935
FXUS61 KPBZ 291858
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
158 PM EST SAT NOV 29 2025
SYNOPSIS
DRY WEATHER CONTINUES THROUGH THIS AFTERNOON, SNOW IS EXPECTED
TONIGHT, TRANSITIONING TO RAIN AFTER SUNRISE SUNDAY. BRIEF AND
LIGHT ACCUMULATIONS ARE EXPECTED FOR MOST, THOUGH 3 TO 4 INCHES
ARE POSSIBLE ALONG THE I-80 CORRIDOR. MORE WIDESPREAD SNOW IS IS
EXPECTED WITH ANOTHER SYSTEM ON TUESDAY.
NEAR TERM /THROUGH SUNDAY/
KEY MESSAGES:
- SNOW RETURNS TONIGHT, TRANSITIONING TO RAIN SUNDAY
- 1-3 INCHES NORTH OF I-80, LOCALLY UP TO 4 INCHES IN SPOTS
- GLAZE OF ICE ACCUMULATION POSSIBLE IN RIDGES OF SW PA AND
NORTHERN WV, WHERE A WINTER WEATHER ADVISORY IS NOW IN EFFECT
FROM 3AM UNTIL NOON SUNDAY.
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SURFACE HIGH PRESSURE IS EXITING TO OUR EAST TODAY AS LOW
PRESSURE DEEPENS OVER THE UPPER MS VALLEY, CROSSING INTO THE
GREAT LAKES TONIGHT. PRECIPITATION CHANCES WILL INITIALLY
OVERSPREAD THE AREA FROM THE WEST LATE THIS EVENING AND
OVERNIGHT -- INITIALLY AS SNOW FOR MOST BEFORE TRANSITIONING TO
RAIN AND A RAIN/SNOW MIX WITH STRONG WARM ADVECTION SUNDAY
MORNING AND AFTERNOON. THERE ARE TWO PRIMARY AREAS OF CONCERN
WITH THIS SYSTEM: 1) ACCUMULATING SNOW ALONG/NORTH OF I-80, AND
2) POTENTIAL FOR FREEZING RAIN IN THE RIDGES OF SOUTHWEST PA AND
NORTHERN WV.
REGARDING CONCERN NUMBER 1, AT THIS TIME GUIDANCE CONTINUES TO
SUGGEST THE MOST LIKELY SNOWFALL AMOUNTS RANGE FROM 1-3 INCHES
ALONG AND NORTH OF THE I-80 CORRIDOR WITH LOWER TOTALS FARTHER
SOUTH. ENSEMBLE PROBABILITIES FOR EXCEEDING 3 INCHES CONTINUE
TO DECREASE, WITH THE NBM NOW SHOWING A LESS THAN 10% CHANCE.
ADDITIONALLY, THE NBM NOW ONLY SHOWS A 20-30 PERCENT CHANCE OF
EXCEEDING 2 INCHES. THAT SAID, HI-RES GUIDANCE CONTINUES TO
SUGGEST THE POSSIBILITY FOR SOME CONVECTIVE SNOW SHOWERS SUNDAY
MORNING BEFORE TRANSITIONING TO RAIN OR ENDING COMPLETELY.
THEREFORE, A FEW LOCALIZED AMOUNTS UP TO 4 INCHES CAN'T BE
ENTIRELY RULED OUT, BUT GIVEN SUCH LOW PROBABILITIES AND THE
ISOLATED NATURE OF THESE HIGHER TOTALS (SHOULD THEY OCCUR), THE
DECISION NOW IS TO CONTINUE HOLDING OFF ON ISSUING ANY WINTER
HEADLINES NORTH OF I-80.
