITIC GROWTH LAYER THROUGH THE DURATION OF THE EVENT (HEAVIER
PRECIP STAYING EAST WHERE IT WILL BE ALL RAIN). STILL ENOUGH
SUPPORT FOR ZR AS MAIN PTYPE (RATHER THAN SLEET) AND IF THE NAM/EC
SCENARIO VERIFIES...THINK THERE IS A GOOD CHC FOR AT LEAST A FEW
HUNDREDTHS OF AN INCH OF ICE ACCUMULATION. DESPITE SOME TIMING
DIFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS
THE AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN
E OF I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A
NARROW LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE
PIEDMONT. THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF
I95 AND N OF RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS
NEAR FREEZING. QPF LOOKS MINIMAL LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTER
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTERNOON AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45 EAST
TOWARD THE ERN SHORE & SERN CHES BAY... M40S-L50S NE NC.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AN UNSETTLED PERIOD...WITH STRONG SSW FLOW ALOFT AS AN AMPLIFIED
UPPER LEVEL TROUGH SLOWLY TRACKS EAST FROM THE PLAINS STATES MON
NIGHT...THROUGH THE MID ATLC AND SE STATES WED NIGHT. BULK OF LIFT
WILL PUSH OFF TO THE NE OF THE AREA MON NIGHT...BUT LOW LEVELS
REMAIN SATURATED SO WILL MAINTAIN A CHC FOR RAIN WITH AREAS OF
DRIZZLE AND FOG MENTIONED LATER MON NIGHT/TUE. GIVEN AN OVERRUNNING
PATTERN WITH A LOW LEVEL FLOW FROM THE E/NE MON NIGHT THROUGH TUE
NIGHT...HAVE SIDED WITH THE COOLEST OF GUIDANCE FOR HIGH
TEMPERATURES TUE (CLOSEST TO THE ECWMF NUMERICAL GUIDANCE). HIGHS
TUE RANGE FROM THE MID-UPPER 40S ALONG/WEST OF I-95 TO THE MID-
UPPER 50S IN NE NC. SFC WARM FRONT WILL LIFT NORTH ACRS THE REGION
LATER TUE NIGHT AND WILL ALLOW FOR THE AREA TO BE WARM SECTORED ON
WED. GFS/ECMWF IN GOOD AGREEMENT WITH ~990 MB SFC LOW TRACKING NNE
FROM THE TN VALLEY TO THE GREAT LAKES DURING THE DAY WED. DEW PTS
SOAR INTO THE UPPER 50S TO LOWER-MID 60S IN STRONG SOUTHERLY FLOW
ON WED...SO WILL CONTINUE MENTION OF SLIGHT CHC FOR AFTN/EVENING
TSTMS ON WED (CHRISTMAS EVE). AT THIS POINT THERE DOES NOT LOOK TO
BE MUCH IN THE WAY OF CLEARING POTENTIAL (HIGH SHEAR BUT MINIMAL
CAPE) ON WED TO LEAD TO SEVERE WX. THIS WILL NEED TO BE MONITORED
FOR SUBSEQUENT CHANGES. HIGHS WED INTO THE MID-UPPER 60S TO AROUND
70 F (CLOSE TO RECORD HIGHS). CATEGORICAL POPS ALL AREAS
WED...SHIFTING OFF THE COAST LATER WED EVENING AS THE COLD FRONT
PUSHES THROUGH AND DRIER AIR MOVES IN FROM THE WEST OVERNIGHT INTO
CHRISTMAS MORNING.


&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
LONG TERM PERIOD WILL FEATURE GENERALLY DRY CONDS AND SLIGHTLY ABOVE
NORMAL TEMPS. FOR THU...AFOREMENTIONED STRONG COLD FRNT AND
MID-LEVEL VORT MAX PUSH OFFSHORE AS SFC HI PRES BLDS OVR THE SE
STATES. EXPECT DECREASING CLOUDS THRU THE DAY WITH A BREEZY W WIND
AND HI TEMPS IN THE LO TO MID 50S. THE HI SLIDES OFFSHORE INTO
FRI...WITH S/SW FLOW DEVELOPING OVR THE MID ATLANTIC AND TEMPS
CLIMBING INTO THE LO TO MID 50S. ANOTHER COLD FRNT WILL CROSS THE
REGION FRI NGT/SAT. LO PRES MAY DEVELOP ALONG THE FRNT OVR THE
WEEKEND...BUT WITH CONSIDERABLE MODEL SPREAD CONCERNING THIS WILL
MAINTAIN SILENT POPS FOR NOW. HI TEMPS SAT STILL IN THE LO TO MID
50S.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH EARLY MONDAY MORNING. LOW
PRESSURE FORMING OFF THE SC COAST ALONG WITH HIGH PRESSURE WEDGING
SOUTH WILL CREATE A SETUP FOR A COOL/RAINY PERIOD MON MORNING
THROUGH MON NIGHT WITH MVFR/IFR VIS/CIGS EXPECTED. AS THE LOW
MOVES NORTH...OVER-RUNNING PRECIP WILL TRACK S TO N MON MORNING...
EVENTUALLY REACHING EVERY AKQ TAF SITE. EXPECT A BRIEF PERIOD OF
15-20 KT WIND GUSTS ALONG THE COAST AS THE LOW MOVES NORTH AND THE
PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
LO PRES REMAINS LOCKED IN PLACE OVR THE NE STATES TNGT AS LO PRES
DEVELOPS OFF THE SE CST. THE LO WILL TRACK UP THE CAROLINA CST ON
MON. DESPITE SOME WAA...WITH NE FLOW AND A TIGHTENING PRES
GRADIENT...THINK WINDS WILL MAKE IT INTO THE 15-20 KT RANGE FOR BOTH
THE SRN BAY AND SOUND. THEREFORE DECIDED TO HOIST A SCA FOR THESE
LOCATIONS. THINK WINDS WILL BE QUITE CLOSE TO SCA THRESHOLDS OVR THE
NRN BAY AND OCEAN AS WELL...BUT WITH MORE UNCERTAINTY THERE WILL
HOLD OFF FOR NOW AND WILL ISSUE HAZARD NEXT SHIFT IF NEC. SEAS WILL
MAINLY BE 3-4 FT...WITH SOME SEAS UP TO 5 FT PSBL OVR SRN CST WTRS
MON EVENG. THE AFOREMENTIONED LO WEAKENS ON TUE AS A STRONG COLD
FRNT APPROACHES FM THE W AND WINDS SLOWLY BCM SELY. SCA WINDS
EXPECTED BY WED OVR ALL WTRS EXCEPT THE RIVERS. THE FRNT CROSSES THE
REGION WED NGT INTO THU MORNG...WITH SCA CONDS CONTINUING POST
FRNTAL INTO THU. SEAS WILL BLD TO 5-8 FT WED INTO THU BEFORE
SUBSIDING THU NGT. WAVES OVR THE BAY WILL REACH 3-4 FT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM TO NOON EST MONDAY FOR VAZ048-
     049-060-061.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 10 PM EST MONDAY FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY FROM 4 AM TO 4 PM EST MONDAY FOR ANZ633.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...DAP
MARINE...MAS






000
FXUS61 KAKQ 212100
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
400 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES OFF THE COAST TONIGHT. LOW PRESSURE MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA
COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS THE AREA
WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST ANALYSIS DEPICTS ~1030 MB SFC HIGH PRESSURE CENTERED OVER
ERN CANADA...RIDGING DOWN INTO THE MID ATLC REGION. A TROUGH OF
LOW PRESSURE IS IN PLACE OFF THE COAST OF GA/SC...AND IS PROGGED
TO SHIFT SLOWLY N/E OVERNIGHT. SKIES HAVE CLEARED OUT OVER THE
LOCAL AREA WITH TEMPERATURES INTO THE 40S TO LOWER 50S.

FOR TONIGHT...MAIN CONCERN WILL BE POTENTIAL FOR WINTRY MIX
(PRIMARILY ZR) OVER FAR WRN PORTIONS OF THE CWA. HAVE ISSUED A
FREEZING RAIN ADVISORY FOR THE 4 CLIMO FAVORED COUNTIES ACRS THE
FAR WRN PORTION OF THE CWA (LOUISA/FLUVANNA/CUMBERLAND/PRINCE
EDWARD). OVERALL PATTERN IS NOT FAVORABLE FOR MUCH IMPACT ANYWHERE
ELSE IN THE CWA (SFC HIGH TOO WEAK/PUSHING TOO FAR EAST). THIS
WILL BE A "MINIMAL IMPACT" ADVISORY FOR THE MOST PART...AS BUFKIT
SOUNDINGS (ESPECIALLY THE GFS) SHOW LIMTED SATURATION THROUGH THE
DENDRITIC GROWTH LAYER THROUGH THE DURATION OF THE EVENT (HEAVIER
PRECIP STAYING EAST WHERE IT WILL BE ALL RAIN). STILL ENOUGH
SUPPORT FOR ZR AS MAIN PTYPE (RATHER THAN SLEET) AND IF THE NAM/EC
SCENARIO VERIFIES...THINK THERE IS A GOOD CHC FOR AT LEAST A FEW
HUNDREDTHS OF AN INCH OF ICE ACCUMULATION. DESPITE SOME TIMING
DIFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS
THE AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN
E OF I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A
NARROW LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE
PIEDMONT. THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF
I95 AND N OF RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS
NEAR FREEZING. QPF LOOKS MINIMAL LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTR
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTRN AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45 EAST
TOWARD THE ERN SHORE & SERN CHES BAY... M40S-L50S NE NC.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...

LOW PRESSURE PROGGED TO LIFT NE ALONG THE CAROLINA COAST MONDAY NIGHT
WITH STDYST PCPN ENDING SW-NE BY 06Z. SNDGS INDCTG ENUF MSTR FOR LGT
RAIN / DRIZZLE THRU THE OVRNITE HRS. TMPS STDY IN THE M30S NW TO M40S
SE. QPF 1/4 TO 1/2 IN.

MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION TUESDAY. HOWEVER...
MOIST EASTERLY FLOW WILL PREVAIL. KEPT LOW CHC (30%) POPS THRU THE
DAY ALTHOUGH SOME DRIZZLE MAY LINGER THROUGH THE MORNING HRS. BIG
TMP DIFFERENCES SEEN IN MOS DATA WHERE NAM IS SOME 5-10 DEGREES
COLDER THAN THE GFS. GIVEN MODELS MAINTAIN AN ERLY SFC FLOW...WILL
SPLIT THE DIFFERENCE FOR NOW AND GO WITH HIGHS FROM THE M-U40S OVR
THE PIEDMONT TO M-U50S CSTL AREAS.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH EARLY MONDAY MORNING. LOW
PRESSURE FORMING OFF THE SC COAST ALONG WITH HIGH PRESSURE WEDGING
SOUTH WILL CREATE A SETUP FOR A COOL/RAINY PERIOD MON MORNING
THROUGH MON NIGHT WITH MVFR/IFR VIS/CIGS EXPECTED. AS THE LOW
MOVES NORTH...OVER-RUNNING PRECIP WILL TRACK S TO N MON MORNING...
EVENTUALLY REACHING EVERY AKQ TAF SITE. EXPECT A BRIEF PERIOD OF
15-20 KT WIND GUSTS ALONG THE COAST AS THE LOW MOVES NORTH AND THE
PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
N-NE WINDS AOB 10 KT WILL PREVAIL TODAY WITH HIGH PRESSURE IN PLACE.
WINDS TURN MORE EASTERLY TONIGHT AND INCREASE TO 10-15 KT MOST AREAS
AS LOW PRESSURE ORGANIZING OFF THE SOUTHEAST COAST SLOWLY PUSHES
NORTH. THE SFC LOW CONTINUES TO MOVE NORTHEAST OF THE NC COAST ON
MONDAY...BUT WEAKENS BY LATE MONDAY/MONDAY NIGHT. WINDS WILL GENERALLY
REMAIN E-NE AOB 15 KT ALL WATERS DURING THIS TIME...BUT TENDING TO
BECOME MORE NORTHERLY AOB 10 KT BY EARLY TUES MORNING. LATEST
GUIDANCE INDICATES POTENTIAL FOR SEAS TO BUILD TO AROUND 5 FT OUT 20
NM LATE MON/MON EVE ACROSS THE SOUTHERN COASTAL WATERS. CONFIDENCE
NOT HIGH ENOUGH TO ISSUE A 3RD PERIOD SCA ATTM.

LIGHT NW WINDS EXPECTED TUES AS HIGH PRESSURE REMAINS IN PLACE OVER
THE MID-ATLANTIC...AND THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE DEEP SOUTH. WINDS TURN E-SE TUESDAY NIGHT AND GRADUALLY BEGIN TO
INCREASE AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. A STRONG
COLD FRONT APPROACHES THE WATERS FROM THE WEST ON WEDNESDAY WITH
WINDS BECOMING SOUTHERLY AND INCREASING TO SCA THRESHOLDS (SAVE THE
RIVERS). THE FRONT QUICKLY SWEEPS THROUGH THE AREA WED NIGHT AND
OFFSHORE EARLY THURSDAY. WINDS REMAIN ABOVE SCA LEVELS THRU LATE
THURSDAY WHILE BECOMING SW THEN W. HIGH PRESSURE RETURNS THU NIGHT
INTO THE START OF NEXT WEEKEND FOR IMPROVED CONDITIONS. SEAS WILL
GENERALLY BUILD TO 5-7 FT ON WED BEFORE SUBSIDING AGAIN LATE THU.
WAVES WILL REACH 4 FT ON THE CHES BAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM TO NOON EST MONDAY FOR VAZ048-
     049-060-061.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 10 PM EST MONDAY FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY FROM 4 AM TO 4 PM EST MONDAY FOR ANZ633.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...DAP
MARINE...MAS






000
FXUS61 KAKQ 212100
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
400 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES OFF THE COAST TONIGHT. LOW PRESSURE MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA
COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS THE AREA
WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST ANALYSIS DEPICTS ~1030 MB SFC HIGH PRESSURE CENTERED OVER
ERN CANADA...RIDGING DOWN INTO THE MID ATLC REGION. A TROUGH OF
LOW PRESSURE IS IN PLACE OFF THE COAST OF GA/SC...AND IS PROGGED
TO SHIFT SLOWLY N/E OVERNIGHT. SKIES HAVE CLEARED OUT OVER THE
LOCAL AREA WITH TEMPERATURES INTO THE 40S TO LOWER 50S.

FOR TONIGHT...MAIN CONCERN WILL BE POTENTIAL FOR WINTRY MIX
(PRIMARILY ZR) OVER FAR WRN PORTIONS OF THE CWA. HAVE ISSUED A
FREEZING RAIN ADVISORY FOR THE 4 CLIMO FAVORED COUNTIES ACRS THE
FAR WRN PORTION OF THE CWA (LOUISA/FLUVANNA/CUMBERLAND/PRINCE
EDWARD). OVERALL PATTERN IS NOT FAVORABLE FOR MUCH IMPACT ANYWHERE
ELSE IN THE CWA (SFC HIGH TOO WEAK/PUSHING TOO FAR EAST). THIS
WILL BE A "MINIMAL IMPACT" ADVISORY FOR THE MOST PART...AS BUFKIT
SOUNDINGS (ESPECIALLY THE GFS) SHOW LIMTED SATURATION THROUGH THE
DENDRITIC GROWTH LAYER THROUGH THE DURATION OF THE EVENT (HEAVIER
PRECIP STAYING EAST WHERE IT WILL BE ALL RAIN). STILL ENOUGH
SUPPORT FOR ZR AS MAIN PTYPE (RATHER THAN SLEET) AND IF THE NAM/EC
SCENARIO VERIFIES...THINK THERE IS A GOOD CHC FOR AT LEAST A FEW
HUNDREDTHS OF AN INCH OF ICE ACCUMULATION. DESPITE SOME TIMING
DIFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS
THE AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN
E OF I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A
NARROW LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE
PIEDMONT. THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF
I95 AND N OF RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS
NEAR FREEZING. QPF LOOKS MINIMAL LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN LATE MON MORNING AS HIGH PRES MOVES INTO
ERN CANADA. THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32
DEGREES THRU 15Z OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA.
EXPECT A QUICK TRANSITION OVER TO ALL RAIN MOST AREAS JUST AFTR
12Z EXCEPT FOR AREAS IN THE ADVISORY WHERE A PERIOD OF ZR SHUD
CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. AREAS FROM
CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST TO DORCHESTER/WICOMICO
MD MAY START OFF AS A RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO
RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTRN AS THE BULK OF
LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT AND CENTRAL VA...40-45 EAST
TOWARD THE ERN SHORE & SERN CHES BAY... M40S-L50S NE NC.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...

LOW PRESSURE PROGGED TO LIFT NE ALONG THE CAROLINA COAST MONDAY NIGHT
WITH STDYST PCPN ENDING SW-NE BY 06Z. SNDGS INDCTG ENUF MSTR FOR LGT
RAIN / DRIZZLE THRU THE OVRNITE HRS. TMPS STDY IN THE M30S NW TO M40S
SE. QPF 1/4 TO 1/2 IN.

MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION TUESDAY. HOWEVER...
MOIST EASTERLY FLOW WILL PREVAIL. KEPT LOW CHC (30%) POPS THRU THE
DAY ALTHOUGH SOME DRIZZLE MAY LINGER THROUGH THE MORNING HRS. BIG
TMP DIFFERENCES SEEN IN MOS DATA WHERE NAM IS SOME 5-10 DEGREES
COLDER THAN THE GFS. GIVEN MODELS MAINTAIN AN ERLY SFC FLOW...WILL
SPLIT THE DIFFERENCE FOR NOW AND GO WITH HIGHS FROM THE M-U40S OVR
THE PIEDMONT TO M-U50S CSTL AREAS.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH EARLY MONDAY MORNING. LOW
PRESSURE FORMING OFF THE SC COAST ALONG WITH HIGH PRESSURE WEDGING
SOUTH WILL CREATE A SETUP FOR A COOL/RAINY PERIOD MON MORNING
THROUGH MON NIGHT WITH MVFR/IFR VIS/CIGS EXPECTED. AS THE LOW
MOVES NORTH...OVER-RUNNING PRECIP WILL TRACK S TO N MON MORNING...
EVENTUALLY REACHING EVERY AKQ TAF SITE. EXPECT A BRIEF PERIOD OF
15-20 KT WIND GUSTS ALONG THE COAST AS THE LOW MOVES NORTH AND THE
PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
N-NE WINDS AOB 10 KT WILL PREVAIL TODAY WITH HIGH PRESSURE IN PLACE.
WINDS TURN MORE EASTERLY TONIGHT AND INCREASE TO 10-15 KT MOST AREAS
AS LOW PRESSURE ORGANIZING OFF THE SOUTHEAST COAST SLOWLY PUSHES
NORTH. THE SFC LOW CONTINUES TO MOVE NORTHEAST OF THE NC COAST ON
MONDAY...BUT WEAKENS BY LATE MONDAY/MONDAY NIGHT. WINDS WILL GENERALLY
REMAIN E-NE AOB 15 KT ALL WATERS DURING THIS TIME...BUT TENDING TO
BECOME MORE NORTHERLY AOB 10 KT BY EARLY TUES MORNING. LATEST
GUIDANCE INDICATES POTENTIAL FOR SEAS TO BUILD TO AROUND 5 FT OUT 20
NM LATE MON/MON EVE ACROSS THE SOUTHERN COASTAL WATERS. CONFIDENCE
NOT HIGH ENOUGH TO ISSUE A 3RD PERIOD SCA ATTM.

LIGHT NW WINDS EXPECTED TUES AS HIGH PRESSURE REMAINS IN PLACE OVER
THE MID-ATLANTIC...AND THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE DEEP SOUTH. WINDS TURN E-SE TUESDAY NIGHT AND GRADUALLY BEGIN TO
INCREASE AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. A STRONG
COLD FRONT APPROACHES THE WATERS FROM THE WEST ON WEDNESDAY WITH
WINDS BECOMING SOUTHERLY AND INCREASING TO SCA THRESHOLDS (SAVE THE
RIVERS). THE FRONT QUICKLY SWEEPS THROUGH THE AREA WED NIGHT AND
OFFSHORE EARLY THURSDAY. WINDS REMAIN ABOVE SCA LEVELS THRU LATE
THURSDAY WHILE BECOMING SW THEN W. HIGH PRESSURE RETURNS THU NIGHT
INTO THE START OF NEXT WEEKEND FOR IMPROVED CONDITIONS. SEAS WILL
GENERALLY BUILD TO 5-7 FT ON WED BEFORE SUBSIDING AGAIN LATE THU.
WAVES WILL REACH 4 FT ON THE CHES BAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...FREEZING RAIN ADVISORY FROM 5 AM TO NOON EST MONDAY FOR VAZ048-
     049-060-061.
MARINE...SMALL CRAFT ADVISORY FROM 7 AM TO 10 PM EST MONDAY FOR ANZ632-
     634.
     SMALL CRAFT ADVISORY FROM 4 AM TO 4 PM EST MONDAY FOR ANZ633.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...LKB/MPR
LONG TERM...MAS
AVIATION...DAP
MARINE...MAS







000
FXUS61 KPHI 212049
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
349 PM EST SUN DEC 21 2014

.SYNOPSIS...
WEAK HIGH PRESSURE ACROSS THE REGION THIS EVENING WILL REMAIN
THROUGH MONDAY. WEAK LOW PRESSURE WILL MOVE NORTHWARD UP ALONG THE
EAST COAST MONDAY AFTERNOON THROUGH TUESDAY NIGHT. THIS LOW WILL BE
FOLLOWED BY ANOTHER STRONGER SYSTEM FOR WEDNESDAY AND WEDNESDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE END OF THE WEEK. A COLD
FRONT WILL CROSS THE AREA NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE CENTER OF A 1030 MB SURFACE HIGH OVER EASTERN CANADA WILL
CONTINUE TO RIDGE SOUTHWARD DOWN THE EASTERN SEABOARD THROUGH
TONIGHT. A MID- TO UPPER-LEVEL RIDGE AXIS WILL PROGRESS TOWARD THE
EAST COAST THIS EVENING.

SOME HI CLOUDS WILL SPILL INTO THE AREA OVERNIGHT AS THE RIDGE
SHIFTS DOWNSTREAM OF OUR AREA AND IS QUICKLY REPLACED BY A LEADING
SHORTWAVE TROUGH THAT IS EXPECTED TO MOVE IN FROM THE SOUTHWEST.

THE SOUTH TO NORTH LOW-LEVEL THERMAL GRADIENT ASSOCIATED WITH A WARM
FRONT IS FORECAST TO STRENGTHEN AS IT MOVES TOWARD SOUTHEAST VA LATE
TONIGHT. ISENTROPIC LIFT WILL DEVELOP ACROSS THE BOUNDARY AND EXPAND
NORTHWARD INTO THE DELMARVA BEFORE DAYBREAK. THE AIRMASS ON COLD
SIDE OF THIS BAROCLINIC ZONE WILL BE INITIALLY DRY SO EXPECT THE
THICKER LOW CLOUDS AND PRECIP TO REMAIN SOUTH OF DELAWARE AND THE
EASTERN SHORE OF MD TONIGHT.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
SOUTHERLY FLOW ALOFT AROUND THE BACKSIDE OF A WESTERN ATLANTIC RIDGE
AND AHEAD OF A TROUGH OVER THE NORTHERN PLAINS WILL BECOME
ESTABLISHED OVER THE EASTERN CONUS ON MONDAY. WAA DEVELOPS OVER THE
FORECAST AREA IN THIS PATTERN, ESPECIALLY IN THE LOW AND MID LEVELS.
AT THE SURFACE, HIGH PRESSURE IS FORECAST TO CONTINUE NOSING
SOUTHWARD DOWN THE EASTERN SIDE OF THE APPALACHIANS EVEN WITH THE
CENTER OF THE AFOREMENTIONED HIGH RETREATING TOWARD THE CANADIAN
MARITIMES. A CAD SETUP WILL KEEP THE COLDER AIR ANCHORED OVER OUR
REGION WITH A NORTHEASTERLY WIND NEAR THE SURFACE. THIS SHOULD
SUPPRESS THE ADVANCEMENT OF THE SURFACE WARM FRONT AS IT APPROACHES
FROM THE SOUTH ON MONDAY.

THE LATEST 12Z NAM CONTINUES TO BE QUICKER AND FARTHER NORTH WITH
THE DEVELOPMENT OF OVERRUNNING PRECIP COMPARED TO THE OTHER
OPERATIONAL MODELS. THE AIRMASS WILL BE VERY DRY INITIALLY, SO
PRECIP MAY NOT REACH THE GROUND AS QUICKLY AS THE NAM INDICATES.
HOWEVER, THERE APPEARS TO BE ENOUGH MOISTURE RETURN AND ISENTROPIC
LIFT FOR PRECIP TO EVENTUALLY OVERCOME THIS INITIAL DRY AIR,
ALLOWING THE PRECIP SHIELD TO EXPAND NORTHWARD THROUGH THE DAY.
CHANCE POPS FIRST ADVERTISED IN THE MORNING FOR THE DELMARVA, MIDDAY
FOR THE SOUTHERN PHILLY SUBURBS AND LATE AFTERNOON FOR THE I-80
CORRIDOR.

PTYPE WILL PREDOMINATELY BE RAIN ON MONDAY, BUT THERE COULD BE A
LIGHT WINTRY MIX (SNOW/SLEET) AWAY FROM THE COAST AT THE ONSET DUE
TO EVAPORATIONAL COOLING. THERE IS STILL NOT ENOUGH FORECAST
CERTAINTY TO PUBLISH A SNOWFALL MAP, BUT THE SETUP APPEARS LIMITED
FOR ANY ACCUMULATIONS EVEN IN THE HIGHER ELEVATIONS OF PA. WE
PREFERRED TO USE THE COOLER NAM/ECMWF FOR THERMAL PROFILES IN THIS
CAD SETUP TO DIAGNOSE POTENTIAL PTYPES AND FOR FORECASTING TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
UNSETTLED WEATHER WILL BE ACROSS THE REGION AT THE BEGINNING OF THE
LONG TERM. A H5 TROUGH WILL BE DEEPENING ACROSS THE MIDDLE PART OF
THE COUNTRY...AND ITS EFFECTS WILL BE FOR CLOUDS AND MOSTLY RAIN
BEGINNING MONDAY NIGHT AND PERSISTING INTO WEDNESDAY NIGHT AND
THURSDAY MORNING. THE FIRST BATCH OF RAIN WILL COME AS WEAK LOW
PRESSURE DEVELOPS ALONG THE CAROLINA COAST MONDAY AND MOVES
NORTHWARD ALONG THE NJ/DE COAST TUESDAY. WE HAVE CHC POPS N/W AND
LIKELY POPS S/E WITH THIS FEATURE. ON TUESDAY...THE HIGHER POPS MOVE
TO THE NORTHERN AREAS AS ONSHORE FLOW AND RESIDUAL MOISTURE FROM THE
LOW REMAIN ACROSS THE AREA.

THERE WILL NOT BE MUCH OF A BREAK IN THE WET PATTERN TUESDAY
NIGHT...ALTHOUGH SOME WEAK RIDGING WILL BE ACROSS THE AREA. ANOTHER
STRONGER LOW PRESSURE SYSTEM WILL BE DEVELOPING ACROSS THE SOUTHERN
STATES AND IT WILL MOVE NORTHWARD TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. THE LOW WILL TRACK TO THE WEST...RESULTING IN A SURGE OF
WARMER AIR ACROSS THE AREA. WE HAVE GONE ALONG WITH THE HIGH POPS
OFFERED BY WPC...WHICH ARE IN THE CATEGORICAL RANGE TUE NIGHT THRU
WED NIGHT.

A STRONG COLD FRONT WILL CROSS THE AREA OVERNIGHT WED NGT INTO THU.
IT APPEARS THAT MOST OF THE SHOWERS WILL BE DONE BY 12Z...BUT WE
HAVE LEFT IN A CHC FOR A FEW SHOWERS THU MORNING...IN CASE THE
SYSTEM SLOWS UP AT ALL. IT APPEARS THAT THE P-TYPE WILL STILL BE
RAIN...SINCE THE COLDER AIR WILL NOT ARRIVE FAST ENOUGH FOR A
CHANGEOVER.

THE REST OF THE EXTENDED PERIOD WILL FEATURE DRIER WEATHER AS A SFC
HIGH EXTENDS ACROSS THE AREA. THE H5 TROUGH WILL STILL BE TO THE
WEST...SO TEMPERATURES WILL REMAIN ABOVE NORMAL BOTH FRI AND SAT.
ANOTHER LOW AND DEVELOPING FRONT MAY BEGIN TO AFFECT THE AREA SAT
NIGHT INTO NEXT SUNDAY...LOW CHC POPS ARE IN THE GRIDS FOR THIS.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

LEFTOVER OVC STRATOCU CONTINUES TO ERODE LATE THIS AFTN OVER MOST OF
THE TERMINALS. AT 20Z, TTN AND RDG LIE ON THE EDGE OF THESE CLOUDS,
WHICH ARE YIELDING MVFR CIGS BETWEEN 2500 AND 3000 FT. EXPECT THE
CLOUDS TO CLEAR OUT AT THESE TWO TERMINALS BY SUNSET AT THE LATEST.

VFR THIS EVE. VFR ANTICIPATED FOR MOST TERMINALS OVERNIGHT AND
MONDAY MORNING THOUGH THE 12Z NAM DEVELOPS STRATUS FROM PHL NORTH
AND EAST, RESULTING IN MVFR AND EVEN IFR CIGS BETWEEN BETWEEN
09-15Z. THIS MAY BE A BIT OVERDONE, BUT WILL STILL NEED TO MONITOR
THE POTENTIAL AS THE MARINE LAYER TRIES TO BECOME ESTABLISHED IN
CONCERT WITH A LIGHT NORTHEAST WIND IN THE BOUNDARY LAYER.
OTHERWISE, MID CLOUDS WILL QUICKLY OVERSPREAD THE AREA FROM
SOUTHWEST TO NORTHEAST IN THE MORNING. RAIN IS ALSO FORECAST TO
DEVELOP IN VICINITY OF ILG/MIV DURING THE MID TO LATE MORNING,
PHL/PNE/RDG DURING THE EARLY TO MID AFTERNOON AND ABE/TTN LATE IN
THE DAY.

OUTLOOK...

MON NIGHT THRU TUE...MOSTLY VFR. INCREASING CLOUDS LATE TUE NIGHT.
TUE NIGHT THRU THU MORNING...OCNL LOW CIGS/VSBYS IN RAIN AND FOG.
THU AFTERNOON THRU FRIDAY...MOSTLY VFR. GUSTY WEST/NORTHWEST WINDS.

&&

.MARINE...
LIGHT NORTHWEST WINDS 5-15 KT THIS AFTERNOON WILL BECOME NORTHERLY
TONIGHT AND NORTHEASTERLY ON MONDAY. SEAS GENERALLY 1-2 FT DURING
THIS TIME.

OUTLOOK...
MON NIGHT...SUB SCA CONDITIONS.
TUE/TUE NGT...SCA CONDITIONS ON THE OCEAN..SUB-SCA OVER DEL BAY.
WED THRU FRI...SCA CONDITIONS WITH LOW END GALE GUSTS WED NGT AND THU.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...O`HARA
NEAR TERM...KLEIN
SHORT TERM...KLEIN
LONG TERM...O`HARA
AVIATION...KLEIN/O`HARA
MARINE...KLEIN/O`HARA






000
FXUS61 KPHI 212049
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
349 PM EST SUN DEC 21 2014

.SYNOPSIS...
WEAK HIGH PRESSURE ACROSS THE REGION THIS EVENING WILL REMAIN
THROUGH MONDAY. WEAK LOW PRESSURE WILL MOVE NORTHWARD UP ALONG THE
EAST COAST MONDAY AFTERNOON THROUGH TUESDAY NIGHT. THIS LOW WILL BE
FOLLOWED BY ANOTHER STRONGER SYSTEM FOR WEDNESDAY AND WEDNESDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FOR THE END OF THE WEEK. A COLD
FRONT WILL CROSS THE AREA NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE CENTER OF A 1030 MB SURFACE HIGH OVER EASTERN CANADA WILL
CONTINUE TO RIDGE SOUTHWARD DOWN THE EASTERN SEABOARD THROUGH
TONIGHT. A MID- TO UPPER-LEVEL RIDGE AXIS WILL PROGRESS TOWARD THE
EAST COAST THIS EVENING.

SOME HI CLOUDS WILL SPILL INTO THE AREA OVERNIGHT AS THE RIDGE
SHIFTS DOWNSTREAM OF OUR AREA AND IS QUICKLY REPLACED BY A LEADING
SHORTWAVE TROUGH THAT IS EXPECTED TO MOVE IN FROM THE SOUTHWEST.

THE SOUTH TO NORTH LOW-LEVEL THERMAL GRADIENT ASSOCIATED WITH A WARM
FRONT IS FORECAST TO STRENGTHEN AS IT MOVES TOWARD SOUTHEAST VA LATE
TONIGHT. ISENTROPIC LIFT WILL DEVELOP ACROSS THE BOUNDARY AND EXPAND
NORTHWARD INTO THE DELMARVA BEFORE DAYBREAK. THE AIRMASS ON COLD
SIDE OF THIS BAROCLINIC ZONE WILL BE INITIALLY DRY SO EXPECT THE
THICKER LOW CLOUDS AND PRECIP TO REMAIN SOUTH OF DELAWARE AND THE
EASTERN SHORE OF MD TONIGHT.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
SOUTHERLY FLOW ALOFT AROUND THE BACKSIDE OF A WESTERN ATLANTIC RIDGE
AND AHEAD OF A TROUGH OVER THE NORTHERN PLAINS WILL BECOME
ESTABLISHED OVER THE EASTERN CONUS ON MONDAY. WAA DEVELOPS OVER THE
FORECAST AREA IN THIS PATTERN, ESPECIALLY IN THE LOW AND MID LEVELS.
AT THE SURFACE, HIGH PRESSURE IS FORECAST TO CONTINUE NOSING
SOUTHWARD DOWN THE EASTERN SIDE OF THE APPALACHIANS EVEN WITH THE
CENTER OF THE AFOREMENTIONED HIGH RETREATING TOWARD THE CANADIAN
MARITIMES. A CAD SETUP WILL KEEP THE COLDER AIR ANCHORED OVER OUR
REGION WITH A NORTHEASTERLY WIND NEAR THE SURFACE. THIS SHOULD
SUPPRESS THE ADVANCEMENT OF THE SURFACE WARM FRONT AS IT APPROACHES
FROM THE SOUTH ON MONDAY.

THE LATEST 12Z NAM CONTINUES TO BE QUICKER AND FARTHER NORTH WITH
THE DEVELOPMENT OF OVERRUNNING PRECIP COMPARED TO THE OTHER
OPERATIONAL MODELS. THE AIRMASS WILL BE VERY DRY INITIALLY, SO
PRECIP MAY NOT REACH THE GROUND AS QUICKLY AS THE NAM INDICATES.
HOWEVER, THERE APPEARS TO BE ENOUGH MOISTURE RETURN AND ISENTROPIC
LIFT FOR PRECIP TO EVENTUALLY OVERCOME THIS INITIAL DRY AIR,
ALLOWING THE PRECIP SHIELD TO EXPAND NORTHWARD THROUGH THE DAY.
CHANCE POPS FIRST ADVERTISED IN THE MORNING FOR THE DELMARVA, MIDDAY
FOR THE SOUTHERN PHILLY SUBURBS AND LATE AFTERNOON FOR THE I-80
CORRIDOR.

PTYPE WILL PREDOMINATELY BE RAIN ON MONDAY, BUT THERE COULD BE A
LIGHT WINTRY MIX (SNOW/SLEET) AWAY FROM THE COAST AT THE ONSET DUE
TO EVAPORATIONAL COOLING. THERE IS STILL NOT ENOUGH FORECAST
CERTAINTY TO PUBLISH A SNOWFALL MAP, BUT THE SETUP APPEARS LIMITED
FOR ANY ACCUMULATIONS EVEN IN THE HIGHER ELEVATIONS OF PA. WE
PREFERRED TO USE THE COOLER NAM/ECMWF FOR THERMAL PROFILES IN THIS
CAD SETUP TO DIAGNOSE POTENTIAL PTYPES AND FOR FORECASTING TEMPS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
UNSETTLED WEATHER WILL BE ACROSS THE REGION AT THE BEGINNING OF THE
LONG TERM. A H5 TROUGH WILL BE DEEPENING ACROSS THE MIDDLE PART OF
THE COUNTRY...AND ITS EFFECTS WILL BE FOR CLOUDS AND MOSTLY RAIN
BEGINNING MONDAY NIGHT AND PERSISTING INTO WEDNESDAY NIGHT AND
THURSDAY MORNING. THE FIRST BATCH OF RAIN WILL COME AS WEAK LOW
PRESSURE DEVELOPS ALONG THE CAROLINA COAST MONDAY AND MOVES
NORTHWARD ALONG THE NJ/DE COAST TUESDAY. WE HAVE CHC POPS N/W AND
LIKELY POPS S/E WITH THIS FEATURE. ON TUESDAY...THE HIGHER POPS MOVE
TO THE NORTHERN AREAS AS ONSHORE FLOW AND RESIDUAL MOISTURE FROM THE
LOW REMAIN ACROSS THE AREA.

THERE WILL NOT BE MUCH OF A BREAK IN THE WET PATTERN TUESDAY
NIGHT...ALTHOUGH SOME WEAK RIDGING WILL BE ACROSS THE AREA. ANOTHER
STRONGER LOW PRESSURE SYSTEM WILL BE DEVELOPING ACROSS THE SOUTHERN
STATES AND IT WILL MOVE NORTHWARD TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. THE LOW WILL TRACK TO THE WEST...RESULTING IN A SURGE OF
WARMER AIR ACROSS THE AREA. WE HAVE GONE ALONG WITH THE HIGH POPS
OFFERED BY WPC...WHICH ARE IN THE CATEGORICAL RANGE TUE NIGHT THRU
WED NIGHT.

A STRONG COLD FRONT WILL CROSS THE AREA OVERNIGHT WED NGT INTO THU.
IT APPEARS THAT MOST OF THE SHOWERS WILL BE DONE BY 12Z...BUT WE
HAVE LEFT IN A CHC FOR A FEW SHOWERS THU MORNING...IN CASE THE
SYSTEM SLOWS UP AT ALL. IT APPEARS THAT THE P-TYPE WILL STILL BE
RAIN...SINCE THE COLDER AIR WILL NOT ARRIVE FAST ENOUGH FOR A
CHANGEOVER.

THE REST OF THE EXTENDED PERIOD WILL FEATURE DRIER WEATHER AS A SFC
HIGH EXTENDS ACROSS THE AREA. THE H5 TROUGH WILL STILL BE TO THE
WEST...SO TEMPERATURES WILL REMAIN ABOVE NORMAL BOTH FRI AND SAT.
ANOTHER LOW AND DEVELOPING FRONT MAY BEGIN TO AFFECT THE AREA SAT
NIGHT INTO NEXT SUNDAY...LOW CHC POPS ARE IN THE GRIDS FOR THIS.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

LEFTOVER OVC STRATOCU CONTINUES TO ERODE LATE THIS AFTN OVER MOST OF
THE TERMINALS. AT 20Z, TTN AND RDG LIE ON THE EDGE OF THESE CLOUDS,
WHICH ARE YIELDING MVFR CIGS BETWEEN 2500 AND 3000 FT. EXPECT THE
CLOUDS TO CLEAR OUT AT THESE TWO TERMINALS BY SUNSET AT THE LATEST.

VFR THIS EVE. VFR ANTICIPATED FOR MOST TERMINALS OVERNIGHT AND
MONDAY MORNING THOUGH THE 12Z NAM DEVELOPS STRATUS FROM PHL NORTH
AND EAST, RESULTING IN MVFR AND EVEN IFR CIGS BETWEEN BETWEEN
09-15Z. THIS MAY BE A BIT OVERDONE, BUT WILL STILL NEED TO MONITOR
THE POTENTIAL AS THE MARINE LAYER TRIES TO BECOME ESTABLISHED IN
CONCERT WITH A LIGHT NORTHEAST WIND IN THE BOUNDARY LAYER.
OTHERWISE, MID CLOUDS WILL QUICKLY OVERSPREAD THE AREA FROM
SOUTHWEST TO NORTHEAST IN THE MORNING. RAIN IS ALSO FORECAST TO
DEVELOP IN VICINITY OF ILG/MIV DURING THE MID TO LATE MORNING,
PHL/PNE/RDG DURING THE EARLY TO MID AFTERNOON AND ABE/TTN LATE IN
THE DAY.

OUTLOOK...

MON NIGHT THRU TUE...MOSTLY VFR. INCREASING CLOUDS LATE TUE NIGHT.
TUE NIGHT THRU THU MORNING...OCNL LOW CIGS/VSBYS IN RAIN AND FOG.
THU AFTERNOON THRU FRIDAY...MOSTLY VFR. GUSTY WEST/NORTHWEST WINDS.

&&

.MARINE...
LIGHT NORTHWEST WINDS 5-15 KT THIS AFTERNOON WILL BECOME NORTHERLY
TONIGHT AND NORTHEASTERLY ON MONDAY. SEAS GENERALLY 1-2 FT DURING
THIS TIME.

OUTLOOK...
MON NIGHT...SUB SCA CONDITIONS.
TUE/TUE NGT...SCA CONDITIONS ON THE OCEAN..SUB-SCA OVER DEL BAY.
WED THRU FRI...SCA CONDITIONS WITH LOW END GALE GUSTS WED NGT AND THU.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...O`HARA
NEAR TERM...KLEIN
SHORT TERM...KLEIN
LONG TERM...O`HARA
AVIATION...KLEIN/O`HARA
MARINE...KLEIN/O`HARA





000
FXUS61 KPBZ 212034
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
334 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE DEPARTS ON MONDAY. EXPECT INCREASING PRECIPITATION
CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN AND WIND CHRISTMAS
EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH MONDAY/...
CLOUDS CONTINUE TO SLOWLY ERODE FROM THE SOUTH EVEN WITH SUN ANGLE
AT ITS MINIMUM...AS DRIER AIR WORKS INTO THE CLOUD BEARING LAYER.
THIS WILL CONTINUE INTO THE EVENING...WITH THE FKL/DUJ AREAS BEING
THE LAST TO SEE THE LOW CLOUDS BREAK.

SURFACE HIGH AND H500 RIDGE AXIS PULL AWAY DURING THE EVENING
HOURS.  WARM ADVECTION BEGINS IN EARNEST AS WELL...BRINGING H850
TEMPS ABOVE ZERO FOR THE SOUTHERN CWA BY 12Z MONDAY.  MID/UPPER
CLOUDS WILL BE ON THE INCREASE IN THIS PATTERN.  SOME LOWER CLOUDS
COULD BE REALIZED PRIOR TO 12Z ALONG EAST-FACING SLOPES IN
GARRETT/TUCKER COUNTIES...BUT EXPECT PRECIP TO HOLD OFF UNTIL AFTER
12Z.  GENERALLY LEANED TOWARDS THE WARMER TEMPERATURE GUIDANCE FOR
LOWS.

ON MONDAY...INVERTED TROUGH SETS UP ALONG THE CAROLINA COAST.  WITH
DEPARTING HIGH ACROSS NEW ENGLAND...A COLD AIR DAMMING SCENARIO
LOOKS TO BE SETTING UP FOR THE EAST-FACING RIDGES.  FOR MOST
AREAS...IT WILL SIMPLY BE A MOSTLY CLOUDY DAY.  HOWEVER...BETTER
MOISTURE SPINS AROUND THE INVERTED TROUGH TOWARDS THE SOUTHEAST
CORNER OF THE CWA BEGINNING LATER MONDAY MORNING.  WITH THE
OVERNIGHT WARM ADVECTION ALOFT AND COLD AIR EXPECTED TO BE TRAPPED
IN THE VALLEYS...A TEMPERATURE STRUCTURE IDEAL FOR FREEZING RAIN
WILL BE PRESENT ACROSS GARRETT/PRESTON/TUCKER COUNTIES.
HOWEVER...QPF WILL BE THE LIMITING FACTOR AS MOISTURE AND LIFT ARE
TOO SHALLOW TO SUPPORT PRECIPITATION OF ANY SIGNIFICANCE. CANNOT
JUSTIFY ANYTHING HIGHER THAN CHANCE POPS AT PRESENT.  ONLY A COUPLE
HUNDREDTHS OF AN INCH OF LIQUID ARE EXPECTED AT MOST. WILL NOT BE
ISSUING ANY HEADLINES AT THE PRESENT TIME.  SPS CAN BE USED IN THE
MORNING IF THE THREAT INCREASES.  CONTINUED WARM ADVECTION WEST OF
THE RIDGES WILL PUSH MONDAY HIGH TEMPS AT LEAST SEVERAL DEGREES
ABOVE NORMAL...WHILE TEMPS REMAIN IN THE 30S ALONG THE EASTERN CWA
BORDER.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
UPPER TROUGH WILL AMPLIFY AND SLOWLY PIVOT EASTWARD DURING THIS TIME
FRAME...BECOMING MORE NEGATIVELY TILTED WITH THE HELP OF A
STRENGTHENING UPPER LEVEL JET BY LATE WEDNESDAY. EARLY ON...THERE
STILL REMAINS SOME UNCERTAINTY IN REGARD TO THE AMOUNT OF PRECIP
THAT WE WILL SEE ON TUESDAY...AS WE WILL BE PARKED IN BETWEEN THE
BETTER MOISTURE FROM THE WEAK COASTAL SYSTEM...AND THE DEEPENING
MOISTURE ASSOCIATED WITH THE COLD FRONT TO OUR WEST. IN
ADDITION...S-SE WIND SHOULD HELP PROVIDE SOME DOWNSLOPING AND DRYING
JUST EAST OF THE RIDGES IN PA/WV. WITH THIS IN MIND...OPTED TO STAY
WITH THE CHANCE POPS FOR THE DAY TUESDAY. WILL INCREASE POPS
OVERNIGHT AS THE LOW LEVEL JET STRENGTHS AND HELPS TO PULL MOISTURE
FROM THE GULF NORTHWARD. WITH THE NEARLY NORTHWARD PROGRESSION OF
THE DEVELOPING SURFACE LOW...BOTH THE ECMWF AND GFS SUGGEST THE BULK
OF THE HEAVIEST RAIN WILL STAY JUST WEST OF THE FORECAST AREA...WITH
THE BEST CHANCE FOR MODERATE RAIN TO BE AS THE COLD FRONT CROSSES
WEDNESDAY NIGHT. THIS SHOULD LIMIT ANY FLOOD THREAT FOR THE PERIOD.

STRONG WARM ADVECTION WILL BE ONGOING THROUGH THE ENTIRE TIME
PERIOD. EVEN WITH CLOUD COVER...HIGH TEMPERATURES ON BOTH TUESDAY
AND WEDNESDAY SHOULD BE WELL ABOVE SEASONAL VALUES WITH HIGHS
LIKELY TO REACH THE MID 50`S.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY. FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST. HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE
GROUND AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS INTO THURSDAY AND HIGHEST ANOMALIES RESIDE
ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS WOULD DO SO AS
WELL. NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO THURSDAY
STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40 MPH
ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME. ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER. EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE. NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS. MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
MVFR CLOUD DECK IS SLOWLY ERODING FROM THE SOUTH. EXPECT ALL SITES
TO ACHIEVE VFR BY 00Z...SAVE FOR POSSIBLY FKL/DUJ WHERE THE CLOUDS
WILL HANG ESPECIALLY TOUGH. VFR THROUGH MOST OF THE
NIGHT...ALTHOUGH SOME MVFR CIGS COULD REDEVELOP TOWARDS DAWN ALONG
THE RIDGES IN SE FLOW. HIGH CLOUDS WILL INCREASE AFTER SUNRISE
MONDAY...AND EXPECT A STRATOCU DECK TO FORM UP WITH TIME. ANY CIGS
SHOULD REMAIN LOW VFR THROUGH 18Z. SPOTTY FREEZING RAIN MAY BE
POSSIBLE IN A FEW VALLEYS IN NORTHEAST WV/WESTERN MD.

OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/... NEXT STORM SYSTEM
WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND RESULT IN
WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF LLWS INTO
THURSDAY.

&&

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

&&

$$








000
FXUS61 KPBZ 212034
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
334 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE DEPARTS ON MONDAY. EXPECT INCREASING PRECIPITATION
CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN AND WIND CHRISTMAS
EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH MONDAY/...
CLOUDS CONTINUE TO SLOWLY ERODE FROM THE SOUTH EVEN WITH SUN ANGLE
AT ITS MINIMUM...AS DRIER AIR WORKS INTO THE CLOUD BEARING LAYER.
THIS WILL CONTINUE INTO THE EVENING...WITH THE FKL/DUJ AREAS BEING
THE LAST TO SEE THE LOW CLOUDS BREAK.

SURFACE HIGH AND H500 RIDGE AXIS PULL AWAY DURING THE EVENING
HOURS.  WARM ADVECTION BEGINS IN EARNEST AS WELL...BRINGING H850
TEMPS ABOVE ZERO FOR THE SOUTHERN CWA BY 12Z MONDAY.  MID/UPPER
CLOUDS WILL BE ON THE INCREASE IN THIS PATTERN.  SOME LOWER CLOUDS
COULD BE REALIZED PRIOR TO 12Z ALONG EAST-FACING SLOPES IN
GARRETT/TUCKER COUNTIES...BUT EXPECT PRECIP TO HOLD OFF UNTIL AFTER
12Z.  GENERALLY LEANED TOWARDS THE WARMER TEMPERATURE GUIDANCE FOR
LOWS.

ON MONDAY...INVERTED TROUGH SETS UP ALONG THE CAROLINA COAST.  WITH
DEPARTING HIGH ACROSS NEW ENGLAND...A COLD AIR DAMMING SCENARIO
LOOKS TO BE SETTING UP FOR THE EAST-FACING RIDGES.  FOR MOST
AREAS...IT WILL SIMPLY BE A MOSTLY CLOUDY DAY.  HOWEVER...BETTER
MOISTURE SPINS AROUND THE INVERTED TROUGH TOWARDS THE SOUTHEAST
CORNER OF THE CWA BEGINNING LATER MONDAY MORNING.  WITH THE
OVERNIGHT WARM ADVECTION ALOFT AND COLD AIR EXPECTED TO BE TRAPPED
IN THE VALLEYS...A TEMPERATURE STRUCTURE IDEAL FOR FREEZING RAIN
WILL BE PRESENT ACROSS GARRETT/PRESTON/TUCKER COUNTIES.
HOWEVER...QPF WILL BE THE LIMITING FACTOR AS MOISTURE AND LIFT ARE
TOO SHALLOW TO SUPPORT PRECIPITATION OF ANY SIGNIFICANCE. CANNOT
JUSTIFY ANYTHING HIGHER THAN CHANCE POPS AT PRESENT.  ONLY A COUPLE
HUNDREDTHS OF AN INCH OF LIQUID ARE EXPECTED AT MOST. WILL NOT BE
ISSUING ANY HEADLINES AT THE PRESENT TIME.  SPS CAN BE USED IN THE
MORNING IF THE THREAT INCREASES.  CONTINUED WARM ADVECTION WEST OF
THE RIDGES WILL PUSH MONDAY HIGH TEMPS AT LEAST SEVERAL DEGREES
ABOVE NORMAL...WHILE TEMPS REMAIN IN THE 30S ALONG THE EASTERN CWA
BORDER.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
UPPER TROUGH WILL AMPLIFY AND SLOWLY PIVOT EASTWARD DURING THIS TIME
FRAME...BECOMING MORE NEGATIVELY TILTED WITH THE HELP OF A
STRENGTHENING UPPER LEVEL JET BY LATE WEDNESDAY. EARLY ON...THERE
STILL REMAINS SOME UNCERTAINTY IN REGARD TO THE AMOUNT OF PRECIP
THAT WE WILL SEE ON TUESDAY...AS WE WILL BE PARKED IN BETWEEN THE
BETTER MOISTURE FROM THE WEAK COASTAL SYSTEM...AND THE DEEPENING
MOISTURE ASSOCIATED WITH THE COLD FRONT TO OUR WEST. IN
ADDITION...S-SE WIND SHOULD HELP PROVIDE SOME DOWNSLOPING AND DRYING
JUST EAST OF THE RIDGES IN PA/WV. WITH THIS IN MIND...OPTED TO STAY
WITH THE CHANCE POPS FOR THE DAY TUESDAY. WILL INCREASE POPS
OVERNIGHT AS THE LOW LEVEL JET STRENGTHS AND HELPS TO PULL MOISTURE
FROM THE GULF NORTHWARD. WITH THE NEARLY NORTHWARD PROGRESSION OF
THE DEVELOPING SURFACE LOW...BOTH THE ECMWF AND GFS SUGGEST THE BULK
OF THE HEAVIEST RAIN WILL STAY JUST WEST OF THE FORECAST AREA...WITH
THE BEST CHANCE FOR MODERATE RAIN TO BE AS THE COLD FRONT CROSSES
WEDNESDAY NIGHT. THIS SHOULD LIMIT ANY FLOOD THREAT FOR THE PERIOD.

STRONG WARM ADVECTION WILL BE ONGOING THROUGH THE ENTIRE TIME
PERIOD. EVEN WITH CLOUD COVER...HIGH TEMPERATURES ON BOTH TUESDAY
AND WEDNESDAY SHOULD BE WELL ABOVE SEASONAL VALUES WITH HIGHS
LIKELY TO REACH THE MID 50`S.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY. FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST. HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE
GROUND AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS INTO THURSDAY AND HIGHEST ANOMALIES RESIDE
ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS WOULD DO SO AS
WELL. NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO THURSDAY
STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40 MPH
ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME. ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER. EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE. NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS. MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
MVFR CLOUD DECK IS SLOWLY ERODING FROM THE SOUTH. EXPECT ALL SITES
TO ACHIEVE VFR BY 00Z...SAVE FOR POSSIBLY FKL/DUJ WHERE THE CLOUDS
WILL HANG ESPECIALLY TOUGH. VFR THROUGH MOST OF THE
NIGHT...ALTHOUGH SOME MVFR CIGS COULD REDEVELOP TOWARDS DAWN ALONG
THE RIDGES IN SE FLOW. HIGH CLOUDS WILL INCREASE AFTER SUNRISE
MONDAY...AND EXPECT A STRATOCU DECK TO FORM UP WITH TIME. ANY CIGS
SHOULD REMAIN LOW VFR THROUGH 18Z. SPOTTY FREEZING RAIN MAY BE
POSSIBLE IN A FEW VALLEYS IN NORTHEAST WV/WESTERN MD.

OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/... NEXT STORM SYSTEM
WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND RESULT IN
WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF LLWS INTO
THURSDAY.

&&

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

&&

$$









000
FXUS61 KLWX 211945
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
245 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH TONIGHT. LOW
PRESSURE WILL TRACK UP THE MID-ATLANTIC COAST MONDAY AND TUESDAY.
A STRONG COLD FRONT WILL APPROACH THE AREA WEDNESDAY BEFORE
PASSING THROUGH WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD OVERHEAD
LATE IN THE WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
HIGH PRESSURE REMAINS OVER THE REGION THIS AFTERNOON AND
SUBSIDENCE BEHIND A SHORTWAVE HAS ALLOWED FOR SUNSHINE. HIGH
PRESSURE WILL BECOME CENTERED OVER NEW ENGLAND TONIGHT AND THE
SURFACE RIDGE AXIS WILL DROP SOUTHWEST THROUGH OUR REGION DURING
THIS TIME.

POTENT LOW PRESSURE WILL TRACK THROUGH THE PLAINS TONIGHT THROUGH
MONDAY. A WARM FRONT WILL EXTEND SOUTHEAST FROM THIS SYSTEM
THROUGH THE TENNESSEE VALLEY INTO THE APPALACHIANS WHERE IT WILL
BECOME A STATIONARY FRONT THAT CONTINUES TO EXTEND THROUGH THE
SOUTHEASTERN CONUS. LOW PRESSURE WILL DEVELOP ALONG THIS BOUNDARY
OFF THE SOUTHEAST COAST TONIGHT AND IT IS EXPECTED TO TRACK UP THE
MID-ATLANTIC COAST MONDAY. THIS SYSTEM WILL BE WEAK AND MOST OF
THE DYNAMICS WILL REMAIN WELL TO OUR WEST...CLOSER TO THE STRONGER
LOW OVER THE PLAINS. HOWEVER...WARM AND MOIST AIR FROM THE GULF OF
MEXICO AND ATLANTIC OCEAN WILL OVERRUN THE COLDER AND DRIER AIR
THAT IS CURRENTLY IN PLACE. THIS WILL CAUSE CLOUDS TO INCREASE
OVERNIGHT AND PRECIPITATION IS EXPECTED TO OVERSPREAD AT LEAST
PORTIONS OF THE AREA MONDAY MORNING INTO MONDAY AFTERNOON.

THERE WILL BE ENOUGH COLD AIR FOR POSSIBLE FROZEN PRECIPITATION
MONDAY...ESPECIALLY NORTH AND WEST OF INTERSTATE 95. THE MAIN
IMPACT FROM FROZEN PRECIPITATION WOULD BE FROM FREEZING
RAIN...ALTHOUGH SNOW AND SLEET MAY MIX WITH
PRECIPITATION...ESPECIALLY AT THE ONSET. HOWEVER...THERE IS STILL
SOME UNCERTAINTY AS TO HOW FAR NORTH AND WEST THE PRECIPITATION
WILL MAKE IT SINCE IT WILL BE RUNNING INTO DRIER AIR. THE HIGHEST
CONFIDENCE FOR PRECIPITATION AND SUBFREEZING TEMPERATURES IS
ACROSS CENTRAL VIRGINIA. A FREEZING RAIN ADVISORY IS IN EFFECT FOR
THESE AREAS MONDAY MORNING. FREEZING RAIN MAY CONTINUE INTO THE
AFTERNOON HOURS AS WELL.

FOR THE WASHINGTON AND BALTIMORE METROPOLITAN
AREAS...CONFIDENCE IS NOT YET HIGH ENOUGH FOR A HEADLINE SINCE
TEMPERATURES WILL BE MARGINAL AND IMPACT FROM FROZEN PRECIPITATION
IS NOT EXPECTED TO OCCUR UNTIL LATER MONDAY MORNING OR AFTERNOON.
PRECIPITATION WILL LIKELY OVERSPREAD THESE AREAS DURING THE MID TO
LATE MORNING HOURS MONDAY AND CONTINUE THROUGH MONDAY AFTERNOON.
FROZEN PRECIPITATION IS POSSIBLE...ESPECIALLY NORTH AND WEST OF
INTERSTATE 95. A FREEZING RAIN ADVISORY MAY BE NEEDED FOR PORTIONS
OF THESE AREAS.

FOR THE POTOMAC HIGHLANDS...NORTHERN MARYLAND AND EASTERN WEST
VIRGINIA. TEMPERATURES WILL BE COLD ENOUGH FOR FROZEN
PRECIPITATION...BUT THE NORTHERN AND WESTERN EXTENT OF THE PRECIP
IS TOO UNCERTAIN AT THIS TIME TO ISSUE AN ADVISORY. ANY IMPACT
FROM FROZEN PRECIPITATION WOULD NOT OCCUR UNTIL MONDAY AFTERNOON.

MAX TEMPS MONDAY WILL RANGE FROM THE UPPER 20S AND LOWER 30S
ACROSS THE ALLEGHENY AND POTOMAC HIGHLANDS...TO THE MIDDLE 30S
NEAR WASHINGTON AND BALTIMORE...TO NEAR 40 IN SOUTHERN MARYLAND.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
LIGHT PRECIPITATION WILL CONTINUE MONDAY NIGHT INTO TUESDAY MORNING.
THE BIG QUESTION WILL BE HOW LONG THE CAD WEDGE WILL REMAIN IN
PLACE. THERE IS STILL POTENTIAL FOR TEMPERATURES TO REMAIN AT OR
BELOW FREEZING MAINLY WEST OF THE BLUE RIDGE LEAVING THE POTENTIAL
FOR LIGHT FREEZING RAIN TO CONTINUE. TO THE EAST OF THE BLUE RIDGE
AND ACROSS THE METRO AREAS...WARMER AIR WILL LIKELY WIN OUT KEEPING
PRECIPITATION IN THE FORM OF RAIN. A BRIEF RESPITE FROM THE
PRECIPITATION IS POSSIBLE TUESDAY AFTERNOON/EVENING BEFORE THE NEXT
ROUND OF RAINFALL MOVES IN FROM THE WEST LATER TUESDAY NIGHT.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
STRONG COLD FRONT CROSSING THE MID ATLANTIC REGION WEDNESDAY INTO
THURSDAY. LIQUID PRECIPITATION SHOULD ACCOMPANY THE FRONT EXCEPT
ALONG THE ALLEGHENY  FRONT WHERE ARRIVAL OF COLDER AIR WILL CAUSE THE
RAIN TO CHANGE OVER TO SNOW BEFORE PRECIPITATION ENDS THURSDAY.

PASSAGE OF SHORTWAVE WILL SUPPORT DEVELOPMENT OF A COASTAL LOW LATE
SATURDAY AND SUNDAY. PRECIPITATION MAY START AS A WINTRY MIX AT
HIGHER ELEVATIONS.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS THROUGH THIS EVENING. CLOUDS WILL INCREASE
OVERNIGHT AND PRECIPITATION WILL OVERSPREAD THE TERMINALS MONDAY
FROM SOUTHWEST TO NORTHEAST. FREEZING RAIN IS EXPECTED ACROSS KCHO
AND POSSIBLY KMRB AND KIAD. FREEZING RAIN MAY MIX WITH SLEET AND
SNOW AT THE ONSET. RAIN IS EXPECTED ACROSS THE REST OF THE
TERMINALS. RAIN MAY MIX WITH SLEET AT THE ONSET. CIGS/VSBYS WILL
DETERIORATE TO MVFR LEVELS MONDAY WITH POSSIBLE IFR LEVELS.

SUB VFR CIGS AND VSBYS EXPECTED MONDAY NIGHT INTO TUESDAY. LIGHT
FREEZING RAIN WILL BE POSSIBLE WEST OF THE BLUE RIDGE WITH RAIN TO
THE EAST. A PRECIPITATION RESPITE MAY OCCUR TUESDAY AFTERNOON BEFORE
RAIN MOVES BACK IN LATER TUESDAY NIGHT. A STRONG COLD FRONT WILL
APPROACH THE TERMINALS WEDNESDAY BEFORE PASSING THROUGH
WEDNESDAY NIGHT. MORE RAIN AND SUBVFR CONDITIONS ARE EXPECTED.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS TONIGHT. LOW PRESSURE
WILL TRACK UP THE MID-ATLANTIC COAST MONDAY. A SMALL CRAFT
ADVISORY IS IN EFFECT FOR THE MIDDLE PORTIONS OF THE BAY AND LOWER
TIDAL POTOMAC RIVER.

WINDS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA MONDAY NIGHT THROUGH
TUESDAY NIGHT. A STRONG COLD FRONT WILL APPROACH THE WATERS
WEDNESDAY BEFORE PASSING THROUGH WEDNESDAY NIGHT. A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED FOR THE WATERS WEDNESDAY AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...FREEZING RAIN ADVISORY FROM 6 AM TO NOON EST MONDAY FOR VAZ025-
     026-029-036>040-050-051-501>504-507-508.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM TO 6 PM EST MONDAY FOR ANZ534-
     537-543.

&&

$$
SYNOPSIS...BJL
NEAR TERM...BJL
SHORT TERM...KRW
LONG TERM...CEM
AVIATION...BJL/KRW
MARINE...BJL/KRW







000
FXUS61 KLWX 211945
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
245 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH TONIGHT. LOW
PRESSURE WILL TRACK UP THE MID-ATLANTIC COAST MONDAY AND TUESDAY.
A STRONG COLD FRONT WILL APPROACH THE AREA WEDNESDAY BEFORE
PASSING THROUGH WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD OVERHEAD
LATE IN THE WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
HIGH PRESSURE REMAINS OVER THE REGION THIS AFTERNOON AND
SUBSIDENCE BEHIND A SHORTWAVE HAS ALLOWED FOR SUNSHINE. HIGH
PRESSURE WILL BECOME CENTERED OVER NEW ENGLAND TONIGHT AND THE
SURFACE RIDGE AXIS WILL DROP SOUTHWEST THROUGH OUR REGION DURING
THIS TIME.

POTENT LOW PRESSURE WILL TRACK THROUGH THE PLAINS TONIGHT THROUGH
MONDAY. A WARM FRONT WILL EXTEND SOUTHEAST FROM THIS SYSTEM
THROUGH THE TENNESSEE VALLEY INTO THE APPALACHIANS WHERE IT WILL
BECOME A STATIONARY FRONT THAT CONTINUES TO EXTEND THROUGH THE
SOUTHEASTERN CONUS. LOW PRESSURE WILL DEVELOP ALONG THIS BOUNDARY
OFF THE SOUTHEAST COAST TONIGHT AND IT IS EXPECTED TO TRACK UP THE
MID-ATLANTIC COAST MONDAY. THIS SYSTEM WILL BE WEAK AND MOST OF
THE DYNAMICS WILL REMAIN WELL TO OUR WEST...CLOSER TO THE STRONGER
LOW OVER THE PLAINS. HOWEVER...WARM AND MOIST AIR FROM THE GULF OF
MEXICO AND ATLANTIC OCEAN WILL OVERRUN THE COLDER AND DRIER AIR
THAT IS CURRENTLY IN PLACE. THIS WILL CAUSE CLOUDS TO INCREASE
OVERNIGHT AND PRECIPITATION IS EXPECTED TO OVERSPREAD AT LEAST
PORTIONS OF THE AREA MONDAY MORNING INTO MONDAY AFTERNOON.

THERE WILL BE ENOUGH COLD AIR FOR POSSIBLE FROZEN PRECIPITATION
MONDAY...ESPECIALLY NORTH AND WEST OF INTERSTATE 95. THE MAIN
IMPACT FROM FROZEN PRECIPITATION WOULD BE FROM FREEZING
RAIN...ALTHOUGH SNOW AND SLEET MAY MIX WITH
PRECIPITATION...ESPECIALLY AT THE ONSET. HOWEVER...THERE IS STILL
SOME UNCERTAINTY AS TO HOW FAR NORTH AND WEST THE PRECIPITATION
WILL MAKE IT SINCE IT WILL BE RUNNING INTO DRIER AIR. THE HIGHEST
CONFIDENCE FOR PRECIPITATION AND SUBFREEZING TEMPERATURES IS
ACROSS CENTRAL VIRGINIA. A FREEZING RAIN ADVISORY IS IN EFFECT FOR
THESE AREAS MONDAY MORNING. FREEZING RAIN MAY CONTINUE INTO THE
AFTERNOON HOURS AS WELL.

FOR THE WASHINGTON AND BALTIMORE METROPOLITAN
AREAS...CONFIDENCE IS NOT YET HIGH ENOUGH FOR A HEADLINE SINCE
TEMPERATURES WILL BE MARGINAL AND IMPACT FROM FROZEN PRECIPITATION
IS NOT EXPECTED TO OCCUR UNTIL LATER MONDAY MORNING OR AFTERNOON.
PRECIPITATION WILL LIKELY OVERSPREAD THESE AREAS DURING THE MID TO
LATE MORNING HOURS MONDAY AND CONTINUE THROUGH MONDAY AFTERNOON.
FROZEN PRECIPITATION IS POSSIBLE...ESPECIALLY NORTH AND WEST OF
INTERSTATE 95. A FREEZING RAIN ADVISORY MAY BE NEEDED FOR PORTIONS
OF THESE AREAS.

FOR THE POTOMAC HIGHLANDS...NORTHERN MARYLAND AND EASTERN WEST
VIRGINIA. TEMPERATURES WILL BE COLD ENOUGH FOR FROZEN
PRECIPITATION...BUT THE NORTHERN AND WESTERN EXTENT OF THE PRECIP
IS TOO UNCERTAIN AT THIS TIME TO ISSUE AN ADVISORY. ANY IMPACT
FROM FROZEN PRECIPITATION WOULD NOT OCCUR UNTIL MONDAY AFTERNOON.

MAX TEMPS MONDAY WILL RANGE FROM THE UPPER 20S AND LOWER 30S
ACROSS THE ALLEGHENY AND POTOMAC HIGHLANDS...TO THE MIDDLE 30S
NEAR WASHINGTON AND BALTIMORE...TO NEAR 40 IN SOUTHERN MARYLAND.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
LIGHT PRECIPITATION WILL CONTINUE MONDAY NIGHT INTO TUESDAY MORNING.
THE BIG QUESTION WILL BE HOW LONG THE CAD WEDGE WILL REMAIN IN
PLACE. THERE IS STILL POTENTIAL FOR TEMPERATURES TO REMAIN AT OR
BELOW FREEZING MAINLY WEST OF THE BLUE RIDGE LEAVING THE POTENTIAL
FOR LIGHT FREEZING RAIN TO CONTINUE. TO THE EAST OF THE BLUE RIDGE
AND ACROSS THE METRO AREAS...WARMER AIR WILL LIKELY WIN OUT KEEPING
PRECIPITATION IN THE FORM OF RAIN. A BRIEF RESPITE FROM THE
PRECIPITATION IS POSSIBLE TUESDAY AFTERNOON/EVENING BEFORE THE NEXT
ROUND OF RAINFALL MOVES IN FROM THE WEST LATER TUESDAY NIGHT.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
STRONG COLD FRONT CROSSING THE MID ATLANTIC REGION WEDNESDAY INTO
THURSDAY. LIQUID PRECIPITATION SHOULD ACCOMPANY THE FRONT EXCEPT
ALONG THE ALLEGHENY  FRONT WHERE ARRIVAL OF COLDER AIR WILL CAUSE THE
RAIN TO CHANGE OVER TO SNOW BEFORE PRECIPITATION ENDS THURSDAY.

PASSAGE OF SHORTWAVE WILL SUPPORT DEVELOPMENT OF A COASTAL LOW LATE
SATURDAY AND SUNDAY. PRECIPITATION MAY START AS A WINTRY MIX AT
HIGHER ELEVATIONS.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS THROUGH THIS EVENING. CLOUDS WILL INCREASE
OVERNIGHT AND PRECIPITATION WILL OVERSPREAD THE TERMINALS MONDAY
FROM SOUTHWEST TO NORTHEAST. FREEZING RAIN IS EXPECTED ACROSS KCHO
AND POSSIBLY KMRB AND KIAD. FREEZING RAIN MAY MIX WITH SLEET AND
SNOW AT THE ONSET. RAIN IS EXPECTED ACROSS THE REST OF THE
TERMINALS. RAIN MAY MIX WITH SLEET AT THE ONSET. CIGS/VSBYS WILL
DETERIORATE TO MVFR LEVELS MONDAY WITH POSSIBLE IFR LEVELS.

SUB VFR CIGS AND VSBYS EXPECTED MONDAY NIGHT INTO TUESDAY. LIGHT
FREEZING RAIN WILL BE POSSIBLE WEST OF THE BLUE RIDGE WITH RAIN TO
THE EAST. A PRECIPITATION RESPITE MAY OCCUR TUESDAY AFTERNOON BEFORE
RAIN MOVES BACK IN LATER TUESDAY NIGHT. A STRONG COLD FRONT WILL
APPROACH THE TERMINALS WEDNESDAY BEFORE PASSING THROUGH
WEDNESDAY NIGHT. MORE RAIN AND SUBVFR CONDITIONS ARE EXPECTED.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS TONIGHT. LOW PRESSURE
WILL TRACK UP THE MID-ATLANTIC COAST MONDAY. A SMALL CRAFT
ADVISORY IS IN EFFECT FOR THE MIDDLE PORTIONS OF THE BAY AND LOWER
TIDAL POTOMAC RIVER.

WINDS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA MONDAY NIGHT THROUGH
TUESDAY NIGHT. A STRONG COLD FRONT WILL APPROACH THE WATERS
WEDNESDAY BEFORE PASSING THROUGH WEDNESDAY NIGHT. A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED FOR THE WATERS WEDNESDAY AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...FREEZING RAIN ADVISORY FROM 6 AM TO NOON EST MONDAY FOR VAZ025-
     026-029-036>040-050-051-501>504-507-508.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM TO 6 PM EST MONDAY FOR ANZ534-
     537-543.

&&

$$
SYNOPSIS...BJL
NEAR TERM...BJL
SHORT TERM...KRW
LONG TERM...CEM
AVIATION...BJL/KRW
MARINE...BJL/KRW








000
FXUS61 KLWX 211945
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
245 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH TONIGHT. LOW
PRESSURE WILL TRACK UP THE MID-ATLANTIC COAST MONDAY AND TUESDAY.
A STRONG COLD FRONT WILL APPROACH THE AREA WEDNESDAY BEFORE
PASSING THROUGH WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD OVERHEAD
LATE IN THE WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
HIGH PRESSURE REMAINS OVER THE REGION THIS AFTERNOON AND
SUBSIDENCE BEHIND A SHORTWAVE HAS ALLOWED FOR SUNSHINE. HIGH
PRESSURE WILL BECOME CENTERED OVER NEW ENGLAND TONIGHT AND THE
SURFACE RIDGE AXIS WILL DROP SOUTHWEST THROUGH OUR REGION DURING
THIS TIME.

POTENT LOW PRESSURE WILL TRACK THROUGH THE PLAINS TONIGHT THROUGH
MONDAY. A WARM FRONT WILL EXTEND SOUTHEAST FROM THIS SYSTEM
THROUGH THE TENNESSEE VALLEY INTO THE APPALACHIANS WHERE IT WILL
BECOME A STATIONARY FRONT THAT CONTINUES TO EXTEND THROUGH THE
SOUTHEASTERN CONUS. LOW PRESSURE WILL DEVELOP ALONG THIS BOUNDARY
OFF THE SOUTHEAST COAST TONIGHT AND IT IS EXPECTED TO TRACK UP THE
MID-ATLANTIC COAST MONDAY. THIS SYSTEM WILL BE WEAK AND MOST OF
THE DYNAMICS WILL REMAIN WELL TO OUR WEST...CLOSER TO THE STRONGER
LOW OVER THE PLAINS. HOWEVER...WARM AND MOIST AIR FROM THE GULF OF
MEXICO AND ATLANTIC OCEAN WILL OVERRUN THE COLDER AND DRIER AIR
THAT IS CURRENTLY IN PLACE. THIS WILL CAUSE CLOUDS TO INCREASE
OVERNIGHT AND PRECIPITATION IS EXPECTED TO OVERSPREAD AT LEAST
PORTIONS OF THE AREA MONDAY MORNING INTO MONDAY AFTERNOON.

THERE WILL BE ENOUGH COLD AIR FOR POSSIBLE FROZEN PRECIPITATION
MONDAY...ESPECIALLY NORTH AND WEST OF INTERSTATE 95. THE MAIN
IMPACT FROM FROZEN PRECIPITATION WOULD BE FROM FREEZING
RAIN...ALTHOUGH SNOW AND SLEET MAY MIX WITH
PRECIPITATION...ESPECIALLY AT THE ONSET. HOWEVER...THERE IS STILL
SOME UNCERTAINTY AS TO HOW FAR NORTH AND WEST THE PRECIPITATION
WILL MAKE IT SINCE IT WILL BE RUNNING INTO DRIER AIR. THE HIGHEST
CONFIDENCE FOR PRECIPITATION AND SUBFREEZING TEMPERATURES IS
ACROSS CENTRAL VIRGINIA. A FREEZING RAIN ADVISORY IS IN EFFECT FOR
THESE AREAS MONDAY MORNING. FREEZING RAIN MAY CONTINUE INTO THE
AFTERNOON HOURS AS WELL.

FOR THE WASHINGTON AND BALTIMORE METROPOLITAN
AREAS...CONFIDENCE IS NOT YET HIGH ENOUGH FOR A HEADLINE SINCE
TEMPERATURES WILL BE MARGINAL AND IMPACT FROM FROZEN PRECIPITATION
IS NOT EXPECTED TO OCCUR UNTIL LATER MONDAY MORNING OR AFTERNOON.
PRECIPITATION WILL LIKELY OVERSPREAD THESE AREAS DURING THE MID TO
LATE MORNING HOURS MONDAY AND CONTINUE THROUGH MONDAY AFTERNOON.
FROZEN PRECIPITATION IS POSSIBLE...ESPECIALLY NORTH AND WEST OF
INTERSTATE 95. A FREEZING RAIN ADVISORY MAY BE NEEDED FOR PORTIONS
OF THESE AREAS.

FOR THE POTOMAC HIGHLANDS...NORTHERN MARYLAND AND EASTERN WEST
VIRGINIA. TEMPERATURES WILL BE COLD ENOUGH FOR FROZEN
PRECIPITATION...BUT THE NORTHERN AND WESTERN EXTENT OF THE PRECIP
IS TOO UNCERTAIN AT THIS TIME TO ISSUE AN ADVISORY. ANY IMPACT
FROM FROZEN PRECIPITATION WOULD NOT OCCUR UNTIL MONDAY AFTERNOON.

MAX TEMPS MONDAY WILL RANGE FROM THE UPPER 20S AND LOWER 30S
ACROSS THE ALLEGHENY AND POTOMAC HIGHLANDS...TO THE MIDDLE 30S
NEAR WASHINGTON AND BALTIMORE...TO NEAR 40 IN SOUTHERN MARYLAND.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
LIGHT PRECIPITATION WILL CONTINUE MONDAY NIGHT INTO TUESDAY MORNING.
THE BIG QUESTION WILL BE HOW LONG THE CAD WEDGE WILL REMAIN IN
PLACE. THERE IS STILL POTENTIAL FOR TEMPERATURES TO REMAIN AT OR
BELOW FREEZING MAINLY WEST OF THE BLUE RIDGE LEAVING THE POTENTIAL
FOR LIGHT FREEZING RAIN TO CONTINUE. TO THE EAST OF THE BLUE RIDGE
AND ACROSS THE METRO AREAS...WARMER AIR WILL LIKELY WIN OUT KEEPING
PRECIPITATION IN THE FORM OF RAIN. A BRIEF RESPITE FROM THE
PRECIPITATION IS POSSIBLE TUESDAY AFTERNOON/EVENING BEFORE THE NEXT
ROUND OF RAINFALL MOVES IN FROM THE WEST LATER TUESDAY NIGHT.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
STRONG COLD FRONT CROSSING THE MID ATLANTIC REGION WEDNESDAY INTO
THURSDAY. LIQUID PRECIPITATION SHOULD ACCOMPANY THE FRONT EXCEPT
ALONG THE ALLEGHENY  FRONT WHERE ARRIVAL OF COLDER AIR WILL CAUSE THE
RAIN TO CHANGE OVER TO SNOW BEFORE PRECIPITATION ENDS THURSDAY.

PASSAGE OF SHORTWAVE WILL SUPPORT DEVELOPMENT OF A COASTAL LOW LATE
SATURDAY AND SUNDAY. PRECIPITATION MAY START AS A WINTRY MIX AT
HIGHER ELEVATIONS.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS THROUGH THIS EVENING. CLOUDS WILL INCREASE
OVERNIGHT AND PRECIPITATION WILL OVERSPREAD THE TERMINALS MONDAY
FROM SOUTHWEST TO NORTHEAST. FREEZING RAIN IS EXPECTED ACROSS KCHO
AND POSSIBLY KMRB AND KIAD. FREEZING RAIN MAY MIX WITH SLEET AND
SNOW AT THE ONSET. RAIN IS EXPECTED ACROSS THE REST OF THE
TERMINALS. RAIN MAY MIX WITH SLEET AT THE ONSET. CIGS/VSBYS WILL
DETERIORATE TO MVFR LEVELS MONDAY WITH POSSIBLE IFR LEVELS.

SUB VFR CIGS AND VSBYS EXPECTED MONDAY NIGHT INTO TUESDAY. LIGHT
FREEZING RAIN WILL BE POSSIBLE WEST OF THE BLUE RIDGE WITH RAIN TO
THE EAST. A PRECIPITATION RESPITE MAY OCCUR TUESDAY AFTERNOON BEFORE
RAIN MOVES BACK IN LATER TUESDAY NIGHT. A STRONG COLD FRONT WILL
APPROACH THE TERMINALS WEDNESDAY BEFORE PASSING THROUGH
WEDNESDAY NIGHT. MORE RAIN AND SUBVFR CONDITIONS ARE EXPECTED.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS TONIGHT. LOW PRESSURE
WILL TRACK UP THE MID-ATLANTIC COAST MONDAY. A SMALL CRAFT
ADVISORY IS IN EFFECT FOR THE MIDDLE PORTIONS OF THE BAY AND LOWER
TIDAL POTOMAC RIVER.

WINDS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA MONDAY NIGHT THROUGH
TUESDAY NIGHT. A STRONG COLD FRONT WILL APPROACH THE WATERS
WEDNESDAY BEFORE PASSING THROUGH WEDNESDAY NIGHT. A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED FOR THE WATERS WEDNESDAY AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...FREEZING RAIN ADVISORY FROM 6 AM TO NOON EST MONDAY FOR VAZ025-
     026-029-036>040-050-051-501>504-507-508.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM TO 6 PM EST MONDAY FOR ANZ534-
     537-543.

&&

$$
SYNOPSIS...BJL
NEAR TERM...BJL
SHORT TERM...KRW
LONG TERM...CEM
AVIATION...BJL/KRW
MARINE...BJL/KRW








000
FXUS61 KLWX 211945
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
245 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH TONIGHT. LOW
PRESSURE WILL TRACK UP THE MID-ATLANTIC COAST MONDAY AND TUESDAY.
A STRONG COLD FRONT WILL APPROACH THE AREA WEDNESDAY BEFORE
PASSING THROUGH WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD OVERHEAD
LATE IN THE WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
HIGH PRESSURE REMAINS OVER THE REGION THIS AFTERNOON AND
SUBSIDENCE BEHIND A SHORTWAVE HAS ALLOWED FOR SUNSHINE. HIGH
PRESSURE WILL BECOME CENTERED OVER NEW ENGLAND TONIGHT AND THE
SURFACE RIDGE AXIS WILL DROP SOUTHWEST THROUGH OUR REGION DURING
THIS TIME.

POTENT LOW PRESSURE WILL TRACK THROUGH THE PLAINS TONIGHT THROUGH
MONDAY. A WARM FRONT WILL EXTEND SOUTHEAST FROM THIS SYSTEM
THROUGH THE TENNESSEE VALLEY INTO THE APPALACHIANS WHERE IT WILL
BECOME A STATIONARY FRONT THAT CONTINUES TO EXTEND THROUGH THE
SOUTHEASTERN CONUS. LOW PRESSURE WILL DEVELOP ALONG THIS BOUNDARY
OFF THE SOUTHEAST COAST TONIGHT AND IT IS EXPECTED TO TRACK UP THE
MID-ATLANTIC COAST MONDAY. THIS SYSTEM WILL BE WEAK AND MOST OF
THE DYNAMICS WILL REMAIN WELL TO OUR WEST...CLOSER TO THE STRONGER
LOW OVER THE PLAINS. HOWEVER...WARM AND MOIST AIR FROM THE GULF OF
MEXICO AND ATLANTIC OCEAN WILL OVERRUN THE COLDER AND DRIER AIR
THAT IS CURRENTLY IN PLACE. THIS WILL CAUSE CLOUDS TO INCREASE
OVERNIGHT AND PRECIPITATION IS EXPECTED TO OVERSPREAD AT LEAST
PORTIONS OF THE AREA MONDAY MORNING INTO MONDAY AFTERNOON.

THERE WILL BE ENOUGH COLD AIR FOR POSSIBLE FROZEN PRECIPITATION
MONDAY...ESPECIALLY NORTH AND WEST OF INTERSTATE 95. THE MAIN
IMPACT FROM FROZEN PRECIPITATION WOULD BE FROM FREEZING
RAIN...ALTHOUGH SNOW AND SLEET MAY MIX WITH
PRECIPITATION...ESPECIALLY AT THE ONSET. HOWEVER...THERE IS STILL
SOME UNCERTAINTY AS TO HOW FAR NORTH AND WEST THE PRECIPITATION
WILL MAKE IT SINCE IT WILL BE RUNNING INTO DRIER AIR. THE HIGHEST
CONFIDENCE FOR PRECIPITATION AND SUBFREEZING TEMPERATURES IS
ACROSS CENTRAL VIRGINIA. A FREEZING RAIN ADVISORY IS IN EFFECT FOR
THESE AREAS MONDAY MORNING. FREEZING RAIN MAY CONTINUE INTO THE
AFTERNOON HOURS AS WELL.

FOR THE WASHINGTON AND BALTIMORE METROPOLITAN
AREAS...CONFIDENCE IS NOT YET HIGH ENOUGH FOR A HEADLINE SINCE
TEMPERATURES WILL BE MARGINAL AND IMPACT FROM FROZEN PRECIPITATION
IS NOT EXPECTED TO OCCUR UNTIL LATER MONDAY MORNING OR AFTERNOON.
PRECIPITATION WILL LIKELY OVERSPREAD THESE AREAS DURING THE MID TO
LATE MORNING HOURS MONDAY AND CONTINUE THROUGH MONDAY AFTERNOON.
FROZEN PRECIPITATION IS POSSIBLE...ESPECIALLY NORTH AND WEST OF
INTERSTATE 95. A FREEZING RAIN ADVISORY MAY BE NEEDED FOR PORTIONS
OF THESE AREAS.

FOR THE POTOMAC HIGHLANDS...NORTHERN MARYLAND AND EASTERN WEST
VIRGINIA. TEMPERATURES WILL BE COLD ENOUGH FOR FROZEN
PRECIPITATION...BUT THE NORTHERN AND WESTERN EXTENT OF THE PRECIP
IS TOO UNCERTAIN AT THIS TIME TO ISSUE AN ADVISORY. ANY IMPACT
FROM FROZEN PRECIPITATION WOULD NOT OCCUR UNTIL MONDAY AFTERNOON.

MAX TEMPS MONDAY WILL RANGE FROM THE UPPER 20S AND LOWER 30S
ACROSS THE ALLEGHENY AND POTOMAC HIGHLANDS...TO THE MIDDLE 30S
NEAR WASHINGTON AND BALTIMORE...TO NEAR 40 IN SOUTHERN MARYLAND.

&&

.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
LIGHT PRECIPITATION WILL CONTINUE MONDAY NIGHT INTO TUESDAY MORNING.
THE BIG QUESTION WILL BE HOW LONG THE CAD WEDGE WILL REMAIN IN
PLACE. THERE IS STILL POTENTIAL FOR TEMPERATURES TO REMAIN AT OR
BELOW FREEZING MAINLY WEST OF THE BLUE RIDGE LEAVING THE POTENTIAL
FOR LIGHT FREEZING RAIN TO CONTINUE. TO THE EAST OF THE BLUE RIDGE
AND ACROSS THE METRO AREAS...WARMER AIR WILL LIKELY WIN OUT KEEPING
PRECIPITATION IN THE FORM OF RAIN. A BRIEF RESPITE FROM THE
PRECIPITATION IS POSSIBLE TUESDAY AFTERNOON/EVENING BEFORE THE NEXT
ROUND OF RAINFALL MOVES IN FROM THE WEST LATER TUESDAY NIGHT.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
STRONG COLD FRONT CROSSING THE MID ATLANTIC REGION WEDNESDAY INTO
THURSDAY. LIQUID PRECIPITATION SHOULD ACCOMPANY THE FRONT EXCEPT
ALONG THE ALLEGHENY  FRONT WHERE ARRIVAL OF COLDER AIR WILL CAUSE THE
RAIN TO CHANGE OVER TO SNOW BEFORE PRECIPITATION ENDS THURSDAY.

PASSAGE OF SHORTWAVE WILL SUPPORT DEVELOPMENT OF A COASTAL LOW LATE
SATURDAY AND SUNDAY. PRECIPITATION MAY START AS A WINTRY MIX AT
HIGHER ELEVATIONS.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS THROUGH THIS EVENING. CLOUDS WILL INCREASE
OVERNIGHT AND PRECIPITATION WILL OVERSPREAD THE TERMINALS MONDAY
FROM SOUTHWEST TO NORTHEAST. FREEZING RAIN IS EXPECTED ACROSS KCHO
AND POSSIBLY KMRB AND KIAD. FREEZING RAIN MAY MIX WITH SLEET AND
SNOW AT THE ONSET. RAIN IS EXPECTED ACROSS THE REST OF THE
TERMINALS. RAIN MAY MIX WITH SLEET AT THE ONSET. CIGS/VSBYS WILL
DETERIORATE TO MVFR LEVELS MONDAY WITH POSSIBLE IFR LEVELS.

SUB VFR CIGS AND VSBYS EXPECTED MONDAY NIGHT INTO TUESDAY. LIGHT
FREEZING RAIN WILL BE POSSIBLE WEST OF THE BLUE RIDGE WITH RAIN TO
THE EAST. A PRECIPITATION RESPITE MAY OCCUR TUESDAY AFTERNOON BEFORE
RAIN MOVES BACK IN LATER TUESDAY NIGHT. A STRONG COLD FRONT WILL
APPROACH THE TERMINALS WEDNESDAY BEFORE PASSING THROUGH
WEDNESDAY NIGHT. MORE RAIN AND SUBVFR CONDITIONS ARE EXPECTED.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS TONIGHT. LOW PRESSURE
WILL TRACK UP THE MID-ATLANTIC COAST MONDAY. A SMALL CRAFT
ADVISORY IS IN EFFECT FOR THE MIDDLE PORTIONS OF THE BAY AND LOWER
TIDAL POTOMAC RIVER.

WINDS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA MONDAY NIGHT THROUGH
TUESDAY NIGHT. A STRONG COLD FRONT WILL APPROACH THE WATERS
WEDNESDAY BEFORE PASSING THROUGH WEDNESDAY NIGHT. A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED FOR THE WATERS WEDNESDAY AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...FREEZING RAIN ADVISORY FROM 6 AM TO NOON EST MONDAY FOR VAZ025-
     026-029-036>040-050-051-501>504-507-508.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 AM TO 6 PM EST MONDAY FOR ANZ534-
     537-543.

&&

$$
SYNOPSIS...BJL
NEAR TERM...BJL
SHORT TERM...KRW
LONG TERM...CEM
AVIATION...BJL/KRW
MARINE...BJL/KRW







000
FXUS61 KAKQ 211910
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
210 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY...THEN OFF THE COAST TONIGHT.
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG
THE CAROLINA COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS
THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST ANALYSIS DEPICTS ~1029 MB SFC HIGH PRESSURE CENTERED OVER
DE/MD/ERN VA...WITH A TROUGH OF LOW PRESSURE FROM THE ERN GULF OF
MEXICO TO A POSITION OFF THE SC COAST. SKIES ARE MOSTLY CLOUDY
OVER THE LOCAL AREA (EARLIER CLEAR SKIES ACRS NE NC HAVE SINCE
CLOUDED OVER). LOOKING AT SATELLITE AND 12Z SOUNDINGS AS WELL AS
BUFKIT FORECAST SOUNDINGS...THINK SKIES WILL STAY MAINLY CLOUDY
THROUGH AT LEAST 18Z...WITH PARTIAL CLEARING LATE IN THE AFTN.
HAVE ADJUSTED GRIDS TO GO A LITTLE MORE PESSIMISTIC ON THE CLOUD
COVER TO ACCOUNT FOR THIS. LITTLE CHANGE NEEDED TO
TEMPERATURES...HIGHS AVG AROUND 40 F ON THE ERN SHORE TO THE UPPER
40S OVER SOUTH CENTRAL VA AND NE NC.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
DRY THIS EVENING. CLOUDS QUICKLY THICKEN S-N LATE EVE AND EARLY
MORNING IN RESPONSE TO LOW PRES MOVG NE FROM GOM. TRICKY PART OF FCST
WILL BE HOW FAST PCPN OVERSPREADS THE FA AND WHAT FORM P-TYPE WILL
BE OVR THE PIEDMONT AS IN-SITU WEDGE DVLPS. DESPITE SOME TIMING
DIFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS THE
AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN E OF
I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A NARROW
LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE PIEDMONT.
THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF I95 AND N OF
RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS NEAR FREEZING.
MAY EVEN SEE SOME WET SNOWFLAKES OVER CNTYS NW OF RIC...BUT NOT
SGNFCNT ENUF TO MENTION IN FCST ATTM. QPF LOOKS MINIMAL THRU
12Z...SO ABT THE ONLY ACTION NEEDED AT THIS POINT IS A MENTION IN
HWO. RAIN SRN CNTYS. MIN TMPS MAY LIKELY OCCUR IN THE EVENING WITH
STDY READINGS AFTR MIDNITE. LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN MON MORNING AS HIGH PRES MOVES INTO ERN CANADA.
THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32 DEGREES THRU 15Z
OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA. EXPECT A QUICK TRANSITION
OVER TO ALL RAIN MOST AREAS JUST AFTR 12Z EXCEPT FOR LOUISA/FLUVANNA/
WRN GOOCHLAND/NRN CUMBERLAND CNTYS WHERE A PERIOD OF MIXED SLEET/FZ
RAIN SHUD CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. THESE
ARE THE AREAS WHERE AN ADVISORY MAY BE NEEDED MON MORNING FOR MINIMAL
IMPACT AS TMPS HOVER ARND 32 F. AREAS FROM CAROLINE/NRN HALF OF NRN
NECK CNTYS ON EAST TO DORCHESTER/WICOMICO MD MAY START OFF AS A
RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO RAIN. RAIN THEN BECOMES
WIDESPREAD MON AFTRN AS THE BULK OF LIFT/MSTR TRACKS ACROSS THE
FA. A RATHER COLD RAIN AS TMPS STRUGGLE TO GET OUT OF THE 30S
PIEDMONT...40-45 EAST TOWARD THE ERN SHORE & SERN CHES BAY...
M40S-L50S SERN VA/NC.

LOW PRESSURE PROGGED TO LIFT NE ALONG THE CAROLINA COAST MONDAY NIGHT
WITH STDYST PCPN ENDING SW-NE BY 06Z. SNDGS INDCTG ENUF MSTR FOR LGT
RAIN / DRIZZLE THRU THE OVRNITE HRS. TMPS STDY IN THE M30S NW TO M40S
SE. QPF 1/4 TO 1/2 IN.

MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION TUESDAY. HOWEVER...
MOIST EASTERLY FLOW WILL PREVAIL. KEPT LOW CHC (30%) POPS THRU THE
DAY ALTHOUGH SOME DRIZZLE MAY LINGER THROUGH THE MORNING HRS. BIG
TMP DIFFERENCES SEEN IN MOS DATA WHERE NAM IS SOME 5-10 DEGREES
COLDER THAN THE GFS. GIVEN MODELS MAINTAIN AN ERLY SFC FLOW...WILL
SPLIT THE DIFFERENCE FOR NOW AND GO WITH HIGHS FROM THE M-U40S OVR
THE PIEDMONT TO M-U50S CSTL AREAS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH EARLY MONDAY MORNING. LOW
PRESSURE FORMING OFF THE SC COAST ALONG WITH HIGH PRESSURE WEDGING
SOUTH WILL CREATE A SETUP FOR A COOL/RAINY PERIOD MON MORNING
THROUGH MON NIGHT WITH MVFR/IFR VIS/CIGS EXPECTED. AS THE LOW
MOVES NORTH...OVER-RUNNING PRECIP WILL TRACK S TO N MON MORNING...
EVENTUALLY REACHING EVERY AKQ TAF SITE. EXPECT A BRIEF PERIOD OF
15-20 KT WIND GUSTS ALONG THE COAST AS THE LOW MOVES NORTH AND THE
PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
N-NE WINDS AOB 10 KT WILL PREVAIL TODAY WITH HIGH PRESSURE IN PLACE.
WINDS TURN MORE EASTERLY TONIGHT AND INCREASE TO 10-15 KT MOST AREAS
AS LOW PRESSURE ORGANIZING OFF THE SOUTHEAST COAST SLOWLY PUSHES
NORTH. THE SFC LOW CONTINUES TO MOVE NORTHEAST OF THE NC COAST ON
MONDAY...BUT WEAKENS BY LATE MONDAY/MONDAY NIGHT. WINDS WILL GENERALLY
REMAIN E-NE AOB 15 KT ALL WATERS DURING THIS TIME...BUT TENDING TO
BECOME MORE NORTHERLY AOB 10 KT BY EARLY TUES MORNING. LATEST
GUIDANCE INDICATES POTENTIAL FOR SEAS TO BUILD TO AROUND 5 FT OUT 20
NM LATE MON/MON EVE ACROSS THE SOUTHERN COASTAL WATERS. CONFIDENCE
NOT HIGH ENOUGH TO ISSUE A 3RD PERIOD SCA ATTM.

