499
FXUS61 KCTP 031136
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
736 AM EDT Thu Apr 3 2025

.SYNOPSIS...
A cold front will push through Central Pennsylvania today before
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 6 PM THIS EVENING/...
Dying squall line has just crossed the Allegheny crest and the
line has weakened as it approaches Altoona. Local gusts GT 45
mph still possible through 6:30 AM, but with more stable
stratification and dewpoints in the 40s east of the mountains,
the threat for strong gusts is decreasing early today, and we
are not anticipating widespread impacts along and east of the
Laurels given observed tendency and line moving into more
stable air with lower dewpoints in the 40s east of the
mountains. Farther east, stability remains high while llvl
moisture from persistent southeast flow results in plenty of low
clouds and fog blanketing the ridges this morning. Temps steady
or slowly rise through dawn, rising into the 50s almost
everywhere and near 60F in the Laurels at sunrise.

The baroclinic zone sags ESE across western and central PA this
morning with highest POPs now through 15z across northern and
central areas, and lingering through 18z for the Laurel
Highlands as the front stalls south of the Mason Dixon line
later on. Main question for today is whether recovery is allowed
to occur in a sheared and mostly cloudy environment. Far
southeast may stand the greatest chance for storms as the
boundary remains nearby and binovc may provide enough sfc
heating to initiate. Most CAMs downplay this potential however,
and we are leaning in this direction as well at this time.

&&

.SHORT TERM /6 PM THIS EVENING 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 to SLGT risk
remains over central and southern PA tonight into Thursday, but
the SLGT has been progressively shaved and we are leaning more
towards the MRGL category with this activity given cap and
initial stability. Still cannot rule out a stronger storm given
better moisture and instability nearby to the south, but that
threat is on the low side.

Temps will rise into the 70s for most of central and southeast
areas, with upper 70s likely across the far south, as 8H temps
get into the mid teens. Mins tonight drop to the lower 40s north
but remain in the mid to upper 50s far southeast tonight.
EPS/GEFS continue to indicate fair and drier weather for most of
the day Friday before moisture returns Friday night and Saturday
across central PA. Best chance for rain Friday will be over the
south/southwest invof the stationary boundary along the edge of
the deeper layer moisture extending from the OH Valley.
Highs on Friday will generally be in the mid 50s to mid 60s
with cloudy skies south and perhaps a few breaks in the clouds
across the northern tier.

Showers increase aft 00z Saturday and may favor northern areas
as the front makes a jump to the north again. Southeast flow
will again bring plentiful low clouds and areas of drizzle
farther south and east, so despite lower POPs it will be rather
cloudy and dank throughout Fri night into Saturday morning.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
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 slides to the
east of the area early next week as a strong surface high moves
into the Central US and finally puts an end to the onslaught of
rain across the Mississippi and Ohio Valleys. After the cold
front sweeps through, anomalous upper level troughing will
build into the northern Mid Atlantic and Northeast states next
Monday- Wednesday. This pattern will be accompanied by high
confidence in below normal temperatures and blustery
conditions. The colder cyclonic/NW flow should also favor
scattered rain/snow showers downwind of Lake Erie over the
Allegheny Plateau.

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 /12Z THURSDAY THROUGH MONDAY/...
South-southeasterly flow will maintain an influx of moisture
beneath a thermal inversion this morning, with LIFR cigs in the
lower Susq, IFR cigs at IPT, and MVFR cigs at UNV. The western
airfields have seen the best conds with downsloping flow on the
leeward side of the Allegheny front.

The other concern through the morning hours will be LLWS as a
50 to 60 knot low-level jet moves in. LLWS will wane this
afternoon as the low level jet pulls away.

Morning convection is quickly losing steam as it moves
northeast into more stable air. Guidance continues to suggest a
break in precipitation during the late morning and early
afternoon before another round of convection initiates across
the southern half of PA with the passage of the cold front, with
precipitation lingering into Thursday night as the most
favorable upper dynamics pass overhead.

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...DeVoir/Dangelo
NEAR TERM...DeVoir/Dangelo/Banghoff
SHORT TERM...DeVoir/Dangelo/Banghoff
LONG TERM...Steinbugl/Banghoff
AVIATION...Colbert/Bowen