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000
FXUS61 KPBZ 191416
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
916 AM EST FRI DEC 19 2014

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

&&

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


&&

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

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
MVFR TO ISOLATED IFR CIGS WILL IMPROVE TO MVFR THIS AFTERNOON AND
CONTINUE TONIGHT.


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

&&

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

&&

$$









000
FXUS61 KPBZ 191416
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
916 AM EST FRI DEC 19 2014

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

&&

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


&&

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

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
MVFR TO ISOLATED IFR CIGS WILL IMPROVE TO MVFR THIS AFTERNOON AND
CONTINUE TONIGHT.


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

&&

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

&&

$$










000
FXUS61 KPBZ 191050
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
550 AM EST FRI DEC 19 2014

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

&&

.NEAR TERM /THROUGH TONIGHT/...
MOISTURE TRAPPED UNDER THE INVERSION NEAR H85 CONTINUES TO FALL OUT
AS FREEZING DRIZZLE MIXING AT TIMES WITH LIGHT SNOW. BEGINNING TO
SEE SOME REPORTS IN THE PITTSBURGH METRO AREA...AND FURTHER SOUTH
AND WEST INTO ERN OHIO. HAVE EXPANDED THE WINTER WEATHER ADVISORY TO
INCLUDE THIS AREA. THE BULK OF THIS ACTIVITY REMAINS JUST WEST OF
THE CWA BOUNDARY WHERE MOISTURE AVAILABILITY IS A LITTLE BETTER DUE
TO THE PROXIMITY TO LAKE ERIE.

RECENT RADAR TRENDS SHOW A LAKE-ENHANCED BAND NEAR CLE DISLODGE ITSELF
FROM THE SRN SHORELINE OF LAKE ERIE. THIS IS IN RESPONSE TO THE
WINDS VEERING TO NEARLY NORTHERLY AS THE LLVL SW TROF AXIS SWINGS
SOUTHWARD. WHILE THE INDIVIDUAL BAND IS NOT EXPECTED TO IMPACT OUR
AREA DIRECTLY...IT CAN BE USED AS A GOOD PROXY FOR WHERE THE
DOWNSTREAM MOISTURE IS ENTERING OUR FORECAST AREA. AS THIS BAND
CONTINUES TO PIVOT SOUTHWARD...EXPECT TO SEE LIGHT SNOW AND FREEZING
DRIZZLE REPORTS IN OUR AREA TO FOLLOW SUIT.

THE HI-RES MODELS DID A GREAT JOB HANDLING THE LLVL MOISTURE AND
PROGRESSION OF THE TROF...KEYING IN ON THE ATTENDANT MID-LEVEL
DEFORMATION ZONE TO GENERATE SHOWER ACTIVITY. AS IT CONTINUES IT
TREK SOUTH OF LAKE ERIE...THE MOISTURE BEGINS TO ERODE ALONG WITH
THE DEFORMATION ZONE GETTING WASHED OUT. WITH STILL ABUNDANT LLVL
MOISTURE AVAILABLE...WOULD EXPECT REPORTS OF DZ TO CONTINUE THROUGH
SUNRISE...BUT NOT MUCH BEYOND THAT. HAVE EXTENDED THE ADVISORY
THROUGH 9AM.

CLOUDS WILL CONTINUE TO PLAGUE THE CWA FOR YET ANOTHER DAY KEEPING
DAYTIME HIGHS IN CHECK. INCREASING SUBSIDENCE UNDER HIGH PRESSURE
WILL GRADUALLY LOWER INVERSION HEIGHTS THROUGH THE DAY FRIDAY
SQUASHING REMAINING PRECIPITATION CHANCES.
TAX

&&

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

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
UPDATED TAFS TO INCLUDE MENTION OF FREEZING DRIZZLE FOR SITES
NORTH OF INTERSTATE 70 THROUGH EARLY THIS MORNING BASED ON LATEST
OBS AND LATEST HI RES AND RAPID REFRESH GUIDANCE SHOWING
INDICATING MOISTURE IN THE COLUMN LIMITED TO LOWER LEVELS NOT COLD
ENOUGH FOR ICE CRYSTAL FORMATION...THUS...FINE MIST AND LIGHT
DRIZZLE EXPECTED THROUGH 9AM WILL REMAIN LIQUID AND FREEZE ON
CONTACT. DO NOT EXPECT ANY PERIODS OF RAPID ICE DEVELOPMENT BUT
WILL LIKELY FOR A LIGHT GLAZE OVER THE NEXT SEVERAL HOURS.
ICE POTENTIAL WILL LIKELY BE OVER BY MID MORNING AS MOISTURE POOL
BECOMES TOO SHALLOW...WITH CIG RESTRICTIONS LARGELY MVFR THROUGH
MUCH OF THE DAY...IMPROVING TO VFR STARTING LATE THIS AFTERNOON.


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

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR
     OHZ039>041-048>050.
PA...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR
     PAZ007>009-013>016-020>022.
WV...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR WVZ001.

&&

$$







000
FXUS61 KPBZ 190839
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
339 AM EST FRI DEC 19 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CURRENTLY TWO DIFFERENT TYPES OF PRECIPITATION BEING GENERATED
PRODUCED BY TWO DIFFERENT MODES OF GENERATION. LIGHT SNOW SHOWERS
EXIST ACROSS THE SOUTH AND HIGHER ELEVATIONS OF THE SOUTHEAST
PRODUCED BY SEEDER-FEEDER METHODS WITH MOISTURE FROM ABOUT
500MB-600MB SEEDING THE MOISTURE TRAPPED BELOW THE INVERSION AT
850MB. THE 00Z UPPER AIR SOUNDING SAMPLED THIS ENVIRONMENT RATHER
NICELY AND THE HI-RES MODELS HAVE PICKED UP ON THIS...EVEN
GENERATING QPF. AS THE SW TROF AXIS SWINGS THROUGH N TO S THE UPPER
LEVEL MOISTURE MOVES QUICKLY OUT WHILE DRYING UP. THIS SHOULD
EFFECTIVELY SQUASH ANY REMAINING SEEDER-FEEDER GENERATED SNOW
SHOWERS ACROSS OUR SOUTH.

ELSEWHERE...ACROSS THE NORTHERN TIER OF THE CWA THE BL MOISTURE
DEPTH HAS BEEN ENHANCED BY AN INJECTION OF UPSTREAM LAKE MOISTURE
THAT HAS RAISED INVERSION HEIGHTS. LAST NIGHT MODELS WERE INDICATING
A BL TOP TEMP IN THE -10C TO -11C RANGE WHICH WOULD BE COLD ENOUGH
TO PRODUCE ICE CRYSTALS AND GENERATE LIGHT SNOW. THE 00Z SOUNDING
VERIFIED THIS OCCURRENCE WITH 850MB TEMPS RIGHT AT -10C...WHICH WOULD
LEAD ONE TO BELIEVE THAT SNOW WOULD RESULT. HOWEVER...LOOKING AT RAP
BUFR SOUNDINGS...THE -10C ISOTHERM LAYER IS RATHER SMALL SPATIALLY
AT 850MB AND THE SAMPLE TAKE SEEMS MORE LIKE THE EXCEPTION THAN THE
RULE. IN ACTUALITY THE BL TOP TEMP IS CLOSER TO -8C WHICH KEEPS
SUPERCOOLED LIQUID INTO PLAY...THUS THE REPORTS OF FZDZ MIXING IN
WITH LIGHT SNOW. AN ADVISORY IS OUT FOR THE AREA DIRECTLY IMPACTED
BY THE FZDZ...AND DEPENDING ON THE DRIFT OF THE DOWN-LAKE
MOISTURE...AN EXPANSION SOUTHWARD MAY BE NECESSARY.

HI-RES MODELS INDICATING A FEED OF ENHANCED LLVL MOISTURE WILL SAG
SOUTHWARD THROUGH THE EARLY MORNING HOURS...REACHING THE PITTSBURGH
METRO AREA NEAR SUNRISE. THIS IS IN RESPONSE TO THE MI-LEVEL TROF
AXIS AND ATTENDANT MID-LEVEL DEFORMATION ZONE. AS IT CONTINUES IT
TREK SOUTH OF LAKE ERIE...THE MOISTURE BEGINS TO ERODE ALONG WITH
THE DEFORMATION ZONE GETTING WASHED OUT. ATTM...HAVE INCLUDED LIGHT
SNOW SHOWERS INTO THE METRO AND AREAS NW TO SE SURROUNDING. WILL SHY
AWAY FROM FZDZ MENTION FOR NOW...AS CONFIDENCE IS NOT HIGH IN THE
POTENTIAL FURTHER SOUTH. CLOUDS WILL CONTINUE TO PLAGUE THE CWA FOR
YET ANOTHER DAY.
TAX

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
UPDATED TAFS TO INCLUDE MENTION OF FREEZING DRIZZLE FOR SITES
NORTH OF INTERSTATE 70 THROUGH EARLY THIS MORNING BASED ON LATEST
OBS AND LATEST HI RES AND RAPID REFRESH GUIDANCE SHOWING
INDICATING MOISTURE IN THE COLUMN LIMITED TO LOWER LEVELS NOT COLD
ENOUGH FOR ICE CRYSTAL FORMATION...THUS...FINE MIST AND LIGHT
DRIZZLE EXPECTED THROUGH 9AM WILL REMAIN LIQUID AND FREEZE ON
CONTACT. DO NOT EXPECT ANY PERIODS OF RAPID ICE DEVELOPMENT BUT
WILL LIKELY FOR A LIGHT GLAZE OVER THE NEXT SEVERAL HOURS.
ICE POTENTIAL WILL LIKELY BE OVER BY MID MORNING AS MOISTURE POOL
BECOMES TOO SHALLOW...WITH CIG RESTRICTIONS LARGELY MVFR THROUGH
MUCH OF THE DAY...IMPROVING TO VFR STARTING LATE THIS AFTERNOON.


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

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR
     OHZ039>041-048>050.
PA...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR
     PAZ007>009-013>016-020>022.
WV...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR WVZ001.

&&

$$







000
FXUS61 KPBZ 190839
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
339 AM EST FRI DEC 19 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CURRENTLY TWO DIFFERENT TYPES OF PRECIPITATION BEING GENERATED
PRODUCED BY TWO DIFFERENT MODES OF GENERATION. LIGHT SNOW SHOWERS
EXIST ACROSS THE SOUTH AND HIGHER ELEVATIONS OF THE SOUTHEAST
PRODUCED BY SEEDER-FEEDER METHODS WITH MOISTURE FROM ABOUT
500MB-600MB SEEDING THE MOISTURE TRAPPED BELOW THE INVERSION AT
850MB. THE 00Z UPPER AIR SOUNDING SAMPLED THIS ENVIRONMENT RATHER
NICELY AND THE HI-RES MODELS HAVE PICKED UP ON THIS...EVEN
GENERATING QPF. AS THE SW TROF AXIS SWINGS THROUGH N TO S THE UPPER
LEVEL MOISTURE MOVES QUICKLY OUT WHILE DRYING UP. THIS SHOULD
EFFECTIVELY SQUASH ANY REMAINING SEEDER-FEEDER GENERATED SNOW
SHOWERS ACROSS OUR SOUTH.

ELSEWHERE...ACROSS THE NORTHERN TIER OF THE CWA THE BL MOISTURE
DEPTH HAS BEEN ENHANCED BY AN INJECTION OF UPSTREAM LAKE MOISTURE
THAT HAS RAISED INVERSION HEIGHTS. LAST NIGHT MODELS WERE INDICATING
A BL TOP TEMP IN THE -10C TO -11C RANGE WHICH WOULD BE COLD ENOUGH
TO PRODUCE ICE CRYSTALS AND GENERATE LIGHT SNOW. THE 00Z SOUNDING
VERIFIED THIS OCCURRENCE WITH 850MB TEMPS RIGHT AT -10C...WHICH WOULD
LEAD ONE TO BELIEVE THAT SNOW WOULD RESULT. HOWEVER...LOOKING AT RAP
BUFR SOUNDINGS...THE -10C ISOTHERM LAYER IS RATHER SMALL SPATIALLY
AT 850MB AND THE SAMPLE TAKE SEEMS MORE LIKE THE EXCEPTION THAN THE
RULE. IN ACTUALITY THE BL TOP TEMP IS CLOSER TO -8C WHICH KEEPS
SUPERCOOLED LIQUID INTO PLAY...THUS THE REPORTS OF FZDZ MIXING IN
WITH LIGHT SNOW. AN ADVISORY IS OUT FOR THE AREA DIRECTLY IMPACTED
BY THE FZDZ...AND DEPENDING ON THE DRIFT OF THE DOWN-LAKE
MOISTURE...AN EXPANSION SOUTHWARD MAY BE NECESSARY.

HI-RES MODELS INDICATING A FEED OF ENHANCED LLVL MOISTURE WILL SAG
SOUTHWARD THROUGH THE EARLY MORNING HOURS...REACHING THE PITTSBURGH
METRO AREA NEAR SUNRISE. THIS IS IN RESPONSE TO THE MI-LEVEL TROF
AXIS AND ATTENDANT MID-LEVEL DEFORMATION ZONE. AS IT CONTINUES IT
TREK SOUTH OF LAKE ERIE...THE MOISTURE BEGINS TO ERODE ALONG WITH
THE DEFORMATION ZONE GETTING WASHED OUT. ATTM...HAVE INCLUDED LIGHT
SNOW SHOWERS INTO THE METRO AND AREAS NW TO SE SURROUNDING. WILL SHY
AWAY FROM FZDZ MENTION FOR NOW...AS CONFIDENCE IS NOT HIGH IN THE
POTENTIAL FURTHER SOUTH. CLOUDS WILL CONTINUE TO PLAGUE THE CWA FOR
YET ANOTHER DAY.
TAX

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
UPDATED TAFS TO INCLUDE MENTION OF FREEZING DRIZZLE FOR SITES
NORTH OF INTERSTATE 70 THROUGH EARLY THIS MORNING BASED ON LATEST
OBS AND LATEST HI RES AND RAPID REFRESH GUIDANCE SHOWING
INDICATING MOISTURE IN THE COLUMN LIMITED TO LOWER LEVELS NOT COLD
ENOUGH FOR ICE CRYSTAL FORMATION...THUS...FINE MIST AND LIGHT
DRIZZLE EXPECTED THROUGH 9AM WILL REMAIN LIQUID AND FREEZE ON
CONTACT. DO NOT EXPECT ANY PERIODS OF RAPID ICE DEVELOPMENT BUT
WILL LIKELY FOR A LIGHT GLAZE OVER THE NEXT SEVERAL HOURS.
ICE POTENTIAL WILL LIKELY BE OVER BY MID MORNING AS MOISTURE POOL
BECOMES TOO SHALLOW...WITH CIG RESTRICTIONS LARGELY MVFR THROUGH
MUCH OF THE DAY...IMPROVING TO VFR STARTING LATE THIS AFTERNOON.


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

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR
     OHZ039>041-048>050.
PA...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR
     PAZ007>009-013>016-020>022.
WV...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR WVZ001.

&&

$$








000
FXUS61 KPBZ 190743
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
243 AM EST FRI DEC 19 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CURRENTLY TWO DIFFERENT TYPES OF PRECIPITATION BEING GENERATED
PRODUCED BY TWO DIFFERENT MODES OF GENERATION. LIGHT SNOW SHOWERS
EXIST ACROSS THE SOUTH AND HIGHER ELEVATIONS OF THE SOUTHEAST
PRODUCED BY SEEDER-FEEDER METHODS WITH MOISTURE FROM ABOUT
500MB-600MB SEEDING THE MOISTURE TRAPPED BELOW THE INVERSION AT
850MB. THE 00Z UPPER AIR SOUNDING SAMPLED THIS ENVIRONMENT RATHER
NICELY AND THE HI-RES MODELS HAVE PICKED UP ON THIS...EVEN
GENERATING QPF. AS THE SW TROF AXIS SWINGS THROUGH N TO S THE UPPER
LEVEL MOISTURE MOVES QUICKLY OUT WHILE DRYING UP. THIS SHOULD
EFFECTIVELY SQUASH ANY REMAINING SEEDER-FEEDER GENERATED SNOW
SHOWERS ACROSS OUR SOUTH.

ELSEWHERE...ACROSS THE NORTHERN TIER OF THE CWA THE BL MOISTURE
DEPTH HAS BEEN ENHANCED BY AN INJECTION OF UPSTREAM LAKE MOISTURE
THAT HAS RAISED INVERSION HEIGHTS. LAST NIGHT MODELS WERE INDICATING
A BL TOP TEMP IN THE -10C TO -11C RANGE WHICH WOULD BE COLD ENOUGH
TO PRODUCE ICE CRYSTALS AND GENERATE LIGHT SNOW. THE 00Z SOUNDING
VERIFIED THIS OCCURRENCE WITH 850MB TEMPS RIGHT AT -10C...WHICH WOULD
LEAD ONE TO BELIEVE THAT SNOW WOULD RESULT. HOWEVER...LOOKING AT RAP
BUFR SOUNDINGS...THE -10C ISOTHERM LAYER IS RATHER SMALL SPATIALLY
AT 850MB AND THE SAMPLE TAKE SEEMS MORE LIKE THE EXCEPTION THAN THE
RULE. IN ACTUALITY THE BL TOP TEMP IS CLOSER TO -8C WHICH KEEPS
SUPERCOOLED LIQUID INTO PLAY...THUS THE REPORTS OF FZDZ MIXING IN
WITH LIGHT SNOW. AN ADVISORY IS OUT FOR THE AREA DIRECTLY IMPACTED
BY THE FZDZ...AND DEPENDING ON THE DRIFT OF THE DOWN-LAKE
MOISTURE...AN EXPANSION SOUTHWARD MAY BE NECESSARY.

HI-RES MODELS INDICATING A FEED OF ENHANCED LLVL MOISTURE WILL SAG
SOUTHWARD THROUGH THE EARLY MORNING HOURS...REACHING THE PITTSBURGH
METRO AREA NEAR SUNRISE. THIS IS IN RESPONSE TO THE MI-LEVEL TROF
AXIS AND ATTENDANT MID-LEVEL DEFORMATION ZONE. AS IT CONTINUES IT
TREK SOUTH OF LAKE ERIE...THE MOISTURE BEGINS TO ERODE ALONG WITH
THE DEFORMATION ZONE GETTING WASHED OUT. ATTM...HAVE INCLUDED LIGHT
SNOW SHOWERS INTO THE METRO AND AREAS NW TO SE SURROUNDING. WILL SHY
AWAY FROM FZDZ MENTION FOR NOW...AS CONFIDENCE IS NOT HIGH IN THE
POTENTIAL FURTHER SOUTH. CLOUDS WILL CONTINUE TO PLAGUE THE CWA FOR
YET ANOTHER DAY.
TAX

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS EXPECTED OVERNIGHT WITH SITES ALONG AND NORTH OF
INTERSTATE 80 POTENTIALLY SEEING IFR CIGS DEVELOP DURING PERIODS
OF LIGHT SNOW. THERE IS A SLIGHT CHANCE THAT LIGHT FREEZING
DRIZZLE MAY OCCUR AND SPREAD FROM NORTH TO SOUTH OVERNIGHT AS
MOISTURE DECREASES ALOFT LEAVING ONLY LOW LEVEL MOISTURE IN PLACE
TRAPPED UNDER THE INVERSION IN TEMPERATURES NOT SUFFICIENTLY COLD
FOR ICE CRYSTALS TO DEVELOP...BUT CONFIDENCE IS NOT HIGH ENOUGH
TO INCLUDE IN TAFS AT THIS TIME. POTENTIAL FOR FREEZING DRIZZLE
WILL LIKELY BE OVER BY MID MORNING AS MOISTURE POOL BECOMES TOO
SHALLOW.


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

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR
     OHZ039>041-048>050.
PA...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR
     PAZ007>009-013>016-020>022.
WV...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR WVZ001.

&&

$$







000
FXUS61 KPBZ 190743
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
243 AM EST FRI DEC 19 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CURRENTLY TWO DIFFERENT TYPES OF PRECIPITATION BEING GENERATED
PRODUCED BY TWO DIFFERENT MODES OF GENERATION. LIGHT SNOW SHOWERS
EXIST ACROSS THE SOUTH AND HIGHER ELEVATIONS OF THE SOUTHEAST
PRODUCED BY SEEDER-FEEDER METHODS WITH MOISTURE FROM ABOUT
500MB-600MB SEEDING THE MOISTURE TRAPPED BELOW THE INVERSION AT
850MB. THE 00Z UPPER AIR SOUNDING SAMPLED THIS ENVIRONMENT RATHER
NICELY AND THE HI-RES MODELS HAVE PICKED UP ON THIS...EVEN
GENERATING QPF. AS THE SW TROF AXIS SWINGS THROUGH N TO S THE UPPER
LEVEL MOISTURE MOVES QUICKLY OUT WHILE DRYING UP. THIS SHOULD
EFFECTIVELY SQUASH ANY REMAINING SEEDER-FEEDER GENERATED SNOW
SHOWERS ACROSS OUR SOUTH.

ELSEWHERE...ACROSS THE NORTHERN TIER OF THE CWA THE BL MOISTURE
DEPTH HAS BEEN ENHANCED BY AN INJECTION OF UPSTREAM LAKE MOISTURE
THAT HAS RAISED INVERSION HEIGHTS. LAST NIGHT MODELS WERE INDICATING
A BL TOP TEMP IN THE -10C TO -11C RANGE WHICH WOULD BE COLD ENOUGH
TO PRODUCE ICE CRYSTALS AND GENERATE LIGHT SNOW. THE 00Z SOUNDING
VERIFIED THIS OCCURRENCE WITH 850MB TEMPS RIGHT AT -10C...WHICH WOULD
LEAD ONE TO BELIEVE THAT SNOW WOULD RESULT. HOWEVER...LOOKING AT RAP
BUFR SOUNDINGS...THE -10C ISOTHERM LAYER IS RATHER SMALL SPATIALLY
AT 850MB AND THE SAMPLE TAKE SEEMS MORE LIKE THE EXCEPTION THAN THE
RULE. IN ACTUALITY THE BL TOP TEMP IS CLOSER TO -8C WHICH KEEPS
SUPERCOOLED LIQUID INTO PLAY...THUS THE REPORTS OF FZDZ MIXING IN
WITH LIGHT SNOW. AN ADVISORY IS OUT FOR THE AREA DIRECTLY IMPACTED
BY THE FZDZ...AND DEPENDING ON THE DRIFT OF THE DOWN-LAKE
MOISTURE...AN EXPANSION SOUTHWARD MAY BE NECESSARY.

HI-RES MODELS INDICATING A FEED OF ENHANCED LLVL MOISTURE WILL SAG
SOUTHWARD THROUGH THE EARLY MORNING HOURS...REACHING THE PITTSBURGH
METRO AREA NEAR SUNRISE. THIS IS IN RESPONSE TO THE MI-LEVEL TROF
AXIS AND ATTENDANT MID-LEVEL DEFORMATION ZONE. AS IT CONTINUES IT
TREK SOUTH OF LAKE ERIE...THE MOISTURE BEGINS TO ERODE ALONG WITH
THE DEFORMATION ZONE GETTING WASHED OUT. ATTM...HAVE INCLUDED LIGHT
SNOW SHOWERS INTO THE METRO AND AREAS NW TO SE SURROUNDING. WILL SHY
AWAY FROM FZDZ MENTION FOR NOW...AS CONFIDENCE IS NOT HIGH IN THE
POTENTIAL FURTHER SOUTH. CLOUDS WILL CONTINUE TO PLAGUE THE CWA FOR
YET ANOTHER DAY.
TAX

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS EXPECTED OVERNIGHT WITH SITES ALONG AND NORTH OF
INTERSTATE 80 POTENTIALLY SEEING IFR CIGS DEVELOP DURING PERIODS
OF LIGHT SNOW. THERE IS A SLIGHT CHANCE THAT LIGHT FREEZING
DRIZZLE MAY OCCUR AND SPREAD FROM NORTH TO SOUTH OVERNIGHT AS
MOISTURE DECREASES ALOFT LEAVING ONLY LOW LEVEL MOISTURE IN PLACE
TRAPPED UNDER THE INVERSION IN TEMPERATURES NOT SUFFICIENTLY COLD
FOR ICE CRYSTALS TO DEVELOP...BUT CONFIDENCE IS NOT HIGH ENOUGH
TO INCLUDE IN TAFS AT THIS TIME. POTENTIAL FOR FREEZING DRIZZLE
WILL LIKELY BE OVER BY MID MORNING AS MOISTURE POOL BECOMES TOO
SHALLOW.


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

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR
     OHZ039>041-048>050.
PA...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR
     PAZ007>009-013>016-020>022.
WV...WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR WVZ001.

&&

$$








000
FXUS61 KPBZ 190626
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
126 AM EST FRI DEC 19 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /THROUGH TODAY/...
CURRENTLY TWO DIFFERENT TYPES OF PRECIPITATION BEING GENERATED
PRODUCED BY TWO DIFFERENT MODES OF GENERATION. LIGHT SNOW SHOWERS
EXIST ACROSS THE SOUTH AND HIGHER ELEVATIONS OF THE SOUTHEAST
PRODUCED BY SEEDER-FEEDER METHODS WITH MOISTURE FROM ABOUT
500MB-600MB SEEDING THE MOISTURE TRAPPED BELOW THE INVERSION AT
850MB. THE 00Z UPPER AIR SOUNDING SAMPLED THIS ENVIRONMENT RATHER
NICELY AND THE HI-RES MODELS HAVE PICKED UP ON THIS...EVEN
GENERATING QPF. AS THE SW TROF AXIS SWINGS THROUGH N TO S THE UPPER
LEVEL MOISTURE MOVES QUICKLY OUT WHILE DRYING UP. THIS SHOULD
EFFECTIVELY SQUASH ANY REMAINING SEEDER-FEEDER GENERATED SNOW
SHOWERS ACROSS OUR SOUTH.

ELSEWHERE...ACROSS THE NORTHERN TIER OF THE CWA THE BL MOISTURE
DEPTH HAS BEEN ENHANCED BY AN INJECTION OF UPSTREAM LAKE MOISTURE
THAT HAS RAISED INVERSION HEIGHTS. LAST NIGHT MODELS WERE INDICATING
A BL TOP TEMP IN THE -10C TO -11C RANGE WHICH WOULD BE COLD ENOUGH
TO PRODUCE ICE CRYSTALS AND GENERATE LIGHT SNOW. THE 00Z SOUNDING
VERIFIED THIS OCCURRENCE WITH 850MB TEMPS RIGHT AT -10C...WHICH WOULD
LEAD ONE TO BELIEVE THAT SNOW WOULD RESULT. HOWEVER...LOOKING AT RAP
BUFR SOUNDINGS...THE -10C ISOTHERM LAYER IS RATHER SMALL SPATIALLY
AT 850MB AND THE SAMPLE TAKE SEEMS MORE LIKE THE EXCEPTION THAN THE
RULE. IN ACTUALITY THE BL TOP TEMP IS CLOSER TO -8C WHICH KEEPS
SUPERCOOLED LIQUID INTO PLAY...THUS THE REPORTS OF FZDZ MIXING IN
WITH LIGHT SNOW. AN ADVISORY IS OUT FOR THE AREA DIRECTLY IMPACTED
BY THE FZDZ...AND DEPENDING ON THE DRIFT OF THE DOWN-LAKE
MOISTURE...AN EXPANSION SOUTHWARD MAY BE NECESSARY.

HI-RES MODELS INDICATING A FEED OF ENHANCED LLVL MOISTURE WILL SAG
SOUTHWARD THROUGH THE EARLY MORNING HOURS...REACHING THE PITTSBURGH
METRO AREA NEAR SUNRISE. THIS IS IN RESPONSE TO THE MI-LEVEL TROF
AXIS AND ATTENDANT MID-LEVEL DEFORMATION ZONE. AS IT CONTINUES IT
TREK SOUTH OF LAKE ERIE...THE MOISTURE BEGINS TO ERODE ALONG WITH
THE DEFORMATION ZONE GETTING WASHED OUT. ATTM...HAVE INCLUDED LIGHT
SNOW SHOWERS INTO THE METRO AND AREAS NW TO SE SURROUNDING. WILL SHY
AWAY FROM FZDZ MENTION FOR NOW...AS CONFIDENCE IS NOT HIGH IN THE
POTENTIAL FURTHER SOUTH. CLOUDS WILL CONTINUE TO PLAGUE THE CWA FOR
YET ANOTHER DAY.
TAX

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS EXPECTED OVERNIGHT WITH SITES ALONG AND NORTH OF
INTERSTATE 80 POTENTIALLY SEEING IFR CIGS DEVELOP DURING PERIODS
OF LIGHT SNOW. THERE IS A SLIGHT CHANCE THAT LIGHT FREEZING
DRIZZLE MAY OCCUR AND SPREAD FROM NORTH TO SOUTH OVERNIGHT AS
MOISTURE DECREASES ALOFT LEAVING ONLY LOW LEVEL MOISTURE IN PLACE
TRAPPED UNDER THE INVERSION IN TEMPERATURES NOT SUFFICIENTLY COLD
FOR ICE CRYSTALS TO DEVELOP...BUT CONFIDENCE IS NOT HIGH ENOUGH
TO INCLUDE IN TAFS AT THIS TIME. POTENTIAL FOR FREEZING DRIZZLE
WILL LIKELY BE OVER BY MID MORNING AS MOISTURE POOL BECOMES TOO
SHALLOW.


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

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     PAZ007>009-013>016-022.
WV...NONE.

&&

$$








000
FXUS61 KPBZ 190626
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
126 AM EST FRI DEC 19 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /THROUGH TODAY/...
CURRENTLY TWO DIFFERENT TYPES OF PRECIPITATION BEING GENERATED
PRODUCED BY TWO DIFFERENT MODES OF GENERATION. LIGHT SNOW SHOWERS
EXIST ACROSS THE SOUTH AND HIGHER ELEVATIONS OF THE SOUTHEAST
PRODUCED BY SEEDER-FEEDER METHODS WITH MOISTURE FROM ABOUT
500MB-600MB SEEDING THE MOISTURE TRAPPED BELOW THE INVERSION AT
850MB. THE 00Z UPPER AIR SOUNDING SAMPLED THIS ENVIRONMENT RATHER
NICELY AND THE HI-RES MODELS HAVE PICKED UP ON THIS...EVEN
GENERATING QPF. AS THE SW TROF AXIS SWINGS THROUGH N TO S THE UPPER
LEVEL MOISTURE MOVES QUICKLY OUT WHILE DRYING UP. THIS SHOULD
EFFECTIVELY SQUASH ANY REMAINING SEEDER-FEEDER GENERATED SNOW
SHOWERS ACROSS OUR SOUTH.

ELSEWHERE...ACROSS THE NORTHERN TIER OF THE CWA THE BL MOISTURE
DEPTH HAS BEEN ENHANCED BY AN INJECTION OF UPSTREAM LAKE MOISTURE
THAT HAS RAISED INVERSION HEIGHTS. LAST NIGHT MODELS WERE INDICATING
A BL TOP TEMP IN THE -10C TO -11C RANGE WHICH WOULD BE COLD ENOUGH
TO PRODUCE ICE CRYSTALS AND GENERATE LIGHT SNOW. THE 00Z SOUNDING
VERIFIED THIS OCCURRENCE WITH 850MB TEMPS RIGHT AT -10C...WHICH WOULD
LEAD ONE TO BELIEVE THAT SNOW WOULD RESULT. HOWEVER...LOOKING AT RAP
BUFR SOUNDINGS...THE -10C ISOTHERM LAYER IS RATHER SMALL SPATIALLY
AT 850MB AND THE SAMPLE TAKE SEEMS MORE LIKE THE EXCEPTION THAN THE
RULE. IN ACTUALITY THE BL TOP TEMP IS CLOSER TO -8C WHICH KEEPS
SUPERCOOLED LIQUID INTO PLAY...THUS THE REPORTS OF FZDZ MIXING IN
WITH LIGHT SNOW. AN ADVISORY IS OUT FOR THE AREA DIRECTLY IMPACTED
BY THE FZDZ...AND DEPENDING ON THE DRIFT OF THE DOWN-LAKE
MOISTURE...AN EXPANSION SOUTHWARD MAY BE NECESSARY.

HI-RES MODELS INDICATING A FEED OF ENHANCED LLVL MOISTURE WILL SAG
SOUTHWARD THROUGH THE EARLY MORNING HOURS...REACHING THE PITTSBURGH
METRO AREA NEAR SUNRISE. THIS IS IN RESPONSE TO THE MI-LEVEL TROF
AXIS AND ATTENDANT MID-LEVEL DEFORMATION ZONE. AS IT CONTINUES IT
TREK SOUTH OF LAKE ERIE...THE MOISTURE BEGINS TO ERODE ALONG WITH
THE DEFORMATION ZONE GETTING WASHED OUT. ATTM...HAVE INCLUDED LIGHT
SNOW SHOWERS INTO THE METRO AND AREAS NW TO SE SURROUNDING. WILL SHY
AWAY FROM FZDZ MENTION FOR NOW...AS CONFIDENCE IS NOT HIGH IN THE
POTENTIAL FURTHER SOUTH. CLOUDS WILL CONTINUE TO PLAGUE THE CWA FOR
YET ANOTHER DAY.
TAX

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS EXPECTED OVERNIGHT WITH SITES ALONG AND NORTH OF
INTERSTATE 80 POTENTIALLY SEEING IFR CIGS DEVELOP DURING PERIODS
OF LIGHT SNOW. THERE IS A SLIGHT CHANCE THAT LIGHT FREEZING
DRIZZLE MAY OCCUR AND SPREAD FROM NORTH TO SOUTH OVERNIGHT AS
MOISTURE DECREASES ALOFT LEAVING ONLY LOW LEVEL MOISTURE IN PLACE
TRAPPED UNDER THE INVERSION IN TEMPERATURES NOT SUFFICIENTLY COLD
FOR ICE CRYSTALS TO DEVELOP...BUT CONFIDENCE IS NOT HIGH ENOUGH
TO INCLUDE IN TAFS AT THIS TIME. POTENTIAL FOR FREEZING DRIZZLE
WILL LIKELY BE OVER BY MID MORNING AS MOISTURE POOL BECOMES TOO
SHALLOW.


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

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     PAZ007>009-013>016-022.
WV...NONE.

&&

$$







000
FXUS61 KPBZ 190603
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
103 AM EST FRI DEC 19 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AN UTTERLY POOR SNOW CRYSTAL GROWTH HABIT EXISTS OVER THE CWA THIS
EVENING...AS EVIDENCED BY THE PINHEAD SIZED SNOWFLAKES/GRAINS THAT
HAVE BEEN SCATTERED ACROSS THE AREA IN THE FORM OF "FLURRIES." IN
ADDITION...AREAS JUST TO THE NORTH AND NORTHWEST OF OUR CWA HAVE
STARTED TO REPORT FREEZING DRIZZLE. THIS SEEMS LIKELY TO CONTINUE
TO FILTER INTO AT LEAST THE NORTHERN REACHES OF THE CWA AS
MOISTURE INCREASES...BUT STILL LITTLE MOISTURE EXISTS ABOVE ABOUT
THE -8C ISOTHERM. AS SUCH...WHILE DEEPER MOISTURE MAY ALLOW SOME
TREND TOWARD SNOW SHOWER ACTIVITY...IT SEEMS INSUFFICIENT TO
PRECLUDE FREEZING DRIZZLE FROM CONTINUING TO DEVELOP IN THE
NORTHERN PORTIONS OF THE CWA.

ADDITIONALLY...WITH AN INCOMING SHORT WAVE TROUGH AND A BIT OF
ELEVATED MOISTURE...SOME SEEDER-FEEDER TYPE OF SNOW FLURRY ACTION
DOES SEEM POSSIBLE FOR A SHORT WINDOW AS THE WAVE TRACKS
THROUGH...HOWEVER MODEL CROSS SECTIONS...TIME HEIGHT
SECTIONS...AND PLAN DEPICTIONS ALL GENERALLY REVEAL A QUICK TREND
TOWARD ZERO MICROBARS/SEC OF LAYER NEGATIVE OMEGA VALUES BETWEEN
00Z AND 06Z THIS EVENING. AS A RESULT...WITH DRY AIR BETWEEN THE
TWO MOIST LAYERS...WEAKENING LIFT ALOFT...AND POOR CRYSTAL GROWTH
BELOW...IT WOULD SEEM JUST A GENERAL EXPANSION IN THE FLURRIES FOR
A FEW HOURS AS THE WAVE TRACKS THROUGH SHOULD BE THE MAIN PROBLEM
FOR THE NIGHT OVER THE REST OF THE CWA. UNFORTUNATELY...ROAD
TEMPERATURES HAVE TRENDED NEAR FREEZING THROUGH THE EVENING...SO
REPORTS OF NUMEROUS ACCIDENTS HAVE COME IN ACROSS THE I-70 AND
SOUTH CORRIDOR AS LIGHT SNOW INITIALLY MELTED THEN REFROZE ON
ROADWAYS. LUCKILY ENOUGH...THIS WAVE IS TRACKING THROUGH RATHER
QUICKLY...AND AFTER ITS PASSAGE...EVEN BOUNDARY LAYER RH VALUES
START TO FALL OFF A BIT...SO IT WOULD SEEM EVEN THE POOR GROWTH
HABIT MAY DETERIORATE BY MORNING. FRIES

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS EXPECTED OVERNIGHT WITH SITES ALONG AND NORTH OF
INTERSTATE 80 POTENTIALLY SEEING IFR CIGS DEVELOP DURING PERIODS
OF LIGHT SNOW. THERE IS A SLIGHT CHANCE THAT LIGHT FREEZING
DRIZZLE MAY OCCUR AND SPREAD FROM NORTH TO SOUTH OVERNIGHT AS
MOISTURE DECREASES ALOFT LEAVING ONLY LOW LEVEL MOISTURE IN PLACE
TRAPPED UNDER THE INVERSION IN TEMPERATURES NOT SUFFICIENTLY COLD
FOR ICE CRYSTALS TO DEVELOP...BUT CONFIDENCE IS NOT HIGH ENOUGH
TO INCLUDE IN TAFS AT THIS TIME. POTENTIAL FOR FREEZING DRIZZLE
WILL LIKELY BE OVER BY MID MORNING AS MOISTURE POOL BECOMES TOO
SHALLOW.


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

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     PAZ007>009-013>016-022.
WV...NONE.

