Area Forecast Discussion
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000
FXUS61 KPBZ 080221
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1021 PM EDT MON JUL 7 2014

.SYNOPSIS...
SHOWERS AND THUNDERSTORMS ARE EXPECTED AGAIN ON TUESDAY. HIGH
PRESSURE WILL THEN RESULT IN DRIER WEATHER FOR THE REST OF THE
WEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
EARLIER CONVECTION IS NOW RELEGATED TO THE FAR SOUTHEASTERN
PORTIONS OF THE FORECAST AREA AND HAS DECREASED IN INTENSITY SUCH
THAT NO LIGHTNING HAS BEEN NOTED FOR QUITE A WHILE NOW. UPSTREAM
CONVECTION OVER CENTRAL OHIO AND NORTHEASTERN OHIO SHOULD ADVECT
INTO THE AREA OVERNIGHT...AND WITH FAIRLY STRONG SHEAR REMAINING
IN PLACE...IT IS LIKELY TO HOLD TOGETHER AT LEAST IN SOME FASHION.
HOWEVER...MOST OF THE RESIDENT AIR MASS HAS ALREADY BEEN FAIRLY
WELL WORKED OVER DUE TO THIS EVENING`S CONVECTION...AND
INSTABILITY WAS NOT PARTICULARLY IMPRESSIVE EVEN IN THE HEAT OF
THE DAY. AS SUCH...INTENSITY OF THE SHOWERS AND THUNDERSTORMS
SHOULD CONTINUE TO WANE OVERNIGHT. FRIES

PREVIOUS DISCUSSION TUESDAY FOLLOWS...A STRONG COLD FRONT
CURRENTLY OVER THE NORTHERN PLAINS WILL MAKE EASTWARD
PROGRESS...APPROACHING THE REGION BY LATE TUESDAY. WHILE
INSTABILITY VALUES WILL BE SLIGHTLY HIGHER THAN TODAY...WIND SHEAR
WILL BE SUBSTANTIALLY STRONGER. THIS WILL RESULT IN A GREATER
THREAT FOR SEVERE WEATHER ON TUESDAY COMPARED TO MONDAY. IN
ADDITION...OVERALL MOISTURE WILL INCREASE WITH PRECIPITABLE WATER
VALUES APPROACHING TWO INCHES. IF ANY STORMS DO MANAGE TO TRAIN
AND TRACK OVER THE SAME LOCATION ALONG THE FRONT...THE CHANCE FOR
FLOODING COULD NOT BE RULED OUT.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
SEVERE THREAT WILL CONTINUE INTO TUESDAY EVENING AS THE COLD FRONT
COMPLETES PASSAGE ACROSS THE AREA. FRONT COULD LINGER ACROSS THE
RIDGES ON WEDNESDAY...KEEPING A CHANCE OF SHOWERS IN THE FORECAST.
WITH COLD POOL REMAINING ACROSS THE REGION...CANNOT RULE OUT AN
ISOLATED SHOWER ELSEWHERE. AS HIGH PRESSURE MOVES INTO THE GREAT
LAKES REGION WEDNESDAY NIGHT...THIS SHOULD FINALLY CLEAR THINGS
OUT AND ALLOW FOR A DRY FORECAST INTO THURSDAY. AN ISOLATED
SPRINKLE REMAINS POSSIBLE ACROSS THE RIDGES ON THURSDAY...BUT DID
NOT HAVE CONFIDENCE TO PUT THIS IN THE FORECAST THREE DAYS OUT.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
FRIDAY THE SFC HIGH GETS FAR ENOUGH NORTHEAST THAT SOUTHERLY
FLOW ACROSS THE MID-ATLANTIC COULD BEGIN TO POOL MOISTURE ALONG THE
ERN SLOPES OF THE RIDGES. THE NEXT SYNOPTIC SYSTEM IS POISED TO
MOVE THROUGH THE SRN GREAT LAKES INTO THE AREA OVER NEXT SAT. GFS
AND ECMWF CONTINUE TO HAVE LARGE DIFFERENCES IN HOW TO HANDLE THE
WAVE PASSAGE. ECMWF PHASES TWO WAVES ULTIMATELY AMPLIFYING BROAD
UPPER TROF...WHILE THE 00Z GFS HAS DOUBLED DOWN ON PASSING A
LEADING WAVE QUICKLY THROUGH IN ZONAL FLOW. FOR THIS UPDATE HAVE
SIDED WITH THE ECMWF...BUT WITH THIS PORTION OF THE FORECAST 6 AND
7 DAYS OUT...DECIDED TO TAKE A LESS THAN DETERMINISTIC APPROACH TO
POPS. TAX

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
THUNDERSTORM COVERAGE OVER MOST SITES HAS WANED...HOWEVER ACTIVITY
ENTERING THE AREA NEAR KZZV WILL LIKELY ALLOW FOR ANOTHER ROUND OF
TS GENERALLY BETWEEN KZZV AND KHLG FOR THE NEXT FEW HOURS.
RAINFALL TODAY AT SOME SITES WILL ALLOW FOR MVFR STRATUS AND VIS
OVERNIGHT...WITH SOME LOCATION IFR LIKELY IN KFKL AND KDUJ WHERE
MUCH MORE RAINFALL OCCURRED. ANOTHER SYSTEM MOVES THROUGH THE AREA
ON TUESDAY...WITH ANOTHER ROUND OF AFTERNOON
SHOWERS/THUNDERSTORMS/GUSTY WINDS LIKELY WITH SOMEWHAT UNCERTAIN
TIMING AT THE MOMENT. FRIES

.OUTLOOK.../TUESDAY THROUGH SATURDAY/...
RSTRNS ARE PSBL WED WITH AN ADVNG DISTURBANCE.

&&

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

&&

$$





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