148
FXUS61 KPBZ 172335
AFDPBZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
635 PM EST MON FEB 17 2025
SYNOPSIS
WIND CHILLS BETWEEN 5 AND 20 BELOW ARE EXPECTED TONIGHT. BELOW
AVERAGE TEMPERATURES CONTINUE THIS WEEK WITH ADDITIONAL SNOW
POTENTIAL WEDNESDAY INTO THURSDAY. A WARM UP IS FAVORED BY THE
WEEKEND.
NEAR TERM /THROUGH TUESDAY/
KEY MESSAGES:
- WIND CHILLS OF -5 TO -20 OVERNIGHT; A COLD WEATHER ADVISORY IS
IN EFFECT FOR PORTIONS OF THE AREA.
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EVENING UPDATE...ONLY COSMETIC CHANGES FOR THE OVERNIGHT PERIOD.
REFRESHED THE LOWS AND WIND CHILLS. REST OF THE FORECAST IS IN
GOOD SHAPE.
PREVIOUS DISCUSSION...
INTO TONIGHT, WINDS ARE EXPECTED TO RELAX WITH THE STRONGEST
WINDS ABOVE THE MIXED LAYER, BUT 15MPH TO 25MPH STILL SEEMS
REASONABLE. COMBINED WITH THE COLD TEMPERATURES, THIS WILL
GENERATE WIND CHILL HAZARDS. A COLD WEATHER ADVISORY HAS BEEN
HOISTED ACCORDINGLY IN AREAS WITH A >50% CHANCE OF -10F "FEELS-
LIKE" VALUES OR BELOW. MERCER AND VENANGO WERE LEFT OUT DUE TO
THEIR LOWER (-15F) CRITERIA AND SINCE THE COLDEST AIR IS MORE TO
THE EAST. LOWS ARE FORECAST IN THE SINGLE DIGITS FOR MOST.
SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/
KEY MESSAGES:
- DRY AND COLD TUESDAY THROUGH WEDNESDAY.
- THE LOW PRESSURE SYSTEM WEDNESDAY HAS SHIFTED FURTHER SOUTH.
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TUESDAY APPEARS TO BE LIKELY THE COLDEST DAY OF THE WEEK, WITH
A ROUGHLY >50% CHANCE OF A MAX TEMPERATURE BELOW 20F NORTH OF
I-70. FOR REFERENCE, THIS IS NEARLY 20F BELOW NORMAL FOR THIS
TIME OF YEAR. ZONAL FLOW UNDER A STRONG UPPER JET SHOULD KEEP
PRECIPITATION CHANCES >10%.
TUESDAY NIGHT, LOWS RETURN TO THE LOW 10S AND SINGLE DIGITS, BUT
WIND IS MUCH LESS LIKELY SURFACE HIGH PRESSURE OVERHEAD. THIS
WOULD KEEP WIND CHILL CONCERNS A BIT LOWER THAN THE NIGHT PRIOR,
BUT THERE IS STILL ROUGHLY A 20% CHANCE OF HITTING COLD WEATHER
ADVISORY CRITERIA FOR PARTS OF THE I-80 CORRIDOR AND THE HIGH
TERRAIN.
THE LOW PRESSURE SYSTEM SET TO IMPACT THE REGION ON WEDNESDAY
HAS SHIFTED A BIT FURTHER SOUTH THAN THE PREVIOUS RUN OF THE
ENSEMBLES. NBM PROBS NOW FOR EVEN AN INCH IN THE VERY SOUTHERN
AREAS ARE LESS THAN 20%. WILL KEEP THE POTENTIAL FOR SNOW IN THE
SOUTHERN COUNTIES BUT SHOULD BE LESS IMPACTFUL.
LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/
KEY MESSAGES:
- POTENTIAL LAKE EFFECT/ENHANCED SNOW WEDNESDAY NIGHT AND
THURSDAY.
- HIGHER CHANCES OF DRY WEATHER AND "WARMING" TEMPERATURES INTO
THE WEEKEND.
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WITH THE PARENT LOW TRACK TO THE SOUTH, THERE REMAINS AN
UNCERTAINTY OF WHETHER THE LOW PIVOTS AND TRACKS UP THE COAST.
