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000
FXUS61 KCTP 222049
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
349 PM EST MON DEC 22 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL BRING LIGHT RAIN AND FREEZING RAIN
TO CENTRAL AND EASTERN PA TONIGHT AS IT LIFTS UP THE MID ATLANTIC
COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF PENNSYLVANIA
WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH THE STATE. ANOTHER
LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE REGION BY NEXT
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
MOISTURE SLOWLY INCREASING ACROSS THE LAUREL HIGHLANDS...CENTRAL
MOUNTAINS AND LOWER SUSQ AT MID AFTERNOON. PRECIP HAS BROKEN OUT
OVER THE SOUTH CENTRAL MOUNTAINS WHERE SFC TEMPS ARE HOVERING
AROUND 32F AND SFC TD IS IN THE MID 20S. FZRA ADVISORY IN PLACE
THROUGH 05Z TONIGHT FOR LIGHT AMOUNTS OF ICE. LOWER SUSQ SHOULD
REMAIN ALL RAIN...BUT WESTERN PORTIONS OF YORK COUNTY IN THE
HIGHER TERRAIN IS ALSO EXPECTED TO SEE SOME ICE.

HI RES MODELS INDICATE A PROLONGED PERIOD OF FREEZING AND EVEN
SOME FROZEN (IP) HYDROMETEORS AS THE LIGHT SHIELD OF PRECIP LIFTS
NORTHWARD TONIGHT. BLEND OF TRENDS AND HI RES MODELS KEEP AREAS OF
FZDZ AND LCL SLEET OVER THE WESTERN...CENTRAL AND EVENTUALLY INTO
THE NORTH CENTRAL MOUNTAINS LATE TONIGHT. ADVISORIES MAY BE NEEDED
FOR THOSE NORTHERN AREAS LATER ON...BUT PRECIP MAY REMAIN FROZEN
(SLEET/SNOW MIXTURE THERE) SO HELD OFF FOR NOW.

EXPECT THE SOUTHERN TIER TO WARM SUFFICIENTLY TO CHANGE TO RAIN BY
OR AFTER 05Z. IT WILL TAKE MUCH LONGER FROM THE WEST CENTRAL
MOUNTAINS NORTHWARD. MINS WILL RANGE FROM THE UPPER 20S NORTH TO
THE LOWER 30S SOUTH.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
LOOKING AT MAINLY A CLOUDY DAY ON TUE...WITH SOME PATCHY
LIGHT RAIN. TEMPERATURES WILL BE ABOVE NORMAL...BUT MAINLY
IN THE 40S...AS THE MAIN LOW IS TOO FAR WEST FOR CENTRAL
PA TO BE IN MUCH OF A SOUTHERLY GRADIENT.

BETTER CHANCE OF RAIN LATER TUESDAY NIGHT INTO WED...AS
COLD FRONT MOVES TO THE EAST.

TEMPERATURES WILL CLIMB INTO THE 50S ON WED...AS STRONGER
SOUTHERLY WINDS DEVELOP.

WENT WITH A CHANCE OF THUNDER WED EVENING...GIVEN DEWPOINTS
IN THE UPPER 40S TO LOWER 50S. ALSO FAIRLY STRONG DYNAMICS
AND WIND FIELDS. LIMITING FACTOR FOR SEVERE STORMS WILL BE
TIME OF DAY AND THERMAL RIDGE WELL TO THE EAST OF THE FRONT.

WIND GUST COULD BE IN THE ADVISORY RANGE LATE.

DID NOT BUY INTO THE NAM SOLUTION AT THIS POINT.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
CLOUDS SHOULD BREAK BEHIND THE COLD FRONT ON THU. A FEW SNOW
AND RAIN SHOWERS WILL BE POSSIBLE WITH THE UPPER LEVEL TROUGH.
MUCH OF THE DAY WILL BE DRY. NOT REAL COLD BEHIND THE FRONT.

SW FLOW ON FRIDAY WILL BRING IN MILD AIR.

A FEW MORE SHOWERS LATE FRIDAY INTO SUNDAY...AS THE NEXT COLD
FRONT MOVES ACROSS THE AREA. SHOWERS WILL BE MAINLY IN THE
FORM OF SNOW SHOWERS.

WENT WITH MAINLY DRY CONDITIONS FOR MONDAY. NOT REAL COLD FOR
LATE DEC. THERE COULD BE SOME SNOW SHOWERS LATE MONDAY
NIGHT...BUT WENT WITH A DRY FCST FOR NOW.

WITH SPLIT FLOW...THERE COULD BE SOME CHANCE FOR A SOUTHERN
WAVE TO BRING SOME RAIN OR SNOW SHOWERS TO THE AREA ANYTIME
FROM SUNDAY INTO MID WEEK...BUT AT THIS TIME...LOOKS LIKE
ANYTHING WOULD BE FAST MOVING...AND MAINLY TO THE SOUTH.

&&

.AVIATION /21Z MONDAY THROUGH SATURDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST IS SPREADING AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA THIS AFTERNOON.
LOWER CIGS PUSHING NORTHWARD IN RESPONSE TO DEEPENING LLVL
MOISTURE AND ONSHORE FLOW. THE INCREASING MOISTURE...COMBINED WITH
LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE SE
STATES...WILL SPREAD LIGHT RAIN AND FREEZING RAIN ACROSS ALL OF
CENTRAL AND SOUTHERN PA THIS AFTERNOON AND EVENING...WITH IP AND
ZR POSSIBLE ACROSS THE NORTH LATER TONIGHT.

MAIN CONCERN REMAINS POTENTIAL FOR LIGHT ICING...GIVEN COLD AIR
DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE -FZRA IS FROM THE LAUREL
HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS NORTHWARD THROUGH THE
WEST CENTRAL MOUNTAINS EARLY THIS EVENING...SPREADING NORTH LATE
TONIGHT. SOUTHERN AREAS WILL WARM ABOVE FREEZING AFT 05Z CHANGING
PRECIP TO RAIN...BUT AREAS NORTH OF A KJST TO KAOO TO KSEG LINE
WILL LIKELY KEEP PATCHY FZRA OVERNIGHT ALONG WITH IFR CIGS AND
VSBYS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

SAT...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
PAZ024>028-033>036-056-063-064.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ065.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...MARTIN
LONG TERM...MARTIN
AVIATION...DEVOIR





000
FXUS61 KCTP 222049
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
349 PM EST MON DEC 22 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL BRING LIGHT RAIN AND FREEZING RAIN
TO CENTRAL AND EASTERN PA TONIGHT AS IT LIFTS UP THE MID ATLANTIC
COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF PENNSYLVANIA
WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH THE STATE. ANOTHER
LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE REGION BY NEXT
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
MOISTURE SLOWLY INCREASING ACROSS THE LAUREL HIGHLANDS...CENTRAL
MOUNTAINS AND LOWER SUSQ AT MID AFTERNOON. PRECIP HAS BROKEN OUT
OVER THE SOUTH CENTRAL MOUNTAINS WHERE SFC TEMPS ARE HOVERING
AROUND 32F AND SFC TD IS IN THE MID 20S. FZRA ADVISORY IN PLACE
THROUGH 05Z TONIGHT FOR LIGHT AMOUNTS OF ICE. LOWER SUSQ SHOULD
REMAIN ALL RAIN...BUT WESTERN PORTIONS OF YORK COUNTY IN THE
HIGHER TERRAIN IS ALSO EXPECTED TO SEE SOME ICE.

HI RES MODELS INDICATE A PROLONGED PERIOD OF FREEZING AND EVEN
SOME FROZEN (IP) HYDROMETEORS AS THE LIGHT SHIELD OF PRECIP LIFTS
NORTHWARD TONIGHT. BLEND OF TRENDS AND HI RES MODELS KEEP AREAS OF
FZDZ AND LCL SLEET OVER THE WESTERN...CENTRAL AND EVENTUALLY INTO
THE NORTH CENTRAL MOUNTAINS LATE TONIGHT. ADVISORIES MAY BE NEEDED
FOR THOSE NORTHERN AREAS LATER ON...BUT PRECIP MAY REMAIN FROZEN
(SLEET/SNOW MIXTURE THERE) SO HELD OFF FOR NOW.

EXPECT THE SOUTHERN TIER TO WARM SUFFICIENTLY TO CHANGE TO RAIN BY
OR AFTER 05Z. IT WILL TAKE MUCH LONGER FROM THE WEST CENTRAL
MOUNTAINS NORTHWARD. MINS WILL RANGE FROM THE UPPER 20S NORTH TO
THE LOWER 30S SOUTH.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
LOOKING AT MAINLY A CLOUDY DAY ON TUE...WITH SOME PATCHY
LIGHT RAIN. TEMPERATURES WILL BE ABOVE NORMAL...BUT MAINLY
IN THE 40S...AS THE MAIN LOW IS TOO FAR WEST FOR CENTRAL
PA TO BE IN MUCH OF A SOUTHERLY GRADIENT.

BETTER CHANCE OF RAIN LATER TUESDAY NIGHT INTO WED...AS
COLD FRONT MOVES TO THE EAST.

TEMPERATURES WILL CLIMB INTO THE 50S ON WED...AS STRONGER
SOUTHERLY WINDS DEVELOP.

WENT WITH A CHANCE OF THUNDER WED EVENING...GIVEN DEWPOINTS
IN THE UPPER 40S TO LOWER 50S. ALSO FAIRLY STRONG DYNAMICS
AND WIND FIELDS. LIMITING FACTOR FOR SEVERE STORMS WILL BE
TIME OF DAY AND THERMAL RIDGE WELL TO THE EAST OF THE FRONT.

WIND GUST COULD BE IN THE ADVISORY RANGE LATE.

DID NOT BUY INTO THE NAM SOLUTION AT THIS POINT.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
CLOUDS SHOULD BREAK BEHIND THE COLD FRONT ON THU. A FEW SNOW
AND RAIN SHOWERS WILL BE POSSIBLE WITH THE UPPER LEVEL TROUGH.
MUCH OF THE DAY WILL BE DRY. NOT REAL COLD BEHIND THE FRONT.

SW FLOW ON FRIDAY WILL BRING IN MILD AIR.

A FEW MORE SHOWERS LATE FRIDAY INTO SUNDAY...AS THE NEXT COLD
FRONT MOVES ACROSS THE AREA. SHOWERS WILL BE MAINLY IN THE
FORM OF SNOW SHOWERS.

WENT WITH MAINLY DRY CONDITIONS FOR MONDAY. NOT REAL COLD FOR
LATE DEC. THERE COULD BE SOME SNOW SHOWERS LATE MONDAY
NIGHT...BUT WENT WITH A DRY FCST FOR NOW.

WITH SPLIT FLOW...THERE COULD BE SOME CHANCE FOR A SOUTHERN
WAVE TO BRING SOME RAIN OR SNOW SHOWERS TO THE AREA ANYTIME
FROM SUNDAY INTO MID WEEK...BUT AT THIS TIME...LOOKS LIKE
ANYTHING WOULD BE FAST MOVING...AND MAINLY TO THE SOUTH.

&&

.AVIATION /21Z MONDAY THROUGH SATURDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST IS SPREADING AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA THIS AFTERNOON.
LOWER CIGS PUSHING NORTHWARD IN RESPONSE TO DEEPENING LLVL
MOISTURE AND ONSHORE FLOW. THE INCREASING MOISTURE...COMBINED WITH
LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE SE
STATES...WILL SPREAD LIGHT RAIN AND FREEZING RAIN ACROSS ALL OF
CENTRAL AND SOUTHERN PA THIS AFTERNOON AND EVENING...WITH IP AND
ZR POSSIBLE ACROSS THE NORTH LATER TONIGHT.

MAIN CONCERN REMAINS POTENTIAL FOR LIGHT ICING...GIVEN COLD AIR
DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE -FZRA IS FROM THE LAUREL
HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS NORTHWARD THROUGH THE
WEST CENTRAL MOUNTAINS EARLY THIS EVENING...SPREADING NORTH LATE
TONIGHT. SOUTHERN AREAS WILL WARM ABOVE FREEZING AFT 05Z CHANGING
PRECIP TO RAIN...BUT AREAS NORTH OF A KJST TO KAOO TO KSEG LINE
WILL LIKELY KEEP PATCHY FZRA OVERNIGHT ALONG WITH IFR CIGS AND
VSBYS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

SAT...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
PAZ024>028-033>036-056-063-064.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ065.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...MARTIN
LONG TERM...MARTIN
AVIATION...DEVOIR




000
FXUS61 KCTP 221941
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
241 PM EST MON DEC 22 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL BRING LIGHT RAIN AND FREEZING RAIN
TO CENTRAL AND EASTERN PA TONIGHT AS IT LIFTS UP THE MID ATLANTIC
COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF PENNSYLVANIA
WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH THE STATE. ANOTHER
LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE REGION BY NEXT
WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
MOISTURE SLOWLY INCREASING ACROSS THE LAUREL HIGHLANDS...CENTRAL
MOUNTAINS AND LOWER SUSQ AT MID AFTERNOON. PRECIP HAS BROKEN OUT
OVER THE SOUTH CENTRAL MOUNTAINS WHERE SFC TEMPS ARE HOVERING
AROUND 32F AND SFC TD IS IN THE MID 20S. FZRA ADVISORY IN PLACE
THROUGH 05Z TONIGHT FOR LIGHT AMOUNTS OF ICE. LOWER SUSQ SHOULD
REMAIN ALL RAIN...BUT WESTERN PORTIONS OF YORK COUNTY IN THE
HIGHER TERRAIN IS ALSO EXPECTED TO SEE SOME ICE.

HI RES MODELS INDICATE A PROLONGED PERIOD OF FREEZING AND EVEN
SOME FROZEN (IP) HYDROMETEORS AS THE LIGHT SHIELD OF PRECIP LIFTS
NORTHWARD TONIGHT. BLEND OF TRENDS AND HI RES MODELS KEEP AREAS OF
FZDZ AND LCL SLEET OVER THE WESTERN...CENTRAL AND EVENTUALLY INTO
THE NORTH CENTRAL MOUNTAINS LATE TONIGHT. ADVISORIES MAY BE NEEDED
FOR THOSE NORTHERN AREAS LATER ON...BUT PRECIP MAY REMAIN FROZEN
(SLEET/SNOW MIXTURE THERE) SO HELD OFF FOR NOW.

EXPECT THE SOUTHERN TIER TO WARM SUFFICIENTLY TO CHANGE TO RAIN BY
OR AFTER 05Z. IT WILL TAKE MUCH LONGER FROM THE WEST CENTRAL
MOUNTAINS NORTHWARD. MINS WILL RANGE FROM THE UPPER 20S NORTH TO
THE LOWER 30S SOUTH.

&&

.SHORT TERM /TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF
SHALLOW MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE
TONIGHT AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME
BTWN 00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD
OF MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE
DATA SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN
OF CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING
MOST LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST IS SPREADING AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA THIS AFTERNOON.
LOWER CIGS PUSHING NORTHWARD IN RESPONSE TO DEEPENING LLVL
MOISTURE AND ONSHORE FLOW. THE INCREASING MOISTURE...COMBINED WITH
LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE SE
STATES...WILL SPREAD LIGHT RAIN AND FREEZING RAIN ACROSS ALL OF
CENTRAL AND SOUTHERN PA THIS AFTERNOON AND EVENING...WITH IP AND
ZR POSSIBLE ACROSS THE NORTH LATER TONIGHT.

MAIN CONCERN REMAINS POTENTIAL FOR LIGHT ICING...GIVEN COLD AIR
DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE -FZRA IS FROM THE LAUREL
HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS NORTHWARD THROUGH THE
WEST CENTRAL MOUNTAINS EARLY THIS EVENING...SPREADING NORTH LATE
TONIGHT. SOUTHERN AREAS WILL WARM ABOVE FREEZING AFT 05Z CHANGING
PRECIP TO RAIN...BUT AREAS NORTH OF A KJST TO KAOO TO KSEG LINE
WILL LIKELY KEEP PATCHY FZRA OVERNIGHT ALONG WITH IFR CIGS AND
VSBYS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

SAT...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
PAZ024>028-033>036-056-063-064.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ065.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...MARTIN
LONG TERM...FITZGERALD
AVIATION...DEVOIR





000
FXUS61 KCTP 221941
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
241 PM EST MON DEC 22 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL BRING LIGHT RAIN AND FREEZING RAIN
TO CENTRAL AND EASTERN PA TONIGHT AS IT LIFTS UP THE MID ATLANTIC
COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF PENNSYLVANIA
WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH THE STATE. ANOTHER
LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE REGION BY NEXT
WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
MOISTURE SLOWLY INCREASING ACROSS THE LAUREL HIGHLANDS...CENTRAL
MOUNTAINS AND LOWER SUSQ AT MID AFTERNOON. PRECIP HAS BROKEN OUT
OVER THE SOUTH CENTRAL MOUNTAINS WHERE SFC TEMPS ARE HOVERING
AROUND 32F AND SFC TD IS IN THE MID 20S. FZRA ADVISORY IN PLACE
THROUGH 05Z TONIGHT FOR LIGHT AMOUNTS OF ICE. LOWER SUSQ SHOULD
REMAIN ALL RAIN...BUT WESTERN PORTIONS OF YORK COUNTY IN THE
HIGHER TERRAIN IS ALSO EXPECTED TO SEE SOME ICE.

HI RES MODELS INDICATE A PROLONGED PERIOD OF FREEZING AND EVEN
SOME FROZEN (IP) HYDROMETEORS AS THE LIGHT SHIELD OF PRECIP LIFTS
NORTHWARD TONIGHT. BLEND OF TRENDS AND HI RES MODELS KEEP AREAS OF
FZDZ AND LCL SLEET OVER THE WESTERN...CENTRAL AND EVENTUALLY INTO
THE NORTH CENTRAL MOUNTAINS LATE TONIGHT. ADVISORIES MAY BE NEEDED
FOR THOSE NORTHERN AREAS LATER ON...BUT PRECIP MAY REMAIN FROZEN
(SLEET/SNOW MIXTURE THERE) SO HELD OFF FOR NOW.

EXPECT THE SOUTHERN TIER TO WARM SUFFICIENTLY TO CHANGE TO RAIN BY
OR AFTER 05Z. IT WILL TAKE MUCH LONGER FROM THE WEST CENTRAL
MOUNTAINS NORTHWARD. MINS WILL RANGE FROM THE UPPER 20S NORTH TO
THE LOWER 30S SOUTH.

&&

.SHORT TERM /TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF
SHALLOW MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE
TONIGHT AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME
BTWN 00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD
OF MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE
DATA SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN
OF CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING
MOST LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST IS SPREADING AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA THIS AFTERNOON.
LOWER CIGS PUSHING NORTHWARD IN RESPONSE TO DEEPENING LLVL
MOISTURE AND ONSHORE FLOW. THE INCREASING MOISTURE...COMBINED WITH
LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE SE
STATES...WILL SPREAD LIGHT RAIN AND FREEZING RAIN ACROSS ALL OF
CENTRAL AND SOUTHERN PA THIS AFTERNOON AND EVENING...WITH IP AND
ZR POSSIBLE ACROSS THE NORTH LATER TONIGHT.

MAIN CONCERN REMAINS POTENTIAL FOR LIGHT ICING...GIVEN COLD AIR
DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE -FZRA IS FROM THE LAUREL
HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS NORTHWARD THROUGH THE
WEST CENTRAL MOUNTAINS EARLY THIS EVENING...SPREADING NORTH LATE
TONIGHT. SOUTHERN AREAS WILL WARM ABOVE FREEZING AFT 05Z CHANGING
PRECIP TO RAIN...BUT AREAS NORTH OF A KJST TO KAOO TO KSEG LINE
WILL LIKELY KEEP PATCHY FZRA OVERNIGHT ALONG WITH IFR CIGS AND
VSBYS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

SAT...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
PAZ024>028-033>036-056-063-064.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ065.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...MARTIN
LONG TERM...FITZGERALD
AVIATION...DEVOIR




000
FXUS61 KCTP 221759
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1259 PM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL RETREAT NORTHEAST INTO THE CANADIAN MARITIMES
EARLY THIS WEEK...AS A WEAK LOW PRESSURE SYSTEM LIFTS UP THE MID
ATLANTIC COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF
PENNSYLVANIA WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH
THE STATE. ANOTHER LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE
REGION BY NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOISTURE SLOWLY INCREASING NORTH OF THE MASON DIXON LINE AS
MARITIME INFLUENCE INCREASES ACROSS SOUTHERN AND EASTERN PA. AT 1
PM...FZDZ/DZ IS NEARING THE KHGR AREA WITH SFC TEMPS THERE AT 34F
(TD 25F). BLEND OF THESE TRENDS PLUS THE LATEST HI RES HRRR AND
4KM HRW ARW SAYS POCKETS OF FZDZ AND FZRA ARE POSSIBLE FROM EARLY
AFTERNOON ONWARD LIFTING NORTH OF THE MD BORDER AND COVERING MUCH
OF THE SOUTH CENTRAL MOUNTAINS AFT 20Z. BEST ICING CHANCES ARE LATE
THIS AFTERNOON IN THESE AREAS...LIFTING NORTHWARD INTO THE
LAURELS AND NORTHERN PARTS OF THE SOUTH CENTRAL MOUNTAINS BEFORE
DARK.

FZRA ADVISORIES IN EFFECT FOR THE LAURELS AND SOUTH CENTRAL
MOUNTAINS...ALTHOUGH WESTERN PORTIONS OF THE LAURELS MAY BE LEFT
OUT OF THE PRECIP FOR SEVERAL HOURS (UNTIL WELL PAST DARK).

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF
SHALLOW MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE
TONIGHT AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME
BTWN 00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD
OF MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE
DATA SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN
OF CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING
MOST LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. LOWER CIGS
LIFTING NORTHWARD THIS MORNING IN RESPONSE TO DEEPENING LLVL
MOISTURE AND ONSHORE FLOW. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE SE
STATES...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA LATE
THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME LIGHT ICING...GIVEN COLD
AIR DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY LIGHT -FZRA WOULD BE OVR
THE LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS...WITH A
BETTER CHANCE TONIGHT ACROSS THE CENTRAL MTNS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
PAZ024>028-033>036-056-063-064.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ065.

&&

$$
SYNOPSIS...DEVOIR/FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...FITZGERALD
AVIATION...DEVOIR





000
FXUS61 KCTP 221759
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1259 PM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL RETREAT NORTHEAST INTO THE CANADIAN MARITIMES
EARLY THIS WEEK...AS A WEAK LOW PRESSURE SYSTEM LIFTS UP THE MID
ATLANTIC COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF
PENNSYLVANIA WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH
THE STATE. ANOTHER LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE
REGION BY NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MOISTURE SLOWLY INCREASING NORTH OF THE MASON DIXON LINE AS
MARITIME INFLUENCE INCREASES ACROSS SOUTHERN AND EASTERN PA. AT 1
PM...FZDZ/DZ IS NEARING THE KHGR AREA WITH SFC TEMPS THERE AT 34F
(TD 25F). BLEND OF THESE TRENDS PLUS THE LATEST HI RES HRRR AND
4KM HRW ARW SAYS POCKETS OF FZDZ AND FZRA ARE POSSIBLE FROM EARLY
AFTERNOON ONWARD LIFTING NORTH OF THE MD BORDER AND COVERING MUCH
OF THE SOUTH CENTRAL MOUNTAINS AFT 20Z. BEST ICING CHANCES ARE LATE
THIS AFTERNOON IN THESE AREAS...LIFTING NORTHWARD INTO THE
LAURELS AND NORTHERN PARTS OF THE SOUTH CENTRAL MOUNTAINS BEFORE
DARK.

FZRA ADVISORIES IN EFFECT FOR THE LAURELS AND SOUTH CENTRAL
MOUNTAINS...ALTHOUGH WESTERN PORTIONS OF THE LAURELS MAY BE LEFT
OUT OF THE PRECIP FOR SEVERAL HOURS (UNTIL WELL PAST DARK).

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF
SHALLOW MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE
TONIGHT AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME
BTWN 00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD
OF MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE
DATA SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN
OF CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING
MOST LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. LOWER CIGS
LIFTING NORTHWARD THIS MORNING IN RESPONSE TO DEEPENING LLVL
MOISTURE AND ONSHORE FLOW. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE SE
STATES...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA LATE
THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME LIGHT ICING...GIVEN COLD
AIR DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY LIGHT -FZRA WOULD BE OVR
THE LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS...WITH A
BETTER CHANCE TONIGHT ACROSS THE CENTRAL MTNS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
PAZ024>028-033>036-056-063-064.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ065.

&&

$$
SYNOPSIS...DEVOIR/FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...DEVOIR/FITZGERALD
LONG TERM...FITZGERALD
AVIATION...DEVOIR




000
FXUS61 KCTP 221612
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1112 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL RETREAT NORTHEAST INTO THE CANADIAN MARITIMES
EARLY THIS WEEK...AS A WEAK LOW PRESSURE SYSTEM LIFTS UP THE MID
ATLANTIC COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF
PENNSYLVANIA WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH
THE STATE. ANOTHER LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE
REGION BY NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
16Z UPDATE** COLLAB WITH LWX AND PBZ ON ISSUING WSW ADVISORY FOR
FREEZING RAIN OVER LAURELS AND SOUTH CENTRAL MOUNTAINS.

LOW CLOUDS LIFTING CENTRAL MOUNTAINS AT MID MORNING
WITH DEEPER MOISTURE STARTING TO POOL SOUTH OF THE MASON DIXON
LINE...IN RESPONSE TO INCREASING MARITIME INFLUENCE IN INCREASING
EASTERLY/ONSHORE FLOW BETWEEN CAPE HATTERAS LOW PRESSURE AND
NORTHERN NEW ENGLANHIGH PRESSURE. THE INCREASING
MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF SHORTWAVE
LIFTING OUT THE SE STATES...COULD SPREAD A BIT OF LIGHT RAIN INTO
SOUTHERN PA THIS AFTN. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC
POPS ACROSS THE SOUTHERN COUNTIES THIS AFTN.

FOR THE DAY...THE MAIN CONCERN FOCUSES ON POTENTIAL OF SOME ICING
LATER ON... GIVEN COLD AIR DAMMING AND LLVL AGEOSTROPHIC NLY FLOW
LOCKING THE COLD AIR IN. LATEST HRRR AND 4KM HRW-ARW DIFFER
SIGNIFICANTLY ON ARRIVAL OF PRECIP INTO SOUTH CENTRAL PA. LATEST
HRW-ARW HAS COME INTO LINE WITH PREVIOUS HRRR HOWEVER...IN
DELAYING PRECIP UNTIL AFTER 20Z...AND MOST OF THAT BEING RAIN
OVERF THE LOWER SUSQ RIVER VALLEY.

THUS...LATEST HI RES RUNS...FORECAST SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST ICING CHANCE LATE THIS AFTERNOON...STARTING NEAR
THE MASON DIXON LINE MID TO LATE AFTERNOON...AND LIFTING NORTHWARD
INTO THE LAURELS AND SOUTH CENTRAL MOUNTAINS BEFORE DARK.

STILL NO ADVY TO BE POSTED AT THIS TIME DUE TO THE LOW CERTAINTY
OF MEASURABLE FZRA...BUT CONFIDENCE INCREASING FROM ADAMS COUNTY
WESTWARD THAT AN ADVISORY MAY BE NEEDED FROM ADAMS COUNTY WESTWARD
MID TO LATE AFTERNOON. WILL MONITOR TRENDS AND ISSUE ACCORDINGLY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF
SHALLOW MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE
TONIGHT AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME
BTWN 00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD
OF MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE
DATA SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN
OF CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING
MOST LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. LOWER CIGS
LIFTING NORTHWARD THIS MORNING IN RESPONSE TO DEEPENING LLVL
MOISTURE AND ONSHORE FLOW. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE SE
STATES...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA LATE
THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME LIGHT ICING...GIVEN COLD
AIR DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY LIGHT -FZRA WOULD BE OVR
THE LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS...WITH A
BETTER CHANCE TONIGHT ACROSS THE CENTRAL MTNS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
PAZ024>028-033>036-056-063-064.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ065.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...DEVOIR/RXR





000
FXUS61 KCTP 221612
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1112 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL RETREAT NORTHEAST INTO THE CANADIAN MARITIMES
EARLY THIS WEEK...AS A WEAK LOW PRESSURE SYSTEM LIFTS UP THE MID
ATLANTIC COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF
PENNSYLVANIA WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH
THE STATE. ANOTHER LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE
REGION BY NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
16Z UPDATE** COLLAB WITH LWX AND PBZ ON ISSUING WSW ADVISORY FOR
FREEZING RAIN OVER LAURELS AND SOUTH CENTRAL MOUNTAINS.

LOW CLOUDS LIFTING CENTRAL MOUNTAINS AT MID MORNING
WITH DEEPER MOISTURE STARTING TO POOL SOUTH OF THE MASON DIXON
LINE...IN RESPONSE TO INCREASING MARITIME INFLUENCE IN INCREASING
EASTERLY/ONSHORE FLOW BETWEEN CAPE HATTERAS LOW PRESSURE AND
NORTHERN NEW ENGLANHIGH PRESSURE. THE INCREASING
MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF SHORTWAVE
LIFTING OUT THE SE STATES...COULD SPREAD A BIT OF LIGHT RAIN INTO
SOUTHERN PA THIS AFTN. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC
POPS ACROSS THE SOUTHERN COUNTIES THIS AFTN.

FOR THE DAY...THE MAIN CONCERN FOCUSES ON POTENTIAL OF SOME ICING
LATER ON... GIVEN COLD AIR DAMMING AND LLVL AGEOSTROPHIC NLY FLOW
LOCKING THE COLD AIR IN. LATEST HRRR AND 4KM HRW-ARW DIFFER
SIGNIFICANTLY ON ARRIVAL OF PRECIP INTO SOUTH CENTRAL PA. LATEST
HRW-ARW HAS COME INTO LINE WITH PREVIOUS HRRR HOWEVER...IN
DELAYING PRECIP UNTIL AFTER 20Z...AND MOST OF THAT BEING RAIN
OVERF THE LOWER SUSQ RIVER VALLEY.

THUS...LATEST HI RES RUNS...FORECAST SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST ICING CHANCE LATE THIS AFTERNOON...STARTING NEAR
THE MASON DIXON LINE MID TO LATE AFTERNOON...AND LIFTING NORTHWARD
INTO THE LAURELS AND SOUTH CENTRAL MOUNTAINS BEFORE DARK.

STILL NO ADVY TO BE POSTED AT THIS TIME DUE TO THE LOW CERTAINTY
OF MEASURABLE FZRA...BUT CONFIDENCE INCREASING FROM ADAMS COUNTY
WESTWARD THAT AN ADVISORY MAY BE NEEDED FROM ADAMS COUNTY WESTWARD
MID TO LATE AFTERNOON. WILL MONITOR TRENDS AND ISSUE ACCORDINGLY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF
SHALLOW MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE
TONIGHT AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME
BTWN 00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD
OF MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE
DATA SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN
OF CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING
MOST LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. LOWER CIGS
LIFTING NORTHWARD THIS MORNING IN RESPONSE TO DEEPENING LLVL
MOISTURE AND ONSHORE FLOW. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE SE
STATES...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA LATE
THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME LIGHT ICING...GIVEN COLD
AIR DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY LIGHT -FZRA WOULD BE OVR
THE LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS...WITH A
BETTER CHANCE TONIGHT ACROSS THE CENTRAL MTNS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
PAZ024>028-033>036-056-063-064.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ065.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...DEVOIR/RXR




000
FXUS61 KCTP 221612
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1112 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL RETREAT NORTHEAST INTO THE CANADIAN MARITIMES
EARLY THIS WEEK...AS A WEAK LOW PRESSURE SYSTEM LIFTS UP THE MID
ATLANTIC COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF
PENNSYLVANIA WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH
THE STATE. ANOTHER LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE
REGION BY NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
16Z UPDATE** COLLAB WITH LWX AND PBZ ON ISSUING WSW ADVISORY FOR
FREEZING RAIN OVER LAURELS AND SOUTH CENTRAL MOUNTAINS.

LOW CLOUDS LIFTING CENTRAL MOUNTAINS AT MID MORNING
WITH DEEPER MOISTURE STARTING TO POOL SOUTH OF THE MASON DIXON
LINE...IN RESPONSE TO INCREASING MARITIME INFLUENCE IN INCREASING
EASTERLY/ONSHORE FLOW BETWEEN CAPE HATTERAS LOW PRESSURE AND
NORTHERN NEW ENGLANHIGH PRESSURE. THE INCREASING
MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF SHORTWAVE
LIFTING OUT THE SE STATES...COULD SPREAD A BIT OF LIGHT RAIN INTO
SOUTHERN PA THIS AFTN. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC
POPS ACROSS THE SOUTHERN COUNTIES THIS AFTN.

FOR THE DAY...THE MAIN CONCERN FOCUSES ON POTENTIAL OF SOME ICING
LATER ON... GIVEN COLD AIR DAMMING AND LLVL AGEOSTROPHIC NLY FLOW
LOCKING THE COLD AIR IN. LATEST HRRR AND 4KM HRW-ARW DIFFER
SIGNIFICANTLY ON ARRIVAL OF PRECIP INTO SOUTH CENTRAL PA. LATEST
HRW-ARW HAS COME INTO LINE WITH PREVIOUS HRRR HOWEVER...IN
DELAYING PRECIP UNTIL AFTER 20Z...AND MOST OF THAT BEING RAIN
OVERF THE LOWER SUSQ RIVER VALLEY.

THUS...LATEST HI RES RUNS...FORECAST SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST ICING CHANCE LATE THIS AFTERNOON...STARTING NEAR
THE MASON DIXON LINE MID TO LATE AFTERNOON...AND LIFTING NORTHWARD
INTO THE LAURELS AND SOUTH CENTRAL MOUNTAINS BEFORE DARK.

STILL NO ADVY TO BE POSTED AT THIS TIME DUE TO THE LOW CERTAINTY
OF MEASURABLE FZRA...BUT CONFIDENCE INCREASING FROM ADAMS COUNTY
WESTWARD THAT AN ADVISORY MAY BE NEEDED FROM ADAMS COUNTY WESTWARD
MID TO LATE AFTERNOON. WILL MONITOR TRENDS AND ISSUE ACCORDINGLY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF
SHALLOW MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE
TONIGHT AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME
BTWN 00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD
OF MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE
DATA SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN
OF CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING
MOST LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. LOWER CIGS
LIFTING NORTHWARD THIS MORNING IN RESPONSE TO DEEPENING LLVL
MOISTURE AND ONSHORE FLOW. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE SE
STATES...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA LATE
THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME LIGHT ICING...GIVEN COLD
AIR DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY LIGHT -FZRA WOULD BE OVR
THE LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS...WITH A
BETTER CHANCE TONIGHT ACROSS THE CENTRAL MTNS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
PAZ024>028-033>036-056-063-064.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ065.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...DEVOIR/RXR





000
FXUS61 KCTP 221612
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1112 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL RETREAT NORTHEAST INTO THE CANADIAN MARITIMES
EARLY THIS WEEK...AS A WEAK LOW PRESSURE SYSTEM LIFTS UP THE MID
ATLANTIC COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF
PENNSYLVANIA WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH
THE STATE. ANOTHER LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE
REGION BY NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
16Z UPDATE** COLLAB WITH LWX AND PBZ ON ISSUING WSW ADVISORY FOR
FREEZING RAIN OVER LAURELS AND SOUTH CENTRAL MOUNTAINS.

LOW CLOUDS LIFTING CENTRAL MOUNTAINS AT MID MORNING
WITH DEEPER MOISTURE STARTING TO POOL SOUTH OF THE MASON DIXON
LINE...IN RESPONSE TO INCREASING MARITIME INFLUENCE IN INCREASING
EASTERLY/ONSHORE FLOW BETWEEN CAPE HATTERAS LOW PRESSURE AND
NORTHERN NEW ENGLANHIGH PRESSURE. THE INCREASING
MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF SHORTWAVE
LIFTING OUT THE SE STATES...COULD SPREAD A BIT OF LIGHT RAIN INTO
SOUTHERN PA THIS AFTN. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC
POPS ACROSS THE SOUTHERN COUNTIES THIS AFTN.

FOR THE DAY...THE MAIN CONCERN FOCUSES ON POTENTIAL OF SOME ICING
LATER ON... GIVEN COLD AIR DAMMING AND LLVL AGEOSTROPHIC NLY FLOW
LOCKING THE COLD AIR IN. LATEST HRRR AND 4KM HRW-ARW DIFFER
SIGNIFICANTLY ON ARRIVAL OF PRECIP INTO SOUTH CENTRAL PA. LATEST
HRW-ARW HAS COME INTO LINE WITH PREVIOUS HRRR HOWEVER...IN
DELAYING PRECIP UNTIL AFTER 20Z...AND MOST OF THAT BEING RAIN
OVERF THE LOWER SUSQ RIVER VALLEY.

THUS...LATEST HI RES RUNS...FORECAST SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST ICING CHANCE LATE THIS AFTERNOON...STARTING NEAR
THE MASON DIXON LINE MID TO LATE AFTERNOON...AND LIFTING NORTHWARD
INTO THE LAURELS AND SOUTH CENTRAL MOUNTAINS BEFORE DARK.

STILL NO ADVY TO BE POSTED AT THIS TIME DUE TO THE LOW CERTAINTY
OF MEASURABLE FZRA...BUT CONFIDENCE INCREASING FROM ADAMS COUNTY
WESTWARD THAT AN ADVISORY MAY BE NEEDED FROM ADAMS COUNTY WESTWARD
MID TO LATE AFTERNOON. WILL MONITOR TRENDS AND ISSUE ACCORDINGLY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF
SHALLOW MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE
TONIGHT AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME
BTWN 00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD
OF MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE
DATA SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN
OF CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING
MOST LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. LOWER CIGS
LIFTING NORTHWARD THIS MORNING IN RESPONSE TO DEEPENING LLVL
MOISTURE AND ONSHORE FLOW. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE SE
STATES...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA LATE
THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME LIGHT ICING...GIVEN COLD
AIR DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY LIGHT -FZRA WOULD BE OVR
THE LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS...WITH A
BETTER CHANCE TONIGHT ACROSS THE CENTRAL MTNS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
PAZ024>028-033>036-056-063-064.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR PAZ065.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...DEVOIR/RXR




000
FXUS61 KCTP 221525
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1025 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL RETREAT NORTHEAST INTO THE CANADIAN MARITIMES
EARLY THIS WEEK...AS A WEAK LOW PRESSURE SYSTEM LIFTS UP THE MID
ATLANTIC COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF
PENNSYLVANIA WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH
THE STATE. ANOTHER LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE
REGION BY NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
15Z UPDATE** LOW CLOUDS LIFTING CENTRAL MOUNTAINS AT MID
MORNING WITH DEEPER MOISTURE STARTING TO POOL SOUTH OF THE MASON
DIXON LINE...IN RESPONSE TO INCREASING MARITIME INFLUENCE IN
INCREASING EASTERLY/ONSHORE FLOW BETWEEN CAPE HATTERAS LOW
PRESSURE AND NORTHERN NEW ENGLANHIGH PRESSURE. THE INCREASING
MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF SHORTWAVE
LIFTING OUT THE SE STATES...COULD SPREAD A BIT OF LIGHT RAIN INTO
SOUTHERN PA THIS AFTN. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC
POPS ACROSS THE SOUTHERN COUNTIES THIS AFTN.

FOR THE DAY...THE MAIN CONCERN FOCUSES ON POTENTIAL OF SOME ICING
LATER ON... GIVEN COLD AIR DAMMING AND LLVL AGEOSTROPHIC NLY FLOW
LOCKING THE COLD AIR IN. LATEST HRRR AND 4KM HRW-ARW DIFFER
SIGNIFICANTLY ON ARRIVAL OF PRECIP INTO SOUTH CENTRAL PA. LATEST
HRW-ARW HAS COME INTO LINE WITH PREVIOUS HRRR HOWEVER...IN
DELAYING PRECIP UNTIL AFTER 20Z...AND MOST OF THAT BEING RAIN
OVERF THE LOWER SUSQ RIVER VALLEY.

THUS...LATEST HI RES RUNS...FORECAST SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST ICING CHANCE LATE THIS AFTERNOON...STARTING NEAR
THE MASON DIXON LINE MID TO LATE AFTERNOON...AND LIFTING NORTHWARD
INTO THE LAURELS AND SOUTH CENTRAL MOUNTAINS BEFORE DARK.

STILL NO ADVY TO BE POSTED AT THIS TIME DUE TO THE LOW CERTAINTY
OF MEASURABLE FZRA...BUT CONFIDENCE INCREASING FROM ADAMS COUNTY
WESTWARD THAT AN ADVISORY MAY BE NEEDED FROM ADAMS COUNTY WESTWARD
MID TO LATE AFTERNOON. WILL MONITOR TRENDS AND ISSUE ACCORDINGLY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF
SHALLOW MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE
TONIGHT AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME
BTWN 00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD
OF MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE
DATA SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN
OF CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING
MOST LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. LOWER CIGS
LIFTING NORTHWARD THIS MORNING IN RESPONSE TO DEEPENING LLVL
MOISTURE AND ONSHORE FLOW. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE SE
STATES...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA LATE
THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME LIGHT ICING...GIVEN COLD
AIR DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY LIGHT -FZRA WOULD BE OVR
THE LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS...WITH A
BETTER CHANCE TONIGHT ACROSS THE CENTRAL MTNS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...RXR




000
FXUS61 KCTP 221525
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1025 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL RETREAT NORTHEAST INTO THE CANADIAN MARITIMES
EARLY THIS WEEK...AS A WEAK LOW PRESSURE SYSTEM LIFTS UP THE MID
ATLANTIC COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF
PENNSYLVANIA WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH
THE STATE. ANOTHER LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE
REGION BY NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
15Z UPDATE** LOW CLOUDS LIFTING CENTRAL MOUNTAINS AT MID
MORNING WITH DEEPER MOISTURE STARTING TO POOL SOUTH OF THE MASON
DIXON LINE...IN RESPONSE TO INCREASING MARITIME INFLUENCE IN
INCREASING EASTERLY/ONSHORE FLOW BETWEEN CAPE HATTERAS LOW
PRESSURE AND NORTHERN NEW ENGLANHIGH PRESSURE. THE INCREASING
MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF SHORTWAVE
LIFTING OUT THE SE STATES...COULD SPREAD A BIT OF LIGHT RAIN INTO
SOUTHERN PA THIS AFTN. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC
POPS ACROSS THE SOUTHERN COUNTIES THIS AFTN.

