640
FXUS61 KPBZ 290733
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
233 AM EST SAT NOV 29 2025
SYNOPSIS
AFTER DRY WEATHER TODAY, 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 TODAY/
KEY MESSAGES:
- CHILLY TEMPERATURES AND BRIEFLY DRY CONDITIONS
---------------------------------------------------------------
SNOW AND MOST FLURRIES HAVE ENDED THIS MORNING. DESPITE CLOUD
COVER, LINGERING COLD ADVECTION WILL HELP DROP AREA LOWS INTO
THE UPPER TEEN AND LOWER 20S. SKIES WILL PARTIALLY SCATTER FOR
THE FIRST PART OF TODAY AS WE EXPERIENCE BRIEFLY DRY
CONDITIONS. AFTERNOON TEMPERATURES SHOULD END UP A COUPLE
DEGREES WARMER THAN FRIDAY, BUT STILL 10+ DEGREES BELOW AVERAGE.
SHORT TERM /TONIGHT THROUGH MONDAY/
KEY MESSAGES:
- SNOW RETURNS TONIGHT, TRANSITIONING TO RAIN SUNDAY
MORNING/AFTERNOON
- 3-4 INCHES POSSIBLE NORTH OF I-80
- DRY ON MONDAY
----------------------------------------------------------------
SURFACE HIGH PRESSURE WILL QUICKLY EXIT EAST TODAY AS LOW
PRESSURE DEVELOPS ACROSS 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. HIGH TEMPERATURES MAY PUSH INTO THE LOWER
40S FOR MUCH OF THE REGION BEFORE COOLING ONCE AGAIN BEHIND A
COLD FRONT.
THE OVERALL FORECAST HASN'T CHANGED MUCH OVER THE LAST SEVERAL
CYCLES, BUT THERE WAS A NOTABLE DOWNWARD TREND IN SNOWFALL WITH
THE 01Z NBM RUN. SNOWFALL TOTALS WILL BE HIGHEST ACROSS NW
PENNSYLVANIA, WHERE PROFILES REMAIN COLD ENOUGH TO SUPPORT SNOW
OR A RAIN/SNOW MIX THROUGH MOST OF THE MORNING IF NOT EARLY
AFTERNOON. IN SOME LOCATIONS (E.G. PARTS OF MERCER AND VENANGO
COUNTIES), THIS WILL BE FALLING ON TOP OF SEVERAL INCHES OF
SNOWPACK. AT THIS TIME, GENERALLY 2-4" IS EXPECTED ACROSS
MERCER, VENANGO, AND FOREST COUNTIES, WITH NORTHERN PORTIONS OF
BUTLER, CLARION, AND JEFFERSON EXCEEDING 2". LESS THAN 2" IS
EXPECTED ELSEWHERE NORTH OF PITTSBURGH, WITH AN INCH TO A
DUSTING FARTHER SOUTH.
OUTSIDE OF THE I-80 CORRIDOR, IMPACTS FROM SNOWFALL WILL BE
NEGLIGIBLE AS SNOW QUICKLY TRANSITIONS TO RAIN SUNDAY MORNING.
SLICK CONDITIONS COULD PERSIST INTO THE AFTERNOON NORTH OF I-80
AS RAIN FALLS ON SNOW AND COLD GROUND WITH AIR TEMPERATURES
STILL IN THE MID/UPPER 30S. GIVEN BORDERLINE ADVISORY CRITERIA
(40-45% FOR NORTHERN MERCER/VENANGO) AND THE DOWNWARD TREND,
HAVE HELD OFF OF ISSUING A WINTER WEATHER ADVISORY FOR NOW.
WIDESPREAD PRECIPITATION SHOULD END THROUGH THE AFTERNOON AS THE
COLD FRONT CROSSES. LINGERING RAIN AND SNOW SHOWERS, FAVORED
NORTH OF PITTSBURGH WILL TRANSITION BACK TO ALL SNOW AS
TEMPERATURES COOL BEHIND THE FRONT AND AFTER SUNSET SUNDAY
NIGHT. AN ADDITIONAL 0.5-1" IS POSSIBLE ALONG THE I-80 CORRIDOR
OVERNIGHT.
DRY WEATHER RETURNS (BRIEFLY, AGAIN...) ON MONDAY AS HIGH
PRESSURE BUILDS ACROSS THE GREAT LAKES. CLOUDS WILL LIKELY
PERSIST THROUGH THE DAY, AND TEMPERATURES REMAIN WELL BELOW-
AVERAGE WITH HIGHS IN THE 30S AND LOWS IN THE 20S.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
KEY MESSAGES:
- ACTIVE PATTERN CONTINUES
- SNOW AND RAIN RETURN TUESDAY, THEN AGAIN THURSDAY/FRIDAY
- BELOW NORMAL TEMPERATURES THROUGH THE PERIOD
-------------------------------------------------------------------
THE ACTIVE PATTERN CONTINUES MIDWEEK WITH YET ANOTHER CHANCE
FOR SNOW AS A SHORTWAVE CROSSES THE GREAT LAKES AND A SOUTHEAST
US SURFACE LOW TRACKS UP THE COAST. PRECIPITATION CHANCES RETURN
LATER MONDAY NIGHT AND TUESDAY, EXITING BY TUESDAY NIGHT.
