041
FXUS61 KBUF 071837
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
137 PM EST Sun Dec 7 2025

.SYNOPSIS...
A passing low pressure system will continue to bring light to
locally moderate snowfall to the region through the afternoon, which
will diminish through this evening and tonight. Colder air wrapping
in behind this sytem will make for a rather frigid but mostly dry
start to the workweek. Increasing temps will accompany increasing
winds and chances for snow and rain at times Tuesday into Wednesday.
Unsettled weather lingers Thursday through the end of the week with
persistent chances for snow, particularly east of the lakes.

&&

.NEAR TERM /THROUGH MONDAY NIGHT/...
A weak area of low pressure moving east across Lake Ontario this
afternoon will reach the Gulf of Maine this evening, then strengthen
slightly as it moves across Atlantic Canada tonight. Weak mid-level
height falls coupled with a thin plume of synoptic moisture and an
approaching cold frontal boundary will continue to produce light but
widespread snowfall across the eastern Great Lakes region. 850H
temps are cold enough out ahead of the front with the increasing
moisture such that some localized enhancement from the lakes is
likely east/northeast of the lakes. Overall coverage/intensity of
the snow should begin to wind down across WNY through the afternoon
hours as drier air begins to wrap back in behind the passing low. As
the flow becomes northwesterly and further cools with the front,
light lake enhanced/upslope snows or flurries may develop south of
the lakes through this evening. This activity may linger through
much of tonight across the southern Genesee Valley and Finger Lakes
region, and across the Tug/Western Dacks. DGZ moisture should be
sufficently depleted by this point such that additional amounts will
be very minor.

Forecasted snowfall amounts through this evening continue to be
highest east of Lake Ontario, particularly across the higher terrain
south and east of Watertown where an additional 3-4" may fall.
Surrounding areas may pick up another 2-3". Across WNY, totals will
overall be much lower, up to an inch or less for most places with 2-
3" possible across the higher terrain of Chautauqua, S. Erie, and N.
Cattataugus.

Expansive sfc high pressure building squarely over the Great Lakes
ahead of a mid-level ridge will bring mainly dry weather to the
forecast area Monday and Monday night. There may be a spot snow
shower near the eastern Lake Ontario shoreline Monday night as the
flow becomes southwesterly with the passing ridge. Otherwise, it
will be a cold start to the new workweek as 850H temps plummet to
either side of -17C behind the cold front. This will translate
to sfc high temps in the teens and low 20s Monday with single
digit lows in most areas Monday night.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Tuesday and Tuesday evening high pressure will slide off the
Atlantic coastline...while a compact but vigorous shortwave trough
makes its way from the Upper Great Lakes to southern Quebec while
also shearing out over time. At the surface...its corresponding
modest surface low will also slowly weaken as it follows along a
similar path...though at the same time will still manage to push its
attendant warm front northeastward across our area. Isentropic
upglide/DCVA out ahead of these features along with low level
convergence at the nose of an associated 50-55 knot low level jet
coupled with increasing moisture to produce scattered to numerous
snow showers across the area between late Tuesday morning and
Tuesday evening...with these lasting roughly 6-9 hours at any given
location...and possibly ending with a little lake enhancement
northeast of the lakes. Pcpn chances still appear to be highest near
the Canadian border and lowest across interior portions of the
Finger Lakes...with accums from the snow showers generally on the
order of 1-2"...save for locally higher amounts of up to around 3"
across the Tug Hill...and lower amounts of under an inch across the
interior of the Finger Lakes Region. Otherwise the warm advection
pattern will result in high temps climbing back into the lower to
mid 30s for the most part on Tuesday...though it will feel colder
owing to an increasing south to southwesterly wind that will gust to
25-35 mph at times...with the highest gusts found from the Lake Erie
shoreline northeastward across Niagara and northern Erie counties.
This being said...the warm advection regime should help prevent the
much higher winds aloft from mixing down to the surface.

The snow showers from this first system will barely have a chance to
exit our area Tuesday night...before more widespread pcpn associated
with the next (and notably stronger) surface low arrives for the
second half of Tuesday night and Wednesday. With this package...the
guidance suite continues to slowly converge on the idea of taking a
nearly steady-state to slowly deepening low either over or just
north of Lake Ontario between Wednesday and Wednesday evening...with
its trailing cold front crossing the area Wednesday evening.

Provided such a track actually verifies...this would result in
widespread light to moderate snow overspreading the area later
Tuesday night...with steady warm air advection then forcing a
changeover to mainly rain across the lower elevations and a rain/snow
mix across the higher terrain late Tuesday night and Wednesday...
with the latter then changing back to all snow following the passage
of the trailing cold front Wednesday night. While this scenario
would result in only some minor accumulations at the lower
elevations...it would be supportive of a longer period of
accumulating (and potentially headline-worthy) snow across the
higher terrain of the Southern Tier and Tug Hill/western Adirondack
foothills...with the greatest accumulations most likely across the
higher terrain east of Lake Ontario. With this in mind...we`ll be
adding a mention of this potential to the Hazardous Weather Outlook
with this package.

