Area Forecast Discussion
Issued by NWS State College, PA-- Remove Highlighting --
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FXUS61 KCTP 240655
Area Forecast Discussion
National Weather Service State College PA
255 AM EDT WED AUG 24 2016
A seasonably warm and humid late-summer weather pattern will
continue across Central Pennsylvania through the weekend. The
most likely period for thunderstorms remains Thursday into early
.NEAR TERM /THROUGH TONIGHT/...
Mainly clear skies and calm winds will favor valley fog formation
through the predawn hours. The fog should dissipate by 8-9am. High
pressure retreating off the Northeast coast will ensure another
dry day with southerly return flow bringing warmer temperatures
and gradual uptick in dewpoints/humidity levels. Forecast maximum
temperatures are running about 5 degrees above normal for late
Multi-model/high resolution ensemble blend still highlights NW PA
to the west of US-219 with max POPs /20-40 percent/ in the 00-12z
Thursday period. The risk for showers is coincident with surge of
theta-e/warm advection and moisture flux on nose of 20-30kt WSW
LLJ. Milder overnight temps in the low-mid 60s.
.SHORT TERM /THURSDAY/...
Model data shows another glancing blow from passing shortwave
energy/height falls to the NW of the area on Thursday as upper
ridge holds firm from the Mid South up along the Atlantic coast.
However, there appears to be sufficient moisture/instability with
the weakening cold front/surface trough to trigger scattered to
numerous thunderstorms during afternoon/evening. Consensus blend
yielded max POPs over the NW 1/3 of the CWA. SPC Day 2 outlook is
largely unchanged from the previous Day 3 with just a slight NWD
shift in the MRGL risk across the OH Valley into far western PA.
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
The front should become rather diffuse on Friday with risk of
thunderstorms confined along/ahead of the boundary. The best
location at this time appears to be the southeast 1/3 of the CWA
and therefore painted low POPs during the day before drying things
out Friday night.
Another extensive upper ridge resumes control of the weather
pattern into the weekend. This should translate into a seasonably
warm and somewhat muggy period although not anything like the 70+
dewpoints we experienced around mid-month. The models seem to open
the door for isolated airmass/terrain-induced convection by Sunday
afternoon, however the odds still favor a mainly dry weekend for
most locations. For next week, the guidance is suggesting a
shortwave tracking to the north of PA will drag a trailing frontal
boundary into PA which may become quasi-stationary Mon-Tue. This
feature would provide a focus for thunderstorm activity and have
generally trended POPs upward beyond Sunday.
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
Expect VFR conditions early this morning to give way to some
areas of MVFR and local IFR conditions in fog.
Morning fog will give way to another VFR day on Wednesday.
Approaching front with increased moisture could bring a chance of
TSRA on Thursday, mainly in the west.
Wed...Patchy AM fog possible, otherwise VFR.
Thu...Generally VFR, but with Isold pm tsra impacts possible,
mainly w mtns.
Fri...Morning low cigs possible across the Western Mountains,
Sat-Sun...No sig wx expected.