235
FXUS61 KPBZ 100620
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
120 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/
IFR TO LOW MVFR IS EXPECTED, ALONG WITH SCATTERED SNOW SHOWERS,
AS A SECONDARY SURFACE TROUGH CROSSES THE REGION THROUGH EARLY
MORNING.
MORE WIDESPREAD MVFR IS EXPECTED THROUGH MUCH OF THE DAY IN COLD
NW FLOW OFF OF THE GREAT LAKES, AND AS A DEEP UPPER TROUGH
APPROACHES THE UPPER OHIO VALLEY REGION. SCATTERED SNOW SHOWERS
ARE EXPECTED THROUGH THE DAY, WITH MORE NUMEROUS SNOW SHOWERS
NORTH OF I-80 IN THE FLOW OFF OF THE LAKES. INCREASING LAPSE
RATES AND MIXING COULD RETURN CIGS TO LOW VFR FOR A BRIEF PERIOD
DURING THE MID TO LATE AFTERNOON, THOUGH CONDITIONS SHOULD
DETERIORATE TO MVFR AGAIN BY EVENING AS THE UPPER TROUGH
CROSSES.
IN ADDITION, ONE OR MORE LAKE ENHANCED SNOW BANDS ARE EXPECTED
TO DEVELOP MONDAY AFTERNOON, AS MOISTURE INCREASES IN THE
DENDRITIC LAYER. A NNW BOUNDARY LAYER FLOW WILL INITIALLY FOCUS
THIS BAND ACROSS OH, WITH ANOTHER SECONDARY BAND ACROSS NW PA.
THE BAND ACROSS OH IS EXPECTED TO SHIFT EASTWARD THROUGH LATE
AFTERNOON AND EVENING AS THE BOUNDARY LAYER FLOW GRADUALLY BACKS
TO THE WEST BY TONIGHT. THIS SHOULD RESULT IN A REDUCTION TO
IFR VSBYS IN THE MORE INTENSE BAND, ALONG WITH SOME RAPID
ACCUMULATION AN INCH OR TWO OF SNOW WHERE THE BAND PERSISTS.
OUTLOOK...
THE LAKE ENHANCED SNOW BANDS SHOULD GRADUALLY SHIFT NORTHWARD
TONIGHT AS THE BOUNDARY LAYER FLOW CONTINUES TO BACK, AND THE
UPPER TROUGH AXIS SHIFTS EASTWARD. A GRADUAL IMPROVEMENT TO VFR
IS EXPECTED LATER TUESDAY AS A WEAK RIDGE OF HIGH PRESSURE
BUILDS IN. RESTRICTION POTENTIAL RETURNS WEDNESDAY WITH RAIN AND
SNOW SHOWERS UNDER A CROSSING TROUGH. VFR RETURNS THURSDAY AND
FRIDAY UNDER 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...WM
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