Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 252001

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

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


Another unseasonably warm and muggy late-September day in
progress with max temperatures fcst to reach the mid 80s to
low 90s or +15-20 degrees above normal. It will feel even
warmer with max HX values between 90 and 95 degrees; a few spots
may event get into the mid-upper 90s. Hard to deviate from
persistence in this pattern. Tonight will be another repeat:
very mild with mainly clear skies and more valley fog after
midnight lasting into early Tuesday morning.


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.


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

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.


Widespread VFR conditions into tonight. No reason to deviate
from persistence with fog restrictions likely again after
midnight into early Tuesday morning.

Tue...AM valley fog becoming VFR.

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

Thu...No sig wx expected.

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


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.




NEAR TERM...Steinbugl
SHORT TERM...Steinbugl
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