York, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

851
FXUS61 KCTP 021107
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
707 AM EDT Wed Apr 2 2025

.SYNOPSIS...
A warm front will lift into Pennsylvania through tonight as low
pressure tracks west of Pennsylvania through the Great Lakes
through tonight. A trailing cold front will push through Central
Pennsylvania late Thursday, then stall out out of just south of
the region late this week. A wave on the stalled front is
likely to lift up the Ohio Valley and across Pennsylvania next
weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Mostly clear and chilly conditions to start the day early this
morning with mid and high clouds starting to increase from the
west. Daybreak readings ranging from the mid 20s in the valleys
of North Central PA, to the mid 30s in the more urbanized spots
of the Lower Susq Valley.

Mid and high clouds will continue to increase through mid
morning. Isentropic lift at the nose of a strong southerly low
level jet ahead of a warm front lifting into the Grt Lks will
likely produce a round of showers across much of Central PA Wed
afternoon/early evening. The strongest forcing and highest POPs
of around 90 pct are across the NW Mtns, while the Lower Susq
Valley stands the least chance of measurable rain. Most likely
timing for showers remains from mid afternoon over the NW Mtns,
to early evening over the eastern edge of the forecast area.
Mostly cloudy skies and am east- southeast llvl flow off of the
chilly Atlantic Ocean should result in max temps Wed a bit below
normal for early April.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
Showers are expected to lift north of the PA/NY border by late
Wed evening along with the 8H baroclinic zone. Focus then
shifts to an upstream cold front and associated line of
convection, which should push into at least the northwest part
of the forecast area by dawn Thursday. Current progs still
indicate minimal surface based instability, but strong bulk
shear is evident with 70kt winds at 850mb supporting a MRGL
outlook from SPC for damaging wind gusts toward dawn Thursday
over the Allegheny Plateau.

Uncertainty persists Thursday in the amount of instability, with
CAMS indicating dampening early Thursday and perhaps more robust
MUCAPEs lifting into the Lower Susq later Thu aftn/evening. At
this time the area is outlooked under MRGL/SLGT outlooks, and
will message the potential for strong winds gusts while uncertainty
in instability is also high. The best chance of organized strong
storms capable of damaging winds is across the Lower Susq
Valley, where a late day surge of moderate instability (CAPE
near 1000J/kg) is progged in conjunction with deep layer shear
of around 40kts.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
The cold front stalls out just south of PA Thursday night. A
wave on this boundary looks increasingly likely to result in a
period of rain Thursday night into early Friday, especially
across Northern PA.

Latest EPS/GEFS suggests a brief period of cool and drier
weather is likely Friday/Friday night associated with a surface
high passing north of PA. However, medium range guidance
indicates another wave of low pressure riding along the stalled
front will result in a rainy weekend. Latest ensemble mean qpf
between Thu night and Sun PM ranges from 1 to 2.5 inches over
Central PA, with the highest totals focused over the NW Mtns
and the least across the Lower Susq Valley. The southeastern
part of central PA has been under moderate to severe drought
conditions for quite some time, so any rain over that part of
the state would be beneficial.

There is broad consensus among medium range guidance that upper
troughing builds over the region early next week, accompanied by
below normal temperatures and scattered rain/snow showers over
the Allegheny Plateau. Below average temps are favored for much
of next week, which could raise some frost/freeze concerns as
the spring growing season gets underway.

&&

.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions prevailing around sunrise will continue through
mid morning as mid and high clouds increase from the west ahead
of an approaching warm front. Winds will remain light into the
first half of the morning before gusts of 20 to 30 knots become
likely. A band of showers is expected to develop during the
afternoon/evening, with BFD most likely to see rain. All other
sites have around a 30% chance or less of seeing measurable
rainfall. Any airfields that do see showers may have brief
periods of MVFR cigs/vsby. A few rumbles of thunder will also be
possible over northwest PA with weak instability shown in most
models.

As showers move out of the region, most guidance indicates that
south-southeasterly flow will lead to increasing low-level
moisture over much of Central PA. This will cause MVFR ceilings
to develop almost everywhere Wednesday night, with the potential
exception of JST. RAP model soundings suggest that the low
clouds would make it there, but the GLAMP and HREF show a less
than 40% chance of MVFR ceilings developing.

The other concern into Wednesday night will be LLWS as a 45 to
55 knot low-level jet moves in and surface wind gusts decrease.
BFD will be the first airfield to see wind shear develop and the
threat will spread southeastward through the late evening. The
potential for LLWS will reach MDT and LNS in the 06-08Z
timeframe.

Outlook...

Thu...MVFR poss in widespread rain showers. TSRA poss, mainly S.
CFROPA aftn/eve.

Fri...MVFR cigs and visby expected, mainly S.

Sat...Widespread showers; impacts likely.

Sun...Widespread showers; impacts likely.

&&

.CLIMATE...
Closing out very mild March 2025. Below are the rankings and
departures from the historical average through 3/30:

Site                Avg. March temp               Rank
Harrisburg            46.5F (+4.9F)               12th warmest
Williamsport          44.8F (+6.2F)                9th warmest
Altoona               44.4F (+5.9F)                7th warmest
Bradford              40.2F (+7.3F)               T3rd warmest

State College COOP site STCP1 recorded the 10th warmest March on
record with an average monthly temperature of 43.3F.

&&

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

&&

$$

SYNOPSIS...DeVoir/Fitzgerald
NEAR TERM...DeVoir/Fitzgerald
SHORT TERM...DeVoir/Fitzgerald
LONG TERM...Fitzgerald
AVIATION...DeVoir/Bauco
CLIMATE...Steinbugl