-- Discussion containing changed information from previous version are highlighted. --
406
FXUS61 KCTP 191728
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
128 PM EDT Thu Sep 19 2024

.SYNOPSIS...
*Warmer today with a mix of clouds and sun followed by clearing
 and areas of fog tonight into early Friday morning
*Little to no rainfall expected through the weekend (September
 2024 one of the driest so far in parts of central PA)
*Daytime temperatures peak +5-10 degrees above average into
 Saturday before trending seasonably cooler next week

&&

.NEAR TERM /UNTIL 8 PM THIS EVENING/...
1015AM/1415Z: Visible satellite loop confirming sfc obs trend of
dissipating fog and improving visibility in the central valleys.
Expect a mix of clouds and sun for the remainder of today with
max temps warming up +5-10F vs. yesterday`s highs reaching the
mid 70s to lower 80s. Latest hires model consensus and 1-3hr NBM
potential precip index probabilities support a rain-free second
to last Thursday of the month.

Previous Discussion Issued: 507 AM EDT Thu Sep 19 2024

An elongated, north/south upper level trough stretching from the
Carolina Coast to Southern new England will support weak sfc low
pressure just southeast of Cape Cod. A BKN-OVC layer of
stratocu and altocu clouds covered most locations in Central PA,
and the bulk of the area will stay dry today.

Temps will start the day from the low 50s over the mountains
north of KIPT, to the low 60s across the Lower Susq Valley.

Anomalous -u component/easterly sfc-850 mb flow will back to the
northeast today and will advect drier air into the region from
upstate NY, gradually breaking up the dual layer of cloud cover
this afternoon. Aside from a small area containing some brief
showers moving West-Southwestward, expect rain-free conditions
over the CWA today.

The earliest/greatest amount of clearing should be over the
western half of the state this afternoon, while southerly
flow/waa aloft linked to a cut- off low over VA could result in
a lingering veil of cirrus over the eastern half of PA.

The return of sunshine should result in a marked jump in max
temps compared to today. GEFS 2m temp anomalies support highs in
the upper 70s to low 80s for most of the area.

&&

.SHORT TERM /8 PM THIS EVENING THROUGH SUNDAY/...
Surface ridging building over the region should result in
variable amounts of clouds tonight with patchy morning valley
fog a good bet across the Northern Half of PA both today and
Friday.

Latest global guidance tracks a weak shortwave just north of PA
late Saturday. This feature should have little moisture to work
with and the best forcing is progged to pass north of the
state. Therefore, keeping POPs just below 15pct for now over
most of the region. Max temps may be slightly lower Saturday,
due to low level flow veering to the east off of the Atlantic.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
-- Changed Discussion --
A trend toward cooler and cloudier weather appears likely into
the middle of next week associated with a cold air damming
scenario ahead of a slow moving warm front in the Ohio Valley
and high pressure over the Canadian Maritimes.

As for rainfall, a weak shortwave and associated plume of
enhanced pwats overrunning the warm front could produce
scattered showers Sunday night into early next week. Upsloping
flow could also yield patchy drizzle over the Central Mtns early
next week. The best chance for rainfall will come during the
middle of the week as an upstream trough approaches the region.
-- End Changed Discussion --

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
-- Changed Discussion --
VFR conditions with light winds and mainly clear skies are
expected through the rest of the day. Model soundings suggest
that fog will form once again overnight across the northern half
of Central Pennsylvania, with BFD, IPT, and UNV being most
likely to see IFR or lower visibilities. The HREF and GLAMP
suggest that fog could be possible (~30% chance) at sites
further to the south as well, but confidence is low. The fog
will dissipate by 14Z and give way to VFR conditions.

Outlook...

Sat-Sun...Valley fog in the morning; otherwise VFR/no sig wx.

Mon-Tue...Scattered showers.
-- End Changed Discussion --

&&

.CLIMATE...
The first day of Autumn 2024 (Fall Equinox) begins at 8:44 am
EDT on September 22nd.

&&

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

&&

$$

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