FOR THE DAY...THE MAIN CONCERN FOCUSES ON POTENTIAL OF SOME ICING
LATER ON... GIVEN COLD AIR DAMMING AND LLVL AGEOSTROPHIC NLY FLOW
LOCKING THE COLD AIR IN. LATEST HRRR AND 4KM HRW-ARW DIFFER
SIGNIFICANTLY ON ARRIVAL OF PRECIP INTO SOUTH CENTRAL PA. LATEST
HRW-ARW HAS COME INTO LINE WITH PREVIOUS HRRR HOWEVER...IN
DELAYING PRECIP UNTIL AFTER 20Z...AND MOST OF THAT BEING RAIN
OVERF THE LOWER SUSQ RIVER VALLEY.

THUS...LATEST HI RES RUNS...FORECAST SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST ICING CHANCE LATE THIS AFTERNOON...STARTING NEAR
THE MASON DIXON LINE MID TO LATE AFTERNOON...AND LIFTING NORTHWARD
INTO THE LAURELS AND SOUTH CENTRAL MOUNTAINS BEFORE DARK.

STILL NO ADVY TO BE POSTED AT THIS TIME DUE TO THE LOW CERTAINTY
OF MEASURABLE FZRA...BUT CONFIDENCE INCREASING FROM ADAMS COUNTY
WESTWARD THAT AN ADVISORY MAY BE NEEDED FROM ADAMS COUNTY WESTWARD
MID TO LATE AFTERNOON. WILL MONITOR TRENDS AND ISSUE ACCORDINGLY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF
SHALLOW MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE
TONIGHT AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME
BTWN 00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD
OF MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE
DATA SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN
OF CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING
MOST LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. LOWER CIGS
LIFTING NORTHWARD THIS MORNING IN RESPONSE TO DEEPENING LLVL
MOISTURE AND ONSHORE FLOW. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE SE
STATES...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA LATE
THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME LIGHT ICING...GIVEN COLD
AIR DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY LIGHT -FZRA WOULD BE OVR
THE LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS...WITH A
BETTER CHANCE TONIGHT ACROSS THE CENTRAL MTNS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...RXR





000
FXUS61 KCTP 221159
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
659 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL RETREAT NORTHEAST INTO THE CANADIAN MARITIMES
EARLY THIS WEEK...AS A WEAK LOW PRESSURE SYSTEM LIFTS UP THE MID
ATLANTIC COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF
PENNSYLVANIA WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH
THE STATE. ANOTHER LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE
REGION BY NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. EARLY AM
IR LOOP SHOWS MAINLY SKIES ACROSS CENTRAL PA. HOWEVER...SOME
STRATUS HAS ALREADY CREPT INTO THE SC MTNS AS OF 09Z AND MDL
SOUNDINGS STILL SUPPORT THE IDEA OF INCREASING CLOUDS FROM SOUTH
TO NORTH TODAY.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE SE STATES...COULD SPREAD A BIT OF LIGHT
RAIN INTO SOUTHERN PA THIS AFTN. BLEND OF LATEST MDL GUIDANCE
SUPPORTS CHC POPS ACROSS THE SOUTHERN COUNTIES THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME ICING...GIVEN COLD AIR
DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY -FZRA WOULD BE OVR THE
LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS. STILL NO ADVY
TO BE POSTED AT THIS TIME DUE TO THE LOW CERTAINTY OF MEASURABLE
FZRA. THERE APPEARS A BETTER CHANCE TONIGHT ACROSS THE CENTRAL
MTNS. HOWEVER...GIVEN THAT THIS AREA WILL BE ON THE WESTWARD
FRINGE OF MEASURABLE PRECIP...WILL WAIT FOR 12Z GUIDANCE TO GAUGE
THE NEED FOR AN ADVISORY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE TONIGHT
AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME BTWN
00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD OF
MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN OF
CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING MOST
LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. AN AREA OF
MVFR CIGS IS CREEPING IN FROM THE EAST /FROM KRDG-KIPT/ WHILE
ANOTHER AREA OF SLIGHTLY HIGHER CIGS WORKING INTO THE SOUTHERN
MTNS FROM THE SW. THESE SHOULD CONVERGE OVER THE SUSQ VALLEY TODAY
BRINGING LOW VFR OR POSS A PERIOD OF MVFR CIGS TO KMDT-KLNS.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE SE STATES...COULD SPREAD A BIT OF LIGHT
RAIN INTO SOUTHERN PA LATE THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME LIGHT ICING...GIVEN COLD
AIR DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY LIGHT -FZRA WOULD BE OVR
THE LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS...WITH A
BETTER CHANCE TONIGHT ACROSS THE CENTRAL MTNS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...RXR




000
FXUS61 KCTP 221159
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
659 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL RETREAT NORTHEAST INTO THE CANADIAN MARITIMES
EARLY THIS WEEK...AS A WEAK LOW PRESSURE SYSTEM LIFTS UP THE MID
ATLANTIC COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF
PENNSYLVANIA WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH
THE STATE. ANOTHER LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE
REGION BY NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. EARLY AM
IR LOOP SHOWS MAINLY SKIES ACROSS CENTRAL PA. HOWEVER...SOME
STRATUS HAS ALREADY CREPT INTO THE SC MTNS AS OF 09Z AND MDL
SOUNDINGS STILL SUPPORT THE IDEA OF INCREASING CLOUDS FROM SOUTH
TO NORTH TODAY.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE SE STATES...COULD SPREAD A BIT OF LIGHT
RAIN INTO SOUTHERN PA THIS AFTN. BLEND OF LATEST MDL GUIDANCE
SUPPORTS CHC POPS ACROSS THE SOUTHERN COUNTIES THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME ICING...GIVEN COLD AIR
DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY -FZRA WOULD BE OVR THE
LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS. STILL NO ADVY
TO BE POSTED AT THIS TIME DUE TO THE LOW CERTAINTY OF MEASURABLE
FZRA. THERE APPEARS A BETTER CHANCE TONIGHT ACROSS THE CENTRAL
MTNS. HOWEVER...GIVEN THAT THIS AREA WILL BE ON THE WESTWARD
FRINGE OF MEASURABLE PRECIP...WILL WAIT FOR 12Z GUIDANCE TO GAUGE
THE NEED FOR AN ADVISORY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE TONIGHT
AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME BTWN
00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD OF
MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN OF
CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING MOST
LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. AN AREA OF
MVFR CIGS IS CREEPING IN FROM THE EAST /FROM KRDG-KIPT/ WHILE
ANOTHER AREA OF SLIGHTLY HIGHER CIGS WORKING INTO THE SOUTHERN
MTNS FROM THE SW. THESE SHOULD CONVERGE OVER THE SUSQ VALLEY TODAY
BRINGING LOW VFR OR POSS A PERIOD OF MVFR CIGS TO KMDT-KLNS.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE SE STATES...COULD SPREAD A BIT OF LIGHT
RAIN INTO SOUTHERN PA LATE THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME LIGHT ICING...GIVEN COLD
AIR DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY LIGHT -FZRA WOULD BE OVR
THE LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS...WITH A
BETTER CHANCE TONIGHT ACROSS THE CENTRAL MTNS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...RXR





000
FXUS61 KCTP 221159
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
659 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL RETREAT NORTHEAST INTO THE CANADIAN MARITIMES
EARLY THIS WEEK...AS A WEAK LOW PRESSURE SYSTEM LIFTS UP THE MID
ATLANTIC COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF
PENNSYLVANIA WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH
THE STATE. ANOTHER LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE
REGION BY NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. EARLY AM
IR LOOP SHOWS MAINLY SKIES ACROSS CENTRAL PA. HOWEVER...SOME
STRATUS HAS ALREADY CREPT INTO THE SC MTNS AS OF 11Z AND MDL
SOUNDINGS STILL SUPPORT THE IDEA OF INCREASING CLOUDS FROM SOUTH
TO NORTH TODAY.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE SE STATES...COULD SPREAD A BIT OF LIGHT
RAIN INTO SOUTHERN PA THIS AFTN. BLEND OF LATEST MDL GUIDANCE
SUPPORTS CHC POPS ACROSS THE SOUTHERN COUNTIES THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME ICING...GIVEN COLD AIR
DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY -FZRA WOULD BE OVR THE
LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS. STILL NO ADVY
TO BE POSTED AT THIS TIME DUE TO THE LOW CERTAINTY OF MEASURABLE
FZRA. THERE APPEARS A BETTER CHANCE TONIGHT ACROSS THE CENTRAL
MTNS. HOWEVER...GIVEN THAT THIS AREA WILL BE ON THE WESTWARD
FRINGE OF MEASURABLE PRECIP...WILL WAIT FOR 12Z GUIDANCE TO GAUGE
THE NEED FOR AN ADVISORY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE TONIGHT
AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME BTWN
00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD OF
MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN OF
CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING MOST
LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. AN AREA OF
MVFR CIGS IS CREEPING IN FROM THE EAST /FROM KRDG-KIPT/ WHILE
ANOTHER AREA OF SLIGHTLY HIGHER CIGS WORKING INTO THE SOUTHERN
MTNS FROM THE SW. THESE SHOULD CONVERGE OVER THE SUSQ VALLEY TODAY
BRINGING LOW VFR OR POSS A PERIOD OF MVFR CIGS TO KMDT-KLNS.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE SE STATES...COULD SPREAD A BIT OF LIGHT
RAIN INTO SOUTHERN PA LATE THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME LIGHT ICING...GIVEN COLD
AIR DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY LIGHT -FZRA WOULD BE OVR
THE LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS...WITH A
BETTER CHANCE TONIGHT ACROSS THE CENTRAL MTNS.

OUTLOOK...

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BECOMING BREEZY
MAINLY ACROSS HIGHER TERRAIN. LLWS POSS N/W.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. BREEZY.
LLWS LIKELY.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...RXR





000
FXUS61 KCTP 221036
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
536 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL RETREAT NORTHEAST INTO THE CANADIAN MARITIMES
EARLY THIS WEEK...AS A WEAK LOW PRESSURE SYSTEM LIFTS UP THE MID
ATLANTIC COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF
PENNSYLVANIA WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH
THE STATE. ANOTHER LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE
REGION BY NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. EARLY AM
IR LOOP SHOWS MAINLY SKIES ACROSS CENTRAL PA. HOWEVER...SOME
STRATUS HAS ALREADY CREPT INTO THE SC MTNS AS OF 09Z AND MDL
SOUNDINGS STILL SUPPORT THE IDEA OF INCREASING CLOUDS FROM SOUTH
TO NORTH TODAY.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE SE STATES...COULD SPREAD A BIT OF LIGHT
RAIN INTO SOUTHERN PA THIS AFTN. BLEND OF LATEST MDL GUIDANCE
SUPPORTS CHC POPS ACROSS THE SOUTHERN COUNTIES THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME ICING...GIVEN COLD AIR
DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY -FZRA WOULD BE OVR THE
LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS. STILL NO ADVY
TO BE POSTED AT THIS TIME DUE TO THE LOW CERTAINTY OF MEASURABLE
FZRA. THERE APPEARS A BETTER CHANCE TONIGHT ACROSS THE CENTRAL
MTNS. HOWEVER...GIVEN THAT THIS AREA WILL BE ON THE WESTWARD
FRINGE OF MEASURABLE PRECIP...WILL WAIT FOR 12Z GUIDANCE TO GAUGE
THE NEED FOR AN ADVISORY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE TONIGHT
AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME BTWN
00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD OF
MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN OF
CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING MOST
LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /10Z MONDAY THROUGH FRIDAY/...
THE PATTERN CONTINUES AS STRATOCU IS TRAPPED UNDER AN INVERSION
THROUGH MAINLY THE NORTH. THE REST OF THE REGION HAS CLEARED. THE
QUESTION OVERNIGHT IS THAT WHETHER ANY OF THE WEAK SOUTHERLY FLOW
ALLOWS FOR STRATOCU TO THICKEN. WITH LIGHT WINDS

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESPECIALLY MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
OVERNIGHT...THOUGH ANY MID CLOUDS WILL REDUCE FORMATION. EXPECT
MVFR POSSIBLE AT JST AND AOO BETWEEN 09 TO 12Z. THOUGH IFR SHOULD
CONTINUE AT BFD OVERNIGHT INTO TOMORROW.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 221036
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
536 AM EST MON DEC 22 2014

.SYNOPSIS...
HIGH PRESSURE WILL RETREAT NORTHEAST INTO THE CANADIAN MARITIMES
EARLY THIS WEEK...AS A WEAK LOW PRESSURE SYSTEM LIFTS UP THE MID
ATLANTIC COAST. AN INTENSIFYING STORM SYSTEM WILL TRACK WEST OF
PENNSYLVANIA WEDNESDAY NIGHT...PUSHING A COLD FRONT THROUGH
THE STATE. ANOTHER LESS POTENT COLD FRONT IS LIKELY TO IMPACT THE
REGION BY NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COMBINATION OF RETREATING HIGH PRES OVR THE CANADIAN MARITIMES AND
WEAK LOW LIFTING UP THE MID ATLANTIC COAST WILL SPREAD AN
INCREASINGLY MOIST SERLY FLOW INTO CENTRAL PA ON TODAY. EARLY AM
IR LOOP SHOWS MAINLY SKIES ACROSS CENTRAL PA. HOWEVER...SOME
STRATUS HAS ALREADY CREPT INTO THE SC MTNS AS OF 09Z AND MDL
SOUNDINGS STILL SUPPORT THE IDEA OF INCREASING CLOUDS FROM SOUTH
TO NORTH TODAY.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE SE STATES...COULD SPREAD A BIT OF LIGHT
RAIN INTO SOUTHERN PA THIS AFTN. BLEND OF LATEST MDL GUIDANCE
SUPPORTS CHC POPS ACROSS THE SOUTHERN COUNTIES THIS AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME ICING...GIVEN COLD AIR
DAMMING SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY
FLOW HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS
PTYPES SUGGEST THE BEST CHC OF LATE DAY -FZRA WOULD BE OVR THE
LAUREL HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS. STILL NO ADVY
TO BE POSTED AT THIS TIME DUE TO THE LOW CERTAINTY OF MEASURABLE
FZRA. THERE APPEARS A BETTER CHANCE TONIGHT ACROSS THE CENTRAL
MTNS. HOWEVER...GIVEN THAT THIS AREA WILL BE ON THE WESTWARD
FRINGE OF MEASURABLE PRECIP...WILL WAIT FOR 12Z GUIDANCE TO GAUGE
THE NEED FOR AN ADVISORY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE TONIGHT
AND TUESDAY. BEST CHC OF MEASURABLE PRECIP SHOULD COME BTWN
00Z-06Z THIS EVENING WITH BENEFIT OF LG SCALE FORCING AHEAD OF
MID LVL SHORTWAVE. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE ICING CONCERNS OVER THE HIGHER TERRAIN OF
CENTRAL PA. HOWEVER...TEMPS WILL BE VERY MARGINAL WITH ICING MOST
LIKELY ON THE RIDGETOPS. ALSO...NOT ENTIRELY SURE MEASURABLE
PRECIP WILL EVEN REACH FAR ENOUGH WEST TO CREATE A CONCERN. WILL
THEREFORE CONTINUE TO MENTION THREAT OF ICY ROADS IN THE HWO AND
AWAIT 12Z GUIDANCE TO GET A BETTER HANDLE ON THIS EVENT.

ANY ICING THREAT SHOULD END BY DAYLIGHT TUESDAY...WHEN ALL PLUME
MEMBERS RISE ABV FREEZING. RAINFALL AMTS TUESDAY SHOULD BE VERY
LIGHT...WITH SHALLOW MOISTURE IN MDL SOUNDINGS IMPLYING OCNL
DRIZZLE RATHER THAN RAIN.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TRACKING WEST OF PA
WED/WED NITE. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM SHOULD SCOUR
OUT LINGERING SHALLOW COLD AIR EAST OF THE APPALACHIANS. LOW-LEVEL
TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR SEASONAL
VALUES...IMPLYING IT WILL BE A BALMY CHRISTMAS EVE FOR ALL.

ALL MED RANGE GUIDANCE TIMES THE TRAILING COLD FRONT THRU CENTRAL
PA WED NITE. A STRONG SOUTHERLY LL JET AND ASSOC PWAT ANOMALIES
ABOUT +3 SIGMA ABOVE NORMAL ARE PROGGED BY GEFS TO PASS THRU THE
AREA IN ADVANCE OF THE FRONT WED NITE. THIS STRONG SOUTHERLY
FLOW...HIGH PRECIPITABLE WATER AND SHARP CDFRONT ALL IMPLY A
FRONTAL RAIN EVENT WITH PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. HAVE ADDED CHC OF THUNDER BASED ON EXPECTED STRONG LG
SCALE FORCING IN ADVANCE OF UPPER TROF AND PRESENCE OF SOME MEAGER
MDL CAPES.

INTENSIFYING SFC LOW PASSING NORTH OF PA IS A FAVORABLE PATTERN
FOR STRONG WINDS ACROSS CENTRAL PA DURING THE COLD SEASON...SO STILL
MONITORING THE POTENTIAL OF STRONG WINDS COINCIDENT AND FOLLOWING
PASSAGE OF CDFRONT LATE WED NITE AND THURSDAY. WILL MENTION
POTENTIAL IN HWO.

COLDER AIR WORKING IN BEHIND COLD FRONT WILL LIKELY PRODUCE
OROGRAPHIC SNOW SHOWERS ACROSS THE ALLEGHENY PLATEAU ON CHRISTMAS
DAY. HOWEVER...AIR MASS NOT LOOKING PARTICULARLY COLD AND SFC
TEMPS LIKELY TO BE ABV FREEZING...LIMITING THE POTENTIAL OF
ACCUMS.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. ECENS OUTPUT SUGGESTS THIS
SHORTWAVE WILL LIFT NORTH OF PA NEXT WEEKEND...PUSHING A DYING COLD
FRONT INTO THE REGION.

&&

.AVIATION /10Z MONDAY THROUGH FRIDAY/...
THE PATTERN CONTINUES AS STRATOCU IS TRAPPED UNDER AN INVERSION
THROUGH MAINLY THE NORTH. THE REST OF THE REGION HAS CLEARED. THE
QUESTION OVERNIGHT IS THAT WHETHER ANY OF THE WEAK SOUTHERLY FLOW
ALLOWS FOR STRATOCU TO THICKEN. WITH LIGHT WINDS

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESPECIALLY MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
OVERNIGHT...THOUGH ANY MID CLOUDS WILL REDUCE FORMATION. EXPECT
MVFR POSSIBLE AT JST AND AOO BETWEEN 09 TO 12Z. THOUGH IFR SHOULD
CONTINUE AT BFD OVERNIGHT INTO TOMORROW.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 220649
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
149 AM EST MON DEC 22 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHWARD ALONG THE MID
ATLANTIC COAST ON MONDAY. A VIGOROUS STORM SYSTEM WILL PUSH A
COLD FRONT ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND EVEN A CHANCE FOR THUNDERSTORMS. WINDY AND
COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS ACROSS
THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
IR LOOP SHOWS MCLEAR SKIES ACROSS THE BULK OF CENTRAL PA AT 06Z.
INCREASINGLY MOIST SERLY FLOW WILL LIKELY CAUSE STRATUS TO WORK
INTO THE HIGH TERRAIN OF SOMERSET/BEDFORD COS TOWARD DAWN...AS
WELL AS THE THE HIGH TERRAIN OVR SULLIVAN/SCHUYLKILL COS. TEMPS ON
TRACK TO BOTTOM OUT IN THE L20S OVER MOST OF THE AREA.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM TUESDAY/...
920 PM UPDATE...
HAVE CONTINUED TO MENTION SOME ZR FOR THE LAURELS/SC MTNS AND UP
INTO THE ALLEGHENIES...AND ALONG THE NRN FRINGE OF THE VERY LIGHT
PRECIP EXPECTED TO MOVE IN FROM THE S LATE MON AFTN/EVENING. SREF
PROB OF ZR ARE VERY HIGH IN THE LAURELS AND ALLEGHENIES FOR THE
EVENING AND MON NIGHT. BUT THE PRECIP IS STILL UNCERTAIN ENOUGH TO
KEEP POPS IN THE HIGH-CHC RANGE...TAPERING OFF RATHER QUICKLY W OF
RTE 219. THEREFORE...STILL NO ADVY TO BE POSTED THIS EARLY/AT THIS
TIME HORIZON DUE TO THE LOW CERTAINTY OF OCCURRENCE OF PRECIP LET
ALONE ZR ACCRETIONS.

PREV..
INCREASING LLVL MOISTURE IS EXPECTED TO BRING SOME SPITTY/SPOTTY
NUISANCE TYPE PRECIPITATION ACROSS SOUTHERN AND SOUTHEASTERN AREAS
ON MONDAY...MAINLY AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING
MOISTURE NORTH OF THE MASON DIXON LINE AFTER 12Z...AN
OUTLIER...WHICH WOULD INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL
MARGINAL COLD AIR MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL
AND SOLUTION...AND FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT
PRECIP...WHICH WOULD STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE
ONSET. CONFIDENCE STILL TOO LOW ON THIS FOR ANY ADVISORY
CONSIDERATION AT THIS TIME/RANGE.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /07Z MONDAY THROUGH FRIDAY/...
THE PATTERN CONTINUES AS STRATOCU IS TRAPPED UNDER AN INVERSION
THROUGH MAINLY THE NORTH. THE REST OF THE REGION HAS CLEARED. THE
QUESTION OVERNIGHT IS THAT WHETHER ANY OF THE WEAK SOUTHERLY FLOW
ALLOWS FOR STRATOCU TO THICKEN. WITH LIGHT WINDS

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESPECIALLY MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
OVERNIGHT...THOUGH ANY MID CLOUDS WILL REDUCE FORMATION. EXPECT
MVFR POSSIBLE AT JST AND AOO BETWEEN 09 TO 12Z. THOUGH IFR SHOULD
CONTINUE AT BFD OVERNIGHT INTO TOMORROW.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...FITZGERALD
SHORT TERM...DANGELO
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 220649
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
149 AM EST MON DEC 22 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHWARD ALONG THE MID
ATLANTIC COAST ON MONDAY. A VIGOROUS STORM SYSTEM WILL PUSH A
COLD FRONT ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND EVEN A CHANCE FOR THUNDERSTORMS. WINDY AND
COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS ACROSS
THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
IR LOOP SHOWS MCLEAR SKIES ACROSS THE BULK OF CENTRAL PA AT 06Z.
INCREASINGLY MOIST SERLY FLOW WILL LIKELY CAUSE STRATUS TO WORK
INTO THE HIGH TERRAIN OF SOMERSET/BEDFORD COS TOWARD DAWN...AS
WELL AS THE THE HIGH TERRAIN OVR SULLIVAN/SCHUYLKILL COS. TEMPS ON
TRACK TO BOTTOM OUT IN THE L20S OVER MOST OF THE AREA.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH 6 PM TUESDAY/...
920 PM UPDATE...
HAVE CONTINUED TO MENTION SOME ZR FOR THE LAURELS/SC MTNS AND UP
INTO THE ALLEGHENIES...AND ALONG THE NRN FRINGE OF THE VERY LIGHT
PRECIP EXPECTED TO MOVE IN FROM THE S LATE MON AFTN/EVENING. SREF
PROB OF ZR ARE VERY HIGH IN THE LAURELS AND ALLEGHENIES FOR THE
EVENING AND MON NIGHT. BUT THE PRECIP IS STILL UNCERTAIN ENOUGH TO
KEEP POPS IN THE HIGH-CHC RANGE...TAPERING OFF RATHER QUICKLY W OF
RTE 219. THEREFORE...STILL NO ADVY TO BE POSTED THIS EARLY/AT THIS
TIME HORIZON DUE TO THE LOW CERTAINTY OF OCCURRENCE OF PRECIP LET
ALONE ZR ACCRETIONS.

PREV..
INCREASING LLVL MOISTURE IS EXPECTED TO BRING SOME SPITTY/SPOTTY
NUISANCE TYPE PRECIPITATION ACROSS SOUTHERN AND SOUTHEASTERN AREAS
ON MONDAY...MAINLY AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING
MOISTURE NORTH OF THE MASON DIXON LINE AFTER 12Z...AN
OUTLIER...WHICH WOULD INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL
MARGINAL COLD AIR MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL
AND SOLUTION...AND FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT
PRECIP...WHICH WOULD STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE
ONSET. CONFIDENCE STILL TOO LOW ON THIS FOR ANY ADVISORY
CONSIDERATION AT THIS TIME/RANGE.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /07Z MONDAY THROUGH FRIDAY/...
THE PATTERN CONTINUES AS STRATOCU IS TRAPPED UNDER AN INVERSION
THROUGH MAINLY THE NORTH. THE REST OF THE REGION HAS CLEARED. THE
QUESTION OVERNIGHT IS THAT WHETHER ANY OF THE WEAK SOUTHERLY FLOW
ALLOWS FOR STRATOCU TO THICKEN. WITH LIGHT WINDS

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESPECIALLY MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
OVERNIGHT...THOUGH ANY MID CLOUDS WILL REDUCE FORMATION. EXPECT
MVFR POSSIBLE AT JST AND AOO BETWEEN 09 TO 12Z. THOUGH IFR SHOULD
CONTINUE AT BFD OVERNIGHT INTO TOMORROW.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...FITZGERALD
SHORT TERM...DANGELO
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 220448
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1148 PM EST SUN DEC 21 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHWARD ALONG THE MID
ATLANTIC COAST ON MONDAY. A VIGOROUS STORM SYSTEM WILL PUSH A
COLD FRONT ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND EVEN A CHANCE FOR THUNDERSTORMS. WINDY AND
COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS ACROSS
THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
CLOUDS CONTINUE TO RECEDE NORTHWARD AT 02Z. JUST A COUPLE OF
SPOTS OF LOWER CLOUDS ON THE FOG CHANNEL /11-3.9 MICRON/ OF THE
SAT PICS OVER THE BLUE RIDGE IN VA. IN TIME...THE COMBINATION OF
INCREASING EASTERLY FLOW AROUND THE RETREATING HIGH PRESSURE OVER
NEW ENGLAND AND WEAK LOW PRESSURE DRIFTING NORTHWARD FROM THE
CAROLINAS ALONG THE MID ATLANTIC COAST WILL SHUNT WESTERN ATLANTIC
LOW LEVEL MOISTURE ONSHORE LATER TONIGHT. THIS ACTION IS EXPECTED
TO PRODUCE LOW CLOUDS AGAIN - ESP IN THE CENTRAL MTNS - BY MID
MORNING.

&&

.SHORT TERM /7 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
920 PM UPDATE...
HAVE CONTINUED TO MENTION SOME ZR FOR THE LAURELS/SC MTNS AND UP
INTO THE ALLEGHENIES...AND ALONG THE NRN FRINGE OF THE VERY LIGHT
PRECIP EXPECTED TO MOVE IN FROM THE S LATE MON AFTN/EVENING. SREF
PROB OF ZR ARE VERY HIGH IN THE LAURELS AND ALLEGHENIES FOR THE
EVENING AND MON NIGHT. BUT THE PRECIP IS STILL UNCERTAIN ENOUGH TO
KEEP POPS IN THE HIGH-CHC RANGE...TAPERING OFF RATHER QUICKLY W OF
RTE 219. THEREFORE...STILL NO ADVY TO BE POSTED THIS EARLY/AT THIS
TIME HORIZON DUE TO THE LOW CERTAINTY OF OCCURRENCE OF PRECIP LET
ALONE ZR ACCRETIONS.

PREV..
INCREASING LLVL MOISTURE IS EXPECTED TO BRING SOME SPITTY/SPOTTY
NUISANCE TYPE PRECIPITATION ACROSS SOUTHERN AND SOUTHEASTERN AREAS
ON MONDAY...MAINLY AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING
MOISTURE NORTH OF THE MASON DIXON LINE AFTER 12Z...AN
OUTLIER...WHICH WOULD INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL
MARGINAL COLD AIR MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL
AND SOLUTION...AND FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT
PRECIP...WHICH WOULD STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE
ONSET. CONFIDENCE STILL TOO LOW ON THIS FOR ANY ADVISORY
CONSIDERATION AT THIS TIME/RANGE.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /04Z MONDAY THROUGH FRIDAY/...
THE PATTERN CONTINUES AS STRATOCU IS TRAPPED UNDER AN INVERSION
THROUGH MAINLY THE NORTH. THE REST OF THE REGION HAS CLEARED. THE
QUESTION OVERNIGHT IS THAT WHETHER ANY OF THE WEAK SOUTHERLY FLOW
ALLOWS FOR STRATOCU TO THICKEN. WITH LIGHT WINDS

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESPECIALLY MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
OVERNIGHT...THOUGH ANY MID CLOUDS WILL REDUCE FORMATION. EXPECT
MVFR POSSIBLE AT JST AND AOO BETWEEN 09 TO 12Z. THOUGH IFR SHOULD
CONTINUE AT BFD OVERNIGHT INTO TOMORROW.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DANGELO/DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 220448
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1148 PM EST SUN DEC 21 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHWARD ALONG THE MID
ATLANTIC COAST ON MONDAY. A VIGOROUS STORM SYSTEM WILL PUSH A
COLD FRONT ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND EVEN A CHANCE FOR THUNDERSTORMS. WINDY AND
COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS ACROSS
THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
CLOUDS CONTINUE TO RECEDE NORTHWARD AT 02Z. JUST A COUPLE OF
SPOTS OF LOWER CLOUDS ON THE FOG CHANNEL /11-3.9 MICRON/ OF THE
SAT PICS OVER THE BLUE RIDGE IN VA. IN TIME...THE COMBINATION OF
INCREASING EASTERLY FLOW AROUND THE RETREATING HIGH PRESSURE OVER
NEW ENGLAND AND WEAK LOW PRESSURE DRIFTING NORTHWARD FROM THE
CAROLINAS ALONG THE MID ATLANTIC COAST WILL SHUNT WESTERN ATLANTIC
LOW LEVEL MOISTURE ONSHORE LATER TONIGHT. THIS ACTION IS EXPECTED
TO PRODUCE LOW CLOUDS AGAIN - ESP IN THE CENTRAL MTNS - BY MID
MORNING.

&&

.SHORT TERM /7 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
920 PM UPDATE...
HAVE CONTINUED TO MENTION SOME ZR FOR THE LAURELS/SC MTNS AND UP
INTO THE ALLEGHENIES...AND ALONG THE NRN FRINGE OF THE VERY LIGHT
PRECIP EXPECTED TO MOVE IN FROM THE S LATE MON AFTN/EVENING. SREF
PROB OF ZR ARE VERY HIGH IN THE LAURELS AND ALLEGHENIES FOR THE
EVENING AND MON NIGHT. BUT THE PRECIP IS STILL UNCERTAIN ENOUGH TO
KEEP POPS IN THE HIGH-CHC RANGE...TAPERING OFF RATHER QUICKLY W OF
RTE 219. THEREFORE...STILL NO ADVY TO BE POSTED THIS EARLY/AT THIS
TIME HORIZON DUE TO THE LOW CERTAINTY OF OCCURRENCE OF PRECIP LET
ALONE ZR ACCRETIONS.

PREV..
INCREASING LLVL MOISTURE IS EXPECTED TO BRING SOME SPITTY/SPOTTY
NUISANCE TYPE PRECIPITATION ACROSS SOUTHERN AND SOUTHEASTERN AREAS
ON MONDAY...MAINLY AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING
MOISTURE NORTH OF THE MASON DIXON LINE AFTER 12Z...AN
OUTLIER...WHICH WOULD INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL
MARGINAL COLD AIR MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL
AND SOLUTION...AND FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT
PRECIP...WHICH WOULD STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE
ONSET. CONFIDENCE STILL TOO LOW ON THIS FOR ANY ADVISORY
CONSIDERATION AT THIS TIME/RANGE.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /04Z MONDAY THROUGH FRIDAY/...
THE PATTERN CONTINUES AS STRATOCU IS TRAPPED UNDER AN INVERSION
THROUGH MAINLY THE NORTH. THE REST OF THE REGION HAS CLEARED. THE
QUESTION OVERNIGHT IS THAT WHETHER ANY OF THE WEAK SOUTHERLY FLOW
ALLOWS FOR STRATOCU TO THICKEN. WITH LIGHT WINDS

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESPECIALLY MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
OVERNIGHT...THOUGH ANY MID CLOUDS WILL REDUCE FORMATION. EXPECT
MVFR POSSIBLE AT JST AND AOO BETWEEN 09 TO 12Z. THOUGH IFR SHOULD
CONTINUE AT BFD OVERNIGHT INTO TOMORROW.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DANGELO/DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 220225
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
925 PM EST SUN DEC 21 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHWARD ALONG THE MID
ATLANTIC COAST ON MONDAY. A VIGOROUS STORM SYSTEM WILL PUSH A
COLD FRONT ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND EVEN A CHANCE FOR THUNDERSTORMS. WINDY AND
COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS ACROSS
THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
CLOUDS CONTINUE TO RECEDE NORTHWARD AT 02Z. JUST A COUPLE OF
SPOTS OF LOWER CLOUDS ON THE FOG CHANNEL /11-3.9 MICRON/ OF THE
SAT PICS OVER THE BLUE RIDGE IN VA. IN TIME...THE COMBINATION OF
INCREASING EASTERLY FLOW AROUND THE RETREATING HIGH PRESSURE OVER
NEW ENGLAND AND WEAK LOW PRESSURE DRIFTING NORTHWARD FROM THE
CAROLINAS ALONG THE MID ATLANTIC COAST WILL SHUNT WESTERN ATLANTIC
LOW LEVEL MOISTURE ONSHORE LATER TONIGHT. THIS ACTION IS EXPECTED
TO PRODUCE LOW CLOUDS AGAIN - ESP IN THE CENTRAL MTNS - BY MID
MORNING.

&&

.SHORT TERM /7 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
920 PM UPDATE...
HAVE CONTINUED TO MENTION SOME ZR FOR THE LAURELS/SC MTNS AND UP
INTO THE ALLEGHENIES...AND ALONG THE NRN FRINGE OF THE VERY LIGHT
PRECIP EXPECTED TO MOVE IN FROM THE S LATE MON AFTN/EVENING. SREF
PROB OF ZR ARE VERY HIGH IN THE LAURELS AND ALLEGHENIES FOR THE
EVENING AND MON NIGHT. BUT THE PRECIP IS STILL UNCERTAIN ENOUGH TO
KEEP POPS IN THE HIGH-CHC RANGE...TAPERING OFF RATHER QUICKLY W OF
RTE 219. THEREFORE...STILL NO ADVY TO BE POSTED THIS EARLY/AT THIS
TIME HORIZON DUE TO THE LOW CERTAINTY OF OCCURRANCE OF PRECIP LET
ALONE ZR ACCRETIONS.

PREV..
INCREASING LLVL MOISTURE IS EXPECTED TO BRING SOME SPITTY/SPOTTY
NUISANCE TYPE PRECIPITATION ACROSS SOUTHERN AND SOUTHEASTERN AREAS
ON MONDAY...MAINLY AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING
MOISTURE NORTH OF THE MASON DIXON LINE AFTER 12Z...AN
OUTLIER...WHICH WOULD INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL
MARGINAL COLD AIR MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL
AND SOLUTION...AND FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT
PRECIP...WHICH WOULD STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE
ONSET. CONFIDENCE STILL TOO LOW ON THIS FOR ANY ADVISORY
CONSIDERATION AT THIS TIME/RANGE.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THE PATTERN CONTINUES AS STRATOCU IS TRAPPED UNDER AN INVERSION
CENTRAL AND NORTH...WHILE AN AREA OF PARTIAL CLEARING EXTENDS FROM
SC MTNS TO LOWER SUSQ PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE
PREVALENT CENTRAL AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH
THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESPECIALLY MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
OVERNIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS
EAST REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DANGELO/DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 220225
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
925 PM EST SUN DEC 21 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHWARD ALONG THE MID
ATLANTIC COAST ON MONDAY. A VIGOROUS STORM SYSTEM WILL PUSH A
COLD FRONT ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND EVEN A CHANCE FOR THUNDERSTORMS. WINDY AND
COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS ACROSS
THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
CLOUDS CONTINUE TO RECEDE NORTHWARD AT 02Z. JUST A COUPLE OF
SPOTS OF LOWER CLOUDS ON THE FOG CHANNEL /11-3.9 MICRON/ OF THE
SAT PICS OVER THE BLUE RIDGE IN VA. IN TIME...THE COMBINATION OF
INCREASING EASTERLY FLOW AROUND THE RETREATING HIGH PRESSURE OVER
NEW ENGLAND AND WEAK LOW PRESSURE DRIFTING NORTHWARD FROM THE
CAROLINAS ALONG THE MID ATLANTIC COAST WILL SHUNT WESTERN ATLANTIC
LOW LEVEL MOISTURE ONSHORE LATER TONIGHT. THIS ACTION IS EXPECTED
TO PRODUCE LOW CLOUDS AGAIN - ESP IN THE CENTRAL MTNS - BY MID
MORNING.

&&

.SHORT TERM /7 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
920 PM UPDATE...
HAVE CONTINUED TO MENTION SOME ZR FOR THE LAURELS/SC MTNS AND UP
INTO THE ALLEGHENIES...AND ALONG THE NRN FRINGE OF THE VERY LIGHT
PRECIP EXPECTED TO MOVE IN FROM THE S LATE MON AFTN/EVENING. SREF
PROB OF ZR ARE VERY HIGH IN THE LAURELS AND ALLEGHENIES FOR THE
EVENING AND MON NIGHT. BUT THE PRECIP IS STILL UNCERTAIN ENOUGH TO
KEEP POPS IN THE HIGH-CHC RANGE...TAPERING OFF RATHER QUICKLY W OF
RTE 219. THEREFORE...STILL NO ADVY TO BE POSTED THIS EARLY/AT THIS
TIME HORIZON DUE TO THE LOW CERTAINTY OF OCCURRANCE OF PRECIP LET
ALONE ZR ACCRETIONS.

PREV..
INCREASING LLVL MOISTURE IS EXPECTED TO BRING SOME SPITTY/SPOTTY
NUISANCE TYPE PRECIPITATION ACROSS SOUTHERN AND SOUTHEASTERN AREAS
ON MONDAY...MAINLY AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING
MOISTURE NORTH OF THE MASON DIXON LINE AFTER 12Z...AN
OUTLIER...WHICH WOULD INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL
MARGINAL COLD AIR MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL
AND SOLUTION...AND FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT
PRECIP...WHICH WOULD STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE
ONSET. CONFIDENCE STILL TOO LOW ON THIS FOR ANY ADVISORY
CONSIDERATION AT THIS TIME/RANGE.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THE PATTERN CONTINUES AS STRATOCU IS TRAPPED UNDER AN INVERSION
CENTRAL AND NORTH...WHILE AN AREA OF PARTIAL CLEARING EXTENDS FROM
SC MTNS TO LOWER SUSQ PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE
PREVALENT CENTRAL AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH
THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESPECIALLY MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
OVERNIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS
EAST REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DANGELO/DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 220225
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
925 PM EST SUN DEC 21 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHWARD ALONG THE MID
ATLANTIC COAST ON MONDAY. A VIGOROUS STORM SYSTEM WILL PUSH A
COLD FRONT ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND EVEN A CHANCE FOR THUNDERSTORMS. WINDY AND
COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS ACROSS
THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
CLOUDS CONTINUE TO RECEDE NORTHWARD AT 02Z. JUST A COUPLE OF
SPOTS OF LOWER CLOUDS ON THE FOG CHANNEL /11-3.9 MICRON/ OF THE
SAT PICS OVER THE BLUE RIDGE IN VA. IN TIME...THE COMBINATION OF
INCREASING EASTERLY FLOW AROUND THE RETREATING HIGH PRESSURE OVER
NEW ENGLAND AND WEAK LOW PRESSURE DRIFTING NORTHWARD FROM THE
CAROLINAS ALONG THE MID ATLANTIC COAST WILL SHUNT WESTERN ATLANTIC
LOW LEVEL MOISTURE ONSHORE LATER TONIGHT. THIS ACTION IS EXPECTED
TO PRODUCE LOW CLOUDS AGAIN - ESP IN THE CENTRAL MTNS - BY MID
MORNING.

&&

.SHORT TERM /7 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
920 PM UPDATE...
HAVE CONTINUED TO MENTION SOME ZR FOR THE LAURELS/SC MTNS AND UP
INTO THE ALLEGHENIES...AND ALONG THE NRN FRINGE OF THE VERY LIGHT
PRECIP EXPECTED TO MOVE IN FROM THE S LATE MON AFTN/EVENING. SREF
PROB OF ZR ARE VERY HIGH IN THE LAURELS AND ALLEGHENIES FOR THE
EVENING AND MON NIGHT. BUT THE PRECIP IS STILL UNCERTAIN ENOUGH TO
KEEP POPS IN THE HIGH-CHC RANGE...TAPERING OFF RATHER QUICKLY W OF
RTE 219. THEREFORE...STILL NO ADVY TO BE POSTED THIS EARLY/AT THIS
TIME HORIZON DUE TO THE LOW CERTAINTY OF OCCURRANCE OF PRECIP LET
ALONE ZR ACCRETIONS.

PREV..
INCREASING LLVL MOISTURE IS EXPECTED TO BRING SOME SPITTY/SPOTTY
NUISANCE TYPE PRECIPITATION ACROSS SOUTHERN AND SOUTHEASTERN AREAS
ON MONDAY...MAINLY AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING
MOISTURE NORTH OF THE MASON DIXON LINE AFTER 12Z...AN
OUTLIER...WHICH WOULD INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL
MARGINAL COLD AIR MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL
AND SOLUTION...AND FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT
PRECIP...WHICH WOULD STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE
ONSET. CONFIDENCE STILL TOO LOW ON THIS FOR ANY ADVISORY
CONSIDERATION AT THIS TIME/RANGE.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THE PATTERN CONTINUES AS STRATOCU IS TRAPPED UNDER AN INVERSION
CENTRAL AND NORTH...WHILE AN AREA OF PARTIAL CLEARING EXTENDS FROM
SC MTNS TO LOWER SUSQ PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE
PREVALENT CENTRAL AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH
THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESPECIALLY MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
OVERNIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS
EAST REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DANGELO/DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 220225
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
925 PM EST SUN DEC 21 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHWARD ALONG THE MID
ATLANTIC COAST ON MONDAY. A VIGOROUS STORM SYSTEM WILL PUSH A
COLD FRONT ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND EVEN A CHANCE FOR THUNDERSTORMS. WINDY AND
COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS ACROSS
THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
CLOUDS CONTINUE TO RECEDE NORTHWARD AT 02Z. JUST A COUPLE OF
SPOTS OF LOWER CLOUDS ON THE FOG CHANNEL /11-3.9 MICRON/ OF THE
SAT PICS OVER THE BLUE RIDGE IN VA. IN TIME...THE COMBINATION OF
INCREASING EASTERLY FLOW AROUND THE RETREATING HIGH PRESSURE OVER
NEW ENGLAND AND WEAK LOW PRESSURE DRIFTING NORTHWARD FROM THE
CAROLINAS ALONG THE MID ATLANTIC COAST WILL SHUNT WESTERN ATLANTIC
LOW LEVEL MOISTURE ONSHORE LATER TONIGHT. THIS ACTION IS EXPECTED
TO PRODUCE LOW CLOUDS AGAIN - ESP IN THE CENTRAL MTNS - BY MID
MORNING.

