268
FXUS61 KCTP 231551
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1051 AM EST Sun Feb 23 2025

.SYNOPSIS...
A relatively zonal flow is expected through the middle of the
week, with a weak cold front moving across the region late
Tuesday. A deepening upper level trough is expected over the
region by late week, preceded by the passage of a stronger cold
front Thursday. Temperatures will average above normal for much
of the week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Late morning update.

Some mid level clouds across far northern PA. Expect a bit
better mixing today and temperatures started off a little
warmer today, so did edge temperatures up a small amt into
the mid afternoon hours.

Earlier discussion below.

Surface ridging will ensure fair and seasonable weather today
across Central PA. Warm advection aloft ahead of an upstream
shortwave over the Grt Lks will spread increasing high clouds
into the region this afternoon, especially over the N Mtns.
Model soundings become mixed this afternoon to 900mb, where
temps around -4C/-5C support highs ranging from the mid 30s
over the Alleghenies, to the mid 40s in the Lower Susq Valley.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
A fairly potent upstream shortwave is progged to track across PA
this evening. Lack of moisture should limit its effects to a
period of overcast skies and perhaps a flurry over most of
Central PA. However, would`t rule out quick dusting over the NW
Mtns, where ensemble guidance supports POPs of around 15pct, due
to orographic lift in southwest flow. Breaking clouds are
expected late tonight, as large scale subsidence arrives behind
the exiting shortwave.

Guidance continues to support fair and generally dry weather
early next week associated with a zonal flow pattern with
fast-moving, moisture-starved shortwaves. One such shortwave is
progged to pass well north of PA Monday PM, bringing an increase
in cloud cover during the afternoon/evening, but probably no
precipitation. A second shortwave and weak associated cold front
is progged to pass over PA Tuesday, bringing a decent chance of
light rain showers, especially over the N Mtns. Ensemble mean
qpf Tuesday is generally <0.05 inches.

A broad southwest flow between high pressure off of the East
Coast and a dying cold front over the N Grt Lks will flood the
region with mild air into mid week. GEFS 2m temp anomalies rise
5-10 degrees above average, translating to highs in the 40s to
low 50s and lows Monday night in the 30s.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
Current ensemble guidance continues to highlight a progressive
pattern for the end of this week and into the weekend. A series
of upper-level troughs are expected to swing across central PA
between Wednesday night through Saturday. Temperatures will
remain mostly seasonal during this period with afternoon highs
relatively mild and overnight lows right around the freezing
mark for southern PA and in the mid to upper 20s across the
north.

The first system will arrive Wednesday night into Thursday
morning. A surface low will pass over the great lakes ahead of a
lagging 500mb trough. We are expected to stay predominately
above freezing with 850 temperature anomalies expected to be
+8-12C Thursday. Thus mainly rain showers are expected for us
ahead of and along the warm front as we will remain in the warm
sector. A few scattered snow flakes are possible across the
northwest as temps fall behind the surface low.

Friday will remain relatively dry as surface high pressure
builds in before the next shortwave through pushes down from
central Canada on Saturday. A reinforcing shot of cold air
associated with this system will allow for precipitation to be
more of a wintry mix with rain and snow possible Saturday into
Sunday. High pressure will build in on Sunday, but winter will
make a return as temperatures will remain well below normal for
the beginning of next week.

&&

.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
Late morning update.

Mid level clouds over the far north this morning, with the
leading edge of the lower clouds edging into BFD. Otherwise
VFR conditions this afternoon with just some high clouds.

Earlier discussion below.

Mainly clear skies and relatively light wind covered most of
Central PA this morning. The southern edge of a large area of
high-based stratocu and altocu clouds extended across the
Northern Tier Counties of PA.

Dry and relatively tranquil weather with good/VFR flying
conditions will occur for the bulk of the region today and
tonight with variable amounts of mainly mid and high level
clouds (Altocumulus and Cirrus). The exception will be across
the NW Mtns (KBFD) where a mean westerly flow in the lowest
several KFT AGL will bring occasional MVFR CIGS through today
and into tonight before a warm front lifts north across the
Commonwealth late tonight and leads to higher cloud bases and a
mean SWRLY flow in the SFC-5 KFT AGL layer.

Mainly VFR will occur tonight, though MVFR Cigs with a few
flurries or a brief snow shower (VFR to Brief MVFR VSBYS) will
occur at KBFD, with borderline MVFR/VFR CIGS likely as far
south as KIPT from 03Z Monday on.

For late Monday morning into at least early Monday night (Just
beyond the end of this 12Z TAF period), a strong SWRLY Low Level
Jet will move SE from the Glakes Region and impact the
airfields across mainly the NW half of PA with a rather lengthy
period (i.e., GRTN 10 hours) of Low Level Wind Shear.

Outlook...

Mon...Mainly VFR. Brief MVFR (NW). LLWS likely at KBFD late
Monday morning into Monday night. The primary period of LLWS at
KIPT, KUNV and KJST would be Monday afternoon into Monday night.
More Marginal LLWS at KMDT and KLNS from about 00Z-06Z Tuesday.

Mon Night and Tue...Rain showers (and some snow showers
across the highest terrain) will become numerous across the NW
Mtns Tuesday, but remain isolated to scattered over the The
Middle and Lower Susq Valley

Wed...VFR/no sig wx.

Thu...Chance of rain associated with a cold front.

&&

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

&&

$$

SYNOPSIS...Fitzgerald/Martin
NEAR TERM...Fitzgerald/Martin
SHORT TERM...Fitzgerald
LONG TERM...Bowen
AVIATION...Lambert/Martin