Area Forecast Discussion
Issued by NWS Burlington, VT-- Highlight Changed Discussion --
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FXUS61 KBTV 140458
Area Forecast Discussion
National Weather Service Burlington VT
1158 PM EST Fri Jan 13 2017
Mostly clear and much cold conditions are expected tonight as
surface high pressure builds in from the Great Lakes region. This
area of high pressure will bring mostly sunny conditions with
lighter winds for Saturday. A weak upper level disturbance will
bring a few mountain snow showers late Saturday night, with
clouds expected to persist across much of Vermont and northern
New York on Sunday. High temperatures this weekend will mainly
be in the upper teens to mid 20s. Temperatures are expected to
trend back well above normal for much of next week.
.NEAR TERM /THROUGH SATURDAY NIGHT/...
As of 918 PM EST Friday...Previous forecast still on track.
Winds continue to diminish thus should see a more rapid fall in
temperatures as this occurs.
Afternoon Discussion...Clearing trend continues across
northern New York and Vermont this afternoon as colder/drier air
mass moves in from the WNW. Increasing sunshine and low-level
cold air advection has led to steep lapse rates and gusty
winds, which will persist for several more hrs this afternoon.
Getting 26 mph sustained with gusts to 36 mph at BTV at 2015Z,
and will see some gusts 30-40 mph thru the late afternoon
hours areawide, before lessening after sunset. Temperatures are
generally in the 20s, except 35F at Springfield VT with some
local downslope effects in nw flow. Anticipate temperatures
slowly falling this afternoon despite sunshine, and the falling
more quickly after sunset as boundary layer decouples and skies
Surface anticyclone crests over our region at 12Z Saturday. Will
continue to see some gusty W-NW winds for a time tonight, and
may see a period of wind chills 10 to 20 below across the
Adirondacks and far nern VT before abating after 06Z. Overnight
lows will be cold, but absence of snow cover will mitigate the
degree of radiative cooling a bit. Looking for readings in the
single digits above zero in the Champlain Valley, and zero to
-10F elsewhere, coldest in the nrn Adirondacks and far nern VT.
High pressure moves east of our longitude on Saturday with light
S-SW winds developing and plenty of sunshine. Looking for highs
in the upper teens to lower 20s. No precipitation is expected
tonight or Saturday.
A weak upper level shortwave glances far nrn/nern VT after 06Z
Sunday. Have included PoPs 20-30 percent for snow showers or
flurries 06-12Z Sunday, and skies trending mostly cloudy across
the area. Could see a minor accumulation (dusting to 1") of
very dry snow (20:1 snow-to-liquid ratios) across the nrn
Adirondacks and n-central/nern VT during the pre-dawn hours
Sunday. Not expecting any travel issues. Lows not as cold
Saturday night due to increasing clouds; mainly in the teens,
except 5-10F across the nrn Adirondacks and the colder valleys
of Vermont`s Northeast Kingdom.
.SHORT TERM /SUNDAY THROUGH MONDAY/...
As of 240 PM EST Friday...12z suite of guidance still
indicating a pretty quiet for the latter part of the holiday
weekend. In general, pretty big high pressure will be in
control. That said, there are a couple of minor items that will
impact some aspects of the sensible weather we will see,
Models still show a weak short wave trough passing by to the
north of the region first thing Sunday. Between that, some low
level (900mb/4500ft and below) moisture and northwest/upslope
flow, we should be able to squeeze out some flurries across the
higher terrain of northern Vermont during the morning. Did
enhance the cloud cover until mid-afternoon as that low level
moisture and some blocked flow will probably mean pesky clouds
will be around a bit longer than would otherwise be expected
given the deep layer drying that will be occurring.
Sunday night will be mostly clear. With relatively light winds,
we`ll have some decent radiational cooling going on, especially
in areas with snowpack. Temperatures will probably flirt with
sub-zero across parts of northeast VT and the Adirondacks,
especially normally colder locations. Teens elsewhere.
MLK Day is still looking high and dry under fairly strong high
pressure. Temperatures will warm a little aloft as the flow
becomes more westerly, so we should top out in the upper 20s to
lower 30s. About 5F degrees above normal.
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 230 PM EST Friday...General scenario of an unsettled but
mild mid to late week for the area is still on track as low
pressure will move by to our west giving us another round of
mostly rain. Models continue to struggle with specifics, and the
12z GFS reversed it`s recent trend and is showing precipitation
moving in a little faster now on Tuesday. Trended a little more
toward the slower 12z Euro to show Tuesday mostly dry. Bulk of
the precipitation is expected Tuesday night into at least the
first half of Wednesday. Given the temperature profiles, most of
this will be rain. Could be a bit of a wintry mix across the
higher terrain/`Dacks/eastern VT but a bit too early to pinpoint
those specifics which result from just small changes in the
temperature profile. Kept with the simplistic idea of a
rain/snow mix deal based on forecast temperatures. Suspect
guidance is a bit too cold for Tuesday night given all the
clouds and precipitation. Did raise overnight lows several
degrees, but that may still be a bit too cool. We`ll see how
later guidance trends in that arena. Wednesday will still be
mild, as there is just no cold air with this system. Stayed
close to guidance on over precipitation chances. 12z Euro now
shows a weak surface low developing and moving just to our south
Wednesday night bringing a secondary round of precipitation
which would again be primarily rain given it`s 850mb
temperatures around +5C. 12z GFS meanwhile has a shortwave come
through as 850mb temperatures are falling to below 0C,
suggesting a brief shot of rain/snow showers early Wednesday
night. For the forecast, just took a blend of the current and
prior runs, so I will show a trend of rain turning to some snow
in colder locations. Whatever does turn out, it doesn`t appear
we would be looking at any real snowfall accumulations. Lastly,
Thursday appears quieter. 12z suite shows various stages of
drier weather moving in. 850mb temperatures will either be
around -2C (per ECMWF) or -7C (per GFS). Either way, daytime
highs will be above normal. Again, stuck with model guidance
blend which incorporates some previous model runs which showed
the warmer solution to be more likely at this point.
.AVIATION /06Z Saturday THROUGH Wednesday/...
-- Changed Discussion --Through 06Z Sunday...VFR conditions with mostly clear skies for
the period. With arctic air moving in, may see some Lake
Champlain induced clouds 08-12Z Saturday, and could see SCT-
BKN015-020 somewhat close to BTV for a few hrs early Saturday
morning. Main band of lake clouds should be to the west of
BTV, but have included a SCT020 with a tempo window of BKN020
from 08Z-12Z just in case the clouds make it to over the
Currently winds are light out of the northwest at 05-10 and
will continue to weaken overnight. Winds will become light S-SW
during the day Saturday.
06z Sunday onward...Primarily VFR with surface high pressure
through Monday. A weak upper level disturbance may bring some
mountain snow showers 06-18Z Sunday with HIR TRRN OBSCD across
the nrn Greens for a time. Next large-scale precipitation system
tracks to our west Late Tuesday into Wednesday. Trending MVFR
with intervals of IFR in mainly rain, possibly as early as late
Tuesday...but more likely Tuesday night or Wednesday.
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