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926
FXUS61 KCTP 252253
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
653 PM EDT Mon Sep 25 2017

.SYNOPSIS...
Unseasonable late-September heat will continue in central PA
through mid week. Mostly dry weather will also prevail with
a passing shower possible in spots on Wednesday and Friday or
Saturday. A pattern change will bring cooler, fall-like weather
back to the area for second half of the week into the upcoming
weekend.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Yet another warm and muggy late-summer-like evening in progress
here in late September. The overnight will be more of the same
thanks to sprawling upper ridge...very mild with mainly clear
skies and more valley fog after midnight lasting into early
Tuesday morning.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Another day of summerlike heat and humidity expected across
central PA. Highs may be trimmed a bit across southeast PA as
some clouds bands associated with Maria wrap into the area. Some
hires and even coarser global models try to develop some
isolated convection Tuesday afternoon but odds remain strongly
in favor of dry wx pattern.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
By Wed, the start of the cooldown back to seasonal temperatures
will be underway. The blocking high that has been responsible
for the recent extended spell of dry and anomalously warm
conditions will flatten as a trough slides across southern
Canada, dragging a weak cold front through on Wed and nudging
Maria eastward. This front will bring our first chance of rain
in quite a while - though with the front weakening and falling
apart as it moves through any scattered showers will remain
light.

Maria (remaining offshore of the Carolinas) will make it as far
north as the NC/VA line before it takes its hard turn eastward
and finally tracks away from the east coast.

A bit more significant trough will approach for late week into
the weekend, bringing a reinforcement of the cooler temperatures
and a renewed chance for light yet scattered showers as the
airmass remains quite dry.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
Widespread VFR conditions into tonight. No reason to deviate
from persistence with fog restrictions likely again after
midnight into early Tuesday morning. Based on persistence and
latest model data, believe a period of IFR/LIFR conditions are
likely (mainly between 08Z-13Z) at KBFD/KIPT/KUNV/KAOO/KLNS,
possible at KMDT and very unlikely at KJST.

Wed...Spotty PM shower possible. Mainly VFR.

Thu...No sig wx expected.

Fri-Sat...Isold-sct showers possible. Mainly VFR.

&&

.CLIMATE...
Record-challenging late-September heat through early week.
Daily high temperature records for 9/25 and 9/26:

Bradford: 83 in 2007, 79 in 1998

*Williamsport: 89 in 1970, 92 in 1900

Harrisburg: 93 in 1970, 91 in 1970

Altoona: 90 in 1970, 88 in 1998

*Williamsport maximum temperature records are under review for
 Saturday and Sunday 9/23-9/24.

&&

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

&&

$$
SYNOPSIS...Steinbugl
NEAR TERM...DeVoir/Steinbugl
SHORT TERM...Steinbugl
LONG TERM...RXR
AVIATION...Fitzgerald/Steinbugl
CLIMATE...