029
FXUS61 KCTP 041945
AFDCTP

Area Forecast Discussion
National Weather Service State College PA
345 PM EDT Fri Jul 4 2025

.SYNOPSIS...
* Incredible weather for Independence Day with plenty of sun,
  seasonable temperatures and comfortable humidity
* Warming trend into the first weekend of July with hot/humid
  conditions expected to peak Sunday and Monday
* Isolated t-storms possible downwind of Lake Erie and over the
  Allegheny/Laurel ridgetops Saturday afternoon and evening;
  daily chances for showers and t-storms next week

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Spectacular weather continues for the rest of this Independence
Day across Central PA with below normal Precip Water of just
0.4 to 0.7 of an inch helping to provide nearly cloud free skies
and excellent vsby for a Summer day.

Mid-Late afternoon high temps between 75F (Northern and Western
Mtns) and 80-85F (Central and Southern Valleys) are within +/-
3 degrees of 4th of July climo. Continued to lean on the low-
end of the guidance for dewpoints which drops minRH AOB 40% in
most areas.

Good viewing conditions for fireworks tonight with mainly clear
to partly cloudy skies and overnight low temps in the 50-60F
range. That said, very light wind and low level nocturnal
stability should impact/limit smoke dispersion.

Some fog is also possible again late tonight/early Saturday
throughout the deeper valleys in Northern PA similar to this
morning.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
Warming trend expected over the first weekend of July along with
an uptick in humidity/dewpoints as we progress through the day
Saturday.

Max temps on Saturday are +3-8F warmer vs. this Friday afternoon,
but dewpoints/humidity levels remain generally
tolerable/seasonable in the 60-65F range across much of the
region.

Humidity ramps up to more uncomfortable level on Sunday by
adding another 2-4 degrees to max temps (mid 80s to low 90s)
with Tds climbing to between 65-70F in the central and eastern
valleys. In other words, hot and humid by the end of the holiday
weekend with min temps also making a series of higher-lows.

In terms of precip, there is an emerging signal in the HREF for
isolated to scattered diurnal showers/t-storms downwind of Lake
Erie (as the eastern edge of the Lake Erie Breeze interacts
with the increasing LLVL moisture) and over the ridgetops along
the Allegheny Plateau and Laurels.

Will maintain low POPs across the NW mtns Saturday afternoon
and evening which also lines up well with SPC general/non-severe
thunderstorm outlook area.

Sunday still looks rain-free for now as CPA will be in the
squeeze play subsidence zone between approaching cold front to
the west and potential tropical/subtropical depression near the
Carolina coast. Beneath the axis of the Upper Level Ridge
shifting east across the Commonwealth Sunday, mid level temps
will warm to around +10C, likely capping most or all deep
convection, except for perhaps one or 2 isolated cells over the
ridgetops.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
PoPs increase into Monday and Tuesday as a relatively weak
northern stream upper level trough arrives and taps into some
tropical moisture off the East Coast.

Quite muggy overnight lows in the mid 60s to low 70s (NW to SE)
Sunday night and Monday night.

Very warm weather will continue on Monday with highs in the mid
to upper 80s. Temps will fall a few degrees into Tue. PoPs drop
into the 20-40 pct range on Wed as heights briefly rise over
the area, before the PoPs rise again Thursday with the approach
of another shortwave trough.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
Excellent flying conditions for the rest of this 4th of July.

Aside from some very thin cirrus/high level smoke from Canadian
wildfires, skies are expected to remain clear and winds will be
light and variable. Dry conditions and VFR will prevail
throughout the rest of the day and into tonight.

There will again be the possibility for some early morning
valley fog across the airspace, but impacts to airfields is
expected to remain limited. Overall confidence in fog
development remains low.

Outlook...

Sat-Sun...AM fog possible; otherwise VFR.

Mon-Tue...Potential for showers and thunderstorms.

&&

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

&&

$$

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