364
FXUS61 KPBZ 240521
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1221 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:

- Milder Monday with increasing clouds
- Rain returns by Tuesday morning, with wetting rain areawide during
  the day
----------------------------------------------------------------

A crossing mid-level ridge axis will continue to provide dry weather
Monday. The sky will be mostly clear early, but return flow behind
departing high pressure should push mid and upper clouds into the
region through the afternoon. Temperatures will remain fairly
seasonable, adding 2 or 3 degrees to today`s highs in spots.

The next mid-level shortwave, over the central Plains Monday
morning, is forecast to ride northeast into the Middle Ohio Valley
by Tuesday afternoon, dampening as it does so. A surface low
reflection forms in the lee of the Rockies tomorrow and should track
into the Upper Midwest by 00Z Wednesday. An approaching warm front
and right entrance region jet dynamics provide the support for lift.
Combined with an moistening air mass with precipitable water
values climbing towards one inch, this will provide increasing
rain chances after 06Z Tuesday, with widespread rain coverage
developing after sunrise. Most locations are expected to receive
a wetting rainfall, with eastern Ohio having the best chance of
exceeding a half-inch (40 to 50 percent chance). Temperatures
will rise to between 5 and 10 degrees above normal both Monday
night and Tuesday in this pattern.

&&

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

- Diminishing rain chances into Wednesday
- Gusty shower potential Wednesday afternoon
- Colder conditions Thanksgiving and into the weekend
- Lake-effect snow potential late Thursday into Friday
-------------------------------------------------------------------

Increasing mid-level dry air entrainment should lessen rain coverage
and intensity Tuesday night into Wednesday.  Areas east of
Pittsburgh have better chances of adding an additional tenth of an
inch or so of rain as compared to locations like eastern Ohio.
Temperatures remain mild, with some locations likely not getting
below 50 degrees Tuesday night.

A surface cold front should pass across the Upper Ohio Valley
Wednesday afternoon or evening, while the surface low is in the
vicinity of the Upper Peninsula of Michigan. Timing remains a bit
uncertain, depending partially on the progression of the larger
500mb trough across the Great Lakes. A line of gusty showers may
accompany the front as steepening low-level lapse rates provide both
some modest instability and a path for a 30-40 knots low-level
jet to mix down.

Although frontal timing is questionable, there is high confidence in
temperatures crashing to well below-normal behind it,
particularly for Thanksgiving and Friday. With lingering
blustery conditions, wind chill values in the teens may
accompany actual temperatures in the 20s Thursday night.

Any remaining showers are forecast to change to snow by Thanksgiving
morning, with lake-effect activity likely developing and continuing
into at least Friday. At this distance, low-level wind still appears
to have more of a westerly direction than northwest, which would
suggest lower potential for impactful snow across most of the
forecast areas.  However, long-range probabilities do continue to
highlight portions of Mercer, Venango, and Forest Counties as
having a bit better potential for more persistent banded
activity, and it is here where some sort of winter headline may
eventually be needed.

Most guidance pushes the trough east of the region by Friday
evening, leading to a decrease of lake-effect activity. Details
become murkier next weekend, but rising heights and a renewed push
of moisture may lead to more widespread precipitation and moderating
temperature by Sunday.

&&

.AVIATION /06Z 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...CL
LONG TERM...CL
AVIATION...WM