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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





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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







  [top]

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





  [top]

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.

&&

$$






000
FXUS61 KPHI 200855
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
355 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/...
HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS EASTERN CANADA AND
NORTHERN NEW ENGLAND TODAY, WITH THE MID-ATLANTIC BEING ON THE
SOUTHERN FRINGE. THIS WILL KEEP A DRY, LIGHT NORTHERLY FLOW ACROSS
THE AREA. WITH PW VALUES BETWEEN ONE-QUARTER AND ONE-THIRD OF AN
INCH, NO PRECIPITATION IS FORECAST. HOWEVER, THERE WILL REMAIN
MOISTURE CAUGHT UP UNDERNEATH THE INVERSION WHICH SHOULD KEEP SOME
CLOUD COVER ACROSS THE AREA. EVEN IF THE LOWER LEVEL CLOUDS
SCATTER OUT DURING THE DAY, WE SHOULD SEE AN INCREASE IN HIGH
LEVEL CLOUDS AS A SHORT WAVE/VORTICITY MAX SLIDES ACROSS THE AREA.
THE NORTHERLY WIND, ALONG WITH ANY CLOUD COVER SHOULD PREVENT
TEMPERATURES FROM WARMING SIGNIFICANTLY TODAY, SO WE USED A BLEND
OF MAV/MET MOS AND MOSGUIDE WHICH WERE IN PRETTY GOOD AGREEMENT.

&&

.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 /09Z 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...ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/ROBERTSON
MARINE...IOVINO/ROBERTSON






000
FXUS61 KPHI 200855
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
355 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/...
HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS EASTERN CANADA AND
NORTHERN NEW ENGLAND TODAY, WITH THE MID-ATLANTIC BEING ON THE
SOUTHERN FRINGE. THIS WILL KEEP A DRY, LIGHT NORTHERLY FLOW ACROSS
THE AREA. WITH PW VALUES BETWEEN ONE-QUARTER AND ONE-THIRD OF AN
INCH, NO PRECIPITATION IS FORECAST. HOWEVER, THERE WILL REMAIN
MOISTURE CAUGHT UP UNDERNEATH THE INVERSION WHICH SHOULD KEEP SOME
CLOUD COVER ACROSS THE AREA. EVEN IF THE LOWER LEVEL CLOUDS
SCATTER OUT DURING THE DAY, WE SHOULD SEE AN INCREASE IN HIGH
LEVEL CLOUDS AS A SHORT WAVE/VORTICITY MAX SLIDES ACROSS THE AREA.
THE NORTHERLY WIND, ALONG WITH ANY CLOUD COVER SHOULD PREVENT
TEMPERATURES FROM WARMING SIGNIFICANTLY TODAY, SO WE USED A BLEND
OF MAV/MET MOS AND MOSGUIDE WHICH WERE IN PRETTY GOOD AGREEMENT.

&&

.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 /09Z 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...ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...IOVINO
AVIATION...IOVINO/ROBERTSON
MARINE...IOVINO/ROBERTSON







000
FXUS61 KLWX 200852
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
352 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/...
THE MID ATLANTIC IS BETWEEN TWO SHORTWAVE TROUGHS THIS MORNING...ONE
ACROSS NEW YORK AND ANOTHER APPROACHING FROM THE OHIO VALLEY. HIGH
PRESSURE IS CENTERED OVERHEAD AND HAS LED TO CALM AND DRY CONDITIONS
THIS MORNING.

MOISTURE ADVECTION FROM SW FLOW ALOFT WILL CONTINUE AHEAD OF THE
APPROACHING SHORTWAVE TROUGH AND CIRRUS WILL CONTINUE TO MOVE INTO
THE REGION FROM SW TO NE THIS MORNING. PRECIPITATION ACROSS THE SE
US WILL CONTINUE TO MOVE NORTH-NORTHEAST THIS MORNING. THERE IS A
SLIGHT CHANCE OF SNOW TO SKIM THE CENTRAL FOOTHILLS BEFORE NOON
TODAY AS MOISTURE MOVES NORTHWARD. IT IS NOT LIKELY AS SW FLOW ALOFT
IS EXPECTED TO BECOME WESTERLY MIDDAY LIMITING MOISTURE ADVECTION
INTO THE MID-ATLANTIC. MOST IF NOT ALL PRECIPITATION SHOULD STAY SOUTH
OF THE OUTLOOK AREA. CLOUDS AND LOW SUN ANGLE WILL LIMIT HEATING
TODAY AND TEMPS WILL ONLY CLIMB INTO THE UPPER 30S TO AROUND 40
TODAY.

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 /09Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED TODAY AND TONIGHT. CLOUDS WILL INCREASE FROM
SW TO NE ACROSS THE TERMINALS TODAY. MID-HIGH LEVEL CIGS EXPECTED.
-SN IS POSSIBLE BUT NOT LIKELY AT CHO THIS MORNING. NW WINDS
AROUND 5 KTS EXPECTED TODAY AND TONIGHT.

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...HAS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...BPP/HAS
MARINE...BPP/HAS








000
FXUS61 KLWX 200852
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
352 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/...
THE MID ATLANTIC IS BETWEEN TWO SHORTWAVE TROUGHS THIS MORNING...ONE
ACROSS NEW YORK AND ANOTHER APPROACHING FROM THE OHIO VALLEY. HIGH
PRESSURE IS CENTERED OVERHEAD AND HAS LED TO CALM AND DRY CONDITIONS
THIS MORNING.

MOISTURE ADVECTION FROM SW FLOW ALOFT WILL CONTINUE AHEAD OF THE
APPROACHING SHORTWAVE TROUGH AND CIRRUS WILL CONTINUE TO MOVE INTO
THE REGION FROM SW TO NE THIS MORNING. PRECIPITATION ACROSS THE SE
US WILL CONTINUE TO MOVE NORTH-NORTHEAST THIS MORNING. THERE IS A
SLIGHT CHANCE OF SNOW TO SKIM THE CENTRAL FOOTHILLS BEFORE NOON
TODAY AS MOISTURE MOVES NORTHWARD. IT IS NOT LIKELY AS SW FLOW ALOFT
IS EXPECTED TO BECOME WESTERLY MIDDAY LIMITING MOISTURE ADVECTION
INTO THE MID-ATLANTIC. MOST IF NOT ALL PRECIPITATION SHOULD STAY SOUTH
OF THE OUTLOOK AREA. CLOUDS AND LOW SUN ANGLE WILL LIMIT HEATING
TODAY AND TEMPS WILL ONLY CLIMB INTO THE UPPER 30S TO AROUND 40
TODAY.

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 /09Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED TODAY AND TONIGHT. CLOUDS WILL INCREASE FROM
SW TO NE ACROSS THE TERMINALS TODAY. MID-HIGH LEVEL CIGS EXPECTED.
-SN IS POSSIBLE BUT NOT LIKELY AT CHO THIS MORNING. NW WINDS
AROUND 5 KTS EXPECTED TODAY AND TONIGHT.

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...HAS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...BPP/HAS
MARINE...BPP/HAS








000
FXUS61 KLWX 200852
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
352 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/...
THE MID ATLANTIC IS BETWEEN TWO SHORTWAVE TROUGHS THIS MORNING...ONE
ACROSS NEW YORK AND ANOTHER APPROACHING FROM THE OHIO VALLEY. HIGH
PRESSURE IS CENTERED OVERHEAD AND HAS LED TO CALM AND DRY CONDITIONS
THIS MORNING.

MOISTURE ADVECTION FROM SW FLOW ALOFT WILL CONTINUE AHEAD OF THE
APPROACHING SHORTWAVE TROUGH AND CIRRUS WILL CONTINUE TO MOVE INTO
THE REGION FROM SW TO NE THIS MORNING. PRECIPITATION ACROSS THE SE
US WILL CONTINUE TO MOVE NORTH-NORTHEAST THIS MORNING. THERE IS A
SLIGHT CHANCE OF SNOW TO SKIM THE CENTRAL FOOTHILLS BEFORE NOON
TODAY AS MOISTURE MOVES NORTHWARD. IT IS NOT LIKELY AS SW FLOW ALOFT
IS EXPECTED TO BECOME WESTERLY MIDDAY LIMITING MOISTURE ADVECTION
INTO THE MID-ATLANTIC. MOST IF NOT ALL PRECIPITATION SHOULD STAY SOUTH
OF THE OUTLOOK AREA. CLOUDS AND LOW SUN ANGLE WILL LIMIT HEATING
TODAY AND TEMPS WILL ONLY CLIMB INTO THE UPPER 30S TO AROUND 40
TODAY.

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 /09Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED TODAY AND TONIGHT. CLOUDS WILL INCREASE FROM
SW TO NE ACROSS THE TERMINALS TODAY. MID-HIGH LEVEL CIGS EXPECTED.
-SN IS POSSIBLE BUT NOT LIKELY AT CHO THIS MORNING. NW WINDS
AROUND 5 KTS EXPECTED TODAY AND TONIGHT.

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...HAS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...BPP/HAS
MARINE...BPP/HAS








000
FXUS61 KLWX 200852
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
352 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/...
THE MID ATLANTIC IS BETWEEN TWO SHORTWAVE TROUGHS THIS MORNING...ONE
ACROSS NEW YORK AND ANOTHER APPROACHING FROM THE OHIO VALLEY. HIGH
PRESSURE IS CENTERED OVERHEAD AND HAS LED TO CALM AND DRY CONDITIONS
THIS MORNING.

MOISTURE ADVECTION FROM SW FLOW ALOFT WILL CONTINUE AHEAD OF THE
APPROACHING SHORTWAVE TROUGH AND CIRRUS WILL CONTINUE TO MOVE INTO
THE REGION FROM SW TO NE THIS MORNING. PRECIPITATION ACROSS THE SE
US WILL CONTINUE TO MOVE NORTH-NORTHEAST THIS MORNING. THERE IS A
SLIGHT CHANCE OF SNOW TO SKIM THE CENTRAL FOOTHILLS BEFORE NOON
TODAY AS MOISTURE MOVES NORTHWARD. IT IS NOT LIKELY AS SW FLOW ALOFT
IS EXPECTED TO BECOME WESTERLY MIDDAY LIMITING MOISTURE ADVECTION
INTO THE MID-ATLANTIC. MOST IF NOT ALL PRECIPITATION SHOULD STAY SOUTH
OF THE OUTLOOK AREA. CLOUDS AND LOW SUN ANGLE WILL LIMIT HEATING
TODAY AND TEMPS WILL ONLY CLIMB INTO THE UPPER 30S TO AROUND 40
TODAY.

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 /09Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED TODAY AND TONIGHT. CLOUDS WILL INCREASE FROM
SW TO NE ACROSS THE TERMINALS TODAY. MID-HIGH LEVEL CIGS EXPECTED.
-SN IS POSSIBLE BUT NOT LIKELY AT CHO THIS MORNING. NW WINDS
AROUND 5 KTS EXPECTED TODAY AND TONIGHT.

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...HAS
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...BPP/HAS
MARINE...BPP/HAS








000
FXUS61 KAKQ 200845
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
345 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 /08Z 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.

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 200614
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
114 AM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
OVERNIGHT PERIOD IN GOOD SHAPE. STRATOCU REMAINS TRAPPED UNDER
WEAK RIDGE. TEMPS HAVE BEEN ADJUSTED TO LATEST GUIDANCE.

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 /TONIGHT 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. TIMING OF
THE PRECIP WILL BE CRITICAL TO PROVIDING TIME FOR SURFACE TEMPS IN
THE SOUTHERN RIDGES TO RISE. FOR NOW WILL MENTION A CHANCE FOR
FREEZING RAIN IN THE SOUTHERN RIDGES...BUT CONFIDENCE IS LOW.

&&

.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 /06Z 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 200614
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
114 AM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
OVERNIGHT PERIOD IN GOOD SHAPE. STRATOCU REMAINS TRAPPED UNDER
WEAK RIDGE. TEMPS HAVE BEEN ADJUSTED TO LATEST GUIDANCE.

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 /TONIGHT 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. TIMING OF
THE PRECIP WILL BE CRITICAL TO PROVIDING TIME FOR SURFACE TEMPS IN
THE SOUTHERN RIDGES TO RISE. FOR NOW WILL MENTION A CHANCE FOR
FREEZING RAIN IN THE SOUTHERN RIDGES...BUT CONFIDENCE IS LOW.

&&

.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 /06Z 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 200614
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
114 AM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
OVERNIGHT PERIOD IN GOOD SHAPE. STRATOCU REMAINS TRAPPED UNDER
WEAK RIDGE. TEMPS HAVE BEEN ADJUSTED TO LATEST GUIDANCE.

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 /TONIGHT 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. TIMING OF
THE PRECIP WILL BE CRITICAL TO PROVIDING TIME FOR SURFACE TEMPS IN
THE SOUTHERN RIDGES TO RISE. FOR NOW WILL MENTION A CHANCE FOR
FREEZING RAIN IN THE SOUTHERN RIDGES...BUT CONFIDENCE IS LOW.

&&

.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 /06Z 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 200614
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
114 AM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
OVERNIGHT PERIOD IN GOOD SHAPE. STRATOCU REMAINS TRAPPED UNDER
WEAK RIDGE. TEMPS HAVE BEEN ADJUSTED TO LATEST GUIDANCE.

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 /TONIGHT 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. TIMING OF
THE PRECIP WILL BE CRITICAL TO PROVIDING TIME FOR SURFACE TEMPS IN
THE SOUTHERN RIDGES TO RISE. FOR NOW WILL MENTION A CHANCE FOR
FREEZING RAIN IN THE SOUTHERN RIDGES...BUT CONFIDENCE IS LOW.

&&

.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 /06Z 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 KAKQ 200558
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1258 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST LATE TONIGHT THROUGH SATURDAY NIGHT. 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 COAST LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH TODAY/...
QUIET ACROSS THE FORECAST AREA THIS EVENING AS UPPER/SFC HIGH
PRESSURE BUILDS INTO THE REGION. LIGHT NLY WINDS...THIN HIGH
CLOUDS AND DEWPOINTS IN THE LOW-MID 20S HAVE ALLOWED TEMPS TO
QUICKLY DROP INTO THE LOW-MID 30S INLAND AND UPPER 30S NEAR THE
COAST THIS EVENING. UPSTREAM SHORTWAVE ENERGY AND INCREASING
MOISTURE WILL THICKEN AND LOWER THE CLOUD DECK. INCREASING CLOUDS
AND MODELS SUGGEST TEMPS WILL LEVEL OFF THRU THE
OVERNIGHT...FALLING INTO THE MID-UPPER 20S. 295K SFC DEPICTS
INCREASING ISENTROPIC LIFT OVER THE REGION BY LATE TONIGHT AS
SMALL AMPLITUDE SHORTWAVE ENERGY LIFTS INTO THE REGION. WINDS
ALOFT ALSO INCREASE. HOWEVER...COND PRES DEFICIT AND BUFR
SOUNDINGS DEPICT TOO MUCH DRY AIR FOR ANY FORCING TO OVERCOME. THE
RESULT WILL BE A DRY FORECAST THRU THE OVERNIGHT.

SAT...SYSTEM FROM THE GULF CONTINUES TO REMAIN SHUNTED OFF TO OUR
SOUTH AS MID LEVEL FLOW REMAINS FAIRLY ZONAL. NAM/GFS STILL SHOW
SOME FORCING ALOFT MAKING WAY INTO PIEDMONT BETWEEN 12-18Z/SAT AND
BUFKIT SOUNDINGS SHOW SOME MODEST LIFT THROUGH THE DENDRITIC
GROWTH LAYER. PTYPE ACRS THE PIEDMONT WOULD TEND TO BE SNOW/SLEET
SAT AM ALTHOUGH SFC TEMPS SHOULD BE ABOVE 32 F (SFC WET BULBS IN
THE UPPER 20S INITIALLY). LOW LEVELS REMAIN QUITE DRY HOWEVER...SO ANY
PRECIP WILL BE VERY LIGHT (GENLY A FEW HUNDREDTHS IF THAT...WITH A
TRACE MORE LIKELY). THUS...WILL ONLY GO WITH 30% POPS AT MOST. BY
LATE MORNING/EARLY AFTN...AREA OF FORCING OVER THE PIEDMONT/CENTRAL
VA WEAKENS AS THE SFC LOW PUSHES OFF THE SE COAST. WILL CARRY LOW
CHC POPS IN FAR SE ZONES (ALL RAIN) THROUGH THE AFTN (ALTHOUGH
MOST OF THE PRECIP SHOULD STAY S OF THE CWA). CLOUDY TO MSTLY
CLOUDY W/ HIGHS GENLY 40-45 F SAT.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...
SFC HIGH PRESSURE NOSES SOUTH INTO THE REGION SAT NIGHT/SUN...WITH DRY
CONDS THEN FOR SAT NGT AND SUN. LOWS IN THE 20S N TO THE 30S SE
SAT NIGHT...WITH HIGHS MAINLY FROM 45-50 F ON SUN. NEXT SYSTEM...THIS
ONE MORE AMPLIFIED WILL AFFECT THE AREA ON MON...WITH LIKELY POPS
ALL ZONES BY LATE MON AM/MON AFTN. LOOKS LIKE ALL RAIN ASIDE FROM
A BRIEF MIX POSSIBLE AT ONSET IN FAR NW COUNTIES. HIGHS MON ONLY
AROUND 40 F 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 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 /06Z 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.

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...
HIGH PRESSURE REMAINS NW OF THE REGION TONIGHT...WITH LINGERING
LIGHT CAA ALONG THE COAST. THIS WILL MAINTAIN A 10-15KT NNW WIND
OVERNIGHT...WITH 2-3FT SEAS IN THE OCEAN AND 1-2FT WAVES IN THE BAY.
HIGH PRESSURE SPREADS ACROSS NEW ENGLAND SATURDAY AND SATURDAY
NIGHT...WITH THE SURFACE RIDGE AXIS REMAINING INLAND OVER THE
PIEDMONT. THIS WILL MAINTAIN LIGHT (5-10KT) NORTHERLY FLOW OVER THE
MARINE AREA. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY
NIGHT...AS LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY
NIGHT...AND THEN TRACKS NE OFF THE MID ATLANTIC COAST MONDAY AND
MONDAY NIGHT. THE SURFACE PRESSURE GRADIENT TIGHTENS AHEAD OF THE
LOW MONDAY...WHICH HAS THE POTENTIAL TO PRODUCE 15-20KT EASTERLY
FLOW OVER THE OCEAN AND LOWER BAY. THIS ONSHORE FLOW 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 LATER MONDAY
NIGHT INTO TUESDAY. A STRONG LOW PRESSURE SYSTEM TRACKS W OF THE
MOUNTAINS TUESDAY NIGHT...WITH A STRONG COLD FRONT CROSSING 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/SAM
SHORT TERM...LKB/MAS
LONG TERM...AJZ/MAS
AVIATION...MAM/LSA
MARINE...AJZ








000
FXUS61 KAKQ 200558
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1258 AM EST SAT DEC 20 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST LATE TONIGHT THROUGH SATURDAY NIGHT. 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 COAST LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH TODAY/...
QUIET ACROSS THE FORECAST AREA THIS EVENING AS UPPER/SFC HIGH
PRESSURE BUILDS INTO THE REGION. LIGHT NLY WINDS...THIN HIGH
CLOUDS AND DEWPOINTS IN THE LOW-MID 20S HAVE ALLOWED TEMPS TO
QUICKLY DROP INTO THE LOW-MID 30S INLAND AND UPPER 30S NEAR THE
COAST THIS EVENING. UPSTREAM SHORTWAVE ENERGY AND INCREASING
MOISTURE WILL THICKEN AND LOWER THE CLOUD DECK. INCREASING CLOUDS
AND MODELS SUGGEST TEMPS WILL LEVEL OFF THRU THE
OVERNIGHT...FALLING INTO THE MID-UPPER 20S. 295K SFC DEPICTS
INCREASING ISENTROPIC LIFT OVER THE REGION BY LATE TONIGHT AS
SMALL AMPLITUDE SHORTWAVE ENERGY LIFTS INTO THE REGION. WINDS
ALOFT ALSO INCREASE. HOWEVER...COND PRES DEFICIT AND BUFR
SOUNDINGS DEPICT TOO MUCH DRY AIR FOR ANY FORCING TO OVERCOME. THE
RESULT WILL BE A DRY FORECAST THRU THE OVERNIGHT.

SAT...SYSTEM FROM THE GULF CONTINUES TO REMAIN SHUNTED OFF TO OUR
SOUTH AS MID LEVEL FLOW REMAINS FAIRLY ZONAL. NAM/GFS STILL SHOW
SOME FORCING ALOFT MAKING WAY INTO PIEDMONT BETWEEN 12-18Z/SAT AND
BUFKIT SOUNDINGS SHOW SOME MODEST LIFT THROUGH THE DENDRITIC
GROWTH LAYER. PTYPE ACRS THE PIEDMONT WOULD TEND TO BE SNOW/SLEET
SAT AM ALTHOUGH SFC TEMPS SHOULD BE ABOVE 32 F (SFC WET BULBS IN
THE UPPER 20S INITIALLY). LOW LEVELS REMAIN QUITE DRY HOWEVER...SO ANY
PRECIP WILL BE VERY LIGHT (GENLY A FEW HUNDREDTHS IF THAT...WITH A
TRACE MORE LIKELY). THUS...WILL ONLY GO WITH 30% POPS AT MOST. BY
LATE MORNING/EARLY AFTN...AREA OF FORCING OVER THE PIEDMONT/CENTRAL
VA WEAKENS AS THE SFC LOW PUSHES OFF THE SE COAST. WILL CARRY LOW
CHC POPS IN FAR SE ZONES (ALL RAIN) THROUGH THE AFTN (ALTHOUGH
MOST OF THE PRECIP SHOULD STAY S OF THE CWA). CLOUDY TO MSTLY
CLOUDY W/ HIGHS GENLY 40-45 F SAT.

&&

.SHORT TERM /TONIGHT THROUGH MONDAY/...
SFC HIGH PRESSURE NOSES SOUTH INTO THE REGION SAT NIGHT/SUN...WITH DRY
CONDS THEN FOR SAT NGT AND SUN. LOWS IN THE 20S N TO THE 30S SE
SAT NIGHT...WITH HIGHS MAINLY FROM 45-50 F ON SUN. NEXT SYSTEM...THIS
ONE MORE AMPLIFIED WILL AFFECT THE AREA ON MON...WITH LIKELY POPS
ALL ZONES BY LATE MON AM/MON AFTN. LOOKS LIKE ALL RAIN ASIDE FROM
A BRIEF MIX POSSIBLE AT ONSET IN FAR NW COUNTIES. HIGHS MON ONLY
AROUND 40 F 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 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 /06Z 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.

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...
HIGH PRESSURE REMAINS NW OF THE REGION TONIGHT...WITH LINGERING
LIGHT CAA ALONG THE COAST. THIS WILL MAINTAIN A 10-15KT NNW WIND
OVERNIGHT...WITH 2-3FT SEAS IN THE OCEAN AND 1-2FT WAVES IN THE BAY.
HIGH PRESSURE SPREADS ACROSS NEW ENGLAND SATURDAY AND SATURDAY
NIGHT...WITH THE SURFACE RIDGE AXIS REMAINING INLAND OVER THE
PIEDMONT. THIS WILL MAINTAIN LIGHT (5-10KT) NORTHERLY FLOW OVER THE
MARINE AREA. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY
NIGHT...AS LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY
NIGHT...AND THEN TRACKS NE OFF THE MID ATLANTIC COAST MONDAY AND
MONDAY NIGHT. THE SURFACE PRESSURE GRADIENT TIGHTENS AHEAD OF THE
LOW MONDAY...WHICH HAS THE POTENTIAL TO PRODUCE 15-20KT EASTERLY
FLOW OVER THE OCEAN AND LOWER BAY. THIS ONSHORE FLOW 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 LATER MONDAY
NIGHT INTO TUESDAY. A STRONG LOW PRESSURE SYSTEM TRACKS W OF THE
MOUNTAINS TUESDAY NIGHT...WITH A STRONG COLD FRONT CROSSING 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/SAM
SHORT TERM...LKB/MAS
LONG TERM...AJZ/MAS
AVIATION...MAM/LSA
MARINE...AJZ







000
FXUS61 KPBZ 200547 AAC
AFDPBZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PITTSBURGH PA
1247 AM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
OVERNIGHT PERIOD IN GOOD SHAPE. STRATOCU REMAINS TRAPPED UNDER
WEAK RIDGE. TEMPS HAVE BEEN ADJUSTED TO LATEST GUIDANCE.

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 /TONIGHT 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. TIMING OF
THE PRECIP WILL BE CRITICAL TO PROVIDING TIME FOR SURFACE TEMPS IN
THE SOUTHERN RIDGES TO RISE. FOR NOW WILL MENTION A CHANCE FOR
FREEZING RAIN IN THE SOUTHERN RIDGES...BUT CONFIDENCE IS LOW.

&&

.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 /06Z SATURDAY THROUGH WEDNESDAY/...
PERVASIVE STRATUS COVERS ALL SITES THIS EVENING...WHILE BOUNDARY
LAYER MOISTURE HAS DROPPED OFF FROM EARLIER TODAY. GIVEN STRONG
INVERSIONS...STRATUS SEEMS LIKELY TO CONTINUE FOR THE NEXT DAY AT
LEAST...HOWEVER GIVEN A BIT WIDER DEWPOINT DEPRESSIONS...LIGHT
PRECIPITATION CHANCES SEEM VERY LOW. MVFR CONDITIONS SEEM LIKELY
TO CONTINUE. FRIES


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$







000
FXUS61 KPBZ 200547 AAC
AFDPBZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PITTSBURGH PA
1247 AM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
OVERNIGHT PERIOD IN GOOD SHAPE. STRATOCU REMAINS TRAPPED UNDER
WEAK RIDGE. TEMPS HAVE BEEN ADJUSTED TO LATEST GUIDANCE.

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 /TONIGHT 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. TIMING OF
THE PRECIP WILL BE CRITICAL TO PROVIDING TIME FOR SURFACE TEMPS IN
THE SOUTHERN RIDGES TO RISE. FOR NOW WILL MENTION A CHANCE FOR
FREEZING RAIN IN THE SOUTHERN RIDGES...BUT CONFIDENCE IS LOW.

&&

.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 /06Z SATURDAY THROUGH WEDNESDAY/...
PERVASIVE STRATUS COVERS ALL SITES THIS EVENING...WHILE BOUNDARY
LAYER MOISTURE HAS DROPPED OFF FROM EARLIER TODAY. GIVEN STRONG
INVERSIONS...STRATUS SEEMS LIKELY TO CONTINUE FOR THE NEXT DAY AT
LEAST...HOWEVER GIVEN A BIT WIDER DEWPOINT DEPRESSIONS...LIGHT
PRECIPITATION CHANCES SEEM VERY LOW. MVFR CONDITIONS SEEM LIKELY
TO CONTINUE. FRIES


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$







000
FXUS61 KPBZ 200547 AAC
AFDPBZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PITTSBURGH PA
1247 AM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
OVERNIGHT PERIOD IN GOOD SHAPE. STRATOCU REMAINS TRAPPED UNDER
WEAK RIDGE. TEMPS HAVE BEEN ADJUSTED TO LATEST GUIDANCE.

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 /TONIGHT 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. TIMING OF
THE PRECIP WILL BE CRITICAL TO PROVIDING TIME FOR SURFACE TEMPS IN
THE SOUTHERN RIDGES TO RISE. FOR NOW WILL MENTION A CHANCE FOR
FREEZING RAIN IN THE SOUTHERN RIDGES...BUT CONFIDENCE IS LOW.

&&

.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 /06Z SATURDAY THROUGH WEDNESDAY/...
PERVASIVE STRATUS COVERS ALL SITES THIS EVENING...WHILE BOUNDARY
LAYER MOISTURE HAS DROPPED OFF FROM EARLIER TODAY. GIVEN STRONG
INVERSIONS...STRATUS SEEMS LIKELY TO CONTINUE FOR THE NEXT DAY AT
LEAST...HOWEVER GIVEN A BIT WIDER DEWPOINT DEPRESSIONS...LIGHT
PRECIPITATION CHANCES SEEM VERY LOW. MVFR CONDITIONS SEEM LIKELY
TO CONTINUE. FRIES


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$







000
FXUS61 KPBZ 200547 AAC
AFDPBZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PITTSBURGH PA
1247 AM EST SAT DEC 20 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
OVERNIGHT PERIOD IN GOOD SHAPE. STRATOCU REMAINS TRAPPED UNDER
WEAK RIDGE. TEMPS HAVE BEEN ADJUSTED TO LATEST GUIDANCE.

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 /TONIGHT 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. TIMING OF
THE PRECIP WILL BE CRITICAL TO PROVIDING TIME FOR SURFACE TEMPS IN
THE SOUTHERN RIDGES TO RISE. FOR NOW WILL MENTION A CHANCE FOR
FREEZING RAIN IN THE SOUTHERN RIDGES...BUT CONFIDENCE IS LOW.

&&

.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 /06Z SATURDAY THROUGH WEDNESDAY/...
PERVASIVE STRATUS COVERS ALL SITES THIS EVENING...WHILE BOUNDARY
LAYER MOISTURE HAS DROPPED OFF FROM EARLIER TODAY. GIVEN STRONG
INVERSIONS...STRATUS SEEMS LIKELY TO CONTINUE FOR THE NEXT DAY AT
LEAST...HOWEVER GIVEN A BIT WIDER DEWPOINT DEPRESSIONS...LIGHT
PRECIPITATION CHANCES SEEM VERY LOW. MVFR CONDITIONS SEEM LIKELY
TO CONTINUE. FRIES


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$







000
FXUS61 KAKQ 200318
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1018 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST LATE TONIGHT THROUGH SATURDAY NIGHT. 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 COAST LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH SATURDAY/...
QUIET ACROSS THE FORECAST AREA THIS EVENING AS UPPER/SFC HIGH
PRESSURE BUILDS INTO THE REGION. LIGHT NLY WINDS...THIN HIGH
CLOUDS AND DEWPOINTS IN THE LOW-MID 20S HAVE ALLOWED TEMPS TO
QUICKLY DROP INTO THE LOW-MID 30S INLAND AND UPPER 30S NEAR THE
COAST THIS EVENING. UPSTREAM SHORTWAVE ENERGY AND INCREASING
MOISTURE WILL THICKEN AND LOWER THE CLOUD DECK. INCREASING CLOUDS
AND MODELS SUGGEST TEMPS WILL LEVEL OFF THRU THE
OVERNIGHT...FALLING INTO THE MID-UPPER 20S. 295K SFC DEPICTS
INCREASING ISENTROPIC LIFT OVER THE REGION BY LATE TONIGHT AS
SMALL AMPLITUDE SHORTWAVE ENERGY LIFTS INTO THE REGION. WINDS
ALOFT ALSO INCREASE. HOWEVER...COND PRES DEFICIT AND BUFR
SOUNDINGS DEPICT TOO MUCH DRY AIR FOR ANY FORCING TO OVERCOME. THE
RESULT WILL BE A DRY FORECAST THRU THE OVERNIGHT.

SAT...SYSTEM FROM THE GULF CONTINUES TO REMAIN SHUNTED OFF TO OUR
SOUTH AS MID LEVEL FLOW REMAINS FAIRLY ZONAL. NAM/GFS STILL SHOW
SOME FORCING ALOFT MAKING WAY INTO PIEDMONT BETWEEN 12-18Z/SAT AND
BUFKIT SOUNDINGS SHOW SOME MODEST LIFT THROUGH THE DENDRITIC
GROWTH LAYER. PTYPE ACRS THE PIEDMONT WOULD TEND TO BE SNOW/SLEET
SAT AM ALTHOUGH SFC TEMPS SHOULD BE ABOVE 32 F (SFC WET BULBS IN
THE UPPER 20S INITIALLY). LOW LEVELS REMAIN QUITE DRY HOWEVER...SO ANY
PRECIP WILL BE VERY LIGHT (GENLY A FEW HUNDREDTHS IF THAT...WITH A
TRACE MORE LIKELY). THUS...WILL ONLY GO WITH 30% POPS AT MOST. BY
LATE MORNING/EARLY AFTN...AREA OF FORCING OVER THE PIEDMONT/CENTRAL
VA WEAKENS AS THE SFC LOW PUSHES OFF THE SE COAST. WILL CARRY LOW
CHC POPS IN FAR SE ZONES (ALL RAIN) THROUGH THE AFTN (ALTHOUGH
MOST OF THE PRECIP SHOULD STAY S OF THE CWA). CLOUDY TO MSTLY
CLOUDY W/ HIGHS GENLY 40-45 F SAT.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
SFC HIGH PRESSURE NOSES SOUTH INTO THE REGION SAT NIGHT/SUN...WITH DRY
CONDS THEN FOR SAT NGT AND SUN. LOWS IN THE 20S N TO THE 30S SE
SAT NIGHT...WITH HIGHS MAINLY FROM 45-50 F ON SUN. NEXT SYSTEM...THIS
ONE MORE AMPLIFIED WILL AFFECT THE AREA ON MON...WITH LIKELY POPS
ALL ZONES BY LATE MON AM/MON AFTN. LOOKS LIKE ALL RAIN ASIDE FROM
A BRIEF MIX POSSIBLE AT ONSET IN FAR NW COUNTIES. HIGHS MON ONLY
AROUND 40 F 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 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 /03Z SATURDAY THROUGH WEDNESDAY/...
STRATUS THAT WAS OVER THE LOWER EASTERN SHORE FRIDAY AFTN APPEAR TO
BE MOVING OFFSHORE. A SURFACE LOW NEAR THE GULF COAST AND AN UPPER
LEVEL DISTURBANCE THAT WILL MOVE ACROSS THE MID ATLANTIC STATES MAY
PRODUCE LIGHT RAIN IN FAR SRN PORTIONS OF THE AREA. WHILE ONLY HIGH
CLOUDS ARE EXPECTED OVERNIGHT...MOS BUFR SOUNDINGS HAVE CLOUD BASES
LOWERING SIGNIFICANTLY AT ALL TAF SITES EXCEPT SBY ON SATURDAY. MVFR
CIGS ARE FORECAST AT PHF ORF AND ECG. LIGHT RAIN BUT WITH NO VSBY
RESTRICTION ARE IN THE TAFS AT ORF AND ECG.

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...
HIGH PRESSURE REMAINS NW OF THE REGION TONIGHT...WITH LINGERING
LIGHT CAA ALONG THE COAST. THIS WILL MAINTAIN A 10-15KT NNW WIND
OVERNIGHT...WITH 2-3FT SEAS IN THE OCEAN AND 1-2FT WAVES IN THE BAY.
HIGH PRESSURE SPREADS ACROSS NEW ENGLAND SATURDAY AND SATURDAY
NIGHT...WITH THE SURFACE RIDGE AXIS REMAINING INLAND OVER THE
PIEDMONT. THIS WILL MAINTAIN LIGHT (5-10KT) NORTHERLY FLOW OVER THE
MARINE AREA. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY
NIGHT...AS LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY
NIGHT...AND THEN TRACKS NE OFF THE MID ATLANTIC COAST MONDAY AND
MONDAY NIGHT. THE SURFACE PRESSURE GRADIENT TIGHTENS AHEAD OF THE
LOW MONDAY...WHICH HAS THE POTENTIAL TO PRODUCE 15-20KT EASTERLY
FLOW OVER THE OCEAN AND LOWER BAY. THIS ONSHORE FLOW 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 LATER MONDAY
NIGHT INTO TUESDAY. A STRONG LOW PRESSURE SYSTEM TRACKS W OF THE
MOUNTAINS TUESDAY NIGHT...WITH A STRONG COLD FRONT CROSSING 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/SAM
SHORT TERM...LKB/MAS
LONG TERM...AJZ/MAS
AVIATION...LSA
MARINE...AJZ






000
FXUS61 KAKQ 200318
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1018 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST LATE TONIGHT THROUGH SATURDAY NIGHT. 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 COAST LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH SATURDAY/...
QUIET ACROSS THE FORECAST AREA THIS EVENING AS UPPER/SFC HIGH
PRESSURE BUILDS INTO THE REGION. LIGHT NLY WINDS...THIN HIGH
CLOUDS AND DEWPOINTS IN THE LOW-MID 20S HAVE ALLOWED TEMPS TO
QUICKLY DROP INTO THE LOW-MID 30S INLAND AND UPPER 30S NEAR THE
COAST THIS EVENING. UPSTREAM SHORTWAVE ENERGY AND INCREASING
MOISTURE WILL THICKEN AND LOWER THE CLOUD DECK. INCREASING CLOUDS
AND MODELS SUGGEST TEMPS WILL LEVEL OFF THRU THE
OVERNIGHT...FALLING INTO THE MID-UPPER 20S. 295K SFC DEPICTS
INCREASING ISENTROPIC LIFT OVER THE REGION BY LATE TONIGHT AS
SMALL AMPLITUDE SHORTWAVE ENERGY LIFTS INTO THE REGION. WINDS
ALOFT ALSO INCREASE. HOWEVER...COND PRES DEFICIT AND BUFR
SOUNDINGS DEPICT TOO MUCH DRY AIR FOR ANY FORCING TO OVERCOME. THE
RESULT WILL BE A DRY FORECAST THRU THE OVERNIGHT.

