-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPBZ 291953
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
253 PM EST THU JAN 29 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TONIGHT...FOLLOWED BY BUILDING
HIGH PRESSURE FRIDAY AND SATURDAY. LOW PRESSURE MAY BRING MORE
WINTRY WEATHER SUNDAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
A CDFNT WL MOVE ACRS THE RGN THIS EVE WITH ADDNL SNW SHWRS. SOME
RAIN COULD MIX IN ERLY THIS EVE S OF I 80. WITH LK ERIE MOSTLY
FROZEN...ONLY A LIMITED CONNECTION OFF LK HURON IS EXPD MAINLY ACRS
NW PA. FAVORABLE CONDS FOR UPSLOPE SNW SET UP OVRNGT WITH INCRG MSTR
IN THE SNW GROWTH RGN AND NW FLOW. CONTD WINTER WEA ADVY FOR THE
RIDGES AND NW PA THRU FRI WITH SEVERAL INCHES OF SNW EXPD. TEMPS
WERE FCST USING A LAMP/SREF BLEND.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
EXTENDED THE WINTER WEA ADVY THRU THE DAY FRI FOR THE
RIDGES...THOUGH WITH A FROZEN LAKE ERIE WL ALLOW FOR THE NW PA
PORTION EXPIRE AT FRI MRNG. UPSLOPE SNW SHWRS SHOULD CONT THRU THE
DAY IN THE RIDGES BEFORE THINNING MSTR IN THE SNW GROWTH RGN AND
LWRG TEMP INVERSIONS END THE PCPN. A CROSSING UPR TROF SHOULD
ALLOW FOR SOME SCT SNW SHWRS OUTSIDE OF THIS AREA AS WELL.

BLDG HIGH PRES SHOULD BRING DRY WEA FRI NGT INTO SAT.

BELOW SEASONAL AVG TEMPS WERE FCST USING THE LATEST SREF NMBRS.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
MODELS CONT TO JOUST IN HANDLING OF LOW PRES PROJECTED TWD THE MID
ATLANTIC REGION FM SATURDAY NGT INTO MONDAY. PERSISTENCE RMNS
PRUDENT WITH LATEST GFS IN GENL LINE WITH CURRENT THINKING OUTSIDE
OF TIMING ISSUES. MEANWHILE...ECMWF IS FORECASTING A SOUTHWARD
TRACK TO SFC SLOW CENTER AND PCPN SHIELD. BOTH MDLS CONT TO DEPICT
AN OPEN MID LVL WAVE.

BOTTOM LINE IS THAT AN EXTENDED PERIOD OF LGT...TO MODERATE...BUT
ACCUMULATING SNOW IS LIKELY...WITH CONFIDENCE BUILDING FOR AREAS
ALNG THE INTERSTATE 70 CORRIDOR.

COLDER WEATHER WL FOLLOW AS A SERIES OF SHRTWVS AGAIN DIG AN ERN
CONUS UPR TROUGH...DETAILS FOR WHICH WL BE REFINED WITH TIME.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
CONDITION DETERIORATION IS UNDERWAY AND DEGRADATIONS CAN BE
EXPECTED INTO FRIDAY AS MIXED PCPN SPREADS OVR UPR OH TERMINALS
AND CHANGES TO SNOW WITH CDFNT PASSAGE THIS EVE. IFR CAN BE
EXPECTED IN SNOW SHWRS THIS EVE...AND IN WIDESPREAD STRATUS WHICH
WL ACCOMPANY THE COLD SURGE OVR THE REGION.

.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
IMPROVEMENTS CAN BE EXPECTED AS HIGH PRES BLDS LTR ON
SATURDAY...HOWEVER...SNOW AND RESTRICTIONS ARE LIKELY WITH SUNDAY
LOW PRES.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WINTER WEATHER ADVISORY UNTIL 7 PM EST FRIDAY FOR MDZ001.
OH...NONE.
PA...WINTER WEATHER ADVISORY UNTIL 10 AM EST FRIDAY FOR PAZ007>009-
     015-016-023.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST FRIDAY FOR PAZ074-076.
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST FRIDAY FOR WVZ023-041.

&&

$$

07/15