Albany, NY WFO Forecast Discussion

Forecast Discussion for ALY NWS Office
000
FXUS61 KALY 250903
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
403 AM EST Sat Jan 25 2020

.SYNOPSIS...
A storm system will bring precipitation to the region
later this morning through this evening, with mainly rain for valley
areas from Albany south and east, and a mix of snow, sleet and
freezing rain changing to rain to the north and west, as well as
across higher elevations of western New England. Steady
precipitation will taper off this evening, with snow showers and
flurries expected for Sunday into Monday in the wake of the storm.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Winter Weather Advisory in effect from 7 AM to 4 PM for the
eastern Catskills, Schoharie County, Helderbergs, western
Mohawk Valley, and southern Saratoga region...

Winter Weather Advisory for 1 PM Saturday until 4 AM Sunday for
the southern Adirondacks, Lake George Saratoga region, southern
Vermont, and Berkshires...

As of 4 AM EST, thin spots in the clouds have allowed for some
areas of decoupling within portions of the Hudson Valley, where
temps have dropped into the mid teens to lower/mid 20s. Temps
remain elevated across western New England, especially
downstream of the higher terrain, where temps are in the
lower/mid 30s. Temps are in the mid 20s to lower/mid 30s across
the western Mohawk Valley and SW Adirondacks.

Given such a cold start with low dewpoints across many areas
this morning, we have expanded coverage of winter weather
advisories south and east to northern portions of the Capital
Region, all of the Mohawk Valley, and into the Berkshires and
extreme southeast VT. Models suggest some spotty light
precipitation possibly developing from a mid level cloud deck
for areas from Albany and points south and west as early as mid
to late morning. We have therefore kept early start time of
winter weather advisory for these areas (7 AM), while delaying
until 1 PM to the north and east, although if precipitation
expands more quickly, this start time may need to be pushed
slightly earlier.

P-type may initially be a mix of sleet/wet snow, even in some
valley areas, where a quick coating of snow/sleet could occur.
However, quick warming aloft should allow precipitation to
become freezing rain or rain shortly after developing. With a
general east to northeast low level flow developing, cold air
may become trapped and/or reinforced via wet bulb cooling
processes across portions of the Mohawk Valley, higher
elevations of the Berkshires, as well as extreme SE VT adjacent
to the CT River Valley. We therefore have expanded advisories
into these areas. Some models suggest ice accretion could reach
one quarter of an inch or even higher across higher terrain of
the Berkshires, southern Greens, and possibly southern
Adirondacks. However, cold air may remain slightly deeper across
portions of the southern Adirondacks and SE VT, where 1-2 inches
of snow/sleet could occur before any freezing rain.

Some patchy freezing rain could even occur as far south as the
Litchfield Hills, and trends will need to be watched in case an
expansion of the current advisory is required.

Rain may become moderate to heavy late this afternoon across the
SE Catskills, mid Hudson Valley into NW CT.

Gusty east winds will develop across higher terrain of the
Taconics, Berkshires, and southern Greens this morning, peaking
this afternoon and evening, when some wind gusts could reach
40-45 mph.

Late day highs mainly in the 30s across the region, although
could reach to around/over 40 immediately downwind of some
higher terrain areas across western New England and the
Berkshires.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
Band of moderate to locally heavy precipitation should continue
translating northeast between 7 and 10 PM this evening, with
most of the steady precipitation ending shortly thereafter. In
the wake of this band associated with the occluded front and
secondary low pressure system, some clearing may occur in valley
areas south of Albany. This may allow for some patchy/areas of
dense fog to develop, and also could promote black ice formation
as temps dip to around or just under the freezing mark.
Elsewhere, clouds and some wind should keep temps slightly
elevated, although will have to watch for slightly colder temps
in valley areas should breaks in the clouds develop farther
north. Also, some snow showers will become possible toward
daybreak across the southeast Catskills ahead of a strong PV
anomaly approaching from the southwest.

