-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPBZ 251745
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1245 PM EST SUN JAN 25 2015

.SYNOPSIS...
LOW PRESSURE WILL BRING WIDESPREAD SNOW LATER TODAY THROUGH
MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
LATEST WV IMAGERY SHOWS MID LEVEL LOW CENTER JUST OVER NE
MISSOURI WITH A JET MAX NEARING THE BASE OF THE LONGWAVE...SO
ANTICIPATE THE LOW CENTER TO CONTINUE SOUTH JUST A LITTLE LONGER
BEFORE BEGINNING TO SHIFT EAST. THIS GOES ALONG WELL WITH RECENT
MODEL PROGS AND DO NOT ANTICIPATE ANY MAJOR CHANGES TO THE ONGOING
FORECAST THIS AFTERNOON. ONLY UPDATE WAS TO TWEAK HOURLY
TEMPERATURES TO BETTER REFLECT OBSERVATIONAL TRENDS AND ADD
MENTION OF MODERATE SNOW THIS EVENING FOR AREAS UNDER BEST
FORCING. PREV DISCUSSION BELOW..

ATTENTION THEN TURNS TO A DEEPENING SHRTWV MOVG OUT OF THE MID
WEST AND WRN GT LKS RGN. THIS SHRTWV WL ADVANCE ACRS OUR RGN LTR
TDAY SPREADING SNW ACRS THE RGN. CRITICAL THICKNESSES AND MDL
SOUNDING PROFILES INDICATE THE PCPN MAY MIX WITH OR CHG TO RAIN NR
AND S OF THE SRN PA BORDER THIS AFTN INTO THIS EVE..CUTTING DOWN
ON SNW TOTALS.

MDLS CONT TO OPEN THE MID LVL WAVE AS IT ADVNS ACRS ERN OH INTO PA
AS THE TRANSITION TO A COASTAL LOW TAKES PLACE. MSTR AND OMEGA
FIELDS STILL INDICATE A BAND OF MODERATE SNW WL LIKELY DVLP ACRS
AREAS FM ZZV TO PIT TO LBE THIS EVE INTO THE OVRNGT HRS BEFORE THE
MID LVL WAVE OPENS LT TNGT. WITH MDL TRENDS SHOWING A SLGT NWD
PUSH TO THE PCPN...DECIDED TO EXPAND THE WINTER WEA ADVY FURTHER
NWD INTO NW PA.

FCST WAS BASED ON A SREF/MDL BLEND TO SMOOTH OUT DIFFERENCES...
COMBINED WITH SURROUNDING WFO AND WPC COORDINATION.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
SNW IS EXPD TO CONT THRU MON AND MON EVE AS THE SHRTWV CONTS ITS
TRACK ACRS THE AREA. ADVY LVL SNW TOTALS OF 4-6 INCHES ARE EXPD FM
NR ZZV TO PIT TO LBE...WITH SOMEWHAT LESSER AMTS N OF I 80 AND
AREAS WELL S OF PIT.

BROAD UPR TROFG IS PROGGED TO BEGIN TO SHIFT E OF THE RGN TUE WITH
DCRG SNW SHWR CHCS. BLDG HIGH PRES WED SHOULD BRING DRY WEA.

BELOW SEASONAL AVG TEMPS WERE FCST BASED ON THE LATEST SREF NMBRS.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
FAST MOVING CLIPPER SYSTEM WILL BRING ANOTHER ROUND OF SNOW
THURSDAY INTO THURSDAY NIGHT WITH A WINTRY MIX POSSIBLE ALONG AND
SOUTH OF I-70. BUMPED UP POPS TO LIKELY FOR THIS SYSTEM. UPPER
LEVEL TROUGH WILL REMAIN IN PLACE INTO NEXT WEEKEND WITH WELL
BELOW NORMAL TEMPERATURES. SOME IMPORTANT TIMING DIFFERENCES FOR
NEXT WEEKEND WITH NEXT CLIPPER AND DELIVERY OF EVEN COLDER ARCTIC
AIR INTO THE UPPER OHO VALLEY. WPC PROGS LOOKS TO BE A GOOD
COMPROMISE WITH A CHANCE OF SNOW SHOWERS LATER SATURDAY THROUGH
SUNDAY.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THERE ARE A MIX OF MVFR/IFR CIGS IN ADVANCE OF THE LOW PRESSURE
SYSTEM THAT WILL MOVE INTO THE REGION THIS AFTERNOON/EVENING. AS
WIDESPREAD SNOW ARRIVES...ALL SITES WILL BECOME IFR AND EVENTUALLY
LIFR. FKL/DUJ ARE THE ONLY SITES THAT MAY NOT DROP TO LIFR IF
HEAVIER SNOW REMAINS TO THE SOUTH. ALSO EXPECT ZZV/MGW TO HAVE A
MIX OF RAIN/SNOW BEFORE CHANGING TO ALL SNOW. INTERMITTENT VLIFR
IN HEAVIER SNOW BANDS IS ALSO POSSIBLE...BUT DO NOT HAVE
CONFIDENCE FOR TIMING/LOCATION TO INCLUDE IN 18Z TAFS. SNOW WILL
CONTINUE...BUT IS EXPECTED TO EASE UP IN INTENSITY...BY MONDAY
MORNING.

.OUTLOOK.../MONDAY THROUGH FRIDAY/...
RESTRICTIONS IN SNOW WILL CONTINUE MONDAY AFTERNOON INTO TUESDAY.
NEXT WIDESPREAD RESTRICTIONS THURSDAY AFTERNOON INTO FRIDAY WITH A
CLIPPER SYSTEM.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR MDZ001.
OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR OHZ039>041-
     048>050-057>059-068-069.
PA...WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR PAZ007>009-
     013>016-020>023-029-031-073>076.
WV...WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR WVZ001>004-
     012-021>023-041.

&&

$$