919
FXUS61 KCTP 050033
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
833 PM EDT Sat Apr 4 2026

.WHAT HAS CHANGED...
* Pushed back the primary threat for scattered strong to severe
  thunderstorms by a few to several hours later today and this
  evening and greatly reduced pops through the mid afternoon
  hours.

&&

.KEY MESSAGES...
1) Numerous showers and thunderstorms will affect Central PA
late today and tonight. Some may be severe, especially across
the northwest third of CTP CWA.

2) Cold front moves through later tonight and early Easter
Sunday. Much colder next week but warming up again by week`s
end. Light snow likely across the northern tier Monday/night.

&&

.DISCUSSION...
KEY MESSAGE 1: Numerous showers and thunderstorms will affect
Central PA late today and tonight. Some may be severe,
especially across the northwest third of CTP CWA.

A slowly northward moving warm front extended from near Olean
New York, southeast to near Selinsgrove and Allentown this
midday hour.

A few showers were developing along this airmass boundary
as warmer and moist air overrides it from the southwest.

A deg C or two of mid level WAA from the SW (with a several
more hour period of weak mid-level lapse rates) and a neg tilt
mid-upper level ridge (with slightly confluent flow aloft,
beneath the right exit region of jet max approaching from the
midwest) will result in a mainly dry and very warm afternoon
across much of Central and Southwestern PA.

Temperatures will peak in the 70s to low 80s with an
increasing, moderately gusty southerly breeze of 15-20 mph.
These temps will be close to record maxes in the south (see
Climo section below).

Some showers will continue across the North-Central and Endless
Mountains regions of the state this afternoon where
temperatures will be a bit cooler in the 60s.

More showers and thunderstorms are expected tonight in the very
warm and humid airmass along and ahead of a cold front.

The cold front and a band of rain and possible thunderstorms will
push through late tonight and Sunday morning.

Dewpoints will also be rising as the wind becomes more-
southerly through the day.

High res models continue to suggest that some of the first TSRA
initiation may take place across the Scent Mtns (between
20-21Z), within an area of pooling moisture and PWATs AOA 1.4
inches. However, the storms in the south-central mountains will
be displaced from the best shear, but should have some of the
best instability/CAPE of the day.

These late afternoon/early evening storms expand and move
northward through all of the central mountains. That should get
them into some of the better shear, but also put them into the
colder/more stable air.

As this convection moves over the warm frontal boundary, it
could have some enhanced low level shear/helicity and have more
potential to make a strong, rotating updraft and perhaps a risk
for a tornado. Heavy rain is also possible, and may lead to
isolated instances of minor flooding where several heavy SHRA/
TSRA northeast.

A second round of storms is expected to flare up in the NW where
a strong cold front will be moving in during the late evening
hours. Some storms in the warm sector/ahead of the cold front
could have supercellular characteristics, but the main threat
will be wind damage. The front will be the main focus for severe
weather in the evening and early nighttime. Storms reach Warren
Co just after 00Z and Coudersport/Clearfield by midnight. The
showers/storms along the front continue eastward at a slow
clip, and may not get to Harrisburg until 12Z. But, they`ll only
spend 2-3 hrs there before leaving the CWA around noon on
Easter.

         ---------------------------------------

KEY MESSAGE 2: Cold front moves through later tonight and early
Easter Sunday. Much colder next week but warming up again by
week`s end. Light snow likely across the northern tier
Monday/night.

The cold advection behind the cold front is going to make temps
fall slowly but steadily throughout the day over all but the
Lower Susq (where downsloping/adiabatic warming and more
insolation will likely compensate for the upstream cold
advection).

Temps may peak in the Lower Susq in the mid morning and fall
several deg or more after the rain starts, but should rebound
back by 2-4 deg F (possibly reaching the mid morning high).
Afterward, the cold air deepens and llvl cold advection
strengthens enough to resume the slow drop in temps in the mid
to late afternoon.

Mid aftn temps will be in the L40s NW and ~60F in the SE. Sfc
low will pass way to our N, but the center of the cold dome will
slide to our S. Still, 8H temps drop to -8C along the NY
border, and -4C in the S. Maxes on Monday will have some bust
potential. Lowered temps by 2-3 deg for now with more weighting
on the Northern and Western Mtns where rain/snow showers will
be more numerous.

Blended guidance mean maxes of 40F N and U50s S seems ripe for
a bust with such cold temps aloft. Wild cards include:
we may not mix to 8H that day, the April sunshine will try to
do it`s best, and downsloping in the Lower Susq.

A Clipper-like system dives across the Upper Great Lakes and
into NY/PA later Mon/Mon night. After that, the flow favors
lake-effect showers. The temps will be cold enough across the
nrn tier of counties to allow it to be mostly snow anytime by
the middle of the day. Some accums of <=1" should occur on the
hills of the north, but that will be along a 48-hr stretch. Some
snow may mix into the mostly-rain showers in the central mtns
and Laurels Mon night. Dry and cold Tues with low RHs
(m20s-30s), and a little warm up on Wed will result in even
lower RHs (20s).

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...

Afterward, scattered SHRA/TSRA will impact the Scent Mtns and
moving/expanding NE across the Middle Susq Valley this evening.

PROB30s for -TSRA are maintained for these sites, with HREF
mean SBCAPE values around 1000 J/kg suggesting sufficient
instability for thunderstorm development given the moisture/lift
in place.

Flight conditions will likely deteriorate again after 00Z  as
low-level moisture transport increases ahead of an approaching
cold front. Widespread MVFR ceilings are probable (60-70%), with
IFR ceilings being possible as well (30% chance). Moreover, a
backdoor cold front is expected to nose into the Lower
Susquehanna Valley (KMDT/KLNS), and potentially reach as far
west as KUNV by around 03Z, which could reinforce flight
restrictions. While instability will be waning overnight, HREF
mean MUCAPE values of around 100 J/kg suggests isolated thunder
may be possible with the frontal passage. A PROB30 for -TSRA was
included at KBFD between 05-08Z, given that MUCAPE values
further diminish thereafter. LLWS is also a concern overnight as
850 mb winds increase to 40-50 kts over a decoupled boundary
layer, with LLWS mentions included at KBFD/KMDT/KLNS at this
time.

Outlook...

Sun...Restrictions possible with showers and thunderstorms
ahead of and along a strong cold front.

Mon...Breezy and cooler with MVFR N/W and VFR elsewhere, with
scattered rain/snow showers possible.

Tue...Mainly VFR with a few rain/show showers.

Wed...VFR.

&&

.CLIMATE...
Record high temperatures were set at the following locations on
April 4th:

Harrisburg set a record high temperature of 83 degrees,
breaking the old record of 82 degrees set in 1999. A continuous
weather record has been kept in Harrisburg since 1888.

Bradford set a record high temperature of 76 degrees, breaking
the previous record of 72 degrees set in 1981.

Altoona tied a record high of 80 degrees, where the previous
record was set in 1950.

&&

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

&&

$$

WHAT HAS CHANGED...Lambert/Dangelo
KEY MESSAGES...Lambert/Dangelo
DISCUSSION...Lambert/Dangelo
AVIATION...Lambert/Teare/RXR
CLIMATE...Beaty