Schenectady, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

064
FXUS61 KALY 211503
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
1003 AM EST Thu Nov 21 2024

.SYNOPSIS...
Widespread rain will continue into Friday along with periods of
snow, especially in the higher terrain. Several inches of snow
accumulation will be possible in the Catskills, with up to a few
inches in higher terrain of the Adirondacks and southern
Greens. Precipitation tapers to valley rain and high-elevation
snow showers for the weekend, with continued cool and breezy
conditions.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
*Winter Weather Advisory now in effect for Schoharie County, as
 well as for Western Greene and Western Ulster Counties, from 4
 PM Thursday through 1 AM Saturday*

.UPDATE...As of 1000 AM EST, precipitation, mainly in the form
of rain, continues across much of the region early this morning.
Some snowflakes have fallen early this morning across portions
of the Catskills and Mohawk Valley (where surface temperatures
lowered to 32 to 34 degrees) as seen in area webcams with a
light dusting of accumulation on non- paved surfaces. Increased
forcing will allow precipitation to continue to expand in
coverage this afternoon and evening and precipitation types and
amounts will be dependent on temperatures, precipitation
intensity, elevation and the actual track of the surface low.
Outside of updating temperatures, especially in the Mohawk
Valley where values are 2-4 degrees lower than our previous
forecast, no significant changes were needed.

Previous Discussion:
Occluded sfc low is currently located over the Great Lakes
region, and is nearly vertically stacked beneath a potent upper
low. The system`s occluded front is currently located across
central NY, extending southeastwards through NY. A wave of low
pressure has already developed along this front beneath the left
exit of the upper jet, and should continue to deepen today is
it tracks northwards towards Long Island. Current radar imagery
shows widespread rain along and ahead of this front, which is
now currently advancing northeastwards into the upper Hudson
Valley and southern VT. Temperatures and dew points are mainly
in the 40s, so precipitation will be plain rain even for the
high terrain. Widespread rain is expected today, changing to wet
snow in the high terrain of the Catskills this afternoon and
early evening as the upper low slides over the Ohio Valley and
into PA, allowing cold air to wrap into the deepening surface
low. Rain will be mainly moderate through the day today, with a
few brief bursts of heavier rain. Nevertheless, with such dry
antecedent conditions, flooding does not look to be a concern.
Today will be several degrees cooler than yesterday, with highs
in the 40s for the valleys and temperatures dropping into the
30s for the high terrain.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
Rain changes to snow tonight in the high terrain, with several
inches of accumulation possible in the Catskills...

Tonight, the upper low tracks from PA into the NYC/Lower Hudson
Valley area. The surface low continues to deepen below 990 mb
as it gets captured by the upper low and abruptly takes a turn
to the west/northwest tonight, moving over the Mid to Lower
Hudson Valley by 12z Friday. Precipitation remains mainly rain
in the valleys, but the high elevations see a switch to snow
with colder air wrapping into the surface low from the
southwest. Once the low becomes vertically stacked late
tonight/tomorrow morning, it will begin to weaken and
precipitation becomes more showery, remaining rain in the
valleys and mostly snow in the high terrain. For valley areas, a
widespread 1 to 1.5" of liquid precip is expected, which should
help with ongoing drought conditions and fire weather over the
past few weeks.

Unfortunately, there remains some forecast uncertainty regarding
how far north and west the surface low will get pulled overnight
tonight. Today`s guidance shifted slightly further to the east
and slightly south with the track of the surface low. This could
reduce potential dry slotting issues cutting down on qpf in the
Mid Hudson Valley, while the shift to the east would also allow
for the colder air to make it further east. Will continue to
monitor trends through the day today regarding the surface low
and adjust accordingly for impacts on qpf and snowfall amounts.

The snow could come down heavily at times tonight in the
Catskills. The setup is not a perfect match to the pivoting snow
band conceptual model developed through collaborative CSTAR
research with SUNY Albany, although many of the necessary
elements are there in the synoptic setup tonight. low to mid-
level FGEN max looks to set up over or just west of the
Catskills as the sfc low backs in tonight, with the 700 mb low
tracking over or just south of the Catskills. This would shift
the best banding potential and highest snowfall rates just
west/southwest of our Catskill zones, which is supported by the
WPC snowband probability tool. Nevertheless, this remain a
dynamic system with plenty of potential for diabatic cooling and
E/SE low-level flow to lead to enhanced snowfall totals across
the higher terrain of western Greene and Ulster Counties. While
we do have warning-level criteria snowfall across portions of
these areas, we did not have enough geographic coverage of these
higher-end amounts to warrant upgrading the advisory to a
warning. The heaviest snows will likely occur near the Big
Indian Wilderness, Slide Mountain Wilderness, and Hunter
Mountain where up to 10" of snow will be possible. The snow will
be of a wet, heavy consistency initially with rations less that
10 to 1, so the weight of the snow could lead to some downed
tree limbs possibly resulting in power outages.