SAT...SYSTEM FROM THE GULF CONTINUES TO REMAIN SHUNTED OFF TO OUR
SOUTH AS MID LEVEL FLOW REMAINS FAIRLY ZONAL. NAM/GFS STILL SHOW
SOME FORCING ALOFT MAKING WAY INTO PIEDMONT BETWEEN 12-18Z/SAT AND
BUFKIT SOUNDINGS SHOW SOME MODEST LIFT THROUGH THE DENDRITIC
GROWTH LAYER. PTYPE ACRS THE PIEDMONT WOULD TEND TO BE SNOW/SLEET
SAT AM ALTHOUGH SFC TEMPS SHOULD BE ABOVE 32 F (SFC WET BULBS IN
THE UPPER 20S INITIALLY). LOW LEVELS REMAIN QUITE DRY HOWEVER...SO ANY
PRECIP WILL BE VERY LIGHT (GENLY A FEW HUNDREDTHS IF THAT...WITH A
TRACE MORE LIKELY). THUS...WILL ONLY GO WITH 30% POPS AT MOST. BY
LATE MORNING/EARLY AFTN...AREA OF FORCING OVER THE PIEDMONT/CENTRAL
VA WEAKENS AS THE SFC LOW PUSHES OFF THE SE COAST. WILL CARRY LOW
CHC POPS IN FAR SE ZONES (ALL RAIN) THROUGH THE AFTN (ALTHOUGH
MOST OF THE PRECIP SHOULD STAY S OF THE CWA). CLOUDY TO MSTLY
CLOUDY W/ HIGHS GENLY 40-45 F SAT.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
SFC HIGH PRESSURE NOSES SOUTH INTO THE REGION SAT NIGHT/SUN...WITH DRY
CONDS THEN FOR SAT NGT AND SUN. LOWS IN THE 20S N TO THE 30S SE
SAT NIGHT...WITH HIGHS MAINLY FROM 45-50 F ON SUN. NEXT SYSTEM...THIS
ONE MORE AMPLIFIED WILL AFFECT THE AREA ON MON...WITH LIKELY POPS
ALL ZONES BY LATE MON AM/MON AFTN. LOOKS LIKE ALL RAIN ASIDE FROM
A BRIEF MIX POSSIBLE AT ONSET IN FAR NW COUNTIES. HIGHS MON ONLY
AROUND 40 F 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 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 /03Z SATURDAY THROUGH WEDNESDAY/...
STRATUS THAT WAS OVER THE LOWER EASTERN SHORE FRIDAY AFTN APPEAR TO
BE MOVING OFFSHORE. A SURFACE LOW NEAR THE GULF COAST AND AN UPPER
LEVEL DISTURBANCE THAT WILL MOVE ACROSS THE MID ATLANTIC STATES MAY
PRODUCE LIGHT RAIN IN FAR SRN PORTIONS OF THE AREA. WHILE ONLY HIGH
CLOUDS ARE EXPECTED OVERNIGHT...MOS BUFR SOUNDINGS HAVE CLOUD BASES
LOWERING SIGNIFICANTLY AT ALL TAF SITES EXCEPT SBY ON SATURDAY. MVFR
CIGS ARE FORECAST AT PHF ORF AND ECG. LIGHT RAIN BUT WITH NO VSBY
RESTRICTION ARE IN THE TAFS AT ORF AND ECG.

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...
HIGH PRESSURE REMAINS NW OF THE REGION TONIGHT...WITH LINGERING
LIGHT CAA ALONG THE COAST. THIS WILL MAINTAIN A 10-15KT NNW WIND
OVERNIGHT...WITH 2-3FT SEAS IN THE OCEAN AND 1-2FT WAVES IN THE BAY.
HIGH PRESSURE SPREADS ACROSS NEW ENGLAND SATURDAY AND SATURDAY
NIGHT...WITH THE SURFACE RIDGE AXIS REMAINING INLAND OVER THE
PIEDMONT. THIS WILL MAINTAIN LIGHT (5-10KT) NORTHERLY FLOW OVER THE
MARINE AREA. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY
NIGHT...AS LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY
NIGHT...AND THEN TRACKS NE OFF THE MID ATLANTIC COAST MONDAY AND
MONDAY NIGHT. THE SURFACE PRESSURE GRADIENT TIGHTENS AHEAD OF THE
LOW MONDAY...WHICH HAS THE POTENTIAL TO PRODUCE 15-20KT EASTERLY
FLOW OVER THE OCEAN AND LOWER BAY. THIS ONSHORE FLOW 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 LATER MONDAY
NIGHT INTO TUESDAY. A STRONG LOW PRESSURE SYSTEM TRACKS W OF THE
MOUNTAINS TUESDAY NIGHT...WITH A STRONG COLD FRONT CROSSING 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/SAM
SHORT TERM...LKB/MAS
LONG TERM...AJZ/MAS
AVIATION...LSA
MARINE...AJZ







000
FXUS61 KPHI 200240
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
940 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE JUST NORTH OF LAKE HURON WILL GRADUALLY MOVE
EASTWARD INTO NORTHERN NEW ENGLAND THRU MONDAY. A WAVE OF LOW
PRESSURE WILL FORM ALONG THE MID-ATLANTIC COASTLINE ON MONDAY AND
MOVE NORTHEASTWARD JUST OFFSHORE ON TUESDAY. A STRONG AREA OF
LOW PRESSURE WILL THEN FORM OVER THE MISSISSIPPI VALLEY AND MOVE
THRU THE GREAT LAKES REGION DURING THE MIDDLE OF THE
WEEK, BRINGING A STRONG COLD FRONT THRU THE REGION BY THURSDAY.
HIGH PRESSURE IS PROJECTED TO BUILD IN ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LOW CLOUDS STILL WORKING THEIR WAY SOUTHWARD DEEPER INTO OUR CWA.
IT DOES FEEL LIKE WE ARE STUCK IN THE STRATOCUMULUS VERSION OF
GROUND HOG DAY. OVERNIGHT THERE IS A LOW LEVEL VORT MAX THAT IS
KEEPING THE LOW CLOUDS PERPETUATING AND JUST ENOUGH OF AN
INVERSION TO GIVE THEM A COMFORT LEVEL. IT LOOKS TO TAKE MOST OF
THE OVERNIGHT FOR THIS TO FEATURE TO CLEAR. LATER AT NIGHT SOME OF
THE CIRRUS FROM THE ONCE FORMIDABLE LOOKING SOUTHERN STREAM SYSTEM
WILL ALSO REACH OUR CWA.

OUR ADJUSTMENT WAS TO INCREASE CLOUD COVERAGE, ESP NORTH AND BUMP
UP MIN TEMPS THERE. IN THE SOUTHERN HALF OF OUR CWA, THE SHORT
WAVE TRAJ BYPASSES IT, SO WE WENT WITH A PTLY CLDY NIGHT. WINDS
ARE LIGHT ENOUGH THAT WE KEPT RADIATING MINS IN THE NJ PINE
BARRENS AND INTERIOR DELMARVA. THERE WILL BE SOME FROST SCRAPING
COME SATURDAY MORNING IN THOSE AREAS.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
FOR SATURDAY...HIGH PRES CENTERED OVER CANADA SHIFTS EWD FROM
ONTARIO INTO QUEBEC. A RIDGE AXIS IS FCST TO EXTEND SWD THROUGH THE
MID-ATLANTIC REGION RESULTING IN ONLY LIGHT NLY WINDS. SOME LOW-LVL
MOISTURE SHOULD REMAIN TRAPPED BELOW THE LARGE-SCALE SUBSIDENCE
INVERSION BUT HARD TO SAY HOW EXTENSIVE ANY LOW CLOUDS MAY BE. THE
12-KM NAM SHOWS A THIN LOW CLOUD LAYER DEVELOPING DURG THE DAY BUT
HIGHER-RES ARW/NMM AND THE GFS DO NOT. THERE WILL BE SOME HIGHER
CLOUDS ALSO ASSOCD WITH THE SHRTWV NOW MOVING ENEWD OUT OF THE SRN
PLAINS...HWVR POPS REMAIN NEAR ZERO.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* SLIGHT CHANCE OF SNOW SHOWERS SUNDAY MORNING MAINLY NORTH.
* SNOW POSSIBLE NORTHWEST OF THE I-95 CORRIDOR LATE MONDAY
  THRU EARLY TUESDAY.
* POTENTIAL FOR HEAVY RAIN INCREASING ON CHRISTMAS EVE DAY.

OVERVIEW...

MID-LEVEL BLOCKING PATTERN OVER NOAM BEGINS TO DISLODGE IN RESPONSE
JET ENERGY MOVING INTO THE PACIFIC NORTHWEST THIS WEEKEND...CARVING
OUT A DEEP TROUGH OVER THE MS VALLEY EARLY EARLY NEXT WEEK...WHICH
LEADS TO INCLEMENT WEATHER IN THE TUESDAY THRU WEDNESDAY TIME FRAME.

DETAILS...

SUNDAY...
SHORTWAVE LIFTING THROUGH THE REGION EARLY IN THE DAY MAY GENERATE
ENOUGH LIFT ALONG WITH MARGINAL MOISTURE IN THE COLUMN TO PRODUCE
SOME LIGHT SNOW SHOWERS...MAINLY DURING THE PRE-DAWN HOURS. LITTLE
IF ANY ACCUMULATION EXPECTED AS MOISTURE IS VERY LIMITED. RIDGING
THEN BUILDS IN SO FAIR WEATHER IS EXPECTED THE REMAINDER OF THE DAY.

MONDAY AND TUESDAY...
HIGH PRESSURE ANCHORS ALONG THE LEE OF THE APPALACHIANS. A SOUTHERN
STREAM SHORTWAVE WILL INDUCE LOW-PRESSURE OF THE MID-ATLANTIC COAST.
MODELS BRING QPF NORTHWARD INTO THE AREA ON MONDAY NIGHT INTO EARLY
TUESDAY. THERMAL PROFILES ARE COLD ENOUGH FOR SNOW TO THE NORTHWEST
OF THE I-95 CORRIDOR...BUT THE BEST LIFT IS FOCUSED JUST SOUTHEAST
OF THIS AREA...AND THE SYSTEM COULD TRACK FURTHER TO THE SOUTH PER
12Z UKMET MODEL. STILL A LOT OF UNCERTAINTY WITH ULTIMATE TRACK.

WEDNESDAY...
A MID-LEVEL RIDGE WILL MOVE THROUGH THE REGION TUESDAY NIGHT INTO
EARLY WEDNESDAY LEADING TO A BRIEF RESPITE BETWEEN WEATHER SYSTEMS.
THEN A MID-LEVEL TROUGH IS PROJECTED TO BECOME NEGATIVELY TILTED
OVER THE OHIO VALLEY ON WED...LEADING TO A MERIDIONAL FLOW ALONG
THE EAST COAST...WITH THE ENTIRE COLUMN EXPECTED TO BE WELL ABOVE
FREEZING ACROSS THE CWA FAVORING A RAIN EVENT. THERE ARE SEVERAL
INGREDIENTS COMING TOGETHER FOR HEAVY RAIN. IN PARTICULAR...DEEP
GULF MOISTURE...LOW-LEVEL ISENTROPIC LIFT...MID-LEVEL PVA...AND
THE RIGHT-REAR QUADRANT OF A 140 KNOT UPPER-LEVEL JET JUST NORTH.
THE SYSTEM SHOULD BE FAIRLY PROGRESSIVE BUT WILL HAVE TO MONITOR
POTENTIAL FOR FLOODING.

THU AND FRI...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS
TO BUILD IN. TEMPERATURES WILL RETURN TO SEASONABLE LEVELS AND
THERE COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THE 00Z TAFS TAKE CIGS DOWN TO MVFR LEVELS TONIGHT FROM THE KPHL
AREA AIRPORTS NORTHWESTWARD WITH IMPROVEMENT ON SATURDAY. ITS BEEN
TOUGH TO SHAKE THIS STRATOCU LEVEL CLOUDINESS PATTERN.

FOR TONIGHT. LOW CLOUDS ADVANCING IN FROM THE HIGHER TERRAIN
AIRPORTS ARE STILL HEADING INTO THE TERMINALS. WE BRING MVFR CIG
POTENTIAL FROM THE GET GO AT KABE AND KRDG (HIER CONFIDENCE
OVERNIGHT) AND BRING IT DOWN TO THE KPHL METRO AIRPORTS AFTER 05Z.
WE LEAVE KACY AND KMIV VFR. WINDS WILL BE LIGHT FROM THE
NORTHWEST. NO VSBY RESTRICTIONS EXPECTED.

ON SATURDAY, PREDICTING THE MVFR CIG TO BECOME SCATTERED DURING
THE MORNING FROM THE KPHL METRO AIRPORTS NWWD WITH A CIRRUS CIG
ABOVE. KACY AND KMIV NOT EXPECTING A MVFR CIG. IT WILL BE A WEAK
PRESSURE PATTERN AND WINDS WILL BE LIGHT. A NORTHERLY DIRECTION
IS FAVORED, BUT SPEEDS ARE EXPECTED TO REMAIN BELOW 10 KNOTS,
PROBABLY PREDOMINATELY LESS THAN 6 KNOTS AT SOME OF THE MORE
RURAL AIRPORTS AND TERMINALS.

OUTLOOK...
SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED.
MONDAY AND TUESDAY...IFR POSSIBLE IN SHRA AND SHSN.
WEDNESDAY...IFR POSSIBLE IN RAIN AND FOG.

&&

.MARINE...
SUB-SCA CONDS ARE EXPECTED FOR THE NEXT 24 HOURS AT LEAST. SMWHT
GUST NW WINDS THIS EVENING WILL GRADUALLY DIMINISH TONIGHT THROUGH
SATURDAY AS A RIDGE OF HIGH PRES MOVES OVERHEAD. SEAS ARE
CURRENTLY RUNNING 2 TO 3 FT BUT THEY SHOULD GRADUALLY DIMINISH
ALSO.

OUTLOOK...
SUNDAY AND MONDAY...SUB-SCA CONDITIONS EXPECTED.
TUESDAY...SCA MAY BE NEEDED FOR BUILDING SEAS.
WEDNESDAY...GALE WARNING MAY BE NEEDED.

&&

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

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...GIGI
SHORT TERM...AMC
LONG TERM...FRANCK
AVIATION...FRANCK/GIGI
MARINE...AMC/FRANCK







000
FXUS61 KPHI 200240
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
940 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE JUST NORTH OF LAKE HURON WILL GRADUALLY MOVE
EASTWARD INTO NORTHERN NEW ENGLAND THRU MONDAY. A WAVE OF LOW
PRESSURE WILL FORM ALONG THE MID-ATLANTIC COASTLINE ON MONDAY AND
MOVE NORTHEASTWARD JUST OFFSHORE ON TUESDAY. A STRONG AREA OF
LOW PRESSURE WILL THEN FORM OVER THE MISSISSIPPI VALLEY AND MOVE
THRU THE GREAT LAKES REGION DURING THE MIDDLE OF THE
WEEK, BRINGING A STRONG COLD FRONT THRU THE REGION BY THURSDAY.
HIGH PRESSURE IS PROJECTED TO BUILD IN ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LOW CLOUDS STILL WORKING THEIR WAY SOUTHWARD DEEPER INTO OUR CWA.
IT DOES FEEL LIKE WE ARE STUCK IN THE STRATOCUMULUS VERSION OF
GROUND HOG DAY. OVERNIGHT THERE IS A LOW LEVEL VORT MAX THAT IS
KEEPING THE LOW CLOUDS PERPETUATING AND JUST ENOUGH OF AN
INVERSION TO GIVE THEM A COMFORT LEVEL. IT LOOKS TO TAKE MOST OF
THE OVERNIGHT FOR THIS TO FEATURE TO CLEAR. LATER AT NIGHT SOME OF
THE CIRRUS FROM THE ONCE FORMIDABLE LOOKING SOUTHERN STREAM SYSTEM
WILL ALSO REACH OUR CWA.

OUR ADJUSTMENT WAS TO INCREASE CLOUD COVERAGE, ESP NORTH AND BUMP
UP MIN TEMPS THERE. IN THE SOUTHERN HALF OF OUR CWA, THE SHORT
WAVE TRAJ BYPASSES IT, SO WE WENT WITH A PTLY CLDY NIGHT. WINDS
ARE LIGHT ENOUGH THAT WE KEPT RADIATING MINS IN THE NJ PINE
BARRENS AND INTERIOR DELMARVA. THERE WILL BE SOME FROST SCRAPING
COME SATURDAY MORNING IN THOSE AREAS.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
FOR SATURDAY...HIGH PRES CENTERED OVER CANADA SHIFTS EWD FROM
ONTARIO INTO QUEBEC. A RIDGE AXIS IS FCST TO EXTEND SWD THROUGH THE
MID-ATLANTIC REGION RESULTING IN ONLY LIGHT NLY WINDS. SOME LOW-LVL
MOISTURE SHOULD REMAIN TRAPPED BELOW THE LARGE-SCALE SUBSIDENCE
INVERSION BUT HARD TO SAY HOW EXTENSIVE ANY LOW CLOUDS MAY BE. THE
12-KM NAM SHOWS A THIN LOW CLOUD LAYER DEVELOPING DURG THE DAY BUT
HIGHER-RES ARW/NMM AND THE GFS DO NOT. THERE WILL BE SOME HIGHER
CLOUDS ALSO ASSOCD WITH THE SHRTWV NOW MOVING ENEWD OUT OF THE SRN
PLAINS...HWVR POPS REMAIN NEAR ZERO.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* SLIGHT CHANCE OF SNOW SHOWERS SUNDAY MORNING MAINLY NORTH.
* SNOW POSSIBLE NORTHWEST OF THE I-95 CORRIDOR LATE MONDAY
  THRU EARLY TUESDAY.
* POTENTIAL FOR HEAVY RAIN INCREASING ON CHRISTMAS EVE DAY.

OVERVIEW...

MID-LEVEL BLOCKING PATTERN OVER NOAM BEGINS TO DISLODGE IN RESPONSE
JET ENERGY MOVING INTO THE PACIFIC NORTHWEST THIS WEEKEND...CARVING
OUT A DEEP TROUGH OVER THE MS VALLEY EARLY EARLY NEXT WEEK...WHICH
LEADS TO INCLEMENT WEATHER IN THE TUESDAY THRU WEDNESDAY TIME FRAME.

DETAILS...

SUNDAY...
SHORTWAVE LIFTING THROUGH THE REGION EARLY IN THE DAY MAY GENERATE
ENOUGH LIFT ALONG WITH MARGINAL MOISTURE IN THE COLUMN TO PRODUCE
SOME LIGHT SNOW SHOWERS...MAINLY DURING THE PRE-DAWN HOURS. LITTLE
IF ANY ACCUMULATION EXPECTED AS MOISTURE IS VERY LIMITED. RIDGING
THEN BUILDS IN SO FAIR WEATHER IS EXPECTED THE REMAINDER OF THE DAY.

MONDAY AND TUESDAY...
HIGH PRESSURE ANCHORS ALONG THE LEE OF THE APPALACHIANS. A SOUTHERN
STREAM SHORTWAVE WILL INDUCE LOW-PRESSURE OF THE MID-ATLANTIC COAST.
MODELS BRING QPF NORTHWARD INTO THE AREA ON MONDAY NIGHT INTO EARLY
TUESDAY. THERMAL PROFILES ARE COLD ENOUGH FOR SNOW TO THE NORTHWEST
OF THE I-95 CORRIDOR...BUT THE BEST LIFT IS FOCUSED JUST SOUTHEAST
OF THIS AREA...AND THE SYSTEM COULD TRACK FURTHER TO THE SOUTH PER
12Z UKMET MODEL. STILL A LOT OF UNCERTAINTY WITH ULTIMATE TRACK.

WEDNESDAY...
A MID-LEVEL RIDGE WILL MOVE THROUGH THE REGION TUESDAY NIGHT INTO
EARLY WEDNESDAY LEADING TO A BRIEF RESPITE BETWEEN WEATHER SYSTEMS.
THEN A MID-LEVEL TROUGH IS PROJECTED TO BECOME NEGATIVELY TILTED
OVER THE OHIO VALLEY ON WED...LEADING TO A MERIDIONAL FLOW ALONG
THE EAST COAST...WITH THE ENTIRE COLUMN EXPECTED TO BE WELL ABOVE
FREEZING ACROSS THE CWA FAVORING A RAIN EVENT. THERE ARE SEVERAL
INGREDIENTS COMING TOGETHER FOR HEAVY RAIN. IN PARTICULAR...DEEP
GULF MOISTURE...LOW-LEVEL ISENTROPIC LIFT...MID-LEVEL PVA...AND
THE RIGHT-REAR QUADRANT OF A 140 KNOT UPPER-LEVEL JET JUST NORTH.
THE SYSTEM SHOULD BE FAIRLY PROGRESSIVE BUT WILL HAVE TO MONITOR
POTENTIAL FOR FLOODING.

THU AND FRI...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS
TO BUILD IN. TEMPERATURES WILL RETURN TO SEASONABLE LEVELS AND
THERE COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THE 00Z TAFS TAKE CIGS DOWN TO MVFR LEVELS TONIGHT FROM THE KPHL
AREA AIRPORTS NORTHWESTWARD WITH IMPROVEMENT ON SATURDAY. ITS BEEN
TOUGH TO SHAKE THIS STRATOCU LEVEL CLOUDINESS PATTERN.

FOR TONIGHT. LOW CLOUDS ADVANCING IN FROM THE HIGHER TERRAIN
AIRPORTS ARE STILL HEADING INTO THE TERMINALS. WE BRING MVFR CIG
POTENTIAL FROM THE GET GO AT KABE AND KRDG (HIER CONFIDENCE
OVERNIGHT) AND BRING IT DOWN TO THE KPHL METRO AIRPORTS AFTER 05Z.
WE LEAVE KACY AND KMIV VFR. WINDS WILL BE LIGHT FROM THE
NORTHWEST. NO VSBY RESTRICTIONS EXPECTED.

ON SATURDAY, PREDICTING THE MVFR CIG TO BECOME SCATTERED DURING
THE MORNING FROM THE KPHL METRO AIRPORTS NWWD WITH A CIRRUS CIG
ABOVE. KACY AND KMIV NOT EXPECTING A MVFR CIG. IT WILL BE A WEAK
PRESSURE PATTERN AND WINDS WILL BE LIGHT. A NORTHERLY DIRECTION
IS FAVORED, BUT SPEEDS ARE EXPECTED TO REMAIN BELOW 10 KNOTS,
PROBABLY PREDOMINATELY LESS THAN 6 KNOTS AT SOME OF THE MORE
RURAL AIRPORTS AND TERMINALS.

OUTLOOK...
SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED.
MONDAY AND TUESDAY...IFR POSSIBLE IN SHRA AND SHSN.
WEDNESDAY...IFR POSSIBLE IN RAIN AND FOG.

&&

.MARINE...
SUB-SCA CONDS ARE EXPECTED FOR THE NEXT 24 HOURS AT LEAST. SMWHT
GUST NW WINDS THIS EVENING WILL GRADUALLY DIMINISH TONIGHT THROUGH
SATURDAY AS A RIDGE OF HIGH PRES MOVES OVERHEAD. SEAS ARE
CURRENTLY RUNNING 2 TO 3 FT BUT THEY SHOULD GRADUALLY DIMINISH
ALSO.

OUTLOOK...
SUNDAY AND MONDAY...SUB-SCA CONDITIONS EXPECTED.
TUESDAY...SCA MAY BE NEEDED FOR BUILDING SEAS.
WEDNESDAY...GALE WARNING MAY BE NEEDED.

&&

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

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...GIGI
SHORT TERM...AMC
LONG TERM...FRANCK
AVIATION...FRANCK/GIGI
MARINE...AMC/FRANCK







000
FXUS61 KPHI 200240
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
940 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE JUST NORTH OF LAKE HURON WILL GRADUALLY MOVE
EASTWARD INTO NORTHERN NEW ENGLAND THRU MONDAY. A WAVE OF LOW
PRESSURE WILL FORM ALONG THE MID-ATLANTIC COASTLINE ON MONDAY AND
MOVE NORTHEASTWARD JUST OFFSHORE ON TUESDAY. A STRONG AREA OF
LOW PRESSURE WILL THEN FORM OVER THE MISSISSIPPI VALLEY AND MOVE
THRU THE GREAT LAKES REGION DURING THE MIDDLE OF THE
WEEK, BRINGING A STRONG COLD FRONT THRU THE REGION BY THURSDAY.
HIGH PRESSURE IS PROJECTED TO BUILD IN ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LOW CLOUDS STILL WORKING THEIR WAY SOUTHWARD DEEPER INTO OUR CWA.
IT DOES FEEL LIKE WE ARE STUCK IN THE STRATOCUMULUS VERSION OF
GROUND HOG DAY. OVERNIGHT THERE IS A LOW LEVEL VORT MAX THAT IS
KEEPING THE LOW CLOUDS PERPETUATING AND JUST ENOUGH OF AN
INVERSION TO GIVE THEM A COMFORT LEVEL. IT LOOKS TO TAKE MOST OF
THE OVERNIGHT FOR THIS TO FEATURE TO CLEAR. LATER AT NIGHT SOME OF
THE CIRRUS FROM THE ONCE FORMIDABLE LOOKING SOUTHERN STREAM SYSTEM
WILL ALSO REACH OUR CWA.

OUR ADJUSTMENT WAS TO INCREASE CLOUD COVERAGE, ESP NORTH AND BUMP
UP MIN TEMPS THERE. IN THE SOUTHERN HALF OF OUR CWA, THE SHORT
WAVE TRAJ BYPASSES IT, SO WE WENT WITH A PTLY CLDY NIGHT. WINDS
ARE LIGHT ENOUGH THAT WE KEPT RADIATING MINS IN THE NJ PINE
BARRENS AND INTERIOR DELMARVA. THERE WILL BE SOME FROST SCRAPING
COME SATURDAY MORNING IN THOSE AREAS.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
FOR SATURDAY...HIGH PRES CENTERED OVER CANADA SHIFTS EWD FROM
ONTARIO INTO QUEBEC. A RIDGE AXIS IS FCST TO EXTEND SWD THROUGH THE
MID-ATLANTIC REGION RESULTING IN ONLY LIGHT NLY WINDS. SOME LOW-LVL
MOISTURE SHOULD REMAIN TRAPPED BELOW THE LARGE-SCALE SUBSIDENCE
INVERSION BUT HARD TO SAY HOW EXTENSIVE ANY LOW CLOUDS MAY BE. THE
12-KM NAM SHOWS A THIN LOW CLOUD LAYER DEVELOPING DURG THE DAY BUT
HIGHER-RES ARW/NMM AND THE GFS DO NOT. THERE WILL BE SOME HIGHER
CLOUDS ALSO ASSOCD WITH THE SHRTWV NOW MOVING ENEWD OUT OF THE SRN
PLAINS...HWVR POPS REMAIN NEAR ZERO.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* SLIGHT CHANCE OF SNOW SHOWERS SUNDAY MORNING MAINLY NORTH.
* SNOW POSSIBLE NORTHWEST OF THE I-95 CORRIDOR LATE MONDAY
  THRU EARLY TUESDAY.
* POTENTIAL FOR HEAVY RAIN INCREASING ON CHRISTMAS EVE DAY.

OVERVIEW...

MID-LEVEL BLOCKING PATTERN OVER NOAM BEGINS TO DISLODGE IN RESPONSE
JET ENERGY MOVING INTO THE PACIFIC NORTHWEST THIS WEEKEND...CARVING
OUT A DEEP TROUGH OVER THE MS VALLEY EARLY EARLY NEXT WEEK...WHICH
LEADS TO INCLEMENT WEATHER IN THE TUESDAY THRU WEDNESDAY TIME FRAME.

DETAILS...

SUNDAY...
SHORTWAVE LIFTING THROUGH THE REGION EARLY IN THE DAY MAY GENERATE
ENOUGH LIFT ALONG WITH MARGINAL MOISTURE IN THE COLUMN TO PRODUCE
SOME LIGHT SNOW SHOWERS...MAINLY DURING THE PRE-DAWN HOURS. LITTLE
IF ANY ACCUMULATION EXPECTED AS MOISTURE IS VERY LIMITED. RIDGING
THEN BUILDS IN SO FAIR WEATHER IS EXPECTED THE REMAINDER OF THE DAY.

MONDAY AND TUESDAY...
HIGH PRESSURE ANCHORS ALONG THE LEE OF THE APPALACHIANS. A SOUTHERN
STREAM SHORTWAVE WILL INDUCE LOW-PRESSURE OF THE MID-ATLANTIC COAST.
MODELS BRING QPF NORTHWARD INTO THE AREA ON MONDAY NIGHT INTO EARLY
TUESDAY. THERMAL PROFILES ARE COLD ENOUGH FOR SNOW TO THE NORTHWEST
OF THE I-95 CORRIDOR...BUT THE BEST LIFT IS FOCUSED JUST SOUTHEAST
OF THIS AREA...AND THE SYSTEM COULD TRACK FURTHER TO THE SOUTH PER
12Z UKMET MODEL. STILL A LOT OF UNCERTAINTY WITH ULTIMATE TRACK.

WEDNESDAY...
A MID-LEVEL RIDGE WILL MOVE THROUGH THE REGION TUESDAY NIGHT INTO
EARLY WEDNESDAY LEADING TO A BRIEF RESPITE BETWEEN WEATHER SYSTEMS.
THEN A MID-LEVEL TROUGH IS PROJECTED TO BECOME NEGATIVELY TILTED
OVER THE OHIO VALLEY ON WED...LEADING TO A MERIDIONAL FLOW ALONG
THE EAST COAST...WITH THE ENTIRE COLUMN EXPECTED TO BE WELL ABOVE
FREEZING ACROSS THE CWA FAVORING A RAIN EVENT. THERE ARE SEVERAL
INGREDIENTS COMING TOGETHER FOR HEAVY RAIN. IN PARTICULAR...DEEP
GULF MOISTURE...LOW-LEVEL ISENTROPIC LIFT...MID-LEVEL PVA...AND
THE RIGHT-REAR QUADRANT OF A 140 KNOT UPPER-LEVEL JET JUST NORTH.
THE SYSTEM SHOULD BE FAIRLY PROGRESSIVE BUT WILL HAVE TO MONITOR
POTENTIAL FOR FLOODING.

THU AND FRI...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS
TO BUILD IN. TEMPERATURES WILL RETURN TO SEASONABLE LEVELS AND
THERE COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THE 00Z TAFS TAKE CIGS DOWN TO MVFR LEVELS TONIGHT FROM THE KPHL
AREA AIRPORTS NORTHWESTWARD WITH IMPROVEMENT ON SATURDAY. ITS BEEN
TOUGH TO SHAKE THIS STRATOCU LEVEL CLOUDINESS PATTERN.

FOR TONIGHT. LOW CLOUDS ADVANCING IN FROM THE HIGHER TERRAIN
AIRPORTS ARE STILL HEADING INTO THE TERMINALS. WE BRING MVFR CIG
POTENTIAL FROM THE GET GO AT KABE AND KRDG (HIER CONFIDENCE
OVERNIGHT) AND BRING IT DOWN TO THE KPHL METRO AIRPORTS AFTER 05Z.
WE LEAVE KACY AND KMIV VFR. WINDS WILL BE LIGHT FROM THE
NORTHWEST. NO VSBY RESTRICTIONS EXPECTED.

ON SATURDAY, PREDICTING THE MVFR CIG TO BECOME SCATTERED DURING
THE MORNING FROM THE KPHL METRO AIRPORTS NWWD WITH A CIRRUS CIG
ABOVE. KACY AND KMIV NOT EXPECTING A MVFR CIG. IT WILL BE A WEAK
PRESSURE PATTERN AND WINDS WILL BE LIGHT. A NORTHERLY DIRECTION
IS FAVORED, BUT SPEEDS ARE EXPECTED TO REMAIN BELOW 10 KNOTS,
PROBABLY PREDOMINATELY LESS THAN 6 KNOTS AT SOME OF THE MORE
RURAL AIRPORTS AND TERMINALS.

OUTLOOK...
SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED.
MONDAY AND TUESDAY...IFR POSSIBLE IN SHRA AND SHSN.
WEDNESDAY...IFR POSSIBLE IN RAIN AND FOG.

&&

.MARINE...
SUB-SCA CONDS ARE EXPECTED FOR THE NEXT 24 HOURS AT LEAST. SMWHT
GUST NW WINDS THIS EVENING WILL GRADUALLY DIMINISH TONIGHT THROUGH
SATURDAY AS A RIDGE OF HIGH PRES MOVES OVERHEAD. SEAS ARE
CURRENTLY RUNNING 2 TO 3 FT BUT THEY SHOULD GRADUALLY DIMINISH
ALSO.

OUTLOOK...
SUNDAY AND MONDAY...SUB-SCA CONDITIONS EXPECTED.
TUESDAY...SCA MAY BE NEEDED FOR BUILDING SEAS.
WEDNESDAY...GALE WARNING MAY BE NEEDED.

&&

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

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...GIGI
SHORT TERM...AMC
LONG TERM...FRANCK
AVIATION...FRANCK/GIGI
MARINE...AMC/FRANCK







000
FXUS61 KPHI 200240
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
940 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE JUST NORTH OF LAKE HURON WILL GRADUALLY MOVE
EASTWARD INTO NORTHERN NEW ENGLAND THRU MONDAY. A WAVE OF LOW
PRESSURE WILL FORM ALONG THE MID-ATLANTIC COASTLINE ON MONDAY AND
MOVE NORTHEASTWARD JUST OFFSHORE ON TUESDAY. A STRONG AREA OF
LOW PRESSURE WILL THEN FORM OVER THE MISSISSIPPI VALLEY AND MOVE
THRU THE GREAT LAKES REGION DURING THE MIDDLE OF THE
WEEK, BRINGING A STRONG COLD FRONT THRU THE REGION BY THURSDAY.
HIGH PRESSURE IS PROJECTED TO BUILD IN ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
LOW CLOUDS STILL WORKING THEIR WAY SOUTHWARD DEEPER INTO OUR CWA.
IT DOES FEEL LIKE WE ARE STUCK IN THE STRATOCUMULUS VERSION OF
GROUND HOG DAY. OVERNIGHT THERE IS A LOW LEVEL VORT MAX THAT IS
KEEPING THE LOW CLOUDS PERPETUATING AND JUST ENOUGH OF AN
INVERSION TO GIVE THEM A COMFORT LEVEL. IT LOOKS TO TAKE MOST OF
THE OVERNIGHT FOR THIS TO FEATURE TO CLEAR. LATER AT NIGHT SOME OF
THE CIRRUS FROM THE ONCE FORMIDABLE LOOKING SOUTHERN STREAM SYSTEM
WILL ALSO REACH OUR CWA.

OUR ADJUSTMENT WAS TO INCREASE CLOUD COVERAGE, ESP NORTH AND BUMP
UP MIN TEMPS THERE. IN THE SOUTHERN HALF OF OUR CWA, THE SHORT
WAVE TRAJ BYPASSES IT, SO WE WENT WITH A PTLY CLDY NIGHT. WINDS
ARE LIGHT ENOUGH THAT WE KEPT RADIATING MINS IN THE NJ PINE
BARRENS AND INTERIOR DELMARVA. THERE WILL BE SOME FROST SCRAPING
COME SATURDAY MORNING IN THOSE AREAS.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
FOR SATURDAY...HIGH PRES CENTERED OVER CANADA SHIFTS EWD FROM
ONTARIO INTO QUEBEC. A RIDGE AXIS IS FCST TO EXTEND SWD THROUGH THE
MID-ATLANTIC REGION RESULTING IN ONLY LIGHT NLY WINDS. SOME LOW-LVL
MOISTURE SHOULD REMAIN TRAPPED BELOW THE LARGE-SCALE SUBSIDENCE
INVERSION BUT HARD TO SAY HOW EXTENSIVE ANY LOW CLOUDS MAY BE. THE
12-KM NAM SHOWS A THIN LOW CLOUD LAYER DEVELOPING DURG THE DAY BUT
HIGHER-RES ARW/NMM AND THE GFS DO NOT. THERE WILL BE SOME HIGHER
CLOUDS ALSO ASSOCD WITH THE SHRTWV NOW MOVING ENEWD OUT OF THE SRN
PLAINS...HWVR POPS REMAIN NEAR ZERO.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* SLIGHT CHANCE OF SNOW SHOWERS SUNDAY MORNING MAINLY NORTH.
* SNOW POSSIBLE NORTHWEST OF THE I-95 CORRIDOR LATE MONDAY
  THRU EARLY TUESDAY.
* POTENTIAL FOR HEAVY RAIN INCREASING ON CHRISTMAS EVE DAY.

