Latest Area Forecast Discussion for Central PA

Here is the latest Area Forecast Discussion for Central PA

This text statement is the latest forecast reasoning from the NWS in State College, PA

See the links at the bottom of the page for previous issuances/versions of the statement as well as our other text statements.

216
FXUS61 KCTP 151912
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
312 PM EDT Wed Apr 15 2026

.WHAT HAS CHANGED...
* Tweaked timing on convection this evening

&&

.KEY MESSAGES...
1) Severe threat over the northwest part of the CWA this
evening. Much lower threat Thurs.

2) Dry, windy conditions Thurs may lead to a increased risk of
rapid wildfire spread.

3) Summer-like heat and humidity into Thursday.

4) Cold front brings precipitation and relief from summer heat
late this weekend.

&&

.DISCUSSION...
KEY MESSAGE 1: Severe threat over the northwest part of the CWA
this evening. Much lower threat Thurs.

Morning convection helped to raise dewpoints slightly, but they
have started to lower with deeper mixing in between shots of
forcing. Gusty SWrly wind is topped by Wrly flow in mid levels.
The forecast soundings/profiles do support CAPE rising to
1000-1500 J/kg this afternoon and evening over the NW. Forcing
from a short wave trough will arrive late in the day, and help
flare some deep convection. Shear is close to 45KTs at BFD
around 6 PM. Most num guid develops storms over nrn OH and
slides it into Warren Co around 5 PM. Mid level flow of 60+ KTs,
too. Fast moving storms with multi-cellular or even super-
cellular mode are expected. Coverage is expected to increase
through 8 or 9 PM before struggling to hold together and push
too far S of I-80. An isolated storm or two could pop S of
there, but we`ll have lots of CINH to erase for that to happen.

The storms should start to wane as we lose heating and the
trough passes to the east late this evening/early tonight. The
threat for severe wx should be done by 10 or 11 PM. A weak
boundary will likely lay out W-E right thru the middle of the
CWA as they die off. The wet areas will probably develop some
fog overnight.

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

KEY MESSAGE 2: Dry, windy conditions Thurs may lead to a
increased risk of rapid wildfire spread.

South of the boundary mentioned above will be dry as the drought
conditions beget more drought for the southern third of the CWA.
Dewpoints will drop into the lower 50s or even upper 40s over
the southern half of the CWA, especially in the Laurels and
south-central mountains. At the same time, the heat of Wed will
be replicated. The resulting RHs will get into the 20s over the
s-c mtns. Gradient winds will be 10-15 MPH with some higher
gusts during the afternoon there, too. While the fine fuels are
not dry enough to warrant a fire weather watch/red flag warning,
the wind and low RH may warrant a mention more than here in the
discussion.

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

KEY MESSAGE 3: Summer-like heat and humidity into Thursday.

The main, wavy front will be laying out to our north for the
next day and a half. Deep mixing here in the warm sector has
already pushed temps well above normal, with 3 PM temps already
near records in many spots and even higher than normal high
temperatures in July. Expect this to repeat Thursday (tomorrow).
The possibility of clouds and some morning fog across the nrn
tier could hold them just a deg or two below what we see right
now. The earlier boundary

Additional showers/storms are expected Thurs in just about the
same timing and location as this evening. The mid-level winds
will not be as strong, though. So, the threat for severe weather
is not as great nor as widespread as this evening - staying
confined to the far NW. SPC MRGL is appropriate.

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

KEY MESSAGE 4: Cold front brings precipitation and relief from
summer heat late this weekend.

Low pressure rolls to the east along the main front to our N
Thursday night. Fri looks mainly dry and 5-10F cooler, but
Saturday holds the next chc for SHRA/TSRA. The bigger change
will come later in the weekend as a significant cold front
ushers in much, much colder air. In fact, Monday night could
hold a freeze or frost for most of the CWA. New fcst takes
everyone down AOB 32F. Monday will be 10-12F colder than Sunday
as the big high pressure area floats in from central Canada.

Day 6-7 look warmer again as we get into a SW flow due to the
high sliding rather quickly east.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Current satellite as of 18Z/2PM EDT outlines partly cloudy
skies across W PA ahead of showers and thunderstorms in western
Ohio approaching the forecast area. These showers and
thunderstorms will continue to track eastward this
afternoon/evening with increasing chances of showers and
thunderstorms across the northwestern half of the airspace
(BFD/IPT/UNV) between 22Z Wednesday through 06Z Thursday. Recent
HREF/NBM/RAP model guidance continues to highlight BFD as the
airfield under the gun for TSRA mentions, mainly between 22Z
Wednesday and 02Z Thursday, which could bring lower visibility
and ceilings in this timeframe. At this time, model guidance
tends to keep everything above MVFR thresholds; however, cannot
rule out brief drops towards MVFR/IFR thresholds in heavier
thunderstorms this evening. Strong-to-severe thunderstorms will
be most likely at BFD in the aforementioned timeframe, which
could bring gusts above 40kts so radar trends will need to be
monitored closer to the time for this threat. Further south,
model guidance has trended back on precipitation mentions which
lines up fairly well with recent GLAMP model guidance, thus have
nixed mentions of SHRA/TSRA south of a IDI-UNV-HZL line in the
18Z TAF package.

Between 06Z-12Z, TSRA threat decreases due to lack of
instability; however, could continue to have some lingering SHRA
at BFD which could bring MVFR ceilings/visibilities with
relatively low (~20-30%) confidence. Have outlined this
potential with a scattered low-level deck; however, there is a
lower bound solution where this low-level deck trends slightly
lower in future TAF packages. After 12Z, widespread VFR
conditions are progged by the bulk of model guidance so have
penciled these in with moderate-to-high (~60-80%) confidence
through 18Z Thursday. Main aviation concern between 12Z-18Z
Thursday will be the presence of breezy (20-25kt) northwesterly
winds across all of central PA`s airfields.

Outlook...

Fri...Restrictions possible early, then improving to VFR in the
afternoon.

Sat-Sun...Restrictions in SHRA possible, transition to SHSN
across higher elevations overnight Sunday night into Monday
morning.

Mon...Lingering SHSN possible early across N PA with
restrictions possible; otherwise, dry conditions with VFR
prevailing.

&&

.CLIMATE...
Record high daily maxes and mins are possible this week as
summerlike warmth visits the region. Here`s a look at the
records as they stand right now, with a * indicating that the
forecast is equal to or greater than the record.

Record High Daily Max / Daily Min...

For Harrisburg:
April 15: 87* (1941) / 61* (2023)
April 16: 89 (2002) / 63* (1941)
April 17: 91 (2002) / 60* (2002)

For Williamsport:
April 15: 86 (1994) / 57* (2023)
April 16: 90 (2002) / 55* (2023)
April 17: 91 (2002) / 58* (1896)

&&

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

&&

$$

WHAT HAS CHANGED...Dangelo
KEY MESSAGES...Dangelo/Colbert
DISCUSSION...Dangelo/Colbert
AVIATION...Beaty/Lambrech
CLIMATE...Colbert

Forecaster's
Discussion: