675
FXUS61 KCTP 270226
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1026 PM EDT FRI JUN 26 2026
WHAT HAS CHANGED
INCREASING CONFIDENCE IN SIGNIFICANT HEAT AND HUMIDITY NEXT WEEK
(JULY 1-4).
KEY MESSAGES
1) PERIODS OF LIGHT TO BRIEFLY MODERATE RAIN
TONIGHT INTO SATURDAY; LINGERING RISK FOR A POP UP SHOWER ON
SUNDAY.
2) INCREASING HEAT RISK BUILDS THROUGH THE MIDDLE AND LATTER
PART OF NEXT WEEK WITH A CHANCE FOR THUNDERSTORMS RISING INTO
THE END OF THE WEEK.
DISCUSSION
KEY MESSAGE 1: PERIODS OF LIGHT TO BRIEFLY MODERATE RAIN
TONIGHT INTO SATURDAY; LINGERING RISK FOR A POP UP SHOWER ON
SUNDAY.
A WAVE OF LOW PRESSURE WILL DRIFT EAST ALONG THE STALLED OUT
FRONT TO OUR SOUTH TONIGHT, BRINGING PERIODS OF LIGHT TO
MODERATE RAIN. THE BEST UPPER LEVEL ENERGY IN THE FORM OF A
SHORTWAVE WILL DRIFT OVERHEAD AROUND DAYBREAK SATURDAY, WHICH IS
WHEN THE RAIN WILL BE MOST WIDESPREAD. AS THE SHORTWAVE MOVES
EAST OF THE REGION, THE COVERAGE OF RAIN SHOULD SLOWLY DIMINISH
DURING THE MIDDAY AND AFTERNOON HOURS.
THE COMBINATION OF PERSISTENT CLOUDS AND WIDESPREAD RAIN (AT
LEAST IN THE MORNING) WILL KEEP TEMPERATURES ON THE COOL SIDE,
GENERALLY IN THE 70S ACROSS THE ENTIRE FORECAST AREA. DEWPOINTS
WILL RISE INTO THE LOW 70S IN THE SOUTH, WHICH WILL MAKE IT
FEEL RATHER UNCOMFORTABLE HUMIDITY-WISE.
STORM TOTAL RAINFALL TONIGHT INTO SATURDAY COULD EXCEED AN INCH
IN A FEW SPOTS ACROSS SOUTHERN PA, WHILE MUCH LOWER AMOUNTS ARE
EXPECTED NORTH OF INTERSTATE 80 WHERE LESS THAN 0.30 OF AN INCH
IS EXPECTED.
SHOWERS SHOULD BECOME MORE SCATTERED DURING THE AFTERNOON AND
THE RISK FOR LIGHTNING APPEARS RATHER LOW. BY SUNDAY, HIGH
PRESSURE WILL BEGIN TO MOVE INTO NORTHERN PA, BRINGING SLIGHTLY
LOWER DEWPOINTS AND DRIER CONDITIONS. BUT A FEW SHOWERS OR
THUNDERSTORMS COULD DEVELOP DURING THE AFTERNOON MAINLY ALONG
AND SOUTH OF I-80, CLOSER TO THE FRONT AND BEST MOISTURE.
---------------------------------------------------------------
KEY MESSAGE 2: INCREASING HEAT RISK BUILDS THROUGH THE MIDDLE
AND LATTER PART OF NEXT WEEK WITH A CHANCE FOR THUNDERSTORMS
RISING INTO THE END OF THE WEEK.