OVERVIEW...

MID-LEVEL BLOCKING PATTERN OVER NOAM BEGINS TO DISLODGE IN RESPONSE
JET ENERGY MOVING INTO THE PACIFIC NORTHWEST THIS WEEKEND...CARVING
OUT A DEEP TROUGH OVER THE MS VALLEY EARLY EARLY NEXT WEEK...WHICH
LEADS TO INCLEMENT WEATHER IN THE TUESDAY THRU WEDNESDAY TIME FRAME.

DETAILS...

SUNDAY...
SHORTWAVE LIFTING THROUGH THE REGION EARLY IN THE DAY MAY GENERATE
ENOUGH LIFT ALONG WITH MARGINAL MOISTURE IN THE COLUMN TO PRODUCE
SOME LIGHT SNOW SHOWERS...MAINLY DURING THE PRE-DAWN HOURS. LITTLE
IF ANY ACCUMULATION EXPECTED AS MOISTURE IS VERY LIMITED. RIDGING
THEN BUILDS IN SO FAIR WEATHER IS EXPECTED THE REMAINDER OF THE DAY.

MONDAY AND TUESDAY...
HIGH PRESSURE ANCHORS ALONG THE LEE OF THE APPALACHIANS. A SOUTHERN
STREAM SHORTWAVE WILL INDUCE LOW-PRESSURE OF THE MID-ATLANTIC COAST.
MODELS BRING QPF NORTHWARD INTO THE AREA ON MONDAY NIGHT INTO EARLY
TUESDAY. THERMAL PROFILES ARE COLD ENOUGH FOR SNOW TO THE NORTHWEST
OF THE I-95 CORRIDOR...BUT THE BEST LIFT IS FOCUSED JUST SOUTHEAST
OF THIS AREA...AND THE SYSTEM COULD TRACK FURTHER TO THE SOUTH PER
12Z UKMET MODEL. STILL A LOT OF UNCERTAINTY WITH ULTIMATE TRACK.

WEDNESDAY...
A MID-LEVEL RIDGE WILL MOVE THROUGH THE REGION TUESDAY NIGHT INTO
EARLY WEDNESDAY LEADING TO A BRIEF RESPITE BETWEEN WEATHER SYSTEMS.
THEN A MID-LEVEL TROUGH IS PROJECTED TO BECOME NEGATIVELY TILTED
OVER THE OHIO VALLEY ON WED...LEADING TO A MERIDIONAL FLOW ALONG
THE EAST COAST...WITH THE ENTIRE COLUMN EXPECTED TO BE WELL ABOVE
FREEZING ACROSS THE CWA FAVORING A RAIN EVENT. THERE ARE SEVERAL
INGREDIENTS COMING TOGETHER FOR HEAVY RAIN. IN PARTICULAR...DEEP
GULF MOISTURE...LOW-LEVEL ISENTROPIC LIFT...MID-LEVEL PVA...AND
THE RIGHT-REAR QUADRANT OF A 140 KNOT UPPER-LEVEL JET JUST NORTH.
THE SYSTEM SHOULD BE FAIRLY PROGRESSIVE BUT WILL HAVE TO MONITOR
POTENTIAL FOR FLOODING.

THU AND FRI...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS
TO BUILD IN. TEMPERATURES WILL RETURN TO SEASONABLE LEVELS AND
THERE COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THE 00Z TAFS TAKE CIGS DOWN TO MVFR LEVELS TONIGHT FROM THE KPHL
AREA AIRPORTS NORTHWESTWARD WITH IMPROVEMENT ON SATURDAY. ITS BEEN
TOUGH TO SHAKE THIS STRATOCU LEVEL CLOUDINESS PATTERN.

FOR TONIGHT. LOW CLOUDS ADVANCING IN FROM THE HIGHER TERRAIN
AIRPORTS ARE STILL HEADING INTO THE TERMINALS. WE BRING MVFR CIG
POTENTIAL FROM THE GET GO AT KABE AND KRDG (HIER CONFIDENCE
OVERNIGHT) AND BRING IT DOWN TO THE KPHL METRO AIRPORTS AFTER 05Z.
WE LEAVE KACY AND KMIV VFR. WINDS WILL BE LIGHT FROM THE
NORTHWEST. NO VSBY RESTRICTIONS EXPECTED.

ON SATURDAY, PREDICTING THE MVFR CIG TO BECOME SCATTERED DURING
THE MORNING FROM THE KPHL METRO AIRPORTS NWWD WITH A CIRRUS CIG
ABOVE. KACY AND KMIV NOT EXPECTING A MVFR CIG. IT WILL BE A WEAK
PRESSURE PATTERN AND WINDS WILL BE LIGHT. A NORTHERLY DIRECTION
IS FAVORED, BUT SPEEDS ARE EXPECTED TO REMAIN BELOW 10 KNOTS,
PROBABLY PREDOMINATELY LESS THAN 6 KNOTS AT SOME OF THE MORE
RURAL AIRPORTS AND TERMINALS.

OUTLOOK...
SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED.
MONDAY AND TUESDAY...IFR POSSIBLE IN SHRA AND SHSN.
WEDNESDAY...IFR POSSIBLE IN RAIN AND FOG.

&&

.MARINE...
SUB-SCA CONDS ARE EXPECTED FOR THE NEXT 24 HOURS AT LEAST. SMWHT
GUST NW WINDS THIS EVENING WILL GRADUALLY DIMINISH TONIGHT THROUGH
SATURDAY AS A RIDGE OF HIGH PRES MOVES OVERHEAD. SEAS ARE
CURRENTLY RUNNING 2 TO 3 FT BUT THEY SHOULD GRADUALLY DIMINISH
ALSO.

OUTLOOK...
SUNDAY AND MONDAY...SUB-SCA CONDITIONS EXPECTED.
TUESDAY...SCA MAY BE NEEDED FOR BUILDING SEAS.
WEDNESDAY...GALE WARNING MAY BE NEEDED.

&&

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

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...GIGI
SHORT TERM...AMC
LONG TERM...FRANCK
AVIATION...FRANCK/GIGI
MARINE...AMC/FRANCK







000
FXUS61 KLWX 200230
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
930 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST THROUGH SUNDAY. LOW PRESSURE WILL
TRACK UP THE MID-ATLANTIC COAST MONDAY NIGHT. A STRONG COLD FRONT
WILL PASS THROUGH THE AREA WEDNESDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 02Z...1024MB WILL PERSIST OVER THE AREA THROUGH SUNDAY
NIGHT. CLEAR SKIES EAST OF THE ALLEGHENIES INTO LATE TONIGHT
BEFORE STRATUS SPREADS IN FROM THE SOUTHWEST AS AN UPPER-LEVEL
TROUGH APPROACHES FROM THE TENNESSEE VALLEY. TEMPS HAVE CRASHED
INTO THE 20S IN TYPICAL COOL SPOTS ...LOW 30S ELSEWHERE. MINS JUST
A FEW DEGREES LESS AS MIXING PERSISTS WITH 1027MB PRESSURE OVER
THE ERN OH VLY.

THE UPPER-LEVEL DISTURBANCE WILL PASS THROUGH THE REGION SATURDAY.
THIS WILL CAUSE SURFACE LOW PRESSURE TO DEVELOP OFF THE SOUTH
CAROLINA COAST...BUT IT WILL BE TOO FAR TO OUR SOUTH FOR ANY
PRECIPITATION. HOWEVER...MOSTLY CLOUDY SKIES ARE EXPECTED AS HIGH
AND MID-LEVEL CLOUDS PASS THROUGH WITH THE UPPER-LEVEL
DISTURBANCE. SEASONABLY CHILLY CONDITIONS WILL CONTINUE BUT WINDS
WILL BE LIGHT. MAX TEMPS WILL RANGE FROM THE UPPER 20S AND LOWER
30S IN THE ALLEGHENY HIGHLANDS TO THE LOWER AND MIDDLE 40S IN
CENTRAL VIRGINIA.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
LARGE SURFACE HIGH PRESSURE WILL EXTEND FROM SOUTHEASTERN CANADA
THROUGH THE MIDDLE ATLANTIC AND INTO THE SOUTHEASTERN CONUS SATURDAY
NIGHT. A WEAK UPPER TROUGH WILL MOVE THROUGH THE AREA...RESULTING IN
A MID-LEVEL CLOUD DECK OVER THE AREA. GIVEN THE CLOUD
COVER...FAVORED THE WARMER MET GUIDANCE FOR LOW TEMPS.  IT WILL BE A
COLD NIGHT...WITH LOWS IN THE 20S OVER NEARLY ALL OF THE FORECAST
AREA. DOWNTOWN AREAS OF BALTIMORE AND WASHINGTON MAY STAY AT OR JUST
ABOVE FREEZING OVERNIGHT.

THE HIGH WILL BE DIRECTLY OVERHEAD SUNDAY...WITH MOSTLY SUNNY SKIES
AND LIGHT WINDS. SOME DISCREPANCY AMONG MODELS AS TO WHETHER THE
RIDGE AXIS WILL MAKE IT TO THE DELMARVA BY THE AFTERNOON...WHICH
WOULD RESULT IN LIGHT RETURN FLOW ACROSS THE SOUTHERN AND WESTERN
COUNTIES OF THE CWA. HIGH EXPECTED TO BE IN THE MID TO UPPER 40S
ACROSS MOST OF THE CWA...WITH LOW 40S POSSIBLE NEAR THE MASON DIXON
LINE AND IN HIGHER ELEVATIONS.

ONLY GRADUAL EWD MOVEMENT IN THE RIDGE AXIS TOWARDS THE COAST SUNDAY
NIGHT. MODELS HAVE TRENDED SLOWER IN THE DEVELOPMENT OF LOW PRESSURE
ALONG THE SOUTHEAST COAST. REMOVED ALL POPS FROM THE CWA SUNDAY
NIGHT ACCORDINGLY. LOWS WILL BE SIMILAR TO SATURDAY NIGHT...IN THE
20S FOR MOST OF THE CWA AND A FEW SPOTS ABOVE 30 IN METRO
BALTIMORE/WASHINGTON.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
PVA MAX IN SOUTHERN FLOW WILL SUPPORT WIDESPREAD PRECIPITATION
ACROSS REGION MONDAY. ALTHOUGH MOST OF PRECIPITATION LOOKS TO LIQUID
IT APPEARS THAT ENOUGH COLD AIR IS IN PLACE FOR PRECIPITATION BEGIN
AS A WINTRY MIX EARLY MONDAY.

STRONG COLD FRONT SUPPORTED BY UPPER LEVEL CUT-OFF SOUTH OF THE
GREAT LAKES WILL CROSS THE MID ATLANTIC STATES BY WEDNESDAY. RAIN
WILL CHANGE OVER TO SNOW IN AREA AFFECTED BY MUCH COLDER AIR
STREAMING INTO REGION BEHIND THE LOW.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
NW FLOW 5-10 KT INTO LATE TONIGHT BEFORE DIMINISHING. HIGH
PRESSURE WILL BUILD OVER THE TERMINALS TONIGHT THROUGH SATURDAY.
VFR CONDITIONS WILL CONTINUE.

HIGH PRESSURE WILL BE DIRECTLY OVERHEAD SATURDAY NIGHT THROUGH
SUNDAY NIGHT. VFR CONDITIONS EXPECTED WITH LIGHT WINDS. LOW
PRESSURE MAY BRING PRECIPITATION AND SUBVFR CONDITIONS MONDAY AND
TUESDAY. A STRONG COLD MAY IMPACT THE TERMINALS WEDNESDAY.

&&

.MARINE...
SCA CANCELLED EARLY FOR GUSTS AROUND 15 KT THIS EVENING...EASING
THROUGH SATURDAY MORNING AS HIGH PRESSURE BUILDS OVERHEAD.

HIGH PRESSURE WILL BE DIRECTLY OVER THE WATERS SATURDAY NIGHT
THROUGH SUNDAY NIGHT. LIGHT NORTHERLY FLOW SATURDAY NIGHT AND
SUNDAY...SHIFTING TO THE E-NE SUNDAY NIGHT. LOW PRESSURE MAY
IMPACT THE WATERS MONDAY INTO TUESDAY BEFORE A STRONG COLD FRONT
PASSES THROUGH WEDNESDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

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






000
FXUS61 KLWX 200230
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
930 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST THROUGH SUNDAY. LOW PRESSURE WILL
TRACK UP THE MID-ATLANTIC COAST MONDAY NIGHT. A STRONG COLD FRONT
WILL PASS THROUGH THE AREA WEDNESDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 02Z...1024MB WILL PERSIST OVER THE AREA THROUGH SUNDAY
NIGHT. CLEAR SKIES EAST OF THE ALLEGHENIES INTO LATE TONIGHT
BEFORE STRATUS SPREADS IN FROM THE SOUTHWEST AS AN UPPER-LEVEL
TROUGH APPROACHES FROM THE TENNESSEE VALLEY. TEMPS HAVE CRASHED
INTO THE 20S IN TYPICAL COOL SPOTS ...LOW 30S ELSEWHERE. MINS JUST
A FEW DEGREES LESS AS MIXING PERSISTS WITH 1027MB PRESSURE OVER
THE ERN OH VLY.

THE UPPER-LEVEL DISTURBANCE WILL PASS THROUGH THE REGION SATURDAY.
THIS WILL CAUSE SURFACE LOW PRESSURE TO DEVELOP OFF THE SOUTH
CAROLINA COAST...BUT IT WILL BE TOO FAR TO OUR SOUTH FOR ANY
PRECIPITATION. HOWEVER...MOSTLY CLOUDY SKIES ARE EXPECTED AS HIGH
AND MID-LEVEL CLOUDS PASS THROUGH WITH THE UPPER-LEVEL
DISTURBANCE. SEASONABLY CHILLY CONDITIONS WILL CONTINUE BUT WINDS
WILL BE LIGHT. MAX TEMPS WILL RANGE FROM THE UPPER 20S AND LOWER
30S IN THE ALLEGHENY HIGHLANDS TO THE LOWER AND MIDDLE 40S IN
CENTRAL VIRGINIA.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
LARGE SURFACE HIGH PRESSURE WILL EXTEND FROM SOUTHEASTERN CANADA
THROUGH THE MIDDLE ATLANTIC AND INTO THE SOUTHEASTERN CONUS SATURDAY
NIGHT. A WEAK UPPER TROUGH WILL MOVE THROUGH THE AREA...RESULTING IN
A MID-LEVEL CLOUD DECK OVER THE AREA. GIVEN THE CLOUD
COVER...FAVORED THE WARMER MET GUIDANCE FOR LOW TEMPS.  IT WILL BE A
COLD NIGHT...WITH LOWS IN THE 20S OVER NEARLY ALL OF THE FORECAST
AREA. DOWNTOWN AREAS OF BALTIMORE AND WASHINGTON MAY STAY AT OR JUST
ABOVE FREEZING OVERNIGHT.

THE HIGH WILL BE DIRECTLY OVERHEAD SUNDAY...WITH MOSTLY SUNNY SKIES
AND LIGHT WINDS. SOME DISCREPANCY AMONG MODELS AS TO WHETHER THE
RIDGE AXIS WILL MAKE IT TO THE DELMARVA BY THE AFTERNOON...WHICH
WOULD RESULT IN LIGHT RETURN FLOW ACROSS THE SOUTHERN AND WESTERN
COUNTIES OF THE CWA. HIGH EXPECTED TO BE IN THE MID TO UPPER 40S
ACROSS MOST OF THE CWA...WITH LOW 40S POSSIBLE NEAR THE MASON DIXON
LINE AND IN HIGHER ELEVATIONS.

ONLY GRADUAL EWD MOVEMENT IN THE RIDGE AXIS TOWARDS THE COAST SUNDAY
NIGHT. MODELS HAVE TRENDED SLOWER IN THE DEVELOPMENT OF LOW PRESSURE
ALONG THE SOUTHEAST COAST. REMOVED ALL POPS FROM THE CWA SUNDAY
NIGHT ACCORDINGLY. LOWS WILL BE SIMILAR TO SATURDAY NIGHT...IN THE
20S FOR MOST OF THE CWA AND A FEW SPOTS ABOVE 30 IN METRO
BALTIMORE/WASHINGTON.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
PVA MAX IN SOUTHERN FLOW WILL SUPPORT WIDESPREAD PRECIPITATION
ACROSS REGION MONDAY. ALTHOUGH MOST OF PRECIPITATION LOOKS TO LIQUID
IT APPEARS THAT ENOUGH COLD AIR IS IN PLACE FOR PRECIPITATION BEGIN
AS A WINTRY MIX EARLY MONDAY.

STRONG COLD FRONT SUPPORTED BY UPPER LEVEL CUT-OFF SOUTH OF THE
GREAT LAKES WILL CROSS THE MID ATLANTIC STATES BY WEDNESDAY. RAIN
WILL CHANGE OVER TO SNOW IN AREA AFFECTED BY MUCH COLDER AIR
STREAMING INTO REGION BEHIND THE LOW.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
NW FLOW 5-10 KT INTO LATE TONIGHT BEFORE DIMINISHING. HIGH
PRESSURE WILL BUILD OVER THE TERMINALS TONIGHT THROUGH SATURDAY.
VFR CONDITIONS WILL CONTINUE.

HIGH PRESSURE WILL BE DIRECTLY OVERHEAD SATURDAY NIGHT THROUGH
SUNDAY NIGHT. VFR CONDITIONS EXPECTED WITH LIGHT WINDS. LOW
PRESSURE MAY BRING PRECIPITATION AND SUBVFR CONDITIONS MONDAY AND
TUESDAY. A STRONG COLD MAY IMPACT THE TERMINALS WEDNESDAY.

&&

.MARINE...
SCA CANCELLED EARLY FOR GUSTS AROUND 15 KT THIS EVENING...EASING
THROUGH SATURDAY MORNING AS HIGH PRESSURE BUILDS OVERHEAD.

HIGH PRESSURE WILL BE DIRECTLY OVER THE WATERS SATURDAY NIGHT
THROUGH SUNDAY NIGHT. LIGHT NORTHERLY FLOW SATURDAY NIGHT AND
SUNDAY...SHIFTING TO THE E-NE SUNDAY NIGHT. LOW PRESSURE MAY
IMPACT THE WATERS MONDAY INTO TUESDAY BEFORE A STRONG COLD FRONT
PASSES THROUGH WEDNESDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

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







000
FXUS61 KPBZ 200225
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
925 PM EST FRI DEC 19 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WITH 930PM UPDATE...INCREASED SKY COVER OVERNIGHT AS WELL AS
MAKING MINOR ADJUSTMENTS TO OVERNIGHT TEMPERATURES. WHILE STRATUS
SCATTERED OUT SOMEWHAT EARLIER THIS EVENING NEAR FRANKLIN AND
DUBOIS...THIS GAP HAS FILLED BACK IN...AND DO NOT EXPECT MUCH IF
ANY ADDITIONAL CLEARING THIS EVENING. AS A RESULT...TEMPERATURES
FELL SLIGHTLY MORE TO THE NORTH WITH THE REST OF THE REGION
STAYING A BIT WARMER. HAVE REFLECTED THAT TREND IN THE OVERNIGHT
LOWS...ALTHOUGH THIS SHOULD NOT CHANGE VALUES BY MORE THAN A
COUPLE DEGREES.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
HIGH PRESSURE RIDGE WILL SETTLE OVER THE NORTHEASTERN CONUS FOR
MUCH OF THE WEEKEND. A FAST MOVING SYSTEM WILL BE SUPPRESSED TO
THE SOUTH SATURDAY BUT SOME MID-HIGH DECK MAY REPLACE THE LOW
DECK...MAINTAINING MOSTLY CLOUDY SKIES THROUGH MUCH OF THE DAY.
WITH NEARLY STAGNANT 850HPA TEMPERATURES AND MINIMAL SUN
TOMORROW...EXPECT HIGHS WILL NOT SURPASS THE LOW TO MID 30`S.
HOWEVER...SOUTHERLY FLOW AND WARM ADVECTION WILL RETURN FOR SUNDAY
AND MONDAY BRINGING TEMPERATURES TO NEAR OR JUST ABOVE NORMAL
VALUES.

ON MONDAY...WE WILL BE IN THE SQUEEZE BETWEEN TWO SYSTEMS. ONE LOW
WILL BE DEVELOPING ALONG THE GULF COAST...WHILE ANOTHER LOW AND
DEEPENING UPPER TROUGH WILL SINK SOUTHWARD OVER THE CENTRAL US.
THIS LOW OVER THE CENTRAL PLAINS WILL HELP TO AMPLIFY THE UPPER
PATTERN...EJECTING THE SOUTHERN SYSTEM NORTHWARD. AT THIS POINT
THE BULK OF THE MOISTURE WITH THE SOUTHERN SYSTEM SHOULD REMAIN
EAST...JUST BRUSHING OUR EASTERN MOUNTAINS OF WV/MD UNTIL THE COLD
FRONT WITH THE DEEPENING LOW APPROACHES. MAINTAINED CHANCE POPS
FOR THE RIDGES WITH LOWER POPS FURTHER NORTH AND WEST THROUGH
MONDAY. WHILE THE MID LEVELS WILL BE WARMING...CANNOT RULE OUT A
RAIN/SNOW MIX INITIALLY MONDAY MORNING OVER THE RIDGES BEFORE
CHANGING TO ALL RAIN. SOME FREEZING RAIN COULD ALSO BE OF CONCERN
IN ANY SHELTERED VALLEYS...BUT FOR NOW WILL LEAVE THIS OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS ARE IN GENERAL AGREEMENT ON DEEPENING UPPER LEVEL CLOSED LOW
OVER THE GREAT LAKES TUESDAY THROUGH THURSDAY WITH PERIODS OF RAIN
INTO WEDNESDAY UNTIL COLD FRONT WILL CHANGE PRECIP OVER TO SNOW
SHOWERS LATER WEDNESDAY AND THURSDAY. WINDS WILL BE ON THE
INCREASE THURSDAY AS SURFACE LOW WRAPS UP NORTH OF THE REGION. QPF
ON THE FRONT SIDE OF SYSTEM WILL BE NEAR AN INCH...WHICH SHOULD
NOT PRODUCE ANY SIGNIFICANT PROBLEMS. BACKLASH SNOW WEDNESDAY
NIGHT INTO THURSDAY WILL BE LIGHT WITH ONLY MINOR ACCUMULATIONS
EXPECTED. FLOW BEHIND COLD FRONT LOOKS TO STAY SOUTHWESTERLY WHICH
LOOKS TO LIMIT LAKE ENHANCED AMOUNTS ALONG I-80 AND THE RIDGES.
COLDER TEMPERATURES WILL THEN MODERATE FRIDAY AS MID LEVEL FLOW
QUICKLY BECOMES ZONAL.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
PERVASIVE STRATUS COVERS ALL SITES THIS EVENING...WHILE BOUNDARY
LAYER MOISTURE HAS DROPPED OFF FROM EARLIER TODAY. GIVEN STRONG
INVERSIONS...STRATUS SEEMS LIKELY TO CONTINUE FOR THE NEXT DAY AT
LEAST...HOWEVER GIVEN A BIT WIDER DEWPOINT DEPRESSIONS...LIGHT
PRECIPITATION CHANCES SEEM VERY LOW. MVFR CONDITIONS SEEM LIKELY
TO CONTINUE. FRIES


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$







000
FXUS61 KPBZ 200225
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
925 PM EST FRI DEC 19 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WITH 930PM UPDATE...INCREASED SKY COVER OVERNIGHT AS WELL AS
MAKING MINOR ADJUSTMENTS TO OVERNIGHT TEMPERATURES. WHILE STRATUS
SCATTERED OUT SOMEWHAT EARLIER THIS EVENING NEAR FRANKLIN AND
DUBOIS...THIS GAP HAS FILLED BACK IN...AND DO NOT EXPECT MUCH IF
ANY ADDITIONAL CLEARING THIS EVENING. AS A RESULT...TEMPERATURES
FELL SLIGHTLY MORE TO THE NORTH WITH THE REST OF THE REGION
STAYING A BIT WARMER. HAVE REFLECTED THAT TREND IN THE OVERNIGHT
LOWS...ALTHOUGH THIS SHOULD NOT CHANGE VALUES BY MORE THAN A
COUPLE DEGREES.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
HIGH PRESSURE RIDGE WILL SETTLE OVER THE NORTHEASTERN CONUS FOR
MUCH OF THE WEEKEND. A FAST MOVING SYSTEM WILL BE SUPPRESSED TO
THE SOUTH SATURDAY BUT SOME MID-HIGH DECK MAY REPLACE THE LOW
DECK...MAINTAINING MOSTLY CLOUDY SKIES THROUGH MUCH OF THE DAY.
WITH NEARLY STAGNANT 850HPA TEMPERATURES AND MINIMAL SUN
TOMORROW...EXPECT HIGHS WILL NOT SURPASS THE LOW TO MID 30`S.
HOWEVER...SOUTHERLY FLOW AND WARM ADVECTION WILL RETURN FOR SUNDAY
AND MONDAY BRINGING TEMPERATURES TO NEAR OR JUST ABOVE NORMAL
VALUES.

ON MONDAY...WE WILL BE IN THE SQUEEZE BETWEEN TWO SYSTEMS. ONE LOW
WILL BE DEVELOPING ALONG THE GULF COAST...WHILE ANOTHER LOW AND
DEEPENING UPPER TROUGH WILL SINK SOUTHWARD OVER THE CENTRAL US.
THIS LOW OVER THE CENTRAL PLAINS WILL HELP TO AMPLIFY THE UPPER
PATTERN...EJECTING THE SOUTHERN SYSTEM NORTHWARD. AT THIS POINT
THE BULK OF THE MOISTURE WITH THE SOUTHERN SYSTEM SHOULD REMAIN
EAST...JUST BRUSHING OUR EASTERN MOUNTAINS OF WV/MD UNTIL THE COLD
FRONT WITH THE DEEPENING LOW APPROACHES. MAINTAINED CHANCE POPS
FOR THE RIDGES WITH LOWER POPS FURTHER NORTH AND WEST THROUGH
MONDAY. WHILE THE MID LEVELS WILL BE WARMING...CANNOT RULE OUT A
RAIN/SNOW MIX INITIALLY MONDAY MORNING OVER THE RIDGES BEFORE
CHANGING TO ALL RAIN. SOME FREEZING RAIN COULD ALSO BE OF CONCERN
IN ANY SHELTERED VALLEYS...BUT FOR NOW WILL LEAVE THIS OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS ARE IN GENERAL AGREEMENT ON DEEPENING UPPER LEVEL CLOSED LOW
OVER THE GREAT LAKES TUESDAY THROUGH THURSDAY WITH PERIODS OF RAIN
INTO WEDNESDAY UNTIL COLD FRONT WILL CHANGE PRECIP OVER TO SNOW
SHOWERS LATER WEDNESDAY AND THURSDAY. WINDS WILL BE ON THE
INCREASE THURSDAY AS SURFACE LOW WRAPS UP NORTH OF THE REGION. QPF
ON THE FRONT SIDE OF SYSTEM WILL BE NEAR AN INCH...WHICH SHOULD
NOT PRODUCE ANY SIGNIFICANT PROBLEMS. BACKLASH SNOW WEDNESDAY
NIGHT INTO THURSDAY WILL BE LIGHT WITH ONLY MINOR ACCUMULATIONS
EXPECTED. FLOW BEHIND COLD FRONT LOOKS TO STAY SOUTHWESTERLY WHICH
LOOKS TO LIMIT LAKE ENHANCED AMOUNTS ALONG I-80 AND THE RIDGES.
COLDER TEMPERATURES WILL THEN MODERATE FRIDAY AS MID LEVEL FLOW
QUICKLY BECOMES ZONAL.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
PERVASIVE STRATUS COVERS ALL SITES THIS EVENING...WHILE BOUNDARY
LAYER MOISTURE HAS DROPPED OFF FROM EARLIER TODAY. GIVEN STRONG
INVERSIONS...STRATUS SEEMS LIKELY TO CONTINUE FOR THE NEXT DAY AT
LEAST...HOWEVER GIVEN A BIT WIDER DEWPOINT DEPRESSIONS...LIGHT
PRECIPITATION CHANCES SEEM VERY LOW. MVFR CONDITIONS SEEM LIKELY
TO CONTINUE. FRIES


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$






000
FXUS61 KAKQ 200037
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
737 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST LATE TONIGHT THROUGH SATURDAY NIGHT. 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 COAST LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH SATURDAY/...
LATEST SFC ANALYSIS DEPICTS ~995 MB LO PRES OVER THE CANADIAN
MARITIMES WITH BROAD ~1028 MB HI PRES CENTERED OVER THE MIDWEST...RIDGING
ESE INTO THE MID ATLC STATES. WEAK LOW PRESSURE IS ALSO DEVELOPING
ACRS THE WRN GULF OF MEXICO...WITH PRECIP OVER LA/MS/AL AS OF 20Z
THIS AFTN. STILL MAINLY CLEAR SKIES OVER THE AKQ FORECAST AREA...BUT
SOME HIGH CIRRUS HAS STARTED TO OVERSPREAD THE REGION FROM THE SW
(AND BKN/OVC STRATO-CU HAS BEEN SLOW TO ERODE OVER THE ERN SHORE.
CURRENT TEMPS ARE GENLY IN THE 40S...AS CHILLY AS THE UPPER 30S AT
KWAL/KOXB IN THE CLOUDS...AND AS WARM AS AROUND 50 OVER NE NC AND
SOUTH CENTRAL VA.

FOR TONIGHT...DRY WX WILL PERSIST EVEN AS HIGH CLOUDS GRADUALLY
THICKEN/LOWER OVERNIGHT. EXPECT TEMPS TO RAPIDLY DROP AFTER SUNSET
UNDER MAINLY CLEAR SKIES...THEN BECOME NEARLY STEADY OVERNIGHT AS
CLOUDS SLOWLY INCREASE. LOWS MID 20S TO LOWER 30S.

SAT...SYSTEM FROM THE GULF CONTINUES TO REMAIN SHUNTED OFF TO OUR
SOUTH AS MID LEVEL FLOW REMAINS FAIRLY ZONAL. NAM/GFS STILL SHOW
SOME FORCING ALOFT MAKING WAY INTO PIEDMONT BETWEEN 12-18Z/SAT AND
BUFKIT SOUNDINGS SHOW SOME MODEST LIFT THROUGH THE DENDRITIC
GROWTH LAYER. PTYPE ACRS THE PIEDMONT WOULD TEND TO BE SNOW/SLEET
SAT AM ALTHOUGH SFC TEMPS SHOULD BE ABOVE 32 F (SFC WET BULBS IN
THE UPPER 20S INITIALLY). LOW LEVELS REMAIN QUITE DRY HOWEVER...SO ANY
PRECIP WILL BE VERY LIGHT (GENLY A FEW HUNDREDTHS IF THAT...WITH A
TRACE MORE LIKELY). THUS...WILL ONLY GO WITH 30% POPS AT MOST. BY
LATE MORNING/EARLY AFTN...AREA OF FORCING OVER THE PIEDMONT/CENTRAL
VA WEAKENS AS THE SFC LOW PUSHES OFF THE SE COAST. WILL CARRY LOW
CHC POPS IN FAR SE ZONES (ALL RAIN) THROUGH THE AFTN (ALTHOUGH
MOST OF THE PRECIP SHOULD STAY S OF THE CWA). CLOUDY TO MSTLY
CLOUDY W/ HIGHS GENLY 40-45 F SAT.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
SFC HIGH PRESSURE NOSES SOUTH INTO THE REGION SAT NIGHT/SUN...WITH DRY
CONDS THEN FOR SAT NGT AND SUN. LOWS IN THE 20S N TO THE 30S SE
SAT NIGHT...WITH HIGHS MAINLY FROM 45-50 F ON SUN. NEXT SYSTEM...THIS
ONE MORE AMPLIFIED WILL AFFECT THE AREA ON MON...WITH LIKELY POPS
ALL ZONES BY LATE MON AM/MON AFTN. LOOKS LIKE ALL RAIN ASIDE FROM
A BRIEF MIX POSSIBLE AT ONSET IN FAR NW COUNTIES. HIGHS MON ONLY
AROUND 40 F 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 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 /01Z SATURDAY THROUGH WEDNESDAY/...
STRATUS THAT WAS OVER THE LOWER EASTERN SHORE FRIDAY AFTN APPEAR TO
BE MOVING OFFSHORE. A SURFACE LOW NEAR THE GULF COAST AND AN UPPER
LEVEL DISTURBANCE THAT WILL MOVE ACROSS THE MID ATLANTIC STATES MAY
PRODUCE LIGHT RAIN IN FAR SRN PORTIONS OF THE AREA. WHILE ONLY HIGH
CLOUDS ARE EXPECTED OVERNIGHT...MOS BUFR SOUNDINGS HAVE CLOUD BASES
LOWERING SIGNIFICANTLY AT ALL TAF SITES EXCEPT SBY ON SATURDAY. MVFR
CIGS ARE FORECAST AT PHF ORF AND ECG. LIGHT RAIN BUT WITH NO VSBY
RESTRICTION ARE IN THE TAFS AT ORF AND ECG.

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...
HIGH PRESSURE REMAINS NW OF THE REGION TONIGHT...WITH LINGERING
LIGHT CAA ALONG THE COAST. THIS WILL MAINTAIN A 10-15KT NNW WIND
OVERNIGHT...WITH 2-3FT SEAS IN THE OCEAN AND 1-2FT WAVES IN THE BAY.
HIGH PRESSURE SPREADS ACROSS NEW ENGLAND SATURDAY AND SATURDAY
NIGHT...WITH THE SURFACE RIDGE AXIS REMAINING INLAND OVER THE
PIEDMONT. THIS WILL MAINTAIN LIGHT (5-10KT) NORTHERLY FLOW OVER THE
MARINE AREA. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY
NIGHT...AS LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY
NIGHT...AND THEN TRACKS NE OFF THE MID ATLANTIC COAST MONDAY AND
MONDAY NIGHT. THE SURFACE PRESSURE GRADIENT TIGHTENS AHEAD OF THE
LOW MONDAY...WHICH HAS THE POTENTIAL TO PRODUCE 15-20KT EASTERLY
FLOW OVER THE OCEAN AND LOWER BAY. THIS ONSHORE FLOW 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 LATER MONDAY
NIGHT INTO TUESDAY. A STRONG LOW PRESSURE SYSTEM TRACKS W OF THE
MOUNTAINS TUESDAY NIGHT...WITH A STRONG COLD FRONT CROSSING 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...LKB/MAS
LONG TERM...AJZ/MAS
AVIATION...LSA
MARINE...AJZ







000
FXUS61 KAKQ 200037
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
737 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST LATE TONIGHT THROUGH SATURDAY NIGHT. 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 COAST LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH SATURDAY/...
LATEST SFC ANALYSIS DEPICTS ~995 MB LO PRES OVER THE CANADIAN
MARITIMES WITH BROAD ~1028 MB HI PRES CENTERED OVER THE MIDWEST...RIDGING
ESE INTO THE MID ATLC STATES. WEAK LOW PRESSURE IS ALSO DEVELOPING
ACRS THE WRN GULF OF MEXICO...WITH PRECIP OVER LA/MS/AL AS OF 20Z
THIS AFTN. STILL MAINLY CLEAR SKIES OVER THE AKQ FORECAST AREA...BUT
SOME HIGH CIRRUS HAS STARTED TO OVERSPREAD THE REGION FROM THE SW
(AND BKN/OVC STRATO-CU HAS BEEN SLOW TO ERODE OVER THE ERN SHORE.
CURRENT TEMPS ARE GENLY IN THE 40S...AS CHILLY AS THE UPPER 30S AT
KWAL/KOXB IN THE CLOUDS...AND AS WARM AS AROUND 50 OVER NE NC AND
SOUTH CENTRAL VA.

