921
FXUS61 KPBZ 231646
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1246 PM EDT Sat Aug 23 2025

.SYNOPSIS...
Isolated showers and storms are anticipated east of Pittsburgh
today and tomorrow as a cold front approaches and passes through
the region. A prolonged cool pattern is expected to set in
beginning Monday.

&&

.NEAR TERM /THROUGH TONIGHT/...
KEY MESSAGES:

- An approaching front returns scattered showers/storms today
  primarily east and south of Pittsburgh.
- Near average temperatures expected across the region
---------------------------------------------------------------

The 12Z morning PIT sounding indicates low-level moisture below
750mb, with subsidence and warm air in the mid-levels. Cloud
coverage on satellite has increased with prevailing southwest
flow, accompanied by a moisture influx and rising dew points
across several sites. Despite the moisture, warm air aloft and
weak lift has limited convective development right now. However,
with time, an approaching trough from the northwest is expected
to provide sufficient lift to initiate showers and a few
thunderstorms late this evening, mainly after 6pm. Storms will
likely not be considered severe; lightning would be the main
threat east of Pittsburgh. In the worse case scenario, a few
storms may create heavy downpours; a few spots could see an inch
of rain. However, with a mostly dry pattern for the past
several days, the potential for flooding is considered low.

Isolated rain showers and storms may continue east of Pittsburgh
into the overnight time period into early Sunday. With lingering
low-level moisture overnight, patchy fog is possible to develop
overnight.


&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
KEY MESSAGES:

- Shower/storm chances continue Sunday with a passing cold
  front
----------------------------------------------------------------

Temperatures will continue to roam around seasonable values
Sunday as southwesterly flow maintains the advection of warm,
moist air into the region ahead of the approaching mid- level
trough. PWATs are not projected to be exceptionally high (around
1.2 - 1.4"), even looking at the LREF-TLE clusters` 90th
percentile. So although showers and storms are likely along and
ahead of the cold front, any impacts from excessive rainfall
likely will be limited, given faster storm motion and standard
efficiency of rainfall.

Machine-learning projections of severe-weather and analog
guidance continue to show a low likelihood of flash flood or
severe potential Sunday with the crossing low pressure system.

&&

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

- Cooler weather during first half of next week: highs in the
  70s and lows in the 50s
- On Tuesday, rain showers are possible with northwesterly flow
  off the Great Lakes
-------------------------------------------------------------------

High confidence in the weather pattern persists though much of
the coming week, as ridging amplifies in the wrn CONUS and broad
troughing lingers in the ern CONUS.

Primary variances related to the broad pattern are tied to the
eventual amplitude of the CONUS-scale ridge/trough pattern and
potential for a shortwave trough to advance through the nwly
flow aloft into the Great Lakes region near Wed/Wed night.

No matter how amplified the pattern eventually becomes, a cool
airmass will be invading the region by Mon, with temperature
more typical of mid Sept. than late Aug.

The cooler airmass arriving post-cold front is highly likely to
support the development of lake-effect showers Tue/Wed as the
temperature delta between the water and H85 temp will be
sufficient for deeper convective updrafts. Given the projected
reasonable range of wind directions at this timeframe, the reach
of these showers appears limited to areas near and north of
I-80, with lesser coverage south from the interstate.

&&

.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
VFR will prevail as fog lifts/dissipates. Cu/stratus will
linger around 4-6kft. The mid- level cloud deck will thicken
late in the day and showers/storms are possible after 20z
through sunset with then another round on either side of
midnight. Guidance suggests coverage will be scattered with low
probability to impact any given terminal. Highest probability
lies at MGW/LBE in tandem with the strongest
convergence/orographic ascent, so have included a TEMPO there
and PROB30s elsewhere save ZZV. Wind will increase to 7-10
knots out of the southwest as the gradient tightens with the
approaching front.

.OUTLOOK...
Higher chances of showers/storms arrive with a Sunday cold front
along with increased chances for ceiling restrictions. Subsequent
upper-level troughing and cool air aloft could result in patchy cig
restrictions north of PIT Monday and Tuesday along with a few
scattered showers.

&&

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

&&

$$

SYNOPSIS...Hefferan
NEAR TERM...Hefferan
SHORT TERM...Kramar/88
LONG TERM...Kramar/88
AVIATION...34