Amherst, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

556
FXUS61 KBUF 221400
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
900 AM EST Sat Feb 22 2025

.SYNOPSIS...
Expansive high pressure centered over the Ohio valley will push by
to our south today with just a few nuisance snow showers off Lake
Ontario. 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 TONIGHT/...
A large expanse of surface high pressure will extend from the
Mississippi Valley to the Carolina Coast across the southeast today,
with the sfc-700mb ridge axis moving from the Great Lakes to New
England. Despite weak warm advection aloft, 850H temps around -10C
and a weak passing shortwave are allowing flurries to continue off
Lake Ontario. This nuisance activity will move north to the St.
Lawrence Valley through much of the day. A lack of moisture in the
DGZ should keep any accumulations minimal.

Further south, outside of a stray flurry or two expect a fairly
quiet and snow-free day albeit with some patchy cloud cover.
Temperatures this afternoon will warm to the upper 20s to low 30s,
accompanied by a stiff southwest breeze. Gusts to 35mph will be
possible across the Niagara Frontier and up near the St. Lawrence.

Attention tonight will shift to the next incoming shortwave trough
which will descend southeast across Ontario Province and into the
Great Lakes. This feature will send a weak cold front and plume of
synoptic moisture across the lakes which will reinvigorate the lake
response and bring renewed chances for snow.

Off Lake Ontario...The long west-southwesterly fetch over the lake
should initially direct weak lake enhanced snows across Jefferson
County and the Watertown Metro late in the evening. The primary band
of snow should then quickly settle southward to the Tug Hill
Plateau, where it will remain through the rest of the night. A much
more favorable setup expected compared to Erie given the colder
temperature and deeper moisture profiles, in addition to the lack of
ice on the waters. While the capping inversion will remain below
5kft, a deep and saturated saturated DGZ should allow for decent
fluffy snow accumulations. These will be maximized over the Tug
where 3-5" could fall by daybreak Sunday. For this reason have gone
ahead and hoisted a Winter Weather Advisory for Oswego/
Lewis/Jefferson counties.

Off Lake Erie...As alluded to previously, not nearly as favorable of
a setup over the almost entirely ice-covered lake expected tonight.
DGZ moisture here looks to be overall shallower and shorter lived,
with greater shear and a capping inversion under 2.5kft. Still, weak
synoptic forcing with the limited enhancement from the lake will
produce scattered snow showers, mainly west of the Genesee Valley.
Accumulations of an inch or less expected by Sunday morning in this
area.

Otherwise, temperatures tonight will dip back into the upper teens
to low/mid 20s.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As we begin Sunday morning a lake response will still be ongoing
east of both lakes. Off Lake Erie this will be weaker thanks to the
mostly ice covered lake and lake-induced EQLs of only 3 kft...both
of which should help to keep the activity confined to scattered snow
showers and additional accumulations of under a half inch. Meanwhile
over Lake Ontario lake EQLs will range from 5-6 kft...and this
coupled with better/deeper moisture...a fetch along the long axis of
the lake...and orographic lift will result in a better organized
band of light to moderate snow directed at the Tug Hill region...
where additional accumulations of 2-3 inches will be likely through
the first half of the day. Coupled with the accumulations expected
tonight...this has prompted the issuance of a Winter Weather
Advisory for the Tug Hill region from tonight through 1 PM Sunday.

As we push through later Sunday morning and afternoon...the lake
response will fade from west to east as late February diurnal
influences come into play and another flat low-level ridge crosses
the Lower Great Lakes. This will take place first off Lake Erie
later Sunday morning...then Lake Ontario Sunday afternoon...with any
remnant snow showers east of Lake Ontario eventually getting
absorbed into a weak warm frontal zone lifting across southern
Ontario and Quebec Sunday night. Outside of the lake effect
areas...Sunday and Sunday night will feature dry and uneventful
weather...with temperatures continuing on a modest upward arc.
Expect highs on Sunday to mostly run in the lower to mid 30s...with
a few of our warm spots in the Genesee Valley/western Finger Lakes
possibly even reaching the upper 30s. Lows Sunday night will then
range through the 20s.

