645
FXUS61 KCTP 031905
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
305 PM EDT Thu Apr 3 2025

.SYNOPSIS...
A warm front has pushed into Central PA, but a cold front will
very quickly follow, pushing through Central Pennsylvania this
afternoon and evening, stalling out of just south of the region
tonight and Friday. A wave on the stalled front will lift up the
Ohio Valley and across Pennsylvania this weekend.

&&

.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
Wind picking up everywhere as we mix higher. JST is gusting into
the m30s regularly. 8H jet is 50KT there. The dewpoints rose
into the 60s in the west and south of the turnpike over SErn PA,
but have mixed lower a bit in the west. Much more humid than the
10F dewpoint yesterday morning in State College. The moisture
and some breaks in the clouds are allowing convection to pop in
the NW. The cold front has just entered McKean Co, headed to a
town near you (unless you are in the NW half of Warren Co where
it`s already past).

Expect the convection over wrn PA to grow. But, just how
deep/strong that it CAN grow is the question. Lots of high and
mid clouds overhead. Model soundings indicate more than one
capping inversion (of varying strengths). This is likely the
reason that the convection has been shallow thus far. Best
instability is in the SW before the CFRONT moves thru during
the evening. CAMs do not light up the front so much, but do
bring the convection over the coal fields of KY and WV into the
local area.

SPC has nudged the SLGT risk area a little farther south than
earlier progs, and removed it entirely from our CWA. However,
there is still a MRGL risk into the evening, with the strong
(55-65KT) LLJet over the srn half of the CWA. The fronts (warm
and cold), lingering boundaries from earlier precip/temp diffs,
and of course the terrain may all provide foci for convection
to initiate. The cold front won`t quite make it to THV/LNS by
midnight. But, it should clear the rest of the area by then.

&&

.SHORT TERM /MIDNIGHT TONIGHT THROUGH FRIDAY NIGHT/...
Front will be stalled to our south tonight and highest PoPs
ramp up later tonight as overrunning combines with steep lapse
rates and instability aloft over our srn tier. MRGL risk remains
over southern PA tonight into Thursday. Precip later tonight
will be back into the cold air, but we still cannot rule out a
stronger storm given better moisture and instability nearby to
the south, but that threat is on the low side.

Mins tonight s/b close to 40F north but remain in the m50s far
southeast tonight. The high pressure over central Canada and the
Upper Great Lakes will slide eastward and keep a drying nrly
flow going until Fri night when veers to the SE. The sfc front
should be languishing over MD-WV/nrn VA into Sat. Multiple waves
of low pressure/shortwave troughs will roll eastward along it,
and give us many chcs for rain/thunder. The first of which will
be later Fri night. Have ramped up PoPs thru the night to 100s
for most of the area by Sat AM. The SE flow will again bring
plentiful low clouds and areas of drizzle to the eastern cos.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Waves of low pressure riding east/northeast along the stalled
to lifting frontal boundary will result in periods of soaking
rainfall (with some embedded convective elements) this weekend.
Latest WPC/NBM QPF fcst projects the heaviest rain (0.50-1.50")
over the western and northern Alleghenies with <=0.50" across
the south central ridges into the lower Susquehanna Valley
(where it is needed the most).

There is a broad consensus among the medium range operational
and ensemble guidance that the primary cold front (and
associated band of rain) slides to the southeast of the area by
early Monday. Model data favors a period of dry weather during
the day on Monday with noticeably cooler max temps (~55F) over
the southern tier of CPA (-10 to -15 degrees cooler vs. Sunday).

The focus will shift to a cold upper trough digging through the
Great Lakes into the Northeast Monday night into Tuesday. This
feature should bring unseasonably cold temps (-15 to -25F below
the historical average) and unsettled wx with rain/snow showers
likely along with some potential for strong blustery wind gusts.
The colder cyclonic/NW flow should linger snow showers downwind
of Lake Erie over the Allegheny Plateau into Tuesday night and
possibly Wednesday morning. Temps should hit a nadir Tuesday
into Tuesday night.

There are some long range model signals that suggest upper
level troughing will reload (with potential for a closed low to
move deep into the southeast US) into the second half of next
week. This pattern would favor a continuation of temps below the
historical average for the second week of April. There may also
be an opportunity for frost/freeze conditions as the spring
growing season gets underway in the Lower Susquehanna Valley.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
A couple of passing rain showers mainly in the northern and
southern tier airspace through the afternoon, but overall we
expect a lull in precip through 04/0000UTC. Flight cats have
improved to MVFR/VFR and expect these conditions to hold into
tonight. Wind gusts 20-30kt from 220-250 degrees are expected
through the afternoon with downsloping flow on the eastside of
the Allegheny Front favoring VFR cigs.

Another round of rain with some potential for embedded
thunderstorm clusters is forecast later tonight into early
Friday morning primarily focused over the southern 2/3 of the
central PA airspace.

Outlook...

Thu...MVFR poss in widespread rain showers. TSRA poss, mainly S.
CFROPA aftn/eve.

Fri...MVFR cigs and visby expected, mainly S.

Sat-Sun...Widespread showers; impacts likely.

Sun...Lingering rain/snow showers; restrictions poss especially
N/W.

&&

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

&&

$$

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