942
FXUS61 KPBZ 100550
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1250 AM EST MON NOV 10 2025
SYNOPSIS
RAIN WILL TRANSITION TO SNOW OVERNIGHT AS COLDER AIR MOVES INTO
THE REGION. LESS THAN AN INCH IS EXPECTED BEFORE DAWN, BUT LATER
THIS AFTERNOON AND TONIGHT, COLDER AIR ALOFT WILL ENHANCE LAKE
EFFECT BANDS AND SNOW IN THE RIDGES OF WEST VIRGINIA AND
PENNSYLVANIA, WHERE A WINTER WEATHER ADVISORY IN EFFECT FOR
PORTIONS OF THE REGION THROUGH TUESDAY.
NEAR TERM /THROUGH TODAY/
KEY MESSAGES:
- RAIN WILL CHANGE OVER TO SNOW EARLY THIS MORNING.
- LIGHT ACCUMULATION EXPECTED BEFORE DAWN
- LAKE-EFFECT SNOW BANDS EXPECTED TO INCREASE MONDAY
AFTERNOON/EVENING
- WINTER WEATHER ADVISORY FOR COUNTIES NEAR I-80 AND ALONG THE
RIDGES
---------------------------------------------------------------
COLD AIR ADVECTION CONTINUES THE TRANSITION FROM RAIN TO SNOW
FROM NW TO SE ACROSS THE REGION, WITH SNOW JUST NOW BEING
OBSERVED LOCALLY HERE AT OUR LOCAL NWS OFFICE AND THE AIRPORT.
NO IMPACTS YET AS LATEST OBSERVATIONS SHOW SURFACE TEMPERATURES
AND DEWPOINTS LARGELY ABOVE FREEZING, ACCUMULATION HAS BEEN
MINIMAL. SLIGHT ACCUMULATIONS HAVE BEEN NOTED ON AREA WEBCAMS
NORTHWEST OF PITTSBURGH ON GRASSY SURFACES.
WITH THE RELATIVELY WARM SURFACE TEMPERATURES, 2" GROUND (SUB
SFC) TEMPERATURES STILL LARGELY IN THE LOW TO MID 40S, AND
FORECAST ROAD SURFACE TEMPERATURES (METRO ROADCASTS) FORECAST TO
REMAIN ABOVE FREEZING OVERNIGHT AND DURING THE DAY,
ACCUMULATIONS ON ROADWAYS SHOULD BE MORE LOCALIZED/MINIMAL
THROUGH THE MORNING; GRASSY AND ELEVATED SURFACES WILL BE
IMPACTED FIRST.
TEMPERATURES SHOULD RISE ONLY A COUPLE DEGREES OR REMAIN
STAGNANT DURING THE DAY WITH CONTINUED COLD ADVECTION AND
SCATTERED SNOW SHOWERS. AS THE DEEP UPPER-LEVEL TROUGH
TRANSITIONS OVER THE REGION TODAY, TEMPERATURES ALOFT WILL DROP
CONSIDERABLY (15+ DEGREES C). WITH NORTHWESTERLY FLOW OVER LAKE
ERIE, WATER TEMPERATURES HOVERING AROUND +12 TO +14 DEG C, AND
850MB TEMPERATURES AROUND -10 TO -12 DEG C, LAKE ENHANCEMENT
WILL BE LIKELY. THE MOST IMPACTED AREAS WILL BE MERCER, VENANGO,
AND FOREST COUNTIES. A WINTER WEATHER ADVISORY IS CURRENTLY IN
EFFECT FOR THESE COUNTIES. THE NORTHWESTERLY WIND IS ALSO
FAVORABLE FOR OROGRAPHIC ENHANCEMENT ACROSS THE LAUREL RIDGES
WITH THE POTENTIAL FOR ADVISORY CRITERIA SNOW AS WELL, SO
MAINTAINED THE ADVISORY PREVIOUSLY ISSUED FOR THE LAURELS TO
COME INTO EFFECT AT 1 PM TODAY. STRONG GRADIENT WINDS IN THE
WAKE OF THE SURFACE LOW WILL MAINTAIN BREEZY CONDITIONS ACROSS
THE REGION.
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/
KEY MESSAGES:
- SNOW SHOWERS EXPECTED THROUGH TUESDAY
- TRAVEL IMPACTS COULD OCCUR IN AREAS UNDER ANY LAKE-ENHANCED SNOW
BANDS, OR IN THE RIDGES
- TEMPERATURES WILL BE 10-20 DEGREES BELOW NORMAL
----------------------------------------------------------------
COLDER AIR ALOFT BRINGS THE DGZ DOWN INTO THE BOUNDARY LAYER BY
THIS EVENING, RESULTING IN THE POTENTIAL FOR MORE EFFICIENT
SNOW GROWTH. THIS COMBINED WITH ROAD SURFACE TEMPERATURES
FORECAST TO DROP BELOW FREEZING BY MID EVENING (UNLIKE THIS
MORNING WHERE ROADS WERE WELL ABOVE FREEZING) RAISES THE
POTENTIAL FOR ACCUMULATIONS ON AREA ROADWAYS. THE AREAS OF MOST
CONCERN ARE WHERE THE CURRENT ADVISORIES ARE IN PLACE, BUT
SPECIFIC AREAS WHERE BANDS SET UP ARE A LOW CONFIDENCE FORECAST
AT THIS POINT. WE'LL HAVE A BETTER GRASP ON LOCATION LATER
TODAY ONCE MESOSCALE FEATURES AND HI-RES MODELS PROVIDE THE
INFORMATION NEEDED TO BETTER FORECAST LOCATIONS.