&&

.SHORT TERM /7 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
920 PM UPDATE...
HAVE CONTINUED TO MENTION SOME ZR FOR THE LAURELS/SC MTNS AND UP
INTO THE ALLEGHENIES...AND ALONG THE NRN FRINGE OF THE VERY LIGHT
PRECIP EXPECTED TO MOVE IN FROM THE S LATE MON AFTN/EVENING. SREF
PROB OF ZR ARE VERY HIGH IN THE LAURELS AND ALLEGHENIES FOR THE
EVENING AND MON NIGHT. BUT THE PRECIP IS STILL UNCERTAIN ENOUGH TO
KEEP POPS IN THE HIGH-CHC RANGE...TAPERING OFF RATHER QUICKLY W OF
RTE 219. THEREFORE...STILL NO ADVY TO BE POSTED THIS EARLY/AT THIS
TIME HORIZON DUE TO THE LOW CERTAINTY OF OCCURRANCE OF PRECIP LET
ALONE ZR ACCRETIONS.

PREV..
INCREASING LLVL MOISTURE IS EXPECTED TO BRING SOME SPITTY/SPOTTY
NUISANCE TYPE PRECIPITATION ACROSS SOUTHERN AND SOUTHEASTERN AREAS
ON MONDAY...MAINLY AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING
MOISTURE NORTH OF THE MASON DIXON LINE AFTER 12Z...AN
OUTLIER...WHICH WOULD INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL
MARGINAL COLD AIR MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL
AND SOLUTION...AND FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT
PRECIP...WHICH WOULD STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE
ONSET. CONFIDENCE STILL TOO LOW ON THIS FOR ANY ADVISORY
CONSIDERATION AT THIS TIME/RANGE.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THE PATTERN CONTINUES AS STRATOCU IS TRAPPED UNDER AN INVERSION
CENTRAL AND NORTH...WHILE AN AREA OF PARTIAL CLEARING EXTENDS FROM
SC MTNS TO LOWER SUSQ PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE
PREVALENT CENTRAL AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH
THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESPECIALLY MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
OVERNIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS
EAST REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DANGELO/DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 220156
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
856 PM EST SUN DEC 21 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHWARD ALONG THE MID
ATLANTIC COAST ON MONDAY. A VIGOROUS STORM SYSTEM WILL PUSH A
COLD FRONT ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND EVEN A CHANCE FOR THUNDERSTORMS. WINDY AND
COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS ACROSS
THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CLOUDS AS DEPICTED BY 11-3.9UM IMAGERY ARE SHRINKING FROM THE
EDGES AND MAKING WHAT LOOKS TO BE THE SKYWARN LOGO OVER CENTRAL
PA - WITH MOST OF THE AREA CLEAR OF LOW CLOUDS. HOWEVER...THERE
ARE HIGH CLOUDS MOVING ACROSS THE SOUTH NOW.

IN TIME...THE COMBINATION OF INCREASING EASTERLY FLOW AROUND
THE RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK LOW
PRESSURE DRIFTING NORTHWARD FROM THE CAROLINAS ALONG THE MID
ATLANTIC COAST WILL SHUNT WESTERN ATLANTIC LOW LEVEL MOISTURE
ONSHORE LATER TONIGHT. THIS ACTION IS EXPECTED TO PRODUCE LOW
CLOUDS AGAIN - ESP IN THE CENTRAL MTNS - BY MID MORNING.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
INCREASING LLVL MOISTURE IS EXPECTED TO BRING SOME SPITTY/SPOTTY
NUISANCE TYPE PRECIPITATION ACROSS SOUTHERN AND SOUTHEASTERN AREAS
ON MONDAY...MAINLY AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING
MOISTURE NORTH OF THE MASON DIXON LINE AFTER 12Z...AN
OUTLIER...WHICH WOULD INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL
MARGINAL COLD AIR MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL
AND SOLUTION...AND FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT
PRECIP...WHICH WOULD STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE
ONSET. CONFIDENCE STILL TOO LOW ON THIS FOR ANY ADVISORY
CONSIDERATION AT THIS TIME/RANGE.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
THE PATTERN CONTINUES AS STRATOCU IS TRAPPED UNDER AN INVERSION
CENTRAL AND NORTH...WHILE AN AREA OF PARTIAL CLEARING EXTENDS FROM
SC MTNS TO LOWER SUSQ PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE
PREVALENT CENTRAL AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH
THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESPECIALLY MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
OVERNIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS
EAST REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 220156
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
856 PM EST SUN DEC 21 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHWARD ALONG THE MID
ATLANTIC COAST ON MONDAY. A VIGOROUS STORM SYSTEM WILL PUSH A
COLD FRONT ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND EVEN A CHANCE FOR THUNDERSTORMS. WINDY AND
COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS ACROSS
THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CLOUDS AS DEPICTED BY 11-3.9UM IMAGERY ARE SHRINKING FROM THE
EDGES AND MAKING WHAT LOOKS TO BE THE SKYWARN LOGO OVER CENTRAL
PA - WITH MOST OF THE AREA CLEAR OF LOW CLOUDS. HOWEVER...THERE
ARE HIGH CLOUDS MOVING ACROSS THE SOUTH NOW.

IN TIME...THE COMBINATION OF INCREASING EASTERLY FLOW AROUND
THE RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK LOW
PRESSURE DRIFTING NORTHWARD FROM THE CAROLINAS ALONG THE MID
ATLANTIC COAST WILL SHUNT WESTERN ATLANTIC LOW LEVEL MOISTURE
ONSHORE LATER TONIGHT. THIS ACTION IS EXPECTED TO PRODUCE LOW
CLOUDS AGAIN - ESP IN THE CENTRAL MTNS - BY MID MORNING.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
INCREASING LLVL MOISTURE IS EXPECTED TO BRING SOME SPITTY/SPOTTY
NUISANCE TYPE PRECIPITATION ACROSS SOUTHERN AND SOUTHEASTERN AREAS
ON MONDAY...MAINLY AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING
MOISTURE NORTH OF THE MASON DIXON LINE AFTER 12Z...AN
OUTLIER...WHICH WOULD INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL
MARGINAL COLD AIR MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL
AND SOLUTION...AND FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT
PRECIP...WHICH WOULD STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE
ONSET. CONFIDENCE STILL TOO LOW ON THIS FOR ANY ADVISORY
CONSIDERATION AT THIS TIME/RANGE.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
THE PATTERN CONTINUES AS STRATOCU IS TRAPPED UNDER AN INVERSION
CENTRAL AND NORTH...WHILE AN AREA OF PARTIAL CLEARING EXTENDS FROM
SC MTNS TO LOWER SUSQ PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE
PREVALENT CENTRAL AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH
THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESPECIALLY MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
OVERNIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS
EAST REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 220156
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
856 PM EST SUN DEC 21 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHWARD ALONG THE MID
ATLANTIC COAST ON MONDAY. A VIGOROUS STORM SYSTEM WILL PUSH A
COLD FRONT ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND EVEN A CHANCE FOR THUNDERSTORMS. WINDY AND
COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS ACROSS
THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CLOUDS AS DEPICTED BY 11-3.9UM IMAGERY ARE SHRINKING FROM THE
EDGES AND MAKING WHAT LOOKS TO BE THE SKYWARN LOGO OVER CENTRAL
PA - WITH MOST OF THE AREA CLEAR OF LOW CLOUDS. HOWEVER...THERE
ARE HIGH CLOUDS MOVING ACROSS THE SOUTH NOW.

IN TIME...THE COMBINATION OF INCREASING EASTERLY FLOW AROUND
THE RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK LOW
PRESSURE DRIFTING NORTHWARD FROM THE CAROLINAS ALONG THE MID
ATLANTIC COAST WILL SHUNT WESTERN ATLANTIC LOW LEVEL MOISTURE
ONSHORE LATER TONIGHT. THIS ACTION IS EXPECTED TO PRODUCE LOW
CLOUDS AGAIN - ESP IN THE CENTRAL MTNS - BY MID MORNING.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
INCREASING LLVL MOISTURE IS EXPECTED TO BRING SOME SPITTY/SPOTTY
NUISANCE TYPE PRECIPITATION ACROSS SOUTHERN AND SOUTHEASTERN AREAS
ON MONDAY...MAINLY AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING
MOISTURE NORTH OF THE MASON DIXON LINE AFTER 12Z...AN
OUTLIER...WHICH WOULD INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL
MARGINAL COLD AIR MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL
AND SOLUTION...AND FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT
PRECIP...WHICH WOULD STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE
ONSET. CONFIDENCE STILL TOO LOW ON THIS FOR ANY ADVISORY
CONSIDERATION AT THIS TIME/RANGE.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
THE PATTERN CONTINUES AS STRATOCU IS TRAPPED UNDER AN INVERSION
CENTRAL AND NORTH...WHILE AN AREA OF PARTIAL CLEARING EXTENDS FROM
SC MTNS TO LOWER SUSQ PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE
PREVALENT CENTRAL AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH
THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESPECIALLY MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
OVERNIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS
EAST REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 220156
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
856 PM EST SUN DEC 21 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHWARD ALONG THE MID
ATLANTIC COAST ON MONDAY. A VIGOROUS STORM SYSTEM WILL PUSH A
COLD FRONT ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND EVEN A CHANCE FOR THUNDERSTORMS. WINDY AND
COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS ACROSS
THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CLOUDS AS DEPICTED BY 11-3.9UM IMAGERY ARE SHRINKING FROM THE
EDGES AND MAKING WHAT LOOKS TO BE THE SKYWARN LOGO OVER CENTRAL
PA - WITH MOST OF THE AREA CLEAR OF LOW CLOUDS. HOWEVER...THERE
ARE HIGH CLOUDS MOVING ACROSS THE SOUTH NOW.

IN TIME...THE COMBINATION OF INCREASING EASTERLY FLOW AROUND
THE RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK LOW
PRESSURE DRIFTING NORTHWARD FROM THE CAROLINAS ALONG THE MID
ATLANTIC COAST WILL SHUNT WESTERN ATLANTIC LOW LEVEL MOISTURE
ONSHORE LATER TONIGHT. THIS ACTION IS EXPECTED TO PRODUCE LOW
CLOUDS AGAIN - ESP IN THE CENTRAL MTNS - BY MID MORNING.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
INCREASING LLVL MOISTURE IS EXPECTED TO BRING SOME SPITTY/SPOTTY
NUISANCE TYPE PRECIPITATION ACROSS SOUTHERN AND SOUTHEASTERN AREAS
ON MONDAY...MAINLY AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING
MOISTURE NORTH OF THE MASON DIXON LINE AFTER 12Z...AN
OUTLIER...WHICH WOULD INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL
MARGINAL COLD AIR MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL
AND SOLUTION...AND FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT
PRECIP...WHICH WOULD STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE
ONSET. CONFIDENCE STILL TOO LOW ON THIS FOR ANY ADVISORY
CONSIDERATION AT THIS TIME/RANGE.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
THE PATTERN CONTINUES AS STRATOCU IS TRAPPED UNDER AN INVERSION
CENTRAL AND NORTH...WHILE AN AREA OF PARTIAL CLEARING EXTENDS FROM
SC MTNS TO LOWER SUSQ PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE
PREVALENT CENTRAL AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH
THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESPECIALLY MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
OVERNIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS
EAST REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 212346
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
646 PM EST SUN DEC 21 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHWARD ALONG THE MID
ATLANTIC COAST ON MONDAY. A VIGOROUS STORM SYSTEM WILL PUSH A
COLD FRONT ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND EVEN A CHANCE FOR THUNDERSTORMS. WINDY AND
COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS ACROSS
THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CLOUDS AS DEPICTED BY 11-3.9UM IMAGERY ARE SHRINKING FROM THE
EDGES AND MAKING WHAT LOOKS TO BE THE SKYWARN LOGO OVER CENTRAL
PA - WITH MOST OF THE AREA CLEAR OF LOW CLOUDS. HOWEVER...THERE
ARE HIGH CLOUDS MOVING ACROSS THE SOUTH NOW.

IN TIME...THE COMBINATION OF INCREASING EASTERLY FLOW AROUND
THE RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK LOW
PRESSURE DRIFTING NORTHWARD FROM THE CAROLINAS ALONG THE MID
ATLANTIC COAST WILL SHUNT WESTERN ATLANTIC LOW LEVEL MOISTURE
ONSHORE LATER TONIGHT. THIS ACTION IS EXPECTED TO PRODUCE LOW
CLOUDS AGAIN - ESP IN THE CENTRAL MTNS - BY MID MORNING.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
INCREASING LLVL MOISTURE IS EXPECTED TO BRING SOME SPITTY/SPOTTY
NUISANCE TYPE PRECIPITATION ACROSS SOUTHERN AND SOUTHEASTERN AREAS
ON MONDAY...MAINLY AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING
MOISTURE NORTH OF THE MASON DIXON LINE AFTER 12Z...AN
OUTLIER...WHICH WOULD INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL
MARGINAL COLD AIR MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL
AND SOLUTION...AND FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT
PRECIP...WHICH WOULD STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE
ONSET. CONFIDENCE STILL TOO LOW ON THIS FOR ANY ADVISORY
CONSIDERATION AT THIS TIME/RANGE.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
STRATOCU TRAPPED UNDER INVERSION CENTRAL AND NORTH...WHILE AN
AREA OF PARTIAL CLEARING EXTENDS FROM SC MTNS TO LOWER SUSQ
PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE PREVALENT CENTRAL
AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESP MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
TONIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS EAST
REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/RXR





000
FXUS61 KCTP 212346
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
646 PM EST SUN DEC 21 2014

.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE NORTHWARD ALONG THE MID
ATLANTIC COAST ON MONDAY. A VIGOROUS STORM SYSTEM WILL PUSH A
COLD FRONT ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND EVEN A CHANCE FOR THUNDERSTORMS. WINDY AND
COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS ACROSS
THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CLOUDS AS DEPICTED BY 11-3.9UM IMAGERY ARE SHRINKING FROM THE
EDGES AND MAKING WHAT LOOKS TO BE THE SKYWARN LOGO OVER CENTRAL
PA - WITH MOST OF THE AREA CLEAR OF LOW CLOUDS. HOWEVER...THERE
ARE HIGH CLOUDS MOVING ACROSS THE SOUTH NOW.

IN TIME...THE COMBINATION OF INCREASING EASTERLY FLOW AROUND
THE RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK LOW
PRESSURE DRIFTING NORTHWARD FROM THE CAROLINAS ALONG THE MID
ATLANTIC COAST WILL SHUNT WESTERN ATLANTIC LOW LEVEL MOISTURE
ONSHORE LATER TONIGHT. THIS ACTION IS EXPECTED TO PRODUCE LOW
CLOUDS AGAIN - ESP IN THE CENTRAL MTNS - BY MID MORNING.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
INCREASING LLVL MOISTURE IS EXPECTED TO BRING SOME SPITTY/SPOTTY
NUISANCE TYPE PRECIPITATION ACROSS SOUTHERN AND SOUTHEASTERN AREAS
ON MONDAY...MAINLY AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING
MOISTURE NORTH OF THE MASON DIXON LINE AFTER 12Z...AN
OUTLIER...WHICH WOULD INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL
MARGINAL COLD AIR MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL
AND SOLUTION...AND FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT
PRECIP...WHICH WOULD STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE
ONSET. CONFIDENCE STILL TOO LOW ON THIS FOR ANY ADVISORY
CONSIDERATION AT THIS TIME/RANGE.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
STRATOCU TRAPPED UNDER INVERSION CENTRAL AND NORTH...WHILE AN
AREA OF PARTIAL CLEARING EXTENDS FROM SC MTNS TO LOWER SUSQ
PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE PREVALENT CENTRAL
AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESP MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
TONIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS EAST
REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/RXR




000
FXUS61 KCTP 212059
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
359 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER QUEBEC WILL SHIFT EASTWARD...DELIVERING AN
INCREASINGLY MOIST EASTERLY FLOW INTO THE REGION AS A WEAK LOW
PRESSURE SYSTEM TRACKS ALONG THE MID ATLANTIC COAST. PATCHY LIGHT
PRECIPITATION WILL DEVELOP ON MONDAY...PRIMARILY RAIN...BUT A FEW
SPOTS COULD SEE SOME PATCHY FREEZING RAIN IF IT DEVELOPS EASTERLY
ENOUGH IN THE DAY. MEANWHILE...A VIGOROUS STORM SYSTEM WILL SWEEP
ACROSS THE COMMONWEALTH ON CHRISTMAS EVE DAY BRINGING WIDESPREAD
SHOWERS AND A CHANCE FOR THUNDERSTORMS ON CHRISTMAS EVE. WINDY
AND COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS
ACROSS THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE THIN STRATUS CONTINUES TO THIN FURTHER ACROSS THE CENTRAL
MOUNTAINS...WITH VISIBLE IMAGERY SUGGESTING IT MAY GIVE WAY TO AN
HOUR OR TWO OF SUNSHINE IN SOME AREAS BEFORE SUNSET. THE FAR NORTH
MAY SEE SOME BRIGHTENING BUT BKN-OVC WILL REMAIN THERE LATE THIS
AFTERNOON AND EVENING. RETURN FLOW AROUND QUEBEC SFC HIGH SHOULD
CONTINUE THIS TREND THIS EVENING...AS RETURN FLOW SOURCE AREAS
SOUTH OF THE MASON DIXON LINE HAVE ALSO CLEARED FOR THE MEANTIME.

HOWEVER...IN TIME THE COMBINATION OF INCREASING EAST FLOW AROUND
RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK LOW PRESSURE
DRIFTING NORTHWARD FROM THE CAROLINAS ALONG THE MID ATLANTIC COAST
WILL SHUNT WESTERN ATLANTIC LOW LEVEL MOISTURE ONSHORE LATER
TONIGHT. AS PREVIOUSLY MENTIONED...INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...IS EXPECTED TO PRODUCE SOME PRECIPITATION...BUT CONSENSUS
STILL POINTS TO LATER ON MONDAY.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
AS MENTIONED IN THE NEAR TERM SECTION...INCREASING LLVL MOISTURE
IS EXPECTED TO BRING SOME SPITTY NUISANCE TYPE PRECIPITATION
ACROSS SOUTHERN AND SOUTHEASTERN AREAS ON MONDAY...MAINLY
AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING MOISTURE NORTH OF
THE MASON DIXON LINE AFTER 12Z...AN OUTLIER...WHICH WOULD
INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL MARGINAL COLD AIR
MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL AND SOLUTION...AND
FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT PRECIP...WHICH WOULD
STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE ONSET. CONFIDENCE
STILL TOO LOW ON THIS FOR ANY ADVISORY CONSIDERATION AT THIS TIME.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
STRATOCU TRAPPED UNDER INVERSION CENTRAL AND NORTH...WHILE AN
AREA OF PARTIAL CLEARING EXTENDS FROM SC MTNS TO LOWER SUSQ
PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE PREVALENT CENTRAL
AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESP MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
TONIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS EAST
REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/RXR




000
FXUS61 KCTP 212059
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
359 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER QUEBEC WILL SHIFT EASTWARD...DELIVERING AN
INCREASINGLY MOIST EASTERLY FLOW INTO THE REGION AS A WEAK LOW
PRESSURE SYSTEM TRACKS ALONG THE MID ATLANTIC COAST. PATCHY LIGHT
PRECIPITATION WILL DEVELOP ON MONDAY...PRIMARILY RAIN...BUT A FEW
SPOTS COULD SEE SOME PATCHY FREEZING RAIN IF IT DEVELOPS EASTERLY
ENOUGH IN THE DAY. MEANWHILE...A VIGOROUS STORM SYSTEM WILL SWEEP
ACROSS THE COMMONWEALTH ON CHRISTMAS EVE DAY BRINGING WIDESPREAD
SHOWERS AND A CHANCE FOR THUNDERSTORMS ON CHRISTMAS EVE. WINDY
AND COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS
ACROSS THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE THIN STRATUS CONTINUES TO THIN FURTHER ACROSS THE CENTRAL
MOUNTAINS...WITH VISIBLE IMAGERY SUGGESTING IT MAY GIVE WAY TO AN
HOUR OR TWO OF SUNSHINE IN SOME AREAS BEFORE SUNSET. THE FAR NORTH
MAY SEE SOME BRIGHTENING BUT BKN-OVC WILL REMAIN THERE LATE THIS
AFTERNOON AND EVENING. RETURN FLOW AROUND QUEBEC SFC HIGH SHOULD
CONTINUE THIS TREND THIS EVENING...AS RETURN FLOW SOURCE AREAS
SOUTH OF THE MASON DIXON LINE HAVE ALSO CLEARED FOR THE MEANTIME.

HOWEVER...IN TIME THE COMBINATION OF INCREASING EAST FLOW AROUND
RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK LOW PRESSURE
DRIFTING NORTHWARD FROM THE CAROLINAS ALONG THE MID ATLANTIC COAST
WILL SHUNT WESTERN ATLANTIC LOW LEVEL MOISTURE ONSHORE LATER
TONIGHT. AS PREVIOUSLY MENTIONED...INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...IS EXPECTED TO PRODUCE SOME PRECIPITATION...BUT CONSENSUS
STILL POINTS TO LATER ON MONDAY.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
AS MENTIONED IN THE NEAR TERM SECTION...INCREASING LLVL MOISTURE
IS EXPECTED TO BRING SOME SPITTY NUISANCE TYPE PRECIPITATION
ACROSS SOUTHERN AND SOUTHEASTERN AREAS ON MONDAY...MAINLY
AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING MOISTURE NORTH OF
THE MASON DIXON LINE AFTER 12Z...AN OUTLIER...WHICH WOULD
INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL MARGINAL COLD AIR
MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL AND SOLUTION...AND
FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT PRECIP...WHICH WOULD
STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE ONSET. CONFIDENCE
STILL TOO LOW ON THIS FOR ANY ADVISORY CONSIDERATION AT THIS TIME.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
FOR MONDAY NIGHT...DID NOT CHANGE A LOT. NAM MODEL LOOKS A
LITTLE WET...SO DID NOT UP POPS A LOT. WENT FOR A MIX OF
RAIN AND FREEZING RAIN...PCPN AMTS NOT MUCH MORE THAN .O1.
MORE LIKE A DRIZZLE. STILL THIRD PERIOD...TOO EARLY FOR AN
ADVISORY. THE MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC
OROGRAPHIC FORCING OF SHALLOW MOISTURE LYR WILL LINGER INTO
TUE MORNING...BUT SHOULD EDGE TO THE EAST DURING THE DAY. AFTER
HAVING LOWS IN THE 31-32 DEGREE RANGE...TEMPS SHOULD EDGE UP SOME
DURING THE DAY ON TUE.

DID NOT CHANGE A LOT FOR TUE...SOME RAIN DURING THE DAY
INTO TUE NIGHT...BUT NOT ALL THE TIME. LOW RATHER FAR TO
THE WEST FOR STRONG FLOW TO MOVE COLDER AIR OUT.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 24-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
SOME OF THE WARMER AIR INTO THE REGION ON WEDNESDAY...AS MANY
LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL ABOVE THEIR
SEASONAL VALUES. THIS IMPLIES WARMER TEMPS ON WEDNESDAY...AS THE
SHALLOW COLD AIR SCOURS OUT EAST OF THE MOUNTAINS.

NEW MODELS SLOW FRONT SOME...THUS DID UP POPS WED NIGHT AND
GO ALL RAIN.

COLDER AIR WORKS IN FOR CHRISTMAS...BUT SNOW SHOWERS WILL
BE MAINLY CONFINED TO THE WESTERN MOUNTAINS...AND NOT REAL
COLD.

MILDER AIR WORKS IN FOR FRIDAY ON SW FLOW.

COLDER AIR AGAIN FOR LATER IN THE WEEKEND...AS ANOTHER
COLD FRONT MOVES ACROSS THE AREA.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
STRATOCU TRAPPED UNDER INVERSION CENTRAL AND NORTH...WHILE AN
AREA OF PARTIAL CLEARING EXTENDS FROM SC MTNS TO LOWER SUSQ
PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE PREVALENT CENTRAL
AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESP MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
TONIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS EAST
REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/RXR





000
FXUS61 KCTP 211922
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
222 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER QUEBEC WILL SHIFT EASTWARD...DELIVERING AN
INCREASINGLY MOIST EASTERLY FLOW INTO THE REGION AS A WEAK LOW
PRESSURE SYSTEM TRACKS ALONG THE MID ATLANTIC COAST. PATCHY LIGHT
PRECIPITATION WILL DEVELOP ON MONDAY...PRIMARILY RAIN...BUT A FEW
SPOTS COULD SEE SOME PATCHY FREEZING RAIN IF IT DEVELOPS EASTERLY
ENOUGH IN THE DAY. MEANWHILE...A VIGOROUS STORM SYSTEM WILL SWEEP
ACROSS THE COMMONWEALTH ON CHRISTMAS EVE DAY BRINGING WIDESPREAD
SHOWERS AND A CHANCE FOR THUNDERSTORMS ON CHRISTMAS EVE. WINDY
AND COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS
ACROSS THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE THIN STRATUS CONTINUES TO THIN FURTHER ACROSS THE CENTRAL
MOUNTAINS...WITH VISIBLE IMAGERY SUGGESTING IT MAY GIVE WAY TO AN
HOUR OR TWO OF SUNSHINE IN SOME AREAS BEFORE SUNSET. THE FAR NORTH
MAY SEE SOME BRIGHTENING BUT BKN-OVC WILL REMAIN THERE LATE THIS
AFTERNOON AND EVENING. RETURN FLOW AROUND QUEBEC SFC HIGH SHOULD
CONTINUE THIS TREND THIS EVENING...AS RETURN FLOW SOURCE AREAS
SOUTH OF THE MASON DIXON LINE HAVE ALSO CLEARED FOR THE MEANTIME.

HOWEVER...IN TIME THE COMBINATION OF INCREASING EAST FLOW AROUND
RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK LOW PRESSURE
DRIFTING NORTHWARD FROM THE CAROLINAS ALONG THE MID ATLANTIC COAST
WILL SHUNT WESTERN ATLANTIC LOW LEVEL MOISTURE ONSHORE LATER
TONIGHT. AS PREVIOUSLY MENTIONED...INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...IS EXPECTED TO PRODUCE SOME PRECIPITATION...BUT CONSENSUS
STILL POINTS TO LATER ON MONDAY.

&&

.SHORT TERM /MONDAY/...
AS MENTIONED IN THE NEAR TERM SECTION...INCREASING LLVL MOISTURE
IS EXPECTED TO BRING SOME SPITTY NUISANCE TYPE PRECIPITATION
ACROSS SOUTHERN AND SOUTHEASTERN AREAS ON MONDAY...MAINLY
AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING MOISTURE NORTH OF
THE MASON DIXON LINE AFTER 12Z...AN OUTLIER...WHICH WOULD
INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL MARGINAL COLD AIR
MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL AND SOLUTION...AND
FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT PRECIP...WHICH WOULD
STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE ONSET. CONFIDENCE
STILL TOO LOW ON THIS FOR ANY ADVISORY CONSIDERATION AT THIS TIME.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE MON
NIGHT AND TUESDAY. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE SOME LINGERING ICING CONCERNS MON NIGHT
OVER THE HIGHER TERRAIN OF CENTRAL PA.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 23-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
WARM AIR INTO THE REGION TUESDAY AND WEDNESDAY. BY TUESDAY AND
WEDNESDAY MANY LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL
ABOVE THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER...ESP
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 4...BUT
GIVEN DIMINISHING SPREAD AMONGST MDL MEMBERS AND INCREASING
CONFIDENCE IN FRONTAL TIMING...WILL MAINTAIN CATEGORICAL POPS
WEDNESDAY/WED EVENING. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES MOST OF THE RAIN SHOULD FALL WITHIN 3-6 HOURS OF
THE FRONT.

THE COLD FRONT WILL LIKELY PUSH THRU THE REGION WED NIGHT...ACCOMPANIED
BY GUSTY WINDS AND LIKELY FOLLOWED BY OROGRAPHIC SNOW SHOWERS
ACROSS THE W MTNS CHRISTMAS MORNING.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
STRATOCU TRAPPED UNDER INVERSION CENTRAL AND NORTH...WHILE AN
AREA OF PARTIAL CLEARING EXTENDS FROM SC MTNS TO LOWER SUSQ
PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE PREVALENT CENTRAL
AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESP MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
TONIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS EAST
REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...GRUMM/FITZGERALD
AVIATION...DEVOIR/RXR





000
FXUS61 KCTP 211922
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
222 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER QUEBEC WILL SHIFT EASTWARD...DELIVERING AN
INCREASINGLY MOIST EASTERLY FLOW INTO THE REGION AS A WEAK LOW
PRESSURE SYSTEM TRACKS ALONG THE MID ATLANTIC COAST. PATCHY LIGHT
PRECIPITATION WILL DEVELOP ON MONDAY...PRIMARILY RAIN...BUT A FEW
SPOTS COULD SEE SOME PATCHY FREEZING RAIN IF IT DEVELOPS EASTERLY
ENOUGH IN THE DAY. MEANWHILE...A VIGOROUS STORM SYSTEM WILL SWEEP
ACROSS THE COMMONWEALTH ON CHRISTMAS EVE DAY BRINGING WIDESPREAD
SHOWERS AND A CHANCE FOR THUNDERSTORMS ON CHRISTMAS EVE. WINDY
AND COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS
ACROSS THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE THIN STRATUS CONTINUES TO THIN FURTHER ACROSS THE CENTRAL
MOUNTAINS...WITH VISIBLE IMAGERY SUGGESTING IT MAY GIVE WAY TO AN
HOUR OR TWO OF SUNSHINE IN SOME AREAS BEFORE SUNSET. THE FAR NORTH
MAY SEE SOME BRIGHTENING BUT BKN-OVC WILL REMAIN THERE LATE THIS
AFTERNOON AND EVENING. RETURN FLOW AROUND QUEBEC SFC HIGH SHOULD
CONTINUE THIS TREND THIS EVENING...AS RETURN FLOW SOURCE AREAS
SOUTH OF THE MASON DIXON LINE HAVE ALSO CLEARED FOR THE MEANTIME.

HOWEVER...IN TIME THE COMBINATION OF INCREASING EAST FLOW AROUND
RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK LOW PRESSURE
DRIFTING NORTHWARD FROM THE CAROLINAS ALONG THE MID ATLANTIC COAST
WILL SHUNT WESTERN ATLANTIC LOW LEVEL MOISTURE ONSHORE LATER
TONIGHT. AS PREVIOUSLY MENTIONED...INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...IS EXPECTED TO PRODUCE SOME PRECIPITATION...BUT CONSENSUS
STILL POINTS TO LATER ON MONDAY.

&&

.SHORT TERM /MONDAY/...
AS MENTIONED IN THE NEAR TERM SECTION...INCREASING LLVL MOISTURE
IS EXPECTED TO BRING SOME SPITTY NUISANCE TYPE PRECIPITATION
ACROSS SOUTHERN AND SOUTHEASTERN AREAS ON MONDAY...MAINLY
AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING MOISTURE NORTH OF
THE MASON DIXON LINE AFTER 12Z...AN OUTLIER...WHICH WOULD
INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL MARGINAL COLD AIR
MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL AND SOLUTION...AND
FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT PRECIP...WHICH WOULD
STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE ONSET. CONFIDENCE
STILL TOO LOW ON THIS FOR ANY ADVISORY CONSIDERATION AT THIS TIME.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE MON
NIGHT AND TUESDAY. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE SOME LINGERING ICING CONCERNS MON NIGHT
OVER THE HIGHER TERRAIN OF CENTRAL PA.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 23-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
WARM AIR INTO THE REGION TUESDAY AND WEDNESDAY. BY TUESDAY AND
WEDNESDAY MANY LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL
ABOVE THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER...ESP
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 4...BUT
GIVEN DIMINISHING SPREAD AMONGST MDL MEMBERS AND INCREASING
CONFIDENCE IN FRONTAL TIMING...WILL MAINTAIN CATEGORICAL POPS
WEDNESDAY/WED EVENING. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES MOST OF THE RAIN SHOULD FALL WITHIN 3-6 HOURS OF
THE FRONT.

THE COLD FRONT WILL LIKELY PUSH THRU THE REGION WED NIGHT...ACCOMPANIED
BY GUSTY WINDS AND LIKELY FOLLOWED BY OROGRAPHIC SNOW SHOWERS
ACROSS THE W MTNS CHRISTMAS MORNING.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
STRATOCU TRAPPED UNDER INVERSION CENTRAL AND NORTH...WHILE AN
AREA OF PARTIAL CLEARING EXTENDS FROM SC MTNS TO LOWER SUSQ
PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE PREVALENT CENTRAL
AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESP MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
TONIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS EAST
REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...GRUMM/FITZGERALD
AVIATION...DEVOIR/RXR




000
FXUS61 KCTP 211922
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
222 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER QUEBEC WILL SHIFT EASTWARD...DELIVERING AN
INCREASINGLY MOIST EASTERLY FLOW INTO THE REGION AS A WEAK LOW
PRESSURE SYSTEM TRACKS ALONG THE MID ATLANTIC COAST. PATCHY LIGHT
PRECIPITATION WILL DEVELOP ON MONDAY...PRIMARILY RAIN...BUT A FEW
SPOTS COULD SEE SOME PATCHY FREEZING RAIN IF IT DEVELOPS EASTERLY
ENOUGH IN THE DAY. MEANWHILE...A VIGOROUS STORM SYSTEM WILL SWEEP
ACROSS THE COMMONWEALTH ON CHRISTMAS EVE DAY BRINGING WIDESPREAD
SHOWERS AND A CHANCE FOR THUNDERSTORMS ON CHRISTMAS EVE. WINDY
AND COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS
ACROSS THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE THIN STRATUS CONTINUES TO THIN FURTHER ACROSS THE CENTRAL
MOUNTAINS...WITH VISIBLE IMAGERY SUGGESTING IT MAY GIVE WAY TO AN
HOUR OR TWO OF SUNSHINE IN SOME AREAS BEFORE SUNSET. THE FAR NORTH
MAY SEE SOME BRIGHTENING BUT BKN-OVC WILL REMAIN THERE LATE THIS
AFTERNOON AND EVENING. RETURN FLOW AROUND QUEBEC SFC HIGH SHOULD
CONTINUE THIS TREND THIS EVENING...AS RETURN FLOW SOURCE AREAS
SOUTH OF THE MASON DIXON LINE HAVE ALSO CLEARED FOR THE MEANTIME.

HOWEVER...IN TIME THE COMBINATION OF INCREASING EAST FLOW AROUND
RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK LOW PRESSURE
DRIFTING NORTHWARD FROM THE CAROLINAS ALONG THE MID ATLANTIC COAST
WILL SHUNT WESTERN ATLANTIC LOW LEVEL MOISTURE ONSHORE LATER
TONIGHT. AS PREVIOUSLY MENTIONED...INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...IS EXPECTED TO PRODUCE SOME PRECIPITATION...BUT CONSENSUS
STILL POINTS TO LATER ON MONDAY.

&&

.SHORT TERM /MONDAY/...
AS MENTIONED IN THE NEAR TERM SECTION...INCREASING LLVL MOISTURE
IS EXPECTED TO BRING SOME SPITTY NUISANCE TYPE PRECIPITATION
ACROSS SOUTHERN AND SOUTHEASTERN AREAS ON MONDAY...MAINLY
AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING MOISTURE NORTH OF
THE MASON DIXON LINE AFTER 12Z...AN OUTLIER...WHICH WOULD
INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL MARGINAL COLD AIR
MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL AND SOLUTION...AND
FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT PRECIP...WHICH WOULD
STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE ONSET. CONFIDENCE
STILL TOO LOW ON THIS FOR ANY ADVISORY CONSIDERATION AT THIS TIME.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE MON
NIGHT AND TUESDAY. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE SOME LINGERING ICING CONCERNS MON NIGHT
OVER THE HIGHER TERRAIN OF CENTRAL PA.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 23-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
WARM AIR INTO THE REGION TUESDAY AND WEDNESDAY. BY TUESDAY AND
WEDNESDAY MANY LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL
ABOVE THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER...ESP
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 4...BUT
GIVEN DIMINISHING SPREAD AMONGST MDL MEMBERS AND INCREASING
CONFIDENCE IN FRONTAL TIMING...WILL MAINTAIN CATEGORICAL POPS
WEDNESDAY/WED EVENING. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES MOST OF THE RAIN SHOULD FALL WITHIN 3-6 HOURS OF
THE FRONT.

THE COLD FRONT WILL LIKELY PUSH THRU THE REGION WED NIGHT...ACCOMPANIED
BY GUSTY WINDS AND LIKELY FOLLOWED BY OROGRAPHIC SNOW SHOWERS
ACROSS THE W MTNS CHRISTMAS MORNING.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
STRATOCU TRAPPED UNDER INVERSION CENTRAL AND NORTH...WHILE AN
AREA OF PARTIAL CLEARING EXTENDS FROM SC MTNS TO LOWER SUSQ
PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE PREVALENT CENTRAL
AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESP MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
TONIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS EAST
REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...GRUMM/FITZGERALD
AVIATION...DEVOIR/RXR





000
FXUS61 KCTP 211922
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
222 PM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER QUEBEC WILL SHIFT EASTWARD...DELIVERING AN
INCREASINGLY MOIST EASTERLY FLOW INTO THE REGION AS A WEAK LOW
PRESSURE SYSTEM TRACKS ALONG THE MID ATLANTIC COAST. PATCHY LIGHT
PRECIPITATION WILL DEVELOP ON MONDAY...PRIMARILY RAIN...BUT A FEW
SPOTS COULD SEE SOME PATCHY FREEZING RAIN IF IT DEVELOPS EASTERLY
ENOUGH IN THE DAY. MEANWHILE...A VIGOROUS STORM SYSTEM WILL SWEEP
ACROSS THE COMMONWEALTH ON CHRISTMAS EVE DAY BRINGING WIDESPREAD
SHOWERS AND A CHANCE FOR THUNDERSTORMS ON CHRISTMAS EVE. WINDY
AND COLDER CONDITIONS WILL FOLLOW WITH SCATTERED SNOW SHOWERS
ACROSS THE WEST AND NORTH FOR CHRISTMAS DAY. DRY AND SEASONABLE
CONDITIONS ARE EXPECTED FOR FRIDAY AND SATURDAY BEFORE MORE
UNSETTLED WEATHER ARRIVES FOR THE SECOND HALF OF THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE THIN STRATUS CONTINUES TO THIN FURTHER ACROSS THE CENTRAL
MOUNTAINS...WITH VISIBLE IMAGERY SUGGESTING IT MAY GIVE WAY TO AN
HOUR OR TWO OF SUNSHINE IN SOME AREAS BEFORE SUNSET. THE FAR NORTH
MAY SEE SOME BRIGHTENING BUT BKN-OVC WILL REMAIN THERE LATE THIS
AFTERNOON AND EVENING. RETURN FLOW AROUND QUEBEC SFC HIGH SHOULD
CONTINUE THIS TREND THIS EVENING...AS RETURN FLOW SOURCE AREAS
SOUTH OF THE MASON DIXON LINE HAVE ALSO CLEARED FOR THE MEANTIME.

HOWEVER...IN TIME THE COMBINATION OF INCREASING EAST FLOW AROUND
RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK LOW PRESSURE
DRIFTING NORTHWARD FROM THE CAROLINAS ALONG THE MID ATLANTIC COAST
WILL SHUNT WESTERN ATLANTIC LOW LEVEL MOISTURE ONSHORE LATER
TONIGHT. AS PREVIOUSLY MENTIONED...INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...IS EXPECTED TO PRODUCE SOME PRECIPITATION...BUT CONSENSUS
STILL POINTS TO LATER ON MONDAY.

&&

.SHORT TERM /MONDAY/...
AS MENTIONED IN THE NEAR TERM SECTION...INCREASING LLVL MOISTURE
IS EXPECTED TO BRING SOME SPITTY NUISANCE TYPE PRECIPITATION
ACROSS SOUTHERN AND SOUTHEASTERN AREAS ON MONDAY...MAINLY
AFTERNOON. NAM12 REMAINS AGGRESSIVE IN PUSHING MOISTURE NORTH OF
THE MASON DIXON LINE AFTER 12Z...AN OUTLIER...WHICH WOULD
INTRODUCE PRECIP TYPE ISSUES GIVEN RESIDUAL MARGINAL COLD AIR
MONDAY MORNING. CONTINUE TO DOWNPLAY THAT MODEL AND SOLUTION...AND
FAVOR A CONSENSUS LATER ARRIVAL OF LIGHT PRECIP...WHICH WOULD
STILL PRODUCE SOME PATCHY MIXED PRECIP AT THE ONSET. CONFIDENCE
STILL TOO LOW ON THIS FOR ANY ADVISORY CONSIDERATION AT THIS TIME.

DEPENDING UPON TIMING OF ARRIVAL...AREAS WHICH MAY BE MOST
SUSCEPTIBLE TO BRIEF -FZRA MON AFTERNOON WOULD BE OVER PARTS OF
THE CENTRAL AND SOUTH CENTRAL MOUNTAINS. STILL MONITORING THIS LOW
PROBABILITY EVENT AT THIS TIME...AND WILL MENTION LOW CHANCES IN
GRIDS/TEXT PRODUCTS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE MON
NIGHT AND TUESDAY. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE SOME LINGERING ICING CONCERNS MON NIGHT
OVER THE HIGHER TERRAIN OF CENTRAL PA.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 23-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
WARM AIR INTO THE REGION TUESDAY AND WEDNESDAY. BY TUESDAY AND
WEDNESDAY MANY LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL
ABOVE THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER...ESP
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 4...BUT
GIVEN DIMINISHING SPREAD AMONGST MDL MEMBERS AND INCREASING
CONFIDENCE IN FRONTAL TIMING...WILL MAINTAIN CATEGORICAL POPS
WEDNESDAY/WED EVENING. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES MOST OF THE RAIN SHOULD FALL WITHIN 3-6 HOURS OF
THE FRONT.

