504
FXUS61 KPBZ 160538
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1238 AM EST FRI JAN 16 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 /06Z FRIDAY THROUGH TUESDAY/
KEY MESSAGES...
1) VFR RETURNING THROUGH MOST OF FRIDAY WITH SCATTERING AND A
TEMPORARY DEPARTURE OF SNOW
2) TURNING GUSTY FRIDAY AFTERNOON WITH A PERIOD OF LATE EVENING
SHEAR POSSIBLE
3) SNOW RETURNS AGAIN LATE FRIDAY INTO EARLY SATURDAY
------------------------------------------------------------
VFR HAS RETURNED TO ALL SITES SAVE FKL/DUJ WHERE LINGERING LIGHT
SNOW AND HIGH-END MVFR DECKS CONTINUE WITH LAKE ENHANCEMENT IN
NORTHWEST FLOW. WIND DIRECTION WILL BACK OVERNIGHT AND CUT OFF
THE LAKE SOURCE RETURNING VFR AFTER 08Z. QUICKLY IN THE WAKE OF
THAT, A SHIELD OF SCT TO BKN CLOUD COVER AROUND 3.5 KFT IS
FILLING IN ON THE NOSE OF 925-850 MB WARM ADVECTION, AND
EXPECTATION IS THAT THIS REMAINS >3 KFT BASED ON HI RES
SOUNDINGS AND UPSTREAM OBSERVATIONS.
BY MORNING, THE STRATUS SHOULD CLEAR AND GIVE WAY TO A
THICKENING AND GRADUALLY LOWERING DECK OF MID-LEVEL CLOUDS
THROUGH THE DAY AHEAD OF APPROACHING LOW PRESSURE. GUSTS LOOK
TO PICK UP IN THE AFTERNOON WITH MIXING HEIGHTS TAPPING INTO
25-35 KNOTS OF LOW LEVEL FLOW. SNOW CHANCES THEN INCREASE TOWARD
THE END OF THE CURRENT TAF PERIOD AS A WARM FRONT LIFTS
THROUGH. PROBABILITY FOR SNOW INCREASES AFTER 00Z SATURDAY, BUT
DRY LOW-LEVEL AIR AT ONSET WITH LARGE T/TD SPREADS WILL WORK
AGAINST FLAKES MAKING IT TO THE GROUND FOR THE FIRST HOUR OR
TWO; CEILINGS AS A RESULT WILL TAKE A BIT TO COME DOWN AS WILL
VISIBILITY. PROBABILITY FOR MVFR EVENTUALLY REACHES 80+% WITH
SATURATION AND PREVAILING IFR ONLY AROUND 40%, BUT INTERMITTENT
PERIODS OF IFR WITHIN STEADIER SNOW ARE HIGHER LIKELIHOOD AFTER
06Z. DECOUPLING MAY ALSO LEAD TO A BRIEF BOUT OF SHEAR IN THE
EARLY OVERNIGHT PERIOD UNDER A SHORT-LIVED 35-45 KNOT LOW LEVEL
JET.
OUTLOOK...
RESTRICTIONS ARE FAVORED TO HOLD ON THROUGH SATURDAY WITH LOW-
LEVEL COLD ADVECTION REINFORCING MVFR CEILINGS AND SCATTERED
AFTERNOON SNOW SHOWERS CONTINUING. DRIER AIR WORKS IN IN THE
WAKE OF A COLD FRONT PASSAGE SATURDAY EVENING WHICH SHOULD THEN
ERODE CEILINGS AND RETURN VFR CONDITIONS OVERNIGHT.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...COLD WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR WVZ514.
DISCUSSION...FRAZIER/LUPO
AVIATION...MLB
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