248
FXUS61 KCTP 012332
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
732 PM EDT SUN JUN 1 2025
SYNOPSIS
* A CHILLY NIGHT IS IN STORE WITH FROST EXPECTED TO FORM OVER
PORTIONS OF NORTHERN PA.
* DRY CONDITIONS PREVAIL FOR THE FIRST HALF OF THE WEEK, BEFORE
SHOWER AND THUNDERSTORM CHANCES RETURN BY THURSDAY.
* A TREND TOWARDS MUCH WARMER, SUMMER-LIKE CONDITIONS IS
FORESEEN THIS WEEK.
NEAR TERM /THROUGH MONDAY/
CLOUD COVER CONTINUES TO DECREASE ACROSS MUCH OF THE REGION
THIS EVENING AS WE LOSE DAYTIME HEATING, THOUGH SOME OF THE
CUMULUS OVER TIOGA COUNTY HAS GROWN TALL ENOUGH TO PRODUCE A
FEW SHOWERS WHICH WILL QUICKLY DISSIPATE AFTER SUNSET.
CLEARING SKIES AND CALM WINDS OVERNIGHT WITH HIGH PRESSURE
BUILDING IN AT THE SURFACE WILL SUPPORT EFFICIENT RADIATIONAL
COOLING. WHILE GUIDANCE SUGGESTS THAT THERE WILL STILL BE SOME
SMOKE OVERHEAD FROM CANADIAN WILDFIRES, THE IMPACT ON
TEMPERATURES IS EXPECTED TO BE MINIMAL. LOW TEMPERATURES WILL
LIKELY RANGE FROM THE MID 30S OVER THE NORTH AND WEST TO THE MID
40S IN THE SOUTHEAST. THIS WILL SUPPORT FROST FORMATION AND A
FROST ADVISORY REMAINS IN EFFECT FOR THE PORTIONS OF NORTH-
CENTRAL PA. IT IS POSSIBLE THAT PATCHY FROST FORMATION OCCURS IN
THE NORMAL COLD SPOTS OUTSIDE OF THE CURRENT ADVISORY, BUT
CONFIDENCE IN FROST FORMATION IS LOWER IN THOSE LOCATIONS.
HIGH PRESSURE WILL PROVIDE DRY WEATHER FOR MONDAY WITH MAINLY
CLEAR SKIES EXPECTED THROUGH MUCH OF THE DAY. HIGH TEMPERATURES
WILL RANGE FROM THE MID 60S OVER THE NORTHERN AND WESTERN
MOUNTAINS, TO THE LOW TO MID 70S ELSEWHERE. HRRR VERTICALLY
INTEGRATED SMOKE SUGGESTS THAT SIMILAR AMOUNTS OF SMOKE TO TODAY
WILL TRAVERSE THE REGION, CAUSING THE SKY TO APPEAR HAZY.
SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/
AS THE UPPER LEVEL TROUGH THAT HAS BEEN POSITIONED OVER THE
NORTHEASTERN US THE PAST FEW DAYS EXITS TO THE EAST MONDAY
NIGHT, A MOISTURE-STARVED SHORTWAVE WILL DIVE SOUTHWARDS
TOWARDS EASTERN PA. NO SENSIBLE WEATHER IMPACTS ARE EXPECTED,
OUTSIDE OF A SLIGHT INCREASE IN HIGH CLOUDS. HIGH PRESSURE AT
THE SURFACE AND ALOFT WILL ALLOW FOR DRY CONDITIONS TO CONTINUE
INTO THE MIDDLE OF THE WEEK.