On Monday surface-based ridging will slide off the Atlantic
coastline and out to sea...while a compact mid-level trough and
associated wave of low pressure moves from north-central Ontario
Province to James Bay. The deepening/strengthening south to south-
southwesterly low level flow in between these features will help to
pump increasingly milder air into our region as we push through the
day...with consensus 925 mb temps climbing to between -1C and +3C by
early to mid afternoon. With the aforementioned strengthening S-SSW
low level flow providing good mixing (particularly across far WNY
where gusts to 35-40 mph are anticipated)...this will result in
temps surging into the upper 30s and lower 40s east of Lake Ontario
and to the mid and upper 40s across much of western New York...with
areas of favored downslope flow seeing additional compressional
warming/ drying and an additional boost to temperatures. Should some
of the warmer guidance verify...it`s not out of the question that a
few spots (namely Dunkirk and Dansville) could make a run at the 50
degree mark. Meanwhile the ongoing warm advection pattern and
passing shortwave energy aloft will help to generate some scattered
light pcpn... particularly during the afternoon hours as another
warm frontal segment crosses the northern half of the area. Given
the above timing and the ongoing warming...the bulk of these should
merely fall in the form of plain rain showers...with any potential
for snow showers confined to Monday morning.

Monday night the initial mid-level trough and surface low will make
their way across Quebec Province...while another compact shortwave
trough dives across the Great Lakes and begins impinging upon our
area later in the night. With a mild south to southwest flow
remaining in place out ahead of this latter feature...nighttime lows
will range from the lower to mid 30s east of Lake Ontario to the mid
and upper 30s elsewhere...with resulting thermal profiles helping to
keep any showers predominantly in the form of plain rain.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Through midweek broad/flat upper-level troughing will remain in
place across our region...with a veritable parade of embedded
shortwave troughs and associated surface waves rotating through this
larger-scale trough and crossing our region in the process. This
will provide us with periodic opportunities for some light to modest
precipitation...along with corresponding shots of warm air advection
that will result in continued above normal temperatures in spite of
the larger-scale troughing that will be in place. These will allow
daytime highs Tuesday through Thursday to range between the upper
30s and mid 40s...with lows in the upper 20s-lower 30s Tuesday and
Wednesday nights. The corresponding warmer temperature profiles
should also allow any precip from these systems to largely be/change
over to plain rain in many areas each day...then back to a rain/snow
mix or just plain snow at night.

Late in the period the last of the shortwave impulses still looks to
partially phase with a deeper northern stream trough digging
southeastward across eastern Canada...though the degree of this
phasing has lessened in the latest suite of medium range guidance
over the past 24 hours. Consequently...this results in a weaker
surface low passing by to our southeast later in the week...followed
by a slower/weakened return of colder air toward the end of the
period. With this in mind have only brought temps down to just a
little below average by the end of the work week...with scattered
rain and snow showers changing back to snow and diminishing over
time as surface-based ridging and drier air builds in behind the
departing surface low Thursday night and Friday.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
MVFR cigs/vsbys in weak lake effect will likely linger northeast of
Lake Ontario through much of the day, with just some patchy low
cloud cover and scattered flurries south of the lake this morning.
Otherwise, VFR weather will prevail through the day. Breezy
southwest winds around an area of high pressure to the south will
support gusts 30-35 kts at KBUF and KIAG.

Winds will relax some heading into this evening as cloud cover
begins to thicken to low VFR/MVFR across the region ahead of an
approaching cold front. This front will lead to increased chances
for lake snows east and northeast of both lakes through tonight,
mainly after 03z. Localized MVFR/IFR vsbys will be possible at KIAG
and KBUF, and are likely at KART. The lake effect east of Lake
Ontario is expected to strengthen as it moves south of KART later
in the night with localized LIFR vsbys.

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.

&&

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

Winds will begin to relax overnight 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 from 7 PM this evening to 1 PM EST
     Sunday for NYZ006>008.
MARINE...Small Craft Advisory until 7 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
NEAR TERM...PP
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...PP
MARINE...PP