567
FXUS61 KCTP 090901
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
501 AM EDT TUE JUN 9 2026
WHAT HAS CHANGED
* SLIGHT DECREASE IN TEMPERATURES THROUGHOUT MUCH OF THE WEEK
WITH AN INCREASE IN CLOUD COVER AND PRECIPITATION CHANCES.
KEY MESSAGES
1) INCREASING HEAT AND HUMIDITY THIS WEEK WILL BRING INCREASED
RISK FOR HEAT-RELATED ILLNESSES, ESPECIALLY THURSDAY AND FRIDAY.
2) SHOWER AND THUNDERSTORM CHANCES BEGIN LATER TODAY (TUESDAY)
AND CONTINUE THROUGH THE END OF THE WORK WEEK.
DISCUSSION
KEY MESSAGE 1: INCREASING HEAT AND HUMIDITY THIS WEEK WILL
BRING INCREASED RISK FOR HEAT-RELATED ILLNESSES, ESPECIALLY
THURSDAY AND FRIDAY.
INCREASING HEAT AND HUMIDITY IS ALMOST CERTAIN THROUGHOUT THE
REST OF THE WEEK; HOWEVER, THE EXACT MAGNITUDE OF HEAT WILL BE
THE MAIN UNCERTAINTY WITH RESPECT TO THE FORECAST OVER THE NEXT
COUPLE OF DAYS. MAIN DRIVER FOR THE UNCERTAINTY WILL BE CLOUD
COVER AND OCCASIONAL SHOWERS/STORMS THROUGHOUT THE WEEK, WITH
SCATTERED COVERAGE EXPECTED WEDNESDAY AND THURSDAY AND MORE
WIDESPREAD COVERAGE ON FRIDAY (SEE KEY MESSAGE 2) LIKELY
ALLOWING FOR A SLIGHT DOWNTREND IN TEMPERATURES. FORECAST
PACKAGE THIS MORNING KEPT FAIRLY CLOSE TO PREVIOUS FORECAST
OUTSIDE OF POTENTIALLY KNOCKING DOWN TEMPERATURES ANOTHER DEGREE
OR TWO AS MODEL GUIDANCE HAS TRENDED SLIGHTLY MORE AGGRESSIVE
ON CLOUD COVER. DEW POINTS HAVE STAYED MAINLY STATIONARY WITH
THIS FORECAST PACKAGE; HOWEVER, NOT COMPLETELY UNREASONABLE TO
SEE A SLIGHT UPTICK IN FUTURE FORECAST PACKAGES. IF ANYTHING,
LOOKS LIKE SLIGHTLY LOWER HEATRISK ON THURSDAY WITH SLIGHTLY
HIGHER ON FRIDAY. THE MAIN DRIVER FOR SLIGHTLY INCREASED RISK ON
FRIDAY MAINLY HONES IN ON SLIGHTLY WARMER LOW TEMPERATURES
THURSDAY NIGHT INTO FRIDAY MORNING AND ARE NOT REPRESENTATIVE OF
A SUBSTANTIAL INCREASE IN TEMPERATURES OR DEW POINTS. CURRENT
POSTURE FOR MENTIONS IN HWO WITH NO PRODUCTS APPEARS TO CONTINUE
TO BE THE WAY FOR THIS FORECAST CYCLE; HOWEVER, PROBABILITIES
IN REACHING HEAT ADVISORY CRITERIA HAVE LARGELY FALLEN OVER
MULTIPLE CYCLES WITH THE ONLY LOCATION POTENTIALLY HITTING
CRITERIA ACROSS THE LOWER SUSQUEHANNA VALLEY THURSDAY AND
FRIDAY.
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KEY MESSAGE 2: SHOWER AND THUNDERSTORM CHANCES BEGIN LATER
TODAY (TUESDAY) AND CONTINUE THROUGH THE END OF THE WORK WEEK.
