075
FXUS61 KPBZ 040534
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1234 AM EST THU DEC 4 2025
SYNOPSIS
HIGH PRESSURE PROVIDES DRY AND CHILLY WEATHER TODAY. A FRONTAL
PASSAGE LATE TONIGHT AND EARLY THURSDAY PROVIDES A LIGHT SNOW
ACCUMULATION AND A REINFORCING SHOT OF COLD AIR. BELOW-NORMAL
TEMPERATURES AND ADDITIONAL MAINLY LIGHT SNOW CHANCES SHOULD
CONTINUE INTO EARLY NEXT WEEK.
NEAR TERM /THROUGH TODAY/
KEY MESSAGES:
- ARCTIC COLD FRONT ARRIVING LATE TONIGHT WITH SOME SNOW
- THREAT OF REFREEZING ON ROADS FOR THE MORNING COMMUTE
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A DEEPER UPPER LEVEL TROUGH AXIS SET TO SWIFTLY CROSS THE
EASTERN GREAT LAKES REGION THROUGH THURSDAY AFTERNOON IS PUSH A
FRONTAL BOUNDARY SOUTHEAST EARLY THURSDAY MORNING, FAVORING
4AM-11AM (NORTHWEST TO SOUTHEAST). DESPITE MEAGER MOISTURE
PROFILES, ENOUGH JET AIDED ASCENT PLUS FRONTOGENESIS WILL CREATE
AN AREA OF RELATIVELY LIGHT SNOW SHOWERS AHEAD OF THIS BOUNDARY
WITH POTENTIAL FOR A NARROW, MODERATE SNOW NEAR THE FRONTAL
ZONE. THIS SNOW WILL REACH NORTHWEST PA BY 9PM AND SLOWLY
ADVANCE SOUTHEAST THROUGH THURSDAY MORNING, WITH PEAK
ACCUMULATION RATES OCCURING NEAR THE MORNING COMMUTE.
PROBABILITIES SUGGEST TOTALS WILL BE LIGHT (LESS THAN 20% FOR
MOST LOCATIONS, WITH SOME UPSLOPE POTENTIAL AIDING HIGHER
CHANCES ALONG THE LAUREL HIGHLANDS), MITIGATING ANY HEADLINE
ISSUANCE. HOWEVER, THE COMBINATION OF UP TO 0.25"/HR RATES AND
COLD SURFACE TEMPERATURES MEANS SNOW MAY STICK TO AREA ROADWAYS
(ESPECIALLY ELEVATED SURFACES), POTENTIALLY CREATING SLICK
SURFACES. A SPECIAL WEATHER STATEMENT WAS ISSUED THROUGH THE
MORNING COMMUTE TO HIGHLIGHT POTENTIAL FOR MINOR ROADWAY IMPACTS
DUE TO SNOW (AND RE-FREEZING OF ANY MELTING SNOW) THAT MAY
NECESSITATE SLOWER TRAVEL.
RAPID MOVEMENT OF THE TROUGH EAST AND SUBTLE SHORTWAVE RIDGING
IN ITS WAKE WILL FOSTER RAPID CESSATION OF SNOW AFTER THE
FRONTAL PASSAGE AND GREATER POTENTIAL FOR CLOUD EROSION THROUGH
THE AFTERNOON. ANY SUNSHINE MAY WARM INTERIOR ROOMS BUT WILL BE
OF NO EFFECT TO THE AMBIENT AIR TEMPERATURE; STRONG COLD
ADVECTION BEHIND THE COLD FRONT FAVORS TEMPERATURE READINGS TO
FALL THROUGH THE REST OF THE DAY. COMBINED WITH BREEZY WIND,
TEENS TO LOWER 20S WIND CHILL VALUES WILL BE COMMON IN THE
AFTERNOON.
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/
KEY MESSAGES:
- NEAR-RECORD LOW TEMPERATURES THURSDAY MORNING.
- LOW CONFIDENCE IN SNOW FRIDAY.
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CLEARING WILL CONTINUE BEHIND THE COLD FRONT, WITH HIGH
PRESSURE ESTABLISHING OVERNIGHT THURSDAY. FOR AT LEAST THE
EARLY OVERNIGHT PERIOD, THE ENTIRE AREA IS LIKELY TO SEE VERY
EFFECTIVE RADIATIVE COOLING WITH CALM AND MOSTLY CLEAR
CONDITIONS WITH A SURFACE SNOWPACK. FOR THE LATTER HALF OF THE
OVERNIGHT PERIOD, THERE WILL BE SOME UNCERTAINTY TO THE
EFFICIENCY OF COOLING FOR REGIONS SOUTH OF PITTSBURGH, WITH
SOME EURO ENSEMBLES SHOWING CLOUDS APPROACHING, WHILE MOST
AMERICAN ENSEMBLES STAY CLEAR (AND COOLER). THIS COULD BE
RECORD BREAKING COLD FOR MANY AREA SITES (SEE CLIMATE SECTION).
MUCH OF THE TEMPERATURE VARIABILITY IS IN THE UPPER SINGLE
DIGITS TO LOW TEENS, WITH SHELTERED VALLEYS LIKELY THE COOLEST
LOCATIONS.
