Albany, NY WFO Forecast Discussion

326
FXUS61 KALY 131207
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
707 AM EST Mon Jan 13 2025

.SYNOPSIS...
Snow showers and a few snow squalls today before lake effect
snow develops off Lake Ontario and extends into the western
Adirondacks late this afternoon through Tuesday night.
Otherwise, we turn cold and windy Tuesday and Wednesday before
we finally trend milder than normal late in the week into this
weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Key Messages:

- There is a 30 - 50% chance for scattered snow showers and a
  few isolated snow squalls this afternoon, mainly in the Mohawk
  Valley, including part of the Monday P.M commute. Brief
  periods of reduced visibility and hazardous travel are
  possible during any snow squall as temperatures quickly drop
  below freezing.

- A single lake effect snow band developing off Lake Ontario
  extends into northern Herkimer County late this afternoon
  leading to periods of moderate snowfall within the band.

Our warm front continues lifting north and east through the
region this morning with GOES16 IR imagery showing a mid-level
cloud deck tracking eastward along with a few warm air advection snow
showers moving into the western Adirondacks.

Clouds break for some partial sun later this morning as we
enter into the relative warm sector, except in the
western/southern Adirondacks where upslope flow maintains the
cloud coverage and some weak snow showers. Southerly flow
combined with breaks of sun will allow temperatures to turn
mild again by early afternoon rising into the mid to upper 30s
with even low-40s in the mid-Hudson Valley. Cooler in the
western/southern Adirondacks where clouds will keep temperatures
in the upper 20s.

Our arctic cold front tracks from west to east this afternoon.
Given cooling aloft and weak low-level convergence along the
thermal boundary, expecting isolated to widely scattered snow
showers ahead of the boundary. A few isolated snow squalls are
even possible, mainly in the Mohawk Valley into parts of the
Capital District, given steep low-level lapse rates, a moist
and well-mixed boundary layer seen on forecast soundings and
sufficient low- level instability. The snow squall parameter
shows elevated values mainly in central NY but higher values
spill into the Mohawk Valley 18 - 21 UTC which includes part of
the Monday P.M commute. Brief periods of reduced visibility can
occur during any snow squall along with gusty winds up to
25-30kts and a quick coating to less than 1 inch of snow. This
can lead to hazardous travel conditions as initially above
freezing temperatures rapidly cool into the 20s leading to a
quick refreeze. The most favorable ingredients for snow squalls
are mainly west of the Capital District but scattered snow
showers can still track east into the Tri-City area during the
P.M commute leading to brief reduced visibility and slippery
travel. In collaboration with WFO BTV, we issued a Special
Weather Statement to give a heads-up on the potential for
isolated snow squalls this afternoon. Given overall weak low-
level forcing, snow showers lose their punch and weaken further
as they head into western New England by early evening.

Immediately behind the arctic front, westerly flow and strong cold
air advection quickly develop off Lake Ontario, supporting an
organized single lake effect band. High res guidance is in good
agreement indicating the band initially develops just north of
Herkimer County this afternoon before winds veer to west-
northwest, directing the lake band southward into far northern
Herkimer County by 21 - 00 UTC.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
Key Messages:

- Lake effect snow expected in the western Adirondacks late this
  afternoon through Wednesday. Moderate to heavy snow
  accumulations reaching 5 - 9 inches expected in northern
  Herkimer County with snowfall rates ranging 0.5 to 1 inch per
  hour at times through Tuesday. Highest accumulations near and
  north of Route 28.

- Becoming cold and windy Tuesday and Wednesday with 50 - 90%
  confidence that daytime temperatures fall below 25 degrees
  and 50 - 75% confidence for wind gusts to exceed 25 mph both
  days.

Persistent cold air advection and west-northwesterly in the low
and mid- levels will maintain the organized lake effect snow
band off Lake Ontario into northern Herkimer County tonight
through Tuesday. Lake induced instability is not overly
impressive tonight which will keep snowfall rates near or under
0.5 inch per hour as the band gradually shifts southward through
northern Herkimer County. Once the low and mid-level flow
become oriented more westerly and nearly parallel with the long
fetch of Lake Ontario 12 - 15 UTC Tuesday, snowfall rates
increase as lake moisture and lake induced instability become
enhanced. Guidance from the HREF suggests 10 - 20% chance for
snowfall rates to exceed 1 inch through the day; however, the
residence time of the lake effect band in a given area is not
expected to be terribly long and limited to perhaps just 6 - 12
hours as the flow continues to gradually veer through the
afternoon and the band slowly slides southward. The band
eventually heads south of Route 28 by or shortly after 18 UTC
Tuesday before the main shortwave trough swings through the
Northeast by 00 - 03 UTC Wednesday. The low and mid-level flow
quickly shift to the northwest in the wake of the trough axis
which will induce more directional shear and disrupt the lake
band. Expecting a transition into more multi-bands Wednesday
night as lake effect snow showers track further south reaching
the Mohawk Valley but still only expecting a few tenths up to 1
inch of snow. Current lake effect snow warning and winter
weather advisory for lake effect snow in northern Herkimer and
Hamilton, respectively, continue through 12 UTC Wed but we may
end up canceling these headlines early as the lake effect
diminishes overnight.