Friday night through Saturday...Upper low slides off the NJ
coast in tandem with the vertically stacked sfc low. With moist
cyclonic flow aloft wrapping around the upper low, we will
continue to see cloudy skies and scattered valley rain/high-
terrain snow showers, but these should diminish in coverage and
become lighter through the period. One potential adjustment to
previous forecasts that will need to be watched is the potential
for an additional period of rain/snow across western New England
Friday night or Saturday as yet another sfc low develops off the
east coast and tracks towards New Brunswick. If this were to
occur, as some sources of guidance now show, then additional
light snow accumulations would be possible in the southern
Greens. Otherwise, we should see a gradual drying trend Saturday
afternoon aside from some light lake effect rain/snow showers in
the western ADKs and western Mohawk Valley. Friday night will
feature lows in the 20s to 30s, with Saturday`s highs in the 30s
(terrain) to 40s (valleys), which will be similar to Friday`s
high temps.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
Vertically stacked low pressure will be well off the east coast into
Nova Scotia to start the long term period, though its effects will
still be felt across the region as we close out the weekend.
Lingering moisture and lift wrapping around the low in northwest
flow will continue to work across the Northeast Saturday night into
Sunday, and will keep rain and snow chances in place. The best
chance of precipitation will be mainly in the western Mohawk Valley
and ADKs in the lake effect belts, though low chances (20-40%) are
in place for areas north of the Mid Hudson Valley with CVA moving
into the region. Sunday will be quite breezy as well with gusts
around 25-35 MPH as a tight pressure gradient between the departing
low to the east and building high to the west will be in place.
Temperatures will be quite chilly with highs ranging from the 30s
in higher elevations to mid/upper 40s in valley locations.

We get a brief break in the weather Sunday night into daytime Monday
with high pressure quickly skirting across the area from southwest
to northeast. However, yet another round of low pressure will follow
for the region Monday night and Tuesday with a mix of rain & snow
expected. Chances have increased in this fcst (50-80%), though the
exact amount of precipitation expected remains uncertain.
Temperatures will start out above normal with highs Monday and
Tuesday ranging from around 40 (terrain) to low 50s (valleys) before
falling into low 30s (terrain) to low 40s (valleys) Wednesday.

Deterministic solutions diverge heading into the Thanksgiving
holiday, though some suggest active weather with chances of rain &
snow will persist as another robust system passes near the area.
Look for additional changes to this period in subsequent fcst.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
Through 12Z Friday...Flying conditions will continue to deteriorate
to MVFR/IFR over the next several hours as a system brings a steady
rain across the region. These low ceilings and visibilities will
persist through the remainder of the period at all terminals as the
system slowly traverses the area. Light & variable winds initially
will increase out of the east to northeast around 10 kts after
daybreak, and will shift to the northwest mainly at KPOU/KALB as the
surface low nears the terminals late in the period. KPSF will also
see LLWS late in the period with a 40-50 kt LLJ passing near the
terminal.

Outlook...

Friday Night: Moderate Operational Impact. Chance of SHRA.
Saturday: Moderate Operational Impact. Breezy. Chance of SHRA.
Saturday Night: Moderate Operational Impact. Breezy. Chance of SHRA.
Sunday: Low Operational Impact. Breezy. NO SIG WX.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.
Monday Night: High Operational Impact. Likely SHRA.
Tuesday: Moderate Operational Impact. Breezy. Chance of SHRA.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Winter Weather Advisory from 4 PM this afternoon to 1 AM EST
     Saturday for NYZ047-058-063.
MA...None.
VT...None.

&&

$$

SYNOPSIS...Main/Rathbun
NEAR TERM...Main/Rathbun
SHORT TERM...Main
LONG TERM...Speck
AVIATION...Speck