119
FXUS61 KPBZ 030543
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
143 AM EDT Thu Jul 3 2025

.SYNOPSIS...
Valley fog is possible tonight, with isolated thunderstorms
expected Thursday afternoon, with dry weather for the Fourth and
Saturday. Temperatures will gradually climb into the lower 90s
through the weekend into the start of next week.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
KEY MESSAGES:

- Patchy valley fog tonight.
---------------------------------------------------------------

Any lingering clouds will dissipate with the loss of mixing this
evening and early tonight, giving way to mostly clear skies and
light to calm wind. This efficient cooling might suggest lows
around average, dropping to near dewpoint observations in the
lower 60s and upper 50s. As temperatures approach dews, fog will
be possible; most likely in river valleys and sheltered
surrounding areas. Fog will burn off after sunrise.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH FRIDAY NIGHT/...
KEY MESSAGES:

- Slight chance for showers and thunderstorms Thursday, mainly in
the northern PA counties.
- Dry and sunny weather for the Fourth.
- Temperatures a few degrees above average.

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

A trough and its associated surface cold front, is expected to track
southeastward across the Upper Ohio Valley region on Thursday. Very
dry air aloft will likely inhibit updraft growth, limiting the
chance for showers and thunderstorms. Still, isolated thunderstorms
are possible (30%-45% chance) over the following PA counties:
Forest, Venango, Butler, eastern Mercer, Clarion, Jefferson,
Armstrong, Indiana, and northeastern Allegheny.

Given the dry air aloft and substantial surface-based CAPE, there
will be a conditional threat for downbursts IF more robust updrafts
are able to develop. Machine learning guidance does marginally
support a low-end severe weather threat as well. Will continue to
monitor this threat. Any convection will quickly diminish after
sunset with loss of daytime heating.

Afternoon temperatures forecast to be few degrees above seasonal
average, while temperatures Thursday night may drop a degree or two
below average.

Beautiful weather looks to be in store for the Fourth with sfc high
pressure and ridging overhead. Models do develop a few isolated
diurnal showers and thunderstorms in Ohio, but this is likely to
remain west of Coshocton and Muskingum counties. Otherwise, the
forecast looks great for outdoor plans and evening fireworks.
Temperatures will run no more than 5 degrees above average under
partly to mostly sunny skies, and heat indices in the mid to upper
80s outside of the ridges. Temperatures fall back to near-normal
Friday night.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
KEY MESSAGES:

- Dry on Saturday.
- Increasingly hot and humid with shower and thunderstorm
  chances returning Sunday and Monday.

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

Sfc high pressure and ridging aloft should promote mainly dry and
warm weather again Saturday. Rising heights and southerly flow
should boost area highs into the upper 80s to near 90F. NBM probs
for 90F are highest across eastern Ohio, northern West Virginia
panhandle, and the Pittsburgh urban heat island (70%-85%). For other
areas, probabilities are generally around 35%-45% or lower in the
higher elevations.

The ridge is then progged to flatten Sunday into early next week,
with westerly flow aloft across the Upper Ohio Valley region.
Disturbances embedded in this flow aloft are expected to
periodically cross the region, with daily shower and thunderstorm
chances returning.

On Sunday and Monday, 500 mb heights are still expected to approach
590 dam, bringing hot and humid conditions across the region. High
probability (70%-90%) of maximum temperatures at or above 90 degrees
on Sunday and Monday. The chances of Heat Advisory criteria remain
low as heat indices remain in the 90s.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
As expected many clouds have dissipated and left us with largely
clear skies and VFR prevailing at all ports. VFR is expected to be
the rule today, with few exceptions in fog this morning. Fog is
expected to be less widespread than Wednesday with the most likely
impacts being east of Pittsburgh. Have maintained the mention for
LBE and lowered MGW from prevailing to a TEMPO for any MVFR/IFR
impacts in fog this morning.

Valley fog impacts are expected to wind down by 13z, with scattered
to broken VFR cu replacing it. Isolated storms may pop along a cold
front dropping south through the region this afternoon but POPs
remain rather low. DUJ maintains the greatest chance to see storms
and have continued their PROB30. FKL and LBE would be the next most
likely impacted ports but chances are low enough to preclude TAF
mention.

Light and variable wind overnight will take on more of a
northwesterly direction under 10 knots by late morning.

Outlook... VFR is expected through Sunday as high pressure moves
across the region, with precipitation chances and isolated
restrictions potentially returning Monday.&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.

&&

$$

SYNOPSIS...Rackley/Lupo
NEAR TERM...Milcarek
SHORT TERM...Rackley/Lupo
LONG TERM...Rackley/Lupo
AVIATION...AK