886   
FXUS61 KCTP 300000  
AFDCTP  
  
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE STATE COLLEGE PA  
800 PM EDT WED OCT 29 2025  
   
SYNOPSIS  
  
* PERIODS OF STEADY, MODERATE TO BRIEFLY HEAVY RAIN DEVELOPING   
  ACROSS THE LAUREL HIGHLANDS LATE TODAY AND OVER THE REMAINDER   
  OF CENTRAL PA TONIGHT THROUGH THURSDAY AFTERNOON, BEFORE   
  TAPERING TO RAIN SHOWERS THURSDAY NIGHT INTO FRIDAY  
* TURNING WINDY AND CHILLY FOR HALLOWEEN WITH WINDS SLOWLY  
  DECREASING OVER THE FIRST WEEKEND OF NOVEMBER WITH OROGRAPHIC  
  AND LAKE ENHANCED SHOWERS MOST LIKELY OVER THE WESTERN   
  ALLEGHENIES  
* ANOTHER RAINY STORM POSSIBLE FOR ELECTION DAY.  
  
  
   
NEAR TERM /UNTIL 6 AM THURSDAY MORNING/  
  
LAYERED CLOUDS WILL BEGIN TO SPREAD RAPIDLY NORTH ACROSS THE   
REGION EARLY THIS EVENING AS DEEP LAYER MID-LEVEL FLOW   
GRADUALLY VEERS AND INCREASES THETA-E ADVECTION WITHIN THE   
LAYER.   
  
BROAD SCALE UVVEL INCREASES THIS AFTERNOON AND EVENING. SOME   
LIGHT RAIN WILL DEVELOP OVERHEAD/SPREAD OVER THE LAUREL   
HIGHLANDS AROUND DUSK AND CONTINUE TO EXPAND NNE ACROSS THE CWA  
THROUGH EARLY TONIGHT. THE AXIS OF A GOOD PLUME OF MOISTURE   
WAITS UNTIL AFTER 00Z TO SLIDE EAST OF I-99 AND NORTH OF I-80.  
THE ONSET OF THE RAIN WILL OCCUR ACROSS THE NE MTNS AROUND   
MIDNIGHT.  
  
19Z SFC TEMPS (MAINLY IN THE LOW TO MID 50S) ARE WITHIN A DEG F  
OF FORECAST HIGHS AT ALL LOCATIONS. COOLEST AIR RESIDED ACROSS  
THE LAUREL HIGHLANDS WITH TEMPS IN THE LOW TO MID 40S.   
  
SFC WINDS WILL CONTINUE OUT OF THE E/NE THROUGH TONIGHT AND  
INCREASE AS A STRENGTHENING SOUTHEAST TO SOUTHERLY LLJ SPREADS   
NORTH INTO THE STATE.  
  
  
   
SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/  
  
THE HEAVIEST OF THE RAIN WILL COME BETWEEN MIDNIGHT AND LATE   
THURSDAY AFTN WITH THE 6 AM TO 1 PM PERIOD POTENTIALLY HOSTING  
THE HEAVIEST RAIN ACROSS THE SCENT MTNS AND MIDDLE/LOWER SUSQ  
VALLEY AS A PLUME OF DEEP TROPICAL MOISTURE LINKED TO THE   
WESTERN PART OF HURRICANE MELLISA (AND THE CENTRAL AND NORTHERN  
BAHAMAS) SLIDES EAST ACROSS THE AFOREMENTIONED AREA.   
  
A DRY SLOT SHOULD WORK IN FROM THE S IN THE LATE AFTN/EVENING  
HOURS. THE INSTABILITY ALOFT AND TO THE EAST OF THE DRY SLOT   
COULD MAKE SOME THUNDER. THUS, THE QPF OF 1.5"-2" CONTINUES TO   
LOOK SOLID, THOUGH 24 HOUR PMM VALUES VIA THE HREF LIGHT UP A  
STRIPE OR TWO OF 3+ INCH AMOUNTS NEAR AND TO THE EAST OF THE MID  
AND LOWER SUSQ RIVER.   
  
LUCKILY, THE PROGRESSIVE NATURE OF THE STORM AND THE 12-18 HR   
TIME FRAME OVER WHICH THE BULK OF THE RAIN FALLS SHOULD KEEP   
FLOODING WORRIES SOMEWHAT LOW. SOME CLOGGED STORM DRAINS WILL   
CAUSE PROBLEMS, BUT LARGE STREAM AND RIVER FLOODING IS NOT   
ANTICIPATED TO BE A PROBLEM. THE SFC LOW PASSES LATE IN THE DAY   
AND EARLY EVENING, WHICH THEN ALLOWS THE W WIND TO KICK IN. SOME  
GUSTS INTO THE 30S ARE EXPECTED THURS NIGHT AND FRI, MAINLY IN   
THE LAURELS AND TO SOME EXTENT OVER MUCH OF THE SOUTHERN TIER.   
FRIDAY WILL BE THE WINDIEST TIME AS WE MIX UP TO ABOUT 3-5KFT   
(DEEPER IN THE E) DESPITE CAA. NEITHER SUSTAINED SPEEDS NOR   
GUSTS ARE EXPECTED TO REACH ADVY THRESHOLDS. THE FLOW ACROSS THE  
LAKES WILL MAKE NUMEROUS SHRA FOR THE NW HALF OF THE AREA.  
  