FOR TONIGHT...DRY WX WILL PERSIST EVEN AS HIGH CLOUDS GRADUALLY
THICKEN/LOWER OVERNIGHT. EXPECT TEMPS TO RAPIDLY DROP AFTER SUNSET
UNDER MAINLY CLEAR SKIES...THEN BECOME NEARLY STEADY OVERNIGHT AS
CLOUDS SLOWLY INCREASE. LOWS MID 20S TO LOWER 30S.

SAT...SYSTEM FROM THE GULF CONTINUES TO REMAIN SHUNTED OFF TO OUR
SOUTH AS MID LEVEL FLOW REMAINS FAIRLY ZONAL. NAM/GFS STILL SHOW
SOME FORCING ALOFT MAKING WAY INTO PIEDMONT BETWEEN 12-18Z/SAT AND
BUFKIT SOUNDINGS SHOW SOME MODEST LIFT THROUGH THE DENDRITIC
GROWTH LAYER. PTYPE ACRS THE PIEDMONT WOULD TEND TO BE SNOW/SLEET
SAT AM ALTHOUGH SFC TEMPS SHOULD BE ABOVE 32 F (SFC WET BULBS IN
THE UPPER 20S INITIALLY). LOW LEVELS REMAIN QUITE DRY HOWEVER...SO ANY
PRECIP WILL BE VERY LIGHT (GENLY A FEW HUNDREDTHS IF THAT...WITH A
TRACE MORE LIKELY). THUS...WILL ONLY GO WITH 30% POPS AT MOST. BY
LATE MORNING/EARLY AFTN...AREA OF FORCING OVER THE PIEDMONT/CENTRAL
VA WEAKENS AS THE SFC LOW PUSHES OFF THE SE COAST. WILL CARRY LOW
CHC POPS IN FAR SE ZONES (ALL RAIN) THROUGH THE AFTN (ALTHOUGH
MOST OF THE PRECIP SHOULD STAY S OF THE CWA). CLOUDY TO MSTLY
CLOUDY W/ HIGHS GENLY 40-45 F SAT.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
SFC HIGH PRESSURE NOSES SOUTH INTO THE REGION SAT NIGHT/SUN...WITH DRY
CONDS THEN FOR SAT NGT AND SUN. LOWS IN THE 20S N TO THE 30S SE
SAT NIGHT...WITH HIGHS MAINLY FROM 45-50 F ON SUN. NEXT SYSTEM...THIS
ONE MORE AMPLIFIED WILL AFFECT THE AREA ON MON...WITH LIKELY POPS
ALL ZONES BY LATE MON AM/MON AFTN. LOOKS LIKE ALL RAIN ASIDE FROM
A BRIEF MIX POSSIBLE AT ONSET IN FAR NW COUNTIES. HIGHS MON ONLY
AROUND 40 F 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 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 /01Z SATURDAY THROUGH WEDNESDAY/...
STRATUS THAT WAS OVER THE LOWER EASTERN SHORE FRIDAY AFTN APPEAR TO
BE MOVING OFFSHORE. A SURFACE LOW NEAR THE GULF COAST AND AN UPPER
LEVEL DISTURBANCE THAT WILL MOVE ACROSS THE MID ATLANTIC STATES MAY
PRODUCE LIGHT RAIN IN FAR SRN PORTIONS OF THE AREA. WHILE ONLY HIGH
CLOUDS ARE EXPECTED OVERNIGHT...MOS BUFR SOUNDINGS HAVE CLOUD BASES
LOWERING SIGNIFICANTLY AT ALL TAF SITES EXCEPT SBY ON SATURDAY. MVFR
CIGS ARE FORECAST AT PHF ORF AND ECG. LIGHT RAIN BUT WITH NO VSBY
RESTRICTION ARE IN THE TAFS AT ORF AND ECG.

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...
HIGH PRESSURE REMAINS NW OF THE REGION TONIGHT...WITH LINGERING
LIGHT CAA ALONG THE COAST. THIS WILL MAINTAIN A 10-15KT NNW WIND
OVERNIGHT...WITH 2-3FT SEAS IN THE OCEAN AND 1-2FT WAVES IN THE BAY.
HIGH PRESSURE SPREADS ACROSS NEW ENGLAND SATURDAY AND SATURDAY
NIGHT...WITH THE SURFACE RIDGE AXIS REMAINING INLAND OVER THE
PIEDMONT. THIS WILL MAINTAIN LIGHT (5-10KT) NORTHERLY FLOW OVER THE
MARINE AREA. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY
NIGHT...AS LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY
NIGHT...AND THEN TRACKS NE OFF THE MID ATLANTIC COAST MONDAY AND
MONDAY NIGHT. THE SURFACE PRESSURE GRADIENT TIGHTENS AHEAD OF THE
LOW MONDAY...WHICH HAS THE POTENTIAL TO PRODUCE 15-20KT EASTERLY
FLOW OVER THE OCEAN AND LOWER BAY. THIS ONSHORE FLOW 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 LATER MONDAY
NIGHT INTO TUESDAY. A STRONG LOW PRESSURE SYSTEM TRACKS W OF THE
MOUNTAINS TUESDAY NIGHT...WITH A STRONG COLD FRONT CROSSING 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...LKB/MAS
LONG TERM...AJZ/MAS
AVIATION...LSA
MARINE...AJZ







000
FXUS61 KAKQ 200037
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
737 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST LATE TONIGHT THROUGH SATURDAY NIGHT. 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 COAST LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH SATURDAY/...
LATEST SFC ANALYSIS DEPICTS ~995 MB LO PRES OVER THE CANADIAN
MARITIMES WITH BROAD ~1028 MB HI PRES CENTERED OVER THE MIDWEST...RIDGING
ESE INTO THE MID ATLC STATES. WEAK LOW PRESSURE IS ALSO DEVELOPING
ACRS THE WRN GULF OF MEXICO...WITH PRECIP OVER LA/MS/AL AS OF 20Z
THIS AFTN. STILL MAINLY CLEAR SKIES OVER THE AKQ FORECAST AREA...BUT
SOME HIGH CIRRUS HAS STARTED TO OVERSPREAD THE REGION FROM THE SW
(AND BKN/OVC STRATO-CU HAS BEEN SLOW TO ERODE OVER THE ERN SHORE.
CURRENT TEMPS ARE GENLY IN THE 40S...AS CHILLY AS THE UPPER 30S AT
KWAL/KOXB IN THE CLOUDS...AND AS WARM AS AROUND 50 OVER NE NC AND
SOUTH CENTRAL VA.

FOR TONIGHT...DRY WX WILL PERSIST EVEN AS HIGH CLOUDS GRADUALLY
THICKEN/LOWER OVERNIGHT. EXPECT TEMPS TO RAPIDLY DROP AFTER SUNSET
UNDER MAINLY CLEAR SKIES...THEN BECOME NEARLY STEADY OVERNIGHT AS
CLOUDS SLOWLY INCREASE. LOWS MID 20S TO LOWER 30S.

SAT...SYSTEM FROM THE GULF CONTINUES TO REMAIN SHUNTED OFF TO OUR
SOUTH AS MID LEVEL FLOW REMAINS FAIRLY ZONAL. NAM/GFS STILL SHOW
SOME FORCING ALOFT MAKING WAY INTO PIEDMONT BETWEEN 12-18Z/SAT AND
BUFKIT SOUNDINGS SHOW SOME MODEST LIFT THROUGH THE DENDRITIC
GROWTH LAYER. PTYPE ACRS THE PIEDMONT WOULD TEND TO BE SNOW/SLEET
SAT AM ALTHOUGH SFC TEMPS SHOULD BE ABOVE 32 F (SFC WET BULBS IN
THE UPPER 20S INITIALLY). LOW LEVELS REMAIN QUITE DRY HOWEVER...SO ANY
PRECIP WILL BE VERY LIGHT (GENLY A FEW HUNDREDTHS IF THAT...WITH A
TRACE MORE LIKELY). THUS...WILL ONLY GO WITH 30% POPS AT MOST. BY
LATE MORNING/EARLY AFTN...AREA OF FORCING OVER THE PIEDMONT/CENTRAL
VA WEAKENS AS THE SFC LOW PUSHES OFF THE SE COAST. WILL CARRY LOW
CHC POPS IN FAR SE ZONES (ALL RAIN) THROUGH THE AFTN (ALTHOUGH
MOST OF THE PRECIP SHOULD STAY S OF THE CWA). CLOUDY TO MSTLY
CLOUDY W/ HIGHS GENLY 40-45 F SAT.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
SFC HIGH PRESSURE NOSES SOUTH INTO THE REGION SAT NIGHT/SUN...WITH DRY
CONDS THEN FOR SAT NGT AND SUN. LOWS IN THE 20S N TO THE 30S SE
SAT NIGHT...WITH HIGHS MAINLY FROM 45-50 F ON SUN. NEXT SYSTEM...THIS
ONE MORE AMPLIFIED WILL AFFECT THE AREA ON MON...WITH LIKELY POPS
ALL ZONES BY LATE MON AM/MON AFTN. LOOKS LIKE ALL RAIN ASIDE FROM
A BRIEF MIX POSSIBLE AT ONSET IN FAR NW COUNTIES. HIGHS MON ONLY
AROUND 40 F 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 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 /01Z SATURDAY THROUGH WEDNESDAY/...
STRATUS THAT WAS OVER THE LOWER EASTERN SHORE FRIDAY AFTN APPEAR TO
BE MOVING OFFSHORE. A SURFACE LOW NEAR THE GULF COAST AND AN UPPER
LEVEL DISTURBANCE THAT WILL MOVE ACROSS THE MID ATLANTIC STATES MAY
PRODUCE LIGHT RAIN IN FAR SRN PORTIONS OF THE AREA. WHILE ONLY HIGH
CLOUDS ARE EXPECTED OVERNIGHT...MOS BUFR SOUNDINGS HAVE CLOUD BASES
LOWERING SIGNIFICANTLY AT ALL TAF SITES EXCEPT SBY ON SATURDAY. MVFR
CIGS ARE FORECAST AT PHF ORF AND ECG. LIGHT RAIN BUT WITH NO VSBY
RESTRICTION ARE IN THE TAFS AT ORF AND ECG.

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...
HIGH PRESSURE REMAINS NW OF THE REGION TONIGHT...WITH LINGERING
LIGHT CAA ALONG THE COAST. THIS WILL MAINTAIN A 10-15KT NNW WIND
OVERNIGHT...WITH 2-3FT SEAS IN THE OCEAN AND 1-2FT WAVES IN THE BAY.
HIGH PRESSURE SPREADS ACROSS NEW ENGLAND SATURDAY AND SATURDAY
NIGHT...WITH THE SURFACE RIDGE AXIS REMAINING INLAND OVER THE
PIEDMONT. THIS WILL MAINTAIN LIGHT (5-10KT) NORTHERLY FLOW OVER THE
MARINE AREA. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY
NIGHT...AS LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY
NIGHT...AND THEN TRACKS NE OFF THE MID ATLANTIC COAST MONDAY AND
MONDAY NIGHT. THE SURFACE PRESSURE GRADIENT TIGHTENS AHEAD OF THE
LOW MONDAY...WHICH HAS THE POTENTIAL TO PRODUCE 15-20KT EASTERLY
FLOW OVER THE OCEAN AND LOWER BAY. THIS ONSHORE FLOW 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 LATER MONDAY
NIGHT INTO TUESDAY. A STRONG LOW PRESSURE SYSTEM TRACKS W OF THE
MOUNTAINS TUESDAY NIGHT...WITH A STRONG COLD FRONT CROSSING 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...LKB/MAS
LONG TERM...AJZ/MAS
AVIATION...LSA
MARINE...AJZ







000
FXUS61 KAKQ 200037
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
737 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST LATE TONIGHT THROUGH SATURDAY NIGHT. 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 COAST LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH SATURDAY/...
LATEST SFC ANALYSIS DEPICTS ~995 MB LO PRES OVER THE CANADIAN
MARITIMES WITH BROAD ~1028 MB HI PRES CENTERED OVER THE MIDWEST...RIDGING
ESE INTO THE MID ATLC STATES. WEAK LOW PRESSURE IS ALSO DEVELOPING
ACRS THE WRN GULF OF MEXICO...WITH PRECIP OVER LA/MS/AL AS OF 20Z
THIS AFTN. STILL MAINLY CLEAR SKIES OVER THE AKQ FORECAST AREA...BUT
SOME HIGH CIRRUS HAS STARTED TO OVERSPREAD THE REGION FROM THE SW
(AND BKN/OVC STRATO-CU HAS BEEN SLOW TO ERODE OVER THE ERN SHORE.
CURRENT TEMPS ARE GENLY IN THE 40S...AS CHILLY AS THE UPPER 30S AT
KWAL/KOXB IN THE CLOUDS...AND AS WARM AS AROUND 50 OVER NE NC AND
SOUTH CENTRAL VA.

FOR TONIGHT...DRY WX WILL PERSIST EVEN AS HIGH CLOUDS GRADUALLY
THICKEN/LOWER OVERNIGHT. EXPECT TEMPS TO RAPIDLY DROP AFTER SUNSET
UNDER MAINLY CLEAR SKIES...THEN BECOME NEARLY STEADY OVERNIGHT AS
CLOUDS SLOWLY INCREASE. LOWS MID 20S TO LOWER 30S.

SAT...SYSTEM FROM THE GULF CONTINUES TO REMAIN SHUNTED OFF TO OUR
SOUTH AS MID LEVEL FLOW REMAINS FAIRLY ZONAL. NAM/GFS STILL SHOW
SOME FORCING ALOFT MAKING WAY INTO PIEDMONT BETWEEN 12-18Z/SAT AND
BUFKIT SOUNDINGS SHOW SOME MODEST LIFT THROUGH THE DENDRITIC
GROWTH LAYER. PTYPE ACRS THE PIEDMONT WOULD TEND TO BE SNOW/SLEET
SAT AM ALTHOUGH SFC TEMPS SHOULD BE ABOVE 32 F (SFC WET BULBS IN
THE UPPER 20S INITIALLY). LOW LEVELS REMAIN QUITE DRY HOWEVER...SO ANY
PRECIP WILL BE VERY LIGHT (GENLY A FEW HUNDREDTHS IF THAT...WITH A
TRACE MORE LIKELY). THUS...WILL ONLY GO WITH 30% POPS AT MOST. BY
LATE MORNING/EARLY AFTN...AREA OF FORCING OVER THE PIEDMONT/CENTRAL
VA WEAKENS AS THE SFC LOW PUSHES OFF THE SE COAST. WILL CARRY LOW
CHC POPS IN FAR SE ZONES (ALL RAIN) THROUGH THE AFTN (ALTHOUGH
MOST OF THE PRECIP SHOULD STAY S OF THE CWA). CLOUDY TO MSTLY
CLOUDY W/ HIGHS GENLY 40-45 F SAT.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
SFC HIGH PRESSURE NOSES SOUTH INTO THE REGION SAT NIGHT/SUN...WITH DRY
CONDS THEN FOR SAT NGT AND SUN. LOWS IN THE 20S N TO THE 30S SE
SAT NIGHT...WITH HIGHS MAINLY FROM 45-50 F ON SUN. NEXT SYSTEM...THIS
ONE MORE AMPLIFIED WILL AFFECT THE AREA ON MON...WITH LIKELY POPS
ALL ZONES BY LATE MON AM/MON AFTN. LOOKS LIKE ALL RAIN ASIDE FROM
A BRIEF MIX POSSIBLE AT ONSET IN FAR NW COUNTIES. HIGHS MON ONLY
AROUND 40 F 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 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 /01Z SATURDAY THROUGH WEDNESDAY/...
STRATUS THAT WAS OVER THE LOWER EASTERN SHORE FRIDAY AFTN APPEAR TO
BE MOVING OFFSHORE. A SURFACE LOW NEAR THE GULF COAST AND AN UPPER
LEVEL DISTURBANCE THAT WILL MOVE ACROSS THE MID ATLANTIC STATES MAY
PRODUCE LIGHT RAIN IN FAR SRN PORTIONS OF THE AREA. WHILE ONLY HIGH
CLOUDS ARE EXPECTED OVERNIGHT...MOS BUFR SOUNDINGS HAVE CLOUD BASES
LOWERING SIGNIFICANTLY AT ALL TAF SITES EXCEPT SBY ON SATURDAY. MVFR
CIGS ARE FORECAST AT PHF ORF AND ECG. LIGHT RAIN BUT WITH NO VSBY
RESTRICTION ARE IN THE TAFS AT ORF AND ECG.

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...
HIGH PRESSURE REMAINS NW OF THE REGION TONIGHT...WITH LINGERING
LIGHT CAA ALONG THE COAST. THIS WILL MAINTAIN A 10-15KT NNW WIND
OVERNIGHT...WITH 2-3FT SEAS IN THE OCEAN AND 1-2FT WAVES IN THE BAY.
HIGH PRESSURE SPREADS ACROSS NEW ENGLAND SATURDAY AND SATURDAY
NIGHT...WITH THE SURFACE RIDGE AXIS REMAINING INLAND OVER THE
PIEDMONT. THIS WILL MAINTAIN LIGHT (5-10KT) NORTHERLY FLOW OVER THE
MARINE AREA. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY
NIGHT...AS LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY
NIGHT...AND THEN TRACKS NE OFF THE MID ATLANTIC COAST MONDAY AND
MONDAY NIGHT. THE SURFACE PRESSURE GRADIENT TIGHTENS AHEAD OF THE
LOW MONDAY...WHICH HAS THE POTENTIAL TO PRODUCE 15-20KT EASTERLY
FLOW OVER THE OCEAN AND LOWER BAY. THIS ONSHORE FLOW 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 LATER MONDAY
NIGHT INTO TUESDAY. A STRONG LOW PRESSURE SYSTEM TRACKS W OF THE
MOUNTAINS TUESDAY NIGHT...WITH A STRONG COLD FRONT CROSSING 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...LKB/MAS
LONG TERM...AJZ/MAS
AVIATION...LSA
MARINE...AJZ







000
FXUS61 KPHI 192328
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
628 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE JUST NORTH OF LAKE SUPERIOR WILL GRADUALLY MOVE
EASTWARD INTO NORTHERN NEW ENGLAND THRU MONDAY. A WAVE OF LOW
PRESSURE WILL FORM ALONG THE MID-ATLANTIC COASTLINE ON MONDAY
AND MOVE NORTHEASTWARD JUST OFFSHORE ON TUESDAY. MEANWHILE...
A STRONG AREA OF LOW-PRESSURE WILL FORM OVER THE MISSISSIPPI
VALLEY AND MOVE THRU THE GREAT LAKES REGION DURING THE MIDDLE
OF THE WEEK...BRINGING A STRONG COLD FRONT THRU THE REGION
BY THURSDAY. HIGH PRESSURE IS PROJECTED TO BUILD IN ON FRIDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
WITH THIS ESTF UPDATE WE ADJUSTED SKY COVER GOING MORE PESSIMISTIC
NORTH BASED ON CURRENT POSNING OF CLOUDS AND THE 18Z MODELS
BRINGING AN 850MB SHORT WAVE THRU THE NORTHERN PART OF OUR CWA. WE
UPPED TEMPS SLIGHTLY NORTH, LEFT THE REST AS IS. WITH LIGHT WINDS,
CONFIDENCE ABOUT TEMPS DUE TO CLOUD COVER UNCERTAINTY IS LOWER
THAN AVERAGE.

FOR TONIGHT...NW WINDS WILL CONTINUE BUT WILL BECOME LIGHTER AS
CANADIAN LOW PRES MOVES AWAY AND HIGH PRES MOVES CLOSED WITH
RESULTING RELAXED PRES GRAD.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH 6 PM SATURDAY/...
FOR SATURDAY...HIGH PRES CENTERED OVER CANADA SHIFTS EWD FROM
ONTARIO INTO QUEBEC. A RIDGE AXIS IS FCST TO EXTEND SWD THROUGH THE
MID-ATLANTIC REGION RESULTING IN ONLY LIGHT NLY WINDS. SOME LOW-LVL
MOISTURE SHOULD REMAIN TRAPPED BELOW THE LARGE-SCALE SUBSIDENCE
INVERSION BUT HARD TO SAY HOW EXTENSIVE ANY LOW CLOUDS MAY BE. THE
12-KM NAM SHOWS A THIN LOW CLOUD LAYER DEVELOPING DURG THE DAY BUT
HIGHER-RES ARW/NMM AND THE GFS DO NOT. THERE WILL BE SOME HIGHER
CLOUDS ALSO ASSOCD WITH THE SHRTWV NOW MOVING ENEWD OUT OF THE SRN
PLAINS...HWVR POPS REMAIN NEAR ZERO.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* SLIGHT CHANCE OF SNOW SHOWERS SUNDAY MORNING MAINLY NORTH.
* SNOW POSSIBLE NORTHWEST OF THE I-95 CORRIDOR LATE MONDAY
  THRU EARLY TUESDAY.
* POTENTIAL FOR HEAVY RAIN INCREASING ON CHRISTMAS EVE DAY.

OVERVIEW...

MID-LEVEL BLOCKING PATTERN OVER NOAM BEGINS TO DISLODGE IN RESPONSE
JET ENERGY MOVING INTO THE PACIFIC NORTHWEST THIS WEEKEND...CARVING
OUT A DEEP TROUGH OVER THE MS VALLEY EARLY EARLY NEXT WEEK...WHICH
LEADS TO INCLEMENT WEATHER IN THE TUESDAY THRU WEDNESDAY TIME FRAME.

DETAILS...

SUNDAY...
SHORTWAVE LIFTING THROUGH THE REGION EARLY IN THE DAY MAY GENERATE
ENOUGH LIFT ALONG WITH MARGINAL MOISTURE IN THE COLUMN TO PRODUCE
SOME LIGHT SNOW SHOWERS...MAINLY DURING THE PRE-DAWN HOURS. LITTLE
IF ANY ACCUMULATION EXPECTED AS MOISTURE IS VERY LIMITED. RIDGING
THEN BUILDS IN SO FAIR WEATHER IS EXPECTED THE REMAINDER OF THE DAY.

MONDAY AND TUESDAY...
HIGH PRESSURE ANCHORS ALONG THE LEE OF THE APPALACHIANS. A SOUTHERN
STREAM SHORTWAVE WILL INDUCE LOW-PRESSURE OF THE MID-ATLANTIC COAST.
MODELS BRING QPF NORTHWARD INTO THE AREA ON MONDAY NIGHT INTO EARLY
TUESDAY. THERMAL PROFILES ARE COLD ENOUGH FOR SNOW TO THE NORTHWEST
OF THE I-95 CORRIDOR...BUT THE BEST LIFT IS FOCUSED JUST SOUTHEAST
OF THIS AREA...AND THE SYSTEM COULD TRACK FURTHER TO THE SOUTH PER
12Z UKMET MODEL. STILL A LOT OF UNCERTAINTY WITH ULTIMATE TRACK.

WEDNESDAY...
A MID-LEVEL RIDGE WILL MOVE THROUGH THE REGION TUESDAY NIGHT INTO
EARLY WEDNESDAY LEADING TO A BRIEF RESPITE BETWEEN WEATHER SYSTEMS.
THEN A MID-LEVEL TROUGH IS PROJECTED TO BECOME NEGATIVELY TILTED
OVER THE OHIO VALLEY ON WED...LEADING TO A MERIDIONAL FLOW ALONG
THE EAST COAST...WITH THE ENTIRE COLUMN EXPECTED TO BE WELL ABOVE
FREEZING ACROSS THE CWA FAVORING A RAIN EVENT. THERE ARE SEVERAL
INGREDIENTS COMING TOGETHER FOR HEAVY RAIN. IN PARTICULAR...DEEP
GULF MOISTURE...LOW-LEVEL ISENTROPIC LIFT...MID-LEVEL PVA...AND
THE RIGHT-REAR QUADRANT OF A 140 KNOT UPPER-LEVEL JET JUST NORTH.
THE SYSTEM SHOULD BE FAIRLY PROGRESSIVE BUT WILL HAVE TO MONITOR
POTENTIAL FOR FLOODING.

THU AND FRI...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS
TO BUILD IN. TEMPERATURES WILL RETURN TO SEASONABLE LEVELS AND
THERE COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW.

&&

.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THE 00Z TAFS TAKE CIGS DOWN TO MVFR LEVELS TONIGHT FROM THE KPHL
AREA AIRPORTS NORTHWESTWARD WITH IMPROVEMENT ON SATURDAY. ITS BEEN
TOUGH TO SHAKE THIS STRATOCU LEVEL CLOUDINESS PATTERN.

FOR TONIGHT. LOW CLOUDS ADVANCING IN FROM THE HIGHER TERRAIN
AIRPORTS ARE STILL HEADING INTO THE TERMINALS. WE BRING MVFR CIG
POTENTIAL FROM THE GET GO AT KABE AND KRDG (HIER CONFIDENCE
OVERNIGHT) AND BRING IT DOWN TO THE KPHL METRO AIRPORTS AFTER 05Z.
WE LEAVE KACY AND KMIV VFR. WINDS WILL BE LIGHT FROM THE
NORTHWEST. NO VSBY RESTRICTIONS EXPECTED.

ON SATURDAY, PREDICTING THE MVFR CIG TO BECOME SCATTERED DURING
THE MORNING FROM THE KPHL METRO AIRPORTS NWWD WITH A CIRRUS CIG
ABOVE. KACY AND KMIV NOT EXPECTING A MVFR CIG. IT WILL BE A WEAK
PRESSURE PATTERN AND WINDS WILL BE LIGHT. A NORTHERLY DIRECTION
IS FAVORED, BUT SPEEDS ARE EXPECTED TO REMAIN BELOW 10 KNOTS,
PROBABLY PREDOMINATELY LESS THAN 6 KNOTS AT SOME OF THE MORE
RURAL AIRPORTS AND TERMINALS.

OUTLOOK...
SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED.
MONDAY AND TUESDAY...IFR POSSIBLE IN SHRA AND SHSN.
WEDNESDAY...IFR POSSIBLE IN RAIN AND FOG.

&&

.MARINE...
SUB-SCA CONDS ARE EXPECTED FOR THE NEXT 24 HOURS AT LEAST. SMWHT
GUST NW WINDS THIS EVENING WILL GRADUALLY DIMINISH TONIGHT THROUGH
SATURDAY AS A RIDGE OF HIGH PRES MOVES OVERHEAD. SEAS ARE
CURRENTLY RUNNING 2 TO 3 FT BUT THEY SHOULD GRADUALLY DIMINISH
ALSO.

OUTLOOK...
SUNDAY AND MONDAY...SUB-SCA CONDITIONS EXPECTED.
TUESDAY...SCA MAY BE NEEDED FOR BUILDING SEAS.
WEDNESDAY...GALE WARNING MAY BE NEEDED.

&&

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

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...AMC/GIGI
SHORT TERM...AMC
LONG TERM...FRANCK
AVIATION...FRANCK/GIGI
MARINE...AMC/FRANCK







000
FXUS61 KPHI 192328
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
628 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE JUST NORTH OF LAKE SUPERIOR WILL GRADUALLY MOVE
EASTWARD INTO NORTHERN NEW ENGLAND THRU MONDAY. A WAVE OF LOW
PRESSURE WILL FORM ALONG THE MID-ATLANTIC COASTLINE ON MONDAY
AND MOVE NORTHEASTWARD JUST OFFSHORE ON TUESDAY. MEANWHILE...
A STRONG AREA OF LOW-PRESSURE WILL FORM OVER THE MISSISSIPPI
VALLEY AND MOVE THRU THE GREAT LAKES REGION DURING THE MIDDLE
OF THE WEEK...BRINGING A STRONG COLD FRONT THRU THE REGION
BY THURSDAY. HIGH PRESSURE IS PROJECTED TO BUILD IN ON FRIDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
WITH THIS ESTF UPDATE WE ADJUSTED SKY COVER GOING MORE PESSIMISTIC
NORTH BASED ON CURRENT POSNING OF CLOUDS AND THE 18Z MODELS
BRINGING AN 850MB SHORT WAVE THRU THE NORTHERN PART OF OUR CWA. WE
UPPED TEMPS SLIGHTLY NORTH, LEFT THE REST AS IS. WITH LIGHT WINDS,
CONFIDENCE ABOUT TEMPS DUE TO CLOUD COVER UNCERTAINTY IS LOWER
THAN AVERAGE.

FOR TONIGHT...NW WINDS WILL CONTINUE BUT WILL BECOME LIGHTER AS
CANADIAN LOW PRES MOVES AWAY AND HIGH PRES MOVES CLOSED WITH
RESULTING RELAXED PRES GRAD.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH 6 PM SATURDAY/...
FOR SATURDAY...HIGH PRES CENTERED OVER CANADA SHIFTS EWD FROM
ONTARIO INTO QUEBEC. A RIDGE AXIS IS FCST TO EXTEND SWD THROUGH THE
MID-ATLANTIC REGION RESULTING IN ONLY LIGHT NLY WINDS. SOME LOW-LVL
MOISTURE SHOULD REMAIN TRAPPED BELOW THE LARGE-SCALE SUBSIDENCE
INVERSION BUT HARD TO SAY HOW EXTENSIVE ANY LOW CLOUDS MAY BE. THE
12-KM NAM SHOWS A THIN LOW CLOUD LAYER DEVELOPING DURG THE DAY BUT
HIGHER-RES ARW/NMM AND THE GFS DO NOT. THERE WILL BE SOME HIGHER
CLOUDS ALSO ASSOCD WITH THE SHRTWV NOW MOVING ENEWD OUT OF THE SRN
PLAINS...HWVR POPS REMAIN NEAR ZERO.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* SLIGHT CHANCE OF SNOW SHOWERS SUNDAY MORNING MAINLY NORTH.
* SNOW POSSIBLE NORTHWEST OF THE I-95 CORRIDOR LATE MONDAY
  THRU EARLY TUESDAY.
* POTENTIAL FOR HEAVY RAIN INCREASING ON CHRISTMAS EVE DAY.

OVERVIEW...

MID-LEVEL BLOCKING PATTERN OVER NOAM BEGINS TO DISLODGE IN RESPONSE
JET ENERGY MOVING INTO THE PACIFIC NORTHWEST THIS WEEKEND...CARVING
OUT A DEEP TROUGH OVER THE MS VALLEY EARLY EARLY NEXT WEEK...WHICH
LEADS TO INCLEMENT WEATHER IN THE TUESDAY THRU WEDNESDAY TIME FRAME.

DETAILS...

SUNDAY...
SHORTWAVE LIFTING THROUGH THE REGION EARLY IN THE DAY MAY GENERATE
ENOUGH LIFT ALONG WITH MARGINAL MOISTURE IN THE COLUMN TO PRODUCE
SOME LIGHT SNOW SHOWERS...MAINLY DURING THE PRE-DAWN HOURS. LITTLE
IF ANY ACCUMULATION EXPECTED AS MOISTURE IS VERY LIMITED. RIDGING
THEN BUILDS IN SO FAIR WEATHER IS EXPECTED THE REMAINDER OF THE DAY.

MONDAY AND TUESDAY...
HIGH PRESSURE ANCHORS ALONG THE LEE OF THE APPALACHIANS. A SOUTHERN
STREAM SHORTWAVE WILL INDUCE LOW-PRESSURE OF THE MID-ATLANTIC COAST.
MODELS BRING QPF NORTHWARD INTO THE AREA ON MONDAY NIGHT INTO EARLY
TUESDAY. THERMAL PROFILES ARE COLD ENOUGH FOR SNOW TO THE NORTHWEST
OF THE I-95 CORRIDOR...BUT THE BEST LIFT IS FOCUSED JUST SOUTHEAST
OF THIS AREA...AND THE SYSTEM COULD TRACK FURTHER TO THE SOUTH PER
12Z UKMET MODEL. STILL A LOT OF UNCERTAINTY WITH ULTIMATE TRACK.

WEDNESDAY...
A MID-LEVEL RIDGE WILL MOVE THROUGH THE REGION TUESDAY NIGHT INTO
EARLY WEDNESDAY LEADING TO A BRIEF RESPITE BETWEEN WEATHER SYSTEMS.
THEN A MID-LEVEL TROUGH IS PROJECTED TO BECOME NEGATIVELY TILTED
OVER THE OHIO VALLEY ON WED...LEADING TO A MERIDIONAL FLOW ALONG
THE EAST COAST...WITH THE ENTIRE COLUMN EXPECTED TO BE WELL ABOVE
FREEZING ACROSS THE CWA FAVORING A RAIN EVENT. THERE ARE SEVERAL
INGREDIENTS COMING TOGETHER FOR HEAVY RAIN. IN PARTICULAR...DEEP
GULF MOISTURE...LOW-LEVEL ISENTROPIC LIFT...MID-LEVEL PVA...AND
THE RIGHT-REAR QUADRANT OF A 140 KNOT UPPER-LEVEL JET JUST NORTH.
THE SYSTEM SHOULD BE FAIRLY PROGRESSIVE BUT WILL HAVE TO MONITOR
POTENTIAL FOR FLOODING.

THU AND FRI...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS
TO BUILD IN. TEMPERATURES WILL RETURN TO SEASONABLE LEVELS AND
THERE COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW.

&&

.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THE 00Z TAFS TAKE CIGS DOWN TO MVFR LEVELS TONIGHT FROM THE KPHL
AREA AIRPORTS NORTHWESTWARD WITH IMPROVEMENT ON SATURDAY. ITS BEEN
TOUGH TO SHAKE THIS STRATOCU LEVEL CLOUDINESS PATTERN.

FOR TONIGHT. LOW CLOUDS ADVANCING IN FROM THE HIGHER TERRAIN
AIRPORTS ARE STILL HEADING INTO THE TERMINALS. WE BRING MVFR CIG
POTENTIAL FROM THE GET GO AT KABE AND KRDG (HIER CONFIDENCE
OVERNIGHT) AND BRING IT DOWN TO THE KPHL METRO AIRPORTS AFTER 05Z.
WE LEAVE KACY AND KMIV VFR. WINDS WILL BE LIGHT FROM THE
NORTHWEST. NO VSBY RESTRICTIONS EXPECTED.

ON SATURDAY, PREDICTING THE MVFR CIG TO BECOME SCATTERED DURING
THE MORNING FROM THE KPHL METRO AIRPORTS NWWD WITH A CIRRUS CIG
ABOVE. KACY AND KMIV NOT EXPECTING A MVFR CIG. IT WILL BE A WEAK
PRESSURE PATTERN AND WINDS WILL BE LIGHT. A NORTHERLY DIRECTION
IS FAVORED, BUT SPEEDS ARE EXPECTED TO REMAIN BELOW 10 KNOTS,
PROBABLY PREDOMINATELY LESS THAN 6 KNOTS AT SOME OF THE MORE
RURAL AIRPORTS AND TERMINALS.

OUTLOOK...
SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED.
MONDAY AND TUESDAY...IFR POSSIBLE IN SHRA AND SHSN.
WEDNESDAY...IFR POSSIBLE IN RAIN AND FOG.

&&

.MARINE...
SUB-SCA CONDS ARE EXPECTED FOR THE NEXT 24 HOURS AT LEAST. SMWHT
GUST NW WINDS THIS EVENING WILL GRADUALLY DIMINISH TONIGHT THROUGH
SATURDAY AS A RIDGE OF HIGH PRES MOVES OVERHEAD. SEAS ARE
CURRENTLY RUNNING 2 TO 3 FT BUT THEY SHOULD GRADUALLY DIMINISH
ALSO.

OUTLOOK...
SUNDAY AND MONDAY...SUB-SCA CONDITIONS EXPECTED.
TUESDAY...SCA MAY BE NEEDED FOR BUILDING SEAS.
WEDNESDAY...GALE WARNING MAY BE NEEDED.

