Latest Area Forecast Discussion for Central PA

Here is the latest Area Forecast Discussion for Central PA

This text statement is the latest forecast reasoning from the NWS in State College, PA

See the links at the bottom of the page for previous issuances/versions of the statement as well as our other text statements.

378
FXUS61 KCTP 011024
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
624 AM EDT Thu May 1 2025

.SYNOPSIS...
* Scattered to numerous thunderstorms with localized
gusty/potentially damaging winds and heavy downpours expected
across the Western third to half of Central PA this afternoon
into early tonight.

* Periods of showers and isolated afternoon and evening
thunderstorms on Friday will be followed by growing
confidence in an increasingly wet pattern through the first
week of May

&&

.NEAR TERM /THROUGH TONIGHT/...
Mainly clear skies with areas of cirrus clouds will cover the
region through much of the morning today.

Min temps around sunrise will vary from the mid 30s across the
high terrain of Sullivan County in the Northeast to the mid 50s
and upper 50s on the ridge tops in Southern PA.

The main weather feature today will come in the form of a warm
front currently located across the far SW corner of PA.

This boundary divided sfc dewpoints in the 30s across the
Northern half of PA from the mid and upper 50s across West VA.

The warm front will lift north and buckle to a more north/south
orientation extending from near KERI to KFIG and KAOO later this
afternoon and early this evening.

0-1KM storm relative helicity will be AOA 200 m2/s2 along and to
the east of this boundary, which will just nudge to the east
(over the Central Mtns) by around midnight before heading across
the Ncent Mtns and Susq Valley late tonight.

A southwesterly mid-level jet of 45 and 55 kts respectively at
700 and 500 mb will move over this llvl warm front late this
afternoon and evening, providing the necessary large scale lift
and shear needed to form periods of showers and scattered to
numerous strong to potentially severe TSRA across the Western
1/3 of PA (and at least as far east as the RT 219/I-99 corridor)
this afternoon and evening (at the eastern edge of 750-1000 j/kg
MU CAPE via the latest HREF) .

Significant MU CAPE will be lacking across the NE half of the
CWA later today and tonight, but the "sweet spot" for
organized/rotating and potentially training TSRA (with locally
heavy rain and the potential for isolated weak tornadoes in
some supercells) will be near and just to the east of the
aforementioned slow-moving warm front with the HREF`s 4 hour max
2-5 KM updraft helicity exceeding 150 m2/s2 in select storms.
The storms moving NE over this llvl boundary will need to be
monitored closely, especially early this evening when DCAPE will
decrease and LCLs likely lowering well below 1 KM AGL
immediately on the cool side of the front.

SPC covers our NW zones with a DY 1 SLGT risk with a MRGL
extending from the RT 219/I-99 corridor in SW PA to the RT 15
corridor near the PA/NY border.

High temps today will range from near 70F across the NE mtns to
around 80F in the southern Valleys.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
The area will be between frontal waves later tonight into friday
with with some passing showers through Friday night and isolated
afternoon and evening TSRA.

Temps will peak tonight and Friday with the largest departures
from climo (+15-25F) on low temps for the first night of May.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Confidence in a wetter than not period for the long range is
building. PoPs generally rising across the board for the entire
long range period. Many 60 PoPs in the Sun-Tues time frame, and
30-40s thru Day8. Seems reasonable. Repeated rainfall won`t be
unwelcome, especially by those in the SE where they have been
in drought status for quite a while. No deviations from NBM are
necessary at this point.

The latest guidance continues to signal a wet pattern setting
up this weekend which appears to continue into next week. The
next frontal wave drives widespread rain on Saturday before
slowing down as the upper trough cuts off and forms a closed low
in the Ohio Valley. The 500mb cut off low meanders over the
Ohio Valley into early next week then slowly drifts to the east
by the end of the period. There is still some uncertainty on how
the pattern will evolve, but the key takeaway is a bullish
trend for largely beneficial rainfall with 7-day WPC QPF
printing 1-2+ inches over most of central PA.

&&

.AVIATION /10Z THURSDAY THROUGH MONDAY/...
For most of the day, expect VFR conditions with mid level
clouds.

Toward late afternoon across the west, a chance of showers
and storms. Have used a TEMPO group for this. Activity forms
with afternoon heating and the increase in moisture.

The activity should weaken later this evening, as the
activity moves to the northast of the more unstable air.

The increase in moisture will result in lower CIGS later
tonight.

With the higher moisture as well, there will be a daily
chance of showers and perhaps a storm into the upcoming
weekend. Also patchy fog at night as well.

Earlier discussion below.

Showers and storms will push eastward through the evening,
though the threat for thunder will rapidly drop off as the
showers enter a much more stable environment from east of AOO
and UNV.

Fri...Scattered showers with some restrictions possible.

Sat-Mon...Periods of rain and sub-VFR conditions likely.

&&

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

&&

$$

SYNOPSIS...Lambert
NEAR TERM...Lambert
SHORT TERM...Lambert/Steinbugl
LONG TERM...Dangelo/Steinbugl
AVIATION...Martin

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