A DEEP TROUGH SETTLING INTO THE PACIFIC NORTHWEST AND
INTERMOUNTAIN WEST THIS WEEKEND WILL LIKELY RESULT IN A
DOWNSTREAM UPPER RIDGE DEVELOPING OVER THE EASTERN US BY EARLY
NEXT WEEK. BLENDED ENSEMBLE GUIDANCE DRIVING THE PROTOTYPE
PROBABILISTIC HEATRISK IS SHOWING A SIGNAL FOR A SIGNIFICANT
WARMUP FOR CENTRAL PA TO END JUNE AND START JULY. WITH
INCREASING CONFIDENCE IN AN UPPER LEVEL RIDGE OVER THE OHIO
VALLEY, HIGH TEMPERATURES WILL LIKELY EXCEED 90 DEGREES OVER A
LARGE PORTION OF THE AREA TOWARDS THE END OF THE FORECAST PERIOD
(TUE-FRI). HEIGHT AND TEMPERATURE FIELDS ARE PROGGED TO BE 2 TO
3 STANDARD DEVIATIONS ABOVE NORMAL, PLACING THEM ABOVE THE 99TH
PERCENTILE. IN ADDITION TO ANOMALOUS HEIGHTS AND TEMPERATURES,
LOW LEVEL MOISTURE WILL ALSO BE ABOVE NORMAL. THIS COMBINATION
OF ANOMALOUS HEAT AND HUMIDITY WILL PUSH HEAT INDEX VALUES OVER
100 DEGREES BY MID TO LATE WEEK, ESPECIALLY IN THE LOWER SUSQ
VALLEY. THE CLIMATE PREDICTION CENTER HAS HIGHLIGHTED ALL OF
PENNSYLVANIA IN A HIGH RISK FOR EXTREME HEAT ON FRIDAY 7/3 AND A
MODERATE RISK ON SATURDAY 7/4.
DEPENDING ON THE EXACT POSITIONING OF THE RIDGE, THERE MAY ALSO
BE SOME POTENTIAL FOR CLUSTERS OF SHOWERS AND THUNDERSTORMS
MOVING IN FROM THE NORTHWEST IN A CLASSIC 'RING OF FIRE'
PATTERN. MACHINE LEARNING GUIDANCE HIGHLIGHTS POTENTIAL FOR
DAILY AFTERNOON STORMS WEDNESDAY THROUGH FRIDAY, WITH RELATIVELY
LOWER PROBABILITIES UNTIL THEN. THIS TYPE OF PATTERN COULD ALSO
SUPPORT SOME HIGHER END SEVERE POTENTIAL IN THE FORM OF
MESOSCALE CONVECTIVE SYSTEMS RIDING ALONG THE RIDGE, SOME OF
WHICH TENDING TO LAST INTO THE OVERNIGHT HOURS. WE'LL CONSIDER
THIS A LOW PROBABILITY, HIGH IMPACT EVENT AT THIS POINT. ANYONE
OVERSEEING FOURTH OF JULY WEEKEND EVENTS SHOULD CONTINUE TO
MONITOR THE FORECAST CLOSELY FOR THE POTENTIAL OF IMPACTS FROM
BOTH HEAT AND SEVERE WEATHER.
AVIATION /01Z SATURDAY THROUGH WEDNESDAY/
CEILINGS WILL LOWER WEST TO EAST TONIGHT AS A LOW PRESSURE SYSTEM
APPROACHES, WITH SCATTERED -RA/-SHRA MOVING IN MAINLY AFTER
MIDNIGHT. INTERMITTENT IFR VISIBILITY RESTRICTIONS ARE POSSIBLE
IN THE STEADIEST SHOWERS (PWATS INCREASE TO AROUND 1.5"
OVERNIGHT, IMPROVING RAINFALL EFFICIENCY), THOUGH MOST SHOWERS
WILL BE LIGHT WITH VFR-MVFR FAVORED. CONFIDENCE IS LOW REGARDING
THE NORTHERN EXTENT & ONSET OF THIS ACTIVITY AS A RESULT OF
DRIER AIR NEAR THE SURFACE TO START, WITH THE HRRR BRINGING
PATCHES OF STEADIER RAIN FARTHER NORTH (KBFD/KIPT) & MOST OTHER
GUIDANCE FARTHER SOUTH. BEST FORCING FOR A MORE ORGANIZED BATCH
OF RAIN IS LATE TONIGHT INTO SATURDAY MORNING.
STEADY RAIN IN THE MORNING WILL GIVE WAY TO SCATTERED SHOWERS
HEADING INTO SATURDAY AFTERNOON, WITH MODERATE CONFIDENCE IN
TIMING OF THIS TRANSITION. THE PROBABILITY FOR LIGHTNING IS LOW.
OUTLOOK...
SUN...FOG AND LOW CIGS POSSIBLE IN THE MORNING, THEN SCATTERED
AFTERNOON SHOWERS AND STORMS.
MON-WED...AM FOG; OTHERWISE VFR. TRENDING HOTTER WITH ISOLD PM
T-STORMS PSBL.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
WHAT HAS CHANGED...LAMBERT/BANGHOFF
KEY MESSAGES...LAMBERT/BANGHOFF
DISCUSSION...LAMBERT/BANGHOFF
AVIATION...COLBERT/TEARE
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page