LIGHT NW WINDS EXPECTED TUES AS HIGH PRESSURE REMAINS IN PLACE OVER
THE MID-ATLANTIC...AND THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE DEEP SOUTH. WINDS TURN E-SE TUESDAY NIGHT AND GRADUALLY BEGIN TO
INCREASE AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. A STRONG
COLD FRONT APPROACHES THE WATERS FROM THE WEST ON WEDNESDAY WITH
WINDS BECOMING SOUTHERLY AND INCREASING TO SCA THRESHOLDS (SAVE THE
RIVERS). THE FRONT QUICKLY SWEEPS THROUGH THE AREA WED NIGHT AND
OFFSHORE EARLY THURSDAY. WINDS REMAIN ABOVE SCA LEVELS THRU LATE
THURSDAY WHILE BECOMING SW THEN W. HIGH PRESSURE RETURNS THU NIGHT
INTO THE START OF NEXT WEEKEND FOR IMPROVED CONDITIONS. SEAS WILL
GENERALLY BUILD TO 5-7 FT ON WED BEFORE SUBSIDING AGAIN LATE THU.
WAVES WILL REACH 4 FT ON THE CHES BAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MPR
NEAR TERM...LKB/MPR
SHORT TERM...MPR
LONG TERM...BMD
AVIATION...DAP
MARINE...JDM






000
FXUS61 KAKQ 211910
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
210 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY...THEN OFF THE COAST TONIGHT.
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG
THE CAROLINA COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS
THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST ANALYSIS DEPICTS ~1029 MB SFC HIGH PRESSURE CENTERED OVER
DE/MD/ERN VA...WITH A TROUGH OF LOW PRESSURE FROM THE ERN GULF OF
MEXICO TO A POSITION OFF THE SC COAST. SKIES ARE MOSTLY CLOUDY
OVER THE LOCAL AREA (EARLIER CLEAR SKIES ACRS NE NC HAVE SINCE
CLOUDED OVER). LOOKING AT SATELLITE AND 12Z SOUNDINGS AS WELL AS
BUFKIT FORECAST SOUNDINGS...THINK SKIES WILL STAY MAINLY CLOUDY
THROUGH AT LEAST 18Z...WITH PARTIAL CLEARING LATE IN THE AFTN.
HAVE ADJUSTED GRIDS TO GO A LITTLE MORE PESSIMISTIC ON THE CLOUD
COVER TO ACCOUNT FOR THIS. LITTLE CHANGE NEEDED TO
TEMPERATURES...HIGHS AVG AROUND 40 F ON THE ERN SHORE TO THE UPPER
40S OVER SOUTH CENTRAL VA AND NE NC.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
DRY THIS EVENING. CLOUDS QUICKLY THICKEN S-N LATE EVE AND EARLY
MORNING IN RESPONSE TO LOW PRES MOVG NE FROM GOM. TRICKY PART OF FCST
WILL BE HOW FAST PCPN OVERSPREADS THE FA AND WHAT FORM P-TYPE WILL
BE OVR THE PIEDMONT AS IN-SITU WEDGE DVLPS. DESPITE SOME TIMING
DIFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS THE
AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN E OF
I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A NARROW
LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE PIEDMONT.
THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF I95 AND N OF
RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS NEAR FREEZING.
MAY EVEN SEE SOME WET SNOWFLAKES OVER CNTYS NW OF RIC...BUT NOT
SGNFCNT ENUF TO MENTION IN FCST ATTM. QPF LOOKS MINIMAL THRU
12Z...SO ABT THE ONLY ACTION NEEDED AT THIS POINT IS A MENTION IN
HWO. RAIN SRN CNTYS. MIN TMPS MAY LIKELY OCCUR IN THE EVENING WITH
STDY READINGS AFTR MIDNITE. LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN MON MORNING AS HIGH PRES MOVES INTO ERN CANADA.
THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32 DEGREES THRU 15Z
OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA. EXPECT A QUICK TRANSITION
OVER TO ALL RAIN MOST AREAS JUST AFTR 12Z EXCEPT FOR LOUISA/FLUVANNA/
WRN GOOCHLAND/NRN CUMBERLAND CNTYS WHERE A PERIOD OF MIXED SLEET/FZ
RAIN SHUD CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. THESE
ARE THE AREAS WHERE AN ADVISORY MAY BE NEEDED MON MORNING FOR MINIMAL
IMPACT AS TMPS HOVER ARND 32 F. AREAS FROM CAROLINE/NRN HALF OF NRN
NECK CNTYS ON EAST TO DORCHESTER/WICOMICO MD MAY START OFF AS A
RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO RAIN. RAIN THEN BECOMES
WIDESPREAD MON AFTRN AS THE BULK OF LIFT/MSTR TRACKS ACROSS THE
FA. A RATHER COLD RAIN AS TMPS STRUGGLE TO GET OUT OF THE 30S
PIEDMONT...40-45 EAST TOWARD THE ERN SHORE & SERN CHES BAY...
M40S-L50S SERN VA/NC.

LOW PRESSURE PROGGED TO LIFT NE ALONG THE CAROLINA COAST MONDAY NIGHT
WITH STDYST PCPN ENDING SW-NE BY 06Z. SNDGS INDCTG ENUF MSTR FOR LGT
RAIN / DRIZZLE THRU THE OVRNITE HRS. TMPS STDY IN THE M30S NW TO M40S
SE. QPF 1/4 TO 1/2 IN.

MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION TUESDAY. HOWEVER...
MOIST EASTERLY FLOW WILL PREVAIL. KEPT LOW CHC (30%) POPS THRU THE
DAY ALTHOUGH SOME DRIZZLE MAY LINGER THROUGH THE MORNING HRS. BIG
TMP DIFFERENCES SEEN IN MOS DATA WHERE NAM IS SOME 5-10 DEGREES
COLDER THAN THE GFS. GIVEN MODELS MAINTAIN AN ERLY SFC FLOW...WILL
SPLIT THE DIFFERENCE FOR NOW AND GO WITH HIGHS FROM THE M-U40S OVR
THE PIEDMONT TO M-U50S CSTL AREAS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH EARLY MONDAY MORNING. LOW
PRESSURE FORMING OFF THE SC COAST ALONG WITH HIGH PRESSURE WEDGING
SOUTH WILL CREATE A SETUP FOR A COOL/RAINY PERIOD MON MORNING
THROUGH MON NIGHT WITH MVFR/IFR VIS/CIGS EXPECTED. AS THE LOW
MOVES NORTH...OVER-RUNNING PRECIP WILL TRACK S TO N MON MORNING...
EVENTUALLY REACHING EVERY AKQ TAF SITE. EXPECT A BRIEF PERIOD OF
15-20 KT WIND GUSTS ALONG THE COAST AS THE LOW MOVES NORTH AND THE
PRESSURE GRADIENT TIGHTENS.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
N-NE WINDS AOB 10 KT WILL PREVAIL TODAY WITH HIGH PRESSURE IN PLACE.
WINDS TURN MORE EASTERLY TONIGHT AND INCREASE TO 10-15 KT MOST AREAS
AS LOW PRESSURE ORGANIZING OFF THE SOUTHEAST COAST SLOWLY PUSHES
NORTH. THE SFC LOW CONTINUES TO MOVE NORTHEAST OF THE NC COAST ON
MONDAY...BUT WEAKENS BY LATE MONDAY/MONDAY NIGHT. WINDS WILL GENERALLY
REMAIN E-NE AOB 15 KT ALL WATERS DURING THIS TIME...BUT TENDING TO
BECOME MORE NORTHERLY AOB 10 KT BY EARLY TUES MORNING. LATEST
GUIDANCE INDICATES POTENTIAL FOR SEAS TO BUILD TO AROUND 5 FT OUT 20
NM LATE MON/MON EVE ACROSS THE SOUTHERN COASTAL WATERS. CONFIDENCE
NOT HIGH ENOUGH TO ISSUE A 3RD PERIOD SCA ATTM.

LIGHT NW WINDS EXPECTED TUES AS HIGH PRESSURE REMAINS IN PLACE OVER
THE MID-ATLANTIC...AND THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE DEEP SOUTH. WINDS TURN E-SE TUESDAY NIGHT AND GRADUALLY BEGIN TO
INCREASE AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. A STRONG
COLD FRONT APPROACHES THE WATERS FROM THE WEST ON WEDNESDAY WITH
WINDS BECOMING SOUTHERLY AND INCREASING TO SCA THRESHOLDS (SAVE THE
RIVERS). THE FRONT QUICKLY SWEEPS THROUGH THE AREA WED NIGHT AND
OFFSHORE EARLY THURSDAY. WINDS REMAIN ABOVE SCA LEVELS THRU LATE
THURSDAY WHILE BECOMING SW THEN W. HIGH PRESSURE RETURNS THU NIGHT
INTO THE START OF NEXT WEEKEND FOR IMPROVED CONDITIONS. SEAS WILL
GENERALLY BUILD TO 5-7 FT ON WED BEFORE SUBSIDING AGAIN LATE THU.
WAVES WILL REACH 4 FT ON THE CHES BAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MPR
NEAR TERM...LKB/MPR
SHORT TERM...MPR
LONG TERM...BMD
AVIATION...DAP
MARINE...JDM







000
FXUS61 KPBZ 211722
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1222 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL THROUGH MONDAY. EXPECT
INCREASING PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN
AND WIND CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES NEEDED TO THE FORECAST FOR TODAY. A FEW BREAKS IN
THE STRATUS DECK ARE EVIDENT IN THE SAT LOOP. CLOUD DECK IS FAIRLY
SHALLOW...EVIDENCED BY VERY DRY AIR ABOVE H700 ON SOUNDING. NEW
NAM RUN SEEMS TO HAVE A GOOD HANDLE ON H850 MOISTURE
CURRENTLY...AND DRIER AIR AT THAT LEVEL IN OHIO IS SET TO ARRIVE
THIS AFTERNOON ON LIGHT W FLOW. THUS...STILL EXPECT A DECREASING
TREND IN CLOUD COVER WITH TIME. TEMPERATURES ON TRACK FOR HIGHS IN
THE LOWER TO MID 30S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
SURFACE HIGH WILL SLIDE EASTWARD TONIGHT...AS WILL THE UPPER LEVEL
RIDGE. WAA WILL GET STARTED MONDAY MORNING AND CONTINUE THROUGHOUT
THE DAY. THE WARMER AIR WILL ALSO PULL MOISTURE NORTHWARD...
INCREASING CLOUDS ONCE AGAIN. BIG QUESTION ON MONDAY IS THE OUTER
EDGE OF THE PRECIP SHIELD THAT IS ASSOCIATED WITH EASTERN SEABOARD
SYSTEM. IT APPEARS THAT SOME OF THIS PRECIP COULD CLIP THE
SOUTHEASTERN RIDGES ON MONDAY. THE PROBLEM WILL BE THE COLD AIR
TRAPPED IN THE RIDGES...THANKS TO THE LOW-LEVEL EASTERLY FLOW.
CONFIDENCE IS LOW HERE...AS MODELS HAVE BOUNCED BACK AND FORTH
WITH HOW FAR WEST TO SPREAD THE PRECIP. THERE IS VERY LITTLE UPPER
LEVEL SUPPORT THIS FAR WEST...BUT WITH THE EASTERLY FLOW...
SHOWERS MAY BE ABLE TO CLIP THE AFOREMENTIONED RIDGES. SURFACE
TEMPS WILL BE CRITICAL...BUT IT DOES APPEAR THAT AT LEAST THE
SHELTERED VALLEYS WILL BE ABLE TO HOLD ON TO TEMPS AT OR BELOW
FREEZING. WILL NEED TO INCLUDE THE MENTION OF FREEZING RAIN IN
THESE AREAS MONDAY.

LOW-LEVEL JET WILL GET STRONG WAA GOING MONDAY NIGHT AND TUESDAY.
STILL TOUGH TO GET A GOOD HANDLE ON HOW MUCH RAIN WILL REACH THE
REGION ON TUESDAY. THE UPPER LEVEL SUPPORT IS WEAK AND
UNORGANIZED...BUT THE LOW-LEVEL JET WILL PULL MOISTURE NORTHWARD
AS WELL. WILL INCREASE RAIN CHANCES FROM WEST TO EAST TUESDAY...BUT
KEEP EVERYTHING IN THE CHANCE CATEGORY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED...GIVEN
THE TIME PERIOD WHICH IT AFFECTS OUR AREA...IS STILL ON TRACK.
LONG RANGE ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE
CONVERGING ON A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.
THIS WILL MAKE FOR ALL LIQUID PRECIPITATION ON THE FRONT END.
TEMPERATURES WILL SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY
WITH 50S COMMON. COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF
MEXICO...SOUNDINGS ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES
TEMP DIFFERENTIAL BETWEEN H8 AND H5 TO NEARLY 0C. THIS COULD LEAD
TO ISOLATED THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE. FOR THE
TIME BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT
FOR BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT. DESPITE
PWATS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT. LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE
PROJECTED QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY. FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST. HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE
GROUND AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME. ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER. EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE. NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS. MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
MVFR CLOUD DECK IS SLOWLY ERODING FROM THE SOUTH. EXPECT ALL SITES
TO ACHIEVE VFR BY 00Z...SAVE FOR POSSIBLY FKL/DUJ WHERE THE CLOUDS
WILL HANG ESPECIALLY TOUGH. VFR THROUGH MOST OF THE
NIGHT...ALTHOUGH SOME MVFR CIGS COULD REDEVELOP TOWARDS DAWN ALONG
THE RIDGES IN SE FLOW. HIGH CLOUDS WILL INCREASE AFTER SUNRISE
MONDAY...AND EXPECT A STRATOCU DECK TO FORM UP WITH TIME. ANY CIGS
SHOULD REMAIN LOW VFR THROUGH 18Z. SPOTTY FREEZING RAIN MAY BE
POSSIBLE IN A FEW VALLEYS IN NORTHEAST WV/WESTERN MD.

OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/... NEXT STORM SYSTEM
WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND RESULT IN
WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF LLWS INTO
THURSDAY.

&&

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

&&

$$






000
FXUS61 KPBZ 211722
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1222 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL THROUGH MONDAY. EXPECT
INCREASING PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN
AND WIND CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES NEEDED TO THE FORECAST FOR TODAY. A FEW BREAKS IN
THE STRATUS DECK ARE EVIDENT IN THE SAT LOOP. CLOUD DECK IS FAIRLY
SHALLOW...EVIDENCED BY VERY DRY AIR ABOVE H700 ON SOUNDING. NEW
NAM RUN SEEMS TO HAVE A GOOD HANDLE ON H850 MOISTURE
CURRENTLY...AND DRIER AIR AT THAT LEVEL IN OHIO IS SET TO ARRIVE
THIS AFTERNOON ON LIGHT W FLOW. THUS...STILL EXPECT A DECREASING
TREND IN CLOUD COVER WITH TIME. TEMPERATURES ON TRACK FOR HIGHS IN
THE LOWER TO MID 30S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
SURFACE HIGH WILL SLIDE EASTWARD TONIGHT...AS WILL THE UPPER LEVEL
RIDGE. WAA WILL GET STARTED MONDAY MORNING AND CONTINUE THROUGHOUT
THE DAY. THE WARMER AIR WILL ALSO PULL MOISTURE NORTHWARD...
INCREASING CLOUDS ONCE AGAIN. BIG QUESTION ON MONDAY IS THE OUTER
EDGE OF THE PRECIP SHIELD THAT IS ASSOCIATED WITH EASTERN SEABOARD
SYSTEM. IT APPEARS THAT SOME OF THIS PRECIP COULD CLIP THE
SOUTHEASTERN RIDGES ON MONDAY. THE PROBLEM WILL BE THE COLD AIR
TRAPPED IN THE RIDGES...THANKS TO THE LOW-LEVEL EASTERLY FLOW.
CONFIDENCE IS LOW HERE...AS MODELS HAVE BOUNCED BACK AND FORTH
WITH HOW FAR WEST TO SPREAD THE PRECIP. THERE IS VERY LITTLE UPPER
LEVEL SUPPORT THIS FAR WEST...BUT WITH THE EASTERLY FLOW...
SHOWERS MAY BE ABLE TO CLIP THE AFOREMENTIONED RIDGES. SURFACE
TEMPS WILL BE CRITICAL...BUT IT DOES APPEAR THAT AT LEAST THE
SHELTERED VALLEYS WILL BE ABLE TO HOLD ON TO TEMPS AT OR BELOW
FREEZING. WILL NEED TO INCLUDE THE MENTION OF FREEZING RAIN IN
THESE AREAS MONDAY.

LOW-LEVEL JET WILL GET STRONG WAA GOING MONDAY NIGHT AND TUESDAY.
STILL TOUGH TO GET A GOOD HANDLE ON HOW MUCH RAIN WILL REACH THE
REGION ON TUESDAY. THE UPPER LEVEL SUPPORT IS WEAK AND
UNORGANIZED...BUT THE LOW-LEVEL JET WILL PULL MOISTURE NORTHWARD
AS WELL. WILL INCREASE RAIN CHANCES FROM WEST TO EAST TUESDAY...BUT
KEEP EVERYTHING IN THE CHANCE CATEGORY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED...GIVEN
THE TIME PERIOD WHICH IT AFFECTS OUR AREA...IS STILL ON TRACK.
LONG RANGE ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE
CONVERGING ON A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.
THIS WILL MAKE FOR ALL LIQUID PRECIPITATION ON THE FRONT END.
TEMPERATURES WILL SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY
WITH 50S COMMON. COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF
MEXICO...SOUNDINGS ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES
TEMP DIFFERENTIAL BETWEEN H8 AND H5 TO NEARLY 0C. THIS COULD LEAD
TO ISOLATED THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE. FOR THE
TIME BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT
FOR BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT. DESPITE
PWATS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT. LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE
PROJECTED QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY. FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST. HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE
GROUND AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME. ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER. EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE. NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS. MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
MVFR CLOUD DECK IS SLOWLY ERODING FROM THE SOUTH. EXPECT ALL SITES
TO ACHIEVE VFR BY 00Z...SAVE FOR POSSIBLY FKL/DUJ WHERE THE CLOUDS
WILL HANG ESPECIALLY TOUGH. VFR THROUGH MOST OF THE
NIGHT...ALTHOUGH SOME MVFR CIGS COULD REDEVELOP TOWARDS DAWN ALONG
THE RIDGES IN SE FLOW. HIGH CLOUDS WILL INCREASE AFTER SUNRISE
MONDAY...AND EXPECT A STRATOCU DECK TO FORM UP WITH TIME. ANY CIGS
SHOULD REMAIN LOW VFR THROUGH 18Z. SPOTTY FREEZING RAIN MAY BE
POSSIBLE IN A FEW VALLEYS IN NORTHEAST WV/WESTERN MD.

OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/... NEXT STORM SYSTEM
WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND RESULT IN
WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF LLWS INTO
THURSDAY.

&&

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

&&

$$







000
FXUS61 KAKQ 211533
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1033 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY...THEN OFF THE COAST TONIGHT.
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG
THE CAROLINA COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS
THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST ANALYSIS DEPICTS ~1029 MB SFC HIGH PRESSURE CENTERED OVER
DE/MD/ERN VA...WITH A TROUGH OF LOW PRESSURE FROM THE ERN GULF OF
MEXICO TO A POSITION OFF THE SC COAST. SKIES ARE MOSTLY CLOUDY
OVER THE LOCAL AREA (EARLIER CLEAR SKIES ACRS NE NC HAVE SINCE
CLOUDED OVER). LOOKING AT SATELLITE AND 12Z SOUNDINGS AS WELL AS
BUFKIT FORECAST SOUNDINGS...THINK SKIES WILL STAY MAINLY CLOUDY
THROUGH AT LEAST 18Z...WITH PARTIAL CLEARING LATE IN THE AFTN.
HAVE ADJUSTED GRIDS TO GO A LITTLE MORE PESSIMISTIC ON THE CLOUD
COVER TO ACCOUNT FOR THIS. LITTLE CHANGE NEEDED TO
TEMPERATURES...HIGHS AVG AROUND 40 F ON THE ERN SHORE TO THE UPPER
40S OVER SOUTH CENTRAL VA AND NE NC.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
DRY THIS EVENING. CLOUDS QUICKLY THICKEN S-N LATE EVE AND EARLY
MORNING IN RESPONSE TO LOW PRES MOVG NE FROM GOM. TRICKY PART OF FCST
WILL BE HOW FAST PCPN OVERSPREADS THE FA AND WHAT FORM P-TYPE WILL
BE OVR THE PIEDMONT AS IN-SITU WEDGE DVLPS. DESPITE SOME TIMING
DIFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS THE
AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN E OF
I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A NARROW
LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE PIEDMONT.
THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF I95 AND N OF
RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS NEAR FREEZING.
MAY EVEN SEE SOME WET SNOWFLAKES OVER CNTYS NW OF RIC...BUT NOT
SGNFCNT ENUF TO MENTION IN FCST ATTM. QPF LOOKS MINIMAL THRU
12Z...SO ABT THE ONLY ACTION NEEDED AT THIS POINT IS A MENTION IN
HWO. RAIN SRN CNTYS. MIN TMPS MAY LIKELY OCCUR IN THE EVENING WITH
STDY READINGS AFTR MIDNITE. LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN MON MORNING AS HIGH PRES MOVES INTO ERN CANADA.
THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32 DEGREES THRU 15Z
OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA. EXPECT A QUICK TRANSITION
OVER TO ALL RAIN MOST AREAS JUST AFTR 12Z EXCEPT FOR LOUISA/FLUVANNA/
WRN GOOCHLAND/NRN CUMBERLAND CNTYS WHERE A PERIOD OF MIXED SLEET/FZ
RAIN SHUD CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. THESE
ARE THE AREAS WHERE AN ADVISORY MAY BE NEEDED MON MORNING FOR MINIMAL
IMPACT AS TMPS HOVER ARND 32 F. AREAS FROM CAROLINE/NRN HALF OF NRN
NECK CNTYS ON EAST TO DORCHESTER/WICOMICO MD MAY START OFF AS A
RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO RAIN. RAIN THEN BECOMES
WIDESPREAD MON AFTRN AS THE BULK OF LIFT/MSTR TRACKS ACROSS THE
FA. A RATHER COLD RAIN AS TMPS STRUGGLE TO GET OUT OF THE 30S
PIEDMONT...40-45 EAST TOWARD THE ERN SHORE & SERN CHES BAY...
M40S-L50S SERN VA/NC.

LOW PRESSURE PROGGED TO LIFT NE ALONG THE CAROLINA COAST MONDAY NIGHT
WITH STDYST PCPN ENDING SW-NE BY 06Z. SNDGS INDCTG ENUF MSTR FOR LGT
RAIN / DRIZZLE THRU THE OVRNITE HRS. TMPS STDY IN THE M30S NW TO M40S
SE. QPF 1/4 TO 1/2 IN.

MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION TUESDAY. HOWEVER...
MOIST EASTERLY FLOW WILL PREVAIL. KEPT LOW CHC (30%) POPS THRU THE
DAY ALTHROUGH SOME DRIZZLE MAY LINGER THROUGH THE MORNING HRS. BIG
TMP DIFFERENCES SEEN IN MOS DATA WHERE NAM IS SOME 5-10 DEGREES
COLDER THAN THE GFS. GIVEN MODELS MAINTAIN AN ERLY SFC FLOW...WILL
SPLIT THE DIFFERENCE FOR NOW AND GO WITH HIGHS FROM THE M-U40S OVR
THE PIEDMONT TO M-U50S CSTL AREAS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS AND LIGHT WINDS EXPECTED TO CONTINUE THROUGH THE
12Z TAF PERIOD. BKN-OVC CLOUDS AROUND 7K FT WILL SLOWLY ERODE
THROUGH LATE MORNING/EARLY AFTN. NEXT BATCH OF PCPN WILL BEGIN TO
ARRIVE FROM SOUTH TO NORTH EARLY MON MORNING.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
N-NE WINDS AOB 10 KT WILL PREVAIL TODAY WITH HIGH PRESSURE IN PLACE.
WINDS TURN MORE EASTERLY TONIGHT AND INCREASE TO 10-15 KT MOST AREAS
AS LOW PRESSURE ORGANIZING OFF THE SOUTHEAST COAST SLOWLY PUSHES
NORTH. THE SFC LOW CONTINUES TO MOVE NORTHEAST OF THE NC COAST ON
MONDAY...BUT WEAKENS BY LATE MONDAY/MONDAY NIGHT. WINDS WILL GENERALLY
REMAIN E-NE AOB 15 KT ALL WATERS DURING THIS TIME...BUT TENDING TO
BECOME MORE NORTHERLY AOB 10 KT BY EARLY TUES MORNING. LATEST
GUIDANCE INDICATES POTENTIAL FOR SEAS TO BUILD TO AROUND 5 FT OUT 20
NM LATE MON/MON EVE ACROSS THE SOUTHERN COASTAL WATERS. CONFIDENCE
NOT HIGH ENOUGH TO ISSUE A 3RD PERIOD SCA ATTM.

LIGHT NW WINDS EXPECTED TUES AS HIGH PRESSURE REMAINS IN PLACE OVER
THE MID-ATLANTIC...AND THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE DEEP SOUTH. WINDS TURN E-SE TUESDAY NIGHT AND GRADUALLY BEGIN TO
INCREASE AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. A STRONG
COLD FRONT APPROACHES THE WATERS FROM THE WEST ON WEDNESDAY WITH
WINDS BECOMING SOUTHERLY AND INCREASING TO SCA THRESHOLDS (SAVE THE
RIVERS). THE FRONT QUICKLY SWEEPS THROUGH THE AREA WED NIGHT AND
OFFSHORE EARLY THURSDAY. WINDS REMAIN ABOVE SCA LEVELS THRU LATE
THURSDAY WHILE BECOMING SW THEN W. HIGH PRESSURE RETURNS THU NIGHT
INTO THE START OF NEXT WEEKEND FOR IMPROVED CONDITIONS. SEAS WILL
GENERALLY BUILD TO 5-7 FT ON WED BEFORE SUBSIDING AGAIN LATE THU.
WAVES WILL REACH 4 FT ON THE CHES BAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MPR
NEAR TERM...LKB/MPR
SHORT TERM...MPR
LONG TERM...BMD
AVIATION...JDM
MARINE...JDM







000
FXUS61 KAKQ 211533
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1033 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY...THEN OFF THE COAST TONIGHT.
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG
THE CAROLINA COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS
THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST ANALYSIS DEPICTS ~1029 MB SFC HIGH PRESSURE CENTERED OVER
DE/MD/ERN VA...WITH A TROUGH OF LOW PRESSURE FROM THE ERN GULF OF
MEXICO TO A POSITION OFF THE SC COAST. SKIES ARE MOSTLY CLOUDY
OVER THE LOCAL AREA (EARLIER CLEAR SKIES ACRS NE NC HAVE SINCE
CLOUDED OVER). LOOKING AT SATELLITE AND 12Z SOUNDINGS AS WELL AS
BUFKIT FORECAST SOUNDINGS...THINK SKIES WILL STAY MAINLY CLOUDY
THROUGH AT LEAST 18Z...WITH PARTIAL CLEARING LATE IN THE AFTN.
HAVE ADJUSTED GRIDS TO GO A LITTLE MORE PESSIMISTIC ON THE CLOUD
COVER TO ACCOUNT FOR THIS. LITTLE CHANGE NEEDED TO
TEMPERATURES...HIGHS AVG AROUND 40 F ON THE ERN SHORE TO THE UPPER
40S OVER SOUTH CENTRAL VA AND NE NC.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
DRY THIS EVENING. CLOUDS QUICKLY THICKEN S-N LATE EVE AND EARLY
MORNING IN RESPONSE TO LOW PRES MOVG NE FROM GOM. TRICKY PART OF FCST
WILL BE HOW FAST PCPN OVERSPREADS THE FA AND WHAT FORM P-TYPE WILL
BE OVR THE PIEDMONT AS IN-SITU WEDGE DVLPS. DESPITE SOME TIMING
DIFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS THE
AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN E OF
I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A NARROW
LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE PIEDMONT.
THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF I95 AND N OF
RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS NEAR FREEZING.
MAY EVEN SEE SOME WET SNOWFLAKES OVER CNTYS NW OF RIC...BUT NOT
SGNFCNT ENUF TO MENTION IN FCST ATTM. QPF LOOKS MINIMAL THRU
12Z...SO ABT THE ONLY ACTION NEEDED AT THIS POINT IS A MENTION IN
HWO. RAIN SRN CNTYS. MIN TMPS MAY LIKELY OCCUR IN THE EVENING WITH
STDY READINGS AFTR MIDNITE. LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN MON MORNING AS HIGH PRES MOVES INTO ERN CANADA.
THE NORMALLY COLDER CNTYS WILL LIKELY STAY NEAR 32 DEGREES THRU 15Z
OR SO AS THE PCPN OVERSPREADS THE ENTIRE FA. EXPECT A QUICK TRANSITION
OVER TO ALL RAIN MOST AREAS JUST AFTR 12Z EXCEPT FOR LOUISA/FLUVANNA/
WRN GOOCHLAND/NRN CUMBERLAND CNTYS WHERE A PERIOD OF MIXED SLEET/FZ
RAIN SHUD CONT THRU AT LEAST 15Z BEFORE TMPS INCH ABV 32 F. THESE
ARE THE AREAS WHERE AN ADVISORY MAY BE NEEDED MON MORNING FOR MINIMAL
IMPACT AS TMPS HOVER ARND 32 F. AREAS FROM CAROLINE/NRN HALF OF NRN
NECK CNTYS ON EAST TO DORCHESTER/WICOMICO MD MAY START OFF AS A
RAIN/SLEET MIX AT THEN QUICKLY GO OVR TO RAIN. RAIN THEN BECOMES
WIDESPREAD MON AFTRN AS THE BULK OF LIFT/MSTR TRACKS ACROSS THE
FA. A RATHER COLD RAIN AS TMPS STRUGGLE TO GET OUT OF THE 30S
PIEDMONT...40-45 EAST TOWARD THE ERN SHORE & SERN CHES BAY...
M40S-L50S SERN VA/NC.

LOW PRESSURE PROGGED TO LIFT NE ALONG THE CAROLINA COAST MONDAY NIGHT
WITH STDYST PCPN ENDING SW-NE BY 06Z. SNDGS INDCTG ENUF MSTR FOR LGT
RAIN / DRIZZLE THRU THE OVRNITE HRS. TMPS STDY IN THE M30S NW TO M40S
SE. QPF 1/4 TO 1/2 IN.

MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION TUESDAY. HOWEVER...
MOIST EASTERLY FLOW WILL PREVAIL. KEPT LOW CHC (30%) POPS THRU THE
DAY ALTHROUGH SOME DRIZZLE MAY LINGER THROUGH THE MORNING HRS. BIG
TMP DIFFERENCES SEEN IN MOS DATA WHERE NAM IS SOME 5-10 DEGREES
COLDER THAN THE GFS. GIVEN MODELS MAINTAIN AN ERLY SFC FLOW...WILL
SPLIT THE DIFFERENCE FOR NOW AND GO WITH HIGHS FROM THE M-U40S OVR
THE PIEDMONT TO M-U50S CSTL AREAS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS AND LIGHT WINDS EXPECTED TO CONTINUE THROUGH THE
12Z TAF PERIOD. BKN-OVC CLOUDS AROUND 7K FT WILL SLOWLY ERODE
THROUGH LATE MORNING/EARLY AFTN. NEXT BATCH OF PCPN WILL BEGIN TO
ARRIVE FROM SOUTH TO NORTH EARLY MON MORNING.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
N-NE WINDS AOB 10 KT WILL PREVAIL TODAY WITH HIGH PRESSURE IN PLACE.
WINDS TURN MORE EASTERLY TONIGHT AND INCREASE TO 10-15 KT MOST AREAS
AS LOW PRESSURE ORGANIZING OFF THE SOUTHEAST COAST SLOWLY PUSHES
NORTH. THE SFC LOW CONTINUES TO MOVE NORTHEAST OF THE NC COAST ON
MONDAY...BUT WEAKENS BY LATE MONDAY/MONDAY NIGHT. WINDS WILL GENERALLY
REMAIN E-NE AOB 15 KT ALL WATERS DURING THIS TIME...BUT TENDING TO
BECOME MORE NORTHERLY AOB 10 KT BY EARLY TUES MORNING. LATEST
GUIDANCE INDICATES POTENTIAL FOR SEAS TO BUILD TO AROUND 5 FT OUT 20
NM LATE MON/MON EVE ACROSS THE SOUTHERN COASTAL WATERS. CONFIDENCE
NOT HIGH ENOUGH TO ISSUE A 3RD PERIOD SCA ATTM.

LIGHT NW WINDS EXPECTED TUES AS HIGH PRESSURE REMAINS IN PLACE OVER
THE MID-ATLANTIC...AND THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE DEEP SOUTH. WINDS TURN E-SE TUESDAY NIGHT AND GRADUALLY BEGIN TO
INCREASE AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. A STRONG
COLD FRONT APPROACHES THE WATERS FROM THE WEST ON WEDNESDAY WITH
WINDS BECOMING SOUTHERLY AND INCREASING TO SCA THRESHOLDS (SAVE THE
RIVERS). THE FRONT QUICKLY SWEEPS THROUGH THE AREA WED NIGHT AND
OFFSHORE EARLY THURSDAY. WINDS REMAIN ABOVE SCA LEVELS THRU LATE
THURSDAY WHILE BECOMING SW THEN W. HIGH PRESSURE RETURNS THU NIGHT
INTO THE START OF NEXT WEEKEND FOR IMPROVED CONDITIONS. SEAS WILL
GENERALLY BUILD TO 5-7 FT ON WED BEFORE SUBSIDING AGAIN LATE THU.
WAVES WILL REACH 4 FT ON THE CHES BAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MPR
NEAR TERM...LKB/MPR
SHORT TERM...MPR
LONG TERM...BMD
AVIATION...JDM
MARINE...JDM






000
FXUS61 KLWX 211443
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
943 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN WEDGED INTO THE MID-ATLANTIC THROUGH
EARLY IN THE WEEK. LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC
COAST LATE MONDAY. A STRONG COLD FRONT WILL THEN PASS THROUGH THE
AREA WEDNESDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE WINTER SOLSTICE IS AT 603PM EST TODAY...SUNDAY DECEMBER 21 2014.
THE SUN WILL BE AT THE LOWEST ANGLE OF THE YEAR WITH THE LEAST
AMOUNT OF DAYLIGHT.

A SHORTWAVE IS PASSING BY TO OUR NORTH THIS MORNING WHILE SURFACE
HIGH PRESSURE REMAINS OVERHEAD. LOW-LEVEL MOISTURE TRAPPED
UNDERNEATH THE SUBSIDENCE INVERSION HAS CAUSED PLENTY OF CLOUDS.
HOWEVER...SUBSIDENCE BEHIND THE DEPARTING SHORTWAVE SHOULD ALLOW
FOR CLOUDS TO GIVE WAY TO SUNSHINE THIS AFTERNOON. MAX TEMPS WILL
BE NEAR CLIMO...RANGING FROM THE UPPER 20S AND LOWER 30S IN THE
MOUNTAINS TO THE LOWER 40S NEAR WASHINGTON AND BALTIMORE. SHOULD
CLOUDS HANG ON LONGER THAN EXPECTED...TEMPS WILL REMAIN IN THE 30S
FOR THE WASHINGTON AND BALTIMORE METROPOLITAN AREAS.

HIGH PRESSURE WILL BEGIN TO WEDGE AGAINST THE APPALACHIAN REGION
TONIGHT AS AN UPPER LEVEL TROUGH BEGINS TO AMPLIFY ACROSS THE
CENTRAL US. THE JET STREAM ACROSS THE SE US WILL LEAD TO THE
DEVELOPMENT OF LOW PRESSURE OFF THE CAROLINA COAST. MOISTURE
ADVECTION INTO THE MID-ATLANTIC WILL LEAD TO PRECIPITATION MOVING
INTO THE REGION FROM THE SOUTH LATE TONIGHT. WENT WITH THE SREF
MEAN FOR PRECIP PROGRESSION. AT THIS TIME...MOISTURE SHOULD BE
REACHING THE GROUND ACROSS THE CENTRAL FOOTHILLS...SHENANDOAH
VALLEY...PIEDMONT EARLY MONDAY MORNING. HIGH PRESSURE WILL SERVE
AS A SOURCE OF COLD AIR AT THE SFC WITH TEMPS REACHING THE UPPER
20S TO AROUND 30 BY MONDAY MORNING. 850-700MB THICKNESS VALUES
AROUND 1550M UP TO I-66 AND 1000-850MB THICKNESS VALUES AROUND
1310 WOULD RESULT IN FZRA...SLEET MIXTURE EARLY MONDAY MORNING IF
MOISTURE IS AVAILABLE. TEMPS ALONG AND WEST OF THE BLUE RIDGE ARE
EXPECTED TO BE COLDER RESULTING IN A BETTER CHANCE FOR ICE
ACCRETION.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
STILL HAVE SOME UNCERTAINTY REGARDING THE DETAILS OF MONDAY/MONDAY
NIGHT. GENERAL IDEA IS THAT PRECIP WILL SPREAD NORTHWARD THROUGH THE
CWA DURING THE DAY MONDAY...ALTHOUGH THE EXACT NORTH/NORTHWEST
EXTENT REMAINS SOMEWHAT IN QUESTION. ALSO IN QUESTION WILL BE TIMING
THE CHANGES TO THE THERMAL PROFILE THROUGH THE DAY...WHICH WILL
DETERMINE P-TYPE.

PREFER GENERAL IDEA FROM THE SREFS FOR POPS...ALTHOUGH POPS NOT
QUITE AS HIGH FURTHER NORTH TOWARD THE MASON DIXON LINE. LEANED
TOWARD SREFS FOR TEMPERATURE/PROFILE CONSIDERATIONS TOO. THIS
SUGGESTS THAT INITIAL PRECIP MAY BE SLEET OR FREEZING
RAIN...TRENDING TO JUST RAIN THROUGHOUT THE DAY ALTHOUGH WINTRY
PRECIP COULD LINGER LONGER OVER THE POTOMAC HIGHLANDS. HIGHEST
CONFIDENCE FOR ICING RESIDES ACROSS THE LOWER POTOMAC
HIGHLANDS/SHENANDOAH VALLEY/CENTRAL VA FOOTHILLS.

RISK OF FREEZING RAIN COULD CONTINUE OVER THE POTOMAC HIGHLANDS
MONDAY NIGHT ASSUMING THERE IS PRECIPITATION FALLING...BUT THIS IS
UNCERTAIN AS MODELS SUGGEST THE MAIN BATCH OF QPF LIFTS NORTHEAST IN
TANDEM WITH WEAK LOW PRESSURE OFF THE COAST.

WEDGE REMAINS IN PLACE TUESDAY. NOT SURE THERE/S A LOT OF MEASURABLE
PRECIP GOING ON...IT MAY BE MORE DRIZZLE BUT CONTINUE CHANCE POPS
FOR RAIN ACROSS THE CWA WITH GFS SHOWING BROAD LIGHT QPF. AM
EXPECTING ANY PRECIPITATION TO BE IN LIQUID FORM DURING THE DAY
TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
FOCUS THEN SHIFTS TO DEEP UPPER TROUGH/STRONG COLD FRONT OVER THE
MIDWEST/OHIO VALLEY TUESDAY NIGHT. DECENT PLUME OF MOISTURE
OVERRUNNING A WARM FRONT WILL BRING RAIN INTO THE MID-ATLANTIC
TUESDAY NIGHT.

AS LOW LEVEL JET STRENGTHENS ON WEDNESDAY...THIS SHOULD HELP TO PUSH
THE WARM FRONT TO THE NORTH. PW/S MAY INCREASE NEAR 1.5
INCHES...LIKELY LEADING TO PERIODS OF MODERATE RAINFALL ON
WEDNESDAY. INSTABILITY IS FORECAST TO BE WEAK SO NO THUNDER
MENTIONED BUT POTENTIAL EXISTS FOR SOME GUSTY SHOWERS GIVEN WIND
FIELDS OFF THE DECK. DESPITE CLOUDS/RAIN...MAXIMA SHOULD WARM WELL
INTO THE 50S AND POSSIBLY ECLIPSE 60 IN SOME AREAS.

STRONG COLD FRONT MOVES THROUGH WEDNESDAY NIGHT. SHOWERS END FROM
WEST TO EAST...AND COLD ADVECTION/TIGHT PRESSURE GRADIENT WILL BRING
A BLUSTERY AND COOLER DAY THURSDAY /MEX GUIDANCE LIKELY TOO WARM/.
NEXT COLD FRONT APPROACHES FRIDAY NIGHT OR SATURDAY.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS EXPECTED THROUGH TONIGHT. MID LEVEL MOISTURE WILL
CONTINUE TO MOVE EASTWARD ACROSS THE REGION RESULTING IN BKN-OVC
VFR CIGS. CLEARING IS EXPECTED BY THIS AFTERNOON WITH A SCT-BKN 5K
FEET DECK EXPECTED INTO THE EVENING. CLOUDS WILL BUILD IN FROM THE
SOUTH TONIGHT AS LOW PRESSURE DEVELOPS OFF THE EAST COAST.
MVFR/IFR CIGS SHOULD REACH CHO BY MONDAY MORNING. LIGHT NRLY WINDS
EXPECTED DURING THE TAF PERIOD.

PRECIP SPREADS NORTH ON MONDAY...POSSIBLY BEGINNING AS A WINTRY MIX
OF -IP/-ZR BEFORE TRANSITIONING TO -RA. MVFR CONDITIONS LIKELY ON
MONDAY WITH PRECIP...DEGRADING INTO IFR/LIFR MONDAY NIGHT INTO
TUESDAY. RESTRICTIONS CONTINUE INTO WEDNESDAY WITH SHOWERS AND
POSSIBLE LLWS. COLD FRONT MOVES THROUGH WEDNESDAY NIGHT...WITH GUSTY
SURFACE WINDS THURSDAY.

&&

.MARINE...
LIGHT NRLY WINDS EXPECTED ON THE WATERS THROUGH TONIGHT. WINDS
WILL REMAIN LIGHT BUT BECOME EASTERLY LATE TONIGHT AND INTO MONDAY
MORNING. RAIN AND/OR SLEET SHOULD REACH THE SRN WATERS MONDAY
MORNING BEFORE CHANGING TO ALL RAIN THROUGH MONDAY.

SCA CONDITIONS ARE POSSIBLE IN SOUTHERLY FLOW AHEAD OF A COLD FRONT
ON WEDNESDAY...THEN BEHIND THE FRONT FOR WEDNESDAY NIGHT AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BPP/HAS
NEAR TERM...BJL/HAS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...BJL/BPP/HAS
MARINE...BJL/BPP/HAS







000
FXUS61 KLWX 211443
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
943 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN WEDGED INTO THE MID-ATLANTIC THROUGH
EARLY IN THE WEEK. LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC
COAST LATE MONDAY. A STRONG COLD FRONT WILL THEN PASS THROUGH THE
AREA WEDNESDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE WINTER SOLSTICE IS AT 603PM EST TODAY...SUNDAY DECEMBER 21 2014.
THE SUN WILL BE AT THE LOWEST ANGLE OF THE YEAR WITH THE LEAST
AMOUNT OF DAYLIGHT.

A SHORTWAVE IS PASSING BY TO OUR NORTH THIS MORNING WHILE SURFACE
HIGH PRESSURE REMAINS OVERHEAD. LOW-LEVEL MOISTURE TRAPPED
UNDERNEATH THE SUBSIDENCE INVERSION HAS CAUSED PLENTY OF CLOUDS.
HOWEVER...SUBSIDENCE BEHIND THE DEPARTING SHORTWAVE SHOULD ALLOW
FOR CLOUDS TO GIVE WAY TO SUNSHINE THIS AFTERNOON. MAX TEMPS WILL
BE NEAR CLIMO...RANGING FROM THE UPPER 20S AND LOWER 30S IN THE
MOUNTAINS TO THE LOWER 40S NEAR WASHINGTON AND BALTIMORE. SHOULD
CLOUDS HANG ON LONGER THAN EXPECTED...TEMPS WILL REMAIN IN THE 30S
FOR THE WASHINGTON AND BALTIMORE METROPOLITAN AREAS.

HIGH PRESSURE WILL BEGIN TO WEDGE AGAINST THE APPALACHIAN REGION
TONIGHT AS AN UPPER LEVEL TROUGH BEGINS TO AMPLIFY ACROSS THE
CENTRAL US. THE JET STREAM ACROSS THE SE US WILL LEAD TO THE
DEVELOPMENT OF LOW PRESSURE OFF THE CAROLINA COAST. MOISTURE
ADVECTION INTO THE MID-ATLANTIC WILL LEAD TO PRECIPITATION MOVING
INTO THE REGION FROM THE SOUTH LATE TONIGHT. WENT WITH THE SREF
MEAN FOR PRECIP PROGRESSION. AT THIS TIME...MOISTURE SHOULD BE
REACHING THE GROUND ACROSS THE CENTRAL FOOTHILLS...SHENANDOAH
VALLEY...PIEDMONT EARLY MONDAY MORNING. HIGH PRESSURE WILL SERVE
AS A SOURCE OF COLD AIR AT THE SFC WITH TEMPS REACHING THE UPPER
20S TO AROUND 30 BY MONDAY MORNING. 850-700MB THICKNESS VALUES
AROUND 1550M UP TO I-66 AND 1000-850MB THICKNESS VALUES AROUND
1310 WOULD RESULT IN FZRA...SLEET MIXTURE EARLY MONDAY MORNING IF
MOISTURE IS AVAILABLE. TEMPS ALONG AND WEST OF THE BLUE RIDGE ARE
EXPECTED TO BE COLDER RESULTING IN A BETTER CHANCE FOR ICE
ACCRETION.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
STILL HAVE SOME UNCERTAINTY REGARDING THE DETAILS OF MONDAY/MONDAY
NIGHT. GENERAL IDEA IS THAT PRECIP WILL SPREAD NORTHWARD THROUGH THE
CWA DURING THE DAY MONDAY...ALTHOUGH THE EXACT NORTH/NORTHWEST
EXTENT REMAINS SOMEWHAT IN QUESTION. ALSO IN QUESTION WILL BE TIMING
THE CHANGES TO THE THERMAL PROFILE THROUGH THE DAY...WHICH WILL
DETERMINE P-TYPE.

PREFER GENERAL IDEA FROM THE SREFS FOR POPS...ALTHOUGH POPS NOT
QUITE AS HIGH FURTHER NORTH TOWARD THE MASON DIXON LINE. LEANED
TOWARD SREFS FOR TEMPERATURE/PROFILE CONSIDERATIONS TOO. THIS
SUGGESTS THAT INITIAL PRECIP MAY BE SLEET OR FREEZING
RAIN...TRENDING TO JUST RAIN THROUGHOUT THE DAY ALTHOUGH WINTRY
PRECIP COULD LINGER LONGER OVER THE POTOMAC HIGHLANDS. HIGHEST
CONFIDENCE FOR ICING RESIDES ACROSS THE LOWER POTOMAC
HIGHLANDS/SHENANDOAH VALLEY/CENTRAL VA FOOTHILLS.

RISK OF FREEZING RAIN COULD CONTINUE OVER THE POTOMAC HIGHLANDS
MONDAY NIGHT ASSUMING THERE IS PRECIPITATION FALLING...BUT THIS IS
UNCERTAIN AS MODELS SUGGEST THE MAIN BATCH OF QPF LIFTS NORTHEAST IN
TANDEM WITH WEAK LOW PRESSURE OFF THE COAST.

WEDGE REMAINS IN PLACE TUESDAY. NOT SURE THERE/S A LOT OF MEASURABLE
PRECIP GOING ON...IT MAY BE MORE DRIZZLE BUT CONTINUE CHANCE POPS
FOR RAIN ACROSS THE CWA WITH GFS SHOWING BROAD LIGHT QPF. AM
EXPECTING ANY PRECIPITATION TO BE IN LIQUID FORM DURING THE DAY
TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
FOCUS THEN SHIFTS TO DEEP UPPER TROUGH/STRONG COLD FRONT OVER THE
MIDWEST/OHIO VALLEY TUESDAY NIGHT. DECENT PLUME OF MOISTURE
OVERRUNNING A WARM FRONT WILL BRING RAIN INTO THE MID-ATLANTIC
TUESDAY NIGHT.

AS LOW LEVEL JET STRENGTHENS ON WEDNESDAY...THIS SHOULD HELP TO PUSH
THE WARM FRONT TO THE NORTH. PW/S MAY INCREASE NEAR 1.5
INCHES...LIKELY LEADING TO PERIODS OF MODERATE RAINFALL ON
WEDNESDAY. INSTABILITY IS FORECAST TO BE WEAK SO NO THUNDER
MENTIONED BUT POTENTIAL EXISTS FOR SOME GUSTY SHOWERS GIVEN WIND
FIELDS OFF THE DECK. DESPITE CLOUDS/RAIN...MAXIMA SHOULD WARM WELL
INTO THE 50S AND POSSIBLY ECLIPSE 60 IN SOME AREAS.

STRONG COLD FRONT MOVES THROUGH WEDNESDAY NIGHT. SHOWERS END FROM
WEST TO EAST...AND COLD ADVECTION/TIGHT PRESSURE GRADIENT WILL BRING
A BLUSTERY AND COOLER DAY THURSDAY /MEX GUIDANCE LIKELY TOO WARM/.
NEXT COLD FRONT APPROACHES FRIDAY NIGHT OR SATURDAY.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS EXPECTED THROUGH TONIGHT. MID LEVEL MOISTURE WILL
CONTINUE TO MOVE EASTWARD ACROSS THE REGION RESULTING IN BKN-OVC
VFR CIGS. CLEARING IS EXPECTED BY THIS AFTERNOON WITH A SCT-BKN 5K
FEET DECK EXPECTED INTO THE EVENING. CLOUDS WILL BUILD IN FROM THE
SOUTH TONIGHT AS LOW PRESSURE DEVELOPS OFF THE EAST COAST.
MVFR/IFR CIGS SHOULD REACH CHO BY MONDAY MORNING. LIGHT NRLY WINDS
EXPECTED DURING THE TAF PERIOD.

PRECIP SPREADS NORTH ON MONDAY...POSSIBLY BEGINNING AS A WINTRY MIX
OF -IP/-ZR BEFORE TRANSITIONING TO -RA. MVFR CONDITIONS LIKELY ON
MONDAY WITH PRECIP...DEGRADING INTO IFR/LIFR MONDAY NIGHT INTO
TUESDAY. RESTRICTIONS CONTINUE INTO WEDNESDAY WITH SHOWERS AND
POSSIBLE LLWS. COLD FRONT MOVES THROUGH WEDNESDAY NIGHT...WITH GUSTY
SURFACE WINDS THURSDAY.

&&

.MARINE...
LIGHT NRLY WINDS EXPECTED ON THE WATERS THROUGH TONIGHT. WINDS
WILL REMAIN LIGHT BUT BECOME EASTERLY LATE TONIGHT AND INTO MONDAY
MORNING. RAIN AND/OR SLEET SHOULD REACH THE SRN WATERS MONDAY
MORNING BEFORE CHANGING TO ALL RAIN THROUGH MONDAY.

SCA CONDITIONS ARE POSSIBLE IN SOUTHERLY FLOW AHEAD OF A COLD FRONT
ON WEDNESDAY...THEN BEHIND THE FRONT FOR WEDNESDAY NIGHT AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BPP/HAS
NEAR TERM...BJL/HAS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...BJL/BPP/HAS
MARINE...BJL/BPP/HAS








000
FXUS61 KPHI 211433
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
933 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER QUEBEC TODAY WILL DRIFT EASTWARD AND
IT SHOULD REACH ATLANTIC CANADA ON MONDAY. WEAK LOW PRESSURE IS
FORECAST TO DEVELOP OFF THE CAROLINA COAST ON MONDAY BEFORE MOVING
SLOWLY NORTHEASTWARD AND DISSIPATING OFF THE DELMARVA PENINSULA ON
TUESDAY. LOW PRESSURE IS EXPECTED TO DEVELOP AROUND THE CENTRAL
GULF COAST REGION ON TUESDAY. THE LOW SHOULD STRENGTHEN AS IT
LIFTS NORTHWARD AND ACROSS THE EASTERN GREAT LAKES ON WEDNESDAY
NIGHT. THE LOW IS ANTICIPATED TO PULL A WARM FRONT THROUGH OUR
REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT LATE ON WEDNESDAY
NIGHT. HIGH PRESSURE IS EXPECTED TO FOLLOW FROM THE SOUTHWEST FOR
THURSDAY AND FRIDAY. ANOTHER COLD FRONT FROM THE WEST IS FORECAST
TO ARRIVE ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE CENTER OF A 1030 MB SURFACE HIGH WAS ANALYZED OVER EASTERN
CANADA AT 14Z THIS MORNING. THIS BROAD AREA OF HIGH PRESSURE
ENCOMPASSES MOST OF THE EASTERN SEABOARD. THE PRESSURE GRADIENT
AND RESULTANT WINDS WILL BE LIGHT OVER THE MID-ATLANTIC REGION
TODAY UNDER THIS SETUP.

STRATOCU STILL HOLDING STRONG OVER NORTHEAST PA AND NORTHERN NJ THIS
MORNING, WHERE HIGHER MOISTURE IN ASSOCIATION WITH A PASSING
SHORTWAVE TROUGH TO OUR NORTHEAST REMAINS TRAPPED BELOW THE
SUBSIDENCE INVERSION AT AROUND 900 MB. THE DELMARVA IS POSITIONED IN
THE RIGHT ENTRANCE REGION OF MID-LEVEL JET STREAK, RESULTING IN
OVERCAST MID CLOUDS IN OUR SOUTHERN ZONES. HOWEVER, THERE IS A
BAND OF CLEARING EVIDENT ON THE LATEST VISIBLE SATELLITE IMAGERY
IN THE MIDDLE PART OF THE CWA THAT IS DEVELOPING OVER SOUTHEAST
PA, INCLUDING PHILLY AND ADJACENT CENTRAL/SOUTHERN NJ MID
MORNING. THE CLEARING SHOULD EXPAND SOUTH AND EASTWARD THRUOUT THE
DAY AS THE JET STREAK PROGRESSES OFF THE COAST, ALTHOUGH THE
HEATING WILL LEAD TO DEVELOPMENT OF SCATTERED STRATOCU. CLOUDS
SHOULD BE SLOWER TO ERODE OVER NORTHEAST PA AND NORTHWEST NJ THRU
MIDDAY, BUT SOME SUN IS ANTICIPATED LATER IN THE AFTERNOON.

ONLY MADE MINOR ADJUSTMENTS TO THE MAX TEMP FORECAST BASED OFF
CHANGES MADE TO THE SKY GRIDS. MAX TEMPS RANGE FROM THE LOWER 30S IN
THE POCONOS TO AROUND 40F IN PHILLY, SOUTHERN NJ AND THE DELMARVA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE HIGH PRESSURE BEGINS TO RETREAT SOME OVERNIGHT TONIGHT, BUT
OUR AREA WILL STILL REMAIN ON THE SOUTHERN FRINGE. ANY PARTIAL
CLEARING THAT OCCURRED DURING THE DAY WILL CONTINUE INTO THE
EVENING, BUT HIGH LEVEL CLOUD COVER MAY BEGIN TO DEVELOP AND
SPREAD BACK INTO THE AREA OVERNIGHT AS A WEAK SHORT WAVE LIFTS
THROUGH THE AREA. WE ARE NOT EXPECTING ANY PRECIPITATION OVERNIGHT
AS THERE IS A LACK OF SIGNIFICANT VERTICAL MOISTURE.

LOW TEMPERATURES ARE A BLEND OF MAV/MET MOS AND MOSGUIDE WHICH
WERE ALL IN PRETTY GOOD AGREEMENT.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A MID LEVEL RIDGE AXIS SHOULD BE TO OUR EAST ON MONDAY. AN
IMPULSE TRAVELING IN THE MID LEVEL FLOW IS EXPECTED TO PASS
OVERHEAD ON MONDAY AFTERNOON. MOISTURE IS FORECAST TO SPREAD INTO
OUR REGION FROM THE SOUTH AT THAT TIME. WE HAVE MENTIONED A CHANCE
OF RAIN ARRIVING FROM SOUTH TO NORTH FROM THE LATE MORNING INTO
THE AFTERNOON HOURS. THE FORECAST TEMPERATURE PROFILES SUGGEST
THAT THE BOUNDARY LAYER WILL BE ABLE TO SUPPORT ALL RAIN EVEN UP
NORTH WHERE THE CHANCE FOR PRECIPITATION IS THE LOWEST IN OUR
REGION.

SURFACE HIGH PRESSURE IS FORECAST TO BE LOCATED OVER ATLANTIC
CANADA FROM MONDAY INTO TUESDAY. A RIDGE AXIS IS EXPECTED TO NOSE
SOUTHWESTWARD ALONG THE LEE OF THE APPALACHIANS AT THAT TIME WITH
AN INVERTED TROUGH DEVELOPING OFF THE COAST. WEAK LOW PRESSURE IS
ANTICIPATED TO DEVELOP ON THE TROUGH OFF THE CAROLINA COAST ON
MONDAY. THE FEATURE IS FORECAST TO REMAIN WEAK AS IT DRIFTS
NORTHEASTWARD REACHING THE WATERS OFF THE DELMARVA PENINSULA
BEFORE DISSIPATING ON TUESDAY.

MEANWHILE, A DEEP MID LEVEL TROUGH IS EXPECTED TO DIG OVER THE
MIDDLE PART OF THE COUNTRY ON MONDAY AND TUESDAY AS THE RIDGE OVER
THE WESTERN NORTH ATLANTIC BECOMES MORE PRONOUNCED. THE PATTERN
WILL RESULT IN THE DEVELOPMENT OF STRONG WARM ADVECTION OVER OUR
REGION FROM TUESDAY INTO TUESDAY NIGHT.

THE PATTERN SHOULD KEEP OUR REGION OVERCAST WITH A CHANCE OF RAIN
FROM MONDAY NIGHT INTO TUESDAY WITH THE PROBABILITY OF
PRECIPITATION INCREASING TO LIKELY FOR TUESDAY NIGHT. IT CONTINUES
TO APPEAR AS THOUGH THERE MAY BE POCKETS OF BELOW FREEZING
TEMPERATURES IN THE POCONOS AND IN FAR NORTHERN NEW JERSEY FROM
MONDAY NIGHT INTO TUESDAY MORNING TO POSSIBLY RESULT IN SOME
LOCALIZED LIGHT FREEZING RAIN.

SURFACE LOW PRESSURE IS ANTICIPATED TO DEVELOP AROUND THE CENTRAL
GULF COAST REGION ON TUESDAY IN RESPONSE TO THE DEEP MID LEVEL
TROUGH. THE LOW IS FORECAST TO STRENGTHEN AS IT MOVES NORTHWARD ON
WEDNESDAY AND ACROSS THE EASTERN GREAT LAKES ON WEDNESDAY NIGHT.
THE SYSTEM SHOULD HAVE AN OPPORTUNITY TO TAP INTO GULF MOISTURE
AND IT WILL BRING THE POTENTIAL FOR SOME MODERATE TO HEAVY
RAINFALL TO OUR REGION FROM LATE TUESDAY NIGHT INTO EARLY
WEDNESDAY NIGHT. THE CONSENSUS OF THE MODELS CONTINUES TO SUGGEST
REPRESENTATIVE RAINFALL AMOUNTS UP TO AN INCH TO AN INCH AND A
HALF IN OUR REGION DURING THE MID WEEK PERIOD.

THE LOW IS EXPECTED TO PULL A WARM FRONT THROUGH OUR REGION ON
WEDNESDAY WITH TEMPERATURES FORECAST TO RISE INTO THE 50S AND
LOWER 60S. A STRONG COLD FRONT IS FORECAST TO FOLLOW LATE ON
WEDNESDAY NIGHT WITH TEMPERATURES DROPPING BACK INTO THE UPPER 30S
AND LOWER 40S BY DAYBREAK ON THURSDAY. THE PROBABILITY OF
PRECIPITATION DECREASES RAPIDLY LATE ON WEDNESDAY NIGHT AS DRY AIR
IS EXPECTED TO BEGIN BUILDING INTO OUR REGION FROM THE WEST AND
SOUTHWEST. CONDITIONS ARE ANTICIPATED TO BECOME QUITE BREEZY IN
THE WAKE OF THE COLD FRONT FOR CHRISTMAS DAY. A WEST WIND AROUND
15 TO 20 MPH IS FORECAST WITH GUSTS NEAR 30 MPH. TEMPERATURES
SHOULD RETURN TO SEASONABLE LEVELS FOR THURSDAY, FRIDAY AND
SATURDAY.

RIDGING IS FORECAST TO DEVELOP AT THE SURFACE AND ALOFT FOR
THURSDAY NIGHT INTO FRIDAY WITH DRY WEATHER ANTICIPATED.

A MID LEVEL SHORT WAVE IS EXPECTED TO APPROACH FROM THE WEST
ALONG WITH AN ASSOCIATED SURFACE COLD FRONT. THE FRONT IS FORECAST
TO PASS THROUGH OUR REGION ON SATURDAY. THE SYSTEM IS FORECAST TO
BE FAST MOVING AND IT SHOULD NOT HAVE MUCH OF AN OPPORTUNITY TO
TAP INTO A MOISTURE SOURCE. AS A RESULT, WE WILL NOT FORECAST ANY
PRECIPITATION WITH THE FRONT AT THIS TIME.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

VFR TODAY. CLEARING HAS ALREADY OCCURRED ACROSS PHILLY AREA
TERMINALS THIS MORNING WHILE ABE REMAINS OVC JUST ABOVE 3000 FT.
EXPECT SCT CIGS AROUND 3 KFT THIS AFTN FOR ALL TERMINALS. WINDS
WILL BE LIGHT (BELOW 10 KT). WINDS WILL BECOME LIGHT AND
VARIABLE/CALM ONCE AGAIN TONIGHT.

OUTLOOK...
MONDAY...MAINLY VFR WITH A CHANCE OF LIGHT RAIN SPREADING
NORTHWARD INTO OUR REGION.

MONDAY NIGHT AND TUESDAY...CONDITIONS POSSIBLY LOWERING INTO THE
MVFR CATEGORY WITH A CHANCE OF LIGHT RAIN.

TUESDAY NIGHT...MVFR AND IFR CONDITIONS ANTICIPATED WITH RAIN
LIKELY.

WEDNESDAY AND WEDNESDAY NIGHT...MVFR AND IFR CONDITIONS WITH RAIN
LIKELY. THE RAIN MAY BE HEAVY AT TIMES.

THURSDAY...CONDITIONS IMPROVING TO VFR WITH A GUSTY WEST WIND.

&&

.MARINE...
SUB-SMALL CRAFT ADVISORY CONDITIONS WILL REMAIN TODAY INTO
TONIGHT AS HIGH PRESSURE FROM THE NORTH WILL CONTINUE TO AFFECT
THE WATERS.

OUTLOOK...
MONDAY AND MONDAY NIGHT...NO MARINE HEADLINES ARE ANTICIPATED.

TUESDAY AND TUESDAY NIGHT...WAVE HEIGHTS ON OUR OCEAN WATERS MAY
BUILD TO 5 FEET IN A DEVELOPING ONSHORE FLOW.

WEDNESDAY...SOUTHERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 6 TO 9
FEET.

WEDNESDAY NIGHT...A SOUTH WIND BECOMING WEST. WIND GUSTS IN
EXCESS OF 25 KNOTS ARE EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS
MAY BE TO 6 TO 9 FEET.

THURSDAY...WESTERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BE TO 5 TO 7 FEET.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...IOVINO
NEAR TERM...KLEIN
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/KLEIN/ROBERTSON
MARINE...IOVINO/ROBERTSON






000
FXUS61 KPHI 211433
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
933 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER QUEBEC TODAY WILL DRIFT EASTWARD AND
IT SHOULD REACH ATLANTIC CANADA ON MONDAY. WEAK LOW PRESSURE IS
FORECAST TO DEVELOP OFF THE CAROLINA COAST ON MONDAY BEFORE MOVING
SLOWLY NORTHEASTWARD AND DISSIPATING OFF THE DELMARVA PENINSULA ON
TUESDAY. LOW PRESSURE IS EXPECTED TO DEVELOP AROUND THE CENTRAL
GULF COAST REGION ON TUESDAY. THE LOW SHOULD STRENGTHEN AS IT
LIFTS NORTHWARD AND ACROSS THE EASTERN GREAT LAKES ON WEDNESDAY
NIGHT. THE LOW IS ANTICIPATED TO PULL A WARM FRONT THROUGH OUR
REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT LATE ON WEDNESDAY
NIGHT. HIGH PRESSURE IS EXPECTED TO FOLLOW FROM THE SOUTHWEST FOR
THURSDAY AND FRIDAY. ANOTHER COLD FRONT FROM THE WEST IS FORECAST
TO ARRIVE ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE CENTER OF A 1030 MB SURFACE HIGH WAS ANALYZED OVER EASTERN
CANADA AT 14Z THIS MORNING. THIS BROAD AREA OF HIGH PRESSURE
ENCOMPASSES MOST OF THE EASTERN SEABOARD. THE PRESSURE GRADIENT
AND RESULTANT WINDS WILL BE LIGHT OVER THE MID-ATLANTIC REGION
TODAY UNDER THIS SETUP.

STRATOCU STILL HOLDING STRONG OVER NORTHEAST PA AND NORTHERN NJ THIS
MORNING, WHERE HIGHER MOISTURE IN ASSOCIATION WITH A PASSING
SHORTWAVE TROUGH TO OUR NORTHEAST REMAINS TRAPPED BELOW THE
SUBSIDENCE INVERSION AT AROUND 900 MB. THE DELMARVA IS POSITIONED IN
THE RIGHT ENTRANCE REGION OF MID-LEVEL JET STREAK, RESULTING IN
OVERCAST MID CLOUDS IN OUR SOUTHERN ZONES. HOWEVER, THERE IS A
BAND OF CLEARING EVIDENT ON THE LATEST VISIBLE SATELLITE IMAGERY
IN THE MIDDLE PART OF THE CWA THAT IS DEVELOPING OVER SOUTHEAST
PA, INCLUDING PHILLY AND ADJACENT CENTRAL/SOUTHERN NJ MID
MORNING. THE CLEARING SHOULD EXPAND SOUTH AND EASTWARD THRUOUT THE
DAY AS THE JET STREAK PROGRESSES OFF THE COAST, ALTHOUGH THE
HEATING WILL LEAD TO DEVELOPMENT OF SCATTERED STRATOCU. CLOUDS
SHOULD BE SLOWER TO ERODE OVER NORTHEAST PA AND NORTHWEST NJ THRU
MIDDAY, BUT SOME SUN IS ANTICIPATED LATER IN THE AFTERNOON.

ONLY MADE MINOR ADJUSTMENTS TO THE MAX TEMP FORECAST BASED OFF
CHANGES MADE TO THE SKY GRIDS. MAX TEMPS RANGE FROM THE LOWER 30S IN
THE POCONOS TO AROUND 40F IN PHILLY, SOUTHERN NJ AND THE DELMARVA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE HIGH PRESSURE BEGINS TO RETREAT SOME OVERNIGHT TONIGHT, BUT
OUR AREA WILL STILL REMAIN ON THE SOUTHERN FRINGE. ANY PARTIAL
CLEARING THAT OCCURRED DURING THE DAY WILL CONTINUE INTO THE
EVENING, BUT HIGH LEVEL CLOUD COVER MAY BEGIN TO DEVELOP AND
SPREAD BACK INTO THE AREA OVERNIGHT AS A WEAK SHORT WAVE LIFTS
THROUGH THE AREA. WE ARE NOT EXPECTING ANY PRECIPITATION OVERNIGHT
AS THERE IS A LACK OF SIGNIFICANT VERTICAL MOISTURE.

LOW TEMPERATURES ARE A BLEND OF MAV/MET MOS AND MOSGUIDE WHICH
WERE ALL IN PRETTY GOOD AGREEMENT.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A MID LEVEL RIDGE AXIS SHOULD BE TO OUR EAST ON MONDAY. AN
IMPULSE TRAVELING IN THE MID LEVEL FLOW IS EXPECTED TO PASS
OVERHEAD ON MONDAY AFTERNOON. MOISTURE IS FORECAST TO SPREAD INTO
OUR REGION FROM THE SOUTH AT THAT TIME. WE HAVE MENTIONED A CHANCE
OF RAIN ARRIVING FROM SOUTH TO NORTH FROM THE LATE MORNING INTO
THE AFTERNOON HOURS. THE FORECAST TEMPERATURE PROFILES SUGGEST
THAT THE BOUNDARY LAYER WILL BE ABLE TO SUPPORT ALL RAIN EVEN UP
NORTH WHERE THE CHANCE FOR PRECIPITATION IS THE LOWEST IN OUR
REGION.

SURFACE HIGH PRESSURE IS FORECAST TO BE LOCATED OVER ATLANTIC
CANADA FROM MONDAY INTO TUESDAY. A RIDGE AXIS IS EXPECTED TO NOSE
SOUTHWESTWARD ALONG THE LEE OF THE APPALACHIANS AT THAT TIME WITH
AN INVERTED TROUGH DEVELOPING OFF THE COAST. WEAK LOW PRESSURE IS
ANTICIPATED TO DEVELOP ON THE TROUGH OFF THE CAROLINA COAST ON
MONDAY. THE FEATURE IS FORECAST TO REMAIN WEAK AS IT DRIFTS
NORTHEASTWARD REACHING THE WATERS OFF THE DELMARVA PENINSULA
BEFORE DISSIPATING ON TUESDAY.

MEANWHILE, A DEEP MID LEVEL TROUGH IS EXPECTED TO DIG OVER THE
MIDDLE PART OF THE COUNTRY ON MONDAY AND TUESDAY AS THE RIDGE OVER
THE WESTERN NORTH ATLANTIC BECOMES MORE PRONOUNCED. THE PATTERN
WILL RESULT IN THE DEVELOPMENT OF STRONG WARM ADVECTION OVER OUR
REGION FROM TUESDAY INTO TUESDAY NIGHT.

THE PATTERN SHOULD KEEP OUR REGION OVERCAST WITH A CHANCE OF RAIN
FROM MONDAY NIGHT INTO TUESDAY WITH THE PROBABILITY OF
PRECIPITATION INCREASING TO LIKELY FOR TUESDAY NIGHT. IT CONTINUES
TO APPEAR AS THOUGH THERE MAY BE POCKETS OF BELOW FREEZING
TEMPERATURES IN THE POCONOS AND IN FAR NORTHERN NEW JERSEY FROM
MONDAY NIGHT INTO TUESDAY MORNING TO POSSIBLY RESULT IN SOME
LOCALIZED LIGHT FREEZING RAIN.

SURFACE LOW PRESSURE IS ANTICIPATED TO DEVELOP AROUND THE CENTRAL
GULF COAST REGION ON TUESDAY IN RESPONSE TO THE DEEP MID LEVEL
TROUGH. THE LOW IS FORECAST TO STRENGTHEN AS IT MOVES NORTHWARD ON
WEDNESDAY AND ACROSS THE EASTERN GREAT LAKES ON WEDNESDAY NIGHT.
THE SYSTEM SHOULD HAVE AN OPPORTUNITY TO TAP INTO GULF MOISTURE
AND IT WILL BRING THE POTENTIAL FOR SOME MODERATE TO HEAVY
RAINFALL TO OUR REGION FROM LATE TUESDAY NIGHT INTO EARLY
WEDNESDAY NIGHT. THE CONSENSUS OF THE MODELS CONTINUES TO SUGGEST
REPRESENTATIVE RAINFALL AMOUNTS UP TO AN INCH TO AN INCH AND A
HALF IN OUR REGION DURING THE MID WEEK PERIOD.

THE LOW IS EXPECTED TO PULL A WARM FRONT THROUGH OUR REGION ON
WEDNESDAY WITH TEMPERATURES FORECAST TO RISE INTO THE 50S AND
LOWER 60S. A STRONG COLD FRONT IS FORECAST TO FOLLOW LATE ON
WEDNESDAY NIGHT WITH TEMPERATURES DROPPING BACK INTO THE UPPER 30S
AND LOWER 40S BY DAYBREAK ON THURSDAY. THE PROBABILITY OF
PRECIPITATION DECREASES RAPIDLY LATE ON WEDNESDAY NIGHT AS DRY AIR
IS EXPECTED TO BEGIN BUILDING INTO OUR REGION FROM THE WEST AND
SOUTHWEST. CONDITIONS ARE ANTICIPATED TO BECOME QUITE BREEZY IN
THE WAKE OF THE COLD FRONT FOR CHRISTMAS DAY. A WEST WIND AROUND
15 TO 20 MPH IS FORECAST WITH GUSTS NEAR 30 MPH. TEMPERATURES
SHOULD RETURN TO SEASONABLE LEVELS FOR THURSDAY, FRIDAY AND
SATURDAY.

RIDGING IS FORECAST TO DEVELOP AT THE SURFACE AND ALOFT FOR
THURSDAY NIGHT INTO FRIDAY WITH DRY WEATHER ANTICIPATED.

A MID LEVEL SHORT WAVE IS EXPECTED TO APPROACH FROM THE WEST
ALONG WITH AN ASSOCIATED SURFACE COLD FRONT. THE FRONT IS FORECAST
TO PASS THROUGH OUR REGION ON SATURDAY. THE SYSTEM IS FORECAST TO
BE FAST MOVING AND IT SHOULD NOT HAVE MUCH OF AN OPPORTUNITY TO
TAP INTO A MOISTURE SOURCE. AS A RESULT, WE WILL NOT FORECAST ANY
PRECIPITATION WITH THE FRONT AT THIS TIME.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

VFR TODAY. CLEARING HAS ALREADY OCCURRED ACROSS PHILLY AREA
TERMINALS THIS MORNING WHILE ABE REMAINS OVC JUST ABOVE 3000 FT.
EXPECT SCT CIGS AROUND 3 KFT THIS AFTN FOR ALL TERMINALS. WINDS
WILL BE LIGHT (BELOW 10 KT). WINDS WILL BECOME LIGHT AND
VARIABLE/CALM ONCE AGAIN TONIGHT.

OUTLOOK...
MONDAY...MAINLY VFR WITH A CHANCE OF LIGHT RAIN SPREADING
NORTHWARD INTO OUR REGION.

MONDAY NIGHT AND TUESDAY...CONDITIONS POSSIBLY LOWERING INTO THE
MVFR CATEGORY WITH A CHANCE OF LIGHT RAIN.

TUESDAY NIGHT...MVFR AND IFR CONDITIONS ANTICIPATED WITH RAIN
LIKELY.

WEDNESDAY AND WEDNESDAY NIGHT...MVFR AND IFR CONDITIONS WITH RAIN
LIKELY. THE RAIN MAY BE HEAVY AT TIMES.

THURSDAY...CONDITIONS IMPROVING TO VFR WITH A GUSTY WEST WIND.

&&

.MARINE...
SUB-SMALL CRAFT ADVISORY CONDITIONS WILL REMAIN TODAY INTO
TONIGHT AS HIGH PRESSURE FROM THE NORTH WILL CONTINUE TO AFFECT
THE WATERS.

OUTLOOK...
MONDAY AND MONDAY NIGHT...NO MARINE HEADLINES ARE ANTICIPATED.

TUESDAY AND TUESDAY NIGHT...WAVE HEIGHTS ON OUR OCEAN WATERS MAY
BUILD TO 5 FEET IN A DEVELOPING ONSHORE FLOW.

WEDNESDAY...SOUTHERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 6 TO 9
FEET.

WEDNESDAY NIGHT...A SOUTH WIND BECOMING WEST. WIND GUSTS IN
EXCESS OF 25 KNOTS ARE EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS
MAY BE TO 6 TO 9 FEET.

THURSDAY...WESTERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BE TO 5 TO 7 FEET.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...IOVINO
NEAR TERM...KLEIN
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/KLEIN/ROBERTSON
MARINE...IOVINO/ROBERTSON







000
FXUS61 KPHI 211432
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
932 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER QUEBEC EARLY THIS MORNING WILL DRIFT
EASTWARD AND IT SHOULD REACH ATLANTIC CANADA ON MONDAY. WEAK LOW
PRESSURE IS FORECAST TO DEVELOP OFF THE CAROLINA COAST ON MONDAY
BEFORE MOVING SLOWLY NORTHEASTWARD AND DISSIPATING OFF THE
DELMARVA PENINSULA ON TUESDAY. LOW PRESSURE IS EXPECTED TO DEVELOP
AROUND THE CENTRAL GULF COAST REGION ON TUESDAY. THE LOW SHOULD
STRENGTHEN AS IT LIFTS NORTHWARD AND ACROSS THE EASTERN GREAT
LAKES ON WEDNESDAY NIGHT. THE LOW IS ANTICIPATED TO PULL A WARM
FRONT THROUGH OUR REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT
LATE ON WEDNESDAY NIGHT. HIGH PRESSURE IS EXPECTED TO FOLLOW FROM
THE SOUTHWEST FOR THURSDAY AND FRIDAY. ANOTHER COLD FRONT FROM THE
WEST IS FORECAST TO ARRIVE ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE CENTER OF A 1030 MB SURFACE HIGH WAS ANALYZED OVER EASTERN
CANADA AT 14Z THIS MORNING. THIS BROAD AREA OF HIGH PRESSURE
ENCOMPASSES MOST OF THE EASTERN SEABOARD. THE PRESSURE GRADIENT
AND RESULTANT WINDS WILL BE LIGHT OVER THE MID-ATLANTIC REGION
TODAY UNDER THIS SETUP.

STRATOCU STILL HOLDING STRONG OVER NORTHEAST PA AND NORTHERN NJ THIS
MORNING, WHERE HIGHER MOISTURE IN ASSOCIATION WITH A PASSING
SHORTWAVE TROUGH TO OUR NORTHEAST REMAINS TRAPPED BELOW THE
SUBSIDENCE INVERSION AT AROUND 900 MB. THE DELMARVA IS POSITIONED IN
THE RIGHT ENTRANCE REGION OF MID-LEVEL JET STREAK, RESULTING IN
OVERCAST MID CLOUDS IN OUR SOUTHERN ZONES. HOWEVER, THERE IS A
BAND OF CLEARING EVIDENT ON THE LATEST VISIBLE SATELLITE IMAGERY
IN THE MIDDLE PART OF THE CWA THAT IS DEVELOPING OVER SOUTHEAST
PA, INCLUDING PHILLY AND ADJACENT CENTRAL/SOUTHERN NJ MID
MORNING. THE CLEARING SHOULD EXPAND SOUTH AND EASTWARD THRUOUT THE
DAY AS THE JET STREAK PROGRESSES OFF THE COAST, ALTHOUGH THE
HEATING WILL LEAD TO DEVELOPMENT OF SCATTERED STRATOCU. CLOUDS
SHOULD BE SLOWER TO ERODE OVER NORTHEAST PA AND NORTHWEST NJ THRU
MIDDAY, BUT SOME SUN IS ANTICIPATED LATER IN THE AFTERNOON.

ONLY MADE MINOR ADJUSTMENTS TO THE MAX TEMP FORECAST BASED OFF
CHANGES MADE TO THE SKY GRIDS. MAX TEMPS RANGE FROM THE LOWER 30S IN
THE POCONOS TO AROUND 40F IN PHILLY, SOUTHERN NJ AND THE DELMARVA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE HIGH PRESSURE BEGINS TO RETREAT SOME OVERNIGHT TONIGHT, BUT
OUR AREA WILL STILL REMAIN ON THE SOUTHERN FRINGE. ANY PARTIAL
CLEARING THAT OCCURRED DURING THE DAY WILL CONTINUE INTO THE
EVENING, BUT HIGH LEVEL CLOUD COVER MAY BEGIN TO DEVELOP AND
SPREAD BACK INTO THE AREA OVERNIGHT AS A WEAK SHORT WAVE LIFTS
THROUGH THE AREA. WE ARE NOT EXPECTING ANY PRECIPITATION OVERNIGHT
AS THERE IS A LACK OF SIGNIFICANT VERTICAL MOISTURE.

LOW TEMPERATURES ARE A BLEND OF MAV/MET MOS AND MOSGUIDE WHICH
WERE ALL IN PRETTY GOOD AGREEMENT.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A MID LEVEL RIDGE AXIS SHOULD BE TO OUR EAST ON MONDAY. AN
IMPULSE TRAVELING IN THE MID LEVEL FLOW IS EXPECTED TO PASS
OVERHEAD ON MONDAY AFTERNOON. MOISTURE IS FORECAST TO SPREAD INTO
OUR REGION FROM THE SOUTH AT THAT TIME. WE HAVE MENTIONED A CHANCE
OF RAIN ARRIVING FROM SOUTH TO NORTH FROM THE LATE MORNING INTO
THE AFTERNOON HOURS. THE FORECAST TEMPERATURE PROFILES SUGGEST
THAT THE BOUNDARY LAYER WILL BE ABLE TO SUPPORT ALL RAIN EVEN UP
NORTH WHERE THE CHANCE FOR PRECIPITATION IS THE LOWEST IN OUR
REGION.

SURFACE HIGH PRESSURE IS FORECAST TO BE LOCATED OVER ATLANTIC
CANADA FROM MONDAY INTO TUESDAY. A RIDGE AXIS IS EXPECTED TO NOSE
SOUTHWESTWARD ALONG THE LEE OF THE APPALACHIANS AT THAT TIME WITH
AN INVERTED TROUGH DEVELOPING OFF THE COAST. WEAK LOW PRESSURE IS
ANTICIPATED TO DEVELOP ON THE TROUGH OFF THE CAROLINA COAST ON
MONDAY. THE FEATURE IS FORECAST TO REMAIN WEAK AS IT DRIFTS
NORTHEASTWARD REACHING THE WATERS OFF THE DELMARVA PENINSULA
BEFORE DISSIPATING ON TUESDAY.

MEANWHILE, A DEEP MID LEVEL TROUGH IS EXPECTED TO DIG OVER THE
MIDDLE PART OF THE COUNTRY ON MONDAY AND TUESDAY AS THE RIDGE OVER
THE WESTERN NORTH ATLANTIC BECOMES MORE PRONOUNCED. THE PATTERN
WILL RESULT IN THE DEVELOPMENT OF STRONG WARM ADVECTION OVER OUR
REGION FROM TUESDAY INTO TUESDAY NIGHT.

THE PATTERN SHOULD KEEP OUR REGION OVERCAST WITH A CHANCE OF RAIN
FROM MONDAY NIGHT INTO TUESDAY WITH THE PROBABILITY OF
PRECIPITATION INCREASING TO LIKELY FOR TUESDAY NIGHT. IT CONTINUES
TO APPEAR AS THOUGH THERE MAY BE POCKETS OF BELOW FREEZING
TEMPERATURES IN THE POCONOS AND IN FAR NORTHERN NEW JERSEY FROM
MONDAY NIGHT INTO TUESDAY MORNING TO POSSIBLY RESULT IN SOME
LOCALIZED LIGHT FREEZING RAIN.

SURFACE LOW PRESSURE IS ANTICIPATED TO DEVELOP AROUND THE CENTRAL
GULF COAST REGION ON TUESDAY IN RESPONSE TO THE DEEP MID LEVEL
TROUGH. THE LOW IS FORECAST TO STRENGTHEN AS IT MOVES NORTHWARD ON
WEDNESDAY AND ACROSS THE EASTERN GREAT LAKES ON WEDNESDAY NIGHT.
THE SYSTEM SHOULD HAVE AN OPPORTUNITY TO TAP INTO GULF MOISTURE
AND IT WILL BRING THE POTENTIAL FOR SOME MODERATE TO HEAVY
RAINFALL TO OUR REGION FROM LATE TUESDAY NIGHT INTO EARLY
WEDNESDAY NIGHT. THE CONSENSUS OF THE MODELS CONTINUES TO SUGGEST
REPRESENTATIVE RAINFALL AMOUNTS UP TO AN INCH TO AN INCH AND A
HALF IN OUR REGION DURING THE MID WEEK PERIOD.

THE LOW IS EXPECTED TO PULL A WARM FRONT THROUGH OUR REGION ON
WEDNESDAY WITH TEMPERATURES FORECAST TO RISE INTO THE 50S AND
LOWER 60S. A STRONG COLD FRONT IS FORECAST TO FOLLOW LATE ON
WEDNESDAY NIGHT WITH TEMPERATURES DROPPING BACK INTO THE UPPER 30S
AND LOWER 40S BY DAYBREAK ON THURSDAY. THE PROBABILITY OF
PRECIPITATION DECREASES RAPIDLY LATE ON WEDNESDAY NIGHT AS DRY AIR
IS EXPECTED TO BEGIN BUILDING INTO OUR REGION FROM THE WEST AND
SOUTHWEST. CONDITIONS ARE ANTICIPATED TO BECOME QUITE BREEZY IN
THE WAKE OF THE COLD FRONT FOR CHRISTMAS DAY. A WEST WIND AROUND
15 TO 20 MPH IS FORECAST WITH GUSTS NEAR 30 MPH. TEMPERATURES
SHOULD RETURN TO SEASONABLE LEVELS FOR THURSDAY, FRIDAY AND
SATURDAY.

RIDGING IS FORECAST TO DEVELOP AT THE SURFACE AND ALOFT FOR
THURSDAY NIGHT INTO FRIDAY WITH DRY WEATHER ANTICIPATED.

A MID LEVEL SHORT WAVE IS EXPECTED TO APPROACH FROM THE WEST
ALONG WITH AN ASSOCIATED SURFACE COLD FRONT. THE FRONT IS FORECAST
TO PASS THROUGH OUR REGION ON SATURDAY. THE SYSTEM IS FORECAST TO
BE FAST MOVING AND IT SHOULD NOT HAVE MUCH OF AN OPPORTUNITY TO
TAP INTO A MOISTURE SOURCE. AS A RESULT, WE WILL NOT FORECAST ANY
PRECIPITATION WITH THE FRONT AT THIS TIME.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

VFR TODAY. CLEARING HAS ALREADY OCCURRED ACROSS PHILLY AREA
TERMINALS THIS MORNING WHILE ABE REMAINS OVC JUST ABOVE 3000 FT.
EXPECT SCT CIGS AROUND 3 KFT THIS AFTN FOR ALL TERMINALS. WINDS
WILL BE LIGHT (BELOW 10 KT). WINDS WILL BECOME LIGHT AND
VARIABLE/CALM ONCE AGAIN TONIGHT.

OUTLOOK...
MONDAY...MAINLY VFR WITH A CHANCE OF LIGHT RAIN SPREADING
NORTHWARD INTO OUR REGION.

MONDAY NIGHT AND TUESDAY...CONDITIONS POSSIBLY LOWERING INTO THE
MVFR CATEGORY WITH A CHANCE OF LIGHT RAIN.

TUESDAY NIGHT...MVFR AND IFR CONDITIONS ANTICIPATED WITH RAIN
LIKELY.

WEDNESDAY AND WEDNESDAY NIGHT...MVFR AND IFR CONDITIONS WITH RAIN
LIKELY. THE RAIN MAY BE HEAVY AT TIMES.

THURSDAY...CONDITIONS IMPROVING TO VFR WITH A GUSTY WEST WIND.

&&

.MARINE...
SUB-SMALL CRAFT ADVISORY CONDITIONS WILL REMAIN TODAY INTO
TONIGHT AS HIGH PRESSURE FROM THE NORTH WILL CONTINUE TO AFFECT
THE WATERS.

OUTLOOK...
MONDAY AND MONDAY NIGHT...NO MARINE HEADLINES ARE ANTICIPATED.

TUESDAY AND TUESDAY NIGHT...WAVE HEIGHTS ON OUR OCEAN WATERS MAY
BUILD TO 5 FEET IN A DEVELOPING ONSHORE FLOW.

WEDNESDAY...SOUTHERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 6 TO 9
FEET.

WEDNESDAY NIGHT...A SOUTH WIND BECOMING WEST. WIND GUSTS IN
EXCESS OF 25 KNOTS ARE EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS
MAY BE TO 6 TO 9 FEET.

THURSDAY...WESTERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BE TO 5 TO 7 FEET.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...IOVINO
NEAR TERM...KLEIN
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/KLEIN/ROBERTSON
MARINE...IOVINO/ROBERTSON







000
FXUS61 KPHI 211432
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
932 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER QUEBEC EARLY THIS MORNING WILL DRIFT
EASTWARD AND IT SHOULD REACH ATLANTIC CANADA ON MONDAY. WEAK LOW
PRESSURE IS FORECAST TO DEVELOP OFF THE CAROLINA COAST ON MONDAY
BEFORE MOVING SLOWLY NORTHEASTWARD AND DISSIPATING OFF THE
DELMARVA PENINSULA ON TUESDAY. LOW PRESSURE IS EXPECTED TO DEVELOP
AROUND THE CENTRAL GULF COAST REGION ON TUESDAY. THE LOW SHOULD
STRENGTHEN AS IT LIFTS NORTHWARD AND ACROSS THE EASTERN GREAT
LAKES ON WEDNESDAY NIGHT. THE LOW IS ANTICIPATED TO PULL A WARM
FRONT THROUGH OUR REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT
LATE ON WEDNESDAY NIGHT. HIGH PRESSURE IS EXPECTED TO FOLLOW FROM
THE SOUTHWEST FOR THURSDAY AND FRIDAY. ANOTHER COLD FRONT FROM THE
WEST IS FORECAST TO ARRIVE ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE CENTER OF A 1030 MB SURFACE HIGH WAS ANALYZED OVER EASTERN
CANADA AT 14Z THIS MORNING. THIS BROAD AREA OF HIGH PRESSURE
ENCOMPASSES MOST OF THE EASTERN SEABOARD. THE PRESSURE GRADIENT
AND RESULTANT WINDS WILL BE LIGHT OVER THE MID-ATLANTIC REGION
TODAY UNDER THIS SETUP.

STRATOCU STILL HOLDING STRONG OVER NORTHEAST PA AND NORTHERN NJ THIS
MORNING, WHERE HIGHER MOISTURE IN ASSOCIATION WITH A PASSING
SHORTWAVE TROUGH TO OUR NORTHEAST REMAINS TRAPPED BELOW THE
SUBSIDENCE INVERSION AT AROUND 900 MB. THE DELMARVA IS POSITIONED IN
THE RIGHT ENTRANCE REGION OF MID-LEVEL JET STREAK, RESULTING IN
OVERCAST MID CLOUDS IN OUR SOUTHERN ZONES. HOWEVER, THERE IS A
BAND OF CLEARING EVIDENT ON THE LATEST VISIBLE SATELLITE IMAGERY
IN THE MIDDLE PART OF THE CWA THAT IS DEVELOPING OVER SOUTHEAST
PA, INCLUDING PHILLY AND ADJACENT CENTRAL/SOUTHERN NJ MID
MORNING. THE CLEARING SHOULD EXPAND SOUTH AND EASTWARD THRUOUT THE
DAY AS THE JET STREAK PROGRESSES OFF THE COAST, ALTHOUGH THE
HEATING WILL LEAD TO DEVELOPMENT OF SCATTERED STRATOCU. CLOUDS
SHOULD BE SLOWER TO ERODE OVER NORTHEAST PA AND NORTHWEST NJ THRU
MIDDAY, BUT SOME SUN IS ANTICIPATED LATER IN THE AFTERNOON.

ONLY MADE MINOR ADJUSTMENTS TO THE MAX TEMP FORECAST BASED OFF
CHANGES MADE TO THE SKY GRIDS. MAX TEMPS RANGE FROM THE LOWER 30S IN
THE POCONOS TO AROUND 40F IN PHILLY, SOUTHERN NJ AND THE DELMARVA.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE HIGH PRESSURE BEGINS TO RETREAT SOME OVERNIGHT TONIGHT, BUT
OUR AREA WILL STILL REMAIN ON THE SOUTHERN FRINGE. ANY PARTIAL
CLEARING THAT OCCURRED DURING THE DAY WILL CONTINUE INTO THE
EVENING, BUT HIGH LEVEL CLOUD COVER MAY BEGIN TO DEVELOP AND
SPREAD BACK INTO THE AREA OVERNIGHT AS A WEAK SHORT WAVE LIFTS
THROUGH THE AREA. WE ARE NOT EXPECTING ANY PRECIPITATION OVERNIGHT
AS THERE IS A LACK OF SIGNIFICANT VERTICAL MOISTURE.

LOW TEMPERATURES ARE A BLEND OF MAV/MET MOS AND MOSGUIDE WHICH
WERE ALL IN PRETTY GOOD AGREEMENT.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A MID LEVEL RIDGE AXIS SHOULD BE TO OUR EAST ON MONDAY. AN
IMPULSE TRAVELING IN THE MID LEVEL FLOW IS EXPECTED TO PASS
OVERHEAD ON MONDAY AFTERNOON. MOISTURE IS FORECAST TO SPREAD INTO
OUR REGION FROM THE SOUTH AT THAT TIME. WE HAVE MENTIONED A CHANCE
OF RAIN ARRIVING FROM SOUTH TO NORTH FROM THE LATE MORNING INTO
THE AFTERNOON HOURS. THE FORECAST TEMPERATURE PROFILES SUGGEST
THAT THE BOUNDARY LAYER WILL BE ABLE TO SUPPORT ALL RAIN EVEN UP
NORTH WHERE THE CHANCE FOR PRECIPITATION IS THE LOWEST IN OUR
REGION.

SURFACE HIGH PRESSURE IS FORECAST TO BE LOCATED OVER ATLANTIC
CANADA FROM MONDAY INTO TUESDAY. A RIDGE AXIS IS EXPECTED TO NOSE
SOUTHWESTWARD ALONG THE LEE OF THE APPALACHIANS AT THAT TIME WITH
AN INVERTED TROUGH DEVELOPING OFF THE COAST. WEAK LOW PRESSURE IS
ANTICIPATED TO DEVELOP ON THE TROUGH OFF THE CAROLINA COAST ON
MONDAY. THE FEATURE IS FORECAST TO REMAIN WEAK AS IT DRIFTS
NORTHEASTWARD REACHING THE WATERS OFF THE DELMARVA PENINSULA
BEFORE DISSIPATING ON TUESDAY.

MEANWHILE, A DEEP MID LEVEL TROUGH IS EXPECTED TO DIG OVER THE
MIDDLE PART OF THE COUNTRY ON MONDAY AND TUESDAY AS THE RIDGE OVER
THE WESTERN NORTH ATLANTIC BECOMES MORE PRONOUNCED. THE PATTERN
WILL RESULT IN THE DEVELOPMENT OF STRONG WARM ADVECTION OVER OUR
REGION FROM TUESDAY INTO TUESDAY NIGHT.

THE PATTERN SHOULD KEEP OUR REGION OVERCAST WITH A CHANCE OF RAIN
FROM MONDAY NIGHT INTO TUESDAY WITH THE PROBABILITY OF
PRECIPITATION INCREASING TO LIKELY FOR TUESDAY NIGHT. IT CONTINUES
TO APPEAR AS THOUGH THERE MAY BE POCKETS OF BELOW FREEZING
TEMPERATURES IN THE POCONOS AND IN FAR NORTHERN NEW JERSEY FROM
MONDAY NIGHT INTO TUESDAY MORNING TO POSSIBLY RESULT IN SOME
LOCALIZED LIGHT FREEZING RAIN.

SURFACE LOW PRESSURE IS ANTICIPATED TO DEVELOP AROUND THE CENTRAL
GULF COAST REGION ON TUESDAY IN RESPONSE TO THE DEEP MID LEVEL
TROUGH. THE LOW IS FORECAST TO STRENGTHEN AS IT MOVES NORTHWARD ON
WEDNESDAY AND ACROSS THE EASTERN GREAT LAKES ON WEDNESDAY NIGHT.
THE SYSTEM SHOULD HAVE AN OPPORTUNITY TO TAP INTO GULF MOISTURE
AND IT WILL BRING THE POTENTIAL FOR SOME MODERATE TO HEAVY
RAINFALL TO OUR REGION FROM LATE TUESDAY NIGHT INTO EARLY
WEDNESDAY NIGHT. THE CONSENSUS OF THE MODELS CONTINUES TO SUGGEST
REPRESENTATIVE RAINFALL AMOUNTS UP TO AN INCH TO AN INCH AND A
HALF IN OUR REGION DURING THE MID WEEK PERIOD.

THE LOW IS EXPECTED TO PULL A WARM FRONT THROUGH OUR REGION ON
WEDNESDAY WITH TEMPERATURES FORECAST TO RISE INTO THE 50S AND
LOWER 60S. A STRONG COLD FRONT IS FORECAST TO FOLLOW LATE ON
WEDNESDAY NIGHT WITH TEMPERATURES DROPPING BACK INTO THE UPPER 30S
AND LOWER 40S BY DAYBREAK ON THURSDAY. THE PROBABILITY OF
PRECIPITATION DECREASES RAPIDLY LATE ON WEDNESDAY NIGHT AS DRY AIR
IS EXPECTED TO BEGIN BUILDING INTO OUR REGION FROM THE WEST AND
SOUTHWEST. CONDITIONS ARE ANTICIPATED TO BECOME QUITE BREEZY IN
THE WAKE OF THE COLD FRONT FOR CHRISTMAS DAY. A WEST WIND AROUND
15 TO 20 MPH IS FORECAST WITH GUSTS NEAR 30 MPH. TEMPERATURES
SHOULD RETURN TO SEASONABLE LEVELS FOR THURSDAY, FRIDAY AND
SATURDAY.

RIDGING IS FORECAST TO DEVELOP AT THE SURFACE AND ALOFT FOR
THURSDAY NIGHT INTO FRIDAY WITH DRY WEATHER ANTICIPATED.

A MID LEVEL SHORT WAVE IS EXPECTED TO APPROACH FROM THE WEST
ALONG WITH AN ASSOCIATED SURFACE COLD FRONT. THE FRONT IS FORECAST
TO PASS THROUGH OUR REGION ON SATURDAY. THE SYSTEM IS FORECAST TO
BE FAST MOVING AND IT SHOULD NOT HAVE MUCH OF AN OPPORTUNITY TO
TAP INTO A MOISTURE SOURCE. AS A RESULT, WE WILL NOT FORECAST ANY
PRECIPITATION WITH THE FRONT AT THIS TIME.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

VFR TODAY. CLEARING HAS ALREADY OCCURRED ACROSS PHILLY AREA
TERMINALS THIS MORNING WHILE ABE REMAINS OVC JUST ABOVE 3000 FT.
EXPECT SCT CIGS AROUND 3 KFT THIS AFTN FOR ALL TERMINALS. WINDS
WILL BE LIGHT (BELOW 10 KT). WINDS WILL BECOME LIGHT AND
VARIABLE/CALM ONCE AGAIN TONIGHT.

OUTLOOK...
MONDAY...MAINLY VFR WITH A CHANCE OF LIGHT RAIN SPREADING
NORTHWARD INTO OUR REGION.

MONDAY NIGHT AND TUESDAY...CONDITIONS POSSIBLY LOWERING INTO THE
MVFR CATEGORY WITH A CHANCE OF LIGHT RAIN.

TUESDAY NIGHT...MVFR AND IFR CONDITIONS ANTICIPATED WITH RAIN
LIKELY.

WEDNESDAY AND WEDNESDAY NIGHT...MVFR AND IFR CONDITIONS WITH RAIN
LIKELY. THE RAIN MAY BE HEAVY AT TIMES.

THURSDAY...CONDITIONS IMPROVING TO VFR WITH A GUSTY WEST WIND.

&&

.MARINE...
SUB-SMALL CRAFT ADVISORY CONDITIONS WILL REMAIN TODAY INTO
TONIGHT AS HIGH PRESSURE FROM THE NORTH WILL CONTINUE TO AFFECT
THE WATERS.

OUTLOOK...
MONDAY AND MONDAY NIGHT...NO MARINE HEADLINES ARE ANTICIPATED.

TUESDAY AND TUESDAY NIGHT...WAVE HEIGHTS ON OUR OCEAN WATERS MAY
BUILD TO 5 FEET IN A DEVELOPING ONSHORE FLOW.

WEDNESDAY...SOUTHERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 6 TO 9
FEET.

WEDNESDAY NIGHT...A SOUTH WIND BECOMING WEST. WIND GUSTS IN
EXCESS OF 25 KNOTS ARE EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS
MAY BE TO 6 TO 9 FEET.

