064
FXUS61 KCTP 021921
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
321 PM EDT WED SEP 2 2026
WHAT HAS CHANGED
* RISK OF DAMAGING WINDS AND TORNADO POTENTIAL INCREASED OVER
THE NORTHERN TIER
KEY MESSAGES
1) LATE SUMMER SURGE OF HEAT AND HUMIDITY CONTINUES SEVERE
THUNDERSTORM AND EXCESSIVE RAINFALL THREAT THROUGH THURSDAY
DISCUSSION
KEY MESSAGE 1: LATE SUMMER SURGE OF HEAT AND HUMIDITY CONTINUES
SEVERE THUNDERSTORM AND EXCESSIVE RAINFALL THREAT THROUGH
THURSDAY
A SERIES OF MID LEVEL IMPULSES TRACKING EASTWARD ALONG THE
NORTHERN PERIPHERY OF AN EXPANSIVE 500MB RIDGE WILL CONTINUE TO
INTERACT WITH ANOMALOUS MOISTURE/INSTABILITY AND STRONG WNW FLOW
ALOFT TO PROMOTE SEVERE STORM AND EXCESSIVE RAIN RISK THROUGH
THURSDAY.
AFTER A ROUND OF SEVERE STORMS THIS MORNING, ROBUST
DESTABILIZATION IS OCCURRING ACROSS WESTERN AND CENTRAL PA WITH
PLENTY OF HEATING AND VERY RICH DEWPOINTS IN THE 70-75F RANGE.
MORE THUNDERSTORMS ARE EXPECTED THIS AFTERNOON THROUGH THE
EVENING IN AN CONVECTIVE ENVIRONMENT HIGHLY SUPPORTIVE OF
ORGANIZED STORMS CAPABLE OF ALL SEVERE WEATHER HAZARDS. THERE IS
ALSO THE POTENTIAL FOR HEAVY RAIN AND FLASH FLOODING ESPECIALLY
WERE STORMS REPEAT OVER THE SAME AREA.
INCREASED SOUTHWEST TO WESTERLY FLOW ON THURSDAY WILL PUSH THE
WILL CONTINUE TO PUMP IN THE LATE SUMMER HEAT AND VERY HIGH
DEWPOINTS. HEAT ADVISORY REMAINS IN EFFECT FROM 11A-8P THURSDAY
ACROSS A PORTION OF SOUTH CENTRAL PA WHERE MAX HEAT INDEX VALUES
ARE PROJECTED TO REACH/EXCEED 100F.
THE SEVERE RISK WILL BE FOCUSED MORE ACROSS THE SOUTHWEST
QUADRANT OF CENTRAL PA THURSDAY, AND SOUTH OF THE PA-MD BORDER
ON FRIDAY. AN UPPER TROUGH PASSAGE FAVORS ONE FINAL ROUND OF
SHOWERS AND STORMS ON FRIDAY, BUT FORTUNATELY THE LABOR DAY
WEEKEND IS TRENDING DRY. THE UPPER RIDGE IS FORECAST TO
RETROGRADE BY THE END OF THE WEEK WHICH ALLOWS FOR A RETURN TO
MORE SEASONAL TEMPERATURES AND LOWER HUMIDITY THIS WEEKEND INTO
EARLY NEXT WEEK.
AVIATION /19Z WEDNESDAY THROUGH MONDAY/
SOME OF THE LEAST CERTAIN TERMINAL FORECASTS I HAVE EVER MADE,
EVEN DURING LAKE EFFECT SNOWS. THE POSSIBILITY, BUT NOT
CERTAINTY, OF CONVECTION EXISTS THROUGHOUT THE ENTIRE TAF
PERIOD FOR ALMOST ALL SITES. POINTING OUT A FEW MORE-LIKELY
TIMES ARE THE BEST I COULD DO AT THIS POINT. AFTER A PATCH OF
SHRA/TSRA AFFECTS IPT THIS AFTN, IT COULD SLIDE S INTO MDT/LNS,
BUT IT IS NOT MORE THAN A 40% CHC OF GETTING TO THOSE TWO SITES.
MOST GUIDANCE THEN DEVELOPS CONVECTION OVER WESTERN PA AND
SLIDING INTO THE AIRSPACE OVER CENTRAL PA BEFORE 22Z. THAT
POSSIBLE AREA OF SHRA/TSRA COULD (50%) LAST INTO THE LATE
EVENING WHILE INCHING EASTWARD. A SIGNIFICANT PUSH OF FORCING
MOVES IN FROM NY TOWARD 03Z. THE BATCH OF CONVECTION IT WILL
FIRE UP HAS BEEN FAIRLY CONSISTENT WITH PREVIOUS GUIDANCE AND
WOULD DROP INTO A POOL OF VERY LOW STABILITY AND HIGH MOISTURE.
THESE SHRA/TSRA WOULD CERTAINLY DROP INTO BFD AND THEN IPT-UNV.
THEY COULD SURVIVE INTO THE SOUTHERN HALF OF THE AIRSPACE FOR
THE POST- SUNRISE HOURS. I WOULD HAVE PUT MORE/LOWER VISBY FOG
INTO THE TERMINALS IF I THOUGHT IT WOULD CLEAR OUT AFTER THE SUN
SETS. STILL MENTIONED A PERIOD OF FOG FOR THE WESTERN TERMINALS
LATER TONIGHT.
OUTLOOK...
THU...SCATTERED-NUMEROUS SHRA/TSRA WITH BRIEF RESTRICTIONS
POSSIBLE; MORNING FOG.
FRI...SCATTERED SHRA/TSRA SW. VFR ELSEWHERE AFTER MORNING FOG.
SAT-MON...VFR FAVORED; MORNING FOG POSSIBLE.
CTP WATCHES/WARNINGS/ADVISORIES
HEAT ADVISORY FROM 11 AM TO 8 PM EDT THURSDAY FOR PAZ026>028-
035-036-056-057-059-063>066.
WHAT HAS CHANGED...STEINBUGL
KEY MESSAGES...STEINBUGL
DISCUSSION...STEINBUGL
AVIATION...DANGELO
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page