495
FXUS61 KBUF 081850
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
150 PM EST Mon Dec 8 2025

.SYNOPSIS...
Surface high pressure will keep cold but generally quiet weather in
place through tonight. Temperatures will quickly drop into the
single digits again tonight, with inland sub-zero readings. A few
lake enhanced snows could clip the eastern shoreline of Lake Ontario
overnight. A series of storm systems followed by lake and upslope
effects will then lead to a prolonged period of accumulating
snow for parts of the region. Tuesday and Wednesday`s systems
will bring snow along with gusty winds, with Wednesday`s snow
mixing with a little rain.

&&

.NEAR TERM /THROUGH TUESDAY/...
Surface high pressure over the eastern Great Lakes will ensure
generally dry and quiet albeit frigid weather remains in place
through tonight. Despite the sunshine this afternoon, temperatures
remain some 15 to 20 degrees below normal.

The surface ridge axis will slide south and east of the Great Lakes
and past the spine of the Appalachians tonight. Low level flow
should begin to turn southerly and the overhead airmass modify a few
degrees as a result. Despite this, it will still be cold enough with
winds remaining light enough such that with the snowpack across the
region, temps should easily slide back into the single digits
tonight, with many spots across the interior falling below zero.
Otherwise, a thin plume of low level moisture over Lake
Huron/Georgian Bay this afternoon will advect over Lake Ontario
tonight. Combined with diurnal land-breeze convergence and some
enhancement from the lake, this should cause a band of snow to form
over the eastern end of the lake. Models generally depict this band
having minimal inland extent, though areas closer to the lakeshores
from roughly Oswego to Watertown may pick up a dusting to perhaps a
localized inch or so.

Our stretch of quieter weather will be cut short Tuesday as a
weakening clipper system tracks through the Upper Great Lakes,
becoming further disorganized and diffuse as it moves east. The mid-
level shortwave driving this system will make its way through the
forecast area Tuesday afternoon into early Tuesday evening, with a
warm frontal segment moving through from west to east. This will
cause light snow to once again overspread much of the region, with
lake enhancement developing northeast of the lakes (mainly Lake
Erie) late in the day. A stiff southerly flow and subsequent
downslope drying/upslope enhancement will should yield minimal
accumulations by the evening (generally 0.5" or less) in the Genesee
Valley and Finger Lakes, as well as on the leeward side of the Tug.
The higher amounts are expected across the Niagara Frontier
including the Buffalo Metro and east of Lake Ontario across the
southern slopes of the Tug Hill Plateau itself. Snowfall in
these areas should still be minor with 1-3" by the late
afternoon, though more will be on the way as lake effect bridges
the short gap until the next synoptic system arrives...More on
that in the short term below.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
A complex forecast scenario will unfold Tuesday night through
Wednesday night as a strong clipper low passes by just to our north.
There continues to be enough spread in model guidance to bring
considerable uncertainty to the forecast in terms of snowfall
amounts, precipitation type, and wind potential.

Tuesday evening, a brief window of lake effect snow northeast of
Lake Erie and Lake Ontario ahead of the clipper system may bring a
few inches of snow to the Niagara Frontier (including the Buffalo
Metro area) and northern Jefferson County. Ongoing warm advection
and lowering inversion heights ahead of the clipper will then shut
down the lake response overnight.

The surface low will likely pass just north of the area across
southern Ontario Wednesday. The GFS remains on the southern edge of
the guidance envelope, taking a weaker low directly over Lake Erie
and Lake Ontario. If this were to verify, there would be much less
wind, and precip type would stay snow for a greater share of the
event. This low is not favored climatologically, and will thus favor
the farther north solutions seen in other guidance.

A period of snow will break out late Tuesday night through Wednesday
morning in the warm advection and isentropic upglide ahead of the
system. Assuming the farther north track verifies, lower elevations
of Western and Central NY will then mix with, or change to rain for
a time Wednesday, while the high terrain of the Southern Tier has a
better chance of remaining all snow, and also the higher terrain
east of Lake Ontario. The lower elevation rain would then change
back to snow Wednesday evening as cold advection ramps up following
the passage of the clipper cold front, with wrap around upslope snow
and the start of lake effect adding some additional accumulations
Wednesday night.

As far as accumulations go, the greatest snow amounts will be found
across the higher terrain of the Tug Hill Plateau and western
foothills of the Adirondacks where upslope will enhance QPF, and
precipitation is most likely to remain all snow. This area may see
totals of 8-12+" from early Wednesday morning through Thursday
morning. These higher amounts would be limited to the high terrain,
with the surrounding lower elevations of the eastern Lake Ontario
region seeing 3-6" accumulations.

