100
FXUS61 KPBZ 061746
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1246 PM EST Sat Dec 6 2025

.SYNOPSIS...
Light snow with patchy freezing drizzle possible this afternoon in
the ridges and along Interstate 80. Light snow accumulation expected
on Sunday again primarily north and east of Pittsburgh. Continued
rounds of rain and snow chances will prevail into next week.

&&

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

- Light snow showers for I-80 and the ridges, flurries elsewhere
- Freezing drizzle possible for I-80 and the ridges this afternoon
---------------------------------------------------------------

Surface high pressure sliding by well off to our south will extend
ridging locally into the southern portion of our area. To the north,
weak low pressure will drag a surface trough across Lake Erie while
a weak mid-level shortwave crosses the Ohio Valley. For most, the
weak forcing combined with limited moisture may squeeze out some
flurries through the day, but no accumulation is expected, and the
day should be mostly dry and cloudy.

The exception will be the I-80 corridor and the PA ridges. For I-80,
closer proximity to the trough and with a bit more depth to the
moisture will allow for light snow showers through the afternoon.
Snow growth won`t be very efficient with a mostly dry DGZ and
shallowing moisture with time, so accumulation will be quite
limited. HREF probability for measurable snow is as high as 30% but
near zero for >0.5". With said shallowing moisture and lingering
weak lift, we`ll transition to an environment supportive of
supercooled liquid water between 0C to -10C below where ice is
present as nuclei for supercooled drops. This may allow for a period
of a freezing drizzle threat this afternoon most likely after 2pm or
so when soundings begin to cut off the mid-level moisture.

For the ridges, weak upslope flow out of the WSW, and gradually
backing further, should provide enough lift to also produce some
light snow showers there today. Seeing similar trends for
accumulation, though HREF prob for measurable is higher at up to 70%
and >0.5" at ~30%. Also similarly, as the depth of the moisture cuts
off, we`ll cut below the favorable snow growth zone and raise the
threat for patchy freezing drizzle.

Have gone ahead with a mention of freezing drizzle/snow in the
forecast but no headlines at this time. Will continue to monitor
through the afternoon for necessity of SPS or short-fused advisory.

&&

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

- Another disturbance brings minor snowfall accumulations to
  areas north of Pittsburgh and in the ridges; a rain/snow mix
  with little accumulations expected elsewhere
- Dry weather and below seasonal temperatures prevail Sunday
  night through Monday night under building high pressure
----------------------------------------------------------------

Another passing shortwave brings higher chances for a wintry
mix to the entire area on Sunday. Precipitation is expected to
start as snow (possibly a rain/snow mix in the Mon Valley)
Sunday morning before transitioning to a rain/snow mix across
the lowlands south of I-80 by late morning and afternoon.
Overall accumulations with the Sunday system are still
anticipated to be light, with measurable snowfall appearing most
likely north of I-80 and in the ridges. NBM snowfall
probabilities are rather pessimistic, suggesting a 40-60 percent
chance for a tenth of an inch north of Pittsburgh and in the
ridges, but a 20 percent chance or less for an inch. Meanwhile,
the event is just now beginning to fall within range of the
HREF, which is suggesting higher probabilities (anywhere from 40
to 80 percent) for an inch of accumulation north of Pittsburgh
(and especially along and north of I-80), but significantly
lower probabilities of around 10-20% for 2 inches in the same
areas. Probabilities are also generally lower in the ridges, for
example a 30 to 50 percent chance for an inch of accumulation
in the Laurels. However, the latest HREF only runs through 7pm
Sunday, so it`s possible these probabilities increase in future
runs as snow showers are forecast to linger in the ridges
through evening.

A cold front late Sunday brings a reinforcing shot of cold air,
leading to low temperatures dropping back into the teens north
of Pittsburgh and low 20s elsewhere Sunday night. Dry weather
and below-seasonal temperatures then continue Monday and Monday
night under the influence of building high pressure.

&&

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

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

A broad trough will transition across CONUS through the period
with the initial cold front progged to cross the region on
Wednesday. Rain is likely with this system and have increased
QPF amounts based on latest model consensus and
anomalies/M-Climate. In general, most locations look to see
around one half inch on average. With cold high pressure
sliding in behind the front, only minor disturbances are progged
the remainder of the period with temperatures dropping back to
near normal.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Erosion of the morning stratus deck combined with increased
mixing/lift provided a brief period of VFR conditions into early
afternoon, save FKL/DUJ who held mostly high-end MVFR. Those
VFR conditions will be short-lived as the afternoon passage of a
mid-level shortwave and surface trough re-introduces an MVFR
stratocu deck and lower probability light snow showers. These
snow showers should mostly be confined to FKL/DUJ with periodic
restrictions to MVFR possible, so have introduced a TEMPO group
for -SN there and omitted mention elsewhere. As the depth of the
moisture cuts off headed into this afternoon, some patchy
freezing drizzle may be observed, though confidence in this is
on the lower side spatially and temporally, so did not mention
this in the current TAFs. Wind will hold around 5-10 knots with
periodic gusts to 20 knots possible this afternoon.

MVFR decks hold strong overnight and through the entirety of
the TAF period. A larger shield of light snow and rain will
overspread the area from the west Sunday afternoon as another
shortwave/weak surface low pass through. This should bring a
higher probability for vis restrictions in snow to FKL/DUJ. A
rain and snow mix is favored for southern terminals, but have
only included mention in the PIT TAF at this time as it falls
just outside the current window for all other sites.

Outlook...
The overall weather pattern through late next week strongly
favors shortwave movement within upper troughing that occurs
almost every other day. Each system will feature varying degrees
of precipitation chances (type mainly snow, save for short
periods of rain at southern terminals), intensities, and either
the continuation of or reintroduction to MVFR-IFR restrictions.

&&

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

&&

$$

SYNOPSIS...MLB
NEAR TERM...MLB
SHORT TERM...Cermak/88
LONG TERM...88
AVIATION...MLB