767  
FXUS61 KPBZ 091722  
AFDPBZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PITTSBURGH PA  
122 PM EDT TUE AUG 9 2022  
   
SYNOPSIS
 
 
SHOWERS AND THUNDERSTORMS CAN BE EXPECTED TODAY AND WEDNESDAY,  
MAINLY SOUTH OF PITTSBURGH, WITH THE PASSAGE OF A SLOW MOVING  
COLD FRONT. A SECONDARY FRONT ON THURSDAY WILL BRING ISOLATED  
SHOWERS, BUT ALSO WILL BRING A DRIER, MORE REFRESHING AIR MASS  
THAT WILL REMAIN IN PLACE THROUGH THE WEEKEND.  
 

 
 
NEAR TERM /THROUGH TONIGHT/...  
THE FRONTAL BOUNDARY HAS DROPPED THROUGH IDI AND PIT AND  
CONTINUES A SLOW MARCH SOUTH. SHOWERS AND A FEW THUNDERSTORMS ARE  
ALREADY FORMING ALONG AND AHEAD OF THE BOUNDARY AS CAPE  
CONTINUES TO BUILD IN AN UNCAPPED COLUMN. THE SEVERE THREAT  
CONTINUES TO APPEAR NONEXISTENT WITH WEAK FLOW AND MOIST  
SOUNDING PROFILES. HOWEVER, HIGH PWAT, LARGE WARM CLOUD DEPTHS,  
AND STORM MOVEMENT PARALLEL TO THE BOUNDARY POINT TO AN AT LEAST  
LOCALIZED HEAVY RAIN THREAT AS THE FRONT SLOWLY SINKS SOUTH.  
WITHOUT A STRONG SHORTWAVE TO PUSH THE FRONT, THE BOUNDARY  
BECOMES QUASI-PARALLEL TO THE MID-LEVEL FLOW AND STALLS OUT  
NEAR THE MASON-DIXON LINE BY THIS EVENING, WHICH IS WHERE  
LIKELY POPS WILL BE FOCUSED BY 00Z. FLASH FLOOD GUIDANCE VALUES  
IN PORTIONS OF THE SOUTHERN CWA ARE BELOW 2 INCHES IN THREE  
HOURS, WHICH WILL BE ACHIEVABLE IN LOCATIONS WHERE STORMS TRAIN.  
THEREFORE, AFTER COLLABORATION WITH RLX, ELECTED TO HOIST A  
FLOOD WATCH FOR THE SOUTHERN CWA FOR POSSIBLE FLASH FLOOD  
ISSUES.  
 
COVERAGE OF SHOWERS AND STORMS WILL DIURNALLY DECREASE  
DURING THE EVENING, BUT GIVEN THE FRONT AND THE DEEP MOISTURE  
AHEAD OF IT, SOME LOW POPS WILL BE MAINTAINED THROUGH THE NIGHT.  
A SOMEWHAT COOLER AND DRIER AIR MASS WILL BEGIN TO BUILD IN  
OVERNIGHT BEHIND THE BOUNDARY.  
 

 
   
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
 
 
THE FRONT WILL LIKELY CONTINUE TO HANG AROUND THE FAR SOUTHERN  
CWA INTO AT LEAST WEDNESDAY AFTERNOON, BEFORE A RELATIVELY WEAK  
MID-LEVEL SHORTWAVE GIVES THE BOUNDARY A SOUTHWARD PUSH  
BY EVENING. THUS, THE FLOOD WATCH WILL CONTINUE THROUGH THE  
DAYLIGHT HOURS AS SHOWERS/STORMS WITH HEAVY RAIN MAY DEVELOP  
ONCE AGAIN BEFORE THE FRONT CLEARS THE REGION. AGAIN, THERE IS  
VIRTUALLY NO SEVERE THUNDERSTORM THREAT IN THE OVERALL MOIST,  
WEAK FLOW PATTERN. RAIN COVERAGE WILL AGAIN DROP OFF WEDNESDAY  
EVENING WITH THE LOSS OF HEATING, AND THE DRIER AIR MASS WILL  
CONTINUE TO MAKE INCREMENTAL OVERNIGHT PROGRESS.  
 
