235  
FXUS61 KCTP 221737  
AFDCTP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE STATE COLLEGE PA  
1237 PM EST WED JAN 22 2025  
   
SYNOPSIS
 
 
A RIDGE OF HIGH PRESSURE EXTENDING ALONG THE ENTIRE LENGTH OF  
THE APPALACHIANS WILL BRING THE COLDEST TEMPERATURES OF THIS  
CURRENT ARCTIC OUTBREAK ACROSS THE REGION THIS MORNING. THIS  
RIDGE WILL DRIFT EAST AND OFF THE MID ATLANTIC COAST TONIGHT  
INTO THURSDAY. UPPER LEVEL TROUGHING WILL REMAIN OVER THE AREA  
INTO EARLY NEXT WEEK WITH A SERIES OF WEAK SHORTWAVES PASSING  
THROUGH WITH JUST SOME FLURRIES OR A FEW BRIEF SNOW SHOWERS.  
 

 
   
NEAR TERM /THROUGH TONIGHT/
 
 
CLEAR SKIES ARE CURRENTLY OBSERVED ON RECENT SATELLITE IMAGERY  
UNDER THE INFLUENCE OF SURFACE HIGH PRESSURE, ALLOWING FOR  
TEMPERATURES TO INCREASE QUICKLY ACROSS THE FORECAST AREA, WITH  
THIS TREND CONTINUING FOR THE NEXT COUPLE OF HOURS AS KBFD HAS  
INCREASED FROM -17F AT 0753AM EST TO -3F AT 0930AM EST. THIS  
SURFACE HIGH PRESSURE HAS ALSO BROUGHT A DECREASING TREND IN  
WINDS, WHICH HAS LOWERED THE WIND CHILL THREAT FOR MUCH OF THE  
AREA. COLD WIND CHILLS ARE STILL EXPECTED TO CONTINUE THROUGH  
NOON, ESPECIALLY FOR AREAS UNDER THE EXTREME COLD WARNING  
(SOMERSET/CAMBRIA COUNTIES); HOWEVER, EXPECT THESE CONCERNS TO  
CONTINUE TO WANE WITH CURRENT HEADLINES EXPECTED TO EXPIRE  
CLOSER TO THE 12PM TIMEFRAME.  
 
WARMING LATER THIS AFTERNOON WILL BE (SLIGHTLY) HINDERED BY AN  
APPROACHING DECK OF MID-LEVEL CLOUDS CURRENTLY STATIONED ALONG  
A LINE GENERALLY EXTENDING NORTH-TO-SOUTH OVER COLUMBUS, OH AND  
FURTHER SOUTH INTO NORTHERN KENTUCKY. THIS SLIGHT OBSCURATION  
FROM PEAK- HEATING WILL ALLOW FOR MAXTS TO TOP OUT NEAR 10  
DEGREES ACROSS THE COLDEST POCKETS OF NORTHERN PENNSYLVANIA TO  
NEAR 18-19 DEGREES IN THE LOWER SUSQUEHANNA VALLEY.  
 
THE BULK OF MODEL GUIDANCE CONTINUES TO INDICATE SOUTHERLY FLOW  
ALONG WITH A MID-LEVEL CLOUD DECK, THAT WILL LIMIT POTENTIAL  
FOR DANGEROUSLY COLD WIND CHILLS AT THIS TIME, WITH MINIMUM WIND  
CHILLS STATIONED ACROSS THE VALLEYS OF NORTHERN PENNSYLVANIA  
ALONG WITH THE LAUREL HIGHLANDS. CRITERIA, COUPLED WITH THE  
CURRENT FORECAST, SUGGEST THAT ANY HEADLINES WOULD BE CONFINED  
TO THE LAUREL HIGHLANDS; HOWEVER, LOWER CONFIDENCE ON ANY  
PRODUCT ISSUANCE AT THIS TIME GIVEN LOWEST WIND CHILLS ARE  
CONFINED TO THE HIGHER ELEVATIONS OF SOMERSET/CAMBRIA COUNTIES  
WITH WIND CHILLS STAYING NEAR-OR-ABOVE 0F FOR MUCH OF THE  
COUNTY.  
 

 
   
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/
 
 
MARKEDLY LESS COLD CONDITIONS ARE ANTICIPATED THURSDAY, AS A  
SOUTHWEST FLOW DEVELOPS BETWEEN HIGH PRESSURE OFF OF THE EAST  
COAST AND AN UPSTREAM COLD FRONT OVER THE GRT LKS. SEE NO REASON  
TO DEVIATE FROM NBM MAX TEMPS, WHICH ARE IN THE 20S. RH  
TIMESECTIONS SUPPORT CLOUDS ARRIVING FROM WEST TO EAST DURING  
THE AFTERNOON AHEAD OF THE APPROACHING COLD FRONT. MODEL  
SOUNDINGS INDICATE THE RETURN MOISTURE AHEAD OF THE FRONT WILL  
BE SHALLOW, BUT COULD SUPPORT SOME OCCASIONAL LIGHT SNOW WHERE  
THE SSW FLOW IS FORCED TO ASCEND THE NW MTNS LATE IN THE DAY  
THROUGH MUCH OF FRIDAY.  
 
