244  
FXUS61 KCTP 172355  
AFDCTP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE STATE COLLEGE PA  
655 PM EST SUN NOV 17 2024  
   
SYNOPSIS  
 
* DRY STRETCH CONTINUES INTO TUESDAY FOR MOST OF THE AREA WITH  
MILD TEMPERATURES AND LIGHT WINDS.  
* A SHORTWAVE WILL BRING LIGHT SHOWERS TO NORTHERN PA LATE  
TONIGHT AND THEN MORE RAIN IS POSSIBLE MAINLY IN WESTERN PA  
TUESDAY AFTERNOON INTO WEDNESDAY.  
* MORE WIDESPREAD PRECIPITATION AND MUCH COOLER TEMPERATURES  
ARRIVE WEDNESDAY NIGHT INTO THURSDAY AS AN DEEP UPPER LOW  
PASSES OVERHEAD AND BRINGS GUSTY WINDS AS WELL AS THE FIRST  
ACCUMULATING SNOW OF THE SEASON FOR PARTS OF THE AREA.  
 
 
   
NEAR TERM /THROUGH MONDAY/  
 
PATCHY VALLEY FOG AND SOME LOW CLOUDS HAVE MIXED OUT AT MIDDAY  
WITH TEMPERATURES IN THE 40S AREAWIDE. MILDER AIR STREAMING  
EAST AT MID AND UPPER LEVELS OF THE ATMOSPHERE CONTINUES TO ADVECT  
AN EXTENSIVE SHIELD OF CIRRUS TODAY. THE CIRRUS WILL BE THICK  
ENOUGH TO DIM OR EVEN BLOCK THE LOW ANGLE SUN AT TIMES TODAY.  
WE'LL CALL IT A MIX OF SUN AND CLOUDS, THOUGH BREAKS IN THE  
CIRRUS DECK WILL BE RELATIVELY INFREQUENT.  
 
EXPECT MAX TEMPS TO VARY FROM THE UPPER 40S ACROSS THE HIGH  
TERRAIN OF THE NORTH AND WEST TO THE LOW AND MID 50S ACROSS MUCH  
OF THE REMAINDER OF CENTRAL PA. SOME UPPER 50S ARE STILL  
POSSIBLE ACROSS THE FAR SE ZONES WHERE THE LONGEST DURATION OF  
SUNSHINE WILL OCCUR BEFORE THE HIGH CLOUDS BEGIN TO THICKEN UP.  
 
A RATHER EXTENSIVE AND THICK SHIELD OF MID AND HIGH CLOUDS  
TONIGHT WILL LEAD TO MIN TEMPS IN THE UPPER 30S (EAST) TO MID  
40S (SW MTNS) WHICH WILL BE A HEALTHY 8-15 DEG F ABOVE NORMAL. A  
NORTHERN STREAM SHORTWAVE WILL PIVOT ACROSS THE EASTERN GREAT  
LAKES INTO THE NEW ENGLAND STATE FOR LATE TONIGHT INTO EARLY  
MONDAY. THIS FEATURE WILL SEND A WEAK COLD FRONT THROUGH THE  
REGION AND TRIGGER SOME LIGHT RAIN SHOWERS DOWNWIND OF LAKE ERIE  
NEAR AND TO THE NORTH OF THE NY BORDER.  
 
 
   
SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/  
 
RIDGING SFC AND ALOFT RETURNS ON MONDAY, BRINGING DRY  
CONDITIONS WITH MILDER DAYTIME TEMPERATURES IN THE 55-65F RANGE  
(+10-15 DEGREES ABOVE THE HISTORICAL AVERAGE). MORNING CLOUDS  
ASSOCIATED WITH THE AFOREMENTIONED FRONT WILL CLEAR OUT AS THE  
DAY GOES ON, GIVING WAY TO A MOSTLY SUNNY MIDDAY TO AFTERNOON.  
HIGH CLOUDS WILL BEGIN STREAMING IN BY SUNSET AHEAD OF THE NEXT  
WEATHER MAKER.  
 
UPPER LEVEL RIDGING OVER PA SHOULD PROVIDE AT LEAST THE CENTRAL  
AND EASTERN ZONES WITH MILD AND MOSTLY RAIN-FREE CONDITIONS FOR  
THE BULK OF TUESDAY. HOWEVER, WARM ADVECTION ASSOCIATED WITH A  
WEAKENING SHORTWAVE LIFTING INTO THE GRT LKS MAY LEAD TO  
INCREASING LATE AFTERNOON/EVENING CLOUDS AND PERHAPS A FEW  
SHOWERS, MAINLY OVER THE NW MTNS. FOCUS THEN SHIFTS TO A CUT-  
OFF UPPER LOW DROPPING INTO THE MIDWEST.  
 
ON WEDNESDAY, BETTER MOISTURE MOVES INTO THE REGION AND SHOULD  
SUPPORT MORE CLOUDS AS WELL AS AN INCREASING CHANCE FOR SHOWERS  
INTO THE EVENING. HIGHS ON WEDNESDAY WILL BE IN THE 50S AND  
60S.  
 
 
   
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/  
 
BY WEDNESDAY NIGHT, A SURFACE COLD FRONT AND AN ASSOCIATED  
DEEPENING UPPER LOW WILL MOVE INTO PENNSYLVANIA, USHERING IN  
WIDESPREAD RAIN SHOWERS OVERNIGHT WEDNESDAY INTO THURSDAY ALONG  
WITH COOLER TEMPERATURES.  
 
MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT ABOUT THE  
PERSISTENCE OF THIS PATTERN AND KEEPS SUB 0C 850MB TEMPS  
OVERHEAD (OR NOT TOO FAR AWAY) THROUGH THE WEEKEND. THIS COLD  
AIR ALOFT WILL COMBINE WITH WELL ABOVE NORMAL WATER TEMPERATURES  
ON THE GREAT LAKES TO PRODUCE A PROLONGED PERIOD OF LAKE  
ENHANCED AND UPSLOPE SHOWERS THURSDAY THROUGH AT LEAST SATURDAY.  
 
THE COOLER TEMPERATURES AT THE SURFACE AND ALOFT WILL SUPPORT  
RAIN CHANGING OVER TO SNOW AT TIMES THROUGH THE WEEKEND. THE  
BEST CHANCE FOR ACCUMULATING SNOWFALL WILL BE IN THE TYPICAL  
UPSLOPE/LAKE EFFECT REGIONS OF THE LAUREL HIGHLANDS AND  
NORTHWEST MOUNTAINS, BUT SNOWFLAKES COULD EXTEND SOUTHEAST OF  
THE ALLEGHENY FRONT AT TIMES.  
 
IN ADDITION TO FREQUENT PRECIPITATION AND COLD TEMPERATURES,  
GUSTY WEST- NORTHWEST WINDS ARE ALSO ANTICIPATED FOR SEVERAL  
DAYS INTO NEXT WEEKEND. AS THE SURFACE LOW DEEPENS AND LIFTS  
NORTHEASTWARD, WRAP AROUND NORTHWESTERLY FLOW WILL BUFFET  
CENTRAL PA WITH GUSTS PERHAPS ABOVE 30MPH. PERSISTENT CLOUD  
COVER AND COOLER TEMPERATURES ALOFT WILL KEEP HIGH TEMPERATURES  
IN THE UPPER 30S TO NEAR 50, WHICH IS MUCH COOLER THAN WE'RE  
USED TO, BUT STILL ONLY A FEW DEGREES BELOW NORMAL FOR THIS TIME  
OF YEAR.  
 
 
   
AVIATION /00Z MONDAY THROUGH FRIDAY/  
 
HIGH CLOUDS CONTINUE TO STREAM ACROSS THE AIRSPACE THIS EVENING.  
EXPECT LOWERING CEILINGS THROUGHOUT THE NIGHT ACROSS THE WESTERN  
HALF OF THE STATE IN CONJUNCTION WITH A WEAK COLD FRONT. AS OF  
THE 00Z GUIDANCE MVFR IS ONLY ANTICIPATED AT BFD AND JST.  
INITIAL MVFR RESTRICTIONS ARE PROGGED BY A COMBINATION OF  
GLAMP/RAP GUIDANCE TOWARDS THE 07-08Z TIMEFRAME AT BFD, ALTHOUGH  
THERE REMAINS A SMALL POSSIBILITY THAT THE LOW LEVEL CLOUDS  
COULD ARRIVE SLIGHTLY EARLIER. THERE WILL ALSO REMAIN A PERIOD  
WHERE CEILINGS COULD (~30-40% PROBABILITY) DIP BETWEEN 700 AND  
1000FT AGL OUTLINED IN BEST IN THE 00Z/12Z HREF AT BFD;  
CONFIDENCE IS SLIGHTLY HIGHER IN IFR CIGS OCCURRING FOR A BRIEF  
TIME AT BFD THIS MORNING.  
 
AT OTHER WESTERN AIRFIELDS (JST/AOO/UNV), MODEL GUIDANCE DOES  
SHOW FAIRLY GOOD AGREEMENT WITH RESPECT TO CEILINGS LOWERING  
TOWARDS MVFR THRESHOLDS AT JST, WITH LESS SIGNALS IN MVFR  
CEILINGS PREVAILING AT AOO/UNV. AS OF THIS TAF PACKAGE VFR IS  
THE MOST LIKELY SOLUTION. AFTER SUNRISE ON MONDAY, GENERALLY  
EXPECT SCATTERING OUT OF THE LOWER- LEVEL CLOUD DECK QUICKLY  
ACROSS EASTERN PENNSYLVANIA. SOME RESIDUAL LOW- LEVEL CLOUDS  
WILL REMAIN AT JST/BFD, WITH THE BULK OF MODEL GUIDANCE  
GENERALLY HOLDING ONTO LOW CEILINGS UNTIL THE 16-17Z MONDAY  
TIMEFRAME.  
 
IT IS WORTH NOTING THAT WHILE NO LLWS MENTIONS WERE MADE IN  
THIS TAF PACKAGE THERE IS A SIGNAL FOR INCREASING LOW- LEVEL  
WINDS ON THE LEEWARD SIDE OF THE ALLEGHENY MOUNTAINS AHEAD OF  
A SHORTWAVE AT 850MB. WINDS ARE LIKELY TO REMAIN BELOW LLWS  
CRITERIA, BUT AOO/UNV STILL HAVE A CHANCE (~20%) TO GET CLOSE  
FOR A FEW HOURS AFTER 05Z.  
 
OUTLOOK...  
 
TUE...MAINLY DRY WITH VFR CONDITIONS.  
 
WED...RESTRICTIONS POSS, MAINLY NW. MORE WIDESPREAD  
RESTRICTIONS WITH RAIN AND LLWS WED NIGHT.  
 
THU-FRI...RESTRICTIONS LIKELY WITH RAIN AND SNOW SHOWERS.  
 
 
   
CTP WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
SYNOPSIS...BANGHOFF  
NEAR TERM...LAMBERT/BANGHOFF  
SHORT TERM...LAMBERT/BANGHOFF  
LONG TERM...BANGHOFF/NPB  
AVIATION...NPB/BOWEN  
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