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FXUS61 KBUF 131150
AFDBUF
Area Forecast Discussion
National Weather Service Buffalo NY
650 AM EST Sat Dec 13 2025
.SYNOPSIS...
Our brief break in the active weather will come to an abrupt end
today as a strong cold front plows across the region. Lake enhanced
snow will develop toward morning across Niagara County ahead of an
arctic cold front, with a quick few inches of snow possible
northeast of Lakes Erie and Ontario through early this afternoon as
the front crosses the region, followed by lake snows quickly
shifting east of the lakes in the wake of the frontal passage. Much
colder air moves back into the area behind the front bringing
another round of locally heavy lake snows east and southeast of the
lakes late today through Sunday night.
&&
.NEAR TERM /THROUGH TONIGHT/...
A Clipper system will track across southern Quebec today through
tonight while sending an attendant arctic cold front through western
and northcentral NY producing a quick few inches of lake enhanced
snow as it crosses the area this morning through early afternoon,
with another shot of much colder air poised to pour across the
region later today and tonight in the wake of the frontal passage
setting the stage for another round of heavy lake snows east and
southeast of the lakes. Lake effect snow details follow just below...
Off Lake Erie...
Latest surface observations show Arctic cold front pushing east
across southwestern Ontario Province with some general scattered and
lake enhanced snow showers developing across western NY in advance
of the boundary. South-southwesterly winds ahead of the boundary
will direct the lake enhanced snow shower activity north-northeast
of the lake across over the Niagara Peninsula and western Niagara
Frontier. This weak lake response will eventually start to
strengthen toward daybreak as deeper moisture pushing into the area
combined with increasing surface convergence ahead of the front will
lead to a band of lake enhanced snow developing north-northeast of
the lake, initially across western Niagara County, with some minor
accumulations possible across these areas by daybreak.
Arctic front then plows across the area this morning through early
afternoon, pushing this band of lake enhanced snows further south
and east across the area, into the Boston Hills and Southern Tier by
midday. Expect a burst of snow northeast of Lake Erie along and just
ahead of the boundary with a quick of 1-3 inches of snow possible
across the Buffalo Metro area during the mid to late morning hours.
This band will weaken as it presses further east and southeast as it
loses lake influences. Winds quickly veer west in the wake of the
frontal passage with lake effect snows setting up east of the lake
later this afternoon through tonight. A Lake Effect Snow Warning
remains in effect for Southern Erie, Chautauqua, and Cattaraugus
counties. Expect localized snowfall amounts of 3-5 inches from late
this afternoon through tonight in the most persistent snows, with
much less elsewhere.
Off Lake Ontario...
Latest surface observations show Arctic cold front pushing east
across southwestern Ontario Province. South to South-southwest winds
ahead of the boundary will continue to direct any lake enhanced snow
shower activity north-northeast of the lake across the Thousand
Islands region and Canada where it will persist through daybreak.
Lake enhanced snow showers will begin to intensify mid to late
morning north-northeast of the lake as deeper moisture starts to
move into this region ahead of the approaching Arctic front.
Boundary will plow across the eastern Lake Ontario region early to
mid afternoon with a burst of heavy snow producing a quick 1-3
inches across the North Country and Tug Hill region, including the
Watertown area. Winds quickly veer west behind the front sending
lake snows east of the lake. A fetch down the long axis of the lake,
deepening of moisture and colder air, and equilibrium levels rising
to around 10K feet with strong lift through a saturated DGZ will
result in an intense band of lake effect snow developing this
evening due east of the Lake centered on the Tug Hill, before slowly
sagging south with heavy lake snows mainly impacting Oswego County
during the second half of tonight as flow veers slightly. Snowfall
rates may reach 2-4" per hour in the most intense portion of the
band, especially later tonight across Oswego County. Snowfall
amounts of 8-14 inches will be possible tonight in the most
persistent snows. Lake Effect Snow Warnings remain in effect for all
of the eastern Lake Ontario region as outlined below.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Main focus through the short term will be ongoing lake effect snow
Sunday through Sunday night, then another clipper shortwave Monday
which will likely become lake enhanced east of the lakes.