THE COLD FRONT WILL LIKELY PUSH THRU THE REGION WED NIGHT...ACCOMPANIED
BY GUSTY WINDS AND LIKELY FOLLOWED BY OROGRAPHIC SNOW SHOWERS
ACROSS THE W MTNS CHRISTMAS MORNING.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
STRATOCU TRAPPED UNDER INVERSION CENTRAL AND NORTH...WHILE AN
AREA OF PARTIAL CLEARING EXTENDS FROM SC MTNS TO LOWER SUSQ
PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE PREVALENT CENTRAL
AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH THE SOUTHERN TIER.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESP MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
TONIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS EAST
REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

FRI...FAIR AND MOSTLY VFR.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DEVOIR
NEAR TERM...DEVOIR
SHORT TERM...DEVOIR
LONG TERM...GRUMM/FITZGERALD
AVIATION...DEVOIR/RXR




000
FXUS61 KCTP 211552
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1052 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER PENNSYLVANIA WILL RETREAT INTO THE CANADIAN
MARITIMES EARLY NEXT WEEK...AS WEAK LOW PRESSURE LIFTS UP THE
EAST COAST. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BINOVC ACROSS THE SOUTH AND ESPECIALLY SOUTHEAST THIS MORNING IN
WAKE OF DEPARTING UPPER TROF. SUBSIDENCE AND STUBBORN STRATUS
REMAINS IN THE INVERSION ACROSS CENTRAL AND NORTHERN PA AND
DESPITE EROSION FROM THE SOUTH OVER MARYLAND PANHANDLE LATE THIS
MORNING...IT APPEARS THAT CLOUDS WILL WIN OUT FOR MOST AREAS THIS
AFTERNOON.

STAYED CLOSE TO CONSALL GUIDANCE WITH MAXES REACHING THE LOW 30S
OVER THE ALLEGHENIES TO THE UPPER 30S ACROSS THE LOWER SUSQ
VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
COMBINATION OF RETREATING HIGH PRES OVR NEW ENG AND WEAK LOW
LIFTING UP THE E COAST WILL SPREAD AN INCREASINGLY MOIST SERLY
FLOW INTO CENTRAL PA ON MONDAY. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA MONDAY
PM. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC POPS ACROSS THE
SOUTHERN COUNTIES MON AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME FZRA GIVEN COLD AIR DAMMING
SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY FLOW
HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST CHC OF LATE DAY -FZRA WOULD BE OVR THE LAUREL
HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE MON
NIGHT AND TUESDAY. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE SOME LINGERING ICING CONCERNS MON NIGHT
OVER THE HIGHER TERRAIN OF CENTRAL PA.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 23-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
WARM AIR INTO THE REGION TUESDAY AND WEDNESDAY. BY TUESDAY AND
WEDNESDAY MANY LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL
ABOVE THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER...ESP
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 4...BUT
GIVEN DIMINISHING SPREAD AMONGST MDL MEMBERS AND INCREASING
CONFIDENCE IN FRONTAL TIMING...WILL MAINTAIN CATEGORICAL POPS
WEDNESDAY/WED EVENING. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES MOST OF THE RAIN SHOULD FALL WITHIN 3-6 HOURS OF
THE FRONT.

THE COLD FRONT WILL LIKELY PUSH THRU THE REGION WED NIGHT...ACCOMPANIED
BY GUSTY WINDS AND LIKELY FOLLOWED BY OROGRAPHIC SNOW SHOWERS
ACROSS THE W MTNS CHRISTMAS MORNING.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
STRATOCU TRAPPED UNDER INVERSION CENTRAL AND NORTH...WHILE AN
AREA OF PARTIAL CLEARING EXTENDS FROM SC MTNS TO LOWER SUSQ
PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE PREVALENT CENTRAL
AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH THE SOUTHERN TIER.
SAT TRENDS INDICATE THE LAUREL HIGHLANDS MAY EVEN CLEAR OUT BY MID
AFTERNOON. HOWEVER...NOT CONFIDENT IN CLEARING ACROSS THE W MTNS
/INCLUDING KJST-KAOO/ WHERE MDL SOUNDINGS IMPLY LINGERING LOW
CLOUDS. WINDS TODAY WILL BE LIGHT.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESP MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
TONIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS EAST
REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM/FITZGERALD
AVIATION...RXR




000
FXUS61 KCTP 211552
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1052 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER PENNSYLVANIA WILL RETREAT INTO THE CANADIAN
MARITIMES EARLY NEXT WEEK...AS WEAK LOW PRESSURE LIFTS UP THE
EAST COAST. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BINOVC ACROSS THE SOUTH AND ESPECIALLY SOUTHEAST THIS MORNING IN
WAKE OF DEPARTING UPPER TROF. SUBSIDENCE AND STUBBORN STRATUS
REMAINS IN THE INVERSION ACROSS CENTRAL AND NORTHERN PA AND
DESPITE EROSION FROM THE SOUTH OVER MARYLAND PANHANDLE LATE THIS
MORNING...IT APPEARS THAT CLOUDS WILL WIN OUT FOR MOST AREAS THIS
AFTERNOON.

STAYED CLOSE TO CONSALL GUIDANCE WITH MAXES REACHING THE LOW 30S
OVER THE ALLEGHENIES TO THE UPPER 30S ACROSS THE LOWER SUSQ
VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
COMBINATION OF RETREATING HIGH PRES OVR NEW ENG AND WEAK LOW
LIFTING UP THE E COAST WILL SPREAD AN INCREASINGLY MOIST SERLY
FLOW INTO CENTRAL PA ON MONDAY. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA MONDAY
PM. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC POPS ACROSS THE
SOUTHERN COUNTIES MON AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME FZRA GIVEN COLD AIR DAMMING
SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY FLOW
HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST CHC OF LATE DAY -FZRA WOULD BE OVR THE LAUREL
HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE MON
NIGHT AND TUESDAY. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE SOME LINGERING ICING CONCERNS MON NIGHT
OVER THE HIGHER TERRAIN OF CENTRAL PA.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 23-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
WARM AIR INTO THE REGION TUESDAY AND WEDNESDAY. BY TUESDAY AND
WEDNESDAY MANY LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL
ABOVE THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER...ESP
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 4...BUT
GIVEN DIMINISHING SPREAD AMONGST MDL MEMBERS AND INCREASING
CONFIDENCE IN FRONTAL TIMING...WILL MAINTAIN CATEGORICAL POPS
WEDNESDAY/WED EVENING. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES MOST OF THE RAIN SHOULD FALL WITHIN 3-6 HOURS OF
THE FRONT.

THE COLD FRONT WILL LIKELY PUSH THRU THE REGION WED NIGHT...ACCOMPANIED
BY GUSTY WINDS AND LIKELY FOLLOWED BY OROGRAPHIC SNOW SHOWERS
ACROSS THE W MTNS CHRISTMAS MORNING.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
STRATOCU TRAPPED UNDER INVERSION CENTRAL AND NORTH...WHILE AN
AREA OF PARTIAL CLEARING EXTENDS FROM SC MTNS TO LOWER SUSQ
PROVIDING VFR CONDITIONS. MVFR CIGS WILL BE PREVALENT CENTRAL
AND NORTH...WHILE PARTIAL CLEARING FLIRTS WITH THE SOUTHERN TIER.
SAT TRENDS INDICATE THE LAUREL HIGHLANDS MAY EVEN CLEAR OUT BY MID
AFTERNOON. HOWEVER...NOT CONFIDENT IN CLEARING ACROSS THE W MTNS
/INCLUDING KJST-KAOO/ WHERE MDL SOUNDINGS IMPLY LINGERING LOW
CLOUDS. WINDS TODAY WILL BE LIGHT.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESP MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
TONIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS EAST
REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM/FITZGERALD
AVIATION...RXR





000
FXUS61 KCTP 211214
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
714 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER PENNSYLVANIA WILL RETREAT INTO THE CANADIAN
MARITIMES EARLY NEXT WEEK...AS WEAK LOW PRESSURE LIFTS UP THE
EAST COAST. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STRATOCU REMAINS TRAPPED BENEATH SHARP INVERSION EARLY THIS
MORNING ACROSS CENTRAL PA. DEEPER MOISTURE AND LIFT ASSOC WITH
PASSAGE OF SHORT WAVE COULD PRODUCE SEEDER-FEEDER EFFECT WITH
LOWER CLOUDS...RESULTING IN A FEW FLURRIES ACROSS THE NE COUNTIES BTWN
09Z-12Z.

FALLING INVERSION HGTS IN WAKE OF SHORTWAVE SHOULD CAUSE STRATOCU
TO BEGIN BREAKING UP TODAY EAST OF THE APPALACHIANS. HOWEVER...NOT
CONFIDENT IN CLEARING ACROSS THE W MTNS...WHERE MDL SOUNDINGS
IMPLY LINGERING LOW CLOUDS.

WENT CLOSE TO CONSALL GUIDANCE WITH MAXES REACHING THE LOW 30S
OVER THE ALLEGHENIES TO THE UPPER 30S ACROSS THE LOWER SUSQ
VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
COMBINATION OF RETREATING HIGH PRES OVR NEW ENG AND WEAK LOW
LIFTING UP THE E COAST WILL SPREAD AN INCREASINGLY MOIST SERLY
FLOW INTO CENTRAL PA ON MONDAY. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA MONDAY
PM. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC POPS ACROSS THE
SOUTHERN COUNTIES MON AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME FZRA GIVEN COLD AIR DAMMING
SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY FLOW
HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST CHC OF LATE DAY -FZRA WOULD BE OVR THE LAUREL
HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE MON
NIGHT AND TUESDAY. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE SOME LINGERING ICING CONCERNS MON NIGHT
OVER THE HIGHER TERRAIN OF CENTRAL PA.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 23-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
WARM AIR INTO THE REGION TUESDAY AND WEDNESDAY. BY TUESDAY AND
WEDNESDAY MANY LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL
ABOVE THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER...ESP
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 4...BUT
GIVEN DIMINISHING SPREAD AMONGST MDL MEMBERS AND INCREASING
CONFIDENCE IN FRONTAL TIMING...WILL MAINTAIN CATEGORICAL POPS
WEDNESDAY/WED EVENING. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES MOST OF THE RAIN SHOULD FALL WITHIN 3-6 HOURS OF
THE FRONT.

THE COLD FRONT WILL LIKELY PUSH THRU THE REGION WED NIGHT...ACCOMPANIED
BY GUSTY WINDS AND LIKELY FOLLOWED BY OROGRAPHIC SNOW SHOWERS
ACROSS THE W MTNS CHRISTMAS MORNING.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THOUGH IT SOUNDS LIKE A BROKEN RECORD...STRATOCU AGAIN REMAINS
TRAPPED BENEATH SHARP INVERSION EARLY THIS MORNING ACROSS CENTRAL
PA BRINGING GENERALLY MVFR CIGS TO CENTRAL AND NORTHERN MOUNTAINS
EVEN THOUGH SURFACE HIGH PRESSURE IS IN PLACE. THERE IS AN AREA
OF CLEARING OVER SC MTNS AND LOWER SUSQ WHICH IS PROVIDING VFR
CONDITIONS...WITH ADDITIONAL LOWER CIGS ALONG THE MASON/DIXON LINE
EXTENDING NORTHWARD INTO KJST AND ALSO EXTENDING SOUTHWARD INTO
THE MID ATLANTIC REGION.

FALLING INVERSION HEIGHTS IN THE WAKE OF AN EXITING SHORTWAVE
SHOULD ALLOW AREA OF CLEARING TO EXPAND INTO KUNV-KIPT LATER THIS
MORNING. HOWEVER...NOT CONFIDENT IN CLEARING ACROSS THE W MTNS
/INCLUDING KJST-KAOO/ WHERE MDL SOUNDINGS IMPLY LINGERING LOW
CLOUDS. WINDS TODAY WILL BE LIGHT.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESP MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
TONIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS EAST
REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM/FITZGERALD
AVIATION...RXR





000
FXUS61 KCTP 211214
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
714 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER PENNSYLVANIA WILL RETREAT INTO THE CANADIAN
MARITIMES EARLY NEXT WEEK...AS WEAK LOW PRESSURE LIFTS UP THE
EAST COAST. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STRATOCU REMAINS TRAPPED BENEATH SHARP INVERSION EARLY THIS
MORNING ACROSS CENTRAL PA. DEEPER MOISTURE AND LIFT ASSOC WITH
PASSAGE OF SHORT WAVE COULD PRODUCE SEEDER-FEEDER EFFECT WITH
LOWER CLOUDS...RESULTING IN A FEW FLURRIES ACROSS THE NE COUNTIES BTWN
09Z-12Z.

FALLING INVERSION HGTS IN WAKE OF SHORTWAVE SHOULD CAUSE STRATOCU
TO BEGIN BREAKING UP TODAY EAST OF THE APPALACHIANS. HOWEVER...NOT
CONFIDENT IN CLEARING ACROSS THE W MTNS...WHERE MDL SOUNDINGS
IMPLY LINGERING LOW CLOUDS.

WENT CLOSE TO CONSALL GUIDANCE WITH MAXES REACHING THE LOW 30S
OVER THE ALLEGHENIES TO THE UPPER 30S ACROSS THE LOWER SUSQ
VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
COMBINATION OF RETREATING HIGH PRES OVR NEW ENG AND WEAK LOW
LIFTING UP THE E COAST WILL SPREAD AN INCREASINGLY MOIST SERLY
FLOW INTO CENTRAL PA ON MONDAY. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA MONDAY
PM. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC POPS ACROSS THE
SOUTHERN COUNTIES MON AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME FZRA GIVEN COLD AIR DAMMING
SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY FLOW
HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST CHC OF LATE DAY -FZRA WOULD BE OVR THE LAUREL
HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE MON
NIGHT AND TUESDAY. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE SOME LINGERING ICING CONCERNS MON NIGHT
OVER THE HIGHER TERRAIN OF CENTRAL PA.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 23-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
WARM AIR INTO THE REGION TUESDAY AND WEDNESDAY. BY TUESDAY AND
WEDNESDAY MANY LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL
ABOVE THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER...ESP
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 4...BUT
GIVEN DIMINISHING SPREAD AMONGST MDL MEMBERS AND INCREASING
CONFIDENCE IN FRONTAL TIMING...WILL MAINTAIN CATEGORICAL POPS
WEDNESDAY/WED EVENING. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES MOST OF THE RAIN SHOULD FALL WITHIN 3-6 HOURS OF
THE FRONT.

THE COLD FRONT WILL LIKELY PUSH THRU THE REGION WED NIGHT...ACCOMPANIED
BY GUSTY WINDS AND LIKELY FOLLOWED BY OROGRAPHIC SNOW SHOWERS
ACROSS THE W MTNS CHRISTMAS MORNING.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THOUGH IT SOUNDS LIKE A BROKEN RECORD...STRATOCU AGAIN REMAINS
TRAPPED BENEATH SHARP INVERSION EARLY THIS MORNING ACROSS CENTRAL
PA BRINGING GENERALLY MVFR CIGS TO CENTRAL AND NORTHERN MOUNTAINS
EVEN THOUGH SURFACE HIGH PRESSURE IS IN PLACE. THERE IS AN AREA
OF CLEARING OVER SC MTNS AND LOWER SUSQ WHICH IS PROVIDING VFR
CONDITIONS...WITH ADDITIONAL LOWER CIGS ALONG THE MASON/DIXON LINE
EXTENDING NORTHWARD INTO KJST AND ALSO EXTENDING SOUTHWARD INTO
THE MID ATLANTIC REGION.

FALLING INVERSION HEIGHTS IN THE WAKE OF AN EXITING SHORTWAVE
SHOULD ALLOW AREA OF CLEARING TO EXPAND INTO KUNV-KIPT LATER THIS
MORNING. HOWEVER...NOT CONFIDENT IN CLEARING ACROSS THE W MTNS
/INCLUDING KJST-KAOO/ WHERE MDL SOUNDINGS IMPLY LINGERING LOW
CLOUDS. WINDS TODAY WILL BE LIGHT.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESP MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
TONIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS EAST
REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM/FITZGERALD
AVIATION...RXR





000
FXUS61 KCTP 211214
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
714 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER PENNSYLVANIA WILL RETREAT INTO THE CANADIAN
MARITIMES EARLY NEXT WEEK...AS WEAK LOW PRESSURE LIFTS UP THE
EAST COAST. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STRATOCU REMAINS TRAPPED BENEATH SHARP INVERSION EARLY THIS
MORNING ACROSS CENTRAL PA. DEEPER MOISTURE AND LIFT ASSOC WITH
PASSAGE OF SHORT WAVE COULD PRODUCE SEEDER-FEEDER EFFECT WITH
LOWER CLOUDS...RESULTING IN A FEW FLURRIES ACROSS THE NE COUNTIES BTWN
09Z-12Z.

FALLING INVERSION HGTS IN WAKE OF SHORTWAVE SHOULD CAUSE STRATOCU
TO BEGIN BREAKING UP TODAY EAST OF THE APPALACHIANS. HOWEVER...NOT
CONFIDENT IN CLEARING ACROSS THE W MTNS...WHERE MDL SOUNDINGS
IMPLY LINGERING LOW CLOUDS.

WENT CLOSE TO CONSALL GUIDANCE WITH MAXES REACHING THE LOW 30S
OVER THE ALLEGHENIES TO THE UPPER 30S ACROSS THE LOWER SUSQ
VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
COMBINATION OF RETREATING HIGH PRES OVR NEW ENG AND WEAK LOW
LIFTING UP THE E COAST WILL SPREAD AN INCREASINGLY MOIST SERLY
FLOW INTO CENTRAL PA ON MONDAY. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA MONDAY
PM. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC POPS ACROSS THE
SOUTHERN COUNTIES MON AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME FZRA GIVEN COLD AIR DAMMING
SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY FLOW
HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST CHC OF LATE DAY -FZRA WOULD BE OVR THE LAUREL
HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE MON
NIGHT AND TUESDAY. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE SOME LINGERING ICING CONCERNS MON NIGHT
OVER THE HIGHER TERRAIN OF CENTRAL PA.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 23-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
WARM AIR INTO THE REGION TUESDAY AND WEDNESDAY. BY TUESDAY AND
WEDNESDAY MANY LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL
ABOVE THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER...ESP
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 4...BUT
GIVEN DIMINISHING SPREAD AMONGST MDL MEMBERS AND INCREASING
CONFIDENCE IN FRONTAL TIMING...WILL MAINTAIN CATEGORICAL POPS
WEDNESDAY/WED EVENING. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES MOST OF THE RAIN SHOULD FALL WITHIN 3-6 HOURS OF
THE FRONT.

THE COLD FRONT WILL LIKELY PUSH THRU THE REGION WED NIGHT...ACCOMPANIED
BY GUSTY WINDS AND LIKELY FOLLOWED BY OROGRAPHIC SNOW SHOWERS
ACROSS THE W MTNS CHRISTMAS MORNING.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THOUGH IT SOUNDS LIKE A BROKEN RECORD...STRATOCU AGAIN REMAINS
TRAPPED BENEATH SHARP INVERSION EARLY THIS MORNING ACROSS CENTRAL
PA BRINGING GENERALLY MVFR CIGS TO CENTRAL AND NORTHERN MOUNTAINS
EVEN THOUGH SURFACE HIGH PRESSURE IS IN PLACE. THERE IS AN AREA
OF CLEARING OVER SC MTNS AND LOWER SUSQ WHICH IS PROVIDING VFR
CONDITIONS...WITH ADDITIONAL LOWER CIGS ALONG THE MASON/DIXON LINE
EXTENDING NORTHWARD INTO KJST AND ALSO EXTENDING SOUTHWARD INTO
THE MID ATLANTIC REGION.

FALLING INVERSION HEIGHTS IN THE WAKE OF AN EXITING SHORTWAVE
SHOULD ALLOW AREA OF CLEARING TO EXPAND INTO KUNV-KIPT LATER THIS
MORNING. HOWEVER...NOT CONFIDENT IN CLEARING ACROSS THE W MTNS
/INCLUDING KJST-KAOO/ WHERE MDL SOUNDINGS IMPLY LINGERING LOW
CLOUDS. WINDS TODAY WILL BE LIGHT.

COMBINATION OF RETREATING HIGH PRESSURE OVER NEW ENGLAND AND WEAK
LOW LIFTING UP THE EAST COAST WILL BRING A GRADUALLY INCREASING
MOIST SERLY FLOW INTO CENTRAL PA LATE TONIGHT AND ESP MONDAY.
ANTICIPATE THAT WE/LL SEE REDEVELOPMENT/REINFORCEMENT OF THE
STRATOCU DECK OVER THE SPINE OF THE APPALACHIANS /FROM KJST-KBFD/
TONIGHT...POSS SPREADING INTO CENTRAL MTNS...WITH MOST POINTS EAST
REMAINING VFR.

THE INCREASING MOISTURE...COMBINED WITH LG SCALE FORCING AHEAD OF
SHORTWAVE LIFTING OUT THE OHIO VALLEY...COULD SPREAD A BIT OF
LIGHT PRECIPITATION INTO SOUTHERN PA MONDAY PM.

OUTLOOK...

MON...CIG REDUCTIONS WEST. RESTRICTIONS DEVELOPING EAST. LIGHT
RAIN POSS SOUTH...FZRA POSS WESTERN HIGHER TERRAIN. BECOMING
BREEZY.

TUE...LOW CIGS WITH DRIZZLE/LIGHT RAIN LIKELY. BREEZY.

WED...PERIODS OF RAIN ALONG WITH WIDESPREAD REDUCTIONS. WINDY
WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN. LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM/FITZGERALD
AVIATION...RXR




000
FXUS61 KCTP 211145
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
645 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER PENNSYLVANIA WILL RETREAT INTO THE CANADIAN
MARITIMES EARLY NEXT WEEK...AS WEAK LOW PRESSURE LIFTS UP THE
EAST COAST. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WATER VAPOR LOOP SHOWS SHORTWAVE EXITING NORTHEAST PA AS OF 12Z. FALLING
INVERSION HGTS IN WAKE OF SHORTWAVE SHOULD CAUSE STRATOCU TO BEGIN
BREAKING UP TODAY EAST OF THE APPALACHIANS. HOWEVER...NOT CONFIDENT
IN CLEARING ACROSS THE W MTNS...WHERE MDL SOUNDINGS IMPLY LINGERING
LOW CLOUDS.

WENT CLOSE TO CONSALL GUIDANCE WITH MAXES REACHING THE LOW 30S
OVER THE ALLEGHENIES TO THE UPPER 30S ACROSS THE LOWER SUSQ
VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
COMBINATION OF RETREATING HIGH PRES OVR NEW ENG AND WEAK LOW
LIFTING UP THE E COAST WILL SPREAD AN INCREASINGLY MOIST SERLY
FLOW INTO CENTRAL PA ON MONDAY. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA MONDAY
PM. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC POPS ACROSS THE
SOUTHERN COUNTIES MON AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME FZRA GIVEN COLD AIR DAMMING
SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY FLOW
HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST CHC OF LATE DAY -FZRA WOULD BE OVR THE LAUREL
HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE MON
NIGHT AND TUESDAY. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE SOME LINGERING ICING CONCERNS MON NIGHT
OVER THE HIGHER TERRAIN OF CENTRAL PA.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 23-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
WARM AIR INTO THE REGION TUESDAY AND WEDNESDAY. BY TUESDAY AND
WEDNESDAY MANY LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL
ABOVE THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER...ESP
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 4...BUT
GIVEN DIMINISHING SPREAD AMONGST MDL MEMBERS AND INCREASING
CONFIDENCE IN FRONTAL TIMING...WILL MAINTAIN CATEGORICAL POPS
WEDNESDAY/WED EVENING. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES MOST OF THE RAIN SHOULD FALL WITHIN 3-6 HOURS OF
THE FRONT.

THE COLD FRONT WILL LIKELY PUSH THRU THE REGION WED NIGHT...ACCOMPANIED
BY GUSTY WINDS AND LIKELY FOLLOWED BY OROGRAPHIC SNOW SHOWERS
ACROSS THE W MTNS CHRISTMAS MORNING.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT...THOUGH LOW CLOUDS
SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A SHORTWAVE
WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID- LVL DECK
AS WELL. THAT MID DECK WILL DECREASE THE PROBABILITY FOR A THICKER
LOW DECK. THE SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH SW
FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO...JST AND UNV. IFR REMAINS POSSIBLE AT JST
BETWEEN 09 TO 13Z...AND BFD SHOULD BE IFR THROUGH MOST OF THE
PERIOD. MAINLY VFR THROUGH THE EASTERN TAF SITES.
 BFD SHOULD LIFT TO MVFR BY LATE TOMORROW MORNING...THOUGH MVFR
SHOULD REMAIN POSSIBLE AT BFD THROUGH TOMORROW...AND IFR RETURNING
AT BFD TOMORROW EVENING.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM/FITZGERALD
AVIATION...RXR




000
FXUS61 KCTP 211145
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
645 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER PENNSYLVANIA WILL RETREAT INTO THE CANADIAN
MARITIMES EARLY NEXT WEEK...AS WEAK LOW PRESSURE LIFTS UP THE
EAST COAST. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WATER VAPOR LOOP SHOWS SHORTWAVE EXITING NORTHEAST PA AS OF 12Z. FALLING
INVERSION HGTS IN WAKE OF SHORTWAVE SHOULD CAUSE STRATOCU TO BEGIN
BREAKING UP TODAY EAST OF THE APPALACHIANS. HOWEVER...NOT CONFIDENT
IN CLEARING ACROSS THE W MTNS...WHERE MDL SOUNDINGS IMPLY LINGERING
LOW CLOUDS.

WENT CLOSE TO CONSALL GUIDANCE WITH MAXES REACHING THE LOW 30S
OVER THE ALLEGHENIES TO THE UPPER 30S ACROSS THE LOWER SUSQ
VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
COMBINATION OF RETREATING HIGH PRES OVR NEW ENG AND WEAK LOW
LIFTING UP THE E COAST WILL SPREAD AN INCREASINGLY MOIST SERLY
FLOW INTO CENTRAL PA ON MONDAY. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA MONDAY
PM. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC POPS ACROSS THE
SOUTHERN COUNTIES MON AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME FZRA GIVEN COLD AIR DAMMING
SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY FLOW
HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST CHC OF LATE DAY -FZRA WOULD BE OVR THE LAUREL
HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE MON
NIGHT AND TUESDAY. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE SOME LINGERING ICING CONCERNS MON NIGHT
OVER THE HIGHER TERRAIN OF CENTRAL PA.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 23-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
WARM AIR INTO THE REGION TUESDAY AND WEDNESDAY. BY TUESDAY AND
WEDNESDAY MANY LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL
ABOVE THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER...ESP
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 4...BUT
GIVEN DIMINISHING SPREAD AMONGST MDL MEMBERS AND INCREASING
CONFIDENCE IN FRONTAL TIMING...WILL MAINTAIN CATEGORICAL POPS
WEDNESDAY/WED EVENING. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES MOST OF THE RAIN SHOULD FALL WITHIN 3-6 HOURS OF
THE FRONT.

THE COLD FRONT WILL LIKELY PUSH THRU THE REGION WED NIGHT...ACCOMPANIED
BY GUSTY WINDS AND LIKELY FOLLOWED BY OROGRAPHIC SNOW SHOWERS
ACROSS THE W MTNS CHRISTMAS MORNING.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT...THOUGH LOW CLOUDS
SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A SHORTWAVE
WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID- LVL DECK
AS WELL. THAT MID DECK WILL DECREASE THE PROBABILITY FOR A THICKER
LOW DECK. THE SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH SW
FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO...JST AND UNV. IFR REMAINS POSSIBLE AT JST
BETWEEN 09 TO 13Z...AND BFD SHOULD BE IFR THROUGH MOST OF THE
PERIOD. MAINLY VFR THROUGH THE EASTERN TAF SITES.
 BFD SHOULD LIFT TO MVFR BY LATE TOMORROW MORNING...THOUGH MVFR
SHOULD REMAIN POSSIBLE AT BFD THROUGH TOMORROW...AND IFR RETURNING
AT BFD TOMORROW EVENING.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM/FITZGERALD
AVIATION...RXR





000
FXUS61 KCTP 211045
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
545 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER PENNSYLVANIA WILL RETREAT INTO THE CANADIAN
MARITIMES EARLY NEXT WEEK...AS WEAK LOW PRESSURE LIFTS UP THE
EAST COAST. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STRATOCU REMAINS TRAPPED BENEATH SHARP INVERSION EARLY THIS
MORNING ACROSS CENTRAL PA. DEEPER MOISTURE AND LIFT ASSOC WITH
PASSAGE OF SHORT WAVE COULD PRODUCE SEEDER-FEEDER EFFECT WITH
LOWER CLOUDS...RESULTING IN A FEW FLURRIES ACROSS THE NE COUNTIES BTWN
09Z-12Z.

FALLING INVERSION HGTS IN WAKE OF SHORTWAVE SHOULD CAUSE STRATOCU
TO BEGIN BREAKING UP TODAY EAST OF THE APPALACHIANS. HOWEVER...NOT
CONFIDENT IN CLEARING ACROSS THE W MTNS...WHERE MDL SOUNDINGS
IMPLY LINGERING LOW CLOUDS.

WENT CLOSE TO CONSALL GUIDANCE WITH MAXES REACHING THE LOW 30S
OVER THE ALLEGHENIES TO THE UPPER 30S ACROSS THE LOWER SUSQ
VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
COMBINATION OF RETREATING HIGH PRES OVR NEW ENG AND WEAK LOW
LIFTING UP THE E COAST WILL SPREAD AN INCREASINGLY MOIST SERLY
FLOW INTO CENTRAL PA ON MONDAY. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA MONDAY
PM. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC POPS ACROSS THE
SOUTHERN COUNTIES MON AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME FZRA GIVEN COLD AIR DAMMING
SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY FLOW
HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST CHC OF LATE DAY -FZRA WOULD BE OVR THE LAUREL
HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE MON
NIGHT AND TUESDAY. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE SOME LINGERING ICING CONCERNS MON NIGHT
OVER THE HIGHER TERRAIN OF CENTRAL PA.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 23-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
WARM AIR INTO THE REGION TUESDAY AND WEDNESDAY. BY TUESDAY AND
WEDNESDAY MANY LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL
ABOVE THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER...ESP
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 4...BUT
GIVEN DIMINISHING SPREAD AMONGST MDL MEMBERS AND INCREASING
CONFIDENCE IN FRONTAL TIMING...WILL MAINTAIN CATEGORICAL POPS
WEDNESDAY/WED EVENING. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES MOST OF THE RAIN SHOULD FALL WITHIN 3-6 HOURS OF
THE FRONT.

THE COLD FRONT WILL LIKELY PUSH THRU THE REGION WED NIGHT...ACCOMPANIED
BY GUSTY WINDS AND LIKELY FOLLOWED BY OROGRAPHIC SNOW SHOWERS
ACROSS THE W MTNS CHRISTMAS MORNING.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT...THOUGH LOW CLOUDS
SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A SHORTWAVE
WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID- LVL DECK
AS WELL. THAT MID DECK WILL DECREASE THE PROBABILITY FOR A THICKER
LOW DECK. THE SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH SW
FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO...JST AND UNV. IFR REMAINS POSSIBLE AT JST
BETWEEN 09 TO 13Z...AND BFD SHOULD BE IFR THROUGH MOST OF THE
PERIOD. MAINLY VFR THROUGH THE EASTERN TAF SITES.
 BFD SHOULD LIFT TO MVFR BY LATE TOMORROW MORNING...THOUGH MVFR
SHOULD REMAIN POSSIBLE AT BFD THROUGH TOMORROW...AND IFR RETURNING
AT BFD TOMORROW EVENING.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM/FITZGERALD
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 211045
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
545 AM EST SUN DEC 21 2014

.SYNOPSIS...
HIGH PRESSURE OVER PENNSYLVANIA WILL RETREAT INTO THE CANADIAN
MARITIMES EARLY NEXT WEEK...AS WEAK LOW PRESSURE LIFTS UP THE
EAST COAST. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STRATOCU REMAINS TRAPPED BENEATH SHARP INVERSION EARLY THIS
MORNING ACROSS CENTRAL PA. DEEPER MOISTURE AND LIFT ASSOC WITH
PASSAGE OF SHORT WAVE COULD PRODUCE SEEDER-FEEDER EFFECT WITH
LOWER CLOUDS...RESULTING IN A FEW FLURRIES ACROSS THE NE COUNTIES BTWN
09Z-12Z.

FALLING INVERSION HGTS IN WAKE OF SHORTWAVE SHOULD CAUSE STRATOCU
TO BEGIN BREAKING UP TODAY EAST OF THE APPALACHIANS. HOWEVER...NOT
CONFIDENT IN CLEARING ACROSS THE W MTNS...WHERE MDL SOUNDINGS
IMPLY LINGERING LOW CLOUDS.

WENT CLOSE TO CONSALL GUIDANCE WITH MAXES REACHING THE LOW 30S
OVER THE ALLEGHENIES TO THE UPPER 30S ACROSS THE LOWER SUSQ
VALLEY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
COMBINATION OF RETREATING HIGH PRES OVR NEW ENG AND WEAK LOW
LIFTING UP THE E COAST WILL SPREAD AN INCREASINGLY MOIST SERLY
FLOW INTO CENTRAL PA ON MONDAY. THE INCREASING MOISTURE...COMBINED
WITH LG SCALE FORCING AHEAD OF SHORTWAVE LIFTING OUT THE OHIO
VALLEY...COULD SPREAD A BIT OF LIGHT RAIN INTO SOUTHERN PA MONDAY
PM. BLEND OF LATEST MDL GUIDANCE SUPPORTS CHC POPS ACROSS THE
SOUTHERN COUNTIES MON AFTN.

MAIN CONCERN WILL BE POTENTIAL OF SOME FZRA GIVEN COLD AIR DAMMING
SIGNATURE AND IMPLIED LOW-LEVEL AGEOSTROPHIC NORTHERLY FLOW
HOLDING LOW-LEVEL COLD AIR IN. OPER MDL SOUNDINGS AND ENS PTYPES
SUGGEST THE BEST CHC OF LATE DAY -FZRA WOULD BE OVR THE LAUREL
HIGHLANDS AND HIGHER TERRAIN OF THE SC MTNS.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MOIST SERLY FLOW OFF THE ATLANTIC AND ASSOC OROGRAPHIC FORCING OF SHALLOW
MOISTURE LYR WILL LIKELY PRODUCE PATCHY LGT RAIN/DRIZZLE MON
NIGHT AND TUESDAY. SFC TEMP FIELDS OF BOTH OPER AND ENSEMBLE DATA
SUGGEST THERE COULD BE SOME LINGERING ICING CONCERNS MON NIGHT
OVER THE HIGHER TERRAIN OF CENTRAL PA.

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM REMAINS THE
EVOLUTION OF DEEP TROUGH AND ASSOC SFC LOW TO OUR WEST 23-25
DECEMBER. STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING
WARM AIR INTO THE REGION TUESDAY AND WEDNESDAY. BY TUESDAY AND
WEDNESDAY MANY LOW-LEVEL TEMPERATURE AND MOISTURE FIELDS RISE WELL
ABOVE THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER...ESP
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 4...BUT
GIVEN DIMINISHING SPREAD AMONGST MDL MEMBERS AND INCREASING
CONFIDENCE IN FRONTAL TIMING...WILL MAINTAIN CATEGORICAL POPS
WEDNESDAY/WED EVENING. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES MOST OF THE RAIN SHOULD FALL WITHIN 3-6 HOURS OF
THE FRONT.

THE COLD FRONT WILL LIKELY PUSH THRU THE REGION WED NIGHT...ACCOMPANIED
BY GUSTY WINDS AND LIKELY FOLLOWED BY OROGRAPHIC SNOW SHOWERS
ACROSS THE W MTNS CHRISTMAS MORNING.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT...THOUGH LOW CLOUDS
SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A SHORTWAVE
WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID- LVL DECK
AS WELL. THAT MID DECK WILL DECREASE THE PROBABILITY FOR A THICKER
LOW DECK. THE SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH SW
FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO...JST AND UNV. IFR REMAINS POSSIBLE AT JST
BETWEEN 09 TO 13Z...AND BFD SHOULD BE IFR THROUGH MOST OF THE
PERIOD. MAINLY VFR THROUGH THE EASTERN TAF SITES.
 BFD SHOULD LIFT TO MVFR BY LATE TOMORROW MORNING...THOUGH MVFR
SHOULD REMAIN POSSIBLE AT BFD THROUGH TOMORROW...AND IFR RETURNING
AT BFD TOMORROW EVENING.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM/FITZGERALD
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 210641
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
141 AM EST SUN DEC 21 2014

.SYNOPSIS...
AN AMPLIFYING UPPER RIDGE WILL MOVE INTO THE REGION ON
SUNDAY. TEMPERATURES WILL THEN BECOME JUST SLIGHTLY MILDER BUT
UNSETTLED CONDITIONS WILL BEGIN ON MONDAY NIGHT AND PREVAIL
THROUGH MID WEEK. A VIGOROUS STORM SYSTEM WILL SWEEP ACROSS THE
COMMONWEALTH ON CHRISTMAS EVE BRINGING WIDESPREAD SHOWERS AND A
CHANCE FOR THUNDERSTORMS. WINDY AND COLDER CONDITIONS WILL FOLLOW
WITH SCATTERED SNOW SHOWERS ACROSS THE WEST AND NORTH FOR
CHRISTMAS DAY. MILDER CONDITIONS WILL RETURN LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 8 AM THIS MORNING/...
STRATOCU REMAINS TRAPPED BENEATH SHARP INVERSION EARLY THIS
MORNING ACROSS CENTRAL PA. DEEPER MOISTURE AND LIFT ASSOC WITH
PASSAGE OF SHORT WAVE COULD PRODUCE SEEDER-FEEDER EFFECT WITH
LOWER CLOUDS...RESULTING IN A FEW FLURRIES ACROSS THE N MTNS BTWN
06Z-09Z. UNDER OVERCAST SKIES...TEMPS NOT EXPECTED TO FALL MUCH
MORE TONIGHT...BOTTOMING OUT IN THE LOW TO MID 20S MOST PLACES.

&&

.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM MONDAY/...
DEEP LAYER DRYING BEHIND A DEPARTING 5H WAVE AND UPPER LEVEL
RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF NOT ALL OF
CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS PLAGUED US FOR
MORE THAN A WEEK WILL HAVE A CHANCE TO MIX OUT...BUT TRANSITORY
SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW PROCESS OVER THE
NORTH.

WENT CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE LOW
30S OVER THE ALLEGHENIES TO THE UPPER 30S ACROSS THE LOWER SUSQ
VALLEY.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT...THOUGH LOW CLOUDS
SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A SHORTWAVE
WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID- LVL DECK
AS WELL. THAT MID DECK WILL DECREASE THE PROBABILITY FOR A THICKER
LOW DECK. THE SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH SW
FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO...JST AND UNV. IFR REMAINS POSSIBLE AT JST
BETWEEN 09 TO 13Z...AND BFD SHOULD BE IFR THROUGH MOST OF THE
PERIOD. MAINLY VFR THROUGH THE EASTERN TAF SITES.
 BFD SHOULD LIFT TO MVFR BY LATE TOMORROW MORNING...THOUGH MVFR
SHOULD REMAIN POSSIBLE AT BFD THROUGH TOMORROW...AND IFR RETURNING
AT BFD TOMORROW EVENING.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR
LONG TERM...GRUMM
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 210641
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
141 AM EST SUN DEC 21 2014

.SYNOPSIS...
AN AMPLIFYING UPPER RIDGE WILL MOVE INTO THE REGION ON
SUNDAY. TEMPERATURES WILL THEN BECOME JUST SLIGHTLY MILDER BUT
UNSETTLED CONDITIONS WILL BEGIN ON MONDAY NIGHT AND PREVAIL
THROUGH MID WEEK. A VIGOROUS STORM SYSTEM WILL SWEEP ACROSS THE
COMMONWEALTH ON CHRISTMAS EVE BRINGING WIDESPREAD SHOWERS AND A
CHANCE FOR THUNDERSTORMS. WINDY AND COLDER CONDITIONS WILL FOLLOW
WITH SCATTERED SNOW SHOWERS ACROSS THE WEST AND NORTH FOR
CHRISTMAS DAY. MILDER CONDITIONS WILL RETURN LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 8 AM THIS MORNING/...
STRATOCU REMAINS TRAPPED BENEATH SHARP INVERSION EARLY THIS
MORNING ACROSS CENTRAL PA. DEEPER MOISTURE AND LIFT ASSOC WITH
PASSAGE OF SHORT WAVE COULD PRODUCE SEEDER-FEEDER EFFECT WITH
LOWER CLOUDS...RESULTING IN A FEW FLURRIES ACROSS THE N MTNS BTWN
06Z-09Z. UNDER OVERCAST SKIES...TEMPS NOT EXPECTED TO FALL MUCH
MORE TONIGHT...BOTTOMING OUT IN THE LOW TO MID 20S MOST PLACES.

&&

.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM MONDAY/...
DEEP LAYER DRYING BEHIND A DEPARTING 5H WAVE AND UPPER LEVEL
RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF NOT ALL OF
CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS PLAGUED US FOR
MORE THAN A WEEK WILL HAVE A CHANCE TO MIX OUT...BUT TRANSITORY
SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW PROCESS OVER THE
NORTH.

WENT CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE LOW
30S OVER THE ALLEGHENIES TO THE UPPER 30S ACROSS THE LOWER SUSQ
VALLEY.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT...THOUGH LOW CLOUDS
SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A SHORTWAVE
WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID- LVL DECK
AS WELL. THAT MID DECK WILL DECREASE THE PROBABILITY FOR A THICKER
LOW DECK. THE SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH SW
FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO...JST AND UNV. IFR REMAINS POSSIBLE AT JST
BETWEEN 09 TO 13Z...AND BFD SHOULD BE IFR THROUGH MOST OF THE
PERIOD. MAINLY VFR THROUGH THE EASTERN TAF SITES.
 BFD SHOULD LIFT TO MVFR BY LATE TOMORROW MORNING...THOUGH MVFR
SHOULD REMAIN POSSIBLE AT BFD THROUGH TOMORROW...AND IFR RETURNING
AT BFD TOMORROW EVENING.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR
LONG TERM...GRUMM
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 210641
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
141 AM EST SUN DEC 21 2014

.SYNOPSIS...
AN AMPLIFYING UPPER RIDGE WILL MOVE INTO THE REGION ON
SUNDAY. TEMPERATURES WILL THEN BECOME JUST SLIGHTLY MILDER BUT
UNSETTLED CONDITIONS WILL BEGIN ON MONDAY NIGHT AND PREVAIL
THROUGH MID WEEK. A VIGOROUS STORM SYSTEM WILL SWEEP ACROSS THE
COMMONWEALTH ON CHRISTMAS EVE BRINGING WIDESPREAD SHOWERS AND A
CHANCE FOR THUNDERSTORMS. WINDY AND COLDER CONDITIONS WILL FOLLOW
WITH SCATTERED SNOW SHOWERS ACROSS THE WEST AND NORTH FOR
CHRISTMAS DAY. MILDER CONDITIONS WILL RETURN LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 8 AM THIS MORNING/...
STRATOCU REMAINS TRAPPED BENEATH SHARP INVERSION EARLY THIS
MORNING ACROSS CENTRAL PA. DEEPER MOISTURE AND LIFT ASSOC WITH
PASSAGE OF SHORT WAVE COULD PRODUCE SEEDER-FEEDER EFFECT WITH
LOWER CLOUDS...RESULTING IN A FEW FLURRIES ACROSS THE N MTNS BTWN
06Z-09Z. UNDER OVERCAST SKIES...TEMPS NOT EXPECTED TO FALL MUCH
MORE TONIGHT...BOTTOMING OUT IN THE LOW TO MID 20S MOST PLACES.

