410
FXUS61 KCTP 301849
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
249 PM EDT Thu May 30 2024

.SYNOPSIS...
Canadian high pressure will build southeast into Pennsylvania
Friday and Saturday. The high will pass off the East Coast by
late this weekend into early next week, then a cold front will
likely traverse the state next Thursday.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Scattered fair weather cumulus are distributed throughout most
of central PA this afternoon with some locally taller buildups
potentially supporting an isolated shower across the central and
south late this afternoon. Most areas will remain dry.

Nearly ideal conditions for radiational cooling are setting up
tonight across the western half of PA, as the upper trough lifts
out and Canadian High Pressure builds in, accompanied by clear
skies, dry air and a calm wind. We continue to lean towards the
cooler guidance (MAV) and close to the 10th percentile NBM mins
which reach the upper reaches of the favorable ranges for frost.
Dry boundary layer, warmer stream temps and fairly warm ground
may preclude frost potential, but collaborated a Frost Advy headline
for my northern tier and NW Mountain counties with BUF and BGM
from ~midnight through 7AM Fri. A large water/air temp
difference of >25 degrees also favors patchy late night fog in
the deep river/stream valleys of the NW Mtns.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
Little changes to the going forecast for Friday and Saturday
with this cycle. Large scale subsidence and low- pwat air
points to abundant sunshine Friday, as high pressure pushes into
the state. Mixing down 850mb temps of around 8C translates to
highs from the upper 60s to mid 70s. Friday night should be
another cool one, as the surface high builds directly over PA,
resulting in clear skies, a calm wind and min temps below NBM
guidance. The airmass in general should be moderating, so expect
readings not quite as cool as tonight.

Upper level ridging is progged over PA by Saturday, as the
surface high slips off of the East Coast, resulting in a mostly
sunny and warmer start to the weekend. GEFS 2m temp anomalies
Sat afternoon are few degrees above climo, translating to highs
of 75-80 over most of Central PA.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
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. PoPs have decreased for Monday, which
now looks like it will be a generally dry day. Chance or greater
PoPs return for Tue-Thu.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
VFR conds prevail today with SCT-BKN fair weather cu. Northwest
winds gusting up to 20 kts will weaken after sunset. Dewpoints
will be quite low tonight, thus expecting mainly clear skies
with very little potential for fog overnight into Friday
morning, except for the deepest river valleys.

Outlook...

Fri-Sat...Mainly clear skies with VFR conditions.

Sun-Mon...Showers and thunderstorms possible.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
Frost Advisory from midnight tonight to 8 AM EDT Friday for
PAZ004>006-010-011-037.

&&

$$

SYNOPSIS...DeVoir/Fitzgerald
NEAR TERM...DeVoir/Fitzgerald
SHORT TERM...DeVoir/Fitzgerald
LONG TERM...Dangelo/Colbert
AVIATION...Martin/Colbert