Lake induced equilibrium levels will peak at nearly 15K feet Sunday
morning just ahead of a secondary arctic front, when synoptic scale
moisture and ascent are greatest. The W/WNW flow regime early Sunday
will quickly become NNW following the passage of the secondary
front, ending the single band configuration of lake effect snow and
forcing a more widespread spray of light snow showers.
Off Lake Erie...
The setup is less favorable over Lake Erie, with more limited
moisture and fetch. Sunday morning, WNW flow will continue to
support some mainly light upslope snow across the higher terrain of
the Chautauqua Ridge and Boston Hills. A Lake Huron connection will
likely move south across the area as well, providing locally
enhanced snowfall rates and amounts. Boundary layer flow will
continue to veer through the afternoon as the secondary boundary
moves south. Increased convergence along the passing boundary will
likely enhance bands of snow briefly across the western Southern
Tier. The Lake Huron connection will move west of the area into NW
PA by early Sunday evening, and shortening NNW fetch will allow the
lake effect snow to taper off to just light snow showers across the
higher terrain.
Additional accumulations Sunday through Sunday evening will be in
the 2-4"/3-5" range across the higher terrain. This will bring
totals into the 8-12" range in locations where bands persist the
longest, most likely on the Chautauqua Ridge and Boston Hills.
Off Lake Ontario...
A much more robust setup will continue through Sunday morning at the
east end of the lake, focusing on Oswego and far northern Cayuga
counties. There is still some uncertainty with how fast the band
will progress southward Sunday morning, but in general expect a band
in central or northern Oswego County early in the morning to focus
across southwest Oswego County and far northern Cayuga county for
several hours mid morning through midday. Forecast BUFKIT soundings
over Lake Ontario show an ideal setup for large dendrite
conglomerates with a deep mixed phase dendritic growth zone topped
by a deep supersaturated ice nuclei layer above. The forecast
anticyclonic band structure focusing into western Oswego County
Sunday morning is indicative of a band being strongly forced by a
land breeze convergence zone at the southwest corner of the lake.
These types of bands often have impressive hourly snowfall rates,
and this one could potentially produce 3-4" per hour.
The sharp secondary cold front will move south across Lake Ontario
by late morning or midday. This will shove the west-east oriented
band southward and onshore along much of the south shore of the
lake, producing a quick burst of heavy snow as it does so from
Oswego County westward to the Rochester area. Following this onshore
push, NNW flow will allow a spray of multiple bands of light lake
effect snow showers across much of the region south of Lake Ontario,
from Niagara to Oswego counties and spreading inland to well south
of the NYS Thruway. This will be much lighter intensity snow, but
will produce minor additional accumulations across much of the
region. This will continue into Sunday evening before boundary layer
flow begins to back more to the NW overnight, focusing the remaining
snow southeast of the Lake from Rochester to western Oswego County.
As far as accumulations go, additional accumulations Sunday in
Oswego and far northern Cayuga County may reach or exceed a foot,
depending on how long the band is able to remain over one location.
Wayne County can expect 1-3" for most of the county, and 3-6" in the
northeast corner of the County. Elsewhere, expect a dusting to an
inch or two in the spray of multiple bands south of the lake.
Storm totals in Oswego County will likely reach 1-2 feet in the most
persistent bands, but there is a chance of over 2 feet if the band
is able to remain stationary for long enough. 6-12" is likely in far
southern Jefferson and far western Lewis counties. This is a
scenario where the heaviest snow will likely focus close to the
lakeshore and not over the higher terrain of the Tug Hill Plateau.
Monday through Monday night, another mid level shortwave and surface
cold front will move east across the eastern Great Lakes. This
feature will produce some light synoptic snow, but the airmass
remains cold enough to support lake enhancement east and northeast
of Lake Erie and Lake Ontario. There is some potential for advisory
worthy snow amounts east/northeast of Lake Erie including the
Buffalo Metro area, and a greater chance of higher end advisory or
even low end warning amounts east of Lake Ontario.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
The very active and cold pattern will finally come to an end as we
head into the middle of next week. High pressure will move east
across the Ohio Valley to the Mid Atlantic Tuesday, with any
lingering light lake effect snow showers in the morning coming to an
end as warm advection rapidly increases. A weak frontal boundary
will cross the eastern Great Lakes Wednesday, with a chance of a few
rain or wet snow showers.