IF THIS DOES OCCUR, THERE STANDS TO BE POTENTIALLY ADVISORY
LEVEL SNOWS FOR WEDNESDAY NIGHT THROUGH THURSDAY ON THE BACK END
OF THE LOW WITH ADDITIONAL SUPPORT FROM THE LAKE. IT MAY VERY
WELL STAND THAT THE LOW TRACK TAKES THE LOW STRAIGHT OFF THE
COAST AND OUT TO SEA. THIS LEAVES THE POTENTIAL SOLELY ON THE
LAKE EFFECT SNOW. HAVE OPTED WITH THE LAKE SNOW AT THIS TIME
BUT THIS ONLY GIVES A 15% TO 30% CHANCE OF AN INCH IN THE
RIDGES. HAVE NOT INCLUDED THIS POTENTIAL IN THE HWO BUT WILL
DEFINITELY NEED MONITORING.
THE MAIN IMPACTS THIS WEEK APPEAR TO LIKELY BE THE CONTINUED
COLD, WITH TEMPERATURES REMAINING IN THE BALLPARK OF 15F TO 20F
BELOW NORMAL FROM LATE MONDAY INTO EARLY THURSDAY. THE IS HIGH
CONFIDENCE IN RIDGING INTO THE WEEKEND, BUT THE MAIN
UNCERTAINTY IS HOW STRONG EMBEDDED TROUGHING MAY BE, WHICH WILL
CORRELATE TO JUST HOW "WARM" THINGS GET. WE DON'T HAVE A >50%
CHANCE OF BREAKING NORMAL UNTIL MONDAY WHERE THE HIGHS CROSS
INTO THE 40S AHEAD OF ANOTHER SHORTWAVE TROUGH.
AVIATION /00Z TUESDAY THROUGH SATURDAY/
A PEEK AT THE 00Z PIT SOUNDING SHOWS FAR MORE DRY AIR THAN HIGH-RES
MODELS WOULD SUGGEST. THIS GOES HAND IN HAND WITH THE SWEEPING
RETURN OF VFR ACROSS THE REGION.
OVERNIGHT VFR IS EXPECTED TO BE RATHER PREVALENT AS MID CLOUDS
FILTER IN FROM THE WEST. THE POSSIBLE EXCEPTIONS TO THIS ARE FKL/DUJ
WHICH SHOW HINTS OF AN MVFR PERIOD OVERNIGHT. FOR NOW THE TAFS
REFLECT THIS BUT IF THE DRY AIR CONTINUES TO WIN OUT AND THE MODELS
REMAIN FOOLED BY THIS THEN EVEN THIS MVFR WILL BE AXED.
GUSTS RELAX SOME OVERNIGHT BUT CAN RETURN TOMORROW AFTERNOON AS BKN
CU SPROUTS ACROSS THE REGION. IT REMAINS LOW CONFIDENCE AT THE EXACT
HEIGHT THIS FIELD WILL ESTABLISH ITSELF BUT IT REMAINS LIKELY IT IS
NEAR THE VFR/MVFR BORDER.
OUTLOOK...
BY WEDNESDAY, REGION-WIDE RESTRICTIONS ARE EXPECTED TO RETURN
AS ANOTHER STORM IMPACTS THE REGION. THE BEST CHANCE FOR SNOW
WILL FALL SOUTH OF THE MASON-DIXON LINE AND RECENT TRENDS
CONTINUE TO SHIFT FARTHER AND FARTHER SOUTH. DRIER WEATHER IS
THEN FAVORED TO RETURN TO CLOSE OUT THE WEEK.
PBZ WATCHES/WARNINGS/ADVISORIES
PA...COLD WEATHER ADVISORY FROM 10 PM THIS EVENING TO 10 AM EST
TUESDAY FOR PAZ009-014>016-022-074-076>078.
OH...NONE.
WV...COLD WEATHER ADVISORY FROM 10 PM THIS EVENING TO 10 AM EST
TUESDAY FOR WVZ512-514.
SYNOPSIS...22/SHALLENBERGER
NEAR TERM...22/SHALLENBERGER
SHORT TERM...SHALLENBERGER
LONG TERM...SHALLENBERGER
AVIATION...MLB/AK
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