REGARDING CONCERN NUMBER 2 FROM ABOVE, INVESTIGATION INTO
MODEL SOUNDINGS IN THE RIDGES OF SOUTHWEST PA AND NORTHERN WV
SUGGEST THAT SUPERCOOLED WATER CONTENT IN CLOUDS AND NEAR-
SURFACE THERMAL PROFILES MAY BE SUPPORTIVE OF FREEZING RAIN
MIXING IN WITH RAIN/SNOW, PRIMARILY DURING OVERNIGHT AND EARLY
MORNING HOURS SUNDAY. THEREFORE, A GLAZE OF ICE ACCUMULATION
WILL BE POSSIBLE AND A WINTER WEATHER ADVISORY HAS BEEN ISSUED
FOR THESE AREAS FROM 3AM UNTIL NOON SUNDAY.
WIDESPREAD PRECIPITATION SHOULD END THROUGH SUNDAY AFTERNOON AS
THE COLD FRONT CROSSES. LINGERING RAIN AND SNOW SHOWERS, FAVORED
NORTH OF PITTSBURGH, WILL TRANSITION BACK TO ALL SNOW AS TEMPS
COOL BEHIND THE FRONT TOWARDS SUNSET SUNDAY EVENING. ANY ADDITIONAL
SNOWFALL AMOUNTS WOULD BE LIGHT.
SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/
KEY MESSAGES:
- SNOW NORTH OF PITTSBURGH TRAILS OFF SUNDAY NIGHT
- DRY AND COLD MONDAY
- POPS RISE AGAIN BY MONDAY NIGHT
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SNOW SHOWERS LINGER NORTH OF PITTSBURGH IN NW FLOW EARLY SUNDAY
NIGHT. AN ADDITIONAL 0.5-1" WILL BE POSSIBLE ALONG THE I-80
CORRIDOR OVERNIGHT. POPS TRAIL OFF OVERNIGHT AS DRY ADVECTION
TAKES OVER AND SHORT LIVED HIGH PRESSURE NOSES IN ACROSS THE
OHIO RIVER VALLEY.
HIGH PRESSURE CONTINUES DRY CONDITIONS THROUGH THE DAY MONDAY
BUT FEW BREAKS IN THE CLOUD COVER ARE FAVORED BEHIND OUR EXITING
SYSTEM AND AHEAD OF OUR NEXT SYSTEM. HIGH TEMPS REMAIN WELL
BELOW AVERAGE FOR THIS TIME OF YEAR, PEAKING IN THE LOW TO MID
30S.
ANOTHER SHORTWAVE BUILDS THROUGH THE FLOW AND MOVES EASTWARD
TOWARDS THE GREAT LAKES BY MONDAY AFTERNOON. AT THE SFC, THIS
DRAGS A LOW UP FROM THE GULF COAST AND THROUGH THE SOUTHEAST,
POSITIONING US ON THE FAR NORTHERN EDGE. AS SUCH POPS BEGIN TO
INCREASE QUICKLY OVERNIGHT MONDAY NIGHT WITH SNOW FAVORED TO
BEGIN BEFORE SUNRISE.
LONG TERM /TUESDAY THROUGH SATURDAY/
KEY MESSAGES:
- ACTIVE PATTERN CONTINUES
- SNOW AND RAIN RETURN TUESDAY, THEN AGAIN THURSDAY/FRIDAY
- BELOW NORMAL TEMPERATURES THROUGH THE PERIOD
-------------------------------------------------------------------
THE EXACT STORM TRACK THROUGH THE SOUTHEAST AND OFF THE
ATLANTIC COAST WILL DETERMINE THE EXACT PROGRESSION OF
PRECIPITATION TYPES FOR TUESDAY. AT THIS TIME MODELS HAVE
SHIFTED SOUTHWARD OVER THE LAST 24 HOURS PUTTING MORE OF THE
REGION IN THE COLD AIR AND RAISING CHANCES FOR ACCUMULATING
SNOWFALL.
STOUT WARM ADVECTION UP THE RIDGES HINTS AT THE CHANCE TO SEE
SOME FREEZING RAIN IN OUR WV RIDGES OVERNIGHT MONDAY. ICE
ACCUMULATIONS OF A GLAZE UP TO A FEW HUNDREDTHS COULD BE
POSSIBLE BY TUESDAY MORNING.