&&

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

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...AMC/GIGI
SHORT TERM...AMC
LONG TERM...FRANCK
AVIATION...FRANCK/GIGI
MARINE...AMC/FRANCK







000
FXUS61 KPHI 192328
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
628 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE JUST NORTH OF LAKE SUPERIOR WILL GRADUALLY MOVE
EASTWARD INTO NORTHERN NEW ENGLAND THRU MONDAY. A WAVE OF LOW
PRESSURE WILL FORM ALONG THE MID-ATLANTIC COASTLINE ON MONDAY
AND MOVE NORTHEASTWARD JUST OFFSHORE ON TUESDAY. MEANWHILE...
A STRONG AREA OF LOW-PRESSURE WILL FORM OVER THE MISSISSIPPI
VALLEY AND MOVE THRU THE GREAT LAKES REGION DURING THE MIDDLE
OF THE WEEK...BRINGING A STRONG COLD FRONT THRU THE REGION
BY THURSDAY. HIGH PRESSURE IS PROJECTED TO BUILD IN ON FRIDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
WITH THIS ESTF UPDATE WE ADJUSTED SKY COVER GOING MORE PESSIMISTIC
NORTH BASED ON CURRENT POSNING OF CLOUDS AND THE 18Z MODELS
BRINGING AN 850MB SHORT WAVE THRU THE NORTHERN PART OF OUR CWA. WE
UPPED TEMPS SLIGHTLY NORTH, LEFT THE REST AS IS. WITH LIGHT WINDS,
CONFIDENCE ABOUT TEMPS DUE TO CLOUD COVER UNCERTAINTY IS LOWER
THAN AVERAGE.

FOR TONIGHT...NW WINDS WILL CONTINUE BUT WILL BECOME LIGHTER AS
CANADIAN LOW PRES MOVES AWAY AND HIGH PRES MOVES CLOSED WITH
RESULTING RELAXED PRES GRAD.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH 6 PM SATURDAY/...
FOR SATURDAY...HIGH PRES CENTERED OVER CANADA SHIFTS EWD FROM
ONTARIO INTO QUEBEC. A RIDGE AXIS IS FCST TO EXTEND SWD THROUGH THE
MID-ATLANTIC REGION RESULTING IN ONLY LIGHT NLY WINDS. SOME LOW-LVL
MOISTURE SHOULD REMAIN TRAPPED BELOW THE LARGE-SCALE SUBSIDENCE
INVERSION BUT HARD TO SAY HOW EXTENSIVE ANY LOW CLOUDS MAY BE. THE
12-KM NAM SHOWS A THIN LOW CLOUD LAYER DEVELOPING DURG THE DAY BUT
HIGHER-RES ARW/NMM AND THE GFS DO NOT. THERE WILL BE SOME HIGHER
CLOUDS ALSO ASSOCD WITH THE SHRTWV NOW MOVING ENEWD OUT OF THE SRN
PLAINS...HWVR POPS REMAIN NEAR ZERO.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* SLIGHT CHANCE OF SNOW SHOWERS SUNDAY MORNING MAINLY NORTH.
* SNOW POSSIBLE NORTHWEST OF THE I-95 CORRIDOR LATE MONDAY
  THRU EARLY TUESDAY.
* POTENTIAL FOR HEAVY RAIN INCREASING ON CHRISTMAS EVE DAY.

OVERVIEW...

MID-LEVEL BLOCKING PATTERN OVER NOAM BEGINS TO DISLODGE IN RESPONSE
JET ENERGY MOVING INTO THE PACIFIC NORTHWEST THIS WEEKEND...CARVING
OUT A DEEP TROUGH OVER THE MS VALLEY EARLY EARLY NEXT WEEK...WHICH
LEADS TO INCLEMENT WEATHER IN THE TUESDAY THRU WEDNESDAY TIME FRAME.

DETAILS...

SUNDAY...
SHORTWAVE LIFTING THROUGH THE REGION EARLY IN THE DAY MAY GENERATE
ENOUGH LIFT ALONG WITH MARGINAL MOISTURE IN THE COLUMN TO PRODUCE
SOME LIGHT SNOW SHOWERS...MAINLY DURING THE PRE-DAWN HOURS. LITTLE
IF ANY ACCUMULATION EXPECTED AS MOISTURE IS VERY LIMITED. RIDGING
THEN BUILDS IN SO FAIR WEATHER IS EXPECTED THE REMAINDER OF THE DAY.

MONDAY AND TUESDAY...
HIGH PRESSURE ANCHORS ALONG THE LEE OF THE APPALACHIANS. A SOUTHERN
STREAM SHORTWAVE WILL INDUCE LOW-PRESSURE OF THE MID-ATLANTIC COAST.
MODELS BRING QPF NORTHWARD INTO THE AREA ON MONDAY NIGHT INTO EARLY
TUESDAY. THERMAL PROFILES ARE COLD ENOUGH FOR SNOW TO THE NORTHWEST
OF THE I-95 CORRIDOR...BUT THE BEST LIFT IS FOCUSED JUST SOUTHEAST
OF THIS AREA...AND THE SYSTEM COULD TRACK FURTHER TO THE SOUTH PER
12Z UKMET MODEL. STILL A LOT OF UNCERTAINTY WITH ULTIMATE TRACK.

WEDNESDAY...
A MID-LEVEL RIDGE WILL MOVE THROUGH THE REGION TUESDAY NIGHT INTO
EARLY WEDNESDAY LEADING TO A BRIEF RESPITE BETWEEN WEATHER SYSTEMS.
THEN A MID-LEVEL TROUGH IS PROJECTED TO BECOME NEGATIVELY TILTED
OVER THE OHIO VALLEY ON WED...LEADING TO A MERIDIONAL FLOW ALONG
THE EAST COAST...WITH THE ENTIRE COLUMN EXPECTED TO BE WELL ABOVE
FREEZING ACROSS THE CWA FAVORING A RAIN EVENT. THERE ARE SEVERAL
INGREDIENTS COMING TOGETHER FOR HEAVY RAIN. IN PARTICULAR...DEEP
GULF MOISTURE...LOW-LEVEL ISENTROPIC LIFT...MID-LEVEL PVA...AND
THE RIGHT-REAR QUADRANT OF A 140 KNOT UPPER-LEVEL JET JUST NORTH.
THE SYSTEM SHOULD BE FAIRLY PROGRESSIVE BUT WILL HAVE TO MONITOR
POTENTIAL FOR FLOODING.

THU AND FRI...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS
TO BUILD IN. TEMPERATURES WILL RETURN TO SEASONABLE LEVELS AND
THERE COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW.

&&

.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THE 00Z TAFS TAKE CIGS DOWN TO MVFR LEVELS TONIGHT FROM THE KPHL
AREA AIRPORTS NORTHWESTWARD WITH IMPROVEMENT ON SATURDAY. ITS BEEN
TOUGH TO SHAKE THIS STRATOCU LEVEL CLOUDINESS PATTERN.

FOR TONIGHT. LOW CLOUDS ADVANCING IN FROM THE HIGHER TERRAIN
AIRPORTS ARE STILL HEADING INTO THE TERMINALS. WE BRING MVFR CIG
POTENTIAL FROM THE GET GO AT KABE AND KRDG (HIER CONFIDENCE
OVERNIGHT) AND BRING IT DOWN TO THE KPHL METRO AIRPORTS AFTER 05Z.
WE LEAVE KACY AND KMIV VFR. WINDS WILL BE LIGHT FROM THE
NORTHWEST. NO VSBY RESTRICTIONS EXPECTED.

ON SATURDAY, PREDICTING THE MVFR CIG TO BECOME SCATTERED DURING
THE MORNING FROM THE KPHL METRO AIRPORTS NWWD WITH A CIRRUS CIG
ABOVE. KACY AND KMIV NOT EXPECTING A MVFR CIG. IT WILL BE A WEAK
PRESSURE PATTERN AND WINDS WILL BE LIGHT. A NORTHERLY DIRECTION
IS FAVORED, BUT SPEEDS ARE EXPECTED TO REMAIN BELOW 10 KNOTS,
PROBABLY PREDOMINATELY LESS THAN 6 KNOTS AT SOME OF THE MORE
RURAL AIRPORTS AND TERMINALS.

OUTLOOK...
SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED.
MONDAY AND TUESDAY...IFR POSSIBLE IN SHRA AND SHSN.
WEDNESDAY...IFR POSSIBLE IN RAIN AND FOG.

&&

.MARINE...
SUB-SCA CONDS ARE EXPECTED FOR THE NEXT 24 HOURS AT LEAST. SMWHT
GUST NW WINDS THIS EVENING WILL GRADUALLY DIMINISH TONIGHT THROUGH
SATURDAY AS A RIDGE OF HIGH PRES MOVES OVERHEAD. SEAS ARE
CURRENTLY RUNNING 2 TO 3 FT BUT THEY SHOULD GRADUALLY DIMINISH
ALSO.

OUTLOOK...
SUNDAY AND MONDAY...SUB-SCA CONDITIONS EXPECTED.
TUESDAY...SCA MAY BE NEEDED FOR BUILDING SEAS.
WEDNESDAY...GALE WARNING MAY BE NEEDED.

&&

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

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...AMC/GIGI
SHORT TERM...AMC
LONG TERM...FRANCK
AVIATION...FRANCK/GIGI
MARINE...AMC/FRANCK







000
FXUS61 KPHI 192328
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
628 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE JUST NORTH OF LAKE SUPERIOR WILL GRADUALLY MOVE
EASTWARD INTO NORTHERN NEW ENGLAND THRU MONDAY. A WAVE OF LOW
PRESSURE WILL FORM ALONG THE MID-ATLANTIC COASTLINE ON MONDAY
AND MOVE NORTHEASTWARD JUST OFFSHORE ON TUESDAY. MEANWHILE...
A STRONG AREA OF LOW-PRESSURE WILL FORM OVER THE MISSISSIPPI
VALLEY AND MOVE THRU THE GREAT LAKES REGION DURING THE MIDDLE
OF THE WEEK...BRINGING A STRONG COLD FRONT THRU THE REGION
BY THURSDAY. HIGH PRESSURE IS PROJECTED TO BUILD IN ON FRIDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
WITH THIS ESTF UPDATE WE ADJUSTED SKY COVER GOING MORE PESSIMISTIC
NORTH BASED ON CURRENT POSNING OF CLOUDS AND THE 18Z MODELS
BRINGING AN 850MB SHORT WAVE THRU THE NORTHERN PART OF OUR CWA. WE
UPPED TEMPS SLIGHTLY NORTH, LEFT THE REST AS IS. WITH LIGHT WINDS,
CONFIDENCE ABOUT TEMPS DUE TO CLOUD COVER UNCERTAINTY IS LOWER
THAN AVERAGE.

FOR TONIGHT...NW WINDS WILL CONTINUE BUT WILL BECOME LIGHTER AS
CANADIAN LOW PRES MOVES AWAY AND HIGH PRES MOVES CLOSED WITH
RESULTING RELAXED PRES GRAD.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH 6 PM SATURDAY/...
FOR SATURDAY...HIGH PRES CENTERED OVER CANADA SHIFTS EWD FROM
ONTARIO INTO QUEBEC. A RIDGE AXIS IS FCST TO EXTEND SWD THROUGH THE
MID-ATLANTIC REGION RESULTING IN ONLY LIGHT NLY WINDS. SOME LOW-LVL
MOISTURE SHOULD REMAIN TRAPPED BELOW THE LARGE-SCALE SUBSIDENCE
INVERSION BUT HARD TO SAY HOW EXTENSIVE ANY LOW CLOUDS MAY BE. THE
12-KM NAM SHOWS A THIN LOW CLOUD LAYER DEVELOPING DURG THE DAY BUT
HIGHER-RES ARW/NMM AND THE GFS DO NOT. THERE WILL BE SOME HIGHER
CLOUDS ALSO ASSOCD WITH THE SHRTWV NOW MOVING ENEWD OUT OF THE SRN
PLAINS...HWVR POPS REMAIN NEAR ZERO.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* SLIGHT CHANCE OF SNOW SHOWERS SUNDAY MORNING MAINLY NORTH.
* SNOW POSSIBLE NORTHWEST OF THE I-95 CORRIDOR LATE MONDAY
  THRU EARLY TUESDAY.
* POTENTIAL FOR HEAVY RAIN INCREASING ON CHRISTMAS EVE DAY.

OVERVIEW...

MID-LEVEL BLOCKING PATTERN OVER NOAM BEGINS TO DISLODGE IN RESPONSE
JET ENERGY MOVING INTO THE PACIFIC NORTHWEST THIS WEEKEND...CARVING
OUT A DEEP TROUGH OVER THE MS VALLEY EARLY EARLY NEXT WEEK...WHICH
LEADS TO INCLEMENT WEATHER IN THE TUESDAY THRU WEDNESDAY TIME FRAME.

DETAILS...

SUNDAY...
SHORTWAVE LIFTING THROUGH THE REGION EARLY IN THE DAY MAY GENERATE
ENOUGH LIFT ALONG WITH MARGINAL MOISTURE IN THE COLUMN TO PRODUCE
SOME LIGHT SNOW SHOWERS...MAINLY DURING THE PRE-DAWN HOURS. LITTLE
IF ANY ACCUMULATION EXPECTED AS MOISTURE IS VERY LIMITED. RIDGING
THEN BUILDS IN SO FAIR WEATHER IS EXPECTED THE REMAINDER OF THE DAY.

MONDAY AND TUESDAY...
HIGH PRESSURE ANCHORS ALONG THE LEE OF THE APPALACHIANS. A SOUTHERN
STREAM SHORTWAVE WILL INDUCE LOW-PRESSURE OF THE MID-ATLANTIC COAST.
MODELS BRING QPF NORTHWARD INTO THE AREA ON MONDAY NIGHT INTO EARLY
TUESDAY. THERMAL PROFILES ARE COLD ENOUGH FOR SNOW TO THE NORTHWEST
OF THE I-95 CORRIDOR...BUT THE BEST LIFT IS FOCUSED JUST SOUTHEAST
OF THIS AREA...AND THE SYSTEM COULD TRACK FURTHER TO THE SOUTH PER
12Z UKMET MODEL. STILL A LOT OF UNCERTAINTY WITH ULTIMATE TRACK.

WEDNESDAY...
A MID-LEVEL RIDGE WILL MOVE THROUGH THE REGION TUESDAY NIGHT INTO
EARLY WEDNESDAY LEADING TO A BRIEF RESPITE BETWEEN WEATHER SYSTEMS.
THEN A MID-LEVEL TROUGH IS PROJECTED TO BECOME NEGATIVELY TILTED
OVER THE OHIO VALLEY ON WED...LEADING TO A MERIDIONAL FLOW ALONG
THE EAST COAST...WITH THE ENTIRE COLUMN EXPECTED TO BE WELL ABOVE
FREEZING ACROSS THE CWA FAVORING A RAIN EVENT. THERE ARE SEVERAL
INGREDIENTS COMING TOGETHER FOR HEAVY RAIN. IN PARTICULAR...DEEP
GULF MOISTURE...LOW-LEVEL ISENTROPIC LIFT...MID-LEVEL PVA...AND
THE RIGHT-REAR QUADRANT OF A 140 KNOT UPPER-LEVEL JET JUST NORTH.
THE SYSTEM SHOULD BE FAIRLY PROGRESSIVE BUT WILL HAVE TO MONITOR
POTENTIAL FOR FLOODING.

THU AND FRI...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS
TO BUILD IN. TEMPERATURES WILL RETURN TO SEASONABLE LEVELS AND
THERE COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW.

&&

.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THE 00Z TAFS TAKE CIGS DOWN TO MVFR LEVELS TONIGHT FROM THE KPHL
AREA AIRPORTS NORTHWESTWARD WITH IMPROVEMENT ON SATURDAY. ITS BEEN
TOUGH TO SHAKE THIS STRATOCU LEVEL CLOUDINESS PATTERN.

FOR TONIGHT. LOW CLOUDS ADVANCING IN FROM THE HIGHER TERRAIN
AIRPORTS ARE STILL HEADING INTO THE TERMINALS. WE BRING MVFR CIG
POTENTIAL FROM THE GET GO AT KABE AND KRDG (HIER CONFIDENCE
OVERNIGHT) AND BRING IT DOWN TO THE KPHL METRO AIRPORTS AFTER 05Z.
WE LEAVE KACY AND KMIV VFR. WINDS WILL BE LIGHT FROM THE
NORTHWEST. NO VSBY RESTRICTIONS EXPECTED.

ON SATURDAY, PREDICTING THE MVFR CIG TO BECOME SCATTERED DURING
THE MORNING FROM THE KPHL METRO AIRPORTS NWWD WITH A CIRRUS CIG
ABOVE. KACY AND KMIV NOT EXPECTING A MVFR CIG. IT WILL BE A WEAK
PRESSURE PATTERN AND WINDS WILL BE LIGHT. A NORTHERLY DIRECTION
IS FAVORED, BUT SPEEDS ARE EXPECTED TO REMAIN BELOW 10 KNOTS,
PROBABLY PREDOMINATELY LESS THAN 6 KNOTS AT SOME OF THE MORE
RURAL AIRPORTS AND TERMINALS.

OUTLOOK...
SATURDAY NIGHT AND SUNDAY...VFR CONDITIONS EXPECTED.
MONDAY AND TUESDAY...IFR POSSIBLE IN SHRA AND SHSN.
WEDNESDAY...IFR POSSIBLE IN RAIN AND FOG.

&&

.MARINE...
SUB-SCA CONDS ARE EXPECTED FOR THE NEXT 24 HOURS AT LEAST. SMWHT
GUST NW WINDS THIS EVENING WILL GRADUALLY DIMINISH TONIGHT THROUGH
SATURDAY AS A RIDGE OF HIGH PRES MOVES OVERHEAD. SEAS ARE
CURRENTLY RUNNING 2 TO 3 FT BUT THEY SHOULD GRADUALLY DIMINISH
ALSO.

OUTLOOK...
SUNDAY AND MONDAY...SUB-SCA CONDITIONS EXPECTED.
TUESDAY...SCA MAY BE NEEDED FOR BUILDING SEAS.
WEDNESDAY...GALE WARNING MAY BE NEEDED.

&&

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

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...AMC/GIGI
SHORT TERM...AMC
LONG TERM...FRANCK
AVIATION...FRANCK/GIGI
MARINE...AMC/FRANCK







000
FXUS61 KPBZ 192320
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
620 PM EST FRI DEC 19 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WITH 615PM UPDATE...HAVE MADE ONLY MINOR CHANGES TO SKY AND
HOURLY TEMPERATURE FORECASTS. STRATUS HAS NOT SHOWN ANY SIGNS OF
SCATTERING OUT YET...AND WILL CONTINUE MOSTLY CLOUDY FORECAST AT
THIS POINT. PREVIOUS DISCUSSION FOLLOWS.

THE UPPER TROUGH WILL DEPART EAST AND BE REPLACED BY RIDGING
TONIGHT. MODEL PROFILES SUGGEST THAT SOME MOISTURE WILL REMAIN
TRAPPED UNDER THE BUILDING UPPER RIDGE...PREVENTING US FROM
CLEARING OUT THIS EVENING. THIS ISN`T COMPLETELY CLEAR CUT...BUT
WILL OPT TO KEEP MOSTLY CLOUDY WORDING UNLESS SATELLITE
OBSERVATIONS SHOW OTHERWISE. DID DROP TEMPS FOR THE REST OF THE
AFTERNOON AS CLOUD COVER SHOULD KEEP TEMPERATURES FROM WARMING
MUCH ABOVE CURRENT VALUES. LOWS TONIGHT WERE KEPT NEAR MET
GUIDANCE.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
HIGH PRESSURE RIDGE WILL SETTLE OVER THE NORTHEASTERN CONUS FOR
MUCH OF THE WEEKEND. A FAST MOVING SYSTEM WILL BE SUPPRESSED TO
THE SOUTH SATURDAY BUT SOME MID-HIGH DECK MAY REPLACE THE LOW
DECK...MAINTAINING MOSTLY CLOUDY SKIES THROUGH MUCH OF THE DAY.
WITH NEARLY STAGNANT 850HPA TEMPERATURES AND MINIMAL SUN
TOMORROW...EXPECT HIGHS WILL NOT SURPASS THE LOW TO MID 30`S.
HOWEVER...SOUTHERLY FLOW AND WARM ADVECTION WILL RETURN FOR SUNDAY
AND MONDAY BRINGING TEMPERATURES TO NEAR OR JUST ABOVE NORMAL
VALUES.

ON MONDAY...WE WILL BE IN THE SQUEEZE BETWEEN TWO SYSTEMS. ONE LOW
WILL BE DEVELOPING ALONG THE GULF COAST...WHILE ANOTHER LOW AND
DEEPENING UPPER TROUGH WILL SINK SOUTHWARD OVER THE CENTRAL US.
THIS LOW OVER THE CENTRAL PLAINS WILL HELP TO AMPLIFY THE UPPER
PATTERN...EJECTING THE SOUTHERN SYSTEM NORTHWARD. AT THIS POINT
THE BULK OF THE MOISTURE WITH THE SOUTHERN SYSTEM SHOULD REMAIN
EAST...JUST BRUSHING OUR EASTERN MOUNTAINS OF WV/MD UNTIL THE COLD
FRONT WITH THE DEEPENING LOW APPROACHES. MAINTAINED CHANCE POPS
FOR THE RIDGES WITH LOWER POPS FURTHER NORTH AND WEST THROUGH
MONDAY. WHILE THE MID LEVELS WILL BE WARMING...CANNOT RULE OUT A
RAIN/SNOW MIX INITIALLY MONDAY MORNING OVER THE RIDGES BEFORE
CHANGING TO ALL RAIN. SOME FREEZING RAIN COULD ALSO BE OF CONCERN
IN ANY SHELTERED VALLEYS...BUT FOR NOW WILL LEAVE THIS OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS ARE IN GENERAL AGREEMENT ON DEEPENING UPPER LEVEL CLOSED LOW
OVER THE GREAT LAKES TUESDAY THROUGH THURSDAY WITH PERIODS OF RAIN
INTO WEDNESDAY UNTIL COLD FRONT WILL CHANGE PRECIP OVER TO SNOW
SHOWERS LATER WEDNESDAY AND THURSDAY. WINDS WILL BE ON THE
INCREASE THURSDAY AS SURFACE LOW WRAPS UP NORTH OF THE REGION. QPF
ON THE FRONT SIDE OF SYSTEM WILL BE NEAR AN INCH...WHICH SHOULD
NOT PRODUCE ANY SIGNIFICANT PROBLEMS. BACKLASH SNOW WEDNESDAY
NIGHT INTO THURSDAY WILL BE LIGHT WITH ONLY MINOR ACCUMULATIONS
EXPECTED. FLOW BEHIND COLD FRONT LOOKS TO STAY SOUTHWESTERLY WHICH
LOOKS TO LIMIT LAKE ENHANCED AMOUNTS ALONG I-80 AND THE RIDGES.
COLDER TEMPERATURES WILL THEN MODERATE FRIDAY AS MID LEVEL FLOW
QUICKLY BECOMES ZONAL.

&&

.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
PERVASIVE STRATUS COVERS ALL SITES THIS EVENING...WHILE BOUNDARY
LAYER MOISTURE HAS DROPPED OFF FROM EARLIER TODAY. GIVEN STRONG
INVERSIONS...STRATUS SEEMS LIKELY TO CONTINUE FOR THE NEXT DAY AT
LEAST...HOWEVER GIVEN A BIT WIDER DEWPOINT DEPRESSIONS...LIGHT
PRECIPITATION CHANCES SEEM VERY LOW. MVFR CONDITIONS SEEM LIKELY
TO CONTINUE. FRIES


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$







000
FXUS61 KPBZ 192320
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
620 PM EST FRI DEC 19 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WITH 615PM UPDATE...HAVE MADE ONLY MINOR CHANGES TO SKY AND
HOURLY TEMPERATURE FORECASTS. STRATUS HAS NOT SHOWN ANY SIGNS OF
SCATTERING OUT YET...AND WILL CONTINUE MOSTLY CLOUDY FORECAST AT
THIS POINT. PREVIOUS DISCUSSION FOLLOWS.

THE UPPER TROUGH WILL DEPART EAST AND BE REPLACED BY RIDGING
TONIGHT. MODEL PROFILES SUGGEST THAT SOME MOISTURE WILL REMAIN
TRAPPED UNDER THE BUILDING UPPER RIDGE...PREVENTING US FROM
CLEARING OUT THIS EVENING. THIS ISN`T COMPLETELY CLEAR CUT...BUT
WILL OPT TO KEEP MOSTLY CLOUDY WORDING UNLESS SATELLITE
OBSERVATIONS SHOW OTHERWISE. DID DROP TEMPS FOR THE REST OF THE
AFTERNOON AS CLOUD COVER SHOULD KEEP TEMPERATURES FROM WARMING
MUCH ABOVE CURRENT VALUES. LOWS TONIGHT WERE KEPT NEAR MET
GUIDANCE.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
HIGH PRESSURE RIDGE WILL SETTLE OVER THE NORTHEASTERN CONUS FOR
MUCH OF THE WEEKEND. A FAST MOVING SYSTEM WILL BE SUPPRESSED TO
THE SOUTH SATURDAY BUT SOME MID-HIGH DECK MAY REPLACE THE LOW
DECK...MAINTAINING MOSTLY CLOUDY SKIES THROUGH MUCH OF THE DAY.
WITH NEARLY STAGNANT 850HPA TEMPERATURES AND MINIMAL SUN
TOMORROW...EXPECT HIGHS WILL NOT SURPASS THE LOW TO MID 30`S.
HOWEVER...SOUTHERLY FLOW AND WARM ADVECTION WILL RETURN FOR SUNDAY
AND MONDAY BRINGING TEMPERATURES TO NEAR OR JUST ABOVE NORMAL
VALUES.

ON MONDAY...WE WILL BE IN THE SQUEEZE BETWEEN TWO SYSTEMS. ONE LOW
WILL BE DEVELOPING ALONG THE GULF COAST...WHILE ANOTHER LOW AND
DEEPENING UPPER TROUGH WILL SINK SOUTHWARD OVER THE CENTRAL US.
THIS LOW OVER THE CENTRAL PLAINS WILL HELP TO AMPLIFY THE UPPER
PATTERN...EJECTING THE SOUTHERN SYSTEM NORTHWARD. AT THIS POINT
THE BULK OF THE MOISTURE WITH THE SOUTHERN SYSTEM SHOULD REMAIN
EAST...JUST BRUSHING OUR EASTERN MOUNTAINS OF WV/MD UNTIL THE COLD
FRONT WITH THE DEEPENING LOW APPROACHES. MAINTAINED CHANCE POPS
FOR THE RIDGES WITH LOWER POPS FURTHER NORTH AND WEST THROUGH
MONDAY. WHILE THE MID LEVELS WILL BE WARMING...CANNOT RULE OUT A
RAIN/SNOW MIX INITIALLY MONDAY MORNING OVER THE RIDGES BEFORE
CHANGING TO ALL RAIN. SOME FREEZING RAIN COULD ALSO BE OF CONCERN
IN ANY SHELTERED VALLEYS...BUT FOR NOW WILL LEAVE THIS OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS ARE IN GENERAL AGREEMENT ON DEEPENING UPPER LEVEL CLOSED LOW
OVER THE GREAT LAKES TUESDAY THROUGH THURSDAY WITH PERIODS OF RAIN
INTO WEDNESDAY UNTIL COLD FRONT WILL CHANGE PRECIP OVER TO SNOW
SHOWERS LATER WEDNESDAY AND THURSDAY. WINDS WILL BE ON THE
INCREASE THURSDAY AS SURFACE LOW WRAPS UP NORTH OF THE REGION. QPF
ON THE FRONT SIDE OF SYSTEM WILL BE NEAR AN INCH...WHICH SHOULD
NOT PRODUCE ANY SIGNIFICANT PROBLEMS. BACKLASH SNOW WEDNESDAY
NIGHT INTO THURSDAY WILL BE LIGHT WITH ONLY MINOR ACCUMULATIONS
EXPECTED. FLOW BEHIND COLD FRONT LOOKS TO STAY SOUTHWESTERLY WHICH
LOOKS TO LIMIT LAKE ENHANCED AMOUNTS ALONG I-80 AND THE RIDGES.
COLDER TEMPERATURES WILL THEN MODERATE FRIDAY AS MID LEVEL FLOW
QUICKLY BECOMES ZONAL.

&&

.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
PERVASIVE STRATUS COVERS ALL SITES THIS EVENING...WHILE BOUNDARY
LAYER MOISTURE HAS DROPPED OFF FROM EARLIER TODAY. GIVEN STRONG
INVERSIONS...STRATUS SEEMS LIKELY TO CONTINUE FOR THE NEXT DAY AT
LEAST...HOWEVER GIVEN A BIT WIDER DEWPOINT DEPRESSIONS...LIGHT
PRECIPITATION CHANCES SEEM VERY LOW. MVFR CONDITIONS SEEM LIKELY
TO CONTINUE. FRIES


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$






000
FXUS61 KPBZ 192113
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
413 PM EST FRI DEC 19 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE UPPER TROUGH WILL DEPART EAST AND BE REPLACED BY RIDGING
TONIGHT. MODEL PROFILES SUGGEST THAT SOME MOISTURE WILL REMAIN
TRAPPED UNDER THE BUILDING UPPER RIDGE...PREVENTING US FROM
CLEARING OUT THIS EVENING. THIS ISN`T COMPLETELY CLEAR CUT...BUT
WILL OPT TO KEEP MOSTLY CLOUDY WORDING UNLESS SATELLITE
OBSERVATIONS SHOW OTHERWISE. DID DROP TEMPS FOR THE REST OF THE
AFTERNOON AS CLOUD COVER SHOULD KEEP TEMPERATURES FROM WARMING
MUCH ABOVE CURRENT VALUES. LOWS TONIGHT WERE KEPT NEAR MET
GUIDANCE.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
HIGH PRESSURE RIDGE WILL SETTLE OVER THE NORTHEASTERN CONUS FOR
MUCH OF THE WEEKEND. A FAST MOVING SYSTEM WILL BE SUPPRESSED TO
THE SOUTH SATURDAY BUT SOME MID-HIGH DECK MAY REPLACE THE LOW
DECK...MAINTAINING MOSTLY CLOUDY SKIES THROUGH MUCH OF THE DAY.
WITH NEARLY STAGNANT 850HPA TEMPERATURES AND MINIMAL SUN
TOMORROW...EXPECT HIGHS WILL NOT SURPASS THE LOW TO MID 30`S.
HOWEVER...SOUTHERLY FLOW AND WARM ADVECTION WILL RETURN FOR SUNDAY
AND MONDAY BRINGING TEMPERATURES TO NEAR OR JUST ABOVE NORMAL
VALUES.

ON MONDAY...WE WILL BE IN THE SQUEEZE BETWEEN TWO SYSTEMS. ONE LOW
WILL BE DEVELOPING ALONG THE GULF COAST...WHILE ANOTHER LOW AND
DEEPENING UPPER TROUGH WILL SINK SOUTHWARD OVER THE CENTRAL US.
THIS LOW OVER THE CENTRAL PLAINS WILL HELP TO AMPLIFY THE UPPER
PATTERN...EJECTING THE SOUTHERN SYSTEM NORTHWARD. AT THIS POINT
THE BULK OF THE MOISTURE WITH THE SOUTHERN SYSTEM SHOULD REMAIN
EAST...JUST BRUSHING OUR EASTERN MOUNTAINS OF WV/MD UNTIL THE COLD
FRONT WITH THE DEEPENING LOW APPROACHES. MAINTAINED CHANCE POPS
FOR THE RIDGES WITH LOWER POPS FURTHER NORTH AND WEST THROUGH
MONDAY. WHILE THE MID LEVELS WILL BE WARMING...CANNOT RULE OUT A
RAIN/SNOW MIX INITIALLY MONDAY MORNING OVER THE RIDGES BEFORE
CHANGING TO ALL RAIN. SOME FREEZING RAIN COULD ALSO BE OF CONCERN
IN ANY SHELTERED VALLEYS...BUT FOR NOW WILL LEAVE THIS OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS ARE IN GENERAL AGREEMENT ON DEEPENING UPPER LEVEL CLOSED LOW
OVER THE GREAT LAKES TUESDAY THROUGH THURSDAY WITH PERIODS OF RAIN
INTO WEDNESDAY UNTIL COLD FRONT WILL CHANGE PRECIP OVER TO SNOW
SHOWERS LATER WEDNESDAY AND THURSDAY. WINDS WILL BE ON THE
INCREASE THURSDAY AS SURFACE LOW WRAPS UP NORTH OF THE REGION. QPF
ON THE FRONT SIDE OF SYSTEM WILL BE NEAR AN INCH...WHICH SHOULD
NOT PRODUCE ANY SIGNIFICANT PROBLEMS. BACKLASH SNOW WEDNESDAY
NIGHT INTO THURSDAY WILL BE LIGHT WITH ONLY MINOR ACCUMULATIONS
EXPECTED. FLOW BEHIND COLD FRONT LOOKS TO STAY SOUTHWESTERLY WHICH
LOOKS TO LIMIT LAKE ENHANCED AMOUNTS ALONG I-80 AND THE RIDGES.
COLDER TEMPERATURES WILL THEN MODERATE FRIDAY AS MID LEVEL FLOW
QUICKLY BECOMES ZONAL.

&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
GENERAL MVFR EXPECTED THROUGH TONIGHT.


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$











000
FXUS61 KPBZ 192113
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
413 PM EST FRI DEC 19 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE UPPER TROUGH WILL DEPART EAST AND BE REPLACED BY RIDGING
TONIGHT. MODEL PROFILES SUGGEST THAT SOME MOISTURE WILL REMAIN
TRAPPED UNDER THE BUILDING UPPER RIDGE...PREVENTING US FROM
CLEARING OUT THIS EVENING. THIS ISN`T COMPLETELY CLEAR CUT...BUT
WILL OPT TO KEEP MOSTLY CLOUDY WORDING UNLESS SATELLITE
OBSERVATIONS SHOW OTHERWISE. DID DROP TEMPS FOR THE REST OF THE
AFTERNOON AS CLOUD COVER SHOULD KEEP TEMPERATURES FROM WARMING
MUCH ABOVE CURRENT VALUES. LOWS TONIGHT WERE KEPT NEAR MET
GUIDANCE.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
HIGH PRESSURE RIDGE WILL SETTLE OVER THE NORTHEASTERN CONUS FOR
MUCH OF THE WEEKEND. A FAST MOVING SYSTEM WILL BE SUPPRESSED TO
THE SOUTH SATURDAY BUT SOME MID-HIGH DECK MAY REPLACE THE LOW
DECK...MAINTAINING MOSTLY CLOUDY SKIES THROUGH MUCH OF THE DAY.
WITH NEARLY STAGNANT 850HPA TEMPERATURES AND MINIMAL SUN
TOMORROW...EXPECT HIGHS WILL NOT SURPASS THE LOW TO MID 30`S.
HOWEVER...SOUTHERLY FLOW AND WARM ADVECTION WILL RETURN FOR SUNDAY
AND MONDAY BRINGING TEMPERATURES TO NEAR OR JUST ABOVE NORMAL
VALUES.

ON MONDAY...WE WILL BE IN THE SQUEEZE BETWEEN TWO SYSTEMS. ONE LOW
WILL BE DEVELOPING ALONG THE GULF COAST...WHILE ANOTHER LOW AND
DEEPENING UPPER TROUGH WILL SINK SOUTHWARD OVER THE CENTRAL US.
THIS LOW OVER THE CENTRAL PLAINS WILL HELP TO AMPLIFY THE UPPER
PATTERN...EJECTING THE SOUTHERN SYSTEM NORTHWARD. AT THIS POINT
THE BULK OF THE MOISTURE WITH THE SOUTHERN SYSTEM SHOULD REMAIN
EAST...JUST BRUSHING OUR EASTERN MOUNTAINS OF WV/MD UNTIL THE COLD
FRONT WITH THE DEEPENING LOW APPROACHES. MAINTAINED CHANCE POPS
FOR THE RIDGES WITH LOWER POPS FURTHER NORTH AND WEST THROUGH
MONDAY. WHILE THE MID LEVELS WILL BE WARMING...CANNOT RULE OUT A
RAIN/SNOW MIX INITIALLY MONDAY MORNING OVER THE RIDGES BEFORE
CHANGING TO ALL RAIN. SOME FREEZING RAIN COULD ALSO BE OF CONCERN
IN ANY SHELTERED VALLEYS...BUT FOR NOW WILL LEAVE THIS OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS ARE IN GENERAL AGREEMENT ON DEEPENING UPPER LEVEL CLOSED LOW
OVER THE GREAT LAKES TUESDAY THROUGH THURSDAY WITH PERIODS OF RAIN
INTO WEDNESDAY UNTIL COLD FRONT WILL CHANGE PRECIP OVER TO SNOW
SHOWERS LATER WEDNESDAY AND THURSDAY. WINDS WILL BE ON THE
INCREASE THURSDAY AS SURFACE LOW WRAPS UP NORTH OF THE REGION. QPF
ON THE FRONT SIDE OF SYSTEM WILL BE NEAR AN INCH...WHICH SHOULD
NOT PRODUCE ANY SIGNIFICANT PROBLEMS. BACKLASH SNOW WEDNESDAY
NIGHT INTO THURSDAY WILL BE LIGHT WITH ONLY MINOR ACCUMULATIONS
EXPECTED. FLOW BEHIND COLD FRONT LOOKS TO STAY SOUTHWESTERLY WHICH
LOOKS TO LIMIT LAKE ENHANCED AMOUNTS ALONG I-80 AND THE RIDGES.
COLDER TEMPERATURES WILL THEN MODERATE FRIDAY AS MID LEVEL FLOW
QUICKLY BECOMES ZONAL.

