Area Forecast Discussion
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000 FXUS61 KPBZ 010744 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 344 AM EDT TUE SEP 1 2015 .SYNOPSIS... WARM AND HUMID CONDITIONS WILL CONTINUE THROUGH THE WEEK WITH ISOLATED DAYTIME SHOWERS AND THUNDERSTORMS POSSIBLE. && .NEAR TERM /THROUGH TONIGHT/...
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THE ONGOING FORECAST WILL START TO FEEL A BIT LIKE A BROKEN RECORD AS VERY WARM AND HUMID CONDITIONS WILL CONTINUE OVER THE AREA INTO THE FIRST WEEK OF SEPTEMBER. DEWPOINTS THIS MORNING ARE GENERALLY RUNNING IN THE MIDDLE TO UPPER 60S...WHICH IS ALLOWING FOR BOUNDARY LAYER SATURATION NEAR AREA RIVER VALLEYS AND OTHER BODIES OF WATER. THIS IS ALLOWING FOR SOME FOG...WHICH SHOULD DISSIPATE FAIRLY QUICKLY AFTER SUNRISE. OTHERWISE...AN EXCEEDINGLY WEAK UPPER TROUGH CONTINUES TO RESIDE ESSENTIALLY ALONG THE OHIO VALLEY AS AN AMPLIFYING AND EXTREMELY POSITIVELY-TILTED UPPER RIDGE BUILDS OVER THE CENTRAL GREAT LAKES. AS THIS UPPER RIDGE CONTINUES TO AMPLIFY OVER THE NEXT 24 HOURS...THE UPPER TROUGH WILL GRADUALLY WEAKEN AND LOSE DEFINITION AS THE BASE OF IT TRANSITS THE SOUTHERN FRINGE OF THE CWA. THOUGH AMPLE INSTABILITY RESIDES OVER THE REGION...MODEL SOUNDINGS DO NOTE SOME LIMITED ABILITY FOR VERTICAL MASS TRANSIT PAST ABOUT 12 KFT DUE TO WARM AIR ALOFT. THAT SAID...A SOUPY BOUNDARY LAYER AND WEAK WESTERLY FLOW INTO THE RIDGES MAY ALLOW FOR JUST ENOUGH INITIATION FOR UPDRAFTS TO BUMP PAST 12 KFT. SOME LOW END POPS WERE CARRIED ALONG THE RIDGES FOR THIS DURING THE AFTERNOON...OTHERWISE THE BULK OF THE CWA SHOULD REMAIN DRY TODAY AND TONIGHT. THE ONLY EXCEPTION MAY BE BACK TOWARD THE BASE OF THE WEAKENING UPPER WAVE IN OHIO...WHERE VERY LOW END SLIGHT CHANCE POPS WERE CARRIED DURING THE AFTERNOON. TEMPERATURES LOOK TO GENERALLY BE PERSISTENCE PLUS A DEGREE OR TWO DUE TO A BIT OF A WARMER START TO THE DAY TODAY. AMPLE SUNSHINE WILL AGAIN ALLOW FOR MID 80S TO LOWER 90S TO BE WIDESPREAD BY AFTERNOON WITH HIGH HUMIDITY AND VERY LITTLE VENTILATION. FRIES
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&& .SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
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CLOSED AN CUT-OFF UPPER-LEVEL LOW CURRENTLY OVER ILLINOIS WILL FINALLY DISLODGE AND DRIFT SLOWLY EASTWARD EVENTUALLY GETTING ABSORBED BACK INTO THE LARGE SCALE FLOW PATTERN. AS THE LOW OPENS AND CROSSES THE FORECAST AREA WEDNESDAY...ROUNDING THE TOP OF THE UPPER-RIDGE...SHOWER CHANCES WILL INCREASE WEDNESDAY AFTERNOON EVENING. ALTHOUGH THE BROAD UPPER-RIDGE REMAINS...SHOWER AND THUNDERSTORM CHANCES WILL OCCUR DAILY FOLLOWING A DIURNAL PATTERN THROUGH THE LATTER PART OF THE WEEK. THE POSITION OF THE SURFACE LOW FRIDAY WILL BE CONDUCIVE TO ADVECTING ADDITIONAL MOISTURE EAST TO WEST FROM THE MID-ATLANTIC. RAISED POPS FRIDAY...ESPECIALLY IN THE HIGH TERRAIN OF PENNSYLVANIA/WEST VIRGINIA/MARYLAND. WITH THE PATTERN HOLDING FAIRLY STEADY...ONLY MINOR TWEAKS WERE MADE TO THE ABOVE AVERAGE TEMPERATURES THAT WILL DOMINATE THE WEEK. TAX
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&& .LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
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STOUT UPPER-RIDGE WILL BEGIN TO FLOP EASTWARD AS A NW CONUS LOW DEEPENS AND MOVES EASTWARD. THE PINNACLE OF THE RIDGE WILL BREAK OFF AND CENTER DIRECTLY OVER OUR REGION TOWARDS THE LATTER PART OF THE WEEKEND. THIS WILL QUELL THE DIURNAL RAIN CHANCES...AND KEEP TEMPERATURES ABOVE AVERAGE. A COLD FRONT WILL APPROACH THE GREAT LAKES TOWARDS THE MIDDLE OF NEXT WEEK...BUT AT THIS TIME IT APPEARS POISED TO DO LITTLE MORE THAN FLATTEN THE UPPER-LEVEL FLOW. TAX
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&& .AVIATION /08Z TUESDAY THROUGH SATURDAY/...
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SOME MVFR AND LOCAL IFR AROUND KFKL AND KDUJ FOG IS EVIDENT EARLY THIS MORNING. ALL OF IT SHOULD DISSIPATE BY AROUND 14Z...WITH VFR CONDITIONS AT ALL SITES THEREAFTER. LIGHT WIND WILL BE PRESENT OVER ALL SITES. OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY... GENERAL VFR IS EXPECTED THROUGH THE PERIOD WITH SOME RESTRICTIONS POSSIBLE DURING MORNING FOG AND ISOLATED DIURNAL THUNDERSTORMS POSSIBLE LATER IN THE WEEK.
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&& .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$

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