Area Forecast Discussion
Issued by NWS State College, PA

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000
FXUS61 KCTP 020129
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
929 PM EDT Sat Oct 1 2022

.SYNOPSIS...
Upper level low pressure will keep spinning over WV/VA for the
next two days. Periods of light to moderate intensity rain will
stick around through Sunday evening. Upstream ridging pushes in
on Monday and dries things out. A cold front approaches from the
west late in the week. Dry, cool weather follows for next
weekend.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
The main focus of steady, moderate rain through the evening will
continue across a relatively narrow west-east oriented band
just north of I-80, where an axis of midlevel deformation/
frontogenesis coincides with maximum east-west moisture
transport. Rainfall rates in this band have been 0.25-0.50
inch/hr.

Not much change in forcing for the overnight, just tiny
perturbations/shortwaves rotating around the low every few
hours. Thanks to the clouds and rainfall temps will not drop
much for the overnight. Dewpoints will rise a little and we
saturate, esp across the south. Rainfall is expected to expand
across the Laurel tonight and eventually into the Lower Susq by
the predawn on Sunday. An additional 1-2" of rain is expected
across southern zones through Sun night. Despite lower FFG in
the southwest, rain should fall over an extended period of
time, not in a brief- enough amount of time to make anything
worse than wet roads and filled roadside ditches.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
The upper low nears/heights fall slightly Sunday as the
compact/cutoff low transitions to an open and pos tilted
trough. This will help slide the best moisture to the east
while the sfc high continues to build south. This combo will
press the bulk of the precip S and E on Sunday, and allow it to
become more patchy/showery. Still mainly cloudy to overcast
conditions will prevail over much of the area. Some clearing
will begin in the NW very late Sunday, and continue Sun night.
Areas that received rainfall earlier in the day may fog up. The
nrn tier will try to drop into the 30s, but some wind and
marginal dewpoints (close to 32F) might stand in the way of
frost formation.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Synoptically, the pesky late weekend and early work week upper
low near the Mid-Atlantic coast should finally begin to open
and move into the western Atlantic by mid-week, to temporarily
be replaced by flat shortwave ridging aloft. Thereafter, as
upper ridging builds over the western CONUS and southwestern
Canada, a downstream upper trough will deepen over the Great
Lakes and northeastern states from late in the week into next
weekend.

As for the daily sensible weather, slim shower chances persist
across portions of the lower Susquehanna Valley Monday/Tuesday
nearer the upper forcing and greater moisture source. Wednesday
and early Thursday look dry and fairly mild, as a warm
advective southwesterly flow develops ahead of an approaching
surface cold front. The just mentioned cold front is progged to
cross the Commonwealth by early Friday, accompanied by at least
scattered showers. The end of the week through at least next
weekend looks to turn noticeably cooler at this time, as a very
chilly air mass drops down from south-central Canada. The
combination of this chilled air moving over the warmer Great
Lakes waters, plus short-wave energy aloft should lead to at
least scattered showers over northwestern PA and the
Alleghenies. Farther east towards the Susquehanna Valley,
downsloping should produce mainly dry weather.

Daily highs in the 60s Monday/Tuesday, warming into the upper
60s and 70s Wednesday/Thursday, should drop quite a bit by
Friday and Saturday.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
At 00z, periods of rain or drizzle continue to affect much of
central PA. IFR cigs were found across most of the southern
half of PA, with MVFR to VFR cigs progressing farther to the
north. Only BFD remains dry and solidly VFR. Locations that are
seeing rain/drizzle are largely experiencing MVFR vsbys (or
even IFR, briefly).

Expect poor flying conditions to continue overnight, especially
across southern PA. Cigs will likely remain relatively stable
overnight across southern PA, while northern PA sees cigs drop
to MVFR. Periods of rain and drizzle will continue overnight as
well.

Skies could begin to clear later Sunday across the west, while
clouds and periods of rain linger across south-central and
southeastern PA. The upper low will begin to open up and drift
eastward on Sunday, and should eventually take most of the rain
southeast of the Lower Susq Valley Sunday night or Monday.

Outlook...

Mon...Chance of rain showers lingers across far southeastern
PA. Otherwise, widespread improvement.

Tue-Thu...Generally VFR, except for some AM valley fog.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$
SYNOPSIS...Dangelo/Colbert
NEAR TERM...Dangelo/Colbert
SHORT TERM...Dangelo/Colbert
LONG TERM...Guseman/Colbert
AVIATION...Evanego


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