THURSDAY...WESTERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BE TO 5 TO 7 FEET.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...IOVINO
NEAR TERM...KLEIN
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/KLEIN/ROBERTSON
MARINE...IOVINO/ROBERTSON






000
FXUS61 KPBZ 211423
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
923 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL THROUGH MONDAY. EXPECT
INCREASING PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN
AND WIND CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES NEEDED TO THE FORECAST FOR TODAY. A FEW BREAKS IN
THE STRATUS DECK ARE EVIDENT IN THE SAT LOOP. CLOUD DECK IS FAIRLY
SHALLOW...EVIDENCED BY VERY DRY AIR ABOVE H700 ON SOUNDING. NEW
NAM RUN SEEMS TO HAVE A GOOD HANDLE ON H850 MOISTURE
CURRENTLY...AND DRIER AIR AT THAT LEVEL IN OHIO IS SET TO ARRIVE
THIS AFTERNOON ON LIGHT W FLOW. THUS...STILL EXPECT A DECREASING
TREND IN CLOUD COVER WITH TIME. TEMPERATURES ON TRACK FOR HIGHS IN
THE LOWER TO MID 30S.


&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
SURFACE HIGH WILL SLIDE EASTWARD TONIGHT...AS WILL THE UPPER LEVEL
RIDGE. WAA WILL GET STARTED MONDAY MORNING AND CONTINUE THROUGHOUT
THE DAY. THE WARMER AIR WILL ALSO PULL MOISTURE NORTHWARD...
INCREASING CLOUDS ONCE AGAIN. BIG QUESTION ON MONDAY IS THE OUTER
EDGE OF THE PRECIP SHIELD THAT IS ASSOCIATED WITH EASTERN SEABOARD
SYSTEM. IT APPEARS THAT SOME OF THIS PRECIP COULD CLIP THE
SOUTHEASTERN RIDGES ON MONDAY. THE PROBLEM WILL BE THE COLD AIR
TRAPPED IN THE RIDGES...THANKS TO THE LOW-LEVEL EASTERLY FLOW.
CONFIDENCE IS LOW HERE...AS MODELS HAVE BOUNCED BACK AND FORTH
WITH HOW FAR WEST TO SPREAD THE PRECIP. THERE IS VERY LITTLE UPPER
LEVEL SUPPORT THIS FAR WEST...BUT WITH THE EASTERLY FLOW...
SHOWERS MAY BE ABLE TO CLIP THE AFOREMENTIONED RIDGES. SURFACE
TEMPS WILL BE CRITICAL...BUT IT DOES APPEAR THAT AT LEAST THE
SHELTERED VALLEYS WILL BE ABLE TO HOLD ON TO TEMPS AT OR BELOW
FREEZING. WILL NEED TO INCLUDE THE MENTION OF FREEZING RAIN IN
THESE AREAS MONDAY.

LOW-LEVEL JET WILL GET STRONG WAA GOING MONDAY NIGHT AND TUESDAY.
STILL TOUGH TO GET A GOOD HANDLE ON HOW MUCH RAIN WILL REACH THE
REGION ON TUESDAY. THE UPPER LEVEL SUPPORT IS WEAK AND
UNORGANIZED...BUT THE LOW-LEVEL JET WILL PULL MOISTURE NORTHWARD
AS WELL. WILL INCREASE RAIN CHANCES FROM WEST TO EAST TUESDAY...BUT
KEEP EVERYTHING IN THE CHANCE CATEGORY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED...GIVEN
THE TIME PERIOD WHICH IT AFFECTS OUR AREA...IS STILL ON TRACK.
LONG RANGE ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE
CONVERGING ON A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.
THIS WILL MAKE FOR ALL LIQUID PRECIPITATION ON THE FRONT END.
TEMPERATURES WILL SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY
WITH 50S COMMON. COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF
MEXICO...SOUNDINGS ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES
TEMP DIFFERENTIAL BETWEEN H8 AND H5 TO NEARLY 0C. THIS COULD LEAD
TO ISOLATED THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE. FOR THE
TIME BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT
FOR BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT. DESPITE
PWATS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT. LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE
PROJECTED QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY. FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST. HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE
GROUND AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME. ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER. EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE. NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS. MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
SPOTTY MVFR CIG RESTRICTIONS WILL IMPROVE THIS MORNING AS WINDS
ALOFT TRANSITION TO THE SOUTHWEST AHEAD OF A LOW PRESSURE SYSTEM
DEVELOPING OVER THE CENTRAL CONUS.

OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$






000
FXUS61 KPBZ 211423
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
923 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL THROUGH MONDAY. EXPECT
INCREASING PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN
AND WIND CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO MAJOR CHANGES NEEDED TO THE FORECAST FOR TODAY. A FEW BREAKS IN
THE STRATUS DECK ARE EVIDENT IN THE SAT LOOP. CLOUD DECK IS FAIRLY
SHALLOW...EVIDENCED BY VERY DRY AIR ABOVE H700 ON SOUNDING. NEW
NAM RUN SEEMS TO HAVE A GOOD HANDLE ON H850 MOISTURE
CURRENTLY...AND DRIER AIR AT THAT LEVEL IN OHIO IS SET TO ARRIVE
THIS AFTERNOON ON LIGHT W FLOW. THUS...STILL EXPECT A DECREASING
TREND IN CLOUD COVER WITH TIME. TEMPERATURES ON TRACK FOR HIGHS IN
THE LOWER TO MID 30S.


&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
SURFACE HIGH WILL SLIDE EASTWARD TONIGHT...AS WILL THE UPPER LEVEL
RIDGE. WAA WILL GET STARTED MONDAY MORNING AND CONTINUE THROUGHOUT
THE DAY. THE WARMER AIR WILL ALSO PULL MOISTURE NORTHWARD...
INCREASING CLOUDS ONCE AGAIN. BIG QUESTION ON MONDAY IS THE OUTER
EDGE OF THE PRECIP SHIELD THAT IS ASSOCIATED WITH EASTERN SEABOARD
SYSTEM. IT APPEARS THAT SOME OF THIS PRECIP COULD CLIP THE
SOUTHEASTERN RIDGES ON MONDAY. THE PROBLEM WILL BE THE COLD AIR
TRAPPED IN THE RIDGES...THANKS TO THE LOW-LEVEL EASTERLY FLOW.
CONFIDENCE IS LOW HERE...AS MODELS HAVE BOUNCED BACK AND FORTH
WITH HOW FAR WEST TO SPREAD THE PRECIP. THERE IS VERY LITTLE UPPER
LEVEL SUPPORT THIS FAR WEST...BUT WITH THE EASTERLY FLOW...
SHOWERS MAY BE ABLE TO CLIP THE AFOREMENTIONED RIDGES. SURFACE
TEMPS WILL BE CRITICAL...BUT IT DOES APPEAR THAT AT LEAST THE
SHELTERED VALLEYS WILL BE ABLE TO HOLD ON TO TEMPS AT OR BELOW
FREEZING. WILL NEED TO INCLUDE THE MENTION OF FREEZING RAIN IN
THESE AREAS MONDAY.

LOW-LEVEL JET WILL GET STRONG WAA GOING MONDAY NIGHT AND TUESDAY.
STILL TOUGH TO GET A GOOD HANDLE ON HOW MUCH RAIN WILL REACH THE
REGION ON TUESDAY. THE UPPER LEVEL SUPPORT IS WEAK AND
UNORGANIZED...BUT THE LOW-LEVEL JET WILL PULL MOISTURE NORTHWARD
AS WELL. WILL INCREASE RAIN CHANCES FROM WEST TO EAST TUESDAY...BUT
KEEP EVERYTHING IN THE CHANCE CATEGORY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED...GIVEN
THE TIME PERIOD WHICH IT AFFECTS OUR AREA...IS STILL ON TRACK.
LONG RANGE ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE
CONVERGING ON A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.
THIS WILL MAKE FOR ALL LIQUID PRECIPITATION ON THE FRONT END.
TEMPERATURES WILL SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY
WITH 50S COMMON. COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF
MEXICO...SOUNDINGS ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES
TEMP DIFFERENTIAL BETWEEN H8 AND H5 TO NEARLY 0C. THIS COULD LEAD
TO ISOLATED THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE. FOR THE
TIME BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT
FOR BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT. DESPITE
PWATS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT. LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE
PROJECTED QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY. FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST. HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE
GROUND AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME. ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER. EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE. NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS. MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
SPOTTY MVFR CIG RESTRICTIONS WILL IMPROVE THIS MORNING AS WINDS
ALOFT TRANSITION TO THE SOUTHWEST AHEAD OF A LOW PRESSURE SYSTEM
DEVELOPING OVER THE CENTRAL CONUS.

OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$







000
FXUS61 KPBZ 211147
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
647 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL THROUGH MONDAY. EXPECT
INCREASING PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN
AND WIND CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO UPDATES NEEDED EARLY THIS MORNING AS THE FORECAST REMAINS RIGHT
ON TRACK. PREV DISCUSSION FOLLOWS..

WEAK RIDGING ALOFT AND HIGH PRESSURE AT THE SURFACE WILL KEEP THE
REGION DRY TODAY. CLOUD COVER AGAIN WILL BE TRICKY. DRIER AIR...IN
THE STRATOCU LAYER...WILL SLOWLY MOVE NORTH AND EAST TODAY WITH
THE 850MB RIDGE. WILL CONTINUE WITH THE IDEA OF DECREASING
CLOUDS... JUST NOT CONFIDENT ON HOW FAR EAST THE DRY AIR WILL
PUSH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
SURFACE HIGH WILL SLIDE EASTWARD TONIGHT...AS WILL THE UPPER LEVEL
RIDGE. WAA WILL GET STARTED MONDAY MORNING AND CONTINUE THROUGHOUT
THE DAY. THE WARMER AIR WILL ALSO PULL MOISTURE NORTHWARD...
INCREASING CLOUDS ONCE AGAIN. BIG QUESTION ON MONDAY IS THE OUTER
EDGE OF THE PRECIP SHIELD THAT IS ASSOCIATED WITH EASTERN SEABOARD
SYSTEM. IT APPEARS THAT SOME OF THIS PRECIP COULD CLIP THE
SOUTHEASTERN RIDGES ON MONDAY. THE PROBLEM WILL BE THE COLD AIR
TRAPPED IN THE RIDGES...THANKS TO THE LOW-LEVEL EASTERLY FLOW.
CONFIDENCE IS LOW HERE...AS MODELS HAVE BOUNCED BACK AND FORTH
WITH HOW FAR WEST TO SPREAD THE PRECIP. THERE IS VERY LITTLE UPPER
LEVEL SUPPORT THIS FAR WEST...BUT WITH THE EASTERLY FLOW...
SHOWERS MAY BE ABLE TO CLIP THE AFOREMENTIONED RIDGES. SURFACE
TEMPS WILL BE CRITICAL...BUT IT DOES APPEAR THAT AT LEAST THE
SHELTERED VALLEYS WILL BE ABLE TO HOLD ON TO TEMPS AT OR BELOW
FREEZING. WILL NEED TO INCLUDE THE MENTION OF FREEZING RAIN IN
THESE AREAS MONDAY.

LOW-LEVEL JET WILL GET STRONG WAA GOING MONDAY NIGHT AND TUESDAY.
STILL TOUGH TO GET A GOOD HANDLE ON HOW MUCH RAIN WILL REACH THE
REGION ON TUESDAY. THE UPPER LEVEL SUPPORT IS WEAK AND
UNORGANIZED...BUT THE LOW-LEVEL JET WILL PULL MOISTURE NORTHWARD
AS WELL. WILL INCREASE RAIN CHANCES FROM WEST TO EAST TUESDAY...BUT
KEEP EVERYTHING IN THE CHANCE CATEGORY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED...GIVEN
THE TIME PERIOD WHICH IT AFFECTS OUR AREA...IS STILL ON TRACK.
LONG RANGE ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE
CONVERGING ON A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.
THIS WILL MAKE FOR ALL LIQUID PRECIPITATION ON THE FRONT END.
TEMPERATURES WILL SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY
WITH 50S COMMON. COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF
MEXICO...SOUNDINGS ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES
TEMP DIFFERENTIAL BETWEEN H8 AND H5 TO NEARLY 0C. THIS COULD LEAD
TO ISOLATED THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE. FOR THE
TIME BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT
FOR BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT. DESPITE
PWATS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT. LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE
PROJECTED QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY. FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST. HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE
GROUND AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME. ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER. EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE. NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS. MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
SPOTTY MVFR CIG RESTRICTIONS WILL IMPROVE THIS MORNING AS WINDS
ALOFT TRANSITION TO THE SOUTHWEST AHEAD OF A LOW PRESSURE SYSTEM
DEVELOPING OVER THE CENTRAL CONUS.

OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$







000
FXUS61 KPBZ 211147
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
647 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL THROUGH MONDAY. EXPECT
INCREASING PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN
AND WIND CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO UPDATES NEEDED EARLY THIS MORNING AS THE FORECAST REMAINS RIGHT
ON TRACK. PREV DISCUSSION FOLLOWS..

WEAK RIDGING ALOFT AND HIGH PRESSURE AT THE SURFACE WILL KEEP THE
REGION DRY TODAY. CLOUD COVER AGAIN WILL BE TRICKY. DRIER AIR...IN
THE STRATOCU LAYER...WILL SLOWLY MOVE NORTH AND EAST TODAY WITH
THE 850MB RIDGE. WILL CONTINUE WITH THE IDEA OF DECREASING
CLOUDS... JUST NOT CONFIDENT ON HOW FAR EAST THE DRY AIR WILL
PUSH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
SURFACE HIGH WILL SLIDE EASTWARD TONIGHT...AS WILL THE UPPER LEVEL
RIDGE. WAA WILL GET STARTED MONDAY MORNING AND CONTINUE THROUGHOUT
THE DAY. THE WARMER AIR WILL ALSO PULL MOISTURE NORTHWARD...
INCREASING CLOUDS ONCE AGAIN. BIG QUESTION ON MONDAY IS THE OUTER
EDGE OF THE PRECIP SHIELD THAT IS ASSOCIATED WITH EASTERN SEABOARD
SYSTEM. IT APPEARS THAT SOME OF THIS PRECIP COULD CLIP THE
SOUTHEASTERN RIDGES ON MONDAY. THE PROBLEM WILL BE THE COLD AIR
TRAPPED IN THE RIDGES...THANKS TO THE LOW-LEVEL EASTERLY FLOW.
CONFIDENCE IS LOW HERE...AS MODELS HAVE BOUNCED BACK AND FORTH
WITH HOW FAR WEST TO SPREAD THE PRECIP. THERE IS VERY LITTLE UPPER
LEVEL SUPPORT THIS FAR WEST...BUT WITH THE EASTERLY FLOW...
SHOWERS MAY BE ABLE TO CLIP THE AFOREMENTIONED RIDGES. SURFACE
TEMPS WILL BE CRITICAL...BUT IT DOES APPEAR THAT AT LEAST THE
SHELTERED VALLEYS WILL BE ABLE TO HOLD ON TO TEMPS AT OR BELOW
FREEZING. WILL NEED TO INCLUDE THE MENTION OF FREEZING RAIN IN
THESE AREAS MONDAY.

LOW-LEVEL JET WILL GET STRONG WAA GOING MONDAY NIGHT AND TUESDAY.
STILL TOUGH TO GET A GOOD HANDLE ON HOW MUCH RAIN WILL REACH THE
REGION ON TUESDAY. THE UPPER LEVEL SUPPORT IS WEAK AND
UNORGANIZED...BUT THE LOW-LEVEL JET WILL PULL MOISTURE NORTHWARD
AS WELL. WILL INCREASE RAIN CHANCES FROM WEST TO EAST TUESDAY...BUT
KEEP EVERYTHING IN THE CHANCE CATEGORY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED...GIVEN
THE TIME PERIOD WHICH IT AFFECTS OUR AREA...IS STILL ON TRACK.
LONG RANGE ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE
CONVERGING ON A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.
THIS WILL MAKE FOR ALL LIQUID PRECIPITATION ON THE FRONT END.
TEMPERATURES WILL SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY
WITH 50S COMMON. COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF
MEXICO...SOUNDINGS ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES
TEMP DIFFERENTIAL BETWEEN H8 AND H5 TO NEARLY 0C. THIS COULD LEAD
TO ISOLATED THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE. FOR THE
TIME BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT
FOR BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT. DESPITE
PWATS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT. LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE
PROJECTED QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY. FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST. HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE
GROUND AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME. ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER. EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE. NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS. MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
SPOTTY MVFR CIG RESTRICTIONS WILL IMPROVE THIS MORNING AS WINDS
ALOFT TRANSITION TO THE SOUTHWEST AHEAD OF A LOW PRESSURE SYSTEM
DEVELOPING OVER THE CENTRAL CONUS.

OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$






000
FXUS61 KAKQ 211127
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
627 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY...THEN OFF THE COAST TONIGHT.
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG
THE CAROLINA COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS
THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY WITH A SFC TROF LCTD ACROSS
THE SRN APPALACHIANS. PLNTY OF MID/HIGH LVL MSTR SEEN ON TSCTNS FOR
THE DAY TO START OUT MSTLY CLDY TO CLDY. CLOUDS THIN OUT A BIT THIS
AFTRN...SPCLLY NRN HALF OF FA. ANTHR BLO NRML DAY AS CLOUDS HOLD TMPS
IN THE L-M40S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
DRY THIS EVENING. CLOUDS QUICKLY THICKEN S-N LATE EVE AND ERLY
MORNING IN RESPONSE TO LOW PRS MOVG NE FROM GOM. TRICKY PART OF FCST
WILL BE HOW FAST PCPN OVERSPREADS THE FA AND WHAT FORM P-TYPE WILL
BE OVR THE PIEDMONT AS IN-SITU WEDGE DVLPS. DESPITE SOME TIMING
DIFFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS THE
AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN E OF
I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A NARROW
LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE PIEDMONT.
THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF I95 AND N OF
RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS NEAR FREEZING.
MAY EVEN SEE SOME WET SNOWFLAKES OVER CNTYS NW OF RIC...BUT NOT
SGNFCNT ENUF TO MENTION IN FCST ATTM. QPF LOOKS MINIMAL THRU
12Z...SO ABT THE ONLY ACTION NEEDED AT THIS POINT IS A MENTION IN
HWO. RAIN SRN CNTYS. MIN TMPS MAY LIKELY OCCUR IN THE EVENING WITH
STDY READINGS AFTR MIDNITE. LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN MON MORNING AS HIGH PRS MOVES INTO ERN CANADA.
THE NRMLLY COLDER CNTYS WILL LIKELY STAY NEAR 32 DEGREES THRU 15Z
OR SO AS THE PCPN OVERPSREADS THE ENTIRE FA. EXPECT A QUICK TRANSITION
OVER TO ALL RAIN MOST AREAS JUST AFTR 12Z XPCT FOR LOUISA/FLUVANNA/
WRN GOOCHLAND/NRN CUMBERLAND CNTYS WHERE A PERIOD OF MIXED SLEET/FZ
RAIN SHUD CONT THRU 15Z BEFORE TMPS INCH ABV 32. THESE ARE THE AREAS
WHERE AN ADVSRY MAY BE NEEDED MON MORNING FOR MINIMAL IMPACT AS TMPS
HOVER ARND 32. AREAS FROM CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST
TO DORCHESTER/WICOMICO MD MAY START OFF AS A RAIN/SLEET MIX AT THEN
QUICKLY GO OVR TO RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTRN AS THE
BULK OF LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT...40-45 EAST TOWARD THE ERN
SHORE & SERN CHES BAY... M40S-L50S SERN VA/NC.

LOW PRESSURE PROGGED TO LIFT NE ALONG THE CAROLINA COAST MONDAY NIGHT
WITH STDYST PCPN ENDING SW-NE BY 06Z. SNDGS INDCTG ENUF MSTR FOR LGT
RAIN / DRIZZLE THRU THE OVRNITE HRS. TMPS STDY IN THE M30S NW TO M40S
SE. QPF 1/4 TO 1/2 IN.

MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION TUESDAY. HOWEVER...
MOIST EASTERLY FLOW WILL PREVAIL. KEPT LOW CHC (30%) POPS THRU THE
DAY ALTHROUGH SOME DRIZZLE MAY LINGER THROUGH THE MORNING HRS. BIG
TMP DIFFERENCES SEEN IN MOS DATA WHERE NAM IS SOME 5-10 DEGREES
COLDER THAN THE GFS. GIVEN MODELS MAINTAIN AN ERLY SFC FLOW...WILL
SPLIT THE DIFFERENCE FOR NOW AND GO WITH HIGHS FROM THE M-U40S OVR
THE PIEDMONT TO M-U50S CSTL AREAS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS AND LIGHT WINDS EXPECTED TO CONTINUE THROUGH THE
12Z TAF PERIOD. BKN-OVC CLOUDS AROUND 7K FT WILL SLOWLY ERODE
THROUGH LATE MORNING/EARLY AFTN. NEXT BATCH OF PCPN WILL BEGIN TO
ARRIVE FROM SOUTH TO NORTH EARLY MON MORNING.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
N-NE WINDS AOB 10 KT WILL PREVAIL TODAY WITH HIGH PRESSURE IN PLACE.
WINDS TURN MORE EASTERLY TONIGHT AND INCREASE TO 10-15 KT MOST AREAS
AS LOW PRESSURE ORGANIZING OFF THE SOUTHEAST COAST SLOWLY PUSHES
NORTH. THE SFC LOW CONTINUES TO MOVE NORTHEAST OF THE NC COAST ON
MONDAY...BUT WEAKENS BY LATE MONDAY/MONDAY NIGHT. WINDS WILL GENERALLY
REMAIN E-NE AOB 15 KT ALL WATERS DURING THIS TIME...BUT TENDING TO
BECOME MORE NORTHERLY AOB 10 KT BY EARLY TUES MORNING. LATEST
GUIDANCE INDICATES POTENTIAL FOR SEAS TO BUILD TO AROUND 5 FT OUT 20
NM LATE MON/MON EVE ACROSS THE SOUTHERN COASTAL WATERS. CONFIDENCE
NOT HIGH ENOUGH TO ISSUE A 3RD PERIOD SCA ATTM.

LIGHT NW WINDS EXPECTED TUES AS HIGH PRESSURE REMAINS IN PLACE OVER
THE MID-ATLANTIC...AND THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE DEEP SOUTH. WINDS TURN E-SE TUESDAY NIGHT AND GRADUALLY BEGIN TO
INCREASE AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. A STRONG
COLD FRONT APPROACHES THE WATERS FROM THE WEST ON WEDNESDAY WITH
WINDS BECOMING SOUTHERLY AND INCREASING TO SCA THRESHOLDS (SAVE THE
RIVERS). THE FRONT QUICKLY SWEEPS THROUGH THE AREA WED NIGHT AND
OFFSHORE EARLY THURSDAY. WINDS REMAIN ABOVE SCA LEVELS THRU LATE
THURSDAY WHILE BECOMING SW THEN W. HIGH PRESSURE RETURNS THU NIGHT
INTO THE START OF NEXT WEEKEND FOR IMPROVED CONDITIONS. SEAS WILL
GENERALLY BUILD TO 5-7 FT ON WED BEFORE SUBSIDING AGAIN LATE THU.
WAVES WILL REACH 4 FT ON THE CHES BAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...MPR
LONG TERM...BMD
AVIATION...JDM
MARINE...JDM






000
FXUS61 KAKQ 211127
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
627 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY...THEN OFF THE COAST TONIGHT.
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG
THE CAROLINA COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS
THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY WITH A SFC TROF LCTD ACROSS
THE SRN APPALACHIANS. PLNTY OF MID/HIGH LVL MSTR SEEN ON TSCTNS FOR
THE DAY TO START OUT MSTLY CLDY TO CLDY. CLOUDS THIN OUT A BIT THIS
AFTRN...SPCLLY NRN HALF OF FA. ANTHR BLO NRML DAY AS CLOUDS HOLD TMPS
IN THE L-M40S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
DRY THIS EVENING. CLOUDS QUICKLY THICKEN S-N LATE EVE AND ERLY
MORNING IN RESPONSE TO LOW PRS MOVG NE FROM GOM. TRICKY PART OF FCST
WILL BE HOW FAST PCPN OVERSPREADS THE FA AND WHAT FORM P-TYPE WILL
BE OVR THE PIEDMONT AS IN-SITU WEDGE DVLPS. DESPITE SOME TIMING
DIFFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS THE
AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN E OF
I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A NARROW
LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE PIEDMONT.
THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF I95 AND N OF
RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS NEAR FREEZING.
MAY EVEN SEE SOME WET SNOWFLAKES OVER CNTYS NW OF RIC...BUT NOT
SGNFCNT ENUF TO MENTION IN FCST ATTM. QPF LOOKS MINIMAL THRU
12Z...SO ABT THE ONLY ACTION NEEDED AT THIS POINT IS A MENTION IN
HWO. RAIN SRN CNTYS. MIN TMPS MAY LIKELY OCCUR IN THE EVENING WITH
STDY READINGS AFTR MIDNITE. LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN MON MORNING AS HIGH PRS MOVES INTO ERN CANADA.
THE NRMLLY COLDER CNTYS WILL LIKELY STAY NEAR 32 DEGREES THRU 15Z
OR SO AS THE PCPN OVERPSREADS THE ENTIRE FA. EXPECT A QUICK TRANSITION
OVER TO ALL RAIN MOST AREAS JUST AFTR 12Z XPCT FOR LOUISA/FLUVANNA/
WRN GOOCHLAND/NRN CUMBERLAND CNTYS WHERE A PERIOD OF MIXED SLEET/FZ
RAIN SHUD CONT THRU 15Z BEFORE TMPS INCH ABV 32. THESE ARE THE AREAS
WHERE AN ADVSRY MAY BE NEEDED MON MORNING FOR MINIMAL IMPACT AS TMPS
HOVER ARND 32. AREAS FROM CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST
TO DORCHESTER/WICOMICO MD MAY START OFF AS A RAIN/SLEET MIX AT THEN
QUICKLY GO OVR TO RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTRN AS THE
BULK OF LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT...40-45 EAST TOWARD THE ERN
SHORE & SERN CHES BAY... M40S-L50S SERN VA/NC.

LOW PRESSURE PROGGED TO LIFT NE ALONG THE CAROLINA COAST MONDAY NIGHT
WITH STDYST PCPN ENDING SW-NE BY 06Z. SNDGS INDCTG ENUF MSTR FOR LGT
RAIN / DRIZZLE THRU THE OVRNITE HRS. TMPS STDY IN THE M30S NW TO M40S
SE. QPF 1/4 TO 1/2 IN.

MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION TUESDAY. HOWEVER...
MOIST EASTERLY FLOW WILL PREVAIL. KEPT LOW CHC (30%) POPS THRU THE
DAY ALTHROUGH SOME DRIZZLE MAY LINGER THROUGH THE MORNING HRS. BIG
TMP DIFFERENCES SEEN IN MOS DATA WHERE NAM IS SOME 5-10 DEGREES
COLDER THAN THE GFS. GIVEN MODELS MAINTAIN AN ERLY SFC FLOW...WILL
SPLIT THE DIFFERENCE FOR NOW AND GO WITH HIGHS FROM THE M-U40S OVR
THE PIEDMONT TO M-U50S CSTL AREAS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS AND LIGHT WINDS EXPECTED TO CONTINUE THROUGH THE
12Z TAF PERIOD. BKN-OVC CLOUDS AROUND 7K FT WILL SLOWLY ERODE
THROUGH LATE MORNING/EARLY AFTN. NEXT BATCH OF PCPN WILL BEGIN TO
ARRIVE FROM SOUTH TO NORTH EARLY MON MORNING.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
N-NE WINDS AOB 10 KT WILL PREVAIL TODAY WITH HIGH PRESSURE IN PLACE.
WINDS TURN MORE EASTERLY TONIGHT AND INCREASE TO 10-15 KT MOST AREAS
AS LOW PRESSURE ORGANIZING OFF THE SOUTHEAST COAST SLOWLY PUSHES
NORTH. THE SFC LOW CONTINUES TO MOVE NORTHEAST OF THE NC COAST ON
MONDAY...BUT WEAKENS BY LATE MONDAY/MONDAY NIGHT. WINDS WILL GENERALLY
REMAIN E-NE AOB 15 KT ALL WATERS DURING THIS TIME...BUT TENDING TO
BECOME MORE NORTHERLY AOB 10 KT BY EARLY TUES MORNING. LATEST
GUIDANCE INDICATES POTENTIAL FOR SEAS TO BUILD TO AROUND 5 FT OUT 20
NM LATE MON/MON EVE ACROSS THE SOUTHERN COASTAL WATERS. CONFIDENCE
NOT HIGH ENOUGH TO ISSUE A 3RD PERIOD SCA ATTM.

LIGHT NW WINDS EXPECTED TUES AS HIGH PRESSURE REMAINS IN PLACE OVER
THE MID-ATLANTIC...AND THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE DEEP SOUTH. WINDS TURN E-SE TUESDAY NIGHT AND GRADUALLY BEGIN TO
INCREASE AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. A STRONG
COLD FRONT APPROACHES THE WATERS FROM THE WEST ON WEDNESDAY WITH
WINDS BECOMING SOUTHERLY AND INCREASING TO SCA THRESHOLDS (SAVE THE
RIVERS). THE FRONT QUICKLY SWEEPS THROUGH THE AREA WED NIGHT AND
OFFSHORE EARLY THURSDAY. WINDS REMAIN ABOVE SCA LEVELS THRU LATE
THURSDAY WHILE BECOMING SW THEN W. HIGH PRESSURE RETURNS THU NIGHT
INTO THE START OF NEXT WEEKEND FOR IMPROVED CONDITIONS. SEAS WILL
GENERALLY BUILD TO 5-7 FT ON WED BEFORE SUBSIDING AGAIN LATE THU.
WAVES WILL REACH 4 FT ON THE CHES BAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...MPR
LONG TERM...BMD
AVIATION...JDM
MARINE...JDM







000
FXUS61 KPBZ 210915
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
415 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL THROUGH MONDAY. EXPECT
INCREASING PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN
AND WIND CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK RIDGING ALOFT AND HIGH PRESSURE AT THE SURFACE WILL KEEP THE
REGION DRY TODAY. CLOUD COVER AGAIN WILL BE TRICKY. DRIER AIR...IN
THE STRATOCU LAYER...WILL SLOWLY MOVE NORTH AND EAST TODAY WITH
THE 850MB RIDGE. WILL CONTINUE WITH THE IDEA OF DECREASING CLOUDS...
JUST NOT CONFIDENT ON HOW FAR EAST THE DRY AIR WILL PUSH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
SURFACE HIGH WILL SLIDE EASTWARD TONIGHT...AS WILL THE UPPER LEVEL
RIDGE. WAA WILL GET STARTED MONDAY MORNING AND CONTINUE THROUGHOUT
THE DAY. THE WARMER AIR WILL ALSO PULL MOISTURE NORTHWARD...
INCREASING CLOUDS ONCE AGAIN. BIG QUESTION ON MONDAY IS THE OUTER
EDGE OF THE PRECIP SHIELD THAT IS ASSOCIATED WITH EASTERN SEABOARD
SYSTEM. IT APPEARS THAT SOME OF THIS PRECIP COULD CLIP THE
SOUTHEASTERN RIDGES ON MONDAY. THE PROBLEM WILL BE THE COLD AIR
TRAPPED IN THE RIDGES...THANKS TO THE LOW-LEVEL EASTERLY FLOW.
CONFIDENCE IS LOW HERE...AS MODELS HAVE BOUNCED BACK AND FORTH
WITH HOW FAR WEST TO SPREAD THE PRECIP. THERE IS VERY LITTLE UPPER
LEVEL SUPPORT THIS FAR WEST...BUT WITH THE EASTERLY FLOW...
SHOWERS MAY BE ABLE TO CLIP THE AFOREMENTIONED RIDGES. SURFACE
TEMPS WILL BE CRITICAL...BUT IT DOES APPEAR THAT AT LEAST THE
SHELTERED VALLEYS WILL BE ABLE TO HOLD ON TO TEMPS AT OR BELOW
FREEZING. WILL NEED TO INCLUDE THE MENTION OF FREEZING RAIN IN
THESE AREAS MONDAY.

LOW-LEVEL JET WILL GET STRONG WAA GOING MONDAY NIGHT AND TUESDAY.
STILL TOUGH TO GET A GOOD HANDLE ON HOW MUCH RAIN WILL REACH THE
REGION ON TUESDAY. THE UPPER LEVEL SUPPORT IS WEAK AND
UNORGANIZED...BUT THE LOW-LEVEL JET WILL PULL MOISTURE NORTHWARD
AS WELL. WILL INCREASE RAIN CHANCES FROM WEST TO EAST TUESDAY...BUT
KEEP EVERYTHING IN THE CHANCE CATEGORY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED...GIVEN
THE TIME PERIOD WHICH IT AFFECTS OUR AREA...IS STILL ON TRACK.
LONG RANGE ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE
CONVERGING ON A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.
THIS WILL MAKE FOR ALL LIQUID PRECIPITATION ON THE FRONT END.
TEMPERATURES WILL SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY
WITH 50S COMMON. COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF
MEXICO...SOUNDINGS ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES
TEMP DIFFERENTIAL BETWEEN H8 AND H5 TO NEARLY 0C. THIS COULD LEAD
TO ISOLATED THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE. FOR THE
TIME BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT
FOR BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT. DESPITE
PWATS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT. LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE
PROJECTED QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY. FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST. HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE
GROUND AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME. ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER. EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE. NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS. MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
MVFR CONDITIONS TO CONTINUE BEFORE LOWER LEVEL CLOUDS BEGIN TO
SCATTER OUT LATE THIS MORNING AS WINDS TRANSITION TO THE SOUTHWEST
AHEAD OF A LOW PRESSURE SYSTEM DEVELOPING OVER THE CENTRAL CONUS.

OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$






000
FXUS61 KPBZ 210915
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
415 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL THROUGH MONDAY. EXPECT
INCREASING PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN
AND WIND CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK RIDGING ALOFT AND HIGH PRESSURE AT THE SURFACE WILL KEEP THE
REGION DRY TODAY. CLOUD COVER AGAIN WILL BE TRICKY. DRIER AIR...IN
THE STRATOCU LAYER...WILL SLOWLY MOVE NORTH AND EAST TODAY WITH
THE 850MB RIDGE. WILL CONTINUE WITH THE IDEA OF DECREASING CLOUDS...
JUST NOT CONFIDENT ON HOW FAR EAST THE DRY AIR WILL PUSH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
SURFACE HIGH WILL SLIDE EASTWARD TONIGHT...AS WILL THE UPPER LEVEL
RIDGE. WAA WILL GET STARTED MONDAY MORNING AND CONTINUE THROUGHOUT
THE DAY. THE WARMER AIR WILL ALSO PULL MOISTURE NORTHWARD...
INCREASING CLOUDS ONCE AGAIN. BIG QUESTION ON MONDAY IS THE OUTER
EDGE OF THE PRECIP SHIELD THAT IS ASSOCIATED WITH EASTERN SEABOARD
SYSTEM. IT APPEARS THAT SOME OF THIS PRECIP COULD CLIP THE
SOUTHEASTERN RIDGES ON MONDAY. THE PROBLEM WILL BE THE COLD AIR
TRAPPED IN THE RIDGES...THANKS TO THE LOW-LEVEL EASTERLY FLOW.
CONFIDENCE IS LOW HERE...AS MODELS HAVE BOUNCED BACK AND FORTH
WITH HOW FAR WEST TO SPREAD THE PRECIP. THERE IS VERY LITTLE UPPER
LEVEL SUPPORT THIS FAR WEST...BUT WITH THE EASTERLY FLOW...
SHOWERS MAY BE ABLE TO CLIP THE AFOREMENTIONED RIDGES. SURFACE
TEMPS WILL BE CRITICAL...BUT IT DOES APPEAR THAT AT LEAST THE
SHELTERED VALLEYS WILL BE ABLE TO HOLD ON TO TEMPS AT OR BELOW
FREEZING. WILL NEED TO INCLUDE THE MENTION OF FREEZING RAIN IN
THESE AREAS MONDAY.

LOW-LEVEL JET WILL GET STRONG WAA GOING MONDAY NIGHT AND TUESDAY.
STILL TOUGH TO GET A GOOD HANDLE ON HOW MUCH RAIN WILL REACH THE
REGION ON TUESDAY. THE UPPER LEVEL SUPPORT IS WEAK AND
UNORGANIZED...BUT THE LOW-LEVEL JET WILL PULL MOISTURE NORTHWARD
AS WELL. WILL INCREASE RAIN CHANCES FROM WEST TO EAST TUESDAY...BUT
KEEP EVERYTHING IN THE CHANCE CATEGORY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED...GIVEN
THE TIME PERIOD WHICH IT AFFECTS OUR AREA...IS STILL ON TRACK.
LONG RANGE ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE
CONVERGING ON A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.
THIS WILL MAKE FOR ALL LIQUID PRECIPITATION ON THE FRONT END.
TEMPERATURES WILL SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY
WITH 50S COMMON. COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF
MEXICO...SOUNDINGS ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES
TEMP DIFFERENTIAL BETWEEN H8 AND H5 TO NEARLY 0C. THIS COULD LEAD
TO ISOLATED THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE. FOR THE
TIME BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT
FOR BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT. DESPITE
PWATS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT. LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE
PROJECTED QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY. FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST. HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE
GROUND AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME. ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER. EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE. NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS. MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
MVFR CONDITIONS TO CONTINUE BEFORE LOWER LEVEL CLOUDS BEGIN TO
SCATTER OUT LATE THIS MORNING AS WINDS TRANSITION TO THE SOUTHWEST
AHEAD OF A LOW PRESSURE SYSTEM DEVELOPING OVER THE CENTRAL CONUS.

OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$







000
FXUS61 KPHI 210905
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
405 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER QUEBEC EARLY THIS MORNING WILL DRIFT
EASTWARD AND IT SHOULD REACH ATLANTIC CANADA ON MONDAY. WEAK LOW
PRESSURE IS FORECAST TO DEVELOP OFF THE CAROLINA COAST ON MONDAY
BEFORE MOVING SLOWLY NORTHEASTWARD AND DISSIPATING OFF THE
DELMARVA PENINSULA ON TUESDAY. LOW PRESSURE IS EXPECTED TO DEVELOP
AROUND THE CENTRAL GULF COAST REGION ON TUESDAY. THE LOW SHOULD
STRENGTHEN AS IT LIFTS NORTHWARD AND ACROSS THE EASTERN GREAT
LAKES ON WEDNESDAY NIGHT. THE LOW IS ANTICIPATED TO PULL A WARM
FRONT THROUGH OUR REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT
LATE ON WEDNESDAY NIGHT. HIGH PRESSURE IS EXPECTED TO FOLLOW FROM
THE SOUTHWEST FOR THURSDAY AND FRIDAY. ANOTHER COLD FRONT FROM THE
WEST IS FORECAST TO ARRIVE ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE REMAINS IN PLACE FROM EASTERN CANADA
SOUTHWARD ACROSS MUCH OF THE EAST COAST. THE NORTHERN HALF OF THE
AREA REMAINS UNDER THE EFFECTS OF THE WIDE SWATH OF STRATO CUMULUS
CLOUD COVER THAT HAS PLAGUED OUR AREA THE LAST SEVERAL DAYS, WHILE
THE SOUTHERN HALF HAS MID-HIGH LEVEL CLOUD COVER. THE CLOUD COVER
ACROSS THE SOUTHERN AREAS IS ASSOCIATED WITH A SHARP SHORT
WAVE/VORTICITY IMPULSE THAT IS APPROACHING THE AREA FROM THE WEST
THIS MORNING. AS THE SHORT WAVE MOVES THROUGH THE AREA THIS
MORNING INTO THE EARLY AFTERNOON, IT MAY HELP SCATTER OUT SOME OF
THE LOW STRATO CUMULUS CLOUDS, BUT IT WILL CONTINUE TO BRING ITS
OWN CLOUD COVER. SO OVERALL A OVERCAST TO MOSTLY CLOUDY DAY IS
EXPECTED FOR MOST OF THE DAY, WITH SOME PARTIAL CLEARING POSSIBLE
BY THE END OF THE DAY. WE DO NOT EXPECT ANY PRECIPITATION ACROSS
THE AREA WITH THIS SHORT WAVE SINCE THERE IS LIMITED MOISTURE,
EVIDENT FROM PW VALUES AROUND ONE-QUARTER TO ONE-THIRD OF AN INCH.
ALSO, THE GREATEST LOW-MID LEVEL LIFT IS FORECAST TO BE TO OUR
NORTHEAST THROUGH THE MORNING, ASSOCIATED WITH AN INVERTED TROUGH
ACROSS CONNECTICUT AND SOUTHEASTERN NEW YORK. THE TROUGH IS NOT
EXPECTED TO MAKE IT THIS FAR SOUTH, SO ANY SHOWERS SHOULD STAY TO
OUR NORTH. IF ANYTHING DID GET SQUEEZED OUT AS THE SHORT WAVE
MOVES THROUGH, IT SHOULD ONLY BE FLURRIES, BUT WE WILL KEEP THIS
OUT OF THE FORECAST FOR NOW.

HIGH TEMPERATURES ARE A BLEND OF MAV/MET MOS AND MOSGUIDE WHICH
WERE ALL IN PRETTY GOOD AGREEMENT.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE HIGH PRESSURE BEGINS TO RETREAT SOME OVERNIGHT TONIGHT, BUT
OUR AREA WILL STILL REMAIN ON THE SOUTHERN FRINGE. ANY PARTIAL
CLEARING THAT OCCURRED DURING THE DAY WILL CONTINUE INTO THE
EVENING, BUT HIGH LEVEL CLOUD COVER MAY BEGIN TO DEVELOP AND
SPREAD BACK INTO THE AREA OVERNIGHT AS A WEAK SHORT WAVE LIFTS
THROUGH THE AREA. WE ARE NOT EXPECTING ANY PRECIPITATION OVERNIGHT
AS THERE IS A LACK OF SIGNIFICANT VERTICAL MOISTURE.

LOW TEMPERATURES ARE A BLEND OF MAV/MET MOS AND MOSGUIDE WHICH
WERE ALL IN PRETTY GOOD AGREEMENT.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A MID LEVEL RIDGE AXIS SHOULD BE TO OUR EAST ON MONDAY. AN
IMPULSE TRAVELING IN THE MID LEVEL FLOW IS EXPECTED TO PASS
OVERHEAD ON MONDAY AFTERNOON. MOISTURE IS FORECAST TO SPREAD INTO
OUR REGION FROM THE SOUTH AT THAT TIME. WE HAVE MENTIONED A CHANCE
OF RAIN ARRIVING FROM SOUTH TO NORTH FROM THE LATE MORNING INTO
THE AFTERNOON HOURS. THE FORECAST TEMPERATURE PROFILES SUGGEST
THAT THE BOUNDARY LAYER WILL BE ABLE TO SUPPORT ALL RAIN EVEN UP
NORTH WHERE THE CHANCE FOR PRECIPITATION IS THE LOWEST IN OUR
REGION.

SURFACE HIGH PRESSURE IS FORECAST TO BE LOCATED OVER ATLANTIC
CANADA FROM MONDAY INTO TUESDAY. A RIDGE AXIS IS EXPECTED TO NOSE
SOUTHWESTWARD ALONG THE LEE OF THE APPALACHIANS AT THAT TIME WITH
AN INVERTED TROUGH DEVELOPING OFF THE COAST. WEAK LOW PRESSURE IS
ANTICIPATED TO DEVELOP ON THE TROUGH OFF THE CAROLINA COAST ON
MONDAY. THE FEATURE IS FORECAST TO REMAIN WEAK AS IT DRIFTS
NORTHEASTWARD REACHING THE WATERS OFF THE DELMARVA PENINSULA
BEFORE DISSIPATING ON TUESDAY.

MEANWHILE, A DEEP MID LEVEL TROUGH IS EXPECTED TO DIG OVER THE
MIDDLE PART OF THE COUNTRY ON MONDAY AND TUESDAY AS THE RIDGE OVER
THE WESTERN NORTH ATLANTIC BECOMES MORE PRONOUNCED. THE PATTERN
WILL RESULT IN THE DEVELOPMENT OF STRONG WARM ADVECTION OVER OUR
REGION FROM TUESDAY INTO TUESDAY NIGHT.

THE PATTERN SHOULD KEEP OUR REGION OVERCAST WITH A CHANCE OF RAIN
FROM MONDAY NIGHT INTO TUESDAY WITH THE PROBABILITY OF
PRECIPITATION INCREASING TO LIKELY FOR TUESDAY NIGHT. IT CONTINUES
TO APPEAR AS THOUGH THERE MAY BE POCKETS OF BELOW FREEZING
TEMPERATURES IN THE POCONOS AND IN FAR NORTHERN NEW JERSEY FROM
MONDAY NIGHT INTO TUESDAY MORNING TO POSSIBLY RESULT IN SOME
LOCALIZED LIGHT FREEZING RAIN.

SURFACE LOW PRESSURE IS ANTICIPATED TO DEVELOP AROUND THE CENTRAL
GULF COAST REGION ON TUESDAY IN RESPONSE TO THE DEEP MID LEVEL
TROUGH. THE LOW IS FORECAST TO STRENGTHEN AS IT MOVES NORTHWARD ON
WEDNESDAY AND ACROSS THE EASTERN GREAT LAKES ON WEDNESDAY NIGHT.
THE SYSTEM SHOULD HAVE AN OPPORTUNITY TO TAP INTO GULF MOISTURE
AND IT WILL BRING THE POTENTIAL FOR SOME MODERATE TO HEAVY
RAINFALL TO OUR REGION FROM LATE TUESDAY NIGHT INTO EARLY
WEDNESDAY NIGHT. THE CONSENSUS OF THE MODELS CONTINUES TO SUGGEST
REPRESENTATIVE RAINFALL AMOUNTS UP TO AN INCH TO AN INCH AND A
HALF IN OUR REGION DURING THE MID WEEK PERIOD.

THE LOW IS EXPECTED TO PULL A WARM FRONT THROUGH OUR REGION ON
WEDNESDAY WITH TEMPERATURES FORECAST TO RISE INTO THE 50S AND
LOWER 60S. A STRONG COLD FRONT IS FORECAST TO FOLLOW LATE ON
WEDNESDAY NIGHT WITH TEMPERATURES DROPPING BACK INTO THE UPPER 30S
AND LOWER 40S BY DAYBREAK ON THURSDAY. THE PROBABILITY OF
PRECIPITATION DECREASES RAPIDLY LATE ON WEDNESDAY NIGHT AS DRY AIR
IS EXPECTED TO BEGIN BUILDING INTO OUR REGION FROM THE WEST AND
SOUTHWEST. CONDITIONS ARE ANTICIPATED TO BECOME QUITE BREEZY IN
THE WAKE OF THE COLD FRONT FOR CHRISTMAS DAY. A WEST WIND AROUND
15 TO 20 MPH IS FORECAST WITH GUSTS NEAR 30 MPH. TEMPERATURES
SHOULD RETURN TO SEASONABLE LEVELS FOR THURSDAY, FRIDAY AND
SATURDAY.

RIDGING IS FORECAST TO DEVELOP AT THE SURFACE AND ALOFT FOR
THURSDAY NIGHT INTO FRIDAY WITH DRY WEATHER ANTICIPATED.

A MID LEVEL SHORT WAVE IS EXPECTED TO APPROACH FROM THE WEST
ALONG WITH AN ASSOCIATED SURFACE COLD FRONT. THE FRONT IS FORECAST
TO PASS THROUGH OUR REGION ON SATURDAY. THE SYSTEM IS FORECAST TO
BE FAST MOVING AND IT SHOULD NOT HAVE MUCH OF AN OPPORTUNITY TO
TAP INTO A MOISTURE SOURCE. AS A RESULT, WE WILL NOT FORECAST ANY
PRECIPITATION WITH THE FRONT AT THIS TIME.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

LOW-LEVEL CLOUDS REMAIN ACROSS MUCH OF THE NORTHERN HALF OF THE
AREA, WITH MVFR CIGS IN PLACE AT ABE. THE REST OF THE AREA SHOULD
REMAIN VFR, ESPECIALLY AS MID-LEVEL CLOUDS MOVE IN FROM THE
SOUTHWEST. THOSE AREAS THAT ARE MVFR ARE EXPECTED TO BECOME VFR
LATER THIS MORNING. ONCE EVERYONE BECOMES VFR, THEY SHOULD REMAIN
SO THROUGH THE REMAINDER OF THE TAF PERIOD.

LIGHT AND VARIABLE/CALM WINDS THIS MORNING WILL BECOME NORTH TO
NORTHWEST AROUND 5-8 KNOTS OR LESS DURING THE DAY. WINDS WILL
BECOME LIGHT AND VARIABLE/CALM ONCE AGAIN TONIGHT.

OUTLOOK...
MONDAY...MAINLY VFR WITH A CHANCE OF LIGHT RAIN SPREADING
NORTHWARD INTO OUR REGION.

MONDAY NIGHT AND TUESDAY...CONDITIONS POSSIBLY LOWERING INTO THE
MVFR CATEGORY WITH A CHANCE OF LIGHT RAIN.

TUESDAY NIGHT...MVFR AND IFR CONDITIONS ANTICIPATED WITH RAIN
LIKELY.

WEDNESDAY AND WEDNESDAY NIGHT...MVFR AND IFR CONDITIONS WITH RAIN
LIKELY. THE RAIN MAY BE HEAVY AT TIMES.

THURSDAY...CONDITIONS IMPROVING TO VFR WITH A GUSTY WEST WIND.

&&

.MARINE...
SUB-SMALL CRAFT ADVISORY CONDITIONS WILL REMAIN TODAY INTO
TONIGHT AS HIGH PRESSURE FROM THE NORTH WILL CONTINUE TO AFFECT
THE WATERS.

OUTLOOK...
MONDAY AND MONDAY NIGHT...NO MARINE HEADLINES ARE ANTICIPATED.

TUESDAY AND TUESDAY NIGHT...WAVE HEIGHTS ON OUR OCEAN WATERS MAY
BUILD TO 5 FEET IN A DEVELOPING ONSHORE FLOW.

WEDNESDAY...SOUTHERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 6 TO 9
FEET.

WEDNESDAY NIGHT...A SOUTH WIND BECOMING WEST. WIND GUSTS IN
EXCESS OF 25 KNOTS ARE EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS
MAY BE TO 6 TO 9 FEET.

THURSDAY...WESTERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BE TO 5 TO 7 FEET.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...IOVINO
NEAR TERM...ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/ROBERTSON
MARINE...IOVINO/ROBERTSON







000
FXUS61 KPHI 210905
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
405 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER QUEBEC EARLY THIS MORNING WILL DRIFT
EASTWARD AND IT SHOULD REACH ATLANTIC CANADA ON MONDAY. WEAK LOW
PRESSURE IS FORECAST TO DEVELOP OFF THE CAROLINA COAST ON MONDAY
BEFORE MOVING SLOWLY NORTHEASTWARD AND DISSIPATING OFF THE
DELMARVA PENINSULA ON TUESDAY. LOW PRESSURE IS EXPECTED TO DEVELOP
AROUND THE CENTRAL GULF COAST REGION ON TUESDAY. THE LOW SHOULD
STRENGTHEN AS IT LIFTS NORTHWARD AND ACROSS THE EASTERN GREAT
LAKES ON WEDNESDAY NIGHT. THE LOW IS ANTICIPATED TO PULL A WARM
FRONT THROUGH OUR REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT
LATE ON WEDNESDAY NIGHT. HIGH PRESSURE IS EXPECTED TO FOLLOW FROM
THE SOUTHWEST FOR THURSDAY AND FRIDAY. ANOTHER COLD FRONT FROM THE
WEST IS FORECAST TO ARRIVE ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE REMAINS IN PLACE FROM EASTERN CANADA
SOUTHWARD ACROSS MUCH OF THE EAST COAST. THE NORTHERN HALF OF THE
AREA REMAINS UNDER THE EFFECTS OF THE WIDE SWATH OF STRATO CUMULUS
CLOUD COVER THAT HAS PLAGUED OUR AREA THE LAST SEVERAL DAYS, WHILE
THE SOUTHERN HALF HAS MID-HIGH LEVEL CLOUD COVER. THE CLOUD COVER
ACROSS THE SOUTHERN AREAS IS ASSOCIATED WITH A SHARP SHORT
WAVE/VORTICITY IMPULSE THAT IS APPROACHING THE AREA FROM THE WEST
THIS MORNING. AS THE SHORT WAVE MOVES THROUGH THE AREA THIS
MORNING INTO THE EARLY AFTERNOON, IT MAY HELP SCATTER OUT SOME OF
THE LOW STRATO CUMULUS CLOUDS, BUT IT WILL CONTINUE TO BRING ITS
OWN CLOUD COVER. SO OVERALL A OVERCAST TO MOSTLY CLOUDY DAY IS
EXPECTED FOR MOST OF THE DAY, WITH SOME PARTIAL CLEARING POSSIBLE
BY THE END OF THE DAY. WE DO NOT EXPECT ANY PRECIPITATION ACROSS
THE AREA WITH THIS SHORT WAVE SINCE THERE IS LIMITED MOISTURE,
EVIDENT FROM PW VALUES AROUND ONE-QUARTER TO ONE-THIRD OF AN INCH.
ALSO, THE GREATEST LOW-MID LEVEL LIFT IS FORECAST TO BE TO OUR
NORTHEAST THROUGH THE MORNING, ASSOCIATED WITH AN INVERTED TROUGH
ACROSS CONNECTICUT AND SOUTHEASTERN NEW YORK. THE TROUGH IS NOT
EXPECTED TO MAKE IT THIS FAR SOUTH, SO ANY SHOWERS SHOULD STAY TO
OUR NORTH. IF ANYTHING DID GET SQUEEZED OUT AS THE SHORT WAVE
MOVES THROUGH, IT SHOULD ONLY BE FLURRIES, BUT WE WILL KEEP THIS
OUT OF THE FORECAST FOR NOW.

HIGH TEMPERATURES ARE A BLEND OF MAV/MET MOS AND MOSGUIDE WHICH
WERE ALL IN PRETTY GOOD AGREEMENT.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE HIGH PRESSURE BEGINS TO RETREAT SOME OVERNIGHT TONIGHT, BUT
OUR AREA WILL STILL REMAIN ON THE SOUTHERN FRINGE. ANY PARTIAL
CLEARING THAT OCCURRED DURING THE DAY WILL CONTINUE INTO THE
EVENING, BUT HIGH LEVEL CLOUD COVER MAY BEGIN TO DEVELOP AND
SPREAD BACK INTO THE AREA OVERNIGHT AS A WEAK SHORT WAVE LIFTS
THROUGH THE AREA. WE ARE NOT EXPECTING ANY PRECIPITATION OVERNIGHT
AS THERE IS A LACK OF SIGNIFICANT VERTICAL MOISTURE.

LOW TEMPERATURES ARE A BLEND OF MAV/MET MOS AND MOSGUIDE WHICH
WERE ALL IN PRETTY GOOD AGREEMENT.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A MID LEVEL RIDGE AXIS SHOULD BE TO OUR EAST ON MONDAY. AN
IMPULSE TRAVELING IN THE MID LEVEL FLOW IS EXPECTED TO PASS
OVERHEAD ON MONDAY AFTERNOON. MOISTURE IS FORECAST TO SPREAD INTO
OUR REGION FROM THE SOUTH AT THAT TIME. WE HAVE MENTIONED A CHANCE
OF RAIN ARRIVING FROM SOUTH TO NORTH FROM THE LATE MORNING INTO
THE AFTERNOON HOURS. THE FORECAST TEMPERATURE PROFILES SUGGEST
THAT THE BOUNDARY LAYER WILL BE ABLE TO SUPPORT ALL RAIN EVEN UP
NORTH WHERE THE CHANCE FOR PRECIPITATION IS THE LOWEST IN OUR
REGION.

SURFACE HIGH PRESSURE IS FORECAST TO BE LOCATED OVER ATLANTIC
CANADA FROM MONDAY INTO TUESDAY. A RIDGE AXIS IS EXPECTED TO NOSE
SOUTHWESTWARD ALONG THE LEE OF THE APPALACHIANS AT THAT TIME WITH
AN INVERTED TROUGH DEVELOPING OFF THE COAST. WEAK LOW PRESSURE IS
ANTICIPATED TO DEVELOP ON THE TROUGH OFF THE CAROLINA COAST ON
MONDAY. THE FEATURE IS FORECAST TO REMAIN WEAK AS IT DRIFTS
NORTHEASTWARD REACHING THE WATERS OFF THE DELMARVA PENINSULA
BEFORE DISSIPATING ON TUESDAY.

MEANWHILE, A DEEP MID LEVEL TROUGH IS EXPECTED TO DIG OVER THE
MIDDLE PART OF THE COUNTRY ON MONDAY AND TUESDAY AS THE RIDGE OVER
THE WESTERN NORTH ATLANTIC BECOMES MORE PRONOUNCED. THE PATTERN
WILL RESULT IN THE DEVELOPMENT OF STRONG WARM ADVECTION OVER OUR
REGION FROM TUESDAY INTO TUESDAY NIGHT.

THE PATTERN SHOULD KEEP OUR REGION OVERCAST WITH A CHANCE OF RAIN
FROM MONDAY NIGHT INTO TUESDAY WITH THE PROBABILITY OF
PRECIPITATION INCREASING TO LIKELY FOR TUESDAY NIGHT. IT CONTINUES
TO APPEAR AS THOUGH THERE MAY BE POCKETS OF BELOW FREEZING
TEMPERATURES IN THE POCONOS AND IN FAR NORTHERN NEW JERSEY FROM
MONDAY NIGHT INTO TUESDAY MORNING TO POSSIBLY RESULT IN SOME
LOCALIZED LIGHT FREEZING RAIN.

SURFACE LOW PRESSURE IS ANTICIPATED TO DEVELOP AROUND THE CENTRAL
GULF COAST REGION ON TUESDAY IN RESPONSE TO THE DEEP MID LEVEL
TROUGH. THE LOW IS FORECAST TO STRENGTHEN AS IT MOVES NORTHWARD ON
WEDNESDAY AND ACROSS THE EASTERN GREAT LAKES ON WEDNESDAY NIGHT.
THE SYSTEM SHOULD HAVE AN OPPORTUNITY TO TAP INTO GULF MOISTURE
AND IT WILL BRING THE POTENTIAL FOR SOME MODERATE TO HEAVY
RAINFALL TO OUR REGION FROM LATE TUESDAY NIGHT INTO EARLY
WEDNESDAY NIGHT. THE CONSENSUS OF THE MODELS CONTINUES TO SUGGEST
REPRESENTATIVE RAINFALL AMOUNTS UP TO AN INCH TO AN INCH AND A
HALF IN OUR REGION DURING THE MID WEEK PERIOD.

THE LOW IS EXPECTED TO PULL A WARM FRONT THROUGH OUR REGION ON
WEDNESDAY WITH TEMPERATURES FORECAST TO RISE INTO THE 50S AND
LOWER 60S. A STRONG COLD FRONT IS FORECAST TO FOLLOW LATE ON
WEDNESDAY NIGHT WITH TEMPERATURES DROPPING BACK INTO THE UPPER 30S
AND LOWER 40S BY DAYBREAK ON THURSDAY. THE PROBABILITY OF
PRECIPITATION DECREASES RAPIDLY LATE ON WEDNESDAY NIGHT AS DRY AIR
IS EXPECTED TO BEGIN BUILDING INTO OUR REGION FROM THE WEST AND
SOUTHWEST. CONDITIONS ARE ANTICIPATED TO BECOME QUITE BREEZY IN
THE WAKE OF THE COLD FRONT FOR CHRISTMAS DAY. A WEST WIND AROUND
15 TO 20 MPH IS FORECAST WITH GUSTS NEAR 30 MPH. TEMPERATURES
SHOULD RETURN TO SEASONABLE LEVELS FOR THURSDAY, FRIDAY AND
SATURDAY.

RIDGING IS FORECAST TO DEVELOP AT THE SURFACE AND ALOFT FOR
THURSDAY NIGHT INTO FRIDAY WITH DRY WEATHER ANTICIPATED.

A MID LEVEL SHORT WAVE IS EXPECTED TO APPROACH FROM THE WEST
ALONG WITH AN ASSOCIATED SURFACE COLD FRONT. THE FRONT IS FORECAST
TO PASS THROUGH OUR REGION ON SATURDAY. THE SYSTEM IS FORECAST TO
BE FAST MOVING AND IT SHOULD NOT HAVE MUCH OF AN OPPORTUNITY TO
TAP INTO A MOISTURE SOURCE. AS A RESULT, WE WILL NOT FORECAST ANY
PRECIPITATION WITH THE FRONT AT THIS TIME.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

LOW-LEVEL CLOUDS REMAIN ACROSS MUCH OF THE NORTHERN HALF OF THE
AREA, WITH MVFR CIGS IN PLACE AT ABE. THE REST OF THE AREA SHOULD
REMAIN VFR, ESPECIALLY AS MID-LEVEL CLOUDS MOVE IN FROM THE
SOUTHWEST. THOSE AREAS THAT ARE MVFR ARE EXPECTED TO BECOME VFR
LATER THIS MORNING. ONCE EVERYONE BECOMES VFR, THEY SHOULD REMAIN
SO THROUGH THE REMAINDER OF THE TAF PERIOD.

LIGHT AND VARIABLE/CALM WINDS THIS MORNING WILL BECOME NORTH TO
NORTHWEST AROUND 5-8 KNOTS OR LESS DURING THE DAY. WINDS WILL
BECOME LIGHT AND VARIABLE/CALM ONCE AGAIN TONIGHT.

OUTLOOK...
MONDAY...MAINLY VFR WITH A CHANCE OF LIGHT RAIN SPREADING
NORTHWARD INTO OUR REGION.

MONDAY NIGHT AND TUESDAY...CONDITIONS POSSIBLY LOWERING INTO THE
MVFR CATEGORY WITH A CHANCE OF LIGHT RAIN.

TUESDAY NIGHT...MVFR AND IFR CONDITIONS ANTICIPATED WITH RAIN
LIKELY.

WEDNESDAY AND WEDNESDAY NIGHT...MVFR AND IFR CONDITIONS WITH RAIN
LIKELY. THE RAIN MAY BE HEAVY AT TIMES.

THURSDAY...CONDITIONS IMPROVING TO VFR WITH A GUSTY WEST WIND.

&&

.MARINE...
SUB-SMALL CRAFT ADVISORY CONDITIONS WILL REMAIN TODAY INTO
TONIGHT AS HIGH PRESSURE FROM THE NORTH WILL CONTINUE TO AFFECT
THE WATERS.

OUTLOOK...
MONDAY AND MONDAY NIGHT...NO MARINE HEADLINES ARE ANTICIPATED.

TUESDAY AND TUESDAY NIGHT...WAVE HEIGHTS ON OUR OCEAN WATERS MAY
BUILD TO 5 FEET IN A DEVELOPING ONSHORE FLOW.

WEDNESDAY...SOUTHERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 6 TO 9
FEET.

WEDNESDAY NIGHT...A SOUTH WIND BECOMING WEST. WIND GUSTS IN
EXCESS OF 25 KNOTS ARE EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS
MAY BE TO 6 TO 9 FEET.

THURSDAY...WESTERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BE TO 5 TO 7 FEET.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...IOVINO
NEAR TERM...ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/ROBERTSON
MARINE...IOVINO/ROBERTSON







000
FXUS61 KPHI 210905
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
405 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER QUEBEC EARLY THIS MORNING WILL DRIFT
EASTWARD AND IT SHOULD REACH ATLANTIC CANADA ON MONDAY. WEAK LOW
PRESSURE IS FORECAST TO DEVELOP OFF THE CAROLINA COAST ON MONDAY
BEFORE MOVING SLOWLY NORTHEASTWARD AND DISSIPATING OFF THE
DELMARVA PENINSULA ON TUESDAY. LOW PRESSURE IS EXPECTED TO DEVELOP
AROUND THE CENTRAL GULF COAST REGION ON TUESDAY. THE LOW SHOULD
STRENGTHEN AS IT LIFTS NORTHWARD AND ACROSS THE EASTERN GREAT
LAKES ON WEDNESDAY NIGHT. THE LOW IS ANTICIPATED TO PULL A WARM
FRONT THROUGH OUR REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT
LATE ON WEDNESDAY NIGHT. HIGH PRESSURE IS EXPECTED TO FOLLOW FROM
THE SOUTHWEST FOR THURSDAY AND FRIDAY. ANOTHER COLD FRONT FROM THE
WEST IS FORECAST TO ARRIVE ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE REMAINS IN PLACE FROM EASTERN CANADA
SOUTHWARD ACROSS MUCH OF THE EAST COAST. THE NORTHERN HALF OF THE
AREA REMAINS UNDER THE EFFECTS OF THE WIDE SWATH OF STRATO CUMULUS
CLOUD COVER THAT HAS PLAGUED OUR AREA THE LAST SEVERAL DAYS, WHILE
THE SOUTHERN HALF HAS MID-HIGH LEVEL CLOUD COVER. THE CLOUD COVER
ACROSS THE SOUTHERN AREAS IS ASSOCIATED WITH A SHARP SHORT
WAVE/VORTICITY IMPULSE THAT IS APPROACHING THE AREA FROM THE WEST
THIS MORNING. AS THE SHORT WAVE MOVES THROUGH THE AREA THIS
MORNING INTO THE EARLY AFTERNOON, IT MAY HELP SCATTER OUT SOME OF
THE LOW STRATO CUMULUS CLOUDS, BUT IT WILL CONTINUE TO BRING ITS
OWN CLOUD COVER. SO OVERALL A OVERCAST TO MOSTLY CLOUDY DAY IS
EXPECTED FOR MOST OF THE DAY, WITH SOME PARTIAL CLEARING POSSIBLE
BY THE END OF THE DAY. WE DO NOT EXPECT ANY PRECIPITATION ACROSS
THE AREA WITH THIS SHORT WAVE SINCE THERE IS LIMITED MOISTURE,
EVIDENT FROM PW VALUES AROUND ONE-QUARTER TO ONE-THIRD OF AN INCH.
ALSO, THE GREATEST LOW-MID LEVEL LIFT IS FORECAST TO BE TO OUR
NORTHEAST THROUGH THE MORNING, ASSOCIATED WITH AN INVERTED TROUGH
ACROSS CONNECTICUT AND SOUTHEASTERN NEW YORK. THE TROUGH IS NOT
EXPECTED TO MAKE IT THIS FAR SOUTH, SO ANY SHOWERS SHOULD STAY TO
OUR NORTH. IF ANYTHING DID GET SQUEEZED OUT AS THE SHORT WAVE
MOVES THROUGH, IT SHOULD ONLY BE FLURRIES, BUT WE WILL KEEP THIS
OUT OF THE FORECAST FOR NOW.

HIGH TEMPERATURES ARE A BLEND OF MAV/MET MOS AND MOSGUIDE WHICH
WERE ALL IN PRETTY GOOD AGREEMENT.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE HIGH PRESSURE BEGINS TO RETREAT SOME OVERNIGHT TONIGHT, BUT
OUR AREA WILL STILL REMAIN ON THE SOUTHERN FRINGE. ANY PARTIAL
CLEARING THAT OCCURRED DURING THE DAY WILL CONTINUE INTO THE
EVENING, BUT HIGH LEVEL CLOUD COVER MAY BEGIN TO DEVELOP AND
SPREAD BACK INTO THE AREA OVERNIGHT AS A WEAK SHORT WAVE LIFTS
THROUGH THE AREA. WE ARE NOT EXPECTING ANY PRECIPITATION OVERNIGHT
AS THERE IS A LACK OF SIGNIFICANT VERTICAL MOISTURE.

LOW TEMPERATURES ARE A BLEND OF MAV/MET MOS AND MOSGUIDE WHICH
WERE ALL IN PRETTY GOOD AGREEMENT.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A MID LEVEL RIDGE AXIS SHOULD BE TO OUR EAST ON MONDAY. AN
IMPULSE TRAVELING IN THE MID LEVEL FLOW IS EXPECTED TO PASS
OVERHEAD ON MONDAY AFTERNOON. MOISTURE IS FORECAST TO SPREAD INTO
OUR REGION FROM THE SOUTH AT THAT TIME. WE HAVE MENTIONED A CHANCE
OF RAIN ARRIVING FROM SOUTH TO NORTH FROM THE LATE MORNING INTO
THE AFTERNOON HOURS. THE FORECAST TEMPERATURE PROFILES SUGGEST
THAT THE BOUNDARY LAYER WILL BE ABLE TO SUPPORT ALL RAIN EVEN UP
NORTH WHERE THE CHANCE FOR PRECIPITATION IS THE LOWEST IN OUR
REGION.

SURFACE HIGH PRESSURE IS FORECAST TO BE LOCATED OVER ATLANTIC
CANADA FROM MONDAY INTO TUESDAY. A RIDGE AXIS IS EXPECTED TO NOSE
SOUTHWESTWARD ALONG THE LEE OF THE APPALACHIANS AT THAT TIME WITH
AN INVERTED TROUGH DEVELOPING OFF THE COAST. WEAK LOW PRESSURE IS
ANTICIPATED TO DEVELOP ON THE TROUGH OFF THE CAROLINA COAST ON
MONDAY. THE FEATURE IS FORECAST TO REMAIN WEAK AS IT DRIFTS
NORTHEASTWARD REACHING THE WATERS OFF THE DELMARVA PENINSULA
BEFORE DISSIPATING ON TUESDAY.

MEANWHILE, A DEEP MID LEVEL TROUGH IS EXPECTED TO DIG OVER THE
MIDDLE PART OF THE COUNTRY ON MONDAY AND TUESDAY AS THE RIDGE OVER
THE WESTERN NORTH ATLANTIC BECOMES MORE PRONOUNCED. THE PATTERN
WILL RESULT IN THE DEVELOPMENT OF STRONG WARM ADVECTION OVER OUR
REGION FROM TUESDAY INTO TUESDAY NIGHT.

THE PATTERN SHOULD KEEP OUR REGION OVERCAST WITH A CHANCE OF RAIN
FROM MONDAY NIGHT INTO TUESDAY WITH THE PROBABILITY OF
PRECIPITATION INCREASING TO LIKELY FOR TUESDAY NIGHT. IT CONTINUES
TO APPEAR AS THOUGH THERE MAY BE POCKETS OF BELOW FREEZING
TEMPERATURES IN THE POCONOS AND IN FAR NORTHERN NEW JERSEY FROM
MONDAY NIGHT INTO TUESDAY MORNING TO POSSIBLY RESULT IN SOME
LOCALIZED LIGHT FREEZING RAIN.

SURFACE LOW PRESSURE IS ANTICIPATED TO DEVELOP AROUND THE CENTRAL
GULF COAST REGION ON TUESDAY IN RESPONSE TO THE DEEP MID LEVEL
TROUGH. THE LOW IS FORECAST TO STRENGTHEN AS IT MOVES NORTHWARD ON
WEDNESDAY AND ACROSS THE EASTERN GREAT LAKES ON WEDNESDAY NIGHT.
THE SYSTEM SHOULD HAVE AN OPPORTUNITY TO TAP INTO GULF MOISTURE
AND IT WILL BRING THE POTENTIAL FOR SOME MODERATE TO HEAVY
RAINFALL TO OUR REGION FROM LATE TUESDAY NIGHT INTO EARLY
WEDNESDAY NIGHT. THE CONSENSUS OF THE MODELS CONTINUES TO SUGGEST
REPRESENTATIVE RAINFALL AMOUNTS UP TO AN INCH TO AN INCH AND A
HALF IN OUR REGION DURING THE MID WEEK PERIOD.

THE LOW IS EXPECTED TO PULL A WARM FRONT THROUGH OUR REGION ON
WEDNESDAY WITH TEMPERATURES FORECAST TO RISE INTO THE 50S AND
LOWER 60S. A STRONG COLD FRONT IS FORECAST TO FOLLOW LATE ON
WEDNESDAY NIGHT WITH TEMPERATURES DROPPING BACK INTO THE UPPER 30S
AND LOWER 40S BY DAYBREAK ON THURSDAY. THE PROBABILITY OF
PRECIPITATION DECREASES RAPIDLY LATE ON WEDNESDAY NIGHT AS DRY AIR
IS EXPECTED TO BEGIN BUILDING INTO OUR REGION FROM THE WEST AND
SOUTHWEST. CONDITIONS ARE ANTICIPATED TO BECOME QUITE BREEZY IN
THE WAKE OF THE COLD FRONT FOR CHRISTMAS DAY. A WEST WIND AROUND
15 TO 20 MPH IS FORECAST WITH GUSTS NEAR 30 MPH. TEMPERATURES
SHOULD RETURN TO SEASONABLE LEVELS FOR THURSDAY, FRIDAY AND
SATURDAY.

RIDGING IS FORECAST TO DEVELOP AT THE SURFACE AND ALOFT FOR
THURSDAY NIGHT INTO FRIDAY WITH DRY WEATHER ANTICIPATED.

A MID LEVEL SHORT WAVE IS EXPECTED TO APPROACH FROM THE WEST
ALONG WITH AN ASSOCIATED SURFACE COLD FRONT. THE FRONT IS FORECAST
TO PASS THROUGH OUR REGION ON SATURDAY. THE SYSTEM IS FORECAST TO
BE FAST MOVING AND IT SHOULD NOT HAVE MUCH OF AN OPPORTUNITY TO
TAP INTO A MOISTURE SOURCE. AS A RESULT, WE WILL NOT FORECAST ANY
PRECIPITATION WITH THE FRONT AT THIS TIME.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

LOW-LEVEL CLOUDS REMAIN ACROSS MUCH OF THE NORTHERN HALF OF THE
AREA, WITH MVFR CIGS IN PLACE AT ABE. THE REST OF THE AREA SHOULD
REMAIN VFR, ESPECIALLY AS MID-LEVEL CLOUDS MOVE IN FROM THE
SOUTHWEST. THOSE AREAS THAT ARE MVFR ARE EXPECTED TO BECOME VFR
LATER THIS MORNING. ONCE EVERYONE BECOMES VFR, THEY SHOULD REMAIN
SO THROUGH THE REMAINDER OF THE TAF PERIOD.

LIGHT AND VARIABLE/CALM WINDS THIS MORNING WILL BECOME NORTH TO
NORTHWEST AROUND 5-8 KNOTS OR LESS DURING THE DAY. WINDS WILL
BECOME LIGHT AND VARIABLE/CALM ONCE AGAIN TONIGHT.

OUTLOOK...
MONDAY...MAINLY VFR WITH A CHANCE OF LIGHT RAIN SPREADING
NORTHWARD INTO OUR REGION.

MONDAY NIGHT AND TUESDAY...CONDITIONS POSSIBLY LOWERING INTO THE
MVFR CATEGORY WITH A CHANCE OF LIGHT RAIN.

TUESDAY NIGHT...MVFR AND IFR CONDITIONS ANTICIPATED WITH RAIN
LIKELY.

WEDNESDAY AND WEDNESDAY NIGHT...MVFR AND IFR CONDITIONS WITH RAIN
LIKELY. THE RAIN MAY BE HEAVY AT TIMES.

THURSDAY...CONDITIONS IMPROVING TO VFR WITH A GUSTY WEST WIND.

&&

.MARINE...
SUB-SMALL CRAFT ADVISORY CONDITIONS WILL REMAIN TODAY INTO
TONIGHT AS HIGH PRESSURE FROM THE NORTH WILL CONTINUE TO AFFECT
THE WATERS.

OUTLOOK...
MONDAY AND MONDAY NIGHT...NO MARINE HEADLINES ARE ANTICIPATED.

TUESDAY AND TUESDAY NIGHT...WAVE HEIGHTS ON OUR OCEAN WATERS MAY
BUILD TO 5 FEET IN A DEVELOPING ONSHORE FLOW.

WEDNESDAY...SOUTHERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 6 TO 9
FEET.

WEDNESDAY NIGHT...A SOUTH WIND BECOMING WEST. WIND GUSTS IN
EXCESS OF 25 KNOTS ARE EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS
MAY BE TO 6 TO 9 FEET.

THURSDAY...WESTERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BE TO 5 TO 7 FEET.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...IOVINO
NEAR TERM...ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/ROBERTSON
MARINE...IOVINO/ROBERTSON







000
FXUS61 KPHI 210905
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
405 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER QUEBEC EARLY THIS MORNING WILL DRIFT
EASTWARD AND IT SHOULD REACH ATLANTIC CANADA ON MONDAY. WEAK LOW
PRESSURE IS FORECAST TO DEVELOP OFF THE CAROLINA COAST ON MONDAY
BEFORE MOVING SLOWLY NORTHEASTWARD AND DISSIPATING OFF THE
DELMARVA PENINSULA ON TUESDAY. LOW PRESSURE IS EXPECTED TO DEVELOP
AROUND THE CENTRAL GULF COAST REGION ON TUESDAY. THE LOW SHOULD
STRENGTHEN AS IT LIFTS NORTHWARD AND ACROSS THE EASTERN GREAT
LAKES ON WEDNESDAY NIGHT. THE LOW IS ANTICIPATED TO PULL A WARM
FRONT THROUGH OUR REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT
LATE ON WEDNESDAY NIGHT. HIGH PRESSURE IS EXPECTED TO FOLLOW FROM
THE SOUTHWEST FOR THURSDAY AND FRIDAY. ANOTHER COLD FRONT FROM THE
WEST IS FORECAST TO ARRIVE ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SURFACE HIGH PRESSURE REMAINS IN PLACE FROM EASTERN CANADA
SOUTHWARD ACROSS MUCH OF THE EAST COAST. THE NORTHERN HALF OF THE
AREA REMAINS UNDER THE EFFECTS OF THE WIDE SWATH OF STRATO CUMULUS
CLOUD COVER THAT HAS PLAGUED OUR AREA THE LAST SEVERAL DAYS, WHILE
THE SOUTHERN HALF HAS MID-HIGH LEVEL CLOUD COVER. THE CLOUD COVER
ACROSS THE SOUTHERN AREAS IS ASSOCIATED WITH A SHARP SHORT
WAVE/VORTICITY IMPULSE THAT IS APPROACHING THE AREA FROM THE WEST
THIS MORNING. AS THE SHORT WAVE MOVES THROUGH THE AREA THIS
MORNING INTO THE EARLY AFTERNOON, IT MAY HELP SCATTER OUT SOME OF
THE LOW STRATO CUMULUS CLOUDS, BUT IT WILL CONTINUE TO BRING ITS
OWN CLOUD COVER. SO OVERALL A OVERCAST TO MOSTLY CLOUDY DAY IS
EXPECTED FOR MOST OF THE DAY, WITH SOME PARTIAL CLEARING POSSIBLE
BY THE END OF THE DAY. WE DO NOT EXPECT ANY PRECIPITATION ACROSS
THE AREA WITH THIS SHORT WAVE SINCE THERE IS LIMITED MOISTURE,
EVIDENT FROM PW VALUES AROUND ONE-QUARTER TO ONE-THIRD OF AN INCH.
ALSO, THE GREATEST LOW-MID LEVEL LIFT IS FORECAST TO BE TO OUR
NORTHEAST THROUGH THE MORNING, ASSOCIATED WITH AN INVERTED TROUGH
ACROSS CONNECTICUT AND SOUTHEASTERN NEW YORK. THE TROUGH IS NOT
EXPECTED TO MAKE IT THIS FAR SOUTH, SO ANY SHOWERS SHOULD STAY TO
OUR NORTH. IF ANYTHING DID GET SQUEEZED OUT AS THE SHORT WAVE
MOVES THROUGH, IT SHOULD ONLY BE FLURRIES, BUT WE WILL KEEP THIS
OUT OF THE FORECAST FOR NOW.

HIGH TEMPERATURES ARE A BLEND OF MAV/MET MOS AND MOSGUIDE WHICH
WERE ALL IN PRETTY GOOD AGREEMENT.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
THE HIGH PRESSURE BEGINS TO RETREAT SOME OVERNIGHT TONIGHT, BUT
OUR AREA WILL STILL REMAIN ON THE SOUTHERN FRINGE. ANY PARTIAL
CLEARING THAT OCCURRED DURING THE DAY WILL CONTINUE INTO THE
EVENING, BUT HIGH LEVEL CLOUD COVER MAY BEGIN TO DEVELOP AND
SPREAD BACK INTO THE AREA OVERNIGHT AS A WEAK SHORT WAVE LIFTS
THROUGH THE AREA. WE ARE NOT EXPECTING ANY PRECIPITATION OVERNIGHT
AS THERE IS A LACK OF SIGNIFICANT VERTICAL MOISTURE.

LOW TEMPERATURES ARE A BLEND OF MAV/MET MOS AND MOSGUIDE WHICH
WERE ALL IN PRETTY GOOD AGREEMENT.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
A MID LEVEL RIDGE AXIS SHOULD BE TO OUR EAST ON MONDAY. AN
IMPULSE TRAVELING IN THE MID LEVEL FLOW IS EXPECTED TO PASS
OVERHEAD ON MONDAY AFTERNOON. MOISTURE IS FORECAST TO SPREAD INTO
OUR REGION FROM THE SOUTH AT THAT TIME. WE HAVE MENTIONED A CHANCE
OF RAIN ARRIVING FROM SOUTH TO NORTH FROM THE LATE MORNING INTO
THE AFTERNOON HOURS. THE FORECAST TEMPERATURE PROFILES SUGGEST
THAT THE BOUNDARY LAYER WILL BE ABLE TO SUPPORT ALL RAIN EVEN UP
NORTH WHERE THE CHANCE FOR PRECIPITATION IS THE LOWEST IN OUR
REGION.

SURFACE HIGH PRESSURE IS FORECAST TO BE LOCATED OVER ATLANTIC
CANADA FROM MONDAY INTO TUESDAY. A RIDGE AXIS IS EXPECTED TO NOSE
SOUTHWESTWARD ALONG THE LEE OF THE APPALACHIANS AT THAT TIME WITH
AN INVERTED TROUGH DEVELOPING OFF THE COAST. WEAK LOW PRESSURE IS
ANTICIPATED TO DEVELOP ON THE TROUGH OFF THE CAROLINA COAST ON
MONDAY. THE FEATURE IS FORECAST TO REMAIN WEAK AS IT DRIFTS
NORTHEASTWARD REACHING THE WATERS OFF THE DELMARVA PENINSULA
BEFORE DISSIPATING ON TUESDAY.

MEANWHILE, A DEEP MID LEVEL TROUGH IS EXPECTED TO DIG OVER THE
MIDDLE PART OF THE COUNTRY ON MONDAY AND TUESDAY AS THE RIDGE OVER
THE WESTERN NORTH ATLANTIC BECOMES MORE PRONOUNCED. THE PATTERN
WILL RESULT IN THE DEVELOPMENT OF STRONG WARM ADVECTION OVER OUR
REGION FROM TUESDAY INTO TUESDAY NIGHT.

THE PATTERN SHOULD KEEP OUR REGION OVERCAST WITH A CHANCE OF RAIN
FROM MONDAY NIGHT INTO TUESDAY WITH THE PROBABILITY OF
PRECIPITATION INCREASING TO LIKELY FOR TUESDAY NIGHT. IT CONTINUES
TO APPEAR AS THOUGH THERE MAY BE POCKETS OF BELOW FREEZING
TEMPERATURES IN THE POCONOS AND IN FAR NORTHERN NEW JERSEY FROM
MONDAY NIGHT INTO TUESDAY MORNING TO POSSIBLY RESULT IN SOME
LOCALIZED LIGHT FREEZING RAIN.

SURFACE LOW PRESSURE IS ANTICIPATED TO DEVELOP AROUND THE CENTRAL
GULF COAST REGION ON TUESDAY IN RESPONSE TO THE DEEP MID LEVEL
TROUGH. THE LOW IS FORECAST TO STRENGTHEN AS IT MOVES NORTHWARD ON
WEDNESDAY AND ACROSS THE EASTERN GREAT LAKES ON WEDNESDAY NIGHT.
THE SYSTEM SHOULD HAVE AN OPPORTUNITY TO TAP INTO GULF MOISTURE
AND IT WILL BRING THE POTENTIAL FOR SOME MODERATE TO HEAVY
RAINFALL TO OUR REGION FROM LATE TUESDAY NIGHT INTO EARLY
WEDNESDAY NIGHT. THE CONSENSUS OF THE MODELS CONTINUES TO SUGGEST
REPRESENTATIVE RAINFALL AMOUNTS UP TO AN INCH TO AN INCH AND A
HALF IN OUR REGION DURING THE MID WEEK PERIOD.

THE LOW IS EXPECTED TO PULL A WARM FRONT THROUGH OUR REGION ON
WEDNESDAY WITH TEMPERATURES FORECAST TO RISE INTO THE 50S AND
LOWER 60S. A STRONG COLD FRONT IS FORECAST TO FOLLOW LATE ON
WEDNESDAY NIGHT WITH TEMPERATURES DROPPING BACK INTO THE UPPER 30S
AND LOWER 40S BY DAYBREAK ON THURSDAY. THE PROBABILITY OF
PRECIPITATION DECREASES RAPIDLY LATE ON WEDNESDAY NIGHT AS DRY AIR
IS EXPECTED TO BEGIN BUILDING INTO OUR REGION FROM THE WEST AND
SOUTHWEST. CONDITIONS ARE ANTICIPATED TO BECOME QUITE BREEZY IN
THE WAKE OF THE COLD FRONT FOR CHRISTMAS DAY. A WEST WIND AROUND
15 TO 20 MPH IS FORECAST WITH GUSTS NEAR 30 MPH. TEMPERATURES
SHOULD RETURN TO SEASONABLE LEVELS FOR THURSDAY, FRIDAY AND
SATURDAY.

RIDGING IS FORECAST TO DEVELOP AT THE SURFACE AND ALOFT FOR
THURSDAY NIGHT INTO FRIDAY WITH DRY WEATHER ANTICIPATED.

A MID LEVEL SHORT WAVE IS EXPECTED TO APPROACH FROM THE WEST
ALONG WITH AN ASSOCIATED SURFACE COLD FRONT. THE FRONT IS FORECAST
TO PASS THROUGH OUR REGION ON SATURDAY. THE SYSTEM IS FORECAST TO
BE FAST MOVING AND IT SHOULD NOT HAVE MUCH OF AN OPPORTUNITY TO
TAP INTO A MOISTURE SOURCE. AS A RESULT, WE WILL NOT FORECAST ANY
PRECIPITATION WITH THE FRONT AT THIS TIME.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

LOW-LEVEL CLOUDS REMAIN ACROSS MUCH OF THE NORTHERN HALF OF THE
AREA, WITH MVFR CIGS IN PLACE AT ABE. THE REST OF THE AREA SHOULD
REMAIN VFR, ESPECIALLY AS MID-LEVEL CLOUDS MOVE IN FROM THE
SOUTHWEST. THOSE AREAS THAT ARE MVFR ARE EXPECTED TO BECOME VFR
LATER THIS MORNING. ONCE EVERYONE BECOMES VFR, THEY SHOULD REMAIN
SO THROUGH THE REMAINDER OF THE TAF PERIOD.

LIGHT AND VARIABLE/CALM WINDS THIS MORNING WILL BECOME NORTH TO
NORTHWEST AROUND 5-8 KNOTS OR LESS DURING THE DAY. WINDS WILL
BECOME LIGHT AND VARIABLE/CALM ONCE AGAIN TONIGHT.

OUTLOOK...
MONDAY...MAINLY VFR WITH A CHANCE OF LIGHT RAIN SPREADING
NORTHWARD INTO OUR REGION.

MONDAY NIGHT AND TUESDAY...CONDITIONS POSSIBLY LOWERING INTO THE
MVFR CATEGORY WITH A CHANCE OF LIGHT RAIN.

TUESDAY NIGHT...MVFR AND IFR CONDITIONS ANTICIPATED WITH RAIN
LIKELY.

WEDNESDAY AND WEDNESDAY NIGHT...MVFR AND IFR CONDITIONS WITH RAIN
LIKELY. THE RAIN MAY BE HEAVY AT TIMES.

THURSDAY...CONDITIONS IMPROVING TO VFR WITH A GUSTY WEST WIND.

&&

.MARINE...
SUB-SMALL CRAFT ADVISORY CONDITIONS WILL REMAIN TODAY INTO
TONIGHT AS HIGH PRESSURE FROM THE NORTH WILL CONTINUE TO AFFECT
THE WATERS.

OUTLOOK...
MONDAY AND MONDAY NIGHT...NO MARINE HEADLINES ARE ANTICIPATED.

TUESDAY AND TUESDAY NIGHT...WAVE HEIGHTS ON OUR OCEAN WATERS MAY
BUILD TO 5 FEET IN A DEVELOPING ONSHORE FLOW.

WEDNESDAY...SOUTHERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 6 TO 9
FEET.

WEDNESDAY NIGHT...A SOUTH WIND BECOMING WEST. WIND GUSTS IN
EXCESS OF 25 KNOTS ARE EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS
MAY BE TO 6 TO 9 FEET.

THURSDAY...WESTERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BE TO 5 TO 7 FEET.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...IOVINO
NEAR TERM...ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/ROBERTSON
MARINE...IOVINO/ROBERTSON







000
FXUS61 KLWX 210900
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
400 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN WEDGES INTO THE MID-ATLANTIC THROUGH
EARLY IN THE WEEK. LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC
COAST LATE MONDAY. A STRONG COLD FRONT WILL THEN PASS THROUGH THE
AREA WEDNESDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE WINTER SOLSTICE IS AT 603PM EST TODAY...SUNDAY DECEMBER 21 2014.
THE SUN WILL BE AT THE LOWEST ANGLE OF THE YEAR WITH THE LEAST
AMOUNT OF DAYLIGHT. SUNSETS WILL START GETTING LATER AFTER TODAY.

A SHORTWAVE TROUGH WILL MOVE ACROSS THE NORTHERN MID-ATLANTIC WHILE
HIGH PRESSURE CONTINUES AT THE SURFACE THIS MORNING. MOISTURE IN THE
MID-LEVELS HAS MOVED NORTHWARD FROM THE SE US OVERNIGHT IN RESPONSE
TO THE JET STREAM ACROSS THE CAROLINAS. BKN-OVC CONDITIONS ARE
EXPECTED THIS MORNING AS THE CLOUD DECK STRETCHES BACK INTO
THE OHIO VALLEY. RIDGING ALOFT WILL LEAD TO LITTLE FORCING TODAY AND
ONCE MID-LEVEL MOISTURE MOVES EASTWARD BY AFTERNOON...THE SUN SHOULD
START TO SHOW ON THE FIRST DAY OF WINTER. HIGH PRESSURE AT THE SFC
WILL LEAD TO LIGHT NORTHERLY WINDS. FCST MAX TEMPS WILL REACH THE
30S IN THE MTNS AND LOW 40S ELSEWHERE. USED MET GUIDANCE SINCE IT
HAS BEEN DOING THE BEST THE LAST FEW DAYS.

HIGH PRESSURE WILL BEGIN TO WEDGE AGAINST THE APPALACHIAN REGION
TONIGHT AS AN UPPER LEVEL TROUGH BEGINS TO AMPLIFY ACROSS THE
CENTRAL US. THE JET STREAM ACROSS THE SE US WILL LEAD TO THE
DEVELOPMENT OF LOW PRESSURE OFF THE CAROLINA COAST. MOISTURE
ADVECTION INTO THE MID-ATLANTIC WILL LEAD TO PRECIPITATION MOVING
INTO THE REGION FROM THE SOUTH LATE TONIGHT. WENT WITH THE SREF MEAN
FOR PRECIP PROGRESSION. AT THIS TIME...MOISTURE SHOULD BE REACHING
THE GROUND ACROSS THE CENTRAL FOOTHILLS...SHENANDOAH
VALLEY...PIEDMONT EARLY MONDAY MORNING. HIGH PRESSURE WILL SERVE AS
A SOURCE OF COLD AIR AT THE SFC WITH TEMPS REACHING THE UPPER 20S TO
AROUND 30 BY MONDAY MORNING. 850-700MB THICKNESS VALUES AROUND 1550M
UP TO I-66 AND 1000-850MB THICKNESS VALUES AROUND 1310 WOULD RESULT
IN FZRA...SLEET MIXTURE EARLY MONDAY MORNING IF MOISTURE IS
AVAILABLE. TEMPS ALONG AND WEST OF THE BLUE RIDGE ARE EXPECTED TO BE
COLDER RESULTING IN A BETTER CHANCE FOR ICE ACCRETION.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
STILL HAVE SOME UNCERTAINTY REGARDING THE DETAILS OF MONDAY/MONDAY
NIGHT. GENERAL IDEA IS THAT PRECIP WILL SPREAD NORTHWARD THROUGH THE
CWA DURING THE DAY MONDAY...ALTHOUGH THE EXACT NORTH/NORTHWEST
EXTENT REMAINS SOMEWHAT IN QUESTION. ALSO IN QUESTION WILL BE TIMING
THE CHANGES TO THE THERMAL PROFILE THROUGH THE DAY...WHICH WILL
DETERMINE P-TYPE.

PREFER GENERAL IDEA FROM THE SREFS FOR POPS...ALTHOUGH POPS NOT
QUITE AS HIGH FURTHER NORTH TOWARD THE MASON DIXON LINE. LEANED
TOWARD SREFS FOR TEMPERATURE/PROFILE CONSIDERATIONS TOO. THIS
SUGGESTS THAT INITIAL PRECIP MAY BE SLEET OR FREEZING
RAIN...TRENDING TO JUST RAIN THROUGHOUT THE DAY ALTHOUGH WINTRY
PRECIP COULD LINGER LONGER OVER THE POTOMAC HIGHLANDS. HIGHEST
CONFIDENCE FOR ICING RESIDES ACROSS THE LOWER POTOMAC
HIGHLANDS/SHENANDOAH VALLEY/CENTRAL VA FOOTHILLS.

RISK OF FREEZING RAIN COULD CONTINUE OVER THE POTOMAC HIGHLANDS
MONDAY NIGHT ASSUMING THERE IS PRECIPITATION FALLING...BUT THIS IS
UNCERTAIN AS MODELS SUGGEST THE MAIN BATCH OF QPF LIFTS NORTHEAST IN
TANDEM WITH WEAK LOW PRESSURE OFF THE COAST.

WEDGE REMAINS IN PLACE TUESDAY. NOT SURE THERE/S A LOT OF MEASURABLE
PRECIP GOING ON...IT MAY BE MORE DRIZZLE BUT CONTINUE CHANCE POPS
FOR RAIN ACROSS THE CWA WITH GFS SHOWING BROAD LIGHT QPF. AM
EXPECTING ANY PRECIPITATION TO BE IN LIQUID FORM DURING THE DAY
TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
FOCUS THEN SHIFTS TO DEEP UPPER TROUGH/STRONG COLD FRONT OVER THE
MIDWEST/OHIO VALLEY TUESDAY NIGHT. DECENT PLUME OF MOISTURE
OVERRUNNING A WARM FRONT WILL BRING RAIN INTO THE MID-ATLANTIC
TUESDAY NIGHT.

AS LOW LEVEL JET STRENGTHENS ON WEDNESDAY...THIS SHOULD HELP TO PUSH
THE WARM FRONT TO THE NORTH. PW/S MAY INCREASE NEAR 1.5
INCHES...LIKELY LEADING TO PERIODS OF MODERATE RAINFALL ON
WEDNESDAY. INSTABILITY IS FORECAST TO BE WEAK SO NO THUNDER
MENTIONED BUT POTENTIAL EXISTS FOR SOME GUSTY SHOWERS GIVEN WIND
FIELDS OFF THE DECK. DESPITE CLOUDS/RAIN...MAXIMA SHOULD WARM WELL
INTO THE 50S AND POSSIBLY ECLIPSE 60 IN SOME AREAS.

STRONG COLD FRONT MOVES THROUGH WEDNESDAY NIGHT. SHOWERS END FROM
WEST TO EAST...AND COLD ADVECTION/TIGHT PRESSURE GRADIENT WILL BRING
A BLUSTERY AND COOLER DAY THURSDAY /MEX GUIDANCE LIKELY TOO WARM/.
NEXT COLD FRONT APPROACHES FRIDAY NIGHT OR SATURDAY.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS EXPECTED TODAY AND TONIGHT. MID LEVEL MOISTURE WILL
CONTINUE TO MOVE EASTWARD ACROSS THE REGION RESULTING IN BKN-OVC VFR
CIGS. CLEARING IS EXPECTED BY THIS AFTERNOON WITH A SCT-BKN 5K FEET
DECK EXPECTED INTO THE EVENING. CLOUDS WILL BUILD IN FROM THE SOUTH
TONIGHT AS LOW PRESSURE DEVELOPS OFF THE EAST COAST. MVFR/IFR CIGS
SHOULD REACH CHO BY MONDAY MORNING. LIGHT NRLY WINDS EXPECTED DURING
THE TAF PERIOD.

PRECIP SPREADS NORTH ON MONDAY...POSSIBLY BEGINNING AS A WINTRY MIX
OF -IP/-ZR BEFORE TRANSITIONING TO -RA. MVFR CONDITIONS LIKELY ON
MONDAY WITH PRECIP...DEGRADING INTO IFR/LIFR MONDAY NIGHT INTO
TUESDAY. RESTRICTIONS CONTINUE INTO WEDNESDAY WITH SHOWERS AND
POSSIBLE LLWS. COLD FRONT MOVES THROUGH WEDNESDAY NIGHT...WITH GUSTY
SURFACE WINDS THURSDAY.

&&

.MARINE...
LIGHT NRLY WINDS EXPECTED ON THE WATERS TODAY AND TONIGHT. WINDS
WILL REMAIN LIGHT BUT BECOME EASTERLY LATE TONIGHT AND INTO MONDAY
MORNING. RAIN AND/OR SLEET SHOULD REACH THE SRN WATERS MONDAY
MORNING BEFORE CHANGING TO ALL RAIN THROUGH MONDAY.

SCA CONDITIONS ARE POSSIBLE IN SOUTHERLY FLOW AHEAD OF A COLD FRONT
ON WEDNESDAY...THEN BEHIND THE FRONT FOR WEDNESDAY NIGHT AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...HAS/BPP
NEAR TERM...HAS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...HAS/BPP
MARINE...HAS/BPP







000
FXUS61 KLWX 210900
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
400 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN WEDGES INTO THE MID-ATLANTIC THROUGH
EARLY IN THE WEEK. LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC
COAST LATE MONDAY. A STRONG COLD FRONT WILL THEN PASS THROUGH THE
AREA WEDNESDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE WINTER SOLSTICE IS AT 603PM EST TODAY...SUNDAY DECEMBER 21 2014.
THE SUN WILL BE AT THE LOWEST ANGLE OF THE YEAR WITH THE LEAST
AMOUNT OF DAYLIGHT. SUNSETS WILL START GETTING LATER AFTER TODAY.

