295
FXUS61 KPBZ 070539
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
1239 AM EST Sun Dec 7 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 TODAY/...
KEY MESSAGES:

- Light snow showers for I-80 and the ridges, flurries elsewhere
- Freezing drizzle possible for I-80 and the ridges through
  early tonight
---------------------------------------------------------------

Evening update...The current conditions across the area feature
a continued shallow moisture layer between 925MB and 800MB. The
evening sounding supports this analysis but with a inversion
within the area, the shallow layer may soon dry out. Surface
observations have shown flurries and FZFG at times with a few
spots of patchy freezing drizzle. The reports are few and far in
between so decided to keep the HWO mention and keep on the
weather story on the mention of the potential. The threat is
expected to dry out or dissipate by 06Z.

Previous Discussion...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 /TONIGHT 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 SATURDAY/...
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 /06Z SUNDAY THROUGH THURSDAY/...
Prevailing MVFR ceilings are ongoing and expected to continue
throughout much of the TAF period. Some reductions to high-end
IFR will be possible this afternoon, primarily near and north of
PIT where there is also a chance for a few passing light snow
showers. Confidence in any snow (and associated restrictions)
drops the farther south you go. With probabilities of any
precipitation only ~20% at ZZV, HLG, and MGW, no precipitation
was noted at those locations for now. Elsewhere, a mix of
PROB30s (lower confidence) and TEMPOs (higher confidence) have
been maintained to reflect estimated onset and end times.

Shower activity tapers overnight as a weak cold front moves
through and light west winds shift to more northwesterly or
northerly. MVFR ceilings will continue to prevail following the
frontal passage.

Outlook...
The overall weather pattern through the week strongly favors
shortwave movement within upper troughing that brings
precipitation and restriction potential to the area generally
every other day. Precipitation chances remain largely in the
form of snow, save for short periods of rain at southern
terminals during daytime hours.

&&

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

&&

$$

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