&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
GENERAL MVFR EXPECTED THROUGH TONIGHT.


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$











000
FXUS61 KPBZ 192113
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
413 PM EST FRI DEC 19 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE UPPER TROUGH WILL DEPART EAST AND BE REPLACED BY RIDGING
TONIGHT. MODEL PROFILES SUGGEST THAT SOME MOISTURE WILL REMAIN
TRAPPED UNDER THE BUILDING UPPER RIDGE...PREVENTING US FROM
CLEARING OUT THIS EVENING. THIS ISN`T COMPLETELY CLEAR CUT...BUT
WILL OPT TO KEEP MOSTLY CLOUDY WORDING UNLESS SATELLITE
OBSERVATIONS SHOW OTHERWISE. DID DROP TEMPS FOR THE REST OF THE
AFTERNOON AS CLOUD COVER SHOULD KEEP TEMPERATURES FROM WARMING
MUCH ABOVE CURRENT VALUES. LOWS TONIGHT WERE KEPT NEAR MET
GUIDANCE.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
HIGH PRESSURE RIDGE WILL SETTLE OVER THE NORTHEASTERN CONUS FOR
MUCH OF THE WEEKEND. A FAST MOVING SYSTEM WILL BE SUPPRESSED TO
THE SOUTH SATURDAY BUT SOME MID-HIGH DECK MAY REPLACE THE LOW
DECK...MAINTAINING MOSTLY CLOUDY SKIES THROUGH MUCH OF THE DAY.
WITH NEARLY STAGNANT 850HPA TEMPERATURES AND MINIMAL SUN
TOMORROW...EXPECT HIGHS WILL NOT SURPASS THE LOW TO MID 30`S.
HOWEVER...SOUTHERLY FLOW AND WARM ADVECTION WILL RETURN FOR SUNDAY
AND MONDAY BRINGING TEMPERATURES TO NEAR OR JUST ABOVE NORMAL
VALUES.

ON MONDAY...WE WILL BE IN THE SQUEEZE BETWEEN TWO SYSTEMS. ONE LOW
WILL BE DEVELOPING ALONG THE GULF COAST...WHILE ANOTHER LOW AND
DEEPENING UPPER TROUGH WILL SINK SOUTHWARD OVER THE CENTRAL US.
THIS LOW OVER THE CENTRAL PLAINS WILL HELP TO AMPLIFY THE UPPER
PATTERN...EJECTING THE SOUTHERN SYSTEM NORTHWARD. AT THIS POINT
THE BULK OF THE MOISTURE WITH THE SOUTHERN SYSTEM SHOULD REMAIN
EAST...JUST BRUSHING OUR EASTERN MOUNTAINS OF WV/MD UNTIL THE COLD
FRONT WITH THE DEEPENING LOW APPROACHES. MAINTAINED CHANCE POPS
FOR THE RIDGES WITH LOWER POPS FURTHER NORTH AND WEST THROUGH
MONDAY. WHILE THE MID LEVELS WILL BE WARMING...CANNOT RULE OUT A
RAIN/SNOW MIX INITIALLY MONDAY MORNING OVER THE RIDGES BEFORE
CHANGING TO ALL RAIN. SOME FREEZING RAIN COULD ALSO BE OF CONCERN
IN ANY SHELTERED VALLEYS...BUT FOR NOW WILL LEAVE THIS OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS ARE IN GENERAL AGREEMENT ON DEEPENING UPPER LEVEL CLOSED LOW
OVER THE GREAT LAKES TUESDAY THROUGH THURSDAY WITH PERIODS OF RAIN
INTO WEDNESDAY UNTIL COLD FRONT WILL CHANGE PRECIP OVER TO SNOW
SHOWERS LATER WEDNESDAY AND THURSDAY. WINDS WILL BE ON THE
INCREASE THURSDAY AS SURFACE LOW WRAPS UP NORTH OF THE REGION. QPF
ON THE FRONT SIDE OF SYSTEM WILL BE NEAR AN INCH...WHICH SHOULD
NOT PRODUCE ANY SIGNIFICANT PROBLEMS. BACKLASH SNOW WEDNESDAY
NIGHT INTO THURSDAY WILL BE LIGHT WITH ONLY MINOR ACCUMULATIONS
EXPECTED. FLOW BEHIND COLD FRONT LOOKS TO STAY SOUTHWESTERLY WHICH
LOOKS TO LIMIT LAKE ENHANCED AMOUNTS ALONG I-80 AND THE RIDGES.
COLDER TEMPERATURES WILL THEN MODERATE FRIDAY AS MID LEVEL FLOW
QUICKLY BECOMES ZONAL.

&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
GENERAL MVFR EXPECTED THROUGH TONIGHT.


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$











000
FXUS61 KPBZ 192113
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
413 PM EST FRI DEC 19 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE UPPER TROUGH WILL DEPART EAST AND BE REPLACED BY RIDGING
TONIGHT. MODEL PROFILES SUGGEST THAT SOME MOISTURE WILL REMAIN
TRAPPED UNDER THE BUILDING UPPER RIDGE...PREVENTING US FROM
CLEARING OUT THIS EVENING. THIS ISN`T COMPLETELY CLEAR CUT...BUT
WILL OPT TO KEEP MOSTLY CLOUDY WORDING UNLESS SATELLITE
OBSERVATIONS SHOW OTHERWISE. DID DROP TEMPS FOR THE REST OF THE
AFTERNOON AS CLOUD COVER SHOULD KEEP TEMPERATURES FROM WARMING
MUCH ABOVE CURRENT VALUES. LOWS TONIGHT WERE KEPT NEAR MET
GUIDANCE.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
HIGH PRESSURE RIDGE WILL SETTLE OVER THE NORTHEASTERN CONUS FOR
MUCH OF THE WEEKEND. A FAST MOVING SYSTEM WILL BE SUPPRESSED TO
THE SOUTH SATURDAY BUT SOME MID-HIGH DECK MAY REPLACE THE LOW
DECK...MAINTAINING MOSTLY CLOUDY SKIES THROUGH MUCH OF THE DAY.
WITH NEARLY STAGNANT 850HPA TEMPERATURES AND MINIMAL SUN
TOMORROW...EXPECT HIGHS WILL NOT SURPASS THE LOW TO MID 30`S.
HOWEVER...SOUTHERLY FLOW AND WARM ADVECTION WILL RETURN FOR SUNDAY
AND MONDAY BRINGING TEMPERATURES TO NEAR OR JUST ABOVE NORMAL
VALUES.

ON MONDAY...WE WILL BE IN THE SQUEEZE BETWEEN TWO SYSTEMS. ONE LOW
WILL BE DEVELOPING ALONG THE GULF COAST...WHILE ANOTHER LOW AND
DEEPENING UPPER TROUGH WILL SINK SOUTHWARD OVER THE CENTRAL US.
THIS LOW OVER THE CENTRAL PLAINS WILL HELP TO AMPLIFY THE UPPER
PATTERN...EJECTING THE SOUTHERN SYSTEM NORTHWARD. AT THIS POINT
THE BULK OF THE MOISTURE WITH THE SOUTHERN SYSTEM SHOULD REMAIN
EAST...JUST BRUSHING OUR EASTERN MOUNTAINS OF WV/MD UNTIL THE COLD
FRONT WITH THE DEEPENING LOW APPROACHES. MAINTAINED CHANCE POPS
FOR THE RIDGES WITH LOWER POPS FURTHER NORTH AND WEST THROUGH
MONDAY. WHILE THE MID LEVELS WILL BE WARMING...CANNOT RULE OUT A
RAIN/SNOW MIX INITIALLY MONDAY MORNING OVER THE RIDGES BEFORE
CHANGING TO ALL RAIN. SOME FREEZING RAIN COULD ALSO BE OF CONCERN
IN ANY SHELTERED VALLEYS...BUT FOR NOW WILL LEAVE THIS OUT.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS ARE IN GENERAL AGREEMENT ON DEEPENING UPPER LEVEL CLOSED LOW
OVER THE GREAT LAKES TUESDAY THROUGH THURSDAY WITH PERIODS OF RAIN
INTO WEDNESDAY UNTIL COLD FRONT WILL CHANGE PRECIP OVER TO SNOW
SHOWERS LATER WEDNESDAY AND THURSDAY. WINDS WILL BE ON THE
INCREASE THURSDAY AS SURFACE LOW WRAPS UP NORTH OF THE REGION. QPF
ON THE FRONT SIDE OF SYSTEM WILL BE NEAR AN INCH...WHICH SHOULD
NOT PRODUCE ANY SIGNIFICANT PROBLEMS. BACKLASH SNOW WEDNESDAY
NIGHT INTO THURSDAY WILL BE LIGHT WITH ONLY MINOR ACCUMULATIONS
EXPECTED. FLOW BEHIND COLD FRONT LOOKS TO STAY SOUTHWESTERLY WHICH
LOOKS TO LIMIT LAKE ENHANCED AMOUNTS ALONG I-80 AND THE RIDGES.
COLDER TEMPERATURES WILL THEN MODERATE FRIDAY AS MID LEVEL FLOW
QUICKLY BECOMES ZONAL.

&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
GENERAL MVFR EXPECTED THROUGH TONIGHT.


OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$











000
FXUS61 KAKQ 192104
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
404 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST LATE TONIGHT THROUGH SATURDAY NIGHT. 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 COAST LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH SATURDAY/...
LATEST SFC ANALYSIS DEPICTS ~995 MB LO PRES OVER THE CANADIAN
MARITIMES WITH BROAD ~1028 MB HI PRES CENTERED OVER THE MIDWEST...RIDGING
ESE INTO THE MID ATLC STATES. WEAK LOW PRESSURE IS ALSO DEVELOPING
ACRS THE WRN GULF OF MEXICO...WITH PRECIP OVER LA/MS/AL AS OF 20Z
THIS AFTN. STILL MAINLY CLEAR SKIES OVER THE AKQ FORECAST AREA...BUT
SOME HIGH CIRRUS HAS STARTED TO OVERSPREAD THE REGION FROM THE SW
(AND BKN/OVC STRATO-CU HAS BEEN SLOW TO ERODE OVER THE ERN SHORE.
CURRENT TEMPS ARE GENLY IN THE 40S...AS CHILLY AS THE UPPER 30S AT
KWAL/KOXB IN THE CLOUDS...AND AS WARM AS AROUND 50 OVER NE NC AND
SOUTH CENTRAL VA.

FOR TONIGHT...DRY WX WILL PERSIST EVEN AS HIGH CLOUDS GRADUALLY
THICKEN/LOWER OVERNIGHT. EXPECT TEMPS TO RAPIDLY DROP AFTER SUNSET
UNDER MAINLY CLEAR SKIES...THEN BECOME NEARLY STEADY OVERNIGHT AS
CLOUDS SLOWLY INCREASE. LOWS MID 20S TO LOWER 30S.

SAT...SYSTEM FROM THE GULF CONTINUES TO REMAIN SHUNTED OFF TO OUR
SOUTH AS MID LEVEL FLOW REMAINS FAIRLY ZONAL. NAM/GFS STILL SHOW
SOME FORCING ALOFT MAKING WAY INTO PIEDMONT BETWEEN 12-18Z/SAT AND
BUFKIT SOUNDINGS SHOW SOME MODEST LIFT THROUGH THE DENDRITIC
GROWTH LAYER. PTYPE ACRS THE PIEDMONT WOULD TEND TO BE SNOW/SLEET
SAT AM ALTHOUGH SFC TEMPS SHOULD BE ABOVE 32 F (SFC WET BULBS IN
THE UPPER 20S INITIALLY). LOW LEVELS REMAIN QUITE DRY HOWEVER...SO ANY
PRECIP WILL BE VERY LIGHT (GENLY A FEW HUNDREDTHS IF THAT...WITH A
TRACE MORE LIKELY). THUS...WILL ONLY GO WITH 30% POPS AT MOST. BY
LATE MORNING/EARLY AFTN...AREA OF FORCING OVER THE PIEDMONT/CENTRAL
VA WEAKENS AS THE SFC LOW PUSHES OFF THE SE COAST. WILL CARRY LOW
CHC POPS IN FAR SE ZONES (ALL RAIN) THROUGH THE AFTN (ALTHOUGH
MOST OF THE PRECIP SHOULD STAY S OF THE CWA). CLOUDY TO MSTLY
CLOUDY W/ HIGHS GENLY 40-45 F SAT.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
SFC HIGH PRESSURE NOSES SOUTH INTO THE REGION SAT NIGHT/SUN...WITH DRY
CONDS THEN FOR SAT NGT AND SUN. LOWS IN THE 20S N TO THE 30S SE
SAT NIGHT...WITH HIGHS MAINLY FROM 45-50 F ON SUN. NEXT SYSTEM...THIS
ONE MORE AMPLIFIED WILL AFFECT THE AREA ON MON...WITH LIKELY POPS
ALL ZONES BY LATE MON AM/MON AFTN. LOOKS LIKE ALL RAIN ASIDE FROM
A BRIEF MIX POSSIBLE AT ONSET IN FAR NW COUNTIES. HIGHS MON ONLY
AROUND 40 F 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 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 /21Z FRIDAY THROUGH WEDNESDAY/...
THERE IS A VERY DISTINCT BOUNDARY BTWN BKN-OVC STRATOCUMULUS
(AROUND 3500 FT AGL) OVER NRN VA AND THE MD/VA LOWER EASTERN
SHORE VERSUS THE REST OF THE REGION...WHERE AN AREA OF SUBSIDENCE
PASSING FROM WEST TO EAST IS KEEPING SKIES CLEAR. IN ADDITION...NW
WINDS ARE GUSTING TO 15-20 KT WITHIN AND JUST SOUTH OF THE STRATUS
DECK. THE GUSTY WINDS WILL CALM DOWN BY SUNSET BUT THE STRATUS
WILL REMAIN STEADFAST THROUGH TONIGHT INTO SATURDAY MORNING. WINDS
AT KORF TURN MORE TO THE NORTH OVERNIGHT AND A STRATUS DECK AROUND
2000 FT AGL COULD DEVELOP OFF THE BAY. OTHERWISE...HIGH CLOUDS
WILL INCREASE ACROSS THE REGION FROM THE SW AFTER 20/0700Z TONIGHT.

LOW PRESSURE TRACKS WELL SOUTH OF THE AREA SAT/SAT NIGHT WITH
CLOUDS THICKENING AND LOWERING AS SATURDAY PROGRESSES. STEADY
PRECIPITATION WILL BE SHUNTED WELL SOUTH OF THE AREA...HOWEVER
THERE IS A SLIGHT CHANCE FOR RAIN SHOWERS ALONG AND SOUTH OF THE
VA/NC BORDER FROM LATE MORNING THROUGH THE AFTN. PRECIP COMES TO
AN END 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...
HIGH PRESSURE REMAINS NW OF THE REGION TONIGHT...WITH LINGERING
LIGHT CAA ALONG THE COAST. THIS WILL MAINTAIN A 10-15KT NNW WIND
OVERNIGHT...WITH 2-3FT SEAS IN THE OCEAN AND 1-2FT WAVES IN THE BAY.
HIGH PRESSURE SPREADS ACROSS NEW ENGLAND SATURDAY AND SATURDAY
NIGHT...WITH THE SURFACE RIDGE AXIS REMAINING INLAND OVER THE
PIEDMONT. THIS WILL MAINTAIN LIGHT (5-10KT) NORTHERLY FLOW OVER THE
MARINE AREA. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY
NIGHT...AS LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY
NIGHT...AND THEN TRACKS NE OFF THE MID ATLANTIC COAST MONDAY AND
MONDAY NIGHT. THE SURFACE PRESSURE GRADIENT TIGHTENS AHEAD OF THE
LOW MONDAY...WHICH HAS THE POTENTIAL TO PRODUCE 15-20KT EASTERLY
FLOW OVER THE OCEAN AND LOWER BAY. THIS ONSHORE FLOW 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 LATER MONDAY
NIGHT INTO TUESDAY. A STRONG LOW PRESSURE SYSTEM TRACKS W OF THE
MOUNTAINS TUESDAY NIGHT...WITH A STRONG COLD FRONT CROSSING 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...LKB/MAS
LONG TERM...AJZ/MAS
AVIATION...BMD/MPR
MARINE...AJZ






000
FXUS61 KAKQ 192104
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
404 PM EST FRI DEC 19 2014

.SYNOPSIS...
WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO EASTWARD AND
OFF THE SOUTHEAST COAST LATE TONIGHT THROUGH SATURDAY NIGHT. 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 COAST LATE SUNDAY NIGHT THROUGH MONDAY NIGHT.

&&

.NEAR TERM /THROUGH SATURDAY/...
LATEST SFC ANALYSIS DEPICTS ~995 MB LO PRES OVER THE CANADIAN
MARITIMES WITH BROAD ~1028 MB HI PRES CENTERED OVER THE MIDWEST...RIDGING
ESE INTO THE MID ATLC STATES. WEAK LOW PRESSURE IS ALSO DEVELOPING
ACRS THE WRN GULF OF MEXICO...WITH PRECIP OVER LA/MS/AL AS OF 20Z
THIS AFTN. STILL MAINLY CLEAR SKIES OVER THE AKQ FORECAST AREA...BUT
SOME HIGH CIRRUS HAS STARTED TO OVERSPREAD THE REGION FROM THE SW
(AND BKN/OVC STRATO-CU HAS BEEN SLOW TO ERODE OVER THE ERN SHORE.
CURRENT TEMPS ARE GENLY IN THE 40S...AS CHILLY AS THE UPPER 30S AT
KWAL/KOXB IN THE CLOUDS...AND AS WARM AS AROUND 50 OVER NE NC AND
SOUTH CENTRAL VA.

FOR TONIGHT...DRY WX WILL PERSIST EVEN AS HIGH CLOUDS GRADUALLY
THICKEN/LOWER OVERNIGHT. EXPECT TEMPS TO RAPIDLY DROP AFTER SUNSET
UNDER MAINLY CLEAR SKIES...THEN BECOME NEARLY STEADY OVERNIGHT AS
CLOUDS SLOWLY INCREASE. LOWS MID 20S TO LOWER 30S.

SAT...SYSTEM FROM THE GULF CONTINUES TO REMAIN SHUNTED OFF TO OUR
SOUTH AS MID LEVEL FLOW REMAINS FAIRLY ZONAL. NAM/GFS STILL SHOW
SOME FORCING ALOFT MAKING WAY INTO PIEDMONT BETWEEN 12-18Z/SAT AND
BUFKIT SOUNDINGS SHOW SOME MODEST LIFT THROUGH THE DENDRITIC
GROWTH LAYER. PTYPE ACRS THE PIEDMONT WOULD TEND TO BE SNOW/SLEET
SAT AM ALTHOUGH SFC TEMPS SHOULD BE ABOVE 32 F (SFC WET BULBS IN
THE UPPER 20S INITIALLY). LOW LEVELS REMAIN QUITE DRY HOWEVER...SO ANY
PRECIP WILL BE VERY LIGHT (GENLY A FEW HUNDREDTHS IF THAT...WITH A
TRACE MORE LIKELY). THUS...WILL ONLY GO WITH 30% POPS AT MOST. BY
LATE MORNING/EARLY AFTN...AREA OF FORCING OVER THE PIEDMONT/CENTRAL
VA WEAKENS AS THE SFC LOW PUSHES OFF THE SE COAST. WILL CARRY LOW
CHC POPS IN FAR SE ZONES (ALL RAIN) THROUGH THE AFTN (ALTHOUGH
MOST OF THE PRECIP SHOULD STAY S OF THE CWA). CLOUDY TO MSTLY
CLOUDY W/ HIGHS GENLY 40-45 F SAT.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
SFC HIGH PRESSURE NOSES SOUTH INTO THE REGION SAT NIGHT/SUN...WITH DRY
CONDS THEN FOR SAT NGT AND SUN. LOWS IN THE 20S N TO THE 30S SE
SAT NIGHT...WITH HIGHS MAINLY FROM 45-50 F ON SUN. NEXT SYSTEM...THIS
ONE MORE AMPLIFIED WILL AFFECT THE AREA ON MON...WITH LIKELY POPS
ALL ZONES BY LATE MON AM/MON AFTN. LOOKS LIKE ALL RAIN ASIDE FROM
A BRIEF MIX POSSIBLE AT ONSET IN FAR NW COUNTIES. HIGHS MON ONLY
AROUND 40 F 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 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 /21Z FRIDAY THROUGH WEDNESDAY/...
THERE IS A VERY DISTINCT BOUNDARY BTWN BKN-OVC STRATOCUMULUS
(AROUND 3500 FT AGL) OVER NRN VA AND THE MD/VA LOWER EASTERN
SHORE VERSUS THE REST OF THE REGION...WHERE AN AREA OF SUBSIDENCE
PASSING FROM WEST TO EAST IS KEEPING SKIES CLEAR. IN ADDITION...NW
WINDS ARE GUSTING TO 15-20 KT WITHIN AND JUST SOUTH OF THE STRATUS
DECK. THE GUSTY WINDS WILL CALM DOWN BY SUNSET BUT THE STRATUS
WILL REMAIN STEADFAST THROUGH TONIGHT INTO SATURDAY MORNING. WINDS
AT KORF TURN MORE TO THE NORTH OVERNIGHT AND A STRATUS DECK AROUND
2000 FT AGL COULD DEVELOP OFF THE BAY. OTHERWISE...HIGH CLOUDS
WILL INCREASE ACROSS THE REGION FROM THE SW AFTER 20/0700Z TONIGHT.

LOW PRESSURE TRACKS WELL SOUTH OF THE AREA SAT/SAT NIGHT WITH
CLOUDS THICKENING AND LOWERING AS SATURDAY PROGRESSES. STEADY
PRECIPITATION WILL BE SHUNTED WELL SOUTH OF THE AREA...HOWEVER
THERE IS A SLIGHT CHANCE FOR RAIN SHOWERS ALONG AND SOUTH OF THE
VA/NC BORDER FROM LATE MORNING THROUGH THE AFTN. PRECIP COMES TO
AN END 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...
HIGH PRESSURE REMAINS NW OF THE REGION TONIGHT...WITH LINGERING
LIGHT CAA ALONG THE COAST. THIS WILL MAINTAIN A 10-15KT NNW WIND
OVERNIGHT...WITH 2-3FT SEAS IN THE OCEAN AND 1-2FT WAVES IN THE BAY.
HIGH PRESSURE SPREADS ACROSS NEW ENGLAND SATURDAY AND SATURDAY
NIGHT...WITH THE SURFACE RIDGE AXIS REMAINING INLAND OVER THE
PIEDMONT. THIS WILL MAINTAIN LIGHT (5-10KT) NORTHERLY FLOW OVER THE
MARINE AREA. HIGH PRESSURE MOVES FARTHER E SUNDAY AND SUNDAY
NIGHT...AS LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST SUNDAY
NIGHT...AND THEN TRACKS NE OFF THE MID ATLANTIC COAST MONDAY AND
MONDAY NIGHT. THE SURFACE PRESSURE GRADIENT TIGHTENS AHEAD OF THE
LOW MONDAY...WHICH HAS THE POTENTIAL TO PRODUCE 15-20KT EASTERLY
FLOW OVER THE OCEAN AND LOWER BAY. THIS ONSHORE FLOW 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 LATER MONDAY
NIGHT INTO TUESDAY. A STRONG LOW PRESSURE SYSTEM TRACKS W OF THE
MOUNTAINS TUESDAY NIGHT...WITH A STRONG COLD FRONT CROSSING 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...LKB/MAS
LONG TERM...AJZ/MAS
AVIATION...BMD/MPR
MARINE...AJZ







000
FXUS61 KPHI 192051
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
351 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE JUST NORTH OF LAKE SUPERIOR WILL GRADUALLY MOVE
EASTWARD INTO NORTHERN NEW ENGLAND THRU MONDAY. A WAVE OF LOW
PRESSURE WILL FORM ALONG THE MID-ATLANTIC COASTLINE ON MONDAY
AND MOVE NORTHEASTWARD JUST OFFSHORE ON TUESDAY. MEANWHILE...
A STRONG AREA OF LOW-PRESSURE WILL FORM OVER THE MISSISSIPPI
VALLEY AND MOVE THRU THE GREAT LAKES REGION DURING THE MIDDLE
OF THE WEEK...BRINGING A STRONG COLD FRONT THRU THE REGION
BY THURSDAY. HIGH PRESSURE IS PROJECTED TO BUILD IN ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY/...
EXTENSIVE LOW CLOUD DECK THAT COVERED THE AREA THIS MORNING HAS
ERODED CONSIDERABLY THIS AFTN. CLOUD COVER PERSISTS OVER DELMARVA
AND OVER NWRN NJ AND ADJ PA. GIVEN THE NWLY LOW-LVL FLOW...THINK THE
CLOUDS DOWN SOUTH WILL CONT TO ERODE WHILE THE NRN AREA WILL BE MORE
PERSISTENT INTO THIS EVENING. TEMPS IN CLEARING AREAS HAVE RESPONDED
ONLY SLIGHTLY DUE TO THE LOW DEC SUN ANGLE.

FOR TONIGHT...NW WINDS WILL CONTINUE BUT WILL BECOME LIGHTER AS
CANADIAN LOW PRES MOVES AWAY AND HIGH PRES MOVES CLOSED WITH
RESULTING RELAXED PRES GRAD. MOSTLY CLEAR TO PARTLY CLOUDY SKIES
TONIGHT SHOULD ALLOW FOR DECENT COOLING WITH OVERNIGHT MINS GENLY 5
TO 10 DEGS COOLER THAN LAST NIGHT.

&&

.SHORT TERM /6 AM TO 6 PM SATURDAY/...
FOR SATURDAY...HIGH PRES CENTERED OVER CANADA SHIFTS EWD FROM
ONTARIO INTO QUEBEC. A RIDGE AXIS IS FCST TO EXTEND SWD THROUGH THE
MID-ATLANTIC REGION RESULTING IN ONLY LIGHT NLY WINDS. SOME LOW-LVL
MOISTURE SHOULD REMAIN TRAPPED BELOW THE LARGE-SCALE SUBSIDENCE
INVERSION BUT HARD TO SAY HOW EXTENSIVE ANY LOW CLOUDS MAY BE. THE
12-KM NAM SHOWS A THIN LOW CLOUD LAYER DEVELOPING DURG THE DAY BUT
HIGHER-RES ARW/NMM AND THE GFS DO NOT. THERE WILL BE SOME HIGHER
CLOUDS ALSO ASSOCD WITH THE SHRTWV NOW MOVING ENEWD OUT OF THE SRN
PLAINS...HWVR POPS REMAIN NEAR ZERO.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* SLIGHT CHANCE OF SNOW SHOWERS SUNDAY MORNING MAINLY NORTH.
* SNOW POSSIBLE NORTHWEST OF THE I-95 CORRIDOR LATE MONDAY
  THRU EARLY TUESDAY.
* POTENTIAL FOR HEAVY RAIN INCREASING ON CHRISTMAS EVE DAY.

OVERVIEW...

MID-LEVEL BLOCKING PATTERN OVER NOAM BEGINS TO DISLODGE IN RESPONSE
JET ENERGY MOVING INTO THE PACIFIC NORTHWEST THIS WEEKEND...CARVING
OUT A DEEP TROUGH OVER THE MS VALLEY EARLY EARLY NEXT WEEK...WHICH
LEADS TO INCLEMENT WEATHER IN THE TUESDAY THRU WEDNESDAY TIME FRAME.

DETAILS...

SUNDAY...
SHORTWAVE LIFTING THROUGH THE REGION EARLY IN THE DAY MAY GENERATE
ENOUGH LIFT ALONG WITH MARGINAL MOISTURE IN THE COLUMN TO PRODUCE
SOME LIGHT SNOW SHOWERS...MAINLY DURING THE PRE-DAWN HOURS. LITTLE
IF ANY ACCUMULATION EXPECTED AS MOISTURE IS VERY LIMITED. RIDGING
THEN BUILDS IN SO FAIR WEATHER IS EXPECTED THE REMAINDER OF THE DAY.

MONDAY AND TUESDAY...
HIGH PRESSURE ANCHORS ALONG THE LEE OF THE APPALACHIANS. A SOUTHERN
STREAM SHORTWAVE WILL INDUCE LOW-PRESSURE OF THE MID-ATLANTIC COAST.
MODELS BRING QPF NORTHWARD INTO THE AREA ON MONDAY NIGHT INTO EARLY
TUESDAY. THERMAL PROFILES ARE COLD ENOUGH FOR SNOW TO THE NORTHWEST
OF THE I-95 CORRIDOR...BUT THE BEST LIFT IS FOCUSED JUST SOUTHEAST
OF THIS AREA...AND THE SYSTEM COULD TRACK FURTHER TO THE SOUTH PER
12Z UKMET MODEL. STILL A LOT OF UNCERTAINTY WITH ULTIMATE TRACK.

WEDNESDAY...
A MID-LEVEL RIDGE WILL MOVE THROUGH THE REGION TUESDAY NIGHT INTO
EARLY WEDNESDAY LEADING TO A BRIEF RESPITE BETWEEN WEATHER SYSTEMS.
THEN A MID-LEVEL TROUGH IS PROJECTED TO BECOME NEGATIVELY TILTED
OVER THE OHIO VALLEY ON WED...LEADING TO A MERIDIONAL FLOW ALONG
THE EAST COAST...WITH THE ENTIRE COLUMN EXPECTED TO BE WELL ABOVE
FREEZING ACROSS THE CWA FAVORING A RAIN EVENT. THERE ARE SEVERAL
INGREDIENTS COMING TOGETHER FOR HEAVY RAIN. IN PARTICULAR...DEEP
GULF MOISTURE...LOW-LEVEL ISENTROPIC LIFT...MID-LEVEL PVA...AND
THE RIGHT-REAR QUADRANT OF A 140 KNOT UPPER-LEVEL JET JUST NORTH.
THE SYSTEM SHOULD BE FAIRLY PROGRESSIVE BUT WILL HAVE TO MONITOR
POTENTIAL FOR FLOODING.

THU AND FRI...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS
TO BUILD IN. TEMPERATURES WILL RETURN TO SEASONABLE LEVELS AND
THERE COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW.

&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
SMWHAT GUSTY NW WINDS WILL CONTINUE FOR A COUPLE MORE HOURS BUT
SHOULD DIE DOWN SOME BY SUNSET AS THE SFC COOLS/DECOUPLES AND THE
LARGER SCALE PRES GRADIENT RELAXES. LIGHT NW WINDS WILL CONTINUE
OVERNIGHT. THE EARLIER LOW CLOUDS HAVE MOSTLY DISSIPATED AND ATTM
ARE NOT EXPECTED TO RETURN TONIGHT. SOME LOW CLOUDS ARE POSSIBLE
ON SATURDAY BUT SHOULD NOT BE AS EXENSIVE AS THIS MORNING. WINDS
ON SATURDAY WILL BE LIGHT NORTHERLY AS A HIGH PRESSURE RIDGE MOVES
OVER HEAD.

OUTLOOK...
SUNDAY...VFR CONDITIONS EXPECTED.
MONDAY AND TUESDAY...IFR POSSIBLE IN SHRA AND SHSN.
WEDNESDAY...IFR POSSIBLE IN RA AND FG.

&&

.MARINE...
SUB-SCA CONDS ARE EXPECTED FOR THE NEXT 24 HOURS AT LEAST. SMWHT
GUST NW WINDS THIS EVENING WILL GRADUALLY DIMINISH TONIGHT THROUGH
SATURDAY AS A RIDGE OF HIGH PRES MOVES OVERHEAD. SEAS ARE
CURRENTLY RUNNING 2 TO 3 FT BUT THEY SHOULD GRADUALLY DIMINISH
ALSO.

OUTLOOK...

SUNDAY AND MONDAY...SUB-SCA CONDITIONS EXPECTED.
TUESDAY...SCA MAY BE NEEDED FOR BUILDING SEAS.
WEDNESDAY...GALE WARNING MAY BE NEEDED.

&&

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

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...AMC
SHORT TERM...AMC
LONG TERM...FRANCK
AVIATION...AMC/FRANCK
MARINE...AMC/FRANCK






000
FXUS61 KPHI 192051
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
351 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE JUST NORTH OF LAKE SUPERIOR WILL GRADUALLY MOVE
EASTWARD INTO NORTHERN NEW ENGLAND THRU MONDAY. A WAVE OF LOW
PRESSURE WILL FORM ALONG THE MID-ATLANTIC COASTLINE ON MONDAY
AND MOVE NORTHEASTWARD JUST OFFSHORE ON TUESDAY. MEANWHILE...
A STRONG AREA OF LOW-PRESSURE WILL FORM OVER THE MISSISSIPPI
VALLEY AND MOVE THRU THE GREAT LAKES REGION DURING THE MIDDLE
OF THE WEEK...BRINGING A STRONG COLD FRONT THRU THE REGION
BY THURSDAY. HIGH PRESSURE IS PROJECTED TO BUILD IN ON FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY/...
EXTENSIVE LOW CLOUD DECK THAT COVERED THE AREA THIS MORNING HAS
ERODED CONSIDERABLY THIS AFTN. CLOUD COVER PERSISTS OVER DELMARVA
AND OVER NWRN NJ AND ADJ PA. GIVEN THE NWLY LOW-LVL FLOW...THINK THE
CLOUDS DOWN SOUTH WILL CONT TO ERODE WHILE THE NRN AREA WILL BE MORE
PERSISTENT INTO THIS EVENING. TEMPS IN CLEARING AREAS HAVE RESPONDED
ONLY SLIGHTLY DUE TO THE LOW DEC SUN ANGLE.

FOR TONIGHT...NW WINDS WILL CONTINUE BUT WILL BECOME LIGHTER AS
CANADIAN LOW PRES MOVES AWAY AND HIGH PRES MOVES CLOSED WITH
RESULTING RELAXED PRES GRAD. MOSTLY CLEAR TO PARTLY CLOUDY SKIES
TONIGHT SHOULD ALLOW FOR DECENT COOLING WITH OVERNIGHT MINS GENLY 5
TO 10 DEGS COOLER THAN LAST NIGHT.

&&

.SHORT TERM /6 AM TO 6 PM SATURDAY/...
FOR SATURDAY...HIGH PRES CENTERED OVER CANADA SHIFTS EWD FROM
ONTARIO INTO QUEBEC. A RIDGE AXIS IS FCST TO EXTEND SWD THROUGH THE
MID-ATLANTIC REGION RESULTING IN ONLY LIGHT NLY WINDS. SOME LOW-LVL
MOISTURE SHOULD REMAIN TRAPPED BELOW THE LARGE-SCALE SUBSIDENCE
INVERSION BUT HARD TO SAY HOW EXTENSIVE ANY LOW CLOUDS MAY BE. THE
12-KM NAM SHOWS A THIN LOW CLOUD LAYER DEVELOPING DURG THE DAY BUT
HIGHER-RES ARW/NMM AND THE GFS DO NOT. THERE WILL BE SOME HIGHER
CLOUDS ALSO ASSOCD WITH THE SHRTWV NOW MOVING ENEWD OUT OF THE SRN
PLAINS...HWVR POPS REMAIN NEAR ZERO.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

* SLIGHT CHANCE OF SNOW SHOWERS SUNDAY MORNING MAINLY NORTH.
* SNOW POSSIBLE NORTHWEST OF THE I-95 CORRIDOR LATE MONDAY
  THRU EARLY TUESDAY.
* POTENTIAL FOR HEAVY RAIN INCREASING ON CHRISTMAS EVE DAY.

OVERVIEW...

MID-LEVEL BLOCKING PATTERN OVER NOAM BEGINS TO DISLODGE IN RESPONSE
JET ENERGY MOVING INTO THE PACIFIC NORTHWEST THIS WEEKEND...CARVING
OUT A DEEP TROUGH OVER THE MS VALLEY EARLY EARLY NEXT WEEK...WHICH
LEADS TO INCLEMENT WEATHER IN THE TUESDAY THRU WEDNESDAY TIME FRAME.

DETAILS...

