Area Forecast Discussion
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000 FXUS61 KPBZ 260815 AFDPBZ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PITTSBURGH PA 415 AM EDT SAT JUL 26 2014 .SYNOPSIS... THE RISK FOR SHOWERS AND STORMS WILL RETURN THIS WEEKEND. THE MAIN FOCUS WILL BE TONIGHT AND SUNDAY. SHOWERS WILL CONTINUE ON MONDAY WITH COOLER AIR ARRIVING TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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SHORTWAVE TROUGH WILL RUSH EASTWARD THIS MORNING...ENDING THE SHOWERS AND ALLOWING FOR A REDUCTION IN CLOUD COVER. UPPER LEVEL HEIGHTS WILL RESPOND WITH SOME RIDGING ALOFT. WAA WILL ENSUE WITH THE RISING HEIGHTS AND A SOUTHWESTERLY FLOW IN THE LOWER LEVELS. CURRENT MODEL RUNS ARE NOT SHOWING MUCH ACTIVITY...IF ANY TODAY. THE AFOREMENTIONED HEIGHT RISES WILL STALL AND LEAVE THE AREA UNDER NORTHWEST FLOW ALOFT. UPPER LEVEL WAVES THIS AFTERNOON WILL REMAIN WEST OF THE REGION...AS WILL THE REAL UNSTABLE AIR. A FRONTAL BOUNDARY...CONNECTED TO A SURFACE LOW OVER THE MIDWEST... WILL STRETCH ACROSS LAKE ERIE THIS AFTERNOON. ITS POSSIBLE THAT A SHOWER OR STORM COULD DEVELOP LATE TODAY...BUT CONFIDENCE IS LOW. MODEL SOUNDINGS ARE SHOWING A PRETTY WELL CAPPED ATMOSPHERE WITH UNIMPRESSIVE SHEAR VALUES. CLOUDS WILL INCREASE AGAIN THIS AFTERNOON AS ANOTHER UPPER LEVEL WAVE RUSHES THROUGH.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... ACTIVITY SHOULD BEGIN TO INCREASE TONIGHT AS THE SURFACE LOW CONTINUES EASTWARD INTO IL AND ATMOSPHERE DESTABILIZES. MODELS ARE SHOWING A NOCTURNAL MCS DEVELOPING NEAR THE SURFACE LOW TONIGHT AND HEADING SOUTHEASTWARD WITH THE MAIN UPPER LEVEL WAVE. SPOKES OF ENERGY WILL BREAK AWAY FROM THE MAIN SHORTWAVE AND DRIFT EASTWARD OVER WESTERN AND SOUTHERN PORTIONS OF THE AREA. EXPECT ACTIVITY TO DEVELOP WITH THESE WAVES...BUT AGAIN...THEY WILL BE MOVING INTO MORE STABLE AIR. SHEAR VALUES WILL INCREASE TONIGHT SO IF ACTIVITY GETS ROLLING IT SHOULD BE SUSTAINABLE. I WOULD THINK THAT THE STRONGEST ACTIVITY WOULD BE WEST WITH THE MAIN MCS. SUNDAY SURE LOOKS LIKE THE DAY THAT WILL BE MOST WORRISOME. ATMOSPHERE WILL CONTINUE ITS DESTABILIZATION AS THE SURFACE LOW MOVES INTO WESTERN OHIO. A VERY BUOYANT ATMOSPHERE WITH STRONG MOISTURE CONVERGENCE AND SHEAR WILL PROVIDE A THREAT FOR SEVERE WEATHER. THE SOUTHERN HALF OF THE AREA SEEMS TO BE PARTICULARLY IN THE BULLS-EYE. IF MODELS ARE CORRECT...ANOTHER MCS SHOULD QUICKLY DEVELOP OVER WESTERN OHIO SUNDAY MORNING AND MOVE EASTWARD WITH THE SURFACE LOW. WIDESPREAD WIND DAMAGE IS POSSIBLE IF THE MCS DEVELOPS. ADDITIONALLY...LATEST FORECAST HODOGRAPHS ARE SHOWING HELICITY VALUES REACHING NEAR 500 IN THE SOUTH. THIS WILL INCREASE THE THREAT FOR TORNADO DEVELOPMENT. HEAVY DOWNPOURS ARE ALSO POSSIBLE AS PWATS REACH CLOSE TO 2 INCHES. AGAIN...SUNDAY AFTERNOON WILL NEED TO BE CLOSELY WATCHED...WITH THE HIGHEST THREAT ACROSS THE SOUTH. COMPLEX WILL EXIT LATE SUNDAY AFT/EARLY EVENING AND THE ATMOSPHERE WILL BEGIN TO CALM DOWN. ANOTHER UPPER LEVEL DISTURBANCE WILL CROSS LATE SUNDAY NIGHT/MONDAY MORNING...KEEPING IN THE RISK FOR SHOWERS AND POSSIBLY A STORM. A SECONDARY COLD FRONT...SPINNING AROUND BEHIND THE UPPER LEVEL DISTURBANCE CROSSES MONDAY AFTERNOON. SO SHOWERS WILL CONTINUE WITH THE RISK OF A STORM AS THE BOUNDARY SWINGS THROUGH. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... SHOWERS WILL END MONDAY NIGHT AS ENTIRE SYSTEM QUICKLY MOVES EASTWARD. HIGH PRESSURE WILL PROVIDE A COOL AND COMFORTABLE MIDWEEK. ANOTHER WEAK COLD FRONT MAY BRING SHOWERS THURSDAY. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... VFR IN THE TAFS...WITH CAVEATS. SHORTWAVE MOVING ACROSS THROUGH 10Z OR SO IS PROVIDING MAINLY MID CLOUDS AND A FEW SPRINKLES/-SHRA. THE SHRA WILL MOVE OUT BUT THE MID CLOUDS WILL REMAIN THROUGH MUCH OF THE DAYLIGHT HOURS. SOME SCT CU MAY FORM UNDERNEATH. CANNOT RULE OUT A FEW SHRA/TSRA IN DAYTIME HEATING BUT THOUGHT CHANCES A BIT LOW TO INCLUDE AT THIS POINT. THINGS GET INTERESTING TOWARDS THE TAIL END OF THE TAF PERIOD...PARTICULARLY ACROSS ERN OH AND SRN WV...WHERE THE OUTSKIRTS OF AN MCS COULD ROLL THROUGH AFTER 02Z. INCLUDED VCTS TO HINT AT THIS...BUT OCCURRENCE/TIMING ARE STILL UNCERTAIN. BRIEF IFR OR WORSE WOULD OF COURSE BE POSSIBLE IN ANY TSRA...ALONG WITH GUSTY WINDS. OUTLOOK.../SATURDAY NIGHT THROUGH WEDNESDAY/... LOW PRESSURE WILL LIKELY BRING SHOWER/THUNDERSTORM RESTRICTIONS LATE SAT NIGHT AND SUN. ADDITIONAL RESTRICTIONS ARE POSSIBLE MON AS THE ASSOCIATED COLDFRONT CROSSES. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...NONE. OH...NONE. PA...NONE. WV...NONE. && $$

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