997
FXUS61 KBUF 172349
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
649 PM EST Mon Nov 17 2025

.SYNOPSIS...
Deep low pressure over the Canadian Maritimes will withdraw
northward across Labrador through Tuesday, as high pressure and
drier air build into our region. This will result in lingering lake
effect snow showers diminishing from west to east through Tuesday
with only limited additional accumulations, some localized moderate
accumulations are expected east-southeast of Lake Ontario. Low
pressure passing by to our south may bring a few spotty light rain
and snow showers to the Southern Tier Tuesday night, otherwise dry
weather is expected Tuesday night through Thursday.

&&

.NEAR TERM /THROUGH TUESDAY/...
Deep low pressure over the Canadian Maritimes will withdraw
northward across Labrador through the period, while high pressure
will build east into our region from the Upper Great Lakes. The
resultant lessening of the current cold cyclonic flow and drying
out of our airmass will result in ongoing lake effect snow
showers southeast of the lakes generally diminishing from west
to east, though not before an expected temporary uptick in the
Lake Ontario Lake snows produces some localized moderate
accumulations ESE of that lake tonight into Tuesday morning. At
the same time, lingering spottier very light snow/flurries east
of Lake Ontario will also continue to fade, before ending
altogether tonight.

Looking a little further at the details of the lake effect...

Off Lake Erie...continued drying and lowering of the capping
inversion will in a gradually weakening of snow showers this
evening, eventually fading out overnight and early Tuesday. Expect
additional accumulations of maybe another inch to an inch and half
out of these through tonight, mainly across the higher terrain of
eastern Chautauqua and Cattaraugus counties.

Off Lake Ontario...lake effect snow showers should become a bit
better organized with the loss of diurnal influences and some
reorganization and likely result in localized moderate accumulations
of 2-4" tonight into Tuesday morning across from far eastern Wayne
County across northern Cayuga County. A Winter Weather Advisory
remains in effect for these two counties through 10 am Tuesday.
Drying and a lowering cap on Tuesday will cause the lake activity
scattered out to light snow showers and flurries, with the remains
of these reaching the Tug Hill region by late in the day as winds
turn more westerly.

Outside of the above areas...largely dry weather will prevail
through this period...with lingering brisk northwesterly winds
finally slackening after sunset tonight. Otherwise temps will
continue to average a bit below normal...with lows in the 20s to
around 30 tonight followed by highs mainly in the upper 30s to lower
40s Tuesday.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH FRIDAY/...
A shortwave trough over the Ohio Valley Tuesday evening will move
to the Mid-Atlantic coast by Wednesday morning. Surface low pressure
will take a similar track, however a broad area of high pressure
from the Great Lakes region to the Mid-Atlantic region will weaken
this approaching system. Warm air advection and frontogenesis on
the north side of the surface low will support rain and snow showers
across the northern Ohio Valley into western Pennsylvania, just
south of the forecast area. Light, scattered showers may brush the
western Southern Tier overnight, however probability is low.

High pressure will build into the eastern Great Lakes region
Wednesday and linger across the region through Thursday. This will
support dry and seasonable weather.

An area of low pressure will move across James Bay while it`s
associated cold front will swing through the Great Lakes region
Thursday night through Friday. Meanwhile, a southern stream system
will move from the Southern Plains to the Tennessee Valley. Warm air
and moisture advection head of the advancing cold front will support
rain showers ahead and with the frontal passage.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
The Mean 500mb pattern shows a trough moving across eastern Canada
Friday night into Saturday. Cold air advection and lingering
moisture on the backside of an exiting system may support rain and
snow showers across the eastern Great Lakes region through Saturday.
The mean mid-level pattern becomes zonal the end of the weekend into
next week, with no clear signals of forcing for precipitation. Due
to model spread and uncertainty, maintained low chances of showers
Saturday night into Monday.

Temperatures are expected to be below normal Saturday then lean
above normal Sunday and Monday.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
Deep low pressure over the the Canadian Maritimes will withdraw
northward across Labrador through Tuesday...while high pressure will
build east into our region from the Upper Great Lakes.

Northwesterly winds early this evening will slacken tonight...with
lingering lake snows southeast of the lakes and very light upslope
snow east of Lake Ontario also both generally tending to fade from
west to east. Some MVFR/IFR conditions could be found between KROC
and KFZY.

Outside of the lingering lake snows...expect general VFR conditions
to prevail across the lower elevations through tonight...with a mix
of MVFR/low VFR found across the higher terrain. Conditions will
then largely improve to VFR in most locations during Tuesday.

Outlook...

Tuesday night...VFR in most areas, with possible MVFR and spotty
light rain/snow showers across the Southern Tier.

Wednesday through Thursday...Mainly VFR.

Later Thursday night and Friday...VFR/MVFR with rain showers likely.

Saturday...VFR/MVFR with a chance of showers.

&&

.MARINE...
Deep low pressure over the the Canadian Maritimes will withdraw
northward across Labrador through Tuesday...while high pressure will
build east into our region from the Upper Great Lakes. This will
result in ongoing widespread Small Craft Advisory conditions
gradually diminishing from west to east tonight through Tuesday,
with much lighter winds then expected through the middle of the week.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Winter Weather Advisory until 10 AM EST Tuesday for NYZ004-005.
MARINE...Small Craft Advisory until 1 AM EST Tuesday for LEZ040-041.
         Small Craft Advisory until 7 AM EST Tuesday for
         LOZ042.
         Small Craft Advisory until 1 PM EST Tuesday for LOZ043>045.

&&

$$

SYNOPSIS...JJR/TMA
NEAR TERM...JJR/TMA
SHORT TERM...HSK
LONG TERM...HSK
AVIATION...JJR/TMA
MARINE...Hitchcock/JJR