159
FXUS61 KCTP 090505
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
105 AM EDT Thu Oct 9 2025

.SYNOPSIS...
* Sunny but crisp conditions through late week
* Frost/freeze conditions this morning and Thursday night could
  end the growing season in some parts of central PA
* Increasing odds for cloudy/wet/windy weather Sunday into
  Monday particularly across the eastern part of the forecast
  area

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Looking at clear skies overnight, as a large high pressure
system builds southward from southern Canada.

Frost and freeze products look ok, just updated the statement.
Limiting factor will be a very slight wind overnight.

Earlier discussion below.

A seasonably strong +2SD 1030mb high pressure dome will migrate
over the eastern Great Lakes and continue to direct crisp and
chilly Fall air into CPA. Frost/freeze headlines remain
unchanged over the northern and western Alleghenies. Some
consideration was given toward adding counties along I-99 where
the usually colder valleys could wake up to areas of frost early
Thursday morning. Min temps in 30-45F range anywhere from 1-2
to 5-8 degrees below climo; however the 24hr change is a bit
more impressive at 15 to 25 degrees lower (colder) vs. last
night.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
Thursday looks to be the coldest day of the week, even with
plenty of sunshine. Thursday night will be a bit colder than
tonight, as there will be next to no wind. Also cooler on
Thursday than today. Freeze watch continues for much of the
area. Anyway, no chance to this part of the package.

Earlier discussion below.

Chilly start followed by abundant sunshine, lighter winds, and
the first cooler-than-average day in some time. Max temps will
be 5-10 degrees below the historical average for early October
making for a crisp, cool Autumn feel with low humidity.

1030+mb high pressure dome with PW <0.4" continues to drift to
the southeast into the Northeast US and channels down the
eastside of the Appalachians, setting up an ideal radiational
cooling pattern Thursday night into early Friday morning.

This should translate into the coldest night/morning of the
season so far with widespread frost and areas of sub-freezing
temperatures that could bring an end to the growing season.
Freeze watch remains well-positioned/unchanged with frost advy
considerations for the lower Susquehanna Valley.

Predawn/sunrise min temps in the 20-40 range should mark a short
term bottom with highs/lows moderating into the weekend in
response to veering low level flow - turning more to the south
southeast as the aforementioned high shifts off the New England
coast.

The latest model data is now trending toward a closed/cutoff
upper low over the Great Lakes by 12Z Saturday which could
introduce low end rain probs across far northwest PA. This
feature will also play a key role in the pattern taking shape
over the weekend into early next week.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
As was the case last evening, Sunday into early Tuesday looking
to be more on the cool, windy, and wet side, than just a few
days ago. Coastal low could really take off, given warm waters
just offshore. Will have to watch for convection which could
lead to rather strong pressure falls.

Earlier discussion below.

Saturday is trending toward more clouds and increasing rain
probs over southeast PA. Conditions on Sunday are also trending
downhill as the 08/12Z models continue to like the idea of
moisture being pulled north/northwest as the Great Lakes upper
low interacts with the Carolina coastal storm. Rain and perhaps
breezy/windy conditions may impact at least the southeast
portion of the forecast area Sunday into early next week.

Weather conditions should improve on the margin into the middle
of next week as the coastal low moves out to sea, but the exact
timing is still uncertain.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
Widespread VFR conditions prevail through the TAF period under
mainly clear skies. Patchy valley fog is possible early Thursday
morning, but the very dry airmass in place should limit
coverage and keep it away from any airfields. Winds will be out
of the north through the night at 5 knots and will become more
northeasterly after sunrise, increasing to around 5 to 10 knots.

Winds taper off Thursday afternoon with high pressure moving
into eastern New York. Light southeast flow will develop
Thursday night as clear skies persist.

Outlook...

Fri...VFR.

Sat-Mon...Low clouds and rain/wind potential increasing,
particularly over the southeast airfields as a coastal storm
tracks north.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Frost Advisory until 9 AM EDT this morning for PAZ004-006-010-
011-017-024-033-037.
Freeze Warning from 11 PM this evening to 9 AM EDT Friday for
PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-
049>053-056-058-063-064.
Freeze Warning until 9 AM EDT this morning for PAZ005.
Frost Advisory from 11 PM this evening to 9 AM EDT Friday for
PAZ057-059-065-066.

&&

$$

SYNOPSIS...Steinbugl/Banghoff/Martin
NEAR TERM...Steinbugl/Banghoff/Martin
SHORT TERM...Steinbugl/Banghoff/Martin
LONG TERM...Steinbugl/Banghoff/Martin
AVIATION...Banghoff/Bauco