Area Forecast Discussion
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000
FXUS61 KPBZ 252148
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
548 PM EDT SAT OCT 25 2014

.SYNOPSIS...
AFTER A SLIGHT COOL DOWN FOR SUNDAY...TEMPERATURES WILL WARM WELL
ABOVE NORMAL MONDAY AND TUESDAY. A COLD FRONT TUESDAY NIGHT WILL
BRING RAIN AND A RETURN TO COLDER TEMPERATURES.

&&

.NEAR TERM /THROUGH SUNDAY/...
A WEAK COLD FRONTAL BOUNDARY IS CURRENTLY WORKING THROUGH THE
WESTERN PORTIONS OF THE CWA EARLY THIS EVENING...WITH JUST A FEW
CLOUDS MANAGING TO BE GENERATED AHEAD OF IT. A DEARTH OF LAYER
MOISTURE IS EVIDENT WITH IT...AND GIVEN FAIRLY STRONG BOUNDARY
LAYER DEWPOINT DEPRESSIONS AHEAD OF IT...EVEN THE LIFT ALONG THE
FRONT WILL BE INSUFFICIENT TO GENERATE ANY RAIN SHOWERS AS IT
PASSES. THAT SAID...STEEP LAPSE RATES AND STRONG MIXING
AHEAD...ALONG..AND BEHIND THE FRONT ARE EVIDENT...AND GIVEN STRONG
MOMENTUM IN THE LOWEST 5 KFT OF THE OVERNIGHT MODEL SOUNDINGS...IT
WOULD SEEM SOME WIND GUSTS WILL BE LIKELY TO CONTINUE THROUGH THE
FIRST PART OF TONIGHT.

THE BIGGEST RAMIFICATION OF THE FRONTAL PASSAGE BEYOND THE WIND
WILL LIKELY BE THE FALL IN DEWPOINTS. UPSTREAM DEWPOINT VALUES ARE
RUNNING INTO THE 20S AND 30S...DOWN FROM THE LOWER 50S OVER THE
REGION NOW. WHILE NEITHER SIDE OF THE FRONT IS MOIST...IT IS QUITE
CERTAIN THAT VERY DRY AIR IS ON ITS WAY IN. AS A RESULT...SKIES
WERE CLEARED OUT RAPIDLY WITH THE FRONTAL PASSAGE...AND WILL
LIKELY REMAIN CLEAR THROUGH THE DAY ON SUNDAY. FRIES

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE ALONG THE EAST COAST WILL BRING FLOW WITH A SOUTHERLY
COMPONENT...ALLOWING FOR TEMPERATURE TO RISE ABOVE NORMAL. NEARLY
ALL LOCATIONS ARE EXPECTED TO REACH THE 70S ON TUESDAY AHEAD OF AN
ADVANCING COLD FRONT. HAVE SPED UP ARRIVAL TIME OF PRECIP...AND HAVE
NOW BROUGHT IN A CHANCE OF RAIN EVERYWHERE BY LATE TUESDAY
AFTERNOON. 12Z GFS AND NAM BOTH SHOW SMALL AMOUNTS OF INSTABILITY IN
ZANESVILLE SOUNDING...AND HAVE ALSO ADDED A SLIGHT CHANCE OF THUNDER
FOR PORTIONS OF OHIO.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
COLD FRONT WILL RACE ACROSS REGION TUESDAY NIGHT AND HAVE GONE
WITH LIKELY POPS FOR SHOWERS WITH FRO PA AND UPPER LEVEL TROUGH.
FAIRLY QUIET WEATHER FOR WEDNESDAY AND THURSDAY WITH WEAK SURFACE
RIDGE STRETCHED ACROSS THE UPPER OHIO VALLEY. BY FRIDAY DEEPENING
UPPER LEVEL SYSTEM AND DEVELOPING SURFACE LOW PRESSURE WILL BRING
SHOWERS BACK TO THE REGION FOLLOWED BY MUCH COOLER CONDITIONS FOR
THE START OF NEXT WEEKEND.

&&

.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
GUSTY SOUTHWESTERLY WINDS WILL CONTINUE UNTIL MID EVENING BEFORE
DECOUPLING AFTER FRONTAL PASSAGE TONIGHT. THERE IS SOME
UNCERTAINTY IN HOW SOON WINDS WILL LESSEN AT THE SURFACE BUT FOR
NOW REFLECT THIS OCCURRING SHORTLY AFTER MIDNIGHT AT MOST
LOCATIONS. IF WINDS DECOUPLE EARLIER...LOW LEVEL IND SHEAR WILL
BE A CONCERN AS LATEST RAP SOUNDINGS SHOW 40KTS AT 1KFT AGL BY MID
EVENING. REMOVED MVFR CIGS FROM 18Z TAFS AS MUCH DRIER AIR WILL BE
MOVING IN BEHIND THE COLD FRONT. MODELS ARE ALL IN VERY GOOD
AGREEMENT SHOWING LIMITED LOW LEVEL MOISTURE...AND MODEL SOUNDINGS
SHOW A LARGE ENOUGH MARGIN BETWEEN TEMPERATURE AND DEWPOINT
PROFILES DESPITE THE COLD AIR ADVECTION BEHIND THE FRONT.


OUTLOOK.../SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH EARLY NEXT WEEK.

&&

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

&&

$$






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