SUNDAY...
SHORTWAVE LIFTING THROUGH THE REGION EARLY IN THE DAY MAY GENERATE
ENOUGH LIFT ALONG WITH MARGINAL MOISTURE IN THE COLUMN TO PRODUCE
SOME LIGHT SNOW SHOWERS...MAINLY DURING THE PRE-DAWN HOURS. LITTLE
IF ANY ACCUMULATION EXPECTED AS MOISTURE IS VERY LIMITED. RIDGING
THEN BUILDS IN SO FAIR WEATHER IS EXPECTED THE REMAINDER OF THE DAY.

MONDAY AND TUESDAY...
HIGH PRESSURE ANCHORS ALONG THE LEE OF THE APPALACHIANS. A SOUTHERN
STREAM SHORTWAVE WILL INDUCE LOW-PRESSURE OF THE MID-ATLANTIC COAST.
MODELS BRING QPF NORTHWARD INTO THE AREA ON MONDAY NIGHT INTO EARLY
TUESDAY. THERMAL PROFILES ARE COLD ENOUGH FOR SNOW TO THE NORTHWEST
OF THE I-95 CORRIDOR...BUT THE BEST LIFT IS FOCUSED JUST SOUTHEAST
OF THIS AREA...AND THE SYSTEM COULD TRACK FURTHER TO THE SOUTH PER
12Z UKMET MODEL. STILL A LOT OF UNCERTAINTY WITH ULTIMATE TRACK.

WEDNESDAY...
A MID-LEVEL RIDGE WILL MOVE THROUGH THE REGION TUESDAY NIGHT INTO
EARLY WEDNESDAY LEADING TO A BRIEF RESPITE BETWEEN WEATHER SYSTEMS.
THEN A MID-LEVEL TROUGH IS PROJECTED TO BECOME NEGATIVELY TILTED
OVER THE OHIO VALLEY ON WED...LEADING TO A MERIDIONAL FLOW ALONG
THE EAST COAST...WITH THE ENTIRE COLUMN EXPECTED TO BE WELL ABOVE
FREEZING ACROSS THE CWA FAVORING A RAIN EVENT. THERE ARE SEVERAL
INGREDIENTS COMING TOGETHER FOR HEAVY RAIN. IN PARTICULAR...DEEP
GULF MOISTURE...LOW-LEVEL ISENTROPIC LIFT...MID-LEVEL PVA...AND
THE RIGHT-REAR QUADRANT OF A 140 KNOT UPPER-LEVEL JET JUST NORTH.
THE SYSTEM SHOULD BE FAIRLY PROGRESSIVE BUT WILL HAVE TO MONITOR
POTENTIAL FOR FLOODING.

THU AND FRI...
LOW-PRESSURE MOVES NORTHWARD INTO QUEBEC AND HIGH-PRESSURE BEGINS
TO BUILD IN. TEMPERATURES WILL RETURN TO SEASONABLE LEVELS AND
THERE COULD BE SNOW SHOWERS IN THE BLUSTERY NORTHWEST FLOW.

&&

.AVIATION /21Z FRIDAY THROUGH WEDNESDAY/...
SMWHAT GUSTY NW WINDS WILL CONTINUE FOR A COUPLE MORE HOURS BUT
SHOULD DIE DOWN SOME BY SUNSET AS THE SFC COOLS/DECOUPLES AND THE
LARGER SCALE PRES GRADIENT RELAXES. LIGHT NW WINDS WILL CONTINUE
OVERNIGHT. THE EARLIER LOW CLOUDS HAVE MOSTLY DISSIPATED AND ATTM
ARE NOT EXPECTED TO RETURN TONIGHT. SOME LOW CLOUDS ARE POSSIBLE
ON SATURDAY BUT SHOULD NOT BE AS EXENSIVE AS THIS MORNING. WINDS
ON SATURDAY WILL BE LIGHT NORTHERLY AS A HIGH PRESSURE RIDGE MOVES
OVER HEAD.

OUTLOOK...
SUNDAY...VFR CONDITIONS EXPECTED.
MONDAY AND TUESDAY...IFR POSSIBLE IN SHRA AND SHSN.
WEDNESDAY...IFR POSSIBLE IN RA AND FG.

&&

.MARINE...
SUB-SCA CONDS ARE EXPECTED FOR THE NEXT 24 HOURS AT LEAST. SMWHT
GUST NW WINDS THIS EVENING WILL GRADUALLY DIMINISH TONIGHT THROUGH
SATURDAY AS A RIDGE OF HIGH PRES MOVES OVERHEAD. SEAS ARE
CURRENTLY RUNNING 2 TO 3 FT BUT THEY SHOULD GRADUALLY DIMINISH
ALSO.

OUTLOOK...

SUNDAY AND MONDAY...SUB-SCA CONDITIONS EXPECTED.
TUESDAY...SCA MAY BE NEEDED FOR BUILDING SEAS.
WEDNESDAY...GALE WARNING MAY BE NEEDED.

&&

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

&&

$$
SYNOPSIS...FRANCK
NEAR TERM...AMC
SHORT TERM...AMC
LONG TERM...FRANCK
AVIATION...AMC/FRANCK
MARINE...AMC/FRANCK







000
FXUS61 KPBZ 191804
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
104 PM EST FRI DEC 19 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
SCATTERED FLURRIES MAY LAST FOR JUST A FEW MORE HOURS AS WEAKENING
NORTHWEST FLOW MAY PROVIDE FOR SOME LAKE ENHANCED FLURRIES IN THE
LINGERING LOW LEVEL MOISTURE. THE UPPER TROUGH WILL DEPART EAST
AND BE REPLACED BY RIDGING TONIGHT. MODEL PROFILES SUGGEST THAT
SOME MOISTURE WILL REMAIN TRAPPED UNDER THE BUILDING UPPER
RIDGE...PREVENTING US FROM CLEARING OUT THIS EVENING. THIS ISN`T
COMPLETELY CLEAR CUT...BUT WILL OPT TO KEEP MOSTLY CLOUDY WORDING
UNLESS SATELLITE OBSERVATIONS SHOW OTHERWISE. DID DROP TEMPS FOR THE REST OF
THE AFTERNOON AS CLOUD COVER SHOULD KEEP TEMPERATURES FROM WARMING
MUCH ABOVE CURRENT VALUES. LOWS TONIGHT WERE KEPT NEAR MET
GUIDANCE.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
HIGH PRESSURE WILL REIGN OVER THE FORECAST AREA THROUGH THE
WEEKEND. A WEAK OPEN WAVE TRIES TO SKIRT THE SRN EXTENT OF THE SFC
HIGH SAT AFTERNOON...BUT MODELS CONTINUE TO TREND IT FURTHER SOUTH
WELL OUT OF OUR REGION. AFTER LARGELY ZONAL FLOW ALOFT THROUGH
SUNDAY THE UPPER LEVEL PATTERN FAVORS SWRLY FLOW ON THE BACKSIDE
OF THE SFC HIGH. THIS WILL WORK TO DRIVE WARMER TEMPS INTO THE
FORECAST AREA WITH HIGHS DRIVING ABOVE AVERAGE HEADING INTO EARLY
NEXT WEEK.
TAX

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
WHILE IN GENERAL AGREEMENT ON DEEPENING UPPER LEVEL CLOSED LOW OVER
THE GREAT LAKES TUESDAY THROUGH THURSDAY WITH PERIODS OF RAIN INTO
WEDNESDAY UNTIL COLD FRONT WILL CHANGE PRECIP OVER TO SNOW SHOWERS
LATER WEDNESDAY AND THURSDAY. WINDS WILL BE ON THE INCREASE
THURSDAY AS SURFACE LOW WRAPS UP NORTH OF THE REGION. QPF ON THE
FRONT SIDE OF SYSTEM WILL BE NEAR AN INCH...WHICH SHOULD NOT
PRODUCE ANY SIGNIFICANT PROBLEMS. BACKLASH SNOW WEDNESDAY NIGHT
INTO THURSDAY WILL BE LIGHT WITH ONLY MINOR ACCUMULATIONS
EXPECTED. FLOW BEHIND COLD FRONT LOOKS TO STAY SOUTHWESTERLY WHICH
LOOKS TO LIMIT LAKE ENHANCED AMOUNTS ALONG I-80 AND THE RIDGES.
COLDER TEMPERATURES WILL THEN MODERATE FRIDAY AS MID LEVEL FLOW
QUICKLY BECOMES ZONAL.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
ISOLATED IFR SNOW SHOWERS AND FOG WILL END BY 20Z WITH GENERAL
MVFR EXPECTED THROUGH TONIGHT.


OUTLOOK.../SATURDAY FRIDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$













000
FXUS61 KPBZ 191804
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
104 PM EST FRI DEC 19 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
SCATTERED FLURRIES MAY LAST FOR JUST A FEW MORE HOURS AS WEAKENING
NORTHWEST FLOW MAY PROVIDE FOR SOME LAKE ENHANCED FLURRIES IN THE
LINGERING LOW LEVEL MOISTURE. THE UPPER TROUGH WILL DEPART EAST
AND BE REPLACED BY RIDGING TONIGHT. MODEL PROFILES SUGGEST THAT
SOME MOISTURE WILL REMAIN TRAPPED UNDER THE BUILDING UPPER
RIDGE...PREVENTING US FROM CLEARING OUT THIS EVENING. THIS ISN`T
COMPLETELY CLEAR CUT...BUT WILL OPT TO KEEP MOSTLY CLOUDY WORDING
UNLESS SATELLITE OBSERVATIONS SHOW OTHERWISE. DID DROP TEMPS FOR THE REST OF
THE AFTERNOON AS CLOUD COVER SHOULD KEEP TEMPERATURES FROM WARMING
MUCH ABOVE CURRENT VALUES. LOWS TONIGHT WERE KEPT NEAR MET
GUIDANCE.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
HIGH PRESSURE WILL REIGN OVER THE FORECAST AREA THROUGH THE
WEEKEND. A WEAK OPEN WAVE TRIES TO SKIRT THE SRN EXTENT OF THE SFC
HIGH SAT AFTERNOON...BUT MODELS CONTINUE TO TREND IT FURTHER SOUTH
WELL OUT OF OUR REGION. AFTER LARGELY ZONAL FLOW ALOFT THROUGH
SUNDAY THE UPPER LEVEL PATTERN FAVORS SWRLY FLOW ON THE BACKSIDE
OF THE SFC HIGH. THIS WILL WORK TO DRIVE WARMER TEMPS INTO THE
FORECAST AREA WITH HIGHS DRIVING ABOVE AVERAGE HEADING INTO EARLY
NEXT WEEK.
TAX

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
WHILE IN GENERAL AGREEMENT ON DEEPENING UPPER LEVEL CLOSED LOW OVER
THE GREAT LAKES TUESDAY THROUGH THURSDAY WITH PERIODS OF RAIN INTO
WEDNESDAY UNTIL COLD FRONT WILL CHANGE PRECIP OVER TO SNOW SHOWERS
LATER WEDNESDAY AND THURSDAY. WINDS WILL BE ON THE INCREASE
THURSDAY AS SURFACE LOW WRAPS UP NORTH OF THE REGION. QPF ON THE
FRONT SIDE OF SYSTEM WILL BE NEAR AN INCH...WHICH SHOULD NOT
PRODUCE ANY SIGNIFICANT PROBLEMS. BACKLASH SNOW WEDNESDAY NIGHT
INTO THURSDAY WILL BE LIGHT WITH ONLY MINOR ACCUMULATIONS
EXPECTED. FLOW BEHIND COLD FRONT LOOKS TO STAY SOUTHWESTERLY WHICH
LOOKS TO LIMIT LAKE ENHANCED AMOUNTS ALONG I-80 AND THE RIDGES.
COLDER TEMPERATURES WILL THEN MODERATE FRIDAY AS MID LEVEL FLOW
QUICKLY BECOMES ZONAL.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
ISOLATED IFR SNOW SHOWERS AND FOG WILL END BY 20Z WITH GENERAL
MVFR EXPECTED THROUGH TONIGHT.


OUTLOOK.../SATURDAY FRIDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$













000
FXUS61 KPBZ 191804
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
104 PM EST FRI DEC 19 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
SCATTERED FLURRIES MAY LAST FOR JUST A FEW MORE HOURS AS WEAKENING
NORTHWEST FLOW MAY PROVIDE FOR SOME LAKE ENHANCED FLURRIES IN THE
LINGERING LOW LEVEL MOISTURE. THE UPPER TROUGH WILL DEPART EAST
AND BE REPLACED BY RIDGING TONIGHT. MODEL PROFILES SUGGEST THAT
SOME MOISTURE WILL REMAIN TRAPPED UNDER THE BUILDING UPPER
RIDGE...PREVENTING US FROM CLEARING OUT THIS EVENING. THIS ISN`T
COMPLETELY CLEAR CUT...BUT WILL OPT TO KEEP MOSTLY CLOUDY WORDING
UNLESS SATELLITE OBSERVATIONS SHOW OTHERWISE. DID DROP TEMPS FOR THE REST OF
THE AFTERNOON AS CLOUD COVER SHOULD KEEP TEMPERATURES FROM WARMING
MUCH ABOVE CURRENT VALUES. LOWS TONIGHT WERE KEPT NEAR MET
GUIDANCE.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
HIGH PRESSURE WILL REIGN OVER THE FORECAST AREA THROUGH THE
WEEKEND. A WEAK OPEN WAVE TRIES TO SKIRT THE SRN EXTENT OF THE SFC
HIGH SAT AFTERNOON...BUT MODELS CONTINUE TO TREND IT FURTHER SOUTH
WELL OUT OF OUR REGION. AFTER LARGELY ZONAL FLOW ALOFT THROUGH
SUNDAY THE UPPER LEVEL PATTERN FAVORS SWRLY FLOW ON THE BACKSIDE
OF THE SFC HIGH. THIS WILL WORK TO DRIVE WARMER TEMPS INTO THE
FORECAST AREA WITH HIGHS DRIVING ABOVE AVERAGE HEADING INTO EARLY
NEXT WEEK.
TAX

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
WHILE IN GENERAL AGREEMENT ON DEEPENING UPPER LEVEL CLOSED LOW OVER
THE GREAT LAKES TUESDAY THROUGH THURSDAY WITH PERIODS OF RAIN INTO
WEDNESDAY UNTIL COLD FRONT WILL CHANGE PRECIP OVER TO SNOW SHOWERS
LATER WEDNESDAY AND THURSDAY. WINDS WILL BE ON THE INCREASE
THURSDAY AS SURFACE LOW WRAPS UP NORTH OF THE REGION. QPF ON THE
FRONT SIDE OF SYSTEM WILL BE NEAR AN INCH...WHICH SHOULD NOT
PRODUCE ANY SIGNIFICANT PROBLEMS. BACKLASH SNOW WEDNESDAY NIGHT
INTO THURSDAY WILL BE LIGHT WITH ONLY MINOR ACCUMULATIONS
EXPECTED. FLOW BEHIND COLD FRONT LOOKS TO STAY SOUTHWESTERLY WHICH
LOOKS TO LIMIT LAKE ENHANCED AMOUNTS ALONG I-80 AND THE RIDGES.
COLDER TEMPERATURES WILL THEN MODERATE FRIDAY AS MID LEVEL FLOW
QUICKLY BECOMES ZONAL.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
ISOLATED IFR SNOW SHOWERS AND FOG WILL END BY 20Z WITH GENERAL
MVFR EXPECTED THROUGH TONIGHT.


OUTLOOK.../SATURDAY FRIDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$













000
FXUS61 KPBZ 191804
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
104 PM EST FRI DEC 19 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
SCATTERED FLURRIES MAY LAST FOR JUST A FEW MORE HOURS AS WEAKENING
NORTHWEST FLOW MAY PROVIDE FOR SOME LAKE ENHANCED FLURRIES IN THE
LINGERING LOW LEVEL MOISTURE. THE UPPER TROUGH WILL DEPART EAST
AND BE REPLACED BY RIDGING TONIGHT. MODEL PROFILES SUGGEST THAT
SOME MOISTURE WILL REMAIN TRAPPED UNDER THE BUILDING UPPER
RIDGE...PREVENTING US FROM CLEARING OUT THIS EVENING. THIS ISN`T
COMPLETELY CLEAR CUT...BUT WILL OPT TO KEEP MOSTLY CLOUDY WORDING
UNLESS SATELLITE OBSERVATIONS SHOW OTHERWISE. DID DROP TEMPS FOR THE REST OF
THE AFTERNOON AS CLOUD COVER SHOULD KEEP TEMPERATURES FROM WARMING
MUCH ABOVE CURRENT VALUES. LOWS TONIGHT WERE KEPT NEAR MET
GUIDANCE.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
HIGH PRESSURE WILL REIGN OVER THE FORECAST AREA THROUGH THE
WEEKEND. A WEAK OPEN WAVE TRIES TO SKIRT THE SRN EXTENT OF THE SFC
HIGH SAT AFTERNOON...BUT MODELS CONTINUE TO TREND IT FURTHER SOUTH
WELL OUT OF OUR REGION. AFTER LARGELY ZONAL FLOW ALOFT THROUGH
SUNDAY THE UPPER LEVEL PATTERN FAVORS SWRLY FLOW ON THE BACKSIDE
OF THE SFC HIGH. THIS WILL WORK TO DRIVE WARMER TEMPS INTO THE
FORECAST AREA WITH HIGHS DRIVING ABOVE AVERAGE HEADING INTO EARLY
NEXT WEEK.
TAX

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
WHILE IN GENERAL AGREEMENT ON DEEPENING UPPER LEVEL CLOSED LOW OVER
THE GREAT LAKES TUESDAY THROUGH THURSDAY WITH PERIODS OF RAIN INTO
WEDNESDAY UNTIL COLD FRONT WILL CHANGE PRECIP OVER TO SNOW SHOWERS
LATER WEDNESDAY AND THURSDAY. WINDS WILL BE ON THE INCREASE
THURSDAY AS SURFACE LOW WRAPS UP NORTH OF THE REGION. QPF ON THE
FRONT SIDE OF SYSTEM WILL BE NEAR AN INCH...WHICH SHOULD NOT
PRODUCE ANY SIGNIFICANT PROBLEMS. BACKLASH SNOW WEDNESDAY NIGHT
INTO THURSDAY WILL BE LIGHT WITH ONLY MINOR ACCUMULATIONS
EXPECTED. FLOW BEHIND COLD FRONT LOOKS TO STAY SOUTHWESTERLY WHICH
LOOKS TO LIMIT LAKE ENHANCED AMOUNTS ALONG I-80 AND THE RIDGES.
COLDER TEMPERATURES WILL THEN MODERATE FRIDAY AS MID LEVEL FLOW
QUICKLY BECOMES ZONAL.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
ISOLATED IFR SNOW SHOWERS AND FOG WILL END BY 20Z WITH GENERAL
MVFR EXPECTED THROUGH TONIGHT.


OUTLOOK.../SATURDAY FRIDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$













000
FXUS61 KLWX 191800
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
100 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVERHEAD THIS AFTERNOON...THEN PERSIST
THROUGH SUNDAY. LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC COAST
MONDAY THROUGH MONDAY NIGHT. A STRONG COLD FRONT WILL PASS THROUGH
THE AREA WEDNESDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
SURFACE HIGH PRESSURE WILL CONTINUE TO BUILD TOWARD THE REGION
FROM THE OHIO VALLEY THIS AFTERNOON. A NORTHWEST FLOW AHEAD OF
THE HIGH WILL CAUSE SEASONABLY CHILLY CONDITIONS DURING THIS TIME.

THERE WILL BE JUST ENOUGH MOISTURE UNDERNEATH THE SUBSIDENCE
INVERSION FOR A BKN STRATOCU DECK ACROSS THE NORTHERN AND CENTRAL
PORTIONS OF THE CWA. FURTHER SOUTH ACROSS CENTRAL
VIRGINIA...PLENTY OF SUNSHINE IS EXPECTED DUE TO THE DOWNSLOPING
NORTHWEST FLOW.

HIGH PRESSURE WILL BUILD OVERHEAD TONIGHT. THE STRATO CU DECK
SHOULD BREAK ACROSS MOST AREAS THIS EVENING...BUT HIGH AND MID-
LEVEL CLOUDS WILL INCREASE FROM SOUTHWEST TO NORTHEAST LATER
TONIGHT AS AN UPPER-LEVEL DISTURBANCE APPROACHES FROM THE
TENNESSEE VALLEY. MIN TEMPS WILL RANGE FROM THE LOWER 20S IN THE
MOUNTAINS TO THE LOWER AND MIDDLE 30S IN DOWNTOWN WASHINGTON AND
BALTIMORE.

THE UPPER-LEVEL DISTURBANCE WILL PASS THROUGH THE REGION SATURDAY.
THIS WILL CAUSE SURFACE LOW PRESSURE TO DEVELOP OFF THE SOUTH
CAROLINA COAST...BUT IT WILL BE TOO FAR TO OUR SOUTH FOR ANY
PRECIPITATION. HOWEVER...MOSTLY CLOUDY SKIES ARE EXPECTED AS HIGH
AND MID-LEVEL CLOUDS PASS THROUGH WITH THE UPPER-LEVEL
DISTURBANCE. SEASONABLY CHILLY CONDITIONS WILL CONTINUE BUT WINDS
WILL BE LIGHT. MAX TEMPS WILL RANGE FROM THE UPPER 20S AND LOWER
30S IN THE ALLEGHENY HIGHLANDS TO THE LOWER AND MIDDLE 40S IN
CENTRAL VIRGINIA.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
LARGE SURFACE HIGH PRESSURE WILL EXTEND FROM SOUTHEASTERN CANADA
THROUGH THE MIDDLE ATLANTIC AND INTO THE SOUTHEASTERN CONUS SATURDAY
NIGHT. A WEAK UPPER TROUGH WILL MOVE THROUGH THE AREA...RESULTING IN
A MID-LEVEL CLOUD DECK OVER THE AREA. GIVEN THE CLOUD
COVER...FAVORED THE WARMER MET GUIDANCE FOR LOW TEMPS.  IT WILL BE A
COLD NIGHT...WITH LOWS IN THE 20S OVER NEARLY ALL OF THE FORECAST
AREA. DOWNTOWN AREAS OF BALTIMORE AND WASHINGTON MAY STAY AT OR JUST
ABOVE FREEZING OVERNIGHT.

THE HIGH WILL BE DIRECTLY OVERHEAD SUNDAY...WITH MOSTLY SUNNY SKIES
AND LIGHT WINDS. SOME DISCREPANCY AMONG MODELS AS TO WHETHER THE
RIDGE AXIS WILL MAKE IT TO THE DELMARVA BY THE AFTERNOON...WHICH
WOULD RESULT IN LIGHT RETURN FLOW ACROSS THE SOUTHERN AND WESTERN
COUNTIES OF THE CWA. HIGH EXPECTED TO BE IN THE MID TO UPPER 40S
ACROSS MOST OF THE CWA...WITH LOW 40S POSSIBLE NEAR THE MASON DIXON
LINE AND IN HIGHER ELEVATIONS.

ONLY GRADUAL EWD MOVEMENT IN THE RIDGE AXIS TOWARDS THE COAST SUNDAY
NIGHT. MODELS HAVE TRENDED SLOWER IN THE DEVELOPMENT OF LOW PRESSURE
ALONG THE SOUTHEAST COAST. REMOVED ALL POPS FROM THE CWA SUNDAY
NIGHT ACCORDINGLY. LOWS WILL BE SIMILAR TO SATURDAY NIGHT...IN THE
20S FOR MOST OF THE CWA AND A FEW SPOTS ABOVE 30 IN METRO
BALTIMORE/WASHINGTON.


&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
PVA MAX IN SOUTHERN FLOW WILL SUPPORT WIDESPREAD PRECIPITATION
ACROSS REGION MONDAY. ALTHOUGH MOST OF PRECIPITATION LOOKS TO LIQUID
IT APPEARS THAT ENOUGH COLD AIR IS IN PLACE FOR PRECIPITATION BEGIN
AS A WINTRY MIX EARLY MONDAY.

STRONG COLD FRONT SUPPORTED BY UPPER LEVEL CUT-OFF SOUTH OF THE
GREAT LAKES WILL CROSS THE MID ATLANTIC STATES BY WEDNESDAY. RAIN
WILL CHANGE OVER TO SNOW IN AREA AFFECTED BY MUCH COLDER AIR
STREAMING INTO REGION BEHIND THE LOW.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
A BKN STRATOCU DECK IS EXPECTED ACROSS MOST OF THE TERMINALS
THROUGH THIS AFTERNOON. CIGS SHOULD REMAIN ABOVE 3KFT. NORTHWEST
WINDS WILL GUST AROUND 15 TO 20 KNOTS THROUGH THIS AFTERNOON
BEFORE DIMINISHING AROUND SUNSET. HIGH PRESSURE WILL BUILD OVER
THE TERMINALS TONIGHT THROUGH SATURDAY. VFR CONDITIONS WILL
CONTINUE.

HIGH PRESSURE WILL BE DIRECTLY OVERHEAD SATURDAY NIGHT THROUGH
SUNDAY NIGHT. VFR CONDITIONS EXPECTED WITH LIGHT WINDS. LOW
PRESSURE MAY BRING PRECIPITATION AND SUBVFR CONDITIONS MONDAY AND
TUESDAY. A STRONG COLD MAY IMPACT THE TERMINALS WEDNESDAY.

&&

.MARINE...
NW WINDS WILL CONTINUE TODAY AS HIGH PRESSURE APPROACHES FROM THE
WEST. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE WATERS DURING
THIS TIME. HIGH PRESSURE WILL BUILD OVER THE TONIGHT THROUGH
SATURDAY. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THIS EVENING
ACROSS THE MARYLAND CHESAPEAKE BAY FROM SANDY POINT TO SMITH POINT
AND THE LOWER TIDAL POTOMAC RIVER FROM COBB ISLAND TO SMITH POINT.

HIGH PRESSURE WILL BE DIRECTLY OVER THE WATERS SATURDAY NIGHT
THROUGH SUNDAY NIGHT. LIGHT NORTHERLY FLOW SATURDAY NIGHT AND
SUNDAY...SHIFTING TO THE E-NE SUNDAY NIGHT. LOW PRESSURE MAY
IMPACT THE WATERS MONDAY INTO TUESDAY BEFORE A STRONG COLD FRONT
PASSES THROUGH WEDNESDAY.



&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ530-
     531-535-536-538-539-542.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ532>534-
     537-540-541-543.

&&

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







000
FXUS61 KLWX 191800
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
100 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVERHEAD THIS AFTERNOON...THEN PERSIST
THROUGH SUNDAY. LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC COAST
MONDAY THROUGH MONDAY NIGHT. A STRONG COLD FRONT WILL PASS THROUGH
THE AREA WEDNESDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
SURFACE HIGH PRESSURE WILL CONTINUE TO BUILD TOWARD THE REGION
FROM THE OHIO VALLEY THIS AFTERNOON. A NORTHWEST FLOW AHEAD OF
THE HIGH WILL CAUSE SEASONABLY CHILLY CONDITIONS DURING THIS TIME.

THERE WILL BE JUST ENOUGH MOISTURE UNDERNEATH THE SUBSIDENCE
INVERSION FOR A BKN STRATOCU DECK ACROSS THE NORTHERN AND CENTRAL
PORTIONS OF THE CWA. FURTHER SOUTH ACROSS CENTRAL
VIRGINIA...PLENTY OF SUNSHINE IS EXPECTED DUE TO THE DOWNSLOPING
NORTHWEST FLOW.

HIGH PRESSURE WILL BUILD OVERHEAD TONIGHT. THE STRATO CU DECK
SHOULD BREAK ACROSS MOST AREAS THIS EVENING...BUT HIGH AND MID-
LEVEL CLOUDS WILL INCREASE FROM SOUTHWEST TO NORTHEAST LATER
TONIGHT AS AN UPPER-LEVEL DISTURBANCE APPROACHES FROM THE
TENNESSEE VALLEY. MIN TEMPS WILL RANGE FROM THE LOWER 20S IN THE
MOUNTAINS TO THE LOWER AND MIDDLE 30S IN DOWNTOWN WASHINGTON AND
BALTIMORE.

THE UPPER-LEVEL DISTURBANCE WILL PASS THROUGH THE REGION SATURDAY.
THIS WILL CAUSE SURFACE LOW PRESSURE TO DEVELOP OFF THE SOUTH
CAROLINA COAST...BUT IT WILL BE TOO FAR TO OUR SOUTH FOR ANY
PRECIPITATION. HOWEVER...MOSTLY CLOUDY SKIES ARE EXPECTED AS HIGH
AND MID-LEVEL CLOUDS PASS THROUGH WITH THE UPPER-LEVEL
DISTURBANCE. SEASONABLY CHILLY CONDITIONS WILL CONTINUE BUT WINDS
WILL BE LIGHT. MAX TEMPS WILL RANGE FROM THE UPPER 20S AND LOWER
30S IN THE ALLEGHENY HIGHLANDS TO THE LOWER AND MIDDLE 40S IN
CENTRAL VIRGINIA.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
LARGE SURFACE HIGH PRESSURE WILL EXTEND FROM SOUTHEASTERN CANADA
THROUGH THE MIDDLE ATLANTIC AND INTO THE SOUTHEASTERN CONUS SATURDAY
NIGHT. A WEAK UPPER TROUGH WILL MOVE THROUGH THE AREA...RESULTING IN
A MID-LEVEL CLOUD DECK OVER THE AREA. GIVEN THE CLOUD
COVER...FAVORED THE WARMER MET GUIDANCE FOR LOW TEMPS.  IT WILL BE A
COLD NIGHT...WITH LOWS IN THE 20S OVER NEARLY ALL OF THE FORECAST
AREA. DOWNTOWN AREAS OF BALTIMORE AND WASHINGTON MAY STAY AT OR JUST
ABOVE FREEZING OVERNIGHT.

THE HIGH WILL BE DIRECTLY OVERHEAD SUNDAY...WITH MOSTLY SUNNY SKIES
AND LIGHT WINDS. SOME DISCREPANCY AMONG MODELS AS TO WHETHER THE
RIDGE AXIS WILL MAKE IT TO THE DELMARVA BY THE AFTERNOON...WHICH
WOULD RESULT IN LIGHT RETURN FLOW ACROSS THE SOUTHERN AND WESTERN
COUNTIES OF THE CWA. HIGH EXPECTED TO BE IN THE MID TO UPPER 40S
ACROSS MOST OF THE CWA...WITH LOW 40S POSSIBLE NEAR THE MASON DIXON
LINE AND IN HIGHER ELEVATIONS.

ONLY GRADUAL EWD MOVEMENT IN THE RIDGE AXIS TOWARDS THE COAST SUNDAY
NIGHT. MODELS HAVE TRENDED SLOWER IN THE DEVELOPMENT OF LOW PRESSURE
ALONG THE SOUTHEAST COAST. REMOVED ALL POPS FROM THE CWA SUNDAY
NIGHT ACCORDINGLY. LOWS WILL BE SIMILAR TO SATURDAY NIGHT...IN THE
20S FOR MOST OF THE CWA AND A FEW SPOTS ABOVE 30 IN METRO
BALTIMORE/WASHINGTON.


&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
PVA MAX IN SOUTHERN FLOW WILL SUPPORT WIDESPREAD PRECIPITATION
ACROSS REGION MONDAY. ALTHOUGH MOST OF PRECIPITATION LOOKS TO LIQUID
IT APPEARS THAT ENOUGH COLD AIR IS IN PLACE FOR PRECIPITATION BEGIN
AS A WINTRY MIX EARLY MONDAY.

STRONG COLD FRONT SUPPORTED BY UPPER LEVEL CUT-OFF SOUTH OF THE
GREAT LAKES WILL CROSS THE MID ATLANTIC STATES BY WEDNESDAY. RAIN
WILL CHANGE OVER TO SNOW IN AREA AFFECTED BY MUCH COLDER AIR
STREAMING INTO REGION BEHIND THE LOW.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
A BKN STRATOCU DECK IS EXPECTED ACROSS MOST OF THE TERMINALS
THROUGH THIS AFTERNOON. CIGS SHOULD REMAIN ABOVE 3KFT. NORTHWEST
WINDS WILL GUST AROUND 15 TO 20 KNOTS THROUGH THIS AFTERNOON
BEFORE DIMINISHING AROUND SUNSET. HIGH PRESSURE WILL BUILD OVER
THE TERMINALS TONIGHT THROUGH SATURDAY. VFR CONDITIONS WILL
CONTINUE.

HIGH PRESSURE WILL BE DIRECTLY OVERHEAD SATURDAY NIGHT THROUGH
SUNDAY NIGHT. VFR CONDITIONS EXPECTED WITH LIGHT WINDS. LOW
PRESSURE MAY BRING PRECIPITATION AND SUBVFR CONDITIONS MONDAY AND
TUESDAY. A STRONG COLD MAY IMPACT THE TERMINALS WEDNESDAY.

&&

.MARINE...
NW WINDS WILL CONTINUE TODAY AS HIGH PRESSURE APPROACHES FROM THE
WEST. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE WATERS DURING
THIS TIME. HIGH PRESSURE WILL BUILD OVER THE TONIGHT THROUGH
SATURDAY. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THIS EVENING
ACROSS THE MARYLAND CHESAPEAKE BAY FROM SANDY POINT TO SMITH POINT
AND THE LOWER TIDAL POTOMAC RIVER FROM COBB ISLAND TO SMITH POINT.

HIGH PRESSURE WILL BE DIRECTLY OVER THE WATERS SATURDAY NIGHT
THROUGH SUNDAY NIGHT. LIGHT NORTHERLY FLOW SATURDAY NIGHT AND
SUNDAY...SHIFTING TO THE E-NE SUNDAY NIGHT. LOW PRESSURE MAY
IMPACT THE WATERS MONDAY INTO TUESDAY BEFORE A STRONG COLD FRONT
PASSES THROUGH WEDNESDAY.



&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ530-
     531-535-536-538-539-542.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ532>534-
     537-540-541-543.

&&

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







000
FXUS61 KLWX 191800
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
100 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVERHEAD THIS AFTERNOON...THEN PERSIST
THROUGH SUNDAY. LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC COAST
MONDAY THROUGH MONDAY NIGHT. A STRONG COLD FRONT WILL PASS THROUGH
THE AREA WEDNESDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
SURFACE HIGH PRESSURE WILL CONTINUE TO BUILD TOWARD THE REGION
FROM THE OHIO VALLEY THIS AFTERNOON. A NORTHWEST FLOW AHEAD OF
THE HIGH WILL CAUSE SEASONABLY CHILLY CONDITIONS DURING THIS TIME.

THERE WILL BE JUST ENOUGH MOISTURE UNDERNEATH THE SUBSIDENCE
INVERSION FOR A BKN STRATOCU DECK ACROSS THE NORTHERN AND CENTRAL
PORTIONS OF THE CWA. FURTHER SOUTH ACROSS CENTRAL
VIRGINIA...PLENTY OF SUNSHINE IS EXPECTED DUE TO THE DOWNSLOPING
NORTHWEST FLOW.

HIGH PRESSURE WILL BUILD OVERHEAD TONIGHT. THE STRATO CU DECK
SHOULD BREAK ACROSS MOST AREAS THIS EVENING...BUT HIGH AND MID-
LEVEL CLOUDS WILL INCREASE FROM SOUTHWEST TO NORTHEAST LATER
TONIGHT AS AN UPPER-LEVEL DISTURBANCE APPROACHES FROM THE
TENNESSEE VALLEY. MIN TEMPS WILL RANGE FROM THE LOWER 20S IN THE
MOUNTAINS TO THE LOWER AND MIDDLE 30S IN DOWNTOWN WASHINGTON AND
BALTIMORE.

THE UPPER-LEVEL DISTURBANCE WILL PASS THROUGH THE REGION SATURDAY.
THIS WILL CAUSE SURFACE LOW PRESSURE TO DEVELOP OFF THE SOUTH
CAROLINA COAST...BUT IT WILL BE TOO FAR TO OUR SOUTH FOR ANY
PRECIPITATION. HOWEVER...MOSTLY CLOUDY SKIES ARE EXPECTED AS HIGH
AND MID-LEVEL CLOUDS PASS THROUGH WITH THE UPPER-LEVEL
DISTURBANCE. SEASONABLY CHILLY CONDITIONS WILL CONTINUE BUT WINDS
WILL BE LIGHT. MAX TEMPS WILL RANGE FROM THE UPPER 20S AND LOWER
30S IN THE ALLEGHENY HIGHLANDS TO THE LOWER AND MIDDLE 40S IN
CENTRAL VIRGINIA.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
LARGE SURFACE HIGH PRESSURE WILL EXTEND FROM SOUTHEASTERN CANADA
THROUGH THE MIDDLE ATLANTIC AND INTO THE SOUTHEASTERN CONUS SATURDAY
NIGHT. A WEAK UPPER TROUGH WILL MOVE THROUGH THE AREA...RESULTING IN
A MID-LEVEL CLOUD DECK OVER THE AREA. GIVEN THE CLOUD
COVER...FAVORED THE WARMER MET GUIDANCE FOR LOW TEMPS.  IT WILL BE A
COLD NIGHT...WITH LOWS IN THE 20S OVER NEARLY ALL OF THE FORECAST
AREA. DOWNTOWN AREAS OF BALTIMORE AND WASHINGTON MAY STAY AT OR JUST
ABOVE FREEZING OVERNIGHT.

