672
FXUS61 KCTP 231706
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
106 PM EDT Thu May 23 2024

.SYNOPSIS...
A front will remain just south of the Commonwealth tonight and
Frida, while a ridge of high pressure slides east across the
state bringing a nice day with dry conditions and comfortably
low humidity. More clouds and an uptick in humidity will arrive
for the upcoming weekend and persist through Memorial day with a
period or two of showers and possible thunderstorms, mainly on
Saturday and Monday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Drier air continues to work into northern and central portions
of central PA as a cold front becomes stationary dropping south
of the Mason Dixon line by this evening. Sfc dewpoints have
dropped through the 50s and into the 40s over the NW Mountains,
and into the lower 60s over the central mountains with partial
clearing over a large portion of central and even south central
PA.

Isold shra and a rogue tsra are possible over the southern third
of central PA this afternoon INVOF the stalling boundary to the
south, and where sfc dewpoints remain in the 60s with PW still
between 1.0 and 1.25". A shortwave traversing nrn VA and the the
panhandles of WV/MD may provide enough of a trigger for this
activity, but mass fields are marginal and do not expect any sig
sensible wx from any of this convection.

Some patchy fog will be possible tonight in areas that remain
clear, with clouds most prevalent across the south near the
stalled boundary. Mins will range from near 50 in the north to
the lower 60s over the southeast.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
Friday is looking like the best weather day of the weekend as a
weak bubble of high pressure keeps fair weather over most of
central PA. The aforementioned stationary front will tend to
lift northward as a warm front by Friday night with showers
likely by Saturday morning over the western Alleghenies. More
diurnally forced showers and storms will develop Saturday
afternoon with daytime heating and some enhancement with a
prefrontal trough. Saturday will not be a washout by any means,
but those with outdoor plans should monitor the weather and head
inside if you hear thunder.

Sunday is now looking to start fair and dry, but the next large
scale weather maker is poised to direct a good slug of moisture
our way for late Sunday and Monday, followed by additional
unsettled days into midweek as a closed low meanders across the
region.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
Compared to Saturday, the chance for showers and thunderstorms
on Sunday will be lower, owing to a weak surface high building
across the Lower Grt Lks into PA. However, with a warm front
approaching, we do carry slight chance to chance PoPs Sun
afternoon, with PoPs increasing to likely Sunday night as the
warm front crosses through the region.

A deepening upper trough will then likely result in a period of
unsettled weather continuing into Memorial Day and the first
half of the upcoming week with mainly scattered, diurnally-
driven convection expected.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Thunderstorms across the eastern airspace will continue moving
eastward early this morning with MVFR vsbys/cigs with locally
lower reductions. Rain is expected to continue for the next
couple of hours with MVFR cigs/vsbys expected. Improvement is
expected by late morning with the majority of the area trending
towards VFR conds by 16-18Z Thursday. Some clear skies remain
possible across N PA later this afternoon.

Guidance has started to indicate some chance of low vsbys and
cigs overnight Thursday into Friday morning, with recent GLAMP
guidance and RAP guidance suggesting JST to experience an
extended period of IFR/LIFR conditions. Given some uncertainty
with regards to extent, have kept restrictions limited to JST at
this time after 08Z Friday.

Outlook...

Fri-Mon...Mainly VFR, but chance of showers/AM patchy fog.

&&

.CLIMATE...
Daily record maximum temperatures for 5/22:

Harrisburg96/1941
Williamsport95/1941
Altoona88/2013
Bradford84/2013
State College89/1975

&&

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

&&

$$

SYNOPSIS...Lambert/DeVoir
NEAR TERM...DeVoir
SHORT TERM...DeVoir
LONG TERM...Lambert/Fitzgerald
AVIATION...NPB
CLIMATE...Steinbugl