&&

$$








000
FXUS61 KPBZ 190603
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
103 AM EST FRI DEC 19 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AN UTTERLY POOR SNOW CRYSTAL GROWTH HABIT EXISTS OVER THE CWA THIS
EVENING...AS EVIDENCED BY THE PINHEAD SIZED SNOWFLAKES/GRAINS THAT
HAVE BEEN SCATTERED ACROSS THE AREA IN THE FORM OF "FLURRIES." IN
ADDITION...AREAS JUST TO THE NORTH AND NORTHWEST OF OUR CWA HAVE
STARTED TO REPORT FREEZING DRIZZLE. THIS SEEMS LIKELY TO CONTINUE
TO FILTER INTO AT LEAST THE NORTHERN REACHES OF THE CWA AS
MOISTURE INCREASES...BUT STILL LITTLE MOISTURE EXISTS ABOVE ABOUT
THE -8C ISOTHERM. AS SUCH...WHILE DEEPER MOISTURE MAY ALLOW SOME
TREND TOWARD SNOW SHOWER ACTIVITY...IT SEEMS INSUFFICIENT TO
PRECLUDE FREEZING DRIZZLE FROM CONTINUING TO DEVELOP IN THE
NORTHERN PORTIONS OF THE CWA.

ADDITIONALLY...WITH AN INCOMING SHORT WAVE TROUGH AND A BIT OF
ELEVATED MOISTURE...SOME SEEDER-FEEDER TYPE OF SNOW FLURRY ACTION
DOES SEEM POSSIBLE FOR A SHORT WINDOW AS THE WAVE TRACKS
THROUGH...HOWEVER MODEL CROSS SECTIONS...TIME HEIGHT
SECTIONS...AND PLAN DEPICTIONS ALL GENERALLY REVEAL A QUICK TREND
TOWARD ZERO MICROBARS/SEC OF LAYER NEGATIVE OMEGA VALUES BETWEEN
00Z AND 06Z THIS EVENING. AS A RESULT...WITH DRY AIR BETWEEN THE
TWO MOIST LAYERS...WEAKENING LIFT ALOFT...AND POOR CRYSTAL GROWTH
BELOW...IT WOULD SEEM JUST A GENERAL EXPANSION IN THE FLURRIES FOR
A FEW HOURS AS THE WAVE TRACKS THROUGH SHOULD BE THE MAIN PROBLEM
FOR THE NIGHT OVER THE REST OF THE CWA. UNFORTUNATELY...ROAD
TEMPERATURES HAVE TRENDED NEAR FREEZING THROUGH THE EVENING...SO
REPORTS OF NUMEROUS ACCIDENTS HAVE COME IN ACROSS THE I-70 AND
SOUTH CORRIDOR AS LIGHT SNOW INITIALLY MELTED THEN REFROZE ON
ROADWAYS. LUCKILY ENOUGH...THIS WAVE IS TRACKING THROUGH RATHER
QUICKLY...AND AFTER ITS PASSAGE...EVEN BOUNDARY LAYER RH VALUES
START TO FALL OFF A BIT...SO IT WOULD SEEM EVEN THE POOR GROWTH
HABIT MAY DETERIORATE BY MORNING. FRIES

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS EXPECTED OVERNIGHT WITH SITES ALONG AND NORTH OF
INTERSTATE 80 POTENTIALLY SEEING IFR CIGS DEVELOP DURING PERIODS
OF LIGHT SNOW. THERE IS A SLIGHT CHANCE THAT LIGHT FREEZING
DRIZZLE MAY OCCUR AND SPREAD FROM NORTH TO SOUTH OVERNIGHT AS
MOISTURE DECREASES ALOFT LEAVING ONLY LOW LEVEL MOISTURE IN PLACE
TRAPPED UNDER THE INVERSION IN TEMPERATURES NOT SUFFICIENTLY COLD
FOR ICE CRYSTALS TO DEVELOP...BUT CONFIDENCE IS NOT HIGH ENOUGH
TO INCLUDE IN TAFS AT THIS TIME. POTENTIAL FOR FREEZING DRIZZLE
WILL LIKELY BE OVER BY MID MORNING AS MOISTURE POOL BECOMES TOO
SHALLOW.


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

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     PAZ007>009-013>016-022.
WV...NONE.

&&

$$







000
FXUS61 KPBZ 190343
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1043 PM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AN UTTERLY POOR SNOW CRYSTAL GROWTH HABIT EXISTS OVER THE CWA THIS
EVENING...AS EVIDENCED BY THE PINHEAD SIZED SNOWFLAKES/GRAINS THAT
HAVE BEEN SCATTERED ACROSS THE AREA IN THE FORM OF "FLURRIES." IN
ADDITION...AREAS JUST TO THE NORTH AND NORTHWEST OF OUR CWA HAVE
STARTED TO REPORT FREEZING DRIZZLE. THIS SEEMS LIKELY TO CONTINUE
TO FILTER INTO AT LEAST THE NORTHERN REACHES OF THE CWA AS
MOISTURE INCREASES...BUT STILL LITTLE MOISTURE EXISTS ABOVE ABOUT
THE -8C ISOTHERM. AS SUCH...WHILE DEEPER MOISTURE MAY ALLOW SOME
TREND TOWARD SNOW SHOWER ACTIVITY...IT SEEMS INSUFFICIENT TO
PRECLUDE FREEZING DRIZZLE FROM CONTINUING TO DEVELOP IN THE
NORTHERN PORTIONS OF THE CWA.

ADDITIONALLY...WITH AN INCOMING SHORT WAVE TROUGH AND A BIT OF
ELEVATED MOISTURE...SOME SEEDER-FEEDER TYPE OF SNOW FLURRY ACTION
DOES SEEM POSSIBLE FOR A SHORT WINDOW AS THE WAVE TRACKS
THROUGH...HOWEVER MODEL CROSS SECTIONS...TIME HEIGHT
SECTIONS...AND PLAN DEPICTIONS ALL GENERALLY REVEAL A QUICK TREND
TOWARD ZERO MICROBARS/SEC OF LAYER NEGATIVE OMEGA VALUES BETWEEN
00Z AND 06Z THIS EVENING. AS A RESULT...WITH DRY AIR BETWEEN THE
TWO MOIST LAYERS...WEAKENING LIFT ALOFT...AND POOR CRYSTAL GROWTH
BELOW...IT WOULD SEEM JUST A GENERAL EXPANSION IN THE FLURRIES FOR
A FEW HOURS AS THE WAVE TRACKS THROUGH SHOULD BE THE MAIN PROBLEM
FOR THE NIGHT OVER THE REST OF THE CWA. UNFORTUNATELY...ROAD
TEMPERATURES HAVE TRENDED NEAR FREEZING THROUGH THE EVENING...SO
REPORTS OF NUMEROUS ACCIDENTS HAVE COME IN ACROSS THE I-70 AND
SOUTH CORRIDOR AS LIGHT SNOW INITIALLY MELTED THEN REFROZE ON
ROADWAYS. LUCKILY ENOUGH...THIS WAVE IS TRACKING THROUGH RATHER
QUICKLY...AND AFTER ITS PASSAGE...EVEN BOUNDARY LAYER RH VALUES
START TO FALL OFF A BIT...SO IT WOULD SEEM EVEN THE POOR GROWTH
HABIT MAY DETERIORATE BY MORNING. FRIES

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS WILL BE EXPECTED AT ALL TERMINALS OVERNIGHT ALONG WITH
LIGHT SNOW. THINK THAT IFR CIGS WILL OCCUR ACROSS NORTHERN SITES OF
FKL/DUJ...AND AN ISOLATED IFR VIS CANNOT BE RULED OUT IN A HEAVIER
SNOW SHOWER ELSEWHERE. SCATTERED SNOW SHOWERS COULD PERSIST NORTH
AND EAST OF PITTSBURGH AFTER DAYBREAK...BUT COVERAGE WILL BE
MINIMAL. ALTHOUGH MODEL GUIDANCE INDICATES THAT CEILINGS SHOULD BE
SCATTERING OUT FRIDAY AFTERNOON...DO NOT HAVE HIGH CONFIDENCE IN
THIS CONSIDERING WINDS WILL REMAIN OUT OF THE WEST/NORTHWEST...AND
HAVE KEPT TAFS MORE PESSIMISTIC.

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

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 6 AM EST FRIDAY FOR PAZ007>009-
     013>016-022.
WV...NONE.

&&

$$







000
FXUS61 KPBZ 190343
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1043 PM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AN UTTERLY POOR SNOW CRYSTAL GROWTH HABIT EXISTS OVER THE CWA THIS
EVENING...AS EVIDENCED BY THE PINHEAD SIZED SNOWFLAKES/GRAINS THAT
HAVE BEEN SCATTERED ACROSS THE AREA IN THE FORM OF "FLURRIES." IN
ADDITION...AREAS JUST TO THE NORTH AND NORTHWEST OF OUR CWA HAVE
STARTED TO REPORT FREEZING DRIZZLE. THIS SEEMS LIKELY TO CONTINUE
TO FILTER INTO AT LEAST THE NORTHERN REACHES OF THE CWA AS
MOISTURE INCREASES...BUT STILL LITTLE MOISTURE EXISTS ABOVE ABOUT
THE -8C ISOTHERM. AS SUCH...WHILE DEEPER MOISTURE MAY ALLOW SOME
TREND TOWARD SNOW SHOWER ACTIVITY...IT SEEMS INSUFFICIENT TO
PRECLUDE FREEZING DRIZZLE FROM CONTINUING TO DEVELOP IN THE
NORTHERN PORTIONS OF THE CWA.

ADDITIONALLY...WITH AN INCOMING SHORT WAVE TROUGH AND A BIT OF
ELEVATED MOISTURE...SOME SEEDER-FEEDER TYPE OF SNOW FLURRY ACTION
DOES SEEM POSSIBLE FOR A SHORT WINDOW AS THE WAVE TRACKS
THROUGH...HOWEVER MODEL CROSS SECTIONS...TIME HEIGHT
SECTIONS...AND PLAN DEPICTIONS ALL GENERALLY REVEAL A QUICK TREND
TOWARD ZERO MICROBARS/SEC OF LAYER NEGATIVE OMEGA VALUES BETWEEN
00Z AND 06Z THIS EVENING. AS A RESULT...WITH DRY AIR BETWEEN THE
TWO MOIST LAYERS...WEAKENING LIFT ALOFT...AND POOR CRYSTAL GROWTH
BELOW...IT WOULD SEEM JUST A GENERAL EXPANSION IN THE FLURRIES FOR
A FEW HOURS AS THE WAVE TRACKS THROUGH SHOULD BE THE MAIN PROBLEM
FOR THE NIGHT OVER THE REST OF THE CWA. UNFORTUNATELY...ROAD
TEMPERATURES HAVE TRENDED NEAR FREEZING THROUGH THE EVENING...SO
REPORTS OF NUMEROUS ACCIDENTS HAVE COME IN ACROSS THE I-70 AND
SOUTH CORRIDOR AS LIGHT SNOW INITIALLY MELTED THEN REFROZE ON
ROADWAYS. LUCKILY ENOUGH...THIS WAVE IS TRACKING THROUGH RATHER
QUICKLY...AND AFTER ITS PASSAGE...EVEN BOUNDARY LAYER RH VALUES
START TO FALL OFF A BIT...SO IT WOULD SEEM EVEN THE POOR GROWTH
HABIT MAY DETERIORATE BY MORNING. FRIES

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS WILL BE EXPECTED AT ALL TERMINALS OVERNIGHT ALONG WITH
LIGHT SNOW. THINK THAT IFR CIGS WILL OCCUR ACROSS NORTHERN SITES OF
FKL/DUJ...AND AN ISOLATED IFR VIS CANNOT BE RULED OUT IN A HEAVIER
SNOW SHOWER ELSEWHERE. SCATTERED SNOW SHOWERS COULD PERSIST NORTH
AND EAST OF PITTSBURGH AFTER DAYBREAK...BUT COVERAGE WILL BE
MINIMAL. ALTHOUGH MODEL GUIDANCE INDICATES THAT CEILINGS SHOULD BE
SCATTERING OUT FRIDAY AFTERNOON...DO NOT HAVE HIGH CONFIDENCE IN
THIS CONSIDERING WINDS WILL REMAIN OUT OF THE WEST/NORTHWEST...AND
HAVE KEPT TAFS MORE PESSIMISTIC.

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

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 6 AM EST FRIDAY FOR PAZ007>009-
     013>016-022.
WV...NONE.

&&

$$








000
FXUS61 KPBZ 190343
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1043 PM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AN UTTERLY POOR SNOW CRYSTAL GROWTH HABIT EXISTS OVER THE CWA THIS
EVENING...AS EVIDENCED BY THE PINHEAD SIZED SNOWFLAKES/GRAINS THAT
HAVE BEEN SCATTERED ACROSS THE AREA IN THE FORM OF "FLURRIES." IN
ADDITION...AREAS JUST TO THE NORTH AND NORTHWEST OF OUR CWA HAVE
STARTED TO REPORT FREEZING DRIZZLE. THIS SEEMS LIKELY TO CONTINUE
TO FILTER INTO AT LEAST THE NORTHERN REACHES OF THE CWA AS
MOISTURE INCREASES...BUT STILL LITTLE MOISTURE EXISTS ABOVE ABOUT
THE -8C ISOTHERM. AS SUCH...WHILE DEEPER MOISTURE MAY ALLOW SOME
TREND TOWARD SNOW SHOWER ACTIVITY...IT SEEMS INSUFFICIENT TO
PRECLUDE FREEZING DRIZZLE FROM CONTINUING TO DEVELOP IN THE
NORTHERN PORTIONS OF THE CWA.

ADDITIONALLY...WITH AN INCOMING SHORT WAVE TROUGH AND A BIT OF
ELEVATED MOISTURE...SOME SEEDER-FEEDER TYPE OF SNOW FLURRY ACTION
DOES SEEM POSSIBLE FOR A SHORT WINDOW AS THE WAVE TRACKS
THROUGH...HOWEVER MODEL CROSS SECTIONS...TIME HEIGHT
SECTIONS...AND PLAN DEPICTIONS ALL GENERALLY REVEAL A QUICK TREND
TOWARD ZERO MICROBARS/SEC OF LAYER NEGATIVE OMEGA VALUES BETWEEN
00Z AND 06Z THIS EVENING. AS A RESULT...WITH DRY AIR BETWEEN THE
TWO MOIST LAYERS...WEAKENING LIFT ALOFT...AND POOR CRYSTAL GROWTH
BELOW...IT WOULD SEEM JUST A GENERAL EXPANSION IN THE FLURRIES FOR
A FEW HOURS AS THE WAVE TRACKS THROUGH SHOULD BE THE MAIN PROBLEM
FOR THE NIGHT OVER THE REST OF THE CWA. UNFORTUNATELY...ROAD
TEMPERATURES HAVE TRENDED NEAR FREEZING THROUGH THE EVENING...SO
REPORTS OF NUMEROUS ACCIDENTS HAVE COME IN ACROSS THE I-70 AND
SOUTH CORRIDOR AS LIGHT SNOW INITIALLY MELTED THEN REFROZE ON
ROADWAYS. LUCKILY ENOUGH...THIS WAVE IS TRACKING THROUGH RATHER
QUICKLY...AND AFTER ITS PASSAGE...EVEN BOUNDARY LAYER RH VALUES
START TO FALL OFF A BIT...SO IT WOULD SEEM EVEN THE POOR GROWTH
HABIT MAY DETERIORATE BY MORNING. FRIES

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS WILL BE EXPECTED AT ALL TERMINALS OVERNIGHT ALONG WITH
LIGHT SNOW. THINK THAT IFR CIGS WILL OCCUR ACROSS NORTHERN SITES OF
FKL/DUJ...AND AN ISOLATED IFR VIS CANNOT BE RULED OUT IN A HEAVIER
SNOW SHOWER ELSEWHERE. SCATTERED SNOW SHOWERS COULD PERSIST NORTH
AND EAST OF PITTSBURGH AFTER DAYBREAK...BUT COVERAGE WILL BE
MINIMAL. ALTHOUGH MODEL GUIDANCE INDICATES THAT CEILINGS SHOULD BE
SCATTERING OUT FRIDAY AFTERNOON...DO NOT HAVE HIGH CONFIDENCE IN
THIS CONSIDERING WINDS WILL REMAIN OUT OF THE WEST/NORTHWEST...AND
HAVE KEPT TAFS MORE PESSIMISTIC.

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

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 6 AM EST FRIDAY FOR PAZ007>009-
     013>016-022.
WV...NONE.

&&

$$







000
FXUS61 KPBZ 190343
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1043 PM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AN UTTERLY POOR SNOW CRYSTAL GROWTH HABIT EXISTS OVER THE CWA THIS
EVENING...AS EVIDENCED BY THE PINHEAD SIZED SNOWFLAKES/GRAINS THAT
HAVE BEEN SCATTERED ACROSS THE AREA IN THE FORM OF "FLURRIES." IN
ADDITION...AREAS JUST TO THE NORTH AND NORTHWEST OF OUR CWA HAVE
STARTED TO REPORT FREEZING DRIZZLE. THIS SEEMS LIKELY TO CONTINUE
TO FILTER INTO AT LEAST THE NORTHERN REACHES OF THE CWA AS
MOISTURE INCREASES...BUT STILL LITTLE MOISTURE EXISTS ABOVE ABOUT
THE -8C ISOTHERM. AS SUCH...WHILE DEEPER MOISTURE MAY ALLOW SOME
TREND TOWARD SNOW SHOWER ACTIVITY...IT SEEMS INSUFFICIENT TO
PRECLUDE FREEZING DRIZZLE FROM CONTINUING TO DEVELOP IN THE
NORTHERN PORTIONS OF THE CWA.

ADDITIONALLY...WITH AN INCOMING SHORT WAVE TROUGH AND A BIT OF
ELEVATED MOISTURE...SOME SEEDER-FEEDER TYPE OF SNOW FLURRY ACTION
DOES SEEM POSSIBLE FOR A SHORT WINDOW AS THE WAVE TRACKS
THROUGH...HOWEVER MODEL CROSS SECTIONS...TIME HEIGHT
SECTIONS...AND PLAN DEPICTIONS ALL GENERALLY REVEAL A QUICK TREND
TOWARD ZERO MICROBARS/SEC OF LAYER NEGATIVE OMEGA VALUES BETWEEN
00Z AND 06Z THIS EVENING. AS A RESULT...WITH DRY AIR BETWEEN THE
TWO MOIST LAYERS...WEAKENING LIFT ALOFT...AND POOR CRYSTAL GROWTH
BELOW...IT WOULD SEEM JUST A GENERAL EXPANSION IN THE FLURRIES FOR
A FEW HOURS AS THE WAVE TRACKS THROUGH SHOULD BE THE MAIN PROBLEM
FOR THE NIGHT OVER THE REST OF THE CWA. UNFORTUNATELY...ROAD
TEMPERATURES HAVE TRENDED NEAR FREEZING THROUGH THE EVENING...SO
REPORTS OF NUMEROUS ACCIDENTS HAVE COME IN ACROSS THE I-70 AND
SOUTH CORRIDOR AS LIGHT SNOW INITIALLY MELTED THEN REFROZE ON
ROADWAYS. LUCKILY ENOUGH...THIS WAVE IS TRACKING THROUGH RATHER
QUICKLY...AND AFTER ITS PASSAGE...EVEN BOUNDARY LAYER RH VALUES
START TO FALL OFF A BIT...SO IT WOULD SEEM EVEN THE POOR GROWTH
HABIT MAY DETERIORATE BY MORNING. FRIES

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS WILL BE EXPECTED AT ALL TERMINALS OVERNIGHT ALONG WITH
LIGHT SNOW. THINK THAT IFR CIGS WILL OCCUR ACROSS NORTHERN SITES OF
FKL/DUJ...AND AN ISOLATED IFR VIS CANNOT BE RULED OUT IN A HEAVIER
SNOW SHOWER ELSEWHERE. SCATTERED SNOW SHOWERS COULD PERSIST NORTH
AND EAST OF PITTSBURGH AFTER DAYBREAK...BUT COVERAGE WILL BE
MINIMAL. ALTHOUGH MODEL GUIDANCE INDICATES THAT CEILINGS SHOULD BE
SCATTERING OUT FRIDAY AFTERNOON...DO NOT HAVE HIGH CONFIDENCE IN
THIS CONSIDERING WINDS WILL REMAIN OUT OF THE WEST/NORTHWEST...AND
HAVE KEPT TAFS MORE PESSIMISTIC.

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

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 6 AM EST FRIDAY FOR PAZ007>009-
     013>016-022.
WV...NONE.

&&

$$








000
FXUS61 KPBZ 190221
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
921 PM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AN UTTERLY POOR SNOW CRYSTAL GROWTH HABIT EXISTS OVER THE CWA THIS
EVENING...AS EVIDENCED BY THE PINHEAD SIZED SNOWFLAKES/GRAINS THAT
HAVE BEEN SCATTERED ACROSS THE AREA IN THE FORM OF "FLURRIES." IN
ADDITION...AREAS JUST TO THE NORTH AND NORTHWEST OF OUR CWA HAVE
STARTED TO REPORT FREEZING DRIZZLE.  WITH AN INCOMING SHORT WAVE
TROUGH AND A BIT OF ELEVATED MOISTURE...SOME SEEDER-FEEDER TYPE
OF SNOW FLURRY ACTION DOES SEEM POSSIBLE FOR A SHORT WINDOW AS THE
WAVE TRACKS THROUGH...HOWEVER MODEL CROSS SECTIONS...TIME HEIGHT
SECTIONS...AND PLAN DEPICTIONS ALL GENERALLY REVEAL A QUICK TREND
TOWARD ZERO MICROBARS/SEC OF LAYER NEGATIVE OMEGA VALUES BETWEEN
00Z AND 06Z THIS EVENING. AS A RESULT...WITH DRY AIR BETWEEN THE
TWO MOIST LAYERS...WEAKENING LIFT ALOFT...AND POOR CRYSTAL GROWTH
BELOW...IT WOULD SEEM JUST A GENERAL EXPANSION IN THE FLURRIES FOR
A FEW HOURS AS THE WAVE TRACKS THROUGH SHOULD BE THE MAIN PROBLEM
FOR THE NIGHT. AFTER ITS PASSAGE...EVEN BOUNDARY LAYER RH VALUES
START TO FALL OFF A BIT...SO IT WOULD SEEM EVEN THE POOR GROWTH
HABIT MAY DETERIORATE BY MORNING. AS SUCH...REALLY NOTHING MORE
THAN A DUSTING IS EXPECTED ACROSS THE CWA AS THIS WEAK SYSTEM
PASSES THIS EVENING AND EARLY TONIGHT. FRIES

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS WILL BE EXPECTED AT ALL TERMINALS OVERNIGHT ALONG WITH
LIGHT SNOW. THINK THAT IFR CIGS WILL OCCUR ACROSS NORTHERN SITES OF
FKL/DUJ...AND AN ISOLATED IFR VIS CANNOT BE RULED OUT IN A HEAVIER
SNOW SHOWER ELSEWHERE. SCATTERED SNOW SHOWERS COULD PERSIST NORTH
AND EAST OF PITTSBURGH AFTER DAYBREAK...BUT COVERAGE WILL BE
MINIMAL. ALTHOUGH MODEL GUIDANCE INDICATES THAT CEILINGS SHOULD BE
SCATTERING OUT FRIDAY AFTERNOON...DO NOT HAVE HIGH CONFIDENCE IN
THIS CONSIDERING WINDS WILL REMAIN OUT OF THE WEST/NORTHWEST...AND
HAVE KEPT TAFS MORE PESSIMISTIC.

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

&&

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

&&

$$








000
FXUS61 KPBZ 190221
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
921 PM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AN UTTERLY POOR SNOW CRYSTAL GROWTH HABIT EXISTS OVER THE CWA THIS
EVENING...AS EVIDENCED BY THE PINHEAD SIZED SNOWFLAKES/GRAINS THAT
HAVE BEEN SCATTERED ACROSS THE AREA IN THE FORM OF "FLURRIES." IN
ADDITION...AREAS JUST TO THE NORTH AND NORTHWEST OF OUR CWA HAVE
STARTED TO REPORT FREEZING DRIZZLE.  WITH AN INCOMING SHORT WAVE
TROUGH AND A BIT OF ELEVATED MOISTURE...SOME SEEDER-FEEDER TYPE
OF SNOW FLURRY ACTION DOES SEEM POSSIBLE FOR A SHORT WINDOW AS THE
WAVE TRACKS THROUGH...HOWEVER MODEL CROSS SECTIONS...TIME HEIGHT
SECTIONS...AND PLAN DEPICTIONS ALL GENERALLY REVEAL A QUICK TREND
TOWARD ZERO MICROBARS/SEC OF LAYER NEGATIVE OMEGA VALUES BETWEEN
00Z AND 06Z THIS EVENING. AS A RESULT...WITH DRY AIR BETWEEN THE
TWO MOIST LAYERS...WEAKENING LIFT ALOFT...AND POOR CRYSTAL GROWTH
BELOW...IT WOULD SEEM JUST A GENERAL EXPANSION IN THE FLURRIES FOR
A FEW HOURS AS THE WAVE TRACKS THROUGH SHOULD BE THE MAIN PROBLEM
FOR THE NIGHT. AFTER ITS PASSAGE...EVEN BOUNDARY LAYER RH VALUES
START TO FALL OFF A BIT...SO IT WOULD SEEM EVEN THE POOR GROWTH
HABIT MAY DETERIORATE BY MORNING. AS SUCH...REALLY NOTHING MORE
THAN A DUSTING IS EXPECTED ACROSS THE CWA AS THIS WEAK SYSTEM
PASSES THIS EVENING AND EARLY TONIGHT. FRIES

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS WILL BE EXPECTED AT ALL TERMINALS OVERNIGHT ALONG WITH
LIGHT SNOW. THINK THAT IFR CIGS WILL OCCUR ACROSS NORTHERN SITES OF
FKL/DUJ...AND AN ISOLATED IFR VIS CANNOT BE RULED OUT IN A HEAVIER
SNOW SHOWER ELSEWHERE. SCATTERED SNOW SHOWERS COULD PERSIST NORTH
AND EAST OF PITTSBURGH AFTER DAYBREAK...BUT COVERAGE WILL BE
MINIMAL. ALTHOUGH MODEL GUIDANCE INDICATES THAT CEILINGS SHOULD BE
SCATTERING OUT FRIDAY AFTERNOON...DO NOT HAVE HIGH CONFIDENCE IN
THIS CONSIDERING WINDS WILL REMAIN OUT OF THE WEST/NORTHWEST...AND
HAVE KEPT TAFS MORE PESSIMISTIC.

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

&&

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

&&

$$







000
FXUS61 KPBZ 182333
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
633 PM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AN UTTERLY POOR SNOW CRYSTAL GROWTH HABIT EXISTS OVER THE CWA THIS
EVENING...AS EVIDENCED BY THE PINHEAD SIZED SNOWFLAKES/GRAINS THAT
HAVE BEEN SCATTERED ACROSS THE AREA IN THE FORM OF "FLURRIES."
WITH AN INCOMING SHORT WAVE TROUGH AND A BIT OF ELEVATED
MOISTURE...SOME SEEDER-FEEDER TYPE OF SNOW FLURRY ACTION DOES SEEM
POSSIBLE FOR A SHORT WINDOW AS THE WAVE TRACKS THROUGH...HOWEVER
MODEL CROSS SECTIONS...TIME HEIGHT SECTIONS...AND PLAN DEPICTIONS
ALL GENERALLY REVEAL A QUICK TREND TOWARD ZERO MICROBARS/SEC OF
LAYER NEGATIVE OMEGA VALUES BETWEEN 00Z AND 06Z THIS EVENING. AS
A RESULT...WITH DRY AIR BETWEEN THE TWO MOIST LAYERS...WEAKENING
LIFT ALOFT...AND POOR CRYSTAL GROWTH BELOW...IT WOULD SEEM JUST A
GENERAL EXPANSION IN THE FLURRIES FOR A FEW HOURS AS THE WAVE
TRACKS THROUGH SHOULD BE THE MAIN PROBLEM FOR THE NIGHT. AFTER ITS
PASSAGE...EVEN BOUNDARY LAYER RH VALUES START TO FALL OFF A
BIT...SO IT WOULD SEEM EVEN THE POOR GROWTH HABIT MAY DETERIORATE
BY MORNING. AS SUCH...REALLY NOTHING MORE THAN A DUSTING IS
EXPECTED ACROSS THE CWA AS THIS WEAK SYSTEM PASSES THIS EVENING
AND EARLY TONIGHT. FRIES

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS WILL BE EXPECTED AT ALL TERMINALS OVERNIGHT ALONG WITH
LIGHT SNOW. THINK THAT IFR CIGS WILL OCCUR ACROSS NORTHERN SITES OF
FKL/DUJ...AND AN ISOLATED IFR VIS CANNOT BE RULED OUT IN A HEAVIER
SNOW SHOWER ELSEWHERE. SCATTERED SNOW SHOWERS COULD PERSIST NORTH
AND EAST OF PITTSBURGH AFTER DAYBREAK...BUT COVERAGE WILL BE
MINIMAL. ALTHOUGH MODEL GUIDANCE INDICATES THAT CEILINGS SHOULD BE
SCATTERING OUT FRIDAY AFTERNOON...DO NOT HAVE HIGH CONFIDENCE IN
THIS CONSIDERING WINDS WILL REMAIN OUT OF THE WEST/NORTHWEST...AND
HAVE KEPT TAFS MORE PESSIMISTIC.

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

&&

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

&&

$$








000
FXUS61 KPBZ 182333
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
633 PM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AN UTTERLY POOR SNOW CRYSTAL GROWTH HABIT EXISTS OVER THE CWA THIS
EVENING...AS EVIDENCED BY THE PINHEAD SIZED SNOWFLAKES/GRAINS THAT
HAVE BEEN SCATTERED ACROSS THE AREA IN THE FORM OF "FLURRIES."
WITH AN INCOMING SHORT WAVE TROUGH AND A BIT OF ELEVATED
MOISTURE...SOME SEEDER-FEEDER TYPE OF SNOW FLURRY ACTION DOES SEEM
POSSIBLE FOR A SHORT WINDOW AS THE WAVE TRACKS THROUGH...HOWEVER
MODEL CROSS SECTIONS...TIME HEIGHT SECTIONS...AND PLAN DEPICTIONS
ALL GENERALLY REVEAL A QUICK TREND TOWARD ZERO MICROBARS/SEC OF
LAYER NEGATIVE OMEGA VALUES BETWEEN 00Z AND 06Z THIS EVENING. AS
A RESULT...WITH DRY AIR BETWEEN THE TWO MOIST LAYERS...WEAKENING
LIFT ALOFT...AND POOR CRYSTAL GROWTH BELOW...IT WOULD SEEM JUST A
GENERAL EXPANSION IN THE FLURRIES FOR A FEW HOURS AS THE WAVE
TRACKS THROUGH SHOULD BE THE MAIN PROBLEM FOR THE NIGHT. AFTER ITS
PASSAGE...EVEN BOUNDARY LAYER RH VALUES START TO FALL OFF A
BIT...SO IT WOULD SEEM EVEN THE POOR GROWTH HABIT MAY DETERIORATE
BY MORNING. AS SUCH...REALLY NOTHING MORE THAN A DUSTING IS
EXPECTED ACROSS THE CWA AS THIS WEAK SYSTEM PASSES THIS EVENING
AND EARLY TONIGHT. FRIES

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
MVFR CIGS WILL BE EXPECTED AT ALL TERMINALS OVERNIGHT ALONG WITH
LIGHT SNOW. THINK THAT IFR CIGS WILL OCCUR ACROSS NORTHERN SITES OF
FKL/DUJ...AND AN ISOLATED IFR VIS CANNOT BE RULED OUT IN A HEAVIER
SNOW SHOWER ELSEWHERE. SCATTERED SNOW SHOWERS COULD PERSIST NORTH
AND EAST OF PITTSBURGH AFTER DAYBREAK...BUT COVERAGE WILL BE
MINIMAL. ALTHOUGH MODEL GUIDANCE INDICATES THAT CEILINGS SHOULD BE
SCATTERING OUT FRIDAY AFTERNOON...DO NOT HAVE HIGH CONFIDENCE IN
THIS CONSIDERING WINDS WILL REMAIN OUT OF THE WEST/NORTHWEST...AND
HAVE KEPT TAFS MORE PESSIMISTIC.

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

&&

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

&&

$$







000
FXUS61 KPBZ 182306
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
606 PM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AN UTTERLY POOR SNOW CRYSTAL GROWTH HABIT EXISTS OVER THE CWA THIS
EVENING...AS EVIDENCED BY THE PINHEAD SIZED SNOWFLAKES/GRAINS THAT
HAVE BEEN SCATTERED ACROSS THE AREA IN THE FORM OF "FLURRIES."
WITH AN INCOMING SHORT WAVE TROUGH AND A BIT OF ELEVATED
MOISTURE...SOME SEEDER-FEEDER TYPE OF SNOW FLURRY ACTION DOES SEEM
POSSIBLE FOR A SHORT WINDOW AS THE WAVE TRACKS THROUGH...HOWEVER
MODEL CROSS SECTIONS...TIME HEIGHT SECTIONS...AND PLAN DEPICTIONS
ALL GENERALLY REVEAL A QUICK TREND TOWARD ZERO MICROBARS/SEC OF
LAYER NEGATIVE OMEGA VALUES BETWEEN 00Z AND 006Z THIS EVENING. AS
A RESULT...WITH DRY AIR BETWEEN THE TWO MOIST LAYERS...WEAKENING
LIFT ALOFT...AND POOR CRYSTAL GROWTH BELOW...IT WOULD SEEM JUST A
GENERAL EXPANSION IN THE FLURRIES FOR A FEW HOURS AS THE WAVE
TRACKS THROUGH SHOULD BE THE MAIN PROBLEM FOR THE NIGHT. AFTER ITS
PASSAGE...EVEN BOUNDARY LAYER RH VALUES START TO FALL OFF A
BIT...SO IT WOULD SEEM EVEN THE POOR GROWTH HABIT MAY DETERIORATE
BY MORNING. AS SUCH...REALLY NOTHING MORE THAN A DUSTING IS
EXPECTED ACROSS THE CWA AS THIS WEAK SYSTEM PASSES THIS EVENING
AND EARLY TONIGHT. FRIES

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
MVFR CIGS INTO EARLY EVENING WITH AREAS OF IFR FOG AND LIGHT SNOW
AT TIMES. OVERNIGHT A WEAK SHORTWAVE WILL BRING MVFR IN LIGHT
SNOW. IFR CIGS POSSIBLE OVERNIGHT WITH THIS SYSTEM BUT LOOKS TO BE
BORDERLINE. LIGHT SNOW ENDS BEFORE DAYBREAK WITH CONTINUED MVFR
CIGS THROUGH FRIDAY.

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

&&

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

&&

$$








000
FXUS61 KPBZ 181942
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
242 PM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LLVL MSTR BLO A TEMP INVERSION WL CONT TO PRODUCE SOME FLURRIES
INTO THE EVE. A WK SHRTWV ADVNG ACRS THE MIDWEST WL CROSS THE RGN
THIS EVE AS WELL. AS MSTR INCRS WITH THE WAVE EXP A PD OF LGT SNW
OR FLURRIES ACRS MUCH OF THE RGN...THOUGH LTL IF ANY ACCUMS ARE
EXPD. SOME LK AND TERRAIN ENHANCEMENT N OF I 80 AND IN THE RIDGES
COULD SQUEEZE OUT SOME SML ACCUMS LESS THAN AN INCH...WITH MSTR
DEPTH AND THE CAPPING TEMP INVERSION LMTG THE SNW POTENTIAL. LOW
TEMPS SHOULD AVG A LTL ABV SEASONAL LVLS.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
MVFR CIGS INTO EARLY EVENING WITH AREAS OF IFR FOG AND LIGHT SNOW
AT TIMES. OVERNIGHT A WEAK SHORTWAVE WILL BRING MVFR IN LIGHT
SNOW. IFR CIGS POSSIBLE OVERNIGHT WITH THIS SYSTEM BUT LOOKS TO BE
BORDERLINE. LIGHT SNOW ENDS BEFORE DAYBREAK WITH CONTINUED MVFR
CIGS THROUGH FRIDAY.

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

&&

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

&&

$$

07/10






000
FXUS61 KPBZ 181942
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
242 PM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION TONIGHT. BUILDING HIGH
PRESSURE IS EXPECTED THROUGH THE WEEKEND...THOUGH CLOUDS WILL
REMAIN.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LLVL MSTR BLO A TEMP INVERSION WL CONT TO PRODUCE SOME FLURRIES
INTO THE EVE. A WK SHRTWV ADVNG ACRS THE MIDWEST WL CROSS THE RGN
THIS EVE AS WELL. AS MSTR INCRS WITH THE WAVE EXP A PD OF LGT SNW
OR FLURRIES ACRS MUCH OF THE RGN...THOUGH LTL IF ANY ACCUMS ARE
EXPD. SOME LK AND TERRAIN ENHANCEMENT N OF I 80 AND IN THE RIDGES
COULD SQUEEZE OUT SOME SML ACCUMS LESS THAN AN INCH...WITH MSTR
DEPTH AND THE CAPPING TEMP INVERSION LMTG THE SNW POTENTIAL. LOW
TEMPS SHOULD AVG A LTL ABV SEASONAL LVLS.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
SFC HIGH PRES IS PROGGED TO BLD IN UNDER UPR TROFG OVR THE GT LKS
FRI...ENDING ANY LINGERING MRNG SNW SHWRS. THE SFC HIGH IS EXPD TO
BRING DRY WEA THRU THE WKEND...THOUGH PERSISTENT MSTR BLO AN
INVERSION MAY KEEP SKIES MCLDY. A SHRTWV MOVG ACRS THE SERN CONUS
LT SAT/SAT NGT IS NOW PROGGED TO STAY FAR ENOUGH S TO REMOVE ALL
PCPN FM THE FCST FOR AREAS S OF PIT. A WK SHRTWV IS PROGGED FOR
ERLY SUN ACRS THE GT LKS...BUT WITH A LACK OF DEEP MSTR AND THE
SFC HIGH OVERHEAD KEPT THE FCST DRY.

SLGTLY BLO AVG TEMPS SHOULD RTN TO NR SEASONAL LVLS BY SUN.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
MVFR CIGS INTO EARLY EVENING WITH AREAS OF IFR FOG AND LIGHT SNOW
AT TIMES. OVERNIGHT A WEAK SHORTWAVE WILL BRING MVFR IN LIGHT
SNOW. IFR CIGS POSSIBLE OVERNIGHT WITH THIS SYSTEM BUT LOOKS TO BE
BORDERLINE. LIGHT SNOW ENDS BEFORE DAYBREAK WITH CONTINUED MVFR
CIGS THROUGH FRIDAY.

