636
FXUS61 KBUF 221406
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
906 AM EST Fri Nov 22 2024

.SYNOPSIS...
Strong 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
mainly dry weather returns later Sunday.

&&

.NEAR TERM /THROUGH TONIGHT/...
Widespread precipitation is falling across the region this
morning, with mainly a chilly rain for lower elevations and wet
snow across higher terrain.

A strong and broad mid level closed low will continue to meander
across southern New England and the northern Mid Atlantic region
through tonight. At the surface, a deepening coastal low will make a
cyclonic loop today, moving back westward across southeast NY, then
looping down across eastern PA before heading back offshore of New
Jersey tonight. The highly occluded and cutoff nature of the system
will continue to support a complex evolution of forcing, moisture,
and thermal profiles through tonight.

The most widespread precipitation will continue across our region
through midday as an axis of deep moisture pivots back westward
within the warm conveyor of the cyclone. Mid level stretching
deformation and frontogenesis on the northwest flank of the system
will support a band of moderate precipitation moving westward across
the area today. A dry slot wrapping into the system will reach the
eastern Lake Ontario region by early afternoon, then spread westward
across the rest of the area, allowing the widespread precipitation
to taper off from east to west.

Precipitation type will continue to be highly dependent on elevation
today through tonight. Snow will continue to be dominant across the
higher elevations of the Southern Tier, western Finger Lakes, and
Tug Hill Plateau through this morning. An area of slightly warmer
air aloft and at the surface will continue to wrap back off the
Atlantic Ocean, with weak warm advection from the northeast today.
This, combined with some modest diurnal warming, will allow snow
levels to rise slightly today, with any snow limited to the highest
elevations by this afternoon.

Additional snow accumulation this afternoon and tonight will be
limited to higher elevation, and for most will be less than 2
inches.

Tonight, the widespread precipitation will continue to
move westward, tapering off in Western NY during the evening.
Moist cyclonic northerly flow will persist overnight, and this
will support some limited lake effect and upslope rain/snow
showers south of the lakes and across higher terrain. The area
of deeper moisture and old deformation zone will linger from
Southwest Ontario into eastern PA/western Ohio. This feature,
combined with upslope and lake effect, may support a
continuation of somewhat more persistent rain and wet snow
across the Chautauqua Ridge.

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

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
This period starts out with the area of low pressure continuing to
move off the east coast. Northwest flow in place behind the exiting
low will lead to an uptick in lake/upslope precipitation with
showers expanding across areas east and southeast of the lakes. 850
mb temperatures not all that cold and forecast to be around -2C/-3C,
therefore expect the bulk of the precipitation to be in the form of
rain during the day Saturday, with only the higher hilltops seeing
the risk for some wet snow showers. Any accumulation will be limited
to less than an inch. High temperatures for most spots getting into
the 40s, with some upper 30s lingering across the higher terrain.

Colder temperatures aloft arrive Saturday night with 850 mb
temperatures dropping to near -6C, but drier air also arriving which
will limit lake the lake response. Snow showers east and southeast
of the lakes should see very little in the way of accumulation.

Lingering lake effect mixed rain and snow showers Sunday morning,
will dissipate as conditions dry out by the afternoon as high
pressure and warmer air aloft build into the region.

Sunday night continues to look dry as high pressure settles across
the area.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Surface high pressure will briefly ridge across the region Monday
morning, resulting in mainly fair and milder weather for the day.
After this, a mid level trough will dig into the upper Great Lakes
leading to a surface low developing and tracking across the eastern
Great Lakes Monday night into Tuesday. This will bring a shot of
widespread rain showers with modest rainfall amounts around a
quarter inch. 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 /14Z FRIDAY THROUGH TUESDAY/...
Widespread rain across lower elevations and rain/snow mix across
higher terrain this morning. 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. It will become 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.

Outlook...

Saturday...VFR/MVFR with a few rain and wet snow showers.
Sunday...VFR/MVFR with a chance of a rain or snow shower.
Monday...VFR/MVFR with a chance of rain.
Tuesday...MVFR with rain and snow showers possible.

&&

.MARINE...
A moderately deep surface low will loop from southeast NY down
across eastern PA today before moving back offshore of New Jersey by
this evening. N/NE winds will increase today, bringing high end
Small Craft Advisory conditions to Lake Erie and Lake Ontario.

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...Winter Weather Advisory until noon EST today for NYZ008-012-
     019>021.
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...Hitchcock
NEAR TERM...Apffel/Hitchcock
SHORT TERM...TMA
LONG TERM...Apffel/TMA
AVIATION...Apffel/Hitchcock
MARINE...Apffel/Hitchcock