&&

.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM MONDAY/...
DEEP LAYER DRYING BEHIND A DEPARTING 5H WAVE AND UPPER LEVEL
RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF NOT ALL OF
CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS PLAGUED US FOR
MORE THAN A WEEK WILL HAVE A CHANCE TO MIX OUT...BUT TRANSITORY
SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW PROCESS OVER THE
NORTH.

WENT CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE LOW
30S OVER THE ALLEGHENIES TO THE UPPER 30S ACROSS THE LOWER SUSQ
VALLEY.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT...THOUGH LOW CLOUDS
SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A SHORTWAVE
WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID- LVL DECK
AS WELL. THAT MID DECK WILL DECREASE THE PROBABILITY FOR A THICKER
LOW DECK. THE SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH SW
FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO...JST AND UNV. IFR REMAINS POSSIBLE AT JST
BETWEEN 09 TO 13Z...AND BFD SHOULD BE IFR THROUGH MOST OF THE
PERIOD. MAINLY VFR THROUGH THE EASTERN TAF SITES.
 BFD SHOULD LIFT TO MVFR BY LATE TOMORROW MORNING...THOUGH MVFR
SHOULD REMAIN POSSIBLE AT BFD THROUGH TOMORROW...AND IFR RETURNING
AT BFD TOMORROW EVENING.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR
LONG TERM...GRUMM
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 210641
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
141 AM EST SUN DEC 21 2014

.SYNOPSIS...
AN AMPLIFYING UPPER RIDGE WILL MOVE INTO THE REGION ON
SUNDAY. TEMPERATURES WILL THEN BECOME JUST SLIGHTLY MILDER BUT
UNSETTLED CONDITIONS WILL BEGIN ON MONDAY NIGHT AND PREVAIL
THROUGH MID WEEK. A VIGOROUS STORM SYSTEM WILL SWEEP ACROSS THE
COMMONWEALTH ON CHRISTMAS EVE BRINGING WIDESPREAD SHOWERS AND A
CHANCE FOR THUNDERSTORMS. WINDY AND COLDER CONDITIONS WILL FOLLOW
WITH SCATTERED SNOW SHOWERS ACROSS THE WEST AND NORTH FOR
CHRISTMAS DAY. MILDER CONDITIONS WILL RETURN LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 8 AM THIS MORNING/...
STRATOCU REMAINS TRAPPED BENEATH SHARP INVERSION EARLY THIS
MORNING ACROSS CENTRAL PA. DEEPER MOISTURE AND LIFT ASSOC WITH
PASSAGE OF SHORT WAVE COULD PRODUCE SEEDER-FEEDER EFFECT WITH
LOWER CLOUDS...RESULTING IN A FEW FLURRIES ACROSS THE N MTNS BTWN
06Z-09Z. UNDER OVERCAST SKIES...TEMPS NOT EXPECTED TO FALL MUCH
MORE TONIGHT...BOTTOMING OUT IN THE LOW TO MID 20S MOST PLACES.

&&

.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM MONDAY/...
DEEP LAYER DRYING BEHIND A DEPARTING 5H WAVE AND UPPER LEVEL
RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF NOT ALL OF
CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS PLAGUED US FOR
MORE THAN A WEEK WILL HAVE A CHANCE TO MIX OUT...BUT TRANSITORY
SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW PROCESS OVER THE
NORTH.

WENT CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE LOW
30S OVER THE ALLEGHENIES TO THE UPPER 30S ACROSS THE LOWER SUSQ
VALLEY.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT...THOUGH LOW CLOUDS
SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A SHORTWAVE
WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID- LVL DECK
AS WELL. THAT MID DECK WILL DECREASE THE PROBABILITY FOR A THICKER
LOW DECK. THE SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH SW
FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO...JST AND UNV. IFR REMAINS POSSIBLE AT JST
BETWEEN 09 TO 13Z...AND BFD SHOULD BE IFR THROUGH MOST OF THE
PERIOD. MAINLY VFR THROUGH THE EASTERN TAF SITES.
 BFD SHOULD LIFT TO MVFR BY LATE TOMORROW MORNING...THOUGH MVFR
SHOULD REMAIN POSSIBLE AT BFD THROUGH TOMORROW...AND IFR RETURNING
AT BFD TOMORROW EVENING.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...FITZGERALD
SHORT TERM...DEVOIR
LONG TERM...GRUMM
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 210446
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1146 PM EST SAT DEC 20 2014

.SYNOPSIS...
AN AMPLIFYING UPPER RIDGE WILL MOVE INTO THE REGION ON
SUNDAY. TEMPERATURES WILL THEN BECOME JUST SLIGHTLY MILDER BUT
UNSETTLED CONDITIONS WILL BEGIN ON MONDAY NIGHT AND PREVAIL
THROUGH MID WEEK. A VIGOROUS STORM SYSTEM WILL SWEEP ACROSS THE
COMMONWEALTH ON CHRISTMAS EVE BRINGING WIDESPREAD SHOWERS AND A
CHANCE FOR THUNDERSTORMS. WINDY AND COLDER CONDITIONS WILL FOLLOW
WITH SCATTERED SNOW SHOWERS ACROSS THE WEST AND NORTH FOR
CHRISTMAS DAY. MILDER CONDITIONS WILL RETURN LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
CLOUDS COVERING ALL OF THE AREA AS A VIGOROUS SHORT WAVE ROLLS
OVERHEAD EARLY TONIGHT. ENOUGH LIFT PRESENT TO MAKE SOME ICE
CRYSTALS FALL OUT OF THE MID DECK AND SEED THE LOWER CLOUDS.
THUS...SOME FLURRIES ARE EXPECTED MAINLY EARLY TONIGHT OVER THE
LAURELS AND ALL NIGHT ALONG THE NRN TIER. WILL LEAVE ACCUMS OUT
OF THE FCST...BUT THE LIGHTEST OF DUSTINGS IS POSSIBLE. MINS
PROBABLY A HOMOGENEOUS 20-25F ACROSS THE BOARD.

&&

.SHORT TERM /8 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
DEEP LAYER DRYING BEHIND A DEPARTING 5H WAVE AND UPPER LEVEL
RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF NOT ALL OF
CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS PLAGUED US FOR
MORE THAN A WEEK WILL HAVE A CHANCE TO MIX OUT...BUT TRANSITORY
SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW PROCESS OVER THE
NORTH.

PRIOR TO THAT...SOME AREAS COULD PERHAPS SEE A FLURRY IN THE PRE
DAWN HOURS SUNDAY BEFORE THE WAVE QUICKLY EXITS EASTWARD. WENT
CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE MID TO
UPPER 30S NORTH TO THE LOWER 40S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT...THOUGH LOW CLOUDS
SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A SHORTWAVE
WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID- LVL DECK
AS WELL. THAT MID DECK WILL DECREASE THE PROBABILITY FOR A THICKER
LOW DECK. THE SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH SW
FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO...JST AND UNV. IFR REMAINS POSSIBLE AT JST
BETWEEN 09 TO 13Z...AND BFD SHOULD BE IFR THROUGH MOST OF THE
PERIOD. MAINLY VFR THROUGH THE EASTERN TAF SITES.
 BFD SHOULD LIFT TO MVFR BY LATE TOMORROW MORNING...THOUGH MVFR
SHOULD REMAIN POSSIBLE AT BFD THROUGH TOMORROW...AND IFR RETURNING
AT BFD TOMORROW EVENING.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DEVOIR
LONG TERM...GRUMM
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 210446
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1146 PM EST SAT DEC 20 2014

.SYNOPSIS...
AN AMPLIFYING UPPER RIDGE WILL MOVE INTO THE REGION ON
SUNDAY. TEMPERATURES WILL THEN BECOME JUST SLIGHTLY MILDER BUT
UNSETTLED CONDITIONS WILL BEGIN ON MONDAY NIGHT AND PREVAIL
THROUGH MID WEEK. A VIGOROUS STORM SYSTEM WILL SWEEP ACROSS THE
COMMONWEALTH ON CHRISTMAS EVE BRINGING WIDESPREAD SHOWERS AND A
CHANCE FOR THUNDERSTORMS. WINDY AND COLDER CONDITIONS WILL FOLLOW
WITH SCATTERED SNOW SHOWERS ACROSS THE WEST AND NORTH FOR
CHRISTMAS DAY. MILDER CONDITIONS WILL RETURN LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
CLOUDS COVERING ALL OF THE AREA AS A VIGOROUS SHORT WAVE ROLLS
OVERHEAD EARLY TONIGHT. ENOUGH LIFT PRESENT TO MAKE SOME ICE
CRYSTALS FALL OUT OF THE MID DECK AND SEED THE LOWER CLOUDS.
THUS...SOME FLURRIES ARE EXPECTED MAINLY EARLY TONIGHT OVER THE
LAURELS AND ALL NIGHT ALONG THE NRN TIER. WILL LEAVE ACCUMS OUT
OF THE FCST...BUT THE LIGHTEST OF DUSTINGS IS POSSIBLE. MINS
PROBABLY A HOMOGENEOUS 20-25F ACROSS THE BOARD.

&&

.SHORT TERM /8 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
DEEP LAYER DRYING BEHIND A DEPARTING 5H WAVE AND UPPER LEVEL
RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF NOT ALL OF
CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS PLAGUED US FOR
MORE THAN A WEEK WILL HAVE A CHANCE TO MIX OUT...BUT TRANSITORY
SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW PROCESS OVER THE
NORTH.

PRIOR TO THAT...SOME AREAS COULD PERHAPS SEE A FLURRY IN THE PRE
DAWN HOURS SUNDAY BEFORE THE WAVE QUICKLY EXITS EASTWARD. WENT
CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE MID TO
UPPER 30S NORTH TO THE LOWER 40S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT...THOUGH LOW CLOUDS
SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A SHORTWAVE
WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID- LVL DECK
AS WELL. THAT MID DECK WILL DECREASE THE PROBABILITY FOR A THICKER
LOW DECK. THE SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH SW
FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO...JST AND UNV. IFR REMAINS POSSIBLE AT JST
BETWEEN 09 TO 13Z...AND BFD SHOULD BE IFR THROUGH MOST OF THE
PERIOD. MAINLY VFR THROUGH THE EASTERN TAF SITES.
 BFD SHOULD LIFT TO MVFR BY LATE TOMORROW MORNING...THOUGH MVFR
SHOULD REMAIN POSSIBLE AT BFD THROUGH TOMORROW...AND IFR RETURNING
AT BFD TOMORROW EVENING.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DEVOIR
LONG TERM...GRUMM
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 210446
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1146 PM EST SAT DEC 20 2014

.SYNOPSIS...
AN AMPLIFYING UPPER RIDGE WILL MOVE INTO THE REGION ON
SUNDAY. TEMPERATURES WILL THEN BECOME JUST SLIGHTLY MILDER BUT
UNSETTLED CONDITIONS WILL BEGIN ON MONDAY NIGHT AND PREVAIL
THROUGH MID WEEK. A VIGOROUS STORM SYSTEM WILL SWEEP ACROSS THE
COMMONWEALTH ON CHRISTMAS EVE BRINGING WIDESPREAD SHOWERS AND A
CHANCE FOR THUNDERSTORMS. WINDY AND COLDER CONDITIONS WILL FOLLOW
WITH SCATTERED SNOW SHOWERS ACROSS THE WEST AND NORTH FOR
CHRISTMAS DAY. MILDER CONDITIONS WILL RETURN LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
CLOUDS COVERING ALL OF THE AREA AS A VIGOROUS SHORT WAVE ROLLS
OVERHEAD EARLY TONIGHT. ENOUGH LIFT PRESENT TO MAKE SOME ICE
CRYSTALS FALL OUT OF THE MID DECK AND SEED THE LOWER CLOUDS.
THUS...SOME FLURRIES ARE EXPECTED MAINLY EARLY TONIGHT OVER THE
LAURELS AND ALL NIGHT ALONG THE NRN TIER. WILL LEAVE ACCUMS OUT
OF THE FCST...BUT THE LIGHTEST OF DUSTINGS IS POSSIBLE. MINS
PROBABLY A HOMOGENEOUS 20-25F ACROSS THE BOARD.

&&

.SHORT TERM /8 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
DEEP LAYER DRYING BEHIND A DEPARTING 5H WAVE AND UPPER LEVEL
RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF NOT ALL OF
CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS PLAGUED US FOR
MORE THAN A WEEK WILL HAVE A CHANCE TO MIX OUT...BUT TRANSITORY
SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW PROCESS OVER THE
NORTH.

PRIOR TO THAT...SOME AREAS COULD PERHAPS SEE A FLURRY IN THE PRE
DAWN HOURS SUNDAY BEFORE THE WAVE QUICKLY EXITS EASTWARD. WENT
CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE MID TO
UPPER 30S NORTH TO THE LOWER 40S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT...THOUGH LOW CLOUDS
SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A SHORTWAVE
WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID- LVL DECK
AS WELL. THAT MID DECK WILL DECREASE THE PROBABILITY FOR A THICKER
LOW DECK. THE SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH SW
FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO...JST AND UNV. IFR REMAINS POSSIBLE AT JST
BETWEEN 09 TO 13Z...AND BFD SHOULD BE IFR THROUGH MOST OF THE
PERIOD. MAINLY VFR THROUGH THE EASTERN TAF SITES.
 BFD SHOULD LIFT TO MVFR BY LATE TOMORROW MORNING...THOUGH MVFR
SHOULD REMAIN POSSIBLE AT BFD THROUGH TOMORROW...AND IFR RETURNING
AT BFD TOMORROW EVENING.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DEVOIR
LONG TERM...GRUMM
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 210446
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1146 PM EST SAT DEC 20 2014

.SYNOPSIS...
AN AMPLIFYING UPPER RIDGE WILL MOVE INTO THE REGION ON
SUNDAY. TEMPERATURES WILL THEN BECOME JUST SLIGHTLY MILDER BUT
UNSETTLED CONDITIONS WILL BEGIN ON MONDAY NIGHT AND PREVAIL
THROUGH MID WEEK. A VIGOROUS STORM SYSTEM WILL SWEEP ACROSS THE
COMMONWEALTH ON CHRISTMAS EVE BRINGING WIDESPREAD SHOWERS AND A
CHANCE FOR THUNDERSTORMS. WINDY AND COLDER CONDITIONS WILL FOLLOW
WITH SCATTERED SNOW SHOWERS ACROSS THE WEST AND NORTH FOR
CHRISTMAS DAY. MILDER CONDITIONS WILL RETURN LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
CLOUDS COVERING ALL OF THE AREA AS A VIGOROUS SHORT WAVE ROLLS
OVERHEAD EARLY TONIGHT. ENOUGH LIFT PRESENT TO MAKE SOME ICE
CRYSTALS FALL OUT OF THE MID DECK AND SEED THE LOWER CLOUDS.
THUS...SOME FLURRIES ARE EXPECTED MAINLY EARLY TONIGHT OVER THE
LAURELS AND ALL NIGHT ALONG THE NRN TIER. WILL LEAVE ACCUMS OUT
OF THE FCST...BUT THE LIGHTEST OF DUSTINGS IS POSSIBLE. MINS
PROBABLY A HOMOGENEOUS 20-25F ACROSS THE BOARD.

&&

.SHORT TERM /8 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
DEEP LAYER DRYING BEHIND A DEPARTING 5H WAVE AND UPPER LEVEL
RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF NOT ALL OF
CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS PLAGUED US FOR
MORE THAN A WEEK WILL HAVE A CHANCE TO MIX OUT...BUT TRANSITORY
SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW PROCESS OVER THE
NORTH.

PRIOR TO THAT...SOME AREAS COULD PERHAPS SEE A FLURRY IN THE PRE
DAWN HOURS SUNDAY BEFORE THE WAVE QUICKLY EXITS EASTWARD. WENT
CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE MID TO
UPPER 30S NORTH TO THE LOWER 40S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT...THOUGH LOW CLOUDS
SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A SHORTWAVE
WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID- LVL DECK
AS WELL. THAT MID DECK WILL DECREASE THE PROBABILITY FOR A THICKER
LOW DECK. THE SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH SW
FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO...JST AND UNV. IFR REMAINS POSSIBLE AT JST
BETWEEN 09 TO 13Z...AND BFD SHOULD BE IFR THROUGH MOST OF THE
PERIOD. MAINLY VFR THROUGH THE EASTERN TAF SITES.
 BFD SHOULD LIFT TO MVFR BY LATE TOMORROW MORNING...THOUGH MVFR
SHOULD REMAIN POSSIBLE AT BFD THROUGH TOMORROW...AND IFR RETURNING
AT BFD TOMORROW EVENING.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DEVOIR
LONG TERM...GRUMM
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 210234
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
934 PM EST SAT DEC 20 2014

.SYNOPSIS...
AN AMPLIFYING UPPER RIDGE WILL MOVE INTO THE REGION ON
SUNDAY. TEMPERATURES WILL THEN BECOME JUST SLIGHTLY MILDER BUT
UNSETTLED CONDITIONS WILL BEGIN ON MONDAY NIGHT AND PREVAIL
THROUGH MID WEEK. A VIGOROUS STORM SYSTEM WILL SWEEP ACROSS THE
COMMONWEALTH ON CHRISTMAS EVE BRINGING WIDESPREAD SHOWERS AND A
CHANCE FOR THUNDERSTORMS. WINDY AND COLDER CONDITIONS WILL FOLLOW
WITH SCATTERED SNOW SHOWERS ACROSS THE WEST AND NORTH FOR
CHRISTMAS DAY. MILDER CONDITIONS WILL RETURN LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
CLOUDS COVERING ALL OF THE AREA AS A VIGOROUS SHORT WAVE ROLLS
OVERHEAD EARLY TONIGHT. ENOUGH LIFT PRESENT TO MAKE SOME ICE
CRYSTALS FALL OUT OF THE MID DECK AND SEED THE LOWER CLOUDS.
THUS...SOME FLURRIES ARE EXPECTED MAINLY EARLY TONIGHT OVER THE
LAURELS AND ALL NIGHT ALONG THE NRN TIER. WILL LEAVE ACCUMS OUT
OF THE FCST...BUT THE LIGHTEST OF DUSTINGS IS POSSIBLE. MINS
PROBABLY A HOMOGENEOUS 20-25F ACROSS THE BOARD.

&&

.SHORT TERM /8 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
DEEP LAYER DRYING BEHIND A DEPARTING 5H WAVE AND UPPER LEVEL
RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF NOT ALL OF
CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS PLAGUED US FOR
MORE THAN A WEEK WILL HAVE A CHANCE TO MIX OUT...BUT TRANSITORY
SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW PROCESS OVER THE
NORTH.

PRIOR TO THAT...SOME AREAS COULD PERHAPS SEE A FLURRY IN THE PRE
DAWN HOURS SUNDAY BEFORE THE WAVE QUICKLY EXITS EASTWARD. WENT
CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE MID TO
UPPER 30S NORTH TO THE LOWER 40S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT. EXPECT THE
EXPANDING STRATOCU DECK LIKELY TO RETURN AGAIN TONIGHT...THOUGH
LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A
SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID-
LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH
SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO AND UNV...WITH IFR POSSIBLE AT BFD AND
JST...WITH MAINLY VFR THROUGH THE EASTERN TAF SITES.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DEVOIR
LONG TERM...GRUMM
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 210234
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
934 PM EST SAT DEC 20 2014

.SYNOPSIS...
AN AMPLIFYING UPPER RIDGE WILL MOVE INTO THE REGION ON
SUNDAY. TEMPERATURES WILL THEN BECOME JUST SLIGHTLY MILDER BUT
UNSETTLED CONDITIONS WILL BEGIN ON MONDAY NIGHT AND PREVAIL
THROUGH MID WEEK. A VIGOROUS STORM SYSTEM WILL SWEEP ACROSS THE
COMMONWEALTH ON CHRISTMAS EVE BRINGING WIDESPREAD SHOWERS AND A
CHANCE FOR THUNDERSTORMS. WINDY AND COLDER CONDITIONS WILL FOLLOW
WITH SCATTERED SNOW SHOWERS ACROSS THE WEST AND NORTH FOR
CHRISTMAS DAY. MILDER CONDITIONS WILL RETURN LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
CLOUDS COVERING ALL OF THE AREA AS A VIGOROUS SHORT WAVE ROLLS
OVERHEAD EARLY TONIGHT. ENOUGH LIFT PRESENT TO MAKE SOME ICE
CRYSTALS FALL OUT OF THE MID DECK AND SEED THE LOWER CLOUDS.
THUS...SOME FLURRIES ARE EXPECTED MAINLY EARLY TONIGHT OVER THE
LAURELS AND ALL NIGHT ALONG THE NRN TIER. WILL LEAVE ACCUMS OUT
OF THE FCST...BUT THE LIGHTEST OF DUSTINGS IS POSSIBLE. MINS
PROBABLY A HOMOGENEOUS 20-25F ACROSS THE BOARD.

&&

.SHORT TERM /8 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
DEEP LAYER DRYING BEHIND A DEPARTING 5H WAVE AND UPPER LEVEL
RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF NOT ALL OF
CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS PLAGUED US FOR
MORE THAN A WEEK WILL HAVE A CHANCE TO MIX OUT...BUT TRANSITORY
SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW PROCESS OVER THE
NORTH.

PRIOR TO THAT...SOME AREAS COULD PERHAPS SEE A FLURRY IN THE PRE
DAWN HOURS SUNDAY BEFORE THE WAVE QUICKLY EXITS EASTWARD. WENT
CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE MID TO
UPPER 30S NORTH TO THE LOWER 40S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT. EXPECT THE
EXPANDING STRATOCU DECK LIKELY TO RETURN AGAIN TONIGHT...THOUGH
LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A
SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID-
LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH
SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO AND UNV...WITH IFR POSSIBLE AT BFD AND
JST...WITH MAINLY VFR THROUGH THE EASTERN TAF SITES.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DEVOIR
LONG TERM...GRUMM
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 210019
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
719 PM EST SAT DEC 20 2014

.SYNOPSIS...
AN AMPLIFYING UPPER RIDGE WILL MOVE INTO THE REGION ON
SUNDAY. TEMPERATURES WILL THEN BECOME JUST SLIGHTLY MILDER BUT
UNSETTLED CONDITIONS WILL BEGIN ON MONDAY NIGHT AND PREVAIL
THROUGH MID WEEK. A VIGOROUS STORM SYSTEM WILL SWEEP ACROSS THE
COMMONWEALTH ON CHRISTMAS EVE BRINGING WIDESPREAD SHOWERS AND A
CHANCE FOR THUNDERSTORMS. WINDY AND COLDER CONDITIONS WILL FOLLOW
WITH SCATTERED SNOW SHOWERS ACROSS THE WEST AND NORTH FOR
CHRISTMAS DAY. MILDER CONDITIONS WILL RETURN LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 7 AM SUNDAY MORNING/...
CLOUDS CONGESTING OVER THE AREA BUT SOME AREAS STILL FREE OF THE
LOWEST DECK. A VIGOROUS SHORT WAVE ROLLING OVERHEAD EARLY TONIGHT
MAY CREATE ENOUGH LIFT AND COULD SEED THE LOWER CLOUDS WITH ICE
CRYSTALS FROM ABOVE. THUS...SOME FLURRIES ARE EXPECTED OVER THE
LAURELS AND ALONG THE NRN TIER. WILL LEAVE ACCUMS OUT OF THE FCST
FOR NOW. MINS PROBABLY A HOMOGENEOUS 20-25F ACROSS THE BOARD.

&&

.SHORT TERM /7 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
DEEP LAYER DRYING BEHIND A DEPARTING 5H WAVE AND UPPER LEVEL
RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF NOT ALL OF
CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS PLAGUED US FOR
MORE THAN A WEEK WILL HAVE A CHANCE TO MIX OUT...BUT TRANSITORY
SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW PROCESS OVER THE
NORTH.

PRIOR TO THAT...SOME AREAS COULD PERHAPS SEE A FLURRY IN THE PRE
DAWN HOURS SUNDAY BEFORE THE WAVE QUICKLY EXITS EASTWARD. WENT
CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE MID TO
UPPER 30S NORTH TO THE LOWER 40S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT. EXPECT THE
EXPANDING STRATOCU DECK LIKELY TO RETURN AGAIN TONIGHT...THOUGH
LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A
SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID-
LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH
SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO AND UNV...WITH IFR POSSIBLE AT BFD AND
JST...WITH MAINLY VFR THROUGH THE EASTERN TAF SITES.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...FITZGERALD
LONG TERM...GRUMM
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 210019
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
719 PM EST SAT DEC 20 2014

.SYNOPSIS...
AN AMPLIFYING UPPER RIDGE WILL MOVE INTO THE REGION ON
SUNDAY. TEMPERATURES WILL THEN BECOME JUST SLIGHTLY MILDER BUT
UNSETTLED CONDITIONS WILL BEGIN ON MONDAY NIGHT AND PREVAIL
THROUGH MID WEEK. A VIGOROUS STORM SYSTEM WILL SWEEP ACROSS THE
COMMONWEALTH ON CHRISTMAS EVE BRINGING WIDESPREAD SHOWERS AND A
CHANCE FOR THUNDERSTORMS. WINDY AND COLDER CONDITIONS WILL FOLLOW
WITH SCATTERED SNOW SHOWERS ACROSS THE WEST AND NORTH FOR
CHRISTMAS DAY. MILDER CONDITIONS WILL RETURN LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 7 AM SUNDAY MORNING/...
CLOUDS CONGESTING OVER THE AREA BUT SOME AREAS STILL FREE OF THE
LOWEST DECK. A VIGOROUS SHORT WAVE ROLLING OVERHEAD EARLY TONIGHT
MAY CREATE ENOUGH LIFT AND COULD SEED THE LOWER CLOUDS WITH ICE
CRYSTALS FROM ABOVE. THUS...SOME FLURRIES ARE EXPECTED OVER THE
LAURELS AND ALONG THE NRN TIER. WILL LEAVE ACCUMS OUT OF THE FCST
FOR NOW. MINS PROBABLY A HOMOGENEOUS 20-25F ACROSS THE BOARD.

&&

.SHORT TERM /7 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
DEEP LAYER DRYING BEHIND A DEPARTING 5H WAVE AND UPPER LEVEL
RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF NOT ALL OF
CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS PLAGUED US FOR
MORE THAN A WEEK WILL HAVE A CHANCE TO MIX OUT...BUT TRANSITORY
SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW PROCESS OVER THE
NORTH.

PRIOR TO THAT...SOME AREAS COULD PERHAPS SEE A FLURRY IN THE PRE
DAWN HOURS SUNDAY BEFORE THE WAVE QUICKLY EXITS EASTWARD. WENT
CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE MID TO
UPPER 30S NORTH TO THE LOWER 40S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT. EXPECT THE
EXPANDING STRATOCU DECK LIKELY TO RETURN AGAIN TONIGHT...THOUGH
LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A
SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID-
LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH
SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO AND UNV...WITH IFR POSSIBLE AT BFD AND
JST...WITH MAINLY VFR THROUGH THE EASTERN TAF SITES.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...FITZGERALD
LONG TERM...GRUMM
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 210001
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
701 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE SLIDING EASTWARD THROUGH QUEBEC WITH A SECOND HIGH
PRESSURE CELL OVER THE EASTERN GREAT LAKES AND OHIO VALLEY WILL
KEEP MAINTAIN DRY WEATHER ACROSS CENTRAL PENNSYLVANIA FOR THE REST
OF THIS WEEKEND. AN AMPLIFYING UPPER RIDGE MOVING INTO THE REGION
WILL BRING INCREASING AMOUNTS OF SUNSHINE ON SUNDAY...BUT WILL BE
QUICKLY REPLACED BY A LARGE STORM SYSTEM TRACKING ACROSS THE
CENTRAL UNITED STATES. MOISTURE ASSOCIATED WITH THAT STORM AND
INCREASING EAST FLOW OFF OF THE WESTERN ATLANTIC WILL BRING
INCREASING CLOUDS ON MONDAY...WITH QUITE MILD BUT UNSETTLED
CONDITIONS PREVAILING THROUGH MID WEEK. A VIGOROUS STORM SYSTEM
WILL SWEEP ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND A CHANCE FOR THUNDERSTORMS...FOLLOWED BY
WINDY AND COLDER CONDITIONS WITH SCATTERED SNOW SHOWERS AND
FLURRIES ACROSS THE WEST AND NORTH FOR CHRISTMAS DAY. MILDER
CONDITIONS WILL ARRIVE ONCE AGAIN BY LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SUBSIDENCE AND DOWNSLOPING OVER MUCH OF THE LAUREL HIGHLANDS AND
PARTS OF THE CENTRAL AND SOUTH CENTRAL MOUNTAINS IS BRINGING SOME
MUCH NEEDED SUNSHINE TO THOSE AREAS. VISIBLE IMAGERY INDICATES THE
NORTHWARD EXTENT PUSHING TOWARDS CENTRAL CLEARFIELD COUNTY AND
SOUTHERN CENTRE COUNTY...AND IT APPEARS LIKELY TO REACH A LITTLE
FARTHER NORTH BEFORE SUNSET.

EXPECT CLOUDS TO FILL BACK IN OVERNIGHT...AS 5H WAVE TRACKS ACROSS
THE OHIO VALLEY AND INTO SOUTHWEST PA BY 12Z SUN. MINS WILL BE
FAIRLY UNIFORM AND RANGE FROM THE LOWER 20S NORTH TO THE UPPER 20S
SOUTHEAST.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
DEEP LAYER DRYING BEHIND THE AFOREMENTIONED DEPARTING 5H WAVE AND
UPPER LEVEL RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF
NOT ALL OF CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS
PLAGUED US FOR MORE THAN A WEEK WILL HAVE A CHANCE TO MIX
OUT...BUT TRANSITORY SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW
PROCESS OVER THE NORTH.

PRIOR TO THAT...SOME AREAS COULD PERHAPS SEE A FLURRY IN THE PRE
DAWN HOURS SUNDAY BEFORE THE WAVE QUICKLY EXITS EASTWARD. WENT
CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE MID TO
UPPER 30S NORTH TO THE LOWER 40S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
 A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT. EXPECT THE
EXPANDING STRATOCU DECK LIKELY TO RETURN AGAIN TONIGHT...THOUGH
LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A
SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID-
LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH
SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO AND UNV...WITH IFR POSSIBLE AT BFD AND
JST...WITH MAINLY VFR THROUGH THE EASTERN TAF SITES.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM
AVIATION...DEVOIR/CERU





000
FXUS61 KCTP 210001
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
701 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE SLIDING EASTWARD THROUGH QUEBEC WITH A SECOND HIGH
PRESSURE CELL OVER THE EASTERN GREAT LAKES AND OHIO VALLEY WILL
KEEP MAINTAIN DRY WEATHER ACROSS CENTRAL PENNSYLVANIA FOR THE REST
OF THIS WEEKEND. AN AMPLIFYING UPPER RIDGE MOVING INTO THE REGION
WILL BRING INCREASING AMOUNTS OF SUNSHINE ON SUNDAY...BUT WILL BE
QUICKLY REPLACED BY A LARGE STORM SYSTEM TRACKING ACROSS THE
CENTRAL UNITED STATES. MOISTURE ASSOCIATED WITH THAT STORM AND
INCREASING EAST FLOW OFF OF THE WESTERN ATLANTIC WILL BRING
INCREASING CLOUDS ON MONDAY...WITH QUITE MILD BUT UNSETTLED
CONDITIONS PREVAILING THROUGH MID WEEK. A VIGOROUS STORM SYSTEM
WILL SWEEP ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND A CHANCE FOR THUNDERSTORMS...FOLLOWED BY
WINDY AND COLDER CONDITIONS WITH SCATTERED SNOW SHOWERS AND
FLURRIES ACROSS THE WEST AND NORTH FOR CHRISTMAS DAY. MILDER
CONDITIONS WILL ARRIVE ONCE AGAIN BY LATE THIS WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SUBSIDENCE AND DOWNSLOPING OVER MUCH OF THE LAUREL HIGHLANDS AND
PARTS OF THE CENTRAL AND SOUTH CENTRAL MOUNTAINS IS BRINGING SOME
MUCH NEEDED SUNSHINE TO THOSE AREAS. VISIBLE IMAGERY INDICATES THE
NORTHWARD EXTENT PUSHING TOWARDS CENTRAL CLEARFIELD COUNTY AND
SOUTHERN CENTRE COUNTY...AND IT APPEARS LIKELY TO REACH A LITTLE
FARTHER NORTH BEFORE SUNSET.

EXPECT CLOUDS TO FILL BACK IN OVERNIGHT...AS 5H WAVE TRACKS ACROSS
THE OHIO VALLEY AND INTO SOUTHWEST PA BY 12Z SUN. MINS WILL BE
FAIRLY UNIFORM AND RANGE FROM THE LOWER 20S NORTH TO THE UPPER 20S
SOUTHEAST.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
DEEP LAYER DRYING BEHIND THE AFOREMENTIONED DEPARTING 5H WAVE AND
UPPER LEVEL RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF
NOT ALL OF CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS
PLAGUED US FOR MORE THAN A WEEK WILL HAVE A CHANCE TO MIX
OUT...BUT TRANSITORY SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW
PROCESS OVER THE NORTH.

PRIOR TO THAT...SOME AREAS COULD PERHAPS SEE A FLURRY IN THE PRE
DAWN HOURS SUNDAY BEFORE THE WAVE QUICKLY EXITS EASTWARD. WENT
CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE MID TO
UPPER 30S NORTH TO THE LOWER 40S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
 A WEAK AND SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH
SUBSIDENCE. THE CIG RESTRICTIONS WILL SPREAD AND INCREASE DUE TO
THE STRENGTHENING OF THE INVERSION OVERNIGHT. EXPECT THE
EXPANDING STRATOCU DECK LIKELY TO RETURN AGAIN TONIGHT...THOUGH
LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS PREVIOUS NIGHTS. A
SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING A THICKENING MID-
LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO BE LIGHT...WITH
SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW PRESSURE SYSTEM
BEGINS TO DEEPEN OVER THE CENTRAL U.S. EXPECT MVFR CIGS AT THE
CENTRAL SITES AOO AND UNV...WITH IFR POSSIBLE AT BFD AND
JST...WITH MAINLY VFR THROUGH THE EASTERN TAF SITES.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM
AVIATION...DEVOIR/CERU




000
FXUS61 KCTP 201942
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
242 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE SLIDING EASTWARD THROUGH QUEBEC WITH A SECOND HIGH
PRESSURE CELL OVER THE EASTERN GREAT LAKES AND OHIO VALLEY WILL
KEEP MAINTAIN DRY WEATHER ACROSS CENTRAL PENNSYLVANIA FOR THE REST
OF THIS WEEKEND. AN AMPLIFYING UPPER RIDGE MOVING INTO THE REGION
WILL BRING INCREASING AMOUNTS OF SUNSHINE ON SUNDAY...BUT WILL BE
QUICKLY REPLACED BY A LARGE STORM SYSTEM TRACKING ACROSS THE
CENTRAL UNITED STATES. MOISTURE ASSOCIATED WITH THAT STORM AND
INCREASING EAST FLOW OFF OF THE WESTERN ATLANTIC WILL BRING
INCREASING CLOUDS ON MONDAY...WITH QUITE MILD BUT UNSETTLED
CONDITIONS PREVAILING THROUGH MID WEEK. A VIGOROUS STORM SYSTEM
WILL SWEEP ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND A CHANCE FOR THUNDERSTORMS...FOLLOWED BY
WINDY AND COLDER CONDITIONS WITH SCATTERED SNOW SHOWERS AND
FLURRIES ACROSS THE WEST AND NORTH FOR CHRISTMAS DAY. MILDER
CONDITIONS WILL ARRIVE ONCE AGAIN BY LATE THIS WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
SUBSIDENCE AND DOWNSLOPING OVER MUCH OF THE LAUREL HIGHLANDS AND
PARTS OF THE CENTRAL AND SOUTH CENTRAL MOUNTAINS IS BRINGING SOME
MUCH NEEDED SUNSHINE TO THOSE AREAS. VISIBLE IMAGERY INDICATES THE
NORTHWARD EXTENT PUSHING TOWARDS CENTRAL CLEARFIELD COUNTY AND
SOUTHERN CENTRE COUNTY...AND IT APPEARS LIKELY TO REACH A LITTLE
FARTHER NORTH BEFORE SUNSET.

EXPECT CLOUDS TO FILL BACK IN OVERNIGHT...AS 5H WAVE TRACKS ACROSS
THE OHIO VALLEY AND INTO SOUTHWEST PA BY 12Z SUN. MINS WILL BE
FAIRLY UNIFORM AND RANGE FROM THE LOWER 20S NORTH TO THE UPPER 20S
SOUTHEAST.

&&

.SHORT TERM /SUNDAY/...
DEEP LAYER DRYING BEHIND THE AFOREMENTIONED DEPARTING 5H WAVE AND
UPPER LEVEL RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF
NOT ALL OF CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS
PLAGUED US FOR MORE THAN A WEEK WILL HAVE A CHANCE TO MIX
OUT...BUT TRANSITORY SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW
PROCESS OVER THE NORTH.

PRIOR TO THAT...SOME AREAS COULD PERHAPS SEE A FLURRY IN THE PRE
DAWN HOURS SUNDAY BEFORE THE WAVE QUICKLY EXITS EASTWARD. WENT
CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE MID TO
UPPER 30S NORTH TO THE LOWER 40S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH SUBSIDENCE
INVERSION THIS MORNING...WITH MVFR CIGS.  LOWER CIGS WILL PERSIST
IN THE NORTHERN MTNS...WITH IMPROVING CIGS CENTRAL AND SOUTH. WINDS
WILL BE LIGHT FROM THE WEST.

CIG RESTRICTIONS IN EXPANDING STRATOCU DECK LIKELY RETURN AGAIN
TONIGHT...THOUGH LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS
PREVIOUS NIGHTS. A SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING
A THICKENING MID-LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO
BE LIGHT...WITH SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW
PRESSURE SYSTEM BEGINS TO DEEPEN OVER THE CENTRAL U.S.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM
AVIATION...DEVOIR/RXR




000
FXUS61 KCTP 201942
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
242 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE SLIDING EASTWARD THROUGH QUEBEC WITH A SECOND HIGH
PRESSURE CELL OVER THE EASTERN GREAT LAKES AND OHIO VALLEY WILL
KEEP MAINTAIN DRY WEATHER ACROSS CENTRAL PENNSYLVANIA FOR THE REST
OF THIS WEEKEND. AN AMPLIFYING UPPER RIDGE MOVING INTO THE REGION
WILL BRING INCREASING AMOUNTS OF SUNSHINE ON SUNDAY...BUT WILL BE
QUICKLY REPLACED BY A LARGE STORM SYSTEM TRACKING ACROSS THE
CENTRAL UNITED STATES. MOISTURE ASSOCIATED WITH THAT STORM AND
INCREASING EAST FLOW OFF OF THE WESTERN ATLANTIC WILL BRING
INCREASING CLOUDS ON MONDAY...WITH QUITE MILD BUT UNSETTLED
CONDITIONS PREVAILING THROUGH MID WEEK. A VIGOROUS STORM SYSTEM
WILL SWEEP ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND A CHANCE FOR THUNDERSTORMS...FOLLOWED BY
WINDY AND COLDER CONDITIONS WITH SCATTERED SNOW SHOWERS AND
FLURRIES ACROSS THE WEST AND NORTH FOR CHRISTMAS DAY. MILDER
CONDITIONS WILL ARRIVE ONCE AGAIN BY LATE THIS WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
SUBSIDENCE AND DOWNSLOPING OVER MUCH OF THE LAUREL HIGHLANDS AND
PARTS OF THE CENTRAL AND SOUTH CENTRAL MOUNTAINS IS BRINGING SOME
MUCH NEEDED SUNSHINE TO THOSE AREAS. VISIBLE IMAGERY INDICATES THE
NORTHWARD EXTENT PUSHING TOWARDS CENTRAL CLEARFIELD COUNTY AND
SOUTHERN CENTRE COUNTY...AND IT APPEARS LIKELY TO REACH A LITTLE
FARTHER NORTH BEFORE SUNSET.

EXPECT CLOUDS TO FILL BACK IN OVERNIGHT...AS 5H WAVE TRACKS ACROSS
THE OHIO VALLEY AND INTO SOUTHWEST PA BY 12Z SUN. MINS WILL BE
FAIRLY UNIFORM AND RANGE FROM THE LOWER 20S NORTH TO THE UPPER 20S
SOUTHEAST.

&&

.SHORT TERM /SUNDAY/...
DEEP LAYER DRYING BEHIND THE AFOREMENTIONED DEPARTING 5H WAVE AND
UPPER LEVEL RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF
NOT ALL OF CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS
PLAGUED US FOR MORE THAN A WEEK WILL HAVE A CHANCE TO MIX
OUT...BUT TRANSITORY SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW
PROCESS OVER THE NORTH.

PRIOR TO THAT...SOME AREAS COULD PERHAPS SEE A FLURRY IN THE PRE
DAWN HOURS SUNDAY BEFORE THE WAVE QUICKLY EXITS EASTWARD. WENT
CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE MID TO
UPPER 30S NORTH TO THE LOWER 40S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...

THE MOST SIGNIFICANT FORECAST ISSUE IN THE LONG TERM IS THE
EVOLUTION OF THE MASSIVE CYCLONE TO OUR WEST 23-25 DECEMBER.
STRONG SOUTHERLY FLOW AHEAD OF THIS SYSTEM WILL BRING WARM AIR
INTO THE REGION LATE MONDAY INTO TUESDAY. BY TUESDAY AND WEDNESDAY
MANY LOW- LEVEL TEMPERATURE AND MOISTURE FIELDS WILL BE WELL ABOVE
THEIR SEASONAL VALUES. THIS IMPLIES VERY WARM WEATHER TUESDAY AND
WEDNESDAY...WHEN THE SHALLOW COLD AIR SCOURS OUT EAST OF THE
MOUNTAINS.

A COLD FRONT WITH STRONG WINDS WILL PRODUCE COLDER
CONDITIONS...LIKELY LATE CHRISTMAS EVE INTO CHRISTMAS DAY. THERE
WILL BE STRONG WESTERLY WINDS AND STRONG WIND GUSTS. SNOW SHOWERS
ARE LIKELY BEHIND THE SYSTEM IN WESTERN AREAS.

