773
FXUS61 KBUF 221807
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
107 PM EST Fri Nov 22 2024

.SYNOPSIS...
Low pressure will continue to spin over the Northeast US
through tonight, producing low elevation rain and high elevation
wet snow across the region. A few leftover rain and wet snow
showers will continue Saturday through early Sunday before high
pressure builds in and brings a return to dry weather by late
Sunday.

&&

.NEAR TERM /THROUGH SATURDAY/...
Stacked low pressure across eastern New York this afternoon will
take a circular track across southern New England tonight
before exiting across the Gulf of Maine on Saturday. This will
maintain a moist cyclonic flow aloft during the period and a
risk for periodic precipitation. Large scale lift associated
with the warm conveyor of the cyclone will weaken as it moves
from east to west across the area this afternoon. By late
evening this feature will weaken and move to our south, bringing
an end to the steadier precipitation. Expect a lull in
precipitation for most areas late tonight, then an increasing
northwesterly flow Saturday will result in some upslope and/or
lake enhanced precipitation. By this time, the moisture is
shallow and likely not deep enough to reach into the DGZ. As a
result, suspect model QPF is too high Saturday afternoon with
some showers and patchy drizzle expected.

Precipitation type will continue to be heavily dependent on
elevation. The region has moved into a warmer sector of the
storm with 850mb temps around -3C. This combined with daytime
heating has raised snow levels to the highest terrain, roughly
over 1700 feet. Through this evening, could see up to 2 inches
of additional wet snow accumulation across higher terrain with
all rain across lower elevations. Some higher elevation snows
can`t be ruled out late tonight into Saturday morning, then
after that slight warming and low cloud tops should result in
all rain.

It will be quite windy along the lakeshores this afternoon
through this evening, with north winds gusting in the 30-40 mph
range close to the lakes.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
Cool NW flow will continue to support some measure of
lake/upslope precipitation Saturday night behind the departed
mid-level low. A shortwave dropping southeast through this NW
flow is advertised to bring a re-enforcing shot of colder air
overnight nudging H850 T`s down to -5C/-7C as we move into
Sunday. While this normally would help or support lake
effect...drier air working in at the mid-levels will limit its
potential. Therefore...have lowered POPs and added drizzle given
the lack of moisture extending through the DGZ. Lingering
precipitation Sunday morning will then begin to dissipate and
drier conditions will take hold by late in the afternoon. After
that...weak high pressure takes over and mid-levels begin to
warm rapidly Sunday night.

Monday...it looks like it will remain dry for much of the day and
mild ahead of an area of low pressure taking shape over the Mid-
Mississippi Valley. Monday night...given that guidance shows the low
passing to our west across Michigan this will keep the eastern Great
Lakes firmly in the warm-sector. No p-type concerns at the
moment with precipitation all in the liquid form.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
It will become windy and cooler by Tuesday in the wake of the
passing surface low. Consensus 850mb temperatures drop down to
around -8C by late Tuesday night, with a fairly moist cyclonic
flow aloft. This will support some lake effect precipitation,
with it cold enough for some of this to be snow. Westerly winds
will direct most of the lake effect and upslope enhanced
precipitation across the typical snow belts east of the lakes
Tuesday night and Wednesday. Accumulating snows are likely, with
advisory level amounts (greater than 4 inches) possible but far
from a certainty. Due to the marginally cold air mass, greater
accumulations would be more likely across higher terrain such as
the Chautauqua Ridge and Tug Hill.

A more zonal flow aloft develops by Thursday, with some models
developing a wave of low pressure and tracking it to our south. This
possible system in addition to lingering lake effect may produce
some rain or snow showers.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Widespread rain across lower elevations and rain/snow mix across
higher terrain this afternoon, although the area of steadiest
rains will move from west to east across the area. Lots of low
moisture resulting in MVFR/IFR cigs across the area. Higher
confidence in IFR across higher terrain, but expect periods of
IFR across lower terrain during the day today also. Rain and fog
will also result in visibilities of 2 to 3SM at times. It will
also be quite windy today with northerly gusts 25 to 30 knots
at times.

Tonight, the widespread precipitation will be replaced by scattered
rain and snow showers in northerly upslope flow with some
contribution from limited lake effect. CIGS should improve somewhat
across lower elevations, with mainly MVFR for lower elevations and
IFR for higher terrain.

On Saturday some rain (and possibly wet snow) will increase
somewhat during the day. By the afternoon expect cloud tops
below the DGZ which may result in drizzle. Expect mainly MVFR
cigs with areas of IFR and also some vsby restrictions possible.

Outlook...

Saturday night...VFR/MVFR with rain or wet snow showers across
higher terrain.

Sunday...VFR/MVFR with a chance of a rain or snow shower.

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

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

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

&&

.MARINE...
A moderately deep surface low will loop from southeast NY across
southern New England through this evening. This will support
Small Craft headlines on most of the waters as outlined below.

Winds will gradually diminish later tonight with Small craft
Advisory conditions coming to an end. The lull in winds will not
last long, with increasing northwest winds Saturday bringing another
round of Small Craft Advisory conditions to both lakes.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory until 1 AM EST Saturday for LEZ040-041.
         Small Craft Advisory until 1 AM EST Saturday for
         LOZ030-045.
         Small Craft Advisory until 4 AM EST Saturday for
         LOZ042>044.
         Small Craft Advisory until 4 PM EST this afternoon
         for SLZ022-024.

&&

$$

SYNOPSIS...Apffel/Hitchcock
NEAR TERM...Apffel
SHORT TERM...Reynolds
LONG TERM...Apffel/TMA
AVIATION...Apffel
MARINE...Apffel/Hitchcock