634
FXUS61 KCTP 150810
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
410 AM EDT MON SEP 15 2025
SYNOPSIS
* BLOCKY/SLOW MOVING SEASONAL TRANSITION PATTERN WILL CONTINUE
THE EXTENDED RUN OF ABNORMALLY DRY WEATHER IN CENTRAL PA
THROUGH THE LAST WEEK OF ASTRONOMICAL SUMMER
NEAR TERM /THROUGH TONIGHT/
PREDAWN/POST-SUNRISE VALLEY FOG (CONCENTRATED IN THE NORTHERN
TIER RIVER/STREAM VALLEYS) WILL GIVE WAY TO A MIX OF LOW LEVEL
FAIR WX CU AND HIGH CIRRUS BY THE AFTERNOON WITH MAX TEMPS
+5-10F ABOVE THE HISTORICAL AVG IN THE MID 70S TO LOW 80S.
DESPITE HIGH CLOUDS, VALLEY FOG IS STILL A GOOD BET AGAIN
TONIGHT PARTICULARLY ACROSS THE NORTHERN TIER. LOW TEMPS ARE
NEAR TO SLIGHTLY ABOVE MID SEPTEMBER CLIMO IN THE UPPER 40S TO
UPPER 50S.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/
LOW PRESSURE WILL LIFT SLOWLY NORTHWARD FROM THE OUTER BANKS AND
VA TIDEWATER OFF THE MID ATLANTIC COAST THROUGH MIDWEEK. LATEST
MODEL DATA CONTINUES TO INDICATE THE BEST CHANCE FOR RAIN OVER
THE SOUTHEAST ZONES (SOUTHEAST OF I-81/78) WHERE A MOIST/UPSLOPE
EASTERLY LOW LEVEL FLOW WILL DELIVER HIGHER PWAT AIR. 48HR QPF
ENDING 12Z THU RANGES FROM <0.10 UP TO 0.50" WITHIN A TIGHT NW-
SE GRADIENT ACROSS THE LOWER SUSQ VALLEY WITH MAX AMOUNTS ALONG
THE MD LINE TO THE NORTH OF CHESAPEAKE BAY. LOCATIONS ALONG AND
NORTH/WEST OF THE US220/I99 CORRIDOR ARE NOT EXPECTED TO SEE ANY
RAINFALL WHICH COULD MANIFEST. THE MOST NOTEWORTHY CHANGES IN
SENSIBLE WX WILL BE MORE CLOUDS/LESS SUNSHINE AND A DAYTIME
COOLING TREND (LOWER HIGHS) THAT WILL BE MORE PRONOUNCED OVER
THE SOUTHEAST HALF OF THE CWA.
LONG TERM /THURSDAY THROUGH SUNDAY/
A BRIEF SPELL OF DRY CONDITIONS IS ONCE AGAIN EXPECTED IN THE
WAKE OF THE COASTAL LOW, WITH MODERATE-TO-HIGH CONFIDENCE IN DRY
CONDITIONS ON FRIDAY. RECENT MODEL GUIDANCE HAS SLIGHTLY SLOWED
DOWN WITH RESPECT TO THE LOW PRESSURE SYSTEM IN THE MIDWEST
WITH A FAIR AMOUNT OF UNCERTAINTY BETWEEN DETERMINISTIC MODEL
GUIDANCE. GIVEN THESE CHANGES, HAVE DECIDED TO ROLL WITH NBM
THROUGH SUNDAY, WITH THE BEST CHANCES OF PRECIPITATION COMING
AFTER SUNRISE ON SUNDAY.
AVIATION /07Z MONDAY THROUGH FRIDAY/
VALLEY FOG CAN BE SEEN FORMING ON SATELLITE AS OF 06Z AND WILL
CONTINUE TO EXPAND ACROSS NORTH-CENTRAL PA, AND POTENTIALLY
SOUTHEAST PA, INTO THE EARLY MORNING. WE HAVE KEPT ALL TAFS VFR
WITH THE 06Z PACKAGE AS CONFIDENCE ON IMPACTS REMAINS LOW. MODEL
SOUNDINGS SUGGEST THAT THE BEST POTENTIAL FOR ANY REDUCED
VISIBILITY WOULD BE AT BFD, IPT, AND LNS. FOG WILL DISSIPATE BY
14Z, GIVING WAY TO VFR CONDITIONS.
VARYING AMOUNTS OF HIGH CLOUDS WILL BE IN PLACE DURING THE DAY
ON TUESDAY AS A COASTAL LOW WELL TO OUR SOUTHEAST MOVES SLOWLY
NORTHWESTWARD. THE GREATEST AMOUNT OF CLOUD COVER WILL BE OVER
THE SOUTHEAST, WHILE AREAS NORTH OF I-80 MAY SEE MAINLY CLEAR
SKIES FOR MUCH OF THE DAY. THE CLOUDS WILL DECREASE IN COVERAGE
AFTER 06Z, ALLOWING FOR VALLEY FOG FORMATION.
OUTLOOK...
TUE...VFR WITH AM VALLEY FOG. ISOLATED SHRA POSSIBLE LATE FOR
SE PA.
WED-THU...GENERALLY VFR, SOME SHRA POSSIBLE (20-40%) SE PA.
FRI...VFR WITH AM VALLEY FOG.
CLIMATE
ASTRONOMICAL FALL OFFICIALLY BEGINS WITH THE AUTUMNAL EQUINOX
ON MONDAY, SEPTEMBER 22, 2025 @ 2:19 P.M. EDT. THE AUTUMN 2025
SEASON WILL LAST 89 DAYS, 20 HOURS, AND 43 MINUTES. DAYLIGHT
SAVING TIME WILL END JUST AFTER HALLOWEEN WITH CLOCKS FALLING
BACK AT 2 A.M. SUNDAY, NOVEMBER 2, 2025.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...STEINBUGL
NEAR TERM...STEINBUGL
SHORT TERM...STEINBUGL
LONG TERM...NPB
AVIATION...BAUCO
CLIMATE...STEINBUGL
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