Skip Navigation Linkswww.nws.noaa.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service Forecast Office   NWS logo - Click to go to the NWS homepage
Pittsburgh, PA banner image
 
 

Area Forecast Discussion
Latest Versions  [Current][-1][-2][-3][-4][-5][-6][-7][-8][-9]



000
FXUS61 KPBZ 312054
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
454 PM EDT SUN AUG 31 2014

.SYNOPSIS...
ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM CHANCES WILL
CONTINUE INTO MONDAY. A COLD FRONT WILL BRING MORE WIDESPREAD
SHOWERS AND STORMS TUESDAY.

&&

.NEAR TERM /THROUGH MONDAY/...
SCATTERED SHWRS WL CONT INTO THE EVE AS A SHRTWV EXITS. ANOTHER WK
MID LVL WAVE WL GRAZE AREAS S OF THE PA BORDER LTR TNGT WITH SOME
ADDNL SHWRS...THOUGH MUCH OF THE PCPN SHOULD RMN TO THE S. PWATS
RMN ELEVATED BUT WITH LACK OF INSTBY AND UPR SPPRT NOT EXPG A
SGFNT HEAVY RAINFALL THREAT. 

ISOLD TO SCT SHWRS AND TSTMS ARE EXPD MON...BUT WITH NO SHRTWV
SPPRT NOT EXPG ORGANIZED ACTIVITY. WARMING IN THE MID LVLS THRU
THE DAY SHOULD ALSO HELP TO KEEP ANY ACTIVITY LMTD. TEMPS WL RMN A
FEW DEG ABV SEASONAL LVLS. 

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
THINK WE START MAINLY DRY MONDAY EVENING IN FLAT FLOW WITH
RELATIVELY LITTLE MOISTURE. MAIN CONCERN FOR THIS PERIOD IS
FRONTAL BOUNDARY PROGGED TO CROSS ON TUESDAY. MOST MODELS ARE ON
BOARD WITH FRONTAL TIMING...SAVE THE GFS WHICH SEEMS A BIT TOO
FAST. HAVE CHANCE POPS NW OF PIT/HLG THROUGH 12Z TUESDAY...AND
THEN ROLL LIKELY POPS THROUGH WITH FROPA. MOISTURE DOES POOL AHEAD
OF BOUNDARY BUT NOT TO EXTENT OF TODAY...TOPPING OUT AR0UND 1.8
INCH PWAT. SOME MODEST SUPPORT ALOFT WITH RRQ OF H250 JET NOT TOO
FAR TO THE NW...ALTHOUGH MIDLEVEL WAVE ARRIVES POST-FROPA. A
GENERAL HALF TO THREE-QUARTER INCH RAINFALL LOOKS REASONABLE.

AS FOR SEVERE THREAT...THERE CERTAINLY WILL BE ENOUGH FLOW...WITH
40-50 KNOTS AT H500 AND 35-40 KNOTS OF 0-6KM SHEAR. INSTABILITY
WILL BE IN QUESTION THOUGH AS CLOUD COVER FIGURES TO BE ABUNDANT
FOR MOST OF THE DAY. LIKE THE CURRENT SPC IDEA OF A 5 PERCENT
RISK AREA. STORM MOTION PLUS A BIT LESS EFFICIENT RAIN PRODUCTION
WILL ALSO HOPEFULLY KEEP THE FLOOD THREAT AT BAY. GOING FOR A
FAIRLY SMALL DIURNAL RANGE IN TEMPERATURE DUE TO THE
CLOUDS/PRECIP...BUT VALUES WILL REMAIN A TOUCH ABOVE NORMAL.

SOME SHRA MAY LINGER BEHIND THE FRONT FOR A FEW HOURS WITH H500
WAVE PASSING THROUGH...OTHERWISE WE SHOULD DRY OUT BY 06Z
WEDNESDAY. DECREASING CLOUDS THEREAFTER...WITH A FAIR BIT OF SUN
ON WEDNESDAY. DESPITE ZONAL FLOW...H500 HEIGHTS WILL BE A BIT
HIGH...SO EXPECT HIGH TEMPS TO REMAIN A FEW DEGREES ABOVE NORMAL.
A SEASONABLY COOL NIGHT CAN BE EXPECTED WEDNESDAY NIGHT...AND
WOULD NOT BE SURPRISED TO SEE PATCHY DENSE FOG.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL REMAIN ALONG THE EAST COAST THROUGH THURSDAY 
NIGHT...ALLOWING CONDITIONS TO REMAIN DRY. WHILE THE 00Z GFS KEEPS 
AN APPROACHING COLD FRONT TO THE NORTHWEST ON FRIDAY...ECMWF AND 
SEVERAL ENSEMBLES SHOW THE FRONT APPROACHING MORE QUICKLY...AND HAVE 
SPED UP TIMING IN FORECAST. WHILE PRECIPITATION COVERAGE WILL WANE 
OVERNIGHT...COVERAGE SHOULD INCREASE AGAIN ON SATURDAY WITH FAIRLY 
DECENT MODEL TIMING THIS FAR OUT. IN ADVANCE OF THE COLD 
FRONT...TEMPERATURES WILL BE ABOUT FIVE DEGREES ABOVE NORMAL.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
MAINLY MVFR CONDS EXPD INTO THE EVE ALONG WITH SCT SHWRS AS A
DISTURBANCE EXITS. A GRDL DCR TO IFR IS EXPD OVRNGT WITH PLENTY OF
LLVL MOISTURE IN PLACE. EXP A GRDL RTN TO VFR BY ERLY MON AFTN.
ISOLD TO SCT AFTN CNVCTN IS PSBL ALSO...BUT COVG EXPD TO BE TOO
LOW FOR A MENTION IN THE TAFS ATTM.

OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
SHWR/TSTM RSTRNS ARE LIKELY WITH A TUE CDFNT. 

&&

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

&&

$$






National Weather Service
Disclaimer Privacy Policy