689
FXUS61 KCTP 130547
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
147 AM EDT Tue Oct 13 2026

.WHAT HAS CHANGED...
Highlighted wind and frost/freeze risks in the HWO and Key
Messages.

&&

.KEY MESSAGES...
1) Big temperature swing ahead

2) Windy and wet end to the week with first flakes

3) Frost and freeze conditions this weekend

&&

.DISCUSSION...
KEY MESSAGE 1: Big temperature swing ahead

Max temperatures are projected to challenge daily records
Tuesday and Wednesday. Highs in the 70-85 range are 10 to 20
degrees above the historical average for mid October.

Contrast the early week record-challenging warmth with much
colder air coming on the horizon for the weekend. The difference
between max temps Tuesday vs. min temps Sat/Sun will be 40 to
50 degrees. Even more impressive will be the difference between
max temps Tuesday vs. minimum wind chill values which could
reach 50 to 60 degrees for some locations.

KEY MESSAGE 2: Windy and wet end to the week with first flakes

Little to no rain is expected through midweek. The most likely
period of widespread wet weather comes late in the week between
Thursday night and Friday as an amplified upper trough crosses
the Great Lakes and spins up a deep sfc low in the Gulf of Maine
into the Canadian Maritimes. While broader in overall coverage,
late week rainfall amounts will be on the light side ranging
from around 0.50 inch in the NW Alleghenies to 0.10 inch in the
Lower Susquehanna Valley.

Gusty winds up to 40 mph are forecast on the backside of the
deep low and will deliver much colder air spilling downwind of
the Great Lakes this weekend. This pattern will be favorable
for lake effect rain and possibly snow showers later Friday
into early Saturday over the higher elevations. NBM data even
suggests a minor snow accum (<0.5 inch) is possible in the NW
mtns and highest ridgetops/summits in the Laurel Highlands.

KEY MESSAGE 3: Frost and freeze conditions this weekend

Freezing temperatures and frosty conditions are forecast into
and over the weekend. Friday night will be a wind driven freeze
likely confined over the NW mtns; Saturday and Sunday nights
look more conducive for a traditional  radiational cooling
frost/freeze setup. Aside from being on the chilly side of mid
October climo, the upcoming weekend will be fair and dry.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Areas of fog and low stratus are likely to develop tonight, with
one area of focus stretching from the Laurels into the northwest
mountain, and the river valleys of east-central and especially
northeastern PA being another area of focus. We continued to
trend more pessimistic than the GLAMP in terms of vsby, leaning
towards the more pessimistic HREF/REFS guidance as low clouds
scatter out and low-level moisture lingers from yesterday`s
rainfall. On the other hand, downsloping may keep KAOO and KJST
free of fog and low stratus concerns, as indicated by the
GLAMP/HREF/REFS and RAP sounding.

Overnight fog and low stratus will have mixed out regionwide by
13-15Z Tuesday, when S-SW flow will pick up to around 10-15 kts
ahead of a progressive low pressure system sliding across the
Great Lakes. A few showers may move across the Northern Tier
(KBFD) during the morning and afternoon as the system passes to
our north, but prob is too low to include in the TAFs.
Otherwise, little to no precipitation is expected across our
area, as supported by upper-level suppression under the right-
exit region of a jet streak. This jet streak will likely
introduce LLWS concerns across the airspace between 00Z and 06Z
Wednesday. This low level shear will persist through the
overnight hours tomorrow until the exit region of the jet has
lifted northeast.

Outlook...

Wed...Restrictions from low ceilings and -SHRA possible as the
front moves southward across the Commonwealth.

Thu...A period of VFR is favored behind the front, with a chance
for restrictions and -RA later on Thursday as the front
oscillates back northward.

Fri...Scattered -SHRA and isolated -TSRA could bring
restrictions across the region with cold FROPA. W-NW winds may
gust up to around 25-35 kts behind the front.

Sat...Localized restrictions possible early due to post-frontal
stratocumulus and lake-effect -SHRA/-SHSN, primarily across the
Northern Tier. Otherwise, VFR prevailing with NW-NNW wind gusts
up to around 25-35 kts possible regionwide.

&&

.CLIMATE...
Daily record high temperatures for October 13th and 14th:

MDT 85/1954 | 85/1975
IPT 83/1954 | 84/1975
AOO 82/2024 | 80/2021
BFD 78/1969 | 79/1975
STC 82/1930 | 84/1897

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

WHAT HAS CHANGED...Steinbugl
KEY MESSAGES...Steinbugl
DISCUSSION...Steinbugl
AVIATION...Colbert/Bowen
CLIMATE...Steinbugl