Buffalo, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

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FXUS61 KBUF 240919
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
419 AM EST Sun Nov 24 2024

.SYNOPSIS...
Lingering lake effect clouds and showers southeast of the lakes
today as seasonably cold air continues to flow into the region. High
pressure will provide a brief period of dry weather tonight into
Monday before low pressure brings widespread rain to the region
Monday night into Tuesday. Colder air behind this system will
maintain chances for rain and snow showers downwind of the lakes.
Another low pressure system will pass south of the area on
Thanksgiving with increased chances for rain and snow. The airmass
behind this late week system will be much colder in comparison, with
higher potential for lake effect snow through the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
A pair of mid-level shortwaves sliding southeastward out of Ontario
will round the base of a stacked low pressure system over the
Canadian Maritimes today. This will maintain a seasonably cold WNW
flow across the region with sfc temperatures near normal for late
November. Temps aloft at 850H on either side of -5C will support a
lake response with a wealth of clouds and some measure of shower
activity southeast of the lakes through the day. While weak upstream
connections to Lake Huron/Georgian Bay could lead to more defined
bands of showers at times, the lake response will become
increasingly muted through the day given the lack of mid-level
moisture and building high pressure to the west. There could be a
few wet flakes across the hilltops especially this morning, though
little to no accumulations are expected.

Outside of a stray shower or two early on, dry weather expected
tonight as the sfc-850H ridge moves directly overhead. Lake induced
cloud cover should become increasingly scattered, though mid and
high clouds will begin to thicken from the west as a weak warm front
lifts northward into the area. Can`t rule out the possibility of
some patchy fog formation depending on the amount of clearing
overnight, particularly in the Southern Tier valleys. Temps tonight
will range from the upper 30s along the Lake Erie shoreline to the
low 20s across Lewis County, with mainly low/mid 30s elsewhere.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
High pressure across the region early Monday will slide east, while
low pressure system lifts across the Great Lakes in response to an
upper wave moving in from the upper Midwest. Precipitation will
increase as we move through the afternoon as this system approaches
from the west. Precipitation type will not be an issue as
temperatures warm well into the 40s with even some lower 50s
ensuring an all rain scenario.

Rain showers will become widespread Monday night into Tuesday as the
low pressure system deepens and tracks just to the north of our
area, with the system cold front approaching from the west. Bulk of
the ensemble rainfall amounts on the order of a quarter to a half
inch. Following the passage of the cold front, strong cold advection
will send temperatures falling during the day Tuesday with windy
conditions developing. A westerly upslope flow will support some
mixed rain and wet snow showers across the higher terrain east of
both lakes.

A west-northwest flow regime will be in place Tuesday night and
Wednesday. Most guidance suggests 850 mb temperatures will fall to
near -7C keeping the potential for lake effect snow and rain showers
going east and east-southeast of both lakes, though dry air
advection should cause the activity to gradually weaken from west to
east Wednesday. There looks to be the potential for a few to several
inch of snow accumulation on the higher terrain east of Lake Ontario
where available moisture will be deeper/persist longer.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
This looks to be a potentially active period. The three main
operational models agree there should be cyclogenesis in the
southern Plains by Wednesday, but differ in the low track moving
into Thanksgiving Day. The 00Z GFS and CMC fairly similar in a track
that is father south of the area over the Tennessee Valley and the
northern Mid-Atlantic by Thursday and to near Cape Cod Friday
morning, with the ECMWF farther to the north. This difference in
storm tracks makes for a tricky mid week/holiday forecast. The
more northern track would bring a risk for mixed precipitation
into the region with the potential for some accumulating snow
(more likely across higher terrain), while the southern track
would keep the bulk of the precipitation shield south of the
region. At this stage of the forecast will play the middle
ground and hedge a bit more toward a northern solution which is
closer to continuity, but confidence in this is low.

Perhaps more concerning will be a surge of arctic air which will
spread into the region behind this system Friday and into the
weekend. This airmass will likely support accumulating lake effect
snow downwind of the lakes, with the potential for localized
significant amounts certainly in play. Much too far out to pinpoint
focus locations or amounts, but this time period will need to be
monitored closely.

&&

.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
A mid-level trough passing to the north will continue to funnel a
seasonably cold albeit dry airmass over the lakes through Sunday.
This will support lake effect clouds in addition to light rain/snow
showers, with some patchy drizzle. Cigs are expected to be a mix of
low VFR and MVFR, while shower activity remains focused southeast of
the lakes, mainly south of KBUF and northeast of KROC between KSDC
and KFZY. Showers/drizzle could lead to periods of MVFR vsbys. Any
wet snow will be confined to the higher elevations east of the lakes.

The lake response will wane through the course of the day Sunday as
surface high pressure continues to build into the region from the
west. Shower coverage will gradually diminish as a result as cigs
improve to mainly VFR, with dry weather expected areawide by the end
of the 06z TAF cycle.

Outlook...

Sunday night...Mainly VFR with MVFR cigs lingering in the Southern
Tier.

Monday...VFR/MVFR with a chance of rain during the afternoon and
evening.

Tuesday...MVFR with rain and snow showers likely.

Wednesday and Thursday...VFR/MVFR with a chance of rain or snow
showers.

&&

.MARINE...
A large low pressure system over the Canadian Maritimes will slowly
weaken and drift east into the Atlantic Monday. A relatively steep
pressure gradient between this system and a building ridge of high
pressure to the west will continue to support a stiff WNW breeze
and SCAs on the lakes through much of today.

Winds and waves will begin to diminish from west to east later this
afternoon as the high further builds into the region. SCAs will
first drop on Lake Erie, followed by the west end of Lake Ontario.
The SCAs on the central and eastern zones have been extended by 6
hours this update.

After a period of gentle to modest breezes and generally offshore
wave action, the next low pressure system will move directly over
the eastern Great Lakes Monday night into Tuesday. This will drive a
cold front through the region, with fresh to strong southwesterly
winds likely into Wednesday.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory until 4 PM EST this afternoon for LEZ040-
         041.
         Small Craft Advisory until 7 PM EST this evening for
         LOZ042.
         Small Craft Advisory until 1 AM EST Monday for LOZ043>045.

&&

$$

SYNOPSIS...PP
NEAR TERM...PP
SHORT TERM...TMA
LONG TERM...TMA
AVIATION...PP
MARINE...PP