253
FXUS61 KBUF 222354
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
654 PM EST Sat Feb 22 2025

.SYNOPSIS...
Expansive high pressure centered over the Ohio valley will push by
to our south tonight. A westerly flow in the wake of a cold front
will lead to renewed lake snows east of Lake Ontario later tonight
into Sunday. Meanwhile...high pressure to our south Sunday and
Monday will support a long awaited and welcomed warmup. In
fact...temperatures will climb to levels that we have not
experienced since last year...the last day of December to be exact.

&&

.NEAR TERM /THROUGH SUNDAY NIGHT/...
Our attention turns to the system to the west-northwest where
precipitation is currently being picked up on radars across southern
Ontario. Surface low pressure will move across James Bay early
tonight while a cold front approaches the area. Low-level winds will
veer to the west as moisture advection takes place across the
forecast area. A general light snowfall will move into the region
late tonight with some areas seeing just flurries. The main story
will be lake effect setting up east of Lake Ontario where moisture
is greater and the wind field aligns with the long fetch of Lake
Ontario. Snow will begin in Jefferson county late this evening and
settle across the Tug Hill late tonight into Sunday morning.
Snowfall amounts of 4 to 7 inches are expected on the Tug Hill and
western Adirondacks with 2 to 5 inches across Jefferson county. Snow
accumulation should taper off quickly to the south with less than a
inch south of the Oswego River. A Winter Weather Advisory is in
effect for Jefferson, Lewis, and Oswego counties beginning at 7PM. A
much weaker response will occur east of Lake Erie, due to ice cover,
warm air advection, and less moisture. A few elevated locations
across Erie, western Genesee, western Wyoming counties may see 1-2
inches late tonight through Sunday morning. Temperatures will fall
to the teens to low 20s tonight.

High pressure will nose into the forecast area Sunday. An upper
level trough will move east of the region by lunchtime. Warm air
advection will take over and continue through Sunday night. Any
lingering snow showers will come to an end across western NY Sunday
morning. A westerly flow and residual moisture will allow snow
showers to linger east of Lake Ontario through Sunday afternoon,
however snow showers should be fairly light. The Winter Weather
Advisory will come to an end by 1PM Sunday. High temperatures will
reach the low to mid 30s, upper 20s across the higher terrain.

Dry air will move into the region with continued warm air advection
aloft Sunday night. Lows will fall to the low to mid 20s.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
A shortwave that will move from the Upper Great Lakes to the Ottawa
valley will push a warm frontal boundary across our region during
the day Monday. Since the bulk of the associated isentropic lift
will stay north and east of Lake Ontario...mainly dry weather should
be found over the bulk of our forecast area. There will be the
chance for some rain showers over the Eastern Lake Ontario region
though.

More importantly...a 50kt low level jet Monday afternoon will
accompany the approaching mid level shortwave. While the bulk of
these winds will remain aloft within the warm advective pattern...
sfc gusts could reach close to 40 mph at times in the downslope
areas between KIAG and KROC. The winds will also advect notably
milder air into our region with H85 temps forecast to climb to
within a couple degrees of zero C. This will combine with a largely
southerly low level flow to encourage afternoon temperatures to
climb into the mid to upper 40s over the western counties...making
Monday the mildest day since the end of last year (Dec 31). The
widespread snow cover will certainly work against temps from over
achieving...but can certainly still see a few of the normally warmer
valleys tickling the 50 degree mark. Hello Dansville, Mount Morris
and even Wellsville.

In the wake of the mid level energy exiting across Quebec...a fast
moving shortwave ridge will scoot across the region Monday night.
This will support mainly dry weather across the western counties...
but by daybreak Tuesday...a more robust shortwave will be
approaching from the mid western states. While guidance differs on
the speed of this next feature...there should be at least the chance
for some mixed rain or wet snow showers as the night progresses.
Given that mins will be in the low-mid 30s...impactful accumulations
are NOT expected.