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

&&

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

&&

$$

07/10







000
FXUS61 KPBZ 181834
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
134 PM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION THIS EVENING...FOLLOWED
BY BUILDING HIGH PRESSURE FRIDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLDS WL CONT TDA WITH MRNG RAOBS SHOWING LLVL MSTR TRAPPED BLO A
TEMP INVERSION. FLURRIES OR LGT SNW SHWRS ARE EXPD ALSO...BUT WITH
THE SHALLOW MSTR LYR NO SGFNT ACCUMS ARE EXPD. TEMPS SHOULD AVG A
FEW DEG BLO THE SEASONAL AVG.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
A WK SHRTWV IS PROGGED TO ADVN ACRS THE RGN TNGT. WITH THE CONTD
LLVL MSTR AND TEMP INVERSION JUST SCT FLURRIES ARE EXPD...THOUGH A
FEW LGT ACCUMULATING SNW SHWRS ARE PSBL WITH SOME LTD LK AND
TERRAIN ENHANCEMENT N OF I 80 AND IN THE RIDGES. BLDG HIGH PRES
SHOULD END ANY RMNG SNW SHWRS AND FLURRIES FRI MRNG...THOUGH
INVERSION TRAPPED LLVL MSTR SHOULD KEEP CLDS ACRS THE RGN.

A SHRTWV ACRS THE SERN CONUS IS PROGGED TO BRING LOW CHCS FOR LGT
SNW WELL SE OF PIT LT SAT...THOUGH MDLS CONT TO TREND FURTHER S
WITH PCPN FM THIS SYSTEM. TEMPS SHOULD AVG A LTL BLO THE SEASONAL
AVGS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
WHILE THE MODELS AGREE ON A DEEPENING UPPER LEVEL TROUGH TO CLOSE
OFF OVER THE GREAT LAKES THROUGH THE PERIOD THE DETAILS OF HOW
THIS EXACTLY UNFOLDS WILL BE CRITICAL. BY MONDAY SOUTHERN STREAM
SHORTWAVE AHEAD OF MAIN NORTHERN STREAM UPPER TROUGH DIGGING INTO
THE NORTHERN PLAINS WILL PRODUCE LOW PRESSURE ACROSS THE CAROLINAS
MOVING OFF SHORE OF THE EAST COAST. THE SOUTHEAST RIDGES MAY BE
BRUSHED BY LIGHT RAIN FROM THIS SYSTEM. NEXT UP IS DEEPENING LOW
PRESSURE OVER THE OHIO VALLEY AHEAD OF SHARPLY DIGGING UPPER
TROUGH AND CLOSED LOW MOVING INTO THE WESTERN GREAT LAKES. UPPER
OHIO VALLEY LOOKS TO BE ON THE WARM SIDE OF THE SYSTEM TUESDAY
INTO WEDNESDAY WITH RAIN...FOLLOWED BY STRONG COLD FRONT AND COLD
ADVECTION LATER WEDNESDAY NIGHT AND THURSDAY WITH SNOW SHOWERS.
WITH SUCH A STRONG SYSTEM ALOFT AND FAST DEEPENING LOW PRESSURE AT
THE SURFACE TIMING OF COLD AIR AND EXACT TRACK WILL LIKELY CHANGE
AS WE GET CLOSER TO CHRISTMAS. ALL IN ALL PREVIOUS FORECAST IS
LITTLE CHANGED WITH ONLY MINOR ADJUSTMENTS BASED ON NEWEST WPC
EXTENDED PROGS.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
MVFR CIGS INTO EARLY EVENING WITH AREAS OF IFR FOG AND LIGHT SNOW
AT TIMES. OVERNIGHT A WEAK SHORTWAVE WILL BRING MVFR IN LIGHT
SNOW. IFR CIGS POSSIBLE OVERNIGHT WITH THIS SYSTEM BUT LOOKS TO BE
BORDERLINE. LIGHT SNOW ENDS BEFORE DAYBREAK WITH CONTINUED MVFR
CIGS THROUGH FRIDAY.

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

&&

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

&&

$$









000
FXUS61 KPBZ 181617
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1117 AM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION THIS EVENING...FOLLOWED
BY BUILDING HIGH PRESSURE FRIDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLDS WL CONT TDA WITH MRNG RAOBS SHOWING LLVL MSTR TRAPPED BLO A
TEMP INVERSION. FLURRIES OR LGT SNW SHWRS ARE EXPD ALSO...BUT WITH
THE SHALLOW MSTR LYR NO SGFNT ACCUMS ARE EXPD. TEMPS SHOULD AVG A
FEW DEG BLO THE SEASONAL AVG.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A WK SHRTWV IS PROGGED TO ADVN ACRS THE RGN TNGT. WITH THE CONTD
LLVL MSTR AND TEMP INVERSION JUST SCT FLURRIES ARE EXPD...THOUGH A
FEW LGT ACCUMULATING SNW SHWRS ARE PSBL WITH SOME LTD LK AND
TERRAIN ENHANCEMENT N OF I 80 AND IN THE RIDGES. BLDG HIGH PRES
SHOULD END ANY RMNG SNW SHWRS AND FLURRIES FRI MRNG...THOUGH
INVERSION TRAPPED LLVL MSTR SHOULD KEEP CLDS ACRS THE RGN.

A SHRTWV ACRS THE SERN CONUS IS PROGGED TO BRING LOW CHCS FOR LGT
SNW WELL SE OF PIT LT SAT...THOUGH MDLS CONT TO TREND FURTHER S
WITH PCPN FM THIS SYSTEM. TEMPS SHOULD AVG A LTL BLO THE SEASONAL
AVGS.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE LONGWAVE PATTERN WILL BECOME MORE MERIDIONAL SUNDAY THROUGH
THE FIRST HALF OF NEXT WEEK AS A TROUGH OF LOW PRESSURE DIGS SOUTH
OVER THE CENTRAL US AND DEEPENS AS IT TRANSITIONS EASTWARD. LATEST
GUIDANCE SHOWS GOOD CONTINUITY WITH THIS FEATURE AND OVERALL ARE
IN FAIRLY GOOD AGREEMENT. WITH THAT AND LATEST RMOP AND MODTRENDS
VERY SIMILAR TO 24HRS AGO...OPTED TO ADJUST THE EXTENDED TO BE MORE IN
LINE WITH A BLEND OF THE 00Z WPC...EC...AND GEFS....WHICH
RESULTED IN A FAIRLY BIG INCREASE IN BOTH LOW AND MAX
TEMPERATURES TOWARDS THE MIDDLE OF THE WEEK WITH HIGHER CONFIDENCE
IN TIMING. CURRENTLY...THE BRUNT OF PRECIPITATION LOOKS TO FALL
OVERNIGHT TUESDAY THROUGH WEDNESDAY MORNING AS RAIN AHEAD OF THE
COLD FRONT UNDER STRONG WAA AND MOISTURE ADVECTION...WITH LATEST
ENSEMBLE GUIDANCE INDICATING V-COMPONENT ANOMALIES BY TUESDAY
AFTERNOON AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL. TEMPERATURES
ARE FORECAST TO BE AROUND 10 DEGREES ABOVE NORMAL BY TUESDAY
AFTERNOON...AND STAYING RELATIVELY WARM TUESDAY NIGHT AS STRONGER
SOUTHWEST SURFACE WINDS AHEAD OF THE SYSTEM KEEPS STRONG WAA IN
PLAY AND THE LOWER LEVELS MIXED. WHILE THE FINER DETAILS
CERTAINLY COULD CHANGE...LATEST MODEL PROGS SHOW COLD AIR BEHIND
THE FRONT FULLY INTO THE FORECAST AREA BY CHRISTMAS MORNING AT
WHICH TIME ALL PRECIPITATION WOULD CHANGEOVER TO SNOW. CHANGEOVER
SHOULD HAPPEN RELATIVELY QUICKLY...BUT THERE IS SOME UNCERTAINTY
ON HOW LONG WE MAY SEE MIXED PRECIPITATION BASED ON LATEST PROGGED
CRITICAL THICKNESSES. IN GENERAL...CURRENTLY AROUND ONE HALF INCH
OF LIQUID PRECIPITATION IS EXPECTED AT THIS TIME AHEAD OF THE COLD
FRONT WITH LIGHT SNOWFALL ON THE BACKSIDE. NOMADS REANALYSIS BASED
ON THE LATEST 00Z RUN GIVES AROUND A 50 PERCENT CHANCE OF AN INCH
OR SO OF SNOW FALLING ON THE BACKSIDE OF THE FRONT THE NIGHT OF
THE 24TH AND INTO THE 25TH.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
A PERSISTENT LOW LEVEL DECK OF STRATOCUMULUS WILL KEEP SITES
MAINLY MVFR THROUGH THE DAY...WITH TIMES OF IFR IN LIGHT SNOW AND
FOG. WEAK SHORTWAVE CROSSING REGION TONIGHT WILL BRING MVFR LIGHT
SNOW AND NEAR IFR CIGS.

OUTLOOK.../FRIDAY THROUGH MONDAY/...
STRATUS MAY PERSIST INTO THE WEEKEND.

&&

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

&&

$$







000
FXUS61 KPBZ 181604
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1104 AM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION THIS EVENING...FOLLOWED
BY BUILDING HIGH PRESSURE FRIDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLDS WL CONT TDA WITH MRNG RAOBS SHOWING LLVL MSTR TRAPPED BLO A
TEMP INVERSION. A FEW FLURRIES OR LGT SNW SHWRS ARE PSBL...BUT
WITH THE SHALLOW MSTR LYR NOTHING SGFNT IS EXPD. TEMPS SHOULD AVG
A FEW DEG BLO THE SEASONAL AVG.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A WK SHRTWV IS PROGGED TO ADVN ACRS THE RGN TNGT. WITH THE CONTD
LLVL MSTR AND TEMP INVERSION JUST SCT FLURRIES ARE EXPD...THOUGH A
FEW LGT ACCUMULATING SNW SHWRS ARE PSBL WITH SOME LTD LK AND
TERRAIN ENHANCEMENT N OF I 80 AND IN THE RIDGES. BLDG HIGH PRES
SHOULD END ANY RMNG SNW SHWRS AND FLURRIES FRI MRNG...THOUGH
INVERSION TRAPPED LLVL MSTR SHOULD KEEP CLDS ACRS THE RGN.

A SHRTWV ACRS THE SERN CONUS IS PROGGED TO BRING LOW CHCS FOR LGT
SNW WELL SE OF PIT LT SAT...THOUGH MDLS CONT TO TREND FURTHER S
WITH PCPN FM THIS SYSTEM. TEMPS SHOULD AVG A LTL BLO THE SEASONAL
AVGS.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE LONGWAVE PATTERN WILL BECOME MORE MERIDIONAL SUNDAY THROUGH
THE FIRST HALF OF NEXT WEEK AS A TROUGH OF LOW PRESSURE DIGS SOUTH
OVER THE CENTRAL US AND DEEPENS AS IT TRANSITIONS EASTWARD. LATEST
GUIDANCE SHOWS GOOD CONTINUITY WITH THIS FEATURE AND OVERALL ARE
IN FAIRLY GOOD AGREEMENT. WITH THAT AND LATEST RMOP AND MODTRENDS
VERY SIMILAR TO 24HRS AGO...OPTED TO ADJUST THE EXTENDED TO BE MORE IN
LINE WITH A BLEND OF THE 00Z WPC...EC...AND GEFS....WHICH
RESULTED IN A FAIRLY BIG INCREASE IN BOTH LOW AND MAX
TEMPERATURES TOWARDS THE MIDDLE OF THE WEEK WITH HIGHER CONFIDENCE
IN TIMING. CURRENTLY...THE BRUNT OF PRECIPITATION LOOKS TO FALL
OVERNIGHT TUESDAY THROUGH WEDNESDAY MORNING AS RAIN AHEAD OF THE
COLD FRONT UNDER STRONG WAA AND MOISTURE ADVECTION...WITH LATEST
ENSEMBLE GUIDANCE INDICATING V-COMPONENT ANOMALIES BY TUESDAY
AFTERNOON AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL. TEMPERATURES
ARE FORECAST TO BE AROUND 10 DEGREES ABOVE NORMAL BY TUESDAY
AFTERNOON...AND STAYING RELATIVELY WARM TUESDAY NIGHT AS STRONGER
SOUTHWEST SURFACE WINDS AHEAD OF THE SYSTEM KEEPS STRONG WAA IN
PLAY AND THE LOWER LEVELS MIXED. WHILE THE FINER DETAILS
CERTAINLY COULD CHANGE...LATEST MODEL PROGS SHOW COLD AIR BEHIND
THE FRONT FULLY INTO THE FORECAST AREA BY CHRISTMAS MORNING AT
WHICH TIME ALL PRECIPITATION WOULD CHANGEOVER TO SNOW. CHANGEOVER
SHOULD HAPPEN RELATIVELY QUICKLY...BUT THERE IS SOME UNCERTAINTY
ON HOW LONG WE MAY SEE MIXED PRECIPITATION BASED ON LATEST PROGGED
CRITICAL THICKNESSES. IN GENERAL...CURRENTLY AROUND ONE HALF INCH
OF LIQUID PRECIPITATION IS EXPECTED AT THIS TIME AHEAD OF THE COLD
FRONT WITH LIGHT SNOWFALL ON THE BACKSIDE. NOMADS REANALYSIS BASED
ON THE LATEST 00Z RUN GIVES AROUND A 50 PERCENT CHANCE OF AN INCH
OR SO OF SNOW FALLING ON THE BACKSIDE OF THE FRONT THE NIGHT OF
THE 24TH AND INTO THE 25TH.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
A PERSISTENT LOW LEVEL DECK OF STRATOCUMULUS WILL KEEP SITES
MAINLY MVFR THROUGH THE DAY...WITH TIMES OF IFR IN LIGHT SNOW AND
FOG. WEAK SHORTWAVE CROSSING REGION TONIGHT WILL BRING MVFR LIGHT
SNOW AND NEAR IFR CIGS.

OUTLOOK.../FRIDAY THROUGH MONDAY/...
STRATUS MAY PERSIST INTO THE WEEKEND.

&&

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

&&

$$









000
FXUS61 KPBZ 181604
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1104 AM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION THIS EVENING...FOLLOWED
BY BUILDING HIGH PRESSURE FRIDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLDS WL CONT TDA WITH MRNG RAOBS SHOWING LLVL MSTR TRAPPED BLO A
TEMP INVERSION. A FEW FLURRIES OR LGT SNW SHWRS ARE PSBL...BUT
WITH THE SHALLOW MSTR LYR NOTHING SGFNT IS EXPD. TEMPS SHOULD AVG
A FEW DEG BLO THE SEASONAL AVG.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A WK SHRTWV IS PROGGED TO ADVN ACRS THE RGN TNGT. WITH THE CONTD
LLVL MSTR AND TEMP INVERSION JUST SCT FLURRIES ARE EXPD...THOUGH A
FEW LGT ACCUMULATING SNW SHWRS ARE PSBL WITH SOME LTD LK AND
TERRAIN ENHANCEMENT N OF I 80 AND IN THE RIDGES. BLDG HIGH PRES
SHOULD END ANY RMNG SNW SHWRS AND FLURRIES FRI MRNG...THOUGH
INVERSION TRAPPED LLVL MSTR SHOULD KEEP CLDS ACRS THE RGN.

A SHRTWV ACRS THE SERN CONUS IS PROGGED TO BRING LOW CHCS FOR LGT
SNW WELL SE OF PIT LT SAT...THOUGH MDLS CONT TO TREND FURTHER S
WITH PCPN FM THIS SYSTEM. TEMPS SHOULD AVG A LTL BLO THE SEASONAL
AVGS.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE LONGWAVE PATTERN WILL BECOME MORE MERIDIONAL SUNDAY THROUGH
THE FIRST HALF OF NEXT WEEK AS A TROUGH OF LOW PRESSURE DIGS SOUTH
OVER THE CENTRAL US AND DEEPENS AS IT TRANSITIONS EASTWARD. LATEST
GUIDANCE SHOWS GOOD CONTINUITY WITH THIS FEATURE AND OVERALL ARE
IN FAIRLY GOOD AGREEMENT. WITH THAT AND LATEST RMOP AND MODTRENDS
VERY SIMILAR TO 24HRS AGO...OPTED TO ADJUST THE EXTENDED TO BE MORE IN
LINE WITH A BLEND OF THE 00Z WPC...EC...AND GEFS....WHICH
RESULTED IN A FAIRLY BIG INCREASE IN BOTH LOW AND MAX
TEMPERATURES TOWARDS THE MIDDLE OF THE WEEK WITH HIGHER CONFIDENCE
IN TIMING. CURRENTLY...THE BRUNT OF PRECIPITATION LOOKS TO FALL
OVERNIGHT TUESDAY THROUGH WEDNESDAY MORNING AS RAIN AHEAD OF THE
COLD FRONT UNDER STRONG WAA AND MOISTURE ADVECTION...WITH LATEST
ENSEMBLE GUIDANCE INDICATING V-COMPONENT ANOMALIES BY TUESDAY
AFTERNOON AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL. TEMPERATURES
ARE FORECAST TO BE AROUND 10 DEGREES ABOVE NORMAL BY TUESDAY
AFTERNOON...AND STAYING RELATIVELY WARM TUESDAY NIGHT AS STRONGER
SOUTHWEST SURFACE WINDS AHEAD OF THE SYSTEM KEEPS STRONG WAA IN
PLAY AND THE LOWER LEVELS MIXED. WHILE THE FINER DETAILS
CERTAINLY COULD CHANGE...LATEST MODEL PROGS SHOW COLD AIR BEHIND
THE FRONT FULLY INTO THE FORECAST AREA BY CHRISTMAS MORNING AT
WHICH TIME ALL PRECIPITATION WOULD CHANGEOVER TO SNOW. CHANGEOVER
SHOULD HAPPEN RELATIVELY QUICKLY...BUT THERE IS SOME UNCERTAINTY
ON HOW LONG WE MAY SEE MIXED PRECIPITATION BASED ON LATEST PROGGED
CRITICAL THICKNESSES. IN GENERAL...CURRENTLY AROUND ONE HALF INCH
OF LIQUID PRECIPITATION IS EXPECTED AT THIS TIME AHEAD OF THE COLD
FRONT WITH LIGHT SNOWFALL ON THE BACKSIDE. NOMADS REANALYSIS BASED
ON THE LATEST 00Z RUN GIVES AROUND A 50 PERCENT CHANCE OF AN INCH
OR SO OF SNOW FALLING ON THE BACKSIDE OF THE FRONT THE NIGHT OF
THE 24TH AND INTO THE 25TH.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
A PERSISTENT LOW LEVEL DECK OF STRATOCUMULUS WILL KEEP SITES
MAINLY MVFR THROUGH THE DAY...WITH TIMES OF IFR IN LIGHT SNOW AND
FOG. WEAK SHORTWAVE CROSSING REGION TONIGHT WILL BRING MVFR LIGHT
SNOW AND NEAR IFR CIGS.

OUTLOOK.../FRIDAY THROUGH MONDAY/...
STRATUS MAY PERSIST INTO THE WEEKEND.

&&

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

&&

$$










000
FXUS61 KPBZ 181422
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
922 AM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION THIS EVENING...FOLLOWED
BY BUILDING HIGH PRESSURE FRIDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLDS WL CONT TDA WITH MRNG RAOBS SHOWING LLVL MSTR TRAPPED BLO A
TEMP INVERSION. A FEW FLURRIES OR LGT SNW SHWRS ARE PSBL...BUT
WITH THE SHALLOW MSTR LYR NOTHING SGFNT IS EXPD. TEMPS SHOULD AVG
A FEW DEG BLO THE SEASONAL AVG.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A WK SHRTWV IS PROGGED TO ADVN ACRS THE RGN TNGT. WITH THE CONTD
LLVL MSTR AND TEMP INVERSION JUST SCT FLURRIES ARE EXPD...THOUGH A
FEW LGT ACCUMULATING SNW SHWRS ARE PSBL WITH SOME LTD LK AND
TERRAIN ENHANCEMENT N OF I 80 AND IN THE RIDGES. BLDG HIGH PRES
SHOULD END ANY RMNG SNW SHWRS AND FLURRIES FRI MRNG...THOUGH
INVERSION TRAPPED LLVL MSTR SHOULD KEEP CLDS ACRS THE RGN.

A SHRTWV ACRS THE SERN CONUS IS PROGGED TO BRING LOW CHCS FOR LGT
SNW WELL SE OF PIT LT SAT...THOUGH MDLS CONT TO TREND FURTHER S
WITH PCPN FM THIS SYSTEM. TEMPS SHOULD AVG A LTL BLO THE SEASONAL
AVGS.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE LONGWAVE PATTERN WILL BECOME MORE MERIDIONAL SUNDAY THROUGH
THE FIRST HALF OF NEXT WEEK AS A TROUGH OF LOW PRESSURE DIGS SOUTH
OVER THE CENTRAL US AND DEEPENS AS IT TRANSITIONS EASTWARD. LATEST
GUIDANCE SHOWS GOOD CONTINUITY WITH THIS FEATURE AND OVERALL ARE
IN FAIRLY GOOD AGREEMENT. WITH THAT AND LATEST RMOP AND MODTRENDS
VERY SIMILAR TO 24HRS AGO...OPTED TO ADJUST THE EXTENDED TO BE MORE IN
LINE WITH A BLEND OF THE 00Z WPC...EC...AND GEFS....WHICH
RESULTED IN A FAIRLY BIG INCREASE IN BOTH LOW AND MAX
TEMPERATURES TOWARDS THE MIDDLE OF THE WEEK WITH HIGHER CONFIDENCE
IN TIMING. CURRENTLY...THE BRUNT OF PRECIPITATION LOOKS TO FALL
OVERNIGHT TUESDAY THROUGH WEDNESDAY MORNING AS RAIN AHEAD OF THE
COLD FRONT UNDER STRONG WAA AND MOISTURE ADVECTION...WITH LATEST
ENSEMBLE GUIDANCE INDICATING V-COMPONENT ANOMALIES BY TUESDAY
AFTERNOON AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL. TEMPERATURES
ARE FORECAST TO BE AROUND 10 DEGREES ABOVE NORMAL BY TUESDAY
AFTERNOON...AND STAYING RELATIVELY WARM TUESDAY NIGHT AS STRONGER
SOUTHWEST SURFACE WINDS AHEAD OF THE SYSTEM KEEPS STRONG WAA IN
PLAY AND THE LOWER LEVELS MIXED. WHILE THE FINER DETAILS
CERTAINLY COULD CHANGE...LATEST MODEL PROGS SHOW COLD AIR BEHIND
THE FRONT FULLY INTO THE FORECAST AREA BY CHRISTMAS MORNING AT
WHICH TIME ALL PRECIPITATION WOULD CHANGEOVER TO SNOW. CHANGEOVER
SHOULD HAPPEN RELATIVELY QUICKLY...BUT THERE IS SOME UNCERTAINTY
ON HOW LONG WE MAY SEE MIXED PRECIPITATION BASED ON LATEST PROGGED
CRITICAL THICKNESSES. IN GENERAL...CURRENTLY AROUND ONE HALF INCH
OF LIQUID PRECIPITATION IS EXPECTED AT THIS TIME AHEAD OF THE COLD
FRONT WITH LIGHT SNOWFALL ON THE BACKSIDE. NOMADS REANALYSIS BASED
ON THE LATEST 00Z RUN GIVES AROUND A 50 PERCENT CHANCE OF AN INCH
OR SO OF SNOW FALLING ON THE BACKSIDE OF THE FRONT THE NIGHT OF
THE 24TH AND INTO THE 25TH.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
A PERSISTENT LOW LEVEL DECK OF STRATOCUMULUS WILL KEEP SITES
UNDER MVFR CIG RESTRICTIONS THROUGH THE MORNING...WITH SITES SOUTH OF
INTERSTATE 80 OCCASIONALLY IMPROVING TO VFR. THERE IS A SLIGHT
CHANCE SITES NORTH OF INTERSTATE 80 MAY BRIEFLY SEE IFR AT TIMES
WITH OCCASIONAL LIGHT FLURRIES.

OUTLOOK.../TONIGHT THROUGH MONDAY/...
PERIODIC CIG RESTRICTIONS WILL CONTINUE UNTIL BOUNDARY LAYER FLOW
BACKS TO THE SOUTHWEST ON SATURDAY AHEAD OF AN APPROACHING MID-
LEVEL TROUGH OF LOW PRESSURE.

&&

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

&&

$$







000
FXUS61 KPBZ 181422
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
922 AM EST THU DEC 18 2014

.SYNOPSIS...
A WEAK DISTURBANCE WILL CROSS THE REGION THIS EVENING...FOLLOWED
BY BUILDING HIGH PRESSURE FRIDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLDS WL CONT TDA WITH MRNG RAOBS SHOWING LLVL MSTR TRAPPED BLO A
TEMP INVERSION. A FEW FLURRIES OR LGT SNW SHWRS ARE PSBL...BUT
WITH THE SHALLOW MSTR LYR NOTHING SGFNT IS EXPD. TEMPS SHOULD AVG
A FEW DEG BLO THE SEASONAL AVG.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
A WK SHRTWV IS PROGGED TO ADVN ACRS THE RGN TNGT. WITH THE CONTD
LLVL MSTR AND TEMP INVERSION JUST SCT FLURRIES ARE EXPD...THOUGH A
FEW LGT ACCUMULATING SNW SHWRS ARE PSBL WITH SOME LTD LK AND
TERRAIN ENHANCEMENT N OF I 80 AND IN THE RIDGES. BLDG HIGH PRES
SHOULD END ANY RMNG SNW SHWRS AND FLURRIES FRI MRNG...THOUGH
INVERSION TRAPPED LLVL MSTR SHOULD KEEP CLDS ACRS THE RGN.

A SHRTWV ACRS THE SERN CONUS IS PROGGED TO BRING LOW CHCS FOR LGT
SNW WELL SE OF PIT LT SAT...THOUGH MDLS CONT TO TREND FURTHER S
WITH PCPN FM THIS SYSTEM. TEMPS SHOULD AVG A LTL BLO THE SEASONAL
AVGS.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE LONGWAVE PATTERN WILL BECOME MORE MERIDIONAL SUNDAY THROUGH
THE FIRST HALF OF NEXT WEEK AS A TROUGH OF LOW PRESSURE DIGS SOUTH
OVER THE CENTRAL US AND DEEPENS AS IT TRANSITIONS EASTWARD. LATEST
GUIDANCE SHOWS GOOD CONTINUITY WITH THIS FEATURE AND OVERALL ARE
IN FAIRLY GOOD AGREEMENT. WITH THAT AND LATEST RMOP AND MODTRENDS
VERY SIMILAR TO 24HRS AGO...OPTED TO ADJUST THE EXTENDED TO BE MORE IN
LINE WITH A BLEND OF THE 00Z WPC...EC...AND GEFS....WHICH
RESULTED IN A FAIRLY BIG INCREASE IN BOTH LOW AND MAX
TEMPERATURES TOWARDS THE MIDDLE OF THE WEEK WITH HIGHER CONFIDENCE
IN TIMING. CURRENTLY...THE BRUNT OF PRECIPITATION LOOKS TO FALL
OVERNIGHT TUESDAY THROUGH WEDNESDAY MORNING AS RAIN AHEAD OF THE
COLD FRONT UNDER STRONG WAA AND MOISTURE ADVECTION...WITH LATEST
ENSEMBLE GUIDANCE INDICATING V-COMPONENT ANOMALIES BY TUESDAY
AFTERNOON AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL. TEMPERATURES
ARE FORECAST TO BE AROUND 10 DEGREES ABOVE NORMAL BY TUESDAY
AFTERNOON...AND STAYING RELATIVELY WARM TUESDAY NIGHT AS STRONGER
SOUTHWEST SURFACE WINDS AHEAD OF THE SYSTEM KEEPS STRONG WAA IN
PLAY AND THE LOWER LEVELS MIXED. WHILE THE FINER DETAILS
CERTAINLY COULD CHANGE...LATEST MODEL PROGS SHOW COLD AIR BEHIND
THE FRONT FULLY INTO THE FORECAST AREA BY CHRISTMAS MORNING AT
WHICH TIME ALL PRECIPITATION WOULD CHANGEOVER TO SNOW. CHANGEOVER
SHOULD HAPPEN RELATIVELY QUICKLY...BUT THERE IS SOME UNCERTAINTY
ON HOW LONG WE MAY SEE MIXED PRECIPITATION BASED ON LATEST PROGGED
CRITICAL THICKNESSES. IN GENERAL...CURRENTLY AROUND ONE HALF INCH
OF LIQUID PRECIPITATION IS EXPECTED AT THIS TIME AHEAD OF THE COLD
FRONT WITH LIGHT SNOWFALL ON THE BACKSIDE. NOMADS REANALYSIS BASED
ON THE LATEST 00Z RUN GIVES AROUND A 50 PERCENT CHANCE OF AN INCH
OR SO OF SNOW FALLING ON THE BACKSIDE OF THE FRONT THE NIGHT OF
THE 24TH AND INTO THE 25TH.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
A PERSISTENT LOW LEVEL DECK OF STRATOCUMULUS WILL KEEP SITES
UNDER MVFR CIG RESTRICTIONS THROUGH THE MORNING...WITH SITES SOUTH OF
INTERSTATE 80 OCCASIONALLY IMPROVING TO VFR. THERE IS A SLIGHT
CHANCE SITES NORTH OF INTERSTATE 80 MAY BRIEFLY SEE IFR AT TIMES
WITH OCCASIONAL LIGHT FLURRIES.

OUTLOOK.../TONIGHT THROUGH MONDAY/...
PERIODIC CIG RESTRICTIONS WILL CONTINUE UNTIL BOUNDARY LAYER FLOW
BACKS TO THE SOUTHWEST ON SATURDAY AHEAD OF AN APPROACHING MID-
LEVEL TROUGH OF LOW PRESSURE.

&&

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

&&

$$








000
FXUS61 KPBZ 181138
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
638 AM EST THU DEC 18 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

NO UPDATES NEEDED EARLY THIS MORNING AS THE ONGOING FORECAST
ALIGNS WELL WITH LATEST OBSERVATIONAL TRENDS...PREV DISCUSSION
BELOW..

TEMPS THIS MORNING HAVE STAGNATED AS LLVL CAA HAS CEASED AND WITH
ABUNDANT CLOUD COVER BLANKETING THE AREA. LIGHT UPSLOPE SNOW
SHOWERS AND FLURRIES ACROSS THE NORTH WILL CONTINUE TO DWINDLE
THIS MORNING.

LAKE ENHANCED MOISTURE...SATURATING AND DEEPENING THE BOUNDARY
LAYER...WILL RETURN OVER OUR NRN 1/3 OF THE CWA BY MID-MORNING WITH
CHANCES OF SNOW SHOWERS PERSISTING THROUGHOUT THE NEAR TERM. THIS
AFTERNOON HI-RES MODELS KEEP LAKE EFFECT SNOW PRODUCTION ACTIVE
DESPITE NAM BUFR SOUNDINGS SHOW INVERSION HEIGHTS LOWERING AND A
SLIGHT WARMING OF THE MID-LEVELS. WILL MAINTAIN CHC POPS ACROSS THE
NRN TIER OF THE CWA.

ELSEWHERE...CLOUDS WILL CONTINUE TO BE EVER-PRESENT...BUT
INSUFFICIENT MOISTURE WILL PRECLUDE ANY PRECIPITATION. WITH LACK
OF SUNSHINE AND NO REAL CHANGE TO THE AIR MASS TO SPEAK OF...HIGH TEMPS
WILL REMAIN BELOW AVERAGE WITH MOST LOCATIONS FLIRTING WITH THE
FREEZING MARK. WINDS COULD MAKE IT FEEL ABOUT 5-10 DEGREES COLDER.
TAX

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
ANOTHER WEAK WAVE WILL PASS THROUGH THE AREA TONIGHT DEEPENING THE
BOUNDARY LAYER ACROSS THE NRN 1/2 OF THE CWA BY INJECTION OF
UPSTREAM LAKE MOISTURE. 00Z NAM SHOWS H85 MOISTURE PUSHING SOUTH
ACROSS LAKE ERIE LATE TONIGHT EMBEDDED IN THE BROAD WEAK TROF AXIS.
A COLD POOL COINCIDENT WITH THIS FEATURE WILL BRING H85 TEMPS BACK
TO NEAR -11C. WHILE NOT OPTIMAL...THE COLDER TEMPS ALOFT SHOULD AID
IN SNOW GENERATION WITH THE WEAK WAVE. WILL KEEP LIKELY POPS
CONFINED TO THE AREA NORTH OF I-80 WHERE LAKE ERIE ENHANCEMENT WILL
OCCUR...BUT DO EXPAND POPS SOUTH NEARING THE PITTSBURGH METRO AREA
AND SOUTH ALONG THE LAUREL AND CHESTNUT RIDGES. LITTLE TO NO
ACCUMULATION IS EXPECTED.

HIGH PRESSURE WILL FINALLY SQUASH ANY REMAIN CHANCE OF LIGHT SNOW
FRI. THE LLVL INVERSION WILL HOLD STEADY THROUGH FRI WITH MOISTURE
REMAINING TRAPPED UNDERNEATH...BUT EROSION OF THAT MOISTURE DOES
OCCUR. THIS SHOULD BE THE FIRST CHANCE TO HAVE AT LEAST SOME
SUNSHINE RETURN TO THE AREA.

THE NEXT SYSTEM IS POISED TO SKIRT OUR SOUTH AND EAST SAT IN THE
FORM OF AN OPEN WAVE. MODELS REMAIN SPLIT ON THE NRN EXTENT OF THE
PRECIPITATION AS DEEPER MOISTURE WILL BE FIGHTING HIGH PRESSURE
THROUGH ITS PROGRESSION THROUGH THE TN VALLEY. BACKED OFF POPS AND
SLOWED TIMING TO FALL IN LINE WITH THE LATEST GFS/ECMWF. AS OF THIS
ISSUANCE...EVEN THE SREF MEAN HAS FALLEN MORE IN LINE WITH THE
AFOREMENTIONED MODELS...BUCKING THE NRN TRACK IT CLUNG TO EARLIER.
TAX

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE LONGWAVE PATTERN WILL BECOME MORE MERIDIONAL SUNDAY THROUGH
THE FIRST HALF OF NEXT WEEK AS A TROUGH OF LOW PRESSURE DIGS SOUTH
OVER THE CENTRAL US AND DEEPENS AS IT TRANSITIONS EASTWARD. LATEST
GUIDANCE SHOWS GOOD CONTINUITY WITH THIS FEATURE AND OVERALL ARE
IN FAIRLY GOOD AGREEMENT. WITH THAT AND LATEST RMOP AND MODTRENDS
VERY SIMILAR TO 24HRS AGO...OPTED TO ADJUST THE EXTENDED TO BE MORE IN
LINE WITH A BLEND OF THE 00Z WPC...EC...AND GEFS....WHICH
RESULTED IN A FAIRLY BIG INCREASE IN BOTH LOW AND MAX
TEMPERATURES TOWARDS THE MIDDLE OF THE WEEK WITH HIGHER CONFIDENCE
IN TIMING. CURRENTLY...THE BRUNT OF PRECIPITATION LOOKS TO FALL
OVERNIGHT TUESDAY THROUGH WEDNESDAY MORNING AS RAIN AHEAD OF THE
COLD FRONT UNDER STRONG WAA AND MOISTURE ADVECTION...WITH LATEST
ENSEMBLE GUIDANCE INDICATING V-COMPONENT ANOMALIES BY TUESDAY
AFTERNOON AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL. TEMPERATURES
ARE FORECAST TO BE AROUND 10 DEGREES ABOVE NORMAL BY TUESDAY
AFTERNOON...AND STAYING RELATIVELY WARM TUESDAY NIGHT AS STRONGER
SOUTHWEST SURFACE WINDS AHEAD OF THE SYSTEM KEEPS STRONG WAA IN
PLAY AND THE LOWER LEVELS MIXED. WHILE THE FINER DETAILS
CERTAINLY COULD CHANGE...LATEST MODEL PROGS SHOW COLD AIR BEHIND
THE FRONT FULLY INTO THE FORECAST AREA BY CHRISTMAS MORNING AT
WHICH TIME ALL PRECIPITATION WOULD CHANGEOVER TO SNOW. CHANGEOVER
SHOULD HAPPEN RELATIVELY QUICKLY...BUT THERE IS SOME UNCERTAINTY
ON HOW LONG WE MAY SEE MIXED PRECIPITATION BASED ON LATEST PROGGED
CRITICAL THICKNESSES. IN GENERAL...CURRENTLY AROUND ONE HALF INCH
OF LIQUID PRECIPITATION IS EXPECTED AT THIS TIME AHEAD OF THE COLD
FRONT WITH LIGHT SNOWFALL ON THE BACKSIDE. NOMADS REANALYSIS BASED
ON THE LATEST 00Z RUN GIVES AROUND A 50 PERCENT CHANCE OF AN INCH
OR SO OF SNOW FALLING ON THE BACKSIDE OF THE FRONT THE NIGHT OF
THE 24TH AND INTO THE 25TH.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
A PERSISTENT LOW LEVEL DECK OF STRATOCUMULUS WILL KEEP SITES
UNDER MVFR CIG RESTRICTIONS THROUGH THE MORNING...WITH SITES SOUTH OF
INTERSTATE 80 OCCASIONALLY IMPROVING TO VFR AND SLIGHT CHANCE SITES
NORTH OF INTERSTATE 80 MAY BRIEFLY SEE IFR AT TIMES WITH
OCCASIONAL LIGHT FLURRIES.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/... PERIODIC CIG
RESTRICTIONS WILL CONTINUE UNTIL BOUNDARY LAYER FLOW BACKS TO THE
SOUTHWEST ON SATURDAY AHEAD OF AN APPROACHING MID-LEVEL TROUGH OF
LOW PRESSURE. &&

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

&&

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

&&

$$







000
FXUS61 KPBZ 181138
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
638 AM EST THU DEC 18 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

NO UPDATES NEEDED EARLY THIS MORNING AS THE ONGOING FORECAST
ALIGNS WELL WITH LATEST OBSERVATIONAL TRENDS...PREV DISCUSSION
BELOW..

TEMPS THIS MORNING HAVE STAGNATED AS LLVL CAA HAS CEASED AND WITH
ABUNDANT CLOUD COVER BLANKETING THE AREA. LIGHT UPSLOPE SNOW
SHOWERS AND FLURRIES ACROSS THE NORTH WILL CONTINUE TO DWINDLE
THIS MORNING.

LAKE ENHANCED MOISTURE...SATURATING AND DEEPENING THE BOUNDARY
LAYER...WILL RETURN OVER OUR NRN 1/3 OF THE CWA BY MID-MORNING WITH
CHANCES OF SNOW SHOWERS PERSISTING THROUGHOUT THE NEAR TERM. THIS
AFTERNOON HI-RES MODELS KEEP LAKE EFFECT SNOW PRODUCTION ACTIVE
DESPITE NAM BUFR SOUNDINGS SHOW INVERSION HEIGHTS LOWERING AND A
SLIGHT WARMING OF THE MID-LEVELS. WILL MAINTAIN CHC POPS ACROSS THE
NRN TIER OF THE CWA.

