154
FXUS61 KPBZ 010613
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
113 AM EST Mon Dec 1 2025

.SYNOPSIS...
Light snow expected along and north of Interstate 80 tonight
with dry weather elsewhere. Wind slackens some overnight into
Monday as dry weather returns for all under building high
pressure. More widespread accumulating snow is expected with
another system Monday night into Tuesday.

&&

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

- Snow showers redevelop north of I-80 this evening with light
  accumulation before dissipating overnight
- Light winds and dry weather on Monday under high pressure
---------------------------------------------------------------

In the wake of the morning cold front passage, wind gusts this
afternoon ramped up to 35-45 mph across the area aided by
mixing into a 30-40 knot low level jet. Expect that gusts will
ease some headed into the overnight hours tonight as the jet
weakens some, but likely still remain elevated as high as 20
mph as the boundary layer remains well mixed. Despite that and
thick cloud coverage, we`ll still see overnight lows drop to
the low to mid 20s across the area. Dry weather returns except
for along I-80 where some snow is likely overnight.

A secondary surface trough will rotate through the Great Lakes
this evening and associated surface convergence drives
reinvigoration of an area of snow along and north of the I-80
corridor where the moisture depth briefly extends back into the
DGZ. HREF mean QPF is around 0.05-0.09 inches, and 90th
percentile not much higher than that, into our northern zones.
So, with SLRs around 17:1, an inch to locally two is plausible
though highest amounts will be off to our north.

Short-lived high pressure will build across the Ohio Valley on
Monday, resulting in light winds and dry and cool conditions
through the day. Some broken sunshine may be seen Monday morning
before clouds fill back in ahead of the next system, which is
forecast to move through the area Monday night into Tuesday.

&&

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

- Rain and snow return late Monday night
- Ice possible in the Mon Valley and WV/PA ridges
- Advisory level snow possible across much of the region
----------------------------------------------------------------

Another shortwave traverses the Great Lakes Monday and moves
eastward into the Ohio Valley by Monday night. At the SFC, this
drags a low northward from the Gulf Coast, through the Southeast and
up the Eastern Seaboard. As such POPs begin to increase across
our region late Monday night from west to east.

Most models and ensemble solutions have come into agreement more
closely on the precise low track through coastal GA/SC and directly
up the East Coast, positioning us on the far northern edge. This
track places the transition zone along and south of I-70 and along
and east of the Ohio river. Areas north and west of this have a
better shot to remain all snow and therefore have a higher chance of
seeing 2-4" snowfall totals. South and east of this, precip types
may be an issue for snowfall accumulation with a wintry mix more
likely in this region. Probabilities for Advisory level snow have
climbed across much of the region (save for the Mon Valley) compared
to 24 hours ago. Probabilities for Warning level snow remain largely
between 10-20% at their highest.

Snowfall rates of 1"/hour seem possible in the heaviest snowfall,
likely during the predawn hours of Tuesday morning. These rates peak
in several stripes running SW to NE across the region, highlighting
embedded heavier bands in the stratiform snow. Neighborhood
probabilities for 1"/hour rates peak as high as 60-80% in SE Ohio
near the I-70 corridor, but are at least 20-30% across much of the
region.

Stout 850mb WAA racing up the spine of the Appalachians points
towards the possibility of freezing rain in the Mon Valley and
eastern ridges early Tuesday morning. These chances remain
highest in our WV ridges, where the best WAA will be. Further
west towards the Ohio river, there could still could be freezing
rain if the WAA over performs but current model soundings point
towards a period of melting snow or sleet. Ice accumulations of
a glaze up to a few hundredths could be possible by Tuesday
morning, highest in the WV ridges.

At this time a Winter Weather Advisory looks likely for much of the
area for accumulating snowfall and then perhaps another in the
ridges for possible ice. We could end up in a situation where the
only areas that do not need a Winter Weather Advisory would be
portions of the Mon Valley, where snowfall totals will be kept in
check by low SLRs/rainfall and freezing rain chances are lower than
just east in the ridges. No matter the headline decision, the
Tuesday morning commute could be a messy and potentially dangerous
one across the region. Please allow for extra time to reach your
destinations and we urge extra caution on area roadways.

The system continues quickly climbing the Eastern Seaboard Tuesday
afternoon. POPs begin to decline during this time period, with the
best forcing and moisture moving northeastward and fleeting across
the region. Snowfall may linger longest near and north of I-80 as
well as in the ridges with a brief push of NW flow. This will be
short-lived however, as winds are expected to back through Tuesday
night shutting this off.

&&

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

- Active pattern continues
- Briefly dry Wednesday before more systems Thursday and Friday
  into the weekend
- Below normal temperatures through the period
-------------------------------------------------------------------

A brief stay by high pressure returns dry conditions to the region
Wednesday but the overall active pattern continues.

During the day Wednesday SFC low pressure deepens over the northern
Great Lakes and traverses eastward through Ontario and Quebec. The
associated cold front dips through the region Wednesday night and
Thursday. The best synoptic support remains well to the north
lending only a real uptick in POPs north of I-70. Model soundings
seemingly support all snow with a possible rain/snow mix along the
far southern edge Thursday afternoon.

High pressure and dry conditions stay briefly again Thursday night
into early Friday before another system is expected to climb from
the Gulf Coast to the Eastern Seaboard. Once again the exact track
of this system will determine exact precip type and snowfall
amounts, but at this time it looks like wintry weather could be with
us to end the work week and begin the weekend.

Temperatures are likely to remain below average throughout the
period favoring daytime highs in the low to mid 30s.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
Gusty winds, now to around 15kt, will continue to diminish
through the early morning hours. Light snow continues early this
morning with a crossing shortwave, primarily north of I-80 (FKL,
lower impact at DUJ). This should taper off through sunrise.
Otherwise, MVFR ceilings remain likely areawide, scattering to
VFR late morning into the early afternoon.

Another low pressure system will impact the region tonight into
Tuesday, bringing a round of widespread snow to the area and
mixed precip for the Mon Valley. Heaviest snowfall is expected
to occur during the 06-12z Tuesday timeframe, and may feature
one or more narrow SW/NW oriented bands within the broader snow
shield. There is a roughly 30-50% probability for rates within
these bands to exceed 1 inch per hour.

Outlook...
Widespread snow should end later Tuesday morning with gradual
ceiling improvement into Wednesday. Additional light snow chance
is expected Thursday, favoring locations north of PIT.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Winter Weather Advisory from midnight tonight to 1 PM EST
     Tuesday for PAZ007>009-013>016-020>022-029-031-073-075-
     077-078.
     Winter Weather Advisory from 4 AM to 4 PM EST Tuesday for
     PAZ074-076.
OH...Winter Weather Advisory from midnight tonight to 1 PM EST
     Tuesday for OHZ039>041-048>050-057>059-068-069.
WV...Winter Weather Advisory from midnight tonight to 1 PM EST
     Tuesday for WVZ001>004-012-021-509.
     Winter Weather Advisory from 4 AM to 4 PM EST Tuesday for
     WVZ510>514.

&&

$$

SYNOPSIS...Rackley/MLB
NEAR TERM...Cermak/Rackley/MLB
SHORT TERM...Rackley/AK
LONG TERM...Rackley/AK
AVIATION...Rackley