Watsonville, Pennsylvania Weather Forecast Discussion

773
FXUS61 KCTP 191824
AFDCTP
Area Forecast Discussion
National Weather Service State College PA
224 PM EDT Fri Sep 19 2025
.SYNOPSIS...
* Above average daytime temperatures to close out astronomical
  summer 2025
* Trending mostly cloudy by the end of the weekend with rain
  most likely across the northwest part of the area Tuesday
&&
.NEAR TERM /THROUGH TONIGHT/...
A stray/brief passing shower or sprinkle is possible through
the evening across the Laurel Highlands and south central
Alleghenies toward the WV/MD panhandle where CAM output and
frontal/instability setup is most favorable/bullish. Latest
radar trends show an modest uptick in spotty shower coverage
tracking south-southeast from north of KIPT across Westmoreland
toward Somerset County/MD line.
Cu field fades into tonight with a mainly clear and relatively
cool overnight period. Min temps drop into the 40-55F range
with upper 30s probable in the usual northern tier cold spots.
Some valley fog is possible, although model signal is not that
strong with a 3-5F T/Td spread which appears to be the result
of llvl dry air advection via N/NE flow.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Not as warm (but still above climo) to start the last weekend
of astronomical summer. There will be plenty of sun, but the
wind from the east will deliver cooler air vs. Friday with the
largest 24hr MaxTdeltas across the southern tier (-10F day/day).
Low clouds are forecast to develop Saturday night into early
Sunday morning in association with an increasingly moist
ESE upslope flow. Locally dense ridgetop fog and widespread low
stratus signal is now showing up in the hires model QPF field
and "goal-post" fcst soundings. The cloud cover and moist
easterly flow will result in a milder minT trend with fcst lows
about +10F warmer across the northern half of the fcst area vs.
Friday night/AM Saturday.
Cool air damming pattern on Sunday suggests some downside to
max temps depending on breakup of a.m. low clouds. Best odds for
rain during the period will be late Sunday night into early
Monday across the NW zones along a lifting warm frontal zone and
LLJ.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
Strong sfc high shifts to the Northeastern Seaboard early next
week. This will allow a +tilt upper level trough and llvl
frontal boundary to move southeast from the Great Lakes bringing
the best odds for rain particularly on Tuesday focused across
the northwest 1/2 of central PA.
A lot of uncertainty in the guidance regarding a possible Omega/
blocking pattern setting up over the CONUS by the middle of
next week with cutoff low in the Central U.S. This opens up
plenty of downstream solutions and outcomes for both precip and
temperatures. NBM data indicates a gradual cooling trend back to
within a few degrees of the historical average (highs 65-75) for
the end of September by the end of next week.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
High confidence in VFR prevailing through the 19/18Z TAF period.
A few showers have developed to the west/southwest of KJST/KAOO
where a bkn-sct VFR cu field should fade away by tonight. T/Td
spreads in the tabular GLAMP are generally not supportive of
fog restrictions so did not include in the TAF at this time.
Outlook...
Sat...VFR.
Sat Night-Sun...MVFR/IFR cigs likely; trending MVFR/VFR by
Sunday afternoon.
Mon-Wed...Rain showers possible; best odds over the NW 1/2 of
the airspace.
&&
.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...Steinbugl
AVIATION...Steinbugl
CLIMATE...Steinbugl

NWS CTP Office Area Forecast Discussion