940
FXUS61 KCTP 181928
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
328 PM EDT Wed Sep 18 2024

.SYNOPSIS...
*Mostly cloudy tonight with pockets of light rain tapering off
 into Thursday
*Little to no rainfall expected Friday into early next week
 perpetuating one of the driest September`s so far on record
*Daytime temperatures peak +5-10 degrees above average Friday
 and Saturday before trending seasonably cooler next week

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
Precipitable water values have likely peaked across central PA
this afternoon. Expect an increasingly drier mean flow from the
north northeast to steadily lower deep layer moisture across
the region which will correspond to decreasing rain probs (from
north to south) and eventually cloud cover into Thursday. Lows
tonight will be in the 55-65F range with some potential for
radiational valley fog development into early Thursday morning
particularly in the northern tier where pockets of clearing are
most likely.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
The aforementioned mean northerly flow will continue to dry
things out into the weekend. However, a few bands of enhanced
mid-level FGEN forcing to the northwest the slowly departing
upper low/mean trough suggest holding on to a slight chance for
rain near and to the east of the I-81 corridor through Friday
night. Latest global guidance now suggest an isolated shower
cannot be ruled out on Saturday as another piece of shortwave
energy dives down the backside of the departing upper trough or
down the frontside of upper ridge building into the Ohio
Valley. On balance, expect a dry period for the majority of the
area with variable clouds and daytime highs +5-10F above the
historical average for mid/late September.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Much of the model guidance remains dry for Sunday, but the GFS
shows an outlier solution where a few showers ahead of a warm
front make it into west central PA. While model variability
remains elevated into next week, the ensemble means generally
favor weak upper troughing centered around the Great Lakes which
will support a marginal increase in rainfall/shower potential
along/ahead of an approaching front by next Monday or Tuesday.
Forecast max temps 75-80F peak +5-10F above mid/late September
climo to start the weekend and trend modestly cooler to 65-75F
(near the historical average) into early next week.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
Pockets of light rain will gradually diminish over the southern
half of the airspace through the evening. The highest confidence
and max probability of MVFR/IFR cigs will be around KJST/KAOO
prior to 19/00Z with VFR expected elsewhere across the airspace.
Conditional risk of fog/vis restrictions overnight especially
at KBFD/KIPT where skies may partially clear out. A much drier
flow pattern will allow for trending/prevailing VFR conditions
through the end of the week.

Outlook...

Thu...Trending VFR.

Fri-Mon...Valley fog in the morning; otherwise VFR/no sig wx.

&&

.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...Steinbugl
SHORT TERM...Steinbugl
LONG TERM...Steinbugl/Colbert
AVIATION...NPB
CLIMATE...NPB