AS TEMPERATURES RISE DURING THE DAY AREAS MAINLY SOUTH OF
PITTSBURGH CAN SEE A CHANGEOVER TO A RAIN/SNOW MIX, WITH AREAS
NORTH LIKELY TO STAY ALL SNOW. SNOWFALL TOTALS ARE LIKELY
HIGHEST NORTH OF PITTSBURGH AND ESPECIALLY ALONG THE I-80
CORRIDOR, WHERE PROBABILITIES FOR ADVISORY LEVEL SNOW ARE THE
HIGHEST AND PROBABILITIES FOR WARNING LEVEL SNOW PEAK BETWEEN
10-20%.
UNCERTAINTY INCREASES CLOSER TO PITTSBURGH AS THE EXACT
LOCATION OF THE TRANSITION ZONE WILL LARGELY FACTOR INTO HOW
MUCH SNOW AREAS SEE. THE NOTED SOUTHERN SHIFT IN MODELING OVER
THE LAST 24 HOURS WOULD FAVOR MORE SNOW IN THE METRO AND
CURRENTLY PAINTS THE RELATIVE MINIMUM OF SNOW ACROSS THE MON
VALLEY. IF THIS TREND CONTINUES, IN A COLDER AND SNOWIER
SOLUTION, WE COULD END UP NEEDING A WINTER WEATHER ADVISORY FOR
MUCH OF THE FORECAST AREA OUTSIDE OF THE MON VALLEY. HOWEVER, WE
WILL HAVE TO WAIT AS FLUCTUATIONS IN EXACT TRACK WILL SHIFT THE
TRANSITION ZONE AND TOTALS OVER COMING FORECAST CYCLES.
POPS BEGIN TO TRAIL OFF BY TUESDAY NIGHT AS HIGH PRESSURE
ENTERS THE OHIO VALLEY. THIS RETURNS DRY CONDITIONS FOR
WEDNESDAY BEFORE SNOW CHANCES PICK UP AGAIN LATE WEEK WITH
ANOTHER PASSING SYSTEM. TEMPERATURES ARE LIKELY TO REMAIN BELOW
AVERAGE THROUGH THE PERIOD FAVORING DAYTIME HIGHS IN THE LOW TO
MID 30S.
AVIATION /18Z SATURDAY THROUGH THURSDAY/
INCREASING MID-LEVEL CLOUD COVER IS OVERSPREADING THE AREA FROM
THE WEST AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM, WHICH
ARRIVES TONIGHT AND BRINGS WIDESPREAD PRECIPITATION CHANCES TO
THE AREA AS WELL AS INCREASING PROBABILITIES FOR MVFR TO IFR
RESTRICTIONS. THERMAL PROFILES SUGGEST INITIAL PRECIPITATION MAY
FALL AS SNOW AND HAVE SOME POTENTIAL FOR ACCUMULATION (FAVORING
ZZV/BVI/FKL/DUJ) BEFORE WARM ADVECTION AIDES IN A CHANGEOVER TO
RAIN SUNDAY MORNING. PRECIPITATION ENDS WITH THE PASSAGE OF A
COLD FRONT SUNDAY AFTERNOON, BUT A FEW POST-FRONTAL RAIN/SNOW
SHOWERS MAY LINGER AT FKL/DUJ INTO SUNDAY EVENING.
OUTLOOK...
VFR RETURNS TO THE AREA ON MONDAY AS HIGH PRESSURE MOVES ACROSS
THE AREA. THIS IS QUICKLY FOLLOWED BY YET ANOTHER LOW PRESSURE
SYSTEM, WHICH MOVES INTO THE AREA AND BRINGS ANOTHER ROUND OF
WINTRY MIX AND ASSOCIATED RESTRICTIONS ON TUESDAY.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...WINTER WEATHER ADVISORY FROM 3 AM TO NOON EST SUNDAY FOR
PAZ074-076.
OH...NONE.
WV...WINTER WEATHER ADVISORY FROM 3 AM TO NOON EST SUNDAY FOR
WVZ512-514.
SYNOPSIS...AK
NEAR TERM...CERMAK
SHORT TERM...AK
LONG TERM...AK
AVIATION...CERMAK
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