  
   
LONG TERM /FRIDAY THROUGH WEDNESDAY/  
  
BREEZY/WINDY AND RATHER CHILLY FOR HALLOWEEN EVENING WITH   
SHOWERS CONTINUING TO SPILL TO THE SOUTHEAST OF LAKE ERIE. THE  
GUSTS WILL START TO DIMINISH FRI NIGHT, BUT NOT GO AWAY. TRICK   
OR TREAT CONDITIONS LOCALLY LOOK RATHER UNPLEASANT WITH A WIND-   
CHILLED TEMPERATURE AROUND 40 DEGREES.   
  
COLLABORATED WITH SURROUNDING WFOS TO INCREASE WIND GUSTS BY 5-8  
KTS WHICH PLACES PEAK GUSTS IN THE 40-45 MPH RANGE, TICKLING  
WIND ADVISORY CRITERIA FRIDAY INTO FRIDAY EVENING.  
  
CHILLY CONDITIONS (GENERALLY A FEW DEG F BELOW NORMAL IN MOST   
PLACES) CONTINUE FOR THE START OF NOVEMBER WITH MODEL GUIDANCE   
SHOWING A REINFORCING SHOT OF COOLER AIR DRIVING INCREASED   
SHOWER ACTIVITY DOWNWIND OF LAKE ERIE ACROSS THE ALLEGHENY   
FRONT. MARGINAL TEMPS MAY BE SUPPORTIVE OF RAIN/SNOW SHOWERS   
PARTICULARLY IN THE HIGHEST ELEVATIONS EARLY NEXT WEEK.  
  
THE ECMWF IS STARTING TO LOOK A LITTLE MORE LIKE THE GFS FOR THE  
ELECTION DAY TIME FRAME. THAT MIGHT MEAN A MATURE STORM, MUCH   
LIKE THE PRESENT ONE, WILL AFFECT THE MID-ATLANTIC STATES   
AGAIN. THE TEMPS MAY BE A LITTLE CHILLIER, ESP BEHIND THE   
(POTENTIAL) SYSTEM. JURY STILL OUT ON THIS ONE.  
  
  
   
AVIATION /00Z THURSDAY THROUGH MONDAY/  
  
00Z UPDATE... DETERIORATING CONDITIONS ARE EXPECTED FOR THE   
CENTRAL PA TAF SITES OVERNIGHT INTO EARLY THURSDAY. SOME LATE   
DAY IMPROVEMENT ON THURSDAY IS POSSIBLE OVER SOUTHERN PARTS OF   
THE COMMONWEALTH, AS A DRY SLOT ALOFT MOVES OVERHEAD.  
  
A STEADY INFUSION OF ATLANTIC MOISTURE WILL LEAD TO LOWERING  
CEILINGS AND ULTIMATELY THE ONSET OF STEADY RAINFALL FROM LATER  
THIS EVENING THROUGH MOST OF THURSDAY AREA-WIDE. THE ONSET OF  
IFR RESTRICTIONS SHOULD TAKE PLACE FROM 03-06Z, WITH STEADY-  
STATE RESTRICTIVE CONDITIONS THEN IN PLACE THROUGH MUCH OF  
THURSDAY. VERY HIGH CONFIDENCE IN THIS SCENARIO (90+%). BRIEF   
PERIODS OF MODERATE-HEAVY RAIN ARE PROBABLE.  
  
MORE UNCERTAINTY EXISTS AS TO THE TIMING OF IMPROVING CONDITIONS  
FROM SOUTH-NORTH THURSDAY AFTERNOON INTO THE EVENING. THE MOST  
LIKELY TIMING AND LOCATIONS ON THIS ARE FOR THE SOUTHERN AND   
EASTERN AIRFIELDS (KAOO/KMDT/KLNS) AFTER 20-22Z. THERE IS   
MODERATE CONFIDENCE (40-60%) ON THIS SCENARIO.  
  
ALTHOUGH NOT STRICTLY MENTIONED IN THE TERMINALS, THERE IS SOME  
POTENTIAL FOR THUNDERSTORMS IN THE VICINITY OF KLNS AND KMDT  
FROM ROUGHLY 16-21Z THURSDAY. AT THIS EARLY JUNCTURE,   
CONFIDENCE IS NOT YET HIGH ENOUGH TO INCLUDE IN THE FORECAST.   
  
A STRENGTHENING E-SE LOW-LEVEL JET IN THE UPPER PORTION OF THE  
BOUNDARY LAYER (45-55 KT AT 2000-4000 FEET AGL) WILL LEAD TO   
PROBABLE LLWS CONDITIONS FOR MAINLY THE EASTERN HALF OF PA FROM   
THURSDAY MORNING INTO THE EARLY AFTERNOON.   
  
OUTLOOK...  
  
FRI-SAT...WINDY FRIDAY WITH WNW GUSTS OF 30 TO 35+ KTS. STAYING  
BREEZY SATURDAY WITH FREQUENT SHOWERS DOWNWIND OF LAKE ERIE.  
  
SUN...LOW CLOUDS COULD BE PERSISTENT, PARTICULARLY OVER THE  
WESTERN HALF OF THE AIRSPACE.  
  
  
   
CTP WATCHES/WARNINGS/ADVISORIES  
  
NONE.  
  
  
  
  
  
SYNOPSIS...LAMBERT/DANGELO  
NEAR TERM...LAMBERT/DANGELO  
SHORT TERM...DANGELO  
LONG TERM...DANGELO/STEINBUGL  
AVIATION...JUREWICZ/LAMBERT  
 
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