A SHORTWAVE TROUGH WILL MOVE ACROSS THE NORTHERN MID-ATLANTIC WHILE
HIGH PRESSURE CONTINUES AT THE SURFACE THIS MORNING. MOISTURE IN THE
MID-LEVELS HAS MOVED NORTHWARD FROM THE SE US OVERNIGHT IN RESPONSE
TO THE JET STREAM ACROSS THE CAROLINAS. BKN-OVC CONDITIONS ARE
EXPECTED THIS MORNING AS THE CLOUD DECK STRETCHES BACK INTO
THE OHIO VALLEY. RIDGING ALOFT WILL LEAD TO LITTLE FORCING TODAY AND
ONCE MID-LEVEL MOISTURE MOVES EASTWARD BY AFTERNOON...THE SUN SHOULD
START TO SHOW ON THE FIRST DAY OF WINTER. HIGH PRESSURE AT THE SFC
WILL LEAD TO LIGHT NORTHERLY WINDS. FCST MAX TEMPS WILL REACH THE
30S IN THE MTNS AND LOW 40S ELSEWHERE. USED MET GUIDANCE SINCE IT
HAS BEEN DOING THE BEST THE LAST FEW DAYS.

HIGH PRESSURE WILL BEGIN TO WEDGE AGAINST THE APPALACHIAN REGION
TONIGHT AS AN UPPER LEVEL TROUGH BEGINS TO AMPLIFY ACROSS THE
CENTRAL US. THE JET STREAM ACROSS THE SE US WILL LEAD TO THE
DEVELOPMENT OF LOW PRESSURE OFF THE CAROLINA COAST. MOISTURE
ADVECTION INTO THE MID-ATLANTIC WILL LEAD TO PRECIPITATION MOVING
INTO THE REGION FROM THE SOUTH LATE TONIGHT. WENT WITH THE SREF MEAN
FOR PRECIP PROGRESSION. AT THIS TIME...MOISTURE SHOULD BE REACHING
THE GROUND ACROSS THE CENTRAL FOOTHILLS...SHENANDOAH
VALLEY...PIEDMONT EARLY MONDAY MORNING. HIGH PRESSURE WILL SERVE AS
A SOURCE OF COLD AIR AT THE SFC WITH TEMPS REACHING THE UPPER 20S TO
AROUND 30 BY MONDAY MORNING. 850-700MB THICKNESS VALUES AROUND 1550M
UP TO I-66 AND 1000-850MB THICKNESS VALUES AROUND 1310 WOULD RESULT
IN FZRA...SLEET MIXTURE EARLY MONDAY MORNING IF MOISTURE IS
AVAILABLE. TEMPS ALONG AND WEST OF THE BLUE RIDGE ARE EXPECTED TO BE
COLDER RESULTING IN A BETTER CHANCE FOR ICE ACCRETION.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
STILL HAVE SOME UNCERTAINTY REGARDING THE DETAILS OF MONDAY/MONDAY
NIGHT. GENERAL IDEA IS THAT PRECIP WILL SPREAD NORTHWARD THROUGH THE
CWA DURING THE DAY MONDAY...ALTHOUGH THE EXACT NORTH/NORTHWEST
EXTENT REMAINS SOMEWHAT IN QUESTION. ALSO IN QUESTION WILL BE TIMING
THE CHANGES TO THE THERMAL PROFILE THROUGH THE DAY...WHICH WILL
DETERMINE P-TYPE.

PREFER GENERAL IDEA FROM THE SREFS FOR POPS...ALTHOUGH POPS NOT
QUITE AS HIGH FURTHER NORTH TOWARD THE MASON DIXON LINE. LEANED
TOWARD SREFS FOR TEMPERATURE/PROFILE CONSIDERATIONS TOO. THIS
SUGGESTS THAT INITIAL PRECIP MAY BE SLEET OR FREEZING
RAIN...TRENDING TO JUST RAIN THROUGHOUT THE DAY ALTHOUGH WINTRY
PRECIP COULD LINGER LONGER OVER THE POTOMAC HIGHLANDS. HIGHEST
CONFIDENCE FOR ICING RESIDES ACROSS THE LOWER POTOMAC
HIGHLANDS/SHENANDOAH VALLEY/CENTRAL VA FOOTHILLS.

RISK OF FREEZING RAIN COULD CONTINUE OVER THE POTOMAC HIGHLANDS
MONDAY NIGHT ASSUMING THERE IS PRECIPITATION FALLING...BUT THIS IS
UNCERTAIN AS MODELS SUGGEST THE MAIN BATCH OF QPF LIFTS NORTHEAST IN
TANDEM WITH WEAK LOW PRESSURE OFF THE COAST.

WEDGE REMAINS IN PLACE TUESDAY. NOT SURE THERE/S A LOT OF MEASURABLE
PRECIP GOING ON...IT MAY BE MORE DRIZZLE BUT CONTINUE CHANCE POPS
FOR RAIN ACROSS THE CWA WITH GFS SHOWING BROAD LIGHT QPF. AM
EXPECTING ANY PRECIPITATION TO BE IN LIQUID FORM DURING THE DAY
TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
FOCUS THEN SHIFTS TO DEEP UPPER TROUGH/STRONG COLD FRONT OVER THE
MIDWEST/OHIO VALLEY TUESDAY NIGHT. DECENT PLUME OF MOISTURE
OVERRUNNING A WARM FRONT WILL BRING RAIN INTO THE MID-ATLANTIC
TUESDAY NIGHT.

AS LOW LEVEL JET STRENGTHENS ON WEDNESDAY...THIS SHOULD HELP TO PUSH
THE WARM FRONT TO THE NORTH. PW/S MAY INCREASE NEAR 1.5
INCHES...LIKELY LEADING TO PERIODS OF MODERATE RAINFALL ON
WEDNESDAY. INSTABILITY IS FORECAST TO BE WEAK SO NO THUNDER
MENTIONED BUT POTENTIAL EXISTS FOR SOME GUSTY SHOWERS GIVEN WIND
FIELDS OFF THE DECK. DESPITE CLOUDS/RAIN...MAXIMA SHOULD WARM WELL
INTO THE 50S AND POSSIBLY ECLIPSE 60 IN SOME AREAS.

STRONG COLD FRONT MOVES THROUGH WEDNESDAY NIGHT. SHOWERS END FROM
WEST TO EAST...AND COLD ADVECTION/TIGHT PRESSURE GRADIENT WILL BRING
A BLUSTERY AND COOLER DAY THURSDAY /MEX GUIDANCE LIKELY TOO WARM/.
NEXT COLD FRONT APPROACHES FRIDAY NIGHT OR SATURDAY.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS EXPECTED TODAY AND TONIGHT. MID LEVEL MOISTURE WILL
CONTINUE TO MOVE EASTWARD ACROSS THE REGION RESULTING IN BKN-OVC VFR
CIGS. CLEARING IS EXPECTED BY THIS AFTERNOON WITH A SCT-BKN 5K FEET
DECK EXPECTED INTO THE EVENING. CLOUDS WILL BUILD IN FROM THE SOUTH
TONIGHT AS LOW PRESSURE DEVELOPS OFF THE EAST COAST. MVFR/IFR CIGS
SHOULD REACH CHO BY MONDAY MORNING. LIGHT NRLY WINDS EXPECTED DURING
THE TAF PERIOD.

PRECIP SPREADS NORTH ON MONDAY...POSSIBLY BEGINNING AS A WINTRY MIX
OF -IP/-ZR BEFORE TRANSITIONING TO -RA. MVFR CONDITIONS LIKELY ON
MONDAY WITH PRECIP...DEGRADING INTO IFR/LIFR MONDAY NIGHT INTO
TUESDAY. RESTRICTIONS CONTINUE INTO WEDNESDAY WITH SHOWERS AND
POSSIBLE LLWS. COLD FRONT MOVES THROUGH WEDNESDAY NIGHT...WITH GUSTY
SURFACE WINDS THURSDAY.

&&

.MARINE...
LIGHT NRLY WINDS EXPECTED ON THE WATERS TODAY AND TONIGHT. WINDS
WILL REMAIN LIGHT BUT BECOME EASTERLY LATE TONIGHT AND INTO MONDAY
MORNING. RAIN AND/OR SLEET SHOULD REACH THE SRN WATERS MONDAY
MORNING BEFORE CHANGING TO ALL RAIN THROUGH MONDAY.

SCA CONDITIONS ARE POSSIBLE IN SOUTHERLY FLOW AHEAD OF A COLD FRONT
ON WEDNESDAY...THEN BEHIND THE FRONT FOR WEDNESDAY NIGHT AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...HAS/BPP
NEAR TERM...HAS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...HAS/BPP
MARINE...HAS/BPP








000
FXUS61 KLWX 210900 CCA
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
400 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN WEDGED INTO THE MID-ATLANTIC THROUGH
EARLY IN THE WEEK. LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC
COAST LATE MONDAY. A STRONG COLD FRONT WILL THEN PASS THROUGH THE
AREA WEDNESDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE WINTER SOLSTICE IS AT 603PM EST TODAY...SUNDAY DECEMBER 21 2014.
THE SUN WILL BE AT THE LOWEST ANGLE OF THE YEAR WITH THE LEAST
AMOUNT OF DAYLIGHT. SUNSETS WILL START GETTING LATER AFTER TODAY.

A SHORTWAVE TROUGH WILL MOVE ACROSS THE NORTHERN MID-ATLANTIC WHILE
HIGH PRESSURE CONTINUES AT THE SURFACE THIS MORNING. MOISTURE IN THE
MID-LEVELS HAS MOVED NORTHWARD FROM THE SE US OVERNIGHT IN RESPONSE
TO THE JET STREAM ACROSS THE CAROLINAS. BKN-OVC CONDITIONS ARE
EXPECTED THIS MORNING AS THE CLOUD DECK STRETCHES BACK INTO
THE OHIO VALLEY. RIDGING ALOFT WILL LEAD TO LITTLE FORCING TODAY AND
ONCE MID-LEVEL MOISTURE MOVES EASTWARD BY AFTERNOON...THE SUN SHOULD
START TO SHOW ON THE FIRST DAY OF WINTER. HIGH PRESSURE AT THE SFC
WILL LEAD TO LIGHT NORTHERLY WINDS. FCST MAX TEMPS WILL REACH THE
30S IN THE MTNS AND LOW 40S ELSEWHERE. USED MET GUIDANCE SINCE IT
HAS BEEN DOING THE BEST THE LAST FEW DAYS.

HIGH PRESSURE WILL BEGIN TO WEDGE AGAINST THE APPALACHIAN REGION
TONIGHT AS AN UPPER LEVEL TROUGH BEGINS TO AMPLIFY ACROSS THE
CENTRAL US. THE JET STREAM ACROSS THE SE US WILL LEAD TO THE
DEVELOPMENT OF LOW PRESSURE OFF THE CAROLINA COAST. MOISTURE
ADVECTION INTO THE MID-ATLANTIC WILL LEAD TO PRECIPITATION MOVING
INTO THE REGION FROM THE SOUTH LATE TONIGHT. WENT WITH THE SREF MEAN
FOR PRECIP PROGRESSION. AT THIS TIME...MOISTURE SHOULD BE REACHING
THE GROUND ACROSS THE CENTRAL FOOTHILLS...SHENANDOAH
VALLEY...PIEDMONT EARLY MONDAY MORNING. HIGH PRESSURE WILL SERVE AS
A SOURCE OF COLD AIR AT THE SFC WITH TEMPS REACHING THE UPPER 20S TO
AROUND 30 BY MONDAY MORNING. 850-700MB THICKNESS VALUES AROUND 1550M
UP TO I-66 AND 1000-850MB THICKNESS VALUES AROUND 1310 WOULD RESULT
IN FZRA...SLEET MIXTURE EARLY MONDAY MORNING IF MOISTURE IS
AVAILABLE. TEMPS ALONG AND WEST OF THE BLUE RIDGE ARE EXPECTED TO BE
COLDER RESULTING IN A BETTER CHANCE FOR ICE ACCRETION.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
STILL HAVE SOME UNCERTAINTY REGARDING THE DETAILS OF MONDAY/MONDAY
NIGHT. GENERAL IDEA IS THAT PRECIP WILL SPREAD NORTHWARD THROUGH THE
CWA DURING THE DAY MONDAY...ALTHOUGH THE EXACT NORTH/NORTHWEST
EXTENT REMAINS SOMEWHAT IN QUESTION. ALSO IN QUESTION WILL BE TIMING
THE CHANGES TO THE THERMAL PROFILE THROUGH THE DAY...WHICH WILL
DETERMINE P-TYPE.

PREFER GENERAL IDEA FROM THE SREFS FOR POPS...ALTHOUGH POPS NOT
QUITE AS HIGH FURTHER NORTH TOWARD THE MASON DIXON LINE. LEANED
TOWARD SREFS FOR TEMPERATURE/PROFILE CONSIDERATIONS TOO. THIS
SUGGESTS THAT INITIAL PRECIP MAY BE SLEET OR FREEZING
RAIN...TRENDING TO JUST RAIN THROUGHOUT THE DAY ALTHOUGH WINTRY
PRECIP COULD LINGER LONGER OVER THE POTOMAC HIGHLANDS. HIGHEST
CONFIDENCE FOR ICING RESIDES ACROSS THE LOWER POTOMAC
HIGHLANDS/SHENANDOAH VALLEY/CENTRAL VA FOOTHILLS.

RISK OF FREEZING RAIN COULD CONTINUE OVER THE POTOMAC HIGHLANDS
MONDAY NIGHT ASSUMING THERE IS PRECIPITATION FALLING...BUT THIS IS
UNCERTAIN AS MODELS SUGGEST THE MAIN BATCH OF QPF LIFTS NORTHEAST IN
TANDEM WITH WEAK LOW PRESSURE OFF THE COAST.

WEDGE REMAINS IN PLACE TUESDAY. NOT SURE THERE/S A LOT OF MEASURABLE
PRECIP GOING ON...IT MAY BE MORE DRIZZLE BUT CONTINUE CHANCE POPS
FOR RAIN ACROSS THE CWA WITH GFS SHOWING BROAD LIGHT QPF. AM
EXPECTING ANY PRECIPITATION TO BE IN LIQUID FORM DURING THE DAY
TUESDAY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
FOCUS THEN SHIFTS TO DEEP UPPER TROUGH/STRONG COLD FRONT OVER THE
MIDWEST/OHIO VALLEY TUESDAY NIGHT. DECENT PLUME OF MOISTURE
OVERRUNNING A WARM FRONT WILL BRING RAIN INTO THE MID-ATLANTIC
TUESDAY NIGHT.

AS LOW LEVEL JET STRENGTHENS ON WEDNESDAY...THIS SHOULD HELP TO PUSH
THE WARM FRONT TO THE NORTH. PW/S MAY INCREASE NEAR 1.5
INCHES...LIKELY LEADING TO PERIODS OF MODERATE RAINFALL ON
WEDNESDAY. INSTABILITY IS FORECAST TO BE WEAK SO NO THUNDER
MENTIONED BUT POTENTIAL EXISTS FOR SOME GUSTY SHOWERS GIVEN WIND
FIELDS OFF THE DECK. DESPITE CLOUDS/RAIN...MAXIMA SHOULD WARM WELL
INTO THE 50S AND POSSIBLY ECLIPSE 60 IN SOME AREAS.

STRONG COLD FRONT MOVES THROUGH WEDNESDAY NIGHT. SHOWERS END FROM
WEST TO EAST...AND COLD ADVECTION/TIGHT PRESSURE GRADIENT WILL BRING
A BLUSTERY AND COOLER DAY THURSDAY /MEX GUIDANCE LIKELY TOO WARM/.
NEXT COLD FRONT APPROACHES FRIDAY NIGHT OR SATURDAY.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS EXPECTED TODAY AND TONIGHT. MID LEVEL MOISTURE WILL
CONTINUE TO MOVE EASTWARD ACROSS THE REGION RESULTING IN BKN-OVC VFR
CIGS. CLEARING IS EXPECTED BY THIS AFTERNOON WITH A SCT-BKN 5K FEET
DECK EXPECTED INTO THE EVENING. CLOUDS WILL BUILD IN FROM THE SOUTH
TONIGHT AS LOW PRESSURE DEVELOPS OFF THE EAST COAST. MVFR/IFR CIGS
SHOULD REACH CHO BY MONDAY MORNING. LIGHT NRLY WINDS EXPECTED DURING
THE TAF PERIOD.

PRECIP SPREADS NORTH ON MONDAY...POSSIBLY BEGINNING AS A WINTRY MIX
OF -IP/-ZR BEFORE TRANSITIONING TO -RA. MVFR CONDITIONS LIKELY ON
MONDAY WITH PRECIP...DEGRADING INTO IFR/LIFR MONDAY NIGHT INTO
TUESDAY. RESTRICTIONS CONTINUE INTO WEDNESDAY WITH SHOWERS AND
POSSIBLE LLWS. COLD FRONT MOVES THROUGH WEDNESDAY NIGHT...WITH GUSTY
SURFACE WINDS THURSDAY.

&&

.MARINE...
LIGHT NRLY WINDS EXPECTED ON THE WATERS TODAY AND TONIGHT. WINDS
WILL REMAIN LIGHT BUT BECOME EASTERLY LATE TONIGHT AND INTO MONDAY
MORNING. RAIN AND/OR SLEET SHOULD REACH THE SRN WATERS MONDAY
MORNING BEFORE CHANGING TO ALL RAIN THROUGH MONDAY.

SCA CONDITIONS ARE POSSIBLE IN SOUTHERLY FLOW AHEAD OF A COLD FRONT
ON WEDNESDAY...THEN BEHIND THE FRONT FOR WEDNESDAY NIGHT AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...HAS/BPP
NEAR TERM...HAS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...HAS/BPP
MARINE...HAS/BPP










000
FXUS61 KAKQ 210846
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
346 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY...THEN OFF THE COAST TONIGHT.
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG
THE CAROLINA COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS
THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /TODAY/...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY WITH A SFC TROF LCTD ACROSS
THE SRN APPALACHIANS. PLNTY OF MID/HIGH LVL MSTR SEEN ON TSCTNS FOR
THE DAY TO START OUT MSTLY CLDY TO CLDY. CLOUDS THIN OUT A BIT THIS
AFTRN...SPCLLY NRN HALF OF FA. ANTHR BLO NRML DAY AS CLOUDS HOLD TMPS
IN THE L-M40S.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
DRY THIS EVENING. CLOUDS QUICKLY THICKEN S-N LATE EVE AND ERLY
MORNING IN RESPONSE TO LOW PRS MOVG NE FROM GOM. TRICKY PART OF FCST
WILL BE HOW FAST PCPN OVERSPREADS THE FA AND WHAT FORM P-TYPE WILL
BE OVR THE PIEDMONT AS IN-SITU WEDGE DVLPS. DESPITE SOME TIMING
DIFFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS THE
AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN E OF
I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A NARROW
LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE PIEDMONT.
THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF I95 AND N OF
RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS NEAR FREEZING.
MAY EVEN SEE SOME WET SNOWFLAKES OVER CNTYS NW OF RIC...BUT NOT
SGNFCNT ENUF TO MENTION IN FCST ATTM. QPF LOOKS MINIMAL THRU
12Z...SO ABT THE ONLY ACTION NEEDED AT THIS POINT IS A MENTION IN
HWO. RAIN SRN CNTYS. MIN TMPS MAY LIKELY OCCUR IN THE EVENING WITH
STDY READINGS AFTR MIDNITE. LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN MON MORNING AS HIGH PRS MOVES INTO ERN CANADA.
THE NRMLLY COLDER CNTYS WILL LIKELY STAY NEAR 32 DEGREES THRU 15Z
OR SO AS THE PCPN OVERPSREADS THE ENTIRE FA. EXPECT A QUICK TRANSITION
OVER TO ALL RAIN MOST AREAS JUST AFTR 12Z XPCT FOR LOUISA/FLUVANNA/
WRN GOOCHLAND/NRN CUMBERLAND CNTYS WHERE A PERIOD OF MIXED SLEET/FZ
RAIN SHUD CONT THRU 15Z BEFORE TMPS INCH ABV 32. THESE ARE THE AREAS
WHERE AN ADVSRY MAY BE NEEDED MON MORNING FOR MINIMAL IMPACT AS TMPS
HOVER ARND 32. AREAS FROM CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST
TO DORCHESTER/WICOMICO MD MAY START OFF AS A RAIN/SLEET MIX AT THEN
QUICKLY GO OVR TO RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTRN AS THE
BULK OF LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT...40-45 EAST TOWARD THE ERN
SHORE & SERN CHES BAY... M40S-L50S SERN VA/NC.

LOW PRESSURE PROGGED TO LIFT NE ALONG THE CAROLINA COAST MONDAY NIGHT
WITH STDYST PCPN ENDING SW-NE BY 06Z. SNDGS INDCTG ENUF MSTR FOR LGT
RAIN / DRIZZLE THRU THE OVRNITE HRS. TMPS STDY IN THE M30S NW TO M40S
SE. QPF 1/4 TO 1/2 IN.

MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION TUESDAY. HOWEVER...
MOIST EASTERLY FLOW WILL PREVAIL. KEPT LOW CHC (30%) POPS THRU THE
DAY ALTHROUGH SOME DRIZZLE MAY LINGER THROUGH THE MORNING HRS. BIG
TMP DIFFERENCES SEEN IN MOS DATA WHERE NAM IS SOME 5-10 DEGREES
COLDER THAN THE GFS. GIVEN MODELS MAINTAIN AN ERLY SFC FLOW...WILL
SPLIT THE DIFFERENCE FOR NOW AND GO WITH HIGHS FROM THE M-U40S OVR
THE PIEDMONT TO M-U50S CSTL AREAS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS AND LIGHT WINDS EXPECTED TO CONTINUE THROUGH THE
06Z TAF PERIOD. BKN-OVC CLOUDS BETWEEN 8-10K FT WILL SLOWLY ERODE
THROUGH LATE MORNING.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
N-NE WINDS AOB 10 KT WILL PREVAIL TODAY WITH HIGH PRESSURE IN PLACE.
WINDS TURN MORE EASTERLY TONIGHT AND INCREASE TO 10-15 KT MOST AREAS
AS LOW PRESSURE ORGANIZING OFF THE SOUTHEAST COAST SLOWLY PUSHES
NORTH. THE SFC LOW CONTINUES TO MOVE NORTHEAST OF THE NC COAST ON
MONDAY...BUT WEAKENS BY LATE MONDAY/MONDAY NIGHT. WINDS WILL GENERALLY
REMAIN E-NE AOB 15 KT ALL WATERS DURING THIS TIME...BUT TENDING TO
BECOME MORE NORTHERLY AOB 10 KT BY EARLY TUES MORNING. LATEST
GUIDANCE INDICATES POTENTIAL FOR SEAS TO BUILD TO AROUND 5 FT OUT 20
NM LATE MON/MON EVE ACROSS THE SOUTHERN COASTAL WATERS. CONFIDENCE
NOT HIGH ENOUGH TO ISSUE A 3RD PERIOD SCA ATTM.

LIGHT NW WINDS EXPECTED TUES AS HIGH PRESSURE REMAINS IN PLACE OVER
THE MID-ATLANTIC...AND THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE DEEP SOUTH. WINDS TURN E-SE TUESDAY NIGHT AND GRADUALLY BEGIN TO
INCREASE AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. A STRONG
COLD FRONT APPROACHES THE WATERS FROM THE WEST ON WEDNESDAY WITH
WINDS BECOMING SOUTHERLY AND INCREASING TO SCA THRESHOLDS (SAVE THE
RIVERS). THE FRONT QUICKLY SWEEPS THROUGH THE AREA WED NIGHT AND
OFFSHORE EARLY THURSDAY. WINDS REMAIN ABOVE SCA LEVELS THRU LATE
THURSDAY WHILE BECOMING SW THEN W. HIGH PRESSURE RETURNS THU NIGHT
INTO THE START OF NEXT WEEKEND FOR IMPROVED CONDITIONS. SEAS WILL
GENERALLY BUILD TO 5-7 FT ON WED BEFORE SUBSIDING AGAIN LATE THU.
WAVES WILL REACH 4 FT ON THE CHES BAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...MPR
LONG TERM...BMD
AVIATION...JDM
MARINE...JDM






000
FXUS61 KAKQ 210846
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
346 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY...THEN OFF THE COAST TONIGHT.
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG
THE CAROLINA COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS
THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /TODAY/...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY WITH A SFC TROF LCTD ACROSS
THE SRN APPALACHIANS. PLNTY OF MID/HIGH LVL MSTR SEEN ON TSCTNS FOR
THE DAY TO START OUT MSTLY CLDY TO CLDY. CLOUDS THIN OUT A BIT THIS
AFTRN...SPCLLY NRN HALF OF FA. ANTHR BLO NRML DAY AS CLOUDS HOLD TMPS
IN THE L-M40S.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
DRY THIS EVENING. CLOUDS QUICKLY THICKEN S-N LATE EVE AND ERLY
MORNING IN RESPONSE TO LOW PRS MOVG NE FROM GOM. TRICKY PART OF FCST
WILL BE HOW FAST PCPN OVERSPREADS THE FA AND WHAT FORM P-TYPE WILL
BE OVR THE PIEDMONT AS IN-SITU WEDGE DVLPS. DESPITE SOME TIMING
DIFFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS THE
AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN E OF
I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A NARROW
LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE PIEDMONT.
THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF I95 AND N OF
RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS NEAR FREEZING.
MAY EVEN SEE SOME WET SNOWFLAKES OVER CNTYS NW OF RIC...BUT NOT
SGNFCNT ENUF TO MENTION IN FCST ATTM. QPF LOOKS MINIMAL THRU
12Z...SO ABT THE ONLY ACTION NEEDED AT THIS POINT IS A MENTION IN
HWO. RAIN SRN CNTYS. MIN TMPS MAY LIKELY OCCUR IN THE EVENING WITH
STDY READINGS AFTR MIDNITE. LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN MON MORNING AS HIGH PRS MOVES INTO ERN CANADA.
THE NRMLLY COLDER CNTYS WILL LIKELY STAY NEAR 32 DEGREES THRU 15Z
OR SO AS THE PCPN OVERPSREADS THE ENTIRE FA. EXPECT A QUICK TRANSITION
OVER TO ALL RAIN MOST AREAS JUST AFTR 12Z XPCT FOR LOUISA/FLUVANNA/
WRN GOOCHLAND/NRN CUMBERLAND CNTYS WHERE A PERIOD OF MIXED SLEET/FZ
RAIN SHUD CONT THRU 15Z BEFORE TMPS INCH ABV 32. THESE ARE THE AREAS
WHERE AN ADVSRY MAY BE NEEDED MON MORNING FOR MINIMAL IMPACT AS TMPS
HOVER ARND 32. AREAS FROM CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST
TO DORCHESTER/WICOMICO MD MAY START OFF AS A RAIN/SLEET MIX AT THEN
QUICKLY GO OVR TO RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTRN AS THE
BULK OF LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT...40-45 EAST TOWARD THE ERN
SHORE & SERN CHES BAY... M40S-L50S SERN VA/NC.

LOW PRESSURE PROGGED TO LIFT NE ALONG THE CAROLINA COAST MONDAY NIGHT
WITH STDYST PCPN ENDING SW-NE BY 06Z. SNDGS INDCTG ENUF MSTR FOR LGT
RAIN / DRIZZLE THRU THE OVRNITE HRS. TMPS STDY IN THE M30S NW TO M40S
SE. QPF 1/4 TO 1/2 IN.

MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION TUESDAY. HOWEVER...
MOIST EASTERLY FLOW WILL PREVAIL. KEPT LOW CHC (30%) POPS THRU THE
DAY ALTHROUGH SOME DRIZZLE MAY LINGER THROUGH THE MORNING HRS. BIG
TMP DIFFERENCES SEEN IN MOS DATA WHERE NAM IS SOME 5-10 DEGREES
COLDER THAN THE GFS. GIVEN MODELS MAINTAIN AN ERLY SFC FLOW...WILL
SPLIT THE DIFFERENCE FOR NOW AND GO WITH HIGHS FROM THE M-U40S OVR
THE PIEDMONT TO M-U50S CSTL AREAS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS AND LIGHT WINDS EXPECTED TO CONTINUE THROUGH THE
06Z TAF PERIOD. BKN-OVC CLOUDS BETWEEN 8-10K FT WILL SLOWLY ERODE
THROUGH LATE MORNING.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
N-NE WINDS AOB 10 KT WILL PREVAIL TODAY WITH HIGH PRESSURE IN PLACE.
WINDS TURN MORE EASTERLY TONIGHT AND INCREASE TO 10-15 KT MOST AREAS
AS LOW PRESSURE ORGANIZING OFF THE SOUTHEAST COAST SLOWLY PUSHES
NORTH. THE SFC LOW CONTINUES TO MOVE NORTHEAST OF THE NC COAST ON
MONDAY...BUT WEAKENS BY LATE MONDAY/MONDAY NIGHT. WINDS WILL GENERALLY
REMAIN E-NE AOB 15 KT ALL WATERS DURING THIS TIME...BUT TENDING TO
BECOME MORE NORTHERLY AOB 10 KT BY EARLY TUES MORNING. LATEST
GUIDANCE INDICATES POTENTIAL FOR SEAS TO BUILD TO AROUND 5 FT OUT 20
NM LATE MON/MON EVE ACROSS THE SOUTHERN COASTAL WATERS. CONFIDENCE
NOT HIGH ENOUGH TO ISSUE A 3RD PERIOD SCA ATTM.

LIGHT NW WINDS EXPECTED TUES AS HIGH PRESSURE REMAINS IN PLACE OVER
THE MID-ATLANTIC...AND THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE DEEP SOUTH. WINDS TURN E-SE TUESDAY NIGHT AND GRADUALLY BEGIN TO
INCREASE AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. A STRONG
COLD FRONT APPROACHES THE WATERS FROM THE WEST ON WEDNESDAY WITH
WINDS BECOMING SOUTHERLY AND INCREASING TO SCA THRESHOLDS (SAVE THE
RIVERS). THE FRONT QUICKLY SWEEPS THROUGH THE AREA WED NIGHT AND
OFFSHORE EARLY THURSDAY. WINDS REMAIN ABOVE SCA LEVELS THRU LATE
THURSDAY WHILE BECOMING SW THEN W. HIGH PRESSURE RETURNS THU NIGHT
INTO THE START OF NEXT WEEKEND FOR IMPROVED CONDITIONS. SEAS WILL
GENERALLY BUILD TO 5-7 FT ON WED BEFORE SUBSIDING AGAIN LATE THU.
WAVES WILL REACH 4 FT ON THE CHES BAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...MPR
LONG TERM...BMD
AVIATION...JDM
MARINE...JDM






000
FXUS61 KAKQ 210846
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
346 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY...THEN OFF THE COAST TONIGHT.
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG
THE CAROLINA COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS
THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /TODAY/...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY WITH A SFC TROF LCTD ACROSS
THE SRN APPALACHIANS. PLNTY OF MID/HIGH LVL MSTR SEEN ON TSCTNS FOR
THE DAY TO START OUT MSTLY CLDY TO CLDY. CLOUDS THIN OUT A BIT THIS
AFTRN...SPCLLY NRN HALF OF FA. ANTHR BLO NRML DAY AS CLOUDS HOLD TMPS
IN THE L-M40S.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
DRY THIS EVENING. CLOUDS QUICKLY THICKEN S-N LATE EVE AND ERLY
MORNING IN RESPONSE TO LOW PRS MOVG NE FROM GOM. TRICKY PART OF FCST
WILL BE HOW FAST PCPN OVERSPREADS THE FA AND WHAT FORM P-TYPE WILL
BE OVR THE PIEDMONT AS IN-SITU WEDGE DVLPS. DESPITE SOME TIMING
DIFFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS THE
AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN E OF
I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A NARROW
LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE PIEDMONT.
THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF I95 AND N OF
RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS NEAR FREEZING.
MAY EVEN SEE SOME WET SNOWFLAKES OVER CNTYS NW OF RIC...BUT NOT
SGNFCNT ENUF TO MENTION IN FCST ATTM. QPF LOOKS MINIMAL THRU
12Z...SO ABT THE ONLY ACTION NEEDED AT THIS POINT IS A MENTION IN
HWO. RAIN SRN CNTYS. MIN TMPS MAY LIKELY OCCUR IN THE EVENING WITH
STDY READINGS AFTR MIDNITE. LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN MON MORNING AS HIGH PRS MOVES INTO ERN CANADA.
THE NRMLLY COLDER CNTYS WILL LIKELY STAY NEAR 32 DEGREES THRU 15Z
OR SO AS THE PCPN OVERPSREADS THE ENTIRE FA. EXPECT A QUICK TRANSITION
OVER TO ALL RAIN MOST AREAS JUST AFTR 12Z XPCT FOR LOUISA/FLUVANNA/
WRN GOOCHLAND/NRN CUMBERLAND CNTYS WHERE A PERIOD OF MIXED SLEET/FZ
RAIN SHUD CONT THRU 15Z BEFORE TMPS INCH ABV 32. THESE ARE THE AREAS
WHERE AN ADVSRY MAY BE NEEDED MON MORNING FOR MINIMAL IMPACT AS TMPS
HOVER ARND 32. AREAS FROM CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST
TO DORCHESTER/WICOMICO MD MAY START OFF AS A RAIN/SLEET MIX AT THEN
QUICKLY GO OVR TO RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTRN AS THE
BULK OF LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT...40-45 EAST TOWARD THE ERN
SHORE & SERN CHES BAY... M40S-L50S SERN VA/NC.

LOW PRESSURE PROGGED TO LIFT NE ALONG THE CAROLINA COAST MONDAY NIGHT
WITH STDYST PCPN ENDING SW-NE BY 06Z. SNDGS INDCTG ENUF MSTR FOR LGT
RAIN / DRIZZLE THRU THE OVRNITE HRS. TMPS STDY IN THE M30S NW TO M40S
SE. QPF 1/4 TO 1/2 IN.

MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION TUESDAY. HOWEVER...
MOIST EASTERLY FLOW WILL PREVAIL. KEPT LOW CHC (30%) POPS THRU THE
DAY ALTHROUGH SOME DRIZZLE MAY LINGER THROUGH THE MORNING HRS. BIG
TMP DIFFERENCES SEEN IN MOS DATA WHERE NAM IS SOME 5-10 DEGREES
COLDER THAN THE GFS. GIVEN MODELS MAINTAIN AN ERLY SFC FLOW...WILL
SPLIT THE DIFFERENCE FOR NOW AND GO WITH HIGHS FROM THE M-U40S OVR
THE PIEDMONT TO M-U50S CSTL AREAS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS AND LIGHT WINDS EXPECTED TO CONTINUE THROUGH THE
06Z TAF PERIOD. BKN-OVC CLOUDS BETWEEN 8-10K FT WILL SLOWLY ERODE
THROUGH LATE MORNING.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
N-NE WINDS AOB 10 KT WILL PREVAIL TODAY WITH HIGH PRESSURE IN PLACE.
WINDS TURN MORE EASTERLY TONIGHT AND INCREASE TO 10-15 KT MOST AREAS
AS LOW PRESSURE ORGANIZING OFF THE SOUTHEAST COAST SLOWLY PUSHES
NORTH. THE SFC LOW CONTINUES TO MOVE NORTHEAST OF THE NC COAST ON
MONDAY...BUT WEAKENS BY LATE MONDAY/MONDAY NIGHT. WINDS WILL GENERALLY
REMAIN E-NE AOB 15 KT ALL WATERS DURING THIS TIME...BUT TENDING TO
BECOME MORE NORTHERLY AOB 10 KT BY EARLY TUES MORNING. LATEST
GUIDANCE INDICATES POTENTIAL FOR SEAS TO BUILD TO AROUND 5 FT OUT 20
NM LATE MON/MON EVE ACROSS THE SOUTHERN COASTAL WATERS. CONFIDENCE
NOT HIGH ENOUGH TO ISSUE A 3RD PERIOD SCA ATTM.

LIGHT NW WINDS EXPECTED TUES AS HIGH PRESSURE REMAINS IN PLACE OVER
THE MID-ATLANTIC...AND THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE DEEP SOUTH. WINDS TURN E-SE TUESDAY NIGHT AND GRADUALLY BEGIN TO
INCREASE AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. A STRONG
COLD FRONT APPROACHES THE WATERS FROM THE WEST ON WEDNESDAY WITH
WINDS BECOMING SOUTHERLY AND INCREASING TO SCA THRESHOLDS (SAVE THE
RIVERS). THE FRONT QUICKLY SWEEPS THROUGH THE AREA WED NIGHT AND
OFFSHORE EARLY THURSDAY. WINDS REMAIN ABOVE SCA LEVELS THRU LATE
THURSDAY WHILE BECOMING SW THEN W. HIGH PRESSURE RETURNS THU NIGHT
INTO THE START OF NEXT WEEKEND FOR IMPROVED CONDITIONS. SEAS WILL
GENERALLY BUILD TO 5-7 FT ON WED BEFORE SUBSIDING AGAIN LATE THU.
WAVES WILL REACH 4 FT ON THE CHES BAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...MPR
LONG TERM...BMD
AVIATION...JDM
MARINE...JDM






000
FXUS61 KAKQ 210846
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
346 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY...THEN OFF THE COAST TONIGHT.
LOW PRESSURE MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG
THE CAROLINA COAST MONDAY INTO TUESDAY. A STRONG COLD FRONT WILL CROSS
THE AREA WEDNESDAY NIGHT. HIGH PRESSURE RETURNS BY CHRISTMAS DAY.

&&

.NEAR TERM /TODAY/...
HIGH PRESSURE MOVES ACROSS THE AREA TODAY WITH A SFC TROF LCTD ACROSS
THE SRN APPALACHIANS. PLNTY OF MID/HIGH LVL MSTR SEEN ON TSCTNS FOR
THE DAY TO START OUT MSTLY CLDY TO CLDY. CLOUDS THIN OUT A BIT THIS
AFTRN...SPCLLY NRN HALF OF FA. ANTHR BLO NRML DAY AS CLOUDS HOLD TMPS
IN THE L-M40S.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
DRY THIS EVENING. CLOUDS QUICKLY THICKEN S-N LATE EVE AND ERLY
MORNING IN RESPONSE TO LOW PRS MOVG NE FROM GOM. TRICKY PART OF FCST
WILL BE HOW FAST PCPN OVERSPREADS THE FA AND WHAT FORM P-TYPE WILL
BE OVR THE PIEDMONT AS IN-SITU WEDGE DVLPS. DESPITE SOME TIMING
DIFFFERENCES LTST MODELS IN GNRL AGREEMENT THAT PCPN OVERSPREADS THE
AREA S-N BTWN 06Z-12Z. LL THICKNESSES WARM ENUF FOR LIQUID PCPN E OF
I95 BUT REMAIN MARGINAL W OF I95. BUFKIT SNDGS CONT TO SHOW A NARROW
LAYER OF BLO FREEZING SFC TMPS THRU 15Z OR SO ACROSS THE PIEDMONT.
THNK P-TYPE WILL START OFF AS A FEW HRS OF SLEET W OF I95 AND N OF
RT 460 LATE TONIGHT DUE TO EVAP COOLING WITH TMPS NEAR FREEZING.
MAY EVEN SEE SOME WET SNOWFLAKES OVER CNTYS NW OF RIC...BUT NOT
SGNFCNT ENUF TO MENTION IN FCST ATTM. QPF LOOKS MINIMAL THRU
12Z...SO ABT THE ONLY ACTION NEEDED AT THIS POINT IS A MENTION IN
HWO. RAIN SRN CNTYS. MIN TMPS MAY LIKELY OCCUR IN THE EVENING WITH
STDY READINGS AFTR MIDNITE. LOWS U20S-M30S.

WEDGE BEGINS TO WEAKEN MON MORNING AS HIGH PRS MOVES INTO ERN CANADA.
THE NRMLLY COLDER CNTYS WILL LIKELY STAY NEAR 32 DEGREES THRU 15Z
OR SO AS THE PCPN OVERPSREADS THE ENTIRE FA. EXPECT A QUICK TRANSITION
OVER TO ALL RAIN MOST AREAS JUST AFTR 12Z XPCT FOR LOUISA/FLUVANNA/
WRN GOOCHLAND/NRN CUMBERLAND CNTYS WHERE A PERIOD OF MIXED SLEET/FZ
RAIN SHUD CONT THRU 15Z BEFORE TMPS INCH ABV 32. THESE ARE THE AREAS
WHERE AN ADVSRY MAY BE NEEDED MON MORNING FOR MINIMAL IMPACT AS TMPS
HOVER ARND 32. AREAS FROM CAROLINE/NRN HALF OF NRN NECK CNTYS ON EAST
TO DORCHESTER/WICOMICO MD MAY START OFF AS A RAIN/SLEET MIX AT THEN
QUICKLY GO OVR TO RAIN. RAIN THEN BECOMES WIDESPREAD MON AFTRN AS THE
BULK OF LIFT/MSTR TRACKS ACROSS THE FA. A RATHER COLD RAIN AS TMPS
STRUGGLE TO GET OUT OF THE 30S PIEDMONT...40-45 EAST TOWARD THE ERN
SHORE & SERN CHES BAY... M40S-L50S SERN VA/NC.

LOW PRESSURE PROGGED TO LIFT NE ALONG THE CAROLINA COAST MONDAY NIGHT
WITH STDYST PCPN ENDING SW-NE BY 06Z. SNDGS INDCTG ENUF MSTR FOR LGT
RAIN / DRIZZLE THRU THE OVRNITE HRS. TMPS STDY IN THE M30S NW TO M40S
SE. QPF 1/4 TO 1/2 IN.

MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION TUESDAY. HOWEVER...
MOIST EASTERLY FLOW WILL PREVAIL. KEPT LOW CHC (30%) POPS THRU THE
DAY ALTHROUGH SOME DRIZZLE MAY LINGER THROUGH THE MORNING HRS. BIG
TMP DIFFERENCES SEEN IN MOS DATA WHERE NAM IS SOME 5-10 DEGREES
COLDER THAN THE GFS. GIVEN MODELS MAINTAIN AN ERLY SFC FLOW...WILL
SPLIT THE DIFFERENCE FOR NOW AND GO WITH HIGHS FROM THE M-U40S OVR
THE PIEDMONT TO M-U50S CSTL AREAS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS AND LIGHT WINDS EXPECTED TO CONTINUE THROUGH THE
06Z TAF PERIOD. BKN-OVC CLOUDS BETWEEN 8-10K FT WILL SLOWLY ERODE
THROUGH LATE MORNING.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
N-NE WINDS AOB 10 KT WILL PREVAIL TODAY WITH HIGH PRESSURE IN PLACE.
WINDS TURN MORE EASTERLY TONIGHT AND INCREASE TO 10-15 KT MOST AREAS
AS LOW PRESSURE ORGANIZING OFF THE SOUTHEAST COAST SLOWLY PUSHES
NORTH. THE SFC LOW CONTINUES TO MOVE NORTHEAST OF THE NC COAST ON
MONDAY...BUT WEAKENS BY LATE MONDAY/MONDAY NIGHT. WINDS WILL GENERALLY
REMAIN E-NE AOB 15 KT ALL WATERS DURING THIS TIME...BUT TENDING TO
BECOME MORE NORTHERLY AOB 10 KT BY EARLY TUES MORNING. LATEST
GUIDANCE INDICATES POTENTIAL FOR SEAS TO BUILD TO AROUND 5 FT OUT 20
NM LATE MON/MON EVE ACROSS THE SOUTHERN COASTAL WATERS. CONFIDENCE
NOT HIGH ENOUGH TO ISSUE A 3RD PERIOD SCA ATTM.

LIGHT NW WINDS EXPECTED TUES AS HIGH PRESSURE REMAINS IN PLACE OVER
THE MID-ATLANTIC...AND THE NEXT LOW PRESSURE SYSTEM ORGANIZES OVER
THE DEEP SOUTH. WINDS TURN E-SE TUESDAY NIGHT AND GRADUALLY BEGIN TO
INCREASE AS A WARM FRONT LIFTS NORTH THROUGH THE AREA. A STRONG
COLD FRONT APPROACHES THE WATERS FROM THE WEST ON WEDNESDAY WITH
WINDS BECOMING SOUTHERLY AND INCREASING TO SCA THRESHOLDS (SAVE THE
RIVERS). THE FRONT QUICKLY SWEEPS THROUGH THE AREA WED NIGHT AND
OFFSHORE EARLY THURSDAY. WINDS REMAIN ABOVE SCA LEVELS THRU LATE
THURSDAY WHILE BECOMING SW THEN W. HIGH PRESSURE RETURNS THU NIGHT
INTO THE START OF NEXT WEEKEND FOR IMPROVED CONDITIONS. SEAS WILL
GENERALLY BUILD TO 5-7 FT ON WED BEFORE SUBSIDING AGAIN LATE THU.
WAVES WILL REACH 4 FT ON THE CHES BAY.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...MPR
LONG TERM...BMD
AVIATION...JDM
MARINE...JDM






000
FXUS61 KPBZ 210614 AAC
AFDPBZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PITTSBURGH PA
115 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL THROUGH MONDAY. EXPECT
INCREASING PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN
AND WIND CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH TODAY/...
OVERNIGHT PERIOD IN PRETTY GOOD SHAPE. WELL DEVELOPED SHORTWAVE
WILL RUSH THROUGH OVERNIGHT...MOISTURE IN THE UPPER LEVELS IS
AHEAD OF THE WAVE AND MOISTURE IN THE LOWER LEVELS IS PRETTY THIN
IN VERTICAL EXTENT. 00Z SOUNDINGS SHOW A VERY DRY LAYER BENEATH THE
STRATOCU WHICH SHOULD EVAPORATE MOST OF THE PRECIP THAT MAY BE
CREATED. HAVE REMOVED THE MENTION OF FLURRIES FOR THE OVERNIGHT...
ANYTHING THAT REACHES THE GROUND WILL BE ISOLATED AND VERY LIGHT.
TEMPS HAVE BEEN UPDATED TO LATEST GUIDANCE.

WEAK RIDGING ALOFT AND HIGH PRESSURE AT THE SURFACE WILL KEEP THE
REGION DRY TODAY. CLOUD COVER AGAIN WILL BE TRICKY. DRIER AIR...IN
THE STRATOCU LAYER...WILL SLOWLY MOVE NORTH AND EAST TODAY WITH
THE 850MB RIDGE. WILL CONTINUE WITH THE IDEA OF DECREASING CLOUDS...
WHICH WILL ALSO HELP TEMPS WARM.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
SURFACE HIGH WILL SLIDE EASTWARD TONIGHT...AS WILL THE UPPER LEVEL
RIDGE. WAA WILL GET STARTED MONDAY MORNING AND CONTINUE THROUGHOUT
THE DAY. THE WARMER AIR WILL ALSO PULL MOISTURE NORTHWARD...
INCREASING CLOUDS ONCE AGAIN. BIG QUESTION ON MONDAY IS THE OUTER
EDGE OF THE PRECIP SHIELD THAT IS ASSOCIATED WITH EASTERN SEABOARD
SYSTEM. IT APPEARS THAT SOME OF THIS PRECIP COULD CLIP THE
SOUTHEASTERN RIDGES ON MONDAY. THE PROBLEM WILL BE THE COLD AIR
TRAPPED IN THE RIDGES...THANKS TO THE LOW-LEVEL EASTERLY FLOW.
CONFIDENCE IS LOW HERE...AS MODELS HAVE BOUNCED BACK AND FORTH
WITH HOW FAR WEST TO SPREAD THE PRECIP. THERE IS VERY LITTLE UPPER
LEVEL SUPPORT THIS FAR WEST...BUT WITH THE EASTERLY FLOW...
SHOWERS MAY BE ABLE TO CLIP THE AFOREMENTIONED RIDGES. SURFACE
TEMPS WILL BE CRITICAL...BUT IT DOES APPEAR THAT AT LEAST THE
SHELTERED VALLEYS WILL BE ABLE TO HOLD ON TO TEMPS AT OR BELOW
FREEZING. WILL NEED TO INCLUDE THE MENTION OF FREEZING RAIN IN
THESE AREAS MONDAY.

LOW-LEVEL JET WILL GET STRONG WAA GOING MONDAY NIGHT AND TUESDAY.
STILL TOUGH TO GET A GOOD HANDLE ON HOW MUCH RAIN WILL REACH THE
REGION ON TUESDAY. THE UPPER LEVEL SUPPORT IS WEAK AND
UNORGANIZED...BUT THE LOW-LEVEL JET WILL PULL MOISTURE NORTHWARD
AS WELL. WILL INCREASE RAIN CHANCES FROM WEST TO EAST TUESDAY...BUT
KEEP EVERYTHING IN THE CHANCE CATEGORY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED...GIVEN
THE TIME PERIOD WHICH IT AFFECTS OUR AREA...IS STILL ON TRACK.
LONG RANGE ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE
CONVERGING ON A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.
THIS WILL MAKE FOR ALL LIQUID PRECIPITATION ON THE FRONT END.
TEMPERATURES WILL SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY
WITH 50S COMMON. COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF
MEXICO...SOUNDINGS ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES
TEMP DIFFERENTIAL BETWEEN H8 AND H5 TO NEARLY 0C. THIS COULD LEAD
TO ISOLATED THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE. FOR THE
TIME BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT
FOR BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT. DESPITE
PWATS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT. LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE
PROJECTED QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY. FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST. HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE
GROUND AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME. ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER. EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE. NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS. MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
MVFR CONDITIONS TO CONTINUE BEFORE LOWER LEVEL CLOUDS BEGIN TO
SCATTER OUT LATE THIS MORNING AS WINDS TRANSITION TO THE SOUTHWEST
AHEAD OF A LOW PRESSURE SYSTEM DEVELOPING OVER THE CENTRAL CONUS.

OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$










000
FXUS61 KPBZ 210614 AAC
AFDPBZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PITTSBURGH PA
115 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL THROUGH MONDAY. EXPECT
INCREASING PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN
AND WIND CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH TODAY/...
OVERNIGHT PERIOD IN PRETTY GOOD SHAPE. WELL DEVELOPED SHORTWAVE
WILL RUSH THROUGH OVERNIGHT...MOISTURE IN THE UPPER LEVELS IS
AHEAD OF THE WAVE AND MOISTURE IN THE LOWER LEVELS IS PRETTY THIN
IN VERTICAL EXTENT. 00Z SOUNDINGS SHOW A VERY DRY LAYER BENEATH THE
STRATOCU WHICH SHOULD EVAPORATE MOST OF THE PRECIP THAT MAY BE
CREATED. HAVE REMOVED THE MENTION OF FLURRIES FOR THE OVERNIGHT...
ANYTHING THAT REACHES THE GROUND WILL BE ISOLATED AND VERY LIGHT.
TEMPS HAVE BEEN UPDATED TO LATEST GUIDANCE.

WEAK RIDGING ALOFT AND HIGH PRESSURE AT THE SURFACE WILL KEEP THE
REGION DRY TODAY. CLOUD COVER AGAIN WILL BE TRICKY. DRIER AIR...IN
THE STRATOCU LAYER...WILL SLOWLY MOVE NORTH AND EAST TODAY WITH
THE 850MB RIDGE. WILL CONTINUE WITH THE IDEA OF DECREASING CLOUDS...
WHICH WILL ALSO HELP TEMPS WARM.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
SURFACE HIGH WILL SLIDE EASTWARD TONIGHT...AS WILL THE UPPER LEVEL
RIDGE. WAA WILL GET STARTED MONDAY MORNING AND CONTINUE THROUGHOUT
THE DAY. THE WARMER AIR WILL ALSO PULL MOISTURE NORTHWARD...
INCREASING CLOUDS ONCE AGAIN. BIG QUESTION ON MONDAY IS THE OUTER
EDGE OF THE PRECIP SHIELD THAT IS ASSOCIATED WITH EASTERN SEABOARD
SYSTEM. IT APPEARS THAT SOME OF THIS PRECIP COULD CLIP THE
SOUTHEASTERN RIDGES ON MONDAY. THE PROBLEM WILL BE THE COLD AIR
TRAPPED IN THE RIDGES...THANKS TO THE LOW-LEVEL EASTERLY FLOW.
CONFIDENCE IS LOW HERE...AS MODELS HAVE BOUNCED BACK AND FORTH
WITH HOW FAR WEST TO SPREAD THE PRECIP. THERE IS VERY LITTLE UPPER
LEVEL SUPPORT THIS FAR WEST...BUT WITH THE EASTERLY FLOW...
SHOWERS MAY BE ABLE TO CLIP THE AFOREMENTIONED RIDGES. SURFACE
TEMPS WILL BE CRITICAL...BUT IT DOES APPEAR THAT AT LEAST THE
SHELTERED VALLEYS WILL BE ABLE TO HOLD ON TO TEMPS AT OR BELOW
FREEZING. WILL NEED TO INCLUDE THE MENTION OF FREEZING RAIN IN
THESE AREAS MONDAY.

LOW-LEVEL JET WILL GET STRONG WAA GOING MONDAY NIGHT AND TUESDAY.
STILL TOUGH TO GET A GOOD HANDLE ON HOW MUCH RAIN WILL REACH THE
REGION ON TUESDAY. THE UPPER LEVEL SUPPORT IS WEAK AND
UNORGANIZED...BUT THE LOW-LEVEL JET WILL PULL MOISTURE NORTHWARD
AS WELL. WILL INCREASE RAIN CHANCES FROM WEST TO EAST TUESDAY...BUT
KEEP EVERYTHING IN THE CHANCE CATEGORY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED...GIVEN
THE TIME PERIOD WHICH IT AFFECTS OUR AREA...IS STILL ON TRACK.
LONG RANGE ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE
CONVERGING ON A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.
THIS WILL MAKE FOR ALL LIQUID PRECIPITATION ON THE FRONT END.
TEMPERATURES WILL SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY
WITH 50S COMMON. COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF
MEXICO...SOUNDINGS ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES
TEMP DIFFERENTIAL BETWEEN H8 AND H5 TO NEARLY 0C. THIS COULD LEAD
TO ISOLATED THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE. FOR THE
TIME BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT
FOR BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT. DESPITE
PWATS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT. LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE
PROJECTED QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY. FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST. HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE
GROUND AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME. ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER. EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE. NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS. MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
MVFR CONDITIONS TO CONTINUE BEFORE LOWER LEVEL CLOUDS BEGIN TO
SCATTER OUT LATE THIS MORNING AS WINDS TRANSITION TO THE SOUTHWEST
AHEAD OF A LOW PRESSURE SYSTEM DEVELOPING OVER THE CENTRAL CONUS.

OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$









000
FXUS61 KAKQ 210545
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1245 AM EST SUN DEC 21 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL PUSH OFF THE SOUTHEAST COAST TONIGHT...AS HIGH
PRESSURE REMAINS OVER THE LOCAL AREA THROUGH SUNDAY EVENING. ANOTHER
LOW PRESSURE AREA MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP
ALONG THE CAROLINA COAST LATE MONDAY INTO TUESDAY...AS HIGH PRESSURE
DRIFTS OFF THE NEW ENGLAND COAST INTO THE CANADIAN MARITIMES. A COLD
FRONT WILL CROSS THE WEDNESDAY NIGHT WITH HIGH PRESSURE RETURNING
BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH TODAY/...
WIDESPREAD BKN-OVC CIGS MNLY 6-9KFT CONTG OVR THE FA ATTM...AND
W/O ANY DRYING NOTED ON THE SATELLITE...XPCD TO RMN OVR THE FA
THROUGH THE NGT. NUDGED TEMPS UP A FEW DEGS F MOST PLACES DUE TO
THE CLDNS. COLDEST SPOTS RIGHT NOW ON THE ERN SHORE. MOST LO TEMPS
FM THE M/U20S TO L30S.

HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. LIGHT WINDS OVERALL WITH A LIGHT ONSHORE
NE FLOW OVER THE SE COASTAL ZONES...SEASONABLE HIGHS IN THE LOWER-
MID 40S NE TO AROUND 50 F IN SOUTH CENTRAL VA.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
MODELS SHOW NEXT SHORTWAVE TROUGH AMPLIFYING ACRS THE NORTHERN
PLAINS SUN NIGHT/MON...AS STRONG UPPER LEVEL RIDGING HOLDS STRONG
FROM FLORIDA TO THE CARIBBEAN. MID/UPPER LEVEL FLOW PROGGED TO
TURN MORE SW AND THIS WILL HELP STEER LOW PRESSURE NE FROM THE
GULF COAST STATES INTO THE SE AND MID ATLC COASTAL WATERS MON/MON
NIGHT. POSITION OF SFC HIGH TO OUR N...SHIFTING EAST TO THE NEW
ENGLAND COAST BY 12Z/MON IS NOT FAVORABLE FOR LOCKING COLD AIR
OVER THE AKQ CWA. STILL SHOULD SEE ENOUGH COLD AIR INITIALLY OVER
THE REGION SUN NIGHT/MON MORNING DUE TO CLEAR SKIES THROUGH PART
OF THE NIGHT. THIS WILL LEAD TO THE CHC OF A FEW HRS WORTH OF
OVERRUNNING FROZEN PRECIP OVER CLIMO FAVORED PIEDMONT ZONES NW OF
RICHMOND (WITH LITTLE CHC FOR ANYTHING BUT ALL RAIN OVER THE REST
OF THE CWA). LOW LEVEL THICKNESSES (1000-850MB) ARE MARGINAL BUT
BUFKIT SOUNDINGS SHOW A NARROW LAYER OF BELOW FREEZING TEMPS AT
THE SFC FROM ABOUT 09-15Z/MON AT KCHO (AND LIKELY AT KLKU). STILL
SOME QUESTION AS TO HOW FAST PRECIP ARRIVES BUT OVERALL LOOKS LIKE
CHANCES RAMP UP SIGNIFICANTLY DURING THE 09-12Z TIMEFRAME. WILL GO
WITH A CHC FOR SLEET OVER THE PIEDMONT BETWEEN
09-12Z...TRANSITIONING TO SLEET/FREEZING RAIN FROM ABOUT
12-15Z/MON (ALTHOUGH BECOMING CONFINED TO THE FAR NW BY THIS
POINT). IN ANY EVENT...THIS LOOKS LIGHT AS BULK OF DEEPER MOISTURE
LIKELY ARRIVES AFTER A CHANGEOVER TO ALL RAIN. ALSO...NOT
ANTICIPATING TEMPS IN MID 20S...GENLY CLOSER TO 30-32 F...SO
IMPACTS ARE EXPECTED TO BE MINIMAL FOR THE MOST PART.

HIGHS MON ONLY IN THE UPPER 30S/AROUND 40 NW TO THE MID 50S FAR SE IN
CAD SETUP. MAINTAINING LIKELY TO CATEGORICAL POPS THROUGH MON
AFTN...ALTHOUGH QPF AMOUNTS ONLY AVG 0.25-0.50". LOW PRESSURE
LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING FROM
SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION
TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM THE GULF
STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE MAINTAINED.
HIGHS IN THE LOW 60S FAR SE TO THE UPPER 40S NW.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS AND LIGHT WINDS EXPECTED TO CONTINUE THROUGH THE
06Z TAF PERIOD. BKN-OVC CLOUDS BETWEEN 8-10K FT WILL SLOWLY ERODE
THROUGH LATE MORNING.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
QUIET/BENIGN CONDITIONS EXPECTED ACROSS ALL WATERS TONIGHT THROUGH
MOST OF SUNDAY NIGHT AS WEAK HIGH PRESSURE RIDGING RESIDES OVER THE
MID ATLANTIC REGION. WINDS WILL GENERALLY BE NORTH 5-10KT WITH
WAVES/SEAS AVERAGING 1-2FT. MEANWHILE...LOW PRESSURE CURRENTLY
STALLED OFF THE SE COAST GETS ABSORBED INTO ANOTHER LOW PRESSURE
SYSTEM TRACKING NE OUT OF THE NERN GULF OF MEXICO TO JUST OFF THE SE
COAST TONIGHT (RIDING ALONG THE BOUNDARY LEFT BY THE CURRENT SE
COAST LOW). THE NEWLY FORMED SE COAST LOW SLOWLY MOVES UP THE
CAROLINA COAST ON MON AND THE MID ATLANTIC COAST MON NIGHT...WASHING
OUT ON TUE/TUE NIGHT AS A VERY STRONG AND VIGOROUS SFC LOW DEEPENS
OVER THE OHIO VALLEY/GREAT LAKES REGIONS AND PUSHES A STRONG COLD
FRONT TWD THE AREA. WINDS TURN TO THE NE SUN NIGHT AND GRADUALLY
INCREASE TO 15-20KT FROM SOUTH TO NORTH ON MON. LOW-END SCA
CONDITIONS ARE ANTICIPATED TO DEVELOP BY MON AFTN AND PERSIST OVER
SRN WATERS THROUGH EARLY MON EVENING...AND OVER NRN WATERS THROUGH
LATE MON EVENING.

A BRIEF REPRIEVE IN SCA CONDITIONS IS EXPECTED TUE/TUE NIGHT AS THE
COASTAL LOW GETS WASHED OUT OVER THE MID ATLANTIC REGION. A WARM
FRONT LIFTS NORTH ACROSS THE WATERS ON WED AS A VERY STRONG COLD
FRONT APPROACHES THE REGION FROM THE WEST. THE SFC PRESSURE GRADIENT
TIGHTENS SIGNIFICANTLY ON WED AS A STRONG JET STREAK (90-150KT) ALSO
NOSES INTO THE REGION FROM THE SSW. SOUTH WINDS WILL INCREASE TO
SPEEDS OF 15-25KT IN THE SRN WATERS DURING THE MORNING AND IN THE
NRN WATERS BY THE AFTN WITH SCA CONDITIONS LIKELY DEVELOPING DURING
THE AFOREMENTIONED TIMEFRAMES. SEAS SHOULD RESPOND TO THE SLY WINDS
PRIOR TO SEEING THE INCREASED WIND SPEEDS WITH SEAS BUILDING FROM
2-4FT TUE NIGHT TO 4-5FT BY WED MORNING. WAVES WILL BUILD TO 3-4FT
ON CHES BAY ON WED. THE COLD FRONT IS EXPECTED TO CROSS THE WATERS
WED EVENING AND SOLID SCA CONDITIONS WILL LIKELY OCCUR AHEAD OF AND
BEHIND ITS PASSAGE. AM NOT ANTICIPATING GALE FORCE GUSTS UNLESS THEY
ARE ASSOCIATED WITH CONVECTIVE SHOWERS WED AFTN/EVENING. SEAS
CONTINUE TO BUILD TO 5-9FT WED NIGHT THROUGH THU BEFORE STARTING TO
SUBSIDE. S-SW WINDS OF 20-30KT WED NIGHT BECOME WLY ON
THU...REMAINING STRONG THROUGH THE DAY THU. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL BRING A RETURN TO BREEZY NW WINDS ACROSS THE WATERS LATE SAT
NIGHT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB/LKB
SHORT TERM...JDM/LKB
LONG TERM...BMD
AVIATION...JDM/LSA
MARINE...BMD







000
FXUS61 KAKQ 210545
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1245 AM EST SUN DEC 21 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL PUSH OFF THE SOUTHEAST COAST TONIGHT...AS HIGH
PRESSURE REMAINS OVER THE LOCAL AREA THROUGH SUNDAY EVENING. ANOTHER
LOW PRESSURE AREA MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP
ALONG THE CAROLINA COAST LATE MONDAY INTO TUESDAY...AS HIGH PRESSURE
DRIFTS OFF THE NEW ENGLAND COAST INTO THE CANADIAN MARITIMES. A COLD
FRONT WILL CROSS THE WEDNESDAY NIGHT WITH HIGH PRESSURE RETURNING
BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH TODAY/...
WIDESPREAD BKN-OVC CIGS MNLY 6-9KFT CONTG OVR THE FA ATTM...AND
W/O ANY DRYING NOTED ON THE SATELLITE...XPCD TO RMN OVR THE FA
THROUGH THE NGT. NUDGED TEMPS UP A FEW DEGS F MOST PLACES DUE TO
THE CLDNS. COLDEST SPOTS RIGHT NOW ON THE ERN SHORE. MOST LO TEMPS
FM THE M/U20S TO L30S.

HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. LIGHT WINDS OVERALL WITH A LIGHT ONSHORE
NE FLOW OVER THE SE COASTAL ZONES...SEASONABLE HIGHS IN THE LOWER-
MID 40S NE TO AROUND 50 F IN SOUTH CENTRAL VA.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
MODELS SHOW NEXT SHORTWAVE TROUGH AMPLIFYING ACRS THE NORTHERN
PLAINS SUN NIGHT/MON...AS STRONG UPPER LEVEL RIDGING HOLDS STRONG
FROM FLORIDA TO THE CARIBBEAN. MID/UPPER LEVEL FLOW PROGGED TO
TURN MORE SW AND THIS WILL HELP STEER LOW PRESSURE NE FROM THE
GULF COAST STATES INTO THE SE AND MID ATLC COASTAL WATERS MON/MON
NIGHT. POSITION OF SFC HIGH TO OUR N...SHIFTING EAST TO THE NEW
ENGLAND COAST BY 12Z/MON IS NOT FAVORABLE FOR LOCKING COLD AIR
OVER THE AKQ CWA. STILL SHOULD SEE ENOUGH COLD AIR INITIALLY OVER
THE REGION SUN NIGHT/MON MORNING DUE TO CLEAR SKIES THROUGH PART
OF THE NIGHT. THIS WILL LEAD TO THE CHC OF A FEW HRS WORTH OF
OVERRUNNING FROZEN PRECIP OVER CLIMO FAVORED PIEDMONT ZONES NW OF
RICHMOND (WITH LITTLE CHC FOR ANYTHING BUT ALL RAIN OVER THE REST
OF THE CWA). LOW LEVEL THICKNESSES (1000-850MB) ARE MARGINAL BUT
BUFKIT SOUNDINGS SHOW A NARROW LAYER OF BELOW FREEZING TEMPS AT
THE SFC FROM ABOUT 09-15Z/MON AT KCHO (AND LIKELY AT KLKU). STILL
SOME QUESTION AS TO HOW FAST PRECIP ARRIVES BUT OVERALL LOOKS LIKE
CHANCES RAMP UP SIGNIFICANTLY DURING THE 09-12Z TIMEFRAME. WILL GO
WITH A CHC FOR SLEET OVER THE PIEDMONT BETWEEN
09-12Z...TRANSITIONING TO SLEET/FREEZING RAIN FROM ABOUT
12-15Z/MON (ALTHOUGH BECOMING CONFINED TO THE FAR NW BY THIS
POINT). IN ANY EVENT...THIS LOOKS LIGHT AS BULK OF DEEPER MOISTURE
LIKELY ARRIVES AFTER A CHANGEOVER TO ALL RAIN. ALSO...NOT
ANTICIPATING TEMPS IN MID 20S...GENLY CLOSER TO 30-32 F...SO
IMPACTS ARE EXPECTED TO BE MINIMAL FOR THE MOST PART.

HIGHS MON ONLY IN THE UPPER 30S/AROUND 40 NW TO THE MID 50S FAR SE IN
CAD SETUP. MAINTAINING LIKELY TO CATEGORICAL POPS THROUGH MON
AFTN...ALTHOUGH QPF AMOUNTS ONLY AVG 0.25-0.50". LOW PRESSURE
LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING FROM
SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION
TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM THE GULF
STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE MAINTAINED.
HIGHS IN THE LOW 60S FAR SE TO THE UPPER 40S NW.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS AND LIGHT WINDS EXPECTED TO CONTINUE THROUGH THE
06Z TAF PERIOD. BKN-OVC CLOUDS BETWEEN 8-10K FT WILL SLOWLY ERODE
THROUGH LATE MORNING.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
QUIET/BENIGN CONDITIONS EXPECTED ACROSS ALL WATERS TONIGHT THROUGH
MOST OF SUNDAY NIGHT AS WEAK HIGH PRESSURE RIDGING RESIDES OVER THE
MID ATLANTIC REGION. WINDS WILL GENERALLY BE NORTH 5-10KT WITH
WAVES/SEAS AVERAGING 1-2FT. MEANWHILE...LOW PRESSURE CURRENTLY
STALLED OFF THE SE COAST GETS ABSORBED INTO ANOTHER LOW PRESSURE
SYSTEM TRACKING NE OUT OF THE NERN GULF OF MEXICO TO JUST OFF THE SE
COAST TONIGHT (RIDING ALONG THE BOUNDARY LEFT BY THE CURRENT SE
COAST LOW). THE NEWLY FORMED SE COAST LOW SLOWLY MOVES UP THE
CAROLINA COAST ON MON AND THE MID ATLANTIC COAST MON NIGHT...WASHING
OUT ON TUE/TUE NIGHT AS A VERY STRONG AND VIGOROUS SFC LOW DEEPENS
OVER THE OHIO VALLEY/GREAT LAKES REGIONS AND PUSHES A STRONG COLD
FRONT TWD THE AREA. WINDS TURN TO THE NE SUN NIGHT AND GRADUALLY
INCREASE TO 15-20KT FROM SOUTH TO NORTH ON MON. LOW-END SCA
CONDITIONS ARE ANTICIPATED TO DEVELOP BY MON AFTN AND PERSIST OVER
SRN WATERS THROUGH EARLY MON EVENING...AND OVER NRN WATERS THROUGH
LATE MON EVENING.

A BRIEF REPRIEVE IN SCA CONDITIONS IS EXPECTED TUE/TUE NIGHT AS THE
COASTAL LOW GETS WASHED OUT OVER THE MID ATLANTIC REGION. A WARM
FRONT LIFTS NORTH ACROSS THE WATERS ON WED AS A VERY STRONG COLD
FRONT APPROACHES THE REGION FROM THE WEST. THE SFC PRESSURE GRADIENT
TIGHTENS SIGNIFICANTLY ON WED AS A STRONG JET STREAK (90-150KT) ALSO
NOSES INTO THE REGION FROM THE SSW. SOUTH WINDS WILL INCREASE TO
SPEEDS OF 15-25KT IN THE SRN WATERS DURING THE MORNING AND IN THE
NRN WATERS BY THE AFTN WITH SCA CONDITIONS LIKELY DEVELOPING DURING
THE AFOREMENTIONED TIMEFRAMES. SEAS SHOULD RESPOND TO THE SLY WINDS
PRIOR TO SEEING THE INCREASED WIND SPEEDS WITH SEAS BUILDING FROM
2-4FT TUE NIGHT TO 4-5FT BY WED MORNING. WAVES WILL BUILD TO 3-4FT
ON CHES BAY ON WED. THE COLD FRONT IS EXPECTED TO CROSS THE WATERS
WED EVENING AND SOLID SCA CONDITIONS WILL LIKELY OCCUR AHEAD OF AND
BEHIND ITS PASSAGE. AM NOT ANTICIPATING GALE FORCE GUSTS UNLESS THEY
ARE ASSOCIATED WITH CONVECTIVE SHOWERS WED AFTN/EVENING. SEAS
CONTINUE TO BUILD TO 5-9FT WED NIGHT THROUGH THU BEFORE STARTING TO
SUBSIDE. S-SW WINDS OF 20-30KT WED NIGHT BECOME WLY ON
THU...REMAINING STRONG THROUGH THE DAY THU. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL BRING A RETURN TO BREEZY NW WINDS ACROSS THE WATERS LATE SAT
NIGHT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB/LKB
SHORT TERM...JDM/LKB
LONG TERM...BMD
AVIATION...JDM/LSA
MARINE...BMD






000
FXUS61 KPBZ 210535 AAC
AFDPBZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PITTSBURGH PA
1235 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL THROUGH MONDAY. EXPECT
INCREASING PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN
AND WIND CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH TODAY/...
OVERNIGHT PERIOD IN PRETTY GOOD SHAPE. WELL DEVELOPED SHORTWAVE
WILL RUSH THROUGH OVERNIGHT...MOISTURE IN THE UPPER LEVELS IS
AHEAD OF THE WAVE AND MOISTURE IN THE LOWER LEVELS IS PRETTY THIN
IN VERTICAL EXTENT. 00Z SOUNDINGS SHOW A VERY DRY LAYER BENEATH THE
STRATOCU WHICH SHOULD EVAPORATE MOST OF THE PRECIP THAT MAY BE
CREATED. HAVE REMOVED THE MENTION OF FLURRIES FOR THE OVERNIGHT...
ANYTHING THAT REACHES THE GROUND WILL BE ISOLATED AND VERY LIGHT.
TEMPS HAVE BEEN UPDATED TO LATEST GUIDANCE.

WEAK RIDGING ALOFT AND HIGH PRESSURE AT THE SURFACE WILL KEEP THE
REGION DRY TODAY. CLOUD COVER AGAIN WILL BE TRICKY. DRIER AIR...IN
THE STRATOCU LAYER...WILL SLOWLY MOVE NORTH AND EAST TODAY WITH
THE 850MB RIDGE. WILL CONTINUE WITH THE IDEA OF DECREASING CLOUDS...
WHICH WILL ALSO HELP TEMPS WARM.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
SURFACE HIGH WILL SLIDE EASTWARD TONIGHT...AS WILL THE UPPER LEVEL
RIDGE. WAA WILL GET STARTED MONDAY MORNING AND CONTINUE THROUGHOUT
THE DAY. THE WARMER AIR WILL ALSO PULL MOISTURE NORTHWARD...
INCREASING CLOUDS ONCE AGAIN. BIG QUESTION ON MONDAY IS THE OUTER
EDGE OF THE PRECIP SHIELD THAT IS ASSOCIATED WITH EASTERN SEABOARD
SYSTEM. IT APPEARS THAT SOME OF THIS PRECIP COULD CLIP THE
SOUTHEASTERN RIDGES ON MONDAY. THE PROBLEM WILL BE THE COLD AIR
TRAPPED IN THE RIDGES...THANKS TO THE LOW-LEVEL EASTERLY FLOW.
CONFIDENCE IS LOW HERE...AS MODELS HAVE BOUNCED BACK AND FORTH
WITH HOW FAR WEST TO SPREAD THE PRECIP. THERE IS VERY LITTLE UPPER
LEVEL SUPPORT THIS FAR WEST...BUT WITH THE EASTERLY FLOW...
SHOWERS MAY BE ABLE TO CLIP THE AFOREMENTIONED RIDGES. SURFACE
TEMPS WILL BE CRITICAL...BUT IT DOES APPEAR THAT AT LEAST THE
SHELTERED VALLEYS WILL BE ABLE TO HOLD ON TO TEMPS AT OR BELOW
FREEZING. WILL NEED TO INCLUDE THE MENTION OF FREEZING RAIN IN
THESE AREAS MONDAY.

LOW-LEVEL JET WILL GET STRONG WAA GOING MONDAY NIGHT AND TUESDAY.
STILL TOUGH TO GET A GOOD HANDLE ON HOW MUCH RAIN WILL REACH THE
REGION ON TUESDAY. THE UPPER LEVEL SUPPORT IS WEAK AND
UNORGANIZED...BUT THE LOW-LEVEL JET WILL PULL MOISTURE NORTHWARD
AS WELL. WILL INCREASE RAIN CHANCES FROM WEST TO EAST TUESDAY...BUT
KEEP EVERYTHING IN THE CHANCE CATEGORY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED...GIVEN
THE TIME PERIOD WHICH IT AFFECTS OUR AREA...IS STILL ON TRACK.
LONG RANGE ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE
CONVERGING ON A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.
THIS WILL MAKE FOR ALL LIQUID PRECIPITATION ON THE FRONT END.
TEMPERATURES WILL SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY
WITH 50S COMMON. COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF
MEXICO...SOUNDINGS ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES
TEMP DIFFERENTIAL BETWEEN H8 AND H5 TO NEARLY 0C. THIS COULD LEAD
TO ISOLATED THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE. FOR THE
TIME BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT
FOR BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT. DESPITE
PWATS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT. LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE
PROJECTED QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY. FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST. HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE
GROUND AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME. ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER. EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE. NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS. MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
WHILE FKL...DUJ...AND ZZV ARE EXPECTED TO REMAIN UNDER MVFR CIGS
OVERNIGHT...REMAINING TERMINALS MAY CONTINUE TO HAVE LOWER CLOUDS
SCATTER OUT LEAVING A MID DECK TEMPORARILY. BY MIDNIGHT ALL
TERMINALS ARE EXPECTED TO RETURN TO UNIFORM MVFR CIGS. CANNOT RULE
OUT SOME CIGS BELOW 2KFT BUT DID NOT HAVE CONFIDENCE TO INCLUDE
THEM. UNCERTAINTY REMAINS AS TO WHEN SKIES SHOULD SCATTER OUT ON
SUNDAY. THE SCATTERING TREND SHOULD MOVE FROM SOUTHWEST TO
NORTHEAST...BUT CURRENT FORECAST DOES NOT ELIMINATE CIG FROM
PITTSBURGH AND LOCATIONS NORTHEAST UNTIL 00Z MONDAY.


OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$







000
FXUS61 KPBZ 210535 AAC
AFDPBZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PITTSBURGH PA
1235 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL THROUGH MONDAY. EXPECT
INCREASING PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN
AND WIND CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH TODAY/...
OVERNIGHT PERIOD IN PRETTY GOOD SHAPE. WELL DEVELOPED SHORTWAVE
WILL RUSH THROUGH OVERNIGHT...MOISTURE IN THE UPPER LEVELS IS
AHEAD OF THE WAVE AND MOISTURE IN THE LOWER LEVELS IS PRETTY THIN
IN VERTICAL EXTENT. 00Z SOUNDINGS SHOW A VERY DRY LAYER BENEATH THE
STRATOCU WHICH SHOULD EVAPORATE MOST OF THE PRECIP THAT MAY BE
CREATED. HAVE REMOVED THE MENTION OF FLURRIES FOR THE OVERNIGHT...
ANYTHING THAT REACHES THE GROUND WILL BE ISOLATED AND VERY LIGHT.
TEMPS HAVE BEEN UPDATED TO LATEST GUIDANCE.

WEAK RIDGING ALOFT AND HIGH PRESSURE AT THE SURFACE WILL KEEP THE
REGION DRY TODAY. CLOUD COVER AGAIN WILL BE TRICKY. DRIER AIR...IN
THE STRATOCU LAYER...WILL SLOWLY MOVE NORTH AND EAST TODAY WITH
THE 850MB RIDGE. WILL CONTINUE WITH THE IDEA OF DECREASING CLOUDS...
WHICH WILL ALSO HELP TEMPS WARM.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
SURFACE HIGH WILL SLIDE EASTWARD TONIGHT...AS WILL THE UPPER LEVEL
RIDGE. WAA WILL GET STARTED MONDAY MORNING AND CONTINUE THROUGHOUT
THE DAY. THE WARMER AIR WILL ALSO PULL MOISTURE NORTHWARD...
INCREASING CLOUDS ONCE AGAIN. BIG QUESTION ON MONDAY IS THE OUTER
EDGE OF THE PRECIP SHIELD THAT IS ASSOCIATED WITH EASTERN SEABOARD
SYSTEM. IT APPEARS THAT SOME OF THIS PRECIP COULD CLIP THE
SOUTHEASTERN RIDGES ON MONDAY. THE PROBLEM WILL BE THE COLD AIR
TRAPPED IN THE RIDGES...THANKS TO THE LOW-LEVEL EASTERLY FLOW.
CONFIDENCE IS LOW HERE...AS MODELS HAVE BOUNCED BACK AND FORTH
WITH HOW FAR WEST TO SPREAD THE PRECIP. THERE IS VERY LITTLE UPPER
LEVEL SUPPORT THIS FAR WEST...BUT WITH THE EASTERLY FLOW...
SHOWERS MAY BE ABLE TO CLIP THE AFOREMENTIONED RIDGES. SURFACE
TEMPS WILL BE CRITICAL...BUT IT DOES APPEAR THAT AT LEAST THE
SHELTERED VALLEYS WILL BE ABLE TO HOLD ON TO TEMPS AT OR BELOW
FREEZING. WILL NEED TO INCLUDE THE MENTION OF FREEZING RAIN IN
THESE AREAS MONDAY.

LOW-LEVEL JET WILL GET STRONG WAA GOING MONDAY NIGHT AND TUESDAY.
STILL TOUGH TO GET A GOOD HANDLE ON HOW MUCH RAIN WILL REACH THE
REGION ON TUESDAY. THE UPPER LEVEL SUPPORT IS WEAK AND
UNORGANIZED...BUT THE LOW-LEVEL JET WILL PULL MOISTURE NORTHWARD
AS WELL. WILL INCREASE RAIN CHANCES FROM WEST TO EAST TUESDAY...BUT
KEEP EVERYTHING IN THE CHANCE CATEGORY.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED...GIVEN
THE TIME PERIOD WHICH IT AFFECTS OUR AREA...IS STILL ON TRACK.
LONG RANGE ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE
CONVERGING ON A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.
THIS WILL MAKE FOR ALL LIQUID PRECIPITATION ON THE FRONT END.
TEMPERATURES WILL SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY
WITH 50S COMMON. COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF
MEXICO...SOUNDINGS ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES
TEMP DIFFERENTIAL BETWEEN H8 AND H5 TO NEARLY 0C. THIS COULD LEAD
TO ISOLATED THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE. FOR THE
TIME BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT
FOR BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT. DESPITE
PWATS NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT. LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE
PROJECTED QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY. FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST. HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE
GROUND AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME. ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER. EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE. NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS. MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
WHILE FKL...DUJ...AND ZZV ARE EXPECTED TO REMAIN UNDER MVFR CIGS
OVERNIGHT...REMAINING TERMINALS MAY CONTINUE TO HAVE LOWER CLOUDS
SCATTER OUT LEAVING A MID DECK TEMPORARILY. BY MIDNIGHT ALL
TERMINALS ARE EXPECTED TO RETURN TO UNIFORM MVFR CIGS. CANNOT RULE
OUT SOME CIGS BELOW 2KFT BUT DID NOT HAVE CONFIDENCE TO INCLUDE
THEM. UNCERTAINTY REMAINS AS TO WHEN SKIES SHOULD SCATTER OUT ON
SUNDAY. THE SCATTERING TREND SHOULD MOVE FROM SOUTHWEST TO
NORTHEAST...BUT CURRENT FORECAST DOES NOT ELIMINATE CIG FROM
PITTSBURGH AND LOCATIONS NORTHEAST UNTIL 00Z MONDAY.


OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$






000
FXUS61 KAKQ 210251
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
951 PM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL PUSH OFF THE SOUTHEAST COAST TONIGHT...AS HIGH
PRESSURE REMAINS OVER THE LOCAL AREA THROUGH SUNDAY EVENING. ANOTHER
LOW PRESSURE AREA MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP
ALONG THE CAROLINA COAST LATE MONDAY INTO TUESDAY...AS HIGH PRESSURE
DRIFTS OFF THE NEW ENGLAND COAST INTO THE CANADIAN MARITIMES. A COLD
FRONT WILL CROSS THE WEDNESDAY NIGHT WITH HIGH PRESSURE RETURNING
BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
WIDESPREAD BKN-OVC CIGS MNLY 6-9KFT CONTG OVR THE FA ATTM...AND
W/O ANY DRYING NOTED ON THE SATELLITE...XPCD TO RMN OVR THE FA
THROUGH THE NGT. NUDGED TEMPS UP A FEW DEGS F MOST PLACES DUE TO
THE CLDNS. COLDEST SPOTS RIGHT NOW ON THE ERN SHORE. MOST LO TEMPS
FM THE M/U20S TO L30S.

HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. LIGHT WINDS OVERALL WITH A LIGHT ONSHORE
NE FLOW OVER THE SE COASTAL ZONES...SEASONABLE HIGHS IN THE LOWER-
MID 40S NE TO AROUND 50 F IN SOUTH CENTRAL VA.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
MODELS SHOW NEXT SHORTWAVE TROUGH AMPLIFYING ACRS THE NORTHERN
PLAINS SUN NIGHT/MON...AS STRONG UPPER LEVEL RIDGING HOLDS STRONG
FROM FLORIDA TO THE CARIBBEAN. MID/UPPER LEVEL FLOW PROGGED TO
TURN MORE SW AND THIS WILL HELP STEER LOW PRESSURE NE FROM THE
GULF COAST STATES INTO THE SE AND MID ATLC COASTAL WATERS MON/MON
NIGHT. POSITION OF SFC HIGH TO OUR N...SHIFTING EAST TO THE NEW
ENGLAND COAST BY 12Z/MON IS NOT FAVORABLE FOR LOCKING COLD AIR
OVER THE AKQ CWA. STILL SHOULD SEE ENOUGH COLD AIR INITIALLY OVER
THE REGION SUN NIGHT/MON MORNING DUE TO CLEAR SKIES THROUGH PART
OF THE NIGHT. THIS WILL LEAD TO THE CHC OF A FEW HRS WORTH OF
OVERRUNNING FROZEN PRECIP OVER CLIMO FAVORED PIEDMONT ZONES NW OF
RICHMOND (WITH LITTLE CHC FOR ANYTHING BUT ALL RAIN OVER THE REST
OF THE CWA). LOW LEVEL THICKNESSES (1000-850MB) ARE MARGINAL BUT
BUFKIT SOUNDINGS SHOW A NARROW LAYER OF BELOW FREEZING TEMPS AT
THE SFC FROM ABOUT 09-15Z/MON AT KCHO (AND LIKELY AT KLKU). STILL
SOME QUESTION AS TO HOW FAST PRECIP ARRIVES BUT OVERALL LOOKS LIKE
CHANCES RAMP UP SIGNIFICANTLY DURING THE 09-12Z TIMEFRAME. WILL GO
WITH A CHC FOR SLEET OVER THE PIEDMONT BETWEEN
09-12Z...TRANSITIONING TO SLEET/FREEZING RAIN FROM ABOUT
12-15Z/MON (ALTHOUGH BECOMING CONFINED TO THE FAR NW BY THIS
POINT). IN ANY EVENT...THIS LOOKS LIGHT AS BULK OF DEEPER MOISTURE
LIKELY ARRIVES AFTER A CHANGEOVER TO ALL RAIN. ALSO...NOT
ANTICIPATING TEMPS IN MID 20S...GENLY CLOSER TO 30-32 F...SO
IMPACTS ARE EXPECTED TO BE MINIMAL FOR THE MOST PART.

HIGHS MON ONLY IN THE UPPER 30S/AROUND 40 NW TO THE MID 50S FAR SE IN
CAD SETUP. MAINTAINING LIKELY TO CATEGORICAL POPS THROUGH MON
AFTN...ALTHOUGH QPF AMOUNTS ONLY AVG 0.25-0.50". LOW PRESSURE
LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING FROM
SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION
TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM THE GULF
STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE MAINTAINED.
HIGHS IN THE LOW 60S FAR SE TO THE UPPER 40S NW.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
NO PCPN IS EXPECTED DURING THE 00Z TAF PERIOD. BKN CLOUDS WERE OVER
MUCH OF THE AREA. MODEL SOUNDINGS INDICATED DRY AIR ABV 10K FT BUT
METARS HAVE BASES JUST BELOW THAT LEVEL. A THIN CLOUD DECK OF AROUND
8-10K FT IS EXPECTED TO DIMINISH TOWARD MORNING. SOME CLOUDS AT 5K
FT WERE REPORTED AT ECG. A MOSTLY CLEAR SKY IS FORECAST ON SUNDAY.
WINDS WILL BE LIGHT THROUGH THE PERIOD.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
QUIET/BENIGN CONDITIONS EXPECTED ACROSS ALL WATERS TONIGHT THROUGH
MOST OF SUNDAY NIGHT AS WEAK HIGH PRESSURE RIDGING RESIDES OVER THE
MID ATLANTIC REGION. WINDS WILL GENERALLY BE NORTH 5-10KT WITH
WAVES/SEAS AVERAGING 1-2FT. MEANWHILE...LOW PRESSURE CURRENTLY
STALLED OFF THE SE COAST GETS ABSORBED INTO ANOTHER LOW PRESSURE
SYSTEM TRACKING NE OUT OF THE NERN GULF OF MEXICO TO JUST OFF THE SE
COAST TONIGHT (RIDING ALONG THE BOUNDARY LEFT BY THE CURRENT SE
COAST LOW). THE NEWLY FORMED SE COAST LOW SLOWLY MOVES UP THE
CAROLINA COAST ON MON AND THE MID ATLANTIC COAST MON NIGHT...WASHING
OUT ON TUE/TUE NIGHT AS A VERY STRONG AND VIGOROUS SFC LOW DEEPENS
OVER THE OHIO VALLEY/GREAT LAKES REGIONS AND PUSHES A STRONG COLD
FRONT TWD THE AREA. WINDS TURN TO THE NE SUN NIGHT AND GRADUALLY
INCREASE TO 15-20KT FROM SOUTH TO NORTH ON MON. LOW-END SCA
CONDITIONS ARE ANTICIPATED TO DEVELOP BY MON AFTN AND PERSIST OVER
SRN WATERS THROUGH EARLY MON EVENING...AND OVER NRN WATERS THROUGH
LATE MON EVENING.

A BRIEF REPRIEVE IN SCA CONDITIONS IS EXPECTED TUE/TUE NIGHT AS THE
COASTAL LOW GETS WASHED OUT OVER THE MID ATLANTIC REGION. A WARM
FRONT LIFTS NORTH ACROSS THE WATERS ON WED AS A VERY STRONG COLD
FRONT APPROACHES THE REGION FROM THE WEST. THE SFC PRESSURE GRADIENT
TIGHTENS SIGNIFICANTLY ON WED AS A STRONG JET STREAK (90-150KT) ALSO
NOSES INTO THE REGION FROM THE SSW. SOUTH WINDS WILL INCREASE TO
SPEEDS OF 15-25KT IN THE SRN WATERS DURING THE MORNING AND IN THE
NRN WATERS BY THE AFTN WITH SCA CONDITIONS LIKELY DEVELOPING DURING
THE AFOREMENTIONED TIMEFRAMES. SEAS SHOULD RESPOND TO THE SLY WINDS
PRIOR TO SEEING THE INCREASED WIND SPEEDS WITH SEAS BUILDING FROM
2-4FT TUE NIGHT TO 4-5FT BY WED MORNING. WAVES WILL BUILD TO 3-4FT
ON CHES BAY ON WED. THE COLD FRONT IS EXPECTED TO CROSS THE WATERS
WED EVENING AND SOLID SCA CONDITIONS WILL LIKELY OCCUR AHEAD OF AND
BEHIND ITS PASSAGE. AM NOT ANTICIPATING GALE FORCE GUSTS UNLESS THEY
ARE ASSOCIATED WITH CONVECTIVE SHOWERS WED AFTN/EVENING. SEAS
CONTINUE TO BUILD TO 5-9FT WED NIGHT THROUGH THU BEFORE STARTING TO
SUBSIDE. S-SW WINDS OF 20-30KT WED NIGHT BECOME WLY ON
THU...REMAINING STRONG THROUGH THE DAY THU. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL BRING A RETURN TO BREEZY NW WINDS ACROSS THE WATERS LATE SAT
NIGHT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB/LKB
SHORT TERM...JDM/LKB
LONG TERM...BMD
AVIATION...LSA
MARINE...BMD







000
FXUS61 KAKQ 210251
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
951 PM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL PUSH OFF THE SOUTHEAST COAST TONIGHT...AS HIGH
PRESSURE REMAINS OVER THE LOCAL AREA THROUGH SUNDAY EVENING. ANOTHER
LOW PRESSURE AREA MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP
ALONG THE CAROLINA COAST LATE MONDAY INTO TUESDAY...AS HIGH PRESSURE
DRIFTS OFF THE NEW ENGLAND COAST INTO THE CANADIAN MARITIMES. A COLD
FRONT WILL CROSS THE WEDNESDAY NIGHT WITH HIGH PRESSURE RETURNING
BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
WIDESPREAD BKN-OVC CIGS MNLY 6-9KFT CONTG OVR THE FA ATTM...AND
W/O ANY DRYING NOTED ON THE SATELLITE...XPCD TO RMN OVR THE FA
THROUGH THE NGT. NUDGED TEMPS UP A FEW DEGS F MOST PLACES DUE TO
THE CLDNS. COLDEST SPOTS RIGHT NOW ON THE ERN SHORE. MOST LO TEMPS
FM THE M/U20S TO L30S.

HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. LIGHT WINDS OVERALL WITH A LIGHT ONSHORE
NE FLOW OVER THE SE COASTAL ZONES...SEASONABLE HIGHS IN THE LOWER-
MID 40S NE TO AROUND 50 F IN SOUTH CENTRAL VA.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
MODELS SHOW NEXT SHORTWAVE TROUGH AMPLIFYING ACRS THE NORTHERN
PLAINS SUN NIGHT/MON...AS STRONG UPPER LEVEL RIDGING HOLDS STRONG
FROM FLORIDA TO THE CARIBBEAN. MID/UPPER LEVEL FLOW PROGGED TO
TURN MORE SW AND THIS WILL HELP STEER LOW PRESSURE NE FROM THE
GULF COAST STATES INTO THE SE AND MID ATLC COASTAL WATERS MON/MON
NIGHT. POSITION OF SFC HIGH TO OUR N...SHIFTING EAST TO THE NEW
ENGLAND COAST BY 12Z/MON IS NOT FAVORABLE FOR LOCKING COLD AIR
OVER THE AKQ CWA. STILL SHOULD SEE ENOUGH COLD AIR INITIALLY OVER
THE REGION SUN NIGHT/MON MORNING DUE TO CLEAR SKIES THROUGH PART
OF THE NIGHT. THIS WILL LEAD TO THE CHC OF A FEW HRS WORTH OF
OVERRUNNING FROZEN PRECIP OVER CLIMO FAVORED PIEDMONT ZONES NW OF
RICHMOND (WITH LITTLE CHC FOR ANYTHING BUT ALL RAIN OVER THE REST
OF THE CWA). LOW LEVEL THICKNESSES (1000-850MB) ARE MARGINAL BUT
BUFKIT SOUNDINGS SHOW A NARROW LAYER OF BELOW FREEZING TEMPS AT
THE SFC FROM ABOUT 09-15Z/MON AT KCHO (AND LIKELY AT KLKU). STILL
SOME QUESTION AS TO HOW FAST PRECIP ARRIVES BUT OVERALL LOOKS LIKE
CHANCES RAMP UP SIGNIFICANTLY DURING THE 09-12Z TIMEFRAME. WILL GO
WITH A CHC FOR SLEET OVER THE PIEDMONT BETWEEN
09-12Z...TRANSITIONING TO SLEET/FREEZING RAIN FROM ABOUT
12-15Z/MON (ALTHOUGH BECOMING CONFINED TO THE FAR NW BY THIS
POINT). IN ANY EVENT...THIS LOOKS LIGHT AS BULK OF DEEPER MOISTURE
LIKELY ARRIVES AFTER A CHANGEOVER TO ALL RAIN. ALSO...NOT
ANTICIPATING TEMPS IN MID 20S...GENLY CLOSER TO 30-32 F...SO
IMPACTS ARE EXPECTED TO BE MINIMAL FOR THE MOST PART.

HIGHS MON ONLY IN THE UPPER 30S/AROUND 40 NW TO THE MID 50S FAR SE IN
CAD SETUP. MAINTAINING LIKELY TO CATEGORICAL POPS THROUGH MON
AFTN...ALTHOUGH QPF AMOUNTS ONLY AVG 0.25-0.50". LOW PRESSURE
LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING FROM
SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION
TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM THE GULF
STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE MAINTAINED.
HIGHS IN THE LOW 60S FAR SE TO THE UPPER 40S NW.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
NO PCPN IS EXPECTED DURING THE 00Z TAF PERIOD. BKN CLOUDS WERE OVER
MUCH OF THE AREA. MODEL SOUNDINGS INDICATED DRY AIR ABV 10K FT BUT
METARS HAVE BASES JUST BELOW THAT LEVEL. A THIN CLOUD DECK OF AROUND
8-10K FT IS EXPECTED TO DIMINISH TOWARD MORNING. SOME CLOUDS AT 5K
FT WERE REPORTED AT ECG. A MOSTLY CLEAR SKY IS FORECAST ON SUNDAY.
WINDS WILL BE LIGHT THROUGH THE PERIOD.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
QUIET/BENIGN CONDITIONS EXPECTED ACROSS ALL WATERS TONIGHT THROUGH
MOST OF SUNDAY NIGHT AS WEAK HIGH PRESSURE RIDGING RESIDES OVER THE
MID ATLANTIC REGION. WINDS WILL GENERALLY BE NORTH 5-10KT WITH
WAVES/SEAS AVERAGING 1-2FT. MEANWHILE...LOW PRESSURE CURRENTLY
STALLED OFF THE SE COAST GETS ABSORBED INTO ANOTHER LOW PRESSURE
SYSTEM TRACKING NE OUT OF THE NERN GULF OF MEXICO TO JUST OFF THE SE
COAST TONIGHT (RIDING ALONG THE BOUNDARY LEFT BY THE CURRENT SE
COAST LOW). THE NEWLY FORMED SE COAST LOW SLOWLY MOVES UP THE
CAROLINA COAST ON MON AND THE MID ATLANTIC COAST MON NIGHT...WASHING
OUT ON TUE/TUE NIGHT AS A VERY STRONG AND VIGOROUS SFC LOW DEEPENS
OVER THE OHIO VALLEY/GREAT LAKES REGIONS AND PUSHES A STRONG COLD
FRONT TWD THE AREA. WINDS TURN TO THE NE SUN NIGHT AND GRADUALLY
INCREASE TO 15-20KT FROM SOUTH TO NORTH ON MON. LOW-END SCA
CONDITIONS ARE ANTICIPATED TO DEVELOP BY MON AFTN AND PERSIST OVER
SRN WATERS THROUGH EARLY MON EVENING...AND OVER NRN WATERS THROUGH
LATE MON EVENING.

