624
FXUS61 KPBZ 271146
AFDPBZ

Area Forecast Discussion
National Weather Service Pittsburgh PA
646 AM EST Thu Nov 27 2025

.SYNOPSIS...
Much colder temperatures will continue through Saturday. A
trough of low pressure and lake enhancement will maintain
scattered flurries and snow showers across much of the area
through Friday, with heavier lake effect snow bands for areas
north of Interstate 80. Dry weather returns Saturday before low
pressure brings ran and snow Saturday night and Sunday.

&&

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

- Cold and gusty with scattered snow showers and flurries
- Lake enhanced snow bands developing north of I-80
- Wind Advisory through 11 AM for the ridges
---------------------------------------------------------------

A vertically stacked low was located across the Upper Great
Lakes/central Ontario. A vort max rotating around the low was
maintaining scattered snow showers across the region early this
morning. This should exit early today, with a brief reduction in
snow showers and flurries.

Snow showers and flurries should increase in coverage later
today with the approach of an upper trough, and as steep lapse
rates provide lift through the dendritic growth zone. The
boundary layer flow off of Lake Erie is expected to remain WSW
for much of the day, keeping the more intense lake enhanced snow
bands just to the north of the forecast area. There will still
likely be more numerous snow showers late this afternoon north
of I 80 where some lake enhancement will increase as the
boundary layer flow veer slightly more to the west. Daytime snow
accumulation of an inch or two is possible in this area, when
combined with the gusty wind, could cause reduced visibilities
and travel impacts.

Mixing and a tight pressure gradient between the low to our
north, and high pressure to the west, will maintain gusty wind
through the day, though gusts should begin to diminish later
today as the pressure gradient lessens. Maintained the Wind
Advisory for the ridges through 11 AM. Temperatures are
expected to be 10 to 15 degrees below average.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
KEY MESSAGES:

- Snow showers continue tonight, with lake enhanced bands near
  and north of I-80, where a Winter Weather Advisory continues
- Cold temperatures continue
- Dry Saturday
- Snow returns Saturday night

----------------------------------------------------------------

A shortwave trough, rotating around the upper low, will approach
and cross the region tonight. This should result in scattered
snow showers, especially for areas north of I-70 and in the
ridges where better moisture in the dendritic growth zone is
expected. The crossing shortwave should also result in veering
boundary layer winds to the WNW, which should result in a
southward shift to the lake effect snow bands to near and north
of I-80. Continued the Winter Weather Advisory as is, with a
continued potential that persistent bands could result in higher
snow accumulation, and a possible upgrade to a Lake Effect Snow
Warning. At this time, it still appears the most probable areas
for warning level snow would near and just north of our forecast
area, so will continue the advisory.

The shortwave trough axis shifts east Friday, though lingering
WNW flow off of Lake Erie should maintain snow showers through
the day, with the most impactful snow north of I-80.

Surface high pressure begins to build in Friday night, as the
flow backs to the SW, ending any remaining snow showers.
Dry weather is expected on Saturday as the high moves across the
region.

An upper trough is progged to dig across the Central CONUS later
Saturday, and begin to approach the Upper Ohio Valley region
Saturday night. A deepening surface low is also progged to track
from the Midwest to the Great Lake region by Sunday morning,
pulling a warm front north across the region. Increasing
moisture, and ascent in warm advection, should result in snow
overspreading the region later Saturday night. Some jet
enhancement to this ascent is also possible. At this time
probabilities for an inch or two of snow are highest (40-60
percent) north of Pittsburgh. Will monitor the development of
this system over the next day or two.

&&

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

- Snow and rain for Sunday
- Generally dry Monday before unsettled weather returns by mid
  week
-------------------------------------------------------------------

The shortwave trough is progged to cross the Upper Ohio Valley
region on Sunday, as the surface low pulls a cold front across
the area. Snow should mix with and change to rain in warm
advection ahead of the front, though there is still uncertainty
in how strong the warm advection will be, and how far north this
changeover would occur. The precipitation should end from W-E
Sunday night after FROPA, though some snow could linger north of
PIT as the flow turns NW off of the lakes. High pressure is
expected to build in Monday with dry weather.

A shortwave trough is progged to track east from the Central
CONUS Monday night and Tuesday, as a surface low develops near
the Gulf Coast. This trough is expected to cross the region on
Tuesday, as the surface low tracks along the coast. Rain and
snow chances return Monday night and Tuesday. Operational models
differ on the amount of warm advection ahead of the trough,
while ensembles indicate a colder solution with more snow as a
precip type. Will maintain a mention of rain and snow in the
forecast with the uncertainty at this time. Temperatures will
generally remain below average through the period.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
Strong cold advection underneath upper level troughing will
support fairly persistent low VFR stratocu through the TAF
period with potential for diurnally driven mixing to result in
an isolated light snow shower.

Confidence is fairly high that veering of the 850mb flow to a
slightly more NW direction will not occur until after 21z. As
that component more develops, lake enhanced showers are likely
to grow in coverage to offer periodic bouts of generally light
snow at most regional airports through Friday morning. This
veering may also expand the southern reach of high MVFR cigs
during the overnight period, though fluctuations between MVFR
to VFR cigs could still occur.

For FKL/DUJ (and lesser extent, BVI) in northwest PA, lake
effect bands may develop at any point after 21z that could
rapidly drop visibility below 1 mile and exhibit snowfall rates
around 0.5"/hr but upwards of 1"/hr. Confidence is lower on
whether this band will fall over either terminal AND whether it
will persist for a long duration; additionally, it is possible
the band experiences too much shear and ends being on/off heavy
snow showers versus a consistent band.

Outlook...
Scattered generally light snow showers that could still offer
brief visibility/ceiling drops will slowly taper off through
Friday evening due to height rises and increasing subsidence.
Save for FKL/DUJ (where MVFR cigs may linger into Saturday
morning), VFR is highly likely at the rest of the area terminals
by 18z Friday.

The next low pressure system arrives early Sunday morning,
creating widespread precipitation chances with high confidence
on MVFR to IFR restrictions through the day. Thermal profiles
suggest initial precipitation may fall as snow and have some
potential for accumulation (favoring ZZV/BVI/FKL/DUJ) before
warm advection aides in a changeover to rain.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...Winter Weather Advisory until 7 PM EST Friday for PAZ007>009.
     Wind Advisory until 11 AM EST this morning for PAZ074-076-078.
OH...None.
WV...Wind Advisory until 11 AM EST this morning for WVZ512>514.

&&

$$

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