WX in text

384
FXUS61 KBUF 301229
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
729 AM EST Mon Dec 30 2024

.SYNOPSIS...
Low pressure will pass by to the northwest of the region today,
bringing some rain showers along with strong, gusty winds northeast
of Lake Erie and Lake Ontario. Another area of low pressure will
move out of the Ohio Valley on Tuesday and bring another period of
rain Tuesday afternoon through New Years Eve. New Years Day will
usher in a prolonged stretch of cold, wintry weather that will
persist for the foreseeable future.

&&

.NEAR TERM /THROUGH TONIGHT/...
It will be very windy across the region today...especially this
morning over the far western counties. A deep 988mb low north of
Georgian Bay at daybreak will continue to move away from the
region...but a 50-55kt low level jet will combine with significant
isallobaric pressure rises and funnelling up the length of Lake Erie
to generate damaging winds across parts of the IAG Frontier along
with Chautauqua and srn Erie counties. As of 730 AM...winds have
already gusted to 63 mph at the BUF airport. While the corresponding
high wind warning will be in effect until 4 PM...the absolute
strongest winds will be experienced through mid morning. After that
time...the aforementioned strong low level jet will pull away and
the isallobaric pressure rises will ease. Winds across much of the
rest of western and north central New York will have the potential
to gust to 40 mph.

Otherwise, there`s good model agreement that rain showers will move
through today along the trough axis and aided by upsloping east of
the lakes. The system will usher in a cooler air mass with 850mb
temps dropping to -4C. The rain will mix with some wet snow across
higher terrain, but there will be little or no accumulation during
the day.

The surface low will exit to the north across Quebec tonight, while
a shortwave ridge will build across the Lower Great Lakes. This will
encourage a short period of fair dry weather to return, although
there will be some residual rain and wet snow showers east of Lake
Ontario. A slushy inch or two is possible on the Tug Hill.
Otherwise, winds will drop off quickly across Western New York
tonight, and eventually east of Lake Ontario as the surface low
moves further away.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
***PROLONGED ACCUMULATING LAKE EFFECT SNOWS POSSIBLE BEGINNING AS
EARLY AS WEDNESDAY AND THEN LASTING POTENTIALLY INTO THE WEEKEND***

Unsettle weather will continue through this entire period. Surface
low pressure over the mid-Mississippi Valley will head into the Ohio
Valley on Tuesday. The parent sfc low will begin to weaken as it
nears the western Lake Erie Basin late Tuesday afternoon/evening,
then transfer its energy over to a developing secondary sfc low near
New Jersey/Long Island. As the parent low nears, we should see an
area of light precipitation, mainly all `rain`, work from southwest
to northeast through the region. It will `not` be until very late
Tuesday night or early Wednesday morning that colder air begins to
wrap back in across the region. Only then...will we see a transition
over to `snow`, first over the higher terrain and then everywhere by
Wednesday afternoon. As winds back from northwest to westerly
Wednesday, favored upslope areas will see the greatest potential for
accumulating snowfall. Additionally...a strengthening wind field
aloft (+40 knots @ 925mb) and decent lapse rates will `likely` bring
gusty winds up to 35mph in the afternoon and into the evening.

Ongoing CAA Wednesday night will send 850mb T`s down to -10C/-11C
across the Lower Lakes. We should also see a pure lake effect regime
start to become established east and southeast of both lakes through
Thursday night. Lake effect snow will then continue all day Thursday
and the remainder of the work week, possibly even longer (weekend).
We will also see upstream connections become established helping to
boost organized lake bands, especially off lake Ontario. At this
juncture...given model consistency and favorable lake parameters (EQ-
levels +8K, deep moisture through the DGZ, and uniform flow),
confident enough to issue a Winter Storm Watch for the potential of
7 inches or more off both lakes. For Lake Erie...the Watch will
begin 12Z Wednesday and include the following counties S. Erie,
Wyoming, Chautauqua, and Cattaraugus. Off Lake Ontario...the Winter
Storm Watch will be for Wayne, N. Cayuga, Oswego, Jefferson, and
Lewis beginning 18Z Wednesday. That said...still confident that lake
snows will stay focus south of the Buffalo Metro area off Lake Erie.
Off Lake Ontario...lake snows will mainly focus over the Tug Hill
and theses counties, Oswego, N. Cayuga, and Wayne.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
Large scale troughing is expected over much of the eastern CONUS,
and especially across the Great Lakes region. While the large scale
pattern is not an anomalously low mid-level trough, this pattern
looks to be sticking around at least into the second week of January
with below normal temperatures and the return of wintry
precipitation. Northwesterly flow aloft will continue to bring 850mb
temps 5-10C degrees below normal for early January.. Latest GEFS has
little model spread in 850mb temps mainly ranging from -12 to -16C
Friday through next weekend. Forecast highs will be in the 20s for
Friday through Sunday across western and north-central NY.