THE FRONT WILL HAVE FINALLY EXITED THE REGION BY THURSDAY MORNING.  
HOWEVER, A MORE SIGNIFICANT SHORTWAVE TROUGH WILL DROP DOWN FROM THE  
GREAT LAKES, QUICKLY PUSHING A SECONDARY COLD FRONT INTO THE CWA.  
INSTABILITY WILL BE SUFFICIENT FOR SHOWERS AND A FEW THUNDERSTORMS,  
BUT OVERALL LIMITED MOISTURE SHOULD KEEP COVERAGE SCATTERED WITH THE  
BOUNDARY. A MOSTLY PLEASANT NIGHT IS IN STORE FOR THURSDAY NIGHT AS  
THE SKY CLEARS AND AS DEWPOINTS DROP INTO THE 50S.  
 

 
   
LONG TERM /FRIDAY THROUGH MONDAY/
 
 
THE EXTENDED PERIOD WILL FEATURE TEMPERATURES WHICH WILL AVERAGE OUT  
NEAR TO BELOW CLIMATOLOGY INTO EARLY NEXT WEEK. SURFACE HIGH  
PRESSURE WILL PROVIDE DRY WEATHER FOR FRIDAY AND SATURDAY AS A  
SHORTWAVE TROUGH MOVES EAST OF THE REGION. THE VARIOUS  
MODELS/ENSEMBLES SHOW SOME SHORTWAVE ENERGY REINFORCING A NORTHEAST  
CONUS TROUGH STARTING ON SUNDAY, WHICH WILL BRING BACK CHANCES OF  
ISOLATED TO SCATTERED SHOWERS SUNDAY INTO TUESDAY.  
 

 
   
AVIATION /17Z TUESDAY THROUGH SATURDAY/
 
 
SCATTERED SHOWERS WITH AN ISOLATED THUNDERSTORM ARE POSSIBLE  
AHEAD A SLOW MOVING COLD FRONT THAT WILL STALL SOUTH OF  
PITTSBURGH THIS EVENING. ISOLATED SHOWERS WILL POSSIBLE AROUND  
MGW THROUGH WEDNESDAY MORNING BEFORE THE UPPER TROUGH COMPLETES  
ITS PASSAGE LATER IN THE DAY.  
 
MOISTURE CONVERGENCE AROUND THE BOUNDARY WILL GENERALLY PROMOTE  
MVFR/IFR CONDITIONS THROUGH THE PERIOD, THOUGH LOW VFR CIGS ARE  
EXPECTED BY THE LATE AFTN WITH HEATING (OR SUBSIDENCE FOR  
LOCALES NORTH OF THE FRONT). THE LACK OF DRY AIR AT THE SFC WILL  
FOSTER FOG DEVELOPMENT, WITH INTENSITY DICTATED BY THE DEGREE OF  
OVERNIGHT CLEARING, WHICH WILL FAVOR NORTHERN TERMINALS.  
   
OUTLOOK
 
 
VFR CONDITIONS WILL RETURN TO MOST TERMINALS WEDNESDAY AFTN/EVE  
AS THE FRONT FINISHES ITS SOUTHERN PUSH, DRAGGING REMNANT STORMS  
WITH IT. ANOTHER COLD FRONT WILL SWEEP THROUGH THURSDAY WITH  
ADDITIONAL AREAWIDE PRECIP CHANCES BEFORE A PROLONGED VFR PERIOD  
VFR RETURNS UNDER HIGH PRESSURE.  
 

 
   
PBZ WATCHES/WARNINGS/ADVISORIES
 
 
PA...FLOOD WATCH THROUGH WEDNESDAY EVENING FOR PAZ031-075-076.  
OH...FLOOD WATCH THROUGH WEDNESDAY EVENING FOR OHZ068-069.  
WV...FLOOD WATCH THROUGH WEDNESDAY EVENING FOR WVZ004-012-021-  
509>512.  
 

 
 

 
 
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