Buttonwood, Pennsylvania Weather Forecast Discussion

715
FXUS61 KCTP 190849
AFDCTP
Area Forecast Discussion
National Weather Service State College PA
449 AM EDT Fri Sep 19 2025
.SYNOPSIS...
* The last several days of this summer of 2025 will feature
  above average daytime temperatures with no rainfall through
  the weekend
* Remaining warmer than normal into late September with some
  much needed/light rainfall possible at times next week
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Surface cold front extended from just north of KBGM to KBFD and
KCLE at 08Z with an area of sct-bkn strato cu along and just in
its wake.
This boundary will drift slowly to the south through the state
today with very little fanfare. Along and just to the south of
the front will be an approx 100 NM wide band of 1-1.25 inch PWAT
air with sfc dewpoints in the upper 50s to low 60s across
Central and Southern PA. By early this evening, the initial
East/West orientation of the front will take on more of a
backdoor look, stretching from NE Ohio to SE PA. To its north,
PWATs will drop to between 0.5-0.7 of an inch with just some
scattered pancake strato cu.
Max temps this afternoon will vary from the low to mid 70s
across the Northern Tier of PA to the upper 80s in the Scent
Valleys. A few readings of 90-92F are likely across Franklin
County where the combination of orographic descent and
downsloping just south of the cfront from the top of the shallow
cooler airmass via a 10-15 kt northerly wind.
High temp departures will be near normal over our far NE zones
and +12-14 over the southern half of PA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
Clear/cool/chilly conditions for tonight/Saturday morning with
valley fog. We leaned lower vs. NBM for minT with some upper 30s
likely in the usual northern tier cold spots.
Cooler trend/not as warm across the board for daytime highs on
Saturday (-1 to -5F north, -5 to -10F south) 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.
Low clouds are forecast to develop later Saturday night into
early Sunday morning in association with an east to southeast
wind. The clouds will result in a milder minT trend with fcst
lows about +10F warmer across the NW mtns vs. Friday night.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Heading into next week, high pressure will begin to lose its
grip on the region as an upper trough tries to disrupt the
persistent ridge of high pressure aloft. Still plenty of
uncertainty on how much, if any, precipitation will get into
Pennsylvania, but southerly flow ahead of the approaching system
will support continued warmer than average temperatures for the
start of Astronomical fall.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
VFR conditions are virtually certain (~100% confidence) at all
airfields outside of BFD through 00Z Saturday with all model
guidance pointing towards clear skies and light wind (generally
below 5 kts) overnight and scattered cumulus development wind
winds generally between 5-10 kts during the afternoon hours. Low
cloud potential remains increasingly likely based on HREF
probabilities and recent RAP/GLAMP model guidance, especially in
the 09Z-13Z timeframe where there is high confidence (~70-80%)
in IFR/LIFR conditions prevailing. There remains low-end fog
potential at BFD; however the bulk of fog formation is expected
to stay just outside of the airfield. VFR conditions could be
slow to improve at BFD, trending closer to the 13-14Z timeframe,
before VFR conditions are expected through 00Z Sat.
Outlook...
Sat...AM valley fog; VFR.
Sat Night-Sun...Sub-VFR low clouds possible.
Mon-Tue...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...Lambert/Steinbugl
NEAR TERM...Lambert/Steinbugl
SHORT TERM...Lambert/Steinbugl
LONG TERM...Lambert/Banghoff
AVIATION...NPB/Tyburski
CLIMATE...Steinbugl

NWS CTP Office Area Forecast Discussion