774
FXUS61 KCTP 172035
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
335 PM EST SAT JAN 17 2026
WHAT HAS CHANGED
* UPDATED TIMING FOR SNOW SQUALLS THIS AFTERNOON AND EVENING.
* INCREASED SNOWFALL TOTALS OVER THE LOWER SUSQUEHANNA VALLEY
FOR TONIGHT AND TOMORROW.
KEY MESSAGES
1) SNOW SQUALLS MOVE ACROSS NORTHWEST PA THIS AFTERNOON,
CREATING HAZARDOUS TRAVEL CONDITIONS.
2) LIGHT SNOW ACROSS SOUTHEAST PA TONIGHT AND TOMORROW AS LOW
PRESSURE DEVELOPS OFF THE EAST COAST.
3) AN ARCTIC BLAST MONDAY WILL PRODUCE LITTLE SNOWFALL BUT LEAD
TO DANGEROUS, SUB-ZERO WIND CHILLS MONDAY NIGHT AND TUESDAY.
4) COLDER THAN NORMAL TEMPERATURES CONTINUE THROUGH THE END OF
THE MONTH WITH STORM CHANCES (LIGHT TO MODERATE SNOWFALL) EVERY
FEW DAYS.
DISCUSSION
KEY MESSAGE 1: SNOW SQUALLS MOVE ACROSS NORTHWEST PA THIS AFTERNOON,
CREATING HAZARDOUS TRAVEL CONDITIONS.
LIGHT SNOW ACROSS THE LOWER SUSQUEHANNA VALLEY HAS MOVED OFF TO
THE EAST AND OUR CONCERN HAS SHIFTED TO THE LINE OF SNOW SQUALLS
THAT HAS DEVELOPED ALONG A COLD FRONT MOVING INTO NORTHWEST PA
AS OF 2 PM. SOME BREAKS IN THE CLOUD COVER HAS ALLOWED FOR WEAK
INSTABILITY TO DEVELOP WHICH SHOULD HELP TO MAINTAIN THESE
SQUALLS AS THEY MOVE FARTHER INTO PENNSYLVANIA THROUGH THE REST
OF THE AFTERNOON. THE SUNSHINE HAS ALSO HELPED TO WARM ROAD
SURFACE TEMPERATURES INTO THE UPPER 30S AND LOW 40S, SO IN
ADDITION TO RAPIDLY REDUCED VISIBILITY, THERE WILL BE THE
POTENTIAL FOR FLASH FREEZE CONDITIONS AS THE SQUALLS MOVE
THROUGH.
MOST GUIDANCE SUGGESTS THAT THE GREATEST SNOW SQUALL THREAT WILL
REMAIN NORTH OF INTERSTATE 80, BUT THIS WILL NEED TO BE
MONITORED OVER THE NEXT COUPLE OF HOURS. EXPECT THE SQUALLS TO
WEAKEN LATER THIS EVENING WITH THE LOSS OF DAYTIME HEATING.
KEY MESSAGE 2: LIGHT SNOW ACROSS SOUTHEAST PA TONIGHT AND
TOMORROW AS LOW PRESSURE DEVELOPS OFF THE EAST COAST.
THE 12Z MODEL SUITE HAS CONTINUED TO TREND TOWARDS A MORE
AMPLIFIED SYSTEM MOVING THROUGH THE NORTHEASTERN US TONIGHT AND
TOMORROW. VERY LIGHT SNOW WILL INITIALLY DEVELOP IN THE TYPICAL
UPSLOPE REGIONS OF CAMBRIA AND SOMERSET COUNTIES AFTER MIDNIGHT
AS THE UPPER TROUGH ARRIVES BEFORE ENERGY TRANSFERS TO A
DEVELOPING AREA OF LOW PRESSURE OFF OF THE EAST COAST. THIS
SYSTEM WILL BRING LIGHT SNOW TO THE LOWER SUSQUEHANNA VALLEY
TONIGHT AND TOMORROW, WITH PORTIONS OF YORK AND LANCASTER COUNTY
LIKELY SEEING UP TO 3 INCHES OF SNOW. WE WILL LIKELY BE ISSUING
A WINTER WEATHER ADVISORY FOR PORTIONS OF SOUTHEAST PA TO
HIGHLIGHT THIS POTENTIAL.
KEY MESSAGE 3: AN ARCTIC BLAST MONDAY WILL PRODUCE LITTLE
SNOWFALL BUT LEAD TO DANGEROUS, SUB-ZERO WIND CHILLS MONDAY
NIGHT AND TUESDAY.