THE CHANGEABLE DETAILS...MONDAY THE ENSEMBLE FORECAST SHOWS A
WAVE PASSING TO OUR SOUTH WHICH COULD PRODUCE LIGHT SNOW OR A
MIX...MAINLY IN SOUTHEASTERN AREAS. THE IMPLIED LOW-LEVEL BOUNDARY
IS THE RETREATING COLD AIR TO OUR NORTHEAST AS THE STRONG CYCLONE
TO OUR WEST BEGINS TO TAKE SHAPE. IMPLIED LOW-LEVEL AGEOSTROPHIC
NORTHERLY FLOW HOLDING LOW-LEVEL COLD AIR IN MONDAY INTO TUESDAY.

TUESDAY THE COLD AIR SHOULD CONTINUE TO ERODE. HAD TO KEEP SOME
FREEZE RAIN/DRIZZLE IN NORTHEASTERN AREAS OVERNIGHT MONDAY INTO
TUESDAY BASED ON IMPLIED AGEOSTROPHIC FLOW AND ENSEMBLE
PRECIPITATION TYPES. BUT DURING THE DAY TUESDAY THE WARM AIR
SHOULD WIN OUT. THOUGH ALL SYSTEMS SHOW SOME HINTS OF COLD AIR
DAMMING....DAYTIME HIGHS EAST/NORTHEAST AREAS WILL BE WELL BELOW
WHAT ONE MIGHT EXPECT WITH 6-10C 850 MB TEMPS.

ANY PRECIPITATION TUESDAY AND WEDNESDAY SHOULD BE RAIN MUCH AFTER
NOON TUESDAY IN THE NORTHEAST. PRECIPITATION ON TUESDAY SHOULD BE
LIGHT...ENSEMBLES SHOW PROBABILITIES IN THE 20-30 RANGE AND LIGHT
AMOUNTS. THE PATTERN...SHARP NORTH-SOUTH FRONT TO OUR
WEST...IMPLIES SOME ISOLATED SHOWERS BUT THE MAIN RAIN EVENT
SHOULD WITHIN 3-6 HOURS OF THE FRONT.

TUESDAY THE STRONG CYCLONE...WITH SOME OF THE LOWEST SURFACE
PRESSURES IN THE EASTERN US ON 24 DECEMBER IN THE PAST 30 YEARS
WILL MOVE INTO THE GREAT LAKES. PRESSURE ANOMALIES ARE -3 TO -4
SIGMA BELOW NORMAL WITH A RETURN PERIOD ON THE ORDER OF 30 YEARS
IN SOME FORECAST SYSTEMS.

THE FRONT ASSOCIATED WITH THE CYCLONE PUSHES INTO OUR REGION
WEDNESDAY...AT THIS TIME THE 850 MB SOUTHERLY WINDS ARE FORECAST
TO BE ABOUT +3 SIGMA ABOVE NORMAL. THE STRONG SOUTHERLY FLOW...THE
HIGH PRECIPITABLE WATER...THE STRONG FRONT ALL IMPLY A FRONTAL
RAIN EVENT AND PERHAPS SOME RARE LATE DECEMBER (ELEVATED)
CONVECTION. IF THIS WERE AUTUMN OR SPRING WE MIGHT BE THINKING
QLCS. BUT SURFACE CAPE IS VIRTUALLY NON-EXISTENT BUT SHOWERY RAIN
AND PERHAPS ISOLATED THUNDER POSSIBLE.

DO NOT LIKE HAVING POPS ABOVE 60 TO 66 PERCENT AT DAY 5 IN 12 HOUR
PERIODS. TIMING WILL CLEARLY CHANGE BUT HAVE HIGH POPS FOR
CONSISTENCY WITH OTHER OFFICES.

CHRISTMAS EVE AND EARLY CHRISTMAS IS THE AREA OF HIGH UNCERTAINTY
AS TO WHEN THE COLD AIR COMES IN. THIS WILL DICTATE WHEN THE RAIN
COMES AND WHEN THE GUSTY WINDS SET IN. GRADIENTS ARE WHERE
FORECASTS ARE THEIR POOREST. BUT BY CHRISTMAS MORNING MOST IF NOT
ALL OF THE REGION SHOULD BE BELOW 0C AT 850 AND THE STRONG
WESTERLY WINDS SHOULD BE MIXING DOWN BEHIND THE FRONTAL BOUNDARY.
WINDY OVERNIGHT CHRISTMAS EVE INTO CHRISTMAS DAY. ANY RESIDUAL
PRECIPITATION SHOULD BE SNOW/SNOW SHOWERS AND FLURRIES.

TEMPERATURES SHOULD REBOUND FRIDAY AHEAD OF ANOTHER NORTHERN STREAM
WAVE MOVING INTO THE MID-WEST. THIS SHOULD RAISE OUR HEIGHTS AND
TEMPERATURES FRIDAY INTO EARLY SATURDAY. IT APPEARS A SERIES OF
WAVES MAY EVENTUALLY CARVE OUT A TROUGH OVER THE EAST-CENTRAL US. IF
SO...WE COULD END DECEMBER A BIT ON THE CHILLY SIDE.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH SUBSIDENCE
INVERSION THIS MORNING...WITH MVFR CIGS.  LOWER CIGS WILL PERSIST
IN THE NORTHERN MTNS...WITH IMPROVING CIGS CENTRAL AND SOUTH. WINDS
WILL BE LIGHT FROM THE WEST.

CIG RESTRICTIONS IN EXPANDING STRATOCU DECK LIKELY RETURN AGAIN
TONIGHT...THOUGH LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS
PREVIOUS NIGHTS. A SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING
A THICKENING MID-LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO
BE LIGHT...WITH SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW
PRESSURE SYSTEM BEGINS TO DEEPEN OVER THE CENTRAL U.S.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...GRUMM
AVIATION...DEVOIR/RXR





000
FXUS61 KCTP 201932
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
232 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE SLIDING EASTWARD THROUGH QUEBEC WITH A SECOND HIGH
PRESURE CELL OVER THE EASTERN GREAT LAKES AND OHIO VALLEY WILL
KEEP MAINTAIN DRY WEATHER ACROSS CENTRAL PENNSYLVANIA FOR THE REST
OF THIS WEEKEND. AN AMPLIFYING UPPER RIDGE MOVING INTO THE REGION
WILL BRING INCREASING AMOUNTS OF SUNSHINE ON SUNDAY...BUT WILL BE
QUICKLY REPLACED BY A LARGE STORM SYSTEM TRACKING ACROSS THE
CENTRAL UNITED STATES. MOISTURE ASSOCIATED WITH THAT STORM AND
INCREASING EAST FLOW OFF OF THE WESTERN ATLANTIC WILL BRING
INCREASING CLOUDS ON MONDAY...WITH QUITE MILD BUT UNSETTLED
CONDITIONS PREVAILING THROUGH MID WEEK. A VIGOROUS STORM SYSTEM
WILL SWEEP ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND A CHANCE FOR THUNDERSTORMS...FOLLOWED BY
WINDY AND COLDER CONDITIONS WITH SCATTERED SNOW SHOWERS AND
FLURRIES ACROSS THE WEST AND NORTH FOR CHRISTMAS DAY. MILDER
CONDITIONS WILL ARRIVE ONCE AGAIN BY LATE THIS WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
SUBSIDENCE AND DOWNSLOPING OVER MUCH OF THE LAUREL HIGHLANDS AND
PARTS OF THE CENTRAL AND SOUTH CENTRAL MOUNTAINS IS BRINGING SOME
MUCH NEEDED SUNSHINE TO THOSE AREAS. VISIBLE IMAGERY INDICATES THE
NORTHWARD EXTENT PUSHING TOWARDS CENTRAL CLEARFIELD COUNTY AND
SOUTHERN CENTRE COUNTY...AND IT APPEARS LIKELY TO REACH A LITTLE
FARTHER NORTH BEFORE SUNSET.

EXPECT CLOUDS TO FILL BACK IN OVERNIGHT...AS 5H WAVE TRACKS ACROSS
THE OHIO VALLEY AND INTO SOUTHWEST PA BY 12Z SUN. MINS WILL BE
FAIRLY UNIFORM AND RANGE FROM THE LOWER 20S NORTH TO THE UPPER 20S
SOUTHEAST.

&&

.SHORT TERM /SUNDAY/...
DEEP LAYER DRYING BEHIND THE AFOREMENTIONED DEPARTING 5H WAVE AND
UPPER LEVEL RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF
NOT ALL OF CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS
PLAGUED US FOR MORE THAN A WEEK WILL HAVE A CHANCE TO MIX
OUT...BUT TRANSITORY SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW
PROCESS OVER THE NORTH.

PRIOR TO THAT...SOME AREAS COULD PERHAPS SEE A FLURRY IN THE PRE
DAWN HOURS SUNDAY BEFORE THE WAVE QUICKLY EXITS EASTWARD. WENT
CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE MID TO
UPPER 30S NORTH TO THE LOWER 40S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
INCREASINGLY MOIST SERLY FLOW WILL DEVELOP OFF THE ATLANTIC EARLY
NEXT WEEK IN GRADIENT BTWN RETREATING HIGH OVR NEW ENG AND WEAK
LOW RIDING UP THE E COAST. THE INFLUX OF LOW LVL MOISTURE...COMBINED
WITH OROGRAPHIC LIFT...WILL LIKELY YIELD DAMP AND DRIZZLY WX MON
NITE THROUGH TUESDAY. MDLS HINT AT PERHAPS JUST ENOUGH LOW LVL
COLD AIR FOR AN INITIAL PERIOD OF -FZRA/FZDZ OVR THE HIGHER
TERRAIN OF THE APPALACHIANS MON NITE.

MED RANGE GUIDANCE HAS CONVERGED ON TIMING/TRACK OF DEEP TROUGH
AND ASSOC SFC LOW DURING MID WEEK...ALL OF WHICH POINTS TOWARD A
MILD AND RAINY CHRISTMAS EVE IN WARM SECTOR OF THIS SYSTEM. BLEND
OF MED RANGE GUIDANCE SUPPORTS ARND 1 INCH OF RAIN...FALLING
MOSTLY WITH PASSAGE OF LL JET/PLUME OF ANOMALOUS PWATS WEDNESDAY.
SURGE OF VERY WARM AIR SHOULD PRECEDE THE TRAILING COLD FRONT...PUSHING
READINGS INTO THE 50S OVR MOST OF THE AREA WEDNESDAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS IS LIKELY WED NIGHT INTO THURSDAY OVR THE W MTNS...PERHAPS
BRINGING A WHITE XMAS TO THE ALLEGHENY PLATEAU. THE BIGGER STORY
MAY BE THE STRONG/GUSTY WINDS WED NITE/THURSDAY. DEEPENING SFC
LOWS TRACKING THRU THE E GRT LKS TYPICALLY BRING CENTRAL PA SOME
OF OUR STRONGEST WINDS AND LATEST GUIDANCE SUGGESTS WINDS COULD
BE NEAR ADVISORY CRITERIA ON CHRISTMAS.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
00Z ECENS AND GEFS SHOWING THE UPPER TROF QUICKLY LIFTING OUT BY
FRIDAY.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH SUBSIDENCE
INVERSION THIS MORNING...WITH MVFR CIGS.  LOWER CIGS WILL PERSIST
IN THE NORTHERN MTNS...WITH IMPROVING CIGS CENTRAL AND SOUTH. WINDS
WILL BE LIGHT FROM THE WEST.

CIG RESTRICTIONS IN EXPANDING STRATOCU DECK LIKELY RETURN AGAIN
TONIGHT...THOUGH LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS
PREVIOUS NIGHTS. A SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING
A THICKENING MID-LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO
BE LIGHT...WITH SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW
PRESSURE SYSTEM BEGINS TO DEEPEN OVER THE CENTRAL U.S.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/EVANEGO
AVIATION...DEVOIR/RXR




000
FXUS61 KCTP 201932
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
232 PM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE SLIDING EASTWARD THROUGH QUEBEC WITH A SECOND HIGH
PRESURE CELL OVER THE EASTERN GREAT LAKES AND OHIO VALLEY WILL
KEEP MAINTAIN DRY WEATHER ACROSS CENTRAL PENNSYLVANIA FOR THE REST
OF THIS WEEKEND. AN AMPLIFYING UPPER RIDGE MOVING INTO THE REGION
WILL BRING INCREASING AMOUNTS OF SUNSHINE ON SUNDAY...BUT WILL BE
QUICKLY REPLACED BY A LARGE STORM SYSTEM TRACKING ACROSS THE
CENTRAL UNITED STATES. MOISTURE ASSOCIATED WITH THAT STORM AND
INCREASING EAST FLOW OFF OF THE WESTERN ATLANTIC WILL BRING
INCREASING CLOUDS ON MONDAY...WITH QUITE MILD BUT UNSETTLED
CONDITIONS PREVAILING THROUGH MID WEEK. A VIGOROUS STORM SYSTEM
WILL SWEEP ACROSS THE COMMONWEALTH ON CHRISTMAS EVE BRINGING
WIDESPREAD SHOWERS AND A CHANCE FOR THUNDERSTORMS...FOLLOWED BY
WINDY AND COLDER CONDITIONS WITH SCATTERED SNOW SHOWERS AND
FLURRIES ACROSS THE WEST AND NORTH FOR CHRISTMAS DAY. MILDER
CONDITIONS WILL ARRIVE ONCE AGAIN BY LATE THIS WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
SUBSIDENCE AND DOWNSLOPING OVER MUCH OF THE LAUREL HIGHLANDS AND
PARTS OF THE CENTRAL AND SOUTH CENTRAL MOUNTAINS IS BRINGING SOME
MUCH NEEDED SUNSHINE TO THOSE AREAS. VISIBLE IMAGERY INDICATES THE
NORTHWARD EXTENT PUSHING TOWARDS CENTRAL CLEARFIELD COUNTY AND
SOUTHERN CENTRE COUNTY...AND IT APPEARS LIKELY TO REACH A LITTLE
FARTHER NORTH BEFORE SUNSET.

EXPECT CLOUDS TO FILL BACK IN OVERNIGHT...AS 5H WAVE TRACKS ACROSS
THE OHIO VALLEY AND INTO SOUTHWEST PA BY 12Z SUN. MINS WILL BE
FAIRLY UNIFORM AND RANGE FROM THE LOWER 20S NORTH TO THE UPPER 20S
SOUTHEAST.

&&

.SHORT TERM /SUNDAY/...
DEEP LAYER DRYING BEHIND THE AFOREMENTIONED DEPARTING 5H WAVE AND
UPPER LEVEL RIDGING HAS THE POTENTIAL TO BRING SUNSHINE TO MOST IF
NOT ALL OF CENTRAL PA ON MONDAY. THE STUBBORN STRATUS THAT HAS
PLAGUED US FOR MORE THAN A WEEK WILL HAVE A CHANCE TO MIX
OUT...BUT TRANSITORY SFC HIGH PRESSURE MAY STILL MAKE THIS A SLOW
PROCESS OVER THE NORTH.

PRIOR TO THAT...SOME AREAS COULD PERHAPS SEE A FLURRY IN THE PRE
DAWN HOURS SUNDAY BEFORE THE WAVE QUICKLY EXITS EASTWARD. WENT
CLOSE TO CONSALL GUIDANCE AGAIN WITH MAXES REACHING THE MID TO
UPPER 30S NORTH TO THE LOWER 40S SOUTH.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
INCREASINGLY MOIST SERLY FLOW WILL DEVELOP OFF THE ATLANTIC EARLY
NEXT WEEK IN GRADIENT BTWN RETREATING HIGH OVR NEW ENG AND WEAK
LOW RIDING UP THE E COAST. THE INFLUX OF LOW LVL MOISTURE...COMBINED
WITH OROGRAPHIC LIFT...WILL LIKELY YIELD DAMP AND DRIZZLY WX MON
NITE THROUGH TUESDAY. MDLS HINT AT PERHAPS JUST ENOUGH LOW LVL
COLD AIR FOR AN INITIAL PERIOD OF -FZRA/FZDZ OVR THE HIGHER
TERRAIN OF THE APPALACHIANS MON NITE.

MED RANGE GUIDANCE HAS CONVERGED ON TIMING/TRACK OF DEEP TROUGH
AND ASSOC SFC LOW DURING MID WEEK...ALL OF WHICH POINTS TOWARD A
MILD AND RAINY CHRISTMAS EVE IN WARM SECTOR OF THIS SYSTEM. BLEND
OF MED RANGE GUIDANCE SUPPORTS ARND 1 INCH OF RAIN...FALLING
MOSTLY WITH PASSAGE OF LL JET/PLUME OF ANOMALOUS PWATS WEDNESDAY.
SURGE OF VERY WARM AIR SHOULD PRECEDE THE TRAILING COLD FRONT...PUSHING
READINGS INTO THE 50S OVR MOST OF THE AREA WEDNESDAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS IS LIKELY WED NIGHT INTO THURSDAY OVR THE W MTNS...PERHAPS
BRINGING A WHITE XMAS TO THE ALLEGHENY PLATEAU. THE BIGGER STORY
MAY BE THE STRONG/GUSTY WINDS WED NITE/THURSDAY. DEEPENING SFC
LOWS TRACKING THRU THE E GRT LKS TYPICALLY BRING CENTRAL PA SOME
OF OUR STRONGEST WINDS AND LATEST GUIDANCE SUGGESTS WINDS COULD
BE NEAR ADVISORY CRITERIA ON CHRISTMAS.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
00Z ECENS AND GEFS SHOWING THE UPPER TROF QUICKLY LIFTING OUT BY
FRIDAY.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH SUBSIDENCE
INVERSION THIS MORNING...WITH MVFR CIGS.  LOWER CIGS WILL PERSIST
IN THE NORTHERN MTNS...WITH IMPROVING CIGS CENTRAL AND SOUTH. WINDS
WILL BE LIGHT FROM THE WEST.

CIG RESTRICTIONS IN EXPANDING STRATOCU DECK LIKELY RETURN AGAIN
TONIGHT...THOUGH LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS
PREVIOUS NIGHTS. A SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING
A THICKENING MID-LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO
BE LIGHT...WITH SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW
PRESSURE SYSTEM BEGINS TO DEEPEN OVER THE CENTRAL U.S.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

THU...WINDY AND COLDER WITH SCT MVFR CIGS AND -SHSN.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/EVANEGO
AVIATION...DEVOIR/RXR





000
FXUS61 KCTP 201518
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1018 AM EST SAT DEC 20 2014

.SYNOPSIS...
A HIGH PRESSURE AREA CENTERED OVER THE GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND. A DEEP UPPER TROUGH AND
ASSOCIATED SFC LOW WILL LIFT NORTHEAST THROUGH THE GREAT LAKES
DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SUBSIDENCE INVERSION MAINTAINING THE GLOOMY SKIES THIS MORNING...
WHILE DECAYING MID-UPPER CLOUD FROM UNDERCUTTING SHORTWAVE SOUTH
OF THE MASON DIXON LINE IS LIFTING ACROSS SOUTHWEST AND CENTRAL
AREAS. LITTLE IF ANY SUNSHINE WILL BE SEEN FOR YET ANOTHER
DAY. THIS AND LOW DECEMBER SUN ANGLE WILL RESULT IN HIGHS ONLY
IN THE LOW TO MID 30S MOST PLACES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
NEXT SHORTWAVE...OVR IOWA AT 09Z...WILL TRACK ACROSS THE REGION
TONIGHT. THIS MOISTURE-STARVED FEATURE SHOULD PRODUCE PLENTY OF
MID LVL CLOUDINESS TONIGHT...BUT PROBABLY NO PRECIP DUE TO DRY AIR
IN THE 0-3KM LAYER. STILL...CAN/T RULE OUT A FLURRY IN SPOTS.

IN WAKE OF TONIGHT/S SHORTWAVE...A GOOD DEAL OF SUNSHINE IS
EXPECTED SUNDAY UNDER RIDGING AT SFC AND ALOFT. CONSALL OUTPUT
SUGGESTS MAX TEMPS WILL RANGE FROM THE 30S MOST PLACES...TO THE
L40S ACROSS THE LOWER SUSQ VALLEY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
INCREASINGLY MOIST SERLY FLOW WILL DEVELOP OFF THE ATLANTIC EARLY
NEXT WEEK IN GRADIENT BTWN RETREATING HIGH OVR NEW ENG AND WEAK
LOW RIDING UP THE E COAST. THE INFLUX OF LOW LVL MOISTURE...COMBINED
WITH OROGRAPHIC LIFT...WILL LIKELY YIELD DAMP AND DRIZZLY WX MON
NITE THROUGH TUESDAY. MDLS HINT AT PERHAPS JUST ENOUGH LOW LVL
COLD AIR FOR AN INITIAL PERIOD OF -FZRA/FZDZ OVR THE HIGHER
TERRAIN OF THE APPALACHIANS MON NITE.

MED RANGE GUIDANCE HAS CONVERGED ON TIMING/TRACK OF DEEP TROUGH
AND ASSOC SFC LOW DURING MID WEEK...ALL OF WHICH POINTS TOWARD A
MILD AND RAINY CHRISTMAS EVE IN WARM SECTOR OF THIS SYSTEM. BLEND
OF MED RANGE GUIDANCE SUPPORTS ARND 1 INCH OF RAIN...FALLING
MOSTLY WITH PASSAGE OF LL JET/PLUME OF ANOMALOUS PWATS WEDNESDAY.
SURGE OF VERY WARM AIR SHOULD PRECEDE THE TRAILING COLD FRONT...PUSHING
READINGS INTO THE 50S OVR MOST OF THE AREA WEDNESDAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS IS LIKELY WED NIGHT INTO THURSDAY OVR THE W MTNS...PERHAPS
BRINGING A WHITE XMAS TO THE ALLEGHENY PLATEAU. THE BIGGER STORY
MAY BE THE STRONG/GUSTY WINDS WED NITE/THURSDAY. DEEPENING SFC
LOWS TRACKING THRU THE E GRT LKS TYPICALLY BRING CENTRAL PA SOME
OF OUR STRONGEST WINDS AND LATEST GUIDANCE SUGGESTS WINDS COULD
BE NEAR ADVISORY CRITERIA ON CHRISTMAS.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
00Z ECENS AND GEFS SHOWING THE UPPER TROF QUICKLY LIFTING OUT BY
FRIDAY.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH SUBSIDENCE
INVERSION THIS MORNING...WITH MVFR CIGS.  LOWER CIGS WILL PERSIST
IN THE NORTHERN MTNS...WITH IMPROVING CIGS CENTRAL AND SOUTH. WINDS
WILL BE LIGHT FROM THE WEST.

CIG RESTRICTIONS IN EXPANDING STRATOCU DECK LIKELY RETURN AGAIN
TONIGHT...THOUGH LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS
PREVIOUS NIGHTS. A SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING
A THICKENING MID-LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO
BE LIGHT...WITH SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW
PRESSURE SYSTEM BEGINS TO DEEPEN OVER THE CENTRAL U.S.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/EVANEGO
AVIATION...DEVOIR/RXR




000
FXUS61 KCTP 201518
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1018 AM EST SAT DEC 20 2014

.SYNOPSIS...
A HIGH PRESSURE AREA CENTERED OVER THE GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND. A DEEP UPPER TROUGH AND
ASSOCIATED SFC LOW WILL LIFT NORTHEAST THROUGH THE GREAT LAKES
DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SUBSIDENCE INVERSION MAINTAINING THE GLOOMY SKIES THIS MORNING...
WHILE DECAYING MID-UPPER CLOUD FROM UNDERCUTTING SHORTWAVE SOUTH
OF THE MASON DIXON LINE IS LIFTING ACROSS SOUTHWEST AND CENTRAL
AREAS. LITTLE IF ANY SUNSHINE WILL BE SEEN FOR YET ANOTHER
DAY. THIS AND LOW DECEMBER SUN ANGLE WILL RESULT IN HIGHS ONLY
IN THE LOW TO MID 30S MOST PLACES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
NEXT SHORTWAVE...OVR IOWA AT 09Z...WILL TRACK ACROSS THE REGION
TONIGHT. THIS MOISTURE-STARVED FEATURE SHOULD PRODUCE PLENTY OF
MID LVL CLOUDINESS TONIGHT...BUT PROBABLY NO PRECIP DUE TO DRY AIR
IN THE 0-3KM LAYER. STILL...CAN/T RULE OUT A FLURRY IN SPOTS.

IN WAKE OF TONIGHT/S SHORTWAVE...A GOOD DEAL OF SUNSHINE IS
EXPECTED SUNDAY UNDER RIDGING AT SFC AND ALOFT. CONSALL OUTPUT
SUGGESTS MAX TEMPS WILL RANGE FROM THE 30S MOST PLACES...TO THE
L40S ACROSS THE LOWER SUSQ VALLEY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
INCREASINGLY MOIST SERLY FLOW WILL DEVELOP OFF THE ATLANTIC EARLY
NEXT WEEK IN GRADIENT BTWN RETREATING HIGH OVR NEW ENG AND WEAK
LOW RIDING UP THE E COAST. THE INFLUX OF LOW LVL MOISTURE...COMBINED
WITH OROGRAPHIC LIFT...WILL LIKELY YIELD DAMP AND DRIZZLY WX MON
NITE THROUGH TUESDAY. MDLS HINT AT PERHAPS JUST ENOUGH LOW LVL
COLD AIR FOR AN INITIAL PERIOD OF -FZRA/FZDZ OVR THE HIGHER
TERRAIN OF THE APPALACHIANS MON NITE.

MED RANGE GUIDANCE HAS CONVERGED ON TIMING/TRACK OF DEEP TROUGH
AND ASSOC SFC LOW DURING MID WEEK...ALL OF WHICH POINTS TOWARD A
MILD AND RAINY CHRISTMAS EVE IN WARM SECTOR OF THIS SYSTEM. BLEND
OF MED RANGE GUIDANCE SUPPORTS ARND 1 INCH OF RAIN...FALLING
MOSTLY WITH PASSAGE OF LL JET/PLUME OF ANOMALOUS PWATS WEDNESDAY.
SURGE OF VERY WARM AIR SHOULD PRECEDE THE TRAILING COLD FRONT...PUSHING
READINGS INTO THE 50S OVR MOST OF THE AREA WEDNESDAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS IS LIKELY WED NIGHT INTO THURSDAY OVR THE W MTNS...PERHAPS
BRINGING A WHITE XMAS TO THE ALLEGHENY PLATEAU. THE BIGGER STORY
MAY BE THE STRONG/GUSTY WINDS WED NITE/THURSDAY. DEEPENING SFC
LOWS TRACKING THRU THE E GRT LKS TYPICALLY BRING CENTRAL PA SOME
OF OUR STRONGEST WINDS AND LATEST GUIDANCE SUGGESTS WINDS COULD
BE NEAR ADVISORY CRITERIA ON CHRISTMAS.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
00Z ECENS AND GEFS SHOWING THE UPPER TROF QUICKLY LIFTING OUT BY
FRIDAY.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH SUBSIDENCE
INVERSION THIS MORNING...WITH MVFR CIGS.  LOWER CIGS WILL PERSIST
IN THE NORTHERN MTNS...WITH IMPROVING CIGS CENTRAL AND SOUTH. WINDS
WILL BE LIGHT FROM THE WEST.

CIG RESTRICTIONS IN EXPANDING STRATOCU DECK LIKELY RETURN AGAIN
TONIGHT...THOUGH LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS
PREVIOUS NIGHTS. A SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING
A THICKENING MID-LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO
BE LIGHT...WITH SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW
PRESSURE SYSTEM BEGINS TO DEEPEN OVER THE CENTRAL U.S.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...DEVOIR/FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/EVANEGO
AVIATION...DEVOIR/RXR





000
FXUS61 KCTP 201140
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
640 AM EST SAT DEC 20 2014

.SYNOPSIS...
A HIGH PRESSURE AREA CENTERED OVER THE GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND. A DEEP UPPER TROUGH AND
ASSOCIATED SFC LOW WILL LIFT NORTHEAST THROUGH THE GREAT LAKES
DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK REMAINS TRAPPED
BENEATH SUBSIDENCE INVERSION THIS MORNING. THERE HAS BEEN SOME
CLEARING ACROSS THE SC MTNS EARLY THIS AM. HOWEVER...CIRRUS SHIELD
IN ADVANCE OF APPROACHING SHORTWAVE SHOULD OVERSPREAD THE AREA
BTWN 12Z-14Z.

LACK OF SUNSHINE AND LOW DECEMBER SUN ANGLE WILL RESULT IN TEMPS
RISING LITTLE FROM AM LOWS...WITH HIGHS IN THE LOW TO MID 30S
MOST PLACES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
NEXT SHORTWAVE...OVR IOWA AT 09Z...WILL TRACK ACROSS THE REGION
TONIGHT. THIS MOISTURE-STARVED FEATURE SHOULD PRODUCE PLENTY OF
MID LVL CLOUDINESS TONIGHT...BUT PROBABLY NO PRECIP DUE TO DRY AIR
IN THE 0-3KM LAYER. STILL...CAN/T RULE OUT A FLURRY IN SPOTS.

IN WAKE OF TONIGHT/S SHORTWAVE...A GOOD DEAL OF SUNSHINE IS
EXPECTED SUNDAY UNDER RIDGING AT SFC AND ALOFT. CONSALL OUTPUT
SUGGESTS MAX TEMPS WILL RANGE FROM THE 30S MOST PLACES...TO THE
L40S ACROSS THE LOWER SUSQ VALLEY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
INCREASINGLY MOIST SERLY FLOW WILL DEVELOP OFF THE ATLANTIC EARLY
NEXT WEEK IN GRADIENT BTWN RETREATING HIGH OVR NEW ENG AND WEAK
LOW RIDING UP THE E COAST. THE INFLUX OF LOW LVL MOISTURE...COMBINED
WITH OROGRAPHIC LIFT...WILL LIKELY YIELD DAMP AND DRIZZLY WX MON
NITE THROUGH TUESDAY. MDLS HINT AT PERHAPS JUST ENOUGH LOW LVL
COLD AIR FOR AN INITIAL PERIOD OF -FZRA/FZDZ OVR THE HIGHER
TERRAIN OF THE APPALACHIANS MON NITE.

MED RANGE GUIDANCE HAS CONVERGED ON TIMING/TRACK OF DEEP TROUGH
AND ASSOC SFC LOW DURING MID WEEK...ALL OF WHICH POINTS TOWARD A
MILD AND RAINY CHRISTMAS EVE IN WARM SECTOR OF THIS SYSTEM. BLEND
OF MED RANGE GUIDANCE SUPPORTS ARND 1 INCH OF RAIN...FALLING
MOSTLY WITH PASSAGE OF LL JET/PLUME OF ANOMALOUS PWATS WEDNESDAY.
SURGE OF VERY WARM AIR SHOULD PRECEDE THE TRAILING COLD FRONT...PUSHING
READINGS INTO THE 50S OVR MOST OF THE AREA WEDNESDAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS IS LIKELY WED NIGHT INTO THURSDAY OVR THE W MTNS...PERHAPS
BRINGING A WHITE XMAS TO THE ALLEGHENY PLATEAU. THE BIGGER STORY
MAY BE THE STRONG/GUSTY WINDS WED NITE/THURSDAY. DEEPENING SFC
LOWS TRACKING THRU THE E GRT LKS TYPICALLY BRING CENTRAL PA SOME
OF OUR STRONGEST WINDS AND LATEST GUIDANCE SUGGESTS WINDS COULD
BE NEAR ADVISORY CRITERIA ON CHRISTMAS.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
00Z ECENS AND GEFS SHOWING THE UPPER TROF QUICKLY LIFTING OUT BY
FRIDAY.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
A HIGH PRESSURE AREA CENTERED OVER THE GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND.

SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH SUBSIDENCE
INVERSION THIS MORNING...THOUGH THERE HAS BEEN SOME CLEARING
ACROSS THE SC MTNS OVER THE PAST SEVERAL HOURS. MUCH OF THE REGION
REMAINS MVFR AT 12Z /WITH THE NW MTNS AND KBFD SLIPPING TO IFR
CIGS OCCASIONALLY/. CIGS SHOULD IMPROVE IN MOST PLACES BY LATE
MORNING...BUT LOWER CIGS WILL PERSIST IN THE NORTHERN MTNS. HIGH
CLOUDS INCREASE LATER THIS MORNING AS WAA ALOFT OVERSPREADS THE
AREA IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE OHIO VALLEY. WINDS
WILL BE LIGHT FROM THE WEST.

CIG RESTRICTIONS IN EXPANDING STRATOCU DECK LIKELY RETURN AGAIN
TONIGHT...THOUGH LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS
PREVIOUS NIGHTS. A SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING
A THICKENING MID-LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO
BE LIGHT...WITH SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW
PRESSURE SYSTEM BEGINS TO DEEPEN OVER THE CENTRAL U.S.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/EVANEGO
AVIATION...RXR




000
FXUS61 KCTP 201140
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
640 AM EST SAT DEC 20 2014

.SYNOPSIS...
A HIGH PRESSURE AREA CENTERED OVER THE GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND. A DEEP UPPER TROUGH AND
ASSOCIATED SFC LOW WILL LIFT NORTHEAST THROUGH THE GREAT LAKES
DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK REMAINS TRAPPED
BENEATH SUBSIDENCE INVERSION THIS MORNING. THERE HAS BEEN SOME
CLEARING ACROSS THE SC MTNS EARLY THIS AM. HOWEVER...CIRRUS SHIELD
IN ADVANCE OF APPROACHING SHORTWAVE SHOULD OVERSPREAD THE AREA
BTWN 12Z-14Z.

LACK OF SUNSHINE AND LOW DECEMBER SUN ANGLE WILL RESULT IN TEMPS
RISING LITTLE FROM AM LOWS...WITH HIGHS IN THE LOW TO MID 30S
MOST PLACES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
NEXT SHORTWAVE...OVR IOWA AT 09Z...WILL TRACK ACROSS THE REGION
TONIGHT. THIS MOISTURE-STARVED FEATURE SHOULD PRODUCE PLENTY OF
MID LVL CLOUDINESS TONIGHT...BUT PROBABLY NO PRECIP DUE TO DRY AIR
IN THE 0-3KM LAYER. STILL...CAN/T RULE OUT A FLURRY IN SPOTS.

IN WAKE OF TONIGHT/S SHORTWAVE...A GOOD DEAL OF SUNSHINE IS
EXPECTED SUNDAY UNDER RIDGING AT SFC AND ALOFT. CONSALL OUTPUT
SUGGESTS MAX TEMPS WILL RANGE FROM THE 30S MOST PLACES...TO THE
L40S ACROSS THE LOWER SUSQ VALLEY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
INCREASINGLY MOIST SERLY FLOW WILL DEVELOP OFF THE ATLANTIC EARLY
NEXT WEEK IN GRADIENT BTWN RETREATING HIGH OVR NEW ENG AND WEAK
LOW RIDING UP THE E COAST. THE INFLUX OF LOW LVL MOISTURE...COMBINED
WITH OROGRAPHIC LIFT...WILL LIKELY YIELD DAMP AND DRIZZLY WX MON
NITE THROUGH TUESDAY. MDLS HINT AT PERHAPS JUST ENOUGH LOW LVL
COLD AIR FOR AN INITIAL PERIOD OF -FZRA/FZDZ OVR THE HIGHER
TERRAIN OF THE APPALACHIANS MON NITE.

MED RANGE GUIDANCE HAS CONVERGED ON TIMING/TRACK OF DEEP TROUGH
AND ASSOC SFC LOW DURING MID WEEK...ALL OF WHICH POINTS TOWARD A
MILD AND RAINY CHRISTMAS EVE IN WARM SECTOR OF THIS SYSTEM. BLEND
OF MED RANGE GUIDANCE SUPPORTS ARND 1 INCH OF RAIN...FALLING
MOSTLY WITH PASSAGE OF LL JET/PLUME OF ANOMALOUS PWATS WEDNESDAY.
SURGE OF VERY WARM AIR SHOULD PRECEDE THE TRAILING COLD FRONT...PUSHING
READINGS INTO THE 50S OVR MOST OF THE AREA WEDNESDAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS IS LIKELY WED NIGHT INTO THURSDAY OVR THE W MTNS...PERHAPS
BRINGING A WHITE XMAS TO THE ALLEGHENY PLATEAU. THE BIGGER STORY
MAY BE THE STRONG/GUSTY WINDS WED NITE/THURSDAY. DEEPENING SFC
LOWS TRACKING THRU THE E GRT LKS TYPICALLY BRING CENTRAL PA SOME
OF OUR STRONGEST WINDS AND LATEST GUIDANCE SUGGESTS WINDS COULD
BE NEAR ADVISORY CRITERIA ON CHRISTMAS.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
00Z ECENS AND GEFS SHOWING THE UPPER TROF QUICKLY LIFTING OUT BY
FRIDAY.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
A HIGH PRESSURE AREA CENTERED OVER THE GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND.

SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH SUBSIDENCE
INVERSION THIS MORNING...THOUGH THERE HAS BEEN SOME CLEARING
ACROSS THE SC MTNS OVER THE PAST SEVERAL HOURS. MUCH OF THE REGION
REMAINS MVFR AT 12Z /WITH THE NW MTNS AND KBFD SLIPPING TO IFR
CIGS OCCASIONALLY/. CIGS SHOULD IMPROVE IN MOST PLACES BY LATE
MORNING...BUT LOWER CIGS WILL PERSIST IN THE NORTHERN MTNS. HIGH
CLOUDS INCREASE LATER THIS MORNING AS WAA ALOFT OVERSPREADS THE
AREA IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE OHIO VALLEY. WINDS
WILL BE LIGHT FROM THE WEST.

CIG RESTRICTIONS IN EXPANDING STRATOCU DECK LIKELY RETURN AGAIN
TONIGHT...THOUGH LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS
PREVIOUS NIGHTS. A SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING
A THICKENING MID-LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO
BE LIGHT...WITH SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW
PRESSURE SYSTEM BEGINS TO DEEPEN OVER THE CENTRAL U.S.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/EVANEGO
AVIATION...RXR





000
FXUS61 KCTP 201122
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
622 AM EST SAT DEC 20 2014

.SYNOPSIS...
A HIGH PRESSURE AREA CENTERED OVER THE GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND. A DEEP UPPER TROUGH AND
ASSOCIATED SFC LOW WILL LIFT NORTHEAST THROUGH THE GREAT LAKES
DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK REMAINS TRAPPED
BENEATH SUBSIDENCE INVERSION THIS MORNING. THERE HAS BEEN SOME
CLEARING ACROSS THE SC MTNS AND NR TERM MDL SOUNDINGS INDICATE
THIS AREA WILL REMAIN MCLEAR THRU DAWN...WHILE STRATOCU PERSISTS
ELSEWHERE. EARLY SUNSHINE IN THE SOUTH WILL FADE BENEATH INCREASING
HIGH CLOUDS LATER THIS MORNING...AS WAA ALOFT OVERSPREADS THE AREA
IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE OHIO VALLEY.

LACK OF SUNSHINE AND LOW DECEMBER SUN ANGLE WILL RESULT IN TEMPS
RISING LITTLE FROM AM LOWS...WITH HIGHS IN THE LOW TO MID 30S
MOST PLACES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
NEXT SHORTWAVE...OVR IOWA AT 09Z...WILL TRACK ACROSS THE REGION
TONIGHT. THIS MOISTURE-STARVED FEATURE SHOULD PRODUCE PLENTY OF
MID LVL CLOUDINESS TONIGHT...BUT PROBABLY NO PRECIP DUE TO DRY AIR
IN THE 0-3KM LAYER. STILL...CAN/T RULE OUT A FLURRY IN SPOTS.

IN WAKE OF TONIGHT/S SHORTWAVE...A GOOD DEAL OF SUNSHINE IS
EXPECTED SUNDAY UNDER RIDGING AT SFC AND ALOFT. CONSALL OUTPUT
SUGGESTS MAX TEMPS WILL RANGE FROM THE 30S MOST PLACES...TO THE
L40S ACROSS THE LOWER SUSQ VALLEY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
INCREASINGLY MOIST SERLY FLOW WILL DEVELOP OFF THE ATLANTIC EARLY
NEXT WEEK IN GRADIENT BTWN RETREATING HIGH OVR NEW ENG AND WEAK
LOW RIDING UP THE E COAST. THE INFLUX OF LOW LVL MOISTURE...COMBINED
WITH OROGRAPHIC LIFT...WILL LIKELY YIELD DAMP AND DRIZZLY WX MON
NITE THROUGH TUESDAY. MDLS HINT AT PERHAPS JUST ENOUGH LOW LVL
COLD AIR FOR AN INITIAL PERIOD OF -FZRA/FZDZ OVR THE HIGHER
TERRAIN OF THE APPALACHIANS MON NITE.

MED RANGE GUIDANCE HAS CONVERGED ON TIMING/TRACK OF DEEP TROUGH
AND ASSOC SFC LOW DURING MID WEEK...ALL OF WHICH POINTS TOWARD A
MILD AND RAINY CHRISTMAS EVE IN WARM SECTOR OF THIS SYSTEM. BLEND
OF MED RANGE GUIDANCE SUPPORTS ARND 1 INCH OF RAIN...FALLING
MOSTLY WITH PASSAGE OF LL JET/PLUME OF ANOMALOUS PWATS WEDNESDAY.
SURGE OF VERY WARM AIR SHOULD PRECEDE THE TRAILING COLD FRONT...PUSHING
READINGS INTO THE 50S OVR MOST OF THE AREA WEDNESDAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS IS LIKELY WED NIGHT INTO THURSDAY OVR THE W MTNS...PERHAPS
BRINGING A WHITE XMAS TO THE ALLEGHENY PLATEAU. THE BIGGER STORY
MAY BE THE STRONG/GUSTY WINDS WED NITE/THURSDAY. DEEPENING SFC
LOWS TRACKING THRU THE E GRT LKS TYPICALLY BRING CENTRAL PA SOME
OF OUR STRONGEST WINDS AND LATEST GUIDANCE SUGGESTS WINDS COULD
BE NEAR ADVISORY CRITERIA ON CHRISTMAS.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
00Z ECENS AND GEFS SHOWING THE UPPER TROF QUICKLY LIFTING OUT BY
FRIDAY.

&&

.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
A HIGH PRESSURE AREA CENTERED OVER THE GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND.

SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH SUBSIDENCE
INVERSION THIS MORNING...THOUGH THERE HAS BEEN SOME CLEARING
ACROSS THE SC MTNS OVER THE PAST SEVERAL HOURS. MUCH OF THE REGION
REMAINS MVFR AT 12Z /WITH THE NW MTNS AND KBFD SLIPPING TO IFR
CIGS OCCASIONALLY/. CIGS SHOULD IMPROVE IN MOST PLACES BY LATE
MORNING...BUT LOWER CIGS WILL PERSIST IN THE NORTHERN MTNS. HIGH
CLOUDS INCREASE LATER THIS MORNING AS WAA ALOFT OVERSPREADS THE
AREA IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE OHIO VALLEY. WINDS
WILL BE LIGHT FROM THE WEST.

