756
FXUS61 KCTP 300107
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
907 PM EDT Fri Aug 29 2025

.SYNOPSIS...
* Chilly fall-like pattern with low humidity continues through
  Saturday with frost possible in NW PA Saturday morning.
* Meteorological Fall (September 1) kicks off with continued
  pleasant and dry conditions and a gradual warmup for Monday
  through Wednesday.
* Cold front to bring some rain Thursday and return to below
  normal temperatures again next weekend.

&&

.NEAR TERM /UNTIL 9 AM SATURDAY MORNING/...
Fair weather cumulus clouds have fallen apart with the loss of
daytime heating, but lake effect stratocumulus are pouring into
northwest PA from Lake Erie. A ridge of high pressure continues
to move toward PA, and will be centered over Michigan tonight,
ensuring light or calm winds across the region. Skies should
remain mainly clear across everywhere except extreme NW PA
overnight, ensuring ideal radiational cooling conditions.

Valley fog is a sure bet tonight in northwest PA where moisture
air/water temperature differences are sufficiently large.
Persistence would indicate that several of the deepest/most
protected valleys in the northern mountains will dip into the
mid to upper 30s overnight. KBFD recorded a low of 35F on
Thursday morning, and that seems plausible again Saturday
morning. Despite clouds overhead there now, 850mb winds should
veer to just west of north over Lake Erie overnight, which
should direct most of the clouds toward Warren and western
McKean County. As that occurs, we expect dewpoints to drop along
with temperatures, resulting in frost formation across McKean
and Potter County. A Frost Advisory is in effect from 4AM to 9AM
Saturday morning there. If more clearing occurs, a few locations
could see temperatures approach 32F. If clouds hang on longer
than expected, frost may be less prevalent in McKean County.

Saturday morning will be the coolest since early June and the
coolest in the foreseeable future, with lows ranging from the
mid 30s in the northwest to low 50s along the Susquehanna River
in southeast PA. Most of the Commonwealth will see lows in the
40s.


&&

.SHORT TERM /9 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
Saturday will feature a prolonged return to mostly sunny skies,
low daytime humidity with excellent vsby and high temps in the
upper 60s to mid 70s from the northern and western high terrain,
to the Valleys of Scent and SE PA. Strong high pressure will
firmly be in place by Saturday afternoon. The center of the high
will be located over the southern Great Lakes region. The fall
like conditions will be here to stick around for the end of
August.

Another nice night is expected Saturday night with temperatures
trending a few degrees warmer compared to tonight. Valley fog
across the northern tier is another sure bet.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
High pressure from north-central Canada will keep it (very) dry
for the second half of the weekend. The compact upper low just
to our NE will finally lift away before the start of the work
week, but troughiness remains. The sfc high should fend off
rainfall until the second half of the upcoming week. However,
low level southeast flow could make for some pesky low clouds
at times. Temps rise only slightly for the first half of the
week (maxes in the 70s and lower 80s). The next chance for rain
will not arrive until late Wednesday into Thursday as the next
spoke of the upper level trough swings down from central Canada
to bring another cold frontal passage to the Mid-Atlantic and
New England regions.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
Widespread VFR conditions are expected through the 00Z TAF
period as high pressure builds into the region. Skies will be
mainly clear outside of scattered clouds downwind of Lake Erie.
While some valley fog will likely form over northern
Pennsylvania, it is unlikely to impact any airfields. Winds on
Saturday will be out of the northwest at 5 to 10 knots.

Outlook...

Sun-Tue...AM valley fog possible; otherwise predominantly VFR.

Wed...Isolated SHRA possible in the afternoon.

&&

.CLIMATE...
Altoona set a record low temperature yesterday (8/27) of 43
degrees (45 in 1958).

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from 4 AM to 9 AM EDT Saturday for PAZ005-006.

&&

$$

SYNOPSIS...Banghoff/Bowen
NEAR TERM...Banghoff/Bowen
SHORT TERM...Banghoff/Bowen
LONG TERM...Bowen
AVIATION...Bauco
CLIMATE...Dangelo