406
FXUS61 KPBZ 090927
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
427 AM EST SUN NOV 9 2025
SYNOPSIS
RAIN CHANCES WILL BECOME MORE WIDESPREAD THIS MORNING AND
CONTINUE THROUGH THE DAY AS LOW PRESSURE CROSSES THE REGION.
RAIN SHOWERS WILL TRANSITION TO SNOW SHOWERS LATER THIS EVENING
WITH ADVANCING COLD AIR. ACCUMULATING SNOW COULD IMPACT THE
HIGHER TERRAIN AND AREAS ALONG AND NORTH OF I-80 MONDAY INTO
TUESDAY.
NEAR TERM /UNTIL 6 PM THIS EVENING/
KEY MESSAGES:
- RAIN RETURNS
- CHANGEOVER TO SNOW FROM NW TO SE LATER THIS EVENING AND
OVERNIGHT
CHANGE TO SNOW BETWEEN 7PM TO 11PM SUNDAY
---------------------------------------------------------------
SURFACE LOW PRESSURE CURRENTLY CENTERED OVER INDIANA WILL
CONTINUE TO TRACK ENE THIS MORNING, AND IS PROGGED TO BE OVER NW
PA BY MIDDAY AND CENTRAL NY STATE BY THIS EVENING. ASSOCIATED
RAIN AMOUNTS ARE FORECAST TO RANGE FROM A TENTH OR LESS NORTH
AND EAST OF PGH TO UP TO A QUARTER OF AN INCH ACROSS OUR
SOUTHEASTERN OHIO COUNTIES. THIS IS OVER THE COURSE OF THE DAY
SO RAIN WILL BE RELATIVELY LIGHT. PATCHY FOG IS EXPECTED THIS
MORNING AHEAD OF THE LOW WITH SATURATED LOW LEVELS IN THE WARM
SECTOR INVERSION AND DIMINISH WITH INCREASED WINDS AND MIXING ON
THE BACKSIDE OF THE LOW.
SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/
KEY MESSAGES:
- SNOW SHOWERS EXPECTED THROUGH THE PERIOD
- TRAVEL IMPACTS COULD OCCUR IN AREAS UNDER ANY LAKE-ENHANCED
SNOW BANDS
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FROM 9PM TO SHORTLY AFTER MIDNIGHT, RAIN WILL TRANSITION TO
SNOW FROM NW TO SE AS COLDER AIR ADVECTS IN BEHIND THE MENTIONED
LOW. AS THE LOW MOVES NORTHEAST INTO NEW YORK,
NORTH/NORTHWESTERLY WINDS AND RELATIVELY WARM WARM LAKE
TEMPERATURES WILL SET THE STAGE FOR LAKE ENHANCED SNOW SHOWERS.
HIGHER ELEVATIONS IN THE LAUREL HIGHLANDS AND WEST VIRGINIA
MIGHT SEE LIGHT SNOW ACCUMULATION BEFORE MIDNIGHT AS WELL DUE TO
UPSLOPING.
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.
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.
850MB TEMPERATURES ARE EXPECTED TO DROP TO BETWEEN -8 TO -10 DEG C
BY MONDAY, WHILE LAKE ERIE TEMPERATURES HOVER AROUND +12 TO +14 DEG
C. LAKE AND TERRAIN ENHANCEMENT WILL BE LIKELY MONDAY NIGHT INTO
TUESDAY BEFORE FLOW BACKS TO THE W AND THE MOST EFFICIENT LAKE AND
TERRAIN ENHANCEMENT IS TURNED NORTH OF THE REGION.
ADDITIONALLY, THE COLDER AIR ALOFT BRINGS THE DGZ DOWN INTO THE
BOUNDARY LAYER, SO MORE EFFICIENT SNOW GROWTH IS POSSIBLE
BEGINNING MONDAY EVENING. MESOSCALE FEATURES (SUCH AS A
REINFORCING SURFACE TROUGH) WILL GREATLY AFFECT SFC TO 850MB
FLOW AND THUS THE POSITIONING, DURATION, AND INTENSITY OF ANY
HEAVIER FOCUSED LAKE BANDS REMAINS LOW CONFIDENCE AT THIS TIME.
DESPITE THIS, MODELS CONTINUE TO HINT AT THE LIKELIHOOD OF ONE
OR SEVERAL LAKE BANDS YIELDING ENHANCED SNOWFALL NEAR AND SOUTH
OF LAKE ERIE. CURRENTLY, THE NBM HAS A 40%-60% BOTH FOR NORTH
OF I-80 AND THE PA AND WV RIDGES (OVER 24HRS). PROBABILITIES FOR
WARNING LEVEL SNOW (>8" IN 24HRS) IS CURRENTLY LESS THAN 10%. WE
WILL CONTINUE TO MONITOR THE EVOLUTION OF THIS SYSTEM AND
PATTERN OVER THE COMING FORECAST PERIODS.
