AREA FORECAST DISCUSSION
National Weather Service Albany NY
948 AM EST Fri Jan 27 2023
.SYNOPSIS...
A weak upper level disturbance will move across the
region today with mostly cloudy conditions and scattered snow
showers and flurries. A weak cold front approaches from the Great
Lakes Region tonight into Saturday with the best chance of snow
showers from the Capital Region northward. The boundary stalls over
southern New York and New England Saturday night and lifts northward
as a warm front on Sunday with chances of light snow and rain again,
as temperatures will finish the weekend above normal with breezy
conditions.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
The aforementioned warm front will be moving north of the region
Fri night, as the mid and upper level flow becomes
southwesterly ahead of the clipper low passing south of James
Bay. A brief period of clearing may occur north and east of the
Capital Region, but the southerly flow should increase ahead of
the mid and upper level trough and the next warm front.
Isentropic lift increases on the 290-300K surfaces, as some
moisture is tapped off Lake Ontario. Orographic enhancement
with the southwest flow in the boundary layer will increase the
chance of 1-3" of snow off the southwest Adirondacks in Hamilton
and Herkimer Counties prior to daybreak. The warm advection
ahead of the trough and front will bring chances of snow from
roughly the I-90 corridor and the eastern Catskills northward
prior to daybreak. Lighter amount snow of a coating to less than
half inch will be expected outside the southern Adirondacks,
and also the southern Greens, where an inch or two is possible.
Lows will be in the upper teens to upper 20s across the
forecast area as temps may steady or rising after midnight.
Saturday Night into Sunday...The cold front stalls over southern
NY and New England once again, as the mid and upper level flow
becomes nearly zonal ahead of the next wave approaching from the
Midwest and lower Great Lakes Region Saturday night. A partial
clearing of the clouds may occur north of the Capital Region,
as a 1028 hPa or so sfc anticyclone attempts to ridge in from
south-central Quebec. Mid and high clouds will be increasing.
Lows will generally be inn the mid teens to lower 20s north of
the Capital Region, and mid and upper 20s along and south and
east. As the warm advection increases Sunday morning, most of
the short-range guidance has some light snow moving back in over
the western Mohawk Valley and southern Adirondacks by daybreak
with light accums. The low pressure system tracks northeast of
the eastern Great Lakes Region and along or just north of the St
Lawrence River Valley. The best synoptic forcing will be north
and west of the Capital Region, where the highest PoPs in the
likely to categorical range were placed. The boundary layer
winds will increase out of the south/southwest once again, as it
will be breezy and additional light snow accumulations will be
possible over the southern Adirondacks, southern Greens, and
possibly the Lake George/northern Saratoga Region. Otherwise,
rain or a rain/snow mix from the Capital Region south. It will
be mild for the closing weekend of Jan...and it has been an
unusually warm Jan...as highs will range from the upper 20s to
mid 30s over the mtns, and upper 30s to mid 40s over the hills
and in the valleys, which were close to the NBM/EC MOS
guidance.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
Flow pattern through the long term will be characterized by a very
strong zonal upper jet/low-level thermal gradient laid out over much
of the eastern CONUS. This is the result of a southward-displaced
polar vortex centered around Hudson Bay and a persistent ridge over
the Gulf into the southeastern US. The thermal boundary is expected
to gradually slide southward through our area in response to
upstream shortwave energy digging into the Northern Plains and
zipping through the quasi-zonal flow in the Great Lakes/Northeast.
The first of these waves will likely generate some light snow Monday
north and west of the Capital District, with some assistance from
lake effect. Coastal low development is also expected, but is
strongly favored to remain well south of the area. Initial shot of
colder air is expected behind this lead wave for Tue/Wed, with temps
trending a bit below normal for the first time in a very long time.
Uncertainty exists with respect to precip chances in the Tuesday
night/Wednesday timeframe. Due to the strong thermal gradient near
the area, it won`t take much of a perturbation to result in a
frontogenetical response. 00Z.27 CMC shows this while the GFS/ECMWF
do not. Some support in the EPS/GEFS ensembles to warrant chance and
even some low likely PoPs, with the best chances the further south
one goes. An even colder push of air is likely in the wake of this
potential system (whether it occurs or not) by Thursday.