IN FACT, THE CLOUD LAYER (INITIALLY UP TO 7-8 KFT AGL THURSDAY  
AFTERNOON AND EVENING THEN ONLY UP TO 3-4 KFT AGL ON FRIDAY)  
WILL BE OCCUPIED BY THE ENTIRE DGZ. PERFECT CONDITIONS FOR THE  
OROGRAPHIC LIGHT SNOW. INCLUDED A 36 HOUR SNOW TOTAL GRID (12Z  
THURSDAY THROUGH 00Z SAT) TO CAPTURE THE BULK OF THIS MINOR  
WINTER PRECIP EVENT OVER THE WESTERN MTNS.  
 
OUTSIDE OF THIS MINOR SNOWFALL, EXPECT MAINLY DRY AND COLD  
CONDITIONS INTO THE WEEKEND. TOWARDS THE END OF THIS WEEK A WEAK  
UPPER LEVEL SHORT WAVE WILL SWING OFF THE GREAT LAKES. A  
SURFACE TROUGH WILL ARRIVE BY FRIDAY MORNING, BRINGING WITH IT  
ANOTHER MOISTURE STARVED COLD FRONT. DESPITE THE SYNOPTIC  
FORCING THERE WILL NOT BE ENOUGH MOISTURE TO ALLOW FOR MUCH  
PRECIPITATION. EVEN WIND FLOW WILL REMAIN MOSTLY WESTERLY BEHIND  
THIS FRONT MAKING LAKE EFFECT SNOW IN THE NORTHWEST UNLIKELY AT  
THE BEGINNING OF THE EXTENDED PERIOD. STILL ENOUGH OF A CHANCE  
TO ENTER SLIGHT CHANCE POPS ACROSS THE HIGHER TERRAIN.  
 

 
   
LONG TERM /SATURDAY THROUGH TUESDAY/
 
 
LARGE SCALE FLOW PATTERN SUPPORTS CLIPPERS DROPPING SOUTHEAST  
ACROSS THE GREAT LAKES NEXT WEEK. THE WARM WATERS OF THE GREAT  
LAKES WILL LIKELY RESULT IN HIGH CENTERS SPLITTING INTO TWO  
SECTIONS, WITH THE COLDEST AIR STAYING NORTH OF THE LAKES. THUS  
WE WILL SEE TEMPERATURES CLOSER TO NORMAL. WITH THE OVERALL  
PATTERN AND SNOW COVER, WILL BE HARD TO SEE ANY EXTENDED MILD  
SNAPS.  
 
UPPER LEVET TROUGHS AND WIND SHIFT LINES WILL SUPPORT SOME SNOW  
SHOWERS FROM TIME TO TIME INTO LATE SUNDAY, MAINLY ACROSS THE  
FAR NORTHWEST.  
 
A CLIPPER DROPPING SOUTHEAST BY MID WEEK MAY SUPPORT MORE SNOW  
A BIT FURTHER EAST AND SOUTH.  
 

 
   
AVIATION /18Z WEDNESDAY THROUGH MONDAY/
 
 
HIGH CONFIDENCE IN WIDESPREAD VFR FLYING THROUGH THE 22/12Z TAF  
PERIOD.  
 
OUTLOOK...  
 
THU...VFR THEN MVFR/IFR POSSIBLE THURSDAY NIGHT WITH -SHSN IN  
NORTHERN AND WESTERN PA.  
 
FRI...MVFR/IFR CONDITIONS POSSIBLE WITH -SHSN IN NORTHERN &  
WESTERN PA MAINLY DURING THE DAY.  
 
SAT...VFR/NO SIG WX.  
 
SUN...MVFR IN -SHSN POSSIBLE IN NORTHERN & WESTERN PA.  
 

 
   
CLIMATE
 
 
RECORD LOW MAXIMUM TEMPERATURES FOR JANUARY 22:  
 
HARRISBURG 14F IN 2014  
WILLIAMSPORT 14F IN 1961  
ALTOONA 10F IN 2014  
BRADFORD 6F IN 2014  
STATE COLLEGE 7F IN 1936  
 

 
   
CTP WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  
 

 
 

 
 
SYNOPSIS...LAMBERT/FITZGERALD  
NEAR TERM...NPB  
SHORT TERM...GUSEMAN/LAMBERT/FITZGERALD  
LONG TERM...MARTIN  
AVIATION...STEINBUGL  
CLIMATE...STEINBUGL  
 
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