139  
FXUS61 KPBZ 160554 AAB  
AFDPBZ  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE PITTSBURGH PA  
1254 AM EST MON DEC 16 2024  
   
SYNOPSIS
 
 
RAIN WILL BE ENDING TONIGHT. THE MORNING HOURS WILL BE DRY AND  
MILD BEFORE RAIN RETURNS THIS AFTERNOON AHEAD OF THE NEXT  
SYSTEM. THE ENTIRE WEEK LOOKS UNSETTLED. COLDER TEMPERATURES  
MOVE IN FOR LATE IN THE WEEK.  
 

 
   
NEAR TERM /THROUGH TODAY/
 
 
KEY MESSAGES:  
 
- WARMER AIR SURGING NORTHWARD WILL BRING AN END TO THE FREEZING  
RAIN THREAT.  
- RAIN WILL END OVERNIGHT.  
- WARMER TEMPERATURES AND RAIN RETURNING THIS AFTERNOON.  
 
-------------------------------------------------------------------  
 
500MB LOW WILL SHIFT EASTWARD OVERNIGHT AND HEIGHT RISES WILL  
ENSUE FOLLOWING ITS DEPARTURE. THIS WILL BRING AN END TO THE  
RAIN AS THE NIGHT PROGRESSES. WARMER AIR WILL CONTINUE TO SURGE  
NORTHWARD BEHIND THE EXITING UPPER LOW WHICH WILL ALSO BRING AN  
END TO THE THREAT FOR FREEZING RAIN. NOT MANY REPORTING SITES  
LEFT SHOWING TEMPERATURES AT 32 DEGREES OR BELOW. WILL ALLOW  
ADVISORY TO END AT 06Z AND MAY CANCEL THE WARNING AS  
TEMPERATURES IN TUCKER COUNTY HAVE WARMED. ADDITIONALLY, HAVE  
MADE CHANGES TO POPS OVERNIGHT TO BETTER TIME THE END OF THE  
RAIN. TEMPERATURES HAVE ALSO BEEN UPDATED WITH THE LATEST  
BLENDED GUIDANCE.  
 
A 500MB RIDGE WILL MOVE ACROSS THE REGION THIS MORNING. THIS  
RIDGE WILL PROVIDE A RESPITE FROM THE RAIN AND ALSO SPREAD MUCH  
WARMER AIR ACROSS THE REGION. THE BREAK FROM THE RAIN WILL BE  
SHORT LIVED AS THE NEXT SHORTWAVE TROUGH WILL DIG INTO THE UPPER  
OHIO VALLEY THIS AFTERNOON. RAIN WILL OVERSPREAD THE REGION  
FROM WEST TO EAST IN CONJUNCTION WITH THE WARMER AIR. HIGHS  
TODAY WILL BE 10 TO 15 DEGREES ABOVE NORMAL.  
 
PROBABILITIES OF RAINFALL > 0.30 INCHES TODAY RANGE FROM 40 TO  
80% WITH THE HIGHER VALUES OVER OHIO.  
 

 
   
SHORT TERM /TONIGHT THROUGH WEDNESDAY/
 
 
KEY MESSAGES:  
 
- RAIN ENDS EARLY TUESDAY.  
- ABOVE NORMAL TEMPERATURES TUESDAY.  
- RAIN CHANCES RETURN AGAIN ON WEDNESDAY.  
 
--------------------------------------------------------------------  
 
A SURFACE COLD FRONT, TRAILING TODAY'S SHORTWAVE TROUGH WILL  
SWING THROUGH THE REGION TONIGHT. ONCE THE BOUNDARY EXITS TO  
THE EAST, DRIER AIR WILL OVERSPREAD THE REGION BRINGING AN END  
TO THE THREAT FOR RAIN. COLD AIR ADVECTION BEHIND THE FRONT WILL  
DROP TEMPERATURES ABOUT 5 TO 10 DEGREES ON TUESDAY, BUT READINGS  
WILL REMAIN ABOVE NORMAL.  
 
EXPECT TO SEE A DECREASE IN CLOUD COVER ON TUESDAY.  
 
UNCERTAINTY THEN RAMPS UP QUICKLY WITH TIMING AND STRENGTH OF A  
SECOND, DEEPER TROUGH APPROACHING FROM THE CENTRAL CONUS LATE  
TUESDAY NIGHT. SOME MODELS HOLD IT BACK WITH OTHERS EVEN  
KEEPING IT POSITIVE/NEUTRAL TO OUR WEST ON WEDNESDAY EVENING.  
CHANCE FOR MEASURABLE PRECIPITATION WILL BEGIN WEDNESDAY  
AFTERNOON/EVENING AND CEASE AROUND THURSDAY MORNING/EARLY  
AFTERNOON.  
 

