210  
FXUS61 KPBZ 081849  
AFDPBZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PITTSBURGH PA  
149 PM EST THU DEC 8 2022  
   
SYNOPSIS
 
 
CLOUDY CONDITIONS WILL PREVAIL TODAY; A WEAK DISTURBANCE COULD  
RESULT IN LIGHT PRECIPITATION SOUTH OF I-70 THIS EVENING. PERIODIC  
PRECIPITATION CHANCES, INCLUDING A WINTRY MIX FOR PORTIONS OF  
THE REGION, INCREASE LATE FRIDAY INTO SATURDAY.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
HIGH PRESSURE OVER THE GREAT LAKES IS EXPECTED TO ADVANCE DRIER  
AIR FROM THE NORTH INTO THE REGION TODAY. A HEAVY CLOUD DECK  
WILL REMAIN WITH COLD AIR ALOFT, CONDENSING WHATEVER WATER  
VAPOR WE HAVE AVAILABLE WITHIN THE BOUNDARY LAYER.  
 
A CROSSING SHORTWAVE MAY BRING LIGHT RAIN CHANCES FOR AREAS  
SOUTH OF INTERSTATE 70 LATER THIS AFTERNOON. THE NBM 95TH  
PERCENTILE IS RANGING ON PRECIP AMOUNTS TO BE BETWEEN A TRACE TO  
0.20 INCHES IN THE RIDGES OF WEST VIRGINIA THROUGH MIDNIGHT.  
HIGH TEMPERATURES ARE EXPECTED TO BE AROUND 5 DEGREES ABOVE  
SEASONABLE LEVELS.  
 

 
   
SHORT TERM /FRIDAY THROUGH SUNDAY/
 
 
HIGH PRESSURE CENTERED OVER ERN CANADA IS PROGGED TO RIDGE  
FURTHER ACROSS THE UPPER OHIO VALLEY REGION FRIDAY, WITH MAINLY  
DRY WEATHER EXPECTED TO START THE DAY. THE RIDGE SHOULD SHIFT  
EWD THROUGH THE DAY, AS A SHORTWAVE TROUGH AND ASSOCIATED  
WEAKENING SFC LOW APPROACHES THE REGION FROM THE UPPER MIDWEST.  
 
RAIN CHANCES COULD INCREASE FRIDAY NIGHT WITH THE CROSSING  
SHORTWAVE. HOWEVER, THE NBM OVER THE LAST 12 TO 24 HOURS HAS  
BEEN TRENDING DOWN ON PRECIP CHANCES/OVERALL QPF DUE TO THE  
INFLUENCE OF THE RIDGE. IF PRECIP DOES OCCUR, IT WILL LIKELY BE  
LIGHT. NOTE, AREAS ALONG THE HIGHEST TERRAIN OF THE LAUREL  
HIGHLAND AND WV COULD SEE A BRIEF PERIOD OF LIGHT FREEZING RAIN  
WITH COLDER TEMPERATURES IN UPSLOPING ERLY FLOW IF PRECIP DOES  
FORM.  
 
ANY ONGOING PRECIP SHOULD END SATURDAY MORNING AS THE SHORTWAVE  
EXITS THE REGION, AND FLAT RIDGING BRIEFLY BUILDS ACROSS THE  
UPPER OH VALLEY REGION AHEAD OF THE NEXT MIDWESTERN SHORTWAVE.  
TEMPERATURES FOR BOTH FRIDAY/SATURDAY SHOULD REMAIN SEASONABLE  
OR SLIGHTLY ABOVE AVERAGE WITH A BUILDING RIDGE.  
 

 
   
LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/
 
 
LONG TERM MODEL GUIDANCE PROJECT A SHORTWAVE TROUGH, AND ITS  
ASSOCIATED COLD FRONT, QUICKLY EXITS THE REGION SUNDAY NIGHT  
INTO MONDAY. MODELS HAVE BEEN CONSISTENT OVER THE LAST FEW RUNS ON  
LAKE ENHANCED FOLLOWED BY LAKE EFFECT SNOW IN THE WAKE OF THE  
FRONT EARLY NEXT WEEK.  
 
PROLONG RIDGING TUESDAY THROUGH EARLY WEDNESDAY WILL KEEP THE  
REGION DRY, GRADUALLY WARM IS ANTICIPATED THROUGH THIS PERIOD AS  
WINDS SHIFT FROM EAST TO SOUTHWEST.  
 
OVER THE LAST 24HRS THE NBM HAS DELAYED THE TIMING OF  
PRECIPITATION, ASSOCIATED WITH A ROBUST (BUT SLOW MOVING) LOW  
PRESSURE SYSTEM DEVELOPING ACROSS THE PLAINS. WITH THIS LATEST  
FORECAST UPDATE, HIGHER PRECIP CHANCES ARE CURRENTLY TIMED TO  
START AFTER DAWN WEDNESDAY. WITH COLD/DRY AIR, FROM LINGERING  
HIGH PRESSURE INSTILLED ACROSS THE REGION, PRECIP TYPE MAY START  
AS A WINTRY MIX FOR A PERIOD OF TIME BEFORE SWITCHING OVER TO  
RAIN UNDER WARM ADVECTION. HOWEVER, NOTE THAT CONFIDENCE IS NOT  
VERY HIGH DURING THE WEDNESDAY TIME PERIOD. SOME ENSEMBLE MODELS  
ARE EVEN DELAYING AN INCREASE IN PRECIP CHANCES UNTIL THURSDAY.  
 
   
AVIATION /17Z THURSDAY THROUGH MONDAY/
 
 
CIGS GENERALLY IN THE MVFR RANGE CONTINUE ACROSS AREA TERMINALS.  
SOME SLIGHT IMPROVEMENT HAS BEEN OBSERVED SINCE DAWN WITH MIXING  
AND DRIER AIR NEAR THE SURFACE, BUT OTHERWISE MOISTURE REMAINS  
TRAPPED UNDERNEATH A STOUT INVERSION AROUND 850MB, OR ABOUT  
3000FT AGL.  
 
IMPROVEMENT TO VFR IS EXPECTED LATER THIS AFTERNOON AND EVENING  
AS DRY ADVECTION AND MIXING INCREASES BEHIND THE REINFORCING  
FRONT, AND AS SFC HIGH PRESSURE BEGINS TO BUILD IN. MVFR CIGS  
ARE POSSIBLE AGAIN LATE TONIGHT FOR FKL AND DUJ AS THE LOWER  
LEVELS BECOME SATURATED.  
   
OUTLOOK.
 
 
VFR EXPECTED FRIDAY BEFORE RESTRICTION POTENTIAL RETURNS WITH  
RAIN FRIDAY NIGHT, AND AGAIN SATURDAY NIGHT AND SUNDAY. VFR  
RETURNS MONDAY UNDER HIGH PRESSURE.  
 

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

 
 

 
SYNOPSIS...HEFFERAN  
NEAR TERM...HEFFERAN  
SHORT TERM...HWOPBZ/07 LONG TERM...HEFFERAN AVIATION...BROWN  
 
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