510  
FXUS61 KPBZ 141855  
AFDPBZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PITTSBURGH PA  
255 PM EDT WED APR 14 2021  
   
SYNOPSIS
 
 
RAIN CHANCES WILL REMAIN SOUTH OF PITTSBURGH TODAY, WITH WIDESPREAD  
RAIN POSSIBLE ON THURSDAY WITH CROSSING LOW PRESSURE.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
300MB JET DIVERGENCE EVIDENT ON SPC MESOANALYSIS AND ASSOCIATED LOW  
LEVEL FRONTOGENESIS IS DRIVING RAIN SHOWERS SOUTH OF THE PA BORDER  
THIS AFTERNOON. LIGHT, WIDESPREAD RAIN IS EXPECTED TO CONTINUE IN  
THAT REGION THROUGH TONIGHT AS A COLD FRONT IS STALLED DUE TO ITS  
RELATIVE POSITION IN AN OCCLUDING LOW PRESSURE SYSTEM.  
 
GENERALLY, FOR THE REST OF THE OH VALLEY, SHORTWAVE RIDGING AND MUCH  
DRIER AIR WILL ERODE CLOUD COVER RESULTING IN LOWER (THAN RECENT)  
TEMPERATURE OVERNIGHT, BUT NEAR CLIMATOLOGICAL VALUE.  
 

 
   
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/
 
 
VORTICITY ADVECTION ASSOCIATED WITH THE AFOREMENTIONED LOW PRESSURE  
WILL ARRIVE ALOFT IN THE REGION THURSDAY MORNING, AIDING ISO/SCT  
SHOWER DEVELOPMENT, WITH THE HIGHEST CHANCE BEING NEAR I80 AND IN  
HIGHER TERRAIN WITH AN UPSLOPE COMPONENT. THIS PRECIPITATION CHANCE  
WILL LAST THROUGH FRIDAY, TAPERING GRADUALLY.  
 
NOTABLY, A NWLY COMPONENT OF FLOW WILL USHER IN MUCH COLDER AIR, AS  
850MB TEMPS PLUNGE TO -4 TO -6 DEG C. CONTINUED TREND TO SIDE WITH  
LOWER TEMPERATURE GUIDANCE AS A RESULT, WITH MANY LOCATIONS  
STRUGGLING TO REACH 50 DEGREES. THERMAL PROFILES SUGGEST PORTIONS OF  
THE I-80 CORRIDOR AND HIGHER TERRAIN COULD SEE SNOW MIXED IN AMID  
CONTINUED COLD ADVECTION FRIDAY MORNING, BUT ACCUMULATION WILL BE  
LIGHT AND LIMITED TO THE RIDGES OF WV.  
 
DRY CONDITIONS AND A CLEARING SKY IS GENERALLY EXPECTED FRIDAY NIGHT  
WITH INCREASING SUBSIDENCE AND HEIGHT RISES AS THE UPPER LOW SHIFTS  
TOWARD THE ATLANTIC.  
 

 
   
LONG TERM /SATURDAY THROUGH TUESDAY/
 
 
PERIODIC RAIN CHANCE WITH NEAR TO SLIGHTLY BELOW SEASONAL AVERAGE  
TEMPERATURE IS LIKELY INTO EARLY NEXT WEEK AS A PROGRESSIVE FLOW  
ALLOWS FOR A SERIES OF SHORTWAVES TO IMPACT THE REGION.  
 

 
   
AVIATION /19Z WEDNESDAY THROUGH MONDAY/
 
 
VFR SHOULD PREVAIL AT MOST PORTS GIVEN DRY LOWER LEVELS AS NOTED IN  
RECENT SFC DEWPOINT OBS, INFLUENCED BY WEAK LLVL SHORTWAVE RIDGING.  
THE EXCEPTION WOULD BE NEAR MGW, WHERE SFC CONVERGENCE AND ASSOCIATED  
RIGHT ENTRANCE JET STREAK ASCENT SHOULD MAINTAIN SHOWERS AND  
POTENTIAL MVFR THROUGH TONIGHT. INTENSIFYING PRESSURE GRADIENT WILL  
SUPPORT INCREASING WIND TOWARDS THE END OF THE TAF PERIOD.  
   
OUTLOOK
 
 
PERIODIC RESTRICTIONS AND RAIN CHANCES ARE LIKELY THROUGH FRIDAY AS  
AN UPPER TROUGH DEEPENS OVER THE REGION.  
 

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

 
 

 
 
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