-- Discussion containing changed information from previous version are highlighted. --
047
FXUS61 KCTP 130242
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
1042 PM EDT Wed Jun 12 2024

.SYNOPSIS...
A seasonable night with clear skies and calm winds will give way
to above average temperatures on Thursday as southwest winds
west of high pressure drifting off the Mid Atlantic Coast usher
in milder conditions.

A cold frontal passage on Friday will spark a round or two of
showers and scattered thunderstorms, some of which could produce
gusty winds, frequent lightning and hail.

After a dry and warm weekend, a ridge of high pressure will
bring an increased risk of excessive heat early next week with
highs in the 80s and 90s and heat index values possibly
exceeding 100F.

&&

.NEAR TERM /THROUGH THURSDAY/...
A very pleasant night is underway with low dewpoints and
seasonable temperatures. Skies are clear for most and should
stay that way through Thursday morning for most save a few
cirrus clouds streaming in overhead. Great viewing of the waxing
crescent moon, which will set during the 1 o clock hour
overnight. Tonight will be tranquil and comfortably cool with
min temps near 50F in the perennial cold spots across the
Northern Mtns and Laurel Highlands and mid to upper 50s
elsewhere.

As high pressure drifts east of the Commonwealth on Thursday,
winds will shift to come out of the southwest and could be a bit
gusty at times, especially in the northern tier. Winds coming
from the southwest mean an increase in temperatures and
moisture. Mostly sunny skies are expected as high temperatures
reach the 80s areawide. Another comfortable day is expected for
most, but dewpoints will likely crest the 60F mark in the Lower
Susquehanna Valley, making it feel noticeably (but not
aggressively) humid.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
An approaching cold front will bring a chance of showers and
thunderstorms to the northern Alleghenies as early as Thursday
night, and then drop south across central PA during the day Fri
with more numerous showers and thunderstorms. There is still
uncertainty with the timing of this precip and associated
clouds, which will influence how high temps can rise across
south central PA. Latest hires guidance has precip holding off
until at least late afternoon in the southeast, allowing temps
to first rise into the upper 80s to low 90s. Most places will
see rainfall totals between 0.20 and 0.50 inch on Fri, with
locally higher amounts possible in heavier downpours.

SPC`s Day 3 outlook paints a MRGL risk for SVR TSRA across much
of Central PA, while a SLGT Risk covers a small portion of our
Eastern zones (the Western Poconos, south through the greater
Harrisburg, Lebanon and Lancaster areas).

Despite forecast high temps near 90 across southern zones Thu-
Fri, relatively low levels of humidity (dewpoints 55-65F) will
hold the heat index to just a couple deg above the air temp.
Thus not anticipating heat products at this time. However, the
+15-20 degree swing from temps well below normal early this
week to the warm weather late this week is noteworthy.

After the cold front exits southeast PA on Friday evening,
dewpoints and temperatures will fall quite nicely overnight as
skies clear out and lows end up in the 50-60F range by Saturday
morning. High pressure will result in sunny skies, temperatures
right around average, and conditions quite similar to today
(Wednesday) - refreshing to spend time outside! The center of
high pressure will pass overhead Saturday night and
temperatures will drop into the 40s and 50s by Sunday morning.
This will be the last time we see temperatures in the 40s in PA
for the foreseeable future.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Dry conditions are expected to prevail through Tuesday
afternoon outside of some isolated diurnally driven showers
across the northern tier Monday afternoon and across much of
north and western PA Tuesday afternoon.

An extended period of above average temperatures is
increasingly likely as a large ridge builds across the eastern
US. This will allow for MaxTs and MinTs +10-15F above
climatology for the middle of June. There remains some model
difference with respect to the strength of the ridge, but
generally better agreement of abnormally warm temperatures
extending northward into PA.

Less humid conditions on Monday will bring heat index values
into the upper 90s, with some locations across southern PA
pushing close to the 100F mark. Humidity during the afternoon
hours will increase the risk for excessive heat on Tuesday with
some potential for heat index values in the 100-105F across the
Lower Susquehanna Valley. Humid conditions will continue into
Wednesday with heat index values slightly lower than Tuesday,
but still anomalously warm even for this time of the year. The
Climate Prediction Center has placed much of eastern PA in a
Moderate Risk for Excessive Heat for the middle and end of next
week, outlining the longevity of heat across the region.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
Late evening update.

Current fcst in good shape.

Earlier discussion below.

Not really any change for the 00Z package.

Abnormally dry airmass in place has resulted in a layer of
high base CU today.

Not expecting fog or low clouds tonight, given the dry
airmass in place.

Winds remain rather light on Thursday, for the first warm
day in a while.

A chance of showers and storms on Friday with a cold front.
Timing of the system and the lack of real high dewpoints may
limit the coverage and intensity of the showers and storms.
Activity quickly clears out late Friday.

A dry weekend shaping up with VFR conditions.

Perhaps a shower or storm late Monday, as a warmer airmass
is advected eastward toward PA.

Outlook...

Fri...Restrictions possible in CB/TSRA.

Sat-Sun...Predominantly VFR.

Mon...Mainly VFR, chance of convection mainly northwest.
-- End Changed Discussion --

&&

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

&&

$$

SYNOPSIS...Banghoff/Colbert
NEAR TERM...Banghoff
SHORT TERM...Lambert/Colbert
LONG TERM...Banghoff/NPB
AVIATION...Martin