617
FXUS61 KCTP 290904
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
504 AM EDT SAT AUG 29 2026
WHAT HAS CHANGED
* WPC MRGL EXCESSIVE RAINFALL RISK LEVEL 1 ADDED FOR WED. (9/2)
KEY MESSAGES
1) LATE SUMMER HEAT+HUMIDITY TO CLOSE AUGUST AND OPEN SEPTEMBER
2) BOUTS OF HEAVY RAIN & SEVERE STORMS POSSIBLE MONDAY-WEDNESDAY
DISCUSSION
AFTER A SEASONABLY COOL AND REFRESHING OVERNIGHT-EARLY MORNING
WITH PREDAWN/DAYBREAK TEMPS IN THE USUAL NORTHERN TIER COLD
SPOTS FLIRTING WITH A 3 HANDLE, ENJOY A VERY PLEASANT AND
COMFORTABLE START TO THE WEEKEND WITH LOW HUMIDITY. RADIATIONAL
FOG IN THE WESTERN AND NORTH CENTRAL RIVER AND STREAM VALLEYS
WILL FADE BY 14Z/10AM.
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KEY MESSAGE 1: LATE SUMMER HEAT+HUMIDITY TO CLOSE AUGUST AND
OPEN SEPTEMBER
THE LATEST AVAILABLE MODEL GUIDANCE HAS A FAIRLY GOOD HANDLE ON
THE OVERALL LARGE SCALE PATTERN THROUGH THE MIDDLE OF NEXT WEEK.
THE DOMINANT SYNOPTIC FEATURE WILL BE A SPRAWLING 500MB
ANTICYCLONE GRADUALLY EXPANDING TO THE EAST NORTHEAST FROM THE
CENTRAL/SOUTHERN PLAINS TO THE SOUTHERN MID ATLANTIC AND
SOUTHEAST. THIS WILL DELIVER A STRETCH OF VERY WARM AND HUMID
CONDITIONS WITH TEMPERATURES RISING SEVERAL DEGREES ABOVE THE
HISTORICAL AVERAGE FROM SUNDAY (LAST DAY OF AUGUST) THROUGH
WEDNESDAY (FIRST FEW DAYS OF SEPTEMBER).
KEY MESSAGE 2: BOUTS OF HEAVY RAIN & SEVERE STORMS POSSIBLE
MONDAY-WEDNESDAY
A SERIES OF DYNAMIC SHORTWAVES AND FRONTAL SYSTEMS TRACKING
EASTWARD ALONG THE NORTHERN PERIPHERY OF THE ELONGATED UPPER
RIDGE WILL INTERACT WITH HIGH HUMIDITY/VERY HIGH PWS, STRONG
MID LEVEL FLOW/FAVORABLE JET STREAKS, AND INSTABILITY TO
PRODUCE A FEW EPISODES OF HEAVY RAINFALL AND POSSIBLE SEVERE
WEATHER DURING THE FIRST PART OF NEXT WEEK. THERE ARE TYPICAL
TIMING AND AMPLITUDE DIFFERENCES OF THE SMALLER SCALE
DISTURBANCES THAT WILL NEED TO BE RESOLVED, BUT THE CONVECTIVE
SIGNAL IS SUPPORTIVELY BULLISH FOR A COUPLE ROUNDS OF STRONG TO
SEVERE STORMS AND AT LEAST LOCALIZED AREAS OF POTENTIALLY
EXCESSIVE RAINFALL. WPC HAS CONTINUED TO HIGHLIGHT PORTIONS OF
NORTH CENTRAL PA WITH A MARGINAL RISK FOR MONDAY & TUESDAY
FOLLOWED BY A NEW, BROADER COVERAGE FOR WED/D5. SPC HAS
MAINTAINED THE 15% OR LEVEL 2/5 EQUIVALENT SEVERE PROBS ON
WEDNESDAY WHILE ACKNOWLEDGING ADDITIONAL PROBS WILL LIKELY BE
NEEDED ON EITHER SIDE OF DAY 5 BASED ON MEDIUM RANGE ML AND AI
GENERATED GUIDANCE.
AVIATION /07Z SATURDAY THROUGH WEDNESDAY/
1025 MB SURFACE HIGH PRESSURE OVER WESTERN PA EARLY THIS MORNING
WILL DRIFT SLOWLY TO THE EAST-SOUTHEAST TODAY, BRINGING VFR WITH
LIGHT WIND, EXCELLENT VISIBILITY AND VARIABLE AMOUNTS OF MAINLY
THIN CIRRUS CLOUDS DRIFTING SE FROM THE GREAT LAKES REGION.
THE ONLY BLEMISH IN THIS OTHERWISE EXCELLENT FLYING WEATHER WILL
BE THE LIKELIHOOD OF ABOUT 3-4 HOURS (08-12Z) OF MVFR VSBYS IN
FOG AND PERHAPS A 1-2 HOUR PERIOD (08-10Z) OF IFR THROUGHOUT
THE DEEPER RIVER VALLEYS OF NORTHERN PA WHERE THE AIR/WATER TEMP
DIFFERENCE WILL REACH 25-28 DEG F IN SOME PLACES.
HREF PROBS OF IFR VISIBILITY ARE LESS THAN 20 PERCENT AT ALL
TAF SITES, BUT BFD, UNV, AND IPT COULD STILL SEE BRIEF PERIODS
OF VISIBILITY LESS THAN 3 MILES.
WINDS WILL BE LIGHT AND VARIABLE DURING THE DAYLIGHT HOURS TODAY
AND WILL ONCE AGAIN DIMINISH TO NEAR CALM TONIGHT/EARLY SUNDAY.
OUTLOOK...
SUN-TUE...MAINLY VFR. ISOLD SHRA/TSRA POSSIBLE.
WED...SCT SHRA/TSRA WITH BRIEF RESTRICTIONS POSSIBLE.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
WHAT HAS CHANGED...STEINBUGL
KEY MESSAGES...STEINBUGL
DISCUSSION...STEINBUGL
AVIATION...LAMBERT/BAUCO
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