 
   
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
 
 
KEY MESSAGES:  
 
- TEMPERATURES COOLING INTO THE 20S-30S BY THE END OF THE WEEK  
AND INTO THE WEEKEND.  
 
--------------------------------------------------------------------  
 
THERE IS UNCERTAINTY WITH HOW FAST THE UPPER LEVEL TROUGH MOVES OUT  
OF THE AREA AS A SHORTWAVE TROUGH IS EXPECTED TO MOVE INTO THE AREA  
ON FRIDAY AND LINGER THROUGH LATE SATURDAY BRINGING ANOTHER CHANCE  
OF RAIN.  
 
TEMPERATURES ARE EXPECTED TO COOL ON THURSDAY. TEMPERATURES IN  
THE LOW 30S WILL PERSIST THROUGH FRIDAY AND THEN COOL INTO THE  
MID-20S BY SATURDAY.  
 

 
   
AVIATION /06Z MONDAY THROUGH FRIDAY/
 
 
A MIX OF IFR/LIFR CEILINGS (MVFR CLOSER TO THE RIDGES DUE TO  
DOWNSLOPING WINDS) HAS SET UP ACROSS THE AREA AS RAIN SHOWERS  
GRADUALLY DEPART TO THE EAST OVER THE FIRST FEW HOURS OF THE TAF  
PERIOD. ADDITIONALLY, SOME PATCHY FOG HAS DEVELOPED IN A FEW OF  
THE COMMON SPOTS LIKELY DUE TO SATURATED GROUNDS AND LINGERING  
LOW-LEVEL MOISTURE. IMPROVEMENTS IN VISIBILITY ARE EXPECTED  
STARTING IN THE 08Z-10Z TIMEFRAME, ONCE SHOWERS HAVE DEPARTED  
AND LINGERING MIST/DRIZZLE TAPERS OFF. CEILINGS LIKEWISE SEE  
MINOR IMPROVEMENTS THROUGH MONDAY MORNING, THOUGH LATEST HREF  
GUIDANCE MAINTAINS 50-80% PROBABILITIES FOR IFR NORTH OF I-80  
(FKL/DUJ) AND IN AREAS WEST/NORTHWEST OF PIT (NAMELY BVI AND  
ZZV). ELSEWHERE, MVFR IS MORE LIKELY BY THE 14Z-19Z TIMEFRAME.  
 
THIS IMPROVEMENT WILL BE SHORT-LIVED, HOWEVER, AS A BROAD,  
ORGANIZED RAIN SHIELD IS EXPECTED TO RETURN FROM THE WEST  
BEGINNING AROUND 16Z AT ZZV AND CLOSER TO 19-20Z FOR PIT AND  
AREAS EAST. THIS WILL BRING ANOTHER DROP IN CIGS/VSBYS WITH  
PROBABILITIES FOR IFR OR WORSE INCREASING TO 70-90% AREAWIDE  
SAVE FOR THOSE RIGHT ALONG THE RIDGES.  
 
AS WE APPROACH 00Z, THE NOSE OF A 40-50KT LOW-LEVEL JET WILL BE  
PRESSING INTO THE REGION FROM THE WEST WHICH COULD BRING SOME  
LLWS CONCERNS TO AREA TERMINALS DURING OVERNIGHT HOURS. RAIN  
SHOULD TAPER FROM WEST TO EAST AFTER 03Z, ALLOWING SOME  
IMPROVEMENT IN VISIBILITIES TOWARDS THE TAIL END OF THE TAF  
PERIOD, THOUGH LOW CEILINGS WILL LINGER.  
 
OUTLOOK...  
HIGH PRESSURE AND A SHORT-LIVED RETURN OF VFR ARE EXPECTED  
TUESDAY BEFORE ANOTHER WEATHER SYSTEM BRINGS PRECIPITATION AND  
RESTRICTIONS BACK TO THE AREA MID TO LATE WEEK.  
 

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

 
 

 
 
SYNOPSIS...22  
NEAR TERM...22  
SHORT TERM...22/LUPO  
LONG TERM...LUPO  
AVIATION...CERMAK/LUPO/AK  
 
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