536
FXUS61 KPBZ 081133
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
633 AM EST Mon Dec 8 2025

.SYNOPSIS...
Very cold start to a largely dry Monday with snow south of the
Mason-Dixon line. Continued rounds of rain and snow chances
prevail through next week. The strongest disturbance looks to
sweep the area Wednesday as a mix of rain and snow. Temperatures
trend downwards late this week into the weekend.

&&

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

- Cold and largely dry for most Monday
- Snow and flurries south of the Mason-Dixon line
---------------------------------------------------------------

Strong dry advection is quickly eating away the cloud deck
across the region and clearing has reached the Pittsburgh. Clear
skies and light winds overnight yield efficient radiational
cooling and low temperatures north of I-80 can end up near 10
degrees, with single digits possible if winds can go calm.
Increased high level clouds and less subdued wind keeps the Ohio
and Mon Valleys closer to 20 degrees.

Much of the area feels the influence of cold Canadian high
pressure sliding across the Great Lakes promoting a cold and dry
day. Despite this, a weak inverted trough tied to a
southeastern low crosses the mid-Appalachians and brings chances
for snowfall across our WV ridges. Morgantown and Fairmont may
see flurries from this but accumulating snowfall is not
expected. Accumulations are more confined to Tucker County,
where some places may see up to an inch of snowfall through the
day.

High temperatures areawide fall 10-20 degrees below average.
Skies clear dramatically overnight as the center of high
pressure slides just north of the region promoting lighter winds
overnight. This yields another good chance for strong radiative
cooling and single digit lows look possible north of 422 with
much of the region outside of the Ohio and Mon valleys falling
into the low teens. Clouds begin to build back in as we approach
sunrise so there will be a time limit on the most efficient
cooling.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
KEY MESSAGES:

- Another light snow north of Pittsburgh Tuesday
- Stronger system brings rain/snow mix Wednesday with an
accumulating heavy wet snow north of I-80 and in the ridges
- Winds increase Tuesday and again Wednesday
----------------------------------------------------------------

A very subtle shortwave builds through the flow and crosses the
Great Lakes during the day Tuesday. At the SFC, a weak low is
progged to dive across the northern Great Lakes with us on the
far southern periphery. As such, POPs increase slightly north of
422 but noticeable increases are contained north of I-80 where
snowfall is most likely. The quick passage of this system could
bring around an inch of snowfall north of I-80, but
accumulations elsewhere seem unlikely and there may just be
flurries reaching south of 422.

As this weak low crosses the region, our SFC pressure field
begins to tighten and wind gusts slowly increase through the
afternoon reaching between 20-30mph for many.

The Tuesday system departs as quickly as it came and POPs fall
quickly by sunset as snow is confined to nearer the lakes. A
brief stay of dry weather follows before POPs rise again
overnight as a more potent shortwave rounds the base of the
trough pushing a low through the central and southern Great
Lakes. Modeling has waffled greatly on the exact track of this
low. The EURO and its ensembles have kept the track largely
consistent in the last 24 hours from Georgian Bay to Ottawa
keeping our region firmly in a rain/snow mix accordingly with
less snowfall. The GFS against its ensemble has trended the
track 50-100 miles south over the last 24 hours and accordingly
brings far more snow across the region. This forecast cycle we
have kept things more consistent with an eye on a possible
southern track bringing more snowfall.

As it stands now snowfall looks most likely along I-80 and down
the ridges with the lowlands experiencing a rain/snow mix at
onset transitioning to rain during the daytime hours.
Temperature profiles support a heavy wet snowfall with some
melting possible at the surface. Probabilities of advisory level
snow are currently largely between 20-40% across Venango,
Jefferson, Clarion, Forest and eastern Tucker Counties.
Probabilities for at least an inch of snowfall are as high as
90% in the aforementioned counties and along the PA ridges but
fall quickly south of 422 and outside of the terrain. For
Pittsburgh, flakes can be seen at onset but Wednesday likely
features a cold rain with high temperatures near 40 degrees.

Our SFC pressure gradient tightens even more Wednesday and many
areas can see gusts 25-35 mph with gusts to 45 mph possible in
the ridges. At this time a wind advisory would be most likely
for eastern Tucker, with the probabilities of advisory level max
gusts peaking largely between 20-30% elsewhere.

The shortwave quickly departs east by Wednesday afternoon and
flow turns northwesterly promoting upslope and lake enhanced
snow but lowering POPs across the lowlands.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
KEY MESSAGES:

- Below normal temperatures continue through the long term
- Additional rounds of potential winter weather with a series of
  passing disturbances mid to late week and into the weekend
-------------------------------------------------------------------

Timing issues likely continue to trouble NBM POP outputs on
Thursday as the lowlands are expected to be largely dry with
lingering snow contained to the ridges and lakes in NW flow.

Yet another shortwave crosses the region Thursday night into
Friday and there are indications for some weak system tied to it
bringing another chance for light snowfall.

By Friday night ensembles are in large agreement that the base
of the longwave trough begins to approach the region, bringing
another system with it. Ensemble low centers largely favor a
Canadian track with this system bringing yet another push of
sub-advisory level snow to the region.

Temperatures in the extended period look to fluctuate some
early but with the trough advancing into the region, trend down
as we head towards the weekend. Differing depictions of the
depth of the trough as it moves overhead lead to a wide spread
in temperatures for next weekend. Ensembles that favor a deeper
trough feature another shot of very cold air, some with low
temperatures heading back towards the single digits.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
KEY MESSAGES:

- VFR with cirrus favors through the majority of the TAF
  period.
- Active weather pattern will continue through end of week that
  creates periodic precipitation and restriction chances.
-------------------------------------------------------------------

Surface high pressure settling over the Great Lakes will promote
VFR conditions through the TAF period, with occasional breezy NE
winds through the early afternoon. Upslope convergence overnight in
the wake of upper shortwave movement south of the region will likely
result in scattered to broken below 5kft cigs along the WV
higher terrain, nearing MGW. Hi-res guidance suggests a 40-60%
probability of this stratus layer coming in below 3kft after 06z
at MGW; will hold off TAF mention for now but monitor this
solution`s trend.

Outlook...
The overall weather pattern remains active through the end of
the week as a series of disturbances traverse the region,
bringing precip and restriction potential to the area almost
every day. Precipitation chances remain largely in the form of
snow, save for short periods of rain at southern terminals
during daytime hours. Winds look to increase Tuesday and
especially Wednesday as one of the more potent disturbances this
week moves through the area.

&&

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

&&

$$

SYNOPSIS...AK
NEAR TERM...AK
SHORT TERM...AK
LONG TERM...AK
AVIATION...Cermak/Frazier