Area Forecast Discussion
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FXUS61 KPBZ 030730
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
330 AM EDT FRI JUL 3 2015

.SYNOPSIS...
A CROSSING UPPER DISTURBANCE WILL INCREASE RAIN CHANCES FOR THE
START OF THE HOLIDAY WEEKEND. WARMER WEATHER CAN BE EXPECTED FOR
THE START OF THE NEW WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
A SHORTWAVE MOVING TOWARD THE AXIS OF THE BROAD UPR TROUGH OVER
THE EASTERN CONUS IS SHUNTING MID AND UPR LEVEL CLOUDINESS OVER
THE UPPER OHIO VALLEY REGION THIS MORNING. CLOUD COVER HAS THUS
BEEN ADJUSTED WITH MORNING TEMPS PROJECTED ALONG HIGH RES MODEL
TRENDS.

THE SLOW ADVANCE OF THAT DISTURBANCE IS EXPECTED TO INCREASE
SHOWER CHANCES THROUGH TODAY AS FLOW ALOFT BACKS AND MOISTURE
DEEPENS. POPS WERE AGAIN RECONSTRUCTED USING A BLEND OF THE
CONSISTENT GFS AND NAM DEPICTIONS...WITH LIKELY NUMBERS CONFINED
COLLABORATIVELY TO THE SOUTHEASTERN QUADRANT OF THE COUNTY WARNING
AREA...ROUGHLY FOR THE PITTSBURGH TO MORGANTOWN AND SURROUNDING
AREAS WHERE MOISTURE CONVERGENCE LOOKS MORE LIKELY GIVEN THE
PROGGED TRACK OF THE MID LEVEL TROUGH.

INSTABILITY DOES NOT LOOK IMPRESSIVE ON ANY OF THE INCOMING
MODELS...HENCE A SLIGHT THUNDER MENTION WAS INCLUDED ONLY FOR THE
LIKELY POP AREAS AS MENTION ABOVE.

NO MAJOR CHANGES WERE NEEDED FOR TEMPS...WITH EXPECTED HIGHS STILL
FORECAST A FEW DEGREES UNDER THE SEASONAL AVERAGES.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
SCATTERED/CHANCE POP NUMBERS WERE MAINTAINED THROUGH SATURDAY AS
MODELS PERSIST IN LINGERING THE UPPER TROUGH OVER THE
REGION...ALBEIT WITH DRY ADVECTION IN THE MID AND UPPER LEVELS.
DESPITE THE TROUGHING...MID LEVEL TEMPS IN THIS SCENARIO ARE
WARM...HENCE THE LIMITED POPS AND ONLY A SLIGHT CHANCE OF THUNDER
DUE TO INHIBITED INSTABILITY.

BY SUNDAY...THE SURFACE REFLECTION PROGNOSIS IS SUFFICIENTLY SOUTH
THAT RAIN CHANCES HAVE BEEN OMITTED WITH BUILDING HIGH PRESSURE.
WARMER TEMPS WILL THEN BE THE FOCUS AS HEIGHTS RISE DRAMATICALLY
FOR THE START OF THE NEW WEEK. FOR NOW...HAVE PERSISTED WITH
AVERAGE READINGS FOR SUNDAY...AND A COUPLE DEGREES ABOVE FOR
MONDAY.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
THE UPPER FLOW IS PROGGED TO FLATTEN THROUGH MUCH OF THE PERIOD.
INDIVIDUAL SHORTWAVES IN THE FLOW ARE EXPECTED TO BRING PERIODIC
CHANCES FOR SHOWERS AND THUNDERSTORMS. USED AN ENSEMBLE BASED WPC
GUIDANCE TO SMOOTH OUT DIFFERENCES IN INDIVIDUAL MODELS...WITH
DOWNWARD ADJUSTMENTS TO WPC POPS. SEAONALLY WARM TEMPERATURES ARE
EXPECTED.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH EARLY FRIDAY NORTH OF
I 70...THOUGH INCREASED LOW LEVEL MOISTRUE TO THE SOUTH COULD LEAD
TO MVFR FOG OVERNIGHT INTO FRIDAY MORNING. A SHORTWAVE IS PROGGED
TO BRING INCREASING SHOWER CHANCES THIS AFTERNOON AND
EVENING...WITH EVENTUAL CONDITION DETERIORATION SOUTH OF I 80 TO
AT LEAST MVFR SPREADING IN FROM THE SOUTHWEST.

.OUTLOOK.../SATURDAY THROUGH TUESDAY/...
RESTRICTION ARE POSSIBLE THROUGH EARLY SATURDAY WITH AN EXITING
SHORTWAVE.

&&

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

&&

$$
15/07



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