Harrisburg, Pennsylvania 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

638
FXUS61 KCTP 040813
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
413 AM EDT Mon May 4 2026

.WHAT HAS CHANGED...
* Lowered dewpoints by a few Deg F below NBM with deep vertical
  mixing up to around 7 kft AGL and significant drying aloft
  this afternoon.

&&

.KEY MESSAGES...
1) Temperatures trend much warmer today and Tuesday, ahead of a
system that will bring widespread showers and thunderstorms for
Wednesday and Thursday.

&&

.DISCUSSION...
KEY MESSAGE 1: Temperatures trend much warmer today and Tuesday,
ahead of a system that will bring widespread showers and
thunderstorms for Wednesday and Thursday.

Sfc high pressure has drifted east of the Carolina Coast and the
moderately tight pressure gradient across the Mid Atlantic
Region and Lower Great Lakes will support a gusty southwesterly
breeze. Even with the advection of slightly higher dewpoints
into the Commonwealth the significant rise in temps will equate
to similar or just slightly higher min RHs today relative to
Sunday.

High temperatures jump into the 60s and 70s this afternoon with
the crest of this current warmup occurring Tuesday as a
moderately gusty southwesterly flow is sustained  out ahead of
the next, slow- moving cold front, and temps start out the day
Tuesday some 10-15 deg F higher than this morning thanks to the
breeze and more cloud cover.

In fact, we could see some highly infrequent, nocturnal
convection across the NW Mtns and perhaps even as far south as
RT 211 in the Laurel Highlands as the nose of a strengthening
Wswrly  LLJ advects some modest MU CAPE of over 500 J/KG across
approximately the SW half of PA tonight/early Tuesday.

A few locations across south-central PA may even push the 80
degree mark Tuesday afternoon. Scattered-numerous showers will
impact the region (mainly the NW 1/2 of PA) on Tuesday,
especially across northwest PA. The higher chance for showers
and thunderstorms looks to be on Wednesday and Thursday ahead of
a slow-moving cold front.

Temperatures once again turn cooler behind this front for late
in the upcoming week, with potential frost/freeze concerns
developing. Medium range guidance indicates showers mixing with
or falling as wet snow across the Northern Mountains and Laurel
Highlands late Wed night through Friday.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
06z update... Confidence remains quite high (90+%) in
VFR/unrestricted conditions through 00z Tuesday.

Transient low level wind shear possible in northern TAF sites as
lower-level jet builds in. BFD may see brief intervals of 35kts
LLWS in the 09Z-11Z timeframe, UNV and IPT may see 30kts.
Confidence is not high enough to include in TAFs as magnitude is
not expected to cross 35kts for significant periods of time.

Low-level winds emanate from the S and SW and become gusty (up
to 20-25 kt) by midday Monday as high pressure moves offshore
and convective mixing brings down stronger winds.

Outlook...

Tue...SHRA/TSRA becomes more widespread from NW to SE;
restrictions possible.

Wed-Thu...SHRA/TSRA continue; restrictions likely.

Fri...Scattered SHRA remains possible, restrictions possible

&&

.CLIMATE...
Multiple low temperature records were set or tied across
central Pennsylvania for May 3rd:

Altoona observed a low temperature of 31 degrees, breaking the
previous record of 32 degrees set in 1957.

Johnstown observed a low temperature of 29 degrees, which ties
the previous record of 29 degrees set in 1941.

&&

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

&&

$$

WHAT HAS CHANGED...Lambert/Bauco
KEY MESSAGES...Lambert/Bauco
DISCUSSION...Lambert/Bauco
AVIATION...Jurewicz/Lambrech
CLIMATE...Beaty/Lambrech