847
FXUS61 KCTP 291731
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
131 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 /THROUGH TONIGHT/...
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 /THURSDAY 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 TUESDAY/...
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 /18Z WEDNESDAY THROUGH MONDAY/...
(V)LIFR conds across the western highlands (BFD/JST) will
continue for the next hour-two before giving ways to a brief
period of VFR conditions. A period of showers this morning is
likely to get to JST/BFD by 14Z Wednesday with less confidence
further east so have left mentions out at this time. Within
these showers, low-end VFR seems like the most likely options
although cannot rule out a brief drop towards MVFR vsbys/cigs.

Later this afternoon, higher coverage of SHRA is expected to
develop with showers and thunderstorms expected. Brief
visibility restrictions are possible in any heavier showers and
storms (see below) with cigs borderline MVFR/VFR based on recent
model guidance. Elevated CAPE does indicate higher chances of
TSRA as these showers progress across the area today. This TAF
package has tightened up some of the TSRA mention timing
although some uncertainty still exists on exact coverage.

Guidance indicated towards lowered vsbys/cigs at BFD/JST
overnight into Thursday, which seems plausible given increased
low-level moisture, light winds, and potential for some clearing
skies. 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.

Outlook...

Wed Night-Sat...Predominantly VFR.

Sun...Showers and thunderstorms possible.

&&

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

&&

$$

SYNOPSIS...Steinbugl
NEAR TERM...Steinbugl/Bauco
SHORT TERM...Steinbugl/Bauco
LONG TERM...Colbert/Bauco
AVIATION...NPB