263
FXUS61 KPBZ 200653
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
253 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 AM THIS MORNING/...
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 into western PA early 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 and eastern OH this morning.

Lows will bottom out well above normal with cloud coverage and
continued low level mixing/turbulence.

&&

.SHORT TERM /6 AM THIS MORNING 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 expected into the weekend
- Precipitation chances return Saturday into Sunday with a
  passing cold front
- Cooler weather begins next week.
-------------------------------------------------------------------

Extended forecasts indicate that a ridge of high pressure over
the Ohio River Valley will be present into Friday, bringing
mostly dry conditions and temperatures that are near to above
average.

A passing cold front and an upper-level trough will likely
increase the chances of precipitation Saturday into Sunday, but
rainfall amounts look low this far out. NBM PQPF for >0.25"
range from just 30%-40% for counties along the Appalachian
ridge-line and less than 25% chance west of Pittsburgh. Of note,
machine learning does indicate a 5% to 15% chance of severe
weather with this passing front on Sunday, so this will need to
be monitored in the coming days.

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 /07Z WEDNESDAY THROUGH SUNDAY/...
Broken line of showers and the occasional rumble of thunder
continues to cross the area early this morning in advance of a
cold front. Given less favorable environment, and little
lightning remaining, have removed mention of thunder for the
remainder of the overnight period. A period of low MVFR to IFR
ceilings is expected following frontal passage, impacting most
terminals by 14z. Cigs should then lift through the day with
mixing, though a few afternoon showers/tstms are possible with a
secondary shortwave as it drops SEWD across the region. This
secondary rain chance should dissipate through the evening
hours.

Low-level moisture tonight will allow stratus and fog through
Thursday morning.

Outlook...
VFR is then expected to return Thursday afternoon under high
pressure until the approach of a Sunday cold front.

&&

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

&&

$$

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