A COLD FRONT TRACKS THROUGH CENTRAL PA ON MONDAY. THOUGH
MOISTURE WILL BE LIMITED WITH THE FRONT, THERE MAY BE SOME LIGHT
SNOW THAT ACCOMPANIES IT. IN ITS WAKE, SURFACE AND STEERING
WINDS OUT OF THE SOUTHWEST OR WEST- SOUTHWEST SHOULD KEEP LAKE
EFFECT SNOW BANDS DIRECTED INTO NEW YORK WITH MAINLY DRY
CONDITIONS IN PENNSYLVANIA. MIN WIND CHILLS MONDAY NIGHT/TUESDAY
MORNING RANGE FROM 0F IN THE LSV TO MINUS 20F OVER PORTIONS OF
THE ALLEGHENIES. THE CURRENT FORECAST WOULD SUPPORT A COLD
WEATHER ADVISORY IN THE LAURELS AND NORTHERN MOUNTAINS
(APPROXIMATELY ALONG, WEST, AND NORTH OF THE I-99/I-80 CORRIDOR)
AND POSSIBLY AN EXTREME COLD WARNING IN THE LAUREL HIGHLANDS.
FORECAST HIGHS IN THE + SINGLE DIGITS TO ~20F ON TUESDAY ARE 15
TO 25 DEGREES BELOW THE HISTORICAL AVERAGE, THOUGH NOT QUITE
RECORD SETTING. WIND CHILLS LIKELY STAY BELOW ZERO WEST OF I-99
AND NORTH OF I-80 THROUGH WEDNESDAY MORNING. LOW- LEVEL FLOW
BECOMES MORE WESTERLY BY WEDNESDAY, WHICH WILL HELP TO DIRECT
LAKE EFFECT SNOW BANDS BACK INTO NORTHWEST PA.
KEY MESSAGE 4: COLDER THAN NORMAL TEMPERATURES CONTINUE THROUGH
THE END OF THE MONTH WITH STORM CHANCES (LIGHT TO MODERATE
SNOWFALL) EVERY FEW DAYS.
A PERSISTENT WEST COAST RIDGE AND EAST COAST TROUGH PATTERN IN
THE UPPER LEVELS WILL ENSURE THE CONTINUATION OF BELOW NORMAL
TEMPERATURES THROUGH THE END OF JANUARY. PERIODIC WAVES OF LOW
PRESSURE TRAVERSING THE HIGH PLAINS AND GREAT LAKES MEAN WE'LL
SEE FREQUENT OPPORTUNITIES FOR PRECIPITATION. MOST OF THE STORM
SYSTEMS APPEAR WEAK AND RELATIVELY DISORGANIZED AT THIS POINT,
WHICH WOULD FAVOR THE HIGHEST SNOWFALL TOTALS OCCURRING IN THE
TYPICAL UPSLOPE AND LAKE EFFECT SNOW REGIONS OF THE LAURELS AND
NORTHWEST MOUNTAINS THROUGH THE END OF JANUARY.
AVIATION /20Z SATURDAY THROUGH THURSDAY/
SEVERAL WAVES OF SNOW SHOWERS AND A LINE OF HEAVIER SQUALLS WILL
MOVE ACROSS THE NORTHWEST HALF OF CENTRAL PA, DYING OFF THIS
EVENING. THE WORST CONDITIONS WILL BE AT BFD AND PERHAPS FIG.
THOSE LOCATIONS MAY DROP TO NEAR ZERO VISIBILITY (VLIFR) WHILE
THE WIND GUSTS INTO THE 30S AS THE SQUALL PASSES. SOME SPECKLES
OF IFR WILL BE FOUND ELSEWHERE NEAR AND AT UNV AND IPT THROUGH
SUNSET, BUT THOSE TERMINALS WOULD ONLY HAVE VERY BRIEF DIPS TO
IFR (10-20MINS). THESE SHOW SHOWERS AND SQUALLS WILL FALL APART
AND WEAKEN EARLY THIS EVENING. A BRIEF LULL IN SNOWFALL WILL END
AROUND MIDNIGHT IN SOMERSET COUNTY AND BY 3 OR 4 AM IN
ADAMS/YORK/LANCASTER. THAT LIGHT SNOW WILL BECOME MORE HEAVY
THROUGH SUNRISE, ESPECIALLY IN YORK AND LANCASTER. THE HEAVIER
SNOW AND LIFR CONDITIONS WILL BE MAINLY S OF MDT AND MUI. THESE
AREA WILL LIKELY (90%) SEE LIFR FOR 3-6HRS. THE SNOW AND LOW
CIGS/VISBY WILL LIFT TO MVFR OR BETTER IN THE EARLY AFTN. THE
WINDS WILL BECOME LESS GUSTY OVER THE W EARLY TONIGHT. THE LIGHT
WIND IN THE EAST WILL BE LIGHT.
OUTLOOK...
MON...COLD FROPA. WEST WINDS GUSTING OVER 30KTS. RESTRICTIONS
LIKELY WITH SNOW SHOWERS ESPECIALLY WEST.
TUE-THU...LIGHT SNOW/IFR POSSIBLE IN THE NW AT TIMES.
CTP WATCHES/WARNINGS/ADVISORIES
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
PAZ004>006-010-011-017.
WINTER WEATHER ADVISORY FROM 3 AM TO 3 PM EST SUNDAY FOR
PAZ065-066.
WHAT HAS CHANGED...BAUCO
KEY MESSAGES...BANGHOFF/BAUCO
DISCUSSION...BANGHOFF/BAUCO
AVIATION...DANGELO/COLBERT
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