281
FXUS61 KCTP 061745
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
145 PM EDT Mon May 6 2024

.SYNOPSIS...
- Scattered showers and thunderstorms possible across south central
  PA this afternoon
- Widespread showers and storms are likely for Tuesday night
  through Thursday as the unsettled pattern continues
- Cooler temperatures and lingering scattered showers are
  expected for Friday and into the beginning of the weekend

&&

.NEAR TERM /THROUGH TONIGHT/...
The fog has finally lifted across all of PA giving way to mostly
cloudy skies with some sunshine peeking through across the
norther tier. Temperatures will rise into the mid 70s for much
of central PA this afternoon, which will feel noticeably warmer
than this past weekend.

A weak cold front pushing eastward through the area has a few
showers along it early this morning. As it moves south of
Interstate 80 this afternoon, it will tap into enough moisture
and instability to support more numerous showers and perhaps a
few thunderstorms as the front approaches the Maryland border.
The highest chance for a few lightning strikes will be across
the Laurel highlands, where MLCAPE is progged to reach 750-1000
J/kg. Meanwhile, enough dry air will nudge into northern PA for
a few peeks of sunshine.

Most model guidance shows the convective activity along the
southern tier waning tonight with the loss of daytime heating,
but isolated to scattered light rain showers will likely
persist. Some fog is possible tonight as well, though
confidence in fog is not as high as it was last night. Low temps
will range form the mid 40s along the NY border to around 60F
in the southern tier, with the north to south gradient in
moisture playing a large role in overnight cooling.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
Upper level ridging over PA indicates warmer conditions are
likely Tuesday with highs reaching the upper 70s to near 80F. A
warm front lifting out of the Ohio Valley, a 500mb short wave
trough, and 850mb warm air advection pattern will result in
increasing clouds with a PM shower/tsra, primarily across the
western counties. Showers and a few storms will overspread the
area Tuesday night as the warm front progresses northeast. MU
CAPE during this time is likely to increase to near 1000 J/kg
and support widespread thunderstorm activity.

Low temperatures Tuesday night will dip to the low 60s across
the northern tier of the CWA and remain in the mid 60s in the
Lower Susquehanna Valley.

Unsettled weather will continue into Wednesday and Thursday.
Wednesday looks to be another warm day, with ensemble mean 850mb
temps of 16C suggesting max temps well into the 80s across the
Lower Susq Valley. Upper-level divergence overhead will be
supportive of widespread showers and thunderstorms as the large
scale upper level trough swings across the state. An 850mb LLJ
will also be in place on Wednesday and Thursday during the 9-15z
time frame, supporting late night/early morning convection. The
SPC has outlined this threat with a MRGL SWO for Wednesday
night/Thursday morning.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
The best chance for widespread showers and thunderstorms
continues to be focused on Wed night into Thursday, with a
deepening upstream trough and sfc low pressure riding up the
Ohio Valley and across the area. The SPC highlights our area in
a MRGL risk for severe weather during this time frame, on the
periphery of a SLGHT-ENH risk area over the Ohio Valley.

The surface low and deepest moisture is progged to shift east
of the area Thursday night. However, falling heights ahead of
the upper trough will likely support scattered diurnal
convection Friday through Sunday, along with a downward trend
in temperatures.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
A moist southeast flow off of the Atlantic Ocean will maintain
stratus over Central PA tonight with widespread IFR/LIFR cigs
and ridgetop fog. Improving flying conditions look likely
Monday as high pressure builds into the region from the Grt Lks,
causing winds to shift from southeast to north. Latest forecast
soundings and ensemble prob charts support a transition to MVFR
during early afternoon and potentially VFR by late in the day.
Low pressure lifting up the Ohio Valley could spread showers
and reduced cigs into the southern tier of PA Monday evening.

Outlook...

Tue...AM low cigs/showers possible southern tier of PA. Isold
evening tsra impacts possible W Mtns.

Wed...AM low cigs/tsra possible.

Thu...Rain/low cigs likely.

Fri...Showers/low cigs possible, mainly AM.

&&

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

&&

$$

SYNOPSIS...Bowen
NEAR TERM...Colbert/Bowen
SHORT TERM...Colbert/Bowen
LONG TERM...Fitzgerald/Evanego/Colbert
AVIATION...Fitzgerald/RXR