ELSEWHERE...CLOUDS WILL CONTINUE TO BE EVER-PRESENT...BUT
INSUFFICIENT MOISTURE WILL PRECLUDE ANY PRECIPITATION. WITH LACK
OF SUNSHINE AND NO REAL CHANGE TO THE AIR MASS TO SPEAK OF...HIGH TEMPS
WILL REMAIN BELOW AVERAGE WITH MOST LOCATIONS FLIRTING WITH THE
FREEZING MARK. WINDS COULD MAKE IT FEEL ABOUT 5-10 DEGREES COLDER.
TAX

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
ANOTHER WEAK WAVE WILL PASS THROUGH THE AREA TONIGHT DEEPENING THE
BOUNDARY LAYER ACROSS THE NRN 1/2 OF THE CWA BY INJECTION OF
UPSTREAM LAKE MOISTURE. 00Z NAM SHOWS H85 MOISTURE PUSHING SOUTH
ACROSS LAKE ERIE LATE TONIGHT EMBEDDED IN THE BROAD WEAK TROF AXIS.
A COLD POOL COINCIDENT WITH THIS FEATURE WILL BRING H85 TEMPS BACK
TO NEAR -11C. WHILE NOT OPTIMAL...THE COLDER TEMPS ALOFT SHOULD AID
IN SNOW GENERATION WITH THE WEAK WAVE. WILL KEEP LIKELY POPS
CONFINED TO THE AREA NORTH OF I-80 WHERE LAKE ERIE ENHANCEMENT WILL
OCCUR...BUT DO EXPAND POPS SOUTH NEARING THE PITTSBURGH METRO AREA
AND SOUTH ALONG THE LAUREL AND CHESTNUT RIDGES. LITTLE TO NO
ACCUMULATION IS EXPECTED.

HIGH PRESSURE WILL FINALLY SQUASH ANY REMAIN CHANCE OF LIGHT SNOW
FRI. THE LLVL INVERSION WILL HOLD STEADY THROUGH FRI WITH MOISTURE
REMAINING TRAPPED UNDERNEATH...BUT EROSION OF THAT MOISTURE DOES
OCCUR. THIS SHOULD BE THE FIRST CHANCE TO HAVE AT LEAST SOME
SUNSHINE RETURN TO THE AREA.

THE NEXT SYSTEM IS POISED TO SKIRT OUR SOUTH AND EAST SAT IN THE
FORM OF AN OPEN WAVE. MODELS REMAIN SPLIT ON THE NRN EXTENT OF THE
PRECIPITATION AS DEEPER MOISTURE WILL BE FIGHTING HIGH PRESSURE
THROUGH ITS PROGRESSION THROUGH THE TN VALLEY. BACKED OFF POPS AND
SLOWED TIMING TO FALL IN LINE WITH THE LATEST GFS/ECMWF. AS OF THIS
ISSUANCE...EVEN THE SREF MEAN HAS FALLEN MORE IN LINE WITH THE
AFOREMENTIONED MODELS...BUCKING THE NRN TRACK IT CLUNG TO EARLIER.
TAX

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE LONGWAVE PATTERN WILL BECOME MORE MERIDIONAL SUNDAY THROUGH
THE FIRST HALF OF NEXT WEEK AS A TROUGH OF LOW PRESSURE DIGS SOUTH
OVER THE CENTRAL US AND DEEPENS AS IT TRANSITIONS EASTWARD. LATEST
GUIDANCE SHOWS GOOD CONTINUITY WITH THIS FEATURE AND OVERALL ARE
IN FAIRLY GOOD AGREEMENT. WITH THAT AND LATEST RMOP AND MODTRENDS
VERY SIMILAR TO 24HRS AGO...OPTED TO ADJUST THE EXTENDED TO BE MORE IN
LINE WITH A BLEND OF THE 00Z WPC...EC...AND GEFS....WHICH
RESULTED IN A FAIRLY BIG INCREASE IN BOTH LOW AND MAX
TEMPERATURES TOWARDS THE MIDDLE OF THE WEEK WITH HIGHER CONFIDENCE
IN TIMING. CURRENTLY...THE BRUNT OF PRECIPITATION LOOKS TO FALL
OVERNIGHT TUESDAY THROUGH WEDNESDAY MORNING AS RAIN AHEAD OF THE
COLD FRONT UNDER STRONG WAA AND MOISTURE ADVECTION...WITH LATEST
ENSEMBLE GUIDANCE INDICATING V-COMPONENT ANOMALIES BY TUESDAY
AFTERNOON AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL. TEMPERATURES
ARE FORECAST TO BE AROUND 10 DEGREES ABOVE NORMAL BY TUESDAY
AFTERNOON...AND STAYING RELATIVELY WARM TUESDAY NIGHT AS STRONGER
SOUTHWEST SURFACE WINDS AHEAD OF THE SYSTEM KEEPS STRONG WAA IN
PLAY AND THE LOWER LEVELS MIXED. WHILE THE FINER DETAILS
CERTAINLY COULD CHANGE...LATEST MODEL PROGS SHOW COLD AIR BEHIND
THE FRONT FULLY INTO THE FORECAST AREA BY CHRISTMAS MORNING AT
WHICH TIME ALL PRECIPITATION WOULD CHANGEOVER TO SNOW. CHANGEOVER
SHOULD HAPPEN RELATIVELY QUICKLY...BUT THERE IS SOME UNCERTAINTY
ON HOW LONG WE MAY SEE MIXED PRECIPITATION BASED ON LATEST PROGGED
CRITICAL THICKNESSES. IN GENERAL...CURRENTLY AROUND ONE HALF INCH
OF LIQUID PRECIPITATION IS EXPECTED AT THIS TIME AHEAD OF THE COLD
FRONT WITH LIGHT SNOWFALL ON THE BACKSIDE. NOMADS REANALYSIS BASED
ON THE LATEST 00Z RUN GIVES AROUND A 50 PERCENT CHANCE OF AN INCH
OR SO OF SNOW FALLING ON THE BACKSIDE OF THE FRONT THE NIGHT OF
THE 24TH AND INTO THE 25TH.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
A PERSISTENT LOW LEVEL DECK OF STRATOCUMULUS WILL KEEP SITES
UNDER MVFR CIG RESTRICTIONS THROUGH THE MORNING...WITH SITES SOUTH OF
INTERSTATE 80 OCCASIONALLY IMPROVING TO VFR AND SLIGHT CHANCE SITES
NORTH OF INTERSTATE 80 MAY BRIEFLY SEE IFR AT TIMES WITH
OCCASIONAL LIGHT FLURRIES.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/... PERIODIC CIG
RESTRICTIONS WILL CONTINUE UNTIL BOUNDARY LAYER FLOW BACKS TO THE
SOUTHWEST ON SATURDAY AHEAD OF AN APPROACHING MID-LEVEL TROUGH OF
LOW PRESSURE. &&

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

&&

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

&&

$$








000
FXUS61 KPBZ 180925
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
404 AM EST THU DEC 18 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TEMPS THIS MORNING HAVE STAGNATED AS LLVL CAA HAS CEASED AND WITH
ABUNDANT CLOUD COVER BLANKETING THE AREA. LIGHT UPSLOPE SNOW SHOWERS
AND FLURRIES ACROSS THE NORTH WILL CONTINUE TO DWINDLE THIS
MORNING.

LAKE ENHANCED MOISTURE...SATURATING AND DEEPENING THE BOUNDARY
LAYER...WILL RETURN OVER OUR NRN 1/3 OF THE CWA BY MID-MORNING WITH
CHANCES OF SNOW SHOWERS PERSISTING THROUGHOUT THE NEAR TERM. THIS
AFTERNOON HI-RES MODELS KEEP LAKE EFFECT SNOW PRODUCTION ACTIVE
DESPITE NAM BUFR SOUNDINGS SHOW INVERSION HEIGHTS LOWERING AND A
SLIGHT WARMING OF THE MID-LEVELS. WILL MAINTAIN CHC POPS ACROSS THE
NRN TIER OF THE CWA.

ELSEWHERE...CLOUDS WILL CONTINUE TO BE EVER-PRESENT...BUT
INSUFFICIENT MOISTURE WILL PRECLUDE ANY PRECIPITATION. WITH LACK
OF SUNSHINE AND NO REAL CHANGE TO THE AIR MASS TO SPEAK OF...HIGH TEMPS
WILL REMAIN BELOW AVERAGE WITH MOST LOCATIONS FLIRTING WITH THE
FREEZING MARK. WINDS COULD MAKE IT FEEL ABOUT 5-10 DEGREES COLDER.
TAX

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
ANOTHER WEAK WAVE WILL PASS THROUGH THE AREA TONIGHT DEEPENING THE
BOUNDARY LAYER ACROSS THE NRN 1/2 OF THE CWA BY INJECTION OF
UPSTREAM LAKE MOISTURE. 00Z NAM SHOWS H85 MOISTURE PUSHING SOUTH
ACROSS LAKE ERIE LATE TONIGHT EMBEDDED IN THE BROAD WEAK TROF AXIS.
A COLD POOL COINCIDENT WITH THIS FEATURE WILL BRING H85 TEMPS BACK
TO NEAR -11C. WHILE NOT OPTIMAL...THE COLDER TEMPS ALOFT SHOULD AID
IN SNOW GENERATION WITH THE WEAK WAVE. WILL KEEP LIKELY POPS
CONFINED TO THE AREA NORTH OF I-80 WHERE LAKE ERIE ENHANCEMENT WILL
OCCUR...BUT DO EXPAND POPS SOUTH NEARING THE PITTSBURGH METRO AREA
AND SOUTH ALONG THE LAUREL AND CHESTNUT RIDGES. LITTLE TO NO
ACCUMULATION IS EXPECTED.

HIGH PRESSURE WILL FINALLY SQUASH ANY REMAIN CHANCE OF LIGHT SNOW
FRI. THE LLVL INVERSION WILL HOLD STEADY THROUGH FRI WITH MOISTURE
REMAINING TRAPPED UNDERNEATH...BUT EROSION OF THAT MOISTURE DOES
OCCUR. THIS SHOULD BE THE FIRST CHANCE TO HAVE AT LEAST SOME
SUNSHINE RETURN TO THE AREA.

THE NEXT SYSTEM IS POISED TO SKIRT OUR SOUTH AND EAST SAT IN THE
FORM OF AN OPEN WAVE. MODELS REMAIN SPLIT ON THE NRN EXTENT OF THE
PRECIPITATION AS DEEPER MOISTURE WILL BE FIGHTING HIGH PRESSURE
THROUGH ITS PROGRESSION THROUGH THE TN VALLEY. BACKED OFF POPS AND
SLOWED TIMING TO FALL IN LINE WITH THE LATEST GFS/ECMWF. AS OF THIS
ISSUANCE...EVEN THE SREF MEAN HAS FALLEN MORE IN LINE WITH THE
AFOREMENTIONED MODELS...BUCKING THE NRN TRACK IT CLUNG TO EARLIER.
TAX

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE LONGWAVE PATTERN WILL BECOME MORE MERIDIONAL SUNDAY THROUGH
THE FIRST HALF OF NEXT WEEK AS A TROUGH OF LOW PRESSURE DIGS SOUTH
OVER THE CENTRAL US AND DEEPENS AS IT TRANSITIONS EASTWARD. LATEST
GUIDANCE SHOWS GOOD CONTINUITY WITH THIS FEATURE AND OVERALL ARE
IN FAIRLY GOOD AGREEMENT. WITH THAT AND LATEST RMOP AND MODTRENDS
VERY SIMILAR TO 24HRS AGO...OPTED TO ADJUST THE EXTENDED TO BE MORE IN
LINE WITH A BLEND OF THE 00Z WPC...EC...AND GEFS....WHICH
RESULTED IN A FAIRLY BIG INCREASE IN BOTH LOW AND MAX
TEMPERATURES TOWARDS THE MIDDLE OF THE WEEK WITH HIGHER CONFIDENCE
IN TIMING. CURRENTLY...THE BRUNT OF PRECIPITATION LOOKS TO FALL
OVERNIGHT TUESDAY THROUGH WEDNESDAY MORNING AS RAIN AHEAD OF THE
COLD FRONT UNDER STRONG WAA AND MOISTURE ADVECTION...WITH LATEST
ENSEMBLE GUIDANCE INDICATING V-COMPONENT ANOMALIES BY TUESDAY
AFTERNOON AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL. TEMPERATURES
ARE FORECAST TO BE AROUND 10 DEGREES ABOVE NORMAL BY TUESDAY
AFTERNOON...AND STAYING RELATIVELY WARM TUESDAY NIGHT AS STRONGER
SOUTHWEST SURFACE WINDS AHEAD OF THE SYSTEM KEEPS STRONG WAA IN
PLAY AND THE LOWER LEVELS MIXED. WHILE THE FINER DETAILS
CERTAINLY COULD CHANGE...LATEST MODEL PROGS SHOW COLD AIR BEHIND
THE FRONT FULLY INTO THE FORECAST AREA BY CHRISTMAS MORNING AT
WHICH TIME ALL PRECIPITATION WOULD CHANGEOVER TO SNOW. CHANGEOVER
SHOULD HAPPEN RELATIVELY QUICKLY...BUT THERE IS SOME UNCERTAINTY
ON HOW LONG WE MAY SEE MIXED PRECIPITATION BASED ON LATEST PROGGED
CRITICAL THICKNESSES. IN GENERAL...CURRENTLY AROUND ONE HALF INCH
OF LIQUID PRECIPITATION IS EXPECTED AT THIS TIME AHEAD OF THE COLD
FRONT WITH LIGHT SNOWFALL ON THE BACKSIDE. NOMADS REANALYSIS BASED
ON THE LATEST 00Z RUN GIVES AROUND A 50 PERCENT CHANCE OF AN INCH
OR SO OF SNOW FALLING ON THE BACKSIDE OF THE FRONT THE NIGHT OF
THE 24TH AND INTO THE 25TH.

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
A PERSISTENT LOW LEVEL DECK OF STRATOCUMULUS WILL KEEP SITES
UNDER MVFR CIG RESTRICTIONS TODAY...WITH SITES SOUTH OF INTERSTATE 80
OCCASIONALLY IMPROVING TO VFR WHILE SITES NORTH OF INTERSTATE 80 MAY
SEE IFR AT TIMES WITH OCCASIONAL LIGHT FLURRIES.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/... PERIODIC CIG
RESTRICTIONS WILL CONTINUE UNTIL BOUNDARY LAYER FLOW BACKS TO THE
SOUTHWEST ON SATURDAY AHEAD OF AN APPROACHING MID-LEVEL TROUGH OF
LOW PRESSURE. &&

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

&&

$$










000
FXUS61 KPBZ 180641
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
141 AM EST THU DEC 18 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
LIGHT SNOW SHOWERS AND FLURRIES PERSIST AS THE TAIL VORT PASSES
EAST EMBEDDED IN THE UPPER TROF AXIS. AS THE AXIS PASSES...LOW TO
MID-LEVEL FLOW WILL VEER FROM WRLY TO NWRLY ALLOWING FOR CONTINUED
PENETRATION OF LAKE MOISTURE INTO OUR NRN ZONES...EVEN AS THE SFC
WINDS REMAIN LARGELY OUT OF THE WEST. DRY MID-LEVEL AIR WILL BE
SLOWLY SHUNTING THE DEEPER MOISTURE TO THE NE AT LEAST TEMPORARILY
THIS MORNING...SO AM EXPECTING LIGHT SNOW SHOWERS OVER THE
PITTSBURGH METRO AREA TO CEASE. COLDEST H85 TEMPS ARE BEING
REALIZED NOW THROUGH ABOUT 12Z PER THE NAM BUFR SOUNDINGS...AND
THE DENDRITIC GROWTH ZONE OVERLAPS THE SHALLOW MOIST LAYER. EXPECTING
THE BEST CHANCES FOR ACCUMULATING SNOW THROUGH 12Z...ALTHOUGH GENERALLY
LESS THAN AN INCH IS EXPECTED.

LAKE ENHANCED MOISTURE...SATURATING AND DEEPENING THE BOUNDARY...LAYER
WILL REMAIN OVER OUR NRN 1/3 OF THE CWA TODAY WITH CHANCES OF SNOW
SHOWERS PERSISTING THROUGHOUT. THIS AFTERNOON HI-RES MODELS KEEP
LAKE EFFECT SNOW PRODUCTION ACTIVE DESPITE NAM BUFR SOUNDINGS SHOW
INVERSION HEIGHTS LOWERING AND A SLIGHT WARMING OF THE MID-LEVELS.
WITH THIS IN MIND...AM EXPECTING SPATIAL COVERAGE AND INTENSITY TO
DWINDLE SIGNIFICANTLY FROM MID-MORNING THOUGH THE EVENING.

ELSEWHERE...CLOUDS WILL CONTINUE TO BE EVER-PRESENT...BUT
INSUFFICIENT MOISTURE WILL PRECLUDE ANY PRECIPITATION. WITH LACK
OF SUNSHINE AND NO REAL CHANGE TO THE AIR MASS TO SPEAK OF...HIGH TEMPS
WILL REMAIN BELOW AVERAGE WITH MOST LOCATIONS FLIRTING WITH THE
FREEZING MARK. WINDS COULD MAKE IT FEEL ABOUT 5-10 DEGREES COLDER.
TAX

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...
FAST MOVING SHORTWAVE WILL KEEP CLOUDS AND A FEW SNOW SHOWERS
MAINLY ACROSS THE NORTH THURSDAY NIGHT...ENDING EARLY FRIDAY AS
SURFACE RIDGE NOSES INTO THE REGION. WEAK SOUTHERN STREAM SYSTEM
WILL APPROACH LATE SATURDAY WITH CHC POPS ACROSS THE FAR SOUTH FOR
LIGHT SNOW. BULK OF MOISTURE WITH THIS SYSTEM WILL REMAIN WELL
SOUTH OF THE REGION AS IT QUICKLY SHIFTS EAST BY EARLY SUNDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. ANOTHER SHOT OF COLD
AIR TONIGHT WILL ALSO BRING THE THREAT FOR SNOW SHOWERS/FLURRIES...
PARTICULARLY AT NORTHERN PORTS.


OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/... PERIODIC CIG
RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS ON SATURDAY
IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO INTIATE ANOTHER
ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$







000
FXUS61 KPBZ 180641
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
141 AM EST THU DEC 18 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
LIGHT SNOW SHOWERS AND FLURRIES PERSIST AS THE TAIL VORT PASSES
EAST EMBEDDED IN THE UPPER TROF AXIS. AS THE AXIS PASSES...LOW TO
MID-LEVEL FLOW WILL VEER FROM WRLY TO NWRLY ALLOWING FOR CONTINUED
PENETRATION OF LAKE MOISTURE INTO OUR NRN ZONES...EVEN AS THE SFC
WINDS REMAIN LARGELY OUT OF THE WEST. DRY MID-LEVEL AIR WILL BE
SLOWLY SHUNTING THE DEEPER MOISTURE TO THE NE AT LEAST TEMPORARILY
THIS MORNING...SO AM EXPECTING LIGHT SNOW SHOWERS OVER THE
PITTSBURGH METRO AREA TO CEASE. COLDEST H85 TEMPS ARE BEING
REALIZED NOW THROUGH ABOUT 12Z PER THE NAM BUFR SOUNDINGS...AND
THE DENDRITIC GROWTH ZONE OVERLAPS THE SHALLOW MOIST LAYER. EXPECTING
THE BEST CHANCES FOR ACCUMULATING SNOW THROUGH 12Z...ALTHOUGH GENERALLY
LESS THAN AN INCH IS EXPECTED.

LAKE ENHANCED MOISTURE...SATURATING AND DEEPENING THE BOUNDARY...LAYER
WILL REMAIN OVER OUR NRN 1/3 OF THE CWA TODAY WITH CHANCES OF SNOW
SHOWERS PERSISTING THROUGHOUT. THIS AFTERNOON HI-RES MODELS KEEP
LAKE EFFECT SNOW PRODUCTION ACTIVE DESPITE NAM BUFR SOUNDINGS SHOW
INVERSION HEIGHTS LOWERING AND A SLIGHT WARMING OF THE MID-LEVELS.
WITH THIS IN MIND...AM EXPECTING SPATIAL COVERAGE AND INTENSITY TO
DWINDLE SIGNIFICANTLY FROM MID-MORNING THOUGH THE EVENING.

ELSEWHERE...CLOUDS WILL CONTINUE TO BE EVER-PRESENT...BUT
INSUFFICIENT MOISTURE WILL PRECLUDE ANY PRECIPITATION. WITH LACK
OF SUNSHINE AND NO REAL CHANGE TO THE AIR MASS TO SPEAK OF...HIGH TEMPS
WILL REMAIN BELOW AVERAGE WITH MOST LOCATIONS FLIRTING WITH THE
FREEZING MARK. WINDS COULD MAKE IT FEEL ABOUT 5-10 DEGREES COLDER.
TAX

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...
FAST MOVING SHORTWAVE WILL KEEP CLOUDS AND A FEW SNOW SHOWERS
MAINLY ACROSS THE NORTH THURSDAY NIGHT...ENDING EARLY FRIDAY AS
SURFACE RIDGE NOSES INTO THE REGION. WEAK SOUTHERN STREAM SYSTEM
WILL APPROACH LATE SATURDAY WITH CHC POPS ACROSS THE FAR SOUTH FOR
LIGHT SNOW. BULK OF MOISTURE WITH THIS SYSTEM WILL REMAIN WELL
SOUTH OF THE REGION AS IT QUICKLY SHIFTS EAST BY EARLY SUNDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. ANOTHER SHOT OF COLD
AIR TONIGHT WILL ALSO BRING THE THREAT FOR SNOW SHOWERS/FLURRIES...
PARTICULARLY AT NORTHERN PORTS.


OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/... PERIODIC CIG
RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS ON SATURDAY
IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO INTIATE ANOTHER
ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$








000
FXUS61 KPBZ 180152
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
852 PM EST WED DEC 17 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...
COLD ADVECTION IS WELL UNDERWAY ACROSS THE CWA...AND AS FLOW
TRENDS MORE TOWARD THE NORTHWEST OVERNIGHT WITH THE LOW LEVEL
UNSTABLE MOIST LAYER BEGINNING TO INTERSECT THE LOWER PORTION OF
THE DENDRITIC GROWTH ZONE...SNOW SHOWERS AND FLURRIES SHOULD START
TO BECOME A BIT MORE COMMON TOWARD MIDNIGHT. THIS SHIFT IN THE
FLOW COINCIDES WITH THE PASSAGE OF A FAIRLY VIGOROUS SHORT WAVE
TROUGH THAT IS MANAGING TO INCREASE COVERAGE ON KCLE THIS EVENING
QUITE SUBSTANTIALLY. AS SUCH...A PERIOD OF SNOW SHOWERS AND
FLURRIES...ESPECIALLY ALONG AND NORTH OF THE TURNPIKE SEEMS A VERY
GOOD BET. HOWEVER...THE BEST CHANCE OF MEASURABLE SNOWS STILL
LOOKS TO BE ALONG AND NORTH OF I-80 AS WELL AS IN THE RIDGES AS
THE NORTHWESTERLY FLOW BECOMES MORE FAVORABLE FOR SUCH
DEVELOPMENT. THAT SAID...ACCUMULATIONS ANYWHERE SHOULD BE FAIRLY
MINIMAL AS SHALLOW MOISTURE AND POOR LIFT ALONG WITH SOME DEGREE
OF RIMING SHOULD YIELD POOR QPF AND NO BETTER THAN CLIMO SNOW TO
LIQUID RATIOS. AS A RESULT...EVEN IN THE FAVORED AREAS...REALLY
ONLY ABOVE A HALF AN INCH OF SNOW IS EXPECTED OVERNIGHT. FRIES

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FAST MOVING SHORTWAVE WILL KEEP CLOUDS AND A FEW SNOW SHOWERS
MAINLY ACROSS THE NORTH THURSDAY NIGHT...ENDING EARLY FRIDAY AS
SURFACE RIDGE NOSES INTO THE REGION. WEAK SOUTHERN STREAM SYSTEM
WILL APPROACH LATE SATURDAY WITH CHC POPS ACROSS THE FAR SOUTH FOR
LIGHT SNOW. BULK OF MOISTURE WITH THIS SYSTEM WILL REMAIN WELL
SOUTH OF THE REGION AS IT QUICKLY SHIFTS EAST BY EARLY SUNDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. ANOTHER SHOT OF COLD
AIR TONIGHT WILL ALSO BRING THE THREAT FOR SNOW SHOWERS/FLURRIES...
PARTICULARLY AT NORTHERN PORTS.


OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/... PERIODIC CIG
RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS ON SATURDAY
IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO INTIATE ANOTHER
ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$







000
FXUS61 KPBZ 180152
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
852 PM EST WED DEC 17 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...
COLD ADVECTION IS WELL UNDERWAY ACROSS THE CWA...AND AS FLOW
TRENDS MORE TOWARD THE NORTHWEST OVERNIGHT WITH THE LOW LEVEL
UNSTABLE MOIST LAYER BEGINNING TO INTERSECT THE LOWER PORTION OF
THE DENDRITIC GROWTH ZONE...SNOW SHOWERS AND FLURRIES SHOULD START
TO BECOME A BIT MORE COMMON TOWARD MIDNIGHT. THIS SHIFT IN THE
FLOW COINCIDES WITH THE PASSAGE OF A FAIRLY VIGOROUS SHORT WAVE
TROUGH THAT IS MANAGING TO INCREASE COVERAGE ON KCLE THIS EVENING
QUITE SUBSTANTIALLY. AS SUCH...A PERIOD OF SNOW SHOWERS AND
FLURRIES...ESPECIALLY ALONG AND NORTH OF THE TURNPIKE SEEMS A VERY
GOOD BET. HOWEVER...THE BEST CHANCE OF MEASURABLE SNOWS STILL
LOOKS TO BE ALONG AND NORTH OF I-80 AS WELL AS IN THE RIDGES AS
THE NORTHWESTERLY FLOW BECOMES MORE FAVORABLE FOR SUCH
DEVELOPMENT. THAT SAID...ACCUMULATIONS ANYWHERE SHOULD BE FAIRLY
MINIMAL AS SHALLOW MOISTURE AND POOR LIFT ALONG WITH SOME DEGREE
OF RIMING SHOULD YIELD POOR QPF AND NO BETTER THAN CLIMO SNOW TO
LIQUID RATIOS. AS A RESULT...EVEN IN THE FAVORED AREAS...REALLY
ONLY ABOVE A HALF AN INCH OF SNOW IS EXPECTED OVERNIGHT. FRIES

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FAST MOVING SHORTWAVE WILL KEEP CLOUDS AND A FEW SNOW SHOWERS
MAINLY ACROSS THE NORTH THURSDAY NIGHT...ENDING EARLY FRIDAY AS
SURFACE RIDGE NOSES INTO THE REGION. WEAK SOUTHERN STREAM SYSTEM
WILL APPROACH LATE SATURDAY WITH CHC POPS ACROSS THE FAR SOUTH FOR
LIGHT SNOW. BULK OF MOISTURE WITH THIS SYSTEM WILL REMAIN WELL
SOUTH OF THE REGION AS IT QUICKLY SHIFTS EAST BY EARLY SUNDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. ANOTHER SHOT OF COLD
AIR TONIGHT WILL ALSO BRING THE THREAT FOR SNOW SHOWERS/FLURRIES...
PARTICULARLY AT NORTHERN PORTS.


OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/... PERIODIC CIG
RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS ON SATURDAY
IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO INTIATE ANOTHER
ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$







000
FXUS61 KPBZ 180152
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
852 PM EST WED DEC 17 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...
COLD ADVECTION IS WELL UNDERWAY ACROSS THE CWA...AND AS FLOW
TRENDS MORE TOWARD THE NORTHWEST OVERNIGHT WITH THE LOW LEVEL
UNSTABLE MOIST LAYER BEGINNING TO INTERSECT THE LOWER PORTION OF
THE DENDRITIC GROWTH ZONE...SNOW SHOWERS AND FLURRIES SHOULD START
TO BECOME A BIT MORE COMMON TOWARD MIDNIGHT. THIS SHIFT IN THE
FLOW COINCIDES WITH THE PASSAGE OF A FAIRLY VIGOROUS SHORT WAVE
TROUGH THAT IS MANAGING TO INCREASE COVERAGE ON KCLE THIS EVENING
QUITE SUBSTANTIALLY. AS SUCH...A PERIOD OF SNOW SHOWERS AND
FLURRIES...ESPECIALLY ALONG AND NORTH OF THE TURNPIKE SEEMS A VERY
GOOD BET. HOWEVER...THE BEST CHANCE OF MEASURABLE SNOWS STILL
LOOKS TO BE ALONG AND NORTH OF I-80 AS WELL AS IN THE RIDGES AS
THE NORTHWESTERLY FLOW BECOMES MORE FAVORABLE FOR SUCH
DEVELOPMENT. THAT SAID...ACCUMULATIONS ANYWHERE SHOULD BE FAIRLY
MINIMAL AS SHALLOW MOISTURE AND POOR LIFT ALONG WITH SOME DEGREE
OF RIMING SHOULD YIELD POOR QPF AND NO BETTER THAN CLIMO SNOW TO
LIQUID RATIOS. AS A RESULT...EVEN IN THE FAVORED AREAS...REALLY
ONLY ABOVE A HALF AN INCH OF SNOW IS EXPECTED OVERNIGHT. FRIES

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FAST MOVING SHORTWAVE WILL KEEP CLOUDS AND A FEW SNOW SHOWERS
MAINLY ACROSS THE NORTH THURSDAY NIGHT...ENDING EARLY FRIDAY AS
SURFACE RIDGE NOSES INTO THE REGION. WEAK SOUTHERN STREAM SYSTEM
WILL APPROACH LATE SATURDAY WITH CHC POPS ACROSS THE FAR SOUTH FOR
LIGHT SNOW. BULK OF MOISTURE WITH THIS SYSTEM WILL REMAIN WELL
SOUTH OF THE REGION AS IT QUICKLY SHIFTS EAST BY EARLY SUNDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. ANOTHER SHOT OF COLD
AIR TONIGHT WILL ALSO BRING THE THREAT FOR SNOW SHOWERS/FLURRIES...
PARTICULARLY AT NORTHERN PORTS.


OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/... PERIODIC CIG
RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS ON SATURDAY
IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO INTIATE ANOTHER
ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$








000
FXUS61 KPBZ 180152
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
852 PM EST WED DEC 17 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...
COLD ADVECTION IS WELL UNDERWAY ACROSS THE CWA...AND AS FLOW
TRENDS MORE TOWARD THE NORTHWEST OVERNIGHT WITH THE LOW LEVEL
UNSTABLE MOIST LAYER BEGINNING TO INTERSECT THE LOWER PORTION OF
THE DENDRITIC GROWTH ZONE...SNOW SHOWERS AND FLURRIES SHOULD START
TO BECOME A BIT MORE COMMON TOWARD MIDNIGHT. THIS SHIFT IN THE
FLOW COINCIDES WITH THE PASSAGE OF A FAIRLY VIGOROUS SHORT WAVE
TROUGH THAT IS MANAGING TO INCREASE COVERAGE ON KCLE THIS EVENING
QUITE SUBSTANTIALLY. AS SUCH...A PERIOD OF SNOW SHOWERS AND
FLURRIES...ESPECIALLY ALONG AND NORTH OF THE TURNPIKE SEEMS A VERY
GOOD BET. HOWEVER...THE BEST CHANCE OF MEASURABLE SNOWS STILL
LOOKS TO BE ALONG AND NORTH OF I-80 AS WELL AS IN THE RIDGES AS
THE NORTHWESTERLY FLOW BECOMES MORE FAVORABLE FOR SUCH
DEVELOPMENT. THAT SAID...ACCUMULATIONS ANYWHERE SHOULD BE FAIRLY
MINIMAL AS SHALLOW MOISTURE AND POOR LIFT ALONG WITH SOME DEGREE
OF RIMING SHOULD YIELD POOR QPF AND NO BETTER THAN CLIMO SNOW TO
LIQUID RATIOS. AS A RESULT...EVEN IN THE FAVORED AREAS...REALLY
ONLY ABOVE A HALF AN INCH OF SNOW IS EXPECTED OVERNIGHT. FRIES

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FAST MOVING SHORTWAVE WILL KEEP CLOUDS AND A FEW SNOW SHOWERS
MAINLY ACROSS THE NORTH THURSDAY NIGHT...ENDING EARLY FRIDAY AS
SURFACE RIDGE NOSES INTO THE REGION. WEAK SOUTHERN STREAM SYSTEM
WILL APPROACH LATE SATURDAY WITH CHC POPS ACROSS THE FAR SOUTH FOR
LIGHT SNOW. BULK OF MOISTURE WITH THIS SYSTEM WILL REMAIN WELL
SOUTH OF THE REGION AS IT QUICKLY SHIFTS EAST BY EARLY SUNDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. ANOTHER SHOT OF COLD
AIR TONIGHT WILL ALSO BRING THE THREAT FOR SNOW SHOWERS/FLURRIES...
PARTICULARLY AT NORTHERN PORTS.


OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/... PERIODIC CIG
RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS ON SATURDAY
IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO INTIATE ANOTHER
ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$








000
FXUS61 KPBZ 172343 AAB
AFDPBZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PITTSBURGH PA
643 PM EST WED DEC 17 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...
COLD ADVECTION IS WELL UNDERWAY ACROSS THE CWA...AND AS FLOW
TRENDS MORE TOWARD THE NORTHWEST OVERNIGHT WITH THE LOW LEVEL
UNSTABLE MOIST LAYER BEGINNING TO INTERSECT THE LOWER PORTION OF
THE DENDRITIC GROWTH ZONE...SNOW SHOWERS AND FLURRIES SHOULD START
TO BECOME A BIT MORE COMMON TOWARD MIDNIGHT. THIS WILL BE
PARTICULARLY TRUE ALONG AND NORTH OF I-80 AS WELL AS IN THE RIDGES
AS THE NORTHWESTERLY FLOW BECOMES MORE FAVORABLE FOR SUCH
DEVELOPMENT. FLURRIES WILL BE POSSIBLE ANYWHERE IN THE CWA OWING
TO THE AIR MASS CHANGE AND STILL STRONG ADVECTION WITH UNSTABLE
BOUNDARY LAYER...HOWEVER THE BEST CHANCES WILL BE UP NORTH AND IN
THE RIDGES. ACCUMULATIONS ANYWHERE SHOULD BE FAIRLY MINIMAL AS
SHALLOW MOISTURE AND POOR LIFT ALONG WITH SOME DEGREE OF RIMING
SHOULD YIELD POOR QPF AND NO BETTER THAN CLIMO SNOW TO LIQUID
RATIOS. AS A RESULT...EVEN IN THE FAVORED AREAS...REALLY ONLY
ABOVE A HALF AN INCH OF SNOW IS EXPECTED OVERNIGHT. FRIES

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FAST MOVING SHORTWAVE WILL KEEP CLOUDS AND A FEW SNOW SHOWERS
MAINLY ACROSS THE NORTH THURSDAY NIGHT...ENDING EARLY FRIDAY AS
SURFACE RIDGE NOSES INTO THE REGION. WEAK SOUTHERN STREAM SYSTEM
WILL APPROACH LATE SATURDAY WITH CHC POPS ACROSS THE FAR SOUTH FOR
LIGHT SNOW. BULK OF MOISTURE WITH THIS SYSTEM WILL REMAIN WELL
SOUTH OF THE REGION AS IT QUICKLY SHIFTS EAST BY EARLY SUNDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. ANOTHER SHOT OF COLD
AIR TONIGHT WILL ALSO BRING THE THREAT FOR SNOW SHOWERS/FLURRIES...
PARTICULARLY AT NORTHERN PORTS.


OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/... PERIODIC CIG
RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS ON SATURDAY
IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO INTIATE ANOTHER
ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$







000
FXUS61 KPBZ 172343 AAB
AFDPBZ

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PITTSBURGH PA
643 PM EST WED DEC 17 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...
COLD ADVECTION IS WELL UNDERWAY ACROSS THE CWA...AND AS FLOW
TRENDS MORE TOWARD THE NORTHWEST OVERNIGHT WITH THE LOW LEVEL
UNSTABLE MOIST LAYER BEGINNING TO INTERSECT THE LOWER PORTION OF
THE DENDRITIC GROWTH ZONE...SNOW SHOWERS AND FLURRIES SHOULD START
TO BECOME A BIT MORE COMMON TOWARD MIDNIGHT. THIS WILL BE
PARTICULARLY TRUE ALONG AND NORTH OF I-80 AS WELL AS IN THE RIDGES
AS THE NORTHWESTERLY FLOW BECOMES MORE FAVORABLE FOR SUCH
DEVELOPMENT. FLURRIES WILL BE POSSIBLE ANYWHERE IN THE CWA OWING
TO THE AIR MASS CHANGE AND STILL STRONG ADVECTION WITH UNSTABLE
BOUNDARY LAYER...HOWEVER THE BEST CHANCES WILL BE UP NORTH AND IN
THE RIDGES. ACCUMULATIONS ANYWHERE SHOULD BE FAIRLY MINIMAL AS
SHALLOW MOISTURE AND POOR LIFT ALONG WITH SOME DEGREE OF RIMING
SHOULD YIELD POOR QPF AND NO BETTER THAN CLIMO SNOW TO LIQUID
RATIOS. AS A RESULT...EVEN IN THE FAVORED AREAS...REALLY ONLY
ABOVE A HALF AN INCH OF SNOW IS EXPECTED OVERNIGHT. FRIES

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FAST MOVING SHORTWAVE WILL KEEP CLOUDS AND A FEW SNOW SHOWERS
MAINLY ACROSS THE NORTH THURSDAY NIGHT...ENDING EARLY FRIDAY AS
SURFACE RIDGE NOSES INTO THE REGION. WEAK SOUTHERN STREAM SYSTEM
WILL APPROACH LATE SATURDAY WITH CHC POPS ACROSS THE FAR SOUTH FOR
LIGHT SNOW. BULK OF MOISTURE WITH THIS SYSTEM WILL REMAIN WELL
SOUTH OF THE REGION AS IT QUICKLY SHIFTS EAST BY EARLY SUNDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. ANOTHER SHOT OF COLD
AIR TONIGHT WILL ALSO BRING THE THREAT FOR SNOW SHOWERS/FLURRIES...
PARTICULARLY AT NORTHERN PORTS.


OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/... PERIODIC CIG
RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS ON SATURDAY
IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO INTIATE ANOTHER
ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$








000
FXUS61 KPBZ 172301
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
601 PM EST WED DEC 17 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...
COLD ADVECTION IS WELL UNDERWAY ACROSS THE CWA...AND AS FLOW
TRENDS MORE TOWARD THE NORTHWEST OVERNIGHT WITH THE LOW LEVEL
UNSTABLE MOIST LAYER BEGINNING TO INTERSECT THE LOWER PORTION OF
THE DENDRITIC GROWTH ZONE...SNOW SHOWERS AND FLURRIES SHOULD START
TO BECOME A BIT MORE COMMON TOWARD MIDNIGHT. THIS WILL BE
PARTICULARLY TRUE ALONG AND NORTH OF I-80 AS WELL AS IN THE RIDGES
AS THE NORTHWESTERLY FLOW BECOMES MORE FAVORABLE FOR SUCH
DEVELOPMENT. FLURRIES WILL BE POSSIBLE ANYWHERE IN THE CWA OWING
TO THE AIR MASS CHANGE AND STILL STRONG ADVECTION WITH UNSTABLE
BOUNDARY LAYER...HOWEVER THE BEST CHANCES WILL BE UP NORTH AND IN
THE RIDGES. ACCUMULATIONS ANYWHERE SHOULD BE FAIRLY MINIMAL AS
SHALLOW MOISTURE AND POOR LIFT ALONG WITH SOME DEGREE OF RIMING
SHOULD YIELD POOR QPF AND NO BETTER THAN CLIMO SNOW TO LIQUID
RATIOS. AS A RESULT...EVEN IN THE FAVORED AREAS...REALLY ONLY
ABOVE A HALF AN INCH OF SNOW IS EXPECTED OVERNIGHT. FRIES

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FAST MOVING SHORTWAVE WILL KEEP CLOUDS AND A FEW SNOW SHOWERS
MAINLY ACROSS THE NORTH THURSDAY NIGHT...ENDING EARLY FRIDAY AS
SURFACE RIDGE NOSES INTO THE REGION. WEAK SOUTHERN STREAM SYSTEM
WILL APPROACH LATE SATURDAY WITH CHC POPS ACROSS THE FAR SOUTH FOR
LIGHT SNOW. BULK OF MOISTURE WITH THIS SYSTEM WILL REMAIN WELL
SOUTH OF THE REGION AS IT QUICKLY SHIFTS EAST BY EARLY SUNDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. DRY ADVCTN MAY SPPRT
A RISE IN CLD BASES AT SRN TERMINALS THIS AFTN...BUT MVFR
REDVLPMNT IS ANTICIPATED WITH THE PASSING OF A COLD REINFORCING
SHRTWV THIS EVE.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS
ON SATURDAY IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO
INTIATE ANOTHER ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$







000
FXUS61 KPBZ 172301
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
601 PM EST WED DEC 17 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...
COLD ADVECTION IS WELL UNDERWAY ACROSS THE CWA...AND AS FLOW
TRENDS MORE TOWARD THE NORTHWEST OVERNIGHT WITH THE LOW LEVEL
UNSTABLE MOIST LAYER BEGINNING TO INTERSECT THE LOWER PORTION OF
THE DENDRITIC GROWTH ZONE...SNOW SHOWERS AND FLURRIES SHOULD START
TO BECOME A BIT MORE COMMON TOWARD MIDNIGHT. THIS WILL BE
PARTICULARLY TRUE ALONG AND NORTH OF I-80 AS WELL AS IN THE RIDGES
AS THE NORTHWESTERLY FLOW BECOMES MORE FAVORABLE FOR SUCH
DEVELOPMENT. FLURRIES WILL BE POSSIBLE ANYWHERE IN THE CWA OWING
TO THE AIR MASS CHANGE AND STILL STRONG ADVECTION WITH UNSTABLE
BOUNDARY LAYER...HOWEVER THE BEST CHANCES WILL BE UP NORTH AND IN
THE RIDGES. ACCUMULATIONS ANYWHERE SHOULD BE FAIRLY MINIMAL AS
SHALLOW MOISTURE AND POOR LIFT ALONG WITH SOME DEGREE OF RIMING
SHOULD YIELD POOR QPF AND NO BETTER THAN CLIMO SNOW TO LIQUID
RATIOS. AS A RESULT...EVEN IN THE FAVORED AREAS...REALLY ONLY
ABOVE A HALF AN INCH OF SNOW IS EXPECTED OVERNIGHT. FRIES

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FAST MOVING SHORTWAVE WILL KEEP CLOUDS AND A FEW SNOW SHOWERS
MAINLY ACROSS THE NORTH THURSDAY NIGHT...ENDING EARLY FRIDAY AS
SURFACE RIDGE NOSES INTO THE REGION. WEAK SOUTHERN STREAM SYSTEM
WILL APPROACH LATE SATURDAY WITH CHC POPS ACROSS THE FAR SOUTH FOR
LIGHT SNOW. BULK OF MOISTURE WITH THIS SYSTEM WILL REMAIN WELL
SOUTH OF THE REGION AS IT QUICKLY SHIFTS EAST BY EARLY SUNDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. DRY ADVCTN MAY SPPRT
A RISE IN CLD BASES AT SRN TERMINALS THIS AFTN...BUT MVFR
REDVLPMNT IS ANTICIPATED WITH THE PASSING OF A COLD REINFORCING
SHRTWV THIS EVE.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS
ON SATURDAY IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO
INTIATE ANOTHER ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$








000
FXUS61 KPBZ 171958
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
258 PM EST WED DEC 17 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...
COLDER AND DRIER AIR CONTINUES TO WORK INTO THE REGION WITH SNOW
SHOWERS NOW CONFINED TO THE I-80 CORRIDOR. AS 850MB TEMPS FALL
TONIGHT SNOW SHOWERS MAINLY NORTH OF I-80 EXPECTED TO BRING AN
INCH OR LESS. ELSEWHERE LOW INVERSION HEIGHT AND LACK OF
SIGNIFICANT MOISTURE SHOULD KEEP REMAINDER OF THE REGION MAINLY PRECIP
FREE. WESTERLY FLOW WILL KEEP SNOW SHOWERS ACROSS THE NORTH
THURSDAY BUT WITH CONTINUED LOW INVERSIONS LITTLE IN THE WAY OF
ACCUMULATION EXPECTED.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FAST MOVING SHORTWAVE WILL KEEP CLOUDS AND A FEW SNOW SHOWERS
MAINLY ACROSS THE NORTH THURSDAY NIGHT...ENDING EARLY FRIDAY AS
SURFACE RIDGE NOSES INTO THE REGION. WEAK SOUTHERN STREAM SYSTEM
WILL APPROACH LATE SATURDAY WITH CHC POPS ACROSS THE FAR SOUTH FOR
LIGHT SNOW. BULK OF MOISTURE WITH THIS SYSTEM WILL REMAIN WELL
SOUTH OF THE REGION AS IT QUICKLY SHIFTS EAST BY EARLY SUNDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. DRY ADVCTN MAY SPPRT
A RISE IN CLD BASES AT SRN TERMINALS THIS AFTN...BUT MVFR
REDVLPMNT IS ANTICIPATED WITH THE PASSING OF A COLD REINFORCING
SHRTWV THIS EVE.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS
ON SATURDAY IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO
INTIATE ANOTHER ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$












000
FXUS61 KPBZ 171958
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
258 PM EST WED DEC 17 2014

.SYNOPSIS...
IT WILL BE CLOUDY WITH NEAR SEASONAL TEMPERATURES THROUGH THE END
OF THE WEEK.

&&

.NEAR TERM /THROUGH THURSDAY/...
COLDER AND DRIER AIR CONTINUES TO WORK INTO THE REGION WITH SNOW
SHOWERS NOW CONFINED TO THE I-80 CORRIDOR. AS 850MB TEMPS FALL
TONIGHT SNOW SHOWERS MAINLY NORTH OF I-80 EXPECTED TO BRING AN
INCH OR LESS. ELSEWHERE LOW INVERSION HEIGHT AND LACK OF
SIGNIFICANT MOISTURE SHOULD KEEP REMAINDER OF THE REGION MAINLY PRECIP
FREE. WESTERLY FLOW WILL KEEP SNOW SHOWERS ACROSS THE NORTH
THURSDAY BUT WITH CONTINUED LOW INVERSIONS LITTLE IN THE WAY OF
ACCUMULATION EXPECTED.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FAST MOVING SHORTWAVE WILL KEEP CLOUDS AND A FEW SNOW SHOWERS
MAINLY ACROSS THE NORTH THURSDAY NIGHT...ENDING EARLY FRIDAY AS
SURFACE RIDGE NOSES INTO THE REGION. WEAK SOUTHERN STREAM SYSTEM
WILL APPROACH LATE SATURDAY WITH CHC POPS ACROSS THE FAR SOUTH FOR
LIGHT SNOW. BULK OF MOISTURE WITH THIS SYSTEM WILL REMAIN WELL
SOUTH OF THE REGION AS IT QUICKLY SHIFTS EAST BY EARLY SUNDAY.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. DRY ADVCTN MAY SPPRT
A RISE IN CLD BASES AT SRN TERMINALS THIS AFTN...BUT MVFR
REDVLPMNT IS ANTICIPATED WITH THE PASSING OF A COLD REINFORCING
SHRTWV THIS EVE.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS
ON SATURDAY IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO
INTIATE ANOTHER ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$











000
FXUS61 KPBZ 171622
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1122 AM EST WED DEC 17 2014

.SYNOPSIS...
COLDER AIR MOVING IN FROM THE WEST WILL KEEP HIGH TEMPERATURES
TODAY LOW. CLOUDS WILL REMAIN IN THE AREA THROUGH MID-WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
LITTLE CHANGE TO PREVIOUS FORECAST FOR THE AFTERNOON UPDATE. LIGHT SNOW
SHOWERS DIMINISHING WEST TO EAST AS DRIER LOW LEVEL AIR WORKS
INTO REGION.

AS COLD ADVECTION CONTINUES AT 850MB THROUGH THE DAY TEMPERATURES
WILL CONTINUE TO FALL. PRECIP IS NOW ALMOST ALL SNOW AND HAVE
ADJUSTED GRIDS. WANING MOISTURE IN THE COLUMN WILL KEEP SNOW
SHOWERS LIGHT. TONIGHT AS SHORTWAVE PASSES FLOW WILL TURN A BIT
NORTHWEST TOWARD MIDNIGHT ALLOWING FOR SNOW SHOWERS MAINLY ACROSS
THE I-80 CORRIDOR WITH ONLY LIGHT ACCUMULATION. RELATIVELY DRY LOW
LEVELS WILL KEEP REMAINDER OF REGION DRY.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
PERSISTENCE WILL BE THE THEME OF THE SHORT TERM FORECAST AS SNOW
CHANCES WILL HOLD ACROSS THE NORTH AND CLOUDS WILL BE EVER-PRESENT. LLVL
CLOUDS EXPECTED TO LAST THROUGH THE SHORT TERM AS A MID-LEVEL
INVERSION TRAPS THE MOISTURE BELOW...SIMILAR TO WHAT WAS SEEN LATE
LAST WEEK. AS THE GREAT LAKES SFC LOW TRANSITIONS TO A DEEPENING LOW
OVER THE THE NEW ENGLAND COASTLINE ...MID-LEVEL FLOW VEERS TO THE
NW SUPPORTING ADDITIONAL LLVL MOISTURE INJECTION FROM THE UPSTREAM
GREAT LAKES. KEEPING AT LEAST A CHC OF SNOW SHOWERS ACROSS THE
NORTH THURS AS LAKE MOISTURE IS SQUEEZED OUT OVER OUR NRN TIER OF
COUNTIES. SHOWERS MAY DWINDLE AT TIMES THROUGH THE EVENING
HOURS...BUT ARE EXPECTED TO RE-INVIGORATE DURING THE OVERNIGHT
HOURS INTO EARLY FRI MORNING AS ANOTHER WEAK SW STREAMS THROUGH.

OUTSIDE OF THE LAKE EFFECT AREAS...PRECIPITATION SHOULD LARGELY REMAIN
OUT OF THE FORECAST WITH INSUFFICIENT MOISTURE PROGGED. MODELS
HAVE HINTED AT A WEAK WAVE CROSSING OUR SRN ZONES EARLY FRI
MORNING...WITH THE 00Z NAM BULLISH ON THIS FEATURE. DECIDED TO
HANG WITH ALL OF THE OTHER GUIDANCE WHICH KEEPS THE SOUTH AND WEST
ZONES DRY...BUT CLOUDY.
TAX

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. DRY ADVCTN MAY SPPRT
A RISE IN CLD BASES AT SRN TERMINALS THIS AFTN...BUT MVFR
REDVLPMNT IS ANTICIPATED WITH THE PASSING OF A COLD REINFORCING
SHRTWV THIS EVE.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS
ON SATURDAY IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO
INTIATE ANOTHER ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$









000
FXUS61 KPBZ 171622
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1122 AM EST WED DEC 17 2014

.SYNOPSIS...
COLDER AIR MOVING IN FROM THE WEST WILL KEEP HIGH TEMPERATURES
TODAY LOW. CLOUDS WILL REMAIN IN THE AREA THROUGH MID-WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
LITTLE CHANGE TO PREVIOUS FORECAST FOR THE AFTERNOON UPDATE. LIGHT SNOW
SHOWERS DIMINISHING WEST TO EAST AS DRIER LOW LEVEL AIR WORKS
INTO REGION.

AS COLD ADVECTION CONTINUES AT 850MB THROUGH THE DAY TEMPERATURES
WILL CONTINUE TO FALL. PRECIP IS NOW ALMOST ALL SNOW AND HAVE
ADJUSTED GRIDS. WANING MOISTURE IN THE COLUMN WILL KEEP SNOW
SHOWERS LIGHT. TONIGHT AS SHORTWAVE PASSES FLOW WILL TURN A BIT
NORTHWEST TOWARD MIDNIGHT ALLOWING FOR SNOW SHOWERS MAINLY ACROSS
THE I-80 CORRIDOR WITH ONLY LIGHT ACCUMULATION. RELATIVELY DRY LOW
LEVELS WILL KEEP REMAINDER OF REGION DRY.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
PERSISTENCE WILL BE THE THEME OF THE SHORT TERM FORECAST AS SNOW
CHANCES WILL HOLD ACROSS THE NORTH AND CLOUDS WILL BE EVER-PRESENT. LLVL
CLOUDS EXPECTED TO LAST THROUGH THE SHORT TERM AS A MID-LEVEL
INVERSION TRAPS THE MOISTURE BELOW...SIMILAR TO WHAT WAS SEEN LATE
LAST WEEK. AS THE GREAT LAKES SFC LOW TRANSITIONS TO A DEEPENING LOW
OVER THE THE NEW ENGLAND COASTLINE ...MID-LEVEL FLOW VEERS TO THE
NW SUPPORTING ADDITIONAL LLVL MOISTURE INJECTION FROM THE UPSTREAM
GREAT LAKES. KEEPING AT LEAST A CHC OF SNOW SHOWERS ACROSS THE
NORTH THURS AS LAKE MOISTURE IS SQUEEZED OUT OVER OUR NRN TIER OF
COUNTIES. SHOWERS MAY DWINDLE AT TIMES THROUGH THE EVENING
HOURS...BUT ARE EXPECTED TO RE-INVIGORATE DURING THE OVERNIGHT
HOURS INTO EARLY FRI MORNING AS ANOTHER WEAK SW STREAMS THROUGH.

OUTSIDE OF THE LAKE EFFECT AREAS...PRECIPITATION SHOULD LARGELY REMAIN
OUT OF THE FORECAST WITH INSUFFICIENT MOISTURE PROGGED. MODELS
HAVE HINTED AT A WEAK WAVE CROSSING OUR SRN ZONES EARLY FRI
MORNING...WITH THE 00Z NAM BULLISH ON THIS FEATURE. DECIDED TO
HANG WITH ALL OF THE OTHER GUIDANCE WHICH KEEPS THE SOUTH AND WEST
ZONES DRY...BUT CLOUDY.
TAX

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. DRY ADVCTN MAY SPPRT
A RISE IN CLD BASES AT SRN TERMINALS THIS AFTN...BUT MVFR
REDVLPMNT IS ANTICIPATED WITH THE PASSING OF A COLD REINFORCING
SHRTWV THIS EVE.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS
ON SATURDAY IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO
INTIATE ANOTHER ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$










000
FXUS61 KPBZ 171428
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
928 AM EST WED DEC 17 2014

.SYNOPSIS...
COLDER AIR MOVING IN FROM THE WEST WILL KEEP HIGH TEMPERATURES
TODAY LOW. CLOUDS WILL REMAIN IN THE AREA THROUGH MID-WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS COLD ADVECTION CONTINUES AT 850MB THROUGH THE DAY TEMPERATURES
WILL CONTINUE TO FALL. PRECIP IS NOW ALMOST ALL SNOW AND HAVE
ADJUSTED GRIDS. WANING MOISTURE IN THE COLUMN WILL KEEP SNOW
SHOWERS LIGHT. TONIGHT AS SHORTWAVE PASSES FLOW WILL TURN A BIT
NORTHWEST TOWARD MIDNIGHT ALLOWING FOR SNOW SHOWERS MAINLY ACROSS
THE I-80 CORRIDOR WITH ONLY LIGHT ACCUMULATION. RELATIVELY DRY LOW
LEVELS WILL KEEP REMAINDER OF REGION DRY.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
PERSISTENCE WILL BE THE THEME OF THE SHORT TERM FORECAST AS SNOW
CHANCES WILL HOLD ACROSS THE NORTH AND CLOUDS WILL BE EVER-PRESENT. LLVL
CLOUDS EXPECTED TO LAST THROUGH THE SHORT TERM AS A MID-LEVEL
INVERSION TRAPS THE MOISTURE BELOW...SIMILAR TO WHAT WAS SEEN LATE
LAST WEEK. AS THE GREAT LAKES SFC LOW TRANSITIONS TO A DEEPENING LOW
OVER THE THE NEW ENGLAND COASTLINE ...MID-LEVEL FLOW VEERS TO THE
NW SUPPORTING ADDITIONAL LLVL MOISTURE INJECTION FROM THE UPSTREAM
GREAT LAKES. KEEPING AT LEAST A CHC OF SNOW SHOWERS ACROSS THE
NORTH THURS AS LAKE MOISTURE IS SQUEEZED OUT OVER OUR NRN TIER OF
COUNTIES. SHOWERS MAY DWINDLE AT TIMES THROUGH THE EVENING
HOURS...BUT ARE EXPECTED TO RE-INVIGORATE DURING THE OVERNIGHT
HOURS INTO EARLY FRI MORNING AS ANOTHER WEAK SW STREAMS THROUGH.

OUTSIDE OF THE LAKE EFFECT AREAS...PRECIPITATION SHOULD LARGELY REMAIN
OUT OF THE FORECAST WITH INSUFFICIENT MOISTURE PROGGED. MODELS
HAVE HINTED AT A WEAK WAVE CROSSING OUR SRN ZONES EARLY FRI
MORNING...WITH THE 00Z NAM BULLISH ON THIS FEATURE. DECIDED TO
HANG WITH ALL OF THE OTHER GUIDANCE WHICH KEEPS THE SOUTH AND WEST
ZONES DRY...BUT CLOUDY.
TAX

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. DRY ADVCTN MAY SPPRT
A RISE IN CLD BASES AT SRN TERMINALS THIS AFTN...BUT MVFR
REDVLPMNT IS ANTICIPATED WITH THE PASSING OF A COLD REINFORCING
SHRTWV THIS EVE.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS
ON SATURDAY IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO
INTIATE ANOTHER ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$










000
FXUS61 KPBZ 171428
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
928 AM EST WED DEC 17 2014

.SYNOPSIS...
COLDER AIR MOVING IN FROM THE WEST WILL KEEP HIGH TEMPERATURES
TODAY LOW. CLOUDS WILL REMAIN IN THE AREA THROUGH MID-WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS COLD ADVECTION CONTINUES AT 850MB THROUGH THE DAY TEMPERATURES
WILL CONTINUE TO FALL. PRECIP IS NOW ALMOST ALL SNOW AND HAVE
ADJUSTED GRIDS. WANING MOISTURE IN THE COLUMN WILL KEEP SNOW
SHOWERS LIGHT. TONIGHT AS SHORTWAVE PASSES FLOW WILL TURN A BIT
NORTHWEST TOWARD MIDNIGHT ALLOWING FOR SNOW SHOWERS MAINLY ACROSS
THE I-80 CORRIDOR WITH ONLY LIGHT ACCUMULATION. RELATIVELY DRY LOW
LEVELS WILL KEEP REMAINDER OF REGION DRY.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
PERSISTENCE WILL BE THE THEME OF THE SHORT TERM FORECAST AS SNOW
CHANCES WILL HOLD ACROSS THE NORTH AND CLOUDS WILL BE EVER-PRESENT. LLVL
CLOUDS EXPECTED TO LAST THROUGH THE SHORT TERM AS A MID-LEVEL
INVERSION TRAPS THE MOISTURE BELOW...SIMILAR TO WHAT WAS SEEN LATE
LAST WEEK. AS THE GREAT LAKES SFC LOW TRANSITIONS TO A DEEPENING LOW
OVER THE THE NEW ENGLAND COASTLINE ...MID-LEVEL FLOW VEERS TO THE
NW SUPPORTING ADDITIONAL LLVL MOISTURE INJECTION FROM THE UPSTREAM
GREAT LAKES. KEEPING AT LEAST A CHC OF SNOW SHOWERS ACROSS THE
NORTH THURS AS LAKE MOISTURE IS SQUEEZED OUT OVER OUR NRN TIER OF
COUNTIES. SHOWERS MAY DWINDLE AT TIMES THROUGH THE EVENING
HOURS...BUT ARE EXPECTED TO RE-INVIGORATE DURING THE OVERNIGHT
HOURS INTO EARLY FRI MORNING AS ANOTHER WEAK SW STREAMS THROUGH.

OUTSIDE OF THE LAKE EFFECT AREAS...PRECIPITATION SHOULD LARGELY REMAIN
OUT OF THE FORECAST WITH INSUFFICIENT MOISTURE PROGGED. MODELS
HAVE HINTED AT A WEAK WAVE CROSSING OUR SRN ZONES EARLY FRI
MORNING...WITH THE 00Z NAM BULLISH ON THIS FEATURE. DECIDED TO
HANG WITH ALL OF THE OTHER GUIDANCE WHICH KEEPS THE SOUTH AND WEST
ZONES DRY...BUT CLOUDY.
TAX

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PD IS PROGGED TO FEATURE REDVLPMNT OF HIGHER
AMPLITUDE FLOW OVR THE CONUS AS A TROF DIGS OVR THE PLNS AND
DEEPENS EWD. INITIAL SEASONAL TEMPS FOR THE UPR OH REGION ARE THUS
EXPECTED TO MODERATE AS WARM ADVCTN INTENSIFIES ON THE ERN FLANK
OF THAT SYSTEM. LATE PD POP TRENDS WL BE DEPENDANT ON PLACEMENT
AND PROGRESS OF THE MID/UPR LOW CNTR...VERY QNABLE GIVEN THE
CUTOFF CURRENTLY FORECAST BY MODEL WORLD. IN GENL...WPC GUIDANCE
WAS USED WITH TWEAKS FOR COLLABORATIVE THRESHOLDS.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
GENL MVFR...AND PERIODIC IFR FOR NRN PORTS...CAN BE EXPECTED FOR
THE TAF PD AS STRATOCU BLANKET IS MAINTAINED OVR THE UPR OH REGION
VIA COLD ADVCTN AT THE TOP OF THE BNDRY LYR. DRY ADVCTN MAY SPPRT
A RISE IN CLD BASES AT SRN TERMINALS THIS AFTN...BUT MVFR
REDVLPMNT IS ANTICIPATED WITH THE PASSING OF A COLD REINFORCING
SHRTWV THIS EVE.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS ARE EXPECTED UNTIL BNDRY LYR FLOW BACKS
ON SATURDAY IN ADVN OF LOW PRES. THAT SYSTEM IS FORECAST TO
INTIATE ANOTHER ROUND OF GENL RESTRICTIONS BY SATURDAY NGT.

&&

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

&&

$$









000
FXUS61 KPBZ 171146
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
646 AM EST WED DEC 17 2014

.SYNOPSIS...
COLDER AIR MOVING IN FROM THE WEST WILL KEEP HIGH TEMPERATURES
TODAY LOW. CLOUDS WILL REMAIN IN THE AREA THROUGH MID-WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
CURRENT RADAR IMAGERY CONTINUES TO SHOW SCATTERED WEAK ECHOES
INDICATING LIGHT RAIN SHOWERS WITH SOME PATCHY DRIZZLE. THE BULK
OF THE REMAINING SHOWERS SHOULD REMAIN LIGHT...AS MOISTURE ABOVE
H85 BEGINS TO DRY UP. NOW THROUGH 15Z...BEFORE H85 CAA KNOCKS
TEMPS DOWN TO ENOUGH TO GENERATE ICE CRYSTALS...DRIZZLE LOOKS TO
BE QUITE FAVORABLE. MENTIONED PATCHY DRIZZLE THIS MORNING ACROSS
THE SRN 2/3 OF THE CWA. FURTHER NORTH...THE DEEPER MOISTURE LOOKS
TO HOLD THROUGH MIDDAY...SO HELD DZ/FZDZ OUT ALONG I-80. IN THE
HIGHER ELEVATIONS IN THE RIDGES...TEMPS COULD DROP OFF ENOUGH TO
SEE SOME LIGHT PATCHY FZDZ...BUT NOT EXPECTING WIDESPREAD OR
APPRECIABLE ICING.

COLDER AIR WILL CONTINUE TO INVADE THROUGH THE MORNING WITH SFC
TEMPS FOLLOWING A NON-DIURNAL TREND. LATEST HRRR/LAMP HANDLE THE
COLD AIR PROGRESSION WELL. OPTED FOR A BLEND OF THESE THROUGH
MIDDAY...FAVORING THE MET BEYOND THAT PERIOD. TEMPS REGISTERED EARLY THIS
MORNING SHOULD LARGELY STAND AS THE HIGH TEMPS TODAY. 00Z NAM
SOUNDINGS CONTINUE TO LOOK EERILY SIMILAR TO LAST THURS/FRI WHERE
MOISTURE GETS TRAPPED UNDER AN H85 INVERSION AND IS UNABLE TO
DISLODGE FOR SOME TIME.

TONIGHT THE BULK OF THE DEEP MOISTURE EXITS NORTH AS A STRONG JET
TURNS THE FLOW MORE ZONAL. HI-RES NEAR TERM MODELS INDICATING A
DEEPENING OF THE BL MOISTURE DUE TO INJECTION OF LAKE MOISTURE NOT
FROM LAKE ERIE...BUT FROM THE SRN END OF LAKE MICHIGAN. MOISTURE
UP TO H8 SHOULD BE ENOUGH TO GENERATE SNOW SHOWERS TONIGHT ACROSS
THE I-80 CORRIDOR AND NORTH...ESPECIALLY AS ENHANCED COOLING IN
THE MID-LEVELS BRINGS THE SNOW GROWTH ZONE LOW ENOUGH TO OVERLAP
THE TOP OF THE MOISTURE. STILL...OVERALL MOISTURE IS LIMITED
ULTIMATELY KEEPING ANY SNOW ACCUMULATION LIGHT.
TAX

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
PERSISTENCE WILL BE THE THEME OF THE SHORT TERM FORECAST AS SNOW
CHANCES WILL HOLD ACROSS THE NORTH AND CLOUDS WILL BE EVER-PRESENT. LLVL
CLOUDS EXPECTED TO LAST THROUGH THE SHORT TERM AS A MID-LEVEL
INVERSION TRAPS THE MOISTURE BELOW...SIMILAR TO WHAT WAS SEEN LATE
LAST WEEK. AS THE GREAT LAKES SFC LOW TRANSITIONS TO A DEEPENING LOW
OVER THE THE NEW ENGLAND COASTLINE ...MID-LEVEL FLOW VEERS TO THE
NW SUPPORTING ADDITIONAL LLVL MOISTURE INJECTION FROM THE UPSTREAM
GREAT LAKES. KEEPING AT LEAST A CHC OF SNOW SHOWERS ACROSS THE
NORTH THURS AS LAKE MOISTURE IS SQUEEZED OUT OVER OUR NRN TIER OF
COUNTIES. SHOWERS MAY DWINDLE AT TIMES THROUGH THE EVENING
HOURS...BUT ARE EXPECTED TO RE-INVIGORATE DURING THE OVERNIGHT
HOURS INTO EARLY FRI MORNING AS ANOTHER WEAK SW STREAMS THROUGH.

OUTSIDE OF THE LAKE EFFECT AREAS...PRECIPITATION SHOULD LARGELY REMAIN
OUT OF THE FORECAST WITH INSUFFICIENT MOISTURE PROGGED. MODELS
HAVE HINTED AT A WEAK WAVE CROSSING OUR SRN ZONES EARLY FRI
MORNING...WITH THE 00Z NAM BULLISH ON THIS FEATURE. DECIDED TO
HANG WITH ALL OF THE OTHER GUIDANCE WHICH KEEPS THE SOUTH AND WEST
ZONES DRY...BUT CLOUDY.
TAX

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
A SOUTHERN STREAM MID-LEVEL TROUGH WILL QUICKLY MIGRATE EAST AND
BRUSH ACROSS THE SOUTHERN EDGE OF THE FORECAST AREA ON SATURDAY
WITH THE BEST CHANCES OF ANY PRECIPITATION ON SATURDAY EVENING AND
OVERNIGHT ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST
AREA. ANY PRECIP SHOULD FALL IN THE FORM OF SNOW...BUT OVERALL
AMOUNTS WILL BE LIGHT AS FORCING LOOKS TO BE RELATIVELY WEAK AND
IN TEMPERATURES NOT FAVORABLE FOR SIGNIFICANT SNOW GROWTH. DRY
CONDITIONS THEN EXPECTED SUNDAY AFTERNOON AND INTO THE BEGINNING
OF NEXT WEEK AS THE LONGWAVE PATTERN AMPLIFIES AND AN UPPER TROUGH
DEEPENS ACROSS THE EASTERN CONUS. MODELS HAVE SHOWN DECENT
CONTINUITY WITH THIS FEATURE AND ANTICIPATE ABOVE NORMAL
TEMPERATURES DURING THE FIRST HALF OF NEXT WEEK AS WAA RAMPS UP
AHEAD OF THE TROUGH UNDER STRENGTHENING SOUTHWESTERLY FLOW. HAVE
OPTED TO KEEP THE FORECAST DRY THROUGH EARLY TUESDAY EVENING AND
INCREASE TEMPERATURES BOTH MONDAY AND TUESDAY FOR NOW BASED ON THE
LATEST BLEND OF THE EC AND GEFS...AND AN OVERALL RUN TO RUN TREND
AMONG MODELS IN SHOWING A DEEPER/SLOWER SOLUTION. 24HR QPF AMOUNTS
AT THIS TIME BETWEEN MODELS FOR THE MIDDLE OF NEXT WEEK RANGE
BETWEEN ONE HALF AND THREE QUARTERS OF AN INCH.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
PERIODIC IFR CIG RESTRICTIONS NOT OUT OF THE QUESTION...BUT AREA
PORTS SOUTH OF INTERSTATE 80 SHOULD LARGELY SEE LOW MVFR CIG
RESTRICTIONS OVER THE COURSE OF THE MORNING AS PRECIPITATION
DIMINISHES FROM WEST TO EAST. WINDS WILL REMAIN GUSTY DURING THE
DAY AFTER A REINFORCING SHOT OF COLD AIR MOVES THROUGH LATE THIS
MORNING/EARLY AFTERNOON. GUIDANCE CONTINUES TO MAINTAIN THE HIGH
MVFR/LOW VFR STRATOCU FORECAST DURING THE AFTERNOON WITH TRAPPED
LOW LEVEL MOISTURE AND CONTINUED CAA. MAIN CONCERN IS THE
POSSIBILITY OF FREEZING DRIZZLE AFTER TEMPERATURES FALL TO BELOW
FREEZING THROUGHOUT THE COLUMN THIS AFTERNOON ACROSS THE NORTH AND
LATE AFTERNOON/EARLY EVENING ACROSS SOUTHERN LOCATIONS...COUPLED
WITH THE POTENTIAL THAT MOISTURE MAY NOT BE DEEP/HIGH ENOUGH FOR
ICE CRYSTAL DEVELOPMENT ALOFT. FOR NOW HAVE OPTED TO REFRAIN FROM
ANY MENTION OF PRECIPITATION DURING THE DAY AS ANY PRECIP WOULD
LIKELY BE LIGHT FLURRIES MAINLY FOR KFKL AND KDUJ...BUT MAY NEED
TO INCLUDE MENTION OF FREEZING DRIZZLE WITH THE 12Z TAF SUITE
AFTER ASSESSMENT OF MORNING SOUNDINGS.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS EXPECTED THROUGHOUT THE WEEK WITH
TRAPPED LOW LEVEL MOISTURE AND CONTINUED CAA MAINTAINING STRATOCU
IN THE LOWER LEVELS.

&&

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

&&

$$








000
FXUS61 KPBZ 171146
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
646 AM EST WED DEC 17 2014

.SYNOPSIS...
COLDER AIR MOVING IN FROM THE WEST WILL KEEP HIGH TEMPERATURES
TODAY LOW. CLOUDS WILL REMAIN IN THE AREA THROUGH MID-WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
CURRENT RADAR IMAGERY CONTINUES TO SHOW SCATTERED WEAK ECHOES
INDICATING LIGHT RAIN SHOWERS WITH SOME PATCHY DRIZZLE. THE BULK
OF THE REMAINING SHOWERS SHOULD REMAIN LIGHT...AS MOISTURE ABOVE
H85 BEGINS TO DRY UP. NOW THROUGH 15Z...BEFORE H85 CAA KNOCKS
TEMPS DOWN TO ENOUGH TO GENERATE ICE CRYSTALS...DRIZZLE LOOKS TO
BE QUITE FAVORABLE. MENTIONED PATCHY DRIZZLE THIS MORNING ACROSS
THE SRN 2/3 OF THE CWA. FURTHER NORTH...THE DEEPER MOISTURE LOOKS
TO HOLD THROUGH MIDDAY...SO HELD DZ/FZDZ OUT ALONG I-80. IN THE
HIGHER ELEVATIONS IN THE RIDGES...TEMPS COULD DROP OFF ENOUGH TO
SEE SOME LIGHT PATCHY FZDZ...BUT NOT EXPECTING WIDESPREAD OR
APPRECIABLE ICING.

COLDER AIR WILL CONTINUE TO INVADE THROUGH THE MORNING WITH SFC
TEMPS FOLLOWING A NON-DIURNAL TREND. LATEST HRRR/LAMP HANDLE THE
COLD AIR PROGRESSION WELL. OPTED FOR A BLEND OF THESE THROUGH
MIDDAY...FAVORING THE MET BEYOND THAT PERIOD. TEMPS REGISTERED EARLY THIS
MORNING SHOULD LARGELY STAND AS THE HIGH TEMPS TODAY. 00Z NAM
SOUNDINGS CONTINUE TO LOOK EERILY SIMILAR TO LAST THURS/FRI WHERE
MOISTURE GETS TRAPPED UNDER AN H85 INVERSION AND IS UNABLE TO
DISLODGE FOR SOME TIME.

TONIGHT THE BULK OF THE DEEP MOISTURE EXITS NORTH AS A STRONG JET
TURNS THE FLOW MORE ZONAL. HI-RES NEAR TERM MODELS INDICATING A
DEEPENING OF THE BL MOISTURE DUE TO INJECTION OF LAKE MOISTURE NOT
FROM LAKE ERIE...BUT FROM THE SRN END OF LAKE MICHIGAN. MOISTURE
UP TO H8 SHOULD BE ENOUGH TO GENERATE SNOW SHOWERS TONIGHT ACROSS
THE I-80 CORRIDOR AND NORTH...ESPECIALLY AS ENHANCED COOLING IN
THE MID-LEVELS BRINGS THE SNOW GROWTH ZONE LOW ENOUGH TO OVERLAP
THE TOP OF THE MOISTURE. STILL...OVERALL MOISTURE IS LIMITED
ULTIMATELY KEEPING ANY SNOW ACCUMULATION LIGHT.
TAX

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
PERSISTENCE WILL BE THE THEME OF THE SHORT TERM FORECAST AS SNOW
CHANCES WILL HOLD ACROSS THE NORTH AND CLOUDS WILL BE EVER-PRESENT. LLVL
CLOUDS EXPECTED TO LAST THROUGH THE SHORT TERM AS A MID-LEVEL
INVERSION TRAPS THE MOISTURE BELOW...SIMILAR TO WHAT WAS SEEN LATE
LAST WEEK. AS THE GREAT LAKES SFC LOW TRANSITIONS TO A DEEPENING LOW
OVER THE THE NEW ENGLAND COASTLINE ...MID-LEVEL FLOW VEERS TO THE
NW SUPPORTING ADDITIONAL LLVL MOISTURE INJECTION FROM THE UPSTREAM
GREAT LAKES. KEEPING AT LEAST A CHC OF SNOW SHOWERS ACROSS THE
NORTH THURS AS LAKE MOISTURE IS SQUEEZED OUT OVER OUR NRN TIER OF
COUNTIES. SHOWERS MAY DWINDLE AT TIMES THROUGH THE EVENING
HOURS...BUT ARE EXPECTED TO RE-INVIGORATE DURING THE OVERNIGHT
HOURS INTO EARLY FRI MORNING AS ANOTHER WEAK SW STREAMS THROUGH.