IN COORDINATION WITH SURROUNDING OFFICES, HAVE HELD OFF FOR NOW
WITH ANY WINTER HEADLINES, BUT WOULDN'T BE SURPRISED IF
EVENTUALLY SOMETHING WILL BE NEEDED TO ADDRESS AREAS WITH LAKE
ENHANCEMENT AND/OR TERRAIN ENHANCEMENT.
LONG TERM /TUESDAY THROUGH SATURDAY/
KEY MESSAGES:
- COLD TEMPERATURES AND SNOW SHOWERS CONTINUE TUESDAY
- UNSETTLED WEDNESDAY AND THURSDAY WITH OCCASIONAL RAIN/SNOW
CHANCES MAINLY NORTH OF PITTSBURGH
- APPARENT TEMPERATURES IN THE TEENS TUESDAY MORNING
-------------------------------------------------------------------
THE SURFACE TROUGH IS WILL SHIFT TO THE NORTHEAST OF THE AREA ON
TUESDAY, AS BOUNDARY LAYER FLOW BACKS TO THE SW AND SNOW CHANCES
DECREASE THROUGH THE DAY. BROAD UPPER TROUGHING IS THEN EXPECTED TO
PERSIST ACROSS AREAS FROM THE UPPER MIDWEST INTO NEW ENGLAND.
OCCASIONAL RAIN/SNOW CHANCES WILL BE POSSIBLE, MAINLY NORTH OF PIT,
AS INDIVIDUAL SHORTWAVES ROTATE THROUGH THE TROUGH.
TEMPERATURES ARE EXPECTED TO BE 15 TO 20 DEGREES BELOW AVERAGE
MONDAY AND TUESDAY, BEFORE MODERATING SOME BY MID WEEK. NEAR
NORMAL TEMPERATURES SHOULD RETURN BY THE WEEKEND.
AVIATION /09Z SUNDAY THROUGH THURSDAY/
PATCHY MVFR FOG IS EXPECTED EARLY THIS MORNING, THOUGH
INCREASING MID AND HIGH LEVEL CLOUDS AHEAD OF APPROACHING LOW
PRESSURE SHOULD KEEP COVERAGE MINIMAL, ESPECIALLY AS CLOUDS
THICKEN AND LOWER TOWARD DAYBREAK.
OTHERWISE, LOW PRESSURE WILL TRACK ACROSS OH AND WESTERN PA
LATER THIS MORNING INTO THE AFTERNOON, WITH SHOWERS AND MVFR
RESTRICTIONS EXPECTED. THE LOW WILL PULL A COLD FRONT ACROSS THE
AREAS AS IT TRACKS NEWD. A DECREASE IN SHOWER ACTIVITY IS
EXPECTED INITIALLY AFTER FROPA, ALONG WITH A WSHFT TO THE W-WSW.
CONTINUED MVFR CIGS ARE EXPECTED TO CONTINUE THROUGH LATE
AFTERNOON IN COLD ADVECTION BEHIND THE FRONT.
ADDITIONAL SHOWERS, AND IFR RESTRICTIONS, ARE EXPECTED THIS
EVENING AS A DEEPENING UPPER LEVEL LOW APPROACHES THE REGION.
CRITICAL THICKNESSES AND MODEL SOUNDINGS INDICATE A CHANGEOVER
TO SNOW SHOWERS IS LIKELY BY LATE EVENING INTO THE OVERNIGHT
HOURS IN COLD ADVECTION, AS IFR CONTINUES.
OUTLOOK...
IFR SHOULD CONTINUE INTO MONDAY MORNING WITH SNOW SHOWERS, WITH
SOME IMPROVEMENT TO MVFR FOR MOST LOCATIONS BY AFTERNOON AS
MIXING LIFTS CIG HEIGHTS. BY LATE AFTERNOON, LAKE ENHANCEMENT
COULD RESULT IN LOCALIZED IFR CONDITIONS IN NARROW SNOW BANDS,
ESPECIALLY ACROSS WRN PA.
THESE CONDITIONS ARE EXPECTED TO CONTINUE INTO TUESDAY BEFORE
THE UPPER LOW TRACKS NE OF THE AREA, AND WIND BACKS TO THE SW
ENDING THE LAKE ENHANCEMENT. PATCHY RESTRICTIONS IN SNOW ARE
POSSIBLE AGAIN TUESDAY NIGHT IN WARM ADVECTION, BEFORE HIGH
PRESSURE RETURNS VFR FOR THURSDAY.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...88
NEAR TERM...88
SHORT TERM...HEFFERAN/88
LONG TERM...LUPO/AK/88
AVIATION...WM
SYNOPSIS...88
NEAR TERM...88
SHORT TERM...HEFFERAN/88
LONG TERM...88/LUPO/AK
AVIATION...WM
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