786
FXUS61 KCTP 292353
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
753 PM EDT Wed May 29 2024

.SYNOPSIS...
*Numerous showers/t-storms expected this afternoon and evening
*Drying trend to end May with below normal temperatures
*Temperatures warm to near normal to start June with rain
 chances increasing into early next week

&&

.NEAR TERM /UNTIL 7 AM THURSDAY MORNING/...
Circulation in mid-levels is over the central mountains (was
just over the office). Heaviest rain is is now sliding to the SE
of the local area and is only making a little thunder. Much of
the area has stabilized from the earlier rainfall. No flooding
concerns at this time, with FFG not approached for a few hours,
now. Cells are moving, now, versus the pivoting rainband(s), and
a few slow-moving cells of earlier. Clearing line is back along
the nrn shore of LE, but is moving this way. Clearing is
expected for a large part of the CWA through the night. The
potential for dense fog tonight is there, but the very light
wind may be just enough to keep it from forming. Will just
expand the area where we mention patchy fog at this point.

Prev...
The main band of thunderstorms associated with an approaching
surface low is continuing to work its way northward and is
just through State College as of 17Z. Most guidance suggests
that the northward progression of this band will slow over the
next few hours and may sit over the area north of I-80 for a
while. Repeating heavy downpours in this area could produce
local QPF maxes around 1.5-2" as they maneuver over the region
into the evening, and even though PWATs are fairly low (only
around 1"), there could be some localized flooding concerns. WPC
has added a sight risk of excessive rainfall for the northern
portion of the CWA as a result. Showers and thunderstorms will
be possible elsewhere across Central PA as well into the
evening, but they will not pose as much of a heavy rainfall
threat. Max temps will be 5 to 10 degrees below late May climo
across most of CPA this afternoon with highs in the 60-75F
range.

Shower activity shifts to the east tonight with patchy fog
possible over the western Alleghenies where skies should clear
out. Seasonably cool night ahead with lows in the 40-55F range.

&&

.SHORT TERM /7 AM THURSDAY MORNING THROUGH SATURDAY/...
Final shortwave trough rotates through CPA on Thursday. A
couple of showers or an isolated PM t-storm are possible
Thursday afternoon beneath the upper trough axis mainly over
southeast PA, but lower pwat air pouring into the region via
NNW low level flow should keep most places dry. Highs will again
be cooler-than-average with fcst max temps in the low 60s/70s.

Seasonably strong high pressure dome migrates eastward from the
OH Valley Thursday night into western PA early Friday morning.
This setup should support one of the coolest nights in a while
with low temps in the mid 30s to upper 40s. With light winds and
mainly clear skies across the northern tier, some patchy frost
cannot be completely ruled out.

Center of 1025mb sfc high is parked right overhead by 12Z
Saturday, ensuring the break in the rain continues into the
first weekend of June. Look for max temps to rebound a bit on
the last day of May with highs staying near/below climo. Another
relatively cool night with lows in the 40-50F range.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Models diverge with the amplitude of a shortwave trough moving
through the region late Saturday night into Sunday. This feature
will bring the next chance of showers and thunderstorms to
central PA.

Longer range guidance shows multiple shortwaves moving through
the region into the middle of next week bringing renewed chances
for showers and storms, but confidence in the timing of these
features is low.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
The stronger convection from earlier in the day has mostly
diminished across the region. Very little instability remains as
the sun sets this evening. A few showers still remain and will
continue to slowly drift south and east through the early
evening along the track of the surface low, but visibility
restrictions and lighting from storms are not likely.

Guidance suggests lowered vsbys/cigs at BFD/JST overnight into
Thursday due to patchy fog, which seems plausible given
increased low- level moisture, light winds, and potential for
some clearing skies after 02z. The main uncertainty at this time
remains how quickly clouds clear out, which could limit fog
potential across the western highlands. Recent guidance does
suggest an earlier clearing time, so have outlined IFR/LIFR
restrictions with some added uncertainty with regards to timing.

Conds will improve to VFR areawide by mid-late morning Thursday
as high pressure builds overhead. A sct-bkn cu deck is expected
to develop in the afternoon. Northerly winds will gust up to 20
kts in some areas Thu afternoon as the area dries out.

Outlook...

Thu-Sat...Predominantly VFR.

Sun-Mon...Showers and thunderstorms possible.

&&

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

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Dangelo/Steinbugl/Bauco
SHORT TERM...Steinbugl/Bauco
LONG TERM...Colbert/Bauco
AVIATION...Colbert/Bowen