Outside of the lake effect, Tuesday will feature a tight sfc
pressure gradient, cold air advection, and mainly sunny skies in
valley areas. This will be a recipe for quite the chilly day as
insolation supports deep boundary layer mixing enabling gusty
winds to reach 25 - 30kts. With high temperatures limited to the
mid and upper 20s and teens in the western Adirondacks,
northern/eastern Catskills and southern Greens, the gusty winds
will make it feel even colder more like teens and single digits.
In addition, expecting upslope snow showers to develop in the
southern Greens and norther Taconics daytime Tuesday into
Tuesday evening resulting in 1 to 3 inches of snow as the low
and mid-level flow becomes more westerly and eventually
northwesterly in the wake of the trough axis. Overnight lows
drop into the teens with single digits in the western
Adirondacks and southern Greens.

We remain gusty and cold into Wednesday under partly to mostly sunny
skies (cloudier in the western Adirondacks and western Mohawk
Valley) with the lake effect snow showers positioned south of
the Mohawk Valley thanks to the northwesterly flow regime.
Daytime highs again will be limited to the 20s with teens in the
southern Adirondacks, northern/eastern Catskills, and southern
Greens. Feel-like temperatures given gusty northwest winds
reaching 20-25kts range from the teens to low 20s with single
digits in the aforementioned colder areas. We turn even colder
Wed night as the winds finally weaken. Once the lake effect snow
showers retreat northward through Mohawk Valley and western
Adirondacks, skies turn partly to mostly clear. This will
support radiational cooling and allow temperatures to drop into
the single digits and low teens through much of the area. Sub-
zero readings for the southern Greens and southern Adirondacks.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Key Message:

- Temps moderate to near seasonal levels by Friday.

- Next chance for widespread precipitation is on the weekend with a
  mix of rain and snow as temperatures trend slightly above normal.

Weak ridging aloft moves over NY and New England to begin the
extended forecast period.  Some lake moisture will be tapped for
isolated to scattered snow showers due to warm advection ahead of a
warm front and short-wave in southwest flow that will impact the
western Mohawk Valley and southern Adirondack Region.  Some PoPs in
the 40-60% range based on the latest NBM were used in the western
Dacks for light amounts of snow Thu-Thu night.  Highs will run below
normal in the cold air mass with teens to lower 20s over the mtns
and mid 20s to around 30F in the valleys and hills.  Lows Thu night
will be mainly in the teens.  Snow showers should diminish on Friday
with the trough axis moving downstream and flat mid and upper level
ridging building in over eastern NY and western New England with
temps moderating to seasonal readings with lower to mid and spotty
upper 30s in the  valleys and 20s to lower 30s over the higher
terrain.  Clouds increase with a warm front moving across the region
Fri night with isolated to scattered snow showers/flurries with lows
in the upper teens to mid 30s.

The ridge weakens along the East Coast, as broad southwesterly flow
sets up, as a cold front approaches the region. A low pressure
system moving northeast from the Midwest may bring a period of rain
and snow depending on the track and placement of the front late Sat
into Sat night. There continues to be quite a bit of spread in the
ensembles and medium range deterministic guidance on the placement
of the cyclone and how quickly the front moves through. We followed
the NBM guidance and have some snow transition to rain, but as the
cold front sags south with the wave passing to the northeast, then a
brief period of snow may return Sat night. Temps rise above normal
on Saturday, but fall near to below normal by Sunday. In the broad
southwest flow with the longwave trough over the CONUS, another
short-wave and developing wave near the East Coast may bring another
chance of snow showers/light snow to close the weekend. PoPs were
kept in the slight to low chance range (15-35%).  Temps will finish
near to slightly below normal

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
Through 12Z/TUE...VFR conditions are expected at KGFL/KALB/KPOU/KPSF
prior to 18Z/MON with low to mid level clouds this morning in the 6-
12 kft AGL. KPOU will go scattered until the short-wave and cold
front approaches. Some isolated to scattered snow showers with an
embedded snow squall are possible 20Z/MON - 00Z/TUE with brief
MVFR/IFR vsby and MVFR cigs at KGFL/KALB/KPSF with the PROB30 group
in the 20Z/Mon - 00Z/TUE. Expect cigs/vsbys to rise back to VFR
levels after 00Z/TUE with cigs in the 3.5-6 kft AGL range. The skies
will clear south and east of KALB with few-sct clouds 4-6 kft AGL.

The winds will increase from the south to southwest at 5-10 KT in
the late morning into the afternoon with a few gusts 15-20 KT at
KALB. The winds will veer to west with the frontal passage in the
late afternoon into the evening at 8-12 KT with some gusts around 20
KT at KALB/KPSF. Some gusts 20-25 KT may happen with any isolated
squalls this afternoon into tonight.

Outlook...

Tuesday Night: Low Operational Impact. Breezy. NO SIG WX.
Wednesday: Low Operational Impact. Breezy. NO SIG WX.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: No Operational Impact. NO SIG WX.
Thursday Night: No Operational Impact. NO SIG WX.
Friday: No Operational Impact. NO SIG WX.
Friday Night: Moderate Operational Impact. Chance of SHSN.
Saturday: Moderate Operational Impact. Likely RA...SN.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Lake Effect Snow Warning from 4 PM this afternoon to 7 AM EST
     Wednesday for NYZ032.
     Winter Weather Advisory from 4 PM this afternoon to 7 AM EST
     Wednesday for NYZ033.
MA...None.
VT...None.

&&

$$

SYNOPSIS...Speciale
NEAR TERM...Speciale
SHORT TERM...Speciale
LONG TERM...Wasula
AVIATION...Wasula

NWS ALY Office Area Forecast Discussion