289
FXUS61 KPBZ 082302
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
602 PM EST Mon Dec 8 2025

.SYNOPSIS...
Active weather pattern through next weekend will bring rounds of
snow, occasionally mixed with rain, as well as fluctuating
temperature and gusty winds. Overall, the seasonably cool
conditions are favored with snowfall accumulations favoring
northwestern Pennsylvania and the higher terrain of West
Virginia.

&&

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

- Snow tapering off for far southern zones
- Seasonably cool temperature continues
---------------------------------------------------------------

Surface high pressure centered over the Great Lakes will
continue to promote dry weather and generally clear conditions
across the region; cold, dry air working in from the NE ensures
temperature remains well below the seasonal average. Weak
shortwave/surface low pressure movement south of the region may
maintain generally light snow over the far southern portions of
the forecast area through this evening before its eastward exit
signals an end.

Overnight low temperature should be on the order of 10 to 15
degrees below the daily average; however, subtle nuances like
wind staying slightly more elevated/mix out of the E or
lingering cirrus (or surging lower stratus from south in warm
advection) may stunt the degree of cooling currently forecasted.

&&

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

- Weak, fast moving trough brings light snow to northwest PA
  Tuesday afternoon
- Stronger low Wednesday features a mix of rain and snow that
  will transition back to all snow Wednesday night
----------------------------------------------------------------

A weak shortwave currently crossing the northern Great Plains
is expected to drop through the eastern Great Lakes by Tuesday
evening. As high pressure slides to the Atlantic Coast in
response to its approach, weak warm advection will lift area
temperature approximately 10 degrees above today`s readings.
Meager moisture profiles and weak jet-ascent will limit this
system`s precipitation shield to along/north of I-80; timing of
the passing wave and weak frontal boundary favors a 2pm onset
and 7pm exit with any lingering precipitation being light and
generally non-accumulating. Thermal profiles favor all snow but
that lack of deeper moisture/strong lift means probabilities of
exceeding 1" of accumulation is low (15-30%).

Rapid transition occurs Tuesday night into Wednesday morning as
a deeper upper trough wave enters the Great Lakes region in the
wake of the prior wave. The Tuesday afternoon front is likely to
quickly stall then lift northward as a warm front as southwest
flow develops ahead of the approaching low. Strengthening
jet-aided ascent along with the warm front will aid
precipitation development into northwest PA and eastern OH during
the early morning hours before spreading areawide by the
afternoon ahead of the upper trough/surface cold front passage.

Precipitation type will be a bit more tricky given the
aforementioned warm advection ahead of the axis, but overall
confidence remains relatively high. Any snowflakes that fall
across eastern OH into southwest PA are likely to change over to
rain within a few hours of onset, preventing accumulations.
Change over, or the occurrence of a rain/snow mix, will be later
in the afternoon for northwest PA and the higher terrain
southeast of Pittsburgh. Until this occurs, accumulating wet
snow is likely and favoring the I-80 corridor during the morning
commute (6-hour totals of 1-2" with locally higher amounts
expected in this period). If confidence increases for potential
roadway impacts or higher accumulations, a Winter Weather
Advisory may be needed covering this period (see more on snow
below). Beyond the precipitation, tight surface gradients will
foster gusty post-frontal wind between 25-35mph in the
afternoon in the lower elevations (nearing Wind Advisory
criteria in eastern Tucker).

Rapid movement of the surface low and upper trough shortwave
towards the New England region will occur Wednesday night into
early Thursday morning. Residual northwest flow, weak vorticity
advection, and strong cold air advection means a change over to
snow showers that receive lake enhancements occurs through the
late afternoon to evening hours Wednesday. For most locations,
that will generally be light on and off snow showers resulting
in less than 1" of total accumulation. Higher confidence exists
for potential headline-worthy accumulations and/or impacts along
the I-80 corridor and higher terrain, but location/duration
of the heaviest snow varies due to subtle differences in
ensemble model synoptic patterns. For eastern Tucker County,
wind may remain elevated such that falling, blowing snow could
create periods of significantly reduced visibilities that
further complicates travel. If confidence in totals or impacts
increases, especially as higher- resolution model data comes
into play, headlines may be needed for those areas (I-80
corridor and higher terrain southeast of Pittsburgh).

&&

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

- Unsettled pattern continues through the weekend
- Lake effect & terrain driven snow Thursday/Friday with another
  system over the weekend
- Temperatures remain well below average
-------------------------------------------------------------------

The unsettled pattern continues to close out the week and into next
weekend as mid-level troughing continues to plague the ECONUS.
Indications among ensembles are for a deeper, closed low to
eventually take shape across Ontario and Quebec allowing for cold
air to filter in, albeit with both timing and depth differences.
Confidence is increasing in a several day period where we have high
temperatures some 15-20 degrees below average in the cP airmass
through next weekend and likely the coldest air of the year so far.

Regarding precipitation, those aforementioned timing issues have,
and still are, troubling the NBM PoPs for a good portion of Thursday
and Friday; it continues to advertise chc to even lkly PoPs when, in
reality, a good chunk of that timeframe will likely be dry,
especially in the lowlands with lingering snow contained to the
ridges and lakes in NW flow. What seems more likely at this time is
that we`re between shortwaves late Thursday into Friday, and we`ve
lost enough moisture and forcing in the post-frontal environment to
confine snow to the ridges and I-80 corridor. Some ensemble members
bring in transient high pressure during this timeframe lending
higher confidence to more broad dry conditions. After that, yet
another shortwave crosses the region late Friday and Saturday with
the synoptic pattern favorable for a fast moving clipper system and
another chance for some snowfall accumulation dependent on track and
available moisture. Ensemble low centers largely favor a Canadian
track with this system, though some bleed down a bit farther south,
so will monitor these trends and resultant impacts locally through
the week.

Longer range ensemble members signal that there could be some
breakdown to the troughing pattern by early next week and a trend
back toward normal temperatures, but that remains highly
uncertain with many solutions still in play. NBM MaxT suggests
10-15 degree MaxT spread come early next week ranging from the
teens on the low end to the mid 30s on the high end.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
KEY MESSAGES:

- VFR for most of the TAF period
- Restrictions in snow at FKL and DUJ Tuesday afternoon
- Increasing S-SW wind Tuesday
-------------------------------------------------------------------

High pressure will maintain VFR for most airports through
Tuesday morning. The exception will be for sites mainly south
and east of PIT, where a period of MVFR stratocu cigs are
expected late tonight into Tuesday morning as cloud cover moves
north with a backing wind.

Increasing mid level cigs are expected Tuesday as a warm front
approaches. The best lift and moisture for snow is progged
across areas north of I-80, where FKL and DUJ will likely see a
period of MVFR vsbys in light snow. An increasing pressure
gradient in the vicinity of the front should also result in
increase S-SW wind, with gusts around 20 kt by late morning
through the afternoon.

Outlook...
Restrictions and gusty wind are expected in rain and snow
Wednesday with crossing low pressure. Restrictions and
scattered snow showers are expected Thursday and Friday with a
crossing upper trough, and again Saturday with approaching low
pressure.

&&

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

&&

$$

SYNOPSIS...Frazier
NEAR TERM...Frazier
SHORT TERM...Frazier
LONG TERM...MLB
AVIATION...WM