CURRENTLY, THE NBM HAS A 20-50% CHANCE FOR >3" OVER 24HRS FOR
THE NORTHERN ADVISORY AREA, 50% TO 75% FOR THE RIDGES. >3"
PROBABILITIES FOR 72 HOURS CHANGE LITTLE FOR THE RIDGES, BUT
BUMP UP TO 60% TO 80% NORTH OF I-80. THE MEAN IS ROUGHLY 4-6"
FOR BOTH ADVISORY AREAS.
TUESDAY MORNING WILL BE COLD, WITH TEMPERATURES FORECAST TO BE
IN THE LOW TO MID-20S AND APPARENT TEMPERATURES IN THE LOW
TEENS. TEMPERATURES WILL THEN WARM INTO THE MID TO UPPER 30S
DURING THE DAY. THIS WILL BE 10-20 DEGREES BELOW NORMAL.
LATER ON TUESDAY, THE FLOW WILL BACK TO THE WEST- SOUTHWEST AND
THE MOST EFFICIENT LAKE AND TERRAIN ENHANCEMENT IS TURNED NORTH
OF THE REGION.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
KEY MESSAGES:
- UNSETTLED WEDNESDAY AND THURSDAY WITH OCCASIONAL RAIN/SNOW
CHANCES MAINLY NORTH OF I-80
- TEMPERATURES CLOSER TO NORMAL HEADING INTO THE WEEKEND
-------------------------------------------------------------------
BROAD UPPER TROUGHING IS THEN EXPECTED TO PERSIST ACROSS AREAS FROM
THE UPPER MIDWEST INTO NEW ENGLAND THROUGH EARLY THURSDAY.
OCCASIONAL RAIN/SNOW CHANCES POSSIBLE NORTH OF I-80 AS INDIVIDUAL
SHORTWAVES ROTATE THROUGH THE TROUGH.
TEMPERATURES WILL MODERATE BY MID WEEK, HOWEVER, THEY WILL REMAIN
BELOW NORMAL HIGHS (TYPICALLY LOW 50S). HEADING INTO THE WEEKEND,
NEAR NORMAL TEMPERATURES SHOULD RETURN ALONG WITH DRY WEATHER AS AN
UPPER-LEVEL RIDGE MOVES INTO THE REGION.
AVIATION /06Z MONDAY THROUGH FRIDAY/
A COLD FRONT WILL CROSS THROUGH THE REGION WEST TO EAST THROUGH
09Z AND USHER A RAIN-TO-SNOW CHANGEOVER OF PRECIPITATION WHERE
IT IS OCCURRING. ADDITIONALLY, CONVERGENCE ALONG THE LINE FAVORS
A PERIOD OF IFR CONDITIONS JUST PRIOR TO AND A FEW HOURS BEHIND
ITS PASSAGE. STEEPENING LAPSE RATES IN THE POST-FRONTAL
ENVIRONMENT FAVORS GRADUAL RISES TO MVFR AT MOST TERMINALS BY
15Z AND CHANCES FOR VFR OUTSIDE OF SNOW SHOWERS BY 21Z.
THE MORE DIFFICULT ASPECT OF THE FORECAST IS IDENTIFYING WHERE
PRECIPITATION WILL OCCUR AS UPPER TROUGHING DEEPENS JUST WEST OF
THE REGION; NOTABLY, WHERE WILL UPPER DYNAMICS FAVOR NARROW
BANDING THAT MAY RESULT IN HEAVIER SNOW THAT REDUCES
VISIBILITIES TO LESS THAN 1 MILE AND PROVIDES SNOWFALL RATES
AROUND 0.5"/HR. VARIANCE REMAINS ON DEVELOPMENT/POSITIONING BUT
HI-RES MODELS SLIGHTLY FAVOR THIS FEATURE JUST SOUTH OF I-70
BETWEEN 08Z-13Z (IMPACTING ZZV/MGW).
A LACK OF JET INDUCED LIFT AND WEAK 850MB FLOW MAY CREATE A
LULL IN SNOW ACTIVITY BETWEEN 15Z-20Z BEFORE STRONGER NW FLOW
THEREAFTER FAVORS INCREASED SNOW SHOWERS WITH LOCALIZED LAKE
EFFECT BANDS. AGAIN, TIMING AND LOCATION VARIATION REMAIN HIGH,
BUT ANY HEAVY BAND/SHOWER COULD RAPIDLY REDUCE VISIBILITY AND
HAVE SNOWFALL RATES UP TO 1"/HR.
OUTLOOK...
LOW VFR TO MVFR RESTRICTIONS ARE HIGHLY LIKELY OVERNIGHT MONDAY
INTO TUESDAY WITH COLD NW FLOW, WITH LOCALIZED LAKE EFFECT BANDS
POTENTIALLY CAUSING FURTHER RESTRICTIONS (LOCATION FAVORS NW
PA). HEIGHT RISES AND DRY ADVECTION THROUGH TUESDAY NIGHT WILL
REDUCE SHOWER COVERAGE AND INCREASE PROBABILITIES FOR VFR
CONDITIONS.
OUTSIDE OF WEAK SHORTWAVE MOVEMENT INDUCING MVFR CIGS AND SNOW
SHOWERS IN NORTHWEST PA WEDNESDAY, VFR IS FAVORED INTO THE
WEEKEND UNDER THE INFLUENCE OF HIGH PRESSURE.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...WINTER WEATHER ADVISORY UNTIL 1 PM EST TUESDAY FOR PAZ007>009.
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM EST
TUESDAY FOR PAZ074-076.
OH...NONE.
WV...WINTER WEATHER ADVISORY UNTIL 1 PM EST TUESDAY FOR WVZ510>514.
SYNOPSIS...88
NEAR TERM...88
SHORT TERM...88
LONG TERM...88/LUPO
AVIATION...FRAZIER
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