CIG RESTRICTIONS IN EXPANDING STRATOCU DECK LIKELY RETURN AGAIN
TONIGHT...THOUGH LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS
PREVIOUS NIGHTS. A SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING
A THICKENING MID-LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO
BE LIGHT...WITH SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW
PRESSURE SYSTEM BEGINS TO DEEPEN OVER THE CENTRAL U.S.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/EVANEGO
AVIATION...RXR




000
FXUS61 KCTP 201122
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
622 AM EST SAT DEC 20 2014

.SYNOPSIS...
A HIGH PRESSURE AREA CENTERED OVER THE GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND. A DEEP UPPER TROUGH AND
ASSOCIATED SFC LOW WILL LIFT NORTHEAST THROUGH THE GREAT LAKES
DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK REMAINS TRAPPED
BENEATH SUBSIDENCE INVERSION THIS MORNING. THERE HAS BEEN SOME
CLEARING ACROSS THE SC MTNS AND NR TERM MDL SOUNDINGS INDICATE
THIS AREA WILL REMAIN MCLEAR THRU DAWN...WHILE STRATOCU PERSISTS
ELSEWHERE. EARLY SUNSHINE IN THE SOUTH WILL FADE BENEATH INCREASING
HIGH CLOUDS LATER THIS MORNING...AS WAA ALOFT OVERSPREADS THE AREA
IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE OHIO VALLEY.

LACK OF SUNSHINE AND LOW DECEMBER SUN ANGLE WILL RESULT IN TEMPS
RISING LITTLE FROM AM LOWS...WITH HIGHS IN THE LOW TO MID 30S
MOST PLACES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
NEXT SHORTWAVE...OVR IOWA AT 09Z...WILL TRACK ACROSS THE REGION
TONIGHT. THIS MOISTURE-STARVED FEATURE SHOULD PRODUCE PLENTY OF
MID LVL CLOUDINESS TONIGHT...BUT PROBABLY NO PRECIP DUE TO DRY AIR
IN THE 0-3KM LAYER. STILL...CAN/T RULE OUT A FLURRY IN SPOTS.

IN WAKE OF TONIGHT/S SHORTWAVE...A GOOD DEAL OF SUNSHINE IS
EXPECTED SUNDAY UNDER RIDGING AT SFC AND ALOFT. CONSALL OUTPUT
SUGGESTS MAX TEMPS WILL RANGE FROM THE 30S MOST PLACES...TO THE
L40S ACROSS THE LOWER SUSQ VALLEY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
INCREASINGLY MOIST SERLY FLOW WILL DEVELOP OFF THE ATLANTIC EARLY
NEXT WEEK IN GRADIENT BTWN RETREATING HIGH OVR NEW ENG AND WEAK
LOW RIDING UP THE E COAST. THE INFLUX OF LOW LVL MOISTURE...COMBINED
WITH OROGRAPHIC LIFT...WILL LIKELY YIELD DAMP AND DRIZZLY WX MON
NITE THROUGH TUESDAY. MDLS HINT AT PERHAPS JUST ENOUGH LOW LVL
COLD AIR FOR AN INITIAL PERIOD OF -FZRA/FZDZ OVR THE HIGHER
TERRAIN OF THE APPALACHIANS MON NITE.

MED RANGE GUIDANCE HAS CONVERGED ON TIMING/TRACK OF DEEP TROUGH
AND ASSOC SFC LOW DURING MID WEEK...ALL OF WHICH POINTS TOWARD A
MILD AND RAINY CHRISTMAS EVE IN WARM SECTOR OF THIS SYSTEM. BLEND
OF MED RANGE GUIDANCE SUPPORTS ARND 1 INCH OF RAIN...FALLING
MOSTLY WITH PASSAGE OF LL JET/PLUME OF ANOMALOUS PWATS WEDNESDAY.
SURGE OF VERY WARM AIR SHOULD PRECEDE THE TRAILING COLD FRONT...PUSHING
READINGS INTO THE 50S OVR MOST OF THE AREA WEDNESDAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS IS LIKELY WED NIGHT INTO THURSDAY OVR THE W MTNS...PERHAPS
BRINGING A WHITE XMAS TO THE ALLEGHENY PLATEAU. THE BIGGER STORY
MAY BE THE STRONG/GUSTY WINDS WED NITE/THURSDAY. DEEPENING SFC
LOWS TRACKING THRU THE E GRT LKS TYPICALLY BRING CENTRAL PA SOME
OF OUR STRONGEST WINDS AND LATEST GUIDANCE SUGGESTS WINDS COULD
BE NEAR ADVISORY CRITERIA ON CHRISTMAS.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
00Z ECENS AND GEFS SHOWING THE UPPER TROF QUICKLY LIFTING OUT BY
FRIDAY.

&&

.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
A HIGH PRESSURE AREA CENTERED OVER THE GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND.

SHALLOW STRATOCU DECK REMAINS TRAPPED BENEATH SUBSIDENCE
INVERSION THIS MORNING...THOUGH THERE HAS BEEN SOME CLEARING
ACROSS THE SC MTNS OVER THE PAST SEVERAL HOURS. MUCH OF THE REGION
REMAINS MVFR AT 12Z /WITH THE NW MTNS AND KBFD SLIPPING TO IFR
CIGS OCCASIONALLY/. CIGS SHOULD IMPROVE IN MOST PLACES BY LATE
MORNING...BUT LOWER CIGS WILL PERSIST IN THE NORTHERN MTNS. HIGH
CLOUDS INCREASE LATER THIS MORNING AS WAA ALOFT OVERSPREADS THE
AREA IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE OHIO VALLEY. WINDS
WILL BE LIGHT FROM THE WEST.

CIG RESTRICTIONS IN EXPANDING STRATOCU DECK LIKELY RETURN AGAIN
TONIGHT...THOUGH LOW CLOUDS SHOULD NOT BE QUITE AS EXPANSIVE AS
PREVIOUS NIGHTS. A SHORTWAVE WILL TRACK ACROSS THE REGION BRINGING
A THICKENING MID-LVL DECK AS WELL. SURFACE WINDS WILL CONTINUE TO
BE LIGHT...WITH SW FLOW ALOFT BEGINNING TO INCREASE AS A LARGE LOW
PRESSURE SYSTEM BEGINS TO DEEPEN OVER THE CENTRAL U.S.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/EVANEGO
AVIATION...RXR





000
FXUS61 KCTP 201024
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
524 AM EST SAT DEC 20 2014

.SYNOPSIS...
A HIGH PRESSURE CENTERED OVER THE GREAT LAKES WILL SLIDE EAST
ACROSS PENNSYLVANIA THIS WEEKEND. A DEEP UPPER TROUGH AND
ASSOCIATED SFC LOW WILL LIFT NORTHEAST THROUGH THE GREAT LAKES
DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK REMAINS TRAPPED
BENEATH SUBSIDENCE INVERSION THIS MORNING. THERE HAS BEEN SOME
CLEARING ACROSS THE SC MTNS AND NR TERM MDL SOUNDINGS INDICATE
THIS AREA WILL REMAIN MCLEAR THRU DAWN...WHILE STRATOCU PERSISTS
ELSEWHERE. EARLY SUNSHINE IN THE SOUTH WILL FADE BENEATH INCREASING
HIGH CLOUDS LATER THIS MORNING...AS WAA ALOFT OVERSPREADS THE AREA
IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE OHIO VALLEY.

LACK OF SUNSHINE AND LOW DECEMBER SUN ANGLE WILL RESULT IN TEMPS
RISING LITTLE FROM AM LOWS...WITH HIGHS IN THE LOW TO MID 30S
MOST PLACES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
NEXT SHORTWAVE...OVR IOWA AT 09Z...WILL TRACK ACROSS THE REGION
TONIGHT. THIS MOISTURE-STARVED FEATURE SHOULD PRODUCE PLENTY OF
MID LVL CLOUDINESS TONIGHT...BUT PROBABLY NO PRECIP DUE TO DRY AIR
IN THE 0-3KM LAYER. STILL...CAN/T RULE OUT A FLURRY IN SPOTS.

IN WAKE OF TONIGHT/S SHORTWAVE...A GOOD DEAL OF SUNSHINE IS
EXPECTED SUNDAY UNDER RIDGING AT SFC AND ALOFT. CONSALL OUTPUT
SUGGESTS MAX TEMPS WILL RANGE FROM THE 30S MOST PLACES...TO THE
L40S ACROSS THE LOWER SUSQ VALLEY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
INCREASINGLY MOIST SERLY FLOW WILL DEVELOP OFF THE ATLANTIC EARLY
NEXT WEEK IN GRADIENT BTWN RETREATING HIGH OVR NEW ENG AND WEAK
LOW RIDING UP THE E COAST. THE INFLUX OF LOW LVL MOISTURE...COMBINED
WITH OROGRAPHIC LIFT...WILL LIKELY YIELD DAMP AND DRIZZLY WX MON
NITE THROUGH TUESDAY. MDLS HINT AT PERHAPS JUST ENOUGH LOW LVL
COLD AIR FOR AN INITIAL PERIOD OF -FZRA/FZDZ OVR THE HIGHER
TERRAIN OF THE APPALACHIANS MON NITE.

MED RANGE GUIDANCE HAS CONVERGED ON TIMING/TRACK OF DEEP TROUGH
AND ASSOC SFC LOW DURING MID WEEK...ALL OF WHICH POINTS TOWARD A
MILD AND RAINY CHRISTMAS EVE IN WARM SECTOR OF THIS SYSTEM. BLEND
OF MED RANGE GUIDANCE SUPPORTS ARND 1 INCH OF RAIN...FALLING
MOSTLY WITH PASSAGE OF LL JET/PLUME OF ANOMALOUS PWATS WEDNESDAY.
SURGE OF VERY WARM AIR SHOULD PRECEDE THE TRAILING COLD FRONT...PUSHING
READINGS INTO THE 50S OVR MOST OF THE AREA WEDNESDAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS IS LIKELY WED NIGHT INTO THURSDAY OVR THE W MTNS...PERHAPS
BRINGING A WHITE XMAS TO THE ALLEGHENY PLATEAU. THE BIGGER STORY
MAY BE THE STRONG/GUSTY WINDS WED NITE/THURSDAY. DEEPENING SFC
LOWS TRACKING THRU THE E GRT LKS TYPICALLY BRING CENTRAL PA SOME
OF OUR STRONGEST WINDS AND LATEST GUIDANCE SUGGESTS WINDS COULD
BE NEAR ADVISORY CRITERIA ON CHRISTMAS.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
00Z ECENS AND GEFS SHOWING THE UPPER TROF QUICKLY LIFTING OUT BY
FRIDAY.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
NORTHWESTERLY SFC FLOW THAT HAS CAUSED OROGRAPHIC FORCING OF A
SHALLOW MOIST LAYER WILL CONTINUE TO PRODUCE PLENTY OF CLOUDS
ACROSS THE NW AND THE LAURELS WITH MAINLY MVFR BKN-OVC CIGS
THROUGH TONIGHT. KJST AND KBFD WILL TREND IFR THROUGH 12Z...AND
CIGS WILL SLOWLY INCREASE AS THE LOW LEVELS DRY OUT BY MID TO LATE
TOMORROW MORNING. IN CONTRAST...THE SE PENN AIRFIELDS SUCH AS
KMDT...KTHV AND KLNS WILL SEE MAINLY VFR.

NORTHWEST WINDS OF 10-15 KTS WITH HIGHER GUSTS WILL DECREASE TO 8
KTS OR LESS LATER TONIGHT AND SATURDAY.

HIGH PRESSURE BUILDS EAST ACROSS PENN SATURDAY...WITH BKN-OVC CIGS
VARYING BETWEEN MVFR OVER THE HIGHER TERRAIN OF THE NORTH AND
WEST...TO SCT-BKN VFR IN THE VALLEYS.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/EVANEGO
AVIATION...LAMBERT/CERU





000
FXUS61 KCTP 201024
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
524 AM EST SAT DEC 20 2014

.SYNOPSIS...
A HIGH PRESSURE CENTERED OVER THE GREAT LAKES WILL SLIDE EAST
ACROSS PENNSYLVANIA THIS WEEKEND. A DEEP UPPER TROUGH AND
ASSOCIATED SFC LOW WILL LIFT NORTHEAST THROUGH THE GREAT LAKES
DURING THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK REMAINS TRAPPED
BENEATH SUBSIDENCE INVERSION THIS MORNING. THERE HAS BEEN SOME
CLEARING ACROSS THE SC MTNS AND NR TERM MDL SOUNDINGS INDICATE
THIS AREA WILL REMAIN MCLEAR THRU DAWN...WHILE STRATOCU PERSISTS
ELSEWHERE. EARLY SUNSHINE IN THE SOUTH WILL FADE BENEATH INCREASING
HIGH CLOUDS LATER THIS MORNING...AS WAA ALOFT OVERSPREADS THE AREA
IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE OHIO VALLEY.

LACK OF SUNSHINE AND LOW DECEMBER SUN ANGLE WILL RESULT IN TEMPS
RISING LITTLE FROM AM LOWS...WITH HIGHS IN THE LOW TO MID 30S
MOST PLACES.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
NEXT SHORTWAVE...OVR IOWA AT 09Z...WILL TRACK ACROSS THE REGION
TONIGHT. THIS MOISTURE-STARVED FEATURE SHOULD PRODUCE PLENTY OF
MID LVL CLOUDINESS TONIGHT...BUT PROBABLY NO PRECIP DUE TO DRY AIR
IN THE 0-3KM LAYER. STILL...CAN/T RULE OUT A FLURRY IN SPOTS.

IN WAKE OF TONIGHT/S SHORTWAVE...A GOOD DEAL OF SUNSHINE IS
EXPECTED SUNDAY UNDER RIDGING AT SFC AND ALOFT. CONSALL OUTPUT
SUGGESTS MAX TEMPS WILL RANGE FROM THE 30S MOST PLACES...TO THE
L40S ACROSS THE LOWER SUSQ VALLEY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
INCREASINGLY MOIST SERLY FLOW WILL DEVELOP OFF THE ATLANTIC EARLY
NEXT WEEK IN GRADIENT BTWN RETREATING HIGH OVR NEW ENG AND WEAK
LOW RIDING UP THE E COAST. THE INFLUX OF LOW LVL MOISTURE...COMBINED
WITH OROGRAPHIC LIFT...WILL LIKELY YIELD DAMP AND DRIZZLY WX MON
NITE THROUGH TUESDAY. MDLS HINT AT PERHAPS JUST ENOUGH LOW LVL
COLD AIR FOR AN INITIAL PERIOD OF -FZRA/FZDZ OVR THE HIGHER
TERRAIN OF THE APPALACHIANS MON NITE.

MED RANGE GUIDANCE HAS CONVERGED ON TIMING/TRACK OF DEEP TROUGH
AND ASSOC SFC LOW DURING MID WEEK...ALL OF WHICH POINTS TOWARD A
MILD AND RAINY CHRISTMAS EVE IN WARM SECTOR OF THIS SYSTEM. BLEND
OF MED RANGE GUIDANCE SUPPORTS ARND 1 INCH OF RAIN...FALLING
MOSTLY WITH PASSAGE OF LL JET/PLUME OF ANOMALOUS PWATS WEDNESDAY.
SURGE OF VERY WARM AIR SHOULD PRECEDE THE TRAILING COLD FRONT...PUSHING
READINGS INTO THE 50S OVR MOST OF THE AREA WEDNESDAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS IS LIKELY WED NIGHT INTO THURSDAY OVR THE W MTNS...PERHAPS
BRINGING A WHITE XMAS TO THE ALLEGHENY PLATEAU. THE BIGGER STORY
MAY BE THE STRONG/GUSTY WINDS WED NITE/THURSDAY. DEEPENING SFC
LOWS TRACKING THRU THE E GRT LKS TYPICALLY BRING CENTRAL PA SOME
OF OUR STRONGEST WINDS AND LATEST GUIDANCE SUGGESTS WINDS COULD
BE NEAR ADVISORY CRITERIA ON CHRISTMAS.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
00Z ECENS AND GEFS SHOWING THE UPPER TROF QUICKLY LIFTING OUT BY
FRIDAY.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
NORTHWESTERLY SFC FLOW THAT HAS CAUSED OROGRAPHIC FORCING OF A
SHALLOW MOIST LAYER WILL CONTINUE TO PRODUCE PLENTY OF CLOUDS
ACROSS THE NW AND THE LAURELS WITH MAINLY MVFR BKN-OVC CIGS
THROUGH TONIGHT. KJST AND KBFD WILL TREND IFR THROUGH 12Z...AND
CIGS WILL SLOWLY INCREASE AS THE LOW LEVELS DRY OUT BY MID TO LATE
TOMORROW MORNING. IN CONTRAST...THE SE PENN AIRFIELDS SUCH AS
KMDT...KTHV AND KLNS WILL SEE MAINLY VFR.

NORTHWEST WINDS OF 10-15 KTS WITH HIGHER GUSTS WILL DECREASE TO 8
KTS OR LESS LATER TONIGHT AND SATURDAY.

HIGH PRESSURE BUILDS EAST ACROSS PENN SATURDAY...WITH BKN-OVC CIGS
VARYING BETWEEN MVFR OVER THE HIGHER TERRAIN OF THE NORTH AND
WEST...TO SCT-BKN VFR IN THE VALLEYS.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/EVANEGO
AVIATION...LAMBERT/CERU




000
FXUS61 KCTP 200636
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
136 AM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE WESTERN GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND...BRINGING DRY WEATHER WITH
LIGHTER WIND. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK
LIKELY BRINGING US RAIN AND WIND FOR CHRISTMAS EVE...THEN BLUSTERY
AND COLDER CONDITIONS FOR CHRISTMAS DAY WITH SCATTERED SNOW
SHOWERS.

&&

.NEAR TERM /UNTIL 8 AM THIS MORNING/...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK TRAPPED BELOW A
MODERATELY STRONG SUBSIDENCE INVERSION /BASED AT AROUND 2-3KFT
AGL/ WILL PERSIST ACROSS MUCH OF CENTRAL PENNSYLVANIA EARLY THIS
MORNING. APPROACH OF SFC HIGH AND FALLING INVERSION HGT HAS
RESULTED IN PARTIAL CLEARING ACROSS THE SC MTNS AND NR TERM MDL
SOUNDINGS INDICATE THIS AREA WILL REMAIN MCLEAR THRU DAWN...WHILE
STRATOCU PERSISTS ELSEWHERE. TEMPS ON TRACK TO BOTTOM OUT IN THE
20S.

&&

.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SUNDAY/...
A RIDGE OF HIGH PRESSURE...LIGHTER WIND...AND ASSOC DRIER AIR
MASS WILL BUILD EAST ACROSS THE STATE SATURDAY...PROVIDING THE
AREA WITH FAIR WEATHER.

HIGH RES MODEL DATA CONTINUES TO PAINT A MOSTLY CLOUDY PICTURE FOR
MUCH OF THE REGION SATURDAY INTO SATURDAY NIGHT...THOUGH PERIODS
OF SUNSHINE ARE LIKELY THROUGHOUT THE CENTRAL RIDGE AND VALLEY
REGION...AND SUSQUEHANNA RIVER VALLEY.

WAA ALOFT IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE MISS VALLEY
WILL LIKELY SPREAD SOME THIN CIRRUS OVER THE LOWER/THIN STRATO CU
CLOUD DECK PRESENT ACROSS THE REGION SATURDAY. ALL 12Z OPERATIONAL
MODEL DATA CONTINUES TO SUPPORT A DRY DAY WITH SFC RIDGE AND LOW
PWAT AIRMASS OVR THE STATE. MAX TEMPS SHOULD BE FAIRLY CLOSE TO
SEASONAL NORMS NEAR 30 ACROSS THE MTNS...AND MID TO UPPER 30S IN
THE SE.

MOSTLY CLOUDY SKIES WITH LIGHT WIND SAT NIGHT WILL YIELD LOWS IN
THE LOWER 20S ACROSS THE MTNS...AND GENERALLY THE MID 20S
ELSEWHERE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGH PRES WILL PROVIDE TRANQUIL WEATHER ON SUNDAY...WITH PARTLY TO
MOSTLY SUNNY SKIES AND SEASONABLE TEMPS. AFTER THAT...THE WEATHER
WILL BECOME INCREASINGLY UNSETTLED AS NEXT WEEK PROGRESSES.

CLOUDS WILL INCR SUNDAY NIGHT INTO MONDAY...AS HIGH PRES LOSES
ITS GRIP AND A WEAK AREA OF LOW PRES ORGANIZES OVER THE SERN UNITED
STATES. LIGHT PRECIP WILL WORK NWD INTO PENNSYLVANIA LATE MONDAY
INTO MONDAY NIGHT AND CONTINUE INTO TUES. INITIALLY...CONDS WILL
BE COLD ENOUGH FOR THE POSSIBILITY OF SOME WINTRY PRECIP.
HOWEVER...WARMER AIR WILL MAKE ITS WAY NWD LATER MONDAY NIGHT INTO
TUES AND GRADUALLY CHANGE ANY LINGERING PRECIP OVER TO PLAIN RAIN.

A MORE SIGNIFICANT STORM SYSTEM WILL GET ORGANIZED OVER THE
MISSISSIPPI VALLEY TUES NIGHT BEFORE PUSHING NWD INTO THE GREAT
LAKES ON WED. THIS SYSTEM WILL DRAW EVEN MILDER AIR NWD INTO THE
REGION...AND PROVIDE A RAINY AND BREEZY CHRISTMAS EVE DAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS FROM WEST TO EAST ACROSS PA IS POSSIBLE LATE WED/WED
NIGHT. SCT SNOW SHOWERS WILL CONTINUE INTO THURS ACROSS MAINLY
NRN AND WRN PA.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
OPERATIONAL MODELS AND THE GEFS SHOWING 850HPA TEMPS ALREADY
BEGINNING TO RISE NEXT FRI.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
NORTHWESTERLY SFC FLOW THAT HAS CAUSED OROGRAPHIC FORCING OF A
SHALLOW MOIST LAYER WILL CONTINUE TO PRODUCE PLENTY OF CLOUDS
ACROSS THE NW AND THE LAURELS WITH MAINLY MVFR BKN-OVC CIGS
THROUGH TONIGHT. KJST AND KBFD WILL TREND IFR THROUGH 12Z...AND
CIGS WILL SLOWLY INCREASE AS THE LOW LEVELS DRY OUT BY MID TO LATE
TOMORROW MORNING. IN CONTRAST...THE SE PENN AIRFIELDS SUCH AS
KMDT...KTHV AND KLNS WILL SEE MAINLY VFR.

NORTHWEST WINDS OF 10-15 KTS WITH HIGHER GUSTS WILL DECREASE TO 8
KTS OR LESS LATER TONIGHT AND SATURDAY.

HIGH PRESSURE BUILDS EAST ACROSS PENN SATURDAY...WITH BKN-OVC CIGS
VARYING BETWEEN MVFR OVER THE HIGHER TERRAIN OF THE NORTH AND
WEST...TO SCT-BKN VFR IN THE VALLEYS.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...FITZGERALD
SHORT TERM...LAMBERT
LONG TERM...EVANEGO
AVIATION...LAMBERT/CERU




000
FXUS61 KCTP 200636
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
136 AM EST SAT DEC 20 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE WESTERN GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND...BRINGING DRY WEATHER WITH
LIGHTER WIND. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK
LIKELY BRINGING US RAIN AND WIND FOR CHRISTMAS EVE...THEN BLUSTERY
AND COLDER CONDITIONS FOR CHRISTMAS DAY WITH SCATTERED SNOW
SHOWERS.

&&

.NEAR TERM /UNTIL 8 AM THIS MORNING/...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK TRAPPED BELOW A
MODERATELY STRONG SUBSIDENCE INVERSION /BASED AT AROUND 2-3KFT
AGL/ WILL PERSIST ACROSS MUCH OF CENTRAL PENNSYLVANIA EARLY THIS
MORNING. APPROACH OF SFC HIGH AND FALLING INVERSION HGT HAS
RESULTED IN PARTIAL CLEARING ACROSS THE SC MTNS AND NR TERM MDL
SOUNDINGS INDICATE THIS AREA WILL REMAIN MCLEAR THRU DAWN...WHILE
STRATOCU PERSISTS ELSEWHERE. TEMPS ON TRACK TO BOTTOM OUT IN THE
20S.

&&

.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SUNDAY/...
A RIDGE OF HIGH PRESSURE...LIGHTER WIND...AND ASSOC DRIER AIR
MASS WILL BUILD EAST ACROSS THE STATE SATURDAY...PROVIDING THE
AREA WITH FAIR WEATHER.

HIGH RES MODEL DATA CONTINUES TO PAINT A MOSTLY CLOUDY PICTURE FOR
MUCH OF THE REGION SATURDAY INTO SATURDAY NIGHT...THOUGH PERIODS
OF SUNSHINE ARE LIKELY THROUGHOUT THE CENTRAL RIDGE AND VALLEY
REGION...AND SUSQUEHANNA RIVER VALLEY.

WAA ALOFT IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE MISS VALLEY
WILL LIKELY SPREAD SOME THIN CIRRUS OVER THE LOWER/THIN STRATO CU
CLOUD DECK PRESENT ACROSS THE REGION SATURDAY. ALL 12Z OPERATIONAL
MODEL DATA CONTINUES TO SUPPORT A DRY DAY WITH SFC RIDGE AND LOW
PWAT AIRMASS OVR THE STATE. MAX TEMPS SHOULD BE FAIRLY CLOSE TO
SEASONAL NORMS NEAR 30 ACROSS THE MTNS...AND MID TO UPPER 30S IN
THE SE.

MOSTLY CLOUDY SKIES WITH LIGHT WIND SAT NIGHT WILL YIELD LOWS IN
THE LOWER 20S ACROSS THE MTNS...AND GENERALLY THE MID 20S
ELSEWHERE.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGH PRES WILL PROVIDE TRANQUIL WEATHER ON SUNDAY...WITH PARTLY TO
MOSTLY SUNNY SKIES AND SEASONABLE TEMPS. AFTER THAT...THE WEATHER
WILL BECOME INCREASINGLY UNSETTLED AS NEXT WEEK PROGRESSES.

CLOUDS WILL INCR SUNDAY NIGHT INTO MONDAY...AS HIGH PRES LOSES
ITS GRIP AND A WEAK AREA OF LOW PRES ORGANIZES OVER THE SERN UNITED
STATES. LIGHT PRECIP WILL WORK NWD INTO PENNSYLVANIA LATE MONDAY
INTO MONDAY NIGHT AND CONTINUE INTO TUES. INITIALLY...CONDS WILL
BE COLD ENOUGH FOR THE POSSIBILITY OF SOME WINTRY PRECIP.
HOWEVER...WARMER AIR WILL MAKE ITS WAY NWD LATER MONDAY NIGHT INTO
TUES AND GRADUALLY CHANGE ANY LINGERING PRECIP OVER TO PLAIN RAIN.

A MORE SIGNIFICANT STORM SYSTEM WILL GET ORGANIZED OVER THE
MISSISSIPPI VALLEY TUES NIGHT BEFORE PUSHING NWD INTO THE GREAT
LAKES ON WED. THIS SYSTEM WILL DRAW EVEN MILDER AIR NWD INTO THE
REGION...AND PROVIDE A RAINY AND BREEZY CHRISTMAS EVE DAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS FROM WEST TO EAST ACROSS PA IS POSSIBLE LATE WED/WED
NIGHT. SCT SNOW SHOWERS WILL CONTINUE INTO THURS ACROSS MAINLY
NRN AND WRN PA.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
OPERATIONAL MODELS AND THE GEFS SHOWING 850HPA TEMPS ALREADY
BEGINNING TO RISE NEXT FRI.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
NORTHWESTERLY SFC FLOW THAT HAS CAUSED OROGRAPHIC FORCING OF A
SHALLOW MOIST LAYER WILL CONTINUE TO PRODUCE PLENTY OF CLOUDS
ACROSS THE NW AND THE LAURELS WITH MAINLY MVFR BKN-OVC CIGS
THROUGH TONIGHT. KJST AND KBFD WILL TREND IFR THROUGH 12Z...AND
CIGS WILL SLOWLY INCREASE AS THE LOW LEVELS DRY OUT BY MID TO LATE
TOMORROW MORNING. IN CONTRAST...THE SE PENN AIRFIELDS SUCH AS
KMDT...KTHV AND KLNS WILL SEE MAINLY VFR.

NORTHWEST WINDS OF 10-15 KTS WITH HIGHER GUSTS WILL DECREASE TO 8
KTS OR LESS LATER TONIGHT AND SATURDAY.

HIGH PRESSURE BUILDS EAST ACROSS PENN SATURDAY...WITH BKN-OVC CIGS
VARYING BETWEEN MVFR OVER THE HIGHER TERRAIN OF THE NORTH AND
WEST...TO SCT-BKN VFR IN THE VALLEYS.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...FITZGERALD
SHORT TERM...LAMBERT
LONG TERM...EVANEGO
AVIATION...LAMBERT/CERU





000
FXUS61 KCTP 200455
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1155 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE WESTERN GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND...BRINGING DRY WEATHER WITH
LIGHTER WIND. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK
LIKELY BRINGING US RAIN AND WIND FOR CHRISTMAS EVE...THEN BLUSTERY
AND COLDER CONDITIONS FOR CHRISTMAS DAY WITH SCATTERED SNOW
SHOWERS.

&&

.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
930 PM UPDATE...
CLOUDS AND TEMPS BEHAVING. NO NEED FOR ANYTHING OTHER THAN TINY
TWEAKS.

7 PM UPDATE...
BIG BREAKS IN CLOUDS LOCALLY. NRLY FLOW IS SHOVING THE CLOUDS DOWN
INTO THE POCONOS AND TRYING TO GET THEM INTO LEB/LANC COS. AT THIS
POINT...WILL CONTINUE TO COUNT ON THE DOWNSLOPE TO KEEP IT FROM
GOING TOTALLY OVC...BUT SOME INCREASE IN CLOUDS OVER THE NEXT FEW
HRS IN THE SE IS PROBABLY A GOOD CALL. OTHERWISE...THE SUBSIDENCE
IN BETWEEN THE NERN AND SERN PARTS OF THE STATE MAY CONTINUE TO
OPEN UP BIGGER BREAKS. WILL HAVE TO TWEAK NWRN MIN TEMPS AS THEY
ARE EXTREMELY CLOSE TO GOING MINS ATTM. ELSEWHERE...DEWPOINTS AND
ONLY SLOW DECREASE IN COVG LOOK LIKE THE MINS ARE OKAY FOR NOW.

PREV...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK TRAPPED BELOW A
MODERATELY STRONG SUBSIDENCE INVERSION /BASED AT AROUND 2-3KFT
AGL/ WILL PERSIST ACROSS MUCH OF NORTHERN AND WESTERN PENNSYLVANIA
LATE TODAY INTO SATURDAY...WHILE PARTIAL CLEARING OCCURS ACROSS
THE LOWER SUSQ VALLEY AND SURROUNDING AREAS.

TEMPS WILL REMAIN STEADY THROUGH LATE THIS AFTERNOON UNDER THE
10-15 KT NWRLY FLOW. READINGS WILL VARY FROM THE MID TO UPPER 20S
ACROSS THE NORTHERN AND WESTERN MOUNTAINS...TO THE LOWER 40S IN
THE SOUTHEAST.

A WEAK SFC RIDGE WILL MOVE TO NEAR THE PENN/OHIO BORDER BY 12Z
SATURDAY...BUT THE WEAK WESTERLY ISENTROPIC LIFT ALONG THE 285K
THETA SFC...AND SOME SHALLOW MOISTURE BEING ADVECTED SWD INTO THE
NRN MTNS OF PENN FROM LAKE ONTARIO...WILL MAINTAIN MOSTLY CLOUDY
TO CLOUDY SKIES. LITTLE MORE THAN A FEW FLURRIES OR SPOTTY -FZDZ
WILL FALL FROM THIS THIN CLOUD LAYER ACROSS THE HIGHER TERRAIN OF
THE LAURELS AND INVOF KBFD.

AFTER A PTLY CLOUDY LATE AFTERNOON AND EVENING IN THE SE PART OF
THE CWA...A BKN LAYER OF STRATO CU IS EXPECTED TO DRIFT SE /OR
FORM/ ACROSS THE REGION OVERNIGHT.

DUE TO THE NW-SE GRADIENT OF DECREASING CLOUDS...LOW TEMPS AT
DAYBREAK SAT WILL BE IN A RATHER TIGHT RANGE...FROM THE UPPER
TEENS TO LOWER 20S ACROSS THE MOUNTAINS...TO THE LOWER 20S IN THE
SE

&&

.SHORT TERM /8 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
A RIDGE OF HIGH PRESSURE...LIGHTER WIND...AND ASSOC DRIER AIR
MASS WILL BUILD EAST ACROSS THE STATE SATURDAY...PROVIDING THE
AREA WITH FAIR WEATHER.

HIGH RES MODEL DATA CONTINUES TO PAINT A MOSTLY CLOUDY PICTURE FOR
MUCH OF THE REGION SATURDAY INTO SATURDAY NIGHT...THOUGH PERIODS
OF SUNSHINE ARE LIKELY THROUGHOUT THE CENTRAL RIDGE AND VALLEY
REGION...AND SUSQUEHANNA RIVER VALLEY.

WAA ALOFT IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE MISS VALLEY
WILL LIKELY SPREAD SOME THIN CIRRUS OVER THE LOWER/THIN STRATO CU
CLOUD DECK PRESENT ACROSS THE REGION SATURDAY. ALL 12Z OPERATIONAL
MODEL DATA CONTINUES TO SUPPORT A DRY DAY WITH SFC RIDGE AND LOW
PWAT AIRMASS OVR THE STATE. MAX TEMPS SHOULD BE FAIRLY CLOSE TO
SEASONAL NORMS NEAR 30 ACROSS THE MTNS...AND MID TO UPPER 30S IN
THE SE.

MOSTLY CLOUDY SKIES WITH LIGHT WIND SAT NIGHT WILL YIELD LOWS IN
THE LOWER 20S ACROSS THE MTNS...AND GENERALLY THE MID 20S
ELSEWHERE.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGH PRES WILL PROVIDE TRANQUIL WEATHER ON SUNDAY...WITH PARTLY TO
MOSTLY SUNNY SKIES AND SEASONABLE TEMPS. AFTER THAT...THE WEATHER
WILL BECOME INCREASINGLY UNSETTLED AS NEXT WEEK PROGRESSES.

CLOUDS WILL INCR SUNDAY NIGHT INTO MONDAY...AS HIGH PRES LOSES
ITS GRIP AND A WEAK AREA OF LOW PRES ORGANIZES OVER THE SERN UNITED
STATES. LIGHT PRECIP WILL WORK NWD INTO PENNSYLVANIA LATE MONDAY
INTO MONDAY NIGHT AND CONTINUE INTO TUES. INITIALLY...CONDS WILL
BE COLD ENOUGH FOR THE POSSIBILITY OF SOME WINTRY PRECIP.
HOWEVER...WARMER AIR WILL MAKE ITS WAY NWD LATER MONDAY NIGHT INTO
TUES AND GRADUALLY CHANGE ANY LINGERING PRECIP OVER TO PLAIN RAIN.

A MORE SIGNIFICANT STORM SYSTEM WILL GET ORGANIZED OVER THE
MISSISSIPPI VALLEY TUES NIGHT BEFORE PUSHING NWD INTO THE GREAT
LAKES ON WED. THIS SYSTEM WILL DRAW EVEN MILDER AIR NWD INTO THE
REGION...AND PROVIDE A RAINY AND BREEZY CHRISTMAS EVE DAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS FROM WEST TO EAST ACROSS PA IS POSSIBLE LATE WED/WED
NIGHT. SCT SNOW SHOWERS WILL CONTINUE INTO THURS ACROSS MAINLY
NRN AND WRN PA.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
OPERATIONAL MODELS AND THE GEFS SHOWING 850HPA TEMPS ALREADY
BEGINNING TO RISE NEXT FRI.

&&

.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
NORTHWESTERLY SFC FLOW THAT HAS CAUSED OROGRAPHIC FORCING OF A
SHALLOW MOIST LAYER WILL CONTINUE TO PRODUCE PLENTY OF CLOUDS
ACROSS THE NW AND THE LAURELS WITH MAINLY MVFR BKN-OVC CIGS
THROUGH TONIGHT. KJST AND KBFD WILL TREND IFR THROUGH 12Z...AND
CIGS WILL SLOWLY INCREASE AS THE LOW LEVELS DRY OUT BY MID TO LATE
TOMORROW MORNING. IN CONTRAST...THE SE PENN AIRFIELDS SUCH AS
KMDT...KTHV AND KLNS WILL SEE MAINLY VFR.

NORTHWEST WINDS OF 10-15 KTS WITH HIGHER GUSTS WILL DECREASE TO 8
KTS OR LESS LATER TONIGHT AND SATURDAY.

HIGH PRESSURE BUILDS EAST ACROSS PENN SATURDAY...WITH BKN-OVC CIGS
VARYING BETWEEN MVFR OVER THE HIGHER TERRAIN OF THE NORTH AND
WEST...TO SCT-BKN VFR IN THE VALLEYS.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...EVANEGO
AVIATION...LAMBERT/CERU




000
FXUS61 KCTP 200237
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
937 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE WESTERN GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND...BRINGING DRY WEATHER WITH
LIGHTER WIND. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK
LIKELY BRINGING US RAIN AND WIND FOR CHRISTMAS EVE...THEN BLUSTERY
AND COLDER CONDITIONS FOR CHRISTMAS DAY WITH SCATTERED SNOW
SHOWERS.

&&

.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
930 PM UPDATE...
CLOUDS AND TEMPS BEHAVING. NO NEED FOR ANYTHING OTHER THAN TINY
TWEAKS.

7 PM UPDATE...
BIG BREAKS IN CLOUDS LOCALLY. NRLY FLOW IS SHOVING THE CLOUDS DOWN
INTO THE POCONOS AND TRYING TO GET THEM INTO LEB/LANC COS. AT THIS
POINT...WILL CONTINUE TO COUNT ON THE DOWNSLOPE TO KEEP IT FROM
GOING TOTALLY OVC...BUT SOME INCREASE IN CLOUDS OVER THE NEXT FEW
HRS IN THE SE IS PROBABLY A GOOD CALL. OTHERWISE...THE SUBSIDENCE
IN BETWEEN THE NERN AND SERN PARTS OF THE STATE MAY CONTINUE TO
OPEN UP BIGGER BREAKS. WILL HAVE TO TWEAK NWRN MIN TEMPS AS THEY
ARE EXTREMELY CLOSE TO GOING MINS ATTM. ELSEWHERE...DEWPOINTS AND
ONLY SLOW DECREASE IN COVG LOOK LIKE THE MINS ARE OKAY FOR NOW.

PREV...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK TRAPPED BELOW A
MODERATELY STRONG SUBSIDENCE INVERSION /BASED AT AROUND 2-3KFT
AGL/ WILL PERSIST ACROSS MUCH OF NORTHERN AND WESTERN PENNSYLVANIA
LATE TODAY INTO SATURDAY...WHILE PARTIAL CLEARING OCCURS ACROSS
THE LOWER SUSQ VALLEY AND SURROUNDING AREAS.

TEMPS WILL REMAIN STEADY THROUGH LATE THIS AFTERNOON UNDER THE
10-15 KT NWRLY FLOW. READINGS WILL VARY FROM THE MID TO UPPER 20S
ACROSS THE NORTHERN AND WESTERN MOUNTAINS...TO THE LOWER 40S IN
THE SOUTHEAST.

A WEAK SFC RIDGE WILL MOVE TO NEAR THE PENN/OHIO BORDER BY 12Z
SATURDAY...BUT THE WEAK WESTERLY ISENTROPIC LIFT ALONG THE 285K
THETA SFC...AND SOME SHALLOW MOISTURE BEING ADVECTED SWD INTO THE
NRN MTNS OF PENN FROM LAKE ONTARIO...WILL MAINTAIN MOSTLY CLOUDY
TO CLOUDY SKIES. LITTLE MORE THAN A FEW FLURRIES OR SPOTTY -FZDZ
WILL FALL FROM THIS THIN CLOUD LAYER ACROSS THE HIGHER TERRAIN OF
THE LAURELS AND INVOF KBFD.

AFTER A PTLY CLOUDY LATE AFTERNOON AND EVENING IN THE SE PART OF
THE CWA...A BKN LAYER OF STRATO CU IS EXPECTED TO DRIFT SE /OR
FORM/ ACROSS THE REGION OVERNIGHT.

DUE TO THE NW-SE GRADIENT OF DECREASING CLOUDS...LOW TEMPS AT
DAYBREAK SAT WILL BE IN A RATHER TIGHT RANGE...FROM THE UPPER
TEENS TO LOWER 20S ACROSS THE MOUNTAINS...TO THE LOWER 20S IN THE
SE

&&

.SHORT TERM /8 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
A RIDGE OF HIGH PRESSURE...LIGHTER WIND...AND ASSOC DRIER AIR
MASS WILL BUILD EAST ACROSS THE STATE SATURDAY...PROVIDING THE
AREA WITH FAIR WEATHER.

HIGH RES MODEL DATA CONTINUES TO PAINT A MOSTLY CLOUDY PICTURE FOR
MUCH OF THE REGION SATURDAY INTO SATURDAY NIGHT...THOUGH PERIODS
OF SUNSHINE ARE LIKELY THROUGHOUT THE CENTRAL RIDGE AND VALLEY
REGION...AND SUSQUEHANNA RIVER VALLEY.

WAA ALOFT IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE MISS VALLEY
WILL LIKELY SPREAD SOME THIN CIRRUS OVER THE LOWER/THIN STRATO CU
CLOUD DECK PRESENT ACROSS THE REGION SATURDAY. ALL 12Z OPERATIONAL
MODEL DATA CONTINUES TO SUPPORT A DRY DAY WITH SFC RIDGE AND LOW
PWAT AIRMASS OVR THE STATE. MAX TEMPS SHOULD BE FAIRLY CLOSE TO
SEASONAL NORMS NEAR 30 ACROSS THE MTNS...AND MID TO UPPER 30S IN
THE SE.

MOSTLY CLOUDY SKIES WITH LIGHT WIND SAT NIGHT WILL YIELD LOWS IN
THE LOWER 20S ACROSS THE MTNS...AND GENERALLY THE MID 20S
ELSEWHERE.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGH PRES WILL PROVIDE TRANQUIL WEATHER ON SUNDAY...WITH PARTLY TO
MOSTLY SUNNY SKIES AND SEASONABLE TEMPS. AFTER THAT...THE WEATHER
WILL BECOME INCREASINGLY UNSETTLED AS NEXT WEEK PROGRESSES.