UNCERTAINTY REMAINS WITH REGARDS TO QPF AND SNOW TOTALS, BUT
CONFIDENCE IN THE COLDER SOLUTION IS INCREASING. SNOW IS LIKELY
TO BEGIN MONDAY NIGHT, WITH AREAS SOUTH OF PITTSBURGH
TRANSITIONING TO A RAIN/SNOW MIX LATER TUESDAY MORNING. SNOWFALL
TOTALS WILL LIKELY BE HIGHEST NORTH OF PITTSBURGH ALONG THE I-80
CORRIDOR, WHERE PROBABILITIES FOR 3+ INCHES IS AROUND 40-50%.
UNCERTAINTY IN TOTALS INCREASES NEAR THE PITTSBURGH METRO AND
AREAS FARTHER SOUTH, AS PRECIP TYPE TRANSITION TIMING WILL COME
INTO PLAY.
DRY WEATHER SHOULD RETURN WEDNESDAY WITH WEAK RIDGING AND
BUILDING SFC HIGH PRESSURE, BEFORE MINOR SNOW CHANCES RETURN
THURSDAY AND FRIDAY WITH THE NEXT FRONTAL SYSTEM.
TEMPERATURES WILL BE BELOW AVERAGE THROUGH THE PERIOD.
AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
BROAD CYCLONIC FLOW AROUND A MID-LEVEL CLOSED LOW CENTERED JUST
NORTH OF MAINE HAS CONTINUED TO PROVIDE FAVORABLE NORTHWEST FLOW
WITH COLD AIR OVER THE LAKES FOR LAKE EFFECT SNOW SHOWERS. THESE
HAVE BEEN MORE CELLULAR IN NATURE THIS EVENING BRINGING
TEMPORARY RESTRICTIONS TO IFR VIS WITHIN THE HEAVIER SHOWERS.
CONDITIONS OUTSIDE OF SNOW SHOWERS HAVE BEEN VFR WITH A MID-
LEVEL BKN TO OVC CLOUD DECK. HEADED INTO TONIGHT, EXPECT THAT
INCREASING SUBSIDENCE FROM APPROACHING HIGH PRESSURE TO OUR
SOUTHWEST WILL CUT OFF THE DEPTH OF THE MOISTURE AND DISSIPATE
SNOW SHOWERS SOUTH OF I-80. VFR CONDITIONS WILL PREVAIL
OVERNIGHT AT ALL SITES, SAVE FKL/DUJ, WITH THE MID-LEVEL CLOUD
DECK SLOWLY BREAKING UP AND WIND DIMINISHING TO AROUND 5-10
KNOTS OVERNIGHT.
FOR FKL/DUJ, EXPECT THAT BKN TO OVC CEILINGS WILL HOVER RIGHT
AROUND 3KFT WITH SOME LAKE EFFECT SNOW SHOWERS ABLE TO HANG ON
THROUGH MIDNIGHT OR SO AND BRINGING TEMPORARY MVFR/IFR
RESTRICTIONS. IMPROVEMENT BACK TO LOW-END VFR IS FAVORED AFTER
THAT, BUT NORTHWEST FLOW WILL STILL KEEP THE HIGHEST CLOUD
COVERAGE AT THOSE TWO SITES.
VFR CONTINUES FOR MOST OF SATURDAY AS WIND BACKS FROM THE WEST
TO ULTIMATELY SOUTHEAST THROUGHOUT THE DAY BUT GENERALLY REMAINS
LIGHT AROUND 5 KNOTS. INCREASING CLOUD COVERAGE WILL OVERSPREAD
FROM THE WEST IN THE AFTERNOON AHEAD OF APPROACHING LOW
PRESSURE.
OUTLOOK...
THE NEXT LOW PRESSURE SYSTEM ARRIVES EARLY SATURDAY NIGHT,
CREATING WIDESPREAD PRECIPITATION CHANCES WITH INCREASING
PROBABILITY FOR ON MVFR TO IFR RESTRICTIONS SATURDAY NIGHT
THROUGH SUNDAY MORNING. 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.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...RACKLEY
NEAR TERM...RACKLEY
SHORT TERM...RACKLEY
LONG TERM...RACKLEY/88
AVIATION...CL
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page