451
FXUS61 KPBZ 220540
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
1240 AM EST MON DEC 22 2025
SYNOPSIS
DRY CONDITIONS TONIGHT. RAIN CHANCES, MIXED WITH A WINTRY MIX,
ARE EXPECTED LATE MONDAY INTO EARLY TUESDAY. WARM PATTERN
EXPECTED LATE THIS WEEK.
NEAR TERM /UNTIL 6 AM THIS MORNING/
KEY MESSAGES:
- COLD TEMPERATURES TONIGHT
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TONIGHT'S MINIMUM TEMPERATURES HAVE BEEN ADJUSTED DOWNWARD DUE TO
OPTIMAL RADIATIONAL COOLING CONDITIONS (CLEAR SKIES AND LIGHT/CALM
WINDS). OVERNIGHT LOWS WILL FALL INTO THE TEENS/LOW-20S.
SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/
KEY MESSAGES:
- WARMER CONDITIONS MONDAY; POTENTIAL FOR SNOW NORTH OF
PITTSBURGH IN THE AFTERNOON/EVENING
- RAIN AND WINTRY MIX EXPECTED MONDAY NIGHT INTO TUESDAY WITH
LARGE SCALE DISTURBANCE
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HIGH PRESSURE OVER CENTRAL WEST VIRGINIA WILL MAINTAIN COLD,
CALM CONDITIONS BEFORE DAWN MONDAY. BY MID-MORNING, SOUTHERLY
FLOW WILL STRENGTHEN IN RESPONSE TO A DISTURBANCE TRACKING
EASTWARD FROM THE NORTHERN PLAINS/MIDWEST.
A TRACKING SHORTWAVE OVER THE GREAT LAKES MAY TRIGGER LIGHT SNOW
NORTH OF PITTSBURGH DURING THE LATE AFTERNOON HOURS ON MONDAY.
PRECIPITATION IS EXPECTED TO DIMINISH RAPIDLY BETWEEN 19Z AND
21Z (7-9PM) AS THE SHORTWAVE SHIFTS TOWARD NORTHERN NEW YORK.
THE LEADING EDGE OF A NEW SYSTEM ARRIVES AFTER MIDNIGHT TUESDAY,
BRINGING A MESSY MIX OF WINTRY WEATHER. COLD AIR TRAPPED IN THE
LOW TO MID-LEVELS WILL LIKELY CAUSE SNOW TO TRANSITION THROUGH
SLEET AND FREEZING RAIN BEFORE FINALLY TURNING TO ALL RAIN.
AREAS NORTHEAST OF PITTSBURGH ARE AT A RISK FOR ICY ROADS, AND A
WINTER WEATHER ADVISORY MAY BE ISSUED IN THE NEXT 24 TO 36
HOURS. BY 7AM TUESDAY, CONFIDENCE INCREASES THAT RISING
TEMPERATURES AND DEW POINTS WILL TURN PRECIPITATION INTO A
LIGHT STEADY RAIN.
DRIER AIR WILL BEGIN PUSHING IN FROM THE WEST TUESDAY
AFTERNOON. A FEW ISOLATED SHOWERS MIGHT STICK AROUND EAST OF
PITTSBURGH THROUGH DUSK, THE CLOUDS WILL LIKELY LINGER INTO THE
OVERNIGHT TIME PERIOD DUE TO MOISTURE TRAPPED NEAR THE SURFACE.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
KEY MESSAGES:
KEY MESSAGES:
- A COUPLE DISTURBANCES BRING RAIN AROUND CHRISTMAS.
- HIGHER CHANCES OF THUNDER THAN SNOW ON CHRISTMAS.
- HIGH TEMPERATURE UNCERTAINTY SATURDAY AND BEYOND.
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THERE IS CONTINUED HIGH CONFIDENCE IN A RIDGE IN PLACE FOR MUCH OF
MID-TO-LATE WEEK. ON CHRISTMAS EVE, THE MAIN UNCERTAINTY IN
TEMPERATURES WILL BE THE DEGREE OF TROUGHING IN THE CANADIAN
MARITIMES. IF THE TROUGH IS STRONGER, HIGHS COULD BE AS LOW AS THE
UPPER 30S TO LOW 40S, THOUGH IF THE TROUGHING IS WEAKER,
TEMPERATURES COULD BE AS HIGH AS THE UPPER 40S TO LOW 50S.
