988
FXUS61 KPBZ 242350
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
750 PM EDT Sun Aug 24 2025

.SYNOPSIS...
Isolated showers and storms are possible primarily east
of Pittsburgh as a cold front passes through the region. A prolonged
cool and drier pattern is expected to set in beginning Monday with
below normal temperatures through the entirety of the work week.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
KEY MESSAGES:

- Scattered showers/storms associated with a cold front
- Last day of 80s through at least mid-week
---------------------------------------------------------------

Surface low pressure will drag a cold front through the area locally
that will be responsible for development of afternoon showers and
thunderstorms. The best coverage still looks to be along and east of
the Appalachians in proximity to the front. From Pittsburgh and
west, minimal precip is expected at all in the post-frontal
environment.

An area of high DCAPE (1000-1200 J/kg) extends from Kentucky
northeastward to southwestern Pennsylvania; resulting in wind being
the main threat if thunderstorms develop. Progged MLCAPE is not
great around 400-700 J/kg with ensemble mean deep layer shear around
25 knots. This evening, a belt of enhanced mid-level flow sinks
south increasing the deep layer shear as the ML CAPE decreases.
All told, coverage again will be scattered and pose a limited
severe weather risk.

Overnight, conditions will dry out. Wind is expected to ease as it
becomes northwesterly. Small chance for fog north of I-80 and along
the WV ridges.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
KEY MESSAGES:

- Seasonably cool temperatures under upper troughing
- Rain showers possible Mon and Tue in NW flow, mainly north of
  Pittsburgh.
----------------------------------------------------------------

Broad trough, with low centered over Hudson Bay, will be the
main influence on the weather pattern through most of the week.
Pulses dropping through the trough in west-northwesterly flow
will support the generation of showers and possibly a
thunderstorm given the differential between the temps at 850hpa
and the Great Lake water temps. Latest HREF has a an 80-90%
probability of > 0.01" north of Pittsburgh on Monday. However,
when looking at the probability of higher accumulation (i,e
0.10") those values are quite a bit lower (20-40%_ and focused
mainly north of I-80. All of this to say that while there is a
non zero chance that there could be a shower from Pittsburgh
north, the odds are slightly better north of I-80. Model
sounding profiles would support this as well, with more
subsidence noted with the building surface ridge south of Pit.

A stronger shortwave will pivot through the trough later on
Tuesday but again, with limited moisture, PoPs were kept in the
chance category. This time, however, model ensembles
incorporate some upslope into the terrain so precipitation
chances include more of the region south and east of Pittsburgh.
Shortwave and surface ridging should keep conditions dry on
Wednesday.

Cold advection through the period will keep temperatures about
5-10 degrees below average. Low temperatures on Tuesday
night/Wednesday morning will likely dip below 50 degrees (>60%
chance for everywhere outside of the Pittsburgh urban center and
areas along the rivers).

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
KEY MESSAGES:

- Some moderation to temperatures as we round out the week
- Mostly dry conditions anticipated
-------------------------------------------------------------------

General story is that eastern CONUS trough will remain the
predominant feature through the remainder of the period.
However, there are some variances in the model guidance with its
strength and eventual shift toward the east into the weekend
that could influence how quickly temperatures moderate. In other
words, if the trough moves out faster, temperatures will warm
quicker, and if the trough lingers and deepens, temperatures
will stay below average with precip chances continuing. For now,
the consensus is for temperatures to remain slightly below
average with low chances for precipitation into the weekend.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
Cig and vis restrictions are likely with any storm that impacts
a terminal. Added in PROB30 groups at LBE/MGW after 00z as these
terminals are still ahead of the cold front.

Tonight, wind will gradually ease as it becomes northwesterly.
Precipitation will move east of the region by midnight. Clouds
are scattering out behind the front. Tomorrow morning, there is
a small probability (up to 20%) for some fog to bring IFR
visibility to DUJ/FKL.

During the day on Monday, expect gusty conditions out of the west up
to 15-20 knots. VFR conditions expected to prevail throughout the
day. Due to west-northwesterly flow, lake effect showers may
develop off Lake Erie, impacting DUJ/FKL. These showers could
bring temporary MVFR conditions.

.OUTLOOK...
Cool air aloft could result in patchy MVFR cig restrictions north of
PIT from Tuesday-Thursday morning. Isolated lake enhanced showers
possible north of PIT Tuesday and Wednesday.

&&

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

&&

$$

SYNOPSIS...Cermak/Lupo
NEAR TERM...MLB/Lupo
SHORT TERM...34
LONG TERM...34
AVIATION...Lupo