714
FXUS61 KCTP 091133
AFDCTP

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

.SYNOPSIS...
* Dry and sunny conditions will continue through the weekend
  with near-average high temperatures.
* Frost/freeze concerns across northern and western Pennsylvania
  into Thursday morning, more widespread frost/freeze concerns
  Thursday evening into Friday morning.
* Precipitation chances increase this weekend and into the
  beginning of next week, with chances of precipitation confined
  to the northern tier for the middle of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Scattered cloud coverage across the northern tier will continue
to scatter out over the next hour or two, supplying clear
conditions that promote radiational cooling across central
Pennsylvania this morning. Frost Advisories across the northern
tier continue to track well based on current recent observations
with McKean County continuing to push towards sub- freezing
temperatures this morning so the Freeze Warning remains in good
shape through ~9am EDT 10/09. Influence of a ~1036mb surface
high pressure points towards clear skies for today (Thursday),
with all model guidance on board with that trend. This will
allow for high temperatures to generally range into the lower
50s across the Poconos to the lower 60s across the southern
tier, much cooler than high temperatures on Wednesday and will
set the stage for much cooler low temperatures Thursday night
into Friday morning.

Widespread frost/freeze concerns are in the forecast Thursday
night into Friday morning under an ideal set-up for radiational
cooling across much of the forecast area. Have continued to
introduce a NBM/NBM10pct blend for overnight low temperatures in
this timeframe, pushing low temperatures into the mid-to-upper
20s to the mid-30s across central Pennsylvania. Given the
aforementioned radiational cooling set-up and comparing to
recent MAV guidance, high confidence in the bulk of the area
receiving frost/freeze by Friday morning. All zones under the
Freeze Watch have been upgraded to a Freeze Warning, with some
expansion into south-central Pennsylvania where recent guidance
has trended cooler, bringing some potential for a (relatively)
early-season freeze. Further southeast, model guidance do
suggest the deepest valleys and sheltered locations of Dauphin,
Lebanon, York, and Lancaster counties could push towards
freezing temperatures; however, frost seems to be a more
plausible solution at this timeframe. Either way, preventative
measures are recommended to protect sensitive vegetation across
central Pennsylvania as frost and sub-freezing temperatures are
increasingly likely and could damage vegetation across the
forecast area.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
Surface high pressure promotes dry conditions continuing on
Friday with southerly flow allowing for temperatures to trend
slightly warmer. As the high pressure becomes more displaced
from the region on Saturday, a complex set-up is expected to
begin bringing increased precipitation chances for the weekend.

Model guidance continues to indicate a surface coastal low
stationed off the Mid-Atalntic Coast, coupled with an upper-
level area of low pressure stationed across the Great Lakes,
both bringing some potential for precipitation this weekend
across central Pennsylvania. Precipitation is expected to begin
entering the southeastern and northwestern fringes of central
Pennsylvania Saturday morning and continue into the afternoon
hours, which remains fairly well-resolved with recent
deterministic model guidance. The more uncertain part with
respect to the short-term forecast period remains interactions
with these two areas of low-pressure where moisture returns from
the coastal low could be pulled further into central
Pennsylvania, with some models overspreading precipitation
areawide later Saturday and continuing through Sunday. Recent
NBM model guidance has trended up with respect to rain chances
this weekend and given the aforementioned uncertainty, holding
off on any large-scale changes on this forecast cycle.

Rainfall with this coastal system will generally be beneficial
for a majority of the area. The main concern with respect to the
rainfall is easterly/southeasterly flow off of the Atlantic
bringing ample moisture returns across the eastern half of the
forecast area (PWATs in the ~1.00-1.50" range) will bring some
concerns for flash flooding, especially in the more urbanized
areas. This thinking is backed up the WPC, who has tagged
portions of the area with a Marginal Risk for Excessive Rain on
Sunday, especially later in the afternoon/evening hours where
moisture returns are best across southeastern Pennsylvania.
There still remains some uncertainty with respect to rainfall
amounts and exact magnitude of rainfall across central
Pennsylvania with this features, thus will need to continue to
monitor the forecast ahead of the weekend.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
Coastal low influence begins into the first portion (through
Monday evening) of the long-term forecast period as model
guidance does hint towards the surface low stalling out/slowing
down ever-so briefly before pushing eastward. Fortunately, best
moisture returns in this timeframe push slightly east of the
area, but still some signal for PWATs in the 1.00-1.25" range
across our eastern zones that outlines some potential for
locally heavy rainfall.

As the coastal low drifts further east, dry conditions are
expected to be the rule for most of central Pennsylvania Tuesday
morning/afternoon and through Wednesday outside of residual
showers across northwestern Pennsylvania. Temperatures in this
timeframe are expected to trend slightly above average for the
middle of October across central Pennsylvania.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
Widespread VFR conditions prevail through the TAF period under
mainly clear skies. Patchy valley fog will mix out by mid
morning giving way to cloud-free conditions. Winds will be out
of the northeast at around 5 knots today, and could reach up to
10 knots at MDT and LNS.

Winds taper off later this afternoon with high pressure moving
into eastern New York. Light southeast flow will develop
Thursday night as clear skies persist and widespread
frost/freeze conditions occur.

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...NPB
NEAR TERM...NPB
SHORT TERM...NPB
LONG TERM...NPB
AVIATION...Banghoff/Bauco