OVERNIGHT ON CHRISTMAS EVE, A SHORTWAVE DISTURBANCE IS EXPECTED TO
ROUND THE TOP OF THE RIDGE AXIS WITH HIGH CONFIDENCE IN OCCURRENCE
AND MEDIUM CONFIDENCE IN TIMING. MOST ARES ARE EXPECTED TO SEE LESS
THAN 0.25" OR RAIN, WHEREAS 0.5" WOULD BE THE WETTEST POSSIBLE
SCENARIO NOR NOW. CONSEQUENTLY, WITH THE POTENTIAL FOR SOME ELEVATED
INSTABILITY, THIS ALSO MEANS IT'LL BE MORE LIKELY THE AREA SEES A
THUNDERSTORM OF CHRISTMAS (20%), THAN A WHITE CHRISTMAS (0%).
TEMPERATURE UNCERTAINTY ON CHRISTMAS REMAINS TIED TO THE AMPLITUDE
OF THE DOWNSTREAM EASTERN TROUGH, BUT MOST ENSEMBLES AGREE
TEMPERATURES WILL BE 10-15 DEGREES WARMER THAN CHRISTMAS EVE. THOUGH
WARM, IT WILL NOT BE THE WARMEST CHRISTMAS ON RECORD (67F FROM
1895).
ANOTHER WEATHER SYSTEM IS EXPECTED TO APPROACH ON CHRISTMAS NIGHT
FROM THE NORTHWEST, WHICH WILL LIKELY PRODUCE MORE PRECIPITATION.
MOST ENSEMBLES SHOW AN ADDITION 0.1" TO 0.25" OF RAIN, BUT A FEW
OUTLIERS HAVE UP TO 1" IN THE WETTEST SCENARIO DEPENDING ON LOW
TRACK.
INTO THE FRIDAY AND SATURDAY UNCERTAINTY CONTINUES TO AMPLIFY WITH
UNCERTAINTY IN THE PERSISTENCE AND AMPLIFICATION OF THE EASTERN
TROUGH, OR ITS VERY EXISTENCE ALTOGETHER. NONETHELESS, FRIDAY IS
LIKELY TO BE THE WARMEST DAY OF THE WEEK BEFORE A GENERAL TENDENCY
TO COOL DOWN. THE RATE AT WHICH THIS RIDGE BREAKS DOWN IS UNCERTAIN
THROUGH, WITH AN EVENTUAL COLD FRONTAL PASSAGE EXPECTED SOMEWHERE IN
THE LATE FRIDAY TO EARLY SUNDAY WINDOW. AFTERWARD, A GENERAL COOLING
TREND IS MOST FAVORED INTO NEXT MONDAY.
AVIATION /06Z MONDAY THROUGH FRIDAY/
KEY MESSAGES:
- VFR CONDITIONS AND LIGHT WINDS TONIGHT THROUGH 00Z TUESDAY
- RESTRICTIONS RETURN AFTER 063Z TUESDAY WITH PASSING LOW
PRESSURE; WINTRY MIX (ALONG/NORTH OF I-80) AND RAIN EXPECTED
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THERE WILL BE HIGH CONFIDENCE THAT VFR CONDITIONS WILL BE IN
PLACE THROUGH MUCH OF THE TAF PERIOD WITH LIGHT AND VARIABLE
WINDS. HIGH PRESSURE WILL KEEP MAINLY CLEAR SKIES AND DRY
CONDITIONS AT LEAST THROUGH 00Z TUESDAY. AN APPROACHING WARM
FRONT WILL BRING SOME LIGHT RAIN INTO THE AREA BY THE 00Z TO 06Z
TIMEFRAME TO THE TAF SITES. SOME MVFR CIGS WILL LIKELY SET IN
DURING THIS TIME. HAVE USED PROB30S TO COVER THIS APPROACH OF
MOISTURE GIVEN THE DRY SURFACE LAYER AND TIME FOR THE COLUMN OF
AIR TO SATURATE. A WINTRY MIX IS ALSO POSSIBLE DURING THIS TIME
AT THE FKL AND DUJ SITES.
OUTLOOK...
VFR MAY RETURN BRIEFLY DURING THE DAY WEDNESDAY
BEFORE ANOTHER SYSTEM BRINGS PRECIPITATION AND RESTRICTION
CHANCES BACK TO THE REGION WEDNESDAY NIGHT INTO THURSDAY.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...NONE.
OH...NONE.
WV...NONE.
SYNOPSIS...HEFFERAN
NEAR TERM...HEFFERAN/LUPO
SHORT TERM...FRAZIER
LONG TERM...FRAZIER
AVIATION...SHALLENBERGER
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