561
FXUS61 KPBZ 240840
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
340 AM EST Mon Nov 24 2025

.SYNOPSIS...
Dry and quiet weather today. Rain chances return tomorrow
morning and continue into Wednesday. Cold temperatures and
lake-effect snow chances increase Thanksgiving Day and Friday.

&&

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

- Patchy river valley fog this morning
- Dry and quiet today
---------------------------------------------------------------

With clear, calm overnight conditions, patchy river valley fog
may develop near daybreak. Otherwise, the day will remain quiet
and dry under high pressure. Upper-and mid-level clouds will
gradually spread from the south ahead of an approaching
disturbance.

Afternoon high temperatures will trend a few degrees above
average.

&&

.SHORT TERM /TONIGHT THROUGH 6 PM TUESDAY/...
KEY MESSAGES:

- Rain returns by Tuesday
----------------------------------------------------------------

A closed upper-level low over the Rocky Mountains is expected to
transition into an open-wave trough over the next 24 hours and
move east, bringing in warm, moist air just before daybreak
Tuesday. The probability of measurable rain increases in
eastern Ohio over 80% between 6am and 9am and in western
Pennsylvania between 7am and 10am. Steady rain is likely through
early afternoon, supported by a deep moisture profile with
Precipitable Water (PWAT) values near 1.00 inches. As a dry slot
approaches from the west, rain coverage should become more
scattered from early afternoon into the late evening. By sunset,
rainfall totals are expected to range from 0.30 to 0.60 inches,
with localized higher amounts south of Pittsburgh. However,
there is only a 10 percent chance of amounts exceeding an inch.

&&

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

- Gusty shower potential Wednesday afternoon
- Colder conditions Thanksgiving and into the weekend
- Lake-effect snow potential late Thursday into Friday
- Milder conditions Sunday

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

Isolated showers will persist Tuesday night into early
Wednesday, accompanied by mild conditions as southwest flow
strengthens ahead of a trough moving into the Midwest. With dew
points in the low to mid-50s, overnight and early morning
temperatures are expected to run above 20 degrees above
average.

By early Wednesday afternoon, the trough will deepen over the
Great Lakes and evolve into a closed upper-level low. Despite
this, continued warm advection ahead of a cold front under
strong southwest flow will allow shallow instability to develop
during peak heating Wednesday. Surface instability values may
reach 50 to 150J/kg between 1pm to 5pm. As the cold front
approaches and shower coverage increases, some gusty conditions
may accompany isolated heavier showers. Depending on the depth
of the instability, brief bursts of 40-50 mph wind gusts within
showers cannot be ruled out. Between 6pm and 8pm, the cold front
will likely have shifted east of the region.

In the wake of the cold front, chilly conditions are expected
early Thanksgiving morning, with temperatures hovering near
freezing and wind gusts pushing wind chills into the teens. Cold
advection over the relatively warm waters of Lake Erie will also
support the return of lake-effect snow chances before dawn
Thursday. With an initially westerly flow, snow showers will
mainly be focused north of our county warning area. As
boundary-layer winds turn northwesterly Thursday afternoon and
evening, lake-effect snow showers will likely become more
persistent across Venango, Mercer, and Forest Counties. Winter
weather headlines may be needed north of Pittsburgh Thursday
into Friday for the potential of heavy snowfall amounts within
lake-effect bands.

Strengthening high pressure moving in from the west will likely
reduce lake-effect snow chances Saturday morning.

Long-range ensemble guidance also suggests a return to milder
conditions on Sunday as the broad upper-level trough over the
Northeast shifts offshore and deep southwest flow develops with
a new trough forming near California.



&&

.AVIATION /07Z MONDAY THROUGH FRIDAY/...
Patchy IFR river valley fog is expected to affect ZZV and MGW
early this morning. This should mix out and dissipate after
sunrise. Otherwise, VFR is expected today as high pressure
builds across the Upper Ohio Valley region. Light west wind will
back to the SSE by mid morning, with increasing high level
clouds in warm advection ahead of a shortwave trough approaching
from the central CONUS.

Outlook...
IFR to low MVFR restrictions and rain are expected Tuesday as a
warm front lifts north across the region. Rain and MVFR
restrictions are likely late Tuesday night into Wednesday with a
crossing cold front. Patchy cig restrictions and scattered snow
showers are expected Thursday into Friday with subsequent upper
troughing and cold W-NW flow. Vsby restrictions in snow are
also possible at FKL and DUJ.

Gusty W winds are also likely after FROPA later Wed through
Fri.

&&

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

&&

$$

SYNOPSIS...Hefferan
NEAR TERM...Hefferan
SHORT TERM...Hefferan
LONG TERM...Hefferan
AVIATION...WM