Also on Wednesday...yet another 50-55 knot low level jet will cross
areas south of Lake Ontario in advance of the surface low/trailing
cold front...though with widespread pcpn and steady warm advection
in place thermal profiles again don`t look favorable for fully
mixing these stronger winds from aloft down to the surface. This
being said...gusts to 30-40 mph still appear to be a reasonable bet
at this point...with these again strongest closer to Lake Erie and
across portions of the Niagara Frontier. Fortunately...the stronger
winds aloft look to depart prior to the arrival of the trailing cold
front...which would greatly limit the risk for any stronger winds in
its wake.

Following the passage of the cold front...a westerly to west-
northwesterly flow of colder air will then overspread our region
Wednesday night...with consensus 850 mb temps dropping to -10C to
-12C by Thursday morning. This will allow for some areas of lake
effect snow to develop east and east-southeast of the lakes...though
a period of mid-level drying in the wake of the low/cold front may
help to keep these at least somewhat limited in scope initially.
Elsewhere...the synoptic pcpn should diminish to some leftover
scattered snow showers.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
In the longer term portion of the forecast...longwave troughing will
deepen across the eastern two-thirds of North America Thursday
through Friday night...then will remain in place through next
weekend as additional shortwave impulses circulate through and
enhance the mean larger-scale trough. During this time there will
also be the potential for at least a couple of clipper-type systems
to cross our region in association with the above-mentioned
shortwave impulses...though timing and placing these features
remains rather difficult this far out in advance...with plenty of
variability noted in the track and timing of these features in
the guidance over the past few days.

Given the overall pattern...what is much more certain is that 850 mb
temperatures will average between -10C and -15C throughout this
period...thereby ensuring below normal temperatures and providing an
environment thermally conducive for areas of lake effect snow
downwind of the lakes. This being said...uncertainty in the
evolution of the main low-level synoptic features and consequently
the low level wind field precludes trying to pin down the location
of these at this time range. Outside of any lake snows it will
generally be dry...save for any snow showers/snow that might
accompany the passage of the aforementioned clipper systems.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
Variable flight conditions across the eastern Great Lakes region
this afternoon as a weak low pressure system moves east across Lake
Ontario and pushes a cold front southward. This system is bringing
light but widespread snowfall to the area with MVFR/IFR cigs and
vsbys. Embedded lake enhancement will cause localized LIFR or lower
vsbys east to northeast of the lakes this afternoon, especially off
Lake Ontario. This may impact KBUF through about 19z and KART
through 22z or 23z. Areas further inland from the lakes across the
Finger Lakes, Genesee Valley and Southern Tier may see more frequent
periods of VFR into this evening.

Winds will turn northwesterly behind the passing system later this
evening and tonight. VFR to MVFR lake clouds will likely develop
south of the lakes with a few light snow showers or flurries, though
overall coverage of snow should rapidly diminish. This activity may
persist through much of tonight between KROC and KFZY.

A more widespread improvement from MVFR/VFR to VFR with calming
winds is anticipated for Monday as high pressure builds over the
Great Lakes.

Outlook...

Tuesday...VFR to IFR with increasing chances for light snow,
possibly mixing with rain Tuesday 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...MVFR/IFR east of the lakes with snow showers likely.
MVFR/VFR outside the main lake effect areas.

&&

.MARINE...
A weak passing low pressure system and subsequent cold frontal
passage will cause northwesterly winds to increase on the nearshore
waters this afternoon and remain elevated through tonight. Small
Craft Advisories will go into effect on both lakes and the lower
Niagara River as outlined below.

High pressure will build across the lakes Monday, then shift
southeast of the lakes Monday night. This will cause winds and
subsequent wave heights to diminish before turning offshore.

The offshore flow will increase and begin to turn southwesterly as
another weak system moves east of the Upper Great Lakes Tuesday,
which will then be followed by a more potent area of low pressure
and LLJ further south on Wednesday. This may bring low-end gales to
Lake Erie, with Wednesday being the more favorable setup between the
two days.

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

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory until 3 AM EST Monday for LEZ040-041.
         Small Craft Advisory until 3 AM EST Monday for LOZ030.
         Small Craft Advisory until 10 AM EST Monday for LOZ042>044.
         Small Craft Advisory from 10 PM this evening to 3 AM EST
         Monday for LOZ045.

&&

$$

SYNOPSIS...PP
NEAR TERM...PP
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...PP
MARINE...PP