Area Forecast Discussion
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000 FXUS61 KPBZ 282054 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 354 PM EST SUN DEC 28 2014 .SYNOPSIS...
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CLOUDS AND DRIZZLE WILL PERSIST THIS AFTERNOON. A RETURN TO BELOW-NORMAL TEMPERATURES IS EXPECTED MONDAY...WITH UNSEASONABLY COLD AIR EXPECTED ON WEDNESDAY.
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&& .NEAR TERM /THROUGH MONDAY NIGHT/...
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CDFNT HAS PASSED THRU THE RGN AND TAKEN UP RESIDENCE JUST S OF FCST AREA THIS AFTN. A SHRTWV TROF IS MOVING NEWD ALONG THIS BNDRY AND HAS INVIGORATED LGT PCPN IN SRN ZONES...WHICH WILL PERSIST A FEW MORE HRS UNTIL THE WAVE PASSES. AS COLD AIR ADVCS SWD...SOME OF THE PCPN MAY MIX WITH OR CHG TO SNOW...BUT ANY ACCUMS WILL BE MINIMAL. IN THE WAKE OF THE WAVE...SOME ERADICATION OF CLD CVR CAN BE XPCD OVNGT. TEMPS WILL FALL INTO THE UPR 20S-LWR 30S BY MRNG AS WIND BCMS LGT AND DEWPT TEMP DECRS. A SLGT INCR IN CLD CVR WILL BE PSBL ON MON AS BNDRY LYR HEATS AND MIXES AND STRATOCU DVLPS. SFC HIPRES WILL DOMINATE WX ON MON IN MOST AREAS...BUT A SHRTWV TROF IS XPCD TO RIDE ALONG THE STALLED FRONTAL BNDRY IN SRN WV. THIS TROF MAY AID IN NWD DVLPMT OF LGT PCPN FOR THE RDG ZONES MON AFTN-MON EVE...WHERE INHERITED POPS WERE RETAINED.
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&& .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
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FAST AND LOW-AMPLITUDE FLOW WILL PERSIST IN THE GRTLKS RGN MID-WK. SHRTWV TROF ENTERING NRN PLNS ON TUE MRNG WILL BE ACCOMPANIED BY ARCTIC AMS...WHICH WILL MODIFY ONLY SLGTLY AS IT PROGRESSES ESEWD INTO THE GRTLKS RGN. THE WAVE WILL PASS THRU THE FCST AREA ON TUE...WITH COLD AIR XPCD TO FOLLOW QUICKLY. MAXIMA WED WILL BE IN THE UPR TEENS-MID 20S F OWING TO AGGRESSIVE COLD AIR. ARCTIC AIR ALSO HAS A TALENT FOR SQUEEZING OUT ANY AVAILABLE MSTR. GIVEN RECENT WARMTH...THIS AMS LKLY WILL INDUCE LAKE-ENHANCED SNOW DESPITE MODEL INDICATIONS TO THE CONTRARY. CONSEQUENTLY...POPS WERE INCLD IN NRN ZONES FOR SNOW SHWRS FROM TUE AFTN-WED AFTN WHEN THE FLOW WILL HAVE AT LEAST A REASONABLY-ORIENTED DIRECTION. POPS IN RDG ZONES ALSO WERE CONTD TUE AFTN-TUE EVE AS FLOW WILL HAVE UPSLP COMPONENT. BY WED MRNG... SFC RDG AXIS WILL BUILD EWD AND SHOULD LWR INVERSION SUFFICIENTLY TO PRECLUDE SGFNT PCPN IN THE RDGS. TEMPS WED NGT WILL BE QUITE COLD...WITH MINIMA FALLING TO THE LOW- MID TEENS. SINGLE-DIGIT WIND CHILLS ARE XPCD WED NGT.
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&& .LONG TERM /THURSDAY THROUGH SUNDAY/...
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FLOW WILL BCM VRB AND EVENTUALLY LGT SWLY ON THU AS SFC HIPRES CNTRD IN THE RGN MOVES EWD IN RESPONSE TO EJECTING SHRTWV TROF IN SRN PLNS. THE EXIT OF HIPRES WILL HERALD A SLOW WARMING TREND INTO THE WKEND. POTENT SHRTWV TROF XPCD TO IMPACT FCST AREA FRI NGT THRU SAT NGT. BOTH GFS AND ECMWF SHOW REMARKABLE CONSISTENCY...WITH THE SFC FEATURE PASSING TO THE NW OF THE FCST AREA AND LEADING TO STRONG WARM AIR ADVCTN THAT SHOULD KEEP PCPN MAINLY LIQUID. ONLY CAVEAT WILL BE SUB-FREEZING TEMPS AT ONSET...WHICH COULD SPELL A FRZG RAIN/SLEET SCENARIO. POPS WERE INCRD FRI AFTN-SAT NGT GIVEN CERTAINTY IN OCCURRENCE OF PCPN...BUT UNCERTAINTY RMNS IN PCPN TYPE. PCPN LKLY WILL BGN AS WINTRY MIX BFR CHGG TO ALL RAIN BY MID-DAY SAT...SO THIS PSBLTY HAS BEEN INCLD IN HWO. OTHER CONCERN WILL BE AMT OF PCPN. STRONG WARM ADVCTN AMID DP SWLY FLOW AND POTENCY OF WAVE WILL PROMOTE SGFNT RAINFALL...WHICH COULD LEAD TO LOCALIZED HYDROLOGIC ISSUES. FCST WILL NEED TO BE MONITORED FOR THIS POTL.
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&& .AVIATION /20Z SUNDAY THROUGH FRIDAY/... DRIZZLE WITH AREAS OF IFR CIGS WL GIVE WAY TO MVFR STRATOCU TONIGHT. GIVEN THE HIGH LOW LEVEL MOISTURE THERE COULD BE SOME RESTRICTIONS IN FOG IN A FEW LOCATIONS LATE TONIGHT AND EARLY MONDAY. OUTLOOK.../MONDAY THROUGH THURSDAY/... PERIODIC RESTRICTIONS CAN BE EXPECTED FOR THE FIRST HALF OF THE WEEK WITH COLD ADVCTN AND CROSSING DISTURBANCES. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$ KRAMAR

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