846
FXUS61 KPBZ 092352
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
652 PM EST SUN NOV 9 2025
SYNOPSIS
RAIN WILL TRANSITION TO SNOW TONIGHT WITH A PASSING LOW PRESSURE
DISTURBANCE. LESS THAN AN INCH IS EXPECTED BEFORE DAWN. LAKE-
EFFECT SNOW BANDS IS EXPECTED TO INTENSIFY MONDAY AFTERNOON/EVENING.
WINTER WEATHER ADVISORY IN EFFECT FOR PORTIONS OF THE REGION
THROUGH TUESDAY.
NEAR TERM /THROUGH MONDAY/
KEY MESSAGES:
- RAIN WILL CHANGE OVER TO SNOW BETWEEN 7PM AND 11PM TONIGHT
- LIGHT ACCUMULATION EXPECTED BEFORE DAWN
- LAKE-EFFECT SNOW BANDS EXPECTED TO INCREASE MONDAY
AFTERNOON/EVENING
- WINTER WEATHER ADVISORY IN EFFECT FOR COUNTIES NEAR I-80 AND
ALONG THE RIDGES
---------------------------------------------------------------
EVENING UPDATE:
ADVANCING COLD AIR FROM THE WEST WILL INCREASE SNOW CHANCES
OVER THE NEXT 3 HOURS IN EASTERN OHIO. AS OF 6:45PM, SNOW
SHOWERS AND REDUCED VISIBILITY ARE BEING REPORTED IN KNOX AND
LICKING COUNTY, JUST WEST OF ZANESVILLE. WITH CONTINUING
SOUTHWEST FLOW IN THE VICINITY OF PITTSBURGH, PRECIPITATION
TYPE CONTINUES AS RAIN. HOWEVER, THE TRANSITION TO RAIN/SNOW
MIX FOLLOWED BY SNOW WILL LIKELY OCCUR BEETWEEN THE MIDNIGHT TO
2AM TIME PERIOD. WITH WARM SURFACE TEMPERATURES, HAZARDOUS
TRAVEL IS NOT EXPECTED THROUGH DAWN; GRASSY AND ELEVATED
SURFACES WILL BE IMPACTED FIRST.
PREVIOUS DISCUSSION:
FALLING TEMPERATURES AND SNOW SHOWERS ARE EXPECTED TO CONTINUE
INTO MONDAY. ON AVERAGE, 2" GROUND (SUB SFC) TEMPERATURES ARE
STILL IN THE LOW TO MID 40S ACROSS THE REGION, SO ONLY A FEW
TENTHS OF AN INCH (MAINLY ON GRASS AND ELEVATED SURFACES) ARE
EXPECTED BY SUNRISE ON MONDAY IN MOST CASES. THE ELEVATED
SURFACES AND RIDGES WILL CERTAINLY SEE SNOW ACCUMULATION EARLIER
THAN THE LOWER SURFACES.
THE DEEP UPPER-LEVEL TROUGH WILL BEGIN TO TRANSITION OVER THE
REGION MONDAY. DESPITE SOME MINOR MODEL DIFFERENCES, THE
PICTURE REMAINS THE SAME THAT NW FLOW WILL BRING SCATTERED TO
NUMEROUS SNOW SHOWERS ACROSS PORTIONS OF THE OH VALLEY.
BY THE AFTERNOON ON MONDAY, THE WINDS WILL FINALLY SHIFT TO A
WNW TRAJECTORY GIVING THE MAXIMUM UPSLOPE TO THE LAUREL RIDGES
WITH THE POTENTIAL FOR ADVISORY CRITERIA (2-4 INCHES) HERE AS
WELL SO DID ISSUE FOR THE LAURELS TO COME INTO EFFECT AT 18Z
MONDAY.
OVERALL, EXPECTED GUSTY WINDS AS THE LOW EXITS BUT LEAVES A
STRONG GRADIENT OVER THE AREA BEHIND THE LOW. THIS WILL MAKE FOR
30 TO 40 MPH WIND GUSTS.
SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/
KEY MESSAGES:
- SNOW SHOWERS EXPECTED THROUGH TUESDAY
- TRAVEL IMPACTS COULD OCCUR IN AREAS UNDER ANY LAKE-ENHANCED SNOW
BANDS
- TEMPERATURES WILL BE 10-20 DEGREES FAHRENHEIT BELOW NORMAL
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THE DEEP UPPER-LEVEL TROUGH WILL BEGIN TO TRANSITION NORTHEAST OF
THE REGION MONDAY NIGHT. THIS WILL BRING NORTHWESTERLY FLOW OVER
LAKE ERIE WITH SEA SURFACE TEMPERATURES HOVERING AROUND +12 TO +14
DEG C. COMBINED WITH 850MB TEMPERATURES AROUND -10 TO -12 DEG C,
LAKE AND TERRAIN ENHANCEMENT WILL BE LIKELY. THE MOST IMPACTED AREAS
WILL BE MERCER, VENANGO, AND FOREST COUNTIES.
ADDITIONALLY, THE COLDER AIR ALOFT BRINGS THE DGZ DOWN INTO THE
BOUNDARY LAYER, SO MORE EFFICIENT SNOW GROWTH IS POSSIBLE. MESOSCALE
FEATURES (SUCH AS A REINFORCING SURFACE TROUGH) WILL GREATLY AFFECT
SFC TO 850MB FLOW AND THUS THE EXACT POSITION, DURATION, AND
INTENSITY OF ANY HEAVIER FOCUSED LAKE BANDS REMAINS LOW CONFIDENCE
AT THIS TIME. CURRENTLY, THE NBM HAS A 30%-45% FOR >1.5" OF SNOW
ASSOCIATED WITH THE BANDS NORTH OF I-80. WE WILL CONTINUE TO MONITOR
THE EVOLUTION OF THIS SYSTEM AND PATTERN OVER THE COMING FORECAST
PERIODS. LATE ON TUESDAY, THE FLOW WILL BACK TO THE WEST-SOUTHWEST
AND THE MOST EFFICIENT LAKE AND TERRAIN ENHANCEMENT IS TURNED NORTH
OF THE REGION.
TUESDAY MORNING, TEMPERATURES EXPECTED TO BE IN THE LOW TO MID-20S
THEN WARM INTO THE MID TO UPPER 30S DURING THE DAY. TEMPERATURES
WILL BE 10-20 DEGREES FAHRENHEIT BELOW NORMAL. CONDITIONS WILL
REMAIN BREEZY OVERNIGHT KEEPING TEMPERATURES FROM BECOMING AS COLD
AS TUESDAY MORNING.
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
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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 /00Z 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 MONDAY TO 1 PM EST TUESDAY
FOR PAZ074-076.
OH...NONE.
WV...WINTER WEATHER ADVISORY UNTIL 1 PM EST TUESDAY FOR WVZ510>514.
SYNOPSIS...HEFFERAN
NEAR TERM...HEFFERAN/SHALLENBERGER
SHORT TERM...LUPO
LONG TERM...88/LUPO
AVIATION...FRAZIER
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