RAIN CHANCES BEGIN TO INCREASE ACROSS WESTERN PENNSYLVANIA
LATER TODAY, WITH AN EXTENDED STRETCH (FOUR-TO-FIVE DAYS) OF
RAINFALL ACROSS SOME PORTION OF CENTRAL PENNSYLVANIA. COVERAGE
OF SHOWERS AND THUNDERSTORMS REMAINS THE MAIN QUESTION WITH
RESPECT TO THE FORECAST, AS IT USUALLY IS IN THIS SET-UP, WITH
SCATTERED COVERAGE IN SHOWERS AND THUNDERSTORMS EXPECTED
WEDNESDAY AND THURSDAY. INCREASED MOISTURE AND BETTER FORCING
(IN THE FORM OF A STRONG UPPER-LEVEL LOW) IS EXPECTED TO BE
COLLOCATED ACROSS THE REGION ON FRIDAY, THUS HIGHER CONFIDENCE
IN MORE WIDESPREAD PRECIPITATION CHANCES FRIDAY, ESPECIALLY
DURING THE AFTERNOON AND EVENING HOURS AT THIS TIME. SPC HAS
UPGRADED ALL OF CENTRAL PENNSYLVANIA INTO MARGINAL RISKS FOR
SEVERE THUNDERSTORMS ON WEDNESDAY AND THURSDAY, LIKELY GIVEN TO
THE VERY UNSTABLE AIR ACROSS THE REGION. FORCING IS NOT THE
GREATEST AND SHEAR REMAINS AN UNCERTAINTY; HOWEVER, SOME
POTENTIAL FOR DAMAGING WINDS WILL BE POSSIBLE IN STRONG-TO-
SEVERE THUNDERSTORMS FOR THE MIDDLE OF THE WEEK. WE'LL ALSO NEED
TO KEEP AN EYE ON SEVERE POTENTIAL AS WE GET CLOSER TO THE
LATTER HALF OF THE WEEK WITH AMPLE INSTABILITY IN PLACE WITH
SHEAR BEING THE BIGGEST QUESTION MARK AT THIS TIME. IN THE "FOR
WHAT IT'S WORTH" CATEGORY, MACHINE-LEARNING PROBABILITIES FOR
SEVERE WEATHER DO OUTLINE FRIDAY FOR SOME SEVERE POTENTIAL
ACROSS CENTRAL PENNSYLVANIA, LIKELY GIVEN THE ENHANCED FORCING
AND INSTABILITY IN PLACE ACROSS THE REGION.
AVIATION /08Z TUESDAY THROUGH SATURDAY/
ANTICYCLONIC FLOW AROUND A DEPARTING HIGH PRESSURE SYSTEM WILL
BRING DRIER AIR ACROSS THE EASTERN HALF OF THE COMMONWEALTH
THIS MORNING. A MOISTURE GRADIENT WILL SET UP ALONG THE
ALLEGHENIES, WITH PWATS AROUND 1.50" JUST WESTWARD WHERE HIGH
PRESSURE INFLUENCE HAS BEEN WEAKER.
THE WARM/MOIST AIR WILL CONTINUE CREEPING EASTWARD AS
THE HIGH PRESSURE LOSES INFLUENCE OVER OUR AREA, WITH EVEN A FEW
SHOWERS (COVERAGE <30%) POSSIBLE ACROSS OUR WESTERN TERMINALS
(PRIMARILY KBFD/KJST/KAOO/KUNV) BETWEEN AFTER 18Z TODAY. FLIGHT
RESTRICTIONS ARE NOT EXPECTED WITH THESE SHOWERS, THOUGH
BRIEFLY STEADY RAIN MAY OCCUR GIVEN THE MOISTURE IN PLACE.
LIGHTNING MAY ALSO BE POSSIBLE, THOUGH THE TALL/SKINNY LOW-CAPE
(<500 J/KG) PROFILE WILL FAVOR RAINFALL EFFICIENCY OVER
LIGHTNING PRODUCTION.
CEILINGS WILL LOWER FROM WEST TO EAST TONIGHT, WITH IFR
CONDITIONS FAVORED AT BFD/JST AND MVFR AT THE REST OF THE
AIRFIELDS BEFORE DAWN ON WEDNESDAY.
OUTLOOK...
WED-THU...RESTRICTIONS POSSIBLE IN SCATTERED -SHRA/-TSRA.
FRI...RESTRICTIONS EXPECTED IN A LINE OF -TSRA.
SAT...MAINLY VFR.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
WHAT HAS CHANGED...BEATY
KEY MESSAGES...BEATY
DISCUSSION...BEATY
AVIATION...BANGHOFF/COLBERT
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