395
FXUS61 KPBZ 191718
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1218 PM EST FRI DEC 19 2025
SYNOPSIS
DROPPING TEMPERATURES IN THE WAKE OF A COLD FRONT TODAY.
SCATTERED SNOW SHOWERS EXPECTED THROUGH EARLY SATURDAY. WIND
GUSTS WILL DECREASE AFTER DARK.
NEAR TERM /THROUGH TONIGHT/
KEY MESSAGES:
- WIND ADVISORY AND HIGH WIND WARNING IN EFFECT TIL MIDNIGHT
- SNOW SHOWERS EXPECTED
- FALLING TEMPERATURES WILL CREATE SOME SLICK SPOTS THIS
AFTERNOON/TONIGHT; SPS IN EFFECT
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TEMPERATURES HAVE FALLEN SHARPLY OVER THE PAST 6 HOURS, DROPPING
FROM THE MID-40S INTO THE MID-20S IN THE WAKE OF A PASSING COLD
FRONT. RAIN SHOWERS EARLIER THIS MORNING HAVE TRANSITIONED TO
SNOW AS COLD AIR ADVECTION STRENGTHENS AND MOISTURE RESIDES
WITHIN THE DENDRITIC GROWTH ZONE. POCKETS OF SHALLOW INSTABILITY
MAY ALLOW BRIEF, HEAVIER BURSTS OF SNOW WITHIN SHOWERS,
TEMPORARILY REDUCING VISIBILITY AND CREATING A QUICK COATING ON
SURFACES. UPSLOPE FLOW WILL SUPPORT SNOWFALL ACCUMULATIONS
EXCEEDING ONE INCH ALONG THE RIDGES, ACCOMPANIED BY BLOWING SNOW
LATE TONIGHT.
A HIGH WIND WARNING AND WIND ADVISORY WILL REMAIN IN EFFECT
THROUGH MIDNIGHT DUE TO A TIGHTENED PRESSURE GRADIENT WITH THIS
SYSTEM. A SPECIAL WEATHER STATEMENT (SPS) IS ALSO IN EFFECT TO
SLICK ROAD CONDITIONS DURING THE EVENING COMMUTE.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/
KEY MESSAGES:
- DRY WEATHER AND MODERATING TEMPERATURE SATURDAY
- PRE-FRONTAL SHORTWAVE EXPECTED SATURDAY NIGHT
- PASSING COLD FRONT EXPECTED SUNDAY MORNING.
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DRY AND QUIET WEATHER EXPECTED SATURDAY. TEMPERATURES WILL
CLIMB TO ABOVE AVERAGE WITH WARM ADVECTION FROM THE SOUTHWEST.
THE SHORTWAVE TROUGH WILL CROSS THE AREA OVERNIGHT SATURDAY INTO
SUNDAY ALONG WITH A SURFACE COLD FRONT. CURRENT MODEL ANALYSIS
SUGGESTS THE FRONTAL BOUNDARY IS MOISTURE STARVED AND ANY
PRECIPITATION MAY BE TIED TO SOME LAKE ERIE ENHANCEMENT AMID
COLD ADVECTION AND ONLY IMPACT NORTHWEST PA. SUNDAY MORNING
TEMPERATURES WILL BE NEAR OR SLIGHTLY ABOVE AVERAGE WITH HEAVY
CLOUD COVERAGE.
QUIET WEATHER IS EXPECTED SUNDAY INTO SUNDAY NIGHT AS CONDITIONS
GRADUALLY CLEAR.
LONG TERM /MONDAY THROUGH THURSDAY/
KEY MESSAGES:
- RAIN/SNOW CHANCES MONDAY/TUESDAY WITH WARMING TEMPERATURES.
- WARMER TEMPERATURES AND RAIN CHANCES ON CHRISTMAS.
-------------------------------------------------------------------
THERE REMAINS FAIRLY HIGH CONFIDENCE IN A WARMING TREND INTO MONDAY
AND TUESDAY WITH ENSUING UPPER RIDGING. ALL THE WHILE, THERE IS
ALSO CONFIDENCE IN A QUICK SHORTWAVE LOW PASSING TO THE NORTH.
