103  
FXUS61 KPBZ 151842  
AFDPBZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PITTSBURGH PA  
142 PM EST THU JAN 15 2026  
   
WHAT HAS CHANGED  
 
DEVELOPMENT OF A HEAVIER LAKE EFFECT BAND NEAR AND ALONG I-80  
CAUSING CONFIRMED TRAVEL IMPACTS LED TO EXPANSION OF WINTER  
WEATHER ADVISORY INTO CLARION AND JEFFERSON COUNTIES IN  
NORTHWEST PA. ACCUMULATING SNOW IS LIKELY AGAIN FRIDAY INTO  
SATURDAY, WITH PERIODIC SNOW CHANCES THROUGH NEXT WEEK. WIND  
CHILLS HAVE LOWERED FURTHER WITH VERY COLD TEMPERATURES EARLY  
NEXT WEEK. COLD WEATHER ADVISORIES MAY BE NEEDED FOR SOME AREAS.  
 
 
   
KEY MESSAGES  
 
1) LAKE ENHANCED BANDS AND SHOWERS THIS AFTERNOON. COLD TEMPERATURES  
OVERNIGHT WITH A COLD WEATHER ADVISORY CONTINUES FOR E'RN TUCKER COUNTY.  
 
2) ACCUMULATING SNOW LATE FRIDAY AND SATURDAY WITH LOWER  
PROBABILITIES FOR REACHING HEADLINE CRITERIA.  
 
3) LIGHT SNOW CHANCES ACCOMPANY NEAR COLD WEATHER ADVISORY WIND  
CHILLS FOR THE START OF NEXT WEEK.  
 
 
   
DISCUSSION  
 
KEY MESSAGE 1...  
 
THE BOUNDARY LAYER FLOW INDICATES ENHANCEMENT FROM LAKE ERIE, WITH  
AN ADDITIONAL CONNECTION TO LAKE HURON, MAINLY IMPACTING NW PA. THIS  
HAS LED TO ONE BAND DEVELOPING NEAR I-80 THAT HAS CAUSED CONFIRMED  
TRAVEL IMPACTS FROM SLICK ROADS WHICH IS LIKELY TO BE PERSISTENT  
THROUGH THE AFTERNOON. EXPECT TOTAL ACCUMULATIONS BY THE END OF THE  
DAY FROM 2 TO 5 INCHES (LOCALLY HIGHER IF THERE IS STATIONARY  
BANDING FOR MULTIPLE HOURS) NEAR AND NORTH OF THE I-80 CORRIDOR AS  
WELL AS IN THE HIGHER TERRAIN WHERE UPSLOPING IS EXPECTED WITH WNW  
WIND . THE FLOW OFF THE LAKE HAS ALSO IMPROVED INSTABILITY IN  
WESTERN PA ALLOWING FOR POPCORN SNOW SHOWERS TO DEVELOP. THE SNOW  
SHOULD TAPER OFF LATE THIS AFTERNOON AND EVENING AS THE UPPER-LEVEL  
LOW MOVES EAST, FLOW FROM THE LAKES CUTS-OFF, AND DRYING OCCURS IN  
THE DENDRITIC GROWTH ZONE.  
 
TONIGHT, TEMPERATURES ARE EXPECTED TO DROP INTO THE MID-TEENS FOR  
MOST OF THE AREA. A COLD WEATHER ADVISORY FOR EASTERN TUCKER COUNTY  
WV WAS MAINTAINED WHERE COLD TEMPERATURES (7F-12F) AND WIND GUSTS UP  
TO 50 MPH IS FORECAST TO PRODUCE WIND CHILLS AROUND -15F.  
 
KEY MESSAGE 2...  
 
ENSEMBLE MODEL TRENDS FAVOR THE DEVELOPMENT OF A SLOWLY  
DEEPENING UPPER TROUGH THAT GENERALLY SITS OVER THE LOWER OHIO  
RIVER VALLEY THROUGH THE WEEKEND WHILE EMBEDDED SHORTWAVES LIFT  
NE THROUGH THE REGION. THESE WAVES WILL PROVIDE ROUNDS OF  
PRECIPITATION (MAINLY SNOW) STARTING FRIDAY AFTERNOON INTO EARLY  
SUNDAY MORNING RESULTING IN AREAWIDE ACCUMULATIONS. CROSSING OF  
THE UPPER TROUGH AXIS VARIES IN TIMING BETWEEN LATE SUNDAY INTO  
EARLY NEXT WEEK, BUT THE MORE LIKELY ROUTE KEEPS IT NORTH OF THE  
REGION AND LIMITS SNOW POTENTIAL BY SUNDAY EVENING.  
 
