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fxus61 kbgm 220016 
afdbgm

Area forecast discussion
National Weather Service Binghamton New York
716 PM EST Tue Nov 21 2017

Synopsis...
a cold front entering New York from the west will bring chilly
temperatures and a quick shot of rain and snow showers to our
area early Wednesday morning. Light lake effect snow showers
will continue through midday across northern New York.

&&

Near term /through Wednesday night/...
715 PM update...
delayed the onset of precipitation by 2-3 hours later tonight,
as it appears the initial band of rain showers will not make it
in to our wrn New York counties until around 2 am...spreading ewd
through the overnight hours...mixing with snow and eventually
changing to all snow when the colder and drier air moves in by
the late morning hours. Otherwise, the rest of the forecast is
on track.

235 PM update...

While Tuesday felt more like a mid-October day with temperatures
well into the 50s, a storm system moving out of the Great Lakes
will combine with a deepening trof to bring a quick shot of rain
and snow showers, then much colder temperatures.

This frontal system is moisture-starved, so except where the
lakes are involved the precipitation will be short-lived. A
dusting to a half-inch of snow is forecast at the tail-end of
the precipitation early Wednesday morning.

A strong polar push behind the front will lead to a non-diurnal
temperature trend. Our maximum temperatures will occur Wednesday
morning, before readings fall throughout the afternoon.

Around an inch of snow is forecast downwind of Lake Ontario on
Wednesday. Winds will gust at 20 to 30 mph over the western
Mohawk Valley.

1055 am update...

Temperatures are rapidly warming this morning, with the latest
guidance continuing to point to maximums north of 50 degrees
this afternoon.

The grids are updated - mainly alterations to the near-term
temperatures - and should be available shortly.

&&

Short term /Thursday through Friday/...
3 PM update... overall, a quiet period is foreseen on
Thanksgiving day and Friday, which should be favorable for
traveling.

By Thanksgiving day, surface ridging building northward from the
mid-Atlantic states should lead to a mainly dry day. Any light
snow showers or flurries, well out ahead of a weak surface
boundary and southern Canadian short-wave should be
inconsequential, and relegated to our far northern zones
(southern Tug Hill region of cny). Afternoon highs should range
in the 30s.

The above mentioned weak disturbances may continue to bring some
flurries, sprinkles, or light rain/snow showers Thursday night
into Friday morning for upstate NY, before the systems lift away
to our northeast during the day Friday. Otherwise, dry weather
should persist, with partly sunny/partly cloudy skies. By Friday
afternoon, highs should range from the upper 30s-mid 40s.

&&

Long term /Friday night through Tuesday/...
315 PM update... although on the large-scale, a western
Canadian/western Continental U.S. Ridge and an eastern Continental U.S. Trough should
prevail in the upper levels, each of these features appear to be
on the flat side, which should allow a quick west-east progression of
systems through cny/nepa about every 2-3 days. It seems like
none of these systems will have time to acquire significant
moisture, so overall precipitation amounts look light. Also, on
average, temperatures should be near to slightly below normal
for late November.

As for the daily sensible weather, a short-wave and associated
surface cold front are slated to come through cny/nepa on
Saturday, accompanied by at least scattered rain showers. Colder
air will filter into the region behind the front, from the
second half of the weekend into early next week. This colder air
mass will combine with lingering low-level moisture and upper
troughiness, to bring the likelihood of lake-effect snow
showers for portions of cny. Early indications point to a
280-300 prevailing flow, which would favor some of our northern
zones in cny for at least nominal snow accumulations (cayuga,
Onondaga, Madison, and Oneida counties). Overall, moisture
appears shallow from this early Vantage Point, and a ridge axis
is also progged to quickly build towards cny/nepa from the west
by Monday. As a result, our initial inclination is that this
will not be a significant or longer duration lake-effect snow
event.

&&

Aviation /00z Wednesday through Sunday/...
cold front approaching the area from the Great Lakes will bring
showers and brief MVFR conditions late tonight and early
Wednesday. Lake effect snow showers behind the front may bring
some brief restrictions as well but much drier air and marginal
Delta T will limit the coverage and time of the snow showers.
VFR conditions will then prevail through the end of the taf
period.

Outlook...

Late Wednesday through Friday...mainly VFR.

Friday night through Saturday...possible restrictions in rain,
especially Saturday. Snow may also be mixed in early.

Sunday...VFR.

&&

Bgm watches/warnings/advisories...
PA...none.
New York...none.

&&

$$
Synopsis...djp

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