Forecast Discussion

390
FXUS61 KBUF 271143
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
643 AM EST Thu Nov 27 2025

.SYNOPSIS...
A cold cyclonic flow across the Lower Lakes will support locally
heavy lake effect snows east and then southeast of the lakes today
through Friday night, along with gusty winds which lasts through the
day Friday. Lake snows will begin to diminish Friday night into
Saturday as high pressure brings a brief period of dry weather
before another system brings wind and mixed precipitation by
Sunday.

&&

.NEAR TERM /THROUGH FRIDAY/...
...ACCUMULATING LAKE EFFECT SNOWS TO CONTINUE OFF BOTH LAKES THROUGH
FRIDAY NIGHT...

A cold cyclonic flow across the lakes will continue to support lake
effect snows off both lakes today. Winds will continue to veer to
the west and then eventually the northwest, lakes snows will become
focus east and then southeast of both lakes through Friday night.


Additionally...a combination of a tight pressure gradient across the
Lower Lakes and a strong LLJ (+45 knots) aloft will support surface
wind gusts of 35 to 45 mph, and up to 50 mph closer to the lake
shores. The strong winds will result in some blowing/drifting snow
in lake effect areas, although the wet/slushy nature of the snow
will help to mitigate this to some extent.

Off Lake Erie...

Lake snows focused east and southeast of the lake as boundary layer
flow further veers to the west then northwest by mid-morning, lake
snows will concentrate across the higher terrain inland from the
lake, including the Boston Hills, western Wyoming County, and the
ridges of the western Southern Tier. With the added help from
upstream support (Lake Huron) and strong flow aloft it will carry
lake snows all the way inland into Allegany County where decent
accumulations is anticipated through Friday.

Overall...snowfall totals of 12-20" will be possible within the most
persistent snows, with locally higher amounts in spots.


Off LAKE ONTARIO...

A disorganized band connected to Lake Erie will continue to impact
parts of the area this morning, bringing some minor accumulations to
to Jefferson Co. and the Tug hill region. Another better organized
band across the St. Lawrence River Valley will drop south later
today (late afternoon) and then rapidly intensify as a
secondary front approaches Lake Ontario. It will be this band
that will bring 1-2" per hour snowfall rates across Jefferson and
the Tug Hill region. This will occur as the full fetch of the lake
comes into play and then is boosted by upstream connections. We may
even see snowfall rates approach 3" per hour as flow veers to the
west then northwest tonight into Friday. Eventually...lake snows off
Lake Ontario will settle across Wayne, N. Cayuga, and S. Oswego on
Friday.

One thing to note...there is some indication we may see the band off
Lake Ontario as it pushes south impact the `entire` south shore
tonight, with a few inches before re-organizing again across the
counties (Wayne to S. Oswego) mentioned above on Friday.

Storm snowfall totals of 12 to 22 inches are expected across
the higher terrain of the Tug Hill Plateau and 8 to 12 inches
for the western foothills of the Adirondacks. Marginal
temperatures will likely keep accumulations much lower for the
low elevations of Jefferson County close to Lake Ontario and the
Saint Lawrence River, perhaps only a few slushy inches. Later
in the event southeast of Lake Ontario, around 10 to 14 inches
is possible for portions of eastern Wayne, northern Cayuga, and
southern Oswego counties, where the lake band will become the
most organized southeast of the lake.

Otherwise...areas not impacted by the main lake effect bands will
see periodic snow showers with some minor accumulations and brief
reduced visibilities through Friday.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
Cool, cyclonic flow will continue across the eastern Great Lakes
region Friday night through Saturday. An upper level low over
eastern Quebec will lift northward and the associated trough will
begin to flatten across the Great Lakes region. A moderately, strong
northwest flow will continue to direct lake effect snow showers
southeast of Lake Erie and Lake Ontario, however diminishing deep
moisture from west to east and and surface high pressure building
from the southwest will diminish lake effect snow showers through
Saturday. Additional snowfall amounts of 1 to 3 inches southeast of
Lake Erie and 2 to 6 inches southeast of Lake Ontario are expected
through Friday night.

High pressure will briefly build into the region Saturday before
moving off the east coast Saturday evening. A very brief period of
dry weather is expected late Saturday, and into Saturday evening for
the Eastern Lake Ontario region. Another upper level trough will
move across the Plains and an area of low pressure is expected to
near the central Great Lakes region late Saturday night. A warm
front will move into the forecast area, and a light snow is expected
to move into western and north central NY.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
The pattern will remain progressive Sunday through the first half of
next week. An area of low pressure is expected to cross the Central
Great Lakes dragging a cold front across the forecast area. Deep
moisture tied to this system will likely produce rain and snow
showers. Cool, westerly flow will then likely transition showers to
lake-enhanced snow showers Monday. The next system has the potential
to deepen near the southeastern U.S. coastline. This could bring
precipitation to the region, however confidence is low. Behind this
system, cooler air will filter across the region, keeping
temperatures below normal as we move into December.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
As flow veers to the west and then northwest lake snows will impact
terminals east and then southeast of the lakes today to include KROC
to KFZY, and also KJHW through tonight.

It will also be continued very windy today with gusts up to 35 to 45
knots across area terminals.

Otherwise...outside of the main lake effect terminals will see a mix
of VFR-MVFR conditions, with periodic IFR conditions within
heavier snow showers.

Outlook...

Friday...VFR/MVFR with a chance of snow showers. Heavier lake effect
snow with IFR/LIFR southeast of Lake Erie and Lake Ontario. Very
windy.

Saturday...Lake effect snow showers southeast of the lakes with
local MVFR/IFR early, improving to VFR in the afternoon.

Sunday...MVFR with a rain/wet snow mix. Very windy.

Monday...Mainly VFR. Local IFR in limited lake effect snow east of
Lake Erie and Lake Ontario.

&&

.MARINE...
A deep low pressure will move slowly east across Quebec over the
next few days, producing an extended period of gales on Lake Erie
and Lake Ontario. Solid Small Craft Advisory conditions will be
found on the Niagara River and Saint Lawrence River. Winds will
finally diminish below gales Friday night, then quickly drop off
Saturday as high pressure builds into the eastern Great Lakes.

Another strong low pressure system is forecast to move across the
central Great Lakes Sunday. This may bring another round of gales to
Lake Erie and Lake Ontario Sunday through Sunday night.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Wind Advisory until 1 AM EST Friday for NYZ001>007-010>012-019-
     085.
     Lake Effect Snow Warning from 1 AM Friday to 7 AM EST Saturday
     for NYZ004-005.
     Lake Effect Snow Warning from 4 PM this afternoon to 7 AM EST
     Saturday for NYZ006.
     Lake Effect Snow Warning until 1 AM EST Saturday for NYZ007-
     008-012-019-020-085.
     Lake Effect Snow Warning until 1 AM EST Saturday for NYZ021.
MARINE...Small Craft Advisory until 10 PM EST Friday for LEZ020.
         Gale Warning until 10 AM EST Friday for LEZ040-041.
         Small Craft Advisory until 10 PM EST Friday for
         LOZ030.
         Gale Warning until 7 PM EST Friday for LOZ042>045-062>065.
         Small Craft Advisory until 10 PM EST this evening for
         SLZ022-024.

&&

$$

SYNOPSIS...AR
NEAR TERM...AR
SHORT TERM...HSK
LONG TERM...HSK
AVIATION...AR
MARINE...AR/Hitchcock

NWS BUF Office Area Forecast Discussion