This PV anomaly will translate northeast across the region
Sunday morning, and may allow for a band of snow showers to
develop along its leading edge. In its wake, snow showers and
flurries should become more scattered in coverage, except
across northern Herkimer and Hamilton Counties, where a
combination of Lake Enhancement and orographic snow within the
low and mid level cyclonic flow regime should allow for frequent
snow showers to develop, with light accumulations possible.
Otherwise, it will become breezy with temps reaching the mid 30s
to around 40 in valley areas, and upper 20s to lower 30s for
higher elevations.

Persistent snow showers will continue across northern
Herkimer/Hamilton Counties Sunday night into Monday, with
several inches of snowfall possible. Elsewhere, scattered snow
showers and flurries will continue, especially areas north of
I-90. A few inches could also occur across higher elevations of
the southern Greens. Lows Sunday night in the mid 20s to
lower/mid 30s. Highs Monday mainly in the 30s.

A reinforcing cold front should pass through Monday night,
possibly increasing areal coverage of snow showers. Lows mainly
in the 20s to lower 30s.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
Overall, upper level pattern during this period shows mainly
troughing across the eastern part of the U.S. with ridging across
eastern Canada and ridging building into the western U.S. At the
surface, high pressure slowly builds southeast from central Canada
so that`s it almost overhead by Friday. For most of the period the
weather looks fair with a cold northerly flow. However, models do
indicate a number of weak shortwaves embedded in the flow which
could produce occasional cloudy periods and some light snow showers
over mainly the higher terrain. Overall, little in the way of
precipitation expected during the period.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
Low pressure near Chicago tonight will move slowly northeast
to Ontario during the next 24 hours. This system will bring
clouds, precipitation and lower ceilings from late morning today
through the rest of the TAF period ending 26/06Z.

VFR conditions will continue into this morning with some mid
and high clouds increasing. A stratus deck around 1500 ft msl
has arrived from the east at KPSF and may also reach KPOU toward
sunrise.

Precipitation in the form of mainly rain will impact the
terminals between 18Z-03Z/SAT. Cigs/vsbys will lower to
IFR/MVFR levels. Rain may be mixed with sleet at the onset and
may end as some wet snow this evening.

LLWS will become a problem all TAF sites from 14Z through around
26/03Z.

Light to calm winds tonight will increase from the north to
northeast at 5-10 kts, and then further increase in the
afternoon from the northeast to southeast at 8-15 kts with some
gusts in the 20-25 kt range at KPSF.

Outlook...

Sunday Night: Moderate Operational Impact. Slight Chance of SHSN.
Monday: Low Operational Impact. Breezy. Isolated SHRA...SHSN.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: No Operational Impact. NO SIG WX.

&&

.HYDROLOGY...
A storm system will bring rain and a brief period of freezing
rain or sleet to the region later this morning into early this
evening. Valley areas should experience a period of steady,
moderate to briefly rainfall, which may result in some ponding
of water on roadways and in other low lying areas, especially
due to the frozen ground. Total precipitation will generally
range between 0.50 and 1.25 inches which may result in some
rises on rivers and streams (especially across the eastern
Catskills and western New England), but flooding is not
expected. Dry weather will then return for early next week,
allowing flows to recede.

For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our website.
&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Winter Weather Advisory from 7 AM this morning to 4 PM EST
     this afternoon for NYZ038>040-047>051-058-063.
     Winter Weather Advisory from 1 PM this afternoon to 4 AM EST
     Sunday for NYZ033-041>043-083-084.
     Winter Weather Advisory from 7 AM this morning to 4 AM EST
     Sunday for NYZ082.
MA...Winter Weather Advisory from 1 PM this afternoon to 4 AM EST
     Sunday for MAZ001-025.
VT...Winter Weather Advisory from 1 PM this afternoon to 4 AM EST
     Sunday for VTZ013>015.

&&

$$
SYNOPSIS...KL/Speciale/Wasula
NEAR TERM...KL/Wasula
SHORT TERM...KL
LONG TERM...SND
AVIATION...SND
HYDROLOGY...KL/Speciale

NWS ALY Office Area Forecast Discussion