Morris Run, Pennsylvania Weather Forecast Discussion

092
FXUS61 KCTP 011057
AFDCTP
Area Forecast Discussion
National Weather Service State College PA
657 AM EDT Wed Oct 1 2025
.SYNOPSIS...
* Cooler temperatures for the first 2 days of October bringing
  widespread frost across the Northern Tier counties of
  Pennsylvania tonight and early Thursday
* Our building string of dry days will likely extend for another
  week to 10 days, possibly interrupted by a few hour period of
  showers later next Tuesday night into Wednesday
* Temperatures moderating this weekend into next week
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Posted a Frost Advisory for several Northern Tier Counties of PA
for late tonight through the mid morning hours on Thursday, after
nudging current forecast temps a large amount toward
NBM25Percentile guidance.
1033 mb sfc high pressure centered over the shores of James Bay
Canada will be building gradually south through late this week,
bringing continued dry conditions and abundant sunshine today
(and likely right through this upcoming weekend and into early
next week). Cooler daytime temps advecting into the area via
north to northeast winds of generally under 10 mph in the wake
of a backdoor cold front will result in maxes today 7-9 deg F
lower than recent days,
The northern edge of the shield of mid and high clouds (well to
the NW of Hurricane Imelda) is just brushing the far SE zone of
our CWA early today, with clear skies elsewhere over Central and
Northern PA.
High temps today will be in the mid 70s across the higher
terrain of the north and west and in the upper 70s to low 80s in
the Central and Southern Valleys. These high temps will be
several degrees above normal for this time of year.
Lower dewpoints will filter into the region early today, slipping
back into the mid 30s (north) to low and mid 40s (across much of
the Central Ridge and Valley Region by late this morning.
Temps to start the day today will range from the upper 30s near
the PA/NY border, to the mid 40s to low 50s respectively across
Central and Southern PA. The northeast winds will also prevent
any fog concerns early today.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
The cooler and drier low level flow from the N/NE will bring a
noticeable cool down through Thursday. Afternoon highs on Thursday
look cooler than Wednesday as southeast flow rotating around
the sprawling high will set up a typical cool-air damming
scenario. Highs likely struggle to crest the 70F mark in
Southern PA on Thursday, while some of the highest terrain of
Northern PA could experience temps for much of the midday and
afternoon hours only around 60F.
Clear skies are a sure bet for tonight with high confidence for
frost/freeze over northern PA, given diminishing wind, low
dewpoints and min temps in the low to mid 30s. GFS MOS guidance
shows 32F for Bradford at sunrise Thursday, which highlights
the fact that and anomalously dry airmass underneath high
pressure this time of year can yield under-performing
temperatures.
The chance for freezing temperatures remains low enough that a
Freeze Watch was not issued, but a few spots below 32F cannot
are expected Thursday morning. That being said, frost is nearly
a sure bet for a stripe of counties along the PA/NY border
(including Elk and Sullivan counties) with a potential for Frost
all the way down to I-80. Individuals with active
gardens/flowers should prepare to take necessary steps to
protect vulnerable vegetation.
Clouds will be on the increase a bit Thursday night, which
should keep temperatures above the frost/freeze mark by Friday
morning.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
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.
As high pressure moves just each of the region later this week,
southwest flow will usher in slightly milder temperatures each
day. Temperatures moderate back to well-above normal by the
second half of the weekend. Calm winds combined with clear skies
and a gradual uptick in surface moisture will likely lead to
daily occurrences of fog in the typical river valleys across
northern PA. 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.
There remains considerable spread in long-range guidance
regarding the potential for some rain by the middle of next
week. Even if a weather system moves through, rainfall totals
will likely be minuscule because there is no tropical moisture
in sight in the Mid-Atlantic.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
Dry air and mostly clear skies will keep VFR conditions dominant
through out the next few days. High pressure has settled into
the area and the last of the clouds from hurricane Imelda and
Humberto have left southeastern PA overnight as those systems
pull further eastward.
There is no precipitation in the forecast for the next seven
days given upper level ridging and surface high pressure
remaining firmly entrenched in the Mid-Atlantic region. Skies
will remain clear overnight tonight, but given winds and dry air
the chance for morning fog to occur Thursday morning remains
less than 20%.
Outlook...
Thu-Sun: AM fog; otherwise VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from midnight tonight to 9 AM EDT Thursday for
PAZ005-006-010-037-042.
&&
$$
SYNOPSIS...Lambert
NEAR TERM...Lambert
SHORT TERM...Lambert
LONG TERM...Steinbugl/Banghoff
AVIATION...Bowen

NWS CTP Office Area Forecast Discussion