CLOUD COVER UNCERTAINTY IS TIED TO A LARGER UNCERTAINTY IN A LOW
TRACK FOR THE MORNING FRIDAY. SOME SOLUTIONS HAVE THE LOW
RECURVING SLIGHTLY ALONG THE COAST, PROVIDING SOME SNOW CHANCES,
PARTICULARLY SOUTHEAST OF PITTSBURGH, WHILE OTHERS HAVE THE
ZONAL FLOW PREVAILING, SHUNTING THE LOW OFFSHORE TO THE SOUTH.
ON THE HIGH END, AN ADVISORY (3" TO 6") MIGHT BE POSSIBLE FOR
THE WV HIGH TERRAIN, BUT ON THE LOW END, ALL AREAS COULD SEE
NOTHING.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
KEY MESSAGES:
- BELOW NORMAL TEMPERATURES CONTINUE EARLY NEXT WEEK.
- MORE WINTER WEATHER POTENTIAL.
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A WEAK REINFORCEMENT OF TROUGHING HAS INCREASED IN CONFIDENCE
SUNDAY INTO MONDAY MORNING, WHICH MAY ALLOW LOW CHANCES OF
ADDITIONAL SNOW SHOWERS, THOUGH CHANCES ARE LOW IN ANY
ACCUMULATIONS >1" (15% TO 30%), SHOULD THEY OCCUR AT ALL (40%
TO 70% CHANCE). THE HIGHEST CHANCES OF ANY ACCUMULATIONS WOULD
BE FOR THE PA/WV RIDGES, AND THE LOWEST WOULD BE IN EASTERN
OHIO.
MID-TO-LATE WEEK TEMPERATURE UNCERTAINTIES WOULD BE MORE TIED
TO AMPLITUDE UNCERTAINTY OF THE SEMI-PERSISTANT EASTERN TROUGH.
A STRONGER PREVAILING TROUGH WOULD ALLOW FOR COOLER CONDITIONS,
WITH HIGHER CHANCES OF LOW-QPF SNOWFALL. A WEAKER TROUGH WOULD
LIKELY CORRELATE TO WARMER CONDITIONS WITH HIGHER QPF POTENTIAL
IN MIXED PRECIPITATION EVENTS.
AVIATION /06Z THURSDAY THROUGH MONDAY/
KEY MESSAGES:
- MVFR CEILINGS TONIGHT WITH LIGHT SNOW RETURNING AFTER 09Z
- IFR CIGS EXPECTED/VIS POSSIBLE WITH HEAVIER SNOW SHOWERS
- MODELS MORE PESSIMISTIC ON CLEARING THURSDAY AFTERNOON
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THE COLD FRONT ITSELF IS JUST NOW BEGINNING TO CROSS LAKE ERIE.
LIGHT SNOW HAS BEGUN AT FKL BUT WITH SLOWER FRONTAL MOVEMENT,
KICKED BACK SNOW ONSET TIMES AT MOST PORTS. MVFR CIGS AREAWIDE
ARE EXPECTED TO SLOWLY DEGRADE DOWN TO AN IFR/MVFR MIX NEAR 1KFT
OVER THE COMING HOURS AS LIGHT SNOW SLOWLY BEGINS TO OVERSPREAD
THE REGION. ANY HEAVIER SNOW SHOWERS CAN BRING BRIEFLY REDUCED
VIS AND CIG, THIS HAS BEEN INCLUDED AS TEMPOS FOR MOST PORTS
SAVE FOR MGW WHICH MAY BE FAR ENOUGH SOUTH TO AVOID SNOWFALL.
SNOW IS EXPECTED TO TRAIL OFF BY MID MORNING AS WINDS PICK UP
BEHIND THE FRONT. MOST PORTS CAN SEE NWERLY GUSTS BETWEEN 15-20
KNOTS. MODELS HAVE GROWN SLIGHTLY MORE PESSIMISTIC ON A QUICK
CLEARING OF CIGS THIS AFTERNOON AND PROBABILITIES FOR MVFR CIGS
REMAINING AT 18Z ARE LARGELY NORTH OF 80% BESIDES AT ZZV. THESE
PROBABILITIES SLOWLY ERODE THIS EVENING BUT REMAIN BETWEEN
30-50% AT MANY PORTS THROUGH 00Z. FKL/DUJ ARE LIKELY TO HOLD
ONTO MVFR CIGS THE LONGEST.
OUTLOOK... VFR BEGINS TO BECOME THE RULE NOT THE EXCEPTION BY
EARLY FRIDAY MORNING AS HIGH PRESSURE BUILDS IN BEHIND THE
FRONT. RESTRICTIONS ARE POSSIBLE AGAIN SATURDAY AND SUNDAY WITH
A CROSSING COLD FRONT.
CLIMATE
AT LEAST FOUR OF OUR CLIMATE SITES HAVE A CHANCE TO CHALLENGE
RECORD LOW TEMPERATURES FOR DECEMBER 5 ON FRIDAY MORNING. TWO
OTHER SITES ARE LESS LIKELY TO APPROACH THEIR RECORD LOWS.
CURRENT 12/5 FORECAST
SITE RECORD LOW LOW
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PITT INTL 12 (1976) 9
MORGANTOWN 11 (1974) 11
DUBOIS 10 (1991) 6
WHEELING 12 (1944) 10
ZANESVILLE 3 (1957) 9
NEW PHILADELPHIA 2 (1966) 7
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...CL
NEAR TERM...FRAZIER
SHORT TERM...MILCAREK
LONG TERM...MILCAREK
AVIATION...AK
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