FXUS61 KBUF 111755
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1255 PM EST Mon Dec 11 2023

.SYNOPSIS...
Narrow bands of lake effect rain and snow will continue east of
Lake Erie and Lake Ontario this afternoon. Light accumulating
snow will mainly stay confined to the higher terrain. Lake
effect bands will move north and weaken tonight. A cold front
will approach the region Tuesday and bring breezy conditions
especially northeast of the Lakes. Lake effect snow will develop
Tuesday night through Wednesday.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Multiple, narrow bands of lake effect rain and snow showers
have developed east-southeast of the Lakes this afternoon. Most
of the area is above freezing with the exception of the higher
terrain.

Area webcams and surface observations display mainly snow on
the higher elevations east of Lake Ontario, while lower
elevations remain a mix of rain and snow. As the mid level
trough axis passes across the region today precipitation will
become all snow with the deepening cold air, however at this
time the better lift will be exiting to our east, with just
upslope flow lingering snow east of Lake Ontario through the
afternoon. A Winter Weather Advisory will remain in place here.

Lake Effect Snow...Meanwhile the colder air is generating a weak
lake effect response. This activity, becoming all snow will be minor
through the daylight hours downwind of the eastern Great Lakes on a
west to northwest flow of shallow moisture. There may be a
brief uptick and organization after sunset tonight in the lake
effect snow band. Surface high pressure will press towards our
region tonight, backing the surface winds while also supplying
additional dryness in the lower and mid levels. This will weaken
the lake bands as they lift northward, with increased wind
shear late tonight all but ending any lingering lake bands of
snow. An inch or two of snow southeast of the Lakes with perhaps
a half inch of snow near Buffalo and Watertown as the lake
snows lift northward and weaken tonight. Any snow in Buffalo
would like all fall just after midnight and before the morning
commute tomorrow, though east of Lake Ontario some snow may
still be falling near Watertown as the morning commute
commences.

Winds...West-northwest winds will increase to 15 to 25 mph with
gusts up to 35 mph today. The higher gusts will be along the
southern shore and inland of Lake Ontario through the afternoon
hours.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Tuesday will be a windy day, especially across the Niagara Frontier.
925mb winds increase to 40 kts and become well aligned with surface
winds across the Niagara Frontier mid-day Tuesday. This combined
with clearing skies suggests fairly good mixing, supporting the
potential for wind gusts approaching 50 mph possible. Not as windy
elsewhere where winds aloft will be weaker, but gusts 35 to 40 mph
are possible. Otherwise it will be a warmer day with highs in the
upper 30s to lower 40s. Some lingering lake enhanced snow showers
possible east of Lake Ontario Tuesday morning.

After this, our attention turns to the potential for lake effect
snow east of Lake Ontario. A short but favorable window for lake
effect snow opens up Tuesday night and Wednesday. A mid-level trough
will dig across New England, providing deeper moisture and dropping
850mb temps to -13C across Lake Ontario. Southwesterly flow will
gradually shift to the northwest, with the westerly winds during
this transition having the best chance to produce heavy snow due to
the long fetch and the potential for a Georgian Bay connection. As
is typical, the RGEM is by far most aggressive with this, and likely
has the best handle on band location. However other high res model
guidance has MUCH less QPF. Forecast will weight the RGEM, but with
virtually no support from other guidance do not have the confidence
to issue a watch at this time. However, this does appear likely to
produce advisory snows of 4 to 7 inches on the Tug Hill with a small
chance of localized warning amounts if the RGEM fully verifies.
Shorter fetch and the lack of an upstream connection will limit
accumulations off of Lake Erie. Outside of this, there will be
scattered snow showers Tuesday night/Wednesday, but little if any
accumulation outside of the lake effect areas. Wednesday will be a
fairly blustery day with highs in the lower 30s and winds gusting to
30 mph.

Winds will be northwest by late Wednesday, leading to more
disorganized lake effect snows southeast of Lake Ontario. This could
result in 1 to 3 inches of snow from Monroe to Cayuga counties until
winds diminish and temps aloft warm by late Wednesday night.
Diminishing winds will allow for limited radiational cooling with
lows ranging from the teens east of Lake Ontario to the lower to mid
20s elsewhere.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
The long term period will feature mainly dry weather with
temperatures averaging above normal. High pressure centered across
the Appalachians will maintain mostly sunny skies and breezy
southwesterly winds for Thursday and Friday. A moisture starved mid-
level trough will track to our north across eastern Canada Friday
night through Saturday night. This will bring a very small chance of
rain/snow showers east of Lake Ontario, but otherwise the dry
weather pattern will hold through the weekend. Thursday will be
cooler with highs in the 30s, but after that highs will be in the
40s through the weekend.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
Narrow bands of lake effect rain and snow bands will continue east
of Lake Erie and Lake Ontario this afternoon. A period of localized
moderate snow is possible within a snow band and may result in LIFR
conditions. This is the case for KJHW through the afternoon. Rain
and snow are more widespread east of Lake Ontario. Light snow is
possible at KART. Elsewhere, light snow is possible in widely
scattered bands but probability is low. Mainly MVFR/IFR conditions
at lower elevations (KIAG, KBUF, KROC) through this evening.

Lake effect bands will weaken while moving north tonight. Light snow
may move into KBUF/KIAG and KART late tonight and result in a period
of light snow and reduced flight conditions. It will be short-lived.
Winds increase across the region Tuesday morning. Strongest winds
will be northeast of the Lakes by Tuesday afternoon.

Outlook...

Tuesday...Mainly VFR. Breezy.

Tuesday night through Wednesday...Areas of MVFR/local IFR with lake
effect snow showers, mainly east of Lake Ontario.

Thursday and Saturday...VFR.

&&

.MARINE...
Westerly winds will continue to produce higher end Small Craft
Advisory conditions on Lake Erie and Lake Ontario. West winds will
become southwest and increase on Tuesday ahead of a cold front on
both Lake Erie and Ontario through the day. There may be a period of
frequent Gale force gusts Tuesday into Tuesday evening. Winds
diminish but continue to produce small craft conditions
through Wednesday night.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Wind Advisory from 7 AM to 6 PM EST Tuesday for NYZ001-002-010-
     011.
     Winter Weather Advisory until 7 PM EST this evening for
     NYZ006>008.
     Winter Storm Watch from Tuesday evening through Wednesday
     afternoon for NYZ006-008.
MARINE...Small Craft Advisory until 1 AM EST Thursday for LEZ040-041.
         Small Craft Advisory until 1 AM EST Thursday for
         LOZ042.
         Small Craft Advisory until 1 AM EST Tuesday for LOZ030.
         Small Craft Advisory until 7 AM EST Thursday for
         LOZ043>045.

&&

$$

SYNOPSIS...HSK
NEAR TERM...HSK/Thomas
SHORT TERM...Apffel
LONG TERM...Apffel
AVIATION...HSK
MARINE...HSK/Thomas