Much warmer air will arrive by Thursday as a strong Pacific trough
advances east across North America and forces strong height rises
and warm advection to spread into the Ohio Valley and eastern Great
Lakes. Temps will rise well into the 40s, with even some potential
for 50s if the rain holds off long enough. Strong low pressure will
move across northwest Ontario to James Bay, with a trailing strong
cold front crossing the eastern Great Lakes Thursday night. This
will bring a period of rain to the region. Much colder air pours
back into the Great Lakes late Thursday night and Friday, with
precip changing back to snow. There may be a brief window of lake
effect snow Friday, but this potential looks limited with a rapid
arrival of dry air by later Friday, and then another push of strong
warm advection by Saturday.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
An Arctic front over southwestern Ontario Province early this
morning will cross western NY later this morning. Before the arrival
of the boundary, we are already seeing a ramp up in general light
snow shower activity across western NY, along with some lake
enhanced snow showers northeast of the lakes under a south-southwest
to southwest flow with intermittent marginal IFR/MVFR VSBY possible
at times.
Lake enhanced snow will intensify north-northeast and northeast of
Lake Erie through mid morning as the Arctic front approaches and
crosses western NY mid to late morning. A burst of heavy snow will
produce a period of LIFR/IFR VSBY (1/4SM +SHSN) across the KIAG (13Z-
16Z) and KBUF (14-17Z) terminals. These conditions will not impact
either terminal during this entire timeframe, but is the window for
the possibility of occurrence. As the Arctic front presses further
east, similar conditions can also be expected northeast of Lake
Ontario at the KART terminal with LIFR/IFR conditions (1/4SM +SHSN)
possible sometime within a 17Z-20Z window this afternoon. Expect
lesser impacts at KROC/KJHW, although intermittent periods of
MVFR/IFR will be possible along and ahead of the frontal passage at
KROC sometime between 16Z-19Z. Intermittent periods of MVFR/IFR will
be possible at KJHW this morning as well, but especially from 18Z or
so onward as lake enhanced snows associated with the Arctic front
transition to lake effect snow showers later today and tonight as
flow veers westerly behind the front.
Outside of the lake enhanced/lake effect snows, conditions will be
predominantly VFR/MVFR with just some scattered snow showers through
mid/late afternoon. Mainly VFR conditions are then expected at all
terminals except KJHW from late today through tonight as flight
restrictions will be confined to localized lake effect areas. KJHW
will remain MVFR/intermittent IFR in lake effect snow showers
through tonight.
Winds will shift from southwest to west today while gusting 25-30
knots across much of the region.
Outlook...
Tonight and Sunday morning...VFR/MVFR with scattered snow
showers...and local IFR/LIFR in lake effect snow east of the lakes.
Sunday afternoon and Sunday night...local IFR/LIFR in lake effect
snow 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.
Wednesday...Mainly VFR.
&&
.MARINE...
Elevated southwesterly to westerly flow will be commonplace across
the Lower Great Lakes for much of the time through at least early
Monday...and for this reason Small Craft Advisories are in effect as
outlined below.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Winter Weather Advisory from 4 AM Sunday to 4 AM EST Monday
for NYZ004.
Lake Effect Snow Warning from 4 AM Sunday to 4 AM EST Monday
for NYZ005.
Lake Effect Snow Warning until 4 PM EST Sunday for NYZ006.
Lake Effect Snow Warning from 1 PM this afternoon to 1 PM EST
Sunday for NYZ007-008.
Lake Effect Snow Warning until 7 AM EST Monday for NYZ019-020-
085.
MARINE...Small Craft Advisory until 7 PM EST this evening for LEZ020.
Small Craft Advisory until 1 AM EST Monday for LEZ040-041.
Small Craft Advisory until 1 AM EST Monday for LOZ042.
Small Craft Advisory until 7 AM EST Monday for LOZ043-044.
Small Craft Advisory until 4 AM EST Monday for LOZ045.
&&
$$
SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...Hitchcock
LONG TERM...Hitchcock
AVIATION...JM
MARINE...JJR
NWS BUF Office Area Forecast Discussion