A BRIEF REPRIEVE IN SCA CONDITIONS IS EXPECTED TUE/TUE NIGHT AS THE
COASTAL LOW GETS WASHED OUT OVER THE MID ATLANTIC REGION. A WARM
FRONT LIFTS NORTH ACROSS THE WATERS ON WED AS A VERY STRONG COLD
FRONT APPROACHES THE REGION FROM THE WEST. THE SFC PRESSURE GRADIENT
TIGHTENS SIGNIFICANTLY ON WED AS A STRONG JET STREAK (90-150KT) ALSO
NOSES INTO THE REGION FROM THE SSW. SOUTH WINDS WILL INCREASE TO
SPEEDS OF 15-25KT IN THE SRN WATERS DURING THE MORNING AND IN THE
NRN WATERS BY THE AFTN WITH SCA CONDITIONS LIKELY DEVELOPING DURING
THE AFOREMENTIONED TIMEFRAMES. SEAS SHOULD RESPOND TO THE SLY WINDS
PRIOR TO SEEING THE INCREASED WIND SPEEDS WITH SEAS BUILDING FROM
2-4FT TUE NIGHT TO 4-5FT BY WED MORNING. WAVES WILL BUILD TO 3-4FT
ON CHES BAY ON WED. THE COLD FRONT IS EXPECTED TO CROSS THE WATERS
WED EVENING AND SOLID SCA CONDITIONS WILL LIKELY OCCUR AHEAD OF AND
BEHIND ITS PASSAGE. AM NOT ANTICIPATING GALE FORCE GUSTS UNLESS THEY
ARE ASSOCIATED WITH CONVECTIVE SHOWERS WED AFTN/EVENING. SEAS
CONTINUE TO BUILD TO 5-9FT WED NIGHT THROUGH THU BEFORE STARTING TO
SUBSIDE. S-SW WINDS OF 20-30KT WED NIGHT BECOME WLY ON
THU...REMAINING STRONG THROUGH THE DAY THU. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL BRING A RETURN TO BREEZY NW WINDS ACROSS THE WATERS LATE SAT
NIGHT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB/LKB
SHORT TERM...JDM/LKB
LONG TERM...BMD
AVIATION...LSA
MARINE...BMD








000
FXUS61 KPBZ 210217
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
917 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL INTO MONDAY. EXPECT INCREASING
PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN AND WIND
CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
PRIMARY CHANGE WITH 915PM UPDATE WAS TO ADD SCATTERED FLURRIES
FROM PITTSBURGH AND TO THE NORTH AND WEST. SOME LIGHT RADAR ECHOES
HAVE MOVED FROM INDIANA INTO OHIO DURING THE AFTERNOON AND EARLY
EVENING HOURS...WITH A COUPLE OF AUTOMATED STATIONS REPORTING
LIGHT SNOW. IN THE LAST HOUR THREE SITES AROUND COLUMBUS OHIO HAVE
REPORTED SNOW...AND EXPECT THAT THIS FLURRY ACTIVITY COULD
CONTINUE AS IT IS ASSOCIATED WITH AN UPPER LEVEL SHORTWAVE MOVING
THROUGH THE REGION. FLURRIES SHOULD COME TO AN END AFTER MIDNIGHT.
A SLIGHT CHANCE OF LIGHT SNOW STILL CANNOT BE RULED OUT SOUTH AND
EAST OF PITTSBURGH WITH ANOTHER FEATURE...BUT NO ACCUMULATIONS ARE
EXPECTED ANYWHERE OVERNIGHT.

INVERSION IS MAINTAINED SUNDAY MORNING WHICH WILL MAINTAIN STRATUS
DECK...BUT BY AFTERNOON EXPECT STRATUS TO MIX OUT INTO A CU FIELD
AND THEN SCATTER OUT BY EVENING. A BIT MORE SUN SHOULD ALLOW FOR
AFTERNOON HIGH TEMPS AROUND 5 DEGREES WARMER THAN TODAY. CL

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
BENIGN WEATHER INITIALLY WITH HIGH PRESSURE TO OUR EAST AND IN
CONTROL.  SOUTHEAST WINDS IN RESPONSE TO SURFACE ANTICYCLONE
POSITION WILL FACILITATE DEVELOPMENT OF STRATUS OVER EASTERN
PORTIONS OF TUCKER AND GARRETT COUNTIES MONDAY INTO MONDAY NIGHT.
PCPN ONSET HAS SLOWED DOWN FROM PREVIOUS CYCLES...BUT THERE REMAINS
A VERY LOW PROBABILITY OF FREEZING RAIN AND/OR SLEET OVER
AFOREMENTIONED AREAS MONDAY.  FOR NOW...TRENDED FORECAST WITH PCPN
COMMENCING DURING THE AFTERNOON WHICH REFLECT LATEST NUMERICAL
MODELS.  WITH THIS SCENARIO...LOW LEVEL SUB-FREEZING AIR SHOULD
SCOUR OUT YIELDING AN ALL RAIN PTYPE.

RAIN SHADOW EFFECT TAKES PLACES TUESDAY WITH SOUTHEAST WINDS
WIDESPREAD OVER THE REGION. AN ISOLATED SHOWER REACHING EASTERN OHIO
AND FAR NWRN PA IS NOT OUT OF THE QUESTION...SO KEPT A SLIGHT
CHANCE.  WOULD NOT BE SURPRISED TO SEE BREAKS IN THE CLOUDS WHICH
COULD ALLOW FOR A FEW LOCATIONS TO EXCEED 60 DEGREES.  RECORD HIGHS
FOR PITTSBURGH...MORGANTOWN...AND ZANESVILLE ALL RESIDE WELL INTO
THE UPPER 60S...SO AT THIS JUNCTURE RECORD WARMTH IS NOT FORESEEN.
PRECIP ASSOCIATED WITH THE SURFACE LOW PRESSURE SYSTEM EJECTING FROM
THE GULF COAST REGION REACHES SERN AREAS OF THE FORECAST AREA THAT
EVENING.

A BLEND OF THE ONGOING FORECAST AND BIAS CORRECTED ECMWF WERE USED
FOR TEMPERATURES.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED GIVEN THE
TIME PERIOD WHICH IT AFFECTS OUR AREA IS STILL ON TRACK.  LONG RANGE
ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE CONVERGING ON
A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.  THIS WILL MAKE
FOR ALL LIQUID PRECIPITATION ON THE FRONT END.  TEMPERATURES WILL
SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY WITH 50S COMMON.
COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF MEXICO...SOUNDINGS
ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES TEMP DIFFERENTIAL
BETWEEN H8 AND H5 TO NEARLY 0C.  THIS COULD LEAD TO ISOLATED
THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE.  FOR THE TIME
BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT FOR
BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT.  DESPITE PWATS
NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT.  LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE PROJECTED
QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY.  FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST.  HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE GROUND
AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME.  ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER.  EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE.  NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS.  MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
WHILE FKL...DUJ...AND ZZV ARE EXPECTED TO REMAIN UNDER MVFR CIGS
OVERNIGHT...REMAINING TERMINALS MAY CONTINUE TO HAVE LOWER CLOUDS
SCATTER OUT LEAVING A MID DECK TEMPORARILY. BY MIDNIGHT ALL
TERMINALS ARE EXPECTED TO RETURN TO UNIFORM MVFR CIGS. CANNOT RULE
OUT SOME CIGS BELOW 2KFT BUT DID NOT HAVE CONFIDENCE TO INCLUDE
THEM. UNCERTAINTY REMAINS AS TO WHEN SKIES SHOULD SCATTER OUT ON
SUNDAY. THE SCATTERING TREND SHOULD MOVE FROM SOUTHWEST TO
NORTHEAST...BUT CURRENT FORECAST DOES NOT ELIMINATE CIG FROM
PITTSBURGH AND LOCATIONS NORTHEAST UNTIL 00Z MONDAY.


OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$






000
FXUS61 KPBZ 210217
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
917 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL INTO MONDAY. EXPECT INCREASING
PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN AND WIND
CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
PRIMARY CHANGE WITH 915PM UPDATE WAS TO ADD SCATTERED FLURRIES
FROM PITTSBURGH AND TO THE NORTH AND WEST. SOME LIGHT RADAR ECHOES
HAVE MOVED FROM INDIANA INTO OHIO DURING THE AFTERNOON AND EARLY
EVENING HOURS...WITH A COUPLE OF AUTOMATED STATIONS REPORTING
LIGHT SNOW. IN THE LAST HOUR THREE SITES AROUND COLUMBUS OHIO HAVE
REPORTED SNOW...AND EXPECT THAT THIS FLURRY ACTIVITY COULD
CONTINUE AS IT IS ASSOCIATED WITH AN UPPER LEVEL SHORTWAVE MOVING
THROUGH THE REGION. FLURRIES SHOULD COME TO AN END AFTER MIDNIGHT.
A SLIGHT CHANCE OF LIGHT SNOW STILL CANNOT BE RULED OUT SOUTH AND
EAST OF PITTSBURGH WITH ANOTHER FEATURE...BUT NO ACCUMULATIONS ARE
EXPECTED ANYWHERE OVERNIGHT.

INVERSION IS MAINTAINED SUNDAY MORNING WHICH WILL MAINTAIN STRATUS
DECK...BUT BY AFTERNOON EXPECT STRATUS TO MIX OUT INTO A CU FIELD
AND THEN SCATTER OUT BY EVENING. A BIT MORE SUN SHOULD ALLOW FOR
AFTERNOON HIGH TEMPS AROUND 5 DEGREES WARMER THAN TODAY. CL

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
BENIGN WEATHER INITIALLY WITH HIGH PRESSURE TO OUR EAST AND IN
CONTROL.  SOUTHEAST WINDS IN RESPONSE TO SURFACE ANTICYCLONE
POSITION WILL FACILITATE DEVELOPMENT OF STRATUS OVER EASTERN
PORTIONS OF TUCKER AND GARRETT COUNTIES MONDAY INTO MONDAY NIGHT.
PCPN ONSET HAS SLOWED DOWN FROM PREVIOUS CYCLES...BUT THERE REMAINS
A VERY LOW PROBABILITY OF FREEZING RAIN AND/OR SLEET OVER
AFOREMENTIONED AREAS MONDAY.  FOR NOW...TRENDED FORECAST WITH PCPN
COMMENCING DURING THE AFTERNOON WHICH REFLECT LATEST NUMERICAL
MODELS.  WITH THIS SCENARIO...LOW LEVEL SUB-FREEZING AIR SHOULD
SCOUR OUT YIELDING AN ALL RAIN PTYPE.

RAIN SHADOW EFFECT TAKES PLACES TUESDAY WITH SOUTHEAST WINDS
WIDESPREAD OVER THE REGION. AN ISOLATED SHOWER REACHING EASTERN OHIO
AND FAR NWRN PA IS NOT OUT OF THE QUESTION...SO KEPT A SLIGHT
CHANCE.  WOULD NOT BE SURPRISED TO SEE BREAKS IN THE CLOUDS WHICH
COULD ALLOW FOR A FEW LOCATIONS TO EXCEED 60 DEGREES.  RECORD HIGHS
FOR PITTSBURGH...MORGANTOWN...AND ZANESVILLE ALL RESIDE WELL INTO
THE UPPER 60S...SO AT THIS JUNCTURE RECORD WARMTH IS NOT FORESEEN.
PRECIP ASSOCIATED WITH THE SURFACE LOW PRESSURE SYSTEM EJECTING FROM
THE GULF COAST REGION REACHES SERN AREAS OF THE FORECAST AREA THAT
EVENING.

A BLEND OF THE ONGOING FORECAST AND BIAS CORRECTED ECMWF WERE USED
FOR TEMPERATURES.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED GIVEN THE
TIME PERIOD WHICH IT AFFECTS OUR AREA IS STILL ON TRACK.  LONG RANGE
ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE CONVERGING ON
A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.  THIS WILL MAKE
FOR ALL LIQUID PRECIPITATION ON THE FRONT END.  TEMPERATURES WILL
SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY WITH 50S COMMON.
COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF MEXICO...SOUNDINGS
ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES TEMP DIFFERENTIAL
BETWEEN H8 AND H5 TO NEARLY 0C.  THIS COULD LEAD TO ISOLATED
THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE.  FOR THE TIME
BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT FOR
BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT.  DESPITE PWATS
NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT.  LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE PROJECTED
QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY.  FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST.  HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE GROUND
AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME.  ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER.  EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE.  NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS.  MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
WHILE FKL...DUJ...AND ZZV ARE EXPECTED TO REMAIN UNDER MVFR CIGS
OVERNIGHT...REMAINING TERMINALS MAY CONTINUE TO HAVE LOWER CLOUDS
SCATTER OUT LEAVING A MID DECK TEMPORARILY. BY MIDNIGHT ALL
TERMINALS ARE EXPECTED TO RETURN TO UNIFORM MVFR CIGS. CANNOT RULE
OUT SOME CIGS BELOW 2KFT BUT DID NOT HAVE CONFIDENCE TO INCLUDE
THEM. UNCERTAINTY REMAINS AS TO WHEN SKIES SHOULD SCATTER OUT ON
SUNDAY. THE SCATTERING TREND SHOULD MOVE FROM SOUTHWEST TO
NORTHEAST...BUT CURRENT FORECAST DOES NOT ELIMINATE CIG FROM
PITTSBURGH AND LOCATIONS NORTHEAST UNTIL 00Z MONDAY.


OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$






000
FXUS61 KPBZ 210217
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
917 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL INTO MONDAY. EXPECT INCREASING
PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN AND WIND
CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
PRIMARY CHANGE WITH 915PM UPDATE WAS TO ADD SCATTERED FLURRIES
FROM PITTSBURGH AND TO THE NORTH AND WEST. SOME LIGHT RADAR ECHOES
HAVE MOVED FROM INDIANA INTO OHIO DURING THE AFTERNOON AND EARLY
EVENING HOURS...WITH A COUPLE OF AUTOMATED STATIONS REPORTING
LIGHT SNOW. IN THE LAST HOUR THREE SITES AROUND COLUMBUS OHIO HAVE
REPORTED SNOW...AND EXPECT THAT THIS FLURRY ACTIVITY COULD
CONTINUE AS IT IS ASSOCIATED WITH AN UPPER LEVEL SHORTWAVE MOVING
THROUGH THE REGION. FLURRIES SHOULD COME TO AN END AFTER MIDNIGHT.
A SLIGHT CHANCE OF LIGHT SNOW STILL CANNOT BE RULED OUT SOUTH AND
EAST OF PITTSBURGH WITH ANOTHER FEATURE...BUT NO ACCUMULATIONS ARE
EXPECTED ANYWHERE OVERNIGHT.

INVERSION IS MAINTAINED SUNDAY MORNING WHICH WILL MAINTAIN STRATUS
DECK...BUT BY AFTERNOON EXPECT STRATUS TO MIX OUT INTO A CU FIELD
AND THEN SCATTER OUT BY EVENING. A BIT MORE SUN SHOULD ALLOW FOR
AFTERNOON HIGH TEMPS AROUND 5 DEGREES WARMER THAN TODAY. CL

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
BENIGN WEATHER INITIALLY WITH HIGH PRESSURE TO OUR EAST AND IN
CONTROL.  SOUTHEAST WINDS IN RESPONSE TO SURFACE ANTICYCLONE
POSITION WILL FACILITATE DEVELOPMENT OF STRATUS OVER EASTERN
PORTIONS OF TUCKER AND GARRETT COUNTIES MONDAY INTO MONDAY NIGHT.
PCPN ONSET HAS SLOWED DOWN FROM PREVIOUS CYCLES...BUT THERE REMAINS
A VERY LOW PROBABILITY OF FREEZING RAIN AND/OR SLEET OVER
AFOREMENTIONED AREAS MONDAY.  FOR NOW...TRENDED FORECAST WITH PCPN
COMMENCING DURING THE AFTERNOON WHICH REFLECT LATEST NUMERICAL
MODELS.  WITH THIS SCENARIO...LOW LEVEL SUB-FREEZING AIR SHOULD
SCOUR OUT YIELDING AN ALL RAIN PTYPE.

RAIN SHADOW EFFECT TAKES PLACES TUESDAY WITH SOUTHEAST WINDS
WIDESPREAD OVER THE REGION. AN ISOLATED SHOWER REACHING EASTERN OHIO
AND FAR NWRN PA IS NOT OUT OF THE QUESTION...SO KEPT A SLIGHT
CHANCE.  WOULD NOT BE SURPRISED TO SEE BREAKS IN THE CLOUDS WHICH
COULD ALLOW FOR A FEW LOCATIONS TO EXCEED 60 DEGREES.  RECORD HIGHS
FOR PITTSBURGH...MORGANTOWN...AND ZANESVILLE ALL RESIDE WELL INTO
THE UPPER 60S...SO AT THIS JUNCTURE RECORD WARMTH IS NOT FORESEEN.
PRECIP ASSOCIATED WITH THE SURFACE LOW PRESSURE SYSTEM EJECTING FROM
THE GULF COAST REGION REACHES SERN AREAS OF THE FORECAST AREA THAT
EVENING.

A BLEND OF THE ONGOING FORECAST AND BIAS CORRECTED ECMWF WERE USED
FOR TEMPERATURES.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED GIVEN THE
TIME PERIOD WHICH IT AFFECTS OUR AREA IS STILL ON TRACK.  LONG RANGE
ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE CONVERGING ON
A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.  THIS WILL MAKE
FOR ALL LIQUID PRECIPITATION ON THE FRONT END.  TEMPERATURES WILL
SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY WITH 50S COMMON.
COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF MEXICO...SOUNDINGS
ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES TEMP DIFFERENTIAL
BETWEEN H8 AND H5 TO NEARLY 0C.  THIS COULD LEAD TO ISOLATED
THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE.  FOR THE TIME
BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT FOR
BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT.  DESPITE PWATS
NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT.  LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE PROJECTED
QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY.  FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST.  HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE GROUND
AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME.  ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER.  EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE.  NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS.  MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
WHILE FKL...DUJ...AND ZZV ARE EXPECTED TO REMAIN UNDER MVFR CIGS
OVERNIGHT...REMAINING TERMINALS MAY CONTINUE TO HAVE LOWER CLOUDS
SCATTER OUT LEAVING A MID DECK TEMPORARILY. BY MIDNIGHT ALL
TERMINALS ARE EXPECTED TO RETURN TO UNIFORM MVFR CIGS. CANNOT RULE
OUT SOME CIGS BELOW 2KFT BUT DID NOT HAVE CONFIDENCE TO INCLUDE
THEM. UNCERTAINTY REMAINS AS TO WHEN SKIES SHOULD SCATTER OUT ON
SUNDAY. THE SCATTERING TREND SHOULD MOVE FROM SOUTHWEST TO
NORTHEAST...BUT CURRENT FORECAST DOES NOT ELIMINATE CIG FROM
PITTSBURGH AND LOCATIONS NORTHEAST UNTIL 00Z MONDAY.


OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$






000
FXUS61 KPBZ 210217
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
917 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL INTO MONDAY. EXPECT INCREASING
PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN AND WIND
CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
PRIMARY CHANGE WITH 915PM UPDATE WAS TO ADD SCATTERED FLURRIES
FROM PITTSBURGH AND TO THE NORTH AND WEST. SOME LIGHT RADAR ECHOES
HAVE MOVED FROM INDIANA INTO OHIO DURING THE AFTERNOON AND EARLY
EVENING HOURS...WITH A COUPLE OF AUTOMATED STATIONS REPORTING
LIGHT SNOW. IN THE LAST HOUR THREE SITES AROUND COLUMBUS OHIO HAVE
REPORTED SNOW...AND EXPECT THAT THIS FLURRY ACTIVITY COULD
CONTINUE AS IT IS ASSOCIATED WITH AN UPPER LEVEL SHORTWAVE MOVING
THROUGH THE REGION. FLURRIES SHOULD COME TO AN END AFTER MIDNIGHT.
A SLIGHT CHANCE OF LIGHT SNOW STILL CANNOT BE RULED OUT SOUTH AND
EAST OF PITTSBURGH WITH ANOTHER FEATURE...BUT NO ACCUMULATIONS ARE
EXPECTED ANYWHERE OVERNIGHT.

INVERSION IS MAINTAINED SUNDAY MORNING WHICH WILL MAINTAIN STRATUS
DECK...BUT BY AFTERNOON EXPECT STRATUS TO MIX OUT INTO A CU FIELD
AND THEN SCATTER OUT BY EVENING. A BIT MORE SUN SHOULD ALLOW FOR
AFTERNOON HIGH TEMPS AROUND 5 DEGREES WARMER THAN TODAY. CL

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
BENIGN WEATHER INITIALLY WITH HIGH PRESSURE TO OUR EAST AND IN
CONTROL.  SOUTHEAST WINDS IN RESPONSE TO SURFACE ANTICYCLONE
POSITION WILL FACILITATE DEVELOPMENT OF STRATUS OVER EASTERN
PORTIONS OF TUCKER AND GARRETT COUNTIES MONDAY INTO MONDAY NIGHT.
PCPN ONSET HAS SLOWED DOWN FROM PREVIOUS CYCLES...BUT THERE REMAINS
A VERY LOW PROBABILITY OF FREEZING RAIN AND/OR SLEET OVER
AFOREMENTIONED AREAS MONDAY.  FOR NOW...TRENDED FORECAST WITH PCPN
COMMENCING DURING THE AFTERNOON WHICH REFLECT LATEST NUMERICAL
MODELS.  WITH THIS SCENARIO...LOW LEVEL SUB-FREEZING AIR SHOULD
SCOUR OUT YIELDING AN ALL RAIN PTYPE.

RAIN SHADOW EFFECT TAKES PLACES TUESDAY WITH SOUTHEAST WINDS
WIDESPREAD OVER THE REGION. AN ISOLATED SHOWER REACHING EASTERN OHIO
AND FAR NWRN PA IS NOT OUT OF THE QUESTION...SO KEPT A SLIGHT
CHANCE.  WOULD NOT BE SURPRISED TO SEE BREAKS IN THE CLOUDS WHICH
COULD ALLOW FOR A FEW LOCATIONS TO EXCEED 60 DEGREES.  RECORD HIGHS
FOR PITTSBURGH...MORGANTOWN...AND ZANESVILLE ALL RESIDE WELL INTO
THE UPPER 60S...SO AT THIS JUNCTURE RECORD WARMTH IS NOT FORESEEN.
PRECIP ASSOCIATED WITH THE SURFACE LOW PRESSURE SYSTEM EJECTING FROM
THE GULF COAST REGION REACHES SERN AREAS OF THE FORECAST AREA THAT
EVENING.

A BLEND OF THE ONGOING FORECAST AND BIAS CORRECTED ECMWF WERE USED
FOR TEMPERATURES.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED GIVEN THE
TIME PERIOD WHICH IT AFFECTS OUR AREA IS STILL ON TRACK.  LONG RANGE
ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE CONVERGING ON
A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.  THIS WILL MAKE
FOR ALL LIQUID PRECIPITATION ON THE FRONT END.  TEMPERATURES WILL
SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY WITH 50S COMMON.
COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF MEXICO...SOUNDINGS
ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES TEMP DIFFERENTIAL
BETWEEN H8 AND H5 TO NEARLY 0C.  THIS COULD LEAD TO ISOLATED
THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE.  FOR THE TIME
BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT FOR
BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT.  DESPITE PWATS
NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT.  LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE PROJECTED
QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY.  FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST.  HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE GROUND
AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME.  ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER.  EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE.  NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS.  MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
WHILE FKL...DUJ...AND ZZV ARE EXPECTED TO REMAIN UNDER MVFR CIGS
OVERNIGHT...REMAINING TERMINALS MAY CONTINUE TO HAVE LOWER CLOUDS
SCATTER OUT LEAVING A MID DECK TEMPORARILY. BY MIDNIGHT ALL
TERMINALS ARE EXPECTED TO RETURN TO UNIFORM MVFR CIGS. CANNOT RULE
OUT SOME CIGS BELOW 2KFT BUT DID NOT HAVE CONFIDENCE TO INCLUDE
THEM. UNCERTAINTY REMAINS AS TO WHEN SKIES SHOULD SCATTER OUT ON
SUNDAY. THE SCATTERING TREND SHOULD MOVE FROM SOUTHWEST TO
NORTHEAST...BUT CURRENT FORECAST DOES NOT ELIMINATE CIG FROM
PITTSBURGH AND LOCATIONS NORTHEAST UNTIL 00Z MONDAY.


OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$






000
FXUS61 KPHI 210216
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
916 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY BUILD SOUTHWESTWARD INTO THE REGION
FROM ATLANTIC CANADA THROUGH MONDAY. LOW PRESSURE WILL ORGANIZE
OFF THE CAROLINAS MONDAY NIGHT AND MOVE NORTHEASTWARD OFFSHORE ON
TUESDAY. MEANWHILE...ANOTHER AREA OF LOW PRESSURE WILL DEVELOP
OVER THE OHIO VALLEY AND MOVE NORTHWARD INTO QUEBEC...LEADING TO A
STRONG COLD FRONTAL PASSAGE ON THURSDAY NIGHT. HIGH PRESSURE WILL
BUILD IN ON FRIDAY AND A WEAKER COLD FRONT MAY APPROACH THE REGION
NEXT WEEKEND.

&&

.NEAR TERM /THROUGH SUNDAY/...
WEAK SURFACE HIGH PRESSURE WILL REMAIN ACROSS THE AREA TONIGHT.
PLENTY OF MOISTURE REMAINS TRAPPED BELOW A LOW LEVEL INVERSION,
ESPECIALLY PHILLY NORTH. THE LOW CLOUDS HAVE BROKEN UP SOUTH OF
PHILLY, BUT SKIES WILL FILL UP AGAIN AS A MID-LEVEL DECK ADVECTS
IN OVERNIGHT. THESE CLOUDS ARE ASSOCIATED WITH A MID-LEVEL SHORT
WAVE.

THE HIGH RESOLUTION MODELS KEEP THE CWA PRECIP-FREE(MEASURABLE)
THROUGH THE OVERNIGHT AS DOES THE LOWER RES MODELS. WE`LL KEEP THE
GRIDS AS IS, BUT CAN`T RULE OUT A FLURRY OR TWO UP ACROSS THE
NORTHERN THIRD OF THE CWA.

ANOTHER SEASONABLY COLD NIGHT IS EXPECTED WITH LOWS IN THE LOW 20S
NORTH AND MID OR UPPER 20S SOUTH. WINDS WILL BE LIGHT FROM THE
NORTH.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH 6 PM SUNDAY/...
AFTER A WEAK SHORTWAVE CROSSES THE AREA SUN MORNING...UPPER RIDGING
WILL TAKE PLACE. THIS WILL HOPEFULLY ALLOW MORE SUNSHINE ACROSS THE
AREA. WE HAVE WRITTEN A PARTLY TO MOSTLY SUNNY FCST FOR NOW. WE HELD
ONTO SOME EXTRA CLOUD COVER ACROSS THE SRN POCONOS HOWEVER. HIGH
TEMPERATURES SUNDAY WILL RISE INTO THE LOW 40S ACROSS SRN NJ AND THE
DELMARVA...WHILE READINGS HOLD IN THE MID/UPPER 30S ACROSS THE
NORTH/WEST AREAS. WINDS WILL REMAIN LIGHT...MOSTLY FROM THE NORTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...

* FREEZING RAIN POSSIBLE MONDAY NIGHT OVER THE NORTHWEST.
* INCREASING POTENTIAL FOR HEAVY RAIN CHRISTMAS EVE WITH
  TEMPERATURES WELL ABOVE NORMAL.
* BRISK WESTERLY WIND CHRISTMAS DAY W/FLURRIES POSSIBLE.

OVERVIEW...

VIGOROUS MID-LEVEL DISTURBANCE AND ACCOMPANYING 160 KNOT UPPER-LEVEL
JET MAX COMING ASHORE OVER THE PACIFIC NORTHWEST LATE THIS WEEKEND
WILL LEAD TO A DEEP TROUGH OVER THE MISSISSIPPI VALLEY BY MID-WEEK.
INITIAL PIECE OF ENERGY AHEAD OF THIS TROUGH IS EJECTED NORTHEAST
AND WILL LEAD TO THE DEVELOPMENT OF AN AREA OF LOW-PRESSURE OFF THE
CAROLINAS ON MONDAY. THIS WEAK FEATURE SHOULD TRACK OFFSHORE WELL
SOUTHEAST OF THE REGION ON TUESDAY PER TODAYS 12Z UKMET AND GFS...
FEEL THE NAM AND ECMWF ARE TOO FAR NORTH, SLOW, AND DEEP W/THIS
FEATURE...THUS THEY ALSO CRANK OUT TOO MUCH QPF. NEVERTHELESS...
QPF COMBINED WITH MARGINAL TEMPERATURE PROFILES OVER THE NORTHWEST
COULD SUPPORT SOME LIGHT FREEZING RAIN MONDAY NIGHT. MID-LEVEL FLOW
THEN BECOMES INCREASINGLY MERIDIONAL...PUMPING ANOMALOUSLY WARM
AND MOIST AIR UP THE EAST COAST...SETTING THE STAGE FOR HEAVY RAIN
ON CHRISTMAS EVE DAY. THE TROUGH LOOKS TO BECOME NEGATIVELY TILTED
AS IT CROSSES THE REGION...LEADING TO A STRONG FRONTAL PASSAGE LATE
WEDNESDAY INTO EARLY THURSDAY...WITH SOME FLURRIES POSSIBLE ON THE
BACK-SIDE OF THE STORM SYSTEM.

DETAILS...

MONDAY...
MID-LEVEL RIDGE CRESTS OVER THE REGION EARLY IN THE DAY...W/SURFACE
HIGH ANCHORED ALONG THE EAST COAST IN A COLD-AIR DAMMING SIGNATURE.
PRECIPITATION WILL BE LARGELY DRIVEN BY INSENTROPIC ASCENT OVER THE
COLDER LOW-LEVEL AIRMASS AND WILL BEGIN LATE IN THE DAY AS MOISTURE
STREAMS IN ALOFT AND LOW-LEVELS GRADUALLY SATURATE. THERE MAY BE A
PERIOD OF LIGHT FREEZING RAIN OVER THE NORTHWEST AS A COLD AIR
IS REINFORCED W/NORTHERLY SURFACE WINDS AND PRECIP LEADS TO
EVAPORATIONAL COOLING.

TUESDAY...
ANY LIGHT FREEZING RAIN SHOULD END EARLY IN THE MORNING WITH STRONG
WARM AIR ADVECTION ALOFT. ALTHOUGH THE BEST FORCING REMAINS WELL TO
THE WEST...BROAD ISENTROPIC ASCENT AND INCREASING MOISTURE SHOULD
LEAD TO SCATTERED RAIN SHOWERS THRU THE DAY. QPF SHOULD BE GENERALLY
LIGHT.

WEDNESDAY...
A VIGOROUS TROUGH APPROACHES FROM THE WEST W/STILL SOME SPREAD NOTED
FROM THE MEAN IN BOTH THE ECENS AND GEFS 500 HPA HEIGHT FIELDS...
INDICATING SOME DISAGREEMENT WITH REGARD TO WHAT DEGREE IT GOES
NEGATIVELY TILTED. NEVERTHELESS...A VERY DYNAMIC SYSTEM WITH SEVERAL
INGREDIENTS COMING TOGETHER FOR UP TO 1-2 INCHES OF QPF...ESPECIALLY
OVER THE HIGHER TERRAIN. NOTING A STRONG MID-LEVEL VORT MAX AND THE
LEFT-FRONT QUADRANT OF A 160 KNOT UPPER-LEVEL JET TRAVERSING THE
APPALACHIANS. ALSO NOTING STRONG WARM AIR ADVECTION AND ANOMALOUSLY
HIGH /2-3 STANDARD DEVIATION/ PRECIPITABLE WATER VALUES STREAMING
UP THE EASTERN SEABOARD. THUS THERE IS PLENTY OF MOISTURE AND
ASCENT FOR HEAVY RAINFALL...W/THE MODELS KEYING IN ON WEDNESDAY
AFTERNOON AND WEDNESDAY NIGHT FOR THE BULK OF THE PRECIP...AND
THIS WILL NEED TO BE MONITORED FOR FLOODING POTENTIAL PARTICULARLY
DUE TO THE HOLIDAY TRAVEL CHRISTMAS EVE. LATER SHIFTS WILL ALSO
NEED TO FURTHER EVALUATE THE POTENTIAL FOR GUSTY SURFACE WINDS
AND CONVECTION.

THURSDAY AND FRIDAY...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS TO
BUILD IN. TEMPERATURES WILL REMAIN ABOVE SEASONABLE LEVELS AND THERE
COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW ON THURSDAY...
PARTICULARLY NORTHWEST.

SATURDAY...ANOTHER COLD FRONT MAY APPROACH THE REGION...BUT IT/S TOO
EARLY TO SPECULATE...ESPECIALLY GIVEN THE UNCERTAINTY THAT THE STORM
SYSTEM MOVING THROUGH THE NORTHEAST CONUS MID-WEEK COULD ADD TO THE
FORECAST.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THERE HAS BEEN PLENTY OF LOW LEVEL MOISTURE TRAPPED BELOW THE
INVERSION AGAIN TODAY. CIGS WERE BETWEEN 025-035 ACROSS THE AREA
THIS AFTERNOON. THIS EVENING WE`RE SEEING MORE 030-035. STILL,
MOSTLY IN THE NORTH QUADRANT.

WE`LL KEEP THE LOW CLOUDS IN THE TERMINALS FROM KPHL NORTHWARD
THROUGH THE NIGHT. TO THE SOUTH, WE`VE SCATTERED THE LOW LEVEL
DECK OUT. A SHORT WAVE WILL BRING SOME ALTOCU TO JUST ABOUT
EVERYWHERE OVERNIGHT.

WINDS WILL REMAIN LIGHT OVERNIGHT. NO PRECIPITATION HAS BEEN
MENTIONED.

OUTLOOK...

SUNDAY NIGHT AND MONDAY MORNING...VFR.

MONDAY AFTERNOON...POTENTIAL FOR MVFR CIGS AS MARINE LAYER BECOMES
ESTABLISHED AND STRATUS ADVECTS INLAND.

MONDAY NIGHT THROUGH TUESDAY NIGHT...THE COMBINATION OF
STRENGTHENING ONSHORE FLOW AND IN-SITU CAD FROM LIGHT RAIN
OVERSPREADING THE TERMINALS COULD YIELD AN EXTENDED PERIOD OF
MVFR/IFR CONDITIONS (CIGS WOULD BE THE MORE LIKELY CONTRIBUTOR TO
IFR THAN VSBYS) MONDAY NIGHT INTO TUESDAY.

WEDNESDAY...WINDS VEER MORE OUT OF THE SOUTH AS A WARM FRONT SLOWLY
LIFTS NORTHWARD. RAIN IS EXPECTED TO BE THE MOST WIDESPREAD AND
HEAVIEST DURING THIS PART OF THE FORECAST PERIOD. PREDOMINATELY MVFR
AND IFR CONDITIONS. SOUTHERLY WINDS WILL BECOME BREEZY FOLLOWING
WARM FROPA.

WEDNESDAY NIGHT...COLD FRONT IS FORECAST TO MOVE THRU SOMETIME AT
NIGHT. LOW CLOUDS AND RAIN WILL END FROM WEST TO EAST IN WAKE OF
FROPA.

THURSDAY...WESTERLY WINDS COULD BECOME STRONG BEHIND THE FRONT
THURSDAY WITH BUFKIT FORECAST SOUNDINGS FROM THE 12Z GFS SHOWING THE
POTENTIAL FOR 30-40 KT GUSTS.

&&

.MARINE...
WEAK HIGH PRESSURE WILL REMAIN ACROSS THE WATERS TONIGHT AND SUNDAY.
WINDS AND SEAS WILL REMAIN BELOW SCA FLAG CRITERIA. WINDS WILL
MOSTLY BE NORTHERLY THROUGH THE PERIOD.

OUTLOOK...
SUNDAY NIGHT THROUGH MONDAY NIGHT...WINDS AND SEAS BELOW SCA
CRITERIA.

TUESDAY AND TUESDAY NIGHT...ONSHORE FLOW STRENGTHENS ON TUESDAY.
WINDS 15-20 KT FORECAST ON TUESDAY. SEAS ARE FORECAST TO BUILD TO
5-6 FEET TUESDAY AND TUESDAY NIGHT, WARRANTING THE NEED FOR A SCA.

WEDNESDAY AND WEDNESDAY NIGHT...SOUTHERLY WINDS STRENGTHEN AFTER
WARM FROPA. DESPITE WINDS OF 40-50 KT FORECAST 1000 FT ABOVE THE
SURFACE, THERMAL PROFILES NOT FAVORABLE FOR MIXING WITH THE SETUP OF
WARM AIR MOVING ATOP THE COOLER WATERS. EXPECTING MORE OF A HIGH END
SCA WITH 25-30 KT WINDS. WINDS FORECAST TO BECOME WESTERLY LATE
WEDNESDAY NIGHT BEHIND A COLD FRONT BUT THE CORE OF THE COLD AIR
WILL STILL REMAIN UPSTREAM OF THE WATERS. SEAS FORECAST TO INCREASE
TO 6-8 FEET.

THURSDAY...GUSTY WESTERLY WINDS EXPECTED. GALES CERTAINLY A
POSSIBILITY.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...O`HARA
SHORT TERM...O`HARA
LONG TERM...FRANCK
AVIATION...FRANCK/KLEIN/O`HARA
MARINE...KLEIN/O`HARA







000
FXUS61 KPHI 210216
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
916 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY BUILD SOUTHWESTWARD INTO THE REGION
FROM ATLANTIC CANADA THROUGH MONDAY. LOW PRESSURE WILL ORGANIZE
OFF THE CAROLINAS MONDAY NIGHT AND MOVE NORTHEASTWARD OFFSHORE ON
TUESDAY. MEANWHILE...ANOTHER AREA OF LOW PRESSURE WILL DEVELOP
OVER THE OHIO VALLEY AND MOVE NORTHWARD INTO QUEBEC...LEADING TO A
STRONG COLD FRONTAL PASSAGE ON THURSDAY NIGHT. HIGH PRESSURE WILL
BUILD IN ON FRIDAY AND A WEAKER COLD FRONT MAY APPROACH THE REGION
NEXT WEEKEND.

&&

.NEAR TERM /THROUGH SUNDAY/...
WEAK SURFACE HIGH PRESSURE WILL REMAIN ACROSS THE AREA TONIGHT.
PLENTY OF MOISTURE REMAINS TRAPPED BELOW A LOW LEVEL INVERSION,
ESPECIALLY PHILLY NORTH. THE LOW CLOUDS HAVE BROKEN UP SOUTH OF
PHILLY, BUT SKIES WILL FILL UP AGAIN AS A MID-LEVEL DECK ADVECTS
IN OVERNIGHT. THESE CLOUDS ARE ASSOCIATED WITH A MID-LEVEL SHORT
WAVE.

THE HIGH RESOLUTION MODELS KEEP THE CWA PRECIP-FREE(MEASURABLE)
THROUGH THE OVERNIGHT AS DOES THE LOWER RES MODELS. WE`LL KEEP THE
GRIDS AS IS, BUT CAN`T RULE OUT A FLURRY OR TWO UP ACROSS THE
NORTHERN THIRD OF THE CWA.

ANOTHER SEASONABLY COLD NIGHT IS EXPECTED WITH LOWS IN THE LOW 20S
NORTH AND MID OR UPPER 20S SOUTH. WINDS WILL BE LIGHT FROM THE
NORTH.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH 6 PM SUNDAY/...
AFTER A WEAK SHORTWAVE CROSSES THE AREA SUN MORNING...UPPER RIDGING
WILL TAKE PLACE. THIS WILL HOPEFULLY ALLOW MORE SUNSHINE ACROSS THE
AREA. WE HAVE WRITTEN A PARTLY TO MOSTLY SUNNY FCST FOR NOW. WE HELD
ONTO SOME EXTRA CLOUD COVER ACROSS THE SRN POCONOS HOWEVER. HIGH
TEMPERATURES SUNDAY WILL RISE INTO THE LOW 40S ACROSS SRN NJ AND THE
DELMARVA...WHILE READINGS HOLD IN THE MID/UPPER 30S ACROSS THE
NORTH/WEST AREAS. WINDS WILL REMAIN LIGHT...MOSTLY FROM THE NORTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...

* FREEZING RAIN POSSIBLE MONDAY NIGHT OVER THE NORTHWEST.
* INCREASING POTENTIAL FOR HEAVY RAIN CHRISTMAS EVE WITH
  TEMPERATURES WELL ABOVE NORMAL.
* BRISK WESTERLY WIND CHRISTMAS DAY W/FLURRIES POSSIBLE.

OVERVIEW...

VIGOROUS MID-LEVEL DISTURBANCE AND ACCOMPANYING 160 KNOT UPPER-LEVEL
JET MAX COMING ASHORE OVER THE PACIFIC NORTHWEST LATE THIS WEEKEND
WILL LEAD TO A DEEP TROUGH OVER THE MISSISSIPPI VALLEY BY MID-WEEK.
INITIAL PIECE OF ENERGY AHEAD OF THIS TROUGH IS EJECTED NORTHEAST
AND WILL LEAD TO THE DEVELOPMENT OF AN AREA OF LOW-PRESSURE OFF THE
CAROLINAS ON MONDAY. THIS WEAK FEATURE SHOULD TRACK OFFSHORE WELL
SOUTHEAST OF THE REGION ON TUESDAY PER TODAYS 12Z UKMET AND GFS...
FEEL THE NAM AND ECMWF ARE TOO FAR NORTH, SLOW, AND DEEP W/THIS
FEATURE...THUS THEY ALSO CRANK OUT TOO MUCH QPF. NEVERTHELESS...
QPF COMBINED WITH MARGINAL TEMPERATURE PROFILES OVER THE NORTHWEST
COULD SUPPORT SOME LIGHT FREEZING RAIN MONDAY NIGHT. MID-LEVEL FLOW
THEN BECOMES INCREASINGLY MERIDIONAL...PUMPING ANOMALOUSLY WARM
AND MOIST AIR UP THE EAST COAST...SETTING THE STAGE FOR HEAVY RAIN
ON CHRISTMAS EVE DAY. THE TROUGH LOOKS TO BECOME NEGATIVELY TILTED
AS IT CROSSES THE REGION...LEADING TO A STRONG FRONTAL PASSAGE LATE
WEDNESDAY INTO EARLY THURSDAY...WITH SOME FLURRIES POSSIBLE ON THE
BACK-SIDE OF THE STORM SYSTEM.

DETAILS...

MONDAY...
MID-LEVEL RIDGE CRESTS OVER THE REGION EARLY IN THE DAY...W/SURFACE
HIGH ANCHORED ALONG THE EAST COAST IN A COLD-AIR DAMMING SIGNATURE.
PRECIPITATION WILL BE LARGELY DRIVEN BY INSENTROPIC ASCENT OVER THE
COLDER LOW-LEVEL AIRMASS AND WILL BEGIN LATE IN THE DAY AS MOISTURE
STREAMS IN ALOFT AND LOW-LEVELS GRADUALLY SATURATE. THERE MAY BE A
PERIOD OF LIGHT FREEZING RAIN OVER THE NORTHWEST AS A COLD AIR
IS REINFORCED W/NORTHERLY SURFACE WINDS AND PRECIP LEADS TO
EVAPORATIONAL COOLING.

TUESDAY...
ANY LIGHT FREEZING RAIN SHOULD END EARLY IN THE MORNING WITH STRONG
WARM AIR ADVECTION ALOFT. ALTHOUGH THE BEST FORCING REMAINS WELL TO
THE WEST...BROAD ISENTROPIC ASCENT AND INCREASING MOISTURE SHOULD
LEAD TO SCATTERED RAIN SHOWERS THRU THE DAY. QPF SHOULD BE GENERALLY
LIGHT.

WEDNESDAY...
A VIGOROUS TROUGH APPROACHES FROM THE WEST W/STILL SOME SPREAD NOTED
FROM THE MEAN IN BOTH THE ECENS AND GEFS 500 HPA HEIGHT FIELDS...
INDICATING SOME DISAGREEMENT WITH REGARD TO WHAT DEGREE IT GOES
NEGATIVELY TILTED. NEVERTHELESS...A VERY DYNAMIC SYSTEM WITH SEVERAL
INGREDIENTS COMING TOGETHER FOR UP TO 1-2 INCHES OF QPF...ESPECIALLY
OVER THE HIGHER TERRAIN. NOTING A STRONG MID-LEVEL VORT MAX AND THE
LEFT-FRONT QUADRANT OF A 160 KNOT UPPER-LEVEL JET TRAVERSING THE
APPALACHIANS. ALSO NOTING STRONG WARM AIR ADVECTION AND ANOMALOUSLY
HIGH /2-3 STANDARD DEVIATION/ PRECIPITABLE WATER VALUES STREAMING
UP THE EASTERN SEABOARD. THUS THERE IS PLENTY OF MOISTURE AND
ASCENT FOR HEAVY RAINFALL...W/THE MODELS KEYING IN ON WEDNESDAY
AFTERNOON AND WEDNESDAY NIGHT FOR THE BULK OF THE PRECIP...AND
THIS WILL NEED TO BE MONITORED FOR FLOODING POTENTIAL PARTICULARLY
DUE TO THE HOLIDAY TRAVEL CHRISTMAS EVE. LATER SHIFTS WILL ALSO
NEED TO FURTHER EVALUATE THE POTENTIAL FOR GUSTY SURFACE WINDS
AND CONVECTION.

THURSDAY AND FRIDAY...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS TO
BUILD IN. TEMPERATURES WILL REMAIN ABOVE SEASONABLE LEVELS AND THERE
COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW ON THURSDAY...
PARTICULARLY NORTHWEST.

SATURDAY...ANOTHER COLD FRONT MAY APPROACH THE REGION...BUT IT/S TOO
EARLY TO SPECULATE...ESPECIALLY GIVEN THE UNCERTAINTY THAT THE STORM
SYSTEM MOVING THROUGH THE NORTHEAST CONUS MID-WEEK COULD ADD TO THE
FORECAST.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THERE HAS BEEN PLENTY OF LOW LEVEL MOISTURE TRAPPED BELOW THE
INVERSION AGAIN TODAY. CIGS WERE BETWEEN 025-035 ACROSS THE AREA
THIS AFTERNOON. THIS EVENING WE`RE SEEING MORE 030-035. STILL,
MOSTLY IN THE NORTH QUADRANT.

WE`LL KEEP THE LOW CLOUDS IN THE TERMINALS FROM KPHL NORTHWARD
THROUGH THE NIGHT. TO THE SOUTH, WE`VE SCATTERED THE LOW LEVEL
DECK OUT. A SHORT WAVE WILL BRING SOME ALTOCU TO JUST ABOUT
EVERYWHERE OVERNIGHT.

WINDS WILL REMAIN LIGHT OVERNIGHT. NO PRECIPITATION HAS BEEN
MENTIONED.

OUTLOOK...

SUNDAY NIGHT AND MONDAY MORNING...VFR.

MONDAY AFTERNOON...POTENTIAL FOR MVFR CIGS AS MARINE LAYER BECOMES
ESTABLISHED AND STRATUS ADVECTS INLAND.

MONDAY NIGHT THROUGH TUESDAY NIGHT...THE COMBINATION OF
STRENGTHENING ONSHORE FLOW AND IN-SITU CAD FROM LIGHT RAIN
OVERSPREADING THE TERMINALS COULD YIELD AN EXTENDED PERIOD OF
MVFR/IFR CONDITIONS (CIGS WOULD BE THE MORE LIKELY CONTRIBUTOR TO
IFR THAN VSBYS) MONDAY NIGHT INTO TUESDAY.

WEDNESDAY...WINDS VEER MORE OUT OF THE SOUTH AS A WARM FRONT SLOWLY
LIFTS NORTHWARD. RAIN IS EXPECTED TO BE THE MOST WIDESPREAD AND
HEAVIEST DURING THIS PART OF THE FORECAST PERIOD. PREDOMINATELY MVFR
AND IFR CONDITIONS. SOUTHERLY WINDS WILL BECOME BREEZY FOLLOWING
WARM FROPA.

WEDNESDAY NIGHT...COLD FRONT IS FORECAST TO MOVE THRU SOMETIME AT
NIGHT. LOW CLOUDS AND RAIN WILL END FROM WEST TO EAST IN WAKE OF
FROPA.

THURSDAY...WESTERLY WINDS COULD BECOME STRONG BEHIND THE FRONT
THURSDAY WITH BUFKIT FORECAST SOUNDINGS FROM THE 12Z GFS SHOWING THE
POTENTIAL FOR 30-40 KT GUSTS.

&&

.MARINE...
WEAK HIGH PRESSURE WILL REMAIN ACROSS THE WATERS TONIGHT AND SUNDAY.
WINDS AND SEAS WILL REMAIN BELOW SCA FLAG CRITERIA. WINDS WILL
MOSTLY BE NORTHERLY THROUGH THE PERIOD.

OUTLOOK...
SUNDAY NIGHT THROUGH MONDAY NIGHT...WINDS AND SEAS BELOW SCA
CRITERIA.

TUESDAY AND TUESDAY NIGHT...ONSHORE FLOW STRENGTHENS ON TUESDAY.
WINDS 15-20 KT FORECAST ON TUESDAY. SEAS ARE FORECAST TO BUILD TO
5-6 FEET TUESDAY AND TUESDAY NIGHT, WARRANTING THE NEED FOR A SCA.

WEDNESDAY AND WEDNESDAY NIGHT...SOUTHERLY WINDS STRENGTHEN AFTER
WARM FROPA. DESPITE WINDS OF 40-50 KT FORECAST 1000 FT ABOVE THE
SURFACE, THERMAL PROFILES NOT FAVORABLE FOR MIXING WITH THE SETUP OF
WARM AIR MOVING ATOP THE COOLER WATERS. EXPECTING MORE OF A HIGH END
SCA WITH 25-30 KT WINDS. WINDS FORECAST TO BECOME WESTERLY LATE
WEDNESDAY NIGHT BEHIND A COLD FRONT BUT THE CORE OF THE COLD AIR
WILL STILL REMAIN UPSTREAM OF THE WATERS. SEAS FORECAST TO INCREASE
TO 6-8 FEET.

THURSDAY...GUSTY WESTERLY WINDS EXPECTED. GALES CERTAINLY A
POSSIBILITY.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...O`HARA
SHORT TERM...O`HARA
LONG TERM...FRANCK
AVIATION...FRANCK/KLEIN/O`HARA
MARINE...KLEIN/O`HARA







000
FXUS61 KPHI 210216
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
916 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY BUILD SOUTHWESTWARD INTO THE REGION
FROM ATLANTIC CANADA THROUGH MONDAY. LOW PRESSURE WILL ORGANIZE
OFF THE CAROLINAS MONDAY NIGHT AND MOVE NORTHEASTWARD OFFSHORE ON
TUESDAY. MEANWHILE...ANOTHER AREA OF LOW PRESSURE WILL DEVELOP
OVER THE OHIO VALLEY AND MOVE NORTHWARD INTO QUEBEC...LEADING TO A
STRONG COLD FRONTAL PASSAGE ON THURSDAY NIGHT. HIGH PRESSURE WILL
BUILD IN ON FRIDAY AND A WEAKER COLD FRONT MAY APPROACH THE REGION
NEXT WEEKEND.

&&

.NEAR TERM /THROUGH SUNDAY/...
WEAK SURFACE HIGH PRESSURE WILL REMAIN ACROSS THE AREA TONIGHT.
PLENTY OF MOISTURE REMAINS TRAPPED BELOW A LOW LEVEL INVERSION,
ESPECIALLY PHILLY NORTH. THE LOW CLOUDS HAVE BROKEN UP SOUTH OF
PHILLY, BUT SKIES WILL FILL UP AGAIN AS A MID-LEVEL DECK ADVECTS
IN OVERNIGHT. THESE CLOUDS ARE ASSOCIATED WITH A MID-LEVEL SHORT
WAVE.

THE HIGH RESOLUTION MODELS KEEP THE CWA PRECIP-FREE(MEASURABLE)
THROUGH THE OVERNIGHT AS DOES THE LOWER RES MODELS. WE`LL KEEP THE
GRIDS AS IS, BUT CAN`T RULE OUT A FLURRY OR TWO UP ACROSS THE
NORTHERN THIRD OF THE CWA.

ANOTHER SEASONABLY COLD NIGHT IS EXPECTED WITH LOWS IN THE LOW 20S
NORTH AND MID OR UPPER 20S SOUTH. WINDS WILL BE LIGHT FROM THE
NORTH.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH 6 PM SUNDAY/...
AFTER A WEAK SHORTWAVE CROSSES THE AREA SUN MORNING...UPPER RIDGING
WILL TAKE PLACE. THIS WILL HOPEFULLY ALLOW MORE SUNSHINE ACROSS THE
AREA. WE HAVE WRITTEN A PARTLY TO MOSTLY SUNNY FCST FOR NOW. WE HELD
ONTO SOME EXTRA CLOUD COVER ACROSS THE SRN POCONOS HOWEVER. HIGH
TEMPERATURES SUNDAY WILL RISE INTO THE LOW 40S ACROSS SRN NJ AND THE
DELMARVA...WHILE READINGS HOLD IN THE MID/UPPER 30S ACROSS THE
NORTH/WEST AREAS. WINDS WILL REMAIN LIGHT...MOSTLY FROM THE NORTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...

* FREEZING RAIN POSSIBLE MONDAY NIGHT OVER THE NORTHWEST.
* INCREASING POTENTIAL FOR HEAVY RAIN CHRISTMAS EVE WITH
  TEMPERATURES WELL ABOVE NORMAL.
* BRISK WESTERLY WIND CHRISTMAS DAY W/FLURRIES POSSIBLE.

OVERVIEW...

VIGOROUS MID-LEVEL DISTURBANCE AND ACCOMPANYING 160 KNOT UPPER-LEVEL
JET MAX COMING ASHORE OVER THE PACIFIC NORTHWEST LATE THIS WEEKEND
WILL LEAD TO A DEEP TROUGH OVER THE MISSISSIPPI VALLEY BY MID-WEEK.
INITIAL PIECE OF ENERGY AHEAD OF THIS TROUGH IS EJECTED NORTHEAST
AND WILL LEAD TO THE DEVELOPMENT OF AN AREA OF LOW-PRESSURE OFF THE
CAROLINAS ON MONDAY. THIS WEAK FEATURE SHOULD TRACK OFFSHORE WELL
SOUTHEAST OF THE REGION ON TUESDAY PER TODAYS 12Z UKMET AND GFS...
FEEL THE NAM AND ECMWF ARE TOO FAR NORTH, SLOW, AND DEEP W/THIS
FEATURE...THUS THEY ALSO CRANK OUT TOO MUCH QPF. NEVERTHELESS...
QPF COMBINED WITH MARGINAL TEMPERATURE PROFILES OVER THE NORTHWEST
COULD SUPPORT SOME LIGHT FREEZING RAIN MONDAY NIGHT. MID-LEVEL FLOW
THEN BECOMES INCREASINGLY MERIDIONAL...PUMPING ANOMALOUSLY WARM
AND MOIST AIR UP THE EAST COAST...SETTING THE STAGE FOR HEAVY RAIN
ON CHRISTMAS EVE DAY. THE TROUGH LOOKS TO BECOME NEGATIVELY TILTED
AS IT CROSSES THE REGION...LEADING TO A STRONG FRONTAL PASSAGE LATE
WEDNESDAY INTO EARLY THURSDAY...WITH SOME FLURRIES POSSIBLE ON THE
BACK-SIDE OF THE STORM SYSTEM.

DETAILS...

MONDAY...
MID-LEVEL RIDGE CRESTS OVER THE REGION EARLY IN THE DAY...W/SURFACE
HIGH ANCHORED ALONG THE EAST COAST IN A COLD-AIR DAMMING SIGNATURE.
PRECIPITATION WILL BE LARGELY DRIVEN BY INSENTROPIC ASCENT OVER THE
COLDER LOW-LEVEL AIRMASS AND WILL BEGIN LATE IN THE DAY AS MOISTURE
STREAMS IN ALOFT AND LOW-LEVELS GRADUALLY SATURATE. THERE MAY BE A
PERIOD OF LIGHT FREEZING RAIN OVER THE NORTHWEST AS A COLD AIR
IS REINFORCED W/NORTHERLY SURFACE WINDS AND PRECIP LEADS TO
EVAPORATIONAL COOLING.

TUESDAY...
ANY LIGHT FREEZING RAIN SHOULD END EARLY IN THE MORNING WITH STRONG
WARM AIR ADVECTION ALOFT. ALTHOUGH THE BEST FORCING REMAINS WELL TO
THE WEST...BROAD ISENTROPIC ASCENT AND INCREASING MOISTURE SHOULD
LEAD TO SCATTERED RAIN SHOWERS THRU THE DAY. QPF SHOULD BE GENERALLY
LIGHT.

WEDNESDAY...
A VIGOROUS TROUGH APPROACHES FROM THE WEST W/STILL SOME SPREAD NOTED
FROM THE MEAN IN BOTH THE ECENS AND GEFS 500 HPA HEIGHT FIELDS...
INDICATING SOME DISAGREEMENT WITH REGARD TO WHAT DEGREE IT GOES
NEGATIVELY TILTED. NEVERTHELESS...A VERY DYNAMIC SYSTEM WITH SEVERAL
INGREDIENTS COMING TOGETHER FOR UP TO 1-2 INCHES OF QPF...ESPECIALLY
OVER THE HIGHER TERRAIN. NOTING A STRONG MID-LEVEL VORT MAX AND THE
LEFT-FRONT QUADRANT OF A 160 KNOT UPPER-LEVEL JET TRAVERSING THE
APPALACHIANS. ALSO NOTING STRONG WARM AIR ADVECTION AND ANOMALOUSLY
HIGH /2-3 STANDARD DEVIATION/ PRECIPITABLE WATER VALUES STREAMING
UP THE EASTERN SEABOARD. THUS THERE IS PLENTY OF MOISTURE AND
ASCENT FOR HEAVY RAINFALL...W/THE MODELS KEYING IN ON WEDNESDAY
AFTERNOON AND WEDNESDAY NIGHT FOR THE BULK OF THE PRECIP...AND
THIS WILL NEED TO BE MONITORED FOR FLOODING POTENTIAL PARTICULARLY
DUE TO THE HOLIDAY TRAVEL CHRISTMAS EVE. LATER SHIFTS WILL ALSO
NEED TO FURTHER EVALUATE THE POTENTIAL FOR GUSTY SURFACE WINDS
AND CONVECTION.

THURSDAY AND FRIDAY...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS TO
BUILD IN. TEMPERATURES WILL REMAIN ABOVE SEASONABLE LEVELS AND THERE
COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW ON THURSDAY...
PARTICULARLY NORTHWEST.

SATURDAY...ANOTHER COLD FRONT MAY APPROACH THE REGION...BUT IT/S TOO
EARLY TO SPECULATE...ESPECIALLY GIVEN THE UNCERTAINTY THAT THE STORM
SYSTEM MOVING THROUGH THE NORTHEAST CONUS MID-WEEK COULD ADD TO THE
FORECAST.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THERE HAS BEEN PLENTY OF LOW LEVEL MOISTURE TRAPPED BELOW THE
INVERSION AGAIN TODAY. CIGS WERE BETWEEN 025-035 ACROSS THE AREA
THIS AFTERNOON. THIS EVENING WE`RE SEEING MORE 030-035. STILL,
MOSTLY IN THE NORTH QUADRANT.

WE`LL KEEP THE LOW CLOUDS IN THE TERMINALS FROM KPHL NORTHWARD
THROUGH THE NIGHT. TO THE SOUTH, WE`VE SCATTERED THE LOW LEVEL
DECK OUT. A SHORT WAVE WILL BRING SOME ALTOCU TO JUST ABOUT
EVERYWHERE OVERNIGHT.

WINDS WILL REMAIN LIGHT OVERNIGHT. NO PRECIPITATION HAS BEEN
MENTIONED.

OUTLOOK...

SUNDAY NIGHT AND MONDAY MORNING...VFR.

MONDAY AFTERNOON...POTENTIAL FOR MVFR CIGS AS MARINE LAYER BECOMES
ESTABLISHED AND STRATUS ADVECTS INLAND.

MONDAY NIGHT THROUGH TUESDAY NIGHT...THE COMBINATION OF
STRENGTHENING ONSHORE FLOW AND IN-SITU CAD FROM LIGHT RAIN
OVERSPREADING THE TERMINALS COULD YIELD AN EXTENDED PERIOD OF
MVFR/IFR CONDITIONS (CIGS WOULD BE THE MORE LIKELY CONTRIBUTOR TO
IFR THAN VSBYS) MONDAY NIGHT INTO TUESDAY.

WEDNESDAY...WINDS VEER MORE OUT OF THE SOUTH AS A WARM FRONT SLOWLY
LIFTS NORTHWARD. RAIN IS EXPECTED TO BE THE MOST WIDESPREAD AND
HEAVIEST DURING THIS PART OF THE FORECAST PERIOD. PREDOMINATELY MVFR
AND IFR CONDITIONS. SOUTHERLY WINDS WILL BECOME BREEZY FOLLOWING
WARM FROPA.

WEDNESDAY NIGHT...COLD FRONT IS FORECAST TO MOVE THRU SOMETIME AT
NIGHT. LOW CLOUDS AND RAIN WILL END FROM WEST TO EAST IN WAKE OF
FROPA.

THURSDAY...WESTERLY WINDS COULD BECOME STRONG BEHIND THE FRONT
THURSDAY WITH BUFKIT FORECAST SOUNDINGS FROM THE 12Z GFS SHOWING THE
POTENTIAL FOR 30-40 KT GUSTS.

&&

.MARINE...
WEAK HIGH PRESSURE WILL REMAIN ACROSS THE WATERS TONIGHT AND SUNDAY.
WINDS AND SEAS WILL REMAIN BELOW SCA FLAG CRITERIA. WINDS WILL
MOSTLY BE NORTHERLY THROUGH THE PERIOD.

OUTLOOK...
SUNDAY NIGHT THROUGH MONDAY NIGHT...WINDS AND SEAS BELOW SCA
CRITERIA.

TUESDAY AND TUESDAY NIGHT...ONSHORE FLOW STRENGTHENS ON TUESDAY.
WINDS 15-20 KT FORECAST ON TUESDAY. SEAS ARE FORECAST TO BUILD TO
5-6 FEET TUESDAY AND TUESDAY NIGHT, WARRANTING THE NEED FOR A SCA.

WEDNESDAY AND WEDNESDAY NIGHT...SOUTHERLY WINDS STRENGTHEN AFTER
WARM FROPA. DESPITE WINDS OF 40-50 KT FORECAST 1000 FT ABOVE THE
SURFACE, THERMAL PROFILES NOT FAVORABLE FOR MIXING WITH THE SETUP OF
WARM AIR MOVING ATOP THE COOLER WATERS. EXPECTING MORE OF A HIGH END
SCA WITH 25-30 KT WINDS. WINDS FORECAST TO BECOME WESTERLY LATE
WEDNESDAY NIGHT BEHIND A COLD FRONT BUT THE CORE OF THE COLD AIR
WILL STILL REMAIN UPSTREAM OF THE WATERS. SEAS FORECAST TO INCREASE
TO 6-8 FEET.

THURSDAY...GUSTY WESTERLY WINDS EXPECTED. GALES CERTAINLY A
POSSIBILITY.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...O`HARA
SHORT TERM...O`HARA
LONG TERM...FRANCK
AVIATION...FRANCK/KLEIN/O`HARA
MARINE...KLEIN/O`HARA







000
FXUS61 KPHI 210216
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
916 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY BUILD SOUTHWESTWARD INTO THE REGION
FROM ATLANTIC CANADA THROUGH MONDAY. LOW PRESSURE WILL ORGANIZE
OFF THE CAROLINAS MONDAY NIGHT AND MOVE NORTHEASTWARD OFFSHORE ON
TUESDAY. MEANWHILE...ANOTHER AREA OF LOW PRESSURE WILL DEVELOP
OVER THE OHIO VALLEY AND MOVE NORTHWARD INTO QUEBEC...LEADING TO A
STRONG COLD FRONTAL PASSAGE ON THURSDAY NIGHT. HIGH PRESSURE WILL
BUILD IN ON FRIDAY AND A WEAKER COLD FRONT MAY APPROACH THE REGION
NEXT WEEKEND.

&&

.NEAR TERM /THROUGH SUNDAY/...
WEAK SURFACE HIGH PRESSURE WILL REMAIN ACROSS THE AREA TONIGHT.
PLENTY OF MOISTURE REMAINS TRAPPED BELOW A LOW LEVEL INVERSION,
ESPECIALLY PHILLY NORTH. THE LOW CLOUDS HAVE BROKEN UP SOUTH OF
PHILLY, BUT SKIES WILL FILL UP AGAIN AS A MID-LEVEL DECK ADVECTS
IN OVERNIGHT. THESE CLOUDS ARE ASSOCIATED WITH A MID-LEVEL SHORT
WAVE.

THE HIGH RESOLUTION MODELS KEEP THE CWA PRECIP-FREE(MEASURABLE)
THROUGH THE OVERNIGHT AS DOES THE LOWER RES MODELS. WE`LL KEEP THE
GRIDS AS IS, BUT CAN`T RULE OUT A FLURRY OR TWO UP ACROSS THE
NORTHERN THIRD OF THE CWA.

ANOTHER SEASONABLY COLD NIGHT IS EXPECTED WITH LOWS IN THE LOW 20S
NORTH AND MID OR UPPER 20S SOUTH. WINDS WILL BE LIGHT FROM THE
NORTH.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH 6 PM SUNDAY/...
AFTER A WEAK SHORTWAVE CROSSES THE AREA SUN MORNING...UPPER RIDGING
WILL TAKE PLACE. THIS WILL HOPEFULLY ALLOW MORE SUNSHINE ACROSS THE
AREA. WE HAVE WRITTEN A PARTLY TO MOSTLY SUNNY FCST FOR NOW. WE HELD
ONTO SOME EXTRA CLOUD COVER ACROSS THE SRN POCONOS HOWEVER. HIGH
TEMPERATURES SUNDAY WILL RISE INTO THE LOW 40S ACROSS SRN NJ AND THE
DELMARVA...WHILE READINGS HOLD IN THE MID/UPPER 30S ACROSS THE
NORTH/WEST AREAS. WINDS WILL REMAIN LIGHT...MOSTLY FROM THE NORTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...

* FREEZING RAIN POSSIBLE MONDAY NIGHT OVER THE NORTHWEST.
* INCREASING POTENTIAL FOR HEAVY RAIN CHRISTMAS EVE WITH
  TEMPERATURES WELL ABOVE NORMAL.
* BRISK WESTERLY WIND CHRISTMAS DAY W/FLURRIES POSSIBLE.

OVERVIEW...

VIGOROUS MID-LEVEL DISTURBANCE AND ACCOMPANYING 160 KNOT UPPER-LEVEL
JET MAX COMING ASHORE OVER THE PACIFIC NORTHWEST LATE THIS WEEKEND
WILL LEAD TO A DEEP TROUGH OVER THE MISSISSIPPI VALLEY BY MID-WEEK.
INITIAL PIECE OF ENERGY AHEAD OF THIS TROUGH IS EJECTED NORTHEAST
AND WILL LEAD TO THE DEVELOPMENT OF AN AREA OF LOW-PRESSURE OFF THE
CAROLINAS ON MONDAY. THIS WEAK FEATURE SHOULD TRACK OFFSHORE WELL
SOUTHEAST OF THE REGION ON TUESDAY PER TODAYS 12Z UKMET AND GFS...
FEEL THE NAM AND ECMWF ARE TOO FAR NORTH, SLOW, AND DEEP W/THIS
FEATURE...THUS THEY ALSO CRANK OUT TOO MUCH QPF. NEVERTHELESS...
QPF COMBINED WITH MARGINAL TEMPERATURE PROFILES OVER THE NORTHWEST
COULD SUPPORT SOME LIGHT FREEZING RAIN MONDAY NIGHT. MID-LEVEL FLOW
THEN BECOMES INCREASINGLY MERIDIONAL...PUMPING ANOMALOUSLY WARM
AND MOIST AIR UP THE EAST COAST...SETTING THE STAGE FOR HEAVY RAIN
ON CHRISTMAS EVE DAY. THE TROUGH LOOKS TO BECOME NEGATIVELY TILTED
AS IT CROSSES THE REGION...LEADING TO A STRONG FRONTAL PASSAGE LATE
WEDNESDAY INTO EARLY THURSDAY...WITH SOME FLURRIES POSSIBLE ON THE
BACK-SIDE OF THE STORM SYSTEM.

DETAILS...

MONDAY...
MID-LEVEL RIDGE CRESTS OVER THE REGION EARLY IN THE DAY...W/SURFACE
HIGH ANCHORED ALONG THE EAST COAST IN A COLD-AIR DAMMING SIGNATURE.
PRECIPITATION WILL BE LARGELY DRIVEN BY INSENTROPIC ASCENT OVER THE
COLDER LOW-LEVEL AIRMASS AND WILL BEGIN LATE IN THE DAY AS MOISTURE
STREAMS IN ALOFT AND LOW-LEVELS GRADUALLY SATURATE. THERE MAY BE A
PERIOD OF LIGHT FREEZING RAIN OVER THE NORTHWEST AS A COLD AIR
IS REINFORCED W/NORTHERLY SURFACE WINDS AND PRECIP LEADS TO
EVAPORATIONAL COOLING.

TUESDAY...
ANY LIGHT FREEZING RAIN SHOULD END EARLY IN THE MORNING WITH STRONG
WARM AIR ADVECTION ALOFT. ALTHOUGH THE BEST FORCING REMAINS WELL TO
THE WEST...BROAD ISENTROPIC ASCENT AND INCREASING MOISTURE SHOULD
LEAD TO SCATTERED RAIN SHOWERS THRU THE DAY. QPF SHOULD BE GENERALLY
LIGHT.

WEDNESDAY...
A VIGOROUS TROUGH APPROACHES FROM THE WEST W/STILL SOME SPREAD NOTED
FROM THE MEAN IN BOTH THE ECENS AND GEFS 500 HPA HEIGHT FIELDS...
INDICATING SOME DISAGREEMENT WITH REGARD TO WHAT DEGREE IT GOES
NEGATIVELY TILTED. NEVERTHELESS...A VERY DYNAMIC SYSTEM WITH SEVERAL
INGREDIENTS COMING TOGETHER FOR UP TO 1-2 INCHES OF QPF...ESPECIALLY
OVER THE HIGHER TERRAIN. NOTING A STRONG MID-LEVEL VORT MAX AND THE
LEFT-FRONT QUADRANT OF A 160 KNOT UPPER-LEVEL JET TRAVERSING THE
APPALACHIANS. ALSO NOTING STRONG WARM AIR ADVECTION AND ANOMALOUSLY
HIGH /2-3 STANDARD DEVIATION/ PRECIPITABLE WATER VALUES STREAMING
UP THE EASTERN SEABOARD. THUS THERE IS PLENTY OF MOISTURE AND
ASCENT FOR HEAVY RAINFALL...W/THE MODELS KEYING IN ON WEDNESDAY
AFTERNOON AND WEDNESDAY NIGHT FOR THE BULK OF THE PRECIP...AND
THIS WILL NEED TO BE MONITORED FOR FLOODING POTENTIAL PARTICULARLY
DUE TO THE HOLIDAY TRAVEL CHRISTMAS EVE. LATER SHIFTS WILL ALSO
NEED TO FURTHER EVALUATE THE POTENTIAL FOR GUSTY SURFACE WINDS
AND CONVECTION.

THURSDAY AND FRIDAY...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS TO
BUILD IN. TEMPERATURES WILL REMAIN ABOVE SEASONABLE LEVELS AND THERE
COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW ON THURSDAY...
PARTICULARLY NORTHWEST.

SATURDAY...ANOTHER COLD FRONT MAY APPROACH THE REGION...BUT IT/S TOO
EARLY TO SPECULATE...ESPECIALLY GIVEN THE UNCERTAINTY THAT THE STORM
SYSTEM MOVING THROUGH THE NORTHEAST CONUS MID-WEEK COULD ADD TO THE
FORECAST.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THERE HAS BEEN PLENTY OF LOW LEVEL MOISTURE TRAPPED BELOW THE
INVERSION AGAIN TODAY. CIGS WERE BETWEEN 025-035 ACROSS THE AREA
THIS AFTERNOON. THIS EVENING WE`RE SEEING MORE 030-035. STILL,
MOSTLY IN THE NORTH QUADRANT.

WE`LL KEEP THE LOW CLOUDS IN THE TERMINALS FROM KPHL NORTHWARD
THROUGH THE NIGHT. TO THE SOUTH, WE`VE SCATTERED THE LOW LEVEL
DECK OUT. A SHORT WAVE WILL BRING SOME ALTOCU TO JUST ABOUT
EVERYWHERE OVERNIGHT.

WINDS WILL REMAIN LIGHT OVERNIGHT. NO PRECIPITATION HAS BEEN
MENTIONED.

OUTLOOK...

SUNDAY NIGHT AND MONDAY MORNING...VFR.

MONDAY AFTERNOON...POTENTIAL FOR MVFR CIGS AS MARINE LAYER BECOMES
ESTABLISHED AND STRATUS ADVECTS INLAND.

MONDAY NIGHT THROUGH TUESDAY NIGHT...THE COMBINATION OF
STRENGTHENING ONSHORE FLOW AND IN-SITU CAD FROM LIGHT RAIN
OVERSPREADING THE TERMINALS COULD YIELD AN EXTENDED PERIOD OF
MVFR/IFR CONDITIONS (CIGS WOULD BE THE MORE LIKELY CONTRIBUTOR TO
IFR THAN VSBYS) MONDAY NIGHT INTO TUESDAY.

WEDNESDAY...WINDS VEER MORE OUT OF THE SOUTH AS A WARM FRONT SLOWLY
LIFTS NORTHWARD. RAIN IS EXPECTED TO BE THE MOST WIDESPREAD AND
HEAVIEST DURING THIS PART OF THE FORECAST PERIOD. PREDOMINATELY MVFR
AND IFR CONDITIONS. SOUTHERLY WINDS WILL BECOME BREEZY FOLLOWING
WARM FROPA.

WEDNESDAY NIGHT...COLD FRONT IS FORECAST TO MOVE THRU SOMETIME AT
NIGHT. LOW CLOUDS AND RAIN WILL END FROM WEST TO EAST IN WAKE OF
FROPA.

THURSDAY...WESTERLY WINDS COULD BECOME STRONG BEHIND THE FRONT
THURSDAY WITH BUFKIT FORECAST SOUNDINGS FROM THE 12Z GFS SHOWING THE
POTENTIAL FOR 30-40 KT GUSTS.

&&

.MARINE...
WEAK HIGH PRESSURE WILL REMAIN ACROSS THE WATERS TONIGHT AND SUNDAY.
WINDS AND SEAS WILL REMAIN BELOW SCA FLAG CRITERIA. WINDS WILL
MOSTLY BE NORTHERLY THROUGH THE PERIOD.

OUTLOOK...
SUNDAY NIGHT THROUGH MONDAY NIGHT...WINDS AND SEAS BELOW SCA
CRITERIA.

TUESDAY AND TUESDAY NIGHT...ONSHORE FLOW STRENGTHENS ON TUESDAY.
WINDS 15-20 KT FORECAST ON TUESDAY. SEAS ARE FORECAST TO BUILD TO
5-6 FEET TUESDAY AND TUESDAY NIGHT, WARRANTING THE NEED FOR A SCA.

WEDNESDAY AND WEDNESDAY NIGHT...SOUTHERLY WINDS STRENGTHEN AFTER
WARM FROPA. DESPITE WINDS OF 40-50 KT FORECAST 1000 FT ABOVE THE
SURFACE, THERMAL PROFILES NOT FAVORABLE FOR MIXING WITH THE SETUP OF
WARM AIR MOVING ATOP THE COOLER WATERS. EXPECTING MORE OF A HIGH END
SCA WITH 25-30 KT WINDS. WINDS FORECAST TO BECOME WESTERLY LATE
WEDNESDAY NIGHT BEHIND A COLD FRONT BUT THE CORE OF THE COLD AIR
WILL STILL REMAIN UPSTREAM OF THE WATERS. SEAS FORECAST TO INCREASE
TO 6-8 FEET.

THURSDAY...GUSTY WESTERLY WINDS EXPECTED. GALES CERTAINLY A
POSSIBILITY.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...O`HARA
SHORT TERM...O`HARA
LONG TERM...FRANCK
AVIATION...FRANCK/KLEIN/O`HARA
MARINE...KLEIN/O`HARA







000
FXUS61 KLWX 210140 AAA
AFDLWX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
840 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST INTO EARLY NEXT WEEK. LOW PRESSURE WILL
TRACK UP THE MID-ATLANTIC COAST LATE MONDAY. A STRONG COLD FRONT
WILL THEN PASS THROUGH THE AREA LATE WEDNESDAY INTO WEDNESDAY
NIGHT.

&&

.NEAR TERM /THROUGH SUNDAY/...
A COUPLE OF MINOR KINKS IN THE UPPER FLOW WILL MAKE THEIR WAY OVER
THE REGION IN THE COMING HRS. THE FIRST UPPER WAVE NOW SLIDING
OVERHEAD...BRINGING ESSENTIALLY A DENSE MID-STRATUS DECK. AT THE
SFC...MANY OB SITES W/ CALM WINDS WHICH WILL CARRY OVER INTO THE
DAYTIME HRS ON SUNDAY. THE OTHER WAVE IS RIGHT ON THE HEELS OF THE
CURRENT ONE...BOTH WILL SLOWLY DISSIPATE HEADING INTO THE
OVERNIGHT PERIOD AS THEY APPROACH THE ATLC COASTLINE.

TEMPS CONTINUE TO HOVER NEAR FREEZING ACROSS THE AREA AND WILL
SLOWLY SLIP DOWN INTO THE 20S OVERNIGHT. DEWPOINTS ALSO STAYING
THE SAME GENERAL RANGE FOR A LONG STRETCH OF TIME...GENERALLY IN
THE L-M20S WHICH WILL KEEP OUR OVERNIGHT LOWS JUST ABOVE THAT BY
THE PREDAWN HRS. SKIES WILL REMAIN CLOUDY/MOSTLY CLOUDY
OVERNIGHT...ALSO KEEPING TEMPS FROM DROPPING MUCH FURTHER W/ THE
INSULATING EFFECT. LEANED TOWARD THE BIAS-CORRECTED VERSION OF MAV
GUIDANCE FOR LOWS.

BEHIND THE UPPER WAVES...ZONAL UPPER FLOW AGAIN ENCOMPASSES THE
UPPER MIDWEST AND BUILDS IN A LARGE AREA OF HIGH PRESSURE. THIS
FEATURE WILL BUILD INTO THE REGION OVER THE COURSE OF THE DAY ON
SUNDAY...ALLOWING FOR MOSTLY CLEAR TO PARTLY CLOUDY SKIES W/ NOT
MUCH ADVECTION OF ANY KIND WE WILL STAY SEASONABLY CHILLY. WINDS
WILL STAY LIGHT AS THE CENTER OF HIGH ROLLS OVERHEAD.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
UPPER TROUGH WILL BEGIN TO AMPLIFY OVER THE EASTERN U.S ON MONDAY.
UPPER LEVEL JET/DYNAMICS SHIFT EAST TO THE COAST WHERE AN AREA OF
LOW PRESSURE IS LIKELY TO DEVELOP OVER THE CAROLINAS AND TRACK
SLOWLY NORTH INTO MONDAY NIGHT. TIMING OF PRECIPITATION IS STILL A
BIT UNCERTAIN WITHIN THE NAM/GFS/EURO SOLUTIONS WITH THE NAM BEING
THE MOST BULLISH AND QUICKEST TO ARRIVE VS THE SLOWER GFS AND EURO.
EITHER WAY...TEMPERATURES WILL BE CRUCIAL WITH COLD HIGH PRESSURE
OVER NEW ENGLAND PROVIDING CAD WEDGE OVER THE MIDDLE ATLANTIC TO
START THE EVENT.

IF PRECIPITATION BEGINS EARLIER IN THE DAY AS PER THE 12Z NAM
THERE COULD BE MORE OF AN ZR/IP THREAT EVEN OVER SOME OF THE
IMMEDIATE SUBURBS NORTH AND WEST OF DC/BWI THE FIRST PART OF
MONDAY. IT IS TYPICAL FOR GUIDANCE TO ERODE THE CAD WEDGE TOO
QUICKLY IN SITUATIONS LIKE THIS. HAVE UNDERCUT TEMPERATURES A FEW
DEGREES FROM INHERITED NUMBERS AND EXPANDED ZR/IP A BIT EAST AS
WELL. MILDER AIR WILL GRADUALLY CHANGE THE ICE TO RAIN EAST OF THE
BLUE RIDGE BUT A LONGER PERIOD OF ZR/IP MAY OCCUR WEST OF THE BLUE
RIDGE IN THE NORMALLY COLDER LOCALES. WILL CONTINUE TO HIGHLIGHT
POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK.

ENOUGH WARMER AIR SHOULD WORK IN AND CHANGE MUCH OF THE PRECIP TO
RAIN MONDAY NIGHT ALTHOUGH THERE COULD STILL BE A FEW POCKETS OF ZR
OVER THE HIGHER ELEVATIONS WITHIN THE HIGHLANDS.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
A WARM FRONT WILL INCH ITS WAY NORTHWARD FROM THE CAROLINAS TO THE
MID ATLANTIC COAST TUESDAY AND TUESDAY NIGHT. SOME STRATIFORM LIGHT
TO MODERATE RAIN WILL PRECEDE THE WARM FRONT AND OVERRUN THE ENTIRE
REGION.

THROUGH THE DAY WEDNESDAY...AS THE WARM FRONT WORKS ITS WAY NORTH OF
THE MASON-DIXON LINE...A POTENT STORM SYSTEM WILL BE PIVOTING
NORTHEASTWARD FROM THE OHIO VALLEY INTO THE EASTERN GREAT LAKES
REGION. ITS ASSOCIATED COLD FRONT WILL TRAIL SOUTHWARD AND POSSIBLY
WORK INTO THE POTOMAC HIGHLANDS AND SHENANDOAH VALLEY BY LATER IN
THE DAY WEDNESDAY. THIS COLD FRONT SHOULD MOVE ACROSS THE DELMARVA
PENINSULA AND THEN OFFSHORE WEDNESDAY NIGHT. PROBABILITY OF RAIN
REMAINS HIGH...NEAR 90 TO 100 PERCENT. THE RAIN EXPECTED LOOKS TO BE
MORE CONVECTIVE IN NATURE AHEAD OF THE COLD FRONT AND POTENT STORM
SYSTEM.

HIGH TEMPERATURES WEDNESDAY WILL BE 15 TO 20 DEGREES ABOVE NORMAL AS
WE ENCOUNTER MOST LOCATIONS REACHING NEAR 60 TO THE LOWER 60S...MAINLY
EAST OF THE BLUE RIDGE MOUNTAINS. WE WILL LEAVE A CHANCE OF RAIN
SHOWERS IN THE FORECAST FOR WEDNESDAY NIGHT CONSIDERING SOME UNCERTAINTY
ON THE TIMING OF COLD FRONTAL PASSAGE. NONETHELESS...COLDER AND DRIER
AIR WILL FILTER INTO THE REGION FROM WEST TO EAST WEDNESDAY
NIGHT...ALLOWING FOR TEMPERATURES TO QUICKLY FALL THROUGH THE 50S
INTO THE 40S.

THERE IS A CHANCE FOR SOME SNOW SHOWERS IN THE HIGHER ELEVATIONS OF
THE POTOMAC HIGHLANDS THURSDAY...PERHAPS ABOVE 2500 FEET. ALTHOUGH
TEMPERATURES WILL BE SOME 10 TO 15 COOLER THAN WEDNESDAY...TEMPERATURES
WILL STILL BE SLIGHTLY ABOVE NORMAL.

DRY CONDITIONS FRIDAY WITH HIGH PRESSURE BUILDING JUST TO OUR SOUTH.
HIGH TEMPERATURES MAY STILL BE SLIGHTLY ABOVE NORMAL WITH A GOOD BIT
OF SUNSHINE.

ANOTHER COLD FRONT COULD BRING A CHANCE FOR RAIN AND SNOW SHOWERS TO
THE REGION FRIDAY NIGHT INTO SATURDAY.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS THROUGH SUNDAY...BRINGING
VFR CONDITIONS. CLOUDS WILL INCREASE SUNDAY NIGHT AND SUBVFR CONDITIONS
ARE POSSIBLE TOWARD MONDAY MORNING.

CONDITIONS WILL DETERIORATE MONDAY INTO MONDAY NIGHT WITH SUB VFR
CIGS AND VSBYS. PRECIPITATION TYPE IS A BIT UNCERTAIN ALTHOUGH
EXPECTING MOSTLY LIQUID AT KDCA AND KBWI. NORTH AND WEST COULD SEE A
WINTRY MIX OF FREEZING RAIN AND SLEET FOR PART OF MONDAY. ALL RAIN
EXPECTED MONDAY NIGHT.

IFR OR LIFR CONDITIONS ARE POSSIBLE TUESDAY AND TUESDAY NIGHT
WITH LOW CLOUDS AND PERIODS OF RAIN. WINDS LIGHT AND VARIABLE. IFR
OR LIFR CONDITIONS ARE POSSIBLE AGAIN WEDNESDAY WITH NUMEROUS
GUSTY RAIN SHOWERS AHEAD OF A COLD FRONT. WINDS SOUTHEAST TO SOUTH
5 TO 10 KNOTS WEDNESDAY...INCREASING SOUTHWEST WEDNESDAY NIGHT.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS THROUGH SUNDAY NIGHT. NO
MARINE HAZARDS ARE EXPECTED DURING THIS TIME.

WINDS COULD APPROACH SCA CRITERIA LATER MONDAY INTO EARLY TUESDAY AS
LOW PRESSURE APPROACHES FROM THE SOUTH.

NO MARINE HAZARDS TUESDAY AND TUESDAY NIGHT. SMALL CRAFT ADVISORIES
MAY BE NEEDED WEDNESDAY WITH GUSTS TO 20 KNOTS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
UPDATE...GMS
PREV DISCUSSION...BJL/KRW/KLW







000
FXUS61 KLWX 210140 AAA
AFDLWX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
840 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST INTO EARLY NEXT WEEK. LOW PRESSURE WILL
TRACK UP THE MID-ATLANTIC COAST LATE MONDAY. A STRONG COLD FRONT
WILL THEN PASS THROUGH THE AREA LATE WEDNESDAY INTO WEDNESDAY
NIGHT.

&&

.NEAR TERM /THROUGH SUNDAY/...
A COUPLE OF MINOR KINKS IN THE UPPER FLOW WILL MAKE THEIR WAY OVER
THE REGION IN THE COMING HRS. THE FIRST UPPER WAVE NOW SLIDING
OVERHEAD...BRINGING ESSENTIALLY A DENSE MID-STRATUS DECK. AT THE
SFC...MANY OB SITES W/ CALM WINDS WHICH WILL CARRY OVER INTO THE
DAYTIME HRS ON SUNDAY. THE OTHER WAVE IS RIGHT ON THE HEELS OF THE
CURRENT ONE...BOTH WILL SLOWLY DISSIPATE HEADING INTO THE
OVERNIGHT PERIOD AS THEY APPROACH THE ATLC COASTLINE.

TEMPS CONTINUE TO HOVER NEAR FREEZING ACROSS THE AREA AND WILL
SLOWLY SLIP DOWN INTO THE 20S OVERNIGHT. DEWPOINTS ALSO STAYING
THE SAME GENERAL RANGE FOR A LONG STRETCH OF TIME...GENERALLY IN
THE L-M20S WHICH WILL KEEP OUR OVERNIGHT LOWS JUST ABOVE THAT BY
THE PREDAWN HRS. SKIES WILL REMAIN CLOUDY/MOSTLY CLOUDY
OVERNIGHT...ALSO KEEPING TEMPS FROM DROPPING MUCH FURTHER W/ THE
INSULATING EFFECT. LEANED TOWARD THE BIAS-CORRECTED VERSION OF MAV
GUIDANCE FOR LOWS.

BEHIND THE UPPER WAVES...ZONAL UPPER FLOW AGAIN ENCOMPASSES THE
UPPER MIDWEST AND BUILDS IN A LARGE AREA OF HIGH PRESSURE. THIS
FEATURE WILL BUILD INTO THE REGION OVER THE COURSE OF THE DAY ON
SUNDAY...ALLOWING FOR MOSTLY CLEAR TO PARTLY CLOUDY SKIES W/ NOT
MUCH ADVECTION OF ANY KIND WE WILL STAY SEASONABLY CHILLY. WINDS
WILL STAY LIGHT AS THE CENTER OF HIGH ROLLS OVERHEAD.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
UPPER TROUGH WILL BEGIN TO AMPLIFY OVER THE EASTERN U.S ON MONDAY.
UPPER LEVEL JET/DYNAMICS SHIFT EAST TO THE COAST WHERE AN AREA OF
LOW PRESSURE IS LIKELY TO DEVELOP OVER THE CAROLINAS AND TRACK
SLOWLY NORTH INTO MONDAY NIGHT. TIMING OF PRECIPITATION IS STILL A
BIT UNCERTAIN WITHIN THE NAM/GFS/EURO SOLUTIONS WITH THE NAM BEING
THE MOST BULLISH AND QUICKEST TO ARRIVE VS THE SLOWER GFS AND EURO.
EITHER WAY...TEMPERATURES WILL BE CRUCIAL WITH COLD HIGH PRESSURE
OVER NEW ENGLAND PROVIDING CAD WEDGE OVER THE MIDDLE ATLANTIC TO
START THE EVENT.

IF PRECIPITATION BEGINS EARLIER IN THE DAY AS PER THE 12Z NAM
THERE COULD BE MORE OF AN ZR/IP THREAT EVEN OVER SOME OF THE
IMMEDIATE SUBURBS NORTH AND WEST OF DC/BWI THE FIRST PART OF
MONDAY. IT IS TYPICAL FOR GUIDANCE TO ERODE THE CAD WEDGE TOO
QUICKLY IN SITUATIONS LIKE THIS. HAVE UNDERCUT TEMPERATURES A FEW
DEGREES FROM INHERITED NUMBERS AND EXPANDED ZR/IP A BIT EAST AS
WELL. MILDER AIR WILL GRADUALLY CHANGE THE ICE TO RAIN EAST OF THE
BLUE RIDGE BUT A LONGER PERIOD OF ZR/IP MAY OCCUR WEST OF THE BLUE
RIDGE IN THE NORMALLY COLDER LOCALES. WILL CONTINUE TO HIGHLIGHT
POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK.

ENOUGH WARMER AIR SHOULD WORK IN AND CHANGE MUCH OF THE PRECIP TO
RAIN MONDAY NIGHT ALTHOUGH THERE COULD STILL BE A FEW POCKETS OF ZR
OVER THE HIGHER ELEVATIONS WITHIN THE HIGHLANDS.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
A WARM FRONT WILL INCH ITS WAY NORTHWARD FROM THE CAROLINAS TO THE
MID ATLANTIC COAST TUESDAY AND TUESDAY NIGHT. SOME STRATIFORM LIGHT
TO MODERATE RAIN WILL PRECEDE THE WARM FRONT AND OVERRUN THE ENTIRE
REGION.

THROUGH THE DAY WEDNESDAY...AS THE WARM FRONT WORKS ITS WAY NORTH OF
THE MASON-DIXON LINE...A POTENT STORM SYSTEM WILL BE PIVOTING
NORTHEASTWARD FROM THE OHIO VALLEY INTO THE EASTERN GREAT LAKES
REGION. ITS ASSOCIATED COLD FRONT WILL TRAIL SOUTHWARD AND POSSIBLY
WORK INTO THE POTOMAC HIGHLANDS AND SHENANDOAH VALLEY BY LATER IN
THE DAY WEDNESDAY. THIS COLD FRONT SHOULD MOVE ACROSS THE DELMARVA
PENINSULA AND THEN OFFSHORE WEDNESDAY NIGHT. PROBABILITY OF RAIN
REMAINS HIGH...NEAR 90 TO 100 PERCENT. THE RAIN EXPECTED LOOKS TO BE
MORE CONVECTIVE IN NATURE AHEAD OF THE COLD FRONT AND POTENT STORM
SYSTEM.

HIGH TEMPERATURES WEDNESDAY WILL BE 15 TO 20 DEGREES ABOVE NORMAL AS
WE ENCOUNTER MOST LOCATIONS REACHING NEAR 60 TO THE LOWER 60S...MAINLY
EAST OF THE BLUE RIDGE MOUNTAINS. WE WILL LEAVE A CHANCE OF RAIN
SHOWERS IN THE FORECAST FOR WEDNESDAY NIGHT CONSIDERING SOME UNCERTAINTY
ON THE TIMING OF COLD FRONTAL PASSAGE. NONETHELESS...COLDER AND DRIER
AIR WILL FILTER INTO THE REGION FROM WEST TO EAST WEDNESDAY
NIGHT...ALLOWING FOR TEMPERATURES TO QUICKLY FALL THROUGH THE 50S
INTO THE 40S.

THERE IS A CHANCE FOR SOME SNOW SHOWERS IN THE HIGHER ELEVATIONS OF
THE POTOMAC HIGHLANDS THURSDAY...PERHAPS ABOVE 2500 FEET. ALTHOUGH
TEMPERATURES WILL BE SOME 10 TO 15 COOLER THAN WEDNESDAY...TEMPERATURES
WILL STILL BE SLIGHTLY ABOVE NORMAL.

DRY CONDITIONS FRIDAY WITH HIGH PRESSURE BUILDING JUST TO OUR SOUTH.
HIGH TEMPERATURES MAY STILL BE SLIGHTLY ABOVE NORMAL WITH A GOOD BIT
OF SUNSHINE.

ANOTHER COLD FRONT COULD BRING A CHANCE FOR RAIN AND SNOW SHOWERS TO
THE REGION FRIDAY NIGHT INTO SATURDAY.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS THROUGH SUNDAY...BRINGING
VFR CONDITIONS. CLOUDS WILL INCREASE SUNDAY NIGHT AND SUBVFR CONDITIONS
ARE POSSIBLE TOWARD MONDAY MORNING.

CONDITIONS WILL DETERIORATE MONDAY INTO MONDAY NIGHT WITH SUB VFR
CIGS AND VSBYS. PRECIPITATION TYPE IS A BIT UNCERTAIN ALTHOUGH
EXPECTING MOSTLY LIQUID AT KDCA AND KBWI. NORTH AND WEST COULD SEE A
WINTRY MIX OF FREEZING RAIN AND SLEET FOR PART OF MONDAY. ALL RAIN
EXPECTED MONDAY NIGHT.

IFR OR LIFR CONDITIONS ARE POSSIBLE TUESDAY AND TUESDAY NIGHT
WITH LOW CLOUDS AND PERIODS OF RAIN. WINDS LIGHT AND VARIABLE. IFR
OR LIFR CONDITIONS ARE POSSIBLE AGAIN WEDNESDAY WITH NUMEROUS
GUSTY RAIN SHOWERS AHEAD OF A COLD FRONT. WINDS SOUTHEAST TO SOUTH
5 TO 10 KNOTS WEDNESDAY...INCREASING SOUTHWEST WEDNESDAY NIGHT.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS THROUGH SUNDAY NIGHT. NO
MARINE HAZARDS ARE EXPECTED DURING THIS TIME.

WINDS COULD APPROACH SCA CRITERIA LATER MONDAY INTO EARLY TUESDAY AS
LOW PRESSURE APPROACHES FROM THE SOUTH.

NO MARINE HAZARDS TUESDAY AND TUESDAY NIGHT. SMALL CRAFT ADVISORIES
MAY BE NEEDED WEDNESDAY WITH GUSTS TO 20 KNOTS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
UPDATE...GMS
PREV DISCUSSION...BJL/KRW/KLW







000
FXUS61 KLWX 210140 AAA
AFDLWX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
840 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST INTO EARLY NEXT WEEK. LOW PRESSURE WILL
TRACK UP THE MID-ATLANTIC COAST LATE MONDAY. A STRONG COLD FRONT
WILL THEN PASS THROUGH THE AREA LATE WEDNESDAY INTO WEDNESDAY
NIGHT.

&&

.NEAR TERM /THROUGH SUNDAY/...
A COUPLE OF MINOR KINKS IN THE UPPER FLOW WILL MAKE THEIR WAY OVER
THE REGION IN THE COMING HRS. THE FIRST UPPER WAVE NOW SLIDING
OVERHEAD...BRINGING ESSENTIALLY A DENSE MID-STRATUS DECK. AT THE
SFC...MANY OB SITES W/ CALM WINDS WHICH WILL CARRY OVER INTO THE
DAYTIME HRS ON SUNDAY. THE OTHER WAVE IS RIGHT ON THE HEELS OF THE
CURRENT ONE...BOTH WILL SLOWLY DISSIPATE HEADING INTO THE
OVERNIGHT PERIOD AS THEY APPROACH THE ATLC COASTLINE.

TEMPS CONTINUE TO HOVER NEAR FREEZING ACROSS THE AREA AND WILL
SLOWLY SLIP DOWN INTO THE 20S OVERNIGHT. DEWPOINTS ALSO STAYING
THE SAME GENERAL RANGE FOR A LONG STRETCH OF TIME...GENERALLY IN
THE L-M20S WHICH WILL KEEP OUR OVERNIGHT LOWS JUST ABOVE THAT BY
THE PREDAWN HRS. SKIES WILL REMAIN CLOUDY/MOSTLY CLOUDY
OVERNIGHT...ALSO KEEPING TEMPS FROM DROPPING MUCH FURTHER W/ THE
INSULATING EFFECT. LEANED TOWARD THE BIAS-CORRECTED VERSION OF MAV
GUIDANCE FOR LOWS.

BEHIND THE UPPER WAVES...ZONAL UPPER FLOW AGAIN ENCOMPASSES THE
UPPER MIDWEST AND BUILDS IN A LARGE AREA OF HIGH PRESSURE. THIS
FEATURE WILL BUILD INTO THE REGION OVER THE COURSE OF THE DAY ON
SUNDAY...ALLOWING FOR MOSTLY CLEAR TO PARTLY CLOUDY SKIES W/ NOT
MUCH ADVECTION OF ANY KIND WE WILL STAY SEASONABLY CHILLY. WINDS
WILL STAY LIGHT AS THE CENTER OF HIGH ROLLS OVERHEAD.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
UPPER TROUGH WILL BEGIN TO AMPLIFY OVER THE EASTERN U.S ON MONDAY.
UPPER LEVEL JET/DYNAMICS SHIFT EAST TO THE COAST WHERE AN AREA OF
LOW PRESSURE IS LIKELY TO DEVELOP OVER THE CAROLINAS AND TRACK
SLOWLY NORTH INTO MONDAY NIGHT. TIMING OF PRECIPITATION IS STILL A
BIT UNCERTAIN WITHIN THE NAM/GFS/EURO SOLUTIONS WITH THE NAM BEING
THE MOST BULLISH AND QUICKEST TO ARRIVE VS THE SLOWER GFS AND EURO.
EITHER WAY...TEMPERATURES WILL BE CRUCIAL WITH COLD HIGH PRESSURE
OVER NEW ENGLAND PROVIDING CAD WEDGE OVER THE MIDDLE ATLANTIC TO
START THE EVENT.