OUTSIDE OF THE LAKE EFFECT AREAS...PRECIPITATION SHOULD LARGELY REMAIN
OUT OF THE FORECAST WITH INSUFFICIENT MOISTURE PROGGED. MODELS
HAVE HINTED AT A WEAK WAVE CROSSING OUR SRN ZONES EARLY FRI
MORNING...WITH THE 00Z NAM BULLISH ON THIS FEATURE. DECIDED TO
HANG WITH ALL OF THE OTHER GUIDANCE WHICH KEEPS THE SOUTH AND WEST
ZONES DRY...BUT CLOUDY.
TAX

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
A SOUTHERN STREAM MID-LEVEL TROUGH WILL QUICKLY MIGRATE EAST AND
BRUSH ACROSS THE SOUTHERN EDGE OF THE FORECAST AREA ON SATURDAY
WITH THE BEST CHANCES OF ANY PRECIPITATION ON SATURDAY EVENING AND
OVERNIGHT ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST
AREA. ANY PRECIP SHOULD FALL IN THE FORM OF SNOW...BUT OVERALL
AMOUNTS WILL BE LIGHT AS FORCING LOOKS TO BE RELATIVELY WEAK AND
IN TEMPERATURES NOT FAVORABLE FOR SIGNIFICANT SNOW GROWTH. DRY
CONDITIONS THEN EXPECTED SUNDAY AFTERNOON AND INTO THE BEGINNING
OF NEXT WEEK AS THE LONGWAVE PATTERN AMPLIFIES AND AN UPPER TROUGH
DEEPENS ACROSS THE EASTERN CONUS. MODELS HAVE SHOWN DECENT
CONTINUITY WITH THIS FEATURE AND ANTICIPATE ABOVE NORMAL
TEMPERATURES DURING THE FIRST HALF OF NEXT WEEK AS WAA RAMPS UP
AHEAD OF THE TROUGH UNDER STRENGTHENING SOUTHWESTERLY FLOW. HAVE
OPTED TO KEEP THE FORECAST DRY THROUGH EARLY TUESDAY EVENING AND
INCREASE TEMPERATURES BOTH MONDAY AND TUESDAY FOR NOW BASED ON THE
LATEST BLEND OF THE EC AND GEFS...AND AN OVERALL RUN TO RUN TREND
AMONG MODELS IN SHOWING A DEEPER/SLOWER SOLUTION. 24HR QPF AMOUNTS
AT THIS TIME BETWEEN MODELS FOR THE MIDDLE OF NEXT WEEK RANGE
BETWEEN ONE HALF AND THREE QUARTERS OF AN INCH.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
PERIODIC IFR CIG RESTRICTIONS NOT OUT OF THE QUESTION...BUT AREA
PORTS SOUTH OF INTERSTATE 80 SHOULD LARGELY SEE LOW MVFR CIG
RESTRICTIONS OVER THE COURSE OF THE MORNING AS PRECIPITATION
DIMINISHES FROM WEST TO EAST. WINDS WILL REMAIN GUSTY DURING THE
DAY AFTER A REINFORCING SHOT OF COLD AIR MOVES THROUGH LATE THIS
MORNING/EARLY AFTERNOON. GUIDANCE CONTINUES TO MAINTAIN THE HIGH
MVFR/LOW VFR STRATOCU FORECAST DURING THE AFTERNOON WITH TRAPPED
LOW LEVEL MOISTURE AND CONTINUED CAA. MAIN CONCERN IS THE
POSSIBILITY OF FREEZING DRIZZLE AFTER TEMPERATURES FALL TO BELOW
FREEZING THROUGHOUT THE COLUMN THIS AFTERNOON ACROSS THE NORTH AND
LATE AFTERNOON/EARLY EVENING ACROSS SOUTHERN LOCATIONS...COUPLED
WITH THE POTENTIAL THAT MOISTURE MAY NOT BE DEEP/HIGH ENOUGH FOR
ICE CRYSTAL DEVELOPMENT ALOFT. FOR NOW HAVE OPTED TO REFRAIN FROM
ANY MENTION OF PRECIPITATION DURING THE DAY AS ANY PRECIP WOULD
LIKELY BE LIGHT FLURRIES MAINLY FOR KFKL AND KDUJ...BUT MAY NEED
TO INCLUDE MENTION OF FREEZING DRIZZLE WITH THE 12Z TAF SUITE
AFTER ASSESSMENT OF MORNING SOUNDINGS.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS EXPECTED THROUGHOUT THE WEEK WITH
TRAPPED LOW LEVEL MOISTURE AND CONTINUED CAA MAINTAINING STRATOCU
IN THE LOWER LEVELS.

&&

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

&&

$$







000
FXUS61 KPBZ 170952
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
452 AM EST WED DEC 17 2014

.SYNOPSIS...
COLDER AIR MOVING IN FROM THE WEST WILL KEEP HIGH TEMPERATURES
TODAY LOW. CLOUDS WILL REMAIN IN THE AREA THROUGH MID-WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
CURRENT RADAR IMAGERY CONTINUES TO SHOW SCATTERED WEAK ECHOES
INDICATING LIGHT RAIN SHOWERS WITH SOME PATCHY DRIZZLE. THE BULK
OF THE REMAINING SHOWERS SHOULD REMAIN LIGHT...AS MOISTURE ABOVE
H85 BEGINS TO DRY UP. NOW THROUGH 15Z...BEFORE H85 CAA KNOCKS
TEMPS DOWN TO ENOUGH TO GENERATE ICE CRYSTALS...DRIZZLE LOOKS TO
BE QUITE FAVORABLE. MENTIONED PATCHY DRIZZLE THIS MORNING ACROSS
THE SRN 2/3 OF THE CWA. FURTHER NORTH...THE DEEPER MOISTURE LOOKS
TO HOLD THROUGH MIDDAY...SO HELD DZ/FZDZ OUT ALONG I-80. IN THE
HIGHER ELEVATIONS IN THE RIDGES...TEMPS COULD DROP OFF ENOUGH TO
SEE SOME LIGHT PATCHY FZDZ...BUT NOT EXPECTING WIDESPREAD OR
APPRECIABLE ICING.

COLDER AIR WILL CONTINUE TO INVADE THROUGH THE MORNING WITH SFC
TEMPS FOLLOWING A NON-DIURNAL TREND. LATEST HRRR/LAMP HANDLE THE
COLD AIR PROGRESSION WELL. OPTED FOR A BLEND OF THESE THROUGH
MIDDAY...FAVORING THE MET BEYOND THAT PERIOD. TEMPS REGISTERED EARLY THIS
MORNING SHOULD LARGELY STAND AS THE HIGH TEMPS TODAY. 00Z NAM
SOUNDINGS CONTINUE TO LOOK EERILY SIMILAR TO LAST THURS/FRI WHERE
MOISTURE GETS TRAPPED UNDER AN H85 INVERSION AND IS UNABLE TO
DISLODGE FOR SOME TIME.

TONIGHT THE BULK OF THE DEEP MOISTURE EXITS NORTH AS A STRONG JET
TURNS THE FLOW MORE ZONAL. HI-RES NEAR TERM MODELS INDICATING A
DEEPENING OF THE BL MOISTURE DUE TO INJECTION OF LAKE MOISTURE NOT
FROM LAKE ERIE...BUT FROM THE SRN END OF LAKE MICHIGAN. MOISTURE
UP TO H8 SHOULD BE ENOUGH TO GENERATE SNOW SHOWERS TONIGHT ACROSS
THE I-80 CORRIDOR AND NORTH...ESPECIALLY AS ENHANCED COOLING IN
THE MID-LEVELS BRINGS THE SNOW GROWTH ZONE LOW ENOUGH TO OVERLAP
THE TOP OF THE MOISTURE. STILL...OVERALL MOISTURE IS LIMITED
ULTIMATELY KEEPING ANY SNOW ACCUMULATION LIGHT.
TAX

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
PERSISTENCE WILL BE THE THEME OF THE SHORT TERM FORECAST AS SNOW
CHANCES WILL HOLD ACROSS THE NORTH AND CLOUDS WILL BE EVER-PRESENT. LLVL
CLOUDS EXPECTED TO LAST THROUGH THE SHORT TERM AS A MID-LEVEL
INVERSION TRAPS THE MOISTURE BELOW...SIMILAR TO WHAT WAS SEEN LATE
LAST WEEK. AS THE GREAT LAKES SFC LOW TRANSITIONS TO A DEEPENING LOW
OVER THE THE NEW ENGLAND COASTLINE ...MID-LEVEL FLOW VEERS TO THE
NW SUPPORTING ADDITIONAL LLVL MOISTURE INJECTION FROM THE UPSTREAM
GREAT LAKES. KEEPING AT LEAST A CHC OF SNOW SHOWERS ACROSS THE
NORTH THURS AS LAKE MOISTURE IS SQUEEZED OUT OVER OUR NRN TIER OF
COUNTIES. SHOWERS MAY DWINDLE AT TIMES THROUGH THE EVENING
HOURS...BUT ARE EXPECTED TO RE-INVIGORATE DURING THE OVERNIGHT
HOURS INTO EARLY FRI MORNING AS ANOTHER WEAK SW STREAMS THROUGH.

OUTSIDE OF THE LAKE EFFECT AREAS...PRECIPITATION SHOULD LARGELY REMAIN
OUT OF THE FORECAST WITH INSUFFICIENT MOISTURE PROGGED. MODELS
HAVE HINTED AT A WEAK WAVE CROSSING OUR SRN ZONES EARLY FRI
MORNING...WITH THE 00Z NAM BULLISH ON THIS FEATURE. DECIDED TO
HANG WITH ALL OF THE OTHER GUIDANCE WHICH KEEPS THE SOUTH AND WEST
ZONES DRY...BUT CLOUDY.
TAX

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
A SOUTHERN STREAM MID-LEVEL TROUGH WILL QUICKLY MIGRATE EAST AND
BRUSH ACROSS THE SOUTHERN EDGE OF THE FORECAST AREA ON SATURDAY
WITH THE BEST CHANCES OF ANY PRECIPITATION ON SATURDAY EVENING AND
OVERNIGHT ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST
AREA. ANY PRECIP SHOULD FALL IN THE FORM OF SNOW...BUT OVERALL
AMOUNTS WILL BE LIGHT AS FORCING LOOKS TO BE RELATIVELY WEAK AND
IN TEMPERATURES NOT FAVORABLE FOR SIGNIFICANT SNOW GROWTH. DRY
CONDITIONS THEN EXPECTED SUNDAY AFTERNOON AND INTO THE BEGINNING
OF NEXT WEEK AS THE LONGWAVE PATTERN AMPLIFIES AND AN UPPER TROUGH
DEEPENS ACROSS THE EASTERN CONUS. MODELS HAVE SHOWN DECENT
CONTINUITY WITH THIS FEATURE AND ANTICIPATE ABOVE NORMAL
TEMPERATURES DURING THE FIRST HALF OF NEXT WEEK AS WAA RAMPS UP
AHEAD OF THE TROUGH UNDER STRENGTHENING SOUTHWESTERLY FLOW. HAVE
OPTED TO KEEP THE FORECAST DRY THROUGH EARLY TUESDAY EVENING AND
INCREASE TEMPERATURES BOTH MONDAY AND TUESDAY FOR NOW BASED ON THE
LATEST BLEND OF THE EC AND GEFS...AND AN OVERALL RUN TO RUN TREND
AMONG MODELS IN SHOWING A DEEPER/SLOWER SOLUTION. 24HR QPF AMOUNTS
AT THIS TIME BETWEEN MODELS FOR THE MIDDLE OF NEXT WEEK RANGE
BETWEEN ONE HALF AND THREE QUARTERS OF AN INCH.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
IFR CIG RESTRICTIONS EXPECTED THE MAJORITY OF THE NIGHT FOR MOST
LOCATIONS WITH -RA COVERAGE DECREASING. WINDS WILL REMAIN GUSTY AT
OVERNIGHT AND CONTINUE DURING THE DAY AFTER A REINFORCING SHOT OF
COLD AIR MOVES THROUGH LATE THIS MORNING/EARLY AFTERNOON. GUIDANCE
CONTINUES TO MAINTAIN THE HIGH MVFR/LOW VFR STRATOCU FORECAST
DURING THE AFTERNOON WITH TRAPPED LOW LEVEL MOISTURE AND CONTINUED
CAA. MAIN CONCERN IS THE POSSIBILITY OF FREEZING DRIZZLE AFTER
TEMPERATURES FALL TO BELOW FREEZING THROUGHOUT THE COLUMN THIS
AFTERNOON ACROSS THE NORTH AND LATE AFTERNOON/EARLY EVENING
ACROSS SOUTHERN LOCATIONS...COUPLED WITH THE POTENTIAL THAT
MOISTURE MAY NOT BE DEEP/HIGH ENOUGH FOR ICE CRYSTAL DEVELOPMENT
ALOFT. FOR NOW HAVE OPTED TO REFRAIN FROM ANY MENTION OF
PRECIPITATION DURING THE DAY AS ANY PRECIP WOULD LIKELY BE LIGHT
FLURRIES MAINLY FOR KFKL AND KDUJ...BUT MAY NEED TO INCLUDE
MENTION OF FREEZING DRIZZLE WITH THE 12Z TAF SUITE AFTER
ASSESSMENT OF MORNING SOUNDINGS.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS EXPECTED THROUGHOUT THE WEEK WITH
TRAPPED LOW LEVEL MOISTURE AND CONTINUED CAA MAINTAINING STRATOCU
IN THE LOWER LEVELS.

&&

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

&&

$$







000
FXUS61 KPBZ 170952
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
452 AM EST WED DEC 17 2014

.SYNOPSIS...
COLDER AIR MOVING IN FROM THE WEST WILL KEEP HIGH TEMPERATURES
TODAY LOW. CLOUDS WILL REMAIN IN THE AREA THROUGH MID-WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
CURRENT RADAR IMAGERY CONTINUES TO SHOW SCATTERED WEAK ECHOES
INDICATING LIGHT RAIN SHOWERS WITH SOME PATCHY DRIZZLE. THE BULK
OF THE REMAINING SHOWERS SHOULD REMAIN LIGHT...AS MOISTURE ABOVE
H85 BEGINS TO DRY UP. NOW THROUGH 15Z...BEFORE H85 CAA KNOCKS
TEMPS DOWN TO ENOUGH TO GENERATE ICE CRYSTALS...DRIZZLE LOOKS TO
BE QUITE FAVORABLE. MENTIONED PATCHY DRIZZLE THIS MORNING ACROSS
THE SRN 2/3 OF THE CWA. FURTHER NORTH...THE DEEPER MOISTURE LOOKS
TO HOLD THROUGH MIDDAY...SO HELD DZ/FZDZ OUT ALONG I-80. IN THE
HIGHER ELEVATIONS IN THE RIDGES...TEMPS COULD DROP OFF ENOUGH TO
SEE SOME LIGHT PATCHY FZDZ...BUT NOT EXPECTING WIDESPREAD OR
APPRECIABLE ICING.

COLDER AIR WILL CONTINUE TO INVADE THROUGH THE MORNING WITH SFC
TEMPS FOLLOWING A NON-DIURNAL TREND. LATEST HRRR/LAMP HANDLE THE
COLD AIR PROGRESSION WELL. OPTED FOR A BLEND OF THESE THROUGH
MIDDAY...FAVORING THE MET BEYOND THAT PERIOD. TEMPS REGISTERED EARLY THIS
MORNING SHOULD LARGELY STAND AS THE HIGH TEMPS TODAY. 00Z NAM
SOUNDINGS CONTINUE TO LOOK EERILY SIMILAR TO LAST THURS/FRI WHERE
MOISTURE GETS TRAPPED UNDER AN H85 INVERSION AND IS UNABLE TO
DISLODGE FOR SOME TIME.

TONIGHT THE BULK OF THE DEEP MOISTURE EXITS NORTH AS A STRONG JET
TURNS THE FLOW MORE ZONAL. HI-RES NEAR TERM MODELS INDICATING A
DEEPENING OF THE BL MOISTURE DUE TO INJECTION OF LAKE MOISTURE NOT
FROM LAKE ERIE...BUT FROM THE SRN END OF LAKE MICHIGAN. MOISTURE
UP TO H8 SHOULD BE ENOUGH TO GENERATE SNOW SHOWERS TONIGHT ACROSS
THE I-80 CORRIDOR AND NORTH...ESPECIALLY AS ENHANCED COOLING IN
THE MID-LEVELS BRINGS THE SNOW GROWTH ZONE LOW ENOUGH TO OVERLAP
THE TOP OF THE MOISTURE. STILL...OVERALL MOISTURE IS LIMITED
ULTIMATELY KEEPING ANY SNOW ACCUMULATION LIGHT.
TAX

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
PERSISTENCE WILL BE THE THEME OF THE SHORT TERM FORECAST AS SNOW
CHANCES WILL HOLD ACROSS THE NORTH AND CLOUDS WILL BE EVER-PRESENT. LLVL
CLOUDS EXPECTED TO LAST THROUGH THE SHORT TERM AS A MID-LEVEL
INVERSION TRAPS THE MOISTURE BELOW...SIMILAR TO WHAT WAS SEEN LATE
LAST WEEK. AS THE GREAT LAKES SFC LOW TRANSITIONS TO A DEEPENING LOW
OVER THE THE NEW ENGLAND COASTLINE ...MID-LEVEL FLOW VEERS TO THE
NW SUPPORTING ADDITIONAL LLVL MOISTURE INJECTION FROM THE UPSTREAM
GREAT LAKES. KEEPING AT LEAST A CHC OF SNOW SHOWERS ACROSS THE
NORTH THURS AS LAKE MOISTURE IS SQUEEZED OUT OVER OUR NRN TIER OF
COUNTIES. SHOWERS MAY DWINDLE AT TIMES THROUGH THE EVENING
HOURS...BUT ARE EXPECTED TO RE-INVIGORATE DURING THE OVERNIGHT
HOURS INTO EARLY FRI MORNING AS ANOTHER WEAK SW STREAMS THROUGH.

OUTSIDE OF THE LAKE EFFECT AREAS...PRECIPITATION SHOULD LARGELY REMAIN
OUT OF THE FORECAST WITH INSUFFICIENT MOISTURE PROGGED. MODELS
HAVE HINTED AT A WEAK WAVE CROSSING OUR SRN ZONES EARLY FRI
MORNING...WITH THE 00Z NAM BULLISH ON THIS FEATURE. DECIDED TO
HANG WITH ALL OF THE OTHER GUIDANCE WHICH KEEPS THE SOUTH AND WEST
ZONES DRY...BUT CLOUDY.
TAX

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
A SOUTHERN STREAM MID-LEVEL TROUGH WILL QUICKLY MIGRATE EAST AND
BRUSH ACROSS THE SOUTHERN EDGE OF THE FORECAST AREA ON SATURDAY
WITH THE BEST CHANCES OF ANY PRECIPITATION ON SATURDAY EVENING AND
OVERNIGHT ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST
AREA. ANY PRECIP SHOULD FALL IN THE FORM OF SNOW...BUT OVERALL
AMOUNTS WILL BE LIGHT AS FORCING LOOKS TO BE RELATIVELY WEAK AND
IN TEMPERATURES NOT FAVORABLE FOR SIGNIFICANT SNOW GROWTH. DRY
CONDITIONS THEN EXPECTED SUNDAY AFTERNOON AND INTO THE BEGINNING
OF NEXT WEEK AS THE LONGWAVE PATTERN AMPLIFIES AND AN UPPER TROUGH
DEEPENS ACROSS THE EASTERN CONUS. MODELS HAVE SHOWN DECENT
CONTINUITY WITH THIS FEATURE AND ANTICIPATE ABOVE NORMAL
TEMPERATURES DURING THE FIRST HALF OF NEXT WEEK AS WAA RAMPS UP
AHEAD OF THE TROUGH UNDER STRENGTHENING SOUTHWESTERLY FLOW. HAVE
OPTED TO KEEP THE FORECAST DRY THROUGH EARLY TUESDAY EVENING AND
INCREASE TEMPERATURES BOTH MONDAY AND TUESDAY FOR NOW BASED ON THE
LATEST BLEND OF THE EC AND GEFS...AND AN OVERALL RUN TO RUN TREND
AMONG MODELS IN SHOWING A DEEPER/SLOWER SOLUTION. 24HR QPF AMOUNTS
AT THIS TIME BETWEEN MODELS FOR THE MIDDLE OF NEXT WEEK RANGE
BETWEEN ONE HALF AND THREE QUARTERS OF AN INCH.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
IFR CIG RESTRICTIONS EXPECTED THE MAJORITY OF THE NIGHT FOR MOST
LOCATIONS WITH -RA COVERAGE DECREASING. WINDS WILL REMAIN GUSTY AT
OVERNIGHT AND CONTINUE DURING THE DAY AFTER A REINFORCING SHOT OF
COLD AIR MOVES THROUGH LATE THIS MORNING/EARLY AFTERNOON. GUIDANCE
CONTINUES TO MAINTAIN THE HIGH MVFR/LOW VFR STRATOCU FORECAST
DURING THE AFTERNOON WITH TRAPPED LOW LEVEL MOISTURE AND CONTINUED
CAA. MAIN CONCERN IS THE POSSIBILITY OF FREEZING DRIZZLE AFTER
TEMPERATURES FALL TO BELOW FREEZING THROUGHOUT THE COLUMN THIS
AFTERNOON ACROSS THE NORTH AND LATE AFTERNOON/EARLY EVENING
ACROSS SOUTHERN LOCATIONS...COUPLED WITH THE POTENTIAL THAT
MOISTURE MAY NOT BE DEEP/HIGH ENOUGH FOR ICE CRYSTAL DEVELOPMENT
ALOFT. FOR NOW HAVE OPTED TO REFRAIN FROM ANY MENTION OF
PRECIPITATION DURING THE DAY AS ANY PRECIP WOULD LIKELY BE LIGHT
FLURRIES MAINLY FOR KFKL AND KDUJ...BUT MAY NEED TO INCLUDE
MENTION OF FREEZING DRIZZLE WITH THE 12Z TAF SUITE AFTER
ASSESSMENT OF MORNING SOUNDINGS.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS EXPECTED THROUGHOUT THE WEEK WITH
TRAPPED LOW LEVEL MOISTURE AND CONTINUED CAA MAINTAINING STRATOCU
IN THE LOWER LEVELS.

&&

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

&&

$$








000
FXUS61 KPBZ 170952
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
452 AM EST WED DEC 17 2014

.SYNOPSIS...
COLDER AIR MOVING IN FROM THE WEST WILL KEEP HIGH TEMPERATURES
TODAY LOW. CLOUDS WILL REMAIN IN THE AREA THROUGH MID-WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
CURRENT RADAR IMAGERY CONTINUES TO SHOW SCATTERED WEAK ECHOES
INDICATING LIGHT RAIN SHOWERS WITH SOME PATCHY DRIZZLE. THE BULK
OF THE REMAINING SHOWERS SHOULD REMAIN LIGHT...AS MOISTURE ABOVE
H85 BEGINS TO DRY UP. NOW THROUGH 15Z...BEFORE H85 CAA KNOCKS
TEMPS DOWN TO ENOUGH TO GENERATE ICE CRYSTALS...DRIZZLE LOOKS TO
BE QUITE FAVORABLE. MENTIONED PATCHY DRIZZLE THIS MORNING ACROSS
THE SRN 2/3 OF THE CWA. FURTHER NORTH...THE DEEPER MOISTURE LOOKS
TO HOLD THROUGH MIDDAY...SO HELD DZ/FZDZ OUT ALONG I-80. IN THE
HIGHER ELEVATIONS IN THE RIDGES...TEMPS COULD DROP OFF ENOUGH TO
SEE SOME LIGHT PATCHY FZDZ...BUT NOT EXPECTING WIDESPREAD OR
APPRECIABLE ICING.

COLDER AIR WILL CONTINUE TO INVADE THROUGH THE MORNING WITH SFC
TEMPS FOLLOWING A NON-DIURNAL TREND. LATEST HRRR/LAMP HANDLE THE
COLD AIR PROGRESSION WELL. OPTED FOR A BLEND OF THESE THROUGH
MIDDAY...FAVORING THE MET BEYOND THAT PERIOD. TEMPS REGISTERED EARLY THIS
MORNING SHOULD LARGELY STAND AS THE HIGH TEMPS TODAY. 00Z NAM
SOUNDINGS CONTINUE TO LOOK EERILY SIMILAR TO LAST THURS/FRI WHERE
MOISTURE GETS TRAPPED UNDER AN H85 INVERSION AND IS UNABLE TO
DISLODGE FOR SOME TIME.

TONIGHT THE BULK OF THE DEEP MOISTURE EXITS NORTH AS A STRONG JET
TURNS THE FLOW MORE ZONAL. HI-RES NEAR TERM MODELS INDICATING A
DEEPENING OF THE BL MOISTURE DUE TO INJECTION OF LAKE MOISTURE NOT
FROM LAKE ERIE...BUT FROM THE SRN END OF LAKE MICHIGAN. MOISTURE
UP TO H8 SHOULD BE ENOUGH TO GENERATE SNOW SHOWERS TONIGHT ACROSS
THE I-80 CORRIDOR AND NORTH...ESPECIALLY AS ENHANCED COOLING IN
THE MID-LEVELS BRINGS THE SNOW GROWTH ZONE LOW ENOUGH TO OVERLAP
THE TOP OF THE MOISTURE. STILL...OVERALL MOISTURE IS LIMITED
ULTIMATELY KEEPING ANY SNOW ACCUMULATION LIGHT.
TAX

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
PERSISTENCE WILL BE THE THEME OF THE SHORT TERM FORECAST AS SNOW
CHANCES WILL HOLD ACROSS THE NORTH AND CLOUDS WILL BE EVER-PRESENT. LLVL
CLOUDS EXPECTED TO LAST THROUGH THE SHORT TERM AS A MID-LEVEL
INVERSION TRAPS THE MOISTURE BELOW...SIMILAR TO WHAT WAS SEEN LATE
LAST WEEK. AS THE GREAT LAKES SFC LOW TRANSITIONS TO A DEEPENING LOW
OVER THE THE NEW ENGLAND COASTLINE ...MID-LEVEL FLOW VEERS TO THE
NW SUPPORTING ADDITIONAL LLVL MOISTURE INJECTION FROM THE UPSTREAM
GREAT LAKES. KEEPING AT LEAST A CHC OF SNOW SHOWERS ACROSS THE
NORTH THURS AS LAKE MOISTURE IS SQUEEZED OUT OVER OUR NRN TIER OF
COUNTIES. SHOWERS MAY DWINDLE AT TIMES THROUGH THE EVENING
HOURS...BUT ARE EXPECTED TO RE-INVIGORATE DURING THE OVERNIGHT
HOURS INTO EARLY FRI MORNING AS ANOTHER WEAK SW STREAMS THROUGH.

OUTSIDE OF THE LAKE EFFECT AREAS...PRECIPITATION SHOULD LARGELY REMAIN
OUT OF THE FORECAST WITH INSUFFICIENT MOISTURE PROGGED. MODELS
HAVE HINTED AT A WEAK WAVE CROSSING OUR SRN ZONES EARLY FRI
MORNING...WITH THE 00Z NAM BULLISH ON THIS FEATURE. DECIDED TO
HANG WITH ALL OF THE OTHER GUIDANCE WHICH KEEPS THE SOUTH AND WEST
ZONES DRY...BUT CLOUDY.
TAX

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
A SOUTHERN STREAM MID-LEVEL TROUGH WILL QUICKLY MIGRATE EAST AND
BRUSH ACROSS THE SOUTHERN EDGE OF THE FORECAST AREA ON SATURDAY
WITH THE BEST CHANCES OF ANY PRECIPITATION ON SATURDAY EVENING AND
OVERNIGHT ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST
AREA. ANY PRECIP SHOULD FALL IN THE FORM OF SNOW...BUT OVERALL
AMOUNTS WILL BE LIGHT AS FORCING LOOKS TO BE RELATIVELY WEAK AND
IN TEMPERATURES NOT FAVORABLE FOR SIGNIFICANT SNOW GROWTH. DRY
CONDITIONS THEN EXPECTED SUNDAY AFTERNOON AND INTO THE BEGINNING
OF NEXT WEEK AS THE LONGWAVE PATTERN AMPLIFIES AND AN UPPER TROUGH
DEEPENS ACROSS THE EASTERN CONUS. MODELS HAVE SHOWN DECENT
CONTINUITY WITH THIS FEATURE AND ANTICIPATE ABOVE NORMAL
TEMPERATURES DURING THE FIRST HALF OF NEXT WEEK AS WAA RAMPS UP
AHEAD OF THE TROUGH UNDER STRENGTHENING SOUTHWESTERLY FLOW. HAVE
OPTED TO KEEP THE FORECAST DRY THROUGH EARLY TUESDAY EVENING AND
INCREASE TEMPERATURES BOTH MONDAY AND TUESDAY FOR NOW BASED ON THE
LATEST BLEND OF THE EC AND GEFS...AND AN OVERALL RUN TO RUN TREND
AMONG MODELS IN SHOWING A DEEPER/SLOWER SOLUTION. 24HR QPF AMOUNTS
AT THIS TIME BETWEEN MODELS FOR THE MIDDLE OF NEXT WEEK RANGE
BETWEEN ONE HALF AND THREE QUARTERS OF AN INCH.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
IFR CIG RESTRICTIONS EXPECTED THE MAJORITY OF THE NIGHT FOR MOST
LOCATIONS WITH -RA COVERAGE DECREASING. WINDS WILL REMAIN GUSTY AT
OVERNIGHT AND CONTINUE DURING THE DAY AFTER A REINFORCING SHOT OF
COLD AIR MOVES THROUGH LATE THIS MORNING/EARLY AFTERNOON. GUIDANCE
CONTINUES TO MAINTAIN THE HIGH MVFR/LOW VFR STRATOCU FORECAST
DURING THE AFTERNOON WITH TRAPPED LOW LEVEL MOISTURE AND CONTINUED
CAA. MAIN CONCERN IS THE POSSIBILITY OF FREEZING DRIZZLE AFTER
TEMPERATURES FALL TO BELOW FREEZING THROUGHOUT THE COLUMN THIS
AFTERNOON ACROSS THE NORTH AND LATE AFTERNOON/EARLY EVENING
ACROSS SOUTHERN LOCATIONS...COUPLED WITH THE POTENTIAL THAT
MOISTURE MAY NOT BE DEEP/HIGH ENOUGH FOR ICE CRYSTAL DEVELOPMENT
ALOFT. FOR NOW HAVE OPTED TO REFRAIN FROM ANY MENTION OF
PRECIPITATION DURING THE DAY AS ANY PRECIP WOULD LIKELY BE LIGHT
FLURRIES MAINLY FOR KFKL AND KDUJ...BUT MAY NEED TO INCLUDE
MENTION OF FREEZING DRIZZLE WITH THE 12Z TAF SUITE AFTER
ASSESSMENT OF MORNING SOUNDINGS.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS EXPECTED THROUGHOUT THE WEEK WITH
TRAPPED LOW LEVEL MOISTURE AND CONTINUED CAA MAINTAINING STRATOCU
IN THE LOWER LEVELS.

&&

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

&&

$$








000
FXUS61 KPBZ 170952
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
452 AM EST WED DEC 17 2014

.SYNOPSIS...
COLDER AIR MOVING IN FROM THE WEST WILL KEEP HIGH TEMPERATURES
TODAY LOW. CLOUDS WILL REMAIN IN THE AREA THROUGH MID-WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
CURRENT RADAR IMAGERY CONTINUES TO SHOW SCATTERED WEAK ECHOES
INDICATING LIGHT RAIN SHOWERS WITH SOME PATCHY DRIZZLE. THE BULK
OF THE REMAINING SHOWERS SHOULD REMAIN LIGHT...AS MOISTURE ABOVE
H85 BEGINS TO DRY UP. NOW THROUGH 15Z...BEFORE H85 CAA KNOCKS
TEMPS DOWN TO ENOUGH TO GENERATE ICE CRYSTALS...DRIZZLE LOOKS TO
BE QUITE FAVORABLE. MENTIONED PATCHY DRIZZLE THIS MORNING ACROSS
THE SRN 2/3 OF THE CWA. FURTHER NORTH...THE DEEPER MOISTURE LOOKS
TO HOLD THROUGH MIDDAY...SO HELD DZ/FZDZ OUT ALONG I-80. IN THE
HIGHER ELEVATIONS IN THE RIDGES...TEMPS COULD DROP OFF ENOUGH TO
SEE SOME LIGHT PATCHY FZDZ...BUT NOT EXPECTING WIDESPREAD OR
APPRECIABLE ICING.

COLDER AIR WILL CONTINUE TO INVADE THROUGH THE MORNING WITH SFC
TEMPS FOLLOWING A NON-DIURNAL TREND. LATEST HRRR/LAMP HANDLE THE
COLD AIR PROGRESSION WELL. OPTED FOR A BLEND OF THESE THROUGH
MIDDAY...FAVORING THE MET BEYOND THAT PERIOD. TEMPS REGISTERED EARLY THIS
MORNING SHOULD LARGELY STAND AS THE HIGH TEMPS TODAY. 00Z NAM
SOUNDINGS CONTINUE TO LOOK EERILY SIMILAR TO LAST THURS/FRI WHERE
MOISTURE GETS TRAPPED UNDER AN H85 INVERSION AND IS UNABLE TO
DISLODGE FOR SOME TIME.

TONIGHT THE BULK OF THE DEEP MOISTURE EXITS NORTH AS A STRONG JET
TURNS THE FLOW MORE ZONAL. HI-RES NEAR TERM MODELS INDICATING A
DEEPENING OF THE BL MOISTURE DUE TO INJECTION OF LAKE MOISTURE NOT
FROM LAKE ERIE...BUT FROM THE SRN END OF LAKE MICHIGAN. MOISTURE
UP TO H8 SHOULD BE ENOUGH TO GENERATE SNOW SHOWERS TONIGHT ACROSS
THE I-80 CORRIDOR AND NORTH...ESPECIALLY AS ENHANCED COOLING IN
THE MID-LEVELS BRINGS THE SNOW GROWTH ZONE LOW ENOUGH TO OVERLAP
THE TOP OF THE MOISTURE. STILL...OVERALL MOISTURE IS LIMITED
ULTIMATELY KEEPING ANY SNOW ACCUMULATION LIGHT.
TAX

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
PERSISTENCE WILL BE THE THEME OF THE SHORT TERM FORECAST AS SNOW
CHANCES WILL HOLD ACROSS THE NORTH AND CLOUDS WILL BE EVER-PRESENT. LLVL
CLOUDS EXPECTED TO LAST THROUGH THE SHORT TERM AS A MID-LEVEL
INVERSION TRAPS THE MOISTURE BELOW...SIMILAR TO WHAT WAS SEEN LATE
LAST WEEK. AS THE GREAT LAKES SFC LOW TRANSITIONS TO A DEEPENING LOW
OVER THE THE NEW ENGLAND COASTLINE ...MID-LEVEL FLOW VEERS TO THE
NW SUPPORTING ADDITIONAL LLVL MOISTURE INJECTION FROM THE UPSTREAM
GREAT LAKES. KEEPING AT LEAST A CHC OF SNOW SHOWERS ACROSS THE
NORTH THURS AS LAKE MOISTURE IS SQUEEZED OUT OVER OUR NRN TIER OF
COUNTIES. SHOWERS MAY DWINDLE AT TIMES THROUGH THE EVENING
HOURS...BUT ARE EXPECTED TO RE-INVIGORATE DURING THE OVERNIGHT
HOURS INTO EARLY FRI MORNING AS ANOTHER WEAK SW STREAMS THROUGH.

OUTSIDE OF THE LAKE EFFECT AREAS...PRECIPITATION SHOULD LARGELY REMAIN
OUT OF THE FORECAST WITH INSUFFICIENT MOISTURE PROGGED. MODELS
HAVE HINTED AT A WEAK WAVE CROSSING OUR SRN ZONES EARLY FRI
MORNING...WITH THE 00Z NAM BULLISH ON THIS FEATURE. DECIDED TO
HANG WITH ALL OF THE OTHER GUIDANCE WHICH KEEPS THE SOUTH AND WEST
ZONES DRY...BUT CLOUDY.
TAX

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
A SOUTHERN STREAM MID-LEVEL TROUGH WILL QUICKLY MIGRATE EAST AND
BRUSH ACROSS THE SOUTHERN EDGE OF THE FORECAST AREA ON SATURDAY
WITH THE BEST CHANCES OF ANY PRECIPITATION ON SATURDAY EVENING AND
OVERNIGHT ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST
AREA. ANY PRECIP SHOULD FALL IN THE FORM OF SNOW...BUT OVERALL
AMOUNTS WILL BE LIGHT AS FORCING LOOKS TO BE RELATIVELY WEAK AND
IN TEMPERATURES NOT FAVORABLE FOR SIGNIFICANT SNOW GROWTH. DRY
CONDITIONS THEN EXPECTED SUNDAY AFTERNOON AND INTO THE BEGINNING
OF NEXT WEEK AS THE LONGWAVE PATTERN AMPLIFIES AND AN UPPER TROUGH
DEEPENS ACROSS THE EASTERN CONUS. MODELS HAVE SHOWN DECENT
CONTINUITY WITH THIS FEATURE AND ANTICIPATE ABOVE NORMAL
TEMPERATURES DURING THE FIRST HALF OF NEXT WEEK AS WAA RAMPS UP
AHEAD OF THE TROUGH UNDER STRENGTHENING SOUTHWESTERLY FLOW. HAVE
OPTED TO KEEP THE FORECAST DRY THROUGH EARLY TUESDAY EVENING AND
INCREASE TEMPERATURES BOTH MONDAY AND TUESDAY FOR NOW BASED ON THE
LATEST BLEND OF THE EC AND GEFS...AND AN OVERALL RUN TO RUN TREND
AMONG MODELS IN SHOWING A DEEPER/SLOWER SOLUTION. 24HR QPF AMOUNTS
AT THIS TIME BETWEEN MODELS FOR THE MIDDLE OF NEXT WEEK RANGE
BETWEEN ONE HALF AND THREE QUARTERS OF AN INCH.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
IFR CIG RESTRICTIONS EXPECTED THE MAJORITY OF THE NIGHT FOR MOST
LOCATIONS WITH -RA COVERAGE DECREASING. WINDS WILL REMAIN GUSTY AT
OVERNIGHT AND CONTINUE DURING THE DAY AFTER A REINFORCING SHOT OF
COLD AIR MOVES THROUGH LATE THIS MORNING/EARLY AFTERNOON. GUIDANCE
CONTINUES TO MAINTAIN THE HIGH MVFR/LOW VFR STRATOCU FORECAST
DURING THE AFTERNOON WITH TRAPPED LOW LEVEL MOISTURE AND CONTINUED
CAA. MAIN CONCERN IS THE POSSIBILITY OF FREEZING DRIZZLE AFTER
TEMPERATURES FALL TO BELOW FREEZING THROUGHOUT THE COLUMN THIS
AFTERNOON ACROSS THE NORTH AND LATE AFTERNOON/EARLY EVENING
ACROSS SOUTHERN LOCATIONS...COUPLED WITH THE POTENTIAL THAT
MOISTURE MAY NOT BE DEEP/HIGH ENOUGH FOR ICE CRYSTAL DEVELOPMENT
ALOFT. FOR NOW HAVE OPTED TO REFRAIN FROM ANY MENTION OF
PRECIPITATION DURING THE DAY AS ANY PRECIP WOULD LIKELY BE LIGHT
FLURRIES MAINLY FOR KFKL AND KDUJ...BUT MAY NEED TO INCLUDE
MENTION OF FREEZING DRIZZLE WITH THE 12Z TAF SUITE AFTER
ASSESSMENT OF MORNING SOUNDINGS.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS EXPECTED THROUGHOUT THE WEEK WITH
TRAPPED LOW LEVEL MOISTURE AND CONTINUED CAA MAINTAINING STRATOCU
IN THE LOWER LEVELS.

