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 181850
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
250 PM EDT WED MAR 18 2015

.SYNOPSIS...
HIGH PRESSURE WILL KEEP CONDITIONS DRY THROUGH THURSDAY. AREA OF
LOW PRESSURE CROSSING THE OHIO VALLEY WILL BRING RAIN AND SNOW 
THURSDAY NIGHT AND FRIDAY.

&&

.NEAR TERM /THROUGH THURSDAY/...
SUBSIDENCE WILL KEEP CONDITIONS DRY WITH PLENTIFUL SUNSHINE TODAY.
AS HIGH PRESSURE SHIFTS EAST ALONG WITH UPPER LEVEL TROUGH...MID
LEVEL MOISTURE WILL RETURN FROM THE WEST AND SOUTH AS ZONAL FLOW
BECOMES MORE SOUTHWESTERLY THURSDAY. ABUNDANT LOW LEVEL DRY AIR
WILL HOLD OFF PRECIPITATION LATE THURSDAY AS THE WAVE OF LOW
PRESSURE DEVELOPS ACROSS THE OHIO VALLEY.

NORTHWEST FLOW WILL PROVIDE COOLER THAN NORMAL TEMPERATURES FOR
THE PERIOD.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
A PLUME OF MOISTURE ACROSS THE SOUTHEAST STATES WILL SUPPLY A
DEVELOPING LOW ACROSS THE OHIO VALLEY THURSDAY NIGHT AS A
SHORTWAVE TROUGH APPROACHES FROM THE NORTHERN PLAINS. MODEL
DIAGNOSTICS CONFIRM THAT 850MB WARM AIR WILL ADVECT NORTHWARD AS
850MB LOW IS DISPLACED TO THE NORTH OF THE SURFACE LOW. THICKNESS
LEVELS WILL BE TOO WARM TO PRODUCE ACCUMULATING SNOW. IN
ADDITION...SURFACE TEMPERATURES WILL HOVER MOSTLY ABOVE FREEZING
SOUTH OF THE I-76 CORRIDOR AS THIS WILL HELP LIMIT ANY SNOW
ACCUMULATION. NORTH OF PITTSBURGH...SREF AND GEFS PLUMES INDICATES
MOSTLY SNOW FOR THE BRIEF 12 HOUR PERIOD BUT QPF REMAINS LIGHTER
THAN SOUTHERN AREAS. TEMPERATURES WILL QUICKLY RISE FRIDAY MORNING
TO CHANGE RAIN OVER TO SNOW.

BRIEF ZONAL FLOW ADVANCES FRIDAY NIGHT THROUGH SATURDAY BEFORE A
WEAK COLD FRONT SUPPORTED BY AN UPPER SHORTWAVE PASSES THROUGH THE
AREA SATURDAY NIGHT WITH VERY LIMITED MOISTURE. BEST CHANCES FOR
VERY LIGHT PRECIPITATION...IF ANY...WOULD BE NORTH OF PIT AND
ACROSS THE RIDGES WITH WEAK UPSLOPE...AND THEREFORE INTRODUCED
SLIGHT CHANCE POPS. OTHERWISE...HIGH PRESSURE QUICKLY REINFORCES
ITS WAY FROM THE NORTHWEST TO DRY CONDITIONS OUT.

TEMPERATURES WILL MOSTLY BE COOLER THAN AVERAGE WITH THE EXCEPTION
OF SATURDAY AS RELATIVELY WARM AIR ADVECTS OVER THE REGION WITH
LOW LEVEL SOUTHWEST FLOW.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
THE EXTENDED PERIOD BEGINS WITH NORTHWEST FLOW REASSERTING ITSELF 
ALOFT. THIS WILL KEEP AT LEAST THE THREAT OF POPS IN FOR SATURDAY AS 
MOISTURE ASSOCIATED WITH A WEAK SURFACE LOW AND REINFORCING COLD 
FRONT DROP THROUGH THE FORECAST AREA. WITH SOME DISAGREEMENT ON THE 
SOUTHERN EDGE OF THAT MOISTURE...OPTED TO SIDE CLOSER TO THE 
OPTIMISTIC GFS WHICH KEEPS THE AREA MOSTLY DRY SATURDAY. 

THE SLIGHTLY ABOVE NORMAL TEMPERATURES FORECAST FOR SATURDAYS HIGHS 
WILL BE SHORT-LIVED AS THE COLD FRONT WILL KNOCK TEMPERATURES DOWN 
SATURDAY NIGHT. TEMPERATURES WILL THEN STAY BELOW AVERAGE THROUGH 
THE EARLY PART OF NEXT WEEK AS HIGH PRESSURE BUILDS IN FROM THE 
NORTHWEST. A RETURN TO NEAR NORMAL LOOKS LIKELY MIDDLE OF NEXT WEEK. 
TAX

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH
THURSDAY...MAINTAINING VFR CONDITIONS THROUGH THE TAF PERIOD.
GUSTY NORTHWEST WINDS WILL DIMINISH EARLY THIS EVENING AFTER
NIGHTTIME INVERSIONS SET UP AND PREVENT STRONGER WINDS ALOFT FROM
MIXING DOWN TO THE SURFACE. WINDS WILL BE RELATIVELY LIGHT TOMORROW 
WITH THE SURFACE HIGH CENTERED OVER THE AREA.

.OUTLOOK.../WEDNESDAY NIGHT THROUGH SUNDAY/...
RESTRICTIONS WILL BE POSSIBLE BETWEEN EARLY FRIDAY MORNING AND
LATE FRIDAY EVENING AS AN AREA OF LOW PRESSURE TRACKS ACROSS THE REGION.
&&

&&

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

&&

$$






National Weather Service
Disclaimer Privacy Policy