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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPBZ 040025
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
725 PM EST TUE MAR 3 2015

.SYNOPSIS...
-- Changed Discussion --
LOW PRESSURE CROSSING THE GREAT LAKES WILL CONTINUE TO SPREAD RAIN
OVER THE UPPER OHIO VALLEY REGION TONIGHT. RAIN WILL TURN TO SNOW
WITH A WEDNESDAY COLD FRONT.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH WEDNESDAY/...
-- Changed Discussion --
THE WINTER WEATHER ADVISORY FOR COUNTIES NORTH OF PITTSBURGH HAS
BEEN ALLOWED TO EXPIRE AS MOST TEMPERATURE REPORTS ARE IN THE MID
30S...WITH FURTHER INCREASE TOWARD THE UPPER 30S EXPECTED THROUGH
THE EVENING.

OTHERWISE...THE FLOOD WATCH HAS BEEN MAINTAINED AS SNOW MELT WILL
AGGRAVATE ANY ONGOING POOR DRAINAGE ISSUES RESULTING FROM A
GENERAL 0.2 TO 0.4 INCHES OF RAIN. HOWEVER...AREAS ALONG AND SOUTH
OF A LINE FROM ZANESVILLE TO LATROBE MAY WANT TO PAY SPECIAL
ATTENTION THROUGH THE NIGHT AS A CROSSING JET STREAK IS MODEL
PROGGED TO ENHANCE MID LEVEL FRONTOGENESIS FOR BETTER RAINFALL
FOCUS. THINK AN ADDITIONAL 0.20 OVER NORTHERN AREAS TO ABOUT AN
INCH OVER SOUTHERN COUNTIES IS A REASONABLE BASIN AVERAGE PROGNOSIS
AT THIS TIME AND IS BASED ON MORE CONSERVATIVE ECMWF GUIDANCE.

A TRANSITION TO SNOW WILL OCCUR WITH THE ENCROACHMENT OF THE COLD
FRONT ON WEDNESDAY. ANY SNOW THAT FALLS THROUGH THE DAY SHOULD BE
LIMITED BY INEFFICIENT WITH SNOW RATIOS AND LITTLE ACCUMULATION IS
EXPECTED INTO THE EVENING.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY NIGHT/...
-- Changed Discussion --
THE WINTER STORM WATCH FOR WEDNESDAY NIGHT AND THURSDAY HAS BEEN
CONTINUED FOR AREAS ROUGHLY ALONG AND SOUTH OF A ZANESVILLE TO
INDIANA LINE...BUT THE NORTHWARD EXTENT OF DEEPER MOISTURE AND
ASCENT BEHIND THE WAVE SLOWED FRONTAL ZONE IS CERTAINLY QUESTIONABLE
AND AN ADDITIONAL SET OF MODEL RUNS WILL BE NECESSARY FOR BETTER
RESOLUTION.

AT ANY RATE...SNOW SHOWERS WILL DIMINISH THROUGH THURSDAY AFTERNOON
WITH ARCTIC HIGH PRESSURE CLEARING OUT SKIES. WITH LIGHT WINDS
TEMPERATURES EXPECTED TO CRASH NEAR OR BELOW ZERO WITH FRESH SNOW
COVER.

SUNSHINE BUT CONTINUED COLD FRIDAY WITH TEMPERATURES 15 TO 20
DEGREES BELOW SEASONAL AVERAGES.
-- End Changed Discussion --

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
OVERALL...THE LONG TERM PERIOD LOOKS QUIET WITH THE PASSAGE OF A
COUPLE OF WEAK FRONTS SATURDAY NIGHT AND THEN AGAIN LATE MONDAY.
AT THIS TIME...MODELS ARE SHOWING LITTLE MOISTURE ACCOMPANYING
EITHER OF THESE SYSTEMS. A SLOW MODERATION IN TEMPS IS EXPECTED
THROUGH THE ENTIRE PERIOD.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
IFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH MUCH OF WEDNESDAY
AS LOW PRESSURE CROSSES THE GREAT LAKES REGION. ANY FREEZING RAIN
AT DUJ SHOULD BE CHANGING OVER TO RAIN BY 01Z AS THE LOWS
ASSOCIATED WARM FRONT MOVES NORTH. A GRADUAL CHANGEOVER TO SNOW IS
EXPECTED FROM NORTH TO SOUTH DURING THE DAY WEDNESDAY...WITH
FKL/DUJ CHANGING LATE TONIGHT...PIT IN THE MORNING AND MGW TOWARD
EVE. AN IMROVEMENT TO LOW END MVFR IS EXPECTED FROM PIT NORTH BY
AFTERNOON AS THE ASSOCIATED COLD FRONT PUSHES SOUTH.

LOW LEVEL WIND SHEAR SHOULD PERSIST THIS EVENING BEFORE A LOW
LEVEL JET EXITS.

.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
WIDESPREAD RESTRICTIONS ARE EXPECTED INTO THURSDAY AS A WAVE OF
LOW PRESSURE MOVES ALONG A COLD FRONT...WITH SNOW MAINLY FROM PIT
SOUTH. RESTRICTIONS ARE POSSIBLE WITH A SUNDAY COLD FRONT.
-- End Changed Discussion --

&&

.HYDROLOGY...
-- Changed Discussion --
THE COMBINATION OF SNOW MELT AND DEVELOPING RAIN IS EXPECTED TO CAUSE
SIGNIFICANT RISES ON THE CHEAT... MONONGAHELA AND YOUGHIOGHENY
RIVER BASINS. THESE RISES WILL AID IN MOVING ICE INTO AREAS WHERE
ICE JAMS ARE KNOWN TO DEVELOP. THE RISES WILL MOST LIKELY PERSIST THROUGH
THURSDAY. CONFIDENCE IN RAIN AMOUNTS REMAINS LOW...BUT THE BETTER
CHANCE FOR MORE SIGNIFICANT ACCUMULATION IS EXPECTED TO BE ALONG
AND SOUTH OF A ZANESVILLE TO LATROBE LINE.
-- End Changed Discussion --

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
MD...FLOOD WATCH THROUGH WEDNESDAY EVENING FOR MDZ001.
     WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
     AFTERNOON FOR MDZ001.
OH...FLOOD WATCH THROUGH WEDNESDAY EVENING FOR OHZ049-050-057>059-
     068-069.
     WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
     AFTERNOON FOR OHZ057>059-068-069.
PA...FLOOD WATCH THROUGH WEDNESDAY EVENING FOR PAZ014-020>023-029-
     031-073>076.
     WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
     AFTERNOON FOR PAZ021-023-029-031-073>076.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     PAZ007>009-013>016-022-023.
WV...FLOOD WATCH THROUGH WEDNESDAY EVENING FOR WVZ001>004-012-
     021>023-041.
     WINTER STORM WATCH FROM WEDNESDAY AFTERNOON THROUGH THURSDAY
     AFTERNOON FOR WVZ002>004-012-021>023-041.
-- End Changed Discussion --

&&

$$

15/07