IF PRECIPITATION BEGINS EARLIER IN THE DAY AS PER THE 12Z NAM
THERE COULD BE MORE OF AN ZR/IP THREAT EVEN OVER SOME OF THE
IMMEDIATE SUBURBS NORTH AND WEST OF DC/BWI THE FIRST PART OF
MONDAY. IT IS TYPICAL FOR GUIDANCE TO ERODE THE CAD WEDGE TOO
QUICKLY IN SITUATIONS LIKE THIS. HAVE UNDERCUT TEMPERATURES A FEW
DEGREES FROM INHERITED NUMBERS AND EXPANDED ZR/IP A BIT EAST AS
WELL. MILDER AIR WILL GRADUALLY CHANGE THE ICE TO RAIN EAST OF THE
BLUE RIDGE BUT A LONGER PERIOD OF ZR/IP MAY OCCUR WEST OF THE BLUE
RIDGE IN THE NORMALLY COLDER LOCALES. WILL CONTINUE TO HIGHLIGHT
POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK.

ENOUGH WARMER AIR SHOULD WORK IN AND CHANGE MUCH OF THE PRECIP TO
RAIN MONDAY NIGHT ALTHOUGH THERE COULD STILL BE A FEW POCKETS OF ZR
OVER THE HIGHER ELEVATIONS WITHIN THE HIGHLANDS.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
A WARM FRONT WILL INCH ITS WAY NORTHWARD FROM THE CAROLINAS TO THE
MID ATLANTIC COAST TUESDAY AND TUESDAY NIGHT. SOME STRATIFORM LIGHT
TO MODERATE RAIN WILL PRECEDE THE WARM FRONT AND OVERRUN THE ENTIRE
REGION.

THROUGH THE DAY WEDNESDAY...AS THE WARM FRONT WORKS ITS WAY NORTH OF
THE MASON-DIXON LINE...A POTENT STORM SYSTEM WILL BE PIVOTING
NORTHEASTWARD FROM THE OHIO VALLEY INTO THE EASTERN GREAT LAKES
REGION. ITS ASSOCIATED COLD FRONT WILL TRAIL SOUTHWARD AND POSSIBLY
WORK INTO THE POTOMAC HIGHLANDS AND SHENANDOAH VALLEY BY LATER IN
THE DAY WEDNESDAY. THIS COLD FRONT SHOULD MOVE ACROSS THE DELMARVA
PENINSULA AND THEN OFFSHORE WEDNESDAY NIGHT. PROBABILITY OF RAIN
REMAINS HIGH...NEAR 90 TO 100 PERCENT. THE RAIN EXPECTED LOOKS TO BE
MORE CONVECTIVE IN NATURE AHEAD OF THE COLD FRONT AND POTENT STORM
SYSTEM.

HIGH TEMPERATURES WEDNESDAY WILL BE 15 TO 20 DEGREES ABOVE NORMAL AS
WE ENCOUNTER MOST LOCATIONS REACHING NEAR 60 TO THE LOWER 60S...MAINLY
EAST OF THE BLUE RIDGE MOUNTAINS. WE WILL LEAVE A CHANCE OF RAIN
SHOWERS IN THE FORECAST FOR WEDNESDAY NIGHT CONSIDERING SOME UNCERTAINTY
ON THE TIMING OF COLD FRONTAL PASSAGE. NONETHELESS...COLDER AND DRIER
AIR WILL FILTER INTO THE REGION FROM WEST TO EAST WEDNESDAY
NIGHT...ALLOWING FOR TEMPERATURES TO QUICKLY FALL THROUGH THE 50S
INTO THE 40S.

THERE IS A CHANCE FOR SOME SNOW SHOWERS IN THE HIGHER ELEVATIONS OF
THE POTOMAC HIGHLANDS THURSDAY...PERHAPS ABOVE 2500 FEET. ALTHOUGH
TEMPERATURES WILL BE SOME 10 TO 15 COOLER THAN WEDNESDAY...TEMPERATURES
WILL STILL BE SLIGHTLY ABOVE NORMAL.

DRY CONDITIONS FRIDAY WITH HIGH PRESSURE BUILDING JUST TO OUR SOUTH.
HIGH TEMPERATURES MAY STILL BE SLIGHTLY ABOVE NORMAL WITH A GOOD BIT
OF SUNSHINE.

ANOTHER COLD FRONT COULD BRING A CHANCE FOR RAIN AND SNOW SHOWERS TO
THE REGION FRIDAY NIGHT INTO SATURDAY.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS THROUGH SUNDAY...BRINGING
VFR CONDITIONS. CLOUDS WILL INCREASE SUNDAY NIGHT AND SUBVFR CONDITIONS
ARE POSSIBLE TOWARD MONDAY MORNING.

CONDITIONS WILL DETERIORATE MONDAY INTO MONDAY NIGHT WITH SUB VFR
CIGS AND VSBYS. PRECIPITATION TYPE IS A BIT UNCERTAIN ALTHOUGH
EXPECTING MOSTLY LIQUID AT KDCA AND KBWI. NORTH AND WEST COULD SEE A
WINTRY MIX OF FREEZING RAIN AND SLEET FOR PART OF MONDAY. ALL RAIN
EXPECTED MONDAY NIGHT.

IFR OR LIFR CONDITIONS ARE POSSIBLE TUESDAY AND TUESDAY NIGHT
WITH LOW CLOUDS AND PERIODS OF RAIN. WINDS LIGHT AND VARIABLE. IFR
OR LIFR CONDITIONS ARE POSSIBLE AGAIN WEDNESDAY WITH NUMEROUS
GUSTY RAIN SHOWERS AHEAD OF A COLD FRONT. WINDS SOUTHEAST TO SOUTH
5 TO 10 KNOTS WEDNESDAY...INCREASING SOUTHWEST WEDNESDAY NIGHT.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS THROUGH SUNDAY NIGHT. NO
MARINE HAZARDS ARE EXPECTED DURING THIS TIME.

WINDS COULD APPROACH SCA CRITERIA LATER MONDAY INTO EARLY TUESDAY AS
LOW PRESSURE APPROACHES FROM THE SOUTH.

NO MARINE HAZARDS TUESDAY AND TUESDAY NIGHT. SMALL CRAFT ADVISORIES
MAY BE NEEDED WEDNESDAY WITH GUSTS TO 20 KNOTS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
UPDATE...GMS
PREV DISCUSSION...BJL/KRW/KLW







000
FXUS61 KLWX 210140 AAA
AFDLWX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
840 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST INTO EARLY NEXT WEEK. LOW PRESSURE WILL
TRACK UP THE MID-ATLANTIC COAST LATE MONDAY. A STRONG COLD FRONT
WILL THEN PASS THROUGH THE AREA LATE WEDNESDAY INTO WEDNESDAY
NIGHT.

&&

.NEAR TERM /THROUGH SUNDAY/...
A COUPLE OF MINOR KINKS IN THE UPPER FLOW WILL MAKE THEIR WAY OVER
THE REGION IN THE COMING HRS. THE FIRST UPPER WAVE NOW SLIDING
OVERHEAD...BRINGING ESSENTIALLY A DENSE MID-STRATUS DECK. AT THE
SFC...MANY OB SITES W/ CALM WINDS WHICH WILL CARRY OVER INTO THE
DAYTIME HRS ON SUNDAY. THE OTHER WAVE IS RIGHT ON THE HEELS OF THE
CURRENT ONE...BOTH WILL SLOWLY DISSIPATE HEADING INTO THE
OVERNIGHT PERIOD AS THEY APPROACH THE ATLC COASTLINE.

TEMPS CONTINUE TO HOVER NEAR FREEZING ACROSS THE AREA AND WILL
SLOWLY SLIP DOWN INTO THE 20S OVERNIGHT. DEWPOINTS ALSO STAYING
THE SAME GENERAL RANGE FOR A LONG STRETCH OF TIME...GENERALLY IN
THE L-M20S WHICH WILL KEEP OUR OVERNIGHT LOWS JUST ABOVE THAT BY
THE PREDAWN HRS. SKIES WILL REMAIN CLOUDY/MOSTLY CLOUDY
OVERNIGHT...ALSO KEEPING TEMPS FROM DROPPING MUCH FURTHER W/ THE
INSULATING EFFECT. LEANED TOWARD THE BIAS-CORRECTED VERSION OF MAV
GUIDANCE FOR LOWS.

BEHIND THE UPPER WAVES...ZONAL UPPER FLOW AGAIN ENCOMPASSES THE
UPPER MIDWEST AND BUILDS IN A LARGE AREA OF HIGH PRESSURE. THIS
FEATURE WILL BUILD INTO THE REGION OVER THE COURSE OF THE DAY ON
SUNDAY...ALLOWING FOR MOSTLY CLEAR TO PARTLY CLOUDY SKIES W/ NOT
MUCH ADVECTION OF ANY KIND WE WILL STAY SEASONABLY CHILLY. WINDS
WILL STAY LIGHT AS THE CENTER OF HIGH ROLLS OVERHEAD.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
UPPER TROUGH WILL BEGIN TO AMPLIFY OVER THE EASTERN U.S ON MONDAY.
UPPER LEVEL JET/DYNAMICS SHIFT EAST TO THE COAST WHERE AN AREA OF
LOW PRESSURE IS LIKELY TO DEVELOP OVER THE CAROLINAS AND TRACK
SLOWLY NORTH INTO MONDAY NIGHT. TIMING OF PRECIPITATION IS STILL A
BIT UNCERTAIN WITHIN THE NAM/GFS/EURO SOLUTIONS WITH THE NAM BEING
THE MOST BULLISH AND QUICKEST TO ARRIVE VS THE SLOWER GFS AND EURO.
EITHER WAY...TEMPERATURES WILL BE CRUCIAL WITH COLD HIGH PRESSURE
OVER NEW ENGLAND PROVIDING CAD WEDGE OVER THE MIDDLE ATLANTIC TO
START THE EVENT.

IF PRECIPITATION BEGINS EARLIER IN THE DAY AS PER THE 12Z NAM
THERE COULD BE MORE OF AN ZR/IP THREAT EVEN OVER SOME OF THE
IMMEDIATE SUBURBS NORTH AND WEST OF DC/BWI THE FIRST PART OF
MONDAY. IT IS TYPICAL FOR GUIDANCE TO ERODE THE CAD WEDGE TOO
QUICKLY IN SITUATIONS LIKE THIS. HAVE UNDERCUT TEMPERATURES A FEW
DEGREES FROM INHERITED NUMBERS AND EXPANDED ZR/IP A BIT EAST AS
WELL. MILDER AIR WILL GRADUALLY CHANGE THE ICE TO RAIN EAST OF THE
BLUE RIDGE BUT A LONGER PERIOD OF ZR/IP MAY OCCUR WEST OF THE BLUE
RIDGE IN THE NORMALLY COLDER LOCALES. WILL CONTINUE TO HIGHLIGHT
POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK.

ENOUGH WARMER AIR SHOULD WORK IN AND CHANGE MUCH OF THE PRECIP TO
RAIN MONDAY NIGHT ALTHOUGH THERE COULD STILL BE A FEW POCKETS OF ZR
OVER THE HIGHER ELEVATIONS WITHIN THE HIGHLANDS.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
A WARM FRONT WILL INCH ITS WAY NORTHWARD FROM THE CAROLINAS TO THE
MID ATLANTIC COAST TUESDAY AND TUESDAY NIGHT. SOME STRATIFORM LIGHT
TO MODERATE RAIN WILL PRECEDE THE WARM FRONT AND OVERRUN THE ENTIRE
REGION.

THROUGH THE DAY WEDNESDAY...AS THE WARM FRONT WORKS ITS WAY NORTH OF
THE MASON-DIXON LINE...A POTENT STORM SYSTEM WILL BE PIVOTING
NORTHEASTWARD FROM THE OHIO VALLEY INTO THE EASTERN GREAT LAKES
REGION. ITS ASSOCIATED COLD FRONT WILL TRAIL SOUTHWARD AND POSSIBLY
WORK INTO THE POTOMAC HIGHLANDS AND SHENANDOAH VALLEY BY LATER IN
THE DAY WEDNESDAY. THIS COLD FRONT SHOULD MOVE ACROSS THE DELMARVA
PENINSULA AND THEN OFFSHORE WEDNESDAY NIGHT. PROBABILITY OF RAIN
REMAINS HIGH...NEAR 90 TO 100 PERCENT. THE RAIN EXPECTED LOOKS TO BE
MORE CONVECTIVE IN NATURE AHEAD OF THE COLD FRONT AND POTENT STORM
SYSTEM.

HIGH TEMPERATURES WEDNESDAY WILL BE 15 TO 20 DEGREES ABOVE NORMAL AS
WE ENCOUNTER MOST LOCATIONS REACHING NEAR 60 TO THE LOWER 60S...MAINLY
EAST OF THE BLUE RIDGE MOUNTAINS. WE WILL LEAVE A CHANCE OF RAIN
SHOWERS IN THE FORECAST FOR WEDNESDAY NIGHT CONSIDERING SOME UNCERTAINTY
ON THE TIMING OF COLD FRONTAL PASSAGE. NONETHELESS...COLDER AND DRIER
AIR WILL FILTER INTO THE REGION FROM WEST TO EAST WEDNESDAY
NIGHT...ALLOWING FOR TEMPERATURES TO QUICKLY FALL THROUGH THE 50S
INTO THE 40S.

THERE IS A CHANCE FOR SOME SNOW SHOWERS IN THE HIGHER ELEVATIONS OF
THE POTOMAC HIGHLANDS THURSDAY...PERHAPS ABOVE 2500 FEET. ALTHOUGH
TEMPERATURES WILL BE SOME 10 TO 15 COOLER THAN WEDNESDAY...TEMPERATURES
WILL STILL BE SLIGHTLY ABOVE NORMAL.

DRY CONDITIONS FRIDAY WITH HIGH PRESSURE BUILDING JUST TO OUR SOUTH.
HIGH TEMPERATURES MAY STILL BE SLIGHTLY ABOVE NORMAL WITH A GOOD BIT
OF SUNSHINE.

ANOTHER COLD FRONT COULD BRING A CHANCE FOR RAIN AND SNOW SHOWERS TO
THE REGION FRIDAY NIGHT INTO SATURDAY.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS THROUGH SUNDAY...BRINGING
VFR CONDITIONS. CLOUDS WILL INCREASE SUNDAY NIGHT AND SUBVFR CONDITIONS
ARE POSSIBLE TOWARD MONDAY MORNING.

CONDITIONS WILL DETERIORATE MONDAY INTO MONDAY NIGHT WITH SUB VFR
CIGS AND VSBYS. PRECIPITATION TYPE IS A BIT UNCERTAIN ALTHOUGH
EXPECTING MOSTLY LIQUID AT KDCA AND KBWI. NORTH AND WEST COULD SEE A
WINTRY MIX OF FREEZING RAIN AND SLEET FOR PART OF MONDAY. ALL RAIN
EXPECTED MONDAY NIGHT.

IFR OR LIFR CONDITIONS ARE POSSIBLE TUESDAY AND TUESDAY NIGHT
WITH LOW CLOUDS AND PERIODS OF RAIN. WINDS LIGHT AND VARIABLE. IFR
OR LIFR CONDITIONS ARE POSSIBLE AGAIN WEDNESDAY WITH NUMEROUS
GUSTY RAIN SHOWERS AHEAD OF A COLD FRONT. WINDS SOUTHEAST TO SOUTH
5 TO 10 KNOTS WEDNESDAY...INCREASING SOUTHWEST WEDNESDAY NIGHT.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS THROUGH SUNDAY NIGHT. NO
MARINE HAZARDS ARE EXPECTED DURING THIS TIME.

WINDS COULD APPROACH SCA CRITERIA LATER MONDAY INTO EARLY TUESDAY AS
LOW PRESSURE APPROACHES FROM THE SOUTH.

NO MARINE HAZARDS TUESDAY AND TUESDAY NIGHT. SMALL CRAFT ADVISORIES
MAY BE NEEDED WEDNESDAY WITH GUSTS TO 20 KNOTS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
UPDATE...GMS
PREV DISCUSSION...BJL/KRW/KLW







000
FXUS61 KAKQ 210005
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
705 PM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL PUSH OFF THE SOUTHEAST COAST TONIGHT...AS HIGH
PRESSURE REMAINS OVER THE LOCAL AREA THROUGH SUNDAY EVENING. ANOTHER
LOW PRESSURE AREA MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP
ALONG THE CAROLINA COAST LATE MONDAY INTO TUESDAY...AS HIGH PRESSURE
DRIFTS OFF THE NEW ENGLAND COAST INTO THE CANADIAN MARITIMES. A COLD
FRONT WILL CROSS THE WEDNESDAY NIGHT WITH HIGH PRESSURE RETURNING
BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
LATEST ANALYSIS SHOWS ~1030 MB SFC HIGH PRESSURE CENTERED OVER
EASTERN CANADA...RIDGING DOWN INTO THE MID ATLC. SFC LOW PRESSURE
SLIDING INTO THE ATLC OFF THE COAST OF NORTHERN FL. DRIER AIR
BEGINNING TO ERODE SOME OF THE CLOUD COVER OVER THE REGION
ALTHOUGH SKIES ARE STILL MOSTLY CLOUDY OVERALL THIS AFTN...WITH
TEMPERATURES MAINLY IN THE UPPER 30S TO LOWER 40S. SPOTTY LIGHT
PRECIP NOW BECOMING CONFINED TO NE NC AND SHOULD MOVE OFFSHORE
OVER THE NEXT FEW HRS. WILL MAINTAIN 20% POPS IN THE FAR SE
ZONES...OTHERWISE WILL HAVE A DRY FORECAST THIS EVENING/OVERNIGHT.
MODEL BUFKIT SOUNDINGS SHOW A FAIR AMOUNT OF LINGERING LOW LEVEL
MOISTURE OVERNIGHT SO NOT CONFIDENT THAT SKIES COMPLETELY CLEAR
OUT OVERNIGHT (WILL GO PARTLY CLOUDY). LOWS WILL RANGE FROM THE
MID 20S OVER MUCH OF THE NORTHERN 1/2 OF THE CWA AWAY FROM THE
COAST...TO THE LOWER 30S OVER SE COASTAL SECTIONS. IF SKIES
COMPLETELY CLEAR OUT MAY SEE TEMPS A FEW DEGREES COLDER THAN THIS.

HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. LIGHT WINDS OVERALL WITH A LIGHT ONSHORE
NE FLOW OVER THE SE COASTAL ZONES...SEASONABLE HIGHS IN THE LOWER-
MID 40S NE TO AROUND 50 F IN SOUTH CENTRAL VA.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
MODELS SHOW NEXT SHORTWAVE TROUGH AMPLIFYING ACRS THE NORTHERN
PLAINS SUN NIGHT/MON...AS STRONG UPPER LEVEL RIDGING HOLDS STRONG
FROM FLORIDA TO THE CARIBBEAN. MID/UPPER LEVEL FLOW PROGGED TO
TURN MORE SW AND THIS WILL HELP STEER LOW PRESSURE NE FROM THE
GULF COAST STATES INTO THE SE AND MID ATLC COASTAL WATERS MON/MON
NIGHT. POSITION OF SFC HIGH TO OUR N...SHIFTING EAST TO THE NEW
ENGLAND COAST BY 12Z/MON IS NOT FAVORABLE FOR LOCKING COLD AIR
OVER THE AKQ CWA. STILL SHOULD SEE ENOUGH COLD AIR INITIALLY OVER
THE REGION SUN NIGHT/MON MORNING DUE TO CLEAR SKIES THROUGH PART
OF THE NIGHT. THIS WILL LEAD TO THE CHC OF A FEW HRS WORTH OF
OVERRUNNING FROZEN PRECIP OVER CLIMO FAVORED PIEDMONT ZONES NW OF
RICHMOND (WITH LITTLE CHC FOR ANYTHING BUT ALL RAIN OVER THE REST
OF THE CWA). LOW LEVEL THICKNESSES (1000-850MB) ARE MARGINAL BUT
BUFKIT SOUNDINGS SHOW A NARROW LAYER OF BELOW FREEZING TEMPS AT
THE SFC FROM ABOUT 09-15Z/MON AT KCHO (AND LIKELY AT KLKU). STILL
SOME QUESTION AS TO HOW FAST PRECIP ARRIVES BUT OVERALL LOOKS LIKE
CHANCES RAMP UP SIGNIFICANTLY DURING THE 09-12Z TIMEFRAME. WILL GO
WITH A CHC FOR SLEET OVER THE PIEDMONT BETWEEN
09-12Z...TRANSITIONING TO SLEET/FREEZING RAIN FROM ABOUT
12-15Z/MON (ALTHOUGH BECOMING CONFINED TO THE FAR NW BY THIS
POINT). IN ANY EVENT...THIS LOOKS LIGHT AS BULK OF DEEPER MOISTURE
LIKELY ARRIVES AFTER A CHANGEOVER TO ALL RAIN. ALSO...NOT
ANTICIPATING TEMPS IN MID 20S...GENLY CLOSER TO 30-32 F...SO
IMPACTS ARE EXPECTED TO BE MINIMAL FOR THE MOST PART.

HIGHS MON ONLY IN THE UPPER 30S/AROUND 40 NW TO THE MID 50S FAR SE IN
CAD SETUP. MAINTAINING LIKELY TO CATEGORICAL POPS THROUGH MON
AFTN...ALTHOUGH QPF AMOUNTS ONLY AVG 0.25-0.50". LOW PRESSURE
LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING FROM
SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION
TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM THE GULF
STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE MAINTAINED.
HIGHS IN THE LOW 60S FAR SE TO THE UPPER 40S NW.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
NO PCPN IS EXPECTED DURING THE 00Z TAF PERIOD. BKN CLOUDS WERE OVER
MUCH OF THE AREA. MODEL SOUNDINGS INDICATED DRY AIR ABV 10K FT BUT
METARS HAVE BASES JUST BELOW THAT LEVEL. A THIN CLOUD DECK OF AROUND
8-10K FT IS EXPECTED TO DIMINISH TOWARD MORNING. SOME CLOUDS AT 5K
FT WERE REPORTED AT ECG. A MOSTLY CLEAR SKY IS FORECAST ON SUNDAY.
WINDS WILL BE LIGHT THROUGH THE PERIOD.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY. A COLD FRONT PASSES
THROUGH WEDNESDAY NIGHT WITH VFR CONDS AND DRY WEATHER THURSDAY.

&&

.MARINE...
QUIET/BENIGN CONDITIONS EXPECTED ACROSS ALL WATERS TONIGHT THROUGH
MOST OF SUNDAY NIGHT AS WEAK HIGH PRESSURE RIDGING RESIDES OVER THE
MID ATLANTIC REGION. WINDS WILL GENERALLY BE NORTH 5-10KT WITH
WAVES/SEAS AVERAGING 1-2FT. MEANWHILE...LOW PRESSURE CURRENTLY
STALLED OFF THE SE COAST GETS ABSORBED INTO ANOTHER LOW PRESSURE
SYSTEM TRACKING NE OUT OF THE NERN GULF OF MEXICO TO JUST OFF THE SE
COAST TONIGHT (RIDING ALONG THE BOUNDARY LEFT BY THE CURRENT SE
COAST LOW). THE NEWLY FORMED SE COAST LOW SLOWLY MOVES UP THE
CAROLINA COAST ON MON AND THE MID ATLANTIC COAST MON NIGHT...WASHING
OUT ON TUE/TUE NIGHT AS A VERY STRONG AND VIGOROUS SFC LOW DEEPENS
OVER THE OHIO VALLEY/GREAT LAKES REGIONS AND PUSHES A STRONG COLD
FRONT TWD THE AREA. WINDS TURN TO THE NE SUN NIGHT AND GRADUALLY
INCREASE TO 15-20KT FROM SOUTH TO NORTH ON MON. LOW-END SCA
CONDITIONS ARE ANTICIPATED TO DEVELOP BY MON AFTN AND PERSIST OVER
SRN WATERS THROUGH EARLY MON EVENING...AND OVER NRN WATERS THROUGH
LATE MON EVENING.

A BRIEF REPRIEVE IN SCA CONDITIONS IS EXPECTED TUE/TUE NIGHT AS THE
COASTAL LOW GETS WASHED OUT OVER THE MID ATLANTIC REGION. A WARM
FRONT LIFTS NORTH ACROSS THE WATERS ON WED AS A VERY STRONG COLD
FRONT APPROACHES THE REGION FROM THE WEST. THE SFC PRESSURE GRADIENT
TIGHTENS SIGNIFICANTLY ON WED AS A STRONG JET STREAK (90-150KT) ALSO
NOSES INTO THE REGION FROM THE SSW. SOUTH WINDS WILL INCREASE TO
SPEEDS OF 15-25KT IN THE SRN WATERS DURING THE MORNING AND IN THE
NRN WATERS BY THE AFTN WITH SCA CONDITIONS LIKELY DEVELOPING DURING
THE AFOREMENTIONED TIMEFRAMES. SEAS SHOULD RESPOND TO THE SLY WINDS
PRIOR TO SEEING THE INCREASED WIND SPEEDS WITH SEAS BUILDING FROM
2-4FT TUE NIGHT TO 4-5FT BY WED MORNING. WAVES WILL BUILD TO 3-4FT
ON CHES BAY ON WED. THE COLD FRONT IS EXPECTED TO CROSS THE WATERS
WED EVENING AND SOLID SCA CONDITIONS WILL LIKELY OCCUR AHEAD OF AND
BEHIND ITS PASSAGE. AM NOT ANTICIPATING GALE FORCE GUSTS UNLESS THEY
ARE ASSOCIATED WITH CONVECTIVE SHOWERS WED AFTN/EVENING. SEAS
CONTINUE TO BUILD TO 5-9FT WED NIGHT THROUGH THU BEFORE STARTING TO
SUBSIDE. S-SW WINDS OF 20-30KT WED NIGHT BECOME WLY ON
THU...REMAINING STRONG THROUGH THE DAY THU. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL BRING A RETURN TO BREEZY NW WINDS ACROSS THE WATERS LATE SAT
NIGHT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...JDM/LKB
LONG TERM...BMD
AVIATION...LSA
MARINE...BMD






000
FXUS61 KPBZ 202323
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
623 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL INTO MONDAY. EXPECT INCREASING
PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN AND WIND
CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
WITH 615PM UPDATE...LOWER CLOUDS REMAIN SCATTERED OUT FROM
PITTSBURGH TO LATROBE AND MORGANTOWN...BUT DO NOT EXPECT THIS TO
PERSIST THROUGH THE EVENING. MINIMAL CHANGES WERE NEEDED TO HOURLY
TEMPERATURE TRENDS. PREVIOUS DISCUSSION FOLLOWS.

WEAKER INVERSION ACROSS PORTIONS OF SOUTHERN PA HAS ALLOWED LOWER
CLOUDS TO BREAK UP SOMEWHAT...ALTHOUGH THEY ARE HANGING TOUGH SO FAR
ACROSS THE NORTHERN COUNTIES NEAR FKL/DUJ AS WELL AS IN SOUTHEAST
OHIO.  EXPECT THESE TO REFORM TONIGHT AS INVERSION SHARPENS UP AGAIN
IN VERY WEAK FLOW...THUS GOING MOSTLY CLOUDY MOST AREAS.  GOING TO HANG
ON TO SLIGHT CHANCE POPS IN THE SOUTHEAST WITH SHORTWAVE TROUGH
MOVING ACROSS AND SLIGHTLY BETTER MOISTURE PROFILE...BUT SNOW
ACCUMULATION IS NOT EXPECTED.  THIS POSSIBILITY ENDS BY 09Z. ONLY
MINOR MODIFICATION TO GENERALLY SEASONABLE TEMPERATURES.

INVERSION IS MAINTAINED SUNDAY MORNING...BUT BY AFTERNOON EXPECT
STRATUS TO MIX OUT INTO A CU FIELD AND THEN SCATTER OUT BY EVENING.
A BIT MORE SUN SHOULD ALLOW FOR AFTERNOON HIGH TEMPS AROUND 5
DEGREES WARMER THAN TODAY. CL

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
BENIGN WEATHER INITIALLY WITH HIGH PRESSURE TO OUR EAST AND IN
CONTROL.  SOUTHEAST WINDS IN RESPONSE TO SURFACE ANTICYCLONE
POSITION WILL FACILITATE DEVELOPMENT OF STRATUS OVER EASTERN
PORTIONS OF TUCKER AND GARRETT COUNTIES MONDAY INTO MONDAY NIGHT.
PCPN ONSET HAS SLOWED DOWN FROM PREVIOUS CYCLES...BUT THERE REMAINS
A VERY LOW PROBABILITY OF FREEZING RAIN AND/OR SLEET OVER
AFOREMENTIONED AREAS MONDAY.  FOR NOW...TRENDED FORECAST WITH PCPN
COMMENCING DURING THE AFTERNOON WHICH REFLECT LATEST NUMERICAL
MODELS.  WITH THIS SCENARIO...LOW LEVEL SUB-FREEZING AIR SHOULD
SCOUR OUT YIELDING AN ALL RAIN PTYPE.

RAIN SHADOW EFFECT TAKES PLACES TUESDAY WITH SOUTHEAST WINDS
WIDESPREAD OVER THE REGION. AN ISOLATED SHOWER REACHING EASTERN OHIO
AND FAR NWRN PA IS NOT OUT OF THE QUESTION...SO KEPT A SLIGHT
CHANCE.  WOULD NOT BE SURPRISED TO SEE BREAKS IN THE CLOUDS WHICH
COULD ALLOW FOR A FEW LOCATIONS TO EXCEED 60 DEGREES.  RECORD HIGHS
FOR PITTSBURGH...MORGANTOWN...AND ZANESVILLE ALL RESIDE WELL INTO
THE UPPER 60S...SO AT THIS JUNCTURE RECORD WARMTH IS NOT FORESEEN.
PRECIP ASSOCIATED WITH THE SURFACE LOW PRESSURE SYSTEM EJECTING FROM
THE GULF COAST REGION REACHES SERN AREAS OF THE FORECAST AREA THAT
EVENING.

A BLEND OF THE ONGOING FORECAST AND BIAS CORRECTED ECMWF WERE USED
FOR TEMPERATURES.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED GIVEN THE
TIME PERIOD WHICH IT AFFECTS OUR AREA IS STILL ON TRACK.  LONG RANGE
ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE CONVERGING ON
A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.  THIS WILL MAKE
FOR ALL LIQUID PRECIPITATION ON THE FRONT END.  TEMPERATURES WILL
SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY WITH 50S COMMON.
COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF MEXICO...SOUNDINGS
ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES TEMP DIFFERENTIAL
BETWEEN H8 AND H5 TO NEARLY 0C.  THIS COULD LEAD TO ISOLATED
THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE.  FOR THE TIME
BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT FOR
BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT.  DESPITE PWATS
NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT.  LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE PROJECTED
QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY.  FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST.  HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE GROUND
AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME.  ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER.  EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE.  NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS.  MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
WHILE FKL...DUJ...AND ZZV ARE EXPECTED TO REMAIN UNDER MVFR CIGS
OVERNIGHT...REMAINING TERMINALS MAY CONTINUE TO HAVE LOWER CLOUDS
SCATTER OUT LEAVING A MID DECK TEMPORARILY. BY MIDNIGHT ALL
TERMINALS ARE EXPECTED TO RETURN TO UNIFORM MVFR CIGS. CANNOT RULE
OUT SOME CIGS BELOW 2KFT BUT DID NOT HAVE CONFIDENCE TO INCLUDE
THEM. UNCERTAINTY REMAINS AS TO WHEN SKIES SHOULD SCATTER OUT ON
SUNDAY. THE SCATTERING TREND SHOULD MOVE FROM SOUTHWEST TO
NORTHEAST...BUT CURRENT FORECAST DOES NOT ELIMINATE CIG FROM
PITTSBURGH AND LOCATIONS NORTHEAST UNTIL 00Z MONDAY.


OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$









000
FXUS61 KPBZ 202323
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
623 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL BE IN CONTROL INTO MONDAY. EXPECT INCREASING
PRECIPITATION CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN AND WIND
CHRISTMAS EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
WITH 615PM UPDATE...LOWER CLOUDS REMAIN SCATTERED OUT FROM
PITTSBURGH TO LATROBE AND MORGANTOWN...BUT DO NOT EXPECT THIS TO
PERSIST THROUGH THE EVENING. MINIMAL CHANGES WERE NEEDED TO HOURLY
TEMPERATURE TRENDS. PREVIOUS DISCUSSION FOLLOWS.

WEAKER INVERSION ACROSS PORTIONS OF SOUTHERN PA HAS ALLOWED LOWER
CLOUDS TO BREAK UP SOMEWHAT...ALTHOUGH THEY ARE HANGING TOUGH SO FAR
ACROSS THE NORTHERN COUNTIES NEAR FKL/DUJ AS WELL AS IN SOUTHEAST
OHIO.  EXPECT THESE TO REFORM TONIGHT AS INVERSION SHARPENS UP AGAIN
IN VERY WEAK FLOW...THUS GOING MOSTLY CLOUDY MOST AREAS.  GOING TO HANG
ON TO SLIGHT CHANCE POPS IN THE SOUTHEAST WITH SHORTWAVE TROUGH
MOVING ACROSS AND SLIGHTLY BETTER MOISTURE PROFILE...BUT SNOW
ACCUMULATION IS NOT EXPECTED.  THIS POSSIBILITY ENDS BY 09Z. ONLY
MINOR MODIFICATION TO GENERALLY SEASONABLE TEMPERATURES.

INVERSION IS MAINTAINED SUNDAY MORNING...BUT BY AFTERNOON EXPECT
STRATUS TO MIX OUT INTO A CU FIELD AND THEN SCATTER OUT BY EVENING.
A BIT MORE SUN SHOULD ALLOW FOR AFTERNOON HIGH TEMPS AROUND 5
DEGREES WARMER THAN TODAY. CL

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
BENIGN WEATHER INITIALLY WITH HIGH PRESSURE TO OUR EAST AND IN
CONTROL.  SOUTHEAST WINDS IN RESPONSE TO SURFACE ANTICYCLONE
POSITION WILL FACILITATE DEVELOPMENT OF STRATUS OVER EASTERN
PORTIONS OF TUCKER AND GARRETT COUNTIES MONDAY INTO MONDAY NIGHT.
PCPN ONSET HAS SLOWED DOWN FROM PREVIOUS CYCLES...BUT THERE REMAINS
A VERY LOW PROBABILITY OF FREEZING RAIN AND/OR SLEET OVER
AFOREMENTIONED AREAS MONDAY.  FOR NOW...TRENDED FORECAST WITH PCPN
COMMENCING DURING THE AFTERNOON WHICH REFLECT LATEST NUMERICAL
MODELS.  WITH THIS SCENARIO...LOW LEVEL SUB-FREEZING AIR SHOULD
SCOUR OUT YIELDING AN ALL RAIN PTYPE.

RAIN SHADOW EFFECT TAKES PLACES TUESDAY WITH SOUTHEAST WINDS
WIDESPREAD OVER THE REGION. AN ISOLATED SHOWER REACHING EASTERN OHIO
AND FAR NWRN PA IS NOT OUT OF THE QUESTION...SO KEPT A SLIGHT
CHANCE.  WOULD NOT BE SURPRISED TO SEE BREAKS IN THE CLOUDS WHICH
COULD ALLOW FOR A FEW LOCATIONS TO EXCEED 60 DEGREES.  RECORD HIGHS
FOR PITTSBURGH...MORGANTOWN...AND ZANESVILLE ALL RESIDE WELL INTO
THE UPPER 60S...SO AT THIS JUNCTURE RECORD WARMTH IS NOT FORESEEN.
PRECIP ASSOCIATED WITH THE SURFACE LOW PRESSURE SYSTEM EJECTING FROM
THE GULF COAST REGION REACHES SERN AREAS OF THE FORECAST AREA THAT
EVENING.

A BLEND OF THE ONGOING FORECAST AND BIAS CORRECTED ECMWF WERE USED
FOR TEMPERATURES.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED GIVEN THE
TIME PERIOD WHICH IT AFFECTS OUR AREA IS STILL ON TRACK.  LONG RANGE
ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE CONVERGING ON
A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.  THIS WILL MAKE
FOR ALL LIQUID PRECIPITATION ON THE FRONT END.  TEMPERATURES WILL
SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY WITH 50S COMMON.
COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF MEXICO...SOUNDINGS
ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES TEMP DIFFERENTIAL
BETWEEN H8 AND H5 TO NEARLY 0C.  THIS COULD LEAD TO ISOLATED
THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE.  FOR THE TIME
BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT FOR
BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT.  DESPITE PWATS
NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT.  LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE PROJECTED
QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY.  FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST.  HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE GROUND
AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME.  ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER.  EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE.  NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS.  MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
WHILE FKL...DUJ...AND ZZV ARE EXPECTED TO REMAIN UNDER MVFR CIGS
OVERNIGHT...REMAINING TERMINALS MAY CONTINUE TO HAVE LOWER CLOUDS
SCATTER OUT LEAVING A MID DECK TEMPORARILY. BY MIDNIGHT ALL
TERMINALS ARE EXPECTED TO RETURN TO UNIFORM MVFR CIGS. CANNOT RULE
OUT SOME CIGS BELOW 2KFT BUT DID NOT HAVE CONFIDENCE TO INCLUDE
THEM. UNCERTAINTY REMAINS AS TO WHEN SKIES SHOULD SCATTER OUT ON
SUNDAY. THE SCATTERING TREND SHOULD MOVE FROM SOUTHWEST TO
NORTHEAST...BUT CURRENT FORECAST DOES NOT ELIMINATE CIG FROM
PITTSBURGH AND LOCATIONS NORTHEAST UNTIL 00Z MONDAY.


OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$








000
FXUS61 KAKQ 202202
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
502 PM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL PUSH OFF THE SOUTHEAST COAST TONIGHT...AS HIGH
PRESSURE REMAINS OVER THE LOCAL AREA THROUGH SUNDAY EVENING. ANOTHER
LOW PRESSURE AREA MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP
ALONG THE CAROLINA COAST LATE MONDAY INTO TUESDAY...AS HIGH PRESSURE
DRIFTS OFF THE NEW ENGLAND COAST INTO THE CANADIAN MARITIMES. A COLD
FRONT WILL CROSS THE WEDNESDAY NIGHT WITH HIGH PRESSURE RETURNING
BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
LATEST ANALYSIS SHOWS ~1030 MB SFC HIGH PRESSURE CENTERED OVER
EASTERN CANADA...RIDGING DOWN INTO THE MID ATLC. SFC LOW PRESSURE
SLIDING INTO THE ATLC OFF THE COAST OF NORTHERN FL. DRIER AIR
BEGINNING TO ERODE SOME OF THE CLOUD COVER OVER THE REGION
ALTHOUGH SKIES ARE STILL MOSTLY CLOUDY OVERALL THIS AFTN...WITH
TEMPERATURES MAINLY IN THE UPPER 30S TO LOWER 40S. SPOTTY LIGHT
PRECIP NOW BECOMING CONFINED TO NE NC AND SHOULD MOVE OFFSHORE
OVER THE NEXT FEW HRS. WILL MAINTAIN 20% POPS IN THE FAR SE
ZONES...OTHERWISE WILL HAVE A DRY FORECAST THIS EVENING/OVERNIGHT.
MODEL BUFKIT SOUNDINGS SHOW A FAIR AMOUNT OF LINGERING LOW LEVEL
MOISTURE OVERNIGHT SO NOT CONFIDENT THAT SKIES COMPLETELY CLEAR
OUT OVERNIGHT (WILL GO PARTLY CLOUDY). LOWS WILL RANGE FROM THE
MID 20S OVER MUCH OF THE NORTHERN 1/2 OF THE CWA AWAY FROM THE
COAST...TO THE LOWER 30S OVER SE COASTAL SECTIONS. IF SKIES
COMPLETELY CLEAR OUT MAY SEE TEMPS A FEW DEGREES COLDER THAN THIS.

HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. LIGHT WINDS OVERALL WITH A LIGHT ONSHORE
NE FLOW OVER THE SE COASTAL ZONES...SEASONABLE HIGHS IN THE LOWER-
MID 40S NE TO AROUND 50 F IN SOUTH CENTRAL VA.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
MODELS SHOW NEXT SHORTWAVE TROUGH AMPLIFYING ACRS THE NORTHERN
PLAINS SUN NIGHT/MON...AS STRONG UPPER LEVEL RIDGING HOLDS STRONG
FROM FLORIDA TO THE CARIBBEAN. MID/UPPER LEVEL FLOW PROGGED TO
TURN MORE SW AND THIS WILL HELP STEER LOW PRESSURE NE FROM THE
GULF COAST STATES INTO THE SE AND MID ATLC COASTAL WATERS MON/MON
NIGHT. POSITION OF SFC HIGH TO OUR N...SHIFTING EAST TO THE NEW
ENGLAND COAST BY 12Z/MON IS NOT FAVORABLE FOR LOCKING COLD AIR
OVER THE AKQ CWA. STILL SHOULD SEE ENOUGH COLD AIR INITIALLY OVER
THE REGION SUN NIGHT/MON MORNING DUE TO CLEAR SKIES THROUGH PART
OF THE NIGHT. THIS WILL LEAD TO THE CHC OF A FEW HRS WORTH OF
OVERRUNNING FROZEN PRECIP OVER CLIMO FAVORED PIEDMONT ZONES NW OF
RICHMOND (WITH LITTLE CHC FOR ANYTHING BUT ALL RAIN OVER THE REST
OF THE CWA). LOW LEVEL THICKNESSES (1000-850MB) ARE MARGINAL BUT
BUFKIT SOUNDINGS SHOW A NARROW LAYER OF BELOW FREEZING TEMPS AT
THE SFC FROM ABOUT 09-15Z/MON AT KCHO (AND LIKELY AT KLKU). STILL
SOME QUESTION AS TO HOW FAST PRECIP ARRIVES BUT OVERALL LOOKS LIKE
CHANCES RAMP UP SIGNIFICANTLY DURING THE 09-12Z TIMEFRAME. WILL GO
WITH A CHC FOR SLEET OVER THE PIEDMONT BETWEEN
09-12Z...TRANSITIONING TO SLEET/FREEZING RAIN FROM ABOUT
12-15Z/MON (ALTHOUGH BECOMING CONFINED TO THE FAR NW BY THIS
POINT). IN ANY EVENT...THIS LOOKS LIGHT AS BULK OF DEEPER MOISTURE
LIKELY ARRIVES AFTER A CHANGEOVER TO ALL RAIN. ALSO...NOT
ANTICIPATING TEMPS IN MID 20S...GENLY CLOSER TO 30-32 F...SO
IMPACTS ARE EXPECTED TO BE MINIMAL FOR THE MOST PART.

HIGHS MON ONLY IN THE UPPER 30S/AROUND 40 NW TO THE MID 50S FAR SE IN
CAD SETUP. MAINTAINING LIKELY TO CATEGORICAL POPS THROUGH MON
AFTN...ALTHOUGH QPF AMOUNTS ONLY AVG 0.25-0.50". LOW PRESSURE
LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING FROM
SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION
TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM THE GULF
STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE MAINTAINED.
HIGHS IN THE LOW 60S FAR SE TO THE UPPER 40S NW.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
MOSTLY VFR CONDITIONS EXPECTED ACROSS THE AREA WITH SOME -RA OR
SPRINKLES DEPICTED ON RADAR ACROSS NE NC. HIGH PRESSURE MOVES WEST
OVERNIGHT AS THE WEAK WAVE OFF THE SE US COAST CONTINUES TO PUSH
OUT TO SEA. LIGHT WINDS AND VFR CONDITIONS EXPECTED THROUGH SUN
EVENING BEFORE THE APPROACH OF THE NEXT WAVE MOVING NE FROM THE
GULF OF MEXICO AND UP THE EAST COAST.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY.

&&

.MARINE...
QUIET/BENIGN CONDITIONS EXPECTED ACROSS ALL WATERS TONIGHT THROUGH
MOST OF SUNDAY NIGHT AS WEAK HIGH PRESSURE RIDGING RESIDES OVER THE
MID ATLANTIC REGION. WINDS WILL GENERALLY BE NORTH 5-10KT WITH
WAVES/SEAS AVERAGING 1-2FT. MEANWHILE...LOW PRESSURE CURRENTLY
STALLED OFF THE SE COAST GETS ABSORBED INTO ANOTHER LOW PRESSURE
SYSTEM TRACKING NE OUT OF THE NERN GULF OF MEXICO TO JUST OFF THE SE
COAST TONIGHT (RIDING ALONG THE BOUNDARY LEFT BY THE CURRENT SE
COAST LOW). THE NEWLY FORMED SE COAST LOW SLOWLY MOVES UP THE
CAROLINA COAST ON MON AND THE MID ATLANTIC COAST MON NIGHT...WASHING
OUT ON TUE/TUE NIGHT AS A VERY STRONG AND VIGOROUS SFC LOW DEEPENS
OVER THE OHIO VALLEY/GREAT LAKES REGIONS AND PUSHES A STRONG COLD
FRONT TWD THE AREA. WINDS TURN TO THE NE SUN NIGHT AND GRADUALLY
INCREASE TO 15-20KT FROM SOUTH TO NORTH ON MON. LOW-END SCA
CONDITIONS ARE ANTICIPATED TO DEVELOP BY MON AFTN AND PERSIST OVER
SRN WATERS THROUGH EARLY MON EVENING...AND OVER NRN WATERS THROUGH
LATE MON EVENING.

A BRIEF REPRIEVE IN SCA CONDITIONS IS EXPECTED TUE/TUE NIGHT AS THE
COASTAL LOW GETS WASHED OUT OVER THE MID ATLANTIC REGION. A WARM
FRONT LIFTS NORTH ACROSS THE WATERS ON WED AS A VERY STRONG COLD
FRONT APPROACHES THE REGION FROM THE WEST. THE SFC PRESSURE GRADIENT
TIGHTENS SIGNIFICANTLY ON WED AS A STRONG JET STREAK (90-150KT) ALSO
NOSES INTO THE REGION FROM THE SSW. SOUTH WINDS WILL INCREASE TO
SPEEDS OF 15-25KT IN THE SRN WATERS DURING THE MORNING AND IN THE
NRN WATERS BY THE AFTN WITH SCA CONDITIONS LIKELY DEVELOPING DURING
THE AFOREMENTIONED TIMEFRAMES. SEAS SHOULD RESPOND TO THE SLY WINDS
PRIOR TO SEEING THE INCREASED WIND SPEEDS WITH SEAS BUILDING FROM
2-4FT TUE NIGHT TO 4-5FT BY WED MORNING. WAVES WILL BUILD TO 3-4FT
ON CHES BAY ON WED. THE COLD FRONT IS EXPECTED TO CROSS THE WATERS
WED EVENING AND SOLID SCA CONDITIONS WILL LIKELY OCCUR AHEAD OF AND
BEHIND ITS PASSAGE. AM NOT ANTICIPATING GALE FORCE GUSTS UNLESS THEY
ARE ASSOCIATED WITH CONVECTIVE SHOWERS WED AFTN/EVENING. SEAS
CONTINUE TO BUILD TO 5-9FT WED NIGHT THROUGH THU BEFORE STARTING TO
SUBSIDE. S-SW WINDS OF 20-30KT WED NIGHT BECOME WLY ON
THU...REMAINING STRONG THROUGH THE DAY THU. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL BRING A RETURN TO BREEZY NW WINDS ACROSS THE WATERS LATE SAT
NIGHT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...JDM/LKB
LONG TERM...BMD
AVIATION...MAM/DAP
MARINE...BMD








000
FXUS61 KAKQ 202202
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
502 PM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL PUSH OFF THE SOUTHEAST COAST TONIGHT...AS HIGH
PRESSURE REMAINS OVER THE LOCAL AREA THROUGH SUNDAY EVENING. ANOTHER
LOW PRESSURE AREA MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP
ALONG THE CAROLINA COAST LATE MONDAY INTO TUESDAY...AS HIGH PRESSURE
DRIFTS OFF THE NEW ENGLAND COAST INTO THE CANADIAN MARITIMES. A COLD
FRONT WILL CROSS THE WEDNESDAY NIGHT WITH HIGH PRESSURE RETURNING
BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
LATEST ANALYSIS SHOWS ~1030 MB SFC HIGH PRESSURE CENTERED OVER
EASTERN CANADA...RIDGING DOWN INTO THE MID ATLC. SFC LOW PRESSURE
SLIDING INTO THE ATLC OFF THE COAST OF NORTHERN FL. DRIER AIR
BEGINNING TO ERODE SOME OF THE CLOUD COVER OVER THE REGION
ALTHOUGH SKIES ARE STILL MOSTLY CLOUDY OVERALL THIS AFTN...WITH
TEMPERATURES MAINLY IN THE UPPER 30S TO LOWER 40S. SPOTTY LIGHT
PRECIP NOW BECOMING CONFINED TO NE NC AND SHOULD MOVE OFFSHORE
OVER THE NEXT FEW HRS. WILL MAINTAIN 20% POPS IN THE FAR SE
ZONES...OTHERWISE WILL HAVE A DRY FORECAST THIS EVENING/OVERNIGHT.
MODEL BUFKIT SOUNDINGS SHOW A FAIR AMOUNT OF LINGERING LOW LEVEL
MOISTURE OVERNIGHT SO NOT CONFIDENT THAT SKIES COMPLETELY CLEAR
OUT OVERNIGHT (WILL GO PARTLY CLOUDY). LOWS WILL RANGE FROM THE
MID 20S OVER MUCH OF THE NORTHERN 1/2 OF THE CWA AWAY FROM THE
COAST...TO THE LOWER 30S OVER SE COASTAL SECTIONS. IF SKIES
COMPLETELY CLEAR OUT MAY SEE TEMPS A FEW DEGREES COLDER THAN THIS.

HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. LIGHT WINDS OVERALL WITH A LIGHT ONSHORE
NE FLOW OVER THE SE COASTAL ZONES...SEASONABLE HIGHS IN THE LOWER-
MID 40S NE TO AROUND 50 F IN SOUTH CENTRAL VA.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
MODELS SHOW NEXT SHORTWAVE TROUGH AMPLIFYING ACRS THE NORTHERN
PLAINS SUN NIGHT/MON...AS STRONG UPPER LEVEL RIDGING HOLDS STRONG
FROM FLORIDA TO THE CARIBBEAN. MID/UPPER LEVEL FLOW PROGGED TO
TURN MORE SW AND THIS WILL HELP STEER LOW PRESSURE NE FROM THE
GULF COAST STATES INTO THE SE AND MID ATLC COASTAL WATERS MON/MON
NIGHT. POSITION OF SFC HIGH TO OUR N...SHIFTING EAST TO THE NEW
ENGLAND COAST BY 12Z/MON IS NOT FAVORABLE FOR LOCKING COLD AIR
OVER THE AKQ CWA. STILL SHOULD SEE ENOUGH COLD AIR INITIALLY OVER
THE REGION SUN NIGHT/MON MORNING DUE TO CLEAR SKIES THROUGH PART
OF THE NIGHT. THIS WILL LEAD TO THE CHC OF A FEW HRS WORTH OF
OVERRUNNING FROZEN PRECIP OVER CLIMO FAVORED PIEDMONT ZONES NW OF
RICHMOND (WITH LITTLE CHC FOR ANYTHING BUT ALL RAIN OVER THE REST
OF THE CWA). LOW LEVEL THICKNESSES (1000-850MB) ARE MARGINAL BUT
BUFKIT SOUNDINGS SHOW A NARROW LAYER OF BELOW FREEZING TEMPS AT
THE SFC FROM ABOUT 09-15Z/MON AT KCHO (AND LIKELY AT KLKU). STILL
SOME QUESTION AS TO HOW FAST PRECIP ARRIVES BUT OVERALL LOOKS LIKE
CHANCES RAMP UP SIGNIFICANTLY DURING THE 09-12Z TIMEFRAME. WILL GO
WITH A CHC FOR SLEET OVER THE PIEDMONT BETWEEN
09-12Z...TRANSITIONING TO SLEET/FREEZING RAIN FROM ABOUT
12-15Z/MON (ALTHOUGH BECOMING CONFINED TO THE FAR NW BY THIS
POINT). IN ANY EVENT...THIS LOOKS LIGHT AS BULK OF DEEPER MOISTURE
LIKELY ARRIVES AFTER A CHANGEOVER TO ALL RAIN. ALSO...NOT
ANTICIPATING TEMPS IN MID 20S...GENLY CLOSER TO 30-32 F...SO
IMPACTS ARE EXPECTED TO BE MINIMAL FOR THE MOST PART.

HIGHS MON ONLY IN THE UPPER 30S/AROUND 40 NW TO THE MID 50S FAR SE IN
CAD SETUP. MAINTAINING LIKELY TO CATEGORICAL POPS THROUGH MON
AFTN...ALTHOUGH QPF AMOUNTS ONLY AVG 0.25-0.50". LOW PRESSURE
LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING FROM
SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION
TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM THE GULF
STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE MAINTAINED.
HIGHS IN THE LOW 60S FAR SE TO THE UPPER 40S NW.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A COASTAL LOW JUST OFF THE MID ATLANTIC COAST CONTINUE TO WASH OUT
TUE NIGHT AS A WARM FRONT STARTS TO LIFT NORTH THROUGH THE REGION.
MEANWHILE...A VERY STRONG AND VIGOROUS SFC LOW DEEPENS OVER THE
OH/TN VALLEYS AND PUSHES A STRONG COLD FRONT TWD THE AREA. INITIAL
PUSH OF STRATIFORM PRECIPITATION ASSOCIATED WITH THE WARM FRONT TUE
NIGHT WILL LIKELY GIVE WAY TO MORE SHOWERY PRECIPITATION AS THE MID
ATLANTIC REGION BECOMES WARM-SECTORED AHEAD OF THE APPROACHING COLD
FRONT. THE SFC PRESSURE GRADIENT TIGHTENS SIGNIFICANTLY ON WED AS
THE PARENT LOW DEEPENS OVER THE GREAT LAKES AND A STRONG JET STREAK
(90-150 KT) NOSES INTO THE REGION FROM THE SSW. HIGHS SHOULD RANGE
FROM 60-65 NW AND MD/VA LOWER EASTERN SHORE TO 65-69 FROM ROUGHLY
RICHMOND TO SE VA/NE NC. IN ADDITION TO DEWPOINTS APPROACHING 60
DEGREES ACROSS THE SERN HALF OF THE CWA...A THETA-E RIDGE IS
EXPECTED TO SURGE NWD ALONG THE SE WED MORNING INTO THE SRN MID
ATLANTIC COAST BY WED AFTN/EVENING. THE COMBINATION OF THESE
FEATURES/CONVECTIVE PARAMETERS MEANS THAT A SLIGHT CHANCE FOR
THUNDERSTORMS HAS BEEN ADDED TO THE FORECAST ACROSS SE VA AND NE NC
DURING THE AFTN/EARLY EVENING HOURS. THE FRONT EXITS THE REGION LATE
WED NIGHT AND PRECIP WILL TAPER OFF FROM WEST TO EAST...COMING TO AN
END EARLY THU MORNING.

THE UPPER TROUGH ASSOCIATED WITH THE GREAT LAKES SFC LOW SWINGS
THROUGH THE REGION LATE WED NIGHT THROUGH THU AFTN. UPPER LEVEL
INSTABILITY AND ABUNDANT SFC MOISTURE FROM RECENT PRECIPITATION
SHOULD KEEP SCT-BKN CUMULUS OVER THE AREA THROUGH THE DAY ON THU.
CAA OCCURRING BEHIND THE COLD FRONT AND A CONTINUED TIGHT SFC
PRESSURE GRADIENT WILL RESULT IN GUSTY WSW WINDS OF 20-25MPH WITH
GUSTS AROUND 35MPH...AND SHOULD BE FAIRLY UNIFORM ACROSS THE REGION.
THE GUSTY WINDS SHOULD DECOUPLE BY THU EVENING. OVERALL CONDITIONS
FRI THROUGH THE WEEKEND SHOULD BE DRY. A LEE TROUGH FORMS ACROSS THE
AREA ON FRI AND A WEAK CAD WEDGE DEVELOPS. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL USHER MUCH COLDER 850MB TEMPS OVER THE AREA (-5 TO -15C). CAA
AND A RE-TIGHTENING OF THE SFC PRESSURE GRADIENT WILL BRING A RETURN
TO BREEZY SW WINDS ON SAT AND BREEZY NW WINDS ON SUN BEHIND THE NEXT
COLD FRONTAL PASSAGE.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
MOSTLY VFR CONDITIONS EXPECTED ACROSS THE AREA WITH SOME -RA OR
SPRINKLES DEPICTED ON RADAR ACROSS NE NC. HIGH PRESSURE MOVES WEST
OVERNIGHT AS THE WEAK WAVE OFF THE SE US COAST CONTINUES TO PUSH
OUT TO SEA. LIGHT WINDS AND VFR CONDITIONS EXPECTED THROUGH SUN
EVENING BEFORE THE APPROACH OF THE NEXT WAVE MOVING NE FROM THE
GULF OF MEXICO AND UP THE EAST COAST.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY.

&&

.MARINE...
QUIET/BENIGN CONDITIONS EXPECTED ACROSS ALL WATERS TONIGHT THROUGH
MOST OF SUNDAY NIGHT AS WEAK HIGH PRESSURE RIDGING RESIDES OVER THE
MID ATLANTIC REGION. WINDS WILL GENERALLY BE NORTH 5-10KT WITH
WAVES/SEAS AVERAGING 1-2FT. MEANWHILE...LOW PRESSURE CURRENTLY
STALLED OFF THE SE COAST GETS ABSORBED INTO ANOTHER LOW PRESSURE
SYSTEM TRACKING NE OUT OF THE NERN GULF OF MEXICO TO JUST OFF THE SE
COAST TONIGHT (RIDING ALONG THE BOUNDARY LEFT BY THE CURRENT SE
COAST LOW). THE NEWLY FORMED SE COAST LOW SLOWLY MOVES UP THE
CAROLINA COAST ON MON AND THE MID ATLANTIC COAST MON NIGHT...WASHING
OUT ON TUE/TUE NIGHT AS A VERY STRONG AND VIGOROUS SFC LOW DEEPENS
OVER THE OHIO VALLEY/GREAT LAKES REGIONS AND PUSHES A STRONG COLD
FRONT TWD THE AREA. WINDS TURN TO THE NE SUN NIGHT AND GRADUALLY
INCREASE TO 15-20KT FROM SOUTH TO NORTH ON MON. LOW-END SCA
CONDITIONS ARE ANTICIPATED TO DEVELOP BY MON AFTN AND PERSIST OVER
SRN WATERS THROUGH EARLY MON EVENING...AND OVER NRN WATERS THROUGH
LATE MON EVENING.

A BRIEF REPRIEVE IN SCA CONDITIONS IS EXPECTED TUE/TUE NIGHT AS THE
COASTAL LOW GETS WASHED OUT OVER THE MID ATLANTIC REGION. A WARM
FRONT LIFTS NORTH ACROSS THE WATERS ON WED AS A VERY STRONG COLD
FRONT APPROACHES THE REGION FROM THE WEST. THE SFC PRESSURE GRADIENT
TIGHTENS SIGNIFICANTLY ON WED AS A STRONG JET STREAK (90-150KT) ALSO
NOSES INTO THE REGION FROM THE SSW. SOUTH WINDS WILL INCREASE TO
SPEEDS OF 15-25KT IN THE SRN WATERS DURING THE MORNING AND IN THE
NRN WATERS BY THE AFTN WITH SCA CONDITIONS LIKELY DEVELOPING DURING
THE AFOREMENTIONED TIMEFRAMES. SEAS SHOULD RESPOND TO THE SLY WINDS
PRIOR TO SEEING THE INCREASED WIND SPEEDS WITH SEAS BUILDING FROM
2-4FT TUE NIGHT TO 4-5FT BY WED MORNING. WAVES WILL BUILD TO 3-4FT
ON CHES BAY ON WED. THE COLD FRONT IS EXPECTED TO CROSS THE WATERS
WED EVENING AND SOLID SCA CONDITIONS WILL LIKELY OCCUR AHEAD OF AND
BEHIND ITS PASSAGE. AM NOT ANTICIPATING GALE FORCE GUSTS UNLESS THEY
ARE ASSOCIATED WITH CONVECTIVE SHOWERS WED AFTN/EVENING. SEAS
CONTINUE TO BUILD TO 5-9FT WED NIGHT THROUGH THU BEFORE STARTING TO
SUBSIDE. S-SW WINDS OF 20-30KT WED NIGHT BECOME WLY ON
THU...REMAINING STRONG THROUGH THE DAY THU. THE PRESSURE GRADIENT
RELAXES BRIEFLY FRI/FRI NIGHT AS HIGH PRESSURE BUILDING OVER THE SE
STATES EXTENDS UP INTO THE MID ATLANTIC REGION. MEANWHILE...A BROAD
UPPER TROUGH PUSHES A DRY COLD FRONT ACROSS THE REGION ON SAT WHICH
WILL BRING A RETURN TO BREEZY NW WINDS ACROSS THE WATERS LATE SAT
NIGHT.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...JDM/LKB
LONG TERM...BMD
AVIATION...MAM/DAP
MARINE...BMD









000
FXUS61 KPHI 202125
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
425 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY BUILD SOUTHWESTWARD INTO THE
REGION FROM ATLANTIC CANADA THROUGH MONDAY. LOW PRESSURE
WILL ORGANIZE OFF THE CAROLINAS MONDAY NIGHT AND MOVE
NORTHEASTWARD OFFSHORE ON TUESDAY. MEANWHILE...ANOTHER
AREA OF LOW PRESSURE WILL DEVELOP OVER THE OHIO VALLEY
AND MOVE NORTHWARD INTO QUEBEC...LEADING TO A STRONG
COLD FRONTAL PASSAGE ON THURSDAY NIGHT. HIGH PRESSURE
WILL BUILD IN ON FRIDAY AND A WEAKER COLD FRONT MAY
APPROACH THE REGION NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK HIGH PRESSURE WILL REMAIN ACROSS THE AREA TONIGHT. THERE IS
PLENTY OF MOISTURE TRAPPED BELOW THE INVERSION WHICH IS AROUND 4K-5K
FT ALOFT. THE CLOUDS ARE BREAKING UP SOMEWHAT JUST TO THE WEST AS OF
MID-AFTERNOON...SO SOME BREAKS CAN BE EXPECTED THIS EVENING...MOSTLY
ACROSS THE DELMARVA AND SRN NJ. ANOTHER SEASONABLY COLD NIGHT
EXPECTED WITH LOWS IN THE LOW 20S NORTH AND MID OR UPPER 20S SOUTH.
WINDS WILL BE LIGHT FROM THE NORTH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
AFTER A WEAK SHORTWAVE CROSSES THE AREA SUN MORNING...UPPER RIDGING
WILL TAKE PLACE. THIS WILL HOPEFULLY ALLOW MORE SUNSHINE ACROSS THE
AREA. WE HAVE WRITTEN A PARTLY TO MOSTLY SUNNY FCST FOR NOW. WE HELD
ONTO SOME EXTRA CLOUD COVER ACROSS THE SRN POCONOS HOWEVER. HIGH
TEMPERATURES SUNDAY WILL RISE INTO THE LOW 40S ACROSS SRN NJ AND THE
DELMARVA...WHILE READINGS HOLD IN THE MID/UPPER 30S ACROSS THE
NORTH/WEST AREAS. WINDS WILL REMAIN LIGHT...MOSTLY FROM THE NORTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...

* FREEZING RAIN POSSIBLE MONDAY NIGHT OVER THE NORTHWEST.
* INCREASING POTENTIAL FOR HEAVY RAIN CHRISTMAS EVE WITH
  TEMPERATURES WELL ABOVE NORMAL.
* BRISK WESTERLY WIND CHRISTMAS DAY W/FLURRIES POSSIBLE.

OVERVIEW...

VIGOROUS MID-LEVEL DISTURBANCE AND ACCOMPANYING 160 KNOT UPPER-LEVEL
JET MAX COMING ASHORE OVER THE PACIFIC NORTHWEST LATE THIS WEEKEND
WILL LEAD TO A DEEP TROUGH OVER THE MISSISSIPPI VALLEY BY MID-WEEK.
INITIAL PIECE OF ENERGY AHEAD OF THIS TROUGH IS EJECTED NORTHEAST
AND WILL LEAD TO THE DEVELOPMENT OF AN AREA OF LOW-PRESSURE OFF THE
CAROLINAS ON MONDAY. THIS WEAK FEATURE SHOULD TRACK OFFSHORE WELL
SOUTHEAST OF THE REGION ON TUESDAY PER TODAYS 12Z UKMET AND GFS...
FEEL THE NAM AND ECMWF ARE TOO FAR NORTH, SLOW, AND DEEP W/THIS
FEATURE...THUS THEY ALSO CRANK OUT TOO MUCH QPF. NEVERTHELESS...
QPF COMBINED WITH MARGINAL TEMPERATURE PROFILES OVER THE NORTHWEST
COULD SUPPORT SOME LIGHT FREEZING RAIN MONDAY NIGHT. MID-LEVEL FLOW
THEN BECOMES INCREASINGLY MERIDIONAL...PUMPING ANOMALOUSLY WARM
AND MOIST AIR UP THE EAST COAST...SETTING THE STAGE FOR HEAVY RAIN
ON CHRISTMAS EVE DAY. THE TROUGH LOOKS TO BECOME NEGATIVELY TILTED
AS IT CROSSES THE REGION...LEADING TO A STRONG FRONTAL PASSAGE LATE
WEDNESDAY INTO EARLY THURSDAY...WITH SOME FLURRIES POSSIBLE ON THE
BACK-SIDE OF THE STORM SYSTEM.

DETAILS...

MONDAY...
MID-LEVEL RIDGE CRESTS OVER THE REGION EARLY IN THE DAY...W/SURFACE
HIGH ANCHORED ALONG THE EAST COAST IN A COLD-AIR DAMMING SIGNATURE.
PRECIPITATION WILL BE LARGELY DRIVEN BY INSENTROPIC ASCENT OVER THE
COLDER LOW-LEVEL AIRMASS AND WILL BEGIN LATE IN THE DAY AS MOISTURE
STREAMS IN ALOFT AND LOW-LEVELS GRADUALLY SATURATE. THERE MAY BE A
PERIOD OF LIGHT FREEZING RAIN OVER THE NORTHWEST AS A COLD AIR
IS REINFORCED W/NORTHERLY SURFACE WINDS AND PRECIP LEADS TO
EVAPORATIONAL COOLING.

TUESDAY...
ANY LIGHT FREEZING RAIN SHOULD END EARLY IN THE MORNING WITH STRONG
WARM AIR ADVECTION ALOFT. ALTHOUGH THE BEST FORCING REMAINS WELL TO
THE WEST...BROAD ISENTROPIC ASCENT AND INCREASING MOISTURE SHOULD
LEAD TO SCATTERED RAIN SHOWERS THRU THE DAY. QPF SHOULD BE GENERALLY
LIGHT.

WEDNESDAY...
A VIGOROUS TROUGH APPROACHES FROM THE WEST W/STILL SOME SPREAD NOTED
FROM THE MEAN IN BOTH THE ECENS AND GEFS 500 HPA HEIGHT FIELDS...
INDICATING SOME DISAGREEMENT WITH REGARD TO WHAT DEGREE IT GOES
NEGATIVELY TILTED. NEVERTHELESS...A VERY DYNAMIC SYSTEM WITH SEVERAL
INGREDIENTS COMING TOGETHER FOR UP TO 1-2 INCHES OF QPF...ESPECIALLY
OVER THE HIGHER TERRAIN. NOTING A STRONG MID-LEVEL VORT MAX AND THE
LEFT-FRONT QUADRANT OF A 160 KNOT UPPER-LEVEL JET TRAVERSING THE
APPALACHIANS. ALSO NOTING STRONG WARM AIR ADVECTION AND ANOMALOUSLY
HIGH /2-3 STANDARD DEVIATION/ PRECIPITABLE WATER VALUES STREAMING
UP THE EASTERN SEABOARD. THUS THERE IS PLENTY OF MOISTURE AND
ASCENT FOR HEAVY RAINFALL...W/THE MODELS KEYING IN ON WEDNESDAY
AFTERNOON AND WEDNESDAY NIGHT FOR THE BULK OF THE PRECIP...AND
THIS WILL NEED TO BE MONITORED FOR FLOODING POTENTIAL PARTICULARLY
DUE TO THE HOLIDAY TRAVEL CHRISTMAS EVE. LATER SHIFTS WILL ALSO
NEED TO FURTHER EVALUATE THE POTENTIAL FOR GUSTY SURFACE WINDS
AND CONVECTION.

THURSDAY AND FRIDAY...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS TO
BUILD IN. TEMPERATURES WILL REMAIN ABOVE SEASONABLE LEVELS AND THERE
COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW ON THURSDAY...
PARTICULARLY NORTHWEST.

SATURDAY...ANOTHER COLD FRONT MAY APPROACH THE REGION...BUT IT/S TOO
EARLY TO SPECULATE...ESPECIALLY GIVEN THE UNCERTAINTY THAT THE STORM
SYSTEM MOVING THROUGH THE NORTHEAST CONUS MID-WEEK COULD ADD TO THE
FORECAST.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THERE HAS BEEN PLENTY OF LOW LEVEL MOISTURE TRAPPED BELOW THE
INVERSION AGAIN TODAY. CIGS HAVE BEEN MOSTLY 025-035 ACROSS THE
AREA. WINDS HAVE BEEN LIGHT...MOSTLY IN THE NORTH QUADRANT.
CONDITIONS WILL NOT CHANGE MUCH THIS AFTERNOON...BUT SATELLITE PICS
DO SHOW SOME BREAKS IN THE DECK ACROSS NRN MD AND THE SUSQ VALLEY
WHICH MAY ARRIVE ACROSS THE DEL VALLEY AROUND EVENING. MUCH OF THE
GUIDANCE INDICATES MORE CLEARING (OF THE LOW CLOUDS) OVERNIGHT WITH
SOME CI/CS ABOVE. WE HAVE GONE ALONG WITH THAT FOR THE TAFS...BUT A
FEW SITES HOLDING ON TO LOW CLOUDS LONGER...WOULDN`T SURPRISE ME.
SUNDAY...VFR EXPECTED WITH JUST SOME FEW-SCT LOW CLOUDS AND MOSTLY N
OR NE WINDS.

OUTLOOK...

SUNDAY NIGHT AND MONDAY MORNING...VFR.

MONDAY AFTERNOON...POTENTIAL FOR MVFR CIGS AS MARINE LAYER BECOMES
ESTABLISHED AND STRATUS ADVECTS INLAND.

MONDAY NIGHT THROUGH TUESDAY NIGHT...THE COMBINATION OF
STRENGTHENING ONSHORE FLOW AND IN-SITU CAD FROM LIGHT RAIN
OVERSPREADING THE TERMINALS COULD YIELD AN EXTENDED PERIOD OF
MVFR/IFR CONDITIONS (CIGS WOULD BE THE MORE LIKELY CONTRIBUTOR TO
IFR THAN VSBYS) MONDAY NIGHT INTO TUESDAY.

WEDNESDAY...WINDS VEER MORE OUT OF THE SOUTH AS A WARM FRONT SLOWLY
LIFTS NORTHWARD. RAIN IS EXPECTED TO BE THE MOST WIDESPREAD AND
HEAVIEST DURING THIS PART OF THE FORECAST PERIOD. PREDOMINATELY MVFR
AND IFR CONDITIONS. SOUTHERLY WINDS WILL BECOME BREEZY FOLLOWING
WARM FROPA.

WEDNESDAY NIGHT...COLD FRONT IS FORECAST TO MOVE THRU SOMETIME AT
NIGHT. LOW CLOUDS AND RAIN WILL END FROM WEST TO EAST IN WAKE OF
FROPA.

THURSDAY...WESTERLY WINDS COULD BECOME STRONG BEHIND THE FRONT
THURSDAY WITH BUFKIT FORECAST SOUNDINGS FROM THE 12Z GFS SHOWING THE
POTENTIAL FOR 30-40 KT GUSTS.

&&

.MARINE...
WEAK HIGH PRESSURE WILL REMAIN ACROSS THE WATERS TONIGHT AND SUNDAY.
WINDS AND SEAS WILL REMAIN BELOW SCA FLAG CRITERIA. WINDS WILL
MOSTLY BE NORTHERLY THROUGH THE PERIOD.

OUTLOOK...
SUNDAY NIGHT THROUGH MONDAY NIGHT...WINDS AND SEAS BELOW SCA
CRITERIA.

TUESDAY AND TUESDAY NIGHT...ONSHORE FLOW STRENGTHENS ON TUESDAY.
WINDS 15-20 KT FORECAST ON TUESDAY. SEAS ARE FORECAST TO BUILD TO
5-6 FEET TUESDAY AND TUESDAY NIGHT, WARRANTING THE NEED FOR A SCA.

WEDNESDAY AND WEDNESDAY NIGHT...SOUTHERLY WINDS STRENGTHEN AFTER
WARM FROPA. DESPITE WINDS OF 40-50 KT FORECAST 1000 FT ABOVE THE
SURFACE, THERMAL PROFILES NOT FAVORABLE FOR MIXING WITH THE SETUP OF
WARM AIR MOVING ATOP THE COOLER WATERS. EXPECTING MORE OF A HIGH END
SCA WITH 25-30 KT WINDS. WINDS FORECAST TO BECOME WESTERLY LATE
WEDNESDAY NIGHT BEHIND A COLD FRONT BUT THE CORE OF THE COLD AIR
WILL STILL REMAIN UPSTREAM OF THE WATERS. SEAS FORECAST TO INCREASE
TO 6-8 FEET.

THURSDAY...GUSTY WESTERLY WINDS EXPECTED. GALES CERTAINLY A
POSSIBILITY.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...O`HARA
SHORT TERM...O`HARA
LONG TERM...FRANCK
AVIATION...KLEIN/O`HARA
MARINE...KLEIN/O`HARA






000
FXUS61 KPHI 202125
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
425 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL SLOWLY BUILD SOUTHWESTWARD INTO THE
REGION FROM ATLANTIC CANADA THROUGH MONDAY. LOW PRESSURE
WILL ORGANIZE OFF THE CAROLINAS MONDAY NIGHT AND MOVE
NORTHEASTWARD OFFSHORE ON TUESDAY. MEANWHILE...ANOTHER
AREA OF LOW PRESSURE WILL DEVELOP OVER THE OHIO VALLEY
AND MOVE NORTHWARD INTO QUEBEC...LEADING TO A STRONG
COLD FRONTAL PASSAGE ON THURSDAY NIGHT. HIGH PRESSURE
WILL BUILD IN ON FRIDAY AND A WEAKER COLD FRONT MAY
APPROACH THE REGION NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK HIGH PRESSURE WILL REMAIN ACROSS THE AREA TONIGHT. THERE IS
PLENTY OF MOISTURE TRAPPED BELOW THE INVERSION WHICH IS AROUND 4K-5K
FT ALOFT. THE CLOUDS ARE BREAKING UP SOMEWHAT JUST TO THE WEST AS OF
MID-AFTERNOON...SO SOME BREAKS CAN BE EXPECTED THIS EVENING...MOSTLY
ACROSS THE DELMARVA AND SRN NJ. ANOTHER SEASONABLY COLD NIGHT
EXPECTED WITH LOWS IN THE LOW 20S NORTH AND MID OR UPPER 20S SOUTH.
WINDS WILL BE LIGHT FROM THE NORTH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
AFTER A WEAK SHORTWAVE CROSSES THE AREA SUN MORNING...UPPER RIDGING
WILL TAKE PLACE. THIS WILL HOPEFULLY ALLOW MORE SUNSHINE ACROSS THE
AREA. WE HAVE WRITTEN A PARTLY TO MOSTLY SUNNY FCST FOR NOW. WE HELD
ONTO SOME EXTRA CLOUD COVER ACROSS THE SRN POCONOS HOWEVER. HIGH
TEMPERATURES SUNDAY WILL RISE INTO THE LOW 40S ACROSS SRN NJ AND THE
DELMARVA...WHILE READINGS HOLD IN THE MID/UPPER 30S ACROSS THE
NORTH/WEST AREAS. WINDS WILL REMAIN LIGHT...MOSTLY FROM THE NORTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...

* FREEZING RAIN POSSIBLE MONDAY NIGHT OVER THE NORTHWEST.
* INCREASING POTENTIAL FOR HEAVY RAIN CHRISTMAS EVE WITH
  TEMPERATURES WELL ABOVE NORMAL.
* BRISK WESTERLY WIND CHRISTMAS DAY W/FLURRIES POSSIBLE.

OVERVIEW...

VIGOROUS MID-LEVEL DISTURBANCE AND ACCOMPANYING 160 KNOT UPPER-LEVEL
JET MAX COMING ASHORE OVER THE PACIFIC NORTHWEST LATE THIS WEEKEND
WILL LEAD TO A DEEP TROUGH OVER THE MISSISSIPPI VALLEY BY MID-WEEK.
INITIAL PIECE OF ENERGY AHEAD OF THIS TROUGH IS EJECTED NORTHEAST
AND WILL LEAD TO THE DEVELOPMENT OF AN AREA OF LOW-PRESSURE OFF THE
CAROLINAS ON MONDAY. THIS WEAK FEATURE SHOULD TRACK OFFSHORE WELL
SOUTHEAST OF THE REGION ON TUESDAY PER TODAYS 12Z UKMET AND GFS...
FEEL THE NAM AND ECMWF ARE TOO FAR NORTH, SLOW, AND DEEP W/THIS
FEATURE...THUS THEY ALSO CRANK OUT TOO MUCH QPF. NEVERTHELESS...
QPF COMBINED WITH MARGINAL TEMPERATURE PROFILES OVER THE NORTHWEST
COULD SUPPORT SOME LIGHT FREEZING RAIN MONDAY NIGHT. MID-LEVEL FLOW
THEN BECOMES INCREASINGLY MERIDIONAL...PUMPING ANOMALOUSLY WARM
AND MOIST AIR UP THE EAST COAST...SETTING THE STAGE FOR HEAVY RAIN
ON CHRISTMAS EVE DAY. THE TROUGH LOOKS TO BECOME NEGATIVELY TILTED
AS IT CROSSES THE REGION...LEADING TO A STRONG FRONTAL PASSAGE LATE
WEDNESDAY INTO EARLY THURSDAY...WITH SOME FLURRIES POSSIBLE ON THE
BACK-SIDE OF THE STORM SYSTEM.

DETAILS...

MONDAY...
MID-LEVEL RIDGE CRESTS OVER THE REGION EARLY IN THE DAY...W/SURFACE
HIGH ANCHORED ALONG THE EAST COAST IN A COLD-AIR DAMMING SIGNATURE.
PRECIPITATION WILL BE LARGELY DRIVEN BY INSENTROPIC ASCENT OVER THE
COLDER LOW-LEVEL AIRMASS AND WILL BEGIN LATE IN THE DAY AS MOISTURE
STREAMS IN ALOFT AND LOW-LEVELS GRADUALLY SATURATE. THERE MAY BE A
PERIOD OF LIGHT FREEZING RAIN OVER THE NORTHWEST AS A COLD AIR
IS REINFORCED W/NORTHERLY SURFACE WINDS AND PRECIP LEADS TO
EVAPORATIONAL COOLING.

TUESDAY...
ANY LIGHT FREEZING RAIN SHOULD END EARLY IN THE MORNING WITH STRONG
WARM AIR ADVECTION ALOFT. ALTHOUGH THE BEST FORCING REMAINS WELL TO
THE WEST...BROAD ISENTROPIC ASCENT AND INCREASING MOISTURE SHOULD
LEAD TO SCATTERED RAIN SHOWERS THRU THE DAY. QPF SHOULD BE GENERALLY
LIGHT.

WEDNESDAY...
A VIGOROUS TROUGH APPROACHES FROM THE WEST W/STILL SOME SPREAD NOTED
FROM THE MEAN IN BOTH THE ECENS AND GEFS 500 HPA HEIGHT FIELDS...
INDICATING SOME DISAGREEMENT WITH REGARD TO WHAT DEGREE IT GOES
NEGATIVELY TILTED. NEVERTHELESS...A VERY DYNAMIC SYSTEM WITH SEVERAL
INGREDIENTS COMING TOGETHER FOR UP TO 1-2 INCHES OF QPF...ESPECIALLY
OVER THE HIGHER TERRAIN. NOTING A STRONG MID-LEVEL VORT MAX AND THE
LEFT-FRONT QUADRANT OF A 160 KNOT UPPER-LEVEL JET TRAVERSING THE
APPALACHIANS. ALSO NOTING STRONG WARM AIR ADVECTION AND ANOMALOUSLY
HIGH /2-3 STANDARD DEVIATION/ PRECIPITABLE WATER VALUES STREAMING
UP THE EASTERN SEABOARD. THUS THERE IS PLENTY OF MOISTURE AND
ASCENT FOR HEAVY RAINFALL...W/THE MODELS KEYING IN ON WEDNESDAY
AFTERNOON AND WEDNESDAY NIGHT FOR THE BULK OF THE PRECIP...AND
THIS WILL NEED TO BE MONITORED FOR FLOODING POTENTIAL PARTICULARLY
DUE TO THE HOLIDAY TRAVEL CHRISTMAS EVE. LATER SHIFTS WILL ALSO
NEED TO FURTHER EVALUATE THE POTENTIAL FOR GUSTY SURFACE WINDS
AND CONVECTION.

THURSDAY AND FRIDAY...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS TO
BUILD IN. TEMPERATURES WILL REMAIN ABOVE SEASONABLE LEVELS AND THERE
COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW ON THURSDAY...
PARTICULARLY NORTHWEST.

SATURDAY...ANOTHER COLD FRONT MAY APPROACH THE REGION...BUT IT/S TOO
EARLY TO SPECULATE...ESPECIALLY GIVEN THE UNCERTAINTY THAT THE STORM
SYSTEM MOVING THROUGH THE NORTHEAST CONUS MID-WEEK COULD ADD TO THE
FORECAST.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THERE HAS BEEN PLENTY OF LOW LEVEL MOISTURE TRAPPED BELOW THE
INVERSION AGAIN TODAY. CIGS HAVE BEEN MOSTLY 025-035 ACROSS THE
AREA. WINDS HAVE BEEN LIGHT...MOSTLY IN THE NORTH QUADRANT.
CONDITIONS WILL NOT CHANGE MUCH THIS AFTERNOON...BUT SATELLITE PICS
DO SHOW SOME BREAKS IN THE DECK ACROSS NRN MD AND THE SUSQ VALLEY
WHICH MAY ARRIVE ACROSS THE DEL VALLEY AROUND EVENING. MUCH OF THE
GUIDANCE INDICATES MORE CLEARING (OF THE LOW CLOUDS) OVERNIGHT WITH
SOME CI/CS ABOVE. WE HAVE GONE ALONG WITH THAT FOR THE TAFS...BUT A
FEW SITES HOLDING ON TO LOW CLOUDS LONGER...WOULDN`T SURPRISE ME.
SUNDAY...VFR EXPECTED WITH JUST SOME FEW-SCT LOW CLOUDS AND MOSTLY N
OR NE WINDS.

OUTLOOK...

SUNDAY NIGHT AND MONDAY MORNING...VFR.

MONDAY AFTERNOON...POTENTIAL FOR MVFR CIGS AS MARINE LAYER BECOMES
ESTABLISHED AND STRATUS ADVECTS INLAND.

MONDAY NIGHT THROUGH TUESDAY NIGHT...THE COMBINATION OF
STRENGTHENING ONSHORE FLOW AND IN-SITU CAD FROM LIGHT RAIN
OVERSPREADING THE TERMINALS COULD YIELD AN EXTENDED PERIOD OF
MVFR/IFR CONDITIONS (CIGS WOULD BE THE MORE LIKELY CONTRIBUTOR TO
IFR THAN VSBYS) MONDAY NIGHT INTO TUESDAY.

WEDNESDAY...WINDS VEER MORE OUT OF THE SOUTH AS A WARM FRONT SLOWLY
LIFTS NORTHWARD. RAIN IS EXPECTED TO BE THE MOST WIDESPREAD AND
HEAVIEST DURING THIS PART OF THE FORECAST PERIOD. PREDOMINATELY MVFR
AND IFR CONDITIONS. SOUTHERLY WINDS WILL BECOME BREEZY FOLLOWING
WARM FROPA.

WEDNESDAY NIGHT...COLD FRONT IS FORECAST TO MOVE THRU SOMETIME AT
NIGHT. LOW CLOUDS AND RAIN WILL END FROM WEST TO EAST IN WAKE OF
FROPA.

THURSDAY...WESTERLY WINDS COULD BECOME STRONG BEHIND THE FRONT
THURSDAY WITH BUFKIT FORECAST SOUNDINGS FROM THE 12Z GFS SHOWING THE
POTENTIAL FOR 30-40 KT GUSTS.

&&

.MARINE...
WEAK HIGH PRESSURE WILL REMAIN ACROSS THE WATERS TONIGHT AND SUNDAY.
WINDS AND SEAS WILL REMAIN BELOW SCA FLAG CRITERIA. WINDS WILL
MOSTLY BE NORTHERLY THROUGH THE PERIOD.

OUTLOOK...
SUNDAY NIGHT THROUGH MONDAY NIGHT...WINDS AND SEAS BELOW SCA
CRITERIA.

TUESDAY AND TUESDAY NIGHT...ONSHORE FLOW STRENGTHENS ON TUESDAY.
WINDS 15-20 KT FORECAST ON TUESDAY. SEAS ARE FORECAST TO BUILD TO
5-6 FEET TUESDAY AND TUESDAY NIGHT, WARRANTING THE NEED FOR A SCA.

WEDNESDAY AND WEDNESDAY NIGHT...SOUTHERLY WINDS STRENGTHEN AFTER
WARM FROPA. DESPITE WINDS OF 40-50 KT FORECAST 1000 FT ABOVE THE
SURFACE, THERMAL PROFILES NOT FAVORABLE FOR MIXING WITH THE SETUP OF
WARM AIR MOVING ATOP THE COOLER WATERS. EXPECTING MORE OF A HIGH END
SCA WITH 25-30 KT WINDS. WINDS FORECAST TO BECOME WESTERLY LATE
WEDNESDAY NIGHT BEHIND A COLD FRONT BUT THE CORE OF THE COLD AIR
WILL STILL REMAIN UPSTREAM OF THE WATERS. SEAS FORECAST TO INCREASE
TO 6-8 FEET.

THURSDAY...GUSTY WESTERLY WINDS EXPECTED. GALES CERTAINLY A
POSSIBILITY.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...O`HARA
SHORT TERM...O`HARA
LONG TERM...FRANCK
AVIATION...KLEIN/O`HARA
MARINE...KLEIN/O`HARA







000
FXUS61 KAKQ 202100
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
400 PM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL PUSH OFF THE SOUTHEAST COAST TONIGHT...AS HIGH
PRESSURE REMAINS OVER THE LOCAL AREA THROUGH SUNDAY EVENING. ANOTHER
LOW PRESSURE AREA MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP
ALONG THE CAROLINA COAST LATE MONDAY INTO TUESDAY...AS HIGH PRESSURE
DRIFTS OFF THE NEW ENGLAND COAST INTO THE CANADIAN MARITIMES. A COLD
FRONT WILL CROSS THE WEDNESDAY NIGHT WITH HIGH PRESSURE RETURNING
BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
LATEST ANALYSIS SHOWS ~1030 MB SFC HIGH PRESSURE CENTERED OVER
EASTERN CANADA...RIDGING DOWN INTO THE MID ATLC. SFC LOW PRESSURE
SLIDING INTO THE ATLC OFF THE COAST OF NORTHERN FL. DRIER AIR
BEGINNING TO ERODE SOME OF THE CLOUD COVER OVER THE REGION
ALTHOUGH SKIES ARE STILL MOSTLY CLOUDY OVERALL THIS AFTN...WITH
TEMPERATURES MAINLY IN THE UPPER 30S TO LOWER 40S. SPOTTY LIGHT
PRECIP NOW BECOMING CONFINED TO NE NC AND SHOULD MOVE OFFSHORE
OVER THE NEXT FEW HRS. WILL MAINTAIN 20% POPS IN THE FAR SE
ZONES...OTHERWISE WILL HAVE A DRY FORECAST THIS EVENING/OVERNIGHT.
MODEL BUFKIT SOUNDINGS SHOW A FAIR AMOUNT OF LINGERING LOW LEVEL
MOISTURE OVERNIGHT SO NOT CONFIDENT THAT SKIES COMPLETELY CLEAR
OUT OVERNIGHT (WILL GO PARTLY CLOUDY). LOWS WILL RANGE FROM THE
MID 20S OVER MUCH OF THE NORTHERN 1/2 OF THE CWA AWAY FROM THE
COAST...TO THE LOWER 30S OVER SE COASTAL SECTIONS. IF SKIES
COMPLETELY CLEAR OUT MAY SEE TEMPS A FEW DEGREES COLDER THAN THIS.

HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. LIGHT WINDS OVERALL WITH A LIGHT ONSHORE
NE FLOW OVER THE SE COASTAL ZONES...SEASONABLE HIGHS IN THE LOWER-
MID 40S NE TO AROUND 50 F IN SOUTH CENTRAL VA.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
MODELS SHOW NEXT SHORTWAVE TROUGH AMPLIFYING ACRS THE NORTHERN
PLAINS SUN NIGHT/MON...AS STRONG UPPER LEVEL RIDGING HOLDS STRONG
FROM FLORIDA TO THE CARRIBEAN. MID/UPPER LEVEL FLOW PROGGED TO
TURN MORE SW AND THIS WILL HELP STEER LOW PRESSURE NE FROM THE
GULF COAST STATES INTO THE SE AND MID ATLC COASTAL WATERS MON/MON
NIGHT. POSITION OF SFC HIGH TO OUR N...SHIFTING EAST TO THE NEW
ENGLAND COAST BY 12Z/MON IS NOT FAVORABLE FOR LOCKING COLD AIR
OVER THE AKQ CWA. STILL SHOULE SEE ENOUGH COLD AIR INITIALLY OVER
THE REGION SUN NIGHT/MON MORNING DUE TO CLEAR SKIES THROUGH PART
OF THE NIGHT. THIS WILL LEAD TO THE CHC OF A FEW HRS WORTH OF
OVERRUNNING FROZEN PRECIP OVER CLIMO FAVORED PIEDMONT ZONES NW OF
RICHMOND (WITH LITTLE CHC FOR ANYTHING BUT ALL RAIN OVER THE REST
OF THE CWA). LOW LEVEL THICKNESSES (1000-850MB) ARE MARGINAL BUT
BUFKIT SOUNDINGS SHOW A NARROW LAYER OF BELOW FREEZING TEMPS AT
THE SFC FROM ABOUT 09-15Z/MON AT KCHO (AND LIKELY AT KLKU). STILL
SOME QUESTION AS TO HOW FAST PRECIP ARRIVES BUT OVERALL LOOKS LIKE
CHANCES RAMP UP SIGNIFICANTLY DURING THE 09-12Z TIMEFRAME. WILL GO
WITH A CHC FOR SLEET OVER THE PIEDMONT BETWEEN
09-12Z...TRANSITIONING TO SLEET/FREEZING RAIN FROM ABOUT
12-15Z/MON (ALTHOUGH BECOMING CONFINED TO THE FAR NW BY THIS
POINT). IN ANY EVENT...THIS LOOKS LIGHT AS BULK OF DEEPER MOISTURE
LIKELY ARRIVES AFTER A CHANGEOVER TO ALL RAIN. ALSO...NOT
ANTICIPATING TEMPS IN MID 20S...GENLY CLOSER TO 30-32 F...SO
IMPACTS ARE EXPECTED TO BE MINIMAL FOR THE MOST PART.

HIGHS MON ONLY IN THE UPPER 30S/AROUND 40 NW TO THE MID 50S FAR SE IN
CAD SETUP. MAINTAINING LIKELY TO CATEGORICAL POPS THROUGH MON
AFTN...ALTHOUGH QPF AMOUNTS ONLY AVG 0.25-0.50". LOW PRESSURE
LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING FROM
SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION
TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM THE GULF
STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE MAINTAINED.
HIGHS IN THE LOW 60S FAR SE TO THE UPPER 40S NW.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
 A VERY DYNAMIC SYSTEM LIFTS NNE WEST OF THE
APPALACHIANS TUESDAY NIGHT WITH THE ATTENDANT COLD FRONT CROSSING
THE MID-ATLANTIC WEDNESDAY. THE FIRST POTENTIAL OF RAIN ARRIVES
TUESDAY NIGHT ASSOCIATED WITH MOIST WAA. THE SECOND POTENTIAL WILL
BE WEDNESDAY AHEAD OF THE COLD FRONT. THERE IS A POTENTIAL FOR
THUNDER WEDNESDAY AS SURFACE DEWPOINTS POTENTIALLY EXCEED 60F
(ESPECIALLY OVER THE COASTAL PLAIN). THE PATTERN DOES SUPPORT THE
POSSIBILITY OF A DYNAMICALLY FORCED LINE OF CONVECTION CONTAINING
STRONG WIND GUSTS AS CURRENT FORECAST GUIDANCE SUGGESTS A
925-700MB WIND FIELD AVERAGING 40-50KT. THIS WOULD BE A
CLIMATOLOGICALLY RARITY THIS TIME OF YEAR...SO CONFIDENCE IS ON
THE LOW-SIDE GIVEN THAT THIS IS 5-6 DAYS OUT. TEMPERATURES WILL BE
VERY MILD AHEAD OF THE FRONT TUESDAY AND WEDNESDAY...WITH HIGHS
AVERAGING FROM THE MID 50S NW...TO MID/UPPER 60S SE. DRY AND
BREEZY CONDITIONS WILL LIKELY PREVAIL BY CHRISTMAS DAY...WITH HIGH
TEMPERATURES OF 50-55. THE FLOW BECOMES MORE SW BY FRIDAY WITH
CURRENT FORECAST HIGHS OF 55-60...BUT 60-65 IS POSSIBLE BASED ON
LOW-LEVEL THICKNESS FIELDS.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
MOSTLY VFR CONDITIONS EXPECTED ACROSS THE AREA WITH SOME -RA OR
SPRINKLES DEPICTED ON RADAR ACROSS NE NC. HIGH PRESSURE MOVES WEST
OVERNIGHT AS THE WEAK WAVE OFF THE SE US COAST CONTINUES TO PUSH
OUT TO SEA. LIGHT WINDS AND VFR CONDITIONS EXPECTED THROUGH SUN
EVENING BEFORE THE APPROACH OF THE NEXT WAVE MOVING NE FROM THE
GULF OF MEXICO AND UP THE EAST COAST.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY.

&&

.MARINE...
LATEST OBS HIGH PRESSURE SPREADS EAST ACROSS NEW ENGLAND THROUGH
TONIGHT, RIDGING SOUTH INTO THE AREA TODAY. MEANWHILE, WEAK SFC LOW
PRESSURE WILL PASS SOUTH OF THE REGION LATER TODAY AND TONIGHT. THIS
WILL MAINTAIN LIGHT NORTHERLY FLOW ~10 KT OVER THE MARINE AREA
TODAY. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY NIGHT, AS LOW
PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY NIGHT BEFORE
TRACKING NE OFF THE LOWER MID ATLANTIC COAST LATER MONDAY AND MONDAY
NIGHT. THE RESULTANT TIGHTENING SURFACE PRESSURE GRADIENT WILL ALLOW
ONSHORE (EAST) FLOW TO GRADUALLY INCREASE MONDAY AFTN, GRADUALLY
BUILDING SEAS MONDAY NIGHT AND EARLY TUESDAY. 15-20KT EASTERLY FLOW
OVER THE OCEAN AND LOWER BAY COULD PRODUCE A PERIOD OF SCA
CONDITIONS ESPECIALLY OVER THE SRN OCEAN ZONES (MAINLY FOR SEAS) AND
LOWER BAY/MOUTH OF JAMES. THERE IS NO CAA IN THE WAKE OF THIS
LOW...SO SUB-SCA CONDITIONS SHOULD PREVAIL BEHIND THE SYSTEM LATER
MONDAY NIGHT INTO TUESDAY.

A STRONG LOW PRESSURE SYSTEM LOOKS TO DEVELOP ACROSS THE OHIO
VALLEY, TRACKING WEST OF THE MOUNTAINS TUESDAY NIGHT. HOWEVER, THIS
SYSTEM WILL PUSH A STRONG COLD FRONT ACROSS THE MID ATLANTIC COAST
LATER WEDNESDAY. SCA CONDITIONS ARE LIKELY WEDNESDAY NIGHT INTO
CHRISTMAS DAY AS HIGH PRESSURE BUILDS IN FROM THE WNW.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...JDM/LKB
LONG TERM...BMD
AVIATION...MAM/DAP
MARINE...BMD/MAM






000
FXUS61 KAKQ 202100
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
400 PM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL PUSH OFF THE SOUTHEAST COAST TONIGHT...AS HIGH
PRESSURE REMAINS OVER THE LOCAL AREA THROUGH SUNDAY EVENING. ANOTHER
LOW PRESSURE AREA MOVES NORTHEAST OUT OF THE GULF OF MEXICO AND UP
ALONG THE CAROLINA COAST LATE MONDAY INTO TUESDAY...AS HIGH PRESSURE
DRIFTS OFF THE NEW ENGLAND COAST INTO THE CANADIAN MARITIMES. A COLD
FRONT WILL CROSS THE WEDNESDAY NIGHT WITH HIGH PRESSURE RETURNING
BY CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
LATEST ANALYSIS SHOWS ~1030 MB SFC HIGH PRESSURE CENTERED OVER
EASTERN CANADA...RIDGING DOWN INTO THE MID ATLC. SFC LOW PRESSURE
SLIDING INTO THE ATLC OFF THE COAST OF NORTHERN FL. DRIER AIR
BEGINNING TO ERODE SOME OF THE CLOUD COVER OVER THE REGION
ALTHOUGH SKIES ARE STILL MOSTLY CLOUDY OVERALL THIS AFTN...WITH
TEMPERATURES MAINLY IN THE UPPER 30S TO LOWER 40S. SPOTTY LIGHT
PRECIP NOW BECOMING CONFINED TO NE NC AND SHOULD MOVE OFFSHORE
OVER THE NEXT FEW HRS. WILL MAINTAIN 20% POPS IN THE FAR SE
ZONES...OTHERWISE WILL HAVE A DRY FORECAST THIS EVENING/OVERNIGHT.
MODEL BUFKIT SOUNDINGS SHOW A FAIR AMOUNT OF LINGERING LOW LEVEL
MOISTURE OVERNIGHT SO NOT CONFIDENT THAT SKIES COMPLETELY CLEAR
OUT OVERNIGHT (WILL GO PARTLY CLOUDY). LOWS WILL RANGE FROM THE
MID 20S OVER MUCH OF THE NORTHERN 1/2 OF THE CWA AWAY FROM THE
COAST...TO THE LOWER 30S OVER SE COASTAL SECTIONS. IF SKIES
COMPLETELY CLEAR OUT MAY SEE TEMPS A FEW DEGREES COLDER THAN THIS.

HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. LIGHT WINDS OVERALL WITH A LIGHT ONSHORE
NE FLOW OVER THE SE COASTAL ZONES...SEASONABLE HIGHS IN THE LOWER-
MID 40S NE TO AROUND 50 F IN SOUTH CENTRAL VA.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
MODELS SHOW NEXT SHORTWAVE TROUGH AMPLIFYING ACRS THE NORTHERN
PLAINS SUN NIGHT/MON...AS STRONG UPPER LEVEL RIDGING HOLDS STRONG
FROM FLORIDA TO THE CARRIBEAN. MID/UPPER LEVEL FLOW PROGGED TO
TURN MORE SW AND THIS WILL HELP STEER LOW PRESSURE NE FROM THE
GULF COAST STATES INTO THE SE AND MID ATLC COASTAL WATERS MON/MON
NIGHT. POSITION OF SFC HIGH TO OUR N...SHIFTING EAST TO THE NEW
ENGLAND COAST BY 12Z/MON IS NOT FAVORABLE FOR LOCKING COLD AIR
OVER THE AKQ CWA. STILL SHOULE SEE ENOUGH COLD AIR INITIALLY OVER
THE REGION SUN NIGHT/MON MORNING DUE TO CLEAR SKIES THROUGH PART
OF THE NIGHT. THIS WILL LEAD TO THE CHC OF A FEW HRS WORTH OF
OVERRUNNING FROZEN PRECIP OVER CLIMO FAVORED PIEDMONT ZONES NW OF
RICHMOND (WITH LITTLE CHC FOR ANYTHING BUT ALL RAIN OVER THE REST
OF THE CWA). LOW LEVEL THICKNESSES (1000-850MB) ARE MARGINAL BUT
BUFKIT SOUNDINGS SHOW A NARROW LAYER OF BELOW FREEZING TEMPS AT
THE SFC FROM ABOUT 09-15Z/MON AT KCHO (AND LIKELY AT KLKU). STILL
SOME QUESTION AS TO HOW FAST PRECIP ARRIVES BUT OVERALL LOOKS LIKE
CHANCES RAMP UP SIGNIFICANTLY DURING THE 09-12Z TIMEFRAME. WILL GO
WITH A CHC FOR SLEET OVER THE PIEDMONT BETWEEN
09-12Z...TRANSITIONING TO SLEET/FREEZING RAIN FROM ABOUT
12-15Z/MON (ALTHOUGH BECOMING CONFINED TO THE FAR NW BY THIS
POINT). IN ANY EVENT...THIS LOOKS LIGHT AS BULK OF DEEPER MOISTURE
LIKELY ARRIVES AFTER A CHANGEOVER TO ALL RAIN. ALSO...NOT
ANTICIPATING TEMPS IN MID 20S...GENLY CLOSER TO 30-32 F...SO
IMPACTS ARE EXPECTED TO BE MINIMAL FOR THE MOST PART.

HIGHS MON ONLY IN THE UPPER 30S/AROUND 40 NW TO THE MID 50S FAR SE IN
CAD SETUP. MAINTAINING LIKELY TO CATEGORICAL POPS THROUGH MON
AFTN...ALTHOUGH QPF AMOUNTS ONLY AVG 0.25-0.50". LOW PRESSURE
LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING FROM
SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE REGION
TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM THE GULF
STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE MAINTAINED.
HIGHS IN THE LOW 60S FAR SE TO THE UPPER 40S NW.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
 A VERY DYNAMIC SYSTEM LIFTS NNE WEST OF THE
APPALACHIANS TUESDAY NIGHT WITH THE ATTENDANT COLD FRONT CROSSING
THE MID-ATLANTIC WEDNESDAY. THE FIRST POTENTIAL OF RAIN ARRIVES
TUESDAY NIGHT ASSOCIATED WITH MOIST WAA. THE SECOND POTENTIAL WILL
BE WEDNESDAY AHEAD OF THE COLD FRONT. THERE IS A POTENTIAL FOR
THUNDER WEDNESDAY AS SURFACE DEWPOINTS POTENTIALLY EXCEED 60F
(ESPECIALLY OVER THE COASTAL PLAIN). THE PATTERN DOES SUPPORT THE
POSSIBILITY OF A DYNAMICALLY FORCED LINE OF CONVECTION CONTAINING
STRONG WIND GUSTS AS CURRENT FORECAST GUIDANCE SUGGESTS A
925-700MB WIND FIELD AVERAGING 40-50KT. THIS WOULD BE A
CLIMATOLOGICALLY RARITY THIS TIME OF YEAR...SO CONFIDENCE IS ON
THE LOW-SIDE GIVEN THAT THIS IS 5-6 DAYS OUT. TEMPERATURES WILL BE
VERY MILD AHEAD OF THE FRONT TUESDAY AND WEDNESDAY...WITH HIGHS
AVERAGING FROM THE MID 50S NW...TO MID/UPPER 60S SE. DRY AND
BREEZY CONDITIONS WILL LIKELY PREVAIL BY CHRISTMAS DAY...WITH HIGH
TEMPERATURES OF 50-55. THE FLOW BECOMES MORE SW BY FRIDAY WITH
CURRENT FORECAST HIGHS OF 55-60...BUT 60-65 IS POSSIBLE BASED ON
LOW-LEVEL THICKNESS FIELDS.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
MOSTLY VFR CONDITIONS EXPECTED ACROSS THE AREA WITH SOME -RA OR
SPRINKLES DEPICTED ON RADAR ACROSS NE NC. HIGH PRESSURE MOVES WEST
OVERNIGHT AS THE WEAK WAVE OFF THE SE US COAST CONTINUES TO PUSH
OUT TO SEA. LIGHT WINDS AND VFR CONDITIONS EXPECTED THROUGH SUN
EVENING BEFORE THE APPROACH OF THE NEXT WAVE MOVING NE FROM THE
GULF OF MEXICO AND UP THE EAST COAST.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY.

&&

.MARINE...
LATEST OBS HIGH PRESSURE SPREADS EAST ACROSS NEW ENGLAND THROUGH
TONIGHT, RIDGING SOUTH INTO THE AREA TODAY. MEANWHILE, WEAK SFC LOW
PRESSURE WILL PASS SOUTH OF THE REGION LATER TODAY AND TONIGHT. THIS
WILL MAINTAIN LIGHT NORTHERLY FLOW ~10 KT OVER THE MARINE AREA
TODAY. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY NIGHT, AS LOW
PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY NIGHT BEFORE
TRACKING NE OFF THE LOWER MID ATLANTIC COAST LATER MONDAY AND MONDAY
NIGHT. THE RESULTANT TIGHTENING SURFACE PRESSURE GRADIENT WILL ALLOW
ONSHORE (EAST) FLOW TO GRADUALLY INCREASE MONDAY AFTN, GRADUALLY
BUILDING SEAS MONDAY NIGHT AND EARLY TUESDAY. 15-20KT EASTERLY FLOW
OVER THE OCEAN AND LOWER BAY COULD PRODUCE A PERIOD OF SCA
CONDITIONS ESPECIALLY OVER THE SRN OCEAN ZONES (MAINLY FOR SEAS) AND
LOWER BAY/MOUTH OF JAMES. THERE IS NO CAA IN THE WAKE OF THIS
LOW...SO SUB-SCA CONDITIONS SHOULD PREVAIL BEHIND THE SYSTEM LATER
MONDAY NIGHT INTO TUESDAY.

A STRONG LOW PRESSURE SYSTEM LOOKS TO DEVELOP ACROSS THE OHIO
VALLEY, TRACKING WEST OF THE MOUNTAINS TUESDAY NIGHT. HOWEVER, THIS
SYSTEM WILL PUSH A STRONG COLD FRONT ACROSS THE MID ATLANTIC COAST
LATER WEDNESDAY. SCA CONDITIONS ARE LIKELY WEDNESDAY NIGHT INTO
CHRISTMAS DAY AS HIGH PRESSURE BUILDS IN FROM THE WNW.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...JDM/LKB
LONG TERM...BMD
AVIATION...MAM/DAP
MARINE...BMD/MAM







000
FXUS61 KLWX 201932
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
232 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST THROUGH SUNDAY. LOW PRESSURE WILL
TRACK UP THE MID-ATLANTIC COAST LATE MONDAY. A STRONG COLD FRONT
WILL THEN PASS THROUGH THE AREA LATE WEDNESDAY INTO WEDNESDAY
NIGHT.

&&

.NEAR TERM /THROUGH SUNDAY/...
A SHORTWAVE WILL PASS THROUGH THE REGION THIS AFTERNOON...CAUSING
HIGH AND MID-LEVEL CLOUDS WHILE SURFACE HIGH PRESSURE BUILDS
OVERHEAD. SEASONABLY CHILLY CONDITIONS WILL CONTINUE...BUT THE
DEEP MOISTURE FROM THIS SYSTEM IS EXPECTED TO REMAIN TO OUR SOUTH.
THEREFORE...MOST AREAS WILL TURN OUT DRY. MAX TEMPS WILL RANGE
FROM THE UPPER 20S TO LOWER 30S IN THE MOUNTAINS TO THE UPPER
30S/NEAR 40 IN WASHINGTON AND BALTIMORE.

HIGH PRESSURE WILL REMAIN OVER THE REGION TONIGHT WHILE ANOTHER
UPPER-LEVEL DISTURBANCE PASSES THROUGH THE AREA IN THE WESTERLY
FLOW ALOFT. A BKN DECK OF MID-LEVEL CLOUDS IS EXPECTED...BUT
MOISTURE WILL REMAIN TO OUR SOUTH SO DRY WEATHER IS EXPECTED.
CLOUDS MAY BREAK OUT TOWARD MORNING BEHIND THE DISTURBANCE...AND
WITH HIGH PRESSURE OVERHEAD THIS COULD LEAD RADIATIONAL COOLING.
THEREFORE...MIN TEMPS HAVE BEEN TAKEN DOWN A FEW DEGREES CLOSER TO
THE MAV GUIDANCE. MIN TEMPS WILL RANGE FROM THE LOWER AND MIDDLE
20S ACROSS MOST LOCATIONS TO THE LOWER AND MIDDLE 30S IN DOWNTOWN
WASHINGTON AND BALTIMORE.

HIGH PRESSURE WILL REMAIN OVER THE REGION FOR WEDNESDAY AND AN
UPPER-LEVEL RIDGE WILL BUILD OVERHEAD BEHIND A DEPARTING
DISTURBANCE. THIS WILL ALLOW FOR PLENTY OF SUNSHINE...BUT
SEASONABLY CHILLY CONDITIONS WILL CONTINUE.


&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
UPPER TROUGH WILL BEGIN TO AMPLIFY OVER THE EASTERN U.S ON MONDAY.
UPPER LEVEL JET/DYNAMICS SHIFT EAST TO THE COAST WHERE AN AREA OF
LOW PRESSURE IS LIKELY TO DEVELOP OVER THE CAROLINAS AND TRACK
SLOWLY NORTH INTO MONDAY NIGHT. TIMING OF PRECIPITATION IS STILL A
BIT UNCERTAIN WITHIN THE NAM/GFS/EURO SOLUTIONS WITH THE NAM BEING
THE MOST BULLISH AND QUICKEST TO ARRIVE VS THE SLOWER GFS AND EURO.
EITHER WAY...TEMPERATURES WILL BE CRUCIAL WITH COLD HIGH PRESSURE
OVER NEW ENGLAND PROVIDING CAD WEDGE OVER THE MIDDLE ATLANTIC TO
START THE EVENT. IF PRECIPITATION BEGINS EARLIER IN THE DAY AS PER
THE 12Z NAM THERE COULD BE MORE OF AN ZR/IP THREAT EVEN OVER SOME OF
THE IMMEDIATE SUBURBS NORTH AND WEST OF DC/BWI THE FIRST PART OF
MONDAY. IT IS TYPICAL FOR GUIDANCE TO ERODE THE CAD WEDGE TOO
QUICKLY IN SITUATIONS LIKE THIS. HAVE UNDERCUT TEMPERATURES A FEW
DEGREES FROM INHERITED NUMBERS AND EXPANDED ZR/IP A BIT EAST AS
WELL. MILDER AIR WILL GRADUALLY CHANGE THE ICE TO RAIN EAST OF THE
BLUE RIDGE BUT A LONGER PERIOD OF ZR/IP MAY OCCUR WEST OF THE BLUE
RIDGE IN THE NORMALLY COLDER LOCALES. WILL CONTINUE TO HIGHLIGHT
POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK.

ENOUGH WARMER AIR SHOULD WORK IN AND CHANGE MUCH OF THE PRECIP TO
RAIN MONDAY NIGHT ALTHOUGH THERE COULD STILL BE A FEW POCKETS OF ZR
OVER THE HIGHER ELEVATIONS WITHIN THE HIGHLANDS.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
A WARM FRONT WILL INCH ITS WAY NORTHWARD FROM THE CAROLINAS TO THE
MID ATLANTIC COAST TUESDAY AND TUESDAY NIGHT. SOME STRATIFORM LIGHT
TO MODERATE RAIN WILL PRECEDE THE WARM FRONT AND OVERRUN THE ENTIRE
REGION.

THROUGH THE DAY WEDNESDAY...AS THE WARM FRONT WORKS ITS WAY NORTH OF
THE MASON-DIXON LINE...A POTENT STORM SYSTEM WILL BE PIVOTING
NORTHEASTWARD FROM THE OHIO VALLEY INTO THE EASTERN GREAT LAKES
REGION. ITS ASSOCIATED COLD FRONT WILL TRAIL SOUTHWARD AND POSSIBLY
WORK INTO THE POTOMAC HIGHLANDS AND SHENANDOAH VALLEY BY LATER IN
THE DAY WEDNESDAY. THIS COLD FRONT SHOULD MOVE ACROSS THE DELMARVA
PENINSULA AND THEN OFFSHORE WEDNESDAY NIGHT. PROBABILITY OF RAIN
REMAINS HIGH...NEAR 90 TO 100 PERCENT. THE RAIN EXPECTED LOOKS TO BE
MORE CONVECTIVE IN NATURE AHEAD OF THE COLD FRONT AND POTENT STORM
SYSTEM. HIGH TEMPERATURES WEDNESDAY WILL BE 15 TO 20 DEGREES ABOVE
NORMAL AS WE ENCOUNTER MOST LOCATIONS REACHING NEAR 60 TO THE LOWER
60S...MAINLY EAST OF THE BLUE RIDGE MOUNTAINS. WE WILL LEAVE A
CHANCE OF RAIN SHOWERS IN THE FORECAST FOR WEDNESDAY NIGHT
CONSIDERING SOME UNCERTAINTY ON THE TIMING OF COLD FRONTAL PASSAGE.
NONETHELESS...COLDER AND DRIER AIR WILL FILTER INTO THE REGION FROM
WEST TO EAST WEDNESDAY NIGHT...ALLOWING FOR TEMPERATURES TO QUICKLY FALL
THROUGH THE 50S INTO THE 40S.

THERE IS A CHANCE FOR SOME SNOW SHOWERS IN THE HIGHER ELEVATIONS OF
THE POTOMAC HIGHLANDS THURSDAY...PERHAPS ABOVE 2500 FEET. ALTHOUGH
TEMPERATURES WILL BE SOME 10 TO 15 COOLER THAN
WEDNESDAY...TEMPERATURES WILL STILL BE SLIGHTLY ABOVE NORMAL.

DRY CONDITIONS FRIDAY WITH HIGH PRESSURE BUILDING JUST TO OUR SOUTH.
HIGH TEMPERATURES MAY STILL BE SLIGHTLY ABOVE NORMAL WITH A GOOD BIT
OF SUNSHINE.

ANOTHER COLD FRONT COULD BRING A CHANCE FOR RAIN AND SNOW SHOWERS TO
THE REGION FRIDAY NIGHT INTO SATURDAY.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS THROUGH
SUNDAY...BRINGING VFR CONDITIONS. CLOUDS WILL INCREASE SUNDAY
NIGHT AND SUBVFR CONDITIONS ARE POSSIBLE TOWARD MONDAY MORNING.

CONDITIONS WILL DETERIORATE MONDAY INTO MONDAY NIGHT WITH SUB VFR
CIGS AND VSBYS. PRECIPITATION TYPE IS A BIT UNCERTAIN ALTHOUGH
EXPECTING MOSTLY LIQUID AT KDCA AND KBWI. NORTH AND WEST COULD SEE A
WINTRY MIX OF FREEZING RAIN AND SLEET FOR PART OF MONDAY. ALL RAIN
EXPECTED MONDAY NIGHT.

IFR OR LIFR CONDITIONS ARE POSSIBLE TUESDAY AND TUESDAY NIGHT
WITH LOW CLOUDS AND PERIODS OF RAIN. WINDS LIGHT AND VARIABLE. IFR
OR LIFR CONDITIONS ARE POSSIBLE AGAIN WEDNESDAY WITH NUMEROUS
GUSTY RAIN SHOWERS AHEAD OF A COLD FRONT. WINDS SOUTHEAST TO SOUTH
5 TO 10 KNOTS WEDNESDAY...INCREASING SOUTHWEST WEDNESDAY NIGHT.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS THROUGH SUNDAY NIGHT. NO
MARINE HAZARDS ARE EXPECTED DURING THIS TIME.

WINDS COULD APPROACH SCA CRITERIA LATER MONDAY INTO EARLY TUESDAY AS
LOW PRESSURE APPROACHES FROM THE SOUTH.

NO MARINE HAZARDS TUESDAY AND TUESDAY NIGHT. SMALL CRAFT ADVISORIES
MAY BE NEEDED WEDNESDAY WITH GUSTS TO 20 KNOTS.
&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BJL
NEAR TERM...BJL
SHORT TERM...BJL/KRW
LONG TERM...KLW
AVIATION...BJL/KLW/KRW
MARINE...BJL/KLW/KRW







000
FXUS61 KLWX 201932
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
232 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST THROUGH SUNDAY. LOW PRESSURE WILL
TRACK UP THE MID-ATLANTIC COAST LATE MONDAY. A STRONG COLD FRONT
WILL THEN PASS THROUGH THE AREA LATE WEDNESDAY INTO WEDNESDAY
NIGHT.

&&

.NEAR TERM /THROUGH SUNDAY/...
A SHORTWAVE WILL PASS THROUGH THE REGION THIS AFTERNOON...CAUSING
HIGH AND MID-LEVEL CLOUDS WHILE SURFACE HIGH PRESSURE BUILDS
OVERHEAD. SEASONABLY CHILLY CONDITIONS WILL CONTINUE...BUT THE
DEEP MOISTURE FROM THIS SYSTEM IS EXPECTED TO REMAIN TO OUR SOUTH.
THEREFORE...MOST AREAS WILL TURN OUT DRY. MAX TEMPS WILL RANGE
FROM THE UPPER 20S TO LOWER 30S IN THE MOUNTAINS TO THE UPPER
30S/NEAR 40 IN WASHINGTON AND BALTIMORE.

HIGH PRESSURE WILL REMAIN OVER THE REGION TONIGHT WHILE ANOTHER
UPPER-LEVEL DISTURBANCE PASSES THROUGH THE AREA IN THE WESTERLY
FLOW ALOFT. A BKN DECK OF MID-LEVEL CLOUDS IS EXPECTED...BUT
MOISTURE WILL REMAIN TO OUR SOUTH SO DRY WEATHER IS EXPECTED.
CLOUDS MAY BREAK OUT TOWARD MORNING BEHIND THE DISTURBANCE...AND
WITH HIGH PRESSURE OVERHEAD THIS COULD LEAD RADIATIONAL COOLING.
THEREFORE...MIN TEMPS HAVE BEEN TAKEN DOWN A FEW DEGREES CLOSER TO
THE MAV GUIDANCE. MIN TEMPS WILL RANGE FROM THE LOWER AND MIDDLE
20S ACROSS MOST LOCATIONS TO THE LOWER AND MIDDLE 30S IN DOWNTOWN
WASHINGTON AND BALTIMORE.

HIGH PRESSURE WILL REMAIN OVER THE REGION FOR WEDNESDAY AND AN
UPPER-LEVEL RIDGE WILL BUILD OVERHEAD BEHIND A DEPARTING
DISTURBANCE. THIS WILL ALLOW FOR PLENTY OF SUNSHINE...BUT
SEASONABLY CHILLY CONDITIONS WILL CONTINUE.


&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
UPPER TROUGH WILL BEGIN TO AMPLIFY OVER THE EASTERN U.S ON MONDAY.
UPPER LEVEL JET/DYNAMICS SHIFT EAST TO THE COAST WHERE AN AREA OF
LOW PRESSURE IS LIKELY TO DEVELOP OVER THE CAROLINAS AND TRACK
SLOWLY NORTH INTO MONDAY NIGHT. TIMING OF PRECIPITATION IS STILL A
BIT UNCERTAIN WITHIN THE NAM/GFS/EURO SOLUTIONS WITH THE NAM BEING
THE MOST BULLISH AND QUICKEST TO ARRIVE VS THE SLOWER GFS AND EURO.
EITHER WAY...TEMPERATURES WILL BE CRUCIAL WITH COLD HIGH PRESSURE
OVER NEW ENGLAND PROVIDING CAD WEDGE OVER THE MIDDLE ATLANTIC TO
START THE EVENT. IF PRECIPITATION BEGINS EARLIER IN THE DAY AS PER
THE 12Z NAM THERE COULD BE MORE OF AN ZR/IP THREAT EVEN OVER SOME OF
THE IMMEDIATE SUBURBS NORTH AND WEST OF DC/BWI THE FIRST PART OF
MONDAY. IT IS TYPICAL FOR GUIDANCE TO ERODE THE CAD WEDGE TOO
QUICKLY IN SITUATIONS LIKE THIS. HAVE UNDERCUT TEMPERATURES A FEW
DEGREES FROM INHERITED NUMBERS AND EXPANDED ZR/IP A BIT EAST AS
WELL. MILDER AIR WILL GRADUALLY CHANGE THE ICE TO RAIN EAST OF THE
BLUE RIDGE BUT A LONGER PERIOD OF ZR/IP MAY OCCUR WEST OF THE BLUE
RIDGE IN THE NORMALLY COLDER LOCALES. WILL CONTINUE TO HIGHLIGHT
POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK.

ENOUGH WARMER AIR SHOULD WORK IN AND CHANGE MUCH OF THE PRECIP TO
RAIN MONDAY NIGHT ALTHOUGH THERE COULD STILL BE A FEW POCKETS OF ZR
OVER THE HIGHER ELEVATIONS WITHIN THE HIGHLANDS.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
A WARM FRONT WILL INCH ITS WAY NORTHWARD FROM THE CAROLINAS TO THE
MID ATLANTIC COAST TUESDAY AND TUESDAY NIGHT. SOME STRATIFORM LIGHT
TO MODERATE RAIN WILL PRECEDE THE WARM FRONT AND OVERRUN THE ENTIRE
REGION.

THROUGH THE DAY WEDNESDAY...AS THE WARM FRONT WORKS ITS WAY NORTH OF
THE MASON-DIXON LINE...A POTENT STORM SYSTEM WILL BE PIVOTING
NORTHEASTWARD FROM THE OHIO VALLEY INTO THE EASTERN GREAT LAKES
REGION. ITS ASSOCIATED COLD FRONT WILL TRAIL SOUTHWARD AND POSSIBLY
WORK INTO THE POTOMAC HIGHLANDS AND SHENANDOAH VALLEY BY LATER IN
THE DAY WEDNESDAY. THIS COLD FRONT SHOULD MOVE ACROSS THE DELMARVA
PENINSULA AND THEN OFFSHORE WEDNESDAY NIGHT. PROBABILITY OF RAIN
REMAINS HIGH...NEAR 90 TO 100 PERCENT. THE RAIN EXPECTED LOOKS TO BE
MORE CONVECTIVE IN NATURE AHEAD OF THE COLD FRONT AND POTENT STORM
SYSTEM. HIGH TEMPERATURES WEDNESDAY WILL BE 15 TO 20 DEGREES ABOVE
NORMAL AS WE ENCOUNTER MOST LOCATIONS REACHING NEAR 60 TO THE LOWER
60S...MAINLY EAST OF THE BLUE RIDGE MOUNTAINS. WE WILL LEAVE A
CHANCE OF RAIN SHOWERS IN THE FORECAST FOR WEDNESDAY NIGHT
CONSIDERING SOME UNCERTAINTY ON THE TIMING OF COLD FRONTAL PASSAGE.
NONETHELESS...COLDER AND DRIER AIR WILL FILTER INTO THE REGION FROM
WEST TO EAST WEDNESDAY NIGHT...ALLOWING FOR TEMPERATURES TO QUICKLY FALL
THROUGH THE 50S INTO THE 40S.

THERE IS A CHANCE FOR SOME SNOW SHOWERS IN THE HIGHER ELEVATIONS OF
THE POTOMAC HIGHLANDS THURSDAY...PERHAPS ABOVE 2500 FEET. ALTHOUGH
TEMPERATURES WILL BE SOME 10 TO 15 COOLER THAN
WEDNESDAY...TEMPERATURES WILL STILL BE SLIGHTLY ABOVE NORMAL.

DRY CONDITIONS FRIDAY WITH HIGH PRESSURE BUILDING JUST TO OUR SOUTH.
HIGH TEMPERATURES MAY STILL BE SLIGHTLY ABOVE NORMAL WITH A GOOD BIT
OF SUNSHINE.

ANOTHER COLD FRONT COULD BRING A CHANCE FOR RAIN AND SNOW SHOWERS TO
THE REGION FRIDAY NIGHT INTO SATURDAY.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS THROUGH
SUNDAY...BRINGING VFR CONDITIONS. CLOUDS WILL INCREASE SUNDAY
NIGHT AND SUBVFR CONDITIONS ARE POSSIBLE TOWARD MONDAY MORNING.

CONDITIONS WILL DETERIORATE MONDAY INTO MONDAY NIGHT WITH SUB VFR
CIGS AND VSBYS. PRECIPITATION TYPE IS A BIT UNCERTAIN ALTHOUGH
EXPECTING MOSTLY LIQUID AT KDCA AND KBWI. NORTH AND WEST COULD SEE A
WINTRY MIX OF FREEZING RAIN AND SLEET FOR PART OF MONDAY. ALL RAIN
EXPECTED MONDAY NIGHT.

IFR OR LIFR CONDITIONS ARE POSSIBLE TUESDAY AND TUESDAY NIGHT
WITH LOW CLOUDS AND PERIODS OF RAIN. WINDS LIGHT AND VARIABLE. IFR
OR LIFR CONDITIONS ARE POSSIBLE AGAIN WEDNESDAY WITH NUMEROUS
GUSTY RAIN SHOWERS AHEAD OF A COLD FRONT. WINDS SOUTHEAST TO SOUTH
5 TO 10 KNOTS WEDNESDAY...INCREASING SOUTHWEST WEDNESDAY NIGHT.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS THROUGH SUNDAY NIGHT. NO
MARINE HAZARDS ARE EXPECTED DURING THIS TIME.

WINDS COULD APPROACH SCA CRITERIA LATER MONDAY INTO EARLY TUESDAY AS
LOW PRESSURE APPROACHES FROM THE SOUTH.

NO MARINE HAZARDS TUESDAY AND TUESDAY NIGHT. SMALL CRAFT ADVISORIES
MAY BE NEEDED WEDNESDAY WITH GUSTS TO 20 KNOTS.
&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BJL
NEAR TERM...BJL
SHORT TERM...BJL/KRW
LONG TERM...KLW
AVIATION...BJL/KLW/KRW
MARINE...BJL/KLW/KRW







000
FXUS61 KLWX 201932
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
232 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST THROUGH SUNDAY. LOW PRESSURE WILL
TRACK UP THE MID-ATLANTIC COAST LATE MONDAY. A STRONG COLD FRONT
WILL THEN PASS THROUGH THE AREA LATE WEDNESDAY INTO WEDNESDAY
NIGHT.

&&

.NEAR TERM /THROUGH SUNDAY/...
A SHORTWAVE WILL PASS THROUGH THE REGION THIS AFTERNOON...CAUSING
HIGH AND MID-LEVEL CLOUDS WHILE SURFACE HIGH PRESSURE BUILDS
OVERHEAD. SEASONABLY CHILLY CONDITIONS WILL CONTINUE...BUT THE
DEEP MOISTURE FROM THIS SYSTEM IS EXPECTED TO REMAIN TO OUR SOUTH.
THEREFORE...MOST AREAS WILL TURN OUT DRY. MAX TEMPS WILL RANGE
FROM THE UPPER 20S TO LOWER 30S IN THE MOUNTAINS TO THE UPPER
30S/NEAR 40 IN WASHINGTON AND BALTIMORE.

HIGH PRESSURE WILL REMAIN OVER THE REGION TONIGHT WHILE ANOTHER
UPPER-LEVEL DISTURBANCE PASSES THROUGH THE AREA IN THE WESTERLY
FLOW ALOFT. A BKN DECK OF MID-LEVEL CLOUDS IS EXPECTED...BUT
MOISTURE WILL REMAIN TO OUR SOUTH SO DRY WEATHER IS EXPECTED.
CLOUDS MAY BREAK OUT TOWARD MORNING BEHIND THE DISTURBANCE...AND
WITH HIGH PRESSURE OVERHEAD THIS COULD LEAD RADIATIONAL COOLING.
THEREFORE...MIN TEMPS HAVE BEEN TAKEN DOWN A FEW DEGREES CLOSER TO
THE MAV GUIDANCE. MIN TEMPS WILL RANGE FROM THE LOWER AND MIDDLE
20S ACROSS MOST LOCATIONS TO THE LOWER AND MIDDLE 30S IN DOWNTOWN
WASHINGTON AND BALTIMORE.

HIGH PRESSURE WILL REMAIN OVER THE REGION FOR WEDNESDAY AND AN
UPPER-LEVEL RIDGE WILL BUILD OVERHEAD BEHIND A DEPARTING
DISTURBANCE. THIS WILL ALLOW FOR PLENTY OF SUNSHINE...BUT
SEASONABLY CHILLY CONDITIONS WILL CONTINUE.


&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
UPPER TROUGH WILL BEGIN TO AMPLIFY OVER THE EASTERN U.S ON MONDAY.
UPPER LEVEL JET/DYNAMICS SHIFT EAST TO THE COAST WHERE AN AREA OF
LOW PRESSURE IS LIKELY TO DEVELOP OVER THE CAROLINAS AND TRACK
SLOWLY NORTH INTO MONDAY NIGHT. TIMING OF PRECIPITATION IS STILL A
BIT UNCERTAIN WITHIN THE NAM/GFS/EURO SOLUTIONS WITH THE NAM BEING
THE MOST BULLISH AND QUICKEST TO ARRIVE VS THE SLOWER GFS AND EURO.
EITHER WAY...TEMPERATURES WILL BE CRUCIAL WITH COLD HIGH PRESSURE
OVER NEW ENGLAND PROVIDING CAD WEDGE OVER THE MIDDLE ATLANTIC TO
START THE EVENT. IF PRECIPITATION BEGINS EARLIER IN THE DAY AS PER
THE 12Z NAM THERE COULD BE MORE OF AN ZR/IP THREAT EVEN OVER SOME OF
THE IMMEDIATE SUBURBS NORTH AND WEST OF DC/BWI THE FIRST PART OF
MONDAY. IT IS TYPICAL FOR GUIDANCE TO ERODE THE CAD WEDGE TOO
QUICKLY IN SITUATIONS LIKE THIS. HAVE UNDERCUT TEMPERATURES A FEW
DEGREES FROM INHERITED NUMBERS AND EXPANDED ZR/IP A BIT EAST AS
WELL. MILDER AIR WILL GRADUALLY CHANGE THE ICE TO RAIN EAST OF THE
BLUE RIDGE BUT A LONGER PERIOD OF ZR/IP MAY OCCUR WEST OF THE BLUE
RIDGE IN THE NORMALLY COLDER LOCALES. WILL CONTINUE TO HIGHLIGHT
POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK.

ENOUGH WARMER AIR SHOULD WORK IN AND CHANGE MUCH OF THE PRECIP TO
RAIN MONDAY NIGHT ALTHOUGH THERE COULD STILL BE A FEW POCKETS OF ZR
OVER THE HIGHER ELEVATIONS WITHIN THE HIGHLANDS.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
A WARM FRONT WILL INCH ITS WAY NORTHWARD FROM THE CAROLINAS TO THE
MID ATLANTIC COAST TUESDAY AND TUESDAY NIGHT. SOME STRATIFORM LIGHT
TO MODERATE RAIN WILL PRECEDE THE WARM FRONT AND OVERRUN THE ENTIRE
REGION.

THROUGH THE DAY WEDNESDAY...AS THE WARM FRONT WORKS ITS WAY NORTH OF
THE MASON-DIXON LINE...A POTENT STORM SYSTEM WILL BE PIVOTING
NORTHEASTWARD FROM THE OHIO VALLEY INTO THE EASTERN GREAT LAKES
REGION. ITS ASSOCIATED COLD FRONT WILL TRAIL SOUTHWARD AND POSSIBLY
WORK INTO THE POTOMAC HIGHLANDS AND SHENANDOAH VALLEY BY LATER IN
THE DAY WEDNESDAY. THIS COLD FRONT SHOULD MOVE ACROSS THE DELMARVA
PENINSULA AND THEN OFFSHORE WEDNESDAY NIGHT. PROBABILITY OF RAIN
REMAINS HIGH...NEAR 90 TO 100 PERCENT. THE RAIN EXPECTED LOOKS TO BE
MORE CONVECTIVE IN NATURE AHEAD OF THE COLD FRONT AND POTENT STORM
SYSTEM. HIGH TEMPERATURES WEDNESDAY WILL BE 15 TO 20 DEGREES ABOVE
NORMAL AS WE ENCOUNTER MOST LOCATIONS REACHING NEAR 60 TO THE LOWER
60S...MAINLY EAST OF THE BLUE RIDGE MOUNTAINS. WE WILL LEAVE A
CHANCE OF RAIN SHOWERS IN THE FORECAST FOR WEDNESDAY NIGHT
CONSIDERING SOME UNCERTAINTY ON THE TIMING OF COLD FRONTAL PASSAGE.
NONETHELESS...COLDER AND DRIER AIR WILL FILTER INTO THE REGION FROM
WEST TO EAST WEDNESDAY NIGHT...ALLOWING FOR TEMPERATURES TO QUICKLY FALL
THROUGH THE 50S INTO THE 40S.

THERE IS A CHANCE FOR SOME SNOW SHOWERS IN THE HIGHER ELEVATIONS OF
THE POTOMAC HIGHLANDS THURSDAY...PERHAPS ABOVE 2500 FEET. ALTHOUGH
TEMPERATURES WILL BE SOME 10 TO 15 COOLER THAN
WEDNESDAY...TEMPERATURES WILL STILL BE SLIGHTLY ABOVE NORMAL.

DRY CONDITIONS FRIDAY WITH HIGH PRESSURE BUILDING JUST TO OUR SOUTH.
HIGH TEMPERATURES MAY STILL BE SLIGHTLY ABOVE NORMAL WITH A GOOD BIT
OF SUNSHINE.

ANOTHER COLD FRONT COULD BRING A CHANCE FOR RAIN AND SNOW SHOWERS TO
THE REGION FRIDAY NIGHT INTO SATURDAY.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS THROUGH
SUNDAY...BRINGING VFR CONDITIONS. CLOUDS WILL INCREASE SUNDAY
NIGHT AND SUBVFR CONDITIONS ARE POSSIBLE TOWARD MONDAY MORNING.

CONDITIONS WILL DETERIORATE MONDAY INTO MONDAY NIGHT WITH SUB VFR
CIGS AND VSBYS. PRECIPITATION TYPE IS A BIT UNCERTAIN ALTHOUGH
EXPECTING MOSTLY LIQUID AT KDCA AND KBWI. NORTH AND WEST COULD SEE A
WINTRY MIX OF FREEZING RAIN AND SLEET FOR PART OF MONDAY. ALL RAIN
EXPECTED MONDAY NIGHT.

IFR OR LIFR CONDITIONS ARE POSSIBLE TUESDAY AND TUESDAY NIGHT
WITH LOW CLOUDS AND PERIODS OF RAIN. WINDS LIGHT AND VARIABLE. IFR
OR LIFR CONDITIONS ARE POSSIBLE AGAIN WEDNESDAY WITH NUMEROUS
GUSTY RAIN SHOWERS AHEAD OF A COLD FRONT. WINDS SOUTHEAST TO SOUTH
5 TO 10 KNOTS WEDNESDAY...INCREASING SOUTHWEST WEDNESDAY NIGHT.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS THROUGH SUNDAY NIGHT. NO
MARINE HAZARDS ARE EXPECTED DURING THIS TIME.

WINDS COULD APPROACH SCA CRITERIA LATER MONDAY INTO EARLY TUESDAY AS
LOW PRESSURE APPROACHES FROM THE SOUTH.

NO MARINE HAZARDS TUESDAY AND TUESDAY NIGHT. SMALL CRAFT ADVISORIES
MAY BE NEEDED WEDNESDAY WITH GUSTS TO 20 KNOTS.
&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BJL
NEAR TERM...BJL
SHORT TERM...BJL/KRW
LONG TERM...KLW
AVIATION...BJL/KLW/KRW
MARINE...BJL/KLW/KRW







000
FXUS61 KLWX 201932
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
232 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST THROUGH SUNDAY. LOW PRESSURE WILL
TRACK UP THE MID-ATLANTIC COAST LATE MONDAY. A STRONG COLD FRONT
WILL THEN PASS THROUGH THE AREA LATE WEDNESDAY INTO WEDNESDAY
NIGHT.

&&

.NEAR TERM /THROUGH SUNDAY/...
A SHORTWAVE WILL PASS THROUGH THE REGION THIS AFTERNOON...CAUSING
HIGH AND MID-LEVEL CLOUDS WHILE SURFACE HIGH PRESSURE BUILDS
OVERHEAD. SEASONABLY CHILLY CONDITIONS WILL CONTINUE...BUT THE
DEEP MOISTURE FROM THIS SYSTEM IS EXPECTED TO REMAIN TO OUR SOUTH.
THEREFORE...MOST AREAS WILL TURN OUT DRY. MAX TEMPS WILL RANGE
FROM THE UPPER 20S TO LOWER 30S IN THE MOUNTAINS TO THE UPPER
30S/NEAR 40 IN WASHINGTON AND BALTIMORE.

HIGH PRESSURE WILL REMAIN OVER THE REGION TONIGHT WHILE ANOTHER
UPPER-LEVEL DISTURBANCE PASSES THROUGH THE AREA IN THE WESTERLY
FLOW ALOFT. A BKN DECK OF MID-LEVEL CLOUDS IS EXPECTED...BUT
MOISTURE WILL REMAIN TO OUR SOUTH SO DRY WEATHER IS EXPECTED.
CLOUDS MAY BREAK OUT TOWARD MORNING BEHIND THE DISTURBANCE...AND
WITH HIGH PRESSURE OVERHEAD THIS COULD LEAD RADIATIONAL COOLING.
THEREFORE...MIN TEMPS HAVE BEEN TAKEN DOWN A FEW DEGREES CLOSER TO
THE MAV GUIDANCE. MIN TEMPS WILL RANGE FROM THE LOWER AND MIDDLE
20S ACROSS MOST LOCATIONS TO THE LOWER AND MIDDLE 30S IN DOWNTOWN
WASHINGTON AND BALTIMORE.

HIGH PRESSURE WILL REMAIN OVER THE REGION FOR WEDNESDAY AND AN
UPPER-LEVEL RIDGE WILL BUILD OVERHEAD BEHIND A DEPARTING
DISTURBANCE. THIS WILL ALLOW FOR PLENTY OF SUNSHINE...BUT
SEASONABLY CHILLY CONDITIONS WILL CONTINUE.


&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
UPPER TROUGH WILL BEGIN TO AMPLIFY OVER THE EASTERN U.S ON MONDAY.
UPPER LEVEL JET/DYNAMICS SHIFT EAST TO THE COAST WHERE AN AREA OF
LOW PRESSURE IS LIKELY TO DEVELOP OVER THE CAROLINAS AND TRACK
SLOWLY NORTH INTO MONDAY NIGHT. TIMING OF PRECIPITATION IS STILL A
BIT UNCERTAIN WITHIN THE NAM/GFS/EURO SOLUTIONS WITH THE NAM BEING
THE MOST BULLISH AND QUICKEST TO ARRIVE VS THE SLOWER GFS AND EURO.
EITHER WAY...TEMPERATURES WILL BE CRUCIAL WITH COLD HIGH PRESSURE
OVER NEW ENGLAND PROVIDING CAD WEDGE OVER THE MIDDLE ATLANTIC TO
START THE EVENT. IF PRECIPITATION BEGINS EARLIER IN THE DAY AS PER
THE 12Z NAM THERE COULD BE MORE OF AN ZR/IP THREAT EVEN OVER SOME OF
THE IMMEDIATE SUBURBS NORTH AND WEST OF DC/BWI THE FIRST PART OF
MONDAY. IT IS TYPICAL FOR GUIDANCE TO ERODE THE CAD WEDGE TOO
QUICKLY IN SITUATIONS LIKE THIS. HAVE UNDERCUT TEMPERATURES A FEW
DEGREES FROM INHERITED NUMBERS AND EXPANDED ZR/IP A BIT EAST AS
WELL. MILDER AIR WILL GRADUALLY CHANGE THE ICE TO RAIN EAST OF THE
BLUE RIDGE BUT A LONGER PERIOD OF ZR/IP MAY OCCUR WEST OF THE BLUE
RIDGE IN THE NORMALLY COLDER LOCALES. WILL CONTINUE TO HIGHLIGHT
POTENTIAL IN THE HAZARDOUS WEATHER OUTLOOK.

ENOUGH WARMER AIR SHOULD WORK IN AND CHANGE MUCH OF THE PRECIP TO
RAIN MONDAY NIGHT ALTHOUGH THERE COULD STILL BE A FEW POCKETS OF ZR
OVER THE HIGHER ELEVATIONS WITHIN THE HIGHLANDS.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
A WARM FRONT WILL INCH ITS WAY NORTHWARD FROM THE CAROLINAS TO THE
MID ATLANTIC COAST TUESDAY AND TUESDAY NIGHT. SOME STRATIFORM LIGHT
TO MODERATE RAIN WILL PRECEDE THE WARM FRONT AND OVERRUN THE ENTIRE
REGION.

THROUGH THE DAY WEDNESDAY...AS THE WARM FRONT WORKS ITS WAY NORTH OF
THE MASON-DIXON LINE...A POTENT STORM SYSTEM WILL BE PIVOTING
NORTHEASTWARD FROM THE OHIO VALLEY INTO THE EASTERN GREAT LAKES
REGION. ITS ASSOCIATED COLD FRONT WILL TRAIL SOUTHWARD AND POSSIBLY
WORK INTO THE POTOMAC HIGHLANDS AND SHENANDOAH VALLEY BY LATER IN
THE DAY WEDNESDAY. THIS COLD FRONT SHOULD MOVE ACROSS THE DELMARVA
PENINSULA AND THEN OFFSHORE WEDNESDAY NIGHT. PROBABILITY OF RAIN
REMAINS HIGH...NEAR 90 TO 100 PERCENT. THE RAIN EXPECTED LOOKS TO BE
MORE CONVECTIVE IN NATURE AHEAD OF THE COLD FRONT AND POTENT STORM
SYSTEM. HIGH TEMPERATURES WEDNESDAY WILL BE 15 TO 20 DEGREES ABOVE
NORMAL AS WE ENCOUNTER MOST LOCATIONS REACHING NEAR 60 TO THE LOWER
60S...MAINLY EAST OF THE BLUE RIDGE MOUNTAINS. WE WILL LEAVE A
CHANCE OF RAIN SHOWERS IN THE FORECAST FOR WEDNESDAY NIGHT
CONSIDERING SOME UNCERTAINTY ON THE TIMING OF COLD FRONTAL PASSAGE.
NONETHELESS...COLDER AND DRIER AIR WILL FILTER INTO THE REGION FROM
WEST TO EAST WEDNESDAY NIGHT...ALLOWING FOR TEMPERATURES TO QUICKLY FALL
THROUGH THE 50S INTO THE 40S.

THERE IS A CHANCE FOR SOME SNOW SHOWERS IN THE HIGHER ELEVATIONS OF
THE POTOMAC HIGHLANDS THURSDAY...PERHAPS ABOVE 2500 FEET. ALTHOUGH
TEMPERATURES WILL BE SOME 10 TO 15 COOLER THAN
WEDNESDAY...TEMPERATURES WILL STILL BE SLIGHTLY ABOVE NORMAL.

DRY CONDITIONS FRIDAY WITH HIGH PRESSURE BUILDING JUST TO OUR SOUTH.
HIGH TEMPERATURES MAY STILL BE SLIGHTLY ABOVE NORMAL WITH A GOOD BIT
OF SUNSHINE.

ANOTHER COLD FRONT COULD BRING A CHANCE FOR RAIN AND SNOW SHOWERS TO
THE REGION FRIDAY NIGHT INTO SATURDAY.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL REMAIN OVER THE TERMINALS THROUGH
SUNDAY...BRINGING VFR CONDITIONS. CLOUDS WILL INCREASE SUNDAY
NIGHT AND SUBVFR CONDITIONS ARE POSSIBLE TOWARD MONDAY MORNING.

CONDITIONS WILL DETERIORATE MONDAY INTO MONDAY NIGHT WITH SUB VFR
CIGS AND VSBYS. PRECIPITATION TYPE IS A BIT UNCERTAIN ALTHOUGH
EXPECTING MOSTLY LIQUID AT KDCA AND KBWI. NORTH AND WEST COULD SEE A
WINTRY MIX OF FREEZING RAIN AND SLEET FOR PART OF MONDAY. ALL RAIN
EXPECTED MONDAY NIGHT.

IFR OR LIFR CONDITIONS ARE POSSIBLE TUESDAY AND TUESDAY NIGHT
WITH LOW CLOUDS AND PERIODS OF RAIN. WINDS LIGHT AND VARIABLE. IFR
OR LIFR CONDITIONS ARE POSSIBLE AGAIN WEDNESDAY WITH NUMEROUS
GUSTY RAIN SHOWERS AHEAD OF A COLD FRONT. WINDS SOUTHEAST TO SOUTH
5 TO 10 KNOTS WEDNESDAY...INCREASING SOUTHWEST WEDNESDAY NIGHT.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS THROUGH SUNDAY NIGHT. NO
MARINE HAZARDS ARE EXPECTED DURING THIS TIME.

WINDS COULD APPROACH SCA CRITERIA LATER MONDAY INTO EARLY TUESDAY AS
LOW PRESSURE APPROACHES FROM THE SOUTH.

NO MARINE HAZARDS TUESDAY AND TUESDAY NIGHT. SMALL CRAFT ADVISORIES
MAY BE NEEDED WEDNESDAY WITH GUSTS TO 20 KNOTS.
&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BJL
NEAR TERM...BJL
SHORT TERM...BJL/KRW
LONG TERM...KLW
AVIATION...BJL/KLW/KRW
MARINE...BJL/KLW/KRW







000
FXUS61 KAKQ 201917
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
217 PM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST THROUGH TONIGHT. HIGH PRESSURE WILL BE OVER
THE AREA AGAIN DURING SUNDAY. ANOTHER LOW PRESSURE AREA MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA COAST
LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
LATEST ANALYSIS SHOWS ~1028 MB SFC HIGH PRESSURE CENTERED OVER
EASTERN VA...WITH WEAK (~1018 MB) SFC LOW PRESSURE OVER SOUTHERN
GA/NORTH FL. ISENTROPIC LIFT PER 12Z NAM AT 285K SFC SEEMS TO HAVE
A DECENT HANDLE ON THE OVERRUNNING PRECIP FOCUSING OVER CENTRAL
AND EASTERN NC AND INTO FAR SOUTHERN VA. A FEW REPORTS OF -SN WITH
VSBYS 1-3 SM OVER CENTRAL NC. NAM/RAP DEPICTION OF SFC WET BULB
TEMPERATURES OF 32-33 F LINES UP FAIRLY WELL WITH RAIN/SNOW LINE.
HAVE ADDED FLURRIES TO PORTIONS OF CENTRAL VA ALONG/WEST OF I-95
THROUGH NOON...WITH 20-30% POPS FOR RAIN/SNOW DOWN NEAR THE VA/NC
BORDER AND FOR INTERIOR NE NC. PRECIP IS VERY LIGHT SO NO
ACCUMULATION EXPECTED ANYWHERE. FORCING/LIFT WEAKENS AND FOCUSES
OVER SE NC AFTER 18Z...SO WILL LIMIT POPS AFTER 18Z TO NE NC AND
FAR SE VA FOR JUST A LOW CHC (20-30%) OF LIGHT RAIN. CLOUDY TO MOSTLY
CLOUDY TODAY WITH HIGHS IN THE UPPER 30S NW TO MID 40S SE.

SFC HIGH PRESSURE REBOUNDS TONIGHT WITH DECREASING CLOUDS. LOWS IN
THE MID 20S NORTH TO THE LOW 30S SOUTH.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. SEASONABLE HIGHS OF 45-50.

NEXT SYSTEM...THIS ONE MORE AMPLIFIED WILL AFFECT THE AREA ON
MON...WITH LIKELY TO CATEGORICAL POPS ALL ZONES MON AM/MON AFTN.
LOOKS LIKE ALL RAIN ASIDE FROM A BRIEF MIX POSSIBLE AT ONSET IN
FAR NW COUNTIES. AT THIS POINT...IT DOES NOT APPEAR ENOUGH FROZEN
PCPN WOULD OCCUR TO CAUSE ANY CONCERNS. LOWS SUNDAY NIGHT FROM
AROUND 30 NW TO AROUND 40 VA BEACH. HIGHS MON ONLY AROUND 40 NW
TO THE MID 50S FAR SE IN CAD SETUP.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
LOW PRESSURE LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING
FROM SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE
REGION TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM
THE GULF STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE
MAINTAINED. A VERY DYNAMIC SYSTEM LIFTS NNE WEST OF THE
APPALACHIANS TUESDAY NIGHT WITH THE ATTENDANT COLD FRONT CROSSING
THE MID-ATLANTIC WEDNESDAY. THE FIRST POTENTIAL OF RAIN ARRIVES
TUESDAY NIGHT ASSOCIATED WITH MOIST WAA. THE SECOND POTENTIAL WILL
BE WEDNESDAY AHEAD OF THE COLD FRONT. THERE IS A POTENTIAL FOR
THUNDER WEDNESDAY AS SURFACE DEWPOINTS POTENTIALLY EXCEED 60F
(ESPECIALLY OVER THE COASTAL PLAIN). THE PATTERN DOES SUPPORT THE
POSSIBILITY OF A DYNAMICALLY FORCED LINE OF CONVECTION CONTAINING
STRONG WIND GUSTS AS CURRENT FORECAST GUIDANCE SUGGESTS A
925-700MB WIND FIELD AVERAGING 40-50KT. THIS WOULD BE A
CLIMATOLOGICALLY RARITY THIS TIME OF YEAR...SO CONFIDENCE IS ON
THE LOW-SIDE GIVEN THAT THIS IS 5-6 DAYS OUT. TEMPERATURES WILL BE
VERY MILD AHEAD OF THE FRONT TUESDAY AND WEDNESDAY...WITH HIGHS
AVERAGING FROM THE MID 50S NW...TO MID/UPPER 60S SE. DRY AND
BREEZY CONDITIONS WILL LIKELY PREVAIL BY CHRISTMAS DAY...WITH HIGH
TEMPERATURES OF 50-55. THE FLOW BECOMES MORE SW BY FRIDAY WITH
CURRENT FORECAST HIGHS OF 55-60...BUT 60-65 IS POSSIBLE BASED ON
LOW-LEVEL THICKNESS FIELDS.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
MOSTLY VFR CONDITIONS EXPECTED ACROSS THE AREA WITH SOME -RA OR
SPRINKLES DEPICTED ON RADAR ACROSS NE NC. HIGH PRESSURE MOVES WEST
OVERNIGHT AS THE WEAK WAVE OFF THE SE US COAST CONTINUES TO PUSH
OUT TO SEA. LIGHT WINDS AND VFR CONDITIONS EXPECTED THROUGH SUN
EVENING BEFORE THE APPROACH OF THE NEXT WAVE MOVING NE FROM THE
GULF OF MEXICO AND UP THE EAST COAST.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY.

&&

.MARINE...
LATEST OBS HIGH PRESSURE SPREADS EAST ACROSS NEW ENGLAND THROUGH
TONIGHT, RIDGING SOUTH INTO THE AREA TODAY. MEANWHILE, WEAK SFC LOW
PRESSURE WILL PASS SOUTH OF THE REGION LATER TODAY AND TONIGHT. THIS
WILL MAINTAIN LIGHT NORTHERLY FLOW ~10 KT OVER THE MARINE AREA
TODAY. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY NIGHT, AS LOW
PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY NIGHT BEFORE
TRACKING NE OFF THE LOWER MID ATLANTIC COAST LATER MONDAY AND MONDAY
NIGHT. THE RESULTANT TIGHTENING SURFACE PRESSURE GRADIENT WILL ALLOW
ONSHORE (EAST) FLOW TO GRADUALLY INCREASE MONDAY AFTN, GRADUALLY
BUILDING SEAS MONDAY NIGHT AND EARLY TUESDAY. 15-20KT EASTERLY FLOW
OVER THE OCEAN AND LOWER BAY COULD PRODUCE A PERIOD OF SCA
CONDITIONS ESPECIALLY OVER THE SRN OCEAN ZONES (MAINLY FOR SEAS) AND
LOWER BAY/MOUTH OF JAMES. THERE IS NO CAA IN THE WAKE OF THIS
LOW...SO SUB-SCA CONDITIONS SHOULD PREVAIL BEHIND THE SYSTEM LATER
MONDAY NIGHT INTO TUESDAY.

A STRONG LOW PRESSURE SYSTEM LOOKS TO DEVELOP ACROSS THE OHIO
VALLEY, TRACKING WEST OF THE MOUNTAINS TUESDAY NIGHT. HOWEVER, THIS
SYSTEM WILL PUSH A STRONG COLD FRONT ACROSS THE MID ATLANTIC COAST
LATER WEDNESDAY. SCA CONDITIONS ARE LIKELY WEDNESDAY NIGHT INTO
CHRISTMAS DAY AS HIGH PRESSURE BUILDS IN FROM THE WNW.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...JDM
NEAR TERM...JDM/LKB
SHORT TERM...JDM/LKB
LONG TERM...AJZ/MAS
AVIATION...MAM/DAP
MARINE...MAM







000
FXUS61 KAKQ 201917
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
217 PM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST THROUGH TONIGHT. HIGH PRESSURE WILL BE OVER
THE AREA AGAIN DURING SUNDAY. ANOTHER LOW PRESSURE AREA MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA COAST
LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
LATEST ANALYSIS SHOWS ~1028 MB SFC HIGH PRESSURE CENTERED OVER
EASTERN VA...WITH WEAK (~1018 MB) SFC LOW PRESSURE OVER SOUTHERN
GA/NORTH FL. ISENTROPIC LIFT PER 12Z NAM AT 285K SFC SEEMS TO HAVE
A DECENT HANDLE ON THE OVERRUNNING PRECIP FOCUSING OVER CENTRAL
AND EASTERN NC AND INTO FAR SOUTHERN VA. A FEW REPORTS OF -SN WITH
VSBYS 1-3 SM OVER CENTRAL NC. NAM/RAP DEPICTION OF SFC WET BULB
TEMPERATURES OF 32-33 F LINES UP FAIRLY WELL WITH RAIN/SNOW LINE.
HAVE ADDED FLURRIES TO PORTIONS OF CENTRAL VA ALONG/WEST OF I-95
THROUGH NOON...WITH 20-30% POPS FOR RAIN/SNOW DOWN NEAR THE VA/NC
BORDER AND FOR INTERIOR NE NC. PRECIP IS VERY LIGHT SO NO
ACCUMULATION EXPECTED ANYWHERE. FORCING/LIFT WEAKENS AND FOCUSES
OVER SE NC AFTER 18Z...SO WILL LIMIT POPS AFTER 18Z TO NE NC AND
FAR SE VA FOR JUST A LOW CHC (20-30%) OF LIGHT RAIN. CLOUDY TO MOSTLY
CLOUDY TODAY WITH HIGHS IN THE UPPER 30S NW TO MID 40S SE.

SFC HIGH PRESSURE REBOUNDS TONIGHT WITH DECREASING CLOUDS. LOWS IN
THE MID 20S NORTH TO THE LOW 30S SOUTH.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. SEASONABLE HIGHS OF 45-50.

NEXT SYSTEM...THIS ONE MORE AMPLIFIED WILL AFFECT THE AREA ON
MON...WITH LIKELY TO CATEGORICAL POPS ALL ZONES MON AM/MON AFTN.
LOOKS LIKE ALL RAIN ASIDE FROM A BRIEF MIX POSSIBLE AT ONSET IN
FAR NW COUNTIES. AT THIS POINT...IT DOES NOT APPEAR ENOUGH FROZEN
PCPN WOULD OCCUR TO CAUSE ANY CONCERNS. LOWS SUNDAY NIGHT FROM
AROUND 30 NW TO AROUND 40 VA BEACH. HIGHS MON ONLY AROUND 40 NW
TO THE MID 50S FAR SE IN CAD SETUP.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
LOW PRESSURE LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING
FROM SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE
REGION TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM
THE GULF STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE
MAINTAINED. A VERY DYNAMIC SYSTEM LIFTS NNE WEST OF THE
APPALACHIANS TUESDAY NIGHT WITH THE ATTENDANT COLD FRONT CROSSING
THE MID-ATLANTIC WEDNESDAY. THE FIRST POTENTIAL OF RAIN ARRIVES
TUESDAY NIGHT ASSOCIATED WITH MOIST WAA. THE SECOND POTENTIAL WILL
BE WEDNESDAY AHEAD OF THE COLD FRONT. THERE IS A POTENTIAL FOR
THUNDER WEDNESDAY AS SURFACE DEWPOINTS POTENTIALLY EXCEED 60F
(ESPECIALLY OVER THE COASTAL PLAIN). THE PATTERN DOES SUPPORT THE
POSSIBILITY OF A DYNAMICALLY FORCED LINE OF CONVECTION CONTAINING
STRONG WIND GUSTS AS CURRENT FORECAST GUIDANCE SUGGESTS A
925-700MB WIND FIELD AVERAGING 40-50KT. THIS WOULD BE A
CLIMATOLOGICALLY RARITY THIS TIME OF YEAR...SO CONFIDENCE IS ON
THE LOW-SIDE GIVEN THAT THIS IS 5-6 DAYS OUT. TEMPERATURES WILL BE
VERY MILD AHEAD OF THE FRONT TUESDAY AND WEDNESDAY...WITH HIGHS
AVERAGING FROM THE MID 50S NW...TO MID/UPPER 60S SE. DRY AND
BREEZY CONDITIONS WILL LIKELY PREVAIL BY CHRISTMAS DAY...WITH HIGH
TEMPERATURES OF 50-55. THE FLOW BECOMES MORE SW BY FRIDAY WITH
CURRENT FORECAST HIGHS OF 55-60...BUT 60-65 IS POSSIBLE BASED ON
LOW-LEVEL THICKNESS FIELDS.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
MOSTLY VFR CONDITIONS EXPECTED ACROSS THE AREA WITH SOME -RA OR
SPRINKLES DEPICTED ON RADAR ACROSS NE NC. HIGH PRESSURE MOVES WEST
OVERNIGHT AS THE WEAK WAVE OFF THE SE US COAST CONTINUES TO PUSH
OUT TO SEA. LIGHT WINDS AND VFR CONDITIONS EXPECTED THROUGH SUN
EVENING BEFORE THE APPROACH OF THE NEXT WAVE MOVING NE FROM THE
GULF OF MEXICO AND UP THE EAST COAST.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY.

&&

.MARINE...
LATEST OBS HIGH PRESSURE SPREADS EAST ACROSS NEW ENGLAND THROUGH
TONIGHT, RIDGING SOUTH INTO THE AREA TODAY. MEANWHILE, WEAK SFC LOW
PRESSURE WILL PASS SOUTH OF THE REGION LATER TODAY AND TONIGHT. THIS
WILL MAINTAIN LIGHT NORTHERLY FLOW ~10 KT OVER THE MARINE AREA
TODAY. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY NIGHT, AS LOW
PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY NIGHT BEFORE
TRACKING NE OFF THE LOWER MID ATLANTIC COAST LATER MONDAY AND MONDAY
NIGHT. THE RESULTANT TIGHTENING SURFACE PRESSURE GRADIENT WILL ALLOW
ONSHORE (EAST) FLOW TO GRADUALLY INCREASE MONDAY AFTN, GRADUALLY
BUILDING SEAS MONDAY NIGHT AND EARLY TUESDAY. 15-20KT EASTERLY FLOW
OVER THE OCEAN AND LOWER BAY COULD PRODUCE A PERIOD OF SCA
CONDITIONS ESPECIALLY OVER THE SRN OCEAN ZONES (MAINLY FOR SEAS) AND
LOWER BAY/MOUTH OF JAMES. THERE IS NO CAA IN THE WAKE OF THIS
LOW...SO SUB-SCA CONDITIONS SHOULD PREVAIL BEHIND THE SYSTEM LATER
MONDAY NIGHT INTO TUESDAY.

A STRONG LOW PRESSURE SYSTEM LOOKS TO DEVELOP ACROSS THE OHIO
VALLEY, TRACKING WEST OF THE MOUNTAINS TUESDAY NIGHT. HOWEVER, THIS
SYSTEM WILL PUSH A STRONG COLD FRONT ACROSS THE MID ATLANTIC COAST
LATER WEDNESDAY. SCA CONDITIONS ARE LIKELY WEDNESDAY NIGHT INTO
CHRISTMAS DAY AS HIGH PRESSURE BUILDS IN FROM THE WNW.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...JDM
NEAR TERM...JDM/LKB
SHORT TERM...JDM/LKB
LONG TERM...AJZ/MAS
AVIATION...MAM/DAP
MARINE...MAM







000
FXUS61 KAKQ 201917
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
217 PM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST THROUGH TONIGHT. HIGH PRESSURE WILL BE OVER
THE AREA AGAIN DURING SUNDAY. ANOTHER LOW PRESSURE AREA MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA COAST
LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
LATEST ANALYSIS SHOWS ~1028 MB SFC HIGH PRESSURE CENTERED OVER
EASTERN VA...WITH WEAK (~1018 MB) SFC LOW PRESSURE OVER SOUTHERN
GA/NORTH FL. ISENTROPIC LIFT PER 12Z NAM AT 285K SFC SEEMS TO HAVE
A DECENT HANDLE ON THE OVERRUNNING PRECIP FOCUSING OVER CENTRAL
AND EASTERN NC AND INTO FAR SOUTHERN VA. A FEW REPORTS OF -SN WITH
VSBYS 1-3 SM OVER CENTRAL NC. NAM/RAP DEPICTION OF SFC WET BULB
TEMPERATURES OF 32-33 F LINES UP FAIRLY WELL WITH RAIN/SNOW LINE.
HAVE ADDED FLURRIES TO PORTIONS OF CENTRAL VA ALONG/WEST OF I-95
THROUGH NOON...WITH 20-30% POPS FOR RAIN/SNOW DOWN NEAR THE VA/NC
BORDER AND FOR INTERIOR NE NC. PRECIP IS VERY LIGHT SO NO
ACCUMULATION EXPECTED ANYWHERE. FORCING/LIFT WEAKENS AND FOCUSES
OVER SE NC AFTER 18Z...SO WILL LIMIT POPS AFTER 18Z TO NE NC AND
FAR SE VA FOR JUST A LOW CHC (20-30%) OF LIGHT RAIN. CLOUDY TO MOSTLY
CLOUDY TODAY WITH HIGHS IN THE UPPER 30S NW TO MID 40S SE.

SFC HIGH PRESSURE REBOUNDS TONIGHT WITH DECREASING CLOUDS. LOWS IN
THE MID 20S NORTH TO THE LOW 30S SOUTH.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. SEASONABLE HIGHS OF 45-50.

NEXT SYSTEM...THIS ONE MORE AMPLIFIED WILL AFFECT THE AREA ON
MON...WITH LIKELY TO CATEGORICAL POPS ALL ZONES MON AM/MON AFTN.
LOOKS LIKE ALL RAIN ASIDE FROM A BRIEF MIX POSSIBLE AT ONSET IN
FAR NW COUNTIES. AT THIS POINT...IT DOES NOT APPEAR ENOUGH FROZEN
PCPN WOULD OCCUR TO CAUSE ANY CONCERNS. LOWS SUNDAY NIGHT FROM
AROUND 30 NW TO AROUND 40 VA BEACH. HIGHS MON ONLY AROUND 40 NW
TO THE MID 50S FAR SE IN CAD SETUP.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
LOW PRESSURE LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING
FROM SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE
REGION TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM
THE GULF STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE
MAINTAINED. A VERY DYNAMIC SYSTEM LIFTS NNE WEST OF THE
APPALACHIANS TUESDAY NIGHT WITH THE ATTENDANT COLD FRONT CROSSING
THE MID-ATLANTIC WEDNESDAY. THE FIRST POTENTIAL OF RAIN ARRIVES
TUESDAY NIGHT ASSOCIATED WITH MOIST WAA. THE SECOND POTENTIAL WILL
BE WEDNESDAY AHEAD OF THE COLD FRONT. THERE IS A POTENTIAL FOR
THUNDER WEDNESDAY AS SURFACE DEWPOINTS POTENTIALLY EXCEED 60F
(ESPECIALLY OVER THE COASTAL PLAIN). THE PATTERN DOES SUPPORT THE
POSSIBILITY OF A DYNAMICALLY FORCED LINE OF CONVECTION CONTAINING
STRONG WIND GUSTS AS CURRENT FORECAST GUIDANCE SUGGESTS A
925-700MB WIND FIELD AVERAGING 40-50KT. THIS WOULD BE A
CLIMATOLOGICALLY RARITY THIS TIME OF YEAR...SO CONFIDENCE IS ON
THE LOW-SIDE GIVEN THAT THIS IS 5-6 DAYS OUT. TEMPERATURES WILL BE
VERY MILD AHEAD OF THE FRONT TUESDAY AND WEDNESDAY...WITH HIGHS
AVERAGING FROM THE MID 50S NW...TO MID/UPPER 60S SE. DRY AND
BREEZY CONDITIONS WILL LIKELY PREVAIL BY CHRISTMAS DAY...WITH HIGH
TEMPERATURES OF 50-55. THE FLOW BECOMES MORE SW BY FRIDAY WITH
CURRENT FORECAST HIGHS OF 55-60...BUT 60-65 IS POSSIBLE BASED ON
LOW-LEVEL THICKNESS FIELDS.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
MOSTLY VFR CONDITIONS EXPECTED ACROSS THE AREA WITH SOME -RA OR
SPRINKLES DEPICTED ON RADAR ACROSS NE NC. HIGH PRESSURE MOVES WEST
OVERNIGHT AS THE WEAK WAVE OFF THE SE US COAST CONTINUES TO PUSH
OUT TO SEA. LIGHT WINDS AND VFR CONDITIONS EXPECTED THROUGH SUN
EVENING BEFORE THE APPROACH OF THE NEXT WAVE MOVING NE FROM THE
GULF OF MEXICO AND UP THE EAST COAST.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY.

&&

.MARINE...
LATEST OBS HIGH PRESSURE SPREADS EAST ACROSS NEW ENGLAND THROUGH
TONIGHT, RIDGING SOUTH INTO THE AREA TODAY. MEANWHILE, WEAK SFC LOW
PRESSURE WILL PASS SOUTH OF THE REGION LATER TODAY AND TONIGHT. THIS
WILL MAINTAIN LIGHT NORTHERLY FLOW ~10 KT OVER THE MARINE AREA
TODAY. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY NIGHT, AS LOW
PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY NIGHT BEFORE
TRACKING NE OFF THE LOWER MID ATLANTIC COAST LATER MONDAY AND MONDAY
NIGHT. THE RESULTANT TIGHTENING SURFACE PRESSURE GRADIENT WILL ALLOW
ONSHORE (EAST) FLOW TO GRADUALLY INCREASE MONDAY AFTN, GRADUALLY
BUILDING SEAS MONDAY NIGHT AND EARLY TUESDAY. 15-20KT EASTERLY FLOW
OVER THE OCEAN AND LOWER BAY COULD PRODUCE A PERIOD OF SCA
CONDITIONS ESPECIALLY OVER THE SRN OCEAN ZONES (MAINLY FOR SEAS) AND
LOWER BAY/MOUTH OF JAMES. THERE IS NO CAA IN THE WAKE OF THIS
LOW...SO SUB-SCA CONDITIONS SHOULD PREVAIL BEHIND THE SYSTEM LATER
MONDAY NIGHT INTO TUESDAY.

A STRONG LOW PRESSURE SYSTEM LOOKS TO DEVELOP ACROSS THE OHIO
VALLEY, TRACKING WEST OF THE MOUNTAINS TUESDAY NIGHT. HOWEVER, THIS
SYSTEM WILL PUSH A STRONG COLD FRONT ACROSS THE MID ATLANTIC COAST
LATER WEDNESDAY. SCA CONDITIONS ARE LIKELY WEDNESDAY NIGHT INTO
CHRISTMAS DAY AS HIGH PRESSURE BUILDS IN FROM THE WNW.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...JDM
NEAR TERM...JDM/LKB
SHORT TERM...JDM/LKB
LONG TERM...AJZ/MAS
AVIATION...MAM/DAP
MARINE...MAM







000
FXUS61 KAKQ 201917
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
217 PM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST THROUGH TONIGHT. HIGH PRESSURE WILL BE OVER
THE AREA AGAIN DURING SUNDAY. ANOTHER LOW PRESSURE AREA MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA COAST
LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
LATEST ANALYSIS SHOWS ~1028 MB SFC HIGH PRESSURE CENTERED OVER
EASTERN VA...WITH WEAK (~1018 MB) SFC LOW PRESSURE OVER SOUTHERN
GA/NORTH FL. ISENTROPIC LIFT PER 12Z NAM AT 285K SFC SEEMS TO HAVE
A DECENT HANDLE ON THE OVERRUNNING PRECIP FOCUSING OVER CENTRAL
AND EASTERN NC AND INTO FAR SOUTHERN VA. A FEW REPORTS OF -SN WITH
VSBYS 1-3 SM OVER CENTRAL NC. NAM/RAP DEPICTION OF SFC WET BULB
TEMPERATURES OF 32-33 F LINES UP FAIRLY WELL WITH RAIN/SNOW LINE.
HAVE ADDED FLURRIES TO PORTIONS OF CENTRAL VA ALONG/WEST OF I-95
THROUGH NOON...WITH 20-30% POPS FOR RAIN/SNOW DOWN NEAR THE VA/NC
BORDER AND FOR INTERIOR NE NC. PRECIP IS VERY LIGHT SO NO
ACCUMULATION EXPECTED ANYWHERE. FORCING/LIFT WEAKENS AND FOCUSES
OVER SE NC AFTER 18Z...SO WILL LIMIT POPS AFTER 18Z TO NE NC AND
FAR SE VA FOR JUST A LOW CHC (20-30%) OF LIGHT RAIN. CLOUDY TO MOSTLY
CLOUDY TODAY WITH HIGHS IN THE UPPER 30S NW TO MID 40S SE.

SFC HIGH PRESSURE REBOUNDS TONIGHT WITH DECREASING CLOUDS. LOWS IN
THE MID 20S NORTH TO THE LOW 30S SOUTH.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. SEASONABLE HIGHS OF 45-50.

NEXT SYSTEM...THIS ONE MORE AMPLIFIED WILL AFFECT THE AREA ON
MON...WITH LIKELY TO CATEGORICAL POPS ALL ZONES MON AM/MON AFTN.
LOOKS LIKE ALL RAIN ASIDE FROM A BRIEF MIX POSSIBLE AT ONSET IN
FAR NW COUNTIES. AT THIS POINT...IT DOES NOT APPEAR ENOUGH FROZEN
PCPN WOULD OCCUR TO CAUSE ANY CONCERNS. LOWS SUNDAY NIGHT FROM
AROUND 30 NW TO AROUND 40 VA BEACH. HIGHS MON ONLY AROUND 40 NW
TO THE MID 50S FAR SE IN CAD SETUP.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
LOW PRESSURE LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING
FROM SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE
REGION TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM
THE GULF STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE
MAINTAINED. A VERY DYNAMIC SYSTEM LIFTS NNE WEST OF THE
APPALACHIANS TUESDAY NIGHT WITH THE ATTENDANT COLD FRONT CROSSING
THE MID-ATLANTIC WEDNESDAY. THE FIRST POTENTIAL OF RAIN ARRIVES
TUESDAY NIGHT ASSOCIATED WITH MOIST WAA. THE SECOND POTENTIAL WILL
BE WEDNESDAY AHEAD OF THE COLD FRONT. THERE IS A POTENTIAL FOR
THUNDER WEDNESDAY AS SURFACE DEWPOINTS POTENTIALLY EXCEED 60F
(ESPECIALLY OVER THE COASTAL PLAIN). THE PATTERN DOES SUPPORT THE
POSSIBILITY OF A DYNAMICALLY FORCED LINE OF CONVECTION CONTAINING
STRONG WIND GUSTS AS CURRENT FORECAST GUIDANCE SUGGESTS A
925-700MB WIND FIELD AVERAGING 40-50KT. THIS WOULD BE A
CLIMATOLOGICALLY RARITY THIS TIME OF YEAR...SO CONFIDENCE IS ON
THE LOW-SIDE GIVEN THAT THIS IS 5-6 DAYS OUT. TEMPERATURES WILL BE
VERY MILD AHEAD OF THE FRONT TUESDAY AND WEDNESDAY...WITH HIGHS
AVERAGING FROM THE MID 50S NW...TO MID/UPPER 60S SE. DRY AND
BREEZY CONDITIONS WILL LIKELY PREVAIL BY CHRISTMAS DAY...WITH HIGH
TEMPERATURES OF 50-55. THE FLOW BECOMES MORE SW BY FRIDAY WITH
CURRENT FORECAST HIGHS OF 55-60...BUT 60-65 IS POSSIBLE BASED ON
LOW-LEVEL THICKNESS FIELDS.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
MOSTLY VFR CONDITIONS EXPECTED ACROSS THE AREA WITH SOME -RA OR
SPRINKLES DEPICTED ON RADAR ACROSS NE NC. HIGH PRESSURE MOVES WEST
OVERNIGHT AS THE WEAK WAVE OFF THE SE US COAST CONTINUES TO PUSH
OUT TO SEA. LIGHT WINDS AND VFR CONDITIONS EXPECTED THROUGH SUN
EVENING BEFORE THE APPROACH OF THE NEXT WAVE MOVING NE FROM THE
GULF OF MEXICO AND UP THE EAST COAST.

OUTLOOK...A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL
BOUNDARIES WILL BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS
AND VISIBILITIES MONDAY THROUGH WEDNESDAY.

&&

.MARINE...
LATEST OBS HIGH PRESSURE SPREADS EAST ACROSS NEW ENGLAND THROUGH
TONIGHT, RIDGING SOUTH INTO THE AREA TODAY. MEANWHILE, WEAK SFC LOW
PRESSURE WILL PASS SOUTH OF THE REGION LATER TODAY AND TONIGHT. THIS
WILL MAINTAIN LIGHT NORTHERLY FLOW ~10 KT OVER THE MARINE AREA
TODAY. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY NIGHT, AS LOW
PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY NIGHT BEFORE
TRACKING NE OFF THE LOWER MID ATLANTIC COAST LATER MONDAY AND MONDAY
NIGHT. THE RESULTANT TIGHTENING SURFACE PRESSURE GRADIENT WILL ALLOW
ONSHORE (EAST) FLOW TO GRADUALLY INCREASE MONDAY AFTN, GRADUALLY
BUILDING SEAS MONDAY NIGHT AND EARLY TUESDAY. 15-20KT EASTERLY FLOW
OVER THE OCEAN AND LOWER BAY COULD PRODUCE A PERIOD OF SCA
CONDITIONS ESPECIALLY OVER THE SRN OCEAN ZONES (MAINLY FOR SEAS) AND
LOWER BAY/MOUTH OF JAMES. THERE IS NO CAA IN THE WAKE OF THIS
LOW...SO SUB-SCA CONDITIONS SHOULD PREVAIL BEHIND THE SYSTEM LATER
MONDAY NIGHT INTO TUESDAY.

A STRONG LOW PRESSURE SYSTEM LOOKS TO DEVELOP ACROSS THE OHIO
VALLEY, TRACKING WEST OF THE MOUNTAINS TUESDAY NIGHT. HOWEVER, THIS
SYSTEM WILL PUSH A STRONG COLD FRONT ACROSS THE MID ATLANTIC COAST
LATER WEDNESDAY. SCA CONDITIONS ARE LIKELY WEDNESDAY NIGHT INTO
CHRISTMAS DAY AS HIGH PRESSURE BUILDS IN FROM THE WNW.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...JDM
NEAR TERM...JDM/LKB
SHORT TERM...JDM/LKB
LONG TERM...AJZ/MAS
AVIATION...MAM/DAP
MARINE...MAM







000
FXUS61 KPBZ 201912
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
212 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE IN CONTROL INTO MONDAY. INCREASING PRECIPITATION
CHANCES TUESDAY. STORM SYSTEM BRINGS RAIN AND WIND CHRISTMAS
EVE...AND SNOW SHOWERS CHRISTMAS DAY.

&&

.NEAR TERM /THROUGH SUNDAY/...
WEAKER INVERSION ACROSS PORTIONS OF SOUTHERN PA HAS ALLOWED LOWER
CLOUDS TO BREAK UP SOMEWHAT...ALTHOUGH THEY ARE HANGING TOUGH SO FAR
ACROSS THE NORTHERN COUNTIES NEAR FKL/DUJ AS WELL AS IN SOUTHEAST
OHIO.  EXPECT THESE TO REFORM TONIGHT AS INVERSION SHARPENS UP AGAIN
IN VERY WEAK FLOW...THUS GOING MOSTLY CLOUDY MOST AREAS.  GOING TO HANG
ON TO SLIGHT CHANCE POPS IN THE SOUTHEAST WITH SHORTWAVE TROUGH
MOVING ACROSS AND SLIGHTLY BETTER MOISTURE PROFILE...BUT SNOW
ACCUMULATION IS NOT EXPECTED.  THIS POSSIBILITY ENDS BY 09Z. ONLY
MINOR MODIFICATION TO GENERALLY SEASONABLE TEMPERATURES.

INVERSION IS MAINTAINED SUNDAY MORNING...BUT BY AFTERNOON EXPECT
STRATUS TO MIX OUT INTO A CU FIELD AND THEN SCATTER OUT BY EVENING.
A BIT MORE SUN SHOULD ALLOW FOR AFTERNOON HIGH TEMPS AROUND 5
DEGREES WARMER THAN TODAY. CL

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
BENIGN WEATHER INITIALLY WITH HIGH PRESSURE TO OUR EAST AND IN
CONTROL.  SOUTHEAST WINDS IN RESPONSE TO SURFACE ANTICYCLONE
POSITION WILL FACILITATE DEVELOPMENT OF STRATUS OVER EASTERN
PORTIONS OF TUCKER AND GARRETT COUNTIES MONDAY INTO MONDAY NIGHT.
PCPN ONSET HAS SLOWED DOWN FROM PREVIOUS CYCLES...BUT THERE REMAINS
A VERY LOW PROBABILITY OF FREEZING RAIN AND/OR SLEET OVER
AFOREMENTIONED AREAS MONDAY.  FOR NOW...TRENDED FORECAST WITH PCPN
COMMENCING DURING THE AFTERNOON WHICH REFLECT LATEST NUMERICAL
MODELS.  WITH THIS SCENARIO...LOW LEVEL SUB-FREEZING AIR SHOULD
SCOUR OUT YIELDING AN ALL RAIN PTYPE.

RAIN SHADOW EFFECT TAKES PLACES TUESDAY WITH SOUTHEAST WINDS
WIDESPREAD OVER THE REGION. AN ISOLATED SHOWER REACHING EASTERN OHIO
AND FAR NWRN PA IS NOT OUT OF THE QUESTION...SO KEPT A SLIGHT
CHANCE.  WOULD NOT BE SURPRISED TO SEE BREAKS IN THE CLOUDS WHICH
COULD ALLOW FOR A FEW LOCATIONS TO EXCEED 60 DEGREES.  RECORD HIGHS
FOR PITTSBURGH...MORGANTOWN...AND ZANESVILLE ALL RESIDE WELL INTO
THE UPPER 60S...SO AT THIS JUNCTURE RECORD WARMTH IS NOT FORESEEN.
PRECIP ASSOCIATED WITH THE SURFACE LOW PRESSURE SYSTEM EJECTING FROM
THE GULF COAST REGION REACHES SERN AREAS OF THE FORECAST AREA THAT
EVENING.

A BLEND OF THE ONGOING FORECAST AND BIAS CORRECTED ECMWF WERE USED
FOR TEMPERATURES.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
HIGHLIGHTS:
- A WET CHRISTMAS EVE
- TEMPERATURES RETURN BACK TO NORMAL VALUES CHRISTMAS DAY
- SLIGHTLY ABOVE NORMAL TEMPERATURES RETURN BY FRIDAY

STRONG LOW PRESSURE SYSTEM THAT HAS BEEN MUCH ADVERTISED GIVEN THE
TIME PERIOD WHICH IT AFFECTS OUR AREA IS STILL ON TRACK.  LONG RANGE
ENSEMBLE PREDICTION SYSTEMS AND OPERATIONAL MODELS ARE CONVERGING ON
A TRACK THROUGH IND / ILL THEN NORTH INTO CANADA.  THIS WILL MAKE
FOR ALL LIQUID PRECIPITATION ON THE FRONT END.  TEMPERATURES WILL
SOAR TO NEARLY 20 DEGREES ABOVE NORMAL WEDNESDAY WITH 50S COMMON.
COUPLED WITH INFLUX OF MOISTURE FROM THE GULF OF MEXICO...SOUNDINGS
ILLUSTRATE ELEVATED INSTABILITY WHICH PUSHES TEMP DIFFERENTIAL
BETWEEN H8 AND H5 TO NEARLY 0C.  THIS COULD LEAD TO ISOLATED
THUNDERSTORMS AHEAD OF THE BAROCLINIC ZONE.  FOR THE TIME
BEING...OPTED TO LEAVE THUNDER OUT OF THE FORECAST AND WAIT FOR
BETTER CONTINUITY GIVEN THIS STILL IS FIVE DAYS OUT.  DESPITE PWATS
NEARLY TWO STANDARD DEVIATIONS ABOVE NORMAL...COMBINATION OF
KATABATIC WINDS AND DRY CONVEYOR BELT WILL LIMIT QPF POTENTIAL TO
NEGATE ANY FLOOD THREAT.  LONG RANGE HYDROLOGIC MODELS SHOW VERY
LITTLE RISE IN AREA RIVERS...WHICH CORRELATES WELL TO THE PROJECTED
QPF OF 0.50 TO 1.00".

WITH THE TRACK OF THE CYCLONE DUE N...COLD AIR INJECTED INTO THE
AREA WILL BE OF MIDWEST ORIGIN...SO TEMPS WILL RETREAT BACK TO
SEASONAL BENCHMARKS CHRISTMAS DAY.  FOR THOSE WHO ARE LOOKING FOR
SNOW ON CHRISTMAS...A CHANCE OF SNOW SHOWERS EXIST...BUT GIVEN
TRAJECTORY FROM THE SOUTHWEST ANY ACCUMULATION ASSOCIATED WITH THE
UPPER LEVEL SYSTEM WILL BE LIGHT AT BEST.  HISTORICALLY...THERE IS
ONLY A 17 PERCENT CHANCE OF AT LEAST ONE INCH OF SNOW ON THE GROUND
AT PITTSBURGH CHRISTMAS MORNING.

H8 WINDS PUSH 50KTS WEDNESDAY NIGHT INTO THURSDAY AND HIGHEST
ANOMALIES RESIDE ALONG THE LAKE SHORE...SO EXPECT HIGHEST GUSTS
WOULD DO SO AS WELL.  NONETHELESS...PERIOD FROM WEDNESDAY NIGHT INTO
THURSDAY STRONG ISALLOBARIC FLOW COULD YIELD GUSTS IN EXCESS OF 40
MPH ESPECIALLY IN THE MOUNTAINS OF WRN MD AND NRN WV.

BALANCE OF THE EXTENDED IS CHARACTERIZED BY UNCERTAINTY AS ONE WOULD
EXPECT IN THE DAY 6 -7 TIME FRAME.  ECMWF HAS A STRONGER SYSTEM
CROSSING FRIDAY NIGHT VERSUS GFS WHICH IS MUCH WEAKER.  EITHER CASE
PTYPE SHOULD BE RAIN WITH SNOW SHOWERS ON THE BACKSIDE.  NO PLUNGES
OF ARCTIC AIR ARE FORECAST IN THE NEXT 10 DAYS.  MAX/MIN
TEMPERATURES WERE A BLEND OF THE FORECAST AND ECMWF BIAS CORRECTED
DATA SET.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
CLOUDS HAVE MANAGED TO THIN SOMEWHAT ACROSS SOUTHERN PA/NORTHERN
WV AND EXPECT THIS TO PERSIST FOR A FEW HOURS. HOWEVER...SW FLOW
WILL BRING A BIT MORE MOISTURE ALOFT...AS WELL AS WARM
ADVECTION...WHICH WILL HELP TO SHARPEN UP THE INVERSION ALOFT.
THUS...EXPECTING MOST AREAS TO SEE MVFR CIGS BECOME REESTABLISHED
BY THE LATE EVENING HOURS...AND PERSIST THROUGH THE REST OF THE
TAF PERIOD. CANNOT RULE OUT A FEW SNOWFLAKES TONIGHT IN LOCATIONS
LIKE MGW AND LBE...BUT THIS IS NOT EXPECTED TO CREATE ANY
RESTRICTIONS. ZZV COULD SEE SOME BREAKUP PAST 15Z THOUGH. WINDS
WILL REMAIN CALM OR VERY LIGHT.


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$






000
FXUS61 KPBZ 201733
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1233 PM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
SHORTWAVE TROUGH WILL SWING THROUGH THE OHIO VALLEY AND ACROSS THE
CWA DURING THE EARLY PART OF THE NIGHT. EXPECTING CLOUD COVER TO
BE MAINTAINED THROUGH THE PERIOD WITH AN OVERALL THIN BUT
PERSISTENT MOISTURE LAYER A COUPLE THOUSAND FEET UP.  WHILE
MOISTURE IS OTHERWISE FAIRLY MEAGER AT PRESENT...SW FLOW AT H850
WILL HELP PUSH MARGINALLY BETTER PWAT VALUES INTO THE SOUTHERN
COUNTIES BY SUNSET. THIS COMBINED WITH MODEST SUPPORT FROM SHORTWAVE MAY
ALLOW A FEW SNOWFLAKES TO SQUEEZE OUT...SO ADDED A SLIGHT CHANCE
POP TO THE GRIDS...MAINLY FOR THE EVENING...GENERALLY SOUTH OF A
HLG/PIT/IDI LINE. ANY ACTIVITY SHOULD END SOON AFTER 06Z WITH
SHORTWAVE DEPARTURE. TEMPERATURE FORECAST LOOKS DECENT OVERALL AT
THIS TIME.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
MODELS ARE SHOWING SOME IMPROVEMENT SUNDAY...PARTICULARLY OVER
THE WEST AND FAR SOUTH. HOWEVER...MODEL SOUNDINGS FOR THE REST OF
THE REGION STILL WANT TO MAINTAIN A SATURATED LAYER AROUND 2500FT
FOR MOST OF THE DAY...WHICH DOES NOT PRESENT MUCH HOPE FOR
SUNSHINE. CLOUDS WILL BE TRICKY ON SUNDAY...TRYING TO DETERMINE
HOW MUCH OF THE CLOUD DECK WILL BE ERODED.

SPLIT FLOW DEVELOPS ON MONDAY WITH A LARGE SYSTEM TO THE WEST AND
ANOTHER SYSTEM TO THE SOUTH-SOUTHEAST. IT APPEARS THAT THE AREA
WILL LIE IN BETWEEN LIMITING THE CHANCES FOR PRECIPITATION. WAA
WILL CONTINUE ON MONDAY AND LOW-LEVEL MOISTURE INCREASES ONCE
AGAIN. LOOKS LIKE A GOOD DEAL OF CLOUD COVER AGAIN MONDAY. A WEAK
AND UNORGANIZED SHORTWAVE TROUGH WILL SWING THROUGH MONDAY...
ALLOWING FOR THE POSSIBILITY OF SOME LIGHT PRECIP...MAINLY OVER
THE SOUTHERN RIDGES. THIS WILL NEED TO BE FINE TUNED AS THE WARMER
AIR ALOFT MAY OCCUR BEFORE SURFACE TEMPS RESPOND. CONFIDENCE IS
LOW THAT ANY PRECIP WILL OCCUR...SO FOR FORECAST WILL LEAVE OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
STILL SEEING SOME MINOR DIFFERENCES IN MEDIUM RANGE MODEL
SOLUTIONS FOR MIDWEEK SYSTEM. THINK MUCH OF TUESDAY COULD BE DRY
OR JUST LIGHT SHOWERS AS AREA WILL BE WELL INTO THE WARM SECTOR. RAIN
WILL OVERSPREAD THE AREA TUESDAY NIGHT AHEAD OF OCCLUDED FRONT AND
CONTINUE THROUGH WEDNESDAY. COLDER AIR WILL MOVE IN LATER
WEDNESDAY NIGHT CHANGING ANY LINGERING SHOWERS TO SNOW SHOWERS.
COULD SEE A BRIEF UPTICK IN SNOW SHOWER COVERAGE EARLY THURSDAY
MORNING AS MAIN TROUGH SWINGS THROUGH. COLD AIR WILL BE IN PLACE
THURSDAY...BUT WIND DIRECTION NOT OPTIMAL FOR LAKE INFLUENCED SNOW
SHOWERS.

WARMER AIR WILL MOVE BACK IN THURSDAY NIGHT AND FRIDAY.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CLOUDS HAVE MANAGED TO THIN SOMEWHAT ACROSS SOUTHERN PA/NORTHERN
WV AND EXPECT THIS TO PERSIST FOR A FEW HOURS. HOWEVER...SW FLOW
WILL BRING A BIT MORE MOISTURE ALOFT...AS WELL AS WARM
ADVECTION...WHICH WILL HELP TO SHARPEN UP THE INVERSION ALOFT.
THUS...EXPECTING MOST AREAS TO SEE MVFR CIGS BECOME REESTABLISHED
BY THE LATE EVENING HOURS...AND PERSIST THROUGH THE REST OF THE
TAF PERIOD. CANNOT RULE OUT A FEW SNOWFLAKES TONIGHT IN LOCATIONS
LIKE MGW AND LBE...BUT THIS IS NOT EXPECTED TO CREATE ANY
RESTRICTIONS. ZZV COULD SEE SOME BREAKUP PAST 15Z THOUGH. WINDS
WILL REMAIN CALM OR VERY LIGHT.


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$






000
FXUS61 KPBZ 201733
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1233 PM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
SHORTWAVE TROUGH WILL SWING THROUGH THE OHIO VALLEY AND ACROSS THE
CWA DURING THE EARLY PART OF THE NIGHT. EXPECTING CLOUD COVER TO
BE MAINTAINED THROUGH THE PERIOD WITH AN OVERALL THIN BUT
PERSISTENT MOISTURE LAYER A COUPLE THOUSAND FEET UP.  WHILE
MOISTURE IS OTHERWISE FAIRLY MEAGER AT PRESENT...SW FLOW AT H850
WILL HELP PUSH MARGINALLY BETTER PWAT VALUES INTO THE SOUTHERN
COUNTIES BY SUNSET. THIS COMBINED WITH MODEST SUPPORT FROM SHORTWAVE MAY
ALLOW A FEW SNOWFLAKES TO SQUEEZE OUT...SO ADDED A SLIGHT CHANCE
POP TO THE GRIDS...MAINLY FOR THE EVENING...GENERALLY SOUTH OF A
HLG/PIT/IDI LINE. ANY ACTIVITY SHOULD END SOON AFTER 06Z WITH
SHORTWAVE DEPARTURE. TEMPERATURE FORECAST LOOKS DECENT OVERALL AT
THIS TIME.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
MODELS ARE SHOWING SOME IMPROVEMENT SUNDAY...PARTICULARLY OVER
THE WEST AND FAR SOUTH. HOWEVER...MODEL SOUNDINGS FOR THE REST OF
THE REGION STILL WANT TO MAINTAIN A SATURATED LAYER AROUND 2500FT
FOR MOST OF THE DAY...WHICH DOES NOT PRESENT MUCH HOPE FOR
SUNSHINE. CLOUDS WILL BE TRICKY ON SUNDAY...TRYING TO DETERMINE
HOW MUCH OF THE CLOUD DECK WILL BE ERODED.

SPLIT FLOW DEVELOPS ON MONDAY WITH A LARGE SYSTEM TO THE WEST AND
ANOTHER SYSTEM TO THE SOUTH-SOUTHEAST. IT APPEARS THAT THE AREA
WILL LIE IN BETWEEN LIMITING THE CHANCES FOR PRECIPITATION. WAA
WILL CONTINUE ON MONDAY AND LOW-LEVEL MOISTURE INCREASES ONCE
AGAIN. LOOKS LIKE A GOOD DEAL OF CLOUD COVER AGAIN MONDAY. A WEAK
AND UNORGANIZED SHORTWAVE TROUGH WILL SWING THROUGH MONDAY...
ALLOWING FOR THE POSSIBILITY OF SOME LIGHT PRECIP...MAINLY OVER
THE SOUTHERN RIDGES. THIS WILL NEED TO BE FINE TUNED AS THE WARMER
AIR ALOFT MAY OCCUR BEFORE SURFACE TEMPS RESPOND. CONFIDENCE IS
LOW THAT ANY PRECIP WILL OCCUR...SO FOR FORECAST WILL LEAVE OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
STILL SEEING SOME MINOR DIFFERENCES IN MEDIUM RANGE MODEL
SOLUTIONS FOR MIDWEEK SYSTEM. THINK MUCH OF TUESDAY COULD BE DRY
OR JUST LIGHT SHOWERS AS AREA WILL BE WELL INTO THE WARM SECTOR. RAIN
WILL OVERSPREAD THE AREA TUESDAY NIGHT AHEAD OF OCCLUDED FRONT AND
CONTINUE THROUGH WEDNESDAY. COLDER AIR WILL MOVE IN LATER
WEDNESDAY NIGHT CHANGING ANY LINGERING SHOWERS TO SNOW SHOWERS.
COULD SEE A BRIEF UPTICK IN SNOW SHOWER COVERAGE EARLY THURSDAY
MORNING AS MAIN TROUGH SWINGS THROUGH. COLD AIR WILL BE IN PLACE
THURSDAY...BUT WIND DIRECTION NOT OPTIMAL FOR LAKE INFLUENCED SNOW
SHOWERS.

WARMER AIR WILL MOVE BACK IN THURSDAY NIGHT AND FRIDAY.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CLOUDS HAVE MANAGED TO THIN SOMEWHAT ACROSS SOUTHERN PA/NORTHERN
WV AND EXPECT THIS TO PERSIST FOR A FEW HOURS. HOWEVER...SW FLOW
WILL BRING A BIT MORE MOISTURE ALOFT...AS WELL AS WARM
ADVECTION...WHICH WILL HELP TO SHARPEN UP THE INVERSION ALOFT.
THUS...EXPECTING MOST AREAS TO SEE MVFR CIGS BECOME REESTABLISHED
BY THE LATE EVENING HOURS...AND PERSIST THROUGH THE REST OF THE
TAF PERIOD. CANNOT RULE OUT A FEW SNOWFLAKES TONIGHT IN LOCATIONS
LIKE MGW AND LBE...BUT THIS IS NOT EXPECTED TO CREATE ANY
RESTRICTIONS. ZZV COULD SEE SOME BREAKUP PAST 15Z THOUGH. WINDS
WILL REMAIN CALM OR VERY LIGHT.


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$






000
FXUS61 KPBZ 201733
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1233 PM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
SHORTWAVE TROUGH WILL SWING THROUGH THE OHIO VALLEY AND ACROSS THE
CWA DURING THE EARLY PART OF THE NIGHT. EXPECTING CLOUD COVER TO
BE MAINTAINED THROUGH THE PERIOD WITH AN OVERALL THIN BUT
PERSISTENT MOISTURE LAYER A COUPLE THOUSAND FEET UP.  WHILE
MOISTURE IS OTHERWISE FAIRLY MEAGER AT PRESENT...SW FLOW AT H850
WILL HELP PUSH MARGINALLY BETTER PWAT VALUES INTO THE SOUTHERN
COUNTIES BY SUNSET. THIS COMBINED WITH MODEST SUPPORT FROM SHORTWAVE MAY
ALLOW A FEW SNOWFLAKES TO SQUEEZE OUT...SO ADDED A SLIGHT CHANCE
POP TO THE GRIDS...MAINLY FOR THE EVENING...GENERALLY SOUTH OF A
HLG/PIT/IDI LINE. ANY ACTIVITY SHOULD END SOON AFTER 06Z WITH
SHORTWAVE DEPARTURE. TEMPERATURE FORECAST LOOKS DECENT OVERALL AT
THIS TIME.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
MODELS ARE SHOWING SOME IMPROVEMENT SUNDAY...PARTICULARLY OVER
THE WEST AND FAR SOUTH. HOWEVER...MODEL SOUNDINGS FOR THE REST OF
THE REGION STILL WANT TO MAINTAIN A SATURATED LAYER AROUND 2500FT
FOR MOST OF THE DAY...WHICH DOES NOT PRESENT MUCH HOPE FOR
SUNSHINE. CLOUDS WILL BE TRICKY ON SUNDAY...TRYING TO DETERMINE
HOW MUCH OF THE CLOUD DECK WILL BE ERODED.