CLOUDS WILL INCR SUNDAY NIGHT INTO MONDAY...AS HIGH PRES LOSES
ITS GRIP AND A WEAK AREA OF LOW PRES ORGANIZES OVER THE SERN UNITED
STATES. LIGHT PRECIP WILL WORK NWD INTO PENNSYLVANIA LATE MONDAY
INTO MONDAY NIGHT AND CONTINUE INTO TUES. INITIALLY...CONDS WILL
BE COLD ENOUGH FOR THE POSSIBILITY OF SOME WINTRY PRECIP.
HOWEVER...WARMER AIR WILL MAKE ITS WAY NWD LATER MONDAY NIGHT INTO
TUES AND GRADUALLY CHANGE ANY LINGERING PRECIP OVER TO PLAIN RAIN.

A MORE SIGNIFICANT STORM SYSTEM WILL GET ORGANIZED OVER THE
MISSISSIPPI VALLEY TUES NIGHT BEFORE PUSHING NWD INTO THE GREAT
LAKES ON WED. THIS SYSTEM WILL DRAW EVEN MILDER AIR NWD INTO THE
REGION...AND PROVIDE A RAINY AND BREEZY CHRISTMAS EVE DAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS FROM WEST TO EAST ACROSS PA IS POSSIBLE LATE WED/WED
NIGHT. SCT SNOW SHOWERS WILL CONTINUE INTO THURS ACROSS MAINLY
NRN AND WRN PA.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
OPERATIONAL MODELS AND THE GEFS SHOWING 850HPA TEMPS ALREADY
BEGINNING TO RISE NEXT FRI.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
LLVL NWRLY FLOW AND OROGRAPHIC FORCING OF A SHALLOW MOIST LAYER
WILL CONTINUE TO PRODUCE PLENTY OF CLOUDS ACROSS THE NW 1/2 TO
2/3RDS OF THE STATE WITH MAINLY MVFR BKN-OVC CIGS THROUGH
TONIGHT. KJST AND KBFD MAY TEETER ON THE UPPER END OF IFR FOR A
FEW HOURS LATER TONIGHT /AFTER 06Z/. IN CONTRAST...THE SE PENN
AIRFIELDS SUCH AS KMDT...KTHV AND KLNS WILL SEE MAINLY VFR...WITH
SKY CONDITIONS VARYING SCT-BKN030-040.

NORTHWEST WINDS OF 10-15 KTS WITH HIGHER GUSTS WILL DECREASE TO 8
KTS OR LESS LATER TONIGHT AND SATURDAY.

HIGH PRESSURE BUILDS EAST ACROSS PENN SATURDAY...WITH BKN-OVC CIGS
VARYING BETWEEN MVFR OVER THE HIGHER TERRAIN OF THE NORTH AND
WEST...TO SCT-BKN VFR IN THE VALLEYS.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...EVANEGO
AVIATION...LAMBERT/CERU





000
FXUS61 KCTP 200237
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
937 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE WESTERN GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND...BRINGING DRY WEATHER WITH
LIGHTER WIND. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK
LIKELY BRINGING US RAIN AND WIND FOR CHRISTMAS EVE...THEN BLUSTERY
AND COLDER CONDITIONS FOR CHRISTMAS DAY WITH SCATTERED SNOW
SHOWERS.

&&

.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
930 PM UPDATE...
CLOUDS AND TEMPS BEHAVING. NO NEED FOR ANYTHING OTHER THAN TINY
TWEAKS.

7 PM UPDATE...
BIG BREAKS IN CLOUDS LOCALLY. NRLY FLOW IS SHOVING THE CLOUDS DOWN
INTO THE POCONOS AND TRYING TO GET THEM INTO LEB/LANC COS. AT THIS
POINT...WILL CONTINUE TO COUNT ON THE DOWNSLOPE TO KEEP IT FROM
GOING TOTALLY OVC...BUT SOME INCREASE IN CLOUDS OVER THE NEXT FEW
HRS IN THE SE IS PROBABLY A GOOD CALL. OTHERWISE...THE SUBSIDENCE
IN BETWEEN THE NERN AND SERN PARTS OF THE STATE MAY CONTINUE TO
OPEN UP BIGGER BREAKS. WILL HAVE TO TWEAK NWRN MIN TEMPS AS THEY
ARE EXTREMELY CLOSE TO GOING MINS ATTM. ELSEWHERE...DEWPOINTS AND
ONLY SLOW DECREASE IN COVG LOOK LIKE THE MINS ARE OKAY FOR NOW.

PREV...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK TRAPPED BELOW A
MODERATELY STRONG SUBSIDENCE INVERSION /BASED AT AROUND 2-3KFT
AGL/ WILL PERSIST ACROSS MUCH OF NORTHERN AND WESTERN PENNSYLVANIA
LATE TODAY INTO SATURDAY...WHILE PARTIAL CLEARING OCCURS ACROSS
THE LOWER SUSQ VALLEY AND SURROUNDING AREAS.

TEMPS WILL REMAIN STEADY THROUGH LATE THIS AFTERNOON UNDER THE
10-15 KT NWRLY FLOW. READINGS WILL VARY FROM THE MID TO UPPER 20S
ACROSS THE NORTHERN AND WESTERN MOUNTAINS...TO THE LOWER 40S IN
THE SOUTHEAST.

A WEAK SFC RIDGE WILL MOVE TO NEAR THE PENN/OHIO BORDER BY 12Z
SATURDAY...BUT THE WEAK WESTERLY ISENTROPIC LIFT ALONG THE 285K
THETA SFC...AND SOME SHALLOW MOISTURE BEING ADVECTED SWD INTO THE
NRN MTNS OF PENN FROM LAKE ONTARIO...WILL MAINTAIN MOSTLY CLOUDY
TO CLOUDY SKIES. LITTLE MORE THAN A FEW FLURRIES OR SPOTTY -FZDZ
WILL FALL FROM THIS THIN CLOUD LAYER ACROSS THE HIGHER TERRAIN OF
THE LAURELS AND INVOF KBFD.

AFTER A PTLY CLOUDY LATE AFTERNOON AND EVENING IN THE SE PART OF
THE CWA...A BKN LAYER OF STRATO CU IS EXPECTED TO DRIFT SE /OR
FORM/ ACROSS THE REGION OVERNIGHT.

DUE TO THE NW-SE GRADIENT OF DECREASING CLOUDS...LOW TEMPS AT
DAYBREAK SAT WILL BE IN A RATHER TIGHT RANGE...FROM THE UPPER
TEENS TO LOWER 20S ACROSS THE MOUNTAINS...TO THE LOWER 20S IN THE
SE

&&

.SHORT TERM /8 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
A RIDGE OF HIGH PRESSURE...LIGHTER WIND...AND ASSOC DRIER AIR
MASS WILL BUILD EAST ACROSS THE STATE SATURDAY...PROVIDING THE
AREA WITH FAIR WEATHER.

HIGH RES MODEL DATA CONTINUES TO PAINT A MOSTLY CLOUDY PICTURE FOR
MUCH OF THE REGION SATURDAY INTO SATURDAY NIGHT...THOUGH PERIODS
OF SUNSHINE ARE LIKELY THROUGHOUT THE CENTRAL RIDGE AND VALLEY
REGION...AND SUSQUEHANNA RIVER VALLEY.

WAA ALOFT IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE MISS VALLEY
WILL LIKELY SPREAD SOME THIN CIRRUS OVER THE LOWER/THIN STRATO CU
CLOUD DECK PRESENT ACROSS THE REGION SATURDAY. ALL 12Z OPERATIONAL
MODEL DATA CONTINUES TO SUPPORT A DRY DAY WITH SFC RIDGE AND LOW
PWAT AIRMASS OVR THE STATE. MAX TEMPS SHOULD BE FAIRLY CLOSE TO
SEASONAL NORMS NEAR 30 ACROSS THE MTNS...AND MID TO UPPER 30S IN
THE SE.

MOSTLY CLOUDY SKIES WITH LIGHT WIND SAT NIGHT WILL YIELD LOWS IN
THE LOWER 20S ACROSS THE MTNS...AND GENERALLY THE MID 20S
ELSEWHERE.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGH PRES WILL PROVIDE TRANQUIL WEATHER ON SUNDAY...WITH PARTLY TO
MOSTLY SUNNY SKIES AND SEASONABLE TEMPS. AFTER THAT...THE WEATHER
WILL BECOME INCREASINGLY UNSETTLED AS NEXT WEEK PROGRESSES.

CLOUDS WILL INCR SUNDAY NIGHT INTO MONDAY...AS HIGH PRES LOSES
ITS GRIP AND A WEAK AREA OF LOW PRES ORGANIZES OVER THE SERN UNITED
STATES. LIGHT PRECIP WILL WORK NWD INTO PENNSYLVANIA LATE MONDAY
INTO MONDAY NIGHT AND CONTINUE INTO TUES. INITIALLY...CONDS WILL
BE COLD ENOUGH FOR THE POSSIBILITY OF SOME WINTRY PRECIP.
HOWEVER...WARMER AIR WILL MAKE ITS WAY NWD LATER MONDAY NIGHT INTO
TUES AND GRADUALLY CHANGE ANY LINGERING PRECIP OVER TO PLAIN RAIN.

A MORE SIGNIFICANT STORM SYSTEM WILL GET ORGANIZED OVER THE
MISSISSIPPI VALLEY TUES NIGHT BEFORE PUSHING NWD INTO THE GREAT
LAKES ON WED. THIS SYSTEM WILL DRAW EVEN MILDER AIR NWD INTO THE
REGION...AND PROVIDE A RAINY AND BREEZY CHRISTMAS EVE DAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS FROM WEST TO EAST ACROSS PA IS POSSIBLE LATE WED/WED
NIGHT. SCT SNOW SHOWERS WILL CONTINUE INTO THURS ACROSS MAINLY
NRN AND WRN PA.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
OPERATIONAL MODELS AND THE GEFS SHOWING 850HPA TEMPS ALREADY
BEGINNING TO RISE NEXT FRI.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
LLVL NWRLY FLOW AND OROGRAPHIC FORCING OF A SHALLOW MOIST LAYER
WILL CONTINUE TO PRODUCE PLENTY OF CLOUDS ACROSS THE NW 1/2 TO
2/3RDS OF THE STATE WITH MAINLY MVFR BKN-OVC CIGS THROUGH
TONIGHT. KJST AND KBFD MAY TEETER ON THE UPPER END OF IFR FOR A
FEW HOURS LATER TONIGHT /AFTER 06Z/. IN CONTRAST...THE SE PENN
AIRFIELDS SUCH AS KMDT...KTHV AND KLNS WILL SEE MAINLY VFR...WITH
SKY CONDITIONS VARYING SCT-BKN030-040.

NORTHWEST WINDS OF 10-15 KTS WITH HIGHER GUSTS WILL DECREASE TO 8
KTS OR LESS LATER TONIGHT AND SATURDAY.

HIGH PRESSURE BUILDS EAST ACROSS PENN SATURDAY...WITH BKN-OVC CIGS
VARYING BETWEEN MVFR OVER THE HIGHER TERRAIN OF THE NORTH AND
WEST...TO SCT-BKN VFR IN THE VALLEYS.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...EVANEGO
AVIATION...LAMBERT/CERU




000
FXUS61 KCTP 200000
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
700 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE WESTERN GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND...BRINGING DRY WEATHER WITH
LIGHTER WIND. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK
LIKELY BRINGING US RAIN AND WIND FOR CHRISTMAS EVE...THEN BLUSTERY
AND COLDER CONDITIONS FOR CHRISTMAS DAY WITH SCATTERED SNOW
SHOWERS.

&&

.NEAR TERM /UNTIL 7 AM SATURDAY MORNING/...
7 PM UPDATE...
BIG BREAKS IN CLOUDS LOCALLY. NRLY FLOW IS SHOVING THE CLOUDS DOWN
INTO THE POCONOS AND TRYING TO GET THEM INTO LEB/LANC COS. AT THIS
POINT...WILL CONTINUE TO COUNT ON THE DOWNSLOPE TO KEEP IT FROM
GOING TOTALLY OVC...BUT SOME INCREASE IN CLOUDS OVER THE NEXT FEW
HRS IN THE SE IS PROBABLY A GOOD CALL. OTHERWISE...THE SUBSIDENCE
IN BETWEEN THE NERN AND SERN PARTS OF THE STATE MAY CONTINUE TO
OPEN UP BIGGER BREAKS. WILL HAVE TO TWEAK NWRN MIN TEMPS AS THEY
ARE EXTREMELY CLOSE TO GOING MINS ATTM. ELSEWHERE...DEWPOINTS AND
ONLY SLOW DECREASE IN COVG LOOK LIKE THE MINS ARE OKAY FOR NOW.

PREV...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK TRAPPED BELOW A
MODERATELY STRONG SUBSIDENCE INVERSION /BASED AT AROUND 2-3KFT
AGL/ WILL PERSIST ACROSS MUCH OF NORTHERN AND WESTERN PENNSYLVANIA
LATE TODAY INTO SATURDAY...WHILE PARTIAL CLEARING OCCURS ACROSS
THE LOWER SUSQ VALLEY AND SURROUNDING AREAS.

TEMPS WILL REMAIN STEADY THROUGH LATE THIS AFTERNOON UNDER THE
10-15 KT NWRLY FLOW. READINGS WILL VARY FROM THE MID TO UPPER 20S
ACROSS THE NORTHERN AND WESTERN MOUNTAINS...TO THE LOWER 40S IN
THE SOUTHEAST.

A WEAK SFC RIDGE WILL MOVE TO NEAR THE PENN/OHIO BORDER BY 12Z
SATURDAY...BUT THE WEAK WESTERLY ISENTROPIC LIFT ALONG THE 285K
THETA SFC...AND SOME SHALLOW MOISTURE BEING ADVECTED SWD INTO THE
NRN MTNS OF PENN FROM LAKE ONTARIO...WILL MAINTAIN MOSTLY CLOUDY
TO CLOUDY SKIES. LITTLE MORE THAN A FEW FLURRIES OR SPOTTY -FZDZ
WILL FALL FROM THIS THIN CLOUD LAYER ACROSS THE HIGHER TERRAIN OF
THE LAURELS AND INVOF KBFD.

AFTER A PTLY CLOUDY LATE AFTERNOON AND EVENING IN THE SE PART OF
THE CWA...A BKN LAYER OF STRATO CU IS EXPECTED TO DRIFT SE /OR
FORM/ ACROSS THE REGION OVERNIGHT.

DUE TO THE NW-SE GRADIENT OF DECREASING CLOUDS...LOW TEMPS AT
DAYBREAK SAT WILL BE IN A RATHER TIGHT RANGE...FROM THE UPPER
TEENS TO LOWER 20S ACROSS THE MOUNTAINS...TO THE LOWER 20S IN THE
SE

&&

.SHORT TERM /7 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
A RIDGE OF HIGH PRESSURE...LIGHTER WIND...AND ASSOC DRIER AIR
MASS WILL BUILD EAST ACROSS THE STATE SATURDAY...PROVIDING THE
AREA WITH FAIR WEATHER.

HIGH RES MODEL DATA CONTINUES TO PAINT A MOSTLY CLOUDY PICTURE FOR
MUCH OF THE REGION SATURDAY INTO SATURDAY NIGHT...THOUGH PERIODS
OF SUNSHINE ARE LIKELY THROUGHOUT THE CENTRAL RIDGE AND VALLEY
REGION...AND SUSQUEHANNA RIVER VALLEY.

WAA ALOFT IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE MISS VALLEY
WILL LIKELY SPREAD SOME THIN CIRRUS OVER THE LOWER/THIN STRATO CU
CLOUD DECK PRESENT ACROSS THE REGION SATURDAY. ALL 12Z OPERATIONAL
MODEL DATA CONTINUES TO SUPPORT A DRY DAY WITH SFC RIDGE AND LOW
PWAT AIRMASS OVR THE STATE. MAX TEMPS SHOULD BE FAIRLY CLOSE TO
SEASONAL NORMS NEAR 30 ACROSS THE MTNS...AND MID TO UPPER 30S IN
THE SE.

MOSTLY CLOUDY SKIES WITH LIGHT WIND SAT NIGHT WILL YIELD LOWS IN
THE LOWER 20S ACROSS THE MTNS...AND GENERALLY THE MID 20S
ELSEWHERE.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGH PRES WILL PROVIDE TRANQUIL WEATHER ON SUNDAY...WITH PARTLY TO
MOSTLY SUNNY SKIES AND SEASONABLE TEMPS. AFTER THAT...THE WEATHER
WILL BECOME INCREASINGLY UNSETTLED AS NEXT WEEK PROGRESSES.

CLOUDS WILL INCR SUNDAY NIGHT INTO MONDAY...AS HIGH PRES LOSES
ITS GRIP AND A WEAK AREA OF LOW PRES ORGANIZES OVER THE SERN UNITED
STATES. LIGHT PRECIP WILL WORK NWD INTO PENNSYLVANIA LATE MONDAY
INTO MONDAY NIGHT AND CONTINUE INTO TUES. INITIALLY...CONDS WILL
BE COLD ENOUGH FOR THE POSSIBILITY OF SOME WINTRY PRECIP.
HOWEVER...WARMER AIR WILL MAKE ITS WAY NWD LATER MONDAY NIGHT INTO
TUES AND GRADUALLY CHANGE ANY LINGERING PRECIP OVER TO PLAIN RAIN.

A MORE SIGNIFICANT STORM SYSTEM WILL GET ORGANIZED OVER THE
MISSISSIPPI VALLEY TUES NIGHT BEFORE PUSHING NWD INTO THE GREAT
LAKES ON WED. THIS SYSTEM WILL DRAW EVEN MILDER AIR NWD INTO THE
REGION...AND PROVIDE A RAINY AND BREEZY CHRISTMAS EVE DAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS FROM WEST TO EAST ACROSS PA IS POSSIBLE LATE WED/WED
NIGHT. SCT SNOW SHOWERS WILL CONTINUE INTO THURS ACROSS MAINLY
NRN AND WRN PA.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
OPERATIONAL MODELS AND THE GEFS SHOWING 850HPA TEMPS ALREADY
BEGINNING TO RISE NEXT FRI.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
LLVL NWRLY FLOW AND OROGRAPHIC FORCING OF A SHALLOW MOIST LAYER
WILL CONTINUE TO PRODUCE PLENTY OF CLOUDS ACROSS THE NW 1/2 TO
2/3RDS OF THE STATE WITH MAINLY MVFR BKN-OVC CIGS THROUGH
TONIGHT. KJST AND KBFD MAY TEETER ON THE UPPER END OF IFR FOR A
FEW HOURS LATER TONIGHT /AFTER 06Z/. IN CONTRAST...THE SE PENN
AIRFIELDS SUCH AS KMDT...KTHV AND KLNS WILL SEE MAINLY VFR...WITH
SKY CONDITIONS VARYING SCT-BKN030-040.

NORTHWEST WINDS OF 10-15 KTS WITH HIGHER GUSTS WILL DECREASE TO 8
KTS OR LESS LATER TONIGHT AND SATURDAY.

HIGH PRESSURE BUILDS EAST ACROSS PENN SATURDAY...WITH BKN-OVC CIGS
VARYING BETWEEN MVFR OVER THE HIGHER TERRAIN OF THE NORTH AND
WEST...TO SCT-BKN VFR IN THE VALLEYS.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...EVANEGO
AVIATION...LAMBERT/CERU




000
FXUS61 KCTP 200000
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
700 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE WESTERN GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND...BRINGING DRY WEATHER WITH
LIGHTER WIND. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK
LIKELY BRINGING US RAIN AND WIND FOR CHRISTMAS EVE...THEN BLUSTERY
AND COLDER CONDITIONS FOR CHRISTMAS DAY WITH SCATTERED SNOW
SHOWERS.

&&

.NEAR TERM /UNTIL 7 AM SATURDAY MORNING/...
7 PM UPDATE...
BIG BREAKS IN CLOUDS LOCALLY. NRLY FLOW IS SHOVING THE CLOUDS DOWN
INTO THE POCONOS AND TRYING TO GET THEM INTO LEB/LANC COS. AT THIS
POINT...WILL CONTINUE TO COUNT ON THE DOWNSLOPE TO KEEP IT FROM
GOING TOTALLY OVC...BUT SOME INCREASE IN CLOUDS OVER THE NEXT FEW
HRS IN THE SE IS PROBABLY A GOOD CALL. OTHERWISE...THE SUBSIDENCE
IN BETWEEN THE NERN AND SERN PARTS OF THE STATE MAY CONTINUE TO
OPEN UP BIGGER BREAKS. WILL HAVE TO TWEAK NWRN MIN TEMPS AS THEY
ARE EXTREMELY CLOSE TO GOING MINS ATTM. ELSEWHERE...DEWPOINTS AND
ONLY SLOW DECREASE IN COVG LOOK LIKE THE MINS ARE OKAY FOR NOW.

PREV...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK TRAPPED BELOW A
MODERATELY STRONG SUBSIDENCE INVERSION /BASED AT AROUND 2-3KFT
AGL/ WILL PERSIST ACROSS MUCH OF NORTHERN AND WESTERN PENNSYLVANIA
LATE TODAY INTO SATURDAY...WHILE PARTIAL CLEARING OCCURS ACROSS
THE LOWER SUSQ VALLEY AND SURROUNDING AREAS.

TEMPS WILL REMAIN STEADY THROUGH LATE THIS AFTERNOON UNDER THE
10-15 KT NWRLY FLOW. READINGS WILL VARY FROM THE MID TO UPPER 20S
ACROSS THE NORTHERN AND WESTERN MOUNTAINS...TO THE LOWER 40S IN
THE SOUTHEAST.

A WEAK SFC RIDGE WILL MOVE TO NEAR THE PENN/OHIO BORDER BY 12Z
SATURDAY...BUT THE WEAK WESTERLY ISENTROPIC LIFT ALONG THE 285K
THETA SFC...AND SOME SHALLOW MOISTURE BEING ADVECTED SWD INTO THE
NRN MTNS OF PENN FROM LAKE ONTARIO...WILL MAINTAIN MOSTLY CLOUDY
TO CLOUDY SKIES. LITTLE MORE THAN A FEW FLURRIES OR SPOTTY -FZDZ
WILL FALL FROM THIS THIN CLOUD LAYER ACROSS THE HIGHER TERRAIN OF
THE LAURELS AND INVOF KBFD.

AFTER A PTLY CLOUDY LATE AFTERNOON AND EVENING IN THE SE PART OF
THE CWA...A BKN LAYER OF STRATO CU IS EXPECTED TO DRIFT SE /OR
FORM/ ACROSS THE REGION OVERNIGHT.

DUE TO THE NW-SE GRADIENT OF DECREASING CLOUDS...LOW TEMPS AT
DAYBREAK SAT WILL BE IN A RATHER TIGHT RANGE...FROM THE UPPER
TEENS TO LOWER 20S ACROSS THE MOUNTAINS...TO THE LOWER 20S IN THE
SE

&&

.SHORT TERM /7 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
A RIDGE OF HIGH PRESSURE...LIGHTER WIND...AND ASSOC DRIER AIR
MASS WILL BUILD EAST ACROSS THE STATE SATURDAY...PROVIDING THE
AREA WITH FAIR WEATHER.

HIGH RES MODEL DATA CONTINUES TO PAINT A MOSTLY CLOUDY PICTURE FOR
MUCH OF THE REGION SATURDAY INTO SATURDAY NIGHT...THOUGH PERIODS
OF SUNSHINE ARE LIKELY THROUGHOUT THE CENTRAL RIDGE AND VALLEY
REGION...AND SUSQUEHANNA RIVER VALLEY.

WAA ALOFT IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE MISS VALLEY
WILL LIKELY SPREAD SOME THIN CIRRUS OVER THE LOWER/THIN STRATO CU
CLOUD DECK PRESENT ACROSS THE REGION SATURDAY. ALL 12Z OPERATIONAL
MODEL DATA CONTINUES TO SUPPORT A DRY DAY WITH SFC RIDGE AND LOW
PWAT AIRMASS OVR THE STATE. MAX TEMPS SHOULD BE FAIRLY CLOSE TO
SEASONAL NORMS NEAR 30 ACROSS THE MTNS...AND MID TO UPPER 30S IN
THE SE.

MOSTLY CLOUDY SKIES WITH LIGHT WIND SAT NIGHT WILL YIELD LOWS IN
THE LOWER 20S ACROSS THE MTNS...AND GENERALLY THE MID 20S
ELSEWHERE.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGH PRES WILL PROVIDE TRANQUIL WEATHER ON SUNDAY...WITH PARTLY TO
MOSTLY SUNNY SKIES AND SEASONABLE TEMPS. AFTER THAT...THE WEATHER
WILL BECOME INCREASINGLY UNSETTLED AS NEXT WEEK PROGRESSES.

CLOUDS WILL INCR SUNDAY NIGHT INTO MONDAY...AS HIGH PRES LOSES
ITS GRIP AND A WEAK AREA OF LOW PRES ORGANIZES OVER THE SERN UNITED
STATES. LIGHT PRECIP WILL WORK NWD INTO PENNSYLVANIA LATE MONDAY
INTO MONDAY NIGHT AND CONTINUE INTO TUES. INITIALLY...CONDS WILL
BE COLD ENOUGH FOR THE POSSIBILITY OF SOME WINTRY PRECIP.
HOWEVER...WARMER AIR WILL MAKE ITS WAY NWD LATER MONDAY NIGHT INTO
TUES AND GRADUALLY CHANGE ANY LINGERING PRECIP OVER TO PLAIN RAIN.

A MORE SIGNIFICANT STORM SYSTEM WILL GET ORGANIZED OVER THE
MISSISSIPPI VALLEY TUES NIGHT BEFORE PUSHING NWD INTO THE GREAT
LAKES ON WED. THIS SYSTEM WILL DRAW EVEN MILDER AIR NWD INTO THE
REGION...AND PROVIDE A RAINY AND BREEZY CHRISTMAS EVE DAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS FROM WEST TO EAST ACROSS PA IS POSSIBLE LATE WED/WED
NIGHT. SCT SNOW SHOWERS WILL CONTINUE INTO THURS ACROSS MAINLY
NRN AND WRN PA.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
OPERATIONAL MODELS AND THE GEFS SHOWING 850HPA TEMPS ALREADY
BEGINNING TO RISE NEXT FRI.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
LLVL NWRLY FLOW AND OROGRAPHIC FORCING OF A SHALLOW MOIST LAYER
WILL CONTINUE TO PRODUCE PLENTY OF CLOUDS ACROSS THE NW 1/2 TO
2/3RDS OF THE STATE WITH MAINLY MVFR BKN-OVC CIGS THROUGH
TONIGHT. KJST AND KBFD MAY TEETER ON THE UPPER END OF IFR FOR A
FEW HOURS LATER TONIGHT /AFTER 06Z/. IN CONTRAST...THE SE PENN
AIRFIELDS SUCH AS KMDT...KTHV AND KLNS WILL SEE MAINLY VFR...WITH
SKY CONDITIONS VARYING SCT-BKN030-040.

NORTHWEST WINDS OF 10-15 KTS WITH HIGHER GUSTS WILL DECREASE TO 8
KTS OR LESS LATER TONIGHT AND SATURDAY.

HIGH PRESSURE BUILDS EAST ACROSS PENN SATURDAY...WITH BKN-OVC CIGS
VARYING BETWEEN MVFR OVER THE HIGHER TERRAIN OF THE NORTH AND
WEST...TO SCT-BKN VFR IN THE VALLEYS.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...EVANEGO
AVIATION...LAMBERT/CERU





000
FXUS61 KCTP 192342
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
642 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE WESTERN GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND...BRINGING DRY WEATHER WITH
LIGHTER WIND. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK
LIKELY BRINGING US RAIN AND WIND FOR CHRISTMAS EVE...THEN BLUSTERY
AND COLDER CONDITIONS FOR CHRISTMAS DAY WITH SCATTERED SNOW
SHOWERS.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK TRAPPED BELOW A
MODERATELY STRONG SUBSIDENCE INVERSION /BASED AT AROUND 2-3KFT
AGL/ WILL PERSIST ACROSS MUCH OF NORTHERN AND WESTERN PENNSYLVANIA
LATE TODAY INTO SATURDAY...WHILE PARTIAL CLEARING OCCURS ACROSS
THE LOWER SUSQ VALLEY AND SURROUNDING AREAS.

TEMPS WILL REMAIN STEADY THROUGH LATE THIS AFTERNOON UNDER THE
10-15 KT NWRLY FLOW. READINGS WILL VARY FROM THE MID TO UPPER 20S
ACROSS THE NORTHERN AND WESTERN MOUNTAINS...TO THE LOWER 40S IN
THE SOUTHEAST.

A WEAK SFC RIDGE WILL MOVE TO NEAR THE PENN/OHIO BORDER BY 12Z
SATURDAY...BUT THE WEAK WESTERLY ISENTROPIC LIFT ALONG THE 285K
THETA SFC...AND SOME SHALLOW MOISTURE BEING ADVECTED SWD INTO THE
NRN MTNS OF PENN FROM LAKE ONTARIO...WILL MAINTAIN MOSTLY CLOUDY
TO CLOUDY SKIES. LITTLE MORE THAN A FEW FLURRIES OR SPOTTY -FZDZ
WILL FALL FROM THIS THIN CLOUD LAYER ACROSS THE HIGHER TERRAIN OF
THE LAURELS AND INVOF KBFD.

AFTER A PTLY CLOUDY LATE AFTERNOON AND EVENING IN THE SE PART OF
THE CWA...A BKN LAYER OF STRATO CU IS EXPECTED TO DRIFT SE /OR
FORM/ ACROSS THE REGION OVERNIGHT.

DUE TO THE NW-SE GRADIENT OF DECREASING CLOUDS...LOW TEMPS AT
DAYBREAK SAT WILL BE IN A RATHER TIGHT RANGE...FROM THE UPPER
TEENS TO LOWER 20S ACROSS THE MOUNTAINS...TO THE LOWER 20S IN THE
SE

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
A RIDGE OF HIGH PRESSURE...LIGHTER WIND...AND ASSOC DRIER AIR
MASS WILL BUILD EAST ACROSS THE STATE SATURDAY...PROVIDING THE
AREA WITH FAIR WEATHER.

HIGH RES MODEL DATA CONTINUES TO PAINT A MOSTLY CLOUDY PICTURE FOR
MUCH OF THE REGION SATURDAY INTO SATURDAY NIGHT...THOUGH PERIODS
OF SUNSHINE ARE LIKELY THROUGHOUT THE CENTRAL RIDGE AND VALLEY
REGION...AND SUSQUEHANNA RIVER VALLEY.

WAA ALOFT IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE MISS VALLEY
WILL LIKELY SPREAD SOME THIN CIRRUS OVER THE LOWER/THIN STRATO CU
CLOUD DECK PRESENT ACROSS THE REGION SATURDAY. ALL 12Z OPERATIONAL
MODEL DATA CONTINUES TO SUPPORT A DRY DAY WITH SFC RIDGE AND LOW
PWAT AIRMASS OVR THE STATE. MAX TEMPS SHOULD BE FAIRLY CLOSE TO
SEASONAL NORMS NEAR 30 ACROSS THE MTNS...AND MID TO UPPER 30S IN
THE SE.

MOSTLY CLOUDY SKIES WITH LIGHT WIND SAT NIGHT WILL YIELD LOWS IN
THE LOWER 20S ACROSS THE MTNS...AND GENERALLY THE MID 20S
ELSEWHERE.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGH PRES WILL PROVIDE TRANQUIL WEATHER ON SUNDAY...WITH PARTLY TO
MOSTLY SUNNY SKIES AND SEASONABLE TEMPS. AFTER THAT...THE WEATHER
WILL BECOME INCREASINGLY UNSETTLED AS NEXT WEEK PROGRESSES.

CLOUDS WILL INCR SUNDAY NIGHT INTO MONDAY...AS HIGH PRES LOSES
ITS GRIP AND A WEAK AREA OF LOW PRES ORGANIZES OVER THE SERN UNITED
STATES. LIGHT PRECIP WILL WORK NWD INTO PENNSYLVANIA LATE MONDAY
INTO MONDAY NIGHT AND CONTINUE INTO TUES. INITIALLY...CONDS WILL
BE COLD ENOUGH FOR THE POSSIBILITY OF SOME WINTRY PRECIP.
HOWEVER...WARMER AIR WILL MAKE ITS WAY NWD LATER MONDAY NIGHT INTO
TUES AND GRADUALLY CHANGE ANY LINGERING PRECIP OVER TO PLAIN RAIN.

A MORE SIGNIFICANT STORM SYSTEM WILL GET ORGANIZED OVER THE
MISSISSIPPI VALLEY TUES NIGHT BEFORE PUSHING NWD INTO THE GREAT
LAKES ON WED. THIS SYSTEM WILL DRAW EVEN MILDER AIR NWD INTO THE
REGION...AND PROVIDE A RAINY AND BREEZY CHRISTMAS EVE DAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS FROM WEST TO EAST ACROSS PA IS POSSIBLE LATE WED/WED
NIGHT. SCT SNOW SHOWERS WILL CONTINUE INTO THURS ACROSS MAINLY
NRN AND WRN PA.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
OPERATIONAL MODELS AND THE GEFS SHOWING 850HPA TEMPS ALREADY
BEGINNING TO RISE NEXT FRI.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
LLVL NWRLY FLOW AND OROGRAPHIC FORCING OF A SHALLOW MOIST LAYER
WILL CONTINUE TO PRODUCE PLENTY OF CLOUDS ACROSS THE NW 1/2 TO
2/3RDS OF THE STATE WITH MAINLY MVFR BKN-OVC CIGS THROUGH
TONIGHT. KJST AND KBFD MAY TEETER ON THE UPPER END OF IFR FOR A
FEW HOURS LATER TONIGHT /AFTER 06Z/. IN CONTRAST...THE SE PENN
AIRFIELDS SUCH AS KMDT...KTHV AND KLNS WILL SEE MAINLY VFR...WITH
SKY CONDITIONS VARYING SCT-BKN030-040.

NORTHWEST WINDS OF 10-15 KTS WITH HIGHER GUSTS WILL DECREASE TO 8
KTS OR LESS LATER TONIGHT AND SATURDAY.

HIGH PRESSURE BUILDS EAST ACROSS PENN SATURDAY...WITH BKN-OVC CIGS
VARYING BETWEEN MVFR OVER THE HIGHER TERRAIN OF THE NORTH AND
WEST...TO SCT-BKN VFR IN THE VALLEYS.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...EVANEGO
AVIATION...LAMBERT/CERU




000
FXUS61 KCTP 192342
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
642 PM EST FRI DEC 19 2014

.SYNOPSIS...
HIGH PRESSURE CENTERED OVER THE WESTERN GREAT LAKES WILL SLIDE
EAST ACROSS PENNSYLVANIA THIS WEEKEND...BRINGING DRY WEATHER WITH
LIGHTER WIND. A DEEP UPPER TROUGH AND ASSOCIATED SFC LOW WILL LIFT
NORTHEAST THROUGH THE GREAT LAKES DURING THE MIDDLE OF NEXT WEEK
LIKELY BRINGING US RAIN AND WIND FOR CHRISTMAS EVE...THEN BLUSTERY
AND COLDER CONDITIONS FOR CHRISTMAS DAY WITH SCATTERED SNOW
SHOWERS.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
STUBBORN...ALBEIT SHALLOW STRATO CU CLOUD DECK TRAPPED BELOW A
MODERATELY STRONG SUBSIDENCE INVERSION /BASED AT AROUND 2-3KFT
AGL/ WILL PERSIST ACROSS MUCH OF NORTHERN AND WESTERN PENNSYLVANIA
LATE TODAY INTO SATURDAY...WHILE PARTIAL CLEARING OCCURS ACROSS
THE LOWER SUSQ VALLEY AND SURROUNDING AREAS.

TEMPS WILL REMAIN STEADY THROUGH LATE THIS AFTERNOON UNDER THE
10-15 KT NWRLY FLOW. READINGS WILL VARY FROM THE MID TO UPPER 20S
ACROSS THE NORTHERN AND WESTERN MOUNTAINS...TO THE LOWER 40S IN
THE SOUTHEAST.

A WEAK SFC RIDGE WILL MOVE TO NEAR THE PENN/OHIO BORDER BY 12Z
SATURDAY...BUT THE WEAK WESTERLY ISENTROPIC LIFT ALONG THE 285K
THETA SFC...AND SOME SHALLOW MOISTURE BEING ADVECTED SWD INTO THE
NRN MTNS OF PENN FROM LAKE ONTARIO...WILL MAINTAIN MOSTLY CLOUDY
TO CLOUDY SKIES. LITTLE MORE THAN A FEW FLURRIES OR SPOTTY -FZDZ
WILL FALL FROM THIS THIN CLOUD LAYER ACROSS THE HIGHER TERRAIN OF
THE LAURELS AND INVOF KBFD.

AFTER A PTLY CLOUDY LATE AFTERNOON AND EVENING IN THE SE PART OF
THE CWA...A BKN LAYER OF STRATO CU IS EXPECTED TO DRIFT SE /OR
FORM/ ACROSS THE REGION OVERNIGHT.

DUE TO THE NW-SE GRADIENT OF DECREASING CLOUDS...LOW TEMPS AT
DAYBREAK SAT WILL BE IN A RATHER TIGHT RANGE...FROM THE UPPER
TEENS TO LOWER 20S ACROSS THE MOUNTAINS...TO THE LOWER 20S IN THE
SE

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
A RIDGE OF HIGH PRESSURE...LIGHTER WIND...AND ASSOC DRIER AIR
MASS WILL BUILD EAST ACROSS THE STATE SATURDAY...PROVIDING THE
AREA WITH FAIR WEATHER.

HIGH RES MODEL DATA CONTINUES TO PAINT A MOSTLY CLOUDY PICTURE FOR
MUCH OF THE REGION SATURDAY INTO SATURDAY NIGHT...THOUGH PERIODS
OF SUNSHINE ARE LIKELY THROUGHOUT THE CENTRAL RIDGE AND VALLEY
REGION...AND SUSQUEHANNA RIVER VALLEY.

WAA ALOFT IN ADVANCE OF SHORTWAVE LIFTING OUT OF THE MISS VALLEY
WILL LIKELY SPREAD SOME THIN CIRRUS OVER THE LOWER/THIN STRATO CU
CLOUD DECK PRESENT ACROSS THE REGION SATURDAY. ALL 12Z OPERATIONAL
MODEL DATA CONTINUES TO SUPPORT A DRY DAY WITH SFC RIDGE AND LOW
PWAT AIRMASS OVR THE STATE. MAX TEMPS SHOULD BE FAIRLY CLOSE TO
SEASONAL NORMS NEAR 30 ACROSS THE MTNS...AND MID TO UPPER 30S IN
THE SE.

MOSTLY CLOUDY SKIES WITH LIGHT WIND SAT NIGHT WILL YIELD LOWS IN
THE LOWER 20S ACROSS THE MTNS...AND GENERALLY THE MID 20S
ELSEWHERE.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGH PRES WILL PROVIDE TRANQUIL WEATHER ON SUNDAY...WITH PARTLY TO
MOSTLY SUNNY SKIES AND SEASONABLE TEMPS. AFTER THAT...THE WEATHER
WILL BECOME INCREASINGLY UNSETTLED AS NEXT WEEK PROGRESSES.

CLOUDS WILL INCR SUNDAY NIGHT INTO MONDAY...AS HIGH PRES LOSES
ITS GRIP AND A WEAK AREA OF LOW PRES ORGANIZES OVER THE SERN UNITED
STATES. LIGHT PRECIP WILL WORK NWD INTO PENNSYLVANIA LATE MONDAY
INTO MONDAY NIGHT AND CONTINUE INTO TUES. INITIALLY...CONDS WILL
BE COLD ENOUGH FOR THE POSSIBILITY OF SOME WINTRY PRECIP.
HOWEVER...WARMER AIR WILL MAKE ITS WAY NWD LATER MONDAY NIGHT INTO
TUES AND GRADUALLY CHANGE ANY LINGERING PRECIP OVER TO PLAIN RAIN.

A MORE SIGNIFICANT STORM SYSTEM WILL GET ORGANIZED OVER THE
MISSISSIPPI VALLEY TUES NIGHT BEFORE PUSHING NWD INTO THE GREAT
LAKES ON WED. THIS SYSTEM WILL DRAW EVEN MILDER AIR NWD INTO THE
REGION...AND PROVIDE A RAINY AND BREEZY CHRISTMAS EVE DAY.

AS THIS SYSTEM DRIFTS NWD INTO SRN CANADA...COLDER AIR WILL WRAP
INTO THE REGION ON BLUSTERY WEST WINDS. A CHANGEOVER FROM RAIN TO
SNOW SHOWERS FROM WEST TO EAST ACROSS PA IS POSSIBLE LATE WED/WED
NIGHT. SCT SNOW SHOWERS WILL CONTINUE INTO THURS ACROSS MAINLY
NRN AND WRN PA.

THE CHILLIER AIRMASS LOOKS LIKE IT WILL BE SHORT-LIVED...WITH
OPERATIONAL MODELS AND THE GEFS SHOWING 850HPA TEMPS ALREADY
BEGINNING TO RISE NEXT FRI.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
LLVL NWRLY FLOW AND OROGRAPHIC FORCING OF A SHALLOW MOIST LAYER
WILL CONTINUE TO PRODUCE PLENTY OF CLOUDS ACROSS THE NW 1/2 TO
2/3RDS OF THE STATE WITH MAINLY MVFR BKN-OVC CIGS THROUGH
TONIGHT. KJST AND KBFD MAY TEETER ON THE UPPER END OF IFR FOR A
FEW HOURS LATER TONIGHT /AFTER 06Z/. IN CONTRAST...THE SE PENN
AIRFIELDS SUCH AS KMDT...KTHV AND KLNS WILL SEE MAINLY VFR...WITH
SKY CONDITIONS VARYING SCT-BKN030-040.

NORTHWEST WINDS OF 10-15 KTS WITH HIGHER GUSTS WILL DECREASE TO 8
KTS OR LESS LATER TONIGHT AND SATURDAY.

HIGH PRESSURE BUILDS EAST ACROSS PENN SATURDAY...WITH BKN-OVC CIGS
VARYING BETWEEN MVFR OVER THE HIGHER TERRAIN OF THE NORTH AND
WEST...TO SCT-BKN VFR IN THE VALLEYS.

OUTLOOK...

SUN...NO SIG WX EXPECTED.

MON...LOW CIGS WITH LGT RAIN/SNOW POSSIBLE. BECOMING BREEZY.

TUE...LOW CIGS WITH RAIN LIKELY. BREEZY.

WED...MILD WITH PERIODS OF RAIN OF VARYING INTENSITY...LEADING TO
MVFR TO IFR. ALSO...WINDY WITH LLWS.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...EVANEGO
AVIATION...LAMBERT/CERU





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