993  
FXUS61 KPBZ 221428  
AFDPBZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PITTSBURGH PA  
1028 AM EDT THU JUN 22 2017  
   
SYNOPSIS
 
 
SCATTERED SHOWERS AND STORMS ARE FORECAST THIS AFTERNOON. THE  
REMNANTS OF CINDY MAKE THEIR WAY INTO OUR REGION TONIGHT INTO  
SATURDAY. HEAVY RAIN IS POSSIBLE FRIDAY. DRY WEATHER MAKES A  
RETURN LATE SATURDAY WITH COOLER WEATHER SUNDAY.  
 

 
   
NEAR TERM /UNTIL 6 PM THIS EVENING/
 
 
SHOWERS AND STORMS TRACKING ALONG THE LAKE ERIE SHORELINE WILL  
CONTINUE TO BE THE PRIMARY IMPACT TODAY. LATEST HIGH RESOLUTION  
GUIDANCE TRACKS THIS AREA ACROSS NORTHERN SECTIONS THIS  
AFTERNOON /DURING PEAK HEATING/. DRY MID LEVELS MAKE DAMAGING  
WINDS THE PRIMARY HAZARD. DELTA THETA-E VALUES AROUND -25 ARE  
BELOW THE FREEZING LEVEL SO ITS GOING TO TAKE AN ICY CORE TO GET  
WELL ABOVE THE 13KFT IN ORDER TO ATTAIN SEVERE LEVELS. RICH LOW  
LEVEL MOISTURE WILL YIELD DOWNPOURS WITH ANY STORM. THE CLUSTER  
OF SHOWERS AND STORMS THIS MORNING OVER SOUTHWESTERN PA  
PRODUCED NEARLY AN INCH OF RAIN, ILLUSTRATING HOW EFFICIENT THE  
ATMOSPHERE IS. TEMPERATURES ARE ON TRACK WITH MINIMAL CHANGES.  
 

 
   
SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/
 
 
MORE SUBSTANTIAL UPPER LEVEL ENERGY WILL STREAM NORTHWARD FROM  
THE LOWER OHIO VALLEY TONIGHT. THESE WAVES WILL FOLLOW  
THE INTENSIFYING SOUTHWEST FLOW ALOFT, AS THE REMNANTS OF TS  
CINDY MOVE OVER THE LOWER MISSISSIPPI VALLEY. DEEP MOISTURE,  
TROPICAL IN NATURE, WILL ALSO STREAM NORTHWARD WHICH WILL BRING  
WIDESPREAD RAIN AND STORMS TO THE AREA LATE TONIGHT THROUGH  
FRIDAY NIGHT. WARM RAIN PROCESS WILL DEVELOP ON FRIDAY,  
CREATING A SCENARIO FOR VERY EFFICIENT RAINFALL. AS THE RAIN  
OVERSPREADS THE REGION, A SURFACE COLD FRONT WILL MOVE ACROSS  
THE UPPER MIDWEST, REACHING WESTERN OHIO BY LATE IN THE  
AFTERNOON. IT IS A GOOD BET THAT RAINFALL WILL INTENSIFY LATE  
TONIGHT AND THEN AHEAD OF THE BOUNDARY FRIDAY AFTERNOON, SO THE  
EASTWARD PROGRESSION OF THE FRONT WILL NEED TO BE MONITORED  
CLOSELY IN FUTURE MODEL RUNS. IN ADDITION TO CLOSELY WATCHING  
THE PROGRESSION OF THE FRONT, WHERE THE REMNANTS OF TS CINDY GO,  
ONCE IT PHASES IN WITH THE UPPER LEVEL FLOW, WILL ALSO BE  
CRITICAL.  
 
IT WILL TAKE ALL OF FRIDAY NIGHT FOR THE FRONT TO EXIT TO THE  
EAST, MEANING THE RISK FOR HEAVY RAIN WILL CONTINUE INTO EARLY  
SATURDAY.  
 
DRIER AIR SAGS THROUGH THE AREA ON SATURDAY BEHIND THE EXITING  
FRONT. THIS WILL ALLOW FOR THE AREA TO FINALLY START TO DRY OUT  
AND COOL DOWN.  
 

 
   
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/
 
 
A STARK SHIFT IN THE UPPER LEVEL PATTERN LOOKS TO OCCUR BY EARLY  
NEXT WEEK. MODEL AND ENSEMBLE PROJECTIONS ALL FAVOR DEEP  
TROUGHING SETTLING OVER THE REGION BY THAT JUNCTURE. WITH THIS,  
MUCH COLDER AIR ALOFT COMBINED WITH NORTHWESTERLY SURFACE FLOW  
WILL MEAN TEMPERATURES WELL BELOW NORMAL WITH CHANCES OF SHOWERS  
AS COLD AIR ALOFT MIGRATES THROUGH THE REGION.  
 

 
   
AVIATION /14Z THURSDAY THROUGH MONDAY/
 
 
VFR IS EXPECTED THROUGH THE PERIOD OUTSIDE OF POSSIBLE SCATTERED  
SHOWERS/THUNDERSTORMS MAINLY NORTH OF KPIT AS A STALLED FRONTAL  
BOUNDARY LIFTS BACK TO THE NORTH.  
   
OUTLOOK
 
 
WIDESPREAD RESTRICTIONS ARE LIKELY FRIDAY AND FRIDAY NIGHT WITH  
THE ENCROACHMENT OF A COLD FRONT.  
 

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

 
 

 
 
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