Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus61 kaly 190241 
afdaly

Area forecast discussion
National Weather Service Albany New York
941 PM EST Thu Jan 18 2018

Synopsis...
an upper level disturbance will bring some snow showers tonight
into early Friday for areas mainly north and west of Albany.
Generally dry weather is expected over the upcoming weekend,
with milder temperatures compared to our recent cold spell.

&&

Near term /until 6 am Friday morning/...
as of 940 PM EST, the forecast remains on track this evening
with low level clouds holding steady across most of the forecast
area. Minor tweaks made to the hourly temps and sky cover. Sent
updates to ndfd and web servers.

As of 640 PM EST, the latest GOES-16 satellite fog product
shows the expansive area of low level clouds across the majority
of the forecast area this evening, with upper level clouds
moving in from upstream. These low level clouds should keep
temperatures from plummeting tonight, with the exception of
southeastern New York where skies are currently clear. That
being said, only minor tweaks made to the forecast to reflect
recent trends in sky cover and temps. Sent updates to ndfd and
web servers.

Prev disc...as of 330 PM EST, low clouds are continuing to
gradually expand south and east, covering most areas near and
north of I-90. Some spotty light snow showers continue across
the far western Adirondacks and Mohawk Valley, with flurries
extending into the central/eastern Mohawk Valley, upper Hudson
Valley and portions of the capital region, as well as higher
terrain across southern Vermont and northwest Massachusetts.

Weak low/mid level warm advection will continue this evening. In
fact, forecast soundings suggest a warm layer between 800 mb-h7,
peaking slightly above 0c, with the coldest temps at or below
h925. Expect clouds to persist for most areas from I-90 north,
with occasional light snow grains/flurries.

Then, a potent shortwave currently traversing the northern Great
Lakes will approach after midnight. Synoptic forcing ahead of
this feature should work in tandem with lake moisture to produce
an increase in snow showers and flurries after midnight for
areas near and north of I-90. Up to an inch of accumulation
could occur across the far western Adirondacks, with mainly a
dusting to a few tenths of an inch possible elsewhere, including
lower elevations. There could be local enhancement across some
higher terrain of southern Vermont as well, where up to an inch or
two could occur.

With the expectation for more clouds than last night, and some
wind, expect milder temps overall from I-90 northward, with mins
mainly in the teens. Some locally colder temps could occur in
portions of the Mid Hudson valley and northwest CT, where more breaks
in the clouds and lighter winds are expected, some temps in
these areas could fall into the single digits.

&&

Short term /6 am Friday morning through Sunday/...
Friday, some lingering snow showers/flurries may be ongoing for
areas north and near I-90 in the morning, before areal coverage
decreases later in the morning through the afternoon. However,
low clouds may hang tough for many areas near and north of I-90,
as lake moisture remains trapped beneath a lowering subsidence
inversion, especially from late morning through mid/late
afternoon. Highs should be mainly in the 20s to lower 30s,
except milder across portions of the Mid Hudson valley. Winds
may tend to be brisk once again, especially within and close to
the Mohawk Valley/capital region and Berkshires, where gusts up
to 25 mph are possible.

Friday night-Saturday, a clipper like system will track east,
north of the Great Lakes region. A strengthening west/southwest
low level jet will develop across the region, with warm
advection ensuing. Low clouds from Friday should shift northward
in the evening, with clear to partly cloudy skies expected for
most areas through midday Saturday outside of the western
Adirondacks. Low clouds may tend to then expand back south and
east late Saturday into Saturday night as winds veer more into
the west/northwest. Friday night lows should be in the teens and
20s. Saturday highs should reach the 40s from Albany southward
in valley areas, and generally mid 30s to around 40 to the north
and west. Some drizzle or snow grains may develop across the
western Adirondacks later Saturday. Also, it should become quite
breezy Saturday, with some gusts possibly reaching 25-35 mph or
slightly stronger.

Saturday night-Sunday, the cold front associated with the
clipper system should gradually settle southward across the
region late Saturday night into Sunday. This should bring areas
of clouds, and perhaps some flurries/snow showers to some higher
elevation areas. Saturday night lows should be relatively mild,
mainly in the 20s, although if clouds become widespread enough,
could be even warmer in some lower elevations. For Sunday, highs
mainly in the 30s to lower 40s, although may tend to drop in the
afternoon across northern areas.

&&

Long term /Sunday night through Thursday/...
a strong storm is still forecast to develop across the center of the
nation later this weekend into early next week per the global model
consensus. Downstream impacts will be a warm front lifting
northward, or attempting too, as large Canadian high pressure
remains situated across James Bay/Hudson Bay vicinity which extends
its influence across New England. This could result in a wintry
mixture of weather developing from southwest to northeast overnight
Sunday into Monday.

Monday into Monday night, portions of our forecast area may remain
cold enough as low level ageostrophic flow remains from the north
despite the increasing low level southerly jet of near +3 Standard
deviations above normal. Furthermore, pwats are forecast to climb up
close to +2 Standard deviations above normal where the potential for
some moderate precipitation rates. Latest quantitative precipitation forecast amounts of around 1
inch with a little higher values into the higher terrain.

As a nearly vertically stacked low tracks across the Great Lakes
region, its associated dry slot approaches during the daylight hours
Tuesday. This should allow for a gradual reduction in precipitation
coverage and change the precipitation type to mainly liquid across
the region (exception appears to the be the dacks). This should be
the warmest portion of the long term period with mainly mid 30s-mid
40s.

Colder cyclonic flow and some lake effect activity will have the
chance for some snow showers in the wake of the storm tracking
northeast across the St Lawrence Valley. Highs Wednesday will
generally be in the 20s to mid 30s.

Temperatures look to average near to slightly above normal to
precipitation at or above normal.

&&

Aviation /03z Friday through Tuesday/...
VFR conditions should prevail tonight with an increase of
clouds expected overnight into the morning hours where MVFR
ceilings are expected to report. The only exception being kpou where
VFR conditions are expected through the forecast period. A few
scattered snow showers may be possible at kpsf/kgfl/kalb
tomorrow morning but due to areal coverage, did not include them
in the tafs at this time.

Northwesterly winds will become light and variable this evening
and turn out of the west. Westerly winds will prevail
throughout the day tomorrow, at around 5 to 10 kts.

Outlook...

Friday night: no operational impact. No sig weather.
Saturday: low operational impact. Breezy no sig weather.
Saturday night: no operational impact. No sig weather.
Sunday: no operational impact. No sig weather.
Sunday night: low operational impact. Slight chance of snow.
Monday: moderate operational impact. Chance of rain...sn.
Monday night: high operational impact. Likely rain.
Tuesday: high operational impact. Likely rain showers.

&&

Hydrology...
ongoing flooding due to ice jams will continue to be addressed
with areal flood warnings, as some lingering issues continue due
to existing ice jams which have become frozen in place. A
gradual warming trend will occur beginning this weekend,
although the degree of warming is not expected to be as
significant as what occurred last week. We will monitor trends
in temperatures due to potential impacts on existing ice jams.

In terms of precipitation, only some snow showers are expected
through Friday, with generally dry conditions expected over the
upcoming weekend. A period of mixed precipitation and/or rain is
possible early next week, although details on precipitation
types and amounts are uncertain at this time.

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.
New York...none.
Massachusetts...none.
Vermont...none.

&&

$$
Synopsis...kl/jpv

National Weather Service Glossary of Abbreviations