-- Discussion containing changed information from previous version are highlighted. --
962
FXUS61 KCTP 302334
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
734 PM EDT Tue Apr 30 2024

.SYNOPSIS...
-Showers give way to clearing skies and some patchy fog tonight
-Warm/dry weather with lower humidity Wednesday-Thursday
-Trending unsettled into the weekend with rain likely Sat/Sun

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
All lightning activity has shifted east of the area this evening
with only stratiform rain showers ongoing along the I-80
corridor and into northeast PA. Overcast conditions and a lack
of vertical wind shear have keep showers in check for most of
the afternoon. Hi-resolution guidance indicates a few showers
could move into the Lower Susquehanna Valley this evening and
eat up what is left of the instability resulting from
temperatures in the low to mid 80s. Have left a mention of
isolated thunder over the next few hours.

Clearing skies are already working their way into western PA as
of 7PM as the cirrus deck associated with today`s weather system
continues to pull north and east of the region. Light winds and
clear skies could result in some patchy fog overnight thanks to
a moisture-rich airmass with dewpoints in the upper 50s. Best
chance for fog appears to be in the Laurel Highlands into
Clearfield County where dewpoint depressions are the smallest
and clearing will be most durable. Also can`t rule out some
valley fog in the deepest valleys of the northern tier that have
the best chance of decoupling, but the influx of drier air and
lower dewpoints may be a limiting factor.

Lows by Wednesday morning will range from the the middle 40s in
northwest PA to near 60 in the southeast where clouds will be
slow to clear overnight.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
Latest guidance continues to indicate warm/dry conditions
through midweek with a trend toward unsettled weather into the
weekend.

Dry air entrainment/mixing heights combined with mostly sunny
skies and mean westerly flow all signal to cut dewpoints and
raise temps by a few degrees in-kind for both afternoons.

The sfc pattern by Friday begins to take on a CAD configuration
as high pressure channels down the eastside of the Appalachians.
Can`t rule out a late-day PM shower or t-storm across the
western Alleghenies with POPs increasing from west to east
Friday night into Saturday morning. Cloud trends and southeast
flow could result in a considerable west/east temp gradient
with max temp spread between 80-65F across central PA. Further
adjustments to Friday high temp fcst likely over the next few
cycles. This setup could also favor low clouds and fog into the
middle and lower Susquehanna Valley Friday night into AM Sat.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
High pressure tracking north of PA into the Canadian Maritimes
will likely result in a developing easterly flow and the onset
of cooler conditions Friday PM into the weekend. All medium
range guidance points to a rainy and cool weekend, especially
the first half, as a southerly low level jet linked to an upper
trough over the Great Lakes and an associated plume of deep
moisture overruns a stationary front over the Ohio Valley.
Latest EPS plumes indicate around a half inch of rain is likely
by late Sunday.

Passage of the upper trough and associated occluded front
appears likely to bring drier and warmer conditions by Monday of
next week. A warm front arriving Tuesday could signal a return
of clouds and showers/tstorms to the region.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
A cold front is crossing central PA this evening, accompanied
by scattered rain showers. There is an outside chc of a
thunderstorm through mid-evening across the Lower Susq Valley
(MDT, LNS).

Lingering showers could persist through the early overnight
hours across the Lower Susq Valley, with drying elsewhere.
There could be some reduced cigs over the western highlands
(BFD, JST) this evening, but skies are expected to gradually
clear after that. As skies clear from west to east and winds
diminish overnight, we will have to watch for fog formation
during the pre-dawn hours.

Expect quick improvement areawide Wed morning, as any lingering
fog dissipates and leaves mostly sunny skies with a W/NW sfc
breeze of 5-10 kts.

Outlook...

Thu-Fri AM...No sig wx expected.

Fri PM-Sat...Scattered SHRA/TSRA developing from west to east w/
reductions possible.

Sat night-Sun...Widespread SHRA/TSRA expected.
-- End Changed Discussion --

&&

.CLIMATE...
Record high temperatures were set at the following locations
on Monday:

SITE        2024 OBS     PRVS RECORD
Altoona          86F     83F (1956)
Bradford         82F     76F (1984)
Williamsport     89F     86F (1942/1974)

It was also the first 80F day in Bradford so far this year,
almost 2 weeks ahead of the average first 80F temperature (May
11th).

&&

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

&&

$$

SYNOPSIS...Banghoff
NEAR TERM...Banghoff
SHORT TERM...Steinbugl/Banghoff
LONG TERM...Fitzgerald/Gartner
AVIATION...Evanego
CLIMATE...Banghoff/Colbert