SPLIT FLOW DEVELOPS ON MONDAY WITH A LARGE SYSTEM TO THE WEST AND
ANOTHER SYSTEM TO THE SOUTH-SOUTHEAST. IT APPEARS THAT THE AREA
WILL LIE IN BETWEEN LIMITING THE CHANCES FOR PRECIPITATION. WAA
WILL CONTINUE ON MONDAY AND LOW-LEVEL MOISTURE INCREASES ONCE
AGAIN. LOOKS LIKE A GOOD DEAL OF CLOUD COVER AGAIN MONDAY. A WEAK
AND UNORGANIZED SHORTWAVE TROUGH WILL SWING THROUGH MONDAY...
ALLOWING FOR THE POSSIBILITY OF SOME LIGHT PRECIP...MAINLY OVER
THE SOUTHERN RIDGES. THIS WILL NEED TO BE FINE TUNED AS THE WARMER
AIR ALOFT MAY OCCUR BEFORE SURFACE TEMPS RESPOND. CONFIDENCE IS
LOW THAT ANY PRECIP WILL OCCUR...SO FOR FORECAST WILL LEAVE OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
STILL SEEING SOME MINOR DIFFERENCES IN MEDIUM RANGE MODEL
SOLUTIONS FOR MIDWEEK SYSTEM. THINK MUCH OF TUESDAY COULD BE DRY
OR JUST LIGHT SHOWERS AS AREA WILL BE WELL INTO THE WARM SECTOR. RAIN
WILL OVERSPREAD THE AREA TUESDAY NIGHT AHEAD OF OCCLUDED FRONT AND
CONTINUE THROUGH WEDNESDAY. COLDER AIR WILL MOVE IN LATER
WEDNESDAY NIGHT CHANGING ANY LINGERING SHOWERS TO SNOW SHOWERS.
COULD SEE A BRIEF UPTICK IN SNOW SHOWER COVERAGE EARLY THURSDAY
MORNING AS MAIN TROUGH SWINGS THROUGH. COLD AIR WILL BE IN PLACE
THURSDAY...BUT WIND DIRECTION NOT OPTIMAL FOR LAKE INFLUENCED SNOW
SHOWERS.

WARMER AIR WILL MOVE BACK IN THURSDAY NIGHT AND FRIDAY.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CLOUDS HAVE MANAGED TO THIN SOMEWHAT ACROSS SOUTHERN PA/NORTHERN
WV AND EXPECT THIS TO PERSIST FOR A FEW HOURS. HOWEVER...SW FLOW
WILL BRING A BIT MORE MOISTURE ALOFT...AS WELL AS WARM
ADVECTION...WHICH WILL HELP TO SHARPEN UP THE INVERSION ALOFT.
THUS...EXPECTING MOST AREAS TO SEE MVFR CIGS BECOME REESTABLISHED
BY THE LATE EVENING HOURS...AND PERSIST THROUGH THE REST OF THE
TAF PERIOD. CANNOT RULE OUT A FEW SNOWFLAKES TONIGHT IN LOCATIONS
LIKE MGW AND LBE...BUT THIS IS NOT EXPECTED TO CREATE ANY
RESTRICTIONS. ZZV COULD SEE SOME BREAKUP PAST 15Z THOUGH. WINDS
WILL REMAIN CALM OR VERY LIGHT.


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$






000
FXUS61 KPBZ 201733
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1233 PM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
SHORTWAVE TROUGH WILL SWING THROUGH THE OHIO VALLEY AND ACROSS THE
CWA DURING THE EARLY PART OF THE NIGHT. EXPECTING CLOUD COVER TO
BE MAINTAINED THROUGH THE PERIOD WITH AN OVERALL THIN BUT
PERSISTENT MOISTURE LAYER A COUPLE THOUSAND FEET UP.  WHILE
MOISTURE IS OTHERWISE FAIRLY MEAGER AT PRESENT...SW FLOW AT H850
WILL HELP PUSH MARGINALLY BETTER PWAT VALUES INTO THE SOUTHERN
COUNTIES BY SUNSET. THIS COMBINED WITH MODEST SUPPORT FROM SHORTWAVE MAY
ALLOW A FEW SNOWFLAKES TO SQUEEZE OUT...SO ADDED A SLIGHT CHANCE
POP TO THE GRIDS...MAINLY FOR THE EVENING...GENERALLY SOUTH OF A
HLG/PIT/IDI LINE. ANY ACTIVITY SHOULD END SOON AFTER 06Z WITH
SHORTWAVE DEPARTURE. TEMPERATURE FORECAST LOOKS DECENT OVERALL AT
THIS TIME.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
MODELS ARE SHOWING SOME IMPROVEMENT SUNDAY...PARTICULARLY OVER
THE WEST AND FAR SOUTH. HOWEVER...MODEL SOUNDINGS FOR THE REST OF
THE REGION STILL WANT TO MAINTAIN A SATURATED LAYER AROUND 2500FT
FOR MOST OF THE DAY...WHICH DOES NOT PRESENT MUCH HOPE FOR
SUNSHINE. CLOUDS WILL BE TRICKY ON SUNDAY...TRYING TO DETERMINE
HOW MUCH OF THE CLOUD DECK WILL BE ERODED.

SPLIT FLOW DEVELOPS ON MONDAY WITH A LARGE SYSTEM TO THE WEST AND
ANOTHER SYSTEM TO THE SOUTH-SOUTHEAST. IT APPEARS THAT THE AREA
WILL LIE IN BETWEEN LIMITING THE CHANCES FOR PRECIPITATION. WAA
WILL CONTINUE ON MONDAY AND LOW-LEVEL MOISTURE INCREASES ONCE
AGAIN. LOOKS LIKE A GOOD DEAL OF CLOUD COVER AGAIN MONDAY. A WEAK
AND UNORGANIZED SHORTWAVE TROUGH WILL SWING THROUGH MONDAY...
ALLOWING FOR THE POSSIBILITY OF SOME LIGHT PRECIP...MAINLY OVER
THE SOUTHERN RIDGES. THIS WILL NEED TO BE FINE TUNED AS THE WARMER
AIR ALOFT MAY OCCUR BEFORE SURFACE TEMPS RESPOND. CONFIDENCE IS
LOW THAT ANY PRECIP WILL OCCUR...SO FOR FORECAST WILL LEAVE OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
STILL SEEING SOME MINOR DIFFERENCES IN MEDIUM RANGE MODEL
SOLUTIONS FOR MIDWEEK SYSTEM. THINK MUCH OF TUESDAY COULD BE DRY
OR JUST LIGHT SHOWERS AS AREA WILL BE WELL INTO THE WARM SECTOR. RAIN
WILL OVERSPREAD THE AREA TUESDAY NIGHT AHEAD OF OCCLUDED FRONT AND
CONTINUE THROUGH WEDNESDAY. COLDER AIR WILL MOVE IN LATER
WEDNESDAY NIGHT CHANGING ANY LINGERING SHOWERS TO SNOW SHOWERS.
COULD SEE A BRIEF UPTICK IN SNOW SHOWER COVERAGE EARLY THURSDAY
MORNING AS MAIN TROUGH SWINGS THROUGH. COLD AIR WILL BE IN PLACE
THURSDAY...BUT WIND DIRECTION NOT OPTIMAL FOR LAKE INFLUENCED SNOW
SHOWERS.

WARMER AIR WILL MOVE BACK IN THURSDAY NIGHT AND FRIDAY.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CLOUDS HAVE MANAGED TO THIN SOMEWHAT ACROSS SOUTHERN PA/NORTHERN
WV AND EXPECT THIS TO PERSIST FOR A FEW HOURS. HOWEVER...SW FLOW
WILL BRING A BIT MORE MOISTURE ALOFT...AS WELL AS WARM
ADVECTION...WHICH WILL HELP TO SHARPEN UP THE INVERSION ALOFT.
THUS...EXPECTING MOST AREAS TO SEE MVFR CIGS BECOME REESTABLISHED
BY THE LATE EVENING HOURS...AND PERSIST THROUGH THE REST OF THE
TAF PERIOD. CANNOT RULE OUT A FEW SNOWFLAKES TONIGHT IN LOCATIONS
LIKE MGW AND LBE...BUT THIS IS NOT EXPECTED TO CREATE ANY
RESTRICTIONS. ZZV COULD SEE SOME BREAKUP PAST 15Z THOUGH. WINDS
WILL REMAIN CALM OR VERY LIGHT.


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
NEXT STORM SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND
RESULT IN WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF
LLWS INTO THURSDAY.

&&

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

&&

$$






000
FXUS61 KPHI 201548
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1048 AM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER SOUTHWESTERN QUEBEC THIS MORNING WILL
DRIFT EASTWARD AND IT SHOULD REACH ATLANTIC CANADA ON MONDAY. WEAK
LOW PRESSURE IS FORECAST TO DEVELOP OFF THE CAROLINA COAST ON
MONDAY BEFORE MOVING SLOWLY NORTHEASTWARD AND DISSIPATING. STRONG
LOW PRESSURE IS EXPECTED TO LIFT NORTHWARD FROM THE LOWER
MISSISSIPPI RIVER VALLEY AND ACROSS THE GREAT LAKES DURING THE MID
WEEK PERIOD. THE LOW IS ANTICIPATED TO PULL A WARM FRONT THROUGH
OUR REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT ON WEDNESDAY
NIGHT. HIGH PRESSURE IS EXPECTED TO FOLLOW FROM THE SOUTHWEST FOR
THURSDAY AND FRIDAY. ANOTHER COLD FRONT IS FORECAST TO APPROACH
FROM THE WEST AND IT MAY ARRIVE ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WE HAVE RECEIVED A FEW CALLS ABOUT SOME LIGHT SNOW ACROSS THE
NORTHERN AREAS. MUCH OF THE ACTIVITY IS LIGHT AND FALLING BELOW
THE RADAR BEAM. WE HAVE ADDED SOME CHC POPS TO THE FCST ACROSS THE
SRN POCONOS AND SUSSEX COUNTY NJ. OTHER THAN THAT...FEW CHANGES
WERE NEEDED TO THE EARLIER FCST. TEMPS AND DEW POINTS WERE NOT
CHANGED AND WINDS ONLY HAD SOME SLIGHT ADJUSTMENTS. PUBLIC
PRODUCTS HAVE BEEN UPDATED.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
NOT MUCH OF A CHANGE TO THE FORECAST TONIGHT FROM THE DAY TIME.
HIGH PRESSURE, CENTERED ACROSS NORTHERN NEW ENGLAND AND EASTERN
CANADA REMAINS IN CONTROL OF THE WEATHER. WITH CONTINUING LOW PW
VALUES, NO PRECIPITATION IS EXPECTED. CLOUD COVER SHOULD REMAIN
ACROSS THE AREA, ESPECIALLY AS A SHORT WAVE/VORTICITY MAX SLIDES
TOWARD THE AREA OVERNIGHT.

OVERNIGHT LOWS WERE A BLEND OF MAV/MET MOS AND MOSGUIDE WHICH
WERE IN PRETTY GOOD AGREEMENT.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
A MID LEVEL SHORT WAVE THAT WAS LOCATED OVER WESTERN IOWA AND
VICINITY EARLY THIS MORNING WILL PROGRESS EASTWARD AND IT SHOULD
PASS OVER OUR REGION EARLY ON SUNDAY MORNING. WHILE WE ARE
ANTICIPATING SOME CLOUDS WITH THE SYSTEM THERE SHOULD NOT BE
ENOUGH MOISTURE TO PRODUCE ANY PRECIPITATION.

SURFACE HIGH PRESSURE IS FORECAST TO BE LOCATED OVER SOUTHERN
QUEBEC ON SUNDAY MORNING. THE CENTER OF THE HIGH SHOULD DRIFT
EASTWARD REACHING ATLANTIC CANADA ON MONDAY AND MONDAY NIGHT. A
RIDGE AXIS IS EXPECTED TO NOSE SOUTHWESTWARD ALONG THE LEE OF THE
APPALACHIANS AT THAT TIME WITH AN INVERTED TROUGH DEVELOPING OFF
THE COAST. WEAK LOW PRESSURE IS ANTICIPATED TO DEVELOP ON THE
TROUGH OFF THE CAROLINA COAST ON MONDAY. THE FEATURE IS FORECAST
TO REMAIN WEAK AS IT DRIFTS NORTHEASTWARD REACHING THE WATERS OFF
THE DELMARVA BEFORE DISSIPATING ON TUESDAY.

AREAS OF LIGHT PRECIPITATION ARE EXPECTED TO SPREAD SLOWLY
NORTHWARD INTO OUR REGION ON MONDAY AND THEY SHOULD REMAIN HERE
FOR MONDAY NIGHT AND TUESDAY. THE OVERALL TREND WILL BE TOWARD
WARMING TEMPERATURES. AS A RESULT, MOST OF THE PRECIPITATION IS
ANTICIPATED TO BE IN THE FORM OF RAIN. HOWEVER, POCKETS OF BELOW
FREEZING TEMPERATURES MAY LINGER IN THE POCONOS ON MONDAY NIGHT
INTO EARLY TUESDAY MORNING SO WE HAVE MENTIONED A CHANCE OF
FREEZING RAIN THERE.

OUR MAIN WEATHER FEATURE FOR THE COMING WEEK IS THE DEEP MID
LEVEL TROUGH THAT IS FORECAST TO DIG OVER THE MIDDLE PART OF THE
COUNTRY ON MONDAY AND TUESDAY. THE TROUGH IS EXPECTED TO LIFT
NORTHEASTWARD AND ITS AXIS SHOULD PASS OVERHEAD EARLY ON THURSDAY.

SURFACE LOW PRESSURE IS ANTICIPATED TO DEVELOP OVER THE LOWER
MISSISSIPPI RIVER VALLEY ON TUESDAY IN RESPONSE TO THE TROUGH. THE
LOW IS FORECAST TO STRENGTHEN AS IT MOVES ACROSS THE GREAT LAKES
ON WEDNESDAY AND WEDNESDAY NIGHT. THE SYSTEM SHOULD HAVE AN
OPPORTUNITY TO TAP INTO GULF MOISTURE AND IT WILL BRING THE
POTENTIAL FOR SOME MODERATE TO HEAVY RAINFALL TO OUR REGION FROM
WEDNESDAY INTO EARLY WEDNESDAY NIGHT.

THE LOW IS EXPECTED TO PULL A WARM FRONT THROUGH OUR REGION ON
WEDNESDAY WITH TEMPERATURES FORECAST TO RISE INTO THE 50S AT MOST
LOCATIONS. SOME 60 DEGREE READINGS ARE POSSIBLE ON THE DELMARVA
AND PERHAPS IN FAR SOUTHERN NEW JERSEY. CONDITIONS MAY BECOME
QUITE BREEZY IN THE WARM SECTOR WHERE THE ATMOSPHERE SHOULD MIX
RATHER EFFICIENTLY. A STRONG COLD FRONT IS FORECAST TO FOLLOW ON
WEDNESDAY NIGHT WITH TEMPERATURES DROPPING BACK INTO THE 30S BY
DAYBREAK ON THURSDAY. THE PROBABILITY OF PRECIPITATION DECREASES
RAPIDLY ON WEDNESDAY NIGHT AS DRY AIR IS EXPECTED TO BUILD INTO
OUR REGION FROM THE SOUTHWEST.

RIDGING IS FORECAST TO DEVELOP AT THE SURFACE AND ALOFT FOR
THURSDAY INTO FRIDAY WITH MAINLY DRY WEATHER AND SEASONABLE
TEMPERATURES ANTICIPATED.

A MID LEVEL SHORT WAVE MAY APPROACH FROM THE WEST ON SATURDAY
ALONG WITH AN ASSOCIATED SURFACE COLD FRONT. THE GUIDANCE DIFFERS
A BIT ON THE TIMING OF THE FEATURE AT THIS POINT AS WELL ON THE
AMOUNT OF MOISTURE ASSOCIATED WITH THE SYSTEM.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

MOST OF THE TAF SITES ARE NOW MVFR, EXCEPT PHL/ILG/MIV, ALTHOUGH
THEY SHOULD BE THERE SHORTLY. THE MVFR CIGS WILL CONTINUE ACROSS
THE TAF SITES THROUGH THIS MORNING AS MOISTURE REMAINS TRAPPED
UNDERNEATH THE INVERSION. CLOUDS MAY SCATTER OUT DURING THE DAY
WITH HIGHER LEVEL CLOUDS OVERHEAD, LEADING TO VFR CONDITIONS FOR
THE REMAINDER OF THE PERIOD. IF THE CLOUDS DO NOT BEGIN TO SCATTER
OUT BY MIDDAY, IT`S POSSIBLE WE COULD SEE AN EXTENDED PERIOD OF
MVFR CIGS THROUGH THE DAY INTO TONIGHT.

NORTHERLY WINDS WILL BE LIGHT, GENERALLY AROUND 5-10 KNOTS OR
LESS THROUGH THE DAY. SOME NORTHWEST TO WEST WINDS ARE POSSIBLE
EARLY, BUT SHOULD BECOME MORE NORTHERLY DURING THE DAY. EVERYONE
IS EXPECTED TO BECOME LIGHT AND VARIABLE/CALM LATER THIS AFTERNOON
INTO THE EVENING/OVERNIGHT.

OUTLOOK...
SUNDAY AND SUNDAY NIGHT...MAINLY VFR.

MONDAY...MAINLY VFR WITH A CHANCE OF LIGHT RAIN SPREADING
NORTHWARD INTO OUR REGION.

MONDAY NIGHT AND TUESDAY...CONDITIONS POSSIBLY LOWERING INTO THE
MVFR CATEGORY WITH A CHANCE OF LIGHT RAIN.

TUESDAY NIGHT...MVFR AND IFR CONDITIONS ANTICIPATED WITH RAIN
LIKELY.

WEDNESDAY...MVFR AND IFR CONDITIONS WITH RAIN LIKELY. THE RAIN
MAY BE HEAVY AT TIMES. A GUSTY SOUTH WIND MAY DEVELOP, ESPECIALLY
IN THE AFTERNOON.

&&

.MARINE...
SUB-SMALL CRAFT ADVISORY CONDITIONS WILL REMAIN TODAY INTO
TONIGHT AS HIGH PRESSURE FROM THE NORTH WILL AFFECT THE WATERS.

OUTLOOK...
SUNDAY THROUGH MONDAY NIGHT...NO MARINE HEADLINES ARE
ANTICIPATED.

TUESDAY AND TUESDAY NIGHT...WAVE HEIGHTS ON OUR OCEAN WATERS MAY
BUILD TO 5 TO 6 FEET IN A DEVELOPING ONSHORE FLOW.

WEDNESDAY...SOUTHERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 6 TO 9
FEET IN A STRONG SOUTHERLY FLOW.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...IOVINO
NEAR TERM...OHARA
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/ROBERTSON
MARINE...IOVINO/ROBERTSON







000
FXUS61 KPHI 201548
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1048 AM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER SOUTHWESTERN QUEBEC THIS MORNING WILL
DRIFT EASTWARD AND IT SHOULD REACH ATLANTIC CANADA ON MONDAY. WEAK
LOW PRESSURE IS FORECAST TO DEVELOP OFF THE CAROLINA COAST ON
MONDAY BEFORE MOVING SLOWLY NORTHEASTWARD AND DISSIPATING. STRONG
LOW PRESSURE IS EXPECTED TO LIFT NORTHWARD FROM THE LOWER
MISSISSIPPI RIVER VALLEY AND ACROSS THE GREAT LAKES DURING THE MID
WEEK PERIOD. THE LOW IS ANTICIPATED TO PULL A WARM FRONT THROUGH
OUR REGION ON WEDNESDAY, FOLLOWED BY A COLD FRONT ON WEDNESDAY
NIGHT. HIGH PRESSURE IS EXPECTED TO FOLLOW FROM THE SOUTHWEST FOR
THURSDAY AND FRIDAY. ANOTHER COLD FRONT IS FORECAST TO APPROACH
FROM THE WEST AND IT MAY ARRIVE ON SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WE HAVE RECEIVED A FEW CALLS ABOUT SOME LIGHT SNOW ACROSS THE
NORTHERN AREAS. MUCH OF THE ACTIVITY IS LIGHT AND FALLING BELOW
THE RADAR BEAM. WE HAVE ADDED SOME CHC POPS TO THE FCST ACROSS THE
SRN POCONOS AND SUSSEX COUNTY NJ. OTHER THAN THAT...FEW CHANGES
WERE NEEDED TO THE EARLIER FCST. TEMPS AND DEW POINTS WERE NOT
CHANGED AND WINDS ONLY HAD SOME SLIGHT ADJUSTMENTS. PUBLIC
PRODUCTS HAVE BEEN UPDATED.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
NOT MUCH OF A CHANGE TO THE FORECAST TONIGHT FROM THE DAY TIME.
HIGH PRESSURE, CENTERED ACROSS NORTHERN NEW ENGLAND AND EASTERN
CANADA REMAINS IN CONTROL OF THE WEATHER. WITH CONTINUING LOW PW
VALUES, NO PRECIPITATION IS EXPECTED. CLOUD COVER SHOULD REMAIN
ACROSS THE AREA, ESPECIALLY AS A SHORT WAVE/VORTICITY MAX SLIDES
TOWARD THE AREA OVERNIGHT.

OVERNIGHT LOWS WERE A BLEND OF MAV/MET MOS AND MOSGUIDE WHICH
WERE IN PRETTY GOOD AGREEMENT.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
A MID LEVEL SHORT WAVE THAT WAS LOCATED OVER WESTERN IOWA AND
VICINITY EARLY THIS MORNING WILL PROGRESS EASTWARD AND IT SHOULD
PASS OVER OUR REGION EARLY ON SUNDAY MORNING. WHILE WE ARE
ANTICIPATING SOME CLOUDS WITH THE SYSTEM THERE SHOULD NOT BE
ENOUGH MOISTURE TO PRODUCE ANY PRECIPITATION.

SURFACE HIGH PRESSURE IS FORECAST TO BE LOCATED OVER SOUTHERN
QUEBEC ON SUNDAY MORNING. THE CENTER OF THE HIGH SHOULD DRIFT
EASTWARD REACHING ATLANTIC CANADA ON MONDAY AND MONDAY NIGHT. A
RIDGE AXIS IS EXPECTED TO NOSE SOUTHWESTWARD ALONG THE LEE OF THE
APPALACHIANS AT THAT TIME WITH AN INVERTED TROUGH DEVELOPING OFF
THE COAST. WEAK LOW PRESSURE IS ANTICIPATED TO DEVELOP ON THE
TROUGH OFF THE CAROLINA COAST ON MONDAY. THE FEATURE IS FORECAST
TO REMAIN WEAK AS IT DRIFTS NORTHEASTWARD REACHING THE WATERS OFF
THE DELMARVA BEFORE DISSIPATING ON TUESDAY.

AREAS OF LIGHT PRECIPITATION ARE EXPECTED TO SPREAD SLOWLY
NORTHWARD INTO OUR REGION ON MONDAY AND THEY SHOULD REMAIN HERE
FOR MONDAY NIGHT AND TUESDAY. THE OVERALL TREND WILL BE TOWARD
WARMING TEMPERATURES. AS A RESULT, MOST OF THE PRECIPITATION IS
ANTICIPATED TO BE IN THE FORM OF RAIN. HOWEVER, POCKETS OF BELOW
FREEZING TEMPERATURES MAY LINGER IN THE POCONOS ON MONDAY NIGHT
INTO EARLY TUESDAY MORNING SO WE HAVE MENTIONED A CHANCE OF
FREEZING RAIN THERE.

OUR MAIN WEATHER FEATURE FOR THE COMING WEEK IS THE DEEP MID
LEVEL TROUGH THAT IS FORECAST TO DIG OVER THE MIDDLE PART OF THE
COUNTRY ON MONDAY AND TUESDAY. THE TROUGH IS EXPECTED TO LIFT
NORTHEASTWARD AND ITS AXIS SHOULD PASS OVERHEAD EARLY ON THURSDAY.

SURFACE LOW PRESSURE IS ANTICIPATED TO DEVELOP OVER THE LOWER
MISSISSIPPI RIVER VALLEY ON TUESDAY IN RESPONSE TO THE TROUGH. THE
LOW IS FORECAST TO STRENGTHEN AS IT MOVES ACROSS THE GREAT LAKES
ON WEDNESDAY AND WEDNESDAY NIGHT. THE SYSTEM SHOULD HAVE AN
OPPORTUNITY TO TAP INTO GULF MOISTURE AND IT WILL BRING THE
POTENTIAL FOR SOME MODERATE TO HEAVY RAINFALL TO OUR REGION FROM
WEDNESDAY INTO EARLY WEDNESDAY NIGHT.

THE LOW IS EXPECTED TO PULL A WARM FRONT THROUGH OUR REGION ON
WEDNESDAY WITH TEMPERATURES FORECAST TO RISE INTO THE 50S AT MOST
LOCATIONS. SOME 60 DEGREE READINGS ARE POSSIBLE ON THE DELMARVA
AND PERHAPS IN FAR SOUTHERN NEW JERSEY. CONDITIONS MAY BECOME
QUITE BREEZY IN THE WARM SECTOR WHERE THE ATMOSPHERE SHOULD MIX
RATHER EFFICIENTLY. A STRONG COLD FRONT IS FORECAST TO FOLLOW ON
WEDNESDAY NIGHT WITH TEMPERATURES DROPPING BACK INTO THE 30S BY
DAYBREAK ON THURSDAY. THE PROBABILITY OF PRECIPITATION DECREASES
RAPIDLY ON WEDNESDAY NIGHT AS DRY AIR IS EXPECTED TO BUILD INTO
OUR REGION FROM THE SOUTHWEST.

RIDGING IS FORECAST TO DEVELOP AT THE SURFACE AND ALOFT FOR
THURSDAY INTO FRIDAY WITH MAINLY DRY WEATHER AND SEASONABLE
TEMPERATURES ANTICIPATED.

A MID LEVEL SHORT WAVE MAY APPROACH FROM THE WEST ON SATURDAY
ALONG WITH AN ASSOCIATED SURFACE COLD FRONT. THE GUIDANCE DIFFERS
A BIT ON THE TIMING OF THE FEATURE AT THIS POINT AS WELL ON THE
AMOUNT OF MOISTURE ASSOCIATED WITH THE SYSTEM.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

MOST OF THE TAF SITES ARE NOW MVFR, EXCEPT PHL/ILG/MIV, ALTHOUGH
THEY SHOULD BE THERE SHORTLY. THE MVFR CIGS WILL CONTINUE ACROSS
THE TAF SITES THROUGH THIS MORNING AS MOISTURE REMAINS TRAPPED
UNDERNEATH THE INVERSION. CLOUDS MAY SCATTER OUT DURING THE DAY
WITH HIGHER LEVEL CLOUDS OVERHEAD, LEADING TO VFR CONDITIONS FOR
THE REMAINDER OF THE PERIOD. IF THE CLOUDS DO NOT BEGIN TO SCATTER
OUT BY MIDDAY, IT`S POSSIBLE WE COULD SEE AN EXTENDED PERIOD OF
MVFR CIGS THROUGH THE DAY INTO TONIGHT.

NORTHERLY WINDS WILL BE LIGHT, GENERALLY AROUND 5-10 KNOTS OR
LESS THROUGH THE DAY. SOME NORTHWEST TO WEST WINDS ARE POSSIBLE
EARLY, BUT SHOULD BECOME MORE NORTHERLY DURING THE DAY. EVERYONE
IS EXPECTED TO BECOME LIGHT AND VARIABLE/CALM LATER THIS AFTERNOON
INTO THE EVENING/OVERNIGHT.

OUTLOOK...
SUNDAY AND SUNDAY NIGHT...MAINLY VFR.

MONDAY...MAINLY VFR WITH A CHANCE OF LIGHT RAIN SPREADING
NORTHWARD INTO OUR REGION.

MONDAY NIGHT AND TUESDAY...CONDITIONS POSSIBLY LOWERING INTO THE
MVFR CATEGORY WITH A CHANCE OF LIGHT RAIN.

TUESDAY NIGHT...MVFR AND IFR CONDITIONS ANTICIPATED WITH RAIN
LIKELY.

WEDNESDAY...MVFR AND IFR CONDITIONS WITH RAIN LIKELY. THE RAIN
MAY BE HEAVY AT TIMES. A GUSTY SOUTH WIND MAY DEVELOP, ESPECIALLY
IN THE AFTERNOON.

&&

.MARINE...
SUB-SMALL CRAFT ADVISORY CONDITIONS WILL REMAIN TODAY INTO
TONIGHT AS HIGH PRESSURE FROM THE NORTH WILL AFFECT THE WATERS.

OUTLOOK...
SUNDAY THROUGH MONDAY NIGHT...NO MARINE HEADLINES ARE
ANTICIPATED.

TUESDAY AND TUESDAY NIGHT...WAVE HEIGHTS ON OUR OCEAN WATERS MAY
BUILD TO 5 TO 6 FEET IN A DEVELOPING ONSHORE FLOW.

WEDNESDAY...SOUTHERLY WIND GUSTS IN EXCESS OF 25 KNOTS ARE
EXPECTED. WAVE HEIGHTS ON OUR OCEAN WATERS MAY BUILD TO 6 TO 9
FEET IN A STRONG SOUTHERLY FLOW.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...IOVINO
NEAR TERM...OHARA
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/ROBERTSON
MARINE...IOVINO/ROBERTSON






000
FXUS61 KAKQ 201536
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1036 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST THROUGH TONIGHT. HIGH PRESSURE WILL BE OVER
THE AREA AGAIN DURING SUNDAY. ANOTHER LOW PRESSURE AREA MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA COAST
LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
LATEST ANALYSIS SHOWS ~1028 MB SFC HIGH PRESSURE CENTERED OVER
EASTERN VA...WITH WEAK (~1018 MB) SFC LOW PRESSURE OVER SOUTHERN
GA/NORTH FL. ISENTROPIC LIFT PER 12Z NAM AT 285K SFC SEEMS TO HAVE
A DECENT HANDLE ON THE OVERRUNNING PRECIP FOCUSING OVER CENTRAL
AND EASTERN NC AND INTO FAR SOUTHERN VA. A FEW REPORTS OF -SN WITH
VSBYS 1-3 SM OVER CENTRAL NC. NAM/RAP DEPICTION OF SFC WET BULB
TEMPERATURES OF 32-33 F LINES UP FAIRLY WELL WITH RAIN/SNOW LINE.
HAVE ADDED FLURRIES TO PORTIONS OF CENTRAL VA ALONG/WEST OF I-95
THROUGH NOON...WITH 20-30% POPS FOR RAIN/SNOW DOWN NEAR THE VA/NC
BORDER AND FOR INTERIOR NE NC. PRECIP IS VERY LIGHT SO NO
ACCUMULATION EXPECTED ANYWHERE. FORCING/LIFT WEAKENS AND FOCUSES
OVER SE NC AFTER 18Z...SO WILL LIMIT POPS AFTER 18Z TO NE NC AND
FAR SE VA FOR JUST A LOW CHC (20-30%) OF LIGHT RAIN. CLOUDY TO MOSTLY
CLOUDY TODAY WITH HIGHS IN THE UPPER 30S NW TO MID 40S SE.

SFC HIGH PRESSURE REBOUNDS TONIGHT WITH DECREASING CLOUDS. LOWS IN
THE MID 20S NORTH TO THE LOW 30S SOUTH.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. SEASONABLE HIGHS OF 45-50.

NEXT SYSTEM...THIS ONE MORE AMPLIFIED WILL AFFECT THE AREA ON
MON...WITH LIKELY TO CATEGORICAL POPS ALL ZONES MON AM/MON AFTN.
LOOKS LIKE ALL RAIN ASIDE FROM A BRIEF MIX POSSIBLE AT ONSET IN
FAR NW COUNTIES. AT THIS POINT...IT DOES NOT APPEAR ENOUGH FROZEN
PCPN WOULD OCCUR TO CAUSE ANY CONCERNS. LOWS SUNDAY NIGHT FROM
AROUND 30 NW TO AROUND 40 VA BEACH. HIGHS MON ONLY AROUND 40 NW
TO THE MID 50S FAR SE IN CAD SETUP.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
LOW PRESSURE LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING
FROM SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE
REGION TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM
THE GULF STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE
MAINTAINED. A VERY DYNAMIC SYSTEM LIFTS NNE WEST OF THE
APPALACHIANS TUESDAY NIGHT WITH THE ATTENDANT COLD FRONT CROSSING
THE MID-ATLANTIC WEDNESDAY. THE FIRST POTENTIAL OF RAIN ARRIVES
TUESDAY NIGHT ASSOCIATED WITH MOIST WAA. THE SECOND POTENTIAL WILL
BE WEDNESDAY AHEAD OF THE COLD FRONT. THERE IS A POTENTIAL FOR
THUNDER WEDNESDAY AS SURFACE DEWPOINTS POTENTIALLY EXCEED 60F
(ESPECIALLY OVER THE COASTAL PLAIN). THE PATTERN DOES SUPPORT THE
POSSIBILITY OF A DYNAMICALLY FORCED LINE OF CONVECTION CONTAINING
STRONG WIND GUSTS AS CURRENT FORECAST GUIDANCE SUGGESTS A
925-700MB WIND FIELD AVERAGING 40-50KT. THIS WOULD BE A
CLIMATOLOGICALLY RARITY THIS TIME OF YEAR...SO CONFIDENCE IS ON
THE LOW-SIDE GIVEN THAT THIS IS 5-6 DAYS OUT. TEMPERATURES WILL BE
VERY MILD AHEAD OF THE FRONT TUESDAY AND WEDNESDAY...WITH HIGHS
AVERAGING FROM THE MID 50S NW...TO MID/UPPER 60S SE. DRY AND
BREEZY CONDITIONS WILL LIKELY PREVAIL BY CHRISTMAS DAY...WITH HIGH
TEMPERATURES OF 50-55. THE FLOW BECOMES MORE SW BY FRIDAY WITH
CURRENT FORECAST HIGHS OF 55-60...BUT 60-65 IS POSSIBLE BASED ON
LOW-LEVEL THICKNESS FIELDS.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDS IN PLACE ACROSS THE REGION THIS MORNING, WITH
PREDOMINATELY VFR CONDS TO PERSIST THROUGH THE TAF PERIOD. HIGH
PRESSURE WILL CONTINUE TO RIDGE SOUTH ACROSS THE REGION FROM THE
EASTERN GREAT LAKES/NORTHEAST THROUGH THE TAF PERIOD, AS AN UPPER
LEVEL DISTURBANCE MOVES ACROSS THE SOUTHEAST TOWARD THE CAROLINAS
TODAY, WHILE ASSOCIATED WEAK SFC LOW MOVES ACROSS THE SOUTHEAST
TODAY AND TONIGHT. EAST FLOW WILL ALLOW FOR LOWERING CIGS THROUGH
THE MORNING, WITH OVC AT 5-8 KFT AGL EXPECTED THROUGH AFTN.
FORCING WILL BE ENOUGH FOR SOME SPOTTY LIGHT RAIN SHRAS, MAINLY IN
FAR SRN PORTIONS OF THE AREA. PERIODIC MVFR CIGS WILL BE POSSIBLE
ACROSS PHF/ORF/ECG AFTER 18Z. HOWEVER, RAIN SHOULD BE LIGHT ENOUGH
TO PRECLUDE ANY VSBY RESTRICTIONS. HV GONE WITH PREDOMINATE SHRA
AT ECG THIS AFTN, WITH VICINITY WORDING AT ORF/PHF/RIC.

OUTLOOK...ANY PRECIP COMES TO AN END EARLY SATURDAY EVENING AND
CONDITIONS WILL GRADUALLY IMPROVE FROM WEST TO EAST THROUGH THE REST
OF SAT NIGHT. HIGH PRESSURE BUILDS TO THE NORTH OF THE AREA SUNDAY.
A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL BOUNDARIES WILL
BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS AND VISIBILITIES
BEGINNING MONDAY.

&&

.MARINE...
LATEST OBS HIGH PRESSURE SPREADS EAST ACROSS NEW ENGLAND THROUGH
TONIGHT, RIDGING SOUTH INTO THE AREA TODAY. MEANWHILE, WEAK SFC LOW
PRESSURE WILL PASS SOUTH OF THE REGION LATER TODAY AND TONIGHT. THIS
WILL MAINTAIN LIGHT NORTHERLY FLOW ~10 KT OVER THE MARINE AREA
TODAY. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY NIGHT, AS LOW
PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY NIGHT BEFORE
TRACKING NE OFF THE LOWER MID ATLANTIC COAST LATER MONDAY AND MONDAY
NIGHT. THE RESULTANT TIGHTENING SURFACE PRESSURE GRADIENT WILL ALLOW
ONSHORE (EAST) FLOW TO GRADUALLY INCREASE MONDAY AFTN, GRADUALLY
BUILDING SEAS MONDAY NIGHT AND EARLY TUESDAY. 15-20KT EASTERLY FLOW
OVER THE OCEAN AND LOWER BAY COULD PRODUCE A PERIOD OF SCA
CONDITIONS ESPECIALLY OVER THE SRN OCEAN ZONES (MAINLY FOR SEAS) AND
LOWER BAY/MOUTH OF JAMES. THERE IS NO CAA IN THE WAKE OF THIS
LOW...SO SUB-SCA CONDITIONS SHOULD PREVAIL BEHIND THE SYSTEM LATER
MONDAY NIGHT INTO TUESDAY.

A STRONG LOW PRESSURE SYSTEM LOOKS TO DEVELOP ACROSS THE OHIO
VALLEY, TRACKING WEST OF THE MOUNTAINS TUESDAY NIGHT. HOWEVER, THIS
SYSTEM WILL PUSH A STRONG COLD FRONT ACROSS THE MID ATLANTIC COAST
LATER WEDNESDAY. SCA CONDITIONS ARE LIKELY WEDNESDAY NIGHT INTO
CHRISTMAS DAY AS HIGH PRESSURE BUILDS IN FROM THE WNW.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...JDM
NEAR TERM...JDM/LKB
SHORT TERM...JDM/LKB
LONG TERM...AJZ/MAS
AVIATION...MAM
MARINE...MAM






000
FXUS61 KPBZ 201445
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
945 AM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
SHORTWAVE TROUGH WILL SWING THROUGH THE OHIO VALLEY AND ACROSS THE
CWA DURING THE EARLY PART OF THE NIGHT. EXPECTING CLOUD COVER TO
BE MAINTAINED THROUGH THE PERIOD WITH AN OVERALL THIN BUT
PERSISTENT MOISTURE LAYER A COUPLE THOUSAND FEET UP.  WHILE
MOISTURE IS OTHERWISE FAIRLY MEAGER AT PRESENT...SW FLOW AT H850
WILL HELP PUSH MARGINALLY BETTER PWAT VALUES INTO THE SOUTHERN
COUNTIES BY SUNSET. THIS COMBINED WITH MODEST SUPPORT FROM SHORTWAVE MAY
ALLOW A FEW SNOWFLAKES TO SQUEEZE OUT...SO ADDED A SLIGHT CHANCE
POP TO THE GRIDS...MAINLY FOR THE EVENING...GENERALLY SOUTH OF A
HLG/PIT/IDI LINE. ANY ACTIVITY SHOULD END SOON AFTER 06Z WITH
SHORTWAVE DEPARTURE. TEMPERATURE FORECAST LOOKS DECENT OVERALL AT
THIS TIME.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
MODELS ARE SHOWING SOME IMPROVEMENT SUNDAY...PARTICULARLY OVER
THE WEST AND FAR SOUTH. HOWEVER...MODEL SOUNDINGS FOR THE REST OF
THE REGION STILL WANT TO MAINTAIN A SATURATED LAYER AROUND 2500FT
FOR MOST OF THE DAY...WHICH DOES NOT PRESENT MUCH HOPE FOR
SUNSHINE. CLOUDS WILL BE TRICKY ON SUNDAY...TRYING TO DETERMINE
HOW MUCH OF THE CLOUD DECK WILL BE ERODED.

SPLIT FLOW DEVELOPS ON MONDAY WITH A LARGE SYSTEM TO THE WEST AND
ANOTHER SYSTEM TO THE SOUTH-SOUTHEAST. IT APPEARS THAT THE AREA
WILL LIE IN BETWEEN LIMITING THE CHANCES FOR PRECIPITATION. WAA
WILL CONTINUE ON MONDAY AND LOW-LEVEL MOISTURE INCREASES ONCE
AGAIN. LOOKS LIKE A GOOD DEAL OF CLOUD COVER AGAIN MONDAY. A WEAK
AND UNORGANIZED SHORTWAVE TROUGH WILL SWING THROUGH MONDAY...
ALLOWING FOR THE POSSIBILITY OF SOME LIGHT PRECIP...MAINLY OVER
THE SOUTHERN RIDGES. THIS WILL NEED TO BE FINE TUNED AS THE WARMER
AIR ALOFT MAY OCCUR BEFORE SURFACE TEMPS RESPOND. CONFIDENCE IS
LOW THAT ANY PRECIP WILL OCCUR...SO FOR FORECAST WILL LEAVE OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
STILL SEEING SOME MINOR DIFFERENCES IN MEDIUM RANGE MODEL
SOLUTIONS FOR MIDWEEK SYSTEM. THINK MUCH OF TUESDAY COULD BE DRY
OR JUST LIGHT SHOWERS AS AREA WILL BE WELL INTO THE WARM SECTOR. RAIN
WILL OVERSPREAD THE AREA TUESDAY NIGHT AHEAD OF OCCLUDED FRONT AND
CONTINUE THROUGH WEDNESDAY. COLDER AIR WILL MOVE IN LATER
WEDNESDAY NIGHT CHANGING ANY LINGERING SHOWERS TO SNOW SHOWERS.
COULD SEE A BRIEF UPTICK IN SNOW SHOWER COVERAGE EARLY THURSDAY
MORNING AS MAIN TROUGH SWINGS THROUGH. COLD AIR WILL BE IN PLACE
THURSDAY...BUT WIND DIRECTION NOT OPTIMAL FOR LAKE INFLUENCED SNOW
SHOWERS.

WARMER AIR WILL MOVE BACK IN THURSDAY NIGHT AND FRIDAY.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
LOW LEVEL MOISTURE WILL REMAIN TRAPPED UNDER A STRONG INVERSION
AOB 4KFT AS LOW LEVEL WINDS BECOME LIGHT....MAINTAINING HIGH MVFR
TO LOW VFR CONDITIONS OVER THE NEXT 24 HOURS. PRECIPITATION
CHANCES ARE MINIMAL GIVEN THE SHALLOW DEPTH OF THE SATURATED
LAYER AND ABSENCE OF ANY LIFT.

OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST THROUGH THE WEEKEND. NEXT STORM
SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND RESULT IN
WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF LLWS
THROUGH WEDNESDAY.

&&

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

&&

$$






000
FXUS61 KPBZ 201445
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
945 AM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
SHORTWAVE TROUGH WILL SWING THROUGH THE OHIO VALLEY AND ACROSS THE
CWA DURING THE EARLY PART OF THE NIGHT. EXPECTING CLOUD COVER TO
BE MAINTAINED THROUGH THE PERIOD WITH AN OVERALL THIN BUT
PERSISTENT MOISTURE LAYER A COUPLE THOUSAND FEET UP.  WHILE
MOISTURE IS OTHERWISE FAIRLY MEAGER AT PRESENT...SW FLOW AT H850
WILL HELP PUSH MARGINALLY BETTER PWAT VALUES INTO THE SOUTHERN
COUNTIES BY SUNSET. THIS COMBINED WITH MODEST SUPPORT FROM SHORTWAVE MAY
ALLOW A FEW SNOWFLAKES TO SQUEEZE OUT...SO ADDED A SLIGHT CHANCE
POP TO THE GRIDS...MAINLY FOR THE EVENING...GENERALLY SOUTH OF A
HLG/PIT/IDI LINE. ANY ACTIVITY SHOULD END SOON AFTER 06Z WITH
SHORTWAVE DEPARTURE. TEMPERATURE FORECAST LOOKS DECENT OVERALL AT
THIS TIME.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
MODELS ARE SHOWING SOME IMPROVEMENT SUNDAY...PARTICULARLY OVER
THE WEST AND FAR SOUTH. HOWEVER...MODEL SOUNDINGS FOR THE REST OF
THE REGION STILL WANT TO MAINTAIN A SATURATED LAYER AROUND 2500FT
FOR MOST OF THE DAY...WHICH DOES NOT PRESENT MUCH HOPE FOR
SUNSHINE. CLOUDS WILL BE TRICKY ON SUNDAY...TRYING TO DETERMINE
HOW MUCH OF THE CLOUD DECK WILL BE ERODED.

SPLIT FLOW DEVELOPS ON MONDAY WITH A LARGE SYSTEM TO THE WEST AND
ANOTHER SYSTEM TO THE SOUTH-SOUTHEAST. IT APPEARS THAT THE AREA
WILL LIE IN BETWEEN LIMITING THE CHANCES FOR PRECIPITATION. WAA
WILL CONTINUE ON MONDAY AND LOW-LEVEL MOISTURE INCREASES ONCE
AGAIN. LOOKS LIKE A GOOD DEAL OF CLOUD COVER AGAIN MONDAY. A WEAK
AND UNORGANIZED SHORTWAVE TROUGH WILL SWING THROUGH MONDAY...
ALLOWING FOR THE POSSIBILITY OF SOME LIGHT PRECIP...MAINLY OVER
THE SOUTHERN RIDGES. THIS WILL NEED TO BE FINE TUNED AS THE WARMER
AIR ALOFT MAY OCCUR BEFORE SURFACE TEMPS RESPOND. CONFIDENCE IS
LOW THAT ANY PRECIP WILL OCCUR...SO FOR FORECAST WILL LEAVE OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
STILL SEEING SOME MINOR DIFFERENCES IN MEDIUM RANGE MODEL
SOLUTIONS FOR MIDWEEK SYSTEM. THINK MUCH OF TUESDAY COULD BE DRY
OR JUST LIGHT SHOWERS AS AREA WILL BE WELL INTO THE WARM SECTOR. RAIN
WILL OVERSPREAD THE AREA TUESDAY NIGHT AHEAD OF OCCLUDED FRONT AND
CONTINUE THROUGH WEDNESDAY. COLDER AIR WILL MOVE IN LATER
WEDNESDAY NIGHT CHANGING ANY LINGERING SHOWERS TO SNOW SHOWERS.
COULD SEE A BRIEF UPTICK IN SNOW SHOWER COVERAGE EARLY THURSDAY
MORNING AS MAIN TROUGH SWINGS THROUGH. COLD AIR WILL BE IN PLACE
THURSDAY...BUT WIND DIRECTION NOT OPTIMAL FOR LAKE INFLUENCED SNOW
SHOWERS.

WARMER AIR WILL MOVE BACK IN THURSDAY NIGHT AND FRIDAY.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
LOW LEVEL MOISTURE WILL REMAIN TRAPPED UNDER A STRONG INVERSION
AOB 4KFT AS LOW LEVEL WINDS BECOME LIGHT....MAINTAINING HIGH MVFR
TO LOW VFR CONDITIONS OVER THE NEXT 24 HOURS. PRECIPITATION
CHANCES ARE MINIMAL GIVEN THE SHALLOW DEPTH OF THE SATURATED
LAYER AND ABSENCE OF ANY LIFT.

OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST THROUGH THE WEEKEND. NEXT STORM
SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND RESULT IN
WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF LLWS
THROUGH WEDNESDAY.

&&

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

&&

$$







000
FXUS61 KLWX 201421
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
921 AM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST THROUGH SUNDAY. LOW PRESSURE WILL
TRACK UP THE MID-ATLANTIC COAST LATE MONDAY. A STRONG COLD FRONT
WILL THEN PASS THROUGH THE AREA LATE WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
A SHORTWAVE WILL PASS THROUGH THE REGION TODAY...CAUSING HIGH AND
MID-LEVEL CLOUDS WHILE SURFACE HIGH PRESSURE BUILDS OVERHEAD.
SEASONABLY CHILLY CONDITIONS WILL CONTINUE...BUT THE DEEP MOISTURE
FROM THIS SYSTEM IS EXPECTED TO REMAIN TO OUR SOUTH.
THEREFORE...MOST AREAS WILL TURN OUT DRY. A FEW FLURRIES OR
PERHAPS A PERIOD OF LIGHT SNOW CANNOT BE RULED OUT ACROSS CENTRAL
VIRGINIA INTO THE POTOMAC HIGHLANDS...BUT LITTLE OR NO SNOW
ACCUMULATION IS EXPECTED.

MULTIPLE ROUNDS OF ENERGY WILL PASS OVER THE MID-ATLANTIC THROUGH
TONIGHT. DUE TO LITTLE FORCING AS THE JET STREAM IS FURTHER
SOUTH...DRY CONDITIONS ARE EXPECTED THROUGH TONIGHT. SUBSIDENCE
BEHIND ANY VORT MAXES MAY LEAD TO SOME CLEARING. FCST MIN TEMPS
SHOULD BE IN THE UPPER 20S TO LOW 30S IN URBAN AREAS. CLEARING MAY
RESULT IN TEMPS DROPPING A FEW MORE DEGREES.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
HIGH PRESSURE EXTENDS FROM NEW ENGLAND DOWN INTO THE MID-ATLANTIC
SUNDAY. MODELS SUGGEST A GOOD DEAL OF SUNSHINE WITH MAXIMA NEAR
CLIMO.

HIGH PRESSURE EDGES A LITTLE EAST SUNDAY NIGHT INTO MONDAY...WITH
PRESSURE PATTERN SIGNALING SOME SEMBLANCE OF A WEDGE. AT THE SAME
TIME...SOUTHERN STREAM SHORTWAVE ENERGY IS ALSO FORECAST TO MOVE
NORTHEAST ON MONDAY.

RESULT WILL BE INCREASING/THICKENING CLOUDS SUNDAY NIGHT BUT THINK
ANY PRECIP WILL REMAIN TO THE SOUTH THROUGH DAYBREAK. TREND OF THE
MODELS IS TO DELAY PRECIP A LITTLE LONGER DURING THE DAY MONDAY.
LEANED TOWARD ECMWF/SREFS FOR TIMING. BUT IF PRECIP ARRIVES EARLY
ENOUGH...MONDAY MORNING MAY SEE A WINTRY MIX OF PRECIP PARTICULARLY
BLUE RIDGE WESTWARD. BULK OF THE PRECIP MONDAY AFTERNOON/EVENING
APPEARS TO BE RAIN BUT A WINTRY MIX INCLUDING POTENTIAL ICING FROM
FREEZING RAIN MAY LINGER ACROSS THE HIGHER ELEVATIONS OF THE POTOMAC
HIGHLANDS INTO MONDAY EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
SHORTWAVE EXITS LATE MONDAY NIGHT...BUT THE WEDGE REMAINS INTO
TUESDAY AND WITH LOW LEVEL MOISTURE IN PLACE CHANCE OF RAIN OR
DRIZZLE CONTINUES.

ATTENTION THEN TURNS TO A DEEP/STRONG UPPER LEVEL TROUGH SENDING
A COLD FRONT THROUGH LATE WEDNESDAY. DECENT LOW LEVEL JET AND
PLUME OF MOISTURE ARE EXPECTED TO BE TRANSPORTED AHEAD OF THE
FRONT ON WEDNESDAY...LEADING TO SHOWERS. MAXIMA ARE EXPECTED TO
BE WARM FOR THIS TIME OF YEAR AND HAVE TRENDED MAXIMA NEAR 60 EAST
OF THE BLUE RIDGE FOR WEDNESDAY.

DYNAMIC SYSTEM MOVES AWAY WEDNESDAY NIGHT. TIGHT GRADIENT AND COLD
ADVECTION BRING A WINDY AND COOLER CHRISTMAS DAY...ALTHOUGH MAXIMA
MAY ACTUALLY STILL BE A FEW DEGREES ABOVE CLIMO.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED THROUGH TONIGHT. HIGH AND MID-LEVEL CLOUDS
ARE EXPECTED DURING THIS TIME. A FEW FLURRIES CANNOT BE RULED OUT
TODAY...BUT MOST LOCATIONS WILL BE DRY. WINDS WILL BE
LIGHT...GENERALLY AROUND 5 KNOTS OR LESS. HIGH PRESSURE WILL
CONTROL THE WEATHER PATTERN FOR SUNDAY WITH VFR CONDITIONS AND
LIGHT WINDS.

DEVELOPING WEDGE AND AREA OF LOW PRESSURE WILL LIKELY BRING SOME
RAIN AND AT LEAST MVFR CONDITIONS MONDAY. IF PRECIP ARRIVES EARLY
ENOUGH MONDAY MORNING...IT MAY BEGIN AS A MIX.

IFR OR LOWER CONDITIONS ARE THEN EXPECTED MONDAY NIGHT INTO TUESDAY
WITH WEDGE IN PLACE AND AREAS OF RAIN OR DRIZZLE. STRONG COLD FRONT
FOLLOWS LATE WEDNESDAY WITH SHOWERS/POSSIBLY GUSTY WINDS.

&&

.MARINE...
HIGH PRESSURE WILL PERSIST ACROSS THE WATERS TODAY AND TONIGHT. NW
WINDS 5-10KTS ARE EXPECTED ON THE WATERS TODAY AND WEAKEN FURTHER
INTO TONIGHT.

HIGH PRESSURE OVER NEW ENGLAND ON SUNDAY MOVES OFFSHORE EARLY IN THE
WEEK. SCA CONDITIONS ARE POSSIBLE IN SOUTHERLY FLOW AHEAD OF A COLD
FRONT ON WEDNESDAY...THEN BEHIND THE FRONT FOR WEDNESDAY NIGHT AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BPP/HAS
NEAR TERM...BJL/HAS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...BJL/BPP/HAS
MARINE...BPP/HAS







000
FXUS61 KLWX 201421
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
921 AM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST THROUGH SUNDAY. LOW PRESSURE WILL
TRACK UP THE MID-ATLANTIC COAST LATE MONDAY. A STRONG COLD FRONT
WILL THEN PASS THROUGH THE AREA LATE WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
A SHORTWAVE WILL PASS THROUGH THE REGION TODAY...CAUSING HIGH AND
MID-LEVEL CLOUDS WHILE SURFACE HIGH PRESSURE BUILDS OVERHEAD.
SEASONABLY CHILLY CONDITIONS WILL CONTINUE...BUT THE DEEP MOISTURE
FROM THIS SYSTEM IS EXPECTED TO REMAIN TO OUR SOUTH.
THEREFORE...MOST AREAS WILL TURN OUT DRY. A FEW FLURRIES OR
PERHAPS A PERIOD OF LIGHT SNOW CANNOT BE RULED OUT ACROSS CENTRAL
VIRGINIA INTO THE POTOMAC HIGHLANDS...BUT LITTLE OR NO SNOW
ACCUMULATION IS EXPECTED.

MULTIPLE ROUNDS OF ENERGY WILL PASS OVER THE MID-ATLANTIC THROUGH
TONIGHT. DUE TO LITTLE FORCING AS THE JET STREAM IS FURTHER
SOUTH...DRY CONDITIONS ARE EXPECTED THROUGH TONIGHT. SUBSIDENCE
BEHIND ANY VORT MAXES MAY LEAD TO SOME CLEARING. FCST MIN TEMPS
SHOULD BE IN THE UPPER 20S TO LOW 30S IN URBAN AREAS. CLEARING MAY
RESULT IN TEMPS DROPPING A FEW MORE DEGREES.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
HIGH PRESSURE EXTENDS FROM NEW ENGLAND DOWN INTO THE MID-ATLANTIC
SUNDAY. MODELS SUGGEST A GOOD DEAL OF SUNSHINE WITH MAXIMA NEAR
CLIMO.

HIGH PRESSURE EDGES A LITTLE EAST SUNDAY NIGHT INTO MONDAY...WITH
PRESSURE PATTERN SIGNALING SOME SEMBLANCE OF A WEDGE. AT THE SAME
TIME...SOUTHERN STREAM SHORTWAVE ENERGY IS ALSO FORECAST TO MOVE
NORTHEAST ON MONDAY.

RESULT WILL BE INCREASING/THICKENING CLOUDS SUNDAY NIGHT BUT THINK
ANY PRECIP WILL REMAIN TO THE SOUTH THROUGH DAYBREAK. TREND OF THE
MODELS IS TO DELAY PRECIP A LITTLE LONGER DURING THE DAY MONDAY.
LEANED TOWARD ECMWF/SREFS FOR TIMING. BUT IF PRECIP ARRIVES EARLY
ENOUGH...MONDAY MORNING MAY SEE A WINTRY MIX OF PRECIP PARTICULARLY
BLUE RIDGE WESTWARD. BULK OF THE PRECIP MONDAY AFTERNOON/EVENING
APPEARS TO BE RAIN BUT A WINTRY MIX INCLUDING POTENTIAL ICING FROM
FREEZING RAIN MAY LINGER ACROSS THE HIGHER ELEVATIONS OF THE POTOMAC
HIGHLANDS INTO MONDAY EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
SHORTWAVE EXITS LATE MONDAY NIGHT...BUT THE WEDGE REMAINS INTO
TUESDAY AND WITH LOW LEVEL MOISTURE IN PLACE CHANCE OF RAIN OR
DRIZZLE CONTINUES.

ATTENTION THEN TURNS TO A DEEP/STRONG UPPER LEVEL TROUGH SENDING
A COLD FRONT THROUGH LATE WEDNESDAY. DECENT LOW LEVEL JET AND
PLUME OF MOISTURE ARE EXPECTED TO BE TRANSPORTED AHEAD OF THE
FRONT ON WEDNESDAY...LEADING TO SHOWERS. MAXIMA ARE EXPECTED TO
BE WARM FOR THIS TIME OF YEAR AND HAVE TRENDED MAXIMA NEAR 60 EAST
OF THE BLUE RIDGE FOR WEDNESDAY.

DYNAMIC SYSTEM MOVES AWAY WEDNESDAY NIGHT. TIGHT GRADIENT AND COLD
ADVECTION BRING A WINDY AND COOLER CHRISTMAS DAY...ALTHOUGH MAXIMA
MAY ACTUALLY STILL BE A FEW DEGREES ABOVE CLIMO.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED THROUGH TONIGHT. HIGH AND MID-LEVEL CLOUDS
ARE EXPECTED DURING THIS TIME. A FEW FLURRIES CANNOT BE RULED OUT
TODAY...BUT MOST LOCATIONS WILL BE DRY. WINDS WILL BE
LIGHT...GENERALLY AROUND 5 KNOTS OR LESS. HIGH PRESSURE WILL
CONTROL THE WEATHER PATTERN FOR SUNDAY WITH VFR CONDITIONS AND
LIGHT WINDS.

DEVELOPING WEDGE AND AREA OF LOW PRESSURE WILL LIKELY BRING SOME
RAIN AND AT LEAST MVFR CONDITIONS MONDAY. IF PRECIP ARRIVES EARLY
ENOUGH MONDAY MORNING...IT MAY BEGIN AS A MIX.

IFR OR LOWER CONDITIONS ARE THEN EXPECTED MONDAY NIGHT INTO TUESDAY
WITH WEDGE IN PLACE AND AREAS OF RAIN OR DRIZZLE. STRONG COLD FRONT
FOLLOWS LATE WEDNESDAY WITH SHOWERS/POSSIBLY GUSTY WINDS.

&&

.MARINE...
HIGH PRESSURE WILL PERSIST ACROSS THE WATERS TODAY AND TONIGHT. NW
WINDS 5-10KTS ARE EXPECTED ON THE WATERS TODAY AND WEAKEN FURTHER
INTO TONIGHT.

HIGH PRESSURE OVER NEW ENGLAND ON SUNDAY MOVES OFFSHORE EARLY IN THE
WEEK. SCA CONDITIONS ARE POSSIBLE IN SOUTHERLY FLOW AHEAD OF A COLD
FRONT ON WEDNESDAY...THEN BEHIND THE FRONT FOR WEDNESDAY NIGHT AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BPP/HAS
NEAR TERM...BJL/HAS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...BJL/BPP/HAS
MARINE...BPP/HAS







000
FXUS61 KLWX 201421
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
921 AM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST THROUGH SUNDAY. LOW PRESSURE WILL
TRACK UP THE MID-ATLANTIC COAST LATE MONDAY. A STRONG COLD FRONT
WILL THEN PASS THROUGH THE AREA LATE WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
A SHORTWAVE WILL PASS THROUGH THE REGION TODAY...CAUSING HIGH AND
MID-LEVEL CLOUDS WHILE SURFACE HIGH PRESSURE BUILDS OVERHEAD.
SEASONABLY CHILLY CONDITIONS WILL CONTINUE...BUT THE DEEP MOISTURE
FROM THIS SYSTEM IS EXPECTED TO REMAIN TO OUR SOUTH.
THEREFORE...MOST AREAS WILL TURN OUT DRY. A FEW FLURRIES OR
PERHAPS A PERIOD OF LIGHT SNOW CANNOT BE RULED OUT ACROSS CENTRAL
VIRGINIA INTO THE POTOMAC HIGHLANDS...BUT LITTLE OR NO SNOW
ACCUMULATION IS EXPECTED.

MULTIPLE ROUNDS OF ENERGY WILL PASS OVER THE MID-ATLANTIC THROUGH
TONIGHT. DUE TO LITTLE FORCING AS THE JET STREAM IS FURTHER
SOUTH...DRY CONDITIONS ARE EXPECTED THROUGH TONIGHT. SUBSIDENCE
BEHIND ANY VORT MAXES MAY LEAD TO SOME CLEARING. FCST MIN TEMPS
SHOULD BE IN THE UPPER 20S TO LOW 30S IN URBAN AREAS. CLEARING MAY
RESULT IN TEMPS DROPPING A FEW MORE DEGREES.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
HIGH PRESSURE EXTENDS FROM NEW ENGLAND DOWN INTO THE MID-ATLANTIC
SUNDAY. MODELS SUGGEST A GOOD DEAL OF SUNSHINE WITH MAXIMA NEAR
CLIMO.

HIGH PRESSURE EDGES A LITTLE EAST SUNDAY NIGHT INTO MONDAY...WITH
PRESSURE PATTERN SIGNALING SOME SEMBLANCE OF A WEDGE. AT THE SAME
TIME...SOUTHERN STREAM SHORTWAVE ENERGY IS ALSO FORECAST TO MOVE
NORTHEAST ON MONDAY.

RESULT WILL BE INCREASING/THICKENING CLOUDS SUNDAY NIGHT BUT THINK
ANY PRECIP WILL REMAIN TO THE SOUTH THROUGH DAYBREAK. TREND OF THE
MODELS IS TO DELAY PRECIP A LITTLE LONGER DURING THE DAY MONDAY.
LEANED TOWARD ECMWF/SREFS FOR TIMING. BUT IF PRECIP ARRIVES EARLY
ENOUGH...MONDAY MORNING MAY SEE A WINTRY MIX OF PRECIP PARTICULARLY
BLUE RIDGE WESTWARD. BULK OF THE PRECIP MONDAY AFTERNOON/EVENING
APPEARS TO BE RAIN BUT A WINTRY MIX INCLUDING POTENTIAL ICING FROM
FREEZING RAIN MAY LINGER ACROSS THE HIGHER ELEVATIONS OF THE POTOMAC
HIGHLANDS INTO MONDAY EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
SHORTWAVE EXITS LATE MONDAY NIGHT...BUT THE WEDGE REMAINS INTO
TUESDAY AND WITH LOW LEVEL MOISTURE IN PLACE CHANCE OF RAIN OR
DRIZZLE CONTINUES.

ATTENTION THEN TURNS TO A DEEP/STRONG UPPER LEVEL TROUGH SENDING
A COLD FRONT THROUGH LATE WEDNESDAY. DECENT LOW LEVEL JET AND
PLUME OF MOISTURE ARE EXPECTED TO BE TRANSPORTED AHEAD OF THE
FRONT ON WEDNESDAY...LEADING TO SHOWERS. MAXIMA ARE EXPECTED TO
BE WARM FOR THIS TIME OF YEAR AND HAVE TRENDED MAXIMA NEAR 60 EAST
OF THE BLUE RIDGE FOR WEDNESDAY.

DYNAMIC SYSTEM MOVES AWAY WEDNESDAY NIGHT. TIGHT GRADIENT AND COLD
ADVECTION BRING A WINDY AND COOLER CHRISTMAS DAY...ALTHOUGH MAXIMA
MAY ACTUALLY STILL BE A FEW DEGREES ABOVE CLIMO.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED THROUGH TONIGHT. HIGH AND MID-LEVEL CLOUDS
ARE EXPECTED DURING THIS TIME. A FEW FLURRIES CANNOT BE RULED OUT
TODAY...BUT MOST LOCATIONS WILL BE DRY. WINDS WILL BE
LIGHT...GENERALLY AROUND 5 KNOTS OR LESS. HIGH PRESSURE WILL
CONTROL THE WEATHER PATTERN FOR SUNDAY WITH VFR CONDITIONS AND
LIGHT WINDS.

DEVELOPING WEDGE AND AREA OF LOW PRESSURE WILL LIKELY BRING SOME
RAIN AND AT LEAST MVFR CONDITIONS MONDAY. IF PRECIP ARRIVES EARLY
ENOUGH MONDAY MORNING...IT MAY BEGIN AS A MIX.

IFR OR LOWER CONDITIONS ARE THEN EXPECTED MONDAY NIGHT INTO TUESDAY
WITH WEDGE IN PLACE AND AREAS OF RAIN OR DRIZZLE. STRONG COLD FRONT
FOLLOWS LATE WEDNESDAY WITH SHOWERS/POSSIBLY GUSTY WINDS.

&&

.MARINE...
HIGH PRESSURE WILL PERSIST ACROSS THE WATERS TODAY AND TONIGHT. NW
WINDS 5-10KTS ARE EXPECTED ON THE WATERS TODAY AND WEAKEN FURTHER
INTO TONIGHT.

HIGH PRESSURE OVER NEW ENGLAND ON SUNDAY MOVES OFFSHORE EARLY IN THE
WEEK. SCA CONDITIONS ARE POSSIBLE IN SOUTHERLY FLOW AHEAD OF A COLD
FRONT ON WEDNESDAY...THEN BEHIND THE FRONT FOR WEDNESDAY NIGHT AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BPP/HAS
NEAR TERM...BJL/HAS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...BJL/BPP/HAS
MARINE...BPP/HAS







000
FXUS61 KLWX 201421
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
921 AM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST THROUGH SUNDAY. LOW PRESSURE WILL
TRACK UP THE MID-ATLANTIC COAST LATE MONDAY. A STRONG COLD FRONT
WILL THEN PASS THROUGH THE AREA LATE WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
A SHORTWAVE WILL PASS THROUGH THE REGION TODAY...CAUSING HIGH AND
MID-LEVEL CLOUDS WHILE SURFACE HIGH PRESSURE BUILDS OVERHEAD.
SEASONABLY CHILLY CONDITIONS WILL CONTINUE...BUT THE DEEP MOISTURE
FROM THIS SYSTEM IS EXPECTED TO REMAIN TO OUR SOUTH.
THEREFORE...MOST AREAS WILL TURN OUT DRY. A FEW FLURRIES OR
PERHAPS A PERIOD OF LIGHT SNOW CANNOT BE RULED OUT ACROSS CENTRAL
VIRGINIA INTO THE POTOMAC HIGHLANDS...BUT LITTLE OR NO SNOW
ACCUMULATION IS EXPECTED.

MULTIPLE ROUNDS OF ENERGY WILL PASS OVER THE MID-ATLANTIC THROUGH
TONIGHT. DUE TO LITTLE FORCING AS THE JET STREAM IS FURTHER
SOUTH...DRY CONDITIONS ARE EXPECTED THROUGH TONIGHT. SUBSIDENCE
BEHIND ANY VORT MAXES MAY LEAD TO SOME CLEARING. FCST MIN TEMPS
SHOULD BE IN THE UPPER 20S TO LOW 30S IN URBAN AREAS. CLEARING MAY
RESULT IN TEMPS DROPPING A FEW MORE DEGREES.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
HIGH PRESSURE EXTENDS FROM NEW ENGLAND DOWN INTO THE MID-ATLANTIC
SUNDAY. MODELS SUGGEST A GOOD DEAL OF SUNSHINE WITH MAXIMA NEAR
CLIMO.

HIGH PRESSURE EDGES A LITTLE EAST SUNDAY NIGHT INTO MONDAY...WITH
PRESSURE PATTERN SIGNALING SOME SEMBLANCE OF A WEDGE. AT THE SAME
TIME...SOUTHERN STREAM SHORTWAVE ENERGY IS ALSO FORECAST TO MOVE
NORTHEAST ON MONDAY.

RESULT WILL BE INCREASING/THICKENING CLOUDS SUNDAY NIGHT BUT THINK
ANY PRECIP WILL REMAIN TO THE SOUTH THROUGH DAYBREAK. TREND OF THE
MODELS IS TO DELAY PRECIP A LITTLE LONGER DURING THE DAY MONDAY.
LEANED TOWARD ECMWF/SREFS FOR TIMING. BUT IF PRECIP ARRIVES EARLY
ENOUGH...MONDAY MORNING MAY SEE A WINTRY MIX OF PRECIP PARTICULARLY
BLUE RIDGE WESTWARD. BULK OF THE PRECIP MONDAY AFTERNOON/EVENING
APPEARS TO BE RAIN BUT A WINTRY MIX INCLUDING POTENTIAL ICING FROM
FREEZING RAIN MAY LINGER ACROSS THE HIGHER ELEVATIONS OF THE POTOMAC
HIGHLANDS INTO MONDAY EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
SHORTWAVE EXITS LATE MONDAY NIGHT...BUT THE WEDGE REMAINS INTO
TUESDAY AND WITH LOW LEVEL MOISTURE IN PLACE CHANCE OF RAIN OR
DRIZZLE CONTINUES.

ATTENTION THEN TURNS TO A DEEP/STRONG UPPER LEVEL TROUGH SENDING
A COLD FRONT THROUGH LATE WEDNESDAY. DECENT LOW LEVEL JET AND
PLUME OF MOISTURE ARE EXPECTED TO BE TRANSPORTED AHEAD OF THE
FRONT ON WEDNESDAY...LEADING TO SHOWERS. MAXIMA ARE EXPECTED TO
BE WARM FOR THIS TIME OF YEAR AND HAVE TRENDED MAXIMA NEAR 60 EAST
OF THE BLUE RIDGE FOR WEDNESDAY.

DYNAMIC SYSTEM MOVES AWAY WEDNESDAY NIGHT. TIGHT GRADIENT AND COLD
ADVECTION BRING A WINDY AND COOLER CHRISTMAS DAY...ALTHOUGH MAXIMA
MAY ACTUALLY STILL BE A FEW DEGREES ABOVE CLIMO.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED THROUGH TONIGHT. HIGH AND MID-LEVEL CLOUDS
ARE EXPECTED DURING THIS TIME. A FEW FLURRIES CANNOT BE RULED OUT
TODAY...BUT MOST LOCATIONS WILL BE DRY. WINDS WILL BE
LIGHT...GENERALLY AROUND 5 KNOTS OR LESS. HIGH PRESSURE WILL
CONTROL THE WEATHER PATTERN FOR SUNDAY WITH VFR CONDITIONS AND
LIGHT WINDS.

DEVELOPING WEDGE AND AREA OF LOW PRESSURE WILL LIKELY BRING SOME
RAIN AND AT LEAST MVFR CONDITIONS MONDAY. IF PRECIP ARRIVES EARLY
ENOUGH MONDAY MORNING...IT MAY BEGIN AS A MIX.

IFR OR LOWER CONDITIONS ARE THEN EXPECTED MONDAY NIGHT INTO TUESDAY
WITH WEDGE IN PLACE AND AREAS OF RAIN OR DRIZZLE. STRONG COLD FRONT
FOLLOWS LATE WEDNESDAY WITH SHOWERS/POSSIBLY GUSTY WINDS.

&&

.MARINE...
HIGH PRESSURE WILL PERSIST ACROSS THE WATERS TODAY AND TONIGHT. NW
WINDS 5-10KTS ARE EXPECTED ON THE WATERS TODAY AND WEAKEN FURTHER
INTO TONIGHT.

HIGH PRESSURE OVER NEW ENGLAND ON SUNDAY MOVES OFFSHORE EARLY IN THE
WEEK. SCA CONDITIONS ARE POSSIBLE IN SOUTHERLY FLOW AHEAD OF A COLD
FRONT ON WEDNESDAY...THEN BEHIND THE FRONT FOR WEDNESDAY NIGHT AND
THURSDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...BPP/HAS
NEAR TERM...BJL/HAS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...BJL/BPP/HAS
MARINE...BPP/HAS







000
FXUS61 KAKQ 201206
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
706 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST THROUGH TONIGHT. HIGH PRESSURE WILL BE OVER
THE AREA AGAIN DURING SUNDAY. ANOTHER LOW PRESSURE AREA MOVES
NORTHEAST OUT OF THE GULF OF MEXICO AND UP ALONG THE CAROLINA COAST
LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
SFC HIGH PRESSURE OVER THE MID-ATLANTIC TODAY KEEPS DEEPER
MOISTURE FROM THE GULF SHUNTED TO OUR SOUTH AS MID LEVEL FLOW
REMAINS FAIRLY ZONAL. LATEST RADAR MOSAIC NOT SHOWING MUCH IN THE
WAY OF PCPN MAKING IT ANY FARTHER NORTH THAN THE NC/SC BORDER
EARLY THIS MORNING...AND LATEST SFC OBS CONFIRM THAT.
THEREFORE...WILL KEEP FORECAST DRY THROUGH 12Z. 00Z SUITE OF MODELS
TRY TO BRING SOME LIGHT PCPN INTO FAR SOUTHERN PORTIONS OF OUR CWA
LATER THIS MORNING INTO THE AFTERNOON. HOWEVER...MODELS HAVE
CONTINUED TO TREND DRIER SINCE YESTERDAY...AND WILL LIMIT POPS TO
NO MORE THAN 30% ACROSS NE NC THIS AFTN. GENERALLY EXPECTING DRY
WX NORTH OF HWY 58 IN VIRGINIA. WITH TEMPS AT OR BELOW FREEZING
ACROSS THE PIEDMONT THIS MORNING...AN PCPN THAT FALLS NEAR THE NC
BORDER PRIOR TO 15Z COULD BE IN THE FORM OF A SNOW SHOWER OR SLEET
PELLETS WITH NO ACCUMULATION. CLOUDY TO MOSTLY CLOUDY TODAY WITH
HIGHS IN THE UPR 30S NW TO MID 40S SE.

SFC HIGH PRESSURE REBOUNDS TONIGHT WITH DECREASING CLOUDS. LOWS IN
THE MID 20S NORTH TO THE LOW 30S SOUTH.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
HIGH PRESSURE REMAINS ENTRENCHED OVER THE MID-ATLANTIC SUNDAY WITH
A MIX OF SUN AND CLOUDS. SEASONABLE HIGHS OF 45-50.

NEXT SYSTEM...THIS ONE MORE AMPLIFIED WILL AFFECT THE AREA ON
MON...WITH LIKELY TO CATEGORICAL POPS ALL ZONES MON AM/MON AFTN.
LOOKS LIKE ALL RAIN ASIDE FROM A BRIEF MIX POSSIBLE AT ONSET IN
FAR NW COUNTIES. AT THIS POINT...IT DOES NOT APPEAR ENOUGH FROZEN
PCPN WOULD OCCUR TO CAUSE ANY CONCERNS. LOWS SUNDAY NIGHT FROM
AROUND 30 NW TO AROUND 40 VA BEACH. HIGHS MON ONLY AROUND 40 NW
TO THE MID 50S FAR SE IN CAD SETUP.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
LOW PRESSURE LIFTS TO THE NE MONDAY NIGHT WITH POPS SLOWLY DIMINISHING
FROM SW-NE OVERNIGHT. MID-LEVEL RIDGING BRIEFLY BUILDS INTO THE
REGION TUESDAY. HOWEVER...MOIST SOUTHERLY FLOW ORIGINATING FROM
THE GULF STREAM WILL PREVAIL SO LOW CHC (30%) POPS WILL BE
MAINTAINED. A VERY DYNAMIC SYSTEM LIFTS NNE WEST OF THE
APPALACHIANS TUESDAY NIGHT WITH THE ATTENDANT COLD FRONT CROSSING
THE MID-ATLANTIC WEDNESDAY. THE FIRST POTENTIAL OF RAIN ARRIVES
TUESDAY NIGHT ASSOCIATED WITH MOIST WAA. THE SECOND POTENTIAL WILL
BE WEDNESDAY AHEAD OF THE COLD FRONT. THERE IS A POTENTIAL FOR
THUNDER WEDNESDAY AS SURFACE DEWPOINTS POTENTIALLY EXCEED 60F
(ESPECIALLY OVER THE COASTAL PLAIN). THE PATTERN DOES SUPPORT THE
POSSIBILITY OF A DYNAMICALLY FORCED LINE OF CONVECTION CONTAINING
STRONG WIND GUSTS AS CURRENT FORECAST GUIDANCE SUGGESTS A
925-700MB WIND FIELD AVERAGING 40-50KT. THIS WOULD BE A
CLIMATOLOGICALLY RARITY THIS TIME OF YEAR...SO CONFIDENCE IS ON
THE LOW-SIDE GIVEN THAT THIS IS 5-6 DAYS OUT. TEMPERATURES WILL BE
VERY MILD AHEAD OF THE FRONT TUESDAY AND WEDNESDAY...WITH HIGHS
AVERAGING FROM THE MID 50S NW...TO MID/UPPER 60S SE. DRY AND
BREEZY CONDITIONS WILL LIKELY PREVAIL BY CHRISTMAS DAY...WITH HIGH
TEMPERATURES OF 50-55. THE FLOW BECOMES MORE SW BY FRIDAY WITH
CURRENT FORECAST HIGHS OF 55-60...BUT 60-65 IS POSSIBLE BASED ON
LOW-LEVEL THICKNESS FIELDS.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDS IN PLACE ACROSS THE REGION THIS MORNING, WITH
PREDOMINATELY VFR CONDS TO PERSIST THROUGH THE TAF PERIOD. HIGH
PRESSURE WILL CONTINUE TO RIDGE SOUTH ACROSS THE REGION FROM THE
EASTERN GREAT LAKES/NORTHEAST THROUGH THE TAF PERIOD, AS AN UPPER
LEVEL DISTURBANCE MOVES ACROSS THE SOUTHEAST TOWARD THE CAROLINAS
TODAY, WHILE ASSOCIATED WEAK SFC LOW MOVES ACROSS THE SOUTHEAST
TODAY AND TONIGHT. EAST FLOW WILL ALLOW FOR LOWERING CIGS THROUGH
THE MORNING, WITH OVC AT 5-8 KFT AGL EXPECTED THROUGH AFTN.
FORCING WILL BE ENOUGH FOR SOME SPOTTY LIGHT RAIN SHRAS, MAINLY IN
FAR SRN PORTIONS OF THE AREA. PERIODIC MVFR CIGS WILL BE POSSIBLE
ACROSS PHF/ORF/ECG AFTER 18Z. HOWEVER, RAIN SHOULD BE LIGHT ENOUGH
TO PRECLUDE ANY VSBY RESTRICTIONS. HV GONE WITH PREDOMINATE SHRA
AT ECG THIS AFTN, WITH VICINITY WORDING AT ORF/PHF/RIC.

OUTLOOK...ANY PRECIP COMES TO AN END EARLY SATURDAY EVENING AND
CONDITIONS WILL GRADUALLY IMPROVE FROM WEST TO EAST THROUGH THE REST
OF SAT NIGHT. HIGH PRESSURE BUILDS TO THE NORTH OF THE AREA SUNDAY.
A SERIES OF LOW PRESSURE SYSTEMS AND COMPLEX FRONTAL BOUNDARIES WILL
BRING CHANCES FOR RAIN AND PERIODS OF LOW CEILINGS AND VISIBILITIES
BEGINNING MONDAY.

&&

.MARINE...
LATEST OBS HIGH PRESSURE SPREADS EAST ACROSS NEW ENGLAND THROUGH
TONIGHT, RIDGING SOUTH INTO THE AREA TODAY. MEANWHILE, WEAK SFC LOW
PRESSURE WILL PASS SOUTH OF THE REGION LATER TODAY AND TONIGHT. THIS
WILL MAINTAIN LIGHT NORTHERLY FLOW ~10 KT OVER THE MARINE AREA
TODAY. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY NIGHT, AS LOW
PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY NIGHT BEFORE
TRACKING NE OFF THE LOWER MID ATLANTIC COAST LATER MONDAY AND MONDAY
NIGHT. THE RESULTANT TIGHTENING SURFACE PRESSURE GRADIENT WILL ALLOW
ONSHORE (EAST) FLOW TO GRADUALLY INCREASE MONDAY AFTN, GRADUALLY
BUILDING SEAS MONDAY NIGHT AND EARLY TUESDAY. 15-20KT EASTERLY FLOW
OVER THE OCEAN AND LOWER BAY COULD PRODUCE A PERIOD OF SCA
CONDITIONS ESPECIALLY OVER THE SRN OCEAN ZONES (MAINLY FOR SEAS) AND
LOWER BAY/MOUTH OF JAMES. THERE IS NO CAA IN THE WAKE OF THIS
LOW...SO SUB-SCA CONDITIONS SHOULD PREVAIL BEHIND THE SYSTEM LATER
MONDAY NIGHT INTO TUESDAY.

A STRONG LOW PRESSURE SYSTEM LOOKS TO DEVELOP ACROSS THE OHIO
VALLEY, TRACKING WEST OF THE MOUNTAINS TUESDAY NIGHT. HOWEVER, THIS
SYSTEM WILL PUSH A STRONG COLD FRONT ACROSS THE MID ATLANTIC COAST
LATER WEDNESDAY. SCA CONDITIONS ARE LIKELY WEDNESDAY NIGHT INTO
CHRISTMAS DAY AS HIGH PRESSURE BUILDS IN FROM THE WNW.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...JDM
NEAR TERM...JDM
SHORT TERM...JDM/LKB
LONG TERM...AJZ/MAS
AVIATION...MAM
MARINE...MAM







000
FXUS61 KPBZ 201154
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
654 AM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

THE CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE. NO UPDATES WILL BE
NEEDED EARLY THIS MORNING. PREV DISCUSSION FOLLOWS..

WEAK RIDGE BREAKS DOWN
LATER TODAY AS SHORTWAVE TROUGH WILL MOVE THROUGH THE UPPER
MIDWEST. WEAK CAA IS EXPECTED WITH THIS FEATURE WHICH WILL HELP TO
MAINTAIN CLOUD COVER.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
SHORTWAVE TROUGH WILL SWING THROUGH TONIGHT. PRECIP IS NOT
EXPECTED...BUT AGAIN CLOUD COVER WILL BE MAINTAINED WITH THE UPPER
LEVEL SYSTEM.

MODELS ARE SHOWING SOME IMPROVEMENT SUNDAY...PARTICULARLY OVER THE
WEST AND FAR SOUTH. HOWEVER...MODEL SOUNDINGS FOR THE REST OF THE
REGION STILL WANT TO MAINTAIN A SATURATED LAYER AROUND 2500FT FOR
MOST OF THE DAY...WHICH DOES NOT PRESENT MUCH HOPE FOR SUNSHINE.
CLOUDS WILL BE TRICKY ON SUNDAY...TRYING TO DETERMINE HOW MUCH OF
THE CLOUD DECK WILL BE ERODED.

SPLIT FLOW DEVELOPS ON MONDAY WITH A LARGE SYSTEM TO THE WEST AND
ANOTHER SYSTEM TO THE SOUTH-SOUTHEAST. IT APPEARS THAT THE AREA
WILL LIE IN BETWEEN LIMITING THE CHANCES FOR PRECIPITATION. WAA
WILL CONTINUE ON MONDAY AND LOW-LEVEL MOISTURE INCREASES ONCE
AGAIN. LOOKS LIKE A GOOD DEAL OF CLOUD COVER AGAIN MONDAY. A WEAK
AND UNORGANIZED SHORTWAVE TROUGH WILL SWING THROUGH MONDAY...
ALLOWING FOR THE POSSIBILITY OF SOME LIGHT PRECIP...MAINLY OVER
THE SOUTHERN RIDGES. THIS WILL NEED TO BE FINE TUNED AS THE WARMER
AIR ALOFT MAY OCCUR BEFORE SURFACE TEMPS RESPOND. CONFIDENCE IS
LOW THAT ANY PRECIP WILL OCCUR...SO FOR FORECAST WILL LEAVE OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
STILL SEEING SOME MINOR DIFFERENCES IN MEDIUM RANGE MODEL
SOLUTIONS FOR MIDWEEK SYSTEM. THINK MUCH OF TUESDAY COULD BE DRY
OR JUST LIGHT SHOWERS AS AREA WILL BE WELL INTO THE WARM SECTOR. RAIN
WILL OVERSPREAD THE AREA TUESDAY NIGHT AHEAD OF OCCLUDED FRONT AND
CONTINUE THROUGH WEDNESDAY. COLDER AIR WILL MOVE IN LATER
WEDNESDAY NIGHT CHANGING ANY LINGERING SHOWERS TO SNOW SHOWERS.
COULD SEE A BRIEF UPTICK IN SNOW SHOWER COVERAGE EARLY THURSDAY
MORNING AS MAIN TROUGH SWINGS THROUGH. COLD AIR WILL BE IN PLACE
THURSDAY...BUT WIND DIRECTION NOT OPTIMAL FOR LAKE INFLUENCED SNOW
SHOWERS.

WARMER AIR WILL MOVE BACK IN THURSDAY NIGHT AND FRIDAY.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
LOW LEVEL MOISTURE WILL REMAIN TRAPPED UNDER A STRONG INVERSION
AOB 4KFT AS LOW LEVEL WINDS BECOME LIGHT....MAINTAINING HIGH MVFR
TO LOW VFR CONDITIONS OVER THE NEXT 24 HOURS. PRECIPITATION
CHANCES ARE MINIMAL GIVEN THE SHALLOW DEPTH OF THE SATURATED
LAYER AND ABSENCE OF ANY LIFT.

OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST THROUGH THE WEEKEND. NEXT STORM
SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND RESULT IN
WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF LLWS
THROUGH WEDNESDAY.

&&

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

&&

$$






000
FXUS61 KPBZ 201154
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
654 AM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

THE CURRENT FORECAST LOOKS TO BE IN GOOD SHAPE. NO UPDATES WILL BE
NEEDED EARLY THIS MORNING. PREV DISCUSSION FOLLOWS..

WEAK RIDGE BREAKS DOWN
LATER TODAY AS SHORTWAVE TROUGH WILL MOVE THROUGH THE UPPER
MIDWEST. WEAK CAA IS EXPECTED WITH THIS FEATURE WHICH WILL HELP TO
MAINTAIN CLOUD COVER.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
SHORTWAVE TROUGH WILL SWING THROUGH TONIGHT. PRECIP IS NOT
EXPECTED...BUT AGAIN CLOUD COVER WILL BE MAINTAINED WITH THE UPPER
LEVEL SYSTEM.

MODELS ARE SHOWING SOME IMPROVEMENT SUNDAY...PARTICULARLY OVER THE
WEST AND FAR SOUTH. HOWEVER...MODEL SOUNDINGS FOR THE REST OF THE
REGION STILL WANT TO MAINTAIN A SATURATED LAYER AROUND 2500FT FOR
MOST OF THE DAY...WHICH DOES NOT PRESENT MUCH HOPE FOR SUNSHINE.
CLOUDS WILL BE TRICKY ON SUNDAY...TRYING TO DETERMINE HOW MUCH OF
THE CLOUD DECK WILL BE ERODED.

SPLIT FLOW DEVELOPS ON MONDAY WITH A LARGE SYSTEM TO THE WEST AND
ANOTHER SYSTEM TO THE SOUTH-SOUTHEAST. IT APPEARS THAT THE AREA
WILL LIE IN BETWEEN LIMITING THE CHANCES FOR PRECIPITATION. WAA
WILL CONTINUE ON MONDAY AND LOW-LEVEL MOISTURE INCREASES ONCE
AGAIN. LOOKS LIKE A GOOD DEAL OF CLOUD COVER AGAIN MONDAY. A WEAK
AND UNORGANIZED SHORTWAVE TROUGH WILL SWING THROUGH MONDAY...
ALLOWING FOR THE POSSIBILITY OF SOME LIGHT PRECIP...MAINLY OVER
THE SOUTHERN RIDGES. THIS WILL NEED TO BE FINE TUNED AS THE WARMER
AIR ALOFT MAY OCCUR BEFORE SURFACE TEMPS RESPOND. CONFIDENCE IS
LOW THAT ANY PRECIP WILL OCCUR...SO FOR FORECAST WILL LEAVE OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
STILL SEEING SOME MINOR DIFFERENCES IN MEDIUM RANGE MODEL
SOLUTIONS FOR MIDWEEK SYSTEM. THINK MUCH OF TUESDAY COULD BE DRY
OR JUST LIGHT SHOWERS AS AREA WILL BE WELL INTO THE WARM SECTOR. RAIN
WILL OVERSPREAD THE AREA TUESDAY NIGHT AHEAD OF OCCLUDED FRONT AND
CONTINUE THROUGH WEDNESDAY. COLDER AIR WILL MOVE IN LATER
WEDNESDAY NIGHT CHANGING ANY LINGERING SHOWERS TO SNOW SHOWERS.
COULD SEE A BRIEF UPTICK IN SNOW SHOWER COVERAGE EARLY THURSDAY
MORNING AS MAIN TROUGH SWINGS THROUGH. COLD AIR WILL BE IN PLACE
THURSDAY...BUT WIND DIRECTION NOT OPTIMAL FOR LAKE INFLUENCED SNOW
SHOWERS.

WARMER AIR WILL MOVE BACK IN THURSDAY NIGHT AND FRIDAY.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
LOW LEVEL MOISTURE WILL REMAIN TRAPPED UNDER A STRONG INVERSION
AOB 4KFT AS LOW LEVEL WINDS BECOME LIGHT....MAINTAINING HIGH MVFR
TO LOW VFR CONDITIONS OVER THE NEXT 24 HOURS. PRECIPITATION
CHANCES ARE MINIMAL GIVEN THE SHALLOW DEPTH OF THE SATURATED
LAYER AND ABSENCE OF ANY LIFT.

OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST THROUGH THE WEEKEND. NEXT STORM
SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND RESULT IN
WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF LLWS
THROUGH WEDNESDAY.

&&

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

&&

$$







000
FXUS61 KPBZ 200909
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
409 AM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK RIDGE BREAKS DOWN LATER TODAY AS SHORTWAVE TROUGH WILL MOVE
THROUGH THE UPPER MIDWEST. WEAK CAA IS EXPECTED WITH THIS FEATURE
WHICH WILL HELP TO MAINTAIN CLOUD COVER.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
SHORTWAVE TROUGH WILL SWING THROUGH TONIGHT. PRECIP IS NOT
EXPECTED...BUT AGAIN CLOUD COVER WILL BE MAINTAINED WITH THE UPPER
LEVEL SYSTEM.

MODELS ARE SHOWING SOME IMPROVEMENT SUNDAY...PARTICULARLY OVER THE
WEST AND FAR SOUTH. HOWEVER...MODEL SOUNDINGS FOR THE REST OF THE
REGION STILL WANT TO MAINTAIN A SATURATED LAYER AROUND 2500FT FOR
MOST OF THE DAY...WHICH DOES NOT PRESENT MUCH HOPE FOR SUNSHINE.
CLOUDS WILL BE TRICKY ON SUNDAY...TRYING TO DETERMINE HOW MUCH OF
THE STRAOCU DECK WILL BE ERODED.

SPLIT FLOW DEVELOPS ON MONDAY WITH A LARGE SYSTEM TO THE WEST AND
ANOTHER SYSTEM TO THE SOUTH-SOUTHEAST. IT APPEARS THAT THE AREA
WILL LIE IN BETWEEN LIMITING THE CHANCES FOR PRECIPITATION. WAA
WILL CONTINUE ON MONDAY AND LOW-LEVEL MOISTURE INCREASES ONCE
AGAIN. LOOKS LIKE A GOOD DEAL OF CLOUD COVER AGAIN MONDAY. A WEAK
AND UNORGANIZED SHORTWAVE TROUGH WILL SWING THROUGH MONDAY...
ALLOWING FOR THE POSSIBILITY OF SOME LIGHT PRECIP...MAINLY OVER
THE SOUTHERN RIDGES. THIS WILL NEED TO BE FINE TUNED AS THE WARMER
AIR ALOFT MAY OCCUR BEFORE SURFACE TEMPS RESPOND. CONFIDENCE IS
LOW THAT ANY PRECIP WILL OCCUR...SO FOR FORECAST WILL LEAVE OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
STILL SEEING SOME MINOR DIFFERENCES IN MEDIUM RANGE MODEL
SOLUTIONS FOR MIDWEEK SYSTEM. THINK MUCH OF TUESDAY COULD BE DRY
OR JUST LIGHT SHOWERS AS AREA WILL BE WELL INTO THE WARM SECTOR. RAIN
WILL OVERSPREAD THE AREA TUESDAY NIGHT AHEAD OF OCCLUDED FRONT AND
CONTINUE THROUGH WEDNESDAY. COLDER AIR WILL MOVE IN LATER
WEDNESDAY NIGHT CHANGING ANY LINGERING SHOWERS TO SNOW SHOWERS.
COULD SEE A BRIEF UPTICK IN SNOW SHOWER COVERAGE EARLY THURSDAY
MORNING AS MAIN TROUGH SWINGS THROUGH. COLD AIR WILL BE IN PLACE
THURSDAY...BUT WIND DIRECTION NOT OPTIMAL FOR LAKE INFLUENCED SNOW
SHOWERS.

WARMER AIR WILL MOVE BACK IN THURSDAY NIGHT AND FRIDAY.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
LOW LEVEL MOISTURE WILL REMAIN TRAPPED UNDER A STRONG INVERSION
AOB 4KFT AS LOW LEVEL WINDS BECOME LIGHT....MAINTAINING HIGH MVFR
TO LOW VFR CONDITIONS OVER THE NEXT 24 HOURS. PRECIPITATION
CHANCES ARE MINIMAL GIVEN THE SHALLOW DEPTH OF THE SATURATED
LAYER AND ABSENCE OF ANY LIFT.

OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST THROUGH THE WEEKEND. NEXT STORM
SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND RESULT IN
WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF LLWS
THROUGH WEDNESDAY.

&&

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

&&

$$







000
FXUS61 KPBZ 200909
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
409 AM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WEAK RIDGE BREAKS DOWN LATER TODAY AS SHORTWAVE TROUGH WILL MOVE
THROUGH THE UPPER MIDWEST. WEAK CAA IS EXPECTED WITH THIS FEATURE
WHICH WILL HELP TO MAINTAIN CLOUD COVER.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
SHORTWAVE TROUGH WILL SWING THROUGH TONIGHT. PRECIP IS NOT
EXPECTED...BUT AGAIN CLOUD COVER WILL BE MAINTAINED WITH THE UPPER
LEVEL SYSTEM.

MODELS ARE SHOWING SOME IMPROVEMENT SUNDAY...PARTICULARLY OVER THE
WEST AND FAR SOUTH. HOWEVER...MODEL SOUNDINGS FOR THE REST OF THE
REGION STILL WANT TO MAINTAIN A SATURATED LAYER AROUND 2500FT FOR
MOST OF THE DAY...WHICH DOES NOT PRESENT MUCH HOPE FOR SUNSHINE.
CLOUDS WILL BE TRICKY ON SUNDAY...TRYING TO DETERMINE HOW MUCH OF
THE STRAOCU DECK WILL BE ERODED.

SPLIT FLOW DEVELOPS ON MONDAY WITH A LARGE SYSTEM TO THE WEST AND
ANOTHER SYSTEM TO THE SOUTH-SOUTHEAST. IT APPEARS THAT THE AREA
WILL LIE IN BETWEEN LIMITING THE CHANCES FOR PRECIPITATION. WAA
WILL CONTINUE ON MONDAY AND LOW-LEVEL MOISTURE INCREASES ONCE
AGAIN. LOOKS LIKE A GOOD DEAL OF CLOUD COVER AGAIN MONDAY. A WEAK
AND UNORGANIZED SHORTWAVE TROUGH WILL SWING THROUGH MONDAY...
ALLOWING FOR THE POSSIBILITY OF SOME LIGHT PRECIP...MAINLY OVER
THE SOUTHERN RIDGES. THIS WILL NEED TO BE FINE TUNED AS THE WARMER
AIR ALOFT MAY OCCUR BEFORE SURFACE TEMPS RESPOND. CONFIDENCE IS
LOW THAT ANY PRECIP WILL OCCUR...SO FOR FORECAST WILL LEAVE OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
STILL SEEING SOME MINOR DIFFERENCES IN MEDIUM RANGE MODEL
SOLUTIONS FOR MIDWEEK SYSTEM. THINK MUCH OF TUESDAY COULD BE DRY
OR JUST LIGHT SHOWERS AS AREA WILL BE WELL INTO THE WARM SECTOR. RAIN
WILL OVERSPREAD THE AREA TUESDAY NIGHT AHEAD OF OCCLUDED FRONT AND
CONTINUE THROUGH WEDNESDAY. COLDER AIR WILL MOVE IN LATER
WEDNESDAY NIGHT CHANGING ANY LINGERING SHOWERS TO SNOW SHOWERS.
COULD SEE A BRIEF UPTICK IN SNOW SHOWER COVERAGE EARLY THURSDAY
MORNING AS MAIN TROUGH SWINGS THROUGH. COLD AIR WILL BE IN PLACE
THURSDAY...BUT WIND DIRECTION NOT OPTIMAL FOR LAKE INFLUENCED SNOW
SHOWERS.

WARMER AIR WILL MOVE BACK IN THURSDAY NIGHT AND FRIDAY.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
LOW LEVEL MOISTURE WILL REMAIN TRAPPED UNDER A STRONG INVERSION
AOB 4KFT AS LOW LEVEL WINDS BECOME LIGHT....MAINTAINING HIGH MVFR
TO LOW VFR CONDITIONS OVER THE NEXT 24 HOURS. PRECIPITATION
CHANCES ARE MINIMAL GIVEN THE SHALLOW DEPTH OF THE SATURATED
LAYER AND ABSENCE OF ANY LIFT.

OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST THROUGH THE WEEKEND. NEXT STORM
SYSTEM WILL BEGIN TO IMPACT THE REGION ON TUESDAY AND RESULT IN
WIDESPREAD RAIN...CIG/VIS RESTRICTIONS...AND PERIODS OF LLWS
THROUGH WEDNESDAY.

&&

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

&&

$$






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