THE HIGH WILL BE DIRECTLY OVERHEAD SUNDAY...WITH MOSTLY SUNNY SKIES
AND LIGHT WINDS. SOME DISCREPANCY AMONG MODELS AS TO WHETHER THE
RIDGE AXIS WILL MAKE IT TO THE DELMARVA BY THE AFTERNOON...WHICH
WOULD RESULT IN LIGHT RETURN FLOW ACROSS THE SOUTHERN AND WESTERN
COUNTIES OF THE CWA. HIGH EXPECTED TO BE IN THE MID TO UPPER 40S
ACROSS MOST OF THE CWA...WITH LOW 40S POSSIBLE NEAR THE MASON DIXON
LINE AND IN HIGHER ELEVATIONS.

ONLY GRADUAL EWD MOVEMENT IN THE RIDGE AXIS TOWARDS THE COAST SUNDAY
NIGHT. MODELS HAVE TRENDED SLOWER IN THE DEVELOPMENT OF LOW PRESSURE
ALONG THE SOUTHEAST COAST. REMOVED ALL POPS FROM THE CWA SUNDAY
NIGHT ACCORDINGLY. LOWS WILL BE SIMILAR TO SATURDAY NIGHT...IN THE
20S FOR MOST OF THE CWA AND A FEW SPOTS ABOVE 30 IN METRO
BALTIMORE/WASHINGTON.


&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
PVA MAX IN SOUTHERN FLOW WILL SUPPORT WIDESPREAD PRECIPITATION
ACROSS REGION MONDAY. ALTHOUGH MOST OF PRECIPITATION LOOKS TO LIQUID
IT APPEARS THAT ENOUGH COLD AIR IS IN PLACE FOR PRECIPITATION BEGIN
AS A WINTRY MIX EARLY MONDAY.

STRONG COLD FRONT SUPPORTED BY UPPER LEVEL CUT-OFF SOUTH OF THE
GREAT LAKES WILL CROSS THE MID ATLANTIC STATES BY WEDNESDAY. RAIN
WILL CHANGE OVER TO SNOW IN AREA AFFECTED BY MUCH COLDER AIR
STREAMING INTO REGION BEHIND THE LOW.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
A BKN STRATOCU DECK IS EXPECTED ACROSS MOST OF THE TERMINALS
THROUGH THIS AFTERNOON. CIGS SHOULD REMAIN ABOVE 3KFT. NORTHWEST
WINDS WILL GUST AROUND 15 TO 20 KNOTS THROUGH THIS AFTERNOON
BEFORE DIMINISHING AROUND SUNSET. HIGH PRESSURE WILL BUILD OVER
THE TERMINALS TONIGHT THROUGH SATURDAY. VFR CONDITIONS WILL
CONTINUE.

HIGH PRESSURE WILL BE DIRECTLY OVERHEAD SATURDAY NIGHT THROUGH
SUNDAY NIGHT. VFR CONDITIONS EXPECTED WITH LIGHT WINDS. LOW
PRESSURE MAY BRING PRECIPITATION AND SUBVFR CONDITIONS MONDAY AND
TUESDAY. A STRONG COLD MAY IMPACT THE TERMINALS WEDNESDAY.

&&

.MARINE...
NW WINDS WILL CONTINUE TODAY AS HIGH PRESSURE APPROACHES FROM THE
WEST. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE WATERS DURING
THIS TIME. HIGH PRESSURE WILL BUILD OVER THE TONIGHT THROUGH
SATURDAY. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THIS EVENING
ACROSS THE MARYLAND CHESAPEAKE BAY FROM SANDY POINT TO SMITH POINT
AND THE LOWER TIDAL POTOMAC RIVER FROM COBB ISLAND TO SMITH POINT.

HIGH PRESSURE WILL BE DIRECTLY OVER THE WATERS SATURDAY NIGHT
THROUGH SUNDAY NIGHT. LIGHT NORTHERLY FLOW SATURDAY NIGHT AND
SUNDAY...SHIFTING TO THE E-NE SUNDAY NIGHT. LOW PRESSURE MAY
IMPACT THE WATERS MONDAY INTO TUESDAY BEFORE A STRONG COLD FRONT
PASSES THROUGH WEDNESDAY.



&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ530-
     531-535-536-538-539-542.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ532>534-
     537-540-541-543.

&&

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







000
FXUS61 KLWX 191800
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
100 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVERHEAD THIS AFTERNOON...THEN PERSIST
THROUGH SUNDAY. LOW PRESSURE WILL TRACK UP THE MID-ATLANTIC COAST
MONDAY THROUGH MONDAY NIGHT. A STRONG COLD FRONT WILL PASS THROUGH
THE AREA WEDNESDAY.

&&

.NEAR TERM /THROUGH SATURDAY/...
SURFACE HIGH PRESSURE WILL CONTINUE TO BUILD TOWARD THE REGION
FROM THE OHIO VALLEY THIS AFTERNOON. A NORTHWEST FLOW AHEAD OF
THE HIGH WILL CAUSE SEASONABLY CHILLY CONDITIONS DURING THIS TIME.

THERE WILL BE JUST ENOUGH MOISTURE UNDERNEATH THE SUBSIDENCE
INVERSION FOR A BKN STRATOCU DECK ACROSS THE NORTHERN AND CENTRAL
PORTIONS OF THE CWA. FURTHER SOUTH ACROSS CENTRAL
VIRGINIA...PLENTY OF SUNSHINE IS EXPECTED DUE TO THE DOWNSLOPING
NORTHWEST FLOW.

HIGH PRESSURE WILL BUILD OVERHEAD TONIGHT. THE STRATO CU DECK
SHOULD BREAK ACROSS MOST AREAS THIS EVENING...BUT HIGH AND MID-
LEVEL CLOUDS WILL INCREASE FROM SOUTHWEST TO NORTHEAST LATER
TONIGHT AS AN UPPER-LEVEL DISTURBANCE APPROACHES FROM THE
TENNESSEE VALLEY. MIN TEMPS WILL RANGE FROM THE LOWER 20S IN THE
MOUNTAINS TO THE LOWER AND MIDDLE 30S IN DOWNTOWN WASHINGTON AND
BALTIMORE.

THE UPPER-LEVEL DISTURBANCE WILL PASS THROUGH THE REGION SATURDAY.
THIS WILL CAUSE SURFACE LOW PRESSURE TO DEVELOP OFF THE SOUTH
CAROLINA COAST...BUT IT WILL BE TOO FAR TO OUR SOUTH FOR ANY
PRECIPITATION. HOWEVER...MOSTLY CLOUDY SKIES ARE EXPECTED AS HIGH
AND MID-LEVEL CLOUDS PASS THROUGH WITH THE UPPER-LEVEL
DISTURBANCE. SEASONABLY CHILLY CONDITIONS WILL CONTINUE BUT WINDS
WILL BE LIGHT. MAX TEMPS WILL RANGE FROM THE UPPER 20S AND LOWER
30S IN THE ALLEGHENY HIGHLANDS TO THE LOWER AND MIDDLE 40S IN
CENTRAL VIRGINIA.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
LARGE SURFACE HIGH PRESSURE WILL EXTEND FROM SOUTHEASTERN CANADA
THROUGH THE MIDDLE ATLANTIC AND INTO THE SOUTHEASTERN CONUS SATURDAY
NIGHT. A WEAK UPPER TROUGH WILL MOVE THROUGH THE AREA...RESULTING IN
A MID-LEVEL CLOUD DECK OVER THE AREA. GIVEN THE CLOUD
COVER...FAVORED THE WARMER MET GUIDANCE FOR LOW TEMPS.  IT WILL BE A
COLD NIGHT...WITH LOWS IN THE 20S OVER NEARLY ALL OF THE FORECAST
AREA. DOWNTOWN AREAS OF BALTIMORE AND WASHINGTON MAY STAY AT OR JUST
ABOVE FREEZING OVERNIGHT.

THE HIGH WILL BE DIRECTLY OVERHEAD SUNDAY...WITH MOSTLY SUNNY SKIES
AND LIGHT WINDS. SOME DISCREPANCY AMONG MODELS AS TO WHETHER THE
RIDGE AXIS WILL MAKE IT TO THE DELMARVA BY THE AFTERNOON...WHICH
WOULD RESULT IN LIGHT RETURN FLOW ACROSS THE SOUTHERN AND WESTERN
COUNTIES OF THE CWA. HIGH EXPECTED TO BE IN THE MID TO UPPER 40S
ACROSS MOST OF THE CWA...WITH LOW 40S POSSIBLE NEAR THE MASON DIXON
LINE AND IN HIGHER ELEVATIONS.

ONLY GRADUAL EWD MOVEMENT IN THE RIDGE AXIS TOWARDS THE COAST SUNDAY
NIGHT. MODELS HAVE TRENDED SLOWER IN THE DEVELOPMENT OF LOW PRESSURE
ALONG THE SOUTHEAST COAST. REMOVED ALL POPS FROM THE CWA SUNDAY
NIGHT ACCORDINGLY. LOWS WILL BE SIMILAR TO SATURDAY NIGHT...IN THE
20S FOR MOST OF THE CWA AND A FEW SPOTS ABOVE 30 IN METRO
BALTIMORE/WASHINGTON.


&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
PVA MAX IN SOUTHERN FLOW WILL SUPPORT WIDESPREAD PRECIPITATION
ACROSS REGION MONDAY. ALTHOUGH MOST OF PRECIPITATION LOOKS TO LIQUID
IT APPEARS THAT ENOUGH COLD AIR IS IN PLACE FOR PRECIPITATION BEGIN
AS A WINTRY MIX EARLY MONDAY.

STRONG COLD FRONT SUPPORTED BY UPPER LEVEL CUT-OFF SOUTH OF THE
GREAT LAKES WILL CROSS THE MID ATLANTIC STATES BY WEDNESDAY. RAIN
WILL CHANGE OVER TO SNOW IN AREA AFFECTED BY MUCH COLDER AIR
STREAMING INTO REGION BEHIND THE LOW.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
A BKN STRATOCU DECK IS EXPECTED ACROSS MOST OF THE TERMINALS
THROUGH THIS AFTERNOON. CIGS SHOULD REMAIN ABOVE 3KFT. NORTHWEST
WINDS WILL GUST AROUND 15 TO 20 KNOTS THROUGH THIS AFTERNOON
BEFORE DIMINISHING AROUND SUNSET. HIGH PRESSURE WILL BUILD OVER
THE TERMINALS TONIGHT THROUGH SATURDAY. VFR CONDITIONS WILL
CONTINUE.

HIGH PRESSURE WILL BE DIRECTLY OVERHEAD SATURDAY NIGHT THROUGH
SUNDAY NIGHT. VFR CONDITIONS EXPECTED WITH LIGHT WINDS. LOW
PRESSURE MAY BRING PRECIPITATION AND SUBVFR CONDITIONS MONDAY AND
TUESDAY. A STRONG COLD MAY IMPACT THE TERMINALS WEDNESDAY.

&&

.MARINE...
NW WINDS WILL CONTINUE TODAY AS HIGH PRESSURE APPROACHES FROM THE
WEST. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE WATERS DURING
THIS TIME. HIGH PRESSURE WILL BUILD OVER THE TONIGHT THROUGH
SATURDAY. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THIS EVENING
ACROSS THE MARYLAND CHESAPEAKE BAY FROM SANDY POINT TO SMITH POINT
AND THE LOWER TIDAL POTOMAC RIVER FROM COBB ISLAND TO SMITH POINT.

HIGH PRESSURE WILL BE DIRECTLY OVER THE WATERS SATURDAY NIGHT
THROUGH SUNDAY NIGHT. LIGHT NORTHERLY FLOW SATURDAY NIGHT AND
SUNDAY...SHIFTING TO THE E-NE SUNDAY NIGHT. LOW PRESSURE MAY
IMPACT THE WATERS MONDAY INTO TUESDAY BEFORE A STRONG COLD FRONT
PASSES THROUGH WEDNESDAY.



&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ530-
     531-535-536-538-539-542.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ532>534-
     537-540-541-543.

&&

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







000
FXUS61 KAKQ 191749
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1249 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTHWEST TODAY INTO
TONIGHT. WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO
EASTWARD AND OFF THE SOUTHEAST COAST LATE TONIGHT THROUGH SATURDAY
NIGHT. 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 COAST LATE SUNDAY NIGHT THROUGH MONDAY
NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
LATEST SFC ANALYSIS DEPICTS ~993 MB LO PRES OVER THE CANADIAN
MARITIMES WITH BROAD ~1027 MB HI PRES CENTERED OVER THE MIDWEST
AND INTO THE MID ATLC/SE STATES. GENLY CLEAR SKIES OVER THE AKQ
FORECAST AREA THIS MORNING...BUT BKN/OVC CONDITIONS PERSIST OVER
NORTHERN VA AND SOME OF THIS HAS ROTATED SE AND WILL AFFECT THE
NORTHERN NECK/ERN SHORE THROUGH EARLY AFTN. AS THE HIGH SPREADS E
THIS AFTN SHOULD SEE THE CLOUDS ACRS THE NE ERODE. MAIN UPDATE WAS
TO INCREASE CLOUD COVER OVER THE NE THROUGH 18Z (MOSTLY CLOUDY)...WHILE
REMAINDER OF THE CWA WILL BE SUNNY TO MOSTLY SUNNY. MIXING AREA
SOUNDINGS TO AROUND 925 MB SUPPORTS HIGHS RANGING FROM THE UPPER
40S/AROUND 50 F OVER INTERIOR NE NC AND SOUTH CENTRAL VA...TO THE
LOWER TO MID 40S ON THE ERN SHORE.

DRY WX CONTINUES TNGT WITH A MID-LEVEL S/W TROF APPROACHING THE
AREA. THE MID ATLANTIC REMAINS INFLUENCED BY SFC HI PRES CENTERED
OVER THE OH VALLEY. EXPECT LIGHT NW WINDS...A PARTLY CLOUDY SKY...AND
LO TEMPS MAINLY IN THE UPR 20S TO LWR 30S (TEMPS EXPECTED TO FALL
RAPIDLY AND THEN BECOME NEARLY STEADY LATE IN THE EVENING AS CLOUDS
SLOWLY INCREASE).

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
WEEKEND FORECAST CONTINUES TO TREND DRIER. SFC LO PRES SLIDES E
FM THE GOM SAT...WITH JUST A WEAK SFC REFLECTION OF THE LO SHOWING
OFF THE SE CST SAT NGT. 00Z GUIDANCE KEEPS THE NRN ADVANCEMENT OF
PCPN SAT NEAR THE NC/VA BORDER ON AVG. HAVE CAPPED POPS AT
20-30%...AND ONLY S OF I-64. COULD BE SOME SN/PL MIXED IN OVR THE
SRN PIEDMONT BUT PRIMARILY EXPECTING RA. ANY PCPN ENDS EVERYWHERE
BY LATE SAT AFTN. DRY CONDS THEN FOR SAT NGT AND SUN AS HI PRES
CENTERED OVR THE NE STATES STRETCHES DOWN INTO THE MID ATLANTIC.
TEMPS OVR THE WEEKEND WILL BE BLO NORMAL...WITH HIGHS MAINLY IN
THE 40S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
FORECAST UPDATED TO RAISE POPS THRU THE PERIOD (E.G. 60% MON AND
TUE NGT/WED) AS CONFIDENCE FOR PCPN AS INCREASED.

PREVIOUS DISCUSSION...
LOW PRESSURE IS EXPECTED TO DEVELOP OFF OFF THE SOUTHEAST COAST AND
TRACK NE OFF THE MID ATLANTIC COAST MONDAY INTO MONDAY NIGHT. TIMING
DIFFERENCES CONTINUE AMONGST 18/12Z NUMERICAL GUIDANCE...AND GIVEN
THIS POPS WILL REMAIN CAPPED IN THE CHC CATEGORY. POPS INCREASE TO
20-30% SUNDAY NIGHT...WITH 40-50% POPS ACROSS THE AREA MONDAY AND
MONDAY NIGHT. PCPN TYPE SHOULD GENERALLY BE RAIN...ALTHOUGH THERE
COULD BE A BRIEF PERIOD OF SLEET AT THE ONSET OVER THE NW PIEDMONT
LATE SUNDAY NIGHT AND EARLY MONDAY MORNING. HIGHS MONDAY SHOULD
RANGE FROM THE LOW 40S NW...TO MID 50S SE...AFTER MORNING LOWS IN
THE LOW 30S NW...TO AROUND 40 SE. MID-LEVEL RIDGING BRIEFLY BUILDS
INTO THE REGION TUESDAY (BRINGING MILDER CONDITIONS WITH HIGHS IN
THE LOW 50S NW TO NEAR 60 SE)...BEFORE LOW PRESSURE AND A STRONG
COLD FRONT IMPACT THE REGION TUESDAY NIGHT INTO WEDNESDAY. SPATIAL
AND TIMING DIFFERENCES CONTINUE WITH THE 18/12Z GFS TRACKING THE
SURFACE LOW W OF THE MOUNTAINS...AND THE 18/12Z ECMWF TRACKING THE
SURFACE LOW UP THE COASTAL PLAIN. THIS WILL HAVE IMPACT ON
TEMPERATURES AND WHETHER THE RAIN IS MORE STRATIFORM OR SHOWERY. IF
THE FARTHER W 18/12Z GFS WERE TO VERIFY THERE COULD BE A POTENTIAL
FOR THUNDER. HOWEVER...EVEN WITH THIS SOLUTION...SURFACE DEWPOINTS
AOA 60F REMAIN OFFSHORE. DRY AND BREEZY CONDITIONS WILL LIKELY
PREVAIL BY CHRISTMAS DAY.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THERE IS A VERY DISTINCT BOUNDARY BTWN BKN-OVC STRATOCUMULUS
(AROUND 3500 FT AGL) OVER NRN VA AND THE MD/VA LOWER EASTERN
SHORE VERSUS THE REST OF THE REGION...WHERE AN AREA OF SUBSIDENCE
PASSING FROM WEST TO EAST IS KEEPING SKIES CLEAR. IN ADDITION...NW
WINDS ARE GUSTING TO 15-20 KT WITHIN AND JUST SOUTH OF THE STRATUS
DECK. THE GUSTY WINDS WILL CALM DOWN BY SUNSET BUT THE STRATUS
WILL REMAIN STEADFAST THROUGH TONIGHT INTO SATURDAY MORNING. WINDS
AT KORF TURN MORE TO THE NORTH OVERNIGHT AND A STRATUS DECK AROUND
2000 FT AGL COULD DEVELOP OFF THE BAY. OTHERWISE...HIGH CLOUDS
WILL INCREASE ACROSS THE REGION FROM THE SW AFTER 20/0700Z TONIGHT.

LOW PRESSURE TRACKS WELL SOUTH OF THE AREA SAT/SAT NIGHT WITH
CLOUDS THICKENING AND LOWERING AS SATURDAY PROGRESSES. STEADY
PRECIPITATION WILL BE SHUNTED WELL SOUTH OF THE AREA...HOWEVER
THERE IS A SLIGHT CHANCE FOR RAIN SHOWERS ALONG AND SOUTH OF THE
VA/NC BORDER FROM LATE MORNING THROUGH THE AFTN. PRECIP COMES TO
AN END 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...
SURGE BEHIND DEPARTING S/W SHUD REMAIN BLO SCA LVLS THIS MORNING
ALTHOUGH A GUST OR TWO TO 20 KTS ACROSS THE BAY NOT OUT OF THE QSTN
THRU NOON. HIGH PRESSURE THEN BUILDS INTO THE AREA THROUGH
SATURDAY KEEPING A NRLY FLOW GOING AOB 15 KTS.

LOW PRESSURE DEVELOPS OFF THE SE COAST SUNDAY NIGHT...THEN TRACKS NE
OFF THE MID ATLANTIC COAST MON & MON NIGHT. THERE IS LITTLE TO NO
CAA IN THE WAKE OF THIS LOW...SO CONDITIONS SHOULD REMAIN SUB-SCA
WITH A WIND BECOMING WESTERLY BY TUE. A STRONGER LOW TRACKS W OF THE
MOUNTAINS TUES NIGHT...WITH A STRONG COLD FRONT CROSSING THE MID
ATLANTIC COAST WED MORNING.

&&

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

&&

$$
SYNOPSIS...MAS/TMG
NEAR TERM...LKB/MAS
SHORT TERM...MAS
LONG TERM...AJZ/MAS
AVIATION...BMD/MPR
MARINE...MPR








000
FXUS61 KAKQ 191749
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1249 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE BUILDS INTO THE AREA FROM THE NORTHWEST TODAY INTO
TONIGHT. WEAK LOW PRESSURE WILL TRACK FROM THE GULF OF MEXICO
EASTWARD AND OFF THE SOUTHEAST COAST LATE TONIGHT THROUGH SATURDAY
NIGHT. 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 COAST LATE SUNDAY NIGHT THROUGH MONDAY
NIGHT.

&&

.NEAR TERM /THROUGH TONIGHT/...
LATEST SFC ANALYSIS DEPICTS ~993 MB LO PRES OVER THE CANADIAN
MARITIMES WITH BROAD ~1027 MB HI PRES CENTERED OVER THE MIDWEST
AND INTO THE MID ATLC/SE STATES. GENLY CLEAR SKIES OVER THE AKQ
FORECAST AREA THIS MORNING...BUT BKN/OVC CONDITIONS PERSIST OVER
NORTHERN VA AND SOME OF THIS HAS ROTATED SE AND WILL AFFECT THE
NORTHERN NECK/ERN SHORE THROUGH EARLY AFTN. AS THE HIGH SPREADS E
THIS AFTN SHOULD SEE THE CLOUDS ACRS THE NE ERODE. MAIN UPDATE WAS
TO INCREASE CLOUD COVER OVER THE NE THROUGH 18Z (MOSTLY CLOUDY)...WHILE
REMAINDER OF THE CWA WILL BE SUNNY TO MOSTLY SUNNY. MIXING AREA
SOUNDINGS TO AROUND 925 MB SUPPORTS HIGHS RANGING FROM THE UPPER
40S/AROUND 50 F OVER INTERIOR NE NC AND SOUTH CENTRAL VA...TO THE
LOWER TO MID 40S ON THE ERN SHORE.

DRY WX CONTINUES TNGT WITH A MID-LEVEL S/W TROF APPROACHING THE
AREA. THE MID ATLANTIC REMAINS INFLUENCED BY SFC HI PRES CENTERED
OVER THE OH VALLEY. EXPECT LIGHT NW WINDS...A PARTLY CLOUDY SKY...AND
LO TEMPS MAINLY IN THE UPR 20S TO LWR 30S (TEMPS EXPECTED TO FALL
RAPIDLY AND THEN BECOME NEARLY STEADY LATE IN THE EVENING AS CLOUDS
SLOWLY INCREASE).

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY/...
WEEKEND FORECAST CONTINUES TO TREND DRIER. SFC LO PRES SLIDES E
FM THE GOM SAT...WITH JUST A WEAK SFC REFLECTION OF THE LO SHOWING
OFF THE SE CST SAT NGT. 00Z GUIDANCE KEEPS THE NRN ADVANCEMENT OF
PCPN SAT NEAR THE NC/VA BORDER ON AVG. HAVE CAPPED POPS AT
20-30%...AND ONLY S OF I-64. COULD BE SOME SN/PL MIXED IN OVR THE
SRN PIEDMONT BUT PRIMARILY EXPECTING RA. ANY PCPN ENDS EVERYWHERE
BY LATE SAT AFTN. DRY CONDS THEN FOR SAT NGT AND SUN AS HI PRES
CENTERED OVR THE NE STATES STRETCHES DOWN INTO THE MID ATLANTIC.
TEMPS OVR THE WEEKEND WILL BE BLO NORMAL...WITH HIGHS MAINLY IN
THE 40S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
FORECAST UPDATED TO RAISE POPS THRU THE PERIOD (E.G. 60% MON AND
TUE NGT/WED) AS CONFIDENCE FOR PCPN AS INCREASED.

PREVIOUS DISCUSSION...
LOW PRESSURE IS EXPECTED TO DEVELOP OFF OFF THE SOUTHEAST COAST AND
TRACK NE OFF THE MID ATLANTIC COAST MONDAY INTO MONDAY NIGHT. TIMING
DIFFERENCES CONTINUE AMONGST 18/12Z NUMERICAL GUIDANCE...AND GIVEN
THIS POPS WILL REMAIN CAPPED IN THE CHC CATEGORY. POPS INCREASE TO
20-30% SUNDAY NIGHT...WITH 40-50% POPS ACROSS THE AREA MONDAY AND
MONDAY NIGHT. PCPN TYPE SHOULD GENERALLY BE RAIN...ALTHOUGH THERE
COULD BE A BRIEF PERIOD OF SLEET AT THE ONSET OVER THE NW PIEDMONT
LATE SUNDAY NIGHT AND EARLY MONDAY MORNING. HIGHS MONDAY SHOULD
RANGE FROM THE LOW 40S NW...TO MID 50S SE...AFTER MORNING LOWS IN
THE LOW 30S NW...TO AROUND 40 SE. MID-LEVEL RIDGING BRIEFLY BUILDS
INTO THE REGION TUESDAY (BRINGING MILDER CONDITIONS WITH HIGHS IN
THE LOW 50S NW TO NEAR 60 SE)...BEFORE LOW PRESSURE AND A STRONG
COLD FRONT IMPACT THE REGION TUESDAY NIGHT INTO WEDNESDAY. SPATIAL
AND TIMING DIFFERENCES CONTINUE WITH THE 18/12Z GFS TRACKING THE
SURFACE LOW W OF THE MOUNTAINS...AND THE 18/12Z ECMWF TRACKING THE
SURFACE LOW UP THE COASTAL PLAIN. THIS WILL HAVE IMPACT ON
TEMPERATURES AND WHETHER THE RAIN IS MORE STRATIFORM OR SHOWERY. IF
THE FARTHER W 18/12Z GFS WERE TO VERIFY THERE COULD BE A POTENTIAL
FOR THUNDER. HOWEVER...EVEN WITH THIS SOLUTION...SURFACE DEWPOINTS
AOA 60F REMAIN OFFSHORE. DRY AND BREEZY CONDITIONS WILL LIKELY
PREVAIL BY CHRISTMAS DAY.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
THERE IS A VERY DISTINCT BOUNDARY BTWN BKN-OVC STRATOCUMULUS
(AROUND 3500 FT AGL) OVER NRN VA AND THE MD/VA LOWER EASTERN
SHORE VERSUS THE REST OF THE REGION...WHERE AN AREA OF SUBSIDENCE
PASSING FROM WEST TO EAST IS KEEPING SKIES CLEAR. IN ADDITION...NW
WINDS ARE GUSTING TO 15-20 KT WITHIN AND JUST SOUTH OF THE STRATUS
DECK. THE GUSTY WINDS WILL CALM DOWN BY SUNSET BUT THE STRATUS
WILL REMAIN STEADFAST THROUGH TONIGHT INTO SATURDAY MORNING. WINDS
AT KORF TURN MORE TO THE NORTH OVERNIGHT AND A STRATUS DECK AROUND
2000 FT AGL COULD DEVELOP OFF THE BAY. OTHERWISE...HIGH CLOUDS
WILL INCREASE ACROSS THE REGION FROM THE SW AFTER 20/0700Z TONIGHT.

LOW PRESSURE TRACKS WELL SOUTH OF THE AREA SAT/SAT NIGHT WITH
CLOUDS THICKENING AND LOWERING AS SATURDAY PROGRESSES. STEADY
PRECIPITATION WILL BE SHUNTED WELL SOUTH OF THE AREA...HOWEVER
THERE IS A SLIGHT CHANCE FOR RAIN SHOWERS ALONG AND SOUTH OF THE
VA/NC BORDER FROM LATE MORNING THROUGH THE AFTN. PRECIP COMES TO
AN END 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...
SURGE BEHIND DEPARTING S/W SHUD REMAIN BLO SCA LVLS THIS MORNING
ALTHOUGH A GUST OR TWO TO 20 KTS ACROSS THE BAY NOT OUT OF THE QSTN
THRU NOON. HIGH PRESSURE THEN BUILDS INTO THE AREA THROUGH
SATURDAY KEEPING A NRLY FLOW GOING AOB 15 KTS.

LOW PRESSURE DEVELOPS OFF THE SE COAST SUNDAY NIGHT...THEN TRACKS NE
OFF THE MID ATLANTIC COAST MON & MON NIGHT. THERE IS LITTLE TO NO
CAA IN THE WAKE OF THIS LOW...SO CONDITIONS SHOULD REMAIN SUB-SCA
WITH A WIND BECOMING WESTERLY BY TUE. A STRONGER LOW TRACKS W OF THE
MOUNTAINS TUES NIGHT...WITH A STRONG COLD FRONT CROSSING THE MID
ATLANTIC COAST WED MORNING.

&&

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

&&

$$
SYNOPSIS...MAS/TMG
NEAR TERM...LKB/MAS
SHORT TERM...MAS
LONG TERM...AJZ/MAS
AVIATION...BMD/MPR
MARINE...MPR









000
FXUS61 KPBZ 191720
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1220 PM EST FRI DEC 19 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH
CLOUDS WILL REMAIN.

&&

.NEAR TERM /THROUGH TONIGHT/...
FINE LINE ON RADAR IS THE BACK EDGE OF FREEZING DRIZZLE AND
FLURRIES WITH SURFACE TROUGH AND BACK EDGE OF STRETCHED VORT
BEHIND SHORTWAVE EXITING EAST. ALLOWED ADVISORIES TO EXPIRE AS
RADAR TRENDS AND SURFACE OBS SHOW DIMINISHING TREND TO PRECIP AND
HAVE ISSUED SPS TO COVER REMAINING PATCHY PRECIP. FORECAST
SOUNDINGS SHOW CLOUDS MAY HOLD IN THROUGH TONIGHT SO HAVE ADJUSTED
SKY GRIDS UP. NO CHANGE TO PREVIOUS TEMPERATURE.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
HIGH PRESSURE WILL REIGN OVER THE FORECAST AREA THROUGH THE
WEEKEND. A WEAK OPEN WAVE TRIES TO SKIRT THE SRN EXTENT OF THE SFC
HIGH SAT AFTERNOON...BUT MODELS CONTINUE TO TREND IT FURTHER SOUTH
WELL OUT OF OUR REGION. AFTER LARGELY ZONAL FLOW ALOFT THROUGH
SUNDAY THE UPPER LEVEL PATTERN FAVORS SWRLY FLOW ON THE BACKSIDE
OF THE SFC HIGH. THIS WILL WORK TO DRIVE WARMER TEMPS INTO THE
FORECAST AREA WITH HIGHS DRIVING ABOVE AVERAGE HEADING INTO EARLY
NEXT WEEK.
TAX

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
WHILE IN GENERAL AGREEMENT ON DEEPENING UPPER LEVEL CLOSED LOW OVER
THE GREAT LAKES TUESDAY THROUGH THURSDAY WITH PERIODS OF RAIN INTO
WEDNESDAY UNTIL COLD FRONT WILL CHANGE PRECIP OVER TO SNOW SHOWERS
LATER WEDNESDAY AND THURSDAY. WINDS WILL BE ON THE INCREASE
THURSDAY AS SURFACE LOW WRAPS UP NORTH OF THE REGION. QPF ON THE
FRONT SIDE OF SYSTEM WILL BE NEAR AN INCH...WHICH SHOULD NOT
PRODUCE ANY SIGNIFICANT PROBLEMS. BACKLASH SNOW WEDNESDAY NIGHT
INTO THURSDAY WILL BE LIGHT WITH ONLY MINOR ACCUMULATIONS
EXPECTED. FLOW BEHIND COLD FRONT LOOKS TO STAY SOUTHWESTERLY WHICH
LOOKS TO LIMIT LAKE ENHANCED AMOUNTS ALONG I-80 AND THE RIDGES.
COLDER TEMPERATURES WILL THEN MODERATE FRIDAY AS MID LEVEL FLOW
QUICKLY BECOMES ZONAL.

&&

.AVIATION /17Z FRIDAY THROUGH WEDNESDAY/...
ISOLATED IFR SNOW SHOWERS AND FOG WILL END BY 20Z WITH GENERAL
MVFR EXPECTED THROUGH TONIGHT.


OUTLOOK.../SATURDAY FRIDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$








000
FXUS61 KPBZ 191720
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1220 PM EST FRI DEC 19 2014

.SYNOPSIS...
BUILDING HIGH PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH
CLOUDS WILL REMAIN.

&&

.NEAR TERM /THROUGH TONIGHT/...
FINE LINE ON RADAR IS THE BACK EDGE OF FREEZING DRIZZLE AND
FLURRIES WITH SURFACE TROUGH AND BACK EDGE OF STRETCHED VORT
BEHIND SHORTWAVE EXITING EAST. ALLOWED ADVISORIES TO EXPIRE AS
RADAR TRENDS AND SURFACE OBS SHOW DIMINISHING TREND TO PRECIP AND
HAVE ISSUED SPS TO COVER REMAINING PATCHY PRECIP. FORECAST
SOUNDINGS SHOW CLOUDS MAY HOLD IN THROUGH TONIGHT SO HAVE ADJUSTED
SKY GRIDS UP. NO CHANGE TO PREVIOUS TEMPERATURE.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
HIGH PRESSURE WILL REIGN OVER THE FORECAST AREA THROUGH THE
WEEKEND. A WEAK OPEN WAVE TRIES TO SKIRT THE SRN EXTENT OF THE SFC
HIGH SAT AFTERNOON...BUT MODELS CONTINUE TO TREND IT FURTHER SOUTH
WELL OUT OF OUR REGION. AFTER LARGELY ZONAL FLOW ALOFT THROUGH
SUNDAY THE UPPER LEVEL PATTERN FAVORS SWRLY FLOW ON THE BACKSIDE
OF THE SFC HIGH. THIS WILL WORK TO DRIVE WARMER TEMPS INTO THE
FORECAST AREA WITH HIGHS DRIVING ABOVE AVERAGE HEADING INTO EARLY
NEXT WEEK.
TAX

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
WHILE IN GENERAL AGREEMENT ON DEEPENING UPPER LEVEL CLOSED LOW OVER
THE GREAT LAKES TUESDAY THROUGH THURSDAY WITH PERIODS OF RAIN INTO
WEDNESDAY UNTIL COLD FRONT WILL CHANGE PRECIP OVER TO SNOW SHOWERS
LATER WEDNESDAY AND THURSDAY. WINDS WILL BE ON THE INCREASE
THURSDAY AS SURFACE LOW WRAPS UP NORTH OF THE REGION. QPF ON THE
FRONT SIDE OF SYSTEM WILL BE NEAR AN INCH...WHICH SHOULD NOT
PRODUCE ANY SIGNIFICANT PROBLEMS. BACKLASH SNOW WEDNESDAY NIGHT
INTO THURSDAY WILL BE LIGHT WITH ONLY MINOR ACCUMULATIONS
EXPECTED. FLOW BEHIND COLD FRONT LOOKS TO STAY SOUTHWESTERLY WHICH
LOOKS TO LIMIT LAKE ENHANCED AMOUNTS ALONG I-80 AND THE RIDGES.
COLDER TEMPERATURES WILL THEN MODERATE FRIDAY AS MID LEVEL FLOW
QUICKLY BECOMES ZONAL.

&&

.AVIATION /17Z FRIDAY THROUGH WEDNESDAY/...
ISOLATED IFR SNOW SHOWERS AND FOG WILL END BY 20Z WITH GENERAL
MVFR EXPECTED THROUGH TONIGHT.


OUTLOOK.../SATURDAY FRIDAY NIGHT THROUGH WEDNESDAY/...
STRATUS AND RESTRICTIONS MAY PERSIST INTO THE WEEKEND. NEXT STORM
SYSTEM WILL BRING RESTRICTIONS TUESDAY AND WEDNESDAY.

&&

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

&&

$$









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