894
FXUS61 KPBZ 201114
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
714 AM EDT Wed Aug 20 2025

.SYNOPSIS...
Scattered shower and thunderstorm chances can be expected with
the passage of a weak cold front today. Temperatures will lower
to near normal today before gradually increasing to slightly
above normal by the end of the week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
KEY MESSAGES:

- Cold front and associated upper trough brings scattered
  showers/storms this morning and afternoon.
- Temperatures drop to near normal values.
---------------------------------------------------------------

Ongoing broken clusters of showers and storms will continue to
progress across western PA this morning. Observed CG lightning
is largely confined to areas where latest mesoanalysis shows
MLCAPE values around 500 J/kg, while other areas are limited to
just showers. Latest rapid update hi-res guidance suggests
instability sufficient for thunder should remain confined to
southwest PA this morning, while the band of highest QPF
amounts should stay along and south of the I-80 corridor.

Lows will bottom out well above normal with cloud coverage and
continued low level mixing/turbulence, but highs will be lesser
than observed Tuesday in the wake of the mentioned front.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
KEY MESSAGES:

- Scattered shower/storm chances continue through the afternoon
  and into Thursday with the passage of a front and associated
  upper trough.
----------------------------------------------------------------

Scattered rain chances will decrease in the wake of the front
by this afternoon/evening. All indications are that
precipitation will be widely scattered, with QPF amounts between
0.10" to 0.50" in general. Anomalously high PWATs could though
result in localized areas of higher amounts associated with
deeper convection, so localized flash flooding can`t be
completely ruled out.

Renewed high pressure across the Great Lakes and Ohio Valley should
keep most of the area dry overnight into Thursday. Some weak
troughing could help to initiate a few diurnal showers
Thursday afternoon. With Hurricane Erin to our east, flow will
be out of the northeast on Thursday.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
KEY MESSAGES:

- Above average temperatures return by this weekend
- Precipitation chances return Saturday into Sunday with a
  passing cold front
- Cooler weather begins next week.
-------------------------------------------------------------------

Riding over the Ohio River Valley will result in dry conditions
and warmer conditions towards the end of the week and into the
weekend before a passing cold front and an upper- level trough
increase chances of precipitation Saturday into Sunday. Overall,
rainfall amounts continue to look relatively low (30-40% of
>0.25" for counties along the Appalachian ridge-line and less
than 25% chance west of Pittsburgh).

Generally high confidence exists in persistent eastern CONUS
troughing by early next week. This should keep temperatures
below average during the first half of next week.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
The passage of a weak surface front and upper saggy trough will
favor isolated showers this morning before seeing an increase
in coverage with a low probability for lightning this afternoon
mainly for areas east of Pittsburgh (ahead of the surface wind
shift). Hi-resolution models suggest coverage may still be
spotty this afternoon (not a continuous shower as TAF line may
suggest) with precipitation likely ending areawide by 00z.

The lower confidence forecast aspect will be area restrictions
tethered to ceiling heights; timing and duration of each
categorical height is likely to fluctuate for much of the TAF
period. The general trend should favor an improvement toward
high MVFR/low VFR through 18z-22z before the moisture-rich
boundary layer plus stagnation fosters lowering towards IFR
after 03z.

Outlook...
High pressure nudging into the region from the west will aide in
gradual cig improvements toward VFR Thursday afternoon. However,
residual moisture plus some influence from the Atlantic tropical
system may aid an isolated shower that briefly stall those
improvements.

High confidence in VFR returns Friday as high pressure broadens
across the Ohio River Valley. Shower and thunderstorm chances
return Saturday evening into Sunday with the passage of a
notable surface cold front and upper trough.

&&

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

&&

$$

SYNOPSIS...88
NEAR TERM...88
SHORT TERM...88/Lupo
LONG TERM...Rackley/88/Lupo
AVIATION...Frazier