Area Forecast Discussion
Issued by NWS

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KPBZ 020030 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 830 PM EDT MON SEP 1 2014 .SYNOPSIS... SCATTERED SHOWERS AND STORMS WILL DIMINISH IN COVERAGE GOING INTO THE EVENING...WITH HUMID AND SOMEWHAT UNSTABLE CONDITIONS CONTINUING THROUGH EARLY TUESDAY. A COLD FRONT WILL ADVANCE ACROSS THE AREA TUESDAY...BRINGING WIDESPREAD SHOWERS AND STORMS. && .NEAR TERM /THROUGH TUESDAY/...
-- Changed Discussion --
WITH 830PM UPDATE...CUT POPS THROUGH THE REST OF THE OVERNIGHT HOURS WITH COVERAGE HAVING SIGNIFICANTLY DECREASED IN THE LAST HOUR OR TWO. UPSTREAM PRECIPITATION COVERAGE IS ALSO ON THE WANE...AND HIGH RESOLUTION MODELS DO NOT SHOW MUCH MORE DEVELOPING OVERNIGHT. LINE OF CONVECTION WELL NORTH OF THE FORECAST AREA WILL NOT HAVE AN IMPACT. ONLY MINOR CHANGES TO OTHER PORTIONS OF THE FORECAST. PREVIOUS DISCUSSION FOLLOWS. THE REAL FOCUS BY TONIGHT LOOKS TO BE TURNING TO THE DAYTIME ON TUESDAY...WHEN THE MID-LEVEL SYSTEM APPROACHES FROM THE GREAT LAKES ALONG WITH THE ASSOCIATED COLD FRONT. MODEL SOLUTIONS SEEM TO BE KEYING IN ON A LATE MORNING/EARLY AFTERNOON ARRIVAL INTO NORTHWEST PORTIONS OF THE AREA...WITH A MID-AFTERNOON CROSSING OF THE PITTSBURGH AREA...AND A LATE AFTERNOON/EARLY EVENING EXIT OF THE CWA FOR THE FRONTAL BOUNDARY. INSTABILITY ALONG THE FRONT WHILE LIKELY CONTINUING TO BE RATHER DEEP...SHOULD ALSO BE RATHER UNIMPRESSIVE OWING IN LARGE PART TO A LACK OF INSOLATION AHEAD OF THE FRONT THROUGH THE EARLY PORTIONS OF THE DAY. THIS SHOULD LIMIT ADDITIONAL DESTABILIZATION. ADDITIONALLY...OWING TO THE FACT THAT THE MID-LEVEL WAVE LARGELY SHEARS OFF TO OUR NORTH...0-6 KM BULK SHEAR VALUES REALLY ONLY RUN UP TOWARD 35 KTS OF WEAKLY VEERED FLOW AS THE BOUNDARY IMPINGES UPON THE AREA. AGAIN WITH THIS VARIABLE...THOSE VALUES DO NOT EXACTLY MAKE THIS FORECASTER PARTICULARLY JUMPY. FURTHERMORE...WITH SHEAR VALUES THAT HIGH AND A FAIRLY QUICK MOVING WAVE PASSAGE...WHILE THE CELLS THAT DO MOVE THROUGH ARE LIKELY TO BE HEAVY RAIN PRODUCERS...PROLONGED HEAVY RAINFALL IN ANY PARTICULAR LOCATION AS WELL AS TRAINING OF ECHOES SEEMS UNLIKELY. THIS SHOULD MINIMIZE THE RISK OF FLASH FLOODING AS WELL. IT IS WORTH NOTING THAT SPC HAS PLACED THE AREA IN A SLIGHT RISK FOR TOMORROW...HOWEVER OWING TO LESS THAN STELLAR INSTABILITY VALUES...MODERATE SHEAR...A LACK OF INSOLATION...FORCING THAT FOCUSES HEIGHT FALLS LARGELY TO THE NORTH OF THE AREA ALONG WITH THE HIGHEST SHEAR VALUES...IT SEEMS LIKE THIS SLIGHT RISK IS A LESS CONFIDENT SLIGHT RISK THAN NORMAL. FRIES
-- End Changed Discussion --
&& .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... COLD FRONT EXITS EAST TUES NIGHT QUICKLY AS THE UPPER LEVEL FLOW GOES ZONAL. HIGH PRESSURE QUICKLY BUILDS AT THE SFC WEDS WITH SKIES GENERALLY CLEARING THROUGH THURS. TEMPS WILL REMAIN AT OR ABOVE AVERAGE BOTH DAYS AS THE SFC HIGH SHIFTS EAST ALLOWING FOR WARM...ALBEIT WEAK...SOUTHERLY FLOW. HIGH PRESSURE WILL KEEP THREAT OF RAIN OUT OF THE FORECAST DURING THE LATTER PART OF THE WORK WEEK. TAX && .LONG TERM /FRIDAY THROUGH MONDAY/... HIGH PRESSURE WILL REMAIN ALONG THE EAST COAST THROUGH FRIDAY... ALLOWING CONDITIONS TO REMAIN DRY. COLD FRONT WILL BRING SHOWERS AND STORMS FOR THE BEGINNING OF THE WEEKEND...WITH COOLER DRIER AIR FOR THE END OF THE LONG TERM. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... ISOLATED SHOWERS WILL DISSIPATE THROUGH 02Z WITH END OF DAYTIME HEATING. EXPECT MVFR FOG AT MOST LOCATIONS IN LOW LEVEL MOISTURE WITH KFKL AND KDUJ HAVING IFR STRATUS BEFORE DAYBREAK. FOR TUESDAY COLD FRONT WILL MOVE INTO THE REGION WITH SHOWERS AND THUNDERSTORMS BECOMING MORE NUMEROUS WEST TO EAST LATE MORNING TO EARLY AFTERNOON. FOR NOW WILL GO WITH MVFR THUNDER AT TIMES IN TAFS AS THIS WILL NEED TO BE REFINED IN LATER ISSUANCE. A WEAK WESTERLY WIND SHIFT WILL WORK INTO THE REGION LATE DAY. OUTLOOK.../TUESDAY NIGHT THROUGH SATURDAY/... A CHANCE OF SHOWERS/STORMS WILL LINGER INTO TUESDAY NIGHT...WITH RESTRICTIONS POSSIBLE WEDNESDAY MORNING IN FOG/STRATUS. RESTRICTIONS ARE THEN POSSIBLE FRIDAY/SATURDAY WITH ANOTHER COLD FRONT. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.