&&

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

&&

$$







000
FXUS61 KPBZ 170746
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
246 AM EST WED DEC 17 2014

.SYNOPSIS...
COLDER AIR MOVING IN FROM THE WEST WILL KEEP HIGH TEMPERATURES
TODAY LOW. CLOUDS WILL REMAIN IN THE AREA THROUGH MID-WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
CURRENT RADAR IMAGERY SHOWING RAIN SHOWER ACTIVITY EVACUATING THE
NORTHEAST CWA...BUT COPIOUS LLVL MOISTURE REMAINS. ADDITIONAL
SHOWERS BEGINNING TO FLOURISH ACROSS SOUTH-CENTRAL OHIO AHEAD OF A
JET NOSING IN FROM THE WEST. THIS ACTIVITY SHOULD REMAIN ALONG THE
SRN PERIPHERY OF THE CWA...DESPITE MOISTURE ABOVE H85 DRYING UP. BETWEEN
09-15Z...BEFORE H85 CAA KNOCKS TEMPS DOWN TO GENERATE ENOUGH ICE
CRYSTALS TO INCORPORATE LIGHT SNOW...DRIZZLE LOOKS TO BE QUITE
FAVORABLE. MENTIONED PATCHY DRIZZLE THIS MORNING ACROSS THE SRN
2/3 OF THE CWA. FURTHER NORTH...THE DEEPER MOISTURE LOOKS TO HOLD
THROUGH MIDDAY...SO HELD DZ/FZDZ OUT ALONG I-80. IN THE HIGHER
ELEVATIONS IN THE RIDGES...TEMPS COULD DROP OFF ENOUGH TO SEE SOME
LIGHT PATCHY FZDZ...BUT NOT EXPECTING WIDESPREAD OR APPRECIABLE ICING.

COLDER AIR WILL CONTINUE TO INVADE THROUGH THE MORNING WITH SFC
TEMPS FOLLOWING A NON-DIURNAL TREND. LATEST HRRR/LAMP HANDLE THE
COLD AIR PROGRESSION WELL. OPTED FOR A BLEND OF THESE THROUGH
MIDDAY...FAVORING THE MET BEYOND THAT PERIOD. TEMPS REGISTERED EARLY THIS
MORNING SHOULD LARGELY STAND AS THE HIGH TEMPS TODAY. 00Z NAM
SOUNDINGS CONTINUE TO LOOK EERILY SIMILAR TO LAST THURS/FRI WHERE
MOISTURE GETS TRAPPED UNDER AN H85 INVERSION AND IS UNABLE TO
DISLODGE. LLVL CLOUDS SHOULD HOLD HEADING INTO MID- WEEK.
TAX

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
AS STORM SYSTEM WINDS UP OFFSHORE NEW ENGLAND THURSDAY FLOW WILL
TURN NORTHWEST FOR A TIME WITH SNOW SHOWER CHANCES INCREASING
ACROSS THE NORTH INTO THE RIDGES. AGAIN INVERSION HEIGHTS LOOK
LOW ON FORECAST SOUNDINGS SO ONLY CHANCE POPS WITH A LIGHT
ACCUMULATION. THURSDAY NIGHT INTO FRIDAY A FAST MOVING SHORTWAVE
WILL SLIDE EAST IN DEVELOPING ZONAL FLOW. ADDED SCATTERED FLURRIES
WITH CONTINUED COLD TEMPERATURES.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPR TROF MOVG OUT OF THE CNTRL CONUS WL RTN PCPN CHCS FOR THE
WEEKEND.  CHC POPS WERE MAINTAINED WITH UNCERTAINTY IN NRN EXTENT OF
ANY PCPN AND THE TRACK OF THE ATTENDANT SFC LOW.  SEASONAL TEMPS
WERE FORECAST CLOSE TO WPC GUIDANCE.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
IFR CIG RESTRICTIONS EXPECTED THE MAJORITY OF THE NIGHT FOR MOST
LOCATIONS WITH -RA COVERAGE DECREASING. WINDS WILL REMAIN GUSTY AT
OVERNIGHT AND CONTINUE DURING THE DAY AFTER A REINFORCING SHOT OF
COLD AIR MOVES THROUGH LATE THIS MORNING/EARLY AFTERNOON. GUIDANCE
CONTINUES TO MAINTAIN THE HIGH MVFR/LOW VFR STRATOCU FORECAST
DURING THE AFTERNOON WITH TRAPPED LOW LEVEL MOISTURE AND CONTINUED
CAA. MAIN CONCERN IS THE POSSIBILITY OF FREEZING DRIZZLE AFTER
TEMPERATURES FALL TO BELOW FREEZING THROUGHOUT THE COLUMN THIS
AFTERNOON ACROSS THE NORTH AND LATE AFTERNOON/EARLY EVENING
ACROSS SOUTHERN LOCATIONS...COUPLED WITH THE POTENTIAL THAT
MOISTURE MAY NOT BE DEEP/HIGH ENOUGH FOR ICE CRYSTAL DEVELOPMENT
ALOFT. FOR NOW HAVE OPTED TO REFRAIN FROM ANY MENTION OF
PRECIPITATION DURING THE DAY AS ANY PRECIP WOULD LIKELY BE LIGHT
FLURRIES MAINLY FOR KFKL AND KDUJ...BUT MAY NEED TO INCLUDE
MENTION OF FREEZING DRIZZLE WITH THE 12Z TAF SUITE AFTER
ASSESSMENT OF MORNING SOUNDINGS.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS EXPECTED THROUGHOUT THE WEEK WITH
TRAPPED LOW LEVEL MOISTURE AND CONTINUED CAA MAINTAINING STRATOCU
IN THE LOWER LEVELS.

&&

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

&&

$$








000
FXUS61 KPBZ 170746
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
246 AM EST WED DEC 17 2014

.SYNOPSIS...
COLDER AIR MOVING IN FROM THE WEST WILL KEEP HIGH TEMPERATURES
TODAY LOW. CLOUDS WILL REMAIN IN THE AREA THROUGH MID-WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
CURRENT RADAR IMAGERY SHOWING RAIN SHOWER ACTIVITY EVACUATING THE
NORTHEAST CWA...BUT COPIOUS LLVL MOISTURE REMAINS. ADDITIONAL
SHOWERS BEGINNING TO FLOURISH ACROSS SOUTH-CENTRAL OHIO AHEAD OF A
JET NOSING IN FROM THE WEST. THIS ACTIVITY SHOULD REMAIN ALONG THE
SRN PERIPHERY OF THE CWA...DESPITE MOISTURE ABOVE H85 DRYING UP. BETWEEN
09-15Z...BEFORE H85 CAA KNOCKS TEMPS DOWN TO GENERATE ENOUGH ICE
CRYSTALS TO INCORPORATE LIGHT SNOW...DRIZZLE LOOKS TO BE QUITE
FAVORABLE. MENTIONED PATCHY DRIZZLE THIS MORNING ACROSS THE SRN
2/3 OF THE CWA. FURTHER NORTH...THE DEEPER MOISTURE LOOKS TO HOLD
THROUGH MIDDAY...SO HELD DZ/FZDZ OUT ALONG I-80. IN THE HIGHER
ELEVATIONS IN THE RIDGES...TEMPS COULD DROP OFF ENOUGH TO SEE SOME
LIGHT PATCHY FZDZ...BUT NOT EXPECTING WIDESPREAD OR APPRECIABLE ICING.

COLDER AIR WILL CONTINUE TO INVADE THROUGH THE MORNING WITH SFC
TEMPS FOLLOWING A NON-DIURNAL TREND. LATEST HRRR/LAMP HANDLE THE
COLD AIR PROGRESSION WELL. OPTED FOR A BLEND OF THESE THROUGH
MIDDAY...FAVORING THE MET BEYOND THAT PERIOD. TEMPS REGISTERED EARLY THIS
MORNING SHOULD LARGELY STAND AS THE HIGH TEMPS TODAY. 00Z NAM
SOUNDINGS CONTINUE TO LOOK EERILY SIMILAR TO LAST THURS/FRI WHERE
MOISTURE GETS TRAPPED UNDER AN H85 INVERSION AND IS UNABLE TO
DISLODGE. LLVL CLOUDS SHOULD HOLD HEADING INTO MID- WEEK.
TAX

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
AS STORM SYSTEM WINDS UP OFFSHORE NEW ENGLAND THURSDAY FLOW WILL
TURN NORTHWEST FOR A TIME WITH SNOW SHOWER CHANCES INCREASING
ACROSS THE NORTH INTO THE RIDGES. AGAIN INVERSION HEIGHTS LOOK
LOW ON FORECAST SOUNDINGS SO ONLY CHANCE POPS WITH A LIGHT
ACCUMULATION. THURSDAY NIGHT INTO FRIDAY A FAST MOVING SHORTWAVE
WILL SLIDE EAST IN DEVELOPING ZONAL FLOW. ADDED SCATTERED FLURRIES
WITH CONTINUED COLD TEMPERATURES.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPR TROF MOVG OUT OF THE CNTRL CONUS WL RTN PCPN CHCS FOR THE
WEEKEND.  CHC POPS WERE MAINTAINED WITH UNCERTAINTY IN NRN EXTENT OF
ANY PCPN AND THE TRACK OF THE ATTENDANT SFC LOW.  SEASONAL TEMPS
WERE FORECAST CLOSE TO WPC GUIDANCE.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
IFR CIG RESTRICTIONS EXPECTED THE MAJORITY OF THE NIGHT FOR MOST
LOCATIONS WITH -RA COVERAGE DECREASING. WINDS WILL REMAIN GUSTY AT
OVERNIGHT AND CONTINUE DURING THE DAY AFTER A REINFORCING SHOT OF
COLD AIR MOVES THROUGH LATE THIS MORNING/EARLY AFTERNOON. GUIDANCE
CONTINUES TO MAINTAIN THE HIGH MVFR/LOW VFR STRATOCU FORECAST
DURING THE AFTERNOON WITH TRAPPED LOW LEVEL MOISTURE AND CONTINUED
CAA. MAIN CONCERN IS THE POSSIBILITY OF FREEZING DRIZZLE AFTER
TEMPERATURES FALL TO BELOW FREEZING THROUGHOUT THE COLUMN THIS
AFTERNOON ACROSS THE NORTH AND LATE AFTERNOON/EARLY EVENING
ACROSS SOUTHERN LOCATIONS...COUPLED WITH THE POTENTIAL THAT
MOISTURE MAY NOT BE DEEP/HIGH ENOUGH FOR ICE CRYSTAL DEVELOPMENT
ALOFT. FOR NOW HAVE OPTED TO REFRAIN FROM ANY MENTION OF
PRECIPITATION DURING THE DAY AS ANY PRECIP WOULD LIKELY BE LIGHT
FLURRIES MAINLY FOR KFKL AND KDUJ...BUT MAY NEED TO INCLUDE
MENTION OF FREEZING DRIZZLE WITH THE 12Z TAF SUITE AFTER
ASSESSMENT OF MORNING SOUNDINGS.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS EXPECTED THROUGHOUT THE WEEK WITH
TRAPPED LOW LEVEL MOISTURE AND CONTINUED CAA MAINTAINING STRATOCU
IN THE LOWER LEVELS.

&&

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

&&

$$








000
FXUS61 KPBZ 170746
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
246 AM EST WED DEC 17 2014

.SYNOPSIS...
COLDER AIR MOVING IN FROM THE WEST WILL KEEP HIGH TEMPERATURES
TODAY LOW. CLOUDS WILL REMAIN IN THE AREA THROUGH MID-WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
CURRENT RADAR IMAGERY SHOWING RAIN SHOWER ACTIVITY EVACUATING THE
NORTHEAST CWA...BUT COPIOUS LLVL MOISTURE REMAINS. ADDITIONAL
SHOWERS BEGINNING TO FLOURISH ACROSS SOUTH-CENTRAL OHIO AHEAD OF A
JET NOSING IN FROM THE WEST. THIS ACTIVITY SHOULD REMAIN ALONG THE
SRN PERIPHERY OF THE CWA...DESPITE MOISTURE ABOVE H85 DRYING UP. BETWEEN
09-15Z...BEFORE H85 CAA KNOCKS TEMPS DOWN TO GENERATE ENOUGH ICE
CRYSTALS TO INCORPORATE LIGHT SNOW...DRIZZLE LOOKS TO BE QUITE
FAVORABLE. MENTIONED PATCHY DRIZZLE THIS MORNING ACROSS THE SRN
2/3 OF THE CWA. FURTHER NORTH...THE DEEPER MOISTURE LOOKS TO HOLD
THROUGH MIDDAY...SO HELD DZ/FZDZ OUT ALONG I-80. IN THE HIGHER
ELEVATIONS IN THE RIDGES...TEMPS COULD DROP OFF ENOUGH TO SEE SOME
LIGHT PATCHY FZDZ...BUT NOT EXPECTING WIDESPREAD OR APPRECIABLE ICING.

COLDER AIR WILL CONTINUE TO INVADE THROUGH THE MORNING WITH SFC
TEMPS FOLLOWING A NON-DIURNAL TREND. LATEST HRRR/LAMP HANDLE THE
COLD AIR PROGRESSION WELL. OPTED FOR A BLEND OF THESE THROUGH
MIDDAY...FAVORING THE MET BEYOND THAT PERIOD. TEMPS REGISTERED EARLY THIS
MORNING SHOULD LARGELY STAND AS THE HIGH TEMPS TODAY. 00Z NAM
SOUNDINGS CONTINUE TO LOOK EERILY SIMILAR TO LAST THURS/FRI WHERE
MOISTURE GETS TRAPPED UNDER AN H85 INVERSION AND IS UNABLE TO
DISLODGE. LLVL CLOUDS SHOULD HOLD HEADING INTO MID- WEEK.
TAX

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
AS STORM SYSTEM WINDS UP OFFSHORE NEW ENGLAND THURSDAY FLOW WILL
TURN NORTHWEST FOR A TIME WITH SNOW SHOWER CHANCES INCREASING
ACROSS THE NORTH INTO THE RIDGES. AGAIN INVERSION HEIGHTS LOOK
LOW ON FORECAST SOUNDINGS SO ONLY CHANCE POPS WITH A LIGHT
ACCUMULATION. THURSDAY NIGHT INTO FRIDAY A FAST MOVING SHORTWAVE
WILL SLIDE EAST IN DEVELOPING ZONAL FLOW. ADDED SCATTERED FLURRIES
WITH CONTINUED COLD TEMPERATURES.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPR TROF MOVG OUT OF THE CNTRL CONUS WL RTN PCPN CHCS FOR THE
WEEKEND.  CHC POPS WERE MAINTAINED WITH UNCERTAINTY IN NRN EXTENT OF
ANY PCPN AND THE TRACK OF THE ATTENDANT SFC LOW.  SEASONAL TEMPS
WERE FORECAST CLOSE TO WPC GUIDANCE.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
IFR CIG RESTRICTIONS EXPECTED THE MAJORITY OF THE NIGHT FOR MOST
LOCATIONS WITH -RA COVERAGE DECREASING. WINDS WILL REMAIN GUSTY AT
OVERNIGHT AND CONTINUE DURING THE DAY AFTER A REINFORCING SHOT OF
COLD AIR MOVES THROUGH LATE THIS MORNING/EARLY AFTERNOON. GUIDANCE
CONTINUES TO MAINTAIN THE HIGH MVFR/LOW VFR STRATOCU FORECAST
DURING THE AFTERNOON WITH TRAPPED LOW LEVEL MOISTURE AND CONTINUED
CAA. MAIN CONCERN IS THE POSSIBILITY OF FREEZING DRIZZLE AFTER
TEMPERATURES FALL TO BELOW FREEZING THROUGHOUT THE COLUMN THIS
AFTERNOON ACROSS THE NORTH AND LATE AFTERNOON/EARLY EVENING
ACROSS SOUTHERN LOCATIONS...COUPLED WITH THE POTENTIAL THAT
MOISTURE MAY NOT BE DEEP/HIGH ENOUGH FOR ICE CRYSTAL DEVELOPMENT
ALOFT. FOR NOW HAVE OPTED TO REFRAIN FROM ANY MENTION OF
PRECIPITATION DURING THE DAY AS ANY PRECIP WOULD LIKELY BE LIGHT
FLURRIES MAINLY FOR KFKL AND KDUJ...BUT MAY NEED TO INCLUDE
MENTION OF FREEZING DRIZZLE WITH THE 12Z TAF SUITE AFTER
ASSESSMENT OF MORNING SOUNDINGS.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS EXPECTED THROUGHOUT THE WEEK WITH
TRAPPED LOW LEVEL MOISTURE AND CONTINUED CAA MAINTAINING STRATOCU
IN THE LOWER LEVELS.

&&

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

&&

$$







000
FXUS61 KPBZ 170651
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
151 AM EST WED DEC 17 2014

.SYNOPSIS...
SHOWERS WILL DIMINISH OVERNIGHT AS COLDER AIR MOVES INTO THE
REGION.

&&

.NEAR TERM /THROUGH TODAY/...
DEFORMATION ALONG THE 700 MB FRONTAL ZONE SEEMS TO BE DRIVING A
SECONDARY INCREASE IN SHOWER ACTIVITY AS THE 700-500 MB COLD POOL
FRONT EDGE DRIVES SOUTHEASTWARD INTO EASTERN OHIO TOWARD THE
PANHANDLE OF WEST VIRGINIA. THIS SHOULD SECONDARILY INCREASE
SHOWERS ACROSS THE AREA AGAIN AS THE EVENING WEARS ON.

COLD ADVECTION GETS RAMPED UP OVER THE ENTIRE AREA
OVERNIGHT...HOWEVER SIGNIFICANTLY COLDER AIR LAGS THE SURFACE
FRONT FROM HUNDREDS OF MILES...AND IS LIKELY TRULY BOTTLED UP
BEHIND A SECONDARY COLD BOUNDARY OVER THE LOWER OHIO VALLEY AND
WESTERN GREAT LAKES. THIS WILL ALLOW FOR MUCH OF THE NIGHT TO
CONTINUE WITH TEMPERATURES ONLY SLOWLY FALLING. IT WILL ALSO
PRECLUDE MUCH OF ANYTHING BUT LIQUID PHASE HYDROMETEORS IN THE
CWA.

LOOKING AT BOTH THE NAM AND GFS OUTPUT...SURFACE TEMPERATURES EVEN
IN THE RIDGES WILL TAKE UNTIL SUNRISE TO COME CLOSE TO FREEZING.
THIS WILL SLOW ANY CHANGEOVER TO SNOW AS THE MOIST LAYER LEANS
OUT...AND ICE MICROPHYSICS BECOME PROBLEMATIC TO SNOW CRYSTAL
GROWTH. AS SUCH...IT WOULD SEEM IT SHOULD BE DAYTIME BEFORE ANY
SNOW IS REALLY NOTED IN THE CWA...AND EVEN THEN...IT IS UNLIKELY
TO BE PARTICULARLY EFFICIENT AT ACCUMULATING DUE TO POOR DENDRITIC
GROWTH ZONE SATURATION.

ADVECTION THROUGH THE NIGHT AND INTO THE DAY ON WEDNESDAY SHOULD
ALLOW FOR A RELATIVELY NON-DIURNAL TEMPERATURE CURVE ON WEDNESDAY.
TEMPERATURES WERE ADJUSTED TO ALLOW FOR LOWER AFTERNOON
TEMPERATURES WITH MORNING HIGHS AS A RESULT. FRIES

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
AS STORM SYSTEM WINDS UP OFFSHORE NEW ENGLAND THURSDAY FLOW WILL
TURN NORTHWEST FOR A TIME WITH SNOW SHOWER CHANCES INCREASING
ACROSS THE NORTH INTO THE RIDGES. AGAIN INVERSION HEIGHTS LOOK
LOW ON FORECAST SOUNDINGS SO ONLY CHANCE POPS WITH A LIGHT
ACCUMULATION. THURSDAY NIGHT INTO FRIDAY A FAST MOVING SHORTWAVE
WILL SLIDE EAST IN DEVELOPING ZONAL FLOW. ADDED SCATTERED FLURRIES
WITH CONTINUED COLD TEMPERATURES.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPR TROF MOVG OUT OF THE CNTRL CONUS WL RTN PCPN CHCS FOR THE
WEEKEND.  CHC POPS WERE MAINTAINED WITH UNCERTAINTY IN NRN EXTENT OF
ANY PCPN AND THE TRACK OF THE ATTENDANT SFC LOW.  SEASONAL TEMPS
WERE FORECAST CLOSE TO WPC GUIDANCE.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
IFR CIG RESTRICTIONS EXPECTED THE MAJORITY OF THE NIGHT FOR MOST
LOCATIONS WITH -RA COVERAGE DECREASING. WINDS WILL REMAIN GUSTY AT
OVERNIGHT AND CONTINUE DURING THE DAY AFTER A REINFORCING SHOT OF
COLD AIR MOVES THROUGH LATE THIS MORNING/EARLY AFTERNOON. GUIDANCE
CONTINUES TO MAINTAIN THE HIGH MVFR/LOW VFR STRATOCU FORECAST
DURING THE AFTERNOON WITH TRAPPED LOW LEVEL MOISTURE AND CONTINUED
CAA. MAIN CONCERN IS THE POSSIBILITY OF FREEZING DRIZZLE AFTER
TEMPERATURES FALL TO BELOW FREEZING THROUGHOUT THE COLUMN THIS
AFTERNOON ACROSS THE NORTH AND LATE AFTERNOON/EARLY EVENING
ACROSS SOUTHERN LOCATIONS...COUPLED WITH THE POTENTIAL THAT
MOISTURE MAY NOT BE DEEP/HIGH ENOUGH FOR ICE CRYSTAL DEVELOPMENT
ALOFT. FOR NOW HAVE OPTED TO REFRAIN FROM ANY MENTION OF
PRECIPITATION DURING THE DAY AS ANY PRECIP WOULD LIKELY BE LIGHT
FLURRIES MAINLY FOR KFKL AND KDUJ...BUT MAY NEED TO INCLUDE
MENTION OF FREEZING DRIZZLE WITH THE 12Z TAF SUITE AFTER
ASSESSMENT OF MORNING SOUNDINGS.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS EXPECTED THROUGHOUT THE WEEK WITH
TRAPPED LOW LEVEL MOISTURE AND CONTINUED CAA MAINTAINING STRATOCU
IN THE LOWER LEVELS.

&&

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

&&

$$








000
FXUS61 KPBZ 170651
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
151 AM EST WED DEC 17 2014

.SYNOPSIS...
SHOWERS WILL DIMINISH OVERNIGHT AS COLDER AIR MOVES INTO THE
REGION.

&&

.NEAR TERM /THROUGH TODAY/...
DEFORMATION ALONG THE 700 MB FRONTAL ZONE SEEMS TO BE DRIVING A
SECONDARY INCREASE IN SHOWER ACTIVITY AS THE 700-500 MB COLD POOL
FRONT EDGE DRIVES SOUTHEASTWARD INTO EASTERN OHIO TOWARD THE
PANHANDLE OF WEST VIRGINIA. THIS SHOULD SECONDARILY INCREASE
SHOWERS ACROSS THE AREA AGAIN AS THE EVENING WEARS ON.

COLD ADVECTION GETS RAMPED UP OVER THE ENTIRE AREA
OVERNIGHT...HOWEVER SIGNIFICANTLY COLDER AIR LAGS THE SURFACE
FRONT FROM HUNDREDS OF MILES...AND IS LIKELY TRULY BOTTLED UP
BEHIND A SECONDARY COLD BOUNDARY OVER THE LOWER OHIO VALLEY AND
WESTERN GREAT LAKES. THIS WILL ALLOW FOR MUCH OF THE NIGHT TO
CONTINUE WITH TEMPERATURES ONLY SLOWLY FALLING. IT WILL ALSO
PRECLUDE MUCH OF ANYTHING BUT LIQUID PHASE HYDROMETEORS IN THE
CWA.

LOOKING AT BOTH THE NAM AND GFS OUTPUT...SURFACE TEMPERATURES EVEN
IN THE RIDGES WILL TAKE UNTIL SUNRISE TO COME CLOSE TO FREEZING.
THIS WILL SLOW ANY CHANGEOVER TO SNOW AS THE MOIST LAYER LEANS
OUT...AND ICE MICROPHYSICS BECOME PROBLEMATIC TO SNOW CRYSTAL
GROWTH. AS SUCH...IT WOULD SEEM IT SHOULD BE DAYTIME BEFORE ANY
SNOW IS REALLY NOTED IN THE CWA...AND EVEN THEN...IT IS UNLIKELY
TO BE PARTICULARLY EFFICIENT AT ACCUMULATING DUE TO POOR DENDRITIC
GROWTH ZONE SATURATION.

ADVECTION THROUGH THE NIGHT AND INTO THE DAY ON WEDNESDAY SHOULD
ALLOW FOR A RELATIVELY NON-DIURNAL TEMPERATURE CURVE ON WEDNESDAY.
TEMPERATURES WERE ADJUSTED TO ALLOW FOR LOWER AFTERNOON
TEMPERATURES WITH MORNING HIGHS AS A RESULT. FRIES

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
AS STORM SYSTEM WINDS UP OFFSHORE NEW ENGLAND THURSDAY FLOW WILL
TURN NORTHWEST FOR A TIME WITH SNOW SHOWER CHANCES INCREASING
ACROSS THE NORTH INTO THE RIDGES. AGAIN INVERSION HEIGHTS LOOK
LOW ON FORECAST SOUNDINGS SO ONLY CHANCE POPS WITH A LIGHT
ACCUMULATION. THURSDAY NIGHT INTO FRIDAY A FAST MOVING SHORTWAVE
WILL SLIDE EAST IN DEVELOPING ZONAL FLOW. ADDED SCATTERED FLURRIES
WITH CONTINUED COLD TEMPERATURES.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPR TROF MOVG OUT OF THE CNTRL CONUS WL RTN PCPN CHCS FOR THE
WEEKEND.  CHC POPS WERE MAINTAINED WITH UNCERTAINTY IN NRN EXTENT OF
ANY PCPN AND THE TRACK OF THE ATTENDANT SFC LOW.  SEASONAL TEMPS
WERE FORECAST CLOSE TO WPC GUIDANCE.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
IFR CIG RESTRICTIONS EXPECTED THE MAJORITY OF THE NIGHT FOR MOST
LOCATIONS WITH -RA COVERAGE DECREASING. WINDS WILL REMAIN GUSTY AT
OVERNIGHT AND CONTINUE DURING THE DAY AFTER A REINFORCING SHOT OF
COLD AIR MOVES THROUGH LATE THIS MORNING/EARLY AFTERNOON. GUIDANCE
CONTINUES TO MAINTAIN THE HIGH MVFR/LOW VFR STRATOCU FORECAST
DURING THE AFTERNOON WITH TRAPPED LOW LEVEL MOISTURE AND CONTINUED
CAA. MAIN CONCERN IS THE POSSIBILITY OF FREEZING DRIZZLE AFTER
TEMPERATURES FALL TO BELOW FREEZING THROUGHOUT THE COLUMN THIS
AFTERNOON ACROSS THE NORTH AND LATE AFTERNOON/EARLY EVENING
ACROSS SOUTHERN LOCATIONS...COUPLED WITH THE POTENTIAL THAT
MOISTURE MAY NOT BE DEEP/HIGH ENOUGH FOR ICE CRYSTAL DEVELOPMENT
ALOFT. FOR NOW HAVE OPTED TO REFRAIN FROM ANY MENTION OF
PRECIPITATION DURING THE DAY AS ANY PRECIP WOULD LIKELY BE LIGHT
FLURRIES MAINLY FOR KFKL AND KDUJ...BUT MAY NEED TO INCLUDE
MENTION OF FREEZING DRIZZLE WITH THE 12Z TAF SUITE AFTER
ASSESSMENT OF MORNING SOUNDINGS.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC CIG RESTRICTIONS EXPECTED THROUGHOUT THE WEEK WITH
TRAPPED LOW LEVEL MOISTURE AND CONTINUED CAA MAINTAINING STRATOCU
IN THE LOWER LEVELS.

&&

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

&&

$$







000
FXUS61 KPBZ 170221
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
921 PM EST TUE DEC 16 2014

.SYNOPSIS...
SHOWERS WILL DIMINISH OVERNIGHT AS COLDER AIR MOVES INTO THE
REGION.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
DEFORMATION ALONG THE 700 MB FRONTAL ZONE SEEMS TO BE DRIVING A
SECONDARY INCREASE IN SHOWER ACTIVITY AS THE 700-500 MB COLD POOL
FRONT EDGE DRIVES SOUTHEASTWARD INTO EASTERN OHIO TOWARD THE
PANHANDLE OF WEST VIRGINIA. THIS SHOULD SECONDARILY INCREASE
SHOWERS ACROSS THE AREA AGAIN AS THE EVENING WEARS ON.

COLD ADVECTION GETS RAMPED UP OVER THE ENTIRE AREA
OVERNIGHT...HOWEVER SIGNIFICANTLY COLDER AIR LAGS THE SURFACE
FRONT FROM HUNDREDS OF MILES...AND IS LIKELY TRULY BOTTLED UP
BEHIND A SECONDARY COLD BOUNDARY OVER THE LOWER OHIO VALLEY AND
WESTERN GREAT LAKES. THIS WILL ALLOW FOR MUCH OF THE NIGHT TO
CONTINUE WITH TEMPERATURES ONLY SLOWLY FALLING. IT WILL ALSO
PRECLUDE MUCH OF ANYTHING BUT LIQUID PHASE HYDROMETEORS IN THE
CWA.

LOOKING AT BOTH THE NAM AND GFS OUTPUT...SURFACE TEMPERATURES EVEN
IN THE RIDGES WILL TAKE UNTIL SUNRISE TO COME CLOSE TO FREEZING.
THIS WILL SLOW ANY CHANGEOVER TO SNOW AS THE MOIST LAYER LEANS
OUT...AND ICE MICROPHYSICS BECOME PROBLEMATIC TO SNOW CRYSTAL
GROWTH. AS SUCH...IT WOULD SEEM IT SHOULD BE DAYTIME BEFORE ANY
SNOW IS REALLY NOTED IN THE CWA...AND EVEN THEN...IT IS UNLIKELY
TO BE PARTICULARLY EFFICIENT AT ACCUMULATING DUE TO POOR DENDRITIC
GROWTH ZONE SATURATION.

ADVECTION THROUGH THE NIGHT AND INTO THE DAY ON WEDNESDAY SHOULD
ALLOW FOR A RELATIVELY NON-DIURNAL TEMPERATURE CURVE ON WEDNESDAY.
TEMPERATURES WERE ADJUSTED TO ALLOW FOR LOWER AFTERNOON
TEMPERATURES WITH MORNING HIGHS AS A RESULT. FRIES

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS STORM SYSTEM WINDS UP OFFSHORE NEW ENGLAND THURSDAY FLOW WILL
TURN NORTHWEST FOR A TIME WITH SNOW SHOWER CHANCES INCREASING
ACROSS THE NORTH INTO THE RIDGES. AGAIN INVERSION HEIGHTS LOOK
LOW ON FORECAST SOUNDINGS SO ONLY CHANCE POPS WITH A LIGHT
ACCUMULATION. THURSDAY NIGHT INTO FRIDAY A FAST MOVING SHORTWAVE
WILL SLIDE EAST IN DEVELOPING ZONAL FLOW. ADDED SCATTERED FLURRIES
WITH CONTINUED COLD TEMPERATURES.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPR TROF MOVG OUT OF THE CNTRL CONUS WL RTN PCPN CHCS FOR THE
WEEKEND.  CHC POPS WERE MAINTAINED WITH UNCERTAINTY IN NRN EXTENT OF
ANY PCPN AND THE TRACK OF THE ATTENDANT SFC LOW.  SEASONAL TEMPS
WERE FORECAST CLOSE TO WPC GUIDANCE.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
EXPECT CIGS TO DROP TO IFR FOR MOST LOCATIONS LATER THIS
EVENING/OVERNIGHT IN THE WAKE OF THE FIRST FRONTAL BOUNDARY. SHRA
COVERAGE WILL DECREASE WITH TIME.  WINDS WILL CONTINUE TO GUST TO
BETWEEN 15-20 KNOTS FOR A TIME AS WELL...WITH A SLOW VEER TO THE
WEST PROGRESSING. CIGS WILL BEGIN TO IMPROVE AFTER 12Z...LIFTING
TO MVFR. REINFORCING COLD FROPA WILL KEEP WEST WINDS GUSTING TO
BETWEEN 15 AND 25 KNOTS DURING THE LATE MORNING AND AFTERNOON...AS
WELL AS TURNING OVER ANY LINGERING SCATTERED SHRA TO SHSN.  HIGH
MVFR/LOW VFR STRATOCU ARE FORECAST DURING THE AFTERNOON...WITH A
MODEST INCREASE IN SHSN COVERAGE ACROSS THE LAKE EFFECT SNOW BELT
NEAR FKL/DUJ.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC RSTRN POTENTIAL WL CONT FOR THE RMNDR OF THE WEEK WITH
STRATOCU AND THE APCH OF MORE SUBSTANTIAL LOW PRES ON SATURDAY.

&&

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

&&

$$







000
FXUS61 KPBZ 170221
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
921 PM EST TUE DEC 16 2014

.SYNOPSIS...
SHOWERS WILL DIMINISH OVERNIGHT AS COLDER AIR MOVES INTO THE
REGION.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
DEFORMATION ALONG THE 700 MB FRONTAL ZONE SEEMS TO BE DRIVING A
SECONDARY INCREASE IN SHOWER ACTIVITY AS THE 700-500 MB COLD POOL
FRONT EDGE DRIVES SOUTHEASTWARD INTO EASTERN OHIO TOWARD THE
PANHANDLE OF WEST VIRGINIA. THIS SHOULD SECONDARILY INCREASE
SHOWERS ACROSS THE AREA AGAIN AS THE EVENING WEARS ON.

COLD ADVECTION GETS RAMPED UP OVER THE ENTIRE AREA
OVERNIGHT...HOWEVER SIGNIFICANTLY COLDER AIR LAGS THE SURFACE
FRONT FROM HUNDREDS OF MILES...AND IS LIKELY TRULY BOTTLED UP
BEHIND A SECONDARY COLD BOUNDARY OVER THE LOWER OHIO VALLEY AND
WESTERN GREAT LAKES. THIS WILL ALLOW FOR MUCH OF THE NIGHT TO
CONTINUE WITH TEMPERATURES ONLY SLOWLY FALLING. IT WILL ALSO
PRECLUDE MUCH OF ANYTHING BUT LIQUID PHASE HYDROMETEORS IN THE
CWA.

LOOKING AT BOTH THE NAM AND GFS OUTPUT...SURFACE TEMPERATURES EVEN
IN THE RIDGES WILL TAKE UNTIL SUNRISE TO COME CLOSE TO FREEZING.
THIS WILL SLOW ANY CHANGEOVER TO SNOW AS THE MOIST LAYER LEANS
OUT...AND ICE MICROPHYSICS BECOME PROBLEMATIC TO SNOW CRYSTAL
GROWTH. AS SUCH...IT WOULD SEEM IT SHOULD BE DAYTIME BEFORE ANY
SNOW IS REALLY NOTED IN THE CWA...AND EVEN THEN...IT IS UNLIKELY
TO BE PARTICULARLY EFFICIENT AT ACCUMULATING DUE TO POOR DENDRITIC
GROWTH ZONE SATURATION.

ADVECTION THROUGH THE NIGHT AND INTO THE DAY ON WEDNESDAY SHOULD
ALLOW FOR A RELATIVELY NON-DIURNAL TEMPERATURE CURVE ON WEDNESDAY.
TEMPERATURES WERE ADJUSTED TO ALLOW FOR LOWER AFTERNOON
TEMPERATURES WITH MORNING HIGHS AS A RESULT. FRIES

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS STORM SYSTEM WINDS UP OFFSHORE NEW ENGLAND THURSDAY FLOW WILL
TURN NORTHWEST FOR A TIME WITH SNOW SHOWER CHANCES INCREASING
ACROSS THE NORTH INTO THE RIDGES. AGAIN INVERSION HEIGHTS LOOK
LOW ON FORECAST SOUNDINGS SO ONLY CHANCE POPS WITH A LIGHT
ACCUMULATION. THURSDAY NIGHT INTO FRIDAY A FAST MOVING SHORTWAVE
WILL SLIDE EAST IN DEVELOPING ZONAL FLOW. ADDED SCATTERED FLURRIES
WITH CONTINUED COLD TEMPERATURES.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPR TROF MOVG OUT OF THE CNTRL CONUS WL RTN PCPN CHCS FOR THE
WEEKEND.  CHC POPS WERE MAINTAINED WITH UNCERTAINTY IN NRN EXTENT OF
ANY PCPN AND THE TRACK OF THE ATTENDANT SFC LOW.  SEASONAL TEMPS
WERE FORECAST CLOSE TO WPC GUIDANCE.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
EXPECT CIGS TO DROP TO IFR FOR MOST LOCATIONS LATER THIS
EVENING/OVERNIGHT IN THE WAKE OF THE FIRST FRONTAL BOUNDARY. SHRA
COVERAGE WILL DECREASE WITH TIME.  WINDS WILL CONTINUE TO GUST TO
BETWEEN 15-20 KNOTS FOR A TIME AS WELL...WITH A SLOW VEER TO THE
WEST PROGRESSING. CIGS WILL BEGIN TO IMPROVE AFTER 12Z...LIFTING
TO MVFR. REINFORCING COLD FROPA WILL KEEP WEST WINDS GUSTING TO
BETWEEN 15 AND 25 KNOTS DURING THE LATE MORNING AND AFTERNOON...AS
WELL AS TURNING OVER ANY LINGERING SCATTERED SHRA TO SHSN.  HIGH
MVFR/LOW VFR STRATOCU ARE FORECAST DURING THE AFTERNOON...WITH A
MODEST INCREASE IN SHSN COVERAGE ACROSS THE LAKE EFFECT SNOW BELT
NEAR FKL/DUJ.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC RSTRN POTENTIAL WL CONT FOR THE RMNDR OF THE WEEK WITH
STRATOCU AND THE APCH OF MORE SUBSTANTIAL LOW PRES ON SATURDAY.

