WX in text

527
FXUS61 KBUF 112347
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
647 PM EST Thu Dec 11 2025

.SYNOPSIS...
Locally heavy lake effect snows will persist southeast of the lakes
through this evening into tonight. The lake snows will weaken by
Friday morning off Lake Erie, but will continue through Friday east
of Lake Ontario with some additional moderate accumulations
expected. Another fresh batch of cold air will then arrive over the
weekend, likely supporting another round of accumulating lake effect
snow east of the lakes.

&&

.NEAR TERM /THROUGH FRIDAY NIGHT/...
Locally heavy lake effect snow will continue southeast of the lakes
this evening...thanks to a favorable background environment (a
WNW flow of cold air with 850 mb temps in the negative mid-teens
Celsius)...sufficiently deep moisture...and a fairly deep
dendritic growth zone embedded within the cloud bearing layer.
Environmental conditions will then become less favorable off
Lake Erie tonight... while remaining supportive of continued
moderate lake snows east of Lake Ontario Friday...before these
also weaken Friday night. Diving more into the forecast
details...

Off Lake Erie...

Northwesterly flow will continue to support fairly widespread lake
enhanced upslope snow showers southeast of the lake through the
first half of tonight. The heavier snow will be closely tied to a
mobile upstream connection to Lake Huron, which will meander back
and forth across the western Southern Tier and far southern Erie
County. Expect additional accumulations of 3-6 inches within the
most persistent lake snows through this evening, with the lake snows
and any resulting accums then markedly diminishing overnight as the
the deeper synoptic-scale moisture gets stripped away and inversion
heights fall...with just some spotty light snow showers and flurries
leftover by daybreak Friday. These will then probably dissipate
altogether for a time Friday...with a few more snow showers then
possibly redeveloping and drifting north across the Buffalo metro
area and Niagara Frontier late Friday and Friday night (with only
very minor accums of under an inch) as the low level flow backs to
southwest and then south-southwest out ahead of an approaching
clipper system...thereby allowing for a period of increased fetch
across the lake. Very late Friday night...the lake effect snow
showers may start to become better organized again across Niagara
county as the cold front trailing from the clipper approaches far
western New York.

Off Lake Ontario...

Mean WNW flow around 290 degrees will focus the heaviest LES bands
into eastern Wayne and northern Cayuga counties...then into the
Syracuse area through tonight. The heaviest band of snow will
continue to be tied to the upstream Georgian Bay connection. Expect
additional accumulations of 3-6" in the heaviest bands, most likely
from far eastern Wayne County to near Cato and then into the
Syracuse area. Farther west, somewhat lower accumulations are
expected along the Route 104 corridor in western and central Wayne
County. In Monroe County, the western end of the band will produce
another 1-3" into tonight mainly along and north of Route 104.

While the band should weaken for a period overnight as mid-level
moisture temporarily thins out...it will become at least somewhat re-
invigorated early Friday morning as moisture deepens once again and
fetch across the lake increases in concert with the beginning of a
gradual backing of the low level flow...which will slowly take the
band north across Oswego county during the course of Friday and
Friday evening. The increased moisture and fetch appears likely to
result in another round of at moderate (4-8") accumulations across
much of Oswego county Friday into Friday evening...with lower
amounts of 2-4" possible across neighboring portions of Jefferson
and Lewis counties.

With the above in mind...a new Winter Weather Advisory has been
issued for Oswego county from 4 am Friday through 1 am Saturday.
While it is also possible that the existing warnings for Wayne/
Northern Cayuga counties may eventually need to be extended a bit
deeper into Friday morning to cover the departure of the lake
snows...will leave that for later to allow the mid shift to take
observed radar trends into account later on tonight.

Later Friday evening and overnight...the band will weaken while
rapidly lifting north across Jefferson county with further backing
of the low level flow to SSW and an increasing shear...resulting in
some additional minor accumulations of an inch or less from the
Watertown area northward.

Outside of the main lake effect areas, expect just a few passing
scattered snow showers through this evening with spotty very minor
accumulations...with a few more general scattered snow showers then
becoming possible across far WNY late Friday night out ahead of the
approaching cold front. Otherwise northwest winds gusting to 20-30
mph (locally higher along the immediate SE shore of Lake Ontario)
will diminish tonight as high pressure builds in from the Ohio
Valley.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
The next clipper system diving southeast across the Great Lakes
Saturday morning will introduce a cold front to pass from west to
east across the region. However ahead of this front, deeper moisture
and increasing convergence will support a band of lake enhanced snow
to form northeast of Lake Erie Saturday morning. This will produce a
quick 1-3 inches across Niagara, Erie and far northern Chautauqua
counties with a localized 2-4 inches falling across the City of
Buffalo. As the front passes east, a general light snow will fall
across the region with amounts of around an inch. Similar to
northeast of Lake Erie, a band of lake enhanced snow will develop
across northern Jefferson county late Saturday morning/noon time,
supporting an uptick in snowfall totals of around 1-2 inches.

