Tyrone, Pennsylvania Weather Forecast Discussion

238
FXUS61 KCTP 260814
AFDCTP
Area Forecast Discussion
National Weather Service State College PA
414 AM EDT Fri Sep 26 2025
.SYNOPSIS...
* Low clouds and areas of dense fog early this morning yield to
  partly sunny and less humid conditions for the rest of today
* Light rain forecast at times mainly over the southern tier
  this weekend through early next week; heavy rain stays south
* Noticeably cooler, more seasonable temperatures expected as
  the calender flips to October
&&
.NEAR TERM /THROUGH TONIGHT/...
Areas of dense fog and low stratus early this morning will give
way to breaks of sun and less humid conditions by the afternoon.
DFA remains in effect for the eastern periphery of the CWA
through 9AM. Max temps trend a couple of degrees warmer vs.
yesterday in the 70-80F range or +5-10F above late Sept. climo.
Potent northern stream shortwave/vortmax will move across the
area through 18Z before translating downstream into southern New
England. This feature is currently responsible for spotty
showers over southwest PA into the Laurel Highlands and we can`t
rule out a stray shower or sprinkle farther to the east (the
odds of measurable precip is very low to negligible at less
than 10%).
High pressure slides into CPA tonight, but model data shows high
and mid level clouds streaming northward as a southern stream
upper low pivots over the TN/MS/AL. This may impact fog
formation and overall coverage to some extent given that the NBM
derived wx grids are quite bullish. Best odds for locally dense
radiational valley fog are probably across the northern tier
counties where the sky should remain clear for the longest
duration. Lows 5 to 10 degrees cooler tonight in the 45-60F
range from NW to SE.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Models are coming into better agreement to start the weekend
with increasing chances for light rain focused over south
central and southeast PA. Cloud cover will continue to expand
northward through Saturday night. The rainfall would
correspond to an increasingly moist upslope low level flow and
large scale forcing associated with the aforementioned upper
low pivoting into the central Appalachians, directing plume of
tropical moisture northward along the Mid Atlantic coast.
We will see if the northern stream can fend off a very complex
interaction between the upper trough and two tropical systems
over the Southeast/Mid Atlantic region Sunday through early
next week. Sunday looks dry for now in CPA with high pressure
migrating into the lower Great Lakes region.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
The southern part of the area will again be on the northern
periphery of what could be a significant heavy rain event with
tropical connection possibly setting up over the southern Mid
Atlantic into the Carolinas and south-central Appalachians
through early next week. No rain is projected to the north of
I80 at this time.
The northern stream flexes its muscle and drops a 1030+mb high
pressure dome into New England during the middle to second half
of next week. This pattern (higher confidence given run to run
consistency) would spell a noticeable/seasonable cool down
along with dry wx and refreshingly low humidity as the calendar
flips to October. This may also open the door for frost
potential across the northern tier as suggested by the latest
NBM min temps in the mid 30s Wed and Thu night.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
Fog has already begun to become more widespread than originally
anticipated across the eastern airfields, and confidence is
high in IPT and LNS seeing LIFR conditions throughout the night
with fog having already settled into those sites. Elsewhere fog
and low ceilings will continue to degrade conditions throughout
the remainder of tonight with widespread IFR anticipated by 09Z
at most sites. There remains a roughly 30% chance that AOO and
UNV will remain VFR through the night, but the most likely
scenario is some reductions of flight categories occurring at
all TAF sites.
Improving conditions to widespread VFR by late Friday morning,
as slightly drier air works into the area. There is some signal
that a broken to scattered deck of MVFR clouds could linger at
BFD, JST, IPT, and UNV into the early afternoon, but gradual
improvement is expected. A few isolated showers could affect
those same airfields on Friday, but confidence and expected
duration remain low enough to preclude any mention in the TAFs.
Outlook...
Fri...Low cigs early trending VFR by Friday afternoon.
Decreasing odds for rain.
Sat-Tues...Low confidence in sub-VFR cigs/rain across the
southern/eastern portions of the airspace. Mainly VFR across the
Central and Northern 2/3rds of PA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
Dense Fog Advisory until 9 AM EDT this morning for PAZ037-041-
042-046-051>053-058-059-065-066.
&&
$$
SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl
SHORT TERM...Steinbugl
LONG TERM...Steinbugl
AVIATION...Banghoff/Bowen

NWS CTP Office Area Forecast Discussion