Across Western NY, total accumulations from late Tuesday afternoon
through Thursday morning may reach the 3-6" range across the Niagara
Frontier, and 4-9" across the higher terrain of the western Southern
Tier. It is important to note that this will fall in 3 different
batches, lake effect Tuesday evening, then warm advection snow late
Tuesday night/early Wednesday morning, then wrap around snow and
lake enhancement Wednesday night. Each of these phases will produce
a few inches each. There will be melting during the day Wednesday
when temperatures rise well above freezing, especially across lower
elevations.

It will turn windy as this system moves through the area, but
uncertainty with low track, intensity, and associated wind fields
makes this a highly uncertain wind forecast. If the farthest north
and strongest solutions of the NAM/HRRR verify, we can expect high
end Wind Advisory or low end warning criteria gusts (55+mph)
northeast of Lake Erie Wednesday, while the farther south and weaker
GFS solution would keep winds well below wind advisory criteria.
Most model solutions are weaker than the worst case NAM/HRRR, so for
now we kept forecast wind gusts near the low end of advisory range
northeast of Lake Erie but expect adjustments as the event nears and
forecast certainty increases.

Thursday through Thursday night cold air will pour back into the
eastern Great Lakes, supporting accumulating lake snows southeast of
the lakes. There is typical uncertainty with wind direction and snow
amounts at this time range, but in general expect the potential for
moderate snow accumulations across the western Southern Tier off
Lake Erie, and near or just east of Rochester to Oswego County off
Lake Ontario.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
An active and cold pattern will continue Friday through early next
week as a deep longwave trough remains over eastern North America.
This trough will continue to support below average temperatures and
almost daily chances of snow from a combination of clipper systems
and lake effect.

Model guidance continues to show considerable run to run differences
with the synoptic setup through the weekend, which results in
uncertainty with respect to lake effect band placement and
intensity. In general, the very progressive pattern with frequent
clipper shortwaves will likely prevent wind direction and band
placement staying the same for any length of time. This will limit
the potential for a large lake effect event, but also spread the
wealth of accumulating snow to a multitude of different wind
directions and locations over time.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Mainly VFR through early Tuesday afternoon as surface high
pressure over the region gradually slides south and east to the
Eastern Seaboard. Winds will generally remain under 5kts through
tonight.

Land-breeze convergence and lake enhancement will likely cause
patchy low VFR clouds to develop near the southern shoreline of Lake
Ontario tonight, which will then move northward as the prevailing
flow becomes southerly overnight. A localized band of snow is
expected to be develop as well first in the vicinity of KFZY before
it too moves northward. Inland extent should be limited, but will
cover the possibility of a few snow showers reaching KART with a
PROB30 group.

Southerly winds increase on Tuesday as a clipper system passes to
the north of the region. Snow is expected to begin overspreading the
forecast area from the west after about 16z, with VFR deteriorating
to MVFR (cigs/vsbys) and IFR/LIFR (vsbys). South-southwest wind
gusts to 30kts will be possible at KBUF and KIAG after 18z.

Outlook...

Tuesday night...Mainly MVFR/IFR with snow potentially mixing with
rain late in the night.

Wednesday...VFR/MVFR with rain and snow showers. Breezy, with gusts
20-30kts in many areas. Gusts to 35kts possible at KBUF/KIAG.

Thursday...VFR, with MVFR/IFR in scattered to numerous snow showers.

Friday and Saturday...MVFR/IFR east of the lakes with snow
showers likely. MVFR/VFR outside the main lake effect areas.|

&&

.MARINE...
High pressure across the lakes this afternoon will shift southeast
of the lakes tonight with light winds and minimal wave action.

The offshore flow will increase and begin to turn southwesterly as a
weak system moves east of the Upper Great Lakes Tuesday, which will
then be followed by a more potent area of low pressure on Wednesday.
Depending upon the track of the surface low, gales are possible
Tuesday - Wednesday, with Wednesday the more favorable day,
especially over Lake Erie.

Westerly winds will subside below gale force later Wednesday night
into Thursday, though remain elevated through the end of the week.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Winter Storm Watch from late Tuesday night through Thursday
     morning for NYZ006>008.
MARINE...None.

&&

$$

SYNOPSIS...PP/Thomas
NEAR TERM...PP
SHORT TERM...Hitchcock
LONG TERM...Hitchcock
AVIATION...PP
MARINE...PP/Thomas