An upright mid level trough will become negatively tilted...as it
will cross our region on Tuesday. This should lead to fairly
widespread mixed rain and wet snow showers...although some guidance
packages are leaning towards a drier solution. Given the
`confidence` shown by the Superblend and NBM ensembles...have raised
POPs to likely to categorical throughout the region. Temps are
forecast to climb to within a few degrees of 40...so again...am NOT
expecting this to an impactful event.

Forcing and deeper moisture from the aforementioned shortwave will
exit across New England Tuesday night. This will prompt the mixed
pcpn to end from west to east with little if any accumulations of
wet snow. Temps again are forecast to only drop to the upper 20s to
lower 30s.

A broad low amplitude ridge will build across the Lower Great Lakes
on Wednesday. This will support mainly pcpn free weather with
temperatures that will remain above normal...within a few degrees of
40.

While confidence is growing for unsettled weather Wednesday night...
there is a range of solutions that will have to be considered. The
first being a clean frontal passage with a burst of mixed pcpn that
will end as snow showers...while the second is a wave that will pass
near or over the region with more widespread rain that will end as
wet snow. Have raised pops for this period...but can definitely see
them being raised notably higher in later packages.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
The persistent longwave trough over eastern Canada will evolve into
a deeper full latitude trough over the eastern half of the continent
during this period...and this will eventually lead to us returning
to temperatures that will average well below normal.

A vigorous shortwave will dive southwards from the Upper Mississippi
valley on Thursday...while energy from a previous storm system will
exit across New England. This will place our forecast area between
the two systems and should favor just scattered rain and snow
showers with no real impacts for our area.

A potent mid level trough will pass over the region Thursday night.
This will allow for some nuisance snow showers but nothing that
should have any real impact.

A broad ridge and associated axis of sfc high pressure will move
across the Lower Great Lakes on Friday. This should provide us with
a dry uneventful day with temperatures that will be in the low to
mid 30s.

A deep sub 995mb low will over the Upper Great Lakes Friday night
will move to the Ontario-Quebec border on Saturday. In the
process...a fairly strong cold front wil plow thorugh the region.
This will lead to more mixed rain and snow showers that will be
followed by a return to colder weather to end the weekend.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
A cold front will approach the region tonight and the combination of
moisture and a westerly flow will bring snow showers across the
forecast area. In particular, lake effect snow showers will target
the Tug Hill with accumulating snow. Ceilings will lower to low-end
VFR to MVFR across the region overnight through Sunday morning.
Visibility will fall in snow showers at KART late tonight through
Sunday morning. IFR/LIFR is possible at KART between 03-12z tonight.
A weaker response will be east of Lake Erie but snow showers may
briefly bring visibility down to less than 3SM at KBUF. Confidence
is low.

Snow will end across the region from west to east Sunday, however
flight conditions will mainly stay MVFR. Lake effect snow showers
will linger east of Lake Ontario, but south of KART through Sunday
afternoon.

Outlook...

Sunday...MVFR/IFR in lake effect snow east of the lakes in the
morning, improving to VFR/MVFR late.
Monday and Tuesday...VFR/MVFR. A chance of rain or snow showers.
Wednesday...Mainly VFR.
Thursday...VFR/MVFR. A chance of rain and snow showers.

&&

.MARINE...
High pressure continues to shift south of the region across the Ohio
Valley today, becoming centered over the southeast CONUS tonight. A
fresh southwesterly breeze around this area of high pressure will
result in SCA conditions through much of tonight.

Winds will begin to relax late tonight, though likely remain
elevated as a weak cold front moves through. Light to modest winds
then expected by Sunday evening, before offshore winds strengthen on
Monday.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Winter Weather Advisory until 1 PM EST Sunday for NYZ006>008.
MARINE...Small Craft Advisory until 10 PM EST this evening for LEZ020.
         Small Craft Advisory until 6 AM EST Sunday for LEZ040-041.
         Small Craft Advisory until 6 AM EST Sunday for LOZ042.
         Small Craft Advisory until 6 PM EST Sunday for LOZ043>045.

&&

$$

SYNOPSIS...RSH/TMA
NEAR TERM...HSK/TMA
SHORT TERM...RSH
LONG TERM...RSH
AVIATION...HSK/TMA
MARINE...PP/TMA