Area Forecast Discussion
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000
FXUS61 KPBZ 290832
AFDPBZ

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

.SYNOPSIS...
CONTINUED DRY CONDITIONS AND SLIGHTLY WARMER TEMPERATURES EXPECTED
TODAY AHEAD OF A COLD FRONT RESULTING IN RAIN AND SNOW OVERNIGHT
INTO MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NEAR RECORD LOW TEMPERATURES THIS MORNING WILL RECOVER TODAY AS
SURFACE HIGH OVER THE AREA SHIFTS EAST AND WINDS TURN TO THE
SOUTHWEST AHEAD OF AN APPROACHING FRONTAL SYSTEM. MINIMAL CLOUD
COVERAGE WILL BEGIN TO INCREASE THIS AFTERNOON AS TEMPERATURES
REACH INTO THE 40S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
LIFT AND MOISTURE ADVECTION WILL INCREASE RAPIDLY LATE SUNDAY EVENING
AHEAD OF THE APPROACHING FRONTAL SYSTEM...OVERCOMING THE VERY DRY
BOUNDARY LAYER QUICKLY AS PRECIPITATION DEVELOPS BEFORE MIDNIGHT.
SIGNIFICANT QPF AMOUNTS ARE STILL NOT EXPECTED AS THIS SYSTEM IS
QUICK MOVING AND WILL BE EAST OF THE FORECAST AREA BY MID TO LATE
MONDAY MORNING.

MODELS HAVE SHOWN DECENT CONTINUITY OVER THE PAST COUPLE DAYS WITH
THIS SYSTEM AND STILL EXPECT THE PREDOMINANT P-TYPE TO BE RAIN.
HOWEVER...THERE WILL BE A FAIR AMOUNT OF EVAPORATIVE COOLING IN
THE BOUNDARY LAYER AS PRECIPITATION DEVELOPS AND SNOW LOOKS MORE
LIKELY TO AT LEAST BE OBSERVED AS FAR SOUTH AS PITTSBURGH BEFORE
CHANGING OVER TO RAIN...BUT NO SIGNIFICANT ACCUMULATION IS
EXPECTED.
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 /08Z 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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