967
FXUS61 KCTP 240940
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
540 AM EDT FRI JUL 24 2026
WHAT HAS CHANGED
NO SIGNIFICANT CHANGES OTHER THAN FOCUSING THE GREATEST PROBS
FOR SHOWERS/TSRA MONDAY AFTERNOON THROUGH TUESDAY.
KEY MESSAGES
1) PLEASANT/DRY PATTERN WITH COMFORTABLY LOW DAYTIME HUMIDITY
CONTINUES INTO THE LAST WEEKEND OF JULY.
2) TURNING MORE HUMID WITH SEVERAL ROUNDS SHOWERS AND THUNDERSTORMS
NEXT WEEK. PERHAPS A FEW STRONG STORMS WITH HEAVY RAIN AT
TIMES.
DISCUSSION
KEY MESSAGE 1: PLEASANT/DRY PATTERN WITH COMFORTABLY LOW DAYTIME
HUMIDITY CONTINUES INTO THE LAST WEEKEND OF JULY.
SURFACE HIGH PRESSURE EXTENDING FROM THE LOWER GREAT LAKES TO
THE NEW ENGLAND STATES WILL BRING ANOTHER SEVERAL DAYS OF VERY
PLEASANT MID SUMMER CONDITIONS WITH ABUNDANT SUNSHINE TODAY AND
A MIX OF SUN AND CLOUDS FOR SATURDAY AND SUNDAY.
WHILE THERE COULD BE ONE OR TWO HIGHLY ISOLATED SHOWERS OR
A THUNDERSTORM OVER THE REGION LATE THIS WEEKEND (MAINLY OVER
WESTERN PORTIONS OF THE STATE), THE AIRMASS REMAINS QUITE DRY.
HIGH TEMPERATURES TODAY AND SATURDAY WILL RANGE FROM THE MID TO
UPPER 70S ACROSS THE HIGHER TERRAIN, TO THE LOW 80S IN THE
CENTRAL AND SOUTHERN VALLEYS.
KEY MESSAGE 2: TURNING MORE HUMID WITH SEVERAL ROUNDS OF SHOWERS
AND THUNDERSTORMS NEXT WEEK. PERHAPS A FEW STRONG STORMS LATE
MONDAY AND TUESDAY AFTERNOON/EVENING.
HIGHLY DIFFLUENT NORTHWESTERLY FLOW ACCENTUATED BY A FEW
SHORTWAVES DROPPING SOUTHEAST ACROSS THE GREAT LAKES REGION
WILL LEAD TO AN INCREASING PROBABILITY FOR SHOWERS AND
THUNDERSTORMS. THE HIGHEST CHANCE FOR CONVECTION WILL COME
MONDAY AFTERNOON AND EVENING AND AGAIN ON TUESDAY AS A FAIRLY
COMPACT, BUT POTENT MID AND UPPER LEVEL SHORT WAVE DIGS SE AND
AMPLIFIES SIGNIFICANTLY AS IT REACHES OUR LONGITUDE.
THE INITIAL ROUND OF SHRA/TSRA WILL TRACK SE ALONG A SLOW-MOVING
WARM FRONT AND COULD BE ON THE STRONG TO SEVERE SIDE LATE
MONDAY/MON EVENING ACROSS PARTS OF CENTRAL AND WESTERN PA
WPC HAS A BROAD LEVEL 1/4 MARGINAL EXCESSIVE RAIN RISK FOR
D5/MONDAY JULY 27 THAT COVERS MOST OF CPA.
SFC LOW TRACKING FROM LAKE SUPERIOR ON MONDAY AND DEEPENING BY
ABOUT 6 MB (TO AROUND 995 MB) BY THE TIME IT REACHES LAKE
ONTARIO AT 18Z TUESDAY WILL HELP TO FOCUS TSRA IN PA DURING THE
DAY TUESDAY ALONG, AND AHEAD OF A SURFACE COLD FRONT (THAT WILL
BE OVER NW PA LATE TUESDAY MORNING WITH A WELL-DEFINED LEE
TROUGH EXTENDING DOWN THE SUSQ AND DELAWARE VALLEYS TUES
AFTERNOON/EARLY EVENING).
AVIATION /09Z FRIDAY THROUGH TUESDAY/
VALLEY FOG FORMATION HAS LARGELY STAYED OUT OF BFD THIS MORNING
WITH WIDESPREAD VFR CONDITIONS AS OF 09Z FRIDAY. THERE STILL
WILL REMAIN SOME POTENTIAL FOR MVFR-TO-IFR VISIBILITIES THROUGH
11Z FRIDAY BEFORE CHANCES RAPIDLY DECREASE. IN TERMS OF THE 12Z
TAF PACKAGE, WIDESPREAD VFR CONDITIONS ARE VIRTUALLY CERTAIN
(OVER 90% CONFIDENCE) AT ALL AIRFIELDS WITH LIGHT WINDS
THROUGHOUT THE DAY. THE MAIN CONCERN IN TERMS OF THE 12Z TAF
PACKAGE WILL BE THE POTENTIAL FOR CLEARING AND CALM WINDS
BETWEEN 06Z-12Z SATURDAY THAT WILL BRING SOME POTENTIAL FOR
VALLEY FOG POTENTIAL ACROSS THE NORTHERN TIER TERMINALS WITH
HIGHEST POTENTIAL AT BFD AFTER 09Z SATURDAY. CONFIDENCE REMAINS
TOO LOW TO INCLUDE IN THE 12Z TAF PACKAGE BASED ON A PERSISTENCE
FORECAST BUT WILL NEED TO CONTINUE TO MONITOR THIS POTENTIAL IN
FUTURE TAF PACKAGES.
OUTLOOK...
SAT...GENERALLY VFR CONDITIONS WITH LOW-END (< 20%) CHANCE OF AN
AFTERNOON SHOWER/STORM ACROSS WESTERN SECTIONS OF CENTRAL PA.
SUN...INCREASING CHANCES OF PM SHOWERS/STORMS, WITH SOME
RESTRICTIONS POSSIBLE.
MON-TUE...RESTRICTIONS POSSIBLE IN SHOWERS/STORMS.
CLIMATE
MULTIPLE RECORD LOW TEMPERATURES WERE SET FOR JULY 23RD ACROSS
CENTRAL PENNSYLVANIA:
* ALTOONA SET A RECORD LOW TEMPERATURE OF 47 DEGREES WAS SET,
BREAKING THE PREVIOUS RECORD OF 50 DEGREES SET BACK IN 1981.
* BRADFORD TIED A RECORD LOW TEMPERATURE OF 38 DEGREES WHICH
WAS PREVIOUSLY SET IN 1981.
* JOHNSTOWN TIED A RECORD LOW TEMPERATURE OF 49 DEGREES WHICH
WAS PREVIOUSLY SET IN 1983.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
WHAT HAS CHANGED...LAMBERT
KEY MESSAGES...LAMBERT
DISCUSSION...LAMBERT
AVIATION...BEATY
CLIMATE...BEATY
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