Winds will veer from southwest to westerly Saturday night. Lingering
moisture and colder air will begin to advect across the region
resulting in some light upslope snows off of Lake Erie impacting the
Boston Hills and the Chautauqua Ridge where a couple of inches of
snow will be possible. Meanwhile to the east of Lake Ontario, the
well aligned westerly flow along the long axis of the lake, combined
with deeper moisture associated with a nearing mid-level low raising
equilibrium heights to around 8-10k feet and strong lift through the
saturated dendritic growth zone will support a well developed lake
effect band capable of producing several inches of snow to set up
across the Tug Hill. A mid-level trough will slide across the region
Sunday, supporting winds to further veer to the northwest by Sunday
night, thus resulting the lake band to shift south and become
disorganized into multiple bands. This all being said, a Winter
Storm Watch is in effect from 1PM Saturday through 1PM Sunday for
Jefferson, Lewis, and Oswego counties.

Outside of the lake effect snow potential Sunday, with the
aforementioned trough axis`s passage a light widespread snow will be
possible, with some upslope enhancement across the western Southern
Tier Sunday.

Strong high pressure will move east across the Central Plains to the
lower Ohio Valley Sunday night. While this will try to dry out much
of the area, the cold northwest winds will support some localized
lake effect snow/upslope showers to persist south-southest of Lakes
Erie and Ontario.

In addition to the lake effect potential, a plume of cold air will
push across the region this weekend, supporting temperatures to be
well below average Sunday and Sunday night.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Surface high pressure south of New York State will slide east Monday
and Monday night causing northwest winds to back to the west.
Meanwhile, a mid-level trough will pass across the region. Overall
this will support another round of light widespread snow to fall
across the region, with some localized lake effect snow showers
southeast of Lakes Erie and Ontario and northwesterly upslope
showers.

Tuesday, lingering lake effect snow will dissipate as a warm front
passes across the region, with temperatures aloft at 850mb warming
up to (+2 to +4 degrees Celsius). Additionally with the front
passing across the region late Tuesday and Wednesday expect rain
showers to spread across the region.

The next low pressure system will cross the Great Lakes Thursday,
supporting continued chances for rain showers.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Lake snows southeast of Lake Erie will continue this evening with
areas of IFR/LIFR (including at KJHW). These will then diminish to
some leftover scattered light snow showers and flurries
overnight...before temporarily dissipating Friday morning. Later
Friday as the flow across Lake Erie backs to the southwest...the
increasing fetch across the lake may allow for a few more snow
showers to redevelop and move across the KBUF terminal late in the
day...with brief/localized IFR/MVFR possible there.

Off Lake Ontario...the lake snows and associated IFR/LIFR will be
found from just north/east of KROC to just southwest of KFZY and
extending into the KSYR area through tonight...before slowly
drifting north across Oswego county (including KFZY and vicinity)
during Friday. Unlike the Lake Erie lake snows...the Lake Ontario
lake snows will remain capable of moderate snowfall and IFR/LIFR
conditions through the day Friday.

Outside of the main lake effect areas, a few scattered snow showers
will be possible at times into this evening with brief/localized
IFR. Otherwise the current mix of MVFR/VFR ceilings will gradually
give way to general VFR conditions as we push through tonight and
Friday...with the MVFR ceilings lingering longest across the higher
terrain east of both lakes. Lingering gusty northwest winds (to 25-
30 knots, and locally to 35 knots along the southeast shore of Lake
Ontario) will diminish this evening.

Outlook...

Friday night through Saturday...VFR/MVFR with scattered snow
showers. Local IFR in lake effect snow northeast and east of the
lakes.

Sunday...VFR/MVFR with scattered snow showers. Local IFR/LIFR in
lake effect snow east of the lakes at the start of the day shifting
to areas southeast and south of the lakes.

Monday...VFR/MVFR with scattered snow showers. Local IFR in lake
effect snow east and southeast of the lakes.

Tuesday...VFR/MVFR with a chance of snow showers east of Lake
Ontario.

&&

.MARINE...
Moderately strong northwest flow will continue into early this
evening in the wake of a departing clipper system. This will support
some potential for very low end gales on the east half of Lake
Ontario. While sustained winds may only run around 30 knots, there
will be frequent enough higher gusts to justify maintaining the Gale
Warning. For western Lake Ontario and Lake Erie, high end Small
Craft Advisory conditions will continue into this evening.

Winds will then gradually diminish from west to east late tonight
through Friday as high pressure builds in from the Ohio Valley and
central Great Lakes. Any lighter winds will be short lived
however...with another period of high end Small Craft Advisory to
marginal gales expected over the weekend.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Winter Weather Advisory until 7 AM EST Friday for NYZ003.
     Lake Effect Snow Warning until 7 AM EST Friday for NYZ004-005.
     Winter Weather Advisory from 4 AM Friday to 1 AM EST Saturday
     for NYZ006.
     Winter Storm Watch from Saturday afternoon through Sunday
     afternoon for NYZ006>008.
     Winter Weather Advisory until 4 AM EST Friday for NYZ012-021.
     Lake Effect Snow Warning until 4 AM EST Friday for NYZ019-020-
     085.
MARINE...Small Craft Advisory until 4 AM EST Friday for LEZ040-041.
         Small Craft Advisory until 4 AM EST Friday for LOZ030.
         Small Craft Advisory until 10 AM EST Friday for LOZ042.
         Gale Warning until 10 PM EST this evening for LOZ043>045-
         063>065.

&&

$$

SYNOPSIS...AR/Hitchcock/JJR
NEAR TERM...Hitchcock/JJR
SHORT TERM...EAJ
LONG TERM...EAJ
AVIATION...AR/Hitchcock/JJR
MARINE...AR/Hitchcock/JJR

NWS BUF Office Area Forecast Discussion