&&

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

&&

$$








000
FXUS61 KPBZ 162347
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
647 PM EST TUE DEC 16 2014

.SYNOPSIS...
SHOWERS WILL DIMINISH OVERNIGHT AS COLDER AIR MOVES INTO THE
REGION.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
SHOWERS IN PRE-FRONTAL SHOWERS CONTINUE TO COVER MUCH OF
PENNSYLVANIA EARLY THIS EVENING...WHILE THE PATTERN IS ALREADY
STARTING TO SHIFT TO OUR WEST. THE SURFACE COLD FRONT SEEMS TO BE
SLICING THROUGH THE AREA...WITH THE 700 MB FRONT LAGGING A BIT.
DEFORMATION ALONG THIS FRONTAL BAND SEEMS TO BE DRIVING A
SECONDARY INCREASE IN SHOWER ACTIVITY AS THE 700-500 MB COLD POOL
FRONT EDGE DRIVES SOUTHEASTWARD INTO OHIO. THIS SHOULD SECONDARILY
INCREASE SHOWERS ACROSS THE AREA AGAIN AS THE EVENING WEARS ON.

COLD ADVECTION GETS RAMPED UP OVER THE ENTIRE AREA
OVERNIGHT...HOWEVER SIGNIFICANTLY COLDER AIR LAGS THE SURFACE
FRONT FROM HUNDREDS OF MILES...AND IS LIKELY TRULY BOTTLED UP
BEHIND A SECONDARY COLD BOUNDARY OVER THE LOWER OHIO VALLEY AND
WESTERN GREAT LAKES. THIS WILL ALLOW FOR MUCH OF THE NIGHT TO
CONTINUE WITH TEMPERATURES ONLY SLOWLY FALLING. IT WILL ALSO
PRECLUDE MUCH OF ANYTHING BUT LIQUID PHASE HYDROMETEORS IN THE
CWA.

LOOKING AT BOTH THE NAM AND GFS OUTPUT...SURFACE TEMPERATURES EVEN
IN THE RIDGES WILL TAKE UNTIL SUNRISE TO COME CLOSE TO FREEZING.
THIS WILL SLOW ANY CHANGEOVER TO SNOW AS THE MOIST LAYER LEANS
OUT...AND ICE MICROPHYSICS BECOME PROBLEMATIC TO SNOW CRYSTAL
GROWTH. AS SUCH...IT WOULD SEEM IT SHOULD BE DAYTIME BEFORE ANY
SNOW IS REALLY NOTED IN THE CWA...AND EVEN THEN...IT IS UNLIKELY
TO BE PARTICULARLY EFFICIENT AT ACCUMULATING DUE TO POOR DENDRITIC
GROWTH ZONE SATURATION.

ADVECTION THROUGH THE NIGHT AND INTO THE DAY ON WEDNESDAY SHOULD
ALLOW FOR A RELATIVELY NON-DIURNAL TEMPERATURE CURVE ON WEDNESDAY.
TEMPERATURES WERE ADJUSTED TO ALLOW FOR LOWER AFTERNOON
TEMPERATURES WITH MORNING HIGHS AS A RESULT. FRIES

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS STORM SYSTEM WINDS UP OFFSHORE NEW ENGLAND THURSDAY FLOW WILL
TURN NORTHWEST FOR A TIME WITH SNOW SHOWER CHANCES INCREASING
ACROSS THE NORTH INTO THE RIDGES. AGAIN INVERSION HEIGHTS LOOK
LOW ON FORECAST SOUNDINGS SO ONLY CHANCE POPS WITH A LIGHT
ACCUMULATION. THURSDAY NIGHT INTO FRIDAY A FAST MOVING SHORTWAVE
WILL SLIDE EAST IN DEVELOPING ZONAL FLOW. ADDED SCATTERED FLURRIES
WITH CONTINUED COLD TEMPERATURES.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPR TROF MOVG OUT OF THE CNTRL CONUS WL RTN PCPN CHCS FOR THE
WEEKEND.  CHC POPS WERE MAINTAINED WITH UNCERTAINTY IN NRN EXTENT OF
ANY PCPN AND THE TRACK OF THE ATTENDANT SFC LOW.  SEASONAL TEMPS
WERE FORECAST CLOSE TO WPC GUIDANCE.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
EXPECT CIGS TO DROP TO IFR FOR MOST LOCATIONS LATER THIS
EVENING/OVERNIGHT IN THE WAKE OF THE FIRST FRONTAL BOUNDARY. SHRA
COVERAGE WILL DECREASE WITH TIME.  WINDS WILL CONTINUE TO GUST TO
BETWEEN 15-20 KNOTS FOR A TIME AS WELL...WITH A SLOW VEER TO THE
WEST PROGRESSING. CIGS WILL BEGIN TO IMPROVE AFTER 12Z...LIFTING
TO MVFR. REINFORCING COLD FROPA WILL KEEP WEST WINDS GUSTING TO
BETWEEN 15 AND 25 KNOTS DURING THE LATE MORNING AND AFTERNOON...AS
WELL AS TURNING OVER ANY LINGERING SCATTERED SHRA TO SHSN.  HIGH
MVFR/LOW VFR STRATOCU ARE FORECAST DURING THE AFTERNOON...WITH A
MODEST INCREASE IN SHSN COVERAGE ACROSS THE LAKE EFFECT SNOW BELT
NEAR FKL/DUJ.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC RSTRN POTENTIAL WL CONT FOR THE RMNDR OF THE WEEK WITH
STRATOCU AND THE APCH OF MORE SUBSTANTIAL LOW PRES ON SATURDAY.

&&

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

&&

$$







000
FXUS61 KPBZ 162347
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
647 PM EST TUE DEC 16 2014

.SYNOPSIS...
SHOWERS WILL DIMINISH OVERNIGHT AS COLDER AIR MOVES INTO THE
REGION.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
SHOWERS IN PRE-FRONTAL SHOWERS CONTINUE TO COVER MUCH OF
PENNSYLVANIA EARLY THIS EVENING...WHILE THE PATTERN IS ALREADY
STARTING TO SHIFT TO OUR WEST. THE SURFACE COLD FRONT SEEMS TO BE
SLICING THROUGH THE AREA...WITH THE 700 MB FRONT LAGGING A BIT.
DEFORMATION ALONG THIS FRONTAL BAND SEEMS TO BE DRIVING A
SECONDARY INCREASE IN SHOWER ACTIVITY AS THE 700-500 MB COLD POOL
FRONT EDGE DRIVES SOUTHEASTWARD INTO OHIO. THIS SHOULD SECONDARILY
INCREASE SHOWERS ACROSS THE AREA AGAIN AS THE EVENING WEARS ON.

COLD ADVECTION GETS RAMPED UP OVER THE ENTIRE AREA
OVERNIGHT...HOWEVER SIGNIFICANTLY COLDER AIR LAGS THE SURFACE
FRONT FROM HUNDREDS OF MILES...AND IS LIKELY TRULY BOTTLED UP
BEHIND A SECONDARY COLD BOUNDARY OVER THE LOWER OHIO VALLEY AND
WESTERN GREAT LAKES. THIS WILL ALLOW FOR MUCH OF THE NIGHT TO
CONTINUE WITH TEMPERATURES ONLY SLOWLY FALLING. IT WILL ALSO
PRECLUDE MUCH OF ANYTHING BUT LIQUID PHASE HYDROMETEORS IN THE
CWA.

LOOKING AT BOTH THE NAM AND GFS OUTPUT...SURFACE TEMPERATURES EVEN
IN THE RIDGES WILL TAKE UNTIL SUNRISE TO COME CLOSE TO FREEZING.
THIS WILL SLOW ANY CHANGEOVER TO SNOW AS THE MOIST LAYER LEANS
OUT...AND ICE MICROPHYSICS BECOME PROBLEMATIC TO SNOW CRYSTAL
GROWTH. AS SUCH...IT WOULD SEEM IT SHOULD BE DAYTIME BEFORE ANY
SNOW IS REALLY NOTED IN THE CWA...AND EVEN THEN...IT IS UNLIKELY
TO BE PARTICULARLY EFFICIENT AT ACCUMULATING DUE TO POOR DENDRITIC
GROWTH ZONE SATURATION.

ADVECTION THROUGH THE NIGHT AND INTO THE DAY ON WEDNESDAY SHOULD
ALLOW FOR A RELATIVELY NON-DIURNAL TEMPERATURE CURVE ON WEDNESDAY.
TEMPERATURES WERE ADJUSTED TO ALLOW FOR LOWER AFTERNOON
TEMPERATURES WITH MORNING HIGHS AS A RESULT. FRIES

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS STORM SYSTEM WINDS UP OFFSHORE NEW ENGLAND THURSDAY FLOW WILL
TURN NORTHWEST FOR A TIME WITH SNOW SHOWER CHANCES INCREASING
ACROSS THE NORTH INTO THE RIDGES. AGAIN INVERSION HEIGHTS LOOK
LOW ON FORECAST SOUNDINGS SO ONLY CHANCE POPS WITH A LIGHT
ACCUMULATION. THURSDAY NIGHT INTO FRIDAY A FAST MOVING SHORTWAVE
WILL SLIDE EAST IN DEVELOPING ZONAL FLOW. ADDED SCATTERED FLURRIES
WITH CONTINUED COLD TEMPERATURES.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPR TROF MOVG OUT OF THE CNTRL CONUS WL RTN PCPN CHCS FOR THE
WEEKEND.  CHC POPS WERE MAINTAINED WITH UNCERTAINTY IN NRN EXTENT OF
ANY PCPN AND THE TRACK OF THE ATTENDANT SFC LOW.  SEASONAL TEMPS
WERE FORECAST CLOSE TO WPC GUIDANCE.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
EXPECT CIGS TO DROP TO IFR FOR MOST LOCATIONS LATER THIS
EVENING/OVERNIGHT IN THE WAKE OF THE FIRST FRONTAL BOUNDARY. SHRA
COVERAGE WILL DECREASE WITH TIME.  WINDS WILL CONTINUE TO GUST TO
BETWEEN 15-20 KNOTS FOR A TIME AS WELL...WITH A SLOW VEER TO THE
WEST PROGRESSING. CIGS WILL BEGIN TO IMPROVE AFTER 12Z...LIFTING
TO MVFR. REINFORCING COLD FROPA WILL KEEP WEST WINDS GUSTING TO
BETWEEN 15 AND 25 KNOTS DURING THE LATE MORNING AND AFTERNOON...AS
WELL AS TURNING OVER ANY LINGERING SCATTERED SHRA TO SHSN.  HIGH
MVFR/LOW VFR STRATOCU ARE FORECAST DURING THE AFTERNOON...WITH A
MODEST INCREASE IN SHSN COVERAGE ACROSS THE LAKE EFFECT SNOW BELT
NEAR FKL/DUJ.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC RSTRN POTENTIAL WL CONT FOR THE RMNDR OF THE WEEK WITH
STRATOCU AND THE APCH OF MORE SUBSTANTIAL LOW PRES ON SATURDAY.

&&

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

&&

$$








000
FXUS61 KPBZ 162241
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
541 PM EST TUE DEC 16 2014

.SYNOPSIS...
SHOWERS WILL DIMINISH OVERNIGHT AS COLDER AIR MOVES INTO THE
REGION.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
SHOWERS IN PRE-FRONTAL SHOWERS CONTINUE TO COVER MUCH OF
PENNSYLVANIA EARLY THIS EVENING...WHILE THE PATTERN IS ALREADY
STARTING TO SHIFT TO OUR WEST. THE SURFACE COLD FRONT SEEMS TO BE
SLICING THROUGH THE AREA...WITH THE 700 MB FRONT LAGGING A BIT.
DEFORMATION ALONG THIS FRONTAL BAND SEEMS TO BE DRIVING A
SECONDARY INCREASE IN SHOWER ACTIVITY AS THE 700-500 MB COLD POOL
FRONT EDGE DRIVES SOUTHEASTWARD INTO OHIO. THIS SHOULD SECONDARILY
INCREASE SHOWERS ACROSS THE AREA AGAIN AS THE EVENING WEARS ON.

COLD ADVECTION GETS RAMPED UP OVER THE ENTIRE AREA
OVERNIGHT...HOWEVER SIGNIFICANTLY COLDER AIR LAGS THE SURFACE
FRONT FROM HUNDREDS OF MILES...AND IS LIKELY TRULY BOTTLED UP
BEHIND A SECONDARY COLD BOUNDARY OVER THE LOWER OHIO VALLEY AND
WESTERN GREAT LAKES. THIS WILL ALLOW FOR MUCH OF THE NIGHT TO
CONTINUE WITH TEMPERATURES ONLY SLOWLY FALLING. IT WILL ALSO
PRECLUDE MUCH OF ANYTHING BUT LIQUID PHASE HYDROMETEORS IN THE
CWA.

LOOKING AT BOTH THE NAM AND GFS OUTPUT...SURFACE TEMPERATURES EVEN
IN THE RIDGES WILL TAKE UNTIL SUNRISE TO COME CLOSE TO FREEZING.
THIS WILL SLOW ANY CHANGEOVER TO SNOW AS THE MOIST LAYER LEANS
OUT...AND ICE MICROPHYSICS BECOME PROBLEMATIC TO SNOW CRYSTAL
GROWTH. AS SUCH...IT WOULD SEEM IT SHOULD BE DAYTIME BEFORE ANY
SNOW IS REALLY NOTED IN THE CWA...AND EVEN THEN...IT IS UNLIKELY
TO BE PARTICULARLY EFFICIENT AT ACCUMULATING DUE TO POOR DENDRITIC
GROWTH ZONE SATURATION.

ADVECTION THROUGH THE NIGHT AND INTO THE DAY ON WEDNESDAY SHOULD
ALLOW FOR A RELATIVELY NON-DIURNAL TEMPERATURE CURVE ON WEDNESDAY.
TEMPERATURES WERE ADJUSTED TO ALLOW FOR LOWER AFTERNOON
TEMPERATURES WITH MORNING HIGHS AS A RESULT. FRIES

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS STORM SYSTEM WINDS UP OFFSHORE NEW ENGLAND THURSDAY FLOW WILL
TURN NORTHWEST FOR A TIME WITH SNOW SHOWER CHANCES INCREASING
ACROSS THE NORTH INTO THE RIDGES. AGAIN INVERSION HEIGHTS LOOK
LOW ON FORECAST SOUNDINGS SO ONLY CHANCE POPS WITH A LIGHT
ACCUMULATION. THURSDAY NIGHT INTO FRIDAY A FAST MOVING SHORTWAVE
WILL SLIDE EAST IN DEVELOPING ZONAL FLOW. ADDED SCATTERED FLURRIES
WITH CONTINUED COLD TEMPERATURES.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPR TROF MOVG OUT OF THE CNTRL CONUS WL RTN PCPN CHCS FOR THE
WEEKEND.  CHC POPS WERE MAINTAINED WITH UNCERTAINTY IN NRN EXTENT OF
ANY PCPN AND THE TRACK OF THE ATTENDANT SFC LOW.  SEASONAL TEMPS
WERE FORECAST CLOSE TO WPC GUIDANCE.

&&

.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
CONDITION DETERIORATION TO LOW END MVFR AND EVENTUAL IFR WL CONT TDA
WITH SHWRS AND RELATIVE  SATURATION WITH PASSAGE OF THE ADVNG
CDFNT.  IN ADDITION...SFC WIND WL VEER TO THE WEST BY EVE WITH
INITIAL GUSTS NR 20 KTS.  IMPROVEMENT CAN BE EXPECTED
WEDNESDAY...BUT THE SHRTWV CROSSING THE GREAT LAKES WL REINFORCE THE
MIXING LYR VIA COLD ADVCTN...HENCE MVFR STRATOCU SHOULD QUICKLY RTN
TO MOST PORTS AS EVE APCHS.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC RSTRN POTENTIAL WL CONT FOR THE RMNDR OF THE WEEK WITH
STRATOCU AND THE APCH OF MORE SUBSTANTIAL LOW PRES ON SATURDAY.

&&

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

&&

$$







000
FXUS61 KPBZ 162011
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
311 PM EST TUE DEC 16 2014

.SYNOPSIS...
SHOWERS WILL DIMINISH OVERNIGHT AS COLDER AIR MOVES INTO THE
REGION.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
SURFACE BOUNDARY AND SHORTWAVE WORK ACROSS THE REGION THIS EVENING
WITH SHOWERS DIMINISHING OVERNIGHT INTO EARLY WEDNESDAY. COLD
ADVECTION WILL DROP TEMPERATURES LATER TONIGHT AND WEDNESDAY
TOWARD MORE SEASONAL LEVELS. WITH THE COLD AIR RAIN SHOWERS WILL
MIX WITH SNOW BEFORE ENDING WEDNESDAY MORNING. THE EXCEPTIONS WILL
BE THE RIDGES AND THE I-80 CORRIDOR WHERE 850MB TEMPS FALLING TO
-10C BY LATE DAY WEDNESDAY WILL ALLOW FOR SOME LAKE ENHANCED SNOW
SHOWERS...BUT LOW INVERSION HEIGHTS AND A WESTERLY FLOW WILL KEEP
ONLY CHANCE POPS AND LITTLE ACCUMULATION. STILL POSSIBLE FOR A BIT
OF FREEZING DRIZZLE IN THE HIGHER RIDGES WITH SHALLOW COLD AIR
EARLY WEDNESDAY BUT WITH COLUMN DRYING WAS LEFT OUT FOR NOW.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS STORM SYSTEM WINDS UP OFFSHORE NEW ENGLAND THURSDAY FLOW WILL
TURN NORTHWEST FOR A TIME WITH SNOW SHOWER CHANCES INCREASING
ACROSS THE NORTH INTO THE RIDGES. AGAIN INVERSION HEIGHTS LOOK
LOW ON FORECAST SOUNDINGS SO ONLY CHANCE POPS WITH A LIGHT
ACCUMULATION. THURSDAY NIGHT INTO FRIDAY A FAST MOVING SHORTWAVE
WILL SLIDE EAST IN DEVELOPING ZONAL FLOW. ADDED SCATTERED FLURRIES
WITH CONTINUED COLD TEMPERATURES.


&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPR TROF MOVG OUT OF THE CNTRL CONUS WL RTN PCPN CHCS FOR THE
WEEKEND.  CHC POPS WERE MAINTAINED WITH UNCERTAINTY IN NRN EXTENT OF
ANY PCPN AND THE TRACK OF THE ATTENDANT SFC LOW.  SEASONAL TEMPS
WERE FORECAST CLOSE TO WPC GUIDANCE.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
CONDITION DETERIORATION TO LOW END MVFR AND EVENTUAL IFR WL CONT TDA
WITH SHWRS AND RELATIVE  SATURATION WITH PASSAGE OF THE ADVNG
CDFNT.  IN ADDITION...SFC WIND WL VEER TO THE WEST BY EVE WITH
INITIAL GUSTS NR 20 KTS.  IMPROVEMENT CAN BE EXPECTED
WEDNESDAY...BUT THE SHRTWV CROSSING THE GREAT LAKES WL REINFORCE THE
MIXING LYR VIA COLD ADVCTN...HENCE MVFR STRATOCU SHOULD QUICKLY RTN
TO MOST PORTS AS EVE APCHS.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC RSTRN POTENTIAL WL CONT FOR THE RMNDR OF THE WEEK WITH
STRATOCU AND THE APCH OF MORE SUBSTANTIAL LOW PRES ON SATURDAY.

&&

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

&&

$$











000
FXUS61 KPBZ 162011
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
311 PM EST TUE DEC 16 2014

.SYNOPSIS...
SHOWERS WILL DIMINISH OVERNIGHT AS COLDER AIR MOVES INTO THE
REGION.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
SURFACE BOUNDARY AND SHORTWAVE WORK ACROSS THE REGION THIS EVENING
WITH SHOWERS DIMINISHING OVERNIGHT INTO EARLY WEDNESDAY. COLD
ADVECTION WILL DROP TEMPERATURES LATER TONIGHT AND WEDNESDAY
TOWARD MORE SEASONAL LEVELS. WITH THE COLD AIR RAIN SHOWERS WILL
MIX WITH SNOW BEFORE ENDING WEDNESDAY MORNING. THE EXCEPTIONS WILL
BE THE RIDGES AND THE I-80 CORRIDOR WHERE 850MB TEMPS FALLING TO
-10C BY LATE DAY WEDNESDAY WILL ALLOW FOR SOME LAKE ENHANCED SNOW
SHOWERS...BUT LOW INVERSION HEIGHTS AND A WESTERLY FLOW WILL KEEP
ONLY CHANCE POPS AND LITTLE ACCUMULATION. STILL POSSIBLE FOR A BIT
OF FREEZING DRIZZLE IN THE HIGHER RIDGES WITH SHALLOW COLD AIR
EARLY WEDNESDAY BUT WITH COLUMN DRYING WAS LEFT OUT FOR NOW.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
AS STORM SYSTEM WINDS UP OFFSHORE NEW ENGLAND THURSDAY FLOW WILL
TURN NORTHWEST FOR A TIME WITH SNOW SHOWER CHANCES INCREASING
ACROSS THE NORTH INTO THE RIDGES. AGAIN INVERSION HEIGHTS LOOK
LOW ON FORECAST SOUNDINGS SO ONLY CHANCE POPS WITH A LIGHT
ACCUMULATION. THURSDAY NIGHT INTO FRIDAY A FAST MOVING SHORTWAVE
WILL SLIDE EAST IN DEVELOPING ZONAL FLOW. ADDED SCATTERED FLURRIES
WITH CONTINUED COLD TEMPERATURES.


&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPR TROF MOVG OUT OF THE CNTRL CONUS WL RTN PCPN CHCS FOR THE
WEEKEND.  CHC POPS WERE MAINTAINED WITH UNCERTAINTY IN NRN EXTENT OF
ANY PCPN AND THE TRACK OF THE ATTENDANT SFC LOW.  SEASONAL TEMPS
WERE FORECAST CLOSE TO WPC GUIDANCE.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
CONDITION DETERIORATION TO LOW END MVFR AND EVENTUAL IFR WL CONT TDA
WITH SHWRS AND RELATIVE  SATURATION WITH PASSAGE OF THE ADVNG
CDFNT.  IN ADDITION...SFC WIND WL VEER TO THE WEST BY EVE WITH
INITIAL GUSTS NR 20 KTS.  IMPROVEMENT CAN BE EXPECTED
WEDNESDAY...BUT THE SHRTWV CROSSING THE GREAT LAKES WL REINFORCE THE
MIXING LYR VIA COLD ADVCTN...HENCE MVFR STRATOCU SHOULD QUICKLY RTN
TO MOST PORTS AS EVE APCHS.

OUTLOOK.../TUESDAY NIGHT THROUGH SUNDAY/...
PERIODIC RSTRN POTENTIAL WL CONT FOR THE RMNDR OF THE WEEK WITH
STRATOCU AND THE APCH OF MORE SUBSTANTIAL LOW PRES ON SATURDAY.

&&

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

&&

$$












000
FXUS61 KPBZ 161825
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
125 PM EST TUE DEC 16 2014

.SYNOPSIS...
LOW PRESSURE WILL BRING SHOWERS THIS AFTERNOON WITH COOLER
TEMPERATURES WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MID AFTERNOON UPDATE TO ADJUST MAX AND HOURLY TEMPS.

LOW PRESSURE CROSSING MICHIGAN THIS AFTERNOON AS UPPER TROUGH
MOVES EAST. SURFACE WIND SHIFT ACROSS CENTRAL OHIO WITH THE
BEGINNING OF COLD ADVECTION WILL WORK ACROSS THE REGION BY LATE
AFTERNOON. LIKELY POPS FOR MAINLY LIGHT RAIN SHOWERS. CURRENT
TEMPERATURES WILL BE CLOSE TO MAX TEMPS TODAY WITH A SMALL FALL
OFF LATE AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
UPPER TROUGH AXIS SWINGS THROUGH THIS EVENING...KEEPING POPS HIGH
UNTIL ITS EXIT. BEHIND THE EXITING TROUGH...SHOWER COVERAGE WILL
DECREASE AND CAA WILL BEGIN AS WINDS VEER TO THE WEST AND PULL THE
COLDER AIR EASTWARD. THE CAA WILL START SLOW TONIGHT BUT WILL RAMP
UP ON WEDNESDAY. EXPECT SNOW SHOWERS TO DEVELOP WITH THE COLDER
AIR...PARTICULARLY OVER THE NORTH AND RIDGES. INVERSIONS WILL
LOWER RATHER QUICKLY...BUT SO WILL THE SNOW GROWTH ZONE. WILL KEEP
THE POPS FOR SNOW MOSTLY OVER THE AFOREMENTIONED AREAS WED
AFTERNOON/NIGHT.

ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH WEDNESDAY NIGHT...
PROVIDING ANOTHER PUSH OF COLDER AIR AND VEER THE WINDS FURTHER
TO THE NORTHWEST. THIS COULD PROVIDE A BRIEF EXPANSION OF SNOW
SHOWER COVERAGE...BUT WITH INVERSIONS SO LOW IT WILL NOT BE A
LARGE EXPANSION.

ON THURSDAY...THE COLD AIR WILL BE SHOVED NORTHEASTWARD AS A WEAK
RIDGE DRIFTS THROUGH THE MIDWEST. AT THE SURFACE...HIGH PRESSURE
WILL BUILD INTO SOUTHERN OHIO WHICH WILL EVENTUALLY CONFINE THE
SNOW SHOWER RISK TO THE NORTH.

NOTICEABLY COLDER TEMPS ON THURSDAY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AN UPR TROF MOVG OUT OF THE CNTRL CONUS WL RTN PCPN CHCS FOR THE
WEEKEND.  CHC POPS WERE MAINTAINED WITH UNCERTAINTY IN NRN EXTENT OF
ANY PCPN AND THE TRACK OF THE ATTENDANT SFC LOW.  SEASONAL TEMPS
WERE FORECAST CLOSE TO WPC GUIDANCE.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
CONDITION DETERIORATION TO LOW END MVFR AND EVENTUAL IFR WL CONT TDA
WITH SHWRS AND RELATIVE  SATURATION WITH PASSAGE OF THE ADVNG
CDFNT.  IN ADDITION...SFC WIND WL VEER TO THE WEST BY EVE WITH
INITIAL GUSTS NR 20 KTS.  IMPROVEMENT CAN BE EXPECTED
WEDNESDAY...BUT THE SHRTWV CROSSING THE GREAT LAKES WL REINFORCE THE
MIXING LYR VIA COLD ADVCTN...HENCE MVFR STRATOCU SHOULD QUICKLY RTN
TO MOST PORTS AS EVE APCHS.

OUTLOOK.../TUESDAY NIGHT THROUGH SATURDAY/...
PERIODIC RSTRN POTENTIAL WL CONT FOR THE RMNDR OF THE WEEK WITH
STRATOCU AND THE APCH OF MORE SUBSTANTIAL LOW PRES ON SATURDAY.

&&

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

&&

$$









000
FXUS61 KPBZ 161825
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
125 PM EST TUE DEC 16 2014

.SYNOPSIS...
LOW PRESSURE WILL BRING SHOWERS THIS AFTERNOON WITH COOLER
TEMPERATURES WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MID AFTERNOON UPDATE TO ADJUST MAX AND HOURLY TEMPS.

LOW PRESSURE CROSSING MICHIGAN THIS AFTERNOON AS UPPER TROUGH
MOVES EAST. SURFACE WIND SHIFT ACROSS CENTRAL OHIO WITH THE
BEGINNING OF COLD ADVECTION WILL WORK ACROSS THE REGION BY LATE
AFTERNOON. LIKELY POPS FOR MAINLY LIGHT RAIN SHOWERS. CURRENT
TEMPERATURES WILL BE CLOSE TO MAX TEMPS TODAY WITH A SMALL FALL
OFF LATE AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
UPPER TROUGH AXIS SWINGS THROUGH THIS EVENING...KEEPING POPS HIGH
UNTIL ITS EXIT. BEHIND THE EXITING TROUGH...SHOWER COVERAGE WILL
DECREASE AND CAA WILL BEGIN AS WINDS VEER TO THE WEST AND PULL THE
COLDER AIR EASTWARD. THE CAA WILL START SLOW TONIGHT BUT WILL RAMP
UP ON WEDNESDAY. EXPECT SNOW SHOWERS TO DEVELOP WITH THE COLDER
AIR...PARTICULARLY OVER THE NORTH AND RIDGES. INVERSIONS WILL
LOWER RATHER QUICKLY...BUT SO WILL THE SNOW GROWTH ZONE. WILL KEEP
THE POPS FOR SNOW MOSTLY OVER THE AFOREMENTIONED AREAS WED
AFTERNOON/NIGHT.

ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH WEDNESDAY NIGHT...
PROVIDING ANOTHER PUSH OF COLDER AIR AND VEER THE WINDS FURTHER
TO THE NORTHWEST. THIS COULD PROVIDE A BRIEF EXPANSION OF SNOW
SHOWER COVERAGE...BUT WITH INVERSIONS SO LOW IT WILL NOT BE A
LARGE EXPANSION.

ON THURSDAY...THE COLD AIR WILL BE SHOVED NORTHEASTWARD AS A WEAK
RIDGE DRIFTS THROUGH THE MIDWEST. AT THE SURFACE...HIGH PRESSURE
WILL BUILD INTO SOUTHERN OHIO WHICH WILL EVENTUALLY CONFINE THE
SNOW SHOWER RISK TO THE NORTH.

NOTICEABLY COLDER TEMPS ON THURSDAY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AN UPR TROF MOVG OUT OF THE CNTRL CONUS WL RTN PCPN CHCS FOR THE
WEEKEND.  CHC POPS WERE MAINTAINED WITH UNCERTAINTY IN NRN EXTENT OF
ANY PCPN AND THE TRACK OF THE ATTENDANT SFC LOW.  SEASONAL TEMPS
WERE FORECAST CLOSE TO WPC GUIDANCE.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
CONDITION DETERIORATION TO LOW END MVFR AND EVENTUAL IFR WL CONT TDA
WITH SHWRS AND RELATIVE  SATURATION WITH PASSAGE OF THE ADVNG
CDFNT.  IN ADDITION...SFC WIND WL VEER TO THE WEST BY EVE WITH
INITIAL GUSTS NR 20 KTS.  IMPROVEMENT CAN BE EXPECTED
WEDNESDAY...BUT THE SHRTWV CROSSING THE GREAT LAKES WL REINFORCE THE
MIXING LYR VIA COLD ADVCTN...HENCE MVFR STRATOCU SHOULD QUICKLY RTN
TO MOST PORTS AS EVE APCHS.

OUTLOOK.../TUESDAY NIGHT THROUGH SATURDAY/...
PERIODIC RSTRN POTENTIAL WL CONT FOR THE RMNDR OF THE WEEK WITH
STRATOCU AND THE APCH OF MORE SUBSTANTIAL LOW PRES ON SATURDAY.

&&

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

&&

$$










000
FXUS61 KPBZ 161611
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1111 AM EST TUE DEC 16 2014

.SYNOPSIS...
LOW PRESSURE WILL BRING SHOWERS THIS AFTERNOON WITH COOLER
TEMPERATURES WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW PRESSURE CROSSING MICHIGAN THIS AFTERNOON AS UPPER TROUGH
MOVES EAST. SURFACE WIND SHIFT ACROSS CENTRAL OHIO WITH THE
BEGINNING OF COLD ADVECTION WILL WORK ACROSS THE REGION BY LATE
AFTERNOON. LIKELY POPS FOR MAINLY LIGHT RAIN SHOWERS. CURRENT
TEMPERATURES WILL BE CLOSE TO MAX TEMPS TODAY WITH A SMALL FALL
OFF LATE AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
UPPER TROUGH AXIS SWINGS THROUGH THIS EVENING...KEEPING POPS HIGH
UNTIL ITS EXIT. BEHIND THE EXITING TROUGH...SHOWER COVERAGE WILL
DECREASE AND CAA WILL BEGIN AS WINDS VEER TO THE WEST AND PULL THE
COLDER AIR EASTWARD. THE CAA WILL START SLOW TONIGHT BUT WILL RAMP
UP ON WEDNESDAY. EXPECT SNOW SHOWERS TO DEVELOP WITH THE COLDER
AIR...PARTICULARLY OVER THE NORTH AND RIDGES. INVERSIONS WILL
LOWER RATHER QUICKLY...BUT SO WILL THE SNOW GROWTH ZONE. WILL KEEP
THE POPS FOR SNOW MOSTLY OVER THE AFOREMENTIONED AREAS WED
AFTERNOON/NIGHT.

ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH WEDNESDAY NIGHT...
PROVIDING ANOTHER PUSH OF COLDER AIR AND VEER THE WINDS FURTHER
TO THE NORTHWEST. THIS COULD PROVIDE A BRIEF EXPANSION OF SNOW
SHOWER COVERAGE...BUT WITH INVERSIONS SO LOW IT WILL NOT BE A
LARGE EXPANSION.

ON THURSDAY...THE COLD AIR WILL BE SHOVED NORTHEASTWARD AS A WEAK
RIDGE DRIFTS THROUGH THE MIDWEST. AT THE SURFACE...HIGH PRESSURE
WILL BUILD INTO SOUTHERN OHIO WHICH WILL EVENTUALLY CONFINE THE
SNOW SHOWER RISK TO THE NORTH.

NOTICEABLY COLDER TEMPS ON THURSDAY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
RIDGING IS PROGGED TO BLD IN THU NGT AND FRI ENDING ANY LINGERING
SNW SHWRS N OF I 80. AN UPR TROF MOVG OUT OF THE CNTRL CONUS...
WITH A DVLPG SERN CONUS SFC LOW...WL RTN PCPN CHCS SAT INTO SUN.
MAINTAINED CHC POPS WITH UNCERTAINTY IN NRN EXTENT OF ANY PCPN AND
THE TRACK OF THE LOW. RIDGING IS PROGGED LTR SUN AND MON. NR
SEASONAL AVG TEMPS ARE EXPD THRU THE PD.

&&

.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
CONDITION DETERIORATION TO LOW END MVFR AND EVENTUAL IFR WL CONT TDA
WITH SHWRS AND RELATIVE  SATURATION WITH PASSAGE OF THE ADVNG
CDFNT.  IN ADDITION...SFC WIND WL VEER TO THE WEST BY EVE WITH
INITIAL GUSTS NR 20 KTS.  IMPROVEMENT CAN BE EXPECTED
WEDNESDAY...BUT THE SHRTWV CROSSING THE GREAT LAKES WL REINFORCE THE
MIXING LYR VIA COLD ADVCTN...HENCE MVFR STRATOCU SHOULD QUICKLY RTN
TO MOST PORTS AS EVE APCHS.

OUTLOOK.../TUESDAY NIGHT THROUGH SATURDAY/...
PERIODIC RSTRN POTENTIAL WL CONT FOR THE RMNDR OF THE WEEK WITH
STRATOCU AND THE APCH OF MORE SUBSTANTIAL LOW PRES ON SATURDAY.

&&

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

&&

$$










000
FXUS61 KPBZ 161611
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1111 AM EST TUE DEC 16 2014

.SYNOPSIS...
LOW PRESSURE WILL BRING SHOWERS THIS AFTERNOON WITH COOLER
TEMPERATURES WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOW PRESSURE CROSSING MICHIGAN THIS AFTERNOON AS UPPER TROUGH
MOVES EAST. SURFACE WIND SHIFT ACROSS CENTRAL OHIO WITH THE
BEGINNING OF COLD ADVECTION WILL WORK ACROSS THE REGION BY LATE
AFTERNOON. LIKELY POPS FOR MAINLY LIGHT RAIN SHOWERS. CURRENT
TEMPERATURES WILL BE CLOSE TO MAX TEMPS TODAY WITH A SMALL FALL
OFF LATE AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
UPPER TROUGH AXIS SWINGS THROUGH THIS EVENING...KEEPING POPS HIGH
UNTIL ITS EXIT. BEHIND THE EXITING TROUGH...SHOWER COVERAGE WILL
DECREASE AND CAA WILL BEGIN AS WINDS VEER TO THE WEST AND PULL THE
COLDER AIR EASTWARD. THE CAA WILL START SLOW TONIGHT BUT WILL RAMP
UP ON WEDNESDAY. EXPECT SNOW SHOWERS TO DEVELOP WITH THE COLDER
AIR...PARTICULARLY OVER THE NORTH AND RIDGES. INVERSIONS WILL
LOWER RATHER QUICKLY...BUT SO WILL THE SNOW GROWTH ZONE. WILL KEEP
THE POPS FOR SNOW MOSTLY OVER THE AFOREMENTIONED AREAS WED
AFTERNOON/NIGHT.

ANOTHER SHORTWAVE TROUGH WILL MOVE THROUGH WEDNESDAY NIGHT...
PROVIDING ANOTHER PUSH OF COLDER AIR AND VEER THE WINDS FURTHER
TO THE NORTHWEST. THIS COULD PROVIDE A BRIEF EXPANSION OF SNOW
SHOWER COVERAGE...BUT WITH INVERSIONS SO LOW IT WILL NOT BE A
LARGE EXPANSION.

ON THURSDAY...THE COLD AIR WILL BE SHOVED NORTHEASTWARD AS A WEAK
RIDGE DRIFTS THROUGH THE MIDWEST. AT THE SURFACE...HIGH PRESSURE
WILL BUILD INTO SOUTHERN OHIO WHICH WILL EVENTUALLY CONFINE THE
SNOW SHOWER RISK TO THE NORTH.

NOTICEABLY COLDER TEMPS ON THURSDAY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
RIDGING IS PROGGED TO BLD IN THU NGT AND FRI ENDING ANY LINGERING
SNW SHWRS N OF I 80. AN UPR TROF MOVG OUT OF THE CNTRL CONUS...
WITH A DVLPG SERN CONUS SFC LOW...WL RTN PCPN CHCS SAT INTO SUN.
MAINTAINED CHC POPS WITH UNCERTAINTY IN NRN EXTENT OF ANY PCPN AND
THE TRACK OF THE LOW. RIDGING IS PROGGED LTR SUN AND MON. NR
SEASONAL AVG TEMPS ARE EXPD THRU THE PD.

&&

.AVIATION /16Z TUESDAY THROUGH SATURDAY/...
CONDITION DETERIORATION TO LOW END MVFR AND EVENTUAL IFR WL CONT TDA
WITH SHWRS AND RELATIVE  SATURATION WITH PASSAGE OF THE ADVNG
CDFNT.  IN ADDITION...SFC WIND WL VEER TO THE WEST BY EVE WITH
INITIAL GUSTS NR 20 KTS.  IMPROVEMENT CAN BE EXPECTED
WEDNESDAY...BUT THE SHRTWV CROSSING THE GREAT LAKES WL REINFORCE THE
MIXING LYR VIA COLD ADVCTN...HENCE MVFR STRATOCU SHOULD QUICKLY RTN
TO MOST PORTS AS EVE APCHS.

OUTLOOK.../TUESDAY NIGHT THROUGH SATURDAY/...
PERIODIC RSTRN POTENTIAL WL CONT FOR THE RMNDR OF THE WEEK WITH
STRATOCU AND THE APCH OF MORE SUBSTANTIAL LOW PRES ON SATURDAY.

&&

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

&&

$$











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