AS THE HIGH SLOWLY DRIFTS EASTWARD, SOUTHERLY RETURN FLOW
DEVELOPS AND USHERS IN MUCH WARMER AND HUMID AIR. ENSEMBLE MEAN
850 MB TEMPERATURES RANGE FROM 15 TO 17 DEGREES C BY WEDNESDAY
WHICH SUPPORTS HIGH TEMPERATURES IN THE MID TO UPPER 80S. IT IS
CERTAINLY POSSIBLE THAT A FEW LOCATIONS SEE TEMPERATURES REACH
90 DEGREES WEDNESDAY AFTERNOON OVER SOUTHEASTERN PENNSYLVANIA.
LONG TERM /THURSDAY THROUGH SUNDAY/
HIGH PRESSURE BEGINS TO SHIFT FURTHER EAST THURSDAY MORNING
WITH MODEL GUIDANCE OUTLINING MODEST AGREEMENT IN A WEAK AREA OF
LOW PRESSURE WEST OF THE AREA GRADUALLY MOVING CLOSER TO
CENTRAL PENNSYLVANIA. SURGING PWATS AND LOWERING HEIGHTS AHEAD
OF THIS AREA OF LOW-PRESSURE SUPPORT PRECIPITATION MENTIONS JUST
AHEAD OF SUNRISE ON THURSDAY. AS LOW-PRESSURE APPROACHES AND
BETTER MOISTURE SPREADS INTO THE AREA THURSDAY AFTERNOON,
WIDESPREAD RAIN SHOWERS APPEAR INCREASINGLY LIKELY ON FRIDAY AS
AN ASSOCIATED COLD FRONT APPROACHES THE AREA. COLD FRONT IS
EXPECTED TO BE BEGINNING TO DECAY AT THIS JUNCTURE WITH LOWER
SHEAR VALUES AND MARGINAL CAPE. GIVEN THESE PARAMETERS, LOW
CONFIDENCE ON ANY SEVERE WEATHER CONCERNS ON THURSDAY.
CONFIDENCE IN THE FORECAST BECOMES LOWER AFTER FRIDAY; HOWEVER,
WITH ECMWF DETERMINISTIC GUIDANCE INDICATING DRIER CONDITIONS
EARLY SATURDAY THROUGH THE END OF THE LONG-TERM FORECAST PERIOD.
RECENT GFS DETERMINISTIC GUIDANCE DOES HOLD MOISTURE FURTHER
INTO CENTRAL PENNSYLVANIA FOR THE FIRST HALF OF SATURDAY BEFORE
TRENDING DRIER THROUGH THE END OF PERIOD. GIVEN THIS GUIDANCE,
HAVE OPTED TO STICK CLOSE TO NBM GUIDANCE SATURDAY AND SUNDAY;
HOWEVER, IN FUTURE CYCLES COULD REALISTICALLY SEE SUNDAY
TRENDING DRIER OVERALL.
AVIATION /23Z SUNDAY THROUGH FRIDAY/
HIGH PRESSURE WILL PROVIDE THE REGION WITH MAINLY CLEAR SKIES
AND VFR CONDITIONS INTO TUESDAY.
LOCATIONS LIKE CORNING, NY, IPT, AND BFD WILL HAVE SOME CHANCE
FOR A VERY BRIEF PERIOD OF FOG TONIGHT, BUT DEWPOINTS ARE QUITE
LOW AND A SLIGHT BREEZE MAY PREVAIL. MAIN THING GOING FOR ANY
FOG IS THE RECENT WET WEATHER. THUS THINK CHC OF FOG ON THE LOW
SIDE TONIGHT.
SOME SMOKE AT TIMES, BUT MAINLY ACROSS THE WEST AND SOUTH EARLY
ON TONIGHT. COULD BE SOME NORTHERN LIGHTS LATER.
OUTLOOK...
TUE-WED...VFR EXPECTED.
THU...POTENTIAL BRIEF RESTRICTIONS IN SHRA/TSRA NW.
FRI...NUMEROUS SHRA/TSRA, ESP NW. BRIEF REDUCTIONS TO MVFR AND
IFR IN THE TSRA.
CLIMATE
MAY 2025 PRECIPITATION RANKINGS
SITE 2025 | WETTEST MAY ON RECORD
-----------------------------------------------------------
HARRISBURG* 10.02" WETTEST | 9.71" IN 1989 (PREVIOUS)
WILLIAMSPORT 7.18" 7TH WETTEST | 9.91" IN 1919
ALTOONA* 7.34" WETTEST | 7.31" IN 1960 (PREVIOUS)
STATE COLLEGE 7.56" T-7TH WETTEST | 9.45" IN 1894
(* DENOTES THAT MAY 2025 SET A NEW RECORD IN PRECIPITATION IN
THEIR RESPECTIVE LOCATIONS. THE PREVIOUS RECORD REMAINS LISTED
UNDER THE "WETTEST MAY ON RECORD" COLUMN.)
CTP WATCHES/WARNINGS/ADVISORIES
FROST ADVISORY FROM 1 AM TO 7 AM EDT MONDAY FOR PAZ004>006-010-
011-017-037.
SYNOPSIS...DANGELO/BAUCO
NEAR TERM...BAUCO
SHORT TERM...BAUCO
LONG TERM...NPB
AVIATION...MARTIN
CLIMATE...NPB
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