022
FXUS61 KCTP 121010
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
610 AM EDT Tue May 12 2026

.WHAT HAS CHANGED...
* Only minor tweaks to the going forecast

&&

.KEY MESSAGES...
1) Freeze and frost conditions early today could kill crops and
other sensitive vegetation tonight into early Tuesday morning.

2) Cool/Wet weather will develop for late tonight/early
Wednesday and continue through Wednesday night with rainfall
amounts averaging 2 to 4 tenths of an inch.

3) Early May chilly pattern for Thursday and Friday will break
down this weekend triggering a significant summerlike warmup
into next week.

&&

.DISCUSSION...
KEY MESSAGE 1: Freeze and frost conditions early today could
kill crops and other sensitive vegetation tonight into early
Tuesday morning.

Temps/dewpoints/sky/wind are on track with only minor tweaks
to the next couple of hours for the latest trends. Still
looking at a very frosty morning.

Latest RAP guidance clearly shows a tight SW/NE (and nearly
stationary) theta-E gradient within the 925 to 850 layer across
SW PA with decent convergence along it. This is leading to some
pesky/persistent mid-level cloud cover over southwest PA that
could hinder frost/freeze in parts of the Laurel Highlands
(specifically Somerset County), but with any breaks of clearing
and higher elevation there should be sufficient to allow temps
to fall into the low-mid 30s.

This moderately tight, low-mid-level theta-E gradient will
advance NE across the CWA as we progress through this
afternoon.

Mid morning through early afternoon mostly sunny skies (with
some scattered high based strato cu and/or altocu will be
followed by a thickening layer mid and high clouds later this
afternoon and evening with periods of rain/showers moving in
late tonight and lasting into Wednesday evening.


KEY MESSAGE 2: Cool/Wet weather will develop for late tonight/early
Wednesday and continue through Wednesday night with rainfall
amounts averaging 2 to 4 tenths of an inch.

A seasonably strong upper level trough will carve out over
Great Lakes Tue-Thu and eventually close off over New England
by the end of the week. The upper trough and its associated sfc
low and trailing cold front will bring wet weather to CPA for
midweek with periods of rain/showers and perhaps a few t-storms.


Look for steadier light rain Tuesday night-Wednesday to become
more showery by Thursday before conditions start to dry out
Thursday night- Friday.

NBM fcst temps (Thursday) may end up being notably cooler as GFS
and NAM show Wet Bulb zero levels AOB 2000 FT AGL (across the
Northern and Western Mtns) - which mean that any rain showers
there could be mixed with or even fall as snow showers at
elevations AOA 1800 FT MSL. Later forecasts should continue to
weight fcsts (by perhaps 75 pct) twd NBM25 PCT to capture the
anticipated colder temps based on the aforementioned readings
aloft and very low wet bulb zero levels for mid May.

KEY MESSAGE 3: Early May chilly pattern for Thursday and Friday
will break down this weekend triggering a significant
summerlike warmup into next week.

Guidance signals a significant warmup on the horizon as the
upper level trough ejects eastward into the northern Atlantic
and mean jet stream flow lifts northward. This large scale
pattern shift should deliver a significant warm surge into the
back half (2H) of May with summerlike temperatures forecast by
early next week. There is even some potential heatrisk
considerations (after a rather cool stretch) with current max
temps in the 80-90F range on Monday. Rainfall should remain
light/limited with low chances for sct showers or isolated
t-storms.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
Nice clear morning with an orange sky at sunrise. Main change
was to add a group to the current 06Z TAF set.

More information below.

High pressure will keep dry weather with VFR conditions through
06Z Wed.

Strong warm advection could result in a shower at BFD toward
06Z Wed, but the airmass is quite dry, so left showers out
of the BFD TAF.

Main chance for showers will be during the day on Wednesday.
A cold front will move into the area later in the day on
Wed. A coastal low forming will keep colder, breezy, and
times wet conditions into early Friday morning.

Outlook...

Wed...Restrictions likely with showers and PM thunderstorms.
South winds shift to westerly behind a cold front.

Thu...Lingering clouds and showers with restrictions north/west
and improvement southeast.

Fri...VFR likely.

Sat...At least brief restrictions may develop by afternoon, with
potential scattered shower activity.

&&

.CLIMATE...
State College COOP (STCP1) recorded the 20th coldest first 10
days of May going back to 1893 (133 years). The average
temperature was 51.1 degrees and tied 1995 and 1893 as the 20th
coldest on record.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Freeze Warning until 8 AM EDT this morning for PAZ004>006-
010>012-017-018-024-033-037-041-042.
Frost Advisory until 8 AM EDT this morning for PAZ019-025>028-
034-035-045-046-049>053-058.

&&

$$

WHAT HAS CHANGED...Lambert/Dangelo/Steinbugl
KEY MESSAGES...Lambert/Steinbugl
DISCUSSION...Lambert/Dangelo/Steinbugl
AVIATION...Martin
CLIMATE...Steinbugl