However, with these colder temperatures aloft, the main forecast
concern through the long term will be a prolonged period of lake
effect snowfall through the weekend. As the midweek coastal low
lifting north kicks off the upper level pattern we will see through
the remainder of the week, westerly to northwesterly flow over the
lakes will support lake effect snowfall. Latest GFS forecast
soundings off Lakes Erie and Ontario continue to show colder
temperatures aloft supporting lake induced EQLs in the neighborhood
of 6-8 kft. 925-700mb directional shear is minimal through Thursday
night, but then increasing forecast uncertainty arises among the
modeling systems for Friday into Saturday with minor fluctuations in
wind directions. GEFS, EC, and CMCE all have minor differences with
the timing of a secondary 500mb trough axis Friday that would
increase low-level directional shear and turn flow more
northwesterly, disorganizing and weakening lake effect snowfall.
Nearly half of the CMCE members are slower with this trough keeping
850mb winds out of 250-260 for 6-12 hours longer through Friday
night. After the passage of this trough axis, northwest flow looks
likely for the remainder of the event where multiband lake effect
snow may continue into late Sunday.

&&

.AVIATION /13Z MONDAY THROUGH FRIDAY/...
An area of showers will move into Western NY and eventually
eastward across the rest of the area today. With this, cigs
will also lower back to MVFR/IFR. Rain showers will not be heavy
enough to produce prolonged vsby restrictions but they will mix
with snow across higher terrain where vsby of 2SM or less is
possible at times.

Another impact to aviation will be strong winds which will develop
across Western NY this morning. Peak gusts of 40-50 knots can be
expected to last for a few hours, and then will trend down this
afternoon. Winds will then drop off more abruptly this evening and
tonight. Cigs will gradually lift to VFR/MVFR tonight as a shortwave
ridge builds in.

Later tonight, winds will drop off more. There will be some
lingering cloud cover although bases will mainly be in the VFR
flight category with patchy IFR/MVFR across higher terrain.

Outlook...
Tuesday...Rain returns Tuesday afternoon with VFR conditions
deteriorating to MVFR/IFR.

Tuesday night and Wednesday. Mainly IFR conditions in rain. Rain
will change to wet snow from west to east Wednesday.

Thursday and Friday...LIFR in bands of lake effect snow east of
the lakes, otherwise MVFR/VFR with scattered light snow showers.

&&

.MARINE...
A deepening surface low will track into the central Great Lakes
today. Gales will continue on Lake Erie as the low passes by
this morning, with strong winds spreading across Lake Ontario
during the day. Winds won`t be quite as strong on Lake Ontario
since it will be further from the surface low, but still
expecting a few hours of low end gales on the lake. Surface
temperatures will only be in the upper 30s to lower 40s, so
winds aloft will not mix completely with similar lake
temperatures. Even so, a 50 knot LLJ supports the gales in
place. Expect winds to be less (just below gale) along the
central south shores of Lake Ontario. Winds will drop off
tonight, but expect a period of small craft advisories will be
needed after the gales drop off.

A strong low pressure system will pass by to our south producing
another period of strong winds on the lakes. This will support small
craft and/or gale headlines on the lakes Wednesday and Thursday.

&&

.TIDES/COASTAL FLOODING...
Winds will increase abruptly early this morning as low pressure
passes by to the west tonight. Southwest winds will reach gale
force on Lake Erie, which will result in rises in water levels.
At this time rises to about 8 feet are likely, which may cause
splashover issues along the immediate lakeshore. This includes
Route 5 near Hamburg, and may impact portions of the Buffalo
Harbor and Canalside. Expect levels to rise quickly through 10
a.m. this morning as winds shift from the SSW to the SW and
increase with a frontal passage.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...High Wind Warning until 4 PM EST this afternoon for NYZ001-002-
     010-011-019-085.
     Wind Advisory until 4 PM EST this afternoon for NYZ003-012-020.
     Winter Storm Watch from Wednesday afternoon through Sunday
     afternoon for NYZ004>008.
     Wind Advisory until 7 PM EST this evening for NYZ007.
     Lakeshore Flood Warning until 1 PM EST this afternoon for
     NYZ010-019-085.
     Winter Storm Watch from Wednesday morning through Sunday
     afternoon for NYZ012-019-020-085.
MARINE...Gale Warning until 7 PM EST this evening for LEZ020-040-041.
         Gale Warning until 7 PM EST this evening for LOZ030-
         042-062.
         Small Craft Advisory until 1 PM EST Tuesday for LOZ043-044.
         Gale Warning until 10 PM EST this evening for LOZ045-
         063>065.
         Small Craft Advisory from 1 PM this afternoon to 1 AM
         EST Tuesday for SLZ022-024.

&&

$$

SYNOPSIS...Apffel
NEAR TERM...Apffel/RSH
SHORT TERM...AR
LONG TERM...AR/Brothers
AVIATION...Apffel
MARINE...Apffel
TIDES/COASTAL FLOODING...Apffel

NWS BUF Office Area Forecast Discussion