Forecast Discussion

Forecast Discussion for BUF NWS Office
FXUS61 KBUF 042129

Area Forecast Discussion
National Weather Service Buffalo NY
429 PM EST Sun Dec 4 2022

Lake effect snow showers will persist through this evening northeast
of Lake Ontario with spotty minor accumulations. Otherwise, the rest
of the area will be dry tonight through Monday as high pressure
builds east from the Ohio Valley to the Mid Atlantic. A weak trough
will then move into the eastern Great Lakes late Monday night and
linger through midweek, producing a wealth of clouds and a few
periods of light rain.


Radar imagery currently showing very little in the way of any
activity coming in off the Lakes. Boundary layer flow will
continue to back to the southwest through the early evening,
with a few light snow showers possibly redeveloping across
Jefferson County.

A weak trough will pass through the Saint Lawrence Valley this
evening. The associated uptick in synoptic scale moisture and low
level convergence will likely allow for a brief increase in lake
effect snow showers over Jefferson County for a few hours this
evening as mentioned above. Any accumulation will be very light,
less than an inch in a few spots. Lake effect will end overnight as
ongoing warm advection drops inversion heights to under 5K feet
after midnight.

Otherwise, the rest of the area will be dry through tonight. A plume
of lake effect clouds off Lake Erie will continue to bring locally
cloudy skies to far northern Erie, Niagara and Orleans counties
through early evening. It will remain quite breezy tonight northeast
of Lake Erie and Lake Ontario, with gusts at times in the 25-30 mph
range. Lows tonight will range through the 20s across much of the
area, bounded by some upper teens across the Tug Hill and western
Dacks with some very low 30s near the lakeshores.

Monday will be dry as surface high pressure drifts off the Mid
Atlantic coast. Extensive cirrus level cloudiness will thicken
through the day with morning sunshine fading behind increasing
clouds. Warm advection will boost temperatures into the mid 40s on
the lake plains of Western NY, and upper 30s to lower 40s for the
North Country. It will remain locally breezy at the northeast end of
Lake Erie and Lake Ontario with SSW winds gusting to 25-30 mph.


A weak cold front will approach the eastern Great Lakes Monday night
and Tuesday. A southerly flow will increase across the region as
surface low pressure moves into the Ozark Region. A weak shortwave
trough will round the base of a broad longwave trough across the
Great Lakes region. Moisture will increase ahead of the front while
a low-level jet moves into western and north central NY Monday
night. Overall, forcing is weak with the best convergence along the
nose of the LLJ as it moves from southern to central NY Tuesday
morning. Light rain showers are possible across western NY Monday
evening and will spread northeast into north central NY overnight.
Showers will likely increase in intensity near central NY as the
nose of the jet travels across the region. Surface temperatures will
be in the 30s Monday night and increase the second half of the
night. Locations across the southern Tug Hill region and Black River
Valley may stay near or below freezing and could potentially result
in a short period of freezing rain near daybreak Tuesday. Dry
conditions and a southerly wind overnight might hold this back so
confidence is low at this time. Liquid precipitation amounts will
range from a few hundredths across most locations to 0.20
inches east of the Lake Ontario Monday night. Low temperatures
will reach the 30s Monday night with the low 30s across the
southern Tug Hill region.

Warm air advection continues Tuesday with the low-level jet moving
east of the region. Dry, mid-level air will move into western NY and
showers will end from west to east through the afternoon. Low-level
moisture will result in cloudy conditions and potentially some
drizzle through the day. Showers will continue east of the Lake
Ontario through the afternoon. High temperatures will reach the mid
to upper 40s to the low 40s across the southern Tug Hill region.

The weak cold front will move into the region Tuesday night and
persist across the region through Wednesday. Multiple waves will
move along the front and result in a few rounds of rain showers
Tuesday night through Wednesday. Overall, dreary weather with
temperatures falling to the upper 30s to low 40s Tuesday night and
reaching the mid to upper 40s Wednesday. The front will move south
of the region Wednesday night but moisture will remain with no cold
or dry air advection behind the front. Shower chances drop overnight
but clouds and patchy drizzle may hold on until Thursday morning.
Low temperatures will fall to the 30s.


For this period there is still a bit of uncertainty with the timing
and development of cyclogenesis of a lee side low over the western
Plains mid-week. The 12Z GFS continues to be the faster solution of
the deterministic models with the advancement of an upper level
shortwave trough. While models are in general agreement that this
shortwave trough will close off and spiral over our region, the
faster GFS brings a milder airmass northward (with weaker surface
high over southern Canada) while the 00Z ECMWF/Canadian lags the
milder airmass to the south. Not only are there timing differences
but also precipitation type. Will leave PoPs at the chance category
at this point and time, centered upon Friday, and leave the weather
grids as snow/rain. But we could see some light wintry mix of
freezing rain or sleet mixed in with the surface high to our north
funneling shallow colder air southward.

Behind this first system, an upper level ridge will quickly pass
over our region to start the weekend. This will leave our region
generally quiet to start the weekend, but another system will be
bearing down upon us later in the weekend. This system and its
southerly flow lends rain/snow becoming all rain through the day.


Lake effect flurries and light snow showers will redevelop
northeast of Lake Ontario this evening with local LOW VFR/MVFR
VSBY/CIGS including at KART. The lake effect snow will end
overnight, with lake effect clouds also scattering out. Lake
effect clouds east of Lake Erie will move north across KBUF and
KIAG for a few hours this evening before dissipating. Elevated
winds will continue northeast of the Lakes tonight with gusts at
times in the 20-25 knot range.

Otherwise, VFR will prevail through Monday. Extensive high cirrus
will thicken and lower on Monday ahead of the next system. Elevated
winds continue into Monday with 20-25 knot gusts northeast of the
Lakes in the morning, expanding across all terminals from late
morning through the afternoon.


Tuesday through Wednesday...MVFR/IFR CIGS with rain showers likely
at times.
Thursday...VFR/MVFR CIGS and mainly dry.
Friday...MVFR/IFR with a chance of rain and wet snow.


Moderate southwesterlies will continue through tonight and gradually
back to SSW as high pressure builds from the Ohio Valley east to the
Mid Atlantic. This will maintain Small Craft Advisory conditions on
Lake Erie and Lake Ontario through a portion of Monday.

Light winds will return Tuesday and Wednesday as a weak trough moves
into the eastern Great Lakes and the pressure gradient relaxes.


MARINE...Small Craft Advisory until 7 AM EST Monday for LEZ020.
         Small Craft Advisory until 10 AM EST Monday for LEZ040-041.
         Small Craft Advisory until 1 AM EST Monday for
         Small Craft Advisory until 1 PM EST Monday for LOZ045.



NEAR TERM...Hitchcock/JM
LONG TERM...Thomas

NWS BUF Office Area Forecast Discussion