Johnsonburg, Pennsylvania Weather Forecast Discussion

647
FXUS61 KCTP 080156
AFDCTP
Area Forecast Discussion
National Weather Service State College PA
956 PM EDT Sun Sep 7 2025
.SYNOPSIS...
* A large area of high pressure will bring generally dry
  conditions with partly to mostly sunny and low daytime
  humidity for at least the next 5 days after any early morning
  valley fog dissipates by 10 AM.
&&
.NEAR TERM /THROUGH MONDAY/...
Almost totally clear over the CWA at 02Z. BFD has dropped 6F
from 00-01Z, and may drop several more in the next hr/two. Upper
trough axis should be overhead in a few hours. There are new
clouds moving across/off the lakes. This probably won`t stop
until the temp advection changes sign on Monday. The presence
of clouds off the lakes would thwart frost and fog formation,
but most moisture profiles keep the thickest clouds from getting
too far past Warren Co. Overall, the frost advy should be fine.
See no compelling reasons to expand at this point, and
certainly no reasons to contract. Evening update tweaks are very
minor. Made sure areas of frost were mentioned and ensured that
temps are on track with current obs.
Prev...
Northwest flow over Lake Erie will keep the potential for a few
lake effect rain showers in place through the rest of the
afternoon and into the first half of the night for far northwest
PA. The rest of the region will continue to see partly cloudy
skies with high temperatures in the 60s and low 70s.
A much drier air mass characterized by PWATs below the 10th
percentile for this time of year will move in overnight as high
pressure builds in from the west. Clearing skies and light winds
will support efficient radiational cooling, with many areas
north and west of the Allegheny Front likely to see temperatures
falling into the mid to upper 30s by early Monday morning.
Frost formation is likely and a Frost Advisory has been issued
for much of the northern and western mountains. There appears to
be at least some potential for portions of McKean County to see
temperatures dip below freezing, but with some lingering
uncertainty regarding how quickly cloud cover decreases, we have
opted against going with a Freeze Warning.
Temperatures will rise quickly after sunrise, ending the risk of
frost by 8 AM. Monday will feature near to slightly below normal
temperatures with highs in the upper 60s and low 70s, along
with mainly clear skies.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
Another chilly night is expected for Monday night, though frost
potential does not look as widespread as the night before. As of
now, the best chance for frost looks to be limited to McKean
County where temperatures will likely fall into the mid 30s. If
confidence increases in frost potential, another Frost Advisory
may be needed. Dry weather continues on Tuesday, though
temperatures trend a few degrees higher, with most of Central
Pennsylvania seeing highs in the low to mid 70s.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Abundant sunshine and dry conditions are favored into the end of
the week, with temperatures trending warmer for Wednesday
thanks to a building ridge aloft. A weak, moisture-starved cold
front will track through the region Wednesday night into
Thursday, but no sensible weather impacts are expected.
Temperatures may drop slightly for Thursday and Friday behind
this front, but a warming trend is expected into the weekend.
Some guidance shows another shortwave moving through Saturday
night into Sunday, potentially bringing a few showers along with
it, but uncertainty remains high.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
Mostly clear skies across the area will continue to clear out
overnight, leading to widespread VFR conditions for much of
central Pennsylvania through 00Z Tuesday with very high
(~90-100%) confidence. Under the influence of high pressure,
winds are also progged by all model guidance to trend calm,
which will allow for valley fog potential across the northern
tier of Pennsylvania. Airfields at most risk for restrictions
remain at BFD/IPT, where VCFG will be in play between 08-11Z
Monday. At this time, confidence remains too low to mention in
the TAF, with fog mixing out quickly after sunrise and leading
to widespread VFR conditions to prevail once again.
Outlook...
Tue-Fri...Mainly VFR. Morning valley fog.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from 2 AM to 8 AM EDT Monday for PAZ005-006-
010>012-017>019-024-033-037-042-045.
&&
$$
SYNOPSIS...Lambert/Bauco
NEAR TERM...Dangelo/Bauco
SHORT TERM...Bauco
LONG TERM...Lambert/Bauco
AVIATION...NPB

NWS CTP Office Area Forecast Discussion