101
FXUS61 KCTP 181110
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
710 AM EDT Mon Aug 18 2025

.SYNOPSIS...
* Not as warm/seasonably cooler this week with peak summer heat
  and humidity in the rear view mirror
* Little to no rainfall expected through Friday; best rain
  chances on Wednesday and over the weekend
* Refreshing taste of Fall likely to arrive into the last week
  of August

&&

.NEAR TERM /THROUGH TONIGHT/...
Seasonably strong 1025+mb high pressure drifting eastward
across Ontario and Quebec will deliver pleasantly cooler and
less humid conditions today. The most refreshing (low dewpoint)
air will be across the northern tier, while the largest 24hr max
temp deltas will be found across the south central ridges
through the middle and lower Susquehanna Valley where easterly
flow and low clouds will help hold highs 10-20 degrees lower vs.
yesterday.

Veering and increasingly moist llvl flow to the east/southeast
will maintain and even expand the low stratus overnight. The
upslope flow may even bring some patchy drizzle and/or ridgetop
fog to portions of south central PA. Low temps will range from
50-55F in the northern tier to 60-65F across the south central
ridge/valley region.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Low cloud signal prevails to the east of the Allegheny Front on
Tuesday with a spotty shower possible over south central PA.
The cloud cover (with some PM breaks of sun) will again hold
temps in the 70s over the majority of the fcst area.

Shortwave trough diving southeast from the Great Lakes and sfc
wave in the Ohio Valley will bring the "best" chance of rain (in
the next 3 days) on Wednesday -- although QPF output continues
to look rather limited. Low temps Wednesday night should tick
higher by a few degrees with more low clouds.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Increasing confidence in a dry end to the week thanks to large
scale subsidence to the west of departing Hurricane Erin. Rising
heights into the weekend will promote a warming trend with highs
rebounding back into the lower 80s by Friday.

Longer range model and ensemble data continues to show a more
formidable upper trough digging into the Great Lakes and
amplifying this weekend over the Eastern U.S. Moisture
returning northward from the Gulf along the leading frontal
boundary should provide a focus for showers and storms with max
POPs Sat-Sun as it moves slowly eastward from the Appalachians
toward the Mid Atlantic coast.

Taste of Fall on the horizon for at least the first part of next
week as cooler/more refreshing air filters into the region from
Canada.

&&

.AVIATION /11Z MONDAY THROUGH FRIDAY/...
MVFR ceilings across many central Pennsylvania airfields will
continue through ~14Z before the bulk of model guidance
indicates improvement at all airfields outside of MDT/LNS with
moderate (~40-50%) confidence. At MDT/LNS, low-level moisture is
expected to increase over the next couple of hours with a
slight easterly component in low-level winds. Continued MVFR
ceilings are progged by NBM/GLAMP/HREF guidance, thus have
higher confidence in MVFR ceilings with lower confidence on
timing of low-level ceilings trending up towards MVFR in the
18-22Z timeframe. Once VFR conditions prevail, high (~80-90%)
confidence in those continuing through ~06Z Tuesday across all
airfields before the bulk of model guidance indicates low-level
moisture increasing in RAP soundings. At this time, MVFR
ceilings seem to be the most plausible solution at UNV/IPT, with
recent GLAMP/HREF guidance indicating borderline IFR conditions
at BFD/JST/AOO. Slightly higher confidence at BFD/JST, thus the
12Z TAF package does indicate slightly lower ceilings with most
uncertainty at AOO in this timeframe.

Outlook...

Tue-Fri...Chc of SHRA/TSRA areawide but generally VFR.

&&

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

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Steinbugl
LONG TERM...Steinbugl
AVIATION...NPB