WITH A "MOST LIKELY" ONSET TIME MONDAY NIGHT, THERE IS A CHANCE
PRECIPITATION BEGINS AS SNOW BEFORE WARMER AIR CHANGES OVER
CHANCES TO ALL RAIN BY TUESDAY. CHANCES OF SEEING ANY SNOW
ACCUMULATIONS ARE ONLY 30% TO 50% FOR THE I-80 CORRIDOR FOR NOW
AND LESS ELSEWHERE. CHANCES OR RAIN OR LIQUID EQUIVALENT SNOW
HAVE A >75% CHANCE OF BEING LESS THAN A QUARTER OF AN INCH, SO
NO HYDROLOGIC IMPACTS ARE EXPECTED. ANY LOW PROBABILITY SCENARIO
OF SNOW IMPACTS WOULD RELY ON AN UNDER- REPRESENTATION OF
RIDGING AND A MORE SOUTHERN LOW TRACK. AT THIS TIME, THIS
REMAINS VERY UNLIKELY.
A BRIEF PAUSE IN RIDGING IS EXPECTED IN WAKE OF THE LOW ON
WEDNESDAY. TEMPERATURES ARE FORECAST SIMILAR TO TUESDAY
(SLIGHTLY ABOVE AVERAGE). RAIN CHANCES INCREASE AGAIN INTO
WEDNESDAY AND THURSDAY (CHRISTMAS) WITH MOST ENSEMBLES HINTING
THE ARRIVAL OF ANOTHER SHORTWAVE, THOUGH TIMING AND INTENSITY OF
THIS STILL REMAINS LOW CONFIDENCE IN FAIRLY PROGRESSIVE FLOW.
MOST ENSEMBLES HAVE THE PRECIPITATION WINDOW SOMETIME BETWEEN
CHRISTMAS EVE AND CHRISTMAS NIGHT WITH LOW QPF (LESS THAN 0.5
INCHES). WHAT DOES REMAIN HIGH CONFIDENCE, HOWEVER, IS THAT
CHRISTMAS DAY WILL SEE TEMPERATURES AROUND 15 DEGREES WARMER
THAN NORMAL. SO, CHANCES OF A WHITE CHRISTMAS SEEM NULL.
FORECAST CONFIDENCE BREAKS DOWN INTO THE NEW YEAR, WITH MOST
ENSEMBLES SHOWING A RETURN TO EASTERN TROUGHING IN RESPONSE TO A
WEST-CENTRAL CONUS RIDGE (~50%). BUT A COUPLE OF OTHER CLUSTERS
CONTINUE QUASI-ZONAL FLOW IN AN ACTIVE STORM TRACK (25%), WHILE
OTHER FAVOR A CONTINUATION OF EASTERN RIDGING (25%). THIS LACK OF
CONFIDENCE IN THE LONG RANGE PATTERN IS REFLECTED BEYOND THE
FORECASTS PERIOD IN THE CPC 8-14 DAY AND 3-4 WEEK OUTLOOKS.
AVIATION /18Z FRIDAY THROUGH WEDNESDAY/
KEY MESSAGES:
- SNOW SHOWERS THROUGH THIS EVENING; MVFR TO IFR DUE TO CIGS/VIS
- GUSTY CONDITIONS CONTINUE THROUGH MIDNIGHT
- VFR GRADUALLY RETURNS TO MOST AREAS OVER THE WEEKEND UNDER
BUILDING HIGH PRESSURE
------------------------------------------------------------
SNOW SHOWERS WILL PERSIST ON AND OFF THROUGH THE DAY; MVFR TO
IFR CIGS/VIS EXPECTED WITH BOUNDARY LAYER MOISTURE AND SNOW.
AFTER 00Z, SNOW CHANCES WILL DECREASE FROM WEST TO EAST WITH A
BUILDING RIDGE. WIND GUSTS WILL ALSO SUBSIDE WITH A RELAXED
PRESSURE GRADIENT. BVI/FKL/DUJ WILL LIKELY HOLD ON TO MVFR TO
IFR RESTRICTIONS BETWEEN 00Z TO 06Z DUE TO LINGERING SNOW
SHOWERS IN CLOSE PROXIMITY TO THE LAKE.
OUTLOOK...
WIDESPREAD VFR EXPECTED BETWEEN 12Z TO 00Z SATURDAY UNDER HIGH
PRESSURE.
A PASSING SHORTWAVE SATURDAY NIGHT INTO EARLY SUNDAY
COULD REDUCE CIGS NORTH OF PIT BRIEFLY.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR PAZ074-076-078.
OH...NONE.
WV...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR WVZ512-513.
HIGH WIND WARNING UNTIL MIDNIGHT EST TONIGHT FOR WVZ514.
SYNOPSIS...HEFFERAN
NEAR TERM...HEFFERAN
SHORT TERM...HEFFERAN
LONG TERM...MILCAREK
AVIATION...HEFFERAN
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