638
FXUS61 KCTP 180118
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
918 PM EDT Wed Jul 17 2024

.SYNOPSIS...
 - The cold front will continue to trek across central PA
   tonight along with a band of mainly stratiform rain showers.

 - Patchy fog is possible tonight mainly across the NW
   mountains and Allegheny Front.

 - High pressure will build in from the Great Lakes on Thursday
   and bring mainly fair weather with seasonable temperatures
   through the end of the week.

&&

.NEAR TERM /UNTIL 8 AM THURSDAY MORNING/...
The cold front is continuing to slide east across the state just
behind an area of mainly stratiform rain showers. Temperatures
are quickly falling behind the front and the environment has
been sufficiently worked over from today`s storms, so any
lingering convection should stay sub severe. The front is moving
quickly along in conjunction with the 500mb upper level trough
and is expected to be in far SE PA by 06Z. Thus, the SHRA should
press mainly or entirely to the S and E of our CWA before
sunrise. Any rain that does fall during the overnight hours will
be mainly beneficial to areas that have recently been dry.

Falling dewpoints should lead to a lower threat of fog, but the
temps dropping right along with them are keeping the chances
for patchy fog around mainly for the northern mountains and
Allegheny front. Any fog that does develop overnight should
quickly lift after sunrise with lowered dewpoints behind the
front and rising daytime temperatures.


&&

.SHORT TERM /8 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
We will begin to see some relief from the excessive heat as
Thursday marks the start of the beginning of a stretch of fair
and seasonable weather with lower humidity during the day
Thursday and all of Friday as surface high pressure builds from
the Great Lakes. Upper level flow will become primarily zonal
Thursday afternoon and into Friday. As a result winds on friday
will be out of the north and should remain calm throughout the
day. High temperatures Thursday and Friday are expected to be in
the upper 70s to mid 80s. Humidity will be much more comfortable
as well with afternoon dewpoints in the mid 50s to low 60s,
which will be a welcome change from the last couple of days.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
On Saturday, there could still be enough moisture working into
the state from the south that a shower or two could develop over
the SE and/or ridge-and-valley region if the ridge tops can help
nudge the moisture high enough. It`s only worth a 20pct chc at
this point based both on coverage and probability. This is the
only mar in an otherwise stellar weekend forecast.

During the early part of the new week, the humidity levels will
creep back up as the deep upper low over ern Canada slides a
little more to the east and the Bermuda High pushes moisture
farther to the north and into the state. The stationary
boundary to our south may struggle to move northward, so we`ll
keep the increase in precip chances slow for the time being.

Overall, we will see muggy nights again by mid week and a
gradual increase in cloud cover and PoPs. By Wed, PoPs get close
to 70pct. Confidence is higher than normal in the extended
pattern. Of course, confidence is lower on the day- to- day
details. But, normal diurnal trends in convection have been
leaned on for most of the long range.

&&

.AVIATION /01Z THURSDAY THROUGH MONDAY/...
MVFR cigs cover northwest and central PA at mid afternoon, and
are overspreading southeastern airfields this afternoon with sct
to nmrs rainshowers and isold ts. Afternoon showers and
thunderstorms will become more numerous and last into the
evening along and ahead of a cold front slowly pushing southeast
from the Great Lakes. Storms should decrease in coverage and
exit/dissipate over the south/eastern airspace between 03-06Z.
There is decent model signal for post- frontal upslope low MVFR
cigs particularly at KJST and potential IFR fog impacts at
KBFD/KIPT late tonight into early Thursday morning.

Outlook...

Thu...MVFR cigs psbl northwest 1/2; low VFR elsewhere.

Fri-Sun...AM valley fog. Otherwise, no sig wx/VFR.

&&

.CLIMATE...
The max temperature hit 100 degrees at Harrisburg yesterday
7/16. The last time KMDT hit 100 was back on July 19, 2020.

&&

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

&&

$$

SYNOPSIS...Bowen
NEAR TERM...Bowen
SHORT TERM...Bowen
LONG TERM...Dangelo
AVIATION...Steinbugl
CLIMATE...Steinbugl