GRADUAL ACCUMULATIONS ARE FAVORED DURING THE FRIDAY-SATURDAY  
PERIOD DUE TO A COMBINATION OF WEAKER ASCENT/LIMITED SURFACE  
FORCING, MODEST 700MB WARMING THAT REDUCES SLRS (ALONG WITH  
SOME SURFACE WARM ADVECTION NEAR/SOUTHWEST OF PITTSBURGH PUSHING  
SURFACE TEMPERATURES ABOVE FREEZING), AND WESTERLY FLOW THAT  
PREVENTS/LIMITS LAKE ENHANCEMENT. AS A RESULT, THE PROBABILITY  
FOR EXCEEDING 3" OVER A 24-HOUR PERIOD IS LOW AND ONLY PEAKS  
BETWEEN 30-50% (MAINLY OVER WV HIGHER TERRAIN) FOR THE LATE  
FRIDAY TO SATURDAY AFTERNOON PERIOD, LIMITING POTENTIAL NEED FOR  
WINTER HEADLINES. THOUGH MORE LIKELY OUTCOME IS A HALF INCH TO  
INCH HERE, ANOTHER INCH THERE OVER THE COURSE OF 48 HOURS TO END  
UP IN THE 1 TO 3" (WITH LOCALLY HIGHER) RANGE BY SUNDAY.  
 
KEY MESSAGE 3...  
THOUGH TIMING OF UPPER TROUGH PASSAGE AND DEPTH IS UNCERTAINTY  
FOR THE EARLY WEEK PERIOD, CONFIDENCE IS HIGH FOR A COLD AIR  
MASS TO MOVE INTO THE UPPER OHIO RIVER VALLEY BY SUNDAY AND  
REMAINS IN PLACE THROUGH THE MIDDLE OF NEXT WEEK. THE  
COMBINATION OF THE WELL BELOW NORMAL TEMPERATURE AND PERIODS OF  
GUSTY WIND IS LIKELY TO RESULT IN MULTIPLE PERIODS WITH SINGLE  
DIGIT TO BELOW ZERO WIND CHILLS. PROBABILITIES ARE HIGHEST FOR  
POTENTIAL COLD WEATHER ADVISORY CRITERIA WIND CHILLS BEING  
ACHIEVED LATE MONDAY INTO TUESDAY MORNING,  
 
SNOW CHANCES GENERALLY APPEAR LIMITED DURING THIS PERIOD, BUT  
ALTERATIONS IN TROUGH DEPTH COULD INTRODUCE GREATER INFLUENCE OF  
LAKE EFFECT SNOW DOWN INTO PORTIONS OF WESTERN PA COMPARED TO  
THE FAVORED ALIGNMENT OF ALONG THE LAKE ERIE SHORES.  
 
 
   
AVIATION /18Z THURSDAY THROUGH TUESDAY/  
 
KEY MESSAGES...  
 
1) MVFR/VFR CIGS WITH MVFR/IFR VISIBILITY RESTRICTIONS IN SNOW  
SHOWERS. SNOW SHOWERS EXPECTED TO END THIS EVENING.  
 
2) GUSTY WEST-NORTHWEST WINDS FORECAST TO GRADUALLY EASE.  
 
2) VFR CONDITIONS AREAWIDE BY FRIDAY MORNING.  
 
------------------------------------------------------------  
 
FOR MOST, CEILINGS APPEAR TO BE RISING FASTER THAN EXPECTED WITH  
ALL SITES OBSERVING MVFR/VFR CIGS. RESTRICTIONS ARE DUE TO VISIBILITY  
REDUCTION IN SNOW SHOWERS. A TIGHT PRESSURE GRADIENT CONTINUES  
TO PROMOTE WIND GUSTS TO 25-30 KNOTS THROUGHOUT THE DAY,  
HOWEVER, THIS WILL EASE LATER THIS AFTERNOON AS THE SURFACE LOW  
CONTINUES NORTHEASTWARD AND A RIDGE BUILDS IN.  
 
SNOW CHANCES GENERALLY DIMINISH AROUND OR AFTER SUNSET WITH A  
LOSS OF BUOYANCY, AS WELL AS A WIND DIRECTION CHANGE THAT WILL  
CUT-OFF THE MOISTURE FROM THE GREAT LAKES. CEILINGS WILL  
CONTINUE TO IMPROVE TONIGHT WITH VFR CONDITIONS RETURNING  
EVERYWHERE BY FRIDAY MORNING.  
 
OUTLOOK...  
BRIEF SHORTWAVE RIDGING, DRY ADVECTION AND SOUTHWEST FLOW WILL  
FAVOR VFR CONDITIONS THROUGH MIDDAY FRIDAY BEFORE THE NEXT IN  
A SERIES OF UPPER LEVEL SHORTWAVES BRING SNOW/RESTRICTIONS TO  
THE REGION THROUGH EARLY NEXT WEEK.  
 
 
   
PBZ WATCHES/WARNINGS/ADVISORIES  
 
PA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR  
PAZ007>009-015-016.  
WINTER WEATHER ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR  
PAZ074-076.  
OH...NONE.  
WV...WINTER WEATHER ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR  
WVZ510>514.  
COLD WEATHER ADVISORY UNTIL 7 AM EST FRIDAY FOR WVZ514.  
 
 
 
 
 
DISCUSSION...FRAZIER/LUPO  
AVIATION...LUPO  
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