Area Forecast Discussion
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000
FXUS61 KPBZ 291242
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
842 AM EDT SUN MAR 29 2015

.SYNOPSIS...
SUNNY AND DRY WITH SLIGHTLY WARMER TEMPERATURES TODAY AHEAD OF A
WEAK SYSTEM THAT WILL BRING RAIN AND SNOW OVERNIGHT INTO MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
CRISP AND CLEAR MORNING AREAWIDE AS SURFACE HIGH PRESSURE SLOWLY
PASSES JUST SOUTH OF THE AREA. AS THE CENTER OF THE HIGH MOVES
INTO THE MID-ATLANTIC TODAY...THE CLOCKWISE FLOW AROUND IT WILL
SUPPORT SOUTHERLY FLOW BRINGING WARMER TEMPERATURES TO THE
FORECAST AREA. WITH TEMPERATURES BEGINNING WELL BELOW AVERAGE AND
EVEN NEAR RECORD IN SOME CASES...THE WARMER SOUTHERLY BREEZES WILL
HAVE A LONG WAY TO GO TO GET BACK INTO THE REALM OF AVERAGE.
SO DESPITE THE WARM SOUTHERLY FLOW AND ABUNDANT
SUNSHINE...TEMPERATURES WILL REMAIN ABOUT 10 DEGREES BELOW
AVERAGE...WHICH FOR THE AREA ARE IN THE 50S.

TONIGHT...A RELATIVELY DRY AND WEAK SYSTEM WILL MOVE THROUGH THE
WESTERN GREAT LAKES AND OUR WEST. AS THE MAIN TROF AXIS
ENTERS...A WEAK WARM FRONT WILL LIFT JUST INTO THE SOUTHERN
EXTENT OF THE FORECAST AREA...KEEPING TEMPERATURES ACROSS THE
SOUTHERN HALF OF OUR COUNTIES ELEVATED. TIMING ACROSS MODEL
GUIDANCE HAS BEEN FAIRLY CONSISTENT...BUT THE LATEST RUNS PUSH
TIMING BACK AN HOUR OR TWO AS IT FIGHTS THE DRY AIR FIRMLY
ENTRENCHED.


PREDOMINANT PRECIPITATION TYPE SOUTH OF PITTSBURGH IS EXPECTED TO
BE RAIN...BUT AREAS NEAR PITTSBURGH AND NORTH WILL COOL ENOUGH TO
TRANSITION THE PRECIPITATION FROM RAIN TO A RAIN/SNOW MIX. MODEL
SOUNDINGS NORTH OF I-80 INDICATE THIS AREA HAS THE BEST CHANCE TO
SEE ALL SNOW. REGARDLESS OF PRECIPITATION TYPE...WITH ONLY MODEST
FORCING AND OVERUNNING OF MID- AND UPPER-LEVEL
MOISTURE...PRECIPITATION RATES SHOULD BE LOW. LITTLE...IF
ANY...SNOW ACCUMULATION IS EXPECTED THROUGH MONDAY MORNING.
TAX

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
AFTER A BRIEF BREAK...ANOTHER SHORTWAVE WILL QUICKLY BRUSH BY TO
THE NORTH ON TUESDAY BUT SIMILAR TO THE PREVIOUS SYSTEM...SNOW
WILL BE CONFINED MAINLY TO NORTHERN ZONES WITH AS THERE WILL ONLY
BE A BRIEF PERIOD OF DEEPER MOISTURE TO WORK WITH. WEDNESDAY WILL
BE DRY WITH SEASONAL TEMPERATURES AS HIGH PRESSURE BUILDS IN FROM
THE WEST.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS HIGH PRESSURE MOVES OFFSHORE WEDNESDAY NIGHT...A FRONT WILL
APPROACH FROM THE WEST. WHILE 00Z GFS SLOWED THE ARRIVAL OF THE
FRONT SOME FROM PREVIOUS MODEL RUNS...00Z ECMWF IS EVEN SLOWER THAN
THAT. HOWEVER...WITH DECENT ENSEMBLE SUPPORT...WILL STICK WITH GFS
TIMING AND BRING IN LIKELY POPS FOR THURSDAY NIGHT. HOWEVER...LOW
PRESSURE FORMING ALONG THE COLD FRONT WILL KEEP PRECIPITATION IN THE
FORECAST FRIDAY UNTIL IT MOVES INTO NEW ENGLAND SATURDAY. THURSDAY
WILL EASILY BE THE WARMEST DAY OF THE WEEK...WITH MOST LOCATIONS
REACHING THE 60S. TEMPS WILL DROP ABOUT 10 DEGREES EACH
DAY...LEADING BACK TO YET ANOTHER PERIOD OF BELOW NORMAL VALUES.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL CONTINUE OVERNIGHT THROUGH THE DAYTIME HOURS.
SOUTH-SOUTHWEST WINDS WILL BE ON THE INCREASE THIS
AFTERNOON...WITH GUSTS UP TO 20 KTS POSSIBLE. A COLD FRONT
ENTERING THE REGION THIS EVENING IS EXPECTED TO BRING
PRECIPITATION TO ALL SITES...ALTHOUGH IT WILL NOT REACH MGW UNTIL
AFTER THE 06Z TAF PERIOD. SOUTH AND WEST OF PITTSBURGH SHOULD
REMAIN ALL RAIN...WITH SOME SNOW MIXING IN ELSEWHERE. CEILINGS
WITH PRECIPITATION SHOULD INITIALLY BEGIN AS VFR...BUT ARE
EXPECTED TO QUICKLY DROP TO MVFR. SOME MARGINAL LOW LEVEL WIND
SHEAR MAY ALSO DEVELOP OVERNIGHT IF WINDS DECOUPLE...ESPECIALLY
WEST OF PITTSBURGH...BUT DID NOT HAVE ENOUGH CONFIDENCE TO INCLUDE
IN TAFS AT THIS TIME.

.OUTLOOK.../MONDAY THROUGH THURSDAY/...
RESTRICTION POTENTIAL CONTINUES INTO MONDAY MORNING...AND
RESTRICTIONS ARE POSSIBLE ONCE AGAIN WITH CROSSING LOW PRESSURE
TUESDAY AND THURSDAY.

&&

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

&&

$$






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