218
FXUS61 KCTP 291653
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1253 PM 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
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).
THE HEAT WILL PEAK TUESDAY AND WEDNESDAY WITH TEMPERATURES
RANGING FROM THE MID 80S TO MID 90S. HEAT INDEX VALUES COULD
APPROACH THE CENTURY MARK ACROSS THE SOUTH CENTRAL MOUNTAINS
EACH AFTERNOON AS WELL. OVERNIGHT LOWS IN THE 60S AND 70S WILL
PROVIDE LITTLE RELIEF FROM DAYTIME HEAT. THIS WARM/HUMID AIR
WILL ALSO PROVIDE AMPLE FUEL FOR THUNDERSTORMS AS THE WEEK WEARS
ON.
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 MIDDLE 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 /18Z SATURDAY THROUGH THURSDAY/
1025 MB SURFACE HIGH PRESSURE 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. WINDS WILL BE LIGHT
AND VARIABLE DURING THE DAYLIGHT HOURS TODAY AND WILL ONCE AGAIN
DIMINISH TO NEAR CALM TONIGHT/EARLY SUNDAY.
AIR/WATER TEMP DIFFERENCES TONIGHT AND EARLY SUNDAY SHOULD BE
10-12 DEG F LESS THAN WHAT WE JUST HAD THIS MORNING, WHICH
DIDN'T PRODUCE MUCH FOG. THEREFORE, WON'T CONSIDER ANYTHING
LOWER THAN 6SM BR AT THIS POINT AT KBFD AND KIPT, CONSIDERING
THAT DETERMINISTIC AND ENSEMBLE NUMERICAL GUIDANCE KEEPS SFC
TEMP/DEWPOINT SPREADS OF 4 DEG F OR MORE LATE TONIGHT/EARLY
SUNDAY.
LATE TONIGHT, LOW LEVEL SOUTHEASTERLY FLOW MAY LEAD TO THE
DEVELOPMENT/NWWD ADVECTION OF A STRATOCU DECK, BASED MAINLY
BETWEEN 2500 - 4000 FT AGL. THIS COULD LEAD TO A COUPLE HOURS
OF MVFR RESTRICTIONS AT LNS AND MDT TOWARD DAYBREAK SUNDAY.
OUTLOOK...
SUN...MAINLY VFR. ISOLATED SHRA/TSRA POSSIBLE.
MON-TUE...ROUNDS OF SHRA/TSRA WITH BRIEF RESTRICTIONS POSSIBLE.
MORNING FOG.
WED-THU...SCT SHRA/TSRA WITH BRIEF RESTRICTIONS POSSIBLE.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
WHAT HAS CHANGED...STEINBUGL
KEY MESSAGES...STEINBUGL/BANGHOFF
DISCUSSION...STEINBUGL/BANGHOFF
AVIATION...LAMBERT/BANGHOFF
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