911
FXUS61 KCTP 180914
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
514 AM EDT Sat Oct 18 2025

.SYNOPSIS...
* Increasing clouds with light rain showers or sprinkles
  tonight into early Saturday morning over north central PA
* Clouds break for p.m. sun with noticeably milder temperatures
  to start the weekend
* The weekend ends wet/windy with gusty rain showers Sunday
  afternoon-Sunday night; trending breezy/cooler into Monday

&&

.NEAR TERM /THROUGH TONIGHT/...
Increasing deep layer warm advection and associated weak
isentropic lift was leading to fairly extensive altocu and
high-based stratocu across the bulk of the CWA early this
morning. Isolated to scattered, brief and light rain showers
were drifting ESE across mainly the northern half of PA, with
most of them not heavy enough or lasting long enough to do much
more than dampen the ground with 0.01-003 of an inch. The higher
end amounts mentioned here will occur almost exclusively near
the PA/ NY border.

By 16-18Z today, thicker cirrus, then altocu clouds will drift
to the Susq Valley and points east as small scale and
relatively flat ridging moves over the Commonwealth and a region
of subtle descent beneath the thermally indirect, right exit
region of a 300-500 mb jet moves NE from the Ohio Valley.

Temps will start today +10 to +15 degrees higher than Friday
morning - in the mid 40s to around 50F.

Increasing southerly flow today will create weak llvl temp
advection and combine with the sunshine and mild start to
boost max temps +7-15F higher vs. Friday into the mid 60s to low
70s respectively, from east to west across the CWA. These temps
will be (+10-15F above climo along the Allegheny Plateau and
Laurel Highlands).

Look for variable amounts of mainly mid and high clouds
tonight, with similar to slightly milder overnight lows compared
to early Sat morning.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
Amplifying 500mb trough will take on a negative tilt as it
lifts through the Great Lakes/Ohio Valley into the Northeast on
Sunday. A deepening a surface low (sub-1000mb) associated with
the upper trough will track through Michigan into eastern Canada
toward James Bay. Strong southerly flow ahead of the low will
transport Gulf moisture northward and support a modestly moist
air mass into PA. A cold front trailing the seasonably strong
sfc low is expected to sweep eastward and serve as a focus for
one or more lines/bands of gusty rain showers (shallow
convective frontal rain bands) Sunday afternoon through the
first part of Sunday night.

The setup is a common transition season low CAPE/high shear
environment with potential for strong to locally damaging wind
gusts along the convective lines/frontal bands. Periods of heavy
rain are also possible, but given the progressive forward
motion, we feel that that flooding risk is pretty low or on the
nuisance side (drought conditions also a contributing factor).
Primary risk would be in urban or residential areas particularly
where leaves clog storm drains. In fact, WPC trimmed back the
MRGL risk for Excessive Rain to the Western Mtns and Northern
Tier of PA in our CWA, but SPC expanded the MRGL SVR risk area
slightly more to the east to encompass all of CTP`s CWA.

A tight pressure gradient and 3-6mb fall/rise couplet indicates
gusty winds will continue behind the cold front as the llvl
flow turns to the west. We adjusted NBM wind gusts higher to max
out in the 30-40 mph range or below wind advisory criteria for
now. This will be the first "windy" period this Fall with the
potential to blow leaves and unsecured objects (Halloween
decorations) around.

Max temps top-out in the 65-75F range in most areas on Sunday
with some locations possibly approaching 80F in the LSV. Expect
a steady drop in temps across the western Alleghenies Sunday
night with low temps -10F colder vs. Saturday night.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Breezy and cooler to start next week with rain showers exiting
the area Monday night. Wind gusts in the 25-35 mph range are
forecast during the day on Monday and will amplify the 24hr
cool down/maxT change of -10 to -20 degrees vs. Sunday.

After a brief dry period Monday night into Tuesday, the
remainder of next week looks unsettled and quite showery
(especially downwind of Lake Erie over NW PA and the western
Alleghenies) under the influence of large scale upper level
troughing and broad cyclonic flow. It`s conceivable that the
the first flakes of the season may be found over the higher
elevations along the Allegheny Front. I guess it`s that time of
year...

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
A shield of mid and high clouds crossing the Great Lakes will
continue to move over the airspace overnight. Ultimately an
overcast deck near 10,000ft AGL is anticipated over much of the
region by sunrise Saturday. However, there is high confidence
(>90%) in no restrictions to flight categories due to the
increasing clouds. VFR conditions should prevail throughout this
TAF package. Surface winds will be generally calm overnight as
well.

The only area that could see some concern would be over northwestern
PA near BFD. Scattered rain will likely develop off the coast
of Lake Erie late tonight, and a PROB30 group has been included
with BFD`s TAF to reflect the isolated chance of rain over that
airfield.

Outlook...

Sat...VFR. A few showers possible over northwest PA.

Sun-Mon...Restrictions possible in SHRA. Low probability of a
thunderstorm over northwest PA.

Tue-Wed...Scattered showers possible.

&&

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

&&

$$

SYNOPSIS...Lambert/Steinbugl
NEAR TERM...Lambert/Steinbugl
SHORT TERM...Lambert/Steinbugl
LONG TERM...Steinbugl
AVIATION...Gartner/Tyburski