995  
FXUS61 KPBZ 010234  
AFDPBZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PITTSBURGH PA  
1034 PM EDT SUN APR 30 2017  
   
SYNOPSIS
 
 
A COLD FRONT WILL BRING WIDESPREAD SHOWERS AND THUNDERSTORMS  
MONDAY, FOLLOWED BY MUCH COOLER TEMPERATURES THROUGH LATE WEEK.  
 

 
   
NEAR TERM /THROUGH MONDAY/
 
 
QUICK EVENING UPDATE TO INCLUDE MENTION OF ISOLATED SHOWERS  
ACROSS WESTERN ZONES BASED ON LATEST GUIDANCE AND MAKE MINOR  
ADJUSTMENTS TO HOURLY TEMPERATURES. OTHERWISE, THE FORECAST  
REMAINS ON TRACK. PREVIOUS DISCUSSION FOLLOWS..  
 
WARM AND HUMID CONDITIONS EXPECTED OVERNIGHT IN SOUTHWEST FLOW  
AHEAD OF AN APPROACHING COLD FRONT.  
 
LARGE CLOSED MID LEVEL CIRCULATION WILL MOVE TOWARD THE WESTERN  
GREAT LAKES LATER MONDAY, WITH A STRONG SHORTWAVE MOVING  
NORTHEAST AHEAD OF THE MAIN LOW. THIS WILL HELP PUSH AN  
OCCLUDING FRONT ACROSS THE REGION DURING THE AFTERNOON. HAVE  
UPDATED THE HWO FOR THE SLIGHT TO ENHANCED RISK OF SEVERE  
THUNDERSTORMS FROM SPC, WITH IMPRESSIVE WIND FIELDS, ONLY  
QUESTION REMAINS EXACT TIMING AND AMOUNT OF AVAILABLE CAPE.  
 
OUTSIDE OF THUNDERSTORMS INCREASING PRESSURE GRADIENT WITH  
DAYTIME MIXING WILL ALLOW FOR GUSTY WINDS, WITH COOLER  
TEMPERATURES.  
 

 
   
SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/
 
 
THE FRONT WILL CLEAR THE AREA MONDAY EVENING, WITH SHOWERS  
DIMINISHING. STRONG COLD AIR ADVECTION WILL DIVE IN BEHIND THE  
EXITING SYSTEM, BRINGING MORE CLOUDS AND THE RISK FOR ADDITIONAL  
SHOWERS. THE CLOSED CIRCULATION ALOFT WILL SWEEP EAST THROUGH  
WEDNESDAY MORNING WITH COOLER TEMPERATURES AND SHOWER CHANCES  
MAINLY NORTH OF PITTSBURGH.  
 

 
   
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
 
 
MODELS REMAIN IN GOOD AGREEMENT THAT A SOUTHERN STREAM TROUGH  
DIGGING INTO THE LOWER MISSISSIPPI VALLEY WILL BEGIN TO SPREAD  
MOISTURE NORTH TOWARD THE REGION BY LATER WEDNESDAY. SHOWERS  
WILL BE IN THE FORECAST INTO SUNDAY AS A MEAN MID LEVEL TROUGH  
OR CLOSED LOW SLOWLY SHIFTS NORTHEAST TOWARD NEW ENGLAND.  
TEMPERATURES WILL TREND 5 TO 10 DEGREES BELOW THE SEASONAL  
AVERAGE INTO THE WEEKEND.  
 

 
   
AVIATION /03Z MONDAY THROUGH FRIDAY/
 
 
VFR CONDITIONS ARE EXPECTED THROUGH EARLY MONDAY MORNING IN  
SHORTWAVE RIDGING. CONDITIONS ARE EXPECTED TO DETERIORATE TO  
MVFR/LOCAL IFR AS SHOWERS AND THUNDERSTORMS TRACK ACROSS THE  
REGION WITH A CROSSING COLD FRONT. OH/WV PANHANDLE PORTS SHOULD  
SEE THIS ACTIVITY FROM MID MORNING THROUGH AROUND NOON, WITH AN  
AFTERNOON TIMING EXPECTED ELSEWHERE. CONDITIONS SHOULD RETURN TO  
VFR AFTER THE PRECIP ENDS.  
 
EXPECT GUSTY S-SW WINDS TO DEVELOP STARTING MONDAY MORNING WITH  
AN INCREASING PRESSURE GRADIENT AND DEVELOPING JET.  
   
OUTLOOK
 
 
RESTRICTIONS ARE LIKELY WITH THU/FRI LOW PRESSURE.  
 

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

 
 

 
 
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