Barry, Pennsylvania Weather Forecast Discussion

097
FXUS61 KCTP 290807
AFDCTP
Area Forecast Discussion
National Weather Service State College PA
407 AM EDT Mon Sep 29 2025
.SYNOPSIS...
* Very warm to close out September; cool down to start October
* Frost risk focused across the northern tier Wednesday night
* Dry/parched pattern stays locked in place for the 7-10 days
&&
.NEAR TERM /THROUGH TONIGHT/...
Early morning IR satellite shows valley fog across the NW 1/2 of
the CWA where skies are clear. HREF data shows high clouds
across the SE 1/2 of the fcst area overspreading all of CPA by
early afternoon. Despite a partly sunny to mostly cloudy day on
balance, it will be very warm for the end of September with max
temps in the 75-80F range or +7-15 degrees above the historical
average.
Canopy of mid and high cloud cover should limit fog formation
tonight into early Tuesday morning. Another relatively mild
night vs. climo (+5-10F) with lows generally in the upper 40s
NW to low 60s SE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
September ends very mild with max temps fcst in the 70-80F
range. Shield of mid and high clouds are projected to gradually
clear from NW to SE through Tuesday night. Backdoor cold frontal
passage later Tuesday will open the door for seasonably cooler
and drier air to filter into CPA behind a steady breeze from the
N/NE. Low temps Tuesday night will be 5-10 degrees lower vs.
Monday night ranging from the upper 30s in the northern tier to
low 50s in the Lower Susquehanna Valley.
October will start with seasonably strong 1030+mb Canadian HP
migrating southeast from Hudson/James Bay into northern New
England. The cooler and drier llvl flow from the N/NE will
bring a noticeable cool down through midweek with highs on
Wednesday 5-10 degrees lower vs. Tuesday in the low 60s/70s.
Clear and cool Wednesday night; high confidence in frost risk
across the northern tier with decreasing wind and min temps in
the mid 30s.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
Slow moving and blocky pattern under deep layer ridging over
the Mid Atlantic and Northeast states will lock-in the renewed
run of dry wx through the first weekend of October. NBM/WPC QPF
is 0.00" in CPA for the next 7+ days.
Thursday night also looks chilly with some frost possible again
over the northern tier; otherwise look for max/min temps to
rebound (day over day) with larger departures from climo on
daytime highs vs. nighttime lows (which is largely a function of
the dry/low Td air remaining in place).
The return of the multi-day/persistent parched pattern could
offset any short term improvement in the low-end drought
conditions from much needed/beneficial rainfall last week.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
Tonight will feature, mainly clear skies with a few high clouds
still present across the southeastern airfields. VFR conditions
are expected with roughly 90% confidence through the early
morning. Despite good conditions for radiational cooling,
confidence is low on overnight fog development to impact
airfields as dry air has begun advecting in from the north.
Forecast hydrolapses show humidity decreasing with height above
the surface, which would favor more dew vs fog. In addition, the
aforementioned high clouds encroaching on the Lower Susq Valley
by daybreak may lessen evaporative cooling, reducing the chc of
fog formation there.
Once any lingering fog dissipates Monday morning, we should be
in for another day of widespread VFR conds late Monday morning
through Monday afternoon. Winds will again be relatively light,
generally less than 5 kts.
Outlook...
Tue...Patchy AM fog. Otherwise, predominantly VFR.
Wed-Sat...Predominantly VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Steinbugl
LONG TERM...Steinbugl
AVIATION...Colbert/Bowen

NWS CTP Office Area Forecast Discussion