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000
FXUS61 KPBZ 180757
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
357 AM EDT SAT MAY 18 2013

.SYNOPSIS...
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SEASONABLY WARM WEATHER WILL CONTINUE OVER THE WEEKEND WITH COOLER
THAN NORMAL TEMPERATURES IN THE MOUNTAINS. HOWEVER...A CHANCE OF
SHOWERS AND POSSIBLY AN AFTERNOON THUNDERSTORM WILL ALSO BE IN
THE FORECAST.
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&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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WEAK FRONTAL SYSTEM CONTINUES TO OUR SOUTH. NOT A LOT OF PUSH NE
WITH H5 RIDGE STILL TO OUR WEST AND ACTUALLY SHARPENS A LITTLE WITH
MIDWEST LOW STARTING TO LOW PUSH EAST BY LATE SUNDAY. HEIGHTS
ACTUALLY ON THE RISE. SURFACE FRONT WILL TRY MOVING NE AND FAIRLY
GOOD MOISTURE GRADIENT ACROSS CWA AT THIS TIME WITH TD 39 FKL AND
58 ZZV. EXPECT MOISTURE TO CONTINUE TO SLOWLY INCREASE BUT THINK
POPS LIMITED TO CHANCE. ALSO SREF ADVERTISING SLOWNESS OF
MOISTURE WITH CALIBRATED PROBABILITY THUNDER FIELD VERY SLOW TO PROGRESS
NE AND TIGHT GRADIENT ALONG PA/OH BORDER OF THUNDER PROBABILITY.
AS A RESULT...WILL KEEP THUNDER OUT MOST OF PA FOR TODAY AND BRING
IT IN ALONG SOUTHERN PORTIONS AND EAST-CENTRAL OH. NAM BIAS COR
TEMPS HAVE BEEN RATHER GOOD RECENTLY...HOWEVER THIS GUIDANCE ADVERTISING
MID 80S MANY PLACES TODAY. THOUGHT THIS A LITTLE HIGH GIVEN
INCREASE IN CLOUDS AND OPTED TO GO WITH BLEND NAM BIAS COR AND
MOS. APPALACHIAN PLATEAU TO REMAIN RATHER COOL WITH CONTINUED EAST-
SOUTHEAST FLOW.
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&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
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WEAK FRONT CONTINUES TO MEANDER JUST SOUTH OF REGION.
MEANWHILE...APPALACHIAN PLATEAU CONTINUES COOL WITH SHOWERS UNDER
E-SE FLOW. REMNANT MOISTURE WILL CONTINUE TO GIVE CHANCE POPS WITH
A DIURNAL MINIMUM OVERNIGHT AND INCREASE WITH AFTERNOON HEATING
AND SUBSEQUENT INSTABILITY INCREASE. FRONTAL SYSTEM FINALLY TO
PUSH NORTHWARD LATER MONDAY WITH INCREASE IN SOUTHERLY FLOW AND
RISE IN TEMPERATURES.
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&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
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UPPER LEVEL RIDGING CONTINUES IN PART DUE TO MIDWEST CUTOFF LOW
PUSHING EAST. MEANWHILE...SURFACE FRONT STILL DRAPED CLOSE TO OR
JUST NORTH OF REGION. MID-WEST UPPER LEVEL LOW WILL CONTINUE TO
PUSH EAST BUT LOSE INTENSITY AND IN FACT OPENS UP AS IT
APPROACHES OUR AREA. AS A RESULT...SYSTEM SLOWS AND TAKES IT TIME
TO EXIT REGION BY END OF PERIOD. AS A CONSEQUENCE...POPS CONTINUE
UNTIL LATE IN FORECAST PERIOD.
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&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
VFR FORECAST TODAY. WILL START WITH A SCT-BKN CIRRUS DECK. AS THE
EARLY MORNING PROGRESSES AND AREA OF MID CLOUDS WILL MOVE ACROSS
NORTHERN PORTS AND AREA OF MID CLOUDS WILL MOVE INTO SOUTHERN
PORTS. THIS SOUTHERN DECK WILL DECAY BY LATE MORNING...ALLOWING
FOR SUNSHINE AND THE DEVELOPMENT OF CU. IT IS POSSIBLE THAT A
SHOWER OR STORM COULD DEVELOP OVER PORTS SOUTH OF PIT IN THE
AFTERNOON...BUT WITH LOW CONFIDENCE AT CONVECTION HITTING ANY
PARTICULAR PORT... WILL INSTEAD INDICATE CB.

.OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/...
THERE WILL BE AN INCREASING CHC FOR RESTRICTIONS IN DIURNALLY SPPRTED
SCT SHOWERS AND THUNDERSTORMS DURING THE FIRST HALF OF THE WEEK.

&&

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

&&

$$